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/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, &notify_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(&notify_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, &notify_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                                 &notify_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