Merge branches 'pm-cpuidle', 'pm-sleep' and 'pm-domains'

* pm-cpuidle:
  cpuidle: menu: help gcc generate slightly better code
  cpuidle: menu: avoid expensive square root computation

* pm-sleep:
  PM / suspend: replacing printk
  PM/freezer: y2038, use boottime to compare tstamps
  PM / sleep: declare __tracedata symbols as char[] rather than char

* pm-domains:
  PM / Domains: Fix potential NULL pointer dereference
  PM / Domains: Fix removal of a subdomain
  PM / Domains: Propagate start and restore errors during runtime resume
  PM / Domains: Join state name and index in debugfs output
  PM / Domains: Restore alignment of slaves in debugfs output
  PM / Domains: remove old power on/off latencies
  ARM: imx6: pm: declare pm domain latency on power_state struct
  PM / Domains: Support for multiple states

arch/arm/mach-imx/gpc.c

@@ -374,9 +374,14 @@ static struct pu_domain imx6q_pu_domain = {
 		.name = "PU",
 		.power_off = imx6q_pm_pu_power_off,
 		.power_on = imx6q_pm_pu_power_on,
+		.states = {
+			[0] = {
 				.power_off_latency_ns = 25000,
 				.power_on_latency_ns = 2000000,
 			},
+		},
+		.state_count = 1,
+	},
 };
 
 static struct generic_pm_domain imx6sl_display_domain = {

drivers/base/power/domain.c

@@ -104,6 +104,7 @@ static void genpd_sd_counter_inc(struct generic_pm_domain *genpd)
 
 static int genpd_power_on(struct generic_pm_domain *genpd, bool timed)
 {
+	unsigned int state_idx = genpd->state_idx;
 	ktime_t time_start;
 	s64 elapsed_ns;
 	int ret;
@@ -120,10 +121,10 @@ static int genpd_power_on(struct generic_pm_domain *genpd, bool timed)
 		return ret;
 
 	elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
-	if (elapsed_ns <= genpd->power_on_latency_ns)
+	if (elapsed_ns <= genpd->states[state_idx].power_on_latency_ns)
 		return ret;
 
-	genpd->power_on_latency_ns = elapsed_ns;
+	genpd->states[state_idx].power_on_latency_ns = elapsed_ns;
 	genpd->max_off_time_changed = true;
 	pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
 		 genpd->name, "on", elapsed_ns);
@@ -133,6 +134,7 @@ static int genpd_power_on(struct generic_pm_domain *genpd, bool timed)
 
 static int genpd_power_off(struct generic_pm_domain *genpd, bool timed)
 {
+	unsigned int state_idx = genpd->state_idx;
 	ktime_t time_start;
 	s64 elapsed_ns;
 	int ret;
@@ -149,10 +151,10 @@ static int genpd_power_off(struct generic_pm_domain *genpd, bool timed)
 		return ret;
 
 	elapsed_ns = ktime_to_ns(ktime_sub(ktime_get(), time_start));
-	if (elapsed_ns <= genpd->power_off_latency_ns)
+	if (elapsed_ns <= genpd->states[state_idx].power_off_latency_ns)
 		return ret;
 
-	genpd->power_off_latency_ns = elapsed_ns;
+	genpd->states[state_idx].power_off_latency_ns = elapsed_ns;
 	genpd->max_off_time_changed = true;
 	pr_debug("%s: Power-%s latency exceeded, new value %lld ns\n",
 		 genpd->name, "off", elapsed_ns);
@@ -485,8 +487,13 @@ static int pm_genpd_runtime_resume(struct device *dev)
 	if (timed && runtime_pm)
 		time_start = ktime_get();
 
-	genpd_start_dev(genpd, dev);
-	genpd_restore_dev(genpd, dev);
+	ret = genpd_start_dev(genpd, dev);
+	if (ret)
+		goto err_poweroff;
+
+	ret = genpd_restore_dev(genpd, dev);
+	if (ret)
+		goto err_stop;
 
 	/* Update resume latency value if the measured time exceeds it. */
 	if (timed && runtime_pm) {
@@ -501,6 +508,17 @@ static int pm_genpd_runtime_resume(struct device *dev)
 	}
 
 	return 0;
+
+err_stop:
+	genpd_stop_dev(genpd, dev);
+err_poweroff:
+	if (!dev->power.irq_safe) {
+		mutex_lock(&genpd->lock);
+		genpd_poweroff(genpd, 0);
+		mutex_unlock(&genpd->lock);
+	}
+
+	return ret;
 }
 
 static bool pd_ignore_unused;
@@ -585,6 +603,8 @@ static void pm_genpd_sync_poweroff(struct generic_pm_domain *genpd,
 	    || atomic_read(&genpd->sd_count) > 0)
 		return;
 
+	/* Choose the deepest state when suspending */
+	genpd->state_idx = genpd->state_count - 1;
 	genpd_power_off(genpd, timed);
 
 	genpd->status = GPD_STATE_POWER_OFF;
@@ -1378,7 +1398,7 @@ int pm_genpd_remove_subdomain(struct generic_pm_domain *genpd,
 	mutex_lock(&subdomain->lock);
 	mutex_lock_nested(&genpd->lock, SINGLE_DEPTH_NESTING);
 
-	if (!list_empty(&subdomain->slave_links) || subdomain->device_count) {
+	if (!list_empty(&subdomain->master_links) || subdomain->device_count) {
 		pr_warn("%s: unable to remove subdomain %s\n", genpd->name,
 			subdomain->name);
 		ret = -EBUSY;
@@ -1508,6 +1528,20 @@ void pm_genpd_init(struct generic_pm_domain *genpd,
 		genpd->dev_ops.start = pm_clk_resume;
 	}
 
+	if (genpd->state_idx >= GENPD_MAX_NUM_STATES) {
+		pr_warn("Initial state index out of bounds.\n");
+		genpd->state_idx = GENPD_MAX_NUM_STATES - 1;
+	}
+
+	if (genpd->state_count > GENPD_MAX_NUM_STATES) {
+		pr_warn("Limiting states to  %d\n", GENPD_MAX_NUM_STATES);
+		genpd->state_count = GENPD_MAX_NUM_STATES;
+	}
+
+	/* Use only one "off" state if there were no states declared */
+	if (genpd->state_count == 0)
+		genpd->state_count = 1;
+
 	mutex_lock(&gpd_list_lock);
 	list_add(&genpd->gpd_list_node, &gpd_list);
 	mutex_unlock(&gpd_list_lock);
@@ -1668,6 +1702,9 @@ struct generic_pm_domain *of_genpd_get_from_provider(
 	struct generic_pm_domain *genpd = ERR_PTR(-ENOENT);
 	struct of_genpd_provider *provider;
 
+	if (!genpdspec)
+		return ERR_PTR(-EINVAL);
+
 	mutex_lock(&of_genpd_mutex);
 
 	/* Check if we have such a provider in our array */
@@ -1864,6 +1901,7 @@ static int pm_genpd_summary_one(struct seq_file *s,
 	struct pm_domain_data *pm_data;
 	const char *kobj_path;
 	struct gpd_link *link;
+	char state[16];
 	int ret;
 
 	ret = mutex_lock_interruptible(&genpd->lock);
@@ -1872,7 +1910,13 @@ static int pm_genpd_summary_one(struct seq_file *s,
 
 	if (WARN_ON(genpd->status >= ARRAY_SIZE(status_lookup)))
 		goto exit;
-	seq_printf(s, "%-30s  %-15s ", genpd->name, status_lookup[genpd->status]);
+	if (genpd->status == GPD_STATE_POWER_OFF)
+		snprintf(state, sizeof(state), "%s-%u",
+			 status_lookup[genpd->status], genpd->state_idx);
+	else
+		snprintf(state, sizeof(state), "%s",
+			 status_lookup[genpd->status]);
+	seq_printf(s, "%-30s  %-15s ", genpd->name, state);
 
 	/*
 	 * Modifications on the list require holding locks on both

drivers/base/power/domain_governor.c

@@ -98,7 +98,8 @@ static bool default_stop_ok(struct device *dev)
  *
  * This routine must be executed under the PM domain's lock.
  */
-static bool default_power_down_ok(struct dev_pm_domain *pd)
+static bool __default_power_down_ok(struct dev_pm_domain *pd,
+				     unsigned int state)
 {
 	struct generic_pm_domain *genpd = pd_to_genpd(pd);
 	struct gpd_link *link;
@@ -106,27 +107,9 @@ static bool default_power_down_ok(struct dev_pm_domain *pd)
 	s64 min_off_time_ns;
 	s64 off_on_time_ns;
 
-	if (genpd->max_off_time_changed) {
-		struct gpd_link *link;
+	off_on_time_ns = genpd->states[state].power_off_latency_ns +
+		genpd->states[state].power_on_latency_ns;
 
-		/*
-		 * We have to invalidate the cached results for the masters, so
-		 * use the observation that default_power_down_ok() is not
-		 * going to be called for any master until this instance
-		 * returns.
-		 */
-		list_for_each_entry(link, &genpd->slave_links, slave_node)
-			link->master->max_off_time_changed = true;
-
-		genpd->max_off_time_changed = false;
-		genpd->cached_power_down_ok = false;
-		genpd->max_off_time_ns = -1;
-	} else {
-		return genpd->cached_power_down_ok;
-	}
-
-	off_on_time_ns = genpd->power_off_latency_ns +
-				genpd->power_on_latency_ns;
 
 	min_off_time_ns = -1;
 	/*
@@ -186,8 +169,6 @@ static bool default_power_down_ok(struct dev_pm_domain *pd)
 			min_off_time_ns = constraint_ns;
 	}
 
-	genpd->cached_power_down_ok = true;
-
 	/*
 	 * If the computed minimum device off time is negative, there are no
 	 * latency constraints, so the domain can spend arbitrary time in the
@@ -201,10 +182,45 @@ static bool default_power_down_ok(struct dev_pm_domain *pd)
 	 * time and the time needed to turn the domain on is the maximum
 	 * theoretical time this domain can spend in the "off" state.
 	 */
-	genpd->max_off_time_ns = min_off_time_ns - genpd->power_on_latency_ns;
+	genpd->max_off_time_ns = min_off_time_ns -
+		genpd->states[state].power_on_latency_ns;
 	return true;
 }
 
+static bool default_power_down_ok(struct dev_pm_domain *pd)
+{
+	struct generic_pm_domain *genpd = pd_to_genpd(pd);
+	struct gpd_link *link;
+
+	if (!genpd->max_off_time_changed)
+		return genpd->cached_power_down_ok;
+
+	/*
+	 * We have to invalidate the cached results for the masters, so
+	 * use the observation that default_power_down_ok() is not
+	 * going to be called for any master until this instance
+	 * returns.
+	 */
+	list_for_each_entry(link, &genpd->slave_links, slave_node)
+		link->master->max_off_time_changed = true;
+
+	genpd->max_off_time_ns = -1;
+	genpd->max_off_time_changed = false;
+	genpd->cached_power_down_ok = true;
+	genpd->state_idx = genpd->state_count - 1;
+
+	/* Find a state to power down to, starting from the deepest. */
+	while (!__default_power_down_ok(pd, genpd->state_idx)) {
+		if (genpd->state_idx == 0) {
+			genpd->cached_power_down_ok = false;
+			break;
+		}
+		genpd->state_idx--;
+	}
+
+	return genpd->cached_power_down_ok;
+}
+
 static bool always_on_power_down_ok(struct dev_pm_domain *domain)
 {
 	return false;

drivers/base/power/trace.c

@@ -166,14 +166,14 @@ void generate_pm_trace(const void *tracedata, unsigned int user)
 }
 EXPORT_SYMBOL(generate_pm_trace);
 
-extern char __tracedata_start, __tracedata_end;
+extern char __tracedata_start[], __tracedata_end[];
 static int show_file_hash(unsigned int value)
 {
 	int match;
 	char *tracedata;
 
 	match = 0;
-	for (tracedata = &__tracedata_start ; tracedata < &__tracedata_end ;
+	for (tracedata = __tracedata_start ; tracedata < __tracedata_end ;
 			tracedata += 2 + sizeof(unsigned long)) {
 		unsigned short lineno = *(unsigned short *)tracedata;
 		const char *file = *(const char **)(tracedata + 2);

drivers/cpuidle/governors/menu.c

@@ -199,8 +199,8 @@ static void menu_update(struct cpuidle_driver *drv, struct cpuidle_device *dev);
 static void get_typical_interval(struct menu_device *data)
 {
 	int i, divisor;
-	unsigned int max, thresh;
-	uint64_t avg, stddev;
+	unsigned int max, thresh, avg;
+	uint64_t sum, variance;
 
 	thresh = UINT_MAX; /* Discard outliers above this value */
 
@@ -208,52 +208,51 @@ static void get_typical_interval(struct menu_device *data)
 
 	/* First calculate the average of past intervals */
 	max = 0;
-	avg = 0;
+	sum = 0;
 	divisor = 0;
 	for (i = 0; i < INTERVALS; i++) {
 		unsigned int value = data->intervals[i];
 		if (value <= thresh) {
-			avg += value;
+			sum += value;
 			divisor++;
 			if (value > max)
 				max = value;
 		}
 	}
 	if (divisor == INTERVALS)
-		avg >>= INTERVAL_SHIFT;
+		avg = sum >> INTERVAL_SHIFT;
 	else
-		do_div(avg, divisor);
+		avg = div_u64(sum, divisor);
 
-	/* Then try to determine standard deviation */
-	stddev = 0;
+	/* Then try to determine variance */
+	variance = 0;
 	for (i = 0; i < INTERVALS; i++) {
 		unsigned int value = data->intervals[i];
 		if (value <= thresh) {
-			int64_t diff = value - avg;
-			stddev += diff * diff;
+			int64_t diff = (int64_t)value - avg;
+			variance += diff * diff;
 		}
 	}
 	if (divisor == INTERVALS)
-		stddev >>= INTERVAL_SHIFT;
+		variance >>= INTERVAL_SHIFT;
 	else
-		do_div(stddev, divisor);
+		do_div(variance, divisor);
 
 	/*
-	 * The typical interval is obtained when standard deviation is small
-	 * or standard deviation is small compared to the average interval.
-	 *
-	 * int_sqrt() formal parameter type is unsigned long. When the
-	 * greatest difference to an outlier exceeds ~65 ms * sqrt(divisor)
-	 * the resulting squared standard deviation exceeds the input domain
-	 * of int_sqrt on platforms where unsigned long is 32 bits in size.
-	 * In such case reject the candidate average.
+	 * The typical interval is obtained when standard deviation is
+	 * small (stddev <= 20 us, variance <= 400 us^2) or standard
+	 * deviation is small compared to the average interval (avg >
+	 * 6*stddev, avg^2 > 36*variance). The average is smaller than
+	 * UINT_MAX aka U32_MAX, so computing its square does not
+	 * overflow a u64. We simply reject this candidate average if
+	 * the standard deviation is greater than 715 s (which is
+	 * rather unlikely).
 	 *
 	 * Use this result only if there is no timer to wake us up sooner.
 	 */
-	if (likely(stddev <= ULONG_MAX)) {
-		stddev = int_sqrt(stddev);
-		if (((avg > stddev * 6) && (divisor * 4 >= INTERVALS * 3))
-							|| stddev <= 20) {
+	if (likely(variance <= U64_MAX/36)) {
+		if ((((u64)avg*avg > variance*36) && (divisor * 4 >= INTERVALS * 3))
+							|| variance <= 400) {
 			if (data->next_timer_us > avg)
 				data->predicted_us = avg;
 			return;

include/linux/pm_domain.h

@@ -19,6 +19,8 @@
 /* Defines used for the flags field in the struct generic_pm_domain */
 #define GENPD_FLAG_PM_CLK	(1U << 0) /* PM domain uses PM clk */
 
+#define GENPD_MAX_NUM_STATES	8 /* Number of possible low power states */
+
 enum gpd_status {
 	GPD_STATE_ACTIVE = 0,	/* PM domain is active */
 	GPD_STATE_POWER_OFF,	/* PM domain is off */
@@ -37,6 +39,11 @@ struct gpd_dev_ops {
 	bool (*active_wakeup)(struct device *dev);
 };
 
+struct genpd_power_state {
+	s64 power_off_latency_ns;
+	s64 power_on_latency_ns;
+};
+
 struct generic_pm_domain {
 	struct dev_pm_domain domain;	/* PM domain operations */
 	struct list_head gpd_list_node;	/* Node in the global PM domains list */
@@ -54,9 +61,7 @@ struct generic_pm_domain {
 	unsigned int prepared_count;	/* Suspend counter of prepared devices */
 	bool suspend_power_off;	/* Power status before system suspend */
 	int (*power_off)(struct generic_pm_domain *domain);
-	s64 power_off_latency_ns;
 	int (*power_on)(struct generic_pm_domain *domain);
-	s64 power_on_latency_ns;
 	struct gpd_dev_ops dev_ops;
 	s64 max_off_time_ns;	/* Maximum allowed "suspended" time. */
 	bool max_off_time_changed;
@@ -66,6 +71,10 @@ struct generic_pm_domain {
 	void (*detach_dev)(struct generic_pm_domain *domain,
 			   struct device *dev);
 	unsigned int flags;		/* Bit field of configs for genpd */
+	struct genpd_power_state states[GENPD_MAX_NUM_STATES];
+	unsigned int state_count; /* number of states */
+	unsigned int state_idx; /* state that genpd will go to when off */
+
 };
 
 static inline struct generic_pm_domain *pd_to_genpd(struct dev_pm_domain *pd)

kernel/power/process.c

@@ -30,13 +30,12 @@ static int try_to_freeze_tasks(bool user_only)
 	unsigned long end_time;
 	unsigned int todo;
 	bool wq_busy = false;
-	struct timeval start, end;
-	u64 elapsed_msecs64;
+	ktime_t start, end, elapsed;
 	unsigned int elapsed_msecs;
 	bool wakeup = false;
 	int sleep_usecs = USEC_PER_MSEC;
 
-	do_gettimeofday(&start);
+	start = ktime_get_boottime();
 
 	end_time = jiffies + msecs_to_jiffies(freeze_timeout_msecs);
 
@@ -78,10 +77,9 @@ static int try_to_freeze_tasks(bool user_only)
 			sleep_usecs *= 2;
 	}
 
-	do_gettimeofday(&end);
-	elapsed_msecs64 = timeval_to_ns(&end) - timeval_to_ns(&start);
-	do_div(elapsed_msecs64, NSEC_PER_MSEC);
-	elapsed_msecs = elapsed_msecs64;
+	end = ktime_get_boottime();
+	elapsed = ktime_sub(end, start);
+	elapsed_msecs = ktime_to_ms(elapsed);
 
 	if (todo) {
 		pr_cont("\n");

kernel/power/suspend.c

@@ -248,7 +248,7 @@ static int suspend_test(int level)
 {
 #ifdef CONFIG_PM_DEBUG
 	if (pm_test_level == level) {
-		printk(KERN_INFO "suspend debug: Waiting for %d second(s).\n",
+		pr_info("suspend debug: Waiting for %d second(s).\n",
 				pm_test_delay);
 		mdelay(pm_test_delay * 1000);
 		return 1;
@@ -320,7 +320,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 
 	error = dpm_suspend_late(PMSG_SUSPEND);
 	if (error) {
-		printk(KERN_ERR "PM: late suspend of devices failed\n");
+		pr_err("PM: late suspend of devices failed\n");
 		goto Platform_finish;
 	}
 	error = platform_suspend_prepare_late(state);
@@ -329,7 +329,7 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
 
 	error = dpm_suspend_noirq(PMSG_SUSPEND);
 	if (error) {
-		printk(KERN_ERR "PM: noirq suspend of devices failed\n");
+		pr_err("PM: noirq suspend of devices failed\n");
 		goto Platform_early_resume;
 	}
 	error = platform_suspend_prepare_noirq(state);