--- /dev/null
+/******************************************************************************
+ * Talks to Xen Store to figure out what devices we have.
+ *
+ * Copyright (C) 2005 Rusty Russell, IBM Corporation
+ * Copyright (C) 2005 Mike Wray, Hewlett-Packard
+ * Copyright (C) 2005, 2006 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.
+ */
+
+#define DPRINTK(fmt, args...) \
+ pr_debug("xenbus_probe (%s:%d) " fmt ".\n", \
+ __FUNCTION__, __LINE__, ##args)
+
+#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/kthread.h>
+
+#include <asm/io.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+#include <asm/hypervisor.h>
+#include <xen/xenbus.h>
+#include <xen/xen_proc.h>
+#include <xen/evtchn.h>
+#include <xen/features.h>
+
+#include "xenbus_comms.h"
+
+extern struct mutex xenwatch_mutex;
+
+static BLOCKING_NOTIFIER_HEAD(xenstore_notifier_list);
+
+static void wait_for_devices(struct xenbus_driver *xendrv);
+
+/* If something in array of ids matches this device, return it. */
+static const struct xenbus_device_id *
+match_device(const struct xenbus_device_id *arr, struct xenbus_device *dev)
+{
+ for (; *arr->devicetype != '\0'; arr++) {
+ if (!strcmp(arr->devicetype, dev->devicetype))
+ return arr;
+ }
+ return NULL;
+}
+
+static int xenbus_match(struct device *_dev, struct device_driver *_drv)
+{
+ struct xenbus_driver *drv = to_xenbus_driver(_drv);
+
+ if (!drv->ids)
+ return 0;
+
+ return match_device(drv->ids, to_xenbus_device(_dev)) != NULL;
+}
+
+struct xen_bus_type
+{
+ char *root;
+ unsigned int levels;
+ int (*get_bus_id)(char bus_id[BUS_ID_SIZE], const char *nodename);
+ int (*probe)(const char *type, const char *dir);
+ struct bus_type bus;
+ struct device dev;
+};
+
+
+/* device/<type>/<id> => <type>-<id> */
+static int frontend_bus_id(char bus_id[BUS_ID_SIZE], const char *nodename)
+{
+ nodename = strchr(nodename, '/');
+ if (!nodename || strlen(nodename + 1) >= BUS_ID_SIZE) {
+ printk(KERN_WARNING "XENBUS: bad frontend %s\n", nodename);
+ return -EINVAL;
+ }
+
+ strlcpy(bus_id, nodename + 1, BUS_ID_SIZE);
+ if (!strchr(bus_id, '/')) {
+ printk(KERN_WARNING "XENBUS: bus_id %s no slash\n", bus_id);
+ return -EINVAL;
+ }
+ *strchr(bus_id, '/') = '-';
+ return 0;
+}
+
+
+static void free_otherend_details(struct xenbus_device *dev)
+{
+ kfree(dev->otherend);
+ dev->otherend = NULL;
+}
+
+
+static void free_otherend_watch(struct xenbus_device *dev)
+{
+ if (dev->otherend_watch.node) {
+ unregister_xenbus_watch(&dev->otherend_watch);
+ kfree(dev->otherend_watch.node);
+ dev->otherend_watch.node = NULL;
+ }
+}
+
+
+static int read_otherend_details(struct xenbus_device *xendev,
+ char *id_node, char *path_node)
+{
+ int err = xenbus_gather(XBT_NIL, xendev->nodename,
+ id_node, "%i", &xendev->otherend_id,
+ path_node, NULL, &xendev->otherend,
+ NULL);
+ if (err) {
+ xenbus_dev_fatal(xendev, err,
+ "reading other end details from %s",
+ xendev->nodename);
+ return err;
+ }
+ if (strlen(xendev->otherend) == 0 ||
+ !xenbus_exists(XBT_NIL, xendev->otherend, "")) {
+ xenbus_dev_fatal(xendev, -ENOENT,
+ "unable to read other end from %s. "
+ "missing or inaccessible.",
+ xendev->nodename);
+ free_otherend_details(xendev);
+ return -ENOENT;
+ }
+
+ return 0;
+}
+
+
+static int read_backend_details(struct xenbus_device *xendev)
+{
+ return read_otherend_details(xendev, "backend-id", "backend");
+}
+
+
+static int read_frontend_details(struct xenbus_device *xendev)
+{
+ return read_otherend_details(xendev, "frontend-id", "frontend");
+}
+
+
+/* Bus type for frontend drivers. */
+static int xenbus_probe_frontend(const char *type, const char *name);
+static struct xen_bus_type xenbus_frontend = {
+ .root = "device",
+ .levels = 2, /* device/type/<id> */
+ .get_bus_id = frontend_bus_id,
+ .probe = xenbus_probe_frontend,
+ .bus = {
+ .name = "xen",
+ .match = xenbus_match,
+ },
+ .dev = {
+ .bus_id = "xen",
+ },
+};
+
+/* backend/<type>/<fe-uuid>/<id> => <type>-<fe-domid>-<id> */
+static int backend_bus_id(char bus_id[BUS_ID_SIZE], const char *nodename)
+{
+ int domid, err;
+ const char *devid, *type, *frontend;
+ unsigned int typelen;
+
+ type = strchr(nodename, '/');
+ if (!type)
+ return -EINVAL;
+ type++;
+ typelen = strcspn(type, "/");
+ if (!typelen || type[typelen] != '/')
+ return -EINVAL;
+
+ devid = strrchr(nodename, '/') + 1;
+
+ err = xenbus_gather(XBT_NIL, nodename, "frontend-id", "%i", &domid,
+ "frontend", NULL, &frontend,
+ NULL);
+ if (err)
+ return err;
+ if (strlen(frontend) == 0)
+ err = -ERANGE;
+ if (!err && !xenbus_exists(XBT_NIL, frontend, ""))
+ err = -ENOENT;
+
+ kfree(frontend);
+
+ if (err)
+ return err;
+
+ if (snprintf(bus_id, BUS_ID_SIZE,
+ "%.*s-%i-%s", typelen, type, domid, devid) >= BUS_ID_SIZE)
+ return -ENOSPC;
+ return 0;
+}
+
+static int xenbus_uevent_backend(struct device *dev, char **envp,
+ int num_envp, char *buffer, int buffer_size);
+static int xenbus_probe_backend(const char *type, const char *domid);
+static struct xen_bus_type xenbus_backend = {
+ .root = "backend",
+ .levels = 3, /* backend/type/<frontend>/<id> */
+ .get_bus_id = backend_bus_id,
+ .probe = xenbus_probe_backend,
+ .bus = {
+ .name = "xen-backend",
+ .match = xenbus_match,
+ .uevent = xenbus_uevent_backend,
+ },
+ .dev = {
+ .bus_id = "xen-backend",
+ },
+};
+
+static int xenbus_uevent_backend(struct device *dev, char **envp,
+ int num_envp, char *buffer, int buffer_size)
+{
+ struct xenbus_device *xdev;
+ struct xenbus_driver *drv;
+ int i = 0;
+ int length = 0;
+
+ DPRINTK("");
+
+ if (dev == NULL)
+ return -ENODEV;
+
+ xdev = to_xenbus_device(dev);
+ if (xdev == NULL)
+ return -ENODEV;
+
+ /* stuff we want to pass to /sbin/hotplug */
+ add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
+ "XENBUS_TYPE=%s", xdev->devicetype);
+
+ add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
+ "XENBUS_PATH=%s", xdev->nodename);
+
+ add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
+ "XENBUS_BASE_PATH=%s", xenbus_backend.root);
+
+ /* terminate, set to next free slot, shrink available space */
+ envp[i] = NULL;
+ envp = &envp[i];
+ num_envp -= i;
+ buffer = &buffer[length];
+ buffer_size -= length;
+
+ if (dev->driver) {
+ drv = to_xenbus_driver(dev->driver);
+ if (drv && drv->uevent)
+ return drv->uevent(xdev, envp, num_envp, buffer,
+ buffer_size);
+ }
+
+ return 0;
+}
+
+static void otherend_changed(struct xenbus_watch *watch,
+ const char **vec, unsigned int len)
+{
+ struct xenbus_device *dev =
+ container_of(watch, struct xenbus_device, otherend_watch);
+ struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver);
+ enum xenbus_state state;
+
+ /* Protect us against watches firing on old details when the otherend
+ details change, say immediately after a resume. */
+ if (!dev->otherend ||
+ strncmp(dev->otherend, vec[XS_WATCH_PATH],
+ strlen(dev->otherend))) {
+ DPRINTK("Ignoring watch at %s", vec[XS_WATCH_PATH]);
+ return;
+ }
+
+ state = xenbus_read_driver_state(dev->otherend);
+
+ DPRINTK("state is %d, %s, %s",
+ state, dev->otherend_watch.node, vec[XS_WATCH_PATH]);
+ if (drv->otherend_changed)
+ drv->otherend_changed(dev, state);
+}
+
+
+static int talk_to_otherend(struct xenbus_device *dev)
+{
+ struct xenbus_driver *drv = to_xenbus_driver(dev->dev.driver);
+
+ free_otherend_watch(dev);
+ free_otherend_details(dev);
+
+ return drv->read_otherend_details(dev);
+}
+
+
+static int watch_otherend(struct xenbus_device *dev)
+{
+ return xenbus_watch_path2(dev, dev->otherend, "state",
+ &dev->otherend_watch, otherend_changed);
+}
+
+
+static int xenbus_dev_probe(struct device *_dev)
+{
+ struct xenbus_device *dev = to_xenbus_device(_dev);
+ struct xenbus_driver *drv = to_xenbus_driver(_dev->driver);
+ const struct xenbus_device_id *id;
+ int err;
+
+ DPRINTK("");
+
+ if (!drv->probe) {
+ err = -ENODEV;
+ goto fail;
+ }
+
+ id = match_device(drv->ids, dev);
+ if (!id) {
+ err = -ENODEV;
+ goto fail;
+ }
+
+ err = talk_to_otherend(dev);
+ if (err) {
+ printk(KERN_WARNING
+ "xenbus_probe: talk_to_otherend on %s failed.\n",
+ dev->nodename);
+ return err;
+ }
+
+ err = drv->probe(dev, id);
+ if (err)
+ goto fail;
+
+ err = watch_otherend(dev);
+ if (err) {
+ printk(KERN_WARNING
+ "xenbus_probe: watch_otherend on %s failed.\n",
+ dev->nodename);
+ return err;
+ }
+
+ return 0;
+fail:
+ xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename);
+ xenbus_switch_state(dev, XenbusStateClosed);
+ return -ENODEV;
+}
+
+static int xenbus_dev_remove(struct device *_dev)
+{
+ struct xenbus_device *dev = to_xenbus_device(_dev);
+ struct xenbus_driver *drv = to_xenbus_driver(_dev->driver);
+
+ DPRINTK("");
+
+ free_otherend_watch(dev);
+ free_otherend_details(dev);
+
+ if (drv->remove)
+ drv->remove(dev);
+
+ xenbus_switch_state(dev, XenbusStateClosed);
+ return 0;
+}
+
+static int xenbus_register_driver_common(struct xenbus_driver *drv,
+ struct xen_bus_type *bus)
+{
+ int ret;
+
+ drv->driver.name = drv->name;
+ drv->driver.bus = &bus->bus;
+ drv->driver.owner = drv->owner;
+ drv->driver.probe = xenbus_dev_probe;
+ drv->driver.remove = xenbus_dev_remove;
+
+ mutex_lock(&xenwatch_mutex);
+ ret = driver_register(&drv->driver);
+ mutex_unlock(&xenwatch_mutex);
+ return ret;
+}
+
+int xenbus_register_frontend(struct xenbus_driver *drv)
+{
+ int ret;
+
+ drv->read_otherend_details = read_backend_details;
+
+ ret = xenbus_register_driver_common(drv, &xenbus_frontend);
+ if (ret)
+ return ret;
+
+ /* If this driver is loaded as a module wait for devices to attach. */
+ wait_for_devices(drv);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(xenbus_register_frontend);
+
+int xenbus_register_backend(struct xenbus_driver *drv)
+{
+ drv->read_otherend_details = read_frontend_details;
+
+ return xenbus_register_driver_common(drv, &xenbus_backend);
+}
+EXPORT_SYMBOL_GPL(xenbus_register_backend);
+
+void xenbus_unregister_driver(struct xenbus_driver *drv)
+{
+ driver_unregister(&drv->driver);
+}
+EXPORT_SYMBOL_GPL(xenbus_unregister_driver);
+
+struct xb_find_info
+{
+ struct xenbus_device *dev;
+ const char *nodename;
+};
+
+static int cmp_dev(struct device *dev, void *data)
+{
+ struct xenbus_device *xendev = to_xenbus_device(dev);
+ struct xb_find_info *info = data;
+
+ if (!strcmp(xendev->nodename, info->nodename)) {
+ info->dev = xendev;
+ get_device(dev);
+ return 1;
+ }
+ return 0;
+}
+
+struct xenbus_device *xenbus_device_find(const char *nodename,
+ struct bus_type *bus)
+{
+ struct xb_find_info info = { .dev = NULL, .nodename = nodename };
+
+ bus_for_each_dev(bus, NULL, &info, cmp_dev);
+ return info.dev;
+}
+
+static int cleanup_dev(struct device *dev, void *data)
+{
+ struct xenbus_device *xendev = to_xenbus_device(dev);
+ struct xb_find_info *info = data;
+ int len = strlen(info->nodename);
+
+ DPRINTK("%s", info->nodename);
+
+ /* Match the info->nodename path, or any subdirectory of that path. */
+ if (strncmp(xendev->nodename, info->nodename, len))
+ return 0;
+
+ /* If the node name is longer, ensure it really is a subdirectory. */
+ if ((strlen(xendev->nodename) > len) && (xendev->nodename[len] != '/'))
+ return 0;
+
+ info->dev = xendev;
+ get_device(dev);
+ return 1;
+}
+
+static void xenbus_cleanup_devices(const char *path, struct bus_type *bus)
+{
+ struct xb_find_info info = { .nodename = path };
+
+ do {
+ info.dev = NULL;
+ bus_for_each_dev(bus, NULL, &info, cleanup_dev);
+ if (info.dev) {
+ device_unregister(&info.dev->dev);
+ put_device(&info.dev->dev);
+ }
+ } while (info.dev);
+}
+
+static void xenbus_dev_release(struct device *dev)
+{
+ if (dev)
+ kfree(to_xenbus_device(dev));
+}
+
+/* Simplified asprintf. */
+char *kasprintf(const char *fmt, ...)
+{
+ va_list ap;
+ unsigned int len;
+ char *p, dummy[1];
+
+ va_start(ap, fmt);
+ /* FIXME: vsnprintf has a bug, NULL should work */
+ len = vsnprintf(dummy, 0, fmt, ap);
+ va_end(ap);
+
+ p = kmalloc(len + 1, GFP_KERNEL);
+ if (!p)
+ return NULL;
+ va_start(ap, fmt);
+ vsprintf(p, fmt, ap);
+ va_end(ap);
+ return p;
+}
+
+static ssize_t xendev_show_nodename(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%s\n", to_xenbus_device(dev)->nodename);
+}
+DEVICE_ATTR(nodename, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_nodename, NULL);
+
+static ssize_t xendev_show_devtype(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ return sprintf(buf, "%s\n", to_xenbus_device(dev)->devicetype);
+}
+DEVICE_ATTR(devtype, S_IRUSR | S_IRGRP | S_IROTH, xendev_show_devtype, NULL);
+
+
+static int xenbus_probe_node(struct xen_bus_type *bus,
+ const char *type,
+ const char *nodename)
+{
+ int err;
+ struct xenbus_device *xendev;
+ size_t stringlen;
+ char *tmpstring;
+
+ enum xenbus_state state = xenbus_read_driver_state(nodename);
+
+ if (state != XenbusStateInitialising) {
+ /* Device is not new, so ignore it. This can happen if a
+ device is going away after switching to Closed. */
+ return 0;
+ }
+
+ stringlen = strlen(nodename) + 1 + strlen(type) + 1;
+ xendev = kzalloc(sizeof(*xendev) + stringlen, GFP_KERNEL);
+ if (!xendev)
+ return -ENOMEM;
+
+ /* Copy the strings into the extra space. */
+
+ tmpstring = (char *)(xendev + 1);
+ strcpy(tmpstring, nodename);
+ xendev->nodename = tmpstring;
+
+ tmpstring += strlen(tmpstring) + 1;
+ strcpy(tmpstring, type);
+ xendev->devicetype = tmpstring;
+
+ xendev->dev.parent = &bus->dev;
+ xendev->dev.bus = &bus->bus;
+ xendev->dev.release = xenbus_dev_release;
+
+ err = bus->get_bus_id(xendev->dev.bus_id, xendev->nodename);
+ if (err)
+ goto fail;
+
+ /* Register with generic device framework. */
+ err = device_register(&xendev->dev);
+ if (err)
+ goto fail;
+
+ device_create_file(&xendev->dev, &dev_attr_nodename);
+ device_create_file(&xendev->dev, &dev_attr_devtype);
+
+ return 0;
+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("%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;
+}
+
+/* backend/<typename>/<frontend-uuid>/<name> */
+static int xenbus_probe_backend_unit(const char *dir,
+ const char *type,
+ const char *name)
+{
+ char *nodename;
+ int err;
+
+ nodename = kasprintf("%s/%s", dir, name);
+ if (!nodename)
+ return -ENOMEM;
+
+ DPRINTK("%s\n", nodename);
+
+ err = xenbus_probe_node(&xenbus_backend, type, nodename);
+ kfree(nodename);
+ return err;
+}
+
+/* backend/<typename>/<frontend-domid> */
+static int xenbus_probe_backend(const char *type, const char *domid)
+{
+ char *nodename;
+ int err = 0;
+ char **dir;
+ unsigned int i, dir_n = 0;
+
+ DPRINTK("");
+
+ nodename = kasprintf("%s/%s/%s", xenbus_backend.root, type, domid);
+ if (!nodename)
+ return -ENOMEM;
+
+ dir = xenbus_directory(XBT_NIL, nodename, "", &dir_n);
+ if (IS_ERR(dir)) {
+ kfree(nodename);
+ return PTR_ERR(dir);
+ }
+
+ for (i = 0; i < dir_n; i++) {
+ err = xenbus_probe_backend_unit(nodename, type, dir[i]);
+ if (err)
+ break;
+ }
+ kfree(dir);
+ 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;
+}
+
+static 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;
+}
+
+static void dev_changed(const char *node, struct xen_bus_type *bus)
+{
+ int exists, rootlen;
+ struct xenbus_device *dev;
+ char type[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, BUS_ID_SIZE, "%.*s", (int)strcspn(p, "/"), p);
+ type[BUS_ID_SIZE-1] = '\0';
+
+ rootlen = strsep_len(node, '/', bus->levels);
+ if (rootlen < 0)
+ return;
+ root = kasprintf("%.*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("");
+
+ dev_changed(vec[XS_WATCH_PATH], &xenbus_frontend);
+}
+
+static void backend_changed(struct xenbus_watch *watch,
+ const char **vec, unsigned int len)
+{
+ DPRINTK("");
+
+ dev_changed(vec[XS_WATCH_PATH], &xenbus_backend);
+}
+
+/* We watch for devices appearing and vanishing. */
+static struct xenbus_watch fe_watch = {
+ .node = "device",
+ .callback = frontend_changed,
+};
+
+static struct xenbus_watch be_watch = {
+ .node = "backend",
+ .callback = backend_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->bus_id, 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->bus_id, 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->bus_id, err);
+ return err;
+ }
+ }
+
+ err = watch_otherend(xdev);
+ if (err) {
+ printk(KERN_WARNING
+ "xenbus_probe: resume (watch_otherend) %s failed: "
+ "%d.\n", dev->bus_id, err);
+ return err;
+ }
+
+ return 0;
+}
+
+void xenbus_suspend(void)
+{
+ DPRINTK("");
+
+ bus_for_each_dev(&xenbus_frontend.bus, NULL, NULL, suspend_dev);
+ bus_for_each_dev(&xenbus_backend.bus, NULL, NULL, 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);
+ bus_for_each_dev(&xenbus_backend.bus, NULL, NULL, resume_dev);
+}
+EXPORT_SYMBOL_GPL(xenbus_resume);
+
+
+/* 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_notifier_list, nb);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(register_xenstore_notifier);
+
+void unregister_xenstore_notifier(struct notifier_block *nb)
+{
+ blocking_notifier_chain_unregister(&xenstore_notifier_list, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_xenstore_notifier);
+
+
+void xenbus_probe(void *unused)
+{
+ BUG_ON((xenstored_ready <= 0));
+
+ /* Enumerate devices in xenstore. */
+ xenbus_probe_devices(&xenbus_frontend);
+ xenbus_probe_devices(&xenbus_backend);
+
+ /* Watch for changes. */
+ register_xenbus_watch(&fe_watch);
+ register_xenbus_watch(&be_watch);
+
+ /* Notify others that xenstore is up */
+ blocking_notifier_call_chain(&xenstore_notifier_list, 0, NULL);
+}
+
+
+#ifdef CONFIG_PROC_FS
+static struct file_operations xsd_kva_fops;
+static struct proc_dir_entry *xsd_kva_intf;
+static struct proc_dir_entry *xsd_port_intf;
+
+static int xsd_kva_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ size_t size = vma->vm_end - vma->vm_start;
+
+ if ((size > PAGE_SIZE) || (vma->vm_pgoff != 0))
+ return -EINVAL;
+
+ if (remap_pfn_range(vma, vma->vm_start,
+ mfn_to_pfn(xen_start_info->store_mfn),
+ size, vma->vm_page_prot))
+ return -EAGAIN;
+
+ return 0;
+}
+
+static int xsd_kva_read(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ int len;
+
+ len = sprintf(page, "0x%p", mfn_to_virt(xen_start_info->store_mfn));
+ *eof = 1;
+ return len;
+}
+
+static int xsd_port_read(char *page, char **start, off_t off,
+ int count, int *eof, void *data)
+{
+ int len;
+
+ len = sprintf(page, "%d", xen_start_info->store_evtchn);
+ *eof = 1;
+ return len;
+}
+#endif
+
+
+static int __init xenbus_probe_init(void)
+{
+ int err = 0, dom0;
+ unsigned long page = 0;
+
+ DPRINTK("");
+
+ if (!is_running_on_xen())
+ return -ENODEV;
+
+ /* Register ourselves with the kernel bus subsystem */
+ bus_register(&xenbus_frontend.bus);
+ bus_register(&xenbus_backend.bus);
+
+ /*
+ * Domain0 doesn't have a store_evtchn or store_mfn yet.
+ */
+ dom0 = (xen_start_info->store_evtchn == 0);
+
+ if (dom0) {
+ struct evtchn_alloc_unbound alloc_unbound;
+
+ /* Allocate page. */
+ page = get_zeroed_page(GFP_KERNEL);
+ if (!page)
+ return -ENOMEM;
+
+ xen_start_info->store_mfn =
+ pfn_to_mfn(virt_to_phys((void *)page) >>
+ PAGE_SHIFT);
+
+ /* Next allocate a local port which xenstored can bind to */
+ alloc_unbound.dom = DOMID_SELF;
+ alloc_unbound.remote_dom = 0;
+
+ err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound,
+ &alloc_unbound);
+ if (err == -ENOSYS)
+ goto err;
+ BUG_ON(err);
+ xen_start_info->store_evtchn = alloc_unbound.port;
+
+#ifdef CONFIG_PROC_FS
+ /* And finally publish the above info in /proc/xen */
+ xsd_kva_intf = create_xen_proc_entry("xsd_kva", 0600);
+ if (xsd_kva_intf) {
+ memcpy(&xsd_kva_fops, xsd_kva_intf->proc_fops,
+ sizeof(xsd_kva_fops));
+ xsd_kva_fops.mmap = xsd_kva_mmap;
+ xsd_kva_intf->proc_fops = &xsd_kva_fops;
+ xsd_kva_intf->read_proc = xsd_kva_read;
+ }
+ xsd_port_intf = create_xen_proc_entry("xsd_port", 0400);
+ if (xsd_port_intf)
+ xsd_port_intf->read_proc = xsd_port_read;
+#endif
+ } else
+ xenstored_ready = 1;
+
+ /* Initialize the interface to xenstore. */
+ err = xs_init();
+ if (err) {
+ printk(KERN_WARNING
+ "XENBUS: Error initializing xenstore comms: %i\n", err);
+ goto err;
+ }
+
+ /* Register ourselves with the kernel device subsystem */
+ device_register(&xenbus_frontend.dev);
+ device_register(&xenbus_backend.dev);
+
+ if (!dom0)
+ xenbus_probe(NULL);
+
+ return 0;
+
+ err:
+ if (page)
+ free_page(page);
+
+ /*
+ * Do not unregister the xenbus front/backend buses here. The buses
+ * must exist because front/backend drivers will use them when they are
+ * registered.
+ */
+
+ return err;
+}
+
+postcore_initcall(xenbus_probe_init);
+
+
+static int is_disconnected_device(struct device *dev, void *data)
+{
+ struct xenbus_device *xendev = to_xenbus_device(dev);
+ struct device_driver *drv = data;
+
+ /*
+ * 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;
+
+ return (xendev->state != XenbusStateConnected);
+}
+
+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 || !is_running_on_xen())
+ 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);
+}
+
+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);
git://git.onelab.eu / linux-2.6.git / blobdiff