Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 1 | /****************************************************************************** |
| 2 | * Talks to Xen Store to figure out what devices we have (backend half). |
| 3 | * |
| 4 | * Copyright (C) 2005 Rusty Russell, IBM Corporation |
| 5 | * Copyright (C) 2005 Mike Wray, Hewlett-Packard |
| 6 | * Copyright (C) 2005, 2006 XenSource Ltd |
| 7 | * Copyright (C) 2007 Solarflare Communications, Inc. |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or |
| 10 | * modify it under the terms of the GNU General Public License version 2 |
| 11 | * as published by the Free Software Foundation; or, when distributed |
| 12 | * separately from the Linux kernel or incorporated into other |
| 13 | * software packages, subject to the following license: |
| 14 | * |
| 15 | * Permission is hereby granted, free of charge, to any person obtaining a copy |
| 16 | * of this source file (the "Software"), to deal in the Software without |
| 17 | * restriction, including without limitation the rights to use, copy, modify, |
| 18 | * merge, publish, distribute, sublicense, and/or sell copies of the Software, |
| 19 | * and to permit persons to whom the Software is furnished to do so, subject to |
| 20 | * the following conditions: |
| 21 | * |
| 22 | * The above copyright notice and this permission notice shall be included in |
| 23 | * all copies or substantial portions of the Software. |
| 24 | * |
| 25 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| 26 | * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| 27 | * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| 28 | * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| 29 | * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| 30 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS |
| 31 | * IN THE SOFTWARE. |
| 32 | */ |
| 33 | |
Joe Perches | 283c097 | 2013-06-28 03:21:41 -0700 | [diff] [blame^] | 34 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| 35 | |
| 36 | #define DPRINTK(fmt, ...) \ |
| 37 | pr_debug("(%s:%d) " fmt "\n", \ |
| 38 | __func__, __LINE__, ##__VA_ARGS__) |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 39 | |
| 40 | #include <linux/kernel.h> |
| 41 | #include <linux/err.h> |
| 42 | #include <linux/string.h> |
| 43 | #include <linux/ctype.h> |
| 44 | #include <linux/fcntl.h> |
| 45 | #include <linux/mm.h> |
| 46 | #include <linux/notifier.h> |
Paul Gortmaker | 63c9744 | 2011-07-10 13:22:07 -0400 | [diff] [blame] | 47 | #include <linux/export.h> |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 48 | |
| 49 | #include <asm/page.h> |
| 50 | #include <asm/pgtable.h> |
| 51 | #include <asm/xen/hypervisor.h> |
| 52 | #include <asm/hypervisor.h> |
| 53 | #include <xen/xenbus.h> |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 54 | #include <xen/features.h> |
| 55 | |
| 56 | #include "xenbus_comms.h" |
| 57 | #include "xenbus_probe.h" |
| 58 | |
| 59 | /* backend/<type>/<fe-uuid>/<id> => <type>-<fe-domid>-<id> */ |
| 60 | static int backend_bus_id(char bus_id[XEN_BUS_ID_SIZE], const char *nodename) |
| 61 | { |
| 62 | int domid, err; |
| 63 | const char *devid, *type, *frontend; |
| 64 | unsigned int typelen; |
| 65 | |
| 66 | type = strchr(nodename, '/'); |
| 67 | if (!type) |
| 68 | return -EINVAL; |
| 69 | type++; |
| 70 | typelen = strcspn(type, "/"); |
| 71 | if (!typelen || type[typelen] != '/') |
| 72 | return -EINVAL; |
| 73 | |
| 74 | devid = strrchr(nodename, '/') + 1; |
| 75 | |
| 76 | err = xenbus_gather(XBT_NIL, nodename, "frontend-id", "%i", &domid, |
| 77 | "frontend", NULL, &frontend, |
| 78 | NULL); |
| 79 | if (err) |
| 80 | return err; |
| 81 | if (strlen(frontend) == 0) |
| 82 | err = -ERANGE; |
| 83 | if (!err && !xenbus_exists(XBT_NIL, frontend, "")) |
| 84 | err = -ENOENT; |
| 85 | kfree(frontend); |
| 86 | |
| 87 | if (err) |
| 88 | return err; |
| 89 | |
Ian Campbell | 6bac7f9 | 2010-12-10 14:39:15 +0000 | [diff] [blame] | 90 | if (snprintf(bus_id, XEN_BUS_ID_SIZE, "%.*s-%i-%s", |
| 91 | typelen, type, domid, devid) >= XEN_BUS_ID_SIZE) |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 92 | return -ENOSPC; |
| 93 | return 0; |
| 94 | } |
| 95 | |
| 96 | static int xenbus_uevent_backend(struct device *dev, |
| 97 | struct kobj_uevent_env *env) |
| 98 | { |
| 99 | struct xenbus_device *xdev; |
| 100 | struct xenbus_driver *drv; |
| 101 | struct xen_bus_type *bus; |
| 102 | |
| 103 | DPRINTK(""); |
| 104 | |
| 105 | if (dev == NULL) |
| 106 | return -ENODEV; |
| 107 | |
| 108 | xdev = to_xenbus_device(dev); |
| 109 | bus = container_of(xdev->dev.bus, struct xen_bus_type, bus); |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 110 | |
Bastian Blank | 149bb2f | 2011-06-29 14:40:08 +0200 | [diff] [blame] | 111 | if (add_uevent_var(env, "MODALIAS=xen-backend:%s", xdev->devicetype)) |
| 112 | return -ENOMEM; |
| 113 | |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 114 | /* stuff we want to pass to /sbin/hotplug */ |
| 115 | if (add_uevent_var(env, "XENBUS_TYPE=%s", xdev->devicetype)) |
| 116 | return -ENOMEM; |
| 117 | |
| 118 | if (add_uevent_var(env, "XENBUS_PATH=%s", xdev->nodename)) |
| 119 | return -ENOMEM; |
| 120 | |
| 121 | if (add_uevent_var(env, "XENBUS_BASE_PATH=%s", bus->root)) |
| 122 | return -ENOMEM; |
| 123 | |
| 124 | if (dev->driver) { |
| 125 | drv = to_xenbus_driver(dev->driver); |
| 126 | if (drv && drv->uevent) |
| 127 | return drv->uevent(xdev, env); |
| 128 | } |
| 129 | |
| 130 | return 0; |
| 131 | } |
| 132 | |
| 133 | /* backend/<typename>/<frontend-uuid>/<name> */ |
| 134 | static int xenbus_probe_backend_unit(struct xen_bus_type *bus, |
| 135 | const char *dir, |
| 136 | const char *type, |
| 137 | const char *name) |
| 138 | { |
| 139 | char *nodename; |
| 140 | int err; |
| 141 | |
| 142 | nodename = kasprintf(GFP_KERNEL, "%s/%s", dir, name); |
| 143 | if (!nodename) |
| 144 | return -ENOMEM; |
| 145 | |
| 146 | DPRINTK("%s\n", nodename); |
| 147 | |
| 148 | err = xenbus_probe_node(bus, type, nodename); |
| 149 | kfree(nodename); |
| 150 | return err; |
| 151 | } |
| 152 | |
| 153 | /* backend/<typename>/<frontend-domid> */ |
Ian Campbell | 6bac7f9 | 2010-12-10 14:39:15 +0000 | [diff] [blame] | 154 | static int xenbus_probe_backend(struct xen_bus_type *bus, const char *type, |
| 155 | const char *domid) |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 156 | { |
| 157 | char *nodename; |
| 158 | int err = 0; |
| 159 | char **dir; |
| 160 | unsigned int i, dir_n = 0; |
| 161 | |
| 162 | DPRINTK(""); |
| 163 | |
| 164 | nodename = kasprintf(GFP_KERNEL, "%s/%s/%s", bus->root, type, domid); |
| 165 | if (!nodename) |
| 166 | return -ENOMEM; |
| 167 | |
| 168 | dir = xenbus_directory(XBT_NIL, nodename, "", &dir_n); |
| 169 | if (IS_ERR(dir)) { |
| 170 | kfree(nodename); |
| 171 | return PTR_ERR(dir); |
| 172 | } |
| 173 | |
| 174 | for (i = 0; i < dir_n; i++) { |
| 175 | err = xenbus_probe_backend_unit(bus, nodename, type, dir[i]); |
| 176 | if (err) |
| 177 | break; |
| 178 | } |
| 179 | kfree(dir); |
| 180 | kfree(nodename); |
| 181 | return err; |
| 182 | } |
| 183 | |
| 184 | static void frontend_changed(struct xenbus_watch *watch, |
| 185 | const char **vec, unsigned int len) |
| 186 | { |
| 187 | xenbus_otherend_changed(watch, vec, len, 0); |
| 188 | } |
| 189 | |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 190 | static struct xen_bus_type xenbus_backend = { |
| 191 | .root = "backend", |
Ian Campbell | 6bac7f9 | 2010-12-10 14:39:15 +0000 | [diff] [blame] | 192 | .levels = 3, /* backend/type/<frontend>/<id> */ |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 193 | .get_bus_id = backend_bus_id, |
| 194 | .probe = xenbus_probe_backend, |
| 195 | .otherend_changed = frontend_changed, |
| 196 | .bus = { |
Ian Campbell | 6bac7f9 | 2010-12-10 14:39:15 +0000 | [diff] [blame] | 197 | .name = "xen-backend", |
| 198 | .match = xenbus_match, |
| 199 | .uevent = xenbus_uevent_backend, |
| 200 | .probe = xenbus_dev_probe, |
| 201 | .remove = xenbus_dev_remove, |
| 202 | .shutdown = xenbus_dev_shutdown, |
Bastian Blank | cc85e93 | 2011-06-29 14:39:26 +0200 | [diff] [blame] | 203 | .dev_attrs = xenbus_dev_attrs, |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 204 | }, |
| 205 | }; |
| 206 | |
| 207 | static void backend_changed(struct xenbus_watch *watch, |
| 208 | const char **vec, unsigned int len) |
| 209 | { |
| 210 | DPRINTK(""); |
| 211 | |
| 212 | xenbus_dev_changed(vec[XS_WATCH_PATH], &xenbus_backend); |
| 213 | } |
| 214 | |
| 215 | static struct xenbus_watch be_watch = { |
| 216 | .node = "backend", |
| 217 | .callback = backend_changed, |
| 218 | }; |
| 219 | |
| 220 | static int read_frontend_details(struct xenbus_device *xendev) |
| 221 | { |
| 222 | return xenbus_read_otherend_details(xendev, "frontend-id", "frontend"); |
| 223 | } |
| 224 | |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 225 | int xenbus_dev_is_online(struct xenbus_device *dev) |
| 226 | { |
| 227 | int rc, val; |
| 228 | |
| 229 | rc = xenbus_scanf(XBT_NIL, dev->nodename, "online", "%d", &val); |
| 230 | if (rc != 1) |
| 231 | val = 0; /* no online node present */ |
| 232 | |
| 233 | return val; |
| 234 | } |
| 235 | EXPORT_SYMBOL_GPL(xenbus_dev_is_online); |
| 236 | |
Jan Beulich | 73db144 | 2011-12-22 09:08:13 +0000 | [diff] [blame] | 237 | int xenbus_register_backend(struct xenbus_driver *drv) |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 238 | { |
| 239 | drv->read_otherend_details = read_frontend_details; |
| 240 | |
Jan Beulich | 73db144 | 2011-12-22 09:08:13 +0000 | [diff] [blame] | 241 | return xenbus_register_driver_common(drv, &xenbus_backend); |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 242 | } |
Jan Beulich | 73db144 | 2011-12-22 09:08:13 +0000 | [diff] [blame] | 243 | EXPORT_SYMBOL_GPL(xenbus_register_backend); |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 244 | |
| 245 | static int backend_probe_and_watch(struct notifier_block *notifier, |
| 246 | unsigned long event, |
| 247 | void *data) |
| 248 | { |
| 249 | /* Enumerate devices in xenstore and watch for changes. */ |
| 250 | xenbus_probe_devices(&xenbus_backend); |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 251 | register_xenbus_watch(&be_watch); |
Jeremy Fitzhardinge | b5d33d0 | 2010-03-29 14:38:35 -0700 | [diff] [blame] | 252 | |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 253 | return NOTIFY_DONE; |
| 254 | } |
| 255 | |
| 256 | static int __init xenbus_probe_backend_init(void) |
| 257 | { |
| 258 | static struct notifier_block xenstore_notifier = { |
| 259 | .notifier_call = backend_probe_and_watch |
| 260 | }; |
| 261 | int err; |
| 262 | |
| 263 | DPRINTK(""); |
| 264 | |
| 265 | /* Register ourselves with the kernel bus subsystem */ |
| 266 | err = bus_register(&xenbus_backend.bus); |
Jeremy Fitzhardinge | b5d33d0 | 2010-03-29 14:38:35 -0700 | [diff] [blame] | 267 | if (err) |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 268 | return err; |
Ian Campbell | df66025 | 2009-02-09 12:05:51 -0800 | [diff] [blame] | 269 | |
| 270 | register_xenstore_notifier(&xenstore_notifier); |
| 271 | |
| 272 | return 0; |
| 273 | } |
Jeremy Fitzhardinge | c3676e8 | 2009-03-04 22:32:16 -0800 | [diff] [blame] | 274 | subsys_initcall(xenbus_probe_backend_init); |