block: cfq: make the io contect sharing lockless

[linux-2.6-omap-h63xx.git] / kernel / time / clocksource.c

diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index fe5c7db2424700f8587284950cf8aecd926c06c6..8d6125ad2cf0cf3c76368e582d9750066d176232 100644 (file)
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -74,15 +74,17 @@ 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 Treshold: 0.0625s
+ * Interval: 0.5sec Threshold: 0.0625s
  */
 #define WATCHDOG_INTERVAL (HZ >> 1)
-#define WATCHDOG_TRESHOLD (NSEC_PER_SEC >> 4)
+#define WATCHDOG_THRESHOLD (NSEC_PER_SEC >> 4)
 
 static void clocksource_ratewd(struct clocksource *cs, int64_t delta)
 {
-       if (delta > -WATCHDOG_TRESHOLD && delta < WATCHDOG_TRESHOLD)
+       if (delta > -WATCHDOG_THRESHOLD && delta < WATCHDOG_THRESHOLD)
                return;
 
        printk(KERN_WARNING "Clocksource %s unstable (delta = %Ld ns)\n",
@@ -98,15 +100,24 @@ 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) &&
@@ -136,6 +147,11 @@ static void clocksource_watchdog(unsigned long data)
        }
        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;
@@ -182,8 +198,30 @@ 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_get_next - Returns the selected clocksource
  *
@@ -328,7 +366,6 @@ 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;
 
@@ -348,12 +385,11 @@ 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;
@@ -381,14 +417,11 @@ 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;
+       struct clocksource *src;
        char *curr = buf;
 
        spin_lock_irq(&clocksource_lock);
-       list_for_each(tmp, &clocksource_list) {
-               struct clocksource *src;
-
-               src = list_entry(tmp, struct clocksource, list);
+       list_for_each_entry(src, &clocksource_list, list) {
                curr += sprintf(curr, "%s ", src->name);
        }
        spin_unlock_irq(&clocksource_lock);
@@ -408,7 +441,7 @@ 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 = {