drm/amdgpu: Use better names to reflect it is CP MQD buffer

Add "CP" to AMDGPU_GEM_CREATE_MQD_GFX9 to indicate it is only for CP MQD
buffer.
Signed-off-by: Yong Zhao <Yong.Zhao@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -224,7 +224,7 @@ void amdgpu_amdkfd_gpu_reset(struct kgd_dev *kgd)
 
 int amdgpu_amdkfd_alloc_gtt_mem(struct kgd_dev *kgd, size_t size,
 				void **mem_obj, uint64_t *gpu_addr,
-				void **cpu_ptr, bool mqd_gfx9)
+				void **cpu_ptr, bool cp_mqd_gfx9)
 {
 	struct amdgpu_device *adev = (struct amdgpu_device *)kgd;
 	struct amdgpu_bo *bo = NULL;
@@ -240,8 +240,8 @@ int amdgpu_amdkfd_alloc_gtt_mem(struct kgd_dev *kgd, size_t size,
 	bp.type = ttm_bo_type_kernel;
 	bp.resv = NULL;
 
-	if (mqd_gfx9)
-		bp.flags |= AMDGPU_GEM_CREATE_MQD_GFX9;
+	if (cp_mqd_gfx9)
+		bp.flags |= AMDGPU_GEM_CREATE_CP_MQD_GFX9;
 
 	r = amdgpu_bo_create(adev, &bp, &bo);
 	if (r) {

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

@@ -1028,7 +1028,7 @@ int amdgpu_ttm_gart_bind(struct amdgpu_device *adev,
 	struct amdgpu_ttm_tt *gtt = (void *)ttm;
 	int r;
 
-	if (abo->flags & AMDGPU_GEM_CREATE_MQD_GFX9) {
+	if (abo->flags & AMDGPU_GEM_CREATE_CP_MQD_GFX9) {
 		uint64_t page_idx = 1;
 
 		r = amdgpu_gart_bind(adev, gtt->offset, page_idx,
@@ -1036,7 +1036,10 @@ int amdgpu_ttm_gart_bind(struct amdgpu_device *adev,
 		if (r)
 			goto gart_bind_fail;
 
-		/* Patch mtype of the second part BO */
+		/* The memory type of the first page defaults to UC. Now
+		 * modify the memory type to NC from the second page of
+		 * the BO onward.
+		 */
 		flags &= ~AMDGPU_PTE_MTYPE_VG10_MASK;
 		flags |= AMDGPU_PTE_MTYPE_VG10(AMDGPU_MTYPE_NC);
 

include/uapi/drm/amdgpu_drm.h

@@ -125,9 +125,10 @@ extern "C" {
 /* Flag that BO sharing will be explicitly synchronized */
 #define AMDGPU_GEM_CREATE_EXPLICIT_SYNC		(1 << 7)
 /* Flag that indicates allocating MQD gart on GFX9, where the mtype
- * for the second page onward should be set to NC.
+ * for the second page onward should be set to NC. It should never
+ * be used by user space applications.
  */
-#define AMDGPU_GEM_CREATE_MQD_GFX9		(1 << 8)
+#define AMDGPU_GEM_CREATE_CP_MQD_GFX9		(1 << 8)
 /* Flag that BO may contain sensitive data that must be wiped before
  * releasing the memory
  */