Commit Graph

3649 Commits

Author SHA1 Message Date
Kieran Bingham
6a71d8d777 device property: Add fwnode_graph_get_port_parent
Provide a helper to obtain the parent device fwnode without first
parsing the remote-endpoint as per fwnode_graph_get_remote_port_parent.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-22 02:55:34 +02:00
Sakari Ailus
125ee6b3b0 device property: Add FW type agnostic fwnode_graph_get_remote_node
Add fwnode_graph_get_remote_node() function which is equivalent to
of_graph_get_remote_node() on OF.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-22 02:55:34 +02:00
Sakari Ailus
2294b3af05 device property: Introduce fwnode_device_is_available()
Add fwnode_device_is_available() to tell whether the device corresponding
to a certain fwnode_handle is available for use.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-22 02:55:34 +02:00
Sakari Ailus
3b27d00e7b device property: Move fwnode graph ops to firmware specific locations
Move firmware specific implementations of the fwnode graph operations to
firmware specific locations.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-22 02:55:34 +02:00
Sakari Ailus
3708184afc device property: Move FW type specific functionality to FW specific files
The device and fwnode property API supports Devicetree, ACPI and pset
properties. The implementation of this functionality for each firmware
type was embedded in the fwnode property core. Move it out to firmware
type specific locations, making it easier to maintain.

Depends-on: ("of: Move OF property and graph API from base.c to property.c")
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-22 02:55:34 +02:00
Ingo Molnar
902b319413 Merge branch 'WIP.sched/core' into sched/core
Conflicts:
	kernel/sched/Makefile

Pick up the waitqueue related renames - it didn't get much feedback,
so it appears to be uncontroversial. Famous last words? ;-)

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-20 12:28:21 +02:00
Olof Johansson
f39b24e0b4 Merge tag 'tegra-for-4.13-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux into next/drivers
soc/tegra: Changes for v4.13-rc1

This contains an implementation of generic PM domains for Tegra186,
based on the BPMP powergate request.

* tag 'tegra-for-4.13-soc' of git://git.kernel.org/pub/scm/linux/kernel/git/tegra/linux:
  soc/tegra: flowctrl: Fix error handling
  soc/tegra: bpmp: Implement generic PM domains
  soc/tegra: bpmp: Update ABI header
  PM / Domains: Allow overriding the ->xlate() callback

Signed-off-by: Olof Johansson <olof@lixom.net>
2017-06-18 21:01:02 -07:00
Rafael J. Wysocki
33e4f80ee6 ACPI / PM: Ignore spurious SCI wakeups from suspend-to-idle
The ACPI SCI (System Control Interrupt) is set up as a wakeup IRQ
during suspend-to-idle transitions and, consequently, any events
signaled through it wake up the system from that state.  However,
on some systems some of the events signaled via the ACPI SCI while
suspended to idle should not cause the system to wake up.  In fact,
quite often they should just be discarded.

Arguably, systems should not resume entirely on such events, but in
order to decide which events really should cause the system to resume
and which are spurious, it is necessary to resume up to the point
when ACPI SCIs are actually handled and processed, which is after
executing dpm_resume_noirq() in the system resume path.

For this reasons, add a loop around freeze_enter() in which the
platforms can process events signaled via multiplexed IRQ lines
like the ACPI SCI and add suspend-to-idle hooks that can be
used for this purpose to struct platform_freeze_ops.

In the ACPI case, the ->wake hook is used for checking if the SCI
has triggered while suspended and deferring the interrupt-induced
system wakeup until the events signaled through it are actually
processed sufficiently to decide whether or not the system should
resume.  In turn, the ->sync hook allows all of the relevant event
queues to be flushed so as to prevent events from being missed due
to race conditions.

In addition to that, some ACPI code processing wakeup events needs
to be modified to use the "hard" version of wakeup triggers, so that
it will cause a system resume to happen on device-induced wakeup
events even if the "soft" mechanism to prevent the system from
suspending is not enabled.  However, to preserve the existing
behavior with respect to suspend-to-RAM, this only is done in
the suspend-to-idle case and only if an SCI has occurred while
suspended.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-15 00:55:44 +02:00
Rafael J. Wysocki
604d895857 PM / sleep: Print timing information if debug is enabled
Avoid printing the device suspend/resume timing information if
CONFIG_PM_DEBUG is not set to reduce the log noise level.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-15 00:55:43 +02:00
Thierry Reding
408455245a PM / Domains: Allow overriding the ->xlate() callback
Allow generic power domain providers to override the ->xlate() callback
in case the default genpd_xlate_onecell() translation callback is not
good enough.

One potential use-case for this is to allow generic power domains to be
specified by an ID rather than an index.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2017-06-13 15:15:08 +02:00
Johan Hovold
ed032c1bed driver core: fix automatic pinctrl management
Commit ab78029ecc ("drivers/pinctrl: grab default handles from device
core") added automatic pin-control management to driver core by looking
up and setting any default pinctrl state found in device tree while a
device is being probed.

This obviously runs into problems as soon as device-tree nodes are
reused for child devices which are later also probed as pins would
already have been claimed by the ancestor device.

For example if a USB host controller claims a pin, its root hub would
consequently fail to probe when its device-tree node is set to the node
of the controller:

    pinctrl-single 48002030.pinmux: pin PIN204 already requested by 48064800.ehci; cannot claim for usb1
    pinctrl-single 48002030.pinmux: pin-204 (usb1) status -22
    pinctrl-single 48002030.pinmux: could not request pin 204 (PIN204) from group usb_dbg_pins  on device pinctrl-single
    usb usb1: Error applying setting, reverse things back
    usb: probe of usb1 failed with error -22

Fix this by checking the new of_node_reused flag and skipping automatic
pinctrl configuration during probe if set.

Note that the flag is checked in driver core rather than in pinctrl
(e.g. in pinctrl_dt_to_map()) which would specifically have prevented
intentional use of a parent's pinctrl properties by a child device
(should such a need ever arise).

Fixes: ab78029ecc ("drivers/pinctrl: grab default handles from device core")
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-13 11:07:32 +02:00
Johan Hovold
4e75e1d7da driver core: add helper to reuse a device-tree node
Add a helper function to be used when reusing the device-tree node of
another device.

It is fairly common for drivers to reuse the device-tree node of a
parent (or other ancestor) device when creating class or bus devices
(e.g. gpio chips, i2c adapters, iio chips, spi masters, serdev, phys,
usb root hubs). But reusing a device-tree node may cause problems if the
new device is later probed as for example driver core would currently
attempt to reinitialise an already active associated pinmux
configuration.

Other potential issues include the platform-bus code unconditionally
dropping the device-tree node reference in its device destructor,
reinitialisation of other bus-managed resources such as clocks, and the
recently added DMA-setup in driver core.

Note that for most examples above this is currently not an issue as the
devices are never probed, but this is a problem for the USB bus which
has recently gained device-tree support. This was discovered and
worked-around in a rather ad-hoc fashion by commit dc5878abf4 ("usb:
core: move root hub's device node assignment after it is added to bus")
by not setting the of_node pointer until after the root-hub device has
been registered.

Instead we can allow devices to reuse a device-tree node by setting a
flag in their struct device that can be used by core, bus and driver
code to avoid resources from being over-allocated.

Note that the helper also grabs an extra reference to the device node,
which specifically balances the unconditional put in the platform-device
destructor.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-13 11:07:32 +02:00
Greg Kroah-Hartman
b46c73378c driver-core: remove struct bus_type.dev_attrs
Now that all in-kernel users of bus_type.dev_attrs have been converted
to use dev_groups instead, the dev_attrs field, and logic surrounding
it, can be removed.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-12 16:18:37 +02:00
Vladimir Zapolskiy
63c73b059c regmap: irq: allow to register one cell interrupt controllers
The change makes possible to use regmap-irq interface within drivers
of simple interrupt controllers, which don't have an option to handle
different interrupt types and thus have one cell interrupt controllers
described in device tree bindings.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-06-09 18:38:06 +01:00
Greg Kroah-Hartman
ecbaa83ee8 driver core: remove class_attrs from struct class
This field is no longer used or needed (use class_groups instead), so it
can be removed along with the driver core functionality that created and
removed these files.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-09 10:41:00 +02:00
Rafael J. Wysocki
fbd78afe34 Merge branches 'intel_pstate' and 'pm-sleep'
* intel_pstate:
  cpufreq: intel_pstate: Avoid division by 0 in min_perf_pct_min()

* pm-sleep:
  Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"
2017-06-09 01:25:16 +02:00
Mark Brown
f458e6102c regmap: Fix typo in IS_ENABLED() check
Reported-by: Andreas Ziegler <andreas.ziegler@fau.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-06-08 15:43:19 +01:00
Rafael J. Wysocki
f3b7eaae1b Revert "ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle"
Revert commit eed4d47efe (ACPI / sleep: Ignore spurious SCI wakeups
from suspend-to-idle) as it turned out to be premature and triggered
a number of different issues on various systems.

That includes, but is not limited to, premature suspend-to-RAM aborts
on Dell XPS 13 (9343) reported by Dominik.

The issue the commit in question attempted to address is real and
will need to be taken care of going forward, but evidently more work
is needed for this purpose.

Reported-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-06-07 00:57:37 +02:00
Mark Brown
c13be1d942 Merge branch 'topic/lzo' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap into regmap-1wire 2017-06-06 20:10:47 +01:00
Alex A. Mihaylov
cc5d0db390 regmap: Add 1-Wire bus support
Add basic support regmap (register map access) API for 1-Wire bus

Signed-off-by: Mark Brown <broonie@kernel.org>
2017-06-06 19:47:28 +01:00
Jonas Gorski
34a730aa74 regmap: make LZO cache optional
Commit 2cbbb579bc ("regmap: Add the LZO cache support") added support
for LZO compression in regcache, but there were never any users added
afterwards. Since LZO support itself has its own size, it currently is
rather a deoptimization.

So make it optional by introducing a symbol that can be selected by
drivers wanting to make use of it.

Saves e.g. ~46 kB on MIPS (size of LZO support + regcache LZO code).

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2017-06-06 19:46:57 +01:00
Luis R. Rodriguez
06a45a93e7 firmware: move umh try locks into the umh code
This moves the usermode helper locks into only code paths that use the
usermode helper API from the kernel. The usermode helper locks were
originally added to prevent stalling suspend, later the firmware cache
was added to help with this, and further later direct filesystem lookup
was added by Linus to completely bypass udev due to the amount of issues
the umh approach had.

The usermode helper locks were kept even when the direct filesystem lookup
mechanism is used though. A lot has changed since the original usermode
helper locks were added but the recent commit which added the code for
firmware_enabled() are intended to address any possible races cured only
as collateral by using the locks as though side consequence of code
evolution and this not being addressed any time sooner. With the
firmware_enabled() code in place we are a bit more sure to move the
usermode helper locks to UMH only code.

There is a bit of history here so let's recap a bit of it to ensure nothing
is lost and things are clear. The direct filesystem approach to loading
firmware is rather new, it was added via commit abb139e75c ("firmware:
teach the kernel to load firmware files directly from the filesystem") by
Linus merged on the v3.7 release, to enable to bypass udev.

usermodehelper_read_lock_wait() was added earlier via commit 9b78c1da60
("firmware_class: Do not warn that system is not ready from async loads")
merged on v3.4, after Rafael noted that the async firmware API call
request_firmware_nowait() should not be penalized to fail if userspace is
not available yet or frozen, it'd allow for a timeout grace period before
giving up. The WARN_ON() was kept for the sync firmware API call though on
request_firmware(). At this time there was no direct filesystem lookup for
firmware though.

The original usermode helper lock came from commit a144c6a6c9 ("PM:
Print a warning if firmware is requested when tasks are frozen") merged on
the v3.0 kernel by Rafael to print a warning back when firmware requests
were used on resume(), thaw() or restore() callbacks and there was no
direct fs lookups or the firmware cache.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 19:15:50 +09:00
Luis R. Rodriguez
8509adcaa9 firmware: move assign_firmware_buf() further up
This will make subsequent changes easier to read.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 19:15:50 +09:00
Luis R. Rodriguez
81f9507628 firmware: add sanity check on shutdown/suspend
The firmware API should not be used after we go to suspend
and after we reboot/halt. The suspend/resume case is a bit
complex, so this documents that so things are clearer.

We want to know about users of the API in incorrect places so
that their callers are corrected, so this also adds a warn
for those cases.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 19:15:49 +09:00
Luis R. Rodriguez
a669f04ab4 firmware: always enable the reboot notifier
Now that we've have proper wrappers for the fallback mechanism
we can easily share the reboot notifier for the firmware_class
at all times.

This change will make subsequent modifications to the reboot
notifier easier to review.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 19:15:49 +09:00
Luis R. Rodriguez
c4b768934b firmware: share fw fallback killing on reboot/suspend
We kill pending fallback requests on suspend and reboot,
the only difference is that on suspend we only kill custom
fallback requests. Provide a wrapper that lets us customize
the request with a flag.

This also lets us simplify the #ifdef'ery over the calls.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 19:15:49 +09:00
Luis R. Rodriguez
6383331d8f firmware: move kill_requests_without_uevent() up above
This routine will used in functions declared earlier next. This
code shift has no functional changes, it will make subsequent
changes easier to read.

Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 19:15:49 +09:00
Juri Lelli
4ca4f26a9c arm,arm64,drivers: add a prefix to drivers arch_topology interfaces
Now that some functions that deal with arch topology information live
under drivers, there is a clash of naming that might create confusion.

Tidy things up by creating a topology namespace for interfaces used by
arch code; achieve this by prepending a 'topology_' prefix to driver
interfaces.

Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 19:10:09 +09:00
Juri Lelli
615ffd6314 arm,arm64,drivers: move externs in a new header file
Create a new header file (include/linux/arch_topology.h) and put there
declarations of interfaces used by arm, arm64 and drivers code.

Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 19:10:09 +09:00
Juri Lelli
c105aa3118 arm,arm64,drivers: reduce scope of cap_parsing_failed
Reduce the scope of cap_parsing_failed (making it static in
drivers/base/arch_topology.c) by slightly changing {arm,arm64} DT
parsing code.

For arm checking for !cap_parsing_failed before calling normalize_
cpu_capacity() is superfluous, as returning an error from parse_
cpu_capacity() (above) means cap_from _dt is set to false.

For arm64 we can simply check if raw_capacity points to something,
which is not if capacity parsing has failed.

Suggested-by: Morten Rasmussen <morten.rasmussen@arm.com>
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 19:10:09 +09:00
Juri Lelli
2ef7a2953c arm, arm64: factorize common cpu capacity default code
arm and arm64 share lot of code relative to parsing CPU capacity
information from DT, using that information for appropriate scaling and
exposing a sysfs interface for chaging such values at runtime.

Factorize such code in a common place (driver/base/arch_topology.c) in
preparation for further additions.

Suggested-by: Will Deacon <will.deacon@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Acked-by: Russell King <rmk+kernel@armlinux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 19:10:09 +09:00
Catalin Marinas
1a3389ffc5 drivers: dma-mapping: Do not leave an invalid area->pages pointer in dma_common_contiguous_remap()
The dma_common_pages_remap() function allocates a vm_struct object and
initialises the pages pointer to value passed as argument. However, when
this function is called dma_common_contiguous_remap(), the pages array
is only temporarily allocated, being freed shortly after
dma_common_contiguous_remap() returns. Architecture code checking the
validity of an area->pages pointer would incorrectly dereference already
freed pointers. This has been exposed by the arm64 commit 44176bb38f
("arm64: Add support for DMA_ATTR_FORCE_CONTIGUOUS to IOMMU").

Fixes: 513510ddba ("common: dma-mapping: introduce common remapping functions")
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Andrzej Hajda <a.hajda@samsung.com>
Acked-by: Laura Abbott <labbott@redhat.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-03 18:51:12 +09:00
Peter Rajnoha
f36776fafb kobject: support passing in variables for synthetic uevents
This patch makes it possible to pass additional arguments in addition
to uevent action name when writing /sys/.../uevent attribute. These
additional arguments are then inserted into generated synthetic uevent
as additional environment variables.

Before, we were not able to pass any additional uevent environment
variables for synthetic uevents. This made it hard to identify such uevents
properly in userspace to make proper distinction between genuine uevents
originating from kernel and synthetic uevents triggered from userspace.
Also, it was not possible to pass any additional information which would
make it possible to optimize and change the way the synthetic uevents are
processed back in userspace based on the originating environment of the
triggering action in userspace. With the extra additional variables, we are
able to pass through this extra information needed and also it makes it
possible to synchronize with such synthetic uevents as they can be clearly
identified back in userspace.

The format for writing the uevent attribute is following:

    ACTION [UUID [KEY=VALUE ...]

There's no change in how "ACTION" is recognized - it stays the same
("add", "change", "remove"). The "ACTION" is the only argument required
to generate synthetic uevent, the rest of arguments, that this patch
adds support for, are optional.

The "UUID" is considered as transaction identifier so it's possible to
use the same UUID value for one or more synthetic uevents in which case
we logically group these uevents together for any userspace listeners.
The "UUID" is expected to be in "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
format where "x" is a hex digit. The value appears in uevent as
"SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" environment variable.

The "KEY=VALUE" pairs can contain alphanumeric characters only. It's
possible to define zero or more more pairs - each pair is then delimited
by a space character " ". Each pair appears in synthetic uevents as
"SYNTH_ARG_KEY=VALUE" environment variable. That means the KEY name gains
"SYNTH_ARG_" prefix to avoid possible collisions with existing variables.
To pass the "KEY=VALUE" pairs, it's also required to pass in the "UUID"
part for the synthetic uevent first.

If "UUID" is not passed in, the generated synthetic uevent gains
"SYNTH_UUID=0" environment variable automatically so it's possible to
identify this situation in userspace when reading generated uevent and so
we can still make a difference between genuine and synthetic uevents.

Signed-off-by: Peter Rajnoha <prajnoha@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25 18:30:51 +02:00
Adrian Salido
6265539776 driver core: platform: fix race condition with driver_override
The driver_override implementation is susceptible to race condition when
different threads are reading vs storing a different driver override.
Add locking to avoid race condition.

Fixes: 3d713e0e38 ("driver core: platform: add device binding path 'driver_override'")
Cc: stable@vger.kernel.org
Signed-off-by: Adrian Salido <salidoa@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-05-25 15:30:12 +02:00
Thomas Gleixner
8cdde385c7 mm: Adjust system_state check
To enable smp_processor_id() and might_sleep() debug checks earlier, it's
required to add system states between SYSTEM_BOOTING and SYSTEM_RUNNING.

get_nid_for_pfn() checks for system_state == BOOTING to decide whether to
use early_pfn_to_nid() when CONFIG_DEFERRED_STRUCT_PAGE_INIT=y.

That check is dubious, because the switch to state RUNNING happes way after
page_alloc_init_late() has been invoked.

Change the check to less than RUNNING state so it covers the new
intermediate states as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170516184735.528279534@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-05-23 10:01:36 +02:00
Rafael J. Wysocki
bb47e96417 Merge branches 'pm-sleep' and 'powercap'
* pm-sleep:
  PM / hibernate: Declare variables as static
  RTC: rtc-cmos: Fix wakeup from suspend-to-idle
  PM / wakeup: Fix up wakeup_source_report_event()

* powercap:
  PowerCap: Fix an error code in powercap_register_zone()
2017-05-22 20:32:05 +02:00
Rafael J. Wysocki
60d4553bdc PM / wakeup: Fix up wakeup_source_report_event()
Commit 8a537ece3d (PM / wakeup: Integrate mechanism to abort
transitions in progress) modified wakeup_source_report_event()
and wakeup_source_activate() to make it possible to call
pm_system_wakeup() from the latter if so indicated by the
caller of the former (via a new function argument added by that
commit), but it overlooked the fact that in some situations
wakeup_source_report_event() is called to signal a "hard" event
(ie. such that should abort a system suspend in progress) after
pm_stay_awake() has been called for the same wakeup source object,
in which case the pm_system_wakeup() will not trigger.

To work around this issue, modify wakeup_source_activate() and
wakeup_source_report_event() again so that pm_system_wakeup() is
called by the latter directly (if its last argument is true), in
which case the additional argument does not need to be passed
to wakeup_source_activate() any more, so drop it from there.

Fixes: 8a537ece3d (PM / wakeup: Integrate mechanism to abort transitions in progress)
Reported-by: David E. Box <david.e.box@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-05-14 02:23:04 +02:00
Linus Torvalds
2e4ab937ec Merge tag 'pm-extra-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more power management updates from Rafael Wysocki:
 "These add new CPU IDs to a couple of drivers, fix a possible NULL
  pointer dereference in the cpuidle core, update DT-related things in
  the generic power domains framework and finally update the
  suspend/resume infrastructure to improve the handling of wakeups from
  suspend-to-idle.

  Specifics:

   - Add Intel Gemini Lake CPU IDs to the intel_idle and intel_rapl
     drivers (David Box).

   - Add a NULL pointer check to the cpuidle core to prevent it from
     crashing on platforms with incomplete cpuidle configuration (Fei
     Li).

   - Fix DT-related documentation in the generic power domains (genpd)
     framework and add a MAINTAINERS entry for DT-related material in
     genpd (Viresh Kumar).

   - Update the system suspend/resume infrastructure to improve the
     handling of aborts of suspend transitions in progress in the wakeup
     framework and rework the suspend-to-idle core loop to make it
     possible to filter out spurious wakeup events (specifically the
     ones coming from ACPI) without resuming all the way up to user
     space every time (Rafael Wysocki)"

* tag 'pm-extra-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle
  PM / wakeup: Integrate mechanism to abort transitions in progress
  x86/intel_idle: add Gemini Lake support
  cpuidle: check dev before usage in cpuidle_use_deepest_state()
  powercap: intel_rapl: Add support for Gemini Lake
  PM / Domains: Add DT file to MAINTAINERS
  PM / Domains: Fix DT example
2017-05-10 09:12:30 -07:00
Linus Torvalds
28b47809b2 Merge tag 'iommu-updates-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull IOMMU updates from Joerg Roedel:

 - code optimizations for the Intel VT-d driver

 - ability to switch off a previously enabled Intel IOMMU

 - support for 'struct iommu_device' for OMAP, Rockchip and Mediatek
   IOMMUs

 - header optimizations for IOMMU core code headers and a few fixes that
   became necessary in other parts of the kernel because of that

 - ACPI/IORT updates and fixes

 - Exynos IOMMU optimizations

 - updates for the IOMMU dma-api code to bring it closer to use per-cpu
   iova caches

 - new command-line option to set default domain type allocated by the
   iommu core code

 - another command line option to allow the Intel IOMMU switched off in
   a tboot environment

 - ARM/SMMU: TLB sync optimisations for SMMUv2, Support for using an
   IDENTITY domain in conjunction with DMA ops, Support for SMR masking,
   Support for 16-bit ASIDs (was previously broken)

 - various other small fixes and improvements

* tag 'iommu-updates-v4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (63 commits)
  soc/qbman: Move dma-mapping.h include to qman_priv.h
  soc/qbman: Fix implicit header dependency now causing build fails
  iommu: Remove trace-events include from iommu.h
  iommu: Remove pci.h include from trace/events/iommu.h
  arm: dma-mapping: Don't override dma_ops in arch_setup_dma_ops()
  ACPI/IORT: Fix CONFIG_IOMMU_API dependency
  iommu/vt-d: Don't print the failure message when booting non-kdump kernel
  iommu: Move report_iommu_fault() to iommu.c
  iommu: Include device.h in iommu.h
  x86, iommu/vt-d: Add an option to disable Intel IOMMU force on
  iommu/arm-smmu: Return IOVA in iova_to_phys when SMMU is bypassed
  iommu/arm-smmu: Correct sid to mask
  iommu/amd: Fix incorrect error handling in amd_iommu_bind_pasid()
  iommu: Make iommu_bus_notifier return NOTIFY_DONE rather than error code
  omap3isp: Remove iommu_group related code
  iommu/omap: Add iommu-group support
  iommu/omap: Make use of 'struct iommu_device'
  iommu/omap: Store iommu_dev pointer in arch_data
  iommu/omap: Move data structures to omap-iommu.h
  iommu/omap: Drop legacy-style device support
  ...
2017-05-09 15:15:47 -07:00
Rafael J. Wysocki
80449d89d4 Merge branches 'pm-domains', 'pm-cpuidle', 'pm-sleep' and 'powercap'
* pm-domains:
  PM / Domains: Add DT file to MAINTAINERS
  PM / Domains: Fix DT example

* pm-cpuidle:
  x86/intel_idle: add Gemini Lake support
  cpuidle: check dev before usage in cpuidle_use_deepest_state()

* pm-sleep:
  ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle
  PM / wakeup: Integrate mechanism to abort transitions in progress

* powercap:
  powercap: intel_rapl: Add support for Gemini Lake
2017-05-09 23:21:46 +02:00
Linus Torvalds
0160e00ae8 Merge tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC driver updates from Olof Johansson:
 "Driver updates for ARM SoCs:

  Reset subsystem, merged through arm-soc by tradition:
   - Make bool drivers explicitly non-modular
   - New support for i.MX7 and Arria10 reset controllers

  PATA driver for Palmchip BK371 (acked by Tejun)

  Power domain drivers for i.MX (GPC, GPCv2)
   - Moved out of mach-imx for GPC
   - Bunch of tweaks, fixes, etc

  PMC support for Tegra186

  SoC detection support for Renesas RZ/G1H and RZ/G1N

  Move Tegra flow controller driver from mach directory to drivers/soc
   - (Power management / CPU power driver)

  Misc smaller tweaks for other platforms"

* tag 'armsoc-drivers' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (60 commits)
  soc: pm-domain: Fix the mangled urls
  soc: renesas: rcar-sysc: Add support for R-Car H3 ES2.0
  soc: renesas: rcar-sysc: Add support for fixing up power area tables
  soc: renesas: Register SoC device early
  soc: imx: gpc: add workaround for i.MX6QP to the GPC PD driver
  dt-bindings: imx-gpc: add i.MX6 QuadPlus compatible
  soc: imx: gpc: add defines for domain index
  soc: imx: Add GPCv2 power gating driver
  dt-bindings: Add GPCv2 power gating driver
  ARM/clk: move the ICST library to drivers/clk
  ARM: plat-versatile: remove stale clock header
  ARM: keystone: Drop PM domain support for k2g
  soc: ti: Add ti_sci_pm_domains driver
  dt-bindings: Add TI SCI PM Domains
  PM / Domains: Do not check if simple providers have phandle cells
  PM / Domains: Add generic data pointer to genpd data struct
  soc/tegra: Add initial flowctrl support for Tegra132/210
  soc/tegra: flowctrl: Add basic platform driver
  soc/tegra: Move Tegra flowctrl driver
  ARM: tegra: Remove unnecessary inclusion of flowctrl header
  ...
2017-05-09 10:01:15 -07:00
Linus Torvalds
3ef2bc099d Merge tag 'devicetree-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull DeviceTree updates from Rob Herring:

 - fix sparse warnings in drivers/of/

 - add more overlay unittests

 - update dtc to v1.4.4-8-g756ffc4f52f6. This adds more checks on dts
   files such as unit-address formatting and stricter character sets for
   node and property names

 - add a common DT modalias function

 - move trivial-devices.txt up and out of i2c dir

 - ARM NVIC interrupt controller binding

 - vendor prefixes for Sensirion, Dioo, Nordic, ROHM

 - correct some binding file locations

* tag 'devicetree-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (24 commits)
  of: fix sparse warnings in fdt, irq, reserved mem, and resolver code
  of: fix sparse warning in of_pci_range_parser_one
  of: fix sparse warnings in of_find_next_cache_node
  of/unittest: Missing unlocks on error
  of: fix uninitialized variable warning for overlay test
  of: fix unittest build without CONFIG_OF_OVERLAY
  of: Add unit tests for applying overlays
  of: per-file dtc compiler flags
  fpga: region: add missing DT documentation for config complete timeout
  of: Add vendor prefix for ROHM Semiconductor
  of: fix "/cpus" reference leak in of_numa_parse_cpu_nodes()
  of: Add vendor prefix for Nordic Semiconductor
  dt-bindings: arm,nvic: Binding for ARM NVIC interrupt controller on Cortex-M
  dtc: update warning settings for new bus and node/property name checks
  scripts/dtc: Update to upstream version v1.4.4-8-g756ffc4f52f6
  scripts/dtc: automate getting dtc version and log in update script
  of: Add function for generating a DT modalias with a newline
  of: fix of_device_get_modalias returned length when truncating buffers
  Documentation: devicetree: move trivial-devices out of I2C realm
  dt-bindings: add vendor prefix for Dioo
  ..
2017-05-05 19:33:07 -07:00
Linus Torvalds
c6a677c6f3 Merge tag 'staging-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging/IIO updates from Greg KH:
 "Here is the big staging tree update for 4.12-rc1.

  It's a big one, adding about 350k new lines of crap^Wcode, mostly all
  in a big dump of media drivers from Intel. But there's other new
  drivers in here as well, yet-another-wifi driver, new IIO drivers, and
  a new crypto accelerator.

  We also deleted a bunch of stuff, mostly in patch cleanups, but also
  the Android ION code has shrunk a lot, and the Android low memory
  killer driver was finally deleted, much to the celebration of the -mm
  developers.

  All of these have been in linux-next with a few build issues that will
  show up when you merge to your tree"

Merge conflicts in the new rtl8723bs driver (due to the wifi changes
this merge window) handled as per linux-next, courtesy of Stephen
Rothwell.

* tag 'staging-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (1182 commits)
  staging: fsl-mc/dpio: add cpu <--> LE conversion for dpaa2_fd
  staging: ks7010: remove line continuations in quoted strings
  staging: vt6656: use tabs instead of spaces
  staging: android: ion: Fix unnecessary initialization of static variable
  staging: media: atomisp: fix range checking on clk_num
  staging: media: atomisp: fix misspelled word in comment
  staging: media: atomisp: kmap() can't fail
  staging: atomisp: remove #ifdef for runtime PM functions
  staging: atomisp: satm include directory is gone
  atomisp: remove some more unused files
  atomisp: remove hmm_load/store/clear indirections
  atomisp: kill off mmgr_free
  atomisp: clean up the hmm init/cleanup indirections
  atomisp: handle allocation calls before init in the hmm layer
  staging: fsl-dpaa2/eth: Add maintainer for Ethernet driver
  staging: fsl-dpaa2/eth: Add TODO file
  staging: fsl-dpaa2/eth: Add trace points
  staging: fsl-dpaa2/eth: Add driver specific stats
  staging: fsl-dpaa2/eth: Add ethtool support
  staging: fsl-dpaa2/eth: Add Freescale DPAA2 Ethernet driver
  ...
2017-05-05 18:16:23 -07:00
Rafael J. Wysocki
eed4d47efe ACPI / sleep: Ignore spurious SCI wakeups from suspend-to-idle
The ACPI SCI (System Control Interrupt) is set up as a wakeup IRQ
during suspend-to-idle transitions and, consequently, any events
signaled through it wake up the system from that state.  However,
on some systems some of the events signaled via the ACPI SCI while
suspended to idle should not cause the system to wake up.  In fact,
quite often they should just be discarded.

Arguably, systems should not resume entirely on such events, but in
order to decide which events really should cause the system to resume
and which are spurious, it is necessary to resume up to the point
when ACPI SCIs are actually handled and processed, which is after
executing dpm_resume_noirq() in the system resume path.

For this reasons, add a loop around freeze_enter() in which the
platforms can process events signaled via multiplexed IRQ lines
like the ACPI SCI and add suspend-to-idle hooks that can be
used for this purpose to struct platform_freeze_ops.

In the ACPI case, the ->wake hook is used for checking if the SCI
has triggered while suspended and deferring the interrupt-induced
system wakeup until the events signaled through it are actually
processed sufficiently to decide whether or not the system should
resume.  In turn, the ->sync hook allows all of the relevant event
queues to be flushed so as to prevent events from being missed due
to race conditions.

In addition to that, some ACPI code processing wakeup events needs
to be modified to use the "hard" version of wakeup triggers, so that
it will cause a system resume to happen on device-induced wakeup
events even if the "soft" mechanism to prevent the system from
suspending is not enabled (that also helps to catch device-induced
wakeup events occurring during suspend transitions in progress).

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-05-05 22:54:28 +02:00
Rafael J. Wysocki
8a537ece3d PM / wakeup: Integrate mechanism to abort transitions in progress
The system wakeup framework is not very consistent with respect to
the way it handles suspend-to-idle and generally wakeup events
occurring during transitions to system low-power states.

First off, system transitions in progress are aborted by the event
reporting helpers like pm_wakeup_event() only if the wakeup_count
sysfs attribute is in use (as documented), but there are cases in
which system-wide transitions should be aborted even if that is
not the case.  For example, a wakeup signal from a designated
wakeup device during system-wide PM transition, it should cause
the transition to be aborted right away.

Moreover, there is a freeze_wake() call in wakeup_source_activate(),
but that really is only effective after suspend_freeze_state has
been set to FREEZE_STATE_ENTER by freeze_enter().  However, it
is very unlikely that wakeup_source_activate() will ever be called
at that time, as it could only be triggered by a IRQF_NO_SUSPEND
interrupt handler, so wakeups from suspend-to-idle don't really
occur in wakeup_source_activate().

At the same time there is a way to abort a system suspend in
progress (or wake up the system from suspend-to-idle), which is by
calling pm_system_wakeup(), but in turn that doesn't cause any
wakeup source objects to be activated, so it will not be covered
by wakeup source statistics and will not prevent the system from
suspending again immediately (in case autosleep is used, for
example).  Consequently, if anyone wants to abort system transitions
in progress and allow the wakeup_count mechanism to work, they need
to use both pm_system_wakeup() and pm_wakeup_event(), say, at the
same time which is awkward.

For the above reasons, make it possible to trigger
pm_system_wakeup() from within wakeup_source_activate() and
provide a new pm_wakeup_hard_event() helper to do so within the
wakeup framework.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-05-05 22:54:28 +02:00
Linus Torvalds
0be75179df Merge tag 'driver-core-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core updates from Greg KH:
 "Very tiny pull request for 4.12-rc1 for the driver core this time
  around.

  There are some documentation fixes, an eventpoll.h fixup to make it
  easier for the libc developers to take our header files directly, and
  some very minor driver core fixes and changes.

  All have been in linux-next for a very long time with no reported
  issues"

* tag 'driver-core-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  Revert "kref: double kref_put() in my_data_handler()"
  driver core: don't initialize 'parent' in device_add()
  drivers: base: dma-mapping: use nth_page helper
  Documentation/ABI: add information about cpu_capacity
  debugfs: set no_llseek in DEFINE_DEBUGFS_ATTRIBUTE
  eventpoll.h: add missing epoll event masks
  eventpoll.h: fix epoll event masks
2017-05-04 18:27:46 -07:00
Linus Torvalds
3cb6653552 Merge branch 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq updates from Thomas Gleixner:
 "Nothing exciting from the irq side for this merge window:

   - a new driver for a Mediatek SoC

   - ACPI support for ARM GICV3

   - support for shared nested interrupts

   - the usual pile of fixes and updates all over te place"

* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits)
  irqchip/mbigen: Fix return value check in mbigen_device_probe()
  irqchip/mips-gic: Replace static map with dynamic
  irqchip/mips-gic: Remove device IRQ domain
  irqchip/mips-gic: Separate IPI reservation & usage tracking
  genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQs
  genirq: Use cpumask_available() for check of cpumask variable
  cpumask: Add helper cpumask_available()
  irqchip/irq-imx-gpcv2: Clear OF_POPULATED flag
  irqchip/atmel-aic5: Handle suspend to RAM
  irqchip: Add Mediatek mtk-cirq driver
  dt-bindings: mtk-cirq: Add binding document
  irqchip/gic-v3-its: Add IORT hook for platform MSI support
  irqchip/mbigen: Add ACPI support
  irqchip/mbigen: Introduce mbigen_of_create_domain()
  irqchip/mbigen: Drop module owner
  platform-msi: Make platform_msi_create_device_domain() ACPI aware
  irqchip/gicv3-its: platform-msi: Scan MADT to create platform msi domain
  irqchip/gicv3-its: platform-msi: Refactor its_pmsi_init() to prepare for ACPI
  irqchip/gicv3-its: platform-msi: Refactor its_pmsi_prepare()
  irqchip/gic-v3-its: Keep the include header files in alphabetic order
  ...
2017-05-01 15:46:13 -07:00
Linus Torvalds
5fab10041b Merge tag 'devprop-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull generic device properties framework updates from Rafael Wysocki:
 "These add support for the ports and endpoints concepts, based on the
  existing DT support for them, to the generic device properties
  framework and update the ACPI _DSD properties code to recognize ports
  and endpoints accordingly.

  Specifics:

   - Extend the ACPI _DSD properties code and the generic device
     properties framework to support the concept of remote endponts
     (Mika Westerberg, Sakari Ailus).

   - Document the support for ports and endpoints in _DSD properties and
     extend the generic device properties framework to make it more
     suitable for the handling of ports and endpoints (Sakari Ailus)"

* tag 'devprop-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  device property: Read strings using string array reading functions
  device property: fwnode_property_read_string_array() returns nr of strings
  device property: Fix reading pset strings using array access functions
  device property: fwnode_property_read_string_array() may return -EILSEQ
  ACPI / DSD: Document references, ports and endpoints
  device property: Add fwnode_get_next_parent()
  device property: Add support for fwnode endpoints
  device property: Make dev_fwnode() public
  of: Add of_fwnode_handle() to convert device nodes to fwnode_handle
  device property: Add fwnode_handle_get()
  device property: Add support for remote endpoints
  ACPI / property: Add support for remote endpoints
  device property: Add fwnode_get_named_child_node()
  ACPI / property: Add fwnode_get_next_child_node()
  device property: Add fwnode_get_parent()
  ACPI / property: Add possiblity to retrieve parent firmware node
2017-05-01 14:18:05 -07:00
Sricharan R
5a1bb638d5 drivers: acpi: Handle IOMMU lookup failure with deferred probing or error
This is an equivalent to the DT's handling of the iommu master's probe
with deferred probing when the corrsponding iommu is not probed yet.
The lack of a registered IOMMU can be caused by the lack of a driver for
the IOMMU, the IOMMU device probe not having been performed yet, having
been deferred, or having failed.

The first case occurs when the firmware describes the bus master and
IOMMU topology correctly but no device driver exists for the IOMMU yet
or the device driver has not been compiled in. Return NULL, the caller
will configure the device without an IOMMU.

The second and third cases are handled by deferring the probe of the bus
master device which will eventually get reprobed after the IOMMU.

The last case is currently handled by deferring the probe of the bus
master device as well. A mechanism to either configure the bus master
device without an IOMMU or to fail the bus master device probe depending
on whether the IOMMU is optional or mandatory would be a good
enhancement.

Tested-by: Hanjun Guo <hanjun.guo@linaro.org>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
[Lorenzo: Added fixes for dma_coherent_mask overflow, acpi_dma_configure
          called multiple times for same device]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-04-20 16:31:08 +02:00
Laurent Pinchart
7b07cbefb6 iommu: of: Handle IOMMU lookup failure with deferred probing or error
Failures to look up an IOMMU when parsing the DT iommus property need to
be handled separately from the .of_xlate() failures to support deferred
probing.

The lack of a registered IOMMU can be caused by the lack of a driver for
the IOMMU, the IOMMU device probe not having been performed yet, having
been deferred, or having failed.

The first case occurs when the device tree describes the bus master and
IOMMU topology correctly but no device driver exists for the IOMMU yet
or the device driver has not been compiled in. Return NULL, the caller
will configure the device without an IOMMU.

The second and third cases are handled by deferring the probe of the bus
master device which will eventually get reprobed after the IOMMU.

The last case is currently handled by deferring the probe of the bus
master device as well. A mechanism to either configure the bus master
device without an IOMMU or to fail the bus master device probe depending
on whether the IOMMU is optional or mandatory would be a good
enhancement.

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Laurent Pichart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2017-04-20 16:31:07 +02:00