1 /* 2 * 3 * Intel Management Engine Interface (Intel MEI) Linux driver 4 * Copyright (c) 2003-2012, Intel Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify it 7 * under the terms and conditions of the GNU General Public License, 8 * version 2, as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 13 * more details. 14 * 15 */ 16 #include <linux/module.h> 17 #include <linux/moduleparam.h> 18 #include <linux/kernel.h> 19 #include <linux/device.h> 20 #include <linux/slab.h> 21 #include <linux/fs.h> 22 #include <linux/errno.h> 23 #include <linux/types.h> 24 #include <linux/fcntl.h> 25 #include <linux/poll.h> 26 #include <linux/init.h> 27 #include <linux/ioctl.h> 28 #include <linux/cdev.h> 29 #include <linux/sched.h> 30 #include <linux/uuid.h> 31 #include <linux/compat.h> 32 #include <linux/jiffies.h> 33 #include <linux/interrupt.h> 34 35 #include <linux/mei.h> 36 37 #include "mei_dev.h" 38 #include "client.h" 39 40 /** 41 * mei_open - the open function 42 * 43 * @inode: pointer to inode structure 44 * @file: pointer to file structure 45 * 46 * Return: 0 on success, <0 on error 47 */ 48 static int mei_open(struct inode *inode, struct file *file) 49 { 50 struct mei_device *dev; 51 struct mei_cl *cl; 52 53 int err; 54 55 dev = container_of(inode->i_cdev, struct mei_device, cdev); 56 if (!dev) 57 return -ENODEV; 58 59 mutex_lock(&dev->device_lock); 60 61 if (dev->dev_state != MEI_DEV_ENABLED) { 62 dev_dbg(dev->dev, "dev_state != MEI_ENABLED dev_state = %s\n", 63 mei_dev_state_str(dev->dev_state)); 64 err = -ENODEV; 65 goto err_unlock; 66 } 67 68 cl = mei_cl_alloc_linked(dev); 69 if (IS_ERR(cl)) { 70 err = PTR_ERR(cl); 71 goto err_unlock; 72 } 73 74 file->private_data = cl; 75 76 mutex_unlock(&dev->device_lock); 77 78 return nonseekable_open(inode, file); 79 80 err_unlock: 81 mutex_unlock(&dev->device_lock); 82 return err; 83 } 84 85 /** 86 * mei_release - the release function 87 * 88 * @inode: pointer to inode structure 89 * @file: pointer to file structure 90 * 91 * Return: 0 on success, <0 on error 92 */ 93 static int mei_release(struct inode *inode, struct file *file) 94 { 95 struct mei_cl *cl = file->private_data; 96 struct mei_device *dev; 97 int rets; 98 99 if (WARN_ON(!cl || !cl->dev)) 100 return -ENODEV; 101 102 dev = cl->dev; 103 104 mutex_lock(&dev->device_lock); 105 if (cl == &dev->iamthif_cl) { 106 rets = mei_amthif_release(dev, file); 107 goto out; 108 } 109 rets = mei_cl_disconnect(cl); 110 111 mei_cl_flush_queues(cl, file); 112 cl_dbg(dev, cl, "removing\n"); 113 114 mei_cl_unlink(cl); 115 116 file->private_data = NULL; 117 118 kfree(cl); 119 out: 120 mutex_unlock(&dev->device_lock); 121 return rets; 122 } 123 124 125 /** 126 * mei_read - the read function. 127 * 128 * @file: pointer to file structure 129 * @ubuf: pointer to user buffer 130 * @length: buffer length 131 * @offset: data offset in buffer 132 * 133 * Return: >=0 data length on success , <0 on error 134 */ 135 static ssize_t mei_read(struct file *file, char __user *ubuf, 136 size_t length, loff_t *offset) 137 { 138 struct mei_cl *cl = file->private_data; 139 struct mei_device *dev; 140 struct mei_cl_cb *cb = NULL; 141 int rets; 142 int err; 143 144 145 if (WARN_ON(!cl || !cl->dev)) 146 return -ENODEV; 147 148 dev = cl->dev; 149 150 151 mutex_lock(&dev->device_lock); 152 if (dev->dev_state != MEI_DEV_ENABLED) { 153 rets = -ENODEV; 154 goto out; 155 } 156 157 if (length == 0) { 158 rets = 0; 159 goto out; 160 } 161 162 if (ubuf == NULL) { 163 rets = -EMSGSIZE; 164 goto out; 165 } 166 167 if (cl == &dev->iamthif_cl) { 168 rets = mei_amthif_read(dev, file, ubuf, length, offset); 169 goto out; 170 } 171 172 cb = mei_cl_read_cb(cl, file); 173 if (cb) 174 goto copy_buffer; 175 176 if (*offset > 0) 177 *offset = 0; 178 179 err = mei_cl_read_start(cl, length, file); 180 if (err && err != -EBUSY) { 181 cl_dbg(dev, cl, "mei start read failure status = %d\n", err); 182 rets = err; 183 goto out; 184 } 185 186 if (list_empty(&cl->rd_completed) && !waitqueue_active(&cl->rx_wait)) { 187 if (file->f_flags & O_NONBLOCK) { 188 rets = -EAGAIN; 189 goto out; 190 } 191 192 mutex_unlock(&dev->device_lock); 193 194 if (wait_event_interruptible(cl->rx_wait, 195 (!list_empty(&cl->rd_completed)) || 196 (!mei_cl_is_connected(cl)))) { 197 198 if (signal_pending(current)) 199 return -EINTR; 200 return -ERESTARTSYS; 201 } 202 203 mutex_lock(&dev->device_lock); 204 if (!mei_cl_is_connected(cl)) { 205 rets = -EBUSY; 206 goto out; 207 } 208 } 209 210 cb = mei_cl_read_cb(cl, file); 211 if (!cb) { 212 rets = 0; 213 goto out; 214 } 215 216 copy_buffer: 217 /* now copy the data to user space */ 218 if (cb->status) { 219 rets = cb->status; 220 cl_dbg(dev, cl, "read operation failed %d\n", rets); 221 goto free; 222 } 223 224 cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n", 225 cb->buf.size, cb->buf_idx, *offset); 226 if (*offset >= cb->buf_idx) { 227 rets = 0; 228 goto free; 229 } 230 231 /* length is being truncated to PAGE_SIZE, 232 * however buf_idx may point beyond that */ 233 length = min_t(size_t, length, cb->buf_idx - *offset); 234 235 if (copy_to_user(ubuf, cb->buf.data + *offset, length)) { 236 dev_dbg(dev->dev, "failed to copy data to userland\n"); 237 rets = -EFAULT; 238 goto free; 239 } 240 241 rets = length; 242 *offset += length; 243 /* not all data was read, keep the cb */ 244 if (*offset < cb->buf_idx) 245 goto out; 246 247 free: 248 mei_io_cb_free(cb); 249 *offset = 0; 250 251 out: 252 cl_dbg(dev, cl, "end mei read rets = %d\n", rets); 253 mutex_unlock(&dev->device_lock); 254 return rets; 255 } 256 /** 257 * mei_write - the write function. 258 * 259 * @file: pointer to file structure 260 * @ubuf: pointer to user buffer 261 * @length: buffer length 262 * @offset: data offset in buffer 263 * 264 * Return: >=0 data length on success , <0 on error 265 */ 266 static ssize_t mei_write(struct file *file, const char __user *ubuf, 267 size_t length, loff_t *offset) 268 { 269 struct mei_cl *cl = file->private_data; 270 struct mei_cl_cb *cb; 271 struct mei_device *dev; 272 int rets; 273 274 if (WARN_ON(!cl || !cl->dev)) 275 return -ENODEV; 276 277 dev = cl->dev; 278 279 mutex_lock(&dev->device_lock); 280 281 if (dev->dev_state != MEI_DEV_ENABLED) { 282 rets = -ENODEV; 283 goto out; 284 } 285 286 if (!mei_cl_is_connected(cl)) { 287 cl_err(dev, cl, "is not connected"); 288 rets = -ENODEV; 289 goto out; 290 } 291 292 if (!mei_me_cl_is_active(cl->me_cl)) { 293 rets = -ENOTTY; 294 goto out; 295 } 296 297 if (length > mei_cl_mtu(cl)) { 298 rets = -EFBIG; 299 goto out; 300 } 301 302 if (length == 0) { 303 rets = 0; 304 goto out; 305 } 306 307 *offset = 0; 308 cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file); 309 if (!cb) { 310 rets = -ENOMEM; 311 goto out; 312 } 313 314 rets = copy_from_user(cb->buf.data, ubuf, length); 315 if (rets) { 316 dev_dbg(dev->dev, "failed to copy data from userland\n"); 317 rets = -EFAULT; 318 mei_io_cb_free(cb); 319 goto out; 320 } 321 322 if (cl == &dev->iamthif_cl) { 323 rets = mei_amthif_write(cl, cb); 324 if (!rets) 325 rets = length; 326 goto out; 327 } 328 329 rets = mei_cl_write(cl, cb, false); 330 out: 331 mutex_unlock(&dev->device_lock); 332 return rets; 333 } 334 335 /** 336 * mei_ioctl_connect_client - the connect to fw client IOCTL function 337 * 338 * @file: private data of the file object 339 * @data: IOCTL connect data, input and output parameters 340 * 341 * Locking: called under "dev->device_lock" lock 342 * 343 * Return: 0 on success, <0 on failure. 344 */ 345 static int mei_ioctl_connect_client(struct file *file, 346 struct mei_connect_client_data *data) 347 { 348 struct mei_device *dev; 349 struct mei_client *client; 350 struct mei_me_client *me_cl; 351 struct mei_cl *cl; 352 int rets; 353 354 cl = file->private_data; 355 dev = cl->dev; 356 357 if (dev->dev_state != MEI_DEV_ENABLED) 358 return -ENODEV; 359 360 if (cl->state != MEI_FILE_INITIALIZING && 361 cl->state != MEI_FILE_DISCONNECTED) 362 return -EBUSY; 363 364 /* find ME client we're trying to connect to */ 365 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid); 366 if (!me_cl) { 367 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n", 368 &data->in_client_uuid); 369 rets = -ENOTTY; 370 goto end; 371 } 372 373 if (me_cl->props.fixed_address) { 374 bool forbidden = dev->override_fixed_address ? 375 !dev->allow_fixed_address : !dev->hbm_f_fa_supported; 376 if (forbidden) { 377 dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n", 378 &data->in_client_uuid); 379 rets = -ENOTTY; 380 goto end; 381 } 382 } 383 384 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n", 385 me_cl->client_id); 386 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n", 387 me_cl->props.protocol_version); 388 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n", 389 me_cl->props.max_msg_length); 390 391 /* if we're connecting to amthif client then we will use the 392 * existing connection 393 */ 394 if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) { 395 dev_dbg(dev->dev, "FW Client is amthi\n"); 396 if (!mei_cl_is_connected(&dev->iamthif_cl)) { 397 rets = -ENODEV; 398 goto end; 399 } 400 mei_cl_unlink(cl); 401 402 kfree(cl); 403 cl = NULL; 404 dev->iamthif_open_count++; 405 file->private_data = &dev->iamthif_cl; 406 407 client = &data->out_client_properties; 408 client->max_msg_length = me_cl->props.max_msg_length; 409 client->protocol_version = me_cl->props.protocol_version; 410 rets = dev->iamthif_cl.status; 411 412 goto end; 413 } 414 415 /* prepare the output buffer */ 416 client = &data->out_client_properties; 417 client->max_msg_length = me_cl->props.max_msg_length; 418 client->protocol_version = me_cl->props.protocol_version; 419 dev_dbg(dev->dev, "Can connect?\n"); 420 421 rets = mei_cl_connect(cl, me_cl, file); 422 423 end: 424 mei_me_cl_put(me_cl); 425 return rets; 426 } 427 428 /** 429 * mei_ioctl_client_notify_request - 430 * propagate event notification request to client 431 * 432 * @file: pointer to file structure 433 * @request: 0 - disable, 1 - enable 434 * 435 * Return: 0 on success , <0 on error 436 */ 437 static int mei_ioctl_client_notify_request(const struct file *file, u32 request) 438 { 439 struct mei_cl *cl = file->private_data; 440 441 if (request != MEI_HBM_NOTIFICATION_START && 442 request != MEI_HBM_NOTIFICATION_STOP) 443 return -EINVAL; 444 445 return mei_cl_notify_request(cl, file, (u8)request); 446 } 447 448 /** 449 * mei_ioctl_client_notify_get - wait for notification request 450 * 451 * @file: pointer to file structure 452 * @notify_get: 0 - disable, 1 - enable 453 * 454 * Return: 0 on success , <0 on error 455 */ 456 static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get) 457 { 458 struct mei_cl *cl = file->private_data; 459 bool notify_ev; 460 bool block = (file->f_flags & O_NONBLOCK) == 0; 461 int rets; 462 463 rets = mei_cl_notify_get(cl, block, ¬ify_ev); 464 if (rets) 465 return rets; 466 467 *notify_get = notify_ev ? 1 : 0; 468 return 0; 469 } 470 471 /** 472 * mei_ioctl - the IOCTL function 473 * 474 * @file: pointer to file structure 475 * @cmd: ioctl command 476 * @data: pointer to mei message structure 477 * 478 * Return: 0 on success , <0 on error 479 */ 480 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data) 481 { 482 struct mei_device *dev; 483 struct mei_cl *cl = file->private_data; 484 struct mei_connect_client_data connect_data; 485 u32 notify_get, notify_req; 486 int rets; 487 488 489 if (WARN_ON(!cl || !cl->dev)) 490 return -ENODEV; 491 492 dev = cl->dev; 493 494 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd); 495 496 mutex_lock(&dev->device_lock); 497 if (dev->dev_state != MEI_DEV_ENABLED) { 498 rets = -ENODEV; 499 goto out; 500 } 501 502 switch (cmd) { 503 case IOCTL_MEI_CONNECT_CLIENT: 504 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n"); 505 if (copy_from_user(&connect_data, (char __user *)data, 506 sizeof(struct mei_connect_client_data))) { 507 dev_dbg(dev->dev, "failed to copy data from userland\n"); 508 rets = -EFAULT; 509 goto out; 510 } 511 512 rets = mei_ioctl_connect_client(file, &connect_data); 513 if (rets) 514 goto out; 515 516 /* if all is ok, copying the data back to user. */ 517 if (copy_to_user((char __user *)data, &connect_data, 518 sizeof(struct mei_connect_client_data))) { 519 dev_dbg(dev->dev, "failed to copy data to userland\n"); 520 rets = -EFAULT; 521 goto out; 522 } 523 524 break; 525 526 case IOCTL_MEI_NOTIFY_SET: 527 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n"); 528 if (copy_from_user(¬ify_req, 529 (char __user *)data, sizeof(notify_req))) { 530 dev_dbg(dev->dev, "failed to copy data from userland\n"); 531 rets = -EFAULT; 532 goto out; 533 } 534 rets = mei_ioctl_client_notify_request(file, notify_req); 535 break; 536 537 case IOCTL_MEI_NOTIFY_GET: 538 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n"); 539 rets = mei_ioctl_client_notify_get(file, ¬ify_get); 540 if (rets) 541 goto out; 542 543 dev_dbg(dev->dev, "copy connect data to user\n"); 544 if (copy_to_user((char __user *)data, 545 ¬ify_get, sizeof(notify_get))) { 546 dev_dbg(dev->dev, "failed to copy data to userland\n"); 547 rets = -EFAULT; 548 goto out; 549 550 } 551 break; 552 553 default: 554 dev_err(dev->dev, ": unsupported ioctl %d.\n", cmd); 555 rets = -ENOIOCTLCMD; 556 } 557 558 out: 559 mutex_unlock(&dev->device_lock); 560 return rets; 561 } 562 563 /** 564 * mei_compat_ioctl - the compat IOCTL function 565 * 566 * @file: pointer to file structure 567 * @cmd: ioctl command 568 * @data: pointer to mei message structure 569 * 570 * Return: 0 on success , <0 on error 571 */ 572 #ifdef CONFIG_COMPAT 573 static long mei_compat_ioctl(struct file *file, 574 unsigned int cmd, unsigned long data) 575 { 576 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data)); 577 } 578 #endif 579 580 581 /** 582 * mei_poll - the poll function 583 * 584 * @file: pointer to file structure 585 * @wait: pointer to poll_table structure 586 * 587 * Return: poll mask 588 */ 589 static unsigned int mei_poll(struct file *file, poll_table *wait) 590 { 591 unsigned long req_events = poll_requested_events(wait); 592 struct mei_cl *cl = file->private_data; 593 struct mei_device *dev; 594 unsigned int mask = 0; 595 bool notify_en; 596 597 if (WARN_ON(!cl || !cl->dev)) 598 return POLLERR; 599 600 dev = cl->dev; 601 602 mutex_lock(&dev->device_lock); 603 604 notify_en = cl->notify_en && (req_events & POLLPRI); 605 606 if (dev->dev_state != MEI_DEV_ENABLED || 607 !mei_cl_is_connected(cl)) { 608 mask = POLLERR; 609 goto out; 610 } 611 612 if (cl == &dev->iamthif_cl) { 613 mask = mei_amthif_poll(dev, file, wait); 614 goto out; 615 } 616 617 if (notify_en) { 618 poll_wait(file, &cl->ev_wait, wait); 619 if (cl->notify_ev) 620 mask |= POLLPRI; 621 } 622 623 if (req_events & (POLLIN | POLLRDNORM)) { 624 poll_wait(file, &cl->rx_wait, wait); 625 626 if (!list_empty(&cl->rd_completed)) 627 mask |= POLLIN | POLLRDNORM; 628 else 629 mei_cl_read_start(cl, 0, file); 630 } 631 632 out: 633 mutex_unlock(&dev->device_lock); 634 return mask; 635 } 636 637 /** 638 * mei_fasync - asynchronous io support 639 * 640 * @fd: file descriptor 641 * @file: pointer to file structure 642 * @band: band bitmap 643 * 644 * Return: negative on error, 645 * 0 if it did no changes, 646 * and positive a process was added or deleted 647 */ 648 static int mei_fasync(int fd, struct file *file, int band) 649 { 650 651 struct mei_cl *cl = file->private_data; 652 653 if (!mei_cl_is_connected(cl)) 654 return -ENODEV; 655 656 return fasync_helper(fd, file, band, &cl->ev_async); 657 } 658 659 /** 660 * fw_status_show - mei device attribute show method 661 * 662 * @device: device pointer 663 * @attr: attribute pointer 664 * @buf: char out buffer 665 * 666 * Return: number of the bytes printed into buf or error 667 */ 668 static ssize_t fw_status_show(struct device *device, 669 struct device_attribute *attr, char *buf) 670 { 671 struct mei_device *dev = dev_get_drvdata(device); 672 struct mei_fw_status fw_status; 673 int err, i; 674 ssize_t cnt = 0; 675 676 mutex_lock(&dev->device_lock); 677 err = mei_fw_status(dev, &fw_status); 678 mutex_unlock(&dev->device_lock); 679 if (err) { 680 dev_err(device, "read fw_status error = %d\n", err); 681 return err; 682 } 683 684 for (i = 0; i < fw_status.count; i++) 685 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n", 686 fw_status.status[i]); 687 return cnt; 688 } 689 static DEVICE_ATTR_RO(fw_status); 690 691 static struct attribute *mei_attrs[] = { 692 &dev_attr_fw_status.attr, 693 NULL 694 }; 695 ATTRIBUTE_GROUPS(mei); 696 697 /* 698 * file operations structure will be used for mei char device. 699 */ 700 static const struct file_operations mei_fops = { 701 .owner = THIS_MODULE, 702 .read = mei_read, 703 .unlocked_ioctl = mei_ioctl, 704 #ifdef CONFIG_COMPAT 705 .compat_ioctl = mei_compat_ioctl, 706 #endif 707 .open = mei_open, 708 .release = mei_release, 709 .write = mei_write, 710 .poll = mei_poll, 711 .fasync = mei_fasync, 712 .llseek = no_llseek 713 }; 714 715 static struct class *mei_class; 716 static dev_t mei_devt; 717 #define MEI_MAX_DEVS MINORMASK 718 static DEFINE_MUTEX(mei_minor_lock); 719 static DEFINE_IDR(mei_idr); 720 721 /** 722 * mei_minor_get - obtain next free device minor number 723 * 724 * @dev: device pointer 725 * 726 * Return: allocated minor, or -ENOSPC if no free minor left 727 */ 728 static int mei_minor_get(struct mei_device *dev) 729 { 730 int ret; 731 732 mutex_lock(&mei_minor_lock); 733 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL); 734 if (ret >= 0) 735 dev->minor = ret; 736 else if (ret == -ENOSPC) 737 dev_err(dev->dev, "too many mei devices\n"); 738 739 mutex_unlock(&mei_minor_lock); 740 return ret; 741 } 742 743 /** 744 * mei_minor_free - mark device minor number as free 745 * 746 * @dev: device pointer 747 */ 748 static void mei_minor_free(struct mei_device *dev) 749 { 750 mutex_lock(&mei_minor_lock); 751 idr_remove(&mei_idr, dev->minor); 752 mutex_unlock(&mei_minor_lock); 753 } 754 755 int mei_register(struct mei_device *dev, struct device *parent) 756 { 757 struct device *clsdev; /* class device */ 758 int ret, devno; 759 760 ret = mei_minor_get(dev); 761 if (ret < 0) 762 return ret; 763 764 /* Fill in the data structures */ 765 devno = MKDEV(MAJOR(mei_devt), dev->minor); 766 cdev_init(&dev->cdev, &mei_fops); 767 dev->cdev.owner = parent->driver->owner; 768 769 /* Add the device */ 770 ret = cdev_add(&dev->cdev, devno, 1); 771 if (ret) { 772 dev_err(parent, "unable to add device %d:%d\n", 773 MAJOR(mei_devt), dev->minor); 774 goto err_dev_add; 775 } 776 777 clsdev = device_create_with_groups(mei_class, parent, devno, 778 dev, mei_groups, 779 "mei%d", dev->minor); 780 781 if (IS_ERR(clsdev)) { 782 dev_err(parent, "unable to create device %d:%d\n", 783 MAJOR(mei_devt), dev->minor); 784 ret = PTR_ERR(clsdev); 785 goto err_dev_create; 786 } 787 788 ret = mei_dbgfs_register(dev, dev_name(clsdev)); 789 if (ret) { 790 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret); 791 goto err_dev_dbgfs; 792 } 793 794 return 0; 795 796 err_dev_dbgfs: 797 device_destroy(mei_class, devno); 798 err_dev_create: 799 cdev_del(&dev->cdev); 800 err_dev_add: 801 mei_minor_free(dev); 802 return ret; 803 } 804 EXPORT_SYMBOL_GPL(mei_register); 805 806 void mei_deregister(struct mei_device *dev) 807 { 808 int devno; 809 810 devno = dev->cdev.dev; 811 cdev_del(&dev->cdev); 812 813 mei_dbgfs_deregister(dev); 814 815 device_destroy(mei_class, devno); 816 817 mei_minor_free(dev); 818 } 819 EXPORT_SYMBOL_GPL(mei_deregister); 820 821 static int __init mei_init(void) 822 { 823 int ret; 824 825 mei_class = class_create(THIS_MODULE, "mei"); 826 if (IS_ERR(mei_class)) { 827 pr_err("couldn't create class\n"); 828 ret = PTR_ERR(mei_class); 829 goto err; 830 } 831 832 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei"); 833 if (ret < 0) { 834 pr_err("unable to allocate char dev region\n"); 835 goto err_class; 836 } 837 838 ret = mei_cl_bus_init(); 839 if (ret < 0) { 840 pr_err("unable to initialize bus\n"); 841 goto err_chrdev; 842 } 843 844 return 0; 845 846 err_chrdev: 847 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS); 848 err_class: 849 class_destroy(mei_class); 850 err: 851 return ret; 852 } 853 854 static void __exit mei_exit(void) 855 { 856 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS); 857 class_destroy(mei_class); 858 mei_cl_bus_exit(); 859 } 860 861 module_init(mei_init); 862 module_exit(mei_exit); 863 864 MODULE_AUTHOR("Intel Corporation"); 865 MODULE_DESCRIPTION("Intel(R) Management Engine Interface"); 866 MODULE_LICENSE("GPL v2"); 867 868