x86, hw-branch-tracer: add selftest

Add a selftest for the hw-branch-tracer.

Signed-off-by: Markus Metzger <markus.t.metzger@intel.com>
LKML-Reference: <20090313105027.A30183@sedona.ch.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 53 insertions, 0 deletions

diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c
index f907a2b29028..3c7b797d0d28 100644
--- a/kernel/trace/trace_selftest.c
+++ b/kernel/trace/trace_selftest.c
@@ -16,6 +16,7 @@ static inline int trace_valid_entry(struct trace_entry *entry)
         case TRACE_BRANCH:
         case TRACE_GRAPH_ENT:
         case TRACE_GRAPH_RET:
+        case TRACE_HW_BRANCHES:
                 return 1;
         }
         return 0;
@@ -691,3 +692,55 @@ trace_selftest_startup_branch(struct tracer *trace, struct trace_array *tr)
         return ret;
 }
 #endif /* CONFIG_BRANCH_TRACER */
+
+#ifdef CONFIG_HW_BRANCH_TRACER
+int
+trace_selftest_startup_hw_branches(struct tracer *trace,
+                                   struct trace_array *tr)
+{
+        unsigned long count;
+        int ret;
+        struct trace_iterator iter;
+        struct tracer tracer;
+
+        if (!trace->open) {
+                printk(KERN_CONT "missing open function...");
+                return -1;
+        }
+
+        ret = tracer_init(trace, tr);
+        if (ret) {
+                warn_failed_init_tracer(trace, ret);
+                return ret;
+        }
+
+        /*
+         * The hw-branch tracer needs to collect the trace from the various
+         * cpu trace buffers - before tracing is stopped.
+         */
+        memset(&iter, 0, sizeof(iter));
+        memcpy(&tracer, trace, sizeof(tracer));
+
+        iter.trace = &tracer;
+        iter.tr = tr;
+        iter.pos = -1;
+        mutex_init(&iter.mutex);
+
+        trace->open(&iter);
+
+        mutex_destroy(&iter.mutex);
+
+        tracing_stop();
+
+        ret = trace_test_buffer(tr, &count);
+        trace->reset(tr);
+        tracing_start();
+
+        if (!ret && !count) {
+                printk(KERN_CONT "no entries found..");
+                ret = -1;
+        }
+
+        return ret;
+}
+#endif /* CONFIG_HW_BRANCH_TRACER */