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. */
55struct 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. */
69struct 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
81static inline struct xenbus_device *to_xenbus_device(struct device *dev)
82{
83 return container_of(dev, struct xenbus_device, dev);
84}
85
86struct xenbus_device_id
87{
88 /* .../device/<device_type>/<identifier> */
89 char devicetype[32]; /* General class of device. */
90};
91
92/* A xenbus driver. */
93struct 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
109static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
110{
111 return container_of(drv, struct xenbus_driver, driver);
112}
113
114int __must_check __xenbus_register_frontend(struct xenbus_driver *drv,
115 struct module *owner,
116 const char *mod_name);
117int __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
126void xenbus_unregister_driver(struct xenbus_driver *drv);
127
128struct xenbus_transaction
129{
130 u32 id;
131};
132
133/* Nil transaction ID. */
134#define XBT_NIL ((struct xenbus_transaction) { 0 })
135
136char **xenbus_directory(struct xenbus_transaction t,
137 const char *dir, const char *node, unsigned int *num);
138void *xenbus_read(struct xenbus_transaction t,
139 const char *dir, const char *node, unsigned int *len);
140int xenbus_write(struct xenbus_transaction t,
141 const char *dir, const char *node, const char *string);
142int xenbus_mkdir(struct xenbus_transaction t,
143 const char *dir, const char *node);
144int xenbus_exists(struct xenbus_transaction t,
145 const char *dir, const char *node);
146int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
147int xenbus_transaction_start(struct xenbus_transaction *t);
148int 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)
152int xenbus_scanf(struct xenbus_transaction t,
153 const char *dir, const char *node, const char *fmt, ...);
154
155/* Read an (optional) unsigned value. */
156unsigned 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)
161int 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.*/
166int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
167
168/* notifer routines for when the xenstore comes up */
169extern int xenstored_ready;
170int register_xenstore_notifier(struct notifier_block *nb);
171void unregister_xenstore_notifier(struct notifier_block *nb);
172
173int register_xenbus_watch(struct xenbus_watch *watch);
174void unregister_xenbus_watch(struct xenbus_watch *watch);
175void xs_suspend(void);
176void xs_resume(void);
177void xs_suspend_cancel(void);
178
179struct work_struct;
180
181void 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
193int 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)
198int 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
203int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
204int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
205 unsigned int nr_pages, grant_ref_t *grefs);
206int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
207 unsigned int nr_grefs, void **vaddr);
208int 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
213int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
214int xenbus_unmap_ring(struct xenbus_device *dev,
215 grant_handle_t *handles, unsigned int nr_handles,
216 unsigned long *vaddrs);
217
218int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
219int xenbus_free_evtchn(struct xenbus_device *dev, int port);
220
221enum xenbus_state xenbus_read_driver_state(const char *path);
222
223__printf(3, 4)
224void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);
225__printf(3, 4)
226void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...);
227
228const char *xenbus_strstate(enum xenbus_state state);
229int xenbus_dev_is_online(struct xenbus_device *dev);
230int xenbus_frontend_closed(struct xenbus_device *dev);
231
232extern const struct file_operations xen_xenbus_fops;
233extern struct xenstore_domain_interface *xen_store_interface;
234extern int xen_store_evtchn;
235
236#endif /* _XEN_XENBUS_H */
237