[PATCH v1 17/20] drm/amdgpu: get rid of amdgpu_ttm_clear_buffer

[Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>]

It's doing the same thing as amdgpu_fill_buffer(src_data=0), so drop it.

The only caveat is that amdgpu_res_cleared() return value is only valid
right after allocation.

Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c |  9 +--
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c    | 86 ++++------------------
 drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h    |  3 -
 3 files changed, 18 insertions(+), 80 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 4a69324bb730..410e9b68ff81 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -723,15 +723,10 @@ int amdgpu_bo_create(struct amdgpu_device *adev,
 
 	if (bp->flags & AMDGPU_GEM_CREATE_VRAM_CLEARED &&
 	    bo->tbo.resource->mem_type == TTM_PL_VRAM) {
-		struct dma_fence *fence;
-
-		r = amdgpu_ttm_clear_buffer(bo, bo->tbo.base.resv, &fence);
+		r = amdgpu_fill_buffer(NULL, bo, 0, NULL,
+				       NULL, AMDGPU_KERNEL_JOB_ID_TTM_CLEAR_BUFFER);
 		if (unlikely(r))
 			goto fail_unreserve;
-
-		dma_resv_add_fence(bo->tbo.base.resv, fence,
-				   DMA_RESV_USAGE_KERNEL);
-		dma_fence_put(fence);
 	}
 	if (!bp->resv)
 		amdgpu_bo_unreserve(bo);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index d88bdb2ac083..1f553c56f31d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -2412,75 +2412,6 @@ static int amdgpu_ttm_fill_mem(struct amdgpu_ring *ring,
 	return 0;
 }
 
-/**
- * amdgpu_ttm_clear_buffer - clear memory buffers
- * @bo: amdgpu buffer object
- * @resv: reservation object
- * @fence: dma_fence associated with the operation
- *
- * Clear the memory buffer resource.
- *
- * Returns:
- * 0 for success or a negative error code on failure.
- */
-int amdgpu_ttm_clear_buffer(struct amdgpu_bo *bo,
-			    struct dma_resv *resv,
-			    struct dma_fence **fence)
-{
-	struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
-	struct amdgpu_ring *ring = adev->mman.buffer_funcs_rings[0];
-	struct amdgpu_ttm_entity *entity;
-	struct amdgpu_res_cursor cursor;
-	u64 addr;
-	int r = 0;
-
-	if (!adev->mman.buffer_funcs_enabled)
-		return -EINVAL;
-
-	if (!fence)
-		return -EINVAL;
-	entity = &adev->mman.clear_entities[0];
-	*fence = dma_fence_get_stub();
-
-	amdgpu_res_first(bo->tbo.resource, 0, amdgpu_bo_size(bo), &cursor);
-
-	mutex_lock(&entity->gart_window_lock);
-	while (cursor.remaining) {
-		struct dma_fence *next = NULL;
-		u64 size;
-
-		if (amdgpu_res_cleared(&cursor)) {
-			amdgpu_res_next(&cursor, cursor.size);
-			continue;
-		}
-
-		/* Never clear more than 256MiB at once to avoid timeouts */
-		size = min(cursor.size, 256ULL << 20);
-
-		r = amdgpu_ttm_map_buffer(&entity->base,
-					  &bo->tbo, bo->tbo.resource, &cursor,
-					  entity->gart_window_id1, ring, false, &size, &addr,
-					  NULL, NULL);
-		if (r)
-			goto err;
-
-		r = amdgpu_ttm_fill_mem(ring, &entity->base, 0, addr, size, resv,
-					&next, true,
-					AMDGPU_KERNEL_JOB_ID_TTM_CLEAR_BUFFER);
-		if (r)
-			goto err;
-
-		dma_fence_put(*fence);
-		*fence = next;
-
-		amdgpu_res_next(&cursor, size);
-	}
-err:
-	mutex_unlock(&entity->gart_window_lock);
-
-	return r;
-}
-
 /**
  * amdgpu_fill_buffer - fill a buffer with a given value
  * @entity: optional entity to use. If NULL, the clearing entities will be
@@ -2508,6 +2439,9 @@ int amdgpu_fill_buffer(struct amdgpu_ttm_entity *entity,
 	struct amdgpu_res_cursor dst;
 	uint64_t cur_size, to;
 	int r, e, n_fences;
+	/* The clear flag is only valid directly after allocation. */
+	bool consider_clear_flag =
+		src_data == 0 && k_job_id == AMDGPU_KERNEL_JOB_ID_TTM_CLEAR_BUFFER;
 
 	/* The fences will be either added to the resv object or the last fence
 	 * will be returned to the caller. In the latter case, all fill jobs will
@@ -2531,6 +2465,11 @@ int amdgpu_fill_buffer(struct amdgpu_ttm_entity *entity,
 		while (dst.remaining) {
 			cur_size = min(dst.size, 256ULL << 20);
 
+			if (consider_clear_flag && amdgpu_res_cleared(&dst)) {
+				amdgpu_res_next(&dst, dst.size);
+				continue;
+			}
+
 			n_fences += 1;
 			amdgpu_res_next(&dst, cur_size);
 		}
@@ -2550,6 +2489,11 @@ int amdgpu_fill_buffer(struct amdgpu_ttm_entity *entity,
 	amdgpu_res_first(bo->tbo.resource, 0, amdgpu_bo_size(bo), &dst);
 
 	while (dst.remaining) {
+		if (consider_clear_flag && amdgpu_res_cleared(&dst)) {
+			amdgpu_res_next(&dst, dst.size);
+			continue;
+		}
+
 		/* Never fill more than 256MiB at once to avoid timeouts */
 		cur_size = min(dst.size, 256ULL << 20);
 
@@ -2574,8 +2518,10 @@ int amdgpu_fill_buffer(struct amdgpu_ttm_entity *entity,
 			goto error;
 		}
 
+
 		r = amdgpu_ttm_fill_mem(ring, &entity->base,
-					src_data, to, cur_size, resv,
+					src_data, to, cur_size,
+					resv,
 					&fence, true, k_job_id);
 		if (r) {
 			mutex_unlock(&entity->gart_window_lock);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
index c059a3d52b57..97e73919cb0c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.h
@@ -182,9 +182,6 @@ int amdgpu_copy_buffer(struct amdgpu_ring *ring,
 		       struct dma_resv *resv,
 		       struct dma_fence **fence,
 		       bool vm_needs_flush, uint32_t copy_flags);
-int amdgpu_ttm_clear_buffer(struct amdgpu_bo *bo,
-			    struct dma_resv *resv,
-			    struct dma_fence **fence);
 int amdgpu_fill_buffer(struct amdgpu_ttm_entity *entity,
 		       struct amdgpu_bo *bo,
 		       uint32_t src_data,
-- 
2.43.0