Commit 1e345568 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Move list of timelines under its own lock 



Currently, the list of timelines is serialised by the struct_mutex, but
to alleviate difficulties with using that mutex in future, move the
list management under its own dedicated mutex.

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/20190128102356.15037-5-chris@chris-wilson.co.uk
parent 0ca88ba0

drivers/gpu/drm/i915/i915_drv.h

+4 −1
Original line number Diff line number Diff line
@@ -1975,7 +1975,10 @@ struct drm_i915_private { 
		void (*resume)(struct drm_i915_private *);

		void (*cleanup_engine)(struct intel_engine_cs *engine);



		struct list_head timelines;

		struct i915_gt_timelines {

			struct mutex mutex; /* protects list, tainted by GPU */

			struct list_head list;

		} timelines;



		struct list_head active_rings;

		struct list_head closed_vma;

drivers/gpu/drm/i915/i915_gem.c

+56 −47
Original line number Diff line number Diff line
@@ -3222,14 +3222,38 @@ i915_gem_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *file) 
	return ret;

}



static long wait_for_timeline(struct i915_timeline *tl,

static int wait_for_engines(struct drm_i915_private *i915)

{

	if (wait_for(intel_engines_are_idle(i915), I915_IDLE_ENGINES_TIMEOUT)) {

		dev_err(i915->drm.dev,

			"Failed to idle engines, declaring wedged!\n");

		GEM_TRACE_DUMP();

		i915_gem_set_wedged(i915);

		return -EIO;

	}



	return 0;

}



static long

wait_for_timelines(struct drm_i915_private *i915,

		   unsigned int flags, long timeout)

{

	struct i915_gt_timelines *gt = &i915->gt.timelines;

	struct i915_timeline *tl;



	if (!READ_ONCE(i915->gt.active_requests))

		return timeout;



	mutex_lock(&gt->mutex);

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

		struct i915_request *rq;



		rq = i915_gem_active_get_unlocked(&tl->last_request);

		if (!rq)

		return timeout;

			continue;



		mutex_unlock(&gt->mutex);



		/*

		 * "Race-to-idle".
@@ -3245,21 +3269,16 @@ static long wait_for_timeline(struct i915_timeline *tl, 


		timeout = i915_request_wait(rq, flags, timeout);

		i915_request_put(rq);



		if (timeout < 0)

			return timeout;

}



static int wait_for_engines(struct drm_i915_private *i915)

{

	if (wait_for(intel_engines_are_idle(i915), I915_IDLE_ENGINES_TIMEOUT)) {

		dev_err(i915->drm.dev,

			"Failed to idle engines, declaring wedged!\n");

		GEM_TRACE_DUMP();

		i915_gem_set_wedged(i915);

		return -EIO;

		/* restart after reacquiring the lock */

		mutex_lock(&gt->mutex);

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

	}

	mutex_unlock(&gt->mutex);



	return 0;

	return timeout;

}



int i915_gem_wait_for_idle(struct drm_i915_private *i915,
@@ -3273,17 +3292,15 @@ int i915_gem_wait_for_idle(struct drm_i915_private *i915, 
	if (!READ_ONCE(i915->gt.awake))

		return 0;



	timeout = wait_for_timelines(i915, flags, timeout);

	if (timeout < 0)

		return timeout;



	if (flags & I915_WAIT_LOCKED) {

		struct i915_timeline *tl;

		int err;



		lockdep_assert_held(&i915->drm.struct_mutex);



		list_for_each_entry(tl, &i915->gt.timelines, link) {

			timeout = wait_for_timeline(tl, flags, timeout);

			if (timeout < 0)

				return timeout;

		}

		if (GEM_SHOW_DEBUG() && !timeout) {

			/* Presume that timeout was non-zero to begin with! */

			dev_warn(&i915->drm.pdev->dev,
@@ -3297,17 +3314,6 @@ int i915_gem_wait_for_idle(struct drm_i915_private *i915, 


		i915_retire_requests(i915);

		GEM_BUG_ON(i915->gt.active_requests);

	} else {

		struct intel_engine_cs *engine;

		enum intel_engine_id id;



		for_each_engine(engine, i915, id) {

			struct i915_timeline *tl = &engine->timeline;



			timeout = wait_for_timeline(tl, flags, timeout);

			if (timeout < 0)

				return timeout;

		}

	}



	return 0;
@@ -5008,6 +5014,8 @@ int i915_gem_init(struct drm_i915_private *dev_priv) 
		dev_priv->gt.cleanup_engine = intel_engine_cleanup;

	}



	i915_timelines_init(dev_priv);



	ret = i915_gem_init_userptr(dev_priv);

	if (ret)

		return ret;
@@ -5130,8 +5138,10 @@ err_unlock: 
err_uc_misc:

	intel_uc_fini_misc(dev_priv);



	if (ret != -EIO)

	if (ret != -EIO) {

		i915_gem_cleanup_userptr(dev_priv);

		i915_timelines_fini(dev_priv);

	}



	if (ret == -EIO) {

		mutex_lock(&dev_priv->drm.struct_mutex);
@@ -5182,6 +5192,7 @@ void i915_gem_fini(struct drm_i915_private *dev_priv) 


	intel_uc_fini_misc(dev_priv);

	i915_gem_cleanup_userptr(dev_priv);

	i915_timelines_fini(dev_priv);



	i915_gem_drain_freed_objects(dev_priv);
@@ -5284,7 +5295,6 @@ int i915_gem_init_early(struct drm_i915_private *dev_priv) 
	if (!dev_priv->priorities)

		goto err_dependencies;



	INIT_LIST_HEAD(&dev_priv->gt.timelines);

	INIT_LIST_HEAD(&dev_priv->gt.active_rings);

	INIT_LIST_HEAD(&dev_priv->gt.closed_vma);
@@ -5328,7 +5338,6 @@ void i915_gem_cleanup_early(struct drm_i915_private *dev_priv) 
	GEM_BUG_ON(!llist_empty(&dev_priv->mm.free_list));

	GEM_BUG_ON(atomic_read(&dev_priv->mm.free_count));

	WARN_ON(dev_priv->mm.object_count);

	WARN_ON(!list_empty(&dev_priv->gt.timelines));



	kmem_cache_destroy(dev_priv->priorities);

	kmem_cache_destroy(dev_priv->dependencies);

drivers/gpu/drm/i915/i915_reset.c

+6 −2
Original line number Diff line number Diff line
@@ -854,7 +854,8 @@ bool i915_gem_unset_wedged(struct drm_i915_private *i915) 
	 *

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

	 */

	list_for_each_entry(tl, &i915->gt.timelines, link) {

	mutex_lock(&i915->gt.timelines.mutex);

	list_for_each_entry(tl, &i915->gt.timelines.list, link) {

		struct i915_request *rq;

		long timeout;
@@ -876,9 +877,12 @@ bool i915_gem_unset_wedged(struct drm_i915_private *i915) 
		timeout = dma_fence_default_wait(&rq->fence, true,

						 MAX_SCHEDULE_TIMEOUT);

		i915_request_put(rq);

		if (timeout < 0)

		if (timeout < 0) {

			mutex_unlock(&i915->gt.timelines.mutex);

			goto unlock;

		}

	}

	mutex_unlock(&i915->gt.timelines.mutex);



	intel_engines_sanitize(i915, false);

drivers/gpu/drm/i915/i915_timeline.c

+33 −5
Original line number Diff line number Diff line
@@ -13,7 +13,7 @@ void i915_timeline_init(struct drm_i915_private *i915, 
			struct i915_timeline *timeline,

			const char *name)

{

	lockdep_assert_held(&i915->drm.struct_mutex);

	struct i915_gt_timelines *gt = &i915->gt.timelines;



	/*

	 * Ideally we want a set of engines on a single leaf as we expect
@@ -23,9 +23,12 @@ void i915_timeline_init(struct drm_i915_private *i915, 
	 */

	BUILD_BUG_ON(KSYNCMAP < I915_NUM_ENGINES);



	timeline->i915 = i915;

	timeline->name = name;



	list_add(&timeline->link, &i915->gt.timelines);

	mutex_lock(&gt->mutex);

	list_add(&timeline->link, &gt->list);

	mutex_unlock(&gt->mutex);



	/* Called during early_init before we know how many engines there are */
@@ -39,6 +42,17 @@ void i915_timeline_init(struct drm_i915_private *i915, 
	i915_syncmap_init(&timeline->sync);

}



void i915_timelines_init(struct drm_i915_private *i915)

{

	struct i915_gt_timelines *gt = &i915->gt.timelines;



	mutex_init(&gt->mutex);

	INIT_LIST_HEAD(&gt->list);



	/* via i915_gem_wait_for_idle() */

	i915_gem_shrinker_taints_mutex(i915, &gt->mutex);

}



/**

 * i915_timelines_park - called when the driver idles

 * @i915: the drm_i915_private device
@@ -51,11 +65,11 @@ void i915_timeline_init(struct drm_i915_private *i915, 
 */

void i915_timelines_park(struct drm_i915_private *i915)

{

	struct i915_gt_timelines *gt = &i915->gt.timelines;

	struct i915_timeline *timeline;



	lockdep_assert_held(&i915->drm.struct_mutex);



	list_for_each_entry(timeline, &i915->gt.timelines, link) {

	mutex_lock(&gt->mutex);

	list_for_each_entry(timeline, &gt->list, link) {

		/*

		 * All known fences are completed so we can scrap

		 * the current sync point tracking and start afresh,
@@ -64,15 +78,20 @@ void i915_timelines_park(struct drm_i915_private *i915) 
		 */

		i915_syncmap_free(&timeline->sync);

	}

	mutex_unlock(&gt->mutex);

}



void i915_timeline_fini(struct i915_timeline *timeline)

{

	struct i915_gt_timelines *gt = &timeline->i915->gt.timelines;



	GEM_BUG_ON(!list_empty(&timeline->requests));



	i915_syncmap_free(&timeline->sync);



	mutex_lock(&gt->mutex);

	list_del(&timeline->link);

	mutex_unlock(&gt->mutex);

}



struct i915_timeline *
@@ -99,6 +118,15 @@ void __i915_timeline_free(struct kref *kref) 
	kfree(timeline);

}



void i915_timelines_fini(struct drm_i915_private *i915)

{

	struct i915_gt_timelines *gt = &i915->gt.timelines;



	GEM_BUG_ON(!list_empty(&gt->list));



	mutex_destroy(&gt->mutex);

}



#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)

#include "selftests/mock_timeline.c"

#include "selftests/i915_timeline.c"

drivers/gpu/drm/i915/i915_timeline.h

+3 −0
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ struct i915_timeline { 


	struct list_head link;

	const char *name;

	struct drm_i915_private *i915;



	struct kref kref;

};
@@ -134,6 +135,8 @@ static inline bool i915_timeline_sync_is_later(struct i915_timeline *tl, 
	return __i915_timeline_sync_is_later(tl, fence->context, fence->seqno);

}



void i915_timelines_init(struct drm_i915_private *i915);

void i915_timelines_park(struct drm_i915_private *i915);

void i915_timelines_fini(struct drm_i915_private *i915);



#endif

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