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/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. */
  50struct 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. */
  64struct 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
  76static inline struct xenbus_device *to_xenbus_device(struct device *dev)
  77{
  78        return container_of(dev, struct xenbus_device, dev);
  79}
  80
  81struct xenbus_device_id
  82{
  83        /* .../device/<device_type>/<identifier> */
  84        char devicetype[32];    /* General class of device. */
  85};
  86
  87/* A xenbus driver. */
  88struct 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
 104static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
 105{
 106        return container_of(drv, struct xenbus_driver, driver);
 107}
 108
 109int __must_check __xenbus_register_frontend(struct xenbus_driver *drv,
 110                                            struct module *owner,
 111                                            const char *mod_name);
 112int __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
 121void xenbus_unregister_driver(struct xenbus_driver *drv);
 122
 123struct xenbus_transaction
 124{
 125        u32 id;
 126};
 127
 128/* Nil transaction ID. */
 129#define XBT_NIL ((struct xenbus_transaction) { 0 })
 130
 131char **xenbus_directory(struct xenbus_transaction t,
 132                        const char *dir, const char *node, unsigned int *num);
 133void *xenbus_read(struct xenbus_transaction t,
 134                  const char *dir, const char *node, unsigned int *len);
 135int xenbus_write(struct xenbus_transaction t,
 136                 const char *dir, const char *node, const char *string);
 137int xenbus_mkdir(struct xenbus_transaction t,
 138                 const char *dir, const char *node);
 139int xenbus_exists(struct xenbus_transaction t,
 140                  const char *dir, const char *node);
 141int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
 142int xenbus_transaction_start(struct xenbus_transaction *t);
 143int 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)
 147int 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)
 152int 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.*/
 157int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
 158
 159/* notifer routines for when the xenstore comes up */
 160extern int xenstored_ready;
 161int register_xenstore_notifier(struct notifier_block *nb);
 162void unregister_xenstore_notifier(struct notifier_block *nb);
 163
 164int register_xenbus_watch(struct xenbus_watch *watch);
 165void unregister_xenbus_watch(struct xenbus_watch *watch);
 166void xs_suspend(void);
 167void xs_resume(void);
 168void xs_suspend_cancel(void);
 169
 170/* Used by xenbus_dev to borrow kernel's store connection. */
 171void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg);
 172
 173struct work_struct;
 174
 175/* Prepare for domain suspend: then resume or cancel the suspend. */
 176void xenbus_suspend(void);
 177void xenbus_resume(void);
 178void xenbus_probe(struct work_struct *);
 179void 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
 191int 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)
 196int 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
 201int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
 202int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn);
 203int xenbus_map_ring_valloc(struct xenbus_device *dev,
 204                           int gnt_ref, void **vaddr);
 205int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
 206                           grant_handle_t *handle, void *vaddr);
 207
 208int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
 209int xenbus_unmap_ring(struct xenbus_device *dev,
 210                      grant_handle_t handle, void *vaddr);
 211
 212int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
 213int xenbus_free_evtchn(struct xenbus_device *dev, int port);
 214
 215enum xenbus_state xenbus_read_driver_state(const char *path);
 216
 217__printf(3, 4)
 218void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);
 219__printf(3, 4)
 220void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...);
 221
 222const char *xenbus_strstate(enum xenbus_state state);
 223int xenbus_dev_is_online(struct xenbus_device *dev);
 224int xenbus_frontend_closed(struct xenbus_device *dev);
 225
 226#endif /* _XEN_XENBUS_H */
 227