X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=kernel%2Ftime%2Fclocksource.c;h=9ed2eec97526546e26c4fb640702a8907b3530a9;hb=e712804ae4bd858bd89272aa3fc1a577294c0940;hp=db0c725de5ea6386395b92c39e4e4aab784e2116;hpb=35c35d1afa8f9afe01d922ff9668a14c5d879b02;p=safe%2Fjmp%2Flinux-2.6

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index db0c725..9ed2eec 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -74,6 +74,8 @@ static struct clocksource *watchdog;
 static struct timer_list watchdog_timer;
 static DEFINE_SPINLOCK(watchdog_lock);
 static cycle_t watchdog_last;
+static unsigned long watchdog_resumed;
+
 /*
  * Interval: 0.5sec Threshold: 0.0625s
  */
@@ -89,7 +91,6 @@ static void clocksource_ratewd(struct clocksource *cs, int64_t delta)
 	       cs->name, delta);
 	cs->flags &= ~(CLOCK_SOURCE_VALID_FOR_HRES | CLOCK_SOURCE_WATCHDOG);
 	clocksource_change_rating(cs, 0);
-	cs->flags &= ~CLOCK_SOURCE_WATCHDOG;
 	list_del(&cs->wd_list);
 }
 
@@ -98,15 +99,24 @@ static void clocksource_watchdog(unsigned long data)
 	struct clocksource *cs, *tmp;
 	cycle_t csnow, wdnow;
 	int64_t wd_nsec, cs_nsec;
+	int resumed;
 
 	spin_lock(&watchdog_lock);
 
+	resumed = test_and_clear_bit(0, &watchdog_resumed);
+
 	wdnow = watchdog->read();
 	wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask);
 	watchdog_last = wdnow;
 
 	list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) {
 		csnow = cs->read();
+
+		if (unlikely(resumed)) {
+			cs->wd_last = csnow;
+			continue;
+		}
+
 		/* Initialized ? */
 		if (!(cs->flags & CLOCK_SOURCE_WATCHDOG)) {
 			if ((cs->flags & CLOCK_SOURCE_IS_CONTINUOUS) &&
@@ -131,11 +141,24 @@ static void clocksource_watchdog(unsigned long data)
 	}
 
 	if (!list_empty(&watchdog_list)) {
-		__mod_timer(&watchdog_timer,
-			    watchdog_timer.expires + WATCHDOG_INTERVAL);
+		/*
+		 * Cycle through CPUs to check if the CPUs stay
+		 * synchronized to each other.
+		 */
+		int next_cpu = next_cpu_nr(raw_smp_processor_id(), cpu_online_map);
+
+		if (next_cpu >= nr_cpu_ids)
+			next_cpu = first_cpu(cpu_online_map);
+		watchdog_timer.expires += WATCHDOG_INTERVAL;
+		add_timer_on(&watchdog_timer, next_cpu);
 	}
 	spin_unlock(&watchdog_lock);
 }
+static void clocksource_resume_watchdog(void)
+{
+	set_bit(0, &watchdog_resumed);
+}
+
 static void clocksource_check_watchdog(struct clocksource *cs)
 {
 	struct clocksource *cse;
@@ -149,7 +172,8 @@ static void clocksource_check_watchdog(struct clocksource *cs)
 		if (!started && watchdog) {
 			watchdog_last = watchdog->read();
 			watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
-			add_timer(&watchdog_timer);
+			add_timer_on(&watchdog_timer,
+				     first_cpu(cpu_online_map));
 		}
 	} else {
 		if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
@@ -170,7 +194,8 @@ static void clocksource_check_watchdog(struct clocksource *cs)
 				watchdog_last = watchdog->read();
 				watchdog_timer.expires =
 					jiffies + WATCHDOG_INTERVAL;
-				add_timer(&watchdog_timer);
+				add_timer_on(&watchdog_timer,
+					     first_cpu(cpu_online_map));
 			}
 		}
 	}
@@ -182,9 +207,43 @@ static void clocksource_check_watchdog(struct clocksource *cs)
 	if (cs->flags & CLOCK_SOURCE_IS_CONTINUOUS)
 		cs->flags |= CLOCK_SOURCE_VALID_FOR_HRES;
 }
+
+static inline void clocksource_resume_watchdog(void) { }
 #endif
 
 /**
+ * clocksource_resume - resume the clocksource(s)
+ */
+void clocksource_resume(void)
+{
+	struct clocksource *cs;
+	unsigned long flags;
+
+	spin_lock_irqsave(&clocksource_lock, flags);
+
+	list_for_each_entry(cs, &clocksource_list, list) {
+		if (cs->resume)
+			cs->resume();
+	}
+
+	clocksource_resume_watchdog();
+
+	spin_unlock_irqrestore(&clocksource_lock, flags);
+}
+
+/**
+ * clocksource_touch_watchdog - Update watchdog
+ *
+ * Update the watchdog after exception contexts such as kgdb so as not
+ * to incorrectly trip the watchdog.
+ *
+ */
+void clocksource_touch_watchdog(void)
+{
+	clocksource_resume_watchdog();
+}
+
+/**
  * clocksource_get_next - Returns the selected clocksource
  *
  */
@@ -266,6 +325,9 @@ int clocksource_register(struct clocksource *c)
 	unsigned long flags;
 	int ret;
 
+	/* save mult_orig on registration */
+	c->mult_orig = c->mult;
+
 	spin_lock_irqsave(&clocksource_lock, flags);
 	ret = clocksource_enqueue(c);
 	if (!ret)
@@ -293,6 +355,21 @@ void clocksource_change_rating(struct clocksource *cs, int rating)
 	spin_unlock_irqrestore(&clocksource_lock, flags);
 }
 
+/**
+ * clocksource_unregister - remove a registered clocksource
+ */
+void clocksource_unregister(struct clocksource *cs)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&clocksource_lock, flags);
+	list_del(&cs->list);
+	if (clocksource_override == cs)
+		clocksource_override = NULL;
+	next_clocksource = select_clocksource();
+	spin_unlock_irqrestore(&clocksource_lock, flags);
+}
+
 #ifdef CONFIG_SYSFS
 /**
  * sysfs_show_current_clocksources - sysfs interface for current clocksource
@@ -302,17 +379,16 @@ void clocksource_change_rating(struct clocksource *cs, int rating)
  * Provides sysfs interface for listing current clocksource.
  */
 static ssize_t
-sysfs_show_current_clocksources(struct sys_device *dev, char *buf)
+sysfs_show_current_clocksources(struct sys_device *dev,
+				struct sysdev_attribute *attr, char *buf)
 {
-	char *curr = buf;
+	ssize_t count = 0;
 
 	spin_lock_irq(&clocksource_lock);
-	curr += sprintf(curr, "%s ", curr_clocksource->name);
+	count = snprintf(buf, PAGE_SIZE, "%s\n", curr_clocksource->name);
 	spin_unlock_irq(&clocksource_lock);
 
-	curr += sprintf(curr, "\n");
-
-	return curr - buf;
+	return count;
 }
 
 /**
@@ -325,10 +401,10 @@ sysfs_show_current_clocksources(struct sys_device *dev, char *buf)
  * clocksource selction.
  */
 static ssize_t sysfs_override_clocksource(struct sys_device *dev,
+					  struct sysdev_attribute *attr,
 					  const char *buf, size_t count)
 {
 	struct clocksource *ovr = NULL;
-	struct list_head *tmp;
 	size_t ret = count;
 	int len;
 
@@ -348,12 +424,11 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
 
 	len = strlen(override_name);
 	if (len) {
+		struct clocksource *cs;
+
 		ovr = clocksource_override;
 		/* try to select it: */
-		list_for_each(tmp, &clocksource_list) {
-			struct clocksource *cs;
-
-			cs = list_entry(tmp, struct clocksource, list);
+		list_for_each_entry(cs, &clocksource_list, list) {
 			if (strlen(cs->name) == len &&
 			    !strcmp(cs->name, override_name))
 				ovr = cs;
@@ -379,36 +454,38 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
  * Provides sysfs interface for listing registered clocksources
  */
 static ssize_t
-sysfs_show_available_clocksources(struct sys_device *dev, char *buf)
+sysfs_show_available_clocksources(struct sys_device *dev,
+				  struct sysdev_attribute *attr,
+				  char *buf)
 {
-	struct list_head *tmp;
-	char *curr = buf;
+	struct clocksource *src;
+	ssize_t count = 0;
 
 	spin_lock_irq(&clocksource_lock);
-	list_for_each(tmp, &clocksource_list) {
-		struct clocksource *src;
-
-		src = list_entry(tmp, struct clocksource, list);
-		curr += sprintf(curr, "%s ", src->name);
+	list_for_each_entry(src, &clocksource_list, list) {
+		count += snprintf(buf + count,
+				  max((ssize_t)PAGE_SIZE - count, (ssize_t)0),
+				  "%s ", src->name);
 	}
 	spin_unlock_irq(&clocksource_lock);
 
-	curr += sprintf(curr, "\n");
+	count += snprintf(buf + count,
+			  max((ssize_t)PAGE_SIZE - count, (ssize_t)0), "\n");
 
-	return curr - buf;
+	return count;
 }
 
 /*
  * Sysfs setup bits:
  */
-static SYSDEV_ATTR(current_clocksource, 0600, sysfs_show_current_clocksources,
+static SYSDEV_ATTR(current_clocksource, 0644, sysfs_show_current_clocksources,
 		   sysfs_override_clocksource);
 
-static SYSDEV_ATTR(available_clocksource, 0600,
+static SYSDEV_ATTR(available_clocksource, 0444,
 		   sysfs_show_available_clocksources, NULL);
 
 static struct sysdev_class clocksource_sysclass = {
-	set_kset_name("clocksource"),
+	.name = "clocksource",
 };
 
 static struct sys_device device_clocksource = {