1 /* 2 * Intel Management Engine Interface (Intel MEI) Linux driver 3 * Copyright (c) 2012-2013, Intel Corporation. 4 * 5 * This program is free software; you can redistribute it and/or modify it 6 * under the terms and conditions of the GNU General Public License, 7 * version 2, as published by the Free Software Foundation. 8 * 9 * This program is distributed in the hope it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 12 * more details. 13 * 14 */ 15 16 #include <linux/module.h> 17 #include <linux/device.h> 18 #include <linux/kernel.h> 19 #include <linux/sched.h> 20 #include <linux/init.h> 21 #include <linux/errno.h> 22 #include <linux/slab.h> 23 #include <linux/mutex.h> 24 #include <linux/interrupt.h> 25 #include <linux/mei_cl_bus.h> 26 27 #include "mei_dev.h" 28 #include "client.h" 29 30 #define to_mei_cl_driver(d) container_of(d, struct mei_cl_driver, driver) 31 #define to_mei_cl_device(d) container_of(d, struct mei_cl_device, dev) 32 33 static int mei_cl_device_match(struct device *dev, struct device_driver *drv) 34 { 35 struct mei_cl_device *device = to_mei_cl_device(dev); 36 struct mei_cl_driver *driver = to_mei_cl_driver(drv); 37 const struct mei_cl_device_id *id; 38 39 if (!device) 40 return 0; 41 42 if (!driver || !driver->id_table) 43 return 0; 44 45 id = driver->id_table; 46 47 while (id->name[0]) { 48 if (!strncmp(dev_name(dev), id->name, sizeof(id->name))) 49 return 1; 50 51 id++; 52 } 53 54 return 0; 55 } 56 57 static int mei_cl_device_probe(struct device *dev) 58 { 59 struct mei_cl_device *device = to_mei_cl_device(dev); 60 struct mei_cl_driver *driver; 61 struct mei_cl_device_id id; 62 63 if (!device) 64 return 0; 65 66 driver = to_mei_cl_driver(dev->driver); 67 if (!driver || !driver->probe) 68 return -ENODEV; 69 70 dev_dbg(dev, "Device probe\n"); 71 72 strlcpy(id.name, dev_name(dev), sizeof(id.name)); 73 74 return driver->probe(device, &id); 75 } 76 77 static int mei_cl_device_remove(struct device *dev) 78 { 79 struct mei_cl_device *device = to_mei_cl_device(dev); 80 struct mei_cl_driver *driver; 81 82 if (!device || !dev->driver) 83 return 0; 84 85 if (device->event_cb) { 86 device->event_cb = NULL; 87 cancel_work_sync(&device->event_work); 88 } 89 90 driver = to_mei_cl_driver(dev->driver); 91 if (!driver->remove) { 92 dev->driver = NULL; 93 94 return 0; 95 } 96 97 return driver->remove(device); 98 } 99 100 static ssize_t modalias_show(struct device *dev, struct device_attribute *a, 101 char *buf) 102 { 103 int len; 104 105 len = snprintf(buf, PAGE_SIZE, "mei:%s\n", dev_name(dev)); 106 107 return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len; 108 } 109 static DEVICE_ATTR_RO(modalias); 110 111 static struct attribute *mei_cl_dev_attrs[] = { 112 &dev_attr_modalias.attr, 113 NULL, 114 }; 115 ATTRIBUTE_GROUPS(mei_cl_dev); 116 117 static int mei_cl_uevent(struct device *dev, struct kobj_uevent_env *env) 118 { 119 if (add_uevent_var(env, "MODALIAS=mei:%s", dev_name(dev))) 120 return -ENOMEM; 121 122 return 0; 123 } 124 125 static struct bus_type mei_cl_bus_type = { 126 .name = "mei", 127 .dev_groups = mei_cl_dev_groups, 128 .match = mei_cl_device_match, 129 .probe = mei_cl_device_probe, 130 .remove = mei_cl_device_remove, 131 .uevent = mei_cl_uevent, 132 }; 133 134 static void mei_cl_dev_release(struct device *dev) 135 { 136 kfree(to_mei_cl_device(dev)); 137 } 138 139 static struct device_type mei_cl_device_type = { 140 .release = mei_cl_dev_release, 141 }; 142 143 struct mei_cl *mei_cl_bus_find_cl_by_uuid(struct mei_device *dev, 144 uuid_le uuid) 145 { 146 struct mei_cl *cl; 147 148 list_for_each_entry(cl, &dev->device_list, device_link) { 149 if (!uuid_le_cmp(uuid, cl->cl_uuid)) 150 return cl; 151 } 152 153 return NULL; 154 } 155 struct mei_cl_device *mei_cl_add_device(struct mei_device *dev, 156 uuid_le uuid, char *name, 157 struct mei_cl_ops *ops) 158 { 159 struct mei_cl_device *device; 160 struct mei_cl *cl; 161 int status; 162 163 cl = mei_cl_bus_find_cl_by_uuid(dev, uuid); 164 if (cl == NULL) 165 return NULL; 166 167 device = kzalloc(sizeof(struct mei_cl_device), GFP_KERNEL); 168 if (!device) 169 return NULL; 170 171 device->cl = cl; 172 device->ops = ops; 173 174 device->dev.parent = dev->dev; 175 device->dev.bus = &mei_cl_bus_type; 176 device->dev.type = &mei_cl_device_type; 177 178 dev_set_name(&device->dev, "%s", name); 179 180 status = device_register(&device->dev); 181 if (status) { 182 dev_err(dev->dev, "Failed to register MEI device\n"); 183 kfree(device); 184 return NULL; 185 } 186 187 cl->device = device; 188 189 dev_dbg(&device->dev, "client %s registered\n", name); 190 191 return device; 192 } 193 EXPORT_SYMBOL_GPL(mei_cl_add_device); 194 195 void mei_cl_remove_device(struct mei_cl_device *device) 196 { 197 device_unregister(&device->dev); 198 } 199 EXPORT_SYMBOL_GPL(mei_cl_remove_device); 200 201 int __mei_cl_driver_register(struct mei_cl_driver *driver, struct module *owner) 202 { 203 int err; 204 205 driver->driver.name = driver->name; 206 driver->driver.owner = owner; 207 driver->driver.bus = &mei_cl_bus_type; 208 209 err = driver_register(&driver->driver); 210 if (err) 211 return err; 212 213 pr_debug("mei: driver [%s] registered\n", driver->driver.name); 214 215 return 0; 216 } 217 EXPORT_SYMBOL_GPL(__mei_cl_driver_register); 218 219 void mei_cl_driver_unregister(struct mei_cl_driver *driver) 220 { 221 driver_unregister(&driver->driver); 222 223 pr_debug("mei: driver [%s] unregistered\n", driver->driver.name); 224 } 225 EXPORT_SYMBOL_GPL(mei_cl_driver_unregister); 226 227 static ssize_t ___mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length, 228 bool blocking) 229 { 230 struct mei_device *dev; 231 struct mei_me_client *me_cl = NULL; 232 struct mei_cl_cb *cb = NULL; 233 ssize_t rets; 234 235 if (WARN_ON(!cl || !cl->dev)) 236 return -ENODEV; 237 238 dev = cl->dev; 239 240 mutex_lock(&dev->device_lock); 241 if (!mei_cl_is_connected(cl)) { 242 rets = -ENODEV; 243 goto out; 244 } 245 246 /* Check if we have an ME client device */ 247 me_cl = mei_me_cl_by_uuid_id(dev, &cl->cl_uuid, cl->me_client_id); 248 if (!me_cl) { 249 rets = -ENOTTY; 250 goto out; 251 } 252 253 if (length > me_cl->props.max_msg_length) { 254 rets = -EFBIG; 255 goto out; 256 } 257 258 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, NULL); 259 if (!cb) { 260 rets = -ENOMEM; 261 goto out; 262 } 263 264 memcpy(cb->buf.data, buf, length); 265 266 rets = mei_cl_write(cl, cb, blocking); 267 268 out: 269 mei_me_cl_put(me_cl); 270 mutex_unlock(&dev->device_lock); 271 if (rets < 0) 272 mei_io_cb_free(cb); 273 274 return rets; 275 } 276 277 ssize_t __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length) 278 { 279 struct mei_device *dev; 280 struct mei_cl_cb *cb; 281 size_t r_length; 282 ssize_t rets; 283 284 if (WARN_ON(!cl || !cl->dev)) 285 return -ENODEV; 286 287 dev = cl->dev; 288 289 mutex_lock(&dev->device_lock); 290 291 cb = mei_cl_read_cb(cl, NULL); 292 if (cb) 293 goto copy; 294 295 rets = mei_cl_read_start(cl, length, NULL); 296 if (rets && rets != -EBUSY) 297 goto out; 298 299 if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) { 300 301 mutex_unlock(&dev->device_lock); 302 303 if (wait_event_interruptible(cl->rx_wait, 304 (!list_empty(&cl->rd_completed)) || 305 (!mei_cl_is_connected(cl)))) { 306 307 if (signal_pending(current)) 308 return -EINTR; 309 return -ERESTARTSYS; 310 } 311 312 mutex_lock(&dev->device_lock); 313 314 if (!mei_cl_is_connected(cl)) { 315 rets = -EBUSY; 316 goto out; 317 } 318 } 319 320 cb = mei_cl_read_cb(cl, NULL); 321 if (!cb) { 322 rets = 0; 323 goto out; 324 } 325 326 copy: 327 if (cb->status) { 328 rets = cb->status; 329 goto free; 330 } 331 332 r_length = min_t(size_t, length, cb->buf_idx); 333 memcpy(buf, cb->buf.data, r_length); 334 rets = r_length; 335 336 free: 337 mei_io_cb_free(cb); 338 out: 339 mutex_unlock(&dev->device_lock); 340 341 return rets; 342 } 343 344 inline ssize_t __mei_cl_async_send(struct mei_cl *cl, u8 *buf, size_t length) 345 { 346 return ___mei_cl_send(cl, buf, length, 0); 347 } 348 349 inline ssize_t __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length) 350 { 351 return ___mei_cl_send(cl, buf, length, 1); 352 } 353 354 ssize_t mei_cl_send(struct mei_cl_device *device, u8 *buf, size_t length) 355 { 356 struct mei_cl *cl = device->cl; 357 358 if (cl == NULL) 359 return -ENODEV; 360 361 if (device->ops && device->ops->send) 362 return device->ops->send(device, buf, length); 363 364 return __mei_cl_send(cl, buf, length); 365 } 366 EXPORT_SYMBOL_GPL(mei_cl_send); 367 368 ssize_t mei_cl_recv(struct mei_cl_device *device, u8 *buf, size_t length) 369 { 370 struct mei_cl *cl = device->cl; 371 372 if (cl == NULL) 373 return -ENODEV; 374 375 if (device->ops && device->ops->recv) 376 return device->ops->recv(device, buf, length); 377 378 return __mei_cl_recv(cl, buf, length); 379 } 380 EXPORT_SYMBOL_GPL(mei_cl_recv); 381 382 static void mei_bus_event_work(struct work_struct *work) 383 { 384 struct mei_cl_device *device; 385 386 device = container_of(work, struct mei_cl_device, event_work); 387 388 if (device->event_cb) 389 device->event_cb(device, device->events, device->event_context); 390 391 device->events = 0; 392 393 /* Prepare for the next read */ 394 mei_cl_read_start(device->cl, 0, NULL); 395 } 396 397 int mei_cl_register_event_cb(struct mei_cl_device *device, 398 mei_cl_event_cb_t event_cb, void *context) 399 { 400 if (device->event_cb) 401 return -EALREADY; 402 403 device->events = 0; 404 device->event_cb = event_cb; 405 device->event_context = context; 406 INIT_WORK(&device->event_work, mei_bus_event_work); 407 408 mei_cl_read_start(device->cl, 0, NULL); 409 410 return 0; 411 } 412 EXPORT_SYMBOL_GPL(mei_cl_register_event_cb); 413 414 void *mei_cl_get_drvdata(const struct mei_cl_device *device) 415 { 416 return dev_get_drvdata(&device->dev); 417 } 418 EXPORT_SYMBOL_GPL(mei_cl_get_drvdata); 419 420 void mei_cl_set_drvdata(struct mei_cl_device *device, void *data) 421 { 422 dev_set_drvdata(&device->dev, data); 423 } 424 EXPORT_SYMBOL_GPL(mei_cl_set_drvdata); 425 426 int mei_cl_enable_device(struct mei_cl_device *device) 427 { 428 int err; 429 struct mei_device *dev; 430 struct mei_cl *cl = device->cl; 431 432 if (cl == NULL) 433 return -ENODEV; 434 435 dev = cl->dev; 436 437 mutex_lock(&dev->device_lock); 438 439 err = mei_cl_connect(cl, NULL); 440 if (err < 0) { 441 mutex_unlock(&dev->device_lock); 442 dev_err(dev->dev, "Could not connect to the ME client"); 443 444 return err; 445 } 446 447 mutex_unlock(&dev->device_lock); 448 449 if (device->event_cb) 450 mei_cl_read_start(device->cl, 0, NULL); 451 452 if (!device->ops || !device->ops->enable) 453 return 0; 454 455 return device->ops->enable(device); 456 } 457 EXPORT_SYMBOL_GPL(mei_cl_enable_device); 458 459 int mei_cl_disable_device(struct mei_cl_device *device) 460 { 461 int err; 462 struct mei_device *dev; 463 struct mei_cl *cl = device->cl; 464 465 if (cl == NULL) 466 return -ENODEV; 467 468 dev = cl->dev; 469 470 if (device->ops && device->ops->disable) 471 device->ops->disable(device); 472 473 device->event_cb = NULL; 474 475 mutex_lock(&dev->device_lock); 476 477 if (!mei_cl_is_connected(cl)) { 478 dev_err(dev->dev, "Already disconnected"); 479 err = 0; 480 goto out; 481 } 482 483 cl->state = MEI_FILE_DISCONNECTING; 484 485 err = mei_cl_disconnect(cl); 486 if (err < 0) { 487 dev_err(dev->dev, "Could not disconnect from the ME client"); 488 goto out; 489 } 490 491 /* Flush queues and remove any pending read */ 492 mei_cl_flush_queues(cl, NULL); 493 494 out: 495 mutex_unlock(&dev->device_lock); 496 return err; 497 498 } 499 EXPORT_SYMBOL_GPL(mei_cl_disable_device); 500 501 void mei_cl_bus_rx_event(struct mei_cl *cl) 502 { 503 struct mei_cl_device *device = cl->device; 504 505 if (!device || !device->event_cb) 506 return; 507 508 set_bit(MEI_CL_EVENT_RX, &device->events); 509 510 schedule_work(&device->event_work); 511 } 512 513 void mei_cl_bus_remove_devices(struct mei_device *dev) 514 { 515 struct mei_cl *cl, *next; 516 517 mutex_lock(&dev->device_lock); 518 list_for_each_entry_safe(cl, next, &dev->device_list, device_link) { 519 if (cl->device) 520 mei_cl_remove_device(cl->device); 521 522 list_del(&cl->device_link); 523 mei_cl_unlink(cl); 524 kfree(cl); 525 } 526 mutex_unlock(&dev->device_lock); 527 } 528 529 int __init mei_cl_bus_init(void) 530 { 531 return bus_register(&mei_cl_bus_type); 532 } 533 534 void __exit mei_cl_bus_exit(void) 535 { 536 bus_unregister(&mei_cl_bus_type); 537 } 538