drm: add vblank event trace point

Emit a trace point for vblank events.  This can be helpful for mapping
drawing activity against the vblank frequency and period.

Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/drm_trace.h

@@ -0,0 +1,37 @@
+#if !defined(_DRM_TRACE_H_) || defined(TRACE_HEADER_MULTI_READ)
+#define _DRM_TRACE_H_
+
+#include <linux/stringify.h>
+#include <linux/types.h>
+#include <linux/tracepoint.h>
+
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM drm
+#define TRACE_SYSTEM_STRING __stringify(TRACE_SYSTEM)
+#define TRACE_INCLUDE_FILE drm_trace
+
+TRACE_EVENT(drm_vblank_event,
+
+	TP_PROTO(int crtc, unsigned int seq),
+
+	TP_ARGS(crtc, seq),
+
+	TP_STRUCT__entry(
+		__field(int, crtc)
+		__field(unsigned int, seq)
+		),
+
+	TP_fast_assign(
+		__entry->crtc = crtc;
+		__entry->seq = seq;
+		),
+
+	TP_printk("crtc=%d, seq=%d", __entry->crtc, __entry->seq)
+);
+
+#endif /* _DRM_TRACE_H_ */
+
+/* This part must be outside protection */
+#undef TRACE_INCLUDE_PATH
+#define TRACE_INCLUDE_PATH .
+#include <trace/define_trace.h>