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_PAGE_ORDER 4
50#define XENBUS_MAX_RING_PAGES      (1U << XENBUS_MAX_RING_PAGE_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