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/completion.h> 42 #include <linux/init.h> 43 #include <linux/slab.h> 44 #include <xen/interface/xen.h> 45 #include <xen/interface/grant_table.h> 46 #include <xen/interface/io/xenbus.h> 47 #include <xen/interface/io/xs_wire.h> 48 49 /* Register callback to watch this node. */ 50 struct xenbus_watch 51 { 52 struct list_head list; 53 54 /* Path being watched. */ 55 const char *node; 56 57 /* Callback (executed in a process context with no locks held). */ 58 void (*callback)(struct xenbus_watch *, 59 const char **vec, unsigned int len); 60 }; 61 62 63 /* A xenbus device. */ 64 struct xenbus_device { 65 const char *devicetype; 66 const char *nodename; 67 const char *otherend; 68 int otherend_id; 69 struct xenbus_watch otherend_watch; 70 struct device dev; 71 enum xenbus_state state; 72 struct completion down; 73 struct work_struct work; 74 }; 75 76 static inline struct xenbus_device *to_xenbus_device(struct device *dev) 77 { 78 return container_of(dev, struct xenbus_device, dev); 79 } 80 81 struct xenbus_device_id 82 { 83 /* .../device/<device_type>/<identifier> */ 84 char devicetype[32]; /* General class of device. */ 85 }; 86 87 /* A xenbus driver. */ 88 struct xenbus_driver { 89 const char *name; /* defaults to ids[0].devicetype */ 90 const struct xenbus_device_id *ids; 91 int (*probe)(struct xenbus_device *dev, 92 const struct xenbus_device_id *id); 93 void (*otherend_changed)(struct xenbus_device *dev, 94 enum xenbus_state backend_state); 95 int (*remove)(struct xenbus_device *dev); 96 int (*suspend)(struct xenbus_device *dev); 97 int (*resume)(struct xenbus_device *dev); 98 int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *); 99 struct device_driver driver; 100 int (*read_otherend_details)(struct xenbus_device *dev); 101 int (*is_ready)(struct xenbus_device *dev); 102 }; 103 104 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) 105 { 106 return container_of(drv, struct xenbus_driver, driver); 107 } 108 109 int __must_check __xenbus_register_frontend(struct xenbus_driver *drv, 110 struct module *owner, 111 const char *mod_name); 112 int __must_check __xenbus_register_backend(struct xenbus_driver *drv, 113 struct module *owner, 114 const char *mod_name); 115 116 #define xenbus_register_frontend(drv) \ 117 __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME); 118 #define xenbus_register_backend(drv) \ 119 __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME); 120 121 void xenbus_unregister_driver(struct xenbus_driver *drv); 122 123 struct xenbus_transaction 124 { 125 u32 id; 126 }; 127 128 /* Nil transaction ID. */ 129 #define XBT_NIL ((struct xenbus_transaction) { 0 }) 130 131 char **xenbus_directory(struct xenbus_transaction t, 132 const char *dir, const char *node, unsigned int *num); 133 void *xenbus_read(struct xenbus_transaction t, 134 const char *dir, const char *node, unsigned int *len); 135 int xenbus_write(struct xenbus_transaction t, 136 const char *dir, const char *node, const char *string); 137 int xenbus_mkdir(struct xenbus_transaction t, 138 const char *dir, const char *node); 139 int xenbus_exists(struct xenbus_transaction t, 140 const char *dir, const char *node); 141 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); 142 int xenbus_transaction_start(struct xenbus_transaction *t); 143 int xenbus_transaction_end(struct xenbus_transaction t, int abort); 144 145 /* Single read and scanf: returns -errno or num scanned if > 0. */ 146 __scanf(4, 5) 147 int xenbus_scanf(struct xenbus_transaction t, 148 const char *dir, const char *node, const char *fmt, ...); 149 150 /* Single printf and write: returns -errno or 0. */ 151 __printf(4, 5) 152 int xenbus_printf(struct xenbus_transaction t, 153 const char *dir, const char *node, const char *fmt, ...); 154 155 /* Generic read function: NULL-terminated triples of name, 156 * sprintf-style type string, and pointer. Returns 0 or errno.*/ 157 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); 158 159 /* notifer routines for when the xenstore comes up */ 160 extern int xenstored_ready; 161 int register_xenstore_notifier(struct notifier_block *nb); 162 void unregister_xenstore_notifier(struct notifier_block *nb); 163 164 int register_xenbus_watch(struct xenbus_watch *watch); 165 void unregister_xenbus_watch(struct xenbus_watch *watch); 166 void xs_suspend(void); 167 void xs_resume(void); 168 void xs_suspend_cancel(void); 169 170 /* Used by xenbus_dev to borrow kernel's store connection. */ 171 void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg); 172 173 struct work_struct; 174 175 /* Prepare for domain suspend: then resume or cancel the suspend. */ 176 void xenbus_suspend(void); 177 void xenbus_resume(void); 178 void xenbus_probe(struct work_struct *); 179 void xenbus_suspend_cancel(void); 180 181 #define XENBUS_IS_ERR_READ(str) ({ \ 182 if (!IS_ERR(str) && strlen(str) == 0) { \ 183 kfree(str); \ 184 str = ERR_PTR(-ERANGE); \ 185 } \ 186 IS_ERR(str); \ 187 }) 188 189 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 190 191 int xenbus_watch_path(struct xenbus_device *dev, const char *path, 192 struct xenbus_watch *watch, 193 void (*callback)(struct xenbus_watch *, 194 const char **, unsigned int)); 195 __printf(4, 5) 196 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, 197 void (*callback)(struct xenbus_watch *, 198 const char **, unsigned int), 199 const char *pathfmt, ...); 200 201 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); 202 int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn); 203 int xenbus_map_ring_valloc(struct xenbus_device *dev, 204 int gnt_ref, void **vaddr); 205 int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref, 206 grant_handle_t *handle, void *vaddr); 207 208 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr); 209 int xenbus_unmap_ring(struct xenbus_device *dev, 210 grant_handle_t handle, void *vaddr); 211 212 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port); 213 int xenbus_free_evtchn(struct xenbus_device *dev, int port); 214 215 enum xenbus_state xenbus_read_driver_state(const char *path); 216 217 __printf(3, 4) 218 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...); 219 __printf(3, 4) 220 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...); 221 222 const char *xenbus_strstate(enum xenbus_state state); 223 int xenbus_dev_is_online(struct xenbus_device *dev); 224 int xenbus_frontend_closed(struct xenbus_device *dev); 225 226 #endif /* _XEN_XENBUS_H */ 227