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