clocksource: remove redundant code

[sfrench/cifs-2.6.git] / kernel / time / clocksource.c

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 51b6a6a6158cab016aa11b09f0a65c1919c750ec..548c436a776bd35b40b7e9143f24a2743246650b 100644 (file)
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -91,7 +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);
 }
 
@@ -142,8 +141,13 @@ 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(raw_smp_processor_id(), cpu_online_map);
+               if (next_cpu >= NR_CPUS)
+                       next_cpu = first_cpu(cpu_online_map);
+               watchdog_timer.expires += WATCHDOG_INTERVAL;
+               add_timer_on(&watchdog_timer, next_cpu);
        }
        spin_unlock(&watchdog_lock);
 }
@@ -165,7 +169,7 @@ 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)
@@ -175,7 +179,7 @@ static void clocksource_check_watchdog(struct clocksource *cs)
                        if (watchdog)
                                del_timer(&watchdog_timer);
                        watchdog = cs;
-                       init_timer(&watchdog_timer);
+                       init_timer_deferrable(&watchdog_timer);
                        watchdog_timer.function = clocksource_watchdog;
 
                        /* Reset watchdog cycles */
@@ -186,7 +190,8 @@ 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));
                        }
                }
        }
@@ -207,15 +212,12 @@ static inline void clocksource_resume_watchdog(void) { }
  */
 void clocksource_resume(void)
 {
-       struct list_head *tmp;
+       struct clocksource *cs;
        unsigned long flags;
 
        spin_lock_irqsave(&clocksource_lock, flags);
 
-       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 (cs->resume)
                        cs->resume();
        }
@@ -334,6 +336,21 @@ 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
@@ -345,15 +362,13 @@ void clocksource_change_rating(struct clocksource *cs, int rating)
 static ssize_t
 sysfs_show_current_clocksources(struct sys_device *dev, 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;
 }
 
 /**
@@ -369,7 +384,6 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
                                          const char *buf, size_t count)
 {
        struct clocksource *ovr = NULL;
-       struct list_head *tmp;
        size_t ret = count;
        int len;
 
@@ -389,12 +403,11 @@ 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;
@@ -422,21 +435,21 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev,
 static ssize_t
 sysfs_show_available_clocksources(struct sys_device *dev, 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;
 }
 
 /*
@@ -449,7 +462,7 @@ static SYSDEV_ATTR(available_clocksource, 0600,
                   sysfs_show_available_clocksources, NULL);
 
 static struct sysdev_class clocksource_sysclass = {
-       set_kset_name("clocksource"),
+       .name = "clocksource",
 };
 
 static struct sys_device device_clocksource = {