PM: sleep: Use sysfs_emit() and sysfs_emit_at() in "show" functions

As Documentation/filesystems/sysfs.rst suggested, show() should only use
sysfs_emit() or sysfs_emit_at() when formatting the value

PM: sleep: Use sysfs_emit() and sysfs_emit_at() in "show" functions

As Documentation/filesystems/sysfs.rst suggested, show() should only use
sysfs_emit() or sysfs_emit_at() when formatting the value to be returned
to user space.

No functional change intended.

Signed-off-by: Xueqin Luo <[email protected]>
Link: https://patch.msgid.link/[email protected]
[ rjw: Subject edit ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: sleep: stats: Use locking in dpm_save_failed_dev()

Because dpm_save_failed_dev() may be called simultaneously by multiple
failing device PM functions, the state of the suspend_stats fields
updat

PM: sleep: stats: Use locking in dpm_save_failed_dev()

Because dpm_save_failed_dev() may be called simultaneously by multiple
failing device PM functions, the state of the suspend_stats fields
updated by it may become inconsistent.

Prevent that from happening by using a lock in dpm_save_failed_dev().

Signed-off-by: Rafael J. Wysocki <[email protected]>
Reviewed-by: Stanislaw Gruszka <[email protected]>
Reviewed-by: Ulf Hansson <[email protected]>

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PM: sleep: stats: Define suspend_stats next to the code using it

It is not necessary to define struct suspend_stats in a header file and the
suspend_stats variable in the core device system-wide PM

PM: sleep: stats: Define suspend_stats next to the code using it

It is not necessary to define struct suspend_stats in a header file and the
suspend_stats variable in the core device system-wide PM code. They both
can be defined in kernel/power/main.c, next to the sysfs and debugfs code
accessing suspend_stats, which can be static.

Modify the code in question in accordance with the above observation and
replace the static inline functions manipulating suspend_stats with
regular ones defined in kernel/power/main.c.

While at it, move the enum suspend_stat_step to the end of suspend.h which
is a more suitable place for it.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <[email protected]>
Reviewed-by: Ulf Hansson <[email protected]>

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PM: sleep: stats: Use unsigned int for success and failure counters

Change the type of the "success" and "fail" fields in struct
suspend_stats to unsigned int, because they cannot be negative.

No i

PM: sleep: stats: Use unsigned int for success and failure counters

Change the type of the "success" and "fail" fields in struct
suspend_stats to unsigned int, because they cannot be negative.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <[email protected]>
Reviewed-by: Stanislaw Gruszka <[email protected]>
Reviewed-by: Ulf Hansson <[email protected]>

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PM: sleep: stats: Use an array of step failure counters

Instead of using a set of individual struct suspend_stats fields
representing suspend step failure counters, use an array of counters
indexed

PM: sleep: stats: Use an array of step failure counters

Instead of using a set of individual struct suspend_stats fields
representing suspend step failure counters, use an array of counters
indexed by enum suspend_stat_step for this purpose, which allows
dpm_save_failed_step() to increment the appropriate counter
automatically, so that its callers don't need to do that directly.

It also allows suspend_stats_show() to carry out a loop over the
counters array to print their values.

Because the counters cannot become negative, use unsigned int for
representing them.

The only user-observable impact of this change is a different
ordering of entries in the suspend_stats debugfs file which is not
expected to matter.

Signed-off-by: Rafael J. Wysocki <[email protected]>
Reviewed-by: Stanislaw Gruszka <[email protected]>
Reviewed-by: Ulf Hansson <[email protected]>

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PM: sleep: stats: Use array of suspend step names

Replace suspend_step_name() in the suspend statistics code with an array
of suspend step names which has fewer lines of code and less overhead.

Whi

PM: sleep: stats: Use array of suspend step names

Replace suspend_step_name() in the suspend statistics code with an array
of suspend step names which has fewer lines of code and less overhead.

While at it, remove two unnecessary line breaks in suspend_stats_show()
and adjust some white space in there to the kernel coding style for a
more consistent code layout.

No intentional functional impact.

Signed-off-by: Rafael J. Wysocki <[email protected]>
Reviewed-by: Stanislaw Gruszka <[email protected]>
Reviewed-by: Ulf Hansson <[email protected]>

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PM: sleep: Remove obsolete comment from unlock_system_sleep()

With the freezer changes introduced by commit f5d39b020809
("freezer,sched: Rewrite core freezer logic"), the comment in
unlock_system_s

PM: sleep: Remove obsolete comment from unlock_system_sleep()

With the freezer changes introduced by commit f5d39b020809
("freezer,sched: Rewrite core freezer logic"), the comment in
unlock_system_sleep() has become obsolete, there is no need to
retain it.

Signed-off-by: Kevin Hao <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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include/linux/suspend.h: Only show pm_pr_dbg messages at suspend/resume

All uses in the kernel are currently already oriented around
suspend/resume. As some other parts of the kernel may also use th

include/linux/suspend.h: Only show pm_pr_dbg messages at suspend/resume

All uses in the kernel are currently already oriented around
suspend/resume. As some other parts of the kernel may also use these
messages in functions that could also be used outside of
suspend/resume, only enable in suspend/resume path.

Signed-off-by: Mario Limonciello <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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mm: page_alloc: move pm_* function into power

pm_restrict_gfp_mask()/pm_restore_gfp_mask() only used in power, let's
move them out of page_alloc.c.

Adding a general gfp_has_io_fs() function which r

mm: page_alloc: move pm_* function into power

pm_restrict_gfp_mask()/pm_restore_gfp_mask() only used in power, let's
move them out of page_alloc.c.

Adding a general gfp_has_io_fs() function which return true if gfp with
both __GFP_IO and __GFP_FS flags, then use it inside of
pm_suspended_storage(), also the pm_suspended_storage() is moved into
suspend.h.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Kefeng Wang <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: "Huang, Ying" <[email protected]>
Cc: Iurii Zaikin <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Len Brown <[email protected]>
Cc: Luis Chamberlain <[email protected]>
Cc: Mike Rapoport (IBM) <[email protected]>
Cc: Oscar Salvador <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: Rafael J. Wysocki <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

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PM: Add sysfs files to represent time spent in hardware sleep state

Userspace can't easily discover how much of a sleep cycle was spent in a
hardware sleep state without using kernel tracing and ven

PM: Add sysfs files to represent time spent in hardware sleep state

Userspace can't easily discover how much of a sleep cycle was spent in a
hardware sleep state without using kernel tracing and vendor specific sysfs
or debugfs files.

To make this information more discoverable, introduce 3 new sysfs files:
1) The time spent in a hw sleep state for last cycle.
2) The time spent in a hw sleep state since the kernel booted
3) The maximum time that the hardware can report for a sleep cycle.
All of these files will be present only if the system supports s2idle.

Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Mario Limonciello <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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freezer,sched: Rewrite core freezer logic

Rewrite the core freezer to behave better wrt thawing and be simpler
in general.

By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensu

freezer,sched: Rewrite core freezer logic

Rewrite the core freezer to behave better wrt thawing and be simpler
in general.

By replacing PF_FROZEN with TASK_FROZEN, a special block state, it is
ensured frozen tasks stay frozen until thawed and don't randomly wake
up early, as is currently possible.

As such, it does away with PF_FROZEN and PF_FREEZER_SKIP, freeing up
two PF_flags (yay!).

Specifically; the current scheme works a little like:

freezer_do_not_count();
schedule();
freezer_count();

And either the task is blocked, or it lands in try_to_freezer()
through freezer_count(). Now, when it is blocked, the freezer
considers it frozen and continues.

However, on thawing, once pm_freezing is cleared, freezer_count()
stops working, and any random/spurious wakeup will let a task run
before its time.

That is, thawing tries to thaw things in explicit order; kernel
threads and workqueues before doing bringing SMP back before userspace
etc.. However due to the above mentioned races it is entirely possible
for userspace tasks to thaw (by accident) before SMP is back.

This can be a fatal problem in asymmetric ISA architectures (eg ARMv9)
where the userspace task requires a special CPU to run.

As said; replace this with a special task state TASK_FROZEN and add
the following state transitions:

TASK_FREEZABLE -> TASK_FROZEN
__TASK_STOPPED -> TASK_FROZEN
__TASK_TRACED -> TASK_FROZEN

The new TASK_FREEZABLE can be set on any state part of TASK_NORMAL
(IOW. TASK_INTERRUPTIBLE and TASK_UNINTERRUPTIBLE) -- any such state
is already required to deal with spurious wakeups and the freezer
causes one such when thawing the task (since the original state is
lost).

The special __TASK_{STOPPED,TRACED} states *can* be restored since
their canonical state is in ->jobctl.

With this, frozen tasks need an explicit TASK_FROZEN wakeup and are
free of undue (early / spurious) wakeups.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Ingo Molnar <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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freezer: Have {,un}lock_system_sleep() save/restore flags

Rafael explained that the reason for having both PF_NOFREEZE and
PF_FREEZER_SKIP is that {,un}lock_system_sleep() is callable from
kthread c

freezer: Have {,un}lock_system_sleep() save/restore flags

Rafael explained that the reason for having both PF_NOFREEZE and
PF_FREEZER_SKIP is that {,un}lock_system_sleep() is callable from
kthread context that has previously called set_freezable().

In preparation of merging the flags, have {,un}lock_system_slee() save
and restore current->flags.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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PM: CXL: Disable suspend

The CXL specification claims S3 support at a hardware level, but at a
system software level there are some missing pieces. Section 9.4 (CXL
2.0) rightly claims that "CXL mem

PM: CXL: Disable suspend

The CXL specification claims S3 support at a hardware level, but at a
system software level there are some missing pieces. Section 9.4 (CXL
2.0) rightly claims that "CXL mem adapters may need aux power to retain
memory context across S3", but there is no enumeration mechanism for the
OS to determine if a given adapter has that support. Moreover the save
state and resume image for the system may inadvertantly end up in a CXL
device that needs to be restored before the save state is recoverable.
I.e. a circular dependency that is not resolvable without a third party
save-area.

Arrange for the cxl_mem driver to fail S3 attempts. This still nominaly
allows for suspend, but requires unbinding all CXL memory devices before
the suspend to ensure the typical DRAM flow is taken. The cxl_mem unbind
flow is intended to also tear down all CXL memory regions associated
with a given cxl_memdev.

It is reasonable to assume that any device participating in a System RAM
range published in the EFI memory map is covered by aux power and
save-area outside the device itself. So this restriction can be
minimized in the future once pre-existing region enumeration support
arrives, and perhaps a spec update to clarify if the EFI memory map is
sufficent for determining the range of devices managed by
platform-firmware for S3 support.

Per Rafael, if the CXL configuration prevents suspend then it should
fail early before tasks are frozen, and mem_sleep should stop showing
'mem' as an option [1]. Effectively CXL augments the platform suspend
->valid() op since, for example, the ACPI ops are not aware of the CXL /
PCI dependencies. Given the split role of platform firmware vs OS
provisioned CXL memory it is up to the cxl_mem driver to determine if
the CXL configuration has elements that platform firmware may not be
prepared to restore.

Link: https://lore.kernel.org/r/CAJZ5v0hGVN_=3iU8OLpHY3Ak35T5+JcBM-qs8SbojKrpd0VXsA@mail.gmail.com [1]
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Pavel Machek <[email protected]>
Cc: Len Brown <[email protected]>
Reviewed-by: Rafael J. Wysocki <[email protected]>
Link: https://lore.kernel.org/r/165066828317.3907920.5690432272182042556.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <[email protected]>

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PM: sleep: enable dynamic debug support within pm_pr_dbg()

Currently pm_pr_dbg() is used to filter kernel pm debug messages based
on pm_debug_messages_on flag. The problem is if we enable/disable th

PM: sleep: enable dynamic debug support within pm_pr_dbg()

Currently pm_pr_dbg() is used to filter kernel pm debug messages based
on pm_debug_messages_on flag. The problem is if we enable/disable this
flag it will affect all pm_pr_dbg() calls at once, so we can't
individually control them.

This patch changes pm_pr_dbg() implementation as such:

- If pm_debug_messages_on is enabled, print the message.
- If pm_debug_messages_on is disabled and CONFIG_DYNAMIC_DEBUG is
enabled, only print the messages explicitly enabled on
/sys/kernel/debug/dynamic_debug/control.
- If pm_debug_messages_on is disabled and CONFIG_DYNAMIC_DEBUG is
disabled, don't print the message.

Signed-off-by: David Cohen <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: s2idle: ACPI: Fix wakeup interrupts handling

After commit e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race
related to the EC GPE") wakeup interrupts occurring immediately after
the one disca

PM: s2idle: ACPI: Fix wakeup interrupts handling

After commit e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race
related to the EC GPE") wakeup interrupts occurring immediately after
the one discarded by acpi_s2idle_wake() may be missed. Moreover, if
the SCI triggers again immediately after the rearming in
acpi_s2idle_wake(), that wakeup may be missed too.

The problem is that pm_system_irq_wakeup() only calls pm_system_wakeup()
when pm_wakeup_irq is 0, but that's not the case any more after the
interrupt causing acpi_s2idle_wake() to run until pm_wakeup_irq is
cleared by the pm_wakeup_clear() call in s2idle_loop(). However,
there may be wakeup interrupts occurring in that time frame and if
that happens, they will be missed.

To address that issue first move the clearing of pm_wakeup_irq to
the point at which it is known that the interrupt causing
acpi_s2idle_wake() to tun will be discarded, before rearming the SCI
for wakeup. Moreover, because that only reduces the size of the
time window in which the issue may manifest itself, allow
pm_system_irq_wakeup() to register two second wakeup interrupts in
a row and, when discarding the first one, replace it with the second
one. [Of course, this assumes that only one wakeup interrupt can be
discarded in one go, but currently that is the case and I am not
aware of any plans to change that.]

Fixes: e3728b50cd9b ("ACPI: PM: s2idle: Avoid possible race related to the EC GPE")
Cc: 5.4+ <[email protected]> # 5.4+
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: sleep: unmark 'state' functions as kernel-doc

Fix kernel-doc warnings in kernel/power/main.c by unmarking the
comment block as kernel-doc notation. This eliminates the following
kernel-doc warni

PM: sleep: unmark 'state' functions as kernel-doc

Fix kernel-doc warnings in kernel/power/main.c by unmarking the
comment block as kernel-doc notation. This eliminates the following
kernel-doc warnings:

kernel/power/main.c:593: warning: expecting prototype for state(). Prototype was for state_show() instead
kernel/power/main.c:593: warning: Function parameter or member 'kobj' not described in 'state_show'
kernel/power/main.c:593: warning: Function parameter or member 'attr' not described in 'state_show'
kernel/power/main.c:593: warning: Function parameter or member 'buf' not described in 'state_show'

Signed-off-by: Randy Dunlap <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: sleep: Constify static struct attribute_group

The only usage of suspend_attr_group is to put its address in an
array of pointers to const attribute_group structs.

Make it const to allow the com

PM: sleep: Constify static struct attribute_group

The only usage of suspend_attr_group is to put its address in an
array of pointers to const attribute_group structs.

Make it const to allow the compiler to put it into read-only memory.

Signed-off-by: Rikard Falkeborn <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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notifier: Fix broken error handling pattern

The current notifiers have the following error handling pattern all
over the place:

int err, nr;

err = __foo_notifier_call_chain(&chain, val_up, v, -1

notifier: Fix broken error handling pattern

The current notifiers have the following error handling pattern all
over the place:

int err, nr;

err = __foo_notifier_call_chain(&chain, val_up, v, -1, &nr);
if (err & NOTIFIER_STOP_MASK)
__foo_notifier_call_chain(&chain, val_down, v, nr-1, NULL)

And aside from the endless repetition thereof, it is broken. Consider
blocking notifiers; both calls take and drop the rwsem, this means
that the notifier list can change in between the two calls, making @nr
meaningless.

Fix this by replacing all the __foo_notifier_call_chain() functions
with foo_notifier_call_chain_robust() that embeds the above pattern,
but ensures it is inside a single lock region.

Note: I switched atomic_notifier_call_chain_robust() to use
the spinlock, since RCU cannot provide the guarantee
required for the recovery.

Note: software_resume() error handling was broken afaict.

Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

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PM: sleep: Add pm_debug_messages kernel command line option

Debug messages from the system suspend/hibernation infrastructure
are disabled by default, and can only be enabled after the system
has bo

PM: sleep: Add pm_debug_messages kernel command line option

Debug messages from the system suspend/hibernation infrastructure
are disabled by default, and can only be enabled after the system
has boot up via /sys/power/pm_debug_messages.

This makes the hibernation resume hard to track as it involves system
boot up across hibernation. There's no chance for software_resume()
to track the resume process, for example.

Add a kernel command line option to set pm_debug_messages during
boot up.

Signed-off-by: Chen Yu <[email protected]>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior

The sysfs attribute `/sys/power/sync_on_suspend` controls, whether or not
filesystems are synced by the kernel before syste

PM: suspend: Add sysfs attribute to control the "sync on suspend" behavior

The sysfs attribute `/sys/power/sync_on_suspend` controls, whether or not
filesystems are synced by the kernel before system suspend.

Congruously, the behaviour of build-time switch CONFIG_SUSPEND_SKIP_SYNC
is slightly changed: It now defines the run-tim default for the new sysfs
attribute `/sys/power/sync_on_suspend`.

The run-time attribute is added because the existing corresponding
build-time Kconfig flag for (`CONFIG_SUSPEND_SKIP_SYNC`) is not flexible
enough. E.g. Linux distributions that provide pre-compiled kernels
usually want to stick with the default (sync filesystems before suspend)
but under special conditions this needs to be changed.

One example for such a special condition is user-space handling of
suspending block devices (e.g. using `cryptsetup luksSuspend` or `dmsetup
suspend`) before system suspend. The Kernel trying to sync filesystems
after the underlying block device already got suspended obviously leads
to dead-locks. Be aware that you have to take care of the filesystem sync
yourself before suspending the system in those scenarios.

Signed-off-by: Jonas Meurer <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: sleep: include <linux/pm_runtime.h> for pm_wq

Include the <linux/runtime_pm.h> for the definition of
pm_wq to avoid the following warning:

kernel/power/main.c:890:25: warning: symbol 'pm_wq' wa

PM: sleep: include <linux/pm_runtime.h> for pm_wq

Include the <linux/runtime_pm.h> for the definition of
pm_wq to avoid the following warning:

kernel/power/main.c:890:25: warning: symbol 'pm_wq' was not declared. Should it be static?

Signed-off-by: Ben Dooks <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM: sleep: Replace strncmp() with str_has_prefix()

Use str_has_prefix() instead of strncmp() which is less
straightforward in decode_state().

Signed-off-by: Chuhong Yuan <[email protected]>
[ rj

PM: sleep: Replace strncmp() with str_has_prefix()

Use str_has_prefix() instead of strncmp() which is less
straightforward in decode_state().

Signed-off-by: Chuhong Yuan <[email protected]>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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PM/sleep: Expose suspend stats in sysfs

Userspace can get suspend stats from the suspend stats debugfs node.
Since debugfs doesn't have stable ABI, expose suspend stats in
sysfs under /sys/power/sus

PM/sleep: Expose suspend stats in sysfs

Userspace can get suspend stats from the suspend stats debugfs node.
Since debugfs doesn't have stable ABI, expose suspend stats in
sysfs under /sys/power/suspend_stats.

Signed-off-by: Kalesh Singh <[email protected]>
Reviewed-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428

Based on 1 normalized pattern(s):

this file is released under the gplv2

extracted by the scancode license scanner the SPDX lice

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428

Based on 1 normalized pattern(s):

this file is released under the gplv2

extracted by the scancode license scanner the SPDX license identifier

GPL-2.0-only

has been chosen to replace the boilerplate/reference in 68 file(s).

Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Armijn Hemel <[email protected]>
Reviewed-by: Allison Randal <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

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PM / sleep: Measure the time of filesystems syncing

Measure the filesystems sync time during system sleep more precisely.

Among other things, this allows the pr_cont() to be dropped from
ksys_sync_

PM / sleep: Measure the time of filesystems syncing

Measure the filesystems sync time during system sleep more precisely.

Among other things, this allows the pr_cont() to be dropped from
ksys_sync_helper() and makes automatic system suspend and hibernation
profiling somewhat more straightforward.

Signed-off-by: Harry Pan <[email protected]>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <[email protected]>

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