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. */ 55 struct 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. */ 69 struct 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 81 static inline struct xenbus_device *to_xenbus_device(struct device *dev) 82 { 83 return container_of(dev, struct xenbus_device, dev); 84 } 85 86 struct xenbus_device_id 87 { 88 /* .../device/<device_type>/<identifier> */ 89 char devicetype[32]; /* General class of device. */ 90 }; 91 92 /* A xenbus driver. */ 93 struct xenbus_driver { 94 const char *name; /* defaults to ids[0].devicetype */ 95 const struct xenbus_device_id *ids; 96 bool allow_rebind; /* avoid setting xenstore closed during remove */ 97 int (*probe)(struct xenbus_device *dev, 98 const struct xenbus_device_id *id); 99 void (*otherend_changed)(struct xenbus_device *dev, 100 enum xenbus_state backend_state); 101 int (*remove)(struct xenbus_device *dev); 102 int (*suspend)(struct xenbus_device *dev); 103 int (*resume)(struct xenbus_device *dev); 104 int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *); 105 struct device_driver driver; 106 int (*read_otherend_details)(struct xenbus_device *dev); 107 int (*is_ready)(struct xenbus_device *dev); 108 }; 109 110 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) 111 { 112 return container_of(drv, struct xenbus_driver, driver); 113 } 114 115 int __must_check __xenbus_register_frontend(struct xenbus_driver *drv, 116 struct module *owner, 117 const char *mod_name); 118 int __must_check __xenbus_register_backend(struct xenbus_driver *drv, 119 struct module *owner, 120 const char *mod_name); 121 122 #define xenbus_register_frontend(drv) \ 123 __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME) 124 #define xenbus_register_backend(drv) \ 125 __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME) 126 127 void xenbus_unregister_driver(struct xenbus_driver *drv); 128 129 struct xenbus_transaction 130 { 131 u32 id; 132 }; 133 134 /* Nil transaction ID. */ 135 #define XBT_NIL ((struct xenbus_transaction) { 0 }) 136 137 char **xenbus_directory(struct xenbus_transaction t, 138 const char *dir, const char *node, unsigned int *num); 139 void *xenbus_read(struct xenbus_transaction t, 140 const char *dir, const char *node, unsigned int *len); 141 int xenbus_write(struct xenbus_transaction t, 142 const char *dir, const char *node, const char *string); 143 int xenbus_mkdir(struct xenbus_transaction t, 144 const char *dir, const char *node); 145 int xenbus_exists(struct xenbus_transaction t, 146 const char *dir, const char *node); 147 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); 148 int xenbus_transaction_start(struct xenbus_transaction *t); 149 int xenbus_transaction_end(struct xenbus_transaction t, int abort); 150 151 /* Single read and scanf: returns -errno or num scanned if > 0. */ 152 __scanf(4, 5) 153 int xenbus_scanf(struct xenbus_transaction t, 154 const char *dir, const char *node, const char *fmt, ...); 155 156 /* Read an (optional) unsigned value. */ 157 unsigned int xenbus_read_unsigned(const char *dir, const char *node, 158 unsigned int default_val); 159 160 /* Single printf and write: returns -errno or 0. */ 161 __printf(4, 5) 162 int xenbus_printf(struct xenbus_transaction t, 163 const char *dir, const char *node, const char *fmt, ...); 164 165 /* Generic read function: NULL-terminated triples of name, 166 * sprintf-style type string, and pointer. Returns 0 or errno.*/ 167 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); 168 169 /* notifer routines for when the xenstore comes up */ 170 extern int xenstored_ready; 171 int register_xenstore_notifier(struct notifier_block *nb); 172 void unregister_xenstore_notifier(struct notifier_block *nb); 173 174 int register_xenbus_watch(struct xenbus_watch *watch); 175 void unregister_xenbus_watch(struct xenbus_watch *watch); 176 void xs_suspend(void); 177 void xs_resume(void); 178 void xs_suspend_cancel(void); 179 180 struct work_struct; 181 182 void xenbus_probe(struct work_struct *); 183 184 #define XENBUS_IS_ERR_READ(str) ({ \ 185 if (!IS_ERR(str) && strlen(str) == 0) { \ 186 kfree(str); \ 187 str = ERR_PTR(-ERANGE); \ 188 } \ 189 IS_ERR(str); \ 190 }) 191 192 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 193 194 int xenbus_watch_path(struct xenbus_device *dev, const char *path, 195 struct xenbus_watch *watch, 196 void (*callback)(struct xenbus_watch *, 197 const char *, const char *)); 198 __printf(4, 5) 199 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, 200 void (*callback)(struct xenbus_watch *, 201 const char *, const char *), 202 const char *pathfmt, ...); 203 204 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); 205 int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr, 206 unsigned int nr_pages, grant_ref_t *grefs); 207 int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs, 208 unsigned int nr_grefs, void **vaddr); 209 int xenbus_map_ring(struct xenbus_device *dev, 210 grant_ref_t *gnt_refs, unsigned int nr_grefs, 211 grant_handle_t *handles, unsigned long *vaddrs, 212 bool *leaked); 213 214 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr); 215 int xenbus_unmap_ring(struct xenbus_device *dev, 216 grant_handle_t *handles, unsigned int nr_handles, 217 unsigned long *vaddrs); 218 219 int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port); 220 int xenbus_free_evtchn(struct xenbus_device *dev, int port); 221 222 enum xenbus_state xenbus_read_driver_state(const char *path); 223 224 __printf(3, 4) 225 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...); 226 __printf(3, 4) 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 extern const struct file_operations xen_xenbus_fops; 234 extern struct xenstore_domain_interface *xen_store_interface; 235 extern int xen_store_evtchn; 236 237 #endif /* _XEN_XENBUS_H */ 238