Commit 0e97fbb0 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915/gem: Use a single chained reloc batches for a single execbuf 



As we can now keep chaining together a relocation batch to process any
number of relocations, we can keep building that relocation batch for
all of the target vma. This avoiding emitting a new request into the
ring for each target, consuming precious ring space and a potential
stall.

v2: Propagate the failure from submitting the relocation batch.

Testcase: igt/gem_exec_reloc/basic-wide-active
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: default avatarTvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200501192945.22215-2-chris@chris-wilson.co.uk
parent 964a9b0f

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

+24 −14
Original line number Diff line number Diff line
@@ -268,6 +268,7 @@ struct i915_execbuffer { 
		bool has_fence : 1;

		bool needs_unfenced : 1;



		struct i915_vma *target;

		struct i915_request *rq;

		struct i915_vma *rq_vma;

		u32 *rq_cmd;
@@ -1051,14 +1052,14 @@ static unsigned int reloc_bb_flags(const struct reloc_cache *cache) 
	return cache->gen > 5 ? 0 : I915_DISPATCH_SECURE;

}



static void reloc_gpu_flush(struct reloc_cache *cache)

static int reloc_gpu_flush(struct reloc_cache *cache)

{

	struct i915_request *rq;

	int err;



	rq = fetch_and_zero(&cache->rq);

	if (!rq)

		return;

		return 0;



	if (cache->rq_vma) {

		struct drm_i915_gem_object *obj = cache->rq_vma->obj;
@@ -1084,15 +1085,14 @@ static void reloc_gpu_flush(struct reloc_cache *cache) 


	intel_gt_chipset_flush(rq->engine->gt);

	i915_request_add(rq);



	return err;

}



static void reloc_cache_reset(struct reloc_cache *cache)

{

	void *vaddr;



	if (cache->rq)

		reloc_gpu_flush(cache);



	if (!cache->vaddr)

		return;
@@ -1285,7 +1285,6 @@ static int reloc_move_to_gpu(struct i915_request *rq, struct i915_vma *vma) 
}



static int __reloc_gpu_alloc(struct i915_execbuffer *eb,

			     struct i915_vma *vma,

			     unsigned int len)

{

	struct reloc_cache *cache = &eb->reloc_cache;
@@ -1308,7 +1307,7 @@ static int __reloc_gpu_alloc(struct i915_execbuffer *eb, 
		goto out_pool;

	}



	batch = i915_vma_instance(pool->obj, vma->vm, NULL);

	batch = i915_vma_instance(pool->obj, eb->context->vm, NULL);

	if (IS_ERR(batch)) {

		err = PTR_ERR(batch);

		goto err_unmap;
@@ -1328,10 +1327,6 @@ static int __reloc_gpu_alloc(struct i915_execbuffer *eb, 
	if (err)

		goto err_request;



	err = reloc_move_to_gpu(rq, vma);

	if (err)

		goto err_request;



	i915_vma_lock(batch);

	err = i915_request_await_object(rq, batch->obj, false);

	if (err == 0)
@@ -1376,11 +1371,21 @@ static u32 *reloc_gpu(struct i915_execbuffer *eb, 
		if (!intel_engine_can_store_dword(eb->engine))

			return ERR_PTR(-ENODEV);



		err = __reloc_gpu_alloc(eb, vma, len);

		err = __reloc_gpu_alloc(eb, len);

		if (unlikely(err))

			return ERR_PTR(err);

	}



	if (vma != cache->target) {

		err = reloc_move_to_gpu(cache->rq, vma);

		if (unlikely(err)) {

			i915_request_set_error_once(cache->rq, err);

			return ERR_PTR(err);

		}



		cache->target = vma;

	}



	if (unlikely(cache->rq_size + len >

		     PAGE_SIZE / sizeof(u32) - RELOC_TAIL)) {

		err = reloc_gpu_chain(cache);
@@ -1692,15 +1697,20 @@ static int eb_relocate(struct i915_execbuffer *eb) 
	/* The objects are in their final locations, apply the relocations. */

	if (eb->args->flags & __EXEC_HAS_RELOC) {

		struct eb_vma *ev;

		int flush;



		list_for_each_entry(ev, &eb->relocs, reloc_link) {

			err = eb_relocate_vma(eb, ev);

			if (err)

				return err;

				break;

		}



		flush = reloc_gpu_flush(&eb->reloc_cache);

		if (!err)

			err = flush;

	}



	return 0;

	return err;

}



static int eb_move_to_gpu(struct i915_execbuffer *eb)