rearrange txeof so it processes slots up to the index given in the

completion event, and only request completion events for the last packet
we place on the ring in bnxt_start, which doesn't do anything now but
will make tx faster when we get tx mitigation working.

diff --git a/sys/dev/pci/if_bnxt.c b/sys/dev/pci/if_bnxt.c
index 3920c8b..ecf090d 100644 (file)
--- a/sys/dev/pci/if_bnxt.c
+++ b/sys/dev/pci/if_bnxt.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: if_bnxt.c,v 1.5 2018/08/23 00:22:53 jmatthew Exp $    */
+/*     $OpenBSD: if_bnxt.c,v 1.6 2018/08/23 01:06:06 jmatthew Exp $    */
 /*-
  * Broadcom NetXtreme-C/E network driver.
  *
@@ -1036,7 +1036,7 @@ bnxt_start(struct ifqueue *ifq)
        struct bnxt_slot *bs;
        bus_dmamap_t map;
        struct mbuf *m;
-       u_int idx, free, used;
+       u_int idx, free, used, laststart;
        uint16_t txflags;
        int i;
 
@@ -1086,7 +1086,9 @@ bnxt_start(struct ifqueue *ifq)
                        txflags = TX_BD_SHORT_FLAGS_LHINT_GTE2K;
 
                txflags |= TX_BD_SHORT_TYPE_TX_BD_SHORT |
+                   TX_BD_SHORT_FLAGS_NO_CMPL |
                    (map->dm_nsegs << TX_BD_SHORT_FLAGS_BD_CNT_SFT);
+               laststart = idx;
 
                for (i = 0; i < map->dm_nsegs; i++) {
                        txring[idx].flags_type = htole16(txflags);
@@ -1110,6 +1112,12 @@ bnxt_start(struct ifqueue *ifq)
                        sc->sc_tx_prod = 0;
        }
 
+       /* unset NO_CMPL on the first bd of the last packet */
+       if (used != 0) {
+               txring[laststart].flags_type &=
+                   ~htole16(TX_BD_SHORT_FLAGS_NO_CMPL);
+       }
+
        bnxt_write_tx_doorbell(sc, &sc->sc_tx_ring, idx);
        sc->sc_tx_ring_prod = idx;
 }
@@ -1784,31 +1792,34 @@ bnxt_txeof(struct bnxt_softc *sc, struct cmpl_base *cmpl)
        struct tx_cmpl *txcmpl = (struct tx_cmpl *)cmpl;
        struct bnxt_slot *bs;
        bus_dmamap_t map;
-       u_int idx, freed;
+       u_int idx, freed, segs, last;
 
-       if (txcmpl->opaque != sc->sc_tx_cons)
-               printf("%s: txeof for %d, expected %d?\n",
-                   DEVNAME(sc), txcmpl->opaque, sc->sc_tx_cons);
        idx = sc->sc_tx_ring_cons;
+       last = sc->sc_tx_cons;
+       freed = 0;
+       do {
+               bs = &sc->sc_tx_slots[sc->sc_tx_cons];
+               map = bs->bs_map;
+
+               segs = map->dm_nsegs;
+               bus_dmamap_sync(sc->sc_dmat, map, 0, map->dm_mapsize,
+                   BUS_DMASYNC_POSTWRITE);
+               bus_dmamap_unload(sc->sc_dmat, map);
+               m_freem(bs->bs_m);
+               bs->bs_m = NULL;
 
-       bs = &sc->sc_tx_slots[sc->sc_tx_cons];
-       map = bs->bs_map;
+               idx += segs;
+               freed += segs;
+               if (idx >= sc->sc_tx_ring.ring_size)
+                       idx -= sc->sc_tx_ring.ring_size;
 
-       freed = map->dm_nsegs;
-       bus_dmamap_sync(sc->sc_dmat, map, 0, map->dm_mapsize,
-           BUS_DMASYNC_POSTWRITE);
-       bus_dmamap_unload(sc->sc_dmat, map);
-       m_freem(bs->bs_m);
-       bs->bs_m = NULL;
+               last = sc->sc_tx_cons;
+               if (++sc->sc_tx_cons >= sc->sc_tx_ring.ring_size)
+                       sc->sc_tx_cons = 0;
 
-       idx += freed;
-       if (idx >= sc->sc_tx_ring.ring_size)
-               idx -= sc->sc_tx_ring.ring_size;
+       } while (last != txcmpl->opaque);
        sc->sc_tx_ring_cons = idx;
 
-       if (++sc->sc_tx_cons >= sc->sc_tx_ring.ring_size)
-               sc->sc_tx_cons = 0;
-
        return (freed);
 }