static void
ata_dbdma_setprd(void *xarg, bus_dma_segment_t *segs, int nsegs, int error)
{
struct ata_dbdma_dmaload_args *arg = xarg;
struct ata_dbdma_channel *sc = arg->sc;
int branch_type, command;
int prev_stop;
int i;
mtx_lock(&sc->dbdma_mtx);
prev_stop = sc->next_dma_slot-1;
if (prev_stop < 0)
prev_stop = 0xff;
for (i = 0; i < nsegs; i++) {
/* Loop back to the beginning if this is our last slot */
if (sc->next_dma_slot == 0xff)
branch_type = DBDMA_ALWAYS;
else
branch_type = DBDMA_NEVER;
if (arg->write) {
command = (i + 1 < nsegs) ? DBDMA_OUTPUT_MORE :
DBDMA_OUTPUT_LAST;
} else {
command = (i + 1 < nsegs) ? DBDMA_INPUT_MORE :
DBDMA_INPUT_LAST;
}
dbdma_insert_command(sc->dbdma, sc->next_dma_slot++,
command, 0, segs[i].ds_addr, segs[i].ds_len,
DBDMA_NEVER, branch_type, DBDMA_NEVER, 0);
if (branch_type == DBDMA_ALWAYS)
sc->next_dma_slot = 0;
}
/* We have a corner case where the STOP command is the last slot,
* but you can't branch in STOP commands. So add a NOP branch here
* and the STOP in slot 0. */
if (sc->next_dma_slot == 0xff) {
dbdma_insert_branch(sc->dbdma, sc->next_dma_slot, 0);
sc->next_dma_slot = 0;
}
#if 0
dbdma_insert_command(sc->dbdma, sc->next_dma_slot++,
DBDMA_NOP, 0, 0, 0, DBDMA_ALWAYS, DBDMA_NEVER, DBDMA_NEVER, 0);
#endif
dbdma_insert_stop(sc->dbdma, sc->next_dma_slot++);
dbdma_insert_nop(sc->dbdma, prev_stop);
dbdma_sync_commands(sc->dbdma, BUS_DMASYNC_PREWRITE);
mtx_unlock(&sc->dbdma_mtx);
arg->nsegs = nsegs;
}
void
dbdma_insert_branch(dbdma_channel_t *chan, int slot, int to_slot)
{
dbdma_insert_command(chan, slot, DBDMA_NOP, 0, 0, 0, DBDMA_NEVER,
DBDMA_ALWAYS, DBDMA_NEVER, to_slot);
}
void
dbdma_insert_nop(dbdma_channel_t *chan, int slot)
{
dbdma_insert_command(chan, slot, DBDMA_NOP, 0, 0, 0, DBDMA_NEVER,
DBDMA_NEVER, DBDMA_NEVER, 0);
}