1 files changed, 383 insertions, 121 deletions

diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index ece04223bb1e..2da4482bb6eb 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -1,20 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0-only
 /*
  * kernel/power/suspend.c - Suspend to RAM and standby functionality.
  *
  * Copyright (c) 2003 Patrick Mochel
  * Copyright (c) 2003 Open Source Development Lab
  * Copyright (c) 2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
- *
- * This file is released under the GPLv2.
  */
 
+#define pr_fmt(fmt) "PM: " fmt
+
 #include <linux/string.h>
 #include <linux/delay.h>
 #include <linux/errno.h>
 #include <linux/init.h>
 #include <linux/console.h>
 #include <linux/cpu.h>
-#include <linux/syscalls.h>
+#include <linux/cpuidle.h>
 #include <linux/gfp.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
@@ -24,43 +25,193 @@
 #include <linux/export.h>
 #include <linux/suspend.h>
 #include <linux/syscore_ops.h>
+#include <linux/swait.h>
 #include <linux/ftrace.h>
 #include <trace/events/power.h>
+#include <linux/compiler.h>
+#include <linux/moduleparam.h>
+#include <linux/fs.h>
 
 #include "power.h"
 
-const char *const pm_states[PM_SUSPEND_MAX] = {
-	[PM_SUSPEND_FREEZE]	= "freeze",
-	[PM_SUSPEND_STANDBY]	= "standby",
-	[PM_SUSPEND_MEM]	= "mem",
+const char * const pm_labels[] = {
+	[PM_SUSPEND_TO_IDLE] = "freeze",
+	[PM_SUSPEND_STANDBY] = "standby",
+	[PM_SUSPEND_MEM] = "mem",
+};
+const char *pm_states[PM_SUSPEND_MAX];
+static const char * const mem_sleep_labels[] = {
+	[PM_SUSPEND_TO_IDLE] = "s2idle",
+	[PM_SUSPEND_STANDBY] = "shallow",
+	[PM_SUSPEND_MEM] = "deep",
 };
+const char *mem_sleep_states[PM_SUSPEND_MAX];
+
+suspend_state_t mem_sleep_current = PM_SUSPEND_TO_IDLE;
+suspend_state_t mem_sleep_default = PM_SUSPEND_MAX;
+suspend_state_t pm_suspend_target_state;
+EXPORT_SYMBOL_GPL(pm_suspend_target_state);
+
+unsigned int pm_suspend_global_flags;
+EXPORT_SYMBOL_GPL(pm_suspend_global_flags);
 
 static const struct platform_suspend_ops *suspend_ops;
+static const struct platform_s2idle_ops *s2idle_ops;
+static DECLARE_SWAIT_QUEUE_HEAD(s2idle_wait_head);
+
+enum s2idle_states __read_mostly s2idle_state;
+static DEFINE_RAW_SPINLOCK(s2idle_lock);
+
+/**
+ * pm_suspend_default_s2idle - Check if suspend-to-idle is the default suspend.
+ *
+ * Return 'true' if suspend-to-idle has been selected as the default system
+ * suspend method.
+ */
+bool pm_suspend_default_s2idle(void)
+{
+	return mem_sleep_current == PM_SUSPEND_TO_IDLE;
+}
+EXPORT_SYMBOL_GPL(pm_suspend_default_s2idle);
+
+void s2idle_set_ops(const struct platform_s2idle_ops *ops)
+{
+	unsigned int sleep_flags;
+
+	sleep_flags = lock_system_sleep();
+	s2idle_ops = ops;
+	unlock_system_sleep(sleep_flags);
+}
+
+static void s2idle_begin(void)
+{
+	s2idle_state = S2IDLE_STATE_NONE;
+}
 
-static bool need_suspend_ops(suspend_state_t state)
+static void s2idle_enter(void)
 {
-	return !!(state > PM_SUSPEND_FREEZE);
+	trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, true);
+
+	/*
+	 * The correctness of the code below depends on the number of online
+	 * CPUs being stable, but CPUs cannot be taken offline or put online
+	 * while it is running.
+	 *
+	 * The s2idle_lock must be acquired before the pending wakeup check to
+	 * prevent pm_system_wakeup() from running as a whole between that check
+	 * and the subsequent s2idle_state update in which case a wakeup event
+	 * would get lost.
+	 */
+	raw_spin_lock_irq(&s2idle_lock);
+	if (pm_wakeup_pending())
+		goto out;
+
+	s2idle_state = S2IDLE_STATE_ENTER;
+	raw_spin_unlock_irq(&s2idle_lock);
+
+	/* Push all the CPUs into the idle loop. */
+	wake_up_all_idle_cpus();
+	/* Make the current CPU wait so it can enter the idle loop too. */
+	swait_event_exclusive(s2idle_wait_head,
+		    s2idle_state == S2IDLE_STATE_WAKE);
+
+	/*
+	 * Kick all CPUs to ensure that they resume their timers and restore
+	 * consistent system state.
+	 */
+	wake_up_all_idle_cpus();
+
+	raw_spin_lock_irq(&s2idle_lock);
+
+ out:
+	s2idle_state = S2IDLE_STATE_NONE;
+	raw_spin_unlock_irq(&s2idle_lock);
+
+	trace_suspend_resume(TPS("machine_suspend"), PM_SUSPEND_TO_IDLE, false);
+}
+
+static void s2idle_loop(void)
+{
+	pm_pr_dbg("suspend-to-idle\n");
+
+	/*
+	 * Suspend-to-idle equals:
+	 * frozen processes + suspended devices + idle processors.
+	 * Thus s2idle_enter() should be called right after all devices have
+	 * been suspended.
+	 *
+	 * Wakeups during the noirq suspend of devices may be spurious, so try
+	 * to avoid them upfront.
+	 */
+	for (;;) {
+		if (s2idle_ops && s2idle_ops->wake) {
+			if (s2idle_ops->wake())
+				break;
+		} else if (pm_wakeup_pending()) {
+			break;
+		}
+
+		if (s2idle_ops && s2idle_ops->check)
+			s2idle_ops->check();
+
+		s2idle_enter();
+	}
+
+	pm_pr_dbg("resume from suspend-to-idle\n");
 }
 
-static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
-static bool suspend_freeze_wake;
+void s2idle_wake(void)
+{
+	unsigned long flags;
+
+	raw_spin_lock_irqsave(&s2idle_lock, flags);
+	if (s2idle_state > S2IDLE_STATE_NONE) {
+		s2idle_state = S2IDLE_STATE_WAKE;
+		swake_up_one(&s2idle_wait_head);
+	}
+	raw_spin_unlock_irqrestore(&s2idle_lock, flags);
+}
+EXPORT_SYMBOL_GPL(s2idle_wake);
 
-static void freeze_begin(void)
+static bool valid_state(suspend_state_t state)
 {
-	suspend_freeze_wake = false;
+	/*
+	 * The PM_SUSPEND_STANDBY and PM_SUSPEND_MEM states require low-level
+	 * support and need to be valid to the low-level implementation.
+	 *
+	 * No ->valid() or ->enter() callback implies that none are valid.
+	 */
+	return suspend_ops && suspend_ops->valid && suspend_ops->valid(state) &&
+		suspend_ops->enter;
 }
 
-static void freeze_enter(void)
+void __init pm_states_init(void)
 {
-	wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
+	/* "mem" and "freeze" are always present in /sys/power/state. */
+	pm_states[PM_SUSPEND_MEM] = pm_labels[PM_SUSPEND_MEM];
+	pm_states[PM_SUSPEND_TO_IDLE] = pm_labels[PM_SUSPEND_TO_IDLE];
+	/*
+	 * Suspend-to-idle should be supported even without any suspend_ops,
+	 * initialize mem_sleep_states[] accordingly here.
+	 */
+	mem_sleep_states[PM_SUSPEND_TO_IDLE] = mem_sleep_labels[PM_SUSPEND_TO_IDLE];
 }
 
-void freeze_wake(void)
+static int __init mem_sleep_default_setup(char *str)
 {
-	suspend_freeze_wake = true;
-	wake_up(&suspend_freeze_wait_head);
+	suspend_state_t state;
+
+	for (state = PM_SUSPEND_TO_IDLE; state <= PM_SUSPEND_MEM; state++)
+		if (mem_sleep_labels[state] &&
+		    !strcmp(str, mem_sleep_labels[state])) {
+			mem_sleep_default = state;
+			mem_sleep_current = state;
+			break;
+		}
+
+	return 1;
 }
-EXPORT_SYMBOL_GPL(freeze_wake);
+__setup("mem_sleep_default=", mem_sleep_default_setup);
 
 /**
  * suspend_set_ops - Set the global suspend method table.
@@ -68,38 +219,31 @@ EXPORT_SYMBOL_GPL(freeze_wake);
  */
 void suspend_set_ops(const struct platform_suspend_ops *ops)
 {
-	lock_system_sleep();
+	unsigned int sleep_flags;
+
+	sleep_flags = lock_system_sleep();
+
 	suspend_ops = ops;
-	unlock_system_sleep();
-}
-EXPORT_SYMBOL_GPL(suspend_set_ops);
 
-bool valid_state(suspend_state_t state)
-{
-	if (state == PM_SUSPEND_FREEZE) {
-#ifdef CONFIG_PM_DEBUG
-		if (pm_test_level != TEST_NONE &&
-		    pm_test_level != TEST_FREEZER &&
-		    pm_test_level != TEST_DEVICES &&
-		    pm_test_level != TEST_PLATFORM) {
-			printk(KERN_WARNING "Unsupported pm_test mode for "
-					"freeze state, please choose "
-					"none/freezer/devices/platform.\n");
-			return false;
-		}
-#endif
-			return true;
+	if (valid_state(PM_SUSPEND_STANDBY)) {
+		mem_sleep_states[PM_SUSPEND_STANDBY] = mem_sleep_labels[PM_SUSPEND_STANDBY];
+		pm_states[PM_SUSPEND_STANDBY] = pm_labels[PM_SUSPEND_STANDBY];
+		if (mem_sleep_default == PM_SUSPEND_STANDBY)
+			mem_sleep_current = PM_SUSPEND_STANDBY;
 	}
-	/*
-	 * 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);
+	if (valid_state(PM_SUSPEND_MEM)) {
+		mem_sleep_states[PM_SUSPEND_MEM] = mem_sleep_labels[PM_SUSPEND_MEM];
+		if (mem_sleep_default >= PM_SUSPEND_MEM)
+			mem_sleep_current = PM_SUSPEND_MEM;
+	}
+
+	unlock_system_sleep(sleep_flags);
 }
+EXPORT_SYMBOL_GPL(suspend_set_ops);
 
 /**
  * suspend_valid_only_mem - Generic memory-only valid callback.
+ * @state: Target system sleep state.
  *
  * Platform drivers that implement mem suspend only and only need to check for
  * that in their .valid() callback can use this instead of rolling their own
@@ -111,12 +255,103 @@ int suspend_valid_only_mem(suspend_state_t state)
 }
 EXPORT_SYMBOL_GPL(suspend_valid_only_mem);
 
+static bool sleep_state_supported(suspend_state_t state)
+{
+	return state == PM_SUSPEND_TO_IDLE ||
+	       (valid_state(state) && !cxl_mem_active());
+}
+
+static int platform_suspend_prepare(suspend_state_t state)
+{
+	return state != PM_SUSPEND_TO_IDLE && suspend_ops->prepare ?
+		suspend_ops->prepare() : 0;
+}
+
+static int platform_suspend_prepare_late(suspend_state_t state)
+{
+	return state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->prepare ?
+		s2idle_ops->prepare() : 0;
+}
+
+static int platform_suspend_prepare_noirq(suspend_state_t state)
+{
+	if (state == PM_SUSPEND_TO_IDLE)
+		return s2idle_ops && s2idle_ops->prepare_late ?
+			s2idle_ops->prepare_late() : 0;
+
+	return suspend_ops->prepare_late ? suspend_ops->prepare_late() : 0;
+}
+
+static void platform_resume_noirq(suspend_state_t state)
+{
+	if (state == PM_SUSPEND_TO_IDLE) {
+		if (s2idle_ops && s2idle_ops->restore_early)
+			s2idle_ops->restore_early();
+	} else if (suspend_ops->wake) {
+		suspend_ops->wake();
+	}
+}
+
+static void platform_resume_early(suspend_state_t state)
+{
+	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->restore)
+		s2idle_ops->restore();
+}
+
+static void platform_resume_finish(suspend_state_t state)
+{
+	if (state != PM_SUSPEND_TO_IDLE && suspend_ops->finish)
+		suspend_ops->finish();
+}
+
+static int platform_suspend_begin(suspend_state_t state)
+{
+	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->begin)
+		return s2idle_ops->begin();
+	else if (suspend_ops && suspend_ops->begin)
+		return suspend_ops->begin(state);
+	else
+		return 0;
+}
+
+static void platform_resume_end(suspend_state_t state)
+{
+	if (state == PM_SUSPEND_TO_IDLE && s2idle_ops && s2idle_ops->end)
+		s2idle_ops->end();
+	else if (suspend_ops && suspend_ops->end)
+		suspend_ops->end();
+}
+
+static void platform_recover(suspend_state_t state)
+{
+	if (state != PM_SUSPEND_TO_IDLE && suspend_ops->recover)
+		suspend_ops->recover();
+}
+
+static bool platform_suspend_again(suspend_state_t state)
+{
+	return state != PM_SUSPEND_TO_IDLE && suspend_ops->suspend_again ?
+		suspend_ops->suspend_again() : false;
+}
+
+#ifdef CONFIG_PM_DEBUG
+static unsigned int pm_test_delay = 5;
+module_param(pm_test_delay, uint, 0644);
+MODULE_PARM_DESC(pm_test_delay,
+		 "Number of seconds to wait before resuming from suspend test");
+#endif
+
 static int suspend_test(int level)
 {
 #ifdef CONFIG_PM_DEBUG
+	int i;
+
 	if (pm_test_level == level) {
-		printk(KERN_INFO "suspend debug: Waiting for 5 seconds.\n");
-		mdelay(5000);
+		pr_info("suspend debug: Waiting for %d second(s).\n",
+				pm_test_delay);
+		for (i = 0; i < pm_test_delay && !pm_wakeup_pending(); i++)
+			msleep(1000);
+
 		return 1;
 	}
 #endif /* !CONFIG_PM_DEBUG */
@@ -125,6 +360,7 @@ static int suspend_test(int level)
 
 /**
  * suspend_prepare - Prepare for entering system sleep state.
+ * @state: Target system sleep state.
  *
  * Common code run for every system sleep state that can be entered (except for
  * hibernation).  Run suspend notifiers, allocate the "suspend" console and
@@ -134,35 +370,38 @@ static int suspend_prepare(suspend_state_t state)
 {
 	int error;
 
-	if (need_suspend_ops(state) && (!suspend_ops || !suspend_ops->enter))
+	if (!sleep_state_supported(state))
 		return -EPERM;
 
 	pm_prepare_console();
 
-	error = pm_notifier_call_chain(PM_SUSPEND_PREPARE);
+	error = pm_notifier_call_chain_robust(PM_SUSPEND_PREPARE, PM_POST_SUSPEND);
 	if (error)
-		goto Finish;
+		goto Restore;
 
+	filesystems_freeze(filesystem_freeze_enabled);
+	trace_suspend_resume(TPS("freeze_processes"), 0, true);
 	error = suspend_freeze_processes();
+	trace_suspend_resume(TPS("freeze_processes"), 0, false);
 	if (!error)
 		return 0;
 
-	suspend_stats.failed_freeze++;
 	dpm_save_failed_step(SUSPEND_FREEZE);
- Finish:
+	filesystems_thaw();
 	pm_notifier_call_chain(PM_POST_SUSPEND);
+ Restore:
 	pm_restore_console();
 	return error;
 }
 
 /* default implementation */
-void __attribute__ ((weak)) arch_suspend_disable_irqs(void)
+void __weak arch_suspend_disable_irqs(void)
 {
 	local_irq_disable();
 }
 
 /* default implementation */
-void __attribute__ ((weak)) arch_suspend_enable_irqs(void)
+void __weak arch_suspend_enable_irqs(void)
 {
 	local_irq_enable();
 }
@@ -178,71 +417,80 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 {
 	int error;
 
-	if (need_suspend_ops(state) && suspend_ops->prepare) {
-		error = suspend_ops->prepare();
-		if (error)
-			goto Platform_finish;
-	}
+	error = platform_suspend_prepare(state);
+	if (error)
+		goto Platform_finish;
 
-	error = dpm_suspend_end(PMSG_SUSPEND);
+	error = dpm_suspend_late(PMSG_SUSPEND);
 	if (error) {
-		printk(KERN_ERR "PM: Some devices failed to power down\n");
+		pr_err("late suspend of devices failed\n");
 		goto Platform_finish;
 	}
+	error = platform_suspend_prepare_late(state);
+	if (error)
+		goto Devices_early_resume;
 
-	if (need_suspend_ops(state) && suspend_ops->prepare_late) {
-		error = suspend_ops->prepare_late();
-		if (error)
-			goto Platform_wake;
+	error = dpm_suspend_noirq(PMSG_SUSPEND);
+	if (error) {
+		pr_err("noirq suspend of devices failed\n");
+		goto Platform_early_resume;
 	}
+	error = platform_suspend_prepare_noirq(state);
+	if (error)
+		goto Platform_wake;
 
 	if (suspend_test(TEST_PLATFORM))
 		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();
+	if (state == PM_SUSPEND_TO_IDLE) {
+		s2idle_loop();
 		goto Platform_wake;
 	}
 
-	error = disable_nonboot_cpus();
+	error = pm_sleep_disable_secondary_cpus();
 	if (error || suspend_test(TEST_CPUS))
 		goto Enable_cpus;
 
 	arch_suspend_disable_irqs();
 	BUG_ON(!irqs_disabled());
 
+	system_state = SYSTEM_SUSPEND;
+
 	error = syscore_suspend();
 	if (!error) {
 		*wakeup = pm_wakeup_pending();
 		if (!(suspend_test(TEST_CORE) || *wakeup)) {
+			trace_suspend_resume(TPS("machine_suspend"),
+				state, true);
 			error = suspend_ops->enter(state);
-			events_check_enabled = false;
+			trace_suspend_resume(TPS("machine_suspend"),
+				state, false);
+		} else if (*wakeup) {
+			error = -EBUSY;
 		}
 		syscore_resume();
 	}
 
+	system_state = SYSTEM_RUNNING;
+
 	arch_suspend_enable_irqs();
 	BUG_ON(irqs_disabled());
 
  Enable_cpus:
-	enable_nonboot_cpus();
+	pm_sleep_enable_secondary_cpus();
 
  Platform_wake:
-	if (need_suspend_ops(state) && suspend_ops->wake)
-		suspend_ops->wake();
+	platform_resume_noirq(state);
+	dpm_resume_noirq(PMSG_RESUME);
 
-	dpm_resume_start(PMSG_RESUME);
+ Platform_early_resume:
+	platform_resume_early(state);
 
- Platform_finish:
-	if (need_suspend_ops(state) && suspend_ops->finish)
-		suspend_ops->finish();
+ Devices_early_resume:
+	dpm_resume_early(PMSG_RESUME);
 
+ Platform_finish:
+	platform_resume_finish(state);
 	return error;
 }
 
@@ -255,21 +503,23 @@ int suspend_devices_and_enter(suspend_state_t state)
 	int error;
 	bool wakeup = false;
 
-	if (need_suspend_ops(state) && !suspend_ops)
+	if (!sleep_state_supported(state))
 		return -ENOSYS;
 
-	trace_machine_suspend(state);
-	if (need_suspend_ops(state) && suspend_ops->begin) {
-		error = suspend_ops->begin(state);
-		if (error)
-			goto Close;
-	}
-	suspend_console();
-	ftrace_stop();
+	pm_suspend_target_state = state;
+
+	if (state == PM_SUSPEND_TO_IDLE)
+		pm_set_suspend_no_platform();
+
+	error = platform_suspend_begin(state);
+	if (error)
+		goto Close;
+
+	console_suspend_all();
 	suspend_test_start();
 	error = dpm_suspend_start(PMSG_SUSPEND);
 	if (error) {
-		pr_err("PM: Some devices failed to suspend, or early wake event detected\n");
+		pr_err("Some devices failed to suspend, or early wake event detected\n");
 		goto Recover_platform;
 	}
 	suspend_test_finish("suspend devices");
@@ -278,24 +528,23 @@ int suspend_devices_and_enter(suspend_state_t state)
 
 	do {
 		error = suspend_enter(state, &wakeup);
-	} while (!error && !wakeup && need_suspend_ops(state)
-		&& suspend_ops->suspend_again && suspend_ops->suspend_again());
+	} while (!error && !wakeup && platform_suspend_again(state));
 
  Resume_devices:
 	suspend_test_start();
 	dpm_resume_end(PMSG_RESUME);
 	suspend_test_finish("resume devices");
-	ftrace_start();
-	resume_console();
+	trace_suspend_resume(TPS("console_resume_all"), state, true);
+	console_resume_all();
+	trace_suspend_resume(TPS("console_resume_all"), state, false);
+
  Close:
-	if (need_suspend_ops(state) && suspend_ops->end)
-		suspend_ops->end();
-	trace_machine_suspend(PWR_EVENT_EXIT);
+	platform_resume_end(state);
+	pm_suspend_target_state = PM_SUSPEND_ON;
 	return error;
 
  Recover_platform:
-	if (need_suspend_ops(state) && suspend_ops->recover)
-		suspend_ops->recover();
+	platform_recover(state);
 	goto Resume_devices;
 }
 
@@ -308,6 +557,7 @@ int suspend_devices_and_enter(suspend_state_t state)
 static void suspend_finish(void)
 {
 	suspend_thaw_processes();
+	filesystems_thaw();
 	pm_notifier_call_chain(PM_POST_SUSPEND);
 	pm_restore_console();
 }
@@ -324,20 +574,35 @@ static int enter_state(suspend_state_t state)
 {
 	int error;
 
-	if (!valid_state(state))
-		return -ENODEV;
-
-	if (!mutex_trylock(&pm_mutex))
+	trace_suspend_resume(TPS("suspend_enter"), state, true);
+	if (state == PM_SUSPEND_TO_IDLE) {
+#ifdef CONFIG_PM_DEBUG
+		if (pm_test_level != TEST_NONE && pm_test_level <= TEST_CPUS) {
+			pr_warn("Unsupported test mode for suspend to idle, please choose none/freezer/devices/platform.\n");
+			return -EAGAIN;
+		}
+#endif
+	} else if (!valid_state(state)) {
+		return -EINVAL;
+	}
+	if (!mutex_trylock(&system_transition_mutex))
 		return -EBUSY;
 
-	if (state == PM_SUSPEND_FREEZE)
-		freeze_begin();
+	if (state == PM_SUSPEND_TO_IDLE)
+		s2idle_begin();
 
-	printk(KERN_INFO "PM: Syncing filesystems ... ");
-	sys_sync();
-	printk("done.\n");
+	if (sync_on_suspend_enabled) {
+		trace_suspend_resume(TPS("sync_filesystems"), 0, true);
+
+		error = pm_sleep_fs_sync();
+		if (error)
+			goto Unlock;
 
-	pr_debug("PM: Preparing system for %s sleep\n", pm_states[state]);
+		trace_suspend_resume(TPS("sync_filesystems"), 0, false);
+	}
+
+	pm_pr_dbg("Preparing system for sleep (%s)\n", mem_sleep_labels[state]);
+	pm_suspend_clear_flags();
 	error = suspend_prepare(state);
 	if (error)
 		goto Unlock;
@@ -345,16 +610,16 @@ static int enter_state(suspend_state_t state)
 	if (suspend_test(TEST_FREEZER))
 		goto Finish;
 
-	pr_debug("PM: Entering %s sleep\n", pm_states[state]);
-	pm_restrict_gfp_mask();
+	trace_suspend_resume(TPS("suspend_enter"), state, false);
+	pm_pr_dbg("Suspending system (%s)\n", mem_sleep_labels[state]);
 	error = suspend_devices_and_enter(state);
-	pm_restore_gfp_mask();
 
  Finish:
-	pr_debug("PM: Finishing wakeup.\n");
+	events_check_enabled = false;
+	pm_pr_dbg("Finishing wakeup.\n");
 	suspend_finish();
  Unlock:
-	mutex_unlock(&pm_mutex);
+	mutex_unlock(&system_transition_mutex);
 	return error;
 }
 
@@ -372,13 +637,10 @@ int pm_suspend(suspend_state_t state)
 	if (state <= PM_SUSPEND_ON || state >= PM_SUSPEND_MAX)
 		return -EINVAL;
 
+	pr_info("suspend entry (%s)\n", mem_sleep_labels[state]);
 	error = enter_state(state);
-	if (error) {
-		suspend_stats.fail++;
-		dpm_save_failed_errno(error);
-	} else {
-		suspend_stats.success++;
-	}
+	dpm_save_errno(error);
+	pr_info("suspend exit\n");
 	return error;
 }
 EXPORT_SYMBOL(pm_suspend);