Module Name: src
Committed By: jdolecek
Date: Wed May 17 20:04:50 UTC 2017
Modified Files:
src/sys/dev/pci: if_vioif.c
Log Message:
simplify vioif_start() - remove the delivery attempts on failure and retries,
leave that for the dedicated thread
if dma map load fails, retry after m_defrag(), but continue processing
other queue items regardless
set interface queue length according to the length of virtio queue, so that
higher layer won't queue more than interface can manage to keep in flight
use the mutexes always, not just with NET_MPSAFE, so they continue
being exercised and hence working; they also enforce proper IPL level
inspired by discussion around PR kern/52211, thanks to Masanobu SAITOH
for the m_defrag() idea and code
To generate a diff of this commit:
cvs rdiff -u -r1.35 -r1.36 src/sys/dev/pci/if_vioif.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/pci/if_vioif.c
diff -u src/sys/dev/pci/if_vioif.c:1.35 src/sys/dev/pci/if_vioif.c:1.36
--- src/sys/dev/pci/if_vioif.c:1.35 Wed May 17 18:21:40 2017
+++ src/sys/dev/pci/if_vioif.c Wed May 17 20:04:50 2017
@@ -1,4 +1,4 @@
-/* $NetBSD: if_vioif.c,v 1.35 2017/05/17 18:21:40 jdolecek Exp $ */
+/* $NetBSD: if_vioif.c,v 1.36 2017/05/17 20:04:50 jdolecek Exp $ */
/*
* Copyright (c) 2010 Minoura Makoto.
@@ -26,7 +26,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: if_vioif.c,v 1.35 2017/05/17 18:21:40 jdolecek Exp $");
+__KERNEL_RCSID(0, "$NetBSD: if_vioif.c,v 1.36 2017/05/17 20:04:50 jdolecek Exp $");
#ifdef _KERNEL_OPT
#include "opt_net_mpsafe.h"
@@ -226,8 +226,8 @@ struct vioif_softc {
} sc_ctrl_inuse;
kcondvar_t sc_ctrl_wait;
kmutex_t sc_ctrl_wait_lock;
- kmutex_t *sc_tx_lock;
- kmutex_t *sc_rx_lock;
+ kmutex_t sc_tx_lock;
+ kmutex_t sc_rx_lock;
bool sc_stopping;
bool sc_has_ctrl;
@@ -235,12 +235,12 @@ struct vioif_softc {
#define VIRTIO_NET_TX_MAXNSEGS (16) /* XXX */
#define VIRTIO_NET_CTRL_MAC_MAXENTRIES (64) /* XXX */
-#define VIOIF_TX_LOCK(_sc) if ((_sc)->sc_tx_lock) mutex_enter((_sc)->sc_tx_lock)
-#define VIOIF_TX_UNLOCK(_sc) if ((_sc)->sc_tx_lock) mutex_exit((_sc)->sc_tx_lock)
-#define VIOIF_TX_LOCKED(_sc) (!(_sc)->sc_tx_lock || mutex_owned((_sc)->sc_tx_lock))
-#define VIOIF_RX_LOCK(_sc) if ((_sc)->sc_rx_lock) mutex_enter((_sc)->sc_rx_lock)
-#define VIOIF_RX_UNLOCK(_sc) if ((_sc)->sc_rx_lock) mutex_exit((_sc)->sc_rx_lock)
-#define VIOIF_RX_LOCKED(_sc) (!(_sc)->sc_rx_lock || mutex_owned((_sc)->sc_rx_lock))
+#define VIOIF_TX_LOCK(_sc) mutex_enter(&(_sc)->sc_tx_lock)
+#define VIOIF_TX_UNLOCK(_sc) mutex_exit(&(_sc)->sc_tx_lock)
+#define VIOIF_TX_LOCKED(_sc) mutex_owned(&(_sc)->sc_tx_lock)
+#define VIOIF_RX_LOCK(_sc) mutex_enter(&(_sc)->sc_rx_lock)
+#define VIOIF_RX_UNLOCK(_sc) mutex_exit(&(_sc)->sc_rx_lock)
+#define VIOIF_RX_LOCKED(_sc) mutex_owned(&(_sc)->sc_rx_lock)
/* cfattach interface functions */
static int vioif_match(device_t, cfdata_t, void *);
@@ -439,7 +439,7 @@ vioif_alloc_mems(struct vioif_softc *sc)
C_L1(txhdr_dmamaps[i], tx_hdrs[i],
sizeof(struct virtio_net_hdr), 1,
WRITE, "tx header");
- C(tx_dmamaps[i], NULL, ETHER_MAX_LEN, 16 /* XXX */, 0,
+ C(tx_dmamaps[i], NULL, ETHER_MAX_LEN, VIRTIO_NET_TX_MAXNSEGS, 0,
"tx payload");
}
@@ -592,13 +592,8 @@ vioif_attach(device_t parent, device_t s
aprint_normal_dev(self, "Ethernet address %s\n", ether_sprintf(sc->sc_mac));
-#ifdef VIOIF_MPSAFE
- sc->sc_tx_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NET);
- sc->sc_rx_lock = mutex_obj_alloc(MUTEX_DEFAULT, IPL_NET);
-#else
- sc->sc_tx_lock = NULL;
- sc->sc_rx_lock = NULL;
-#endif
+ mutex_init(&sc->sc_tx_lock, MUTEX_DEFAULT, IPL_NET);
+ mutex_init(&sc->sc_rx_lock, MUTEX_DEFAULT, IPL_NET);
sc->sc_stopping = false;
/*
@@ -680,6 +675,8 @@ skip:
ifp->if_stop = vioif_stop;
ifp->if_capabilities = 0;
ifp->if_watchdog = vioif_watchdog;
+ IFQ_SET_MAXLEN(&ifp->if_snd, MAX(sc->sc_vq[VQ_TX].vq_num, IFQ_MAXLEN));
+ IFQ_SET_READY(&ifp->if_snd);
sc->sc_ethercom.ec_capabilities |= ETHERCAP_VLAN_MTU;
@@ -690,10 +687,8 @@ skip:
return;
err:
- if (sc->sc_tx_lock)
- mutex_obj_free(sc->sc_tx_lock);
- if (sc->sc_rx_lock)
- mutex_obj_free(sc->sc_rx_lock);
+ mutex_destroy(&sc->sc_tx_lock);
+ mutex_destroy(&sc->sc_rx_lock);
if (sc->sc_has_ctrl) {
cv_destroy(&sc->sc_ctrl_wait);
@@ -799,7 +794,7 @@ vioif_start(struct ifnet *ifp)
struct virtio_softc *vsc = sc->sc_virtio;
struct virtqueue *vq = &sc->sc_vq[VQ_TX];
struct mbuf *m;
- int queued = 0, retry = 0;
+ int queued = 0;
VIOIF_TX_LOCK(sc);
@@ -814,41 +809,58 @@ vioif_start(struct ifnet *ifp)
int slot, r;
IFQ_DEQUEUE(&ifp->if_snd, m);
-
if (m == NULL)
break;
-retry:
r = virtio_enqueue_prep(vsc, vq, &slot);
if (r == EAGAIN) {
ifp->if_flags |= IFF_OACTIVE;
- vioif_tx_vq_done_locked(vq);
- if (retry++ == 0)
- goto retry;
- else
- break;
+ m_freem(m);
+ break;
}
if (r != 0)
panic("enqueue_prep for a tx buffer");
+
r = bus_dmamap_load_mbuf(virtio_dmat(vsc),
sc->sc_tx_dmamaps[slot],
m, BUS_DMA_WRITE|BUS_DMA_NOWAIT);
if (r != 0) {
- virtio_enqueue_abort(vsc, vq, slot);
- aprint_error_dev(sc->sc_dev,
- "tx dmamap load failed, error code %d\n", r);
- break;
+ /* maybe just too fragmented */
+ struct mbuf *newm;
+
+ newm = m_defrag(m, M_NOWAIT);
+ if (newm == NULL) {
+ aprint_error_dev(sc->sc_dev,
+ "m_defrag() failed\n");
+ m_freem(m);
+ goto skip;
+ }
+
+ r = bus_dmamap_load_mbuf(virtio_dmat(vsc),
+ sc->sc_tx_dmamaps[slot],
+ newm, BUS_DMA_WRITE|BUS_DMA_NOWAIT);
+ if (r != 0) {
+ aprint_error_dev(sc->sc_dev,
+ "tx dmamap load failed, error code %d\n",
+ r);
+ m_freem(newm);
+skip:
+ virtio_enqueue_abort(vsc, vq, slot);
+ continue;
+ }
}
+
+ /* This should actually never fail */
r = virtio_enqueue_reserve(vsc, vq, slot,
sc->sc_tx_dmamaps[slot]->dm_nsegs + 1);
if (r != 0) {
+ aprint_error_dev(sc->sc_dev,
+ "virtio_enqueue_reserve failed, error code %d\n",
+ r);
bus_dmamap_unload(virtio_dmat(vsc),
sc->sc_tx_dmamaps[slot]);
- vioif_tx_vq_done_locked(vq);
- if (retry++ == 0)
- goto retry;
- else
- break;
+ /* slot already freed by virtio_enqueue_reserve */
+ continue;
}
sc->sc_tx_mbufs[slot] = m;
@@ -863,13 +875,11 @@ retry:
virtio_enqueue(vsc, vq, slot, sc->sc_txhdr_dmamaps[slot], true);
virtio_enqueue(vsc, vq, slot, sc->sc_tx_dmamaps[slot], true);
virtio_enqueue_commit(vsc, vq, slot, false);
+
queued++;
bpf_mtap(ifp, m);
}
- if (m != NULL)
- m_freem(m);
-
if (queued > 0) {
virtio_enqueue_commit(vsc, vq, -1, true);
ifp->if_timer = 5;
