[src/trunk]: src/sys/dev/pci vioif(4): divide interrupt handler for receiving

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

details:   https://anonhg.NetBSD.org/src/rev/e0cb71a52af4
branches:  trunk
changeset: 373961:e0cb71a52af4
user:      yamaguchi <yamaguchi%NetBSD.org@localhost>
date:      Thu Mar 23 01:58:04 2023 +0000

description:
vioif(4): divide interrupt handler for receiving
into dequeuing and preparing of buffers

diffstat:

 sys/dev/pci/if_vioif.c |  43 +++++++++++++++++++++++--------------------
 1 files changed, 23 insertions(+), 20 deletions(-)

diffs (121 lines):

diff -r 54077216033e -r e0cb71a52af4 sys/dev/pci/if_vioif.c
--- a/sys/dev/pci/if_vioif.c    Thu Mar 23 01:52:42 2023 +0000
+++ b/sys/dev/pci/if_vioif.c    Thu Mar 23 01:58:04 2023 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: if_vioif.c,v 1.91 2023/03/23 01:52:42 yamaguchi Exp $  */
+/*     $NetBSD: if_vioif.c,v 1.92 2023/03/23 01:58:04 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 1.91 2023/03/23 01:52:42 yamaguchi Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_vioif.c,v 1.92 2023/03/23 01:58:04 yamaguchi Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_net_mpsafe.h"
@@ -376,7 +376,7 @@
                    struct vioif_rxqueue *);
 static void    vioif_rx_queue_clear(struct vioif_rxqueue *);
 static bool    vioif_rx_deq_locked(struct vioif_softc *, struct virtio_softc *,
-                   struct vioif_rxqueue *, u_int);
+                   struct vioif_rxqueue *, u_int, size_t *);
 static int     vioif_rx_intr(void *);
 static void    vioif_rx_handle(void *);
 static void    vioif_rx_sched_handle(struct vioif_softc *,
@@ -1528,9 +1528,6 @@
 
        KASSERT(mutex_owned(rxq->rxq_lock));
 
-       if (rxq->rxq_stopping)
-               return;
-
        for (i = 0; i < vq->vq_num; i++) {
                int slot;
                r = virtio_enqueue_prep(vsc, vq, &slot);
@@ -1600,11 +1597,9 @@
        u_int limit = UINT_MAX;
        bool more;
 
-       KASSERT(rxq->rxq_stopping);
-
        mutex_enter(rxq->rxq_lock);
        for (;;) {
-               more = vioif_rx_deq_locked(sc, vsc, rxq, limit);
+               more = vioif_rx_deq_locked(sc, vsc, rxq, limit, NULL);
                if (more == false)
                        break;
        }
@@ -1614,21 +1609,25 @@
 /* dequeue received packets */
 static bool
 vioif_rx_deq_locked(struct vioif_softc *sc, struct virtio_softc *vsc,
-    struct vioif_rxqueue *rxq, u_int limit)
+    struct vioif_rxqueue *rxq, u_int limit, size_t *ndeqp)
 {
        struct virtqueue *vq = rxq->rxq_vq;
        struct ifnet *ifp = &sc->sc_ethercom.ec_if;
        struct mbuf *m;
        int slot, len;
-       bool more = false, dequeued = false;
+       bool more;
+       size_t ndeq;
 
        KASSERT(mutex_owned(rxq->rxq_lock));
 
+       more = false;
+       ndeq = 0;
+
        if (virtio_vq_is_enqueued(vsc, vq) == false)
-               return false;
-
-       for (;;) {
-               if (limit-- == 0) {
+               goto done;
+
+       for (;;ndeq++) {
+               if (ndeq >= limit) {
                        more = true;
                        break;
                }
@@ -1636,8 +1635,6 @@
                if (virtio_dequeue(vsc, vq, &slot, &len) != 0)
                        break;
 
-               dequeued = true;
-
                len -= sc->sc_hdr_size;
                bus_dmamap_sync(virtio_dmat(vsc), rxq->rxq_hdr_dmamaps[slot],
                    0, sc->sc_hdr_size, BUS_DMASYNC_POSTREAD);
@@ -1654,8 +1651,10 @@
                if_percpuq_enqueue(ifp->if_percpuq, m);
        }
 
-       if (dequeued)
-               vioif_populate_rx_mbufs_locked(sc, rxq);
+
+done:
+       if (ndeqp != NULL)
+               *ndeqp = ndeq;
 
        return more;
 }
@@ -1671,11 +1670,15 @@
        struct vioif_softc *sc = device_private(virtio_child(vsc));
        bool more;
        int enqueued;
+       size_t ndeq;
 
        KASSERT(mutex_owned(rxq->rxq_lock));
        KASSERT(!rxq->rxq_stopping);
 
-       more = vioif_rx_deq_locked(sc, vsc, rxq, limit);
+       more = vioif_rx_deq_locked(sc, vsc, rxq, limit, &ndeq);
+       if (ndeq > 0)
+               vioif_populate_rx_mbufs_locked(sc, rxq);
+
        if (more) {
                vioif_rx_sched_handle(sc, rxq);
                return;