drm/amdgpu: fix lru size grouping v2

Adding a BO can make it the insertion point for larger sizes as well.

v2: add a comment about the guard structure.

Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
index 8c704c8..700c56b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
@@ -426,6 +426,8 @@
 
 	/* custom LRU management */
 	struct amdgpu_mman_lru			log2_size[AMDGPU_TTM_LRU_SIZE];
+	/* guard for log2_size array, don't add anything in between */
+	struct amdgpu_mman_lru			guard;
 };
 
 int amdgpu_copy_buffer(struct amdgpu_ring *ring,