From 058d3950c9aa2ddc80b20bf011d15f811782c19c Mon Sep 17 00:00:00 2001
From: jmatthew <jmatthew@openbsd.org>
Date: Thu, 23 Aug 2018 01:06:06 +0000
Subject: [PATCH] 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.

---
 sys/dev/pci/if_bnxt.c | 51 ++++++++++++++++++++++++++-----------------
 1 file changed, 31 insertions(+), 20 deletions(-)

diff --git a/sys/dev/pci/if_bnxt.c b/sys/dev/pci/if_bnxt.c
index 3920c8b23fa..ecf090d0bdc 100644
--- 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);
 }
 
-- 
2.20.1