Index: head/sys/dev/netmap/netmap_generic.c =================================================================== --- head/sys/dev/netmap/netmap_generic.c (revision 321316) +++ head/sys/dev/netmap/netmap_generic.c (revision 321317) @@ -1,1254 +1,1262 @@ /* * Copyright (C) 2013-2016 Vincenzo Maffione * Copyright (C) 2013-2016 Luigi Rizzo * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ /* * This module implements netmap support on top of standard, * unmodified device drivers. * * A NIOCREGIF request is handled here if the device does not * have native support. TX and RX rings are emulated as follows: * * NIOCREGIF * We preallocate a block of TX mbufs (roughly as many as * tx descriptors; the number is not critical) to speed up * operation during transmissions. The refcount on most of * these buffers is artificially bumped up so we can recycle * them more easily. Also, the destructor is intercepted * so we use it as an interrupt notification to wake up * processes blocked on a poll(). * * For each receive ring we allocate one "struct mbq" * (an mbuf tailq plus a spinlock). We intercept packets * (through if_input) * on the receive path and put them in the mbq from which * netmap receive routines can grab them. * * TX: * in the generic_txsync() routine, netmap buffers are copied * (or linked, in a future) to the preallocated mbufs * and pushed to the transmit queue. Some of these mbufs * (those with NS_REPORT, or otherwise every half ring) * have the refcount=1, others have refcount=2. * When the destructor is invoked, we take that as * a notification that all mbufs up to that one in * the specific ring have been completed, and generate * the equivalent of a transmit interrupt. * * RX: * */ #ifdef __FreeBSD__ #include /* prerequisite */ __FBSDID("$FreeBSD$"); #include #include #include #include /* PROT_EXEC */ #include #include /* sockaddrs */ #include #include +#include #include #include /* bus_dmamap_* in netmap_kern.h */ // XXX temporary - D() defined here #include #include #include #define rtnl_lock() ND("rtnl_lock called") #define rtnl_unlock() ND("rtnl_unlock called") #define MBUF_RXQ(m) ((m)->m_pkthdr.flowid) #define smp_mb() /* * FreeBSD mbuf allocator/deallocator in emulation mode: */ #if __FreeBSD_version < 1100000 /* * For older versions of FreeBSD: * * We allocate EXT_PACKET mbuf+clusters, but need to set M_NOFREE * so that the destructor, if invoked, will not free the packet. * In principle we should set the destructor only on demand, * but since there might be a race we better do it on allocation. * As a consequence, we also need to set the destructor or we * would leak buffers. */ /* mbuf destructor, also need to change the type to EXT_EXTREF, * add an M_NOFREE flag, and then clear the flag and * chain into uma_zfree(zone_pack, mf) * (or reinstall the buffer ?) */ #define SET_MBUF_DESTRUCTOR(m, fn) do { \ (m)->m_ext.ext_free = (void *)fn; \ (m)->m_ext.ext_type = EXT_EXTREF; \ } while (0) static int void_mbuf_dtor(struct mbuf *m, void *arg1, void *arg2) { /* restore original mbuf */ m->m_ext.ext_buf = m->m_data = m->m_ext.ext_arg1; m->m_ext.ext_arg1 = NULL; m->m_ext.ext_type = EXT_PACKET; m->m_ext.ext_free = NULL; if (MBUF_REFCNT(m) == 0) SET_MBUF_REFCNT(m, 1); uma_zfree(zone_pack, m); return 0; } static inline struct mbuf * nm_os_get_mbuf(struct ifnet *ifp, int len) { struct mbuf *m; (void)ifp; m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR); if (m) { /* m_getcl() (mb_ctor_mbuf) has an assert that checks that * M_NOFREE flag is not specified as third argument, * so we have to set M_NOFREE after m_getcl(). */ m->m_flags |= M_NOFREE; m->m_ext.ext_arg1 = m->m_ext.ext_buf; // XXX save m->m_ext.ext_free = (void *)void_mbuf_dtor; m->m_ext.ext_type = EXT_EXTREF; ND(5, "create m %p refcnt %d", m, MBUF_REFCNT(m)); } return m; } #else /* __FreeBSD_version >= 1100000 */ /* * Newer versions of FreeBSD, using a straightforward scheme. * * We allocate mbufs with m_gethdr(), since the mbuf header is needed * by the driver. We also attach a customly-provided external storage, * which in this case is a netmap buffer. When calling m_extadd(), however * we pass a NULL address, since the real address (and length) will be * filled in by nm_os_generic_xmit_frame() right before calling * if_transmit(). * * The dtor function does nothing, however we need it since mb_free_ext() * has a KASSERT(), checking that the mbuf dtor function is not NULL. */ static void void_mbuf_dtor(struct mbuf *m, void *arg1, void *arg2) { } #define SET_MBUF_DESTRUCTOR(m, fn) do { \ (m)->m_ext.ext_free = (fn != NULL) ? \ (void *)fn : (void *)void_mbuf_dtor; \ } while (0) static inline struct mbuf * nm_os_get_mbuf(struct ifnet *ifp, int len) { struct mbuf *m; (void)ifp; (void)len; m = m_gethdr(M_NOWAIT, MT_DATA); if (m == NULL) { return m; } m_extadd(m, NULL /* buf */, 0 /* size */, void_mbuf_dtor, NULL, NULL, 0, EXT_NET_DRV); return m; } #endif /* __FreeBSD_version >= 1100000 */ #elif defined _WIN32 #include "win_glue.h" #define rtnl_lock() ND("rtnl_lock called") #define rtnl_unlock() ND("rtnl_unlock called") #define MBUF_TXQ(m) 0//((m)->m_pkthdr.flowid) #define MBUF_RXQ(m) 0//((m)->m_pkthdr.flowid) #define smp_mb() //XXX: to be correctly defined #else /* linux */ #include "bsd_glue.h" #include /* rtnl_[un]lock() */ #include /* struct ethtool_ops, get_ringparam */ #include static inline struct mbuf * nm_os_get_mbuf(struct ifnet *ifp, int len) { return alloc_skb(ifp->needed_headroom + len + ifp->needed_tailroom, GFP_ATOMIC); } #endif /* linux */ /* Common headers. */ #include #include #include #define for_each_kring_n(_i, _k, _karr, _n) \ for (_k=_karr, _i = 0; _i < _n; (_k)++, (_i)++) #define for_each_tx_kring(_i, _k, _na) \ for_each_kring_n(_i, _k, (_na)->tx_rings, (_na)->num_tx_rings) #define for_each_tx_kring_h(_i, _k, _na) \ for_each_kring_n(_i, _k, (_na)->tx_rings, (_na)->num_tx_rings + 1) #define for_each_rx_kring(_i, _k, _na) \ for_each_kring_n(_i, _k, (_na)->rx_rings, (_na)->num_rx_rings) #define for_each_rx_kring_h(_i, _k, _na) \ for_each_kring_n(_i, _k, (_na)->rx_rings, (_na)->num_rx_rings + 1) /* ======================== PERFORMANCE STATISTICS =========================== */ #ifdef RATE_GENERIC #define IFRATE(x) x struct rate_stats { unsigned long txpkt; unsigned long txsync; unsigned long txirq; unsigned long txrepl; unsigned long txdrop; unsigned long rxpkt; unsigned long rxirq; unsigned long rxsync; }; struct rate_context { unsigned refcount; struct timer_list timer; struct rate_stats new; struct rate_stats old; }; #define RATE_PRINTK(_NAME_) \ printk( #_NAME_ " = %lu Hz\n", (cur._NAME_ - ctx->old._NAME_)/RATE_PERIOD); #define RATE_PERIOD 2 static void rate_callback(unsigned long arg) { struct rate_context * ctx = (struct rate_context *)arg; struct rate_stats cur = ctx->new; int r; RATE_PRINTK(txpkt); RATE_PRINTK(txsync); RATE_PRINTK(txirq); RATE_PRINTK(txrepl); RATE_PRINTK(txdrop); RATE_PRINTK(rxpkt); RATE_PRINTK(rxsync); RATE_PRINTK(rxirq); printk("\n"); ctx->old = cur; r = mod_timer(&ctx->timer, jiffies + msecs_to_jiffies(RATE_PERIOD * 1000)); if (unlikely(r)) D("[v1000] Error: mod_timer()"); } static struct rate_context rate_ctx; void generic_rate(int txp, int txs, int txi, int rxp, int rxs, int rxi) { if (txp) rate_ctx.new.txpkt++; if (txs) rate_ctx.new.txsync++; if (txi) rate_ctx.new.txirq++; if (rxp) rate_ctx.new.rxpkt++; if (rxs) rate_ctx.new.rxsync++; if (rxi) rate_ctx.new.rxirq++; } #else /* !RATE */ #define IFRATE(x) #endif /* !RATE */ /* ========== GENERIC (EMULATED) NETMAP ADAPTER SUPPORT ============= */ /* * Wrapper used by the generic adapter layer to notify * the poller threads. Differently from netmap_rx_irq(), we check * only NAF_NETMAP_ON instead of NAF_NATIVE_ON to enable the irq. */ void netmap_generic_irq(struct netmap_adapter *na, u_int q, u_int *work_done) { if (unlikely(!nm_netmap_on(na))) return; netmap_common_irq(na, q, work_done); #ifdef RATE_GENERIC if (work_done) rate_ctx.new.rxirq++; else rate_ctx.new.txirq++; #endif /* RATE_GENERIC */ } static int generic_netmap_unregister(struct netmap_adapter *na) { struct netmap_generic_adapter *gna = (struct netmap_generic_adapter *)na; struct netmap_kring *kring = NULL; int i, r; if (na->active_fds == 0) { rtnl_lock(); na->na_flags &= ~NAF_NETMAP_ON; /* Release packet steering control. */ nm_os_catch_tx(gna, 0); /* Stop intercepting packets on the RX path. */ nm_os_catch_rx(gna, 0); rtnl_unlock(); } for_each_rx_kring_h(r, kring, na) { if (nm_kring_pending_off(kring)) { D("Emulated adapter: ring '%s' deactivated", kring->name); kring->nr_mode = NKR_NETMAP_OFF; } } for_each_tx_kring_h(r, kring, na) { if (nm_kring_pending_off(kring)) { kring->nr_mode = NKR_NETMAP_OFF; D("Emulated adapter: ring '%s' deactivated", kring->name); } } for_each_rx_kring(r, kring, na) { /* Free the mbufs still pending in the RX queues, * that did not end up into the corresponding netmap * RX rings. */ mbq_safe_purge(&kring->rx_queue); nm_os_mitigation_cleanup(&gna->mit[r]); } /* Decrement reference counter for the mbufs in the * TX pools. These mbufs can be still pending in drivers, * (e.g. this happens with virtio-net driver, which * does lazy reclaiming of transmitted mbufs). */ for_each_tx_kring(r, kring, na) { /* We must remove the destructor on the TX event, * because the destructor invokes netmap code, and * the netmap module may disappear before the * TX event is consumed. */ mtx_lock_spin(&kring->tx_event_lock); if (kring->tx_event) { SET_MBUF_DESTRUCTOR(kring->tx_event, NULL); } kring->tx_event = NULL; mtx_unlock_spin(&kring->tx_event_lock); } if (na->active_fds == 0) { nm_os_free(gna->mit); for_each_rx_kring(r, kring, na) { mbq_safe_fini(&kring->rx_queue); } for_each_tx_kring(r, kring, na) { mtx_destroy(&kring->tx_event_lock); if (kring->tx_pool == NULL) { continue; } for (i=0; inum_tx_desc; i++) { if (kring->tx_pool[i]) { m_freem(kring->tx_pool[i]); } } nm_os_free(kring->tx_pool); kring->tx_pool = NULL; } #ifdef RATE_GENERIC if (--rate_ctx.refcount == 0) { D("del_timer()"); del_timer(&rate_ctx.timer); } #endif D("Emulated adapter for %s deactivated", na->name); } return 0; } /* Enable/disable netmap mode for a generic network interface. */ static int generic_netmap_register(struct netmap_adapter *na, int enable) { struct netmap_generic_adapter *gna = (struct netmap_generic_adapter *)na; struct netmap_kring *kring = NULL; int error; int i, r; if (!na) { return EINVAL; } if (!enable) { /* This is actually an unregif. */ return generic_netmap_unregister(na); } if (na->active_fds == 0) { D("Emulated adapter for %s activated", na->name); /* Do all memory allocations when (na->active_fds == 0), to * simplify error management. */ /* Allocate memory for mitigation support on all the rx queues. */ gna->mit = nm_os_malloc(na->num_rx_rings * sizeof(struct nm_generic_mit)); if (!gna->mit) { D("mitigation allocation failed"); error = ENOMEM; goto out; } for_each_rx_kring(r, kring, na) { /* Init mitigation support. */ nm_os_mitigation_init(&gna->mit[r], r, na); /* Initialize the rx queue, as generic_rx_handler() can * be called as soon as nm_os_catch_rx() returns. */ mbq_safe_init(&kring->rx_queue); } /* * Prepare mbuf pools (parallel to the tx rings), for packet * transmission. Don't preallocate the mbufs here, it's simpler * to leave this task to txsync. */ for_each_tx_kring(r, kring, na) { kring->tx_pool = NULL; } for_each_tx_kring(r, kring, na) { kring->tx_pool = nm_os_malloc(na->num_tx_desc * sizeof(struct mbuf *)); if (!kring->tx_pool) { D("tx_pool allocation failed"); error = ENOMEM; goto free_tx_pools; } mtx_init(&kring->tx_event_lock, "tx_event_lock", NULL, MTX_SPIN); } } for_each_rx_kring_h(r, kring, na) { if (nm_kring_pending_on(kring)) { D("Emulated adapter: ring '%s' activated", kring->name); kring->nr_mode = NKR_NETMAP_ON; } } for_each_tx_kring_h(r, kring, na) { if (nm_kring_pending_on(kring)) { D("Emulated adapter: ring '%s' activated", kring->name); kring->nr_mode = NKR_NETMAP_ON; } } for_each_tx_kring(r, kring, na) { /* Initialize tx_pool and tx_event. */ for (i=0; inum_tx_desc; i++) { kring->tx_pool[i] = NULL; } kring->tx_event = NULL; } if (na->active_fds == 0) { rtnl_lock(); /* Prepare to intercept incoming traffic. */ error = nm_os_catch_rx(gna, 1); if (error) { D("nm_os_catch_rx(1) failed (%d)", error); goto register_handler; } /* Make netmap control the packet steering. */ error = nm_os_catch_tx(gna, 1); if (error) { D("nm_os_catch_tx(1) failed (%d)", error); goto catch_rx; } rtnl_unlock(); na->na_flags |= NAF_NETMAP_ON; #ifdef RATE_GENERIC if (rate_ctx.refcount == 0) { D("setup_timer()"); memset(&rate_ctx, 0, sizeof(rate_ctx)); setup_timer(&rate_ctx.timer, &rate_callback, (unsigned long)&rate_ctx); if (mod_timer(&rate_ctx.timer, jiffies + msecs_to_jiffies(1500))) { D("Error: mod_timer()"); } } rate_ctx.refcount++; #endif /* RATE */ } return 0; /* Here (na->active_fds == 0) holds. */ catch_rx: nm_os_catch_rx(gna, 0); register_handler: rtnl_unlock(); free_tx_pools: for_each_tx_kring(r, kring, na) { mtx_destroy(&kring->tx_event_lock); if (kring->tx_pool == NULL) { continue; } nm_os_free(kring->tx_pool); kring->tx_pool = NULL; } for_each_rx_kring(r, kring, na) { mbq_safe_fini(&kring->rx_queue); } nm_os_free(gna->mit); out: return error; } /* * Callback invoked when the device driver frees an mbuf used * by netmap to transmit a packet. This usually happens when * the NIC notifies the driver that transmission is completed. */ static void generic_mbuf_destructor(struct mbuf *m) { struct netmap_adapter *na = NA(GEN_TX_MBUF_IFP(m)); struct netmap_kring *kring; unsigned int r = MBUF_TXQ(m); unsigned int r_orig = r; if (unlikely(!nm_netmap_on(na) || r >= na->num_tx_rings)) { D("Error: no netmap adapter on device %p", GEN_TX_MBUF_IFP(m)); return; } /* * First, clear the event mbuf. * In principle, the event 'm' should match the one stored * on ring 'r'. However we check it explicitely to stay * safe against lower layers (qdisc, driver, etc.) changing * MBUF_TXQ(m) under our feet. If the match is not found * on 'r', we try to see if it belongs to some other ring. */ for (;;) { bool match = false; kring = &na->tx_rings[r]; mtx_lock_spin(&kring->tx_event_lock); if (kring->tx_event == m) { kring->tx_event = NULL; match = true; } mtx_unlock_spin(&kring->tx_event_lock); if (match) { if (r != r_orig) { RD(1, "event %p migrated: ring %u --> %u", m, r_orig, r); } break; } if (++r == na->num_tx_rings) r = 0; if (r == r_orig) { RD(1, "Cannot match event %p", m); return; } } /* Second, wake up clients. They will reclaim the event through * txsync. */ netmap_generic_irq(na, r, NULL); #ifdef __FreeBSD__ void_mbuf_dtor(m, NULL, NULL); #endif } /* Record completed transmissions and update hwtail. * * The oldest tx buffer not yet completed is at nr_hwtail + 1, * nr_hwcur is the first unsent buffer. */ static u_int generic_netmap_tx_clean(struct netmap_kring *kring, int txqdisc) { u_int const lim = kring->nkr_num_slots - 1; u_int nm_i = nm_next(kring->nr_hwtail, lim); u_int hwcur = kring->nr_hwcur; u_int n = 0; struct mbuf **tx_pool = kring->tx_pool; ND("hwcur = %d, hwtail = %d", kring->nr_hwcur, kring->nr_hwtail); while (nm_i != hwcur) { /* buffers not completed */ struct mbuf *m = tx_pool[nm_i]; if (txqdisc) { if (m == NULL) { /* Nothing to do, this is going * to be replenished. */ RD(3, "Is this happening?"); } else if (MBUF_QUEUED(m)) { break; /* Not dequeued yet. */ } else if (MBUF_REFCNT(m) != 1) { /* This mbuf has been dequeued but is still busy * (refcount is 2). * Leave it to the driver and replenish. */ m_freem(m); tx_pool[nm_i] = NULL; } } else { if (unlikely(m == NULL)) { int event_consumed; /* This slot was used to place an event. */ mtx_lock_spin(&kring->tx_event_lock); event_consumed = (kring->tx_event == NULL); mtx_unlock_spin(&kring->tx_event_lock); if (!event_consumed) { /* The event has not been consumed yet, * still busy in the driver. */ break; } /* The event has been consumed, we can go * ahead. */ } else if (MBUF_REFCNT(m) != 1) { /* This mbuf is still busy: its refcnt is 2. */ break; } } n++; nm_i = nm_next(nm_i, lim); } kring->nr_hwtail = nm_prev(nm_i, lim); ND("tx completed [%d] -> hwtail %d", n, kring->nr_hwtail); return n; } /* Compute a slot index in the middle between inf and sup. */ static inline u_int ring_middle(u_int inf, u_int sup, u_int lim) { u_int n = lim + 1; u_int e; if (sup >= inf) { e = (sup + inf) / 2; } else { /* wrap around */ e = (sup + n + inf) / 2; if (e >= n) { e -= n; } } if (unlikely(e >= n)) { D("This cannot happen"); e = 0; } return e; } static void generic_set_tx_event(struct netmap_kring *kring, u_int hwcur) { u_int lim = kring->nkr_num_slots - 1; struct mbuf *m; u_int e; u_int ntc = nm_next(kring->nr_hwtail, lim); /* next to clean */ if (ntc == hwcur) { return; /* all buffers are free */ } /* * We have pending packets in the driver between hwtail+1 * and hwcur, and we have to chose one of these slot to * generate a notification. * There is a race but this is only called within txsync which * does a double check. */ #if 0 /* Choose a slot in the middle, so that we don't risk ending * up in a situation where the client continuously wake up, * fills one or a few TX slots and go to sleep again. */ e = ring_middle(ntc, hwcur, lim); #else /* Choose the first pending slot, to be safe against driver * reordering mbuf transmissions. */ e = ntc; #endif m = kring->tx_pool[e]; if (m == NULL) { /* An event is already in place. */ return; } mtx_lock_spin(&kring->tx_event_lock); if (kring->tx_event) { /* An event is already in place. */ mtx_unlock_spin(&kring->tx_event_lock); return; } SET_MBUF_DESTRUCTOR(m, generic_mbuf_destructor); kring->tx_event = m; mtx_unlock_spin(&kring->tx_event_lock); kring->tx_pool[e] = NULL; ND(5, "Request Event at %d mbuf %p refcnt %d", e, m, m ? MBUF_REFCNT(m) : -2 ); /* Decrement the refcount. This will free it if we lose the race * with the driver. */ m_freem(m); smp_mb(); } /* * generic_netmap_txsync() transforms netmap buffers into mbufs * and passes them to the standard device driver * (ndo_start_xmit() or ifp->if_transmit() ). * On linux this is not done directly, but using dev_queue_xmit(), * since it implements the TX flow control (and takes some locks). */ static int generic_netmap_txsync(struct netmap_kring *kring, int flags) { struct netmap_adapter *na = kring->na; struct netmap_generic_adapter *gna = (struct netmap_generic_adapter *)na; struct ifnet *ifp = na->ifp; struct netmap_ring *ring = kring->ring; u_int nm_i; /* index into the netmap ring */ // j u_int const lim = kring->nkr_num_slots - 1; u_int const head = kring->rhead; u_int ring_nr = kring->ring_id; IFRATE(rate_ctx.new.txsync++); rmb(); /* * First part: process new packets to send. */ nm_i = kring->nr_hwcur; if (nm_i != head) { /* we have new packets to send */ struct nm_os_gen_arg a; u_int event = -1; if (gna->txqdisc && nm_kr_txempty(kring)) { /* In txqdisc mode, we ask for a delayed notification, * but only when cur == hwtail, which means that the * client is going to block. */ event = ring_middle(nm_i, head, lim); ND(3, "Place txqdisc event (hwcur=%u,event=%u," "head=%u,hwtail=%u)", nm_i, event, head, kring->nr_hwtail); } a.ifp = ifp; a.ring_nr = ring_nr; a.head = a.tail = NULL; while (nm_i != head) { struct netmap_slot *slot = &ring->slot[nm_i]; u_int len = slot->len; void *addr = NMB(na, slot); /* device-specific */ struct mbuf *m; int tx_ret; NM_CHECK_ADDR_LEN(na, addr, len); /* Tale a mbuf from the tx pool (replenishing the pool * entry if necessary) and copy in the user packet. */ m = kring->tx_pool[nm_i]; if (unlikely(m == NULL)) { kring->tx_pool[nm_i] = m = nm_os_get_mbuf(ifp, NETMAP_BUF_SIZE(na)); if (m == NULL) { RD(2, "Failed to replenish mbuf"); /* Here we could schedule a timer which * retries to replenish after a while, * and notifies the client when it * manages to replenish some slots. In * any case we break early to avoid * crashes. */ break; } IFRATE(rate_ctx.new.txrepl++); } a.m = m; a.addr = addr; a.len = len; a.qevent = (nm_i == event); /* When not in txqdisc mode, we should ask * notifications when NS_REPORT is set, or roughly * every half ring. To optimize this, we set a * notification event when the client runs out of * TX ring space, or when transmission fails. In * the latter case we also break early. */ tx_ret = nm_os_generic_xmit_frame(&a); if (unlikely(tx_ret)) { if (!gna->txqdisc) { /* * No room for this mbuf in the device driver. * Request a notification FOR A PREVIOUS MBUF, * then call generic_netmap_tx_clean(kring) to do the * double check and see if we can free more buffers. * If there is space continue, else break; * NOTE: the double check is necessary if the problem * occurs in the txsync call after selrecord(). * Also, we need some way to tell the caller that not * all buffers were queued onto the device (this was * not a problem with native netmap driver where space * is preallocated). The bridge has a similar problem * and we solve it there by dropping the excess packets. */ generic_set_tx_event(kring, nm_i); if (generic_netmap_tx_clean(kring, gna->txqdisc)) { /* space now available */ continue; } else { break; } } /* In txqdisc mode, the netmap-aware qdisc * queue has the same length as the number of * netmap slots (N). Since tail is advanced * only when packets are dequeued, qdisc * queue overrun cannot happen, so * nm_os_generic_xmit_frame() did not fail * because of that. * However, packets can be dropped because * carrier is off, or because our qdisc is * being deactivated, or possibly for other * reasons. In these cases, we just let the * packet to be dropped. */ IFRATE(rate_ctx.new.txdrop++); } slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED); nm_i = nm_next(nm_i, lim); IFRATE(rate_ctx.new.txpkt++); } if (a.head != NULL) { a.addr = NULL; nm_os_generic_xmit_frame(&a); } /* Update hwcur to the next slot to transmit. Here nm_i * is not necessarily head, we could break early. */ kring->nr_hwcur = nm_i; } /* * Second, reclaim completed buffers */ if (!gna->txqdisc && (flags & NAF_FORCE_RECLAIM || nm_kr_txempty(kring))) { /* No more available slots? Set a notification event * on a netmap slot that will be cleaned in the future. * No doublecheck is performed, since txsync() will be * called twice by netmap_poll(). */ generic_set_tx_event(kring, nm_i); } generic_netmap_tx_clean(kring, gna->txqdisc); return 0; } /* * This handler is registered (through nm_os_catch_rx()) * within the attached network interface * in the RX subsystem, so that every mbuf passed up by * the driver can be stolen to the network stack. * Stolen packets are put in a queue where the * generic_netmap_rxsync() callback can extract them. * Returns 1 if the packet was stolen, 0 otherwise. */ int generic_rx_handler(struct ifnet *ifp, struct mbuf *m) { struct netmap_adapter *na = NA(ifp); struct netmap_generic_adapter *gna = (struct netmap_generic_adapter *)na; struct netmap_kring *kring; u_int work_done; u_int r = MBUF_RXQ(m); /* receive ring number */ if (r >= na->num_rx_rings) { r = r % na->num_rx_rings; } kring = &na->rx_rings[r]; if (kring->nr_mode == NKR_NETMAP_OFF) { /* We must not intercept this mbuf. */ return 0; } /* limit the size of the queue */ if (unlikely(!gna->rxsg && MBUF_LEN(m) > NETMAP_BUF_SIZE(na))) { /* This may happen when GRO/LRO features are enabled for * the NIC driver when the generic adapter does not * support RX scatter-gather. */ RD(2, "Warning: driver pushed up big packet " "(size=%d)", (int)MBUF_LEN(m)); m_freem(m); } else if (unlikely(mbq_len(&kring->rx_queue) > 1024)) { m_freem(m); } else { mbq_safe_enqueue(&kring->rx_queue, m); } if (netmap_generic_mit < 32768) { /* no rx mitigation, pass notification up */ netmap_generic_irq(na, r, &work_done); } else { /* same as send combining, filter notification if there is a * pending timer, otherwise pass it up and start a timer. */ if (likely(nm_os_mitigation_active(&gna->mit[r]))) { /* Record that there is some pending work. */ gna->mit[r].mit_pending = 1; } else { netmap_generic_irq(na, r, &work_done); nm_os_mitigation_start(&gna->mit[r]); } } /* We have intercepted the mbuf. */ return 1; } /* * generic_netmap_rxsync() extracts mbufs from the queue filled by * generic_netmap_rx_handler() and puts their content in the netmap * receive ring. * Access must be protected because the rx handler is asynchronous, */ static int generic_netmap_rxsync(struct netmap_kring *kring, int flags) { struct netmap_ring *ring = kring->ring; struct netmap_adapter *na = kring->na; u_int nm_i; /* index into the netmap ring */ //j, u_int n; u_int const lim = kring->nkr_num_slots - 1; u_int const head = kring->rhead; int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR; /* Adapter-specific variables. */ uint16_t slot_flags = kring->nkr_slot_flags; u_int nm_buf_len = NETMAP_BUF_SIZE(na); struct mbq tmpq; struct mbuf *m; int avail; /* in bytes */ int mlen; int copy; if (head > lim) return netmap_ring_reinit(kring); IFRATE(rate_ctx.new.rxsync++); /* * First part: skip past packets that userspace has released. * This can possibly make room for the second part. */ nm_i = kring->nr_hwcur; if (nm_i != head) { /* Userspace has released some packets. */ for (n = 0; nm_i != head; n++) { struct netmap_slot *slot = &ring->slot[nm_i]; slot->flags &= ~NS_BUF_CHANGED; nm_i = nm_next(nm_i, lim); } kring->nr_hwcur = head; } /* * Second part: import newly received packets. */ if (!netmap_no_pendintr && !force_update) { return 0; } nm_i = kring->nr_hwtail; /* First empty slot in the receive ring. */ /* Compute the available space (in bytes) in this netmap ring. * The first slot that is not considered in is the one before * nr_hwcur. */ avail = nm_prev(kring->nr_hwcur, lim) - nm_i; if (avail < 0) avail += lim + 1; avail *= nm_buf_len; /* First pass: While holding the lock on the RX mbuf queue, * extract as many mbufs as they fit the available space, * and put them in a temporary queue. * To avoid performing a per-mbuf division (mlen / nm_buf_len) to * to update avail, we do the update in a while loop that we * also use to set the RX slots, but without performing the copy. */ mbq_init(&tmpq); mbq_lock(&kring->rx_queue); for (n = 0;; n++) { m = mbq_peek(&kring->rx_queue); if (!m) { /* No more packets from the driver. */ break; } mlen = MBUF_LEN(m); if (mlen > avail) { /* No more space in the ring. */ break; } mbq_dequeue(&kring->rx_queue); while (mlen) { copy = nm_buf_len; if (mlen < copy) { copy = mlen; } mlen -= copy; avail -= nm_buf_len; ring->slot[nm_i].len = copy; ring->slot[nm_i].flags = slot_flags | (mlen ? NS_MOREFRAG : 0); nm_i = nm_next(nm_i, lim); } mbq_enqueue(&tmpq, m); } mbq_unlock(&kring->rx_queue); /* Second pass: Drain the temporary queue, going over the used RX slots, * and perform the copy out of the RX queue lock. */ nm_i = kring->nr_hwtail; for (;;) { void *nmaddr; int ofs = 0; int morefrag; m = mbq_dequeue(&tmpq); if (!m) { break; } do { nmaddr = NMB(na, &ring->slot[nm_i]); /* We only check the address here on generic rx rings. */ if (nmaddr == NETMAP_BUF_BASE(na)) { /* Bad buffer */ m_freem(m); mbq_purge(&tmpq); mbq_fini(&tmpq); return netmap_ring_reinit(kring); } copy = ring->slot[nm_i].len; m_copydata(m, ofs, copy, nmaddr); ofs += copy; morefrag = ring->slot[nm_i].flags & NS_MOREFRAG; nm_i = nm_next(nm_i, lim); } while (morefrag); m_freem(m); } mbq_fini(&tmpq); if (n) { kring->nr_hwtail = nm_i; IFRATE(rate_ctx.new.rxpkt += n); } kring->nr_kflags &= ~NKR_PENDINTR; return 0; } static void generic_netmap_dtor(struct netmap_adapter *na) { struct netmap_generic_adapter *gna = (struct netmap_generic_adapter*)na; struct ifnet *ifp = netmap_generic_getifp(gna); struct netmap_adapter *prev_na = gna->prev; if (prev_na != NULL) { netmap_adapter_put(prev_na); if (nm_iszombie(na)) { /* * The driver has been removed without releasing * the reference so we need to do it here. */ netmap_adapter_put(prev_na); } D("Native netmap adapter %p restored", prev_na); } NM_ATTACH_NA(ifp, prev_na); /* * netmap_detach_common(), that it's called after this function, * overrides WNA(ifp) if na->ifp is not NULL. */ na->ifp = NULL; D("Emulated netmap adapter for %s destroyed", na->name); } int na_is_generic(struct netmap_adapter *na) { return na->nm_register == generic_netmap_register; } /* * generic_netmap_attach() makes it possible to use netmap on * a device without native netmap support. * This is less performant than native support but potentially * faster than raw sockets or similar schemes. * * In this "emulated" mode, netmap rings do not necessarily * have the same size as those in the NIC. We use a default * value and possibly override it if the OS has ways to fetch the * actual configuration. */ int generic_netmap_attach(struct ifnet *ifp) { struct netmap_adapter *na; struct netmap_generic_adapter *gna; int retval; u_int num_tx_desc, num_rx_desc; + +#ifdef __FreeBSD__ + if (ifp->if_type == IFT_LOOP) { + D("if_loop is not supported by %s", __func__); + return EINVAL; + } +#endif num_tx_desc = num_rx_desc = netmap_generic_ringsize; /* starting point */ nm_os_generic_find_num_desc(ifp, &num_tx_desc, &num_rx_desc); /* ignore errors */ ND("Netmap ring size: TX = %d, RX = %d", num_tx_desc, num_rx_desc); if (num_tx_desc == 0 || num_rx_desc == 0) { D("Device has no hw slots (tx %u, rx %u)", num_tx_desc, num_rx_desc); return EINVAL; } gna = nm_os_malloc(sizeof(*gna)); if (gna == NULL) { D("no memory on attach, give up"); return ENOMEM; } na = (struct netmap_adapter *)gna; strncpy(na->name, ifp->if_xname, sizeof(na->name)); na->ifp = ifp; na->num_tx_desc = num_tx_desc; na->num_rx_desc = num_rx_desc; na->nm_register = &generic_netmap_register; na->nm_txsync = &generic_netmap_txsync; na->nm_rxsync = &generic_netmap_rxsync; na->nm_dtor = &generic_netmap_dtor; /* when using generic, NAF_NETMAP_ON is set so we force * NAF_SKIP_INTR to use the regular interrupt handler */ na->na_flags = NAF_SKIP_INTR | NAF_HOST_RINGS; ND("[GNA] num_tx_queues(%d), real_num_tx_queues(%d), len(%lu)", ifp->num_tx_queues, ifp->real_num_tx_queues, ifp->tx_queue_len); ND("[GNA] num_rx_queues(%d), real_num_rx_queues(%d)", ifp->num_rx_queues, ifp->real_num_rx_queues); nm_os_generic_find_num_queues(ifp, &na->num_tx_rings, &na->num_rx_rings); retval = netmap_attach_common(na); if (retval) { nm_os_free(gna); return retval; } gna->prev = NA(ifp); /* save old na */ if (gna->prev != NULL) { netmap_adapter_get(gna->prev); } NM_ATTACH_NA(ifp, na); nm_os_generic_set_features(gna); D("Emulated adapter for %s created (prev was %p)", na->name, gna->prev); return retval; }