From 82352e908acd36d7244c75a008c9f27a2ced44d5 Mon Sep 17 00:00:00 2001 From: Tvrtko Ursulin Date: Fri, 15 Jan 2016 17:12:45 +0000 Subject: [PATCH] drm/i915: Cache LRC state page in the context LRC lifetime is well defined so we can cache the page pointing to the object backing store in the context in order to avoid walking over the object SG page list from the interrupt context without the big lock held. v2: Also cache the mapping. (Chris Wilson) v3: Unmap on the error path. v4: No need to cache the page. (Chris Wilson) v5: No need to dirty the page on unpin. (Chris Wilson) v6: kmap() cannot fail and use kmap_to_page to simplify unpin. (Chris Wilson) Signed-off-by: Tvrtko Ursulin Cc: Chris Wilson Cc: Dave Gordon Reviewed-by: Chris Wilson Link: http://patchwork.freedesktop.org/patch/msgid/1452877965-32042-1-git-send-email-tvrtko.ursulin@linux.intel.com --- drivers/gpu/drm/i915/i915_drv.h | 1 + drivers/gpu/drm/i915/intel_lrc.c | 39 +++++++++++++++++++++------------------ 2 files changed, 22 insertions(+), 18 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h index acff98b..af30148 100644 --- a/drivers/gpu/drm/i915/i915_drv.h +++ b/drivers/gpu/drm/i915/i915_drv.h @@ -890,6 +890,7 @@ struct intel_context { int pin_count; struct i915_vma *lrc_vma; u64 lrc_desc; + uint32_t *lrc_reg_state; } engine[I915_NUM_RINGS]; struct list_head link; diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 588cad58..faaf490 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -390,14 +390,7 @@ static int execlists_update_context(struct drm_i915_gem_request *rq) { struct intel_engine_cs *ring = rq->ring; struct i915_hw_ppgtt *ppgtt = rq->ctx->ppgtt; - struct drm_i915_gem_object *ctx_obj = rq->ctx->engine[ring->id].state; - struct page *page; - uint32_t *reg_state; - - BUG_ON(!ctx_obj); - - page = i915_gem_object_get_dirty_page(ctx_obj, LRC_STATE_PN); - reg_state = kmap_atomic(page); + uint32_t *reg_state = rq->ctx->engine[ring->id].lrc_reg_state; reg_state[CTX_RING_TAIL+1] = rq->tail; reg_state[CTX_RING_BUFFER_START+1] = rq->ringbuf->vma->node.start; @@ -414,8 +407,6 @@ static int execlists_update_context(struct drm_i915_gem_request *rq) ASSIGN_CTX_PDP(ppgtt, reg_state, 0); } - kunmap_atomic(reg_state); - return 0; } @@ -1067,6 +1058,7 @@ static int intel_lr_context_do_pin(struct intel_engine_cs *ring, struct drm_i915_private *dev_priv = dev->dev_private; struct drm_i915_gem_object *ctx_obj = ctx->engine[ring->id].state; struct intel_ringbuffer *ringbuf = ctx->engine[ring->id].ringbuf; + struct page *lrc_state_page; int ret; WARN_ON(!mutex_is_locked(&ring->dev->struct_mutex)); @@ -1076,12 +1068,19 @@ static int intel_lr_context_do_pin(struct intel_engine_cs *ring, if (ret) return ret; + lrc_state_page = i915_gem_object_get_dirty_page(ctx_obj, LRC_STATE_PN); + if (WARN_ON(!lrc_state_page)) { + ret = -ENODEV; + goto unpin_ctx_obj; + } + ret = intel_pin_and_map_ringbuffer_obj(ring->dev, ringbuf); if (ret) goto unpin_ctx_obj; ctx->engine[ring->id].lrc_vma = i915_gem_obj_to_ggtt(ctx_obj); intel_lr_context_descriptor_update(ctx, ring); + ctx->engine[ring->id].lrc_reg_state = kmap(lrc_state_page); ctx_obj->dirty = true; /* Invalidate GuC TLB. */ @@ -1119,14 +1118,18 @@ void intel_lr_context_unpin(struct drm_i915_gem_request *rq) struct drm_i915_gem_object *ctx_obj = rq->ctx->engine[ring->id].state; struct intel_ringbuffer *ringbuf = rq->ringbuf; - if (ctx_obj) { - WARN_ON(!mutex_is_locked(&ring->dev->struct_mutex)); - if (--rq->ctx->engine[ring->id].pin_count == 0) { - intel_unpin_ringbuffer_obj(ringbuf); - i915_gem_object_ggtt_unpin(ctx_obj); - rq->ctx->engine[ring->id].lrc_vma = NULL; - rq->ctx->engine[ring->id].lrc_desc = 0; - } + WARN_ON(!mutex_is_locked(&ring->dev->struct_mutex)); + + if (!ctx_obj) + return; + + if (--rq->ctx->engine[ring->id].pin_count == 0) { + kunmap(kmap_to_page(rq->ctx->engine[ring->id].lrc_reg_state)); + intel_unpin_ringbuffer_obj(ringbuf); + i915_gem_object_ggtt_unpin(ctx_obj); + rq->ctx->engine[ring->id].lrc_vma = NULL; + rq->ctx->engine[ring->id].lrc_desc = 0; + rq->ctx->engine[ring->id].lrc_reg_state = NULL; } } -- 2.7.4