drivers/misc/mei/main.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2003-2018, Intel Corporation. All rights reserved.
   4  * Intel Management Engine Interface (Intel MEI) Linux driver
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/moduleparam.h>
   9 #include <linux/kernel.h>
  10 #include <linux/device.h>
  11 #include <linux/slab.h>
  12 #include <linux/fs.h>
  13 #include <linux/errno.h>
  14 #include <linux/types.h>
  15 #include <linux/fcntl.h>
  16 #include <linux/poll.h>
  17 #include <linux/init.h>
  18 #include <linux/ioctl.h>
  19 #include <linux/cdev.h>
  20 #include <linux/sched/signal.h>
  21 #include <linux/uuid.h>
  22 #include <linux/compat.h>
  23 #include <linux/jiffies.h>
  24 #include <linux/interrupt.h>
  25
  26 #include <linux/mei.h>
  27
  28 #include "mei_dev.h"
  29 #include "client.h"
  30
  31 static struct class *mei_class;
  32 static dev_t mei_devt;
  33 #define MEI_MAX_DEVS  MINORMASK
  34 static DEFINE_MUTEX(mei_minor_lock);
  35 static DEFINE_IDR(mei_idr);
  36
  37 /**
  38  * mei_open - the open function
  39  *
  40  * @inode: pointer to inode structure
  41  * @file: pointer to file structure
  42  *
  43  * Return: 0 on success, <0 on error
  44  */
  45 static int mei_open(struct inode *inode, struct file *file)
  46 {
  47         struct mei_device *dev;
  48         struct mei_cl *cl;
  49
  50         int err;
  51
  52         dev = container_of(inode->i_cdev, struct mei_device, cdev);
  53         if (!dev)
  54                 return -ENODEV;
  55
  56         mutex_lock(&dev->device_lock);
  57
  58         if (dev->dev_state != MEI_DEV_ENABLED) {
  59                 dev_dbg(dev->dev, "dev_state != MEI_ENABLED  dev_state = %s\n",
  60                     mei_dev_state_str(dev->dev_state));
  61                 err = -ENODEV;
  62                 goto err_unlock;
  63         }
  64
  65         cl = mei_cl_alloc_linked(dev);
  66         if (IS_ERR(cl)) {
  67                 err = PTR_ERR(cl);
  68                 goto err_unlock;
  69         }
  70
  71         cl->fp = file;
  72         file->private_data = cl;
  73
  74         mutex_unlock(&dev->device_lock);
  75
  76         return nonseekable_open(inode, file);
  77
  78 err_unlock:
  79         mutex_unlock(&dev->device_lock);
  80         return err;
  81 }
  82
  83 /**
  84  * mei_release - the release function
  85  *
  86  * @inode: pointer to inode structure
  87  * @file: pointer to file structure
  88  *
  89  * Return: 0 on success, <0 on error
  90  */
  91 static int mei_release(struct inode *inode, struct file *file)
  92 {
  93         struct mei_cl *cl = file->private_data;
  94         struct mei_device *dev;
  95         int rets;
  96
  97         if (WARN_ON(!cl || !cl->dev))
  98                 return -ENODEV;
  99
 100         dev = cl->dev;
 101
 102         mutex_lock(&dev->device_lock);
 103
 104         rets = mei_cl_disconnect(cl);
 105
 106         mei_cl_flush_queues(cl, file);
 107         cl_dbg(dev, cl, "removing\n");
 108
 109         mei_cl_unlink(cl);
 110
 111         file->private_data = NULL;
 112
 113         kfree(cl);
 114
 115         mutex_unlock(&dev->device_lock);
 116         return rets;
 117 }
 118
 119
 120 /**
 121  * mei_read - the read function.
 122  *
 123  * @file: pointer to file structure
 124  * @ubuf: pointer to user buffer
 125  * @length: buffer length
 126  * @offset: data offset in buffer
 127  *
 128  * Return: >=0 data length on success , <0 on error
 129  */
 130 static ssize_t mei_read(struct file *file, char __user *ubuf,
 131                         size_t length, loff_t *offset)
 132 {
 133         struct mei_cl *cl = file->private_data;
 134         struct mei_device *dev;
 135         struct mei_cl_cb *cb = NULL;
 136         bool nonblock = !!(file->f_flags & O_NONBLOCK);
 137         ssize_t rets;
 138
 139         if (WARN_ON(!cl || !cl->dev))
 140                 return -ENODEV;
 141
 142         dev = cl->dev;
 143
 144
 145         mutex_lock(&dev->device_lock);
 146         if (dev->dev_state != MEI_DEV_ENABLED) {
 147                 rets = -ENODEV;
 148                 goto out;
 149         }
 150
 151         if (length == 0) {
 152                 rets = 0;
 153                 goto out;
 154         }
 155
 156         if (ubuf == NULL) {
 157                 rets = -EMSGSIZE;
 158                 goto out;
 159         }
 160
 161         cb = mei_cl_read_cb(cl, file);
 162         if (cb)
 163                 goto copy_buffer;
 164
 165         if (*offset > 0)
 166                 *offset = 0;
 167
 168         rets = mei_cl_read_start(cl, length, file);
 169         if (rets && rets != -EBUSY) {
 170                 cl_dbg(dev, cl, "mei start read failure status = %zd\n", rets);
 171                 goto out;
 172         }
 173
 174         if (nonblock) {
 175                 rets = -EAGAIN;
 176                 goto out;
 177         }
 178
 179         mutex_unlock(&dev->device_lock);
 180         if (wait_event_interruptible(cl->rx_wait,
 181                                      !list_empty(&cl->rd_completed) ||
 182                                      !mei_cl_is_connected(cl))) {
 183                 if (signal_pending(current))
 184                         return -EINTR;
 185                 return -ERESTARTSYS;
 186         }
 187         mutex_lock(&dev->device_lock);
 188
 189         if (!mei_cl_is_connected(cl)) {
 190                 rets = -ENODEV;
 191                 goto out;
 192         }
 193
 194         cb = mei_cl_read_cb(cl, file);
 195         if (!cb) {
 196                 rets = 0;
 197                 goto out;
 198         }
 199
 200 copy_buffer:
 201         /* now copy the data to user space */
 202         if (cb->status) {
 203                 rets = cb->status;
 204                 cl_dbg(dev, cl, "read operation failed %zd\n", rets);
 205                 goto free;
 206         }
 207
 208         cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n",
 209                cb->buf.size, cb->buf_idx, *offset);
 210         if (*offset >= cb->buf_idx) {
 211                 rets = 0;
 212                 goto free;
 213         }
 214
 215         /* length is being truncated to PAGE_SIZE,
 216          * however buf_idx may point beyond that */
 217         length = min_t(size_t, length, cb->buf_idx - *offset);
 218
 219         if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
 220                 dev_dbg(dev->dev, "failed to copy data to userland\n");
 221                 rets = -EFAULT;
 222                 goto free;
 223         }
 224
 225         rets = length;
 226         *offset += length;
 227         /* not all data was read, keep the cb */
 228         if (*offset < cb->buf_idx)
 229                 goto out;
 230
 231 free:
 232         mei_io_cb_free(cb);
 233         *offset = 0;
 234
 235 out:
 236         cl_dbg(dev, cl, "end mei read rets = %zd\n", rets);
 237         mutex_unlock(&dev->device_lock);
 238         return rets;
 239 }
 240 /**
 241  * mei_write - the write function.
 242  *
 243  * @file: pointer to file structure
 244  * @ubuf: pointer to user buffer
 245  * @length: buffer length
 246  * @offset: data offset in buffer
 247  *
 248  * Return: >=0 data length on success , <0 on error
 249  */
 250 static ssize_t mei_write(struct file *file, const char __user *ubuf,
 251                          size_t length, loff_t *offset)
 252 {
 253         struct mei_cl *cl = file->private_data;
 254         struct mei_cl_cb *cb;
 255         struct mei_device *dev;
 256         ssize_t rets;
 257
 258         if (WARN_ON(!cl || !cl->dev))
 259                 return -ENODEV;
 260
 261         dev = cl->dev;
 262
 263         mutex_lock(&dev->device_lock);
 264
 265         if (dev->dev_state != MEI_DEV_ENABLED) {
 266                 rets = -ENODEV;
 267                 goto out;
 268         }
 269
 270         if (!mei_cl_is_connected(cl)) {
 271                 cl_err(dev, cl, "is not connected");
 272                 rets = -ENODEV;
 273                 goto out;
 274         }
 275
 276         if (!mei_me_cl_is_active(cl->me_cl)) {
 277                 rets = -ENOTTY;
 278                 goto out;
 279         }
 280
 281         if (length > mei_cl_mtu(cl)) {
 282                 rets = -EFBIG;
 283                 goto out;
 284         }
 285
 286         if (length == 0) {
 287                 rets = 0;
 288                 goto out;
 289         }
 290
 291         while (cl->tx_cb_queued >= dev->tx_queue_limit) {
 292                 if (file->f_flags & O_NONBLOCK) {
 293                         rets = -EAGAIN;
 294                         goto out;
 295                 }
 296                 mutex_unlock(&dev->device_lock);
 297                 rets = wait_event_interruptible(cl->tx_wait,
 298                                 cl->writing_state == MEI_WRITE_COMPLETE ||
 299                                 (!mei_cl_is_connected(cl)));
 300                 mutex_lock(&dev->device_lock);
 301                 if (rets) {
 302                         if (signal_pending(current))
 303                                 rets = -EINTR;
 304                         goto out;
 305                 }
 306                 if (!mei_cl_is_connected(cl)) {
 307                         rets = -ENODEV;
 308                         goto out;
 309                 }
 310         }
 311
 312         cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
 313         if (!cb) {
 314                 rets = -ENOMEM;
 315                 goto out;
 316         }
 317
 318         rets = copy_from_user(cb->buf.data, ubuf, length);
 319         if (rets) {
 320                 dev_dbg(dev->dev, "failed to copy data from userland\n");
 321                 rets = -EFAULT;
 322                 mei_io_cb_free(cb);
 323                 goto out;
 324         }
 325
 326         rets = mei_cl_write(cl, cb);
 327 out:
 328         mutex_unlock(&dev->device_lock);
 329         return rets;
 330 }
 331
 332 /**
 333  * mei_ioctl_connect_client - the connect to fw client IOCTL function
 334  *
 335  * @file: private data of the file object
 336  * @data: IOCTL connect data, input and output parameters
 337  *
 338  * Locking: called under "dev->device_lock" lock
 339  *
 340  * Return: 0 on success, <0 on failure.
 341  */
 342 static int mei_ioctl_connect_client(struct file *file,
 343                         struct mei_connect_client_data *data)
 344 {
 345         struct mei_device *dev;
 346         struct mei_client *client;
 347         struct mei_me_client *me_cl;
 348         struct mei_cl *cl;
 349         int rets;
 350
 351         cl = file->private_data;
 352         dev = cl->dev;
 353
 354         if (dev->dev_state != MEI_DEV_ENABLED)
 355                 return -ENODEV;
 356
 357         if (cl->state != MEI_FILE_INITIALIZING &&
 358             cl->state != MEI_FILE_DISCONNECTED)
 359                 return  -EBUSY;
 360
 361         /* find ME client we're trying to connect to */
 362         me_cl = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
 363         if (!me_cl) {
 364                 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
 365                         &data->in_client_uuid);
 366                 rets = -ENOTTY;
 367                 goto end;
 368         }
 369
 370         if (me_cl->props.fixed_address) {
 371                 bool forbidden = dev->override_fixed_address ?
 372                          !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
 373                 if (forbidden) {
 374                         dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
 375                                 &data->in_client_uuid);
 376                         rets = -ENOTTY;
 377                         goto end;
 378                 }
 379         }
 380
 381         dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
 382                         me_cl->client_id);
 383         dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
 384                         me_cl->props.protocol_version);
 385         dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
 386                         me_cl->props.max_msg_length);
 387
 388         /* prepare the output buffer */
 389         client = &data->out_client_properties;
 390         client->max_msg_length = me_cl->props.max_msg_length;
 391         client->protocol_version = me_cl->props.protocol_version;
 392         dev_dbg(dev->dev, "Can connect?\n");
 393
 394         rets = mei_cl_connect(cl, me_cl, file);
 395
 396 end:
 397         mei_me_cl_put(me_cl);
 398         return rets;
 399 }
 400
 401 /**
 402  * mei_ioctl_client_notify_request -
 403  *     propagate event notification request to client
 404  *
 405  * @file: pointer to file structure
 406  * @request: 0 - disable, 1 - enable
 407  *
 408  * Return: 0 on success , <0 on error
 409  */
 410 static int mei_ioctl_client_notify_request(const struct file *file, u32 request)
 411 {
 412         struct mei_cl *cl = file->private_data;
 413
 414         if (request != MEI_HBM_NOTIFICATION_START &&
 415             request != MEI_HBM_NOTIFICATION_STOP)
 416                 return -EINVAL;
 417
 418         return mei_cl_notify_request(cl, file, (u8)request);
 419 }
 420
 421 /**
 422  * mei_ioctl_client_notify_get -  wait for notification request
 423  *
 424  * @file: pointer to file structure
 425  * @notify_get: 0 - disable, 1 - enable
 426  *
 427  * Return: 0 on success , <0 on error
 428  */
 429 static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get)
 430 {
 431         struct mei_cl *cl = file->private_data;
 432         bool notify_ev;
 433         bool block = (file->f_flags & O_NONBLOCK) == 0;
 434         int rets;
 435
 436         rets = mei_cl_notify_get(cl, block, &notify_ev);
 437         if (rets)
 438                 return rets;
 439
 440         *notify_get = notify_ev ? 1 : 0;
 441         return 0;
 442 }
 443
 444 /**
 445  * mei_ioctl - the IOCTL function
 446  *
 447  * @file: pointer to file structure
 448  * @cmd: ioctl command
 449  * @data: pointer to mei message structure
 450  *
 451  * Return: 0 on success , <0 on error
 452  */
 453 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
 454 {
 455         struct mei_device *dev;
 456         struct mei_cl *cl = file->private_data;
 457         struct mei_connect_client_data connect_data;
 458         u32 notify_get, notify_req;
 459         int rets;
 460
 461
 462         if (WARN_ON(!cl || !cl->dev))
 463                 return -ENODEV;
 464
 465         dev = cl->dev;
 466
 467         dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
 468
 469         mutex_lock(&dev->device_lock);
 470         if (dev->dev_state != MEI_DEV_ENABLED) {
 471                 rets = -ENODEV;
 472                 goto out;
 473         }
 474
 475         switch (cmd) {
 476         case IOCTL_MEI_CONNECT_CLIENT:
 477                 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
 478                 if (copy_from_user(&connect_data, (char __user *)data,
 479                                 sizeof(struct mei_connect_client_data))) {
 480                         dev_dbg(dev->dev, "failed to copy data from userland\n");
 481                         rets = -EFAULT;
 482                         goto out;
 483                 }
 484
 485                 rets = mei_ioctl_connect_client(file, &connect_data);
 486                 if (rets)
 487                         goto out;
 488
 489                 /* if all is ok, copying the data back to user. */
 490                 if (copy_to_user((char __user *)data, &connect_data,
 491                                 sizeof(struct mei_connect_client_data))) {
 492                         dev_dbg(dev->dev, "failed to copy data to userland\n");
 493                         rets = -EFAULT;
 494                         goto out;
 495                 }
 496
 497                 break;
 498
 499         case IOCTL_MEI_NOTIFY_SET:
 500                 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
 501                 if (copy_from_user(&notify_req,
 502                                    (char __user *)data, sizeof(notify_req))) {
 503                         dev_dbg(dev->dev, "failed to copy data from userland\n");
 504                         rets = -EFAULT;
 505                         goto out;
 506                 }
 507                 rets = mei_ioctl_client_notify_request(file, notify_req);
 508                 break;
 509
 510         case IOCTL_MEI_NOTIFY_GET:
 511                 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
 512                 rets = mei_ioctl_client_notify_get(file, &notify_get);
 513                 if (rets)
 514                         goto out;
 515
 516                 dev_dbg(dev->dev, "copy connect data to user\n");
 517                 if (copy_to_user((char __user *)data,
 518                                 &notify_get, sizeof(notify_get))) {
 519                         dev_dbg(dev->dev, "failed to copy data to userland\n");
 520                         rets = -EFAULT;
 521                         goto out;
 522
 523                 }
 524                 break;
 525
 526         default:
 527                 rets = -ENOIOCTLCMD;
 528         }
 529
 530 out:
 531         mutex_unlock(&dev->device_lock);
 532         return rets;
 533 }
 534
 535 /**
 536  * mei_poll - the poll function
 537  *
 538  * @file: pointer to file structure
 539  * @wait: pointer to poll_table structure
 540  *
 541  * Return: poll mask
 542  */
 543 static __poll_t mei_poll(struct file *file, poll_table *wait)
 544 {
 545         __poll_t req_events = poll_requested_events(wait);
 546         struct mei_cl *cl = file->private_data;
 547         struct mei_device *dev;
 548         __poll_t mask = 0;
 549         bool notify_en;
 550
 551         if (WARN_ON(!cl || !cl->dev))
 552                 return EPOLLERR;
 553
 554         dev = cl->dev;
 555
 556         mutex_lock(&dev->device_lock);
 557
 558         notify_en = cl->notify_en && (req_events & EPOLLPRI);
 559
 560         if (dev->dev_state != MEI_DEV_ENABLED ||
 561             !mei_cl_is_connected(cl)) {
 562                 mask = EPOLLERR;
 563                 goto out;
 564         }
 565
 566         if (notify_en) {
 567                 poll_wait(file, &cl->ev_wait, wait);
 568                 if (cl->notify_ev)
 569                         mask |= EPOLLPRI;
 570         }
 571
 572         if (req_events & (EPOLLIN | EPOLLRDNORM)) {
 573                 poll_wait(file, &cl->rx_wait, wait);
 574
 575                 if (!list_empty(&cl->rd_completed))
 576                         mask |= EPOLLIN | EPOLLRDNORM;
 577                 else
 578                         mei_cl_read_start(cl, mei_cl_mtu(cl), file);
 579         }
 580
 581         if (req_events & (EPOLLOUT | EPOLLWRNORM)) {
 582                 poll_wait(file, &cl->tx_wait, wait);
 583                 if (cl->tx_cb_queued < dev->tx_queue_limit)
 584                         mask |= EPOLLOUT | EPOLLWRNORM;
 585         }
 586
 587 out:
 588         mutex_unlock(&dev->device_lock);
 589         return mask;
 590 }
 591
 592 /**
 593  * mei_cl_is_write_queued - check if the client has pending writes.
 594  *
 595  * @cl: writing host client
 596  *
 597  * Return: true if client is writing, false otherwise.
 598  */
 599 static bool mei_cl_is_write_queued(struct mei_cl *cl)
 600 {
 601         struct mei_device *dev = cl->dev;
 602         struct mei_cl_cb *cb;
 603
 604         list_for_each_entry(cb, &dev->write_list, list)
 605                 if (cb->cl == cl)
 606                         return true;
 607         list_for_each_entry(cb, &dev->write_waiting_list, list)
 608                 if (cb->cl == cl)
 609                         return true;
 610         return false;
 611 }
 612
 613 /**
 614  * mei_fsync - the fsync handler
 615  *
 616  * @fp:       pointer to file structure
 617  * @start:    unused
 618  * @end:      unused
 619  * @datasync: unused
 620  *
 621  * Return: 0 on success, -ENODEV if client is not connected
 622  */
 623 static int mei_fsync(struct file *fp, loff_t start, loff_t end, int datasync)
 624 {
 625         struct mei_cl *cl = fp->private_data;
 626         struct mei_device *dev;
 627         int rets;
 628
 629         if (WARN_ON(!cl || !cl->dev))
 630                 return -ENODEV;
 631
 632         dev = cl->dev;
 633
 634         mutex_lock(&dev->device_lock);
 635
 636         if (dev->dev_state != MEI_DEV_ENABLED || !mei_cl_is_connected(cl)) {
 637                 rets = -ENODEV;
 638                 goto out;
 639         }
 640
 641         while (mei_cl_is_write_queued(cl)) {
 642                 mutex_unlock(&dev->device_lock);
 643                 rets = wait_event_interruptible(cl->tx_wait,
 644                                 cl->writing_state == MEI_WRITE_COMPLETE ||
 645                                 !mei_cl_is_connected(cl));
 646                 mutex_lock(&dev->device_lock);
 647                 if (rets) {
 648                         if (signal_pending(current))
 649                                 rets = -EINTR;
 650                         goto out;
 651                 }
 652                 if (!mei_cl_is_connected(cl)) {
 653                         rets = -ENODEV;
 654                         goto out;
 655                 }
 656         }
 657         rets = 0;
 658 out:
 659         mutex_unlock(&dev->device_lock);
 660         return rets;
 661 }
 662
 663 /**
 664  * mei_fasync - asynchronous io support
 665  *
 666  * @fd: file descriptor
 667  * @file: pointer to file structure
 668  * @band: band bitmap
 669  *
 670  * Return: negative on error,
 671  *         0 if it did no changes,
 672  *         and positive a process was added or deleted
 673  */
 674 static int mei_fasync(int fd, struct file *file, int band)
 675 {
 676
 677         struct mei_cl *cl = file->private_data;
 678
 679         if (!mei_cl_is_connected(cl))
 680                 return -ENODEV;
 681
 682         return fasync_helper(fd, file, band, &cl->ev_async);
 683 }
 684
 685 /**
 686  * trc_show - mei device trc attribute show method
 687  *
 688  * @device: device pointer
 689  * @attr: attribute pointer
 690  * @buf:  char out buffer
 691  *
 692  * Return: number of the bytes printed into buf or error
 693  */
 694 static ssize_t trc_show(struct device *device,
 695                         struct device_attribute *attr, char *buf)
 696 {
 697         struct mei_device *dev = dev_get_drvdata(device);
 698         u32 trc;
 699         int ret;
 700
 701         ret = mei_trc_status(dev, &trc);
 702         if (ret)
 703                 return ret;
 704         return sprintf(buf, "%08X\n", trc);
 705 }
 706 static DEVICE_ATTR_RO(trc);
 707
 708 /**
 709  * fw_status_show - mei device fw_status attribute show method
 710  *
 711  * @device: device pointer
 712  * @attr: attribute pointer
 713  * @buf:  char out buffer
 714  *
 715  * Return: number of the bytes printed into buf or error
 716  */
 717 static ssize_t fw_status_show(struct device *device,
 718                 struct device_attribute *attr, char *buf)
 719 {
 720         struct mei_device *dev = dev_get_drvdata(device);
 721         struct mei_fw_status fw_status;
 722         int err, i;
 723         ssize_t cnt = 0;
 724
 725         mutex_lock(&dev->device_lock);
 726         err = mei_fw_status(dev, &fw_status);
 727         mutex_unlock(&dev->device_lock);
 728         if (err) {
 729                 dev_err(device, "read fw_status error = %d\n", err);
 730                 return err;
 731         }
 732
 733         for (i = 0; i < fw_status.count; i++)
 734                 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
 735                                 fw_status.status[i]);
 736         return cnt;
 737 }
 738 static DEVICE_ATTR_RO(fw_status);
 739
 740 /**
 741  * hbm_ver_show - display HBM protocol version negotiated with FW
 742  *
 743  * @device: device pointer
 744  * @attr: attribute pointer
 745  * @buf:  char out buffer
 746  *
 747  * Return: number of the bytes printed into buf or error
 748  */
 749 static ssize_t hbm_ver_show(struct device *device,
 750                             struct device_attribute *attr, char *buf)
 751 {
 752         struct mei_device *dev = dev_get_drvdata(device);
 753         struct hbm_version ver;
 754
 755         mutex_lock(&dev->device_lock);
 756         ver = dev->version;
 757         mutex_unlock(&dev->device_lock);
 758
 759         return sprintf(buf, "%u.%u\n", ver.major_version, ver.minor_version);
 760 }
 761 static DEVICE_ATTR_RO(hbm_ver);
 762
 763 /**
 764  * hbm_ver_drv_show - display HBM protocol version advertised by driver
 765  *
 766  * @device: device pointer
 767  * @attr: attribute pointer
 768  * @buf:  char out buffer
 769  *
 770  * Return: number of the bytes printed into buf or error
 771  */
 772 static ssize_t hbm_ver_drv_show(struct device *device,
 773                                 struct device_attribute *attr, char *buf)
 774 {
 775         return sprintf(buf, "%u.%u\n", HBM_MAJOR_VERSION, HBM_MINOR_VERSION);
 776 }
 777 static DEVICE_ATTR_RO(hbm_ver_drv);
 778
 779 static ssize_t tx_queue_limit_show(struct device *device,
 780                                    struct device_attribute *attr, char *buf)
 781 {
 782         struct mei_device *dev = dev_get_drvdata(device);
 783         u8 size = 0;
 784
 785         mutex_lock(&dev->device_lock);
 786         size = dev->tx_queue_limit;
 787         mutex_unlock(&dev->device_lock);
 788
 789         return snprintf(buf, PAGE_SIZE, "%u\n", size);
 790 }
 791
 792 static ssize_t tx_queue_limit_store(struct device *device,
 793                                     struct device_attribute *attr,
 794                                     const char *buf, size_t count)
 795 {
 796         struct mei_device *dev = dev_get_drvdata(device);
 797         u8 limit;
 798         unsigned int inp;
 799         int err;
 800
 801         err = kstrtouint(buf, 10, &inp);
 802         if (err)
 803                 return err;
 804         if (inp > MEI_TX_QUEUE_LIMIT_MAX || inp < MEI_TX_QUEUE_LIMIT_MIN)
 805                 return -EINVAL;
 806         limit = inp;
 807
 808         mutex_lock(&dev->device_lock);
 809         dev->tx_queue_limit = limit;
 810         mutex_unlock(&dev->device_lock);
 811
 812         return count;
 813 }
 814 static DEVICE_ATTR_RW(tx_queue_limit);
 815
 816 /**
 817  * fw_ver_show - display ME FW version
 818  *
 819  * @device: device pointer
 820  * @attr: attribute pointer
 821  * @buf:  char out buffer
 822  *
 823  * Return: number of the bytes printed into buf or error
 824  */
 825 static ssize_t fw_ver_show(struct device *device,
 826                            struct device_attribute *attr, char *buf)
 827 {
 828         struct mei_device *dev = dev_get_drvdata(device);
 829         struct mei_fw_version *ver;
 830         ssize_t cnt = 0;
 831         int i;
 832
 833         ver = dev->fw_ver;
 834
 835         for (i = 0; i < MEI_MAX_FW_VER_BLOCKS; i++)
 836                 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%u:%u.%u.%u.%u\n",
 837                                  ver[i].platform, ver[i].major, ver[i].minor,
 838                                  ver[i].hotfix, ver[i].buildno);
 839         return cnt;
 840 }
 841 static DEVICE_ATTR_RO(fw_ver);
 842
 843 /**
 844  * dev_state_show - display device state
 845  *
 846  * @device: device pointer
 847  * @attr: attribute pointer
 848  * @buf:  char out buffer
 849  *
 850  * Return: number of the bytes printed into buf or error
 851  */
 852 static ssize_t dev_state_show(struct device *device,
 853                               struct device_attribute *attr, char *buf)
 854 {
 855         struct mei_device *dev = dev_get_drvdata(device);
 856         enum mei_dev_state dev_state;
 857
 858         mutex_lock(&dev->device_lock);
 859         dev_state = dev->dev_state;
 860         mutex_unlock(&dev->device_lock);
 861
 862         return sprintf(buf, "%s", mei_dev_state_str(dev_state));
 863 }
 864 static DEVICE_ATTR_RO(dev_state);
 865
 866 /**
 867  * dev_set_devstate: set to new device state and notify sysfs file.
 868  *
 869  * @dev: mei_device
 870  * @state: new device state
 871  */
 872 void mei_set_devstate(struct mei_device *dev, enum mei_dev_state state)
 873 {
 874         struct device *clsdev;
 875
 876         if (dev->dev_state == state)
 877                 return;
 878
 879         dev->dev_state = state;
 880
 881         clsdev = class_find_device_by_devt(mei_class, dev->cdev.dev);
 882         if (clsdev) {
 883                 sysfs_notify(&clsdev->kobj, NULL, "dev_state");
 884                 put_device(clsdev);
 885         }
 886 }
 887
 888 static struct attribute *mei_attrs[] = {
 889         &dev_attr_fw_status.attr,
 890         &dev_attr_hbm_ver.attr,
 891         &dev_attr_hbm_ver_drv.attr,
 892         &dev_attr_tx_queue_limit.attr,
 893         &dev_attr_fw_ver.attr,
 894         &dev_attr_dev_state.attr,
 895         &dev_attr_trc.attr,
 896         NULL
 897 };
 898 ATTRIBUTE_GROUPS(mei);
 899
 900 /*
 901  * file operations structure will be used for mei char device.
 902  */
 903 static const struct file_operations mei_fops = {
 904         .owner = THIS_MODULE,
 905         .read = mei_read,
 906         .unlocked_ioctl = mei_ioctl,
 907         .compat_ioctl = compat_ptr_ioctl,
 908         .open = mei_open,
 909         .release = mei_release,
 910         .write = mei_write,
 911         .poll = mei_poll,
 912         .fsync = mei_fsync,
 913         .fasync = mei_fasync,
 914         .llseek = no_llseek
 915 };
 916
 917 /**
 918  * mei_minor_get - obtain next free device minor number
 919  *
 920  * @dev:  device pointer
 921  *
 922  * Return: allocated minor, or -ENOSPC if no free minor left
 923  */
 924 static int mei_minor_get(struct mei_device *dev)
 925 {
 926         int ret;
 927
 928         mutex_lock(&mei_minor_lock);
 929         ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
 930         if (ret >= 0)
 931                 dev->minor = ret;
 932         else if (ret == -ENOSPC)
 933                 dev_err(dev->dev, "too many mei devices\n");
 934
 935         mutex_unlock(&mei_minor_lock);
 936         return ret;
 937 }
 938
 939 /**
 940  * mei_minor_free - mark device minor number as free
 941  *
 942  * @dev:  device pointer
 943  */
 944 static void mei_minor_free(struct mei_device *dev)
 945 {
 946         mutex_lock(&mei_minor_lock);
 947         idr_remove(&mei_idr, dev->minor);
 948         mutex_unlock(&mei_minor_lock);
 949 }
 950
 951 int mei_register(struct mei_device *dev, struct device *parent)
 952 {
 953         struct device *clsdev; /* class device */
 954         int ret, devno;
 955
 956         ret = mei_minor_get(dev);
 957         if (ret < 0)
 958                 return ret;
 959
 960         /* Fill in the data structures */
 961         devno = MKDEV(MAJOR(mei_devt), dev->minor);
 962         cdev_init(&dev->cdev, &mei_fops);
 963         dev->cdev.owner = parent->driver->owner;
 964
 965         /* Add the device */
 966         ret = cdev_add(&dev->cdev, devno, 1);
 967         if (ret) {
 968                 dev_err(parent, "unable to add device %d:%d\n",
 969                         MAJOR(mei_devt), dev->minor);
 970                 goto err_dev_add;
 971         }
 972
 973         clsdev = device_create_with_groups(mei_class, parent, devno,
 974                                            dev, mei_groups,
 975                                            "mei%d", dev->minor);
 976
 977         if (IS_ERR(clsdev)) {
 978                 dev_err(parent, "unable to create device %d:%d\n",
 979                         MAJOR(mei_devt), dev->minor);
 980                 ret = PTR_ERR(clsdev);
 981                 goto err_dev_create;
 982         }
 983
 984         mei_dbgfs_register(dev, dev_name(clsdev));
 985
 986         return 0;
 987
 988 err_dev_create:
 989         cdev_del(&dev->cdev);
 990 err_dev_add:
 991         mei_minor_free(dev);
 992         return ret;
 993 }
 994 EXPORT_SYMBOL_GPL(mei_register);
 995
 996 void mei_deregister(struct mei_device *dev)
 997 {
 998         int devno;
 999
1000         devno = dev->cdev.dev;
1001         cdev_del(&dev->cdev);
1002
1003         mei_dbgfs_deregister(dev);
1004
1005         device_destroy(mei_class, devno);
1006
1007         mei_minor_free(dev);
1008 }
1009 EXPORT_SYMBOL_GPL(mei_deregister);
1010
1011 static int __init mei_init(void)
1012 {
1013         int ret;
1014
1015         mei_class = class_create(THIS_MODULE, "mei");
1016         if (IS_ERR(mei_class)) {
1017                 pr_err("couldn't create class\n");
1018                 ret = PTR_ERR(mei_class);
1019                 goto err;
1020         }
1021
1022         ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
1023         if (ret < 0) {
1024                 pr_err("unable to allocate char dev region\n");
1025                 goto err_class;
1026         }
1027
1028         ret = mei_cl_bus_init();
1029         if (ret < 0) {
1030                 pr_err("unable to initialize bus\n");
1031                 goto err_chrdev;
1032         }
1033
1034         return 0;
1035
1036 err_chrdev:
1037         unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
1038 err_class:
1039         class_destroy(mei_class);
1040 err:
1041         return ret;
1042 }
1043
1044 static void __exit mei_exit(void)
1045 {
1046         unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
1047         class_destroy(mei_class);
1048         mei_cl_bus_exit();
1049 }
1050
1051 module_init(mei_init);
1052 module_exit(mei_exit);
1053
1054 MODULE_AUTHOR("Intel Corporation");
1055 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
1056 MODULE_LICENSE("GPL v2");
1057