perf_counter: Rework the perf counter disable/enable

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

diff --git a/kernel/perf_counter.c b/kernel/perf_counter.c
index 985be0b662af93a371e9c41438d5e64b50536144..e814ff04d7ca0266c7f4fc44361149937d8d7df6 100644 (file)
--- a/kernel/perf_counter.c
+++ b/kernel/perf_counter.c
@@ -60,8 +60,9 @@ extern __weak const struct pmu *hw_perf_counter_init(struct perf_counter *counte
        return NULL;
 }
 
-u64 __weak hw_perf_save_disable(void)          { return 0; }
-void __weak hw_perf_restore(u64 ctrl)          { barrier(); }
+void __weak hw_perf_disable(void)              { barrier(); }
+void __weak hw_perf_enable(void)               { barrier(); }
+
 void __weak hw_perf_counter_setup(int cpu)     { barrier(); }
 int __weak hw_perf_group_sched_in(struct perf_counter *group_leader,
               struct perf_cpu_context *cpuctx,
@@ -72,6 +73,32 @@ int __weak hw_perf_group_sched_in(struct perf_counter *group_leader,
 
 void __weak perf_counter_print_debug(void)     { }
 
+static DEFINE_PER_CPU(int, disable_count);
+
+void __perf_disable(void)
+{
+       __get_cpu_var(disable_count)++;
+}
+
+bool __perf_enable(void)
+{
+       return !--__get_cpu_var(disable_count);
+}
+
+void perf_disable(void)
+{
+       __perf_disable();
+       hw_perf_disable();
+}
+EXPORT_SYMBOL_GPL(perf_disable); /* ACPI idle */
+
+void perf_enable(void)
+{
+       if (__perf_enable())
+               hw_perf_enable();
+}
+EXPORT_SYMBOL_GPL(perf_enable); /* ACPI idle */
+
 static void
 list_add_counter(struct perf_counter *counter, struct perf_counter_context *ctx)
 {
@@ -170,7 +197,6 @@ static void __perf_counter_remove_from_context(void *info)
        struct perf_counter *counter = info;
        struct perf_counter_context *ctx = counter->ctx;
        unsigned long flags;
-       u64 perf_flags;
 
        /*
         * If this is a task context, we need to check whether it is
@@ -191,9 +217,9 @@ static void __perf_counter_remove_from_context(void *info)
         * Protect the list operation against NMI by disabling the
         * counters on a global level. NOP for non NMI based counters.
         */
-       perf_flags = hw_perf_save_disable();
+       perf_disable();
        list_del_counter(counter, ctx);
-       hw_perf_restore(perf_flags);
+       perf_enable();
 
        if (!ctx->task) {
                /*
@@ -538,7 +564,6 @@ static void __perf_install_in_context(void *info)
        struct perf_counter *leader = counter->group_leader;
        int cpu = smp_processor_id();
        unsigned long flags;
-       u64 perf_flags;
        int err;
 
        /*
@@ -556,7 +581,7 @@ static void __perf_install_in_context(void *info)
         * Protect the list operation against NMI by disabling the
         * counters on a global level. NOP for non NMI based counters.
         */
-       perf_flags = hw_perf_save_disable();
+       perf_disable();
 
        add_counter_to_ctx(counter, ctx);
 
@@ -596,7 +621,7 @@ static void __perf_install_in_context(void *info)
                cpuctx->max_pertask--;
 
  unlock:
-       hw_perf_restore(perf_flags);
+       perf_enable();
 
        spin_unlock_irqrestore(&ctx->lock, flags);
 }
@@ -663,7 +688,6 @@ static void __perf_counter_enable(void *info)
        struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context);
        struct perf_counter_context *ctx = counter->ctx;
        struct perf_counter *leader = counter->group_leader;
-       unsigned long pmuflags;
        unsigned long flags;
        int err;
 
@@ -693,14 +717,14 @@ static void __perf_counter_enable(void *info)
        if (!group_can_go_on(counter, cpuctx, 1)) {
                err = -EEXIST;
        } else {
-               pmuflags = hw_perf_save_disable();
+               perf_disable();
                if (counter == leader)
                        err = group_sched_in(counter, cpuctx, ctx,
                                             smp_processor_id());
                else
                        err = counter_sched_in(counter, cpuctx, ctx,
                                               smp_processor_id());
-               hw_perf_restore(pmuflags);
+               perf_enable();
        }
 
        if (err) {
@@ -795,7 +819,6 @@ void __perf_counter_sched_out(struct perf_counter_context *ctx,
                              struct perf_cpu_context *cpuctx)
 {
        struct perf_counter *counter;
-       u64 flags;
 
        spin_lock(&ctx->lock);
        ctx->is_active = 0;
@@ -803,12 +826,12 @@ void __perf_counter_sched_out(struct perf_counter_context *ctx,
                goto out;
        update_context_time(ctx);
 
-       flags = hw_perf_save_disable();
+       perf_disable();
        if (ctx->nr_active) {
                list_for_each_entry(counter, &ctx->counter_list, list_entry)
                        group_sched_out(counter, cpuctx, ctx);
        }
-       hw_perf_restore(flags);
+       perf_enable();
  out:
        spin_unlock(&ctx->lock);
 }
@@ -860,7 +883,6 @@ __perf_counter_sched_in(struct perf_counter_context *ctx,
                        struct perf_cpu_context *cpuctx, int cpu)
 {
        struct perf_counter *counter;
-       u64 flags;
        int can_add_hw = 1;
 
        spin_lock(&ctx->lock);
@@ -870,7 +892,7 @@ __perf_counter_sched_in(struct perf_counter_context *ctx,
 
        ctx->timestamp = perf_clock();
 
-       flags = hw_perf_save_disable();
+       perf_disable();
 
        /*
         * First go through the list and put on any pinned groups
@@ -917,7 +939,7 @@ __perf_counter_sched_in(struct perf_counter_context *ctx,
                                can_add_hw = 0;
                }
        }
-       hw_perf_restore(flags);
+       perf_enable();
  out:
        spin_unlock(&ctx->lock);
 }
@@ -955,7 +977,6 @@ int perf_counter_task_disable(void)
        struct perf_counter_context *ctx = &curr->perf_counter_ctx;
        struct perf_counter *counter;
        unsigned long flags;
-       u64 perf_flags;
 
        if (likely(!ctx->nr_counters))
                return 0;
@@ -969,7 +990,7 @@ int perf_counter_task_disable(void)
        /*
         * Disable all the counters:
         */
-       perf_flags = hw_perf_save_disable();
+       perf_disable();
 
        list_for_each_entry(counter, &ctx->counter_list, list_entry) {
                if (counter->state != PERF_COUNTER_STATE_ERROR) {
@@ -978,7 +999,7 @@ int perf_counter_task_disable(void)
                }
        }
 
-       hw_perf_restore(perf_flags);
+       perf_enable();
 
        spin_unlock_irqrestore(&ctx->lock, flags);
 
@@ -991,7 +1012,6 @@ int perf_counter_task_enable(void)
        struct perf_counter_context *ctx = &curr->perf_counter_ctx;
        struct perf_counter *counter;
        unsigned long flags;
-       u64 perf_flags;
        int cpu;
 
        if (likely(!ctx->nr_counters))
@@ -1007,7 +1027,7 @@ int perf_counter_task_enable(void)
        /*
         * Disable all the counters:
         */
-       perf_flags = hw_perf_save_disable();
+       perf_disable();
 
        list_for_each_entry(counter, &ctx->counter_list, list_entry) {
                if (counter->state > PERF_COUNTER_STATE_OFF)
@@ -1017,7 +1037,7 @@ int perf_counter_task_enable(void)
                        ctx->time - counter->total_time_enabled;
                counter->hw_event.disabled = 0;
        }
-       hw_perf_restore(perf_flags);
+       perf_enable();
 
        spin_unlock(&ctx->lock);
 
@@ -1034,7 +1054,6 @@ int perf_counter_task_enable(void)
 static void rotate_ctx(struct perf_counter_context *ctx)
 {
        struct perf_counter *counter;
-       u64 perf_flags;
 
        if (!ctx->nr_counters)
                return;
@@ -1043,12 +1062,12 @@ static void rotate_ctx(struct perf_counter_context *ctx)
        /*
         * Rotate the first entry last (works just fine for group counters too):
         */
-       perf_flags = hw_perf_save_disable();
+       perf_disable();
        list_for_each_entry(counter, &ctx->counter_list, list_entry) {
                list_move_tail(&counter->list_entry, &ctx->counter_list);
                break;
        }
-       hw_perf_restore(perf_flags);
+       perf_enable();
 
        spin_unlock(&ctx->lock);
 }
@@ -3194,7 +3213,6 @@ __perf_counter_exit_task(struct task_struct *child,
        } else {
                struct perf_cpu_context *cpuctx;
                unsigned long flags;
-               u64 perf_flags;
 
                /*
                 * Disable and unlink this counter.
@@ -3203,7 +3221,7 @@ __perf_counter_exit_task(struct task_struct *child,
                 * could still be processing it:
                 */
                local_irq_save(flags);
-               perf_flags = hw_perf_save_disable();
+               perf_disable();
 
                cpuctx = &__get_cpu_var(perf_cpu_context);
 
@@ -3214,7 +3232,7 @@ __perf_counter_exit_task(struct task_struct *child,
 
                child_ctx->nr_counters--;
 
-               hw_perf_restore(perf_flags);
+               perf_enable();
                local_irq_restore(flags);
        }