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/export.h>
41 #include <linux/completion.h>
42 #include <linux/init.h>
43 #include <linux/slab.h>
44 #include <xen/interface/xen.h>
45 #include <xen/interface/grant_table.h>
46 #include <xen/interface/io/xenbus.h>
47 #include <xen/interface/io/xs_wire.h>
48
49 #define XENBUS_MAX_RING_GRANT_ORDER 4
50 #define XENBUS_MAX_RING_GRANTS (1U << XENBUS_MAX_RING_GRANT_ORDER)
51 #define INVALID_GRANT_HANDLE (~0U)
52
53 /* Register callback to watch this node. */
54 struct xenbus_watch
55 {
56 struct list_head list;
57
58 /* Path being watched. */
59 const char *node;
60
61 unsigned int nr_pending;
62
63 /*
64 * Called just before enqueing new event while a spinlock is held.
65 * The event will be discarded if this callback returns false.
66 */
67 bool (*will_handle)(struct xenbus_watch *,
68 const char **vec, unsigned int len);
69
70 /* Callback (executed in a process context with no locks held). */
71 void (*callback)(struct xenbus_watch *,
72 const char **vec, unsigned int len);
73 };
74
75
76 /* A xenbus device. */
77 struct xenbus_device {
78 const char *devicetype;
79 const char *nodename;
80 const char *otherend;
81 int otherend_id;
82 struct xenbus_watch otherend_watch;
83 struct device dev;
84 enum xenbus_state state;
85 struct completion down;
86 struct work_struct work;
87 };
88
to_xenbus_device(struct device * dev)89 static inline struct xenbus_device *to_xenbus_device(struct device *dev)
90 {
91 return container_of(dev, struct xenbus_device, dev);
92 }
93
94 struct xenbus_device_id
95 {
96 /* .../device/<device_type>/<identifier> */
97 char devicetype[32]; /* General class of device. */
98 };
99
100 /* A xenbus driver. */
101 struct xenbus_driver {
102 const char *name; /* defaults to ids[0].devicetype */
103 const struct xenbus_device_id *ids;
104 int (*probe)(struct xenbus_device *dev,
105 const struct xenbus_device_id *id);
106 void (*otherend_changed)(struct xenbus_device *dev,
107 enum xenbus_state backend_state);
108 int (*remove)(struct xenbus_device *dev);
109 int (*suspend)(struct xenbus_device *dev);
110 int (*resume)(struct xenbus_device *dev);
111 int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *);
112 struct device_driver driver;
113 int (*read_otherend_details)(struct xenbus_device *dev);
114 int (*is_ready)(struct xenbus_device *dev);
115 };
116
to_xenbus_driver(struct device_driver * drv)117 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
118 {
119 return container_of(drv, struct xenbus_driver, driver);
120 }
121
122 int __must_check __xenbus_register_frontend(struct xenbus_driver *drv,
123 struct module *owner,
124 const char *mod_name);
125 int __must_check __xenbus_register_backend(struct xenbus_driver *drv,
126 struct module *owner,
127 const char *mod_name);
128
129 #define xenbus_register_frontend(drv) \
130 __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME)
131 #define xenbus_register_backend(drv) \
132 __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME)
133
134 void xenbus_unregister_driver(struct xenbus_driver *drv);
135
136 struct xenbus_transaction
137 {
138 u32 id;
139 };
140
141 /* Nil transaction ID. */
142 #define XBT_NIL ((struct xenbus_transaction) { 0 })
143
144 char **xenbus_directory(struct xenbus_transaction t,
145 const char *dir, const char *node, unsigned int *num);
146 void *xenbus_read(struct xenbus_transaction t,
147 const char *dir, const char *node, unsigned int *len);
148 int xenbus_write(struct xenbus_transaction t,
149 const char *dir, const char *node, const char *string);
150 int xenbus_mkdir(struct xenbus_transaction t,
151 const char *dir, const char *node);
152 int xenbus_exists(struct xenbus_transaction t,
153 const char *dir, const char *node);
154 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
155 int xenbus_transaction_start(struct xenbus_transaction *t);
156 int xenbus_transaction_end(struct xenbus_transaction t, int abort);
157
158 /* Single read and scanf: returns -errno or num scanned if > 0. */
159 __scanf(4, 5)
160 int xenbus_scanf(struct xenbus_transaction t,
161 const char *dir, const char *node, const char *fmt, ...);
162
163 /* Single printf and write: returns -errno or 0. */
164 __printf(4, 5)
165 int xenbus_printf(struct xenbus_transaction t,
166 const char *dir, const char *node, const char *fmt, ...);
167
168 /* Generic read function: NULL-terminated triples of name,
169 * sprintf-style type string, and pointer. Returns 0 or errno.*/
170 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
171
172 /* notifer routines for when the xenstore comes up */
173 extern int xenstored_ready;
174 int register_xenstore_notifier(struct notifier_block *nb);
175 void unregister_xenstore_notifier(struct notifier_block *nb);
176
177 int register_xenbus_watch(struct xenbus_watch *watch);
178 void unregister_xenbus_watch(struct xenbus_watch *watch);
179 void xs_suspend(void);
180 void xs_resume(void);
181 void xs_suspend_cancel(void);
182
183 /* Used by xenbus_dev to borrow kernel's store connection. */
184 void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg);
185
186 struct work_struct;
187
188 /* Prepare for domain suspend: then resume or cancel the suspend. */
189 void xenbus_suspend(void);
190 void xenbus_resume(void);
191 void xenbus_probe(struct work_struct *);
192 void xenbus_suspend_cancel(void);
193
194 #define XENBUS_IS_ERR_READ(str) ({ \
195 if (!IS_ERR(str) && strlen(str) == 0) { \
196 kfree(str); \
197 str = ERR_PTR(-ERANGE); \
198 } \
199 IS_ERR(str); \
200 })
201
202 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
203
204 int xenbus_watch_path(struct xenbus_device *dev, const char *path,
205 struct xenbus_watch *watch,
206 bool (*will_handle)(struct xenbus_watch *,
207 const char **, unsigned int),
208 void (*callback)(struct xenbus_watch *,
209 const char **, unsigned int));
210 __printf(5, 6)
211 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
212 bool (*will_handle)(struct xenbus_watch *,
213 const char **, unsigned int),
214 void (*callback)(struct xenbus_watch *,
215 const char **, unsigned int),
216 const char *pathfmt, ...);
217
218 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
219 int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
220 unsigned int nr_pages, grant_ref_t *grefs);
221 int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
222 unsigned int nr_grefs, void **vaddr);
223 int xenbus_map_ring(struct xenbus_device *dev,
224 grant_ref_t *gnt_refs, unsigned int nr_grefs,
225 grant_handle_t *handles, unsigned long *vaddrs,
226 bool *leaked);
227
228 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
229 int xenbus_unmap_ring(struct xenbus_device *dev,
230 grant_handle_t *handles, unsigned int nr_handles,
231 unsigned long *vaddrs);
232
233 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
234 int xenbus_free_evtchn(struct xenbus_device *dev, int port);
235
236 enum xenbus_state xenbus_read_driver_state(const char *path);
237
238 __printf(3, 4)
239 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);
240 __printf(3, 4)
241 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...);
242
243 const char *xenbus_strstate(enum xenbus_state state);
244 int xenbus_dev_is_online(struct xenbus_device *dev);
245 int xenbus_frontend_closed(struct xenbus_device *dev);
246
247 #endif /* _XEN_XENBUS_H */
248