1 files changed, 96 insertions, 97 deletions

diff --git a/kernel/hrtimer.c b/kernel/hrtimer.c
index 14bc9cfa6399..0237a556eb1f 100644
--- a/kernel/hrtimer.c
+++ b/kernel/hrtimer.c
@@ -123,6 +123,26 @@ void ktime_get_ts(struct timespec *ts)
 EXPORT_SYMBOL_GPL(ktime_get_ts);
 
 /*
+ * Get the coarse grained time at the softirq based on xtime and
+ * wall_to_monotonic.
+ */
+static void hrtimer_get_softirq_time(struct hrtimer_base *base)
+{
+        ktime_t xtim, tomono;
+        unsigned long seq;
+
+        do {
+                seq = read_seqbegin(&xtime_lock);
+                xtim = timespec_to_ktime(xtime);
+                tomono = timespec_to_ktime(wall_to_monotonic);
+
+        } while (read_seqretry(&xtime_lock, seq));
+
+        base[CLOCK_REALTIME].softirq_time = xtim;
+        base[CLOCK_MONOTONIC].softirq_time = ktime_add(xtim, tomono);
+}
+
+/*
  * Functions and macros which are different for UP/SMP systems are kept in a
  * single place
  */
@@ -246,7 +266,7 @@ ktime_t ktime_add_ns(const ktime_t kt, u64 nsec)
 /*
  * Divide a ktime value by a nanosecond value
  */
-static unsigned long ktime_divns(const ktime_t kt, nsec_t div)
+static unsigned long ktime_divns(const ktime_t kt, s64 div)
 {
         u64 dclc, inc, dns;
         int sft = 0;
@@ -281,18 +301,17 @@ void unlock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
  * hrtimer_forward - forward the timer expiry
  *
  * @timer:      hrtimer to forward
+ * @now:        forward past this time
  * @interval:   the interval to forward
  *
  * Forward the timer expiry so it will expire in the future.
  * Returns the number of overruns.
  */
 unsigned long
-hrtimer_forward(struct hrtimer *timer, ktime_t interval)
+hrtimer_forward(struct hrtimer *timer, ktime_t now, ktime_t interval)
 {
         unsigned long orun = 1;
-        ktime_t delta, now;
-
-        now = timer->base->get_time();
+        ktime_t delta;
 
         delta = ktime_sub(now, timer->expires);
 
@@ -303,7 +322,7 @@ hrtimer_forward(struct hrtimer *timer, ktime_t interval)
                 interval.tv64 = timer->base->resolution.tv64;
 
         if (unlikely(delta.tv64 >= interval.tv64)) {
-                nsec_t incr = ktime_to_ns(interval);
+                s64 incr = ktime_to_ns(interval);
 
                 orun = ktime_divns(delta, incr);
                 timer->expires = ktime_add_ns(timer->expires, incr * orun);
@@ -355,8 +374,6 @@ static void enqueue_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
         rb_link_node(&timer->node, parent, link);
         rb_insert_color(&timer->node, &base->active);
 
-        timer->state = HRTIMER_PENDING;
-
         if (!base->first || timer->expires.tv64 <
             rb_entry(base->first, struct hrtimer, node)->expires.tv64)
                 base->first = &timer->node;
@@ -376,6 +393,7 @@ static void __remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
         if (base->first == &timer->node)
                 base->first = rb_next(&timer->node);
         rb_erase(&timer->node, &base->active);
+        timer->node.rb_parent = HRTIMER_INACTIVE;
 }
 
 /*
@@ -386,7 +404,6 @@ remove_hrtimer(struct hrtimer *timer, struct hrtimer_base *base)
 {
         if (hrtimer_active(timer)) {
                 __remove_hrtimer(timer, base);
-                timer->state = HRTIMER_INACTIVE;
                 return 1;
         }
         return 0;
@@ -560,6 +577,7 @@ void hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
                 clock_id = CLOCK_MONOTONIC;
 
         timer->base = &bases[clock_id];
+        timer->node.rb_parent = HRTIMER_INACTIVE;
 }
 
 /**
@@ -586,48 +604,35 @@ int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp)
  */
 static inline void run_hrtimer_queue(struct hrtimer_base *base)
 {
-        ktime_t now = base->get_time();
         struct rb_node *node;
 
+        if (base->get_softirq_time)
+                base->softirq_time = base->get_softirq_time();
+
         spin_lock_irq(&base->lock);
 
         while ((node = base->first)) {
                 struct hrtimer *timer;
-                int (*fn)(void *);
+                int (*fn)(struct hrtimer *);
                 int restart;
-                void *data;
 
                 timer = rb_entry(node, struct hrtimer, node);
-                if (now.tv64 <= timer->expires.tv64)
+                if (base->softirq_time.tv64 <= timer->expires.tv64)
                         break;
 
                 fn = timer->function;
-                data = timer->data;
                 set_curr_timer(base, timer);
-                timer->state = HRTIMER_RUNNING;
                 __remove_hrtimer(timer, base);
                 spin_unlock_irq(&base->lock);
 
-                /*
-                 * fn == NULL is special case for the simplest timer
-                 * variant - wake up process and do not restart:
-                 */
-                if (!fn) {
-                        wake_up_process(data);
-                        restart = HRTIMER_NORESTART;
-                } else
-                        restart = fn(data);
+                restart = fn(timer);
 
                 spin_lock_irq(&base->lock);
 
-                /* Another CPU has added back the timer */
-                if (timer->state != HRTIMER_RUNNING)
-                        continue;
-
-                if (restart == HRTIMER_RESTART)
+                if (restart != HRTIMER_NORESTART) {
+                        BUG_ON(hrtimer_active(timer));
                         enqueue_hrtimer(timer, base);
-                else
-                        timer->state = HRTIMER_EXPIRED;
+                }
         }
         set_curr_timer(base, NULL);
         spin_unlock_irq(&base->lock);
@@ -641,6 +646,8 @@ void hrtimer_run_queues(void)
         struct hrtimer_base *base = __get_cpu_var(hrtimer_bases);
         int i;
 
+        hrtimer_get_softirq_time(base);
+
         for (i = 0; i < MAX_HRTIMER_BASES; i++)
                 run_hrtimer_queue(&base[i]);
 }
@@ -649,79 +656,70 @@ void hrtimer_run_queues(void)
  * Sleep related functions:
  */
 
-/**
- * schedule_hrtimer - sleep until timeout
- *
- * @timer:      hrtimer variable initialized with the correct clock base
- * @mode:       timeout value is abs/rel
- *
- * Make the current task sleep until @timeout is
- * elapsed.
- *
- * You can set the task state as follows -
- *
- * %TASK_UNINTERRUPTIBLE - at least @timeout is guaranteed to
- * pass before the routine returns. The routine will return 0
- *
- * %TASK_INTERRUPTIBLE - the routine may return early if a signal is
- * delivered to the current task. In this case the remaining time
- * will be returned
- *
- * The current task state is guaranteed to be TASK_RUNNING when this
- * routine returns.
- */
-static ktime_t __sched
-schedule_hrtimer(struct hrtimer *timer, const enum hrtimer_mode mode)
-{
-        /* fn stays NULL, meaning single-shot wakeup: */
-        timer->data = current;
+struct sleep_hrtimer {
+        struct hrtimer timer;
+        struct task_struct *task;
+        int expired;
+};
 
-        hrtimer_start(timer, timer->expires, mode);
+static int nanosleep_wakeup(struct hrtimer *timer)
+{
+        struct sleep_hrtimer *t =
+                container_of(timer, struct sleep_hrtimer, timer);
 
-        schedule();
-        hrtimer_cancel(timer);
+        t->expired = 1;
+        wake_up_process(t->task);
 
-        /* Return the remaining time: */
-        if (timer->state != HRTIMER_EXPIRED)
-                return ktime_sub(timer->expires, timer->base->get_time());
-        else
-                return (ktime_t) {.tv64 = 0 };
+        return HRTIMER_NORESTART;
 }
 
-static inline ktime_t __sched
-schedule_hrtimer_interruptible(struct hrtimer *timer,
-                               const enum hrtimer_mode mode)
+static int __sched do_nanosleep(struct sleep_hrtimer *t, enum hrtimer_mode mode)
 {
-        set_current_state(TASK_INTERRUPTIBLE);
+        t->timer.function = nanosleep_wakeup;
+        t->task = current;
+        t->expired = 0;
+
+        do {
+                set_current_state(TASK_INTERRUPTIBLE);
+                hrtimer_start(&t->timer, t->timer.expires, mode);
+
+                schedule();
+
+                if (unlikely(!t->expired)) {
+                        hrtimer_cancel(&t->timer);
+                        mode = HRTIMER_ABS;
+                }
+        } while (!t->expired && !signal_pending(current));
 
-        return schedule_hrtimer(timer, mode);
+        return t->expired;
 }
 
 static long __sched nanosleep_restart(struct restart_block *restart)
 {
+        struct sleep_hrtimer t;
         struct timespec __user *rmtp;
         struct timespec tu;
-        void *rfn_save = restart->fn;
-        struct hrtimer timer;
-        ktime_t rem;
+        ktime_t time;
 
         restart->fn = do_no_restart_syscall;
 
-        hrtimer_init(&timer, (clockid_t) restart->arg3, HRTIMER_ABS);
-
-        timer.expires.tv64 = ((u64)restart->arg1 << 32) | (u64) restart->arg0;
-
-        rem = schedule_hrtimer_interruptible(&timer, HRTIMER_ABS);
+        hrtimer_init(&t.timer, restart->arg3, HRTIMER_ABS);
+        t.timer.expires.tv64 = ((u64)restart->arg1 << 32) | (u64) restart->arg0;
 
-        if (rem.tv64 <= 0)
+        if (do_nanosleep(&t, HRTIMER_ABS))
                 return 0;
 
         rmtp = (struct timespec __user *) restart->arg2;
-        tu = ktime_to_timespec(rem);
-        if (rmtp && copy_to_user(rmtp, &tu, sizeof(tu)))
-                return -EFAULT;
+        if (rmtp) {
+                time = ktime_sub(t.timer.expires, t.timer.base->get_time());
+                if (time.tv64 <= 0)
+                        return 0;
+                tu = ktime_to_timespec(time);
+                if (copy_to_user(rmtp, &tu, sizeof(tu)))
+                        return -EFAULT;
+        }
 
-        restart->fn = rfn_save;
+        restart->fn = nanosleep_restart;
 
         /* The other values in restart are already filled in */
         return -ERESTART_RESTARTBLOCK;
@@ -731,33 +729,34 @@ long hrtimer_nanosleep(struct timespec *rqtp, struct timespec __user *rmtp,
                        const enum hrtimer_mode mode, const clockid_t clockid)
 {
         struct restart_block *restart;
-        struct hrtimer timer;
+        struct sleep_hrtimer t;
         struct timespec tu;
         ktime_t rem;
 
-        hrtimer_init(&timer, clockid, mode);
-
-        timer.expires = timespec_to_ktime(*rqtp);
-
-        rem = schedule_hrtimer_interruptible(&timer, mode);
-        if (rem.tv64 <= 0)
+        hrtimer_init(&t.timer, clockid, mode);
+        t.timer.expires = timespec_to_ktime(*rqtp);
+        if (do_nanosleep(&t, mode))
                 return 0;
 
         /* Absolute timers do not update the rmtp value and restart: */
         if (mode == HRTIMER_ABS)
                 return -ERESTARTNOHAND;
 
-        tu = ktime_to_timespec(rem);
-
-        if (rmtp && copy_to_user(rmtp, &tu, sizeof(tu)))
-                return -EFAULT;
+        if (rmtp) {
+                rem = ktime_sub(t.timer.expires, t.timer.base->get_time());
+                if (rem.tv64 <= 0)
+                        return 0;
+                tu = ktime_to_timespec(rem);
+                if (copy_to_user(rmtp, &tu, sizeof(tu)))
+                        return -EFAULT;
+        }
 
         restart = &current_thread_info()->restart_block;
         restart->fn = nanosleep_restart;
-        restart->arg0 = timer.expires.tv64 & 0xFFFFFFFF;
-        restart->arg1 = timer.expires.tv64 >> 32;
+        restart->arg0 = t.timer.expires.tv64 & 0xFFFFFFFF;
+        restart->arg1 = t.timer.expires.tv64 >> 32;
         restart->arg2 = (unsigned long) rmtp;
-        restart->arg3 = (unsigned long) timer.base->index;
+        restart->arg3 = (unsigned long) t.timer.base->index;
 
         return -ERESTART_RESTARTBLOCK;
 }