Commit 09c5e3a5 authored by Matthew Brost's avatar Matthew Brost Committed by John Harrison
Browse files

drm/i915/guc: Assign contexts in parent-child relationship consecutive guc_ids 



Assign contexts in parent-child relationship consecutive guc_ids. This
is accomplished by partitioning guc_id space between ones that need to
be consecutive (1/16 available guc_ids) and ones that do not (15/16 of
available guc_ids). The consecutive search is implemented via the bitmap
API.

This is a precursor to the full GuC multi-lrc implementation but aligns
to how GuC mutli-lrc interface is defined - guc_ids must be consecutive
when using the GuC multi-lrc interface.

v2:
 (Daniel Vetter)
  - Explicitly state why we assign consecutive guc_ids
v3:
 (John Harrison)
  - Bring back in spin lock

Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Reviewed-by: default avatarJohn Harrison <John.C.Harrison@Intel.com>
Signed-off-by: default avatarJohn Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014172005.27155-11-matthew.brost@intel.com
parent 44d25fec

drivers/gpu/drm/i915/gt/uc/intel_guc.h

+5 −1
Original line number Original line Diff line number Diff line
@@ -82,9 +82,13 @@ struct intel_guc { 
		 */

		 */

		spinlock_t lock;

		spinlock_t lock;

		/**

		/**

		 * @guc_ids: used to allocate new guc_ids

		 * @guc_ids: used to allocate new guc_ids, single-lrc

		 */

		 */

		struct ida guc_ids;

		struct ida guc_ids;

		/**

		 * @guc_ids_bitmap: used to allocate new guc_ids, multi-lrc

		 */

		unsigned long *guc_ids_bitmap;

		/**

		/**

		 * @guc_id_list: list of intel_context with valid guc_ids but no

		 * @guc_id_list: list of intel_context with valid guc_ids but no

		 * refs

		 * refs

drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c

+81 −23
Original line number Original line Diff line number Diff line
@@ -128,6 +128,16 @@ guc_create_virtual(struct intel_engine_cs **siblings, unsigned int count); 




#define GUC_REQUEST_SIZE 64 /* bytes */

#define GUC_REQUEST_SIZE 64 /* bytes */





/*

 * We reserve 1/16 of the guc_ids for multi-lrc as these need to be contiguous

 * per the GuC submission interface. A different allocation algorithm is used

 * (bitmap vs. ida) between multi-lrc and single-lrc hence the reason to

 * partition the guc_id space. We believe the number of multi-lrc contexts in

 * use should be low and 1/16 should be sufficient. Minimum of 32 guc_ids for

 * multi-lrc.

 */

#define NUMBER_MULTI_LRC_GUC_ID		(GUC_MAX_LRC_DESCRIPTORS / 16)



/*

/*

 * Below is a set of functions which control the GuC scheduling state which

 * Below is a set of functions which control the GuC scheduling state which

 * require a lock.

 * require a lock.
@@ -1207,6 +1217,11 @@ int intel_guc_submission_init(struct intel_guc *guc) 
	INIT_WORK(&guc->submission_state.destroyed_worker,

	INIT_WORK(&guc->submission_state.destroyed_worker,

		  destroyed_worker_func);

		  destroyed_worker_func);





	guc->submission_state.guc_ids_bitmap =

		bitmap_zalloc(NUMBER_MULTI_LRC_GUC_ID, GFP_KERNEL);

	if (!guc->submission_state.guc_ids_bitmap)

		return -ENOMEM;



	return 0;

	return 0;

}

}
@@ -1218,6 +1233,7 @@ void intel_guc_submission_fini(struct intel_guc *guc) 
	guc_flush_destroyed_contexts(guc);

	guc_flush_destroyed_contexts(guc);

	guc_lrc_desc_pool_destroy(guc);

	guc_lrc_desc_pool_destroy(guc);

	i915_sched_engine_put(guc->sched_engine);

	i915_sched_engine_put(guc->sched_engine);

	bitmap_free(guc->submission_state.guc_ids_bitmap);

}

}





static inline void queue_request(struct i915_sched_engine *sched_engine,

static inline void queue_request(struct i915_sched_engine *sched_engine,
@@ -1269,16 +1285,41 @@ static void guc_submit_request(struct i915_request *rq) 
	spin_unlock_irqrestore(&sched_engine->lock, flags);

	spin_unlock_irqrestore(&sched_engine->lock, flags);

}

}





static int new_guc_id(struct intel_guc *guc)

static int new_guc_id(struct intel_guc *guc, struct intel_context *ce)

{

{

	return ida_simple_get(&guc->submission_state.guc_ids, 0,

	int ret;

			      GUC_MAX_LRC_DESCRIPTORS, GFP_KERNEL |



			      __GFP_RETRY_MAYFAIL | __GFP_NOWARN);

	GEM_BUG_ON(intel_context_is_child(ce));



	if (intel_context_is_parent(ce))

		ret = bitmap_find_free_region(guc->submission_state.guc_ids_bitmap,

					      NUMBER_MULTI_LRC_GUC_ID,

					      order_base_2(ce->parallel.number_children

							   + 1));

	else

		ret = ida_simple_get(&guc->submission_state.guc_ids,

				     NUMBER_MULTI_LRC_GUC_ID,

				     GUC_MAX_LRC_DESCRIPTORS,

				     GFP_KERNEL | __GFP_RETRY_MAYFAIL |

				     __GFP_NOWARN);

	if (unlikely(ret < 0))

		return ret;



	ce->guc_id.id = ret;

	return 0;

}

}





static void __release_guc_id(struct intel_guc *guc, struct intel_context *ce)

static void __release_guc_id(struct intel_guc *guc, struct intel_context *ce)

{

{

	GEM_BUG_ON(intel_context_is_child(ce));



	if (!context_guc_id_invalid(ce)) {

	if (!context_guc_id_invalid(ce)) {

		if (intel_context_is_parent(ce))

			bitmap_release_region(guc->submission_state.guc_ids_bitmap,

					      ce->guc_id.id,

					      order_base_2(ce->parallel.number_children

							   + 1));

		else

			ida_simple_remove(&guc->submission_state.guc_ids,

			ida_simple_remove(&guc->submission_state.guc_ids,

					  ce->guc_id.id);

					  ce->guc_id.id);

		reset_lrc_desc(guc, ce->guc_id.id);

		reset_lrc_desc(guc, ce->guc_id.id);
@@ -1297,49 +1338,64 @@ static void release_guc_id(struct intel_guc *guc, struct intel_context *ce) 
	spin_unlock_irqrestore(&guc->submission_state.lock, flags);

	spin_unlock_irqrestore(&guc->submission_state.lock, flags);

}

}





static int steal_guc_id(struct intel_guc *guc)

static int steal_guc_id(struct intel_guc *guc, struct intel_context *ce)

{

{

	struct intel_context *ce;

	struct intel_context *cn;

	int guc_id;





	lockdep_assert_held(&guc->submission_state.lock);

	lockdep_assert_held(&guc->submission_state.lock);

	GEM_BUG_ON(intel_context_is_child(ce));

	GEM_BUG_ON(intel_context_is_parent(ce));





	if (!list_empty(&guc->submission_state.guc_id_list)) {

	if (!list_empty(&guc->submission_state.guc_id_list)) {

		ce = list_first_entry(&guc->submission_state.guc_id_list,

		cn = list_first_entry(&guc->submission_state.guc_id_list,

				      struct intel_context,

				      struct intel_context,

				      guc_id.link);

				      guc_id.link);





		GEM_BUG_ON(atomic_read(&ce->guc_id.ref));

		GEM_BUG_ON(atomic_read(&cn->guc_id.ref));

		GEM_BUG_ON(context_guc_id_invalid(ce));

		GEM_BUG_ON(context_guc_id_invalid(cn));

		GEM_BUG_ON(intel_context_is_child(cn));

		GEM_BUG_ON(intel_context_is_parent(cn));





		list_del_init(&ce->guc_id.link);

		list_del_init(&cn->guc_id.link);

		guc_id = ce->guc_id.id;

		ce->guc_id = cn->guc_id;





		spin_lock(&ce->guc_state.lock);

		spin_lock(&ce->guc_state.lock);

		clr_context_registered(ce);

		clr_context_registered(cn);

		spin_unlock(&ce->guc_state.lock);

		spin_unlock(&ce->guc_state.lock);





		set_context_guc_id_invalid(ce);

		set_context_guc_id_invalid(cn);

		return guc_id;



		return 0;

	} else {

	} else {

		return -EAGAIN;

		return -EAGAIN;

	}

	}

}

}





static int assign_guc_id(struct intel_guc *guc, u16 *out)

static int assign_guc_id(struct intel_guc *guc, struct intel_context *ce)

{

{

	int ret;

	int ret;





	lockdep_assert_held(&guc->submission_state.lock);

	lockdep_assert_held(&guc->submission_state.lock);

	GEM_BUG_ON(intel_context_is_child(ce));





	ret = new_guc_id(guc);

	ret = new_guc_id(guc, ce);

	if (unlikely(ret < 0)) {

	if (unlikely(ret < 0)) {

		ret = steal_guc_id(guc);

		if (intel_context_is_parent(ce))

			return -ENOSPC;



		ret = steal_guc_id(guc, ce);

		if (ret < 0)

		if (ret < 0)

			return ret;

			return ret;

	}

	}





	*out = ret;

	if (intel_context_is_parent(ce)) {

		struct intel_context *child;

		int i = 1;



		for_each_child(ce, child)

			child->guc_id.id = ce->guc_id.id + i++;

	}



	return 0;

	return 0;

}

}
@@ -1357,7 +1413,7 @@ static int pin_guc_id(struct intel_guc *guc, struct intel_context *ce) 
	might_lock(&ce->guc_state.lock);

	might_lock(&ce->guc_state.lock);





	if (context_guc_id_invalid(ce)) {

	if (context_guc_id_invalid(ce)) {

		ret = assign_guc_id(guc, &ce->guc_id.id);

		ret = assign_guc_id(guc, ce);

		if (ret)

		if (ret)

			goto out_unlock;

			goto out_unlock;

		ret = 1;	/* Indidcates newly assigned guc_id */

		ret = 1;	/* Indidcates newly assigned guc_id */
@@ -1399,8 +1455,10 @@ static void unpin_guc_id(struct intel_guc *guc, struct intel_context *ce) 
	unsigned long flags;

	unsigned long flags;





	GEM_BUG_ON(atomic_read(&ce->guc_id.ref) < 0);

	GEM_BUG_ON(atomic_read(&ce->guc_id.ref) < 0);

	GEM_BUG_ON(intel_context_is_child(ce));





	if (unlikely(context_guc_id_invalid(ce)))

	if (unlikely(context_guc_id_invalid(ce) ||

		     intel_context_is_parent(ce)))

		return;

		return;





	spin_lock_irqsave(&guc->submission_state.lock, flags);

	spin_lock_irqsave(&guc->submission_state.lock, flags);