PCH_TRANS_DATA_M1
I915_WRITE(PCH_TRANS_DATA_M1(pipe), TU_SIZE(m_n->tu) | m_n->gmch_m);
m_n->gmch_m = I915_READ(PCH_TRANS_DATA_M1(pipe))
m_n->tu = ((I915_READ(PCH_TRANS_DATA_M1(pipe))