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/fs.h>
42 #include <linux/completion.h>
43 #include <linux/init.h>
44 #include <linux/slab.h>
45 #include <xen/interface/xen.h>
46 #include <xen/interface/grant_table.h>
47 #include <xen/interface/io/xenbus.h>
48 #include <xen/interface/io/xs_wire.h>
49
50 #define XENBUS_MAX_RING_GRANT_ORDER 4
51 #define XENBUS_MAX_RING_GRANTS (1U << XENBUS_MAX_RING_GRANT_ORDER)
52 #define INVALID_GRANT_HANDLE (~0U)
53
54 /* Register callback to watch this node. */
55 struct xenbus_watch
56 {
57 struct list_head list;
58
59 /* Path being watched. */
60 const char *node;
61
62 /* Callback (executed in a process context with no locks held). */
63 void (*callback)(struct xenbus_watch *,
64 const char *path, const char *token);
65 };
66
67
68 /* A xenbus device. */
69 struct xenbus_device {
70 const char *devicetype;
71 const char *nodename;
72 const char *otherend;
73 int otherend_id;
74 struct xenbus_watch otherend_watch;
75 struct device dev;
76 enum xenbus_state state;
77 struct completion down;
78 struct work_struct work;
79 };
80
to_xenbus_device(struct device * dev)81 static inline struct xenbus_device *to_xenbus_device(struct device *dev)
82 {
83 return container_of(dev, struct xenbus_device, dev);
84 }
85
86 struct xenbus_device_id
87 {
88 /* .../device/<device_type>/<identifier> */
89 char devicetype[32]; /* General class of device. */
90 };
91
92 /* A xenbus driver. */
93 struct xenbus_driver {
94 const char *name; /* defaults to ids[0].devicetype */
95 const struct xenbus_device_id *ids;
96 int (*probe)(struct xenbus_device *dev,
97 const struct xenbus_device_id *id);
98 void (*otherend_changed)(struct xenbus_device *dev,
99 enum xenbus_state backend_state);
100 int (*remove)(struct xenbus_device *dev);
101 int (*suspend)(struct xenbus_device *dev);
102 int (*resume)(struct xenbus_device *dev);
103 int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *);
104 struct device_driver driver;
105 int (*read_otherend_details)(struct xenbus_device *dev);
106 int (*is_ready)(struct xenbus_device *dev);
107 };
108
to_xenbus_driver(struct device_driver * drv)109 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
110 {
111 return container_of(drv, struct xenbus_driver, driver);
112 }
113
114 int __must_check __xenbus_register_frontend(struct xenbus_driver *drv,
115 struct module *owner,
116 const char *mod_name);
117 int __must_check __xenbus_register_backend(struct xenbus_driver *drv,
118 struct module *owner,
119 const char *mod_name);
120
121 #define xenbus_register_frontend(drv) \
122 __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME)
123 #define xenbus_register_backend(drv) \
124 __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME)
125
126 void xenbus_unregister_driver(struct xenbus_driver *drv);
127
128 struct xenbus_transaction
129 {
130 u32 id;
131 };
132
133 /* Nil transaction ID. */
134 #define XBT_NIL ((struct xenbus_transaction) { 0 })
135
136 char **xenbus_directory(struct xenbus_transaction t,
137 const char *dir, const char *node, unsigned int *num);
138 void *xenbus_read(struct xenbus_transaction t,
139 const char *dir, const char *node, unsigned int *len);
140 int xenbus_write(struct xenbus_transaction t,
141 const char *dir, const char *node, const char *string);
142 int xenbus_mkdir(struct xenbus_transaction t,
143 const char *dir, const char *node);
144 int xenbus_exists(struct xenbus_transaction t,
145 const char *dir, const char *node);
146 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
147 int xenbus_transaction_start(struct xenbus_transaction *t);
148 int xenbus_transaction_end(struct xenbus_transaction t, int abort);
149
150 /* Single read and scanf: returns -errno or num scanned if > 0. */
151 __scanf(4, 5)
152 int xenbus_scanf(struct xenbus_transaction t,
153 const char *dir, const char *node, const char *fmt, ...);
154
155 /* Read an (optional) unsigned value. */
156 unsigned int xenbus_read_unsigned(const char *dir, const char *node,
157 unsigned int default_val);
158
159 /* Single printf and write: returns -errno or 0. */
160 __printf(4, 5)
161 int xenbus_printf(struct xenbus_transaction t,
162 const char *dir, const char *node, const char *fmt, ...);
163
164 /* Generic read function: NULL-terminated triples of name,
165 * sprintf-style type string, and pointer. Returns 0 or errno.*/
166 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
167
168 /* notifer routines for when the xenstore comes up */
169 extern int xenstored_ready;
170 int register_xenstore_notifier(struct notifier_block *nb);
171 void unregister_xenstore_notifier(struct notifier_block *nb);
172
173 int register_xenbus_watch(struct xenbus_watch *watch);
174 void unregister_xenbus_watch(struct xenbus_watch *watch);
175 void xs_suspend(void);
176 void xs_resume(void);
177 void xs_suspend_cancel(void);
178
179 struct work_struct;
180
181 void xenbus_probe(struct work_struct *);
182
183 #define XENBUS_IS_ERR_READ(str) ({ \
184 if (!IS_ERR(str) && strlen(str) == 0) { \
185 kfree(str); \
186 str = ERR_PTR(-ERANGE); \
187 } \
188 IS_ERR(str); \
189 })
190
191 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
192
193 int xenbus_watch_path(struct xenbus_device *dev, const char *path,
194 struct xenbus_watch *watch,
195 void (*callback)(struct xenbus_watch *,
196 const char *, const char *));
197 __printf(4, 5)
198 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
199 void (*callback)(struct xenbus_watch *,
200 const char *, const char *),
201 const char *pathfmt, ...);
202
203 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
204 int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
205 unsigned int nr_pages, grant_ref_t *grefs);
206 int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
207 unsigned int nr_grefs, void **vaddr);
208 int xenbus_map_ring(struct xenbus_device *dev,
209 grant_ref_t *gnt_refs, unsigned int nr_grefs,
210 grant_handle_t *handles, unsigned long *vaddrs,
211 bool *leaked);
212
213 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
214 int xenbus_unmap_ring(struct xenbus_device *dev,
215 grant_handle_t *handles, unsigned int nr_handles,
216 unsigned long *vaddrs);
217
218 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
219 int xenbus_free_evtchn(struct xenbus_device *dev, int port);
220
221 enum xenbus_state xenbus_read_driver_state(const char *path);
222
223 __printf(3, 4)
224 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);
225 __printf(3, 4)
226 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...);
227
228 const char *xenbus_strstate(enum xenbus_state state);
229 int xenbus_dev_is_online(struct xenbus_device *dev);
230 int xenbus_frontend_closed(struct xenbus_device *dev);
231
232 extern const struct file_operations xen_xenbus_fops;
233 extern struct xenstore_domain_interface *xen_store_interface;
234 extern int xen_store_evtchn;
235
236 #endif /* _XEN_XENBUS_H */
237
