// 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 <[email protected]>
* Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
* Copyright (C) 2012 Bojan Smojver <[email protected]>
*/
#define pr_fmt(fmt) "PM: hibernation: " fmt
#include <linux/blkdev.h>
#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/ktime.h>
#include <linux/security.h>
#include <linux/secretmem.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;
static char hibernate_compressor[CRYPTO_MAX_ALG_NAME] = CONFIG_HIBERNATION_DEF_COMP;
/*
* Compression/decompression algorithm to be used while saving/loading
* image to/from disk. This would later be used in 'kernel/power/swap.c'
* to allocate comp streams.
*/
char hib_comp_algo[CRYPTO_MAX_ALG_NAME];
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) &&
!secretmem_active() && !cxl_mem_active();
}
/**
* 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)
{
unsigned int sleep_flags;
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;
}
sleep_flags = 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(sleep_flags);
}
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 = pm_sleep_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_or_poison_free_pages();
}
platform_leave(platform_mode);
Power_up:
syscore_resume();
Enable_irqs:
system_state = SYSTEM_RUNNING;
local_irq_enable();
Enable_cpus:
pm_sleep_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;
cpuidle_pause();
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:
pm_sleep_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 = pm_sleep_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:
pm_sleep_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)
{
int error;
#ifdef CONFIG_SUSPEND
if (hibernation_mode == HIBERNATION_SUSPEND) {
error = suspend_devices_and_enter(mem_sleep_current);
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:
error = hibernation_platform_enter();
if (error == -EAGAIN || error == -EBUSY) {
swsusp_unmark();
events_check_enabled = false;
pr_info("Wakeup event detected during hibernation, rolling back.\n");
return;
}
fallthrough;
case HIBERNATION_SHUTDOWN:
if (kernel_can_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) {
swsusp_close();
goto Unlock;
}
error = swsusp_read(&flags);
swsusp_close();
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;
}
#define COMPRESSION_ALGO_LZO "lzo"
#define COMPRESSION_ALGO_LZ4 "lz4"
/**
* hibernate - Carry out system hibernation, including saving the image.
*/
int hibernate(void)
{
bool snapshot_test = false;
unsigned int sleep_flags;
int error;
if (!hibernation_available()) {
pm_pr_dbg("Hibernation not available.\n");
return -EPERM;
}
/*
* Query for the compression algorithm support if compression is enabled.
*/
if (!nocompress) {
strscpy(hib_comp_algo, hibernate_compressor, sizeof(hib_comp_algo));
if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) {
pr_err("%s compression is not available\n", hib_comp_algo);
return -EOPNOTSUPP;
}
}
sleep_flags = 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;
/*
* By default, LZO compression is enabled. Use SF_COMPRESSION_ALG_LZ4
* to override this behaviour and use LZ4.
*
* Refer kernel/power/power.h for more details
*/
if (!strcmp(hib_comp_algo, COMPRESSION_ALGO_LZ4))
flags |= SF_COMPRESSION_ALG_LZ4;
else
flags |= SF_COMPRESSION_ALG_LZO;
}
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(false);
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(sleep_flags);
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)
{
unsigned int sleep_flags;
int error;
sleep_flags = 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(sleep_flags);
return error;
}
EXPORT_SYMBOL_GPL(hibernate_quiet_exec);
static int __init find_resume_device(void)
{
if (!strlen(resume_file))
return -ENOENT;
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 */
if (!early_lookup_bdev(resume_file, &swsusp_resume_device))
return 0;
/*
* Some device discovery might still be in progress; we need to wait for
* this to finish.
*/
wait_for_device_probe();
if (resume_wait) {
while (early_lookup_bdev(resume_file, &swsusp_resume_device))
msleep(10);
async_synchronize_full();
}
return early_lookup_bdev(resume_file, &swsusp_resume_device);
}
static int software_resume(void)
{
int error;
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");
mutex_lock(&system_transition_mutex);
error = swsusp_check(true);
if (error)
goto Unlock;
/*
* Check if the hibernation image is compressed. If so, query for
* the algorithm support.
*/
if (!(swsusp_header_flags & SF_NOCOMPRESS_MODE)) {
if (swsusp_header_flags & SF_COMPRESSION_ALG_LZ4)
strscpy(hib_comp_algo, COMPRESSION_ALGO_LZ4, sizeof(hib_comp_algo));
else
strscpy(hib_comp_algo, COMPRESSION_ALGO_LZO, sizeof(hib_comp_algo));
if (crypto_has_comp(hib_comp_algo, 0, 0) != 1) {
pr_err("%s compression is not available\n", hib_comp_algo);
error = -EOPNOTSUPP;
goto Unlock;
}
}
/* The snapshot device should not be opened while we're running */
if (!hibernate_acquire()) {
error = -EBUSY;
swsusp_close();
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();
goto Finish;
}
/**
* software_resume_initcall - 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 __init software_resume_initcall(void)
{
/*
* If the user said "noresume".. bail out early.
*/
if (noresume || !hibernation_available())
return 0;
if (!swsusp_resume_device) {
int error = find_resume_device();
if (error)
return error;
}
return software_resume();
}
late_initcall_sync(software_resume_initcall);
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)
{
ssize_t count = 0;
int i;
if (!hibernation_available())
return sysfs_emit(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)
count += sysfs_emit_at(buf, count, "[%s] ", hibernation_modes[i]);
else
count += sysfs_emit_at(buf, count, "%s ", hibernation_modes[i]);
}
/* Convert the last space to a newline if needed. */
if (count > 0)
buf[count - 1] = '\n';
return count;
}
static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
const char *buf, size_t n)
{
int mode = HIBERNATION_INVALID;
unsigned int sleep_flags;
int error = 0;
int len;
char *p;
int i;
if (!hibernation_available())
return -EPERM;
p = memchr(buf, '\n', n);
len = p ? p - buf : n;
sleep_flags = 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(sleep_flags);
return error ? error : n;
}
power_attr(disk);
static ssize_t resume_show(struct kobject *kobj, struct kobj_attribute *attr,
char *buf)
{
return sysfs_emit(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 sleep_flags;
int len = n;
char *name;
dev_t dev;
int error;
if (!hibernation_available())
return n;
if (len && buf[len-1] == '\n')
len--;
name = kstrndup(buf, len, GFP_KERNEL);
if (!name)
return -ENOMEM;
error = lookup_bdev(name, &dev);
if (error) {
unsigned maj, min, offset;
char *p, dummy;
error = 0;
if (sscanf(name, "%u:%u%c", &maj, &min, &dummy) == 2 ||
sscanf(name, "%u:%u:%u:%c", &maj, &min, &offset,
&dummy) == 3) {
dev = MKDEV(maj, min);
if (maj != MAJOR(dev) || min != MINOR(dev))
error = -EINVAL;
} else {
dev = new_decode_dev(simple_strtoul(name, &p, 16));
if (*p)
error = -EINVAL;
}
}
kfree(name);
if (error)
return error;
sleep_flags = lock_system_sleep();
swsusp_resume_device = dev;
unlock_system_sleep(sleep_flags);
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 sysfs_emit(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 sysfs_emit(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 sysfs_emit(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;
strscpy(resume_file, str);
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)
pr_warn("resumedelay: bad option string '%s'\n", str);
return 1;
}
static int __init nohibernate_setup(char *str)
{
noresume = 1;
nohibernate = 1;
return 1;
}
static const char * const comp_alg_enabled[] = {
#if IS_ENABLED(CONFIG_CRYPTO_LZO)
COMPRESSION_ALGO_LZO,
#endif
#if IS_ENABLED(CONFIG_CRYPTO_LZ4)
COMPRESSION_ALGO_LZ4,
#endif
};
static int hibernate_compressor_param_set(const char *compressor,
const struct kernel_param *kp)
{
unsigned int sleep_flags;
int index, ret;
sleep_flags = lock_system_sleep();
index = sysfs_match_string(comp_alg_enabled, compressor);
if (index >= 0) {
ret = param_set_copystring(comp_alg_enabled[index], kp);
if (!ret)
strscpy(hib_comp_algo, comp_alg_enabled[index],
sizeof(hib_comp_algo));
} else {
ret = index;
}
unlock_system_sleep(sleep_flags);
if (ret)
pr_debug("Cannot set specified compressor %s\n",
compressor);
return ret;
}
static const struct kernel_param_ops hibernate_compressor_param_ops = {
.set = hibernate_compressor_param_set,
.get = param_get_string,
};
static struct kparam_string hibernate_compressor_param_string = {
.maxlen = sizeof(hibernate_compressor),
.string = hibernate_compressor,
};
module_param_cb(compressor, &hibernate_compressor_param_ops,
&hibernate_compressor_param_string, 0644);
MODULE_PARM_DESC(compressor,
"Compression algorithm to be used with hibernation");
__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);
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