[linux-2.6-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/fs.h>
#include <linux/completion.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/semaphore.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>
#include <xen/interface/event_channel.h>

#define XENBUS_MAX_RING_GRANT_ORDER 4
#define XENBUS_MAX_RING_GRANTS      (1U << XENBUS_MAX_RING_GRANT_ORDER)
#define INVALID_GRANT_HANDLE       (~0U)

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

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

	unsigned int nr_pending;

	/*
	 * Called just before enqueing new event while a spinlock is held.
	 * The event will be discarded if this callback returns false.
	 */
	bool (*will_handle)(struct xenbus_watch *,
			      const char *path, const char *token);

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


/* 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;
	struct semaphore reclaim_sem;
};

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 char *name;       /* defaults to ids[0].devicetype */
	const struct xenbus_device_id *ids;
	bool allow_rebind; /* avoid setting xenstore closed during remove */
	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);
	void (*reclaim_memory)(struct xenbus_device *dev);
};

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 *drv,
					    struct module *owner,
					    const char *mod_name);
int __must_check __xenbus_register_backend(struct xenbus_driver *drv,
					   struct module *owner,
					   const char *mod_name);

#define xenbus_register_frontend(drv) \
	__xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME)
#define xenbus_register_backend(drv) \
	__xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME)

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, ...);

/* Read an (optional) unsigned value. */
unsigned int xenbus_read_unsigned(const char *dir, const char *node,
				  unsigned int default_val);

/* 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);

struct work_struct;

void xenbus_probe(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,
		      bool (*will_handle)(struct xenbus_watch *,
					  const char *, const char *),
		      void (*callback)(struct xenbus_watch *,
				       const char *, const char *));
__printf(5, 6)
int xenbus_watch_pathfmt(struct xenbus_device *dev, struct xenbus_watch *watch,
			 bool (*will_handle)(struct xenbus_watch *,
					     const char *, const char *),
			 void (*callback)(struct xenbus_watch *,
					  const char *, const char *),
			 const char *pathfmt, ...);

int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
int xenbus_grant_ring(struct xenbus_device *dev, void *vaddr,
		      unsigned int nr_pages, grant_ref_t *grefs);
int xenbus_map_ring_valloc(struct xenbus_device *dev, grant_ref_t *gnt_refs,
			   unsigned int nr_grefs, void **vaddr);

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

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

extern const struct file_operations xen_xenbus_fops;
extern struct xenstore_domain_interface *xen_store_interface;
extern int xen_store_evtchn;

#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>
332f791d	41	#include <linux/fs.h>
4bac07c9 JF	42	#include <linux/completion.h>
4bac07c9 JF	43	#include <linux/init.h>
5a0e3ad6	44	#include <linux/slab.h>
2f69a110	45	#include <linux/semaphore.h>
4bac07c9 JF	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>
0102e4ef	50	#include <xen/interface/event_channel.h>
4bac07c9	51
9cce2914 JG	52	#define XENBUS_MAX_RING_GRANT_ORDER 4
9cce2914 JG	53	#define XENBUS_MAX_RING_GRANTS (1U << XENBUS_MAX_RING_GRANT_ORDER)
ccc9d90a WL	54	#define INVALID_GRANT_HANDLE (~0U)
ccc9d90a WL	55
4bac07c9 JF	56	/* Register callback to watch this node. */
	57	struct xenbus_watch
	58	{
	59	struct list_head list;
	60
	61	/* Path being watched. */
	62	const char *node;
	63
3dc86ca6 SP	64	unsigned int nr_pending;
3dc86ca6 SP	65
fed1755b SP	66	/*
	67	* Called just before enqueing new event while a spinlock is held.
	68	* The event will be discarded if this callback returns false.
	69	*/
	70	bool (will_handle)(struct xenbus_watch ,
	71	const char path, const char token);
	72
4bac07c9 JF	73	/* Callback (executed in a process context with no locks held). */
4bac07c9 JF	74	void (callback)(struct xenbus_watch ,
5584ea25	75	const char path, const char token);
4bac07c9 JF	76	};
	77
	78
	79	/* A xenbus device. */
	80	struct xenbus_device {
	81	const char *devicetype;
	82	const char *nodename;
	83	const char *otherend;
	84	int otherend_id;
	85	struct xenbus_watch otherend_watch;
	86	struct device dev;
	87	enum xenbus_state state;
	88	struct completion down;
2abb2746	89	struct work_struct work;
2f69a110	90	struct semaphore reclaim_sem;
4bac07c9 JF	91	};
	92
	93	static inline struct xenbus_device to_xenbus_device(struct device dev)
	94	{
	95	return container_of(dev, struct xenbus_device, dev);
	96	}
	97
	98	struct xenbus_device_id
	99	{
	100	/* .../device/<device_type>/<identifier> */
	101	char devicetype[32]; /* General class of device. */
	102	};
	103
	104	/* A xenbus driver. */
	105	struct xenbus_driver {
95afae48	106	const char name; / defaults to ids[0].devicetype */
4bac07c9	107	const struct xenbus_device_id *ids;
672b7763	108	bool allow_rebind; /* avoid setting xenstore closed during remove */
4bac07c9 JF	109	int (probe)(struct xenbus_device dev,
	110	const struct xenbus_device_id *id);
	111	void (otherend_changed)(struct xenbus_device dev,
	112	enum xenbus_state backend_state);
	113	int (remove)(struct xenbus_device dev);
c7853aea	114	int (suspend)(struct xenbus_device dev);
4bac07c9	115	int (resume)(struct xenbus_device dev);
df660251	116	int (uevent)(struct xenbus_device , struct kobj_uevent_env *);
4bac07c9 JF	117	struct device_driver driver;
4bac07c9 JF	118	int (read_otherend_details)(struct xenbus_device dev);
1d78d705	119	int (is_ready)(struct xenbus_device dev);
8a105678	120	void (reclaim_memory)(struct xenbus_device dev);
4bac07c9 JF	121	};
4bac07c9 JF	122
73db144b	123	static inline struct xenbus_driver to_xenbus_driver(struct device_driver drv)
4bac07c9	124	{
73db144b	125	return container_of(drv, struct xenbus_driver, driver);
4bac07c9 JF	126	}
4bac07c9 JF	127
95afae48 DV	128	int __must_check __xenbus_register_frontend(struct xenbus_driver *drv,
	129	struct module *owner,
	130	const char *mod_name);
	131	int __must_check __xenbus_register_backend(struct xenbus_driver *drv,
	132	struct module *owner,
	133	const char *mod_name);
	134
	135	#define xenbus_register_frontend(drv) \
604b91fe	136	__xenbus_register_frontend(drv, THIS_MODULE, KBUILD_MODNAME)
95afae48	137	#define xenbus_register_backend(drv) \
604b91fe	138	__xenbus_register_backend(drv, THIS_MODULE, KBUILD_MODNAME)
4bac07c9 JF	139
	140	void xenbus_unregister_driver(struct xenbus_driver *drv);
	141
	142	struct xenbus_transaction
	143	{
	144	u32 id;
	145	};
	146
	147	/* Nil transaction ID. */
	148	#define XBT_NIL ((struct xenbus_transaction) { 0 })
	149
4bac07c9 JF	150	char **xenbus_directory(struct xenbus_transaction t,
	151	const char dir, const char node, unsigned int *num);
	152	void *xenbus_read(struct xenbus_transaction t,
	153	const char dir, const char node, unsigned int *len);
	154	int xenbus_write(struct xenbus_transaction t,
	155	const char dir, const char node, const char *string);
	156	int xenbus_mkdir(struct xenbus_transaction t,
	157	const char dir, const char node);
	158	int xenbus_exists(struct xenbus_transaction t,
	159	const char dir, const char node);
	160	int xenbus_rm(struct xenbus_transaction t, const char dir, const char node);
	161	int xenbus_transaction_start(struct xenbus_transaction *t);
	162	int xenbus_transaction_end(struct xenbus_transaction t, int abort);
	163
	164	/* Single read and scanf: returns -errno or num scanned if > 0. */
6061d949	165	__scanf(4, 5)
4bac07c9	166	int xenbus_scanf(struct xenbus_transaction t,
6061d949	167	const char dir, const char node, const char *fmt, ...);
4bac07c9	168
9c53a179 JG	169	/* Read an (optional) unsigned value. */
	170	unsigned int xenbus_read_unsigned(const char dir, const char node,
	171	unsigned int default_val);
	172
4bac07c9	173	/* Single printf and write: returns -errno or 0. */
b9075fa9	174	__printf(4, 5)
4bac07c9	175	int xenbus_printf(struct xenbus_transaction t,
b9075fa9	176	const char dir, const char node, const char *fmt, ...);
4bac07c9 JF	177
	178	/* Generic read function: NULL-terminated triples of name,
	179	* sprintf-style type string, and pointer. Returns 0 or errno.*/
	180	int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
	181
	182	/* notifer routines for when the xenstore comes up */
	183	extern int xenstored_ready;
	184	int register_xenstore_notifier(struct notifier_block *nb);
	185	void unregister_xenstore_notifier(struct notifier_block *nb);
	186
	187	int register_xenbus_watch(struct xenbus_watch *watch);
	188	void unregister_xenbus_watch(struct xenbus_watch *watch);
	189	void xs_suspend(void);
	190	void xs_resume(void);
	191	void xs_suspend_cancel(void);
	192
4bac07c9 JF	193	struct work_struct;
4bac07c9 JF	194
3499ba81	195	void xenbus_probe(void);
4bac07c9 JF	196
	197	#define XENBUS_IS_ERR_READ(str) ({ \
	198	if (!IS_ERR(str) && strlen(str) == 0) { \
	199	kfree(str); \
	200	str = ERR_PTR(-ERANGE); \
	201	} \
	202	IS_ERR(str); \
	203	})
	204
	205	#define XENBUS_EXIST_ERR(err) ((err) == -ENOENT \|\| (err) == -ERANGE)
	206
	207	int xenbus_watch_path(struct xenbus_device dev, const char path,
	208	struct xenbus_watch *watch,
2e85d32b SP	209	bool (will_handle)(struct xenbus_watch ,
2e85d32b SP	210	const char , const char ),
4bac07c9	211	void (callback)(struct xenbus_watch ,
5584ea25	212	const char , const char ));
2e85d32b	213	__printf(5, 6)
4bac07c9	214	int xenbus_watch_pathfmt(struct xenbus_device dev, struct xenbus_watch watch,
2e85d32b SP	215	bool (will_handle)(struct xenbus_watch ,
2e85d32b SP	216	const char , const char ),
4bac07c9	217	void (callback)(struct xenbus_watch ,
5584ea25	218	const char , const char ),
b9075fa9	219	const char *pathfmt, ...);
4bac07c9 JF	220
4bac07c9 JF	221	int xenbus_switch_state(struct xenbus_device *dev, enum xenbus_state new_state);
ccc9d90a WL	222	int xenbus_grant_ring(struct xenbus_device dev, void vaddr,
	223	unsigned int nr_pages, grant_ref_t *grefs);
	224	int xenbus_map_ring_valloc(struct xenbus_device dev, grant_ref_t gnt_refs,
	225	unsigned int nr_grefs, void **vaddr);
4bac07c9 JF	226
4bac07c9 JF	227	int xenbus_unmap_ring_vfree(struct xenbus_device dev, void vaddr);
4bac07c9	228
0102e4ef YY	229	int xenbus_alloc_evtchn(struct xenbus_device dev, evtchn_port_t port);
0102e4ef YY	230	int xenbus_free_evtchn(struct xenbus_device *dev, evtchn_port_t port);
4bac07c9 JF	231
	232	enum xenbus_state xenbus_read_driver_state(const char *path);
	233
b9075fa9	234	__printf(3, 4)
4bac07c9	235	void xenbus_dev_error(struct xenbus_device dev, int err, const char fmt, ...);
b9075fa9	236	__printf(3, 4)
4bac07c9 JF	237	void xenbus_dev_fatal(struct xenbus_device dev, int err, const char fmt, ...);
	238
	239	const char *xenbus_strstate(enum xenbus_state state);
	240	int xenbus_dev_is_online(struct xenbus_device *dev);
	241	int xenbus_frontend_closed(struct xenbus_device *dev);
	242
332f791d JG	243	extern const struct file_operations xen_xenbus_fops;
	244	extern struct xenstore_domain_interface *xen_store_interface;
	245	extern int xen_store_evtchn;
	246
4bac07c9	247	#endif /* _XEN_XENBUS_H */