![Alex Zeffertt](/assets/img/avatar_default.png)
The xenfs filesystem exports various interfaces to usermode. Initially this exports a file to allow usermode to interact with xenbus/xenstore. Traditionally this appeared in /proc/xen. Rather than extending procfs, this patch adds a backward-compat mountpoint on /proc/xen, and provides a xenfs filesystem which can be mounted there. Signed-off-by: Alex Zeffertt <alex.zeffertt@eu.citrix.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
982 lines
24 KiB
C
982 lines
24 KiB
C
/******************************************************************************
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* Talks to Xen Store to figure out what devices we have.
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*
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* Copyright (C) 2005 Rusty Russell, IBM Corporation
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* Copyright (C) 2005 Mike Wray, Hewlett-Packard
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* Copyright (C) 2005, 2006 XenSource Ltd
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version 2
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* as published by the Free Software Foundation; or, when distributed
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* separately from the Linux kernel or incorporated into other
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* software packages, subject to the following license:
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this source file (the "Software"), to deal in the Software without
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* restriction, including without limitation the rights to use, copy, modify,
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* merge, publish, distribute, sublicense, and/or sell copies of the Software,
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* and to permit persons to whom the Software is furnished to do so, subject to
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* the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*/
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#define DPRINTK(fmt, args...) \
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pr_debug("xenbus_probe (%s:%d) " fmt ".\n", \
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__func__, __LINE__, ##args)
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#include <linux/kernel.h>
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#include <linux/err.h>
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#include <linux/string.h>
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#include <linux/ctype.h>
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#include <linux/fcntl.h>
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#include <linux/mm.h>
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#include <linux/proc_fs.h>
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#include <linux/notifier.h>
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#include <linux/kthread.h>
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#include <linux/mutex.h>
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#include <linux/io.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/xen/hypervisor.h>
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#include <xen/xenbus.h>
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#include <xen/events.h>
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#include <xen/page.h>
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#include "xenbus_comms.h"
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#include "xenbus_probe.h"
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int xen_store_evtchn;
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EXPORT_SYMBOL(xen_store_evtchn);
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struct xenstore_domain_interface *xen_store_interface;
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static unsigned long xen_store_mfn;
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static BLOCKING_NOTIFIER_HEAD(xenstore_chain);
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static void wait_for_devices(struct xenbus_driver *xendrv);
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static int xenbus_probe_frontend(const char *type, const char *name);
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static void xenbus_dev_shutdown(struct device *_dev);
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/* If something in array of ids matches this device, return it. */
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static const struct xenbus_device_id *
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match_device(const struct xenbus_device_id *arr, struct xenbus_device *dev)
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{
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for (; *arr->devicetype != '\0'; arr++) {
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if (!strcmp(arr->devicetype, dev->devicetype))
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return arr;
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}
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return NULL;
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}
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int xenbus_match(struct device *_dev, struct device_driver *_drv)
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{
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struct xenbus_driver *drv = to_xenbus_driver(_drv);
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if (!drv->ids)
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return 0;
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return match_device(drv->ids, to_xenbus_device(_dev)) != NULL;
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}
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static int xenbus_uevent(struct device *_dev, struct kobj_uevent_env *env)
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{
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struct xenbus_device *dev = to_xenbus_device(_dev);
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if (add_uevent_var(env, "MODALIAS=xen:%s", dev->devicetype))
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return -ENOMEM;
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return 0;
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}
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/* device/<type>/<id> => <type>-<id> */
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static int frontend_bus_id(char bus_id[XEN_BUS_ID_SIZE], const char *nodename)
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{
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nodename = strchr(nodename, '/');
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if (!nodename || strlen(nodename + 1) >= XEN_BUS_ID_SIZE) {
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printk(KERN_WARNING "XENBUS: bad frontend %s\n", nodename);
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return -EINVAL;
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}
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strlcpy(bus_id, nodename + 1, XEN_BUS_ID_SIZE);
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if (!strchr(bus_id, '/')) {
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printk(KERN_WARNING "XENBUS: bus_id %s no slash\n", bus_id);
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return -EINVAL;
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}
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*strchr(bus_id, '/') = '-';
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return 0;
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}
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static void free_otherend_details(struct xenbus_device *dev)
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{
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kfree(dev->otherend);
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dev->otherend = NULL;
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}
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static void free_otherend_watch(struct xenbus_device *dev)
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{
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if (dev->otherend_watch.node) {
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unregister_xenbus_watch(&dev->otherend_watch);
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kfree(dev->otherend_watch.node);
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dev->otherend_watch.node = NULL;
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}
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}
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int read_otherend_details(struct xenbus_device *xendev,
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char *id_node, char *path_node)
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{
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int err = xenbus_gather(XBT_NIL, xendev->nodename,
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id_node, "%i", &xendev->otherend_id,
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path_node, NULL, &xendev->otherend,
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NULL);
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if (err) {
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xenbus_dev_fatal(xendev, err,
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"reading other end details from %s",
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xendev->nodename);
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return err;
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}
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if (strlen(xendev->otherend) == 0 ||
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!xenbus_exists(XBT_NIL, xendev->otherend, "")) {
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xenbus_dev_fatal(xendev, -ENOENT,
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"unable to read other end from %s. "
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"missing or inaccessible.",
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xendev->nodename);
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free_otherend_details(xendev);
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return -ENOENT;
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}
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return 0;
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}
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static int read_backend_details(struct xenbus_device *xendev)
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{
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return read_otherend_details(xendev, "backend-id", "backend");
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}
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static struct device_attribute xenbus_dev_attrs[] = {
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__ATTR_NULL
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};
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/* Bus type for frontend drivers. */
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static struct xen_bus_type xenbus_frontend = {
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.root = "device",
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.levels = 2, /* device/type/<id> */
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.get_bus_id = frontend_bus_id,
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.probe = xenbus_probe_frontend,
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.bus = {
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.name = "xen",
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.match = xenbus_match,
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.uevent = xenbus_uevent,
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.probe = xenbus_dev_probe,
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.remove = xenbus_dev_remove,
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.shutdown = xenbus_dev_shutdown,
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.dev_attrs = xenbus_dev_attrs,
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},
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};
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static void otherend_changed(struct xenbus_watch *watch,
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const char **vec, unsigned int len)
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{
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struct xenbus_device *dev =
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container_of(watch, struct xenbus_device, otherend_watch);
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struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver);
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enum xenbus_state state;
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/* Protect us against watches firing on old details when the otherend
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details change, say immediately after a resume. */
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if (!dev->otherend ||
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strncmp(dev->otherend, vec[XS_WATCH_PATH],
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strlen(dev->otherend))) {
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dev_dbg(&dev->dev, "Ignoring watch at %s\n",
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vec[XS_WATCH_PATH]);
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return;
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}
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state = xenbus_read_driver_state(dev->otherend);
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dev_dbg(&dev->dev, "state is %d, (%s), %s, %s\n",
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state, xenbus_strstate(state), dev->otherend_watch.node,
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vec[XS_WATCH_PATH]);
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/*
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* Ignore xenbus transitions during shutdown. This prevents us doing
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* work that can fail e.g., when the rootfs is gone.
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*/
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if (system_state > SYSTEM_RUNNING) {
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struct xen_bus_type *bus = bus;
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bus = container_of(dev->dev.bus, struct xen_bus_type, bus);
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/* If we're frontend, drive the state machine to Closed. */
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/* This should cause the backend to release our resources. */
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if ((bus == &xenbus_frontend) && (state == XenbusStateClosing))
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xenbus_frontend_closed(dev);
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return;
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}
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if (drv->otherend_changed)
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drv->otherend_changed(dev, state);
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}
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static int talk_to_otherend(struct xenbus_device *dev)
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{
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struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver);
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free_otherend_watch(dev);
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free_otherend_details(dev);
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return drv->read_otherend_details(dev);
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}
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static int watch_otherend(struct xenbus_device *dev)
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{
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return xenbus_watch_pathfmt(dev, &dev->otherend_watch, otherend_changed,
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"%s/%s", dev->otherend, "state");
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}
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int xenbus_dev_probe(struct device *_dev)
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{
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struct xenbus_device *dev = to_xenbus_device(_dev);
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struct xenbus_driver *drv = to_xenbus_driver(_dev->driver);
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const struct xenbus_device_id *id;
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int err;
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DPRINTK("%s", dev->nodename);
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if (!drv->probe) {
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err = -ENODEV;
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goto fail;
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}
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id = match_device(drv->ids, dev);
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if (!id) {
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err = -ENODEV;
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goto fail;
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}
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err = talk_to_otherend(dev);
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if (err) {
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dev_warn(&dev->dev, "talk_to_otherend on %s failed.\n",
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dev->nodename);
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return err;
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}
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err = drv->probe(dev, id);
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if (err)
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goto fail;
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err = watch_otherend(dev);
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if (err) {
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dev_warn(&dev->dev, "watch_otherend on %s failed.\n",
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dev->nodename);
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return err;
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}
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return 0;
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fail:
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xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename);
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xenbus_switch_state(dev, XenbusStateClosed);
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return -ENODEV;
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}
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int xenbus_dev_remove(struct device *_dev)
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{
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struct xenbus_device *dev = to_xenbus_device(_dev);
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struct xenbus_driver *drv = to_xenbus_driver(_dev->driver);
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DPRINTK("%s", dev->nodename);
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free_otherend_watch(dev);
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free_otherend_details(dev);
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if (drv->remove)
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drv->remove(dev);
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xenbus_switch_state(dev, XenbusStateClosed);
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return 0;
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}
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static void xenbus_dev_shutdown(struct device *_dev)
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{
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struct xenbus_device *dev = to_xenbus_device(_dev);
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unsigned long timeout = 5*HZ;
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DPRINTK("%s", dev->nodename);
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get_device(&dev->dev);
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if (dev->state != XenbusStateConnected) {
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printk(KERN_INFO "%s: %s: %s != Connected, skipping\n", __func__,
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dev->nodename, xenbus_strstate(dev->state));
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goto out;
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}
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xenbus_switch_state(dev, XenbusStateClosing);
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timeout = wait_for_completion_timeout(&dev->down, timeout);
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if (!timeout)
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printk(KERN_INFO "%s: %s timeout closing device\n",
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__func__, dev->nodename);
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out:
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put_device(&dev->dev);
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}
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int xenbus_register_driver_common(struct xenbus_driver *drv,
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struct xen_bus_type *bus,
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struct module *owner,
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const char *mod_name)
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{
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drv->driver.name = drv->name;
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drv->driver.bus = &bus->bus;
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drv->driver.owner = owner;
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drv->driver.mod_name = mod_name;
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return driver_register(&drv->driver);
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}
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int __xenbus_register_frontend(struct xenbus_driver *drv,
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struct module *owner, const char *mod_name)
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{
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int ret;
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drv->read_otherend_details = read_backend_details;
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ret = xenbus_register_driver_common(drv, &xenbus_frontend,
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owner, mod_name);
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if (ret)
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return ret;
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/* If this driver is loaded as a module wait for devices to attach. */
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wait_for_devices(drv);
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return 0;
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}
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EXPORT_SYMBOL_GPL(__xenbus_register_frontend);
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void xenbus_unregister_driver(struct xenbus_driver *drv)
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{
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driver_unregister(&drv->driver);
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}
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EXPORT_SYMBOL_GPL(xenbus_unregister_driver);
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struct xb_find_info
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{
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struct xenbus_device *dev;
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const char *nodename;
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};
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static int cmp_dev(struct device *dev, void *data)
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{
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struct xenbus_device *xendev = to_xenbus_device(dev);
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struct xb_find_info *info = data;
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if (!strcmp(xendev->nodename, info->nodename)) {
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info->dev = xendev;
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get_device(dev);
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return 1;
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}
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return 0;
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}
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struct xenbus_device *xenbus_device_find(const char *nodename,
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struct bus_type *bus)
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{
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struct xb_find_info info = { .dev = NULL, .nodename = nodename };
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bus_for_each_dev(bus, NULL, &info, cmp_dev);
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return info.dev;
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}
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static int cleanup_dev(struct device *dev, void *data)
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{
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struct xenbus_device *xendev = to_xenbus_device(dev);
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struct xb_find_info *info = data;
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int len = strlen(info->nodename);
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DPRINTK("%s", info->nodename);
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/* Match the info->nodename path, or any subdirectory of that path. */
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if (strncmp(xendev->nodename, info->nodename, len))
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return 0;
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/* If the node name is longer, ensure it really is a subdirectory. */
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if ((strlen(xendev->nodename) > len) && (xendev->nodename[len] != '/'))
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return 0;
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info->dev = xendev;
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get_device(dev);
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return 1;
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}
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static void xenbus_cleanup_devices(const char *path, struct bus_type *bus)
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{
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struct xb_find_info info = { .nodename = path };
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do {
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info.dev = NULL;
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bus_for_each_dev(bus, NULL, &info, cleanup_dev);
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if (info.dev) {
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device_unregister(&info.dev->dev);
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put_device(&info.dev->dev);
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}
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} while (info.dev);
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}
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static void xenbus_dev_release(struct device *dev)
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{
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if (dev)
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kfree(to_xenbus_device(dev));
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}
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static ssize_t xendev_show_nodename(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return sprintf(buf, "%s\n", to_xenbus_device(dev)->nodename);
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}
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DEVICE_ATTR(nodename, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_nodename, NULL);
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static ssize_t xendev_show_devtype(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return sprintf(buf, "%s\n", to_xenbus_device(dev)->devicetype);
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}
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DEVICE_ATTR(devtype, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_devtype, NULL);
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|
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static ssize_t xendev_show_modalias(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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return sprintf(buf, "xen:%s\n", to_xenbus_device(dev)->devicetype);
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}
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DEVICE_ATTR(modalias, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_modalias, NULL);
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|
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int xenbus_probe_node(struct xen_bus_type *bus,
|
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const char *type,
|
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const char *nodename)
|
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{
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char devname[XEN_BUS_ID_SIZE];
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int err;
|
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struct xenbus_device *xendev;
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size_t stringlen;
|
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char *tmpstring;
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|
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enum xenbus_state state = xenbus_read_driver_state(nodename);
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|
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if (state != XenbusStateInitialising) {
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/* Device is not new, so ignore it. This can happen if a
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device is going away after switching to Closed. */
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return 0;
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}
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|
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stringlen = strlen(nodename) + 1 + strlen(type) + 1;
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xendev = kzalloc(sizeof(*xendev) + stringlen, GFP_KERNEL);
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if (!xendev)
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return -ENOMEM;
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|
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xendev->state = XenbusStateInitialising;
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|
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/* Copy the strings into the extra space. */
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|
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tmpstring = (char *)(xendev + 1);
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strcpy(tmpstring, nodename);
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xendev->nodename = tmpstring;
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|
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tmpstring += strlen(tmpstring) + 1;
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strcpy(tmpstring, type);
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xendev->devicetype = tmpstring;
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init_completion(&xendev->down);
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|
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xendev->dev.bus = &bus->bus;
|
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xendev->dev.release = xenbus_dev_release;
|
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|
|
err = bus->get_bus_id(devname, xendev->nodename);
|
|
if (err)
|
|
goto fail;
|
|
|
|
dev_set_name(&xendev->dev, devname);
|
|
|
|
/* Register with generic device framework. */
|
|
err = device_register(&xendev->dev);
|
|
if (err)
|
|
goto fail;
|
|
|
|
err = device_create_file(&xendev->dev, &dev_attr_nodename);
|
|
if (err)
|
|
goto fail_unregister;
|
|
|
|
err = device_create_file(&xendev->dev, &dev_attr_devtype);
|
|
if (err)
|
|
goto fail_remove_nodename;
|
|
|
|
err = device_create_file(&xendev->dev, &dev_attr_modalias);
|
|
if (err)
|
|
goto fail_remove_devtype;
|
|
|
|
return 0;
|
|
fail_remove_devtype:
|
|
device_remove_file(&xendev->dev, &dev_attr_devtype);
|
|
fail_remove_nodename:
|
|
device_remove_file(&xendev->dev, &dev_attr_nodename);
|
|
fail_unregister:
|
|
device_unregister(&xendev->dev);
|
|
fail:
|
|
kfree(xendev);
|
|
return err;
|
|
}
|
|
|
|
/* device/<typename>/<name> */
|
|
static int xenbus_probe_frontend(const char *type, const char *name)
|
|
{
|
|
char *nodename;
|
|
int err;
|
|
|
|
nodename = kasprintf(GFP_KERNEL, "%s/%s/%s",
|
|
xenbus_frontend.root, type, name);
|
|
if (!nodename)
|
|
return -ENOMEM;
|
|
|
|
DPRINTK("%s", nodename);
|
|
|
|
err = xenbus_probe_node(&xenbus_frontend, type, nodename);
|
|
kfree(nodename);
|
|
return err;
|
|
}
|
|
|
|
static int xenbus_probe_device_type(struct xen_bus_type *bus, const char *type)
|
|
{
|
|
int err = 0;
|
|
char **dir;
|
|
unsigned int dir_n = 0;
|
|
int i;
|
|
|
|
dir = xenbus_directory(XBT_NIL, bus->root, type, &dir_n);
|
|
if (IS_ERR(dir))
|
|
return PTR_ERR(dir);
|
|
|
|
for (i = 0; i < dir_n; i++) {
|
|
err = bus->probe(type, dir[i]);
|
|
if (err)
|
|
break;
|
|
}
|
|
kfree(dir);
|
|
return err;
|
|
}
|
|
|
|
int xenbus_probe_devices(struct xen_bus_type *bus)
|
|
{
|
|
int err = 0;
|
|
char **dir;
|
|
unsigned int i, dir_n;
|
|
|
|
dir = xenbus_directory(XBT_NIL, bus->root, "", &dir_n);
|
|
if (IS_ERR(dir))
|
|
return PTR_ERR(dir);
|
|
|
|
for (i = 0; i < dir_n; i++) {
|
|
err = xenbus_probe_device_type(bus, dir[i]);
|
|
if (err)
|
|
break;
|
|
}
|
|
kfree(dir);
|
|
return err;
|
|
}
|
|
|
|
static unsigned int char_count(const char *str, char c)
|
|
{
|
|
unsigned int i, ret = 0;
|
|
|
|
for (i = 0; str[i]; i++)
|
|
if (str[i] == c)
|
|
ret++;
|
|
return ret;
|
|
}
|
|
|
|
static int strsep_len(const char *str, char c, unsigned int len)
|
|
{
|
|
unsigned int i;
|
|
|
|
for (i = 0; str[i]; i++)
|
|
if (str[i] == c) {
|
|
if (len == 0)
|
|
return i;
|
|
len--;
|
|
}
|
|
return (len == 0) ? i : -ERANGE;
|
|
}
|
|
|
|
void xenbus_dev_changed(const char *node, struct xen_bus_type *bus)
|
|
{
|
|
int exists, rootlen;
|
|
struct xenbus_device *dev;
|
|
char type[XEN_BUS_ID_SIZE];
|
|
const char *p, *root;
|
|
|
|
if (char_count(node, '/') < 2)
|
|
return;
|
|
|
|
exists = xenbus_exists(XBT_NIL, node, "");
|
|
if (!exists) {
|
|
xenbus_cleanup_devices(node, &bus->bus);
|
|
return;
|
|
}
|
|
|
|
/* backend/<type>/... or device/<type>/... */
|
|
p = strchr(node, '/') + 1;
|
|
snprintf(type, XEN_BUS_ID_SIZE, "%.*s", (int)strcspn(p, "/"), p);
|
|
type[XEN_BUS_ID_SIZE-1] = '\0';
|
|
|
|
rootlen = strsep_len(node, '/', bus->levels);
|
|
if (rootlen < 0)
|
|
return;
|
|
root = kasprintf(GFP_KERNEL, "%.*s", rootlen, node);
|
|
if (!root)
|
|
return;
|
|
|
|
dev = xenbus_device_find(root, &bus->bus);
|
|
if (!dev)
|
|
xenbus_probe_node(bus, type, root);
|
|
else
|
|
put_device(&dev->dev);
|
|
|
|
kfree(root);
|
|
}
|
|
|
|
static void frontend_changed(struct xenbus_watch *watch,
|
|
const char **vec, unsigned int len)
|
|
{
|
|
DPRINTK("");
|
|
|
|
xenbus_dev_changed(vec[XS_WATCH_PATH], &xenbus_frontend);
|
|
}
|
|
|
|
/* We watch for devices appearing and vanishing. */
|
|
static struct xenbus_watch fe_watch = {
|
|
.node = "device",
|
|
.callback = frontend_changed,
|
|
};
|
|
|
|
static int suspend_dev(struct device *dev, void *data)
|
|
{
|
|
int err = 0;
|
|
struct xenbus_driver *drv;
|
|
struct xenbus_device *xdev;
|
|
|
|
DPRINTK("");
|
|
|
|
if (dev->driver == NULL)
|
|
return 0;
|
|
drv = to_xenbus_driver(dev->driver);
|
|
xdev = container_of(dev, struct xenbus_device, dev);
|
|
if (drv->suspend)
|
|
err = drv->suspend(xdev);
|
|
if (err)
|
|
printk(KERN_WARNING
|
|
"xenbus: suspend %s failed: %i\n", dev_name(dev), err);
|
|
return 0;
|
|
}
|
|
|
|
static int suspend_cancel_dev(struct device *dev, void *data)
|
|
{
|
|
int err = 0;
|
|
struct xenbus_driver *drv;
|
|
struct xenbus_device *xdev;
|
|
|
|
DPRINTK("");
|
|
|
|
if (dev->driver == NULL)
|
|
return 0;
|
|
drv = to_xenbus_driver(dev->driver);
|
|
xdev = container_of(dev, struct xenbus_device, dev);
|
|
if (drv->suspend_cancel)
|
|
err = drv->suspend_cancel(xdev);
|
|
if (err)
|
|
printk(KERN_WARNING
|
|
"xenbus: suspend_cancel %s failed: %i\n",
|
|
dev_name(dev), err);
|
|
return 0;
|
|
}
|
|
|
|
static int resume_dev(struct device *dev, void *data)
|
|
{
|
|
int err;
|
|
struct xenbus_driver *drv;
|
|
struct xenbus_device *xdev;
|
|
|
|
DPRINTK("");
|
|
|
|
if (dev->driver == NULL)
|
|
return 0;
|
|
|
|
drv = to_xenbus_driver(dev->driver);
|
|
xdev = container_of(dev, struct xenbus_device, dev);
|
|
|
|
err = talk_to_otherend(xdev);
|
|
if (err) {
|
|
printk(KERN_WARNING
|
|
"xenbus: resume (talk_to_otherend) %s failed: %i\n",
|
|
dev_name(dev), err);
|
|
return err;
|
|
}
|
|
|
|
xdev->state = XenbusStateInitialising;
|
|
|
|
if (drv->resume) {
|
|
err = drv->resume(xdev);
|
|
if (err) {
|
|
printk(KERN_WARNING
|
|
"xenbus: resume %s failed: %i\n",
|
|
dev_name(dev), err);
|
|
return err;
|
|
}
|
|
}
|
|
|
|
err = watch_otherend(xdev);
|
|
if (err) {
|
|
printk(KERN_WARNING
|
|
"xenbus_probe: resume (watch_otherend) %s failed: "
|
|
"%d.\n", dev_name(dev), err);
|
|
return err;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void xenbus_suspend(void)
|
|
{
|
|
DPRINTK("");
|
|
|
|
bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, suspend_dev);
|
|
xenbus_backend_suspend(suspend_dev);
|
|
xs_suspend();
|
|
}
|
|
EXPORT_SYMBOL_GPL(xenbus_suspend);
|
|
|
|
void xenbus_resume(void)
|
|
{
|
|
xb_init_comms();
|
|
xs_resume();
|
|
bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, resume_dev);
|
|
xenbus_backend_resume(resume_dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xenbus_resume);
|
|
|
|
void xenbus_suspend_cancel(void)
|
|
{
|
|
xs_suspend_cancel();
|
|
bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, suspend_cancel_dev);
|
|
xenbus_backend_resume(suspend_cancel_dev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(xenbus_suspend_cancel);
|
|
|
|
/* A flag to determine if xenstored is 'ready' (i.e. has started) */
|
|
int xenstored_ready = 0;
|
|
|
|
|
|
int register_xenstore_notifier(struct notifier_block *nb)
|
|
{
|
|
int ret = 0;
|
|
|
|
if (xenstored_ready > 0)
|
|
ret = nb->notifier_call(nb, 0, NULL);
|
|
else
|
|
blocking_notifier_chain_register(&xenstore_chain, nb);
|
|
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(register_xenstore_notifier);
|
|
|
|
void unregister_xenstore_notifier(struct notifier_block *nb)
|
|
{
|
|
blocking_notifier_chain_unregister(&xenstore_chain, nb);
|
|
}
|
|
EXPORT_SYMBOL_GPL(unregister_xenstore_notifier);
|
|
|
|
void xenbus_probe(struct work_struct *unused)
|
|
{
|
|
BUG_ON((xenstored_ready <= 0));
|
|
|
|
/* Enumerate devices in xenstore and watch for changes. */
|
|
xenbus_probe_devices(&xenbus_frontend);
|
|
register_xenbus_watch(&fe_watch);
|
|
xenbus_backend_probe_and_watch();
|
|
|
|
/* Notify others that xenstore is up */
|
|
blocking_notifier_call_chain(&xenstore_chain, 0, NULL);
|
|
}
|
|
|
|
static int __init xenbus_probe_init(void)
|
|
{
|
|
int err = 0;
|
|
|
|
DPRINTK("");
|
|
|
|
err = -ENODEV;
|
|
if (!xen_domain())
|
|
goto out_error;
|
|
|
|
/* Register ourselves with the kernel bus subsystem */
|
|
err = bus_register(&xenbus_frontend.bus);
|
|
if (err)
|
|
goto out_error;
|
|
|
|
err = xenbus_backend_bus_register();
|
|
if (err)
|
|
goto out_unreg_front;
|
|
|
|
/*
|
|
* Domain0 doesn't have a store_evtchn or store_mfn yet.
|
|
*/
|
|
if (xen_initial_domain()) {
|
|
/* dom0 not yet supported */
|
|
} else {
|
|
xenstored_ready = 1;
|
|
xen_store_evtchn = xen_start_info->store_evtchn;
|
|
xen_store_mfn = xen_start_info->store_mfn;
|
|
}
|
|
xen_store_interface = mfn_to_virt(xen_store_mfn);
|
|
|
|
/* Initialize the interface to xenstore. */
|
|
err = xs_init();
|
|
if (err) {
|
|
printk(KERN_WARNING
|
|
"XENBUS: Error initializing xenstore comms: %i\n", err);
|
|
goto out_unreg_back;
|
|
}
|
|
|
|
if (!xen_initial_domain())
|
|
xenbus_probe(NULL);
|
|
|
|
#ifdef CONFIG_XEN_COMPAT_XENFS
|
|
/*
|
|
* Create xenfs mountpoint in /proc for compatibility with
|
|
* utilities that expect to find "xenbus" under "/proc/xen".
|
|
*/
|
|
proc_mkdir("xen", NULL);
|
|
#endif
|
|
|
|
return 0;
|
|
|
|
out_unreg_back:
|
|
xenbus_backend_bus_unregister();
|
|
|
|
out_unreg_front:
|
|
bus_unregister(&xenbus_frontend.bus);
|
|
|
|
out_error:
|
|
return err;
|
|
}
|
|
|
|
postcore_initcall(xenbus_probe_init);
|
|
|
|
MODULE_LICENSE("GPL");
|
|
|
|
static int is_disconnected_device(struct device *dev, void *data)
|
|
{
|
|
struct xenbus_device *xendev = to_xenbus_device(dev);
|
|
struct device_driver *drv = data;
|
|
struct xenbus_driver *xendrv;
|
|
|
|
/*
|
|
* A device with no driver will never connect. We care only about
|
|
* devices which should currently be in the process of connecting.
|
|
*/
|
|
if (!dev->driver)
|
|
return 0;
|
|
|
|
/* Is this search limited to a particular driver? */
|
|
if (drv && (dev->driver != drv))
|
|
return 0;
|
|
|
|
xendrv = to_xenbus_driver(dev->driver);
|
|
return (xendev->state != XenbusStateConnected ||
|
|
(xendrv->is_ready && !xendrv->is_ready(xendev)));
|
|
}
|
|
|
|
static int exists_disconnected_device(struct device_driver *drv)
|
|
{
|
|
return bus_for_each_dev(&xenbus_frontend.bus, NULL, drv,
|
|
is_disconnected_device);
|
|
}
|
|
|
|
static int print_device_status(struct device *dev, void *data)
|
|
{
|
|
struct xenbus_device *xendev = to_xenbus_device(dev);
|
|
struct device_driver *drv = data;
|
|
|
|
/* Is this operation limited to a particular driver? */
|
|
if (drv && (dev->driver != drv))
|
|
return 0;
|
|
|
|
if (!dev->driver) {
|
|
/* Information only: is this too noisy? */
|
|
printk(KERN_INFO "XENBUS: Device with no driver: %s\n",
|
|
xendev->nodename);
|
|
} else if (xendev->state != XenbusStateConnected) {
|
|
printk(KERN_WARNING "XENBUS: Timeout connecting "
|
|
"to device: %s (state %d)\n",
|
|
xendev->nodename, xendev->state);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* We only wait for device setup after most initcalls have run. */
|
|
static int ready_to_wait_for_devices;
|
|
|
|
/*
|
|
* On a 10 second timeout, wait for all devices currently configured. We need
|
|
* to do this to guarantee that the filesystems and / or network devices
|
|
* needed for boot are available, before we can allow the boot to proceed.
|
|
*
|
|
* This needs to be on a late_initcall, to happen after the frontend device
|
|
* drivers have been initialised, but before the root fs is mounted.
|
|
*
|
|
* A possible improvement here would be to have the tools add a per-device
|
|
* flag to the store entry, indicating whether it is needed at boot time.
|
|
* This would allow people who knew what they were doing to accelerate their
|
|
* boot slightly, but of course needs tools or manual intervention to set up
|
|
* those flags correctly.
|
|
*/
|
|
static void wait_for_devices(struct xenbus_driver *xendrv)
|
|
{
|
|
unsigned long timeout = jiffies + 10*HZ;
|
|
struct device_driver *drv = xendrv ? &xendrv->driver : NULL;
|
|
|
|
if (!ready_to_wait_for_devices || !xen_domain())
|
|
return;
|
|
|
|
while (exists_disconnected_device(drv)) {
|
|
if (time_after(jiffies, timeout))
|
|
break;
|
|
schedule_timeout_interruptible(HZ/10);
|
|
}
|
|
|
|
bus_for_each_dev(&xenbus_frontend.bus, NULL, drv,
|
|
print_device_status);
|
|
}
|
|
|
|
#ifndef MODULE
|
|
static int __init boot_wait_for_devices(void)
|
|
{
|
|
ready_to_wait_for_devices = 1;
|
|
wait_for_devices(NULL);
|
|
return 0;
|
|
}
|
|
|
|
late_initcall(boot_wait_for_devices);
|
|
#endif
|