1 /*-
2 * Copyright (c) 2004-2006 Kip Macy
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD$");
29
30 #include "opt_inet.h"
31 #include "opt_inet6.h"
32
33 #include <sys/param.h>
34 #include <sys/sockio.h>
35 #include <sys/limits.h>
36 #include <sys/mbuf.h>
37 #include <sys/malloc.h>
38 #include <sys/module.h>
39 #include <sys/kernel.h>
40 #include <sys/socket.h>
41 #include <sys/sysctl.h>
42
43 #include <net/if.h>
44 #include <net/if_var.h>
45 #include <net/if_arp.h>
46 #include <net/ethernet.h>
47 #include <net/if_media.h>
48
49 #include <net/bpf.h>
50
51 #include <net/if_types.h>
52
53 #include <netinet/in.h>
54 #include <netinet/ip.h>
55 #include <netinet/if_ether.h>
56 #include <netinet/tcp.h>
57 #include <netinet/tcp_lro.h>
58
59 #include <vm/vm.h>
60 #include <vm/pmap.h>
61
62 #include <sys/bus.h>
63
64 #include <xen/xen-os.h>
65 #include <xen/hypervisor.h>
66 #include <xen/xen_intr.h>
67 #include <xen/gnttab.h>
68 #include <xen/interface/memory.h>
69 #include <xen/interface/io/netif.h>
70 #include <xen/xenbus/xenbusvar.h>
71
72 #include "xenbus_if.h"
73
74 /* Features supported by all backends. TSO and LRO can be negotiated */
75 #define XN_CSUM_FEATURES (CSUM_TCP | CSUM_UDP)
76
77 #define NET_TX_RING_SIZE __RING_SIZE((netif_tx_sring_t *)0, PAGE_SIZE)
78 #define NET_RX_RING_SIZE __RING_SIZE((netif_rx_sring_t *)0, PAGE_SIZE)
79
80 /*
81 * Should the driver do LRO on the RX end
82 * this can be toggled on the fly, but the
83 * interface must be reset (down/up) for it
84 * to take effect.
85 */
86 static int xn_enable_lro = 1;
87 TUNABLE_INT("hw.xn.enable_lro", &xn_enable_lro);
88
89 /**
90 * \brief The maximum allowed data fragments in a single transmit
91 * request.
92 *
93 * This limit is imposed by the backend driver. We assume here that
94 * we are dealing with a Linux driver domain and have set our limit
95 * to mirror the Linux MAX_SKB_FRAGS constant.
96 */
97 #define MAX_TX_REQ_FRAGS (65536 / PAGE_SIZE + 2)
98
99 #define RX_COPY_THRESHOLD 256
100
101 #define net_ratelimit() 0
102
103 struct netfront_info;
104 struct netfront_rx_info;
105
106 static void xn_txeof(struct netfront_info *);
107 static void xn_rxeof(struct netfront_info *);
108 static void network_alloc_rx_buffers(struct netfront_info *);
109
110 static void xn_tick_locked(struct netfront_info *);
111 static void xn_tick(void *);
112
113 static void xn_intr(void *);
114 static inline int xn_count_frags(struct mbuf *m);
115 static int xn_assemble_tx_request(struct netfront_info *sc,
116 struct mbuf *m_head);
117 static void xn_start_locked(struct ifnet *);
118 static void xn_start(struct ifnet *);
119 static int xn_ioctl(struct ifnet *, u_long, caddr_t);
120 static void xn_ifinit_locked(struct netfront_info *);
121 static void xn_ifinit(void *);
122 static void xn_stop(struct netfront_info *);
123 static void xn_query_features(struct netfront_info *np);
124 static int xn_configure_features(struct netfront_info *np);
125 #ifdef notyet
126 static void xn_watchdog(struct ifnet *);
127 #endif
128
129 #ifdef notyet
130 static void netfront_closing(device_t dev);
131 #endif
132 static void netif_free(struct netfront_info *info);
133 static int netfront_detach(device_t dev);
134
135 static int talk_to_backend(device_t dev, struct netfront_info *info);
136 static int create_netdev(device_t dev);
137 static void netif_disconnect_backend(struct netfront_info *info);
138 static int setup_device(device_t dev, struct netfront_info *info);
139 static void free_ring(int *ref, void *ring_ptr_ref);
140
141 static int xn_ifmedia_upd(struct ifnet *ifp);
142 static void xn_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr);
143
144 /* Xenolinux helper functions */
145 int network_connect(struct netfront_info *);
146
147 static void xn_free_rx_ring(struct netfront_info *);
148
149 static void xn_free_tx_ring(struct netfront_info *);
150
151 static int xennet_get_responses(struct netfront_info *np,
152 struct netfront_rx_info *rinfo, RING_IDX rp, RING_IDX *cons,
153 struct mbuf **list);
154
155 #define virt_to_mfn(x) (vtophys(x) >> PAGE_SHIFT)
156
157 #define INVALID_P2M_ENTRY (~0UL)
158
159 /*
160 * Mbuf pointers. We need these to keep track of the virtual addresses
161 * of our mbuf chains since we can only convert from virtual to physical,
162 * not the other way around. The size must track the free index arrays.
163 */
164 struct xn_chain_data {
165 struct mbuf *xn_tx_chain[NET_TX_RING_SIZE+1];
166 int xn_tx_chain_cnt;
167 struct mbuf *xn_rx_chain[NET_RX_RING_SIZE+1];
168 };
169
170 struct netfront_stats
171 {
172 u_long rx_packets; /* total packets received */
173 u_long tx_packets; /* total packets transmitted */
174 u_long rx_bytes; /* total bytes received */
175 u_long tx_bytes; /* total bytes transmitted */
176 u_long rx_errors; /* bad packets received */
177 u_long tx_errors; /* packet transmit problems */
178 };
179
180 struct netfront_info {
181 struct ifnet *xn_ifp;
182 struct lro_ctrl xn_lro;
183
184 struct netfront_stats stats;
185 u_int tx_full;
186
187 netif_tx_front_ring_t tx;
188 netif_rx_front_ring_t rx;
189
190 struct mtx tx_lock;
191 struct mtx rx_lock;
192 struct mtx sc_lock;
193
194 xen_intr_handle_t xen_intr_handle;
195 u_int carrier;
196 u_int maxfrags;
197
198 /* Receive-ring batched refills. */
199 #define RX_MIN_TARGET 32
200 #define RX_MAX_TARGET NET_RX_RING_SIZE
201 int rx_min_target;
202 int rx_max_target;
203 int rx_target;
204
205 grant_ref_t gref_tx_head;
206 grant_ref_t grant_tx_ref[NET_TX_RING_SIZE + 1];
207 grant_ref_t gref_rx_head;
208 grant_ref_t grant_rx_ref[NET_TX_RING_SIZE + 1];
209
210 device_t xbdev;
211 int tx_ring_ref;
212 int rx_ring_ref;
213 uint8_t mac[ETHER_ADDR_LEN];
214 struct xn_chain_data xn_cdata; /* mbufs */
215 struct mbufq xn_rx_batch; /* batch queue */
216
217 int xn_if_flags;
218 struct callout xn_stat_ch;
219
220 xen_pfn_t rx_pfn_array[NET_RX_RING_SIZE];
221 struct ifmedia sc_media;
222
223 bool xn_resume;
224 };
225
226 #define rx_mbufs xn_cdata.xn_rx_chain
227 #define tx_mbufs xn_cdata.xn_tx_chain
228
229 #define XN_RX_LOCK(_sc) mtx_lock(&(_sc)->rx_lock)
230 #define XN_RX_UNLOCK(_sc) mtx_unlock(&(_sc)->rx_lock)
231
232 #define XN_TX_LOCK(_sc) mtx_lock(&(_sc)->tx_lock)
233 #define XN_TX_UNLOCK(_sc) mtx_unlock(&(_sc)->tx_lock)
234
235 #define XN_LOCK(_sc) mtx_lock(&(_sc)->sc_lock);
236 #define XN_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_lock);
237
238 #define XN_LOCK_ASSERT(_sc) mtx_assert(&(_sc)->sc_lock, MA_OWNED);
239 #define XN_RX_LOCK_ASSERT(_sc) mtx_assert(&(_sc)->rx_lock, MA_OWNED);
240 #define XN_TX_LOCK_ASSERT(_sc) mtx_assert(&(_sc)->tx_lock, MA_OWNED);
241
242 struct netfront_rx_info {
243 struct netif_rx_response rx;
244 struct netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
245 };
246
247 #define netfront_carrier_on(netif) ((netif)->carrier = 1)
248 #define netfront_carrier_off(netif) ((netif)->carrier = 0)
249 #define netfront_carrier_ok(netif) ((netif)->carrier)
250
251 /* Access macros for acquiring freeing slots in xn_free_{tx,rx}_idxs[]. */
252
253 static inline void
add_id_to_freelist(struct mbuf ** list,uintptr_t id)254 add_id_to_freelist(struct mbuf **list, uintptr_t id)
255 {
256 KASSERT(id != 0,
257 ("%s: the head item (0) must always be free.", __func__));
258 list[id] = list[0];
259 list[0] = (struct mbuf *)id;
260 }
261
262 static inline unsigned short
get_id_from_freelist(struct mbuf ** list)263 get_id_from_freelist(struct mbuf **list)
264 {
265 uintptr_t id;
266
267 id = (uintptr_t)list[0];
268 KASSERT(id != 0,
269 ("%s: the head item (0) must always remain free.", __func__));
270 list[0] = list[id];
271 return (id);
272 }
273
274 static inline int
xennet_rxidx(RING_IDX idx)275 xennet_rxidx(RING_IDX idx)
276 {
277 return idx & (NET_RX_RING_SIZE - 1);
278 }
279
280 static inline struct mbuf *
xennet_get_rx_mbuf(struct netfront_info * np,RING_IDX ri)281 xennet_get_rx_mbuf(struct netfront_info *np, RING_IDX ri)
282 {
283 int i = xennet_rxidx(ri);
284 struct mbuf *m;
285
286 m = np->rx_mbufs[i];
287 np->rx_mbufs[i] = NULL;
288 return (m);
289 }
290
291 static inline grant_ref_t
xennet_get_rx_ref(struct netfront_info * np,RING_IDX ri)292 xennet_get_rx_ref(struct netfront_info *np, RING_IDX ri)
293 {
294 int i = xennet_rxidx(ri);
295 grant_ref_t ref = np->grant_rx_ref[i];
296 KASSERT(ref != GRANT_REF_INVALID, ("Invalid grant reference!\n"));
297 np->grant_rx_ref[i] = GRANT_REF_INVALID;
298 return ref;
299 }
300
301 #define IPRINTK(fmt, args...) \
302 printf("[XEN] " fmt, ##args)
303 #ifdef INVARIANTS
304 #define WPRINTK(fmt, args...) \
305 printf("[XEN] " fmt, ##args)
306 #else
307 #define WPRINTK(fmt, args...)
308 #endif
309 #ifdef DEBUG
310 #define DPRINTK(fmt, args...) \
311 printf("[XEN] %s: " fmt, __func__, ##args)
312 #else
313 #define DPRINTK(fmt, args...)
314 #endif
315
316 /**
317 * Read the 'mac' node at the given device's node in the store, and parse that
318 * as colon-separated octets, placing result the given mac array. mac must be
319 * a preallocated array of length ETH_ALEN (as declared in linux/if_ether.h).
320 * Return 0 on success, or errno on error.
321 */
322 static int
xen_net_read_mac(device_t dev,uint8_t mac[])323 xen_net_read_mac(device_t dev, uint8_t mac[])
324 {
325 int error, i;
326 char *s, *e, *macstr;
327 const char *path;
328
329 path = xenbus_get_node(dev);
330 error = xs_read(XST_NIL, path, "mac", NULL, (void **) &macstr);
331 if (error == ENOENT) {
332 /*
333 * Deal with missing mac XenStore nodes on devices with
334 * HVM emulation (the 'ioemu' configuration attribute)
335 * enabled.
336 *
337 * The HVM emulator may execute in a stub device model
338 * domain which lacks the permission, only given to Dom0,
339 * to update the guest's XenStore tree. For this reason,
340 * the HVM emulator doesn't even attempt to write the
341 * front-side mac node, even when operating in Dom0.
342 * However, there should always be a mac listed in the
343 * backend tree. Fallback to this version if our query
344 * of the front side XenStore location doesn't find
345 * anything.
346 */
347 path = xenbus_get_otherend_path(dev);
348 error = xs_read(XST_NIL, path, "mac", NULL, (void **) &macstr);
349 }
350 if (error != 0) {
351 xenbus_dev_fatal(dev, error, "parsing %s/mac", path);
352 return (error);
353 }
354
355 s = macstr;
356 for (i = 0; i < ETHER_ADDR_LEN; i++) {
357 mac[i] = strtoul(s, &e, 16);
358 if (s == e || (e[0] != ':' && e[0] != 0)) {
359 free(macstr, M_XENBUS);
360 return (ENOENT);
361 }
362 s = &e[1];
363 }
364 free(macstr, M_XENBUS);
365 return (0);
366 }
367
368 /**
369 * Entry point to this code when a new device is created. Allocate the basic
370 * structures and the ring buffers for communication with the backend, and
371 * inform the backend of the appropriate details for those. Switch to
372 * Connected state.
373 */
374 static int
netfront_probe(device_t dev)375 netfront_probe(device_t dev)
376 {
377
378 if (xen_hvm_domain() && xen_disable_pv_nics != 0)
379 return (ENXIO);
380
381 if (!strcmp(xenbus_get_type(dev), "vif")) {
382 device_set_desc(dev, "Virtual Network Interface");
383 return (0);
384 }
385
386 return (ENXIO);
387 }
388
389 static int
netfront_attach(device_t dev)390 netfront_attach(device_t dev)
391 {
392 int err;
393
394 err = create_netdev(dev);
395 if (err) {
396 xenbus_dev_fatal(dev, err, "creating netdev");
397 return (err);
398 }
399
400 SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
401 SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
402 OID_AUTO, "enable_lro", CTLFLAG_RW,
403 &xn_enable_lro, 0, "Large Receive Offload");
404
405 return (0);
406 }
407
408 static int
netfront_suspend(device_t dev)409 netfront_suspend(device_t dev)
410 {
411 struct netfront_info *info = device_get_softc(dev);
412
413 XN_RX_LOCK(info);
414 XN_TX_LOCK(info);
415 netfront_carrier_off(info);
416 XN_TX_UNLOCK(info);
417 XN_RX_UNLOCK(info);
418 return (0);
419 }
420
421 /**
422 * We are reconnecting to the backend, due to a suspend/resume, or a backend
423 * driver restart. We tear down our netif structure and recreate it, but
424 * leave the device-layer structures intact so that this is transparent to the
425 * rest of the kernel.
426 */
427 static int
netfront_resume(device_t dev)428 netfront_resume(device_t dev)
429 {
430 struct netfront_info *info = device_get_softc(dev);
431
432 info->xn_resume = true;
433 netif_disconnect_backend(info);
434 return (0);
435 }
436
437 /* Common code used when first setting up, and when resuming. */
438 static int
talk_to_backend(device_t dev,struct netfront_info * info)439 talk_to_backend(device_t dev, struct netfront_info *info)
440 {
441 const char *message;
442 struct xs_transaction xst;
443 const char *node = xenbus_get_node(dev);
444 int err;
445
446 err = xen_net_read_mac(dev, info->mac);
447 if (err) {
448 xenbus_dev_fatal(dev, err, "parsing %s/mac", node);
449 goto out;
450 }
451
452 /* Create shared ring, alloc event channel. */
453 err = setup_device(dev, info);
454 if (err)
455 goto out;
456
457 again:
458 err = xs_transaction_start(&xst);
459 if (err) {
460 xenbus_dev_fatal(dev, err, "starting transaction");
461 goto destroy_ring;
462 }
463 err = xs_printf(xst, node, "tx-ring-ref","%u",
464 info->tx_ring_ref);
465 if (err) {
466 message = "writing tx ring-ref";
467 goto abort_transaction;
468 }
469 err = xs_printf(xst, node, "rx-ring-ref","%u",
470 info->rx_ring_ref);
471 if (err) {
472 message = "writing rx ring-ref";
473 goto abort_transaction;
474 }
475 err = xs_printf(xst, node,
476 "event-channel", "%u",
477 xen_intr_port(info->xen_intr_handle));
478 if (err) {
479 message = "writing event-channel";
480 goto abort_transaction;
481 }
482 err = xs_printf(xst, node, "request-rx-copy", "%u", 1);
483 if (err) {
484 message = "writing request-rx-copy";
485 goto abort_transaction;
486 }
487 err = xs_printf(xst, node, "feature-rx-notify", "%d", 1);
488 if (err) {
489 message = "writing feature-rx-notify";
490 goto abort_transaction;
491 }
492 err = xs_printf(xst, node, "feature-sg", "%d", 1);
493 if (err) {
494 message = "writing feature-sg";
495 goto abort_transaction;
496 }
497 err = xs_printf(xst, node, "feature-gso-tcpv4", "%d", 1);
498 if (err) {
499 message = "writing feature-gso-tcpv4";
500 goto abort_transaction;
501 }
502
503 err = xs_transaction_end(xst, 0);
504 if (err) {
505 if (err == EAGAIN)
506 goto again;
507 xenbus_dev_fatal(dev, err, "completing transaction");
508 goto destroy_ring;
509 }
510
511 return 0;
512
513 abort_transaction:
514 xs_transaction_end(xst, 1);
515 xenbus_dev_fatal(dev, err, "%s", message);
516 destroy_ring:
517 netif_free(info);
518 out:
519 return err;
520 }
521
522 static int
setup_device(device_t dev,struct netfront_info * info)523 setup_device(device_t dev, struct netfront_info *info)
524 {
525 netif_tx_sring_t *txs;
526 netif_rx_sring_t *rxs;
527 int error;
528
529 info->tx_ring_ref = GRANT_REF_INVALID;
530 info->rx_ring_ref = GRANT_REF_INVALID;
531 info->rx.sring = NULL;
532 info->tx.sring = NULL;
533
534 txs = (netif_tx_sring_t *)malloc(PAGE_SIZE, M_DEVBUF, M_NOWAIT|M_ZERO);
535 if (!txs) {
536 error = ENOMEM;
537 xenbus_dev_fatal(dev, error, "allocating tx ring page");
538 goto fail;
539 }
540 SHARED_RING_INIT(txs);
541 FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
542 error = xenbus_grant_ring(dev, virt_to_mfn(txs), &info->tx_ring_ref);
543 if (error)
544 goto fail;
545
546 rxs = (netif_rx_sring_t *)malloc(PAGE_SIZE, M_DEVBUF, M_NOWAIT|M_ZERO);
547 if (!rxs) {
548 error = ENOMEM;
549 xenbus_dev_fatal(dev, error, "allocating rx ring page");
550 goto fail;
551 }
552 SHARED_RING_INIT(rxs);
553 FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
554
555 error = xenbus_grant_ring(dev, virt_to_mfn(rxs), &info->rx_ring_ref);
556 if (error)
557 goto fail;
558
559 error = xen_intr_alloc_and_bind_local_port(dev,
560 xenbus_get_otherend_id(dev), /*filter*/NULL, xn_intr, info,
561 INTR_TYPE_NET | INTR_MPSAFE | INTR_ENTROPY, &info->xen_intr_handle);
562
563 if (error) {
564 xenbus_dev_fatal(dev, error,
565 "xen_intr_alloc_and_bind_local_port failed");
566 goto fail;
567 }
568
569 return (0);
570
571 fail:
572 netif_free(info);
573 return (error);
574 }
575
576 #ifdef INET
577 /**
578 * If this interface has an ipv4 address, send an arp for it. This
579 * helps to get the network going again after migrating hosts.
580 */
581 static void
netfront_send_fake_arp(device_t dev,struct netfront_info * info)582 netfront_send_fake_arp(device_t dev, struct netfront_info *info)
583 {
584 struct ifnet *ifp;
585 struct ifaddr *ifa;
586
587 ifp = info->xn_ifp;
588 TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
589 if (ifa->ifa_addr->sa_family == AF_INET) {
590 arp_ifinit(ifp, ifa);
591 }
592 }
593 }
594 #endif
595
596 /**
597 * Callback received when the backend's state changes.
598 */
599 static void
netfront_backend_changed(device_t dev,XenbusState newstate)600 netfront_backend_changed(device_t dev, XenbusState newstate)
601 {
602 struct netfront_info *sc = device_get_softc(dev);
603
604 DPRINTK("newstate=%d\n", newstate);
605
606 switch (newstate) {
607 case XenbusStateInitialising:
608 case XenbusStateInitialised:
609 case XenbusStateUnknown:
610 case XenbusStateClosed:
611 case XenbusStateReconfigured:
612 case XenbusStateReconfiguring:
613 break;
614 case XenbusStateInitWait:
615 if (xenbus_get_state(dev) != XenbusStateInitialising)
616 break;
617 if (network_connect(sc) != 0)
618 break;
619 xenbus_set_state(dev, XenbusStateConnected);
620 break;
621 case XenbusStateClosing:
622 xenbus_set_state(dev, XenbusStateClosed);
623 break;
624 case XenbusStateConnected:
625 #ifdef INET
626 netfront_send_fake_arp(dev, sc);
627 #endif
628 break;
629 }
630 }
631
632 static void
xn_free_rx_ring(struct netfront_info * sc)633 xn_free_rx_ring(struct netfront_info *sc)
634 {
635 #if 0
636 int i;
637
638 for (i = 0; i < NET_RX_RING_SIZE; i++) {
639 if (sc->xn_cdata.rx_mbufs[i] != NULL) {
640 m_freem(sc->rx_mbufs[i]);
641 sc->rx_mbufs[i] = NULL;
642 }
643 }
644
645 sc->rx.rsp_cons = 0;
646 sc->xn_rx_if->req_prod = 0;
647 sc->xn_rx_if->event = sc->rx.rsp_cons ;
648 #endif
649 }
650
651 static void
xn_free_tx_ring(struct netfront_info * sc)652 xn_free_tx_ring(struct netfront_info *sc)
653 {
654 #if 0
655 int i;
656
657 for (i = 0; i < NET_TX_RING_SIZE; i++) {
658 if (sc->tx_mbufs[i] != NULL) {
659 m_freem(sc->tx_mbufs[i]);
660 sc->xn_cdata.xn_tx_chain[i] = NULL;
661 }
662 }
663
664 return;
665 #endif
666 }
667
668 /**
669 * \brief Verify that there is sufficient space in the Tx ring
670 * buffer for a maximally sized request to be enqueued.
671 *
672 * A transmit request requires a transmit descriptor for each packet
673 * fragment, plus up to 2 entries for "options" (e.g. TSO).
674 */
675 static inline int
xn_tx_slot_available(struct netfront_info * np)676 xn_tx_slot_available(struct netfront_info *np)
677 {
678 return (RING_FREE_REQUESTS(&np->tx) > (MAX_TX_REQ_FRAGS + 2));
679 }
680
681 static void
netif_release_tx_bufs(struct netfront_info * np)682 netif_release_tx_bufs(struct netfront_info *np)
683 {
684 int i;
685
686 for (i = 1; i <= NET_TX_RING_SIZE; i++) {
687 struct mbuf *m;
688
689 m = np->tx_mbufs[i];
690
691 /*
692 * We assume that no kernel addresses are
693 * less than NET_TX_RING_SIZE. Any entry
694 * in the table that is below this number
695 * must be an index from free-list tracking.
696 */
697 if (((uintptr_t)m) <= NET_TX_RING_SIZE)
698 continue;
699 gnttab_end_foreign_access_ref(np->grant_tx_ref[i]);
700 gnttab_release_grant_reference(&np->gref_tx_head,
701 np->grant_tx_ref[i]);
702 np->grant_tx_ref[i] = GRANT_REF_INVALID;
703 add_id_to_freelist(np->tx_mbufs, i);
704 np->xn_cdata.xn_tx_chain_cnt--;
705 if (np->xn_cdata.xn_tx_chain_cnt < 0) {
706 panic("%s: tx_chain_cnt must be >= 0", __func__);
707 }
708 m_free(m);
709 }
710 }
711
712 static void
network_alloc_rx_buffers(struct netfront_info * sc)713 network_alloc_rx_buffers(struct netfront_info *sc)
714 {
715 int otherend_id = xenbus_get_otherend_id(sc->xbdev);
716 unsigned short id;
717 struct mbuf *m_new;
718 int i, batch_target, notify;
719 RING_IDX req_prod;
720 grant_ref_t ref;
721 netif_rx_request_t *req;
722 vm_offset_t vaddr;
723 u_long pfn;
724
725 req_prod = sc->rx.req_prod_pvt;
726
727 if (__predict_false(sc->carrier == 0))
728 return;
729
730 /*
731 * Allocate mbufs greedily, even though we batch updates to the
732 * receive ring. This creates a less bursty demand on the memory
733 * allocator, and so should reduce the chance of failed allocation
734 * requests both for ourself and for other kernel subsystems.
735 *
736 * Here we attempt to maintain rx_target buffers in flight, counting
737 * buffers that we have yet to process in the receive ring.
738 */
739 batch_target = sc->rx_target - (req_prod - sc->rx.rsp_cons);
740 for (i = mbufq_len(&sc->xn_rx_batch); i < batch_target; i++) {
741 m_new = m_getjcl(M_NOWAIT, MT_DATA, M_PKTHDR, MJUMPAGESIZE);
742 if (m_new == NULL) {
743 if (i != 0)
744 goto refill;
745 /*
746 * XXX set timer
747 */
748 break;
749 }
750 m_new->m_len = m_new->m_pkthdr.len = MJUMPAGESIZE;
751
752 /* queue the mbufs allocated */
753 (void )mbufq_enqueue(&sc->xn_rx_batch, m_new);
754 }
755
756 /*
757 * If we've allocated at least half of our target number of entries,
758 * submit them to the backend - we have enough to make the overhead
759 * of submission worthwhile. Otherwise wait for more mbufs and
760 * request entries to become available.
761 */
762 if (i < (sc->rx_target/2)) {
763 if (req_prod >sc->rx.sring->req_prod)
764 goto push;
765 return;
766 }
767
768 /*
769 * Double floating fill target if we risked having the backend
770 * run out of empty buffers for receive traffic. We define "running
771 * low" as having less than a fourth of our target buffers free
772 * at the time we refilled the queue.
773 */
774 if ((req_prod - sc->rx.sring->rsp_prod) < (sc->rx_target / 4)) {
775 sc->rx_target *= 2;
776 if (sc->rx_target > sc->rx_max_target)
777 sc->rx_target = sc->rx_max_target;
778 }
779
780 refill:
781 for (i = 0; ; i++) {
782 if ((m_new = mbufq_dequeue(&sc->xn_rx_batch)) == NULL)
783 break;
784
785 m_new->m_ext.ext_arg1 = (vm_paddr_t *)(uintptr_t)(
786 vtophys(m_new->m_ext.ext_buf) >> PAGE_SHIFT);
787
788 id = xennet_rxidx(req_prod + i);
789
790 KASSERT(sc->rx_mbufs[id] == NULL, ("non-NULL xm_rx_chain"));
791 sc->rx_mbufs[id] = m_new;
792
793 ref = gnttab_claim_grant_reference(&sc->gref_rx_head);
794 KASSERT(ref != GNTTAB_LIST_END,
795 ("reserved grant references exhuasted"));
796 sc->grant_rx_ref[id] = ref;
797
798 vaddr = mtod(m_new, vm_offset_t);
799 pfn = vtophys(vaddr) >> PAGE_SHIFT;
800 req = RING_GET_REQUEST(&sc->rx, req_prod + i);
801
802 gnttab_grant_foreign_access_ref(ref, otherend_id, pfn, 0);
803 req->id = id;
804 req->gref = ref;
805
806 sc->rx_pfn_array[i] =
807 vtophys(mtod(m_new,vm_offset_t)) >> PAGE_SHIFT;
808 }
809
810 KASSERT(i, ("no mbufs processed")); /* should have returned earlier */
811 KASSERT(mbufq_len(&sc->xn_rx_batch) == 0, ("not all mbufs processed"));
812 /*
813 * We may have allocated buffers which have entries outstanding
814 * in the page * update queue -- make sure we flush those first!
815 */
816 wmb();
817
818 /* Above is a suitable barrier to ensure backend will see requests. */
819 sc->rx.req_prod_pvt = req_prod + i;
820 push:
821 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&sc->rx, notify);
822 if (notify)
823 xen_intr_signal(sc->xen_intr_handle);
824 }
825
826 static void
xn_rxeof(struct netfront_info * np)827 xn_rxeof(struct netfront_info *np)
828 {
829 struct ifnet *ifp;
830 #if (defined(INET) || defined(INET6))
831 struct lro_ctrl *lro = &np->xn_lro;
832 struct lro_entry *queued;
833 #endif
834 struct netfront_rx_info rinfo;
835 struct netif_rx_response *rx = &rinfo.rx;
836 struct netif_extra_info *extras = rinfo.extras;
837 RING_IDX i, rp;
838 struct mbuf *m;
839 struct mbufq rxq, errq;
840 int err, work_to_do;
841
842 do {
843 XN_RX_LOCK_ASSERT(np);
844 if (!netfront_carrier_ok(np))
845 return;
846
847 /* XXX: there should be some sane limit. */
848 mbufq_init(&errq, INT_MAX);
849 mbufq_init(&rxq, INT_MAX);
850
851 ifp = np->xn_ifp;
852
853 rp = np->rx.sring->rsp_prod;
854 rmb(); /* Ensure we see queued responses up to 'rp'. */
855
856 i = np->rx.rsp_cons;
857 while ((i != rp)) {
858 memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx));
859 memset(extras, 0, sizeof(rinfo.extras));
860
861 m = NULL;
862 err = xennet_get_responses(np, &rinfo, rp, &i, &m);
863
864 if (__predict_false(err)) {
865 if (m)
866 (void )mbufq_enqueue(&errq, m);
867 np->stats.rx_errors++;
868 continue;
869 }
870
871 m->m_pkthdr.rcvif = ifp;
872 if ( rx->flags & NETRXF_data_validated ) {
873 /* Tell the stack the checksums are okay */
874 /*
875 * XXX this isn't necessarily the case - need to add
876 * check
877 */
878
879 m->m_pkthdr.csum_flags |=
880 (CSUM_IP_CHECKED | CSUM_IP_VALID | CSUM_DATA_VALID
881 | CSUM_PSEUDO_HDR);
882 m->m_pkthdr.csum_data = 0xffff;
883 }
884
885 np->stats.rx_packets++;
886 np->stats.rx_bytes += m->m_pkthdr.len;
887
888 (void )mbufq_enqueue(&rxq, m);
889 np->rx.rsp_cons = i;
890 }
891
892 mbufq_drain(&errq);
893
894 /*
895 * Process all the mbufs after the remapping is complete.
896 * Break the mbuf chain first though.
897 */
898 while ((m = mbufq_dequeue(&rxq)) != NULL) {
899 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
900
901 /*
902 * Do we really need to drop the rx lock?
903 */
904 XN_RX_UNLOCK(np);
905 #if (defined(INET) || defined(INET6))
906 /* Use LRO if possible */
907 if ((ifp->if_capenable & IFCAP_LRO) == 0 ||
908 lro->lro_cnt == 0 || tcp_lro_rx(lro, m, 0)) {
909 /*
910 * If LRO fails, pass up to the stack
911 * directly.
912 */
913 (*ifp->if_input)(ifp, m);
914 }
915 #else
916 (*ifp->if_input)(ifp, m);
917 #endif
918 XN_RX_LOCK(np);
919 }
920
921 np->rx.rsp_cons = i;
922
923 #if (defined(INET) || defined(INET6))
924 /*
925 * Flush any outstanding LRO work
926 */
927 while (!SLIST_EMPTY(&lro->lro_active)) {
928 queued = SLIST_FIRST(&lro->lro_active);
929 SLIST_REMOVE_HEAD(&lro->lro_active, next);
930 tcp_lro_flush(lro, queued);
931 }
932 #endif
933
934 #if 0
935 /* If we get a callback with very few responses, reduce fill target. */
936 /* NB. Note exponential increase, linear decrease. */
937 if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) >
938 ((3*np->rx_target) / 4)) && (--np->rx_target < np->rx_min_target))
939 np->rx_target = np->rx_min_target;
940 #endif
941
942 network_alloc_rx_buffers(np);
943
944 RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, work_to_do);
945 } while (work_to_do);
946 }
947
948 static void
xn_txeof(struct netfront_info * np)949 xn_txeof(struct netfront_info *np)
950 {
951 RING_IDX i, prod;
952 unsigned short id;
953 struct ifnet *ifp;
954 netif_tx_response_t *txr;
955 struct mbuf *m;
956
957 XN_TX_LOCK_ASSERT(np);
958
959 if (!netfront_carrier_ok(np))
960 return;
961
962 ifp = np->xn_ifp;
963
964 do {
965 prod = np->tx.sring->rsp_prod;
966 rmb(); /* Ensure we see responses up to 'rp'. */
967
968 for (i = np->tx.rsp_cons; i != prod; i++) {
969 txr = RING_GET_RESPONSE(&np->tx, i);
970 if (txr->status == NETIF_RSP_NULL)
971 continue;
972
973 if (txr->status != NETIF_RSP_OKAY) {
974 printf("%s: WARNING: response is %d!\n",
975 __func__, txr->status);
976 }
977 id = txr->id;
978 m = np->tx_mbufs[id];
979 KASSERT(m != NULL, ("mbuf not found in xn_tx_chain"));
980 KASSERT((uintptr_t)m > NET_TX_RING_SIZE,
981 ("mbuf already on the free list, but we're "
982 "trying to free it again!"));
983 M_ASSERTVALID(m);
984
985 /*
986 * Increment packet count if this is the last
987 * mbuf of the chain.
988 */
989 if (!m->m_next)
990 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1);
991 if (__predict_false(gnttab_query_foreign_access(
992 np->grant_tx_ref[id]) != 0)) {
993 panic("%s: grant id %u still in use by the "
994 "backend", __func__, id);
995 }
996 gnttab_end_foreign_access_ref(
997 np->grant_tx_ref[id]);
998 gnttab_release_grant_reference(
999 &np->gref_tx_head, np->grant_tx_ref[id]);
1000 np->grant_tx_ref[id] = GRANT_REF_INVALID;
1001
1002 np->tx_mbufs[id] = NULL;
1003 add_id_to_freelist(np->tx_mbufs, id);
1004 np->xn_cdata.xn_tx_chain_cnt--;
1005 m_free(m);
1006 /* Only mark the queue active if we've freed up at least one slot to try */
1007 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1008 }
1009 np->tx.rsp_cons = prod;
1010
1011 /*
1012 * Set a new event, then check for race with update of
1013 * tx_cons. Note that it is essential to schedule a
1014 * callback, no matter how few buffers are pending. Even if
1015 * there is space in the transmit ring, higher layers may
1016 * be blocked because too much data is outstanding: in such
1017 * cases notification from Xen is likely to be the only kick
1018 * that we'll get.
1019 */
1020 np->tx.sring->rsp_event =
1021 prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
1022
1023 mb();
1024 } while (prod != np->tx.sring->rsp_prod);
1025
1026 if (np->tx_full &&
1027 ((np->tx.sring->req_prod - prod) < NET_TX_RING_SIZE)) {
1028 np->tx_full = 0;
1029 #if 0
1030 if (np->user_state == UST_OPEN)
1031 netif_wake_queue(dev);
1032 #endif
1033 }
1034 }
1035
1036 static void
xn_intr(void * xsc)1037 xn_intr(void *xsc)
1038 {
1039 struct netfront_info *np = xsc;
1040 struct ifnet *ifp = np->xn_ifp;
1041
1042 #if 0
1043 if (!(np->rx.rsp_cons != np->rx.sring->rsp_prod &&
1044 likely(netfront_carrier_ok(np)) &&
1045 ifp->if_drv_flags & IFF_DRV_RUNNING))
1046 return;
1047 #endif
1048 if (RING_HAS_UNCONSUMED_RESPONSES(&np->tx)) {
1049 XN_TX_LOCK(np);
1050 xn_txeof(np);
1051 XN_TX_UNLOCK(np);
1052 }
1053
1054 XN_RX_LOCK(np);
1055 xn_rxeof(np);
1056 XN_RX_UNLOCK(np);
1057
1058 if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
1059 !IFQ_DRV_IS_EMPTY(&ifp->if_snd))
1060 xn_start(ifp);
1061 }
1062
1063 static void
xennet_move_rx_slot(struct netfront_info * np,struct mbuf * m,grant_ref_t ref)1064 xennet_move_rx_slot(struct netfront_info *np, struct mbuf *m,
1065 grant_ref_t ref)
1066 {
1067 int new = xennet_rxidx(np->rx.req_prod_pvt);
1068
1069 KASSERT(np->rx_mbufs[new] == NULL, ("rx_mbufs != NULL"));
1070 np->rx_mbufs[new] = m;
1071 np->grant_rx_ref[new] = ref;
1072 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
1073 RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
1074 np->rx.req_prod_pvt++;
1075 }
1076
1077 static int
xennet_get_extras(struct netfront_info * np,struct netif_extra_info * extras,RING_IDX rp,RING_IDX * cons)1078 xennet_get_extras(struct netfront_info *np,
1079 struct netif_extra_info *extras, RING_IDX rp, RING_IDX *cons)
1080 {
1081 struct netif_extra_info *extra;
1082
1083 int err = 0;
1084
1085 do {
1086 struct mbuf *m;
1087 grant_ref_t ref;
1088
1089 if (__predict_false(*cons + 1 == rp)) {
1090 #if 0
1091 if (net_ratelimit())
1092 WPRINTK("Missing extra info\n");
1093 #endif
1094 err = EINVAL;
1095 break;
1096 }
1097
1098 extra = (struct netif_extra_info *)
1099 RING_GET_RESPONSE(&np->rx, ++(*cons));
1100
1101 if (__predict_false(!extra->type ||
1102 extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
1103 #if 0
1104 if (net_ratelimit())
1105 WPRINTK("Invalid extra type: %d\n",
1106 extra->type);
1107 #endif
1108 err = EINVAL;
1109 } else {
1110 memcpy(&extras[extra->type - 1], extra, sizeof(*extra));
1111 }
1112
1113 m = xennet_get_rx_mbuf(np, *cons);
1114 ref = xennet_get_rx_ref(np, *cons);
1115 xennet_move_rx_slot(np, m, ref);
1116 } while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
1117
1118 return err;
1119 }
1120
1121 static int
xennet_get_responses(struct netfront_info * np,struct netfront_rx_info * rinfo,RING_IDX rp,RING_IDX * cons,struct mbuf ** list)1122 xennet_get_responses(struct netfront_info *np,
1123 struct netfront_rx_info *rinfo, RING_IDX rp, RING_IDX *cons,
1124 struct mbuf **list)
1125 {
1126 struct netif_rx_response *rx = &rinfo->rx;
1127 struct netif_extra_info *extras = rinfo->extras;
1128 struct mbuf *m, *m0, *m_prev;
1129 grant_ref_t ref = xennet_get_rx_ref(np, *cons);
1130 RING_IDX ref_cons = *cons;
1131 int frags = 1;
1132 int err = 0;
1133 u_long ret;
1134
1135 m0 = m = m_prev = xennet_get_rx_mbuf(np, *cons);
1136
1137 if (rx->flags & NETRXF_extra_info) {
1138 err = xennet_get_extras(np, extras, rp, cons);
1139 }
1140
1141 if (m0 != NULL) {
1142 m0->m_pkthdr.len = 0;
1143 m0->m_next = NULL;
1144 }
1145
1146 for (;;) {
1147 #if 0
1148 DPRINTK("rx->status=%hd rx->offset=%hu frags=%u\n",
1149 rx->status, rx->offset, frags);
1150 #endif
1151 if (__predict_false(rx->status < 0 ||
1152 rx->offset + rx->status > PAGE_SIZE)) {
1153
1154 #if 0
1155 if (net_ratelimit())
1156 WPRINTK("rx->offset: %x, size: %u\n",
1157 rx->offset, rx->status);
1158 #endif
1159 xennet_move_rx_slot(np, m, ref);
1160 if (m0 == m)
1161 m0 = NULL;
1162 m = NULL;
1163 err = EINVAL;
1164 goto next_skip_queue;
1165 }
1166
1167 /*
1168 * This definitely indicates a bug, either in this driver or in
1169 * the backend driver. In future this should flag the bad
1170 * situation to the system controller to reboot the backed.
1171 */
1172 if (ref == GRANT_REF_INVALID) {
1173
1174 #if 0
1175 if (net_ratelimit())
1176 WPRINTK("Bad rx response id %d.\n", rx->id);
1177 #endif
1178 printf("%s: Bad rx response id %d.\n", __func__,rx->id);
1179 err = EINVAL;
1180 goto next;
1181 }
1182
1183 ret = gnttab_end_foreign_access_ref(ref);
1184 KASSERT(ret, ("Unable to end access to grant references"));
1185
1186 gnttab_release_grant_reference(&np->gref_rx_head, ref);
1187
1188 next:
1189 if (m == NULL)
1190 break;
1191
1192 m->m_len = rx->status;
1193 m->m_data += rx->offset;
1194 m0->m_pkthdr.len += rx->status;
1195
1196 next_skip_queue:
1197 if (!(rx->flags & NETRXF_more_data))
1198 break;
1199
1200 if (*cons + frags == rp) {
1201 if (net_ratelimit())
1202 WPRINTK("Need more frags\n");
1203 err = ENOENT;
1204 printf("%s: cons %u frags %u rp %u, not enough frags\n",
1205 __func__, *cons, frags, rp);
1206 break;
1207 }
1208 /*
1209 * Note that m can be NULL, if rx->status < 0 or if
1210 * rx->offset + rx->status > PAGE_SIZE above.
1211 */
1212 m_prev = m;
1213
1214 rx = RING_GET_RESPONSE(&np->rx, *cons + frags);
1215 m = xennet_get_rx_mbuf(np, *cons + frags);
1216
1217 /*
1218 * m_prev == NULL can happen if rx->status < 0 or if
1219 * rx->offset + * rx->status > PAGE_SIZE above.
1220 */
1221 if (m_prev != NULL)
1222 m_prev->m_next = m;
1223
1224 /*
1225 * m0 can be NULL if rx->status < 0 or if * rx->offset +
1226 * rx->status > PAGE_SIZE above.
1227 */
1228 if (m0 == NULL)
1229 m0 = m;
1230 m->m_next = NULL;
1231 ref = xennet_get_rx_ref(np, *cons + frags);
1232 ref_cons = *cons + frags;
1233 frags++;
1234 }
1235 *list = m0;
1236 *cons += frags;
1237
1238 return (err);
1239 }
1240
1241 static void
xn_tick_locked(struct netfront_info * sc)1242 xn_tick_locked(struct netfront_info *sc)
1243 {
1244 XN_RX_LOCK_ASSERT(sc);
1245 callout_reset(&sc->xn_stat_ch, hz, xn_tick, sc);
1246
1247 /* XXX placeholder for printing debug information */
1248 }
1249
1250 static void
xn_tick(void * xsc)1251 xn_tick(void *xsc)
1252 {
1253 struct netfront_info *sc;
1254
1255 sc = xsc;
1256 XN_RX_LOCK(sc);
1257 xn_tick_locked(sc);
1258 XN_RX_UNLOCK(sc);
1259 }
1260
1261 /**
1262 * \brief Count the number of fragments in an mbuf chain.
1263 *
1264 * Surprisingly, there isn't an M* macro for this.
1265 */
1266 static inline int
xn_count_frags(struct mbuf * m)1267 xn_count_frags(struct mbuf *m)
1268 {
1269 int nfrags;
1270
1271 for (nfrags = 0; m != NULL; m = m->m_next)
1272 nfrags++;
1273
1274 return (nfrags);
1275 }
1276
1277 /**
1278 * Given an mbuf chain, make sure we have enough room and then push
1279 * it onto the transmit ring.
1280 */
1281 static int
xn_assemble_tx_request(struct netfront_info * sc,struct mbuf * m_head)1282 xn_assemble_tx_request(struct netfront_info *sc, struct mbuf *m_head)
1283 {
1284 struct ifnet *ifp;
1285 struct mbuf *m;
1286 u_int nfrags;
1287 int otherend_id;
1288
1289 ifp = sc->xn_ifp;
1290
1291 /**
1292 * Defragment the mbuf if necessary.
1293 */
1294 nfrags = xn_count_frags(m_head);
1295
1296 /*
1297 * Check to see whether this request is longer than netback
1298 * can handle, and try to defrag it.
1299 */
1300 /**
1301 * It is a bit lame, but the netback driver in Linux can't
1302 * deal with nfrags > MAX_TX_REQ_FRAGS, which is a quirk of
1303 * the Linux network stack.
1304 */
1305 if (nfrags > sc->maxfrags) {
1306 m = m_defrag(m_head, M_NOWAIT);
1307 if (!m) {
1308 /*
1309 * Defrag failed, so free the mbuf and
1310 * therefore drop the packet.
1311 */
1312 m_freem(m_head);
1313 return (EMSGSIZE);
1314 }
1315 m_head = m;
1316 }
1317
1318 /* Determine how many fragments now exist */
1319 nfrags = xn_count_frags(m_head);
1320
1321 /*
1322 * Check to see whether the defragmented packet has too many
1323 * segments for the Linux netback driver.
1324 */
1325 /**
1326 * The FreeBSD TCP stack, with TSO enabled, can produce a chain
1327 * of mbufs longer than Linux can handle. Make sure we don't
1328 * pass a too-long chain over to the other side by dropping the
1329 * packet. It doesn't look like there is currently a way to
1330 * tell the TCP stack to generate a shorter chain of packets.
1331 */
1332 if (nfrags > MAX_TX_REQ_FRAGS) {
1333 #ifdef DEBUG
1334 printf("%s: nfrags %d > MAX_TX_REQ_FRAGS %d, netback "
1335 "won't be able to handle it, dropping\n",
1336 __func__, nfrags, MAX_TX_REQ_FRAGS);
1337 #endif
1338 m_freem(m_head);
1339 return (EMSGSIZE);
1340 }
1341
1342 /*
1343 * This check should be redundant. We've already verified that we
1344 * have enough slots in the ring to handle a packet of maximum
1345 * size, and that our packet is less than the maximum size. Keep
1346 * it in here as an assert for now just to make certain that
1347 * xn_tx_chain_cnt is accurate.
1348 */
1349 KASSERT((sc->xn_cdata.xn_tx_chain_cnt + nfrags) <= NET_TX_RING_SIZE,
1350 ("%s: xn_tx_chain_cnt (%d) + nfrags (%d) > NET_TX_RING_SIZE "
1351 "(%d)!", __func__, (int) sc->xn_cdata.xn_tx_chain_cnt,
1352 (int) nfrags, (int) NET_TX_RING_SIZE));
1353
1354 /*
1355 * Start packing the mbufs in this chain into
1356 * the fragment pointers. Stop when we run out
1357 * of fragments or hit the end of the mbuf chain.
1358 */
1359 m = m_head;
1360 otherend_id = xenbus_get_otherend_id(sc->xbdev);
1361 for (m = m_head; m; m = m->m_next) {
1362 netif_tx_request_t *tx;
1363 uintptr_t id;
1364 grant_ref_t ref;
1365 u_long mfn; /* XXX Wrong type? */
1366
1367 tx = RING_GET_REQUEST(&sc->tx, sc->tx.req_prod_pvt);
1368 id = get_id_from_freelist(sc->tx_mbufs);
1369 if (id == 0)
1370 panic("%s: was allocated the freelist head!\n",
1371 __func__);
1372 sc->xn_cdata.xn_tx_chain_cnt++;
1373 if (sc->xn_cdata.xn_tx_chain_cnt > NET_TX_RING_SIZE)
1374 panic("%s: tx_chain_cnt must be <= NET_TX_RING_SIZE\n",
1375 __func__);
1376 sc->tx_mbufs[id] = m;
1377 tx->id = id;
1378 ref = gnttab_claim_grant_reference(&sc->gref_tx_head);
1379 KASSERT((short)ref >= 0, ("Negative ref"));
1380 mfn = virt_to_mfn(mtod(m, vm_offset_t));
1381 gnttab_grant_foreign_access_ref(ref, otherend_id,
1382 mfn, GNTMAP_readonly);
1383 tx->gref = sc->grant_tx_ref[id] = ref;
1384 tx->offset = mtod(m, vm_offset_t) & (PAGE_SIZE - 1);
1385 tx->flags = 0;
1386 if (m == m_head) {
1387 /*
1388 * The first fragment has the entire packet
1389 * size, subsequent fragments have just the
1390 * fragment size. The backend works out the
1391 * true size of the first fragment by
1392 * subtracting the sizes of the other
1393 * fragments.
1394 */
1395 tx->size = m->m_pkthdr.len;
1396
1397 /*
1398 * The first fragment contains the checksum flags
1399 * and is optionally followed by extra data for
1400 * TSO etc.
1401 */
1402 /**
1403 * CSUM_TSO requires checksum offloading.
1404 * Some versions of FreeBSD fail to
1405 * set CSUM_TCP in the CSUM_TSO case,
1406 * so we have to test for CSUM_TSO
1407 * explicitly.
1408 */
1409 if (m->m_pkthdr.csum_flags
1410 & (CSUM_DELAY_DATA | CSUM_TSO)) {
1411 tx->flags |= (NETTXF_csum_blank
1412 | NETTXF_data_validated);
1413 }
1414 if (m->m_pkthdr.csum_flags & CSUM_TSO) {
1415 struct netif_extra_info *gso =
1416 (struct netif_extra_info *)
1417 RING_GET_REQUEST(&sc->tx,
1418 ++sc->tx.req_prod_pvt);
1419
1420 tx->flags |= NETTXF_extra_info;
1421
1422 gso->u.gso.size = m->m_pkthdr.tso_segsz;
1423 gso->u.gso.type =
1424 XEN_NETIF_GSO_TYPE_TCPV4;
1425 gso->u.gso.pad = 0;
1426 gso->u.gso.features = 0;
1427
1428 gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
1429 gso->flags = 0;
1430 }
1431 } else {
1432 tx->size = m->m_len;
1433 }
1434 if (m->m_next)
1435 tx->flags |= NETTXF_more_data;
1436
1437 sc->tx.req_prod_pvt++;
1438 }
1439 BPF_MTAP(ifp, m_head);
1440
1441 sc->stats.tx_bytes += m_head->m_pkthdr.len;
1442 sc->stats.tx_packets++;
1443
1444 return (0);
1445 }
1446
1447 static void
xn_start_locked(struct ifnet * ifp)1448 xn_start_locked(struct ifnet *ifp)
1449 {
1450 struct netfront_info *sc;
1451 struct mbuf *m_head;
1452 int notify;
1453
1454 sc = ifp->if_softc;
1455
1456 if (!netfront_carrier_ok(sc))
1457 return;
1458
1459 /*
1460 * While we have enough transmit slots available for at least one
1461 * maximum-sized packet, pull mbufs off the queue and put them on
1462 * the transmit ring.
1463 */
1464 while (xn_tx_slot_available(sc)) {
1465 IF_DEQUEUE(&ifp->if_snd, m_head);
1466 if (m_head == NULL)
1467 break;
1468
1469 if (xn_assemble_tx_request(sc, m_head) != 0)
1470 break;
1471 }
1472
1473 RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&sc->tx, notify);
1474 if (notify)
1475 xen_intr_signal(sc->xen_intr_handle);
1476
1477 if (RING_FULL(&sc->tx)) {
1478 sc->tx_full = 1;
1479 #if 0
1480 netif_stop_queue(dev);
1481 #endif
1482 }
1483 }
1484
1485 static void
xn_start(struct ifnet * ifp)1486 xn_start(struct ifnet *ifp)
1487 {
1488 struct netfront_info *sc;
1489 sc = ifp->if_softc;
1490 XN_TX_LOCK(sc);
1491 xn_start_locked(ifp);
1492 XN_TX_UNLOCK(sc);
1493 }
1494
1495 /* equivalent of network_open() in Linux */
1496 static void
xn_ifinit_locked(struct netfront_info * sc)1497 xn_ifinit_locked(struct netfront_info *sc)
1498 {
1499 struct ifnet *ifp;
1500
1501 XN_LOCK_ASSERT(sc);
1502
1503 ifp = sc->xn_ifp;
1504
1505 if (ifp->if_drv_flags & IFF_DRV_RUNNING)
1506 return;
1507
1508 xn_stop(sc);
1509
1510 network_alloc_rx_buffers(sc);
1511 sc->rx.sring->rsp_event = sc->rx.rsp_cons + 1;
1512
1513 ifp->if_drv_flags |= IFF_DRV_RUNNING;
1514 ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1515 if_link_state_change(ifp, LINK_STATE_UP);
1516
1517 callout_reset(&sc->xn_stat_ch, hz, xn_tick, sc);
1518 }
1519
1520 static void
xn_ifinit(void * xsc)1521 xn_ifinit(void *xsc)
1522 {
1523 struct netfront_info *sc = xsc;
1524
1525 XN_LOCK(sc);
1526 xn_ifinit_locked(sc);
1527 XN_UNLOCK(sc);
1528 }
1529
1530 static int
xn_ioctl(struct ifnet * ifp,u_long cmd,caddr_t data)1531 xn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1532 {
1533 struct netfront_info *sc = ifp->if_softc;
1534 struct ifreq *ifr = (struct ifreq *) data;
1535 #ifdef INET
1536 struct ifaddr *ifa = (struct ifaddr *)data;
1537 #endif
1538
1539 int mask, error = 0;
1540 switch(cmd) {
1541 case SIOCSIFADDR:
1542 #ifdef INET
1543 XN_LOCK(sc);
1544 if (ifa->ifa_addr->sa_family == AF_INET) {
1545 ifp->if_flags |= IFF_UP;
1546 if (!(ifp->if_drv_flags & IFF_DRV_RUNNING))
1547 xn_ifinit_locked(sc);
1548 arp_ifinit(ifp, ifa);
1549 XN_UNLOCK(sc);
1550 } else {
1551 XN_UNLOCK(sc);
1552 #endif
1553 error = ether_ioctl(ifp, cmd, data);
1554 #ifdef INET
1555 }
1556 #endif
1557 break;
1558 case SIOCSIFMTU:
1559 /* XXX can we alter the MTU on a VN ?*/
1560 #ifdef notyet
1561 if (ifr->ifr_mtu > XN_JUMBO_MTU)
1562 error = EINVAL;
1563 else
1564 #endif
1565 {
1566 ifp->if_mtu = ifr->ifr_mtu;
1567 ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1568 xn_ifinit(sc);
1569 }
1570 break;
1571 case SIOCSIFFLAGS:
1572 XN_LOCK(sc);
1573 if (ifp->if_flags & IFF_UP) {
1574 /*
1575 * If only the state of the PROMISC flag changed,
1576 * then just use the 'set promisc mode' command
1577 * instead of reinitializing the entire NIC. Doing
1578 * a full re-init means reloading the firmware and
1579 * waiting for it to start up, which may take a
1580 * second or two.
1581 */
1582 #ifdef notyet
1583 /* No promiscuous mode with Xen */
1584 if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
1585 ifp->if_flags & IFF_PROMISC &&
1586 !(sc->xn_if_flags & IFF_PROMISC)) {
1587 XN_SETBIT(sc, XN_RX_MODE,
1588 XN_RXMODE_RX_PROMISC);
1589 } else if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
1590 !(ifp->if_flags & IFF_PROMISC) &&
1591 sc->xn_if_flags & IFF_PROMISC) {
1592 XN_CLRBIT(sc, XN_RX_MODE,
1593 XN_RXMODE_RX_PROMISC);
1594 } else
1595 #endif
1596 xn_ifinit_locked(sc);
1597 } else {
1598 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1599 xn_stop(sc);
1600 }
1601 }
1602 sc->xn_if_flags = ifp->if_flags;
1603 XN_UNLOCK(sc);
1604 error = 0;
1605 break;
1606 case SIOCSIFCAP:
1607 mask = ifr->ifr_reqcap ^ ifp->if_capenable;
1608 if (mask & IFCAP_TXCSUM) {
1609 if (IFCAP_TXCSUM & ifp->if_capenable) {
1610 ifp->if_capenable &= ~(IFCAP_TXCSUM|IFCAP_TSO4);
1611 ifp->if_hwassist &= ~(CSUM_TCP | CSUM_UDP
1612 | CSUM_IP | CSUM_TSO);
1613 } else {
1614 ifp->if_capenable |= IFCAP_TXCSUM;
1615 ifp->if_hwassist |= (CSUM_TCP | CSUM_UDP
1616 | CSUM_IP);
1617 }
1618 }
1619 if (mask & IFCAP_RXCSUM) {
1620 ifp->if_capenable ^= IFCAP_RXCSUM;
1621 }
1622 if (mask & IFCAP_TSO4) {
1623 if (IFCAP_TSO4 & ifp->if_capenable) {
1624 ifp->if_capenable &= ~IFCAP_TSO4;
1625 ifp->if_hwassist &= ~CSUM_TSO;
1626 } else if (IFCAP_TXCSUM & ifp->if_capenable) {
1627 ifp->if_capenable |= IFCAP_TSO4;
1628 ifp->if_hwassist |= CSUM_TSO;
1629 } else {
1630 IPRINTK("Xen requires tx checksum offload"
1631 " be enabled to use TSO\n");
1632 error = EINVAL;
1633 }
1634 }
1635 if (mask & IFCAP_LRO) {
1636 ifp->if_capenable ^= IFCAP_LRO;
1637
1638 }
1639 error = 0;
1640 break;
1641 case SIOCADDMULTI:
1642 case SIOCDELMULTI:
1643 #ifdef notyet
1644 if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1645 XN_LOCK(sc);
1646 xn_setmulti(sc);
1647 XN_UNLOCK(sc);
1648 error = 0;
1649 }
1650 #endif
1651 break;
1652 case SIOCSIFMEDIA:
1653 case SIOCGIFMEDIA:
1654 error = ifmedia_ioctl(ifp, ifr, &sc->sc_media, cmd);
1655 break;
1656 default:
1657 error = ether_ioctl(ifp, cmd, data);
1658 }
1659
1660 return (error);
1661 }
1662
1663 static void
xn_stop(struct netfront_info * sc)1664 xn_stop(struct netfront_info *sc)
1665 {
1666 struct ifnet *ifp;
1667
1668 XN_LOCK_ASSERT(sc);
1669
1670 ifp = sc->xn_ifp;
1671
1672 callout_stop(&sc->xn_stat_ch);
1673
1674 xn_free_rx_ring(sc);
1675 xn_free_tx_ring(sc);
1676
1677 ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
1678 if_link_state_change(ifp, LINK_STATE_DOWN);
1679 }
1680
1681 /* START of Xenolinux helper functions adapted to FreeBSD */
1682 int
network_connect(struct netfront_info * np)1683 network_connect(struct netfront_info *np)
1684 {
1685 int i, requeue_idx, error;
1686 grant_ref_t ref;
1687 netif_rx_request_t *req;
1688 u_int feature_rx_copy;
1689
1690 error = xs_scanf(XST_NIL, xenbus_get_otherend_path(np->xbdev),
1691 "feature-rx-copy", NULL, "%u", &feature_rx_copy);
1692 if (error)
1693 feature_rx_copy = 0;
1694
1695 /* We only support rx copy. */
1696 if (!feature_rx_copy)
1697 return (EPROTONOSUPPORT);
1698
1699 /* Recovery procedure: */
1700 error = talk_to_backend(np->xbdev, np);
1701 if (error)
1702 return (error);
1703
1704 /* Step 1: Reinitialise variables. */
1705 xn_query_features(np);
1706 xn_configure_features(np);
1707 netif_release_tx_bufs(np);
1708
1709 /* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
1710 for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
1711 struct mbuf *m;
1712 u_long pfn;
1713
1714 if (np->rx_mbufs[i] == NULL)
1715 continue;
1716
1717 m = np->rx_mbufs[requeue_idx] = xennet_get_rx_mbuf(np, i);
1718 ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i);
1719
1720 req = RING_GET_REQUEST(&np->rx, requeue_idx);
1721 pfn = vtophys(mtod(m, vm_offset_t)) >> PAGE_SHIFT;
1722
1723 gnttab_grant_foreign_access_ref(ref,
1724 xenbus_get_otherend_id(np->xbdev),
1725 pfn, 0);
1726
1727 req->gref = ref;
1728 req->id = requeue_idx;
1729
1730 requeue_idx++;
1731 }
1732
1733 np->rx.req_prod_pvt = requeue_idx;
1734
1735 /* Step 3: All public and private state should now be sane. Get
1736 * ready to start sending and receiving packets and give the driver
1737 * domain a kick because we've probably just requeued some
1738 * packets.
1739 */
1740 netfront_carrier_on(np);
1741 xen_intr_signal(np->xen_intr_handle);
1742 XN_TX_LOCK(np);
1743 xn_txeof(np);
1744 XN_TX_UNLOCK(np);
1745 network_alloc_rx_buffers(np);
1746
1747 return (0);
1748 }
1749
1750 static void
xn_query_features(struct netfront_info * np)1751 xn_query_features(struct netfront_info *np)
1752 {
1753 int val;
1754
1755 device_printf(np->xbdev, "backend features:");
1756
1757 if (xs_scanf(XST_NIL, xenbus_get_otherend_path(np->xbdev),
1758 "feature-sg", NULL, "%d", &val) < 0)
1759 val = 0;
1760
1761 np->maxfrags = 1;
1762 if (val) {
1763 np->maxfrags = MAX_TX_REQ_FRAGS;
1764 printf(" feature-sg");
1765 }
1766
1767 if (xs_scanf(XST_NIL, xenbus_get_otherend_path(np->xbdev),
1768 "feature-gso-tcpv4", NULL, "%d", &val) < 0)
1769 val = 0;
1770
1771 np->xn_ifp->if_capabilities &= ~(IFCAP_TSO4|IFCAP_LRO);
1772 if (val) {
1773 np->xn_ifp->if_capabilities |= IFCAP_TSO4|IFCAP_LRO;
1774 printf(" feature-gso-tcp4");
1775 }
1776
1777 printf("\n");
1778 }
1779
1780 static int
xn_configure_features(struct netfront_info * np)1781 xn_configure_features(struct netfront_info *np)
1782 {
1783 int err, cap_enabled;
1784
1785 err = 0;
1786
1787 if (np->xn_resume &&
1788 ((np->xn_ifp->if_capenable & np->xn_ifp->if_capabilities)
1789 == np->xn_ifp->if_capenable)) {
1790 /* Current options are available, no need to do anything. */
1791 return (0);
1792 }
1793
1794 /* Try to preserve as many options as possible. */
1795 if (np->xn_resume)
1796 cap_enabled = np->xn_ifp->if_capenable;
1797 else
1798 cap_enabled = UINT_MAX;
1799
1800 #if (defined(INET) || defined(INET6))
1801 if ((np->xn_ifp->if_capenable & IFCAP_LRO) == (cap_enabled & IFCAP_LRO))
1802 tcp_lro_free(&np->xn_lro);
1803 #endif
1804 np->xn_ifp->if_capenable =
1805 np->xn_ifp->if_capabilities & ~(IFCAP_LRO|IFCAP_TSO4) & cap_enabled;
1806 np->xn_ifp->if_hwassist &= ~CSUM_TSO;
1807 #if (defined(INET) || defined(INET6))
1808 if (xn_enable_lro && (np->xn_ifp->if_capabilities & IFCAP_LRO) ==
1809 (cap_enabled & IFCAP_LRO)) {
1810 err = tcp_lro_init(&np->xn_lro);
1811 if (err) {
1812 device_printf(np->xbdev, "LRO initialization failed\n");
1813 } else {
1814 np->xn_lro.ifp = np->xn_ifp;
1815 np->xn_ifp->if_capenable |= IFCAP_LRO;
1816 }
1817 }
1818 if ((np->xn_ifp->if_capabilities & IFCAP_TSO4) ==
1819 (cap_enabled & IFCAP_TSO4)) {
1820 np->xn_ifp->if_capenable |= IFCAP_TSO4;
1821 np->xn_ifp->if_hwassist |= CSUM_TSO;
1822 }
1823 #endif
1824 return (err);
1825 }
1826
1827 /**
1828 * Create a network device.
1829 * @param dev Newbus device representing this virtual NIC.
1830 */
1831 int
create_netdev(device_t dev)1832 create_netdev(device_t dev)
1833 {
1834 int i;
1835 struct netfront_info *np;
1836 int err;
1837 struct ifnet *ifp;
1838
1839 np = device_get_softc(dev);
1840
1841 np->xbdev = dev;
1842
1843 mtx_init(&np->tx_lock, "xntx", "netfront transmit lock", MTX_DEF);
1844 mtx_init(&np->rx_lock, "xnrx", "netfront receive lock", MTX_DEF);
1845 mtx_init(&np->sc_lock, "xnsc", "netfront softc lock", MTX_DEF);
1846
1847 ifmedia_init(&np->sc_media, 0, xn_ifmedia_upd, xn_ifmedia_sts);
1848 ifmedia_add(&np->sc_media, IFM_ETHER|IFM_MANUAL, 0, NULL);
1849 ifmedia_set(&np->sc_media, IFM_ETHER|IFM_MANUAL);
1850
1851 np->rx_target = RX_MIN_TARGET;
1852 np->rx_min_target = RX_MIN_TARGET;
1853 np->rx_max_target = RX_MAX_TARGET;
1854
1855 /* Initialise {tx,rx}_skbs to be a free chain containing every entry. */
1856 for (i = 0; i <= NET_TX_RING_SIZE; i++) {
1857 np->tx_mbufs[i] = (void *) ((u_long) i+1);
1858 np->grant_tx_ref[i] = GRANT_REF_INVALID;
1859 }
1860 np->tx_mbufs[NET_TX_RING_SIZE] = (void *)0;
1861
1862 for (i = 0; i <= NET_RX_RING_SIZE; i++) {
1863
1864 np->rx_mbufs[i] = NULL;
1865 np->grant_rx_ref[i] = GRANT_REF_INVALID;
1866 }
1867
1868 mbufq_init(&np->xn_rx_batch, INT_MAX);
1869
1870 /* A grant for every tx ring slot */
1871 if (gnttab_alloc_grant_references(NET_TX_RING_SIZE,
1872 &np->gref_tx_head) != 0) {
1873 IPRINTK("#### netfront can't alloc tx grant refs\n");
1874 err = ENOMEM;
1875 goto error;
1876 }
1877 /* A grant for every rx ring slot */
1878 if (gnttab_alloc_grant_references(RX_MAX_TARGET,
1879 &np->gref_rx_head) != 0) {
1880 WPRINTK("#### netfront can't alloc rx grant refs\n");
1881 gnttab_free_grant_references(np->gref_tx_head);
1882 err = ENOMEM;
1883 goto error;
1884 }
1885
1886 err = xen_net_read_mac(dev, np->mac);
1887 if (err) {
1888 gnttab_free_grant_references(np->gref_rx_head);
1889 gnttab_free_grant_references(np->gref_tx_head);
1890 goto error;
1891 }
1892
1893 /* Set up ifnet structure */
1894 ifp = np->xn_ifp = if_alloc(IFT_ETHER);
1895 ifp->if_softc = np;
1896 if_initname(ifp, "xn", device_get_unit(dev));
1897 ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
1898 ifp->if_ioctl = xn_ioctl;
1899 ifp->if_start = xn_start;
1900 #ifdef notyet
1901 ifp->if_watchdog = xn_watchdog;
1902 #endif
1903 ifp->if_init = xn_ifinit;
1904 ifp->if_snd.ifq_maxlen = NET_TX_RING_SIZE - 1;
1905
1906 ifp->if_hwassist = XN_CSUM_FEATURES;
1907 ifp->if_capabilities = IFCAP_HWCSUM;
1908 ifp->if_hw_tsomax = 65536 - (ETHER_HDR_LEN + ETHER_VLAN_ENCAP_LEN);
1909 ifp->if_hw_tsomaxsegcount = MAX_TX_REQ_FRAGS;
1910 ifp->if_hw_tsomaxsegsize = PAGE_SIZE;
1911
1912 ether_ifattach(ifp, np->mac);
1913 callout_init(&np->xn_stat_ch, 1);
1914 netfront_carrier_off(np);
1915
1916 return (0);
1917
1918 error:
1919 KASSERT(err != 0, ("Error path with no error code specified"));
1920 return (err);
1921 }
1922
1923 /**
1924 * Handle the change of state of the backend to Closing. We must delete our
1925 * device-layer structures now, to ensure that writes are flushed through to
1926 * the backend. Once is this done, we can switch to Closed in
1927 * acknowledgement.
1928 */
1929 #if 0
1930 static void
1931 netfront_closing(device_t dev)
1932 {
1933 #if 0
1934 struct netfront_info *info = dev->dev_driver_data;
1935
1936 DPRINTK("netfront_closing: %s removed\n", dev->nodename);
1937
1938 close_netdev(info);
1939 #endif
1940 xenbus_switch_state(dev, XenbusStateClosed);
1941 }
1942 #endif
1943
1944 static int
netfront_detach(device_t dev)1945 netfront_detach(device_t dev)
1946 {
1947 struct netfront_info *info = device_get_softc(dev);
1948
1949 DPRINTK("%s\n", xenbus_get_node(dev));
1950
1951 netif_free(info);
1952
1953 return 0;
1954 }
1955
1956 static void
netif_free(struct netfront_info * info)1957 netif_free(struct netfront_info *info)
1958 {
1959 XN_LOCK(info);
1960 xn_stop(info);
1961 XN_UNLOCK(info);
1962 callout_drain(&info->xn_stat_ch);
1963 netif_disconnect_backend(info);
1964 if (info->xn_ifp != NULL) {
1965 ether_ifdetach(info->xn_ifp);
1966 if_free(info->xn_ifp);
1967 info->xn_ifp = NULL;
1968 }
1969 ifmedia_removeall(&info->sc_media);
1970 }
1971
1972 static void
netif_disconnect_backend(struct netfront_info * info)1973 netif_disconnect_backend(struct netfront_info *info)
1974 {
1975 XN_RX_LOCK(info);
1976 XN_TX_LOCK(info);
1977 netfront_carrier_off(info);
1978 XN_TX_UNLOCK(info);
1979 XN_RX_UNLOCK(info);
1980
1981 free_ring(&info->tx_ring_ref, &info->tx.sring);
1982 free_ring(&info->rx_ring_ref, &info->rx.sring);
1983
1984 xen_intr_unbind(&info->xen_intr_handle);
1985 }
1986
1987 static void
free_ring(int * ref,void * ring_ptr_ref)1988 free_ring(int *ref, void *ring_ptr_ref)
1989 {
1990 void **ring_ptr_ptr = ring_ptr_ref;
1991
1992 if (*ref != GRANT_REF_INVALID) {
1993 /* This API frees the associated storage. */
1994 gnttab_end_foreign_access(*ref, *ring_ptr_ptr);
1995 *ref = GRANT_REF_INVALID;
1996 }
1997 *ring_ptr_ptr = NULL;
1998 }
1999
2000 static int
xn_ifmedia_upd(struct ifnet * ifp)2001 xn_ifmedia_upd(struct ifnet *ifp)
2002 {
2003 return (0);
2004 }
2005
2006 static void
xn_ifmedia_sts(struct ifnet * ifp,struct ifmediareq * ifmr)2007 xn_ifmedia_sts(struct ifnet *ifp, struct ifmediareq *ifmr)
2008 {
2009 ifmr->ifm_status = IFM_AVALID|IFM_ACTIVE;
2010 ifmr->ifm_active = IFM_ETHER|IFM_MANUAL;
2011 }
2012
2013 /* ** Driver registration ** */
2014 static device_method_t netfront_methods[] = {
2015 /* Device interface */
2016 DEVMETHOD(device_probe, netfront_probe),
2017 DEVMETHOD(device_attach, netfront_attach),
2018 DEVMETHOD(device_detach, netfront_detach),
2019 DEVMETHOD(device_shutdown, bus_generic_shutdown),
2020 DEVMETHOD(device_suspend, netfront_suspend),
2021 DEVMETHOD(device_resume, netfront_resume),
2022
2023 /* Xenbus interface */
2024 DEVMETHOD(xenbus_otherend_changed, netfront_backend_changed),
2025
2026 DEVMETHOD_END
2027 };
2028
2029 static driver_t netfront_driver = {
2030 "xn",
2031 netfront_methods,
2032 sizeof(struct netfront_info),
2033 };
2034 devclass_t netfront_devclass;
2035
2036 DRIVER_MODULE(xe, xenbusb_front, netfront_driver, netfront_devclass, NULL,
2037 NULL);
2038