net/mlx4_en: Move filters cleanup to a proper location
[linux/fpc-iii.git] / drivers / net / xen-netback / xenbus.c
blob6a31f2610c2378185c4274cd9828cd5117ca61ea
1 /*
2 * Xenbus code for netif backend
4 * Copyright (C) 2005 Rusty Russell <rusty@rustcorp.com.au>
5 * Copyright (C) 2005 XenSource Ltd
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.
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.
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, see <http://www.gnu.org/licenses/>.
21 #include "common.h"
22 #include <linux/vmalloc.h>
23 #include <linux/rtnetlink.h>
25 struct backend_info {
26 struct xenbus_device *dev;
27 struct xenvif *vif;
29 /* This is the state that will be reflected in xenstore when any
30 * active hotplug script completes.
32 enum xenbus_state state;
34 enum xenbus_state frontend_state;
35 struct xenbus_watch hotplug_status_watch;
36 u8 have_hotplug_status_watch:1;
38 const char *hotplug_script;
41 static int connect_data_rings(struct backend_info *be,
42 struct xenvif_queue *queue);
43 static void connect(struct backend_info *be);
44 static int read_xenbus_vif_flags(struct backend_info *be);
45 static int backend_create_xenvif(struct backend_info *be);
46 static void unregister_hotplug_status_watch(struct backend_info *be);
47 static void xen_unregister_watchers(struct xenvif *vif);
48 static void set_backend_state(struct backend_info *be,
49 enum xenbus_state state);
51 #ifdef CONFIG_DEBUG_FS
52 struct dentry *xen_netback_dbg_root = NULL;
54 static int xenvif_read_io_ring(struct seq_file *m, void *v)
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;
59 struct netdev_queue *dev_queue;
61 if (tx_ring->sring) {
62 struct xen_netif_tx_sring *sring = tx_ring->sring;
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);
89 if (rx_ring->sring) {
90 struct xen_netif_rx_sring *sring = rx_ring->sring;
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);
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);
120 dev_queue = netdev_get_tx_queue(queue->vif->dev, queue->id);
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");
127 return 0;
130 #define XENVIF_KICK_STR "kick"
131 #define BUFFER_SIZE 32
133 static ssize_t
134 xenvif_write_io_ring(struct file *filp, const char __user *buf, size_t count,
135 loff_t *ppos)
137 struct xenvif_queue *queue =
138 ((struct seq_file *)filp->private_data)->private;
139 int len;
140 char write[BUFFER_SIZE];
142 /* don't allow partial writes and check the length */
143 if (*ppos != 0)
144 return 0;
145 if (count >= sizeof(write))
146 return -ENOSPC;
148 len = simple_write_to_buffer(write,
149 sizeof(write) - 1,
150 ppos,
151 buf,
152 count);
153 if (len < 0)
154 return len;
156 write[len] = '\0';
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;
165 return count;
168 static int xenvif_dump_open(struct inode *inode, struct file *filp)
170 int ret;
171 void *queue = NULL;
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;
180 static const struct file_operations xenvif_dbg_io_ring_ops_fops = {
181 .owner = THIS_MODULE,
182 .open = xenvif_dump_open,
183 .read = seq_read,
184 .llseek = seq_lseek,
185 .release = single_release,
186 .write = xenvif_write_io_ring,
189 static void xenvif_debugfs_addif(struct xenvif *vif)
191 struct dentry *pfile;
192 int i;
194 if (IS_ERR_OR_NULL(xen_netback_dbg_root))
195 return;
197 vif->xenvif_dbg_root = debugfs_create_dir(vif->dev->name,
198 xen_netback_dbg_root);
199 if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root)) {
200 for (i = 0; i < vif->num_queues; ++i) {
201 char filename[sizeof("io_ring_q") + 4];
203 snprintf(filename, sizeof(filename), "io_ring_q%d", i);
204 pfile = debugfs_create_file(filename,
205 S_IRUSR | S_IWUSR,
206 vif->xenvif_dbg_root,
207 &vif->queues[i],
208 &xenvif_dbg_io_ring_ops_fops);
209 if (IS_ERR_OR_NULL(pfile))
210 pr_warn("Creation of io_ring file returned %ld!\n",
211 PTR_ERR(pfile));
213 } else
214 netdev_warn(vif->dev,
215 "Creation of vif debugfs dir returned %ld!\n",
216 PTR_ERR(vif->xenvif_dbg_root));
219 static void xenvif_debugfs_delif(struct xenvif *vif)
221 if (IS_ERR_OR_NULL(xen_netback_dbg_root))
222 return;
224 if (!IS_ERR_OR_NULL(vif->xenvif_dbg_root))
225 debugfs_remove_recursive(vif->xenvif_dbg_root);
226 vif->xenvif_dbg_root = NULL;
228 #endif /* CONFIG_DEBUG_FS */
230 static int netback_remove(struct xenbus_device *dev)
232 struct backend_info *be = dev_get_drvdata(&dev->dev);
234 set_backend_state(be, XenbusStateClosed);
236 unregister_hotplug_status_watch(be);
237 if (be->vif) {
238 kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
239 xen_unregister_watchers(be->vif);
240 xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
241 xenvif_free(be->vif);
242 be->vif = NULL;
244 kfree(be->hotplug_script);
245 kfree(be);
246 dev_set_drvdata(&dev->dev, NULL);
247 return 0;
252 * Entry point to this code when a new device is created. Allocate the basic
253 * structures and switch to InitWait.
255 static int netback_probe(struct xenbus_device *dev,
256 const struct xenbus_device_id *id)
258 const char *message;
259 struct xenbus_transaction xbt;
260 int err;
261 int sg;
262 const char *script;
263 struct backend_info *be = kzalloc(sizeof(struct backend_info),
264 GFP_KERNEL);
265 if (!be) {
266 xenbus_dev_fatal(dev, -ENOMEM,
267 "allocating backend structure");
268 return -ENOMEM;
271 be->dev = dev;
272 dev_set_drvdata(&dev->dev, be);
274 sg = 1;
276 do {
277 err = xenbus_transaction_start(&xbt);
278 if (err) {
279 xenbus_dev_fatal(dev, err, "starting transaction");
280 goto fail;
283 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
284 if (err) {
285 message = "writing feature-sg";
286 goto abort_transaction;
289 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
290 "%d", sg);
291 if (err) {
292 message = "writing feature-gso-tcpv4";
293 goto abort_transaction;
296 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv6",
297 "%d", sg);
298 if (err) {
299 message = "writing feature-gso-tcpv6";
300 goto abort_transaction;
303 /* We support partial checksum setup for IPv6 packets */
304 err = xenbus_printf(xbt, dev->nodename,
305 "feature-ipv6-csum-offload",
306 "%d", 1);
307 if (err) {
308 message = "writing feature-ipv6-csum-offload";
309 goto abort_transaction;
312 /* We support rx-copy path. */
313 err = xenbus_printf(xbt, dev->nodename,
314 "feature-rx-copy", "%d", 1);
315 if (err) {
316 message = "writing feature-rx-copy";
317 goto abort_transaction;
321 * We don't support rx-flip path (except old guests who don't
322 * grok this feature flag).
324 err = xenbus_printf(xbt, dev->nodename,
325 "feature-rx-flip", "%d", 0);
326 if (err) {
327 message = "writing feature-rx-flip";
328 goto abort_transaction;
331 /* We support dynamic multicast-control. */
332 err = xenbus_printf(xbt, dev->nodename,
333 "feature-multicast-control", "%d", 1);
334 if (err) {
335 message = "writing feature-multicast-control";
336 goto abort_transaction;
339 err = xenbus_printf(xbt, dev->nodename,
340 "feature-dynamic-multicast-control",
341 "%d", 1);
342 if (err) {
343 message = "writing feature-dynamic-multicast-control";
344 goto abort_transaction;
347 err = xenbus_transaction_end(xbt, 0);
348 } while (err == -EAGAIN);
350 if (err) {
351 xenbus_dev_fatal(dev, err, "completing transaction");
352 goto fail;
356 * Split event channels support, this is optional so it is not
357 * put inside the above loop.
359 err = xenbus_printf(XBT_NIL, dev->nodename,
360 "feature-split-event-channels",
361 "%u", separate_tx_rx_irq);
362 if (err)
363 pr_debug("Error writing feature-split-event-channels\n");
365 /* Multi-queue support: This is an optional feature. */
366 err = xenbus_printf(XBT_NIL, dev->nodename,
367 "multi-queue-max-queues", "%u", xenvif_max_queues);
368 if (err)
369 pr_debug("Error writing multi-queue-max-queues\n");
371 err = xenbus_printf(XBT_NIL, dev->nodename,
372 "feature-ctrl-ring",
373 "%u", true);
374 if (err)
375 pr_debug("Error writing feature-ctrl-ring\n");
377 script = xenbus_read(XBT_NIL, dev->nodename, "script", NULL);
378 if (IS_ERR(script)) {
379 err = PTR_ERR(script);
380 xenbus_dev_fatal(dev, err, "reading script");
381 goto fail;
384 be->hotplug_script = script;
386 err = xenbus_switch_state(dev, XenbusStateInitWait);
387 if (err)
388 goto fail;
390 be->state = XenbusStateInitWait;
392 /* This kicks hotplug scripts, so do it immediately. */
393 err = backend_create_xenvif(be);
394 if (err)
395 goto fail;
397 return 0;
399 abort_transaction:
400 xenbus_transaction_end(xbt, 1);
401 xenbus_dev_fatal(dev, err, "%s", message);
402 fail:
403 pr_debug("failed\n");
404 netback_remove(dev);
405 return err;
410 * Handle the creation of the hotplug script environment. We add the script
411 * and vif variables to the environment, for the benefit of the vif-* hotplug
412 * scripts.
414 static int netback_uevent(struct xenbus_device *xdev,
415 struct kobj_uevent_env *env)
417 struct backend_info *be = dev_get_drvdata(&xdev->dev);
419 if (!be)
420 return 0;
422 if (add_uevent_var(env, "script=%s", be->hotplug_script))
423 return -ENOMEM;
425 if (!be->vif)
426 return 0;
428 return add_uevent_var(env, "vif=%s", be->vif->dev->name);
432 static int backend_create_xenvif(struct backend_info *be)
434 int err;
435 long handle;
436 struct xenbus_device *dev = be->dev;
437 struct xenvif *vif;
439 if (be->vif != NULL)
440 return 0;
442 err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
443 if (err != 1) {
444 xenbus_dev_fatal(dev, err, "reading handle");
445 return (err < 0) ? err : -EINVAL;
448 vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
449 if (IS_ERR(vif)) {
450 err = PTR_ERR(vif);
451 xenbus_dev_fatal(dev, err, "creating interface");
452 return err;
454 be->vif = vif;
456 kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
457 return 0;
460 static void backend_disconnect(struct backend_info *be)
462 if (be->vif) {
463 xen_unregister_watchers(be->vif);
464 #ifdef CONFIG_DEBUG_FS
465 xenvif_debugfs_delif(be->vif);
466 #endif /* CONFIG_DEBUG_FS */
467 xenvif_disconnect_data(be->vif);
468 xenvif_disconnect_ctrl(be->vif);
472 static void backend_connect(struct backend_info *be)
474 if (be->vif)
475 connect(be);
478 static inline void backend_switch_state(struct backend_info *be,
479 enum xenbus_state state)
481 struct xenbus_device *dev = be->dev;
483 pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state));
484 be->state = state;
486 /* If we are waiting for a hotplug script then defer the
487 * actual xenbus state change.
489 if (!be->have_hotplug_status_watch)
490 xenbus_switch_state(dev, state);
493 /* Handle backend state transitions:
495 * The backend state starts in InitWait and the following transitions are
496 * allowed.
498 * InitWait -> Connected
500 * ^ \ |
501 * | \ |
502 * | \ |
503 * | \ |
504 * | \ |
505 * | \ |
506 * | V V
508 * Closed <-> Closing
510 * The state argument specifies the eventual state of the backend and the
511 * function transitions to that state via the shortest path.
513 static void set_backend_state(struct backend_info *be,
514 enum xenbus_state state)
516 while (be->state != state) {
517 switch (be->state) {
518 case XenbusStateClosed:
519 switch (state) {
520 case XenbusStateInitWait:
521 case XenbusStateConnected:
522 backend_switch_state(be, XenbusStateInitWait);
523 break;
524 case XenbusStateClosing:
525 backend_switch_state(be, XenbusStateClosing);
526 break;
527 default:
528 BUG();
530 break;
531 case XenbusStateInitWait:
532 switch (state) {
533 case XenbusStateConnected:
534 backend_connect(be);
535 backend_switch_state(be, XenbusStateConnected);
536 break;
537 case XenbusStateClosing:
538 case XenbusStateClosed:
539 backend_switch_state(be, XenbusStateClosing);
540 break;
541 default:
542 BUG();
544 break;
545 case XenbusStateConnected:
546 switch (state) {
547 case XenbusStateInitWait:
548 case XenbusStateClosing:
549 case XenbusStateClosed:
550 backend_disconnect(be);
551 backend_switch_state(be, XenbusStateClosing);
552 break;
553 default:
554 BUG();
556 break;
557 case XenbusStateClosing:
558 switch (state) {
559 case XenbusStateInitWait:
560 case XenbusStateConnected:
561 case XenbusStateClosed:
562 backend_switch_state(be, XenbusStateClosed);
563 break;
564 default:
565 BUG();
567 break;
568 default:
569 BUG();
575 * Callback received when the frontend's state changes.
577 static void frontend_changed(struct xenbus_device *dev,
578 enum xenbus_state frontend_state)
580 struct backend_info *be = dev_get_drvdata(&dev->dev);
582 pr_debug("%s -> %s\n", dev->otherend, xenbus_strstate(frontend_state));
584 be->frontend_state = frontend_state;
586 switch (frontend_state) {
587 case XenbusStateInitialising:
588 set_backend_state(be, XenbusStateInitWait);
589 break;
591 case XenbusStateInitialised:
592 break;
594 case XenbusStateConnected:
595 set_backend_state(be, XenbusStateConnected);
596 break;
598 case XenbusStateClosing:
599 set_backend_state(be, XenbusStateClosing);
600 break;
602 case XenbusStateClosed:
603 set_backend_state(be, XenbusStateClosed);
604 if (xenbus_dev_is_online(dev))
605 break;
606 /* fall through if not online */
607 case XenbusStateUnknown:
608 set_backend_state(be, XenbusStateClosed);
609 device_unregister(&dev->dev);
610 break;
612 default:
613 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
614 frontend_state);
615 break;
620 static void xen_net_read_rate(struct xenbus_device *dev,
621 unsigned long *bytes, unsigned long *usec)
623 char *s, *e;
624 unsigned long b, u;
625 char *ratestr;
627 /* Default to unlimited bandwidth. */
628 *bytes = ~0UL;
629 *usec = 0;
631 ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
632 if (IS_ERR(ratestr))
633 return;
635 s = ratestr;
636 b = simple_strtoul(s, &e, 10);
637 if ((s == e) || (*e != ','))
638 goto fail;
640 s = e + 1;
641 u = simple_strtoul(s, &e, 10);
642 if ((s == e) || (*e != '\0'))
643 goto fail;
645 *bytes = b;
646 *usec = u;
648 kfree(ratestr);
649 return;
651 fail:
652 pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
653 kfree(ratestr);
656 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
658 char *s, *e, *macstr;
659 int i;
661 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
662 if (IS_ERR(macstr))
663 return PTR_ERR(macstr);
665 for (i = 0; i < ETH_ALEN; i++) {
666 mac[i] = simple_strtoul(s, &e, 16);
667 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
668 kfree(macstr);
669 return -ENOENT;
671 s = e+1;
674 kfree(macstr);
675 return 0;
678 static void xen_net_rate_changed(struct xenbus_watch *watch,
679 const char **vec, unsigned int len)
681 struct xenvif *vif = container_of(watch, struct xenvif, credit_watch);
682 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
683 unsigned long credit_bytes;
684 unsigned long credit_usec;
685 unsigned int queue_index;
687 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
688 for (queue_index = 0; queue_index < vif->num_queues; queue_index++) {
689 struct xenvif_queue *queue = &vif->queues[queue_index];
691 queue->credit_bytes = credit_bytes;
692 queue->credit_usec = credit_usec;
693 if (!mod_timer_pending(&queue->credit_timeout, jiffies) &&
694 queue->remaining_credit > queue->credit_bytes) {
695 queue->remaining_credit = queue->credit_bytes;
700 static int xen_register_credit_watch(struct xenbus_device *dev,
701 struct xenvif *vif)
703 int err = 0;
704 char *node;
705 unsigned maxlen = strlen(dev->nodename) + sizeof("/rate");
707 if (vif->credit_watch.node)
708 return -EADDRINUSE;
710 node = kmalloc(maxlen, GFP_KERNEL);
711 if (!node)
712 return -ENOMEM;
713 snprintf(node, maxlen, "%s/rate", dev->nodename);
714 vif->credit_watch.node = node;
715 vif->credit_watch.callback = xen_net_rate_changed;
716 err = register_xenbus_watch(&vif->credit_watch);
717 if (err) {
718 pr_err("Failed to set watcher %s\n", vif->credit_watch.node);
719 kfree(node);
720 vif->credit_watch.node = NULL;
721 vif->credit_watch.callback = NULL;
723 return err;
726 static void xen_unregister_credit_watch(struct xenvif *vif)
728 if (vif->credit_watch.node) {
729 unregister_xenbus_watch(&vif->credit_watch);
730 kfree(vif->credit_watch.node);
731 vif->credit_watch.node = NULL;
735 static void xen_mcast_ctrl_changed(struct xenbus_watch *watch,
736 const char **vec, unsigned int len)
738 struct xenvif *vif = container_of(watch, struct xenvif,
739 mcast_ctrl_watch);
740 struct xenbus_device *dev = xenvif_to_xenbus_device(vif);
741 int val;
743 if (xenbus_scanf(XBT_NIL, dev->otherend,
744 "request-multicast-control", "%d", &val) < 0)
745 val = 0;
746 vif->multicast_control = !!val;
749 static int xen_register_mcast_ctrl_watch(struct xenbus_device *dev,
750 struct xenvif *vif)
752 int err = 0;
753 char *node;
754 unsigned maxlen = strlen(dev->otherend) +
755 sizeof("/request-multicast-control");
757 if (vif->mcast_ctrl_watch.node) {
758 pr_err_ratelimited("Watch is already registered\n");
759 return -EADDRINUSE;
762 node = kmalloc(maxlen, GFP_KERNEL);
763 if (!node) {
764 pr_err("Failed to allocate memory for watch\n");
765 return -ENOMEM;
767 snprintf(node, maxlen, "%s/request-multicast-control",
768 dev->otherend);
769 vif->mcast_ctrl_watch.node = node;
770 vif->mcast_ctrl_watch.callback = xen_mcast_ctrl_changed;
771 err = register_xenbus_watch(&vif->mcast_ctrl_watch);
772 if (err) {
773 pr_err("Failed to set watcher %s\n",
774 vif->mcast_ctrl_watch.node);
775 kfree(node);
776 vif->mcast_ctrl_watch.node = NULL;
777 vif->mcast_ctrl_watch.callback = NULL;
779 return err;
782 static void xen_unregister_mcast_ctrl_watch(struct xenvif *vif)
784 if (vif->mcast_ctrl_watch.node) {
785 unregister_xenbus_watch(&vif->mcast_ctrl_watch);
786 kfree(vif->mcast_ctrl_watch.node);
787 vif->mcast_ctrl_watch.node = NULL;
791 static void xen_register_watchers(struct xenbus_device *dev,
792 struct xenvif *vif)
794 xen_register_credit_watch(dev, vif);
795 xen_register_mcast_ctrl_watch(dev, vif);
798 static void xen_unregister_watchers(struct xenvif *vif)
800 xen_unregister_mcast_ctrl_watch(vif);
801 xen_unregister_credit_watch(vif);
804 static void unregister_hotplug_status_watch(struct backend_info *be)
806 if (be->have_hotplug_status_watch) {
807 unregister_xenbus_watch(&be->hotplug_status_watch);
808 kfree(be->hotplug_status_watch.node);
810 be->have_hotplug_status_watch = 0;
813 static void hotplug_status_changed(struct xenbus_watch *watch,
814 const char **vec,
815 unsigned int vec_size)
817 struct backend_info *be = container_of(watch,
818 struct backend_info,
819 hotplug_status_watch);
820 char *str;
821 unsigned int len;
823 str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
824 if (IS_ERR(str))
825 return;
826 if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
827 /* Complete any pending state change */
828 xenbus_switch_state(be->dev, be->state);
830 /* Not interested in this watch anymore. */
831 unregister_hotplug_status_watch(be);
833 kfree(str);
836 static int connect_ctrl_ring(struct backend_info *be)
838 struct xenbus_device *dev = be->dev;
839 struct xenvif *vif = be->vif;
840 unsigned int val;
841 grant_ref_t ring_ref;
842 unsigned int evtchn;
843 int err;
845 err = xenbus_gather(XBT_NIL, dev->otherend,
846 "ctrl-ring-ref", "%u", &val, NULL);
847 if (err)
848 goto done; /* The frontend does not have a control ring */
850 ring_ref = val;
852 err = xenbus_gather(XBT_NIL, dev->otherend,
853 "event-channel-ctrl", "%u", &val, NULL);
854 if (err) {
855 xenbus_dev_fatal(dev, err,
856 "reading %s/event-channel-ctrl",
857 dev->otherend);
858 goto fail;
861 evtchn = val;
863 err = xenvif_connect_ctrl(vif, ring_ref, evtchn);
864 if (err) {
865 xenbus_dev_fatal(dev, err,
866 "mapping shared-frame %u port %u",
867 ring_ref, evtchn);
868 goto fail;
871 done:
872 return 0;
874 fail:
875 return err;
878 static void connect(struct backend_info *be)
880 int err;
881 struct xenbus_device *dev = be->dev;
882 unsigned long credit_bytes, credit_usec;
883 unsigned int queue_index;
884 unsigned int requested_num_queues;
885 struct xenvif_queue *queue;
887 /* Check whether the frontend requested multiple queues
888 * and read the number requested.
890 err = xenbus_scanf(XBT_NIL, dev->otherend,
891 "multi-queue-num-queues",
892 "%u", &requested_num_queues);
893 if (err < 0) {
894 requested_num_queues = 1; /* Fall back to single queue */
895 } else if (requested_num_queues > xenvif_max_queues) {
896 /* buggy or malicious guest */
897 xenbus_dev_fatal(dev, err,
898 "guest requested %u queues, exceeding the maximum of %u.",
899 requested_num_queues, xenvif_max_queues);
900 return;
903 err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
904 if (err) {
905 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
906 return;
909 xen_net_read_rate(dev, &credit_bytes, &credit_usec);
910 xen_unregister_watchers(be->vif);
911 xen_register_watchers(dev, be->vif);
912 read_xenbus_vif_flags(be);
914 err = connect_ctrl_ring(be);
915 if (err) {
916 xenbus_dev_fatal(dev, err, "connecting control ring");
917 return;
920 /* Use the number of queues requested by the frontend */
921 be->vif->queues = vzalloc(requested_num_queues *
922 sizeof(struct xenvif_queue));
923 if (!be->vif->queues) {
924 xenbus_dev_fatal(dev, -ENOMEM,
925 "allocating queues");
926 return;
929 be->vif->num_queues = requested_num_queues;
930 be->vif->stalled_queues = requested_num_queues;
932 for (queue_index = 0; queue_index < requested_num_queues; ++queue_index) {
933 queue = &be->vif->queues[queue_index];
934 queue->vif = be->vif;
935 queue->id = queue_index;
936 snprintf(queue->name, sizeof(queue->name), "%s-q%u",
937 be->vif->dev->name, queue->id);
939 err = xenvif_init_queue(queue);
940 if (err) {
941 /* xenvif_init_queue() cleans up after itself on
942 * failure, but we need to clean up any previously
943 * initialised queues. Set num_queues to i so that
944 * earlier queues can be destroyed using the regular
945 * disconnect logic.
947 be->vif->num_queues = queue_index;
948 goto err;
951 queue->credit_bytes = credit_bytes;
952 queue->remaining_credit = credit_bytes;
953 queue->credit_usec = credit_usec;
955 err = connect_data_rings(be, queue);
956 if (err) {
957 /* connect_data_rings() cleans up after itself on
958 * failure, but we need to clean up after
959 * xenvif_init_queue() here, and also clean up any
960 * previously initialised queues.
962 xenvif_deinit_queue(queue);
963 be->vif->num_queues = queue_index;
964 goto err;
968 #ifdef CONFIG_DEBUG_FS
969 xenvif_debugfs_addif(be->vif);
970 #endif /* CONFIG_DEBUG_FS */
972 /* Initialisation completed, tell core driver the number of
973 * active queues.
975 rtnl_lock();
976 netif_set_real_num_tx_queues(be->vif->dev, requested_num_queues);
977 netif_set_real_num_rx_queues(be->vif->dev, requested_num_queues);
978 rtnl_unlock();
980 xenvif_carrier_on(be->vif);
982 unregister_hotplug_status_watch(be);
983 err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
984 hotplug_status_changed,
985 "%s/%s", dev->nodename, "hotplug-status");
986 if (!err)
987 be->have_hotplug_status_watch = 1;
989 netif_tx_wake_all_queues(be->vif->dev);
991 return;
993 err:
994 if (be->vif->num_queues > 0)
995 xenvif_disconnect_data(be->vif); /* Clean up existing queues */
996 vfree(be->vif->queues);
997 be->vif->queues = NULL;
998 be->vif->num_queues = 0;
999 xenvif_disconnect_ctrl(be->vif);
1000 return;
1004 static int connect_data_rings(struct backend_info *be,
1005 struct xenvif_queue *queue)
1007 struct xenbus_device *dev = be->dev;
1008 unsigned int num_queues = queue->vif->num_queues;
1009 unsigned long tx_ring_ref, rx_ring_ref;
1010 unsigned int tx_evtchn, rx_evtchn;
1011 int err;
1012 char *xspath;
1013 size_t xspathsize;
1014 const size_t xenstore_path_ext_size = 11; /* sufficient for "/queue-NNN" */
1016 /* If the frontend requested 1 queue, or we have fallen back
1017 * to single queue due to lack of frontend support for multi-
1018 * queue, expect the remaining XenStore keys in the toplevel
1019 * directory. Otherwise, expect them in a subdirectory called
1020 * queue-N.
1022 if (num_queues == 1) {
1023 xspath = kzalloc(strlen(dev->otherend) + 1, GFP_KERNEL);
1024 if (!xspath) {
1025 xenbus_dev_fatal(dev, -ENOMEM,
1026 "reading ring references");
1027 return -ENOMEM;
1029 strcpy(xspath, dev->otherend);
1030 } else {
1031 xspathsize = strlen(dev->otherend) + xenstore_path_ext_size;
1032 xspath = kzalloc(xspathsize, GFP_KERNEL);
1033 if (!xspath) {
1034 xenbus_dev_fatal(dev, -ENOMEM,
1035 "reading ring references");
1036 return -ENOMEM;
1038 snprintf(xspath, xspathsize, "%s/queue-%u", dev->otherend,
1039 queue->id);
1042 err = xenbus_gather(XBT_NIL, xspath,
1043 "tx-ring-ref", "%lu", &tx_ring_ref,
1044 "rx-ring-ref", "%lu", &rx_ring_ref, NULL);
1045 if (err) {
1046 xenbus_dev_fatal(dev, err,
1047 "reading %s/ring-ref",
1048 xspath);
1049 goto err;
1052 /* Try split event channels first, then single event channel. */
1053 err = xenbus_gather(XBT_NIL, xspath,
1054 "event-channel-tx", "%u", &tx_evtchn,
1055 "event-channel-rx", "%u", &rx_evtchn, NULL);
1056 if (err < 0) {
1057 err = xenbus_scanf(XBT_NIL, xspath,
1058 "event-channel", "%u", &tx_evtchn);
1059 if (err < 0) {
1060 xenbus_dev_fatal(dev, err,
1061 "reading %s/event-channel(-tx/rx)",
1062 xspath);
1063 goto err;
1065 rx_evtchn = tx_evtchn;
1068 /* Map the shared frame, irq etc. */
1069 err = xenvif_connect_data(queue, tx_ring_ref, rx_ring_ref,
1070 tx_evtchn, rx_evtchn);
1071 if (err) {
1072 xenbus_dev_fatal(dev, err,
1073 "mapping shared-frames %lu/%lu port tx %u rx %u",
1074 tx_ring_ref, rx_ring_ref,
1075 tx_evtchn, rx_evtchn);
1076 goto err;
1079 err = 0;
1080 err: /* Regular return falls through with err == 0 */
1081 kfree(xspath);
1082 return err;
1085 static int read_xenbus_vif_flags(struct backend_info *be)
1087 struct xenvif *vif = be->vif;
1088 struct xenbus_device *dev = be->dev;
1089 unsigned int rx_copy;
1090 int err, val;
1092 err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
1093 &rx_copy);
1094 if (err == -ENOENT) {
1095 err = 0;
1096 rx_copy = 0;
1098 if (err < 0) {
1099 xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
1100 dev->otherend);
1101 return err;
1103 if (!rx_copy)
1104 return -EOPNOTSUPP;
1106 if (xenbus_scanf(XBT_NIL, dev->otherend,
1107 "feature-rx-notify", "%d", &val) < 0)
1108 val = 0;
1109 if (!val) {
1110 /* - Reduce drain timeout to poll more frequently for
1111 * Rx requests.
1112 * - Disable Rx stall detection.
1114 be->vif->drain_timeout = msecs_to_jiffies(30);
1115 be->vif->stall_timeout = 0;
1118 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg",
1119 "%d", &val) < 0)
1120 val = 0;
1121 vif->can_sg = !!val;
1123 vif->gso_mask = 0;
1124 vif->gso_prefix_mask = 0;
1126 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4",
1127 "%d", &val) < 0)
1128 val = 0;
1129 if (val)
1130 vif->gso_mask |= GSO_BIT(TCPV4);
1132 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4-prefix",
1133 "%d", &val) < 0)
1134 val = 0;
1135 if (val)
1136 vif->gso_prefix_mask |= GSO_BIT(TCPV4);
1138 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6",
1139 "%d", &val) < 0)
1140 val = 0;
1141 if (val)
1142 vif->gso_mask |= GSO_BIT(TCPV6);
1144 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv6-prefix",
1145 "%d", &val) < 0)
1146 val = 0;
1147 if (val)
1148 vif->gso_prefix_mask |= GSO_BIT(TCPV6);
1150 if (vif->gso_mask & vif->gso_prefix_mask) {
1151 xenbus_dev_fatal(dev, err,
1152 "%s: gso and gso prefix flags are not "
1153 "mutually exclusive",
1154 dev->otherend);
1155 return -EOPNOTSUPP;
1158 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
1159 "%d", &val) < 0)
1160 val = 0;
1161 vif->ip_csum = !val;
1163 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-ipv6-csum-offload",
1164 "%d", &val) < 0)
1165 val = 0;
1166 vif->ipv6_csum = !!val;
1168 return 0;
1171 static const struct xenbus_device_id netback_ids[] = {
1172 { "vif" },
1173 { "" }
1176 static struct xenbus_driver netback_driver = {
1177 .ids = netback_ids,
1178 .probe = netback_probe,
1179 .remove = netback_remove,
1180 .uevent = netback_uevent,
1181 .otherend_changed = frontend_changed,
1184 int xenvif_xenbus_init(void)
1186 return xenbus_register_backend(&netback_driver);
1189 void xenvif_xenbus_fini(void)
1191 return xenbus_unregister_driver(&netback_driver);