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 = %zd buf.idx = %zd 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 *write_cb = NULL; 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 write_cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file); 309 if (!write_cb) { 310 rets = -ENOMEM; 311 goto out; 312 } 313 314 rets = copy_from_user(write_cb->buf.data, ubuf, length); 315 if (rets) { 316 dev_dbg(dev->dev, "failed to copy data from userland\n"); 317 rets = -EFAULT; 318 goto out; 319 } 320 321 if (cl == &dev->iamthif_cl) { 322 rets = mei_amthif_write(cl, write_cb); 323 324 if (rets) { 325 dev_err(dev->dev, 326 "amthif write failed with status = %d\n", rets); 327 goto out; 328 } 329 mutex_unlock(&dev->device_lock); 330 return length; 331 } 332 333 rets = mei_cl_write(cl, write_cb, false); 334 out: 335 mutex_unlock(&dev->device_lock); 336 if (rets < 0) 337 mei_io_cb_free(write_cb); 338 return rets; 339 } 340 341 /** 342 * mei_ioctl_connect_client - the connect to fw client IOCTL function 343 * 344 * @file: private data of the file object 345 * @data: IOCTL connect data, input and output parameters 346 * 347 * Locking: called under "dev->device_lock" lock 348 * 349 * Return: 0 on success, <0 on failure. 350 */ 351 static int mei_ioctl_connect_client(struct file *file, 352 struct mei_connect_client_data *data) 353 { 354 struct mei_device *dev; 355 struct mei_client *client; 356 struct mei_me_client *me_cl; 357 struct mei_cl *cl; 358 int rets; 359 360 cl = file->private_data; 361 dev = cl->dev; 362 363 if (dev->dev_state != MEI_DEV_ENABLED) 364 return -ENODEV; 365 366 if (cl->state != MEI_FILE_INITIALIZING && 367 cl->state != MEI_FILE_DISCONNECTED) 368 return -EBUSY; 369 370 /* find ME client we're trying to connect to */ 371 me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid); 372 if (!me_cl) { 373 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n", 374 &data->in_client_uuid); 375 rets = -ENOTTY; 376 goto end; 377 } 378 379 if (me_cl->props.fixed_address) { 380 bool forbidden = dev->override_fixed_address ? 381 !dev->allow_fixed_address : !dev->hbm_f_fa_supported; 382 if (forbidden) { 383 dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n", 384 &data->in_client_uuid); 385 rets = -ENOTTY; 386 goto end; 387 } 388 } 389 390 dev_dbg(dev->dev, "Connect to FW Client ID = %d\n", 391 me_cl->client_id); 392 dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n", 393 me_cl->props.protocol_version); 394 dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n", 395 me_cl->props.max_msg_length); 396 397 /* if we're connecting to amthif client then we will use the 398 * existing connection 399 */ 400 if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) { 401 dev_dbg(dev->dev, "FW Client is amthi\n"); 402 if (!mei_cl_is_connected(&dev->iamthif_cl)) { 403 rets = -ENODEV; 404 goto end; 405 } 406 mei_cl_unlink(cl); 407 408 kfree(cl); 409 cl = NULL; 410 dev->iamthif_open_count++; 411 file->private_data = &dev->iamthif_cl; 412 413 client = &data->out_client_properties; 414 client->max_msg_length = me_cl->props.max_msg_length; 415 client->protocol_version = me_cl->props.protocol_version; 416 rets = dev->iamthif_cl.status; 417 418 goto end; 419 } 420 421 /* prepare the output buffer */ 422 client = &data->out_client_properties; 423 client->max_msg_length = me_cl->props.max_msg_length; 424 client->protocol_version = me_cl->props.protocol_version; 425 dev_dbg(dev->dev, "Can connect?\n"); 426 427 rets = mei_cl_connect(cl, me_cl, file); 428 429 end: 430 mei_me_cl_put(me_cl); 431 return rets; 432 } 433 434 /** 435 * mei_ioctl_client_notify_request - 436 * propagate event notification request to client 437 * 438 * @file: pointer to file structure 439 * @request: 0 - disable, 1 - enable 440 * 441 * Return: 0 on success , <0 on error 442 */ 443 static int mei_ioctl_client_notify_request(const struct file *file, u32 request) 444 { 445 struct mei_cl *cl = file->private_data; 446 447 return mei_cl_notify_request(cl, file, request); 448 } 449 450 /** 451 * mei_ioctl_client_notify_get - wait for notification request 452 * 453 * @file: pointer to file structure 454 * @notify_get: 0 - disable, 1 - enable 455 * 456 * Return: 0 on success , <0 on error 457 */ 458 static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get) 459 { 460 struct mei_cl *cl = file->private_data; 461 bool notify_ev; 462 bool block = (file->f_flags & O_NONBLOCK) == 0; 463 int rets; 464 465 rets = mei_cl_notify_get(cl, block, ¬ify_ev); 466 if (rets) 467 return rets; 468 469 *notify_get = notify_ev ? 1 : 0; 470 return 0; 471 } 472 473 /** 474 * mei_ioctl - the IOCTL function 475 * 476 * @file: pointer to file structure 477 * @cmd: ioctl command 478 * @data: pointer to mei message structure 479 * 480 * Return: 0 on success , <0 on error 481 */ 482 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data) 483 { 484 struct mei_device *dev; 485 struct mei_cl *cl = file->private_data; 486 struct mei_connect_client_data connect_data; 487 u32 notify_get, notify_req; 488 int rets; 489 490 491 if (WARN_ON(!cl || !cl->dev)) 492 return -ENODEV; 493 494 dev = cl->dev; 495 496 dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd); 497 498 mutex_lock(&dev->device_lock); 499 if (dev->dev_state != MEI_DEV_ENABLED) { 500 rets = -ENODEV; 501 goto out; 502 } 503 504 switch (cmd) { 505 case IOCTL_MEI_CONNECT_CLIENT: 506 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n"); 507 if (copy_from_user(&connect_data, (char __user *)data, 508 sizeof(struct mei_connect_client_data))) { 509 dev_dbg(dev->dev, "failed to copy data from userland\n"); 510 rets = -EFAULT; 511 goto out; 512 } 513 514 rets = mei_ioctl_connect_client(file, &connect_data); 515 if (rets) 516 goto out; 517 518 /* if all is ok, copying the data back to user. */ 519 if (copy_to_user((char __user *)data, &connect_data, 520 sizeof(struct mei_connect_client_data))) { 521 dev_dbg(dev->dev, "failed to copy data to userland\n"); 522 rets = -EFAULT; 523 goto out; 524 } 525 526 break; 527 528 case IOCTL_MEI_NOTIFY_SET: 529 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n"); 530 if (copy_from_user(¬ify_req, 531 (char __user *)data, sizeof(notify_req))) { 532 dev_dbg(dev->dev, "failed to copy data from userland\n"); 533 rets = -EFAULT; 534 goto out; 535 } 536 rets = mei_ioctl_client_notify_request(file, notify_req); 537 break; 538 539 case IOCTL_MEI_NOTIFY_GET: 540 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n"); 541 rets = mei_ioctl_client_notify_get(file, ¬ify_get); 542 if (rets) 543 goto out; 544 545 dev_dbg(dev->dev, "copy connect data to user\n"); 546 if (copy_to_user((char __user *)data, 547 ¬ify_get, sizeof(notify_get))) { 548 dev_dbg(dev->dev, "failed to copy data to userland\n"); 549 rets = -EFAULT; 550 goto out; 551 552 } 553 break; 554 555 default: 556 dev_err(dev->dev, ": unsupported ioctl %d.\n", cmd); 557 rets = -ENOIOCTLCMD; 558 } 559 560 out: 561 mutex_unlock(&dev->device_lock); 562 return rets; 563 } 564 565 /** 566 * mei_compat_ioctl - the compat IOCTL function 567 * 568 * @file: pointer to file structure 569 * @cmd: ioctl command 570 * @data: pointer to mei message structure 571 * 572 * Return: 0 on success , <0 on error 573 */ 574 #ifdef CONFIG_COMPAT 575 static long mei_compat_ioctl(struct file *file, 576 unsigned int cmd, unsigned long data) 577 { 578 return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data)); 579 } 580 #endif 581 582 583 /** 584 * mei_poll - the poll function 585 * 586 * @file: pointer to file structure 587 * @wait: pointer to poll_table structure 588 * 589 * Return: poll mask 590 */ 591 static unsigned int mei_poll(struct file *file, poll_table *wait) 592 { 593 unsigned long req_events = poll_requested_events(wait); 594 struct mei_cl *cl = file->private_data; 595 struct mei_device *dev; 596 unsigned int mask = 0; 597 bool notify_en; 598 599 if (WARN_ON(!cl || !cl->dev)) 600 return POLLERR; 601 602 dev = cl->dev; 603 604 mutex_lock(&dev->device_lock); 605 606 notify_en = cl->notify_en && (req_events & POLLPRI); 607 608 if (dev->dev_state != MEI_DEV_ENABLED || 609 !mei_cl_is_connected(cl)) { 610 mask = POLLERR; 611 goto out; 612 } 613 614 if (cl == &dev->iamthif_cl) { 615 mask = mei_amthif_poll(dev, file, wait); 616 goto out; 617 } 618 619 if (notify_en) { 620 poll_wait(file, &cl->ev_wait, wait); 621 if (cl->notify_ev) 622 mask |= POLLPRI; 623 } 624 625 if (req_events & (POLLIN | POLLRDNORM)) { 626 poll_wait(file, &cl->rx_wait, wait); 627 628 if (!list_empty(&cl->rd_completed)) 629 mask |= POLLIN | POLLRDNORM; 630 else 631 mei_cl_read_start(cl, 0, file); 632 } 633 634 out: 635 mutex_unlock(&dev->device_lock); 636 return mask; 637 } 638 639 /** 640 * mei_fasync - asynchronous io support 641 * 642 * @fd: file descriptor 643 * @file: pointer to file structure 644 * @band: band bitmap 645 * 646 * Return: negative on error, 647 * 0 if it did no changes, 648 * and positive a process was added or deleted 649 */ 650 static int mei_fasync(int fd, struct file *file, int band) 651 { 652 653 struct mei_cl *cl = file->private_data; 654 655 if (!mei_cl_is_connected(cl)) 656 return -ENODEV; 657 658 return fasync_helper(fd, file, band, &cl->ev_async); 659 } 660 661 /** 662 * fw_status_show - mei device attribute show method 663 * 664 * @device: device pointer 665 * @attr: attribute pointer 666 * @buf: char out buffer 667 * 668 * Return: number of the bytes printed into buf or error 669 */ 670 static ssize_t fw_status_show(struct device *device, 671 struct device_attribute *attr, char *buf) 672 { 673 struct mei_device *dev = dev_get_drvdata(device); 674 struct mei_fw_status fw_status; 675 int err, i; 676 ssize_t cnt = 0; 677 678 mutex_lock(&dev->device_lock); 679 err = mei_fw_status(dev, &fw_status); 680 mutex_unlock(&dev->device_lock); 681 if (err) { 682 dev_err(device, "read fw_status error = %d\n", err); 683 return err; 684 } 685 686 for (i = 0; i < fw_status.count; i++) 687 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n", 688 fw_status.status[i]); 689 return cnt; 690 } 691 static DEVICE_ATTR_RO(fw_status); 692 693 static struct attribute *mei_attrs[] = { 694 &dev_attr_fw_status.attr, 695 NULL 696 }; 697 ATTRIBUTE_GROUPS(mei); 698 699 /* 700 * file operations structure will be used for mei char device. 701 */ 702 static const struct file_operations mei_fops = { 703 .owner = THIS_MODULE, 704 .read = mei_read, 705 .unlocked_ioctl = mei_ioctl, 706 #ifdef CONFIG_COMPAT 707 .compat_ioctl = mei_compat_ioctl, 708 #endif 709 .open = mei_open, 710 .release = mei_release, 711 .write = mei_write, 712 .poll = mei_poll, 713 .fasync = mei_fasync, 714 .llseek = no_llseek 715 }; 716 717 static struct class *mei_class; 718 static dev_t mei_devt; 719 #define MEI_MAX_DEVS MINORMASK 720 static DEFINE_MUTEX(mei_minor_lock); 721 static DEFINE_IDR(mei_idr); 722 723 /** 724 * mei_minor_get - obtain next free device minor number 725 * 726 * @dev: device pointer 727 * 728 * Return: allocated minor, or -ENOSPC if no free minor left 729 */ 730 static int mei_minor_get(struct mei_device *dev) 731 { 732 int ret; 733 734 mutex_lock(&mei_minor_lock); 735 ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL); 736 if (ret >= 0) 737 dev->minor = ret; 738 else if (ret == -ENOSPC) 739 dev_err(dev->dev, "too many mei devices\n"); 740 741 mutex_unlock(&mei_minor_lock); 742 return ret; 743 } 744 745 /** 746 * mei_minor_free - mark device minor number as free 747 * 748 * @dev: device pointer 749 */ 750 static void mei_minor_free(struct mei_device *dev) 751 { 752 mutex_lock(&mei_minor_lock); 753 idr_remove(&mei_idr, dev->minor); 754 mutex_unlock(&mei_minor_lock); 755 } 756 757 int mei_register(struct mei_device *dev, struct device *parent) 758 { 759 struct device *clsdev; /* class device */ 760 int ret, devno; 761 762 ret = mei_minor_get(dev); 763 if (ret < 0) 764 return ret; 765 766 /* Fill in the data structures */ 767 devno = MKDEV(MAJOR(mei_devt), dev->minor); 768 cdev_init(&dev->cdev, &mei_fops); 769 dev->cdev.owner = parent->driver->owner; 770 771 /* Add the device */ 772 ret = cdev_add(&dev->cdev, devno, 1); 773 if (ret) { 774 dev_err(parent, "unable to add device %d:%d\n", 775 MAJOR(mei_devt), dev->minor); 776 goto err_dev_add; 777 } 778 779 clsdev = device_create_with_groups(mei_class, parent, devno, 780 dev, mei_groups, 781 "mei%d", dev->minor); 782 783 if (IS_ERR(clsdev)) { 784 dev_err(parent, "unable to create device %d:%d\n", 785 MAJOR(mei_devt), dev->minor); 786 ret = PTR_ERR(clsdev); 787 goto err_dev_create; 788 } 789 790 ret = mei_dbgfs_register(dev, dev_name(clsdev)); 791 if (ret) { 792 dev_err(clsdev, "cannot register debugfs ret = %d\n", ret); 793 goto err_dev_dbgfs; 794 } 795 796 return 0; 797 798 err_dev_dbgfs: 799 device_destroy(mei_class, devno); 800 err_dev_create: 801 cdev_del(&dev->cdev); 802 err_dev_add: 803 mei_minor_free(dev); 804 return ret; 805 } 806 EXPORT_SYMBOL_GPL(mei_register); 807 808 void mei_deregister(struct mei_device *dev) 809 { 810 int devno; 811 812 devno = dev->cdev.dev; 813 cdev_del(&dev->cdev); 814 815 mei_dbgfs_deregister(dev); 816 817 device_destroy(mei_class, devno); 818 819 mei_minor_free(dev); 820 } 821 EXPORT_SYMBOL_GPL(mei_deregister); 822 823 static int __init mei_init(void) 824 { 825 int ret; 826 827 mei_class = class_create(THIS_MODULE, "mei"); 828 if (IS_ERR(mei_class)) { 829 pr_err("couldn't create class\n"); 830 ret = PTR_ERR(mei_class); 831 goto err; 832 } 833 834 ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei"); 835 if (ret < 0) { 836 pr_err("unable to allocate char dev region\n"); 837 goto err_class; 838 } 839 840 ret = mei_cl_bus_init(); 841 if (ret < 0) { 842 pr_err("unable to initialize bus\n"); 843 goto err_chrdev; 844 } 845 846 return 0; 847 848 err_chrdev: 849 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS); 850 err_class: 851 class_destroy(mei_class); 852 err: 853 return ret; 854 } 855 856 static void __exit mei_exit(void) 857 { 858 unregister_chrdev_region(mei_devt, MEI_MAX_DEVS); 859 class_destroy(mei_class); 860 mei_cl_bus_exit(); 861 } 862 863 module_init(mei_init); 864 module_exit(mei_exit); 865 866 MODULE_AUTHOR("Intel Corporation"); 867 MODULE_DESCRIPTION("Intel(R) Management Engine Interface"); 868 MODULE_LICENSE("GPL v2"); 869 870