From 0a31afbc0f87c734cb1688eb626ee9abee63d723 Mon Sep 17 00:00:00 2001 From: Dave Gordon Date: Fri, 13 May 2016 15:36:34 +0100 Subject: [PATCH] drm/i915/guc: rework guc_add_workqueue_item() Mostly little optimisations and future-proofing against code breakage. For instance, if the driver is correctly following the submission protocol, the "out of space" condition is impossible, so the previous runtime WARN_ON() is promoted to a GEM_BUG_ON() for a more dramatic effect in development and less impact in end-user systems. Similarly we can make alignment checking more stringent and replace other WARN_ON() conditions that don't relate to the runtime hardware state with either BUILD_BUG_ON() for compile-time-detectable issues, or GEM_BUG_ON() for logical "can't happen" errors. With those changes, we can convert it to void, as suggested by Chris Wilson, and update the calling code appropriately. v2: Note that we're now putting the request seqno in the "fence_id" field of each GuC-work-item, in case it turns up somewhere useful (e.g. in a GuC log) [Tvrtko Ursulin]. Signed-off-by: Dave Gordon Reviewed-by: Tvrtko Ursulin Signed-off-by: Tvrtko Ursulin --- drivers/gpu/drm/i915/i915_guc_submission.c | 71 +++++++++++----------- drivers/gpu/drm/i915/intel_guc.h | 2 +- drivers/gpu/drm/i915/intel_guc_fwif.h | 3 +- 3 files changed, 38 insertions(+), 38 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c index 85b2b89eeb3a..42a85088657b 100644 --- a/drivers/gpu/drm/i915/i915_guc_submission.c +++ b/drivers/gpu/drm/i915/i915_guc_submission.c @@ -486,23 +486,28 @@ int i915_guc_wq_check_space(struct drm_i915_gem_request *request) return -EAGAIN; } -static int guc_add_workqueue_item(struct i915_guc_client *gc, - struct drm_i915_gem_request *rq) +static void guc_add_workqueue_item(struct i915_guc_client *gc, + struct drm_i915_gem_request *rq) { + /* wqi_len is in DWords, and does not include the one-word header */ + const size_t wqi_size = sizeof(struct guc_wq_item); + const u32 wqi_len = wqi_size/sizeof(u32) - 1; struct guc_process_desc *desc; struct guc_wq_item *wqi; void *base; - u32 tail, wq_len, wq_off, space; + u32 freespace, tail, wq_off, wq_page; desc = gc->client_base + gc->proc_desc_offset; - space = CIRC_SPACE(gc->wq_tail, desc->head, gc->wq_size); - if (WARN_ON(space < sizeof(struct guc_wq_item))) - return -ENOSPC; /* shouldn't happen */ - /* 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; + /* Free space is guaranteed, see i915_guc_wq_check_space() above */ + freespace = CIRC_SPACE(gc->wq_tail, desc->head, gc->wq_size); + GEM_BUG_ON(freespace < wqi_size); + + /* The GuC firmware wants the tail index in QWords, not bytes */ + tail = rq->tail; + GEM_BUG_ON(tail & 7); + tail >>= 3; + GEM_BUG_ON(tail > WQ_RING_TAIL_MAX); /* 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 @@ -511,19 +516,23 @@ static int guc_add_workqueue_item(struct i915_guc_client *gc, * XXX: if not the case, we need save data to a temp wqi and copy it to * workqueue buffer dw by dw. */ - WARN_ON(sizeof(struct guc_wq_item) != 16); - WARN_ON(wq_off & 3); + BUILD_BUG_ON(wqi_size != 16); + + /* postincrement WQ tail for next time */ + wq_off = gc->wq_tail; + gc->wq_tail += wqi_size; + gc->wq_tail &= gc->wq_size - 1; + GEM_BUG_ON(wq_off & (wqi_size - 1)); - /* wq starts from the page after doorbell / process_desc */ - base = kmap_atomic(i915_gem_object_get_page(gc->client_obj, - (wq_off + GUC_DB_SIZE) >> PAGE_SHIFT)); + /* WQ starts from the page after doorbell / process_desc */ + wq_page = (wq_off + GUC_DB_SIZE) >> PAGE_SHIFT; wq_off &= PAGE_SIZE - 1; + base = kmap_atomic(i915_gem_object_get_page(gc->client_obj, wq_page)); wqi = (struct guc_wq_item *)((char *)base + wq_off); - /* len does not include the header */ - wq_len = sizeof(struct guc_wq_item) / sizeof(u32) - 1; + /* Now fill in the 4-word work queue item */ wqi->header = WQ_TYPE_INORDER | - (wq_len << WQ_LEN_SHIFT) | + (wqi_len << WQ_LEN_SHIFT) | (rq->engine->guc_id << WQ_TARGET_SHIFT) | WQ_NO_WCFLUSH_WAIT; @@ -531,14 +540,10 @@ static int guc_add_workqueue_item(struct i915_guc_client *gc, wqi->context_desc = (u32)intel_lr_context_descriptor(rq->ctx, rq->engine); - /* The GuC firmware wants the tail index in QWords, not bytes */ - tail = rq->ringbuf->tail >> 3; wqi->ring_tail = tail << WQ_RING_TAIL_SHIFT; - wqi->fence_id = 0; /*XXX: what fence to be here */ + wqi->fence_id = rq->seqno; kunmap_atomic(base); - - return 0; } /** @@ -565,26 +570,20 @@ int i915_guc_submit(struct drm_i915_gem_request *rq) unsigned int engine_id = rq->engine->guc_id; struct intel_guc *guc = &rq->i915->guc; struct i915_guc_client *client = guc->execbuf_client; - int q_ret, b_ret; + int b_ret; - q_ret = guc_add_workqueue_item(client, rq); - if (q_ret == 0) - b_ret = guc_ring_doorbell(client); + guc_add_workqueue_item(client, rq); + b_ret = guc_ring_doorbell(client); client->submissions[engine_id] += 1; - if (q_ret) { - client->q_fail += 1; - client->retcode = q_ret; - } else if (b_ret) { + client->retcode = b_ret; + if (b_ret) client->b_fail += 1; - client->retcode = q_ret = b_ret; - } else { - client->retcode = 0; - } + guc->submissions[engine_id] += 1; guc->last_seqno[engine_id] = rq->seqno; - return q_ret; + return b_ret; } /* diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h index 380a743f830f..7b1a5a3fb106 100644 --- a/drivers/gpu/drm/i915/intel_guc.h +++ b/drivers/gpu/drm/i915/intel_guc.h @@ -81,7 +81,7 @@ struct i915_guc_client { uint32_t unused; /* Was 'wq_head' */ uint32_t no_wq_space; - uint32_t q_fail; + uint32_t q_fail; /* No longer used */ uint32_t b_fail; int retcode; diff --git a/drivers/gpu/drm/i915/intel_guc_fwif.h b/drivers/gpu/drm/i915/intel_guc_fwif.h index 2de57ffe5e18..944786d7075b 100644 --- a/drivers/gpu/drm/i915/intel_guc_fwif.h +++ b/drivers/gpu/drm/i915/intel_guc_fwif.h @@ -71,7 +71,8 @@ #define WQ_WORKLOAD_TOUCH (2 << WQ_WORKLOAD_SHIFT) #define WQ_RING_TAIL_SHIFT 20 -#define WQ_RING_TAIL_MASK (0x7FF << WQ_RING_TAIL_SHIFT) +#define WQ_RING_TAIL_MAX 0x7FF /* 2^11 QWords */ +#define WQ_RING_TAIL_MASK (WQ_RING_TAIL_MAX << WQ_RING_TAIL_SHIFT) #define GUC_DOORBELL_ENABLED 1 #define GUC_DOORBELL_DISABLED 0 -- GitLab