/*
* kernel/power/disk.c - Suspend-to-disk support.
*
* Copyright (c) 2003 Patrick Mochel
* Copyright (c) 2003 Open Source Development Lab
* Copyright (c) 2004 Pavel Machek <pavel@suse.cz>
*
* This file is released under the GPLv2.
*
*/
#include <linux/suspend.h>
#include <linux/syscalls.h>
#include <linux/reboot.h>
#include <linux/string.h>
#include <linux/device.h>
#include <linux/kmod.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/ftrace.h>
#include "power.h"
static int noresume = 0;
static char resume_file[256] = CONFIG_PM_STD_PARTITION;
dev_t swsusp_resume_device;
sector_t swsusp_resume_block;
enum {
HIBERNATION_INVALID,
HIBERNATION_PLATFORM,
HIBERNATION_TEST,
HIBERNATION_TESTPROC,
HIBERNATION_SHUTDOWN,
HIBERNATION_REBOOT,
/* keep last */
__HIBERNATION_AFTER_LAST
};
#define HIBERNATION_MAX (__HIBERNATION_AFTER_LAST-1)
#define HIBERNATION_FIRST (HIBERNATION_INVALID + 1)
static int hibernation_mode = HIBERNATION_SHUTDOWN;
static struct platform_hibernation_ops *hibernation_ops;
/**
* hibernation_set_ops - set the global hibernate operations
* @ops: the hibernation operations to use in subsequent hibernation transitions
*/
void hibernation_set_ops(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)) {
WARN_ON(1);
return;
}
mutex_lock(&pm_mutex);
hibernation_ops = ops;
if (ops)
hibernation_mode = HIBERNATION_PLATFORM;
else if (hibernation_mode == HIBERNATION_PLATFORM)
hibernation_mode = HIBERNATION_SHUTDOWN;
mutex_unlock(&pm_mutex);
}
#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_testmode(int mode)
{
if (hibernation_mode == mode) {
hibernation_debug_sleep();
return 1;
}
return 0;
}
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_testmode(int mode) { return 0; }
static int hibernation_test(int level) { return 0; }
#endif /* !CONFIG_PM_DEBUG */
/**
* platform_begin - tell the platform driver that we're starting
* hibernation
*/
static int platform_begin(int platform_mode)
{
return (platform_mode && hibernation_ops) ?
hibernation_ops->begin() : 0;
}
/**
* platform_end - tell the platform driver that we've entered the
* working state
*/
static void platform_end(int platform_mode)
{
if (platform_mode && hibernation_ops)
hibernation_ops->end();
}
/**
* platform_pre_snapshot - prepare the machine for hibernation using the
* platform driver if so configured and return an error code if it fails
*/
static int platform_pre_snapshot(int platform_mode)
{
return (platform_mode && hibernation_ops) ?
hibernation_ops->pre_snapshot() : 0;
}
/**
* platform_leave - prepare the machine for switching to the normal mode
* of operation using the platform driver (called with interrupts disabled)
*/
static void platform_leave(int platform_mode)
{
if (platform_mode && hibernation_ops)
hibernation_ops->leave();
}
/**
* platform_finish - switch the machine to the normal mode of operation
* using the platform driver (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 the platform for the restoration 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 the platform 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 the platform from a failure to suspend
* devices.
*/
static void platform_recover(int platform_mode)
{
if (platform_mode && hibernation_ops && hibernation_ops->recover)
hibernation_ops->recover();
}
/**
* create_image - freeze devices that need to be frozen with interrupts
* off, create the hibernation image and thaw those devices. Control
* reappears in this routine after a restore.
*/
static int create_image(int platform_mode)
{
int error;
error = arch_prepare_suspend();
if (error)
return error;
device_pm_lock();
local_irq_disable();
/* At this point, device_suspend() has been called, but *not*
* device_power_down(). We *must* call device_power_down() now.
* Otherwise, drivers for some devices (e.g. interrupt controllers)
* become desynchronized with the actual state of the hardware
* at resume time, and evil weirdness ensues.
*/
error = device_power_down(PMSG_FREEZE);
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down, "
"aborting hibernation\n");
goto Enable_irqs;
}
if (hibernation_test(TEST_CORE))
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)
platform_leave(platform_mode);
Power_up:
/* NOTE: device_power_up() is just a resume() for devices
* that suspended with irqs off ... no overall powerup.
*/
device_power_up(in_suspend ?
(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
Enable_irqs:
local_irq_enable();
device_pm_unlock();
return error;
}
/**
* hibernation_snapshot - quiesce devices and create the hibernation
* snapshot image.
* @platform_mode - if set, use the platform driver, if available, to
* prepare the platform frimware for the power transition.
*
* Must be called with pm_mutex held
*/
int hibernation_snapshot(int platform_mode)
{
int error, ftrace_save;
/* Free memory before shutting down devices. */
error = swsusp_shrink_memory();
if (error)
return error;
error = platform_begin(platform_mode);
if (error)
goto Close;
suspend_console();
ftrace_save = __ftrace_enabled_save();
error = device_suspend(PMSG_FREEZE);
if (error)
goto Recover_platform;
if (hibernation_test(TEST_DEVICES))
goto Recover_platform;
error = platform_pre_snapshot(platform_mode);
if (error || hibernation_test(TEST_PLATFORM))
goto Finish;
error = disable_nonboot_cpus();
if (!error) {
if (hibernation_test(TEST_CPUS))
goto Enable_cpus;
if (hibernation_testmode(HIBERNATION_TEST))
goto Enable_cpus;
error = create_image(platform_mode);
/* Control returns here after successful restore */
}
Enable_cpus:
enable_nonboot_cpus();
Finish:
platform_finish(platform_mode);
Resume_devices:
device_resume(in_suspend ?
(error ? PMSG_RECOVER : PMSG_THAW) : PMSG_RESTORE);
__ftrace_enabled_restore(ftrace_save);
resume_console();
Close:
platform_end(platform_mode);
return error;
Recover_platform:
platform_recover(platform_mode);
goto Resume_devices;
}
/**
* resume_target_kernel - prepare devices that need to be suspended with
* interrupts off, 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(void)
{
int error;
device_pm_lock();
local_irq_disable();
error = device_power_down(PMSG_QUIESCE);
if (error) {
printk(KERN_ERR "PM: Some devices failed to power down, "
"aborting resume\n");
goto Enable_irqs;
}
/* We'll ignore saved state, but this gets preempt count (etc) right */
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 place where
* swsusp_arch_suspend() was called
*/
BUG_ON(!error);
/* This call to restore_highmem() undos 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();
device_power_up(PMSG_RECOVER);
Enable_irqs:
local_irq_enable();
device_pm_unlock();
return error;
}
/**
* hibernation_restore - quiesce devices and restore the hibernation
* snapshot image. If successful, control returns in hibernation_snaphot()
* @platform_mode - if set, use the platform driver, if available, to
* prepare the platform frimware for the transition.
*
* Must be called with pm_mutex held
*/
int hibernation_restore(int platform_mode)
{
int error, ftrace_save;
pm_prepare_console();
suspend_console();
ftrace_save = __ftrace_enabled_save();
error = device_suspend(PMSG_QUIESCE);
if (error)
goto Finish;
error = platform_pre_restore(platform_mode);
if (!error) {
error = disable_nonboot_cpus();
if (!error)
error = resume_target_kernel();
enable_nonboot_cpus();
}
platform_restore_cleanup(platform_mode);
device_resume(PMSG_RECOVER);
Finish:
__ftrace_enabled_restore(ftrace_save);
resume_console();
pm_restore_console();
return error;
}
/**
* hibernation_platform_enter - enter the hibernation state using the
* platform driver (if available)
*/
int hibernation_platform_enter(void)
{
int error, ftrace_save;
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;
suspend_console();
ftrace_save = __ftrace_enabled_save();
error = device_suspend(PMSG_HIBERNATE);
if (error) {
if (hibernation_ops->recover)
hibernation_ops->recover();
goto Resume_devices;
}
error = hibernation_ops->prepare();
if (error)
goto Resume_devices;
error = disable_nonboot_cpus();
if (error)
goto Finish;
device_pm_lock();
local_irq_disable();
error = device_power_down(PMSG_HIBERNATE);
if (!error) {
hibernation_ops->enter();
/* We should never get here */
while (1);
}
local_irq_enable();
device_pm_unlock();
/*
* We don't need to reenable the nonboot CPUs or resume consoles, since
* the system is going to be halted anyway.
*/
Finish:
hibernation_ops->finish();
Resume_devices:
device_resume(PMSG_RESTORE);
__ftrace_enabled_restore(ftrace_save);
resume_console();
Close:
hibernation_ops->end();
return error;
}
/**
* power_down - Shut the machine down for hibernation.
*
* Use the platform driver, if configured so; otherwise try
* to power off or reboot.
*/
static void power_down(void)
{
switch (hibernation_mode) {
case HIBERNATION_TEST:
case HIBERNATION_TESTPROC:
break;
case HIBERNATION_REBOOT:
kernel_restart(NULL);
break;
case HIBERNATION_PLATFORM:
hibernation_platform_enter();
case HIBERNATION_SHUTDOWN:
kernel_power_off();
break;
}
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);
}
static int prepare_processes(void)
{
int error = 0;
if (freeze_processes()) {
error = -EBUSY;
thaw_processes();
}
return error;
}
/**
* hibernate - The granpappy of the built-in hibernation management
*/
int hibernate(void)
{
int error;
mutex_lock(&pm_mutex);
/* 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;
error = usermodehelper_disable();
if (error)
goto Exit;
/* Allocate memory management structures */
error = create_basic_memory_bitmaps();
if (error)
goto Exit;
printk(KERN_INFO "PM: Syncing filesystems ... ");
sys_sync();
printk("done.\n");
error = prepare_processes();
if (error)
goto Finish;
if (hibernation_test(TEST_FREEZER))
goto Thaw;
if (hibernation_testmode(HIBERNATION_TESTPROC))
goto Thaw;
error = hibernation_snapshot(hibernation_mode == HIBERNATION_PLATFORM);
if (in_suspend && !error) {
unsigned int flags = 0;
if (hibernation_mode == HIBERNATION_PLATFORM)
flags |= SF_PLATFORM_MODE;
pr_debug("PM: writing image.\n");
error = swsusp_write(flags);
swsusp_free();
if (!error)
power_down();
} else {
pr_debug("PM: Image restored successfully.\n");
swsusp_free();
}
Thaw:
thaw_processes();
Finish:
free_basic_memory_bitmaps();
usermodehelper_enable();
Exit:
pm_notifier_call_chain(PM_POST_HIBERNATION);
pm_restore_console();
atomic_inc(&snapshot_device_available);
Unlock:
mutex_unlock(&pm_mutex);
return error;
}
/**
* software_resume - Resume from a saved image.
*
* Called as a late_initcall (so all devices are discovered and
* initialized), we call swsusp to see if we have a saved image or not.
* If so, we quiesce devices, the restore the saved image. We will
* return above (in hibernate() ) if everything goes well.
* Otherwise, we fail gracefully and return to the normally
* scheduled program.
*
*/
static int software_resume(void)
{
int error;
unsigned int flags;
/*
* 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) {
if (!strlen(resume_file)) {
mutex_unlock(&pm_mutex);
return -ENOENT;
}
swsusp_resume_device = name_to_dev_t(resume_file);
pr_debug("PM: Resume from partition %s\n", resume_file);
} else {
pr_debug("PM: Resume from partition %d:%d\n",
MAJOR(swsusp_resume_device),
MINOR(swsusp_resume_device));
}
if (noresume) {
/**
* FIXME: If noresume is specified, we need to find the
* partition and reset it back to normal swap space.
*/
mutex_unlock(&pm_mutex);
return 0;
}
pr_debug("PM: Checking 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;
goto Unlock;
}
pm_prepare_console();
error = pm_notifier_call_chain(PM_RESTORE_PREPARE);
if (error)
goto Finish;
error = usermodehelper_disable();
if (error)
goto Finish;
error = create_basic_memory_bitmaps();
if (error)
goto Finish;
pr_debug("PM: Preparing processes for restore.\n");
error = prepare_processes();
if (error) {
swsusp_close(FMODE_READ);
goto Done;
}
pr_debug("PM: Reading hibernation image.\n");
error = swsusp_read(&flags);
if (!error)
hibernation_restore(flags & SF_PLATFORM_MODE);
printk(KERN_ERR "PM: Restore failed, recovering.\n");
swsusp_free();
thaw_processes();
Done:
free_basic_memory_bitmaps();
usermodehelper_enable();
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: Resume from disk failed.\n");
return error;
}
late_initcall(software_resume);
static const char * const hibernation_modes[] = {
[HIBERNATION_PLATFORM] = "platform",
[HIBERNATION_SHUTDOWN] = "shutdown",
[HIBERNATION_REBOOT] = "reboot",
[HIBERNATION_TEST] = "test",
[HIBERNATION_TESTPROC] = "testproc",
};
/**
* disk - Control hibernation mode
*
* Suspend-to-disk can be handled in several ways. We have a few options
* for putting the system to sleep - using the platform driver (e.g. ACPI
* or other hibernation_ops), powering off the system or rebooting the
* system (for testing) as well as the two test modes.
*
* The system can support 'platform', and that is known a priori (and
* encoded by the presence of hibernation_ops). However, the user may
* choose 'shutdown' or 'reboot' as alternatives, as well as one fo the
* test modes, 'test' or 'testproc'.
*
* show() will display what the mode is currently set to.
* store() will accept one of
*
* 'platform'
* 'shutdown'
* 'reboot'
* 'test'
* 'testproc'
*
* It will only change to 'platform' if the system
* supports it (as determined by having hibernation_ops).
*/
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:
case HIBERNATION_TEST:
case HIBERNATION_TESTPROC:
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;
mutex_lock(&pm_mutex);
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:
case HIBERNATION_TEST:
case HIBERNATION_TESTPROC:
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]);
mutex_unlock(&pm_mutex);
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;
mutex_lock(&pm_mutex);
swsusp_resume_device = res;
mutex_unlock(&pm_mutex);
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 struct attribute * g[] = {
&disk_attr.attr,
&resume_attr.attr,
&image_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 noresume_setup(char *str)
{
noresume = 1;
return 1;
}
__setup("noresume", noresume_setup);
__setup("resume_offset=", resume_offset_setup);
__setup("resume=", resume_setup);
