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;
28 /* This is the state that will be reflected in xenstore when any
29 * active hotplug script completes.
31 enum xenbus_state state;
33 enum xenbus_state frontend_state;
34 struct xenbus_watch hotplug_status_watch;
35 u8 have_hotplug_status_watch:1;
38 static int connect_rings(struct backend_info *);
39 static void connect(struct backend_info *);
40 static void backend_create_xenvif(struct backend_info *be);
41 static void unregister_hotplug_status_watch(struct backend_info *be);
42 static void set_backend_state(struct backend_info *be,
43 enum xenbus_state state);
45 static int netback_remove(struct xenbus_device *dev)
47 struct backend_info *be = dev_get_drvdata(&dev->dev);
49 set_backend_state(be, XenbusStateClosed);
51 unregister_hotplug_status_watch(be);
53 kobject_uevent(&dev->dev.kobj, KOBJ_OFFLINE);
54 xenbus_rm(XBT_NIL, dev->nodename, "hotplug-status");
59 dev_set_drvdata(&dev->dev, NULL);
65 * Entry point to this code when a new device is created. Allocate the basic
66 * structures and switch to InitWait.
68 static int netback_probe(struct xenbus_device *dev,
69 const struct xenbus_device_id *id)
72 struct xenbus_transaction xbt;
75 struct backend_info *be = kzalloc(sizeof(struct backend_info),
78 xenbus_dev_fatal(dev, -ENOMEM,
79 "allocating backend structure");
84 dev_set_drvdata(&dev->dev, be);
89 err = xenbus_transaction_start(&xbt);
91 xenbus_dev_fatal(dev, err, "starting transaction");
95 err = xenbus_printf(xbt, dev->nodename, "feature-sg", "%d", sg);
97 message = "writing feature-sg";
98 goto abort_transaction;
101 err = xenbus_printf(xbt, dev->nodename, "feature-gso-tcpv4",
104 message = "writing feature-gso-tcpv4";
105 goto abort_transaction;
108 /* We support rx-copy path. */
109 err = xenbus_printf(xbt, dev->nodename,
110 "feature-rx-copy", "%d", 1);
112 message = "writing feature-rx-copy";
113 goto abort_transaction;
117 * We don't support rx-flip path (except old guests who don't
118 * grok this feature flag).
120 err = xenbus_printf(xbt, dev->nodename,
121 "feature-rx-flip", "%d", 0);
123 message = "writing feature-rx-flip";
124 goto abort_transaction;
127 err = xenbus_transaction_end(xbt, 0);
128 } while (err == -EAGAIN);
131 xenbus_dev_fatal(dev, err, "completing transaction");
136 * Split event channels support, this is optional so it is not
137 * put inside the above loop.
139 err = xenbus_printf(XBT_NIL, dev->nodename,
140 "feature-split-event-channels",
141 "%u", separate_tx_rx_irq);
143 pr_debug("Error writing feature-split-event-channels\n");
145 err = xenbus_switch_state(dev, XenbusStateInitWait);
149 be->state = XenbusStateInitWait;
151 /* This kicks hotplug scripts, so do it immediately. */
152 backend_create_xenvif(be);
157 xenbus_transaction_end(xbt, 1);
158 xenbus_dev_fatal(dev, err, "%s", message);
160 pr_debug("failed\n");
167 * Handle the creation of the hotplug script environment. We add the script
168 * and vif variables to the environment, for the benefit of the vif-* hotplug
171 static int netback_uevent(struct xenbus_device *xdev,
172 struct kobj_uevent_env *env)
174 struct backend_info *be = dev_get_drvdata(&xdev->dev);
177 val = xenbus_read(XBT_NIL, xdev->nodename, "script", NULL);
179 int err = PTR_ERR(val);
180 xenbus_dev_fatal(xdev, err, "reading script");
183 if (add_uevent_var(env, "script=%s", val)) {
193 return add_uevent_var(env, "vif=%s", be->vif->dev->name);
197 static void backend_create_xenvif(struct backend_info *be)
201 struct xenbus_device *dev = be->dev;
206 err = xenbus_scanf(XBT_NIL, dev->nodename, "handle", "%li", &handle);
208 xenbus_dev_fatal(dev, err, "reading handle");
212 be->vif = xenvif_alloc(&dev->dev, dev->otherend_id, handle);
213 if (IS_ERR(be->vif)) {
214 err = PTR_ERR(be->vif);
216 xenbus_dev_fatal(dev, err, "creating interface");
220 kobject_uevent(&dev->dev.kobj, KOBJ_ONLINE);
223 static void backend_disconnect(struct backend_info *be)
226 xenvif_disconnect(be->vif);
229 static void backend_connect(struct backend_info *be)
235 static inline void backend_switch_state(struct backend_info *be,
236 enum xenbus_state state)
238 struct xenbus_device *dev = be->dev;
240 pr_debug("%s -> %s\n", dev->nodename, xenbus_strstate(state));
243 /* If we are waiting for a hotplug script then defer the
244 * actual xenbus state change.
246 if (!be->have_hotplug_status_watch)
247 xenbus_switch_state(dev, state);
250 /* Handle backend state transitions:
252 * The backend state starts in InitWait and the following transitions are
255 * InitWait -> Connected
267 * The state argument specifies the eventual state of the backend and the
268 * function transitions to that state via the shortest path.
270 static void set_backend_state(struct backend_info *be,
271 enum xenbus_state state)
273 while (be->state != state) {
275 case XenbusStateClosed:
277 case XenbusStateInitWait:
278 case XenbusStateConnected:
279 pr_info("%s: prepare for reconnect\n",
281 backend_switch_state(be, XenbusStateInitWait);
283 case XenbusStateClosing:
284 backend_switch_state(be, XenbusStateClosing);
290 case XenbusStateInitWait:
292 case XenbusStateConnected:
294 backend_switch_state(be, XenbusStateConnected);
296 case XenbusStateClosing:
297 case XenbusStateClosed:
298 backend_switch_state(be, XenbusStateClosing);
304 case XenbusStateConnected:
306 case XenbusStateInitWait:
307 case XenbusStateClosing:
308 case XenbusStateClosed:
309 backend_disconnect(be);
310 backend_switch_state(be, XenbusStateClosing);
316 case XenbusStateClosing:
318 case XenbusStateInitWait:
319 case XenbusStateConnected:
320 case XenbusStateClosed:
321 backend_switch_state(be, XenbusStateClosed);
334 * Callback received when the frontend's state changes.
336 static void frontend_changed(struct xenbus_device *dev,
337 enum xenbus_state frontend_state)
339 struct backend_info *be = dev_get_drvdata(&dev->dev);
341 pr_debug("%s -> %s\n", dev->otherend, xenbus_strstate(frontend_state));
343 be->frontend_state = frontend_state;
345 switch (frontend_state) {
346 case XenbusStateInitialising:
347 set_backend_state(be, XenbusStateInitWait);
350 case XenbusStateInitialised:
353 case XenbusStateConnected:
354 set_backend_state(be, XenbusStateConnected);
357 case XenbusStateClosing:
358 set_backend_state(be, XenbusStateClosing);
361 case XenbusStateClosed:
362 set_backend_state(be, XenbusStateClosed);
363 if (xenbus_dev_is_online(dev))
365 /* fall through if not online */
366 case XenbusStateUnknown:
367 set_backend_state(be, XenbusStateClosed);
368 device_unregister(&dev->dev);
372 xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
379 static void xen_net_read_rate(struct xenbus_device *dev,
380 unsigned long *bytes, unsigned long *usec)
386 /* Default to unlimited bandwidth. */
390 ratestr = xenbus_read(XBT_NIL, dev->nodename, "rate", NULL);
395 b = simple_strtoul(s, &e, 10);
396 if ((s == e) || (*e != ','))
400 u = simple_strtoul(s, &e, 10);
401 if ((s == e) || (*e != '\0'))
411 pr_warn("Failed to parse network rate limit. Traffic unlimited.\n");
415 static int xen_net_read_mac(struct xenbus_device *dev, u8 mac[])
417 char *s, *e, *macstr;
420 macstr = s = xenbus_read(XBT_NIL, dev->nodename, "mac", NULL);
422 return PTR_ERR(macstr);
424 for (i = 0; i < ETH_ALEN; i++) {
425 mac[i] = simple_strtoul(s, &e, 16);
426 if ((s == e) || (*e != ((i == ETH_ALEN-1) ? '\0' : ':'))) {
437 static void unregister_hotplug_status_watch(struct backend_info *be)
439 if (be->have_hotplug_status_watch) {
440 unregister_xenbus_watch(&be->hotplug_status_watch);
441 kfree(be->hotplug_status_watch.node);
443 be->have_hotplug_status_watch = 0;
446 static void hotplug_status_changed(struct xenbus_watch *watch,
448 unsigned int vec_size)
450 struct backend_info *be = container_of(watch,
452 hotplug_status_watch);
456 str = xenbus_read(XBT_NIL, be->dev->nodename, "hotplug-status", &len);
459 if (len == sizeof("connected")-1 && !memcmp(str, "connected", len)) {
460 /* Complete any pending state change */
461 xenbus_switch_state(be->dev, be->state);
463 /* Not interested in this watch anymore. */
464 unregister_hotplug_status_watch(be);
469 static void connect(struct backend_info *be)
472 struct xenbus_device *dev = be->dev;
474 err = connect_rings(be);
478 err = xen_net_read_mac(dev, be->vif->fe_dev_addr);
480 xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
484 xen_net_read_rate(dev, &be->vif->credit_bytes,
485 &be->vif->credit_usec);
486 be->vif->remaining_credit = be->vif->credit_bytes;
488 unregister_hotplug_status_watch(be);
489 err = xenbus_watch_pathfmt(dev, &be->hotplug_status_watch,
490 hotplug_status_changed,
491 "%s/%s", dev->nodename, "hotplug-status");
493 be->have_hotplug_status_watch = 1;
495 netif_wake_queue(be->vif->dev);
499 static int connect_rings(struct backend_info *be)
501 struct xenvif *vif = be->vif;
502 struct xenbus_device *dev = be->dev;
503 unsigned long tx_ring_ref, rx_ring_ref;
504 unsigned int tx_evtchn, rx_evtchn, rx_copy;
508 err = xenbus_gather(XBT_NIL, dev->otherend,
509 "tx-ring-ref", "%lu", &tx_ring_ref,
510 "rx-ring-ref", "%lu", &rx_ring_ref, NULL);
512 xenbus_dev_fatal(dev, err,
513 "reading %s/ring-ref",
518 /* Try split event channels first, then single event channel. */
519 err = xenbus_gather(XBT_NIL, dev->otherend,
520 "event-channel-tx", "%u", &tx_evtchn,
521 "event-channel-rx", "%u", &rx_evtchn, NULL);
523 err = xenbus_scanf(XBT_NIL, dev->otherend,
524 "event-channel", "%u", &tx_evtchn);
526 xenbus_dev_fatal(dev, err,
527 "reading %s/event-channel(-tx/rx)",
531 rx_evtchn = tx_evtchn;
534 err = xenbus_scanf(XBT_NIL, dev->otherend, "request-rx-copy", "%u",
536 if (err == -ENOENT) {
541 xenbus_dev_fatal(dev, err, "reading %s/request-rx-copy",
548 if (vif->dev->tx_queue_len != 0) {
549 if (xenbus_scanf(XBT_NIL, dev->otherend,
550 "feature-rx-notify", "%d", &val) < 0)
555 /* Must be non-zero for pfifo_fast to work. */
556 vif->dev->tx_queue_len = 1;
559 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-sg",
564 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4",
569 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-gso-tcpv4-prefix",
572 vif->gso_prefix = !!val;
574 if (xenbus_scanf(XBT_NIL, dev->otherend, "feature-no-csum-offload",
579 /* Map the shared frame, irq etc. */
580 err = xenvif_connect(vif, tx_ring_ref, rx_ring_ref,
581 tx_evtchn, rx_evtchn);
583 xenbus_dev_fatal(dev, err,
584 "mapping shared-frames %lu/%lu port tx %u rx %u",
585 tx_ring_ref, rx_ring_ref,
586 tx_evtchn, rx_evtchn);
593 /* ** Driver Registration ** */
596 static const struct xenbus_device_id netback_ids[] = {
602 static DEFINE_XENBUS_DRIVER(netback, ,
603 .probe = netback_probe,
604 .remove = netback_remove,
605 .uevent = netback_uevent,
606 .otherend_changed = frontend_changed,
609 int xenvif_xenbus_init(void)
611 return xenbus_register_backend(&netback_driver);
614 void xenvif_xenbus_fini(void)
616 return xenbus_unregister_driver(&netback_driver);