perf: Generalize some arch callchain code

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

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index c772a3d4000d85a1fc0691626d3ff26c90bb1c12..02efde6c87980cb657d03a90834f7dcbe7ed66bf 100644 (file)
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -2937,13 +2937,49 @@ void perf_event_do_pending(void)
        __perf_pending_run();
 }
 
+DEFINE_PER_CPU(struct perf_callchain_entry, perf_callchain_entry);
+
 /*
  * Callchain support -- arch specific
  */
 
-__weak struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
+__weak struct perf_callchain_entry *perf_callchain_buffer(void)
 {
-       return NULL;
+       return &__get_cpu_var(perf_callchain_entry);
+}
+
+__weak void perf_callchain_kernel(struct perf_callchain_entry *entry,
+                                 struct pt_regs *regs)
+{
+}
+
+__weak void perf_callchain_user(struct perf_callchain_entry *entry,
+                               struct pt_regs *regs)
+{
+}
+
+static struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
+{
+       struct perf_callchain_entry *entry;
+
+       entry = perf_callchain_buffer();
+       if (!entry)
+               return NULL;
+
+       entry->nr = 0;
+
+       if (!user_mode(regs)) {
+               perf_callchain_kernel(entry, regs);
+               if (current->mm)
+                       regs = task_pt_regs(current);
+               else
+                       regs = NULL;
+       }
+
+       if (regs)
+               perf_callchain_user(entry, regs);
+
+       return entry;
 }