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Merge b5f7ab6b1c ("Merge tag 'fs-dedupe-last-block-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux") into android-mainline

Browse Source 
Baby steps in the 5.6-rc1 merge cycle to make things easier to review
and debug.

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: I005e68433be6b1d66bd56d7e1c8f44ab8e78bebe
This commit is contained in:
Greg Kroah-Hartman
2020-01-30 07:03:50 +01:00
parent f1bdff93de b5f7ab6b1c
commit 28b159de8e
1707 changed files with 51929 additions and 17257 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
.mailmap
View File

@@ -74,6 +74,7 @@ Dmitry Safonov <0x7f454c46@gmail.com> <dima@arista.com>
Domen Puncer <domen@coderock.org> Domen Puncer <domen@coderock.org>
Douglas Gilbert <dougg@torque.net> Douglas Gilbert <dougg@torque.net>
Ed L. Cashin <ecashin@coraid.com> Ed L. Cashin <ecashin@coraid.com>
Erik Kaneda <erik.kaneda@intel.com> <erik.schmauss@intel.com>
Evgeniy Polyakov <johnpol@2ka.mipt.ru> Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Felipe W Damasio <felipewd@terra.com.br> Felipe W Damasio <felipewd@terra.com.br>
Felix Kuhling <fxkuehl@gmx.de> Felix Kuhling <fxkuehl@gmx.de>
@@ -209,6 +210,10 @@ Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Patrick Mochel <mochel@digitalimplant.org> Patrick Mochel <mochel@digitalimplant.org>
Paul Burton <paulburton@kernel.org> <paul.burton@imgtec.com> Paul Burton <paulburton@kernel.org> <paul.burton@imgtec.com>
Paul Burton <paulburton@kernel.org> <paul.burton@mips.com> Paul Burton <paulburton@kernel.org> <paul.burton@mips.com>
Paul E. McKenney <paulmck@kernel.org> <paulmck@linux.ibm.com>
Paul E. McKenney <paulmck@kernel.org> <paulmck@linux.vnet.ibm.com>
Paul E. McKenney <paulmck@kernel.org> <paul.mckenney@linaro.org>
Paul E. McKenney <paulmck@kernel.org> <paulmck@us.ibm.com>
Peter A Jonsson <pj@ludd.ltu.se> Peter A Jonsson <pj@ludd.ltu.se>
Peter Oruba <peter@oruba.de> Peter Oruba <peter@oruba.de>
Peter Oruba <peter.oruba@amd.com> Peter Oruba <peter.oruba@amd.com>
@@ -217,6 +222,7 @@ Praveen BP <praveenbp@ti.com>
Punit Agrawal <punitagrawal@gmail.com> <punit.agrawal@arm.com> Punit Agrawal <punitagrawal@gmail.com> <punit.agrawal@arm.com>
Qais Yousef <qsyousef@gmail.com> <qais.yousef@imgtec.com> Qais Yousef <qsyousef@gmail.com> <qais.yousef@imgtec.com>
Quentin Perret <qperret@qperret.net> <quentin.perret@arm.com> Quentin Perret <qperret@qperret.net> <quentin.perret@arm.com>
Rafael J. Wysocki <rjw@rjwysocki.net> <rjw@sisk.pl>
Rajesh Shah <rajesh.shah@intel.com> Rajesh Shah <rajesh.shah@intel.com>
Ralf Baechle <ralf@linux-mips.org> Ralf Baechle <ralf@linux-mips.org>
Ralf Wildenhues <Ralf.Wildenhues@gmx.de> Ralf Wildenhues <Ralf.Wildenhues@gmx.de>

26
Documentation/ABI/obsolete/sysfs-selinux-disable Normal file
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@@ -0,0 +1,26 @@
What: /sys/fs/selinux/disable
Date: April 2005 (predates git)
KernelVersion: 2.6.12-rc2 (predates git)
Contact: selinux@vger.kernel.org
Description:
The selinuxfs "disable" node allows SELinux to be disabled at runtime
prior to a policy being loaded into the kernel. If disabled via this
mechanism, SELinux will remain disabled until the system is rebooted.
The preferred method of disabling SELinux is via the "selinux=0" boot
parameter, but the selinuxfs "disable" node was created to make it
easier for systems with primitive bootloaders that did not allow for
easy modification of the kernel command line. Unfortunately, allowing
for SELinux to be disabled at runtime makes it difficult to secure the
kernel's LSM hooks using the "__ro_after_init" feature.
Thankfully, the need for the SELinux runtime disable appears to be
gone, the default Kconfig configuration disables this selinuxfs node,
and only one of the major distributions, Fedora, supports disabling
SELinux at runtime. Fedora is in the process of removing the
selinuxfs "disable" node and once that is complete we will start the
slow process of removing this code from the kernel.
More information on /sys/fs/selinux/disable can be found under the
CONFIG_SECURITY_SELINUX_DISABLE Kconfig option.

33
Documentation/ABI/stable/sysfs-class-tpm
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@@ -1,7 +1,7 @@
What: /sys/class/tpm/tpmX/device/ What: /sys/class/tpm/tpmX/device/
Date: April 2005 Date: April 2005
KernelVersion: 2.6.12 KernelVersion: 2.6.12
Contact: tpmdd-devel@lists.sf.net Contact: linux-integrity@vger.kernel.org
Description: The device/ directory under a specific TPM instance exposes Description: The device/ directory under a specific TPM instance exposes
the properties of that TPM chip the properties of that TPM chip
@@ -9,7 +9,7 @@ Description: The device/ directory under a specific TPM instance exposes
What: /sys/class/tpm/tpmX/device/active What: /sys/class/tpm/tpmX/device/active
Date: April 2006 Date: April 2006
KernelVersion: 2.6.17 KernelVersion: 2.6.17
Contact: tpmdd-devel@lists.sf.net Contact: linux-integrity@vger.kernel.org
Description: The "active" property prints a '1' if the TPM chip is accepting Description: The "active" property prints a '1' if the TPM chip is accepting
commands. An inactive TPM chip still contains all the state of commands. An inactive TPM chip still contains all the state of
an active chip (Storage Root Key, NVRAM, etc), and can be an active chip (Storage Root Key, NVRAM, etc), and can be
@@ -21,7 +21,7 @@ Description: The "active" property prints a '1' if the TPM chip is accepting
What: /sys/class/tpm/tpmX/device/cancel What: /sys/class/tpm/tpmX/device/cancel
Date: June 2005 Date: June 2005
KernelVersion: 2.6.13 KernelVersion: 2.6.13
Contact: tpmdd-devel@lists.sf.net Contact: linux-integrity@vger.kernel.org
Description: The "cancel" property allows you to cancel the currently Description: The "cancel" property allows you to cancel the currently
pending TPM command. Writing any value to cancel will call the pending TPM command. Writing any value to cancel will call the
TPM vendor specific cancel operation. TPM vendor specific cancel operation.
@@ -29,7 +29,7 @@ Description: The "cancel" property allows you to cancel the currently
What: /sys/class/tpm/tpmX/device/caps What: /sys/class/tpm/tpmX/device/caps
Date: April 2005 Date: April 2005
KernelVersion: 2.6.12 KernelVersion: 2.6.12
Contact: tpmdd-devel@lists.sf.net Contact: linux-integrity@vger.kernel.org
Description: The "caps" property contains TPM manufacturer and version info. Description: The "caps" property contains TPM manufacturer and version info.
Example output: Example output:
@@ -46,7 +46,7 @@ Description: The "caps" property contains TPM manufacturer and version info.
What: /sys/class/tpm/tpmX/device/durations What: /sys/class/tpm/tpmX/device/durations
Date: March 2011 Date: March 2011
KernelVersion: 3.1 KernelVersion: 3.1
Contact: tpmdd-devel@lists.sf.net Contact: linux-integrity@vger.kernel.org
Description: The "durations" property shows the 3 vendor-specific values Description: The "durations" property shows the 3 vendor-specific values
used to wait for a short, medium and long TPM command. All used to wait for a short, medium and long TPM command. All
TPM commands are categorized as short, medium or long in TPM commands are categorized as short, medium or long in
@@ -69,7 +69,7 @@ Description: The "durations" property shows the 3 vendor-specific values
What: /sys/class/tpm/tpmX/device/enabled What: /sys/class/tpm/tpmX/device/enabled
Date: April 2006 Date: April 2006
KernelVersion: 2.6.17 KernelVersion: 2.6.17
Contact: tpmdd-devel@lists.sf.net Contact: linux-integrity@vger.kernel.org
Description: The "enabled" property prints a '1' if the TPM chip is enabled, Description: The "enabled" property prints a '1' if the TPM chip is enabled,
meaning that it should be visible to the OS. This property meaning that it should be visible to the OS. This property
may be visible but produce a '0' after some operation that may be visible but produce a '0' after some operation that
@@ -78,7 +78,7 @@ Description: The "enabled" property prints a '1' if the TPM chip is enabled,
What: /sys/class/tpm/tpmX/device/owned What: /sys/class/tpm/tpmX/device/owned
Date: April 2006 Date: April 2006
KernelVersion: 2.6.17 KernelVersion: 2.6.17
Contact: tpmdd-devel@lists.sf.net Contact: linux-integrity@vger.kernel.org
Description: The "owned" property produces a '1' if the TPM_TakeOwnership Description: The "owned" property produces a '1' if the TPM_TakeOwnership
ordinal has been executed successfully in the chip. A '0' ordinal has been executed successfully in the chip. A '0'
indicates that ownership hasn't been taken. indicates that ownership hasn't been taken.
@@ -86,7 +86,7 @@ Description: The "owned" property produces a '1' if the TPM_TakeOwnership
What: /sys/class/tpm/tpmX/device/pcrs What: /sys/class/tpm/tpmX/device/pcrs
Date: April 2005 Date: April 2005
KernelVersion: 2.6.12 KernelVersion: 2.6.12
Contact: tpmdd-devel@lists.sf.net Contact: linux-integrity@vger.kernel.org
Description: The "pcrs" property will dump the current value of all Platform Description: The "pcrs" property will dump the current value of all Platform
Configuration Registers in the TPM. Note that since these Configuration Registers in the TPM. Note that since these
values may be constantly changing, the output is only valid values may be constantly changing, the output is only valid
@@ -109,7 +109,7 @@ Description: The "pcrs" property will dump the current value of all Platform
What: /sys/class/tpm/tpmX/device/pubek What: /sys/class/tpm/tpmX/device/pubek
Date: April 2005 Date: April 2005
KernelVersion: 2.6.12 KernelVersion: 2.6.12
Contact: tpmdd-devel@lists.sf.net Contact: linux-integrity@vger.kernel.org
Description: The "pubek" property will return the TPM's public endorsement Description: The "pubek" property will return the TPM's public endorsement
key if possible. If the TPM has had ownership established and key if possible. If the TPM has had ownership established and
is version 1.2, the pubek will not be available without the is version 1.2, the pubek will not be available without the
@@ -161,7 +161,7 @@ Description: The "pubek" property will return the TPM's public endorsement
What: /sys/class/tpm/tpmX/device/temp_deactivated What: /sys/class/tpm/tpmX/device/temp_deactivated
Date: April 2006 Date: April 2006
KernelVersion: 2.6.17 KernelVersion: 2.6.17
Contact: tpmdd-devel@lists.sf.net Contact: linux-integrity@vger.kernel.org
Description: The "temp_deactivated" property returns a '1' if the chip has Description: The "temp_deactivated" property returns a '1' if the chip has
been temporarily deactivated, usually until the next power been temporarily deactivated, usually until the next power
cycle. Whether a warm boot (reboot) will clear a TPM chip cycle. Whether a warm boot (reboot) will clear a TPM chip
@@ -170,7 +170,7 @@ Description: The "temp_deactivated" property returns a '1' if the chip has
What: /sys/class/tpm/tpmX/device/timeouts What: /sys/class/tpm/tpmX/device/timeouts
Date: March 2011 Date: March 2011
KernelVersion: 3.1 KernelVersion: 3.1
Contact: tpmdd-devel@lists.sf.net Contact: linux-integrity@vger.kernel.org
Description: The "timeouts" property shows the 4 vendor-specific values Description: The "timeouts" property shows the 4 vendor-specific values
for the TPM's interface spec timeouts. The use of these for the TPM's interface spec timeouts. The use of these
timeouts is defined by the TPM interface spec that the chip timeouts is defined by the TPM interface spec that the chip
@@ -183,3 +183,14 @@ Description: The "timeouts" property shows the 4 vendor-specific values
The four timeout values are shown in usecs, with a trailing The four timeout values are shown in usecs, with a trailing
"[original]" or "[adjusted]" depending on whether the values "[original]" or "[adjusted]" depending on whether the values
were scaled by the driver to be reported in usec from msecs. were scaled by the driver to be reported in usec from msecs.
What: /sys/class/tpm/tpmX/tpm_version_major
Date: October 2019
KernelVersion: 5.5
Contact: linux-integrity@vger.kernel.org
Description: The "tpm_version_major" property shows the TCG spec major version
implemented by the TPM device.
Example output:
2

171
Documentation/ABI/stable/sysfs-driver-dma-idxd Normal file
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@@ -0,0 +1,171 @@
What: sys/bus/dsa/devices/dsa<m>/cdev_major
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The major number that the character device driver assigned to
this device.
What: sys/bus/dsa/devices/dsa<m>/errors
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The error information for this device.
What: sys/bus/dsa/devices/dsa<m>/max_batch_size
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The largest number of work descriptors in a batch.
What: sys/bus/dsa/devices/dsa<m>/max_work_queues_size
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The maximum work queue size supported by this device.
What: sys/bus/dsa/devices/dsa<m>/max_engines
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The maximum number of engines supported by this device.
What: sys/bus/dsa/devices/dsa<m>/max_groups
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The maximum number of groups can be created under this device.
What: sys/bus/dsa/devices/dsa<m>/max_tokens
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The total number of bandwidth tokens supported by this device.
The bandwidth tokens represent resources within the DSA
implementation, and these resources are allocated by engines to
support operations.
What: sys/bus/dsa/devices/dsa<m>/max_transfer_size
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The number of bytes to be read from the source address to
perform the operation. The maximum transfer size is dependent on
the workqueue the descriptor was submitted to.
What: sys/bus/dsa/devices/dsa<m>/max_work_queues
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The maximum work queue number that this device supports.
What: sys/bus/dsa/devices/dsa<m>/numa_node
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The numa node number for this device.
What: sys/bus/dsa/devices/dsa<m>/op_cap
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The operation capability bit mask specify the operation types
supported by the this device.
What: sys/bus/dsa/devices/dsa<m>/state
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The state information of this device. It can be either enabled
or disabled.
What: sys/bus/dsa/devices/dsa<m>/group<m>.<n>
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The assigned group under this device.
What: sys/bus/dsa/devices/dsa<m>/engine<m>.<n>
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The assigned engine under this device.
What: sys/bus/dsa/devices/dsa<m>/wq<m>.<n>
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The assigned work queue under this device.
What: sys/bus/dsa/devices/dsa<m>/configurable
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: To indicate if this device is configurable or not.
What: sys/bus/dsa/devices/dsa<m>/token_limit
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The maximum number of bandwidth tokens that may be in use at
one time by operations that access low bandwidth memory in the
device.
What: sys/bus/dsa/devices/wq<m>.<n>/group_id
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The group id that this work queue belongs to.
What: sys/bus/dsa/devices/wq<m>.<n>/size
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The work queue size for this work queue.
What: sys/bus/dsa/devices/wq<m>.<n>/type
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The type of this work queue, it can be "kernel" type for work
queue usages in the kernel space or "user" type for work queue
usages by applications in user space.
What: sys/bus/dsa/devices/wq<m>.<n>/cdev_minor
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The minor number assigned to this work queue by the character
device driver.
What: sys/bus/dsa/devices/wq<m>.<n>/mode
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The work queue mode type for this work queue.
What: sys/bus/dsa/devices/wq<m>.<n>/priority
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The priority value of this work queue, it is a vlue relative to
other work queue in the same group to control quality of service
for dispatching work from multiple workqueues in the same group.
What: sys/bus/dsa/devices/wq<m>.<n>/state
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The current state of the work queue.
What: sys/bus/dsa/devices/wq<m>.<n>/threshold
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The number of entries in this work queue that may be filled
via a limited portal.
What: sys/bus/dsa/devices/engine<m>.<n>/group_id
Date: Oct 25, 2019
KernelVersion: 5.6.0
Contact: dmaengine@vger.kernel.org
Description: The group that this engine belongs to.

79
Documentation/ABI/stable/sysfs-driver-mlxreg-io
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@@ -1,5 +1,4 @@
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/asic_health What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/asic_health
Date: June 2018 Date: June 2018
KernelVersion: 4.19 KernelVersion: 4.19
Contact: Vadim Pasternak <vadimpmellanox.com> Contact: Vadim Pasternak <vadimpmellanox.com>
@@ -19,7 +18,6 @@ Description: These files show with which CPLD versions have been burned
The files are read only. The files are read only.
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/fan_dir What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/fan_dir
Date: December 2018 Date: December 2018
KernelVersion: 5.0 KernelVersion: 5.0
Contact: Vadim Pasternak <vadimpmellanox.com> Contact: Vadim Pasternak <vadimpmellanox.com>
@@ -30,7 +28,6 @@ Description: This file shows the system fans direction:
The files are read only. The files are read only.
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/cpld3_version What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/cpld3_version
Date: November 2018 Date: November 2018
KernelVersion: 5.0 KernelVersion: 5.0
Contact: Vadim Pasternak <vadimpmellanox.com> Contact: Vadim Pasternak <vadimpmellanox.com>
@@ -40,7 +37,6 @@ Description: These files show with which CPLD versions have been burned
The files are read only. The files are read only.
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/jtag_enable What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/jtag_enable
Date: November 2018 Date: November 2018
KernelVersion: 5.0 KernelVersion: 5.0
Contact: Vadim Pasternak <vadimpmellanox.com> Contact: Vadim Pasternak <vadimpmellanox.com>
@@ -108,7 +104,6 @@ What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_comex_pwr_fail
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_from_comex What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_from_comex
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_system What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_system
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_voltmon_upgrade_fail What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_voltmon_upgrade_fail
Date: November 2018 Date: November 2018
KernelVersion: 5.0 KernelVersion: 5.0
Contact: Vadim Pasternak <vadimpmellanox.com> Contact: Vadim Pasternak <vadimpmellanox.com>
@@ -130,6 +125,12 @@ Description: These files show with which CPLD versions have been burned
The files are read only. The files are read only.
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_comex_thermal
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_comex_wd
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_from_asic
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_reload_bios
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_sff_wd
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_swb_wd
Date: June 2019 Date: June 2019
KernelVersion: 5.3 KernelVersion: 5.3
Contact: Vadim Pasternak <vadimpmellanox.com> Contact: Vadim Pasternak <vadimpmellanox.com>
@@ -143,9 +144,65 @@ Description: These files show the system reset cause, as following:
The files are read only. The files are read only.
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_comex_thermal What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/config1
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_comex_wd What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/config2
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_from_asic Date: January 2020
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_reload_bios KernelVersion: 5.6
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_sff_wd Contact: Vadim Pasternak <vadimpmellanox.com>
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_swb_wd Description: These files show system static topology identification
like system's static I2C topology, number and type of FPGA
devices within the system and so on.
The files are read only.
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_ac_pwr_fail
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_platform
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_soc
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/reset_sw_pwr_off
Date: January 2020
KernelVersion: 5.6
Contact: Vadim Pasternak <vadimpmellanox.com>
Description: These files show the system reset causes, as following: reset
due to AC power failure, reset invoked from software by
assertion reset signal through CPLD. reset caused by signal
asserted by SOC through ACPI register, reset invoked from
software by assertion power off signal through CPLD.
The files are read only.
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/pcie_asic_reset_dis
Date: January 2020
KernelVersion: 5.6
Contact: Vadim Pasternak <vadimpmellanox.com>
Description: This file allows to retain ASIC up during PCIe root complex
reset, when attribute is set 1.
The file is read/write.
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/vpd_wp
Date: January 2020
KernelVersion: 5.6
Contact: Vadim Pasternak <vadimpmellanox.com>
Description: This file allows to overwrite system VPD hardware wrtie
protection when attribute is set 1.
The file is read/write.
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/voltreg_update_status
Date: January 2020
KernelVersion: 5.6
Contact: Vadim Pasternak <vadimpmellanox.com>
Description: This file exposes the configuration update status of burnable
voltage regulator devices. The status values are as following:
0 - OK; 1 - CRC failure; 2 = I2C failure; 3 - in progress.
The file is read only.
What: /sys/devices/platform/mlxplat/mlxreg-io/hwmon/hwmon*/ufm_version
Date: January 2020
KernelVersion: 5.6
Contact: Vadim Pasternak <vadimpmellanox.com>
Description: This file exposes the firmware version of burnable voltage
regulator devices.
The file is read only.

18
Documentation/ABI/testing/sysfs-class-devfreq
View File

@@ -7,6 +7,13 @@ Description:
The name of devfreq object denoted as ... is same as the The name of devfreq object denoted as ... is same as the
name of device using devfreq. name of device using devfreq.
What: /sys/class/devfreq/.../name
Date: November 2019
Contact: Chanwoo Choi <cw00.choi@samsung.com>
Description:
The /sys/class/devfreq/.../name shows the name of device
of the corresponding devfreq object.
What: /sys/class/devfreq/.../governor What: /sys/class/devfreq/.../governor
Date: September 2011 Date: September 2011
Contact: MyungJoo Ham <myungjoo.ham@samsung.com> Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
@@ -48,12 +55,15 @@ What: /sys/class/devfreq/.../trans_stat
Date: October 2012 Date: October 2012
Contact: MyungJoo Ham <myungjoo.ham@samsung.com> Contact: MyungJoo Ham <myungjoo.ham@samsung.com>
Description: Description:
This ABI shows the statistics of devfreq behavior on a This ABI shows or clears the statistics of devfreq behavior
specific device. It shows the time spent in each state and on a specific device. It shows the time spent in each state
the number of transitions between states. and the number of transitions between states.
In order to activate this ABI, the devfreq target device In order to activate this ABI, the devfreq target device
driver should provide the list of available frequencies driver should provide the list of available frequencies
with its profile. with its profile. If need to reset the statistics of devfreq
behavior on a specific device, enter 0(zero) to 'trans_stat'
as following:
echo 0 > /sys/class/devfreq/.../trans_stat
What: /sys/class/devfreq/.../userspace/set_freq What: /sys/class/devfreq/.../userspace/set_freq
Date: September 2011 Date: September 2011

6
Documentation/ABI/testing/sysfs-devices-system-cpu
View File

@@ -196,6 +196,12 @@ Description:
does not reflect it. Likewise, if one enables a deep state but a does not reflect it. Likewise, if one enables a deep state but a
lighter state still is disabled, then this has no effect. lighter state still is disabled, then this has no effect.
What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/default_status
Date: December 2019
KernelVersion: v5.6
Contact: Linux power management list <linux-pm@vger.kernel.org>
Description:
(RO) The default status of this state, "enabled" or "disabled".
What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/residency What: /sys/devices/system/cpu/cpuX/cpuidle/stateN/residency
Date: March 2014 Date: March 2014

10
Documentation/ABI/testing/sysfs-platform-asus-wmi
View File

@@ -46,3 +46,13 @@ Description:
* 0 - normal, * 0 - normal,
* 1 - overboost, * 1 - overboost,
* 2 - silent * 2 - silent
What: /sys/devices/platform/<platform>/throttle_thermal_policy
Date: Dec 2019
KernelVersion: 5.6
Contact: "Leonid Maksymchuk" <leonmaxx@gmail.com>
Description:
Throttle thermal policy mode:
* 0 - default,
* 1 - overboost,
* 2 - silent

13
Documentation/ABI/testing/sysfs-power
View File

@@ -407,3 +407,16 @@ Contact: Kalesh Singh <kaleshsingh96@gmail.com>
Description: Description:
The /sys/power/suspend_stats/last_failed_step file contains The /sys/power/suspend_stats/last_failed_step file contains
the last failed step in the suspend/resume path. the last failed step in the suspend/resume path.
What: /sys/power/sync_on_suspend
Date: October 2019
Contact: Jonas Meurer <jonas@freesources.org>
Description:
This file controls whether or not the kernel will sync()
filesystems during system suspend (after freezing user space
and before suspending devices).
Writing a "1" to this file enables the sync() and writing a "0"
disables it. Reads from the file return the current value.
The default is "1" if the build-time "SUSPEND_SKIP_SYNC" config
flag is unset, or "0" otherwise.

53
Documentation/RCU/NMI-RCU.txt → Documentation/RCU/NMI-RCU.rst
View File

@@ -1,4 +1,7 @@
.. _NMI_rcu_doc:
Using RCU to Protect Dynamic NMI Handlers Using RCU to Protect Dynamic NMI Handlers
=========================================
Although RCU is usually used to protect read-mostly data structures, Although RCU is usually used to protect read-mostly data structures,
@@ -9,7 +12,7 @@ work in "arch/x86/oprofile/nmi_timer_int.c" and in
"arch/x86/kernel/traps.c". "arch/x86/kernel/traps.c".
The relevant pieces of code are listed below, each followed by a The relevant pieces of code are listed below, each followed by a
brief explanation. brief explanation::
static int dummy_nmi_callback(struct pt_regs *regs, int cpu) static int dummy_nmi_callback(struct pt_regs *regs, int cpu)
{ {
@@ -18,12 +21,12 @@ brief explanation.
The dummy_nmi_callback() function is a "dummy" NMI handler that does The dummy_nmi_callback() function is a "dummy" NMI handler that does
nothing, but returns zero, thus saying that it did nothing, allowing nothing, but returns zero, thus saying that it did nothing, allowing
the NMI handler to take the default machine-specific action. the NMI handler to take the default machine-specific action::
static nmi_callback_t nmi_callback = dummy_nmi_callback; static nmi_callback_t nmi_callback = dummy_nmi_callback;
This nmi_callback variable is a global function pointer to the current This nmi_callback variable is a global function pointer to the current
NMI handler. NMI handler::
void do_nmi(struct pt_regs * regs, long error_code) void do_nmi(struct pt_regs * regs, long error_code)
{ {
@@ -53,11 +56,12 @@ anyway. However, in practice it is a good documentation aid, particularly
for anyone attempting to do something similar on Alpha or on systems for anyone attempting to do something similar on Alpha or on systems
with aggressive optimizing compilers. with aggressive optimizing compilers.
Quick Quiz: Why might the rcu_dereference_sched() be necessary on Alpha, Quick Quiz:
given that the code referenced by the pointer is read-only? Why might the rcu_dereference_sched() be necessary on Alpha, given that the code referenced by the pointer is read-only?
:ref:`Answer to Quick Quiz <answer_quick_quiz_NMI>`
Back to the discussion of NMI and RCU... Back to the discussion of NMI and RCU::
void set_nmi_callback(nmi_callback_t callback) void set_nmi_callback(nmi_callback_t callback)
{ {
@@ -68,7 +72,7 @@ The set_nmi_callback() function registers an NMI handler. Note that any
data that is to be used by the callback must be initialized up -before- data that is to be used by the callback must be initialized up -before-
the call to set_nmi_callback(). On architectures that do not order the call to set_nmi_callback(). On architectures that do not order
writes, the rcu_assign_pointer() ensures that the NMI handler sees the writes, the rcu_assign_pointer() ensures that the NMI handler sees the
initialized values. initialized values::
void unset_nmi_callback(void) void unset_nmi_callback(void)
{ {
@@ -82,7 +86,7 @@ up any data structures used by the old NMI handler until execution
of it completes on all other CPUs. of it completes on all other CPUs.
One way to accomplish this is via synchronize_rcu(), perhaps as One way to accomplish this is via synchronize_rcu(), perhaps as
follows: follows::
unset_nmi_callback(); unset_nmi_callback();
synchronize_rcu(); synchronize_rcu();
@@ -98,24 +102,23 @@ to free up the handler's data as soon as synchronize_rcu() returns.
Important note: for this to work, the architecture in question must Important note: for this to work, the architecture in question must
invoke nmi_enter() and nmi_exit() on NMI entry and exit, respectively. invoke nmi_enter() and nmi_exit() on NMI entry and exit, respectively.
.. _answer_quick_quiz_NMI:
Answer to Quick Quiz Answer to Quick Quiz:
Why might the rcu_dereference_sched() be necessary on Alpha, given that the code referenced by the pointer is read-only?
Why might the rcu_dereference_sched() be necessary on Alpha, given The caller to set_nmi_callback() might well have
that the code referenced by the pointer is read-only? initialized some data that is to be used by the new NMI
handler. In this case, the rcu_dereference_sched() would
be needed, because otherwise a CPU that received an NMI
just after the new handler was set might see the pointer
to the new NMI handler, but the old pre-initialized
version of the handler's data.
Answer: The caller to set_nmi_callback() might well have This same sad story can happen on other CPUs when using
initialized some data that is to be used by the new NMI a compiler with aggressive pointer-value speculation
handler. In this case, the rcu_dereference_sched() would optimizations.
be needed, because otherwise a CPU that received an NMI
just after the new handler was set might see the pointer
to the new NMI handler, but the old pre-initialized
version of the handler's data.
This same sad story can happen on other CPUs when using More important, the rcu_dereference_sched() makes it
a compiler with aggressive pointer-value speculation clear to someone reading the code that the pointer is
optimizations. being protected by RCU-sched.
More important, the rcu_dereference_sched() makes it
clear to someone reading the code that the pointer is
being protected by RCU-sched.

34
Documentation/RCU/arrayRCU.txt → Documentation/RCU/arrayRCU.rst
View File

@@ -1,19 +1,21 @@
Using RCU to Protect Read-Mostly Arrays .. _array_rcu_doc:
Using RCU to Protect Read-Mostly Arrays
=======================================
Although RCU is more commonly used to protect linked lists, it can Although RCU is more commonly used to protect linked lists, it can
also be used to protect arrays. Three situations are as follows: also be used to protect arrays. Three situations are as follows:
1. Hash Tables 1. :ref:`Hash Tables <hash_tables>`
2. Static Arrays 2. :ref:`Static Arrays <static_arrays>`
3. Resizeable Arrays 3. :ref:`Resizable Arrays <resizable_arrays>`
Each of these three situations involves an RCU-protected pointer to an Each of these three situations involves an RCU-protected pointer to an
array that is separately indexed. It might be tempting to consider use array that is separately indexed. It might be tempting to consider use
of RCU to instead protect the index into an array, however, this use of RCU to instead protect the index into an array, however, this use
case is -not- supported. The problem with RCU-protected indexes into case is **not** supported. The problem with RCU-protected indexes into
arrays is that compilers can play way too many optimization games with arrays is that compilers can play way too many optimization games with
integers, which means that the rules governing handling of these indexes integers, which means that the rules governing handling of these indexes
are far more trouble than they are worth. If RCU-protected indexes into are far more trouble than they are worth. If RCU-protected indexes into
@@ -24,16 +26,20 @@ to be safely used.
That aside, each of the three RCU-protected pointer situations are That aside, each of the three RCU-protected pointer situations are
described in the following sections. described in the following sections.
.. _hash_tables:
Situation 1: Hash Tables Situation 1: Hash Tables
------------------------
Hash tables are often implemented as an array, where each array entry Hash tables are often implemented as an array, where each array entry
has a linked-list hash chain. Each hash chain can be protected by RCU has a linked-list hash chain. Each hash chain can be protected by RCU
as described in the listRCU.txt document. This approach also applies as described in the listRCU.txt document. This approach also applies
to other array-of-list situations, such as radix trees. to other array-of-list situations, such as radix trees.
.. _static_arrays:
Situation 2: Static Arrays Situation 2: Static Arrays
--------------------------
Static arrays, where the data (rather than a pointer to the data) is Static arrays, where the data (rather than a pointer to the data) is
located in each array element, and where the array is never resized, located in each array element, and where the array is never resized,
@@ -41,13 +47,17 @@ have not been used with RCU. Rik van Riel recommends using seqlock in
this situation, which would also have minimal read-side overhead as long this situation, which would also have minimal read-side overhead as long
as updates are rare. as updates are rare.
Quick Quiz: Why is it so important that updates be rare when Quick Quiz:
using seqlock? Why is it so important that updates be rare when using seqlock?
:ref:`Answer to Quick Quiz <answer_quick_quiz_seqlock>`
Situation 3: Resizeable Arrays .. _resizable_arrays:
Use of RCU for resizeable arrays is demonstrated by the grow_ary() Situation 3: Resizable Arrays
------------------------------
Use of RCU for resizable arrays is demonstrated by the grow_ary()
function formerly used by the System V IPC code. The array is used function formerly used by the System V IPC code. The array is used
to map from semaphore, message-queue, and shared-memory IDs to the data to map from semaphore, message-queue, and shared-memory IDs to the data
structure that represents the corresponding IPC construct. The grow_ary() structure that represents the corresponding IPC construct. The grow_ary()
@@ -60,7 +70,7 @@ the remainder of the new, updates the ids->entries pointer to point to
the new array, and invokes ipc_rcu_putref() to free up the old array. the new array, and invokes ipc_rcu_putref() to free up the old array.
Note that rcu_assign_pointer() is used to update the ids->entries pointer, Note that rcu_assign_pointer() is used to update the ids->entries pointer,
which includes any memory barriers required on whatever architecture which includes any memory barriers required on whatever architecture
you are running on. you are running on::
static int grow_ary(struct ipc_ids* ids, int newsize) static int grow_ary(struct ipc_ids* ids, int newsize)
{ {
@@ -112,7 +122,7 @@ a simple check suffices. The pointer to the structure corresponding
to the desired IPC object is placed in "out", with NULL indicating to the desired IPC object is placed in "out", with NULL indicating
a non-existent entry. After acquiring "out->lock", the "out->deleted" a non-existent entry. After acquiring "out->lock", the "out->deleted"
flag indicates whether the IPC object is in the process of being flag indicates whether the IPC object is in the process of being
deleted, and, if not, the pointer is returned. deleted, and, if not, the pointer is returned::
struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id) struct kern_ipc_perm* ipc_lock(struct ipc_ids* ids, int id)
{ {
@@ -144,8 +154,10 @@ deleted, and, if not, the pointer is returned.
return out; return out;
} }
.. _answer_quick_quiz_seqlock:
Answer to Quick Quiz: Answer to Quick Quiz:
Why is it so important that updates be rare when using seqlock?
The reason that it is important that updates be rare when The reason that it is important that updates be rare when
using seqlock is that frequent updates can livelock readers. using seqlock is that frequent updates can livelock readers.

5
Documentation/RCU/index.rst
View File

@@ -7,8 +7,13 @@ RCU concepts
.. toctree:: .. toctree::
:maxdepth: 3 :maxdepth: 3
arrayRCU
rcubarrier
rcu_dereference
whatisRCU
rcu rcu
listRCU listRCU
NMI-RCU
UP UP
Design/Memory-Ordering/Tree-RCU-Memory-Ordering Design/Memory-Ordering/Tree-RCU-Memory-Ordering

2
Documentation/RCU/lockdep-splat.txt
View File

@@ -99,7 +99,7 @@ With this change, the rcu_dereference() is always within an RCU
read-side critical section, which again would have suppressed the read-side critical section, which again would have suppressed the
above lockdep-RCU splat. above lockdep-RCU splat.
But in this particular case, we don't actually deference the pointer But in this particular case, we don't actually dereference the pointer
returned from rcu_dereference(). Instead, that pointer is just compared returned from rcu_dereference(). Instead, that pointer is just compared
to the cic pointer, which means that the rcu_dereference() can be replaced to the cic pointer, which means that the rcu_dereference() can be replaced
by rcu_access_pointer() as follows: by rcu_access_pointer() as follows:

75
Documentation/RCU/rcu_dereference.txt → Documentation/RCU/rcu_dereference.rst
View File

@@ -1,4 +1,7 @@
.. _rcu_dereference_doc:
PROPER CARE AND FEEDING OF RETURN VALUES FROM rcu_dereference() PROPER CARE AND FEEDING OF RETURN VALUES FROM rcu_dereference()
===============================================================
Most of the time, you can use values from rcu_dereference() or one of Most of the time, you can use values from rcu_dereference() or one of
the similar primitives without worries. Dereferencing (prefix "*"), the similar primitives without worries. Dereferencing (prefix "*"),
@@ -8,7 +11,7 @@ subtraction of constants, and casts all work quite naturally and safely.
It is nevertheless possible to get into trouble with other operations. It is nevertheless possible to get into trouble with other operations.
Follow these rules to keep your RCU code working properly: Follow these rules to keep your RCU code working properly:
o You must use one of the rcu_dereference() family of primitives - You must use one of the rcu_dereference() family of primitives
to load an RCU-protected pointer, otherwise CONFIG_PROVE_RCU to load an RCU-protected pointer, otherwise CONFIG_PROVE_RCU
will complain. Worse yet, your code can see random memory-corruption will complain. Worse yet, your code can see random memory-corruption
bugs due to games that compilers and DEC Alpha can play. bugs due to games that compilers and DEC Alpha can play.
@@ -25,24 +28,24 @@ o You must use one of the rcu_dereference() family of primitives
for an example where the compiler can in fact deduce the exact for an example where the compiler can in fact deduce the exact
value of the pointer, and thus cause misordering. value of the pointer, and thus cause misordering.
o You are only permitted to use rcu_dereference on pointer values. - You are only permitted to use rcu_dereference on pointer values.
The compiler simply knows too much about integral values to The compiler simply knows too much about integral values to
trust it to carry dependencies through integer operations. trust it to carry dependencies through integer operations.
There are a very few exceptions, namely that you can temporarily There are a very few exceptions, namely that you can temporarily
cast the pointer to uintptr_t in order to: cast the pointer to uintptr_t in order to:
o Set bits and clear bits down in the must-be-zero low-order - Set bits and clear bits down in the must-be-zero low-order
bits of that pointer. This clearly means that the pointer bits of that pointer. This clearly means that the pointer
must have alignment constraints, for example, this does must have alignment constraints, for example, this does
-not- work in general for char* pointers. -not- work in general for char* pointers.
o XOR bits to translate pointers, as is done in some - XOR bits to translate pointers, as is done in some
classic buddy-allocator algorithms. classic buddy-allocator algorithms.
It is important to cast the value back to pointer before It is important to cast the value back to pointer before
doing much of anything else with it. doing much of anything else with it.
o Avoid cancellation when using the "+" and "-" infix arithmetic - Avoid cancellation when using the "+" and "-" infix arithmetic
operators. For example, for a given variable "x", avoid operators. For example, for a given variable "x", avoid
"(x-(uintptr_t)x)" for char* pointers. The compiler is within its "(x-(uintptr_t)x)" for char* pointers. The compiler is within its
rights to substitute zero for this sort of expression, so that rights to substitute zero for this sort of expression, so that
@@ -54,16 +57,16 @@ o Avoid cancellation when using the "+" and "-" infix arithmetic
"p+a-b" is safe because its value still necessarily depends on "p+a-b" is safe because its value still necessarily depends on
the rcu_dereference(), thus maintaining proper ordering. the rcu_dereference(), thus maintaining proper ordering.
o If you are using RCU to protect JITed functions, so that the - If you are using RCU to protect JITed functions, so that the
"()" function-invocation operator is applied to a value obtained "()" function-invocation operator is applied to a value obtained
(directly or indirectly) from rcu_dereference(), you may need to (directly or indirectly) from rcu_dereference(), you may need to
interact directly with the hardware to flush instruction caches. interact directly with the hardware to flush instruction caches.
This issue arises on some systems when a newly JITed function is This issue arises on some systems when a newly JITed function is
using the same memory that was used by an earlier JITed function. using the same memory that was used by an earlier JITed function.
o Do not use the results from relational operators ("==", "!=", - Do not use the results from relational operators ("==", "!=",
">", ">=", "<", or "<=") when dereferencing. For example, ">", ">=", "<", or "<=") when dereferencing. For example,
the following (quite strange) code is buggy: the following (quite strange) code is buggy::
int *p; int *p;
int *q; int *q;
@@ -81,11 +84,11 @@ o Do not use the results from relational operators ("==", "!=",
after such branches, but can speculate loads, which can again after such branches, but can speculate loads, which can again
result in misordering bugs. result in misordering bugs.
o Be very careful about comparing pointers obtained from - Be very careful about comparing pointers obtained from
rcu_dereference() against non-NULL values. As Linus Torvalds rcu_dereference() against non-NULL values. As Linus Torvalds
explained, if the two pointers are equal, the compiler could explained, if the two pointers are equal, the compiler could
substitute the pointer you are comparing against for the pointer substitute the pointer you are comparing against for the pointer
obtained from rcu_dereference(). For example: obtained from rcu_dereference(). For example::
p = rcu_dereference(gp); p = rcu_dereference(gp);
if (p == &default_struct) if (p == &default_struct)
@@ -93,7 +96,7 @@ o Be very careful about comparing pointers obtained from
Because the compiler now knows that the value of "p" is exactly Because the compiler now knows that the value of "p" is exactly
the address of the variable "default_struct", it is free to the address of the variable "default_struct", it is free to
transform this code into the following: transform this code into the following::
p = rcu_dereference(gp); p = rcu_dereference(gp);
if (p == &default_struct) if (p == &default_struct)
@@ -105,14 +108,14 @@ o Be very careful about comparing pointers obtained from
However, comparisons are OK in the following cases: However, comparisons are OK in the following cases:
o The comparison was against the NULL pointer. If the - The comparison was against the NULL pointer. If the
compiler knows that the pointer is NULL, you had better compiler knows that the pointer is NULL, you had better
not be dereferencing it anyway. If the comparison is not be dereferencing it anyway. If the comparison is
non-equal, the compiler is none the wiser. Therefore, non-equal, the compiler is none the wiser. Therefore,
it is safe to compare pointers from rcu_dereference() it is safe to compare pointers from rcu_dereference()
against NULL pointers. against NULL pointers.
o The pointer is never dereferenced after being compared. - The pointer is never dereferenced after being compared.
Since there are no subsequent dereferences, the compiler Since there are no subsequent dereferences, the compiler
cannot use anything it learned from the comparison cannot use anything it learned from the comparison
to reorder the non-existent subsequent dereferences. to reorder the non-existent subsequent dereferences.
@@ -124,31 +127,31 @@ o Be very careful about comparing pointers obtained from
dereferenced, rcu_access_pointer() should be used in place dereferenced, rcu_access_pointer() should be used in place
of rcu_dereference(). of rcu_dereference().
o The comparison is against a pointer that references memory - The comparison is against a pointer that references memory
that was initialized "a long time ago." The reason that was initialized "a long time ago." The reason
this is safe is that even if misordering occurs, the this is safe is that even if misordering occurs, the
misordering will not affect the accesses that follow misordering will not affect the accesses that follow
the comparison. So exactly how long ago is "a long the comparison. So exactly how long ago is "a long
time ago"? Here are some possibilities: time ago"? Here are some possibilities:
o Compile time. - Compile time.
o Boot time. - Boot time.
o Module-init time for module code. - Module-init time for module code.
o Prior to kthread creation for kthread code. - Prior to kthread creation for kthread code.
o During some prior acquisition of the lock that - During some prior acquisition of the lock that
we now hold. we now hold.
o Before mod_timer() time for a timer handler. - Before mod_timer() time for a timer handler.
There are many other possibilities involving the Linux There are many other possibilities involving the Linux
kernel's wide array of primitives that cause code to kernel's wide array of primitives that cause code to
be invoked at a later time. be invoked at a later time.
o The pointer being compared against also came from - The pointer being compared against also came from
rcu_dereference(). In this case, both pointers depend rcu_dereference(). In this case, both pointers depend
on one rcu_dereference() or another, so you get proper on one rcu_dereference() or another, so you get proper
ordering either way. ordering either way.
@@ -159,13 +162,13 @@ o Be very careful about comparing pointers obtained from
of such an RCU usage bug is shown in the section titled of such an RCU usage bug is shown in the section titled
"EXAMPLE OF AMPLIFIED RCU-USAGE BUG". "EXAMPLE OF AMPLIFIED RCU-USAGE BUG".
o All of the accesses following the comparison are stores, - All of the accesses following the comparison are stores,
so that a control dependency preserves the needed ordering. so that a control dependency preserves the needed ordering.
That said, it is easy to get control dependencies wrong. That said, it is easy to get control dependencies wrong.
Please see the "CONTROL DEPENDENCIES" section of Please see the "CONTROL DEPENDENCIES" section of
Documentation/memory-barriers.txt for more details. Documentation/memory-barriers.txt for more details.
o The pointers are not equal -and- the compiler does - The pointers are not equal -and- the compiler does
not have enough information to deduce the value of the not have enough information to deduce the value of the
pointer. Note that the volatile cast in rcu_dereference() pointer. Note that the volatile cast in rcu_dereference()
will normally prevent the compiler from knowing too much. will normally prevent the compiler from knowing too much.
@@ -175,7 +178,7 @@ o Be very careful about comparing pointers obtained from
comparison will provide exactly the information that the comparison will provide exactly the information that the
compiler needs to deduce the value of the pointer. compiler needs to deduce the value of the pointer.
o Disable any value-speculation optimizations that your compiler - Disable any value-speculation optimizations that your compiler
might provide, especially if you are making use of feedback-based might provide, especially if you are making use of feedback-based
optimizations that take data collected from prior runs. Such optimizations that take data collected from prior runs. Such
value-speculation optimizations reorder operations by design. value-speculation optimizations reorder operations by design.
@@ -188,11 +191,12 @@ o Disable any value-speculation optimizations that your compiler
EXAMPLE OF AMPLIFIED RCU-USAGE BUG EXAMPLE OF AMPLIFIED RCU-USAGE BUG
----------------------------------
Because updaters can run concurrently with RCU readers, RCU readers can Because updaters can run concurrently with RCU readers, RCU readers can
see stale and/or inconsistent values. If RCU readers need fresh or see stale and/or inconsistent values. If RCU readers need fresh or
consistent values, which they sometimes do, they need to take proper consistent values, which they sometimes do, they need to take proper
precautions. To see this, consider the following code fragment: precautions. To see this, consider the following code fragment::
struct foo { struct foo {
int a; int a;
@@ -244,7 +248,7 @@ to some reordering from the compiler and CPUs is beside the point.
But suppose that the reader needs a consistent view? But suppose that the reader needs a consistent view?
Then one approach is to use locking, for example, as follows: Then one approach is to use locking, for example, as follows::
struct foo { struct foo {
int a; int a;
@@ -299,6 +303,7 @@ As always, use the right tool for the job!
EXAMPLE WHERE THE COMPILER KNOWS TOO MUCH EXAMPLE WHERE THE COMPILER KNOWS TOO MUCH
-----------------------------------------
If a pointer obtained from rcu_dereference() compares not-equal to some If a pointer obtained from rcu_dereference() compares not-equal to some
other pointer, the compiler normally has no clue what the value of the other pointer, the compiler normally has no clue what the value of the
@@ -308,7 +313,7 @@ guarantees that RCU depends on. And the volatile cast in rcu_dereference()
should prevent the compiler from guessing the value. should prevent the compiler from guessing the value.
But without rcu_dereference(), the compiler knows more than you might But without rcu_dereference(), the compiler knows more than you might
expect. Consider the following code fragment: expect. Consider the following code fragment::
struct foo { struct foo {
int a; int a;
@@ -354,6 +359,7 @@ dereference the resulting pointer.
WHICH MEMBER OF THE rcu_dereference() FAMILY SHOULD YOU USE? WHICH MEMBER OF THE rcu_dereference() FAMILY SHOULD YOU USE?
------------------------------------------------------------
First, please avoid using rcu_dereference_raw() and also please avoid First, please avoid using rcu_dereference_raw() and also please avoid
using rcu_dereference_check() and rcu_dereference_protected() with a using rcu_dereference_check() and rcu_dereference_protected() with a
@@ -370,7 +376,7 @@ member of the rcu_dereference() to use in various situations:
2. If the access might be within an RCU read-side critical section 2. If the access might be within an RCU read-side critical section
on the one hand, or protected by (say) my_lock on the other, on the one hand, or protected by (say) my_lock on the other,
use rcu_dereference_check(), for example: use rcu_dereference_check(), for example::
p1 = rcu_dereference_check(p->rcu_protected_pointer, p1 = rcu_dereference_check(p->rcu_protected_pointer,
lockdep_is_held(&my_lock)); lockdep_is_held(&my_lock));
@@ -378,14 +384,14 @@ member of the rcu_dereference() to use in various situations:
3. If the access might be within an RCU read-side critical section 3. If the access might be within an RCU read-side critical section
on the one hand, or protected by either my_lock or your_lock on on the one hand, or protected by either my_lock or your_lock on
the other, again use rcu_dereference_check(), for example: the other, again use rcu_dereference_check(), for example::
p1 = rcu_dereference_check(p->rcu_protected_pointer, p1 = rcu_dereference_check(p->rcu_protected_pointer,
lockdep_is_held(&my_lock) || lockdep_is_held(&my_lock) ||
lockdep_is_held(&your_lock)); lockdep_is_held(&your_lock));
4. If the access is on the update side, so that it is always protected 4. If the access is on the update side, so that it is always protected
by my_lock, use rcu_dereference_protected(): by my_lock, use rcu_dereference_protected()::
p1 = rcu_dereference_protected(p->rcu_protected_pointer, p1 = rcu_dereference_protected(p->rcu_protected_pointer,
lockdep_is_held(&my_lock)); lockdep_is_held(&my_lock));
@@ -410,18 +416,19 @@ member of the rcu_dereference() to use in various situations:
SPARSE CHECKING OF RCU-PROTECTED POINTERS SPARSE CHECKING OF RCU-PROTECTED POINTERS
-----------------------------------------
The sparse static-analysis tool checks for direct access to RCU-protected The sparse static-analysis tool checks for direct access to RCU-protected
pointers, which can result in "interesting" bugs due to compiler pointers, which can result in "interesting" bugs due to compiler
optimizations involving invented loads and perhaps also load tearing. optimizations involving invented loads and perhaps also load tearing.
For example, suppose someone mistakenly does something like this: For example, suppose someone mistakenly does something like this::
p = q->rcu_protected_pointer; p = q->rcu_protected_pointer;
do_something_with(p->a); do_something_with(p->a);
do_something_else_with(p->b); do_something_else_with(p->b);
If register pressure is high, the compiler might optimize "p" out If register pressure is high, the compiler might optimize "p" out
of existence, transforming the code to something like this: of existence, transforming the code to something like this::
do_something_with(q->rcu_protected_pointer->a); do_something_with(q->rcu_protected_pointer->a);
do_something_else_with(q->rcu_protected_pointer->b); do_something_else_with(q->rcu_protected_pointer->b);
@@ -435,7 +442,7 @@ Load tearing could of course result in dereferencing a mashup of a pair
of pointers, which also might fatally disappoint your code. of pointers, which also might fatally disappoint your code.
These problems could have been avoided simply by making the code instead These problems could have been avoided simply by making the code instead
read as follows: read as follows::
p = rcu_dereference(q->rcu_protected_pointer); p = rcu_dereference(q->rcu_protected_pointer);
do_something_with(p->a); do_something_with(p->a);
@@ -448,7 +455,7 @@ or as a formal parameter, with "__rcu", which tells sparse to complain if
this pointer is accessed directly. It will also cause sparse to complain this pointer is accessed directly. It will also cause sparse to complain
if a pointer not marked with "__rcu" is accessed using rcu_dereference() if a pointer not marked with "__rcu" is accessed using rcu_dereference()
and friends. For example, ->rcu_protected_pointer might be declared as and friends. For example, ->rcu_protected_pointer might be declared as
follows: follows::
struct foo __rcu *rcu_protected_pointer; struct foo __rcu *rcu_protected_pointer;

222
Documentation/RCU/rcubarrier.txt → Documentation/RCU/rcubarrier.rst
View File

@@ -1,4 +1,7 @@
.. _rcu_barrier:
RCU and Unloadable Modules RCU and Unloadable Modules
==========================
[Originally published in LWN Jan. 14, 2007: http://lwn.net/Articles/217484/] [Originally published in LWN Jan. 14, 2007: http://lwn.net/Articles/217484/]
@@ -21,7 +24,7 @@ given that readers might well leave absolutely no trace of their
presence? There is a synchronize_rcu() primitive that blocks until all presence? There is a synchronize_rcu() primitive that blocks until all
pre-existing readers have completed. An updater wishing to delete an pre-existing readers have completed. An updater wishing to delete an
element p from a linked list might do the following, while holding an element p from a linked list might do the following, while holding an
appropriate lock, of course: appropriate lock, of course::
list_del_rcu(p); list_del_rcu(p);
synchronize_rcu(); synchronize_rcu();
@@ -32,13 +35,13 @@ primitive must be used instead. This primitive takes a pointer to an
rcu_head struct placed within the RCU-protected data structure and rcu_head struct placed within the RCU-protected data structure and
another pointer to a function that may be invoked later to free that another pointer to a function that may be invoked later to free that
structure. Code to delete an element p from the linked list from IRQ structure. Code to delete an element p from the linked list from IRQ
context might then be as follows: context might then be as follows::
list_del_rcu(p); list_del_rcu(p);
call_rcu(&p->rcu, p_callback); call_rcu(&p->rcu, p_callback);
Since call_rcu() never blocks, this code can safely be used from within Since call_rcu() never blocks, this code can safely be used from within
IRQ context. The function p_callback() might be defined as follows: IRQ context. The function p_callback() might be defined as follows::
static void p_callback(struct rcu_head *rp) static void p_callback(struct rcu_head *rp)
{ {
@@ -49,6 +52,7 @@ IRQ context. The function p_callback() might be defined as follows:
Unloading Modules That Use call_rcu() Unloading Modules That Use call_rcu()
-------------------------------------
But what if p_callback is defined in an unloadable module? But what if p_callback is defined in an unloadable module?
@@ -69,10 +73,11 @@ in realtime kernels in order to avoid excessive scheduling latencies.
rcu_barrier() rcu_barrier()
-------------
We instead need the rcu_barrier() primitive. Rather than waiting for We instead need the rcu_barrier() primitive. Rather than waiting for
a grace period to elapse, rcu_barrier() waits for all outstanding RCU a grace period to elapse, rcu_barrier() waits for all outstanding RCU
callbacks to complete. Please note that rcu_barrier() does -not- imply callbacks to complete. Please note that rcu_barrier() does **not** imply
synchronize_rcu(), in particular, if there are no RCU callbacks queued synchronize_rcu(), in particular, if there are no RCU callbacks queued
anywhere, rcu_barrier() is within its rights to return immediately, anywhere, rcu_barrier() is within its rights to return immediately,
without waiting for a grace period to elapse. without waiting for a grace period to elapse.
@@ -88,79 +93,79 @@ must match the flavor of rcu_barrier() with that of call_rcu(). If your
module uses multiple flavors of call_rcu(), then it must also use multiple module uses multiple flavors of call_rcu(), then it must also use multiple
flavors of rcu_barrier() when unloading that module. For example, if flavors of rcu_barrier() when unloading that module. For example, if
it uses call_rcu(), call_srcu() on srcu_struct_1, and call_srcu() on it uses call_rcu(), call_srcu() on srcu_struct_1, and call_srcu() on
srcu_struct_2(), then the following three lines of code will be required srcu_struct_2, then the following three lines of code will be required
when unloading: when unloading::
1 rcu_barrier(); 1 rcu_barrier();
2 srcu_barrier(&srcu_struct_1); 2 srcu_barrier(&srcu_struct_1);
3 srcu_barrier(&srcu_struct_2); 3 srcu_barrier(&srcu_struct_2);
The rcutorture module makes use of rcu_barrier() in its exit function The rcutorture module makes use of rcu_barrier() in its exit function
as follows: as follows::
1 static void 1 static void
2 rcu_torture_cleanup(void) 2 rcu_torture_cleanup(void)
3 { 3 {
4 int i; 4 int i;
5 5
6 fullstop = 1; 6 fullstop = 1;
7 if (shuffler_task != NULL) { 7 if (shuffler_task != NULL) {
8 VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task"); 8 VERBOSE_PRINTK_STRING("Stopping rcu_torture_shuffle task");
9 kthread_stop(shuffler_task); 9 kthread_stop(shuffler_task);
10 } 10 }
11 shuffler_task = NULL; 11 shuffler_task = NULL;
12 12
13 if (writer_task != NULL) { 13 if (writer_task != NULL) {
14 VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task"); 14 VERBOSE_PRINTK_STRING("Stopping rcu_torture_writer task");
15 kthread_stop(writer_task); 15 kthread_stop(writer_task);
16 } 16 }
17 writer_task = NULL; 17 writer_task = NULL;
18 18
19 if (reader_tasks != NULL) { 19 if (reader_tasks != NULL) {
20 for (i = 0; i < nrealreaders; i++) { 20 for (i = 0; i < nrealreaders; i++) {
21 if (reader_tasks[i] != NULL) { 21 if (reader_tasks[i] != NULL) {
22 VERBOSE_PRINTK_STRING( 22 VERBOSE_PRINTK_STRING(
23 "Stopping rcu_torture_reader task"); 23 "Stopping rcu_torture_reader task");
24 kthread_stop(reader_tasks[i]); 24 kthread_stop(reader_tasks[i]);
25 } 25 }
26 reader_tasks[i] = NULL; 26 reader_tasks[i] = NULL;
27 } 27 }
28 kfree(reader_tasks); 28 kfree(reader_tasks);
29 reader_tasks = NULL; 29 reader_tasks = NULL;
30 } 30 }
31 rcu_torture_current = NULL; 31 rcu_torture_current = NULL;
32 32
33 if (fakewriter_tasks != NULL) { 33 if (fakewriter_tasks != NULL) {
34 for (i = 0; i < nfakewriters; i++) { 34 for (i = 0; i < nfakewriters; i++) {
35 if (fakewriter_tasks[i] != NULL) { 35 if (fakewriter_tasks[i] != NULL) {
36 VERBOSE_PRINTK_STRING( 36 VERBOSE_PRINTK_STRING(
37 "Stopping rcu_torture_fakewriter task"); 37 "Stopping rcu_torture_fakewriter task");
38 kthread_stop(fakewriter_tasks[i]); 38 kthread_stop(fakewriter_tasks[i]);
39 } 39 }
40 fakewriter_tasks[i] = NULL; 40 fakewriter_tasks[i] = NULL;
41 } 41 }
42 kfree(fakewriter_tasks); 42 kfree(fakewriter_tasks);
43 fakewriter_tasks = NULL; 43 fakewriter_tasks = NULL;
44 } 44 }
45 45
46 if (stats_task != NULL) { 46 if (stats_task != NULL) {
47 VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task"); 47 VERBOSE_PRINTK_STRING("Stopping rcu_torture_stats task");
48 kthread_stop(stats_task); 48 kthread_stop(stats_task);
49 } 49 }
50 stats_task = NULL; 50 stats_task = NULL;
51 51
52 /* Wait for all RCU callbacks to fire. */ 52 /* Wait for all RCU callbacks to fire. */
53 rcu_barrier(); 53 rcu_barrier();
54 54
55 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */ 55 rcu_torture_stats_print(); /* -After- the stats thread is stopped! */
56 56
57 if (cur_ops->cleanup != NULL) 57 if (cur_ops->cleanup != NULL)
58 cur_ops->cleanup(); 58 cur_ops->cleanup();
59 if (atomic_read(&n_rcu_torture_error)) 59 if (atomic_read(&n_rcu_torture_error))
60 rcu_torture_print_module_parms("End of test: FAILURE"); 60 rcu_torture_print_module_parms("End of test: FAILURE");
61 else 61 else
62 rcu_torture_print_module_parms("End of test: SUCCESS"); 62 rcu_torture_print_module_parms("End of test: SUCCESS");
63 } 63 }
Line 6 sets a global variable that prevents any RCU callbacks from Line 6 sets a global variable that prevents any RCU callbacks from
re-posting themselves. This will not be necessary in most cases, since re-posting themselves. This will not be necessary in most cases, since
@@ -176,9 +181,14 @@ for any pre-existing callbacks to complete.
Then lines 55-62 print status and do operation-specific cleanup, and Then lines 55-62 print status and do operation-specific cleanup, and
then return, permitting the module-unload operation to be completed. then return, permitting the module-unload operation to be completed.
Quick Quiz #1: Is there any other situation where rcu_barrier() might .. _rcubarrier_quiz_1:
Quick Quiz #1:
Is there any other situation where rcu_barrier() might
be required? be required?
:ref:`Answer to Quick Quiz #1 <answer_rcubarrier_quiz_1>`
Your module might have additional complications. For example, if your Your module might have additional complications. For example, if your
module invokes call_rcu() from timers, you will need to first cancel all module invokes call_rcu() from timers, you will need to first cancel all
the timers, and only then invoke rcu_barrier() to wait for any remaining the timers, and only then invoke rcu_barrier() to wait for any remaining
@@ -188,11 +198,12 @@ Of course, if you module uses call_rcu(), you will need to invoke
rcu_barrier() before unloading. Similarly, if your module uses rcu_barrier() before unloading. Similarly, if your module uses
call_srcu(), you will need to invoke srcu_barrier() before unloading, call_srcu(), you will need to invoke srcu_barrier() before unloading,
and on the same srcu_struct structure. If your module uses call_rcu() and on the same srcu_struct structure. If your module uses call_rcu()
-and- call_srcu(), then you will need to invoke rcu_barrier() -and- **and** call_srcu(), then you will need to invoke rcu_barrier() **and**
srcu_barrier(). srcu_barrier().
Implementing rcu_barrier() Implementing rcu_barrier()
--------------------------
Dipankar Sarma's implementation of rcu_barrier() makes use of the fact Dipankar Sarma's implementation of rcu_barrier() makes use of the fact
that RCU callbacks are never reordered once queued on one of the per-CPU that RCU callbacks are never reordered once queued on one of the per-CPU
@@ -200,19 +211,19 @@ queues. His implementation queues an RCU callback on each of the per-CPU
callback queues, and then waits until they have all started executing, at callback queues, and then waits until they have all started executing, at
which point, all earlier RCU callbacks are guaranteed to have completed. which point, all earlier RCU callbacks are guaranteed to have completed.
The original code for rcu_barrier() was as follows: The original code for rcu_barrier() was as follows::
1 void rcu_barrier(void) 1 void rcu_barrier(void)
2 { 2 {
3 BUG_ON(in_interrupt()); 3 BUG_ON(in_interrupt());
4 /* Take cpucontrol mutex to protect against CPU hotplug */ 4 /* Take cpucontrol mutex to protect against CPU hotplug */
5 mutex_lock(&rcu_barrier_mutex); 5 mutex_lock(&rcu_barrier_mutex);
6 init_completion(&rcu_barrier_completion); 6 init_completion(&rcu_barrier_completion);
7 atomic_set(&rcu_barrier_cpu_count, 0); 7 atomic_set(&rcu_barrier_cpu_count, 0);
8 on_each_cpu(rcu_barrier_func, NULL, 0, 1); 8 on_each_cpu(rcu_barrier_func, NULL, 0, 1);
9 wait_for_completion(&rcu_barrier_completion); 9 wait_for_completion(&rcu_barrier_completion);
10 mutex_unlock(&rcu_barrier_mutex); 10 mutex_unlock(&rcu_barrier_mutex);
11 } 11 }
Line 3 verifies that the caller is in process context, and lines 5 and 10 Line 3 verifies that the caller is in process context, and lines 5 and 10
use rcu_barrier_mutex to ensure that only one rcu_barrier() is using the use rcu_barrier_mutex to ensure that only one rcu_barrier() is using the
@@ -226,18 +237,18 @@ This code was rewritten in 2008 and several times thereafter, but this
still gives the general idea. still gives the general idea.
The rcu_barrier_func() runs on each CPU, where it invokes call_rcu() The rcu_barrier_func() runs on each CPU, where it invokes call_rcu()
to post an RCU callback, as follows: to post an RCU callback, as follows::
1 static void rcu_barrier_func(void *notused) 1 static void rcu_barrier_func(void *notused)
2 { 2 {
3 int cpu = smp_processor_id(); 3 int cpu = smp_processor_id();
4 struct rcu_data *rdp = &per_cpu(rcu_data, cpu); 4 struct rcu_data *rdp = &per_cpu(rcu_data, cpu);
5 struct rcu_head *head; 5 struct rcu_head *head;
6 6
7 head = &rdp->barrier; 7 head = &rdp->barrier;
8 atomic_inc(&rcu_barrier_cpu_count); 8 atomic_inc(&rcu_barrier_cpu_count);
9 call_rcu(head, rcu_barrier_callback); 9 call_rcu(head, rcu_barrier_callback);
10 } 10 }
Lines 3 and 4 locate RCU's internal per-CPU rcu_data structure, Lines 3 and 4 locate RCU's internal per-CPU rcu_data structure,
which contains the struct rcu_head that needed for the later call to which contains the struct rcu_head that needed for the later call to
@@ -248,20 +259,25 @@ the current CPU's queue.
The rcu_barrier_callback() function simply atomically decrements the The rcu_barrier_callback() function simply atomically decrements the
rcu_barrier_cpu_count variable and finalizes the completion when it rcu_barrier_cpu_count variable and finalizes the completion when it
reaches zero, as follows: reaches zero, as follows::
1 static void rcu_barrier_callback(struct rcu_head *notused) 1 static void rcu_barrier_callback(struct rcu_head *notused)
2 { 2 {
3 if (atomic_dec_and_test(&rcu_barrier_cpu_count)) 3 if (atomic_dec_and_test(&rcu_barrier_cpu_count))
4 complete(&rcu_barrier_completion); 4 complete(&rcu_barrier_completion);
5 } 5 }
Quick Quiz #2: What happens if CPU 0's rcu_barrier_func() executes .. _rcubarrier_quiz_2:
Quick Quiz #2:
What happens if CPU 0's rcu_barrier_func() executes
immediately (thus incrementing rcu_barrier_cpu_count to the immediately (thus incrementing rcu_barrier_cpu_count to the
value one), but the other CPU's rcu_barrier_func() invocations value one), but the other CPU's rcu_barrier_func() invocations
are delayed for a full grace period? Couldn't this result in are delayed for a full grace period? Couldn't this result in
rcu_barrier() returning prematurely? rcu_barrier() returning prematurely?
:ref:`Answer to Quick Quiz #2 <answer_rcubarrier_quiz_2>`
The current rcu_barrier() implementation is more complex, due to the need The current rcu_barrier() implementation is more complex, due to the need
to avoid disturbing idle CPUs (especially on battery-powered systems) to avoid disturbing idle CPUs (especially on battery-powered systems)
and the need to minimally disturb non-idle CPUs in real-time systems. and the need to minimally disturb non-idle CPUs in real-time systems.
@@ -269,6 +285,7 @@ However, the code above illustrates the concepts.
rcu_barrier() Summary rcu_barrier() Summary
---------------------
The rcu_barrier() primitive has seen relatively little use, since most The rcu_barrier() primitive has seen relatively little use, since most
code using RCU is in the core kernel rather than in modules. However, if code using RCU is in the core kernel rather than in modules. However, if
@@ -277,8 +294,12 @@ so that your module may be safely unloaded.
Answers to Quick Quizzes Answers to Quick Quizzes
------------------------
Quick Quiz #1: Is there any other situation where rcu_barrier() might .. _answer_rcubarrier_quiz_1:
Quick Quiz #1:
Is there any other situation where rcu_barrier() might
be required? be required?
Answer: Interestingly enough, rcu_barrier() was not originally Answer: Interestingly enough, rcu_barrier() was not originally
@@ -292,7 +313,12 @@ Answer: Interestingly enough, rcu_barrier() was not originally
implementing rcutorture, and found that rcu_barrier() solves implementing rcutorture, and found that rcu_barrier() solves
this problem as well. this problem as well.
Quick Quiz #2: What happens if CPU 0's rcu_barrier_func() executes :ref:`Back to Quick Quiz #1 <rcubarrier_quiz_1>`
.. _answer_rcubarrier_quiz_2:
Quick Quiz #2:
What happens if CPU 0's rcu_barrier_func() executes
immediately (thus incrementing rcu_barrier_cpu_count to the immediately (thus incrementing rcu_barrier_cpu_count to the
value one), but the other CPU's rcu_barrier_func() invocations value one), but the other CPU's rcu_barrier_func() invocations
are delayed for a full grace period? Couldn't this result in are delayed for a full grace period? Couldn't this result in
@@ -323,3 +349,5 @@ Answer: This cannot happen. The reason is that on_each_cpu() has its last
is to add an rcu_read_lock() before line 8 of rcu_barrier() is to add an rcu_read_lock() before line 8 of rcu_barrier()
and an rcu_read_unlock() after line 8 of this same function. If and an rcu_read_unlock() after line 8 of this same function. If
you can think of a better change, please let me know! you can think of a better change, please let me know!
:ref:`Back to Quick Quiz #2 <rcubarrier_quiz_2>`

11
Documentation/RCU/stallwarn.txt
View File

@@ -225,18 +225,13 @@ an estimate of the total number of RCU callbacks queued across all CPUs
In kernels with CONFIG_RCU_FAST_NO_HZ, more information is printed In kernels with CONFIG_RCU_FAST_NO_HZ, more information is printed
for each CPU: for each CPU:
0: (64628 ticks this GP) idle=dd5/3fffffffffffffff/0 softirq=82/543 last_accelerate: a345/d342 Nonlazy posted: ..D 0: (64628 ticks this GP) idle=dd5/3fffffffffffffff/0 softirq=82/543 last_accelerate: a345/d342 dyntick_enabled: 1
The "last_accelerate:" prints the low-order 16 bits (in hex) of the The "last_accelerate:" prints the low-order 16 bits (in hex) of the
jiffies counter when this CPU last invoked rcu_try_advance_all_cbs() jiffies counter when this CPU last invoked rcu_try_advance_all_cbs()
from rcu_needs_cpu() or last invoked rcu_accelerate_cbs() from from rcu_needs_cpu() or last invoked rcu_accelerate_cbs() from
rcu_prepare_for_idle(). The "Nonlazy posted:" indicates lazy-callback rcu_prepare_for_idle(). "dyntick_enabled: 1" indicates that dyntick-idle
status, so that an "l" indicates that all callbacks were lazy at the start processing is enabled.
of the last idle period and an "L" indicates that there are currently
no non-lazy callbacks (in both cases, "." is printed otherwise, as
shown above) and "D" indicates that dyntick-idle processing is enabled
("." is printed otherwise, for example, if disabled via the "nohz="
kernel boot parameter).
If the grace period ends just as the stall warning starts printing, If the grace period ends just as the stall warning starts printing,
there will be a spurious stall-warning message, which will include there will be a spurious stall-warning message, which will include

289
Documentation/RCU/whatisRCU.txt → Documentation/RCU/whatisRCU.rst
View File

@@ -1,15 +1,18 @@
.. _whatisrcu_doc:
What is RCU? -- "Read, Copy, Update" What is RCU? -- "Read, Copy, Update"
======================================
Please note that the "What is RCU?" LWN series is an excellent place Please note that the "What is RCU?" LWN series is an excellent place
to start learning about RCU: to start learning about RCU:
1. What is RCU, Fundamentally? http://lwn.net/Articles/262464/ | 1. What is RCU, Fundamentally? http://lwn.net/Articles/262464/
2. What is RCU? Part 2: Usage http://lwn.net/Articles/263130/ | 2. What is RCU? Part 2: Usage http://lwn.net/Articles/263130/
3. RCU part 3: the RCU API http://lwn.net/Articles/264090/ | 3. RCU part 3: the RCU API http://lwn.net/Articles/264090/
4. The RCU API, 2010 Edition http://lwn.net/Articles/418853/ | 4. The RCU API, 2010 Edition http://lwn.net/Articles/418853/
2010 Big API Table http://lwn.net/Articles/419086/ | 2010 Big API Table http://lwn.net/Articles/419086/
5. The RCU API, 2014 Edition http://lwn.net/Articles/609904/ | 5. The RCU API, 2014 Edition http://lwn.net/Articles/609904/
2014 Big API Table http://lwn.net/Articles/609973/ | 2014 Big API Table http://lwn.net/Articles/609973/
What is RCU? What is RCU?
@@ -24,14 +27,21 @@ the experience has been that different people must take different paths
to arrive at an understanding of RCU. This document provides several to arrive at an understanding of RCU. This document provides several
different paths, as follows: different paths, as follows:
1. RCU OVERVIEW :ref:`1. RCU OVERVIEW <1_whatisRCU>`
2. WHAT IS RCU'S CORE API?
3. WHAT ARE SOME EXAMPLE USES OF CORE RCU API? :ref:`2. WHAT IS RCU'S CORE API? <2_whatisRCU>`
4. WHAT IF MY UPDATING THREAD CANNOT BLOCK?
5. WHAT ARE SOME SIMPLE IMPLEMENTATIONS OF RCU? :ref:`3. WHAT ARE SOME EXAMPLE USES OF CORE RCU API? <3_whatisRCU>`
6. ANALOGY WITH READER-WRITER LOCKING
7. FULL LIST OF RCU APIs :ref:`4. WHAT IF MY UPDATING THREAD CANNOT BLOCK? <4_whatisRCU>`
8. ANSWERS TO QUICK QUIZZES
:ref:`5. WHAT ARE SOME SIMPLE IMPLEMENTATIONS OF RCU? <5_whatisRCU>`
:ref:`6. ANALOGY WITH READER-WRITER LOCKING <6_whatisRCU>`
:ref:`7. FULL LIST OF RCU APIs <7_whatisRCU>`
:ref:`8. ANSWERS TO QUICK QUIZZES <8_whatisRCU>`
People who prefer starting with a conceptual overview should focus on People who prefer starting with a conceptual overview should focus on
Section 1, though most readers will profit by reading this section at Section 1, though most readers will profit by reading this section at
@@ -49,8 +59,10 @@ everything, feel free to read the whole thing -- but if you are really
that type of person, you have perused the source code and will therefore that type of person, you have perused the source code and will therefore
never need this document anyway. ;-) never need this document anyway. ;-)
.. _1_whatisRCU:
1. RCU OVERVIEW 1. RCU OVERVIEW
----------------
The basic idea behind RCU is to split updates into "removal" and The basic idea behind RCU is to split updates into "removal" and
"reclamation" phases. The removal phase removes references to data items "reclamation" phases. The removal phase removes references to data items
@@ -116,8 +128,10 @@ So how the heck can a reclaimer tell when a reader is done, given
that readers are not doing any sort of synchronization operations??? that readers are not doing any sort of synchronization operations???
Read on to learn about how RCU's API makes this easy. Read on to learn about how RCU's API makes this easy.
.. _2_whatisRCU:
2. WHAT IS RCU'S CORE API? 2. WHAT IS RCU'S CORE API?
---------------------------
The core RCU API is quite small: The core RCU API is quite small:
@@ -136,7 +150,7 @@ later. See the kernel docbook documentation for more info, or look directly
at the function header comments. at the function header comments.
rcu_read_lock() rcu_read_lock()
^^^^^^^^^^^^^^^
void rcu_read_lock(void); void rcu_read_lock(void);
Used by a reader to inform the reclaimer that the reader is Used by a reader to inform the reclaimer that the reader is
@@ -150,7 +164,7 @@ rcu_read_lock()
longer-term references to data structures. longer-term references to data structures.
rcu_read_unlock() rcu_read_unlock()
^^^^^^^^^^^^^^^^^
void rcu_read_unlock(void); void rcu_read_unlock(void);
Used by a reader to inform the reclaimer that the reader is Used by a reader to inform the reclaimer that the reader is
@@ -158,15 +172,15 @@ rcu_read_unlock()
read-side critical sections may be nested and/or overlapping. read-side critical sections may be nested and/or overlapping.
synchronize_rcu() synchronize_rcu()
^^^^^^^^^^^^^^^^^
void synchronize_rcu(void); void synchronize_rcu(void);
Marks the end of updater code and the beginning of reclaimer Marks the end of updater code and the beginning of reclaimer
code. It does this by blocking until all pre-existing RCU code. It does this by blocking until all pre-existing RCU
read-side critical sections on all CPUs have completed. read-side critical sections on all CPUs have completed.
Note that synchronize_rcu() will -not- necessarily wait for Note that synchronize_rcu() will **not** necessarily wait for
any subsequent RCU read-side critical sections to complete. any subsequent RCU read-side critical sections to complete.
For example, consider the following sequence of events: For example, consider the following sequence of events::
CPU 0 CPU 1 CPU 2 CPU 0 CPU 1 CPU 2
----------------- ------------------------- --------------- ----------------- ------------------------- ---------------
@@ -182,7 +196,7 @@ synchronize_rcu()
any that begin after synchronize_rcu() is invoked. any that begin after synchronize_rcu() is invoked.
Of course, synchronize_rcu() does not necessarily return Of course, synchronize_rcu() does not necessarily return
-immediately- after the last pre-existing RCU read-side critical **immediately** after the last pre-existing RCU read-side critical
section completes. For one thing, there might well be scheduling section completes. For one thing, there might well be scheduling
delays. For another thing, many RCU implementations process delays. For another thing, many RCU implementations process
requests in batches in order to improve efficiencies, which can requests in batches in order to improve efficiencies, which can
@@ -211,10 +225,10 @@ synchronize_rcu()
checklist.txt for some approaches to limiting the update rate. checklist.txt for some approaches to limiting the update rate.
rcu_assign_pointer() rcu_assign_pointer()
^^^^^^^^^^^^^^^^^^^^
void rcu_assign_pointer(p, typeof(p) v); void rcu_assign_pointer(p, typeof(p) v);
Yes, rcu_assign_pointer() -is- implemented as a macro, though it Yes, rcu_assign_pointer() **is** implemented as a macro, though it
would be cool to be able to declare a function in this manner. would be cool to be able to declare a function in this manner.
(Compiler experts will no doubt disagree.) (Compiler experts will no doubt disagree.)
@@ -231,7 +245,7 @@ rcu_assign_pointer()
the _rcu list-manipulation primitives such as list_add_rcu(). the _rcu list-manipulation primitives such as list_add_rcu().
rcu_dereference() rcu_dereference()
^^^^^^^^^^^^^^^^^
typeof(p) rcu_dereference(p); typeof(p) rcu_dereference(p);
Like rcu_assign_pointer(), rcu_dereference() must be implemented Like rcu_assign_pointer(), rcu_dereference() must be implemented
@@ -248,13 +262,13 @@ rcu_dereference()
Common coding practice uses rcu_dereference() to copy an Common coding practice uses rcu_dereference() to copy an
RCU-protected pointer to a local variable, then dereferences RCU-protected pointer to a local variable, then dereferences
this local variable, for example as follows: this local variable, for example as follows::
p = rcu_dereference(head.next); p = rcu_dereference(head.next);
return p->data; return p->data;
However, in this case, one could just as easily combine these However, in this case, one could just as easily combine these
into one statement: into one statement::
return rcu_dereference(head.next)->data; return rcu_dereference(head.next)->data;
@@ -266,8 +280,8 @@ rcu_dereference()
unnecessary overhead on Alpha CPUs. unnecessary overhead on Alpha CPUs.
Note that the value returned by rcu_dereference() is valid Note that the value returned by rcu_dereference() is valid
only within the enclosing RCU read-side critical section [1]. only within the enclosing RCU read-side critical section [1]_.
For example, the following is -not- legal: For example, the following is **not** legal::
rcu_read_lock(); rcu_read_lock();
p = rcu_dereference(head.next); p = rcu_dereference(head.next);
@@ -290,9 +304,9 @@ rcu_dereference()
at any time, including immediately after the rcu_dereference(). at any time, including immediately after the rcu_dereference().
And, again like rcu_assign_pointer(), rcu_dereference() is And, again like rcu_assign_pointer(), rcu_dereference() is
typically used indirectly, via the _rcu list-manipulation typically used indirectly, via the _rcu list-manipulation
primitives, such as list_for_each_entry_rcu() [2]. primitives, such as list_for_each_entry_rcu() [2]_.
[1] The variant rcu_dereference_protected() can be used outside .. [1] The variant rcu_dereference_protected() can be used outside
of an RCU read-side critical section as long as the usage is of an RCU read-side critical section as long as the usage is
protected by locks acquired by the update-side code. This variant protected by locks acquired by the update-side code. This variant
avoids the lockdep warning that would happen when using (for avoids the lockdep warning that would happen when using (for
@@ -305,7 +319,7 @@ rcu_dereference()
a lockdep splat is emitted. See Documentation/RCU/Design/Requirements/Requirements.rst a lockdep splat is emitted. See Documentation/RCU/Design/Requirements/Requirements.rst
and the API's code comments for more details and example usage. and the API's code comments for more details and example usage.
[2] If the list_for_each_entry_rcu() instance might be used by .. [2] If the list_for_each_entry_rcu() instance might be used by
update-side code as well as by RCU readers, then an additional update-side code as well as by RCU readers, then an additional
lockdep expression can be added to its list of arguments. lockdep expression can be added to its list of arguments.
For example, given an additional "lock_is_held(&mylock)" argument, For example, given an additional "lock_is_held(&mylock)" argument,
@@ -315,6 +329,7 @@ rcu_dereference()
The following diagram shows how each API communicates among the The following diagram shows how each API communicates among the
reader, updater, and reclaimer. reader, updater, and reclaimer.
::
rcu_assign_pointer() rcu_assign_pointer()
@@ -375,12 +390,16 @@ c. RCU applied to scheduler and interrupt/NMI-handler tasks.
Again, most uses will be of (a). The (b) and (c) cases are important Again, most uses will be of (a). The (b) and (c) cases are important
for specialized uses, but are relatively uncommon. for specialized uses, but are relatively uncommon.
.. _3_whatisRCU:
3. WHAT ARE SOME EXAMPLE USES OF CORE RCU API? 3. WHAT ARE SOME EXAMPLE USES OF CORE RCU API?
-----------------------------------------------
This section shows a simple use of the core RCU API to protect a This section shows a simple use of the core RCU API to protect a
global pointer to a dynamically allocated structure. More-typical global pointer to a dynamically allocated structure. More-typical
uses of RCU may be found in listRCU.txt, arrayRCU.txt, and NMI-RCU.txt. uses of RCU may be found in :ref:`listRCU.rst <list_rcu_doc>`,
:ref:`arrayRCU.rst <array_rcu_doc>`, and :ref:`NMI-RCU.rst <NMI_rcu_doc>`.
::
struct foo { struct foo {
int a; int a;
@@ -440,40 +459,43 @@ uses of RCU may be found in listRCU.txt, arrayRCU.txt, and NMI-RCU.txt.
So, to sum up: So, to sum up:
o Use rcu_read_lock() and rcu_read_unlock() to guard RCU - Use rcu_read_lock() and rcu_read_unlock() to guard RCU
read-side critical sections. read-side critical sections.
o Within an RCU read-side critical section, use rcu_dereference() - Within an RCU read-side critical section, use rcu_dereference()
to dereference RCU-protected pointers. to dereference RCU-protected pointers.
o Use some solid scheme (such as locks or semaphores) to - Use some solid scheme (such as locks or semaphores) to
keep concurrent updates from interfering with each other. keep concurrent updates from interfering with each other.
o Use rcu_assign_pointer() to update an RCU-protected pointer. - Use rcu_assign_pointer() to update an RCU-protected pointer.
This primitive protects concurrent readers from the updater, This primitive protects concurrent readers from the updater,
-not- concurrent updates from each other! You therefore still **not** concurrent updates from each other! You therefore still
need to use locking (or something similar) to keep concurrent need to use locking (or something similar) to keep concurrent
rcu_assign_pointer() primitives from interfering with each other. rcu_assign_pointer() primitives from interfering with each other.
o Use synchronize_rcu() -after- removing a data element from an - Use synchronize_rcu() **after** removing a data element from an
RCU-protected data structure, but -before- reclaiming/freeing RCU-protected data structure, but **before** reclaiming/freeing
the data element, in order to wait for the completion of all the data element, in order to wait for the completion of all
RCU read-side critical sections that might be referencing that RCU read-side critical sections that might be referencing that
data item. data item.
See checklist.txt for additional rules to follow when using RCU. See checklist.txt for additional rules to follow when using RCU.
And again, more-typical uses of RCU may be found in listRCU.txt, And again, more-typical uses of RCU may be found in :ref:`listRCU.rst
arrayRCU.txt, and NMI-RCU.txt. <list_rcu_doc>`, :ref:`arrayRCU.rst <array_rcu_doc>`, and :ref:`NMI-RCU.rst
<NMI_rcu_doc>`.
.. _4_whatisRCU:
4. WHAT IF MY UPDATING THREAD CANNOT BLOCK? 4. WHAT IF MY UPDATING THREAD CANNOT BLOCK?
--------------------------------------------
In the example above, foo_update_a() blocks until a grace period elapses. In the example above, foo_update_a() blocks until a grace period elapses.
This is quite simple, but in some cases one cannot afford to wait so This is quite simple, but in some cases one cannot afford to wait so
long -- there might be other high-priority work to be done. long -- there might be other high-priority work to be done.
In such cases, one uses call_rcu() rather than synchronize_rcu(). In such cases, one uses call_rcu() rather than synchronize_rcu().
The call_rcu() API is as follows: The call_rcu() API is as follows::
void call_rcu(struct rcu_head * head, void call_rcu(struct rcu_head * head,
void (*func)(struct rcu_head *head)); void (*func)(struct rcu_head *head));
@@ -481,7 +503,7 @@ The call_rcu() API is as follows:
This function invokes func(head) after a grace period has elapsed. This function invokes func(head) after a grace period has elapsed.
This invocation might happen from either softirq or process context, This invocation might happen from either softirq or process context,
so the function is not permitted to block. The foo struct needs to so the function is not permitted to block. The foo struct needs to
have an rcu_head structure added, perhaps as follows: have an rcu_head structure added, perhaps as follows::
struct foo { struct foo {
int a; int a;
@@ -490,7 +512,7 @@ have an rcu_head structure added, perhaps as follows:
struct rcu_head rcu; struct rcu_head rcu;
}; };
The foo_update_a() function might then be written as follows: The foo_update_a() function might then be written as follows::
/* /*
* Create a new struct foo that is the same as the one currently * Create a new struct foo that is the same as the one currently
@@ -520,7 +542,7 @@ The foo_update_a() function might then be written as follows:
call_rcu(&old_fp->rcu, foo_reclaim); call_rcu(&old_fp->rcu, foo_reclaim);
} }
The foo_reclaim() function might appear as follows: The foo_reclaim() function might appear as follows::
void foo_reclaim(struct rcu_head *rp) void foo_reclaim(struct rcu_head *rp)
{ {
@@ -544,7 +566,7 @@ namely foo_reclaim().
The summary of advice is the same as for the previous section, except The summary of advice is the same as for the previous section, except
that we are now using call_rcu() rather than synchronize_rcu(): that we are now using call_rcu() rather than synchronize_rcu():
o Use call_rcu() -after- removing a data element from an - Use call_rcu() **after** removing a data element from an
RCU-protected data structure in order to register a callback RCU-protected data structure in order to register a callback
function that will be invoked after the completion of all RCU function that will be invoked after the completion of all RCU
read-side critical sections that might be referencing that read-side critical sections that might be referencing that
@@ -552,14 +574,16 @@ o Use call_rcu() -after- removing a data element from an
If the callback for call_rcu() is not doing anything more than calling If the callback for call_rcu() is not doing anything more than calling
kfree() on the structure, you can use kfree_rcu() instead of call_rcu() kfree() on the structure, you can use kfree_rcu() instead of call_rcu()
to avoid having to write your own callback: to avoid having to write your own callback::
kfree_rcu(old_fp, rcu); kfree_rcu(old_fp, rcu);
Again, see checklist.txt for additional rules governing the use of RCU. Again, see checklist.txt for additional rules governing the use of RCU.
.. _5_whatisRCU:
5. WHAT ARE SOME SIMPLE IMPLEMENTATIONS OF RCU? 5. WHAT ARE SOME SIMPLE IMPLEMENTATIONS OF RCU?
------------------------------------------------
One of the nice things about RCU is that it has extremely simple "toy" One of the nice things about RCU is that it has extremely simple "toy"
implementations that are a good first step towards understanding the implementations that are a good first step towards understanding the
@@ -579,7 +603,7 @@ more details on the current implementation as of early 2004.
5A. "TOY" IMPLEMENTATION #1: LOCKING 5A. "TOY" IMPLEMENTATION #1: LOCKING
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This section presents a "toy" RCU implementation that is based on This section presents a "toy" RCU implementation that is based on
familiar locking primitives. Its overhead makes it a non-starter for familiar locking primitives. Its overhead makes it a non-starter for
real-life use, as does its lack of scalability. It is also unsuitable real-life use, as does its lack of scalability. It is also unsuitable
@@ -591,7 +615,7 @@ you allow nested rcu_read_lock() calls, you can deadlock.
However, it is probably the easiest implementation to relate to, so is However, it is probably the easiest implementation to relate to, so is
a good starting point. a good starting point.
It is extremely simple: It is extremely simple::
static DEFINE_RWLOCK(rcu_gp_mutex); static DEFINE_RWLOCK(rcu_gp_mutex);
@@ -614,7 +638,7 @@ It is extremely simple:
[You can ignore rcu_assign_pointer() and rcu_dereference() without missing [You can ignore rcu_assign_pointer() and rcu_dereference() without missing
much. But here are simplified versions anyway. And whatever you do, much. But here are simplified versions anyway. And whatever you do,
don't forget about them when submitting patches making use of RCU!] don't forget about them when submitting patches making use of RCU!]::
#define rcu_assign_pointer(p, v) \ #define rcu_assign_pointer(p, v) \
({ \ ({ \
@@ -647,18 +671,23 @@ that the only thing that can block rcu_read_lock() is a synchronize_rcu().
But synchronize_rcu() does not acquire any locks while holding rcu_gp_mutex, But synchronize_rcu() does not acquire any locks while holding rcu_gp_mutex,
so there can be no deadlock cycle. so there can be no deadlock cycle.
Quick Quiz #1: Why is this argument naive? How could a deadlock .. _quiz_1:
Quick Quiz #1:
Why is this argument naive? How could a deadlock
occur when using this algorithm in a real-world Linux occur when using this algorithm in a real-world Linux
kernel? How could this deadlock be avoided? kernel? How could this deadlock be avoided?
:ref:`Answers to Quick Quiz <8_whatisRCU>`
5B. "TOY" EXAMPLE #2: CLASSIC RCU 5B. "TOY" EXAMPLE #2: CLASSIC RCU
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
This section presents a "toy" RCU implementation that is based on This section presents a "toy" RCU implementation that is based on
"classic RCU". It is also short on performance (but only for updates) and "classic RCU". It is also short on performance (but only for updates) and
on features such as hotplug CPU and the ability to run in CONFIG_PREEMPT on features such as hotplug CPU and the ability to run in CONFIG_PREEMPT
kernels. The definitions of rcu_dereference() and rcu_assign_pointer() kernels. The definitions of rcu_dereference() and rcu_assign_pointer()
are the same as those shown in the preceding section, so they are omitted. are the same as those shown in the preceding section, so they are omitted.
::
void rcu_read_lock(void) { } void rcu_read_lock(void) { }
@@ -683,14 +712,14 @@ CPU in turn. The run_on() primitive can be implemented straightforwardly
in terms of the sched_setaffinity() primitive. Of course, a somewhat less in terms of the sched_setaffinity() primitive. Of course, a somewhat less
"toy" implementation would restore the affinity upon completion rather "toy" implementation would restore the affinity upon completion rather
than just leaving all tasks running on the last CPU, but when I said than just leaving all tasks running on the last CPU, but when I said
"toy", I meant -toy-! "toy", I meant **toy**!
So how the heck is this supposed to work??? So how the heck is this supposed to work???
Remember that it is illegal to block while in an RCU read-side critical Remember that it is illegal to block while in an RCU read-side critical
section. Therefore, if a given CPU executes a context switch, we know section. Therefore, if a given CPU executes a context switch, we know
that it must have completed all preceding RCU read-side critical sections. that it must have completed all preceding RCU read-side critical sections.
Once -all- CPUs have executed a context switch, then -all- preceding Once **all** CPUs have executed a context switch, then **all** preceding
RCU read-side critical sections will have completed. RCU read-side critical sections will have completed.
So, suppose that we remove a data item from its structure and then invoke So, suppose that we remove a data item from its structure and then invoke
@@ -698,19 +727,32 @@ synchronize_rcu(). Once synchronize_rcu() returns, we are guaranteed
that there are no RCU read-side critical sections holding a reference that there are no RCU read-side critical sections holding a reference
to that data item, so we can safely reclaim it. to that data item, so we can safely reclaim it.
Quick Quiz #2: Give an example where Classic RCU's read-side .. _quiz_2:
overhead is -negative-.
Quick Quiz #3: If it is illegal to block in an RCU read-side Quick Quiz #2:
Give an example where Classic RCU's read-side
overhead is **negative**.
:ref:`Answers to Quick Quiz <8_whatisRCU>`
.. _quiz_3:
Quick Quiz #3:
If it is illegal to block in an RCU read-side
critical section, what the heck do you do in critical section, what the heck do you do in
PREEMPT_RT, where normal spinlocks can block??? PREEMPT_RT, where normal spinlocks can block???
:ref:`Answers to Quick Quiz <8_whatisRCU>`
.. _6_whatisRCU:
6. ANALOGY WITH READER-WRITER LOCKING 6. ANALOGY WITH READER-WRITER LOCKING
--------------------------------------
Although RCU can be used in many different ways, a very common use of Although RCU can be used in many different ways, a very common use of
RCU is analogous to reader-writer locking. The following unified RCU is analogous to reader-writer locking. The following unified
diff shows how closely related RCU and reader-writer locking can be. diff shows how closely related RCU and reader-writer locking can be.
::
@@ -5,5 +5,5 @@ struct el { @@ -5,5 +5,5 @@ struct el {
int data; int data;
@@ -762,7 +804,7 @@ diff shows how closely related RCU and reader-writer locking can be.
return 0; return 0;
} }
Or, for those who prefer a side-by-side listing: Or, for those who prefer a side-by-side listing::
1 struct el { 1 struct el { 1 struct el { 1 struct el {
2 struct list_head list; 2 struct list_head list; 2 struct list_head list; 2 struct list_head list;
@@ -774,40 +816,44 @@ Or, for those who prefer a side-by-side listing:
8 rwlock_t listmutex; 8 spinlock_t listmutex; 8 rwlock_t listmutex; 8 spinlock_t listmutex;
9 struct el head; 9 struct el head; 9 struct el head; 9 struct el head;
1 int search(long key, int *result) 1 int search(long key, int *result) ::
2 { 2 {
3 struct list_head *lp; 3 struct list_head *lp;
4 struct el *p; 4 struct el *p;
5 5
6 read_lock(&listmutex); 6 rcu_read_lock();
7 list_for_each_entry(p, head, lp) { 7 list_for_each_entry_rcu(p, head, lp) {
8 if (p->key == key) { 8 if (p->key == key) {
9 *result = p->data; 9 *result = p->data;
10 read_unlock(&listmutex); 10 rcu_read_unlock();
11 return 1; 11 return 1;
12 } 12 }
13 } 13 }
14 read_unlock(&listmutex); 14 rcu_read_unlock();
15 return 0; 15 return 0;
16 } 16 }
1 int delete(long key) 1 int delete(long key) 1 int search(long key, int *result) 1 int search(long key, int *result)
2 { 2 { 2 { 2 {
3 struct el *p; 3 struct el *p; 3 struct list_head *lp; 3 struct list_head *lp;
4 4 4 struct el *p; 4 struct el *p;
5 write_lock(&listmutex); 5 spin_lock(&listmutex); 5 5
6 list_for_each_entry(p, head, lp) { 6 list_for_each_entry(p, head, lp) { 6 read_lock(&listmutex); 6 rcu_read_lock();
7 if (p->key == key) { 7 if (p->key == key) { 7 list_for_each_entry(p, head, lp) { 7 list_for_each_entry_rcu(p, head, lp) {
8 list_del(&p->list); 8 list_del_rcu(&p->list); 8 if (p->key == key) { 8 if (p->key == key) {
9 write_unlock(&listmutex); 9 spin_unlock(&listmutex); 9 *result = p->data; 9 *result = p->data;
10 synchronize_rcu(); 10 read_unlock(&listmutex); 10 rcu_read_unlock();
10 kfree(p); 11 kfree(p); 11 return 1; 11 return 1;
11 return 1; 12 return 1; 12 } 12 }
12 } 13 } 13 } 13 }
13 } 14 } 14 read_unlock(&listmutex); 14 rcu_read_unlock();
14 write_unlock(&listmutex); 15 spin_unlock(&listmutex); 15 return 0; 15 return 0;
15 return 0; 16 return 0; 16 } 16 }
16 } 17 }
::
1 int delete(long key) 1 int delete(long key)
2 { 2 {
3 struct el *p; 3 struct el *p;
4 4
5 write_lock(&listmutex); 5 spin_lock(&listmutex);
6 list_for_each_entry(p, head, lp) { 6 list_for_each_entry(p, head, lp) {
7 if (p->key == key) { 7 if (p->key == key) {
8 list_del(&p->list); 8 list_del_rcu(&p->list);
9 write_unlock(&listmutex); 9 spin_unlock(&listmutex);
10 synchronize_rcu();
10 kfree(p); 11 kfree(p);
11 return 1; 12 return 1;
12 } 13 }
13 } 14 }
14 write_unlock(&listmutex); 15 spin_unlock(&listmutex);
15 return 0; 16 return 0;
16 } 17 }
Either way, the differences are quite small. Read-side locking moves Either way, the differences are quite small. Read-side locking moves
to rcu_read_lock() and rcu_read_unlock, update-side locking moves from to rcu_read_lock() and rcu_read_unlock, update-side locking moves from
@@ -825,22 +871,27 @@ delete() can now block. If this is a problem, there is a callback-based
mechanism that never blocks, namely call_rcu() or kfree_rcu(), that can mechanism that never blocks, namely call_rcu() or kfree_rcu(), that can
be used in place of synchronize_rcu(). be used in place of synchronize_rcu().
.. _7_whatisRCU:
7. FULL LIST OF RCU APIs 7. FULL LIST OF RCU APIs
-------------------------
The RCU APIs are documented in docbook-format header comments in the The RCU APIs are documented in docbook-format header comments in the
Linux-kernel source code, but it helps to have a full list of the Linux-kernel source code, but it helps to have a full list of the
APIs, since there does not appear to be a way to categorize them APIs, since there does not appear to be a way to categorize them
in docbook. Here is the list, by category. in docbook. Here is the list, by category.
RCU list traversal: RCU list traversal::
list_entry_rcu list_entry_rcu
list_entry_lockless
list_first_entry_rcu list_first_entry_rcu
list_next_rcu list_next_rcu
list_for_each_entry_rcu list_for_each_entry_rcu
list_for_each_entry_continue_rcu list_for_each_entry_continue_rcu
list_for_each_entry_from_rcu list_for_each_entry_from_rcu
list_first_or_null_rcu
list_next_or_null_rcu
hlist_first_rcu hlist_first_rcu
hlist_next_rcu hlist_next_rcu
hlist_pprev_rcu hlist_pprev_rcu
@@ -854,7 +905,7 @@ RCU list traversal:
hlist_bl_first_rcu hlist_bl_first_rcu
hlist_bl_for_each_entry_rcu hlist_bl_for_each_entry_rcu
RCU pointer/list update: RCU pointer/list update::
rcu_assign_pointer rcu_assign_pointer
list_add_rcu list_add_rcu
@@ -864,10 +915,12 @@ RCU pointer/list update:
hlist_add_behind_rcu hlist_add_behind_rcu
hlist_add_before_rcu hlist_add_before_rcu
hlist_add_head_rcu hlist_add_head_rcu
hlist_add_tail_rcu
hlist_del_rcu hlist_del_rcu
hlist_del_init_rcu hlist_del_init_rcu
hlist_replace_rcu hlist_replace_rcu
list_splice_init_rcu() list_splice_init_rcu
list_splice_tail_init_rcu
hlist_nulls_del_init_rcu hlist_nulls_del_init_rcu
hlist_nulls_del_rcu hlist_nulls_del_rcu
hlist_nulls_add_head_rcu hlist_nulls_add_head_rcu
@@ -876,7 +929,9 @@ RCU pointer/list update:
hlist_bl_del_rcu hlist_bl_del_rcu
hlist_bl_set_first_rcu hlist_bl_set_first_rcu
RCU: Critical sections Grace period Barrier RCU::
Critical sections Grace period Barrier
rcu_read_lock synchronize_net rcu_barrier rcu_read_lock synchronize_net rcu_barrier
rcu_read_unlock synchronize_rcu rcu_read_unlock synchronize_rcu
@@ -885,7 +940,9 @@ RCU: Critical sections Grace period Barrier
rcu_dereference_check kfree_rcu rcu_dereference_check kfree_rcu
rcu_dereference_protected rcu_dereference_protected
bh: Critical sections Grace period Barrier bh::
Critical sections Grace period Barrier
rcu_read_lock_bh call_rcu rcu_barrier rcu_read_lock_bh call_rcu rcu_barrier
rcu_read_unlock_bh synchronize_rcu rcu_read_unlock_bh synchronize_rcu
@@ -896,7 +953,9 @@ bh: Critical sections Grace period Barrier
rcu_dereference_bh_protected rcu_dereference_bh_protected
rcu_read_lock_bh_held rcu_read_lock_bh_held
sched: Critical sections Grace period Barrier sched::
Critical sections Grace period Barrier
rcu_read_lock_sched call_rcu rcu_barrier rcu_read_lock_sched call_rcu rcu_barrier
rcu_read_unlock_sched synchronize_rcu rcu_read_unlock_sched synchronize_rcu
@@ -910,7 +969,9 @@ sched: Critical sections Grace period Barrier
rcu_read_lock_sched_held rcu_read_lock_sched_held
SRCU: Critical sections Grace period Barrier SRCU::
Critical sections Grace period Barrier
srcu_read_lock call_srcu srcu_barrier srcu_read_lock call_srcu srcu_barrier
srcu_read_unlock synchronize_srcu srcu_read_unlock synchronize_srcu
@@ -918,13 +979,14 @@ SRCU: Critical sections Grace period Barrier
srcu_dereference_check srcu_dereference_check
srcu_read_lock_held srcu_read_lock_held
SRCU: Initialization/cleanup SRCU: Initialization/cleanup::
DEFINE_SRCU DEFINE_SRCU
DEFINE_STATIC_SRCU DEFINE_STATIC_SRCU
init_srcu_struct init_srcu_struct
cleanup_srcu_struct cleanup_srcu_struct
All: lockdep-checked RCU-protected pointer access All: lockdep-checked RCU-protected pointer access::
rcu_access_pointer rcu_access_pointer
rcu_dereference_raw rcu_dereference_raw
@@ -974,15 +1036,19 @@ g. Otherwise, use RCU.
Of course, this all assumes that you have determined that RCU is in fact Of course, this all assumes that you have determined that RCU is in fact
the right tool for your job. the right tool for your job.
.. _8_whatisRCU:
8. ANSWERS TO QUICK QUIZZES 8. ANSWERS TO QUICK QUIZZES
----------------------------
Quick Quiz #1: Why is this argument naive? How could a deadlock Quick Quiz #1:
Why is this argument naive? How could a deadlock
occur when using this algorithm in a real-world Linux occur when using this algorithm in a real-world Linux
kernel? [Referring to the lock-based "toy" RCU kernel? [Referring to the lock-based "toy" RCU
algorithm.] algorithm.]
Answer: Consider the following sequence of events: Answer:
Consider the following sequence of events:
1. CPU 0 acquires some unrelated lock, call it 1. CPU 0 acquires some unrelated lock, call it
"problematic_lock", disabling irq via "problematic_lock", disabling irq via
@@ -1021,10 +1087,14 @@ Answer: Consider the following sequence of events:
approach where tasks in RCU read-side critical sections approach where tasks in RCU read-side critical sections
cannot be blocked by tasks executing synchronize_rcu(). cannot be blocked by tasks executing synchronize_rcu().
Quick Quiz #2: Give an example where Classic RCU's read-side :ref:`Back to Quick Quiz #1 <quiz_1>`
overhead is -negative-.
Answer: Imagine a single-CPU system with a non-CONFIG_PREEMPT Quick Quiz #2:
Give an example where Classic RCU's read-side
overhead is **negative**.
Answer:
Imagine a single-CPU system with a non-CONFIG_PREEMPT
kernel where a routing table is used by process-context kernel where a routing table is used by process-context
code, but can be updated by irq-context code (for example, code, but can be updated by irq-context code (for example,
by an "ICMP REDIRECT" packet). The usual way of handling by an "ICMP REDIRECT" packet). The usual way of handling
@@ -1046,11 +1116,15 @@ Answer: Imagine a single-CPU system with a non-CONFIG_PREEMPT
even the theoretical possibility of negative overhead for even the theoretical possibility of negative overhead for
a synchronization primitive is a bit unexpected. ;-) a synchronization primitive is a bit unexpected. ;-)
Quick Quiz #3: If it is illegal to block in an RCU read-side :ref:`Back to Quick Quiz #2 <quiz_2>`
Quick Quiz #3:
If it is illegal to block in an RCU read-side
critical section, what the heck do you do in critical section, what the heck do you do in
PREEMPT_RT, where normal spinlocks can block??? PREEMPT_RT, where normal spinlocks can block???
Answer: Just as PREEMPT_RT permits preemption of spinlock Answer:
Just as PREEMPT_RT permits preemption of spinlock
critical sections, it permits preemption of RCU critical sections, it permits preemption of RCU
read-side critical sections. It also permits read-side critical sections. It also permits
spinlocks blocking while in RCU read-side critical spinlocks blocking while in RCU read-side critical
@@ -1069,6 +1143,7 @@ Answer: Just as PREEMPT_RT permits preemption of spinlock
Besides, how does the computer know what pizza parlor Besides, how does the computer know what pizza parlor
the human being went to??? the human being went to???
:ref:`Back to Quick Quiz #3 <quiz_3>`
ACKNOWLEDGEMENTS ACKNOWLEDGEMENTS

62
Documentation/admin-guide/acpi/fan_performance_states.rst Normal file
View File

@@ -0,0 +1,62 @@
.. SPDX-License-Identifier: GPL-2.0
===========================
ACPI Fan Performance States
===========================
When the optional _FPS object is present under an ACPI device representing a
fan (for example, PNP0C0B or INT3404), the ACPI fan driver creates additional
"state*" attributes in the sysfs directory of the ACPI device in question.
These attributes list properties of fan performance states.
For more information on _FPS refer to the ACPI specification at:
http://uefi.org/specifications
For instance, the contents of the INT3404 ACPI device sysfs directory
may look as follows::
$ ls -l /sys/bus/acpi/devices/INT3404:00/
total 0
...
-r--r--r-- 1 root root 4096 Dec 13 20:38 state0
-r--r--r-- 1 root root 4096 Dec 13 20:38 state1
-r--r--r-- 1 root root 4096 Dec 13 20:38 state10
-r--r--r-- 1 root root 4096 Dec 13 20:38 state11
-r--r--r-- 1 root root 4096 Dec 13 20:38 state2
-r--r--r-- 1 root root 4096 Dec 13 20:38 state3
-r--r--r-- 1 root root 4096 Dec 13 20:38 state4
-r--r--r-- 1 root root 4096 Dec 13 20:38 state5
-r--r--r-- 1 root root 4096 Dec 13 20:38 state6
-r--r--r-- 1 root root 4096 Dec 13 20:38 state7
-r--r--r-- 1 root root 4096 Dec 13 20:38 state8
-r--r--r-- 1 root root 4096 Dec 13 20:38 state9
-r--r--r-- 1 root root 4096 Dec 13 01:00 status
...
where each of the "state*" files represents one performance state of the fan
and contains a colon-separated list of 5 integer numbers (fields) with the
following interpretation::
control_percent:trip_point_index:speed_rpm:noise_level_mdb:power_mw
* ``control_percent``: The percent value to be used to set the fan speed to a
specific level using the _FSL object (0-100).
* ``trip_point_index``: The active cooling trip point number that corresponds
to this performance state (0-9).
* ``speed_rpm``: Speed of the fan in rotations per minute.
* ``noise_level_mdb``: Audible noise emitted by the fan in this state in
millidecibels.
* ``power_mw``: Power draw of the fan in this state in milliwatts.
For example::
$cat /sys/bus/acpi/devices/INT3404:00/state1
25:0:3200:12500:1250
When a given field is not populated or its value provided by the platform
firmware is invalid, the "not-defined" string is shown instead of the value.

1
Documentation/admin-guide/acpi/index.rst
View File

@@ -12,3 +12,4 @@ the Linux ACPI support.
dsdt-override dsdt-override
ssdt-overlays ssdt-overlays
cppc_sysfs cppc_sysfs
fan_performance_states

29
Documentation/admin-guide/cgroup-v2.rst
View File

@@ -61,6 +61,8 @@ v1 is available under Documentation/admin-guide/cgroup-v1/.
5-6. Device 5-6. Device
5-7. RDMA 5-7. RDMA
5-7-1. RDMA Interface Files 5-7-1. RDMA Interface Files
5-8. HugeTLB
5.8-1. HugeTLB Interface Files
5-8. Misc 5-8. Misc
5-8-1. perf_event 5-8-1. perf_event
5-N. Non-normative information 5-N. Non-normative information
@@ -2056,6 +2058,33 @@ RDMA Interface Files
mlx4_0 hca_handle=1 hca_object=20 mlx4_0 hca_handle=1 hca_object=20
ocrdma1 hca_handle=1 hca_object=23 ocrdma1 hca_handle=1 hca_object=23
HugeTLB
-------
The HugeTLB controller allows to limit the HugeTLB usage per control group and
enforces the controller limit during page fault.
HugeTLB Interface Files
~~~~~~~~~~~~~~~~~~~~~~~
hugetlb.<hugepagesize>.current
Show current usage for "hugepagesize" hugetlb. It exists for all
the cgroup except root.
hugetlb.<hugepagesize>.max
Set/show the hard limit of "hugepagesize" hugetlb usage.
The default value is "max". It exists for all the cgroup except root.
hugetlb.<hugepagesize>.events
A read-only flat-keyed file which exists on non-root cgroups.
max
The number of allocation failure due to HugeTLB limit
hugetlb.<hugepagesize>.events.local
Similar to hugetlb.<hugepagesize>.events but the fields in the file
are local to the cgroup i.e. not hierarchical. The file modified event
generated on this file reflects only the local events.
Misc Misc
---- ----

58
Documentation/admin-guide/kernel-parameters.txt
View File

@@ -511,7 +511,7 @@
1 -- check protection requested by application. 1 -- check protection requested by application.
Default value is set via a kernel config option. Default value is set via a kernel config option.
Value can be changed at runtime via Value can be changed at runtime via
/selinux/checkreqprot. /sys/fs/selinux/checkreqprot.
cio_ignore= [S390] cio_ignore= [S390]
See Documentation/s390/common_io.rst for details. See Documentation/s390/common_io.rst for details.
@@ -1165,10 +1165,10 @@
efi= [EFI] efi= [EFI]
Format: { "old_map", "nochunk", "noruntime", "debug", Format: { "old_map", "nochunk", "noruntime", "debug",
"nosoftreserve" } "nosoftreserve", "disable_early_pci_dma",
"no_disable_early_pci_dma" }
old_map [X86-64]: switch to the old ioremap-based EFI old_map [X86-64]: switch to the old ioremap-based EFI
runtime services mapping. 32-bit still uses this one by runtime services mapping. [Needs CONFIG_X86_UV=y]
default.
nochunk: disable reading files in "chunks" in the EFI nochunk: disable reading files in "chunks" in the EFI
boot stub, as chunking can cause problems with some boot stub, as chunking can cause problems with some
firmware implementations. firmware implementations.
@@ -1180,6 +1180,10 @@
claim. Specify efi=nosoftreserve to disable this claim. Specify efi=nosoftreserve to disable this
reservation and treat the memory by its base type reservation and treat the memory by its base type
(i.e. EFI_CONVENTIONAL_MEMORY / "System RAM"). (i.e. EFI_CONVENTIONAL_MEMORY / "System RAM").
disable_early_pci_dma: Disable the busmaster bit on all
PCI bridges while in the EFI boot stub
no_disable_early_pci_dma: Leave the busmaster bit set
on all PCI bridges while in the EFI boot stub
efi_no_storage_paranoia [EFI; X86] efi_no_storage_paranoia [EFI; X86]
Using this parameter you can use more than 50% of Using this parameter you can use more than 50% of
@@ -1245,7 +1249,8 @@
0 -- permissive (log only, no denials). 0 -- permissive (log only, no denials).
1 -- enforcing (deny and log). 1 -- enforcing (deny and log).
Default value is 0. Default value is 0.
Value can be changed at runtime via /selinux/enforce. Value can be changed at runtime via
/sys/fs/selinux/enforce.
erst_disable [ACPI] erst_disable [ACPI]
Disable Error Record Serialization Table (ERST) Disable Error Record Serialization Table (ERST)
@@ -1933,10 +1938,32 @@
<cpu number> begins at 0 and the maximum value is <cpu number> begins at 0 and the maximum value is
"number of CPUs in system - 1". "number of CPUs in system - 1".
managed_irq
Isolate from being targeted by managed interrupts
which have an interrupt mask containing isolated
CPUs. The affinity of managed interrupts is
handled by the kernel and cannot be changed via
the /proc/irq/* interfaces.
This isolation is best effort and only effective
if the automatically assigned interrupt mask of a
device queue contains isolated and housekeeping
CPUs. If housekeeping CPUs are online then such
interrupts are directed to the housekeeping CPU
so that IO submitted on the housekeeping CPU
cannot disturb the isolated CPU.
If a queue's affinity mask contains only isolated
CPUs then this parameter has no effect on the
interrupt routing decision, though interrupts are
only delivered when tasks running on those
isolated CPUs submit IO. IO submitted on
housekeeping CPUs has no influence on those
queues.
The format of <cpu-list> is described above. The format of <cpu-list> is described above.
iucv= [HW,NET] iucv= [HW,NET]
ivrs_ioapic [HW,X86_64] ivrs_ioapic [HW,X86_64]
@@ -3978,6 +4005,19 @@
test until boot completes in order to avoid test until boot completes in order to avoid
interference. interference.
rcuperf.kfree_rcu_test= [KNL]
Set to measure performance of kfree_rcu() flooding.
rcuperf.kfree_nthreads= [KNL]
The number of threads running loops of kfree_rcu().
rcuperf.kfree_alloc_num= [KNL]
Number of allocations and frees done in an iteration.
rcuperf.kfree_loops= [KNL]
Number of loops doing rcuperf.kfree_alloc_num number
of allocations and frees.
rcuperf.nreaders= [KNL] rcuperf.nreaders= [KNL]
Set number of RCU readers. The value -1 selects Set number of RCU readers. The value -1 selects
N, where N is the number of CPUs. A value N, where N is the number of CPUs. A value
@@ -4348,9 +4388,7 @@
See security/selinux/Kconfig help text. See security/selinux/Kconfig help text.
0 -- disable. 0 -- disable.
1 -- enable. 1 -- enable.
Default value is set via kernel config option. Default value is 1.
If enabled at boot time, /selinux/disable can be used
later to disable prior to initial policy load.
apparmor= [APPARMOR] Disable or enable AppArmor at boot time apparmor= [APPARMOR] Disable or enable AppArmor at boot time
Format: { "0" | "1" } Format: { "0" | "1" }

3
Documentation/admin-guide/pm/cpuidle.rst
View File

@@ -506,6 +506,9 @@ object corresponding to it, as follows:
``disable`` ``disable``
Whether or not this idle state is disabled. Whether or not this idle state is disabled.
``default_status``
The default status of this state, "enabled" or "disabled".
``latency`` ``latency``
Exit latency of the idle state in microseconds. Exit latency of the idle state in microseconds.

246
Documentation/admin-guide/pm/intel_idle.rst Normal file
View File

@@ -0,0 +1,246 @@
.. SPDX-License-Identifier: GPL-2.0
.. include:: <isonum.txt>
==============================================
``intel_idle`` CPU Idle Time Management Driver
==============================================
:Copyright: |copy| 2020 Intel Corporation
:Author: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
General Information
===================
``intel_idle`` is a part of the
:doc:`CPU idle time management subsystem <cpuidle>` in the Linux kernel
(``CPUIdle``). It is the default CPU idle time management driver for the
Nehalem and later generations of Intel processors, but the level of support for
a particular processor model in it depends on whether or not it recognizes that
processor model and may also depend on information coming from the platform
firmware. [To understand ``intel_idle`` it is necessary to know how ``CPUIdle``
works in general, so this is the time to get familiar with :doc:`cpuidle` if you
have not done that yet.]
``intel_idle`` uses the ``MWAIT`` instruction to inform the processor that the
logical CPU executing it is idle and so it may be possible to put some of the
processor's functional blocks into low-power states. That instruction takes two
arguments (passed in the ``EAX`` and ``ECX`` registers of the target CPU), the
first of which, referred to as a *hint*, can be used by the processor to
determine what can be done (for details refer to Intel Software Developer’s
Manual [1]_). Accordingly, ``intel_idle`` refuses to work with processors in
which the support for the ``MWAIT`` instruction has been disabled (for example,
via the platform firmware configuration menu) or which do not support that
instruction at all.
``intel_idle`` is not modular, so it cannot be unloaded, which means that the
only way to pass early-configuration-time parameters to it is via the kernel
command line.
.. _intel-idle-enumeration-of-states:
Enumeration of Idle States
==========================
Each ``MWAIT`` hint value is interpreted by the processor as a license to
reconfigure itself in a certain way in order to save energy. The processor
configurations (with reduced power draw) resulting from that are referred to
as C-states (in the ACPI terminology) or idle states. The list of meaningful
``MWAIT`` hint values and idle states (i.e. low-power configurations of the
processor) corresponding to them depends on the processor model and it may also
depend on the configuration of the platform.
In order to create a list of available idle states required by the ``CPUIdle``
subsystem (see :ref:`idle-states-representation` in :doc:`cpuidle`),
``intel_idle`` can use two sources of information: static tables of idle states
for different processor models included in the driver itself and the ACPI tables
of the system. The former are always used if the processor model at hand is
recognized by ``intel_idle`` and the latter are used if that is required for
the given processor model (which is the case for all server processor models
recognized by ``intel_idle``) or if the processor model is not recognized.
If the ACPI tables are going to be used for building the list of available idle
states, ``intel_idle`` first looks for a ``_CST`` object under one of the ACPI
objects corresponding to the CPUs in the system (refer to the ACPI specification
[2]_ for the description of ``_CST`` and its output package). Because the
``CPUIdle`` subsystem expects that the list of idle states supplied by the
driver will be suitable for all of the CPUs handled by it and ``intel_idle`` is
registered as the ``CPUIdle`` driver for all of the CPUs in the system, the
driver looks for the first ``_CST`` object returning at least one valid idle
state description and such that all of the idle states included in its return
package are of the FFH (Functional Fixed Hardware) type, which means that the
``MWAIT`` instruction is expected to be used to tell the processor that it can
enter one of them. The return package of that ``_CST`` is then assumed to be
applicable to all of the other CPUs in the system and the idle state
descriptions extracted from it are stored in a preliminary list of idle states
coming from the ACPI tables. [This step is skipped if ``intel_idle`` is
configured to ignore the ACPI tables; see `below <intel-idle-parameters_>`_.]
Next, the first (index 0) entry in the list of available idle states is
initialized to represent a "polling idle state" (a pseudo-idle state in which
the target CPU continuously fetches and executes instructions), and the
subsequent (real) idle state entries are populated as follows.
If the processor model at hand is recognized by ``intel_idle``, there is a
(static) table of idle state descriptions for it in the driver. In that case,
the "internal" table is the primary source of information on idle states and the
information from it is copied to the final list of available idle states. If
using the ACPI tables for the enumeration of idle states is not required
(depending on the processor model), all of the listed idle state are enabled by
default (so all of them will be taken into consideration by ``CPUIdle``
governors during CPU idle state selection). Otherwise, some of the listed idle
states may not be enabled by default if there are no matching entries in the
preliminary list of idle states coming from the ACPI tables. In that case user
space still can enable them later (on a per-CPU basis) with the help of
the ``disable`` idle state attribute in ``sysfs`` (see
:ref:`idle-states-representation` in :doc:`cpuidle`). This basically means that
the idle states "known" to the driver may not be enabled by default if they have
not been exposed by the platform firmware (through the ACPI tables).
If the given processor model is not recognized by ``intel_idle``, but it
supports ``MWAIT``, the preliminary list of idle states coming from the ACPI
tables is used for building the final list that will be supplied to the
``CPUIdle`` core during driver registration. For each idle state in that list,
the description, ``MWAIT`` hint and exit latency are copied to the corresponding
entry in the final list of idle states. The name of the idle state represented
by it (to be returned by the ``name`` idle state attribute in ``sysfs``) is
"CX_ACPI", where X is the index of that idle state in the final list (note that
the minimum value of X is 1, because 0 is reserved for the "polling" state), and
its target residency is based on the exit latency value. Specifically, for
C1-type idle states the exit latency value is also used as the target residency
(for compatibility with the majority of the "internal" tables of idle states for
various processor models recognized by ``intel_idle``) and for the other idle
state types (C2 and C3) the target residency value is 3 times the exit latency
(again, that is because it reflects the target residency to exit latency ratio
in the majority of cases for the processor models recognized by ``intel_idle``).
All of the idle states in the final list are enabled by default in this case.
.. _intel-idle-initialization:
Initialization
==============
The initialization of ``intel_idle`` starts with checking if the kernel command
line options forbid the use of the ``MWAIT`` instruction. If that is the case,
an error code is returned right away.
The next step is to check whether or not the processor model is known to the
driver, which determines the idle states enumeration method (see
`above <intel-idle-enumeration-of-states_>`_), and whether or not the processor
supports ``MWAIT`` (the initialization fails if that is not the case). Then,
the ``MWAIT`` support in the processor is enumerated through ``CPUID`` and the
driver initialization fails if the level of support is not as expected (for
example, if the total number of ``MWAIT`` substates returned is 0).
Next, if the driver is not configured to ignore the ACPI tables (see
`below <intel-idle-parameters_>`_), the idle states information provided by the
platform firmware is extracted from them.
Then, ``CPUIdle`` device objects are allocated for all CPUs and the list of
available idle states is created as explained
`above <intel-idle-enumeration-of-states_>`_.
Finally, ``intel_idle`` is registered with the help of cpuidle_register_driver()
as the ``CPUIdle`` driver for all CPUs in the system and a CPU online callback
for configuring individual CPUs is registered via cpuhp_setup_state(), which
(among other things) causes the callback routine to be invoked for all of the
CPUs present in the system at that time (each CPU executes its own instance of
the callback routine). That routine registers a ``CPUIdle`` device for the CPU
running it (which enables the ``CPUIdle`` subsystem to operate that CPU) and
optionally performs some CPU-specific initialization actions that may be
required for the given processor model.
.. _intel-idle-parameters:
Kernel Command Line Options and Module Parameters
=================================================
The *x86* architecture support code recognizes three kernel command line
options related to CPU idle time management: ``idle=poll``, ``idle=halt``,
and ``idle=nomwait``. If any of them is present in the kernel command line, the
``MWAIT`` instruction is not allowed to be used, so the initialization of
``intel_idle`` will fail.
Apart from that there are two module parameters recognized by ``intel_idle``
itself that can be set via the kernel command line (they cannot be updated via
sysfs, so that is the only way to change their values).
The ``max_cstate`` parameter value is the maximum idle state index in the list
of idle states supplied to the ``CPUIdle`` core during the registration of the
driver. It is also the maximum number of regular (non-polling) idle states that
can be used by ``intel_idle``, so the enumeration of idle states is terminated
after finding that number of usable idle states (the other idle states that
potentially might have been used if ``max_cstate`` had been greater are not
taken into consideration at all). Setting ``max_cstate`` can prevent
``intel_idle`` from exposing idle states that are regarded as "too deep" for
some reason to the ``CPUIdle`` core, but it does so by making them effectively
invisible until the system is shut down and started again which may not always
be desirable. In practice, it is only really necessary to do that if the idle
states in question cannot be enabled during system startup, because in the
working state of the system the CPU power management quality of service (PM
QoS) feature can be used to prevent ``CPUIdle`` from touching those idle states
even if they have been enumerated (see :ref:`cpu-pm-qos` in :doc:`cpuidle`).
Setting ``max_cstate`` to 0 causes the ``intel_idle`` initialization to fail.
The ``noacpi`` module parameter (which is recognized by ``intel_idle`` if the
kernel has been configured with ACPI support), can be set to make the driver
ignore the system's ACPI tables entirely (it is unset by default).
.. _intel-idle-core-and-package-idle-states:
Core and Package Levels of Idle States
======================================
Typically, in a processor supporting the ``MWAIT`` instruction there are (at
least) two levels of idle states (or C-states). One level, referred to as
"core C-states", covers individual cores in the processor, whereas the other
level, referred to as "package C-states", covers the entire processor package
and it may also involve other components of the system (GPUs, memory
controllers, I/O hubs etc.).
Some of the ``MWAIT`` hint values allow the processor to use core C-states only
(most importantly, that is the case for the ``MWAIT`` hint value corresponding
to the ``C1`` idle state), but the majority of them give it a license to put
the target core (i.e. the core containing the logical CPU executing ``MWAIT``
with the given hint value) into a specific core C-state and then (if possible)
to enter a specific package C-state at the deeper level. For example, the
``MWAIT`` hint value representing the ``C3`` idle state allows the processor to
put the target core into the low-power state referred to as "core ``C3``" (or
``CC3``), which happens if all of the logical CPUs (SMT siblings) in that core
have executed ``MWAIT`` with the ``C3`` hint value (or with a hint value
representing a deeper idle state), and in addition to that (in the majority of
cases) it gives the processor a license to put the entire package (possibly
including some non-CPU components such as a GPU or a memory controller) into the
low-power state referred to as "package ``C3``" (or ``PC3``), which happens if
all of the cores have gone into the ``CC3`` state and (possibly) some additional
conditions are satisfied (for instance, if the GPU is covered by ``PC3``, it may
be required to be in a certain GPU-specific low-power state for ``PC3`` to be
reachable).
As a rule, there is no simple way to make the processor use core C-states only
if the conditions for entering the corresponding package C-states are met, so
the logical CPU executing ``MWAIT`` with a hint value that is not core-level
only (like for ``C1``) must always assume that this may cause the processor to
enter a package C-state. [That is why the exit latency and target residency
values corresponding to the majority of ``MWAIT`` hint values in the "internal"
tables of idle states in ``intel_idle`` reflect the properties of package
C-states.] If using package C-states is not desirable at all, either
:ref:`PM QoS <cpu-pm-qos>` or the ``max_cstate`` module parameter of
``intel_idle`` described `above <intel-idle-parameters_>`_ must be used to
restrict the range of permissible idle states to the ones with core-level only
``MWAIT`` hint values (like ``C1``).
References
==========
.. [1] *Intel® 64 and IA-32 Architectures Software Developer’s Manual Volume 2B*,
https://www.intel.com/content/www/us/en/architecture-and-technology/64-ia-32-architectures-software-developer-vol-2b-manual.html
.. [2] *Advanced Configuration and Power Interface (ACPI) Specification*,
https://uefi.org/specifications

1
Documentation/admin-guide/pm/working-state.rst
View File

@@ -8,6 +8,7 @@ Working-State Power Management
:maxdepth: 2 :maxdepth: 2
cpuidle cpuidle
intel_idle
cpufreq cpufreq
intel_pstate intel_pstate
intel_epb intel_epb

16
Documentation/arm64/cpu-feature-registers.rst
View File

@@ -117,6 +117,8 @@ infrastructure:
+------------------------------+---------+---------+ +------------------------------+---------+---------+
| Name | bits | visible | | Name | bits | visible |
+------------------------------+---------+---------+ +------------------------------+---------+---------+
| RNDR | [63-60] | y |
+------------------------------+---------+---------+
| TS | [55-52] | y | | TS | [55-52] | y |
+------------------------------+---------+---------+ +------------------------------+---------+---------+
| FHM | [51-48] | y | | FHM | [51-48] | y |
@@ -200,6 +202,12 @@ infrastructure:
+------------------------------+---------+---------+ +------------------------------+---------+---------+
| Name | bits | visible | | Name | bits | visible |
+------------------------------+---------+---------+ +------------------------------+---------+---------+
| I8MM | [55-52] | y |
+------------------------------+---------+---------+
| DGH | [51-48] | y |
+------------------------------+---------+---------+
| BF16 | [47-44] | y |
+------------------------------+---------+---------+
| SB | [39-36] | y | | SB | [39-36] | y |
+------------------------------+---------+---------+ +------------------------------+---------+---------+
| FRINTTS | [35-32] | y | | FRINTTS | [35-32] | y |
@@ -234,10 +242,18 @@ infrastructure:
+------------------------------+---------+---------+ +------------------------------+---------+---------+
| Name | bits | visible | | Name | bits | visible |
+------------------------------+---------+---------+ +------------------------------+---------+---------+
| F64MM | [59-56] | y |
+------------------------------+---------+---------+
| F32MM | [55-52] | y |
+------------------------------+---------+---------+
| I8MM | [47-44] | y |
+------------------------------+---------+---------+
| SM4 | [43-40] | y | | SM4 | [43-40] | y |
+------------------------------+---------+---------+ +------------------------------+---------+---------+
| SHA3 | [35-32] | y | | SHA3 | [35-32] | y |
+------------------------------+---------+---------+ +------------------------------+---------+---------+
| BF16 | [23-20] | y |
+------------------------------+---------+---------+
| BitPerm | [19-16] | y | | BitPerm | [19-16] | y |
+------------------------------+---------+---------+ +------------------------------+---------+---------+
| AES | [7-4] | y | | AES | [7-4] | y |

31
Documentation/arm64/elf_hwcaps.rst
View File

@@ -204,6 +204,37 @@ HWCAP2_FRINT
Functionality implied by ID_AA64ISAR1_EL1.FRINTTS == 0b0001. Functionality implied by ID_AA64ISAR1_EL1.FRINTTS == 0b0001.
HWCAP2_SVEI8MM
Functionality implied by ID_AA64ZFR0_EL1.I8MM == 0b0001.
HWCAP2_SVEF32MM
Functionality implied by ID_AA64ZFR0_EL1.F32MM == 0b0001.
HWCAP2_SVEF64MM
Functionality implied by ID_AA64ZFR0_EL1.F64MM == 0b0001.
HWCAP2_SVEBF16
Functionality implied by ID_AA64ZFR0_EL1.BF16 == 0b0001.
HWCAP2_I8MM
Functionality implied by ID_AA64ISAR1_EL1.I8MM == 0b0001.
HWCAP2_BF16
Functionality implied by ID_AA64ISAR1_EL1.BF16 == 0b0001.
HWCAP2_DGH
Functionality implied by ID_AA64ISAR1_EL1.DGH == 0b0001.
HWCAP2_RNG
Functionality implied by ID_AA64ISAR0_EL1.RNDR == 0b0001.
4. Unused AT_HWCAP bits 4. Unused AT_HWCAP bits
----------------------- -----------------------

2
Documentation/arm64/silicon-errata.rst
View File

@@ -88,6 +88,8 @@ stable kernels.
+----------------+-----------------+-----------------+-----------------------------+ +----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A76 | #1463225 | ARM64_ERRATUM_1463225 | | ARM | Cortex-A76 | #1463225 | ARM64_ERRATUM_1463225 |
+----------------+-----------------+-----------------+-----------------------------+ +----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A55 | #1530923 | ARM64_ERRATUM_1530923 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-N1 | #1188873,1418040| ARM64_ERRATUM_1418040 | | ARM | Neoverse-N1 | #1188873,1418040| ARM64_ERRATUM_1418040 |
+----------------+-----------------+-----------------+-----------------------------+ +----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-N1 | #1349291 | N/A | | ARM | Neoverse-N1 | #1349291 | N/A |

6
Documentation/devicetree/bindings/arm/atmel-sysregs.txt
View File

@@ -10,6 +10,12 @@ PIT Timer required properties:
- interrupts: Should contain interrupt for the PIT which is the IRQ line - interrupts: Should contain interrupt for the PIT which is the IRQ line
shared across all System Controller members. shared across all System Controller members.
PIT64B Timer required properties:
- compatible: Should be "microchip,sam9x60-pit64b"
- reg: Should contain registers location and length
- interrupts: Should contain interrupt for PIT64B timer
- clocks: Should contain the available clock sources for PIT64B timer.
System Timer (ST) required properties: System Timer (ST) required properties:
- compatible: Should be "atmel,at91rm9200-st", "syscon", "simple-mfd" - compatible: Should be "atmel,at91rm9200-st", "syscon", "simple-mfd"
- reg: Should contain registers location and length - reg: Should contain registers location and length

7
Documentation/devicetree/bindings/ata/brcm,sata-brcm.txt
View File

@@ -5,6 +5,7 @@ Each SATA controller should have its own node.
Required properties: Required properties:
- compatible : should be one or more of - compatible : should be one or more of
"brcm,bcm7216-ahci"
"brcm,bcm7425-ahci" "brcm,bcm7425-ahci"
"brcm,bcm7445-ahci" "brcm,bcm7445-ahci"
"brcm,bcm-nsp-ahci" "brcm,bcm-nsp-ahci"
@@ -14,6 +15,12 @@ Required properties:
- reg-names : "ahci" and "top-ctrl" - reg-names : "ahci" and "top-ctrl"
- interrupts : interrupt mapping for SATA IRQ - interrupts : interrupt mapping for SATA IRQ
Optional properties:
- reset: for "brcm,bcm7216-ahci" must be a valid reset phandle
pointing to the RESCAL reset controller provider node.
- reset-names: for "brcm,bcm7216-ahci", must be "rescal".
Also see ahci-platform.txt. Also see ahci-platform.txt.
Example: Example:

1
Documentation/devicetree/bindings/dma/fsl-edma.txt
View File

@@ -10,6 +10,7 @@ Required properties:
- compatible : - compatible :
- "fsl,vf610-edma" for eDMA used similar to that on Vybrid vf610 SoC - "fsl,vf610-edma" for eDMA used similar to that on Vybrid vf610 SoC
- "fsl,imx7ulp-edma" for eDMA2 used similar to that on i.mx7ulp - "fsl,imx7ulp-edma" for eDMA2 used similar to that on i.mx7ulp
- "fsl,fsl,ls1028a-edma" for eDMA used similar to that on Vybrid vf610 SoC
- reg : Specifies base physical address(s) and size of the eDMA registers. - reg : Specifies base physical address(s) and size of the eDMA registers.
The 1st region is eDMA control register's address and size. The 1st region is eDMA control register's address and size.
The 2nd and the 3rd regions are programmable channel multiplexing The 2nd and the 3rd regions are programmable channel multiplexing

3
Documentation/devicetree/bindings/dma/fsl-imx-sdma.txt
View File

@@ -10,6 +10,9 @@ Required properties:
"fsl,imx6q-sdma" "fsl,imx6q-sdma"
"fsl,imx7d-sdma" "fsl,imx7d-sdma"
"fsl,imx8mq-sdma" "fsl,imx8mq-sdma"
"fsl,imx8mm-sdma"
"fsl,imx8mn-sdma"
"fsl,imx8mp-sdma"
The -to variants should be preferred since they allow to determine the The -to variants should be preferred since they allow to determine the
correct ROM script addresses needed for the driver to work without additional correct ROM script addresses needed for the driver to work without additional
firmware. firmware.

6
Documentation/devicetree/bindings/dma/jz4780-dma.txt
View File

@@ -1,4 +1,4 @@
* Ingenic JZ4780 DMA Controller * Ingenic XBurst DMA Controller
Required properties: Required properties:
@@ -8,10 +8,12 @@ Required properties:
* ingenic,jz4770-dma * ingenic,jz4770-dma
* ingenic,jz4780-dma * ingenic,jz4780-dma
* ingenic,x1000-dma * ingenic,x1000-dma
* ingenic,x1830-dma
- reg: Should contain the DMA channel registers location and length, followed - reg: Should contain the DMA channel registers location and length, followed
by the DMA controller registers location and length. by the DMA controller registers location and length.
- interrupts: Should contain the interrupt specifier of the DMA controller. - interrupts: Should contain the interrupt specifier of the DMA controller.
- clocks: Should contain a clock specifier for the JZ4780/X1000 PDMA clock. - clocks: Should contain a clock specifier for the JZ4780/X1000/X1830 PDMA
clock.
- #dma-cells: Must be <2>. Number of integer cells in the dmas property of - #dma-cells: Must be <2>. Number of integer cells in the dmas property of
DMA clients (see below). DMA clients (see below).

1
Documentation/devicetree/bindings/dma/renesas,rcar-dmac.txt
View File

@@ -30,6 +30,7 @@ Required Properties:
- "renesas,dmac-r8a7794" (R-Car E2) - "renesas,dmac-r8a7794" (R-Car E2)
- "renesas,dmac-r8a7795" (R-Car H3) - "renesas,dmac-r8a7795" (R-Car H3)
- "renesas,dmac-r8a7796" (R-Car M3-W) - "renesas,dmac-r8a7796" (R-Car M3-W)
- "renesas,dmac-r8a77961" (R-Car M3-W+)
- "renesas,dmac-r8a77965" (R-Car M3-N) - "renesas,dmac-r8a77965" (R-Car M3-N)
- "renesas,dmac-r8a77970" (R-Car V3M) - "renesas,dmac-r8a77970" (R-Car V3M)
- "renesas,dmac-r8a77980" (R-Car V3H) - "renesas,dmac-r8a77980" (R-Car V3H)

184
Documentation/devicetree/bindings/dma/ti/k3-udma.yaml Normal file
View File

@@ -0,0 +1,184 @@
# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/dma/ti/k3-udma.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Texas Instruments K3 NAVSS Unified DMA Device Tree Bindings
maintainers:
- Peter Ujfalusi <peter.ujfalusi@ti.com>
description: |
The UDMA-P is intended to perform similar (but significantly upgraded)
functions as the packet-oriented DMA used on previous SoC devices. The UDMA-P
module supports the transmission and reception of various packet types.
The UDMA-P architecture facilitates the segmentation and reassembly of SoC DMA
data structure compliant packets to/from smaller data blocks that are natively
compatible with the specific requirements of each connected peripheral.
Multiple Tx and Rx channels are provided within the DMA which allow multiple
segmentation or reassembly operations to be ongoing. The DMA controller
maintains state information for each of the channels which allows packet
segmentation and reassembly operations to be time division multiplexed between
channels in order to share the underlying DMA hardware. An external DMA
scheduler is used to control the ordering and rate at which this multiplexing
occurs for Transmit operations. The ordering and rate of Receive operations
is indirectly controlled by the order in which blocks are pushed into the DMA
on the Rx PSI-L interface.
The UDMA-P also supports acting as both a UTC and UDMA-C for its internal
channels. Channels in the UDMA-P can be configured to be either Packet-Based
or Third-Party channels on a channel by channel basis.
All transfers within NAVSS is done between PSI-L source and destination
threads.
The peripherals serviced by UDMA can be PSI-L native (sa2ul, cpsw, etc) or
legacy, non PSI-L native peripherals. In the later case a special, small PDMA
is tasked to act as a bridge between the PSI-L fabric and the legacy
peripheral.
PDMAs can be configured via UDMAP peer registers to match with the
configuration of the legacy peripheral.
allOf:
- $ref: "../dma-controller.yaml#"
properties:
"#dma-cells":
const: 1
description: |
The cell is the PSI-L thread ID of the remote (to UDMAP) end.
Valid ranges for thread ID depends on the data movement direction:
for source thread IDs (rx): 0 - 0x7fff
for destination thread IDs (tx): 0x8000 - 0xffff
Please refer to the device documentation for the PSI-L thread map and also
the PSI-L peripheral chapter for the correct thread ID.
compatible:
enum:
- ti,am654-navss-main-udmap
- ti,am654-navss-mcu-udmap
- ti,j721e-navss-main-udmap
- ti,j721e-navss-mcu-udmap
reg:
maxItems: 3
reg-names:
items:
- const: gcfg
- const: rchanrt
- const: tchanrt
msi-parent: true
ti,sci:
description: phandle to TI-SCI compatible System controller node
allOf:
- $ref: /schemas/types.yaml#/definitions/phandle
ti,sci-dev-id:
description: TI-SCI device id of UDMAP
allOf:
- $ref: /schemas/types.yaml#/definitions/uint32
ti,ringacc:
description: phandle to the ring accelerator node
allOf:
- $ref: /schemas/types.yaml#/definitions/phandle
ti,sci-rm-range-tchan:
description: |
Array of UDMA tchan resource subtypes for resource allocation for this
host
allOf:
- $ref: /schemas/types.yaml#/definitions/uint32-array
minItems: 1
# Should be enough
maxItems: 255
ti,sci-rm-range-rchan:
description: |
Array of UDMA rchan resource subtypes for resource allocation for this
host
allOf:
- $ref: /schemas/types.yaml#/definitions/uint32-array
minItems: 1
# Should be enough
maxItems: 255
ti,sci-rm-range-rflow:
description: |
Array of UDMA rflow resource subtypes for resource allocation for this
host
allOf:
- $ref: /schemas/types.yaml#/definitions/uint32-array
minItems: 1
# Should be enough
maxItems: 255
required:
- compatible
- "#dma-cells"
- reg
- reg-names
- msi-parent
- ti,sci
- ti,sci-dev-id
- ti,ringacc
- ti,sci-rm-range-tchan
- ti,sci-rm-range-rchan
- ti,sci-rm-range-rflow
examples:
- |+
cbass_main {
#address-cells = <2>;
#size-cells = <2>;
cbass_main_navss: navss@30800000 {
compatible = "simple-mfd";
#address-cells = <2>;
#size-cells = <2>;
dma-coherent;
dma-ranges;
ranges;
ti,sci-dev-id = <118>;
main_udmap: dma-controller@31150000 {
compatible = "ti,am654-navss-main-udmap";
reg = <0x0 0x31150000 0x0 0x100>,
<0x0 0x34000000 0x0 0x100000>,
<0x0 0x35000000 0x0 0x100000>;
reg-names = "gcfg", "rchanrt", "tchanrt";
#dma-cells = <1>;
ti,ringacc = <&ringacc>;
msi-parent = <&inta_main_udmass>;
ti,sci = <&dmsc>;
ti,sci-dev-id = <188>;
ti,sci-rm-range-tchan = <0x1>, /* TX_HCHAN */
<0x2>; /* TX_CHAN */
ti,sci-rm-range-rchan = <0x4>, /* RX_HCHAN */
<0x5>; /* RX_CHAN */
ti,sci-rm-range-rflow = <0x6>; /* GP RFLOW */
};
};
mcasp0: mcasp@02B00000 {
dmas = <&main_udmap 0xc400>, <&main_udmap 0x4400>;
dma-names = "tx", "rx";
};
crypto: crypto@4E00000 {
compatible = "ti,sa2ul-crypto";
dmas = <&main_udmap 0xc000>, <&main_udmap 0x4000>, <&main_udmap 0x4001>;
dma-names = "tx", "rx1", "rx2";
};
};

68
Documentation/devicetree/bindings/gpio/sifive,gpio.yaml Normal file
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@@ -0,0 +1,68 @@
# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/gpio/sifive,gpio.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: SiFive GPIO controller
maintainers:
- Yash Shah <yash.shah@sifive.com>
- Paul Walmsley <paul.walmsley@sifive.com>
properties:
compatible:
items:
- const: sifive,fu540-c000-gpio
- const: sifive,gpio0
reg:
maxItems: 1
interrupts:
description:
interrupt mapping one per GPIO. Maximum 16 GPIOs.
minItems: 1
maxItems: 16
interrupt-controller: true
"#interrupt-cells":
const: 2
clocks:
maxItems: 1
"#gpio-cells":
const: 2
gpio-controller: true
required:
- compatible
- reg
- interrupts
- interrupt-controller
- "#interrupt-cells"
- clocks
- "#gpio-cells"
- gpio-controller
additionalProperties: false
examples:
- |
#include <dt-bindings/clock/sifive-fu540-prci.h>
gpio@10060000 {
compatible = "sifive,fu540-c000-gpio", "sifive,gpio0";
interrupt-parent = <&plic>;
interrupts = <7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22>;
reg = <0x0 0x10060000 0x0 0x1000>;
clocks = <&tlclk PRCI_CLK_TLCLK>;
gpio-controller;
#gpio-cells = <2>;
interrupt-controller;
#interrupt-cells = <2>;
};
...

66
Documentation/devicetree/bindings/hwmon/adi,adm1177.yaml Normal file
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@@ -0,0 +1,66 @@
# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/hwmon/adi,adm1177.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Analog Devices ADM1177 Hot Swap Controller and Digital Power Monitor
maintainers:
- Michael Hennerich <michael.hennerich@analog.com>
- Beniamin Bia <beniamin.bia@analog.com>
description: |
Analog Devices ADM1177 Hot Swap Controller and Digital Power Monitor
https://www.analog.com/media/en/technical-documentation/data-sheets/ADM1177.pdf
properties:
compatible:
enum:
- adi,adm1177
reg:
maxItems: 1
avcc-supply:
description:
Phandle to the Avcc power supply
shunt-resistor-micro-ohms:
description:
The value of curent sense resistor in microohms. If not provided,
the current reading and overcurrent alert is disabled.
adi,shutdown-threshold-microamp:
description:
Specifies the current level at which an over current alert occurs.
If not provided, the overcurrent alert is configured to max ADC range
based on shunt-resistor-micro-ohms.
adi,vrange-high-enable:
description:
Specifies which internal voltage divider to be used. A 1 selects
a 7:2 voltage divider while a 0 selects a 14:1 voltage divider.
type: boolean
required:
- compatible
- reg
examples:
- |
#include <dt-bindings/gpio/gpio.h>
#include <dt-bindings/interrupt-controller/irq.h>
i2c0 {
#address-cells = <1>;
#size-cells = <0>;
pwmon@5a {
compatible = "adi,adm1177";
reg = <0x5a>;
shunt-resistor-micro-ohms = <50000>; /* 50 mOhm */
adi,shutdown-threshold-microamp = <1059000>; /* 1.059 A */
adi,vrange-high-enable;
};
};
...

45
Documentation/devicetree/bindings/hwmon/pmbus/ti,ucd90320.yaml Normal file
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@@ -0,0 +1,45 @@
# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/hwmon/pmbus/ti,ucd90320.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: UCD90320 power sequencer
maintainers:
- Jim Wright <wrightj@linux.vnet.ibm.com>
description: |
The UCD90320 is a 32-rail PMBus/I2C addressable power-supply sequencer and
monitor. The 24 integrated ADC channels (AMONx) monitor the power supply
voltage, current, and temperature. Of the 84 GPIO pins, 8 can be used as
digital monitors (DMONx), 32 to enable the power supply (ENx), 24 for
margining (MARx), 16 for logical GPO, and 32 GPIs for cascading, and system
function.
http://focus.ti.com/lit/ds/symlink/ucd90320.pdf
properties:
compatible:
enum:
- ti,ucd90320
reg:
maxItems: 1
required:
- compatible
- reg
examples:
- |
i2c {
#address-cells = <1>;
#size-cells = <0>;
ucd90320@11 {
compatible = "ti,ucd90320";
reg = <0x11>;
};
};

1
Documentation/devicetree/bindings/interrupt-controller/amlogic,meson-gpio-intc.txt
View File

@@ -17,6 +17,7 @@ Required properties:
"amlogic,meson-axg-gpio-intc" for AXG SoCs (A113D, A113X) "amlogic,meson-axg-gpio-intc" for AXG SoCs (A113D, A113X)
"amlogic,meson-g12a-gpio-intc" for G12A SoCs (S905D2, S905X2, S905Y2) "amlogic,meson-g12a-gpio-intc" for G12A SoCs (S905D2, S905X2, S905Y2)
"amlogic,meson-sm1-gpio-intc" for SM1 SoCs (S905D3, S905X3, S905Y3) "amlogic,meson-sm1-gpio-intc" for SM1 SoCs (S905D3, S905X3, S905Y3)
"amlogic,meson-a1-gpio-intc" for A1 SoCs (A113L)
- reg : Specifies base physical address and size of the registers. - reg : Specifies base physical address and size of the registers.
- interrupt-controller : Identifies the node as an interrupt controller. - interrupt-controller : Identifies the node as an interrupt controller.
- #interrupt-cells : Specifies the number of cells needed to encode an - #interrupt-cells : Specifies the number of cells needed to encode an

23
Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2xxx-scu-ic.txt Normal file
View File

@@ -0,0 +1,23 @@
Aspeed AST25XX and AST26XX SCU Interrupt Controller
Required Properties:
- #interrupt-cells : must be 1
- compatible : must be "aspeed,ast2500-scu-ic",
"aspeed,ast2600-scu-ic0" or
"aspeed,ast2600-scu-ic1"
- interrupts : interrupt from the parent controller
- interrupt-controller : indicates that the controller receives and
fires new interrupts for child busses
Example:
syscon@1e6e2000 {
ranges = <0 0x1e6e2000 0x1a8>;
scu_ic: interrupt-controller@18 {
#interrupt-cells = <1>;
compatible = "aspeed,ast2500-scu-ic";
interrupts = <21>;
interrupt-controller;
};
};

68
Documentation/devicetree/bindings/interrupt-controller/fsl,intmux.yaml Normal file
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@@ -0,0 +1,68 @@
# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/interrupt-controller/fsl,intmux.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Freescale INTMUX interrupt multiplexer
maintainers:
- Joakim Zhang <qiangqing.zhang@nxp.com>
properties:
compatible:
const: fsl,imx-intmux
reg:
maxItems: 1
interrupts:
minItems: 1
maxItems: 8
description: |
Should contain the parent interrupt lines (up to 8) used to multiplex
the input interrupts.
interrupt-controller: true
'#interrupt-cells':
const: 2
description: |
The 1st cell is hw interrupt number, the 2nd cell is channel index.
clocks:
description: ipg clock.
clock-names:
const: ipg
required:
- compatible
- reg
- interrupts
- interrupt-controller
- '#interrupt-cells'
- clocks
- clock-names
additionalProperties: false
examples:
- |
interrupt-controller@37400000 {
compatible = "fsl,imx-intmux";
reg = <0x37400000 0x1000>;
interrupts = <0 16 4>,
<0 17 4>,
<0 18 4>,
<0 19 4>,
<0 20 4>,
<0 21 4>,
<0 22 4>,
<0 23 4>;
interrupt-controller;
interrupt-parent = <&gic>;
#interrupt-cells = <2>;
clocks = <&clk>;
clock-names = "ipg";
};

72
Documentation/devicetree/bindings/memory-controllers/fsl/imx8m-ddrc.yaml Normal file
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@@ -0,0 +1,72 @@
# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/memory-controllers/fsl/imx8m-ddrc.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: i.MX8M DDR Controller
maintainers:
- Leonard Crestez <leonard.crestez@nxp.com>
description:
The DDRC block is integrated in i.MX8M for interfacing with DDR based
memories.
It supports switching between different frequencies at runtime but during
this process RAM itself becomes briefly inaccessible so actual frequency
switching is implemented by TF-A code which runs from a SRAM area.
The Linux driver for the DDRC doesn't even map registers (they're included
for the sake of "describing hardware"), it mostly just exposes firmware
capabilities through standard Linux mechanism like devfreq and OPP tables.
properties:
compatible:
items:
- enum:
- fsl,imx8mn-ddrc
- fsl,imx8mm-ddrc
- fsl,imx8mq-ddrc
- const: fsl,imx8m-ddrc
reg:
maxItems: 1
description:
Base address and size of DDRC CTL area.
This is not currently mapped by the imx8m-ddrc driver.
clocks:
maxItems: 4
clock-names:
items:
- const: core
- const: pll
- const: alt
- const: apb
operating-points-v2: true
opp-table: true
required:
- reg
- compatible
- clocks
- clock-names
additionalProperties: false
examples:
- |
#include <dt-bindings/clock/imx8mm-clock.h>
ddrc: memory-controller@3d400000 {
compatible = "fsl,imx8mm-ddrc", "fsl,imx8m-ddrc";
reg = <0x3d400000 0x400000>;
clock-names = "core", "pll", "alt", "apb";
clocks = <&clk IMX8MM_CLK_DRAM_CORE>,
<&clk IMX8MM_DRAM_PLL>,
<&clk IMX8MM_CLK_DRAM_ALT>,
<&clk IMX8MM_CLK_DRAM_APB>;
operating-points-v2 = <&ddrc_opp_table>;
};

41
Documentation/devicetree/bindings/mmc/brcm,sdhci-brcmstb.txt
View File

@@ -11,28 +11,43 @@ Required properties:
- compatible: should be one of the following - compatible: should be one of the following
- "brcm,bcm7425-sdhci" - "brcm,bcm7425-sdhci"
- "brcm,bcm7445-sdhci" - "brcm,bcm7445-sdhci"
- "brcm,bcm7216-sdhci"
Refer to clocks/clock-bindings.txt for generic clock consumer properties. Refer to clocks/clock-bindings.txt for generic clock consumer properties.
Example: Example:
sdhci@f03e0100 { sdhci@84b0000 {
compatible = "brcm,bcm7425-sdhci";
reg = <0xf03e0000 0x100>;
interrupts = <0x0 0x26 0x0>;
sdhci,auto-cmd12;
clocks = <&sw_sdio>;
sd-uhs-sdr50; sd-uhs-sdr50;
sd-uhs-ddr50; sd-uhs-ddr50;
sd-uhs-sdr104;
sdhci,auto-cmd12;
compatible = "brcm,bcm7216-sdhci",
"brcm,bcm7445-sdhci",
"brcm,sdhci-brcmstb";
reg = <0x84b0000 0x260 0x84b0300 0x200>;
reg-names = "host", "cfg";
interrupts = <0x0 0x26 0x4>;
interrupt-names = "sdio0_0";
clocks = <&scmi_clk 245>;
clock-names = "sw_sdio";
}; };
sdhci@f03e0300 { sdhci@84b1000 {
mmc-ddr-1_8v;
mmc-hs200-1_8v;
mmc-hs400-1_8v;
mmc-hs400-enhanced-strobe;
supports-cqe;
non-removable; non-removable;
bus-width = <0x8>; bus-width = <0x8>;
compatible = "brcm,bcm7425-sdhci"; compatible = "brcm,bcm7216-sdhci",
reg = <0xf03e0200 0x100>; "brcm,bcm7445-sdhci",
interrupts = <0x0 0x27 0x0>; "brcm,sdhci-brcmstb";
sdhci,auto-cmd12; reg = <0x84b1000 0x260 0x84b1300 0x200>;
clocks = <sw_sdio>; reg-names = "host", "cfg";
mmc-hs200-1_8v; interrupts = <0x0 0x27 0x4>;
interrupt-names = "sdio1_0";
clocks = <&scmi_clk 245>;
clock-names = "sw_sdio";
}; };

1
Documentation/devicetree/bindings/mmc/fsl-imx-esdhc.txt
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@@ -21,6 +21,7 @@ Required properties:
"fsl,imx8mq-usdhc" "fsl,imx8mq-usdhc"
"fsl,imx8mm-usdhc" "fsl,imx8mm-usdhc"
"fsl,imx8mn-usdhc" "fsl,imx8mn-usdhc"
"fsl,imx8mp-usdhc"
"fsl,imx8qxp-usdhc" "fsl,imx8qxp-usdhc"
Optional properties: Optional properties:

3
Documentation/devicetree/bindings/mmc/renesas,sdhi.txt
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@@ -23,7 +23,8 @@ Required properties:
"renesas,sdhi-r8a7793" - SDHI IP on R8A7793 SoC "renesas,sdhi-r8a7793" - SDHI IP on R8A7793 SoC
"renesas,sdhi-r8a7794" - SDHI IP on R8A7794 SoC "renesas,sdhi-r8a7794" - SDHI IP on R8A7794 SoC
"renesas,sdhi-r8a7795" - SDHI IP on R8A7795 SoC "renesas,sdhi-r8a7795" - SDHI IP on R8A7795 SoC
"renesas,sdhi-r8a7796" - SDHI IP on R8A7796 SoC "renesas,sdhi-r8a7796" - SDHI IP on R8A77960 SoC
"renesas,sdhi-r8a77961" - SDHI IP on R8A77961 SoC
"renesas,sdhi-r8a77965" - SDHI IP on R8A77965 SoC "renesas,sdhi-r8a77965" - SDHI IP on R8A77965 SoC
"renesas,sdhi-r8a77970" - SDHI IP on R8A77970 SoC "renesas,sdhi-r8a77970" - SDHI IP on R8A77970 SoC
"renesas,sdhi-r8a77980" - SDHI IP on R8A77980 SoC "renesas,sdhi-r8a77980" - SDHI IP on R8A77980 SoC

49
Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.txt
View File

@@ -1,49 +0,0 @@
* Rockchip specific extensions to the Synopsys Designware Mobile
Storage Host Controller
The Synopsys designware mobile storage host controller is used to interface
a SoC with storage medium such as eMMC or SD/MMC cards. This file documents
differences between the core Synopsys dw mshc controller properties described
by synopsys-dw-mshc.txt and the properties used by the Rockchip specific
extensions to the Synopsys Designware Mobile Storage Host Controller.
Required Properties:
* compatible: should be
- "rockchip,rk2928-dw-mshc": for Rockchip RK2928 and following,
before RK3288
- "rockchip,rk3288-dw-mshc": for Rockchip RK3288
- "rockchip,rv1108-dw-mshc", "rockchip,rk3288-dw-mshc": for Rockchip RV1108
- "rockchip,px30-dw-mshc", "rockchip,rk3288-dw-mshc": for Rockchip PX30
- "rockchip,rk3036-dw-mshc", "rockchip,rk3288-dw-mshc": for Rockchip RK3036
- "rockchip,rk3228-dw-mshc", "rockchip,rk3288-dw-mshc": for Rockchip RK322x
- "rockchip,rk3328-dw-mshc", "rockchip,rk3288-dw-mshc": for Rockchip RK3328
- "rockchip,rk3368-dw-mshc", "rockchip,rk3288-dw-mshc": for Rockchip RK3368
- "rockchip,rk3399-dw-mshc", "rockchip,rk3288-dw-mshc": for Rockchip RK3399
Optional Properties:
* clocks: from common clock binding: if ciu-drive and ciu-sample are
specified in clock-names, should contain handles to these clocks.
* clock-names: Apart from the clock-names described in synopsys-dw-mshc.txt
two more clocks "ciu-drive" and "ciu-sample" are supported. They are used
to control the clock phases, "ciu-sample" is required for tuning high-
speed modes.
* rockchip,default-sample-phase: The default phase to set ciu-sample at
probing, low speeds or in case where all phases work at tuning time.
If not specified 0 deg will be used.
* rockchip,desired-num-phases: The desired number of times that the host
execute tuning when needed. If not specified, the host will do tuning
for 360 times, namely tuning for each degree.
Example:
rkdwmmc0@12200000 {
compatible = "rockchip,rk3288-dw-mshc";
reg = <0x12200000 0x1000>;
interrupts = <0 75 0>;
#address-cells = <1>;
#size-cells = <0>;
};

125
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@@ -0,0 +1,125 @@
# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/mmc/rockchip-dw-mshc.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Rockchip designware mobile storage host controller device tree bindings
description:
Rockchip uses the Synopsys designware mobile storage host controller
to interface a SoC with storage medium such as eMMC or SD/MMC cards.
This file documents the combined properties for the core Synopsys dw mshc
controller that are not already included in the synopsys-dw-mshc-common.yaml
file and the Rockchip specific extensions.
allOf:
- $ref: "synopsys-dw-mshc-common.yaml#"
maintainers:
- Heiko Stuebner <heiko@sntech.de>
# Everything else is described in the common file
properties:
compatible:
oneOf:
# for Rockchip RK2928 and before RK3288
- const: rockchip,rk2928-dw-mshc
# for Rockchip RK3288
- const: rockchip,rk3288-dw-mshc
- items:
- enum:
# for Rockchip PX30
- rockchip,px30-dw-mshc
# for Rockchip RK3036
- rockchip,rk3036-dw-mshc
# for Rockchip RK322x
- rockchip,rk3228-dw-mshc
# for Rockchip RK3308
- rockchip,rk3308-dw-mshc
# for Rockchip RK3328
- rockchip,rk3328-dw-mshc
# for Rockchip RK3368
- rockchip,rk3368-dw-mshc
# for Rockchip RK3399
- rockchip,rk3399-dw-mshc
# for Rockchip RV1108
- rockchip,rv1108-dw-mshc
- const: rockchip,rk3288-dw-mshc
reg:
maxItems: 1
interrupts:
maxItems: 1
clocks:
minItems: 2
maxItems: 4
description:
Handle to "biu" and "ciu" clocks for the bus interface unit clock and
the card interface unit clock. If "ciu-drive" and "ciu-sample" are
specified in clock-names, it should also contain
handles to these clocks.
clock-names:
minItems: 2
items:
- const: biu
- const: ciu
- const: ciu-drive
- const: ciu-sample
description:
Apart from the clock-names "biu" and "ciu" two more clocks
"ciu-drive" and "ciu-sample" are supported. They are used
to control the clock phases, "ciu-sample" is required for tuning
high speed modes.
rockchip,default-sample-phase:
allOf:
- $ref: /schemas/types.yaml#/definitions/uint32
minimum: 0
maximum: 360
default: 0
description:
The default phase to set "ciu-sample" at probing,
low speeds or in case where all phases work at tuning time.
If not specified 0 deg will be used.
rockchip,desired-num-phases:
allOf:
- $ref: /schemas/types.yaml#/definitions/uint32
minimum: 0
maximum: 360
default: 360
description:
The desired number of times that the host execute tuning when needed.
If not specified, the host will do tuning for 360 times,
namely tuning for each degree.
required:
- compatible
- reg
- interrupts
- clocks
- clock-names
examples:
- |
#include <dt-bindings/clock/rk3288-cru.h>
#include <dt-bindings/interrupt-controller/arm-gic.h>
#include <dt-bindings/interrupt-controller/irq.h>
sdmmc: mmc@ff0c0000 {
compatible = "rockchip,rk3288-dw-mshc";
reg = <0x0 0xff0c0000 0x0 0x4000>;
interrupts = <GIC_SPI 32 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&cru HCLK_SDMMC>, <&cru SCLK_SDMMC>,
<&cru SCLK_SDMMC_DRV>, <&cru SCLK_SDMMC_SAMPLE>;
clock-names = "biu", "ciu", "ciu-drive", "ciu-sample";
resets = <&cru SRST_MMC0>;
reset-names = "reset";
fifo-depth = <0x100>;
max-frequency = <150000000>;
};
...

13
Documentation/devicetree/bindings/mmc/sdhci-atmel.txt
View File

@@ -5,11 +5,16 @@ Documentation/devicetree/bindings/mmc/mmc.txt and the properties used by the
sdhci-of-at91 driver. sdhci-of-at91 driver.
Required properties: Required properties:
- compatible: Must be "atmel,sama5d2-sdhci". - compatible: Must be "atmel,sama5d2-sdhci" or "microchip,sam9x60-sdhci".
- clocks: Phandlers to the clocks. - clocks: Phandlers to the clocks.
- clock-names: Must be "hclock", "multclk", "baseclk"; - clock-names: Must be "hclock", "multclk", "baseclk" for
"atmel,sama5d2-sdhci".
Must be "hclock", "multclk" for "microchip,sam9x60-sdhci".
Optional properties: Optional properties:
- assigned-clocks: The same with "multclk".
- assigned-clock-rates The rate of "multclk" in order to not rely on the
gck configuration set by previous components.
- microchip,sdcal-inverted: when present, polarity on the SDCAL SoC pin is - microchip,sdcal-inverted: when present, polarity on the SDCAL SoC pin is
inverted. The default polarity for this signal is described in the datasheet. inverted. The default polarity for this signal is described in the datasheet.
For instance on SAMA5D2, the pin is usually tied to the GND with a resistor For instance on SAMA5D2, the pin is usually tied to the GND with a resistor
@@ -17,10 +22,12 @@ Optional properties:
Example: Example:
sdmmc0: sdio-host@a0000000 { mmc0: sdio-host@a0000000 {
compatible = "atmel,sama5d2-sdhci"; compatible = "atmel,sama5d2-sdhci";
reg = <0xa0000000 0x300>; reg = <0xa0000000 0x300>;
interrupts = <31 IRQ_TYPE_LEVEL_HIGH 0>; interrupts = <31 IRQ_TYPE_LEVEL_HIGH 0>;
clocks = <&sdmmc0_hclk>, <&sdmmc0_gclk>, <&main>; clocks = <&sdmmc0_hclk>, <&sdmmc0_gclk>, <&main>;
clock-names = "hclock", "multclk", "baseclk"; clock-names = "hclock", "multclk", "baseclk";
assigned-clocks = <&sdmmc0_gclk>;
assigned-clock-rates = <480000000>;
}; };

1
Documentation/devicetree/bindings/mmc/sdhci-msm.txt
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@@ -19,6 +19,7 @@ Required properties:
"qcom,msm8996-sdhci", "qcom,sdhci-msm-v4" "qcom,msm8996-sdhci", "qcom,sdhci-msm-v4"
"qcom,sdm845-sdhci", "qcom,sdhci-msm-v5" "qcom,sdm845-sdhci", "qcom,sdhci-msm-v5"
"qcom,qcs404-sdhci", "qcom,sdhci-msm-v5" "qcom,qcs404-sdhci", "qcom,sdhci-msm-v5"
"qcom,sc7180-sdhci", "qcom,sdhci-msm-v5";
NOTE that some old device tree files may be floating around that only NOTE that some old device tree files may be floating around that only
have the string "qcom,sdhci-msm-v4" without the SoC compatible string have the string "qcom,sdhci-msm-v4" without the SoC compatible string
but doing that should be considered a deprecated practice. but doing that should be considered a deprecated practice.

11
Documentation/devicetree/bindings/mmc/sdhci-omap.txt
View File

@@ -7,6 +7,8 @@ For UHS devices which require tuning, the device tree should have a "cpu_thermal
Required properties: Required properties:
- compatible: Should be "ti,dra7-sdhci" for DRA7 and DRA72 controllers - compatible: Should be "ti,dra7-sdhci" for DRA7 and DRA72 controllers
Should be "ti,k2g-sdhci" for K2G Should be "ti,k2g-sdhci" for K2G
Should be "ti,am335-sdhci" for am335x controllers
Should be "ti,am437-sdhci" for am437x controllers
- ti,hwmods: Must be "mmc<n>", <n> is controller instance starting 1 - ti,hwmods: Must be "mmc<n>", <n> is controller instance starting 1
(Not required for K2G). (Not required for K2G).
- pinctrl-names: Should be subset of "default", "hs", "sdr12", "sdr25", "sdr50", - pinctrl-names: Should be subset of "default", "hs", "sdr12", "sdr25", "sdr50",
@@ -15,6 +17,13 @@ Required properties:
"hs200_1_8v", "hs200_1_8v",
- pinctrl-<n> : Pinctrl states as described in bindings/pinctrl/pinctrl-bindings.txt - pinctrl-<n> : Pinctrl states as described in bindings/pinctrl/pinctrl-bindings.txt
Optional properties:
- dmas: List of DMA specifiers with the controller specific format as described
in the generic DMA client binding. A tx and rx specifier is required.
- dma-names: List of DMA request names. These strings correspond 1:1 with the
DMA specifiers listed in dmas. The string naming is to be "tx"
and "rx" for TX and RX DMA requests, respectively.
Example: Example:
mmc1: mmc@4809c000 { mmc1: mmc@4809c000 {
compatible = "ti,dra7-sdhci"; compatible = "ti,dra7-sdhci";
@@ -22,4 +31,6 @@ Example:
ti,hwmods = "mmc1"; ti,hwmods = "mmc1";
bus-width = <4>; bus-width = <4>;
vmmc-supply = <&vmmc>; /* phandle to regulator node */ vmmc-supply = <&vmmc>; /* phandle to regulator node */
dmas = <&sdma 61 &sdma 62>;
dma-names = "tx", "rx";
}; };

68
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@@ -0,0 +1,68 @@
# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/mmc/synopsys-dw-mshc-common.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Synopsys Designware Mobile Storage Host Controller Common Properties
allOf:
- $ref: "mmc-controller.yaml#"
maintainers:
- Ulf Hansson <ulf.hansson@linaro.org>
# Everything else is described in the common file
properties:
resets:
maxItems: 1
reset-names:
const: reset
clock-frequency:
description:
Should be the frequency (in Hz) of the ciu clock. If this
is specified and the ciu clock is specified then we'll try to set the ciu
clock to this at probe time.
fifo-depth:
allOf:
- $ref: /schemas/types.yaml#/definitions/uint32
description:
The maximum size of the tx/rx fifo's. If this property is not
specified, the default value of the fifo size is determined from the
controller registers.
card-detect-delay:
allOf:
- $ref: /schemas/types.yaml#/definitions/uint32
- default: 0
description:
Delay in milli-seconds before detecting card after card
insert event. The default value is 0.
data-addr:
allOf:
- $ref: /schemas/types.yaml#/definitions/uint32
description:
Override fifo address with value provided by DT. The default FIFO reg
offset is assumed as 0x100 (version < 0x240A) and 0x200(version >= 0x240A)
by driver. If the controller does not follow this rule, please use
this property to set fifo address in device tree.
fifo-watermark-aligned:
allOf:
- $ref: /schemas/types.yaml#/definitions/flag
description:
Data done irq is expected if data length is less than
watermark in PIO mode. But fifo watermark is requested to be aligned
with data length in some SoC so that TX/RX irq can be generated with
data done irq. Add this watermark quirk to mark this requirement and
force fifo watermark setting accordingly.
dmas:
maxItems: 1
dma-names:
const: rx-tx

141
Documentation/devicetree/bindings/mmc/synopsys-dw-mshc.txt
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@@ -1,141 +0,0 @@
* Synopsys Designware Mobile Storage Host Controller
The Synopsys designware mobile storage host controller is used to interface
a SoC with storage medium such as eMMC or SD/MMC cards. This file documents
differences between the core mmc properties described by mmc.txt and the
properties used by the Synopsys Designware Mobile Storage Host Controller.
Required Properties:
* compatible: should be
- snps,dw-mshc: for controllers compliant with synopsys dw-mshc.
* #address-cells: should be 1.
* #size-cells: should be 0.
# Slots (DEPRECATED): The slot specific information are contained within
child-nodes with each child-node representing a supported slot. There should
be atleast one child node representing a card slot. The name of the child node
representing the slot is recommended to be slot@n where n is the unique number
of the slot connected to the controller. The following are optional properties
which can be included in the slot child node.
* reg: specifies the physical slot number. The valid values of this
property is 0 to (num-slots -1), where num-slots is the value
specified by the num-slots property.
* bus-width: as documented in mmc core bindings.
* wp-gpios: specifies the write protect gpio line. The format of the
gpio specifier depends on the gpio controller. If a GPIO is not used
for write-protect, this property is optional.
* disable-wp: If the wp-gpios property isn't present then (by default)
we'd assume that the write protect is hooked up directly to the
controller's special purpose write protect line (accessible via
the WRTPRT register). However, it's possible that we simply don't
want write protect. In that case specify 'disable-wp'.
NOTE: This property is not required for slots known to always
connect to eMMC or SDIO cards.
Optional properties:
* resets: phandle + reset specifier pair, intended to represent hardware
reset signal present internally in some host controller IC designs.
See Documentation/devicetree/bindings/reset/reset.txt for details.
* reset-names: request name for using "resets" property. Must be "reset".
(It will be used together with "resets" property.)
* clocks: from common clock binding: handle to biu and ciu clocks for the
bus interface unit clock and the card interface unit clock.
* clock-names: from common clock binding: Shall be "biu" and "ciu".
If the biu clock is missing we'll simply skip enabling it. If the
ciu clock is missing we'll just assume that the clock is running at
clock-frequency. It is an error to omit both the ciu clock and the
clock-frequency.
* clock-frequency: should be the frequency (in Hz) of the ciu clock. If this
is specified and the ciu clock is specified then we'll try to set the ciu
clock to this at probe time.
* fifo-depth: The maximum size of the tx/rx fifo's. If this property is not
specified, the default value of the fifo size is determined from the
controller registers.
* card-detect-delay: Delay in milli-seconds before detecting card after card
insert event. The default value is 0.
* data-addr: Override fifo address with value provided by DT. The default FIFO reg
offset is assumed as 0x100 (version < 0x240A) and 0x200(version >= 0x240A) by
driver. If the controller does not follow this rule, please use this property
to set fifo address in device tree.
* fifo-watermark-aligned: Data done irq is expected if data length is less than
watermark in PIO mode. But fifo watermark is requested to be aligned with data
length in some SoC so that TX/RX irq can be generated with data done irq. Add this
watermark quirk to mark this requirement and force fifo watermark setting
accordingly.
* vmmc-supply: The phandle to the regulator to use for vmmc. If this is
specified we'll defer probe until we can find this regulator.
* dmas: List of DMA specifiers with the controller specific format as described
in the generic DMA client binding. Refer to dma.txt for details.
* dma-names: request names for generic DMA client binding. Must be "rx-tx".
Refer to dma.txt for details.
Aliases:
- All the MSHC controller nodes should be represented in the aliases node using
the following format 'mshc{n}' where n is a unique number for the alias.
Example:
The MSHC controller node can be split into two portions, SoC specific and
board specific portions as listed below.
dwmmc0@12200000 {
compatible = "snps,dw-mshc";
clocks = <&clock 351>, <&clock 132>;
clock-names = "biu", "ciu";
reg = <0x12200000 0x1000>;
interrupts = <0 75 0>;
#address-cells = <1>;
#size-cells = <0>;
data-addr = <0x200>;
fifo-watermark-aligned;
resets = <&rst 20>;
reset-names = "reset";
};
[board specific internal DMA resources]
dwmmc0@12200000 {
clock-frequency = <400000000>;
clock-freq-min-max = <400000 200000000>;
broken-cd;
fifo-depth = <0x80>;
card-detect-delay = <200>;
vmmc-supply = <&buck8>;
bus-width = <8>;
cap-mmc-highspeed;
cap-sd-highspeed;
};
[board specific generic DMA request binding]
dwmmc0@12200000 {
clock-frequency = <400000000>;
clock-freq-min-max = <400000 200000000>;
broken-cd;
fifo-depth = <0x80>;
card-detect-delay = <200>;
vmmc-supply = <&buck8>;
bus-width = <8>;
cap-mmc-highspeed;
cap-sd-highspeed;
dmas = <&pdma 12>;
dma-names = "rx-tx";
};

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# SPDX-License-Identifier: GPL-2.0
%YAML 1.2
---
$id: http://devicetree.org/schemas/mmc/synopsys-dw-mshc.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Synopsys Designware Mobile Storage Host Controller Binding
allOf:
- $ref: "synopsys-dw-mshc-common.yaml#"
maintainers:
- Ulf Hansson <ulf.hansson@linaro.org>
# Everything else is described in the common file
properties:
compatible:
const: snps,dw-mshc
reg:
maxItems: 1
interrupts:
maxItems: 1
clocks:
minItems: 2
maxItems: 2
description:
Handle to "biu" and "ciu" clocks for the
bus interface unit clock and the card interface unit clock.
clock-names:
items:
- const: biu
- const: ciu
required:
- compatible
- reg
- interrupts
- clocks
- clock-names
examples:
- |
mmc@12200000 {
compatible = "snps,dw-mshc";
reg = <0x12200000 0x1000>;
interrupts = <0 75 0>;
clocks = <&clock 351>, <&clock 132>;
clock-names = "biu", "ciu";
dmas = <&pdma 12>;
dma-names = "rx-tx";
resets = <&rst 20>;
reset-names = "reset";
vmmc-supply = <&buck8>;
#address-cells = <1>;
#size-cells = <0>;
broken-cd;
bus-width = <8>;
cap-mmc-highspeed;
cap-sd-highspeed;
card-detect-delay = <200>;
clock-freq-min-max = <400000 200000000>;
clock-frequency = <400000000>;
data-addr = <0x200>;
fifo-depth = <0x80>;
fifo-watermark-aligned;
};

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QCOM CPR (Core Power Reduction)
CPR (Core Power Reduction) is a technology to reduce core power on a CPU
or other device. Each OPP of a device corresponds to a "corner" that has
a range of valid voltages for a particular frequency. While the device is
running at a particular frequency, CPR monitors dynamic factors such as
temperature, etc. and suggests adjustments to the voltage to save power
and meet silicon characteristic requirements.
- compatible:
Usage: required
Value type: <string>
Definition: should be "qcom,qcs404-cpr", "qcom,cpr" for qcs404
- reg:
Usage: required
Value type: <prop-encoded-array>
Definition: base address and size of the rbcpr register region
- interrupts:
Usage: required
Value type: <prop-encoded-array>
Definition: should specify the CPR interrupt
- clocks:
Usage: required
Value type: <prop-encoded-array>
Definition: phandle to the reference clock
- clock-names:
Usage: required
Value type: <stringlist>
Definition: must be "ref"
- vdd-apc-supply:
Usage: required
Value type: <phandle>
Definition: phandle to the vdd-apc-supply regulator
- #power-domain-cells:
Usage: required
Value type: <u32>
Definition: should be 0
- operating-points-v2:
Usage: required
Value type: <phandle>
Definition: A phandle to the OPP table containing the
performance states supported by the CPR
power domain
- acc-syscon:
Usage: optional
Value type: <phandle>
Definition: phandle to syscon for writing ACC settings
- nvmem-cells:
Usage: required
Value type: <phandle>
Definition: phandle to nvmem cells containing the data
that makes up a fuse corner, for each fuse corner.
As well as the CPR fuse revision.
- nvmem-cell-names:
Usage: required
Value type: <stringlist>
Definition: should be "cpr_quotient_offset1", "cpr_quotient_offset2",
"cpr_quotient_offset3", "cpr_init_voltage1",
"cpr_init_voltage2", "cpr_init_voltage3", "cpr_quotient1",
"cpr_quotient2", "cpr_quotient3", "cpr_ring_osc1",
"cpr_ring_osc2", "cpr_ring_osc3", "cpr_fuse_revision"
for qcs404.
Example:
cpr_opp_table: cpr-opp-table {
compatible = "operating-points-v2-qcom-level";
cpr_opp1: opp1 {
opp-level = <1>;
qcom,opp-fuse-level = <1>;
};
cpr_opp2: opp2 {
opp-level = <2>;
qcom,opp-fuse-level = <2>;
};
cpr_opp3: opp3 {
opp-level = <3>;
qcom,opp-fuse-level = <3>;
};
};
power-controller@b018000 {
compatible = "qcom,qcs404-cpr", "qcom,cpr";
reg = <0x0b018000 0x1000>;
interrupts = <0 15 IRQ_TYPE_EDGE_RISING>;
clocks = <&xo_board>;
clock-names = "ref";
vdd-apc-supply = <&pms405_s3>;
#power-domain-cells = <0>;
operating-points-v2 = <&cpr_opp_table>;
acc-syscon = <&tcsr>;
nvmem-cells = <&cpr_efuse_quot_offset1>,
<&cpr_efuse_quot_offset2>,
<&cpr_efuse_quot_offset3>,
<&cpr_efuse_init_voltage1>,
<&cpr_efuse_init_voltage2>,
<&cpr_efuse_init_voltage3>,
<&cpr_efuse_quot1>,
<&cpr_efuse_quot2>,
<&cpr_efuse_quot3>,
<&cpr_efuse_ring1>,
<&cpr_efuse_ring2>,
<&cpr_efuse_ring3>,
<&cpr_efuse_revision>;
nvmem-cell-names = "cpr_quotient_offset1",
"cpr_quotient_offset2",
"cpr_quotient_offset3",
"cpr_init_voltage1",
"cpr_init_voltage2",
"cpr_init_voltage3",
"cpr_quotient1",
"cpr_quotient2",
"cpr_quotient3",
"cpr_ring_osc1",
"cpr_ring_osc2",
"cpr_ring_osc3",
"cpr_fuse_revision";
};

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Monolithic Power Systems MP8859 voltage regulator
Required properties:
- compatible: "mps,mp8859";
- reg: I2C slave address.
Optional subnode for regulator: "mp8859_dcdc", using common regulator
bindings given in <Documentation/devicetree/bindings/regulator/regulator.txt>.
Example:
mp8859: regulator@66 {
compatible = "mps,mp8859";
reg = <0x66>;
dc_12v: mp8859_dcdc {
regulator-name = "dc_12v";
regulator-min-microvolt = <12000000>;
regulator-max-microvolt = <12000000>;
regulator-boot-on;
regulator-always-on;
};
};

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# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
%YAML 1.2
---
$id: http://devicetree.org/schemas/regulator/mps,mpq7920.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: Monolithic Power System MPQ7920 PMIC
maintainers:
- Saravanan Sekar <sravanhome@gmail.com>
properties:
$nodename:
pattern: "pmic@[0-9a-f]{1,2}"
compatible:
enum:
- mps,mpq7920
reg:
maxItems: 1
regulators:
type: object
allOf:
- $ref: regulator.yaml#
description: |
list of regulators provided by this controller, must be named
after their hardware counterparts BUCK[1-4], one LDORTC, and LDO[2-5]
properties:
mps,switch-freq:
allOf:
- $ref: "/schemas/types.yaml#/definitions/uint8"
enum: [ 0, 1, 2, 3 ]
default: 2
description: |
switching frequency must be one of following corresponding value
1.1MHz, 1.65MHz, 2.2MHz, 2.75MHz
patternProperties:
"^ldo[1-4]$":
type: object
allOf:
- $ref: regulator.yaml#
"^ldortc$":
type: object
allOf:
- $ref: regulator.yaml#
"^buck[1-4]$":
type: object
allOf:
- $ref: regulator.yaml#
properties:
mps,buck-softstart:
allOf:
- $ref: "/schemas/types.yaml#/definitions/uint8"
enum: [ 0, 1, 2, 3 ]
description: |
defines the soft start time of this buck, must be one of the following
corresponding values 150us, 300us, 610us, 920us
mps,buck-phase-delay:
allOf:
- $ref: "/schemas/types.yaml#/definitions/uint8"
enum: [ 0, 1, 2, 3 ]
description: |
defines the phase delay of this buck, must be one of the following
corresponding values 0deg, 90deg, 180deg, 270deg
mps,buck-ovp-disable:
type: boolean
description: |
disables over voltage protection of this buck
additionalProperties: false
additionalProperties: false
required:
- compatible
- reg
- regulators
additionalProperties: false
examples:
- |
i2c {
#address-cells = <1>;
#size-cells = <0>;
pmic@69 {
compatible = "mps,mpq7920";
reg = <0x69>;
regulators {
mps,switch-freq = /bits/ 8 <1>;
buck1 {
regulator-name = "buck1";
regulator-min-microvolt = <400000>;
regulator-max-microvolt = <3587500>;
regulator-min-microamp = <460000>;
regulator-max-microamp = <7600000>;
regulator-boot-on;
mps,buck-ovp-disable;
mps,buck-phase-delay = /bits/ 8 <2>;
mps,buck-softstart = /bits/ 8 <1>;
};
ldo2 {
regulator-name = "ldo2";
regulator-min-microvolt = <650000>;
regulator-max-microvolt = <3587500>;
};
};
};
};
...

107
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# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
%YAML 1.2
---
$id: http://devicetree.org/schemas/regulator/rohm,bd71828-regulator.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: ROHM BD71828 Power Management Integrated Circuit regulators
maintainers:
- Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
description: |
This module is part of the ROHM BD71828 MFD device. For more details
see Documentation/devicetree/bindings/mfd/rohm,bd71828-pmic.yaml.
The regulator controller is represented as a sub-node of the PMIC node
on the device tree.
Regulator nodes should be named to BUCK_<number> and LDO_<number>.
The valid names for BD71828 regulator nodes are
BUCK1, BUCK2, BUCK3, BUCK4, BUCK5, BUCK6, BUCK7
LDO1, LDO2, LDO3, LDO4, LDO5, LDO6, LDO7
patternProperties:
"^LDO[1-7]$":
type: object
allOf:
- $ref: regulator.yaml#
description:
Properties for single LDO regulator.
properties:
regulator-name:
pattern: "^ldo[1-7]$"
description:
should be "ldo1", ..., "ldo7"
"^BUCK[1-7]$":
type: object
allOf:
- $ref: regulator.yaml#
description:
Properties for single BUCK regulator.
properties:
regulator-name:
pattern: "^buck[1-7]$"
description:
should be "buck1", ..., "buck7"
rohm,dvs-run-voltage:
allOf:
- $ref: "/schemas/types.yaml#/definitions/uint32"
- minimum: 0
maximum: 3300000
description:
PMIC default "RUN" state voltage in uV. See below table for
bucks which support this. 0 means disabled.
rohm,dvs-idle-voltage:
allOf:
- $ref: "/schemas/types.yaml#/definitions/uint32"
- minimum: 0
maximum: 3300000
description:
PMIC default "IDLE" state voltage in uV. See below table for
bucks which support this. 0 means disabled.
rohm,dvs-suspend-voltage:
allOf:
- $ref: "/schemas/types.yaml#/definitions/uint32"
- minimum: 0
maximum: 3300000
description:
PMIC default "SUSPEND" state voltage in uV. See below table for
bucks which support this. 0 means disabled.
rohm,dvs-lpsr-voltage:
allOf:
- $ref: "/schemas/types.yaml#/definitions/uint32"
- minimum: 0
maximum: 3300000
description:
PMIC default "LPSR" state voltage in uV. See below table for
bucks which support this. 0 means disabled.
# Supported default DVS states:
# buck | run | idle | suspend | lpsr
#--------------------------------------------------------------
# 1, 2, 6, and 7 | supported | supported | supported (*)
#--------------------------------------------------------------
# 3, 4, and 5 | supported (**)
#--------------------------------------------------------------
#
#(*) LPSR and SUSPEND states use same voltage but both states have own
# enable /
# disable settings. Voltage 0 can be specified for a state to make
# regulator disabled on that state.
#
#(**) All states use same voltage but have own enable / disable
# settings. Voltage 0 can be specified for a state to make
# regulator disabled on that state.
required:
- regulator-name
additionalProperties: false
additionalProperties: false

18
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STM32 BOOSTER - Booster for ADC analog input switches
Some STM32 devices embed a 3.3V booster supplied by Vdda, that can be used
to supply ADC analog input switches.
Required properties:
- compatible: Should be one of:
"st,stm32h7-booster"
"st,stm32mp1-booster"
- st,syscfg: Phandle to system configuration controller.
- vdda-supply: Phandle to the vdda input analog voltage.
Example:
booster: regulator-booster {
compatible = "st,stm32mp1-booster";
st,syscfg = <&syscfg>;
vdda-supply = <&vdda>;
};

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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/regulator/st,stm32-booster.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: STMicroelectronics STM32 booster for ADC analog input switches bindings
maintainers:
- Fabrice Gasnier <fabrice.gasnier@st.com>
description: |
Some STM32 devices embed a 3.3V booster supplied by Vdda, that can be used
to supply ADC analog input switches.
allOf:
- $ref: "regulator.yaml#"
properties:
compatible:
enum:
- st,stm32h7-booster
- st,stm32mp1-booster
st,syscfg:
allOf:
- $ref: "/schemas/types.yaml#/definitions/phandle-array"
description: phandle to system configuration controller.
vdda-supply:
description: phandle to the vdda input analog voltage.
required:
- compatible
- st,syscfg
- vdda-supply
examples:
- |
regulator-booster {
compatible = "st,stm32mp1-booster";
st,syscfg = <&syscfg>;
vdda-supply = <&vdda>;
};
...

20
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@@ -1,20 +0,0 @@
STM32 VREFBUF - Voltage reference buffer
Some STM32 devices embed a voltage reference buffer which can be used as
voltage reference for ADCs, DACs and also as voltage reference for external
components through the dedicated VREF+ pin.
Required properties:
- compatible: Must be "st,stm32-vrefbuf".
- reg: Offset and length of VREFBUF register set.
- clocks: Must contain an entry for peripheral clock.
Example:
vrefbuf: regulator@58003c00 {
compatible = "st,stm32-vrefbuf";
reg = <0x58003C00 0x8>;
clocks = <&rcc VREF_CK>;
regulator-min-microvolt = <1500000>;
regulator-max-microvolt = <2500000>;
vdda-supply = <&vdda>;
};

52
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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/regulator/st,stm32-vrefbuf.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: STMicroelectronics STM32 Voltage reference buffer bindings
description: |
Some STM32 devices embed a voltage reference buffer which can be used as
voltage reference for ADCs, DACs and also as voltage reference for external
components through the dedicated VREF+ pin.
maintainers:
- Fabrice Gasnier <fabrice.gasnier@st.com>
allOf:
- $ref: "regulator.yaml#"
properties:
compatible:
const: st,stm32-vrefbuf
reg:
maxItems: 1
clocks:
maxItems: 1
vdda-supply:
description: phandle to the vdda input analog voltage.
required:
- compatible
- reg
- clocks
- vdda-supply
examples:
- |
#include <dt-bindings/clock/stm32mp1-clks.h>
vrefbuf@50025000 {
compatible = "st,stm32-vrefbuf";
reg = <0x50025000 0x8>;
regulator-min-microvolt = <1500000>;
regulator-max-microvolt = <2500000>;
clocks = <&rcc VREF>;
vdda-supply = <&vdda>;
};
...

43
Documentation/devicetree/bindings/regulator/st,stm32mp1-pwr-reg.txt
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@@ -1,43 +0,0 @@
STM32MP1 PWR Regulators
-----------------------
Available Regulators in STM32MP1 PWR block are:
- reg11 for regulator 1V1
- reg18 for regulator 1V8
- usb33 for the swtich USB3V3
Required properties:
- compatible: Must be "st,stm32mp1,pwr-reg"
- list of child nodes that specify the regulator reg11, reg18 or usb33
initialization data for defined regulators. The definition for each of
these nodes is defined using the standard binding for regulators found at
Documentation/devicetree/bindings/regulator/regulator.txt.
- vdd-supply: phandle to the parent supply/regulator node for vdd input
- vdd_3v3_usbfs-supply: phandle to the parent supply/regulator node for usb33
Example:
pwr_regulators: pwr@50001000 {
compatible = "st,stm32mp1,pwr-reg";
reg = <0x50001000 0x10>;
vdd-supply = <&vdd>;
vdd_3v3_usbfs-supply = <&vdd_usb>;
reg11: reg11 {
regulator-name = "reg11";
regulator-min-microvolt = <1100000>;
regulator-max-microvolt = <1100000>;
};
reg18: reg18 {
regulator-name = "reg18";
regulator-min-microvolt = <1800000>;
regulator-max-microvolt = <1800000>;
};
usb33: usb33 {
regulator-name = "usb33";
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
};
};

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# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/regulator/st,stm32mp1-pwr-reg.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: STM32MP1 PWR voltage regulators
maintainers:
- Pascal Paillet <p.paillet@st.com>
properties:
compatible:
const: st,stm32mp1,pwr-reg
reg:
maxItems: 1
vdd-supply:
description: Input supply phandle(s) for vdd input
vdd_3v3_usbfs-supply:
description: Input supply phandle(s) for vdd_3v3_usbfs input
patternProperties:
"^(reg11|reg18|usb33)$":
type: object
allOf:
- $ref: "regulator.yaml#"
required:
- compatible
- reg
additionalProperties: false
examples:
- |
pwr@50001000 {
compatible = "st,stm32mp1,pwr-reg";
reg = <0x50001000 0x10>;
vdd-supply = <&vdd>;
vdd_3v3_usbfs-supply = <&vdd_usb>;
reg11 {
regulator-name = "reg11";
regulator-min-microvolt = <1100000>;
regulator-max-microvolt = <1100000>;
};
reg18 {
regulator-name = "reg18";
regulator-min-microvolt = <1800000>;
regulator-max-microvolt = <1800000>;
};
usb33 {
regulator-name = "usb33";
regulator-min-microvolt = <3300000>;
regulator-max-microvolt = <3300000>;
};
};
...

59
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* Texas Instruments K3 NavigatorSS Ring Accelerator
The Ring Accelerator (RA) is a machine which converts read/write accesses
from/to a constant address into corresponding read/write accesses from/to a
circular data structure in memory. The RA eliminates the need for each DMA
controller which needs to access ring elements from having to know the current
state of the ring (base address, current offset). The DMA controller
performs a read or write access to a specific address range (which maps to the
source interface on the RA) and the RA replaces the address for the transaction
with a new address which corresponds to the head or tail element of the ring
(head for reads, tail for writes).
The Ring Accelerator is a hardware module that is responsible for accelerating
management of the packet queues. The K3 SoCs can have more than one RA instances
Required properties:
- compatible : Must be "ti,am654-navss-ringacc";
- reg : Should contain register location and length of the following
named register regions.
- reg-names : should be
"rt" - The RA Ring Real-time Control/Status Registers
"fifos" - The RA Queues Registers
"proxy_gcfg" - The RA Proxy Global Config Registers
"proxy_target" - The RA Proxy Datapath Registers
- ti,num-rings : Number of rings supported by RA
- ti,sci-rm-range-gp-rings : TI-SCI RM subtype for GP ring range
- ti,sci : phandle on TI-SCI compatible System controller node
- ti,sci-dev-id : TI-SCI device id of the ring accelerator
- msi-parent : phandle for "ti,sci-inta" interrupt controller
Optional properties:
-- ti,dma-ring-reset-quirk : enable ringacc / udma ring state interoperability
issue software w/a
Example:
ringacc: ringacc@3c000000 {
compatible = "ti,am654-navss-ringacc";
reg = <0x0 0x3c000000 0x0 0x400000>,
<0x0 0x38000000 0x0 0x400000>,
<0x0 0x31120000 0x0 0x100>,
<0x0 0x33000000 0x0 0x40000>;
reg-names = "rt", "fifos",
"proxy_gcfg", "proxy_target";
ti,num-rings = <818>;
ti,sci-rm-range-gp-rings = <0x2>; /* GP ring range */
ti,dma-ring-reset-quirk;
ti,sci = <&dmsc>;
ti,sci-dev-id = <187>;
msi-parent = <&inta_main_udmass>;
};
client:
dma_ipx: dma_ipx@<addr> {
...
ti,ringacc = <&ringacc>;
...
}

12
Documentation/devicetree/bindings/spi/nuvoton,npcm-pspi.txt
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@@ -12,6 +12,7 @@ Required properties:
- clock-names: Should be "clk_apb5". - clock-names: Should be "clk_apb5".
- pinctrl-names : a pinctrl state named "default" must be defined. - pinctrl-names : a pinctrl state named "default" must be defined.
- pinctrl-0 : phandle referencing pin configuration of the device. - pinctrl-0 : phandle referencing pin configuration of the device.
- resets : phandle to the reset control for this device.
- cs-gpios: Specifies the gpio pins to be used for chipselects. - cs-gpios: Specifies the gpio pins to be used for chipselects.
See: Documentation/devicetree/bindings/spi/spi-bus.txt See: Documentation/devicetree/bindings/spi/spi-bus.txt
@@ -19,16 +20,6 @@ Optional properties:
- clock-frequency : Input clock frequency to the PSPI block in Hz. - clock-frequency : Input clock frequency to the PSPI block in Hz.
Default is 25000000 Hz. Default is 25000000 Hz.
Aliases:
- All the SPI controller nodes should be represented in the aliases node using
the following format 'spi{n}' withe the correct numbered in "aliases" node.
Example:
aliases {
spi0 = &spi0;
};
spi0: spi@f0200000 { spi0: spi@f0200000 {
compatible = "nuvoton,npcm750-pspi"; compatible = "nuvoton,npcm750-pspi";
reg = <0xf0200000 0x1000>; reg = <0xf0200000 0x1000>;
@@ -39,5 +30,6 @@ spi0: spi@f0200000 {
interrupts = <GIC_SPI 31 IRQ_TYPE_LEVEL_HIGH>; interrupts = <GIC_SPI 31 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&clk NPCM7XX_CLK_APB5>; clocks = <&clk NPCM7XX_CLK_APB5>;
clock-names = "clk_apb5"; clock-names = "clk_apb5";
resets = <&rstc NPCM7XX_RESET_IPSRST2 NPCM7XX_RESET_PSPI1>
cs-gpios = <&gpio6 11 GPIO_ACTIVE_LOW>; cs-gpios = <&gpio6 11 GPIO_ACTIVE_LOW>;
}; };

62
Documentation/devicetree/bindings/spi/spi-stm32.txt
View File

@@ -1,62 +0,0 @@
STMicroelectronics STM32 SPI Controller
The STM32 SPI controller is used to communicate with external devices using
the Serial Peripheral Interface. It supports full-duplex, half-duplex and
simplex synchronous serial communication with external devices. It supports
from 4 to 32-bit data size. Although it can be configured as master or slave,
only master is supported by the driver.
Required properties:
- compatible: Should be one of:
"st,stm32h7-spi"
"st,stm32f4-spi"
- reg: Offset and length of the device's register set.
- interrupts: Must contain the interrupt id.
- clocks: Must contain an entry for spiclk (which feeds the internal clock
generator).
- #address-cells: Number of cells required to define a chip select address.
- #size-cells: Should be zero.
Optional properties:
- resets: Must contain the phandle to the reset controller.
- A pinctrl state named "default" may be defined to set pins in mode of
operation for SPI transfer.
- dmas: DMA specifiers for tx and rx dma. DMA fifo mode must be used. See the
STM32 DMA bindings, Documentation/devicetree/bindings/dma/stm32-dma.txt.
- dma-names: DMA request names should include "tx" and "rx" if present.
- cs-gpios: list of GPIO chip selects. See the SPI bus bindings,
Documentation/devicetree/bindings/spi/spi-bus.txt
Child nodes represent devices on the SPI bus
See ../spi/spi-bus.txt
Optional properties:
- st,spi-midi-ns: Only for STM32H7, (Master Inter-Data Idleness) minimum time
delay in nanoseconds inserted between two consecutive data
frames.
Example:
spi2: spi@40003800 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "st,stm32h7-spi";
reg = <0x40003800 0x400>;
interrupts = <36>;
clocks = <&rcc SPI2_CK>;
resets = <&rcc 1166>;
dmas = <&dmamux1 0 39 0x400 0x01>,
<&dmamux1 1 40 0x400 0x01>;
dma-names = "rx", "tx";
pinctrl-0 = <&spi2_pins_b>;
pinctrl-names = "default";
cs-gpios = <&gpioa 11 0>;
aardvark@0 {
compatible = "totalphase,aardvark";
reg = <0>;
spi-max-frequency = <4000000>;
st,spi-midi-ns = <4000>;
};
};

2
Documentation/devicetree/bindings/spi/spi_atmel.txt
View File

@@ -1,7 +1,7 @@
Atmel SPI device Atmel SPI device
Required properties: Required properties:
- compatible : should be "atmel,at91rm9200-spi". - compatible : should be "atmel,at91rm9200-spi" or "microchip,sam9x60-spi".
- reg: Address and length of the register set for the device - reg: Address and length of the register set for the device
- interrupts: Should contain spi interrupt - interrupts: Should contain spi interrupt
- cs-gpios: chipselects (optional for SPI controller version >= 2 with the - cs-gpios: chipselects (optional for SPI controller version >= 2 with the

105
Documentation/devicetree/bindings/spi/st,stm32-spi.yaml Normal file
View File

@@ -0,0 +1,105 @@
# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/spi/st,stm32-spi.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#
title: STMicroelectronics STM32 SPI Controller bindings
description: |
The STM32 SPI controller is used to communicate with external devices using
the Serial Peripheral Interface. It supports full-duplex, half-duplex and
simplex synchronous serial communication with external devices. It supports
from 4 to 32-bit data size.
maintainers:
- Erwan Leray <erwan.leray@st.com>
- Fabrice Gasnier <fabrice.gasnier@st.com>
allOf:
- $ref: "spi-controller.yaml#"
- if:
properties:
compatible:
contains:
const: st,stm32f4-spi
then:
properties:
st,spi-midi-ns: false
properties:
compatible:
enum:
- st,stm32f4-spi
- st,stm32h7-spi
reg:
maxItems: 1
clocks:
maxItems: 1
interrupts:
maxItems: 1
resets:
maxItems: 1
dmas:
description: |
DMA specifiers for tx and rx dma. DMA fifo mode must be used. See
the STM32 DMA bindings Documentation/devicetree/bindings/dma/stm32-dma.txt.
items:
- description: rx DMA channel
- description: tx DMA channel
dma-names:
items:
- const: rx
- const: tx
patternProperties:
"^[a-zA-Z][a-zA-Z0-9,+\\-._]{0,63}@[0-9a-f]+$":
type: object
# SPI slave nodes must be children of the SPI master node and can
# contain the following properties.
properties:
st,spi-midi-ns:
description: |
Only for STM32H7, (Master Inter-Data Idleness) minimum time
delay in nanoseconds inserted between two consecutive data frames.
required:
- compatible
- reg
- clocks
- interrupts
examples:
- |
#include <dt-bindings/interrupt-controller/arm-gic.h>
#include <dt-bindings/clock/stm32mp1-clks.h>
#include <dt-bindings/reset/stm32mp1-resets.h>
spi@4000b000 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "st,stm32h7-spi";
reg = <0x4000b000 0x400>;
interrupts = <GIC_SPI 36 IRQ_TYPE_LEVEL_HIGH>;
clocks = <&rcc SPI2_K>;
resets = <&rcc SPI2_R>;
dmas = <&dmamux1 0 39 0x400 0x05>,
<&dmamux1 1 40 0x400 0x05>;
dma-names = "rx", "tx";
cs-gpios = <&gpioa 11 0>;
aardvark@0 {
compatible = "totalphase,aardvark";
reg = <0>;
spi-max-frequency = <4000000>;
st,spi-midi-ns = <4000>;
};
};
...

2
Documentation/devicetree/bindings/timer/renesas,cmt.txt
View File

@@ -29,6 +29,8 @@ Required Properties:
- "renesas,r8a77470-cmt1" for the 48-bit CMT1 device included in r8a77470. - "renesas,r8a77470-cmt1" for the 48-bit CMT1 device included in r8a77470.
- "renesas,r8a774a1-cmt0" for the 32-bit CMT0 device included in r8a774a1. - "renesas,r8a774a1-cmt0" for the 32-bit CMT0 device included in r8a774a1.
- "renesas,r8a774a1-cmt1" for the 48-bit CMT devices included in r8a774a1. - "renesas,r8a774a1-cmt1" for the 48-bit CMT devices included in r8a774a1.
- "renesas,r8a774b1-cmt0" for the 32-bit CMT0 device included in r8a774b1.
- "renesas,r8a774b1-cmt1" for the 48-bit CMT devices included in r8a774b1.
- "renesas,r8a774c0-cmt0" for the 32-bit CMT0 device included in r8a774c0. - "renesas,r8a774c0-cmt0" for the 32-bit CMT0 device included in r8a774c0.
- "renesas,r8a774c0-cmt1" for the 48-bit CMT devices included in r8a774c0. - "renesas,r8a774c0-cmt1" for the 48-bit CMT devices included in r8a774c0.
- "renesas,r8a7790-cmt0" for the 32-bit CMT0 device included in r8a7790. - "renesas,r8a7790-cmt0" for the 32-bit CMT0 device included in r8a7790.

87
Documentation/driver-api/dmaengine/client.rst
View File

@@ -151,6 +151,93 @@ The details of these operations are:
Note that callbacks will always be invoked from the DMA Note that callbacks will always be invoked from the DMA
engines tasklet, never from interrupt context. engines tasklet, never from interrupt context.
Optional: per descriptor metadata
---------------------------------
DMAengine provides two ways for metadata support.
DESC_METADATA_CLIENT
The metadata buffer is allocated/provided by the client driver and it is
attached to the descriptor.
.. code-block:: c
int dmaengine_desc_attach_metadata(struct dma_async_tx_descriptor *desc,
void *data, size_t len);
DESC_METADATA_ENGINE
The metadata buffer is allocated/managed by the DMA driver. The client
driver can ask for the pointer, maximum size and the currently used size of
the metadata and can directly update or read it.
Becasue the DMA driver manages the memory area containing the metadata,
clients must make sure that they do not try to access or get the pointer
after their transfer completion callback has run for the descriptor.
If no completion callback has been defined for the transfer, then the
metadata must not be accessed after issue_pending.
In other words: if the aim is to read back metadata after the transfer is
completed, then the client must use completion callback.
.. code-block:: c
void *dmaengine_desc_get_metadata_ptr(struct dma_async_tx_descriptor *desc,
size_t *payload_len, size_t *max_len);
int dmaengine_desc_set_metadata_len(struct dma_async_tx_descriptor *desc,
size_t payload_len);
Client drivers can query if a given mode is supported with:
.. code-block:: c
bool dmaengine_is_metadata_mode_supported(struct dma_chan *chan,
enum dma_desc_metadata_mode mode);
Depending on the used mode client drivers must follow different flow.
DESC_METADATA_CLIENT
- DMA_MEM_TO_DEV / DEV_MEM_TO_MEM:
1. prepare the descriptor (dmaengine_prep_*)
construct the metadata in the client's buffer
2. use dmaengine_desc_attach_metadata() to attach the buffer to the
descriptor
3. submit the transfer
- DMA_DEV_TO_MEM:
1. prepare the descriptor (dmaengine_prep_*)
2. use dmaengine_desc_attach_metadata() to attach the buffer to the
descriptor
3. submit the transfer
4. when the transfer is completed, the metadata should be available in the
attached buffer
DESC_METADATA_ENGINE
- DMA_MEM_TO_DEV / DEV_MEM_TO_MEM:
1. prepare the descriptor (dmaengine_prep_*)
2. use dmaengine_desc_get_metadata_ptr() to get the pointer to the
engine's metadata area
3. update the metadata at the pointer
4. use dmaengine_desc_set_metadata_len() to tell the DMA engine the
amount of data the client has placed into the metadata buffer
5. submit the transfer
- DMA_DEV_TO_MEM:
1. prepare the descriptor (dmaengine_prep_*)
2. submit the transfer
3. on transfer completion, use dmaengine_desc_get_metadata_ptr() to get
the pointer to the engine's metadata area
4. read out the metadata from the pointer
.. note::
When DESC_METADATA_ENGINE mode is used the metadata area for the descriptor
is no longer valid after the transfer has been completed (valid up to the
point when the completion callback returns if used).
Mixed use of DESC_METADATA_CLIENT / DESC_METADATA_ENGINE is not allowed,
client drivers must use either of the modes per descriptor.
4. Submit the transaction 4. Submit the transaction
Once the descriptor has been prepared and the callback information Once the descriptor has been prepared and the callback information

48
Documentation/driver-api/dmaengine/provider.rst
View File

@@ -247,6 +247,54 @@ after each transfer. In case of a ring buffer, they may loop
(DMA_CYCLIC). Addresses pointing to a device's register (e.g. a FIFO) (DMA_CYCLIC). Addresses pointing to a device's register (e.g. a FIFO)
are typically fixed. are typically fixed.
Per descriptor metadata support
-------------------------------
Some data movement architecture (DMA controller and peripherals) uses metadata
associated with a transaction. The DMA controller role is to transfer the
payload and the metadata alongside.
The metadata itself is not used by the DMA engine itself, but it contains
parameters, keys, vectors, etc for peripheral or from the peripheral.
The DMAengine framework provides a generic ways to facilitate the metadata for
descriptors. Depending on the architecture the DMA driver can implement either
or both of the methods and it is up to the client driver to choose which one
to use.
- DESC_METADATA_CLIENT
The metadata buffer is allocated/provided by the client driver and it is
attached (via the dmaengine_desc_attach_metadata() helper to the descriptor.
From the DMA driver the following is expected for this mode:
- DMA_MEM_TO_DEV / DEV_MEM_TO_MEM
The data from the provided metadata buffer should be prepared for the DMA
controller to be sent alongside of the payload data. Either by copying to a
hardware descriptor, or highly coupled packet.
- DMA_DEV_TO_MEM
On transfer completion the DMA driver must copy the metadata to the client
provided metadata buffer before notifying the client about the completion.
After the transfer completion, DMA drivers must not touch the metadata
buffer provided by the client.
- DESC_METADATA_ENGINE
The metadata buffer is allocated/managed by the DMA driver. The client driver
can ask for the pointer, maximum size and the currently used size of the
metadata and can directly update or read it. dmaengine_desc_get_metadata_ptr()
and dmaengine_desc_set_metadata_len() is provided as helper functions.
From the DMA driver the following is expected for this mode:
- get_metadata_ptr
Should return a pointer for the metadata buffer, the maximum size of the
metadata buffer and the currently used / valid (if any) bytes in the buffer.
- set_metadata_len
It is called by the clients after it have placed the metadata to the buffer
to let the DMA driver know the number of valid bytes provided.
Note: since the client will ask for the metadata pointer in the completion
callback (in DMA_DEV_TO_MEM case) the DMA driver must ensure that the
descriptor is not freed up prior the callback is called.
Device operations Device operations
----------------- -----------------

1
Documentation/driver-api/driver-model/devres.rst
View File

@@ -313,7 +313,6 @@ IOMAP
devm_ioport_map() devm_ioport_map()
devm_ioport_unmap() devm_ioport_unmap()
devm_ioremap() devm_ioremap()
devm_ioremap_nocache()
devm_ioremap_uc() devm_ioremap_uc()
devm_ioremap_wc() devm_ioremap_wc()
devm_ioremap_resource() : checks resource, requests memory region, ioremaps devm_ioremap_resource() : checks resource, requests memory region, ioremaps

16
Documentation/firmware-guide/acpi/enumeration.rst
View File

@@ -71,8 +71,8 @@ DMA support
DMA controllers enumerated via ACPI should be registered in the system to DMA controllers enumerated via ACPI should be registered in the system to
provide generic access to their resources. For example, a driver that would provide generic access to their resources. For example, a driver that would
like to be accessible to slave devices via generic API call like to be accessible to slave devices via generic API call
dma_request_slave_channel() must register itself at the end of the probe dma_request_chan() must register itself at the end of the probe function like
function like this:: this::
err = devm_acpi_dma_controller_register(dev, xlate_func, dw); err = devm_acpi_dma_controller_register(dev, xlate_func, dw);
/* Handle the error if it's not a case of !CONFIG_ACPI */ /* Handle the error if it's not a case of !CONFIG_ACPI */
@@ -112,15 +112,15 @@ could look like::
} }
#endif #endif
dma_request_slave_channel() will call xlate_func() for each registered DMA dma_request_chan() will call xlate_func() for each registered DMA controller.
controller. In the xlate function the proper channel must be chosen based on In the xlate function the proper channel must be chosen based on
information in struct acpi_dma_spec and the properties of the controller information in struct acpi_dma_spec and the properties of the controller
provided by struct acpi_dma. provided by struct acpi_dma.
Clients must call dma_request_slave_channel() with the string parameter that Clients must call dma_request_chan() with the string parameter that corresponds
corresponds to a specific FixedDMA resource. By default "tx" means the first to a specific FixedDMA resource. By default "tx" means the first entry of the
entry of the FixedDMA resource array, "rx" means the second entry. The table FixedDMA resource array, "rx" means the second entry. The table below shows a
below shows a layout:: layout::
Device (I2C0) Device (I2C0)
{ {

36
Documentation/hwmon/adm1177.rst Normal file
View File

@@ -0,0 +1,36 @@
Kernel driver adm1177
=====================
Supported chips:
* Analog Devices ADM1177
Prefix: 'adm1177'
Datasheet: https://www.analog.com/media/en/technical-documentation/data-sheets/ADM1177.pdf
Author: Beniamin Bia <beniamin.bia@analog.com>
Description
-----------
This driver supports hardware monitoring for Analog Devices ADM1177
Hot-Swap Controller and Digital Power Monitors with Soft Start Pin.
Usage Notes
-----------
This driver does not auto-detect devices. You will have to instantiate the
devices explicitly. Please see Documentation/i2c/instantiating-devices for
details.
Sysfs entries
-------------
The following attributes are supported. Current maxim attribute
is read-write, all other attributes are read-only.
in0_input Measured voltage in microvolts.
curr1_input Measured current in microamperes.
curr1_max_alarm Overcurrent alarm in microamperes.

52
Documentation/hwmon/drivetemp.rst Normal file
View File

@@ -0,0 +1,52 @@
.. SPDX-License-Identifier: GPL-2.0
Kernel driver drivetemp
=======================
References
----------
ANS T13/1699-D
Information technology - AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS)
ANS Project T10/BSR INCITS 513
Information technology - SCSI Primary Commands - 4 (SPC-4)
ANS Project INCITS 557
Information technology - SCSI / ATA Translation - 5 (SAT-5)
Description
-----------
This driver supports reporting the temperature of disk and solid state
drives with temperature sensors.
If supported, it uses the ATA SCT Command Transport feature to read
the current drive temperature and, if available, temperature limits
as well as historic minimum and maximum temperatures. If SCT Command
Transport is not supported, the driver uses SMART attributes to read
the drive temperature.
Sysfs entries
-------------
Only the temp1_input attribute is always available. Other attributes are
available only if reported by the drive. All temperatures are reported in
milli-degrees Celsius.
======================= =====================================================
temp1_input Current drive temperature
temp1_lcrit Minimum temperature limit. Operating the device below
this temperature may cause physical damage to the
device.
temp1_min Minimum recommended continuous operating limit
temp1_max Maximum recommended continuous operating temperature
temp1_crit Maximum temperature limit. Operating the device above
this temperature may cause physical damage to the
device.
temp1_lowest Minimum temperature seen this power cycle
temp1_highest Maximum temperature seen this power cycle
======================= =====================================================

5
Documentation/hwmon/index.rst
View File

@@ -29,6 +29,7 @@ Hardware Monitoring Kernel Drivers
adm1025 adm1025
adm1026 adm1026
adm1031 adm1031
adm1177
adm1275 adm1275
adm9240 adm9240
ads7828 ads7828
@@ -47,6 +48,7 @@ Hardware Monitoring Kernel Drivers
da9055 da9055
dell-smm-hwmon dell-smm-hwmon
dme1737 dme1737
drivetemp
ds1621 ds1621
ds620 ds620
emc1403 emc1403
@@ -106,8 +108,10 @@ Hardware Monitoring Kernel Drivers
max1619 max1619
max1668 max1668
max197 max197
max20730
max20751 max20751
max31722 max31722
max31730
max31785 max31785
max31790 max31790
max34440 max34440
@@ -177,6 +181,7 @@ Hardware Monitoring Kernel Drivers
wm831x wm831x
wm8350 wm8350
xgene-hwmon xgene-hwmon
xdpe12284
zl6100 zl6100
.. only:: subproject and html .. only:: subproject and html

74
Documentation/hwmon/max20730.rst Normal file
View File

@@ -0,0 +1,74 @@
.. SPDX-License-Identifier: GPL-2.0-or-later
Kernel driver max20730
======================
Supported chips:
* Maxim MAX20730
Prefix: 'max20730'
Addresses scanned: -
Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX20730.pdf
* Maxim MAX20734
Prefix: 'max20734'
Addresses scanned: -
Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX20734.pdf
* Maxim MAX20743
Prefix: 'max20743'
Addresses scanned: -
Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX20743.pdf
Author: Guenter Roeck <linux@roeck-us.net>
Description
-----------
This driver implements support for Maxim MAX20730, MAX20734, and MAX20743
Integrated, Step-Down Switching Regulators with PMBus support.
The driver is a client driver to the core PMBus driver.
Please see Documentation/hwmon/pmbus.rst for details on PMBus client drivers.
Usage Notes
-----------
This driver does not auto-detect devices. You will have to instantiate the
devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
details.
Sysfs entries
-------------
=================== ===== =======================================================
curr1_crit RW/RO Critical output current. Please see datasheet for
supported limits. Read-only if the chip is
write protected; read-write otherwise.
curr1_crit_alarm RO Output current critical alarm
curr1_input RO Output current
curr1_label RO 'iout1'
in1_alarm RO Input voltage alarm
in1_input RO Input voltage
in1_label RO 'vin'
in2_alarm RO Output voltage alarm
in2_input RO Output voltage
in2_label RO 'vout1'
temp1_crit RW/RO Critical temeperature. Supported values are 130 or 150
degrees C. Read-only if the chip is write protected;
read-write otherwise.
temp1_crit_alarm RO Temperature critical alarm
temp1_input RO Chip temperature
=================== ===== =======================================================

44
Documentation/hwmon/max31730.rst Normal file
View File

@@ -0,0 +1,44 @@
Kernel driver max31790
======================
Supported chips:
* Maxim MAX31730
Prefix: 'max31730'
Addresses scanned: 0x1c, 0x1d, 0x1e, 0x1f, 0x4c, 0x4d, 0x4e, 0x4f
Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX31730.pdf
Author: Guenter Roeck <linux@roeck-us.net>
Description
-----------
This driver implements support for Maxim MAX31730.
The MAX31730 temperature sensor monitors its own temperature and the
temperatures of three external diode-connected transistors. The operating
supply voltage is from 3.0V to 3.6V. Resistance cancellation compensates
for high series resistance in circuit-board traces and the external thermal
diode, while beta compensation corrects for temperature-measurement
errors due to low-beta sensing transistors.
Sysfs entries
-------------
=================== == =======================================================
temp[1-4]_enable RW Temperature enable/disable
Set to 0 to enable channel, 0 to disable
temp[1-4]_input RO Temperature input
temp[2-4]_fault RO Fault indicator for remote channels
temp[1-4]_max RW Maximum temperature
temp[1-4]_max_alarm RW Maximum temperature alarm
temp[1-4]_min RW Minimum temperature. Common for all channels.
Only temp1_min is writeable.
temp[1-4]_min_alarm RO Minimum temperature alarm
temp[2-4]_offset RW Temperature offset for remote channels
=================== == =======================================================

10
Documentation/hwmon/pmbus.rst
View File

@@ -63,6 +63,16 @@ Supported chips:
http://www.ti.com/lit/gpn/tps544c25 http://www.ti.com/lit/gpn/tps544c25
* Maxim MAX20796
Prefix: 'max20796'
Addresses scanned: -
Datasheet:
Not published
* Generic PMBus devices * Generic PMBus devices
Prefix: 'pmbus' Prefix: 'pmbus'

12
Documentation/hwmon/ucd9000.rst
View File

@@ -3,9 +3,10 @@ Kernel driver ucd9000
Supported chips: Supported chips:
* TI UCD90120, UCD90124, UCD90160, UCD9090, and UCD90910 * TI UCD90120, UCD90124, UCD90160, UCD90320, UCD9090, and UCD90910
Prefixes: 'ucd90120', 'ucd90124', 'ucd90160', 'ucd9090', 'ucd90910' Prefixes: 'ucd90120', 'ucd90124', 'ucd90160', 'ucd90320', 'ucd9090',
'ucd90910'
Addresses scanned: - Addresses scanned: -
@@ -14,6 +15,7 @@ Supported chips:
- http://focus.ti.com/lit/ds/symlink/ucd90120.pdf - http://focus.ti.com/lit/ds/symlink/ucd90120.pdf
- http://focus.ti.com/lit/ds/symlink/ucd90124.pdf - http://focus.ti.com/lit/ds/symlink/ucd90124.pdf
- http://focus.ti.com/lit/ds/symlink/ucd90160.pdf - http://focus.ti.com/lit/ds/symlink/ucd90160.pdf
- http://focus.ti.com/lit/ds/symlink/ucd90320.pdf
- http://focus.ti.com/lit/ds/symlink/ucd9090.pdf - http://focus.ti.com/lit/ds/symlink/ucd9090.pdf
- http://focus.ti.com/lit/ds/symlink/ucd90910.pdf - http://focus.ti.com/lit/ds/symlink/ucd90910.pdf
@@ -45,6 +47,12 @@ power-on reset signals, external interrupts, cascading, or other system
functions. Twelve of these pins offer PWM functionality. Using these pins, the functions. Twelve of these pins offer PWM functionality. Using these pins, the
UCD90160 offers support for margining, and general-purpose PWM functions. UCD90160 offers support for margining, and general-purpose PWM functions.
The UCD90320 is a 32-rail PMBus/I2C addressable power-supply sequencer and
monitor. The 24 integrated ADC channels (AMONx) monitor the power supply
voltage, current, and temperature. Of the 84 GPIO pins, 8 can be used as
digital monitors (DMONx), 32 to enable the power supply (ENx), 24 for margining
(MARx), 16 for logical GPO, and 32 GPIs for cascading, and system function.
The UCD9090 is a 10-rail PMBus/I2C addressable power-supply sequencer and The UCD9090 is a 10-rail PMBus/I2C addressable power-supply sequencer and
monitor. The device integrates a 12-bit ADC for monitoring up to 10 power-supply monitor. The device integrates a 12-bit ADC for monitoring up to 10 power-supply
voltage inputs. Twenty-three GPIO pins can be used for power supply enables, voltage inputs. Twenty-three GPIO pins can be used for power supply enables,

101
Documentation/hwmon/xdpe12284.rst Normal file
View File

@@ -0,0 +1,101 @@
.. SPDX-License-Identifier: GPL-2.0
Kernel driver xdpe122
=====================
Supported chips:
* Infineon XDPE12254
Prefix: 'xdpe12254'
* Infineon XDPE12284
Prefix: 'xdpe12284'
Authors:
Vadim Pasternak <vadimp@mellanox.com>
Description
-----------
This driver implements support for Infineon Multi-phase XDPE122 family
dual loop voltage regulators.
The family includes XDPE12284 and XDPE12254 devices.
The devices from this family complaint with:
- Intel VR13 and VR13HC rev 1.3, IMVP8 rev 1.2 and IMPVP9 rev 1.3 DC-DC
converter specification.
- Intel SVID rev 1.9. protocol.
- PMBus rev 1.3 interface.
Devices support linear format for reading input voltage, input and output current,
input and output power and temperature.
Device supports VID format for reading output voltage. The below modes are
supported:
- VR12.0 mode, 5-mV DAC - 0x01.
- VR12.5 mode, 10-mV DAC - 0x02.
- IMVP9 mode, 5-mV DAC - 0x03.
- AMD mode 6.25mV - 0x10.
Devices support two pages for telemetry.
The driver provides for current: input, maximum and critical thresholds
and maximum and critical alarms. Critical thresholds and critical alarm are
supported only for current output.
The driver exports the following attributes for via the sysfs files, where
indexes 1, 2 are for "iin" and 3, 4 for "iout":
**curr[3-4]_crit**
**curr[3-4]_crit_alarm**
**curr[1-4]_input**
**curr[1-4]_label**
**curr[1-4]_max**
**curr[1-4]_max_alarm**
The driver provides for voltage: input, critical and low critical thresholds
and critical and low critical alarms.
The driver exports the following attributes for via the sysfs files, where
indexes 1, 2 are for "vin" and 3, 4 for "vout":
**in[1-4]_crit**
**in[1-4_crit_alarm**
**in[1-4]_input**
**in[1-4_label**
**in[1-4]_lcrit**
**in[1-41_lcrit_alarm**
The driver provides for power: input and alarms. Power alarm is supported only
for power input.
The driver exports the following attributes for via the sysfs files, where
indexes 1, 2 are for "pin" and 3, 4 for "pout":
**power[1-2]_alarm**
**power[1-4]_input**
**power[1-4]_label**
The driver provides for temperature: input, maximum and critical thresholds
and maximum and critical alarms.
The driver exports the following attributes for via the sysfs files:
**temp[1-2]_crit**
**temp[1-2]_crit_alarm**
**temp[1-2]_input**
**temp[1-2]_max**
**temp[1-2]_max_alarm**

2
Documentation/sound/kernel-api/writing-an-alsa-driver.rst
View File

@@ -1058,7 +1058,7 @@ and the allocation would be like below:
return err; return err;
} }
chip->iobase_phys = pci_resource_start(pci, 0); chip->iobase_phys = pci_resource_start(pci, 0);
chip->iobase_virt = ioremap_nocache(chip->iobase_phys, chip->iobase_virt = ioremap(chip->iobase_phys,
pci_resource_len(pci, 0)); pci_resource_len(pci, 0));
and the corresponding destructor would be: and the corresponding destructor would be:

2
Documentation/x86/boot.rst
View File

@@ -251,7 +251,7 @@ setting fields in the header, you must make sure only to set fields
supported by the protocol version in use. supported by the protocol version in use.
Details of Harder Fileds Details of Header Fields
======================== ========================
For each field, some are information from the kernel to the bootloader For each field, some are information from the kernel to the bootloader

2
Documentation/x86/pat.rst
View File

@@ -44,8 +44,6 @@ address range to avoid any aliasing.
+------------------------+----------+--------------+------------------+ +------------------------+----------+--------------+------------------+
| ioremap_uc | -- | UC | UC | | ioremap_uc | -- | UC | UC |
+------------------------+----------+--------------+------------------+ +------------------------+----------+--------------+------------------+
| ioremap_nocache | -- | UC- | UC- |
+------------------------+----------+--------------+------------------+
| ioremap_wc | -- | -- | WC | | ioremap_wc | -- | -- | WC |
+------------------------+----------+--------------+------------------+ +------------------------+----------+--------------+------------------+
| ioremap_wt | -- | -- | WT | | ioremap_wt | -- | -- | WT |

73
MAINTAINERS
View File

@@ -345,7 +345,7 @@ F: drivers/acpi/apei/
ACPI COMPONENT ARCHITECTURE (ACPICA) ACPI COMPONENT ARCHITECTURE (ACPICA)
M: Robert Moore <robert.moore@intel.com> M: Robert Moore <robert.moore@intel.com>
M: Erik Schmauss <erik.schmauss@intel.com> M: Erik Kaneda <erik.kaneda@intel.com>
M: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> M: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
L: linux-acpi@vger.kernel.org L: linux-acpi@vger.kernel.org
L: devel@acpica.org L: devel@acpica.org
@@ -977,6 +977,15 @@ W: http://ez.analog.com/community/linux-device-drivers
F: drivers/iio/imu/adis16460.c F: drivers/iio/imu/adis16460.c
F: Documentation/devicetree/bindings/iio/imu/adi,adis16460.yaml F: Documentation/devicetree/bindings/iio/imu/adi,adis16460.yaml
ANALOG DEVICES INC ADM1177 DRIVER
M: Beniamin Bia <beniamin.bia@analog.com>
M: Michael Hennerich <Michael.Hennerich@analog.com>
L: linux-hwmon@vger.kernel.org
W: http://ez.analog.com/community/linux-device-drivers
S: Supported
F: drivers/hwmon/adm1177.c
F: Documentation/devicetree/bindings/hwmon/adi,adm1177.yaml
ANALOG DEVICES INC ADP5061 DRIVER ANALOG DEVICES INC ADP5061 DRIVER
M: Stefan Popa <stefan.popa@analog.com> M: Stefan Popa <stefan.popa@analog.com>
L: linux-pm@vger.kernel.org L: linux-pm@vger.kernel.org
@@ -2242,6 +2251,7 @@ L: linux-rockchip@lists.infradead.org
T: git git://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip.git T: git git://git.kernel.org/pub/scm/linux/kernel/git/mmind/linux-rockchip.git
S: Maintained S: Maintained
F: Documentation/devicetree/bindings/i2c/i2c-rk3x.txt F: Documentation/devicetree/bindings/i2c/i2c-rk3x.txt
F: Documentation/devicetree/bindings/mmc/rockchip-dw-mshc.yaml
F: arch/arm/boot/dts/rk3* F: arch/arm/boot/dts/rk3*
F: arch/arm/boot/dts/rv1108* F: arch/arm/boot/dts/rv1108*
F: arch/arm/mach-rockchip/ F: arch/arm/mach-rockchip/
@@ -2694,6 +2704,14 @@ S: Maintained
F: drivers/pinctrl/aspeed/ F: drivers/pinctrl/aspeed/
F: Documentation/devicetree/bindings/pinctrl/aspeed,* F: Documentation/devicetree/bindings/pinctrl/aspeed,*
ASPEED SCU INTERRUPT CONTROLLER DRIVER
M: Eddie James <eajames@linux.ibm.com>
L: linux-aspeed@lists.ozlabs.org (moderated for non-subscribers)
S: Maintained
F: Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2xxx-scu-ic.txt
F: drivers/irqchip/irq-aspeed-scu-ic.c
F: include/dt-bindings/interrupt-controller/aspeed-scu-ic.h
ASPEED VIDEO ENGINE DRIVER ASPEED VIDEO ENGINE DRIVER
M: Eddie James <eajames@linux.ibm.com> M: Eddie James <eajames@linux.ibm.com>
L: linux-media@vger.kernel.org L: linux-media@vger.kernel.org
@@ -7499,6 +7517,12 @@ S: Supported
F: drivers/scsi/hisi_sas/ F: drivers/scsi/hisi_sas/
F: Documentation/devicetree/bindings/scsi/hisilicon-sas.txt F: Documentation/devicetree/bindings/scsi/hisilicon-sas.txt
HISILICON V3XX SPI NOR FLASH Controller Driver
M: John Garry <john.garry@huawei.com>
W: http://www.hisilicon.com
S: Maintained
F: drivers/spi/spi-hisi-sfc-v3xx.c
HISILICON QM AND ZIP Controller DRIVER HISILICON QM AND ZIP Controller DRIVER
M: Zhou Wang <wangzhou1@hisilicon.com> M: Zhou Wang <wangzhou1@hisilicon.com>
L: linux-crypto@vger.kernel.org L: linux-crypto@vger.kernel.org
@@ -7842,10 +7866,10 @@ F: Documentation/devicetree/bindings/i3c/snps,dw-i3c-master.txt
F: drivers/i3c/master/dw* F: drivers/i3c/master/dw*
I3C DRIVER FOR CADENCE I3C MASTER IP I3C DRIVER FOR CADENCE I3C MASTER IP
M: Przemysław Gaj <pgaj@cadence.com> M: Przemysław Gaj <pgaj@cadence.com>
S: Maintained S: Maintained
F: Documentation/devicetree/bindings/i3c/cdns,i3c-master.txt F: Documentation/devicetree/bindings/i3c/cdns,i3c-master.txt
F: drivers/i3c/master/i3c-master-cdns.c F: drivers/i3c/master/i3c-master-cdns.c
IA64 (Itanium) PLATFORM IA64 (Itanium) PLATFORM
M: Tony Luck <tony.luck@intel.com> M: Tony Luck <tony.luck@intel.com>
@@ -8382,6 +8406,14 @@ Q: https://patchwork.kernel.org/project/linux-dmaengine/list/
S: Supported S: Supported
F: drivers/dma/ioat* F: drivers/dma/ioat*
INTEL IADX DRIVER
M: Dave Jiang <dave.jiang@intel.com>
L: dmaengine@vger.kernel.org
S: Supported
F: drivers/dma/idxd/*
F: include/uapi/linux/idxd.h
F: include/linux/idxd.h
INTEL IDLE DRIVER INTEL IDLE DRIVER
M: Jacob Pan <jacob.jun.pan@linux.intel.com> M: Jacob Pan <jacob.jun.pan@linux.intel.com>
M: Len Brown <lenb@kernel.org> M: Len Brown <lenb@kernel.org>
@@ -8563,6 +8595,12 @@ S: Maintained
F: arch/x86/include/asm/intel_telemetry.h F: arch/x86/include/asm/intel_telemetry.h
F: drivers/platform/x86/intel_telemetry* F: drivers/platform/x86/intel_telemetry*
INTEL UNCORE FREQUENCY CONTROL
M: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
L: platform-driver-x86@vger.kernel.org
S: Maintained
F: drivers/platform/x86/intel-uncore-frequency.c
INTEL VIRTUAL BUTTON DRIVER INTEL VIRTUAL BUTTON DRIVER
M: AceLan Kao <acelan.kao@canonical.com> M: AceLan Kao <acelan.kao@canonical.com>
L: platform-driver-x86@vger.kernel.org L: platform-driver-x86@vger.kernel.org
@@ -9133,7 +9171,7 @@ F: arch/x86/include/uapi/asm/svm.h
F: arch/x86/include/asm/kvm* F: arch/x86/include/asm/kvm*
F: arch/x86/include/asm/pvclock-abi.h F: arch/x86/include/asm/pvclock-abi.h
F: arch/x86/include/asm/svm.h F: arch/x86/include/asm/svm.h
F: arch/x86/include/asm/vmx.h F: arch/x86/include/asm/vmx*.h
F: arch/x86/kernel/kvm.c F: arch/x86/kernel/kvm.c
F: arch/x86/kernel/kvmclock.c F: arch/x86/kernel/kvmclock.c
@@ -11144,6 +11182,13 @@ S: Maintained
F: Documentation/driver-api/serial/moxa-smartio.rst F: Documentation/driver-api/serial/moxa-smartio.rst
F: drivers/tty/mxser.* F: drivers/tty/mxser.*
MONOLITHIC POWER SYSTEM PMIC DRIVER
M: Saravanan Sekar <sravanhome@gmail.com>
S: Maintained
F: Documentation/devicetree/bindings/regulator/mpq7920.yaml
F: drivers/regulator/mpq7920.c
F: drivers/regulator/mpq7920.h
MR800 AVERMEDIA USB FM RADIO DRIVER MR800 AVERMEDIA USB FM RADIO DRIVER
M: Alexey Klimov <klimov.linux@gmail.com> M: Alexey Klimov <klimov.linux@gmail.com>
L: linux-media@vger.kernel.org L: linux-media@vger.kernel.org
@@ -13146,6 +13191,11 @@ S: Maintained
F: drivers/iio/chemical/pms7003.c F: drivers/iio/chemical/pms7003.c
F: Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.yaml F: Documentation/devicetree/bindings/iio/chemical/plantower,pms7003.yaml
PLX DMA DRIVER
M: Logan Gunthorpe <logang@deltatee.com>
S: Maintained
F: drivers/dma/plx_dma.c
PMBUS HARDWARE MONITORING DRIVERS PMBUS HARDWARE MONITORING DRIVERS
M: Guenter Roeck <linux@roeck-us.net> M: Guenter Roeck <linux@roeck-us.net>
L: linux-hwmon@vger.kernel.org L: linux-hwmon@vger.kernel.org
@@ -13216,6 +13266,8 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers/core
S: Maintained S: Maintained
F: fs/timerfd.c F: fs/timerfd.c
F: include/linux/timer* F: include/linux/timer*
F: include/linux/time_namespace.h
F: kernel/time_namespace.c
F: kernel/time/*timer* F: kernel/time/*timer*
POWER MANAGEMENT CORE POWER MANAGEMENT CORE
@@ -13673,6 +13725,14 @@ S: Maintained
F: Documentation/devicetree/bindings/opp/qcom-nvmem-cpufreq.txt F: Documentation/devicetree/bindings/opp/qcom-nvmem-cpufreq.txt
F: drivers/cpufreq/qcom-cpufreq-nvmem.c F: drivers/cpufreq/qcom-cpufreq-nvmem.c
QUALCOMM CORE POWER REDUCTION (CPR) AVS DRIVER
M: Niklas Cassel <nks@flawful.org>
L: linux-pm@vger.kernel.org
L: linux-arm-msm@vger.kernel.org
S: Maintained
F: Documentation/devicetree/bindings/power/avs/qcom,cpr.txt
F: drivers/power/avs/qcom-cpr.c
QUALCOMM EMAC GIGABIT ETHERNET DRIVER QUALCOMM EMAC GIGABIT ETHERNET DRIVER
M: Timur Tabi <timur@kernel.org> M: Timur Tabi <timur@kernel.org>
L: netdev@vger.kernel.org L: netdev@vger.kernel.org
@@ -14820,6 +14880,7 @@ F: include/uapi/linux/selinux_netlink.h
F: security/selinux/ F: security/selinux/
F: scripts/selinux/ F: scripts/selinux/
F: Documentation/admin-guide/LSM/SELinux.rst F: Documentation/admin-guide/LSM/SELinux.rst
F: Documentation/ABI/obsolete/sysfs-selinux-disable
SENSABLE PHANTOM SENSABLE PHANTOM
M: Jiri Slaby <jirislaby@gmail.com> M: Jiri Slaby <jirislaby@gmail.com>

10
arch/alpha/include/asm/io.h
View File

@@ -283,14 +283,8 @@ static inline void __iomem *ioremap(unsigned long port, unsigned long size)
return IO_CONCAT(__IO_PREFIX,ioremap) (port, size); return IO_CONCAT(__IO_PREFIX,ioremap) (port, size);
} }
static inline void __iomem * ioremap_nocache(unsigned long offset, #define ioremap_wc ioremap
unsigned long size) #define ioremap_uc ioremap
{
return ioremap(offset, size);
}
#define ioremap_wc ioremap_nocache
#define ioremap_uc ioremap_nocache
static inline void iounmap(volatile void __iomem *addr) static inline void iounmap(volatile void __iomem *addr)
{ {

4
arch/alpha/include/asm/vmalloc.h Normal file
View File

@@ -0,0 +1,4 @@
#ifndef _ASM_ALPHA_VMALLOC_H
#define _ASM_ALPHA_VMALLOC_H
#endif /* _ASM_ALPHA_VMALLOC_H */

2
arch/arc/Kconfig
View File

@@ -13,7 +13,7 @@ config ARC
select ARCH_HAS_SYNC_DMA_FOR_DEVICE select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select ARCH_SUPPORTS_ATOMIC_RMW if ARC_HAS_LLSC select ARCH_SUPPORTS_ATOMIC_RMW if ARC_HAS_LLSC
select ARCH_32BIT_OFF_T select ARCH_32BIT_OFF_T
select BUILDTIME_EXTABLE_SORT select BUILDTIME_TABLE_SORT
select CLONE_BACKWARDS select CLONE_BACKWARDS
select COMMON_CLK select COMMON_CLK
select DMA_DIRECT_REMAP select DMA_DIRECT_REMAP

4
arch/arc/include/asm/vmalloc.h Normal file
View File

@@ -0,0 +1,4 @@
#ifndef _ASM_ARC_VMALLOC_H
#define _ASM_ARC_VMALLOC_H
#endif /* _ASM_ARC_VMALLOC_H */

6
arch/arc/kernel/entry.S
View File

@@ -337,11 +337,11 @@ resume_user_mode_begin:
resume_kernel_mode: resume_kernel_mode:
; Disable Interrupts from this point on ; Disable Interrupts from this point on
; CONFIG_PREEMPT: This is a must for preempt_schedule_irq() ; CONFIG_PREEMPTION: This is a must for preempt_schedule_irq()
; !CONFIG_PREEMPT: To ensure restore_regs is intr safe ; !CONFIG_PREEMPTION: To ensure restore_regs is intr safe
IRQ_DISABLE r9 IRQ_DISABLE r9
#ifdef CONFIG_PREEMPT #ifdef CONFIG_PREEMPTION
; Can't preempt if preemption disabled ; Can't preempt if preemption disabled
GET_CURR_THR_INFO_FROM_SP r10 GET_CURR_THR_INFO_FROM_SP r10

2
arch/arm/Kconfig
View File

@@ -36,7 +36,7 @@ config ARM
select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
select ARCH_WANT_IPC_PARSE_VERSION select ARCH_WANT_IPC_PARSE_VERSION
select BINFMT_FLAT_ARGVP_ENVP_ON_STACK select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
select BUILDTIME_EXTABLE_SORT if MMU select BUILDTIME_TABLE_SORT if MMU
select CLONE_BACKWARDS select CLONE_BACKWARDS
select CPU_PM if SUSPEND || CPU_IDLE select CPU_PM if SUSPEND || CPU_IDLE
select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS select DCACHE_WORD_ACCESS if HAVE_EFFICIENT_UNALIGNED_ACCESS

2
arch/arm/include/asm/arch_gicv3.h
View File

@@ -10,6 +10,7 @@
#ifndef __ASSEMBLY__ #ifndef __ASSEMBLY__
#include <linux/io.h> #include <linux/io.h>
#include <linux/io-64-nonatomic-lo-hi.h>
#include <asm/barrier.h> #include <asm/barrier.h>
#include <asm/cacheflush.h> #include <asm/cacheflush.h>
#include <asm/cp15.h> #include <asm/cp15.h>
@@ -327,6 +328,7 @@ static inline u64 __gic_readq_nonatomic(const volatile void __iomem *addr)
/* /*
* GITS_VPROPBASER - hi and lo bits may be accessed independently. * GITS_VPROPBASER - hi and lo bits may be accessed independently.
*/ */
#define gits_read_vpropbaser(c) __gic_readq_nonatomic(c)
#define gits_write_vpropbaser(v, c) __gic_writeq_nonatomic(v, c) #define gits_write_vpropbaser(v, c) __gic_writeq_nonatomic(v, c)
/* /*

17
arch/arm/include/asm/efi.h
View File

@@ -50,19 +50,16 @@ void efi_virtmap_unload(void);
/* arch specific definitions used by the stub code */ /* arch specific definitions used by the stub code */
#define efi_call_early(f, ...) sys_table_arg->boottime->f(__VA_ARGS__) #define efi_bs_call(func, ...) efi_system_table()->boottime->func(__VA_ARGS__)
#define __efi_call_early(f, ...) f(__VA_ARGS__) #define efi_rt_call(func, ...) efi_system_table()->runtime->func(__VA_ARGS__)
#define efi_call_runtime(f, ...) sys_table_arg->runtime->f(__VA_ARGS__) #define efi_is_native() (true)
#define efi_is_64bit() (false)
#define efi_table_attr(table, attr, instance) \ #define efi_table_attr(inst, attr) (inst->attr)
((table##_t *)instance)->attr
#define efi_call_proto(protocol, f, instance, ...) \ #define efi_call_proto(inst, func, ...) inst->func(inst, ##__VA_ARGS__)
((protocol##_t *)instance)->f(instance, ##__VA_ARGS__)
struct screen_info *alloc_screen_info(efi_system_table_t *sys_table_arg); struct screen_info *alloc_screen_info(void);
void free_screen_info(efi_system_table_t *sys_table, struct screen_info *si); void free_screen_info(struct screen_info *si);
static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt) static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt)
{ {

8
arch/arm/include/asm/io.h
View File

@@ -356,7 +356,6 @@ static inline void memcpy_toio(volatile void __iomem *to, const void *from,
* *
* Function Memory type Cacheability Cache hint * Function Memory type Cacheability Cache hint
* ioremap() Device n/a n/a * ioremap() Device n/a n/a
* ioremap_nocache() Device n/a n/a
* ioremap_cache() Normal Writeback Read allocate * ioremap_cache() Normal Writeback Read allocate
* ioremap_wc() Normal Non-cacheable n/a * ioremap_wc() Normal Non-cacheable n/a
* ioremap_wt() Normal Non-cacheable n/a * ioremap_wt() Normal Non-cacheable n/a
@@ -368,13 +367,6 @@ static inline void memcpy_toio(volatile void __iomem *to, const void *from,
* - unaligned accesses are "unpredictable" * - unaligned accesses are "unpredictable"
* - writes may be delayed before they hit the endpoint device * - writes may be delayed before they hit the endpoint device
* *
* ioremap_nocache() is the same as ioremap() as there are too many device
* drivers using this for device registers, and documentation which tells
* people to use it for such for this to be any different. This is not a
* safe fallback for memory-like mappings, or memory regions where the
* compiler may generate unaligned accesses - eg, via inlining its own
* memcpy.
*
* All normal memory mappings have the following properties: * All normal memory mappings have the following properties:
* - reads can be repeated with no side effects * - reads can be repeated with no side effects
* - repeated reads return the last value written * - repeated reads return the last value written

2
arch/arm/include/asm/switch_to.h
View File

@@ -10,7 +10,7 @@
* to ensure that the maintenance completes in case we migrate to another * to ensure that the maintenance completes in case we migrate to another
* CPU. * CPU.
*/ */
#if defined(CONFIG_PREEMPT) && defined(CONFIG_SMP) && defined(CONFIG_CPU_V7) #if defined(CONFIG_PREEMPTION) && defined(CONFIG_SMP) && defined(CONFIG_CPU_V7)
#define __complete_pending_tlbi() dsb(ish) #define __complete_pending_tlbi() dsb(ish)
#else #else
#define __complete_pending_tlbi() #define __complete_pending_tlbi()

36
arch/arm/include/asm/vdso/gettimeofday.h
View File

@@ -52,6 +52,24 @@ static __always_inline long clock_gettime_fallback(
return ret; return ret;
} }
static __always_inline long clock_gettime32_fallback(
clockid_t _clkid,
struct old_timespec32 *_ts)
{
register struct old_timespec32 *ts asm("r1") = _ts;
register clockid_t clkid asm("r0") = _clkid;
register long ret asm ("r0");
register long nr asm("r7") = __NR_clock_gettime;
asm volatile(
" swi #0\n"
: "=r" (ret)
: "r" (clkid), "r" (ts), "r" (nr)
: "memory");
return ret;
}
static __always_inline int clock_getres_fallback( static __always_inline int clock_getres_fallback(
clockid_t _clkid, clockid_t _clkid,
struct __kernel_timespec *_ts) struct __kernel_timespec *_ts)
@@ -70,6 +88,24 @@ static __always_inline int clock_getres_fallback(
return ret; return ret;
} }
static __always_inline int clock_getres32_fallback(
clockid_t _clkid,
struct old_timespec32 *_ts)
{
register struct old_timespec32 *ts asm("r1") = _ts;
register clockid_t clkid asm("r0") = _clkid;
register long ret asm ("r0");
register long nr asm("r7") = __NR_clock_getres;
asm volatile(
" swi #0\n"
: "=r" (ret)
: "r" (clkid), "r" (ts), "r" (nr)
: "memory");
return ret;
}
static __always_inline u64 __arch_get_hw_counter(int clock_mode) static __always_inline u64 __arch_get_hw_counter(int clock_mode)
{ {
#ifdef CONFIG_ARM_ARCH_TIMER #ifdef CONFIG_ARM_ARCH_TIMER

4
arch/arm/include/asm/vdso/vsyscall.h
View File

@@ -34,9 +34,9 @@ struct vdso_data *__arm_get_k_vdso_data(void)
#define __arch_get_k_vdso_data __arm_get_k_vdso_data #define __arch_get_k_vdso_data __arm_get_k_vdso_data
static __always_inline static __always_inline
int __arm_update_vdso_data(void) bool __arm_update_vdso_data(void)
{ {
return !cntvct_ok; return cntvct_ok;
} }
#define __arch_update_vdso_data __arm_update_vdso_data #define __arch_update_vdso_data __arm_update_vdso_data

4
arch/arm/include/asm/vmalloc.h Normal file
View File

@@ -0,0 +1,4 @@
#ifndef _ASM_ARM_VMALLOC_H
#define _ASM_ARM_VMALLOC_H
#endif /* _ASM_ARM_VMALLOC_H */

4
arch/arm/kernel/Makefile
View File

@@ -53,8 +53,8 @@ obj-$(CONFIG_HAVE_ARM_SCU) += smp_scu.o
obj-$(CONFIG_HAVE_ARM_TWD) += smp_twd.o obj-$(CONFIG_HAVE_ARM_TWD) += smp_twd.o
obj-$(CONFIG_ARM_ARCH_TIMER) += arch_timer.o obj-$(CONFIG_ARM_ARCH_TIMER) += arch_timer.o
obj-$(CONFIG_FUNCTION_TRACER) += entry-ftrace.o obj-$(CONFIG_FUNCTION_TRACER) += entry-ftrace.o
obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o insn.o obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o insn.o patch.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o insn.o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o insn.o patch.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o insn.o patch.o obj-$(CONFIG_JUMP_LABEL) += jump_label.o insn.o patch.o
obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o obj-$(CONFIG_KEXEC) += machine_kexec.o relocate_kernel.o
# Main staffs in KPROBES are in arch/arm/probes/ . # Main staffs in KPROBES are in arch/arm/probes/ .

4
arch/arm/kernel/entry-armv.S
View File

@@ -211,7 +211,7 @@ __irq_svc:
svc_entry svc_entry
irq_handler irq_handler
#ifdef CONFIG_PREEMPT #ifdef CONFIG_PREEMPTION
ldr r8, [tsk, #TI_PREEMPT] @ get preempt count ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
ldr r0, [tsk, #TI_FLAGS] @ get flags ldr r0, [tsk, #TI_FLAGS] @ get flags
teq r8, #0 @ if preempt count != 0 teq r8, #0 @ if preempt count != 0
@@ -226,7 +226,7 @@ ENDPROC(__irq_svc)
.ltorg .ltorg
#ifdef CONFIG_PREEMPT #ifdef CONFIG_PREEMPTION
svc_preempt: svc_preempt:
mov r8, lr mov r8, lr
1: bl preempt_schedule_irq @ irq en/disable is done inside 1: bl preempt_schedule_irq @ irq en/disable is done inside

10
arch/arm/kernel/ftrace.c
View File

@@ -22,6 +22,7 @@
#include <asm/ftrace.h> #include <asm/ftrace.h>
#include <asm/insn.h> #include <asm/insn.h>
#include <asm/set_memory.h> #include <asm/set_memory.h>
#include <asm/patch.h>
#ifdef CONFIG_THUMB2_KERNEL #ifdef CONFIG_THUMB2_KERNEL
#define NOP 0xf85deb04 /* pop.w {lr} */ #define NOP 0xf85deb04 /* pop.w {lr} */
@@ -35,9 +36,7 @@ static int __ftrace_modify_code(void *data)
{ {
int *command = data; int *command = data;
set_kernel_text_rw();
ftrace_modify_all_code(*command); ftrace_modify_all_code(*command);
set_kernel_text_ro();
return 0; return 0;
} }
@@ -59,13 +58,11 @@ static unsigned long adjust_address(struct dyn_ftrace *rec, unsigned long addr)
int ftrace_arch_code_modify_prepare(void) int ftrace_arch_code_modify_prepare(void)
{ {
set_all_modules_text_rw();
return 0; return 0;
} }
int ftrace_arch_code_modify_post_process(void) int ftrace_arch_code_modify_post_process(void)
{ {
set_all_modules_text_ro();
/* Make sure any TLB misses during machine stop are cleared. */ /* Make sure any TLB misses during machine stop are cleared. */
flush_tlb_all(); flush_tlb_all();
return 0; return 0;
@@ -97,10 +94,7 @@ static int ftrace_modify_code(unsigned long pc, unsigned long old,
return -EINVAL; return -EINVAL;
} }
if (probe_kernel_write((void *)pc, &new, MCOUNT_INSN_SIZE)) __patch_text((void *)pc, new);
return -EPERM;
flush_icache_range(pc, pc + MCOUNT_INSN_SIZE);
return 0; return 0;
} }

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