irq_work: Add generic hardirq context callbacks

[mv-sheeva.git] / kernel / perf_event.c

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 634f86a4b2f93bb6df5d6fda71e69a7fed144402..99b9700e74d0ca693b4f03ce84d8b160571daab2 100644 (file)
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2206,12 +2206,11 @@ static void free_event_rcu(struct rcu_head *head)
        kfree(event);
 }
 
-static void perf_pending_sync(struct perf_event *event);
 static void perf_buffer_put(struct perf_buffer *buffer);
 
 static void free_event(struct perf_event *event)
 {
-       perf_pending_sync(event);
+       irq_work_sync(&event->pending);
 
        if (!event->parent) {
                atomic_dec(&nr_events);
@@ -3162,16 +3161,7 @@ void perf_event_wakeup(struct perf_event *event)
        }
 }
 
-/*
- * Pending wakeups
- *
- * Handle the case where we need to wakeup up from NMI (or rq->lock) context.
- *
- * The NMI bit means we cannot possibly take locks. Therefore, maintain a
- * single linked list and use cmpxchg() to add entries lockless.
- */
-
-static void perf_pending_event(struct perf_pending_entry *entry)
+static void perf_pending_event(struct irq_work *entry)
 {
        struct perf_event *event = container_of(entry,
                        struct perf_event, pending);
@@ -3187,89 +3177,6 @@ static void perf_pending_event(struct perf_pending_entry *entry)
        }
 }
 
-#define PENDING_TAIL ((struct perf_pending_entry *)-1UL)
-
-static DEFINE_PER_CPU(struct perf_pending_entry *, perf_pending_head) = {
-       PENDING_TAIL,
-};
-
-static void perf_pending_queue(struct perf_pending_entry *entry,
-                              void (*func)(struct perf_pending_entry *))
-{
-       struct perf_pending_entry **head;
-
-       if (cmpxchg(&entry->next, NULL, PENDING_TAIL) != NULL)
-               return;
-
-       entry->func = func;
-
-       head = &get_cpu_var(perf_pending_head);
-
-       do {
-               entry->next = *head;
-       } while (cmpxchg(head, entry->next, entry) != entry->next);
-
-       set_perf_event_pending();
-
-       put_cpu_var(perf_pending_head);
-}
-
-static int __perf_pending_run(void)
-{
-       struct perf_pending_entry *list;
-       int nr = 0;
-
-       list = xchg(&__get_cpu_var(perf_pending_head), PENDING_TAIL);
-       while (list != PENDING_TAIL) {
-               void (*func)(struct perf_pending_entry *);
-               struct perf_pending_entry *entry = list;
-
-               list = list->next;
-
-               func = entry->func;
-               entry->next = NULL;
-               /*
-                * Ensure we observe the unqueue before we issue the wakeup,
-                * so that we won't be waiting forever.
-                * -- see perf_not_pending().
-                */
-               smp_wmb();
-
-               func(entry);
-               nr++;
-       }
-
-       return nr;
-}
-
-static inline int perf_not_pending(struct perf_event *event)
-{
-       /*
-        * If we flush on whatever cpu we run, there is a chance we don't
-        * need to wait.
-        */
-       get_cpu();
-       __perf_pending_run();
-       put_cpu();
-
-       /*
-        * Ensure we see the proper queue state before going to sleep
-        * so that we do not miss the wakeup. -- see perf_pending_handle()
-        */
-       smp_rmb();
-       return event->pending.next == NULL;
-}
-
-static void perf_pending_sync(struct perf_event *event)
-{
-       wait_event(event->waitq, perf_not_pending(event));
-}
-
-void perf_event_do_pending(void)
-{
-       __perf_pending_run();
-}
-
 /*
  * We assume there is only KVM supporting the callbacks.
  * Later on, we might change it to a list if there is
@@ -3319,8 +3226,7 @@ static void perf_output_wakeup(struct perf_output_handle *handle)
 
        if (handle->nmi) {
                handle->event->pending_wakeup = 1;
-               perf_pending_queue(&handle->event->pending,
-                                  perf_pending_event);
+               irq_work_queue(&handle->event->pending);
        } else
                perf_event_wakeup(handle->event);
 }
@@ -4356,8 +4262,7 @@ static int __perf_event_overflow(struct perf_event *event, int nmi,
                event->pending_kill = POLL_HUP;
                if (nmi) {
                        event->pending_disable = 1;
-                       perf_pending_queue(&event->pending,
-                                          perf_pending_event);
+                       irq_work_queue(&event->pending);
                } else
                        perf_event_disable(event);
        }
@@ -5374,6 +5279,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
        INIT_LIST_HEAD(&event->event_entry);
        INIT_LIST_HEAD(&event->sibling_list);
        init_waitqueue_head(&event->waitq);
+       init_irq_work(&event->pending, perf_pending_event);
 
        mutex_init(&event->mmap_mutex);