Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Ingo Molnar:
 "The main changes in this cycle were:

   - rework hrtimer expiry calculation in hrtimer_interrupt(): the
     previous code had a subtle bug where expiry caching would miss an
     expiry, resulting in occasional bogus (late) expiry of hrtimers.

   - continuing Y2038 fixes

   - ktime division optimization

   - misc smaller fixes and cleanups"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  hrtimer: Make __hrtimer_get_next_event() static
  rtc: Convert rtc_set_ntp_time() to use timespec64
  rtc: Remove redundant rtc_valid_tm() from rtc_hctosys()
  rtc: Modify rtc_hctosys() to address y2038 issues
  rtc: Update rtc-dev to use y2038-safe time interfaces
  rtc: Update interface.c to use y2038-safe time interfaces
  time: Expose get_monotonic_boottime64 for in-kernel use
  time: Expose getboottime64 for in-kernel uses
  ktime: Optimize ktime_divns for constant divisors
  hrtimer: Prevent stale expiry time in hrtimer_interrupt()
  ktime.h: Introduce ktime_ms_delta

drivers/rtc/hctosys.c

@@ -26,7 +26,7 @@ static int __init rtc_hctosys(void)
 {
 	int err = -ENODEV;
 	struct rtc_time tm;
-	struct timespec tv = {
+	struct timespec64 tv64 = {
 		.tv_nsec = NSEC_PER_SEC >> 1,
 	};
 	struct rtc_device *rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
@@ -45,25 +45,17 @@ static int __init rtc_hctosys(void)
 
 	}
 
-	err = rtc_valid_tm(&tm);
-	if (err) {
-		dev_err(rtc->dev.parent,
-			"hctosys: invalid date/time\n");
-		goto err_invalid;
-	}
-
-	rtc_tm_to_time(&tm, &tv.tv_sec);
+	tv64.tv_sec = rtc_tm_to_time64(&tm);
 
-	err = do_settimeofday(&tv);
+	err = do_settimeofday64(&tv64);
 
 	dev_info(rtc->dev.parent,
 		"setting system clock to "
-		"%d-%02d-%02d %02d:%02d:%02d UTC (%u)\n",
+		"%d-%02d-%02d %02d:%02d:%02d UTC (%lld)\n",
 		tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
 		tm.tm_hour, tm.tm_min, tm.tm_sec,
-		(unsigned int) tv.tv_sec);
+		(long long) tv64.tv_sec);
 
-err_invalid:
 err_read:
 	rtc_class_close(rtc);
 

drivers/rtc/interface.c

@@ -73,10 +73,8 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
 	else if (rtc->ops->set_time)
 		err = rtc->ops->set_time(rtc->dev.parent, tm);
 	else if (rtc->ops->set_mmss) {
-		unsigned long secs;
-		err = rtc_tm_to_time(tm, &secs);
-		if (err == 0)
-			err = rtc->ops->set_mmss(rtc->dev.parent, secs);
+		time64_t secs64 = rtc_tm_to_time64(tm);
+		err = rtc->ops->set_mmss(rtc->dev.parent, secs64);
 	} else
 		err = -EINVAL;
 
@@ -105,7 +103,7 @@ int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)
 
 		err = rtc->ops->read_time(rtc->dev.parent, &old);
 		if (err == 0) {
-			rtc_time_to_tm(secs, &new);
+			rtc_time64_to_tm(secs, &new);
 
 			/*
 			 * avoid writing when we're going to change the day of
@@ -157,7 +155,7 @@ int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 	int err;
 	struct rtc_time before, now;
 	int first_time = 1;
-	unsigned long t_now, t_alm;
+	time64_t t_now, t_alm;
 	enum { none, day, month, year } missing = none;
 	unsigned days;
 
@@ -258,8 +256,8 @@ int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 	}
 
 	/* with luck, no rollover is needed */
-	rtc_tm_to_time(&now, &t_now);
-	rtc_tm_to_time(&alarm->time, &t_alm);
+	t_now = rtc_tm_to_time64(&now);
+	t_alm = rtc_tm_to_time64(&alarm->time);
 	if (t_now < t_alm)
 		goto done;
 
@@ -273,7 +271,7 @@ int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 	case day:
 		dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
 		t_alm += 24 * 60 * 60;
-		rtc_time_to_tm(t_alm, &alarm->time);
+		rtc_time64_to_tm(t_alm, &alarm->time);
 		break;
 
 	/* Month rollover ... if it's the 31th, an alarm on the 3rd will
@@ -346,19 +344,19 @@ EXPORT_SYMBOL_GPL(rtc_read_alarm);
 static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
 {
 	struct rtc_time tm;
-	long now, scheduled;
+	time64_t now, scheduled;
 	int err;
 
 	err = rtc_valid_tm(&alarm->time);
 	if (err)
 		return err;
-	rtc_tm_to_time(&alarm->time, &scheduled);
+	scheduled = rtc_tm_to_time64(&alarm->time);
 
 	/* Make sure we're not setting alarms in the past */
 	err = __rtc_read_time(rtc, &tm);
 	if (err)
 		return err;
-	rtc_tm_to_time(&tm, &now);
+	now = rtc_tm_to_time64(&tm);
 	if (scheduled <= now)
 		return -ETIME;
 	/*

drivers/rtc/rtc-dev.c

@@ -304,12 +304,12 @@ static long rtc_dev_ioctl(struct file *file,
 		 * Not supported here.
 		 */
 		{
-			unsigned long now, then;
+			time64_t now, then;
 
 			err = rtc_read_time(rtc, &tm);
 			if (err < 0)
 				return err;
-			rtc_tm_to_time(&tm, &now);
+			now = rtc_tm_to_time64(&tm);
 
 			alarm.time.tm_mday = tm.tm_mday;
 			alarm.time.tm_mon = tm.tm_mon;
@@ -317,11 +317,11 @@ static long rtc_dev_ioctl(struct file *file,
 			err  = rtc_valid_tm(&alarm.time);
 			if (err < 0)
 				return err;
-			rtc_tm_to_time(&alarm.time, &then);
+			then = rtc_tm_to_time64(&alarm.time);
 
 			/* alarm may need to wrap into tomorrow */
 			if (then < now) {
-				rtc_time_to_tm(now + 24 * 60 * 60, &tm);
+				rtc_time64_to_tm(now + 24 * 60 * 60, &tm);
 				alarm.time.tm_mday = tm.tm_mday;
 				alarm.time.tm_mon = tm.tm_mon;
 				alarm.time.tm_year = tm.tm_year;

drivers/rtc/systohc.c

@@ -20,16 +20,16 @@
  *
  * If temporary failure is indicated the caller should try again 'soon'
  */
-int rtc_set_ntp_time(struct timespec now)
+int rtc_set_ntp_time(struct timespec64 now)
 {
 	struct rtc_device *rtc;
 	struct rtc_time tm;
 	int err = -ENODEV;
 
 	if (now.tv_nsec < (NSEC_PER_SEC >> 1))
-		rtc_time_to_tm(now.tv_sec, &tm);
+		rtc_time64_to_tm(now.tv_sec, &tm);
 	else
-		rtc_time_to_tm(now.tv_sec + 1, &tm);
+		rtc_time64_to_tm(now.tv_sec + 1, &tm);
 
 	rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
 	if (rtc) {

include/linux/hrtimer.h

@@ -170,6 +170,7 @@ enum  hrtimer_base_type {
  * @clock_was_set:	Indicates that clock was set from irq context.
  * @expires_next:	absolute time of the next event which was scheduled
  *			via clock_set_next_event()
+ * @in_hrtirq:		hrtimer_interrupt() is currently executing
  * @hres_active:	State of high resolution mode
  * @hang_detected:	The last hrtimer interrupt detected a hang
  * @nr_events:		Total number of hrtimer interrupt events
@@ -185,6 +186,7 @@ struct hrtimer_cpu_base {
 	unsigned int			clock_was_set;
 #ifdef CONFIG_HIGH_RES_TIMERS
 	ktime_t				expires_next;
+	int				in_hrtirq;
 	int				hres_active;
 	int				hang_detected;
 	unsigned long			nr_events;

include/linux/ktime.h

@@ -166,7 +166,17 @@ static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2)
 }
 
 #if BITS_PER_LONG < 64
-extern u64 ktime_divns(const ktime_t kt, s64 div);
+extern u64 __ktime_divns(const ktime_t kt, s64 div);
+static inline u64 ktime_divns(const ktime_t kt, s64 div)
+{
+	if (__builtin_constant_p(div) && !(div >> 32)) {
+		u64 ns = kt.tv64;
+		do_div(ns, div);
+		return ns;
+	} else {
+		return __ktime_divns(kt, div);
+	}
+}
 #else /* BITS_PER_LONG < 64 */
 # define ktime_divns(kt, div)		(u64)((kt).tv64 / (div))
 #endif
@@ -186,6 +196,11 @@ static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier)
        return ktime_to_us(ktime_sub(later, earlier));
 }
 
+static inline s64 ktime_ms_delta(const ktime_t later, const ktime_t earlier)
+{
+	return ktime_to_ms(ktime_sub(later, earlier));
+}
+
 static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec)
 {
 	return ktime_add_ns(kt, usec * NSEC_PER_USEC);

include/linux/rtc.h

@@ -161,7 +161,7 @@ extern void devm_rtc_device_unregister(struct device *dev,
 extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
 extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
 extern int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs);
-extern int rtc_set_ntp_time(struct timespec now);
+extern int rtc_set_ntp_time(struct timespec64 now);
 int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
 extern int rtc_read_alarm(struct rtc_device *rtc,
 			struct rtc_wkalrm *alrm);

include/linux/timekeeping.h

@@ -33,6 +33,7 @@ extern time64_t ktime_get_real_seconds(void);
 
 extern int __getnstimeofday64(struct timespec64 *tv);
 extern void getnstimeofday64(struct timespec64 *tv);
+extern void getboottime64(struct timespec64 *ts);
 
 #if BITS_PER_LONG == 64
 /**
@@ -72,6 +73,11 @@ static inline struct timespec get_monotonic_coarse(void)
 {
 	return get_monotonic_coarse64();
 }
+
+static inline void getboottime(struct timespec *ts)
+{
+	return getboottime64(ts);
+}
 #else
 /**
  * Deprecated. Use do_settimeofday64().
@@ -129,9 +135,15 @@ static inline struct timespec get_monotonic_coarse(void)
 {
 	return timespec64_to_timespec(get_monotonic_coarse64());
 }
-#endif
 
-extern void getboottime(struct timespec *ts);
+static inline void getboottime(struct timespec *ts)
+{
+	struct timespec64 ts64;
+
+	getboottime64(&ts64);
+	*ts = timespec64_to_timespec(ts64);
+}
+#endif
 
 #define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
 #define ktime_get_real_ts64(ts)	getnstimeofday64(ts)
@@ -217,6 +229,11 @@ static inline void get_monotonic_boottime(struct timespec *ts)
 	*ts = ktime_to_timespec(ktime_get_boottime());
 }
 
+static inline void get_monotonic_boottime64(struct timespec64 *ts)
+{
+	*ts = ktime_to_timespec64(ktime_get_boottime());
+}
+
 static inline void timekeeping_clocktai(struct timespec *ts)
 {
 	*ts = ktime_to_timespec(ktime_get_clocktai());

kernel/time/hrtimer.c

@@ -266,7 +266,7 @@ lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
 /*
  * Divide a ktime value by a nanosecond value
  */
-u64 ktime_divns(const ktime_t kt, s64 div)
+u64 __ktime_divns(const ktime_t kt, s64 div)
 {
 	u64 dclc;
 	int sft = 0;
@@ -282,7 +282,7 @@ u64 ktime_divns(const ktime_t kt, s64 div)
 
 	return dclc;
 }
-EXPORT_SYMBOL_GPL(ktime_divns);
+EXPORT_SYMBOL_GPL(__ktime_divns);
 #endif /* BITS_PER_LONG >= 64 */
 
 /*
@@ -440,6 +440,37 @@ static inline void debug_deactivate(struct hrtimer *timer)
 	trace_hrtimer_cancel(timer);
 }
 
+#if defined(CONFIG_NO_HZ_COMMON) || defined(CONFIG_HIGH_RES_TIMERS)
+static ktime_t __hrtimer_get_next_event(struct hrtimer_cpu_base *cpu_base)
+{
+	struct hrtimer_clock_base *base = cpu_base->clock_base;
+	ktime_t expires, expires_next = { .tv64 = KTIME_MAX };
+	int i;
+
+	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
+		struct timerqueue_node *next;
+		struct hrtimer *timer;
+
+		next = timerqueue_getnext(&base->active);
+		if (!next)
+			continue;
+
+		timer = container_of(next, struct hrtimer, node);
+		expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
+		if (expires.tv64 < expires_next.tv64)
+			expires_next = expires;
+	}
+	/*
+	 * clock_was_set() might have changed base->offset of any of
+	 * the clock bases so the result might be negative. Fix it up
+	 * to prevent a false positive in clockevents_program_event().
+	 */
+	if (expires_next.tv64 < 0)
+		expires_next.tv64 = 0;
+	return expires_next;
+}
+#endif
+
 /* High resolution timer related functions */
 #ifdef CONFIG_HIGH_RES_TIMERS
 
@@ -488,32 +519,7 @@ static inline int hrtimer_hres_active(void)
 static void
 hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal)
 {
-	int i;
-	struct hrtimer_clock_base *base = cpu_base->clock_base;
-	ktime_t expires, expires_next;
-
-	expires_next.tv64 = KTIME_MAX;
-
-	for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
-		struct hrtimer *timer;
-		struct timerqueue_node *next;
-
-		next = timerqueue_getnext(&base->active);
-		if (!next)
-			continue;
-		timer = container_of(next, struct hrtimer, node);
-
-		expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
-		/*
-		 * clock_was_set() has changed base->offset so the
-		 * result might be negative. Fix it up to prevent a
-		 * false positive in clockevents_program_event()
-		 */
-		if (expires.tv64 < 0)
-			expires.tv64 = 0;
-		if (expires.tv64 < expires_next.tv64)
-			expires_next = expires;
-	}
+	ktime_t expires_next = __hrtimer_get_next_event(cpu_base);
 
 	if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64)
 		return;
@@ -586,6 +592,15 @@ static int hrtimer_reprogram(struct hrtimer *timer,
 	if (expires.tv64 >= cpu_base->expires_next.tv64)
 		return 0;
 
+	/*
+	 * When the target cpu of the timer is currently executing
+	 * hrtimer_interrupt(), then we do not touch the clock event
+	 * device. hrtimer_interrupt() will reevaluate all clock bases
+	 * before reprogramming the device.
+	 */
+	if (cpu_base->in_hrtirq)
+		return 0;
+
 	/*
 	 * If a hang was detected in the last timer interrupt then we
 	 * do not schedule a timer which is earlier than the expiry
@@ -1104,29 +1119,14 @@ EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
 ktime_t hrtimer_get_next_event(void)
 {
 	struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
-	struct hrtimer_clock_base *base = cpu_base->clock_base;
-	ktime_t delta, mindelta = { .tv64 = KTIME_MAX };
+	ktime_t mindelta = { .tv64 = KTIME_MAX };
 	unsigned long flags;
-	int i;
 
 	raw_spin_lock_irqsave(&cpu_base->lock, flags);
 
-	if (!hrtimer_hres_active()) {
-		for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
-			struct hrtimer *timer;
-			struct timerqueue_node *next;
-
-			next = timerqueue_getnext(&base->active);
-			if (!next)
-				continue;
-
-			timer = container_of(next, struct hrtimer, node);
-			delta.tv64 = hrtimer_get_expires_tv64(timer);
-			delta = ktime_sub(delta, base->get_time());
-			if (delta.tv64 < mindelta.tv64)
-				mindelta.tv64 = delta.tv64;
-		}
-	}
+	if (!hrtimer_hres_active())
+		mindelta = ktime_sub(__hrtimer_get_next_event(cpu_base),
+				     ktime_get());
 
 	raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
 
@@ -1253,7 +1253,7 @@ void hrtimer_interrupt(struct clock_event_device *dev)
 	raw_spin_lock(&cpu_base->lock);
 	entry_time = now = hrtimer_update_base(cpu_base);
 retry:
-	expires_next.tv64 = KTIME_MAX;
+	cpu_base->in_hrtirq = 1;
 	/*
 	 * We set expires_next to KTIME_MAX here with cpu_base->lock
 	 * held to prevent that a timer is enqueued in our queue via
@@ -1291,28 +1291,20 @@ void hrtimer_interrupt(struct clock_event_device *dev)
 			 * are right-of a not yet expired timer, because that
 			 * timer will have to trigger a wakeup anyway.
 			 */
-
-			if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer)) {
-				ktime_t expires;
-
-				expires = ktime_sub(hrtimer_get_expires(timer),
-						    base->offset);
-				if (expires.tv64 < 0)
-					expires.tv64 = KTIME_MAX;
-				if (expires.tv64 < expires_next.tv64)
-					expires_next = expires;
+			if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer))
 				break;
-			}
 
 			__run_hrtimer(timer, &basenow);
 		}
 	}
-
+	/* Reevaluate the clock bases for the next expiry */
+	expires_next = __hrtimer_get_next_event(cpu_base);
 	/*
 	 * Store the new expiry value so the migration code can verify
 	 * against it.
 	 */
 	cpu_base->expires_next = expires_next;
+	cpu_base->in_hrtirq = 0;
 	raw_spin_unlock(&cpu_base->lock);
 
 	/* Reprogramming necessary ? */

kernel/time/ntp.c

@@ -488,13 +488,13 @@ static void sync_cmos_clock(struct work_struct *work)
 
 	getnstimeofday64(&now);
 	if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec * 5) {
-		struct timespec adjust = timespec64_to_timespec(now);
+		struct timespec64 adjust = now;
 
 		fail = -ENODEV;
 		if (persistent_clock_is_local)
 			adjust.tv_sec -= (sys_tz.tz_minuteswest * 60);
 #ifdef CONFIG_GENERIC_CMOS_UPDATE
-		fail = update_persistent_clock(adjust);
+		fail = update_persistent_clock(timespec64_to_timespec(adjust));
 #endif
 #ifdef CONFIG_RTC_SYSTOHC
 		if (fail == -ENODEV)

kernel/time/timekeeping.c

@@ -1659,24 +1659,24 @@ void update_wall_time(void)
 }
 
 /**
- * getboottime - Return the real time of system boot.
- * @ts:		pointer to the timespec to be set
+ * getboottime64 - Return the real time of system boot.
+ * @ts:		pointer to the timespec64 to be set
  *
- * Returns the wall-time of boot in a timespec.
+ * Returns the wall-time of boot in a timespec64.
  *
  * This is based on the wall_to_monotonic offset and the total suspend
  * time. Calls to settimeofday will affect the value returned (which
  * basically means that however wrong your real time clock is at boot time,
  * you get the right time here).
  */
-void getboottime(struct timespec *ts)
+void getboottime64(struct timespec64 *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
 	ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot);
 
-	*ts = ktime_to_timespec(t);
+	*ts = ktime_to_timespec64(t);
 }
-EXPORT_SYMBOL_GPL(getboottime);
+EXPORT_SYMBOL_GPL(getboottime64);
 
 unsigned long get_seconds(void)
 {