infix
rq->infix = intel_ring_offset(rq, cs);
rq->infix = rq->ring->emit; /* end of header; start of user payload */
head = rq->infix;
if (rq->infix == rq->postfix)
rq->infix = rq->postfix;
u32 infix;
FILE *infix(struct header *, FILE *);
if ((mtf = infix(hp, mtf)) == NULL) {