commit 91acbeb68ab10c0c0f65f30b5b7fddbde4c97dd2
author Christian König <christian.koenig@amd.com> Mon Dec 14 16:42:31 2015 +0100
committer Alex Deucher <alexander.deucher@amd.com> Wed Dec 16 17:48:59 2015 -0500
tree fca0b931a3679b8847a88000066fc9ef8a076683
parent 4655a12b81edab7cc7b13ca4db4094792fb01b4a

drm/amdgpu: fix user fence handling

This fixes a random corruption under memory pressure. We need to fence
the BO for the user fence as well, otherwise it might be swapped out
and the GPU could write the fence value to an undesired location.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
index 4f352ec..25a3e248 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
@@ -127,6 +127,37 @@
 	return 0;
 }
 
+static int amdgpu_cs_user_fence_chunk(struct amdgpu_cs_parser *p,
+				      struct drm_amdgpu_cs_chunk_fence *fence_data)
+{
+	struct drm_gem_object *gobj;
+	uint32_t handle;
+
+	handle = fence_data->handle;
+	gobj = drm_gem_object_lookup(p->adev->ddev, p->filp,
+				     fence_data->handle);
+	if (gobj == NULL)
+		return -EINVAL;
+
+	p->uf.bo = amdgpu_bo_ref(gem_to_amdgpu_bo(gobj));
+	p->uf.offset = fence_data->offset;
+
+	if (amdgpu_ttm_tt_has_userptr(p->uf.bo->tbo.ttm)) {
+		drm_gem_object_unreference_unlocked(gobj);
+		return -EINVAL;
+	}
+
+	p->uf_entry.robj = amdgpu_bo_ref(p->uf.bo);
+	p->uf_entry.prefered_domains = AMDGPU_GEM_DOMAIN_GTT;
+	p->uf_entry.allowed_domains = AMDGPU_GEM_DOMAIN_GTT;
+	p->uf_entry.priority = 0;
+	p->uf_entry.tv.bo = &p->uf_entry.robj->tbo;
+	p->uf_entry.tv.shared = true;
+
+	drm_gem_object_unreference_unlocked(gobj);
+	return 0;
+}
+
 int amdgpu_cs_parser_init(struct amdgpu_cs_parser *p, void *data)
 {
 	union drm_amdgpu_cs *cs = data;
@@ -207,28 +238,15 @@
 
 		case AMDGPU_CHUNK_ID_FENCE:
 			size = sizeof(struct drm_amdgpu_cs_chunk_fence);
-			if (p->chunks[i].length_dw * sizeof(uint32_t) >= size) {
-				uint32_t handle;
-				struct drm_gem_object *gobj;
-				struct drm_amdgpu_cs_chunk_fence *fence_data;
-
-				fence_data = (void *)p->chunks[i].kdata;
-				handle = fence_data->handle;
-				gobj = drm_gem_object_lookup(p->adev->ddev,
-							     p->filp, handle);
-				if (gobj == NULL) {
-					ret = -EINVAL;
-					goto free_partial_kdata;
-				}
-
-				p->uf.bo = gem_to_amdgpu_bo(gobj);
-				amdgpu_bo_ref(p->uf.bo);
-				drm_gem_object_unreference_unlocked(gobj);
-				p->uf.offset = fence_data->offset;
-			} else {
+			if (p->chunks[i].length_dw * sizeof(uint32_t) < size) {
 				ret = -EINVAL;
 				goto free_partial_kdata;
 			}
+
+			ret = amdgpu_cs_user_fence_chunk(p, (void *)p->chunks[i].kdata);
+			if (ret)
+				goto free_partial_kdata;
+
 			break;
 
 		case AMDGPU_CHUNK_ID_DEPENDENCIES:
@@ -391,6 +409,9 @@
 	p->vm_bos = amdgpu_vm_get_bos(p->adev, &fpriv->vm,
 				      &p->validated);
 
+	if (p->uf.bo)
+		list_add(&p->uf_entry.tv.head, &p->validated);
+
 	if (need_mmap_lock)
 		down_read(&current->mm->mmap_sem);
 
@@ -488,8 +509,8 @@
 		for (i = 0; i < parser->num_ibs; i++)
 			amdgpu_ib_free(parser->adev, &parser->ibs[i]);
 	kfree(parser->ibs);
-	if (parser->uf.bo)
-		amdgpu_bo_unref(&parser->uf.bo);
+	amdgpu_bo_unref(&parser->uf.bo);
+	amdgpu_bo_unref(&parser->uf_entry.robj);
 }
 
 static int amdgpu_bo_vm_update_pte(struct amdgpu_cs_parser *p,