kernel_optimize_test/kernel/power/hibernate.c
Linus Torvalds 02b9735c12 ACPI and power management fixes for 3.12-rc1
1) ACPI-based PCI hotplug (ACPIPHP) fixes related to spurious events
 
   After the recent ACPIPHP changes we've seen some interesting breakage
   on a system that triggers device check notifications during boot for
   non-existing devices.  Although those notifications are really
   spurious, we should be able to deal with them nevertheless and that
   shouldn't introduce too much overhead.  Four commits to make that
   work properly.
 
  2) Memory hotplug and hibernation mutual exclusion rework
 
   This was maent to be a cleanup, but it happens to fix a classical
   ABBA deadlock between system suspend/hibernation and ACPI memory
   hotplug which is possible if they are started roughly at the same
   time.  Three commits rework memory hotplug so that it doesn't
   acquire pm_mutex and make hibernation use device_hotplug_lock
   which prevents it from racing with memory hotplug.
 
  3) ACPI Intel LPSS (Low-Power Subsystem) driver crash fix
 
   The ACPI LPSS driver crashes during boot on Apple Macbook Air with
   Haswell that has slightly unusual BIOS configuration in which one
   of the LPSS device's _CRS method doesn't return all of the information
   expected by the driver.  Fix from Mika Westerberg, for stable.
 
  4) ACPICA fix related to Store->ArgX operation
 
   AML interpreter fix for obscure breakage that causes AML to be
   executed incorrectly on some machines (observed in practice).  From
   Bob Moore.
 
  5) ACPI core fix for PCI ACPI device objects lookup
 
   There still are cases in which there is more than one ACPI device
   object matching a given PCI device and we don't choose the one that
   the BIOS expects us to choose, so this makes the lookup take more
   criteria into account in those cases.
 
  6) Fix to prevent cpuidle from crashing in some rare cases
 
   If the result of cpuidle_get_driver() is NULL, which can happen on
   some systems, cpuidle_driver_ref() will crash trying to use that
   pointer and the Daniel Fu's fix prevents that from happening.
 
  7) cpufreq fixes related to CPU hotplug
 
   Stephen Boyd reported a number of concurrency problems with cpufreq
   related to CPU hotplug which are addressed by a series of fixes
   from Srivatsa S Bhat and Viresh Kumar.
 
  8) cpufreq fix for time conversion in time_in_state attribute
 
   Time conversion carried out by cpufreq when user space attempts to
   read /sys/devices/system/cpu/cpu*/cpufreq/stats/time_in_state won't
   work correcty if cputime_t doesn't map directly to jiffies.  Fix
   from Andreas Schwab.
 
  9) Revert of a troublesome cpufreq commit
 
   Commit 7c30ed5 (cpufreq: make sure frequency transitions are
   serialized) was intended to address some known concurrency problems
   in cpufreq related to the ordering of transitions, but unfortunately
   it introduced several problems of its own, so I decided to revert it
   now and address the original problems later in a more robust way.
 
 10) Intel Haswell CPU models for intel_pstate from Nell Hardcastle.
 
 11) cpufreq fixes related to system suspend/resume
 
   The recent cpufreq changes that made it preserve CPU sysfs attributes
   over suspend/resume cycles introduced a possible NULL pointer
   dereference that caused it to crash during the second attempt to
   suspend.  Three commits from Srivatsa S Bhat fix that problem and a
   couple of related issues.
 
 12) cpufreq locking fix
 
   cpufreq_policy_restore() should acquire the lock for reading, but
   it acquires it for writing.  Fix from Lan Tianyu.
 
 /
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v2.0.19 (GNU/Linux)
 
 iQIcBAABCAAGBQJSMbdRAAoJEKhOf7ml8uNsiFkQAKSh1iBXuiUCxBApEGZgoQio
 8lmnuyWdhNQWdjZTnh7ptjpDxdrWhxcoxvoaGABU++reDObjef1QnyrQtdO3r8dl
 oy0C/YGh5kq5SIffIDEwPIb/ipDe/47cgRMW8iBlnViDa1MJBqICuLyefcTRIrKp
 QGvv0owUM2o7TXpA10+qm8zXjv6m5mu1DTtxYI+2Eodhwi54neAqb+aKMspa2thy
 V9KFcVv3Td4rJrNvw6BhXNM81QbaYpRxaK3DRr1T6SM++EKvbqYFA1jgW24YvqTL
 nrCZlDMb6KRww5DCxA/ns9Kx5H+ZyicoRwdtAM3PBYA6MGqsLqPozC/8VKV1fSvZ
 sgUdbUSuLqKRAkOqM1bjKAhi9PdCGBvkQAg2AqbRK6IBl4HJC8xhdb5E6eZ/J42G
 GyNBpKef7wVJwYKXE2hSChZ5dYjqMizNHWxFHf8Xy1dveExbQ2nmSJmaWMy2A3kx
 YOXFkcTV5F6GOIZB8WCRruzUalff9xal4G+iVhGF+AZIOCm7bC+FDXfwIS82uVor
 ej2l+uQLLZCB499IRmM6942ZIAXshmtN7eRfGtKBc6jsbSCEdQDqf1Z7oRwqAD6h
 WkD/k/zz30CyM8y4snOkAXkZgqAQsZodtqfowE3e9OHd51tfcNiqdht+obwCx+eD
 MWXc2xATMAX6NcZTXSZS
 =U/Jw
 -----END PGP SIGNATURE-----

Merge tag 'pm+acpi-fixes-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull ACPI and power management fixes from Rafael Wysocki:
 "All of these commits are fixes that have emerged recently and some of
  them fix bugs introduced during this merge window.

  Specifics:

   1) ACPI-based PCI hotplug (ACPIPHP) fixes related to spurious events

      After the recent ACPIPHP changes we've seen some interesting
      breakage on a system that triggers device check notifications
      during boot for non-existing devices.  Although those
      notifications are really spurious, we should be able to deal with
      them nevertheless and that shouldn't introduce too much overhead.
      Four commits to make that work properly.

   2) Memory hotplug and hibernation mutual exclusion rework

      This was maent to be a cleanup, but it happens to fix a classical
      ABBA deadlock between system suspend/hibernation and ACPI memory
      hotplug which is possible if they are started roughly at the same
      time.  Three commits rework memory hotplug so that it doesn't
      acquire pm_mutex and make hibernation use device_hotplug_lock
      which prevents it from racing with memory hotplug.

   3) ACPI Intel LPSS (Low-Power Subsystem) driver crash fix

      The ACPI LPSS driver crashes during boot on Apple Macbook Air with
      Haswell that has slightly unusual BIOS configuration in which one
      of the LPSS device's _CRS method doesn't return all of the
      information expected by the driver.  Fix from Mika Westerberg, for
      stable.

   4) ACPICA fix related to Store->ArgX operation

      AML interpreter fix for obscure breakage that causes AML to be
      executed incorrectly on some machines (observed in practice).
      From Bob Moore.

   5) ACPI core fix for PCI ACPI device objects lookup

      There still are cases in which there is more than one ACPI device
      object matching a given PCI device and we don't choose the one
      that the BIOS expects us to choose, so this makes the lookup take
      more criteria into account in those cases.

   6) Fix to prevent cpuidle from crashing in some rare cases

      If the result of cpuidle_get_driver() is NULL, which can happen on
      some systems, cpuidle_driver_ref() will crash trying to use that
      pointer and the Daniel Fu's fix prevents that from happening.

   7) cpufreq fixes related to CPU hotplug

      Stephen Boyd reported a number of concurrency problems with
      cpufreq related to CPU hotplug which are addressed by a series of
      fixes from Srivatsa S Bhat and Viresh Kumar.

   8) cpufreq fix for time conversion in time_in_state attribute

      Time conversion carried out by cpufreq when user space attempts to
      read /sys/devices/system/cpu/cpu*/cpufreq/stats/time_in_state
      won't work correcty if cputime_t doesn't map directly to jiffies.
      Fix from Andreas Schwab.

   9) Revert of a troublesome cpufreq commit

      Commit 7c30ed5 (cpufreq: make sure frequency transitions are
      serialized) was intended to address some known concurrency
      problems in cpufreq related to the ordering of transitions, but
      unfortunately it introduced several problems of its own, so I
      decided to revert it now and address the original problems later
      in a more robust way.

  10) Intel Haswell CPU models for intel_pstate from Nell Hardcastle.

  11) cpufreq fixes related to system suspend/resume

      The recent cpufreq changes that made it preserve CPU sysfs
      attributes over suspend/resume cycles introduced a possible NULL
      pointer dereference that caused it to crash during the second
      attempt to suspend.  Three commits from Srivatsa S Bhat fix that
      problem and a couple of related issues.

  12) cpufreq locking fix

      cpufreq_policy_restore() should acquire the lock for reading, but
      it acquires it for writing.  Fix from Lan Tianyu"

* tag 'pm+acpi-fixes-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (25 commits)
  cpufreq: Acquire the lock in cpufreq_policy_restore() for reading
  cpufreq: Prevent problems in update_policy_cpu() if last_cpu == new_cpu
  cpufreq: Restructure if/else block to avoid unintended behavior
  cpufreq: Fix crash in cpufreq-stats during suspend/resume
  intel_pstate: Add Haswell CPU models
  Revert "cpufreq: make sure frequency transitions are serialized"
  cpufreq: Use signed type for 'ret' variable, to store negative error values
  cpufreq: Remove temporary fix for race between CPU hotplug and sysfs-writes
  cpufreq: Synchronize the cpufreq store_*() routines with CPU hotplug
  cpufreq: Invoke __cpufreq_remove_dev_finish() after releasing cpu_hotplug.lock
  cpufreq: Split __cpufreq_remove_dev() into two parts
  cpufreq: Fix wrong time unit conversion
  cpufreq: serialize calls to __cpufreq_governor()
  cpufreq: don't allow governor limits to be changed when it is disabled
  ACPI / bind: Prefer device objects with _STA to those without it
  ACPI / hotplug / PCI: Avoid parent bus rescans on spurious device checks
  ACPI / hotplug / PCI: Use _OST to notify firmware about notify status
  ACPI / hotplug / PCI: Avoid doing too much for spurious notifies
  ACPICA: Fix for a Store->ArgX when ArgX contains a reference to a field.
  ACPI / hotplug / PCI: Don't trim devices before scanning the namespace
  ...
2013-09-12 11:22:45 -07:00

1119 lines
26 KiB
C

/*
* kernel/power/hibernate.c - Hibernation (a.k.a suspend-to-disk) support.
*
* Copyright (c) 2003 Patrick Mochel
* Copyright (c) 2003 Open Source Development Lab
* Copyright (c) 2004 Pavel Machek <pavel@ucw.cz>
* Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
* Copyright (C) 2012 Bojan Smojver <bojan@rexursive.com>
*
* This file is released under the GPLv2.
*/
#include <linux/export.h>
#include <linux/suspend.h>
#include <linux/syscalls.h>
#include <linux/reboot.h>
#include <linux/string.h>
#include <linux/device.h>
#include <linux/async.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/pm.h>
#include <linux/console.h>
#include <linux/cpu.h>
#include <linux/freezer.h>
#include <linux/gfp.h>
#include <linux/syscore_ops.h>
#include <linux/ctype.h>
#include <linux/genhd.h>
#include "power.h"
static int nocompress;
static int noresume;
static int resume_wait;
static int resume_delay;
static char resume_file[256] = CONFIG_PM_STD_PARTITION;
dev_t swsusp_resume_device;
sector_t swsusp_resume_block;
__visible int in_suspend __nosavedata;
enum {
HIBERNATION_INVALID,
HIBERNATION_PLATFORM,
HIBERNATION_SHUTDOWN,
HIBERNATION_REBOOT,
#ifdef CONFIG_SUSPEND
HIBERNATION_SUSPEND,
#endif
/* keep last */
__HIBERNATION_AFTER_LAST
};
#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
static int hibernation_mode = HIBERNATION_SHUTDOWN;
bool freezer_test_done;
static const struct platform_hibernation_ops *hibernation_ops;
/**
* hibernation_set_ops - Set the global hibernate operations.
* @ops: Hibernation operations to use in subsequent hibernation transitions.
*/
void hibernation_set_ops(const struct platform_hibernation_ops *ops)
{
if (ops && !(ops->begin && ops->end && ops->pre_snapshot
&& ops->prepare && ops->finish && ops->enter && ops->pre_restore
&& ops->restore_cleanup && ops->leave)) {
WARN_ON(1);
return;
}
lock_system_sleep();
hibernation_ops = ops;
if (ops)
hibernation_mode = HIBERNATION_PLATFORM;
else if (hibernation_mode == HIBERNATION_PLATFORM)
hibernation_mode = HIBERNATION_SHUTDOWN;
unlock_system_sleep();
}
static bool entering_platform_hibernation;
bool system_entering_hibernation(void)
{
return entering_platform_hibernation;
}
EXPORT_SYMBOL(system_entering_hibernation);
#ifdef CONFIG_PM_DEBUG
static void hibernation_debug_sleep(void)
{
printk(KERN_INFO "hibernation debug: Waiting for 5 seconds.\n");
mdelay(5000);
}
static int hibernation_test(int level)
{
if (pm_test_level == level) {
hibernation_debug_sleep();
return 1;
}
return 0;
}
#else /* !CONFIG_PM_DEBUG */
static int hibernation_test(int level) { return 0; }
#endif /* !CONFIG_PM_DEBUG */
/**
* platform_begin - Call platform to start hibernation.
* @platform_mode: Whether or not to use the platform driver.
*/
static int platform_begin(int platform_mode)
{
return (platform_mode && hibernation_ops) ?
hibernation_ops->begin() : 0;
}
/**
* platform_end - Call platform to finish transition to the working state.
* @platform_mode: Whether or not to use the platform driver.
*/
static void platform_end(int platform_mode)
{
if (platform_mode && hibernation_ops)
hibernation_ops->end();
}
/**
* platform_pre_snapshot - Call platform to prepare the machine for hibernation.
* @platform_mode: Whether or not to use the platform driver.
*
* Use the platform driver to prepare the system for creating a hibernate image,
* if so configured, and return an error code if that fails.
*/
static int platform_pre_snapshot(int platform_mode)
{
return (platform_mode && hibernation_ops) ?
hibernation_ops->pre_snapshot() : 0;
}
/**
* platform_leave - Call platform to prepare a transition to the working state.
* @platform_mode: Whether or not to use the platform driver.
*
* Use the platform driver prepare to prepare the machine for switching to the
* normal mode of operation.
*
* This routine is called on one CPU with interrupts disabled.
*/
static void platform_leave(int platform_mode)
{
if (platform_mode && hibernation_ops)
hibernation_ops->leave();
}
/**
* platform_finish - Call platform to switch the system to the working state.
* @platform_mode: Whether or not to use the platform driver.
*
* Use the platform driver to switch the machine to the normal mode of
* operation.
*
* This routine must be called after platform_prepare().
*/
static void platform_finish(int platform_mode)
{
if (platform_mode && hibernation_ops)
hibernation_ops->finish();
}
/**
* platform_pre_restore - Prepare for hibernate image restoration.
* @platform_mode: Whether or not to use the platform driver.
*
* Use the platform driver to prepare the system for resume from a hibernation
* image.
*
* If the restore fails after this function has been called,
* platform_restore_cleanup() must be called.
*/
static int platform_pre_restore(int platform_mode)
{
return (platform_mode && hibernation_ops) ?
hibernation_ops->pre_restore() : 0;
}
/**
* platform_restore_cleanup - Switch to the working state after failing restore.
* @platform_mode: Whether or not to use the platform driver.
*
* Use the platform driver to switch the system to the normal mode of operation
* after a failing restore.
*
* If platform_pre_restore() has been called before the failing restore, this
* function must be called too, regardless of the result of
* platform_pre_restore().
*/
static void platform_restore_cleanup(int platform_mode)
{
if (platform_mode && hibernation_ops)
hibernation_ops->restore_cleanup();
}
/**
* platform_recover - Recover from a failure to suspend devices.
* @platform_mode: Whether or not to use the platform driver.
*/
static void platform_recover(int platform_mode)
{
if (platform_mode && hibernation_ops && hibernation_ops->recover)
hibernation_ops->recover();
}
/**
* swsusp_show_speed - Print time elapsed between two events during hibernation.
* @start: Starting event.
* @stop: Final event.
* @nr_pages: Number of memory pages processed between @start and @stop.
* @msg: Additional diagnostic message to print.
*/
void swsusp_show_speed(struct timeval *start, struct timeval *stop,
unsigned nr_pages, char *msg)
{
s64 elapsed_centisecs64;
int centisecs;
int k;
int kps;
elapsed_centisecs64 = timeval_to_ns(stop) - timeval_to_ns(start);
do_div(elapsed_centisecs64, NSEC_PER_SEC / 100);
centisecs = elapsed_centisecs64;
if (centisecs == 0)
centisecs = 1; /* avoid div-by-zero */
k = nr_pages * (PAGE_SIZE / 1024);
kps = (k * 100) / centisecs;
printk(KERN_INFO "PM: %s %d kbytes in %d.%02d seconds (%d.%02d MB/s)\n",
msg, k,
centisecs / 100, centisecs % 100,
kps / 1000, (kps % 1000) / 10);
}
/**
* create_image - Create a hibernation image.
* @platform_mode: Whether or not to use the platform driver.
*
* Execute device drivers' "late" and "noirq" freeze callbacks, create a
* hibernation image and run the drivers' "noirq" and "early" thaw callbacks.
*
* Control reappears in this routine after the subsequent restore.
*/
static int create_image(int platform_mode)
{
int error;
error = dpm_suspend_end(PMSG_FREEZE);
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down, "
"aborting hibernation\n");
return error;
}
error = platform_pre_snapshot(platform_mode);
if (error || hibernation_test(TEST_PLATFORM))
goto Platform_finish;
error = disable_nonboot_cpus();
if (error || hibernation_test(TEST_CPUS))
goto Enable_cpus;
local_irq_disable();
error = syscore_suspend();
if (error) {
printk(KERN_ERR "PM: Some system devices failed to power down, "
"aborting hibernation\n");
goto Enable_irqs;
}
if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
goto Power_up;
in_suspend = 1;
save_processor_state();
error = swsusp_arch_suspend();
if (error)
printk(KERN_ERR "PM: Error %d creating hibernation image\n",
error);
/* Restore control flow magically appears here */
restore_processor_state();
if (!in_suspend) {
events_check_enabled = false;
platform_leave(platform_mode);
}
Power_up:
syscore_resume();
Enable_irqs:
local_irq_enable();
Enable_cpus:
enable_nonboot_cpus();
Platform_finish:
platform_finish(platform_mode);
dpm_resume_start(in_suspend ?
(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
return error;
}
/**
* hibernation_snapshot - Quiesce devices and create a hibernation image.
* @platform_mode: If set, use platform driver to prepare for the transition.
*
* This routine must be called with pm_mutex held.
*/
int hibernation_snapshot(int platform_mode)
{
pm_message_t msg;
int error;
error = platform_begin(platform_mode);
if (error)
goto Close;
/* Preallocate image memory before shutting down devices. */
error = hibernate_preallocate_memory();
if (error)
goto Close;
error = freeze_kernel_threads();
if (error)
goto Cleanup;
if (hibernation_test(TEST_FREEZER)) {
/*
* Indicate to the caller that we are returning due to a
* successful freezer test.
*/
freezer_test_done = true;
goto Thaw;
}
error = dpm_prepare(PMSG_FREEZE);
if (error) {
dpm_complete(PMSG_RECOVER);
goto Thaw;
}
suspend_console();
ftrace_stop();
pm_restrict_gfp_mask();
error = dpm_suspend(PMSG_FREEZE);
if (error || hibernation_test(TEST_DEVICES))
platform_recover(platform_mode);
else
error = create_image(platform_mode);
/*
* In the case that we call create_image() above, the control
* returns here (1) after the image has been created or the
* image creation has failed and (2) after a successful restore.
*/
/* We may need to release the preallocated image pages here. */
if (error || !in_suspend)
swsusp_free();
msg = in_suspend ? (error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE;
dpm_resume(msg);
if (error || !in_suspend)
pm_restore_gfp_mask();
ftrace_start();
resume_console();
dpm_complete(msg);
Close:
platform_end(platform_mode);
return error;
Thaw:
thaw_kernel_threads();
Cleanup:
swsusp_free();
goto Close;
}
/**
* resume_target_kernel - Restore system state from a hibernation image.
* @platform_mode: Whether or not to use the platform driver.
*
* Execute device drivers' "noirq" and "late" freeze callbacks, restore the
* contents of highmem that have not been restored yet from the image and run
* the low-level code that will restore the remaining contents of memory and
* switch to the just restored target kernel.
*/
static int resume_target_kernel(bool platform_mode)
{
int error;
error = dpm_suspend_end(PMSG_QUIESCE);
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down, "
"aborting resume\n");
return error;
}
error = platform_pre_restore(platform_mode);
if (error)
goto Cleanup;
error = disable_nonboot_cpus();
if (error)
goto Enable_cpus;
local_irq_disable();
error = syscore_suspend();
if (error)
goto Enable_irqs;
save_processor_state();
error = restore_highmem();
if (!error) {
error = swsusp_arch_resume();
/*
* The code below is only ever reached in case of a failure.
* Otherwise, execution continues at the place where
* swsusp_arch_suspend() was called.
*/
BUG_ON(!error);
/*
* This call to restore_highmem() reverts the changes made by
* the previous one.
*/
restore_highmem();
}
/*
* The only reason why swsusp_arch_resume() can fail is memory being
* very tight, so we have to free it as soon as we can to avoid
* subsequent failures.
*/
swsusp_free();
restore_processor_state();
touch_softlockup_watchdog();
syscore_resume();
Enable_irqs:
local_irq_enable();
Enable_cpus:
enable_nonboot_cpus();
Cleanup:
platform_restore_cleanup(platform_mode);
dpm_resume_start(PMSG_RECOVER);
return error;
}
/**
* hibernation_restore - Quiesce devices and restore from a hibernation image.
* @platform_mode: If set, use platform driver to prepare for the transition.
*
* This routine must be called with pm_mutex held. If it is successful, control
* reappears in the restored target kernel in hibernation_snapshot().
*/
int hibernation_restore(int platform_mode)
{
int error;
pm_prepare_console();
suspend_console();
ftrace_stop();
pm_restrict_gfp_mask();
error = dpm_suspend_start(PMSG_QUIESCE);
if (!error) {
error = resume_target_kernel(platform_mode);
dpm_resume_end(PMSG_RECOVER);
}
pm_restore_gfp_mask();
ftrace_start();
resume_console();
pm_restore_console();
return error;
}
/**
* hibernation_platform_enter - Power off the system using the platform driver.
*/
int hibernation_platform_enter(void)
{
int error;
if (!hibernation_ops)
return -ENOSYS;
/*
* We have cancelled the power transition by running
* hibernation_ops->finish() before saving the image, so we should let
* the firmware know that we're going to enter the sleep state after all
*/
error = hibernation_ops->begin();
if (error)
goto Close;
entering_platform_hibernation = true;
suspend_console();
ftrace_stop();
error = dpm_suspend_start(PMSG_HIBERNATE);
if (error) {
if (hibernation_ops->recover)
hibernation_ops->recover();
goto Resume_devices;
}
error = dpm_suspend_end(PMSG_HIBERNATE);
if (error)
goto Resume_devices;
error = hibernation_ops->prepare();
if (error)
goto Platform_finish;
error = disable_nonboot_cpus();
if (error)
goto Platform_finish;
local_irq_disable();
syscore_suspend();
if (pm_wakeup_pending()) {
error = -EAGAIN;
goto Power_up;
}
hibernation_ops->enter();
/* We should never get here */
while (1);
Power_up:
syscore_resume();
local_irq_enable();
enable_nonboot_cpus();
Platform_finish:
hibernation_ops->finish();
dpm_resume_start(PMSG_RESTORE);
Resume_devices:
entering_platform_hibernation = false;
dpm_resume_end(PMSG_RESTORE);
ftrace_start();
resume_console();
Close:
hibernation_ops->end();
return error;
}
/**
* power_down - Shut the machine down for hibernation.
*
* Use the platform driver, if configured, to put the system into the sleep
* state corresponding to hibernation, or try to power it off or reboot,
* depending on the value of hibernation_mode.
*/
static void power_down(void)
{
#ifdef CONFIG_SUSPEND
int error;
#endif
switch (hibernation_mode) {
case HIBERNATION_REBOOT:
kernel_restart(NULL);
break;
case HIBERNATION_PLATFORM:
hibernation_platform_enter();
case HIBERNATION_SHUTDOWN:
kernel_power_off();
break;
#ifdef CONFIG_SUSPEND
case HIBERNATION_SUSPEND:
error = suspend_devices_and_enter(PM_SUSPEND_MEM);
if (error) {
if (hibernation_ops)
hibernation_mode = HIBERNATION_PLATFORM;
else
hibernation_mode = HIBERNATION_SHUTDOWN;
power_down();
}
/*
* Restore swap signature.
*/
error = swsusp_unmark();
if (error)
printk(KERN_ERR "PM: Swap will be unusable! "
"Try swapon -a.\n");
return;
#endif
}
kernel_halt();
/*
* Valid image is on the disk, if we continue we risk serious data
* corruption after resume.
*/
printk(KERN_CRIT "PM: Please power down manually\n");
while(1);
}
/**
* hibernate - Carry out system hibernation, including saving the image.
*/
int hibernate(void)
{
int error;
lock_system_sleep();
/* The snapshot device should not be opened while we're running */
if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
error = -EBUSY;
goto Unlock;
}
pm_prepare_console();
error = pm_notifier_call_chain(PM_HIBERNATION_PREPARE);
if (error)
goto Exit;
printk(KERN_INFO "PM: Syncing filesystems ... ");
sys_sync();
printk("done.\n");
error = freeze_processes();
if (error)
goto Exit;
lock_device_hotplug();
/* Allocate memory management structures */
error = create_basic_memory_bitmaps();
if (error)
goto Thaw;
error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
if (error || freezer_test_done)
goto Free_bitmaps;
if (in_suspend) {
unsigned int flags = 0;
if (hibernation_mode == HIBERNATION_PLATFORM)
flags |= SF_PLATFORM_MODE;
if (nocompress)
flags |= SF_NOCOMPRESS_MODE;
else
flags |= SF_CRC32_MODE;
pr_debug("PM: writing image.\n");
error = swsusp_write(flags);
swsusp_free();
if (!error)
power_down();
in_suspend = 0;
pm_restore_gfp_mask();
} else {
pr_debug("PM: Image restored successfully.\n");
}
Free_bitmaps:
free_basic_memory_bitmaps();
Thaw:
unlock_device_hotplug();
thaw_processes();
/* Don't bother checking whether freezer_test_done is true */
freezer_test_done = false;
Exit:
pm_notifier_call_chain(PM_POST_HIBERNATION);
pm_restore_console();
atomic_inc(&snapshot_device_available);
Unlock:
unlock_system_sleep();
return error;
}
/**
* software_resume - Resume from a saved hibernation image.
*
* This routine is called as a late initcall, when all devices have been
* discovered and initialized already.
*
* The image reading code is called to see if there is a hibernation image
* available for reading. If that is the case, devices are quiesced and the
* contents of memory is restored from the saved image.
*
* If this is successful, control reappears in the restored target kernel in
* hibernation_snaphot() which returns to hibernate(). Otherwise, the routine
* attempts to recover gracefully and make the kernel return to the normal mode
* of operation.
*/
static int software_resume(void)
{
int error;
unsigned int flags;
/*
* If the user said "noresume".. bail out early.
*/
if (noresume)
return 0;
/*
* name_to_dev_t() below takes a sysfs buffer mutex when sysfs
* is configured into the kernel. Since the regular hibernate
* trigger path is via sysfs which takes a buffer mutex before
* calling hibernate functions (which take pm_mutex) this can
* cause lockdep to complain about a possible ABBA deadlock
* which cannot happen since we're in the boot code here and
* sysfs can't be invoked yet. Therefore, we use a subclass
* here to avoid lockdep complaining.
*/
mutex_lock_nested(&pm_mutex, SINGLE_DEPTH_NESTING);
if (swsusp_resume_device)
goto Check_image;
if (!strlen(resume_file)) {
error = -ENOENT;
goto Unlock;
}
pr_debug("PM: Checking hibernation image partition %s\n", resume_file);
if (resume_delay) {
printk(KERN_INFO "Waiting %dsec before reading resume device...\n",
resume_delay);
ssleep(resume_delay);
}
/* Check if the device is there */
swsusp_resume_device = name_to_dev_t(resume_file);
/*
* name_to_dev_t is ineffective to verify parition if resume_file is in
* integer format. (e.g. major:minor)
*/
if (isdigit(resume_file[0]) && resume_wait) {
int partno;
while (!get_gendisk(swsusp_resume_device, &partno))
msleep(10);
}
if (!swsusp_resume_device) {
/*
* Some device discovery might still be in progress; we need
* to wait for this to finish.
*/
wait_for_device_probe();
if (resume_wait) {
while ((swsusp_resume_device = name_to_dev_t(resume_file)) == 0)
msleep(10);
async_synchronize_full();
}
swsusp_resume_device = name_to_dev_t(resume_file);
if (!swsusp_resume_device) {
error = -ENODEV;
goto Unlock;
}
}
Check_image:
pr_debug("PM: Hibernation image partition %d:%d present\n",
MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
pr_debug("PM: Looking for hibernation image.\n");
error = swsusp_check();
if (error)
goto Unlock;
/* The snapshot device should not be opened while we're running */
if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
error = -EBUSY;
swsusp_close(FMODE_READ);
goto Unlock;
}
pm_prepare_console();
error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
if (error)
goto Close_Finish;
pr_debug("PM: Preparing processes for restore.\n");
error = freeze_processes();
if (error)
goto Close_Finish;
pr_debug("PM: Loading hibernation image.\n");
lock_device_hotplug();
error = create_basic_memory_bitmaps();
if (error)
goto Thaw;
error = swsusp_read(&flags);
swsusp_close(FMODE_READ);
if (!error)
hibernation_restore(flags & SF_PLATFORM_MODE);
printk(KERN_ERR "PM: Failed to load hibernation image, recovering.\n");
swsusp_free();
free_basic_memory_bitmaps();
Thaw:
unlock_device_hotplug();
thaw_processes();
Finish:
pm_notifier_call_chain(PM_POST_RESTORE);
pm_restore_console();
atomic_inc(&snapshot_device_available);
/* For success case, the suspend path will release the lock */
Unlock:
mutex_unlock(&pm_mutex);
pr_debug("PM: Hibernation image not present or could not be loaded.\n");
return error;
Close_Finish:
swsusp_close(FMODE_READ);
goto Finish;
}
late_initcall(software_resume);
static const char * const hibernation_modes[] = {
[HIBERNATION_PLATFORM] = "platform",
[HIBERNATION_SHUTDOWN] = "shutdown",
[HIBERNATION_REBOOT] = "reboot",
#ifdef CONFIG_SUSPEND
[HIBERNATION_SUSPEND] = "suspend",
#endif
};
/*
* /sys/power/disk - Control hibernation mode.
*
* Hibernation can be handled in several ways. There are a few different ways
* to put the system into the sleep state: using the platform driver (e.g. ACPI
* or other hibernation_ops), powering it off or rebooting it (for testing
* mostly).
*
* The sysfs file /sys/power/disk provides an interface for selecting the
* hibernation mode to use. Reading from this file causes the available modes
* to be printed. There are 3 modes that can be supported:
*
* 'platform'
* 'shutdown'
* 'reboot'
*
* If a platform hibernation driver is in use, 'platform' will be supported
* and will be used by default. Otherwise, 'shutdown' will be used by default.
* The selected option (i.e. the one corresponding to the current value of
* hibernation_mode) is enclosed by a square bracket.
*
* To select a given hibernation mode it is necessary to write the mode's
* string representation (as returned by reading from /sys/power/disk) back
* into /sys/power/disk.
*/
static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
int i;
char *start = buf;
for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
if (!hibernation_modes[i])
continue;
switch (i) {
case HIBERNATION_SHUTDOWN:
case HIBERNATION_REBOOT:
#ifdef CONFIG_SUSPEND
case HIBERNATION_SUSPEND:
#endif
break;
case HIBERNATION_PLATFORM:
if (hibernation_ops)
break;
/* not a valid mode, continue with loop */
continue;
}
if (i == hibernation_mode)
buf += sprintf(buf, "[%s] ", hibernation_modes[i]);
else
buf += sprintf(buf, "%s ", hibernation_modes[i]);
}
buf += sprintf(buf, "\n");
return buf-start;
}
static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
int error = 0;
int i;
int len;
char *p;
int mode = HIBERNATION_INVALID;
p = memchr(buf, '\n', n);
len = p ? p - buf : n;
lock_system_sleep();
for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) {
if (len == strlen(hibernation_modes[i])
&& !strncmp(buf, hibernation_modes[i], len)) {
mode = i;
break;
}
}
if (mode != HIBERNATION_INVALID) {
switch (mode) {
case HIBERNATION_SHUTDOWN:
case HIBERNATION_REBOOT:
#ifdef CONFIG_SUSPEND
case HIBERNATION_SUSPEND:
#endif
hibernation_mode = mode;
break;
case HIBERNATION_PLATFORM:
if (hibernation_ops)
hibernation_mode = mode;
else
error = -EINVAL;
}
} else
error = -EINVAL;
if (!error)
pr_debug("PM: Hibernation mode set to '%s'\n",
hibernation_modes[mode]);
unlock_system_sleep();
return error ? error : n;
}
power_attr(disk);
static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
MINOR(swsusp_resume_device));
}
static ssize_t resume_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
unsigned int maj, min;
dev_t res;
int ret = -EINVAL;
if (sscanf(buf, "%u:%u", &maj, &min) != 2)
goto out;
res = MKDEV(maj,min);
if (maj != MAJOR(res) || min != MINOR(res))
goto out;
lock_system_sleep();
swsusp_resume_device = res;
unlock_system_sleep();
printk(KERN_INFO "PM: Starting manual resume from disk\n");
noresume = 0;
software_resume();
ret = n;
out:
return ret;
}
power_attr(resume);
static ssize_t image_size_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
return sprintf(buf, "%lu\n", image_size);
}
static ssize_t image_size_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
unsigned long size;
if (sscanf(buf, "%lu", &size) == 1) {
image_size = size;
return n;
}
return -EINVAL;
}
power_attr(image_size);
static ssize_t reserved_size_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return sprintf(buf, "%lu\n", reserved_size);
}
static ssize_t reserved_size_store(struct kobject *kobj,
struct kobj_attribute *attr,
const char *buf, size_t n)
{
unsigned long size;
if (sscanf(buf, "%lu", &size) == 1) {
reserved_size = size;
return n;
}
return -EINVAL;
}
power_attr(reserved_size);
static struct attribute * g[] = {
&disk_attr.attr,
&resume_attr.attr,
&image_size_attr.attr,
&reserved_size_attr.attr,
NULL,
};
static struct attribute_group attr_group = {
.attrs = g,
};
static int __init pm_disk_init(void)
{
return sysfs_create_group(power_kobj, &attr_group);
}
core_initcall(pm_disk_init);
static int __init resume_setup(char *str)
{
if (noresume)
return 1;
strncpy( resume_file, str, 255 );
return 1;
}
static int __init resume_offset_setup(char *str)
{
unsigned long long offset;
if (noresume)
return 1;
if (sscanf(str, "%llu", &offset) == 1)
swsusp_resume_block = offset;
return 1;
}
static int __init hibernate_setup(char *str)
{
if (!strncmp(str, "noresume", 8))
noresume = 1;
else if (!strncmp(str, "nocompress", 10))
nocompress = 1;
return 1;
}
static int __init noresume_setup(char *str)
{
noresume = 1;
return 1;
}
static int __init resumewait_setup(char *str)
{
resume_wait = 1;
return 1;
}
static int __init resumedelay_setup(char *str)
{
resume_delay = simple_strtoul(str, NULL, 0);
return 1;
}
__setup("noresume", noresume_setup);
__setup("resume_offset=", resume_offset_setup);
__setup("resume=", resume_setup);
__setup("hibernate=", hibernate_setup);
__setup("resumewait", resumewait_setup);
__setup("resumedelay=", resumedelay_setup);