hrtimer: add support for starting timers on remote CPUs

This depends on the ability to send the special 'pull_timers' IPI
even with IRQs disabled.

2 files changed, 22 insertions, 0 deletions

diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index 7a9398e197..4f45c83151 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -200,6 +200,19 @@ struct hrtimer_cpu_base {
         struct list_head                cb_pending;
         unsigned long                   nr_events;
 #endif
+        struct list_head                to_pull;
+};
+
+#define HRTIMER_START_ON_INACTIVE       0
+#define HRTIMER_START_ON_QUEUED         1
+#define HRTIMER_START_ON_PROCESSED      2
+
+struct hrtimer_start_on_info {
+        struct list_head        list;
+        struct hrtimer*         timer;
+        ktime_t                 time;
+        enum hrtimer_mode       mode;
+        atomic_t                state;
 };
 
 #ifdef CONFIG_HIGH_RES_TIMERS
@@ -262,6 +275,9 @@ extern void hrtimer_init(struct hrtimer *timer, clockid_t which_clock,
 /* Basic timer operations: */
 extern int hrtimer_start(struct hrtimer *timer, ktime_t tim,
                          const enum hrtimer_mode mode);
+extern int hrtimer_start_on(int cpu, struct hrtimer_start_on_info* info,
+                            struct hrtimer *timer, ktime_t time,
+                            const enum hrtimer_mode mode);
 extern int hrtimer_cancel(struct hrtimer *timer);
 extern int hrtimer_try_to_cancel(struct hrtimer *timer);
 
diff --git a/include/linux/smp.h b/include/linux/smp.h
index c25e66bcec..84df090ce4 100644
--- a/include/linux/smp.h
+++ b/include/linux/smp.h
@@ -35,6 +35,12 @@ extern void smp_send_reschedule(int cpu);
 
 
 /*
+ * sends a 'pull timers' event to another CPU:
+ */
+extern void smp_send_pull_timers(int cpu);
+
+
+/*
  * Prepare machine for booting other CPUs.
  */
 extern void smp_prepare_cpus(unsigned int max_cpus);