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-rw-r--r--kernel/power/disk.c431
1 files changed, 431 insertions, 0 deletions
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
new file mode 100644
index 000000000000..02b6764034dc
--- /dev/null
+++ b/kernel/power/disk.c
@@ -0,0 +1,431 @@
+/*
+ * 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 "power.h"
+
+
+extern suspend_disk_method_t pm_disk_mode;
+extern struct pm_ops * pm_ops;
+
+extern int swsusp_suspend(void);
+extern int swsusp_write(void);
+extern int swsusp_check(void);
+extern int swsusp_read(void);
+extern void swsusp_close(void);
+extern int swsusp_resume(void);
+extern int swsusp_free(void);
+
+
+static int noresume = 0;
+char resume_file[256] = CONFIG_PM_STD_PARTITION;
+dev_t swsusp_resume_device;
+
+/**
+ * power_down - Shut machine down for hibernate.
+ * @mode: Suspend-to-disk mode
+ *
+ * Use the platform driver, if configured so, and return gracefully if it
+ * fails.
+ * Otherwise, try to power off and reboot. If they fail, halt the machine,
+ * there ain't no turning back.
+ */
+
+static void power_down(suspend_disk_method_t mode)
+{
+ unsigned long flags;
+ int error = 0;
+
+ local_irq_save(flags);
+ switch(mode) {
+ case PM_DISK_PLATFORM:
+ device_shutdown();
+ error = pm_ops->enter(PM_SUSPEND_DISK);
+ break;
+ case PM_DISK_SHUTDOWN:
+ printk("Powering off system\n");
+ device_shutdown();
+ machine_power_off();
+ break;
+ case PM_DISK_REBOOT:
+ device_shutdown();
+ machine_restart(NULL);
+ break;
+ }
+ machine_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 int in_suspend __nosavedata = 0;
+
+
+/**
+ * free_some_memory - Try to free as much memory as possible
+ *
+ * ... but do not OOM-kill anyone
+ *
+ * Notice: all userland should be stopped at this point, or
+ * livelock is possible.
+ */
+
+static void free_some_memory(void)
+{
+ unsigned int i = 0;
+ unsigned int tmp;
+ unsigned long pages = 0;
+ char *p = "-\\|/";
+
+ printk("Freeing memory... ");
+ while ((tmp = shrink_all_memory(10000))) {
+ pages += tmp;
+ printk("\b%c", p[i]);
+ i++;
+ if (i > 3)
+ i = 0;
+ }
+ printk("\bdone (%li pages freed)\n", pages);
+}
+
+
+static inline void platform_finish(void)
+{
+ if (pm_disk_mode == PM_DISK_PLATFORM) {
+ if (pm_ops && pm_ops->finish)
+ pm_ops->finish(PM_SUSPEND_DISK);
+ }
+}
+
+static void finish(void)
+{
+ device_resume();
+ platform_finish();
+ enable_nonboot_cpus();
+ thaw_processes();
+ pm_restore_console();
+}
+
+
+static int prepare_processes(void)
+{
+ int error;
+
+ pm_prepare_console();
+
+ sys_sync();
+
+ if (freeze_processes()) {
+ error = -EBUSY;
+ return error;
+ }
+
+ if (pm_disk_mode == PM_DISK_PLATFORM) {
+ if (pm_ops && pm_ops->prepare) {
+ if ((error = pm_ops->prepare(PM_SUSPEND_DISK)))
+ return error;
+ }
+ }
+
+ /* Free memory before shutting down devices. */
+ free_some_memory();
+
+ return 0;
+}
+
+static void unprepare_processes(void)
+{
+ enable_nonboot_cpus();
+ thaw_processes();
+ pm_restore_console();
+}
+
+static int prepare_devices(void)
+{
+ int error;
+
+ disable_nonboot_cpus();
+ if ((error = device_suspend(PMSG_FREEZE))) {
+ printk("Some devices failed to suspend\n");
+ platform_finish();
+ enable_nonboot_cpus();
+ return error;
+ }
+
+ return 0;
+}
+
+/**
+ * pm_suspend_disk - The granpappy of power management.
+ *
+ * If we're going through the firmware, then get it over with quickly.
+ *
+ * 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) {
+ error = prepare_devices();
+ }
+
+ if (error) {
+ unprepare_processes();
+ return error;
+ }
+
+ pr_debug("PM: Attempting to suspend to disk.\n");
+ if (pm_disk_mode == PM_DISK_FIRMWARE)
+ return pm_ops->enter(PM_SUSPEND_DISK);
+
+ pr_debug("PM: snapshotting memory.\n");
+ in_suspend = 1;
+ if ((error = swsusp_suspend()))
+ goto Done;
+
+ if (in_suspend) {
+ pr_debug("PM: writing image.\n");
+ error = swsusp_write();
+ if (!error)
+ power_down(pm_disk_mode);
+ } else
+ pr_debug("PM: Image restored successfully.\n");
+ swsusp_free();
+ Done:
+ finish();
+ 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;
+
+ if (noresume) {
+ /**
+ * FIXME: If noresume is specified, we need to find the partition
+ * and reset it back to normal swap space.
+ */
+ return 0;
+ }
+
+ pr_debug("PM: Checking swsusp image.\n");
+
+ if ((error = swsusp_check()))
+ goto Done;
+
+ pr_debug("PM: Preparing processes for restore.\n");
+
+ if ((error = prepare_processes())) {
+ swsusp_close();
+ goto Cleanup;
+ }
+
+ pr_debug("PM: Reading swsusp image.\n");
+
+ if ((error = swsusp_read()))
+ goto Cleanup;
+
+ pr_debug("PM: Preparing devices for restore.\n");
+
+ if ((error = prepare_devices()))
+ goto Free;
+
+ mb();
+
+ pr_debug("PM: Restoring saved image.\n");
+ swsusp_resume();
+ pr_debug("PM: Restore failed, recovering.n");
+ finish();
+ Free:
+ swsusp_free();
+ Cleanup:
+ unprepare_processes();
+ Done:
+ pr_debug("PM: Resume from disk failed.\n");
+ return 0;
+}
+
+late_initcall(software_resume);
+
+
+static char * pm_disk_modes[] = {
+ [PM_DISK_FIRMWARE] = "firmware",
+ [PM_DISK_PLATFORM] = "platform",
+ [PM_DISK_SHUTDOWN] = "shutdown",
+ [PM_DISK_REBOOT] = "reboot",
+};
+
+/**
+ * disk - Control suspend-to-disk mode
+ *
+ * Suspend-to-disk can be handled in several ways. The greatest
+ * distinction is who writes memory to disk - the firmware or the OS.
+ * If the firmware does it, we assume that it also handles suspending
+ * the system.
+ * If the OS does it, then we have three options for putting the system
+ * to sleep - using the platform driver (e.g. ACPI or other PM registers),
+ * powering off the system or rebooting the system (for testing).
+ *
+ * The system will support either 'firmware' or 'platform', and that is
+ * known a priori (and encoded in pm_ops). But, the user may choose
+ * 'shutdown' or 'reboot' as alternatives.
+ *
+ * show() will display what the mode is currently set to.
+ * store() will accept one of
+ *
+ * 'firmware'
+ * 'platform'
+ * 'shutdown'
+ * 'reboot'
+ *
+ * It will only change to 'firmware' or 'platform' if the system
+ * supports it (as determined from pm_ops->pm_disk_mode).
+ */
+
+static ssize_t disk_show(struct subsystem * subsys, char * buf)
+{
+ return sprintf(buf, "%s\n", pm_disk_modes[pm_disk_mode]);
+}
+
+
+static ssize_t disk_store(struct subsystem * s, 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;
+
+ down(&pm_sem);
+ for (i = PM_DISK_FIRMWARE; i < PM_DISK_MAX; i++) {
+ if (!strncmp(buf, pm_disk_modes[i], len)) {
+ mode = i;
+ break;
+ }
+ }
+ if (mode) {
+ if (mode == PM_DISK_SHUTDOWN || mode == PM_DISK_REBOOT)
+ pm_disk_mode = mode;
+ else {
+ 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]);
+ up(&pm_sem);
+ return error ? error : n;
+}
+
+power_attr(disk);
+
+static ssize_t resume_show(struct subsystem * subsys, char *buf)
+{
+ return sprintf(buf,"%d:%d\n", MAJOR(swsusp_resume_device),
+ MINOR(swsusp_resume_device));
+}
+
+static ssize_t resume_store(struct subsystem * subsys, const char * buf, size_t n)
+{
+ int len;
+ char *p;
+ unsigned int maj, min;
+ int error = -EINVAL;
+ dev_t res;
+
+ p = memchr(buf, '\n', n);
+ len = p ? p - buf : n;
+
+ if (sscanf(buf, "%u:%u", &maj, &min) == 2) {
+ res = MKDEV(maj,min);
+ if (maj == MAJOR(res) && min == MINOR(res)) {
+ swsusp_resume_device = res;
+ printk("Attempting manual resume\n");
+ noresume = 0;
+ software_resume();
+ }
+ }
+
+ return error >= 0 ? n : error;
+}
+
+power_attr(resume);
+
+static struct attribute * g[] = {
+ &disk_attr.attr,
+ &resume_attr.attr,
+ NULL,
+};
+
+
+static struct attribute_group attr_group = {
+ .attrs = g,
+};
+
+
+static int __init pm_disk_init(void)
+{
+ return sysfs_create_group(&power_subsys.kset.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 noresume_setup(char *str)
+{
+ noresume = 1;
+ return 1;
+}
+
+__setup("noresume", noresume_setup);
+__setup("resume=", resume_setup);