1 files changed, 431 insertions, 0 deletions
diff --git a/kernel/power/disk.c b/kernel/power/disk.c
new file mode 100644
index 00000000000..02b6764034d
--- /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);