The branch main has been updated by kp: URL: https://cgit.FreeBSD.org/src/commit/?id=3dd5760aa5f876f8a3f0735afeebdf9ee414e1f5
commit 3dd5760aa5f876f8a3f0735afeebdf9ee414e1f5 Author: Bjoern A. Zeeb <[email protected]> AuthorDate: 2021-10-09 14:09:04 +0000 Commit: Kristof Provost <[email protected]> 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 <[email protected]> * All rights reserved. + * Copyright (c) 2009-2021 Bjoern A. Zeeb <[email protected]> * * 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 ***
