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 #define to_xenbus_driver(__drv) container_of_const(__drv, struct xenbus_driver, driver) 128 129 int __must_check __xenbus_register_frontend(struct xenbus_driver *drv, 130 struct module *owner, 131 const char *mod_name); 132 int __must_check __xenbus_register_backend(struct xenbus_driver *drv, 133 struct module *owner, 134 const char *mod_name); 135 136 #define xenbus_register_frontend(drv) \ 137 __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME) 138 #define xenbus_register_backend(drv) \ 139 __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME) 140 141 void xenbus_unregister_driver(struct xenbus_driver *drv); 142 143 struct xenbus_transaction 144 { 145 u32 id; 146 }; 147 148 /* Nil transaction ID. */ 149 #define XBT_NIL ((struct xenbus_transaction) { 0 }) 150 151 char **xenbus_directory(struct xenbus_transaction t, 152 const char *dir, const char *node, unsigned int *num); 153 void *xenbus_read(struct xenbus_transaction t, 154 const char *dir, const char *node, unsigned int *len); 155 int xenbus_write(struct xenbus_transaction t, 156 const char *dir, const char *node, const char *string); 157 int xenbus_exists(struct xenbus_transaction t, 158 const char *dir, const char *node); 159 int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node); 160 int xenbus_transaction_start(struct xenbus_transaction *t); 161 int xenbus_transaction_end(struct xenbus_transaction t, int abort); 162 163 /* Single read and scanf: returns -errno or num scanned if > 0. */ 164 __scanf(4, 5) 165 int xenbus_scanf(struct xenbus_transaction t, 166 const char *dir, const char *node, const char *fmt, ...); 167 168 /* Read an (optional) unsigned value. */ 169 unsigned int xenbus_read_unsigned(const char *dir, const char *node, 170 unsigned int default_val); 171 172 /* Single printf and write: returns -errno or 0. */ 173 __printf(4, 5) 174 int xenbus_printf(struct xenbus_transaction t, 175 const char *dir, const char *node, const char *fmt, ...); 176 177 /* Generic read function: NULL-terminated triples of name, 178 * sprintf-style type string, and pointer. Returns 0 or errno.*/ 179 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...); 180 181 /* notifier routines for when the xenstore comes up */ 182 extern int xenstored_ready; 183 int register_xenstore_notifier(struct notifier_block *nb); 184 void unregister_xenstore_notifier(struct notifier_block *nb); 185 186 int register_xenbus_watch(struct xenbus_watch *watch); 187 void unregister_xenbus_watch(struct xenbus_watch *watch); 188 void xs_suspend(void); 189 void xs_resume(void); 190 void xs_suspend_cancel(void); 191 192 struct work_struct; 193 194 #define XENBUS_IS_ERR_READ(str) ({ \ 195 if (!IS_ERR(str) && strlen(str) == 0) { \ 196 kfree(str); \ 197 str = ERR_PTR(-ERANGE); \ 198 } \ 199 IS_ERR(str); \ 200 }) 201 202 #define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE) 203 204 int xenbus_watch_path(struct xenbus_device *dev, const char *path, 205 struct xenbus_watch *watch, 206 bool (*will_handle)(struct xenbus_watch *, 207 const char *, const char *), 208 void (*callback)(struct xenbus_watch *, 209 const char *, const char *)); 210 __printf(5, 6) 211 int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch, 212 bool (*will_handle)(struct xenbus_watch *, 213 const char *, const char *), 214 void (*callback)(struct xenbus_watch *, 215 const char *, const char *), 216 const char *pathfmt, ...); 217 218 int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state); 219 int xenbus_setup_ring(struct xenbus_device *dev, gfp_t gfp, void **vaddr, 220 unsigned int nr_pages, grant_ref_t *grefs); 221 void xenbus_teardown_ring(void **vaddr, unsigned int nr_pages, 222 grant_ref_t *grefs); 223 int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs, 224 unsigned int nr_grefs, void **vaddr); 225 226 int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr); 227 228 int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port); 229 int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t port); 230 231 enum xenbus_state xenbus_read_driver_state(const char *path); 232 233 __printf(3, 4) 234 void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...); 235 __printf(3, 4) 236 void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...); 237 238 const char *xenbus_strstate(enum xenbus_state state); 239 int xenbus_dev_is_online(struct xenbus_device *dev); 240 int xenbus_frontend_closed(struct xenbus_device *dev); 241 242 extern const struct file_operations xen_xenbus_fops; 243 extern struct xenstore_domain_interface *xen_store_interface; 244 extern int xen_store_evtchn; 245 246 #endif /* _XEN_XENBUS_H */ 247