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/sched/task.h>
 35#include <linux/ethtool.h>
 36#include <linux/rtnetlink.h>
 37#include <linux/if_vlan.h>
 38#include <linux/vmalloc.h>
 39
 40#include <xen/events.h>
 41#include <asm/xen/hypercall.h>
 42#include <xen/balloon.h>
 43
 
 
 
 44/* Number of bytes allowed on the internal guest Rx queue. */
 45#define XENVIF_RX_QUEUE_BYTES (XEN_NETIF_RX_RING_SIZE/2 * PAGE_SIZE)
 46
 47/* This function is used to set SKBFL_ZEROCOPY_ENABLE as well as
 48 * increasing the inflight counter. We need to increase the inflight
 49 * counter because core driver calls into xenvif_zerocopy_callback
 50 * which calls xenvif_skb_zerocopy_complete.
 51 */
 52void xenvif_skb_zerocopy_prepare(struct xenvif_queue *queue,
 53				 struct sk_buff *skb)
 54{
 55	skb_shinfo(skb)->flags |= SKBFL_ZEROCOPY_ENABLE;
 56	atomic_inc(&queue->inflight_packets);
 57}
 58
 59void xenvif_skb_zerocopy_complete(struct xenvif_queue *queue)
 60{
 61	atomic_dec(&queue->inflight_packets);
 62
 63	/* Wake the dealloc thread _after_ decrementing inflight_packets so
 64	 * that if kthread_stop() has already been called, the dealloc thread
 65	 * does not wait forever with nothing to wake it.
 66	 */
 67	wake_up(&queue->dealloc_wq);
 68}
 69
 70static int xenvif_schedulable(struct xenvif *vif)
 71{
 72	return netif_running(vif->dev) &&
 73		test_bit(VIF_STATUS_CONNECTED, &vif->status) &&
 74		!vif->disabled;
 75}
 76
 77static bool xenvif_handle_tx_interrupt(struct xenvif_queue *queue)
 78{
 79	bool rc;
 80
 81	rc = RING_HAS_UNCONSUMED_REQUESTS(&queue->tx);
 82	if (rc)
 83		napi_schedule(&queue->napi);
 84	return rc;
 85}
 86
 87static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
 88{
 89	struct xenvif_queue *queue = dev_id;
 90	int old;
 91
 92	old = atomic_fetch_or(NETBK_TX_EOI, &queue->eoi_pending);
 93	WARN(old & NETBK_TX_EOI, "Interrupt while EOI pending\n");
 94
 95	if (!xenvif_handle_tx_interrupt(queue)) {
 96		atomic_andnot(NETBK_TX_EOI, &queue->eoi_pending);
 97		xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS);
 98	}
 99
100	return IRQ_HANDLED;
101}
102
103static int xenvif_poll(struct napi_struct *napi, int budget)
104{
105	struct xenvif_queue *queue =
106		container_of(napi, struct xenvif_queue, napi);
107	int work_done;
108
109	/* This vif is rogue, we pretend we've there is nothing to do
110	 * for this vif to deschedule it from NAPI. But this interface
111	 * will be turned off in thread context later.
112	 */
113	if (unlikely(queue->vif->disabled)) {
114		napi_complete(napi);
115		return 0;
116	}
117
118	work_done = xenvif_tx_action(queue, budget);
119
120	if (work_done < budget) {
121		napi_complete_done(napi, work_done);
122		/* If the queue is rate-limited, it shall be
123		 * rescheduled in the timer callback.
124		 */
125		if (likely(!queue->rate_limited))
126			xenvif_napi_schedule_or_enable_events(queue);
127	}
128
129	return work_done;
130}
131
132static bool xenvif_handle_rx_interrupt(struct xenvif_queue *queue)
133{
134	bool rc;
135
136	rc = xenvif_have_rx_work(queue, false);
137	if (rc)
138		xenvif_kick_thread(queue);
139	return rc;
140}
141
142static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
143{
144	struct xenvif_queue *queue = dev_id;
145	int old;
146
147	old = atomic_fetch_or(NETBK_RX_EOI, &queue->eoi_pending);
148	WARN(old & NETBK_RX_EOI, "Interrupt while EOI pending\n");
149
150	if (!xenvif_handle_rx_interrupt(queue)) {
151		atomic_andnot(NETBK_RX_EOI, &queue->eoi_pending);
152		xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS);
153	}
154
155	return IRQ_HANDLED;
156}
157
158irqreturn_t xenvif_interrupt(int irq, void *dev_id)
159{
160	struct xenvif_queue *queue = dev_id;
161	int old;
162	bool has_rx, has_tx;
163
164	old = atomic_fetch_or(NETBK_COMMON_EOI, &queue->eoi_pending);
165	WARN(old, "Interrupt while EOI pending\n");
166
167	has_tx = xenvif_handle_tx_interrupt(queue);
168	has_rx = xenvif_handle_rx_interrupt(queue);
169
170	if (!has_rx && !has_tx) {
171		atomic_andnot(NETBK_COMMON_EOI, &queue->eoi_pending);
172		xen_irq_lateeoi(irq, XEN_EOI_FLAG_SPURIOUS);
173	}
 
 
174
175	return IRQ_HANDLED;
 
 
 
 
176}
177
178static u16 xenvif_select_queue(struct net_device *dev, struct sk_buff *skb,
179			       struct net_device *sb_dev)
180{
181	struct xenvif *vif = netdev_priv(dev);
182	unsigned int size = vif->hash.size;
183	unsigned int num_queues;
184
185	/* If queues are not set up internally - always return 0
186	 * as the packet going to be dropped anyway */
187	num_queues = READ_ONCE(vif->num_queues);
188	if (num_queues < 1)
189		return 0;
190
191	if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE)
192		return netdev_pick_tx(dev, skb, NULL) %
193		       dev->real_num_tx_queues;
194
195	xenvif_set_skb_hash(vif, skb);
196
197	if (size == 0)
198		return skb_get_hash_raw(skb) % dev->real_num_tx_queues;
199
200	return vif->hash.mapping[vif->hash.mapping_sel]
201				[skb_get_hash_raw(skb) % size];
202}
203
204static netdev_tx_t
205xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
206{
207	struct xenvif *vif = netdev_priv(dev);
208	struct xenvif_queue *queue = NULL;
209	unsigned int num_queues;
210	u16 index;
211	struct xenvif_rx_cb *cb;
212
213	BUG_ON(skb->dev != dev);
214
215	/* Drop the packet if queues are not set up.
216	 * This handler should be called inside an RCU read section
217	 * so we don't need to enter it here explicitly.
218	 */
219	num_queues = READ_ONCE(vif->num_queues);
220	if (num_queues < 1)
221		goto drop;
222
223	/* Obtain the queue to be used to transmit this packet */
224	index = skb_get_queue_mapping(skb);
225	if (index >= num_queues) {
226		pr_warn_ratelimited("Invalid queue %hu for packet on interface %s\n",
227				    index, vif->dev->name);
228		index %= num_queues;
229	}
230	queue = &vif->queues[index];
231
232	/* Drop the packet if queue is not ready */
233	if (queue->task == NULL ||
234	    queue->dealloc_task == NULL ||
235	    !xenvif_schedulable(vif))
236		goto drop;
237
238	if (vif->multicast_control && skb->pkt_type == PACKET_MULTICAST) {
239		struct ethhdr *eth = (struct ethhdr *)skb->data;
240
241		if (!xenvif_mcast_match(vif, eth->h_dest))
242			goto drop;
243	}
244
245	cb = XENVIF_RX_CB(skb);
246	cb->expires = jiffies + vif->drain_timeout;
247
248	/* If there is no hash algorithm configured then make sure there
249	 * is no hash information in the socket buffer otherwise it
250	 * would be incorrectly forwarded to the frontend.
251	 */
252	if (vif->hash.alg == XEN_NETIF_CTRL_HASH_ALGORITHM_NONE)
253		skb_clear_hash(skb);
254
255	/* timestamp packet in software */
256	skb_tx_timestamp(skb);
257
258	if (!xenvif_rx_queue_tail(queue, skb))
259		goto drop;
260
261	xenvif_kick_thread(queue);
262
263	return NETDEV_TX_OK;
264
265 drop:
266	vif->dev->stats.tx_dropped++;
267	dev_kfree_skb_any(skb);
268	return NETDEV_TX_OK;
269}
270
271static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
272{
273	struct xenvif *vif = netdev_priv(dev);
274	struct xenvif_queue *queue = NULL;
275	unsigned int num_queues;
276	u64 rx_bytes = 0;
277	u64 rx_packets = 0;
278	u64 tx_bytes = 0;
279	u64 tx_packets = 0;
280	unsigned int index;
281
282	rcu_read_lock();
283	num_queues = READ_ONCE(vif->num_queues);
284
285	/* Aggregate tx and rx stats from each queue */
286	for (index = 0; index < num_queues; ++index) {
287		queue = &vif->queues[index];
288		rx_bytes += queue->stats.rx_bytes;
289		rx_packets += queue->stats.rx_packets;
290		tx_bytes += queue->stats.tx_bytes;
291		tx_packets += queue->stats.tx_packets;
292	}
293
294	rcu_read_unlock();
295
296	vif->dev->stats.rx_bytes = rx_bytes;
297	vif->dev->stats.rx_packets = rx_packets;
298	vif->dev->stats.tx_bytes = tx_bytes;
299	vif->dev->stats.tx_packets = tx_packets;
300
301	return &vif->dev->stats;
302}
303
304static void xenvif_up(struct xenvif *vif)
305{
306	struct xenvif_queue *queue = NULL;
307	unsigned int num_queues = vif->num_queues;
308	unsigned int queue_index;
309
310	for (queue_index = 0; queue_index < num_queues; ++queue_index) {
311		queue = &vif->queues[queue_index];
312		napi_enable(&queue->napi);
313		enable_irq(queue->tx_irq);
314		if (queue->tx_irq != queue->rx_irq)
315			enable_irq(queue->rx_irq);
316		xenvif_napi_schedule_or_enable_events(queue);
317	}
318}
319
320static void xenvif_down(struct xenvif *vif)
321{
322	struct xenvif_queue *queue = NULL;
323	unsigned int num_queues = vif->num_queues;
324	unsigned int queue_index;
325
326	for (queue_index = 0; queue_index < num_queues; ++queue_index) {
327		queue = &vif->queues[queue_index];
328		disable_irq(queue->tx_irq);
329		if (queue->tx_irq != queue->rx_irq)
330			disable_irq(queue->rx_irq);
331		napi_disable(&queue->napi);
332		del_timer_sync(&queue->credit_timeout);
333	}
334}
335
336static int xenvif_open(struct net_device *dev)
337{
338	struct xenvif *vif = netdev_priv(dev);
339	if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
340		xenvif_up(vif);
341	netif_tx_start_all_queues(dev);
342	return 0;
343}
344
345static int xenvif_close(struct net_device *dev)
346{
347	struct xenvif *vif = netdev_priv(dev);
348	if (test_bit(VIF_STATUS_CONNECTED, &vif->status))
349		xenvif_down(vif);
350	netif_tx_stop_all_queues(dev);
351	return 0;
352}
353
354static int xenvif_change_mtu(struct net_device *dev, int mtu)
355{
356	struct xenvif *vif = netdev_priv(dev);
357	int max = vif->can_sg ? ETH_MAX_MTU - VLAN_ETH_HLEN : ETH_DATA_LEN;
358
359	if (mtu > max)
360		return -EINVAL;
361	dev->mtu = mtu;
362	return 0;
363}
364
365static netdev_features_t xenvif_fix_features(struct net_device *dev,
366	netdev_features_t features)
367{
368	struct xenvif *vif = netdev_priv(dev);
369
370	if (!vif->can_sg)
371		features &= ~NETIF_F_SG;
372	if (~(vif->gso_mask) & GSO_BIT(TCPV4))
373		features &= ~NETIF_F_TSO;
374	if (~(vif->gso_mask) & GSO_BIT(TCPV6))
375		features &= ~NETIF_F_TSO6;
376	if (!vif->ip_csum)
377		features &= ~NETIF_F_IP_CSUM;
378	if (!vif->ipv6_csum)
379		features &= ~NETIF_F_IPV6_CSUM;
380
381	return features;
382}
383
384static const struct xenvif_stat {
385	char name[ETH_GSTRING_LEN];
386	u16 offset;
387} xenvif_stats[] = {
388	{
389		"rx_gso_checksum_fixup",
390		offsetof(struct xenvif_stats, rx_gso_checksum_fixup)
391	},
392	/* If (sent != success + fail), there are probably packets never
393	 * freed up properly!
394	 */
395	{
396		"tx_zerocopy_sent",
397		offsetof(struct xenvif_stats, tx_zerocopy_sent),
398	},
399	{
400		"tx_zerocopy_success",
401		offsetof(struct xenvif_stats, tx_zerocopy_success),
402	},
403	{
404		"tx_zerocopy_fail",
405		offsetof(struct xenvif_stats, tx_zerocopy_fail)
406	},
407	/* Number of packets exceeding MAX_SKB_FRAG slots. You should use
408	 * a guest with the same MAX_SKB_FRAG
409	 */
410	{
411		"tx_frag_overflow",
412		offsetof(struct xenvif_stats, tx_frag_overflow)
413	},
414};
415
416static int xenvif_get_sset_count(struct net_device *dev, int string_set)
417{
418	switch (string_set) {
419	case ETH_SS_STATS:
420		return ARRAY_SIZE(xenvif_stats);
421	default:
422		return -EINVAL;
423	}
424}
425
426static void xenvif_get_ethtool_stats(struct net_device *dev,
427				     struct ethtool_stats *stats, u64 * data)
428{
429	struct xenvif *vif = netdev_priv(dev);
430	unsigned int num_queues;
431	int i;
432	unsigned int queue_index;
433
434	rcu_read_lock();
435	num_queues = READ_ONCE(vif->num_queues);
436
437	for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++) {
438		unsigned long accum = 0;
439		for (queue_index = 0; queue_index < num_queues; ++queue_index) {
440			void *vif_stats = &vif->queues[queue_index].stats;
441			accum += *(unsigned long *)(vif_stats + xenvif_stats[i].offset);
442		}
443		data[i] = accum;
444	}
445
446	rcu_read_unlock();
447}
448
449static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
450{
451	int i;
452
453	switch (stringset) {
454	case ETH_SS_STATS:
455		for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
456			memcpy(data + i * ETH_GSTRING_LEN,
457			       xenvif_stats[i].name, ETH_GSTRING_LEN);
458		break;
459	}
460}
461
462static const struct ethtool_ops xenvif_ethtool_ops = {
463	.get_link	= ethtool_op_get_link,
464	.get_ts_info 	= ethtool_op_get_ts_info,
465	.get_sset_count = xenvif_get_sset_count,
466	.get_ethtool_stats = xenvif_get_ethtool_stats,
467	.get_strings = xenvif_get_strings,
468};
469
470static const struct net_device_ops xenvif_netdev_ops = {
471	.ndo_select_queue = xenvif_select_queue,
472	.ndo_start_xmit	= xenvif_start_xmit,
473	.ndo_get_stats	= xenvif_get_stats,
474	.ndo_open	= xenvif_open,
475	.ndo_stop	= xenvif_close,
476	.ndo_change_mtu	= xenvif_change_mtu,
477	.ndo_fix_features = xenvif_fix_features,
478	.ndo_set_mac_address = eth_mac_addr,
479	.ndo_validate_addr   = eth_validate_addr,
480};
481
482struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
483			    unsigned int handle)
484{
485	static const u8 dummy_addr[ETH_ALEN] = {
486		0xfe, 0xff, 0xff, 0xff, 0xff, 0xff,
487	};
488	int err;
489	struct net_device *dev;
490	struct xenvif *vif;
491	char name[IFNAMSIZ] = {};
492
493	snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
494	/* Allocate a netdev with the max. supported number of queues.
495	 * When the guest selects the desired number, it will be updated
496	 * via netif_set_real_num_*_queues().
497	 */
498	dev = alloc_netdev_mq(sizeof(struct xenvif), name, NET_NAME_UNKNOWN,
499			      ether_setup, xenvif_max_queues);
500	if (dev == NULL) {
501		pr_warn("Could not allocate netdev for %s\n", name);
502		return ERR_PTR(-ENOMEM);
503	}
504
505	SET_NETDEV_DEV(dev, parent);
506
507	vif = netdev_priv(dev);
508
509	vif->domid  = domid;
510	vif->handle = handle;
511	vif->can_sg = 1;
512	vif->ip_csum = 1;
513	vif->dev = dev;
514	vif->disabled = false;
515	vif->drain_timeout = msecs_to_jiffies(rx_drain_timeout_msecs);
516	vif->stall_timeout = msecs_to_jiffies(rx_stall_timeout_msecs);
517
518	/* Start out with no queues. */
519	vif->queues = NULL;
520	vif->num_queues = 0;
521
522	vif->xdp_headroom = 0;
523
524	spin_lock_init(&vif->lock);
525	INIT_LIST_HEAD(&vif->fe_mcast_addr);
526
527	dev->netdev_ops	= &xenvif_netdev_ops;
528	dev->hw_features = NETIF_F_SG |
529		NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
530		NETIF_F_TSO | NETIF_F_TSO6 | NETIF_F_FRAGLIST;
531	dev->features = dev->hw_features | NETIF_F_RXCSUM;
532	dev->ethtool_ops = &xenvif_ethtool_ops;
533
 
 
534	dev->min_mtu = ETH_MIN_MTU;
535	dev->max_mtu = ETH_MAX_MTU - VLAN_ETH_HLEN;
536
537	/*
538	 * Initialise a dummy MAC address. We choose the numerically
539	 * largest non-broadcast address to prevent the address getting
540	 * stolen by an Ethernet bridge for STP purposes.
541	 * (FE:FF:FF:FF:FF:FF)
542	 */
543	eth_hw_addr_set(dev, dummy_addr);
 
544
545	netif_carrier_off(dev);
546
547	err = register_netdev(dev);
548	if (err) {
549		netdev_warn(dev, "Could not register device: err=%d\n", err);
550		free_netdev(dev);
551		return ERR_PTR(err);
552	}
553
554	netdev_dbg(dev, "Successfully created xenvif\n");
555
556	__module_get(THIS_MODULE);
557
558	return vif;
559}
560
561int xenvif_init_queue(struct xenvif_queue *queue)
562{
563	int err, i;
564
565	queue->credit_bytes = queue->remaining_credit = ~0UL;
566	queue->credit_usec  = 0UL;
567	timer_setup(&queue->credit_timeout, xenvif_tx_credit_callback, 0);
568	queue->credit_window_start = get_jiffies_64();
569
570	queue->rx_queue_max = XENVIF_RX_QUEUE_BYTES;
571
572	skb_queue_head_init(&queue->rx_queue);
573	skb_queue_head_init(&queue->tx_queue);
574
575	queue->pending_cons = 0;
576	queue->pending_prod = MAX_PENDING_REQS;
577	for (i = 0; i < MAX_PENDING_REQS; ++i)
578		queue->pending_ring[i] = i;
579
580	spin_lock_init(&queue->callback_lock);
581	spin_lock_init(&queue->response_lock);
582
583	/* If ballooning is disabled, this will consume real memory, so you
584	 * better enable it. The long term solution would be to use just a
585	 * bunch of valid page descriptors, without dependency on ballooning
586	 */
587	err = gnttab_alloc_pages(MAX_PENDING_REQS,
588				 queue->mmap_pages);
589	if (err) {
590		netdev_err(queue->vif->dev, "Could not reserve mmap_pages\n");
591		return -ENOMEM;
592	}
593
594	for (i = 0; i < MAX_PENDING_REQS; i++) {
595		queue->pending_tx_info[i].callback_struct = (struct ubuf_info_msgzc)
596			{ { .callback = xenvif_zerocopy_callback },
597			  { { .ctx = NULL,
598			      .desc = i } } };
599		queue->grant_tx_handle[i] = NETBACK_INVALID_HANDLE;
600	}
601
602	return 0;
603}
604
605void xenvif_carrier_on(struct xenvif *vif)
606{
607	rtnl_lock();
608	if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
609		dev_set_mtu(vif->dev, ETH_DATA_LEN);
610	netdev_update_features(vif->dev);
611	set_bit(VIF_STATUS_CONNECTED, &vif->status);
612	if (netif_running(vif->dev))
613		xenvif_up(vif);
614	rtnl_unlock();
615}
616
617int xenvif_connect_ctrl(struct xenvif *vif, grant_ref_t ring_ref,
618			unsigned int evtchn)
619{
620	struct net_device *dev = vif->dev;
621	struct xenbus_device *xendev = xenvif_to_xenbus_device(vif);
622	void *addr;
623	struct xen_netif_ctrl_sring *shared;
624	RING_IDX rsp_prod, req_prod;
625	int err;
626
627	err = xenbus_map_ring_valloc(xendev, &ring_ref, 1, &addr);
 
628	if (err)
629		goto err;
630
631	shared = (struct xen_netif_ctrl_sring *)addr;
632	rsp_prod = READ_ONCE(shared->rsp_prod);
633	req_prod = READ_ONCE(shared->req_prod);
634
635	BACK_RING_ATTACH(&vif->ctrl, shared, rsp_prod, XEN_PAGE_SIZE);
636
637	err = -EIO;
638	if (req_prod - rsp_prod > RING_SIZE(&vif->ctrl))
639		goto err_unmap;
640
641	err = bind_interdomain_evtchn_to_irq_lateeoi(xendev, evtchn);
642	if (err < 0)
643		goto err_unmap;
644
645	vif->ctrl_irq = err;
646
647	xenvif_init_hash(vif);
648
649	err = request_threaded_irq(vif->ctrl_irq, NULL, xenvif_ctrl_irq_fn,
650				   IRQF_ONESHOT, "xen-netback-ctrl", vif);
651	if (err) {
652		pr_warn("Could not setup irq handler for %s\n", dev->name);
653		goto err_deinit;
654	}
655
656	return 0;
657
658err_deinit:
659	xenvif_deinit_hash(vif);
660	unbind_from_irqhandler(vif->ctrl_irq, vif);
661	vif->ctrl_irq = 0;
662
663err_unmap:
664	xenbus_unmap_ring_vfree(xendev, vif->ctrl.sring);
 
665	vif->ctrl.sring = NULL;
666
667err:
668	return err;
669}
670
671static void xenvif_disconnect_queue(struct xenvif_queue *queue)
672{
673	if (queue->task) {
674		kthread_stop_put(queue->task);
675		queue->task = NULL;
676	}
677
678	if (queue->dealloc_task) {
679		kthread_stop(queue->dealloc_task);
680		queue->dealloc_task = NULL;
681	}
682
683	if (queue->napi.poll) {
684		netif_napi_del(&queue->napi);
685		queue->napi.poll = NULL;
686	}
687
688	if (queue->tx_irq) {
689		unbind_from_irqhandler(queue->tx_irq, queue);
690		if (queue->tx_irq == queue->rx_irq)
691			queue->rx_irq = 0;
692		queue->tx_irq = 0;
693	}
694
695	if (queue->rx_irq) {
696		unbind_from_irqhandler(queue->rx_irq, queue);
697		queue->rx_irq = 0;
698	}
699
700	xenvif_unmap_frontend_data_rings(queue);
701}
702
703int xenvif_connect_data(struct xenvif_queue *queue,
704			unsigned long tx_ring_ref,
705			unsigned long rx_ring_ref,
706			unsigned int tx_evtchn,
707			unsigned int rx_evtchn)
708{
709	struct xenbus_device *dev = xenvif_to_xenbus_device(queue->vif);
710	struct task_struct *task;
711	int err;
712
713	BUG_ON(queue->tx_irq);
714	BUG_ON(queue->task);
715	BUG_ON(queue->dealloc_task);
716
717	err = xenvif_map_frontend_data_rings(queue, tx_ring_ref,
718					     rx_ring_ref);
719	if (err < 0)
720		goto err;
721
722	init_waitqueue_head(&queue->wq);
723	init_waitqueue_head(&queue->dealloc_wq);
724	atomic_set(&queue->inflight_packets, 0);
725
726	netif_napi_add(queue->vif->dev, &queue->napi, xenvif_poll);
 
727
728	queue->stalled = true;
729
730	task = kthread_run(xenvif_kthread_guest_rx, queue,
731			   "%s-guest-rx", queue->name);
732	if (IS_ERR(task))
733		goto kthread_err;
734	queue->task = task;
735	/*
736	 * Take a reference to the task in order to prevent it from being freed
737	 * if the thread function returns before kthread_stop is called.
738	 */
739	get_task_struct(task);
740
741	task = kthread_run(xenvif_dealloc_kthread, queue,
742			   "%s-dealloc", queue->name);
743	if (IS_ERR(task))
744		goto kthread_err;
745	queue->dealloc_task = task;
746
747	if (tx_evtchn == rx_evtchn) {
748		/* feature-split-event-channels == 0 */
749		err = bind_interdomain_evtchn_to_irqhandler_lateeoi(
750			dev, tx_evtchn, xenvif_interrupt, 0,
751			queue->name, queue);
752		if (err < 0)
753			goto err;
754		queue->tx_irq = queue->rx_irq = err;
755		disable_irq(queue->tx_irq);
756	} else {
757		/* feature-split-event-channels == 1 */
758		snprintf(queue->tx_irq_name, sizeof(queue->tx_irq_name),
759			 "%s-tx", queue->name);
760		err = bind_interdomain_evtchn_to_irqhandler_lateeoi(
761			dev, tx_evtchn, xenvif_tx_interrupt, 0,
762			queue->tx_irq_name, queue);
763		if (err < 0)
764			goto err;
765		queue->tx_irq = err;
766		disable_irq(queue->tx_irq);
767
768		snprintf(queue->rx_irq_name, sizeof(queue->rx_irq_name),
769			 "%s-rx", queue->name);
770		err = bind_interdomain_evtchn_to_irqhandler_lateeoi(
771			dev, rx_evtchn, xenvif_rx_interrupt, 0,
772			queue->rx_irq_name, queue);
773		if (err < 0)
774			goto err;
775		queue->rx_irq = err;
776		disable_irq(queue->rx_irq);
777	}
778
779	return 0;
780
781kthread_err:
782	pr_warn("Could not allocate kthread for %s\n", queue->name);
783	err = PTR_ERR(task);
784err:
785	xenvif_disconnect_queue(queue);
786	return err;
787}
788
789void xenvif_carrier_off(struct xenvif *vif)
790{
791	struct net_device *dev = vif->dev;
792
793	rtnl_lock();
794	if (test_and_clear_bit(VIF_STATUS_CONNECTED, &vif->status)) {
795		netif_carrier_off(dev); /* discard queued packets */
796		if (netif_running(dev))
797			xenvif_down(vif);
798	}
799	rtnl_unlock();
800}
801
802void xenvif_disconnect_data(struct xenvif *vif)
803{
804	struct xenvif_queue *queue = NULL;
805	unsigned int num_queues = vif->num_queues;
806	unsigned int queue_index;
807
808	xenvif_carrier_off(vif);
809
810	for (queue_index = 0; queue_index < num_queues; ++queue_index) {
811		queue = &vif->queues[queue_index];
812
813		xenvif_disconnect_queue(queue);
814	}
815
816	xenvif_mcast_addr_list_free(vif);
817}
818
819void xenvif_disconnect_ctrl(struct xenvif *vif)
820{
821	if (vif->ctrl_irq) {
822		xenvif_deinit_hash(vif);
823		unbind_from_irqhandler(vif->ctrl_irq, vif);
824		vif->ctrl_irq = 0;
825	}
826
827	if (vif->ctrl.sring) {
828		xenbus_unmap_ring_vfree(xenvif_to_xenbus_device(vif),
829					vif->ctrl.sring);
830		vif->ctrl.sring = NULL;
831	}
832}
833
834/* Reverse the relevant parts of xenvif_init_queue().
835 * Used for queue teardown from xenvif_free(), and on the
836 * error handling paths in xenbus.c:connect().
837 */
838void xenvif_deinit_queue(struct xenvif_queue *queue)
839{
840	gnttab_free_pages(MAX_PENDING_REQS, queue->mmap_pages);
841}
842
843void xenvif_free(struct xenvif *vif)
844{
845	struct xenvif_queue *queues = vif->queues;
846	unsigned int num_queues = vif->num_queues;
847	unsigned int queue_index;
848
849	unregister_netdev(vif->dev);
850	free_netdev(vif->dev);
851
852	for (queue_index = 0; queue_index < num_queues; ++queue_index)
853		xenvif_deinit_queue(&queues[queue_index]);
854	vfree(queues);
855
856	module_put(THIS_MODULE);
857}