kernel_optimize_test/kernel/power/disk.c
Rafael J. Wysocki 74dfd666de swsusp: do not use page flags
Make swsusp use memory bitmaps instead of page flags for marking 'nosave' and
free pages.  This allows us to 'recycle' two page flags that can be used for
other purposes.  Also, the memory needed to store the bitmaps is allocated
when necessary (ie.  before the suspend) and freed after the resume which is
more reasonable.

The patch is designed to minimize the amount of changes and there are some
nice simplifications and optimizations possible on top of it.  I am going to
implement them separately in the future.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-05-07 12:12:59 -07:00

490 lines
9.6 KiB
C

/*
* 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/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 "power.h"
static int noresume = 0;
char resume_file[256] = CONFIG_PM_STD_PARTITION;
dev_t swsusp_resume_device;
sector_t swsusp_resume_block;
/**
* platform_prepare - prepare the machine for hibernation using the
* platform driver if so configured and return an error code if it fails
*/
static inline int platform_prepare(void)
{
int error = 0;
switch (pm_disk_mode) {
case PM_DISK_TEST:
case PM_DISK_TESTPROC:
case PM_DISK_SHUTDOWN:
case PM_DISK_REBOOT:
break;
default:
if (pm_ops && pm_ops->prepare)
error = pm_ops->prepare(PM_SUSPEND_DISK);
}
return error;
}
/**
* power_down - Shut machine down for hibernate.
*
* Use the platform driver, if configured so; otherwise try
* to power off or reboot.
*/
static void power_down(void)
{
switch (pm_disk_mode) {
case PM_DISK_TEST:
case PM_DISK_TESTPROC:
break;
case PM_DISK_SHUTDOWN:
kernel_power_off();
break;
case PM_DISK_REBOOT:
kernel_restart(NULL);
break;
default:
if (pm_ops && pm_ops->enter) {
kernel_shutdown_prepare(SYSTEM_SUSPEND_DISK);
pm_ops->enter(PM_SUSPEND_DISK);
break;
}
}
kernel_halt();
/*
* Valid image is on the disk, if we continue we risk serious data
* corruption after resume.
*/
printk(KERN_CRIT "Please power me down manually\n");
while(1);
}
static inline void platform_finish(void)
{
switch (pm_disk_mode) {
case PM_DISK_TEST:
case PM_DISK_TESTPROC:
case PM_DISK_SHUTDOWN:
case PM_DISK_REBOOT:
break;
default:
if (pm_ops && pm_ops->finish)
pm_ops->finish(PM_SUSPEND_DISK);
}
}
static void unprepare_processes(void)
{
thaw_processes();
pm_restore_console();
}
static int prepare_processes(void)
{
int error = 0;
pm_prepare_console();
if (freeze_processes()) {
error = -EBUSY;
unprepare_processes();
}
return error;
}
/**
* pm_suspend_disk - The granpappy of hibernation power management.
*
* If not, then call swsusp to do its thing, then figure out how
* to power down the system.
*/
int pm_suspend_disk(void)
{
int error;
error = prepare_processes();
if (error)
return error;
if (pm_disk_mode == PM_DISK_TESTPROC) {
printk("swsusp debug: Waiting for 5 seconds.\n");
mdelay(5000);
goto Thaw;
}
/* Allocate memory management structures */
error = create_basic_memory_bitmaps();
if (error)
goto Thaw;
/* Free memory before shutting down devices. */
error = swsusp_shrink_memory();
if (error)
goto Finish;
error = platform_prepare();
if (error)
goto Finish;
suspend_console();
error = device_suspend(PMSG_FREEZE);
if (error) {
printk(KERN_ERR "PM: Some devices failed to suspend\n");
goto Resume_devices;
}
error = disable_nonboot_cpus();
if (error)
goto Enable_cpus;
if (pm_disk_mode == PM_DISK_TEST) {
printk("swsusp debug: Waiting for 5 seconds.\n");
mdelay(5000);
goto Enable_cpus;
}
pr_debug("PM: snapshotting memory.\n");
in_suspend = 1;
error = swsusp_suspend();
if (error)
goto Enable_cpus;
if (in_suspend) {
enable_nonboot_cpus();
platform_finish();
device_resume();
resume_console();
pr_debug("PM: writing image.\n");
error = swsusp_write();
if (!error)
power_down();
else {
swsusp_free();
goto Finish;
}
} else {
pr_debug("PM: Image restored successfully.\n");
}
swsusp_free();
Enable_cpus:
enable_nonboot_cpus();
Resume_devices:
platform_finish();
device_resume();
resume_console();
Finish:
free_basic_memory_bitmaps();
Thaw:
unprepare_processes();
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 pm_suspend_disk() ) if everything goes well.
* Otherwise, we fail gracefully and return to the normally
* scheduled program.
*
*/
static int software_resume(void)
{
int error;
mutex_lock(&pm_mutex);
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("swsusp: Resume From Partition %s\n", resume_file);
} else {
pr_debug("swsusp: 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 swsusp image.\n");
error = swsusp_check();
if (error)
goto Unlock;
error = create_basic_memory_bitmaps();
if (error)
goto Unlock;
pr_debug("PM: Preparing processes for restore.\n");
error = prepare_processes();
if (error) {
swsusp_close();
goto Done;
}
pr_debug("PM: Reading swsusp image.\n");
error = swsusp_read();
if (error) {
swsusp_free();
goto Thaw;
}
pr_debug("PM: Preparing devices for restore.\n");
suspend_console();
error = device_suspend(PMSG_PRETHAW);
if (error)
goto Free;
error = disable_nonboot_cpus();
if (!error)
swsusp_resume();
enable_nonboot_cpus();
Free:
swsusp_free();
device_resume();
resume_console();
Thaw:
printk(KERN_ERR "PM: Restore failed, recovering.\n");
unprepare_processes();
Done:
free_basic_memory_bitmaps();
/* For success case, the suspend path will release the lock */
Unlock:
mutex_unlock(&pm_mutex);
pr_debug("PM: Resume from disk failed.\n");
return 0;
}
late_initcall(software_resume);
static const char * const pm_disk_modes[] = {
[PM_DISK_PLATFORM] = "platform",
[PM_DISK_SHUTDOWN] = "shutdown",
[PM_DISK_REBOOT] = "reboot",
[PM_DISK_TEST] = "test",
[PM_DISK_TESTPROC] = "testproc",
};
/**
* disk - Control suspend-to-disk 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 pm_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 in pm_ops). However, the user may choose 'shutdown' or 'reboot'
* as alternatives, as well as the test modes 'test' and '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 from pm_ops->pm_disk_mode).
*/
static ssize_t disk_show(struct kset *kset, char *buf)
{
return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
}
static ssize_t disk_store(struct kset *kset, const char *buf, size_t n)
{
int error = 0;
int i;
int len;
char *p;
suspend_disk_method_t mode = 0;
p = memchr(buf, '\n', n);
len = p ? p - buf : n;
mutex_lock(&pm_mutex);
for (i = PM_DISK_PLATFORM; i < PM_DISK_MAX; i++) {
if (!strncmp(buf, pm_disk_modes[i], len)) {
mode = i;
break;
}
}
if (mode) {
switch (mode) {
case PM_DISK_SHUTDOWN:
case PM_DISK_REBOOT:
case PM_DISK_TEST:
case PM_DISK_TESTPROC:
pm_disk_mode = mode;
break;
default:
if (pm_ops && pm_ops->enter &&
(mode == pm_ops->pm_disk_mode))
pm_disk_mode = mode;
else
error = -EINVAL;
}
} else {
error = -EINVAL;
}
pr_debug("PM: suspend-to-disk mode set to '%s'\n",
pm_disk_modes[mode]);
mutex_unlock(&pm_mutex);
return error ? error : n;
}
power_attr(disk);
static ssize_t resume_show(struct kset *kset, char *buf)
{
return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
MINOR(swsusp_resume_device));
}
static ssize_t resume_store(struct kset *kset, 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("Attempting manual resume\n");
noresume = 0;
software_resume();
ret = n;
out:
return ret;
}
power_attr(resume);
static ssize_t image_size_show(struct kset *kset, char *buf)
{
return sprintf(buf, "%lu\n", image_size);
}
static ssize_t image_size_store(struct kset *kset, 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_subsys.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);