xen-netback: clear vif->task on disconnect
[deliverable/linux.git] / drivers / net / xen-netback / interface.c
CommitLineData
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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
b3f980bd 33#include <linux/kthread.h>
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34#include <linux/ethtool.h>
35#include <linux/rtnetlink.h>
36#include <linux/if_vlan.h>
37
38#include <xen/events.h>
39#include <asm/xen/hypercall.h>
40
41#define XENVIF_QUEUE_LENGTH 32
b3f980bd 42#define XENVIF_NAPI_WEIGHT 64
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43
44int xenvif_schedulable(struct xenvif *vif)
45{
46 return netif_running(vif->dev) && netif_carrier_ok(vif->dev);
47}
48
49static int xenvif_rx_schedulable(struct xenvif *vif)
50{
7376419a 51 return xenvif_schedulable(vif) && !xenvif_rx_ring_full(vif);
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IC
52}
53
e1f00a69 54static irqreturn_t xenvif_tx_interrupt(int irq, void *dev_id)
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IC
55{
56 struct xenvif *vif = dev_id;
57
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WL
58 if (RING_HAS_UNCONSUMED_REQUESTS(&vif->tx))
59 napi_schedule(&vif->napi);
f942dc25 60
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WL
61 return IRQ_HANDLED;
62}
63
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WL
64static int xenvif_poll(struct napi_struct *napi, int budget)
65{
66 struct xenvif *vif = container_of(napi, struct xenvif, napi);
67 int work_done;
68
7376419a 69 work_done = xenvif_tx_action(vif, budget);
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WL
70
71 if (work_done < budget) {
72 int more_to_do = 0;
73 unsigned long flags;
74
75 /* It is necessary to disable IRQ before calling
76 * RING_HAS_UNCONSUMED_REQUESTS. Otherwise we might
77 * lose event from the frontend.
78 *
79 * Consider:
80 * RING_HAS_UNCONSUMED_REQUESTS
81 * <frontend generates event to trigger napi_schedule>
82 * __napi_complete
83 *
84 * This handler is still in scheduled state so the
85 * event has no effect at all. After __napi_complete
86 * this handler is descheduled and cannot get
87 * scheduled again. We lose event in this case and the ring
88 * will be completely stalled.
89 */
90
91 local_irq_save(flags);
92
93 RING_FINAL_CHECK_FOR_REQUESTS(&vif->tx, more_to_do);
94 if (!more_to_do)
95 __napi_complete(napi);
96
97 local_irq_restore(flags);
98 }
99
100 return work_done;
101}
102
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103static irqreturn_t xenvif_rx_interrupt(int irq, void *dev_id)
104{
105 struct xenvif *vif = dev_id;
106
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107 if (xenvif_rx_schedulable(vif))
108 netif_wake_queue(vif->dev);
109
110 return IRQ_HANDLED;
111}
112
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113static irqreturn_t xenvif_interrupt(int irq, void *dev_id)
114{
115 xenvif_tx_interrupt(irq, dev_id);
116 xenvif_rx_interrupt(irq, dev_id);
117
118 return IRQ_HANDLED;
119}
120
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121static int xenvif_start_xmit(struct sk_buff *skb, struct net_device *dev)
122{
123 struct xenvif *vif = netdev_priv(dev);
124
125 BUG_ON(skb->dev != dev);
126
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127 /* Drop the packet if vif is not ready */
128 if (vif->task == NULL)
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129 goto drop;
130
131 /* Drop the packet if the target domain has no receive buffers. */
132 if (!xenvif_rx_schedulable(vif))
133 goto drop;
134
135 /* Reserve ring slots for the worst-case number of fragments. */
7376419a 136 vif->rx_req_cons_peek += xenvif_count_skb_slots(vif, skb);
f942dc25 137
7376419a 138 if (vif->can_queue && xenvif_must_stop_queue(vif))
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139 netif_stop_queue(dev);
140
7376419a 141 xenvif_queue_tx_skb(vif, skb);
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142
143 return NETDEV_TX_OK;
144
145 drop:
146 vif->dev->stats.tx_dropped++;
147 dev_kfree_skb(skb);
148 return NETDEV_TX_OK;
149}
150
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151void xenvif_notify_tx_completion(struct xenvif *vif)
152{
153 if (netif_queue_stopped(vif->dev) && xenvif_rx_schedulable(vif))
154 netif_wake_queue(vif->dev);
155}
156
157static struct net_device_stats *xenvif_get_stats(struct net_device *dev)
158{
159 struct xenvif *vif = netdev_priv(dev);
160 return &vif->dev->stats;
161}
162
163static void xenvif_up(struct xenvif *vif)
164{
b3f980bd 165 napi_enable(&vif->napi);
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166 enable_irq(vif->tx_irq);
167 if (vif->tx_irq != vif->rx_irq)
168 enable_irq(vif->rx_irq);
7376419a 169 xenvif_check_rx_xenvif(vif);
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170}
171
172static void xenvif_down(struct xenvif *vif)
173{
b3f980bd 174 napi_disable(&vif->napi);
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175 disable_irq(vif->tx_irq);
176 if (vif->tx_irq != vif->rx_irq)
177 disable_irq(vif->rx_irq);
3e55f8b3 178 del_timer_sync(&vif->credit_timeout);
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179}
180
181static int xenvif_open(struct net_device *dev)
182{
183 struct xenvif *vif = netdev_priv(dev);
184 if (netif_carrier_ok(dev))
185 xenvif_up(vif);
186 netif_start_queue(dev);
187 return 0;
188}
189
190static int xenvif_close(struct net_device *dev)
191{
192 struct xenvif *vif = netdev_priv(dev);
193 if (netif_carrier_ok(dev))
194 xenvif_down(vif);
195 netif_stop_queue(dev);
196 return 0;
197}
198
199static int xenvif_change_mtu(struct net_device *dev, int mtu)
200{
201 struct xenvif *vif = netdev_priv(dev);
202 int max = vif->can_sg ? 65535 - VLAN_ETH_HLEN : ETH_DATA_LEN;
203
204 if (mtu > max)
205 return -EINVAL;
206 dev->mtu = mtu;
207 return 0;
208}
209
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MM
210static netdev_features_t xenvif_fix_features(struct net_device *dev,
211 netdev_features_t features)
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212{
213 struct xenvif *vif = netdev_priv(dev);
f942dc25 214
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215 if (!vif->can_sg)
216 features &= ~NETIF_F_SG;
82cada22 217 if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV4))
47103041 218 features &= ~NETIF_F_TSO;
82cada22
PD
219 if (~(vif->gso_mask | vif->gso_prefix_mask) & GSO_BIT(TCPV6))
220 features &= ~NETIF_F_TSO6;
146c8a77 221 if (!vif->ip_csum)
47103041 222 features &= ~NETIF_F_IP_CSUM;
146c8a77
PD
223 if (!vif->ipv6_csum)
224 features &= ~NETIF_F_IPV6_CSUM;
f942dc25 225
47103041 226 return features;
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IC
227}
228
229static const struct xenvif_stat {
230 char name[ETH_GSTRING_LEN];
231 u16 offset;
232} xenvif_stats[] = {
233 {
234 "rx_gso_checksum_fixup",
235 offsetof(struct xenvif, rx_gso_checksum_fixup)
236 },
237};
238
239static int xenvif_get_sset_count(struct net_device *dev, int string_set)
240{
241 switch (string_set) {
242 case ETH_SS_STATS:
243 return ARRAY_SIZE(xenvif_stats);
244 default:
245 return -EINVAL;
246 }
247}
248
249static void xenvif_get_ethtool_stats(struct net_device *dev,
250 struct ethtool_stats *stats, u64 * data)
251{
252 void *vif = netdev_priv(dev);
253 int i;
254
255 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
256 data[i] = *(unsigned long *)(vif + xenvif_stats[i].offset);
257}
258
259static void xenvif_get_strings(struct net_device *dev, u32 stringset, u8 * data)
260{
261 int i;
262
263 switch (stringset) {
264 case ETH_SS_STATS:
265 for (i = 0; i < ARRAY_SIZE(xenvif_stats); i++)
266 memcpy(data + i * ETH_GSTRING_LEN,
267 xenvif_stats[i].name, ETH_GSTRING_LEN);
268 break;
269 }
270}
271
813abbba 272static const struct ethtool_ops xenvif_ethtool_ops = {
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273 .get_link = ethtool_op_get_link,
274
275 .get_sset_count = xenvif_get_sset_count,
276 .get_ethtool_stats = xenvif_get_ethtool_stats,
277 .get_strings = xenvif_get_strings,
278};
279
813abbba 280static const struct net_device_ops xenvif_netdev_ops = {
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281 .ndo_start_xmit = xenvif_start_xmit,
282 .ndo_get_stats = xenvif_get_stats,
283 .ndo_open = xenvif_open,
284 .ndo_stop = xenvif_close,
285 .ndo_change_mtu = xenvif_change_mtu,
47103041 286 .ndo_fix_features = xenvif_fix_features,
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MW
287 .ndo_set_mac_address = eth_mac_addr,
288 .ndo_validate_addr = eth_validate_addr,
f942dc25
IC
289};
290
291struct xenvif *xenvif_alloc(struct device *parent, domid_t domid,
292 unsigned int handle)
293{
294 int err;
295 struct net_device *dev;
296 struct xenvif *vif;
297 char name[IFNAMSIZ] = {};
b3f980bd 298 int i;
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299
300 snprintf(name, IFNAMSIZ - 1, "vif%u.%u", domid, handle);
301 dev = alloc_netdev(sizeof(struct xenvif), name, ether_setup);
302 if (dev == NULL) {
b3f980bd 303 pr_warn("Could not allocate netdev for %s\n", name);
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IC
304 return ERR_PTR(-ENOMEM);
305 }
306
307 SET_NETDEV_DEV(dev, parent);
308
309 vif = netdev_priv(dev);
310 vif->domid = domid;
311 vif->handle = handle;
f942dc25 312 vif->can_sg = 1;
146c8a77 313 vif->ip_csum = 1;
f942dc25 314 vif->dev = dev;
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315
316 vif->credit_bytes = vif->remaining_credit = ~0UL;
317 vif->credit_usec = 0UL;
318 init_timer(&vif->credit_timeout);
059dfa6a 319 vif->credit_window_start = get_jiffies_64();
f942dc25
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320
321 dev->netdev_ops = &xenvif_netdev_ops;
146c8a77
PD
322 dev->hw_features = NETIF_F_SG |
323 NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM |
82cada22 324 NETIF_F_TSO | NETIF_F_TSO6;
7365bcfa 325 dev->features = dev->hw_features | NETIF_F_RXCSUM;
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326 SET_ETHTOOL_OPS(dev, &xenvif_ethtool_ops);
327
328 dev->tx_queue_len = XENVIF_QUEUE_LENGTH;
329
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WL
330 skb_queue_head_init(&vif->rx_queue);
331 skb_queue_head_init(&vif->tx_queue);
332
333 vif->pending_cons = 0;
334 vif->pending_prod = MAX_PENDING_REQS;
335 for (i = 0; i < MAX_PENDING_REQS; i++)
336 vif->pending_ring[i] = i;
337 for (i = 0; i < MAX_PENDING_REQS; i++)
338 vif->mmap_pages[i] = NULL;
339
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IC
340 /*
341 * Initialise a dummy MAC address. We choose the numerically
342 * largest non-broadcast address to prevent the address getting
343 * stolen by an Ethernet bridge for STP purposes.
344 * (FE:FF:FF:FF:FF:FF)
345 */
346 memset(dev->dev_addr, 0xFF, ETH_ALEN);
347 dev->dev_addr[0] &= ~0x01;
348
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WL
349 netif_napi_add(dev, &vif->napi, xenvif_poll, XENVIF_NAPI_WEIGHT);
350
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IC
351 netif_carrier_off(dev);
352
353 err = register_netdev(dev);
354 if (err) {
355 netdev_warn(dev, "Could not register device: err=%d\n", err);
356 free_netdev(dev);
357 return ERR_PTR(err);
358 }
359
360 netdev_dbg(dev, "Successfully created xenvif\n");
279f438e
PD
361
362 __module_get(THIS_MODULE);
363
f942dc25
IC
364 return vif;
365}
366
367int xenvif_connect(struct xenvif *vif, unsigned long tx_ring_ref,
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WL
368 unsigned long rx_ring_ref, unsigned int tx_evtchn,
369 unsigned int rx_evtchn)
f942dc25 370{
67fa3660 371 struct task_struct *task;
f942dc25
IC
372 int err = -ENOMEM;
373
67fa3660
PD
374 BUG_ON(vif->tx_irq);
375 BUG_ON(vif->task);
f942dc25 376
7376419a 377 err = xenvif_map_frontend_rings(vif, tx_ring_ref, rx_ring_ref);
f942dc25
IC
378 if (err < 0)
379 goto err;
380
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WL
381 if (tx_evtchn == rx_evtchn) {
382 /* feature-split-event-channels == 0 */
383 err = bind_interdomain_evtchn_to_irqhandler(
384 vif->domid, tx_evtchn, xenvif_interrupt, 0,
385 vif->dev->name, vif);
386 if (err < 0)
387 goto err_unmap;
388 vif->tx_irq = vif->rx_irq = err;
389 disable_irq(vif->tx_irq);
390 } else {
391 /* feature-split-event-channels == 1 */
392 snprintf(vif->tx_irq_name, sizeof(vif->tx_irq_name),
393 "%s-tx", vif->dev->name);
394 err = bind_interdomain_evtchn_to_irqhandler(
395 vif->domid, tx_evtchn, xenvif_tx_interrupt, 0,
396 vif->tx_irq_name, vif);
397 if (err < 0)
398 goto err_unmap;
399 vif->tx_irq = err;
400 disable_irq(vif->tx_irq);
401
402 snprintf(vif->rx_irq_name, sizeof(vif->rx_irq_name),
403 "%s-rx", vif->dev->name);
404 err = bind_interdomain_evtchn_to_irqhandler(
405 vif->domid, rx_evtchn, xenvif_rx_interrupt, 0,
406 vif->rx_irq_name, vif);
407 if (err < 0)
408 goto err_tx_unbind;
409 vif->rx_irq = err;
410 disable_irq(vif->rx_irq);
411 }
f942dc25 412
b3f980bd 413 init_waitqueue_head(&vif->wq);
67fa3660
PD
414 task = kthread_create(xenvif_kthread,
415 (void *)vif, "%s", vif->dev->name);
416 if (IS_ERR(task)) {
b3f980bd 417 pr_warn("Could not allocate kthread for %s\n", vif->dev->name);
67fa3660 418 err = PTR_ERR(task);
b3f980bd
WL
419 goto err_rx_unbind;
420 }
f942dc25 421
67fa3660
PD
422 vif->task = task;
423
f942dc25 424 rtnl_lock();
47103041
MM
425 if (!vif->can_sg && vif->dev->mtu > ETH_DATA_LEN)
426 dev_set_mtu(vif->dev, ETH_DATA_LEN);
427 netdev_update_features(vif->dev);
428 netif_carrier_on(vif->dev);
d0e5d832
DV
429 if (netif_running(vif->dev))
430 xenvif_up(vif);
f942dc25
IC
431 rtnl_unlock();
432
b3f980bd
WL
433 wake_up_process(vif->task);
434
f942dc25 435 return 0;
b3f980bd
WL
436
437err_rx_unbind:
438 unbind_from_irqhandler(vif->rx_irq, vif);
439 vif->rx_irq = 0;
e1f00a69
WL
440err_tx_unbind:
441 unbind_from_irqhandler(vif->tx_irq, vif);
442 vif->tx_irq = 0;
f942dc25 443err_unmap:
7376419a 444 xenvif_unmap_frontend_rings(vif);
f942dc25 445err:
b103f358 446 module_put(THIS_MODULE);
f942dc25
IC
447 return err;
448}
449
48856286 450void xenvif_carrier_off(struct xenvif *vif)
f942dc25
IC
451{
452 struct net_device *dev = vif->dev;
48856286
IC
453
454 rtnl_lock();
455 netif_carrier_off(dev); /* discard queued packets */
456 if (netif_running(dev))
457 xenvif_down(vif);
458 rtnl_unlock();
48856286
IC
459}
460
461void xenvif_disconnect(struct xenvif *vif)
462{
463 if (netif_carrier_ok(vif->dev))
464 xenvif_carrier_off(vif);
f942dc25 465
67fa3660 466 if (vif->task) {
db739ef3 467 kthread_stop(vif->task);
67fa3660
PD
468 vif->task = NULL;
469 }
db739ef3 470
e1f00a69
WL
471 if (vif->tx_irq) {
472 if (vif->tx_irq == vif->rx_irq)
473 unbind_from_irqhandler(vif->tx_irq, vif);
474 else {
475 unbind_from_irqhandler(vif->tx_irq, vif);
476 unbind_from_irqhandler(vif->rx_irq, vif);
477 }
279f438e 478 vif->tx_irq = 0;
b103f358 479 }
f942dc25 480
279f438e
PD
481 xenvif_unmap_frontend_rings(vif);
482}
483
484void xenvif_free(struct xenvif *vif)
485{
b3f980bd
WL
486 netif_napi_del(&vif->napi);
487
f942dc25
IC
488 unregister_netdev(vif->dev);
489
f942dc25 490 free_netdev(vif->dev);
b103f358 491
279f438e 492 module_put(THIS_MODULE);
f942dc25 493}
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