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[mirror_ubuntu-artful-kernel.git] / drivers / net / xen-netback / xenbus.c
CommitLineData
f942dc25
IC
1/*
2 * Xenbus code for netif backend
3 *
4 * Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au>
5 * Copyright (C) 2005 XenSource Ltd
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
adf8d3ff 18 * along with this program; if not, see <http://www.gnu.org/licenses/>.
f942dc25
IC
19*/
20
21#include "common.h"
e9ce7cb6
WL
22#include <linux/vmalloc.h>
23#include <linux/rtnetlink.h>
f942dc25
IC
24
25struct backend_info {
26 struct xenbus_device *dev;
27 struct xenvif *vif;
ea732dff
PD
28
29 /* This is the state that will be reflected in xenstore when any
30 * active hotplug script completes.
31 */
32 enum xenbus_state state;
33
f942dc25
IC
34 enum xenbus_state frontend_state;
35 struct xenbus_watch hotplug_status_watch;
17938a69 36 u8 have_hotplug_status_watch:1;
31a41898
IC
37
38 const char *hotplug_script;
f942dc25
IC
39};
40
4e15ee2c
PD
41static int connect_data_rings(struct backend_info *be,
42 struct xenvif_queue *queue);
e9ce7cb6
WL
43static void connect(struct backend_info *be);
44static int read_xenbus_vif_flags(struct backend_info *be);
2dd34339 45static int backend_create_xenvif(struct backend_info *be);
f942dc25 46static void unregister_hotplug_status_watch(struct backend_info *be);
edafc132 47static void xen_unregister_watchers(struct xenvif *vif);
dc62ccac
DV
48static void set_backend_state(struct backend_info *be,
49 enum xenbus_state state);
f942dc25 50
f51de243
ZK
51#ifdef CONFIG_DEBUG_FS
52struct dentry *xen_netback_dbg_root = NULL;
53
54static int xenvif_read_io_ring(struct seq_file *m, void *v)
55{
56 struct xenvif_queue *queue = m->private;
57 struct xen_netif_tx_back_ring *tx_ring = &queue->tx;
58 struct xen_netif_rx_back_ring *rx_ring = &queue->rx;
f48da8b1 59 struct netdev_queue *dev_queue;
f51de243
ZK
60
61 if (tx_ring->sring) {
62 struct xen_netif_tx_sring *sring = tx_ring->sring;
63
64 seq_printf(m, "Queue %d\nTX: nr_ents %u\n", queue->id,
65 tx_ring->nr_ents);
66 seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
67 sring->req_prod,
68 sring->req_prod - sring->rsp_prod,
69 tx_ring->req_cons,
70 tx_ring->req_cons - sring->rsp_prod,
71 sring->req_event,
72 sring->req_event - sring->rsp_prod);
73 seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n",
74 sring->rsp_prod,
75 tx_ring->rsp_prod_pvt,
76 tx_ring->rsp_prod_pvt - sring->rsp_prod,
77 sring->rsp_event,
78 sring->rsp_event - sring->rsp_prod);
79 seq_printf(m, "pending prod %u pending cons %u nr_pending_reqs %u\n",
80 queue->pending_prod,
81 queue->pending_cons,
82 nr_pending_reqs(queue));
83 seq_printf(m, "dealloc prod %u dealloc cons %u dealloc_queue %u\n\n",
84 queue->dealloc_prod,
85 queue->dealloc_cons,
86 queue->dealloc_prod - queue->dealloc_cons);
87 }
88
89 if (rx_ring->sring) {
90 struct xen_netif_rx_sring *sring = rx_ring->sring;
91
92 seq_printf(m, "RX: nr_ents %u\n", rx_ring->nr_ents);
93 seq_printf(m, "req prod %u (%d) cons %u (%d) event %u (%d)\n",
94 sring->req_prod,
95 sring->req_prod - sring->rsp_prod,
96 rx_ring->req_cons,
97 rx_ring->req_cons - sring->rsp_prod,
98 sring->req_event,
99 sring->req_event - sring->rsp_prod);
100 seq_printf(m, "rsp prod %u (base) pvt %u (%d) event %u (%d)\n\n",
101 sring->rsp_prod,
102 rx_ring->rsp_prod_pvt,
103 rx_ring->rsp_prod_pvt - sring->rsp_prod,
104 sring->rsp_event,
105 sring->rsp_event - sring->rsp_prod);
106 }
107
108 seq_printf(m, "NAPI state: %lx NAPI weight: %d TX queue len %u\n"
109 "Credit timer_pending: %d, credit: %lu, usec: %lu\n"
110 "remaining: %lu, expires: %lu, now: %lu\n",
111 queue->napi.state, queue->napi.weight,
112 skb_queue_len(&queue->tx_queue),
113 timer_pending(&queue->credit_timeout),
114 queue->credit_bytes,
115 queue->credit_usec,
116 queue->remaining_credit,
117 queue->credit_timeout.expires,
118 jiffies);
119
f48da8b1
DV
120 dev_queue = netdev_get_tx_queue(queue->vif->dev, queue->id);
121
122 seq_printf(m, "\nRx internal queue: len %u max %u pkts %u %s\n",
123 queue->rx_queue_len, queue->rx_queue_max,
124 skb_queue_len(&queue->rx_queue),
125 netif_tx_queue_stopped(dev_queue) ? "stopped" : "running");
126
f51de243
ZK
127 return 0;
128}
129
130#define XENVIF_KICK_STR "kick"
5c807005 131#define BUFFER_SIZE 32
f51de243
ZK
132
133static ssize_t
134xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count,
135 loff_t *ppos)
136{
137 struct xenvif_queue *queue =
138 ((struct seq_file *)filp->private_data)->private;
139 int len;
5c807005 140 char write[BUFFER_SIZE];
f51de243
ZK
141
142 /* don't allow partial writes and check the length */
143 if (*ppos != 0)
144 return 0;
5c807005 145 if (count >= sizeof(write))
f51de243
ZK
146 return -ENOSPC;
147
148 len = simple_write_to_buffer(write,
5c807005 149 sizeof(write) - 1,
f51de243
ZK
150 ppos,
151 buf,
152 count);
153 if (len < 0)
154 return len;
155
5c807005
WL
156 write[len] = '\0';
157
f51de243
ZK
158 if (!strncmp(write, XENVIF_KICK_STR, sizeof(XENVIF_KICK_STR) - 1))
159 xenvif_interrupt(0, (void *)queue);
160 else {
161 pr_warn("Unknown command to io_ring_q%d. Available: kick\n",
162 queue->id);
163 count = -EINVAL;
164 }
165 return count;
166}
167
a9339b8e 168static int xenvif_io_ring_open(struct inode *inode, struct file *filp)
f51de243
ZK
169{
170 int ret;
171 void *queue = NULL;
172
173 if (inode->i_private)
174 queue = inode->i_private;
175 ret = single_open(filp, xenvif_read_io_ring, queue);
176 filp->f_mode |= FMODE_PWRITE;
177 return ret;
178}
179
180static const struct file_operations xenvif_dbg_io_ring_ops_fops = {
181 .owner = THIS_MODULE,
a9339b8e 182 .open = xenvif_io_ring_open,
f51de243
ZK
183 .read = seq_read,
184 .llseek = seq_lseek,
185 .release = single_release,
186 .write = xenvif_write_io_ring,
187};
188
a9339b8e
PD
189static int xenvif_read_ctrl(struct seq_file *m, void *v)
190{
191 struct xenvif *vif = m->private;
192
193 xenvif_dump_hash_info(vif, m);
194
195 return 0;
196}
197
198static int xenvif_ctrl_open(struct inode *inode, struct file *filp)
199{
200 return single_open(filp, xenvif_read_ctrl, inode->i_private);
201}
202
203static const struct file_operations xenvif_dbg_ctrl_ops_fops = {
204 .owner = THIS_MODULE,
205 .open = xenvif_ctrl_open,
206 .read = seq_read,
207 .llseek = seq_lseek,
208 .release = single_release,
209};
210
628fa76b 211static void xenvif_debugfs_addif(struct xenvif *vif)
f51de243
ZK
212{
213 struct dentry *pfile;
f51de243
ZK
214 int i;
215
216 if (IS_ERR_OR_NULL(xen_netback_dbg_root))
217 return;
218
219 vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name,
220 xen_netback_dbg_root);
221 if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) {
222 for (i = 0; i < vif->num_queues; ++i) {
223 char filename[sizeof("io_ring_q") + 4];
224
225 snprintf(filename, sizeof(filename), "io_ring_q%d", i);
226 pfile = debugfs_create_file(filename,
227 S_IRUSR | S_IWUSR,
228 vif->xenvif_dbg_root,
229 &vif->queues[i],
230 &xenvif_dbg_io_ring_ops_fops);
231 if (IS_ERR_OR_NULL(pfile))
232 pr_warn("Creation of io_ring file returned %ld!\n",
233 PTR_ERR(pfile));
234 }
a9339b8e
PD
235
236 if (vif->ctrl_irq) {
237 pfile = debugfs_create_file("ctrl",
238 S_IRUSR,
239 vif->xenvif_dbg_root,
240 vif,
241 &xenvif_dbg_ctrl_ops_fops);
242 if (IS_ERR_OR_NULL(pfile))
243 pr_warn("Creation of ctrl file returned %ld!\n",
244 PTR_ERR(pfile));
245 }
f51de243
ZK
246 } else
247 netdev_warn(vif->dev,
248 "Creation of vif debugfs dir returned %ld!\n",
249 PTR_ERR(vif->xenvif_dbg_root));
250}
251
252static void xenvif_debugfs_delif(struct xenvif *vif)
253{
254 if (IS_ERR_OR_NULL(xen_netback_dbg_root))
255 return;
256
257 if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root))
258 debugfs_remove_recursive(vif->xenvif_dbg_root);
259 vif->xenvif_dbg_root = NULL;
260}
261#endif /* CONFIG_DEBUG_FS */
262
f942dc25
IC
263static int netback_remove(struct xenbus_device *dev)
264{
265 struct backend_info *be = dev_get_drvdata(&dev->dev);
266
dc62ccac
DV
267 set_backend_state(be, XenbusStateClosed);
268
f942dc25
IC
269 unregister_hotplug_status_watch(be);
270 if (be->vif) {
271 kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
edafc132 272 xen_unregister_watchers(be->vif);
f942dc25 273 xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
279f438e 274 xenvif_free(be->vif);
f942dc25
IC
275 be->vif = NULL;
276 }
31a41898 277 kfree(be->hotplug_script);
f942dc25
IC
278 kfree(be);
279 dev_set_drvdata(&dev->dev, NULL);
280 return 0;
281}
282
283
284/**
285 * Entry point to this code when a new device is created. Allocate the basic
286 * structures and switch to InitWait.
287 */
288static int netback_probe(struct xenbus_device *dev,
289 const struct xenbus_device_id *id)
290{
291 const char *message;
292 struct xenbus_transaction xbt;
293 int err;
294 int sg;
31a41898 295 const char *script;
f942dc25
IC
296 struct backend_info *be = kzalloc(sizeof(struct backend_info),
297 GFP_KERNEL);
298 if (!be) {
299 xenbus_dev_fatal(dev, -ENOMEM,
300 "allocating backend structure");
301 return -ENOMEM;
302 }
303
304 be->dev = dev;
305 dev_set_drvdata(&dev->dev, be);
306
cce94483
FM
307 be->state = XenbusStateInitialising;
308 err = xenbus_switch_state(dev, XenbusStateInitialising);
309 if (err)
310 goto fail;
311
f942dc25
IC
312 sg = 1;
313
314 do {
315 err = xenbus_transaction_start(&xbt);
316 if (err) {
317 xenbus_dev_fatal(dev, err, "starting transaction");
318 goto fail;
319 }
320
321 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
322 if (err) {
323 message = "writing feature-sg";
324 goto abort_transaction;
325 }
326
327 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
328 "%d", sg);
329 if (err) {
330 message = "writing feature-gso-tcpv4";
331 goto abort_transaction;
332 }
333
a9468587
PD
334 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6",
335 "%d", sg);
336 if (err) {
337 message = "writing feature-gso-tcpv6";
338 goto abort_transaction;
339 }
340
2eba61d5
PD
341 /* We support partial checksum setup for IPv6 packets */
342 err = xenbus_printf(xbt, dev->nodename,
343 "feature-ipv6-csum-offload",
344 "%d", 1);
345 if (err) {
346 message = "writing feature-ipv6-csum-offload";
347 goto abort_transaction;
348 }
349
f942dc25
IC
350 /* We support rx-copy path. */
351 err = xenbus_printf(xbt, dev->nodename,
352 "feature-rx-copy", "%d", 1);
353 if (err) {
354 message = "writing feature-rx-copy";
355 goto abort_transaction;
356 }
357
358 /*
359 * We don't support rx-flip path (except old guests who don't
360 * grok this feature flag).
361 */
362 err = xenbus_printf(xbt, dev->nodename,
363 "feature-rx-flip", "%d", 0);
364 if (err) {
365 message = "writing feature-rx-flip";
366 goto abort_transaction;
367 }
368
22fae97d 369 /* We support dynamic multicast-control. */
210c34dc
PD
370 err = xenbus_printf(xbt, dev->nodename,
371 "feature-multicast-control", "%d", 1);
372 if (err) {
373 message = "writing feature-multicast-control";
374 goto abort_transaction;
375 }
376
22fae97d
PD
377 err = xenbus_printf(xbt, dev->nodename,
378 "feature-dynamic-multicast-control",
379 "%d", 1);
380 if (err) {
381 message = "writing feature-dynamic-multicast-control";
382 goto abort_transaction;
383 }
384
f942dc25
IC
385 err = xenbus_transaction_end(xbt, 0);
386 } while (err == -EAGAIN);
387
388 if (err) {
389 xenbus_dev_fatal(dev, err, "completing transaction");
390 goto fail;
391 }
392
e1f00a69
WL
393 /*
394 * Split event channels support, this is optional so it is not
395 * put inside the above loop.
396 */
397 err = xenbus_printf(XBT_NIL, dev->nodename,
398 "feature-split-event-channels",
399 "%u", separate_tx_rx_irq);
400 if (err)
8ef2c3bc 401 pr_debug("Error writing feature-split-event-channels\n");
e1f00a69 402
8d3d53b3
AB
403 /* Multi-queue support: This is an optional feature. */
404 err = xenbus_printf(XBT_NIL, dev->nodename,
405 "multi-queue-max-queues", "%u", xenvif_max_queues);
406 if (err)
407 pr_debug("Error writing multi-queue-max-queues\n");
408
4e15ee2c
PD
409 err = xenbus_printf(XBT_NIL, dev->nodename,
410 "feature-ctrl-ring",
411 "%u", true);
412 if (err)
413 pr_debug("Error writing feature-ctrl-ring\n");
414
31a41898
IC
415 script = xenbus_read(XBT_NIL, dev->nodename, "script", NULL);
416 if (IS_ERR(script)) {
417 err = PTR_ERR(script);
418 xenbus_dev_fatal(dev, err, "reading script");
419 goto fail;
420 }
421
422 be->hotplug_script = script;
423
ea732dff 424
f942dc25 425 /* This kicks hotplug scripts, so do it immediately. */
2dd34339
AK
426 err = backend_create_xenvif(be);
427 if (err)
428 goto fail;
f942dc25
IC
429
430 return 0;
431
432abort_transaction:
433 xenbus_transaction_end(xbt, 1);
434 xenbus_dev_fatal(dev, err, "%s", message);
435fail:
8ef2c3bc 436 pr_debug("failed\n");
f942dc25
IC
437 netback_remove(dev);
438 return err;
439}
440
441
442/*
443 * Handle the creation of the hotplug script environment. We add the script
444 * and vif variables to the environment, for the benefit of the vif-* hotplug
445 * scripts.
446 */
447static int netback_uevent(struct xenbus_device *xdev,
448 struct kobj_uevent_env *env)
449{
450 struct backend_info *be = dev_get_drvdata(&xdev->dev);
f942dc25 451
31a41898
IC
452 if (!be)
453 return 0;
454
455 if (add_uevent_var(env, "script=%s", be->hotplug_script))
456 return -ENOMEM;
457
458 if (!be->vif)
f942dc25
IC
459 return 0;
460
461 return add_uevent_var(env, "vif=%s", be->vif->dev->name);
462}
463
464
2dd34339 465static int backend_create_xenvif(struct backend_info *be)
f942dc25
IC
466{
467 int err;
468 long handle;
469 struct xenbus_device *dev = be->dev;
f15650b7 470 struct xenvif *vif;
f942dc25
IC
471
472 if (be->vif != NULL)
2dd34339 473 return 0;
f942dc25
IC
474
475 err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
476 if (err != 1) {
477 xenbus_dev_fatal(dev, err, "reading handle");
2dd34339 478 return (err < 0) ? err : -EINVAL;
f942dc25
IC
479 }
480
f15650b7
JB
481 vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
482 if (IS_ERR(vif)) {
483 err = PTR_ERR(vif);
f942dc25 484 xenbus_dev_fatal(dev, err, "creating interface");
2dd34339 485 return err;
f942dc25 486 }
f15650b7 487 be->vif = vif;
f942dc25
IC
488
489 kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
2dd34339 490 return 0;
f942dc25
IC
491}
492
ea732dff 493static void backend_disconnect(struct backend_info *be)
f942dc25 494{
d67ce7da
PD
495 struct xenvif *vif = be->vif;
496
497 if (vif) {
9a6cdf52 498 unsigned int queue_index;
a254d8f9 499 struct xenvif_queue *queues;
9a6cdf52 500
d67ce7da 501 xen_unregister_watchers(vif);
f51de243 502#ifdef CONFIG_DEBUG_FS
d67ce7da 503 xenvif_debugfs_delif(vif);
f51de243 504#endif /* CONFIG_DEBUG_FS */
d67ce7da
PD
505 xenvif_disconnect_data(vif);
506 for (queue_index = 0;
507 queue_index < vif->num_queues;
508 ++queue_index)
509 xenvif_deinit_queue(&vif->queues[queue_index]);
510
511 spin_lock(&vif->lock);
a254d8f9 512 queues = vif->queues;
d67ce7da
PD
513 vif->num_queues = 0;
514 vif->queues = NULL;
515 spin_unlock(&vif->lock);
516
a254d8f9
PD
517 vfree(queues);
518
d67ce7da 519 xenvif_disconnect_ctrl(vif);
f51de243 520 }
279f438e
PD
521}
522
ea732dff 523static void backend_connect(struct backend_info *be)
279f438e 524{
ea732dff
PD
525 if (be->vif)
526 connect(be);
527}
279f438e 528
ea732dff
PD
529static inline void backend_switch_state(struct backend_info *be,
530 enum xenbus_state state)
531{
532 struct xenbus_device *dev = be->dev;
533
534 pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state));
535 be->state = state;
536
537 /* If we are waiting for a hotplug script then defer the
538 * actual xenbus state change.
539 */
540 if (!be->have_hotplug_status_watch)
541 xenbus_switch_state(dev, state);
542}
543
544/* Handle backend state transitions:
545 *
cce94483 546 * The backend state starts in Initialising and the following transitions are
ea732dff
PD
547 * allowed.
548 *
cce94483
FM
549 * Initialising -> InitWait -> Connected
550 * \
551 * \ ^ \ |
552 * \ | \ |
553 * \ | \ |
554 * \ | \ |
555 * \ | \ |
556 * \ | \ |
557 * V | V V
ea732dff 558 *
cce94483 559 * Closed <-> Closing
ea732dff
PD
560 *
561 * The state argument specifies the eventual state of the backend and the
562 * function transitions to that state via the shortest path.
563 */
564static void set_backend_state(struct backend_info *be,
565 enum xenbus_state state)
566{
567 while (be->state != state) {
568 switch (be->state) {
cce94483
FM
569 case XenbusStateInitialising:
570 switch (state) {
571 case XenbusStateInitWait:
572 case XenbusStateConnected:
573 case XenbusStateClosing:
574 backend_switch_state(be, XenbusStateInitWait);
575 break;
576 case XenbusStateClosed:
577 backend_switch_state(be, XenbusStateClosed);
578 break;
579 default:
580 BUG();
581 }
582 break;
ea732dff
PD
583 case XenbusStateClosed:
584 switch (state) {
585 case XenbusStateInitWait:
586 case XenbusStateConnected:
ea732dff
PD
587 backend_switch_state(be, XenbusStateInitWait);
588 break;
589 case XenbusStateClosing:
590 backend_switch_state(be, XenbusStateClosing);
591 break;
592 default:
593 BUG();
594 }
595 break;
596 case XenbusStateInitWait:
597 switch (state) {
598 case XenbusStateConnected:
599 backend_connect(be);
600 backend_switch_state(be, XenbusStateConnected);
601 break;
602 case XenbusStateClosing:
603 case XenbusStateClosed:
604 backend_switch_state(be, XenbusStateClosing);
605 break;
606 default:
607 BUG();
608 }
609 break;
610 case XenbusStateConnected:
611 switch (state) {
612 case XenbusStateInitWait:
613 case XenbusStateClosing:
614 case XenbusStateClosed:
615 backend_disconnect(be);
616 backend_switch_state(be, XenbusStateClosing);
617 break;
618 default:
619 BUG();
620 }
621 break;
622 case XenbusStateClosing:
623 switch (state) {
624 case XenbusStateInitWait:
625 case XenbusStateConnected:
626 case XenbusStateClosed:
627 backend_switch_state(be, XenbusStateClosed);
628 break;
629 default:
630 BUG();
631 }
632 break;
633 default:
634 BUG();
635 }
f942dc25
IC
636 }
637}
638
639/**
640 * Callback received when the frontend's state changes.
641 */
642static void frontend_changed(struct xenbus_device *dev,
643 enum xenbus_state frontend_state)
644{
645 struct backend_info *be = dev_get_drvdata(&dev->dev);
646
ea732dff 647 pr_debug("%s -> %s\n", dev->otherend, xenbus_strstate(frontend_state));
f942dc25
IC
648
649 be->frontend_state = frontend_state;
650
651 switch (frontend_state) {
652 case XenbusStateInitialising:
ea732dff 653 set_backend_state(be, XenbusStateInitWait);
f942dc25
IC
654 break;
655
656 case XenbusStateInitialised:
657 break;
658
659 case XenbusStateConnected:
ea732dff 660 set_backend_state(be, XenbusStateConnected);
f942dc25
IC
661 break;
662
663 case XenbusStateClosing:
ea732dff 664 set_backend_state(be, XenbusStateClosing);
f942dc25
IC
665 break;
666
667 case XenbusStateClosed:
ea732dff 668 set_backend_state(be, XenbusStateClosed);
f942dc25
IC
669 if (xenbus_dev_is_online(dev))
670 break;
671 /* fall through if not online */
672 case XenbusStateUnknown:
ea732dff 673 set_backend_state(be, XenbusStateClosed);
f942dc25
IC
674 device_unregister(&dev->dev);
675 break;
676
677 default:
678 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
679 frontend_state);
680 break;
681 }
682}
683
684
685static void xen_net_read_rate(struct xenbus_device *dev,
686 unsigned long *bytes, unsigned long *usec)
687{
688 char *s, *e;
689 unsigned long b, u;
690 char *ratestr;
691
692 /* Default to unlimited bandwidth. */
693 *bytes = ~0UL;
694 *usec = 0;
695
696 ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
697 if (IS_ERR(ratestr))
698 return;
699
700 s = ratestr;
701 b = simple_strtoul(s, &e, 10);
702 if ((s == e) || (*e != ','))
703 goto fail;
704
705 s = e + 1;
706 u = simple_strtoul(s, &e, 10);
707 if ((s == e) || (*e != '\0'))
708 goto fail;
709
710 *bytes = b;
711 *usec = u;
712
713 kfree(ratestr);
714 return;
715
716 fail:
717 pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
718 kfree(ratestr);
719}
720
721static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
722{
723 char *s, *e, *macstr;
724 int i;
725
726 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
727 if (IS_ERR(macstr))
728 return PTR_ERR(macstr);
729
730 for (i = 0; i < ETH_ALEN; i++) {
731 mac[i] = simple_strtoul(s, &e, 16);
732 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
733 kfree(macstr);
734 return -ENOENT;
735 }
736 s = e+1;
737 }
738
739 kfree(macstr);
740 return 0;
741}
742
edafc132 743static void xen_net_rate_changed(struct xenbus_watch *watch,
5584ea25 744 const char *path, const char *token)
edafc132
PI
745{
746 struct xenvif *vif = container_of(watch, struct xenvif, credit_watch);
747 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
748 unsigned long credit_bytes;
749 unsigned long credit_usec;
750 unsigned int queue_index;
751
752 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
753 for (queue_index = 0; queue_index < vif->num_queues; queue_index++) {
754 struct xenvif_queue *queue = &vif->queues[queue_index];
755
756 queue->credit_bytes = credit_bytes;
757 queue->credit_usec = credit_usec;
758 if (!mod_timer_pending(&queue->credit_timeout, jiffies) &&
759 queue->remaining_credit > queue->credit_bytes) {
760 queue->remaining_credit = queue->credit_bytes;
761 }
762 }
763}
764
22fae97d
PD
765static int xen_register_credit_watch(struct xenbus_device *dev,
766 struct xenvif *vif)
edafc132
PI
767{
768 int err = 0;
769 char *node;
770 unsigned maxlen = strlen(dev->nodename) + sizeof("/rate");
771
12b322ac
PI
772 if (vif->credit_watch.node)
773 return -EADDRINUSE;
774
edafc132
PI
775 node = kmalloc(maxlen, GFP_KERNEL);
776 if (!node)
777 return -ENOMEM;
778 snprintf(node, maxlen, "%s/rate", dev->nodename);
779 vif->credit_watch.node = node;
780 vif->credit_watch.callback = xen_net_rate_changed;
781 err = register_xenbus_watch(&vif->credit_watch);
782 if (err) {
783 pr_err("Failed to set watcher %s\n", vif->credit_watch.node);
784 kfree(node);
785 vif->credit_watch.node = NULL;
786 vif->credit_watch.callback = NULL;
787 }
788 return err;
789}
790
22fae97d 791static void xen_unregister_credit_watch(struct xenvif *vif)
edafc132
PI
792{
793 if (vif->credit_watch.node) {
794 unregister_xenbus_watch(&vif->credit_watch);
795 kfree(vif->credit_watch.node);
796 vif->credit_watch.node = NULL;
797 }
798}
799
22fae97d 800static void xen_mcast_ctrl_changed(struct xenbus_watch *watch,
5584ea25 801 const char *path, const char *token)
22fae97d
PD
802{
803 struct xenvif *vif = container_of(watch, struct xenvif,
804 mcast_ctrl_watch);
805 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
22fae97d 806
f95842e7
JG
807 vif->multicast_control = !!xenbus_read_unsigned(dev->otherend,
808 "request-multicast-control", 0);
22fae97d
PD
809}
810
811static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev,
812 struct xenvif *vif)
813{
814 int err = 0;
815 char *node;
816 unsigned maxlen = strlen(dev->otherend) +
817 sizeof("/request-multicast-control");
818
819 if (vif->mcast_ctrl_watch.node) {
820 pr_err_ratelimited("Watch is already registered\n");
821 return -EADDRINUSE;
822 }
823
824 node = kmalloc(maxlen, GFP_KERNEL);
825 if (!node) {
826 pr_err("Failed to allocate memory for watch\n");
827 return -ENOMEM;
828 }
829 snprintf(node, maxlen, "%s/request-multicast-control",
830 dev->otherend);
831 vif->mcast_ctrl_watch.node = node;
832 vif->mcast_ctrl_watch.callback = xen_mcast_ctrl_changed;
833 err = register_xenbus_watch(&vif->mcast_ctrl_watch);
834 if (err) {
835 pr_err("Failed to set watcher %s\n",
836 vif->mcast_ctrl_watch.node);
837 kfree(node);
838 vif->mcast_ctrl_watch.node = NULL;
839 vif->mcast_ctrl_watch.callback = NULL;
840 }
841 return err;
842}
843
844static void xen_unregister_mcast_ctrl_watch(struct xenvif *vif)
845{
846 if (vif->mcast_ctrl_watch.node) {
847 unregister_xenbus_watch(&vif->mcast_ctrl_watch);
848 kfree(vif->mcast_ctrl_watch.node);
849 vif->mcast_ctrl_watch.node = NULL;
850 }
851}
852
853static void xen_register_watchers(struct xenbus_device *dev,
854 struct xenvif *vif)
855{
856 xen_register_credit_watch(dev, vif);
857 xen_register_mcast_ctrl_watch(dev, vif);
858}
859
860static void xen_unregister_watchers(struct xenvif *vif)
861{
862 xen_unregister_mcast_ctrl_watch(vif);
863 xen_unregister_credit_watch(vif);
864}
865
f942dc25
IC
866static void unregister_hotplug_status_watch(struct backend_info *be)
867{
868 if (be->have_hotplug_status_watch) {
869 unregister_xenbus_watch(&be->hotplug_status_watch);
870 kfree(be->hotplug_status_watch.node);
871 }
872 be->have_hotplug_status_watch = 0;
873}
874
875static void hotplug_status_changed(struct xenbus_watch *watch,
5584ea25
JG
876 const char *path,
877 const char *token)
f942dc25
IC
878{
879 struct backend_info *be = container_of(watch,
880 struct backend_info,
881 hotplug_status_watch);
882 char *str;
883 unsigned int len;
884
885 str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
886 if (IS_ERR(str))
887 return;
888 if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
ea732dff
PD
889 /* Complete any pending state change */
890 xenbus_switch_state(be->dev, be->state);
891
f942dc25
IC
892 /* Not interested in this watch anymore. */
893 unregister_hotplug_status_watch(be);
894 }
895 kfree(str);
896}
897
4e15ee2c
PD
898static int connect_ctrl_ring(struct backend_info *be)
899{
900 struct xenbus_device *dev = be->dev;
901 struct xenvif *vif = be->vif;
902 unsigned int val;
903 grant_ref_t ring_ref;
904 unsigned int evtchn;
905 int err;
906
6c27f99d
JB
907 err = xenbus_scanf(XBT_NIL, dev->otherend,
908 "ctrl-ring-ref", "%u", &val);
909 if (err < 0)
4e15ee2c
PD
910 goto done; /* The frontend does not have a control ring */
911
912 ring_ref = val;
913
6c27f99d
JB
914 err = xenbus_scanf(XBT_NIL, dev->otherend,
915 "event-channel-ctrl", "%u", &val);
916 if (err < 0) {
4e15ee2c
PD
917 xenbus_dev_fatal(dev, err,
918 "reading %s/event-channel-ctrl",
919 dev->otherend);
920 goto fail;
921 }
922
923 evtchn = val;
924
925 err = xenvif_connect_ctrl(vif, ring_ref, evtchn);
926 if (err) {
927 xenbus_dev_fatal(dev, err,
928 "mapping shared-frame %u port %u",
929 ring_ref, evtchn);
930 goto fail;
931 }
932
933done:
934 return 0;
935
936fail:
937 return err;
938}
939
f942dc25
IC
940static void connect(struct backend_info *be)
941{
942 int err;
943 struct xenbus_device *dev = be->dev;
e9ce7cb6
WL
944 unsigned long credit_bytes, credit_usec;
945 unsigned int queue_index;
8d3d53b3 946 unsigned int requested_num_queues;
e9ce7cb6 947 struct xenvif_queue *queue;
f942dc25 948
8d3d53b3
AB
949 /* Check whether the frontend requested multiple queues
950 * and read the number requested.
951 */
f95842e7
JG
952 requested_num_queues = xenbus_read_unsigned(dev->otherend,
953 "multi-queue-num-queues", 1);
954 if (requested_num_queues > xenvif_max_queues) {
8d3d53b3 955 /* buggy or malicious guest */
0f06ac3b 956 xenbus_dev_fatal(dev, -EINVAL,
8d3d53b3
AB
957 "guest requested %u queues, exceeding the maximum of %u.",
958 requested_num_queues, xenvif_max_queues);
959 return;
960 }
961
f942dc25
IC
962 err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
963 if (err) {
964 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
965 return;
966 }
967
e9ce7cb6 968 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
12b322ac 969 xen_unregister_watchers(be->vif);
edafc132 970 xen_register_watchers(dev, be->vif);
e9ce7cb6
WL
971 read_xenbus_vif_flags(be);
972
4e15ee2c
PD
973 err = connect_ctrl_ring(be);
974 if (err) {
975 xenbus_dev_fatal(dev, err, "connecting control ring");
976 return;
977 }
978
8d3d53b3 979 /* Use the number of queues requested by the frontend */
e9ce7cb6
WL
980 be->vif->queues = vzalloc(requested_num_queues *
981 sizeof(struct xenvif_queue));
833b8f18
IY
982 if (!be->vif->queues) {
983 xenbus_dev_fatal(dev, -ENOMEM,
984 "allocating queues");
985 return;
986 }
987
f7b50c4e 988 be->vif->num_queues = requested_num_queues;
ecf08d2d 989 be->vif->stalled_queues = requested_num_queues;
e9ce7cb6
WL
990
991 for (queue_index = 0; queue_index < requested_num_queues; ++queue_index) {
992 queue = &be->vif->queues[queue_index];
993 queue->vif = be->vif;
994 queue->id = queue_index;
995 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
996 be->vif->dev->name, queue->id);
997
998 err = xenvif_init_queue(queue);
8d3d53b3
AB
999 if (err) {
1000 /* xenvif_init_queue() cleans up after itself on
1001 * failure, but we need to clean up any previously
1002 * initialised queues. Set num_queues to i so that
1003 * earlier queues can be destroyed using the regular
1004 * disconnect logic.
1005 */
f7b50c4e 1006 be->vif->num_queues = queue_index;
e9ce7cb6 1007 goto err;
8d3d53b3 1008 }
e9ce7cb6 1009
ce0e5c52 1010 queue->credit_bytes = credit_bytes;
e9ce7cb6 1011 queue->remaining_credit = credit_bytes;
07ff890d 1012 queue->credit_usec = credit_usec;
e9ce7cb6 1013
4e15ee2c 1014 err = connect_data_rings(be, queue);
8d3d53b3 1015 if (err) {
4e15ee2c
PD
1016 /* connect_data_rings() cleans up after itself on
1017 * failure, but we need to clean up after
1018 * xenvif_init_queue() here, and also clean up any
1019 * previously initialised queues.
8d3d53b3
AB
1020 */
1021 xenvif_deinit_queue(queue);
f7b50c4e 1022 be->vif->num_queues = queue_index;
e9ce7cb6 1023 goto err;
8d3d53b3 1024 }
628fa76b
WL
1025 }
1026
f51de243 1027#ifdef CONFIG_DEBUG_FS
628fa76b 1028 xenvif_debugfs_addif(be->vif);
f51de243 1029#endif /* CONFIG_DEBUG_FS */
e9ce7cb6 1030
f7b50c4e
WL
1031 /* Initialisation completed, tell core driver the number of
1032 * active queues.
1033 */
1034 rtnl_lock();
1035 netif_set_real_num_tx_queues(be->vif->dev, requested_num_queues);
1036 netif_set_real_num_rx_queues(be->vif->dev, requested_num_queues);
1037 rtnl_unlock();
1038
e9ce7cb6 1039 xenvif_carrier_on(be->vif);
f942dc25
IC
1040
1041 unregister_hotplug_status_watch(be);
1042 err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
1043 hotplug_status_changed,
1044 "%s/%s", dev->nodename, "hotplug-status");
ea732dff 1045 if (!err)
f942dc25 1046 be->have_hotplug_status_watch = 1;
f942dc25 1047
e9ce7cb6
WL
1048 netif_tx_wake_all_queues(be->vif->dev);
1049
1050 return;
1051
1052err:
f7b50c4e 1053 if (be->vif->num_queues > 0)
4e15ee2c 1054 xenvif_disconnect_data(be->vif); /* Clean up existing queues */
9a6cdf52
ID
1055 for (queue_index = 0; queue_index < be->vif->num_queues; ++queue_index)
1056 xenvif_deinit_queue(&be->vif->queues[queue_index]);
e9ce7cb6
WL
1057 vfree(be->vif->queues);
1058 be->vif->queues = NULL;
f7b50c4e 1059 be->vif->num_queues = 0;
4e15ee2c 1060 xenvif_disconnect_ctrl(be->vif);
e9ce7cb6 1061 return;
f942dc25
IC
1062}
1063
1064
4e15ee2c
PD
1065static int connect_data_rings(struct backend_info *be,
1066 struct xenvif_queue *queue)
f942dc25 1067{
f942dc25 1068 struct xenbus_device *dev = be->dev;
f7b50c4e 1069 unsigned int num_queues = queue->vif->num_queues;
f942dc25 1070 unsigned long tx_ring_ref, rx_ring_ref;
e9ce7cb6 1071 unsigned int tx_evtchn, rx_evtchn;
f942dc25 1072 int err;
8d3d53b3
AB
1073 char *xspath;
1074 size_t xspathsize;
1075 const size_t xenstore_path_ext_size = 11; /* sufficient for "/queue-NNN" */
1076
1077 /* If the frontend requested 1 queue, or we have fallen back
1078 * to single queue due to lack of frontend support for multi-
1079 * queue, expect the remaining XenStore keys in the toplevel
1080 * directory. Otherwise, expect them in a subdirectory called
1081 * queue-N.
1082 */
1083 if (num_queues == 1) {
1084 xspath = kzalloc(strlen(dev->otherend) + 1, GFP_KERNEL);
1085 if (!xspath) {
1086 xenbus_dev_fatal(dev, -ENOMEM,
1087 "reading ring references");
1088 return -ENOMEM;
1089 }
1090 strcpy(xspath, dev->otherend);
1091 } else {
1092 xspathsize = strlen(dev->otherend) + xenstore_path_ext_size;
1093 xspath = kzalloc(xspathsize, GFP_KERNEL);
1094 if (!xspath) {
1095 xenbus_dev_fatal(dev, -ENOMEM,
1096 "reading ring references");
1097 return -ENOMEM;
1098 }
1099 snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend,
1100 queue->id);
1101 }
f942dc25 1102
8d3d53b3 1103 err = xenbus_gather(XBT_NIL, xspath,
f942dc25 1104 "tx-ring-ref", "%lu", &tx_ring_ref,
e1f00a69 1105 "rx-ring-ref", "%lu", &rx_ring_ref, NULL);
f942dc25
IC
1106 if (err) {
1107 xenbus_dev_fatal(dev, err,
e1f00a69 1108 "reading %s/ring-ref",
8d3d53b3
AB
1109 xspath);
1110 goto err;
f942dc25
IC
1111 }
1112
e1f00a69 1113 /* Try split event channels first, then single event channel. */
8d3d53b3 1114 err = xenbus_gather(XBT_NIL, xspath,
e1f00a69
WL
1115 "event-channel-tx", "%u", &tx_evtchn,
1116 "event-channel-rx", "%u", &rx_evtchn, NULL);
1117 if (err < 0) {
8d3d53b3 1118 err = xenbus_scanf(XBT_NIL, xspath,
e1f00a69
WL
1119 "event-channel", "%u", &tx_evtchn);
1120 if (err < 0) {
1121 xenbus_dev_fatal(dev, err,
1122 "reading %s/event-channel(-tx/rx)",
8d3d53b3
AB
1123 xspath);
1124 goto err;
e1f00a69
WL
1125 }
1126 rx_evtchn = tx_evtchn;
1127 }
1128
e9ce7cb6 1129 /* Map the shared frame, irq etc. */
4e15ee2c
PD
1130 err = xenvif_connect_data(queue, tx_ring_ref, rx_ring_ref,
1131 tx_evtchn, rx_evtchn);
e9ce7cb6
WL
1132 if (err) {
1133 xenbus_dev_fatal(dev, err,
1134 "mapping shared-frames %lu/%lu port tx %u rx %u",
1135 tx_ring_ref, rx_ring_ref,
1136 tx_evtchn, rx_evtchn);
8d3d53b3 1137 goto err;
e9ce7cb6
WL
1138 }
1139
8d3d53b3
AB
1140 err = 0;
1141err: /* Regular return falls through with err == 0 */
1142 kfree(xspath);
1143 return err;
e9ce7cb6
WL
1144}
1145
1146static int read_xenbus_vif_flags(struct backend_info *be)
1147{
1148 struct xenvif *vif = be->vif;
1149 struct xenbus_device *dev = be->dev;
1150 unsigned int rx_copy;
f95842e7 1151 int err;
e9ce7cb6 1152
f942dc25
IC
1153 err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
1154 &rx_copy);
1155 if (err == -ENOENT) {
1156 err = 0;
1157 rx_copy = 0;
1158 }
1159 if (err < 0) {
1160 xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
1161 dev->otherend);
1162 return err;
1163 }
1164 if (!rx_copy)
1165 return -EOPNOTSUPP;
1166
f95842e7 1167 if (!xenbus_read_unsigned(dev->otherend, "feature-rx-notify", 0)) {
26c0e102
DV
1168 /* - Reduce drain timeout to poll more frequently for
1169 * Rx requests.
1170 * - Disable Rx stall detection.
1171 */
1172 be->vif->drain_timeout = msecs_to_jiffies(30);
1173 be->vif->stall_timeout = 0;
f942dc25
IC
1174 }
1175
f95842e7 1176 vif->can_sg = !!xenbus_read_unsigned(dev->otherend, "feature-sg", 0);
f942dc25 1177
82cada22 1178 vif->gso_mask = 0;
82cada22 1179
f95842e7 1180 if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv4", 0))
82cada22 1181 vif->gso_mask |= GSO_BIT(TCPV4);
f942dc25 1182
f95842e7 1183 if (xenbus_read_unsigned(dev->otherend, "feature-gso-tcpv6", 0))
82cada22
PD
1184 vif->gso_mask |= GSO_BIT(TCPV6);
1185
f95842e7
JG
1186 vif->ip_csum = !xenbus_read_unsigned(dev->otherend,
1187 "feature-no-csum-offload", 0);
146c8a77 1188
f95842e7
JG
1189 vif->ipv6_csum = !!xenbus_read_unsigned(dev->otherend,
1190 "feature-ipv6-csum-offload", 0);
f942dc25 1191
f942dc25
IC
1192 return 0;
1193}
1194
f942dc25
IC
1195static const struct xenbus_device_id netback_ids[] = {
1196 { "vif" },
1197 { "" }
1198};
1199
95afae48
DV
1200static struct xenbus_driver netback_driver = {
1201 .ids = netback_ids,
f942dc25
IC
1202 .probe = netback_probe,
1203 .remove = netback_remove,
1204 .uevent = netback_uevent,
1205 .otherend_changed = frontend_changed,
95afae48 1206};
f942dc25
IC
1207
1208int xenvif_xenbus_init(void)
1209{
73db144b 1210 return xenbus_register_backend(&netback_driver);
f942dc25 1211}
b103f358
WL
1212
1213void xenvif_xenbus_fini(void)
1214{
1215 return xenbus_unregister_driver(&netback_driver);
1216}