1 files changed, 56 insertions, 13 deletions

diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index c8b7446..d4feda0 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -30,12 +30,38 @@
 #include "power.h"
 
 const char *const pm_states[PM_SUSPEND_MAX] = {
+	[PM_SUSPEND_FREEZE]	= "freeze",
 	[PM_SUSPEND_STANDBY]	= "standby",
 	[PM_SUSPEND_MEM]	= "mem",
 };
 
 static const struct platform_suspend_ops *suspend_ops;
 
+static bool need_suspend_ops(suspend_state_t state)
+{
+	return !!(state > PM_SUSPEND_FREEZE);
+}
+
+static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
+static bool suspend_freeze_wake;
+
+static void freeze_begin(void)
+{
+	suspend_freeze_wake = false;
+}
+
+static void freeze_enter(void)
+{
+	wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
+}
+
+void freeze_wake(void)
+{
+	suspend_freeze_wake = true;
+	wake_up(&suspend_freeze_wait_head);
+}
+EXPORT_SYMBOL_GPL(freeze_wake);
+
 /**
  * suspend_set_ops - Set the global suspend method table.
  * @ops: Suspend operations to use.
@@ -50,8 +76,11 @@ EXPORT_SYMBOL_GPL(suspend_set_ops);
 
 bool valid_state(suspend_state_t state)
 {
+	if (state == PM_SUSPEND_FREEZE)
+		return true;
 	/*
-	 * All states need lowlevel support and need to be valid to the lowlevel
+	 * PM_SUSPEND_STANDBY and PM_SUSPEND_MEMORY states need lowlevel
+	 * support and need to be valid to the lowlevel
 	 * implementation, no valid callback implies that none are valid.
 	 */
 	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state);
@@ -89,11 +118,11 @@ static int suspend_test(int level)
  * hibernation).  Run suspend notifiers, allocate the "suspend" console and
  * freeze processes.
  */
-static int suspend_prepare(void)
+static int suspend_prepare(suspend_state_t state)
 {
 	int error;
 
-	if (!suspend_ops || !suspend_ops->enter)
+	if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
 		return -EPERM;
 
 	pm_prepare_console();
@@ -137,7 +166,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 {
 	int error;
 
-	if (suspend_ops->prepare) {
+	if (need_suspend_ops(state) && suspend_ops->prepare) {
 		error = suspend_ops->prepare();
 		if (error)
 			goto Platform_finish;
@@ -149,12 +178,23 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 		goto Platform_finish;
 	}
 
-	if (suspend_ops->prepare_late) {
+	if (need_suspend_ops(state) && suspend_ops->prepare_late) {
 		error = suspend_ops->prepare_late();
 		if (error)
 			goto Platform_wake;
 	}
 
+	/*
+	 * PM_SUSPEND_FREEZE equals
+	 * frozen processes + suspended devices + idle processors.
+	 * Thus we should invoke freeze_enter() soon after
+	 * all the devices are suspended.
+	 */
+	if (state == PM_SUSPEND_FREEZE) {
+		freeze_enter();
+		goto Platform_wake;
+	}
+
 	if (suspend_test(TEST_PLATFORM))
 		goto Platform_wake;
 
@@ -182,13 +222,13 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 	enable_nonboot_cpus();
 
  Platform_wake:
-	if (suspend_ops->wake)
+	if (need_suspend_ops(state) && suspend_ops->wake)
 		suspend_ops->wake();
 
 	dpm_resume_start(PMSG_RESUME);
 
  Platform_finish:
-	if (suspend_ops->finish)
+	if (need_suspend_ops(state) && suspend_ops->finish)
 		suspend_ops->finish();
 
 	return error;
@@ -203,11 +243,11 @@ int suspend_devices_and_enter(suspend_state_t state)
 	int error;
 	bool wakeup = false;
 
-	if (!suspend_ops)
+	if (need_suspend_ops(state) && !suspend_ops)
 		return -ENOSYS;
 
 	trace_machine_suspend(state);
-	if (suspend_ops->begin) {
+	if (need_suspend_ops(state) && suspend_ops->begin) {
 		error = suspend_ops->begin(state);
 		if (error)
 			goto Close;
@@ -226,7 +266,7 @@ int suspend_devices_and_enter(suspend_state_t state)
 
 	do {
 		error = suspend_enter(state, &wakeup);
-	} while (!error && !wakeup
+	} while (!error && !wakeup && need_suspend_ops(state)
 		&& suspend_ops->suspend_again && suspend_ops->suspend_again());
 
  Resume_devices:
@@ -236,13 +276,13 @@ int suspend_devices_and_enter(suspend_state_t state)
 	ftrace_start();
 	resume_console();
  Close:
-	if (suspend_ops->end)
+	if (need_suspend_ops(state) && suspend_ops->end)
 		suspend_ops->end();
 	trace_machine_suspend(PWR_EVENT_EXIT);
 	return error;
 
  Recover_platform:
-	if (suspend_ops->recover)
+	if (need_suspend_ops(state) && suspend_ops->recover)
 		suspend_ops->recover();
 	goto Resume_devices;
 }
@@ -278,12 +318,15 @@ static int enter_state(suspend_state_t state)
 	if (!mutex_trylock(&pm_mutex))
 		return -EBUSY;
 
+	if (state == PM_SUSPEND_FREEZE)
+		freeze_begin();
+
 	printk(KERN_INFO "PM: Syncing filesystems ... ");
 	sys_sync();
 	printk("done.\n");
 
 	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
-	error = suspend_prepare();
+	error = suspend_prepare(state);
 	if (error)
 		goto Unlock;