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1/******************************************************************************2 * xenbus.h3 *4 * Talks to Xen Store to figure out what devices we have.5 *6 * Copyright (C) 2005 Rusty Russell, IBM Corporation7 * Copyright (C) 2005 XenSource Ltd.8 *9 * This program is free software; you can redistribute it and/or10 * modify it under the terms of the GNU General Public License version 211 * as published by the Free Software Foundation; or, when distributed12 * separately from the Linux kernel or incorporated into other13 * software packages, subject to the following license:14 *15 * Permission is hereby granted, free of charge, to any person obtaining a copy16 * of this source file (the "Software"), to deal in the Software without17 * 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 to20 * the following conditions:21 *22 * The above copyright notice and this permission notice shall be included in23 * all copies or substantial portions of the Software.24 *25 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR26 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,27 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE28 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER29 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING30 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS31 * IN THE SOFTWARE.32 */33 34#ifndef _XEN_XENBUS_H35#define _XEN_XENBUS_H36 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 453#define XENBUS_MAX_RING_GRANTS (1U << XENBUS_MAX_RING_GRANT_ORDER)54 55/* Register callback to watch this node. */56struct xenbus_watch57{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. */79struct 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 101struct xenbus_device_id102{103 /* .../device/<device_type>/<identifier> */104 char devicetype[32]; /* General class of device. */105};106 107/* A xenbus driver. */108struct 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 129int __must_check __xenbus_register_frontend(struct xenbus_driver *drv,130 struct module *owner,131 const char *mod_name);132int __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 141void xenbus_unregister_driver(struct xenbus_driver *drv);142 143struct xenbus_transaction144{145 u32 id;146};147 148/* Nil transaction ID. */149#define XBT_NIL ((struct xenbus_transaction) { 0 })150 151char **xenbus_directory(struct xenbus_transaction t,152 const char *dir, const char *node, unsigned int *num);153void *xenbus_read(struct xenbus_transaction t,154 const char *dir, const char *node, unsigned int *len);155int xenbus_write(struct xenbus_transaction t,156 const char *dir, const char *node, const char *string);157int xenbus_mkdir(struct xenbus_transaction t,158 const char *dir, const char *node);159int xenbus_exists(struct xenbus_transaction t,160 const char *dir, const char *node);161int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);162int xenbus_transaction_start(struct xenbus_transaction *t);163int xenbus_transaction_end(struct xenbus_transaction t, int abort);164 165/* Single read and scanf: returns -errno or num scanned if > 0. */166__scanf(4, 5)167int xenbus_scanf(struct xenbus_transaction t,168 const char *dir, const char *node, const char *fmt, ...);169 170/* Read an (optional) unsigned value. */171unsigned int xenbus_read_unsigned(const char *dir, const char *node,172 unsigned int default_val);173 174/* Single printf and write: returns -errno or 0. */175__printf(4, 5)176int xenbus_printf(struct xenbus_transaction t,177 const char *dir, const char *node, const char *fmt, ...);178 179/* Generic read function: NULL-terminated triples of name,180 * sprintf-style type string, and pointer. Returns 0 or errno.*/181int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);182 183/* notifer routines for when the xenstore comes up */184extern int xenstored_ready;185int register_xenstore_notifier(struct notifier_block *nb);186void unregister_xenstore_notifier(struct notifier_block *nb);187 188int register_xenbus_watch(struct xenbus_watch *watch);189void unregister_xenbus_watch(struct xenbus_watch *watch);190void xs_suspend(void);191void xs_resume(void);192void xs_suspend_cancel(void);193 194struct work_struct;195 196#define XENBUS_IS_ERR_READ(str) ({ \197 if (!IS_ERR(str) && strlen(str) == 0) { \198 kfree(str); \199 str = ERR_PTR(-ERANGE); \200 } \201 IS_ERR(str); \202})203 204#define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)205 206int xenbus_watch_path(struct xenbus_device *dev, const char *path,207 struct xenbus_watch *watch,208 bool (*will_handle)(struct xenbus_watch *,209 const char *, const char *),210 void (*callback)(struct xenbus_watch *,211 const char *, const char *));212__printf(5, 6)213int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,214 bool (*will_handle)(struct xenbus_watch *,215 const char *, const char *),216 void (*callback)(struct xenbus_watch *,217 const char *, const char *),218 const char *pathfmt, ...);219 220int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);221int xenbus_setup_ring(struct xenbus_device *dev, gfp_t gfp, void **vaddr,222 unsigned int nr_pages, grant_ref_t *grefs);223void xenbus_teardown_ring(void **vaddr, unsigned int nr_pages,224 grant_ref_t *grefs);225int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,226 unsigned int nr_grefs, void **vaddr);227 228int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);229 230int xenbus_alloc_evtchn(struct xenbus_device *dev, evtchn_port_t *port);231int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t port);232 233enum xenbus_state xenbus_read_driver_state(const char *path);234 235__printf(3, 4)236void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);237__printf(3, 4)238void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...);239 240const char *xenbus_strstate(enum xenbus_state state);241int xenbus_dev_is_online(struct xenbus_device *dev);242int xenbus_frontend_closed(struct xenbus_device *dev);243 244extern const struct file_operations xen_xenbus_fops;245extern struct xenstore_domain_interface *xen_store_interface;246extern int xen_store_evtchn;247 248#endif /* _XEN_XENBUS_H */249