[src/trunk]: src/sys/dev/pci Don't write to read-only VIRTIO_NET_S_LINK_UP bit

[ozaki-r <ozaki-r%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/729b1a596597
branches:  trunk
changeset: 822612:729b1a596597
user:      ozaki-r <ozaki-r%NetBSD.org@localhost>
date:      Tue Mar 28 04:09:52 2017 +0000

description:
Don't write to read-only VIRTIO_NET_S_LINK_UP bit

The bit is defined as read-only in the Virtio PCI Card Specification.
The fix is inspired by FreeBSD.

PR kern/52103 by s-yamaguchi@IIJ

diffstat:

 sys/dev/pci/if_vioif.c |  44 +++++++++++++++++---------------------------
 1 files changed, 17 insertions(+), 27 deletions(-)

diffs (103 lines):

diff -r 92e85e07c198 -r 729b1a596597 sys/dev/pci/if_vioif.c
--- a/sys/dev/pci/if_vioif.c    Tue Mar 28 03:19:20 2017 +0000
+++ b/sys/dev/pci/if_vioif.c    Tue Mar 28 04:09:52 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_vioif.c,v 1.32 2017/03/25 18:02:06 jdolecek Exp $   */
+/*     $NetBSD: if_vioif.c,v 1.33 2017/03/28 04:09:52 ozaki-r Exp $    */
 
 /*
  * Copyright (c) 2010 Minoura Makoto.
@@ -26,7 +26,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_vioif.c,v 1.32 2017/03/25 18:02:06 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_vioif.c,v 1.33 2017/03/28 04:09:52 ozaki-r Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_net_mpsafe.h"
@@ -269,7 +269,6 @@
 static void    vioif_tx_drain(struct vioif_softc *);
 
 /* other control */
-static int     vioif_updown(struct vioif_softc *, bool);
 static int     vioif_ctrl_rx(struct vioif_softc *, int, bool);
 static int     vioif_set_promisc(struct vioif_softc *, bool);
 static int     vioif_set_allmulti(struct vioif_softc *, bool);
@@ -719,9 +718,18 @@
 vioif_init(struct ifnet *ifp)
 {
        struct vioif_softc *sc = ifp->if_softc;
+       struct virtio_softc *vsc = sc->sc_virtio;
 
        vioif_stop(ifp, 0);
 
+       virtio_reinit_start(vsc);
+       virtio_negotiate_features(vsc, virtio_features(vsc));
+       virtio_start_vq_intr(vsc, &sc->sc_vq[VQ_RX]);
+       virtio_stop_vq_intr(vsc, &sc->sc_vq[VQ_TX]);
+       if (sc->sc_has_ctrl)
+               virtio_start_vq_intr(vsc, &sc->sc_vq[VQ_CTRL]);
+       virtio_reinit_end(vsc);
+
        if (!sc->sc_deferred_init_done) {
                sc->sc_deferred_init_done = 1;
                if (sc->sc_has_ctrl)
@@ -733,7 +741,6 @@
 
        vioif_populate_rx_mbufs(sc);
 
-       vioif_updown(sc, true);
        ifp->if_flags |= IFF_RUNNING;
        ifp->if_flags &= ~IFF_OACTIVE;
        vioif_rx_filter(sc);
@@ -754,6 +761,12 @@
        VIOIF_RX_UNLOCK(sc);
        VIOIF_TX_UNLOCK(sc);
 
+       /* disable interrupts */
+       virtio_stop_vq_intr(vsc, &sc->sc_vq[VQ_RX]);
+       virtio_stop_vq_intr(vsc, &sc->sc_vq[VQ_TX]);
+       if (sc->sc_has_ctrl)
+               virtio_stop_vq_intr(vsc, &sc->sc_vq[VQ_CTRL]);
+
        /* only way to stop I/O and DMA is resetting... */
        virtio_reset(vsc);
        vioif_rx_deq(sc);
@@ -762,15 +775,6 @@
 
        if (disable)
                vioif_rx_drain(sc);
-
-       virtio_reinit_start(vsc);
-       virtio_negotiate_features(vsc, virtio_features(vsc));
-       virtio_start_vq_intr(vsc, &sc->sc_vq[VQ_RX]);
-       virtio_stop_vq_intr(vsc, &sc->sc_vq[VQ_TX]);
-       if (sc->sc_has_ctrl)
-               virtio_start_vq_intr(vsc, &sc->sc_vq[VQ_CTRL]);
-       virtio_reinit_end(vsc);
-       vioif_updown(sc, false);
 }
 
 static void
@@ -1499,20 +1503,6 @@
        return r;
 }
 
-/* change link status */
-static int
-vioif_updown(struct vioif_softc *sc, bool isup)
-{
-       struct virtio_softc *vsc = sc->sc_virtio;
-
-       if (!(virtio_features(vsc) & VIRTIO_NET_F_STATUS))
-               return ENODEV;
-       virtio_write_device_config_1(vsc,
-                                    VIRTIO_NET_CONFIG_STATUS,
-                                    isup?VIRTIO_NET_S_LINK_UP:0);
-       return 0;
-}
-
 MODULE(MODULE_CLASS_DRIVER, if_vioif, "virtio");
  
 #ifdef _MODULE