diff options
author | Jeremy Fitzhardinge <jeremy@xensource.com> | 2007-07-17 21:37:06 -0400 |
---|---|---|
committer | Jeremy Fitzhardinge <jeremy@goop.org> | 2007-07-18 11:47:45 -0400 |
commit | 4bac07c993d03434ea902d3d4290d9e45944b66c (patch) | |
tree | 1930a1d8c23d3968d4644edda50791ff390bfe93 /drivers/xen | |
parent | ad9a86121f5a374b48ce2924f8a9d7e94a04db27 (diff) |
xen: add the Xenbus sysfs and virtual device hotplug driver
This communicates with the machine control software via a registry
residing in a controlling virtual machine. This allows dynamic
creation, destruction and modification of virtual device
configurations (network devices, block devices and CPUS, to name some
examples).
[ Greg, would you mind giving this a review? Thanks -J ]
Signed-off-by: Ian Pratt <ian.pratt@xensource.com>
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Greg KH <greg@kroah.com>
Diffstat (limited to 'drivers/xen')
-rw-r--r-- | drivers/xen/Makefile | 1 | ||||
-rw-r--r-- | drivers/xen/xenbus/Makefile | 7 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_client.c | 569 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_comms.c | 233 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_comms.h | 46 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_probe.c | 935 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_probe.h | 74 | ||||
-rw-r--r-- | drivers/xen/xenbus/xenbus_xs.c | 861 |
8 files changed, 2726 insertions, 0 deletions
diff --git a/drivers/xen/Makefile b/drivers/xen/Makefile index eb42b521eef..56592f0d6ce 100644 --- a/drivers/xen/Makefile +++ b/drivers/xen/Makefile | |||
@@ -1 +1,2 @@ | |||
1 | obj-y += grant-table.o | 1 | obj-y += grant-table.o |
2 | obj-y += xenbus/ | ||
diff --git a/drivers/xen/xenbus/Makefile b/drivers/xen/xenbus/Makefile new file mode 100644 index 00000000000..5571f5b8422 --- /dev/null +++ b/drivers/xen/xenbus/Makefile | |||
@@ -0,0 +1,7 @@ | |||
1 | obj-y += xenbus.o | ||
2 | |||
3 | xenbus-objs = | ||
4 | xenbus-objs += xenbus_client.o | ||
5 | xenbus-objs += xenbus_comms.o | ||
6 | xenbus-objs += xenbus_xs.o | ||
7 | xenbus-objs += xenbus_probe.o | ||
diff --git a/drivers/xen/xenbus/xenbus_client.c b/drivers/xen/xenbus/xenbus_client.c new file mode 100644 index 00000000000..9fd2f70ab46 --- /dev/null +++ b/drivers/xen/xenbus/xenbus_client.c | |||
@@ -0,0 +1,569 @@ | |||
1 | /****************************************************************************** | ||
2 | * Client-facing interface for the Xenbus driver. In other words, the | ||
3 | * interface between the Xenbus and the device-specific code, be it the | ||
4 | * frontend or the backend of that driver. | ||
5 | * | ||
6 | * Copyright (C) 2005 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 | #include <linux/types.h> | ||
34 | #include <linux/vmalloc.h> | ||
35 | #include <asm/xen/hypervisor.h> | ||
36 | #include <xen/interface/xen.h> | ||
37 | #include <xen/interface/event_channel.h> | ||
38 | #include <xen/events.h> | ||
39 | #include <xen/grant_table.h> | ||
40 | #include <xen/xenbus.h> | ||
41 | |||
42 | const char *xenbus_strstate(enum xenbus_state state) | ||
43 | { | ||
44 | static const char *const name[] = { | ||
45 | [ XenbusStateUnknown ] = "Unknown", | ||
46 | [ XenbusStateInitialising ] = "Initialising", | ||
47 | [ XenbusStateInitWait ] = "InitWait", | ||
48 | [ XenbusStateInitialised ] = "Initialised", | ||
49 | [ XenbusStateConnected ] = "Connected", | ||
50 | [ XenbusStateClosing ] = "Closing", | ||
51 | [ XenbusStateClosed ] = "Closed", | ||
52 | }; | ||
53 | return (state < ARRAY_SIZE(name)) ? name[state] : "INVALID"; | ||
54 | } | ||
55 | EXPORT_SYMBOL_GPL(xenbus_strstate); | ||
56 | |||
57 | /** | ||
58 | * xenbus_watch_path - register a watch | ||
59 | * @dev: xenbus device | ||
60 | * @path: path to watch | ||
61 | * @watch: watch to register | ||
62 | * @callback: callback to register | ||
63 | * | ||
64 | * Register a @watch on the given path, using the given xenbus_watch structure | ||
65 | * for storage, and the given @callback function as the callback. Return 0 on | ||
66 | * success, or -errno on error. On success, the given @path will be saved as | ||
67 | * @watch->node, and remains the caller's to free. On error, @watch->node will | ||
68 | * be NULL, the device will switch to %XenbusStateClosing, and the error will | ||
69 | * be saved in the store. | ||
70 | */ | ||
71 | int xenbus_watch_path(struct xenbus_device *dev, const char *path, | ||
72 | struct xenbus_watch *watch, | ||
73 | void (*callback)(struct xenbus_watch *, | ||
74 | const char **, unsigned int)) | ||
75 | { | ||
76 | int err; | ||
77 | |||
78 | watch->node = path; | ||
79 | watch->callback = callback; | ||
80 | |||
81 | err = register_xenbus_watch(watch); | ||
82 | |||
83 | if (err) { | ||
84 | watch->node = NULL; | ||
85 | watch->callback = NULL; | ||
86 | xenbus_dev_fatal(dev, err, "adding watch on %s", path); | ||
87 | } | ||
88 | |||
89 | return err; | ||
90 | } | ||
91 | EXPORT_SYMBOL_GPL(xenbus_watch_path); | ||
92 | |||
93 | |||
94 | /** | ||
95 | * xenbus_watch_pathfmt - register a watch on a sprintf-formatted path | ||
96 | * @dev: xenbus device | ||
97 | * @watch: watch to register | ||
98 | * @callback: callback to register | ||
99 | * @pathfmt: format of path to watch | ||
100 | * | ||
101 | * Register a watch on the given @path, using the given xenbus_watch | ||
102 | * structure for storage, and the given @callback function as the callback. | ||
103 | * Return 0 on success, or -errno on error. On success, the watched path | ||
104 | * (@path/@path2) will be saved as @watch->node, and becomes the caller's to | ||
105 | * kfree(). On error, watch->node will be NULL, so the caller has nothing to | ||
106 | * free, the device will switch to %XenbusStateClosing, and the error will be | ||
107 | * saved in the store. | ||
108 | */ | ||
109 | int xenbus_watch_pathfmt(struct xenbus_device *dev, | ||
110 | struct xenbus_watch *watch, | ||
111 | void (*callback)(struct xenbus_watch *, | ||
112 | const char **, unsigned int), | ||
113 | const char *pathfmt, ...) | ||
114 | { | ||
115 | int err; | ||
116 | va_list ap; | ||
117 | char *path; | ||
118 | |||
119 | va_start(ap, pathfmt); | ||
120 | path = kvasprintf(GFP_KERNEL, pathfmt, ap); | ||
121 | va_end(ap); | ||
122 | |||
123 | if (!path) { | ||
124 | xenbus_dev_fatal(dev, -ENOMEM, "allocating path for watch"); | ||
125 | return -ENOMEM; | ||
126 | } | ||
127 | err = xenbus_watch_path(dev, path, watch, callback); | ||
128 | |||
129 | if (err) | ||
130 | kfree(path); | ||
131 | return err; | ||
132 | } | ||
133 | EXPORT_SYMBOL_GPL(xenbus_watch_pathfmt); | ||
134 | |||
135 | |||
136 | /** | ||
137 | * xenbus_switch_state | ||
138 | * @dev: xenbus device | ||
139 | * @xbt: transaction handle | ||
140 | * @state: new state | ||
141 | * | ||
142 | * Advertise in the store a change of the given driver to the given new_state. | ||
143 | * Return 0 on success, or -errno on error. On error, the device will switch | ||
144 | * to XenbusStateClosing, and the error will be saved in the store. | ||
145 | */ | ||
146 | int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state state) | ||
147 | { | ||
148 | /* We check whether the state is currently set to the given value, and | ||
149 | if not, then the state is set. We don't want to unconditionally | ||
150 | write the given state, because we don't want to fire watches | ||
151 | unnecessarily. Furthermore, if the node has gone, we don't write | ||
152 | to it, as the device will be tearing down, and we don't want to | ||
153 | resurrect that directory. | ||
154 | |||
155 | Note that, because of this cached value of our state, this function | ||
156 | will not work inside a Xenstore transaction (something it was | ||
157 | trying to in the past) because dev->state would not get reset if | ||
158 | the transaction was aborted. | ||
159 | |||
160 | */ | ||
161 | |||
162 | int current_state; | ||
163 | int err; | ||
164 | |||
165 | if (state == dev->state) | ||
166 | return 0; | ||
167 | |||
168 | err = xenbus_scanf(XBT_NIL, dev->nodename, "state", "%d", | ||
169 | ¤t_state); | ||
170 | if (err != 1) | ||
171 | return 0; | ||
172 | |||
173 | err = xenbus_printf(XBT_NIL, dev->nodename, "state", "%d", state); | ||
174 | if (err) { | ||
175 | if (state != XenbusStateClosing) /* Avoid looping */ | ||
176 | xenbus_dev_fatal(dev, err, "writing new state"); | ||
177 | return err; | ||
178 | } | ||
179 | |||
180 | dev->state = state; | ||
181 | |||
182 | return 0; | ||
183 | } | ||
184 | EXPORT_SYMBOL_GPL(xenbus_switch_state); | ||
185 | |||
186 | int xenbus_frontend_closed(struct xenbus_device *dev) | ||
187 | { | ||
188 | xenbus_switch_state(dev, XenbusStateClosed); | ||
189 | complete(&dev->down); | ||
190 | return 0; | ||
191 | } | ||
192 | EXPORT_SYMBOL_GPL(xenbus_frontend_closed); | ||
193 | |||
194 | /** | ||
195 | * Return the path to the error node for the given device, or NULL on failure. | ||
196 | * If the value returned is non-NULL, then it is the caller's to kfree. | ||
197 | */ | ||
198 | static char *error_path(struct xenbus_device *dev) | ||
199 | { | ||
200 | return kasprintf(GFP_KERNEL, "error/%s", dev->nodename); | ||
201 | } | ||
202 | |||
203 | |||
204 | static void xenbus_va_dev_error(struct xenbus_device *dev, int err, | ||
205 | const char *fmt, va_list ap) | ||
206 | { | ||
207 | int ret; | ||
208 | unsigned int len; | ||
209 | char *printf_buffer = NULL; | ||
210 | char *path_buffer = NULL; | ||
211 | |||
212 | #define PRINTF_BUFFER_SIZE 4096 | ||
213 | printf_buffer = kmalloc(PRINTF_BUFFER_SIZE, GFP_KERNEL); | ||
214 | if (printf_buffer == NULL) | ||
215 | goto fail; | ||
216 | |||
217 | len = sprintf(printf_buffer, "%i ", -err); | ||
218 | ret = vsnprintf(printf_buffer+len, PRINTF_BUFFER_SIZE-len, fmt, ap); | ||
219 | |||
220 | BUG_ON(len + ret > PRINTF_BUFFER_SIZE-1); | ||
221 | |||
222 | dev_err(&dev->dev, "%s\n", printf_buffer); | ||
223 | |||
224 | path_buffer = error_path(dev); | ||
225 | |||
226 | if (path_buffer == NULL) { | ||
227 | dev_err(&dev->dev, "failed to write error node for %s (%s)\n", | ||
228 | dev->nodename, printf_buffer); | ||
229 | goto fail; | ||
230 | } | ||
231 | |||
232 | if (xenbus_write(XBT_NIL, path_buffer, "error", printf_buffer) != 0) { | ||
233 | dev_err(&dev->dev, "failed to write error node for %s (%s)\n", | ||
234 | dev->nodename, printf_buffer); | ||
235 | goto fail; | ||
236 | } | ||
237 | |||
238 | fail: | ||
239 | kfree(printf_buffer); | ||
240 | kfree(path_buffer); | ||
241 | } | ||
242 | |||
243 | |||
244 | /** | ||
245 | * xenbus_dev_error | ||
246 | * @dev: xenbus device | ||
247 | * @err: error to report | ||
248 | * @fmt: error message format | ||
249 | * | ||
250 | * Report the given negative errno into the store, along with the given | ||
251 | * formatted message. | ||
252 | */ | ||
253 | void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...) | ||
254 | { | ||
255 | va_list ap; | ||
256 | |||
257 | va_start(ap, fmt); | ||
258 | xenbus_va_dev_error(dev, err, fmt, ap); | ||
259 | va_end(ap); | ||
260 | } | ||
261 | EXPORT_SYMBOL_GPL(xenbus_dev_error); | ||
262 | |||
263 | /** | ||
264 | * xenbus_dev_fatal | ||
265 | * @dev: xenbus device | ||
266 | * @err: error to report | ||
267 | * @fmt: error message format | ||
268 | * | ||
269 | * Equivalent to xenbus_dev_error(dev, err, fmt, args), followed by | ||
270 | * xenbus_switch_state(dev, NULL, XenbusStateClosing) to schedule an orderly | ||
271 | * closedown of this driver and its peer. | ||
272 | */ | ||
273 | |||
274 | void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...) | ||
275 | { | ||
276 | va_list ap; | ||
277 | |||
278 | va_start(ap, fmt); | ||
279 | xenbus_va_dev_error(dev, err, fmt, ap); | ||
280 | va_end(ap); | ||
281 | |||
282 | xenbus_switch_state(dev, XenbusStateClosing); | ||
283 | } | ||
284 | EXPORT_SYMBOL_GPL(xenbus_dev_fatal); | ||
285 | |||
286 | /** | ||
287 | * xenbus_grant_ring | ||
288 | * @dev: xenbus device | ||
289 | * @ring_mfn: mfn of ring to grant | ||
290 | |||
291 | * Grant access to the given @ring_mfn to the peer of the given device. Return | ||
292 | * 0 on success, or -errno on error. On error, the device will switch to | ||
293 | * XenbusStateClosing, and the error will be saved in the store. | ||
294 | */ | ||
295 | int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn) | ||
296 | { | ||
297 | int err = gnttab_grant_foreign_access(dev->otherend_id, ring_mfn, 0); | ||
298 | if (err < 0) | ||
299 | xenbus_dev_fatal(dev, err, "granting access to ring page"); | ||
300 | return err; | ||
301 | } | ||
302 | EXPORT_SYMBOL_GPL(xenbus_grant_ring); | ||
303 | |||
304 | |||
305 | /** | ||
306 | * Allocate an event channel for the given xenbus_device, assigning the newly | ||
307 | * created local port to *port. Return 0 on success, or -errno on error. On | ||
308 | * error, the device will switch to XenbusStateClosing, and the error will be | ||
309 | * saved in the store. | ||
310 | */ | ||
311 | int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port) | ||
312 | { | ||
313 | struct evtchn_alloc_unbound alloc_unbound; | ||
314 | int err; | ||
315 | |||
316 | alloc_unbound.dom = DOMID_SELF; | ||
317 | alloc_unbound.remote_dom = dev->otherend_id; | ||
318 | |||
319 | err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, | ||
320 | &alloc_unbound); | ||
321 | if (err) | ||
322 | xenbus_dev_fatal(dev, err, "allocating event channel"); | ||
323 | else | ||
324 | *port = alloc_unbound.port; | ||
325 | |||
326 | return err; | ||
327 | } | ||
328 | EXPORT_SYMBOL_GPL(xenbus_alloc_evtchn); | ||
329 | |||
330 | |||
331 | /** | ||
332 | * Bind to an existing interdomain event channel in another domain. Returns 0 | ||
333 | * on success and stores the local port in *port. On error, returns -errno, | ||
334 | * switches the device to XenbusStateClosing, and saves the error in XenStore. | ||
335 | */ | ||
336 | int xenbus_bind_evtchn(struct xenbus_device *dev, int remote_port, int *port) | ||
337 | { | ||
338 | struct evtchn_bind_interdomain bind_interdomain; | ||
339 | int err; | ||
340 | |||
341 | bind_interdomain.remote_dom = dev->otherend_id; | ||
342 | bind_interdomain.remote_port = remote_port; | ||
343 | |||
344 | err = HYPERVISOR_event_channel_op(EVTCHNOP_bind_interdomain, | ||
345 | &bind_interdomain); | ||
346 | if (err) | ||
347 | xenbus_dev_fatal(dev, err, | ||
348 | "binding to event channel %d from domain %d", | ||
349 | remote_port, dev->otherend_id); | ||
350 | else | ||
351 | *port = bind_interdomain.local_port; | ||
352 | |||
353 | return err; | ||
354 | } | ||
355 | EXPORT_SYMBOL_GPL(xenbus_bind_evtchn); | ||
356 | |||
357 | |||
358 | /** | ||
359 | * Free an existing event channel. Returns 0 on success or -errno on error. | ||
360 | */ | ||
361 | int xenbus_free_evtchn(struct xenbus_device *dev, int port) | ||
362 | { | ||
363 | struct evtchn_close close; | ||
364 | int err; | ||
365 | |||
366 | close.port = port; | ||
367 | |||
368 | err = HYPERVISOR_event_channel_op(EVTCHNOP_close, &close); | ||
369 | if (err) | ||
370 | xenbus_dev_error(dev, err, "freeing event channel %d", port); | ||
371 | |||
372 | return err; | ||
373 | } | ||
374 | EXPORT_SYMBOL_GPL(xenbus_free_evtchn); | ||
375 | |||
376 | |||
377 | /** | ||
378 | * xenbus_map_ring_valloc | ||
379 | * @dev: xenbus device | ||
380 | * @gnt_ref: grant reference | ||
381 | * @vaddr: pointer to address to be filled out by mapping | ||
382 | * | ||
383 | * Based on Rusty Russell's skeleton driver's map_page. | ||
384 | * Map a page of memory into this domain from another domain's grant table. | ||
385 | * xenbus_map_ring_valloc allocates a page of virtual address space, maps the | ||
386 | * page to that address, and sets *vaddr to that address. | ||
387 | * Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h) | ||
388 | * or -ENOMEM on error. If an error is returned, device will switch to | ||
389 | * XenbusStateClosing and the error message will be saved in XenStore. | ||
390 | */ | ||
391 | int xenbus_map_ring_valloc(struct xenbus_device *dev, int gnt_ref, void **vaddr) | ||
392 | { | ||
393 | struct gnttab_map_grant_ref op = { | ||
394 | .flags = GNTMAP_host_map, | ||
395 | .ref = gnt_ref, | ||
396 | .dom = dev->otherend_id, | ||
397 | }; | ||
398 | struct vm_struct *area; | ||
399 | |||
400 | *vaddr = NULL; | ||
401 | |||
402 | area = alloc_vm_area(PAGE_SIZE); | ||
403 | if (!area) | ||
404 | return -ENOMEM; | ||
405 | |||
406 | op.host_addr = (unsigned long)area->addr; | ||
407 | |||
408 | if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1)) | ||
409 | BUG(); | ||
410 | |||
411 | if (op.status != GNTST_okay) { | ||
412 | free_vm_area(area); | ||
413 | xenbus_dev_fatal(dev, op.status, | ||
414 | "mapping in shared page %d from domain %d", | ||
415 | gnt_ref, dev->otherend_id); | ||
416 | return op.status; | ||
417 | } | ||
418 | |||
419 | /* Stuff the handle in an unused field */ | ||
420 | area->phys_addr = (unsigned long)op.handle; | ||
421 | |||
422 | *vaddr = area->addr; | ||
423 | return 0; | ||
424 | } | ||
425 | EXPORT_SYMBOL_GPL(xenbus_map_ring_valloc); | ||
426 | |||
427 | |||
428 | /** | ||
429 | * xenbus_map_ring | ||
430 | * @dev: xenbus device | ||
431 | * @gnt_ref: grant reference | ||
432 | * @handle: pointer to grant handle to be filled | ||
433 | * @vaddr: address to be mapped to | ||
434 | * | ||
435 | * Map a page of memory into this domain from another domain's grant table. | ||
436 | * xenbus_map_ring does not allocate the virtual address space (you must do | ||
437 | * this yourself!). It only maps in the page to the specified address. | ||
438 | * Returns 0 on success, and GNTST_* (see xen/include/interface/grant_table.h) | ||
439 | * or -ENOMEM on error. If an error is returned, device will switch to | ||
440 | * XenbusStateClosing and the error message will be saved in XenStore. | ||
441 | */ | ||
442 | int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref, | ||
443 | grant_handle_t *handle, void *vaddr) | ||
444 | { | ||
445 | struct gnttab_map_grant_ref op = { | ||
446 | .host_addr = (unsigned long)vaddr, | ||
447 | .flags = GNTMAP_host_map, | ||
448 | .ref = gnt_ref, | ||
449 | .dom = dev->otherend_id, | ||
450 | }; | ||
451 | |||
452 | if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1)) | ||
453 | BUG(); | ||
454 | |||
455 | if (op.status != GNTST_okay) { | ||
456 | xenbus_dev_fatal(dev, op.status, | ||
457 | "mapping in shared page %d from domain %d", | ||
458 | gnt_ref, dev->otherend_id); | ||
459 | } else | ||
460 | *handle = op.handle; | ||
461 | |||
462 | return op.status; | ||
463 | } | ||
464 | EXPORT_SYMBOL_GPL(xenbus_map_ring); | ||
465 | |||
466 | |||
467 | /** | ||
468 | * xenbus_unmap_ring_vfree | ||
469 | * @dev: xenbus device | ||
470 | * @vaddr: addr to unmap | ||
471 | * | ||
472 | * Based on Rusty Russell's skeleton driver's unmap_page. | ||
473 | * Unmap a page of memory in this domain that was imported from another domain. | ||
474 | * Use xenbus_unmap_ring_vfree if you mapped in your memory with | ||
475 | * xenbus_map_ring_valloc (it will free the virtual address space). | ||
476 | * Returns 0 on success and returns GNTST_* on error | ||
477 | * (see xen/include/interface/grant_table.h). | ||
478 | */ | ||
479 | int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr) | ||
480 | { | ||
481 | struct vm_struct *area; | ||
482 | struct gnttab_unmap_grant_ref op = { | ||
483 | .host_addr = (unsigned long)vaddr, | ||
484 | }; | ||
485 | |||
486 | /* It'd be nice if linux/vmalloc.h provided a find_vm_area(void *addr) | ||
487 | * method so that we don't have to muck with vmalloc internals here. | ||
488 | * We could force the user to hang on to their struct vm_struct from | ||
489 | * xenbus_map_ring_valloc, but these 6 lines considerably simplify | ||
490 | * this API. | ||
491 | */ | ||
492 | read_lock(&vmlist_lock); | ||
493 | for (area = vmlist; area != NULL; area = area->next) { | ||
494 | if (area->addr == vaddr) | ||
495 | break; | ||
496 | } | ||
497 | read_unlock(&vmlist_lock); | ||
498 | |||
499 | if (!area) { | ||
500 | xenbus_dev_error(dev, -ENOENT, | ||
501 | "can't find mapped virtual address %p", vaddr); | ||
502 | return GNTST_bad_virt_addr; | ||
503 | } | ||
504 | |||
505 | op.handle = (grant_handle_t)area->phys_addr; | ||
506 | |||
507 | if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1)) | ||
508 | BUG(); | ||
509 | |||
510 | if (op.status == GNTST_okay) | ||
511 | free_vm_area(area); | ||
512 | else | ||
513 | xenbus_dev_error(dev, op.status, | ||
514 | "unmapping page at handle %d error %d", | ||
515 | (int16_t)area->phys_addr, op.status); | ||
516 | |||
517 | return op.status; | ||
518 | } | ||
519 | EXPORT_SYMBOL_GPL(xenbus_unmap_ring_vfree); | ||
520 | |||
521 | |||
522 | /** | ||
523 | * xenbus_unmap_ring | ||
524 | * @dev: xenbus device | ||
525 | * @handle: grant handle | ||
526 | * @vaddr: addr to unmap | ||
527 | * | ||
528 | * Unmap a page of memory in this domain that was imported from another domain. | ||
529 | * Returns 0 on success and returns GNTST_* on error | ||
530 | * (see xen/include/interface/grant_table.h). | ||
531 | */ | ||
532 | int xenbus_unmap_ring(struct xenbus_device *dev, | ||
533 | grant_handle_t handle, void *vaddr) | ||
534 | { | ||
535 | struct gnttab_unmap_grant_ref op = { | ||
536 | .host_addr = (unsigned long)vaddr, | ||
537 | .handle = handle, | ||
538 | }; | ||
539 | |||
540 | if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1)) | ||
541 | BUG(); | ||
542 | |||
543 | if (op.status != GNTST_okay) | ||
544 | xenbus_dev_error(dev, op.status, | ||
545 | "unmapping page at handle %d error %d", | ||
546 | handle, op.status); | ||
547 | |||
548 | return op.status; | ||
549 | } | ||
550 | EXPORT_SYMBOL_GPL(xenbus_unmap_ring); | ||
551 | |||
552 | |||
553 | /** | ||
554 | * xenbus_read_driver_state | ||
555 | * @path: path for driver | ||
556 | * | ||
557 | * Return the state of the driver rooted at the given store path, or | ||
558 | * XenbusStateUnknown if no state can be read. | ||
559 | */ | ||
560 | enum xenbus_state xenbus_read_driver_state(const char *path) | ||
561 | { | ||
562 | enum xenbus_state result; | ||
563 | int err = xenbus_gather(XBT_NIL, path, "state", "%d", &result, NULL); | ||
564 | if (err) | ||
565 | result = XenbusStateUnknown; | ||
566 | |||
567 | return result; | ||
568 | } | ||
569 | EXPORT_SYMBOL_GPL(xenbus_read_driver_state); | ||
diff --git a/drivers/xen/xenbus/xenbus_comms.c b/drivers/xen/xenbus/xenbus_comms.c new file mode 100644 index 00000000000..6efbe3f29ca --- /dev/null +++ b/drivers/xen/xenbus/xenbus_comms.c | |||
@@ -0,0 +1,233 @@ | |||
1 | /****************************************************************************** | ||
2 | * xenbus_comms.c | ||
3 | * | ||
4 | * Low level code to talks to Xen Store: ringbuffer and event channel. | ||
5 | * | ||
6 | * Copyright (C) 2005 Rusty Russell, IBM Corporation | ||
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 | #include <linux/wait.h> | ||
34 | #include <linux/interrupt.h> | ||
35 | #include <linux/sched.h> | ||
36 | #include <linux/err.h> | ||
37 | #include <xen/xenbus.h> | ||
38 | #include <asm/xen/hypervisor.h> | ||
39 | #include <xen/events.h> | ||
40 | #include <xen/page.h> | ||
41 | #include "xenbus_comms.h" | ||
42 | |||
43 | static int xenbus_irq; | ||
44 | |||
45 | static DECLARE_WORK(probe_work, xenbus_probe); | ||
46 | |||
47 | static DECLARE_WAIT_QUEUE_HEAD(xb_waitq); | ||
48 | |||
49 | static irqreturn_t wake_waiting(int irq, void *unused) | ||
50 | { | ||
51 | if (unlikely(xenstored_ready == 0)) { | ||
52 | xenstored_ready = 1; | ||
53 | schedule_work(&probe_work); | ||
54 | } | ||
55 | |||
56 | wake_up(&xb_waitq); | ||
57 | return IRQ_HANDLED; | ||
58 | } | ||
59 | |||
60 | static int check_indexes(XENSTORE_RING_IDX cons, XENSTORE_RING_IDX prod) | ||
61 | { | ||
62 | return ((prod - cons) <= XENSTORE_RING_SIZE); | ||
63 | } | ||
64 | |||
65 | static void *get_output_chunk(XENSTORE_RING_IDX cons, | ||
66 | XENSTORE_RING_IDX prod, | ||
67 | char *buf, uint32_t *len) | ||
68 | { | ||
69 | *len = XENSTORE_RING_SIZE - MASK_XENSTORE_IDX(prod); | ||
70 | if ((XENSTORE_RING_SIZE - (prod - cons)) < *len) | ||
71 | *len = XENSTORE_RING_SIZE - (prod - cons); | ||
72 | return buf + MASK_XENSTORE_IDX(prod); | ||
73 | } | ||
74 | |||
75 | static const void *get_input_chunk(XENSTORE_RING_IDX cons, | ||
76 | XENSTORE_RING_IDX prod, | ||
77 | const char *buf, uint32_t *len) | ||
78 | { | ||
79 | *len = XENSTORE_RING_SIZE - MASK_XENSTORE_IDX(cons); | ||
80 | if ((prod - cons) < *len) | ||
81 | *len = prod - cons; | ||
82 | return buf + MASK_XENSTORE_IDX(cons); | ||
83 | } | ||
84 | |||
85 | /** | ||
86 | * xb_write - low level write | ||
87 | * @data: buffer to send | ||
88 | * @len: length of buffer | ||
89 | * | ||
90 | * Returns 0 on success, error otherwise. | ||
91 | */ | ||
92 | int xb_write(const void *data, unsigned len) | ||
93 | { | ||
94 | struct xenstore_domain_interface *intf = xen_store_interface; | ||
95 | XENSTORE_RING_IDX cons, prod; | ||
96 | int rc; | ||
97 | |||
98 | while (len != 0) { | ||
99 | void *dst; | ||
100 | unsigned int avail; | ||
101 | |||
102 | rc = wait_event_interruptible( | ||
103 | xb_waitq, | ||
104 | (intf->req_prod - intf->req_cons) != | ||
105 | XENSTORE_RING_SIZE); | ||
106 | if (rc < 0) | ||
107 | return rc; | ||
108 | |||
109 | /* Read indexes, then verify. */ | ||
110 | cons = intf->req_cons; | ||
111 | prod = intf->req_prod; | ||
112 | if (!check_indexes(cons, prod)) { | ||
113 | intf->req_cons = intf->req_prod = 0; | ||
114 | return -EIO; | ||
115 | } | ||
116 | |||
117 | dst = get_output_chunk(cons, prod, intf->req, &avail); | ||
118 | if (avail == 0) | ||
119 | continue; | ||
120 | if (avail > len) | ||
121 | avail = len; | ||
122 | |||
123 | /* Must write data /after/ reading the consumer index. */ | ||
124 | mb(); | ||
125 | |||
126 | memcpy(dst, data, avail); | ||
127 | data += avail; | ||
128 | len -= avail; | ||
129 | |||
130 | /* Other side must not see new producer until data is there. */ | ||
131 | wmb(); | ||
132 | intf->req_prod += avail; | ||
133 | |||
134 | /* Implies mb(): other side will see the updated producer. */ | ||
135 | notify_remote_via_evtchn(xen_store_evtchn); | ||
136 | } | ||
137 | |||
138 | return 0; | ||
139 | } | ||
140 | |||
141 | int xb_data_to_read(void) | ||
142 | { | ||
143 | struct xenstore_domain_interface *intf = xen_store_interface; | ||
144 | return (intf->rsp_cons != intf->rsp_prod); | ||
145 | } | ||
146 | |||
147 | int xb_wait_for_data_to_read(void) | ||
148 | { | ||
149 | return wait_event_interruptible(xb_waitq, xb_data_to_read()); | ||
150 | } | ||
151 | |||
152 | int xb_read(void *data, unsigned len) | ||
153 | { | ||
154 | struct xenstore_domain_interface *intf = xen_store_interface; | ||
155 | XENSTORE_RING_IDX cons, prod; | ||
156 | int rc; | ||
157 | |||
158 | while (len != 0) { | ||
159 | unsigned int avail; | ||
160 | const char *src; | ||
161 | |||
162 | rc = xb_wait_for_data_to_read(); | ||
163 | if (rc < 0) | ||
164 | return rc; | ||
165 | |||
166 | /* Read indexes, then verify. */ | ||
167 | cons = intf->rsp_cons; | ||
168 | prod = intf->rsp_prod; | ||
169 | if (!check_indexes(cons, prod)) { | ||
170 | intf->rsp_cons = intf->rsp_prod = 0; | ||
171 | return -EIO; | ||
172 | } | ||
173 | |||
174 | src = get_input_chunk(cons, prod, intf->rsp, &avail); | ||
175 | if (avail == 0) | ||
176 | continue; | ||
177 | if (avail > len) | ||
178 | avail = len; | ||
179 | |||
180 | /* Must read data /after/ reading the producer index. */ | ||
181 | rmb(); | ||
182 | |||
183 | memcpy(data, src, avail); | ||
184 | data += avail; | ||
185 | len -= avail; | ||
186 | |||
187 | /* Other side must not see free space until we've copied out */ | ||
188 | mb(); | ||
189 | intf->rsp_cons += avail; | ||
190 | |||
191 | pr_debug("Finished read of %i bytes (%i to go)\n", avail, len); | ||
192 | |||
193 | /* Implies mb(): other side will see the updated consumer. */ | ||
194 | notify_remote_via_evtchn(xen_store_evtchn); | ||
195 | } | ||
196 | |||
197 | return 0; | ||
198 | } | ||
199 | |||
200 | /** | ||
201 | * xb_init_comms - Set up interrupt handler off store event channel. | ||
202 | */ | ||
203 | int xb_init_comms(void) | ||
204 | { | ||
205 | struct xenstore_domain_interface *intf = xen_store_interface; | ||
206 | int err; | ||
207 | |||
208 | if (intf->req_prod != intf->req_cons) | ||
209 | printk(KERN_ERR "XENBUS request ring is not quiescent " | ||
210 | "(%08x:%08x)!\n", intf->req_cons, intf->req_prod); | ||
211 | |||
212 | if (intf->rsp_prod != intf->rsp_cons) { | ||
213 | printk(KERN_WARNING "XENBUS response ring is not quiescent " | ||
214 | "(%08x:%08x): fixing up\n", | ||
215 | intf->rsp_cons, intf->rsp_prod); | ||
216 | intf->rsp_cons = intf->rsp_prod; | ||
217 | } | ||
218 | |||
219 | if (xenbus_irq) | ||
220 | unbind_from_irqhandler(xenbus_irq, &xb_waitq); | ||
221 | |||
222 | err = bind_evtchn_to_irqhandler( | ||
223 | xen_store_evtchn, wake_waiting, | ||
224 | 0, "xenbus", &xb_waitq); | ||
225 | if (err <= 0) { | ||
226 | printk(KERN_ERR "XENBUS request irq failed %i\n", err); | ||
227 | return err; | ||
228 | } | ||
229 | |||
230 | xenbus_irq = err; | ||
231 | |||
232 | return 0; | ||
233 | } | ||
diff --git a/drivers/xen/xenbus/xenbus_comms.h b/drivers/xen/xenbus/xenbus_comms.h new file mode 100644 index 00000000000..c21db751373 --- /dev/null +++ b/drivers/xen/xenbus/xenbus_comms.h | |||
@@ -0,0 +1,46 @@ | |||
1 | /* | ||
2 | * Private include for xenbus communications. | ||
3 | * | ||
4 | * Copyright (C) 2005 Rusty Russell, IBM Corporation | ||
5 | * | ||
6 | * This program is free software; you can redistribute it and/or | ||
7 | * modify it under the terms of the GNU General Public License version 2 | ||
8 | * as published by the Free Software Foundation; or, when distributed | ||
9 | * separately from the Linux kernel or incorporated into other | ||
10 | * software packages, subject to the following license: | ||
11 | * | ||
12 | * Permission is hereby granted, free of charge, to any person obtaining a copy | ||
13 | * of this source file (the "Software"), to deal in the Software without | ||
14 | * restriction, including without limitation the rights to use, copy, modify, | ||
15 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, | ||
16 | * and to permit persons to whom the Software is furnished to do so, subject to | ||
17 | * the following conditions: | ||
18 | * | ||
19 | * The above copyright notice and this permission notice shall be included in | ||
20 | * all copies or substantial portions of the Software. | ||
21 | * | ||
22 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | ||
23 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | ||
24 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | ||
25 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | ||
26 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | ||
27 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | ||
28 | * IN THE SOFTWARE. | ||
29 | */ | ||
30 | |||
31 | #ifndef _XENBUS_COMMS_H | ||
32 | #define _XENBUS_COMMS_H | ||
33 | |||
34 | int xs_init(void); | ||
35 | int xb_init_comms(void); | ||
36 | |||
37 | /* Low level routines. */ | ||
38 | int xb_write(const void *data, unsigned len); | ||
39 | int xb_read(void *data, unsigned len); | ||
40 | int xb_data_to_read(void); | ||
41 | int xb_wait_for_data_to_read(void); | ||
42 | int xs_input_avail(void); | ||
43 | extern struct xenstore_domain_interface *xen_store_interface; | ||
44 | extern int xen_store_evtchn; | ||
45 | |||
46 | #endif /* _XENBUS_COMMS_H */ | ||
diff --git a/drivers/xen/xenbus/xenbus_probe.c b/drivers/xen/xenbus/xenbus_probe.c new file mode 100644 index 00000000000..0b769f7c4a4 --- /dev/null +++ b/drivers/xen/xenbus/xenbus_probe.c | |||
@@ -0,0 +1,935 @@ | |||
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> | ||
43 | #include <linux/notifier.h> | ||
44 | #include <linux/kthread.h> | ||
45 | #include <linux/mutex.h> | ||
46 | #include <linux/io.h> | ||
47 | |||
48 | #include <asm/page.h> | ||
49 | #include <asm/pgtable.h> | ||
50 | #include <asm/xen/hypervisor.h> | ||
51 | #include <xen/xenbus.h> | ||
52 | #include <xen/events.h> | ||
53 | #include <xen/page.h> | ||
54 | |||
55 | #include "xenbus_comms.h" | ||
56 | #include "xenbus_probe.h" | ||
57 | |||
58 | int xen_store_evtchn; | ||
59 | struct xenstore_domain_interface *xen_store_interface; | ||
60 | static unsigned long xen_store_mfn; | ||
61 | |||
62 | static BLOCKING_NOTIFIER_HEAD(xenstore_chain); | ||
63 | |||
64 | static void wait_for_devices(struct xenbus_driver *xendrv); | ||
65 | |||
66 | static int xenbus_probe_frontend(const char *type, const char *name); | ||
67 | |||
68 | static void xenbus_dev_shutdown(struct device *_dev); | ||
69 | |||
70 | /* If something in array of ids matches this device, return it. */ | ||
71 | static const struct xenbus_device_id * | ||
72 | match_device(const struct xenbus_device_id *arr, struct xenbus_device *dev) | ||
73 | { | ||
74 | for (; *arr->devicetype != '\0'; arr++) { | ||
75 | if (!strcmp(arr->devicetype, dev->devicetype)) | ||
76 | return arr; | ||
77 | } | ||
78 | return NULL; | ||
79 | } | ||
80 | |||
81 | int xenbus_match(struct device *_dev, struct device_driver *_drv) | ||
82 | { | ||
83 | struct xenbus_driver *drv = to_xenbus_driver(_drv); | ||
84 | |||
85 | if (!drv->ids) | ||
86 | return 0; | ||
87 | |||
88 | return match_device(drv->ids, to_xenbus_device(_dev)) != NULL; | ||
89 | } | ||
90 | |||
91 | /* device/<type>/<id> => <type>-<id> */ | ||
92 | static int frontend_bus_id(char bus_id[BUS_ID_SIZE], const char *nodename) | ||
93 | { | ||
94 | nodename = strchr(nodename, '/'); | ||
95 | if (!nodename || strlen(nodename + 1) >= BUS_ID_SIZE) { | ||
96 | printk(KERN_WARNING "XENBUS: bad frontend %s\n", nodename); | ||
97 | return -EINVAL; | ||
98 | } | ||
99 | |||
100 | strlcpy(bus_id, nodename + 1, BUS_ID_SIZE); | ||
101 | if (!strchr(bus_id, '/')) { | ||
102 | printk(KERN_WARNING "XENBUS: bus_id %s no slash\n", bus_id); | ||
103 | return -EINVAL; | ||
104 | } | ||
105 | *strchr(bus_id, '/') = '-'; | ||
106 | return 0; | ||
107 | } | ||
108 | |||
109 | |||
110 | static void free_otherend_details(struct xenbus_device *dev) | ||
111 | { | ||
112 | kfree(dev->otherend); | ||
113 | dev->otherend = NULL; | ||
114 | } | ||
115 | |||
116 | |||
117 | static void free_otherend_watch(struct xenbus_device *dev) | ||
118 | { | ||
119 | if (dev->otherend_watch.node) { | ||
120 | unregister_xenbus_watch(&dev->otherend_watch); | ||
121 | kfree(dev->otherend_watch.node); | ||
122 | dev->otherend_watch.node = NULL; | ||
123 | } | ||
124 | } | ||
125 | |||
126 | |||
127 | int read_otherend_details(struct xenbus_device *xendev, | ||
128 | char *id_node, char *path_node) | ||
129 | { | ||
130 | int err = xenbus_gather(XBT_NIL, xendev->nodename, | ||
131 | id_node, "%i", &xendev->otherend_id, | ||
132 | path_node, NULL, &xendev->otherend, | ||
133 | NULL); | ||
134 | if (err) { | ||
135 | xenbus_dev_fatal(xendev, err, | ||
136 | "reading other end details from %s", | ||
137 | xendev->nodename); | ||
138 | return err; | ||
139 | } | ||
140 | if (strlen(xendev->otherend) == 0 || | ||
141 | !xenbus_exists(XBT_NIL, xendev->otherend, "")) { | ||
142 | xenbus_dev_fatal(xendev, -ENOENT, | ||
143 | "unable to read other end from %s. " | ||
144 | "missing or inaccessible.", | ||
145 | xendev->nodename); | ||
146 | free_otherend_details(xendev); | ||
147 | return -ENOENT; | ||
148 | } | ||
149 | |||
150 | return 0; | ||
151 | } | ||
152 | |||
153 | |||
154 | static int read_backend_details(struct xenbus_device *xendev) | ||
155 | { | ||
156 | return read_otherend_details(xendev, "backend-id", "backend"); | ||
157 | } | ||
158 | |||
159 | |||
160 | /* Bus type for frontend drivers. */ | ||
161 | static struct xen_bus_type xenbus_frontend = { | ||
162 | .root = "device", | ||
163 | .levels = 2, /* device/type/<id> */ | ||
164 | .get_bus_id = frontend_bus_id, | ||
165 | .probe = xenbus_probe_frontend, | ||
166 | .bus = { | ||
167 | .name = "xen", | ||
168 | .match = xenbus_match, | ||
169 | .probe = xenbus_dev_probe, | ||
170 | .remove = xenbus_dev_remove, | ||
171 | .shutdown = xenbus_dev_shutdown, | ||
172 | }, | ||
173 | }; | ||
174 | |||
175 | static void otherend_changed(struct xenbus_watch *watch, | ||
176 | const char **vec, unsigned int len) | ||
177 | { | ||
178 | struct xenbus_device *dev = | ||
179 | container_of(watch, struct xenbus_device, otherend_watch); | ||
180 | struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver); | ||
181 | enum xenbus_state state; | ||
182 | |||
183 | /* Protect us against watches firing on old details when the otherend | ||
184 | details change, say immediately after a resume. */ | ||
185 | if (!dev->otherend || | ||
186 | strncmp(dev->otherend, vec[XS_WATCH_PATH], | ||
187 | strlen(dev->otherend))) { | ||
188 | dev_dbg(&dev->dev, "Ignoring watch at %s", vec[XS_WATCH_PATH]); | ||
189 | return; | ||
190 | } | ||
191 | |||
192 | state = xenbus_read_driver_state(dev->otherend); | ||
193 | |||
194 | dev_dbg(&dev->dev, "state is %d, (%s), %s, %s", | ||
195 | state, xenbus_strstate(state), dev->otherend_watch.node, | ||
196 | vec[XS_WATCH_PATH]); | ||
197 | |||
198 | /* | ||
199 | * Ignore xenbus transitions during shutdown. This prevents us doing | ||
200 | * work that can fail e.g., when the rootfs is gone. | ||
201 | */ | ||
202 | if (system_state > SYSTEM_RUNNING) { | ||
203 | struct xen_bus_type *bus = bus; | ||
204 | bus = container_of(dev->dev.bus, struct xen_bus_type, bus); | ||
205 | /* If we're frontend, drive the state machine to Closed. */ | ||
206 | /* This should cause the backend to release our resources. */ | ||
207 | if ((bus == &xenbus_frontend) && (state == XenbusStateClosing)) | ||
208 | xenbus_frontend_closed(dev); | ||
209 | return; | ||
210 | } | ||
211 | |||
212 | if (drv->otherend_changed) | ||
213 | drv->otherend_changed(dev, state); | ||
214 | } | ||
215 | |||
216 | |||
217 | static int talk_to_otherend(struct xenbus_device *dev) | ||
218 | { | ||
219 | struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver); | ||
220 | |||
221 | free_otherend_watch(dev); | ||
222 | free_otherend_details(dev); | ||
223 | |||
224 | return drv->read_otherend_details(dev); | ||
225 | } | ||
226 | |||
227 | |||
228 | static int watch_otherend(struct xenbus_device *dev) | ||
229 | { | ||
230 | return xenbus_watch_pathfmt(dev, &dev->otherend_watch, otherend_changed, | ||
231 | "%s/%s", dev->otherend, "state"); | ||
232 | } | ||
233 | |||
234 | |||
235 | int xenbus_dev_probe(struct device *_dev) | ||
236 | { | ||
237 | struct xenbus_device *dev = to_xenbus_device(_dev); | ||
238 | struct xenbus_driver *drv = to_xenbus_driver(_dev->driver); | ||
239 | const struct xenbus_device_id *id; | ||
240 | int err; | ||
241 | |||
242 | DPRINTK("%s", dev->nodename); | ||
243 | |||
244 | if (!drv->probe) { | ||
245 | err = -ENODEV; | ||
246 | goto fail; | ||
247 | } | ||
248 | |||
249 | id = match_device(drv->ids, dev); | ||
250 | if (!id) { | ||
251 | err = -ENODEV; | ||
252 | goto fail; | ||
253 | } | ||
254 | |||
255 | err = talk_to_otherend(dev); | ||
256 | if (err) { | ||
257 | dev_warn(&dev->dev, "talk_to_otherend on %s failed.\n", | ||
258 | dev->nodename); | ||
259 | return err; | ||
260 | } | ||
261 | |||
262 | err = drv->probe(dev, id); | ||
263 | if (err) | ||
264 | goto fail; | ||
265 | |||
266 | err = watch_otherend(dev); | ||
267 | if (err) { | ||
268 | dev_warn(&dev->dev, "watch_otherend on %s failed.\n", | ||
269 | dev->nodename); | ||
270 | return err; | ||
271 | } | ||
272 | |||
273 | return 0; | ||
274 | fail: | ||
275 | xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename); | ||
276 | xenbus_switch_state(dev, XenbusStateClosed); | ||
277 | return -ENODEV; | ||
278 | } | ||
279 | |||
280 | int xenbus_dev_remove(struct device *_dev) | ||
281 | { | ||
282 | struct xenbus_device *dev = to_xenbus_device(_dev); | ||
283 | struct xenbus_driver *drv = to_xenbus_driver(_dev->driver); | ||
284 | |||
285 | DPRINTK("%s", dev->nodename); | ||
286 | |||
287 | free_otherend_watch(dev); | ||
288 | free_otherend_details(dev); | ||
289 | |||
290 | if (drv->remove) | ||
291 | drv->remove(dev); | ||
292 | |||
293 | xenbus_switch_state(dev, XenbusStateClosed); | ||
294 | return 0; | ||
295 | } | ||
296 | |||
297 | static void xenbus_dev_shutdown(struct device *_dev) | ||
298 | { | ||
299 | struct xenbus_device *dev = to_xenbus_device(_dev); | ||
300 | unsigned long timeout = 5*HZ; | ||
301 | |||
302 | DPRINTK("%s", dev->nodename); | ||
303 | |||
304 | get_device(&dev->dev); | ||
305 | if (dev->state != XenbusStateConnected) { | ||
306 | printk(KERN_INFO "%s: %s: %s != Connected, skipping\n", __func__, | ||
307 | dev->nodename, xenbus_strstate(dev->state)); | ||
308 | goto out; | ||
309 | } | ||
310 | xenbus_switch_state(dev, XenbusStateClosing); | ||
311 | timeout = wait_for_completion_timeout(&dev->down, timeout); | ||
312 | if (!timeout) | ||
313 | printk(KERN_INFO "%s: %s timeout closing device\n", | ||
314 | __func__, dev->nodename); | ||
315 | out: | ||
316 | put_device(&dev->dev); | ||
317 | } | ||
318 | |||
319 | int xenbus_register_driver_common(struct xenbus_driver *drv, | ||
320 | struct xen_bus_type *bus, | ||
321 | struct module *owner, | ||
322 | const char *mod_name) | ||
323 | { | ||
324 | drv->driver.name = drv->name; | ||
325 | drv->driver.bus = &bus->bus; | ||
326 | drv->driver.owner = owner; | ||
327 | drv->driver.mod_name = mod_name; | ||
328 | |||
329 | return driver_register(&drv->driver); | ||
330 | } | ||
331 | |||
332 | int __xenbus_register_frontend(struct xenbus_driver *drv, | ||
333 | struct module *owner, const char *mod_name) | ||
334 | { | ||
335 | int ret; | ||
336 | |||
337 | drv->read_otherend_details = read_backend_details; | ||
338 | |||
339 | ret = xenbus_register_driver_common(drv, &xenbus_frontend, | ||
340 | owner, mod_name); | ||
341 | if (ret) | ||
342 | return ret; | ||
343 | |||
344 | /* If this driver is loaded as a module wait for devices to attach. */ | ||
345 | wait_for_devices(drv); | ||
346 | |||
347 | return 0; | ||
348 | } | ||
349 | EXPORT_SYMBOL_GPL(__xenbus_register_frontend); | ||
350 | |||
351 | void xenbus_unregister_driver(struct xenbus_driver *drv) | ||
352 | { | ||
353 | driver_unregister(&drv->driver); | ||
354 | } | ||
355 | EXPORT_SYMBOL_GPL(xenbus_unregister_driver); | ||
356 | |||
357 | struct xb_find_info | ||
358 | { | ||
359 | struct xenbus_device *dev; | ||
360 | const char *nodename; | ||
361 | }; | ||
362 | |||
363 | static int cmp_dev(struct device *dev, void *data) | ||
364 | { | ||
365 | struct xenbus_device *xendev = to_xenbus_device(dev); | ||
366 | struct xb_find_info *info = data; | ||
367 | |||
368 | if (!strcmp(xendev->nodename, info->nodename)) { | ||
369 | info->dev = xendev; | ||
370 | get_device(dev); | ||
371 | return 1; | ||
372 | } | ||
373 | return 0; | ||
374 | } | ||
375 | |||
376 | struct xenbus_device *xenbus_device_find(const char *nodename, | ||
377 | struct bus_type *bus) | ||
378 | { | ||
379 | struct xb_find_info info = { .dev = NULL, .nodename = nodename }; | ||
380 | |||
381 | bus_for_each_dev(bus, NULL, &info, cmp_dev); | ||
382 | return info.dev; | ||
383 | } | ||
384 | |||
385 | static int cleanup_dev(struct device *dev, void *data) | ||
386 | { | ||
387 | struct xenbus_device *xendev = to_xenbus_device(dev); | ||
388 | struct xb_find_info *info = data; | ||
389 | int len = strlen(info->nodename); | ||
390 | |||
391 | DPRINTK("%s", info->nodename); | ||
392 | |||
393 | /* Match the info->nodename path, or any subdirectory of that path. */ | ||
394 | if (strncmp(xendev->nodename, info->nodename, len)) | ||
395 | return 0; | ||
396 | |||
397 | /* If the node name is longer, ensure it really is a subdirectory. */ | ||
398 | if ((strlen(xendev->nodename) > len) && (xendev->nodename[len] != '/')) | ||
399 | return 0; | ||
400 | |||
401 | info->dev = xendev; | ||
402 | get_device(dev); | ||
403 | return 1; | ||
404 | } | ||
405 | |||
406 | static void xenbus_cleanup_devices(const char *path, struct bus_type *bus) | ||
407 | { | ||
408 | struct xb_find_info info = { .nodename = path }; | ||
409 | |||
410 | do { | ||
411 | info.dev = NULL; | ||
412 | bus_for_each_dev(bus, NULL, &info, cleanup_dev); | ||
413 | if (info.dev) { | ||
414 | device_unregister(&info.dev->dev); | ||
415 | put_device(&info.dev->dev); | ||
416 | } | ||
417 | } while (info.dev); | ||
418 | } | ||
419 | |||
420 | static void xenbus_dev_release(struct device *dev) | ||
421 | { | ||
422 | if (dev) | ||
423 | kfree(to_xenbus_device(dev)); | ||
424 | } | ||
425 | |||
426 | static ssize_t xendev_show_nodename(struct device *dev, | ||
427 | struct device_attribute *attr, char *buf) | ||
428 | { | ||
429 | return sprintf(buf, "%s\n", to_xenbus_device(dev)->nodename); | ||
430 | } | ||
431 | DEVICE_ATTR(nodename, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_nodename, NULL); | ||
432 | |||
433 | static ssize_t xendev_show_devtype(struct device *dev, | ||
434 | struct device_attribute *attr, char *buf) | ||
435 | { | ||
436 | return sprintf(buf, "%s\n", to_xenbus_device(dev)->devicetype); | ||
437 | } | ||
438 | DEVICE_ATTR(devtype, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_devtype, NULL); | ||
439 | |||
440 | |||
441 | int xenbus_probe_node(struct xen_bus_type *bus, | ||
442 | const char *type, | ||
443 | const char *nodename) | ||
444 | { | ||
445 | int err; | ||
446 | struct xenbus_device *xendev; | ||
447 | size_t stringlen; | ||
448 | char *tmpstring; | ||
449 | |||
450 | enum xenbus_state state = xenbus_read_driver_state(nodename); | ||
451 | |||
452 | if (state != XenbusStateInitialising) { | ||
453 | /* Device is not new, so ignore it. This can happen if a | ||
454 | device is going away after switching to Closed. */ | ||
455 | return 0; | ||
456 | } | ||
457 | |||
458 | stringlen = strlen(nodename) + 1 + strlen(type) + 1; | ||
459 | xendev = kzalloc(sizeof(*xendev) + stringlen, GFP_KERNEL); | ||
460 | if (!xendev) | ||
461 | return -ENOMEM; | ||
462 | |||
463 | xendev->state = XenbusStateInitialising; | ||
464 | |||
465 | /* Copy the strings into the extra space. */ | ||
466 | |||
467 | tmpstring = (char *)(xendev + 1); | ||
468 | strcpy(tmpstring, nodename); | ||
469 | xendev->nodename = tmpstring; | ||
470 | |||
471 | tmpstring += strlen(tmpstring) + 1; | ||
472 | strcpy(tmpstring, type); | ||
473 | xendev->devicetype = tmpstring; | ||
474 | init_completion(&xendev->down); | ||
475 | |||
476 | xendev->dev.bus = &bus->bus; | ||
477 | xendev->dev.release = xenbus_dev_release; | ||
478 | |||
479 | err = bus->get_bus_id(xendev->dev.bus_id, xendev->nodename); | ||
480 | if (err) | ||
481 | goto fail; | ||
482 | |||
483 | /* Register with generic device framework. */ | ||
484 | err = device_register(&xendev->dev); | ||
485 | if (err) | ||
486 | goto fail; | ||
487 | |||
488 | err = device_create_file(&xendev->dev, &dev_attr_nodename); | ||
489 | if (err) | ||
490 | goto fail_unregister; | ||
491 | |||
492 | err = device_create_file(&xendev->dev, &dev_attr_devtype); | ||
493 | if (err) | ||
494 | goto fail_remove_file; | ||
495 | |||
496 | return 0; | ||
497 | fail_remove_file: | ||
498 | device_remove_file(&xendev->dev, &dev_attr_nodename); | ||
499 | fail_unregister: | ||
500 | device_unregister(&xendev->dev); | ||
501 | fail: | ||
502 | kfree(xendev); | ||
503 | return err; | ||
504 | } | ||
505 | |||
506 | /* device/<typename>/<name> */ | ||
507 | static int xenbus_probe_frontend(const char *type, const char *name) | ||
508 | { | ||
509 | char *nodename; | ||
510 | int err; | ||
511 | |||
512 | nodename = kasprintf(GFP_KERNEL, "%s/%s/%s", | ||
513 | xenbus_frontend.root, type, name); | ||
514 | if (!nodename) | ||
515 | return -ENOMEM; | ||
516 | |||
517 | DPRINTK("%s", nodename); | ||
518 | |||
519 | err = xenbus_probe_node(&xenbus_frontend, type, nodename); | ||
520 | kfree(nodename); | ||
521 | return err; | ||
522 | } | ||
523 | |||
524 | static int xenbus_probe_device_type(struct xen_bus_type *bus, const char *type) | ||
525 | { | ||
526 | int err = 0; | ||
527 | char **dir; | ||
528 | unsigned int dir_n = 0; | ||
529 | int i; | ||
530 | |||
531 | dir = xenbus_directory(XBT_NIL, bus->root, type, &dir_n); | ||
532 | if (IS_ERR(dir)) | ||
533 | return PTR_ERR(dir); | ||
534 | |||
535 | for (i = 0; i < dir_n; i++) { | ||
536 | err = bus->probe(type, dir[i]); | ||
537 | if (err) | ||
538 | break; | ||
539 | } | ||
540 | kfree(dir); | ||
541 | return err; | ||
542 | } | ||
543 | |||
544 | int xenbus_probe_devices(struct xen_bus_type *bus) | ||
545 | { | ||
546 | int err = 0; | ||
547 | char **dir; | ||
548 | unsigned int i, dir_n; | ||
549 | |||
550 | dir = xenbus_directory(XBT_NIL, bus->root, "", &dir_n); | ||
551 | if (IS_ERR(dir)) | ||
552 | return PTR_ERR(dir); | ||
553 | |||
554 | for (i = 0; i < dir_n; i++) { | ||
555 | err = xenbus_probe_device_type(bus, dir[i]); | ||
556 | if (err) | ||
557 | break; | ||
558 | } | ||
559 | kfree(dir); | ||
560 | return err; | ||
561 | } | ||
562 | |||
563 | static unsigned int char_count(const char *str, char c) | ||
564 | { | ||
565 | unsigned int i, ret = 0; | ||
566 | |||
567 | for (i = 0; str[i]; i++) | ||
568 | if (str[i] == c) | ||
569 | ret++; | ||
570 | return ret; | ||
571 | } | ||
572 | |||
573 | static int strsep_len(const char *str, char c, unsigned int len) | ||
574 | { | ||
575 | unsigned int i; | ||
576 | |||
577 | for (i = 0; str[i]; i++) | ||
578 | if (str[i] == c) { | ||
579 | if (len == 0) | ||
580 | return i; | ||
581 | len--; | ||
582 | } | ||
583 | return (len == 0) ? i : -ERANGE; | ||
584 | } | ||
585 | |||
586 | void xenbus_dev_changed(const char *node, struct xen_bus_type *bus) | ||
587 | { | ||
588 | int exists, rootlen; | ||
589 | struct xenbus_device *dev; | ||
590 | char type[BUS_ID_SIZE]; | ||
591 | const char *p, *root; | ||
592 | |||
593 | if (char_count(node, '/') < 2) | ||
594 | return; | ||
595 | |||
596 | exists = xenbus_exists(XBT_NIL, node, ""); | ||
597 | if (!exists) { | ||
598 | xenbus_cleanup_devices(node, &bus->bus); | ||
599 | return; | ||
600 | } | ||
601 | |||
602 | /* backend/<type>/... or device/<type>/... */ | ||
603 | p = strchr(node, '/') + 1; | ||
604 | snprintf(type, BUS_ID_SIZE, "%.*s", (int)strcspn(p, "/"), p); | ||
605 | type[BUS_ID_SIZE-1] = '\0'; | ||
606 | |||
607 | rootlen = strsep_len(node, '/', bus->levels); | ||
608 | if (rootlen < 0) | ||
609 | return; | ||
610 | root = kasprintf(GFP_KERNEL, "%.*s", rootlen, node); | ||
611 | if (!root) | ||
612 | return; | ||
613 | |||
614 | dev = xenbus_device_find(root, &bus->bus); | ||
615 | if (!dev) | ||
616 | xenbus_probe_node(bus, type, root); | ||
617 | else | ||
618 | put_device(&dev->dev); | ||
619 | |||
620 | kfree(root); | ||
621 | } | ||
622 | |||
623 | static void frontend_changed(struct xenbus_watch *watch, | ||
624 | const char **vec, unsigned int len) | ||
625 | { | ||
626 | DPRINTK(""); | ||
627 | |||
628 | xenbus_dev_changed(vec[XS_WATCH_PATH], &xenbus_frontend); | ||
629 | } | ||
630 | |||
631 | /* We watch for devices appearing and vanishing. */ | ||
632 | static struct xenbus_watch fe_watch = { | ||
633 | .node = "device", | ||
634 | .callback = frontend_changed, | ||
635 | }; | ||
636 | |||
637 | static int suspend_dev(struct device *dev, void *data) | ||
638 | { | ||
639 | int err = 0; | ||
640 | struct xenbus_driver *drv; | ||
641 | struct xenbus_device *xdev; | ||
642 | |||
643 | DPRINTK(""); | ||
644 | |||
645 | if (dev->driver == NULL) | ||
646 | return 0; | ||
647 | drv = to_xenbus_driver(dev->driver); | ||
648 | xdev = container_of(dev, struct xenbus_device, dev); | ||
649 | if (drv->suspend) | ||
650 | err = drv->suspend(xdev); | ||
651 | if (err) | ||
652 | printk(KERN_WARNING | ||
653 | "xenbus: suspend %s failed: %i\n", dev->bus_id, err); | ||
654 | return 0; | ||
655 | } | ||
656 | |||
657 | static int suspend_cancel_dev(struct device *dev, void *data) | ||
658 | { | ||
659 | int err = 0; | ||
660 | struct xenbus_driver *drv; | ||
661 | struct xenbus_device *xdev; | ||
662 | |||
663 | DPRINTK(""); | ||
664 | |||
665 | if (dev->driver == NULL) | ||
666 | return 0; | ||
667 | drv = to_xenbus_driver(dev->driver); | ||
668 | xdev = container_of(dev, struct xenbus_device, dev); | ||
669 | if (drv->suspend_cancel) | ||
670 | err = drv->suspend_cancel(xdev); | ||
671 | if (err) | ||
672 | printk(KERN_WARNING | ||
673 | "xenbus: suspend_cancel %s failed: %i\n", | ||
674 | dev->bus_id, err); | ||
675 | return 0; | ||
676 | } | ||
677 | |||
678 | static int resume_dev(struct device *dev, void *data) | ||
679 | { | ||
680 | int err; | ||
681 | struct xenbus_driver *drv; | ||
682 | struct xenbus_device *xdev; | ||
683 | |||
684 | DPRINTK(""); | ||
685 | |||
686 | if (dev->driver == NULL) | ||
687 | return 0; | ||
688 | |||
689 | drv = to_xenbus_driver(dev->driver); | ||
690 | xdev = container_of(dev, struct xenbus_device, dev); | ||
691 | |||
692 | err = talk_to_otherend(xdev); | ||
693 | if (err) { | ||
694 | printk(KERN_WARNING | ||
695 | "xenbus: resume (talk_to_otherend) %s failed: %i\n", | ||
696 | dev->bus_id, err); | ||
697 | return err; | ||
698 | } | ||
699 | |||
700 | xdev->state = XenbusStateInitialising; | ||
701 | |||
702 | if (drv->resume) { | ||
703 | err = drv->resume(xdev); | ||
704 | if (err) { | ||
705 | printk(KERN_WARNING | ||
706 | "xenbus: resume %s failed: %i\n", | ||
707 | dev->bus_id, err); | ||
708 | return err; | ||
709 | } | ||
710 | } | ||
711 | |||
712 | err = watch_otherend(xdev); | ||
713 | if (err) { | ||
714 | printk(KERN_WARNING | ||
715 | "xenbus_probe: resume (watch_otherend) %s failed: " | ||
716 | "%d.\n", dev->bus_id, err); | ||
717 | return err; | ||
718 | } | ||
719 | |||
720 | return 0; | ||
721 | } | ||
722 | |||
723 | void xenbus_suspend(void) | ||
724 | { | ||
725 | DPRINTK(""); | ||
726 | |||
727 | bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, suspend_dev); | ||
728 | xenbus_backend_suspend(suspend_dev); | ||
729 | xs_suspend(); | ||
730 | } | ||
731 | EXPORT_SYMBOL_GPL(xenbus_suspend); | ||
732 | |||
733 | void xenbus_resume(void) | ||
734 | { | ||
735 | xb_init_comms(); | ||
736 | xs_resume(); | ||
737 | bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, resume_dev); | ||
738 | xenbus_backend_resume(resume_dev); | ||
739 | } | ||
740 | EXPORT_SYMBOL_GPL(xenbus_resume); | ||
741 | |||
742 | void xenbus_suspend_cancel(void) | ||
743 | { | ||
744 | xs_suspend_cancel(); | ||
745 | bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, suspend_cancel_dev); | ||
746 | xenbus_backend_resume(suspend_cancel_dev); | ||
747 | } | ||
748 | EXPORT_SYMBOL_GPL(xenbus_suspend_cancel); | ||
749 | |||
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 | |||
758 | if (xenstored_ready > 0) | ||
759 | ret = nb->notifier_call(nb, 0, NULL); | ||
760 | else | ||
761 | blocking_notifier_chain_register(&xenstore_chain, nb); | ||
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 | { | ||
775 | BUG_ON((xenstored_ready <= 0)); | ||
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 | } | ||
785 | |||
786 | static int __init xenbus_probe_init(void) | ||
787 | { | ||
788 | int err = 0; | ||
789 | |||
790 | DPRINTK(""); | ||
791 | |||
792 | err = -ENODEV; | ||
793 | if (!is_running_on_xen()) | ||
794 | goto out_error; | ||
795 | |||
796 | /* Register ourselves with the kernel bus subsystem */ | ||
797 | err = bus_register(&xenbus_frontend.bus); | ||
798 | if (err) | ||
799 | goto out_error; | ||
800 | |||
801 | err = xenbus_backend_bus_register(); | ||
802 | if (err) | ||
803 | goto out_unreg_front; | ||
804 | |||
805 | /* | ||
806 | * Domain0 doesn't have a store_evtchn or store_mfn yet. | ||
807 | */ | ||
808 | if (is_initial_xendomain()) { | ||
809 | /* dom0 not yet supported */ | ||
810 | } else { | ||
811 | xenstored_ready = 1; | ||
812 | xen_store_evtchn = xen_start_info->store_evtchn; | ||
813 | xen_store_mfn = xen_start_info->store_mfn; | ||
814 | } | ||
815 | xen_store_interface = mfn_to_virt(xen_store_mfn); | ||
816 | |||
817 | /* Initialize the interface to xenstore. */ | ||
818 | err = xs_init(); | ||
819 | if (err) { | ||
820 | printk(KERN_WARNING | ||
821 | "XENBUS: Error initializing xenstore comms: %i\n", err); | ||
822 | goto out_unreg_back; | ||
823 | } | ||
824 | |||
825 | if (!is_initial_xendomain()) | ||
826 | xenbus_probe(NULL); | ||
827 | |||
828 | return 0; | ||
829 | |||
830 | out_unreg_back: | ||
831 | xenbus_backend_bus_unregister(); | ||
832 | |||
833 | out_unreg_front: | ||
834 | bus_unregister(&xenbus_frontend.bus); | ||
835 | |||
836 | out_error: | ||
837 | return err; | ||
838 | } | ||
839 | |||
840 | postcore_initcall(xenbus_probe_init); | ||
841 | |||
842 | MODULE_LICENSE("GPL"); | ||
843 | |||
844 | static int is_disconnected_device(struct device *dev, void *data) | ||
845 | { | ||
846 | struct xenbus_device *xendev = to_xenbus_device(dev); | ||
847 | struct device_driver *drv = data; | ||
848 | |||
849 | /* | ||
850 | * A device with no driver will never connect. We care only about | ||
851 | * devices which should currently be in the process of connecting. | ||
852 | */ | ||
853 | if (!dev->driver) | ||
854 | return 0; | ||
855 | |||
856 | /* Is this search limited to a particular driver? */ | ||
857 | if (drv && (dev->driver != drv)) | ||
858 | return 0; | ||
859 | |||
860 | return (xendev->state != XenbusStateConnected); | ||
861 | } | ||
862 | |||
863 | static int exists_disconnected_device(struct device_driver *drv) | ||
864 | { | ||
865 | return bus_for_each_dev(&xenbus_frontend.bus, NULL, drv, | ||
866 | is_disconnected_device); | ||
867 | } | ||
868 | |||
869 | static int print_device_status(struct device *dev, void *data) | ||
870 | { | ||
871 | struct xenbus_device *xendev = to_xenbus_device(dev); | ||
872 | struct device_driver *drv = data; | ||
873 | |||
874 | /* Is this operation limited to a particular driver? */ | ||
875 | if (drv && (dev->driver != drv)) | ||
876 | return 0; | ||
877 | |||
878 | if (!dev->driver) { | ||
879 | /* Information only: is this too noisy? */ | ||
880 | printk(KERN_INFO "XENBUS: Device with no driver: %s\n", | ||
881 | xendev->nodename); | ||
882 | } else if (xendev->state != XenbusStateConnected) { | ||
883 | printk(KERN_WARNING "XENBUS: Timeout connecting " | ||
884 | "to device: %s (state %d)\n", | ||
885 | xendev->nodename, xendev->state); | ||
886 | } | ||
887 | |||
888 | return 0; | ||
889 | } | ||
890 | |||
891 | /* We only wait for device setup after most initcalls have run. */ | ||
892 | static int ready_to_wait_for_devices; | ||
893 | |||
894 | /* | ||
895 | * On a 10 second timeout, wait for all devices currently configured. We need | ||
896 | * to do this to guarantee that the filesystems and / or network devices | ||
897 | * needed for boot are available, before we can allow the boot to proceed. | ||
898 | * | ||
899 | * This needs to be on a late_initcall, to happen after the frontend device | ||
900 | * drivers have been initialised, but before the root fs is mounted. | ||
901 | * | ||
902 | * A possible improvement here would be to have the tools add a per-device | ||
903 | * flag to the store entry, indicating whether it is needed at boot time. | ||
904 | * This would allow people who knew what they were doing to accelerate their | ||
905 | * boot slightly, but of course needs tools or manual intervention to set up | ||
906 | * those flags correctly. | ||
907 | */ | ||
908 | static void wait_for_devices(struct xenbus_driver *xendrv) | ||
909 | { | ||
910 | unsigned long timeout = jiffies + 10*HZ; | ||
911 | struct device_driver *drv = xendrv ? &xendrv->driver : NULL; | ||
912 | |||
913 | if (!ready_to_wait_for_devices || !is_running_on_xen()) | ||
914 | return; | ||
915 | |||
916 | while (exists_disconnected_device(drv)) { | ||
917 | if (time_after(jiffies, timeout)) | ||
918 | break; | ||
919 | schedule_timeout_interruptible(HZ/10); | ||
920 | } | ||
921 | |||
922 | bus_for_each_dev(&xenbus_frontend.bus, NULL, drv, | ||
923 | print_device_status); | ||
924 | } | ||
925 | |||
926 | #ifndef MODULE | ||
927 | static int __init boot_wait_for_devices(void) | ||
928 | { | ||
929 | ready_to_wait_for_devices = 1; | ||
930 | wait_for_devices(NULL); | ||
931 | return 0; | ||
932 | } | ||
933 | |||
934 | late_initcall(boot_wait_for_devices); | ||
935 | #endif | ||
diff --git a/drivers/xen/xenbus/xenbus_probe.h b/drivers/xen/xenbus/xenbus_probe.h new file mode 100644 index 00000000000..e09b19415a4 --- /dev/null +++ b/drivers/xen/xenbus/xenbus_probe.h | |||
@@ -0,0 +1,74 @@ | |||
1 | /****************************************************************************** | ||
2 | * xenbus_probe.h | ||
3 | * | ||
4 | * Talks to Xen Store to figure out what devices we have. | ||
5 | * | ||
6 | * Copyright (C) 2005 Rusty Russell, IBM Corporation | ||
7 | * Copyright (C) 2005 XenSource Ltd. | ||
8 | * | ||
9 | * This program is free software; you can redistribute it and/or | ||
10 | * modify it under the terms of the GNU General Public License version 2 | ||
11 | * as published by the Free Software Foundation; or, when distributed | ||
12 | * separately from the Linux kernel or incorporated into other | ||
13 | * software packages, subject to the following license: | ||
14 | * | ||
15 | * Permission is hereby granted, free of charge, to any person obtaining a copy | ||
16 | * of this source file (the "Software"), to deal in the Software without | ||
17 | * restriction, including without limitation the rights to use, copy, modify, | ||
18 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, | ||
19 | * and to permit persons to whom the Software is furnished to do so, subject to | ||
20 | * the following conditions: | ||
21 | * | ||
22 | * The above copyright notice and this permission notice shall be included in | ||
23 | * all copies or substantial portions of the Software. | ||
24 | * | ||
25 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | ||
26 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | ||
27 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | ||
28 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | ||
29 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | ||
30 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | ||
31 | * IN THE SOFTWARE. | ||
32 | */ | ||
33 | |||
34 | #ifndef _XENBUS_PROBE_H | ||
35 | #define _XENBUS_PROBE_H | ||
36 | |||
37 | #ifdef CONFIG_XEN_BACKEND | ||
38 | extern void xenbus_backend_suspend(int (*fn)(struct device *, void *)); | ||
39 | extern void xenbus_backend_resume(int (*fn)(struct device *, void *)); | ||
40 | extern void xenbus_backend_probe_and_watch(void); | ||
41 | extern int xenbus_backend_bus_register(void); | ||
42 | extern void xenbus_backend_bus_unregister(void); | ||
43 | #else | ||
44 | static inline void xenbus_backend_suspend(int (*fn)(struct device *, void *)) {} | ||
45 | static inline void xenbus_backend_resume(int (*fn)(struct device *, void *)) {} | ||
46 | static inline void xenbus_backend_probe_and_watch(void) {} | ||
47 | static inline int xenbus_backend_bus_register(void) { return 0; } | ||
48 | static inline void xenbus_backend_bus_unregister(void) {} | ||
49 | #endif | ||
50 | |||
51 | struct xen_bus_type | ||
52 | { | ||
53 | char *root; | ||
54 | unsigned int levels; | ||
55 | int (*get_bus_id)(char bus_id[BUS_ID_SIZE], const char *nodename); | ||
56 | int (*probe)(const char *type, const char *dir); | ||
57 | struct bus_type bus; | ||
58 | }; | ||
59 | |||
60 | extern int xenbus_match(struct device *_dev, struct device_driver *_drv); | ||
61 | extern int xenbus_dev_probe(struct device *_dev); | ||
62 | extern int xenbus_dev_remove(struct device *_dev); | ||
63 | extern int xenbus_register_driver_common(struct xenbus_driver *drv, | ||
64 | struct xen_bus_type *bus, | ||
65 | struct module *owner, | ||
66 | const char *mod_name); | ||
67 | extern int xenbus_probe_node(struct xen_bus_type *bus, | ||
68 | const char *type, | ||
69 | const char *nodename); | ||
70 | extern int xenbus_probe_devices(struct xen_bus_type *bus); | ||
71 | |||
72 | extern void xenbus_dev_changed(const char *node, struct xen_bus_type *bus); | ||
73 | |||
74 | #endif | ||
diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c new file mode 100644 index 00000000000..9e943fbce81 --- /dev/null +++ b/drivers/xen/xenbus/xenbus_xs.c | |||
@@ -0,0 +1,861 @@ | |||
1 | /****************************************************************************** | ||
2 | * xenbus_xs.c | ||
3 | * | ||
4 | * This is the kernel equivalent of the "xs" library. We don't need everything | ||
5 | * and we use xenbus_comms for communication. | ||
6 | * | ||
7 | * Copyright (C) 2005 Rusty Russell, IBM Corporation | ||
8 | * | ||
9 | * This program is free software; you can redistribute it and/or | ||
10 | * modify it under the terms of the GNU General Public License version 2 | ||
11 | * as published by the Free Software Foundation; or, when distributed | ||
12 | * separately from the Linux kernel or incorporated into other | ||
13 | * software packages, subject to the following license: | ||
14 | * | ||
15 | * Permission is hereby granted, free of charge, to any person obtaining a copy | ||
16 | * of this source file (the "Software"), to deal in the Software without | ||
17 | * restriction, including without limitation the rights to use, copy, modify, | ||
18 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, | ||
19 | * and to permit persons to whom the Software is furnished to do so, subject to | ||
20 | * the following conditions: | ||
21 | * | ||
22 | * The above copyright notice and this permission notice shall be included in | ||
23 | * all copies or substantial portions of the Software. | ||
24 | * | ||
25 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | ||
26 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | ||
27 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE | ||
28 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER | ||
29 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING | ||
30 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS | ||
31 | * IN THE SOFTWARE. | ||
32 | */ | ||
33 | |||
34 | #include <linux/unistd.h> | ||
35 | #include <linux/errno.h> | ||
36 | #include <linux/types.h> | ||
37 | #include <linux/uio.h> | ||
38 | #include <linux/kernel.h> | ||
39 | #include <linux/string.h> | ||
40 | #include <linux/err.h> | ||
41 | #include <linux/slab.h> | ||
42 | #include <linux/fcntl.h> | ||
43 | #include <linux/kthread.h> | ||
44 | #include <linux/rwsem.h> | ||
45 | #include <linux/module.h> | ||
46 | #include <linux/mutex.h> | ||
47 | #include <xen/xenbus.h> | ||
48 | #include "xenbus_comms.h" | ||
49 | |||
50 | struct xs_stored_msg { | ||
51 | struct list_head list; | ||
52 | |||
53 | struct xsd_sockmsg hdr; | ||
54 | |||
55 | union { | ||
56 | /* Queued replies. */ | ||
57 | struct { | ||
58 | char *body; | ||
59 | } reply; | ||
60 | |||
61 | /* Queued watch events. */ | ||
62 | struct { | ||
63 | struct xenbus_watch *handle; | ||
64 | char **vec; | ||
65 | unsigned int vec_size; | ||
66 | } watch; | ||
67 | } u; | ||
68 | }; | ||
69 | |||
70 | struct xs_handle { | ||
71 | /* A list of replies. Currently only one will ever be outstanding. */ | ||
72 | struct list_head reply_list; | ||
73 | spinlock_t reply_lock; | ||
74 | wait_queue_head_t reply_waitq; | ||
75 | |||
76 | /* | ||
77 | * Mutex ordering: transaction_mutex -> watch_mutex -> request_mutex. | ||
78 | * response_mutex is never taken simultaneously with the other three. | ||
79 | */ | ||
80 | |||
81 | /* One request at a time. */ | ||
82 | struct mutex request_mutex; | ||
83 | |||
84 | /* Protect xenbus reader thread against save/restore. */ | ||
85 | struct mutex response_mutex; | ||
86 | |||
87 | /* Protect transactions against save/restore. */ | ||
88 | struct rw_semaphore transaction_mutex; | ||
89 | |||
90 | /* Protect watch (de)register against save/restore. */ | ||
91 | struct rw_semaphore watch_mutex; | ||
92 | }; | ||
93 | |||
94 | static struct xs_handle xs_state; | ||
95 | |||
96 | /* List of registered watches, and a lock to protect it. */ | ||
97 | static LIST_HEAD(watches); | ||
98 | static DEFINE_SPINLOCK(watches_lock); | ||
99 | |||
100 | /* List of pending watch callback events, and a lock to protect it. */ | ||
101 | static LIST_HEAD(watch_events); | ||
102 | static DEFINE_SPINLOCK(watch_events_lock); | ||
103 | |||
104 | /* | ||
105 | * Details of the xenwatch callback kernel thread. The thread waits on the | ||
106 | * watch_events_waitq for work to do (queued on watch_events list). When it | ||
107 | * wakes up it acquires the xenwatch_mutex before reading the list and | ||
108 | * carrying out work. | ||
109 | */ | ||
110 | static pid_t xenwatch_pid; | ||
111 | static DEFINE_MUTEX(xenwatch_mutex); | ||
112 | static DECLARE_WAIT_QUEUE_HEAD(watch_events_waitq); | ||
113 | |||
114 | static int get_error(const char *errorstring) | ||
115 | { | ||
116 | unsigned int i; | ||
117 | |||
118 | for (i = 0; strcmp(errorstring, xsd_errors[i].errstring) != 0; i++) { | ||
119 | if (i == ARRAY_SIZE(xsd_errors) - 1) { | ||
120 | printk(KERN_WARNING | ||
121 | "XENBUS xen store gave: unknown error %s", | ||
122 | errorstring); | ||
123 | return EINVAL; | ||
124 | } | ||
125 | } | ||
126 | return xsd_errors[i].errnum; | ||
127 | } | ||
128 | |||
129 | static void *read_reply(enum xsd_sockmsg_type *type, unsigned int *len) | ||
130 | { | ||
131 | struct xs_stored_msg *msg; | ||
132 | char *body; | ||
133 | |||
134 | spin_lock(&xs_state.reply_lock); | ||
135 | |||
136 | while (list_empty(&xs_state.reply_list)) { | ||
137 | spin_unlock(&xs_state.reply_lock); | ||
138 | /* XXX FIXME: Avoid synchronous wait for response here. */ | ||
139 | wait_event(xs_state.reply_waitq, | ||
140 | !list_empty(&xs_state.reply_list)); | ||
141 | spin_lock(&xs_state.reply_lock); | ||
142 | } | ||
143 | |||
144 | msg = list_entry(xs_state.reply_list.next, | ||
145 | struct xs_stored_msg, list); | ||
146 | list_del(&msg->list); | ||
147 | |||
148 | spin_unlock(&xs_state.reply_lock); | ||
149 | |||
150 | *type = msg->hdr.type; | ||
151 | if (len) | ||
152 | *len = msg->hdr.len; | ||
153 | body = msg->u.reply.body; | ||
154 | |||
155 | kfree(msg); | ||
156 | |||
157 | return body; | ||
158 | } | ||
159 | |||
160 | void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg) | ||
161 | { | ||
162 | void *ret; | ||
163 | struct xsd_sockmsg req_msg = *msg; | ||
164 | int err; | ||
165 | |||
166 | if (req_msg.type == XS_TRANSACTION_START) | ||
167 | down_read(&xs_state.transaction_mutex); | ||
168 | |||
169 | mutex_lock(&xs_state.request_mutex); | ||
170 | |||
171 | err = xb_write(msg, sizeof(*msg) + msg->len); | ||
172 | if (err) { | ||
173 | msg->type = XS_ERROR; | ||
174 | ret = ERR_PTR(err); | ||
175 | } else | ||
176 | ret = read_reply(&msg->type, &msg->len); | ||
177 | |||
178 | mutex_unlock(&xs_state.request_mutex); | ||
179 | |||
180 | if ((msg->type == XS_TRANSACTION_END) || | ||
181 | ((req_msg.type == XS_TRANSACTION_START) && | ||
182 | (msg->type == XS_ERROR))) | ||
183 | up_read(&xs_state.transaction_mutex); | ||
184 | |||
185 | return ret; | ||
186 | } | ||
187 | |||
188 | /* Send message to xs, get kmalloc'ed reply. ERR_PTR() on error. */ | ||
189 | static void *xs_talkv(struct xenbus_transaction t, | ||
190 | enum xsd_sockmsg_type type, | ||
191 | const struct kvec *iovec, | ||
192 | unsigned int num_vecs, | ||
193 | unsigned int *len) | ||
194 | { | ||
195 | struct xsd_sockmsg msg; | ||
196 | void *ret = NULL; | ||
197 | unsigned int i; | ||
198 | int err; | ||
199 | |||
200 | msg.tx_id = t.id; | ||
201 | msg.req_id = 0; | ||
202 | msg.type = type; | ||
203 | msg.len = 0; | ||
204 | for (i = 0; i < num_vecs; i++) | ||
205 | msg.len += iovec[i].iov_len; | ||
206 | |||
207 | mutex_lock(&xs_state.request_mutex); | ||
208 | |||
209 | err = xb_write(&msg, sizeof(msg)); | ||
210 | if (err) { | ||
211 | mutex_unlock(&xs_state.request_mutex); | ||
212 | return ERR_PTR(err); | ||
213 | } | ||
214 | |||
215 | for (i = 0; i < num_vecs; i++) { | ||
216 | err = xb_write(iovec[i].iov_base, iovec[i].iov_len); | ||
217 | if (err) { | ||
218 | mutex_unlock(&xs_state.request_mutex); | ||
219 | return ERR_PTR(err); | ||
220 | } | ||
221 | } | ||
222 | |||
223 | ret = read_reply(&msg.type, len); | ||
224 | |||
225 | mutex_unlock(&xs_state.request_mutex); | ||
226 | |||
227 | if (IS_ERR(ret)) | ||
228 | return ret; | ||
229 | |||
230 | if (msg.type == XS_ERROR) { | ||
231 | err = get_error(ret); | ||
232 | kfree(ret); | ||
233 | return ERR_PTR(-err); | ||
234 | } | ||
235 | |||
236 | if (msg.type != type) { | ||
237 | if (printk_ratelimit()) | ||
238 | printk(KERN_WARNING | ||
239 | "XENBUS unexpected type [%d], expected [%d]\n", | ||
240 | msg.type, type); | ||
241 | kfree(ret); | ||
242 | return ERR_PTR(-EINVAL); | ||
243 | } | ||
244 | return ret; | ||
245 | } | ||
246 | |||
247 | /* Simplified version of xs_talkv: single message. */ | ||
248 | static void *xs_single(struct xenbus_transaction t, | ||
249 | enum xsd_sockmsg_type type, | ||
250 | const char *string, | ||
251 | unsigned int *len) | ||
252 | { | ||
253 | struct kvec iovec; | ||
254 | |||
255 | iovec.iov_base = (void *)string; | ||
256 | iovec.iov_len = strlen(string) + 1; | ||
257 | return xs_talkv(t, type, &iovec, 1, len); | ||
258 | } | ||
259 | |||
260 | /* Many commands only need an ack, don't care what it says. */ | ||
261 | static int xs_error(char *reply) | ||
262 | { | ||
263 | if (IS_ERR(reply)) | ||
264 | return PTR_ERR(reply); | ||
265 | kfree(reply); | ||
266 | return 0; | ||
267 | } | ||
268 | |||
269 | static unsigned int count_strings(const char *strings, unsigned int len) | ||
270 | { | ||
271 | unsigned int num; | ||
272 | const char *p; | ||
273 | |||
274 | for (p = strings, num = 0; p < strings + len; p += strlen(p) + 1) | ||
275 | num++; | ||
276 | |||
277 | return num; | ||
278 | } | ||
279 | |||
280 | /* Return the path to dir with /name appended. Buffer must be kfree()'ed. */ | ||
281 | static char *join(const char *dir, const char *name) | ||
282 | { | ||
283 | char *buffer; | ||
284 | |||
285 | if (strlen(name) == 0) | ||
286 | buffer = kasprintf(GFP_KERNEL, "%s", dir); | ||
287 | else | ||
288 | buffer = kasprintf(GFP_KERNEL, "%s/%s", dir, name); | ||
289 | return (!buffer) ? ERR_PTR(-ENOMEM) : buffer; | ||
290 | } | ||
291 | |||
292 | static char **split(char *strings, unsigned int len, unsigned int *num) | ||
293 | { | ||
294 | char *p, **ret; | ||
295 | |||
296 | /* Count the strings. */ | ||
297 | *num = count_strings(strings, len); | ||
298 | |||
299 | /* Transfer to one big alloc for easy freeing. */ | ||
300 | ret = kmalloc(*num * sizeof(char *) + len, GFP_KERNEL); | ||
301 | if (!ret) { | ||
302 | kfree(strings); | ||
303 | return ERR_PTR(-ENOMEM); | ||
304 | } | ||
305 | memcpy(&ret[*num], strings, len); | ||
306 | kfree(strings); | ||
307 | |||
308 | strings = (char *)&ret[*num]; | ||
309 | for (p = strings, *num = 0; p < strings + len; p += strlen(p) + 1) | ||
310 | ret[(*num)++] = p; | ||
311 | |||
312 | return ret; | ||
313 | } | ||
314 | |||
315 | char **xenbus_directory(struct xenbus_transaction t, | ||
316 | const char *dir, const char *node, unsigned int *num) | ||
317 | { | ||
318 | char *strings, *path; | ||
319 | unsigned int len; | ||
320 | |||
321 | path = join(dir, node); | ||
322 | if (IS_ERR(path)) | ||
323 | return (char **)path; | ||
324 | |||
325 | strings = xs_single(t, XS_DIRECTORY, path, &len); | ||
326 | kfree(path); | ||
327 | if (IS_ERR(strings)) | ||
328 | return (char **)strings; | ||
329 | |||
330 | return split(strings, len, num); | ||
331 | } | ||
332 | EXPORT_SYMBOL_GPL(xenbus_directory); | ||
333 | |||
334 | /* Check if a path exists. Return 1 if it does. */ | ||
335 | int xenbus_exists(struct xenbus_transaction t, | ||
336 | const char *dir, const char *node) | ||
337 | { | ||
338 | char **d; | ||
339 | int dir_n; | ||
340 | |||
341 | d = xenbus_directory(t, dir, node, &dir_n); | ||
342 | if (IS_ERR(d)) | ||
343 | return 0; | ||
344 | kfree(d); | ||
345 | return 1; | ||
346 | } | ||
347 | EXPORT_SYMBOL_GPL(xenbus_exists); | ||
348 | |||
349 | /* Get the value of a single file. | ||
350 | * Returns a kmalloced value: call free() on it after use. | ||
351 | * len indicates length in bytes. | ||
352 | */ | ||
353 | void *xenbus_read(struct xenbus_transaction t, | ||
354 | const char *dir, const char *node, unsigned int *len) | ||
355 | { | ||
356 | char *path; | ||
357 | void *ret; | ||
358 | |||
359 | path = join(dir, node); | ||
360 | if (IS_ERR(path)) | ||
361 | return (void *)path; | ||
362 | |||
363 | ret = xs_single(t, XS_READ, path, len); | ||
364 | kfree(path); | ||
365 | return ret; | ||
366 | } | ||
367 | EXPORT_SYMBOL_GPL(xenbus_read); | ||
368 | |||
369 | /* Write the value of a single file. | ||
370 | * Returns -err on failure. | ||
371 | */ | ||
372 | int xenbus_write(struct xenbus_transaction t, | ||
373 | const char *dir, const char *node, const char *string) | ||
374 | { | ||
375 | const char *path; | ||
376 | struct kvec iovec[2]; | ||
377 | int ret; | ||
378 | |||
379 | path = join(dir, node); | ||
380 | if (IS_ERR(path)) | ||
381 | return PTR_ERR(path); | ||
382 | |||
383 | iovec[0].iov_base = (void *)path; | ||
384 | iovec[0].iov_len = strlen(path) + 1; | ||
385 | iovec[1].iov_base = (void *)string; | ||
386 | iovec[1].iov_len = strlen(string); | ||
387 | |||
388 | ret = xs_error(xs_talkv(t, XS_WRITE, iovec, ARRAY_SIZE(iovec), NULL)); | ||
389 | kfree(path); | ||
390 | return ret; | ||
391 | } | ||
392 | EXPORT_SYMBOL_GPL(xenbus_write); | ||
393 | |||
394 | /* Create a new directory. */ | ||
395 | int xenbus_mkdir(struct xenbus_transaction t, | ||
396 | const char *dir, const char *node) | ||
397 | { | ||
398 | char *path; | ||
399 | int ret; | ||
400 | |||
401 | path = join(dir, node); | ||
402 | if (IS_ERR(path)) | ||
403 | return PTR_ERR(path); | ||
404 | |||
405 | ret = xs_error(xs_single(t, XS_MKDIR, path, NULL)); | ||
406 | kfree(path); | ||
407 | return ret; | ||
408 | } | ||
409 | EXPORT_SYMBOL_GPL(xenbus_mkdir); | ||
410 | |||
411 | /* Destroy a file or directory (directories must be empty). */ | ||
412 | int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node) | ||
413 | { | ||
414 | char *path; | ||
415 | int ret; | ||
416 | |||
417 | path = join(dir, node); | ||
418 | if (IS_ERR(path)) | ||
419 | return PTR_ERR(path); | ||
420 | |||
421 | ret = xs_error(xs_single(t, XS_RM, path, NULL)); | ||
422 | kfree(path); | ||
423 | return ret; | ||
424 | } | ||
425 | EXPORT_SYMBOL_GPL(xenbus_rm); | ||
426 | |||
427 | /* Start a transaction: changes by others will not be seen during this | ||
428 | * transaction, and changes will not be visible to others until end. | ||
429 | */ | ||
430 | int xenbus_transaction_start(struct xenbus_transaction *t) | ||
431 | { | ||
432 | char *id_str; | ||
433 | |||
434 | down_read(&xs_state.transaction_mutex); | ||
435 | |||
436 | id_str = xs_single(XBT_NIL, XS_TRANSACTION_START, "", NULL); | ||
437 | if (IS_ERR(id_str)) { | ||
438 | up_read(&xs_state.transaction_mutex); | ||
439 | return PTR_ERR(id_str); | ||
440 | } | ||
441 | |||
442 | t->id = simple_strtoul(id_str, NULL, 0); | ||
443 | kfree(id_str); | ||
444 | return 0; | ||
445 | } | ||
446 | EXPORT_SYMBOL_GPL(xenbus_transaction_start); | ||
447 | |||
448 | /* End a transaction. | ||
449 | * If abandon is true, transaction is discarded instead of committed. | ||
450 | */ | ||
451 | int xenbus_transaction_end(struct xenbus_transaction t, int abort) | ||
452 | { | ||
453 | char abortstr[2]; | ||
454 | int err; | ||
455 | |||
456 | if (abort) | ||
457 | strcpy(abortstr, "F"); | ||
458 | else | ||
459 | strcpy(abortstr, "T"); | ||
460 | |||
461 | err = xs_error(xs_single(t, XS_TRANSACTION_END, abortstr, NULL)); | ||
462 | |||
463 | up_read(&xs_state.transaction_mutex); | ||
464 | |||
465 | return err; | ||
466 | } | ||
467 | EXPORT_SYMBOL_GPL(xenbus_transaction_end); | ||
468 | |||
469 | /* Single read and scanf: returns -errno or num scanned. */ | ||
470 | int xenbus_scanf(struct xenbus_transaction t, | ||
471 | const char *dir, const char *node, const char *fmt, ...) | ||
472 | { | ||
473 | va_list ap; | ||
474 | int ret; | ||
475 | char *val; | ||
476 | |||
477 | val = xenbus_read(t, dir, node, NULL); | ||
478 | if (IS_ERR(val)) | ||
479 | return PTR_ERR(val); | ||
480 | |||
481 | va_start(ap, fmt); | ||
482 | ret = vsscanf(val, fmt, ap); | ||
483 | va_end(ap); | ||
484 | kfree(val); | ||
485 | /* Distinctive errno. */ | ||
486 | if (ret == 0) | ||
487 | return -ERANGE; | ||
488 | return ret; | ||
489 | } | ||
490 | EXPORT_SYMBOL_GPL(xenbus_scanf); | ||
491 | |||
492 | /* Single printf and write: returns -errno or 0. */ | ||
493 | int xenbus_printf(struct xenbus_transaction t, | ||
494 | const char *dir, const char *node, const char *fmt, ...) | ||
495 | { | ||
496 | va_list ap; | ||
497 | int ret; | ||
498 | #define PRINTF_BUFFER_SIZE 4096 | ||
499 | char *printf_buffer; | ||
500 | |||
501 | printf_buffer = kmalloc(PRINTF_BUFFER_SIZE, GFP_KERNEL); | ||
502 | if (printf_buffer == NULL) | ||
503 | return -ENOMEM; | ||
504 | |||
505 | va_start(ap, fmt); | ||
506 | ret = vsnprintf(printf_buffer, PRINTF_BUFFER_SIZE, fmt, ap); | ||
507 | va_end(ap); | ||
508 | |||
509 | BUG_ON(ret > PRINTF_BUFFER_SIZE-1); | ||
510 | ret = xenbus_write(t, dir, node, printf_buffer); | ||
511 | |||
512 | kfree(printf_buffer); | ||
513 | |||
514 | return ret; | ||
515 | } | ||
516 | EXPORT_SYMBOL_GPL(xenbus_printf); | ||
517 | |||
518 | /* Takes tuples of names, scanf-style args, and void **, NULL terminated. */ | ||
519 | int xenbus_gather(struct xenbus_transaction t, const char *dir, ...) | ||
520 | { | ||
521 | va_list ap; | ||
522 | const char *name; | ||
523 | int ret = 0; | ||
524 | |||
525 | va_start(ap, dir); | ||
526 | while (ret == 0 && (name = va_arg(ap, char *)) != NULL) { | ||
527 | const char *fmt = va_arg(ap, char *); | ||
528 | void *result = va_arg(ap, void *); | ||
529 | char *p; | ||
530 | |||
531 | p = xenbus_read(t, dir, name, NULL); | ||
532 | if (IS_ERR(p)) { | ||
533 | ret = PTR_ERR(p); | ||
534 | break; | ||
535 | } | ||
536 | if (fmt) { | ||
537 | if (sscanf(p, fmt, result) == 0) | ||
538 | ret = -EINVAL; | ||
539 | kfree(p); | ||
540 | } else | ||
541 | *(char **)result = p; | ||
542 | } | ||
543 | va_end(ap); | ||
544 | return ret; | ||
545 | } | ||
546 | EXPORT_SYMBOL_GPL(xenbus_gather); | ||
547 | |||
548 | static int xs_watch(const char *path, const char *token) | ||
549 | { | ||
550 | struct kvec iov[2]; | ||
551 | |||
552 | iov[0].iov_base = (void *)path; | ||
553 | iov[0].iov_len = strlen(path) + 1; | ||
554 | iov[1].iov_base = (void *)token; | ||
555 | iov[1].iov_len = strlen(token) + 1; | ||
556 | |||
557 | return xs_error(xs_talkv(XBT_NIL, XS_WATCH, iov, | ||
558 | ARRAY_SIZE(iov), NULL)); | ||
559 | } | ||
560 | |||
561 | static int xs_unwatch(const char *path, const char *token) | ||
562 | { | ||
563 | struct kvec iov[2]; | ||
564 | |||
565 | iov[0].iov_base = (char *)path; | ||
566 | iov[0].iov_len = strlen(path) + 1; | ||
567 | iov[1].iov_base = (char *)token; | ||
568 | iov[1].iov_len = strlen(token) + 1; | ||
569 | |||
570 | return xs_error(xs_talkv(XBT_NIL, XS_UNWATCH, iov, | ||
571 | ARRAY_SIZE(iov), NULL)); | ||
572 | } | ||
573 | |||
574 | static struct xenbus_watch *find_watch(const char *token) | ||
575 | { | ||
576 | struct xenbus_watch *i, *cmp; | ||
577 | |||
578 | cmp = (void *)simple_strtoul(token, NULL, 16); | ||
579 | |||
580 | list_for_each_entry(i, &watches, list) | ||
581 | if (i == cmp) | ||
582 | return i; | ||
583 | |||
584 | return NULL; | ||
585 | } | ||
586 | |||
587 | /* Register callback to watch this node. */ | ||
588 | int register_xenbus_watch(struct xenbus_watch *watch) | ||
589 | { | ||
590 | /* Pointer in ascii is the token. */ | ||
591 | char token[sizeof(watch) * 2 + 1]; | ||
592 | int err; | ||
593 | |||
594 | sprintf(token, "%lX", (long)watch); | ||
595 | |||
596 | down_read(&xs_state.watch_mutex); | ||
597 | |||
598 | spin_lock(&watches_lock); | ||
599 | BUG_ON(find_watch(token)); | ||
600 | list_add(&watch->list, &watches); | ||
601 | spin_unlock(&watches_lock); | ||
602 | |||
603 | err = xs_watch(watch->node, token); | ||
604 | |||
605 | /* Ignore errors due to multiple registration. */ | ||
606 | if ((err != 0) && (err != -EEXIST)) { | ||
607 | spin_lock(&watches_lock); | ||
608 | list_del(&watch->list); | ||
609 | spin_unlock(&watches_lock); | ||
610 | } | ||
611 | |||
612 | up_read(&xs_state.watch_mutex); | ||
613 | |||
614 | return err; | ||
615 | } | ||
616 | EXPORT_SYMBOL_GPL(register_xenbus_watch); | ||
617 | |||
618 | void unregister_xenbus_watch(struct xenbus_watch *watch) | ||
619 | { | ||
620 | struct xs_stored_msg *msg, *tmp; | ||
621 | char token[sizeof(watch) * 2 + 1]; | ||
622 | int err; | ||
623 | |||
624 | sprintf(token, "%lX", (long)watch); | ||
625 | |||
626 | down_read(&xs_state.watch_mutex); | ||
627 | |||
628 | spin_lock(&watches_lock); | ||
629 | BUG_ON(!find_watch(token)); | ||
630 | list_del(&watch->list); | ||
631 | spin_unlock(&watches_lock); | ||
632 | |||
633 | err = xs_unwatch(watch->node, token); | ||
634 | if (err) | ||
635 | printk(KERN_WARNING | ||
636 | "XENBUS Failed to release watch %s: %i\n", | ||
637 | watch->node, err); | ||
638 | |||
639 | up_read(&xs_state.watch_mutex); | ||
640 | |||
641 | /* Make sure there are no callbacks running currently (unless | ||
642 | its us) */ | ||
643 | if (current->pid != xenwatch_pid) | ||
644 | mutex_lock(&xenwatch_mutex); | ||
645 | |||
646 | /* Cancel pending watch events. */ | ||
647 | spin_lock(&watch_events_lock); | ||
648 | list_for_each_entry_safe(msg, tmp, &watch_events, list) { | ||
649 | if (msg->u.watch.handle != watch) | ||
650 | continue; | ||
651 | list_del(&msg->list); | ||
652 | kfree(msg->u.watch.vec); | ||
653 | kfree(msg); | ||
654 | } | ||
655 | spin_unlock(&watch_events_lock); | ||
656 | |||
657 | if (current->pid != xenwatch_pid) | ||
658 | mutex_unlock(&xenwatch_mutex); | ||
659 | } | ||
660 | EXPORT_SYMBOL_GPL(unregister_xenbus_watch); | ||
661 | |||
662 | void xs_suspend(void) | ||
663 | { | ||
664 | down_write(&xs_state.transaction_mutex); | ||
665 | down_write(&xs_state.watch_mutex); | ||
666 | mutex_lock(&xs_state.request_mutex); | ||
667 | mutex_lock(&xs_state.response_mutex); | ||
668 | } | ||
669 | |||
670 | void xs_resume(void) | ||
671 | { | ||
672 | struct xenbus_watch *watch; | ||
673 | char token[sizeof(watch) * 2 + 1]; | ||
674 | |||
675 | mutex_unlock(&xs_state.response_mutex); | ||
676 | mutex_unlock(&xs_state.request_mutex); | ||
677 | up_write(&xs_state.transaction_mutex); | ||
678 | |||
679 | /* No need for watches_lock: the watch_mutex is sufficient. */ | ||
680 | list_for_each_entry(watch, &watches, list) { | ||
681 | sprintf(token, "%lX", (long)watch); | ||
682 | xs_watch(watch->node, token); | ||
683 | } | ||
684 | |||
685 | up_write(&xs_state.watch_mutex); | ||
686 | } | ||
687 | |||
688 | void xs_suspend_cancel(void) | ||
689 | { | ||
690 | mutex_unlock(&xs_state.response_mutex); | ||
691 | mutex_unlock(&xs_state.request_mutex); | ||
692 | up_write(&xs_state.watch_mutex); | ||
693 | up_write(&xs_state.transaction_mutex); | ||
694 | } | ||
695 | |||
696 | static int xenwatch_thread(void *unused) | ||
697 | { | ||
698 | struct list_head *ent; | ||
699 | struct xs_stored_msg *msg; | ||
700 | |||
701 | for (;;) { | ||
702 | wait_event_interruptible(watch_events_waitq, | ||
703 | !list_empty(&watch_events)); | ||
704 | |||
705 | if (kthread_should_stop()) | ||
706 | break; | ||
707 | |||
708 | mutex_lock(&xenwatch_mutex); | ||
709 | |||
710 | spin_lock(&watch_events_lock); | ||
711 | ent = watch_events.next; | ||
712 | if (ent != &watch_events) | ||
713 | list_del(ent); | ||
714 | spin_unlock(&watch_events_lock); | ||
715 | |||
716 | if (ent != &watch_events) { | ||
717 | msg = list_entry(ent, struct xs_stored_msg, list); | ||
718 | msg->u.watch.handle->callback( | ||
719 | msg->u.watch.handle, | ||
720 | (const char **)msg->u.watch.vec, | ||
721 | msg->u.watch.vec_size); | ||
722 | kfree(msg->u.watch.vec); | ||
723 | kfree(msg); | ||
724 | } | ||
725 | |||
726 | mutex_unlock(&xenwatch_mutex); | ||
727 | } | ||
728 | |||
729 | return 0; | ||
730 | } | ||
731 | |||
732 | static int process_msg(void) | ||
733 | { | ||
734 | struct xs_stored_msg *msg; | ||
735 | char *body; | ||
736 | int err; | ||
737 | |||
738 | /* | ||
739 | * We must disallow save/restore while reading a xenstore message. | ||
740 | * A partial read across s/r leaves us out of sync with xenstored. | ||
741 | */ | ||
742 | for (;;) { | ||
743 | err = xb_wait_for_data_to_read(); | ||
744 | if (err) | ||
745 | return err; | ||
746 | mutex_lock(&xs_state.response_mutex); | ||
747 | if (xb_data_to_read()) | ||
748 | break; | ||
749 | /* We raced with save/restore: pending data 'disappeared'. */ | ||
750 | mutex_unlock(&xs_state.response_mutex); | ||
751 | } | ||
752 | |||
753 | |||
754 | msg = kmalloc(sizeof(*msg), GFP_KERNEL); | ||
755 | if (msg == NULL) { | ||
756 | err = -ENOMEM; | ||
757 | goto out; | ||
758 | } | ||
759 | |||
760 | err = xb_read(&msg->hdr, sizeof(msg->hdr)); | ||
761 | if (err) { | ||
762 | kfree(msg); | ||
763 | goto out; | ||
764 | } | ||
765 | |||
766 | body = kmalloc(msg->hdr.len + 1, GFP_KERNEL); | ||
767 | if (body == NULL) { | ||
768 | kfree(msg); | ||
769 | err = -ENOMEM; | ||
770 | goto out; | ||
771 | } | ||
772 | |||
773 | err = xb_read(body, msg->hdr.len); | ||
774 | if (err) { | ||
775 | kfree(body); | ||
776 | kfree(msg); | ||
777 | goto out; | ||
778 | } | ||
779 | body[msg->hdr.len] = '\0'; | ||
780 | |||
781 | if (msg->hdr.type == XS_WATCH_EVENT) { | ||
782 | msg->u.watch.vec = split(body, msg->hdr.len, | ||
783 | &msg->u.watch.vec_size); | ||
784 | if (IS_ERR(msg->u.watch.vec)) { | ||
785 | kfree(msg); | ||
786 | err = PTR_ERR(msg->u.watch.vec); | ||
787 | goto out; | ||
788 | } | ||
789 | |||
790 | spin_lock(&watches_lock); | ||
791 | msg->u.watch.handle = find_watch( | ||
792 | msg->u.watch.vec[XS_WATCH_TOKEN]); | ||
793 | if (msg->u.watch.handle != NULL) { | ||
794 | spin_lock(&watch_events_lock); | ||
795 | list_add_tail(&msg->list, &watch_events); | ||
796 | wake_up(&watch_events_waitq); | ||
797 | spin_unlock(&watch_events_lock); | ||
798 | } else { | ||
799 | kfree(msg->u.watch.vec); | ||
800 | kfree(msg); | ||
801 | } | ||
802 | spin_unlock(&watches_lock); | ||
803 | } else { | ||
804 | msg->u.reply.body = body; | ||
805 | spin_lock(&xs_state.reply_lock); | ||
806 | list_add_tail(&msg->list, &xs_state.reply_list); | ||
807 | spin_unlock(&xs_state.reply_lock); | ||
808 | wake_up(&xs_state.reply_waitq); | ||
809 | } | ||
810 | |||
811 | out: | ||
812 | mutex_unlock(&xs_state.response_mutex); | ||
813 | return err; | ||
814 | } | ||
815 | |||
816 | static int xenbus_thread(void *unused) | ||
817 | { | ||
818 | int err; | ||
819 | |||
820 | for (;;) { | ||
821 | err = process_msg(); | ||
822 | if (err) | ||
823 | printk(KERN_WARNING "XENBUS error %d while reading " | ||
824 | "message\n", err); | ||
825 | if (kthread_should_stop()) | ||
826 | break; | ||
827 | } | ||
828 | |||
829 | return 0; | ||
830 | } | ||
831 | |||
832 | int xs_init(void) | ||
833 | { | ||
834 | int err; | ||
835 | struct task_struct *task; | ||
836 | |||
837 | INIT_LIST_HEAD(&xs_state.reply_list); | ||
838 | spin_lock_init(&xs_state.reply_lock); | ||
839 | init_waitqueue_head(&xs_state.reply_waitq); | ||
840 | |||
841 | mutex_init(&xs_state.request_mutex); | ||
842 | mutex_init(&xs_state.response_mutex); | ||
843 | init_rwsem(&xs_state.transaction_mutex); | ||
844 | init_rwsem(&xs_state.watch_mutex); | ||
845 | |||
846 | /* Initialize the shared memory rings to talk to xenstored */ | ||
847 | err = xb_init_comms(); | ||
848 | if (err) | ||
849 | return err; | ||
850 | |||
851 | task = kthread_run(xenwatch_thread, NULL, "xenwatch"); | ||
852 | if (IS_ERR(task)) | ||
853 | return PTR_ERR(task); | ||
854 | xenwatch_pid = task->pid; | ||
855 | |||
856 | task = kthread_run(xenbus_thread, NULL, "xenbus"); | ||
857 | if (IS_ERR(task)) | ||
858 | return PTR_ERR(task); | ||
859 | |||
860 | return 0; | ||
861 | } | ||