5 files changed, 154 insertions, 67 deletions

diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index 48b28d387c7f..7e01f78f0417 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -251,6 +251,7 @@ config APM_EMULATION
 
 config PM_OPP
 	bool
+	select SRCU
 	---help---
 	  SOCs have a standard set of tuples consisting of frequency and
 	  voltage pairs that the device will support per voltage domain. This
diff --git a/kernel/power/process.c b/kernel/power/process.c
index 5a6ec8678b9a..564f786df470 100644
--- a/kernel/power/process.c
+++ b/kernel/power/process.c
@@ -84,8 +84,8 @@ static int try_to_freeze_tasks(bool user_only)
 	elapsed_msecs = elapsed_msecs64;
 
 	if (todo) {
-		printk("\n");
-		printk(KERN_ERR "Freezing of tasks %s after %d.%03d seconds "
+		pr_cont("\n");
+		pr_err("Freezing of tasks %s after %d.%03d seconds "
 		       "(%d tasks refusing to freeze, wq_busy=%d):\n",
 		       wakeup ? "aborted" : "failed",
 		       elapsed_msecs / 1000, elapsed_msecs % 1000,
@@ -101,37 +101,13 @@ static int try_to_freeze_tasks(bool user_only)
 			read_unlock(&tasklist_lock);
 		}
 	} else {
-		printk("(elapsed %d.%03d seconds) ", elapsed_msecs / 1000,
+		pr_cont("(elapsed %d.%03d seconds) ", elapsed_msecs / 1000,
 			elapsed_msecs % 1000);
 	}
 
 	return todo ? -EBUSY : 0;
 }
 
-static bool __check_frozen_processes(void)
-{
-	struct task_struct *g, *p;
-
-	for_each_process_thread(g, p)
-		if (p != current && !freezer_should_skip(p) && !frozen(p))
-			return false;
-
-	return true;
-}
-
-/*
- * Returns true if all freezable tasks (except for current) are frozen already
- */
-static bool check_frozen_processes(void)
-{
-	bool ret;
-
-	read_lock(&tasklist_lock);
-	ret = __check_frozen_processes();
-	read_unlock(&tasklist_lock);
-	return ret;
-}
-
 /**
  * freeze_processes - Signal user space processes to enter the refrigerator.
  * The current thread will not be frozen.  The same process that calls
@@ -142,7 +118,6 @@ static bool check_frozen_processes(void)
 int freeze_processes(void)
 {
 	int error;
-	int oom_kills_saved;
 
 	error = __usermodehelper_disable(UMH_FREEZING);
 	if (error)
@@ -155,31 +130,24 @@ int freeze_processes(void)
 		atomic_inc(&system_freezing_cnt);
 
 	pm_wakeup_clear();
-	printk("Freezing user space processes ... ");
+	pr_info("Freezing user space processes ... ");
 	pm_freezing = true;
-	oom_kills_saved = oom_kills_count();
 	error = try_to_freeze_tasks(true);
 	if (!error) {
 		__usermodehelper_set_disable_depth(UMH_DISABLED);
-		oom_killer_disable();
-
-		/*
-		 * There might have been an OOM kill while we were
-		 * freezing tasks and the killed task might be still
-		 * on the way out so we have to double check for race.
-		 */
-		if (oom_kills_count() != oom_kills_saved &&
-		    !check_frozen_processes()) {
-			__usermodehelper_set_disable_depth(UMH_ENABLED);
-			printk("OOM in progress.");
-			error = -EBUSY;
-		} else {
-			printk("done.");
-		}
+		pr_cont("done.");
 	}
-	printk("\n");
+	pr_cont("\n");
 	BUG_ON(in_atomic());
 
+	/*
+	 * Now that the whole userspace is frozen we need to disbale
+	 * the OOM killer to disallow any further interference with
+	 * killable tasks.
+	 */
+	if (!error && !oom_killer_disable())
+		error = -EBUSY;
+
 	if (error)
 		thaw_processes();
 	return error;
@@ -197,13 +165,14 @@ int freeze_kernel_threads(void)
 {
 	int error;
 
-	printk("Freezing remaining freezable tasks ... ");
+	pr_info("Freezing remaining freezable tasks ... ");
+
 	pm_nosig_freezing = true;
 	error = try_to_freeze_tasks(false);
 	if (!error)
-		printk("done.");
+		pr_cont("done.");
 
-	printk("\n");
+	pr_cont("\n");
 	BUG_ON(in_atomic());
 
 	if (error)
@@ -224,7 +193,7 @@ void thaw_processes(void)
 
 	oom_killer_enable();
 
-	printk("Restarting tasks ... ");
+	pr_info("Restarting tasks ... ");
 
 	__usermodehelper_set_disable_depth(UMH_FREEZING);
 	thaw_workqueues();
@@ -243,7 +212,7 @@ void thaw_processes(void)
 	usermodehelper_enable();
 
 	schedule();
-	printk("done.\n");
+	pr_cont("done.\n");
 	trace_suspend_resume(TPS("thaw_processes"), 0, false);
 }
 
@@ -252,7 +221,7 @@ void thaw_kernel_threads(void)
 	struct task_struct *g, *p;
 
 	pm_nosig_freezing = false;
-	printk("Restarting kernel threads ... ");
+	pr_info("Restarting kernel threads ... ");
 
 	thaw_workqueues();
 
@@ -264,5 +233,5 @@ void thaw_kernel_threads(void)
 	read_unlock(&tasklist_lock);
 
 	schedule();
-	printk("done.\n");
+	pr_cont("done.\n");
 }
diff --git a/kernel/power/qos.c b/kernel/power/qos.c
index 5f4c006c4b1e..97b0df71303e 100644
--- a/kernel/power/qos.c
+++ b/kernel/power/qos.c
@@ -41,6 +41,8 @@
 #include <linux/platform_device.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
 
 #include <linux/uaccess.h>
 #include <linux/export.h>
@@ -182,6 +184,81 @@ static inline void pm_qos_set_value(struct pm_qos_constraints *c, s32 value)
 	c->target_value = value;
 }
 
+static inline int pm_qos_get_value(struct pm_qos_constraints *c);
+static int pm_qos_dbg_show_requests(struct seq_file *s, void *unused)
+{
+	struct pm_qos_object *qos = (struct pm_qos_object *)s->private;
+	struct pm_qos_constraints *c;
+	struct pm_qos_request *req;
+	char *type;
+	unsigned long flags;
+	int tot_reqs = 0;
+	int active_reqs = 0;
+
+	if (IS_ERR_OR_NULL(qos)) {
+		pr_err("%s: bad qos param!\n", __func__);
+		return -EINVAL;
+	}
+	c = qos->constraints;
+	if (IS_ERR_OR_NULL(c)) {
+		pr_err("%s: Bad constraints on qos?\n", __func__);
+		return -EINVAL;
+	}
+
+	/* Lock to ensure we have a snapshot */
+	spin_lock_irqsave(&pm_qos_lock, flags);
+	if (plist_head_empty(&c->list)) {
+		seq_puts(s, "Empty!\n");
+		goto out;
+	}
+
+	switch (c->type) {
+	case PM_QOS_MIN:
+		type = "Minimum";
+		break;
+	case PM_QOS_MAX:
+		type = "Maximum";
+		break;
+	case PM_QOS_SUM:
+		type = "Sum";
+		break;
+	default:
+		type = "Unknown";
+	}
+
+	plist_for_each_entry(req, &c->list, node) {
+		char *state = "Default";
+
+		if ((req->node).prio != c->default_value) {
+			active_reqs++;
+			state = "Active";
+		}
+		tot_reqs++;
+		seq_printf(s, "%d: %d: %s\n", tot_reqs,
+			   (req->node).prio, state);
+	}
+
+	seq_printf(s, "Type=%s, Value=%d, Requests: active=%d / total=%d\n",
+		   type, pm_qos_get_value(c), active_reqs, tot_reqs);
+
+out:
+	spin_unlock_irqrestore(&pm_qos_lock, flags);
+	return 0;
+}
+
+static int pm_qos_dbg_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, pm_qos_dbg_show_requests,
+			   inode->i_private);
+}
+
+static const struct file_operations pm_qos_debug_fops = {
+	.open           = pm_qos_dbg_open,
+	.read           = seq_read,
+	.llseek         = seq_lseek,
+	.release        = single_release,
+};
+
 /**
  * pm_qos_update_target - manages the constraints list and calls the notifiers
  *  if needed
@@ -509,12 +586,17 @@ int pm_qos_remove_notifier(int pm_qos_class, struct notifier_block *notifier)
 EXPORT_SYMBOL_GPL(pm_qos_remove_notifier);
 
 /* User space interface to PM QoS classes via misc devices */
-static int register_pm_qos_misc(struct pm_qos_object *qos)
+static int register_pm_qos_misc(struct pm_qos_object *qos, struct dentry *d)
 {
 	qos->pm_qos_power_miscdev.minor = MISC_DYNAMIC_MINOR;
 	qos->pm_qos_power_miscdev.name = qos->name;
 	qos->pm_qos_power_miscdev.fops = &pm_qos_power_fops;
 
+	if (d) {
+		(void)debugfs_create_file(qos->name, S_IRUGO, d,
+					  (void *)qos, &pm_qos_debug_fops);
+	}
+
 	return misc_register(&qos->pm_qos_power_miscdev);
 }
 
@@ -608,11 +690,16 @@ static int __init pm_qos_power_init(void)
 {
 	int ret = 0;
 	int i;
+	struct dentry *d;
 
 	BUILD_BUG_ON(ARRAY_SIZE(pm_qos_array) != PM_QOS_NUM_CLASSES);
 
+	d = debugfs_create_dir("pm_qos", NULL);
+	if (IS_ERR_OR_NULL(d))
+		d = NULL;
+
 	for (i = PM_QOS_CPU_DMA_LATENCY; i < PM_QOS_NUM_CLASSES; i++) {
-		ret = register_pm_qos_misc(pm_qos_array[i]);
+		ret = register_pm_qos_misc(pm_qos_array[i], d);
 		if (ret < 0) {
 			printk(KERN_ERR "pm_qos_param: %s setup failed\n",
 			       pm_qos_array[i]->name);
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 0c40c16174b4..c24d5a23bf93 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -1472,9 +1472,9 @@ static inline unsigned long preallocate_highmem_fraction(unsigned long nr_pages,
 /**
  * free_unnecessary_pages - Release preallocated pages not needed for the image
  */
-static void free_unnecessary_pages(void)
+static unsigned long free_unnecessary_pages(void)
 {
-	unsigned long save, to_free_normal, to_free_highmem;
+	unsigned long save, to_free_normal, to_free_highmem, free;
 
 	save = count_data_pages();
 	if (alloc_normal >= save) {
@@ -1495,6 +1495,7 @@ static void free_unnecessary_pages(void)
 		else
 			to_free_normal = 0;
 	}
+	free = to_free_normal + to_free_highmem;
 
 	memory_bm_position_reset(&copy_bm);
 
@@ -1518,6 +1519,8 @@ static void free_unnecessary_pages(void)
 		swsusp_unset_page_free(page);
 		__free_page(page);
 	}
+
+	return free;
 }
 
 /**
@@ -1707,7 +1710,7 @@ int hibernate_preallocate_memory(void)
 	 * pages in memory, but we have allocated more.  Release the excessive
 	 * ones now.
 	 */
-	free_unnecessary_pages();
+	pages -= free_unnecessary_pages();
 
  out:
 	stop = ktime_get();
@@ -2310,8 +2313,6 @@ static inline void free_highmem_data(void)
 		free_image_page(buffer, PG_UNSAFE_CLEAR);
 }
 #else
-static inline int get_safe_write_buffer(void) { return 0; }
-
 static unsigned int
 count_highmem_image_pages(struct memory_bitmap *bm) { return 0; }
 
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index c347e3ce3a55..b7d6b3a721b1 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -37,7 +37,9 @@ const char *pm_states[PM_SUSPEND_MAX];
 static const struct platform_suspend_ops *suspend_ops;
 static const struct platform_freeze_ops *freeze_ops;
 static DECLARE_WAIT_QUEUE_HEAD(suspend_freeze_wait_head);
-static bool suspend_freeze_wake;
+
+enum freeze_state __read_mostly suspend_freeze_state;
+static DEFINE_SPINLOCK(suspend_freeze_lock);
 
 void freeze_set_ops(const struct platform_freeze_ops *ops)
 {
@@ -48,22 +50,49 @@ void freeze_set_ops(const struct platform_freeze_ops *ops)
 
 static void freeze_begin(void)
 {
-	suspend_freeze_wake = false;
+	suspend_freeze_state = FREEZE_STATE_NONE;
 }
 
 static void freeze_enter(void)
 {
-	cpuidle_use_deepest_state(true);
+	spin_lock_irq(&suspend_freeze_lock);
+	if (pm_wakeup_pending())
+		goto out;
+
+	suspend_freeze_state = FREEZE_STATE_ENTER;
+	spin_unlock_irq(&suspend_freeze_lock);
+
+	get_online_cpus();
 	cpuidle_resume();
-	wait_event(suspend_freeze_wait_head, suspend_freeze_wake);
+
+	/* Push all the CPUs into the idle loop. */
+	wake_up_all_idle_cpus();
+	pr_debug("PM: suspend-to-idle\n");
+	/* Make the current CPU wait so it can enter the idle loop too. */
+	wait_event(suspend_freeze_wait_head,
+		   suspend_freeze_state == FREEZE_STATE_WAKE);
+	pr_debug("PM: resume from suspend-to-idle\n");
+
 	cpuidle_pause();
-	cpuidle_use_deepest_state(false);
+	put_online_cpus();
+
+	spin_lock_irq(&suspend_freeze_lock);
+
+ out:
+	suspend_freeze_state = FREEZE_STATE_NONE;
+	spin_unlock_irq(&suspend_freeze_lock);
 }
 
 void freeze_wake(void)
 {
-	suspend_freeze_wake = true;
-	wake_up(&suspend_freeze_wait_head);
+	unsigned long flags;
+
+	spin_lock_irqsave(&suspend_freeze_lock, flags);
+	if (suspend_freeze_state > FREEZE_STATE_NONE) {
+		suspend_freeze_state = FREEZE_STATE_WAKE;
+		wake_up(&suspend_freeze_wait_head);
+	}
+	spin_unlock_irqrestore(&suspend_freeze_lock, flags);
 }
 EXPORT_SYMBOL_GPL(freeze_wake);