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 spinlock_t reclaim_lock; 80 }; 81 82 static inline struct xenbus_device *to_xenbus_device(struct device *dev) 83 { 84 return container_of(dev, struct xenbus_device, dev); 85 } 86 87 struct xenbus_device_id 88 { 89 /* .../device/<device_type>/<identifier> */ 90 char devicetype[32]; /* General class of device. */ 91 }; 92 93 /* A xenbus driver. */ 94 struct xenbus_driver { 95 const char *name; /* defaults to ids[0].devicetype */ 96 const struct xenbus_device_id *ids; 97 bool allow_rebind; /* avoid setting xenstore closed during remove */ 98 int (*probe)(struct xenbus_device *dev, 99 const struct xenbus_device_id *id); 100 void (*otherend_changed)(struct xenbus_device *dev, 101 enum xenbus_state backend_state); 102 int (*remove)(struct xenbus_device *dev); 103 int (*suspend)(struct xenbus_device *dev); 104 int (*resume)(struct xenbus_device *dev); 105 int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *); 106 struct device_driver driver; 107 int (*read_otherend_details)(struct xenbus_device *dev); 108 int (*is_ready)(struct xenbus_device *dev); 109 void (*reclaim_memory)(struct xenbus_device *dev); 110 }; 111 112 static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv) 113 { 114 return container_of(drv, struct xenbus_driver, driver); 115 } 116 117 int __must_check __xenbus_register_frontend(struct xenbus_driver *drv, 118 struct module *owner, 119 const char *mod_name); 120 int __must_check __xenbus_register_backend(struct xenbus_driver *drv, 121 struct module *owner, 122 const char *mod_name); 123 124 #define xenbus_register_frontend(drv) \ 125 __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME) 126 #define xenbus_register_backend(drv) \ 127 __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME) 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 __scanf(4, 5) 155 int xenbus_scanf(struct xenbus_transaction t, 156 const char *dir, const char *node, const char *fmt, ...); 157 158 /* Read an (optional) unsigned value. */ 159 unsigned int xenbus_read_unsigned(const char *dir, const char *node, 160 unsigned int default_val); 161 162 /* Single printf and write: returns -errno or 0. */ 163 __printf(4, 5) 164 int xenbus_printf(struct xenbus_transaction t, 165 const char *dir, const char *node, const char *fmt, ...); 166 167 /* Generic read function: NULL-terminated triples of name, 168 * sprintf-style type string, and pointer. Returns 0 or errno.*/ 169 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); 170 171 /* notifer routines for when the xenstore comes up */ 172 extern int xenstored_ready; 173 int register_xenstore_notifier(struct notifier_block *nb); 174 void unregister_xenstore_notifier(struct notifier_block *nb); 175 176 int register_xenbus_watch(struct xenbus_watch *watch); 177 void unregister_xenbus_watch(struct xenbus_watch *watch); 178 void xs_suspend(void); 179 void xs_resume(void); 180 void xs_suspend_cancel(void); 181 182 struct work_struct; 183 184 void xenbus_probe(struct work_struct *); 185 186 #define XENBUS_IS_ERR_READ(str) ({ \ 187 if (!IS_ERR(str) && strlen(str) == 0) { \ 188 kfree(str); \ 189 str = ERR_PTR(-ERANGE); \ 190 } \ 191 IS_ERR(str); \ 192 }) 193 194 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 195 196 int xenbus_watch_path(struct xenbus_device *dev, const char *path, 197 struct xenbus_watch *watch, 198 void (*callback)(struct xenbus_watch *, 199 const char *, const char *)); 200 __printf(4, 5) 201 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, 202 void (*callback)(struct xenbus_watch *, 203 const char *, const char *), 204 const char *pathfmt, ...); 205 206 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); 207 int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr, 208 unsigned int nr_pages, grant_ref_t *grefs); 209 int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs, 210 unsigned int nr_grefs, void **vaddr); 211 int xenbus_map_ring(struct xenbus_device *dev, 212 grant_ref_t *gnt_refs, unsigned int nr_grefs, 213 grant_handle_t *handles, unsigned long *vaddrs, 214 bool *leaked); 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 *handles, unsigned int nr_handles, 219 unsigned long *vaddrs); 220 221 int xenbus_alloc_evtchn(struct xenbus_device *dev, 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 __printf(3, 4) 227 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...); 228 __printf(3, 4) 229 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...); 230 231 const char *xenbus_strstate(enum xenbus_state state); 232 int xenbus_dev_is_online(struct xenbus_device *dev); 233 int xenbus_frontend_closed(struct xenbus_device *dev); 234 235 extern const struct file_operations xen_xenbus_fops; 236 extern struct xenstore_domain_interface *xen_store_interface; 237 extern int xen_store_evtchn; 238 239 #endif /* _XEN_XENBUS_H */ 240