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 | |
55 | /* Register callback to watch this node. */ |
56 | struct xenbus_watch |
57 | { |
58 | struct list_head list; |
59 | |
60 | /* Path being watched. */ |
61 | const char *node; |
62 | |
63 | unsigned int nr_pending; |
64 | |
65 | /* |
66 | * Called just before enqueing new event while a spinlock is held. |
67 | * The event will be discarded if this callback returns false. |
68 | */ |
69 | bool (*will_handle)(struct xenbus_watch *, |
70 | const char *path, const char *token); |
71 | |
72 | /* Callback (executed in a process context with no locks held). */ |
73 | void (*callback)(struct xenbus_watch *, |
74 | const char *path, const char *token); |
75 | }; |
76 | |
77 | |
78 | /* A xenbus device. */ |
79 | struct xenbus_device { |
80 | const char *devicetype; |
81 | const char *nodename; |
82 | const char *otherend; |
83 | int otherend_id; |
84 | struct xenbus_watch otherend_watch; |
85 | struct device dev; |
86 | enum xenbus_state state; |
87 | struct completion down; |
88 | struct work_struct work; |
89 | struct semaphore reclaim_sem; |
90 | |
91 | /* Event channel based statistics and settings. */ |
92 | atomic_t event_channels; |
93 | atomic_t events; |
94 | atomic_t spurious_events; |
95 | atomic_t jiffies_eoi_delayed; |
96 | unsigned int spurious_threshold; |
97 | }; |
98 | |
99 | #define to_xenbus_device(__dev) container_of_const(__dev, struct xenbus_device, dev) |
100 | |
101 | struct xenbus_device_id |
102 | { |
103 | /* .../device/<device_type>/<identifier> */ |
104 | char devicetype[32]; /* General class of device. */ |
105 | }; |
106 | |
107 | /* A xenbus driver. */ |
108 | struct xenbus_driver { |
109 | const char *name; /* defaults to ids[0].devicetype */ |
110 | const struct xenbus_device_id *ids; |
111 | bool allow_rebind; /* avoid setting xenstore closed during remove */ |
112 | bool not_essential; /* is not mandatory for boot progress */ |
113 | int (*probe)(struct xenbus_device *dev, |
114 | const struct xenbus_device_id *id); |
115 | void (*otherend_changed)(struct xenbus_device *dev, |
116 | enum xenbus_state backend_state); |
117 | void (*remove)(struct xenbus_device *dev); |
118 | int (*suspend)(struct xenbus_device *dev); |
119 | int (*resume)(struct xenbus_device *dev); |
120 | int (*uevent)(const struct xenbus_device *, struct kobj_uevent_env *); |
121 | struct device_driver driver; |
122 | int (*read_otherend_details)(struct xenbus_device *dev); |
123 | int (*is_ready)(struct xenbus_device *dev); |
124 | void (*reclaim_memory)(struct xenbus_device *dev); |
125 | }; |
126 | |
127 | static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) |
128 | { |
129 | return container_of(drv, struct xenbus_driver, driver); |
130 | } |
131 | |
132 | int __must_check __xenbus_register_frontend(struct xenbus_driver *drv, |
133 | struct module *owner, |
134 | const char *mod_name); |
135 | int __must_check __xenbus_register_backend(struct xenbus_driver *drv, |
136 | struct module *owner, |
137 | const char *mod_name); |
138 | |
139 | #define xenbus_register_frontend(drv) \ |
140 | __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME) |
141 | #define xenbus_register_backend(drv) \ |
142 | __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME) |
143 | |
144 | void xenbus_unregister_driver(struct xenbus_driver *drv); |
145 | |
146 | struct xenbus_transaction |
147 | { |
148 | u32 id; |
149 | }; |
150 | |
151 | /* Nil transaction ID. */ |
152 | #define XBT_NIL ((struct xenbus_transaction) { 0 }) |
153 | |
154 | char **xenbus_directory(struct xenbus_transaction t, |
155 | const char *dir, const char *node, unsigned int *num); |
156 | void *xenbus_read(struct xenbus_transaction t, |
157 | const char *dir, const char *node, unsigned int *len); |
158 | int xenbus_write(struct xenbus_transaction t, |
159 | const char *dir, const char *node, const char *string); |
160 | int xenbus_mkdir(struct xenbus_transaction t, |
161 | const char *dir, const char *node); |
162 | int xenbus_exists(struct xenbus_transaction t, |
163 | const char *dir, const char *node); |
164 | int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); |
165 | int xenbus_transaction_start(struct xenbus_transaction *t); |
166 | int xenbus_transaction_end(struct xenbus_transaction t, int abort); |
167 | |
168 | /* Single read and scanf: returns -errno or num scanned if > 0. */ |
169 | __scanf(4, 5) |
170 | int xenbus_scanf(struct xenbus_transaction t, |
171 | const char *dir, const char *node, const char *fmt, ...); |
172 | |
173 | /* Read an (optional) unsigned value. */ |
174 | unsigned int xenbus_read_unsigned(const char *dir, const char *node, |
175 | unsigned int default_val); |
176 | |
177 | /* Single printf and write: returns -errno or 0. */ |
178 | __printf(4, 5) |
179 | int xenbus_printf(struct xenbus_transaction t, |
180 | const char *dir, const char *node, const char *fmt, ...); |
181 | |
182 | /* Generic read function: NULL-terminated triples of name, |
183 | * sprintf-style type string, and pointer. Returns 0 or errno.*/ |
184 | int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); |
185 | |
186 | /* notifer routines for when the xenstore comes up */ |
187 | extern int xenstored_ready; |
188 | int register_xenstore_notifier(struct notifier_block *nb); |
189 | void unregister_xenstore_notifier(struct notifier_block *nb); |
190 | |
191 | int register_xenbus_watch(struct xenbus_watch *watch); |
192 | void unregister_xenbus_watch(struct xenbus_watch *watch); |
193 | void xs_suspend(void); |
194 | void xs_resume(void); |
195 | void xs_suspend_cancel(void); |
196 | |
197 | struct work_struct; |
198 | |
199 | #define XENBUS_IS_ERR_READ(str) ({ \ |
200 | if (!IS_ERR(str) && strlen(str) == 0) { \ |
201 | kfree(str); \ |
202 | str = ERR_PTR(-ERANGE); \ |
203 | } \ |
204 | IS_ERR(str); \ |
205 | }) |
206 | |
207 | #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) |
208 | |
209 | int xenbus_watch_path(struct xenbus_device *dev, const char *path, |
210 | struct xenbus_watch *watch, |
211 | bool (*will_handle)(struct xenbus_watch *, |
212 | const char *, const char *), |
213 | void (*callback)(struct xenbus_watch *, |
214 | const char *, const char *)); |
215 | __printf(5, 6) |
216 | int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, |
217 | bool (*will_handle)(struct xenbus_watch *, |
218 | const char *, const char *), |
219 | void (*callback)(struct xenbus_watch *, |
220 | const char *, const char *), |
221 | const char *pathfmt, ...); |
222 | |
223 | int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); |
224 | int xenbus_setup_ring(struct xenbus_device *dev, gfp_t gfp, void **vaddr, |
225 | unsigned int nr_pages, grant_ref_t *grefs); |
226 | void xenbus_teardown_ring(void **vaddr, unsigned int nr_pages, |
227 | grant_ref_t *grefs); |
228 | int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs, |
229 | unsigned int nr_grefs, void **vaddr); |
230 | |
231 | int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr); |
232 | |
233 | int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port); |
234 | int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t 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 | extern const struct file_operations xen_xenbus_fops; |
248 | extern struct xenstore_domain_interface *xen_store_interface; |
249 | extern int xen_store_evtchn; |
250 | |
251 | #endif /* _XEN_XENBUS_H */ |
252 | |