drm/amdgpu: fix contiguous handling for IB parsing v2

Otherwise we won't get correct access to the IB.

v2: keep setting AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS to avoid problems in
    the VRAM backend.
Signed-off-by: Christian König <christian.koenig@amd.com>
Closes: https://gitlab.freedesktop.org/drm/amd/-/issues/3501
Fixes: e362b7c8 ("drm/amdgpu: Modify the contiguous flags behaviour")
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
Tested-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit fbfb5f03)

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

@@ -1778,7 +1778,7 @@ int amdgpu_cs_find_mapping(struct amdgpu_cs_parser *parser,
 	struct ttm_operation_ctx ctx = { false, false };
 	struct amdgpu_vm *vm = &fpriv->vm;
 	struct amdgpu_bo_va_mapping *mapping;
-	int r;
+	int i, r;
 
 	addr /= AMDGPU_GPU_PAGE_SIZE;
 
@@ -1793,13 +1793,13 @@ int amdgpu_cs_find_mapping(struct amdgpu_cs_parser *parser,
 	if (dma_resv_locking_ctx((*bo)->tbo.base.resv) != &parser->exec.ticket)
 		return -EINVAL;
 
-	if (!((*bo)->flags & AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS)) {
 	(*bo)->flags |= AMDGPU_GEM_CREATE_VRAM_CONTIGUOUS;
 	amdgpu_bo_placement_from_domain(*bo, (*bo)->allowed_domains);
+	for (i = 0; i < (*bo)->placement.num_placement; i++)
+		(*bo)->placements[i].flags |= TTM_PL_FLAG_CONTIGUOUS;
 	r = ttm_bo_validate(&(*bo)->tbo, &(*bo)->placement, &ctx);
 	if (r)
 		return r;
-	}
 
 	return amdgpu_ttm_alloc_gart(&(*bo)->tbo);
 }