| /****************************************************************************** |
| * 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 pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| #define dev_fmt pr_fmt |
| |
| #define DPRINTK(fmt, args...) \ |
| pr_debug("xenbus_probe (%s:%d) " fmt ".\n", \ |
| __func__, __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/proc_fs.h> |
| #include <linux/notifier.h> |
| #include <linux/kthread.h> |
| #include <linux/mutex.h> |
| #include <linux/io.h> |
| #include <linux/slab.h> |
| #include <linux/module.h> |
| |
| #include <asm/page.h> |
| #include <asm/xen/hypervisor.h> |
| |
| #include <xen/xen.h> |
| #include <xen/xenbus.h> |
| #include <xen/events.h> |
| #include <xen/xen-ops.h> |
| #include <xen/page.h> |
| |
| #include <xen/hvm.h> |
| |
| #include "xenbus.h" |
| |
| |
| int xen_store_evtchn; |
| EXPORT_SYMBOL_GPL(xen_store_evtchn); |
| |
| struct xenstore_domain_interface *xen_store_interface; |
| EXPORT_SYMBOL_GPL(xen_store_interface); |
| |
| enum xenstore_init xen_store_domain_type; |
| EXPORT_SYMBOL_GPL(xen_store_domain_type); |
| |
| static unsigned long xen_store_gfn; |
| |
| static BLOCKING_NOTIFIER_HEAD(xenstore_chain); |
| |
| /* 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; |
| } |
| |
| 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; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_match); |
| |
| |
| 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 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) |
| { |
| struct xen_bus_type *bus = |
| container_of(dev->dev.bus, struct xen_bus_type, bus); |
| |
| return xenbus_watch_pathfmt(dev, &dev->otherend_watch, |
| bus->otherend_will_handle, |
| bus->otherend_changed, |
| "%s/%s", dev->otherend, "state"); |
| } |
| |
| |
| int xenbus_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; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_read_otherend_details); |
| |
| void xenbus_otherend_changed(struct xenbus_watch *watch, |
| const char *path, const char *token, |
| int ignore_on_shutdown) |
| { |
| 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, path, strlen(dev->otherend))) { |
| dev_dbg(&dev->dev, "Ignoring watch at %s\n", path); |
| return; |
| } |
| |
| state = xenbus_read_driver_state(dev->otherend); |
| |
| dev_dbg(&dev->dev, "state is %d, (%s), %s, %s\n", |
| state, xenbus_strstate(state), dev->otherend_watch.node, path); |
| |
| /* |
| * Ignore xenbus transitions during shutdown. This prevents us doing |
| * work that can fail e.g., when the rootfs is gone. |
| */ |
| if (system_state > SYSTEM_RUNNING) { |
| if (ignore_on_shutdown && (state == XenbusStateClosing)) |
| xenbus_frontend_closed(dev); |
| return; |
| } |
| |
| if (drv->otherend_changed) |
| drv->otherend_changed(dev, state); |
| } |
| EXPORT_SYMBOL_GPL(xenbus_otherend_changed); |
| |
| #define XENBUS_SHOW_STAT(name) \ |
| static ssize_t name##_show(struct device *_dev, \ |
| struct device_attribute *attr, \ |
| char *buf) \ |
| { \ |
| struct xenbus_device *dev = to_xenbus_device(_dev); \ |
| \ |
| return sprintf(buf, "%d\n", atomic_read(&dev->name)); \ |
| } \ |
| static DEVICE_ATTR_RO(name) |
| |
| XENBUS_SHOW_STAT(event_channels); |
| XENBUS_SHOW_STAT(events); |
| XENBUS_SHOW_STAT(spurious_events); |
| XENBUS_SHOW_STAT(jiffies_eoi_delayed); |
| |
| static ssize_t spurious_threshold_show(struct device *_dev, |
| struct device_attribute *attr, |
| char *buf) |
| { |
| struct xenbus_device *dev = to_xenbus_device(_dev); |
| |
| return sprintf(buf, "%d\n", dev->spurious_threshold); |
| } |
| |
| static ssize_t spurious_threshold_store(struct device *_dev, |
| struct device_attribute *attr, |
| const char *buf, size_t count) |
| { |
| struct xenbus_device *dev = to_xenbus_device(_dev); |
| unsigned int val; |
| ssize_t ret; |
| |
| ret = kstrtouint(buf, 0, &val); |
| if (ret) |
| return ret; |
| |
| dev->spurious_threshold = val; |
| |
| return count; |
| } |
| |
| static DEVICE_ATTR_RW(spurious_threshold); |
| |
| static struct attribute *xenbus_attrs[] = { |
| &dev_attr_event_channels.attr, |
| &dev_attr_events.attr, |
| &dev_attr_spurious_events.attr, |
| &dev_attr_jiffies_eoi_delayed.attr, |
| &dev_attr_spurious_threshold.attr, |
| NULL |
| }; |
| |
| static const struct attribute_group xenbus_group = { |
| .name = "xenbus", |
| .attrs = xenbus_attrs, |
| }; |
| |
| 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("%s", dev->nodename); |
| |
| 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) { |
| dev_warn(&dev->dev, "talk_to_otherend on %s failed.\n", |
| dev->nodename); |
| return err; |
| } |
| |
| if (!try_module_get(drv->driver.owner)) { |
| dev_warn(&dev->dev, "failed to acquire module reference on '%s'\n", |
| drv->driver.name); |
| err = -ESRCH; |
| goto fail; |
| } |
| |
| down(&dev->reclaim_sem); |
| err = drv->probe(dev, id); |
| up(&dev->reclaim_sem); |
| if (err) |
| goto fail_put; |
| |
| err = watch_otherend(dev); |
| if (err) { |
| dev_warn(&dev->dev, "watch_otherend on %s failed.\n", |
| dev->nodename); |
| return err; |
| } |
| |
| dev->spurious_threshold = 1; |
| if (sysfs_create_group(&dev->dev.kobj, &xenbus_group)) |
| dev_warn(&dev->dev, "sysfs_create_group on %s failed.\n", |
| dev->nodename); |
| |
| return 0; |
| fail_put: |
| module_put(drv->driver.owner); |
| fail: |
| xenbus_dev_error(dev, err, "xenbus_dev_probe on %s", dev->nodename); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_dev_probe); |
| |
| void xenbus_dev_remove(struct device *_dev) |
| { |
| struct xenbus_device *dev = to_xenbus_device(_dev); |
| struct xenbus_driver *drv = to_xenbus_driver(_dev->driver); |
| |
| DPRINTK("%s", dev->nodename); |
| |
| sysfs_remove_group(&dev->dev.kobj, &xenbus_group); |
| |
| free_otherend_watch(dev); |
| |
| if (drv->remove) { |
| down(&dev->reclaim_sem); |
| drv->remove(dev); |
| up(&dev->reclaim_sem); |
| } |
| |
| module_put(drv->driver.owner); |
| |
| free_otherend_details(dev); |
| |
| /* |
| * If the toolstack has forced the device state to closing then set |
| * the state to closed now to allow it to be cleaned up. |
| * Similarly, if the driver does not support re-bind, set the |
| * closed. |
| */ |
| if (!drv->allow_rebind || |
| xenbus_read_driver_state(dev->nodename) == XenbusStateClosing) |
| xenbus_switch_state(dev, XenbusStateClosed); |
| } |
| EXPORT_SYMBOL_GPL(xenbus_dev_remove); |
| |
| int xenbus_register_driver_common(struct xenbus_driver *drv, |
| struct xen_bus_type *bus, |
| struct module *owner, const char *mod_name) |
| { |
| drv->driver.name = drv->name ? drv->name : drv->ids[0].devicetype; |
| drv->driver.bus = &bus->bus; |
| drv->driver.owner = owner; |
| drv->driver.mod_name = mod_name; |
| |
| return driver_register(&drv->driver); |
| } |
| EXPORT_SYMBOL_GPL(xenbus_register_driver_common); |
| |
| 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; |
| } |
| |
| static 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)); |
| } |
| |
| static ssize_t nodename_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%s\n", to_xenbus_device(dev)->nodename); |
| } |
| static DEVICE_ATTR_RO(nodename); |
| |
| static ssize_t devtype_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%s\n", to_xenbus_device(dev)->devicetype); |
| } |
| static DEVICE_ATTR_RO(devtype); |
| |
| static ssize_t modalias_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%s:%s\n", dev->bus->name, |
| to_xenbus_device(dev)->devicetype); |
| } |
| static DEVICE_ATTR_RO(modalias); |
| |
| static ssize_t state_show(struct device *dev, |
| struct device_attribute *attr, char *buf) |
| { |
| return sprintf(buf, "%s\n", |
| xenbus_strstate(to_xenbus_device(dev)->state)); |
| } |
| static DEVICE_ATTR_RO(state); |
| |
| static struct attribute *xenbus_dev_attrs[] = { |
| &dev_attr_nodename.attr, |
| &dev_attr_devtype.attr, |
| &dev_attr_modalias.attr, |
| &dev_attr_state.attr, |
| NULL, |
| }; |
| |
| static const struct attribute_group xenbus_dev_group = { |
| .attrs = xenbus_dev_attrs, |
| }; |
| |
| const struct attribute_group *xenbus_dev_groups[] = { |
| &xenbus_dev_group, |
| NULL, |
| }; |
| EXPORT_SYMBOL_GPL(xenbus_dev_groups); |
| |
| int xenbus_probe_node(struct xen_bus_type *bus, |
| const char *type, |
| const char *nodename) |
| { |
| char devname[XEN_BUS_ID_SIZE]; |
| 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; |
| |
| xendev->state = XenbusStateInitialising; |
| |
| /* 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; |
| init_completion(&xendev->down); |
| |
| xendev->dev.bus = &bus->bus; |
| xendev->dev.release = xenbus_dev_release; |
| |
| err = bus->get_bus_id(devname, xendev->nodename); |
| if (err) |
| goto fail; |
| |
| dev_set_name(&xendev->dev, "%s", devname); |
| sema_init(&xendev->reclaim_sem, 1); |
| |
| /* Register with generic device framework. */ |
| err = device_register(&xendev->dev); |
| if (err) { |
| put_device(&xendev->dev); |
| xendev = NULL; |
| goto fail; |
| } |
| |
| return 0; |
| fail: |
| kfree(xendev); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_probe_node); |
| |
| 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(bus, 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; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_probe_devices); |
| |
| 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); |
| } |
| EXPORT_SYMBOL_GPL(xenbus_dev_changed); |
| |
| int xenbus_dev_suspend(struct device *dev) |
| { |
| int err = 0; |
| struct xenbus_driver *drv; |
| struct xenbus_device *xdev |
| = container_of(dev, struct xenbus_device, dev); |
| |
| DPRINTK("%s", xdev->nodename); |
| |
| if (dev->driver == NULL) |
| return 0; |
| drv = to_xenbus_driver(dev->driver); |
| if (drv->suspend) |
| err = drv->suspend(xdev); |
| if (err) |
| dev_warn(dev, "suspend failed: %i\n", err); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_dev_suspend); |
| |
| int xenbus_dev_resume(struct device *dev) |
| { |
| int err; |
| struct xenbus_driver *drv; |
| struct xenbus_device *xdev |
| = container_of(dev, struct xenbus_device, dev); |
| |
| DPRINTK("%s", xdev->nodename); |
| |
| if (dev->driver == NULL) |
| return 0; |
| drv = to_xenbus_driver(dev->driver); |
| err = talk_to_otherend(xdev); |
| if (err) { |
| dev_warn(dev, "resume (talk_to_otherend) failed: %i\n", err); |
| return err; |
| } |
| |
| xdev->state = XenbusStateInitialising; |
| |
| if (drv->resume) { |
| err = drv->resume(xdev); |
| if (err) { |
| dev_warn(dev, "resume failed: %i\n", err); |
| return err; |
| } |
| } |
| |
| err = watch_otherend(xdev); |
| if (err) { |
| dev_warn(dev, "resume (watch_otherend) failed: %d\n", err); |
| return err; |
| } |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_dev_resume); |
| |
| int xenbus_dev_cancel(struct device *dev) |
| { |
| /* Do nothing */ |
| DPRINTK("cancel"); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(xenbus_dev_cancel); |
| |
| /* A flag to determine if xenstored is 'ready' (i.e. has started) */ |
| int xenstored_ready; |
| |
| |
| 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); |
| |
| static void xenbus_probe(void) |
| { |
| xenstored_ready = 1; |
| |
| /* |
| * In the HVM case, xenbus_init() deferred its call to |
| * xs_init() in case callbacks were not operational yet. |
| * So do it now. |
| */ |
| if (xen_store_domain_type == XS_HVM) |
| xs_init(); |
| |
| /* Notify others that xenstore is up */ |
| blocking_notifier_call_chain(&xenstore_chain, 0, NULL); |
| } |
| |
| /* |
| * Returns true when XenStore init must be deferred in order to |
| * allow the PCI platform device to be initialised, before we |
| * can actually have event channel interrupts working. |
| */ |
| static bool xs_hvm_defer_init_for_callback(void) |
| { |
| #ifdef CONFIG_XEN_PVHVM |
| return xen_store_domain_type == XS_HVM && |
| !xen_have_vector_callback; |
| #else |
| return false; |
| #endif |
| } |
| |
| static int xenbus_probe_thread(void *unused) |
| { |
| DEFINE_WAIT(w); |
| |
| /* |
| * We actually just want to wait for *any* trigger of xb_waitq, |
| * and run xenbus_probe() the moment it occurs. |
| */ |
| prepare_to_wait(&xb_waitq, &w, TASK_INTERRUPTIBLE); |
| schedule(); |
| finish_wait(&xb_waitq, &w); |
| |
| DPRINTK("probing"); |
| xenbus_probe(); |
| return 0; |
| } |
| |
| static int __init xenbus_probe_initcall(void) |
| { |
| /* |
| * Probe XenBus here in the XS_PV case, and also XS_HVM unless we |
| * need to wait for the platform PCI device to come up. |
| */ |
| if (xen_store_domain_type == XS_PV || |
| (xen_store_domain_type == XS_HVM && |
| !xs_hvm_defer_init_for_callback())) |
| xenbus_probe(); |
| |
| /* |
| * For XS_LOCAL, spawn a thread which will wait for xenstored |
| * or a xenstore-stubdom to be started, then probe. It will be |
| * triggered when communication starts happening, by waiting |
| * on xb_waitq. |
| */ |
| if (xen_store_domain_type == XS_LOCAL) { |
| struct task_struct *probe_task; |
| |
| probe_task = kthread_run(xenbus_probe_thread, NULL, |
| "xenbus_probe"); |
| if (IS_ERR(probe_task)) |
| return PTR_ERR(probe_task); |
| } |
| return 0; |
| } |
| device_initcall(xenbus_probe_initcall); |
| |
| int xen_set_callback_via(uint64_t via) |
| { |
| struct xen_hvm_param a; |
| int ret; |
| |
| a.domid = DOMID_SELF; |
| a.index = HVM_PARAM_CALLBACK_IRQ; |
| a.value = via; |
| |
| ret = HYPERVISOR_hvm_op(HVMOP_set_param, &a); |
| if (ret) |
| return ret; |
| |
| /* |
| * If xenbus_probe_initcall() deferred the xenbus_probe() |
| * due to the callback not functioning yet, we can do it now. |
| */ |
| if (!xenstored_ready && xs_hvm_defer_init_for_callback()) |
| xenbus_probe(); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(xen_set_callback_via); |
| |
| /* Set up event channel for xenstored which is run as a local process |
| * (this is normally used only in dom0) |
| */ |
| static int __init xenstored_local_init(void) |
| { |
| int err = -ENOMEM; |
| unsigned long page = 0; |
| struct evtchn_alloc_unbound alloc_unbound; |
| |
| /* Allocate Xenstore page */ |
| page = get_zeroed_page(GFP_KERNEL); |
| if (!page) |
| goto out_err; |
| |
| xen_store_gfn = virt_to_gfn((void *)page); |
| |
| /* Next allocate a local port which xenstored can bind to */ |
| alloc_unbound.dom = DOMID_SELF; |
| alloc_unbound.remote_dom = DOMID_SELF; |
| |
| err = HYPERVISOR_event_channel_op(EVTCHNOP_alloc_unbound, |
| &alloc_unbound); |
| if (err == -ENOSYS) |
| goto out_err; |
| |
| BUG_ON(err); |
| xen_store_evtchn = alloc_unbound.port; |
| |
| return 0; |
| |
| out_err: |
| if (page != 0) |
| free_page(page); |
| return err; |
| } |
| |
| static int xenbus_resume_cb(struct notifier_block *nb, |
| unsigned long action, void *data) |
| { |
| int err = 0; |
| |
| if (xen_hvm_domain()) { |
| uint64_t v = 0; |
| |
| err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v); |
| if (!err && v) |
| xen_store_evtchn = v; |
| else |
| pr_warn("Cannot update xenstore event channel: %d\n", |
| err); |
| } else |
| xen_store_evtchn = xen_start_info->store_evtchn; |
| |
| return err; |
| } |
| |
| static struct notifier_block xenbus_resume_nb = { |
| .notifier_call = xenbus_resume_cb, |
| }; |
| |
| static int __init xenbus_init(void) |
| { |
| int err = 0; |
| uint64_t v = 0; |
| xen_store_domain_type = XS_UNKNOWN; |
| |
| if (!xen_domain()) |
| return -ENODEV; |
| |
| xenbus_ring_ops_init(); |
| |
| if (xen_pv_domain()) |
| xen_store_domain_type = XS_PV; |
| if (xen_hvm_domain()) |
| xen_store_domain_type = XS_HVM; |
| if (xen_hvm_domain() && xen_initial_domain()) |
| xen_store_domain_type = XS_LOCAL; |
| if (xen_pv_domain() && !xen_start_info->store_evtchn) |
| xen_store_domain_type = XS_LOCAL; |
| if (xen_pv_domain() && xen_start_info->store_evtchn) |
| xenstored_ready = 1; |
| |
| switch (xen_store_domain_type) { |
| case XS_LOCAL: |
| err = xenstored_local_init(); |
| if (err) |
| goto out_error; |
| xen_store_interface = gfn_to_virt(xen_store_gfn); |
| break; |
| case XS_PV: |
| xen_store_evtchn = xen_start_info->store_evtchn; |
| xen_store_gfn = xen_start_info->store_mfn; |
| xen_store_interface = gfn_to_virt(xen_store_gfn); |
| break; |
| case XS_HVM: |
| err = hvm_get_parameter(HVM_PARAM_STORE_EVTCHN, &v); |
| if (err) |
| goto out_error; |
| xen_store_evtchn = (int)v; |
| err = hvm_get_parameter(HVM_PARAM_STORE_PFN, &v); |
| if (err) |
| goto out_error; |
| xen_store_gfn = (unsigned long)v; |
| xen_store_interface = |
| xen_remap(xen_store_gfn << XEN_PAGE_SHIFT, |
| XEN_PAGE_SIZE); |
| break; |
| default: |
| pr_warn("Xenstore state unknown\n"); |
| break; |
| } |
| |
| /* |
| * HVM domains may not have a functional callback yet. In that |
| * case let xs_init() be called from xenbus_probe(), which will |
| * get invoked at an appropriate time. |
| */ |
| if (xen_store_domain_type != XS_HVM) { |
| err = xs_init(); |
| if (err) { |
| pr_warn("Error initializing xenstore comms: %i\n", err); |
| goto out_error; |
| } |
| } |
| |
| if ((xen_store_domain_type != XS_LOCAL) && |
| (xen_store_domain_type != XS_UNKNOWN)) |
| xen_resume_notifier_register(&xenbus_resume_nb); |
| |
| #ifdef CONFIG_XEN_COMPAT_XENFS |
| /* |
| * Create xenfs mountpoint in /proc for compatibility with |
| * utilities that expect to find "xenbus" under "/proc/xen". |
| */ |
| proc_create_mount_point("xen"); |
| #endif |
| |
| out_error: |
| return err; |
| } |
| |
| postcore_initcall(xenbus_init); |
| |
| MODULE_LICENSE("GPL"); |