drm/amdgpu: enforce AMDGPU_GEM_CREATE_NO_CPU_ACCESS

Deny user and kernel mapping if we said we never want to do so.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Jammy Zhou <Jammy.Zhou@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -316,7 +316,8 @@ int amdgpu_mode_dumb_mmap(struct drm_file *filp,
 		return -ENOENT;
 	}
 	robj = gem_to_amdgpu_bo(gobj);
-	if (amdgpu_ttm_tt_has_userptr(robj->tbo.ttm)) {
+	if (amdgpu_ttm_tt_has_userptr(robj->tbo.ttm) ||
+	    (robj->flags & AMDGPU_GEM_CREATE_NO_CPU_ACCESS)) {
 		drm_gem_object_unreference_unlocked(gobj);
 		return -EPERM;
 	}

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

@@ -263,6 +263,9 @@ int amdgpu_bo_kmap(struct amdgpu_bo *bo, void **ptr)
 	bool is_iomem;
 	int r;
 
+	if (bo->flags & AMDGPU_GEM_CREATE_NO_CPU_ACCESS)
+		return -EPERM;
+
 	if (bo->kptr) {
 		if (ptr) {
 			*ptr = bo->kptr;