tell the stack myx_start is mpsafe.

as per the stack commit, the driver changes are:

1. setting ifp->if_xflags = IFXF_MPSAFE
2. only calling if_start() instead of its own start routine
3. clearing IFF_RUNNING before calling if_start_barrier() on its way down
4. only using IFQ_DEQUEUE (not ifq_deq_begin/commit/rollback)

1 files changed, 9 insertions, 19 deletions

diff --git a/sys/dev/pci/if_myx.c b/sys/dev/pci/if_myx.c
index fef3993aeb7..f1c98245fbb 100644
--- a/sys/dev/pci/if_myx.c
+++ b/sys/dev/pci/if_myx.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: if_myx.c,v 1.89 2015/12/01 12:37:12 dlg Exp $	*/
+/*	$OpenBSD: if_myx.c,v 1.90 2015/12/03 12:45:56 dlg Exp $	*/
 
 /*
  * Copyright (c) 2007 Reyk Floeter <reyk@openbsd.org>
@@ -511,6 +511,7 @@ myx_attachhook(void *arg)
 
 	ifp->if_softc = sc;
 	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
+	ifp->if_xflags = IFXF_MPSAFE;
 	ifp->if_ioctl = myx_ioctl;
 	ifp->if_start = myx_start;
 	ifp->if_watchdog = myx_watchdog;
@@ -1360,8 +1361,9 @@ myx_down(struct myx_softc *sc)
 		printf("%s: failed to reset the device\n", DEVNAME(sc));
 	}
 
-	CLR(ifp->if_flags, IFF_RUNNING);
 	ifq_clr_oactive(&ifp->if_snd);
+	CLR(ifp->if_flags, IFF_RUNNING);
+	if_start_barrier(ifp);
 
 	for (ring = 0; ring < 2; ring++) {
 		struct myx_rx_ring *mrr = &sc->sc_rx_ring[ring];
@@ -1436,11 +1438,6 @@ myx_start(struct ifnet *ifp)
 	u_int				free, used;
 	u_int8_t			flags;
 
-	if (!ISSET(ifp->if_flags, IFF_RUNNING) ||
-	    ifq_is_oactive(&ifp->if_snd) ||
-	    IFQ_IS_EMPTY(&ifp->if_snd))
-		return;
-
 	idx = sc->sc_tx_ring_prod;
 
 	/* figure out space */
@@ -1588,11 +1585,10 @@ int
 myx_intr(void *arg)
 {
 	struct myx_softc	*sc = (struct myx_softc *)arg;
-	struct ifnet		*ifp = &sc->sc_ac.ac_if;
 	volatile struct myx_status *sts = sc->sc_sts;
 	enum myx_state		 state;
 	bus_dmamap_t		 map = sc->sc_sts_dma.mxm_map;
-	u_int32_t		 data, start;
+	u_int32_t		 data;
 	u_int8_t		 valid = 0;
 
 	state = sc->sc_state;
@@ -1638,15 +1634,12 @@ myx_intr(void *arg)
 	bus_space_write_raw_region_4(sc->sc_memt, sc->sc_memh,
 	    sc->sc_irqclaimoff + sizeof(data), &data, sizeof(data));
 
-	start = ifq_is_oactive(&ifp->if_snd);
-
 	if (sts->ms_statusupdated) {
 		if (state == MYX_S_DOWN &&
 		    sc->sc_linkdown != sts->ms_linkdown) {
 			sc->sc_state = MYX_S_OFF;
 			membar_producer();
 			wakeup(sts);
-			start = 0;
 		} else {
 			data = sts->ms_linkstate;
 			if (data != 0xffffffff) {
@@ -1660,13 +1653,6 @@ myx_intr(void *arg)
 	bus_dmamap_sync(sc->sc_dmat, map, 0, map->dm_mapsize,
 	    BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
 
-	if (start) {
-		KERNEL_LOCK();
-		ifq_clr_oactive(&ifp->if_snd);
-		myx_start(ifp);
-		KERNEL_UNLOCK();
-	}
-
 	return (1);
 }
 
@@ -1715,6 +1701,10 @@ myx_txeof(struct myx_softc *sc, u_int32_t done_count)
 
 	sc->sc_tx_ring_cons = idx;
 	sc->sc_tx_cons = cons;
+
+	ifq_clr_oactive(&ifp->if_snd);
+	if (!ifq_empty(&ifp->if_snd))
+		if_start(ifp);
 }
 
 void