From a7e02199ae430c0b41ee2b3079ccbbaff2393baf Mon Sep 17 00:00:00 2001 From: Alex Dai Date: Wed, 16 Dec 2015 11:45:55 -0800 Subject: [PATCH] drm/i915/guc: Move GuC wq_check_space to alloc_request_extras Split GuC work queue space checking from submission and move it to ring_alloc_request_extras. The reason is that failure in later i915_add_request() won't be handled. In the case timeout happens, driver can return early in order to handle the error. v1: Move wq_reserve_space to ring_reserve_space v2: Move wq_reserve_space to alloc_request_extras (Chris Wilson) v3: The work queue head pointer is cached by driver now. So we can quickly return if space is available. s/reserve/check/g (Dave Gordon) v4: Update cached wq head after ring doorbell; check wq space before ring doorbell in case unexpected error happens; call wq space check only when GuC submission is enabled. (Dave Gordon) Signed-off-by: Alex Dai Link: http://patchwork.freedesktop.org/patch/msgid/1450295155-10050-1-git-send-email-yu.dai@intel.com Reviewed-by: Dave Gordon Signed-off-by: Daniel Vetter --- drivers/gpu/drm/i915/i915_guc_submission.c | 39 +++++++++++++--------- drivers/gpu/drm/i915/intel_guc.h | 2 ++ drivers/gpu/drm/i915/intel_lrc.c | 13 ++++++++ 3 files changed, 39 insertions(+), 15 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c index 9cc3b8474dae..8b00f4619b1e 100644 --- a/drivers/gpu/drm/i915/i915_guc_submission.c +++ b/drivers/gpu/drm/i915/i915_guc_submission.c @@ -244,6 +244,9 @@ static int guc_ring_doorbell(struct i915_guc_client *gc) db_exc.cookie = 1; } + /* Finally, update the cached copy of the GuC's WQ head */ + gc->wq_head = desc->head; + kunmap_atomic(base); return ret; } @@ -469,28 +472,30 @@ static void guc_fini_ctx_desc(struct intel_guc *guc, sizeof(desc) * client->ctx_index); } -/* Get valid workqueue item and return it back to offset */ -static int guc_get_workqueue_space(struct i915_guc_client *gc, u32 *offset) +int i915_guc_wq_check_space(struct i915_guc_client *gc) { struct guc_process_desc *desc; void *base; u32 size = sizeof(struct guc_wq_item); int ret = -ETIMEDOUT, timeout_counter = 200; + if (!gc) + return 0; + + /* Quickly return if wq space is available since last time we cache the + * head position. */ + if (CIRC_SPACE(gc->wq_tail, gc->wq_head, gc->wq_size) >= size) + return 0; + base = kmap_atomic(i915_gem_object_get_page(gc->client_obj, 0)); desc = base + gc->proc_desc_offset; while (timeout_counter-- > 0) { - if (CIRC_SPACE(gc->wq_tail, desc->head, gc->wq_size) >= size) { - *offset = gc->wq_tail; + gc->wq_head = desc->head; - /* advance the tail for next workqueue item */ - gc->wq_tail += size; - gc->wq_tail &= gc->wq_size - 1; - - /* this will break the loop */ - timeout_counter = 0; + if (CIRC_SPACE(gc->wq_tail, gc->wq_head, gc->wq_size) >= size) { ret = 0; + break; } if (timeout_counter) @@ -508,12 +513,16 @@ static int guc_add_workqueue_item(struct i915_guc_client *gc, enum intel_ring_id ring_id = rq->ring->id; struct guc_wq_item *wqi; void *base; - u32 tail, wq_len, wq_off = 0; - int ret; + u32 tail, wq_len, wq_off, space; + + space = CIRC_SPACE(gc->wq_tail, gc->wq_head, gc->wq_size); + if (WARN_ON(space < sizeof(struct guc_wq_item))) + return -ENOSPC; /* shouldn't happen */ - ret = guc_get_workqueue_space(gc, &wq_off); - if (ret) - return ret; + /* postincrement WQ tail for next time */ + wq_off = gc->wq_tail; + gc->wq_tail += sizeof(struct guc_wq_item); + gc->wq_tail &= gc->wq_size - 1; /* For now workqueue item is 4 DWs; workqueue buffer is 2 pages. So we * should not have the case where structure wqi is across page, neither diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h index 822952235dcf..e8612c9afbc9 100644 --- a/drivers/gpu/drm/i915/intel_guc.h +++ b/drivers/gpu/drm/i915/intel_guc.h @@ -43,6 +43,7 @@ struct i915_guc_client { uint32_t wq_offset; uint32_t wq_size; uint32_t wq_tail; + uint32_t wq_head; /* GuC submission statistics & status */ uint64_t submissions[I915_NUM_RINGS]; @@ -122,5 +123,6 @@ int i915_guc_submit(struct i915_guc_client *client, struct drm_i915_gem_request *rq); void i915_guc_submission_disable(struct drm_device *dev); void i915_guc_submission_fini(struct drm_device *dev); +int i915_guc_wq_check_space(struct i915_guc_client *client); #endif diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c index 973487a73be1..e09505827394 100644 --- a/drivers/gpu/drm/i915/intel_lrc.c +++ b/drivers/gpu/drm/i915/intel_lrc.c @@ -670,6 +670,19 @@ int intel_logical_ring_alloc_request_extras(struct drm_i915_gem_request *request return ret; } + if (i915.enable_guc_submission) { + /* + * Check that the GuC has space for the request before + * going any further, as the i915_add_request() call + * later on mustn't fail ... + */ + struct intel_guc *guc = &request->i915->guc; + + ret = i915_guc_wq_check_space(guc->execbuf_client); + if (ret) + return ret; + } + return 0; } -- 2.20.1