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#define XENBUS_MAX_RING_GRANT_ORDER 4
  50#define XENBUS_MAX_RING_GRANTS      (1U << XENBUS_MAX_RING_GRANT_ORDER)
  51#define INVALID_GRANT_HANDLE       (~0U)
  52
  53/* Register callback to watch this node. */
  54struct xenbus_watch
  55{
  56        struct list_head list;
  57
  58        /* Path being watched. */
  59        const char *node;
  60
  61        /* Callback (executed in a process context with no locks held). */
  62        void (*callback)(struct xenbus_watch *,
  63                         const char **vec, unsigned int len);
  64};
  65
  66
  67/* A xenbus device. */
  68struct xenbus_device {
  69        const char *devicetype;
  70        const char *nodename;
  71        const char *otherend;
  72        int otherend_id;
  73        struct xenbus_watch otherend_watch;
  74        struct device dev;
  75        enum xenbus_state state;
  76        struct completion down;
  77        struct work_struct work;
  78};
  79
  80static inline struct xenbus_device *to_xenbus_device(struct device *dev)
  81{
  82        return container_of(dev, struct xenbus_device, dev);
  83}
  84
  85struct xenbus_device_id
  86{
  87        /* .../device/<device_type>/<identifier> */
  88        char devicetype[32];    /* General class of device. */
  89};
  90
  91/* A xenbus driver. */
  92struct xenbus_driver {
  93        const char *name;       /* defaults to ids[0].devicetype */
  94        const struct xenbus_device_id *ids;
  95        int (*probe)(struct xenbus_device *dev,
  96                     const struct xenbus_device_id *id);
  97        void (*otherend_changed)(struct xenbus_device *dev,
  98                                 enum xenbus_state backend_state);
  99        int (*remove)(struct xenbus_device *dev);
 100        int (*suspend)(struct xenbus_device *dev);
 101        int (*resume)(struct xenbus_device *dev);
 102        int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *);
 103        struct device_driver driver;
 104        int (*read_otherend_details)(struct xenbus_device *dev);
 105        int (*is_ready)(struct xenbus_device *dev);
 106};
 107
 108static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
 109{
 110        return container_of(drv, struct xenbus_driver, driver);
 111}
 112
 113int __must_check __xenbus_register_frontend(struct xenbus_driver *drv,
 114                                            struct module *owner,
 115                                            const char *mod_name);
 116int __must_check __xenbus_register_backend(struct xenbus_driver *drv,
 117                                           struct module *owner,
 118                                           const char *mod_name);
 119
 120#define xenbus_register_frontend(drv) \
 121        __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME)
 122#define xenbus_register_backend(drv) \
 123        __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME)
 124
 125void xenbus_unregister_driver(struct xenbus_driver *drv);
 126
 127struct xenbus_transaction
 128{
 129        u32 id;
 130};
 131
 132/* Nil transaction ID. */
 133#define XBT_NIL ((struct xenbus_transaction) { 0 })
 134
 135char **xenbus_directory(struct xenbus_transaction t,
 136                        const char *dir, const char *node, unsigned int *num);
 137void *xenbus_read(struct xenbus_transaction t,
 138                  const char *dir, const char *node, unsigned int *len);
 139int xenbus_write(struct xenbus_transaction t,
 140                 const char *dir, const char *node, const char *string);
 141int xenbus_mkdir(struct xenbus_transaction t,
 142                 const char *dir, const char *node);
 143int xenbus_exists(struct xenbus_transaction t,
 144                  const char *dir, const char *node);
 145int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
 146int xenbus_transaction_start(struct xenbus_transaction *t);
 147int xenbus_transaction_end(struct xenbus_transaction t, int abort);
 148
 149/* Single read and scanf: returns -errno or num scanned if > 0. */
 150__scanf(4, 5)
 151int xenbus_scanf(struct xenbus_transaction t,
 152                 const char *dir, const char *node, const char *fmt, ...);
 153
 154/* Single printf and write: returns -errno or 0. */
 155__printf(4, 5)
 156int xenbus_printf(struct xenbus_transaction t,
 157                  const char *dir, const char *node, const char *fmt, ...);
 158
 159/* Generic read function: NULL-terminated triples of name,
 160 * sprintf-style type string, and pointer. Returns 0 or errno.*/
 161int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
 162
 163/* notifer routines for when the xenstore comes up */
 164extern int xenstored_ready;
 165int register_xenstore_notifier(struct notifier_block *nb);
 166void unregister_xenstore_notifier(struct notifier_block *nb);
 167
 168int register_xenbus_watch(struct xenbus_watch *watch);
 169void unregister_xenbus_watch(struct xenbus_watch *watch);
 170void xs_suspend(void);
 171void xs_resume(void);
 172void xs_suspend_cancel(void);
 173
 174/* Used by xenbus_dev to borrow kernel's store connection. */
 175void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg);
 176
 177struct work_struct;
 178
 179/* Prepare for domain suspend: then resume or cancel the suspend. */
 180void xenbus_suspend(void);
 181void xenbus_resume(void);
 182void xenbus_probe(struct work_struct *);
 183void xenbus_suspend_cancel(void);
 184
 185#define XENBUS_IS_ERR_READ(str) ({                      \
 186        if (!IS_ERR(str) && strlen(str) == 0) {         \
 187                kfree(str);                             \
 188                str = ERR_PTR(-ERANGE);                 \
 189        }                                               \
 190        IS_ERR(str);                                    \
 191})
 192
 193#define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
 194
 195int xenbus_watch_path(struct xenbus_device *dev, const char *path,
 196                      struct xenbus_watch *watch,
 197                      void (*callback)(struct xenbus_watch *,
 198                                       const char **, unsigned int));
 199__printf(4, 5)
 200int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
 201                         void (*callback)(struct xenbus_watch *,
 202                                          const char **, unsigned int),
 203                         const char *pathfmt, ...);
 204
 205int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
 206int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
 207                      unsigned int nr_pages, grant_ref_t *grefs);
 208int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
 209                           unsigned int nr_grefs, void **vaddr);
 210int xenbus_map_ring(struct xenbus_device *dev,
 211                    grant_ref_t *gnt_refs, unsigned int nr_grefs,
 212                    grant_handle_t *handles, unsigned long *vaddrs,
 213                    bool *leaked);
 214
 215int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
 216int xenbus_unmap_ring(struct xenbus_device *dev,
 217                      grant_handle_t *handles, unsigned int nr_handles,
 218                      unsigned long *vaddrs);
 219
 220int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
 221int xenbus_free_evtchn(struct xenbus_device *dev, int port);
 222
 223enum xenbus_state xenbus_read_driver_state(const char *path);
 224
 225__printf(3, 4)
 226void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);
 227__printf(3, 4)
 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