xref: /freebsd/sys/dev/xen/netfront/netfront.c (revision aa79fe245de7616cda41b69a296a5ce209c95c45)
1 /*
2  *
3  * Copyright (c) 2004-2006 Kip Macy
4  * All rights reserved.
5  *
6  *
7  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
8  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
9  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
10  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
11  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
12  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
13  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
14  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
15  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
16  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
17  */
18 
19 
20 #include <sys/cdefs.h>
21 __FBSDID("$FreeBSD$");
22 
23 #include <sys/param.h>
24 #include <sys/systm.h>
25 #include <sys/sockio.h>
26 #include <sys/mbuf.h>
27 #include <sys/malloc.h>
28 #include <sys/module.h>
29 #include <sys/kernel.h>
30 #include <sys/socket.h>
31 #include <sys/sysctl.h>
32 #include <sys/queue.h>
33 #include <sys/lock.h>
34 #include <sys/sx.h>
35 
36 #include <net/if.h>
37 #include <net/if_arp.h>
38 #include <net/ethernet.h>
39 #include <net/if_dl.h>
40 #include <net/if_media.h>
41 
42 #include <net/bpf.h>
43 
44 #include <net/if_types.h>
45 #include <net/if.h>
46 
47 #include <netinet/in_systm.h>
48 #include <netinet/in.h>
49 #include <netinet/ip.h>
50 #include <netinet/if_ether.h>
51 #if __FreeBSD_version >= 700000
52 #include <netinet/tcp.h>
53 #include <netinet/tcp_lro.h>
54 #endif
55 
56 #include <vm/vm.h>
57 #include <vm/pmap.h>
58 
59 #include <machine/clock.h>      /* for DELAY */
60 #include <machine/bus.h>
61 #include <machine/resource.h>
62 #include <machine/frame.h>
63 #include <machine/vmparam.h>
64 
65 #include <sys/bus.h>
66 #include <sys/rman.h>
67 
68 #include <machine/intr_machdep.h>
69 
70 #include <machine/xen/xen-os.h>
71 #include <machine/xen/xenfunc.h>
72 #include <xen/hypervisor.h>
73 #include <xen/xen_intr.h>
74 #include <xen/evtchn.h>
75 #include <xen/gnttab.h>
76 #include <xen/interface/memory.h>
77 #include <xen/interface/io/netif.h>
78 #include <xen/xenbus/xenbusvar.h>
79 
80 #include <dev/xen/netfront/mbufq.h>
81 
82 #include "xenbus_if.h"
83 
84 #define XN_CSUM_FEATURES	(CSUM_TCP | CSUM_UDP | CSUM_TSO)
85 
86 #define GRANT_INVALID_REF	0
87 
88 #define NET_TX_RING_SIZE __RING_SIZE((netif_tx_sring_t *)0, PAGE_SIZE)
89 #define NET_RX_RING_SIZE __RING_SIZE((netif_rx_sring_t *)0, PAGE_SIZE)
90 
91 #if __FreeBSD_version >= 700000
92 /*
93  * Should the driver do LRO on the RX end
94  *  this can be toggled on the fly, but the
95  *  interface must be reset (down/up) for it
96  *  to take effect.
97  */
98 static int xn_enable_lro = 1;
99 TUNABLE_INT("hw.xn.enable_lro", &xn_enable_lro);
100 #else
101 
102 #define IFCAP_TSO4	0
103 #define CSUM_TSO	0
104 
105 #endif
106 
107 #ifdef CONFIG_XEN
108 static int MODPARM_rx_copy = 0;
109 module_param_named(rx_copy, MODPARM_rx_copy, bool, 0);
110 MODULE_PARM_DESC(rx_copy, "Copy packets from network card (rather than flip)");
111 static int MODPARM_rx_flip = 0;
112 module_param_named(rx_flip, MODPARM_rx_flip, bool, 0);
113 MODULE_PARM_DESC(rx_flip, "Flip packets from network card (rather than copy)");
114 #else
115 static const int MODPARM_rx_copy = 1;
116 static const int MODPARM_rx_flip = 0;
117 #endif
118 
119 #define MAX_SKB_FRAGS	(65536/PAGE_SIZE + 2)
120 #define RX_COPY_THRESHOLD 256
121 
122 #define net_ratelimit() 0
123 
124 struct netfront_info;
125 struct netfront_rx_info;
126 
127 static void xn_txeof(struct netfront_info *);
128 static void xn_rxeof(struct netfront_info *);
129 static void network_alloc_rx_buffers(struct netfront_info *);
130 
131 static void xn_tick_locked(struct netfront_info *);
132 static void xn_tick(void *);
133 
134 static void xn_intr(void *);
135 static void xn_start_locked(struct ifnet *);
136 static void xn_start(struct ifnet *);
137 static int  xn_ioctl(struct ifnet *, u_long, caddr_t);
138 static void xn_ifinit_locked(struct netfront_info *);
139 static void xn_ifinit(void *);
140 static void xn_stop(struct netfront_info *);
141 #ifdef notyet
142 static void xn_watchdog(struct ifnet *);
143 #endif
144 
145 static void show_device(struct netfront_info *sc);
146 #ifdef notyet
147 static void netfront_closing(device_t dev);
148 #endif
149 static void netif_free(struct netfront_info *info);
150 static int netfront_detach(device_t dev);
151 
152 static int talk_to_backend(device_t dev, struct netfront_info *info);
153 static int create_netdev(device_t dev);
154 static void netif_disconnect_backend(struct netfront_info *info);
155 static int setup_device(device_t dev, struct netfront_info *info);
156 static void end_access(int ref, void *page);
157 
158 /* Xenolinux helper functions */
159 int network_connect(struct netfront_info *);
160 
161 static void xn_free_rx_ring(struct netfront_info *);
162 
163 static void xn_free_tx_ring(struct netfront_info *);
164 
165 static int xennet_get_responses(struct netfront_info *np,
166 	struct netfront_rx_info *rinfo, RING_IDX rp, struct mbuf **list,
167 	int *pages_flipped_p);
168 
169 #define virt_to_mfn(x) (vtomach(x) >> PAGE_SHIFT)
170 
171 #define INVALID_P2M_ENTRY (~0UL)
172 
173 /*
174  * Mbuf pointers. We need these to keep track of the virtual addresses
175  * of our mbuf chains since we can only convert from virtual to physical,
176  * not the other way around.  The size must track the free index arrays.
177  */
178 struct xn_chain_data {
179 		struct mbuf		*xn_tx_chain[NET_TX_RING_SIZE+1];
180 		int			xn_tx_chain_cnt;
181 		struct mbuf		*xn_rx_chain[NET_RX_RING_SIZE+1];
182 };
183 
184 
185 struct net_device_stats
186 {
187 	u_long	rx_packets;		/* total packets received	*/
188 	u_long	tx_packets;		/* total packets transmitted	*/
189 	u_long	rx_bytes;		/* total bytes received 	*/
190 	u_long	tx_bytes;		/* total bytes transmitted	*/
191 	u_long	rx_errors;		/* bad packets received		*/
192 	u_long	tx_errors;		/* packet transmit problems	*/
193 	u_long	rx_dropped;		/* no space in linux buffers	*/
194 	u_long	tx_dropped;		/* no space available in linux	*/
195 	u_long	multicast;		/* multicast packets received	*/
196 	u_long	collisions;
197 
198 	/* detailed rx_errors: */
199 	u_long	rx_length_errors;
200 	u_long	rx_over_errors;		/* receiver ring buff overflow	*/
201 	u_long	rx_crc_errors;		/* recved pkt with crc error	*/
202 	u_long	rx_frame_errors;	/* recv'd frame alignment error */
203 	u_long	rx_fifo_errors;		/* recv'r fifo overrun		*/
204 	u_long	rx_missed_errors;	/* receiver missed packet	*/
205 
206 	/* detailed tx_errors */
207 	u_long	tx_aborted_errors;
208 	u_long	tx_carrier_errors;
209 	u_long	tx_fifo_errors;
210 	u_long	tx_heartbeat_errors;
211 	u_long	tx_window_errors;
212 
213 	/* for cslip etc */
214 	u_long	rx_compressed;
215 	u_long	tx_compressed;
216 };
217 
218 struct netfront_info {
219 
220 	struct ifnet *xn_ifp;
221 #if __FreeBSD_version >= 700000
222 	struct lro_ctrl xn_lro;
223 #endif
224 
225 	struct net_device_stats stats;
226 	u_int tx_full;
227 
228 	netif_tx_front_ring_t tx;
229 	netif_rx_front_ring_t rx;
230 
231 	struct mtx   tx_lock;
232 	struct mtx   rx_lock;
233 	struct sx    sc_lock;
234 
235 	u_int handle;
236 	u_int irq;
237 	u_int copying_receiver;
238 	u_int carrier;
239 
240 	/* Receive-ring batched refills. */
241 #define RX_MIN_TARGET 32
242 #define RX_MAX_TARGET NET_RX_RING_SIZE
243 	int rx_min_target, rx_max_target, rx_target;
244 
245 	/*
246 	 * {tx,rx}_skbs store outstanding skbuffs. The first entry in each
247 	 * array is an index into a chain of free entries.
248 	 */
249 
250 	grant_ref_t gref_tx_head;
251 	grant_ref_t grant_tx_ref[NET_TX_RING_SIZE + 1];
252 	grant_ref_t gref_rx_head;
253 	grant_ref_t grant_rx_ref[NET_TX_RING_SIZE + 1];
254 
255 #define TX_MAX_TARGET min(NET_RX_RING_SIZE, 256)
256 	device_t xbdev;
257 	int tx_ring_ref;
258 	int rx_ring_ref;
259 	uint8_t mac[ETHER_ADDR_LEN];
260 	struct xn_chain_data	xn_cdata;	/* mbufs */
261 	struct mbuf_head xn_rx_batch;	/* head of the batch queue */
262 
263 	int			xn_if_flags;
264 	struct callout	        xn_stat_ch;
265 
266 	u_long rx_pfn_array[NET_RX_RING_SIZE];
267 	multicall_entry_t rx_mcl[NET_RX_RING_SIZE+1];
268 	mmu_update_t rx_mmu[NET_RX_RING_SIZE];
269 };
270 
271 #define rx_mbufs xn_cdata.xn_rx_chain
272 #define tx_mbufs xn_cdata.xn_tx_chain
273 
274 #define XN_LOCK_INIT(_sc, _name) \
275         mtx_init(&(_sc)->tx_lock, #_name"_tx", "network transmit lock", MTX_DEF); \
276         mtx_init(&(_sc)->rx_lock, #_name"_rx", "network receive lock", MTX_DEF);  \
277         sx_init(&(_sc)->sc_lock, #_name"_rx")
278 
279 #define XN_RX_LOCK(_sc)           mtx_lock(&(_sc)->rx_lock)
280 #define XN_RX_UNLOCK(_sc)         mtx_unlock(&(_sc)->rx_lock)
281 
282 #define XN_TX_LOCK(_sc)           mtx_lock(&(_sc)->tx_lock)
283 #define XN_TX_UNLOCK(_sc)         mtx_unlock(&(_sc)->tx_lock)
284 
285 #define XN_LOCK(_sc)           sx_xlock(&(_sc)->sc_lock);
286 #define XN_UNLOCK(_sc)         sx_xunlock(&(_sc)->sc_lock);
287 
288 #define XN_LOCK_ASSERT(_sc)    sx_assert(&(_sc)->sc_lock, SX_LOCKED);
289 #define XN_RX_LOCK_ASSERT(_sc)    mtx_assert(&(_sc)->rx_lock, MA_OWNED);
290 #define XN_TX_LOCK_ASSERT(_sc)    mtx_assert(&(_sc)->tx_lock, MA_OWNED);
291 #define XN_LOCK_DESTROY(_sc)   mtx_destroy(&(_sc)->rx_lock); \
292                                mtx_destroy(&(_sc)->tx_lock); \
293                                sx_destroy(&(_sc)->sc_lock);
294 
295 struct netfront_rx_info {
296 	struct netif_rx_response rx;
297 	struct netif_extra_info extras[XEN_NETIF_EXTRA_TYPE_MAX - 1];
298 };
299 
300 #define netfront_carrier_on(netif)	((netif)->carrier = 1)
301 #define netfront_carrier_off(netif)	((netif)->carrier = 0)
302 #define netfront_carrier_ok(netif)	((netif)->carrier)
303 
304 /* Access macros for acquiring freeing slots in xn_free_{tx,rx}_idxs[]. */
305 
306 
307 
308 /*
309  * Access macros for acquiring freeing slots in tx_skbs[].
310  */
311 
312 static inline void
313 add_id_to_freelist(struct mbuf **list, unsigned short id)
314 {
315 	KASSERT(id != 0, ("add_id_to_freelist: the head item (0) must always be free."));
316 	list[id] = list[0];
317 	list[0]  = (void *)(u_long)id;
318 }
319 
320 static inline unsigned short
321 get_id_from_freelist(struct mbuf **list)
322 {
323 	u_int id = (u_int)(u_long)list[0];
324 	KASSERT(id != 0, ("get_id_from_freelist: the head item (0) must always remain free."));
325 	list[0] = list[id];
326 	return (id);
327 }
328 
329 static inline int
330 xennet_rxidx(RING_IDX idx)
331 {
332 	return idx & (NET_RX_RING_SIZE - 1);
333 }
334 
335 static inline struct mbuf *
336 xennet_get_rx_mbuf(struct netfront_info *np,
337 						RING_IDX ri)
338 {
339 	int i = xennet_rxidx(ri);
340 	struct mbuf *m;
341 
342 	m = np->rx_mbufs[i];
343 	np->rx_mbufs[i] = NULL;
344 	return (m);
345 }
346 
347 static inline grant_ref_t
348 xennet_get_rx_ref(struct netfront_info *np, RING_IDX ri)
349 {
350 	int i = xennet_rxidx(ri);
351 	grant_ref_t ref = np->grant_rx_ref[i];
352 	np->grant_rx_ref[i] = GRANT_INVALID_REF;
353 	return ref;
354 }
355 
356 #define IPRINTK(fmt, args...) \
357     printf("[XEN] " fmt, ##args)
358 #define WPRINTK(fmt, args...) \
359     printf("[XEN] " fmt, ##args)
360 #if 0
361 #define DPRINTK(fmt, args...) \
362     printf("[XEN] %s: " fmt, __func__, ##args)
363 #else
364 #define DPRINTK(fmt, args...)
365 #endif
366 
367 /**
368  * Read the 'mac' node at the given device's node in the store, and parse that
369  * as colon-separated octets, placing result the given mac array.  mac must be
370  * a preallocated array of length ETH_ALEN (as declared in linux/if_ether.h).
371  * Return 0 on success, or errno on error.
372  */
373 static int
374 xen_net_read_mac(device_t dev, uint8_t mac[])
375 {
376 	int error, i;
377 	char *s, *e, *macstr;
378 
379 	error = xenbus_read(XBT_NIL, xenbus_get_node(dev), "mac", NULL,
380 	    (void **) &macstr);
381 	if (error)
382 		return (error);
383 
384 	s = macstr;
385 	for (i = 0; i < ETHER_ADDR_LEN; i++) {
386 		mac[i] = strtoul(s, &e, 16);
387 		if (s == e || (e[0] != ':' && e[0] != 0)) {
388 			free(macstr, M_DEVBUF);
389 			return (ENOENT);
390 		}
391 		s = &e[1];
392 	}
393 	free(macstr, M_DEVBUF);
394 	return (0);
395 }
396 
397 /**
398  * Entry point to this code when a new device is created.  Allocate the basic
399  * structures and the ring buffers for communication with the backend, and
400  * inform the backend of the appropriate details for those.  Switch to
401  * Connected state.
402  */
403 static int
404 netfront_probe(device_t dev)
405 {
406 
407 	if (!strcmp(xenbus_get_type(dev), "vif")) {
408 		device_set_desc(dev, "Virtual Network Interface");
409 		return (0);
410 	}
411 
412 	return (ENXIO);
413 }
414 
415 static int
416 netfront_attach(device_t dev)
417 {
418 	int err;
419 
420 	err = create_netdev(dev);
421 	if (err) {
422 		xenbus_dev_fatal(dev, err, "creating netdev");
423 		return err;
424 	}
425 
426 #if __FreeBSD_version >= 700000
427 	SYSCTL_ADD_INT(device_get_sysctl_ctx(dev),
428 	    SYSCTL_CHILDREN(device_get_sysctl_tree(dev)),
429 	    OID_AUTO, "enable_lro", CTLTYPE_INT|CTLFLAG_RW,
430 	    &xn_enable_lro, 0, "Large Receive Offload");
431 #endif
432 
433 	return 0;
434 }
435 
436 
437 /**
438  * We are reconnecting to the backend, due to a suspend/resume, or a backend
439  * driver restart.  We tear down our netif structure and recreate it, but
440  * leave the device-layer structures intact so that this is transparent to the
441  * rest of the kernel.
442  */
443 static int
444 netfront_resume(device_t dev)
445 {
446 	struct netfront_info *info = device_get_softc(dev);
447 
448 	netif_disconnect_backend(info);
449 	return (0);
450 }
451 
452 
453 /* Common code used when first setting up, and when resuming. */
454 static int
455 talk_to_backend(device_t dev, struct netfront_info *info)
456 {
457 	const char *message;
458 	struct xenbus_transaction xbt;
459 	const char *node = xenbus_get_node(dev);
460 	int err;
461 
462 	err = xen_net_read_mac(dev, info->mac);
463 	if (err) {
464 		xenbus_dev_fatal(dev, err, "parsing %s/mac", node);
465 		goto out;
466 	}
467 
468 	/* Create shared ring, alloc event channel. */
469 	err = setup_device(dev, info);
470 	if (err)
471 		goto out;
472 
473  again:
474 	err = xenbus_transaction_start(&xbt);
475 	if (err) {
476 		xenbus_dev_fatal(dev, err, "starting transaction");
477 		goto destroy_ring;
478 	}
479 	err = xenbus_printf(xbt, node, "tx-ring-ref","%u",
480 			    info->tx_ring_ref);
481 	if (err) {
482 		message = "writing tx ring-ref";
483 		goto abort_transaction;
484 	}
485 	err = xenbus_printf(xbt, node, "rx-ring-ref","%u",
486 			    info->rx_ring_ref);
487 	if (err) {
488 		message = "writing rx ring-ref";
489 		goto abort_transaction;
490 	}
491 	err = xenbus_printf(xbt, node,
492 		"event-channel", "%u", irq_to_evtchn_port(info->irq));
493 	if (err) {
494 		message = "writing event-channel";
495 		goto abort_transaction;
496 	}
497 	err = xenbus_printf(xbt, node, "request-rx-copy", "%u",
498 			    info->copying_receiver);
499 	if (err) {
500 		message = "writing request-rx-copy";
501 		goto abort_transaction;
502 	}
503 	err = xenbus_printf(xbt, node, "feature-rx-notify", "%d", 1);
504 	if (err) {
505 		message = "writing feature-rx-notify";
506 		goto abort_transaction;
507 	}
508 	err = xenbus_printf(xbt, node, "feature-sg", "%d", 1);
509 	if (err) {
510 		message = "writing feature-sg";
511 		goto abort_transaction;
512 	}
513 #if __FreeBSD_version >= 700000
514 	err = xenbus_printf(xbt, node, "feature-gso-tcpv4", "%d", 1);
515 	if (err) {
516 		message = "writing feature-gso-tcpv4";
517 		goto abort_transaction;
518 	}
519 #endif
520 
521 	err = xenbus_transaction_end(xbt, 0);
522 	if (err) {
523 		if (err == EAGAIN)
524 			goto again;
525 		xenbus_dev_fatal(dev, err, "completing transaction");
526 		goto destroy_ring;
527 	}
528 
529 	return 0;
530 
531  abort_transaction:
532 	xenbus_transaction_end(xbt, 1);
533 	xenbus_dev_fatal(dev, err, "%s", message);
534  destroy_ring:
535 	netif_free(info);
536  out:
537 	return err;
538 }
539 
540 
541 static int
542 setup_device(device_t dev, struct netfront_info *info)
543 {
544 	netif_tx_sring_t *txs;
545 	netif_rx_sring_t *rxs;
546 	int error;
547 	struct ifnet *ifp;
548 
549 	ifp = info->xn_ifp;
550 
551 	info->tx_ring_ref = GRANT_INVALID_REF;
552 	info->rx_ring_ref = GRANT_INVALID_REF;
553 	info->rx.sring = NULL;
554 	info->tx.sring = NULL;
555 	info->irq = 0;
556 
557 	txs = (netif_tx_sring_t *)malloc(PAGE_SIZE, M_DEVBUF, M_NOWAIT|M_ZERO);
558 	if (!txs) {
559 		error = ENOMEM;
560 		xenbus_dev_fatal(dev, error, "allocating tx ring page");
561 		goto fail;
562 	}
563 	SHARED_RING_INIT(txs);
564 	FRONT_RING_INIT(&info->tx, txs, PAGE_SIZE);
565 	error = xenbus_grant_ring(dev, virt_to_mfn(txs), &info->tx_ring_ref);
566 	if (error)
567 		goto fail;
568 
569 	rxs = (netif_rx_sring_t *)malloc(PAGE_SIZE, M_DEVBUF, M_NOWAIT|M_ZERO);
570 	if (!rxs) {
571 		error = ENOMEM;
572 		xenbus_dev_fatal(dev, error, "allocating rx ring page");
573 		goto fail;
574 	}
575 	SHARED_RING_INIT(rxs);
576 	FRONT_RING_INIT(&info->rx, rxs, PAGE_SIZE);
577 
578 	error = xenbus_grant_ring(dev, virt_to_mfn(rxs), &info->rx_ring_ref);
579 	if (error)
580 		goto fail;
581 
582 	error = bind_listening_port_to_irqhandler(xenbus_get_otherend_id(dev),
583 	    "xn", xn_intr, info, INTR_TYPE_NET | INTR_MPSAFE, &info->irq);
584 
585 	if (error) {
586 		xenbus_dev_fatal(dev, error,
587 				 "bind_evtchn_to_irqhandler failed");
588 		goto fail;
589 	}
590 
591 	show_device(info);
592 
593 	return (0);
594 
595  fail:
596 	netif_free(info);
597 	return (error);
598 }
599 
600 /**
601  * If this interface has an ipv4 address, send an arp for it. This
602  * helps to get the network going again after migrating hosts.
603  */
604 static void
605 netfront_send_fake_arp(device_t dev, struct netfront_info *info)
606 {
607 	struct ifnet *ifp;
608 	struct ifaddr *ifa;
609 
610 	ifp = info->xn_ifp;
611 	TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
612 		if (ifa->ifa_addr->sa_family == AF_INET) {
613 			arp_ifinit(ifp, ifa);
614 		}
615 	}
616 }
617 
618 /**
619  * Callback received when the backend's state changes.
620  */
621 static int
622 netfront_backend_changed(device_t dev, XenbusState newstate)
623 {
624 	struct netfront_info *sc = device_get_softc(dev);
625 
626 	DPRINTK("newstate=%d\n", newstate);
627 
628 	switch (newstate) {
629 	case XenbusStateInitialising:
630 	case XenbusStateInitialised:
631 	case XenbusStateConnected:
632 	case XenbusStateUnknown:
633 	case XenbusStateClosed:
634 	case XenbusStateReconfigured:
635 	case XenbusStateReconfiguring:
636 		break;
637 	case XenbusStateInitWait:
638 		if (xenbus_get_state(dev) != XenbusStateInitialising)
639 			break;
640 		if (network_connect(sc) != 0)
641 			break;
642 		xenbus_set_state(dev, XenbusStateConnected);
643 		netfront_send_fake_arp(dev, sc);
644 		break;
645 	case XenbusStateClosing:
646 		xenbus_set_state(dev, XenbusStateClosed);
647 		break;
648 	}
649 	return (0);
650 }
651 
652 static void
653 xn_free_rx_ring(struct netfront_info *sc)
654 {
655 #if 0
656 	int i;
657 
658 	for (i = 0; i < NET_RX_RING_SIZE; i++) {
659 		if (sc->xn_cdata.xn_rx_chain[i] != NULL) {
660 			m_freem(sc->xn_cdata.xn_rx_chain[i]);
661 			sc->xn_cdata.xn_rx_chain[i] = NULL;
662 		}
663 	}
664 
665 	sc->rx.rsp_cons = 0;
666 	sc->xn_rx_if->req_prod = 0;
667 	sc->xn_rx_if->event = sc->rx.rsp_cons ;
668 #endif
669 }
670 
671 static void
672 xn_free_tx_ring(struct netfront_info *sc)
673 {
674 #if 0
675 	int i;
676 
677 	for (i = 0; i < NET_TX_RING_SIZE; i++) {
678 		if (sc->xn_cdata.xn_tx_chain[i] != NULL) {
679 			m_freem(sc->xn_cdata.xn_tx_chain[i]);
680 			sc->xn_cdata.xn_tx_chain[i] = NULL;
681 		}
682 	}
683 
684 	return;
685 #endif
686 }
687 
688 /*
689  * Do some brief math on the number of descriptors available to
690  * determine how many slots are available.
691  *
692  * Firstly - wouldn't something with RING_FREE_REQUESTS() be more applicable?
693  * Secondly - MAX_SKB_FRAGS is a Linux construct which may not apply here.
694  * Thirdly - it isn't used here anyway; the magic constant '24' is possibly
695  *   wrong?
696  * The "2" is presumably to ensure there are also enough slots available for
697  * the ring entries used for "options" (eg, the TSO entry before a packet
698  * is queued); I'm not sure why its 2 and not 1. Perhaps to make sure there's
699  * a "free" node in the tx mbuf list (node 0) to represent the freelist?
700  *
701  * This only figures out whether any xenbus ring descriptors are available;
702  * it doesn't at all reflect how many tx mbuf ring descriptors are also
703  * available.
704  */
705 static inline int
706 netfront_tx_slot_available(struct netfront_info *np)
707 {
708 	return ((np->tx.req_prod_pvt - np->tx.rsp_cons) <
709 		(TX_MAX_TARGET - /* MAX_SKB_FRAGS */ 24 - 2));
710 }
711 static void
712 netif_release_tx_bufs(struct netfront_info *np)
713 {
714 	struct mbuf *m;
715 	int i;
716 
717 	for (i = 1; i <= NET_TX_RING_SIZE; i++) {
718 		m = np->xn_cdata.xn_tx_chain[i];
719 
720 		if (((u_long)m) < KERNBASE)
721 			continue;
722 		gnttab_grant_foreign_access_ref(np->grant_tx_ref[i],
723 		    xenbus_get_otherend_id(np->xbdev),
724 		    virt_to_mfn(mtod(m, vm_offset_t)),
725 		    GNTMAP_readonly);
726 		gnttab_release_grant_reference(&np->gref_tx_head,
727 		    np->grant_tx_ref[i]);
728 		np->grant_tx_ref[i] = GRANT_INVALID_REF;
729 		add_id_to_freelist(np->tx_mbufs, i);
730 		np->xn_cdata.xn_tx_chain_cnt--;
731 		if (np->xn_cdata.xn_tx_chain_cnt < 0) {
732 			panic("netif_release_tx_bufs: tx_chain_cnt must be >= 0");
733 		}
734 		m_freem(m);
735 	}
736 }
737 
738 static void
739 network_alloc_rx_buffers(struct netfront_info *sc)
740 {
741 	int otherend_id = xenbus_get_otherend_id(sc->xbdev);
742 	unsigned short id;
743 	struct mbuf *m_new;
744 	int i, batch_target, notify;
745 	RING_IDX req_prod;
746 	struct xen_memory_reservation reservation;
747 	grant_ref_t ref;
748 	int nr_flips;
749 	netif_rx_request_t *req;
750 	vm_offset_t vaddr;
751 	u_long pfn;
752 
753 	req_prod = sc->rx.req_prod_pvt;
754 
755 	if (unlikely(sc->carrier == 0))
756 		return;
757 
758 	/*
759 	 * Allocate skbuffs greedily, even though we batch updates to the
760 	 * receive ring. This creates a less bursty demand on the memory
761 	 * allocator, so should reduce the chance of failed allocation
762 	 * requests both for ourself and for other kernel subsystems.
763 	 */
764 	batch_target = sc->rx_target - (req_prod - sc->rx.rsp_cons);
765 	for (i = mbufq_len(&sc->xn_rx_batch); i < batch_target; i++) {
766 		MGETHDR(m_new, M_DONTWAIT, MT_DATA);
767 		if (m_new == NULL)
768 			goto no_mbuf;
769 
770 		m_cljget(m_new, M_DONTWAIT, MJUMPAGESIZE);
771 		if ((m_new->m_flags & M_EXT) == 0) {
772 			m_freem(m_new);
773 
774 no_mbuf:
775 			if (i != 0)
776 				goto refill;
777 			/*
778 			 * XXX set timer
779 			 */
780 			break;
781 		}
782 		m_new->m_len = m_new->m_pkthdr.len = MJUMPAGESIZE;
783 
784 		/* queue the mbufs allocated */
785 		mbufq_tail(&sc->xn_rx_batch, m_new);
786 	}
787 
788 	/* Is the batch large enough to be worthwhile? */
789 	if (i < (sc->rx_target/2)) {
790 		if (req_prod >sc->rx.sring->req_prod)
791 			goto push;
792 		return;
793 	}
794 	/* Adjust floating fill target if we risked running out of buffers. */
795 	if ( ((req_prod - sc->rx.sring->rsp_prod) < (sc->rx_target / 4)) &&
796 	     ((sc->rx_target *= 2) > sc->rx_max_target) )
797 		sc->rx_target = sc->rx_max_target;
798 
799 refill:
800 	for (nr_flips = i = 0; ; i++) {
801 		if ((m_new = mbufq_dequeue(&sc->xn_rx_batch)) == NULL)
802 			break;
803 
804 		m_new->m_ext.ext_arg1 = (vm_paddr_t *)(uintptr_t)(
805 				vtophys(m_new->m_ext.ext_buf) >> PAGE_SHIFT);
806 
807 		id = xennet_rxidx(req_prod + i);
808 
809 		KASSERT(sc->xn_cdata.xn_rx_chain[id] == NULL,
810 		    ("non-NULL xm_rx_chain"));
811 		sc->xn_cdata.xn_rx_chain[id] = m_new;
812 
813 		ref = gnttab_claim_grant_reference(&sc->gref_rx_head);
814 		KASSERT((short)ref >= 0, ("negative ref"));
815 		sc->grant_rx_ref[id] = ref;
816 
817 		vaddr = mtod(m_new, vm_offset_t);
818 		pfn = vtophys(vaddr) >> PAGE_SHIFT;
819 		req = RING_GET_REQUEST(&sc->rx, req_prod + i);
820 
821 		if (sc->copying_receiver == 0) {
822 			gnttab_grant_foreign_transfer_ref(ref,
823 			    otherend_id, pfn);
824 			sc->rx_pfn_array[nr_flips] = PFNTOMFN(pfn);
825 			if (!xen_feature(XENFEAT_auto_translated_physmap)) {
826 				/* Remove this page before passing
827 				 * back to Xen.
828 				 */
829 				set_phys_to_machine(pfn, INVALID_P2M_ENTRY);
830 				MULTI_update_va_mapping(&sc->rx_mcl[i],
831 				    vaddr, 0, 0);
832 			}
833 			nr_flips++;
834 		} else {
835 			gnttab_grant_foreign_access_ref(ref,
836 			    otherend_id,
837 			    PFNTOMFN(pfn), 0);
838 		}
839 		req->id = id;
840 		req->gref = ref;
841 
842 		sc->rx_pfn_array[i] =
843 		    vtomach(mtod(m_new,vm_offset_t)) >> PAGE_SHIFT;
844 	}
845 
846 	KASSERT(i, ("no mbufs processed")); /* should have returned earlier */
847 	KASSERT(mbufq_len(&sc->xn_rx_batch) == 0, ("not all mbufs processed"));
848 	/*
849 	 * We may have allocated buffers which have entries outstanding
850 	 * in the page * update queue -- make sure we flush those first!
851 	 */
852 	PT_UPDATES_FLUSH();
853 	if (nr_flips != 0) {
854 #ifdef notyet
855 		/* Tell the ballon driver what is going on. */
856 		balloon_update_driver_allowance(i);
857 #endif
858 		set_xen_guest_handle(reservation.extent_start, sc->rx_pfn_array);
859 		reservation.nr_extents   = i;
860 		reservation.extent_order = 0;
861 		reservation.address_bits = 0;
862 		reservation.domid        = DOMID_SELF;
863 
864 		if (!xen_feature(XENFEAT_auto_translated_physmap)) {
865 
866 			/* After all PTEs have been zapped, flush the TLB. */
867 			sc->rx_mcl[i-1].args[MULTI_UVMFLAGS_INDEX] =
868 			    UVMF_TLB_FLUSH|UVMF_ALL;
869 
870 			/* Give away a batch of pages. */
871 			sc->rx_mcl[i].op = __HYPERVISOR_memory_op;
872 			sc->rx_mcl[i].args[0] = XENMEM_decrease_reservation;
873 			sc->rx_mcl[i].args[1] =  (u_long)&reservation;
874 			/* Zap PTEs and give away pages in one big multicall. */
875 			(void)HYPERVISOR_multicall(sc->rx_mcl, i+1);
876 
877 			/* Check return status of HYPERVISOR_dom_mem_op(). */
878 			if (unlikely(sc->rx_mcl[i].result != i))
879 				panic("Unable to reduce memory reservation\n");
880 			} else {
881 				if (HYPERVISOR_memory_op(
882 				    XENMEM_decrease_reservation, &reservation)
883 				    != i)
884 					panic("Unable to reduce memory "
885 					    "reservation\n");
886 		}
887 	} else {
888 		wmb();
889 	}
890 
891 	/* Above is a suitable barrier to ensure backend will see requests. */
892 	sc->rx.req_prod_pvt = req_prod + i;
893 push:
894 	RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&sc->rx, notify);
895 	if (notify)
896 		notify_remote_via_irq(sc->irq);
897 }
898 
899 static void
900 xn_rxeof(struct netfront_info *np)
901 {
902 	struct ifnet *ifp;
903 #if __FreeBSD_version >= 700000
904 	struct lro_ctrl *lro = &np->xn_lro;
905 	struct lro_entry *queued;
906 #endif
907 	struct netfront_rx_info rinfo;
908 	struct netif_rx_response *rx = &rinfo.rx;
909 	struct netif_extra_info *extras = rinfo.extras;
910 	RING_IDX i, rp;
911 	multicall_entry_t *mcl;
912 	struct mbuf *m;
913 	struct mbuf_head rxq, errq;
914 	int err, pages_flipped = 0, work_to_do;
915 
916 	do {
917 		XN_RX_LOCK_ASSERT(np);
918 		if (!netfront_carrier_ok(np))
919 			return;
920 
921 		mbufq_init(&errq);
922 		mbufq_init(&rxq);
923 
924 		ifp = np->xn_ifp;
925 
926 		rp = np->rx.sring->rsp_prod;
927 		rmb();	/* Ensure we see queued responses up to 'rp'. */
928 
929 		i = np->rx.rsp_cons;
930 		while ((i != rp)) {
931 			memcpy(rx, RING_GET_RESPONSE(&np->rx, i), sizeof(*rx));
932 			memset(extras, 0, sizeof(rinfo.extras));
933 
934 			m = NULL;
935 			err = xennet_get_responses(np, &rinfo, rp, &m,
936 			    &pages_flipped);
937 
938 			if (unlikely(err)) {
939 				if (m)
940 					mbufq_tail(&errq, m);
941 				np->stats.rx_errors++;
942 				i = np->rx.rsp_cons;
943 				continue;
944 			}
945 
946 			m->m_pkthdr.rcvif = ifp;
947 			if ( rx->flags & NETRXF_data_validated ) {
948 				/* Tell the stack the checksums are okay */
949 				/*
950 				 * XXX this isn't necessarily the case - need to add
951 				 * check
952 				 */
953 
954 				m->m_pkthdr.csum_flags |=
955 					(CSUM_IP_CHECKED | CSUM_IP_VALID | CSUM_DATA_VALID
956 					    | CSUM_PSEUDO_HDR);
957 				m->m_pkthdr.csum_data = 0xffff;
958 			}
959 
960 			np->stats.rx_packets++;
961 			np->stats.rx_bytes += m->m_pkthdr.len;
962 
963 			mbufq_tail(&rxq, m);
964 			np->rx.rsp_cons = ++i;
965 		}
966 
967 		if (pages_flipped) {
968 			/* Some pages are no longer absent... */
969 #ifdef notyet
970 			balloon_update_driver_allowance(-pages_flipped);
971 #endif
972 			/* Do all the remapping work, and M->P updates, in one big
973 			 * hypercall.
974 			 */
975 			if (!!xen_feature(XENFEAT_auto_translated_physmap)) {
976 				mcl = np->rx_mcl + pages_flipped;
977 				mcl->op = __HYPERVISOR_mmu_update;
978 				mcl->args[0] = (u_long)np->rx_mmu;
979 				mcl->args[1] = pages_flipped;
980 				mcl->args[2] = 0;
981 				mcl->args[3] = DOMID_SELF;
982 				(void)HYPERVISOR_multicall(np->rx_mcl,
983 				    pages_flipped + 1);
984 			}
985 		}
986 
987 		while ((m = mbufq_dequeue(&errq)))
988 			m_freem(m);
989 
990 		/*
991 		 * Process all the mbufs after the remapping is complete.
992 		 * Break the mbuf chain first though.
993 		 */
994 		while ((m = mbufq_dequeue(&rxq)) != NULL) {
995 			ifp->if_ipackets++;
996 
997 			/*
998 			 * Do we really need to drop the rx lock?
999 			 */
1000 			XN_RX_UNLOCK(np);
1001 #if __FreeBSD_version >= 700000
1002 			/* Use LRO if possible */
1003 			if ((ifp->if_capenable & IFCAP_LRO) == 0 ||
1004 			    lro->lro_cnt == 0 || tcp_lro_rx(lro, m, 0)) {
1005 				/*
1006 				 * If LRO fails, pass up to the stack
1007 				 * directly.
1008 				 */
1009 				(*ifp->if_input)(ifp, m);
1010 			}
1011 #else
1012 			(*ifp->if_input)(ifp, m);
1013 #endif
1014 			XN_RX_LOCK(np);
1015 		}
1016 
1017 		np->rx.rsp_cons = i;
1018 
1019 #if __FreeBSD_version >= 700000
1020 		/*
1021 		 * Flush any outstanding LRO work
1022 		 */
1023 		while (!SLIST_EMPTY(&lro->lro_active)) {
1024 			queued = SLIST_FIRST(&lro->lro_active);
1025 			SLIST_REMOVE_HEAD(&lro->lro_active, next);
1026 			tcp_lro_flush(lro, queued);
1027 		}
1028 #endif
1029 
1030 #if 0
1031 		/* If we get a callback with very few responses, reduce fill target. */
1032 		/* NB. Note exponential increase, linear decrease. */
1033 		if (((np->rx.req_prod_pvt - np->rx.sring->rsp_prod) >
1034 			((3*np->rx_target) / 4)) && (--np->rx_target < np->rx_min_target))
1035 			np->rx_target = np->rx_min_target;
1036 #endif
1037 
1038 		network_alloc_rx_buffers(np);
1039 
1040 		RING_FINAL_CHECK_FOR_RESPONSES(&np->rx, work_to_do);
1041 	} while (work_to_do);
1042 }
1043 
1044 static void
1045 xn_txeof(struct netfront_info *np)
1046 {
1047 	RING_IDX i, prod;
1048 	unsigned short id;
1049 	struct ifnet *ifp;
1050 	netif_tx_response_t *txr;
1051 	struct mbuf *m;
1052 
1053 	XN_TX_LOCK_ASSERT(np);
1054 
1055 	if (!netfront_carrier_ok(np))
1056 		return;
1057 
1058 	ifp = np->xn_ifp;
1059 	ifp->if_timer = 0;
1060 
1061 	do {
1062 		prod = np->tx.sring->rsp_prod;
1063 		rmb(); /* Ensure we see responses up to 'rp'. */
1064 
1065 		for (i = np->tx.rsp_cons; i != prod; i++) {
1066 			txr = RING_GET_RESPONSE(&np->tx, i);
1067 			if (txr->status == NETIF_RSP_NULL)
1068 				continue;
1069 
1070 			id = txr->id;
1071 			m = np->xn_cdata.xn_tx_chain[id];
1072 			KASSERT(m != NULL, ("mbuf not found in xn_tx_chain"));
1073 			M_ASSERTVALID(m);
1074 
1075 			/*
1076 			 * Increment packet count if this is the last
1077 			 * mbuf of the chain.
1078 			 */
1079 			if (!m->m_next)
1080 				ifp->if_opackets++;
1081 			if (unlikely(gnttab_query_foreign_access(
1082 			    np->grant_tx_ref[id]) != 0)) {
1083 				printf("network_tx_buf_gc: warning "
1084 				    "-- grant still in use by backend "
1085 				    "domain.\n");
1086 				goto out;
1087 			}
1088 			gnttab_end_foreign_access_ref(
1089 				np->grant_tx_ref[id]);
1090 			gnttab_release_grant_reference(
1091 				&np->gref_tx_head, np->grant_tx_ref[id]);
1092 			np->grant_tx_ref[id] = GRANT_INVALID_REF;
1093 
1094 			np->xn_cdata.xn_tx_chain[id] = NULL;
1095 			add_id_to_freelist(np->xn_cdata.xn_tx_chain, id);
1096 			np->xn_cdata.xn_tx_chain_cnt--;
1097 			if (np->xn_cdata.xn_tx_chain_cnt < 0) {
1098 				panic("netif_release_tx_bufs: tx_chain_cnt must be >= 0");
1099 			}
1100 			m_free(m);
1101 			/* Only mark the queue active if we've freed up at least one slot to try */
1102 			ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1103 		}
1104 		np->tx.rsp_cons = prod;
1105 
1106 		/*
1107 		 * Set a new event, then check for race with update of
1108 		 * tx_cons. Note that it is essential to schedule a
1109 		 * callback, no matter how few buffers are pending. Even if
1110 		 * there is space in the transmit ring, higher layers may
1111 		 * be blocked because too much data is outstanding: in such
1112 		 * cases notification from Xen is likely to be the only kick
1113 		 * that we'll get.
1114 		 */
1115 		np->tx.sring->rsp_event =
1116 		    prod + ((np->tx.sring->req_prod - prod) >> 1) + 1;
1117 
1118 		mb();
1119 	} while (prod != np->tx.sring->rsp_prod);
1120 
1121  out:
1122 	if (np->tx_full &&
1123 	    ((np->tx.sring->req_prod - prod) < NET_TX_RING_SIZE)) {
1124 		np->tx_full = 0;
1125 #if 0
1126 		if (np->user_state == UST_OPEN)
1127 			netif_wake_queue(dev);
1128 #endif
1129 	}
1130 
1131 }
1132 
1133 static void
1134 xn_intr(void *xsc)
1135 {
1136 	struct netfront_info *np = xsc;
1137 	struct ifnet *ifp = np->xn_ifp;
1138 
1139 #if 0
1140 	if (!(np->rx.rsp_cons != np->rx.sring->rsp_prod &&
1141 	    likely(netfront_carrier_ok(np)) &&
1142 	    ifp->if_drv_flags & IFF_DRV_RUNNING))
1143 		return;
1144 #endif
1145 	if (np->tx.rsp_cons != np->tx.sring->rsp_prod) {
1146 		XN_TX_LOCK(np);
1147 		xn_txeof(np);
1148 		XN_TX_UNLOCK(np);
1149 	}
1150 
1151 	XN_RX_LOCK(np);
1152 	xn_rxeof(np);
1153 	XN_RX_UNLOCK(np);
1154 
1155 	if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
1156 	    !IFQ_DRV_IS_EMPTY(&ifp->if_snd))
1157 		xn_start(ifp);
1158 }
1159 
1160 
1161 static void
1162 xennet_move_rx_slot(struct netfront_info *np, struct mbuf *m,
1163 	grant_ref_t ref)
1164 {
1165 	int new = xennet_rxidx(np->rx.req_prod_pvt);
1166 
1167 	KASSERT(np->rx_mbufs[new] == NULL, ("rx_mbufs != NULL"));
1168 	np->rx_mbufs[new] = m;
1169 	np->grant_rx_ref[new] = ref;
1170 	RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->id = new;
1171 	RING_GET_REQUEST(&np->rx, np->rx.req_prod_pvt)->gref = ref;
1172 	np->rx.req_prod_pvt++;
1173 }
1174 
1175 static int
1176 xennet_get_extras(struct netfront_info *np,
1177     struct netif_extra_info *extras, RING_IDX rp)
1178 {
1179 	struct netif_extra_info *extra;
1180 	RING_IDX cons = np->rx.rsp_cons;
1181 
1182 	int err = 0;
1183 
1184 	do {
1185 		struct mbuf *m;
1186 		grant_ref_t ref;
1187 
1188 		if (unlikely(cons + 1 == rp)) {
1189 #if 0
1190 			if (net_ratelimit())
1191 				WPRINTK("Missing extra info\n");
1192 #endif
1193 			err = -EINVAL;
1194 			break;
1195 		}
1196 
1197 		extra = (struct netif_extra_info *)
1198 		RING_GET_RESPONSE(&np->rx, ++cons);
1199 
1200 		if (unlikely(!extra->type ||
1201 			extra->type >= XEN_NETIF_EXTRA_TYPE_MAX)) {
1202 #if 0
1203 			if (net_ratelimit())
1204 				WPRINTK("Invalid extra type: %d\n",
1205 					extra->type);
1206 #endif
1207 			err = -EINVAL;
1208 		} else {
1209 			memcpy(&extras[extra->type - 1], extra, sizeof(*extra));
1210 		}
1211 
1212 		m = xennet_get_rx_mbuf(np, cons);
1213 		ref = xennet_get_rx_ref(np, cons);
1214 		xennet_move_rx_slot(np, m, ref);
1215 	} while (extra->flags & XEN_NETIF_EXTRA_FLAG_MORE);
1216 
1217 	np->rx.rsp_cons = cons;
1218 	return err;
1219 }
1220 
1221 static int
1222 xennet_get_responses(struct netfront_info *np,
1223 	struct netfront_rx_info *rinfo, RING_IDX rp,
1224 	struct mbuf  **list,
1225 	int *pages_flipped_p)
1226 {
1227 	int pages_flipped = *pages_flipped_p;
1228 	struct mmu_update *mmu;
1229 	struct multicall_entry *mcl;
1230 	struct netif_rx_response *rx = &rinfo->rx;
1231 	struct netif_extra_info *extras = rinfo->extras;
1232 	RING_IDX cons = np->rx.rsp_cons;
1233 	struct mbuf *m, *m0, *m_prev;
1234 	grant_ref_t ref = xennet_get_rx_ref(np, cons);
1235 	int max = 5 /* MAX_SKB_FRAGS + (rx->status <= RX_COPY_THRESHOLD) */;
1236 	int frags = 1;
1237 	int err = 0;
1238 	u_long ret;
1239 
1240 	m0 = m = m_prev = xennet_get_rx_mbuf(np, cons);
1241 
1242 
1243 	if (rx->flags & NETRXF_extra_info) {
1244 		err = xennet_get_extras(np, extras, rp);
1245 		cons = np->rx.rsp_cons;
1246 	}
1247 
1248 
1249 	if (m0 != NULL) {
1250 			m0->m_pkthdr.len = 0;
1251 			m0->m_next = NULL;
1252 	}
1253 
1254 	for (;;) {
1255 		u_long mfn;
1256 
1257 #if 0
1258 		printf("rx->status=%hd rx->offset=%hu frags=%u\n",
1259 			rx->status, rx->offset, frags);
1260 #endif
1261 		if (unlikely(rx->status < 0 ||
1262 			rx->offset + rx->status > PAGE_SIZE)) {
1263 #if 0
1264 			if (net_ratelimit())
1265 				WPRINTK("rx->offset: %x, size: %u\n",
1266 					rx->offset, rx->status);
1267 #endif
1268 			xennet_move_rx_slot(np, m, ref);
1269 			err = -EINVAL;
1270 			goto next;
1271 		}
1272 
1273 		/*
1274 		 * This definitely indicates a bug, either in this driver or in
1275 		 * the backend driver. In future this should flag the bad
1276 		 * situation to the system controller to reboot the backed.
1277 		 */
1278 		if (ref == GRANT_INVALID_REF) {
1279 #if 0
1280 			if (net_ratelimit())
1281 				WPRINTK("Bad rx response id %d.\n", rx->id);
1282 #endif
1283 			err = -EINVAL;
1284 			goto next;
1285 		}
1286 
1287 		if (!np->copying_receiver) {
1288 			/* Memory pressure, insufficient buffer
1289 			 * headroom, ...
1290 			 */
1291 			if (!(mfn = gnttab_end_foreign_transfer_ref(ref))) {
1292 				if (net_ratelimit())
1293 					WPRINTK("Unfulfilled rx req "
1294 						"(id=%d, st=%d).\n",
1295 						rx->id, rx->status);
1296 				xennet_move_rx_slot(np, m, ref);
1297 				err = -ENOMEM;
1298 				goto next;
1299 			}
1300 
1301 			if (!xen_feature( XENFEAT_auto_translated_physmap)) {
1302 				/* Remap the page. */
1303 				void *vaddr = mtod(m, void *);
1304 				uint32_t pfn;
1305 
1306 				mcl = np->rx_mcl + pages_flipped;
1307 				mmu = np->rx_mmu + pages_flipped;
1308 
1309 				MULTI_update_va_mapping(mcl, (u_long)vaddr,
1310 				    (((vm_paddr_t)mfn) << PAGE_SHIFT) | PG_RW |
1311 				    PG_V | PG_M | PG_A, 0);
1312 				pfn = (uintptr_t)m->m_ext.ext_arg1;
1313 				mmu->ptr = ((vm_paddr_t)mfn << PAGE_SHIFT) |
1314 				    MMU_MACHPHYS_UPDATE;
1315 				mmu->val = pfn;
1316 
1317 				set_phys_to_machine(pfn, mfn);
1318 			}
1319 			pages_flipped++;
1320 		} else {
1321 			ret = gnttab_end_foreign_access_ref(ref);
1322 			KASSERT(ret, ("ret != 0"));
1323 		}
1324 
1325 		gnttab_release_grant_reference(&np->gref_rx_head, ref);
1326 
1327 next:
1328 		if (m == NULL)
1329 			break;
1330 
1331 		m->m_len = rx->status;
1332 		m->m_data += rx->offset;
1333 		m0->m_pkthdr.len += rx->status;
1334 
1335 		if (!(rx->flags & NETRXF_more_data))
1336 			break;
1337 
1338 		if (cons + frags == rp) {
1339 			if (net_ratelimit())
1340 				WPRINTK("Need more frags\n");
1341 			err = -ENOENT;
1342 				break;
1343 		}
1344 		m_prev = m;
1345 
1346 		rx = RING_GET_RESPONSE(&np->rx, cons + frags);
1347 		m = xennet_get_rx_mbuf(np, cons + frags);
1348 
1349 		m_prev->m_next = m;
1350 		m->m_next = NULL;
1351 		ref = xennet_get_rx_ref(np, cons + frags);
1352 		frags++;
1353 	}
1354 	*list = m0;
1355 
1356 	if (unlikely(frags > max)) {
1357 		if (net_ratelimit())
1358 			WPRINTK("Too many frags\n");
1359 		err = -E2BIG;
1360 	}
1361 
1362 	if (unlikely(err))
1363 		np->rx.rsp_cons = cons + frags;
1364 
1365 	*pages_flipped_p = pages_flipped;
1366 
1367 	return err;
1368 }
1369 
1370 static void
1371 xn_tick_locked(struct netfront_info *sc)
1372 {
1373 	XN_RX_LOCK_ASSERT(sc);
1374 	callout_reset(&sc->xn_stat_ch, hz, xn_tick, sc);
1375 
1376 	/* XXX placeholder for printing debug information */
1377 
1378 }
1379 
1380 
1381 static void
1382 xn_tick(void *xsc)
1383 {
1384 	struct netfront_info *sc;
1385 
1386 	sc = xsc;
1387 	XN_RX_LOCK(sc);
1388 	xn_tick_locked(sc);
1389 	XN_RX_UNLOCK(sc);
1390 
1391 }
1392 static void
1393 xn_start_locked(struct ifnet *ifp)
1394 {
1395 	int otherend_id;
1396 	unsigned short id;
1397 	struct mbuf *m_head, *m;
1398 	struct netfront_info *sc;
1399 	netif_tx_request_t *tx;
1400 	netif_extra_info_t *extra;
1401 	RING_IDX i;
1402 	grant_ref_t ref;
1403 	u_long mfn, tx_bytes;
1404 	int notify, nfrags;
1405 
1406 	sc = ifp->if_softc;
1407 	otherend_id = xenbus_get_otherend_id(sc->xbdev);
1408 	tx_bytes = 0;
1409 
1410 	if (!netfront_carrier_ok(sc))
1411 		return;
1412 
1413 	for (i = sc->tx.req_prod_pvt; TRUE; i++) {
1414 		IF_DEQUEUE(&ifp->if_snd, m_head);
1415 		if (m_head == NULL)
1416 			break;
1417 
1418 		/*
1419 		 * netfront_tx_slot_available() tries to do some math to
1420 		 * ensure that there'll be enough xenbus ring slots available
1421 		 * for the maximum number of packet fragments (and a couple more
1422 		 * for what I guess are TSO and other ring entry items.)
1423 		 */
1424 		if (!netfront_tx_slot_available(sc)) {
1425 			IF_PREPEND(&ifp->if_snd, m_head);
1426 			ifp->if_drv_flags |= IFF_DRV_OACTIVE;
1427 			break;
1428 		}
1429 
1430 		/*
1431 		 * Defragment the mbuf if necessary.
1432 		 */
1433 		for (m = m_head, nfrags = 0; m; m = m->m_next)
1434 			nfrags++;
1435 		if (nfrags > MAX_SKB_FRAGS) {
1436 			m = m_defrag(m_head, M_DONTWAIT);
1437 			if (!m) {
1438 				m_freem(m_head);
1439 				break;
1440 			}
1441 			m_head = m;
1442 		}
1443 
1444 		/* Determine how many fragments now exist */
1445 		for (m = m_head, nfrags = 0; m; m = m->m_next)
1446 			nfrags++;
1447 
1448 		/*
1449 		 * Don't attempt to queue this packet if there aren't
1450 		 * enough free entries in the chain.
1451 		 *
1452 		 * There isn't a 1:1 correspondance between the mbuf TX ring
1453 		 * and the xenbus TX ring.
1454 		 * xn_txeof() may need to be called to free up some slots.
1455 		 *
1456 		 * It is quite possible that this can be later eliminated if
1457 		 * it turns out that partial * packets can be pushed into
1458 		 * the ringbuffer, with fragments pushed in when further slots
1459 		 * free up.
1460 		 *
1461 		 * It is also quite possible that the driver will lock up
1462 		 * if the TX queue fills up with no RX traffic, and
1463 		 * the mbuf ring is exhausted. The queue may need
1464 		 * a swift kick to continue.
1465 		 */
1466 
1467 		/*
1468 		 * It is not +1 like the allocation because we need to keep
1469 		 * slot [0] free for the freelist head
1470 		 */
1471 		if (sc->xn_cdata.xn_tx_chain_cnt + nfrags >= NET_TX_RING_SIZE) {
1472 			printf("xn_start_locked: xn_tx_chain_cnt (%d) + nfrags %d >= NET_TX_RING_SIZE (%d); must be full!\n",
1473 			    (int) sc->xn_cdata.xn_tx_chain_cnt,
1474 			    (int) nfrags, (int) NET_TX_RING_SIZE);
1475 			IF_PREPEND(&ifp->if_snd, m_head);
1476 			ifp->if_drv_flags |= IFF_DRV_OACTIVE;
1477 			break;
1478 		}
1479 
1480 		/*
1481 		 * Make sure there's actually space available in the
1482 		 * Xen TX ring for this. Overcompensate for the possibility
1483 		 * of having a TCP offload fragment just in case for now
1484 		 * (the +1) rather than adding logic to accurately calculate
1485 		 * the required size.
1486 		 */
1487 		if (RING_FREE_REQUESTS(&sc->tx) < (nfrags + 1)) {
1488 			printf("xn_start_locked: free ring slots (%d) < (nfrags + 1) (%d); must be full!\n",
1489 			    (int) RING_FREE_REQUESTS(&sc->tx),
1490 			    (int) (nfrags + 1));
1491 			IF_PREPEND(&ifp->if_snd, m_head);
1492 			ifp->if_drv_flags |= IFF_DRV_OACTIVE;
1493 			break;
1494 		}
1495 
1496 		/*
1497 		 * Start packing the mbufs in this chain into
1498 		 * the fragment pointers. Stop when we run out
1499 		 * of fragments or hit the end of the mbuf chain.
1500 		 */
1501 		m = m_head;
1502 		extra = NULL;
1503 		for (m = m_head; m; m = m->m_next) {
1504 			tx = RING_GET_REQUEST(&sc->tx, i);
1505 			id = get_id_from_freelist(sc->xn_cdata.xn_tx_chain);
1506 			if (id == 0)
1507 				panic("xn_start_locked: was allocated the freelist head!\n");
1508 			sc->xn_cdata.xn_tx_chain_cnt++;
1509 			if (sc->xn_cdata.xn_tx_chain_cnt >= NET_TX_RING_SIZE+1)
1510 				panic("xn_start_locked: tx_chain_cnt must be < NET_TX_RING_SIZE+1\n");
1511 			sc->xn_cdata.xn_tx_chain[id] = m;
1512 			tx->id = id;
1513 			ref = gnttab_claim_grant_reference(&sc->gref_tx_head);
1514 			KASSERT((short)ref >= 0, ("Negative ref"));
1515 			mfn = virt_to_mfn(mtod(m, vm_offset_t));
1516 			gnttab_grant_foreign_access_ref(ref, otherend_id,
1517 			    mfn, GNTMAP_readonly);
1518 			tx->gref = sc->grant_tx_ref[id] = ref;
1519 			tx->offset = mtod(m, vm_offset_t) & (PAGE_SIZE - 1);
1520 			tx->flags = 0;
1521 			if (m == m_head) {
1522 				/*
1523 				 * The first fragment has the entire packet
1524 				 * size, subsequent fragments have just the
1525 				 * fragment size. The backend works out the
1526 				 * true size of the first fragment by
1527 				 * subtracting the sizes of the other
1528 				 * fragments.
1529 				 */
1530 				tx->size = m->m_pkthdr.len;
1531 
1532 				/*
1533 				 * The first fragment contains the
1534 				 * checksum flags and is optionally
1535 				 * followed by extra data for TSO etc.
1536 				 */
1537 				if (m->m_pkthdr.csum_flags
1538 				    & CSUM_DELAY_DATA) {
1539 					tx->flags |= (NETTXF_csum_blank
1540 					    | NETTXF_data_validated);
1541 				}
1542 #if __FreeBSD_version >= 700000
1543 				if (m->m_pkthdr.csum_flags & CSUM_TSO) {
1544 					struct netif_extra_info *gso =
1545 						(struct netif_extra_info *)
1546 						RING_GET_REQUEST(&sc->tx, ++i);
1547 
1548 					if (extra)
1549 						extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE;
1550 					else
1551 						tx->flags |= NETTXF_extra_info;
1552 
1553 					gso->u.gso.size = m->m_pkthdr.tso_segsz;
1554 					gso->u.gso.type =
1555 						XEN_NETIF_GSO_TYPE_TCPV4;
1556 					gso->u.gso.pad = 0;
1557 					gso->u.gso.features = 0;
1558 
1559 					gso->type = XEN_NETIF_EXTRA_TYPE_GSO;
1560 					gso->flags = 0;
1561 					extra = gso;
1562 				}
1563 #endif
1564 			} else {
1565 				tx->size = m->m_len;
1566 			}
1567 			if (m->m_next) {
1568 				tx->flags |= NETTXF_more_data;
1569 				i++;
1570 			}
1571 		}
1572 
1573 		BPF_MTAP(ifp, m_head);
1574 
1575 		sc->stats.tx_bytes += m_head->m_pkthdr.len;
1576 		sc->stats.tx_packets++;
1577 	}
1578 
1579 	sc->tx.req_prod_pvt = i;
1580 	RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&sc->tx, notify);
1581 	if (notify)
1582 		notify_remote_via_irq(sc->irq);
1583 
1584 	xn_txeof(sc);
1585 
1586 	if (RING_FULL(&sc->tx)) {
1587 		sc->tx_full = 1;
1588 #if 0
1589 		netif_stop_queue(dev);
1590 #endif
1591 	}
1592 
1593 	return;
1594 }
1595 
1596 static void
1597 xn_start(struct ifnet *ifp)
1598 {
1599 	struct netfront_info *sc;
1600 	sc = ifp->if_softc;
1601 	XN_TX_LOCK(sc);
1602 	xn_start_locked(ifp);
1603 	XN_TX_UNLOCK(sc);
1604 }
1605 
1606 /* equivalent of network_open() in Linux */
1607 static void
1608 xn_ifinit_locked(struct netfront_info *sc)
1609 {
1610 	struct ifnet *ifp;
1611 
1612 	XN_LOCK_ASSERT(sc);
1613 
1614 	ifp = sc->xn_ifp;
1615 
1616 	if (ifp->if_drv_flags & IFF_DRV_RUNNING)
1617 		return;
1618 
1619 	xn_stop(sc);
1620 
1621 	network_alloc_rx_buffers(sc);
1622 	sc->rx.sring->rsp_event = sc->rx.rsp_cons + 1;
1623 
1624 	ifp->if_drv_flags |= IFF_DRV_RUNNING;
1625 	ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
1626 
1627 	callout_reset(&sc->xn_stat_ch, hz, xn_tick, sc);
1628 
1629 }
1630 
1631 
1632 static void
1633 xn_ifinit(void *xsc)
1634 {
1635 	struct netfront_info *sc = xsc;
1636 
1637 	XN_LOCK(sc);
1638 	xn_ifinit_locked(sc);
1639 	XN_UNLOCK(sc);
1640 
1641 }
1642 
1643 
1644 static int
1645 xn_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data)
1646 {
1647 	struct netfront_info *sc = ifp->if_softc;
1648 	struct ifreq *ifr = (struct ifreq *) data;
1649 	struct ifaddr *ifa = (struct ifaddr *)data;
1650 
1651 	int mask, error = 0;
1652 	switch(cmd) {
1653 	case SIOCSIFADDR:
1654 	case SIOCGIFADDR:
1655 		XN_LOCK(sc);
1656 		if (ifa->ifa_addr->sa_family == AF_INET) {
1657 			ifp->if_flags |= IFF_UP;
1658 			if (!(ifp->if_drv_flags & IFF_DRV_RUNNING))
1659 				xn_ifinit_locked(sc);
1660 			arp_ifinit(ifp, ifa);
1661 			XN_UNLOCK(sc);
1662 		} else {
1663 			XN_UNLOCK(sc);
1664 			error = ether_ioctl(ifp, cmd, data);
1665 		}
1666 		break;
1667 	case SIOCSIFMTU:
1668 		/* XXX can we alter the MTU on a VN ?*/
1669 #ifdef notyet
1670 		if (ifr->ifr_mtu > XN_JUMBO_MTU)
1671 			error = EINVAL;
1672 		else
1673 #endif
1674 		{
1675 			ifp->if_mtu = ifr->ifr_mtu;
1676 			ifp->if_drv_flags &= ~IFF_DRV_RUNNING;
1677 			xn_ifinit(sc);
1678 		}
1679 		break;
1680 	case SIOCSIFFLAGS:
1681 		XN_LOCK(sc);
1682 		if (ifp->if_flags & IFF_UP) {
1683 			/*
1684 			 * If only the state of the PROMISC flag changed,
1685 			 * then just use the 'set promisc mode' command
1686 			 * instead of reinitializing the entire NIC. Doing
1687 			 * a full re-init means reloading the firmware and
1688 			 * waiting for it to start up, which may take a
1689 			 * second or two.
1690 			 */
1691 #ifdef notyet
1692 			/* No promiscuous mode with Xen */
1693 			if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
1694 			    ifp->if_flags & IFF_PROMISC &&
1695 			    !(sc->xn_if_flags & IFF_PROMISC)) {
1696 				XN_SETBIT(sc, XN_RX_MODE,
1697 					  XN_RXMODE_RX_PROMISC);
1698 			} else if (ifp->if_drv_flags & IFF_DRV_RUNNING &&
1699 				   !(ifp->if_flags & IFF_PROMISC) &&
1700 				   sc->xn_if_flags & IFF_PROMISC) {
1701 				XN_CLRBIT(sc, XN_RX_MODE,
1702 					  XN_RXMODE_RX_PROMISC);
1703 			} else
1704 #endif
1705 				xn_ifinit_locked(sc);
1706 		} else {
1707 			if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1708 				xn_stop(sc);
1709 			}
1710 		}
1711 		sc->xn_if_flags = ifp->if_flags;
1712 		XN_UNLOCK(sc);
1713 		error = 0;
1714 		break;
1715 	case SIOCSIFCAP:
1716 		mask = ifr->ifr_reqcap ^ ifp->if_capenable;
1717 		if (mask & IFCAP_TXCSUM) {
1718 			if (IFCAP_TXCSUM & ifp->if_capenable) {
1719 				ifp->if_capenable &= ~(IFCAP_TXCSUM|IFCAP_TSO4);
1720 				ifp->if_hwassist &= ~(CSUM_TCP | CSUM_UDP
1721 				    | CSUM_IP | CSUM_TSO);
1722 			} else {
1723 				ifp->if_capenable |= IFCAP_TXCSUM;
1724 				ifp->if_hwassist |= (CSUM_TCP | CSUM_UDP
1725 				    | CSUM_IP);
1726 			}
1727 		}
1728 		if (mask & IFCAP_RXCSUM) {
1729 			ifp->if_capenable ^= IFCAP_RXCSUM;
1730 		}
1731 #if __FreeBSD_version >= 700000
1732 		if (mask & IFCAP_TSO4) {
1733 			if (IFCAP_TSO4 & ifp->if_capenable) {
1734 				ifp->if_capenable &= ~IFCAP_TSO4;
1735 				ifp->if_hwassist &= ~CSUM_TSO;
1736 			} else if (IFCAP_TXCSUM & ifp->if_capenable) {
1737 				ifp->if_capenable |= IFCAP_TSO4;
1738 				ifp->if_hwassist |= CSUM_TSO;
1739 			} else {
1740 				IPRINTK("Xen requires tx checksum offload"
1741 				    " be enabled to use TSO\n");
1742 				error = EINVAL;
1743 			}
1744 		}
1745 		if (mask & IFCAP_LRO) {
1746 			ifp->if_capenable ^= IFCAP_LRO;
1747 
1748 		}
1749 #endif
1750 		error = 0;
1751 		break;
1752 	case SIOCADDMULTI:
1753 	case SIOCDELMULTI:
1754 #ifdef notyet
1755 		if (ifp->if_drv_flags & IFF_DRV_RUNNING) {
1756 			XN_LOCK(sc);
1757 			xn_setmulti(sc);
1758 			XN_UNLOCK(sc);
1759 			error = 0;
1760 		}
1761 #endif
1762 		/* FALLTHROUGH */
1763 	case SIOCSIFMEDIA:
1764 	case SIOCGIFMEDIA:
1765 		error = EINVAL;
1766 		break;
1767 	default:
1768 		error = ether_ioctl(ifp, cmd, data);
1769 	}
1770 
1771 	return (error);
1772 }
1773 
1774 static void
1775 xn_stop(struct netfront_info *sc)
1776 {
1777 	struct ifnet *ifp;
1778 
1779 	XN_LOCK_ASSERT(sc);
1780 
1781 	ifp = sc->xn_ifp;
1782 
1783 	callout_stop(&sc->xn_stat_ch);
1784 
1785 	xn_free_rx_ring(sc);
1786 	xn_free_tx_ring(sc);
1787 
1788 	ifp->if_drv_flags &= ~(IFF_DRV_RUNNING | IFF_DRV_OACTIVE);
1789 }
1790 
1791 /* START of Xenolinux helper functions adapted to FreeBSD */
1792 int
1793 network_connect(struct netfront_info *np)
1794 {
1795 	int i, requeue_idx, error;
1796 	grant_ref_t ref;
1797 	netif_rx_request_t *req;
1798 	u_int feature_rx_copy, feature_rx_flip;
1799 
1800 	error = xenbus_scanf(XBT_NIL, xenbus_get_otherend_path(np->xbdev),
1801 	    "feature-rx-copy", NULL, "%u", &feature_rx_copy);
1802 	if (error)
1803 		feature_rx_copy = 0;
1804 	error = xenbus_scanf(XBT_NIL, xenbus_get_otherend_path(np->xbdev),
1805 	    "feature-rx-flip", NULL, "%u", &feature_rx_flip);
1806 	if (error)
1807 		feature_rx_flip = 1;
1808 
1809 	/*
1810 	 * Copy packets on receive path if:
1811 	 *  (a) This was requested by user, and the backend supports it; or
1812 	 *  (b) Flipping was requested, but this is unsupported by the backend.
1813 	 */
1814 	np->copying_receiver = ((MODPARM_rx_copy && feature_rx_copy) ||
1815 				(MODPARM_rx_flip && !feature_rx_flip));
1816 
1817 	XN_LOCK(np);
1818 	/* Recovery procedure: */
1819 	error = talk_to_backend(np->xbdev, np);
1820 	if (error)
1821 		return (error);
1822 
1823 	/* Step 1: Reinitialise variables. */
1824 	netif_release_tx_bufs(np);
1825 
1826 	/* Step 2: Rebuild the RX buffer freelist and the RX ring itself. */
1827 	for (requeue_idx = 0, i = 0; i < NET_RX_RING_SIZE; i++) {
1828 		struct mbuf *m;
1829 		u_long pfn;
1830 
1831 		if (np->rx_mbufs[i] == NULL)
1832 			continue;
1833 
1834 		m = np->rx_mbufs[requeue_idx] = xennet_get_rx_mbuf(np, i);
1835 		ref = np->grant_rx_ref[requeue_idx] = xennet_get_rx_ref(np, i);
1836 		req = RING_GET_REQUEST(&np->rx, requeue_idx);
1837 		pfn = vtophys(mtod(m, vm_offset_t)) >> PAGE_SHIFT;
1838 
1839 		if (!np->copying_receiver) {
1840 			gnttab_grant_foreign_transfer_ref(ref,
1841 			    xenbus_get_otherend_id(np->xbdev),
1842 			    pfn);
1843 		} else {
1844 			gnttab_grant_foreign_access_ref(ref,
1845 			    xenbus_get_otherend_id(np->xbdev),
1846 			    PFNTOMFN(pfn), 0);
1847 		}
1848 		req->gref = ref;
1849 		req->id   = requeue_idx;
1850 
1851 		requeue_idx++;
1852 	}
1853 
1854 	np->rx.req_prod_pvt = requeue_idx;
1855 
1856 	/* Step 3: All public and private state should now be sane.  Get
1857 	 * ready to start sending and receiving packets and give the driver
1858 	 * domain a kick because we've probably just requeued some
1859 	 * packets.
1860 	 */
1861 	netfront_carrier_on(np);
1862 	notify_remote_via_irq(np->irq);
1863 	XN_TX_LOCK(np);
1864 	xn_txeof(np);
1865 	XN_TX_UNLOCK(np);
1866 	network_alloc_rx_buffers(np);
1867 	XN_UNLOCK(np);
1868 
1869 	return (0);
1870 }
1871 
1872 static void
1873 show_device(struct netfront_info *sc)
1874 {
1875 #ifdef DEBUG
1876 	if (sc) {
1877 		IPRINTK("<vif handle=%u %s(%s) evtchn=%u irq=%u tx=%p rx=%p>\n",
1878 			sc->xn_ifno,
1879 			be_state_name[sc->xn_backend_state],
1880 			sc->xn_user_state ? "open" : "closed",
1881 			sc->xn_evtchn,
1882 			sc->xn_irq,
1883 			sc->xn_tx_if,
1884 			sc->xn_rx_if);
1885 	} else {
1886 		IPRINTK("<vif NULL>\n");
1887 	}
1888 #endif
1889 }
1890 
1891 /** Create a network device.
1892  * @param handle device handle
1893  */
1894 int
1895 create_netdev(device_t dev)
1896 {
1897 	int i;
1898 	struct netfront_info *np;
1899 	int err;
1900 	struct ifnet *ifp;
1901 
1902 	np = device_get_softc(dev);
1903 
1904 	np->xbdev         = dev;
1905 
1906 	XN_LOCK_INIT(np, xennetif);
1907 	np->rx_target     = RX_MIN_TARGET;
1908 	np->rx_min_target = RX_MIN_TARGET;
1909 	np->rx_max_target = RX_MAX_TARGET;
1910 
1911 	/* Initialise {tx,rx}_skbs to be a free chain containing every entry. */
1912 	for (i = 0; i <= NET_TX_RING_SIZE; i++) {
1913 		np->tx_mbufs[i] = (void *) ((u_long) i+1);
1914 		np->grant_tx_ref[i] = GRANT_INVALID_REF;
1915 	}
1916 	for (i = 0; i <= NET_RX_RING_SIZE; i++) {
1917 		np->rx_mbufs[i] = NULL;
1918 		np->grant_rx_ref[i] = GRANT_INVALID_REF;
1919 	}
1920 	/* A grant for every tx ring slot */
1921 	if (gnttab_alloc_grant_references(TX_MAX_TARGET,
1922 					  &np->gref_tx_head) < 0) {
1923 		printf("#### netfront can't alloc tx grant refs\n");
1924 		err = ENOMEM;
1925 		goto exit;
1926 	}
1927 	/* A grant for every rx ring slot */
1928 	if (gnttab_alloc_grant_references(RX_MAX_TARGET,
1929 					  &np->gref_rx_head) < 0) {
1930 		printf("#### netfront can't alloc rx grant refs\n");
1931 		gnttab_free_grant_references(np->gref_tx_head);
1932 		err = ENOMEM;
1933 		goto exit;
1934 	}
1935 
1936 	err = xen_net_read_mac(dev, np->mac);
1937 	if (err) {
1938 		xenbus_dev_fatal(dev, err, "parsing %s/mac",
1939 		    xenbus_get_node(dev));
1940 		goto out;
1941 	}
1942 
1943 	/* Set up ifnet structure */
1944 	ifp = np->xn_ifp = if_alloc(IFT_ETHER);
1945     	ifp->if_softc = np;
1946     	if_initname(ifp, "xn",  device_get_unit(dev));
1947     	ifp->if_flags = IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST;
1948     	ifp->if_ioctl = xn_ioctl;
1949     	ifp->if_output = ether_output;
1950     	ifp->if_start = xn_start;
1951 #ifdef notyet
1952     	ifp->if_watchdog = xn_watchdog;
1953 #endif
1954     	ifp->if_init = xn_ifinit;
1955     	ifp->if_mtu = ETHERMTU;
1956     	ifp->if_snd.ifq_maxlen = NET_TX_RING_SIZE - 1;
1957 
1958     	ifp->if_hwassist = XN_CSUM_FEATURES;
1959     	ifp->if_capabilities = IFCAP_HWCSUM;
1960 #if __FreeBSD_version >= 700000
1961 	ifp->if_capabilities |= IFCAP_TSO4;
1962 	if (xn_enable_lro) {
1963 		int err = tcp_lro_init(&np->xn_lro);
1964 		if (err) {
1965 			device_printf(dev, "LRO initialization failed\n");
1966 			goto exit;
1967 		}
1968 		np->xn_lro.ifp = ifp;
1969 		ifp->if_capabilities |= IFCAP_LRO;
1970 	}
1971 #endif
1972     	ifp->if_capenable = ifp->if_capabilities;
1973 
1974     	ether_ifattach(ifp, np->mac);
1975     	callout_init(&np->xn_stat_ch, CALLOUT_MPSAFE);
1976 	netfront_carrier_off(np);
1977 
1978 	return (0);
1979 
1980 exit:
1981 	gnttab_free_grant_references(np->gref_tx_head);
1982 out:
1983 	panic("do something smart");
1984 
1985 }
1986 
1987 /**
1988  * Handle the change of state of the backend to Closing.  We must delete our
1989  * device-layer structures now, to ensure that writes are flushed through to
1990  * the backend.  Once is this done, we can switch to Closed in
1991  * acknowledgement.
1992  */
1993 #if 0
1994 static void netfront_closing(device_t dev)
1995 {
1996 #if 0
1997 	struct netfront_info *info = dev->dev_driver_data;
1998 
1999 	DPRINTK("netfront_closing: %s removed\n", dev->nodename);
2000 
2001 	close_netdev(info);
2002 #endif
2003 	xenbus_switch_state(dev, XenbusStateClosed);
2004 }
2005 #endif
2006 
2007 static int netfront_detach(device_t dev)
2008 {
2009 	struct netfront_info *info = device_get_softc(dev);
2010 
2011 	DPRINTK("%s\n", xenbus_get_node(dev));
2012 
2013 	netif_free(info);
2014 
2015 	return 0;
2016 }
2017 
2018 
2019 static void netif_free(struct netfront_info *info)
2020 {
2021 	netif_disconnect_backend(info);
2022 #if 0
2023 	close_netdev(info);
2024 #endif
2025 }
2026 
2027 static void netif_disconnect_backend(struct netfront_info *info)
2028 {
2029 	XN_RX_LOCK(info);
2030 	XN_TX_LOCK(info);
2031 	netfront_carrier_off(info);
2032 	XN_TX_UNLOCK(info);
2033 	XN_RX_UNLOCK(info);
2034 
2035 	end_access(info->tx_ring_ref, info->tx.sring);
2036 	end_access(info->rx_ring_ref, info->rx.sring);
2037 	info->tx_ring_ref = GRANT_INVALID_REF;
2038 	info->rx_ring_ref = GRANT_INVALID_REF;
2039 	info->tx.sring = NULL;
2040 	info->rx.sring = NULL;
2041 
2042 	if (info->irq)
2043 		unbind_from_irqhandler(info->irq);
2044 
2045 	info->irq = 0;
2046 }
2047 
2048 
2049 static void end_access(int ref, void *page)
2050 {
2051 	if (ref != GRANT_INVALID_REF)
2052 		gnttab_end_foreign_access(ref, page);
2053 }
2054 
2055 /* ** Driver registration ** */
2056 static device_method_t netfront_methods[] = {
2057 	/* Device interface */
2058 	DEVMETHOD(device_probe,         netfront_probe),
2059 	DEVMETHOD(device_attach,        netfront_attach),
2060 	DEVMETHOD(device_detach,        netfront_detach),
2061 	DEVMETHOD(device_shutdown,      bus_generic_shutdown),
2062 	DEVMETHOD(device_suspend,       bus_generic_suspend),
2063 	DEVMETHOD(device_resume,        netfront_resume),
2064 
2065 	/* Xenbus interface */
2066 	DEVMETHOD(xenbus_backend_changed, netfront_backend_changed),
2067 
2068 	{ 0, 0 }
2069 };
2070 
2071 static driver_t netfront_driver = {
2072 	"xn",
2073 	netfront_methods,
2074 	sizeof(struct netfront_info),
2075 };
2076 devclass_t netfront_devclass;
2077 
2078 DRIVER_MODULE(xe, xenbus, netfront_driver, netfront_devclass, 0, 0);
2079