drm/amdgpu: add AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS flag v3

Add a flag noting that a BO must be created using linear VRAM
and set this flag on all in kernel users where appropriate.

Hopefully I haven't missed anything.

v2: add it in a few more places, fix CPU mapping.
v3: rename to VRAM_CONTIGUOUS, fix typo in CS code.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Edward O'Callaghan <funfunctor@folklore1984.net>
Tested-by: Mike Lothian <mike@fireburn.co.uk>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
index dcaf691..a06cf99 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
@@ -1119,7 +1119,8 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
 
 	r = amdgpu_bo_create(adev, 256 * 1024, PAGE_SIZE, true,
 			     AMDGPU_GEM_DOMAIN_VRAM,
-			     AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED,
+			     AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED |
+			     AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS,
 			     NULL, NULL, &adev->stollen_vga_memory);
 	if (r) {
 		return r;