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