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, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 struct xenbus_device *dev;
27 enum xenbus_state frontend_state;
28 struct xenbus_watch hotplug_status_watch;
29 u8 have_hotplug_status_watch:1;
32 static int connect_rings(struct backend_info *);
33 static void connect(struct backend_info *);
34 static void backend_create_xenvif(struct backend_info *be);
35 static void unregister_hotplug_status_watch(struct backend_info *be);
37 static int netback_remove(struct xenbus_device *dev)
39 struct backend_info *be = dev_get_drvdata(&dev->dev);
41 unregister_hotplug_status_watch(be);
43 kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
44 xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
45 xenvif_disconnect(be->vif);
49 dev_set_drvdata(&dev->dev, NULL);
55 * Entry point to this code when a new device is created. Allocate the basic
56 * structures and switch to InitWait.
58 static int netback_probe(struct xenbus_device *dev,
59 const struct xenbus_device_id *id)
62 struct xenbus_transaction xbt;
65 struct backend_info *be = kzalloc(sizeof(struct backend_info),
68 xenbus_dev_fatal(dev, -ENOMEM,
69 "allocating backend structure");
74 dev_set_drvdata(&dev->dev, be);
79 err = xenbus_transaction_start(&xbt);
81 xenbus_dev_fatal(dev, err, "starting transaction");
85 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
87 message = "writing feature-sg";
88 goto abort_transaction;
91 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
94 message = "writing feature-gso-tcpv4";
95 goto abort_transaction;
98 /* We support rx-copy path. */
99 err = xenbus_printf(xbt, dev->nodename,
100 "feature-rx-copy", "%d", 1);
102 message = "writing feature-rx-copy";
103 goto abort_transaction;
107 * We don't support rx-flip path (except old guests who don't
108 * grok this feature flag).
110 err = xenbus_printf(xbt, dev->nodename,
111 "feature-rx-flip", "%d", 0);
113 message = "writing feature-rx-flip";
114 goto abort_transaction;
117 err = xenbus_transaction_end(xbt, 0);
118 } while (err == -EAGAIN);
121 xenbus_dev_fatal(dev, err, "completing transaction");
126 * Split event channels support, this is optional so it is not
127 * put inside the above loop.
129 err = xenbus_printf(XBT_NIL, dev->nodename,
130 "feature-split-event-channels",
131 "%u", separate_tx_rx_irq);
133 pr_debug("Error writing feature-split-event-channels\n");
135 err = xenbus_switch_state(dev, XenbusStateInitWait);
139 /* This kicks hotplug scripts, so do it immediately. */
140 backend_create_xenvif(be);
145 xenbus_transaction_end(xbt, 1);
146 xenbus_dev_fatal(dev, err, "%s", message);
148 pr_debug("failed\n");
155 * Handle the creation of the hotplug script environment. We add the script
156 * and vif variables to the environment, for the benefit of the vif-* hotplug
159 static int netback_uevent(struct xenbus_device *xdev,
160 struct kobj_uevent_env *env)
162 struct backend_info *be = dev_get_drvdata(&xdev->dev);
165 val = xenbus_read(XBT_NIL, xdev->nodename, "script", NULL);
167 int err = PTR_ERR(val);
168 xenbus_dev_fatal(xdev, err, "reading script");
171 if (add_uevent_var(env, "script=%s", val)) {
181 return add_uevent_var(env, "vif=%s", be->vif->dev->name);
185 static void backend_create_xenvif(struct backend_info *be)
189 struct xenbus_device *dev = be->dev;
194 err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
196 xenbus_dev_fatal(dev, err, "reading handle");
200 be->vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
201 if (IS_ERR(be->vif)) {
202 err = PTR_ERR(be->vif);
204 xenbus_dev_fatal(dev, err, "creating interface");
208 kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
212 static void disconnect_backend(struct xenbus_device *dev)
214 struct backend_info *be = dev_get_drvdata(&dev->dev);
217 xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
218 xenvif_disconnect(be->vif);
224 * Callback received when the frontend's state changes.
226 static void frontend_changed(struct xenbus_device *dev,
227 enum xenbus_state frontend_state)
229 struct backend_info *be = dev_get_drvdata(&dev->dev);
231 pr_debug("frontend state %s\n", xenbus_strstate(frontend_state));
233 be->frontend_state = frontend_state;
235 switch (frontend_state) {
236 case XenbusStateInitialising:
237 if (dev->state == XenbusStateClosed) {
238 pr_info("%s: prepare for reconnect\n", dev->nodename);
239 xenbus_switch_state(dev, XenbusStateInitWait);
243 case XenbusStateInitialised:
246 case XenbusStateConnected:
247 if (dev->state == XenbusStateConnected)
249 backend_create_xenvif(be);
254 case XenbusStateClosing:
256 kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
257 disconnect_backend(dev);
258 xenbus_switch_state(dev, XenbusStateClosing);
261 case XenbusStateClosed:
262 xenbus_switch_state(dev, XenbusStateClosed);
263 if (xenbus_dev_is_online(dev))
265 /* fall through if not online */
266 case XenbusStateUnknown:
267 device_unregister(&dev->dev);
271 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
278 static void xen_net_read_rate(struct xenbus_device *dev,
279 unsigned long *bytes, unsigned long *usec)
285 /* Default to unlimited bandwidth. */
289 ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
294 b = simple_strtoul(s, &e, 10);
295 if ((s == e) || (*e != ','))
299 u = simple_strtoul(s, &e, 10);
300 if ((s == e) || (*e != '\0'))
310 pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
314 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
316 char *s, *e, *macstr;
319 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
321 return PTR_ERR(macstr);
323 for (i = 0; i < ETH_ALEN; i++) {
324 mac[i] = simple_strtoul(s, &e, 16);
325 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
336 static void unregister_hotplug_status_watch(struct backend_info *be)
338 if (be->have_hotplug_status_watch) {
339 unregister_xenbus_watch(&be->hotplug_status_watch);
340 kfree(be->hotplug_status_watch.node);
342 be->have_hotplug_status_watch = 0;
345 static void hotplug_status_changed(struct xenbus_watch *watch,
347 unsigned int vec_size)
349 struct backend_info *be = container_of(watch,
351 hotplug_status_watch);
355 str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
358 if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
359 xenbus_switch_state(be->dev, XenbusStateConnected);
360 /* Not interested in this watch anymore. */
361 unregister_hotplug_status_watch(be);
366 static void connect(struct backend_info *be)
369 struct xenbus_device *dev = be->dev;
371 err = connect_rings(be);
375 err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
377 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
381 xen_net_read_rate(dev, &be->vif->credit_bytes,
382 &be->vif->credit_usec);
383 be->vif->remaining_credit = be->vif->credit_bytes;
385 unregister_hotplug_status_watch(be);
386 err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
387 hotplug_status_changed,
388 "%s/%s", dev->nodename, "hotplug-status");
390 /* Switch now, since we can't do a watch. */
391 xenbus_switch_state(dev, XenbusStateConnected);
393 be->have_hotplug_status_watch = 1;
396 netif_wake_queue(be->vif->dev);
400 static int connect_rings(struct backend_info *be)
402 struct xenvif *vif = be->vif;
403 struct xenbus_device *dev = be->dev;
404 unsigned long tx_ring_ref, rx_ring_ref;
405 unsigned int tx_evtchn, rx_evtchn, rx_copy;
409 err = xenbus_gather(XBT_NIL, dev->otherend,
410 "tx-ring-ref", "%lu", &tx_ring_ref,
411 "rx-ring-ref", "%lu", &rx_ring_ref, NULL);
413 xenbus_dev_fatal(dev, err,
414 "reading %s/ring-ref",
419 /* Try split event channels first, then single event channel. */
420 err = xenbus_gather(XBT_NIL, dev->otherend,
421 "event-channel-tx", "%u", &tx_evtchn,
422 "event-channel-rx", "%u", &rx_evtchn, NULL);
424 err = xenbus_scanf(XBT_NIL, dev->otherend,
425 "event-channel", "%u", &tx_evtchn);
427 xenbus_dev_fatal(dev, err,
428 "reading %s/event-channel(-tx/rx)",
432 rx_evtchn = tx_evtchn;
435 err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
437 if (err == -ENOENT) {
442 xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
449 if (vif->dev->tx_queue_len != 0) {
450 if (xenbus_scanf(XBT_NIL, dev->otherend,
451 "feature-rx-notify", "%d", &val) < 0)
456 /* Must be non-zero for pfifo_fast to work. */
457 vif->dev->tx_queue_len = 1;
460 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg",
465 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4",
470 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4-prefix",
473 vif->gso_prefix = !!val;
475 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
480 /* Map the shared frame, irq etc. */
481 err = xenvif_connect(vif, tx_ring_ref, rx_ring_ref,
482 tx_evtchn, rx_evtchn);
484 xenbus_dev_fatal(dev, err,
485 "mapping shared-frames %lu/%lu port tx %u rx %u",
486 tx_ring_ref, rx_ring_ref,
487 tx_evtchn, rx_evtchn);
494 /* ** Driver Registration ** */
497 static const struct xenbus_device_id netback_ids[] = {
503 static DEFINE_XENBUS_DRIVER(netback, ,
504 .probe = netback_probe,
505 .remove = netback_remove,
506 .uevent = netback_uevent,
507 .otherend_changed = frontend_changed,
510 int xenvif_xenbus_init(void)
512 return xenbus_register_backend(&netback_driver);
515 void xenvif_xenbus_fini(void)
517 return xenbus_unregister_driver(&netback_driver);