amd/amdgpu: Inherit coherence flags base on original BO flags

For SG BO to DMA-map userptrs on other GPUs, the SG BO
need inherit MTYPEs in PTEs from original BO.

If we set the flags, the device can be coherent with
the CPUs and other GPUs.

v2:
  1. Drop unnecessary flags check
  2. Remove local variable align
Signed-off-by: Shane Xiao <shane.xiao@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -272,15 +272,19 @@ create_dmamap_sg_bo(struct amdgpu_device *adev,
 		 struct kgd_mem *mem, struct amdgpu_bo **bo_out)
 {
 	struct drm_gem_object *gem_obj;
-	int ret, align;
+	int ret;
+	uint64_t flags = 0;
 
 	ret = amdgpu_bo_reserve(mem->bo, false);
 	if (ret)
 		return ret;
 
-	align = 1;
-	ret = amdgpu_gem_object_create(adev, mem->bo->tbo.base.size, align,
-			AMDGPU_GEM_DOMAIN_CPU, AMDGPU_GEM_CREATE_PREEMPTIBLE,
+	if (mem->alloc_flags & KFD_IOC_ALLOC_MEM_FLAGS_USERPTR)
+		flags |= mem->bo->flags & (AMDGPU_GEM_CREATE_COHERENT |
+					AMDGPU_GEM_CREATE_UNCACHED);
+
+	ret = amdgpu_gem_object_create(adev, mem->bo->tbo.base.size, 1,
+			AMDGPU_GEM_DOMAIN_CPU, AMDGPU_GEM_CREATE_PREEMPTIBLE | flags,
 			ttm_bo_type_sg, mem->bo->tbo.base.resv, &gem_obj);
 
 	amdgpu_bo_unreserve(mem->bo);