1 files changed, 235 insertions, 25 deletions

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index fca93025ab51..37f9279192a9 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -21,22 +21,72 @@
 #include <linux/list.h>
 #include <linux/wait.h>
 
+struct hrtimer_clock_base;
+struct hrtimer_cpu_base;
+
 /*
  * Mode arguments of xxx_hrtimer functions:
  */
 enum hrtimer_mode {
-        HRTIMER_ABS,    /* Time value is absolute */
-        HRTIMER_REL,    /* Time value is relative to now */
+        HRTIMER_MODE_ABS,       /* Time value is absolute */
+        HRTIMER_MODE_REL,       /* Time value is relative to now */
 };
 
+/*
+ * Return values for the callback function
+ */
 enum hrtimer_restart {
-        HRTIMER_NORESTART,
-        HRTIMER_RESTART,
+        HRTIMER_NORESTART,      /* Timer is not restarted */
+        HRTIMER_RESTART,        /* Timer must be restarted */
 };
 
-#define HRTIMER_INACTIVE        ((void *)1UL)
+/*
+ * hrtimer callback modes:
+ *
+ *      HRTIMER_CB_SOFTIRQ:             Callback must run in softirq context
+ *      HRTIMER_CB_IRQSAFE:             Callback may run in hardirq context
+ *      HRTIMER_CB_IRQSAFE_NO_RESTART:  Callback may run in hardirq context and
+ *                                      does not restart the timer
+ *      HRTIMER_CB_IRQSAFE_NO_SOFTIRQ:  Callback must run in softirq context
+ *                                      Special mode for tick emultation
+ */
+enum hrtimer_cb_mode {
+        HRTIMER_CB_SOFTIRQ,
+        HRTIMER_CB_IRQSAFE,
+        HRTIMER_CB_IRQSAFE_NO_RESTART,
+        HRTIMER_CB_IRQSAFE_NO_SOFTIRQ,
+};
 
-struct hrtimer_base;
+/*
+ * Values to track state of the timer
+ *
+ * Possible states:
+ *
+ * 0x00         inactive
+ * 0x01         enqueued into rbtree
+ * 0x02         callback function running
+ * 0x04         callback pending (high resolution mode)
+ *
+ * Special case:
+ * 0x03         callback function running and enqueued
+ *              (was requeued on another CPU)
+ * The "callback function running and enqueued" status is only possible on
+ * SMP. It happens for example when a posix timer expired and the callback
+ * queued a signal. Between dropping the lock which protects the posix timer
+ * and reacquiring the base lock of the hrtimer, another CPU can deliver the
+ * signal and rearm the timer. We have to preserve the callback running state,
+ * as otherwise the timer could be removed before the softirq code finishes the
+ * the handling of the timer.
+ *
+ * The HRTIMER_STATE_ENQUEUE bit is always or'ed to the current state to
+ * preserve the HRTIMER_STATE_CALLBACK bit in the above scenario.
+ *
+ * All state transitions are protected by cpu_base->lock.
+ */
+#define HRTIMER_STATE_INACTIVE  0x00
+#define HRTIMER_STATE_ENQUEUED  0x01
+#define HRTIMER_STATE_CALLBACK  0x02
+#define HRTIMER_STATE_PENDING   0x04
 
 /**
  * struct hrtimer - the basic hrtimer structure
@@ -46,14 +96,34 @@ struct hrtimer_base;
  *              which the timer is based.
  * @function:   timer expiry callback function
  * @base:       pointer to the timer base (per cpu and per clock)
+ * @state:      state information (See bit values above)
+ * @cb_mode:    high resolution timer feature to select the callback execution
+ *               mode
+ * @cb_entry:   list head to enqueue an expired timer into the callback list
+ * @start_site: timer statistics field to store the site where the timer
+ *              was started
+ * @start_comm: timer statistics field to store the name of the process which
+ *              started the timer
+ * @start_pid: timer statistics field to store the pid of the task which
+ *              started the timer
  *
- * The hrtimer structure must be initialized by init_hrtimer_#CLOCKTYPE()
+ * The hrtimer structure must be initialized by hrtimer_init()
  */
 struct hrtimer {
-        struct rb_node          node;
-        ktime_t                 expires;
-        int                     (*function)(struct hrtimer *);
-        struct hrtimer_base     *base;
+        struct rb_node                  node;
+        ktime_t                         expires;
+        enum hrtimer_restart            (*function)(struct hrtimer *);
+        struct hrtimer_clock_base       *base;
+        unsigned long                   state;
+#ifdef CONFIG_HIGH_RES_TIMERS
+        enum hrtimer_cb_mode            cb_mode;
+        struct list_head                cb_entry;
+#endif
+#ifdef CONFIG_TIMER_STATS
+        void                            *start_site;
+        char                            start_comm[16];
+        int                             start_pid;
+#endif
 };
 
 /**
@@ -70,37 +140,114 @@ struct hrtimer_sleeper {
 
 /**
  * struct hrtimer_base - the timer base for a specific clock
- * @index:              clock type index for per_cpu support when moving a timer
- *                      to a base on another cpu.
- * @lock:               lock protecting the base and associated timers
+ * @index:              clock type index for per_cpu support when moving a
+ *                      timer to a base on another cpu.
  * @active:             red black tree root node for the active timers
  * @first:              pointer to the timer node which expires first
  * @resolution:         the resolution of the clock, in nanoseconds
  * @get_time:           function to retrieve the current time of the clock
  * @get_softirq_time:   function to retrieve the current time from the softirq
- * @curr_timer:         the timer which is executing a callback right now
  * @softirq_time:       the time when running the hrtimer queue in the softirq
- * @lock_key:           the lock_class_key for use with lockdep
+ * @cb_pending:         list of timers where the callback is pending
+ * @offset:             offset of this clock to the monotonic base
+ * @reprogram:          function to reprogram the timer event
  */
-struct hrtimer_base {
+struct hrtimer_clock_base {
+        struct hrtimer_cpu_base *cpu_base;
         clockid_t               index;
-        spinlock_t              lock;
         struct rb_root          active;
         struct rb_node          *first;
         ktime_t                 resolution;
         ktime_t                 (*get_time)(void);
         ktime_t                 (*get_softirq_time)(void);
-        struct hrtimer          *curr_timer;
         ktime_t                 softirq_time;
-        struct lock_class_key lock_key;
+#ifdef CONFIG_HIGH_RES_TIMERS
+        ktime_t                 offset;
+        int                     (*reprogram)(struct hrtimer *t,
+                                             struct hrtimer_clock_base *b,
+                                             ktime_t n);
+#endif
+};
+
+#define HRTIMER_MAX_CLOCK_BASES 2
+
+/*
+ * struct hrtimer_cpu_base - the per cpu clock bases
+ * @lock:               lock protecting the base and associated clock bases
+ *                      and timers
+ * @lock_key:           the lock_class_key for use with lockdep
+ * @clock_base:         array of clock bases for this cpu
+ * @curr_timer:         the timer which is executing a callback right now
+ * @expires_next:       absolute time of the next event which was scheduled
+ *                      via clock_set_next_event()
+ * @hres_active:        State of high resolution mode
+ * @check_clocks:       Indictator, when set evaluate time source and clock
+ *                      event devices whether high resolution mode can be
+ *                      activated.
+ * @cb_pending:         Expired timers are moved from the rbtree to this
+ *                      list in the timer interrupt. The list is processed
+ *                      in the softirq.
+ * @nr_events:          Total number of timer interrupt events
+ */
+struct hrtimer_cpu_base {
+        spinlock_t                      lock;
+        struct lock_class_key           lock_key;
+        struct hrtimer_clock_base       clock_base[HRTIMER_MAX_CLOCK_BASES];
+#ifdef CONFIG_HIGH_RES_TIMERS
+        ktime_t                         expires_next;
+        int                             hres_active;
+        struct list_head                cb_pending;
+        unsigned long                   nr_events;
+#endif
 };
 
+#ifdef CONFIG_HIGH_RES_TIMERS
+struct clock_event_device;
+
+extern void clock_was_set(void);
+extern void hrtimer_interrupt(struct clock_event_device *dev);
+
+/*
+ * In high resolution mode the time reference must be read accurate
+ */
+static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
+{
+        return timer->base->get_time();
+}
+
+/*
+ * The resolution of the clocks. The resolution value is returned in
+ * the clock_getres() system call to give application programmers an
+ * idea of the (in)accuracy of timers. Timer values are rounded up to
+ * this resolution values.
+ */
+# define KTIME_HIGH_RES         (ktime_t) { .tv64 = 1 }
+# define KTIME_MONOTONIC_RES    KTIME_HIGH_RES
+
+#else
+
+# 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.
  */
-#define clock_was_set()         do { } while (0)
+static inline void clock_was_set(void) { }
+
+/*
+ * In non high resolution mode the time reference is taken from
+ * the base softirq time variable.
+ */
+static inline ktime_t hrtimer_cb_get_time(struct hrtimer *timer)
+{
+        return timer->base->softirq_time;
+}
+
+#endif
+
+extern ktime_t ktime_get(void);
+extern ktime_t ktime_get_real(void);
 
 /* Exported timer functions: */
 
@@ -114,19 +261,33 @@ extern int hrtimer_start(struct hrtimer *timer, ktime_t tim,
 extern int hrtimer_cancel(struct hrtimer *timer);
 extern int hrtimer_try_to_cancel(struct hrtimer *timer);
 
-#define hrtimer_restart(timer) hrtimer_start((timer), (timer)->expires, HRTIMER_ABS)
+static inline int hrtimer_restart(struct hrtimer *timer)
+{
+        return hrtimer_start(timer, timer->expires, HRTIMER_MODE_ABS);
+}
 
 /* Query timers: */
 extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
 extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
 
-#ifdef CONFIG_NO_IDLE_HZ
 extern ktime_t hrtimer_get_next_event(void);
-#endif
 
+/*
+ * A timer is active, when it is enqueued into the rbtree or the callback
+ * function is running.
+ */
 static inline int hrtimer_active(const struct hrtimer *timer)
 {
-        return rb_parent(&timer->node) != &timer->node;
+        return timer->state != HRTIMER_STATE_INACTIVE;
+}
+
+/*
+ * Helper function to check, whether the timer is on one of the queues
+ */
+static inline int hrtimer_is_queued(struct hrtimer *timer)
+{
+        return timer->state &
+                (HRTIMER_STATE_ENQUEUED | HRTIMER_STATE_PENDING);
 }
 
 /* Forward a hrtimer so it expires after now: */
@@ -149,4 +310,53 @@ extern void hrtimer_run_queues(void);
 /* Bootup initialization: */
 extern void __init hrtimers_init(void);
 
+#if BITS_PER_LONG < 64
+extern unsigned long ktime_divns(const ktime_t kt, s64 div);
+#else /* BITS_PER_LONG < 64 */
+# define ktime_divns(kt, div)           (unsigned long)((kt).tv64 / (div))
+#endif
+
+/* Show pending timers: */
+extern void sysrq_timer_list_show(void);
+
+/*
+ * Timer-statistics info:
+ */
+#ifdef CONFIG_TIMER_STATS
+
+extern void timer_stats_update_stats(void *timer, pid_t pid, void *startf,
+                                     void *timerf, char * comm);
+
+static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
+{
+        timer_stats_update_stats(timer, timer->start_pid, timer->start_site,
+                                 timer->function, timer->start_comm);
+}
+
+extern void __timer_stats_hrtimer_set_start_info(struct hrtimer *timer,
+                                                 void *addr);
+
+static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
+{
+        __timer_stats_hrtimer_set_start_info(timer, __builtin_return_address(0));
+}
+
+static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
+{
+        timer->start_site = NULL;
+}
+#else
+static inline void timer_stats_account_hrtimer(struct hrtimer *timer)
+{
+}
+
+static inline void timer_stats_hrtimer_set_start_info(struct hrtimer *timer)
+{
+}
+
+static inline void timer_stats_hrtimer_clear_start_info(struct hrtimer *timer)
+{
+}
+#endif
+
 #endif