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