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/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. */
  55struct 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. */
  69struct 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};
  80
  81static inline struct xenbus_device *to_xenbus_device(struct device *dev)
  82{
  83        return container_of(dev, struct xenbus_device, dev);
  84}
  85
  86struct xenbus_device_id
  87{
  88        /* .../device/<device_type>/<identifier> */
  89        char devicetype[32];    /* General class of device. */
  90};
  91
  92/* A xenbus driver. */
  93struct xenbus_driver {
  94        const char *name;       /* defaults to ids[0].devicetype */
  95        const struct xenbus_device_id *ids;
  96        int (*probe)(struct xenbus_device *dev,
  97                     const struct xenbus_device_id *id);
  98        void (*otherend_changed)(struct xenbus_device *dev,
  99                                 enum xenbus_state backend_state);
 100        int (*remove)(struct xenbus_device *dev);
 101        int (*suspend)(struct xenbus_device *dev);
 102        int (*resume)(struct xenbus_device *dev);
 103        int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *);
 104        struct device_driver driver;
 105        int (*read_otherend_details)(struct xenbus_device *dev);
 106        int (*is_ready)(struct xenbus_device *dev);
 107};
 108
 109static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
 110{
 111        return container_of(drv, struct xenbus_driver, driver);
 112}
 113
 114int __must_check __xenbus_register_frontend(struct xenbus_driver *drv,
 115                                            struct module *owner,
 116                                            const char *mod_name);
 117int __must_check __xenbus_register_backend(struct xenbus_driver *drv,
 118                                           struct module *owner,
 119                                           const char *mod_name);
 120
 121#define xenbus_register_frontend(drv) \
 122        __xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME)
 123#define xenbus_register_backend(drv) \
 124        __xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME)
 125
 126void xenbus_unregister_driver(struct xenbus_driver *drv);
 127
 128struct xenbus_transaction
 129{
 130        u32 id;
 131};
 132
 133/* Nil transaction ID. */
 134#define XBT_NIL ((struct xenbus_transaction) { 0 })
 135
 136char **xenbus_directory(struct xenbus_transaction t,
 137                        const char *dir, const char *node, unsigned int *num);
 138void *xenbus_read(struct xenbus_transaction t,
 139                  const char *dir, const char *node, unsigned int *len);
 140int xenbus_write(struct xenbus_transaction t,
 141                 const char *dir, const char *node, const char *string);
 142int xenbus_mkdir(struct xenbus_transaction t,
 143                 const char *dir, const char *node);
 144int xenbus_exists(struct xenbus_transaction t,
 145                  const char *dir, const char *node);
 146int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
 147int xenbus_transaction_start(struct xenbus_transaction *t);
 148int xenbus_transaction_end(struct xenbus_transaction t, int abort);
 149
 150/* Single read and scanf: returns -errno or num scanned if > 0. */
 151__scanf(4, 5)
 152int xenbus_scanf(struct xenbus_transaction t,
 153                 const char *dir, const char *node, const char *fmt, ...);
 154
 155/* Read an (optional) unsigned value. */
 156unsigned int xenbus_read_unsigned(const char *dir, const char *node,
 157                                  unsigned int default_val);
 158
 159/* Single printf and write: returns -errno or 0. */
 160__printf(4, 5)
 161int xenbus_printf(struct xenbus_transaction t,
 162                  const char *dir, const char *node, const char *fmt, ...);
 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
 179struct work_struct;
 180
 181void xenbus_probe(struct work_struct *);
 182
 183#define XENBUS_IS_ERR_READ(str) ({                      \
 184        if (!IS_ERR(str) && strlen(str) == 0) {         \
 185                kfree(str);                             \
 186                str = ERR_PTR(-ERANGE);                 \
 187        }                                               \
 188        IS_ERR(str);                                    \
 189})
 190
 191#define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)
 192
 193int xenbus_watch_path(struct xenbus_device *dev, const char *path,
 194                      struct xenbus_watch *watch,
 195                      void (*callback)(struct xenbus_watch *,
 196                                       const char *, const char *));
 197__printf(4, 5)
 198int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
 199                         void (*callback)(struct xenbus_watch *,
 200                                          const char *, const char *),
 201                         const char *pathfmt, ...);
 202
 203int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
 204int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
 205                      unsigned int nr_pages, grant_ref_t *grefs);
 206int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
 207                           unsigned int nr_grefs, void **vaddr);
 208int xenbus_map_ring(struct xenbus_device *dev,
 209                    grant_ref_t *gnt_refs, unsigned int nr_grefs,
 210                    grant_handle_t *handles, unsigned long *vaddrs,
 211                    bool *leaked);
 212
 213int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
 214int xenbus_unmap_ring(struct xenbus_device *dev,
 215                      grant_handle_t *handles, unsigned int nr_handles,
 216                      unsigned long *vaddrs);
 217
 218int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
 219int xenbus_free_evtchn(struct xenbus_device *dev, int port);
 220
 221enum xenbus_state xenbus_read_driver_state(const char *path);
 222
 223__printf(3, 4)
 224void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);
 225__printf(3, 4)
 226void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...);
 227
 228const char *xenbus_strstate(enum xenbus_state state);
 229int xenbus_dev_is_online(struct xenbus_device *dev);
 230int xenbus_frontend_closed(struct xenbus_device *dev);
 231
 232extern const struct file_operations xen_xenbus_fops;
 233extern struct xenstore_domain_interface *xen_store_interface;
 234extern int xen_store_evtchn;
 235
 236#endif /* _XEN_XENBUS_H */
 237