linux/drivers/xen/xenbus/xenbus_probe_backend.c

/******************************************************************************
 * Talks to Xen Store to figure out what devices we have (backend half).
 *
 * Copyright (C) 2005 Rusty Russell, IBM Corporation
 * Copyright (C) 2005 Mike Wray, Hewlett-Packard
 * Copyright (C) 2005, 2006 XenSource Ltd
 * Copyright (C) 2007 Solarflare Communications, Inc.
 *
 * 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.
 */

#define pr_fmt(fmt) …

#define DPRINTK(fmt, ...) …

#include <linux/kernel.h>
#include <linux/err.h>
#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/fcntl.h>
#include <linux/mm.h>
#include <linux/notifier.h>
#include <linux/export.h>
#include <linux/semaphore.h>

#include <asm/page.h>
#include <asm/xen/hypervisor.h>
#include <asm/hypervisor.h>
#include <xen/xenbus.h>
#include <xen/features.h>

#include "xenbus.h"

/* backend/<type>/<fe-uuid>/<id> => <type>-<fe-domid>-<id> */
static int backend_bus_id(char bus_id[XEN_BUS_ID_SIZE], const char *nodename)
{ … }

static int xenbus_uevent_backend(const struct device *dev,
				 struct kobj_uevent_env *env)
{ … }

/* backend/<typename>/<frontend-uuid>/<name> */
static int xenbus_probe_backend_unit(struct xen_bus_type *bus,
				     const char *dir,
				     const char *type,
				     const char *name)
{ … }

/* backend/<typename>/<frontend-domid> */
static int xenbus_probe_backend(struct xen_bus_type *bus, const char *type,
				const char *domid)
{ … }

static bool frontend_will_handle(struct xenbus_watch *watch,
				 const char *path, const char *token)
{ … }

static void frontend_changed(struct xenbus_watch *watch,
			     const char *path, const char *token)
{ … }

static struct xen_bus_type xenbus_backend = …;

static void backend_changed(struct xenbus_watch *watch,
			    const char *path, const char *token)
{ … }

static struct xenbus_watch be_watch = …;

static int read_frontend_details(struct xenbus_device *xendev)
{ … }

int xenbus_dev_is_online(struct xenbus_device *dev)
{ … }
EXPORT_SYMBOL_GPL(…);

int __xenbus_register_backend(struct xenbus_driver *drv, struct module *owner,
			      const char *mod_name)
{ … }
EXPORT_SYMBOL_GPL(…);

static int backend_probe_and_watch(struct notifier_block *notifier,
				   unsigned long event,
				   void *data)
{ … }

static int backend_reclaim_memory(struct device *dev, void *data)
{ … }

/*
 * Returns 0 always because we are using shrinker to only detect memory
 * pressure.
 */
static unsigned long backend_shrink_memory_count(struct shrinker *shrinker,
				struct shrink_control *sc)
{ … }

static int __init xenbus_probe_backend_init(void)
{ … }
subsys_initcall(xenbus_probe_backend_init);