RING_OP1_CR_ENQ_PTR
enqueue_ptr = FIELD_GET(RING_OP1_CR_ENQ_PTR, op1_val);
op1_val &= ~RING_OP1_CR_ENQ_PTR;
op1_val |= FIELD_PREP(RING_OP1_CR_ENQ_PTR, enqueue_ptr);