Commit 7647f009 authored by Matthew Brost's avatar Matthew Brost Committed by John Harrison
Browse files

drm/i915: Update I915_GEM_BUSY IOCTL to understand composite fences 



Parallel submission create composite fences (dma_fence_array) for excl /
shared slots in objects. The I915_GEM_BUSY IOCTL checks these slots to
determine the busyness of the object. Prior to patch it only check if
the fence in the slot was a i915_request. Update the check to understand
composite fences and correctly report the busyness.

v2:
 (Tvrtko)
  - Remove duplicate BUILD_BUG_ON

Reviewed-by: default avatarDaniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: default avatarMatthew Brost <matthew.brost@intel.com>
Signed-off-by: default avatarJohn Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211014172005.27155-24-matthew.brost@intel.com
parent afc76f30

drivers/gpu/drm/i915/gem/i915_gem_busy.c

+45 −12
Original line number Diff line number Diff line
@@ -4,6 +4,8 @@ 
 * Copyright © 2014-2016 Intel Corporation

 */



#include <linux/dma-fence-array.h>



#include "gt/intel_engine.h"



#include "i915_gem_ioctls.h"
@@ -36,7 +38,7 @@ static __always_inline u32 __busy_write_id(u16 id) 
}



static __always_inline unsigned int

__busy_set_if_active(const struct dma_fence *fence, u32 (*flag)(u16 id))

__busy_set_if_active(struct dma_fence *fence, u32 (*flag)(u16 id))

{

	const struct i915_request *rq;
@@ -46,13 +48,43 @@ __busy_set_if_active(const struct dma_fence *fence, u32 (*flag)(u16 id)) 
	 * to eventually flush us, but to minimise latency just ask the

	 * hardware.

	 *

	 * Note we only report on the status of native fences.

	 * Note we only report on the status of native fences and we currently

	 * have two native fences:

	 *

	 * 1. A composite fence (dma_fence_array) constructed of i915 requests

	 * created during a parallel submission. In this case we deconstruct the

	 * composite fence into individual i915 requests and check the status of

	 * each request.

	 *

	 * 2. A single i915 request.

	 */

	if (dma_fence_is_array(fence)) {

		struct dma_fence_array *array = to_dma_fence_array(fence);

		struct dma_fence **child = array->fences;

		unsigned int nchild = array->num_fences;



		do {

			struct dma_fence *current_fence = *child++;



			/* Not an i915 fence, can't be busy per above */

			if (!dma_fence_is_i915(current_fence) ||

			    !test_bit(I915_FENCE_FLAG_COMPOSITE,

				      &current_fence->flags)) {

				return 0;

			}



			rq = to_request(current_fence);

			if (!i915_request_completed(rq))

				return flag(rq->engine->uabi_class);

		} while (--nchild);



		/* All requests in array complete, not busy */

		return 0;

	} else {

		if (!dma_fence_is_i915(fence))

			return 0;



	/* opencode to_request() in order to avoid const warnings */

	rq = container_of(fence, const struct i915_request, fence);

		rq = to_request(fence);

		if (i915_request_completed(rq))

			return 0;
@@ -60,15 +92,16 @@ __busy_set_if_active(const struct dma_fence *fence, u32 (*flag)(u16 id)) 
		BUILD_BUG_ON(!typecheck(u16, rq->engine->uabi_class));

		return flag(rq->engine->uabi_class);

	}

}



static __always_inline unsigned int

busy_check_reader(const struct dma_fence *fence)

busy_check_reader(struct dma_fence *fence)

{

	return __busy_set_if_active(fence, __busy_read_flag);

}



static __always_inline unsigned int

busy_check_writer(const struct dma_fence *fence)

busy_check_writer(struct dma_fence *fence)

{

	if (!fence)

		return 0;

drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c

+4 −1
Original line number Diff line number Diff line
@@ -2997,8 +2997,11 @@ eb_composite_fence_create(struct i915_execbuffer *eb, int out_fence_fd) 
	if (!fences)

		return ERR_PTR(-ENOMEM);



	for_each_batch_create_order(eb, i)

	for_each_batch_create_order(eb, i) {

		fences[i] = &eb->requests[i]->fence;

		__set_bit(I915_FENCE_FLAG_COMPOSITE,

			  &eb->requests[i]->fence.flags);

	}



	fence_array = dma_fence_array_create(eb->num_batches,

					     fences,

drivers/gpu/drm/i915/i915_request.h

+6 −0
Original line number Diff line number Diff line
@@ -156,6 +156,12 @@ enum { 
	 * submission / relationship encoutered an error.

	 */

	I915_FENCE_FLAG_SKIP_PARALLEL,



	/*

	 * I915_FENCE_FLAG_COMPOSITE - Indicates fence is part of a composite

	 * fence (dma_fence_array) and i915 generated for parallel submission.

	 */

	I915_FENCE_FLAG_COMPOSITE,

};



/**