From ab5eb50c2b0d34ba3e0530071dc481b198719e1b Mon Sep 17 00:00:00 2001 From: Matthew Brost Date: Wed, 21 Jul 2021 14:50:55 -0700 Subject: [PATCH] drm/i915/guc: Ensure request ordering via completion fences If two requests are on the same ring, they are explicitly ordered by the HW. So, a submission fence is sufficient to ensure ordering when using the new GuC submission interface. Conversely, if two requests share a timeline and are on the same physical engine but different context this doesn't ensure ordering on the new GuC submission interface. So, a completion fence needs to be used to ensure ordering. v2: (Daniele) - Don't delete spin lock v3: (Daniele) - Delete forward dec Signed-off-by: John Harrison Signed-off-by: Matthew Brost Reviewed-by: Daniele Ceraolo Spurio Signed-off-by: John Harrison Link: https://patchwork.freedesktop.org/patch/msgid/20210721215101.139794-13-matthew.brost@intel.com --- drivers/gpu/drm/i915/i915_request.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index d35d7c96839df..6594cb2f8ebdd 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -432,6 +432,7 @@ void i915_request_retire_upto(struct i915_request *rq) do { tmp = list_first_entry(&tl->requests, typeof(*tmp), link); + GEM_BUG_ON(!i915_request_completed(tmp)); } while (i915_request_retire(tmp) && tmp != rq); } @@ -1463,7 +1464,8 @@ i915_request_await_request(struct i915_request *to, struct i915_request *from) return ret; } - if (is_power_of_2(to->execution_mask | READ_ONCE(from->execution_mask))) + if (!intel_engine_uses_guc(to->engine) && + is_power_of_2(to->execution_mask | READ_ONCE(from->execution_mask))) ret = await_request_submit(to, from); else ret = emit_semaphore_wait(to, from, I915_FENCE_GFP); @@ -1622,6 +1624,8 @@ __i915_request_add_to_timeline(struct i915_request *rq) prev = to_request(__i915_active_fence_set(&timeline->last_request, &rq->fence)); if (prev && !__i915_request_is_complete(prev)) { + bool uses_guc = intel_engine_uses_guc(rq->engine); + /* * The requests are supposed to be kept in order. However, * we need to be wary in case the timeline->last_request @@ -1632,7 +1636,9 @@ __i915_request_add_to_timeline(struct i915_request *rq) i915_seqno_passed(prev->fence.seqno, rq->fence.seqno)); - if (is_power_of_2(READ_ONCE(prev->engine)->mask | rq->engine->mask)) + if ((!uses_guc && + is_power_of_2(READ_ONCE(prev->engine)->mask | rq->engine->mask)) || + (uses_guc && prev->context == rq->context)) i915_sw_fence_await_sw_fence(&rq->submit, &prev->submit, &rq->submitq); -- 2.39.5