Convert to ifq_dequeue and perform m_defrag if the mbuf doesn't fit

With suggestions from and OK dlg

diff --git a/sys/dev/pci/if_xge.c b/sys/dev/pci/if_xge.c
index 564e40d..d550e8e 100644 (file)
--- a/sys/dev/pci/if_xge.c
+++ b/sys/dev/pci/if_xge.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_xge.c,v 1.75 2017/01/22 10:17:39 dlg Exp $ */
+/*     $OpenBSD: if_xge.c,v 1.76 2017/06/09 14:34:10 mikeb Exp $       */
 /*     $NetBSD: if_xge.c,v 1.1 2005/09/09 10:30:27 ragge Exp $ */
 
 /*
@@ -1116,33 +1116,38 @@ xge_start(struct ifnet *ifp)
        bus_dmamap_t dmp;
        struct  mbuf *m;
        uint64_t par, lcr;
-       int nexttx = 0, ntxd, error, i;
+       int nexttx = 0, ntxd, i;
 
        if (!(ifp->if_flags & IFF_RUNNING) || ifq_is_oactive(&ifp->if_snd))
                return;
 
        par = lcr = 0;
        for (;;) {
-               m = ifq_deq_begin(&ifp->if_snd);
-               if (m == NULL)
-                       break;  /* out of packets */
-
                if (sc->sc_nexttx == sc->sc_lasttx) {
-                       ifq_deq_rollback(&ifp->if_snd, m);
+                       ifq_set_oactive(&ifp->if_snd);
                        break;  /* No more space */
                }
 
+               m = ifq_dequeue(&ifp->if_snd);
+               if (m == NULL)
+                       break;  /* out of packets */
+
                nexttx = sc->sc_nexttx;
                dmp = sc->sc_txm[nexttx];
 
-               if ((error = bus_dmamap_load_mbuf(sc->sc_dmat, dmp, m,
-                   BUS_DMA_WRITE|BUS_DMA_NOWAIT)) != 0) {
-                       ifq_deq_rollback(&ifp->if_snd, m);
-                       printf("%s: bus_dmamap_load_mbuf error %d\n",
-                           XNAME, error);
+               switch (bus_dmamap_load_mbuf(sc->sc_dmat, dmp, m,
+                   BUS_DMA_WRITE|BUS_DMA_NOWAIT)) {
+               case 0:
                        break;
+               case EFBIG:
+                       if (m_defrag(m, M_DONTWAIT) == 0 &&
+                           bus_dmamap_load_mbuf(sc->sc_dmat, dmp, m,
+                           BUS_DMA_WRITE|BUS_DMA_NOWAIT) == 0)
+                               break;
+               default:
+                       m_freem(m);
+                       continue;
                }
-               ifq_deq_commit(&ifp->if_snd, m);
 
                bus_dmamap_sync(sc->sc_dmat, dmp, 0, dmp->dm_mapsize,
                    BUS_DMASYNC_PREWRITE);