linux/include/xen/xenbus.h
Jan Beulich 73db144b58 Xen: consolidate and simplify struct xenbus_driver instantiation
The 'name', 'owner', and 'mod_name' members are redundant with the
identically named fields in the 'driver' sub-structure. Rather than
switching each instance to specify these fields explicitly, introduce
a macro to simplify this.

Eliminate further redundancy by allowing the drvname argument to
DEFINE_XENBUS_DRIVER() to be blank (in which case the first entry from
the ID table will be used for .driver.name).

Also eliminate the questionable xenbus_register_{back,front}end()
wrappers - their sole remaining purpose was the checking of the
'owner' field, proper setting of which shouldn't be an issue anymore
when the macro gets used.

v2: Restore DRV_NAME for the driver name in xen-pciback.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2012-01-04 17:01:17 -05:00

223 lines
7.7 KiB
C

/******************************************************************************
* 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;
};
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. */
int xenbus_scanf(struct xenbus_transaction t,
const char *dir, const char *node, const char *fmt, ...)
__attribute__((format(scanf, 4, 5)));
/* 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_bind_evtchn(struct xenbus_device *dev, int remote_port, 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 */