[mirror_ubuntu-jammy-kernel.git] / drivers / net / xen-netback / interface.c

/*
 * Network-device interface management.
 *
 * Copyright (c) 2004-2005, Keir Fraser
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation; or, when distributed
 * separately from the Linux kernel or incorporated into other
 * software packages, subject to the following license:
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this source file (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include "common.h"

#include <linux/ethtool.h>
#include <linux/rtnetlink.h>
#include <linux/if_vlan.h>

#include <xen/events.h>
#include <asm/xen/hypercall.h>

#define XENVIF_QUEUE_LENGTH 32

void xenvif_get(struct xenvif *vif)
{
	atomic_inc(&vif->refcnt);
}

void xenvif_put(struct xenvif *vif)
{
	if (atomic_dec_and_test(&vif->refcnt))
		wake_up(&vif->waiting_to_free);
}

int xenvif_schedulable(struct xenvif *vif)
{
	return netif_running(vif->dev) && netif_carrier_ok(vif->dev);
}

static int xenvif_rx_schedulable(struct xenvif *vif)
{
	return xenvif_schedulable(vif) && !xen_netbk_rx_ring_full(vif);
}

static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
{
	struct xenvif *vif = dev_id;

	if (vif->netbk == NULL)
		return IRQ_NONE;

	xen_netbk_schedule_xenvif(vif);

	if (xenvif_rx_schedulable(vif))
		netif_wake_queue(vif->dev);

	return IRQ_HANDLED;
}

static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
{
	struct xenvif *vif = netdev_priv(dev);

	BUG_ON(skb->dev != dev);

	if (vif->netbk == NULL)
		goto drop;

	/* Drop the packet if the target domain has no receive buffers. */
	if (!xenvif_rx_schedulable(vif))
		goto drop;

	/* Reserve ring slots for the worst-case number of fragments. */
	vif->rx_req_cons_peek += xen_netbk_count_skb_slots(vif, skb);
	xenvif_get(vif);

	if (vif->can_queue && xen_netbk_must_stop_queue(vif))
		netif_stop_queue(dev);

	xen_netbk_queue_tx_skb(vif, skb);

	return NETDEV_TX_OK;

 drop:
	vif->dev->stats.tx_dropped++;
	dev_kfree_skb(skb);
	return NETDEV_TX_OK;
}

void xenvif_receive_skb(struct xenvif *vif, struct sk_buff *skb)
{
	netif_rx_ni(skb);
}

void xenvif_notify_tx_completion(struct xenvif *vif)
{
	if (netif_queue_stopped(vif->dev) && xenvif_rx_schedulable(vif))
		netif_wake_queue(vif->dev);
}

static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
{
	struct xenvif *vif = netdev_priv(dev);
	return &vif->dev->stats;
}

static void xenvif_up(struct xenvif *vif)
{
	xen_netbk_add_xenvif(vif);
	enable_irq(vif->irq);
	xen_netbk_check_rx_xenvif(vif);
}

static void xenvif_down(struct xenvif *vif)
{
	disable_irq(vif->irq);
	xen_netbk_deschedule_xenvif(vif);
	xen_netbk_remove_xenvif(vif);
}

static int xenvif_open(struct net_device *dev)
{
	struct xenvif *vif = netdev_priv(dev);
	if (netif_carrier_ok(dev))
		xenvif_up(vif);
	netif_start_queue(dev);
	return 0;
}

static int xenvif_close(struct net_device *dev)
{
	struct xenvif *vif = netdev_priv(dev);
	if (netif_carrier_ok(dev))
		xenvif_down(vif);
	netif_stop_queue(dev);
	return 0;
}

static int xenvif_change_mtu(struct net_device *dev, int mtu)
{
	struct xenvif *vif = netdev_priv(dev);
	int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN;

	if (mtu > max)
		return -EINVAL;
	dev->mtu = mtu;
	return 0;
}

static void xenvif_set_features(struct xenvif *vif)
{
	struct net_device *dev = vif->dev;
	u32 features = dev->features;

	if (vif->can_sg)
		features |= NETIF_F_SG;
	if (vif->gso || vif->gso_prefix)
		features |= NETIF_F_TSO;
	if (vif->csum)
		features |= NETIF_F_IP_CSUM;

	features &= ~(vif->features_disabled);

	if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN)
		dev->mtu = ETH_DATA_LEN;

	dev->features = features;
}

static int xenvif_set_tx_csum(struct net_device *dev, u32 data)
{
	struct xenvif *vif = netdev_priv(dev);
	if (data) {
		if (!vif->csum)
			return -EOPNOTSUPP;
		vif->features_disabled &= ~NETIF_F_IP_CSUM;
	} else {
		vif->features_disabled |= NETIF_F_IP_CSUM;
	}

	xenvif_set_features(vif);
	return 0;
}

static int xenvif_set_sg(struct net_device *dev, u32 data)
{
	struct xenvif *vif = netdev_priv(dev);
	if (data) {
		if (!vif->can_sg)
			return -EOPNOTSUPP;
		vif->features_disabled &= ~NETIF_F_SG;
	} else {
		vif->features_disabled |= NETIF_F_SG;
	}

	xenvif_set_features(vif);
	return 0;
}

static int xenvif_set_tso(struct net_device *dev, u32 data)
{
	struct xenvif *vif = netdev_priv(dev);
	if (data) {
		if (!vif->gso && !vif->gso_prefix)
			return -EOPNOTSUPP;
		vif->features_disabled &= ~NETIF_F_TSO;
	} else {
		vif->features_disabled |= NETIF_F_TSO;
	}

	xenvif_set_features(vif);
	return 0;
}

static const struct xenvif_stat {
	char name[ETH_GSTRING_LEN];
	u16 offset;
} xenvif_stats[] = {
	{
		"rx_gso_checksum_fixup",
		offsetof(struct xenvif, rx_gso_checksum_fixup)
	},
};

static int xenvif_get_sset_count(struct net_device *dev, int string_set)
{
	switch (string_set) {
	case ETH_SS_STATS:
		return ARRAY_SIZE(xenvif_stats);
	default:
		return -EINVAL;
	}
}

static void xenvif_get_ethtool_stats(struct net_device *dev,
				     struct ethtool_stats *stats, u64 * data)
{
	void *vif = netdev_priv(dev);
	int i;

	for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
		data[i] = *(unsigned long *)(vif + xenvif_stats[i].offset);
}

static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
{
	int i;

	switch (stringset) {
	case ETH_SS_STATS:
		for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
			memcpy(data + i * ETH_GSTRING_LEN,
			       xenvif_stats[i].name, ETH_GSTRING_LEN);
		break;
	}
}

static struct ethtool_ops xenvif_ethtool_ops = {
	.get_tx_csum	= ethtool_op_get_tx_csum,
	.set_tx_csum	= xenvif_set_tx_csum,
	.get_sg		= ethtool_op_get_sg,
	.set_sg		= xenvif_set_sg,
	.get_tso	= ethtool_op_get_tso,
	.set_tso	= xenvif_set_tso,
	.get_link	= ethtool_op_get_link,

	.get_sset_count = xenvif_get_sset_count,
	.get_ethtool_stats = xenvif_get_ethtool_stats,
	.get_strings = xenvif_get_strings,
};

static struct net_device_ops xenvif_netdev_ops = {
	.ndo_start_xmit	= xenvif_start_xmit,
	.ndo_get_stats	= xenvif_get_stats,
	.ndo_open	= xenvif_open,
	.ndo_stop	= xenvif_close,
	.ndo_change_mtu	= xenvif_change_mtu,
};

struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
			    unsigned int handle)
{
	int err;
	struct net_device *dev;
	struct xenvif *vif;
	char name[IFNAMSIZ] = {};

	snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
	dev = alloc_netdev(sizeof(struct xenvif), name, ether_setup);
	if (dev == NULL) {
		pr_warn("Could not allocate netdev\n");
		return ERR_PTR(-ENOMEM);
	}

	SET_NETDEV_DEV(dev, parent);

	vif = netdev_priv(dev);
	vif->domid  = domid;
	vif->handle = handle;
	vif->netbk  = NULL;
	vif->can_sg = 1;
	vif->csum = 1;
	atomic_set(&vif->refcnt, 1);
	init_waitqueue_head(&vif->waiting_to_free);
	vif->dev = dev;
	INIT_LIST_HEAD(&vif->schedule_list);
	INIT_LIST_HEAD(&vif->notify_list);

	vif->credit_bytes = vif->remaining_credit = ~0UL;
	vif->credit_usec  = 0UL;
	init_timer(&vif->credit_timeout);
	/* Initialize 'expires' now: it's used to track the credit window. */
	vif->credit_timeout.expires = jiffies;

	dev->netdev_ops	= &xenvif_netdev_ops;
	xenvif_set_features(vif);
	SET_ETHTOOL_OPS(dev, &xenvif_ethtool_ops);

	dev->tx_queue_len = XENVIF_QUEUE_LENGTH;

	/*
	 * Initialise a dummy MAC address. We choose the numerically
	 * largest non-broadcast address to prevent the address getting
	 * stolen by an Ethernet bridge for STP purposes.
	 * (FE:FF:FF:FF:FF:FF)
	 */
	memset(dev->dev_addr, 0xFF, ETH_ALEN);
	dev->dev_addr[0] &= ~0x01;

	netif_carrier_off(dev);

	err = register_netdev(dev);
	if (err) {
		netdev_warn(dev, "Could not register device: err=%d\n", err);
		free_netdev(dev);
		return ERR_PTR(err);
	}

	netdev_dbg(dev, "Successfully created xenvif\n");
	return vif;
}

int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
		   unsigned long rx_ring_ref, unsigned int evtchn)
{
	int err = -ENOMEM;

	/* Already connected through? */
	if (vif->irq)
		return 0;

	xenvif_set_features(vif);

	err = xen_netbk_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref);
	if (err < 0)
		goto err;

	err = bind_interdomain_evtchn_to_irqhandler(
		vif->domid, evtchn, xenvif_interrupt, 0,
		vif->dev->name, vif);
	if (err < 0)
		goto err_unmap;
	vif->irq = err;
	disable_irq(vif->irq);

	xenvif_get(vif);

	rtnl_lock();
	netif_carrier_on(vif->dev);
	if (netif_running(vif->dev))
		xenvif_up(vif);
	rtnl_unlock();

	return 0;
err_unmap:
	xen_netbk_unmap_frontend_rings(vif);
err:
	return err;
}

void xenvif_disconnect(struct xenvif *vif)
{
	struct net_device *dev = vif->dev;
	if (netif_carrier_ok(dev)) {
		rtnl_lock();
		netif_carrier_off(dev); /* discard queued packets */
		if (netif_running(dev))
			xenvif_down(vif);
		rtnl_unlock();
		xenvif_put(vif);
	}

	atomic_dec(&vif->refcnt);
	wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0);

	del_timer_sync(&vif->credit_timeout);

	if (vif->irq)
		unbind_from_irqhandler(vif->irq, vif);

	unregister_netdev(vif->dev);

	xen_netbk_unmap_frontend_rings(vif);

	free_netdev(vif->dev);
}
Commit	Line	Data
f942dc25 IC	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/ethtool.h>
	34	#include <linux/rtnetlink.h>
	35	#include <linux/if_vlan.h>
	36
	37	#include <xen/events.h>
	38	#include <asm/xen/hypercall.h>
	39
	40	#define XENVIF_QUEUE_LENGTH 32
	41
	42	void xenvif_get(struct xenvif *vif)
	43	{
	44	atomic_inc(&vif->refcnt);
	45	}
	46
	47	void xenvif_put(struct xenvif *vif)
	48	{
	49	if (atomic_dec_and_test(&vif->refcnt))
	50	wake_up(&vif->waiting_to_free);
	51	}
	52
	53	int xenvif_schedulable(struct xenvif *vif)
	54	{
	55	return netif_running(vif->dev) && netif_carrier_ok(vif->dev);
	56	}
	57
	58	static int xenvif_rx_schedulable(struct xenvif *vif)
	59	{
	60	return xenvif_schedulable(vif) && !xen_netbk_rx_ring_full(vif);
	61	}
	62
	63	static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
	64	{
65	struct xenvif *vif = dev_id;
66
67	if (vif->netbk == NULL)
68	return IRQ_NONE;
69
70	xen_netbk_schedule_xenvif(vif);
71
72	if (xenvif_rx_schedulable(vif))
73	netif_wake_queue(vif->dev);
74
75	return IRQ_HANDLED;
76	}
77
78	static int xenvif_start_xmit(struct sk_buff skb, struct net_device dev)
79	{
80	struct xenvif *vif = netdev_priv(dev);
81
82	BUG_ON(skb->dev != dev);
83
84	if (vif->netbk == NULL)
85	goto drop;
86
87	/* Drop the packet if the target domain has no receive buffers. */
88	if (!xenvif_rx_schedulable(vif))
89	goto drop;
90
91	/* Reserve ring slots for the worst-case number of fragments. */
92	vif->rx_req_cons_peek += xen_netbk_count_skb_slots(vif, skb);
93	xenvif_get(vif);
94
95	if (vif->can_queue && xen_netbk_must_stop_queue(vif))
96	netif_stop_queue(dev);
97
98	xen_netbk_queue_tx_skb(vif, skb);
99
100	return NETDEV_TX_OK;
101
102	drop:
103	vif->dev->stats.tx_dropped++;
104	dev_kfree_skb(skb);
105	return NETDEV_TX_OK;
106	}
107
108	void xenvif_receive_skb(struct xenvif vif, struct sk_buff skb)
109	{
110	netif_rx_ni(skb);
111	}
112
113	void xenvif_notify_tx_completion(struct xenvif *vif)
114	{
115	if (netif_queue_stopped(vif->dev) && xenvif_rx_schedulable(vif))
116	netif_wake_queue(vif->dev);
117	}
118
119	static struct net_device_stats xenvif_get_stats(struct net_device dev)
120	{
121	struct xenvif *vif = netdev_priv(dev);
122	return &vif->dev->stats;
123	}
124
125	static void xenvif_up(struct xenvif *vif)
126	{
127	xen_netbk_add_xenvif(vif);
128	enable_irq(vif->irq);
129	xen_netbk_check_rx_xenvif(vif);
130	}
131
132	static void xenvif_down(struct xenvif *vif)
133	{
134	disable_irq(vif->irq);
135	xen_netbk_deschedule_xenvif(vif);
136	xen_netbk_remove_xenvif(vif);
137	}
138
139	static int xenvif_open(struct net_device *dev)
140	{
141	struct xenvif *vif = netdev_priv(dev);
142	if (netif_carrier_ok(dev))
143	xenvif_up(vif);
144	netif_start_queue(dev);
145	return 0;
146	}
147
148	static int xenvif_close(struct net_device *dev)
149	{
150	struct xenvif *vif = netdev_priv(dev);
151	if (netif_carrier_ok(dev))
152	xenvif_down(vif);
153	netif_stop_queue(dev);
154	return 0;
155	}
156
157	static int xenvif_change_mtu(struct net_device *dev, int mtu)
158	{
159	struct xenvif *vif = netdev_priv(dev);
160	int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN;
161
162	if (mtu > max)
163	return -EINVAL;
164	dev->mtu = mtu;
165	return 0;
166	}
167
168	static void xenvif_set_features(struct xenvif *vif)
169	{
170	struct net_device *dev = vif->dev;
171	u32 features = dev->features;
172
173	if (vif->can_sg)
174	features \|= NETIF_F_SG;
175	if (vif->gso \|\| vif->gso_prefix)
176	features \|= NETIF_F_TSO;
177	if (vif->csum)
178	features \|= NETIF_F_IP_CSUM;
179
180	features &= ~(vif->features_disabled);
181
182	if (!(features & NETIF_F_SG) && dev->mtu > ETH_DATA_LEN)
183	dev->mtu = ETH_DATA_LEN;
184
185	dev->features = features;
186	}
187
188	static int xenvif_set_tx_csum(struct net_device *dev, u32 data)
189	{
190	struct xenvif *vif = netdev_priv(dev);
191	if (data) {
192	if (!vif->csum)
193	return -EOPNOTSUPP;
194	vif->features_disabled &= ~NETIF_F_IP_CSUM;
195	} else {
196	vif->features_disabled \|= NETIF_F_IP_CSUM;
197	}
198
199	xenvif_set_features(vif);
200	return 0;
201	}
202
203	static int xenvif_set_sg(struct net_device *dev, u32 data)
204	{
205	struct xenvif *vif = netdev_priv(dev);
206	if (data) {
207	if (!vif->can_sg)
208	return -EOPNOTSUPP;
209	vif->features_disabled &= ~NETIF_F_SG;
210	} else {
211	vif->features_disabled \|= NETIF_F_SG;
212	}
213
214	xenvif_set_features(vif);
215	return 0;
216	}
217
218	static int xenvif_set_tso(struct net_device *dev, u32 data)
219	{
220	struct xenvif *vif = netdev_priv(dev);
221	if (data) {
222	if (!vif->gso && !vif->gso_prefix)
223	return -EOPNOTSUPP;
224	vif->features_disabled &= ~NETIF_F_TSO;
225	} else {
226	vif->features_disabled \|= NETIF_F_TSO;
227	}
228
229	xenvif_set_features(vif);
230	return 0;
231	}
232
233	static const struct xenvif_stat {
234	char name[ETH_GSTRING_LEN];
235	u16 offset;
236	} xenvif_stats[] = {
237	{
238	"rx_gso_checksum_fixup",
239	offsetof(struct xenvif, rx_gso_checksum_fixup)
240	},
241	};
242
243	static int xenvif_get_sset_count(struct net_device *dev, int string_set)
244	{
245	switch (string_set) {
246	case ETH_SS_STATS:
247	return ARRAY_SIZE(xenvif_stats);
248	default:
249	return -EINVAL;
250	}
251	}
252
253	static void xenvif_get_ethtool_stats(struct net_device *dev,
254	struct ethtool_stats stats, u64 data)
255	{
256	void *vif = netdev_priv(dev);
257	int i;
258
259	for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
260	data[i] = (unsigned long )(vif + xenvif_stats[i].offset);
261	}
262
263	static void xenvif_get_strings(struct net_device dev, u32 stringset, u8 data)
264	{
265	int i;
266
267	switch (stringset) {
268	case ETH_SS_STATS:
269	for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
270	memcpy(data + i * ETH_GSTRING_LEN,
271	xenvif_stats[i].name, ETH_GSTRING_LEN);
272	break;
273	}
274	}
275
276	static struct ethtool_ops xenvif_ethtool_ops = {
277	.get_tx_csum = ethtool_op_get_tx_csum,
278	.set_tx_csum = xenvif_set_tx_csum,
279	.get_sg = ethtool_op_get_sg,
280	.set_sg = xenvif_set_sg,
281	.get_tso = ethtool_op_get_tso,
282	.set_tso = xenvif_set_tso,
283	.get_link = ethtool_op_get_link,
284
285	.get_sset_count = xenvif_get_sset_count,
286	.get_ethtool_stats = xenvif_get_ethtool_stats,
287	.get_strings = xenvif_get_strings,
288	};
289
290	static struct net_device_ops xenvif_netdev_ops = {
291	.ndo_start_xmit = xenvif_start_xmit,
292	.ndo_get_stats = xenvif_get_stats,
293	.ndo_open = xenvif_open,
294	.ndo_stop = xenvif_close,
295	.ndo_change_mtu = xenvif_change_mtu,
296	};
297
298	struct xenvif xenvif_alloc(struct device parent, domid_t domid,
299	unsigned int handle)
300	{
301	int err;
302	struct net_device *dev;
303	struct xenvif *vif;
304	char name[IFNAMSIZ] = {};
305
306	snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
307	dev = alloc_netdev(sizeof(struct xenvif), name, ether_setup);
308	if (dev == NULL) {
309	pr_warn("Could not allocate netdev\n");
310	return ERR_PTR(-ENOMEM);
311	}
312
313	SET_NETDEV_DEV(dev, parent);
314
315	vif = netdev_priv(dev);
316	vif->domid = domid;
317	vif->handle = handle;
318	vif->netbk = NULL;
319	vif->can_sg = 1;
320	vif->csum = 1;
321	atomic_set(&vif->refcnt, 1);
322	init_waitqueue_head(&vif->waiting_to_free);
323	vif->dev = dev;
324	INIT_LIST_HEAD(&vif->schedule_list);
325	INIT_LIST_HEAD(&vif->notify_list);
326
327	vif->credit_bytes = vif->remaining_credit = ~0UL;
328	vif->credit_usec = 0UL;
329	init_timer(&vif->credit_timeout);
330	/* Initialize 'expires' now: it's used to track the credit window. */
331	vif->credit_timeout.expires = jiffies;
332
333	dev->netdev_ops = &xenvif_netdev_ops;
334	xenvif_set_features(vif);
335	SET_ETHTOOL_OPS(dev, &xenvif_ethtool_ops);
336
337	dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
338
339	/*
340	* Initialise a dummy MAC address. We choose the numerically
341	* largest non-broadcast address to prevent the address getting
342	* stolen by an Ethernet bridge for STP purposes.
343	* (FE:FF:FF:FF:FF:FF)
344	*/
345	memset(dev->dev_addr, 0xFF, ETH_ALEN);
346	dev->dev_addr[0] &= ~0x01;
347
348	netif_carrier_off(dev);
349
350	err = register_netdev(dev);
351	if (err) {
352	netdev_warn(dev, "Could not register device: err=%d\n", err);
353	free_netdev(dev);
354	return ERR_PTR(err);
355	}
356
357	netdev_dbg(dev, "Successfully created xenvif\n");
358	return vif;
359	}
360
361	int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
362	unsigned long rx_ring_ref, unsigned int evtchn)
363	{
364	int err = -ENOMEM;
365
366	/* Already connected through? */
367	if (vif->irq)
368	return 0;
369
370	xenvif_set_features(vif);
371
372	err = xen_netbk_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref);
373	if (err < 0)
374	goto err;
375
376	err = bind_interdomain_evtchn_to_irqhandler(
377	vif->domid, evtchn, xenvif_interrupt, 0,
378	vif->dev->name, vif);
379	if (err < 0)
380	goto err_unmap;
381	vif->irq = err;
382	disable_irq(vif->irq);
383
384	xenvif_get(vif);
385
386	rtnl_lock();
387	netif_carrier_on(vif->dev);
388	if (netif_running(vif->dev))
389	xenvif_up(vif);
390	rtnl_unlock();
391
392	return 0;
393	err_unmap:
394	xen_netbk_unmap_frontend_rings(vif);
395	err:
396	return err;
397	}
398
399	void xenvif_disconnect(struct xenvif *vif)
400	{
401	struct net_device *dev = vif->dev;
402	if (netif_carrier_ok(dev)) {
403	rtnl_lock();
404	netif_carrier_off(dev); /* discard queued packets */
405	if (netif_running(dev))
406	xenvif_down(vif);
407	rtnl_unlock();
408	xenvif_put(vif);
409	}
410
411	atomic_dec(&vif->refcnt);
412	wait_event(vif->waiting_to_free, atomic_read(&vif->refcnt) == 0);
413
414	del_timer_sync(&vif->credit_timeout);
415
416	if (vif->irq)
417	unbind_from_irqhandler(vif->irq, vif);
418
419	unregister_netdev(vif->dev);
420
421	xen_netbk_unmap_frontend_rings(vif);
422
423	free_netdev(vif->dev);
424	}