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