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authorDavid Gwynne <dlg@cvs.openbsd.org>2015-11-09 00:29:07 +0000
committerDavid Gwynne <dlg@cvs.openbsd.org>2015-11-09 00:29:07 +0000
commit0d86db08091aec725d213488e002e692ae87610f (patch)
tree842b84c10208a30f61622b75e65e9c8740631c9d /sys/dev/pci/if_ale.c
parentd1a8c3966d4b13ef9211587439a4896144eafcf1 (diff)
rework the start routines to avoid IF_PREPEND.
IF_PREPEND assumes the underlying send queue is priq, while hfsc may be enabled on it. the previous code pattern to DEQUEUE, try and encap the mbuf on the ring, and if that failed cos there was no space it would PREPEND it. now it checks for space on the ring before it attempts to DEQUEUE. failure to encap means the mbuf is now unconditionally dropped.
Diffstat (limited to 'sys/dev/pci/if_ale.c')
-rw-r--r--sys/dev/pci/if_ale.c50
1 files changed, 21 insertions, 29 deletions
diff --git a/sys/dev/pci/if_ale.c b/sys/dev/pci/if_ale.c
index 8622aef9c00..fded56a79b7 100644
--- a/sys/dev/pci/if_ale.c
+++ b/sys/dev/pci/if_ale.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: if_ale.c,v 1.40 2015/10/25 13:04:28 mpi Exp $ */
+/* $OpenBSD: if_ale.c,v 1.41 2015/11/09 00:29:06 dlg Exp $ */
/*-
* Copyright (c) 2008, Pyun YongHyeon <yongari@FreeBSD.org>
* All rights reserved.
@@ -96,7 +96,7 @@ void ale_txeof(struct ale_softc *);
int ale_dma_alloc(struct ale_softc *);
void ale_dma_free(struct ale_softc *);
-int ale_encap(struct ale_softc *, struct mbuf **);
+int ale_encap(struct ale_softc *, struct mbuf *);
void ale_init_rx_pages(struct ale_softc *);
void ale_init_tx_ring(struct ale_softc *);
@@ -866,16 +866,14 @@ ale_dma_free(struct ale_softc *sc)
}
int
-ale_encap(struct ale_softc *sc, struct mbuf **m_head)
+ale_encap(struct ale_softc *sc, struct mbuf *m)
{
struct ale_txdesc *txd, *txd_last;
struct tx_desc *desc;
- struct mbuf *m;
bus_dmamap_t map;
uint32_t cflags, poff, vtag;
int error, i, prod;
- m = *m_head;
cflags = vtag = 0;
poff = 0;
@@ -884,30 +882,23 @@ ale_encap(struct ale_softc *sc, struct mbuf **m_head)
txd_last = txd;
map = txd->tx_dmamap;
- error = bus_dmamap_load_mbuf(sc->sc_dmat, map, *m_head, BUS_DMA_NOWAIT);
+ error = bus_dmamap_load_mbuf(sc->sc_dmat, map, m, BUS_DMA_NOWAIT);
if (error != 0 && error != EFBIG)
goto drop;
if (error != 0) {
- if (m_defrag(*m_head, M_DONTWAIT)) {
+ if (m_defrag(m, M_DONTWAIT)) {
error = ENOBUFS;
goto drop;
}
- error = bus_dmamap_load_mbuf(sc->sc_dmat, map, *m_head,
+ error = bus_dmamap_load_mbuf(sc->sc_dmat, map, m,
BUS_DMA_NOWAIT);
if (error != 0)
goto drop;
}
- /* Check descriptor overrun. */
- if (sc->ale_cdata.ale_tx_cnt + map->dm_nsegs >= ALE_TX_RING_CNT - 2) {
- bus_dmamap_unload(sc->sc_dmat, map);
- return (ENOBUFS);
- }
-
bus_dmamap_sync(sc->sc_dmat, map, 0, map->dm_mapsize,
BUS_DMASYNC_PREWRITE);
- m = *m_head;
/* Configure Tx checksum offload. */
if ((m->m_pkthdr.csum_flags & ALE_CSUM_FEATURES) != 0) {
/*
@@ -980,8 +971,7 @@ ale_encap(struct ale_softc *sc, struct mbuf **m_head)
return (0);
drop:
- m_freem(*m_head);
- *m_head = NULL;
+ m_freem(m);
return (error);
}
@@ -989,7 +979,7 @@ void
ale_start(struct ifnet *ifp)
{
struct ale_softc *sc = ifp->if_softc;
- struct mbuf *m_head;
+ struct mbuf *m;
int enq;
/* Reclaim transmitted frames. */
@@ -1005,8 +995,15 @@ ale_start(struct ifnet *ifp)
enq = 0;
for (;;) {
- IFQ_DEQUEUE(&ifp->if_snd, m_head);
- if (m_head == NULL)
+ /* Check descriptor overrun. */
+ if (sc->ale_cdata.ale_tx_cnt + ALE_MAXTXSEGS >=
+ ALE_TX_RING_CNT - 2) {
+ ifp->if_flags |= IFF_OACTIVE;
+ break;
+ }
+
+ IFQ_DEQUEUE(&ifp->if_snd, m);
+ if (m == NULL)
break;
/*
@@ -1014,14 +1011,9 @@ ale_start(struct ifnet *ifp)
* don't have room, set the OACTIVE flag and wait
* for the NIC to drain the ring.
*/
- if (ale_encap(sc, &m_head)) {
- if (m_head == NULL)
- ifp->if_oerrors++;
- else {
- IF_PREPEND(&ifp->if_snd, m_head);
- ifp->if_flags |= IFF_OACTIVE;
- }
- break;
+ if (ale_encap(sc, m) != 0) {
+ ifp->if_oerrors++;
+ continue;
}
enq = 1;
@@ -1032,7 +1024,7 @@ ale_start(struct ifnet *ifp)
* to him.
*/
if (ifp->if_bpf != NULL)
- bpf_mtap_ether(ifp->if_bpf, m_head, BPF_DIRECTION_OUT);
+ bpf_mtap_ether(ifp->if_bpf, m, BPF_DIRECTION_OUT);
#endif
}