Commit 54400257 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915/gt: Remove direct invocation of breadcrumb signaling 



Only signal the breadcrumbs from inside the irq_work, simplifying our
interface and calling conventions. The micro-optimisation here is that
by always using the irq_work interface, we know we are always inside an
irq-off critical section for the breadcrumb signaling and can ellide
save/restore of the irq flags.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191217095642.3124521-7-chris@chris-wilson.co.uk
parent df6a4205

drivers/gpu/drm/i915/gt/intel_breadcrumbs.c

+9 −18
Original line number Diff line number Diff line
@@ -130,16 +130,15 @@ __dma_fence_signal__notify(struct dma_fence *fence, 
	}

}



void intel_engine_breadcrumbs_irq(struct intel_engine_cs *engine)

static void signal_irq_work(struct irq_work *work)

{

	struct intel_breadcrumbs *b = &engine->breadcrumbs;

	struct intel_breadcrumbs *b = container_of(work, typeof(*b), irq_work);

	const ktime_t timestamp = ktime_get();

	struct intel_context *ce, *cn;

	struct list_head *pos, *next;

	unsigned long flags;

	LIST_HEAD(signal);



	spin_lock_irqsave(&b->irq_lock, flags);

	spin_lock(&b->irq_lock);



	if (b->irq_armed && list_empty(&b->signalers))

		__intel_breadcrumbs_disarm_irq(b);
@@ -185,31 +184,23 @@ void intel_engine_breadcrumbs_irq(struct intel_engine_cs *engine) 
		}

	}



	spin_unlock_irqrestore(&b->irq_lock, flags);

	spin_unlock(&b->irq_lock);



	list_for_each_safe(pos, next, &signal) {

		struct i915_request *rq =

			list_entry(pos, typeof(*rq), signal_link);

		struct list_head cb_list;



		spin_lock_irqsave(&rq->lock, flags);

		spin_lock(&rq->lock);

		list_replace(&rq->fence.cb_list, &cb_list);

		__dma_fence_signal__timestamp(&rq->fence, timestamp);

		__dma_fence_signal__notify(&rq->fence, &cb_list);

		spin_unlock_irqrestore(&rq->lock, flags);

		spin_unlock(&rq->lock);



		i915_request_put(rq);

	}

}



static void signal_irq_work(struct irq_work *work)

{

	struct intel_engine_cs *engine =

		container_of(work, typeof(*engine), breadcrumbs.irq_work);



	intel_engine_breadcrumbs_irq(engine);

}



static bool __intel_breadcrumbs_arm_irq(struct intel_breadcrumbs *b)

{

	struct intel_engine_cs *engine =
@@ -290,9 +281,9 @@ bool i915_request_enable_breadcrumb(struct i915_request *rq) 


		/*

		 * We keep the seqno in retirement order, so we can break

		 * inside intel_engine_breadcrumbs_irq as soon as we've passed

		 * the last completed request (or seen a request that hasn't

		 * event started). We could iterate the timeline->requests list,

		 * inside intel_engine_signal_breadcrumbs as soon as we've

		 * passed the last completed request (or seen a request that

		 * hasn't event started). We could walk the timeline->requests,

		 * but keeping a separate signalers_list has the advantage of

		 * hopefully being much smaller than the full list and so

		 * provides faster iteration and detection when there are no

drivers/gpu/drm/i915/gt/intel_engine.h

+1 −3
Original line number Diff line number Diff line
@@ -213,13 +213,11 @@ void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine); 
void intel_engine_disarm_breadcrumbs(struct intel_engine_cs *engine);



static inline void

intel_engine_queue_breadcrumbs(struct intel_engine_cs *engine)

intel_engine_signal_breadcrumbs(struct intel_engine_cs *engine)

{

	irq_work_queue(&engine->breadcrumbs.irq_work);

}



void intel_engine_breadcrumbs_irq(struct intel_engine_cs *engine);



void intel_engine_reset_breadcrumbs(struct intel_engine_cs *engine);

void intel_engine_fini_breadcrumbs(struct intel_engine_cs *engine);

drivers/gpu/drm/i915/gt/intel_gt_irq.c

+6 −6
Original line number Diff line number Diff line
@@ -28,7 +28,7 @@ cs_irq_handler(struct intel_engine_cs *engine, u32 iir) 
		tasklet = true;



	if (iir & GT_RENDER_USER_INTERRUPT) {

		intel_engine_queue_breadcrumbs(engine);

		intel_engine_signal_breadcrumbs(engine);

		tasklet |= intel_engine_needs_breadcrumb_tasklet(engine);

	}
@@ -245,9 +245,9 @@ void gen11_gt_irq_postinstall(struct intel_gt *gt) 
void gen5_gt_irq_handler(struct intel_gt *gt, u32 gt_iir)

{

	if (gt_iir & GT_RENDER_USER_INTERRUPT)

		intel_engine_breadcrumbs_irq(gt->engine_class[RENDER_CLASS][0]);

		intel_engine_signal_breadcrumbs(gt->engine_class[RENDER_CLASS][0]);

	if (gt_iir & ILK_BSD_USER_INTERRUPT)

		intel_engine_breadcrumbs_irq(gt->engine_class[VIDEO_DECODE_CLASS][0]);

		intel_engine_signal_breadcrumbs(gt->engine_class[VIDEO_DECODE_CLASS][0]);

}



static void gen7_parity_error_irq_handler(struct intel_gt *gt, u32 iir)
@@ -271,11 +271,11 @@ static void gen7_parity_error_irq_handler(struct intel_gt *gt, u32 iir) 
void gen6_gt_irq_handler(struct intel_gt *gt, u32 gt_iir)

{

	if (gt_iir & GT_RENDER_USER_INTERRUPT)

		intel_engine_breadcrumbs_irq(gt->engine_class[RENDER_CLASS][0]);

		intel_engine_signal_breadcrumbs(gt->engine_class[RENDER_CLASS][0]);

	if (gt_iir & GT_BSD_USER_INTERRUPT)

		intel_engine_breadcrumbs_irq(gt->engine_class[VIDEO_DECODE_CLASS][0]);

		intel_engine_signal_breadcrumbs(gt->engine_class[VIDEO_DECODE_CLASS][0]);

	if (gt_iir & GT_BLT_USER_INTERRUPT)

		intel_engine_breadcrumbs_irq(gt->engine_class[COPY_ENGINE_CLASS][0]);

		intel_engine_signal_breadcrumbs(gt->engine_class[COPY_ENGINE_CLASS][0]);



	if (gt_iir & (GT_BLT_CS_ERROR_INTERRUPT |

		      GT_BSD_CS_ERROR_INTERRUPT |

drivers/gpu/drm/i915/gt/intel_lrc.c

+1 −1
Original line number Diff line number Diff line
@@ -1483,7 +1483,7 @@ static void virtual_xfer_breadcrumbs(struct virtual_engine *ve, 
	if (!list_empty(&ve->context.signal_link)) {

		list_move_tail(&ve->context.signal_link,

			       &engine->breadcrumbs.signalers);

		intel_engine_queue_breadcrumbs(engine);

		intel_engine_signal_breadcrumbs(engine);

	}

	spin_unlock(&old->breadcrumbs.irq_lock);

}

drivers/gpu/drm/i915/gt/intel_reset.c

+2 −2
Original line number Diff line number Diff line
@@ -742,7 +742,7 @@ static void reset_finish_engine(struct intel_engine_cs *engine) 
	engine->reset.finish(engine);

	intel_uncore_forcewake_put(engine->uncore, FORCEWAKE_ALL);



	intel_engine_breadcrumbs_irq(engine);

	intel_engine_signal_breadcrumbs(engine);

}



static void reset_finish(struct intel_gt *gt, intel_engine_mask_t awake)
@@ -771,7 +771,7 @@ static void nop_submit_request(struct i915_request *request) 
	i915_request_mark_complete(request);

	spin_unlock_irqrestore(&engine->active.lock, flags);



	intel_engine_queue_breadcrumbs(engine);

	intel_engine_signal_breadcrumbs(engine);

}



static void __intel_gt_set_wedged(struct intel_gt *gt)

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