From 98e1bd4ae68e0a122de21795c946ba36a8259f70 Mon Sep 17 00:00:00 2001 From: John Harrison Date: Fri, 13 Feb 2015 11:48:12 +0000 Subject: [PATCH] drm/i915: Cache ringbuf pointer in request structure In execlist mode, the ringbuf is a function of the ring and context whereas in legacy mode, it is derived from the ring alone. Thus the calculation required to determine the ringbuf pointer from the ring (and context) also needs to test execlist mode or not. This is messy. Further, the request structure holds a pointer to both the ring and the context for which it was created. Thus, given a request, it is possible to derive the ringbuf in either legacy or execlist mode. Hence it is necessary to pass just the request in to all the low level functions rather than some combination of request, ring, context and ringbuf. However, rather than recalculating it each time, it is much simpler to just cache the ringbuf pointer in the request structure itself. Caching the pointer means the calculation is done once at request creation time and all further code and simply read it directly from the request structure. OTC-Jira: VIZ-5115 Signed-off-by: John Harrison [danvet: Drop contentless comment in lrc alloc request entirely. And spelling fix in the commit message.] Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_drv.h | 3 ++- drivers/gpu/drm/i915/i915_gem.c | 14 +------------- drivers/gpu/drm/i915/intel_lrc.c | 5 +---- drivers/gpu/drm/i915/intel_ringbuffer.c | 1 + 4 files changed, 5 insertions(+), 18 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index ba0f5b6..239a382c 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -2156,8 +2156,9 @@ struct drm_i915_gem_request { /** Position in the ringbuffer of the end of the whole request */ u32 tail; - /** Context related to this request */ + /** Context and ring buffer related to this request */ struct intel_context *ctx; + struct intel_ringbuffer *ringbuf; /** Batch buffer related to this request if any */ struct drm_i915_gem_object *batch_obj; diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index f28f0de..14ca4cd5 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2763,7 +2763,6 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring) while (!list_empty(&ring->request_list)) { struct drm_i915_gem_request *request; - struct intel_ringbuffer *ringbuf; request = list_first_entry(&ring->request_list, struct drm_i915_gem_request, @@ -2774,23 +2773,12 @@ i915_gem_retire_requests_ring(struct intel_engine_cs *ring) trace_i915_gem_request_retire(request); - /* This is one of the few common intersection points - * between legacy ringbuffer submission and execlists: - * we need to tell them apart in order to find the correct - * ringbuffer to which the request belongs to. - */ - if (i915.enable_execlists) { - struct intel_context *ctx = request->ctx; - ringbuf = ctx->engine[ring->id].ringbuf; - } else - ringbuf = ring->buffer; - /* We know the GPU must have read the request to have * sent us the seqno + interrupt, so use the position * of tail of the request to update the last known position * of the GPU head. */ - ringbuf->last_retired_head = request->postfix; + request->ringbuf->last_retired_head = request->postfix; i915_gem_free_request(request); } diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 09af288..a1a2a61 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -888,12 +888,9 @@ static int logical_ring_alloc_request(struct intel_engine_cs *ring, return ret; } - /* Hold a reference to the context this request belongs to - * (we will need it when the time comes to emit/retire the - * request). - */ request->ctx = ctx; i915_gem_context_reference(request->ctx); + request->ringbuf = ctx->engine[ring->id].ringbuf; ring->outstanding_lazy_request = request; return 0; diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 4a4a7ae..94dc98b 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -2230,6 +2230,7 @@ intel_ring_alloc_request(struct intel_engine_cs *ring) kref_init(&request->ref); request->ring = ring; + request->ringbuf = ring->buffer; request->uniq = dev_private->request_uniq++; ret = i915_gem_get_seqno(ring->dev, &request->seqno); -- 2.7.4