Merge branch 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  hrtimers: Reorder clock bases
  hrtimers: Avoid touching inactive timer bases
  hrtimers: Make struct hrtimer_cpu_base layout less stupid
  timerfd: Manage cancelable timers in timerfd
  clockevents: Move C3 stop test outside lock
  alarmtimer: Drop device refcount after rtc_open()
  alarmtimer: Check return value of class_find_device()
  timerfd: Allow timers to be cancelled when clock was set
  hrtimers: Prepare for cancel on clock was set timers

10 files changed, 239 insertions, 118 deletions

diff --git a/fs/timerfd.c b/fs/timerfd.c
index 8c4fc1425b3e..f67acbdda5e8 100644
--- a/fs/timerfd.c
+++ b/fs/timerfd.c
@@ -22,16 +22,24 @@
 #include <linux/anon_inodes.h>
 #include <linux/timerfd.h>
 #include <linux/syscalls.h>
+#include <linux/rcupdate.h>
 
 struct timerfd_ctx {
         struct hrtimer tmr;
         ktime_t tintv;
+        ktime_t moffs;
         wait_queue_head_t wqh;
         u64 ticks;
         int expired;
         int clockid;
+        struct rcu_head rcu;
+        struct list_head clist;
+        bool might_cancel;
 };
 
+static LIST_HEAD(cancel_list);
+static DEFINE_SPINLOCK(cancel_lock);
+
 /*
  * This gets called when the timer event triggers. We set the "expired"
  * flag, but we do not re-arm the timer (in case it's necessary,
@@ -51,6 +59,63 @@ static enum hrtimer_restart timerfd_tmrproc(struct hrtimer *htmr)
         return HRTIMER_NORESTART;
 }
 
+/*
+ * Called when the clock was set to cancel the timers in the cancel
+ * list.
+ */
+void timerfd_clock_was_set(void)
+{
+        ktime_t moffs = ktime_get_monotonic_offset();
+        struct timerfd_ctx *ctx;
+        unsigned long flags;
+
+        rcu_read_lock();
+        list_for_each_entry_rcu(ctx, &cancel_list, clist) {
+                if (!ctx->might_cancel)
+                        continue;
+                spin_lock_irqsave(&ctx->wqh.lock, flags);
+                if (ctx->moffs.tv64 != moffs.tv64) {
+                        ctx->moffs.tv64 = KTIME_MAX;
+                        wake_up_locked(&ctx->wqh);
+                }
+                spin_unlock_irqrestore(&ctx->wqh.lock, flags);
+        }
+        rcu_read_unlock();
+}
+
+static void timerfd_remove_cancel(struct timerfd_ctx *ctx)
+{
+        if (ctx->might_cancel) {
+                ctx->might_cancel = false;
+                spin_lock(&cancel_lock);
+                list_del_rcu(&ctx->clist);
+                spin_unlock(&cancel_lock);
+        }
+}
+
+static bool timerfd_canceled(struct timerfd_ctx *ctx)
+{
+        if (!ctx->might_cancel || ctx->moffs.tv64 != KTIME_MAX)
+                return false;
+        ctx->moffs = ktime_get_monotonic_offset();
+        return true;
+}
+
+static void timerfd_setup_cancel(struct timerfd_ctx *ctx, int flags)
+{
+        if (ctx->clockid == CLOCK_REALTIME && (flags & TFD_TIMER_ABSTIME) &&
+            (flags & TFD_TIMER_CANCEL_ON_SET)) {
+                if (!ctx->might_cancel) {
+                        ctx->might_cancel = true;
+                        spin_lock(&cancel_lock);
+                        list_add_rcu(&ctx->clist, &cancel_list);
+                        spin_unlock(&cancel_lock);
+                }
+        } else if (ctx->might_cancel) {
+                timerfd_remove_cancel(ctx);
+        }
+}
+
 static ktime_t timerfd_get_remaining(struct timerfd_ctx *ctx)
 {
         ktime_t remaining;
@@ -59,11 +124,12 @@ static ktime_t timerfd_get_remaining(struct timerfd_ctx *ctx)
         return remaining.tv64 < 0 ? ktime_set(0, 0): remaining;
 }
 
-static void timerfd_setup(struct timerfd_ctx *ctx, int flags,
-                          const struct itimerspec *ktmr)
+static int timerfd_setup(struct timerfd_ctx *ctx, int flags,
+                         const struct itimerspec *ktmr)
 {
         enum hrtimer_mode htmode;
         ktime_t texp;
+        int clockid = ctx->clockid;
 
         htmode = (flags & TFD_TIMER_ABSTIME) ?
                 HRTIMER_MODE_ABS: HRTIMER_MODE_REL;
@@ -72,19 +138,24 @@ static void timerfd_setup(struct timerfd_ctx *ctx, int flags,
         ctx->expired = 0;
         ctx->ticks = 0;
         ctx->tintv = timespec_to_ktime(ktmr->it_interval);
-        hrtimer_init(&ctx->tmr, ctx->clockid, htmode);
+        hrtimer_init(&ctx->tmr, clockid, htmode);
         hrtimer_set_expires(&ctx->tmr, texp);
         ctx->tmr.function = timerfd_tmrproc;
-        if (texp.tv64 != 0)
+        if (texp.tv64 != 0) {
                 hrtimer_start(&ctx->tmr, texp, htmode);
+                if (timerfd_canceled(ctx))
+                        return -ECANCELED;
+        }
+        return 0;
 }
 
 static int timerfd_release(struct inode *inode, struct file *file)
 {
         struct timerfd_ctx *ctx = file->private_data;
 
+        timerfd_remove_cancel(ctx);
         hrtimer_cancel(&ctx->tmr);
-        kfree(ctx);
+        kfree_rcu(ctx, rcu);
         return 0;
 }
 
@@ -118,8 +189,21 @@ static ssize_t timerfd_read(struct file *file, char __user *buf, size_t count,
                 res = -EAGAIN;
         else
                 res = wait_event_interruptible_locked_irq(ctx->wqh, ctx->ticks);
+
+        /*
+         * If clock has changed, we do not care about the
+         * ticks and we do not rearm the timer. Userspace must
+         * reevaluate anyway.
+         */
+        if (timerfd_canceled(ctx)) {
+                ctx->ticks = 0;
+                ctx->expired = 0;
+                res = -ECANCELED;
+        }
+
         if (ctx->ticks) {
                 ticks = ctx->ticks;
+
                 if (ctx->expired && ctx->tintv.tv64) {
                         /*
                          * If tintv.tv64 != 0, this is a periodic timer that
@@ -183,6 +267,7 @@ SYSCALL_DEFINE2(timerfd_create, int, clockid, int, flags)
         init_waitqueue_head(&ctx->wqh);
         ctx->clockid = clockid;
         hrtimer_init(&ctx->tmr, clockid, HRTIMER_MODE_ABS);
+        ctx->moffs = ktime_get_monotonic_offset();
 
         ufd = anon_inode_getfd("[timerfd]", &timerfd_fops, ctx,
                                O_RDWR | (flags & TFD_SHARED_FCNTL_FLAGS));
@@ -199,6 +284,7 @@ SYSCALL_DEFINE4(timerfd_settime, int, ufd, int, flags,
         struct file *file;
         struct timerfd_ctx *ctx;
         struct itimerspec ktmr, kotmr;
+        int ret;
 
         if (copy_from_user(&ktmr, utmr, sizeof(ktmr)))
                 return -EFAULT;
@@ -213,6 +299,8 @@ SYSCALL_DEFINE4(timerfd_settime, int, ufd, int, flags,
                 return PTR_ERR(file);
         ctx = file->private_data;
 
+        timerfd_setup_cancel(ctx, flags);
+
         /*
          * We need to stop the existing timer before reprogramming
          * it to the new values.
@@ -240,14 +328,14 @@ SYSCALL_DEFINE4(timerfd_settime, int, ufd, int, flags,
         /*
          * Re-program the timer to the new value ...
          */
-        timerfd_setup(ctx, flags, &ktmr);
+        ret = timerfd_setup(ctx, flags, &ktmr);
 
         spin_unlock_irq(&ctx->wqh.lock);
         fput(file);
         if (otmr && copy_to_user(otmr, &kotmr, sizeof(kotmr)))
                 return -EFAULT;
 
-        return 0;
+        return ret;
 }
 
 SYSCALL_DEFINE2(timerfd_gettime, int, ufd, struct itimerspec __user *, otmr)
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 62f500c724f9..51932e5acf7c 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -143,19 +143,18 @@ struct hrtimer_sleeper {
  */
 struct hrtimer_clock_base {
         struct hrtimer_cpu_base *cpu_base;
-        clockid_t               index;
+        int                     index;
+        clockid_t               clockid;
         struct timerqueue_head  active;
         ktime_t                 resolution;
         ktime_t                 (*get_time)(void);
         ktime_t                 softirq_time;
-#ifdef CONFIG_HIGH_RES_TIMERS
         ktime_t                 offset;
-#endif
 };
 
 enum  hrtimer_base_type {
-        HRTIMER_BASE_REALTIME,
         HRTIMER_BASE_MONOTONIC,
+        HRTIMER_BASE_REALTIME,
         HRTIMER_BASE_BOOTTIME,
         HRTIMER_MAX_CLOCK_BASES,
 };
@@ -164,7 +163,7 @@ enum  hrtimer_base_type {
  * struct hrtimer_cpu_base - the per cpu clock bases
  * @lock:               lock protecting the base and associated clock bases
  *                      and timers
- * @clock_base:         array of clock bases for this cpu
+ * @active_bases:       Bitfield to mark bases with active timers
  * @expires_next:       absolute time of the next event which was scheduled
  *                      via clock_set_next_event()
  * @hres_active:        State of high resolution mode
@@ -173,10 +172,11 @@ enum  hrtimer_base_type {
  * @nr_retries:         Total number of hrtimer interrupt retries
  * @nr_hangs:           Total number of hrtimer interrupt hangs
  * @max_hang_time:      Maximum time spent in hrtimer_interrupt
+ * @clock_base:         array of clock bases for this cpu
  */
 struct hrtimer_cpu_base {
         raw_spinlock_t                  lock;
-        struct hrtimer_clock_base       clock_base[HRTIMER_MAX_CLOCK_BASES];
+        unsigned long                   active_bases;
 #ifdef CONFIG_HIGH_RES_TIMERS
         ktime_t                         expires_next;
         int                             hres_active;
@@ -186,6 +186,7 @@ struct hrtimer_cpu_base {
         unsigned long                   nr_hangs;
         ktime_t                         max_hang_time;
 #endif
+        struct hrtimer_clock_base       clock_base[HRTIMER_MAX_CLOCK_BASES];
 };
 
 static inline void hrtimer_set_expires(struct hrtimer *timer, ktime_t time)
@@ -256,8 +257,6 @@ static inline ktime_t hrtimer_expires_remaining(const struct hrtimer *timer)
 #ifdef CONFIG_HIGH_RES_TIMERS
 struct clock_event_device;
 
-extern void clock_was_set(void);
-extern void hres_timers_resume(void);
 extern void hrtimer_interrupt(struct clock_event_device *dev);
 
 /*
@@ -291,16 +290,8 @@ extern void hrtimer_peek_ahead_timers(void);
 # define MONOTONIC_RES_NSEC     LOW_RES_NSEC
 # define KTIME_MONOTONIC_RES    KTIME_LOW_RES
 
-/*
- * clock_was_set() is a NOP for non- high-resolution systems. The
- * time-sorted order guarantees that a timer does not expire early and
- * is expired in the next softirq when the clock was advanced.
- */
-static inline void clock_was_set(void) { }
 static inline void hrtimer_peek_ahead_timers(void) { }
 
-static inline void hres_timers_resume(void) { }
-
 /*
  * In non high resolution mode the time reference is taken from
  * the base softirq time variable.
@@ -316,10 +307,18 @@ static inline int hrtimer_is_hres_active(struct hrtimer *timer)
 }
 #endif
 
+extern void clock_was_set(void);
+#ifdef CONFIG_TIMERFD
+extern void timerfd_clock_was_set(void);
+#else
+static inline void timerfd_clock_was_set(void) { }
+#endif
+extern void hrtimers_resume(void);
+
 extern ktime_t ktime_get(void);
 extern ktime_t ktime_get_real(void);
 extern ktime_t ktime_get_boottime(void);
-
+extern ktime_t ktime_get_monotonic_offset(void);
 
 DECLARE_PER_CPU(struct tick_device, tick_cpu_device);
 
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index 20fc303947d3..8d03f079688c 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -29,7 +29,7 @@ struct restart_block {
                 } futex;
                 /* For nanosleep */
                 struct {
-                        clockid_t index;
+                        clockid_t clockid;
                         struct timespec __user *rmtp;
 #ifdef CONFIG_COMPAT
                         struct compat_timespec __user *compat_rmtp;
diff --git a/include/linux/timerfd.h b/include/linux/timerfd.h
index 2d0792983f8c..d3b57fa12225 100644
--- a/include/linux/timerfd.h
+++ b/include/linux/timerfd.h
@@ -19,6 +19,7 @@
  * shared O_* flags.
  */
 #define TFD_TIMER_ABSTIME (1 << 0)
+#define TFD_TIMER_CANCEL_ON_SET (1 << 1)
 #define TFD_CLOEXEC O_CLOEXEC
 #define TFD_NONBLOCK O_NONBLOCK
 
@@ -26,6 +27,6 @@
 /* Flags for timerfd_create.  */
 #define TFD_CREATE_FLAGS TFD_SHARED_FCNTL_FLAGS
 /* Flags for timerfd_settime.  */
-#define TFD_SETTIME_FLAGS TFD_TIMER_ABSTIME
+#define TFD_SETTIME_FLAGS (TFD_TIMER_ABSTIME | TFD_TIMER_CANCEL_ON_SET)
 
 #endif /* _LINUX_TIMERFD_H */
diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index dbbbf7d43080..c541ee527ecb 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -64,17 +64,20 @@ DEFINE_PER_CPU(struct hrtimer_cpu_base, hrtimer_bases) =
         .clock_base =
         {
                 {
-                        .index = CLOCK_REALTIME,
-                        .get_time = &ktime_get_real,
+                        .index = HRTIMER_BASE_MONOTONIC,
+                        .clockid = CLOCK_MONOTONIC,
+                        .get_time = &ktime_get,
                         .resolution = KTIME_LOW_RES,
                 },
                 {
-                        .index = CLOCK_MONOTONIC,
-                        .get_time = &ktime_get,
+                        .index = HRTIMER_BASE_REALTIME,
+                        .clockid = CLOCK_REALTIME,
+                        .get_time = &ktime_get_real,
                         .resolution = KTIME_LOW_RES,
                 },
                 {
-                        .index = CLOCK_BOOTTIME,
+                        .index = HRTIMER_BASE_BOOTTIME,
+                        .clockid = CLOCK_BOOTTIME,
                         .get_time = &ktime_get_boottime,
                         .resolution = KTIME_LOW_RES,
                 },
@@ -196,7 +199,7 @@ switch_hrtimer_base(struct hrtimer *timer, struct hrtimer_clock_base *base,
         struct hrtimer_cpu_base *new_cpu_base;
         int this_cpu = smp_processor_id();
         int cpu = hrtimer_get_target(this_cpu, pinned);
-        int basenum = hrtimer_clockid_to_base(base->index);
+        int basenum = base->index;
 
 again:
         new_cpu_base = &per_cpu(hrtimer_bases, cpu);
@@ -621,66 +624,6 @@ static int hrtimer_reprogram(struct hrtimer *timer,
         return res;
 }
 
-
-/*
- * Retrigger next event is called after clock was set
- *
- * Called with interrupts disabled via on_each_cpu()
- */
-static void retrigger_next_event(void *arg)
-{
-        struct hrtimer_cpu_base *base;
-        struct timespec realtime_offset, wtm, sleep;
-
-        if (!hrtimer_hres_active())
-                return;
-
-        get_xtime_and_monotonic_and_sleep_offset(&realtime_offset, &wtm,
-                                                        &sleep);
-        set_normalized_timespec(&realtime_offset, -wtm.tv_sec, -wtm.tv_nsec);
-
-        base = &__get_cpu_var(hrtimer_bases);
-
-        /* Adjust CLOCK_REALTIME offset */
-        raw_spin_lock(&base->lock);
-        base->clock_base[HRTIMER_BASE_REALTIME].offset =
-                timespec_to_ktime(realtime_offset);
-        base->clock_base[HRTIMER_BASE_BOOTTIME].offset =
-                timespec_to_ktime(sleep);
-
-        hrtimer_force_reprogram(base, 0);
-        raw_spin_unlock(&base->lock);
-}
-
-/*
- * Clock realtime was set
- *
- * Change the offset of the realtime clock vs. the monotonic
- * clock.
- *
- * We might have to reprogram the high resolution timer interrupt. On
- * SMP we call the architecture specific code to retrigger _all_ high
- * resolution timer interrupts. On UP we just disable interrupts and
- * call the high resolution interrupt code.
- */
-void clock_was_set(void)
-{
-        /* Retrigger the CPU local events everywhere */
-        on_each_cpu(retrigger_next_event, NULL, 1);
-}
-
-/*
- * During resume we might have to reprogram the high resolution timer
- * interrupt (on the local CPU):
- */
-void hres_timers_resume(void)
-{
-        WARN_ONCE(!irqs_disabled(),
-                  KERN_INFO "hres_timers_resume() called with IRQs enabled!");
-
-        retrigger_next_event(NULL);
-}
-
 /*
  * Initialize the high resolution related parts of cpu_base
  */
@@ -715,11 +658,39 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
 }
 
 /*
+ * Retrigger next event is called after clock was set
+ *
+ * Called with interrupts disabled via on_each_cpu()
+ */
+static void retrigger_next_event(void *arg)
+{
+        struct hrtimer_cpu_base *base = &__get_cpu_var(hrtimer_bases);
+        struct timespec realtime_offset, xtim, wtm, sleep;
+
+        if (!hrtimer_hres_active())
+                return;
+
+        /* Optimized out for !HIGH_RES */
+        get_xtime_and_monotonic_and_sleep_offset(&xtim, &wtm, &sleep);
+        set_normalized_timespec(&realtime_offset, -wtm.tv_sec, -wtm.tv_nsec);
+
+        /* Adjust CLOCK_REALTIME offset */
+        raw_spin_lock(&base->lock);
+        base->clock_base[HRTIMER_BASE_REALTIME].offset =
+                timespec_to_ktime(realtime_offset);
+        base->clock_base[HRTIMER_BASE_BOOTTIME].offset =
+                timespec_to_ktime(sleep);
+
+        hrtimer_force_reprogram(base, 0);
+        raw_spin_unlock(&base->lock);
+}
+
+/*
  * Switch to high resolution mode
  */
 static int hrtimer_switch_to_hres(void)
 {
-        int cpu = smp_processor_id();
+        int i, cpu = smp_processor_id();
         struct hrtimer_cpu_base *base = &per_cpu(hrtimer_bases, cpu);
         unsigned long flags;
 
@@ -735,9 +706,8 @@ static int hrtimer_switch_to_hres(void)
                 return 0;
         }
         base->hres_active = 1;
-        base->clock_base[HRTIMER_BASE_REALTIME].resolution = KTIME_HIGH_RES;
-        base->clock_base[HRTIMER_BASE_MONOTONIC].resolution = KTIME_HIGH_RES;
-        base->clock_base[HRTIMER_BASE_BOOTTIME].resolution = KTIME_HIGH_RES;
+        for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++)
+                base->clock_base[i].resolution = KTIME_HIGH_RES;
 
         tick_setup_sched_timer();
 
@@ -761,9 +731,43 @@ static inline int hrtimer_enqueue_reprogram(struct hrtimer *timer,
         return 0;
 }
 static inline void hrtimer_init_hres(struct hrtimer_cpu_base *base) { }
+static inline void retrigger_next_event(void *arg) { }
 
 #endif /* CONFIG_HIGH_RES_TIMERS */
 
+/*
+ * Clock realtime was set
+ *
+ * Change the offset of the realtime clock vs. the monotonic
+ * clock.
+ *
+ * We might have to reprogram the high resolution timer interrupt. On
+ * SMP we call the architecture specific code to retrigger _all_ high
+ * resolution timer interrupts. On UP we just disable interrupts and
+ * call the high resolution interrupt code.
+ */
+void clock_was_set(void)
+{
+#ifdef CONFIG_HIGHRES_TIMERS
+        /* Retrigger the CPU local events everywhere */
+        on_each_cpu(retrigger_next_event, NULL, 1);
+#endif
+        timerfd_clock_was_set();
+}
+
+/*
+ * During resume we might have to reprogram the high resolution timer
+ * interrupt (on the local CPU):
+ */
+void hrtimers_resume(void)
+{
+        WARN_ONCE(!irqs_disabled(),
+                  KERN_INFO "hrtimers_resume() called with IRQs enabled!");
+
+        retrigger_next_event(NULL);
+        timerfd_clock_was_set();
+}
+
 static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
 {
 #ifdef CONFIG_TIMER_STATS
@@ -856,6 +860,7 @@ static int enqueue_hrtimer(struct hrtimer *timer,
         debug_activate(timer);
 
         timerqueue_add(&base->active, &timer->node);
+        base->cpu_base->active_bases |= 1 << base->index;
 
         /*
          * HRTIMER_STATE_ENQUEUED is or'ed to the current state to preserve the
@@ -897,6 +902,8 @@ static void __remove_hrtimer(struct hrtimer *timer,
 #endif
         }
         timerqueue_del(&base->active, &timer->node);
+        if (!timerqueue_getnext(&base->active))
+                base->cpu_base->active_bases &= ~(1 << base->index);
 out:
         timer->state = newstate;
 }
@@ -1234,7 +1241,6 @@ static void __run_hrtimer(struct hrtimer *timer, ktime_t *now)
 void hrtimer_interrupt(struct clock_event_device *dev)
 {
         struct hrtimer_cpu_base *cpu_base = &__get_cpu_var(hrtimer_bases);
-        struct hrtimer_clock_base *base;
         ktime_t expires_next, now, entry_time, delta;
         int i, retries = 0;
 
@@ -1256,12 +1262,15 @@ retry:
          */
         cpu_base->expires_next.tv64 = KTIME_MAX;
 
-        base = cpu_base->clock_base;
-
         for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
-                ktime_t basenow;
+                struct hrtimer_clock_base *base;
                 struct timerqueue_node *node;
+                ktime_t basenow;
+
+                if (!(cpu_base->active_bases & (1 << i)))
+                        continue;
 
+                base = cpu_base->clock_base + i;
                 basenow = ktime_add(now, base->offset);
 
                 while ((node = timerqueue_getnext(&base->active))) {
@@ -1294,7 +1303,6 @@ retry:
 
                         __run_hrtimer(timer, &basenow);
                 }
-                base++;
         }
 
         /*
@@ -1525,7 +1533,7 @@ long __sched hrtimer_nanosleep_restart(struct restart_block *restart)
         struct timespec __user  *rmtp;
         int ret = 0;
 
-        hrtimer_init_on_stack(&t.timer, restart->nanosleep.index,
+        hrtimer_init_on_stack(&t.timer, restart->nanosleep.clockid,
                                 HRTIMER_MODE_ABS);
         hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
 
@@ -1577,7 +1585,7 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
 
         restart = &current_thread_info()->restart_block;
         restart->fn = hrtimer_nanosleep_restart;
-        restart->nanosleep.index = t.timer.base->index;
+        restart->nanosleep.clockid = t.timer.base->clockid;
         restart->nanosleep.rmtp = rmtp;
         restart->nanosleep.expires = hrtimer_get_expires_tv64(&t.timer);
 
diff --git a/kernel/posix-cpu-timers.c b/kernel/posix-cpu-timers.c
index 0791b13df7bf..58f405b581e7 100644
--- a/kernel/posix-cpu-timers.c
+++ b/kernel/posix-cpu-timers.c
@@ -1514,7 +1514,7 @@ static int posix_cpu_nsleep(const clockid_t which_clock, int flags,
                         return -EFAULT;
 
                 restart_block->fn = posix_cpu_nsleep_restart;
-                restart_block->nanosleep.index = which_clock;
+                restart_block->nanosleep.clockid = which_clock;
                 restart_block->nanosleep.rmtp = rmtp;
                 restart_block->nanosleep.expires = timespec_to_ns(rqtp);
         }
@@ -1523,7 +1523,7 @@ static int posix_cpu_nsleep(const clockid_t which_clock, int flags,
 
 static long posix_cpu_nsleep_restart(struct restart_block *restart_block)
 {
-        clockid_t which_clock = restart_block->nanosleep.index;
+        clockid_t which_clock = restart_block->nanosleep.clockid;
         struct timespec t;
         struct itimerspec it;
         int error;
diff --git a/kernel/posix-timers.c b/kernel/posix-timers.c
index e5498d7405c3..a1b5edf1bf92 100644
--- a/kernel/posix-timers.c
+++ b/kernel/posix-timers.c
@@ -1056,7 +1056,7 @@ SYSCALL_DEFINE4(clock_nanosleep, const clockid_t, which_clock, int, flags,
  */
 long clock_nanosleep_restart(struct restart_block *restart_block)
 {
-        clockid_t which_clock = restart_block->nanosleep.index;
+        clockid_t which_clock = restart_block->nanosleep.clockid;
         struct k_clock *kc = clockid_to_kclock(which_clock);
 
         if (WARN_ON_ONCE(!kc || !kc->nsleep_restart))
diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c
index 9265014cb4db..2d966244ea60 100644
--- a/kernel/time/alarmtimer.c
+++ b/kernel/time/alarmtimer.c
@@ -494,7 +494,7 @@ static int update_rmtp(ktime_t exp, enum  alarmtimer_type type,
  */
 static long __sched alarm_timer_nsleep_restart(struct restart_block *restart)
 {
-        enum  alarmtimer_type type = restart->nanosleep.index;
+        enum  alarmtimer_type type = restart->nanosleep.clockid;
         ktime_t exp;
         struct timespec __user  *rmtp;
         struct alarm alarm;
@@ -573,7 +573,7 @@ static int alarm_timer_nsleep(const clockid_t which_clock, int flags,
 
         restart = &current_thread_info()->restart_block;
         restart->fn = alarm_timer_nsleep_restart;
-        restart->nanosleep.index = type;
+        restart->nanosleep.clockid = type;
         restart->nanosleep.expires = exp.tv64;
         restart->nanosleep.rmtp = rmtp;
         ret = -ERESTART_RESTARTBLOCK;
@@ -669,12 +669,20 @@ static int __init has_wakealarm(struct device *dev, void *name_ptr)
  */
 static int __init alarmtimer_init_late(void)
 {
+        struct device *dev;
         char *str;
 
         /* Find an rtc device and init the rtc_timer */
-        class_find_device(rtc_class, NULL, &str, has_wakealarm);
-        if (str)
+        dev = class_find_device(rtc_class, NULL, &str, has_wakealarm);
+        /* If we have a device then str is valid. See has_wakealarm() */
+        if (dev) {
                 rtcdev = rtc_class_open(str);
+                /*
+                 * Drop the reference we got in class_find_device,
+                 * rtc_open takes its own.
+                 */
+                put_device(dev);
+        }
         if (!rtcdev) {
                 printk(KERN_WARNING "No RTC device found, ALARM timers will"
                         " not wake from suspend");
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c
index 723c7637e55a..c7218d132738 100644
--- a/kernel/time/tick-broadcast.c
+++ b/kernel/time/tick-broadcast.c
@@ -456,23 +456,27 @@ void tick_broadcast_oneshot_control(unsigned long reason)
         unsigned long flags;
         int cpu;
 
-        raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
-
         /*
          * Periodic mode does not care about the enter/exit of power
          * states
          */
         if (tick_broadcast_device.mode == TICKDEV_MODE_PERIODIC)
-                goto out;
+                return;
 
-        bc = tick_broadcast_device.evtdev;
+        /*
+         * We are called with preemtion disabled from the depth of the
+         * idle code, so we can't be moved away.
+         */
         cpu = smp_processor_id();
         td = &per_cpu(tick_cpu_device, cpu);
         dev = td->evtdev;
 
         if (!(dev->features & CLOCK_EVT_FEAT_C3STOP))
-                goto out;
+                return;
+
+        bc = tick_broadcast_device.evtdev;
 
+        raw_spin_lock_irqsave(&tick_broadcast_lock, flags);
         if (reason == CLOCK_EVT_NOTIFY_BROADCAST_ENTER) {
                 if (!cpumask_test_cpu(cpu, tick_get_broadcast_oneshot_mask())) {
                         cpumask_set_cpu(cpu, tick_get_broadcast_oneshot_mask());
@@ -489,8 +493,6 @@ void tick_broadcast_oneshot_control(unsigned long reason)
                                 tick_program_event(dev->next_event, 1);
                 }
         }
-
-out:
         raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);
 }
 
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 8e6a05a5915a..342408cf68dd 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -680,7 +680,7 @@ static void timekeeping_resume(void)
         clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);
 
         /* Resume hrtimers */
-        hres_timers_resume();
+        hrtimers_resume();
 }
 
 static int timekeeping_suspend(void)
@@ -1099,6 +1099,21 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
 }
 
 /**
+ * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format
+ */
+ktime_t ktime_get_monotonic_offset(void)
+{
+        unsigned long seq;
+        struct timespec wtom;
+
+        do {
+                seq = read_seqbegin(&xtime_lock);
+                wtom = wall_to_monotonic;
+        } while (read_seqretry(&xtime_lock, seq));
+        return timespec_to_ktime(wtom);
+}
+
+/**
  * xtime_update() - advances the timekeeping infrastructure
  * @ticks:      number of ticks, that have elapsed since the last call.
  *