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>
Nothing is using its return value so change it to return void.
No functionality change.
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
There are quite a few cases in which device drivers, bus types or
even the PM core itself may benefit from knowing whether or not
the platform firmware will be involved in the upcoming system power
transition (during system suspend) or whether or not it was involved
in it (during system resume).
For this reason, introduce global system suspend flags that can be
used by the platform code to expose that information for the benefit
of the other parts of the kernel and make the ACPI core set them
as appropriate.
Users of the new flags will be added later.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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>
In preparation for adding support for quiescing timers in the final
stage of suspend-to-idle transitions, rework the freeze_enter()
function making the system wait on a wakeup event, the freeze_wake()
function terminating the suspend-to-idle loop and the mechanism by
which deep idle states are entered during suspend-to-idle.
First of all, introduce a simple state machine for suspend-to-idle
and make the code in question use it.
Second, prevent freeze_enter() from losing wakeup events due to race
conditions and ensure that the number of online CPUs won't change
while it is being executed. In addition to that, make it force
all of the CPUs re-enter the idle loop in case they are in idle
states already (so they can enter deeper idle states if possible).
Next, drop cpuidle_use_deepest_state() and replace use_deepest_state
checks in cpuidle_select() and cpuidle_reflect() with a single
suspend-to-idle state check in cpuidle_idle_call().
Finally, introduce cpuidle_enter_freeze() that will simply find the
deepest idle state available to the given CPU and enter it using
cpuidle_enter().
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
The ACPI GPE wakeup from suspend-to-idle is currently based on using
the IRQF_NO_SUSPEND flag for the ACPI SCI, but that is problematic
for a couple of reasons. First, in principle the ACPI SCI may be
shared and IRQF_NO_SUSPEND does not really work well with shared
interrupts. Second, it may require the ACPI subsystem to special-case
the handling of device notifications depending on whether or not
they are received during suspend-to-idle in some places which would
lead to fragile code. Finally, it's better the handle ACPI wakeup
interrupts consistently with wakeup interrupts from other sources.
For this reason, remove the IRQF_NO_SUSPEND flag from the ACPI SCI
and use enable_irq_wake()/disable_irq_wake() with it instead, which
requires two additional platform hooks to be added to struct
platform_freeze_ops.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
It sometimes may be necessary to abort a system suspend in
progress or wake up the system from suspend-to-idle even if the
pm_wakeup_event()/pm_stay_awake() mechanism is not enabled.
For this purpose, introduce a new global variable pm_abort_suspend
and make pm_wakeup_pending() check its value. Also add routines
for manipulating that variable.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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>
Pull ARM updates from Russell King:
- Major clean-up of the L2 cache support code. The existing mess was
becoming rather unmaintainable through all the additions that others
have done over time. This turns it into a much nicer structure, and
implements a few performance improvements as well.
- Clean up some of the CP15 control register tweaks for alignment
support, moving some code and data into alignment.c
- DMA properties for ARM, from Santosh and reviewed by DT people. This
adds DT properties to specify bus translations we can't discover
automatically, and to indicate whether devices are coherent.
- Hibernation support for ARM
- Make ftrace work with read-only text in modules
- add suspend support for PJ4B CPUs
- rework interrupt masking for undefined instruction handling, which
allows us to enable interrupts earlier in the handling of these
exceptions.
- support for big endian page tables
- fix stacktrace support to exclude stacktrace functions from the
trace, and add save_stack_trace_regs() implementation so that kprobes
can record stack traces.
- Add support for the Cortex-A17 CPU.
- Remove last vestiges of ARM710 support.
- Removal of ARM "meminfo" structure, finally converting us solely to
memblock to handle the early memory initialisation.
* 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (142 commits)
ARM: ensure C page table setup code follows assembly code (part II)
ARM: ensure C page table setup code follows assembly code
ARM: consolidate last remaining open-coded alignment trap enable
ARM: remove global cr_no_alignment
ARM: remove CPU_CP15 conditional from alignment.c
ARM: remove unused adjust_cr() function
ARM: move "noalign" command line option to alignment.c
ARM: provide common method to clear bits in CPU control register
ARM: 8025/1: Get rid of meminfo
ARM: 8060/1: mm: allow sub-architectures to override PCI I/O memory type
ARM: 8066/1: correction for ARM patch 8031/2
ARM: 8049/1: ftrace/add save_stack_trace_regs() implementation
ARM: 8065/1: remove last use of CONFIG_CPU_ARM710
ARM: 8062/1: Modify ldrt fixup handler to re-execute the userspace instruction
ARM: 8047/1: rwsem: use asm-generic rwsem implementation
ARM: l2c: trial at enabling some Cortex-A9 optimisations
ARM: l2c: add warnings for stuff modifying aux_ctrl register values
ARM: l2c: print a warning with L2C-310 caches if the cache size is modified
ARM: l2c: remove old .set_debug method
ARM: l2c: kill L2X0_AUX_CTRL_MASK before anyone else makes use of this
...
The "freeze" sleep state suffers from the same issue that was
addressed by commit ad07277e82 (ACPI / PM: Hold acpi_scan_lock over
system PM transitions) for ACPI sleep states, that is, things break
if ->remove() is called for devices whose system resume callbacks
haven't been executed yet.
It also can be addressed in the same way, by holding the ACPI scan
lock over the "freeze" sleep state and PM transitions to and from
that state, but ->begin() and ->end() platform operations for the
"freeze" sleep state are needed for this purpose.
This change has been tested on Acer Aspire S5 with Thunderbolt.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Enable hibernation for ARM architectures and provide ARM
architecture specific calls used during hibernation.
The swsusp hibernation framework depends on the
platform first having functional suspend/resume.
Then, in order to enable hibernation on a given platform, a
platform_hibernation_ops structure may need to be registered with
the system in order to save/restore any SoC-specific / cpu specific
state needing (re)init over a suspend-to-disk/resume-from-disk cycle.
For example:
- "secure" SoCs that have different sets of control registers
and/or different CR reg access patterns.
- SoCs with L2 caches as the activation sequence there is
SoC-dependent; a full off-on cycle for L2 is not done
by the hibernation support code.
- SoCs requiring steps on wakeup _before_ the "generic" parts
done by cpu_suspend / cpu_resume can work correctly.
- SoCs having persistent state which is maintained during suspend
and resume, but will be lost during the power off cycle after
suspend-to-disk.
This is a rebase/rework of Frank Hofmann's v5 hibernation patchset.
Acked-by: Russ Dill <Russ.Dill@ti.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Signed-off-by: Sebastian Capella <sebastian.capella@linaro.org>
Acked-by: Pavel Machek <pavel@ucw.cz>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
[fixed duplicate virt_to_pfn() definition --rmk]
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
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>
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>
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>
Android uses one wakelock statistics that is only necessary for
opportunistic sleep. Namely, the prevent_suspend_time field
accumulates the total time the given wakelock has been locked
while "automatic suspend" was enabled. Add an analogous field,
prevent_sleep_time, to wakeup sources and make it behave in a similar
way.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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>
Since suspend_stats_update() is only called from pm_suspend(),
move its code directly into that function and remove the static
inline definition from include/linux/suspend.h. Clean_up
pm_suspend() in the process.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
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>
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>
Commit 33e638b, "PM / Sleep: Use the freezer_count() functions in
[un]lock_system_sleep() APIs" introduced an undesirable change in the
behaviour of unlock_system_sleep() since freezer_count() internally calls
try_to_freeze() - which we don't need in unlock_system_sleep().
And commit bcda53f, "PM / Sleep: Replace mutex_[un]lock(&pm_mutex) with
[un]lock_system_sleep()" made these APIs wide-spread. This caused a
regression in suspend-to-disk where snapshot_read() and snapshot_write()
were getting frozen due to the try_to_freeze embedded in
unlock_system_sleep(), since these functions were invoked when the freezing
condition was still in effect.
Fix this by rewriting unlock_system_sleep() by open-coding freezer_count()
and dropping the try_to_freeze() part. Not only will this fix the
regression but this will also ensure that the API only does what it is
intended to do, and nothing more, under the hood.
While at it, make the code more correct and robust by ensuring that the
PF_FREEZER_SKIP flag gets cleared with pm_mutex held, to avoid a race with
the freezer.
Also, to be on the safer side, open-code freezer_do_not_count() as well
(inside lock_system_sleep()), to ensure that any unrelated modification to
freezer[_do_not]_count() does not break things again!
Reported-and-tested-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The [un]lock_system_sleep() APIs were originally introduced to mutually
exclude memory hotplug and hibernation.
Directly using mutex_lock(&pm_mutex) to achieve mutual exclusion with
suspend or hibernation code can lead to freezing failures. However, the
APIs [un]lock_system_sleep() can be safely used to achieve the same,
without causing freezing failures.
So, since it would be beneficial to modify all the existing users of
mutex_lock(&pm_mutex) (in all parts of the kernel), so that they use these
safe APIs intead, make these APIs generic by removing the restriction that
they work only when CONFIG_HIBERNATE_CALLBACKS is set. Moreover, that
restriction didn't buy us anything anyway.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Now that freezer_count() and freezer_do_not_count() don't have the restriction
that they are effective only when called by userspace processes, use
them in lock_system_sleep() and unlock_system_sleep() instead of open-coding
their parts.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
The lock_system_sleep() function is used in the memory hotplug code at
several places in order to implement mutual exclusion with hibernation.
However, this function tries to acquire the 'pm_mutex' lock using
mutex_lock() and hence blocks in TASK_UNINTERRUPTIBLE state if it doesn't
get the lock. This would lead to task freezing failures and hence
hibernation failure as a consequence, even though the hibernation call path
successfully acquired the lock.
But it is to be noted that, since this task tries to acquire pm_mutex, if it
blocks due to this, we are *100% sure* that this task is not going to run
as long as hibernation sequence is in progress, since hibernation releases
'pm_mutex' only at the very end, when everything is done.
And this means, this task is going to be anyway blocked for much more longer
than what the freezer intends to achieve; which means, freezing and thawing
doesn't really make any difference to this task!
So, to fix freezing failures, we just ask the freezer to skip freezing this
task, since it is already "frozen enough".
But instead of calling freezer_do_not_count() and freezer_count() as it is,
we use only the relevant parts of those functions, because restrictions
such as 'the task should be a userspace one' etc., might not be relevant in
this scenario.
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Introduce the config option CONFIG_VT_CONSOLE_SLEEP in order to cleanup
the #if defined ugliness for the vt suspend support functions. Note that
CONFIG_VT_CONSOLE is already dependant on CONFIG_VT.
The function pm_set_vt_switch is actually dependant on CONFIG_VT and not
CONFIG_PM_SLEEP. This fixes a compile error when CONFIG_PM_SLEEP is
not set:
drivers/tty/vt/vt_ioctl.c:1794: error: redefinition of 'pm_set_vt_switch'
include/linux/suspend.h:17: error: previous definition of 'pm_set_vt_switch' was here
Also, remove the incorrect path from the comment in console.c.
[rjw: Replaced #if defined() with #ifdef in suspend.h.]
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
For s390 there is one additional byte associated with each page,
the storage key. This byte contains the referenced and changed
bits and needs to be included into the hibernation image.
If the storage keys are not restored to their previous state all
original pages would appear to be dirty. This can cause
inconsistencies e.g. with read-only filesystems.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
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>
It is not necessary to share the same notifier.h.
Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: David Miller <davem@davemloft.net>
Acked-by: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A system or a device may need to control suspend/wakeup events. It may
want to wakeup the system after a predefined amount of time or at a
predefined event decided while entering suspend for polling or delayed
work. Then, it may want to enter suspend again if its predefined wakeup
condition is the only wakeup reason and there is no outstanding events;
thus, it does not wakeup the userspace unnecessary or unnecessary
devices and keeps suspended as long as possible (saving the power).
Enabling a system to wakeup after a specified time can be easily
achieved by using RTC. However, to enter suspend again immediately
without invoking userland and unrelated devices, we need additional
features in the suspend framework.
Such need comes from:
1. Monitoring a critical device status without interrupts that can
wakeup the system. (in-suspend polling)
An example is ambient temperature monitoring that needs to shut down
the system or a specific device function if it is too hot or cold. The
temperature of a specific device may be needed to be monitored as well;
e.g., a charger monitors battery temperature in order to stop charging
if overheated.
2. Execute critical "delayed work" at suspend.
A driver or a system/board may have a delayed work (or any similar
things) that it wants to execute at the requested time.
For example, some chargers want to check the battery voltage some
time (e.g., 30 seconds) after the battery is fully charged and the
charger has stopped. Then, the charger restarts charging if the voltage
has dropped more than a threshold, which is smaller than "restart-charger"
voltage, which is a threshold to restart charging regardless of the
time passed.
This patch allows to add "suspend_again" callback at struct
platform_suspend_ops and let the "suspend_again" callback return true if
the system is required to enter suspend again after the current instance
of wakeup. Device-wise suspend_again implemented at dev_pm_ops or
syscore is not done because: a) suspend_again feature is usually under
platform-wise decision and controls the behavior of the whole platform
and b) There are very limited devices related to the usage cases of
suspend_again; chargers and temperature sensors are mentioned so far.
With suspend_again callback registered at struct platform_suspend_ops
suspend_ops in kernel/power/suspend.c with suspend_set_ops by the
platform, the suspend framework tries to enter suspend again by
looping suspend_enter() if suspend_again has returned true and there has
been no errors in the suspending sequence or pending wakeups (by
pm_wakeup_pending).
Tested at Exynos4-NURI.
[rjw: Fixed up kerneldoc comment for suspend_enter().]
Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Xen save/restore is going to use hibernate device callbacks for
quiescing devices and putting them back to normal operations and it
would need to select CONFIG_HIBERNATION for this purpose. However,
that also would cause the hibernate interfaces for user space to be
enabled, which might confuse user space, because the Xen kernels
don't support hibernation. Moreover, it would be wasteful, as it
would make the Xen kernels include a substantial amount of code that
they would never use.
To address this issue introduce new power management Kconfig option
CONFIG_HIBERNATE_CALLBACKS, such that it will only select the code
that is necessary for the hibernate device callbacks to work and make
CONFIG_HIBERNATION select it. Then, Xen save/restore will be able to
select CONFIG_HIBERNATE_CALLBACKS without dragging the entire
hibernate code along with it.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Shriram Rajagopalan <rshriram@cs.ubc.ca>
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (59 commits)
ACPI / PM: Fix build problems for !CONFIG_ACPI related to NVS rework
ACPI: fix resource check message
ACPI / Battery: Update information on info notification and resume
ACPI: Drop device flag wake_capable
ACPI: Always check if _PRW is present before trying to evaluate it
ACPI / PM: Check status of power resources under mutexes
ACPI / PM: Rename acpi_power_off_device()
ACPI / PM: Drop acpi_power_nocheck
ACPI / PM: Drop acpi_bus_get_power()
Platform / x86: Make fujitsu_laptop use acpi_bus_update_power()
ACPI / Fan: Rework the handling of power resources
ACPI / PM: Register power resource devices as soon as they are needed
ACPI / PM: Register acpi_power_driver early
ACPI / PM: Add function for updating device power state consistently
ACPI / PM: Add function for device power state initialization
ACPI / PM: Introduce __acpi_bus_get_power()
ACPI / PM: Introduce function for refcounting device power resources
ACPI / PM: Add functions for manipulating lists of power resources
ACPI / PM: Prevent acpi_power_get_inferred_state() from making changes
ACPICA: Update version to 20101209
...
The saving of the ACPI NVS area during hibernation and suspend and
restoring it during the subsequent resume is entirely specific to
ACPI, so move it to drivers/acpi and drop the CONFIG_SUSPEND_NVS
configuration option which is redundant.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
When ioremap() fails (which might happen for some reason), we nicely
oops in suspend_nvs_save() due to NULL dereference by memcpy() in there.
Fail gracefully instead.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Len Brown <len.brown@intel.com>
To avoid confusion with the meaning and return value of
pm_check_wakeup_events() replace it with pm_wakeup_pending() that
will work the other way around (ie. return true when system-wide
power transition should be aborted).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
While at it, fix two checkpatch errors.
Several non-const struct instances constified by this patch were added after
the introduction of platform_suspend_ops in checkpatch.pl's list of "should
be const" structs (79404849e9).
Patch against mainline.
Inspired by hunks of the grsecurity patch, updated for newer kernels.
Signed-off-by: Lionel Debroux <lionel_debroux@yahoo.fr>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Patch against mainline.
Changes since v1: added one hunk; no longer adding "const" qualifier to
pointers in platform_hibernation_ops after seeing
b4144e4f6e.
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
If there is a wakeup event during the freezing of tasks, suspend or
hibernation will fail anyway. Since try_to_freeze_tasks() can take
up to 20 seconds to complete or fail, aborting it as soon as a wakeup
event is detected improves the worst case wakeup latency.
Based on a patch from Arve Hjønnevåg.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
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>
The ACPI suspend code calls suspend_nvs_free() at a wrong place,
which may lead to a memory leak if there's an error executing
acpi_pm_prepare(), because acpi_pm_finish() will not be called in
that case. However, the root cause of this problem is the
apparently confusing ordering of calls in suspend error paths that
needs to be fixed.
In addition to that, fix a typo in a label name in suspend.c.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Len Brown <len.brown@intel.com>
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>
Saving platform non-volatile state may be required for suspend to RAM as
well as hibernation. Move it to more generic code.
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Tested-by: Maxim Levitsky <maximlevitsky@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
Allow memory hotplug and hibernation in the same kernel
Memory hotplug and hibernation were exclusive in Kconfig. This is
obviously a problem for distribution kernels who want to support both in
the same image.
After some discussions with Rafael and others the only problem is with
parallel memory hotadd or removal while a hibernation operation is in
process. It was also working for s390 before.
This patch removes the Kconfig level exclusion, and simply makes the
memory add / remove functions grab the pm_mutex to exclude against
hibernation.
Fixes a regression - old kernels didn't exclude memory hotadd and
hibernation.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Yasunori Goto <y-goto@jp.fujitsu.com>
Acked-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>
The *_nvs_* routines in swsusp.c make use of the io*map()
functions, which are only provided for HAS_IOMEM, thus
breaking compilation if HAS_IOMEM is not set. Fix this
by moving the *_nvs_* routines into hibernate_nvs.c, which
is only compiled if HAS_IOMEM is set.
[rjw: Change the name of the new file to hibernate_nvs.c, add the
license line to the header comment.]
Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Commit 900af0d973 (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>
Make the following header file changes:
- remove arch ifdefs and asm/suspend.h from linux/suspend.h
- add asm/suspend.h to disk.c (for arch_prepare_suspend())
- add linux/io.h to swsusp.c (for ioremap())
- x86 32/64 bit compile fixes
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Cc: Paul Mundt <lethal@linux-sh.org>
Acked-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>
Introduce boolean function system_entering_hibernation() returning
'true' during the last phase of hibernation, in which devices are
being put into low power states and the sleep state (for example,
ACPI S4) is finally entered.
Some device drivers need such a function to check if the system is
in the final phase of hibernation. In particular, some SATA drivers
are going to use it for blacklisting systems in which the disks
should not be spun down during the last phase of hibernation (the
BIOS will do that anyway).
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
According to the ACPI Specification 3.0b, Section 15.3.2,
"OSPM will call the _PTS control method some time before entering a
sleeping state, to allow the platform's AML code to update this
memory image before entering the sleeping state. After the system
awakes from an S4 state, OSPM will restore this memory area and call
the _WAK control method to enable the BIOS to reclaim its memory
image." For this reason, implement a mechanism allowing us to save
the NVS memory during hibernation and to restore it during the
subsequent resume.
Based on a patch by Zhang Rui.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Nigel Cunningham <nigel@tuxonice.net>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>
WARNING: vmlinux.o(.text+0xe684): Section mismatch in reference from the function register_nosave_region() to the function .init.text:__register_nosave_region()
The function register_nosave_region() references
the function __init __register_nosave_region().
This is often because register_nosave_region lacks a __init
annotation or the annotation of __register_nosave_region is wrong.
register_nosave_region calls __init function and is called only from
__init functions
Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Pavel Machek <pavel@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch implements devices state save/restore before after kexec.
This patch together with features in kexec_jump patch can be used for
following:
- A simple hibernation implementation without ACPI support. You can kexec a
hibernating kernel, save the memory image of original system and shutdown
the system. When resuming, you restore the memory image of original system
via ordinary kexec load then jump back.
- Kernel/system debug through making system snapshot. You can make system
snapshot, jump back, do some thing and make another system snapshot.
- Cooperative multi-kernel/system. With kexec jump, you can switch between
several kernels/systems quickly without boot process except the first time.
This appears like swap a whole kernel/system out/in.
- A general method to call program in physical mode (paging turning
off). This can be used to invoke BIOS code under Linux.
The following user-space tools can be used with kexec jump:
- kexec-tools needs to be patched to support kexec jump. The patches
and the precompiled kexec can be download from the following URL:
source: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-src_git_kh10.tar.bz2
patches: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec-tools-patches_git_kh10.tar.bz2
binary: http://khibernation.sourceforge.net/download/release_v10/kexec-tools/kexec_git_kh10
- makedumpfile with patches are used as memory image saving tool, it
can exclude free pages from original kernel memory image file. The
patches and the precompiled makedumpfile can be download from the
following URL:
source: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile-src_cvs_kh10.tar.bz2
patches: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile-patches_cvs_kh10.tar.bz2
binary: http://khibernation.sourceforge.net/download/release_v10/makedumpfile/makedumpfile_cvs_kh10
- An initramfs image can be used as the root file system of kexeced
kernel. An initramfs image built with "BuildRoot" can be downloaded
from the following URL:
initramfs image: http://khibernation.sourceforge.net/download/release_v10/initramfs/rootfs_cvs_kh10.gz
All user space tools above are included in the initramfs image.
Usage example of simple hibernation:
1. Compile and install patched kernel with following options selected:
CONFIG_X86_32=y
CONFIG_RELOCATABLE=y
CONFIG_KEXEC=y
CONFIG_CRASH_DUMP=y
CONFIG_PM=y
CONFIG_HIBERNATION=y
CONFIG_KEXEC_JUMP=y
2. Build an initramfs image contains kexec-tool and makedumpfile, or
download the pre-built initramfs image, called rootfs.gz in
following text.
3. Prepare a partition to save memory image of original kernel, called
hibernating partition in following text.
4. Boot kernel compiled in step 1 (kernel A).
5. In the kernel A, load kernel compiled in step 1 (kernel B) with
/sbin/kexec. The shell command line can be as follow:
/sbin/kexec --load-preserve-context /boot/bzImage --mem-min=0x100000
--mem-max=0xffffff --initrd=rootfs.gz
6. Boot the kernel B with following shell command line:
/sbin/kexec -e
7. The kernel B will boot as normal kexec. In kernel B the memory
image of kernel A can be saved into hibernating partition as
follow:
jump_back_entry=`cat /proc/cmdline | tr ' ' '\n' | grep kexec_jump_back_entry | cut -d '='`
echo $jump_back_entry > kexec_jump_back_entry
cp /proc/vmcore dump.elf
Then you can shutdown the machine as normal.
8. Boot kernel compiled in step 1 (kernel C). Use the rootfs.gz as
root file system.
9. In kernel C, load the memory image of kernel A as follow:
/sbin/kexec -l --args-none --entry=`cat kexec_jump_back_entry` dump.elf
10. Jump back to the kernel A as follow:
/sbin/kexec -e
Then, kernel A is resumed.
Implementation point:
To support jumping between two kernels, before jumping to (executing)
the new kernel and jumping back to the original kernel, the devices
are put into quiescent state, and the state of devices and CPU is
saved. After jumping back from kexeced kernel and jumping to the new
kernel, the state of devices and CPU are restored accordingly. The
devices/CPU state save/restore code of software suspend is called to
implement corresponding function.
Known issues:
- Because the segment number supported by sys_kexec_load is limited,
hibernation image with many segments may not be load. This is
planned to be eliminated by adding a new flag to sys_kexec_load to
make a image can be loaded with multiple sys_kexec_load invoking.
Now, only the i386 architecture is supported.
Signed-off-by: Huang Ying <ying.huang@intel.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Nigel Cunningham <nigel@nigel.suspend2.net>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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>
Sudeep Holla