Add a simple helper to chroot with a kernel space file name and switch
the early init code over to it. Remove the now unused ksys_chroot.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Add a simple helper to chdir with a kernel space file name and switch
the early init code over to it. Remove the now unused ksys_chdir.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Like do_mount, but takes a kernel pointer for the destination path.
Switch over the mounts in the init code and devtmpfs to it, which
just happen to work due to the implicit set_fs(KERNEL_DS) during early
init right now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Split the main worker loop into a separate function. This allows
devtmpfsd_setup to be marked __init, which will allows us to call
__init routines for the setup work. devtmpfѕ itself needs a __ref
marker for that to work, and a comment explaining why it works.
Signed-off-by: Christoph Hellwig <hch@lst.de>
/sys/kernel/debug/devices_deferred property contains list of deferred devices.
This list does not contain reason why the driver deferred probe, the patch
improves it.
The natural place to set the reason is dev_err_probe function introduced
recently, ie. if dev_err_probe will be called with -EPROBE_DEFER instead of
printk the message will be attached to a deferred device and printed when user
reads devices_deferred property.
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Link: https://lore.kernel.org/r/20200713144324.23654-3-a.hajda@samsung.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
During probe every time driver gets resource it should usually check for
error printk some message if it is not -EPROBE_DEFER and return the error.
This pattern is simple but requires adding few lines after any resource
acquisition code, as a result it is often omitted or implemented only
partially.
dev_err_probe helps to replace such code sequences with simple call,
so code:
if (err != -EPROBE_DEFER)
dev_err(dev, ...);
return err;
becomes:
return dev_err_probe(dev, err, ...);
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Link: https://lore.kernel.org/r/20200713144324.23654-2-a.hajda@samsung.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 3451a495ef ("driver core: Establish order of operations for
device_add and device_del via bitflag") sought to prevent asynchronous
driver binding to a device which is being removed. It added a
per-device "dead" flag which is checked in the following code paths:
* asynchronous binding in __driver_attach_async_helper()
* synchronous binding in device_driver_attach()
* asynchronous binding in __device_attach_async_helper()
It did *not* check the flag upon:
* synchronous binding in __device_attach()
However __device_attach() may also be called asynchronously from:
deferred_probe_work_func()
bus_probe_device()
device_initial_probe()
__device_attach()
So if the commit's intention was to check the "dead" flag in all
asynchronous code paths, then a check is also necessary in
__device_attach(). Add the missing check.
Fixes: 3451a495ef ("driver core: Establish order of operations for device_add and device_del via bitflag")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: stable@vger.kernel.org # v5.1+
Cc: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Link: https://lore.kernel.org/r/de88a23a6fe0ef70f7cfd13c8aea9ab51b4edab6.1594214103.git.lukas@wunner.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Marek and Guenter reported that commit 287905e68d ("driver core:
Expose device link details in sysfs") caused sleeping/scheduling while
atomic warnings.
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:935
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 12, name: kworker/0:1
2 locks held by kworker/0:1/12:
#0: ee8074a8 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x174/0x7dc
#1: ee921f20 ((work_completion)(&sdp->work)){+.+.}-{0:0}, at: process_one_work+0x174/0x7dc
Preemption disabled at:
[<c01b10f0>] srcu_invoke_callbacks+0xc0/0x154
----- 8< ----- SNIP
[<c064590c>] (device_del) from [<c0645c9c>] (device_unregister+0x24/0x64)
[<c0645c9c>] (device_unregister) from [<c01b10fc>] (srcu_invoke_callbacks+0xcc/0x154)
[<c01b10fc>] (srcu_invoke_callbacks) from [<c01493c4>] (process_one_work+0x234/0x7dc)
[<c01493c4>] (process_one_work) from [<c01499b0>] (worker_thread+0x44/0x51c)
[<c01499b0>] (worker_thread) from [<c0150bf4>] (kthread+0x158/0x1a0)
[<c0150bf4>] (kthread) from [<c0100114>] (ret_from_fork+0x14/0x20)
Exception stack(0xee921fb0 to 0xee921ff8)
This was caused by the device link device being released in the context
of srcu_invoke_callbacks(). There is no need to wait till the RCU
callback to release the device link device. So release the device
earlier and move the call_srcu() into the device release code. That way,
the memory will get freed only after the device is released AND the RCU
callback is called.
Fixes: 287905e68d ("driver core: Expose device link details in sysfs")
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200716214523.2924704-1-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The following commit:
14533a16c4 ("thermal/cpu-cooling, sched/core: Move the arch_set_thermal_pressure() API to generic scheduler code")
moved the definition of arch_set_thermal_pressure() to sched/core.c, but
kept its declaration in linux/arch_topology.h. When building e.g. an x86
kernel with CONFIG_SCHED_THERMAL_PRESSURE=y, cpufreq_cooling.c ends up
getting the declaration of arch_set_thermal_pressure() from
include/linux/arch_topology.h, which is somewhat awkward.
On top of this, sched/core.c unconditionally defines
o The thermal_pressure percpu variable
o arch_set_thermal_pressure()
while arch_scale_thermal_pressure() does nothing unless redefined by the
architecture.
arch_*() functions are meant to be defined by architectures, so revert the
aforementioned commit and re-implement it in a way that keeps
arch_set_thermal_pressure() architecture-definable, and doesn't define the
thermal pressure percpu variable for kernels that don't need
it (CONFIG_SCHED_THERMAL_PRESSURE=n).
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200712165917.9168-2-valentin.schneider@arm.com
Pull regmap fixes from Mark Brown:
"A couple of substantial fixes here, one from Doug which fixes the
debugfs code for MMIO regmaps (fortunately not the common case) and
one from Marc fixing lookups of multiple regmaps for the same device
(a very unusual case).
There's also a fix for Kconfig to ensure we enable SoundWire properly"
* tag 'regmap-fix-v5.8-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: debugfs: Don't sleep while atomic for fast_io regmaps
regmap: add missing dependency on SoundWire
regmap: dev_get_regmap_match(): fix string comparison
If a regmap has "fast_io" set then its lock function uses a spinlock.
That doesn't work so well with the functions:
* regmap_cache_only_write_file()
* regmap_cache_bypass_write_file()
Both of the above functions have the pattern:
1. Lock the regmap.
2. Call:
debugfs_write_file_bool()
copy_from_user()
__might_fault()
__might_sleep()
Let's reorder things a bit so that we do all of our sleepable
functions before we grab the lock.
Fixes: d3dc5430d6 ("regmap: debugfs: Allow writes to cache state settings")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200715164611.1.I35b3533e8a80efde0cec1cc70f71e1e74b2fa0da@changeid
Signed-off-by: Mark Brown <broonie@kernel.org>
Udev rules that depend on the power/wakeup attribute don't get triggered
correctly if device_set_wakeup_capable is called after the device is
created. This can happen for several reasons (driver sets wakeup after
device is created, wakeup is changed on parent device, etc) and it seems
reasonable to emit a changed event when adding or removing attributes on
the device.
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This would be useful to check if a device is not probing because it's
waiting for a supplier to be added and then linked to before it can
probe.
To reduce sysfs clutter, this file is added only if it can ever be 1.
So, if fw_devlink is disabled or set to permissive, this file is not
added. Also, this file is removed once the device probes as it's no
longer relevant.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200521191800.136035-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This can be used to check if a device supports sync_state() callbacks
and therefore keeps resources left on by the bootloader enabled till all
its consumers have probed.
This can also be used to check if sync_state() has been called for a
device or whether it is still trying to keep resources enabled because
they were left enabled by the bootloader and all its consumers haven't
probed yet.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200521191800.136035-3-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
It's helpful to be able to look at device link details from sysfs. So,
expose it in sysfs.
Say device-A is supplier of device-B. These are the additional files
this patch would create:
/sys/class/devlink/device-A:device-B/
auto_remove_on
consumer/ -> .../device-B/
runtime_pm
status
supplier/ -> .../device-A/
sync_state_only
/sys/devices/.../device-A/
consumer:device-B/ -> /sys/class/devlink/device-A:device-B/
/sys/devices/.../device-B/
supplier:device-A/ -> /sys/class/devlink/device-A:device-B/
That way:
To get a list of all the device link in the system:
ls /sys/class/devlink/
To get the consumer names and links of a device:
ls -d /sys/devices/.../device-X/consumer:*
To get the supplier names and links of a device:
ls -d /sys/devices/.../device-X/supplier:*
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20200521191800.136035-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
With the earlier patch in this series, all devices that deferred probe
due to fw_devlink_pause() will have their probes delayed till the
deferred probe thread is kicked off during late_initcall. This will also
affect all their consumers.
This delayed probing in unnecessary. So this patch just keeps track of
the devices that had their probe deferred due to fw_devlink_pause() and
attempts to probe them once during fw_devlink_resume().
Fixes: 716a7a2596 ("driver core: fw_devlink: Add support for batching fwnode parsing")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200701194259.3337652-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The current deferred probe implementation can mess up suspend/resume
ordering if deferred probe thread is kicked off in parallel with the
main initcall thread (kernel_init thread) [1].
For example:
Say device-B is a consumer of device-A.
Initcall thread Deferred probe thread
=============== =====================
1. device-A is added.
2. device-B is added.
3. dpm_list is now [device-A, device-B].
4. driver-A defers probe of device-A.
5. device-A is moved to
end of dpm_list
6. dpm_list is now
[device-B, device-A]
7. driver-B is registereed and probes device-B.
8. dpm_list stays as [device-B, device-A].
The reverse order of dpm_list is used for suspend. So in this case
device-A would incorrectly get suspended before device-B.
Commit 716a7a2596 ("driver core: fw_devlink: Add support for batching
fwnode parsing") kicked off the deferred probe thread early during boot
to run in parallel with the initcall thread and caused suspend/resume
regressions. This patch removes the parallel run of the deferred probe
thread to avoid the suspend/resume regressions.
[1] - https://lore.kernel.org/lkml/CAGETcx8W96KAw-d_siTX4qHB_-7ddk0miYRDQeHE6E0_8qx-6Q@mail.gmail.com/
Fixes: 716a7a2596 ("driver core: fw_devlink: Add support for batching fwnode parsing")
Signed-off-by: Saravana Kannan <saravanak@google.com>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20200701194259.3337652-2-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The genpd infrastructure uses the terms master/slave, but such uses have
no external exposures (not even in Documentation/driver-api/pm/*) and are
not mandated by nor associated with any external specifications. Change
the language used through-out to parent/child.
There was one possible exception in the debugfs node
"pm_genpd/pm_genpd_summary" but its path has no hits outside of the
kernel itself when performing a code search[1], and it seems even this
single usage has been non-functional since it was introduced due to a
typo in the Python ("apend" instead of correct "append"). Fix the typo
while we're at it.
Link: https://codesearch.debian.net/ # [1]
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This function is used by dev_get_regmap() to retrieve a regmap for the
specified device. If the device has more than one regmap, the name parameter
can be used to specify one.
The code here uses a pointer comparison to check for equal strings. This
however will probably always fail, as the regmap->name is allocated via
kstrdup_const() from the regmap's config->name.
Fix this by using strcmp() instead.
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/r/20200703103315.267996-1-mkl@pengutronix.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Pull power management fixes from Rafael Wysocki:
"These fix a recent regression that broke suspend-to-idle on some x86
systems, fix the intel_pstate driver to correctly let the platform
firmware control CPU performance in some cases and add __init
annotations to a couple of functions.
Specifics:
- Make sure that the _TIF_POLLING_NRFLAG is clear before entering the
last phase of suspend-to-idle to avoid wakeup issues on some x86
systems (Chen Yu, Rafael Wysocki).
- Cover one more case in which the intel_pstate driver should let the
platform firmware control the CPU frequency and refuse to load
(Srinivas Pandruvada).
- Add __init annotations to 2 functions in the power management core
(Christophe JAILLET)"
* tag 'pm-5.8-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpuidle: Rearrange s2idle-specific idle state entry code
PM: sleep: core: mark 2 functions as __init to save some memory
cpufreq: intel_pstate: Add one more OOB control bit
PM: s2idle: Clear _TIF_POLLING_NRFLAG before suspend to idle
'early_resume_init()' and 'late_resume_init() 'are only called respectively
via 'early_resume_init' and 'late_resume_init'.
They can be marked as __init to save a few bytes of memory.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
[ rjw: Subject edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Pull regmap fixes from Mark Brown:
"A few small fixes, none of which are likely to have any substantial
impact here - the most substantial one is a fix for a long standing
memory leak on devices that use register patching which will only have
an impact if the device is removed and re-added"
* tag 'regmap-fix-v5.8-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap: Fix memory leak from regmap_register_patch
regmap: fix the kerneldoc for regmap_test_bits()
regmap: fix alignment issue
DT implementation of fw_devlink needs this function to detect cycles. So
make it available.
Signed-off-by: Saravana Kannan <saravanak@google.com>
Tested-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Rob Herring <robh@kernel.org>
