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Commit 675d9ad7 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Track requests inside each intel_ring 



By tracking each request occupying space inside an individual
intel_ring, we can greatly simplify the logic of tracking available
space and not worry about other timelines. (Each ring is an ordered
timeline of committed requests.)

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarJoonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470293567-10811-17-git-send-email-chris@chris-wilson.co.uk
parent fa545cbf

drivers/gpu/drm/i915/i915_gem_request.c

+2 −0
Original line number Diff line number Diff line
@@ -180,6 +180,7 @@ static void i915_gem_request_retire(struct drm_i915_gem_request *request) 
	 * Note this requires that we are always called in request

	 * completion order.

	 */

	list_del(&request->ring_link);

	request->ring->last_retired_head = request->postfix;



	/* Walk through the active list, calling retire on each. This allows
@@ -487,6 +488,7 @@ void __i915_add_request(struct drm_i915_gem_request *request, 
	request->previous_seqno = engine->last_submitted_seqno;

	smp_store_mb(engine->last_submitted_seqno, request->fence.seqno);

	list_add_tail(&request->link, &engine->request_list);

	list_add_tail(&request->ring_link, &ring->request_list);



	/* Record the position of the start of the request so that

	 * should we detect the updated seqno part-way through the

drivers/gpu/drm/i915/i915_gem_request.h

+3 −0
Original line number Diff line number Diff line
@@ -109,6 +109,9 @@ struct drm_i915_gem_request { 
	/** engine->request_list entry for this request */

	struct list_head link;



	/** ring->request_list entry for this request */

	struct list_head ring_link;



	struct drm_i915_file_private *file_priv;

	/** file_priv list entry for this request */

	struct list_head client_list;

drivers/gpu/drm/i915/intel_ringbuffer.c

+4 −11
Original line number Diff line number Diff line
@@ -2046,6 +2046,8 @@ intel_engine_create_ring(struct intel_engine_cs *engine, int size) 
	ring->engine = engine;

	list_add(&ring->link, &engine->buffers);



	INIT_LIST_HEAD(&ring->request_list);



	ring->size = size;

	/* Workaround an erratum on the i830 which causes a hang if

	 * the TAIL pointer points to within the last 2 cachelines
@@ -2266,7 +2268,6 @@ int intel_ring_alloc_request_extras(struct drm_i915_gem_request *request) 
static int wait_for_space(struct drm_i915_gem_request *req, int bytes)

{

	struct intel_ring *ring = req->ring;

	struct intel_engine_cs *engine = req->engine;

	struct drm_i915_gem_request *target;



	intel_ring_update_space(ring);
@@ -2284,17 +2285,9 @@ static int wait_for_space(struct drm_i915_gem_request *req, int bytes) 
	 */

	GEM_BUG_ON(!req->reserved_space);



	list_for_each_entry(target, &engine->request_list, link) {

	list_for_each_entry(target, &ring->request_list, ring_link) {

		unsigned space;



		/*

		 * The request queue is per-engine, so can contain requests

		 * from multiple ringbuffers. Here, we must ignore any that

		 * aren't from the ringbuffer we're considering.

		 */

		if (target->ring != ring)

			continue;



		/* Would completion of this request free enough space? */

		space = __intel_ring_space(target->postfix, ring->tail,

					   ring->size);
@@ -2302,7 +2295,7 @@ static int wait_for_space(struct drm_i915_gem_request *req, int bytes) 
			break;

	}



	if (WARN_ON(&target->link == &engine->request_list))

	if (WARN_ON(&target->ring_link == &ring->request_list))

		return -ENOSPC;



	return i915_wait_request(target);

drivers/gpu/drm/i915/intel_ringbuffer.h

+2 −0
Original line number Diff line number Diff line
@@ -90,6 +90,8 @@ struct intel_ring { 
	struct intel_engine_cs *engine;

	struct list_head link;



	struct list_head request_list;



	u32 head;

	u32 tail;

	int space;