Merge back PM core material for v4.16.

2 files changed, 163 insertions, 121 deletions

diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c
index 08744b572af6..6e8cc5de93fd 100644
--- a/drivers/base/power/main.c
+++ b/drivers/base/power/main.c
@@ -18,7 +18,6 @@
  */
 
 #include <linux/device.h>
-#include <linux/kallsyms.h>
 #include <linux/export.h>
 #include <linux/mutex.h>
 #include <linux/pm.h>
@@ -541,6 +540,18 @@ void dev_pm_skip_next_resume_phases(struct device *dev)
 }
 
 /**
+ * dev_pm_may_skip_resume - System-wide device resume optimization check.
+ * @dev: Target device.
+ *
+ * Checks whether or not the device may be left in suspend after a system-wide
+ * transition to the working state.
+ */
+bool dev_pm_may_skip_resume(struct device *dev)
+{
+	return !dev->power.must_resume && pm_transition.event != PM_EVENT_RESTORE;
+}
+
+/**
  * device_resume_noirq - Execute a "noirq resume" callback for given device.
  * @dev: Device to handle.
  * @state: PM transition of the system being carried out.
@@ -588,6 +599,18 @@ static int device_resume_noirq(struct device *dev, pm_message_t state, bool asyn
 	error = dpm_run_callback(callback, dev, state, info);
 	dev->power.is_noirq_suspended = false;
 
+	if (dev_pm_may_skip_resume(dev)) {
+		/*
+		 * The device is going to be left in suspend, but it might not
+		 * have been in runtime suspend before the system suspended, so
+		 * its runtime PM status needs to be updated to avoid confusing
+		 * the runtime PM framework when runtime PM is enabled for the
+		 * device again.
+		 */
+		pm_runtime_set_suspended(dev);
+		dev_pm_skip_next_resume_phases(dev);
+	}
+
  Out:
 	complete_all(&dev->power.completion);
 	TRACE_RESUME(error);
@@ -1089,6 +1112,22 @@ static pm_message_t resume_event(pm_message_t sleep_state)
 	return PMSG_ON;
 }
 
+static void dpm_superior_set_must_resume(struct device *dev)
+{
+	struct device_link *link;
+	int idx;
+
+	if (dev->parent)
+		dev->parent->power.must_resume = true;
+
+	idx = device_links_read_lock();
+
+	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node)
+		link->supplier->power.must_resume = true;
+
+	device_links_read_unlock(idx);
+}
+
 /**
  * __device_suspend_noirq - Execute a "noirq suspend" callback for given device.
  * @dev: Device to handle.
@@ -1140,10 +1179,28 @@ static int __device_suspend_noirq(struct device *dev, pm_message_t state, bool a
 	}
 
 	error = dpm_run_callback(callback, dev, state, info);
-	if (!error)
-		dev->power.is_noirq_suspended = true;
-	else
+	if (error) {
 		async_error = error;
+		goto Complete;
+	}
+
+	dev->power.is_noirq_suspended = true;
+
+	if (dev_pm_test_driver_flags(dev, DPM_FLAG_LEAVE_SUSPENDED)) {
+		/*
+		 * The only safe strategy here is to require that if the device
+		 * may not be left in suspend, resume callbacks must be invoked
+		 * for it.
+		 */
+		dev->power.must_resume = dev->power.must_resume ||
+					!dev->power.may_skip_resume ||
+					atomic_read(&dev->power.usage_count) > 1;
+	} else {
+		dev->power.must_resume = true;
+	}
+
+	if (dev->power.must_resume)
+		dpm_superior_set_must_resume(dev);
 
 Complete:
 	complete_all(&dev->power.completion);
@@ -1435,6 +1492,22 @@ static int legacy_suspend(struct device *dev, pm_message_t state,
 	return error;
 }
 
+static void dpm_propagate_to_parent(struct device *dev)
+{
+	struct device *parent = dev->parent;
+
+	if (!parent)
+		return;
+
+	spin_lock_irq(&parent->power.lock);
+
+	parent->power.direct_complete = false;
+	if (dev->power.wakeup_path && !parent->power.ignore_children)
+		parent->power.wakeup_path = true;
+
+	spin_unlock_irq(&parent->power.lock);
+}
+
 static void dpm_clear_suppliers_direct_complete(struct device *dev)
 {
 	struct device_link *link;
@@ -1500,6 +1573,9 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 		dev->power.direct_complete = false;
 	}
 
+	dev->power.may_skip_resume = false;
+	dev->power.must_resume = false;
+
 	dpm_watchdog_set(&wd, dev);
 	device_lock(dev);
 
@@ -1543,19 +1619,8 @@ static int __device_suspend(struct device *dev, pm_message_t state, bool async)
 
  End:
 	if (!error) {
-		struct device *parent = dev->parent;
-
 		dev->power.is_suspended = true;
-		if (parent) {
-			spin_lock_irq(&parent->power.lock);
-
-			dev->parent->power.direct_complete = false;
-			if (dev->power.wakeup_path
-			    && !dev->parent->power.ignore_children)
-				dev->parent->power.wakeup_path = true;
-
-			spin_unlock_irq(&parent->power.lock);
-		}
+		dpm_propagate_to_parent(dev);
 		dpm_clear_suppliers_direct_complete(dev);
 	}
 
@@ -1665,8 +1730,9 @@ static int device_prepare(struct device *dev, pm_message_t state)
 	if (dev->power.syscore)
 		return 0;
 
-	WARN_ON(dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND) &&
-		!pm_runtime_enabled(dev));
+	WARN_ON(!pm_runtime_enabled(dev) &&
+		dev_pm_test_driver_flags(dev, DPM_FLAG_SMART_SUSPEND |
+					      DPM_FLAG_LEAVE_SUSPENDED));
 
 	/*
 	 * If a device's parent goes into runtime suspend at the wrong time,
diff --git a/drivers/base/power/sysfs.c b/drivers/base/power/sysfs.c
index e153e28b1857..0f651efc58a1 100644
--- a/drivers/base/power/sysfs.c
+++ b/drivers/base/power/sysfs.c
@@ -108,16 +108,10 @@ static ssize_t control_show(struct device *dev, struct device_attribute *attr,
 static ssize_t control_store(struct device * dev, struct device_attribute *attr,
 			     const char * buf, size_t n)
 {
-	char *cp;
-	int len = n;
-
-	cp = memchr(buf, '\n', n);
-	if (cp)
-		len = cp - buf;
 	device_lock(dev);
-	if (len == sizeof ctrl_auto - 1 && strncmp(buf, ctrl_auto, len) == 0)
+	if (sysfs_streq(buf, ctrl_auto))
 		pm_runtime_allow(dev);
-	else if (len == sizeof ctrl_on - 1 && strncmp(buf, ctrl_on, len) == 0)
+	else if (sysfs_streq(buf, ctrl_on))
 		pm_runtime_forbid(dev);
 	else
 		n = -EINVAL;
@@ -125,9 +119,9 @@ static ssize_t control_store(struct device * dev, struct device_attribute *attr,
 	return n;
 }
 
-static DEVICE_ATTR(control, 0644, control_show, control_store);
+static DEVICE_ATTR_RW(control);
 
-static ssize_t rtpm_active_time_show(struct device *dev,
+static ssize_t runtime_active_time_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	int ret;
@@ -138,9 +132,9 @@ static ssize_t rtpm_active_time_show(struct device *dev,
 	return ret;
 }
 
-static DEVICE_ATTR(runtime_active_time, 0444, rtpm_active_time_show, NULL);
+static DEVICE_ATTR_RO(runtime_active_time);
 
-static ssize_t rtpm_suspended_time_show(struct device *dev,
+static ssize_t runtime_suspended_time_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	int ret;
@@ -152,9 +146,9 @@ static ssize_t rtpm_suspended_time_show(struct device *dev,
 	return ret;
 }
 
-static DEVICE_ATTR(runtime_suspended_time, 0444, rtpm_suspended_time_show, NULL);
+static DEVICE_ATTR_RO(runtime_suspended_time);
 
-static ssize_t rtpm_status_show(struct device *dev,
+static ssize_t runtime_status_show(struct device *dev,
 				struct device_attribute *attr, char *buf)
 {
 	const char *p;
@@ -184,7 +178,7 @@ static ssize_t rtpm_status_show(struct device *dev,
 	return sprintf(buf, p);
 }
 
-static DEVICE_ATTR(runtime_status, 0444, rtpm_status_show, NULL);
+static DEVICE_ATTR_RO(runtime_status);
 
 static ssize_t autosuspend_delay_ms_show(struct device *dev,
 		struct device_attribute *attr, char *buf)
@@ -211,26 +205,25 @@ static ssize_t autosuspend_delay_ms_store(struct device *dev,
 	return n;
 }
 
-static DEVICE_ATTR(autosuspend_delay_ms, 0644, autosuspend_delay_ms_show,
-		autosuspend_delay_ms_store);
+static DEVICE_ATTR_RW(autosuspend_delay_ms);
 
-static ssize_t pm_qos_resume_latency_show(struct device *dev,
-					  struct device_attribute *attr,
-					  char *buf)
+static ssize_t pm_qos_resume_latency_us_show(struct device *dev,
+					     struct device_attribute *attr,
+					     char *buf)
 {
 	s32 value = dev_pm_qos_requested_resume_latency(dev);
 
 	if (value == 0)
 		return sprintf(buf, "n/a\n");
-	else if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
+	if (value == PM_QOS_RESUME_LATENCY_NO_CONSTRAINT)
 		value = 0;
 
 	return sprintf(buf, "%d\n", value);
 }
 
-static ssize_t pm_qos_resume_latency_store(struct device *dev,
-					   struct device_attribute *attr,
-					   const char *buf, size_t n)
+static ssize_t pm_qos_resume_latency_us_store(struct device *dev,
+					      struct device_attribute *attr,
+					      const char *buf, size_t n)
 {
 	s32 value;
 	int ret;
@@ -245,7 +238,7 @@ static ssize_t pm_qos_resume_latency_store(struct device *dev,
 
 		if (value == 0)
 			value = PM_QOS_RESUME_LATENCY_NO_CONSTRAINT;
-	} else if (!strcmp(buf, "n/a") || !strcmp(buf, "n/a\n")) {
+	} else if (sysfs_streq(buf, "n/a")) {
 		value = 0;
 	} else {
 		return -EINVAL;
@@ -256,26 +249,25 @@ static ssize_t pm_qos_resume_latency_store(struct device *dev,
 	return ret < 0 ? ret : n;
 }
 
-static DEVICE_ATTR(pm_qos_resume_latency_us, 0644,
-		   pm_qos_resume_latency_show, pm_qos_resume_latency_store);
+static DEVICE_ATTR_RW(pm_qos_resume_latency_us);
 
-static ssize_t pm_qos_latency_tolerance_show(struct device *dev,
-					     struct device_attribute *attr,
-					     char *buf)
+static ssize_t pm_qos_latency_tolerance_us_show(struct device *dev,
+						struct device_attribute *attr,
+						char *buf)
 {
 	s32 value = dev_pm_qos_get_user_latency_tolerance(dev);
 
 	if (value < 0)
 		return sprintf(buf, "auto\n");
-	else if (value == PM_QOS_LATENCY_ANY)
+	if (value == PM_QOS_LATENCY_ANY)
 		return sprintf(buf, "any\n");
 
 	return sprintf(buf, "%d\n", value);
 }
 
-static ssize_t pm_qos_latency_tolerance_store(struct device *dev,
-					      struct device_attribute *attr,
-					      const char *buf, size_t n)
+static ssize_t pm_qos_latency_tolerance_us_store(struct device *dev,
+						 struct device_attribute *attr,
+						 const char *buf, size_t n)
 {
 	s32 value;
 	int ret;
@@ -285,9 +277,9 @@ static ssize_t pm_qos_latency_tolerance_store(struct device *dev,
 		if (value < 0)
 			return -EINVAL;
 	} else {
-		if (!strcmp(buf, "auto") || !strcmp(buf, "auto\n"))
+		if (sysfs_streq(buf, "auto"))
 			value = PM_QOS_LATENCY_TOLERANCE_NO_CONSTRAINT;
-		else if (!strcmp(buf, "any") || !strcmp(buf, "any\n"))
+		else if (sysfs_streq(buf, "any"))
 			value = PM_QOS_LATENCY_ANY;
 		else
 			return -EINVAL;
@@ -296,8 +288,7 @@ static ssize_t pm_qos_latency_tolerance_store(struct device *dev,
 	return ret < 0 ? ret : n;
 }
 
-static DEVICE_ATTR(pm_qos_latency_tolerance_us, 0644,
-		   pm_qos_latency_tolerance_show, pm_qos_latency_tolerance_store);
+static DEVICE_ATTR_RW(pm_qos_latency_tolerance_us);
 
 static ssize_t pm_qos_no_power_off_show(struct device *dev,
 					struct device_attribute *attr,
@@ -323,49 +314,39 @@ static ssize_t pm_qos_no_power_off_store(struct device *dev,
 	return ret < 0 ? ret : n;
 }
 
-static DEVICE_ATTR(pm_qos_no_power_off, 0644,
-		   pm_qos_no_power_off_show, pm_qos_no_power_off_store);
+static DEVICE_ATTR_RW(pm_qos_no_power_off);
 
 #ifdef CONFIG_PM_SLEEP
 static const char _enabled[] = "enabled";
 static const char _disabled[] = "disabled";
 
-static ssize_t
-wake_show(struct device * dev, struct device_attribute *attr, char * buf)
+static ssize_t wakeup_show(struct device *dev, struct device_attribute *attr,
+			   char *buf)
 {
 	return sprintf(buf, "%s\n", device_can_wakeup(dev)
 		? (device_may_wakeup(dev) ? _enabled : _disabled)
 		: "");
 }
 
-static ssize_t
-wake_store(struct device * dev, struct device_attribute *attr,
-	const char * buf, size_t n)
+static ssize_t wakeup_store(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t n)
 {
-	char *cp;
-	int len = n;
-
 	if (!device_can_wakeup(dev))
 		return -EINVAL;
 
-	cp = memchr(buf, '\n', n);
-	if (cp)
-		len = cp - buf;
-	if (len == sizeof _enabled - 1
-			&& strncmp(buf, _enabled, sizeof _enabled - 1) == 0)
+	if (sysfs_streq(buf, _enabled))
 		device_set_wakeup_enable(dev, 1);
-	else if (len == sizeof _disabled - 1
-			&& strncmp(buf, _disabled, sizeof _disabled - 1) == 0)
+	else if (sysfs_streq(buf, _disabled))
 		device_set_wakeup_enable(dev, 0);
 	else
 		return -EINVAL;
 	return n;
 }
 
-static DEVICE_ATTR(wakeup, 0644, wake_show, wake_store);
+static DEVICE_ATTR_RW(wakeup);
 
 static ssize_t wakeup_count_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
+				 struct device_attribute *attr, char *buf)
 {
 	unsigned long count = 0;
 	bool enabled = false;
@@ -379,10 +360,11 @@ static ssize_t wakeup_count_show(struct device *dev,
 	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
 }
 
-static DEVICE_ATTR(wakeup_count, 0444, wakeup_count_show, NULL);
+static DEVICE_ATTR_RO(wakeup_count);
 
 static ssize_t wakeup_active_count_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
+					struct device_attribute *attr,
+					char *buf)
 {
 	unsigned long count = 0;
 	bool enabled = false;
@@ -396,11 +378,11 @@ static ssize_t wakeup_active_count_show(struct device *dev,
 	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
 }
 
-static DEVICE_ATTR(wakeup_active_count, 0444, wakeup_active_count_show, NULL);
+static DEVICE_ATTR_RO(wakeup_active_count);
 
 static ssize_t wakeup_abort_count_show(struct device *dev,
-					struct device_attribute *attr,
-					char *buf)
+				       struct device_attribute *attr,
+				       char *buf)
 {
 	unsigned long count = 0;
 	bool enabled = false;
@@ -414,7 +396,7 @@ static ssize_t wakeup_abort_count_show(struct device *dev,
 	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
 }
 
-static DEVICE_ATTR(wakeup_abort_count, 0444, wakeup_abort_count_show, NULL);
+static DEVICE_ATTR_RO(wakeup_abort_count);
 
 static ssize_t wakeup_expire_count_show(struct device *dev,
 					struct device_attribute *attr,
@@ -432,10 +414,10 @@ static ssize_t wakeup_expire_count_show(struct device *dev,
 	return enabled ? sprintf(buf, "%lu\n", count) : sprintf(buf, "\n");
 }
 
-static DEVICE_ATTR(wakeup_expire_count, 0444, wakeup_expire_count_show, NULL);
+static DEVICE_ATTR_RO(wakeup_expire_count);
 
 static ssize_t wakeup_active_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
+				  struct device_attribute *attr, char *buf)
 {
 	unsigned int active = 0;
 	bool enabled = false;
@@ -449,10 +431,11 @@ static ssize_t wakeup_active_show(struct device *dev,
 	return enabled ? sprintf(buf, "%u\n", active) : sprintf(buf, "\n");
 }
 
-static DEVICE_ATTR(wakeup_active, 0444, wakeup_active_show, NULL);
+static DEVICE_ATTR_RO(wakeup_active);
 
-static ssize_t wakeup_total_time_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
+static ssize_t wakeup_total_time_ms_show(struct device *dev,
+					 struct device_attribute *attr,
+					 char *buf)
 {
 	s64 msec = 0;
 	bool enabled = false;
@@ -466,10 +449,10 @@ static ssize_t wakeup_total_time_show(struct device *dev,
 	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
 }
 
-static DEVICE_ATTR(wakeup_total_time_ms, 0444, wakeup_total_time_show, NULL);
+static DEVICE_ATTR_RO(wakeup_total_time_ms);
 
-static ssize_t wakeup_max_time_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
+static ssize_t wakeup_max_time_ms_show(struct device *dev,
+				       struct device_attribute *attr, char *buf)
 {
 	s64 msec = 0;
 	bool enabled = false;
@@ -483,10 +466,11 @@ static ssize_t wakeup_max_time_show(struct device *dev,
 	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
 }
 
-static DEVICE_ATTR(wakeup_max_time_ms, 0444, wakeup_max_time_show, NULL);
+static DEVICE_ATTR_RO(wakeup_max_time_ms);
 
-static ssize_t wakeup_last_time_show(struct device *dev,
-				struct device_attribute *attr, char *buf)
+static ssize_t wakeup_last_time_ms_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
 {
 	s64 msec = 0;
 	bool enabled = false;
@@ -500,12 +484,12 @@ static ssize_t wakeup_last_time_show(struct device *dev,
 	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
 }
 
-static DEVICE_ATTR(wakeup_last_time_ms, 0444, wakeup_last_time_show, NULL);
+static DEVICE_ATTR_RO(wakeup_last_time_ms);
 
 #ifdef CONFIG_PM_AUTOSLEEP
-static ssize_t wakeup_prevent_sleep_time_show(struct device *dev,
-					      struct device_attribute *attr,
-					      char *buf)
+static ssize_t wakeup_prevent_sleep_time_ms_show(struct device *dev,
+						 struct device_attribute *attr,
+						 char *buf)
 {
 	s64 msec = 0;
 	bool enabled = false;
@@ -519,40 +503,39 @@ static ssize_t wakeup_prevent_sleep_time_show(struct device *dev,
 	return enabled ? sprintf(buf, "%lld\n", msec) : sprintf(buf, "\n");
 }
 
-static DEVICE_ATTR(wakeup_prevent_sleep_time_ms, 0444,
-		   wakeup_prevent_sleep_time_show, NULL);
+static DEVICE_ATTR_RO(wakeup_prevent_sleep_time_ms);
 #endif /* CONFIG_PM_AUTOSLEEP */
 #endif /* CONFIG_PM_SLEEP */
 
 #ifdef CONFIG_PM_ADVANCED_DEBUG
-static ssize_t rtpm_usagecount_show(struct device *dev,
-				    struct device_attribute *attr, char *buf)
+static ssize_t runtime_usage_show(struct device *dev,
+				  struct device_attribute *attr, char *buf)
 {
 	return sprintf(buf, "%d\n", atomic_read(&dev->power.usage_count));
 }
+static DEVICE_ATTR_RO(runtime_usage);
 
-static ssize_t rtpm_children_show(struct device *dev,
-				  struct device_attribute *attr, char *buf)
+static ssize_t runtime_active_kids_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
 {
 	return sprintf(buf, "%d\n", dev->power.ignore_children ?
 		0 : atomic_read(&dev->power.child_count));
 }
+static DEVICE_ATTR_RO(runtime_active_kids);
 
-static ssize_t rtpm_enabled_show(struct device *dev,
-				 struct device_attribute *attr, char *buf)
+static ssize_t runtime_enabled_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
 {
-	if ((dev->power.disable_depth) && (dev->power.runtime_auto == false))
+	if (dev->power.disable_depth && (dev->power.runtime_auto == false))
 		return sprintf(buf, "disabled & forbidden\n");
-	else if (dev->power.disable_depth)
+	if (dev->power.disable_depth)
 		return sprintf(buf, "disabled\n");
-	else if (dev->power.runtime_auto == false)
+	if (dev->power.runtime_auto == false)
 		return sprintf(buf, "forbidden\n");
 	return sprintf(buf, "enabled\n");
 }
-
-static DEVICE_ATTR(runtime_usage, 0444, rtpm_usagecount_show, NULL);
-static DEVICE_ATTR(runtime_active_kids, 0444, rtpm_children_show, NULL);
-static DEVICE_ATTR(runtime_enabled, 0444, rtpm_enabled_show, NULL);
+static DEVICE_ATTR_RO(runtime_enabled);
 
 #ifdef CONFIG_PM_SLEEP
 static ssize_t async_show(struct device *dev, struct device_attribute *attr,
@@ -566,23 +549,16 @@ static ssize_t async_show(struct device *dev, struct device_attribute *attr,
 static ssize_t async_store(struct device *dev, struct device_attribute *attr,
 			   const char *buf, size_t n)
 {
-	char *cp;
-	int len = n;
-
-	cp = memchr(buf, '\n', n);
-	if (cp)
-		len = cp - buf;
-	if (len == sizeof _enabled - 1 && strncmp(buf, _enabled, len) == 0)
+	if (sysfs_streq(buf, _enabled))
 		device_enable_async_suspend(dev);
-	else if (len == sizeof _disabled - 1 &&
-		 strncmp(buf, _disabled, len) == 0)
+	else if (sysfs_streq(buf, _disabled))
 		device_disable_async_suspend(dev);
 	else
 		return -EINVAL;
 	return n;
 }
 
-static DEVICE_ATTR(async, 0644, async_show, async_store);
+static DEVICE_ATTR_RW(async);
 
 #endif /* CONFIG_PM_SLEEP */
 #endif /* CONFIG_PM_ADVANCED_DEBUG */