Commit fb5970da authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915/gt: Use the kernel_context to measure the breadcrumb size 



We set up a dummy ring in order to measure the size we require for our
breadcrumb emission, so that we don't have to manually count dwords! We
can pass in the kernel_context to use for this so that if required it is
known for the breadcrumb emitter, and we can reuse some details from the
kernel_context to reduce the number of temporaries we have to mock.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: default avatarMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200207125827.2787472-1-chris@chris-wilson.co.uk
parent 71b7cc60

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

+19 −28
Original line number Diff line number Diff line
@@ -631,13 +631,13 @@ static int engine_setup_common(struct intel_engine_cs *engine) 


struct measure_breadcrumb {

	struct i915_request rq;

	struct intel_timeline timeline;

	struct intel_ring ring;

	u32 cs[1024];

};



static int measure_breadcrumb_dw(struct intel_engine_cs *engine)

static int measure_breadcrumb_dw(struct intel_context *ce)

{

	struct intel_engine_cs *engine = ce->engine;

	struct measure_breadcrumb *frame;

	int dw = -ENOMEM;
@@ -647,39 +647,27 @@ static int measure_breadcrumb_dw(struct intel_engine_cs *engine) 
	if (!frame)

		return -ENOMEM;



	if (intel_timeline_init(&frame->timeline,

				engine->gt,

				engine->status_page.vma))

		goto out_frame;



	mutex_lock(&frame->timeline.mutex);

	frame->rq.i915 = engine->i915;

	frame->rq.engine = engine;

	frame->rq.context = ce;

	rcu_assign_pointer(frame->rq.timeline, ce->timeline);



	frame->ring.vaddr = frame->cs;

	frame->ring.size = sizeof(frame->cs);

	frame->ring.effective_size = frame->ring.size;

	intel_ring_update_space(&frame->ring);



	frame->rq.i915 = engine->i915;

	frame->rq.engine = engine;

	frame->rq.ring = &frame->ring;

	rcu_assign_pointer(frame->rq.timeline, &frame->timeline);



	dw = intel_timeline_pin(&frame->timeline);

	if (dw < 0)

		goto out_timeline;



	mutex_lock(&ce->timeline->mutex);

	spin_lock_irq(&engine->active.lock);



	dw = engine->emit_fini_breadcrumb(&frame->rq, frame->cs) - frame->cs;



	spin_unlock_irq(&engine->active.lock);

	mutex_unlock(&ce->timeline->mutex);



	GEM_BUG_ON(dw & 1); /* RING_TAIL must be qword aligned */



	intel_timeline_unpin(&frame->timeline);



out_timeline:

	mutex_unlock(&frame->timeline.mutex);

	intel_timeline_fini(&frame->timeline);

out_frame:

	kfree(frame);

	return dw;

}
@@ -754,12 +742,6 @@ static int engine_init_common(struct intel_engine_cs *engine) 


	engine->set_default_submission(engine);



	ret = measure_breadcrumb_dw(engine);

	if (ret < 0)

		return ret;



	engine->emit_fini_breadcrumb_dw = ret;



	/*

	 * We may need to do things with the shrinker which

	 * require us to immediately switch back to the default
@@ -772,9 +754,18 @@ static int engine_init_common(struct intel_engine_cs *engine) 
	if (IS_ERR(ce))

		return PTR_ERR(ce);



	ret = measure_breadcrumb_dw(ce);

	if (ret < 0)

		goto err_context;



	engine->emit_fini_breadcrumb_dw = ret;

	engine->kernel_context = ce;



	return 0;



err_context:

	intel_context_put(ce);

	return ret;

}



int intel_engines_init(struct intel_gt *gt)

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