BUSMEM_DATASIZE
sc->sc_busmem->shm_first = BUSMEM_DATASIZE;
lastoff += BUSMEM_DATASIZE;
devoff += BUSMEM_DATASIZE;
KASSERT(len < (BUSMEM_DATASIZE/2) && off <= BUSMEM_DATASIZE);
chunk = MIN(len, BUSMEM_DATASIZE - off);
filledbus = (off+chunk == BUSMEM_DATASIZE);
return (off + chunk) % BUSMEM_DATASIZE;
KASSERT(sp.sp_len < BUSMEM_DATASIZE);
if (newoff >= BUSMEM_DATASIZE)
newoff -= BUSMEM_DATASIZE;
KASSERT(len < (BUSMEM_DATASIZE/2) && off <= BUSMEM_DATASIZE);
chunk = MIN(len, BUSMEM_DATASIZE - off);
if (off + chunk == BUSMEM_DATASIZE)
return (off + chunk) % BUSMEM_DATASIZE;
if (curbus == BUSMEM_DATASIZE)