PR_STXCS
if ((mfpr(PR_STXCS) & STXCS_RDY) == 0)
mtpr(bp->b_blkno<<8 | STXCS_IE | CRL_F_READ, PR_STXCS);
mtpr(bp->b_blkno<<8 | STXCS_IE | CRL_F_WRITE, PR_STXCS);
i = mfpr(PR_STXCS);
mtpr(bp->b_blkno<<8 | STXCS_IE | CRL_F_WRITE, PR_STXCS);
mtpr(bp->b_blkno<<8 | STXCS_IE | CRL_F_READ, PR_STXCS);
mtpr(STXCS_IE | CRL_F_RETSTS, PR_STXCS);
mtpr(STXCS_IE | CRL_S_RETSTS, PR_STXCS);
mtpr(STXCS_IE | CRL_F_ABORT, PR_STXCS);