linux/kernel/power/hibernate.c
Linus Torvalds 0b8417c141 Power management updates for 5.10-rc1
- Rework cpufreq statistics collection to allow it to take place
    when fast frequency switching is enabled in the governor (Viresh
    Kumar).
 
  - Make the cpufreq core set the frequency scale on behalf of the
    driver and update several cpufreq drivers accordingly (Ionela
    Voinescu, Valentin Schneider).
 
  - Add new hardware support to the STI and qcom cpufreq drivers and
    improve them (Alain Volmat, Manivannan Sadhasivam).
 
  - Fix multiple assorted issues in cpufreq drivers (Jon Hunter,
    Krzysztof Kozlowski, Matthias Kaehlcke, Pali Rohár, Stephan
    Gerhold, Viresh Kumar).
 
  - Fix several assorted issues in the operating performance points
    (OPP) framework (Stephan Gerhold, Viresh Kumar).
 
  - Allow devfreq drivers to fetch devfreq instances by DT enumeration
    instead of using explicit phandles and modify the devfreq core
    code to support driver-specific devfreq DT bindings (Leonard
    Crestez, Chanwoo Choi).
 
  - Improve initial hardware resetting in the tegra30 devfreq driver
    and clean up the tegra cpuidle driver (Dmitry Osipenko).
 
  - Update the cpuidle core to collect state entry rejection
    statistics and expose them via sysfs (Lina Iyer).
 
  - Improve the ACPI _CST code handling diagnostics (Chen Yu).
 
  - Update the PSCI cpuidle driver to allow the PM domain
    initialization to occur in the OSI mode as well as in the PC
    mode (Ulf Hansson).
 
  - Rework the generic power domains (genpd) core code to allow
    domain power off transition to be aborted in the absence of the
    "power off" domain callback (Ulf Hansson).
 
  - Fix two suspend-to-idle issues in the ACPI EC driver (Rafael
    Wysocki).
 
  - Fix the handling of timer_expires in the PM-runtime framework on
    32-bit systems and the handling of device links in it (Grygorii
    Strashko, Xiang Chen).
 
  - Add IO requests batching support to the hibernate image saving and
    reading code and drop a bogus get_gendisk() from there (Xiaoyi
    Chen, Christoph Hellwig).
 
  - Allow PCIe ports to be put into the D3cold power state if they
    are power-manageable via ACPI (Lukas Wunner).
 
  - Add missing header file include to a power capping driver (Pujin
    Shi).
 
  - Clean up the qcom-cpr AVS driver a bit (Liu Shixin).
 
  - Kevin Hilman steps down as designated reviwer of adaptive voltage
    scaling (AVS) driverrs (Kevin Hilman).
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Merge tag 'pm-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management updates from Rafael Wysocki:
 "These rework the collection of cpufreq statistics to allow it to take
  place if fast frequency switching is enabled in the governor, rework
  the frequency invariance handling in the cpufreq core and drivers, add
  new hardware support to a couple of cpufreq drivers, fix a number of
  assorted issues and clean up the code all over.

  Specifics:

   - Rework cpufreq statistics collection to allow it to take place when
     fast frequency switching is enabled in the governor (Viresh Kumar).

   - Make the cpufreq core set the frequency scale on behalf of the
     driver and update several cpufreq drivers accordingly (Ionela
     Voinescu, Valentin Schneider).

   - Add new hardware support to the STI and qcom cpufreq drivers and
     improve them (Alain Volmat, Manivannan Sadhasivam).

   - Fix multiple assorted issues in cpufreq drivers (Jon Hunter,
     Krzysztof Kozlowski, Matthias Kaehlcke, Pali Rohár, Stephan
     Gerhold, Viresh Kumar).

   - Fix several assorted issues in the operating performance points
     (OPP) framework (Stephan Gerhold, Viresh Kumar).

   - Allow devfreq drivers to fetch devfreq instances by DT enumeration
     instead of using explicit phandles and modify the devfreq core code
     to support driver-specific devfreq DT bindings (Leonard Crestez,
     Chanwoo Choi).

   - Improve initial hardware resetting in the tegra30 devfreq driver
     and clean up the tegra cpuidle driver (Dmitry Osipenko).

   - Update the cpuidle core to collect state entry rejection statistics
     and expose them via sysfs (Lina Iyer).

   - Improve the ACPI _CST code handling diagnostics (Chen Yu).

   - Update the PSCI cpuidle driver to allow the PM domain
     initialization to occur in the OSI mode as well as in the PC mode
     (Ulf Hansson).

   - Rework the generic power domains (genpd) core code to allow domain
     power off transition to be aborted in the absence of the "power
     off" domain callback (Ulf Hansson).

   - Fix two suspend-to-idle issues in the ACPI EC driver (Rafael
     Wysocki).

   - Fix the handling of timer_expires in the PM-runtime framework on
     32-bit systems and the handling of device links in it (Grygorii
     Strashko, Xiang Chen).

   - Add IO requests batching support to the hibernate image saving and
     reading code and drop a bogus get_gendisk() from there (Xiaoyi
     Chen, Christoph Hellwig).

   - Allow PCIe ports to be put into the D3cold power state if they are
     power-manageable via ACPI (Lukas Wunner).

   - Add missing header file include to a power capping driver (Pujin
     Shi).

   - Clean up the qcom-cpr AVS driver a bit (Liu Shixin).

   - Kevin Hilman steps down as designated reviwer of adaptive voltage
     scaling (AVS) drivers (Kevin Hilman)"

* tag 'pm-5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (65 commits)
  cpufreq: stats: Fix string format specifier mismatch
  arm: disable frequency invariance for CONFIG_BL_SWITCHER
  cpufreq,arm,arm64: restructure definitions of arch_set_freq_scale()
  cpufreq: stats: Add memory barrier to store_reset()
  cpufreq: schedutil: Simplify sugov_fast_switch()
  ACPI: EC: PM: Drop ec_no_wakeup check from acpi_ec_dispatch_gpe()
  ACPI: EC: PM: Flush EC work unconditionally after wakeup
  PCI/ACPI: Whitelist hotplug ports for D3 if power managed by ACPI
  PM: hibernate: remove the bogus call to get_gendisk() in software_resume()
  cpufreq: Move traces and update to policy->cur to cpufreq core
  cpufreq: stats: Enable stats for fast-switch as well
  cpufreq: stats: Mark few conditionals with unlikely()
  cpufreq: stats: Remove locking
  cpufreq: stats: Defer stats update to cpufreq_stats_record_transition()
  PM: domains: Allow to abort power off when no ->power_off() callback
  PM: domains: Rename power state enums for genpd
  PM / devfreq: tegra30: Improve initial hardware resetting
  PM / devfreq: event: Change prototype of devfreq_event_get_edev_by_phandle function
  PM / devfreq: Change prototype of devfreq_get_devfreq_by_phandle function
  PM / devfreq: Add devfreq_get_devfreq_by_node function
  ...
2020-10-14 10:45:41 -07:00

1344 lines
30 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* 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>
*/
#define pr_fmt(fmt) "PM: hibernation: " fmt
#include <linux/export.h>
#include <linux/suspend.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/nmi.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 <linux/ktime.h>
#include <linux/security.h>
#include <trace/events/power.h>
#include "power.h"
static int nocompress;
static int noresume;
static int nohibernate;
static int resume_wait;
static unsigned 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
HIBERNATION_TEST_RESUME,
/* 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;
static atomic_t hibernate_atomic = ATOMIC_INIT(1);
bool hibernate_acquire(void)
{
return atomic_add_unless(&hibernate_atomic, -1, 0);
}
void hibernate_release(void)
{
atomic_inc(&hibernate_atomic);
}
bool hibernation_available(void)
{
return nohibernate == 0 && !security_locked_down(LOCKDOWN_HIBERNATION);
}
/**
* 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();
}
EXPORT_SYMBOL_GPL(hibernation_set_ops);
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)
{
pr_info("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(PMSG_FREEZE) : 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(ktime_t start, ktime_t stop,
unsigned nr_pages, char *msg)
{
ktime_t diff;
u64 elapsed_centisecs64;
unsigned int centisecs;
unsigned int k;
unsigned int kps;
diff = ktime_sub(stop, start);
elapsed_centisecs64 = ktime_divns(diff, 10*NSEC_PER_MSEC);
centisecs = elapsed_centisecs64;
if (centisecs == 0)
centisecs = 1; /* avoid div-by-zero */
k = nr_pages * (PAGE_SIZE / 1024);
kps = (k * 100) / centisecs;
pr_info("%s %u kbytes in %u.%02u seconds (%u.%02u MB/s)\n",
msg, k, centisecs / 100, centisecs % 100, kps / 1000,
(kps % 1000) / 10);
}
__weak int arch_resume_nosmt(void)
{
return 0;
}
/**
* 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) {
pr_err("Some devices failed to power down, aborting\n");
return error;
}
error = platform_pre_snapshot(platform_mode);
if (error || hibernation_test(TEST_PLATFORM))
goto Platform_finish;
error = suspend_disable_secondary_cpus();
if (error || hibernation_test(TEST_CPUS))
goto Enable_cpus;
local_irq_disable();
system_state = SYSTEM_SUSPEND;
error = syscore_suspend();
if (error) {
pr_err("Some system devices failed to power down, aborting\n");
goto Enable_irqs;
}
if (hibernation_test(TEST_CORE) || pm_wakeup_pending())
goto Power_up;
in_suspend = 1;
save_processor_state();
trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, true);
error = swsusp_arch_suspend();
/* Restore control flow magically appears here */
restore_processor_state();
trace_suspend_resume(TPS("machine_suspend"), PM_EVENT_HIBERNATE, false);
if (error)
pr_err("Error %d creating image\n", error);
if (!in_suspend) {
events_check_enabled = false;
clear_free_pages();
}
platform_leave(platform_mode);
Power_up:
syscore_resume();
Enable_irqs:
system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
suspend_enable_secondary_cpus();
/* Allow architectures to do nosmt-specific post-resume dances */
if (!in_suspend)
error = arch_resume_nosmt();
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 system_transition_mutex held.
*/
int hibernation_snapshot(int platform_mode)
{
pm_message_t msg;
int error;
pm_suspend_clear_flags();
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();
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();
resume_console();
dpm_complete(msg);
Close:
platform_end(platform_mode);
return error;
Thaw:
thaw_kernel_threads();
Cleanup:
swsusp_free();
goto Close;
}
int __weak hibernate_resume_nonboot_cpu_disable(void)
{
return suspend_disable_secondary_cpus();
}
/**
* 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) {
pr_err("Some devices failed to power down, aborting resume\n");
return error;
}
error = platform_pre_restore(platform_mode);
if (error)
goto Cleanup;
error = hibernate_resume_nonboot_cpu_disable();
if (error)
goto Enable_cpus;
local_irq_disable();
system_state = SYSTEM_SUSPEND;
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:
system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
suspend_enable_secondary_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 system_transition_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();
pm_restrict_gfp_mask();
error = dpm_suspend_start(PMSG_QUIESCE);
if (!error) {
error = resume_target_kernel(platform_mode);
/*
* The above should either succeed and jump to the new kernel,
* or return with an error. Otherwise things are just
* undefined, so let's be paranoid.
*/
BUG_ON(!error);
}
dpm_resume_end(PMSG_RECOVER);
pm_restore_gfp_mask();
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(PMSG_HIBERNATE);
if (error)
goto Close;
entering_platform_hibernation = true;
suspend_console();
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 = suspend_disable_secondary_cpus();
if (error)
goto Enable_cpus;
local_irq_disable();
system_state = SYSTEM_SUSPEND;
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();
system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
suspend_enable_secondary_cpus();
Platform_finish:
hibernation_ops->finish();
dpm_resume_start(PMSG_RESTORE);
Resume_devices:
entering_platform_hibernation = false;
dpm_resume_end(PMSG_RESTORE);
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;
if (hibernation_mode == HIBERNATION_SUSPEND) {
error = suspend_devices_and_enter(PM_SUSPEND_MEM);
if (error) {
hibernation_mode = hibernation_ops ?
HIBERNATION_PLATFORM :
HIBERNATION_SHUTDOWN;
} else {
/* Restore swap signature. */
error = swsusp_unmark();
if (error)
pr_err("Swap will be unusable! Try swapon -a.\n");
return;
}
}
#endif
switch (hibernation_mode) {
case HIBERNATION_REBOOT:
kernel_restart(NULL);
break;
case HIBERNATION_PLATFORM:
hibernation_platform_enter();
fallthrough;
case HIBERNATION_SHUTDOWN:
if (pm_power_off)
kernel_power_off();
break;
}
kernel_halt();
/*
* Valid image is on the disk, if we continue we risk serious data
* corruption after resume.
*/
pr_crit("Power down manually\n");
while (1)
cpu_relax();
}
static int load_image_and_restore(void)
{
int error;
unsigned int flags;
pm_pr_dbg("Loading hibernation image.\n");
lock_device_hotplug();
error = create_basic_memory_bitmaps();
if (error)
goto Unlock;
error = swsusp_read(&flags);
swsusp_close(FMODE_READ);
if (!error)
error = hibernation_restore(flags & SF_PLATFORM_MODE);
pr_err("Failed to load image, recovering.\n");
swsusp_free();
free_basic_memory_bitmaps();
Unlock:
unlock_device_hotplug();
return error;
}
/**
* hibernate - Carry out system hibernation, including saving the image.
*/
int hibernate(void)
{
bool snapshot_test = false;
int error;
if (!hibernation_available()) {
pm_pr_dbg("Hibernation not available.\n");
return -EPERM;
}
lock_system_sleep();
/* The snapshot device should not be opened while we're running */
if (!hibernate_acquire()) {
error = -EBUSY;
goto Unlock;
}
pr_info("hibernation entry\n");
pm_prepare_console();
error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
if (error)
goto Restore;
ksys_sync_helper();
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;
pm_pr_dbg("Writing hibernation image.\n");
error = swsusp_write(flags);
swsusp_free();
if (!error) {
if (hibernation_mode == HIBERNATION_TEST_RESUME)
snapshot_test = true;
else
power_down();
}
in_suspend = 0;
pm_restore_gfp_mask();
} else {
pm_pr_dbg("Hibernation image restored successfully.\n");
}
Free_bitmaps:
free_basic_memory_bitmaps();
Thaw:
unlock_device_hotplug();
if (snapshot_test) {
pm_pr_dbg("Checking hibernation image\n");
error = swsusp_check();
if (!error)
error = load_image_and_restore();
}
thaw_processes();
/* Don't bother checking whether freezer_test_done is true */
freezer_test_done = false;
Exit:
pm_notifier_call_chain(PM_POST_HIBERNATION);
Restore:
pm_restore_console();
hibernate_release();
Unlock:
unlock_system_sleep();
pr_info("hibernation exit\n");
return error;
}
/**
* hibernate_quiet_exec - Execute a function with all devices frozen.
* @func: Function to execute.
* @data: Data pointer to pass to @func.
*
* Return the @func return value or an error code if it cannot be executed.
*/
int hibernate_quiet_exec(int (*func)(void *data), void *data)
{
int error;
lock_system_sleep();
if (!hibernate_acquire()) {
error = -EBUSY;
goto unlock;
}
pm_prepare_console();
error = pm_notifier_call_chain_robust(PM_HIBERNATION_PREPARE, PM_POST_HIBERNATION);
if (error)
goto restore;
error = freeze_processes();
if (error)
goto exit;
lock_device_hotplug();
pm_suspend_clear_flags();
error = platform_begin(true);
if (error)
goto thaw;
error = freeze_kernel_threads();
if (error)
goto thaw;
error = dpm_prepare(PMSG_FREEZE);
if (error)
goto dpm_complete;
suspend_console();
error = dpm_suspend(PMSG_FREEZE);
if (error)
goto dpm_resume;
error = dpm_suspend_end(PMSG_FREEZE);
if (error)
goto dpm_resume;
error = platform_pre_snapshot(true);
if (error)
goto skip;
error = func(data);
skip:
platform_finish(true);
dpm_resume_start(PMSG_THAW);
dpm_resume:
dpm_resume(PMSG_THAW);
resume_console();
dpm_complete:
dpm_complete(PMSG_THAW);
thaw_kernel_threads();
thaw:
platform_end(true);
unlock_device_hotplug();
thaw_processes();
exit:
pm_notifier_call_chain(PM_POST_HIBERNATION);
restore:
pm_restore_console();
hibernate_release();
unlock:
unlock_system_sleep();
return error;
}
EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
/**
* 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_snapshot() 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;
/*
* If the user said "noresume".. bail out early.
*/
if (noresume || !hibernation_available())
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 system_transition_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(&system_transition_mutex, SINGLE_DEPTH_NESTING);
if (swsusp_resume_device)
goto Check_image;
if (!strlen(resume_file)) {
error = -ENOENT;
goto Unlock;
}
pm_pr_dbg("Checking hibernation image partition %s\n", resume_file);
if (resume_delay) {
pr_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);
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:
pm_pr_dbg("Hibernation image partition %d:%d present\n",
MAJOR(swsusp_resume_device), MINOR(swsusp_resume_device));
pm_pr_dbg("Looking for hibernation image.\n");
error = swsusp_check();
if (error)
goto Unlock;
/* The snapshot device should not be opened while we're running */
if (!hibernate_acquire()) {
error = -EBUSY;
swsusp_close(FMODE_READ);
goto Unlock;
}
pr_info("resume from hibernation\n");
pm_prepare_console();
error = pm_notifier_call_chain_robust(PM_RESTORE_PREPARE, PM_POST_RESTORE);
if (error)
goto Restore;
pm_pr_dbg("Preparing processes for hibernation restore.\n");
error = freeze_processes();
if (error)
goto Close_Finish;
error = freeze_kernel_threads();
if (error) {
thaw_processes();
goto Close_Finish;
}
error = load_image_and_restore();
thaw_processes();
Finish:
pm_notifier_call_chain(PM_POST_RESTORE);
Restore:
pm_restore_console();
pr_info("resume failed (%d)\n", error);
hibernate_release();
/* For success case, the suspend path will release the lock */
Unlock:
mutex_unlock(&system_transition_mutex);
pm_pr_dbg("Hibernation image not present or could not be loaded.\n");
return error;
Close_Finish:
swsusp_close(FMODE_READ);
goto Finish;
}
late_initcall_sync(software_resume);
static const char * const hibernation_modes[] = {
[HIBERNATION_PLATFORM] = "platform",
[HIBERNATION_SHUTDOWN] = "shutdown",
[HIBERNATION_REBOOT] = "reboot",
#ifdef CONFIG_SUSPEND
[HIBERNATION_SUSPEND] = "suspend",
#endif
[HIBERNATION_TEST_RESUME] = "test_resume",
};
/*
* /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;
if (!hibernation_available())
return sprintf(buf, "[disabled]\n");
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
case HIBERNATION_TEST_RESUME:
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;
if (!hibernation_available())
return -EPERM;
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
case HIBERNATION_TEST_RESUME:
hibernation_mode = mode;
break;
case HIBERNATION_PLATFORM:
if (hibernation_ops)
hibernation_mode = mode;
else
error = -EINVAL;
}
} else
error = -EINVAL;
if (!error)
pm_pr_dbg("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)
{
dev_t res;
int len = n;
char *name;
if (len && buf[len-1] == '\n')
len--;
name = kstrndup(buf, len, GFP_KERNEL);
if (!name)
return -ENOMEM;
res = name_to_dev_t(name);
kfree(name);
if (!res)
return -EINVAL;
lock_system_sleep();
swsusp_resume_device = res;
unlock_system_sleep();
pm_pr_dbg("Configured hibernation resume from disk to %u\n",
swsusp_resume_device);
noresume = 0;
software_resume();
return n;
}
power_attr(resume);
static ssize_t resume_offset_show(struct kobject *kobj,
struct kobj_attribute *attr, char *buf)
{
return sprintf(buf, "%llu\n", (unsigned long long)swsusp_resume_block);
}
static ssize_t resume_offset_store(struct kobject *kobj,
struct kobj_attribute *attr, const char *buf,
size_t n)
{
unsigned long long offset;
int rc;
rc = kstrtoull(buf, 0, &offset);
if (rc)
return rc;
swsusp_resume_block = offset;
return n;
}
power_attr(resume_offset);
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_offset_attr.attr,
&resume_attr.attr,
&image_size_attr.attr,
&reserved_size_attr.attr,
NULL,
};
static const 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;
} else if (!strncmp(str, "no", 2)) {
noresume = 1;
nohibernate = 1;
} else if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)
&& !strncmp(str, "protect_image", 13)) {
enable_restore_image_protection();
}
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)
{
int rc = kstrtouint(str, 0, &resume_delay);
if (rc)
return rc;
return 1;
}
static int __init nohibernate_setup(char *str)
{
noresume = 1;
nohibernate = 1;
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);
__setup("nohibernate", nohibernate_setup);