Commit 338aade9 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915/gt: Convert timeline tracking to spinlock 



Convert the active_list manipulation of timelines to use spinlocks so
that we can perform the updates from underneath a quick interrupt
callback, if need be.

Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190815205709.24285-2-chris@chris-wilson.co.uk
parent 531958f6

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

+1 −1
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ struct intel_gt { 
	struct intel_uc uc;



	struct intel_gt_timelines {

		struct mutex mutex; /* protects list */

		spinlock_t lock; /* protects active_list */

		struct list_head active_list;



		/* Pack multiple timelines' seqnos into the same page */

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

+8 −2
Original line number Diff line number Diff line
@@ -811,7 +811,7 @@ static bool __intel_gt_unset_wedged(struct intel_gt *gt) 
	 *

	 * No more can be submitted until we reset the wedged bit.

	 */

	mutex_lock(&timelines->mutex);

	spin_lock(&timelines->lock);

	list_for_each_entry(tl, &timelines->active_list, link) {

		struct i915_request *rq;
@@ -819,6 +819,8 @@ static bool __intel_gt_unset_wedged(struct intel_gt *gt) 
		if (!rq)

			continue;



		spin_unlock(&timelines->lock);



		/*

		 * All internal dependencies (i915_requests) will have

		 * been flushed by the set-wedge, but we may be stuck waiting
@@ -828,8 +830,12 @@ static bool __intel_gt_unset_wedged(struct intel_gt *gt) 
		 */

		dma_fence_default_wait(&rq->fence, false, MAX_SCHEDULE_TIMEOUT);

		i915_request_put(rq);



		/* Restart iteration after droping lock */

		spin_lock(&timelines->lock);

		tl = list_entry(&timelines->active_list, typeof(*tl), link);

	}

	mutex_unlock(&timelines->mutex);

	spin_unlock(&timelines->lock);



	intel_gt_sanitize(gt, false);

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

+5 −7
Original line number Diff line number Diff line
@@ -266,7 +266,7 @@ static void timelines_init(struct intel_gt *gt) 
{

	struct intel_gt_timelines *timelines = &gt->timelines;



	mutex_init(&timelines->mutex);

	spin_lock_init(&timelines->lock);

	INIT_LIST_HEAD(&timelines->active_list);



	spin_lock_init(&timelines->hwsp_lock);
@@ -345,9 +345,9 @@ void intel_timeline_enter(struct intel_timeline *tl) 
		return;

	GEM_BUG_ON(!tl->active_count); /* overflow? */



	mutex_lock(&timelines->mutex);

	spin_lock(&timelines->lock);

	list_add(&tl->link, &timelines->active_list);

	mutex_unlock(&timelines->mutex);

	spin_unlock(&timelines->lock);

}



void intel_timeline_exit(struct intel_timeline *tl)
@@ -358,9 +358,9 @@ void intel_timeline_exit(struct intel_timeline *tl) 
	if (--tl->active_count)

		return;



	mutex_lock(&timelines->mutex);

	spin_lock(&timelines->lock);

	list_del(&tl->link);

	mutex_unlock(&timelines->mutex);

	spin_unlock(&timelines->lock);



	/*

	 * Since this timeline is idle, all bariers upon which we were waiting
@@ -548,8 +548,6 @@ static void timelines_fini(struct intel_gt *gt) 


	GEM_BUG_ON(!list_empty(&timelines->active_list));

	GEM_BUG_ON(!list_empty(&timelines->hwsp_free_list));



	mutex_destroy(&timelines->mutex);

}



void intel_timelines_fini(struct drm_i915_private *i915)

drivers/gpu/drm/i915/i915_gem.c

+7 −7
Original line number Diff line number Diff line
@@ -897,18 +897,18 @@ static long 
wait_for_timelines(struct drm_i915_private *i915,

		   unsigned int flags, long timeout)

{

	struct intel_gt_timelines *gt = &i915->gt.timelines;

	struct intel_gt_timelines *timelines = &i915->gt.timelines;

	struct intel_timeline *tl;



	mutex_lock(&gt->mutex);

	list_for_each_entry(tl, &gt->active_list, link) {

	spin_lock(&timelines->lock);

	list_for_each_entry(tl, &timelines->active_list, link) {

		struct i915_request *rq;



		rq = i915_active_request_get_unlocked(&tl->last_request);

		if (!rq)

			continue;



		mutex_unlock(&gt->mutex);

		spin_unlock(&timelines->lock);



		/*

		 * "Race-to-idle".
@@ -928,10 +928,10 @@ wait_for_timelines(struct drm_i915_private *i915, 
			return timeout;



		/* restart after reacquiring the lock */

		mutex_lock(&gt->mutex);

		tl = list_entry(&gt->active_list, typeof(*tl), link);

		spin_lock(&timelines->lock);

		tl = list_entry(&timelines->active_list, typeof(*tl), link);

	}

	mutex_unlock(&gt->mutex);

	spin_unlock(&timelines->lock);



	return timeout;

}

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