Commit fb218f20 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915/gt: Discard stale context state from across idling 



Before we idle, on parking, we switch to the kernel context such that we
have a scratch context loaded while the GPU idle, protecting any
precious user state. Be paranoid and assume that the idle state may have
been trashed, and reset the kernel_context image after idling.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
Reviewed-by: default avatarMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200102131707.1463945-4-chris@chris-wilson.co.uk
parent 49a24e71

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

+6 −0
Original line number Diff line number Diff line
@@ -20,6 +20,7 @@ static int __engine_unpark(struct intel_wakeref *wf) 
{

	struct intel_engine_cs *engine =

		container_of(wf, typeof(*engine), wakeref);

	struct intel_context *ce;

	void *map;



	ENGINE_TRACE(engine, "\n");
@@ -34,6 +35,11 @@ static int __engine_unpark(struct intel_wakeref *wf) 
	if (!IS_ERR_OR_NULL(map))

		engine->pinned_default_state = map;



	/* Discard stale context state from across idling */

	ce = engine->kernel_context;

	if (ce)

		ce->ops->reset(ce);



	if (engine->unpark)

		engine->unpark(engine);

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

+0 −8
Original line number Diff line number Diff line
@@ -213,16 +213,8 @@ int intel_gt_resume(struct intel_gt *gt) 
	intel_llc_enable(&gt->llc);



	for_each_engine(engine, gt, id) {

		struct intel_context *ce;



		intel_engine_pm_get(engine);



		ce = engine->kernel_context;

		if (ce) {

			GEM_BUG_ON(!intel_context_is_pinned(ce));

			ce->ops->reset(ce);

		}



		engine->serial++; /* kernel context lost */

		err = engine->resume(engine);

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

+5 −0
Original line number Diff line number Diff line
@@ -152,6 +152,10 @@ static int mock_context_pin(struct intel_context *ce) 
	return intel_context_active_acquire(ce);

}



static void mock_context_reset(struct intel_context *ce)

{

}



static const struct intel_context_ops mock_context_ops = {

	.alloc = mock_context_alloc,
@@ -161,6 +165,7 @@ static const struct intel_context_ops mock_context_ops = { 
	.enter = intel_context_enter_engine,

	.exit = intel_context_exit_engine,



	.reset = mock_context_reset,

	.destroy = mock_context_destroy,

};

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