| Message ID | 20210624070516.21893-20-matthew.brost@intel.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | GuC submission support | expand |
On 6/24/2021 12:04 AM, Matthew Brost wrote: > 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. > > Signed-off-by: John Harrison <John.C.Harrison@Intel.com> > Signed-off-by: Matthew Brost <matthew.brost@intel.com> > --- > .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 1 - > drivers/gpu/drm/i915/i915_request.c | 17 +++++++++++++---- > 2 files changed, 13 insertions(+), 5 deletions(-) > > diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > index 0a6ccdf32316..010e46dd6b16 100644 > --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c > @@ -926,7 +926,6 @@ static void guc_context_sched_disable(struct intel_context *ce) > * request doesn't slip through the 'context_pending_disable' fence. > */ > if (unlikely(atomic_add_unless(&ce->pin_count, -2, 2))) { > - spin_unlock_irqrestore(&ce->guc_state.lock, flags); Why is this unlock() being dropped here? > return; > } > guc_id = prep_context_pending_disable(ce); > diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c > index 9dad3df5eaf7..d92c9f25c9f4 100644 > --- a/drivers/gpu/drm/i915/i915_request.c > +++ b/drivers/gpu/drm/i915/i915_request.c > @@ -444,6 +444,7 @@ 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)); This condition in the BUG_ON is not a new requirement introduced by the changes below, right? just want to make sure I'm not missing anything. > } while (i915_request_retire(tmp) && tmp != rq); > } > > @@ -1405,6 +1406,9 @@ i915_request_await_external(struct i915_request *rq, struct dma_fence *fence) > return err; > } > > +static int > +i915_request_await_request(struct i915_request *to, struct i915_request *from); > + > int > i915_request_await_execution(struct i915_request *rq, > struct dma_fence *fence, > @@ -1464,12 +1468,13 @@ await_request_submit(struct i915_request *to, struct i915_request *from) > * the waiter to be submitted immediately to the physical engine > * as it may then bypass the virtual request. > */ > - if (to->engine == READ_ONCE(from->engine)) > + if (to->engine == READ_ONCE(from->engine)) { > return i915_sw_fence_await_sw_fence_gfp(&to->submit, > &from->submit, > I915_FENCE_GFP); > - else > + } else { > return __i915_request_await_execution(to, from, NULL); > + } { } are not needed here. I'm guessing they're leftover from a dropped change. > } > > static int > @@ -1493,7 +1498,8 @@ 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); > @@ -1654,6 +1660,8 @@ __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 > @@ -1664,7 +1672,8 @@ __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)) Would it be worth adding an engine flag instead of checking which back-end is in use? I915_ENGINE_IS_FIFO or something. Not a blocker. Daniele > i915_sw_fence_await_sw_fence(&rq->submit, > &prev->submit, > &rq->submitq);
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c index 0a6ccdf32316..010e46dd6b16 100644 --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c @@ -926,7 +926,6 @@ static void guc_context_sched_disable(struct intel_context *ce) * request doesn't slip through the 'context_pending_disable' fence. */ if (unlikely(atomic_add_unless(&ce->pin_count, -2, 2))) { - spin_unlock_irqrestore(&ce->guc_state.lock, flags); return; } guc_id = prep_context_pending_disable(ce); diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c index 9dad3df5eaf7..d92c9f25c9f4 100644 --- a/drivers/gpu/drm/i915/i915_request.c +++ b/drivers/gpu/drm/i915/i915_request.c @@ -444,6 +444,7 @@ 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); } @@ -1405,6 +1406,9 @@ i915_request_await_external(struct i915_request *rq, struct dma_fence *fence) return err; } +static int +i915_request_await_request(struct i915_request *to, struct i915_request *from); + int i915_request_await_execution(struct i915_request *rq, struct dma_fence *fence, @@ -1464,12 +1468,13 @@ await_request_submit(struct i915_request *to, struct i915_request *from) * the waiter to be submitted immediately to the physical engine * as it may then bypass the virtual request. */ - if (to->engine == READ_ONCE(from->engine)) + if (to->engine == READ_ONCE(from->engine)) { return i915_sw_fence_await_sw_fence_gfp(&to->submit, &from->submit, I915_FENCE_GFP); - else + } else { return __i915_request_await_execution(to, from, NULL); + } } static int @@ -1493,7 +1498,8 @@ 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); @@ -1654,6 +1660,8 @@ __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 @@ -1664,7 +1672,8 @@ __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);