[linux-block.git] / include / xen / xenbus.h

/******************************************************************************
 * xenbus.h
 *
 * Talks to Xen Store to figure out what devices we have.
 *
 * Copyright (C) 2005 Rusty Russell, IBM Corporation
 * Copyright (C) 2005 XenSource Ltd.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version 2
 * as published by the Free Software Foundation; or, when distributed
 * separately from the Linux kernel or incorporated into other
 * software packages, subject to the following license:
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this source file (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy, modify,
 * merge, publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#ifndef _XEN_XENBUS_H
#define _XEN_XENBUS_H

#include <linux/device.h>
#include <linux/notifier.h>
#include <linux/mutex.h>
#include <linux/export.h>
#include <linux/completion.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <xen/interface/xen.h>
#include <xen/interface/grant_table.h>
#include <xen/interface/io/xenbus.h>
#include <xen/interface/io/xs_wire.h>

/* Register callback to watch this node. */
struct xenbus_watch
{
	struct list_head list;

	/* Path being watched. */
	const char *node;

	/* Callback (executed in a process context with no locks held). */
	void (*callback)(struct xenbus_watch *,
			 const char **vec, unsigned int len);
};


/* A xenbus device. */
struct xenbus_device {
	const char *devicetype;
	const char *nodename;
	const char *otherend;
	int otherend_id;
	struct xenbus_watch otherend_watch;
	struct device dev;
	enum xenbus_state state;
	struct completion down;
	struct work_struct work;
};

static inline struct xenbus_device *to_xenbus_device(struct device *dev)
{
	return container_of(dev, struct xenbus_device, dev);
}

struct xenbus_device_id
{
	/* .../device/<device_type>/<identifier> */
	char devicetype[32]; 	/* General class of device. */
};

/* A xenbus driver. */
struct xenbus_driver {
	const struct xenbus_device_id *ids;
	int (*probe)(struct xenbus_device *dev,
		     const struct xenbus_device_id *id);
	void (*otherend_changed)(struct xenbus_device *dev,
				 enum xenbus_state backend_state);
	int (*remove)(struct xenbus_device *dev);
	int (*suspend)(struct xenbus_device *dev);
	int (*resume)(struct xenbus_device *dev);
	int (*uevent)(struct xenbus_device *, struct kobj_uevent_env *);
	struct device_driver driver;
	int (*read_otherend_details)(struct xenbus_device *dev);
	int (*is_ready)(struct xenbus_device *dev);
};

#define DEFINE_XENBUS_DRIVER(var, drvname, methods...)		\
struct xenbus_driver var ## _driver = {				\
	.driver.name = drvname + 0 ?: var ## _ids->devicetype,	\
	.driver.owner = THIS_MODULE,				\
	.ids = var ## _ids, ## methods				\
}

static inline struct xenbus_driver *to_xenbus_driver(struct device_driver *drv)
{
	return container_of(drv, struct xenbus_driver, driver);
}

int __must_check xenbus_register_frontend(struct xenbus_driver *);
int __must_check xenbus_register_backend(struct xenbus_driver *);

void xenbus_unregister_driver(struct xenbus_driver *drv);

struct xenbus_transaction
{
	u32 id;
};

/* Nil transaction ID. */
#define XBT_NIL ((struct xenbus_transaction) { 0 })

char **xenbus_directory(struct xenbus_transaction t,
			const char *dir, const char *node, unsigned int *num);
void *xenbus_read(struct xenbus_transaction t,
		  const char *dir, const char *node, unsigned int *len);
int xenbus_write(struct xenbus_transaction t,
		 const char *dir, const char *node, const char *string);
int xenbus_mkdir(struct xenbus_transaction t,
		 const char *dir, const char *node);
int xenbus_exists(struct xenbus_transaction t,
		  const char *dir, const char *node);
int xenbus_rm(struct xenbus_transaction t, const char *dir, const char *node);
int xenbus_transaction_start(struct xenbus_transaction *t);
int xenbus_transaction_end(struct xenbus_transaction t, int abort);

/* Single read and scanf: returns -errno or num scanned if > 0. */
__scanf(4, 5)
int xenbus_scanf(struct xenbus_transaction t,
		 const char *dir, const char *node, const char *fmt, ...);

/* Single printf and write: returns -errno or 0. */
__printf(4, 5)
int xenbus_printf(struct xenbus_transaction t,
		  const char *dir, const char *node, const char *fmt, ...);

/* Generic read function: NULL-terminated triples of name,
 * sprintf-style type string, and pointer. Returns 0 or errno.*/
int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);

/* notifer routines for when the xenstore comes up */
extern int xenstored_ready;
int register_xenstore_notifier(struct notifier_block *nb);
void unregister_xenstore_notifier(struct notifier_block *nb);

int register_xenbus_watch(struct xenbus_watch *watch);
void unregister_xenbus_watch(struct xenbus_watch *watch);
void xs_suspend(void);
void xs_resume(void);
void xs_suspend_cancel(void);

/* Used by xenbus_dev to borrow kernel's store connection. */
void *xenbus_dev_request_and_reply(struct xsd_sockmsg *msg);

struct work_struct;

/* Prepare for domain suspend: then resume or cancel the suspend. */
void xenbus_suspend(void);
void xenbus_resume(void);
void xenbus_probe(struct work_struct *);
void xenbus_suspend_cancel(void);

#define XENBUS_IS_ERR_READ(str) ({			\
	if (!IS_ERR(str) && strlen(str) == 0) {		\
		kfree(str);				\
		str = ERR_PTR(-ERANGE);			\
	}						\
	IS_ERR(str);					\
})

#define XENBUS_EXIST_ERR(err) ((err) == -ENOENT || (err) == -ERANGE)

int xenbus_watch_path(struct xenbus_device *dev, const char *path,
		      struct xenbus_watch *watch,
		      void (*callback)(struct xenbus_watch *,
				       const char **, unsigned int));
__printf(4, 5)
int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
			 void (*callback)(struct xenbus_watch *,
					  const char **, unsigned int),
			 const char *pathfmt, ...);

int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn);
int xenbus_map_ring_valloc(struct xenbus_device *dev,
			   int gnt_ref, void **vaddr);
int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
			   grant_handle_t *handle, void *vaddr);

int xenbus_unmap_ring_vfree(struct xenbus_device *dev, void *vaddr);
int xenbus_unmap_ring(struct xenbus_device *dev,
		      grant_handle_t handle, void *vaddr);

int xenbus_alloc_evtchn(struct xenbus_device *dev, int *port);
int xenbus_free_evtchn(struct xenbus_device *dev, int port);

enum xenbus_state xenbus_read_driver_state(const char *path);

__printf(3, 4)
void xenbus_dev_error(struct xenbus_device *dev, int err, const char *fmt, ...);
__printf(3, 4)
void xenbus_dev_fatal(struct xenbus_device *dev, int err, const char *fmt, ...);

const char *xenbus_strstate(enum xenbus_state state);
int xenbus_dev_is_online(struct xenbus_device *dev);
int xenbus_frontend_closed(struct xenbus_device *dev);

#endif /* _XEN_XENBUS_H */
Commit	Line	Data
4bac07c9 JF	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>
63c9744b	40	#include <linux/export.h>
4bac07c9 JF	41	#include <linux/completion.h>
4bac07c9 JF	42	#include <linux/init.h>
5a0e3ad6	43	#include <linux/slab.h>
4bac07c9 JF	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. */
	50	struct 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. */
	64	struct 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;
2abb2746	73	struct work_struct work;
4bac07c9 JF	74	};
	75
	76	static inline struct xenbus_device to_xenbus_device(struct device dev)
	77	{
	78	return container_of(dev, struct xenbus_device, dev);
	79	}
	80
	81	struct xenbus_device_id
	82	{
	83	/* .../device/<device_type>/<identifier> */
	84	char devicetype[32]; /* General class of device. */
	85	};
	86
	87	/* A xenbus driver. */
	88	struct xenbus_driver {
4bac07c9 JF	89	const struct xenbus_device_id *ids;
	90	int (probe)(struct xenbus_device dev,
	91	const struct xenbus_device_id *id);
	92	void (otherend_changed)(struct xenbus_device dev,
	93	enum xenbus_state backend_state);
	94	int (remove)(struct xenbus_device dev);
c7853aea	95	int (suspend)(struct xenbus_device dev);
4bac07c9	96	int (resume)(struct xenbus_device dev);
df660251	97	int (uevent)(struct xenbus_device , struct kobj_uevent_env *);
4bac07c9 JF	98	struct device_driver driver;
4bac07c9 JF	99	int (read_otherend_details)(struct xenbus_device dev);
1d78d705	100	int (is_ready)(struct xenbus_device dev);
4bac07c9 JF	101	};
4bac07c9 JF	102
73db144b JB	103	#define DEFINE_XENBUS_DRIVER(var, drvname, methods...) \
	104	struct xenbus_driver var ## _driver = { \
	105	.driver.name = drvname + 0 ?: var ## _ids->devicetype, \
	106	.driver.owner = THIS_MODULE, \
	107	.ids = var ## _ids, ## methods \
4bac07c9 JF	108	}
4bac07c9 JF	109
73db144b	110	static inline struct xenbus_driver to_xenbus_driver(struct device_driver drv)
4bac07c9	111	{
73db144b	112	return container_of(drv, struct xenbus_driver, driver);
4bac07c9 JF	113	}
4bac07c9 JF	114
73db144b JB	115	int __must_check xenbus_register_frontend(struct xenbus_driver *);
73db144b JB	116	int __must_check xenbus_register_backend(struct xenbus_driver *);
4bac07c9 JF	117
	118	void xenbus_unregister_driver(struct xenbus_driver *drv);
	119
	120	struct xenbus_transaction
	121	{
	122	u32 id;
	123	};
	124
	125	/* Nil transaction ID. */
	126	#define XBT_NIL ((struct xenbus_transaction) { 0 })
	127
4bac07c9 JF	128	char **xenbus_directory(struct xenbus_transaction t,
	129	const char dir, const char node, unsigned int *num);
	130	void *xenbus_read(struct xenbus_transaction t,
	131	const char dir, const char node, unsigned int *len);
	132	int xenbus_write(struct xenbus_transaction t,
	133	const char dir, const char node, const char *string);
	134	int xenbus_mkdir(struct xenbus_transaction t,
	135	const char dir, const char node);
	136	int xenbus_exists(struct xenbus_transaction t,
	137	const char dir, const char node);
	138	int xenbus_rm(struct xenbus_transaction t, const char dir, const char node);
	139	int xenbus_transaction_start(struct xenbus_transaction *t);
	140	int xenbus_transaction_end(struct xenbus_transaction t, int abort);
	141
	142	/* Single read and scanf: returns -errno or num scanned if > 0. */
6061d949	143	__scanf(4, 5)
4bac07c9	144	int xenbus_scanf(struct xenbus_transaction t,
6061d949	145	const char dir, const char node, const char *fmt, ...);
4bac07c9 JF	146
4bac07c9 JF	147	/* Single printf and write: returns -errno or 0. */
b9075fa9	148	__printf(4, 5)
4bac07c9	149	int xenbus_printf(struct xenbus_transaction t,
b9075fa9	150	const char dir, const char node, const char *fmt, ...);
4bac07c9 JF	151
	152	/* Generic read function: NULL-terminated triples of name,
	153	* sprintf-style type string, and pointer. Returns 0 or errno.*/
	154	int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
	155
	156	/* notifer routines for when the xenstore comes up */
	157	extern int xenstored_ready;
	158	int register_xenstore_notifier(struct notifier_block *nb);
	159	void unregister_xenstore_notifier(struct notifier_block *nb);
	160
	161	int register_xenbus_watch(struct xenbus_watch *watch);
	162	void unregister_xenbus_watch(struct xenbus_watch *watch);
	163	void xs_suspend(void);
	164	void xs_resume(void);
	165	void xs_suspend_cancel(void);
	166
	167	/* Used by xenbus_dev to borrow kernel's store connection. */
	168	void xenbus_dev_request_and_reply(struct xsd_sockmsg msg);
	169
	170	struct work_struct;
	171
	172	/* Prepare for domain suspend: then resume or cancel the suspend. */
	173	void xenbus_suspend(void);
	174	void xenbus_resume(void);
	175	void xenbus_probe(struct work_struct *);
	176	void xenbus_suspend_cancel(void);
	177
	178	#define XENBUS_IS_ERR_READ(str) ({ \
	179	if (!IS_ERR(str) && strlen(str) == 0) { \
	180	kfree(str); \
	181	str = ERR_PTR(-ERANGE); \
	182	} \
	183	IS_ERR(str); \
	184	})
	185
	186	#define XENBUS_EXIST_ERR(err) ((err) == -ENOENT \|\| (err) == -ERANGE)
	187
	188	int xenbus_watch_path(struct xenbus_device dev, const char path,
	189	struct xenbus_watch *watch,
	190	void (callback)(struct xenbus_watch ,
	191	const char **, unsigned int));
b9075fa9	192	__printf(4, 5)
4bac07c9 JF	193	int xenbus_watch_pathfmt(struct xenbus_device dev, struct xenbus_watch watch,
	194	void (callback)(struct xenbus_watch ,
	195	const char **, unsigned int),
b9075fa9	196	const char *pathfmt, ...);
4bac07c9 JF	197
	198	int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
	199	int xenbus_grant_ring(struct xenbus_device *dev, unsigned long ring_mfn);
	200	int xenbus_map_ring_valloc(struct xenbus_device *dev,
	201	int gnt_ref, void **vaddr);
	202	int xenbus_map_ring(struct xenbus_device *dev, int gnt_ref,
	203	grant_handle_t handle, void vaddr);
	204
	205	int xenbus_unmap_ring_vfree(struct xenbus_device dev, void vaddr);
	206	int xenbus_unmap_ring(struct xenbus_device *dev,
	207	grant_handle_t handle, void *vaddr);
	208
	209	int xenbus_alloc_evtchn(struct xenbus_device dev, int port);
4bac07c9 JF	210	int xenbus_free_evtchn(struct xenbus_device *dev, int port);
	211
	212	enum xenbus_state xenbus_read_driver_state(const char *path);
	213
b9075fa9	214	__printf(3, 4)
4bac07c9	215	void xenbus_dev_error(struct xenbus_device dev, int err, const char fmt, ...);
b9075fa9	216	__printf(3, 4)
4bac07c9 JF	217	void xenbus_dev_fatal(struct xenbus_device dev, int err, const char fmt, ...);
	218
	219	const char *xenbus_strstate(enum xenbus_state state);
	220	int xenbus_dev_is_online(struct xenbus_device *dev);
	221	int xenbus_frontend_closed(struct xenbus_device *dev);
	222
	223	#endif /* _XEN_XENBUS_H */