XC_WAIT
xmp->xc_state = XC_WAIT;
ASSERT(xc_mbox[cix].xc_state == XC_WAIT);
while (xc_mbox[cix].xc_state != XC_WAIT) {
SEND_MBOX_ONLY(xc_cpuset, func, arg1, arg2, lcx, XC_WAIT);
WAIT_MBOX_DONE(xc_cpuset, lcx, XC_WAIT, 0);
SEND_MBOX_ONLY(xc_cpuset, func, arg1, arg2, lcx, XC_WAIT);
WAIT_MBOX_DONE(xc_cpuset, lcx, XC_WAIT, 0);
if (xc_mbox[pix].xc_state == XC_WAIT) {
xmp->xc_state = XC_WAIT;