2 * Copyright (C) 2013-2014 Universita` di Pisa. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
16 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
19 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
20 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * This module implements netmap support on top of standard,
28 * unmodified device drivers.
30 * A NIOCREGIF request is handled here if the device does not
31 * have native support. TX and RX rings are emulated as follows:
34 * We preallocate a block of TX mbufs (roughly as many as
35 * tx descriptors; the number is not critical) to speed up
36 * operation during transmissions. The refcount on most of
37 * these buffers is artificially bumped up so we can recycle
38 * them more easily. Also, the destructor is intercepted
39 * so we use it as an interrupt notification to wake up
40 * processes blocked on a poll().
42 * For each receive ring we allocate one "struct mbq"
43 * (an mbuf tailq plus a spinlock). We intercept packets
45 * on the receive path and put them in the mbq from which
46 * netmap receive routines can grab them.
49 * in the generic_txsync() routine, netmap buffers are copied
50 * (or linked, in a future) to the preallocated mbufs
51 * and pushed to the transmit queue. Some of these mbufs
52 * (those with NS_REPORT, or otherwise every half ring)
53 * have the refcount=1, others have refcount=2.
54 * When the destructor is invoked, we take that as
55 * a notification that all mbufs up to that one in
56 * the specific ring have been completed, and generate
57 * the equivalent of a transmit interrupt.
65 #include <sys/cdefs.h> /* prerequisite */
66 __FBSDID("$FreeBSD$");
68 #include <sys/types.h>
69 #include <sys/errno.h>
70 #include <sys/malloc.h>
71 #include <sys/lock.h> /* PROT_EXEC */
72 #include <sys/rwlock.h>
73 #include <sys/socket.h> /* sockaddrs */
74 #include <sys/selinfo.h>
76 #include <net/if_var.h>
77 #include <machine/bus.h> /* bus_dmamap_* in netmap_kern.h */
79 // XXX temporary - D() defined here
80 #include <net/netmap.h>
81 #include <dev/netmap/netmap_kern.h>
82 #include <dev/netmap/netmap_mem2.h>
84 #define rtnl_lock() ND("rtnl_lock called")
85 #define rtnl_unlock() ND("rtnl_unlock called")
86 #define MBUF_TXQ(m) ((m)->m_pkthdr.flowid)
87 #define MBUF_RXQ(m) ((m)->m_pkthdr.flowid)
91 * FreeBSD mbuf allocator/deallocator in emulation mode:
93 * We allocate EXT_PACKET mbuf+clusters, but need to set M_NOFREE
94 * so that the destructor, if invoked, will not free the packet.
95 * In principle we should set the destructor only on demand,
96 * but since there might be a race we better do it on allocation.
97 * As a consequence, we also need to set the destructor or we
106 * mbuf destructor, also need to change the type to EXT_EXTREF,
107 * add an M_NOFREE flag, and then clear the flag and
108 * chain into uma_zfree(zone_pack, mf)
109 * (or reinstall the buffer ?)
111 * On FreeBSD 9 the destructor is called as ext_free(ext_arg1, ext_arg2)
112 * whereas newer version have ext_free(m, ext_arg1, ext_arg2)
113 * For compatibility we set ext_arg1 = m on allocation so we have
114 * the same code on both.
116 #define SET_MBUF_DESTRUCTOR(m, fn) do { \
117 (m)->m_ext.ext_free = (void *)fn; \
118 (m)->m_ext.ext_type = EXT_EXTREF; \
122 netmap_default_mbuf_destructor(struct mbuf *m)
124 /* restore original data pointer and type */
125 m->m_ext.ext_buf = m->m_data = m->m_ext.ext_arg2;
126 m->m_ext.ext_type = EXT_PACKET;
127 m->m_ext.ext_free = NULL;
128 m->m_ext.ext_arg1 = m->m_ext.ext_arg2 = NULL;
129 if (*(m->m_ext.ext_cnt) == 0)
130 *(m->m_ext.ext_cnt) = 1;
131 uma_zfree(zone_pack, m);
134 static inline struct mbuf *
135 netmap_get_mbuf(int len)
138 m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR | M_NOFREE);
140 m->m_ext.ext_arg1 = m; /* FreeBSD 9 compat */
141 m->m_ext.ext_arg2 = m->m_ext.ext_buf; /* save original */
142 m->m_ext.ext_free = (void *)netmap_default_mbuf_destructor;
143 m->m_ext.ext_type = EXT_EXTREF;
144 ND(5, "create m %p refcnt %d", m, *m->m_ext.ext_cnt);
149 #define GET_MBUF_REFCNT(m) ((m)->m_ext.ext_cnt ? *(m)->m_ext.ext_cnt : -1)
155 #include "bsd_glue.h"
157 #include <linux/rtnetlink.h> /* rtnl_[un]lock() */
158 #include <linux/ethtool.h> /* struct ethtool_ops, get_ringparam */
159 #include <linux/hrtimer.h>
161 //#define RATE /* Enables communication statistics. */
168 /* Common headers. */
169 #include <net/netmap.h>
170 #include <dev/netmap/netmap_kern.h>
171 #include <dev/netmap/netmap_mem2.h>
175 /* ======================== usage stats =========================== */
181 unsigned long txsync;
185 unsigned long rxsync;
188 struct rate_context {
190 struct timer_list timer;
191 struct rate_stats new;
192 struct rate_stats old;
195 #define RATE_PRINTK(_NAME_) \
196 printk( #_NAME_ " = %lu Hz\n", (cur._NAME_ - ctx->old._NAME_)/RATE_PERIOD);
197 #define RATE_PERIOD 2
198 static void rate_callback(unsigned long arg)
200 struct rate_context * ctx = (struct rate_context *)arg;
201 struct rate_stats cur = ctx->new;
213 r = mod_timer(&ctx->timer, jiffies +
214 msecs_to_jiffies(RATE_PERIOD * 1000));
216 D("[v1000] Error: mod_timer()");
219 static struct rate_context rate_ctx;
226 /* =============== GENERIC NETMAP ADAPTER SUPPORT ================= */
227 #define GENERIC_BUF_SIZE netmap_buf_size /* Size of the mbufs in the Tx pool. */
230 * Wrapper used by the generic adapter layer to notify
231 * the poller threads. Differently from netmap_rx_irq(), we check
232 * only IFCAP_NETMAP instead of NAF_NATIVE_ON to enable the irq.
235 netmap_generic_irq(struct ifnet *ifp, u_int q, u_int *work_done)
237 if (unlikely(!(ifp->if_capenable & IFCAP_NETMAP)))
240 netmap_common_irq(ifp, q, work_done);
244 /* Enable/disable netmap mode for a generic network interface. */
246 generic_netmap_register(struct netmap_adapter *na, int enable)
248 struct ifnet *ifp = na->ifp;
249 struct netmap_generic_adapter *gna = (struct netmap_generic_adapter *)na;
258 error = ifp->netdev_ops->ndo_stop(ifp);
262 #endif /* REG_RESET */
264 if (enable) { /* Enable netmap mode. */
265 /* Init the mitigation support on all the rx queues. */
266 gna->mit = malloc(na->num_rx_rings * sizeof(struct nm_generic_mit),
267 M_DEVBUF, M_NOWAIT | M_ZERO);
269 D("mitigation allocation failed");
273 for (r=0; r<na->num_rx_rings; r++)
274 netmap_mitigation_init(&gna->mit[r], na);
276 /* Initialize the rx queue, as generic_rx_handler() can
277 * be called as soon as netmap_catch_rx() returns.
279 for (r=0; r<na->num_rx_rings; r++) {
280 mbq_safe_init(&na->rx_rings[r].rx_queue);
284 * Preallocate packet buffers for the tx rings.
286 for (r=0; r<na->num_tx_rings; r++)
287 na->tx_rings[r].tx_pool = NULL;
288 for (r=0; r<na->num_tx_rings; r++) {
289 na->tx_rings[r].tx_pool = malloc(na->num_tx_desc * sizeof(struct mbuf *),
290 M_DEVBUF, M_NOWAIT | M_ZERO);
291 if (!na->tx_rings[r].tx_pool) {
292 D("tx_pool allocation failed");
296 for (i=0; i<na->num_tx_desc; i++)
297 na->tx_rings[r].tx_pool[i] = NULL;
298 for (i=0; i<na->num_tx_desc; i++) {
299 m = netmap_get_mbuf(GENERIC_BUF_SIZE);
301 D("tx_pool[%d] allocation failed", i);
305 na->tx_rings[r].tx_pool[i] = m;
309 /* Prepare to intercept incoming traffic. */
310 error = netmap_catch_rx(na, 1);
312 D("netdev_rx_handler_register() failed (%d)", error);
313 goto register_handler;
315 ifp->if_capenable |= IFCAP_NETMAP;
317 /* Make netmap control the packet steering. */
318 netmap_catch_tx(gna, 1);
323 if (rate_ctx.refcount == 0) {
325 memset(&rate_ctx, 0, sizeof(rate_ctx));
326 setup_timer(&rate_ctx.timer, &rate_callback, (unsigned long)&rate_ctx);
327 if (mod_timer(&rate_ctx.timer, jiffies + msecs_to_jiffies(1500))) {
328 D("Error: mod_timer()");
334 } else if (na->tx_rings[0].tx_pool) {
335 /* Disable netmap mode. We enter here only if the previous
336 generic_netmap_register(na, 1) was successfull.
337 If it was not, na->tx_rings[0].tx_pool was set to NULL by the
338 error handling code below. */
341 ifp->if_capenable &= ~IFCAP_NETMAP;
343 /* Release packet steering control. */
344 netmap_catch_tx(gna, 0);
346 /* Do not intercept packets on the rx path. */
347 netmap_catch_rx(na, 0);
351 /* Free the mbufs going to the netmap rings */
352 for (r=0; r<na->num_rx_rings; r++) {
353 mbq_safe_purge(&na->rx_rings[r].rx_queue);
354 mbq_safe_destroy(&na->rx_rings[r].rx_queue);
357 for (r=0; r<na->num_rx_rings; r++)
358 netmap_mitigation_cleanup(&gna->mit[r]);
359 free(gna->mit, M_DEVBUF);
361 for (r=0; r<na->num_tx_rings; r++) {
362 for (i=0; i<na->num_tx_desc; i++) {
363 m_freem(na->tx_rings[r].tx_pool[i]);
365 free(na->tx_rings[r].tx_pool, M_DEVBUF);
369 if (--rate_ctx.refcount == 0) {
371 del_timer(&rate_ctx.timer);
377 error = ifp->netdev_ops->ndo_open(ifp);
388 for (r=0; r<na->num_tx_rings; r++) {
389 if (na->tx_rings[r].tx_pool == NULL)
391 for (i=0; i<na->num_tx_desc; i++)
392 if (na->tx_rings[r].tx_pool[i])
393 m_freem(na->tx_rings[r].tx_pool[i]);
394 free(na->tx_rings[r].tx_pool, M_DEVBUF);
395 na->tx_rings[r].tx_pool = NULL;
397 for (r=0; r<na->num_rx_rings; r++) {
398 netmap_mitigation_cleanup(&gna->mit[r]);
399 mbq_safe_destroy(&na->rx_rings[r].rx_queue);
401 free(gna->mit, M_DEVBUF);
408 * Callback invoked when the device driver frees an mbuf used
409 * by netmap to transmit a packet. This usually happens when
410 * the NIC notifies the driver that transmission is completed.
413 generic_mbuf_destructor(struct mbuf *m)
415 netmap_generic_irq(MBUF_IFP(m), MBUF_TXQ(m), NULL);
418 RD(5, "Tx irq (%p) queue %d index %d" , m, MBUF_TXQ(m), (int)(uintptr_t)m->m_ext.ext_arg1);
419 netmap_default_mbuf_destructor(m);
420 #endif /* __FreeBSD__ */
421 IFRATE(rate_ctx.new.txirq++);
424 /* Record completed transmissions and update hwtail.
426 * The oldest tx buffer not yet completed is at nr_hwtail + 1,
427 * nr_hwcur is the first unsent buffer.
430 generic_netmap_tx_clean(struct netmap_kring *kring)
432 u_int const lim = kring->nkr_num_slots - 1;
433 u_int nm_i = nm_next(kring->nr_hwtail, lim);
434 u_int hwcur = kring->nr_hwcur;
436 struct mbuf **tx_pool = kring->tx_pool;
438 while (nm_i != hwcur) { /* buffers not completed */
439 struct mbuf *m = tx_pool[nm_i];
441 if (unlikely(m == NULL)) {
442 /* this is done, try to replenish the entry */
443 tx_pool[nm_i] = m = netmap_get_mbuf(GENERIC_BUF_SIZE);
444 if (unlikely(m == NULL)) {
445 D("mbuf allocation failed, XXX error");
446 // XXX how do we proceed ? break ?
449 } else if (GET_MBUF_REFCNT(m) != 1) {
450 break; /* This mbuf is still busy: its refcnt is 2. */
453 nm_i = nm_next(nm_i, lim);
455 kring->nr_hwtail = nm_prev(nm_i, lim);
456 ND("tx completed [%d] -> hwtail %d", n, kring->nr_hwtail);
463 * We have pending packets in the driver between nr_hwtail +1 and hwcur.
464 * Compute a position in the middle, to be used to generate
468 generic_tx_event_middle(struct netmap_kring *kring, u_int hwcur)
470 u_int n = kring->nkr_num_slots;
471 u_int ntc = nm_next(kring->nr_hwtail, n-1);
475 e = (hwcur + ntc) / 2;
476 } else { /* wrap around */
477 e = (hwcur + n + ntc) / 2;
483 if (unlikely(e >= n)) {
484 D("This cannot happen");
492 * We have pending packets in the driver between nr_hwtail+1 and hwcur.
493 * Schedule a notification approximately in the middle of the two.
494 * There is a race but this is only called within txsync which does
498 generic_set_tx_event(struct netmap_kring *kring, u_int hwcur)
503 if (nm_next(kring->nr_hwtail, kring->nkr_num_slots -1) == hwcur) {
504 return; /* all buffers are free */
506 e = generic_tx_event_middle(kring, hwcur);
508 m = kring->tx_pool[e];
509 ND(5, "Request Event at %d mbuf %p refcnt %d", e, m, m ? GET_MBUF_REFCNT(m) : -2 );
511 /* This can happen if there is already an event on the netmap
512 slot 'e': There is nothing to do. */
515 kring->tx_pool[e] = NULL;
516 SET_MBUF_DESTRUCTOR(m, generic_mbuf_destructor);
519 /* Decrement the refcount an free it if we have the last one. */
526 * generic_netmap_txsync() transforms netmap buffers into mbufs
527 * and passes them to the standard device driver
528 * (ndo_start_xmit() or ifp->if_transmit() ).
529 * On linux this is not done directly, but using dev_queue_xmit(),
530 * since it implements the TX flow control (and takes some locks).
533 generic_netmap_txsync(struct netmap_adapter *na, u_int ring_nr, int flags)
535 struct ifnet *ifp = na->ifp;
536 struct netmap_kring *kring = &na->tx_rings[ring_nr];
537 struct netmap_ring *ring = kring->ring;
538 u_int nm_i; /* index into the netmap ring */ // j
539 u_int const lim = kring->nkr_num_slots - 1;
540 u_int const head = kring->rhead;
542 IFRATE(rate_ctx.new.txsync++);
544 // TODO: handle the case of mbuf allocation failure
549 * First part: process new packets to send.
551 nm_i = kring->nr_hwcur;
552 if (nm_i != head) { /* we have new packets to send */
553 while (nm_i != head) {
554 struct netmap_slot *slot = &ring->slot[nm_i];
555 u_int len = slot->len;
556 void *addr = NMB(slot);
558 /* device-specific */
562 NM_CHECK_ADDR_LEN(addr, len);
564 /* Tale a mbuf from the tx pool and copy in the user packet. */
565 m = kring->tx_pool[nm_i];
567 RD(5, "This should never happen");
568 kring->tx_pool[nm_i] = m = netmap_get_mbuf(GENERIC_BUF_SIZE);
569 if (unlikely(m == NULL)) {
570 D("mbuf allocation failed");
574 /* XXX we should ask notifications when NS_REPORT is set,
575 * or roughly every half frame. We can optimize this
576 * by lazily requesting notifications only when a
577 * transmission fails. Probably the best way is to
578 * break on failures and set notifications when
579 * ring->cur == ring->tail || nm_i != cur
581 tx_ret = generic_xmit_frame(ifp, m, addr, len, ring_nr);
582 if (unlikely(tx_ret)) {
583 RD(5, "start_xmit failed: err %d [nm_i %u, head %u, hwtail %u]",
584 tx_ret, nm_i, head, kring->nr_hwtail);
586 * No room for this mbuf in the device driver.
587 * Request a notification FOR A PREVIOUS MBUF,
588 * then call generic_netmap_tx_clean(kring) to do the
589 * double check and see if we can free more buffers.
590 * If there is space continue, else break;
591 * NOTE: the double check is necessary if the problem
592 * occurs in the txsync call after selrecord().
593 * Also, we need some way to tell the caller that not
594 * all buffers were queued onto the device (this was
595 * not a problem with native netmap driver where space
596 * is preallocated). The bridge has a similar problem
597 * and we solve it there by dropping the excess packets.
599 generic_set_tx_event(kring, nm_i);
600 if (generic_netmap_tx_clean(kring)) { /* space now available */
606 slot->flags &= ~(NS_REPORT | NS_BUF_CHANGED);
607 nm_i = nm_next(nm_i, lim);
608 IFRATE(rate_ctx.new.txpkt ++);
611 /* Update hwcur to the next slot to transmit. */
612 kring->nr_hwcur = nm_i; /* not head, we could break early */
616 * Second, reclaim completed buffers
618 if (flags & NAF_FORCE_RECLAIM || nm_kr_txempty(kring)) {
619 /* No more available slots? Set a notification event
620 * on a netmap slot that will be cleaned in the future.
621 * No doublecheck is performed, since txsync() will be
622 * called twice by netmap_poll().
624 generic_set_tx_event(kring, nm_i);
626 ND("tx #%d, hwtail = %d", n, kring->nr_hwtail);
628 generic_netmap_tx_clean(kring);
630 nm_txsync_finalize(kring);
637 * This handler is registered (through netmap_catch_rx())
638 * within the attached network interface
639 * in the RX subsystem, so that every mbuf passed up by
640 * the driver can be stolen to the network stack.
641 * Stolen packets are put in a queue where the
642 * generic_netmap_rxsync() callback can extract them.
645 generic_rx_handler(struct ifnet *ifp, struct mbuf *m)
647 struct netmap_adapter *na = NA(ifp);
648 struct netmap_generic_adapter *gna = (struct netmap_generic_adapter *)na;
650 u_int rr = MBUF_RXQ(m); // receive ring number
652 if (rr >= na->num_rx_rings) {
653 rr = rr % na->num_rx_rings; // XXX expensive...
656 /* limit the size of the queue */
657 if (unlikely(mbq_len(&na->rx_rings[rr].rx_queue) > 1024)) {
660 mbq_safe_enqueue(&na->rx_rings[rr].rx_queue, m);
663 if (netmap_generic_mit < 32768) {
664 /* no rx mitigation, pass notification up */
665 netmap_generic_irq(na->ifp, rr, &work_done);
666 IFRATE(rate_ctx.new.rxirq++);
668 /* same as send combining, filter notification if there is a
669 * pending timer, otherwise pass it up and start a timer.
671 if (likely(netmap_mitigation_active(&gna->mit[rr]))) {
672 /* Record that there is some pending work. */
673 gna->mit[rr].mit_pending = 1;
675 netmap_generic_irq(na->ifp, rr, &work_done);
676 IFRATE(rate_ctx.new.rxirq++);
677 netmap_mitigation_start(&gna->mit[rr]);
683 * generic_netmap_rxsync() extracts mbufs from the queue filled by
684 * generic_netmap_rx_handler() and puts their content in the netmap
686 * Access must be protected because the rx handler is asynchronous,
689 generic_netmap_rxsync(struct netmap_adapter *na, u_int ring_nr, int flags)
691 struct netmap_kring *kring = &na->rx_rings[ring_nr];
692 struct netmap_ring *ring = kring->ring;
693 u_int nm_i; /* index into the netmap ring */ //j,
695 u_int const lim = kring->nkr_num_slots - 1;
696 u_int const head = nm_rxsync_prologue(kring);
697 int force_update = (flags & NAF_FORCE_READ) || kring->nr_kflags & NKR_PENDINTR;
700 return netmap_ring_reinit(kring);
703 * First part: import newly received packets.
705 if (netmap_no_pendintr || force_update) {
706 /* extract buffers from the rx queue, stop at most one
707 * slot before nr_hwcur (stop_i)
709 uint16_t slot_flags = kring->nkr_slot_flags;
710 u_int stop_i = nm_prev(kring->nr_hwcur, lim);
712 nm_i = kring->nr_hwtail; /* first empty slot in the receive ring */
713 for (n = 0; nm_i != stop_i; n++) {
715 void *addr = NMB(&ring->slot[nm_i]);
718 /* we only check the address here on generic rx rings */
719 if (addr == netmap_buffer_base) { /* Bad buffer */
720 return netmap_ring_reinit(kring);
723 * Call the locked version of the function.
724 * XXX Ideally we could grab a batch of mbufs at once
725 * and save some locking overhead.
727 m = mbq_safe_dequeue(&kring->rx_queue);
728 if (!m) /* no more data */
731 m_copydata(m, 0, len, addr);
732 ring->slot[nm_i].len = len;
733 ring->slot[nm_i].flags = slot_flags;
735 nm_i = nm_next(nm_i, lim);
738 kring->nr_hwtail = nm_i;
739 IFRATE(rate_ctx.new.rxpkt += n);
741 kring->nr_kflags &= ~NKR_PENDINTR;
744 // XXX should we invert the order ?
746 * Second part: skip past packets that userspace has released.
748 nm_i = kring->nr_hwcur;
750 /* Userspace has released some packets. */
751 for (n = 0; nm_i != head; n++) {
752 struct netmap_slot *slot = &ring->slot[nm_i];
754 slot->flags &= ~NS_BUF_CHANGED;
755 nm_i = nm_next(nm_i, lim);
757 kring->nr_hwcur = head;
759 /* tell userspace that there might be new packets. */
760 nm_rxsync_finalize(kring);
761 IFRATE(rate_ctx.new.rxsync++);
767 generic_netmap_dtor(struct netmap_adapter *na)
769 struct ifnet *ifp = na->ifp;
770 struct netmap_generic_adapter *gna = (struct netmap_generic_adapter*)na;
771 struct netmap_adapter *prev_na = gna->prev;
773 if (prev_na != NULL) {
774 D("Released generic NA %p", gna);
776 netmap_adapter_put(prev_na);
780 D("Restored native NA %p", prev_na);
786 * generic_netmap_attach() makes it possible to use netmap on
787 * a device without native netmap support.
788 * This is less performant than native support but potentially
789 * faster than raw sockets or similar schemes.
791 * In this "emulated" mode, netmap rings do not necessarily
792 * have the same size as those in the NIC. We use a default
793 * value and possibly override it if the OS has ways to fetch the
794 * actual configuration.
797 generic_netmap_attach(struct ifnet *ifp)
799 struct netmap_adapter *na;
800 struct netmap_generic_adapter *gna;
802 u_int num_tx_desc, num_rx_desc;
804 num_tx_desc = num_rx_desc = netmap_generic_ringsize; /* starting point */
806 generic_find_num_desc(ifp, &num_tx_desc, &num_rx_desc);
807 ND("Netmap ring size: TX = %d, RX = %d", num_tx_desc, num_rx_desc);
808 if (num_tx_desc == 0 || num_rx_desc == 0) {
809 D("Device has no hw slots (tx %u, rx %u)", num_tx_desc, num_rx_desc);
813 gna = malloc(sizeof(*gna), M_DEVBUF, M_NOWAIT | M_ZERO);
815 D("no memory on attach, give up");
818 na = (struct netmap_adapter *)gna;
820 na->num_tx_desc = num_tx_desc;
821 na->num_rx_desc = num_rx_desc;
822 na->nm_register = &generic_netmap_register;
823 na->nm_txsync = &generic_netmap_txsync;
824 na->nm_rxsync = &generic_netmap_rxsync;
825 na->nm_dtor = &generic_netmap_dtor;
826 /* when using generic, IFCAP_NETMAP is set so we force
827 * NAF_SKIP_INTR to use the regular interrupt handler
829 na->na_flags = NAF_SKIP_INTR | NAF_HOST_RINGS;
831 ND("[GNA] num_tx_queues(%d), real_num_tx_queues(%d), len(%lu)",
832 ifp->num_tx_queues, ifp->real_num_tx_queues,
834 ND("[GNA] num_rx_queues(%d), real_num_rx_queues(%d)",
835 ifp->num_rx_queues, ifp->real_num_rx_queues);
837 generic_find_num_queues(ifp, &na->num_tx_rings, &na->num_rx_rings);
839 retval = netmap_attach_common(na);