The null check on clk->name is redundant since name is a char array
and can never be null, so the check is always true. Remove it.
Detected by CoverityScan, CID#1466117 ("Array compared against 0")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Pull dmi updates from Jean Delvare.
* 'dmi-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jdelvare/staging:
firmware: dmi_scan: Use lowercase letters for UUID
firmware: dmi_scan: Add DMI_OEM_STRING support to dmi_matches
firmware: dmi_scan: Fix UUID length safety check
OEM strings are defined by each OEM and they contain customized and
useful OEM information. Supporting it provides more flexible uses of
the dmi_matches function.
Signed-off-by: Alex Hung <alex.hung@canonical.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
The test which ensures that the DMI type 1 structure is long enough
to hold the UUID is off by one. It would fail if the structure is
exactly 24 bytes long, while that's sufficient to hold the UUID.
I don't expect this bug to cause problem in practice because all
implementations I have seen had length 8, 25 or 27 bytes, in line
with the SMBIOS specifications. But let's fix it still.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: a814c3597a ("firmware: dmi_scan: Check DMI structure length")
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Pull MIPS updates from James Hogan:
"These are the main MIPS changes for 4.17. Rough overview:
(1) generic platform: Add support for Microsemi Ocelot SoCs
(2) crypto: Add CRC32 and CRC32C HW acceleration module
(3) Various cleanups and misc improvements
More detailed summary:
Miscellaneous:
- hang more efficiently on halt/powerdown/restart
- pm-cps: Block system suspend when a JTAG probe is present
- expand make help text for generic defconfigs
- refactor handling of legacy defconfigs
- determine the entry point from the ELF file header to fix microMIPS
for certain toolchains
- introduce isa-rev.h for MIPS_ISA_REV and use to simplify other code
Minor cleanups:
- DTS: boston/ci20: Unit name cleanups and correction
- kdump: Make the default for PHYSICAL_START always 64-bit
- constify gpio_led in Alchemy, AR7, and TXX9
- silence a couple of W=1 warnings
- remove duplicate includes
Platform support:
Generic platform:
- add support for Microsemi Ocelot
- dt-bindings: Add vendor prefix for Microsemi Corporation
- dt-bindings: Add bindings for Microsemi SoCs
- add ocelot SoC & PCB123 board DTS files
- MAINTAINERS: Add entry for Microsemi MIPS SoCs
- enable crc32-mips on r6 configs
ath79:
- fix AR724X_PLL_REG_PCIE_CONFIG offset
BCM47xx:
- firmware: Use mac_pton() for MAC address parsing
- add Luxul XAP1500/XWR1750 WiFi LEDs
- use standard reset button for Luxul XWR-1750
BMIPS:
- enable CONFIG_BRCMSTB_PM in bmips_stb_defconfig for build coverage
- add STB PM, wake-up timer, watchdog DT nodes
Octeon:
- drop '.' after newlines in printk calls
ralink:
- pci-mt7621: Enable PCIe on MT7688"
* tag 'mips_4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/jhogan/mips: (37 commits)
MIPS: BCM47XX: Use standard reset button for Luxul XWR-1750
MIPS: BCM47XX: Add Luxul XAP1500/XWR1750 WiFi LEDs
MIPS: Make the default for PHYSICAL_START always 64-bit
MIPS: Use the entry point from the ELF file header
MAINTAINERS: Add entry for Microsemi MIPS SoCs
MIPS: generic: Add support for Microsemi Ocelot
MIPS: mscc: Add ocelot PCB123 device tree
MIPS: mscc: Add ocelot dtsi
dt-bindings: mips: Add bindings for Microsemi SoCs
dt-bindings: Add vendor prefix for Microsemi Corporation
MIPS: ath79: Fix AR724X_PLL_REG_PCIE_CONFIG offset
MIPS: pci-mt7620: Enable PCIe on MT7688
MIPS: pm-cps: Block system suspend when a JTAG probe is present
MIPS: VDSO: Replace __mips_isa_rev with MIPS_ISA_REV
MIPS: BPF: Replace __mips_isa_rev with MIPS_ISA_REV
MIPS: cpu-features.h: Replace __mips_isa_rev with MIPS_ISA_REV
MIPS: Introduce isa-rev.h to define MIPS_ISA_REV
MIPS: Hang more efficiently on halt/powerdown/restart
FIRMWARE: bcm47xx_nvram: Replace mac address parsing
MIPS: BMIPS: Add Broadcom STB watchdog nodes
...
Pull fw_cfg, vhost updates from Michael Tsirkin:
"This cleans up the qemu fw cfg device driver.
On top of this, vmcore is dumped there on crash to help debugging
with kASLR enabled.
Also included are some fixes in vhost"
* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
vhost: add vsock compat ioctl
vhost: fix vhost ioctl signature to build with clang
fw_cfg: write vmcoreinfo details
crash: export paddr_vmcoreinfo_note()
fw_cfg: add DMA register
fw_cfg: add a public uapi header
fw_cfg: handle fw_cfg_read_blob() error
fw_cfg: remove inline from fw_cfg_read_blob()
fw_cfg: fix sparse warnings around FW_CFG_FILE_DIR read
fw_cfg: fix sparse warning reading FW_CFG_ID
fw_cfg: fix sparse warnings with fw_cfg_file
fw_cfg: fix sparse warnings in fw_cfg_sel_endianness()
ptr_ring: fix build
Pull ARM SoC driver updates from Arnd Bergmann:
"The main addition this time around is the new ARM "SCMI" framework,
which is the latest in a series of standards coming from ARM to do
power management in a platform independent way.
This has been through many review cycles, and it relies on a rather
interesting way of using the mailbox subsystem, but in the end I
agreed that Sudeep's version was the best we could do after all.
Other changes include:
- the ARM CCN driver is moved out of drivers/bus into drivers/perf,
which makes more sense. Similarly, the performance monitoring
portion of the CCI driver are moved the same way and cleaned up a
little more.
- a series of updates to the SCPI framework
- support for the Mediatek mt7623a SoC in drivers/soc
- support for additional NVIDIA Tegra hardware in drivers/soc
- a new reset driver for Socionext Uniphier
- lesser bug fixes in drivers/soc, drivers/tee, drivers/memory, and
drivers/firmware and drivers/reset across platforms"
* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (87 commits)
reset: uniphier: add ethernet reset control support for PXs3
reset: stm32mp1: Enable stm32mp1 reset driver
dt-bindings: reset: add STM32MP1 resets
reset: uniphier: add Pro4/Pro5/PXs2 audio systems reset control
reset: imx7: add 'depends on HAS_IOMEM' to fix unmet dependency
reset: modify the way reset lookup works for board files
reset: add support for non-DT systems
clk: scmi: use devm_of_clk_add_hw_provider() API and drop scmi_clocks_remove
firmware: arm_scmi: prevent accessing rate_discrete uninitialized
hwmon: (scmi) return -EINVAL when sensor information is unavailable
amlogic: meson-gx-socinfo: Update soc ids
soc/tegra: pmc: Use the new reset APIs to manage reset controllers
soc: mediatek: update power domain data of MT2712
dt-bindings: soc: update MT2712 power dt-bindings
cpufreq: scmi: add thermal dependency
soc: mediatek: fix the mistaken pointer accessed when subdomains are added
soc: mediatek: add SCPSYS power domain driver for MediaTek MT7623A SoC
soc: mediatek: avoid hardcoded value with bus_prot_mask
dt-bindings: soc: add header files required for MT7623A SCPSYS dt-binding
dt-bindings: soc: add SCPSYS binding for MT7623 and MT7623A SoC
...
Pull EDAC updates from Borislav Petkov:
"Noteworthy is the NVDIMM support:
- NVDIMM support to EDAC (Tony Luck)
- misc fixes"
* tag 'edac_for_4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp:
EDAC, sb_edac: Remove variable length array usage
EDAC, skx_edac: Detect non-volatile DIMMs
firmware, DMI: Add function to look up a handle and return DIMM size
acpi, nfit: Add function to look up nvdimm device and provide SMBIOS handle
EDAC: Add new memory type for non-volatile DIMMs
EDAC: Drop duplicated array of strings for memory type names
EDAC, layerscape: Allow building for LS1021A
Pull trivial tree updates from Jiri Kosina.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial:
kfifo: fix inaccurate comment
tools/thermal: tmon: fix for segfault
net: Spelling s/stucture/structure/
edd: don't spam log if no EDD information is present
Documentation: Fix early-microcode.txt references after file rename
tracing: Block comments should align the * on each line
treewide: Fix typos in printk
GenWQE: Fix a typo in two comments
treewide: Align function definition open/close braces
Pull EFI updates from Ingo Molnar:
"The main EFI changes in this cycle were:
- Fix the apple-properties code (Andy Shevchenko)
- Add WARN() on arm64 if UEFI Runtime Services corrupt the reserved
x18 register (Ard Biesheuvel)
- Use efi_switch_mm() on x86 instead of manipulating %cr3 directly
(Sai Praneeth)
- Fix early memremap leak in ESRT code (Ard Biesheuvel)
- Switch to L"xxx" notation for wide string literals (Ard Biesheuvel)
- ... plus misc other cleanups and bugfixes"
* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/efi: Use efi_switch_mm() rather than manually twiddling with %cr3
x86/efi: Replace efi_pgd with efi_mm.pgd
efi: Use string literals for efi_char16_t variable initializers
efi/esrt: Fix handling of early ESRT table mapping
efi: Use efi_mm in x86 as well as ARM
efi: Make const array 'apple' static
efi/apple-properties: Use memremap() instead of ioremap()
efi: Reorder pr_notice() with add_device_randomness() call
x86/efi: Replace GFP_ATOMIC with GFP_KERNEL in efi_query_variable_store()
efi/arm64: Check whether x18 is preserved by runtime services calls
efi/arm*: Stop printing addresses of virtual mappings
efi/apple-properties: Remove redundant attribute initialization from unmarshal_key_value_pairs()
efi/arm*: Only register page tables when they exist
Pull x86 platform updates from Ingo Molnar:
"The main changes in this cycle were:
- Add "Jailhouse" hypervisor support (Jan Kiszka)
- Update DeviceTree support (Ivan Gorinov)
- Improve DMI date handling (Andy Shevchenko)"
* 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/PCI: Fix a potential regression when using dmi_get_bios_year()
firmware/dmi_scan: Uninline dmi_get_bios_year() helper
x86/devicetree: Use CPU description from Device Tree
of/Documentation: Specify local APIC ID in "reg"
MAINTAINERS: Add entry for Jailhouse
x86/jailhouse: Allow to use PCI_MMCONFIG without ACPI
x86: Consolidate PCI_MMCONFIG configs
x86: Align x86_64 PCI_MMCONFIG with 32-bit variant
x86/jailhouse: Enable PCI mmconfig access in inmates
PCI: Scan all functions when running over Jailhouse
jailhouse: Provide detection for non-x86 systems
x86/devicetree: Fix device IRQ settings in DT
x86/devicetree: Initialize device tree before using it
pci: Simplify code by using the new dmi_get_bios_year() helper
ACPI/sleep: Simplify code by using the new dmi_get_bios_year() helper
x86/pci: Simplify code by using the new dmi_get_bios_year() helper
dmi: Introduce the dmi_get_bios_year() helper function
x86/platform/quark: Re-use DEFINE_SHOW_ATTRIBUTE() macro
x86/platform/atom: Re-use DEFINE_SHOW_ATTRIBUTE() macro
Pull "ARM SCMI fixes/cleanups for v4.17" from Sudeep Holla:
Couple of fixes for build warning due to uninitialised variable
and static checker warning for passing NULL pointer to PTR_ERR.
It also contains cleanup suggested by Stephen Boyd in SCMI clock
driver using the new devm_of_clk_add_hw_provider() API.
* tag 'scmi-fixes-4.17' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
clk: scmi: use devm_of_clk_add_hw_provider() API and drop scmi_clocks_remove
firmware: arm_scmi: prevent accessing rate_discrete uninitialized
hwmon: (scmi) return -EINVAL when sensor information is unavailable
Pull "Amlogic driver updates for v4.17" from Kevin Hilman:
- socinfo: add more IDs for newer SoC detection
- firmware: update init to use module_platform_driver_probe
- soc: mix. VPU power controller fixes
* tag 'amlogic-drivers' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/khilman/linux-amlogic:
amlogic: meson-gx-socinfo: Update soc ids
firmware: meson-sm: rework meson_sm_init to use module_platform_driver_probe
meson-gx-socinfo: make local function meson_gx_socinfo_init static
meson-mx-socinfo: Make local function meson_mx_socinfo_init() static
soc: amlogic: meson-gx-pwrc-vpu: fix error on shutdown when domain is powered off
soc: amlogic: meson-gx-pwrc-vpu: don't print error message on probe deferral
Pull "firmware: Changes for v4.17-rc1" from Thierry Reding:
These changes are rather small, with just a fix for a return value check
and some preparatory work for Tegra194 BPMP support.
* tag 'tegra-for-4.17-firmware' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
firmware: tegra: adjust tested variable
firmware: tegra: Simplify channel management
We've had reports from users being concerned about messages like:
[ 4.487246] BIOS EDD facility v0.16 2004-Jun-25, 0 devices found
[ 4.487251] EDD information not available.
While these are more or less irrelevant, tell edd.c to not annoy anyone.
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
gcc-5.3 and earlier warns that rate_discrete maybe-uninitialized
../drivers/firmware/arm_scmi/clock.c:185:5: warning: 'rate_discrete'
may be used uninitialized in this function [-Wmaybe-uninitialized]
if (rate_discrete)
^
../drivers/firmware/arm_scmi/clock.c:128:7: note:
'rate_discrete' was declared here
bool rate_discrete;
^
This patch fixing the warning by initialising rate_discrete and also using
goto label for the error path.
Fixes: 5f6c6430e9 ("firmware: arm_scmi: add initial support for clock protocol")
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
[sudeep.holla: added one line description to the commit message]
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
If the "etc/vmcoreinfo" fw_cfg file is present and we are not running
the kdump kernel, write the addr/size of the vmcoreinfo ELF note.
The DMA operation is expected to run synchronously with today qemu,
but the specification states that it may become async, so we run
"control" field check in a loop for eventual changes.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Add an optional <dma_off> kernel module (or command line) parameter
using the following syntax:
[qemu_fw_cfg.]ioport=<size>@<base>[:<ctrl_off>:<data_off>[:<dma_off>]]
or
[qemu_fw_cfg.]mmio=<size>@<base>[:<ctrl_off>:<data_off>[:<dma_off>]]
and initializes the register address using given or default offset.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Gabriel Somlo <somlo@cmu.edu>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Create a common header file for well-known values and structures to be
shared by the Linux kernel with qemu or other projects.
It is based from qemu/docs/specs/fw_cfg.txt which references
qemu/include/hw/nvram/fw_cfg_keys.h "for the most up-to-date and
authoritative list" & vmcoreinfo.txt. Those files don't have an
explicit license, but qemu/hw/nvram/fw_cfg.c is BSD-license, so
Michael S. Tsirkin suggested to use the same license.
The patch intentionally left out DMA & vmcoreinfo structures &
defines, which are added in the commits making usage of it.
Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
fw_cfg_read_blob() may fail, but does not return error. This may lead
to surprising behaviours, like populating zero file entries (in
register_file() or during read). Return an error if ACPI locking
failed. Also, the following DMA read/write extension will add more
error paths that should be handled appropriately.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
The function is not small and getting bigger.
Let the compiler decide instead. No profiling done, hopefully
unnecessary.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Use struct fw_cfg_files to read the directory size, fixing the sparse
warnings:
drivers/firmware/qemu_fw_cfg.c:485:17: warning: cast to restricted __be32
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Use a restricted type for reading FW_CFG_ID, fixing sparse warning:
drivers/firmware/qemu_fw_cfg.c:540:22: warning: cast to restricted __le32
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Modify fw_cfg_sysfs_entry to store entry values, instead of reusing
the restricted types.
Fixes warnings such as:
$ make C=1 CF=-D__CHECK_ENDIAN__ drivers/firmware/qemu_fw_cfg.o
drivers/firmware/qemu_fw_cfg.c:491:29: warning: incorrect type in assignment (different base types)
drivers/firmware/qemu_fw_cfg.c:491:29: expected restricted __be32 [usertype] size
drivers/firmware/qemu_fw_cfg.c:491:29: got unsigned int
drivers/firmware/qemu_fw_cfg.c:492:31: warning: incorrect type in assignment (different base types)
drivers/firmware/qemu_fw_cfg.c:492:31: expected restricted __be16 [usertype] select
drivers/firmware/qemu_fw_cfg.c:492:31: got int
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Dispatch to the appropriate iowrite() instead of casting restricted
type to u16.
- if fw_cfg_is_mmio:
before: iowrite16(cpu_to_be16(key))
after: iowrite16be(key)
- if !fw_cfg_is_mmio:
before: iowrite16(cpu_to_le16(key))
after: iowrite16(key)
which is equivalent on little-endian systems, where fw_cfg IO is supported.
Fixes:
$ make C=1 CF=-D__CHECK_ENDIAN__ drivers/firmware/qemu_fw_cfg.o
drivers/firmware/qemu_fw_cfg.c:55:33: warning: restricted __be16 degrades to integer
drivers/firmware/qemu_fw_cfg.c:55:52: warning: restricted __le16 degrades to integer
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Pull EFI fix from Thomas Gleixner:
"A single fix to prevent partially initialized pointers in mixed mode
(64bit kernel on 32bit UEFI)"
* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
efi/libstub/tpm: Initialize pointer variables to zero for mixed mode
Update the initcall ordering to satisfy the following dependency
ordering:
1. DCDBAS, ACPI_WMI
2. DELL_SMBIOS, DELL_RBTN
3. DELL_LAPTOP, DELL_WMI
By assigning them to the following initcall levels:
subsys_initcall: DCDBAS, ACPI_WMI
module_init: DELL_SMBIOS, DELL_RBTN
late_initcall: DELL_LAPTOP, DELL_WMI
Cc: Dominik Brodowski <linux@dominikbrodowski.net>
Cc: Mario.Limonciello@dell.com
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
As reported by Tyler, efi_esrt_init() will return without releasing the
ESRT table header mapping if it encounters a table with an unexpected
version. Replacing the 'return' with 'goto err_memunmap' would fix this
particular occurrence, but, as it turns out, the code is rather peculiar
to begin with:
- it never uses the header mapping after memcpy()'ing out its contents,
- it maps and unmaps the entire table without ever looking at the
contents.
So let's refactor this code to unmap the table header right after the
memcpy() so we can get rid of the error handling path altogether, and
drop the second mapping entirely.
Reported-by: Tyler Baicar <tbaicar@codeaurora.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Matt Fleming <matt@codeblueprint.co.uk>
Cc: Peter Jones <pjones@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/20180312084500.10764-5-ard.biesheuvel@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Check the variable that was most recently initialized.
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression x, y, f, g, e, m;
statement S1,S2,S3,S4;
@@
x = f(...);
if (\(<+...x...+>\&e\)) S1 else S2
(
x = g(...);
|
m = g(...,&x,...);
|
y = g(...);
*if (e)
S3 else S4
)
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
The Tegra194 BPMP only implements 5 channels (4 to BPMP, 1 to CCPLEX),
and they are not placed contiguously in memory. The current channel
management in the BPMP driver does not support this.
Simplify and refactor the channel management such that only one atomic
transmit channel and one receive channel are supported, and channels
are not required to be placed contiguously in memory. The same
configuration also works on T186 so we end up with less code.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Commit 3aa0582fdb ("of: platform: populate /firmware/ node from
of_platform_default_populate_init()") takes care of populating
all the devices under the /firmware/ node in of_platform_default_populate_init()
This patch reworks meson_sm_init to use module_platform_driver_probe as
the platform device is populated.
Cc: Carlo Caione <carlo@caione.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: linux-amlogic@lists.infradead.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Pull "ARM SCMI support for v4.17" from Sudeep Holla:
ARM System Control and Management Interface(SCMI)[1] is more flexible and
easily extensible than any of the existing interfaces.
Few existing as well as future ARM platforms provide micro-controllers
to abstract various power and other system management tasks which have
similar interfaces, both in terms of the functions that are provided by
them, and in terms of how requests are communicated to them.
There are quite a few protocols like ARM SCPI, TI SCI, QCOM RPM, Nvidia Tegra
BPMP, and so on already. This specification is to standardize and avoid any
further fragmentation in the design of such interface by various vendors.
The current SCMI driver implementation is very basic and initial support.
It lacks support for notifications, asynchronous/delayed response, perf/power
statistics region and sensor register region.
Mailbox is the only form of transport supported currently in the driver.
SCMI supports interrupt based mailbox communication, where, on completion
of the processing of a message, the caller receives an interrupt as well as
polling for completion.
SCMI is designed to minimize the dependency on the mailbox/transport
hardware. So in terms of SCMI, each channel in the mailbox includes
memory area, doorbell and completion interrupt.
However the doorbell and completion interrupt is highly mailbox dependent
which was bit of controversial as part of SCMI/mailbox discussions.
Arnd and me discussed about the few aspects of SCMI and the mailbox framework:
1. Use of mailbox framework for doorbell type mailbox controller:
- Such hardware may not require any data to be sent to signal the remote
about the presence of a message. The channel will have in-built
information on how to trigger the signal to the remote.
There are few mailbox controller drivers which are purely doorbell based.
e.g.QCOM IPC, STM, Tegra, ACPI PCC,..etc
2. Supporting other mailbox controller:
- SCMI just needs a mechanism to signal the remote firmware. Such
controller may need fixed message to be sent to trigger a doorbell.
In such case we may need to get that data from DT and pass the same
to the controller. It's not covered in the current DT binding, but
can be extended as optional property in future.
However handling notifications may be interesting on such mailbox, but
again there is no way to interpret what the data field(remote message)
means, it could be a bit mask or a number or don't-care.
Arnd mentioned that he doesn't like the way the mailbox binding deals
with doorbell-type hardware, but we do have quite a few precedent drivers
already and changing the binding to add a data field would not make it any
better, but could cause other problems. So he is happy with the status quo
of SCMI implementation.
[1] http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.den0056a/index.html
* tag 'scmi-updates-4.17' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
cpufreq: scmi: add support for fast frequency switching
cpufreq: add support for CPU DVFS based on SCMI message protocol
hwmon: add support for sensors exported via ARM SCMI
hwmon: (core) Add hwmon_max to hwmon_sensor_types enumeration
clk: add support for clocks provided by SCMI
firmware: arm_scmi: add device power domain support using genpd
firmware: arm_scmi: add per-protocol channels support using idr objects
firmware: arm_scmi: refactor in preparation to support per-protocol channels
firmware: arm_scmi: add option for polling based performance domain operations
firmware: arm_scmi: add support for polling based SCMI transfers
firmware: arm_scmi: probe and initialise all the supported protocols
firmware: arm_scmi: add initial support for sensor protocol
firmware: arm_scmi: add initial support for power protocol
firmware: arm_scmi: add initial support for clock protocol
firmware: arm_scmi: add initial support for performance protocol
firmware: arm_scmi: add scmi protocol bus to enumerate protocol devices
firmware: arm_scmi: add common infrastructure and support for base protocol
firmware: arm_scmi: add basic driver infrastructure for SCMI
dt-bindings: arm: add support for ARM System Control and Management Interface(SCMI) protocol
dt-bindings: mailbox: add support for mailbox client shared memory
This patch hooks up the support for device power domain provided by
SCMI using the Linux generic power domain infrastructure.
Cc: Kevin Hilman <khilman@baylibre.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
In order to maintain the channel information per protocol, we need
some sort of list or hashtable to hold all this information. IDR
provides sparse array mapping of small integer ID numbers onto arbitrary
pointers. In this case the arbitrary pointers can be pointers to the
channel information.
This patch adds support for per-protocol channels using those idr
objects.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
In order to support per-protocol channels if available, we need to
factor out all the mailbox channel information(Tx/Rx payload and
channel handle) out of the main SCMI instance information structure.
This patch refactors the existing channel information into a separate
chan_info structure.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
In order to implement fast CPU DVFS switching, we need to perform all
DVFS operations atomically. Since SCMI transfer already provide option
to choose between pooling vs interrupt driven(default), we can opt for
polling based transfers for set,get performance domain operations.
This patch adds option to choose between polling vs interrupt driven
SCMI transfers for set,get performance level operations.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
It would be useful to have options to perform some SCMI transfers
atomically by polling for the completion flag instead of interrupt
driven. The SCMI specification has option to disable the interrupt and
poll for the completion flag in the shared memory.
This patch adds support for polling based SCMI transfers using that
option. This might be used for uninterrupted/atomic DVFS operations
from the scheduler context.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Now that we have basic support for all the protocols in the
specification, let's probe them individually and initialise them.
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
