linux/drivers/xen/xenbus/xenbus.h
Greg Kroah-Hartman d69d804845 driver core: have match() callback in struct bus_type take a const *
In the match() callback, the struct device_driver * should not be
changed, so change the function callback to be a const *.  This is one
step of many towards making the driver core safe to have struct
device_driver in read-only memory.

Because the match() callback is in all busses, all busses are modified
to handle this properly.  This does entail switching some container_of()
calls to container_of_const() to properly handle the constant *.

For some busses, like PCI and USB and HV, the const * is cast away in
the match callback as those busses do want to modify those structures at
this point in time (they have a local lock in the driver structure.)
That will have to be changed in the future if they wish to have their
struct device * in read-only-memory.

Cc: Rafael J. Wysocki <rafael@kernel.org>
Reviewed-by: Alex Elder <elder@kernel.org>
Acked-by: Sumit Garg <sumit.garg@linaro.org>
Link: https://lore.kernel.org/r/2024070136-wrongdoer-busily-01e8@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-07-03 15:16:54 +02:00

140 lines
4.2 KiB
C

/*
* Private include for xenbus communications.
*
* 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 _XENBUS_XENBUS_H
#define _XENBUS_XENBUS_H
#include <linux/mutex.h>
#include <linux/uio.h>
#include <xen/xenbus.h>
#define XEN_BUS_ID_SIZE 20
struct xen_bus_type {
char *root;
unsigned int levels;
int (*get_bus_id)(char bus_id[XEN_BUS_ID_SIZE], const char *nodename);
int (*probe)(struct xen_bus_type *bus, const char *type,
const char *dir);
bool (*otherend_will_handle)(struct xenbus_watch *watch,
const char *path, const char *token);
void (*otherend_changed)(struct xenbus_watch *watch, const char *path,
const char *token);
struct bus_type bus;
};
enum xenstore_init {
XS_UNKNOWN,
XS_PV,
XS_HVM,
XS_LOCAL,
};
struct xs_watch_event {
struct list_head list;
unsigned int len;
struct xenbus_watch *handle;
const char *path;
const char *token;
char body[];
};
enum xb_req_state {
xb_req_state_queued,
xb_req_state_wait_reply,
xb_req_state_got_reply,
xb_req_state_aborted
};
struct xb_req_data {
struct list_head list;
wait_queue_head_t wq;
struct xsd_sockmsg msg;
uint32_t caller_req_id;
enum xsd_sockmsg_type type;
char *body;
const struct kvec *vec;
int num_vecs;
int err;
enum xb_req_state state;
bool user_req;
void (*cb)(struct xb_req_data *);
void *par;
};
extern enum xenstore_init xen_store_domain_type;
extern const struct attribute_group *xenbus_dev_groups[];
extern struct mutex xs_response_mutex;
extern struct list_head xs_reply_list;
extern struct list_head xb_write_list;
extern wait_queue_head_t xb_waitq;
extern struct mutex xb_write_mutex;
int xs_init(void);
int xb_init_comms(void);
void xb_deinit_comms(void);
int xs_watch_msg(struct xs_watch_event *event);
void xs_request_exit(struct xb_req_data *req);
int xenbus_match(struct device *_dev, const struct device_driver *_drv);
int xenbus_dev_probe(struct device *_dev);
void xenbus_dev_remove(struct device *_dev);
int xenbus_register_driver_common(struct xenbus_driver *drv,
struct xen_bus_type *bus,
struct module *owner,
const char *mod_name);
int xenbus_probe_node(struct xen_bus_type *bus,
const char *type,
const char *nodename);
int xenbus_probe_devices(struct xen_bus_type *bus);
void xenbus_dev_changed(const char *node, struct xen_bus_type *bus);
int xenbus_dev_suspend(struct device *dev);
int xenbus_dev_resume(struct device *dev);
int xenbus_dev_cancel(struct device *dev);
void xenbus_otherend_changed(struct xenbus_watch *watch,
const char *path, const char *token,
int ignore_on_shutdown);
int xenbus_read_otherend_details(struct xenbus_device *xendev,
char *id_node, char *path_node);
void xenbus_ring_ops_init(void);
int xenbus_dev_request_and_reply(struct xsd_sockmsg *msg, void *par);
void xenbus_dev_queue_reply(struct xb_req_data *req);
extern unsigned int xb_dev_generation_id;
#endif