[src/trunk]: src/sys/dev/pci vioif(4): access to txq_active and rxq_active wi...

[yamaguchi <yamaguchi%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/e3b870ac1db1
branches:  trunk
changeset: 373953:e3b870ac1db1
user:      yamaguchi <yamaguchi%NetBSD.org@localhost>
date:      Thu Mar 23 01:26:29 2023 +0000

description:
vioif(4): access to txq_active and rxq_active with lock held

diffstat:

 sys/dev/pci/if_vioif.c |  66 +++++++++++++++++++++++++++----------------------
 1 files changed, 36 insertions(+), 30 deletions(-)

diffs (128 lines):

diff -r 5b4114fba8e3 -r e3b870ac1db1 sys/dev/pci/if_vioif.c
--- a/sys/dev/pci/if_vioif.c    Thu Mar 23 01:23:18 2023 +0000
+++ b/sys/dev/pci/if_vioif.c    Thu Mar 23 01:26:29 2023 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_vioif.c,v 1.83 2023/03/23 01:23:18 yamaguchi Exp $  */
+/*     $NetBSD: if_vioif.c,v 1.84 2023/03/23 01:26:29 yamaguchi Exp $  */
 
 /*
  * Copyright (c) 2020 The NetBSD Foundation, Inc.
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_vioif.c,v 1.83 2023/03/23 01:23:18 yamaguchi Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_vioif.c,v 1.84 2023/03/23 01:26:29 yamaguchi Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_net_mpsafe.h"
@@ -1662,6 +1662,7 @@
        struct vioif_softc *sc = device_private(virtio_child(vsc));
        bool more;
 
+       KASSERT(mutex_owned(rxq->rxq_lock));
        KASSERT(!rxq->rxq_stopping);
 
        more = vioif_rx_deq_locked(sc, vsc, rxq, limit);
@@ -1674,7 +1675,8 @@
                vioif_rx_sched_handle(sc, rxq);
                return;
        }
-       atomic_store_relaxed(&rxq->rxq_active, false);
+
+       rxq->rxq_active = false;
 }
 
 static int
@@ -1686,22 +1688,23 @@
        struct vioif_softc *sc = device_private(virtio_child(vsc));
        u_int limit;
 
-       limit = sc->sc_rx_intr_process_limit;
-
-       if (atomic_load_relaxed(&rxq->rxq_active) == true)
-               return 1;
 
        mutex_enter(rxq->rxq_lock);
 
-       if (!rxq->rxq_stopping) {
-               rxq->rxq_workqueue = sc->sc_txrx_workqueue_sysctl;
-
-               virtio_stop_vq_intr(vsc, vq);
-               atomic_store_relaxed(&rxq->rxq_active, true);
-
-               vioif_rx_handle_locked(rxq, limit);
-       }
-
+       /* rx handler is already running in softint/workqueue */
+       if (rxq->rxq_active)
+               goto done;
+
+       if (rxq->rxq_stopping)
+               goto done;
+
+       rxq->rxq_active = true;
+
+       limit = sc->sc_rx_intr_process_limit;
+       virtio_stop_vq_intr(vsc, vq);
+       vioif_rx_handle_locked(rxq, limit);
+
+done:
        mutex_exit(rxq->rxq_lock);
        return 1;
 }
@@ -1773,6 +1776,7 @@
        struct ifnet *ifp = &sc->sc_ethercom.ec_if;
        bool more;
 
+       KASSERT(mutex_owned(txq->txq_lock));
        KASSERT(!txq->txq_stopping);
 
        more = vioif_tx_deq_locked(sc, vsc, txq, limit);
@@ -1790,7 +1794,8 @@
                return;
        }
 
-       atomic_store_relaxed(&txq->txq_active, false);
+       txq->txq_active = false;
+
        /* for ALTQ */
        if (txq == &sc->sc_txq[0]) {
                if_schedule_deferred_start(ifp);
@@ -1811,22 +1816,23 @@
 
        limit = sc->sc_tx_intr_process_limit;
 
-       if (atomic_load_relaxed(&txq->txq_active) == true)
-               return 1;
-
        mutex_enter(txq->txq_lock);
 
-       if (!txq->txq_stopping) {
-               txq->txq_workqueue = sc->sc_txrx_workqueue_sysctl;
-
-               virtio_stop_vq_intr(vsc, vq);
-               atomic_store_relaxed(&txq->txq_active, true);
-
-               vioif_tx_handle_locked(txq, limit);
-       }
-
+       /* tx handler is already running in softint/workqueue */
+       if (txq->txq_active)
+               goto done;
+
+       if (txq->txq_stopping)
+               goto done;
+
+       txq->txq_active = true;
+
+       virtio_stop_vq_intr(vsc, vq);
+       txq->txq_workqueue = sc->sc_txrx_workqueue_sysctl;
+       vioif_tx_handle_locked(txq, limit);
+
+done:
        mutex_exit(txq->txq_lock);
-
        return 1;
 }