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 <rafael.j.wysocki@intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

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 <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

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 <rafael.j.wysocki@intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

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 <rafael.j.wysocki@intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

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 <rafael.j.wysocki@intel.com>
Reviewed-by: Stanislaw Gruszka <stanislaw.gruszka@linux.intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>

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 <haokexin@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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 <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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/20230516063821.121844-11-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Iurii Zaikin <yzaikin@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Len Brown <len.brown@intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Rafael J. Wysocki <rafael@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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 <hdegoede@redhat.com>
Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114649.055452969@infradead.org

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) <peterz@infradead.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20220822114648.725003428@infradead.org

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" <rafael@kernel.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <len.brown@intel.com>
Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/165066828317.3907920.5690432272182042556.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

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 <dacohen@pm.me>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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+ <stable@vger.kernel.org> # 5.4+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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 <rdunlap@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.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 <rikard.falkeborn@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Link: https://lore.kernel.org/r/20200818135804.325626653@infradead.org

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 <yu.c.chen@intel.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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 <jonas@freesources.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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 <ben.dooks@codethink.co.uk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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 <hslester96@gmail.com>
[ rjw: Subject & changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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 <kaleshsingh@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

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 <tglx@linutronix.de>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190114.292346262@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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 <harry.pan@intel.com>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: Refactor filesystems sync to reduce duplication

Create a common helper to sync filesystems for system suspend and
hibernation.

Signed-off-by: Harry Pan <harry.pan@intel.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
[ rjw: Changelog ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: convert to DEFINE_SHOW_ATTRIBUTE

Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / reboot: Eliminate race between reboot and suspend

At present, "systemctl suspend" and "shutdown" can run in parrallel. A
system can suspend after devices_shutdown(), and resume. Then the shutdown
task goes on to power off. This causes many devices are not really shut
off. Hence replacing reboot_mutex with system_transition_mutex (renamed
from pm_mutex) to achieve the exclusion. The renaming of pm_mutex as
system_transition_mutex can be better to reflect the purpose of the mutex.

Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

fix a series of Documentation/ broken file name references

As files move around, their previous links break. Fix the
references for them.

Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Jonathan Corbet <corbet@lwn.net>

PM / sleep: Make lock/unlock_system_sleep() available to kernel modules

Since pm_mutex is not exported using lock/unlock_system_sleep() from
inside a kernel module causes a "pm_mutex undefined" linker error.
Hence move lock/unlock_system_sleep() into kernel/power/main.c and
export these.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

ACPI / PM: Check low power idle constraints for debug only

For SoC to achieve its lowest power platform idle state a set of hardware
preconditions must be met. These preconditions or constraints can be
obtained by issuing a device specific method (_DSM) with function "1".
Refer to the document provided in the link below.

Here during initialization (from attach() callback of LPS0 device), invoke
function 1 to get the device constraints. Each enabled constraint is
stored in a table.

The devices in this table are used to check whether they were in required
minimum state, while entering suspend. This check is done from platform
freeze wake() callback, only when /sys/power/pm_debug_messages attribute
is non zero.

If any constraint is not met and device is ACPI power managed then it
prints the device information to kernel logs.

Also if debug is enabled in acpi/sleep.c, the constraint table and state
of each device on wake is dumped in kernel logs.

Since pm_debug_messages_on setting is used as condition to check
constraints outside kernel/power/main.c, pm_debug_messages_on is changed
to a global variable.

Link: http://www.uefi.org/sites/default/files/resources/Intel_ACPI_Low_Power_S0_Idle.pdf
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: Put pm_test under CONFIG_PM_SLEEP_DEBUG

The pm_test sysfs attribute is under CONFIG_PM_DEBUG, but it doesn't
make sense to provide it if CONFIG_PM_SLEEP is unset, so put it under
CONFIG_PM_SLEEP_DEBUG instead.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / timekeeping: Print debug messages when requested

The messages printed by tk_debug_account_sleep_time() are basically
useful for system sleep debugging, so print them only when the other
debug messages from the core suspend/hibernate code are enabled.

While at it, make it clear that the messages from
tk_debug_account_sleep_time() are about timekeeping suspend
duration, because in general timekeeping may be suspeded and
resumed for multiple times during one system suspend-resume cycle.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: Do not print debug messages by default

Debug messages from the system suspend/hibernation infrastructure can
fill up the entire kernel log buffer in some cases and anyway they
are only useful for debugging. They depend on CONFIG_PM_DEBUG, but
that is set as a rule as some generally useful diagnostic facilities
depend on it too.

For this reason, avoid printing those messages by default, but make
it possible to turn them on as needed with the help of a new sysfs
attribute under /sys/power/.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: constify attribute_group structures

attribute_groups are not supposed to change at runtime. All functions
working with attribute_groups provided by <linux/sysfs.h> work with const
attribute_group. So mark the non-const structs as const.

File size before:
text data bss dec hex filename
3802 624 32 4458 116a kernel/power/main.o

File size After adding 'const':
text data bss dec hex filename
3866 560 32 4458 116a kernel/power/main.o

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: System sleep state selection interface rework

There are systems in which the platform doesn't support any special
sleep states, so suspend-to-idle (PM_SUSPEND_FREEZE) is the only
available system sleep state. However, some user space frameworks
only use the "mem" and (sometimes) "standby" sleep state labels, so
the users of those systems need to modify user space in order to be
able to use system suspend at all and that may be a pain in practice.

Commit 0399d4db3edf (PM / sleep: Introduce command line argument for
sleep state enumeration) attempted to address this problem by adding
a command line argument to change the meaning of the "mem" string in
/sys/power/state to make it trigger suspend-to-idle (instead of
suspend-to-RAM).

However, there also are systems in which the platform does support
special sleep states, but suspend-to-idle is the preferred one anyway
(it even may save more energy than the platform-provided sleep states
in some cases) and the above commit doesn't help in those cases.

For this reason, rework the system sleep state selection interface
again (but preserve backwards compatibiliby). Namely, add a new
sysfs file, /sys/power/mem_sleep, that will control the system
suspend mode triggered by writing "mem" to /sys/power/state (in
analogy with what /sys/power/disk does for hibernation). Make it
select suspend-to-RAM ("deep" sleep) by default (if supported) and
fall back to suspend-to-idle ("s2idle") otherwise and add a new
command line argument, mem_sleep_default, allowing that default to
be overridden if need be.

At the same time, drop the relative_sleep_states command line
argument that doesn't make sense any more.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Tested-by: Mario Limonciello <mario.limonciello@dell.com>

PM / sleep: enable suspend-to-idle even without registered suspend_ops

Suspend-to-idle (aka the "freeze" sleep state) is a system sleep state
in which all of the processors enter deepest possible idle state and
wait for interrupts right after suspending all the devices.

There is no hard requirement for a platform to support and register
platform specific suspend_ops to enter suspend-to-idle/freeze state.
Only deeper system sleep states like PM_SUSPEND_STANDBY and
PM_SUSPEND_MEM rely on such low level support/implementation.

suspend-to-idle can be entered as along as all the devices can be
suspended. This patch enables the support for suspend-to-idle even on
systems that don't have any low level support for deeper system sleep
states and/or don't register any platform specific suspend_ops.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Andy Gross <andy.gross@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: make PM notifiers called symmetrically

This makes pm notifier PREPARE/POST symmetrical: if PREPARE
fails, we will only undo what ever happened on PREPARE.

It fixes the unbalanced CPU hotplug enable in CPU PM notifier.

Signed-off-by: Lianwei Wang <lianwei.wang@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: Add support for read-only sysfs attributes

Some sysfs attributes in /sys/power/ should really be read-only,
so add support for that, convert those attributes to read-only
and drop the stub .show() routines from them.

Original-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: Report interrupt that caused system wakeup

Add a sysfs attribute, /sys/power/pm_wakeup_irq, reporting the IRQ
number of the first wakeup interrupt (that is, the first interrupt
from an IRQ line armed for system wakeup) seen by the kernel during
the most recent system suspend/resume cycle.

This feature will be useful for system wakeup diagnostics of
spurious wakeup interrupts.

Signed-off-by: Alexandra Yates <alexandra.yates@linux.intel.com>
[ rjw: Fixed up pm_wakeup_irq definition ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: Fix symbol name in a comment in kernel/power/main.c

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: add pm-trace support for suspending phase

Occasionally, the system can't come back up after suspend/resume
due to problems of device suspending phase. This patch make
PM_TRACE infrastructure cover device suspending phase of
suspend/resume process, and the information in RTC can tell
developers which device suspending function make system hang.

Signed-off-by: Zhonghui Fu <zhonghui.fu@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM: Create PM workqueue if runtime PM is not configured too

The PM workqueue is going to be used by ACPI PM notify handlers
regardless of whether or not runtime PM is configured, so move
it out of #ifdef CONFIG_PM_RUNTIME.

Do that in three places in the ACPI device PM code.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: Simplify sleep states sysfs interface code

Simplify the sleep states sysfs interface /sys/power/state code by
redefining pm_states[] as an array of pointers to constant strings
such that only the entries corresponding to valid states are set.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / hibernate: introduce "nohibernate" boot parameter

To support using kernel features that are not compatible with hibernation,
this creates the "nohibernate" kernel boot parameter to disable both
hibernation and resume. This allows hibernation support to be a boot-time
choice instead of only a compile-time choice.

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: Introduce command line argument for sleep state enumeration

On some systems the platform doesn't support neither
PM_SUSPEND_MEM nor PM_SUSPEND_STANDBY, so PM_SUSPEND_FREEZE is the
only available system sleep state. However, some user space frameworks
only use the "mem" and (sometimes) "standby" sleep state labels, so
the users of those systems need to modify user space in order to be
able to use system suspend at all and that is not always possible.

For this reason, add a new kernel command line argument,
relative_sleep_states, allowing the users of those systems to change
the way in which the kernel assigns labels to system sleep states.
Namely, for relative_sleep_states=1, the "mem", "standby" and "freeze"
labels will enumerate the available system sleem states from the
deepest to the shallowest, respectively, so that "mem" is always
present in /sys/power/state and the other state strings may or may
not be presend depending on what is supported by the platform.

Update system sleep states documentation to reflect this change.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: Use valid_state() for platform-dependent sleep states only

Use the observation that, for platform-dependent sleep states
(PM_SUSPEND_STANDBY, PM_SUSPEND_MEM), a given state is either
always supported or always unsupported and store that information
in pm_states[] instead of calling valid_state() every time we
need to check it.

Also do not use valid_state() for PM_SUSPEND_FREEZE, which is always
valid, and move the pm_test_level validity check for PM_SUSPEND_FREEZE
directly into enter_state().

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sleep: Add state field to pm_states[] entries

To allow sleep states corresponding to the "mem", "standby" and
"freeze" lables to be different from the pm_states[] indexes of
those strings, introduce struct pm_sleep_state, consisting of
a string label and a state number, and turn pm_states[] into an
array of objects of that type.

This modification should not lead to any functional changes.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM: Add missing "freeze" state

Fix descriptions of /sys/power/state in the documentation and in
a code comment.

Signed-off-by: Geert Uytterhoeven <geert+renesas@linux-m68k.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
[rjw: Changelog]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / Sleep: Warn about system time after resume with pm_trace

pm_trace uses the system's Real Time Clock (RTC) to save the magic
number. The reason for this is that the RTC is the only reliably
available piece of hardware during resume operations where a value
can be set that will survive a reboot.

Consequence is that after a resume (even if it is successful) your
system clock will have a value corresponding to the magic number
instead of the correct date/time! It is therefore advisable to use
a program like ntp-date or rdate to reset the correct date/time from
an external time source when using this trace option.

There is no run-time message to warn users of the consequences of
enabling pm_trace. Adding a warning message to pm_trace_store()
will serve as a reminder to users to set the system date and time
after resume.

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / Sleep: Print last wakeup source on failed wakeup_count write

Commit a938da06 introduced a useful little log message to tell
users/debuggers which wakeup source aborted a suspend. However,
this message is only printed if the abort happens during the
in-kernel suspend path (after writing /sys/power/state).

The full specification of the /sys/power/wakeup_count facility
allows user-space power managers to double-check if wakeups have
already happened before it actually tries to suspend (e.g. while it
was running user-space pre-suspend hooks), by writing the last known
wakeup_count value to /sys/power/wakeup_count. This patch changes
the sysfs handler for that node to also print said log message if
that write fails, so that we can figure out the offending wakeup
source for both kinds of suspend aborts.

Signed-off-by: Julius Werner <jwerner@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

suspend: enable freeze timeout configuration through sys

At present, the value of timeout for freezing is 20s, which is
meaningless in case that one thread is frozen with mutex locked
and another thread is trying to lock the mutex, as this time of
freezing will fail unavoidably.
And if there is no new wakeup event registered, the system will
waste at most 20s for such meaningless trying of freezing.

With this patch, the value of timeout can be configured to smaller
value, so such meaningless trying of freezing will be aborted in
earlier time, and later freezing can be also triggered in earlier
time. And more power will be saved.
In normal case on mobile phone, it costs real little time to freeze
processes. On some platform, it only costs about 20ms to freeze
user space processes and 10ms to freeze kernel freezable threads.

Signed-off-by: Liu Chuansheng <chuansheng.liu@intel.com>
Signed-off-by: Li Fei <fei.li@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM: Introduce suspend state PM_SUSPEND_FREEZE

PM_SUSPEND_FREEZE state is a general state that
does not need any platform specific support, it equals
frozen processes + suspended devices + idle processors.

Compared with PM_SUSPEND_MEMORY,
PM_SUSPEND_FREEZE saves less power
because the system is still in a running state.
PM_SUSPEND_FREEZE has less resume latency because it does not
touch BIOS, and the processors are in idle state.

Compared with RTPM/idle,
PM_SUSPEND_FREEZE saves more power as
1. the processor has longer sleep time because processes are frozen.
The deeper c-state the processor supports, more power saving we can get.
2. PM_SUSPEND_FREEZE uses system suspend code path, thus we can get
more power saving from the devices that does not have good RTPM support.

This state is useful for
1) platforms that do not have STR, or have a broken STR.
2) platforms that have an extremely low power idle state,
which can be used to replace STR.

The following describes how PM_SUSPEND_FREEZE state works.
1. echo freeze > /sys/power/state
2. the processes are frozen.
3. all the devices are suspended.
4. all the processors are blocked by a wait queue
5. all the processors idles and enters (Deep) c-state.
6. an interrupt fires.
7. a processor is woken up and handles the irq.
8. if it is a general event,
a) the irq handler runs and quites.
b) goto step 4.
9. if it is a real wake event, say, power button pressing, keyboard touch, mouse moving,
a) the irq handler runs and activate the wakeup source
b) wakeup_source_activate() notifies the wait queue.
c) system starts resuming from PM_SUSPEND_FREEZE
10. all the devices are resumed.
11. all the processes are unfrozen.
12. system is back to working.

Known Issue:
The wakeup of this new PM_SUSPEND_FREEZE state may behave differently
from the previous suspend state.
Take ACPI platform for example, there are some GPEs that only enabled
when the system is in sleep state, to wake the system backk from S3/S4.
But we are not touching these GPEs during transition to PM_SUSPEND_FREEZE.
This means we may lose some wake event.
But on the other hand, as we do not disable all the Interrupts during
PM_SUSPEND_FREEZE, we may get some extra "wakeup" Interrupts, that are
not available for S3/S4.

The patches has been tested on an old Sony laptop, and here are the results:

Average Power:
1. RPTM/idle for half an hour:
14.8W, 12.6W, 14.1W, 12.5W, 14.4W, 13.2W, 12.9W
2. Freeze for half an hour:
11W, 10.4W, 9.4W, 11.3W 10.5W
3. RTPM/idle for three hours:
11.6W
4. Freeze for three hours:
10W
5. Suspend to Memory:
0.5~0.9W

Average Resume Latency:
1. RTPM/idle with a black screen: (From pressing keyboard to screen back)
Less than 0.2s
2. Freeze: (From pressing power button to screen back)
2.50s
3. Suspend to Memory: (From pressing power button to screen back)
4.33s

>From the results, we can see that all the platforms should benefit from
this patch, even if it does not have Low Power S0.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / sysfs: replace strict_str* with kstrto*

Replace strict_strtoul() with kstrtoul() in pm_async_store() and
pm_qos_power_write().

[rjw: Modified subject and changelog.]

Signed-off-by: Daniel Walter <sahne@0x90.at>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

PM / Sleep: Separate printing suspend times from initcall_debug

Change the behavior of the newly introduced
/sys/power/pm_print_times attribute so that its initial value
depends on initcall_debug, but setting it to 0 will cause device
suspend/resume times not to be printed, even if initcall_debug has
been set. This way, the people who use initcall_debug for reasons
other than PM debugging will be able to switch the suspend/resume
times printing off, if need be.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

PM / Sleep: add knob for printing device resume times

Added a new knob called /sys/power/pm_print_times. Setting it to 1
enables printing of time taken by devices to suspend and resume.
Setting it to 0 disables this printing (unless overridden by
initcall_debug kernel command line option).

Signed-off-by: Sameer Nanda <snanda@chromium.org>
Acked-by: Greg KH <gregkh@linuxfoundation.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM / Sleep: Fix a mistake in a conditional in autosleep_store()

The condition check in autosleep_store() is incorrect and prevents
/sys/power/autosleep from working as advertised. Fix that.

[rjw: Added the changelog.]

Signed-off-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM / Sleep: Add user space interface for manipulating wakeup sources, v3

Android allows user space to manipulate wakelocks using two
sysfs file located in /sys/power/, wake_lock and wake_unlock.
Writing a wakelock name and optionally a timeout to the wake_lock
file causes the wakelock whose name was written to be acquired (it
is created before is necessary), optionally with the given timeout.
Writing the name of a wakelock to wake_unlock causes that wakelock
to be released.

Implement an analogous interface for user space using wakeup sources.
Add the /sys/power/wake_lock and /sys/power/wake_unlock files
allowing user space to create, activate and deactivate wakeup
sources, such that writing a name and optionally a timeout to
wake_lock causes the wakeup source of that name to be activated,
optionally with the given timeout. If that wakeup source doesn't
exist, it will be created and then activated. Writing a name to
wake_unlock causes the wakeup source of that name, if there is one,
to be deactivated. Wakeup sources created with the help of
wake_lock that haven't been used for more than 5 minutes are garbage
collected and destroyed. Moreover, there can be only WL_NUMBER_LIMIT
wakeup sources created with the help of wake_lock present at a time.

The data type used to track wakeup sources created by user space is
called "struct wakelock" to indicate the origins of this feature.

This version of the patch includes an rbtree manipulation fix from John Stultz.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NeilBrown <neilb@suse.de>

PM / Sleep: Implement opportunistic sleep, v2

Introduce a mechanism by which the kernel can trigger global
transitions to a sleep state chosen by user space if there are no
active wakeup sources.

It consists of a new sysfs attribute, /sys/power/autosleep, that
can be written one of the strings returned by reads from
/sys/power/state, an ordered workqueue and a work item carrying out
the "suspend" operations. If a string representing the system's
sleep state is written to /sys/power/autosleep, the work item
triggering transitions to that state is queued up and it requeues
itself after every execution until user space writes "off" to
/sys/power/autosleep.

That work item enables the detection of wakeup events using the
functions already defined in drivers/base/power/wakeup.c (with one
small modification) and calls either pm_suspend(), or hibernate() to
put the system into a sleep state. If a wakeup event is reported
while the transition is in progress, it will abort the transition and
the "system suspend" work item will be queued up again.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: NeilBrown <neilb@suse.de>

PM / Sleep: Make enter_state() in kernel/power/suspend.c static

The enter_state() function in kernel/power/suspend.c should be
static and state_store() in kernel/power/suspend.c should call
pm_suspend() instead of it, so make that happen (which also reduces
code duplication related to suspend statistics).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>

PM / Suspend: Avoid code duplication in suspend statistics update

The code
if (error) {
suspend_stats.fail++;
dpm_save_failed_errno(error);
} else
suspend_stats.success++;

Appears in the kernel/power/main.c and kernel/power/suspend.c.

This patch just creates a new function to avoid duplicated code.

Suggested-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Marcos Paulo de Souza <marcos.mage@gmail.com>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM / Sleep: Introduce "late suspend" and "early resume" of devices

The current device suspend/resume phases during system-wide power
transitions appear to be insufficient for some platforms that want
to use the same callback routines for saving device states and
related operations during runtime suspend/resume as well as during
system suspend/resume. In principle, they could point their
.suspend_noirq() and .resume_noirq() to the same callback routines
as their .runtime_suspend() and .runtime_resume(), respectively,
but at least some of them require device interrupts to be enabled
while the code in those routines is running.

It also makes sense to have device suspend-resume callbacks that will
be executed with runtime PM disabled and with device interrupts
enabled in case someone needs to run some special code in that
context during system-wide power transitions.

Apart from this, .suspend_noirq() and .resume_noirq() were introduced
as a workaround for drivers using shared interrupts and failing to
prevent their interrupt handlers from accessing suspended hardware.
It appears to be better not to use them for other porposes, or we may
have to deal with some serious confusion (which seems to be happening
already).

For the above reasons, introduce new device suspend/resume phases,
"late suspend" and "early resume" (and analogously for hibernation)
whose callback will be executed with runtime PM disabled and with
device interrupts enabled and whose callback pointers generally may
point to runtime suspend/resume routines.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>

PM / Sleep: Replace mutex_[un]lock(&pm_mutex) with [un]lock_system_sleep()

Using [un]lock_system_sleep() is safer than directly using mutex_[un]lock()
on 'pm_mutex', since the latter could lead to freezing failures. Hence convert
all the present users of mutex_[un]lock(&pm_mutex) to use these safe APIs
instead.

Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM: Fix indentation and remove extraneous whitespaces in kernel/power/main.c

Lack of proper indentation of the goto statement decreases the readability
of code significantly. In fact, this made me look twice at the code to check
whether it really does what it should be doing. Fix this.

And in the same file, there are some extra whitespaces. Get rid of them too.

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM / Suspend: Fix bug in suspend statistics update

After commit 2a77c46de1e3dace73745015635ebbc648eca69c
(PM / Suspend: Add statistics debugfs file for suspend to RAM)
a missing pair of braces inside the state_store() function causes even
invalid arguments to suspend to be wrongly treated as failed suspend
attempts. Fix this.

[rjw: Put the hash/subject of the buggy commit into the changelog.]

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructure

These files were getting <linux/module.h> via an implicit non-obvious
path, but we want to crush those out of existence since they cost
time during compiles of processing thousands of lines of headers
for no reason. Give them the lightweight header that just contains
the EXPORT_SYMBOL infrastructure.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

PM: Fix build issue in main.c for CONFIG_PM_SLEEP unset

Suspend statistics should depend on CONFIG_PM_SLEEP, so make that
happen.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM / Suspend: Add statistics debugfs file for suspend to RAM

Record S3 failure time about each reason and the latest two failed
devices' names in S3 progress.
We can check it through 'suspend_stats' entry in debugfs.

The motivation of the patch:

We are enabling power features on Medfield. Comparing with PC/notebook,
a mobile enters/exits suspend-2-ram (we call it s3 on Medfield) far
more frequently. If it can't enter suspend-2-ram in time, the power
might be used up soon.

We often find sometimes, a device suspend fails. Then, system retries
s3 over and over again. As display is off, testers and developers
don't know what happens.

Some testers and developers complain they don't know if system
tries suspend-2-ram, and what device fails to suspend. They need
such info for a quick check. The patch adds suspend_stats under
debugfs for users to check suspend to RAM statistics quickly.

If not using this patch, we have other methods to get info about
what device fails. One is to turn on CONFIG_PM_DEBUG, but users
would get too much info and testers need recompile the system.

In addition, dynamic debug is another good tool to dump debug info.
But it still doesn't match our utilization scenario closely.
1) user need write a user space parser to process the syslog output;
2) Our testing scenario is we leave the mobile for at least hours.
Then, check its status. No serial console available during the
testing. One is because console would be suspended, and the other
is serial console connecting with spi or HSU devices would consume
power. These devices are powered off at suspend-2-ram.

Signed-off-by: ShuoX Liu <shuox.liu@intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM: Improve error code of pm_notifier_call_chain()

This enables pm_notifier_call_chain() to get the actual error code
in the callback rather than always assume -EINVAL by converting all
PM notifier calls to return encapsulate error code with
notifier_from_errno().

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM / Hibernate: Add sysfs knob to control size of memory for drivers

Martin reports that on his system hibernation occasionally fails due
to the lack of memory, because the radeon driver apparently allocates
too much of it during the device freeze stage. It turns out that the
amount of memory allocated by radeon during hibernation (and
presumably during system suspend too) depends on the utilization of
the GPU (e.g. hibernating while there are two KDE 4 sessions with
compositing enabled causes radeon to allocate more memory than for
one KDE 4 session).

In principle it should be possible to use image_size to make the
memory preallocation mechanism free enough memory for the radeon
driver, but in practice it is not easy to guess the right value
because of the way the preallocation code uses image_size. For this
reason, it seems reasonable to allow users to control the amount of
memory reserved for driver allocations made after the hibernate
preallocation, which currently is constant and amounts to 1 MB.

Introduce a new sysfs file, /sys/power/reserved_size, whose value
will be used as the amount of memory to reserve for the
post-preallocation reservations made by device drivers, in bytes.
For backwards compatibility, set its default (and initial) value to
the currently used number (1 MB).

References: https://bugzilla.kernel.org/show_bug.cgi?id=34102
Reported-and-tested-by: Martin Steigerwald <Martin@Lichtvoll.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>

PM: Drop pm_flags that is not necessary

The variable pm_flags is used to prevent APM from being enabled
along with ACPI, which would lead to problems. However, acpi_init()
is always called before apm_init() and after acpi_init() has
returned, it is known whether or not ACPI will be used. Namely, if
acpi_disabled is not set after acpi_init() has returned, this means
that ACPI is enabled. Thus, it is sufficient to check acpi_disabled
in apm_init() to prevent APM from being enabled in parallel with
ACPI.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Len Brown <len.brown@intel.com>

PM / ACPI: Remove references to pm_flags from bus.c

If direct references to pm_flags are removed from drivers/acpi/bus.c,
CONFIG_ACPI will not need to depend on CONFIG_PM any more. Make that
happen.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Len Brown <len.brown@intel.com>

workqueue, freezer: unify spelling of 'freeze' + 'able' to 'freezable'

There are two spellings in use for 'freeze' + 'able' - 'freezable' and
'freezeable'. The former is the more prominent one. The latter is
mostly used by workqueue and in a few other odd places. Unify the
spelling to 'freezable'.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Dmitry Torokhov <dtor@mail.ru>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Steven Whitehouse <swhiteho@redhat.com>

PM: Add sysfs attr for rechecking dev hash from PM trace

If the device which fails to resume is part of a loadable kernel module
it won't be checked at startup against the magic number stored in the
RTC.

Add a read-only sysfs attribute /sys/power/pm_trace_dev_match which
contains a list of newline separated devices (usually just the one)
which currently match the last magic number. This allows the device
which is failing to resume to be found after the modules are loaded
again.

Signed-off-by: James Hogan <james@albanarts.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM / Wakeup: Introduce wakeup source objects and event statistics (v3)

Introduce struct wakeup_source for representing system wakeup sources
within the kernel and for collecting statistics related to them.
Make the recently introduced helper functions pm_wakeup_event(),
pm_stay_awake() and pm_relax() use struct wakeup_source objects
internally, so that wakeup statistics associated with wakeup devices
can be collected and reported in a consistent way (the definition of
pm_relax() is changed, which is harmless, because this function is
not called directly by anyone yet). Introduce new wakeup-related
sysfs device attributes in /sys/devices/.../power for reporting the
device wakeup statistics.

Change the global wakeup events counters event_count and
events_in_progress into atomic variables, so that it is not necessary
to acquire a global spinlock in pm_wakeup_event(), pm_stay_awake()
and pm_relax(), which should allow us to avoid lock contention in
these functions on SMP systems with many wakeup devices.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>

PM / Hibernate: Make default image size depend on total RAM size

The default hibernation image size is currently hard coded and euqal
to 500 MB, which is not a reasonable default on many contemporary
systems. Make it equal 2/5 of the total RAM size (this is slightly
below the maximum, i.e. 1/2 of the total RAM size, and seems to be
generally suitable).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: M. Vefa Bicakci <bicave@superonline.com>

PM / Runtime: Use alloc_workqueue() for creating the PM workqueue

Although we need the PM workqueue to be freezable, we don't need it
to be singlethread. Also, the number of concurrent work items
running on a single CPU need not be constrained. For these reasons
use alloc_workqueue() directly, with suitable arguments, instead of
create_freezeable_workqueue(), to create the runtime PM workqueue.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Tejun Heo <tj@kernel.org>

PM: Make it possible to avoid races between wakeup and system sleep

One of the arguments during the suspend blockers discussion was that
the mainline kernel didn't contain any mechanisms making it possible
to avoid races between wakeup and system suspend.

Generally, there are two problems in that area. First, if a wakeup
event occurs exactly when /sys/power/state is being written to, it
may be delivered to user space right before the freezer kicks in, so
the user space consumer of the event may not be able to process it
before the system is suspended. Second, if a wakeup event occurs
after user space has been frozen, it is not generally guaranteed that
the ongoing transition of the system into a sleep state will be
aborted.

To address these issues introduce a new global sysfs attribute,
/sys/power/wakeup_count, associated with a running counter of wakeup
events and three helper functions, pm_stay_awake(), pm_relax(), and
pm_wakeup_event(), that may be used by kernel subsystems to control
the behavior of this attribute and to request the PM core to abort
system transitions into a sleep state already in progress.

The /sys/power/wakeup_count file may be read from or written to by
user space. Reads will always succeed (unless interrupted by a
signal) and return the current value of the wakeup events counter.
Writes, however, will only succeed if the written number is equal to
the current value of the wakeup events counter. If a write is
successful, it will cause the kernel to save the current value of the
wakeup events counter and to abort the subsequent system transition
into a sleep state if any wakeup events are reported after the write
has returned.

[The assumption is that before writing to /sys/power/state user space
will first read from /sys/power/wakeup_count. Next, user space
consumers of wakeup events will have a chance to acknowledge or
veto the upcoming system transition to a sleep state. Finally, if
the transition is allowed to proceed, /sys/power/wakeup_count will
be written to and if that succeeds, /sys/power/state will be written
to as well. Still, if any wakeup events are reported to the PM core
by kernel subsystems after that point, the transition will be
aborted.]

Additionally, put a wakeup events counter into struct dev_pm_info and
make these per-device wakeup event counters available via sysfs,
so that it's possible to check the activity of various wakeup event
sources within the kernel.

To illustrate how subsystems can use pm_wakeup_event(), make the
low-level PCI runtime PM wakeup-handling code use it.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: markgross <markgross@thegnar.org>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>

PM: Add a switch for disabling/enabling asynchronous suspend/resume

Add sysfs attribute /sys/power/pm_async allowing the user space to
disable/enable asynchronous suspend/resume of devices.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM / Runtime: Export the PM runtime workqueue

This patch (as1306) exports the PM runtime workqueue for use by
loadable modules.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM: Introduce core framework for run-time PM of I/O devices (rev. 17)

Introduce a core framework for run-time power management of I/O
devices. Add device run-time PM fields to 'struct dev_pm_info'
and device run-time PM callbacks to 'struct dev_pm_ops'. Introduce
a run-time PM workqueue and define some device run-time PM helper
functions at the core level. Document all these things.

Special thanks to Alan Stern for his help with the design and
multiple detailed reviews of the pereceding versions of this patch
and to Magnus Damm for testing feedback.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Magnus Damm <damm@igel.co.jp>

PM: Separate suspend to RAM functionality from core

Move the suspend to RAM and standby code from kernel/power/main.c
to two separate files, kernel/power/suspend.c containing the basic
functions and kernel/power/suspend_test.c containing the automatic
suspend test facility based on the RTC clock alarm.

There are no changes in functionality related to these modifications.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>

PM/Suspend: Do not shrink memory before suspend

Remove the shrinking of memory from the suspend-to-RAM code, where
it is not really necessary.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@tuxonice.net>
Acked-by: Wu Fengguang <fengguang.wu@intel.com>

PM core: rename suspend and resume functions

This patch (as1241) renames a bunch of functions in the PM core.
Rather than go through a boring list of name changes, suffice it to
say that in the end we have a bunch of pairs of functions:

device_resume_noirq dpm_resume_noirq
device_resume dpm_resume
device_complete dpm_complete
device_suspend_noirq dpm_suspend_noirq
device_suspend dpm_suspend
device_prepare dpm_prepare

in which device_X does the X operation on a single device and dpm_X
invokes device_X for all devices in the dpm_list.

In addition, the old dpm_power_up and device_resume_noirq have been
combined into a single function (dpm_resume_noirq).

Lastly, dpm_suspend_start and dpm_resume_end are the renamed versions
of the former top-level device_suspend and device_resume routines.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM: Rename device_power_down/up()

Rename the functions performing "_noirq" dev_pm_ops
operations from device_power_down() and device_power_up()
to device_suspend_noirq() and device_resume_noirq().

The new function names are chosen to show that the functions
are responsible for calling the _noirq() versions to finalize
the suspend/resume operation. The current function names do
not perform power down/up anymore so the names may be misleading.

Global function renames:
- device_power_down() -> device_suspend_noirq()
- device_power_up() -> device_resume_noirq()

Static function renames:
- suspend_device_noirq() -> __device_suspend_noirq()
- resume_device_noirq() -> __device_resume_noirq()

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Len Brown <lenb@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

PM: Do not hold dpm_list_mtx while disabling/enabling nonboot CPUs

We shouldn't hold dpm_list_mtx while executing
[disable|enable]_nonboot_cpus(), because theoretically this may lead
to a deadlock as shown by the following example (provided by Johannes
Berg):

CPU 3 CPU 2 CPU 1
suspend/hibernate
something:
rtnl_lock() device_pm_lock()
-> mutex_lock(&dpm_list_mtx)

mutex_lock(&dpm_list_mtx)

linkwatch_work
-> rtnl_lock()
disable_nonboot_cpus()
-> flush CPU 3 workqueue

Fortunately, device drivers are supposed to stop any activities that
might lead to the registration of new device objects way before
disable_nonboot_cpus() is called, so it shouldn't be necessary to
hold dpm_list_mtx over the entire late part of device suspend and
early part of device resume.

Thus, during the late suspend and the early resume of devices acquire
dpm_list_mtx only when dpm_list is going to be traversed and release
it right after that.

This patch is reported to fix the regressions tracked as
http://bugzilla.kernel.org/show_bug.cgi?id=13245.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Miles Lane <miles.lane@gmail.com>
Tested-by: Ming Lei <tom.leiming@gmail.com>

PM/Suspend: Introduce two new platform callbacks to avoid breakage

Commit 900af0d973856d6feb6fc088c2d0d3fde57707d3 (PM: Change suspend
code ordering) changed the ordering of suspend code in such a way
that the platform .prepare() callback is now executed after the
device drivers' late suspend callbacks have run. Unfortunately, this
turns out to break ARM platforms that need to talk via I2C to power
control devices during the .prepare() callback.

For this reason introduce two new platform suspend callbacks,
.prepare_late() and .wake(), that will be called just prior to
disabling non-boot CPUs and right after bringing them back on line,
respectively, and use them instead of .prepare() and .finish() for
ACPI suspend. Make the PM core execute the .prepare() and .finish()
platform suspend callbacks where they were executed previously (that
is, right after calling the regular suspend methods provided by
device drivers and right before executing their regular resume
methods, respectively).

It is not necessary to make analogous changes to the hibernation
code and data structures at the moment, because they are only used
by ACPI platforms.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Reported-by: Russell King <rmk+kernel@arm.linux.org.uk>
Acked-by: Len Brown <len.brown@intel.com>

PM: Change suspend code ordering

Change the ordering of the suspend core code so that the platform
"prepare" callback is executed and the nonboot CPUs are disabled
after calling device drivers' "late suspend" methods.

This change will allow us to rework the PCI PM core so that the power
state of devices is changed in the "late" phase of suspend (and
analogously in the "early" phase of resume), which in turn will allow
us to avoid the race condition where a device using shared interrupts
is put into a low power state with interrupts enabled and then an
interrupt (for another device) comes in and confuses its driver.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Ingo Molnar <mingo@elte.hu>

PM: Rework handling of interrupts during suspend-resume

Use the functions introduced in by the previous patch,
suspend_device_irqs(), resume_device_irqs() and check_wakeup_irqs(),
to rework the handling of interrupts during suspend (hibernation) and
resume. Namely, interrupts will only be disabled on the CPU right
before suspending sysdevs, while device drivers will be prevented
from receiving interrupts, with the help of the new helper function,
before their "late" suspend callbacks run (and analogously during
resume).

In addition, since the device interrups are now disabled before the
CPU has turned all interrupts off and the CPU will ACK the interrupts
setting the IRQ_PENDING bit for them, check in sysdev_suspend() if
any wake-up interrupts are pending and abort suspend if that's the
case.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Ingo Molnar <mingo@elte.hu>

PM: Split up sysdev_[suspend|resume] from device_power_[down|up]

Move the sysdev_suspend/resume from the callee to the callers, with
no real change in semantics, so that we can rework the disabling of
interrupts during suspend/hibernation.

This is based on an earlier patch from Linus.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PM: Fix compilation warning in kernel/power/main.c

Reorder the code in kernel/power/main.c to fix compilation warning
triggered by unsetting CONFIG_SUSPEND.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

pm: struct device - replace bus_id with dev_name(), dev_set_name()

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

tracing: allow tracing of suspend/resume & hibernation code again

Impact: widen function-tracing to suspend+resume (and hibernation) sequences

Now that the ftrace kernel thread is gone, we can allow tracing
during suspend/resume again.

So revert these two commits:

f42ac38c5 "ftrace: disable tracing for suspend to ram"
41108eb10 "ftrace: disable tracing for hibernation"

This should be tested very carefully, as it could interact with
altneratives instruction patching, etc.

Signed-off-by: Ingo Molnar <mingo@elte.hu>

suspend: use WARN not WARN_ON to print the message

By using WARN(), kerneloops.org can collect which component is causing
the delay and make statistics about that. suspend_test_finish() is
currently the number 2 item but unless we can collect who's causing
it we're not going to be able to fix the hot topic ones..

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

pm: rework disabling of user mode helpers during suspend/hibernation

We currently use a PM notifier to disable user mode helpers before suspend
and hibernation and to re-enable them during resume. However, this is not
an ideal solution, because if any drivers want to upload firmware into
memory before suspend, they have to use a PM notifier for this purpose and
there is no guarantee that the ordering of PM notifiers will be as
expected (ie. the notifier that disables user mode helpers has to be run
after the driver's notifier used for uploading the firmware).

For this reason, it seems better to move the disabling and enabling of
user mode helpers to separate functions that will be called by the PM core
as necessary.

[akpm@linux-foundation.org: remove unneeded ifdefs]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

ftrace: disable tracing for suspend to ram

I've been painstakingly debugging the issue with suspend to ram and
ftraced. The 2.6.28 code does not have this issue, but since the mcount
recording is not going to be in 27, this must be solved for the ftrace
daemon version.

The resume from suspend to ram would reboot because it was triple
faulting. Debugging further, I found that calling the mcount function
itself was not an issue, but it would fault when it incremented
preempt_count. preempt_count is on the tasks info structure that is on the
low memory address of the task's stack. For some reason, it could not
write to it. Resuming out of suspend to ram does quite a lot of funny
tricks to get to work, so it is not surprising at all that simply doing a
preempt_disable() would cause a fault.

Thanks to Rafael for suggesting to add a "while (1);" to find the place in
resuming that is causing the fault. I would place the loop somewhere in
the code, compile and reboot and see if it would either reboot (hit the
fault) or simply hang (hit the loop). Doing this over and over again, I
narrowed it down that it was happening in enable_nonboot_cpus.

At this point, I found that it is easier to simply disable tracing around
the suspend code, instead of searching for the particular function that
can not handle doing a preempt_disable.

This patch disables the tracer as it suspends and reenables it on resume.

I tested this patch on my Laptop, and it can resume fine with the patch.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

pm selftest: rtc paranoia

Cope with a quirk of some RTCs (notably ACPI ones) which aren't guaranteed
to implement oneshot behavior when they woke the system from sleeep:
forcibly disable the alarm, just in case.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

pm: boot time suspend selftest

Boot-time test for system suspend states (STR or standby). The generic
RTC framework triggers wakeup alarms, which are used to exit those states.

- Measures some aspects of suspend time ... this uses "jiffies" until
someone converts it to use a timebase that works properly even while
timer IRQs are disabled.

- Triggered by a command line parameter. By default nothing even
vaguely troublesome will happen, but "test_suspend=mem" will give
you a brief STR test during system boot. (Or you may need to use
"test_suspend=standby" instead, if your hardware needs that.)

This isn't without problems. It fires early enough during boot that for
example both PCMCIA and MMC stacks have misbehaved. The workaround in
those cases was to boot without such media cards inserted.

[matthltc@us.ibm.com: fix compile failure in boot time suspend selftest]
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Pavel Machek <pavel@suse.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Suspend-related patches for 2.6.27

ACPI PM: Add possibility to change suspend sequence

There are some systems out there that don't work correctly with
our current suspend/hibernation code ordering. Provide a workaround
for these systems allowing them to pass 'acpi_sleep=old_ordering' in
the kernel command line so that it will use the pre-ACPI 2.0 ("old")
suspend code ordering.

Unfortunately, this requires us to add a platform hook to the
resuming of devices for recovering the platform in case one of the
device drivers' .suspend() routines returns error code. Namely,
ACPI 1.0 specifies that _PTS should be called before suspending
devices, but _WAK still should be called before resuming them in
order to undo the changes made by _PTS. However, if there is an
error during suspending devices, they are automatically resumed
without returning control to the PM core, so the _WAK has to be
called from within device_resume() in that cases.

The patch also reorders and refactors the ACPI suspend/hibernation
code to avoid duplication as far as reasonably possible.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Introduce new top level suspend and hibernation callbacks

Introduce 'struct pm_ops' and 'struct pm_ext_ops' ('ext' meaning
'extended') representing suspend and hibernation operations for bus
types, device classes, device types and device drivers.

Modify the PM core to use 'struct pm_ops' and 'struct pm_ext_ops'
objects, if defined, instead of the ->suspend(), ->resume(),
->suspend_late(), and ->resume_early() callbacks (the old callbacks
will be considered as legacy and gradually phased out).

The main purpose of doing this is to separate suspend (aka S2RAM and
standby) callbacks from hibernation callbacks in such a way that the
new callbacks won't take arguments and the semantics of each of them
will be clearly specified. This has been requested for multiple
times by many people, including Linus himself, and the reason is that
within the current scheme if ->resume() is called, for example, it's
difficult to say why it's been called (ie. is it a resume from RAM or
from hibernation or a suspend/hibernation failure etc.?).

The second purpose is to make the suspend/hibernation callbacks more
flexible so that device drivers can handle more than they can within
the current scheme. For example, some drivers may need to prevent
new children of the device from being registered before their
->suspend() callbacks are executed or they may want to carry out some
operations requiring the availability of some other devices, not
directly bound via the parent-child relationship, in order to prepare
for the execution of ->suspend(), etc.

Ultimately, we'd like to stop using the freezing of tasks for suspend
and therefore the drivers' suspend/hibernation code will have to take
care of the handling of the user space during suspend/hibernation.
That, in turn, would be difficult within the current scheme, without
the new ->prepare() and ->complete() callbacks.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Suspend: Invoke suspend notifications after console switch

In order to fix APM emulation it is necessary to enable apm-emulation
notifications for suspends triggered in various ways via the suspend
notifiers. However, this will cause the systems using APM emulation
to lock up between X being needed to switch away from the VT and X
already waiting for resume in the APM ioctl.

This patch moves the console switch (if enabled) before the suspend
notification (and after the resume notification) to avoid this issue.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

Suspend: Add config option to disable the freezer if architecture wants that

This patch makes the freezer optional for suspend to allow the
system to work (or not work) like the original PMU suspend.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

Suspend: Introduce begin() and end() callbacks

On ACPI systems the target state set by acpi_pm_set_target() is
reset by acpi_pm_finish(), but that need not be called if the
suspend fails.  All platforms that use the .set_target() global
suspend callback are affected by analogous issues.

For this reason, we need an additional global suspend callback that
will reset the target state regardless of whether or not the suspend
is successful.  Also, it is reasonable to rename the .set_target()
callback, since it will be used for a different purpose on ACPI
systems (due to ACPI 1.0x code ordering requirements).

Introduce the global suspend callback .end() to be executed at the
end of the suspend sequence and rename the .set_target() global
suspend callback to .begin().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

suspend: fix ia64 allmodconfig build

kernel/power/main.c:488: error: ‘pm_test_attr’ undeclared here (not in a function)

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

Suspend: Use common prefix in messages

Make suspend messages start with one common prefix "PM: ".

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Len Brown <len.brown@intel.com>

Suspend: Fix comment in main.c

Fix a comment in kernel/power/main.c so that it doesn't contain lines
longer that 80 characters.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Len Brown <len.brown@intel.com>

Suspend: Fix compilation warning for CONFIG_SUSPEND unset

Suspend: Make debug facility depend on CONFIG_SUSPEND

Make the new suspend debug facility code depend on CONFIG_SUSPEND,
as appropriate, to remove the compiler warning printed when CONFIG_PM is set
and CONFIG_SUSPEND is not set.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Len Brown <len.brown@intel.com>

PM: Convert PM notifiers to out-of-line code

This patch (as1008b) converts the PM notifier routines from inline
calls to out-of-line code. It also prevents pm_chain_head from
being created when CONFIG_PM_SLEEP isn't enabled, and EXPORTs the
notifier registration and unregistration routines.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

suspend: build fix responding to 2.6.25 kset change

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>

Suspend: Testing facility (rev. 2)

Introduce sysfs attribute /sys/power/pm_test allowing one to test the suspend
core code.  Namely, writing one of the strings:

freezer
devices
platform
processors
core

to this file causes the suspend code to work in one of the test modes defined as
follows:

freezer
- test the freezing of processes

devices
- test the freezing of processes and suspending of devices

platform
- test the freezing of processes, suspending of devices and platform global
  control methods(*)

processors
- test the freezing of processes, suspending of devices, platform global
  control methods and the disabling of nonboot CPUs

core
- test the freezing of processes, suspending of devices, platform global
  control methods, the disabling of nonboot CPUs and suspending of
  platform/system devices

(*) These are ACPI global control methods on ACPI systems

Then, if a suspend is started by normal means, the suspend core will perform
its normal operations up to the point indicated by given test level.  Next, it
will wait for 5 seconds and carry out the resume operations needed to transition
the system back to the fully functional state.

Writing "none" to /sys/power/pm_test turns the testing off.

When open for reading, /sys/power/pm_test contains a space-separated list of all
available tests (including "none" that represents the normal functionality) in
which the current test level is indicated by square brackets.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Len Brown <len.brown@intel.com>

driver core: make /sys/power a kobject

/sys/power should not be a kset, that's overkill. This patch renames it
to power_kset and fixes up all usages of it in the tree.

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Driver Core: switch all dynamic ksets to kobj_sysfs_ops

Switch all dynamically created ksets, that export simple attributes,
to kobj_attribute from subsys_attribute. Struct subsys_attribute will
be removed.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mike Halcrow <mhalcrow@us.ibm.com>
Cc: Phillip Hellewell <phillip@hellewell.homeip.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

kset: convert /sys/power to use kset_create

Dynamically create the kset instead of declaring it statically. We also
rename power_subsys to power_kset to catch all users of the variable and
we properly export it so that people don't have to guess that it really
is present in the system.

The pseries code is wierd, why is it createing /sys/power if CONFIG_PM
is disabled? Oh well, stupid big boxes ignoring config options...

Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

kobject: remove struct kobj_type from struct kset

We don't need a "default" ktype for a kset. We should set this
explicitly every time for each kset. This change is needed so that we
can make ksets dynamic, and cleans up one of the odd, undocumented
assumption that the kset/kobject/ktype model has.

This patch is based on a lot of help from Kay Sievers.

Nasty bug in the block code was found by Dave Young
<hidave.darkstar@gmail.com>

Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

PM: ACPI and APM must not be enabled at the same time

ACPI and APM used "pm_active" to guarantee that
they would not be simultaneously active.

But pm_active was recently moved under CONFIG_PM_LEGACY,
so that without CONFIG_PM_LEGACY, pm_active became a NOP --
allowing ACPI and APM to both be simultaneously enabled.
This caused unpredictable results, including boot hangs.

Further, the code under CONFIG_PM_LEGACY is scheduled
for removal.

So replace pm_active with pm_flags.
pm_flags depends only on CONFIG_PM,
which is present for both CONFIG_APM and CONFIG_ACPI.

http://bugzilla.kernel.org/show_bug.cgi?id=9194

Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

freezer: do not sync filesystems from freeze_processes

The syncing of filesystems from within the freezer is generally not needed.
Also, if there's an ext3 filesystem loopback-mounted from a FUSE one, the
syncing results in writes to it and deadlocks. Similarly, it will deadlock if
FUSE implements sync.

Change freeze_processes() so that it doesn't execute sys_sync() and make the
suspend and hibernation code path sync filesystems independently of the
freezer.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PM: Make suspend_ops static

The variable suspend_ops representing the set of global platform-specific
suspend-related operations, used by the PM core, need not be exported outside
of kernel/power/main.c .  Make it static.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PM: Rework struct platform_suspend_ops

There is no reason why the .prepare() and .finish() methods in 'struct
platform_suspend_ops' should take any arguments, since architectures don't use
these methods' argument in any practically meaningful way (ie. either the
target system sleep state is conveyed to the platform by .set_target(), or
there is only one suspend state supported and it is indicated to the PM core
by .valid(), or .prepare() and .finish() aren't defined at all).  There also
is no reason why .finish() should return any result.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PM: Rename struct pm_ops and related things

The name of 'struct pm_ops' suggests that it is related to the power
management in general, but in fact it is only related to suspend.  Moreover,
its name should indicate what this structure is used for, so it seems
reasonable to change it to 'struct platform_suspend_ops'.  In that case, the
name of the global variable of this type used by the PM core and the names of
related functions should be changed accordingly.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

make kernel/power/main.c:suspend_enter() static

suspend_enter() can now become static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Introduce CONFIG_SUSPEND for suspend-to-Ram and standby

Introduce CONFIG_SUSPEND representing the ability to enter system sleep
states, such as the ACPI S3 state, and allow the user to choose SUSPEND
and HIBERNATION independently of each other.

Make HOTPLUG_CPU be selected automatically if SUSPEND or HIBERNATION has
been chosen and the kernel is intended for SMP systems.

Also, introduce CONFIG_PM_SLEEP which is automatically selected if
CONFIG_SUSPEND or CONFIG_HIBERNATION is set and use it to select the
code needed for both suspend and hibernation.

The top-level power management headers and the ACPI code related to
suspend and hibernation are modified to use the new definitions (the
changes in drivers/acpi/sleep/main.c are, mostly, moving code to reduce
the number of ifdefs).

There are many other files in which CONFIG_PM can be replaced with
CONFIG_PM_SLEEP or even with CONFIG_SUSPEND, but they can be updated in
the future.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Replace CONFIG_SOFTWARE_SUSPEND with CONFIG_HIBERNATION

Replace CONFIG_SOFTWARE_SUSPEND with CONFIG_HIBERNATION to avoid
confusion (among other things, with CONFIG_SUSPEND introduced in the
next patch).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PM: Integrate beeping flag with existing acpi_sleep flags

Move "debug during resume from s2ram" into the variable we already use
for real-mode flags to simplify code. It also closes nasty trap for
the user in acpi_sleep_setup; order of parameters actually mattered there,
acpi_sleep=s3_bios,s3_mode doing something different from
acpi_sleep=s3_mode,s3_bios.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PM: Optional beeping during resume from suspend to RAM

Add a feature allowing the user to make the system beep during a resume from
suspend to RAM, on x86_64 and i386.

This is useful for the users with broken resume from RAM, so that they can
verify if the control reaches the kernel after a wake-up event.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PM: Reduce code duplication between main.c and user.c

The SNAPSHOT_S2RAM ioctl code is outdated and it should not duplicate the
suspend code in kernel/power/main.c. Fix that.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PM: introduce hibernation and suspend notifiers

Make it possible to register hibernation and suspend notifiers, so that
subsystems can perform hibernation-related or suspend-related operations that
should not be carried out by device drivers' .suspend() and .resume()
routines.

[akpm@linux-foundation.org: build fixes]
[akpm@linux-foundation.org: cleanups]
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PM: introduce set_target method in pm_ops

Commit 52ade9b3b97fd3bea42842a056fe0786c28d0555 changed the suspend code
ordering to execute pm_ops->prepare() after the device model per-device
.suspend() calls in order to fix some ACPI-related issues. Unfortunately, it
broke the at91 platform which assumed that pm_ops->prepare() would be called
before suspending devices.

at91 used pm_ops->prepare() to get notified of the target system sleep state,
so that it could use this information while suspending devices. However, with
the current suspend code ordering pm_ops->prepare() is called too late for
this purpose. Thus, at91 needs an additional method in 'struct pm_ops' that
will be used for notifying the platform of the target system sleep state.
Moreover, in the future such a method will also be needed by ACPI.

This patch adds the .set_target() method to 'struct pm_ops' and makes the
suspend code call it, if implemented, before executing the device model
per-device .suspend() calls. It also modifies the at91 code to use
pm_ops->set_target() instead of pm_ops->prepare().

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Len Brown <lenb@kernel.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

swsusp: fix sysfs interface

The sysfs files /sys/power/disk and /sys/power/state do not work as
documented, since they allow the user to write only a few initial
characters of the input string to trigger the option (eg. 'echo pl >
/sys/power/disk' activates the platform mode of hibernation). Fix it.

Special thanks to Peter Moulder <Peter.Moulder@infotech.monash.edu.au> for
pointing out the problem.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Fix ACPI suspend / device suspend ordering problem

In commit e3c7db621bed4afb8e231cb005057f2feb5db557 we fixed the resume
ordering, so that the ACPI low-level resume code was called before the
actual driver resume was called. However, that broke the nesting logic
of suspend and resume, and we continued to suspend the devices _after_
we the ACPI device suspend code was called.

That resulted in us saving PCI state for devices that had already been
changed by ACPI, and in some cases disabled entirely (causing the PCI
save_state to be all-ones). Which in turn caused the wrong state to be
written back on resume.

This moves the ACPI device suspend to after the device model per-device
suspend() calls. This fixes the bogus state save.

Thanks to Lukáš Hejtmánek for testing.

Acked-by: Lukas Hejtmanek <xhejtman@ics.muni.cz>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Len Brown <len.brown@intel.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

PM: Separate hibernation code from suspend code

[ With Johannes Berg <johannes@sipsolutions.net> ]

Separate the hibernation (aka suspend to disk code) from the other suspend
code. In particular:

* Remove the definitions related to hibernation from include/linux/pm.h
* Introduce struct hibernation_ops and a new hibernate() function to hibernate
the system, defined in include/linux/suspend.h
* Separate suspend code in kernel/power/main.c from hibernation-related code
in kernel/power/disk.c and kernel/power/user.c (with the help of
hibernation_ops)
* Switch ACPI (the only user of pm_ops.pm_disk_mode) to hibernation_ops

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

remove software_suspend()

Remove software_suspend() and all its users since
pm_suspend(PM_SUSPEND_DISK) should be equivalent and there's no point in
having two interfaces for the same thing.

The patch also changes the valid_state function to return 0 (false) for
PM_SUSPEND_DISK when SOFTWARE_SUSPEND is not configured instead of
accepting it and having the whole thing fail later.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

swsusp: do not use page flags

Make swsusp use memory bitmaps instead of page flags for marking 'nosave' and
free pages. This allows us to 'recycle' two page flags that can be used for
other purposes. Also, the memory needed to store the bitmaps is allocated
when necessary (ie. before the suspend) and freed after the resume which is
more reasonable.

The patch is designed to minimize the amount of changes and there are some
nice simplifications and optimizations possible on top of it. I am going to
implement them separately in the future.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

remove "struct subsystem" as it is no longer needed

We need to work on cleaning up the relationship between kobjects, ksets and
ktypes. The removal of 'struct subsystem' is the first step of this,
especially as it is not really needed at all.

Thanks to Kay for fixing the bugs in this patch.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

power management: force pm_ops.valid callback to be assigned

This patch changes the docs and behaviour from "all states valid" to "no
states valid" if no .valid callback is assigned. Users of pm_ops that only
need mem sleep can assign pm_valid_only_mem without any overhead, others
will require more elaborate callbacks.

Now that all users of pm_ops have a .valid callback this is a safe thing to
do and prevents things from getting messy again as they were before.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Looks-okay-to: Rafael J. Wysocki <rjw@sisk.pl>
Cc: <linux-pm@lists.linux-foundation.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

power management: implement pm_ops.valid for everybody

Almost all users of pm_ops only support mem sleep, don't check in .valid and
don't reject any others in .prepare so users can be confused if they check
/sys/power/state, especially when new states are added (these would then
result in s-t-r although they're supposed to be something different).

This patch implements a generic pm_valid_only_mem function that is then
exported for users and puts it to use in almost all existing pm_ops.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: David Brownell <david-b@pacbell.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: linux-pm@lists.linux-foundation.org
Cc: Len Brown <lenb@kernel.org>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Cc: Greg KH <greg@kroah.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

rework pm_ops pm_disk_mode, kill misuse

This patch series cleans up some misconceptions about pm_ops. Some users of
the pm_ops structure attempt to use it to stop the user from entering suspend
to disk, this, however, is not possible since the user can always use
"shutdown" in /sys/power/disk and then the pm_ops are never invoked. Also,
platforms that don't support suspend to disk simply should not allow
configuring SOFTWARE_SUSPEND (read the help text on it, it only selects
suspend to disk and nothing else, all the other stuff depends on PM).

The pm_ops structure is actually intended to provide a way to enter
platform-defined sleep states (currently supported states are "standby" and
"mem" (suspend to ram)) and additionally (if SOFTWARE_SUSPEND is configured)
allows a platform to support a platform specific way to enter low-power mode
once everything has been saved to disk. This is currently only used by ACPI
(S4).

This patch:

The pm_ops.pm_disk_mode is used in totally bogus ways since nobody really
seems to understand what it actually does.

This patch clarifies the pm_disk_mode description.

It also removes all the arm and sh users that think they can veto suspend to
disk via pm_ops; not so since the user can always do echo shutdown >
/sys/power/disk, they need to find a better way involving Kconfig or such.

ACPI is the only user left with a non-zero pm_disk_mode.

The patch also sets the default mode to shutdown again, but when a new pm_ops
is registered its pm_disk_mode is selected as default, that way the default
stays for ACPI where it is apparently required.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: David Brownell <david-b@pacbell.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: <linux-pm@lists.linux-foundation.org>
Cc: Len Brown <lenb@kernel.org>
Acked-by: Russell King <rmk@arm.linux.org.uk>
Cc: Greg KH <greg@kroah.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

s2ram: add arch irq disable/enable hooks

After some more discussion this patch replaces it:

From: Johannes Berg <johannes@sipsolutions.net>
Subject: suspend: add arch irq disable/enable hooks

For powermac, we need to do some things between suspending devices and
device_power_off, for example setting the decrementer. This patch
allows architectures to define arch_s2ram_{en,dis}able_irqs in their
asm/suspend.h to have control over this step.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

power management: no valid states w/o pm_ops

Change /sys/power/state to not advertise any valid states (except for disk
if SOFTWARE_SUSPEND is enabled) when no pm_ops have been set so userspace
can easily discover what states should be available.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: "Randy.Dunlap" <rdunlap@xenotime.net>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Macheck <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] PM: Change code ordering in main.c

As indicated in a recent thread on Linux-PM, it's necessary to call
pm_ops->finish() before devce_resume(), but enable_nonboot_cpus() has to be
called before pm_ops->finish() (cf.
http://lists.osdl.org/pipermail/linux-pm/2006-November/004164.html). For
consistency, it seems reasonable to call disable_nonboot_cpus() after
device_suspend().

This way the suspend code will remain symmetrical with respect to the resume
code and it may allow us to speed up things in the future by suspending and
resuming devices and/or saving the suspend image in many threads.

The following series of patches reorders the suspend and resume code so that
nonboot CPUs are disabled after devices have been suspended and enabled before
the devices are resumed. It also causes pm_ops->finish() to be called after
enable_nonboot_cpus() wherever necessary.

This patch:

Change the ordering of code in kernel/power/main.c so that device_suspend()
is called before disable_nonboot_cpus() and pm_ops->finish() is called after
enable_nonboot_cpus() and before device_resume(), as indicated by recent
discussion on Linux-PM
(cf. http://lists.osdl.org/pipermail/linux-pm/2006-November/004164.html).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: Greg KH <greg@kroah.com>
Cc: Nigel Cunningham <nigel@suspend2.net>
Cc: Patrick Mochel <mochel@digitalimplant.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PATCH] Drop free_pages()

nr_free_pages is now a simple access to a global variable. Make it a macro
instead of a function.

The nr_free_pages now requires vmstat.h to be included. There is one
occurrence in power management where we need to add the include. Directly
refrer to global_page_state() there to clarify why the #include was added.

[akpm@osdl.org: arm build fix]
[akpm@osdl.org: sparc64 build fix]
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

[PATCH] Export pm_suspend for the shared APM emulation

The new shared APM emulation just like its ARM and MIPS predecessors uses
pm_suspend() which was only exported on SH. Move export to close to it's
definition where it really should be anyway.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] convert pm_sem to a mutex

The power management semaphore is only used as mutex, so convert it.

[akpm@osdl.org: fix rotten bug]
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Pavel Machek <pavel@ucw.cz>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] Add include/linux/freezer.h and move definitions from sched.h

Move process freezing functions from include/linux/sched.h to freezer.h, so
that modifications to the freezer or the kernel configuration don't require
recompiling just about everything.

[akpm@osdl.org: fix ueagle driver]
Signed-off-by: Nigel Cunningham <nigel@suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

ACPI: S4: Use "platform" rather than "shutdown" mode by default

It has been reported that on some systems the functionality after a resume
from disk is limited if the system is simply powered off during the suspend
instead of using the ACPI S4 suspend (aka platform mode).

Unfortunately the default is currently to power off the system during the
suspend so the users of these systems experience problems after the resume
if they don't switch to the platform mode explicitly. This patch makes swsusp
use the platform mode by default to avoid such situations.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Stefan Seyfried <seife@suse.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Len Brown <len.brown@intel.com>

[PATCH] PM: Add pm_trace switch

Add the pm_trace attribute in /sys/power which has to be explicitly set to
one to really enable the "PM tracing" code compiled in when CONFIG_PM_TRACE
is set (which modifies the machine's CMOS clock in unpredictable ways).

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] Disable CPU hotplug during suspend

The current suspend code has to be run on one CPU, so we use the CPU
hotplug to take the non-boot CPUs offline on SMP machines. However, we
should also make sure that these CPUs will not be enabled by someone else
after we have disabled them.

The functions disable_nonboot_cpus() and enable_nonboot_cpus() are moved to
kernel/cpu.c, because they now refer to some stuff in there that should
better be static. Also it's better if disable_nonboot_cpus() returns an
error instead of panicking if something goes wrong, and
enable_nonboot_cpus() has no reason to panic(), because the CPUs may have
been enabled by the userland before it tries to take them online.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

PM: no suspend_prepare() phase

Remove the new suspend_prepare() phase. It doesn't seem very usable,
has never been tested, doesn't address fault cleanup, and would need
a sibling resume_complete(); plus there are no real use cases. It
could be restored later if those issues get resolved.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Suspend infrastructure cleanup and extension

Allow devices to participate in the suspend process more intimately,
in particular, allow the final phase (with interrupts disabled) to
also be open to normal devices, not just system devices.

Also, allow classes to participate in device suspend.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

[PATCH] constify parts of kernel/power/

Signed-off-by: Andreas Mohr <andi@lisas.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] suspend_console() warning fix

kernel/power/main.c: In function 'suspend_prepare':
kernel/power/main.c:89: warning: implicit declaration of function 'suspend_console'
kernel/power/main.c: In function 'suspend_finish':
kernel/power/main.c:137: warning: implicit declaration of function 'resume_console'

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

Add support for suspending and resuming the whole console subsystem

Trying to suspend/resume with console messages flying all around is
doomed to failure, when the devices that the messages are trying to
go to are being shut down.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] off-by-1 in kernel/power/main.c

There's an off-by-1 in kernel/power/main.c:state_store() ... if your
kernel just happens to have some non-zero data at pm_states[PM_SUSPEND_MAX]
(i.e. one past the end of the array) then it'll let you write anything you
want to /sys/power/state and in response the box will enter S5.

Signed-off-by: dean gaudet <dean@arctic.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] swsusp: add s2ram ioctl to userland interface

Add the SNAPSHOT_S2RAM ioctl to the snapshot device.

This ioctl allows a userland application to make the system (previously frozen
with the SNAPSHOT_FREE ioctl) enter the S3 state without freezing processes
and disabling nonboot CPUs for the second time.

This will allow us to implement the suspend-to-disk-and-RAM (STDR)
functionality in the userland suspend tools.

Signed-off-by: Luca Tettamanti <kronos.it@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[ACPI] SMP S3 resume: evaluate _WAK after INIT

On SMP resume from S3, we reset (INIT) the non-boot
processors to boot them cleanly. But the BIOS needs
to execute _WAK after INIT in order to properly
initialized these processors upon resume.

http://bugzilla.kernel.org/show_bug.cgi?id=5651

Signed-off-by: David Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

[PATCH] fix swsusp on machines not supporting S4

Fix swsusp on machines not supporting S4. With recent changes, it is not
possible to trigger it using /sys filesystem. Swsusp does not really need
any support from low-level code, it is possible to reboot or halt at the
end of suspend.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Cc: "Brown, Len" <len.brown@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] sleep: Fix oops in enter_state

If ACPI sleep is not configured, but someone still wants to run swsusp,
he'd get oops in enter_state. This is regression since 2.6.14 and this
fixes it.

Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] introduce .valid callback for pm_ops

Add pm_ops.valid callback, so only the available pm states show in
/sys/power/state. And this also makes an earlier states error report at
enter_state before we do actual suspend/resume.

Signed-off-by: Shaohua Li<shaohua.li@intel.com>
Acked-by: Pavel Machek<pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] pm: clean up /sys/power/disk

Clean code up a bit, and only show suspend to disk as available when
it is configured in.

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[ACPI] Suspend to RAM fix

Free some RAM before entering S3 so that upon
resume we can be sure early allocations will succeed.

http://bugzilla.kernel.org/show_bug.cgi?id=3469

Signed-off-by: David Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

[ACPI] ACPI poweroff fix

Register an "acpi" system device to be notified of shutdown preparation.
This depends on CONFIG_PM

http://bugzilla.kernel.org/show_bug.cgi?id=4041

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>

[PATCH] suspend/resume SMP support

Using CPU hotplug to support suspend/resume SMP. Both S3 and S4 use
disable/enable_nonboot_cpus API. The S4 part is based on Pavel's original S4
SMP patch.

Signed-off-by: Li Shaohua<shaohua.li@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] Driver Core: pm diagnostics update, check for errors

This patch includes various tweaks in the messaging that appears during
system pm state transitions:

* Warn about certain illegal calls in the device tree, like resuming
child before parent or suspending parent before child. This could
happen easily enough through sysfs, or in some cases when drivers
use device_pm_set_parent().

* Be more consistent about dev_dbg() tracing ... do it for resume() and
shutdown() too, and never if the driver doesn't have that method.

* Say which type of system sleep state is being entered.

Except for the warnings, these only affect debug messaging.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

Linux-2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!