timekeeping: Hold timekeepering locks in do_adjtimex and hardpps
[pandora-kernel.git] / kernel / time / timekeeping.c
index 8a84275..d10bd73 100644 (file)
 #include <linux/stop_machine.h>
 #include <linux/pvclock_gtod.h>
 
+#include "tick-internal.h"
+#include "ntp_internal.h"
 
 static struct timekeeper timekeeper;
+static DEFINE_RAW_SPINLOCK(timekeeper_lock);
+static seqcount_t timekeeper_seq;
 
 /* flag for if timekeeping is suspended */
 int __read_mostly timekeeping_suspended;
@@ -67,6 +71,7 @@ static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm)
        tk->wall_to_monotonic = wtm;
        set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
        tk->offs_real = timespec_to_ktime(tmp);
+       tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tk->tai_offset, 0));
 }
 
 static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
@@ -201,8 +206,6 @@ static void update_pvclock_gtod(struct timekeeper *tk)
 
 /**
  * pvclock_gtod_register_notifier - register a pvclock timedata update listener
- *
- * Must hold write on timekeeper.lock
  */
 int pvclock_gtod_register_notifier(struct notifier_block *nb)
 {
@@ -210,11 +213,10 @@ int pvclock_gtod_register_notifier(struct notifier_block *nb)
        unsigned long flags;
        int ret;
 
-       write_seqlock_irqsave(&tk->lock, flags);
+       raw_spin_lock_irqsave(&timekeeper_lock, flags);
        ret = raw_notifier_chain_register(&pvclock_gtod_chain, nb);
-       /* update timekeeping data */
        update_pvclock_gtod(tk);
-       write_sequnlock_irqrestore(&tk->lock, flags);
+       raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
        return ret;
 }
@@ -223,24 +225,21 @@ EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier);
 /**
  * pvclock_gtod_unregister_notifier - unregister a pvclock
  * timedata update listener
- *
- * Must hold write on timekeeper.lock
  */
 int pvclock_gtod_unregister_notifier(struct notifier_block *nb)
 {
-       struct timekeeper *tk = &timekeeper;
        unsigned long flags;
        int ret;
 
-       write_seqlock_irqsave(&tk->lock, flags);
+       raw_spin_lock_irqsave(&timekeeper_lock, flags);
        ret = raw_notifier_chain_unregister(&pvclock_gtod_chain, nb);
-       write_sequnlock_irqrestore(&tk->lock, flags);
+       raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
        return ret;
 }
 EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier);
 
-/* must hold write on timekeeper.lock */
+/* must hold timekeeper_lock */
 static void timekeeping_update(struct timekeeper *tk, bool clearntp)
 {
        if (clearntp) {
@@ -294,12 +293,12 @@ int __getnstimeofday(struct timespec *ts)
        s64 nsecs = 0;
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
 
                ts->tv_sec = tk->xtime_sec;
                nsecs = timekeeping_get_ns(tk);
 
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 
        ts->tv_nsec = 0;
        timespec_add_ns(ts, nsecs);
@@ -335,11 +334,11 @@ ktime_t ktime_get(void)
        WARN_ON(timekeeping_suspended);
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
                secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
                nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec;
 
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
        /*
         * Use ktime_set/ktime_add_ns to create a proper ktime on
         * 32-bit architectures without CONFIG_KTIME_SCALAR.
@@ -366,12 +365,12 @@ void ktime_get_ts(struct timespec *ts)
        WARN_ON(timekeeping_suspended);
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
                ts->tv_sec = tk->xtime_sec;
                nsec = timekeeping_get_ns(tk);
                tomono = tk->wall_to_monotonic;
 
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 
        ts->tv_sec += tomono.tv_sec;
        ts->tv_nsec = 0;
@@ -395,12 +394,12 @@ void timekeeping_clocktai(struct timespec *ts)
        WARN_ON(timekeeping_suspended);
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
 
                ts->tv_sec = tk->xtime_sec + tk->tai_offset;
                nsecs = timekeeping_get_ns(tk);
 
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 
        ts->tv_nsec = 0;
        timespec_add_ns(ts, nsecs);
@@ -409,6 +408,20 @@ void timekeeping_clocktai(struct timespec *ts)
 EXPORT_SYMBOL(timekeeping_clocktai);
 
 
+/**
+ * ktime_get_clocktai - Returns the TAI time of day in a ktime
+ *
+ * Returns the time of day in a ktime.
+ */
+ktime_t ktime_get_clocktai(void)
+{
+       struct timespec ts;
+
+       timekeeping_clocktai(&ts);
+       return timespec_to_ktime(ts);
+}
+EXPORT_SYMBOL(ktime_get_clocktai);
+
 #ifdef CONFIG_NTP_PPS
 
 /**
@@ -429,7 +442,7 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
        WARN_ON_ONCE(timekeeping_suspended);
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
 
                *ts_raw = tk->raw_time;
                ts_real->tv_sec = tk->xtime_sec;
@@ -438,7 +451,7 @@ void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
                nsecs_raw = timekeeping_get_ns_raw(tk);
                nsecs_real = timekeeping_get_ns(tk);
 
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 
        timespec_add_ns(ts_raw, nsecs_raw);
        timespec_add_ns(ts_real, nsecs_real);
@@ -478,7 +491,8 @@ int do_settimeofday(const struct timespec *tv)
        if (!timespec_valid_strict(tv))
                return -EINVAL;
 
-       write_seqlock_irqsave(&tk->lock, flags);
+       raw_spin_lock_irqsave(&timekeeper_lock, flags);
+       write_seqcount_begin(&timekeeper_seq);
 
        timekeeping_forward_now(tk);
 
@@ -492,7 +506,8 @@ int do_settimeofday(const struct timespec *tv)
 
        timekeeping_update(tk, true);
 
-       write_sequnlock_irqrestore(&tk->lock, flags);
+       write_seqcount_end(&timekeeper_seq);
+       raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
        /* signal hrtimers about time change */
        clock_was_set();
@@ -517,7 +532,8 @@ int timekeeping_inject_offset(struct timespec *ts)
        if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
                return -EINVAL;
 
-       write_seqlock_irqsave(&tk->lock, flags);
+       raw_spin_lock_irqsave(&timekeeper_lock, flags);
+       write_seqcount_begin(&timekeeper_seq);
 
        timekeeping_forward_now(tk);
 
@@ -534,7 +550,8 @@ int timekeeping_inject_offset(struct timespec *ts)
 error: /* even if we error out, we forwarded the time, so call update */
        timekeeping_update(tk, true);
 
-       write_sequnlock_irqrestore(&tk->lock, flags);
+       write_seqcount_end(&timekeeper_seq);
+       raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
        /* signal hrtimers about time change */
        clock_was_set();
@@ -555,9 +572,9 @@ s32 timekeeping_get_tai_offset(void)
        s32 ret;
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
                ret = tk->tai_offset;
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 
        return ret;
 }
@@ -566,9 +583,10 @@ s32 timekeeping_get_tai_offset(void)
  * __timekeeping_set_tai_offset - Lock free worker function
  *
  */
-void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
+static void __timekeeping_set_tai_offset(struct timekeeper *tk, s32 tai_offset)
 {
        tk->tai_offset = tai_offset;
+       tk->offs_tai = ktime_sub(tk->offs_real, ktime_set(tai_offset, 0));
 }
 
 /**
@@ -580,9 +598,11 @@ void timekeeping_set_tai_offset(s32 tai_offset)
        struct timekeeper *tk = &timekeeper;
        unsigned long flags;
 
-       write_seqlock_irqsave(&tk->lock, flags);
+       raw_spin_lock_irqsave(&timekeeper_lock, flags);
+       write_seqcount_begin(&timekeeper_seq);
        __timekeeping_set_tai_offset(tk, tai_offset);
-       write_sequnlock_irqrestore(&tk->lock, flags);
+       write_seqcount_end(&timekeeper_seq);
+       raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 }
 
 /**
@@ -598,7 +618,8 @@ static int change_clocksource(void *data)
 
        new = (struct clocksource *) data;
 
-       write_seqlock_irqsave(&tk->lock, flags);
+       raw_spin_lock_irqsave(&timekeeper_lock, flags);
+       write_seqcount_begin(&timekeeper_seq);
 
        timekeeping_forward_now(tk);
        if (!new->enable || new->enable(new) == 0) {
@@ -609,7 +630,8 @@ static int change_clocksource(void *data)
        }
        timekeeping_update(tk, true);
 
-       write_sequnlock_irqrestore(&tk->lock, flags);
+       write_seqcount_end(&timekeeper_seq);
+       raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
        return 0;
 }
@@ -659,11 +681,11 @@ void getrawmonotonic(struct timespec *ts)
        s64 nsecs;
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
                nsecs = timekeeping_get_ns_raw(tk);
                *ts = tk->raw_time;
 
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 
        timespec_add_ns(ts, nsecs);
 }
@@ -679,11 +701,11 @@ int timekeeping_valid_for_hres(void)
        int ret;
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
 
                ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
 
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 
        return ret;
 }
@@ -698,11 +720,11 @@ u64 timekeeping_max_deferment(void)
        u64 ret;
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
 
                ret = tk->clock->max_idle_ns;
 
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 
        return ret;
 }
@@ -765,11 +787,10 @@ void __init timekeeping_init(void)
                boot.tv_nsec = 0;
        }
 
-       seqlock_init(&tk->lock);
-
+       raw_spin_lock_irqsave(&timekeeper_lock, flags);
+       write_seqcount_begin(&timekeeper_seq);
        ntp_init();
 
-       write_seqlock_irqsave(&tk->lock, flags);
        clock = clocksource_default_clock();
        if (clock->enable)
                clock->enable(clock);
@@ -788,7 +809,8 @@ void __init timekeeping_init(void)
        tmp.tv_nsec = 0;
        tk_set_sleep_time(tk, tmp);
 
-       write_sequnlock_irqrestore(&tk->lock, flags);
+       write_seqcount_end(&timekeeper_seq);
+       raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 }
 
 /* time in seconds when suspend began */
@@ -836,7 +858,8 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
        if (has_persistent_clock())
                return;
 
-       write_seqlock_irqsave(&tk->lock, flags);
+       raw_spin_lock_irqsave(&timekeeper_lock, flags);
+       write_seqcount_begin(&timekeeper_seq);
 
        timekeeping_forward_now(tk);
 
@@ -844,7 +867,8 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
 
        timekeeping_update(tk, true);
 
-       write_sequnlock_irqrestore(&tk->lock, flags);
+       write_seqcount_end(&timekeeper_seq);
+       raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
        /* signal hrtimers about time change */
        clock_was_set();
@@ -871,7 +895,8 @@ static void timekeeping_resume(void)
        clockevents_resume();
        clocksource_resume();
 
-       write_seqlock_irqsave(&tk->lock, flags);
+       raw_spin_lock_irqsave(&timekeeper_lock, flags);
+       write_seqcount_begin(&timekeeper_seq);
 
        /*
         * After system resumes, we need to calculate the suspended time and
@@ -923,7 +948,8 @@ static void timekeeping_resume(void)
        tk->ntp_error = 0;
        timekeeping_suspended = 0;
        timekeeping_update(tk, false);
-       write_sequnlock_irqrestore(&tk->lock, flags);
+       write_seqcount_end(&timekeeper_seq);
+       raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
        touch_softlockup_watchdog();
 
@@ -942,7 +968,8 @@ static int timekeeping_suspend(void)
 
        read_persistent_clock(&timekeeping_suspend_time);
 
-       write_seqlock_irqsave(&tk->lock, flags);
+       raw_spin_lock_irqsave(&timekeeper_lock, flags);
+       write_seqcount_begin(&timekeeper_seq);
        timekeeping_forward_now(tk);
        timekeeping_suspended = 1;
 
@@ -965,7 +992,8 @@ static int timekeeping_suspend(void)
                timekeeping_suspend_time =
                        timespec_add(timekeeping_suspend_time, delta_delta);
        }
-       write_sequnlock_irqrestore(&tk->lock, flags);
+       write_seqcount_end(&timekeeper_seq);
+       raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
        clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
        clocksource_suspend();
@@ -1234,15 +1262,16 @@ static inline void accumulate_nsecs_to_secs(struct timekeeper *tk)
 static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
                                                u32 shift)
 {
+       cycle_t interval = tk->cycle_interval << shift;
        u64 raw_nsecs;
 
        /* If the offset is smaller then a shifted interval, do nothing */
-       if (offset < tk->cycle_interval<<shift)
+       if (offset < interval)
                return offset;
 
        /* Accumulate one shifted interval */
-       offset -= tk->cycle_interval << shift;
-       tk->clock->cycle_last += tk->cycle_interval << shift;
+       offset -= interval;
+       tk->clock->cycle_last += interval;
 
        tk->xtime_nsec += tk->xtime_interval << shift;
        accumulate_nsecs_to_secs(tk);
@@ -1304,7 +1333,8 @@ static void update_wall_time(void)
        int shift = 0, maxshift;
        unsigned long flags;
 
-       write_seqlock_irqsave(&tk->lock, flags);
+       raw_spin_lock_irqsave(&timekeeper_lock, flags);
+       write_seqcount_begin(&timekeeper_seq);
 
        /* Make sure we're fully resumed: */
        if (unlikely(timekeeping_suspended))
@@ -1359,7 +1389,8 @@ static void update_wall_time(void)
        timekeeping_update(tk, false);
 
 out:
-       write_sequnlock_irqrestore(&tk->lock, flags);
+       write_seqcount_end(&timekeeper_seq);
+       raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
 
 }
 
@@ -1407,13 +1438,13 @@ void get_monotonic_boottime(struct timespec *ts)
        WARN_ON(timekeeping_suspended);
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
                ts->tv_sec = tk->xtime_sec;
                nsec = timekeeping_get_ns(tk);
                tomono = tk->wall_to_monotonic;
                sleep = tk->total_sleep_time;
 
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 
        ts->tv_sec += tomono.tv_sec + sleep.tv_sec;
        ts->tv_nsec = 0;
@@ -1472,10 +1503,10 @@ struct timespec current_kernel_time(void)
        unsigned long seq;
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
 
                now = tk_xtime(tk);
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 
        return now;
 }
@@ -1488,11 +1519,11 @@ struct timespec get_monotonic_coarse(void)
        unsigned long seq;
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
 
                now = tk_xtime(tk);
                mono = tk->wall_to_monotonic;
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 
        set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
                                now.tv_nsec + mono.tv_nsec);
@@ -1523,11 +1554,11 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
        unsigned long seq;
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
                *xtim = tk_xtime(tk);
                *wtom = tk->wall_to_monotonic;
                *sleep = tk->total_sleep_time;
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 }
 
 #ifdef CONFIG_HIGH_RES_TIMERS
@@ -1539,7 +1570,8 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
  * Returns current monotonic time and updates the offsets
  * Called from hrtimer_interupt() or retrigger_next_event()
  */
-ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
+ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot,
+                                                       ktime_t *offs_tai)
 {
        struct timekeeper *tk = &timekeeper;
        ktime_t now;
@@ -1547,14 +1579,15 @@ ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
        u64 secs, nsecs;
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
 
                secs = tk->xtime_sec;
                nsecs = timekeeping_get_ns(tk);
 
                *offs_real = tk->offs_real;
                *offs_boot = tk->offs_boot;
-       } while (read_seqretry(&tk->lock, seq));
+               *offs_tai = tk->offs_tai;
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 
        now = ktime_add_ns(ktime_set(secs, 0), nsecs);
        now = ktime_sub(now, *offs_real);
@@ -1572,14 +1605,76 @@ ktime_t ktime_get_monotonic_offset(void)
        struct timespec wtom;
 
        do {
-               seq = read_seqbegin(&tk->lock);
+               seq = read_seqcount_begin(&timekeeper_seq);
                wtom = tk->wall_to_monotonic;
-       } while (read_seqretry(&tk->lock, seq));
+       } while (read_seqcount_retry(&timekeeper_seq, seq));
 
        return timespec_to_ktime(wtom);
 }
 EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset);
 
+/**
+ * do_adjtimex() - Accessor function to NTP __do_adjtimex function
+ */
+int do_adjtimex(struct timex *txc)
+{
+       unsigned long flags;
+       struct timespec ts;
+       s32 tai, orig_tai;
+       int ret;
+
+       /* Validate the data before disabling interrupts */
+       ret = ntp_validate_timex(txc);
+       if (ret)
+               return ret;
+
+       if (txc->modes & ADJ_SETOFFSET) {
+               struct timespec delta;
+               delta.tv_sec  = txc->time.tv_sec;
+               delta.tv_nsec = txc->time.tv_usec;
+               if (!(txc->modes & ADJ_NANO))
+                       delta.tv_nsec *= 1000;
+               ret = timekeeping_inject_offset(&delta);
+               if (ret)
+                       return ret;
+       }
+
+       getnstimeofday(&ts);
+       orig_tai = tai = timekeeping_get_tai_offset();
+
+       raw_spin_lock_irqsave(&timekeeper_lock, flags);
+       write_seqcount_begin(&timekeeper_seq);
+
+       ret = __do_adjtimex(txc, &ts, &tai);
+
+       write_seqcount_end(&timekeeper_seq);
+       raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+
+       if (tai != orig_tai)
+               timekeeping_set_tai_offset(tai);
+
+       return ret;
+}
+
+#ifdef CONFIG_NTP_PPS
+/**
+ * hardpps() - Accessor function to NTP __hardpps function
+ */
+void hardpps(const struct timespec *phase_ts, const struct timespec *raw_ts)
+{
+       unsigned long flags;
+
+       raw_spin_lock_irqsave(&timekeeper_lock, flags);
+       write_seqcount_begin(&timekeeper_seq);
+
+       __hardpps(phase_ts, raw_ts);
+
+       write_seqcount_end(&timekeeper_seq);
+       raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
+}
+EXPORT_SYMBOL(hardpps);
+#endif
+
 /**
  * xtime_update() - advances the timekeeping infrastructure
  * @ticks:     number of ticks, that have elapsed since the last call.