revert MCLGETI for re(4) for now, it is causing hangs (in some cases

temporary, in others apparently permanent) with high rates of input
packets.

ok deraadt@

1 files changed, 53 insertions, 41 deletions

diff --git a/sys/dev/ic/re.c b/sys/dev/ic/re.c
index 0fdd6260187..ca949d503ea 100644
--- a/sys/dev/ic/re.c
+++ b/sys/dev/ic/re.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: re.c,v 1.129 2010/10/05 08:57:34 mikeb Exp $	*/
+/*	$OpenBSD: re.c,v 1.130 2010/11/12 22:17:30 sthen Exp $	*/
 /*	$FreeBSD: if_re.c,v 1.31 2004/09/04 07:54:05 ru Exp $	*/
 /*
  * Copyright (c) 1997, 1998-2003
@@ -162,9 +162,8 @@ static inline void re_set_bufaddr(struct rl_desc *, bus_addr_t);
 
 int	re_encap(struct rl_softc *, struct mbuf *, int *);
 
-int	re_newbuf(struct rl_softc *);
+int	re_newbuf(struct rl_softc *, int, struct mbuf *);
 int	re_rx_list_init(struct rl_softc *);
-void	re_rx_list_fill(struct rl_softc *);
 int	re_tx_list_init(struct rl_softc *);
 int	re_rxeof(struct rl_softc *);
 int	re_txeof(struct rl_softc *);
@@ -1109,8 +1108,6 @@ re_attach(struct rl_softc *sc, const char *intrstr)
 	IFQ_SET_MAXLEN(&ifp->if_snd, RL_TX_QLEN);
 	IFQ_SET_READY(&ifp->if_snd);
 
-	m_clsetwms(ifp, MCLBYTES, 2, RL_RX_DESC_CNT);
-
 	ifp->if_capabilities = IFCAP_VLAN_MTU | IFCAP_CSUM_IPv4 |
 			       IFCAP_CSUM_TCPv4 | IFCAP_CSUM_UDPv4;
 
@@ -1215,18 +1212,28 @@ fail_0:
 
 
 int
-re_newbuf(struct rl_softc *sc)
+re_newbuf(struct rl_softc *sc, int idx, struct mbuf *m)
 {
-	struct mbuf	*m;
+	struct mbuf	*n = NULL;
 	bus_dmamap_t	map;
 	struct rl_desc	*d;
 	struct rl_rxsoft *rxs;
 	u_int32_t	cmdstat;
-	int		error, idx;
+	int		error;
 
-	m = MCLGETI(NULL, M_DONTWAIT, &sc->sc_arpcom.ac_if, MCLBYTES);
-	if (!m)
-		return (ENOBUFS);
+	if (m == NULL) {
+		MGETHDR(n, M_DONTWAIT, MT_DATA);
+		if (n == NULL)
+			return (ENOBUFS);
+
+		MCLGET(n, M_DONTWAIT);
+		if (!(n->m_flags & M_EXT)) {
+			m_freem(n);
+			return (ENOBUFS);
+		}
+		m = n;
+	} else
+		m->m_data = m->m_ext.ext_buf;
 
 	/*
 	 * Initialize mbuf length fields and fixup
@@ -1236,15 +1243,13 @@ re_newbuf(struct rl_softc *sc)
 	m->m_len = m->m_pkthdr.len = RE_RX_DESC_BUFLEN;
 	m->m_data += RE_ETHER_ALIGN;
 
-	idx = sc->rl_ldata.rl_rx_prodidx;
 	rxs = &sc->rl_ldata.rl_rxsoft[idx];
 	map = rxs->rxs_dmamap;
 	error = bus_dmamap_load_mbuf(sc->sc_dmat, map, m,
 	    BUS_DMA_READ|BUS_DMA_NOWAIT);
-	if (error) {
-		m_freem(m);
-		return (ENOBUFS);
-	}
+
+	if (error)
+		goto out;
 
 	bus_dmamap_sync(sc->sc_dmat, map, 0, map->dm_mapsize,
 	    BUS_DMASYNC_PREREAD);
@@ -1256,8 +1261,7 @@ re_newbuf(struct rl_softc *sc)
 	if (cmdstat & RL_RDESC_STAT_OWN) {
 		printf("%s: tried to map busy RX descriptor\n",
 		    sc->sc_dev.dv_xname);
-		m_freem(m);
-		return (ENOBUFS);
+		goto out;
 	}
 
 	rxs->rxs_mbuf = m;
@@ -1273,10 +1277,11 @@ re_newbuf(struct rl_softc *sc)
 	d->rl_cmdstat = htole32(cmdstat);
 	RL_RXDESCSYNC(sc, idx, BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
 
-	sc->rl_ldata.rl_rx_prodidx = RL_NEXT_RX_DESC(sc, idx);
-	sc->rl_ldata.rl_rx_cnt++;
-
 	return (0);
+ out:
+	if (n != NULL)
+		m_freem(n);
+	return (ENOMEM);
 }
 
 
@@ -1305,27 +1310,21 @@ re_tx_list_init(struct rl_softc *sc)
 int
 re_rx_list_init(struct rl_softc *sc)
 {
-	bzero(sc->rl_ldata.rl_rx_list, RL_RX_LIST_SZ);
+	int	i;
+
+	memset((char *)sc->rl_ldata.rl_rx_list, 0, RL_RX_LIST_SZ);
+
+	for (i = 0; i < RL_RX_DESC_CNT; i++) {
+		if (re_newbuf(sc, i, NULL) == ENOBUFS)
+			return (ENOBUFS);
+	}
 
 	sc->rl_ldata.rl_rx_prodidx = 0;
-	sc->rl_ldata.rl_rx_considx = 0;
-	sc->rl_ldata.rl_rx_cnt = 0;
 	sc->rl_head = sc->rl_tail = NULL;
 
-	re_rx_list_fill(sc);
-
 	return (0);
 }
 
-void
-re_rx_list_fill(struct rl_softc *sc)
-{
-	while (sc->rl_ldata.rl_rx_cnt < RL_RX_DESC_CNT) {
-		if (re_newbuf(sc) == ENOBUFS)
-			break;
-	}
-}
-
 /*
  * RX handler for C+ and 8169. For the gigE chips, we support
  * the reception of jumbo frames that have been fragmented
@@ -1343,8 +1342,7 @@ re_rxeof(struct rl_softc *sc)
 
 	ifp = &sc->sc_arpcom.ac_if;
 
-	for (i = sc->rl_ldata.rl_rx_considx; sc->rl_ldata.rl_rx_cnt > 0;
-	     i = RL_NEXT_RX_DESC(sc, i)) {
+	for (i = sc->rl_ldata.rl_rx_prodidx;; i = RL_NEXT_RX_DESC(sc, i)) {
 		cur_rx = &sc->rl_ldata.rl_rx_list[i];
 		RL_RXDESCSYNC(sc, i,
 		    BUS_DMASYNC_POSTREAD|BUS_DMASYNC_POSTWRITE);
@@ -1356,8 +1354,6 @@ re_rxeof(struct rl_softc *sc)
 		total_len = rxstat & sc->rl_rxlenmask;
 		rxs = &sc->rl_ldata.rl_rxsoft[i];
 		m = rxs->rxs_mbuf;
-		rxs->rxs_mbuf = NULL;
-		sc->rl_ldata.rl_rx_cnt--;
 		rx = 1;
 
 		/* Invalidate the RX mbuf and unload its map */
@@ -1376,6 +1372,7 @@ re_rxeof(struct rl_softc *sc)
 				sc->rl_tail->m_next = m;
 				sc->rl_tail = m;
 			}
+			re_newbuf(sc, i, NULL);
 			continue;
 		}
 
@@ -1413,6 +1410,22 @@ re_rxeof(struct rl_softc *sc)
 				m_freem(sc->rl_head);
 				sc->rl_head = sc->rl_tail = NULL;
 			}
+			re_newbuf(sc, i, m);
+			continue;
+		}
+
+		/*
+		 * If allocating a replacement mbuf fails,
+		 * reload the current one.
+		 */
+
+		if (re_newbuf(sc, i, NULL)) {
+			ifp->if_ierrors++;
+			if (sc->rl_head != NULL) {
+				m_freem(sc->rl_head);
+				sc->rl_head = sc->rl_tail = NULL;
+			}
+			re_newbuf(sc, i, m);
 			continue;
 		}
 
@@ -1490,8 +1503,7 @@ re_rxeof(struct rl_softc *sc)
 		ether_input_mbuf(ifp, m);
 	}
 
-	sc->rl_ldata.rl_rx_considx = i;
-	re_rx_list_fill(sc);
+	sc->rl_ldata.rl_rx_prodidx = i;
 
 	return (rx);
 }