git: 3dd5760aa5f8 - main - if_epair: rework
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Date: Tue, 02 Nov 2021 08:24:42 UTC
The branch main has been updated by kp:
URL: https://cgit.FreeBSD.org/src/commit/?id=3dd5760aa5f876f8a3f0735afeebdf9ee414e1f5
commit 3dd5760aa5f876f8a3f0735afeebdf9ee414e1f5
Author: Bjoern A. Zeeb <bz@FreeBSD.org>
AuthorDate: 2021-10-09 14:09:04 +0000
Commit: Kristof Provost <kp@FreeBSD.org>
CommitDate: 2021-11-02 08:23:46 +0000
if_epair: rework
Rework if_epair(4) to no longer use netisr and dpcpu.
Instead use mbufq and swi_net.
This simplifies the code and seems to make it work better and
no longer hang.
Work largely by bz@, with minor tweaks by kp@.
Reviewed by: bz, kp
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D31077
---
sys/net/if_epair.c | 746 +++++++++++++++++------------------------------------
1 file changed, 240 insertions(+), 506 deletions(-)
diff --git a/sys/net/if_epair.c b/sys/net/if_epair.c
index a62fbfad8771..e46c5271cc0f 100644
--- a/sys/net/if_epair.c
+++ b/sys/net/if_epair.c
@@ -2,8 +2,8 @@
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2008 The FreeBSD Foundation
- * Copyright (c) 2009-2010 Bjoern A. Zeeb <bz@FreeBSD.org>
* All rights reserved.
+ * Copyright (c) 2009-2021 Bjoern A. Zeeb <bz@FreeBSD.org>
*
* This software was developed by CK Software GmbH under sponsorship
* from the FreeBSD Foundation.
@@ -37,17 +37,6 @@
* This is mostly intended to be used to provide connectivity between
* different virtual network stack instances.
*/
-/*
- * Things to re-think once we have more experience:
- * - ifp->if_reassign function once we can test with vimage. Depending on
- * how if_vmove() is going to be improved.
- * - Real random etheraddrs that are checked to be uniquish; we would need
- * to re-do them in case we move the interface between network stacks
- * in a private if_reassign function.
- * In case we bridge to a real interface/network or between indepedent
- * epairs on multiple stacks/machines, we may need this.
- * For now let the user handle that case.
- */
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
@@ -61,13 +50,15 @@ __FBSDID("$FreeBSD$");
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/proc.h>
-#include <sys/refcount.h>
#include <sys/queue.h>
#include <sys/smp.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/types.h>
+#include <sys/buf_ring.h>
+#include <sys/bus.h>
+#include <sys/interrupt.h>
#include <net/bpf.h>
#include <net/ethernet.h>
@@ -80,122 +71,41 @@ __FBSDID("$FreeBSD$");
#include <net/netisr.h>
#include <net/vnet.h>
-SYSCTL_DECL(_net_link);
-static SYSCTL_NODE(_net_link, OID_AUTO, epair, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
- "epair sysctl");
-
-#ifdef EPAIR_DEBUG
-static int epair_debug = 0;
-SYSCTL_INT(_net_link_epair, OID_AUTO, epair_debug, CTLFLAG_RW,
- &epair_debug, 0, "if_epair(4) debugging.");
-#define DPRINTF(fmt, arg...) \
- if (epair_debug) \
- printf("[%s:%d] " fmt, __func__, __LINE__, ##arg)
-#else
-#define DPRINTF(fmt, arg...)
-#endif
-
-static void epair_nh_sintr(struct mbuf *);
-static struct mbuf *epair_nh_m2cpuid(struct mbuf *, uintptr_t, u_int *);
-static void epair_nh_drainedcpu(u_int);
-
-static void epair_start_locked(struct ifnet *);
-static int epair_media_change(struct ifnet *);
-static void epair_media_status(struct ifnet *, struct ifmediareq *);
-
static int epair_clone_match(struct if_clone *, const char *);
static int epair_clone_create(struct if_clone *, char *, size_t, caddr_t);
static int epair_clone_destroy(struct if_clone *, struct ifnet *);
static const char epairname[] = "epair";
-static unsigned int next_index = 0;
+#define RXRSIZE 4096 /* Probably overkill by 4-8x. */
-/* Netisr related definitions and sysctl. */
-static struct netisr_handler epair_nh = {
- .nh_name = epairname,
- .nh_proto = NETISR_EPAIR,
- .nh_policy = NETISR_POLICY_CPU,
- .nh_handler = epair_nh_sintr,
- .nh_m2cpuid = epair_nh_m2cpuid,
- .nh_drainedcpu = epair_nh_drainedcpu,
-};
+static MALLOC_DEFINE(M_EPAIR, epairname,
+ "Pair of virtual cross-over connected Ethernet-like interfaces");
-static int
-sysctl_epair_netisr_maxqlen(SYSCTL_HANDLER_ARGS)
-{
- int error, qlimit;
+VNET_DEFINE_STATIC(struct if_clone *, epair_cloner);
+#define V_epair_cloner VNET(epair_cloner)
- netisr_getqlimit(&epair_nh, &qlimit);
- error = sysctl_handle_int(oidp, &qlimit, 0, req);
- if (error || !req->newptr)
- return (error);
- if (qlimit < 1)
- return (EINVAL);
- return (netisr_setqlimit(&epair_nh, qlimit));
-}
-SYSCTL_PROC(_net_link_epair, OID_AUTO, netisr_maxqlen,
- CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0,
- sysctl_epair_netisr_maxqlen, "I",
- "Maximum if_epair(4) netisr \"hw\" queue length");
+static unsigned int next_index = 0;
+#define EPAIR_LOCK_INIT() mtx_init(&epair_n_index_mtx, "epairidx", \
+ NULL, MTX_DEF)
+#define EPAIR_LOCK_DESTROY() mtx_destroy(&epair_n_index_mtx)
+#define EPAIR_LOCK() mtx_lock(&epair_n_index_mtx)
+#define EPAIR_UNLOCK() mtx_unlock(&epair_n_index_mtx)
+
+static void *swi_cookie[MAXCPU]; /* swi(9). */
+static STAILQ_HEAD(, epair_softc) swi_sc[MAXCPU];
+static struct mtx epair_n_index_mtx;
struct epair_softc {
struct ifnet *ifp; /* This ifp. */
struct ifnet *oifp; /* other ifp of pair. */
+ void *swi_cookie; /* swi(9). */
+ struct buf_ring *rxring[2];
+ volatile int ridx; /* 0 || 1 */
struct ifmedia media; /* Media config (fake). */
- u_int refcount; /* # of mbufs in flight. */
- u_int cpuid; /* CPU ID assigned upon creation. */
- void (*if_qflush)(struct ifnet *);
- /* Original if_qflush routine. */
+ uint32_t cpuidx;
+ STAILQ_ENTRY(epair_softc) entry;
};
-/*
- * Per-CPU list of ifps with data in the ifq that needs to be flushed
- * to the netisr ``hw'' queue before we allow any further direct queuing
- * to the ``hw'' queue.
- */
-struct epair_ifp_drain {
- STAILQ_ENTRY(epair_ifp_drain) ifp_next;
- struct ifnet *ifp;
-};
-STAILQ_HEAD(eid_list, epair_ifp_drain);
-
-#define EPAIR_LOCK_INIT(dpcpu) mtx_init(&(dpcpu)->if_epair_mtx, \
- "if_epair", NULL, MTX_DEF)
-#define EPAIR_LOCK_DESTROY(dpcpu) mtx_destroy(&(dpcpu)->if_epair_mtx)
-#define EPAIR_LOCK_ASSERT(dpcpu) mtx_assert(&(dpcpu)->if_epair_mtx, \
- MA_OWNED)
-#define EPAIR_LOCK(dpcpu) mtx_lock(&(dpcpu)->if_epair_mtx)
-#define EPAIR_UNLOCK(dpcpu) mtx_unlock(&(dpcpu)->if_epair_mtx)
-
-#ifdef INVARIANTS
-#define EPAIR_REFCOUNT_INIT(r, v) refcount_init((r), (v))
-#define EPAIR_REFCOUNT_AQUIRE(r) refcount_acquire((r))
-#define EPAIR_REFCOUNT_RELEASE(r) refcount_release((r))
-#define EPAIR_REFCOUNT_ASSERT(a, p) KASSERT(a, p)
-#else
-#define EPAIR_REFCOUNT_INIT(r, v)
-#define EPAIR_REFCOUNT_AQUIRE(r)
-#define EPAIR_REFCOUNT_RELEASE(r)
-#define EPAIR_REFCOUNT_ASSERT(a, p)
-#endif
-
-static MALLOC_DEFINE(M_EPAIR, epairname,
- "Pair of virtual cross-over connected Ethernet-like interfaces");
-
-VNET_DEFINE_STATIC(struct if_clone *, epair_cloner);
-#define V_epair_cloner VNET(epair_cloner)
-
-/*
- * DPCPU area and functions.
- */
-struct epair_dpcpu {
- struct mtx if_epair_mtx; /* Per-CPU locking. */
- int epair_drv_flags; /* Per-CPU ``hw'' drv flags. */
- struct eid_list epair_ifp_drain_list; /* Per-CPU list of ifps with
- * data in the ifq. */
-};
-DPCPU_DEFINE(struct epair_dpcpu, epair_dpcpu);
-
static void
epair_clear_mbuf(struct mbuf *m)
{
@@ -210,313 +120,179 @@ epair_clear_mbuf(struct mbuf *m)
}
static void
-epair_dpcpu_init(void)
+epair_if_input(struct epair_softc *sc, int ridx)
{
- struct epair_dpcpu *epair_dpcpu;
- struct eid_list *s;
- u_int cpuid;
-
- CPU_FOREACH(cpuid) {
- epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
-
- /* Initialize per-cpu lock. */
- EPAIR_LOCK_INIT(epair_dpcpu);
-
- /* Driver flags are per-cpu as are our netisr "hw" queues. */
- epair_dpcpu->epair_drv_flags = 0;
-
- /*
- * Initialize per-cpu drain list.
- * Manually do what STAILQ_HEAD_INITIALIZER would do.
- */
- s = &epair_dpcpu->epair_ifp_drain_list;
- s->stqh_first = NULL;
- s->stqh_last = &s->stqh_first;
- }
-}
+ struct epoch_tracker et;
+ struct ifnet *ifp;
+ struct mbuf *m;
-static void
-epair_dpcpu_detach(void)
-{
- struct epair_dpcpu *epair_dpcpu;
- u_int cpuid;
+ ifp = sc->ifp;
+ NET_EPOCH_ENTER(et);
+ do {
+ m = buf_ring_dequeue_sc(sc->rxring[ridx]);
+ if (m == NULL)
+ break;
- CPU_FOREACH(cpuid) {
- epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
+ MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
+ (*ifp->if_input)(ifp, m);
- /* Destroy per-cpu lock. */
- EPAIR_LOCK_DESTROY(epair_dpcpu);
- }
+ } while (1);
+ NET_EPOCH_EXIT(et);
}
-/*
- * Helper functions.
- */
-static u_int
-cpuid_from_ifp(struct ifnet *ifp)
+static void
+epair_sintr(struct epair_softc *sc)
{
- struct epair_softc *sc;
+ int ridx, nidx;
- if (ifp == NULL)
- return (0);
- sc = ifp->if_softc;
+ if_ref(sc->ifp);
+ do {
+ ridx = sc->ridx;
+ nidx = (ridx == 0) ? 1 : 0;
+ } while (!atomic_cmpset_int(&sc->ridx, ridx, nidx));
+ epair_if_input(sc, ridx);
- return (sc->cpuid);
+ if_rele(sc->ifp);
}
-/*
- * Netisr handler functions.
- */
static void
-epair_nh_sintr(struct mbuf *m)
-{
- struct ifnet *ifp;
- struct epair_softc *sc __unused;
-
- ifp = m->m_pkthdr.rcvif;
- (*ifp->if_input)(ifp, m);
- sc = ifp->if_softc;
- EPAIR_REFCOUNT_RELEASE(&sc->refcount);
- EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
- ("%s: ifp=%p sc->refcount not >= 1: %d",
- __func__, ifp, sc->refcount));
- DPRINTF("ifp=%p refcount=%u\n", ifp, sc->refcount);
-}
-
-static struct mbuf *
-epair_nh_m2cpuid(struct mbuf *m, uintptr_t source, u_int *cpuid)
+epair_intr(void *arg)
{
+ struct epair_softc *sc;
+ uint32_t cpuidx;
+
+ cpuidx = (uintptr_t)arg;
+ /* If this is a problem, this is a read-mostly situation. */
+ EPAIR_LOCK();
+ STAILQ_FOREACH(sc, &swi_sc[cpuidx], entry) {
+ /* Do this lockless. */
+ if (buf_ring_empty(sc->rxring[sc->ridx]))
+ continue;
+ epair_sintr(sc);
+ }
+ EPAIR_UNLOCK();
- *cpuid = cpuid_from_ifp(m->m_pkthdr.rcvif);
-
- return (m);
+ return;
}
-static void
-epair_nh_drainedcpu(u_int cpuid)
+static int
+epair_menq(struct mbuf *m, struct epair_softc *osc)
{
- struct epair_dpcpu *epair_dpcpu;
- struct epair_ifp_drain *elm, *tvar;
- struct ifnet *ifp;
+ struct ifnet *ifp, *oifp;
+ int len, ret;
+ int ridx;
+ short mflags;
+ bool was_empty;
- epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
- EPAIR_LOCK(epair_dpcpu);
/*
- * Assume our "hw" queue and possibly ifq will be emptied
- * again. In case we will overflow the "hw" queue while
- * draining, epair_start_locked will set IFF_DRV_OACTIVE
- * again and we will stop and return.
+ * I know this looks weird. We pass the "other sc" as we need that one
+ * and can get both ifps from it as well.
*/
- STAILQ_FOREACH_SAFE(elm, &epair_dpcpu->epair_ifp_drain_list,
- ifp_next, tvar) {
- ifp = elm->ifp;
- epair_dpcpu->epair_drv_flags &= ~IFF_DRV_OACTIVE;
- ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
- epair_start_locked(ifp);
-
- IFQ_LOCK(&ifp->if_snd);
- if (IFQ_IS_EMPTY(&ifp->if_snd)) {
- struct epair_softc *sc __unused;
-
- STAILQ_REMOVE(&epair_dpcpu->epair_ifp_drain_list,
- elm, epair_ifp_drain, ifp_next);
- /* The cached ifp goes off the list. */
- sc = ifp->if_softc;
- EPAIR_REFCOUNT_RELEASE(&sc->refcount);
- EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
- ("%s: ifp=%p sc->refcount not >= 1: %d",
- __func__, ifp, sc->refcount));
- free(elm, M_EPAIR);
- }
- IFQ_UNLOCK(&ifp->if_snd);
+ oifp = osc->ifp;
+ ifp = osc->oifp;
- if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) != 0) {
- /* Our "hw"q overflew again. */
- epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
- DPRINTF("hw queue length overflow at %u\n",
- epair_nh.nh_qlimit);
- break;
- }
- }
- EPAIR_UNLOCK(epair_dpcpu);
-}
+ M_ASSERTPKTHDR(m);
+ epair_clear_mbuf(m);
+ if_setrcvif(m, oifp);
+ M_SETFIB(m, oifp->if_fib);
-/*
- * Network interface (`if') related functions.
- */
-static void
-epair_remove_ifp_from_draining(struct ifnet *ifp)
-{
- struct epair_dpcpu *epair_dpcpu;
- struct epair_ifp_drain *elm, *tvar;
- u_int cpuid;
-
- CPU_FOREACH(cpuid) {
- epair_dpcpu = DPCPU_ID_PTR(cpuid, epair_dpcpu);
- EPAIR_LOCK(epair_dpcpu);
- STAILQ_FOREACH_SAFE(elm, &epair_dpcpu->epair_ifp_drain_list,
- ifp_next, tvar) {
- if (ifp == elm->ifp) {
- struct epair_softc *sc __unused;
-
- STAILQ_REMOVE(
- &epair_dpcpu->epair_ifp_drain_list, elm,
- epair_ifp_drain, ifp_next);
- /* The cached ifp goes off the list. */
- sc = ifp->if_softc;
- EPAIR_REFCOUNT_RELEASE(&sc->refcount);
- EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
- ("%s: ifp=%p sc->refcount not >= 1: %d",
- __func__, ifp, sc->refcount));
- free(elm, M_EPAIR);
- }
- }
- EPAIR_UNLOCK(epair_dpcpu);
- }
-}
+ /* Save values as once the mbuf is queued, it's not ours anymore. */
+ len = m->m_pkthdr.len;
+ mflags = m->m_flags;
-static int
-epair_add_ifp_for_draining(struct ifnet *ifp)
-{
- struct epair_dpcpu *epair_dpcpu;
- struct epair_softc *sc;
- struct epair_ifp_drain *elm = NULL;
+ MPASS(m->m_nextpkt == NULL);
+ MPASS((m->m_pkthdr.csum_flags & CSUM_SND_TAG) == 0);
- sc = ifp->if_softc;
- epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
- EPAIR_LOCK_ASSERT(epair_dpcpu);
- STAILQ_FOREACH(elm, &epair_dpcpu->epair_ifp_drain_list, ifp_next)
- if (elm->ifp == ifp)
- break;
- /* If the ifp is there already, return success. */
- if (elm != NULL)
+ ridx = atomic_load_int(&osc->ridx);
+ was_empty = buf_ring_empty(osc->rxring[ridx]);
+ ret = buf_ring_enqueue(osc->rxring[ridx], m);
+ if (ret != 0) {
+ /* Ring is full. */
+ m_freem(m);
return (0);
+ }
- elm = malloc(sizeof(struct epair_ifp_drain), M_EPAIR, M_NOWAIT|M_ZERO);
- if (elm == NULL)
- return (ENOMEM);
+ if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
+ /*
+ * IFQ_HANDOFF_ADJ/ip_handoff() update statistics,
+ * but as we bypass all this we have to duplicate
+ * the logic another time.
+ */
+ if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
+ if (mflags & (M_BCAST|M_MCAST))
+ if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
+ /* Someone else received the packet. */
+ if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1);
- elm->ifp = ifp;
- /* Add a reference for the ifp pointer on the list. */
- EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
- STAILQ_INSERT_TAIL(&epair_dpcpu->epair_ifp_drain_list, elm, ifp_next);
+ /* Kick the interrupt handler for the first packet. */
+ if (was_empty && osc->swi_cookie != NULL)
+ swi_sched(osc->swi_cookie, 0);
return (0);
}
static void
-epair_start_locked(struct ifnet *ifp)
+epair_start(struct ifnet *ifp)
{
- struct epair_dpcpu *epair_dpcpu;
struct mbuf *m;
struct epair_softc *sc;
struct ifnet *oifp;
- int error;
-
- DPRINTF("ifp=%p\n", ifp);
- sc = ifp->if_softc;
- epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
- EPAIR_LOCK_ASSERT(epair_dpcpu);
-
- if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0)
- return;
- if ((ifp->if_flags & IFF_UP) == 0)
- return;
/*
* We get packets here from ether_output via if_handoff()
* and need to put them into the input queue of the oifp
- * and call oifp->if_input() via netisr/epair_sintr().
+ * and will put the packet into the receive-queue (rxq) of the
+ * other interface (oifp) of our pair.
*/
+ sc = ifp->if_softc;
oifp = sc->oifp;
sc = oifp->if_softc;
for (;;) {
IFQ_DEQUEUE(&ifp->if_snd, m);
if (m == NULL)
break;
+ M_ASSERTPKTHDR(m);
BPF_MTAP(ifp, m);
- /*
- * In case the outgoing interface is not usable,
- * drop the packet.
- */
- if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
- (oifp->if_flags & IFF_UP) ==0) {
- if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
+ /* In case either interface is not usable drop the packet. */
+ if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
+ (ifp->if_flags & IFF_UP) == 0 ||
+ (oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
+ (oifp->if_flags & IFF_UP) == 0) {
m_freem(m);
continue;
}
- DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname);
-
- epair_clear_mbuf(m);
-
- /*
- * Add a reference so the interface cannot go while the
- * packet is in transit as we rely on rcvif to stay valid.
- */
- EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
- m->m_pkthdr.rcvif = oifp;
- CURVNET_SET_QUIET(oifp->if_vnet);
- error = netisr_queue(NETISR_EPAIR, m);
- CURVNET_RESTORE();
- if (!error) {
- if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
- /* Someone else received the packet. */
- if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1);
- } else {
- /* The packet was freed already. */
- epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
- ifp->if_drv_flags |= IFF_DRV_OACTIVE;
- (void) epair_add_ifp_for_draining(ifp);
- if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
- EPAIR_REFCOUNT_RELEASE(&sc->refcount);
- EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
- ("%s: ifp=%p sc->refcount not >= 1: %d",
- __func__, oifp, sc->refcount));
- }
- }
-}
-static void
-epair_start(struct ifnet *ifp)
-{
- struct epair_dpcpu *epair_dpcpu;
-
- epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu);
- EPAIR_LOCK(epair_dpcpu);
- epair_start_locked(ifp);
- EPAIR_UNLOCK(epair_dpcpu);
+ (void) epair_menq(m, sc);
+ }
}
static int
-epair_transmit_locked(struct ifnet *ifp, struct mbuf *m)
+epair_transmit(struct ifnet *ifp, struct mbuf *m)
{
- struct epair_dpcpu *epair_dpcpu;
struct epair_softc *sc;
struct ifnet *oifp;
int error, len;
short mflags;
- DPRINTF("ifp=%p m=%p\n", ifp, m);
- sc = ifp->if_softc;
- epair_dpcpu = DPCPU_ID_PTR(sc->cpuid, epair_dpcpu);
- EPAIR_LOCK_ASSERT(epair_dpcpu);
-
if (m == NULL)
return (0);
+ M_ASSERTPKTHDR(m);
/*
* We are not going to use the interface en/dequeue mechanism
* on the TX side. We are called from ether_output_frame()
- * and will put the packet into the incoming queue of the
- * other interface of our pair via the netsir.
+ * and will put the packet into the receive-queue (rxq) of the
+ * other interface (oifp) of our pair.
*/
if ((ifp->if_drv_flags & IFF_DRV_RUNNING) == 0) {
m_freem(m);
+ if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
return (ENXIO);
}
if ((ifp->if_flags & IFF_UP) == 0) {
m_freem(m);
+ if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
return (ENETDOWN);
}
@@ -526,16 +302,16 @@ epair_transmit_locked(struct ifnet *ifp, struct mbuf *m)
* In case the outgoing interface is not usable,
* drop the packet.
*/
+ sc = ifp->if_softc;
oifp = sc->oifp;
if ((oifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
- (oifp->if_flags & IFF_UP) ==0) {
+ (oifp->if_flags & IFF_UP) == 0) {
if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
m_freem(m);
return (0);
}
len = m->m_pkthdr.len;
mflags = m->m_flags;
- DPRINTF("packet %s -> %s\n", ifp->if_xname, oifp->if_xname);
#ifdef ALTQ
/* Support ALTQ via the classic if_start() path. */
@@ -549,99 +325,17 @@ epair_transmit_locked(struct ifnet *ifp, struct mbuf *m)
if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
if (mflags & (M_BCAST|M_MCAST))
if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
-
- if ((ifp->if_drv_flags & IFF_DRV_OACTIVE) == 0)
- epair_start_locked(ifp);
- else
- (void)epair_add_ifp_for_draining(ifp);
+ epair_start(ifp);
}
return (error);
}
IF_UNLOCK(&ifp->if_snd);
#endif
- if ((epair_dpcpu->epair_drv_flags & IFF_DRV_OACTIVE) != 0) {
- /*
- * Our hardware queue is full, try to fall back
- * queuing to the ifq but do not call ifp->if_start.
- * Either we are lucky or the packet is gone.
- */
- IFQ_ENQUEUE(&ifp->if_snd, m, error);
- if (!error)
- (void)epair_add_ifp_for_draining(ifp);
- return (error);
- }
-
- epair_clear_mbuf(m);
-
- sc = oifp->if_softc;
- /*
- * Add a reference so the interface cannot go while the
- * packet is in transit as we rely on rcvif to stay valid.
- */
- EPAIR_REFCOUNT_AQUIRE(&sc->refcount);
- m->m_pkthdr.rcvif = oifp;
- CURVNET_SET_QUIET(oifp->if_vnet);
- error = netisr_queue(NETISR_EPAIR, m);
- CURVNET_RESTORE();
- if (!error) {
- if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
- /*
- * IFQ_HANDOFF_ADJ/ip_handoff() update statistics,
- * but as we bypass all this we have to duplicate
- * the logic another time.
- */
- if_inc_counter(ifp, IFCOUNTER_OBYTES, len);
- if (mflags & (M_BCAST|M_MCAST))
- if_inc_counter(ifp, IFCOUNTER_OMCASTS, 1);
- /* Someone else received the packet. */
- if_inc_counter(oifp, IFCOUNTER_IPACKETS, 1);
- } else {
- /* The packet was freed already. */
- epair_dpcpu->epair_drv_flags |= IFF_DRV_OACTIVE;
- ifp->if_drv_flags |= IFF_DRV_OACTIVE;
- if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
- EPAIR_REFCOUNT_RELEASE(&sc->refcount);
- EPAIR_REFCOUNT_ASSERT((int)sc->refcount >= 1,
- ("%s: ifp=%p sc->refcount not >= 1: %d",
- __func__, oifp, sc->refcount));
- }
-
- return (error);
-}
-
-static int
-epair_transmit(struct ifnet *ifp, struct mbuf *m)
-{
- struct epair_dpcpu *epair_dpcpu;
- int error;
-
- epair_dpcpu = DPCPU_ID_PTR(cpuid_from_ifp(ifp), epair_dpcpu);
- EPAIR_LOCK(epair_dpcpu);
- error = epair_transmit_locked(ifp, m);
- EPAIR_UNLOCK(epair_dpcpu);
+ error = epair_menq(m, oifp->if_softc);
return (error);
}
-static void
-epair_qflush(struct ifnet *ifp)
-{
- struct epair_softc *sc;
-
- sc = ifp->if_softc;
- KASSERT(sc != NULL, ("%s: ifp=%p, epair_softc gone? sc=%p\n",
- __func__, ifp, sc));
- /*
- * Remove this ifp from all backpointer lists. The interface will not
- * usable for flushing anyway nor should it have anything to flush
- * after if_qflush().
- */
- epair_remove_ifp_from_draining(ifp);
-
- if (sc->if_qflush)
- sc->if_qflush(ifp);
-}
-
static int
epair_media_change(struct ifnet *ifp __unused)
{
@@ -709,8 +403,6 @@ epair_clone_match(struct if_clone *ifc, const char *name)
{
const char *cp;
- DPRINTF("name='%s'\n", name);
-
/*
* Our base name is epair.
* Our interfaces will be named epair<n>[ab].
@@ -799,16 +491,16 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
/* Allocate memory for both [ab] interfaces */
sca = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO);
- EPAIR_REFCOUNT_INIT(&sca->refcount, 1);
sca->ifp = if_alloc(IFT_ETHER);
if (sca->ifp == NULL) {
free(sca, M_EPAIR);
ifc_free_unit(ifc, unit);
return (ENOSPC);
}
+ sca->rxring[0] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK,NULL);
+ sca->rxring[1] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL);
scb = malloc(sizeof(struct epair_softc), M_EPAIR, M_WAITOK | M_ZERO);
- EPAIR_REFCOUNT_INIT(&scb->refcount, 1);
scb->ifp = if_alloc(IFT_ETHER);
if (scb->ifp == NULL) {
free(scb, M_EPAIR);
@@ -817,6 +509,8 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
ifc_free_unit(ifc, unit);
return (ENOSPC);
}
+ scb->rxring[0] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL);
+ scb->rxring[1] = buf_ring_alloc(RXRSIZE, M_EPAIR, M_WAITOK, NULL);
/*
* Cross-reference the interfaces so we will be able to free both.
@@ -824,16 +518,49 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
sca->oifp = scb->ifp;
scb->oifp = sca->ifp;
- /*
- * Calculate the cpuid for netisr queueing based on the
- * ifIndex of the interfaces. As long as we cannot configure
- * this or use cpuset information easily we cannot guarantee
- * cache locality but we can at least allow parallelism.
- */
- sca->cpuid =
- netisr_get_cpuid(sca->ifp->if_index);
- scb->cpuid =
- netisr_get_cpuid(scb->ifp->if_index);
+ EPAIR_LOCK();
+#ifdef SMP
+ /* Get an approximate distribution. */
+ hash = next_index % mp_ncpus;
+#else
+ hash = 0;
+#endif
+ if (swi_cookie[hash] == NULL) {
+ void *cookie;
+
+ EPAIR_UNLOCK();
+ error = swi_add(NULL, epairname,
+ epair_intr, (void *)(uintptr_t)hash,
+ SWI_NET, INTR_MPSAFE, &cookie);
+ if (error) {
+ buf_ring_free(scb->rxring[0], M_EPAIR);
+ buf_ring_free(scb->rxring[1], M_EPAIR);
+ if_free(scb->ifp);
+ free(scb, M_EPAIR);
+ buf_ring_free(sca->rxring[0], M_EPAIR);
+ buf_ring_free(sca->rxring[1], M_EPAIR);
+ if_free(sca->ifp);
+ free(sca, M_EPAIR);
+ ifc_free_unit(ifc, unit);
+ return (ENOSPC);
+ }
+ EPAIR_LOCK();
+ /* Recheck under lock even though a race is very unlikely. */
+ if (swi_cookie[hash] == NULL) {
+ swi_cookie[hash] = cookie;
+ } else {
+ EPAIR_UNLOCK();
+ (void) swi_remove(cookie);
+ EPAIR_LOCK();
+ }
+ }
+ sca->cpuidx = hash;
+ STAILQ_INSERT_TAIL(&swi_sc[hash], sca, entry);
+ sca->swi_cookie = swi_cookie[hash];
+ scb->cpuidx = hash;
+ STAILQ_INSERT_TAIL(&swi_sc[hash], scb, entry);
+ scb->swi_cookie = swi_cookie[hash];
+ EPAIR_UNLOCK();
/* Initialise pseudo media types. */
ifmedia_init(&sca->media, 0, epair_media_change, epair_media_status);
@@ -850,6 +577,7 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
ifp->if_dname = epairname;
ifp->if_dunit = unit;
ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
+ ifp->if_flags |= IFF_KNOWSEPOCH;
ifp->if_capabilities = IFCAP_VLAN_MTU;
ifp->if_capenable = IFCAP_VLAN_MTU;
ifp->if_start = epair_start;
@@ -870,12 +598,14 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
if (hostid == 0)
arc4rand(&hostid, sizeof(hostid), 0);
+ EPAIR_LOCK();
if (ifp->if_index > next_index)
next_index = ifp->if_index;
else
next_index++;
key[0] = (uint32_t)next_index;
+ EPAIR_UNLOCK();
key[1] = (uint32_t)(hostid & 0xffffffff);
key[2] = (uint32_t)((hostid >> 32) & 0xfffffffff);
hash = jenkins_hash32(key, 3, 0);
@@ -884,10 +614,8 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
memcpy(&eaddr[1], &hash, 4);
eaddr[5] = 0x0a;
ether_ifattach(ifp, eaddr);
- sca->if_qflush = ifp->if_qflush;
- ifp->if_qflush = epair_qflush;
- ifp->if_transmit = epair_transmit;
ifp->if_baudrate = IF_Gbps(10); /* arbitrary maximum */
+ ifp->if_transmit = epair_transmit;
/* Swap the name and finish initialization of interface <n>b. */
*dp = 'b';
@@ -912,27 +640,40 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params)
strlcpy(name, scb->ifp->if_xname, len);
epair_clone_add(ifc, scb);
- scb->if_qflush = ifp->if_qflush;
- ifp->if_qflush = epair_qflush;
- ifp->if_transmit = epair_transmit;
ifp->if_baudrate = IF_Gbps(10); /* arbitrary maximum */
+ ifp->if_transmit = epair_transmit;
/*
* Restore name to <n>a as the ifp for this will go into the
* cloner list for the initial call.
*/
strlcpy(name, sca->ifp->if_xname, len);
- DPRINTF("name='%s/%db' created sca=%p scb=%p\n", name, unit, sca, scb);
/* Tell the world, that we are ready to rock. */
sca->ifp->if_drv_flags |= IFF_DRV_RUNNING;
- scb->ifp->if_drv_flags |= IFF_DRV_RUNNING;
if_link_state_change(sca->ifp, LINK_STATE_UP);
+ scb->ifp->if_drv_flags |= IFF_DRV_RUNNING;
if_link_state_change(scb->ifp, LINK_STATE_UP);
return (0);
}
+static void
+epair_drain_rings(struct epair_softc *sc)
+{
+ int ridx;
+ struct mbuf *m;
+
+ for (ridx = 0; ridx < 2; ridx++) {
+ do {
+ m = buf_ring_dequeue_sc(sc->rxring[ridx]);
+ if (m == NULL)
+ break;
+ m_freem(m);
+ } while (1);
+ }
+}
+
static int
epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
{
@@ -940,8 +681,6 @@ epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
struct epair_softc *sca, *scb;
int unit, error;
- DPRINTF("ifp=%p\n", ifp);
-
/*
* In case we called into if_clone_destroyif() ourselves
* again to remove the second interface, the softc will be
@@ -955,27 +694,26 @@ epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
oifp = sca->oifp;
scb = oifp->if_softc;
- DPRINTF("ifp=%p oifp=%p\n", ifp, oifp);
+ /* Frist get the interfaces down and detached. */
if_link_state_change(ifp, LINK_STATE_DOWN);
- if_link_state_change(oifp, LINK_STATE_DOWN);
ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
+ if_link_state_change(oifp, LINK_STATE_DOWN);
oifp->if_drv_flags &= ~IFF_DRV_RUNNING;
- /*
- * Get rid of our second half. As the other of the two
- * interfaces may reside in a different vnet, we need to
- * switch before freeing them.
- */
- CURVNET_SET_QUIET(oifp->if_vnet);
+ ether_ifdetach(ifp);
ether_ifdetach(oifp);
- /*
- * Wait for all packets to be dispatched to if_input.
- * The numbers can only go down as the interface is
- * detached so there is no need to use atomics.
- */
- DPRINTF("scb refcnt=%u\n", scb->refcount);
- EPAIR_REFCOUNT_ASSERT(scb->refcount == 1,
- ("%s: ifp=%p scb->refcount!=1: %d", __func__, oifp, scb->refcount));
+
+ /* Second stop interrupt handler. */
+ EPAIR_LOCK();
+ STAILQ_REMOVE(&swi_sc[sca->cpuidx], sca, epair_softc, entry);
+ STAILQ_REMOVE(&swi_sc[scb->cpuidx], scb, epair_softc, entry);
+ EPAIR_UNLOCK();
+ sca->swi_cookie = NULL;
+ scb->swi_cookie = NULL;
+
+ /* Third free any queued packets and all the resources. */
+ CURVNET_SET_QUIET(oifp->if_vnet);
+ epair_drain_rings(scb);
oifp->if_softc = NULL;
error = if_clone_destroyif(ifc, oifp);
if (error)
@@ -983,19 +721,19 @@ epair_clone_destroy(struct if_clone *ifc, struct ifnet *ifp)
__func__, error);
if_free(oifp);
ifmedia_removeall(&scb->media);
+ buf_ring_free(scb->rxring[0], M_EPAIR);
+ buf_ring_free(scb->rxring[1], M_EPAIR);
*** 103 LINES SKIPPED ***