> On 6 Nov 2015, at 9:35 PM, David Gwynne <[email protected]> wrote:
>
> On Wed, Nov 04, 2015 at 08:18:48AM +0100, Martin Pieuchot wrote:
>> On 04/11/15(Wed) 10:39, David Gwynne wrote:
>>> im working on making the interface send queue mpsafe.
>>>
>>> part of that involced deprecating the IFQ_POLL api because it allows the
>>> caller to get a reference an mbuf that is still on the send queue. this is
>>> dangerous if another cpu tries to manipulate the send queue. instead code
>>> should call IFQ_DEQUEUE, which takes it off the queue for the driver to use.
>>>
>>> however, blindly changing code from IFQ_POLL to IFQ_DEQUEUE will
>>> cause unwanted packet loss when encapsulation fails in some cases,
>>> such as when the tx ring is already full. to cope, the easiest
>>> solution is to requeue the packet so the next call to the start
>>> routine can try fitting it on the ring again.
>>>
>>> this introduces IFQ_PREPEND (cause we currently have IF_PREPEND)
>>> and works on top of both hfsc and priq because i added hfsc_requeue
>>> a while back.
>>>
>>> this also converts uses of IF_PREPEND in drivers to IFQ_PREPEND.
>>> this improves the situation a bit if people have decided to use
>>> hfsc on these interfaces.
>
> ok, so after talking to kenjiro cho about the problems with IFQ_PREPEND
> and arbitrary queuing disciplines, im taking a step back while
> thinking about how to approach the send queue stuff for a bit.
> however, deprecating IF_PREPEND is still necessary.
>
> this tweaks the relevant drivers to not need IF_PREPEND. note that
> these are non-trivial changes, so i would like some review and maybe
> some actual testing? especially on vr, im sure there are a lot of
> users.
>
> most of the changes are just shuffling conditionals around, but vr
> also includes a change to use m_defrag. im not sure that is enough
> to satisfy the alignment requirements the code discusses, so testing
> is necessary. and at least one of age, alc, or ale.
noone has a vr?
>
> ok?
>
> Index: if_age.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/pci/if_age.c,v
> retrieving revision 1.29
> diff -u -p -r1.29 if_age.c
> --- if_age.c 25 Oct 2015 13:04:28 -0000 1.29
> +++ if_age.c 6 Nov 2015 11:27:04 -0000
> @@ -89,7 +89,7 @@ void age_dma_free(struct age_softc *);
> void age_get_macaddr(struct age_softc *);
> void age_phy_reset(struct age_softc *);
>
> -int age_encap(struct age_softc *, struct mbuf **);
> +int age_encap(struct age_softc *, struct mbuf *);
> void age_init_tx_ring(struct age_softc *);
> int age_init_rx_ring(struct age_softc *);
> void age_init_rr_ring(struct age_softc *);
> @@ -957,7 +957,7 @@ void
> age_start(struct ifnet *ifp)
> {
> struct age_softc *sc = ifp->if_softc;
> - struct mbuf *m_head;
> + struct mbuf *m;
> int enq;
>
> if ((ifp->if_flags & (IFF_RUNNING | IFF_OACTIVE)) != IFF_RUNNING)
> @@ -969,8 +969,14 @@ age_start(struct ifnet *ifp)
>
> enq = 0;
> for (;;) {
> - IFQ_DEQUEUE(&ifp->if_snd, m_head);
> - if (m_head == NULL)
> + if (sc->age_cdata.age_tx_cnt + AGE_MAXTXSEGS >=
> + AGE_TX_RING_CNT - 2) {
> + ifp->if_flags |= IFF_OACTIVE;
> + break;
> + }
> +
> + IFQ_DEQUEUE(&ifp->if_snd, m);
> + if (m == NULL)
> break;
>
> /*
> @@ -978,14 +984,9 @@ age_start(struct ifnet *ifp)
> * don't have room, set the OACTIVE flag and wait
> * for the NIC to drain the ring.
> */
> - if (age_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 (age_encap(sc, m) != 0) {
> + ifp->if_oerrors++;
> + continue;
> }
> enq = 1;
>
> @@ -995,7 +996,7 @@ age_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
> }
>
> @@ -1115,16 +1116,14 @@ age_mac_config(struct age_softc *sc)
> }
>
> int
> -age_encap(struct age_softc *sc, struct mbuf **m_head)
> +age_encap(struct age_softc *sc, struct mbuf *m)
> {
> struct age_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;
>
> @@ -1133,27 +1132,20 @@ age_encap(struct age_softc *sc, struct m
> 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->age_cdata.age_tx_cnt + map->dm_nsegs >= AGE_TX_RING_CNT - 2) {
> - bus_dmamap_unload(sc->sc_dmat, map);
> - return (ENOBUFS);
> - }
> -
> - m = *m_head;
> /* Configure Tx IP/TCP/UDP checksum offload. */
> if ((m->m_pkthdr.csum_flags & AGE_CSUM_FEATURES) != 0) {
> cflags |= AGE_TD_CSUM;
> @@ -1210,8 +1202,7 @@ age_encap(struct age_softc *sc, struct m
> return (0);
>
> drop:
> - m_freem(*m_head);
> - *m_head = NULL;
> + m_freem(m);
> return (error);
> }
>
> Index: if_alc.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/pci/if_alc.c,v
> retrieving revision 1.35
> diff -u -p -r1.35 if_alc.c
> --- if_alc.c 25 Oct 2015 13:04:28 -0000 1.35
> +++ if_alc.c 6 Nov 2015 11:27:04 -0000
> @@ -83,7 +83,7 @@ void alc_aspm(struct alc_softc *, uint64
> void alc_disable_l0s_l1(struct alc_softc *);
> int alc_dma_alloc(struct alc_softc *);
> void alc_dma_free(struct alc_softc *);
> -int alc_encap(struct alc_softc *, struct mbuf **);
> +int alc_encap(struct alc_softc *, struct mbuf *);
> void alc_get_macaddr(struct alc_softc *);
> void alc_init_cmb(struct alc_softc *);
> void alc_init_rr_ring(struct alc_softc *);
> @@ -1265,16 +1265,14 @@ alc_dma_free(struct alc_softc *sc)
> }
>
> int
> -alc_encap(struct alc_softc *sc, struct mbuf **m_head)
> +alc_encap(struct alc_softc *sc, struct mbuf *m)
> {
> struct alc_txdesc *txd, *txd_last;
> struct tx_desc *desc;
> - struct mbuf *m;
> bus_dmamap_t map;
> uint32_t cflags, poff, vtag;
> int error, idx, prod;
>
> - m = *m_head;
> cflags = vtag = 0;
> poff = 0;
>
> @@ -1283,30 +1281,23 @@ alc_encap(struct alc_softc *sc, struct m
> 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->alc_cdata.alc_tx_cnt + map->dm_nsegs >= ALC_TX_RING_CNT - 3) {
> - 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;
> desc = NULL;
> idx = 0;
> #if NVLAN > 0
> @@ -1353,8 +1344,7 @@ alc_encap(struct alc_softc *sc, struct m
> return (0);
>
> drop:
> - m_freem(*m_head);
> - *m_head = NULL;
> + m_freem(m);
> return (error);
> }
>
> @@ -1362,7 +1352,7 @@ void
> alc_start(struct ifnet *ifp)
> {
> struct alc_softc *sc = ifp->if_softc;
> - struct mbuf *m_head;
> + struct mbuf *m;
> int enq = 0;
>
> /* Reclaim transmitted frames. */
> @@ -1377,23 +1367,19 @@ alc_start(struct ifnet *ifp)
> return;
>
> for (;;) {
> - IFQ_DEQUEUE(&ifp->if_snd, m_head);
> - if (m_head == NULL)
> + if (sc->alc_cdata.alc_tx_cnt + ALC_MAXTXSEGS >=
> + ALC_TX_RING_CNT - 3) {
> + ifp->if_flags |= IFF_OACTIVE;
> break;
> + }
>
> - /*
> - * Pack the data into the transmit ring. If we
> - * don't have room, set the OACTIVE flag and wait
> - * for the NIC to drain the ring.
> - */
> - if (alc_encap(sc, &m_head)) {
> - if (m_head == NULL)
> - ifp->if_oerrors++;
> - else {
> - IF_PREPEND(&ifp->if_snd, m_head);
> - ifp->if_flags |= IFF_OACTIVE;
> - }
> + IFQ_DEQUEUE(&ifp->if_snd, m);
> + if (m == NULL)
> break;
> +
> + if (alc_encap(sc, m) != 0) {
> + ifp->if_oerrors++;
> + continue;
> }
> enq++;
>
> @@ -1403,7 +1389,7 @@ alc_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
> }
>
> Index: if_ale.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/pci/if_ale.c,v
> retrieving revision 1.40
> diff -u -p -r1.40 if_ale.c
> --- if_ale.c 25 Oct 2015 13:04:28 -0000 1.40
> +++ if_ale.c 6 Nov 2015 11:27:04 -0000
> @@ -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 m
> 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 m
> 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
> }
>
> Index: if_jme.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/pci/if_jme.c,v
> retrieving revision 1.42
> diff -u -p -r1.42 if_jme.c
> --- if_jme.c 25 Oct 2015 13:04:28 -0000 1.42
> +++ if_jme.c 6 Nov 2015 11:27:04 -0000
> @@ -100,7 +100,7 @@ int jme_init_rx_ring(struct jme_softc *)
> void jme_init_tx_ring(struct jme_softc *);
> void jme_init_ssb(struct jme_softc *);
> int jme_newbuf(struct jme_softc *, struct jme_rxdesc *);
> -int jme_encap(struct jme_softc *, struct mbuf **);
> +int jme_encap(struct jme_softc *, struct mbuf *);
> void jme_rxpkt(struct jme_softc *);
>
> void jme_tick(void *);
> @@ -1108,11 +1108,10 @@ jme_setwol(struct jme_softc *sc)
> #endif
>
> int
> -jme_encap(struct jme_softc *sc, struct mbuf **m_head)
> +jme_encap(struct jme_softc *sc, struct mbuf *m)
> {
> struct jme_txdesc *txd;
> struct jme_desc *desc;
> - struct mbuf *m;
> int error, i, prod;
> uint32_t cflags;
>
> @@ -1120,32 +1119,20 @@ jme_encap(struct jme_softc *sc, struct m
> txd = &sc->jme_cdata.jme_txdesc[prod];
>
> error = bus_dmamap_load_mbuf(sc->sc_dmat, txd->tx_dmamap,
> - *m_head, BUS_DMA_NOWAIT);
> + 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, txd->tx_dmamap,
> - *m_head, BUS_DMA_NOWAIT);
> + m, BUS_DMA_NOWAIT);
> if (error != 0)
> goto drop;
> }
>
> - /*
> - * Check descriptor overrun. Leave one free descriptor.
> - * Since we always use 64bit address mode for transmitting,
> - * each Tx request requires one more dummy descriptor.
> - */
> - if (sc->jme_cdata.jme_tx_cnt + txd->tx_dmamap->dm_nsegs + JME_TXD_RSVD >
> - JME_TX_RING_CNT - JME_TXD_RSVD) {
> - bus_dmamap_unload(sc->sc_dmat, txd->tx_dmamap);
> - return (ENOBUFS);
> - }
> -
> - m = *m_head;
> cflags = 0;
>
> /* Configure checksum offload. */
> @@ -1204,8 +1191,7 @@ jme_encap(struct jme_softc *sc, struct m
> return (0);
>
> drop:
> - m_freem(*m_head);
> - *m_head = NULL;
> + m_freem(m);
> return (error);
> }
>
> @@ -1213,7 +1199,7 @@ void
> jme_start(struct ifnet *ifp)
> {
> struct jme_softc *sc = ifp->if_softc;
> - struct mbuf *m_head;
> + struct mbuf *m;
> int enq = 0;
>
> /* Reclaim transmitted frames. */
> @@ -1238,8 +1224,8 @@ jme_start(struct ifnet *ifp)
> break;
> }
>
> - IFQ_DEQUEUE(&ifp->if_snd, m_head);
> - if (m_head == NULL)
> + IFQ_DEQUEUE(&ifp->if_snd, m);
> + if (m == NULL)
> break;
>
> /*
> @@ -1247,14 +1233,9 @@ jme_start(struct ifnet *ifp)
> * don't have room, set the OACTIVE flag and wait
> * for the NIC to drain the ring.
> */
> - if (jme_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 (jme_encap(sc, m) != 0) {
> + ifp->if_oerrors++;
> + continue;
> }
>
> enq++;
> @@ -1265,7 +1246,7 @@ jme_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
> }
>
> Index: if_vr.c
> ===================================================================
> RCS file: /cvs/src/sys/dev/pci/if_vr.c,v
> retrieving revision 1.144
> diff -u -p -r1.144 if_vr.c
> --- if_vr.c 25 Oct 2015 13:04:28 -0000 1.144
> +++ if_vr.c 6 Nov 2015 11:27:05 -0000
> @@ -1185,62 +1185,51 @@ vr_intr(void *arg)
> * pointers to the fragment pointers.
> */
> int
> -vr_encap(struct vr_softc *sc, struct vr_chain **cp, struct mbuf *m_head)
> +vr_encap(struct vr_softc *sc, struct vr_chain **cp, struct mbuf *m)
> {
> struct vr_chain *c = *cp;
> struct vr_desc *f = NULL;
> - struct mbuf *m_new = NULL;
> u_int32_t vr_ctl = 0, vr_status = 0, intdisable = 0;
> bus_dmamap_t txmap;
> int i, runt = 0;
> + int error;
>
> if (sc->vr_quirks & VR_Q_CSUM) {
> - if (m_head->m_pkthdr.csum_flags & M_IPV4_CSUM_OUT)
> + if (m->m_pkthdr.csum_flags & M_IPV4_CSUM_OUT)
> vr_ctl |= VR_TXCTL_IPCSUM;
> - if (m_head->m_pkthdr.csum_flags & M_TCP_CSUM_OUT)
> + if (m->m_pkthdr.csum_flags & M_TCP_CSUM_OUT)
> vr_ctl |= VR_TXCTL_TCPCSUM;
> - if (m_head->m_pkthdr.csum_flags & M_UDP_CSUM_OUT)
> + if (m->m_pkthdr.csum_flags & M_UDP_CSUM_OUT)
> vr_ctl |= VR_TXCTL_UDPCSUM;
> }
>
> - /* Deep copy for chips that need alignment, or too many segments */
> - if (sc->vr_quirks & VR_Q_NEEDALIGN ||
> - bus_dmamap_load_mbuf(sc->sc_dmat, c->vr_map, m_head,
> - BUS_DMA_NOWAIT | BUS_DMA_WRITE)) {
> - MGETHDR(m_new, M_DONTWAIT, MT_DATA);
> - if (m_new == NULL)
> - return (1);
> - if (m_head->m_pkthdr.len > MHLEN) {
> - MCLGET(m_new, M_DONTWAIT);
> - if (!(m_new->m_flags & M_EXT)) {
> - m_freem(m_new);
> - return (1);
> - }
> - }
> - m_copydata(m_head, 0, m_head->m_pkthdr.len,
> - mtod(m_new, caddr_t));
> - m_new->m_pkthdr.len = m_new->m_len = m_head->m_pkthdr.len;
> -
> - if (bus_dmamap_load_mbuf(sc->sc_dmat, c->vr_map, m_new,
> - BUS_DMA_NOWAIT | BUS_DMA_WRITE)) {
> - m_freem(m_new);
> - return(1);
> - }
> - }
> + if (sc->vr_quirks & VR_Q_NEEDALIGN) {
> + /* Deep copy for chips that need alignment */
> + error = EFBIG;
> + } else {
> + error = bus_dmamap_load_mbuf(sc->sc_dmat, c->vr_map, m,
> + BUS_DMA_NOWAIT | BUS_DMA_WRITE);
> + }
> +
> + switch (error) {
> + case 0:
> + break;
> + case EFBIG:
> + if (m_defrag(m, M_DONTWAIT) == 0 &&
> + bus_dmamap_load_mbuf(sc->sc_dmat, c->vr_map, m,
> + BUS_DMA_NOWAIT) == 0)
> + break;
> +
> + /* FALLTHROUGH */
> + default:
> + return (ENOBUFS);
> + }
>
> bus_dmamap_sync(sc->sc_dmat, c->vr_map, 0, c->vr_map->dm_mapsize,
> BUS_DMASYNC_PREWRITE);
> if (c->vr_map->dm_mapsize < VR_MIN_FRAMELEN)
> runt = 1;
>
> - /* Check number of available descriptors */
> - if (sc->vr_cdata.vr_tx_cnt + c->vr_map->dm_nsegs + runt >=
> - (VR_TX_LIST_CNT - 1)) {
> - if (m_new)
> - m_freem(m_new);
> - return(1);
> - }
> -
> #if NVLAN > 0
> /*
> * Tell chip to insert VLAN tag if needed.
> @@ -1248,8 +1237,8 @@ vr_encap(struct vr_softc *sc, struct vr_
> * in only 15 bits without the gap at 0x1000 (reserved for DEI).
> * Therefore we need to de- / re-construct the VLAN header.
> */
> - if (m_head->m_flags & M_VLANTAG) {
> - u_int32_t vtag = m_head->m_pkthdr.ether_vtag;
> + if (m->m_flags & M_VLANTAG) {
> + u_int32_t vtag = m->m_pkthdr.ether_vtag;
> vtag = EVL_VLANOFTAG(vtag) | EVL_PRIOFTAG(vtag) << 12;
> vr_status |= vtag << VR_TXSTAT_PQSHIFT;
> vr_ctl |= htole32(VR_TXCTL_INSERTTAG);
> @@ -1268,12 +1257,7 @@ vr_encap(struct vr_softc *sc, struct vr_
> sc->vr_quirks & VR_Q_INTDISABLE)
> intdisable = VR_TXNEXT_INTDISABLE;
>
> - if (m_new != NULL) {
> - m_freem(m_head);
> -
> - c->vr_mbuf = m_new;
> - } else
> - c->vr_mbuf = m_head;
> + c->vr_mbuf = m;
> txmap = c->vr_map;
> for (i = 0; i < txmap->dm_nsegs; i++) {
> if (i != 0)
> @@ -1321,7 +1305,7 @@ void
> vr_start(struct ifnet *ifp)
> {
> struct vr_softc *sc;
> - struct mbuf *m_head;
> + struct mbuf *m;
> struct vr_chain *cur_tx, *head_tx;
> unsigned int queued = 0;
>
> @@ -1334,17 +1318,22 @@ vr_start(struct ifnet *ifp)
> return;
>
> cur_tx = sc->vr_cdata.vr_tx_prod;
> - while (cur_tx->vr_mbuf == NULL) {
> - IFQ_DEQUEUE(&ifp->if_snd, m_head);
> - if (m_head == NULL)
> + for (;;) {
> + if (sc->vr_cdata.vr_tx_cnt + VR_MAXFRAGS >=
> + VR_TX_LIST_CNT - 1) {
> + ifp->if_flags |= IFF_OACTIVE;
> + break;
> + }
> +
> + IFQ_DEQUEUE(&ifp->if_snd, m);
> + if (m== NULL)
> break;
>
> /* Pack the data into the descriptor. */
> head_tx = cur_tx;
> - if (vr_encap(sc, &cur_tx, m_head)) {
> - /* Rollback, send what we were able to encap. */
> - IF_PREPEND(&ifp->if_snd, m_head);
> - break;
> + if (vr_encap(sc, &cur_tx, m)) {
> + ifp->if_oerrors++;
> + continue;
> }
> queued++;
>
> @@ -1357,8 +1346,7 @@ vr_start(struct ifnet *ifp)
> * to him.
> */
> if (ifp->if_bpf)
> - bpf_mtap_ether(ifp->if_bpf, head_tx->vr_mbuf,
> - BPF_DIRECTION_OUT);
> + bpf_mtap_ether(ifp->if_bpf, m, BPF_DIRECTION_OUT);
> #endif
> cur_tx = cur_tx->vr_nextdesc;
> }
> @@ -1374,9 +1362,6 @@ vr_start(struct ifnet *ifp)
>
> /* Set a timeout in case the chip goes out to lunch. */
> ifp->if_timer = 5;
> -
> - if (cur_tx->vr_mbuf != NULL)
> - ifp->if_flags |= IFF_OACTIVE;
> }
> }
>
