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Merge tag 'modules-next-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[uclinux-h8/linux.git] / kernel / time / timekeeping.c
index 266dafe..bca3667 100644 (file)
@@ -118,18 +118,6 @@ static inline void tk_update_sleep_time(struct timekeeper *tk, ktime_t delta)
 
 #ifdef CONFIG_DEBUG_TIMEKEEPING
 #define WARNING_FREQ (HZ*300) /* 5 minute rate-limiting */
-/*
- * These simple flag variables are managed
- * without locks, which is racy, but ok since
- * we don't really care about being super
- * precise about how many events were seen,
- * just that a problem was observed.
- */
-static int timekeeping_underflow_seen;
-static int timekeeping_overflow_seen;
-
-/* last_warning is only modified under the timekeeping lock */
-static long timekeeping_last_warning;
 
 static void timekeeping_check_update(struct timekeeper *tk, cycle_t offset)
 {
@@ -149,29 +137,30 @@ static void timekeeping_check_update(struct timekeeper *tk, cycle_t offset)
                }
        }
 
-       if (timekeeping_underflow_seen) {
-               if (jiffies - timekeeping_last_warning > WARNING_FREQ) {
+       if (tk->underflow_seen) {
+               if (jiffies - tk->last_warning > WARNING_FREQ) {
                        printk_deferred("WARNING: Underflow in clocksource '%s' observed, time update ignored.\n", name);
                        printk_deferred("         Please report this, consider using a different clocksource, if possible.\n");
                        printk_deferred("         Your kernel is probably still fine.\n");
-                       timekeeping_last_warning = jiffies;
+                       tk->last_warning = jiffies;
                }
-               timekeeping_underflow_seen = 0;
+               tk->underflow_seen = 0;
        }
 
-       if (timekeeping_overflow_seen) {
-               if (jiffies - timekeeping_last_warning > WARNING_FREQ) {
+       if (tk->overflow_seen) {
+               if (jiffies - tk->last_warning > WARNING_FREQ) {
                        printk_deferred("WARNING: Overflow in clocksource '%s' observed, time update capped.\n", name);
                        printk_deferred("         Please report this, consider using a different clocksource, if possible.\n");
                        printk_deferred("         Your kernel is probably still fine.\n");
-                       timekeeping_last_warning = jiffies;
+                       tk->last_warning = jiffies;
                }
-               timekeeping_overflow_seen = 0;
+               tk->overflow_seen = 0;
        }
 }
 
 static inline cycle_t timekeeping_get_delta(struct tk_read_base *tkr)
 {
+       struct timekeeper *tk = &tk_core.timekeeper;
        cycle_t now, last, mask, max, delta;
        unsigned int seq;
 
@@ -197,13 +186,13 @@ static inline cycle_t timekeeping_get_delta(struct tk_read_base *tkr)
         * mask-relative negative values.
         */
        if (unlikely((~delta & mask) < (mask >> 3))) {
-               timekeeping_underflow_seen = 1;
+               tk->underflow_seen = 1;
                delta = 0;
        }
 
        /* Cap delta value to the max_cycles values to avoid mult overflows */
        if (unlikely(delta > max)) {
-               timekeeping_overflow_seen = 1;
+               tk->overflow_seen = 1;
                delta = tkr->clock->max_cycles;
        }
 
@@ -526,6 +515,17 @@ int pvclock_gtod_unregister_notifier(struct notifier_block *nb)
 EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier);
 
 /*
+ * tk_update_leap_state - helper to update the next_leap_ktime
+ */
+static inline void tk_update_leap_state(struct timekeeper *tk)
+{
+       tk->next_leap_ktime = ntp_get_next_leap();
+       if (tk->next_leap_ktime.tv64 != KTIME_MAX)
+               /* Convert to monotonic time */
+               tk->next_leap_ktime = ktime_sub(tk->next_leap_ktime, tk->offs_real);
+}
+
+/*
  * Update the ktime_t based scalar nsec members of the timekeeper
  */
 static inline void tk_update_ktime_data(struct timekeeper *tk)
@@ -566,17 +566,25 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action)
                ntp_clear();
        }
 
+       tk_update_leap_state(tk);
        tk_update_ktime_data(tk);
 
        update_vsyscall(tk);
        update_pvclock_gtod(tk, action & TK_CLOCK_WAS_SET);
 
+       update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono);
+       update_fast_timekeeper(&tk->tkr_raw,  &tk_fast_raw);
+
+       if (action & TK_CLOCK_WAS_SET)
+               tk->clock_was_set_seq++;
+       /*
+        * The mirroring of the data to the shadow-timekeeper needs
+        * to happen last here to ensure we don't over-write the
+        * timekeeper structure on the next update with stale data
+        */
        if (action & TK_MIRROR)
                memcpy(&shadow_timekeeper, &tk_core.timekeeper,
                       sizeof(tk_core.timekeeper));
-
-       update_fast_timekeeper(&tk->tkr_mono, &tk_fast_mono);
-       update_fast_timekeeper(&tk->tkr_raw,  &tk_fast_raw);
 }
 
 /**
@@ -674,6 +682,23 @@ ktime_t ktime_get(void)
 }
 EXPORT_SYMBOL_GPL(ktime_get);
 
+u32 ktime_get_resolution_ns(void)
+{
+       struct timekeeper *tk = &tk_core.timekeeper;
+       unsigned int seq;
+       u32 nsecs;
+
+       WARN_ON(timekeeping_suspended);
+
+       do {
+               seq = read_seqcount_begin(&tk_core.seq);
+               nsecs = tk->tkr_mono.mult >> tk->tkr_mono.shift;
+       } while (read_seqcount_retry(&tk_core.seq, seq));
+
+       return nsecs;
+}
+EXPORT_SYMBOL_GPL(ktime_get_resolution_ns);
+
 static ktime_t *offsets[TK_OFFS_MAX] = {
        [TK_OFFS_REAL]  = &tk_core.timekeeper.offs_real,
        [TK_OFFS_BOOT]  = &tk_core.timekeeper.offs_boot,
@@ -1154,28 +1179,20 @@ void __weak read_persistent_clock64(struct timespec64 *ts64)
 }
 
 /**
- * read_boot_clock -  Return time of the system start.
+ * read_boot_clock64 -  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.
+ * Returns a timespec64 with tv_sec=0 and tv_nsec=0 if unsupported.
  *
  *  XXX - Do be sure to remove it once all arches implement it.
  */
-void __weak read_boot_clock(struct timespec *ts)
+void __weak read_boot_clock64(struct timespec64 *ts)
 {
        ts->tv_sec = 0;
        ts->tv_nsec = 0;
 }
 
-void __weak read_boot_clock64(struct timespec64 *ts64)
-{
-       struct timespec ts;
-
-       read_boot_clock(&ts);
-       *ts64 = timespec_to_timespec64(ts);
-}
-
 /* Flag for if timekeeping_resume() has injected sleeptime */
 static bool sleeptime_injected;
 
@@ -1811,8 +1828,9 @@ void update_wall_time(void)
         * memcpy under the tk_core.seq against one before we start
         * updating.
         */
+       timekeeping_update(tk, clock_set);
        memcpy(real_tk, tk, sizeof(*tk));
-       timekeeping_update(real_tk, clock_set);
+       /* The memcpy must come last. Do not put anything here! */
        write_seqcount_end(&tk_core.seq);
 out:
        raw_spin_unlock_irqrestore(&timekeeper_lock, flags);
@@ -1901,47 +1919,20 @@ void do_timer(unsigned long ticks)
 }
 
 /**
- * ktime_get_update_offsets_tick - hrtimer helper
- * @offs_real: pointer to storage for monotonic -> realtime offset
- * @offs_boot: pointer to storage for monotonic -> boottime offset
- * @offs_tai:  pointer to storage for monotonic -> clock tai offset
- *
- * Returns monotonic time at last tick and various offsets
- */
-ktime_t ktime_get_update_offsets_tick(ktime_t *offs_real, ktime_t *offs_boot,
-                                                       ktime_t *offs_tai)
-{
-       struct timekeeper *tk = &tk_core.timekeeper;
-       unsigned int seq;
-       ktime_t base;
-       u64 nsecs;
-
-       do {
-               seq = read_seqcount_begin(&tk_core.seq);
-
-               base = tk->tkr_mono.base;
-               nsecs = tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift;
-
-               *offs_real = tk->offs_real;
-               *offs_boot = tk->offs_boot;
-               *offs_tai = tk->offs_tai;
-       } while (read_seqcount_retry(&tk_core.seq, seq));
-
-       return ktime_add_ns(base, nsecs);
-}
-
-#ifdef CONFIG_HIGH_RES_TIMERS
-/**
  * ktime_get_update_offsets_now - hrtimer helper
+ * @cwsseq:    pointer to check and store the clock was set sequence number
  * @offs_real: pointer to storage for monotonic -> realtime offset
  * @offs_boot: pointer to storage for monotonic -> boottime offset
  * @offs_tai:  pointer to storage for monotonic -> clock tai offset
  *
- * Returns current monotonic time and updates the offsets
+ * Returns current monotonic time and updates the offsets if the
+ * sequence number in @cwsseq and timekeeper.clock_was_set_seq are
+ * different.
+ *
  * Called from hrtimer_interrupt() or retrigger_next_event()
  */
-ktime_t ktime_get_update_offsets_now(ktime_t *offs_real, ktime_t *offs_boot,
-                                                       ktime_t *offs_tai)
+ktime_t ktime_get_update_offsets_now(unsigned int *cwsseq, ktime_t *offs_real,
+                                    ktime_t *offs_boot, ktime_t *offs_tai)
 {
        struct timekeeper *tk = &tk_core.timekeeper;
        unsigned int seq;
@@ -1953,15 +1944,23 @@ ktime_t ktime_get_update_offsets_now(ktime_t *offs_real, ktime_t *offs_boot,
 
                base = tk->tkr_mono.base;
                nsecs = timekeeping_get_ns(&tk->tkr_mono);
+               base = ktime_add_ns(base, nsecs);
+
+               if (*cwsseq != tk->clock_was_set_seq) {
+                       *cwsseq = tk->clock_was_set_seq;
+                       *offs_real = tk->offs_real;
+                       *offs_boot = tk->offs_boot;
+                       *offs_tai = tk->offs_tai;
+               }
+
+               /* Handle leapsecond insertion adjustments */
+               if (unlikely(base.tv64 >= tk->next_leap_ktime.tv64))
+                       *offs_real = ktime_sub(tk->offs_real, ktime_set(1, 0));
 
-               *offs_real = tk->offs_real;
-               *offs_boot = tk->offs_boot;
-               *offs_tai = tk->offs_tai;
        } while (read_seqcount_retry(&tk_core.seq, seq));
 
-       return ktime_add_ns(base, nsecs);
+       return base;
 }
-#endif
 
 /**
  * do_adjtimex() - Accessor function to NTP __do_adjtimex function
@@ -2002,6 +2001,8 @@ int do_adjtimex(struct timex *txc)
                __timekeeping_set_tai_offset(tk, tai);
                timekeeping_update(tk, TK_MIRROR | TK_CLOCK_WAS_SET);
        }
+       tk_update_leap_state(tk);
+
        write_seqcount_end(&tk_core.seq);
        raw_spin_unlock_irqrestore(&timekeeper_lock, flags);