Merge branch 'fujitsu' into release

[karo-tx-linux.git] / kernel / time / timekeeping.c

diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 41579e7fcf9d4110f5ddb381562b6a9270fd3a41..fb0f46fa1ecd0fc09b656e2759ff990372faacb3 100644 (file)
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -154,7 +154,7 @@ __cacheline_aligned_in_smp DEFINE_SEQLOCK(xtime_lock);
  */
 struct timespec xtime __attribute__ ((aligned (16)));
 struct timespec wall_to_monotonic __attribute__ ((aligned (16)));
-static unsigned long total_sleep_time;         /* seconds */
+static struct timespec total_sleep_time;
 
 /*
  * The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock.
@@ -487,17 +487,33 @@ int timekeeping_valid_for_hres(void)
 }
 
 /**
- * read_persistent_clock -  Return time in seconds from the persistent clock.
+ * read_persistent_clock -  Return time from the persistent clock.
  *
  * Weak dummy function for arches that do not yet support it.
- * Returns seconds from epoch using the battery backed persistent clock.
- * Returns zero if unsupported.
+ * Reads the time from the battery backed persistent clock.
+ * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
  *
  *  XXX - Do be sure to remove it once all arches implement it.
  */
-unsigned long __attribute__((weak)) read_persistent_clock(void)
+void __attribute__((weak)) read_persistent_clock(struct timespec *ts)
 {
-       return 0;
+       ts->tv_sec = 0;
+       ts->tv_nsec = 0;
+}
+
+/**
+ * read_boot_clock -  Return time of the system start.
+ *
+ * Weak dummy function for arches that do not yet support it.
+ * Function to read the exact time the system has been started.
+ * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
+ *
+ *  XXX - Do be sure to remove it once all arches implement it.
+ */
+void __attribute__((weak)) read_boot_clock(struct timespec *ts)
+{
+       ts->tv_sec = 0;
+       ts->tv_nsec = 0;
 }
 
 /*
@@ -507,7 +523,10 @@ void __init timekeeping_init(void)
 {
        struct clocksource *clock;
        unsigned long flags;
-       unsigned long sec = read_persistent_clock();
+       struct timespec now, boot;
+
+       read_persistent_clock(&now);
+       read_boot_clock(&boot);
 
        write_seqlock_irqsave(&xtime_lock, flags);
 
@@ -518,19 +537,24 @@ void __init timekeeping_init(void)
                clock->enable(clock);
        timekeeper_setup_internals(clock);
 
-       xtime.tv_sec = sec;
-       xtime.tv_nsec = 0;
+       xtime.tv_sec = now.tv_sec;
+       xtime.tv_nsec = now.tv_nsec;
        raw_time.tv_sec = 0;
        raw_time.tv_nsec = 0;
+       if (boot.tv_sec == 0 && boot.tv_nsec == 0) {
+               boot.tv_sec = xtime.tv_sec;
+               boot.tv_nsec = xtime.tv_nsec;
+       }
        set_normalized_timespec(&wall_to_monotonic,
-               -xtime.tv_sec, -xtime.tv_nsec);
+                               -boot.tv_sec, -boot.tv_nsec);
        update_xtime_cache(0);
-       total_sleep_time = 0;
+       total_sleep_time.tv_sec = 0;
+       total_sleep_time.tv_nsec = 0;
        write_sequnlock_irqrestore(&xtime_lock, flags);
 }
 
 /* time in seconds when suspend began */
-static unsigned long timekeeping_suspend_time;
+static struct timespec timekeeping_suspend_time;
 
 /**
  * timekeeping_resume - Resumes the generic timekeeping subsystem.
@@ -543,18 +567,19 @@ static unsigned long timekeeping_suspend_time;
 static int timekeeping_resume(struct sys_device *dev)
 {
        unsigned long flags;
-       unsigned long now = read_persistent_clock();
+       struct timespec ts;
+
+       read_persistent_clock(&ts);
 
        clocksource_resume();
 
        write_seqlock_irqsave(&xtime_lock, flags);
 
-       if (now && (now > timekeeping_suspend_time)) {
-               unsigned long sleep_length = now - timekeeping_suspend_time;
-
-               xtime.tv_sec += sleep_length;
-               wall_to_monotonic.tv_sec -= sleep_length;
-               total_sleep_time += sleep_length;
+       if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
+               ts = timespec_sub(ts, timekeeping_suspend_time);
+               xtime = timespec_add_safe(xtime, ts);
+               wall_to_monotonic = timespec_sub(wall_to_monotonic, ts);
+               total_sleep_time = timespec_add_safe(total_sleep_time, ts);
        }
        update_xtime_cache(0);
        /* re-base the last cycle value */
@@ -577,7 +602,7 @@ static int timekeeping_suspend(struct sys_device *dev, pm_message_t state)
 {
        unsigned long flags;
 
-       timekeeping_suspend_time = read_persistent_clock();
+       read_persistent_clock(&timekeeping_suspend_time);
 
        write_seqlock_irqsave(&xtime_lock, flags);
        timekeeping_forward_now();
@@ -801,9 +826,12 @@ void update_wall_time(void)
  */
 void getboottime(struct timespec *ts)
 {
-       set_normalized_timespec(ts,
-               - (wall_to_monotonic.tv_sec + total_sleep_time),
-               - wall_to_monotonic.tv_nsec);
+       struct timespec boottime = {
+               .tv_sec = wall_to_monotonic.tv_sec + total_sleep_time.tv_sec,
+               .tv_nsec = wall_to_monotonic.tv_nsec + total_sleep_time.tv_nsec
+       };
+
+       set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
 }
 
 /**
@@ -812,7 +840,7 @@ void getboottime(struct timespec *ts)
  */
 void monotonic_to_bootbased(struct timespec *ts)
 {
-       ts->tv_sec += total_sleep_time;
+       *ts = timespec_add_safe(*ts, total_sleep_time);
 }
 
 unsigned long get_seconds(void)
@@ -821,6 +849,10 @@ unsigned long get_seconds(void)
 }
 EXPORT_SYMBOL(get_seconds);
 
+struct timespec __current_kernel_time(void)
+{
+       return xtime_cache;
+}
 
 struct timespec current_kernel_time(void)
 {
@@ -836,3 +868,20 @@ struct timespec current_kernel_time(void)
        return now;
 }
 EXPORT_SYMBOL(current_kernel_time);
+
+struct timespec get_monotonic_coarse(void)
+{
+       struct timespec now, mono;
+       unsigned long seq;
+
+       do {
+               seq = read_seqbegin(&xtime_lock);
+
+               now = xtime_cache;
+               mono = wall_to_monotonic;
+       } while (read_seqretry(&xtime_lock, seq));
+
+       set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
+                               now.tv_nsec + mono.tv_nsec);
+       return now;
+}