LXR linux/include/xen/xenbus.h

   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 <xen/interface/xen.h>
  43#include <xen/interface/grant_table.h>
  44#include <xen/interface/io/xenbus.h>
  45#include <xen/interface/io/xs_wire.h>
  46
  47/* Register callback to watch this node. */
  48struct xenbus_watch
  49{
  50        struct list_head list;
  51
  52        /* Path being watched. */
  53        const char *node;
  54
  55        /* Callback (executed in a process context with no locks held). */
  56        void (*callback)(struct xenbus_watch *,
  57                         const char **vec, unsigned int len);
  58};
  59
  60
  61/* A xenbus device. */
  62struct xenbus_device {
  63        const char *devicetype;
  64        const char *nodename;
  65        const char *otherend;
  66        int otherend_id;
  67        struct xenbus_watch otherend_watch;
  68        struct device dev;
  69        enum xenbus_state state;
  70        struct completion down;
  71};
  72
  73static inline struct xenbus_device *to_xenbus_device(struct device *dev)
  74{
  75        return container_of(dev, struct xenbus_device, dev);
  76}
  77
  78struct xenbus_device_id
  79{
  80        /* .../device/<device_type>/<identifier> */
  81        char devicetype[32];    /* General class of device. */
  82};
  83
  84/* A xenbus driver. */
  85struct xenbus_driver {
  86        char *name;
  87        struct module *owner;
  88        const struct xenbus_device_id *ids;
  89        int (*probe)(struct xenbus_device *dev,
  90                     const struct xenbus_device_id *id);
  91        void (*otherend_changed)(struct xenbus_device *dev,
  92                                 enum xenbus_state backend_state);
  93        int (*remove)(struct xenbus_device *dev);
  94        int (*suspend)(struct xenbus_device *dev);
  95        int (*suspend_cancel)(struct xenbus_device *dev);
  96        int (*resume)(struct xenbus_device *dev);
  97        int (*uevent)(struct xenbus_device *, char **, int, char *, int);
  98        struct device_driver driver;
  99        int (*read_otherend_details)(struct xenbus_device *dev);
 100};
 101
 102static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
 103{
 104        return container_of(drv, struct xenbus_driver, driver);
 105}
 106
 107int __must_check __xenbus_register_frontend(struct xenbus_driver *drv,
 108                                            struct module *owner,
 109                                            const char *mod_name);
 110
 111static inline int __must_check
 112xenbus_register_frontend(struct xenbus_driver *drv)
 113{
 114        WARN_ON(drv->owner != THIS_MODULE);
 115        return __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME);
 116}
 117
 118int __must_check __xenbus_register_backend(struct xenbus_driver *drv,
 119                                           struct module *owner,
 120                                           const char *mod_name);
 121static inline int __must_check
 122xenbus_register_backend(struct xenbus_driver *drv)
 123{
 124        WARN_ON(drv->owner != THIS_MODULE);
 125        return __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME);
 126}
 127
 128void xenbus_unregister_driver(struct xenbus_driver *drv);
 129
 130struct xenbus_transaction
 131{
 132        u32 id;
 133};
 134
 135/* Nil transaction ID. */
 136#define XBT_NIL ((struct xenbus_transaction) { 0 })
 137
 138int __init xenbus_dev_init(void);
 139
 140char **xenbus_directory(struct xenbus_transaction t,
 141                        const char *dir, const char *node, unsigned int *num);
 142void *xenbus_read(struct xenbus_transaction t,
 143                  const char *dir, const char *node, unsigned int *len);
 144int xenbus_write(struct xenbus_transaction t,
 145                 const char *dir, const char *node, const char *string);
 146int xenbus_mkdir(struct xenbus_transaction t,
 147                 const char *dir, const char *node);
 148int xenbus_exists(struct xenbus_transaction t,
 149                  const char *dir, const char *node);
 150int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
 151int xenbus_transaction_start(struct xenbus_transaction *t);
 152int xenbus_transaction_end(struct xenbus_transaction t, int abort);
 153
 154/* Single read and scanf: returns -errno or num scanned if > 0. */
 155int xenbus_scanf(struct xenbus_transaction t,
 156                 const char *dir, const char *node, const char *fmt, ...)
 157        __attribute__((format(scanf, 4, 5)));
 158
 159/* Single printf and write: returns -errno or 0. */
 160int xenbus_printf(struct xenbus_transaction t,
 161                  const char *dir, const char *node, const char *fmt, ...)
 162        __attribute__((format(printf, 4, 5)));
 163
 164/* Generic read function: NULL-terminated triples of name,
 165 * sprintf-style type string, and pointer. Returns 0 or errno.*/
 166int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
 167
 168/* notifer routines for when the xenstore comes up */
 169extern int xenstored_ready;
 170int register_xenstore_notifier(struct notifier_block *nb);
 171void unregister_xenstore_notifier(struct notifier_block *nb);
 172
 173int register_xenbus_watch(struct xenbus_watch *watch);
 174void unregister_xenbus_watch(struct xenbus_watch *watch);
 175void xs_suspend(void);
 176void xs_resume(void);
 177void xs_suspend_cancel(void);
 178
 179/* Used by xenbus_dev to borrow kernel's store connection. */
 180void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg);
 181
 182struct work_struct;
 183
 184/* Prepare for domain suspend: then resume or cancel the suspend. */
 185void xenbus_suspend(void);
 186void xenbus_resume(void);
 187void xenbus_probe(struct work_struct *);
 188void xenbus_suspend_cancel(void);
 189
 190#define XENBUS_IS_ERR_READ(str) ({                      \
 191        if (!IS_ERR(str) && strlen(str) == 0) {         \
 192                kfree(str);                             \
 193                str = ERR_PTR(-ERANGE);                 \
 194        }                                               \
 195        IS_ERR(str);                                    \
 196})
 197
 198#define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
 199
 200int xenbus_watch_path(struct xenbus_device *dev, const char *path,
 201                      struct xenbus_watch *watch,
 202                      void (*callback)(struct xenbus_watch *,
 203                                       const char **, unsigned int));
 204int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
 205                         void (*callback)(struct xenbus_watch *,
 206                                          const char **, unsigned int),
 207                         const char *pathfmt, ...)
 208        __attribute__ ((format (printf, 4, 5)));
 209
 210int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
 211int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn);
 212int xenbus_map_ring_valloc(struct xenbus_device *dev,
 213                           int gnt_ref, void **vaddr);
 214int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
 215                           grant_handle_t *handle, void *vaddr);
 216
 217int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
 218int xenbus_unmap_ring(struct xenbus_device *dev,
 219                      grant_handle_t handle, void *vaddr);
 220
 221int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
 222int xenbus_bind_evtchn(struct xenbus_device *dev, int remote_port, int *port);
 223int xenbus_free_evtchn(struct xenbus_device *dev, int port);
 224
 225enum xenbus_state xenbus_read_driver_state(const char *path);
 226
 227void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);
 228void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...);
 229
 230const char *xenbus_strstate(enum xenbus_state state);
 231int xenbus_dev_is_online(struct xenbus_device *dev);
 232int xenbus_frontend_closed(struct xenbus_device *dev);
 233
 234#endif /* _XEN_XENBUS_H */
 235