drm/i915: Add unique id to the request structure for debugging

For debugging purposes, it is useful to be able to uniquely identify a given
request structure as it works its way through the system. This becomes
especially tricky once the seqno value is lazily allocated as then the request
has nothing but its pointer to identify it for much of its life.

Change-Id: Ie76b2268b940467f4cdf5a4ba6f5a54cbb96445d
For: VIZ-4377
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Thomas Daniel <Thomas.Daniel@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -1787,6 +1787,8 @@ struct drm_i915_private {
 		void (*stop_ring)(struct intel_engine_cs *ring);
 	} gt;
 
+	uint32_t request_uniq;
+
 	/*
 	 * NOTE: This is the dri1/ums dungeon, don't add stuff here. Your patch
 	 * will be rejected. Instead look for a better place.
@@ -2019,6 +2021,8 @@ struct drm_i915_gem_request {
 	struct drm_i915_file_private *file_priv;
 	/** file_priv list entry for this request */
 	struct list_head client_list;
+
+	uint32_t uniq;
 };
 
 void i915_gem_request_free(struct kref *req_ref);

drivers/gpu/drm/i915/intel_lrc.c

@@ -880,6 +880,7 @@ static int logical_ring_alloc_request(struct intel_engine_cs *ring,
 				      struct intel_context *ctx)
 {
 	struct drm_i915_gem_request *request;
+	struct drm_i915_private *dev_private = ring->dev->dev_private;
 	int ret;
 
 	if (ring->outstanding_lazy_request)
@@ -899,6 +900,7 @@ static int logical_ring_alloc_request(struct intel_engine_cs *ring,
 
 	kref_init(&request->ref);
 	request->ring = ring;
+	request->uniq = dev_private->request_uniq++;
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -2028,6 +2028,7 @@ intel_ring_alloc_request(struct intel_engine_cs *ring)
 {
 	int ret;
 	struct drm_i915_gem_request *request;
+	struct drm_i915_private *dev_private = ring->dev->dev_private;
 
 	if (ring->outstanding_lazy_request)
 		return 0;
@@ -2038,6 +2039,7 @@ intel_ring_alloc_request(struct intel_engine_cs *ring)
 
 	kref_init(&request->ref);
 	request->ring = ring;
+	request->uniq = dev_private->request_uniq++;
 
 	ret = i915_gem_get_seqno(ring->dev, &request->seqno);
 	if (ret) {