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);