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 unsigned int nr_pending;
63
64 /*
65 * Called just before enqueing new event while a spinlock is held.
66 * The event will be discarded if this callback returns false.
67 */
68 bool (*will_handle)(struct xenbus_watch *,
69 const char *path, const char *token);
70
71 /* Callback (executed in a process context with no locks held). */
72 void (*callback)(struct xenbus_watch *,
73 const char *path, const char *token);
74 };
75
76
77 /* A xenbus device. */
78 struct xenbus_device {
79 const char *devicetype;
80 const char *nodename;
81 const char *otherend;
82 int otherend_id;
83 struct xenbus_watch otherend_watch;
84 struct device dev;
85 enum xenbus_state state;
86 struct completion down;
87 struct work_struct work;
88 };
89
to_xenbus_device(struct device * dev)90 static inline struct xenbus_device *to_xenbus_device(struct device *dev)
91 {
92 return container_of(dev, struct xenbus_device, dev);
93 }
94
95 struct xenbus_device_id
96 {
97 /* .../device/<device_type>/<identifier> */
98 char devicetype[32]; /* General class of device. */
99 };
100
101 /* A xenbus driver. */
102 struct xenbus_driver {
103 const char *name; /* defaults to ids[0].devicetype */
104 const struct xenbus_device_id *ids;
105 int (*probe)(struct xenbus_device *dev,
106 const struct xenbus_device_id *id);
107 void (*otherend_changed)(struct xenbus_device *dev,
108 enum xenbus_state backend_state);
109 int (*remove)(struct xenbus_device *dev);
110 int (*suspend)(struct xenbus_device *dev);
111 int (*resume)(struct xenbus_device *dev);
112 int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *);
113 struct device_driver driver;
114 int (*read_otherend_details)(struct xenbus_device *dev);
115 int (*is_ready)(struct xenbus_device *dev);
116 };
117
to_xenbus_driver(struct device_driver * drv)118 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
119 {
120 return container_of(drv, struct xenbus_driver, driver);
121 }
122
123 int __must_check __xenbus_register_frontend(struct xenbus_driver *drv,
124 struct module *owner,
125 const char *mod_name);
126 int __must_check __xenbus_register_backend(struct xenbus_driver *drv,
127 struct module *owner,
128 const char *mod_name);
129
130 #define xenbus_register_frontend(drv) \
131 __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME)
132 #define xenbus_register_backend(drv) \
133 __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME)
134
135 void xenbus_unregister_driver(struct xenbus_driver *drv);
136
137 struct xenbus_transaction
138 {
139 u32 id;
140 };
141
142 /* Nil transaction ID. */
143 #define XBT_NIL ((struct xenbus_transaction) { 0 })
144
145 char **xenbus_directory(struct xenbus_transaction t,
146 const char *dir, const char *node, unsigned int *num);
147 void *xenbus_read(struct xenbus_transaction t,
148 const char *dir, const char *node, unsigned int *len);
149 int xenbus_write(struct xenbus_transaction t,
150 const char *dir, const char *node, const char *string);
151 int xenbus_mkdir(struct xenbus_transaction t,
152 const char *dir, const char *node);
153 int xenbus_exists(struct xenbus_transaction t,
154 const char *dir, const char *node);
155 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
156 int xenbus_transaction_start(struct xenbus_transaction *t);
157 int xenbus_transaction_end(struct xenbus_transaction t, int abort);
158
159 /* Single read and scanf: returns -errno or num scanned if > 0. */
160 __scanf(4, 5)
161 int xenbus_scanf(struct xenbus_transaction t,
162 const char *dir, const char *node, const char *fmt, ...);
163
164 /* Read an (optional) unsigned value. */
165 unsigned int xenbus_read_unsigned(const char *dir, const char *node,
166 unsigned int default_val);
167
168 /* Single printf and write: returns -errno or 0. */
169 __printf(4, 5)
170 int xenbus_printf(struct xenbus_transaction t,
171 const char *dir, const char *node, const char *fmt, ...);
172
173 /* Generic read function: NULL-terminated triples of name,
174 * sprintf-style type string, and pointer. Returns 0 or errno.*/
175 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
176
177 /* notifer routines for when the xenstore comes up */
178 extern int xenstored_ready;
179 int register_xenstore_notifier(struct notifier_block *nb);
180 void unregister_xenstore_notifier(struct notifier_block *nb);
181
182 int register_xenbus_watch(struct xenbus_watch *watch);
183 void unregister_xenbus_watch(struct xenbus_watch *watch);
184 void xs_suspend(void);
185 void xs_resume(void);
186 void xs_suspend_cancel(void);
187
188 struct work_struct;
189
190 #define XENBUS_IS_ERR_READ(str) ({ \
191 if (!IS_ERR(str) && strlen(str) == 0) { \
192 kfree(str); \
193 str = ERR_PTR(-ERANGE); \
194 } \
195 IS_ERR(str); \
196 })
197
198 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
199
200 int xenbus_watch_path(struct xenbus_device *dev, const char *path,
201 struct xenbus_watch *watch,
202 bool (*will_handle)(struct xenbus_watch *,
203 const char *, const char *),
204 void (*callback)(struct xenbus_watch *,
205 const char *, const char *));
206 __printf(5, 6)
207 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
208 bool (*will_handle)(struct xenbus_watch *,
209 const char *, const char *),
210 void (*callback)(struct xenbus_watch *,
211 const char *, const char *),
212 const char *pathfmt, ...);
213
214 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
215 int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
216 unsigned int nr_pages, grant_ref_t *grefs);
217 int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
218 unsigned int nr_grefs, void **vaddr);
219 int xenbus_map_ring(struct xenbus_device *dev,
220 grant_ref_t *gnt_refs, unsigned int nr_grefs,
221 grant_handle_t *handles, unsigned long *vaddrs,
222 bool *leaked);
223
224 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
225 int xenbus_unmap_ring(struct xenbus_device *dev,
226 grant_handle_t *handles, unsigned int nr_handles,
227 unsigned long *vaddrs);
228
229 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
230 int xenbus_free_evtchn(struct xenbus_device *dev, int port);
231
232 enum xenbus_state xenbus_read_driver_state(const char *path);
233
234 __printf(3, 4)
235 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);
236 __printf(3, 4)
237 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...);
238
239 const char *xenbus_strstate(enum xenbus_state state);
240 int xenbus_dev_is_online(struct xenbus_device *dev);
241 int xenbus_frontend_closed(struct xenbus_device *dev);
242
243 extern const struct file_operations xen_xenbus_fops;
244 extern struct xenstore_domain_interface *xen_store_interface;
245 extern int xen_store_evtchn;
246
247 #endif /* _XEN_XENBUS_H */
248