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4bac07c9 JF |
1 | /****************************************************************************** |
2 | * Talks to Xen Store to figure out what devices we have. | |
3 | * | |
4 | * Copyright (C) 2005 Rusty Russell, IBM Corporation | |
5 | * Copyright (C) 2005 Mike Wray, Hewlett-Packard | |
6 | * Copyright (C) 2005, 2006 XenSource Ltd | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or | |
9 | * modify it under the terms of the GNU General Public License version 2 | |
10 | * as published by the Free Software Foundation; or, when distributed | |
11 | * separately from the Linux kernel or incorporated into other | |
12 | * software packages, subject to the following license: | |
13 | * | |
14 | * Permission is hereby granted, free of charge, to any person obtaining a copy | |
15 | * of this source file (the "Software"), to deal in the Software without | |
16 | * restriction, including without limitation the rights to use, copy, modify, | |
17 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, | |
18 | * and to permit persons to whom the Software is furnished to do so, subject to | |
19 | * the following conditions: | |
20 | * | |
21 | * The above copyright notice and this permission notice shall be included in | |
22 | * all copies or substantial portions of the Software. | |
23 | * | |
24 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | |
25 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | |
26 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | |
27 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | |
28 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | |
29 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | |
30 | * IN THE SOFTWARE. | |
31 | */ | |
32 | ||
33 | #define DPRINTK(fmt, args...) \ | |
34 | pr_debug("xenbus_probe (%s:%d) " fmt ".\n", \ | |
35 | __func__, __LINE__, ##args) | |
36 | ||
37 | #include <linux/kernel.h> | |
38 | #include <linux/err.h> | |
39 | #include <linux/string.h> | |
40 | #include <linux/ctype.h> | |
41 | #include <linux/fcntl.h> | |
42 | #include <linux/mm.h> | |
1107ba88 | 43 | #include <linux/proc_fs.h> |
4bac07c9 JF |
44 | #include <linux/notifier.h> |
45 | #include <linux/kthread.h> | |
46 | #include <linux/mutex.h> | |
47 | #include <linux/io.h> | |
5a0e3ad6 | 48 | #include <linux/slab.h> |
4bac07c9 JF |
49 | |
50 | #include <asm/page.h> | |
51 | #include <asm/pgtable.h> | |
52 | #include <asm/xen/hypervisor.h> | |
1ccbf534 JF |
53 | |
54 | #include <xen/xen.h> | |
4bac07c9 JF |
55 | #include <xen/xenbus.h> |
56 | #include <xen/events.h> | |
57 | #include <xen/page.h> | |
58 | ||
c1c5413a | 59 | #include <xen/platform_pci.h> |
bee6ab53 SY |
60 | #include <xen/hvm.h> |
61 | ||
4bac07c9 JF |
62 | #include "xenbus_comms.h" |
63 | #include "xenbus_probe.h" | |
64 | ||
1107ba88 | 65 | |
4bac07c9 | 66 | int xen_store_evtchn; |
1107ba88 AZ |
67 | EXPORT_SYMBOL(xen_store_evtchn); |
68 | ||
4bac07c9 JF |
69 | struct xenstore_domain_interface *xen_store_interface; |
70 | static unsigned long xen_store_mfn; | |
71 | ||
72 | static BLOCKING_NOTIFIER_HEAD(xenstore_chain); | |
73 | ||
74 | static void wait_for_devices(struct xenbus_driver *xendrv); | |
75 | ||
76 | static int xenbus_probe_frontend(const char *type, const char *name); | |
77 | ||
78 | static void xenbus_dev_shutdown(struct device *_dev); | |
79 | ||
de5b31bd IC |
80 | static int xenbus_dev_suspend(struct device *dev, pm_message_t state); |
81 | static int xenbus_dev_resume(struct device *dev); | |
82 | ||
4bac07c9 JF |
83 | /* If something in array of ids matches this device, return it. */ |
84 | static const struct xenbus_device_id * | |
85 | match_device(const struct xenbus_device_id *arr, struct xenbus_device *dev) | |
86 | { | |
87 | for (; *arr->devicetype != '\0'; arr++) { | |
88 | if (!strcmp(arr->devicetype, dev->devicetype)) | |
89 | return arr; | |
90 | } | |
91 | return NULL; | |
92 | } | |
93 | ||
94 | int xenbus_match(struct device *_dev, struct device_driver *_drv) | |
95 | { | |
96 | struct xenbus_driver *drv = to_xenbus_driver(_drv); | |
97 | ||
98 | if (!drv->ids) | |
99 | return 0; | |
100 | ||
101 | return match_device(drv->ids, to_xenbus_device(_dev)) != NULL; | |
102 | } | |
103 | ||
d2f0c52b MM |
104 | static int xenbus_uevent(struct device *_dev, struct kobj_uevent_env *env) |
105 | { | |
106 | struct xenbus_device *dev = to_xenbus_device(_dev); | |
107 | ||
108 | if (add_uevent_var(env, "MODALIAS=xen:%s", dev->devicetype)) | |
109 | return -ENOMEM; | |
110 | ||
111 | return 0; | |
112 | } | |
113 | ||
4bac07c9 | 114 | /* device/<type>/<id> => <type>-<id> */ |
2a678cc5 | 115 | static int frontend_bus_id(char bus_id[XEN_BUS_ID_SIZE], const char *nodename) |
4bac07c9 JF |
116 | { |
117 | nodename = strchr(nodename, '/'); | |
2a678cc5 | 118 | if (!nodename || strlen(nodename + 1) >= XEN_BUS_ID_SIZE) { |
4bac07c9 JF |
119 | printk(KERN_WARNING "XENBUS: bad frontend %s\n", nodename); |
120 | return -EINVAL; | |
121 | } | |
122 | ||
2a678cc5 | 123 | strlcpy(bus_id, nodename + 1, XEN_BUS_ID_SIZE); |
4bac07c9 JF |
124 | if (!strchr(bus_id, '/')) { |
125 | printk(KERN_WARNING "XENBUS: bus_id %s no slash\n", bus_id); | |
126 | return -EINVAL; | |
127 | } | |
128 | *strchr(bus_id, '/') = '-'; | |
129 | return 0; | |
130 | } | |
131 | ||
132 | ||
133 | static void free_otherend_details(struct xenbus_device *dev) | |
134 | { | |
135 | kfree(dev->otherend); | |
136 | dev->otherend = NULL; | |
137 | } | |
138 | ||
139 | ||
140 | static void free_otherend_watch(struct xenbus_device *dev) | |
141 | { | |
142 | if (dev->otherend_watch.node) { | |
143 | unregister_xenbus_watch(&dev->otherend_watch); | |
144 | kfree(dev->otherend_watch.node); | |
145 | dev->otherend_watch.node = NULL; | |
146 | } | |
147 | } | |
148 | ||
149 | ||
150 | int read_otherend_details(struct xenbus_device *xendev, | |
151 | char *id_node, char *path_node) | |
152 | { | |
153 | int err = xenbus_gather(XBT_NIL, xendev->nodename, | |
154 | id_node, "%i", &xendev->otherend_id, | |
155 | path_node, NULL, &xendev->otherend, | |
156 | NULL); | |
157 | if (err) { | |
158 | xenbus_dev_fatal(xendev, err, | |
159 | "reading other end details from %s", | |
160 | xendev->nodename); | |
161 | return err; | |
162 | } | |
163 | if (strlen(xendev->otherend) == 0 || | |
164 | !xenbus_exists(XBT_NIL, xendev->otherend, "")) { | |
165 | xenbus_dev_fatal(xendev, -ENOENT, | |
166 | "unable to read other end from %s. " | |
167 | "missing or inaccessible.", | |
168 | xendev->nodename); | |
169 | free_otherend_details(xendev); | |
170 | return -ENOENT; | |
171 | } | |
172 | ||
173 | return 0; | |
174 | } | |
175 | ||
176 | ||
177 | static int read_backend_details(struct xenbus_device *xendev) | |
178 | { | |
179 | return read_otherend_details(xendev, "backend-id", "backend"); | |
180 | } | |
181 | ||
1107ba88 AZ |
182 | static struct device_attribute xenbus_dev_attrs[] = { |
183 | __ATTR_NULL | |
184 | }; | |
4bac07c9 JF |
185 | |
186 | /* Bus type for frontend drivers. */ | |
187 | static struct xen_bus_type xenbus_frontend = { | |
188 | .root = "device", | |
189 | .levels = 2, /* device/type/<id> */ | |
190 | .get_bus_id = frontend_bus_id, | |
191 | .probe = xenbus_probe_frontend, | |
192 | .bus = { | |
1107ba88 AZ |
193 | .name = "xen", |
194 | .match = xenbus_match, | |
195 | .uevent = xenbus_uevent, | |
196 | .probe = xenbus_dev_probe, | |
197 | .remove = xenbus_dev_remove, | |
198 | .shutdown = xenbus_dev_shutdown, | |
199 | .dev_attrs = xenbus_dev_attrs, | |
de5b31bd IC |
200 | |
201 | .suspend = xenbus_dev_suspend, | |
202 | .resume = xenbus_dev_resume, | |
4bac07c9 JF |
203 | }, |
204 | }; | |
205 | ||
206 | static void otherend_changed(struct xenbus_watch *watch, | |
207 | const char **vec, unsigned int len) | |
208 | { | |
209 | struct xenbus_device *dev = | |
210 | container_of(watch, struct xenbus_device, otherend_watch); | |
211 | struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver); | |
212 | enum xenbus_state state; | |
213 | ||
214 | /* Protect us against watches firing on old details when the otherend | |
215 | details change, say immediately after a resume. */ | |
216 | if (!dev->otherend || | |
217 | strncmp(dev->otherend, vec[XS_WATCH_PATH], | |
218 | strlen(dev->otherend))) { | |
898eb71c JP |
219 | dev_dbg(&dev->dev, "Ignoring watch at %s\n", |
220 | vec[XS_WATCH_PATH]); | |
4bac07c9 JF |
221 | return; |
222 | } | |
223 | ||
224 | state = xenbus_read_driver_state(dev->otherend); | |
225 | ||
898eb71c | 226 | dev_dbg(&dev->dev, "state is %d, (%s), %s, %s\n", |
4bac07c9 JF |
227 | state, xenbus_strstate(state), dev->otherend_watch.node, |
228 | vec[XS_WATCH_PATH]); | |
229 | ||
230 | /* | |
231 | * Ignore xenbus transitions during shutdown. This prevents us doing | |
232 | * work that can fail e.g., when the rootfs is gone. | |
233 | */ | |
234 | if (system_state > SYSTEM_RUNNING) { | |
235 | struct xen_bus_type *bus = bus; | |
236 | bus = container_of(dev->dev.bus, struct xen_bus_type, bus); | |
237 | /* If we're frontend, drive the state machine to Closed. */ | |
238 | /* This should cause the backend to release our resources. */ | |
239 | if ((bus == &xenbus_frontend) && (state == XenbusStateClosing)) | |
240 | xenbus_frontend_closed(dev); | |
241 | return; | |
242 | } | |
243 | ||
244 | if (drv->otherend_changed) | |
245 | drv->otherend_changed(dev, state); | |
246 | } | |
247 | ||
248 | ||
249 | static int talk_to_otherend(struct xenbus_device *dev) | |
250 | { | |
251 | struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver); | |
252 | ||
253 | free_otherend_watch(dev); | |
254 | free_otherend_details(dev); | |
255 | ||
256 | return drv->read_otherend_details(dev); | |
257 | } | |
258 | ||
259 | ||
260 | static int watch_otherend(struct xenbus_device *dev) | |
261 | { | |
262 | return xenbus_watch_pathfmt(dev, &dev->otherend_watch, otherend_changed, | |
263 | "%s/%s", dev->otherend, "state"); | |
264 | } | |
265 | ||
266 | ||
267 | int xenbus_dev_probe(struct device *_dev) | |
268 | { | |
269 | struct xenbus_device *dev = to_xenbus_device(_dev); | |
270 | struct xenbus_driver *drv = to_xenbus_driver(_dev->driver); | |
271 | const struct xenbus_device_id *id; | |
272 | int err; | |
273 | ||
274 | DPRINTK("%s", dev->nodename); | |
275 | ||
276 | if (!drv->probe) { | |
277 | err = -ENODEV; | |
278 | goto fail; | |
279 | } | |
280 | ||
281 | id = match_device(drv->ids, dev); | |
282 | if (!id) { | |
283 | err = -ENODEV; | |
284 | goto fail; | |
285 | } | |
286 | ||
287 | err = talk_to_otherend(dev); | |
288 | if (err) { | |
289 | dev_warn(&dev->dev, "talk_to_otherend on %s failed.\n", | |
290 | dev->nodename); | |
291 | return err; | |
292 | } | |
293 | ||
294 | err = drv->probe(dev, id); | |
295 | if (err) | |
296 | goto fail; | |
297 | ||
298 | err = watch_otherend(dev); | |
299 | if (err) { | |
300 | dev_warn(&dev->dev, "watch_otherend on %s failed.\n", | |
301 | dev->nodename); | |
302 | return err; | |
303 | } | |
304 | ||
305 | return 0; | |
306 | fail: | |
307 | xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename); | |
308 | xenbus_switch_state(dev, XenbusStateClosed); | |
309 | return -ENODEV; | |
310 | } | |
311 | ||
312 | int xenbus_dev_remove(struct device *_dev) | |
313 | { | |
314 | struct xenbus_device *dev = to_xenbus_device(_dev); | |
315 | struct xenbus_driver *drv = to_xenbus_driver(_dev->driver); | |
316 | ||
317 | DPRINTK("%s", dev->nodename); | |
318 | ||
319 | free_otherend_watch(dev); | |
320 | free_otherend_details(dev); | |
321 | ||
322 | if (drv->remove) | |
323 | drv->remove(dev); | |
324 | ||
325 | xenbus_switch_state(dev, XenbusStateClosed); | |
326 | return 0; | |
327 | } | |
328 | ||
329 | static void xenbus_dev_shutdown(struct device *_dev) | |
330 | { | |
331 | struct xenbus_device *dev = to_xenbus_device(_dev); | |
332 | unsigned long timeout = 5*HZ; | |
333 | ||
334 | DPRINTK("%s", dev->nodename); | |
335 | ||
336 | get_device(&dev->dev); | |
337 | if (dev->state != XenbusStateConnected) { | |
338 | printk(KERN_INFO "%s: %s: %s != Connected, skipping\n", __func__, | |
339 | dev->nodename, xenbus_strstate(dev->state)); | |
340 | goto out; | |
341 | } | |
342 | xenbus_switch_state(dev, XenbusStateClosing); | |
343 | timeout = wait_for_completion_timeout(&dev->down, timeout); | |
344 | if (!timeout) | |
345 | printk(KERN_INFO "%s: %s timeout closing device\n", | |
346 | __func__, dev->nodename); | |
347 | out: | |
348 | put_device(&dev->dev); | |
349 | } | |
350 | ||
351 | int xenbus_register_driver_common(struct xenbus_driver *drv, | |
352 | struct xen_bus_type *bus, | |
353 | struct module *owner, | |
354 | const char *mod_name) | |
355 | { | |
356 | drv->driver.name = drv->name; | |
357 | drv->driver.bus = &bus->bus; | |
358 | drv->driver.owner = owner; | |
359 | drv->driver.mod_name = mod_name; | |
360 | ||
361 | return driver_register(&drv->driver); | |
362 | } | |
363 | ||
364 | int __xenbus_register_frontend(struct xenbus_driver *drv, | |
365 | struct module *owner, const char *mod_name) | |
366 | { | |
367 | int ret; | |
368 | ||
369 | drv->read_otherend_details = read_backend_details; | |
370 | ||
371 | ret = xenbus_register_driver_common(drv, &xenbus_frontend, | |
372 | owner, mod_name); | |
373 | if (ret) | |
374 | return ret; | |
375 | ||
376 | /* If this driver is loaded as a module wait for devices to attach. */ | |
377 | wait_for_devices(drv); | |
378 | ||
379 | return 0; | |
380 | } | |
381 | EXPORT_SYMBOL_GPL(__xenbus_register_frontend); | |
382 | ||
383 | void xenbus_unregister_driver(struct xenbus_driver *drv) | |
384 | { | |
385 | driver_unregister(&drv->driver); | |
386 | } | |
387 | EXPORT_SYMBOL_GPL(xenbus_unregister_driver); | |
388 | ||
389 | struct xb_find_info | |
390 | { | |
391 | struct xenbus_device *dev; | |
392 | const char *nodename; | |
393 | }; | |
394 | ||
395 | static int cmp_dev(struct device *dev, void *data) | |
396 | { | |
397 | struct xenbus_device *xendev = to_xenbus_device(dev); | |
398 | struct xb_find_info *info = data; | |
399 | ||
400 | if (!strcmp(xendev->nodename, info->nodename)) { | |
401 | info->dev = xendev; | |
402 | get_device(dev); | |
403 | return 1; | |
404 | } | |
405 | return 0; | |
406 | } | |
407 | ||
408 | struct xenbus_device *xenbus_device_find(const char *nodename, | |
409 | struct bus_type *bus) | |
410 | { | |
411 | struct xb_find_info info = { .dev = NULL, .nodename = nodename }; | |
412 | ||
413 | bus_for_each_dev(bus, NULL, &info, cmp_dev); | |
414 | return info.dev; | |
415 | } | |
416 | ||
417 | static int cleanup_dev(struct device *dev, void *data) | |
418 | { | |
419 | struct xenbus_device *xendev = to_xenbus_device(dev); | |
420 | struct xb_find_info *info = data; | |
421 | int len = strlen(info->nodename); | |
422 | ||
423 | DPRINTK("%s", info->nodename); | |
424 | ||
425 | /* Match the info->nodename path, or any subdirectory of that path. */ | |
426 | if (strncmp(xendev->nodename, info->nodename, len)) | |
427 | return 0; | |
428 | ||
429 | /* If the node name is longer, ensure it really is a subdirectory. */ | |
430 | if ((strlen(xendev->nodename) > len) && (xendev->nodename[len] != '/')) | |
431 | return 0; | |
432 | ||
433 | info->dev = xendev; | |
434 | get_device(dev); | |
435 | return 1; | |
436 | } | |
437 | ||
438 | static void xenbus_cleanup_devices(const char *path, struct bus_type *bus) | |
439 | { | |
440 | struct xb_find_info info = { .nodename = path }; | |
441 | ||
442 | do { | |
443 | info.dev = NULL; | |
444 | bus_for_each_dev(bus, NULL, &info, cleanup_dev); | |
445 | if (info.dev) { | |
446 | device_unregister(&info.dev->dev); | |
447 | put_device(&info.dev->dev); | |
448 | } | |
449 | } while (info.dev); | |
450 | } | |
451 | ||
452 | static void xenbus_dev_release(struct device *dev) | |
453 | { | |
454 | if (dev) | |
455 | kfree(to_xenbus_device(dev)); | |
456 | } | |
457 | ||
458 | static ssize_t xendev_show_nodename(struct device *dev, | |
459 | struct device_attribute *attr, char *buf) | |
460 | { | |
461 | return sprintf(buf, "%s\n", to_xenbus_device(dev)->nodename); | |
462 | } | |
db05fed0 | 463 | static DEVICE_ATTR(nodename, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_nodename, NULL); |
4bac07c9 JF |
464 | |
465 | static ssize_t xendev_show_devtype(struct device *dev, | |
466 | struct device_attribute *attr, char *buf) | |
467 | { | |
468 | return sprintf(buf, "%s\n", to_xenbus_device(dev)->devicetype); | |
469 | } | |
db05fed0 | 470 | static DEVICE_ATTR(devtype, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_devtype, NULL); |
4bac07c9 | 471 | |
d2f0c52b MM |
472 | static ssize_t xendev_show_modalias(struct device *dev, |
473 | struct device_attribute *attr, char *buf) | |
474 | { | |
475 | return sprintf(buf, "xen:%s\n", to_xenbus_device(dev)->devicetype); | |
476 | } | |
db05fed0 | 477 | static DEVICE_ATTR(modalias, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_modalias, NULL); |
4bac07c9 JF |
478 | |
479 | int xenbus_probe_node(struct xen_bus_type *bus, | |
480 | const char *type, | |
481 | const char *nodename) | |
482 | { | |
2a678cc5 | 483 | char devname[XEN_BUS_ID_SIZE]; |
4bac07c9 JF |
484 | int err; |
485 | struct xenbus_device *xendev; | |
486 | size_t stringlen; | |
487 | char *tmpstring; | |
488 | ||
489 | enum xenbus_state state = xenbus_read_driver_state(nodename); | |
490 | ||
491 | if (state != XenbusStateInitialising) { | |
492 | /* Device is not new, so ignore it. This can happen if a | |
493 | device is going away after switching to Closed. */ | |
494 | return 0; | |
495 | } | |
496 | ||
497 | stringlen = strlen(nodename) + 1 + strlen(type) + 1; | |
498 | xendev = kzalloc(sizeof(*xendev) + stringlen, GFP_KERNEL); | |
499 | if (!xendev) | |
500 | return -ENOMEM; | |
501 | ||
502 | xendev->state = XenbusStateInitialising; | |
503 | ||
504 | /* Copy the strings into the extra space. */ | |
505 | ||
506 | tmpstring = (char *)(xendev + 1); | |
507 | strcpy(tmpstring, nodename); | |
508 | xendev->nodename = tmpstring; | |
509 | ||
510 | tmpstring += strlen(tmpstring) + 1; | |
511 | strcpy(tmpstring, type); | |
512 | xendev->devicetype = tmpstring; | |
513 | init_completion(&xendev->down); | |
514 | ||
515 | xendev->dev.bus = &bus->bus; | |
516 | xendev->dev.release = xenbus_dev_release; | |
517 | ||
2a678cc5 | 518 | err = bus->get_bus_id(devname, xendev->nodename); |
4bac07c9 JF |
519 | if (err) |
520 | goto fail; | |
521 | ||
2a678cc5 KS |
522 | dev_set_name(&xendev->dev, devname); |
523 | ||
4bac07c9 JF |
524 | /* Register with generic device framework. */ |
525 | err = device_register(&xendev->dev); | |
526 | if (err) | |
527 | goto fail; | |
528 | ||
529 | err = device_create_file(&xendev->dev, &dev_attr_nodename); | |
530 | if (err) | |
531 | goto fail_unregister; | |
532 | ||
533 | err = device_create_file(&xendev->dev, &dev_attr_devtype); | |
534 | if (err) | |
d2f0c52b MM |
535 | goto fail_remove_nodename; |
536 | ||
537 | err = device_create_file(&xendev->dev, &dev_attr_modalias); | |
538 | if (err) | |
539 | goto fail_remove_devtype; | |
4bac07c9 JF |
540 | |
541 | return 0; | |
d2f0c52b MM |
542 | fail_remove_devtype: |
543 | device_remove_file(&xendev->dev, &dev_attr_devtype); | |
544 | fail_remove_nodename: | |
4bac07c9 JF |
545 | device_remove_file(&xendev->dev, &dev_attr_nodename); |
546 | fail_unregister: | |
547 | device_unregister(&xendev->dev); | |
548 | fail: | |
549 | kfree(xendev); | |
550 | return err; | |
551 | } | |
552 | ||
553 | /* device/<typename>/<name> */ | |
554 | static int xenbus_probe_frontend(const char *type, const char *name) | |
555 | { | |
556 | char *nodename; | |
557 | int err; | |
558 | ||
559 | nodename = kasprintf(GFP_KERNEL, "%s/%s/%s", | |
560 | xenbus_frontend.root, type, name); | |
561 | if (!nodename) | |
562 | return -ENOMEM; | |
563 | ||
564 | DPRINTK("%s", nodename); | |
565 | ||
566 | err = xenbus_probe_node(&xenbus_frontend, type, nodename); | |
567 | kfree(nodename); | |
568 | return err; | |
569 | } | |
570 | ||
571 | static int xenbus_probe_device_type(struct xen_bus_type *bus, const char *type) | |
572 | { | |
573 | int err = 0; | |
574 | char **dir; | |
575 | unsigned int dir_n = 0; | |
576 | int i; | |
577 | ||
578 | dir = xenbus_directory(XBT_NIL, bus->root, type, &dir_n); | |
579 | if (IS_ERR(dir)) | |
580 | return PTR_ERR(dir); | |
581 | ||
582 | for (i = 0; i < dir_n; i++) { | |
583 | err = bus->probe(type, dir[i]); | |
584 | if (err) | |
585 | break; | |
586 | } | |
587 | kfree(dir); | |
588 | return err; | |
589 | } | |
590 | ||
591 | int xenbus_probe_devices(struct xen_bus_type *bus) | |
592 | { | |
593 | int err = 0; | |
594 | char **dir; | |
595 | unsigned int i, dir_n; | |
596 | ||
597 | dir = xenbus_directory(XBT_NIL, bus->root, "", &dir_n); | |
598 | if (IS_ERR(dir)) | |
599 | return PTR_ERR(dir); | |
600 | ||
601 | for (i = 0; i < dir_n; i++) { | |
602 | err = xenbus_probe_device_type(bus, dir[i]); | |
603 | if (err) | |
604 | break; | |
605 | } | |
606 | kfree(dir); | |
607 | return err; | |
608 | } | |
609 | ||
610 | static unsigned int char_count(const char *str, char c) | |
611 | { | |
612 | unsigned int i, ret = 0; | |
613 | ||
614 | for (i = 0; str[i]; i++) | |
615 | if (str[i] == c) | |
616 | ret++; | |
617 | return ret; | |
618 | } | |
619 | ||
620 | static int strsep_len(const char *str, char c, unsigned int len) | |
621 | { | |
622 | unsigned int i; | |
623 | ||
624 | for (i = 0; str[i]; i++) | |
625 | if (str[i] == c) { | |
626 | if (len == 0) | |
627 | return i; | |
628 | len--; | |
629 | } | |
630 | return (len == 0) ? i : -ERANGE; | |
631 | } | |
632 | ||
633 | void xenbus_dev_changed(const char *node, struct xen_bus_type *bus) | |
634 | { | |
635 | int exists, rootlen; | |
636 | struct xenbus_device *dev; | |
2a678cc5 | 637 | char type[XEN_BUS_ID_SIZE]; |
4bac07c9 JF |
638 | const char *p, *root; |
639 | ||
640 | if (char_count(node, '/') < 2) | |
641 | return; | |
642 | ||
643 | exists = xenbus_exists(XBT_NIL, node, ""); | |
644 | if (!exists) { | |
645 | xenbus_cleanup_devices(node, &bus->bus); | |
646 | return; | |
647 | } | |
648 | ||
649 | /* backend/<type>/... or device/<type>/... */ | |
650 | p = strchr(node, '/') + 1; | |
2a678cc5 KS |
651 | snprintf(type, XEN_BUS_ID_SIZE, "%.*s", (int)strcspn(p, "/"), p); |
652 | type[XEN_BUS_ID_SIZE-1] = '\0'; | |
4bac07c9 JF |
653 | |
654 | rootlen = strsep_len(node, '/', bus->levels); | |
655 | if (rootlen < 0) | |
656 | return; | |
657 | root = kasprintf(GFP_KERNEL, "%.*s", rootlen, node); | |
658 | if (!root) | |
659 | return; | |
660 | ||
661 | dev = xenbus_device_find(root, &bus->bus); | |
662 | if (!dev) | |
663 | xenbus_probe_node(bus, type, root); | |
664 | else | |
665 | put_device(&dev->dev); | |
666 | ||
667 | kfree(root); | |
668 | } | |
c6a960ce | 669 | EXPORT_SYMBOL_GPL(xenbus_dev_changed); |
4bac07c9 JF |
670 | |
671 | static void frontend_changed(struct xenbus_watch *watch, | |
672 | const char **vec, unsigned int len) | |
673 | { | |
674 | DPRINTK(""); | |
675 | ||
676 | xenbus_dev_changed(vec[XS_WATCH_PATH], &xenbus_frontend); | |
677 | } | |
678 | ||
679 | /* We watch for devices appearing and vanishing. */ | |
680 | static struct xenbus_watch fe_watch = { | |
681 | .node = "device", | |
682 | .callback = frontend_changed, | |
683 | }; | |
684 | ||
de5b31bd | 685 | static int xenbus_dev_suspend(struct device *dev, pm_message_t state) |
4bac07c9 JF |
686 | { |
687 | int err = 0; | |
688 | struct xenbus_driver *drv; | |
689 | struct xenbus_device *xdev; | |
690 | ||
691 | DPRINTK(""); | |
692 | ||
693 | if (dev->driver == NULL) | |
694 | return 0; | |
695 | drv = to_xenbus_driver(dev->driver); | |
696 | xdev = container_of(dev, struct xenbus_device, dev); | |
697 | if (drv->suspend) | |
de5b31bd | 698 | err = drv->suspend(xdev, state); |
4bac07c9 JF |
699 | if (err) |
700 | printk(KERN_WARNING | |
2a678cc5 | 701 | "xenbus: suspend %s failed: %i\n", dev_name(dev), err); |
4bac07c9 JF |
702 | return 0; |
703 | } | |
704 | ||
de5b31bd | 705 | static int xenbus_dev_resume(struct device *dev) |
4bac07c9 JF |
706 | { |
707 | int err; | |
708 | struct xenbus_driver *drv; | |
709 | struct xenbus_device *xdev; | |
710 | ||
711 | DPRINTK(""); | |
712 | ||
713 | if (dev->driver == NULL) | |
714 | return 0; | |
715 | ||
716 | drv = to_xenbus_driver(dev->driver); | |
717 | xdev = container_of(dev, struct xenbus_device, dev); | |
718 | ||
719 | err = talk_to_otherend(xdev); | |
720 | if (err) { | |
721 | printk(KERN_WARNING | |
722 | "xenbus: resume (talk_to_otherend) %s failed: %i\n", | |
2a678cc5 | 723 | dev_name(dev), err); |
4bac07c9 JF |
724 | return err; |
725 | } | |
726 | ||
727 | xdev->state = XenbusStateInitialising; | |
728 | ||
729 | if (drv->resume) { | |
730 | err = drv->resume(xdev); | |
731 | if (err) { | |
732 | printk(KERN_WARNING | |
733 | "xenbus: resume %s failed: %i\n", | |
2a678cc5 | 734 | dev_name(dev), err); |
4bac07c9 JF |
735 | return err; |
736 | } | |
737 | } | |
738 | ||
739 | err = watch_otherend(xdev); | |
740 | if (err) { | |
741 | printk(KERN_WARNING | |
742 | "xenbus_probe: resume (watch_otherend) %s failed: " | |
2a678cc5 | 743 | "%d.\n", dev_name(dev), err); |
4bac07c9 JF |
744 | return err; |
745 | } | |
746 | ||
747 | return 0; | |
748 | } | |
749 | ||
4bac07c9 JF |
750 | /* A flag to determine if xenstored is 'ready' (i.e. has started) */ |
751 | int xenstored_ready = 0; | |
752 | ||
753 | ||
754 | int register_xenstore_notifier(struct notifier_block *nb) | |
755 | { | |
756 | int ret = 0; | |
757 | ||
a947f0f8 SS |
758 | if (xenstored_ready > 0) |
759 | ret = nb->notifier_call(nb, 0, NULL); | |
760 | else | |
761 | blocking_notifier_chain_register(&xenstore_chain, nb); | |
4bac07c9 JF |
762 | |
763 | return ret; | |
764 | } | |
765 | EXPORT_SYMBOL_GPL(register_xenstore_notifier); | |
766 | ||
767 | void unregister_xenstore_notifier(struct notifier_block *nb) | |
768 | { | |
769 | blocking_notifier_chain_unregister(&xenstore_chain, nb); | |
770 | } | |
771 | EXPORT_SYMBOL_GPL(unregister_xenstore_notifier); | |
772 | ||
773 | void xenbus_probe(struct work_struct *unused) | |
774 | { | |
a947f0f8 | 775 | xenstored_ready = 1; |
4bac07c9 JF |
776 | |
777 | /* Enumerate devices in xenstore and watch for changes. */ | |
778 | xenbus_probe_devices(&xenbus_frontend); | |
779 | register_xenbus_watch(&fe_watch); | |
780 | xenbus_backend_probe_and_watch(); | |
781 | ||
782 | /* Notify others that xenstore is up */ | |
783 | blocking_notifier_call_chain(&xenstore_chain, 0, NULL); | |
784 | } | |
183d03cc | 785 | EXPORT_SYMBOL_GPL(xenbus_probe); |
4bac07c9 | 786 | |
183d03cc SS |
787 | static int __init xenbus_probe_initcall(void) |
788 | { | |
789 | if (!xen_domain()) | |
790 | return -ENODEV; | |
791 | ||
792 | if (xen_initial_domain() || xen_hvm_domain()) | |
793 | return 0; | |
794 | ||
795 | xenbus_probe(NULL); | |
796 | return 0; | |
797 | } | |
798 | ||
799 | device_initcall(xenbus_probe_initcall); | |
800 | ||
801 | static int __init xenbus_init(void) | |
4bac07c9 JF |
802 | { |
803 | int err = 0; | |
804 | ||
805 | DPRINTK(""); | |
806 | ||
807 | err = -ENODEV; | |
6e833587 | 808 | if (!xen_domain()) |
4bac07c9 JF |
809 | goto out_error; |
810 | ||
811 | /* Register ourselves with the kernel bus subsystem */ | |
812 | err = bus_register(&xenbus_frontend.bus); | |
813 | if (err) | |
814 | goto out_error; | |
815 | ||
816 | err = xenbus_backend_bus_register(); | |
817 | if (err) | |
818 | goto out_unreg_front; | |
819 | ||
820 | /* | |
821 | * Domain0 doesn't have a store_evtchn or store_mfn yet. | |
822 | */ | |
6e833587 | 823 | if (xen_initial_domain()) { |
4bac07c9 JF |
824 | /* dom0 not yet supported */ |
825 | } else { | |
bee6ab53 SY |
826 | if (xen_hvm_domain()) { |
827 | uint64_t v = 0; | |
828 | err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v); | |
829 | if (err) | |
830 | goto out_error; | |
831 | xen_store_evtchn = (int)v; | |
832 | err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v); | |
833 | if (err) | |
834 | goto out_error; | |
835 | xen_store_mfn = (unsigned long)v; | |
836 | xen_store_interface = ioremap(xen_store_mfn << PAGE_SHIFT, PAGE_SIZE); | |
837 | } else { | |
838 | xen_store_evtchn = xen_start_info->store_evtchn; | |
839 | xen_store_mfn = xen_start_info->store_mfn; | |
840 | xen_store_interface = mfn_to_virt(xen_store_mfn); | |
a947f0f8 | 841 | xenstored_ready = 1; |
bee6ab53 | 842 | } |
4bac07c9 | 843 | } |
4bac07c9 JF |
844 | |
845 | /* Initialize the interface to xenstore. */ | |
846 | err = xs_init(); | |
847 | if (err) { | |
848 | printk(KERN_WARNING | |
849 | "XENBUS: Error initializing xenstore comms: %i\n", err); | |
850 | goto out_unreg_back; | |
851 | } | |
852 | ||
1107ba88 AZ |
853 | #ifdef CONFIG_XEN_COMPAT_XENFS |
854 | /* | |
855 | * Create xenfs mountpoint in /proc for compatibility with | |
856 | * utilities that expect to find "xenbus" under "/proc/xen". | |
857 | */ | |
858 | proc_mkdir("xen", NULL); | |
859 | #endif | |
860 | ||
4bac07c9 JF |
861 | return 0; |
862 | ||
863 | out_unreg_back: | |
864 | xenbus_backend_bus_unregister(); | |
865 | ||
866 | out_unreg_front: | |
867 | bus_unregister(&xenbus_frontend.bus); | |
868 | ||
869 | out_error: | |
870 | return err; | |
871 | } | |
872 | ||
183d03cc | 873 | postcore_initcall(xenbus_init); |
4bac07c9 JF |
874 | |
875 | MODULE_LICENSE("GPL"); | |
876 | ||
c6e19711 | 877 | static int is_device_connecting(struct device *dev, void *data) |
4bac07c9 JF |
878 | { |
879 | struct xenbus_device *xendev = to_xenbus_device(dev); | |
880 | struct device_driver *drv = data; | |
1d78d705 | 881 | struct xenbus_driver *xendrv; |
4bac07c9 JF |
882 | |
883 | /* | |
884 | * A device with no driver will never connect. We care only about | |
885 | * devices which should currently be in the process of connecting. | |
886 | */ | |
887 | if (!dev->driver) | |
888 | return 0; | |
889 | ||
890 | /* Is this search limited to a particular driver? */ | |
891 | if (drv && (dev->driver != drv)) | |
892 | return 0; | |
893 | ||
1d78d705 | 894 | xendrv = to_xenbus_driver(dev->driver); |
c6e19711 PB |
895 | return (xendev->state < XenbusStateConnected || |
896 | (xendev->state == XenbusStateConnected && | |
897 | xendrv->is_ready && !xendrv->is_ready(xendev))); | |
4bac07c9 JF |
898 | } |
899 | ||
c6e19711 | 900 | static int exists_connecting_device(struct device_driver *drv) |
4bac07c9 JF |
901 | { |
902 | return bus_for_each_dev(&xenbus_frontend.bus, NULL, drv, | |
c6e19711 | 903 | is_device_connecting); |
4bac07c9 JF |
904 | } |
905 | ||
906 | static int print_device_status(struct device *dev, void *data) | |
907 | { | |
908 | struct xenbus_device *xendev = to_xenbus_device(dev); | |
909 | struct device_driver *drv = data; | |
910 | ||
911 | /* Is this operation limited to a particular driver? */ | |
912 | if (drv && (dev->driver != drv)) | |
913 | return 0; | |
914 | ||
915 | if (!dev->driver) { | |
916 | /* Information only: is this too noisy? */ | |
917 | printk(KERN_INFO "XENBUS: Device with no driver: %s\n", | |
918 | xendev->nodename); | |
f8dc3308 PB |
919 | } else if (xendev->state < XenbusStateConnected) { |
920 | enum xenbus_state rstate = XenbusStateUnknown; | |
921 | if (xendev->otherend) | |
922 | rstate = xenbus_read_driver_state(xendev->otherend); | |
4bac07c9 | 923 | printk(KERN_WARNING "XENBUS: Timeout connecting " |
f8dc3308 PB |
924 | "to device: %s (local state %d, remote state %d)\n", |
925 | xendev->nodename, xendev->state, rstate); | |
4bac07c9 JF |
926 | } |
927 | ||
928 | return 0; | |
929 | } | |
930 | ||
931 | /* We only wait for device setup after most initcalls have run. */ | |
932 | static int ready_to_wait_for_devices; | |
933 | ||
934 | /* | |
ae788801 | 935 | * On a 5-minute timeout, wait for all devices currently configured. We need |
4bac07c9 JF |
936 | * to do this to guarantee that the filesystems and / or network devices |
937 | * needed for boot are available, before we can allow the boot to proceed. | |
938 | * | |
939 | * This needs to be on a late_initcall, to happen after the frontend device | |
940 | * drivers have been initialised, but before the root fs is mounted. | |
941 | * | |
942 | * A possible improvement here would be to have the tools add a per-device | |
943 | * flag to the store entry, indicating whether it is needed at boot time. | |
944 | * This would allow people who knew what they were doing to accelerate their | |
945 | * boot slightly, but of course needs tools or manual intervention to set up | |
946 | * those flags correctly. | |
947 | */ | |
948 | static void wait_for_devices(struct xenbus_driver *xendrv) | |
949 | { | |
ae788801 | 950 | unsigned long start = jiffies; |
4bac07c9 | 951 | struct device_driver *drv = xendrv ? &xendrv->driver : NULL; |
ae788801 | 952 | unsigned int seconds_waited = 0; |
4bac07c9 | 953 | |
6e833587 | 954 | if (!ready_to_wait_for_devices || !xen_domain()) |
4bac07c9 JF |
955 | return; |
956 | ||
c6e19711 | 957 | while (exists_connecting_device(drv)) { |
ae788801 PB |
958 | if (time_after(jiffies, start + (seconds_waited+5)*HZ)) { |
959 | if (!seconds_waited) | |
960 | printk(KERN_WARNING "XENBUS: Waiting for " | |
961 | "devices to initialise: "); | |
962 | seconds_waited += 5; | |
963 | printk("%us...", 300 - seconds_waited); | |
964 | if (seconds_waited == 300) | |
965 | break; | |
966 | } | |
967 | ||
4bac07c9 JF |
968 | schedule_timeout_interruptible(HZ/10); |
969 | } | |
970 | ||
ae788801 PB |
971 | if (seconds_waited) |
972 | printk("\n"); | |
973 | ||
4bac07c9 JF |
974 | bus_for_each_dev(&xenbus_frontend.bus, NULL, drv, |
975 | print_device_status); | |
976 | } | |
977 | ||
978 | #ifndef MODULE | |
979 | static int __init boot_wait_for_devices(void) | |
980 | { | |
c1c5413a SS |
981 | if (xen_hvm_domain() && !xen_platform_pci_unplug) |
982 | return -ENODEV; | |
983 | ||
4bac07c9 JF |
984 | ready_to_wait_for_devices = 1; |
985 | wait_for_devices(NULL); | |
986 | return 0; | |
987 | } | |
988 | ||
989 | late_initcall(boot_wait_for_devices); | |
990 | #endif |