static void
ffec_rxfinish_locked(struct ffec_softc *sc)
{
struct ffec_hwdesc *desc;
int len;
boolean_t produced_empty_buffer;
FFEC_ASSERT_LOCKED(sc);
produced_empty_buffer = false;
for (;;) {
desc = &sc->rxdesc_ring[sc->rx_idx];
if (desc->flags_len & FEC_RXDESC_EMPTY)
break;
produced_empty_buffer = true;
len = (desc->flags_len & FEC_RXDESC_LEN_MASK);
if (len < 64) {
/*
* Just recycle the descriptor and continue. .
*/
ffec_setup_rxdesc(sc, sc->rx_idx,
sc->rxdesc_ring[sc->rx_idx].buf_paddr);
} else if ((desc->flags_len & FEC_RXDESC_L) == 0) {
/*
* The entire frame is not in this buffer. Impossible.
* Recycle the descriptor and continue.
*
* XXX what's the right way to handle this? Probably we
* should stop/init the hardware because this should
* just really never happen when we have buffers bigger
* than the maximum frame size.
*/
device_printf(sc->dev,
"fec_rxfinish: received frame without LAST bit set");
ffec_setup_rxdesc(sc, sc->rx_idx,
sc->rxdesc_ring[sc->rx_idx].buf_paddr);
} else if (desc->flags_len & FEC_RXDESC_ERROR_BITS) {
/*
* Something went wrong with receiving the frame, we
* don't care what (the hardware has counted the error
* in the stats registers already), we just reuse the
* same mbuf, which is still dma-mapped, by resetting
* the rx descriptor.
*/
ffec_setup_rxdesc(sc, sc->rx_idx,
sc->rxdesc_ring[sc->rx_idx].buf_paddr);
} else {
/*
* Normal case: a good frame all in one buffer.
*/
ffec_rxfinish_onebuf(sc, len);
}
sc->rx_idx = next_rxidx(sc, sc->rx_idx);
}
if (produced_empty_buffer) {
WR4(sc, FEC_RDAR_REG, FEC_RDAR_RDAR);
}
}
static int
ffec_setup_rxbuf(struct ffec_softc *sc, int idx, struct mbuf * m)
{
int error, nsegs;
struct bus_dma_segment seg;
/*
* We need to leave at least ETHER_ALIGN bytes free at the beginning of
* the buffer to allow the data to be re-aligned after receiving it (by
* copying it backwards ETHER_ALIGN bytes in the same buffer). We also
* have to ensure that the beginning of the buffer is aligned to the
* hardware's requirements.
*/
m_adj(m, roundup(ETHER_ALIGN, FEC_RXBUF_ALIGN));
error = bus_dmamap_load_mbuf_sg(sc->rxbuf_tag, sc->rxbuf_map[idx].map,
m, &seg, &nsegs, 0);
if (error != 0) {
return (error);
}
bus_dmamap_sync(sc->rxbuf_tag, sc->rxbuf_map[idx].map,
BUS_DMASYNC_PREREAD);
sc->rxbuf_map[idx].mbuf = m;
ffec_setup_rxdesc(sc, idx, seg.ds_addr);
return (0);
}
static void
ffec_rxfinish_onebuf(struct ffec_softc *sc, int len)
{
struct mbuf *m, *newmbuf;
struct ffec_bufmap *bmap;
uint8_t *dst, *src;
int error;
/*
* First try to get a new mbuf to plug into this slot in the rx ring.
* If that fails, drop the current packet and recycle the current
* mbuf, which is still mapped and loaded.
*/
if ((newmbuf = ffec_alloc_mbufcl(sc)) == NULL) {
if_inc_counter(sc->ifp, IFCOUNTER_IQDROPS, 1);
ffec_setup_rxdesc(sc, sc->rx_idx,
sc->rxdesc_ring[sc->rx_idx].buf_paddr);
return;
}
/*
* Unfortunately, the protocol headers need to be aligned on a 32-bit
* boundary for the upper layers. The hardware requires receive
* buffers to be 16-byte aligned. The ethernet header is 14 bytes,
* leaving the protocol header unaligned. We used m_adj() after
* allocating the buffer to leave empty space at the start of the
* buffer, now we'll use the alignment agnostic bcopy() routine to
* shuffle all the data backwards 2 bytes and adjust m_data.
*
* XXX imx6 hardware is able to do this 2-byte alignment by setting the
* SHIFT16 bit in the RACC register. Older hardware doesn't have that
* feature, but for them could we speed this up by copying just the
* protocol headers into their own small mbuf then chaining the cluster
* to it? That way we'd only need to copy like 64 bytes or whatever
* the biggest header is, instead of the whole 1530ish-byte frame.
*/
FFEC_UNLOCK(sc);
bmap = &sc->rxbuf_map[sc->rx_idx];
len -= ETHER_CRC_LEN;
bus_dmamap_sync(sc->rxbuf_tag, bmap->map, BUS_DMASYNC_POSTREAD);
bus_dmamap_unload(sc->rxbuf_tag, bmap->map);
m = bmap->mbuf;
bmap->mbuf = NULL;
m->m_len = len;
m->m_pkthdr.len = len;
m->m_pkthdr.rcvif = sc->ifp;
src = mtod(m, uint8_t*);
dst = src - ETHER_ALIGN;
bcopy(src, dst, len);
m->m_data = dst;
sc->ifp->if_input(sc->ifp, m);
FFEC_LOCK(sc);
if ((error = ffec_setup_rxbuf(sc, sc->rx_idx, newmbuf)) != 0) {
device_printf(sc->dev, "ffec_setup_rxbuf error %d\n", error);
/* XXX Now what? We've got a hole in the rx ring. */
}
}
