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/completion.h> 41 #include <linux/init.h> 42 #include <linux/slab.h> 43 #include <xen/interface/xen.h> 44 #include <xen/interface/grant_table.h> 45 #include <xen/interface/io/xenbus.h> 46 #include <xen/interface/io/xs_wire.h> 47 48 /* Register callback to watch this node. */ 49 struct xenbus_watch 50 { 51 struct list_head list; 52 53 /* Path being watched. */ 54 const char *node; 55 56 /* Callback (executed in a process context with no locks held). */ 57 void (*callback)(struct xenbus_watch *, 58 const char **vec, unsigned int len); 59 }; 60 61 62 /* A xenbus device. */ 63 struct xenbus_device { 64 const char *devicetype; 65 const char *nodename; 66 const char *otherend; 67 int otherend_id; 68 struct xenbus_watch otherend_watch; 69 struct device dev; 70 enum xenbus_state state; 71 struct completion down; 72 }; 73 74 static inline struct xenbus_device *to_xenbus_device(struct device *dev) 75 { 76 return container_of(dev, struct xenbus_device, dev); 77 } 78 79 struct xenbus_device_id 80 { 81 /* .../device/<device_type>/<identifier> */ 82 char devicetype[32]; /* General class of device. */ 83 }; 84 85 /* A xenbus driver. */ 86 struct xenbus_driver { 87 char *name; 88 struct module *owner; 89 const struct xenbus_device_id *ids; 90 int (*probe)(struct xenbus_device *dev, 91 const struct xenbus_device_id *id); 92 void (*otherend_changed)(struct xenbus_device *dev, 93 enum xenbus_state backend_state); 94 int (*remove)(struct xenbus_device *dev); 95 int (*suspend)(struct xenbus_device *dev); 96 int (*resume)(struct xenbus_device *dev); 97 int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *); 98 struct device_driver driver; 99 int (*read_otherend_details)(struct xenbus_device *dev); 100 int (*is_ready)(struct xenbus_device *dev); 101 }; 102 103 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) 104 { 105 return container_of(drv, struct xenbus_driver, driver); 106 } 107 108 int __must_check __xenbus_register_frontend(struct xenbus_driver *drv, 109 struct module *owner, 110 const char *mod_name); 111 112 static inline int __must_check 113 xenbus_register_frontend(struct xenbus_driver *drv) 114 { 115 WARN_ON(drv->owner != THIS_MODULE); 116 return __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME); 117 } 118 119 int __must_check __xenbus_register_backend(struct xenbus_driver *drv, 120 struct module *owner, 121 const char *mod_name); 122 static inline int __must_check 123 xenbus_register_backend(struct xenbus_driver *drv) 124 { 125 WARN_ON(drv->owner != THIS_MODULE); 126 return __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME); 127 } 128 129 void xenbus_unregister_driver(struct xenbus_driver *drv); 130 131 struct xenbus_transaction 132 { 133 u32 id; 134 }; 135 136 /* Nil transaction ID. */ 137 #define XBT_NIL ((struct xenbus_transaction) { 0 }) 138 139 char **xenbus_directory(struct xenbus_transaction t, 140 const char *dir, const char *node, unsigned int *num); 141 void *xenbus_read(struct xenbus_transaction t, 142 const char *dir, const char *node, unsigned int *len); 143 int xenbus_write(struct xenbus_transaction t, 144 const char *dir, const char *node, const char *string); 145 int xenbus_mkdir(struct xenbus_transaction t, 146 const char *dir, const char *node); 147 int xenbus_exists(struct xenbus_transaction t, 148 const char *dir, const char *node); 149 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); 150 int xenbus_transaction_start(struct xenbus_transaction *t); 151 int xenbus_transaction_end(struct xenbus_transaction t, int abort); 152 153 /* Single read and scanf: returns -errno or num scanned if > 0. */ 154 int xenbus_scanf(struct xenbus_transaction t, 155 const char *dir, const char *node, const char *fmt, ...) 156 __attribute__((format(scanf, 4, 5))); 157 158 /* Single printf and write: returns -errno or 0. */ 159 int xenbus_printf(struct xenbus_transaction t, 160 const char *dir, const char *node, const char *fmt, ...) 161 __attribute__((format(printf, 4, 5))); 162 163 /* Generic read function: NULL-terminated triples of name, 164 * sprintf-style type string, and pointer. Returns 0 or errno.*/ 165 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); 166 167 /* notifer routines for when the xenstore comes up */ 168 extern int xenstored_ready; 169 int register_xenstore_notifier(struct notifier_block *nb); 170 void unregister_xenstore_notifier(struct notifier_block *nb); 171 172 int register_xenbus_watch(struct xenbus_watch *watch); 173 void unregister_xenbus_watch(struct xenbus_watch *watch); 174 void xs_suspend(void); 175 void xs_resume(void); 176 void xs_suspend_cancel(void); 177 178 /* Used by xenbus_dev to borrow kernel's store connection. */ 179 void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg); 180 181 struct work_struct; 182 183 /* Prepare for domain suspend: then resume or cancel the suspend. */ 184 void xenbus_suspend(void); 185 void xenbus_resume(void); 186 void xenbus_probe(struct work_struct *); 187 void xenbus_suspend_cancel(void); 188 189 #define XENBUS_IS_ERR_READ(str) ({ \ 190 if (!IS_ERR(str) && strlen(str) == 0) { \ 191 kfree(str); \ 192 str = ERR_PTR(-ERANGE); \ 193 } \ 194 IS_ERR(str); \ 195 }) 196 197 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 198 199 int xenbus_watch_path(struct xenbus_device *dev, const char *path, 200 struct xenbus_watch *watch, 201 void (*callback)(struct xenbus_watch *, 202 const char **, unsigned int)); 203 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, 204 void (*callback)(struct xenbus_watch *, 205 const char **, unsigned int), 206 const char *pathfmt, ...) 207 __attribute__ ((format (printf, 4, 5))); 208 209 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); 210 int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn); 211 int xenbus_map_ring_valloc(struct xenbus_device *dev, 212 int gnt_ref, void **vaddr); 213 int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref, 214 grant_handle_t *handle, void *vaddr); 215 216 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr); 217 int xenbus_unmap_ring(struct xenbus_device *dev, 218 grant_handle_t handle, void *vaddr); 219 220 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port); 221 int xenbus_bind_evtchn(struct xenbus_device *dev, int remote_port, int *port); 222 int xenbus_free_evtchn(struct xenbus_device *dev, int port); 223 224 enum xenbus_state xenbus_read_driver_state(const char *path); 225 226 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...); 227 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...); 228 229 const char *xenbus_strstate(enum xenbus_state state); 230 int xenbus_dev_is_online(struct xenbus_device *dev); 231 int xenbus_frontend_closed(struct xenbus_device *dev); 232 233 #endif /* _XEN_XENBUS_H */ 234