1 /*
2  * Network-device interface management.
3  *
4  * Copyright (c) 2004-2005, Keir Fraser
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License version 2
8  * as published by the Free Software Foundation; or, when distributed
9  * separately from the Linux kernel or incorporated into other
10  * software packages, subject to the following license:
11  *
12  * Permission is hereby granted, free of charge, to any person obtaining a copy
13  * of this source file (the "Software"), to deal in the Software without
14  * restriction, including without limitation the rights to use, copy, modify,
15  * merge, publish, distribute, sublicense, and/or sell copies of the Software,
16  * and to permit persons to whom the Software is furnished to do so, subject to
17  * the following conditions:
18  *
19  * The above copyright notice and this permission notice shall be included in
20  * all copies or substantial portions of the Software.
21  *
22  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
23  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
24  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
25  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
26  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
27  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
28  * IN THE SOFTWARE.
29  */
30 
31 #include "common.h"
32 
33 #include <linux/kthread.h>
34 #include <linux/ethtool.h>
35 #include <linux/rtnetlink.h>
36 #include <linux/if_vlan.h>
37 #include <linux/vmalloc.h>
38 
39 #include <xen/events.h>
40 #include <asm/xen/hypercall.h>
41 #include <xen/balloon.h>
42 
43 #define XENVIF_QUEUE_LENGTH 32
44 #define XENVIF_NAPI_WEIGHT  64
45 
46 /* Number of bytes allowed on the internal guest Rx queue. */
47 #define XENVIF_RX_QUEUE_BYTES (XEN_NETIF_RX_RING_SIZE/2 * PAGE_SIZE)
48 
49 /* This function is used to set SKBTX_DEV_ZEROCOPY as well as
50  * increasing the inflight counter. We need to increase the inflight
51  * counter because core driver calls into xenvif_zerocopy_callback
52  * which calls xenvif_skb_zerocopy_complete.
53  */
54 void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
55 				 struct sk_buff *skb)
56 {
57 	skb_shinfo(skb)->tx_flags |= SKBTX_DEV_ZEROCOPY;
58 	atomic_inc(&queue->inflight_packets);
59 }
60 
61 void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue)
62 {
63 	atomic_dec(&queue->inflight_packets);
64 
65 	/* Wake the dealloc thread _after_ decrementing inflight_packets so
66 	 * that if kthread_stop() has already been called, the dealloc thread
67 	 * does not wait forever with nothing to wake it.
68 	 */
69 	wake_up(&queue->dealloc_wq);
70 }
71 
72 int xenvif_schedulable(struct xenvif *vif)
73 {
74 	return netif_running(vif->dev) &&
75 		test_bit(VIF_STATUS_CONNECTED, &vif->status) &&
76 		!vif->disabled;
77 }
78 
79 static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
80 {
81 	struct xenvif_queue *queue = dev_id;
82 
83 	if (RING_HAS_UNCONSUMED_REQUESTS(&queue->tx))
84 		napi_schedule(&queue->napi);
85 
86 	return IRQ_HANDLED;
87 }
88 
89 static int xenvif_poll(struct napi_struct *napi, int budget)
90 {
91 	struct xenvif_queue *queue =
92 		container_of(napi, struct xenvif_queue, napi);
93 	int work_done;
94 
95 	/* This vif is rogue, we pretend we've there is nothing to do
96 	 * for this vif to deschedule it from NAPI. But this interface
97 	 * will be turned off in thread context later.
98 	 */
99 	if (unlikely(queue->vif->disabled)) {
100 		napi_complete(napi);
101 		return 0;
102 	}
103 
104 	work_done = xenvif_tx_action(queue, budget);
105 
106 	if (work_done < budget) {
107 		napi_complete(napi);
108 		xenvif_napi_schedule_or_enable_events(queue);
109 	}
110 
111 	return work_done;
112 }
113 
114 static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
115 {
116 	struct xenvif_queue *queue = dev_id;
117 
118 	xenvif_kick_thread(queue);
119 
120 	return IRQ_HANDLED;
121 }
122 
123 irqreturn_t xenvif_interrupt(int irq, void *dev_id)
124 {
125 	xenvif_tx_interrupt(irq, dev_id);
126 	xenvif_rx_interrupt(irq, dev_id);
127 
128 	return IRQ_HANDLED;
129 }
130 
131 int xenvif_queue_stopped(struct xenvif_queue *queue)
132 {
133 	struct net_device *dev = queue->vif->dev;
134 	unsigned int id = queue->id;
135 	return netif_tx_queue_stopped(netdev_get_tx_queue(dev, id));
136 }
137 
138 void xenvif_wake_queue(struct xenvif_queue *queue)
139 {
140 	struct net_device *dev = queue->vif->dev;
141 	unsigned int id = queue->id;
142 	netif_tx_wake_queue(netdev_get_tx_queue(dev, id));
143 }
144 
145 static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
146 {
147 	struct xenvif *vif = netdev_priv(dev);
148 	struct xenvif_queue *queue = NULL;
149 	unsigned int num_queues = vif->num_queues;
150 	u16 index;
151 	struct xenvif_rx_cb *cb;
152 
153 	BUG_ON(skb->dev != dev);
154 
155 	/* Drop the packet if queues are not set up */
156 	if (num_queues < 1)
157 		goto drop;
158 
159 	/* Obtain the queue to be used to transmit this packet */
160 	index = skb_get_queue_mapping(skb);
161 	if (index >= num_queues) {
162 		pr_warn_ratelimited("Invalid queue %hu for packet on interface %s\n.",
163 				    index, vif->dev->name);
164 		index %= num_queues;
165 	}
166 	queue = &vif->queues[index];
167 
168 	/* Drop the packet if queue is not ready */
169 	if (queue->task == NULL ||
170 	    queue->dealloc_task == NULL ||
171 	    !xenvif_schedulable(vif))
172 		goto drop;
173 
174 	if (vif->multicast_control && skb->pkt_type == PACKET_MULTICAST) {
175 		struct ethhdr *eth = (struct ethhdr *)skb->data;
176 
177 		if (!xenvif_mcast_match(vif, eth->h_dest))
178 			goto drop;
179 	}
180 
181 	cb = XENVIF_RX_CB(skb);
182 	cb->expires = jiffies + vif->drain_timeout;
183 
184 	xenvif_rx_queue_tail(queue, skb);
185 	xenvif_kick_thread(queue);
186 
187 	return NETDEV_TX_OK;
188 
189  drop:
190 	vif->dev->stats.tx_dropped++;
191 	dev_kfree_skb(skb);
192 	return NETDEV_TX_OK;
193 }
194 
195 static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
196 {
197 	struct xenvif *vif = netdev_priv(dev);
198 	struct xenvif_queue *queue = NULL;
199 	unsigned int num_queues = vif->num_queues;
200 	unsigned long rx_bytes = 0;
201 	unsigned long rx_packets = 0;
202 	unsigned long tx_bytes = 0;
203 	unsigned long tx_packets = 0;
204 	unsigned int index;
205 
206 	if (vif->queues == NULL)
207 		goto out;
208 
209 	/* Aggregate tx and rx stats from each queue */
210 	for (index = 0; index < num_queues; ++index) {
211 		queue = &vif->queues[index];
212 		rx_bytes += queue->stats.rx_bytes;
213 		rx_packets += queue->stats.rx_packets;
214 		tx_bytes += queue->stats.tx_bytes;
215 		tx_packets += queue->stats.tx_packets;
216 	}
217 
218 out:
219 	vif->dev->stats.rx_bytes = rx_bytes;
220 	vif->dev->stats.rx_packets = rx_packets;
221 	vif->dev->stats.tx_bytes = tx_bytes;
222 	vif->dev->stats.tx_packets = tx_packets;
223 
224 	return &vif->dev->stats;
225 }
226 
227 static void xenvif_up(struct xenvif *vif)
228 {
229 	struct xenvif_queue *queue = NULL;
230 	unsigned int num_queues = vif->num_queues;
231 	unsigned int queue_index;
232 
233 	for (queue_index = 0; queue_index < num_queues; ++queue_index) {
234 		queue = &vif->queues[queue_index];
235 		napi_enable(&queue->napi);
236 		enable_irq(queue->tx_irq);
237 		if (queue->tx_irq != queue->rx_irq)
238 			enable_irq(queue->rx_irq);
239 		xenvif_napi_schedule_or_enable_events(queue);
240 	}
241 }
242 
243 static void xenvif_down(struct xenvif *vif)
244 {
245 	struct xenvif_queue *queue = NULL;
246 	unsigned int num_queues = vif->num_queues;
247 	unsigned int queue_index;
248 
249 	for (queue_index = 0; queue_index < num_queues; ++queue_index) {
250 		queue = &vif->queues[queue_index];
251 		disable_irq(queue->tx_irq);
252 		if (queue->tx_irq != queue->rx_irq)
253 			disable_irq(queue->rx_irq);
254 		napi_disable(&queue->napi);
255 		del_timer_sync(&queue->credit_timeout);
256 	}
257 }
258 
259 static int xenvif_open(struct net_device *dev)
260 {
261 	struct xenvif *vif = netdev_priv(dev);
262 	if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
263 		xenvif_up(vif);
264 	netif_tx_start_all_queues(dev);
265 	return 0;
266 }
267 
268 static int xenvif_close(struct net_device *dev)
269 {
270 	struct xenvif *vif = netdev_priv(dev);
271 	if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
272 		xenvif_down(vif);
273 	netif_tx_stop_all_queues(dev);
274 	return 0;
275 }
276 
277 static int xenvif_change_mtu(struct net_device *dev, int mtu)
278 {
279 	struct xenvif *vif = netdev_priv(dev);
280 	int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN;
281 
282 	if (mtu > max)
283 		return -EINVAL;
284 	dev->mtu = mtu;
285 	return 0;
286 }
287 
288 static netdev_features_t xenvif_fix_features(struct net_device *dev,
289 	netdev_features_t features)
290 {
291 	struct xenvif *vif = netdev_priv(dev);
292 
293 	if (!vif->can_sg)
294 		features &= ~NETIF_F_SG;
295 	if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV4))
296 		features &= ~NETIF_F_TSO;
297 	if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV6))
298 		features &= ~NETIF_F_TSO6;
299 	if (!vif->ip_csum)
300 		features &= ~NETIF_F_IP_CSUM;
301 	if (!vif->ipv6_csum)
302 		features &= ~NETIF_F_IPV6_CSUM;
303 
304 	return features;
305 }
306 
307 static const struct xenvif_stat {
308 	char name[ETH_GSTRING_LEN];
309 	u16 offset;
310 } xenvif_stats[] = {
311 	{
312 		"rx_gso_checksum_fixup",
313 		offsetof(struct xenvif_stats, rx_gso_checksum_fixup)
314 	},
315 	/* If (sent != success + fail), there are probably packets never
316 	 * freed up properly!
317 	 */
318 	{
319 		"tx_zerocopy_sent",
320 		offsetof(struct xenvif_stats, tx_zerocopy_sent),
321 	},
322 	{
323 		"tx_zerocopy_success",
324 		offsetof(struct xenvif_stats, tx_zerocopy_success),
325 	},
326 	{
327 		"tx_zerocopy_fail",
328 		offsetof(struct xenvif_stats, tx_zerocopy_fail)
329 	},
330 	/* Number of packets exceeding MAX_SKB_FRAG slots. You should use
331 	 * a guest with the same MAX_SKB_FRAG
332 	 */
333 	{
334 		"tx_frag_overflow",
335 		offsetof(struct xenvif_stats, tx_frag_overflow)
336 	},
337 };
338 
339 static int xenvif_get_sset_count(struct net_device *dev, int string_set)
340 {
341 	switch (string_set) {
342 	case ETH_SS_STATS:
343 		return ARRAY_SIZE(xenvif_stats);
344 	default:
345 		return -EINVAL;
346 	}
347 }
348 
349 static void xenvif_get_ethtool_stats(struct net_device *dev,
350 				     struct ethtool_stats *stats, u64 * data)
351 {
352 	struct xenvif *vif = netdev_priv(dev);
353 	unsigned int num_queues = vif->num_queues;
354 	int i;
355 	unsigned int queue_index;
356 
357 	for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) {
358 		unsigned long accum = 0;
359 		for (queue_index = 0; queue_index < num_queues; ++queue_index) {
360 			void *vif_stats = &vif->queues[queue_index].stats;
361 			accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset);
362 		}
363 		data[i] = accum;
364 	}
365 }
366 
367 static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
368 {
369 	int i;
370 
371 	switch (stringset) {
372 	case ETH_SS_STATS:
373 		for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
374 			memcpy(data + i * ETH_GSTRING_LEN,
375 			       xenvif_stats[i].name, ETH_GSTRING_LEN);
376 		break;
377 	}
378 }
379 
380 static const struct ethtool_ops xenvif_ethtool_ops = {
381 	.get_link	= ethtool_op_get_link,
382 
383 	.get_sset_count = xenvif_get_sset_count,
384 	.get_ethtool_stats = xenvif_get_ethtool_stats,
385 	.get_strings = xenvif_get_strings,
386 };
387 
388 static const struct net_device_ops xenvif_netdev_ops = {
389 	.ndo_start_xmit	= xenvif_start_xmit,
390 	.ndo_get_stats	= xenvif_get_stats,
391 	.ndo_open	= xenvif_open,
392 	.ndo_stop	= xenvif_close,
393 	.ndo_change_mtu	= xenvif_change_mtu,
394 	.ndo_fix_features = xenvif_fix_features,
395 	.ndo_set_mac_address = eth_mac_addr,
396 	.ndo_validate_addr   = eth_validate_addr,
397 };
398 
399 struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
400 			    unsigned int handle)
401 {
402 	int err;
403 	struct net_device *dev;
404 	struct xenvif *vif;
405 	char name[IFNAMSIZ] = {};
406 
407 	snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
408 	/* Allocate a netdev with the max. supported number of queues.
409 	 * When the guest selects the desired number, it will be updated
410 	 * via netif_set_real_num_*_queues().
411 	 */
412 	dev = alloc_netdev_mq(sizeof(struct xenvif), name, NET_NAME_UNKNOWN,
413 			      ether_setup, xenvif_max_queues);
414 	if (dev == NULL) {
415 		pr_warn("Could not allocate netdev for %s\n", name);
416 		return ERR_PTR(-ENOMEM);
417 	}
418 
419 	SET_NETDEV_DEV(dev, parent);
420 
421 	vif = netdev_priv(dev);
422 
423 	vif->domid  = domid;
424 	vif->handle = handle;
425 	vif->can_sg = 1;
426 	vif->ip_csum = 1;
427 	vif->dev = dev;
428 	vif->disabled = false;
429 	vif->drain_timeout = msecs_to_jiffies(rx_drain_timeout_msecs);
430 	vif->stall_timeout = msecs_to_jiffies(rx_stall_timeout_msecs);
431 
432 	/* Start out with no queues. */
433 	vif->queues = NULL;
434 	vif->num_queues = 0;
435 
436 	spin_lock_init(&vif->lock);
437 	INIT_LIST_HEAD(&vif->fe_mcast_addr);
438 
439 	dev->netdev_ops	= &xenvif_netdev_ops;
440 	dev->hw_features = NETIF_F_SG |
441 		NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
442 		NETIF_F_TSO | NETIF_F_TSO6;
443 	dev->features = dev->hw_features | NETIF_F_RXCSUM;
444 	dev->ethtool_ops = &xenvif_ethtool_ops;
445 
446 	dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
447 
448 	/*
449 	 * Initialise a dummy MAC address. We choose the numerically
450 	 * largest non-broadcast address to prevent the address getting
451 	 * stolen by an Ethernet bridge for STP purposes.
452 	 * (FE:FF:FF:FF:FF:FF)
453 	 */
454 	eth_broadcast_addr(dev->dev_addr);
455 	dev->dev_addr[0] &= ~0x01;
456 
457 	netif_carrier_off(dev);
458 
459 	err = register_netdev(dev);
460 	if (err) {
461 		netdev_warn(dev, "Could not register device: err=%d\n", err);
462 		free_netdev(dev);
463 		return ERR_PTR(err);
464 	}
465 
466 	netdev_dbg(dev, "Successfully created xenvif\n");
467 
468 	__module_get(THIS_MODULE);
469 
470 	return vif;
471 }
472 
473 int xenvif_init_queue(struct xenvif_queue *queue)
474 {
475 	int err, i;
476 
477 	queue->credit_bytes = queue->remaining_credit = ~0UL;
478 	queue->credit_usec  = 0UL;
479 	init_timer(&queue->credit_timeout);
480 	queue->credit_timeout.function = xenvif_tx_credit_callback;
481 	queue->credit_window_start = get_jiffies_64();
482 
483 	queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES;
484 
485 	skb_queue_head_init(&queue->rx_queue);
486 	skb_queue_head_init(&queue->tx_queue);
487 
488 	queue->pending_cons = 0;
489 	queue->pending_prod = MAX_PENDING_REQS;
490 	for (i = 0; i < MAX_PENDING_REQS; ++i)
491 		queue->pending_ring[i] = i;
492 
493 	spin_lock_init(&queue->callback_lock);
494 	spin_lock_init(&queue->response_lock);
495 
496 	/* If ballooning is disabled, this will consume real memory, so you
497 	 * better enable it. The long term solution would be to use just a
498 	 * bunch of valid page descriptors, without dependency on ballooning
499 	 */
500 	err = gnttab_alloc_pages(MAX_PENDING_REQS,
501 				 queue->mmap_pages);
502 	if (err) {
503 		netdev_err(queue->vif->dev, "Could not reserve mmap_pages\n");
504 		return -ENOMEM;
505 	}
506 
507 	for (i = 0; i < MAX_PENDING_REQS; i++) {
508 		queue->pending_tx_info[i].callback_struct = (struct ubuf_info)
509 			{ .callback = xenvif_zerocopy_callback,
510 			  .ctx = NULL,
511 			  .desc = i };
512 		queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE;
513 	}
514 
515 	return 0;
516 }
517 
518 void xenvif_carrier_on(struct xenvif *vif)
519 {
520 	rtnl_lock();
521 	if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
522 		dev_set_mtu(vif->dev, ETH_DATA_LEN);
523 	netdev_update_features(vif->dev);
524 	set_bit(VIF_STATUS_CONNECTED, &vif->status);
525 	if (netif_running(vif->dev))
526 		xenvif_up(vif);
527 	rtnl_unlock();
528 }
529 
530 int xenvif_connect(struct xenvif_queue *queue, unsigned long tx_ring_ref,
531 		   unsigned long rx_ring_ref, unsigned int tx_evtchn,
532 		   unsigned int rx_evtchn)
533 {
534 	struct task_struct *task;
535 	int err = -ENOMEM;
536 
537 	BUG_ON(queue->tx_irq);
538 	BUG_ON(queue->task);
539 	BUG_ON(queue->dealloc_task);
540 
541 	err = xenvif_map_frontend_rings(queue, tx_ring_ref, rx_ring_ref);
542 	if (err < 0)
543 		goto err;
544 
545 	init_waitqueue_head(&queue->wq);
546 	init_waitqueue_head(&queue->dealloc_wq);
547 	atomic_set(&queue->inflight_packets, 0);
548 
549 	netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll,
550 			XENVIF_NAPI_WEIGHT);
551 
552 	if (tx_evtchn == rx_evtchn) {
553 		/* feature-split-event-channels == 0 */
554 		err = bind_interdomain_evtchn_to_irqhandler(
555 			queue->vif->domid, tx_evtchn, xenvif_interrupt, 0,
556 			queue->name, queue);
557 		if (err < 0)
558 			goto err_unmap;
559 		queue->tx_irq = queue->rx_irq = err;
560 		disable_irq(queue->tx_irq);
561 	} else {
562 		/* feature-split-event-channels == 1 */
563 		snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
564 			 "%s-tx", queue->name);
565 		err = bind_interdomain_evtchn_to_irqhandler(
566 			queue->vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
567 			queue->tx_irq_name, queue);
568 		if (err < 0)
569 			goto err_unmap;
570 		queue->tx_irq = err;
571 		disable_irq(queue->tx_irq);
572 
573 		snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
574 			 "%s-rx", queue->name);
575 		err = bind_interdomain_evtchn_to_irqhandler(
576 			queue->vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
577 			queue->rx_irq_name, queue);
578 		if (err < 0)
579 			goto err_tx_unbind;
580 		queue->rx_irq = err;
581 		disable_irq(queue->rx_irq);
582 	}
583 
584 	queue->stalled = true;
585 
586 	task = kthread_create(xenvif_kthread_guest_rx,
587 			      (void *)queue, "%s-guest-rx", queue->name);
588 	if (IS_ERR(task)) {
589 		pr_warn("Could not allocate kthread for %s\n", queue->name);
590 		err = PTR_ERR(task);
591 		goto err_rx_unbind;
592 	}
593 	queue->task = task;
594 	get_task_struct(task);
595 
596 	task = kthread_create(xenvif_dealloc_kthread,
597 			      (void *)queue, "%s-dealloc", queue->name);
598 	if (IS_ERR(task)) {
599 		pr_warn("Could not allocate kthread for %s\n", queue->name);
600 		err = PTR_ERR(task);
601 		goto err_rx_unbind;
602 	}
603 	queue->dealloc_task = task;
604 
605 	wake_up_process(queue->task);
606 	wake_up_process(queue->dealloc_task);
607 
608 	return 0;
609 
610 err_rx_unbind:
611 	unbind_from_irqhandler(queue->rx_irq, queue);
612 	queue->rx_irq = 0;
613 err_tx_unbind:
614 	unbind_from_irqhandler(queue->tx_irq, queue);
615 	queue->tx_irq = 0;
616 err_unmap:
617 	xenvif_unmap_frontend_rings(queue);
618 err:
619 	module_put(THIS_MODULE);
620 	return err;
621 }
622 
623 void xenvif_carrier_off(struct xenvif *vif)
624 {
625 	struct net_device *dev = vif->dev;
626 
627 	rtnl_lock();
628 	if (test_and_clear_bit(VIF_STATUS_CONNECTED, &vif->status)) {
629 		netif_carrier_off(dev); /* discard queued packets */
630 		if (netif_running(dev))
631 			xenvif_down(vif);
632 	}
633 	rtnl_unlock();
634 }
635 
636 void xenvif_disconnect(struct xenvif *vif)
637 {
638 	struct xenvif_queue *queue = NULL;
639 	unsigned int num_queues = vif->num_queues;
640 	unsigned int queue_index;
641 
642 	xenvif_carrier_off(vif);
643 
644 	for (queue_index = 0; queue_index < num_queues; ++queue_index) {
645 		queue = &vif->queues[queue_index];
646 
647 		netif_napi_del(&queue->napi);
648 
649 		if (queue->task) {
650 			kthread_stop(queue->task);
651 			put_task_struct(queue->task);
652 			queue->task = NULL;
653 		}
654 
655 		if (queue->dealloc_task) {
656 			kthread_stop(queue->dealloc_task);
657 			queue->dealloc_task = NULL;
658 		}
659 
660 		if (queue->tx_irq) {
661 			if (queue->tx_irq == queue->rx_irq)
662 				unbind_from_irqhandler(queue->tx_irq, queue);
663 			else {
664 				unbind_from_irqhandler(queue->tx_irq, queue);
665 				unbind_from_irqhandler(queue->rx_irq, queue);
666 			}
667 			queue->tx_irq = 0;
668 		}
669 
670 		xenvif_unmap_frontend_rings(queue);
671 	}
672 
673 	xenvif_mcast_addr_list_free(vif);
674 }
675 
676 /* Reverse the relevant parts of xenvif_init_queue().
677  * Used for queue teardown from xenvif_free(), and on the
678  * error handling paths in xenbus.c:connect().
679  */
680 void xenvif_deinit_queue(struct xenvif_queue *queue)
681 {
682 	gnttab_free_pages(MAX_PENDING_REQS, queue->mmap_pages);
683 }
684 
685 void xenvif_free(struct xenvif *vif)
686 {
687 	struct xenvif_queue *queue = NULL;
688 	unsigned int num_queues = vif->num_queues;
689 	unsigned int queue_index;
690 
691 	unregister_netdev(vif->dev);
692 
693 	for (queue_index = 0; queue_index < num_queues; ++queue_index) {
694 		queue = &vif->queues[queue_index];
695 		xenvif_deinit_queue(queue);
696 	}
697 
698 	vfree(vif->queues);
699 	vif->queues = NULL;
700 	vif->num_queues = 0;
701 
702 	free_netdev(vif->dev);
703 
704 	module_put(THIS_MODULE);
705 }
706