RDOORBELL32       288 drivers/gpu/drm/amd/amdgpu/amdgpu_doorbell.h #define RDOORBELL32(index) amdgpu_mm_rdoorbell(adev, (index))
RDOORBELL32      2569 drivers/gpu/drm/radeon/radeon.h #define RDOORBELL32(index) cik_mm_rdoorbell(rdev, (index))