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 int ___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; 232 struct mei_cl_cb *cb; 233 int rets; 234 235 if (WARN_ON(!cl || !cl->dev)) 236 return -ENODEV; 237 238 dev = cl->dev; 239 240 if (cl->state != MEI_FILE_CONNECTED) 241 return -ENODEV; 242 243 /* Check if we have an ME client device */ 244 me_cl = mei_me_cl_by_uuid_id(dev, &cl->cl_uuid, cl->me_client_id); 245 if (!me_cl) 246 return -ENOTTY; 247 248 if (length > me_cl->props.max_msg_length) 249 return -EFBIG; 250 251 cb = mei_io_cb_init(cl, NULL); 252 if (!cb) 253 return -ENOMEM; 254 255 rets = mei_io_cb_alloc_req_buf(cb, length); 256 if (rets < 0) { 257 mei_io_cb_free(cb); 258 return rets; 259 } 260 261 memcpy(cb->request_buffer.data, buf, length); 262 263 mutex_lock(&dev->device_lock); 264 265 rets = mei_cl_write(cl, cb, blocking); 266 267 mutex_unlock(&dev->device_lock); 268 if (rets < 0) 269 mei_io_cb_free(cb); 270 271 return rets; 272 } 273 274 int __mei_cl_recv(struct mei_cl *cl, u8 *buf, size_t length) 275 { 276 struct mei_device *dev; 277 struct mei_cl_cb *cb; 278 size_t r_length; 279 int err; 280 281 if (WARN_ON(!cl || !cl->dev)) 282 return -ENODEV; 283 284 dev = cl->dev; 285 286 mutex_lock(&dev->device_lock); 287 288 if (!cl->read_cb) { 289 err = mei_cl_read_start(cl, length); 290 if (err < 0) { 291 mutex_unlock(&dev->device_lock); 292 return err; 293 } 294 } 295 296 if (cl->reading_state != MEI_READ_COMPLETE && 297 !waitqueue_active(&cl->rx_wait)) { 298 299 mutex_unlock(&dev->device_lock); 300 301 if (wait_event_interruptible(cl->rx_wait, 302 cl->reading_state == MEI_READ_COMPLETE || 303 mei_cl_is_transitioning(cl))) { 304 305 if (signal_pending(current)) 306 return -EINTR; 307 return -ERESTARTSYS; 308 } 309 310 mutex_lock(&dev->device_lock); 311 } 312 313 cb = cl->read_cb; 314 315 if (cl->reading_state != MEI_READ_COMPLETE) { 316 r_length = 0; 317 goto out; 318 } 319 320 r_length = min_t(size_t, length, cb->buf_idx); 321 322 memcpy(buf, cb->response_buffer.data, r_length); 323 324 mei_io_cb_free(cb); 325 cl->reading_state = MEI_IDLE; 326 cl->read_cb = NULL; 327 328 out: 329 mutex_unlock(&dev->device_lock); 330 331 return r_length; 332 } 333 334 inline int __mei_cl_async_send(struct mei_cl *cl, u8 *buf, size_t length) 335 { 336 return ___mei_cl_send(cl, buf, length, 0); 337 } 338 339 inline int __mei_cl_send(struct mei_cl *cl, u8 *buf, size_t length) 340 { 341 return ___mei_cl_send(cl, buf, length, 1); 342 } 343 344 int mei_cl_send(struct mei_cl_device *device, u8 *buf, size_t length) 345 { 346 struct mei_cl *cl = device->cl; 347 348 if (cl == NULL) 349 return -ENODEV; 350 351 if (device->ops && device->ops->send) 352 return device->ops->send(device, buf, length); 353 354 return __mei_cl_send(cl, buf, length); 355 } 356 EXPORT_SYMBOL_GPL(mei_cl_send); 357 358 int mei_cl_recv(struct mei_cl_device *device, u8 *buf, size_t length) 359 { 360 struct mei_cl *cl = device->cl; 361 362 if (cl == NULL) 363 return -ENODEV; 364 365 if (device->ops && device->ops->recv) 366 return device->ops->recv(device, buf, length); 367 368 return __mei_cl_recv(cl, buf, length); 369 } 370 EXPORT_SYMBOL_GPL(mei_cl_recv); 371 372 static void mei_bus_event_work(struct work_struct *work) 373 { 374 struct mei_cl_device *device; 375 376 device = container_of(work, struct mei_cl_device, event_work); 377 378 if (device->event_cb) 379 device->event_cb(device, device->events, device->event_context); 380 381 device->events = 0; 382 383 /* Prepare for the next read */ 384 mei_cl_read_start(device->cl, 0); 385 } 386 387 int mei_cl_register_event_cb(struct mei_cl_device *device, 388 mei_cl_event_cb_t event_cb, void *context) 389 { 390 if (device->event_cb) 391 return -EALREADY; 392 393 device->events = 0; 394 device->event_cb = event_cb; 395 device->event_context = context; 396 INIT_WORK(&device->event_work, mei_bus_event_work); 397 398 mei_cl_read_start(device->cl, 0); 399 400 return 0; 401 } 402 EXPORT_SYMBOL_GPL(mei_cl_register_event_cb); 403 404 void *mei_cl_get_drvdata(const struct mei_cl_device *device) 405 { 406 return dev_get_drvdata(&device->dev); 407 } 408 EXPORT_SYMBOL_GPL(mei_cl_get_drvdata); 409 410 void mei_cl_set_drvdata(struct mei_cl_device *device, void *data) 411 { 412 dev_set_drvdata(&device->dev, data); 413 } 414 EXPORT_SYMBOL_GPL(mei_cl_set_drvdata); 415 416 int mei_cl_enable_device(struct mei_cl_device *device) 417 { 418 int err; 419 struct mei_device *dev; 420 struct mei_cl *cl = device->cl; 421 422 if (cl == NULL) 423 return -ENODEV; 424 425 dev = cl->dev; 426 427 mutex_lock(&dev->device_lock); 428 429 err = mei_cl_connect(cl, NULL); 430 if (err < 0) { 431 mutex_unlock(&dev->device_lock); 432 dev_err(dev->dev, "Could not connect to the ME client"); 433 434 return err; 435 } 436 437 mutex_unlock(&dev->device_lock); 438 439 if (device->event_cb && !cl->read_cb) 440 mei_cl_read_start(device->cl, 0); 441 442 if (!device->ops || !device->ops->enable) 443 return 0; 444 445 return device->ops->enable(device); 446 } 447 EXPORT_SYMBOL_GPL(mei_cl_enable_device); 448 449 int mei_cl_disable_device(struct mei_cl_device *device) 450 { 451 int err; 452 struct mei_device *dev; 453 struct mei_cl *cl = device->cl; 454 455 if (cl == NULL) 456 return -ENODEV; 457 458 dev = cl->dev; 459 460 mutex_lock(&dev->device_lock); 461 462 if (cl->state != MEI_FILE_CONNECTED) { 463 mutex_unlock(&dev->device_lock); 464 dev_err(dev->dev, "Already disconnected"); 465 466 return 0; 467 } 468 469 cl->state = MEI_FILE_DISCONNECTING; 470 471 err = mei_cl_disconnect(cl); 472 if (err < 0) { 473 mutex_unlock(&dev->device_lock); 474 dev_err(dev->dev, 475 "Could not disconnect from the ME client"); 476 477 return err; 478 } 479 480 /* Flush queues and remove any pending read */ 481 mei_cl_flush_queues(cl); 482 483 if (cl->read_cb) { 484 struct mei_cl_cb *cb = NULL; 485 486 cb = mei_cl_find_read_cb(cl); 487 /* Remove entry from read list */ 488 if (cb) 489 list_del(&cb->list); 490 491 cb = cl->read_cb; 492 cl->read_cb = NULL; 493 494 if (cb) { 495 mei_io_cb_free(cb); 496 cb = NULL; 497 } 498 } 499 500 device->event_cb = NULL; 501 502 mutex_unlock(&dev->device_lock); 503 504 if (!device->ops || !device->ops->disable) 505 return 0; 506 507 return device->ops->disable(device); 508 } 509 EXPORT_SYMBOL_GPL(mei_cl_disable_device); 510 511 void mei_cl_bus_rx_event(struct mei_cl *cl) 512 { 513 struct mei_cl_device *device = cl->device; 514 515 if (!device || !device->event_cb) 516 return; 517 518 set_bit(MEI_CL_EVENT_RX, &device->events); 519 520 schedule_work(&device->event_work); 521 } 522 523 void mei_cl_bus_remove_devices(struct mei_device *dev) 524 { 525 struct mei_cl *cl, *next; 526 527 mutex_lock(&dev->device_lock); 528 list_for_each_entry_safe(cl, next, &dev->device_list, device_link) { 529 if (cl->device) 530 mei_cl_remove_device(cl->device); 531 532 list_del(&cl->device_link); 533 mei_cl_unlink(cl); 534 kfree(cl); 535 } 536 mutex_unlock(&dev->device_lock); 537 } 538 539 int __init mei_cl_bus_init(void) 540 { 541 return bus_register(&mei_cl_bus_type); 542 } 543 544 void __exit mei_cl_bus_exit(void) 545 { 546 bus_unregister(&mei_cl_bus_type); 547 } 548