drivers/misc/mei/main.c

   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
  17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  18
  19 #include <linux/module.h>
  20 #include <linux/moduleparam.h>
  21 #include <linux/kernel.h>
  22 #include <linux/device.h>
  23 #include <linux/fs.h>
  24 #include <linux/errno.h>
  25 #include <linux/types.h>
  26 #include <linux/fcntl.h>
  27 #include <linux/aio.h>
  28 #include <linux/pci.h>
  29 #include <linux/poll.h>
  30 #include <linux/init.h>
  31 #include <linux/ioctl.h>
  32 #include <linux/cdev.h>
  33 #include <linux/sched.h>
  34 #include <linux/uuid.h>
  35 #include <linux/compat.h>
  36 #include <linux/jiffies.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/miscdevice.h>
  39
  40 #include <linux/mei.h>
  41
  42 #include "mei_dev.h"
  43 #include "hw-me.h"
  44 #include "client.h"
  45
  46 /**
  47  * mei_open - the open function
  48  *
  49  * @inode: pointer to inode structure
  50  * @file: pointer to file structure
  51  e
  52  * returns 0 on success, <0 on error
  53  */
  54 static int mei_open(struct inode *inode, struct file *file)
  55 {
  56         struct miscdevice *misc = file->private_data;
  57         struct pci_dev *pdev;
  58         struct mei_cl *cl;
  59         struct mei_device *dev;
  60
  61         int err;
  62
  63         err = -ENODEV;
  64         if (!misc->parent)
  65                 goto out;
  66
  67         pdev = container_of(misc->parent, struct pci_dev, dev);
  68
  69         dev = pci_get_drvdata(pdev);
  70         if (!dev)
  71                 goto out;
  72
  73         mutex_lock(&dev->device_lock);
  74         err = -ENOMEM;
  75         cl = mei_cl_allocate(dev);
  76         if (!cl)
  77                 goto out_unlock;
  78
  79         err = -ENODEV;
  80         if (dev->dev_state != MEI_DEV_ENABLED) {
  81                 dev_dbg(&dev->pdev->dev, "dev_state != MEI_ENABLED  dev_state = %s\n",
  82                     mei_dev_state_str(dev->dev_state));
  83                 goto out_unlock;
  84         }
  85         err = -EMFILE;
  86         if (dev->open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
  87                 dev_err(&dev->pdev->dev, "open_handle_count exceded %d",
  88                         MEI_MAX_OPEN_HANDLE_COUNT);
  89                 goto out_unlock;
  90         }
  91
  92         err = mei_cl_link(cl, MEI_HOST_CLIENT_ID_ANY);
  93         if (err)
  94                 goto out_unlock;
  95
  96         file->private_data = cl;
  97         mutex_unlock(&dev->device_lock);
  98
  99         return nonseekable_open(inode, file);
 100
 101 out_unlock:
 102         mutex_unlock(&dev->device_lock);
 103         kfree(cl);
 104 out:
 105         return err;
 106 }
 107
 108 /**
 109  * mei_release - the release function
 110  *
 111  * @inode: pointer to inode structure
 112  * @file: pointer to file structure
 113  *
 114  * returns 0 on success, <0 on error
 115  */
 116 static int mei_release(struct inode *inode, struct file *file)
 117 {
 118         struct mei_cl *cl = file->private_data;
 119         struct mei_cl_cb *cb;
 120         struct mei_device *dev;
 121         int rets = 0;
 122
 123         if (WARN_ON(!cl || !cl->dev))
 124                 return -ENODEV;
 125
 126         dev = cl->dev;
 127
 128         mutex_lock(&dev->device_lock);
 129         if (cl == &dev->iamthif_cl) {
 130                 rets = mei_amthif_release(dev, file);
 131                 goto out;
 132         }
 133         if (cl->state == MEI_FILE_CONNECTED) {
 134                 cl->state = MEI_FILE_DISCONNECTING;
 135                 dev_dbg(&dev->pdev->dev,
 136                         "disconnecting client host client = %d, "
 137                     "ME client = %d\n",
 138                     cl->host_client_id,
 139                     cl->me_client_id);
 140                 rets = mei_cl_disconnect(cl);
 141         }
 142         mei_cl_flush_queues(cl);
 143         dev_dbg(&dev->pdev->dev, "remove client host client = %d, ME client = %d\n",
 144             cl->host_client_id,
 145             cl->me_client_id);
 146
 147         if (dev->open_handle_count > 0) {
 148                 clear_bit(cl->host_client_id, dev->host_clients_map);
 149                 dev->open_handle_count--;
 150         }
 151         mei_cl_unlink(cl);
 152
 153
 154         /* free read cb */
 155         cb = NULL;
 156         if (cl->read_cb) {
 157                 cb = mei_cl_find_read_cb(cl);
 158                 /* Remove entry from read list */
 159                 if (cb)
 160                         list_del(&cb->list);
 161
 162                 cb = cl->read_cb;
 163                 cl->read_cb = NULL;
 164         }
 165
 166         file->private_data = NULL;
 167
 168         if (cb) {
 169                 mei_io_cb_free(cb);
 170                 cb = NULL;
 171         }
 172
 173         kfree(cl);
 174 out:
 175         mutex_unlock(&dev->device_lock);
 176         return rets;
 177 }
 178
 179
 180 /**
 181  * mei_read - the read function.
 182  *
 183  * @file: pointer to file structure
 184  * @ubuf: pointer to user buffer
 185  * @length: buffer length
 186  * @offset: data offset in buffer
 187  *
 188  * returns >=0 data length on success , <0 on error
 189  */
 190 static ssize_t mei_read(struct file *file, char __user *ubuf,
 191                         size_t length, loff_t *offset)
 192 {
 193         struct mei_cl *cl = file->private_data;
 194         struct mei_cl_cb *cb_pos = NULL;
 195         struct mei_cl_cb *cb = NULL;
 196         struct mei_device *dev;
 197         int i;
 198         int rets;
 199         int err;
 200
 201
 202         if (WARN_ON(!cl || !cl->dev))
 203                 return -ENODEV;
 204
 205         dev = cl->dev;
 206
 207         mutex_lock(&dev->device_lock);
 208         if (dev->dev_state != MEI_DEV_ENABLED) {
 209                 rets = -ENODEV;
 210                 goto out;
 211         }
 212
 213         if ((cl->sm_state & MEI_WD_STATE_INDEPENDENCE_MSG_SENT) == 0) {
 214                 /* Do not allow to read watchdog client */
 215                 i = mei_me_cl_by_uuid(dev, &mei_wd_guid);
 216                 if (i >= 0) {
 217                         struct mei_me_client *me_client = &dev->me_clients[i];
 218                         if (cl->me_client_id == me_client->client_id) {
 219                                 rets = -EBADF;
 220                                 goto out;
 221                         }
 222                 }
 223         } else {
 224                 cl->sm_state &= ~MEI_WD_STATE_INDEPENDENCE_MSG_SENT;
 225         }
 226
 227         if (cl == &dev->iamthif_cl) {
 228                 rets = mei_amthif_read(dev, file, ubuf, length, offset);
 229                 goto out;
 230         }
 231
 232         if (cl->read_cb && cl->read_cb->buf_idx > *offset) {
 233                 cb = cl->read_cb;
 234                 goto copy_buffer;
 235         } else if (cl->read_cb && cl->read_cb->buf_idx > 0 &&
 236                    cl->read_cb->buf_idx <= *offset) {
 237                 cb = cl->read_cb;
 238                 rets = 0;
 239                 goto free;
 240         } else if ((!cl->read_cb || !cl->read_cb->buf_idx) && *offset > 0) {
 241                 /*Offset needs to be cleaned for contiguous reads*/
 242                 *offset = 0;
 243                 rets = 0;
 244                 goto out;
 245         }
 246
 247         err = mei_cl_read_start(cl, length);
 248         if (err && err != -EBUSY) {
 249                 dev_dbg(&dev->pdev->dev,
 250                         "mei start read failure with status = %d\n", err);
 251                 rets = err;
 252                 goto out;
 253         }
 254
 255         if (MEI_READ_COMPLETE != cl->reading_state &&
 256                         !waitqueue_active(&cl->rx_wait)) {
 257                 if (file->f_flags & O_NONBLOCK) {
 258                         rets = -EAGAIN;
 259                         goto out;
 260                 }
 261
 262                 mutex_unlock(&dev->device_lock);
 263
 264                 if (wait_event_interruptible(cl->rx_wait,
 265                         (MEI_READ_COMPLETE == cl->reading_state ||
 266                          MEI_FILE_INITIALIZING == cl->state ||
 267                          MEI_FILE_DISCONNECTED == cl->state ||
 268                          MEI_FILE_DISCONNECTING == cl->state))) {
 269                         if (signal_pending(current))
 270                                 return -EINTR;
 271                         return -ERESTARTSYS;
 272                 }
 273
 274                 mutex_lock(&dev->device_lock);
 275                 if (MEI_FILE_INITIALIZING == cl->state ||
 276                     MEI_FILE_DISCONNECTED == cl->state ||
 277                     MEI_FILE_DISCONNECTING == cl->state) {
 278                         rets = -EBUSY;
 279                         goto out;
 280                 }
 281         }
 282
 283         cb = cl->read_cb;
 284
 285         if (!cb) {
 286                 rets = -ENODEV;
 287                 goto out;
 288         }
 289         if (cl->reading_state != MEI_READ_COMPLETE) {
 290                 rets = 0;
 291                 goto out;
 292         }
 293         /* now copy the data to user space */
 294 copy_buffer:
 295         dev_dbg(&dev->pdev->dev, "buf.size = %d buf.idx= %ld\n",
 296             cb->response_buffer.size, cb->buf_idx);
 297         if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
 298                 rets = -EMSGSIZE;
 299                 goto free;
 300         }
 301
 302         /* length is being truncated to PAGE_SIZE,
 303          * however buf_idx may point beyond that */
 304         length = min_t(size_t, length, cb->buf_idx - *offset);
 305
 306         if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length)) {
 307                 rets = -EFAULT;
 308                 goto free;
 309         }
 310
 311         rets = length;
 312         *offset += length;
 313         if ((unsigned long)*offset < cb->buf_idx)
 314                 goto out;
 315
 316 free:
 317         cb_pos = mei_cl_find_read_cb(cl);
 318         /* Remove entry from read list */
 319         if (cb_pos)
 320                 list_del(&cb_pos->list);
 321         mei_io_cb_free(cb);
 322         cl->reading_state = MEI_IDLE;
 323         cl->read_cb = NULL;
 324 out:
 325         dev_dbg(&dev->pdev->dev, "end mei read rets= %d\n", rets);
 326         mutex_unlock(&dev->device_lock);
 327         return rets;
 328 }
 329 /**
 330  * mei_write - the write function.
 331  *
 332  * @file: pointer to file structure
 333  * @ubuf: pointer to user buffer
 334  * @length: buffer length
 335  * @offset: data offset in buffer
 336  *
 337  * returns >=0 data length on success , <0 on error
 338  */
 339 static ssize_t mei_write(struct file *file, const char __user *ubuf,
 340                          size_t length, loff_t *offset)
 341 {
 342         struct mei_cl *cl = file->private_data;
 343         struct mei_cl_cb *write_cb = NULL;
 344         struct mei_device *dev;
 345         unsigned long timeout = 0;
 346         int rets;
 347         int id;
 348
 349         if (WARN_ON(!cl || !cl->dev))
 350                 return -ENODEV;
 351
 352         dev = cl->dev;
 353
 354         mutex_lock(&dev->device_lock);
 355
 356         if (dev->dev_state != MEI_DEV_ENABLED) {
 357                 rets = -ENODEV;
 358                 goto out;
 359         }
 360
 361         id = mei_me_cl_by_id(dev, cl->me_client_id);
 362         if (id < 0) {
 363                 rets = -ENODEV;
 364                 goto out;
 365         }
 366         if (length > dev->me_clients[id].props.max_msg_length || length <= 0) {
 367                 rets = -EMSGSIZE;
 368                 goto out;
 369         }
 370
 371         if (cl->state != MEI_FILE_CONNECTED) {
 372                 dev_err(&dev->pdev->dev, "host client = %d,  is not connected to ME client = %d",
 373                         cl->host_client_id, cl->me_client_id);
 374                 rets = -ENODEV;
 375                 goto out;
 376         }
 377         if (cl == &dev->iamthif_cl) {
 378                 write_cb = mei_amthif_find_read_list_entry(dev, file);
 379
 380                 if (write_cb) {
 381                         timeout = write_cb->read_time +
 382                                 mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
 383
 384                         if (time_after(jiffies, timeout) ||
 385                             cl->reading_state == MEI_READ_COMPLETE) {
 386                                 *offset = 0;
 387                                 list_del(&write_cb->list);
 388                                 mei_io_cb_free(write_cb);
 389                                 write_cb = NULL;
 390                         }
 391                 }
 392         }
 393
 394         /* free entry used in read */
 395         if (cl->reading_state == MEI_READ_COMPLETE) {
 396                 *offset = 0;
 397                 write_cb = mei_cl_find_read_cb(cl);
 398                 if (write_cb) {
 399                         list_del(&write_cb->list);
 400                         mei_io_cb_free(write_cb);
 401                         write_cb = NULL;
 402                         cl->reading_state = MEI_IDLE;
 403                         cl->read_cb = NULL;
 404                 }
 405         } else if (cl->reading_state == MEI_IDLE)
 406                 *offset = 0;
 407
 408
 409         write_cb = mei_io_cb_init(cl, file);
 410         if (!write_cb) {
 411                 dev_err(&dev->pdev->dev, "write cb allocation failed\n");
 412                 rets = -ENOMEM;
 413                 goto out;
 414         }
 415         rets = mei_io_cb_alloc_req_buf(write_cb, length);
 416         if (rets)
 417                 goto out;
 418
 419         rets = copy_from_user(write_cb->request_buffer.data, ubuf, length);
 420         if (rets)
 421                 goto out;
 422
 423         cl->sm_state = 0;
 424         if (length == 4 &&
 425             ((memcmp(mei_wd_state_independence_msg[0],
 426                                  write_cb->request_buffer.data, 4) == 0) ||
 427              (memcmp(mei_wd_state_independence_msg[1],
 428                                  write_cb->request_buffer.data, 4) == 0) ||
 429              (memcmp(mei_wd_state_independence_msg[2],
 430                                  write_cb->request_buffer.data, 4) == 0)))
 431                 cl->sm_state |= MEI_WD_STATE_INDEPENDENCE_MSG_SENT;
 432
 433         if (cl == &dev->iamthif_cl) {
 434                 rets = mei_amthif_write(dev, write_cb);
 435
 436                 if (rets) {
 437                         dev_err(&dev->pdev->dev,
 438                                 "amthif write failed with status = %d\n", rets);
 439                         goto out;
 440                 }
 441                 mutex_unlock(&dev->device_lock);
 442                 return length;
 443         }
 444
 445         rets = mei_cl_write(cl, write_cb, false);
 446 out:
 447         mutex_unlock(&dev->device_lock);
 448         if (rets < 0)
 449                 mei_io_cb_free(write_cb);
 450         return rets;
 451 }
 452
 453 /**
 454  * mei_ioctl_connect_client - the connect to fw client IOCTL function
 455  *
 456  * @dev: the device structure
 457  * @data: IOCTL connect data, input and output parameters
 458  * @file: private data of the file object
 459  *
 460  * Locking: called under "dev->device_lock" lock
 461  *
 462  * returns 0 on success, <0 on failure.
 463  */
 464 static int mei_ioctl_connect_client(struct file *file,
 465                         struct mei_connect_client_data *data)
 466 {
 467         struct mei_device *dev;
 468         struct mei_client *client;
 469         struct mei_cl *cl;
 470         int i;
 471         int rets;
 472
 473         cl = file->private_data;
 474         if (WARN_ON(!cl || !cl->dev))
 475                 return -ENODEV;
 476
 477         dev = cl->dev;
 478
 479         if (dev->dev_state != MEI_DEV_ENABLED) {
 480                 rets = -ENODEV;
 481                 goto end;
 482         }
 483
 484         if (cl->state != MEI_FILE_INITIALIZING &&
 485             cl->state != MEI_FILE_DISCONNECTED) {
 486                 rets = -EBUSY;
 487                 goto end;
 488         }
 489
 490         /* find ME client we're trying to connect to */
 491         i = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
 492         if (i >= 0 && !dev->me_clients[i].props.fixed_address) {
 493                 cl->me_client_id = dev->me_clients[i].client_id;
 494                 cl->state = MEI_FILE_CONNECTING;
 495         }
 496
 497         dev_dbg(&dev->pdev->dev, "Connect to FW Client ID = %d\n",
 498                         cl->me_client_id);
 499         dev_dbg(&dev->pdev->dev, "FW Client - Protocol Version = %d\n",
 500                         dev->me_clients[i].props.protocol_version);
 501         dev_dbg(&dev->pdev->dev, "FW Client - Max Msg Len = %d\n",
 502                         dev->me_clients[i].props.max_msg_length);
 503
 504         /* if we're connecting to amthif client then we will use the
 505          * existing connection
 506          */
 507         if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
 508                 dev_dbg(&dev->pdev->dev, "FW Client is amthi\n");
 509                 if (dev->iamthif_cl.state != MEI_FILE_CONNECTED) {
 510                         rets = -ENODEV;
 511                         goto end;
 512                 }
 513                 clear_bit(cl->host_client_id, dev->host_clients_map);
 514                 mei_cl_unlink(cl);
 515
 516                 kfree(cl);
 517                 cl = NULL;
 518                 file->private_data = &dev->iamthif_cl;
 519
 520                 client = &data->out_client_properties;
 521                 client->max_msg_length =
 522                         dev->me_clients[i].props.max_msg_length;
 523                 client->protocol_version =
 524                         dev->me_clients[i].props.protocol_version;
 525                 rets = dev->iamthif_cl.status;
 526
 527                 goto end;
 528         }
 529
 530         if (cl->state != MEI_FILE_CONNECTING) {
 531                 rets = -ENODEV;
 532                 goto end;
 533         }
 534
 535
 536         /* prepare the output buffer */
 537         client = &data->out_client_properties;
 538         client->max_msg_length = dev->me_clients[i].props.max_msg_length;
 539         client->protocol_version = dev->me_clients[i].props.protocol_version;
 540         dev_dbg(&dev->pdev->dev, "Can connect?\n");
 541
 542
 543         rets = mei_cl_connect(cl, file);
 544
 545 end:
 546         dev_dbg(&dev->pdev->dev, "free connect cb memory.");
 547         return rets;
 548 }
 549
 550
 551 /**
 552  * mei_ioctl - the IOCTL function
 553  *
 554  * @file: pointer to file structure
 555  * @cmd: ioctl command
 556  * @data: pointer to mei message structure
 557  *
 558  * returns 0 on success , <0 on error
 559  */
 560 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
 561 {
 562         struct mei_device *dev;
 563         struct mei_cl *cl = file->private_data;
 564         struct mei_connect_client_data *connect_data = NULL;
 565         int rets;
 566
 567         if (cmd != IOCTL_MEI_CONNECT_CLIENT)
 568                 return -EINVAL;
 569
 570         if (WARN_ON(!cl || !cl->dev))
 571                 return -ENODEV;
 572
 573         dev = cl->dev;
 574
 575         dev_dbg(&dev->pdev->dev, "IOCTL cmd = 0x%x", cmd);
 576
 577         mutex_lock(&dev->device_lock);
 578         if (dev->dev_state != MEI_DEV_ENABLED) {
 579                 rets = -ENODEV;
 580                 goto out;
 581         }
 582
 583         dev_dbg(&dev->pdev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
 584
 585         connect_data = kzalloc(sizeof(struct mei_connect_client_data),
 586                                                         GFP_KERNEL);
 587         if (!connect_data) {
 588                 rets = -ENOMEM;
 589                 goto out;
 590         }
 591         dev_dbg(&dev->pdev->dev, "copy connect data from user\n");
 592         if (copy_from_user(connect_data, (char __user *)data,
 593                                 sizeof(struct mei_connect_client_data))) {
 594                 dev_dbg(&dev->pdev->dev, "failed to copy data from userland\n");
 595                 rets = -EFAULT;
 596                 goto out;
 597         }
 598
 599         rets = mei_ioctl_connect_client(file, connect_data);
 600
 601         /* if all is ok, copying the data back to user. */
 602         if (rets)
 603                 goto out;
 604
 605         dev_dbg(&dev->pdev->dev, "copy connect data to user\n");
 606         if (copy_to_user((char __user *)data, connect_data,
 607                                 sizeof(struct mei_connect_client_data))) {
 608                 dev_dbg(&dev->pdev->dev, "failed to copy data to userland\n");
 609                 rets = -EFAULT;
 610                 goto out;
 611         }
 612
 613 out:
 614         kfree(connect_data);
 615         mutex_unlock(&dev->device_lock);
 616         return rets;
 617 }
 618
 619 /**
 620  * mei_compat_ioctl - the compat IOCTL function
 621  *
 622  * @file: pointer to file structure
 623  * @cmd: ioctl command
 624  * @data: pointer to mei message structure
 625  *
 626  * returns 0 on success , <0 on error
 627  */
 628 #ifdef CONFIG_COMPAT
 629 static long mei_compat_ioctl(struct file *file,
 630                         unsigned int cmd, unsigned long data)
 631 {
 632         return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
 633 }
 634 #endif
 635
 636
 637 /**
 638  * mei_poll - the poll function
 639  *
 640  * @file: pointer to file structure
 641  * @wait: pointer to poll_table structure
 642  *
 643  * returns poll mask
 644  */
 645 static unsigned int mei_poll(struct file *file, poll_table *wait)
 646 {
 647         struct mei_cl *cl = file->private_data;
 648         struct mei_device *dev;
 649         unsigned int mask = 0;
 650
 651         if (WARN_ON(!cl || !cl->dev))
 652                 return mask;
 653
 654         dev = cl->dev;
 655
 656         mutex_lock(&dev->device_lock);
 657
 658         if (dev->dev_state != MEI_DEV_ENABLED)
 659                 goto out;
 660
 661
 662         if (cl == &dev->iamthif_cl) {
 663                 mask = mei_amthif_poll(dev, file, wait);
 664                 goto out;
 665         }
 666
 667         mutex_unlock(&dev->device_lock);
 668         poll_wait(file, &cl->tx_wait, wait);
 669         mutex_lock(&dev->device_lock);
 670         if (MEI_WRITE_COMPLETE == cl->writing_state)
 671                 mask |= (POLLIN | POLLRDNORM);
 672
 673 out:
 674         mutex_unlock(&dev->device_lock);
 675         return mask;
 676 }
 677
 678 /*
 679  * file operations structure will be used for mei char device.
 680  */
 681 static const struct file_operations mei_fops = {
 682         .owner = THIS_MODULE,
 683         .read = mei_read,
 684         .unlocked_ioctl = mei_ioctl,
 685 #ifdef CONFIG_COMPAT
 686         .compat_ioctl = mei_compat_ioctl,
 687 #endif
 688         .open = mei_open,
 689         .release = mei_release,
 690         .write = mei_write,
 691         .poll = mei_poll,
 692         .llseek = no_llseek
 693 };
 694
 695 /*
 696  * Misc Device Struct
 697  */
 698 static struct miscdevice  mei_misc_device = {
 699                 .name = "mei",
 700                 .fops = &mei_fops,
 701                 .minor = MISC_DYNAMIC_MINOR,
 702 };
 703
 704
 705 int mei_register(struct mei_device *dev)
 706 {
 707         int ret;
 708         mei_misc_device.parent = &dev->pdev->dev;
 709         ret = misc_register(&mei_misc_device);
 710         if (ret)
 711                 return ret;
 712
 713         if (mei_dbgfs_register(dev, mei_misc_device.name))
 714                 dev_err(&dev->pdev->dev, "cannot register debugfs\n");
 715
 716         return 0;
 717 }
 718 EXPORT_SYMBOL_GPL(mei_register);
 719
 720 void mei_deregister(struct mei_device *dev)
 721 {
 722         mei_dbgfs_deregister(dev);
 723         misc_deregister(&mei_misc_device);
 724         mei_misc_device.parent = NULL;
 725 }
 726 EXPORT_SYMBOL_GPL(mei_deregister);
 727
 728 static int __init mei_init(void)
 729 {
 730         return mei_cl_bus_init();
 731 }
 732
 733 static void __exit mei_exit(void)
 734 {
 735         mei_cl_bus_exit();
 736 }
 737
 738 module_init(mei_init);
 739 module_exit(mei_exit);
 740
 741 MODULE_AUTHOR("Intel Corporation");
 742 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
 743 MODULE_LICENSE("GPL v2");
 744