1 /******************************************************************************
2 * xenbus.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 _XEN_XENBUS_H
35 #define _XEN_XENBUS_H
36
37 #include <linux/device.h>
38 #include <linux/notifier.h>
39 #include <linux/mutex.h>
40 #include <linux/completion.h>
41 #include <linux/init.h>
42 #include <linux/slab.h>
43 #include <xen/interface/xen.h>
44 #include <xen/interface/grant_table.h>
45 #include <xen/interface/io/xenbus.h>
46 #include <xen/interface/io/xs_wire.h>
47
48 /* Register callback to watch this node. */
49 struct xenbus_watch
50 {
51 struct list_head list;
52
53 /* Path being watched. */
54 const char *node;
55
56 /* Callback (executed in a process context with no locks held). */
57 void (*callback)(struct xenbus_watch *,
58 const char **vec, unsigned int len);
59 };
60
61
62 /* A xenbus device. */
63 struct xenbus_device {
64 const char *devicetype;
65 const char *nodename;
66 const char *otherend;
67 int otherend_id;
68 struct xenbus_watch otherend_watch;
69 struct device dev;
70 enum xenbus_state state;
71 struct completion down;
72 };
73
to_xenbus_device(struct device * dev)74 static inline struct xenbus_device *to_xenbus_device(struct device *dev)
75 {
76 return container_of(dev, struct xenbus_device, dev);
77 }
78
79 struct xenbus_device_id
80 {
81 /* .../device/<device_type>/<identifier> */
82 char devicetype[32]; /* General class of device. */
83 };
84
85 /* A xenbus driver. */
86 struct xenbus_driver {
87 char *name;
88 struct module *owner;
89 const struct xenbus_device_id *ids;
90 int (*probe)(struct xenbus_device *dev,
91 const struct xenbus_device_id *id);
92 void (*otherend_changed)(struct xenbus_device *dev,
93 enum xenbus_state backend_state);
94 int (*remove)(struct xenbus_device *dev);
95 int (*suspend)(struct xenbus_device *dev);
96 int (*resume)(struct xenbus_device *dev);
97 int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *);
98 struct device_driver driver;
99 int (*read_otherend_details)(struct xenbus_device *dev);
100 int (*is_ready)(struct xenbus_device *dev);
101 };
102
to_xenbus_driver(struct device_driver * drv)103 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
104 {
105 return container_of(drv, struct xenbus_driver, driver);
106 }
107
108 int __must_check __xenbus_register_frontend(struct xenbus_driver *drv,
109 struct module *owner,
110 const char *mod_name);
111
112 static inline int __must_check
xenbus_register_frontend(struct xenbus_driver * drv)113 xenbus_register_frontend(struct xenbus_driver *drv)
114 {
115 WARN_ON(drv->owner != THIS_MODULE);
116 return __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME);
117 }
118
119 int __must_check __xenbus_register_backend(struct xenbus_driver *drv,
120 struct module *owner,
121 const char *mod_name);
122 static inline int __must_check
xenbus_register_backend(struct xenbus_driver * drv)123 xenbus_register_backend(struct xenbus_driver *drv)
124 {
125 WARN_ON(drv->owner != THIS_MODULE);
126 return __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME);
127 }
128
129 void xenbus_unregister_driver(struct xenbus_driver *drv);
130
131 struct xenbus_transaction
132 {
133 u32 id;
134 };
135
136 /* Nil transaction ID. */
137 #define XBT_NIL ((struct xenbus_transaction) { 0 })
138
139 char **xenbus_directory(struct xenbus_transaction t,
140 const char *dir, const char *node, unsigned int *num);
141 void *xenbus_read(struct xenbus_transaction t,
142 const char *dir, const char *node, unsigned int *len);
143 int xenbus_write(struct xenbus_transaction t,
144 const char *dir, const char *node, const char *string);
145 int xenbus_mkdir(struct xenbus_transaction t,
146 const char *dir, const char *node);
147 int xenbus_exists(struct xenbus_transaction t,
148 const char *dir, const char *node);
149 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
150 int xenbus_transaction_start(struct xenbus_transaction *t);
151 int xenbus_transaction_end(struct xenbus_transaction t, int abort);
152
153 /* Single read and scanf: returns -errno or num scanned if > 0. */
154 int xenbus_scanf(struct xenbus_transaction t,
155 const char *dir, const char *node, const char *fmt, ...)
156 __attribute__((format(scanf, 4, 5)));
157
158 /* Single printf and write: returns -errno or 0. */
159 int xenbus_printf(struct xenbus_transaction t,
160 const char *dir, const char *node, const char *fmt, ...)
161 __attribute__((format(printf, 4, 5)));
162
163 /* Generic read function: NULL-terminated triples of name,
164 * sprintf-style type string, and pointer. Returns 0 or errno.*/
165 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
166
167 /* notifer routines for when the xenstore comes up */
168 extern int xenstored_ready;
169 int register_xenstore_notifier(struct notifier_block *nb);
170 void unregister_xenstore_notifier(struct notifier_block *nb);
171
172 int register_xenbus_watch(struct xenbus_watch *watch);
173 void unregister_xenbus_watch(struct xenbus_watch *watch);
174 void xs_suspend(void);
175 void xs_resume(void);
176 void xs_suspend_cancel(void);
177
178 /* Used by xenbus_dev to borrow kernel's store connection. */
179 void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg);
180
181 struct work_struct;
182
183 /* Prepare for domain suspend: then resume or cancel the suspend. */
184 void xenbus_suspend(void);
185 void xenbus_resume(void);
186 void xenbus_probe(struct work_struct *);
187 void xenbus_suspend_cancel(void);
188
189 #define XENBUS_IS_ERR_READ(str) ({ \
190 if (!IS_ERR(str) && strlen(str) == 0) { \
191 kfree(str); \
192 str = ERR_PTR(-ERANGE); \
193 } \
194 IS_ERR(str); \
195 })
196
197 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
198
199 int xenbus_watch_path(struct xenbus_device *dev, const char *path,
200 struct xenbus_watch *watch,
201 void (*callback)(struct xenbus_watch *,
202 const char **, unsigned int));
203 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
204 void (*callback)(struct xenbus_watch *,
205 const char **, unsigned int),
206 const char *pathfmt, ...)
207 __attribute__ ((format (printf, 4, 5)));
208
209 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
210 int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn);
211 int xenbus_map_ring_valloc(struct xenbus_device *dev,
212 int gnt_ref, void **vaddr);
213 int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
214 grant_handle_t *handle, void *vaddr);
215
216 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
217 int xenbus_unmap_ring(struct xenbus_device *dev,
218 grant_handle_t handle, void *vaddr);
219
220 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
221 int xenbus_bind_evtchn(struct xenbus_device *dev, int remote_port, int *port);
222 int xenbus_free_evtchn(struct xenbus_device *dev, int port);
223
224 enum xenbus_state xenbus_read_driver_state(const char *path);
225
226 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);
227 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...);
228
229 const char *xenbus_strstate(enum xenbus_state state);
230 int xenbus_dev_is_online(struct xenbus_device *dev);
231 int xenbus_frontend_closed(struct xenbus_device *dev);
232
233 #endif /* _XEN_XENBUS_H */
234