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
  17 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  18
  19 #include <linux/module.h>
  20 #include <linux/moduleparam.h>
  21 #include <linux/kernel.h>
  22 #include <linux/device.h>
  23 #include <linux/fs.h>
  24 #include <linux/errno.h>
  25 #include <linux/types.h>
  26 #include <linux/fcntl.h>
  27 #include <linux/aio.h>
  28 #include <linux/pci.h>
  29 #include <linux/poll.h>
  30 #include <linux/init.h>
  31 #include <linux/ioctl.h>
  32 #include <linux/cdev.h>
  33 #include <linux/sched.h>
  34 #include <linux/uuid.h>
  35 #include <linux/compat.h>
  36 #include <linux/jiffies.h>
  37 #include <linux/interrupt.h>
  38 #include <linux/miscdevice.h>
  39
  40 #include <linux/mei.h>
  41
  42 #include "mei_dev.h"
  43 #include "hw-me.h"
  44 #include "client.h"
  45
  46 /**
  47  * mei_open - the open function
  48  *
  49  * @inode: pointer to inode structure
  50  * @file: pointer to file structure
  51  *
  52  * returns 0 on success, <0 on error
  53  */
  54 static int mei_open(struct inode *inode, struct file *file)
  55 {
  56         struct miscdevice *misc = file->private_data;
  57         struct pci_dev *pdev;
  58         struct mei_cl *cl;
  59         struct mei_device *dev;
  60
  61         int err;
  62
  63         if (!misc->parent)
  64                 return -ENODEV;
  65
  66         pdev = container_of(misc->parent, struct pci_dev, dev);
  67
  68         dev = pci_get_drvdata(pdev);
  69         if (!dev)
  70                 return -ENODEV;
  71
  72         mutex_lock(&dev->device_lock);
  73
  74         cl = NULL;
  75
  76         err = -ENODEV;
  77         if (dev->dev_state != MEI_DEV_ENABLED) {
  78                 dev_dbg(&dev->pdev->dev, "dev_state != MEI_ENABLED  dev_state = %s\n",
  79                     mei_dev_state_str(dev->dev_state));
  80                 goto err_unlock;
  81         }
  82
  83         err = -ENOMEM;
  84         cl = mei_cl_allocate(dev);
  85         if (!cl)
  86                 goto err_unlock;
  87
  88         /* open_handle_count check is handled in the mei_cl_link */
  89         err = mei_cl_link(cl, MEI_HOST_CLIENT_ID_ANY);
  90         if (err)
  91                 goto err_unlock;
  92
  93         file->private_data = cl;
  94
  95         mutex_unlock(&dev->device_lock);
  96
  97         return nonseekable_open(inode, file);
  98
  99 err_unlock:
 100         mutex_unlock(&dev->device_lock);
 101         kfree(cl);
 102         return err;
 103 }
 104
 105 /**
 106  * mei_release - the release function
 107  *
 108  * @inode: pointer to inode structure
 109  * @file: pointer to file structure
 110  *
 111  * returns 0 on success, <0 on error
 112  */
 113 static int mei_release(struct inode *inode, struct file *file)
 114 {
 115         struct mei_cl *cl = file->private_data;
 116         struct mei_cl_cb *cb;
 117         struct mei_device *dev;
 118         int rets = 0;
 119
 120         if (WARN_ON(!cl || !cl->dev))
 121                 return -ENODEV;
 122
 123         dev = cl->dev;
 124
 125         mutex_lock(&dev->device_lock);
 126         if (cl == &dev->iamthif_cl) {
 127                 rets = mei_amthif_release(dev, file);
 128                 goto out;
 129         }
 130         if (cl->state == MEI_FILE_CONNECTED) {
 131                 cl->state = MEI_FILE_DISCONNECTING;
 132                 dev_dbg(&dev->pdev->dev,
 133                         "disconnecting client host client = %d, "
 134                     "ME client = %d\n",
 135                     cl->host_client_id,
 136                     cl->me_client_id);
 137                 rets = mei_cl_disconnect(cl);
 138         }
 139         mei_cl_flush_queues(cl);
 140         dev_dbg(&dev->pdev->dev, "remove client host client = %d, ME client = %d\n",
 141             cl->host_client_id,
 142             cl->me_client_id);
 143
 144         mei_cl_unlink(cl);
 145
 146
 147         /* free read cb */
 148         cb = NULL;
 149         if (cl->read_cb) {
 150                 cb = mei_cl_find_read_cb(cl);
 151                 /* Remove entry from read list */
 152                 if (cb)
 153                         list_del(&cb->list);
 154
 155                 cb = cl->read_cb;
 156                 cl->read_cb = NULL;
 157         }
 158
 159         file->private_data = NULL;
 160
 161         mei_io_cb_free(cb);
 162
 163         kfree(cl);
 164 out:
 165         mutex_unlock(&dev->device_lock);
 166         return rets;
 167 }
 168
 169
 170 /**
 171  * mei_read - the read function.
 172  *
 173  * @file: pointer to file structure
 174  * @ubuf: pointer to user buffer
 175  * @length: buffer length
 176  * @offset: data offset in buffer
 177  *
 178  * returns >=0 data length on success , <0 on error
 179  */
 180 static ssize_t mei_read(struct file *file, char __user *ubuf,
 181                         size_t length, loff_t *offset)
 182 {
 183         struct mei_cl *cl = file->private_data;
 184         struct mei_cl_cb *cb_pos = NULL;
 185         struct mei_cl_cb *cb = NULL;
 186         struct mei_device *dev;
 187         int rets;
 188         int err;
 189
 190
 191         if (WARN_ON(!cl || !cl->dev))
 192                 return -ENODEV;
 193
 194         dev = cl->dev;
 195
 196
 197         mutex_lock(&dev->device_lock);
 198         if (dev->dev_state != MEI_DEV_ENABLED) {
 199                 rets = -ENODEV;
 200                 goto out;
 201         }
 202
 203         if (length == 0) {
 204                 rets = 0;
 205                 goto out;
 206         }
 207
 208         if (cl == &dev->iamthif_cl) {
 209                 rets = mei_amthif_read(dev, file, ubuf, length, offset);
 210                 goto out;
 211         }
 212
 213         if (cl->read_cb) {
 214                 cb = cl->read_cb;
 215                 /* read what left */
 216                 if (cb->buf_idx > *offset)
 217                         goto copy_buffer;
 218                 /* offset is beyond buf_idx we have no more data return 0 */
 219                 if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
 220                         rets = 0;
 221                         goto free;
 222                 }
 223                 /* Offset needs to be cleaned for contiguous reads*/
 224                 if (cb->buf_idx == 0 && *offset > 0)
 225                         *offset = 0;
 226         } else if (*offset > 0) {
 227                 *offset = 0;
 228         }
 229
 230         err = mei_cl_read_start(cl, length);
 231         if (err && err != -EBUSY) {
 232                 dev_dbg(&dev->pdev->dev,
 233                         "mei start read failure with status = %d\n", err);
 234                 rets = err;
 235                 goto out;
 236         }
 237
 238         if (MEI_READ_COMPLETE != cl->reading_state &&
 239                         !waitqueue_active(&cl->rx_wait)) {
 240                 if (file->f_flags & O_NONBLOCK) {
 241                         rets = -EAGAIN;
 242                         goto out;
 243                 }
 244
 245                 mutex_unlock(&dev->device_lock);
 246
 247                 if (wait_event_interruptible(cl->rx_wait,
 248                                 MEI_READ_COMPLETE == cl->reading_state ||
 249                                 mei_cl_is_transitioning(cl))) {
 250
 251                         if (signal_pending(current))
 252                                 return -EINTR;
 253                         return -ERESTARTSYS;
 254                 }
 255
 256                 mutex_lock(&dev->device_lock);
 257                 if (mei_cl_is_transitioning(cl)) {
 258                         rets = -EBUSY;
 259                         goto out;
 260                 }
 261         }
 262
 263         cb = cl->read_cb;
 264
 265         if (!cb) {
 266                 rets = -ENODEV;
 267                 goto out;
 268         }
 269         if (cl->reading_state != MEI_READ_COMPLETE) {
 270                 rets = 0;
 271                 goto out;
 272         }
 273         /* now copy the data to user space */
 274 copy_buffer:
 275         dev_dbg(&dev->pdev->dev, "buf.size = %d buf.idx= %ld\n",
 276             cb->response_buffer.size, cb->buf_idx);
 277         if (length == 0 || ubuf == NULL || *offset > cb->buf_idx) {
 278                 rets = -EMSGSIZE;
 279                 goto free;
 280         }
 281
 282         /* length is being truncated to PAGE_SIZE,
 283          * however buf_idx may point beyond that */
 284         length = min_t(size_t, length, cb->buf_idx - *offset);
 285
 286         if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length)) {
 287                 rets = -EFAULT;
 288                 goto free;
 289         }
 290
 291         rets = length;
 292         *offset += length;
 293         if ((unsigned long)*offset < cb->buf_idx)
 294                 goto out;
 295
 296 free:
 297         cb_pos = mei_cl_find_read_cb(cl);
 298         /* Remove entry from read list */
 299         if (cb_pos)
 300                 list_del(&cb_pos->list);
 301         mei_io_cb_free(cb);
 302         cl->reading_state = MEI_IDLE;
 303         cl->read_cb = NULL;
 304 out:
 305         dev_dbg(&dev->pdev->dev, "end mei read rets= %d\n", rets);
 306         mutex_unlock(&dev->device_lock);
 307         return rets;
 308 }
 309 /**
 310  * mei_write - the write function.
 311  *
 312  * @file: pointer to file structure
 313  * @ubuf: pointer to user buffer
 314  * @length: buffer length
 315  * @offset: data offset in buffer
 316  *
 317  * returns >=0 data length on success , <0 on error
 318  */
 319 static ssize_t mei_write(struct file *file, const char __user *ubuf,
 320                          size_t length, loff_t *offset)
 321 {
 322         struct mei_cl *cl = file->private_data;
 323         struct mei_cl_cb *write_cb = NULL;
 324         struct mei_device *dev;
 325         unsigned long timeout = 0;
 326         int rets;
 327         int id;
 328
 329         if (WARN_ON(!cl || !cl->dev))
 330                 return -ENODEV;
 331
 332         dev = cl->dev;
 333
 334         mutex_lock(&dev->device_lock);
 335
 336         if (dev->dev_state != MEI_DEV_ENABLED) {
 337                 rets = -ENODEV;
 338                 goto out;
 339         }
 340
 341         id = mei_me_cl_by_id(dev, cl->me_client_id);
 342         if (id < 0) {
 343                 rets = -ENODEV;
 344                 goto out;
 345         }
 346
 347         if (length == 0) {
 348                 rets = 0;
 349                 goto out;
 350         }
 351
 352         if (length > dev->me_clients[id].props.max_msg_length) {
 353                 rets = -EFBIG;
 354                 goto out;
 355         }
 356
 357         if (cl->state != MEI_FILE_CONNECTED) {
 358                 dev_err(&dev->pdev->dev, "host client = %d,  is not connected to ME client = %d",
 359                         cl->host_client_id, cl->me_client_id);
 360                 rets = -ENODEV;
 361                 goto out;
 362         }
 363         if (cl == &dev->iamthif_cl) {
 364                 write_cb = mei_amthif_find_read_list_entry(dev, file);
 365
 366                 if (write_cb) {
 367                         timeout = write_cb->read_time +
 368                                 mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
 369
 370                         if (time_after(jiffies, timeout) ||
 371                             cl->reading_state == MEI_READ_COMPLETE) {
 372                                 *offset = 0;
 373                                 list_del(&write_cb->list);
 374                                 mei_io_cb_free(write_cb);
 375                                 write_cb = NULL;
 376                         }
 377                 }
 378         }
 379
 380         /* free entry used in read */
 381         if (cl->reading_state == MEI_READ_COMPLETE) {
 382                 *offset = 0;
 383                 write_cb = mei_cl_find_read_cb(cl);
 384                 if (write_cb) {
 385                         list_del(&write_cb->list);
 386                         mei_io_cb_free(write_cb);
 387                         write_cb = NULL;
 388                         cl->reading_state = MEI_IDLE;
 389                         cl->read_cb = NULL;
 390                 }
 391         } else if (cl->reading_state == MEI_IDLE)
 392                 *offset = 0;
 393
 394
 395         write_cb = mei_io_cb_init(cl, file);
 396         if (!write_cb) {
 397                 dev_err(&dev->pdev->dev, "write cb allocation failed\n");
 398                 rets = -ENOMEM;
 399                 goto out;
 400         }
 401         rets = mei_io_cb_alloc_req_buf(write_cb, length);
 402         if (rets)
 403                 goto out;
 404
 405         rets = copy_from_user(write_cb->request_buffer.data, ubuf, length);
 406         if (rets) {
 407                 dev_err(&dev->pdev->dev, "failed to copy data from userland\n");
 408                 rets = -EFAULT;
 409                 goto out;
 410         }
 411
 412         if (cl == &dev->iamthif_cl) {
 413                 rets = mei_amthif_write(dev, write_cb);
 414
 415                 if (rets) {
 416                         dev_err(&dev->pdev->dev,
 417                                 "amthif write failed with status = %d\n", rets);
 418                         goto out;
 419                 }
 420                 mutex_unlock(&dev->device_lock);
 421                 return length;
 422         }
 423
 424         rets = mei_cl_write(cl, write_cb, false);
 425 out:
 426         mutex_unlock(&dev->device_lock);
 427         if (rets < 0)
 428                 mei_io_cb_free(write_cb);
 429         return rets;
 430 }
 431
 432 /**
 433  * mei_ioctl_connect_client - the connect to fw client IOCTL function
 434  *
 435  * @dev: the device structure
 436  * @data: IOCTL connect data, input and output parameters
 437  * @file: private data of the file object
 438  *
 439  * Locking: called under "dev->device_lock" lock
 440  *
 441  * returns 0 on success, <0 on failure.
 442  */
 443 static int mei_ioctl_connect_client(struct file *file,
 444                         struct mei_connect_client_data *data)
 445 {
 446         struct mei_device *dev;
 447         struct mei_client *client;
 448         struct mei_cl *cl;
 449         int i;
 450         int rets;
 451
 452         cl = file->private_data;
 453         if (WARN_ON(!cl || !cl->dev))
 454                 return -ENODEV;
 455
 456         dev = cl->dev;
 457
 458         if (dev->dev_state != MEI_DEV_ENABLED) {
 459                 rets = -ENODEV;
 460                 goto end;
 461         }
 462
 463         if (cl->state != MEI_FILE_INITIALIZING &&
 464             cl->state != MEI_FILE_DISCONNECTED) {
 465                 rets = -EBUSY;
 466                 goto end;
 467         }
 468
 469         /* find ME client we're trying to connect to */
 470         i = mei_me_cl_by_uuid(dev, &data->in_client_uuid);
 471         if (i < 0 || dev->me_clients[i].props.fixed_address) {
 472                 dev_dbg(&dev->pdev->dev, "Cannot connect to FW Client UUID = %pUl\n",
 473                                 &data->in_client_uuid);
 474                 rets = -ENODEV;
 475                 goto end;
 476         }
 477
 478         cl->me_client_id = dev->me_clients[i].client_id;
 479         cl->state = MEI_FILE_CONNECTING;
 480
 481         dev_dbg(&dev->pdev->dev, "Connect to FW Client ID = %d\n",
 482                         cl->me_client_id);
 483         dev_dbg(&dev->pdev->dev, "FW Client - Protocol Version = %d\n",
 484                         dev->me_clients[i].props.protocol_version);
 485         dev_dbg(&dev->pdev->dev, "FW Client - Max Msg Len = %d\n",
 486                         dev->me_clients[i].props.max_msg_length);
 487
 488         /* if we're connecting to amthif client then we will use the
 489          * existing connection
 490          */
 491         if (uuid_le_cmp(data->in_client_uuid, mei_amthif_guid) == 0) {
 492                 dev_dbg(&dev->pdev->dev, "FW Client is amthi\n");
 493                 if (dev->iamthif_cl.state != MEI_FILE_CONNECTED) {
 494                         rets = -ENODEV;
 495                         goto end;
 496                 }
 497                 mei_cl_unlink(cl);
 498
 499                 kfree(cl);
 500                 cl = NULL;
 501                 dev->iamthif_open_count++;
 502                 file->private_data = &dev->iamthif_cl;
 503
 504                 client = &data->out_client_properties;
 505                 client->max_msg_length =
 506                         dev->me_clients[i].props.max_msg_length;
 507                 client->protocol_version =
 508                         dev->me_clients[i].props.protocol_version;
 509                 rets = dev->iamthif_cl.status;
 510
 511                 goto end;
 512         }
 513
 514
 515         /* prepare the output buffer */
 516         client = &data->out_client_properties;
 517         client->max_msg_length = dev->me_clients[i].props.max_msg_length;
 518         client->protocol_version = dev->me_clients[i].props.protocol_version;
 519         dev_dbg(&dev->pdev->dev, "Can connect?\n");
 520
 521
 522         rets = mei_cl_connect(cl, file);
 523
 524 end:
 525         return rets;
 526 }
 527
 528
 529 /**
 530  * mei_ioctl - the IOCTL function
 531  *
 532  * @file: pointer to file structure
 533  * @cmd: ioctl command
 534  * @data: pointer to mei message structure
 535  *
 536  * returns 0 on success , <0 on error
 537  */
 538 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
 539 {
 540         struct mei_device *dev;
 541         struct mei_cl *cl = file->private_data;
 542         struct mei_connect_client_data *connect_data = NULL;
 543         int rets;
 544
 545         if (cmd != IOCTL_MEI_CONNECT_CLIENT)
 546                 return -EINVAL;
 547
 548         if (WARN_ON(!cl || !cl->dev))
 549                 return -ENODEV;
 550
 551         dev = cl->dev;
 552
 553         dev_dbg(&dev->pdev->dev, "IOCTL cmd = 0x%x", cmd);
 554
 555         mutex_lock(&dev->device_lock);
 556         if (dev->dev_state != MEI_DEV_ENABLED) {
 557                 rets = -ENODEV;
 558                 goto out;
 559         }
 560
 561         dev_dbg(&dev->pdev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
 562
 563         connect_data = kzalloc(sizeof(struct mei_connect_client_data),
 564                                                         GFP_KERNEL);
 565         if (!connect_data) {
 566                 rets = -ENOMEM;
 567                 goto out;
 568         }
 569         dev_dbg(&dev->pdev->dev, "copy connect data from user\n");
 570         if (copy_from_user(connect_data, (char __user *)data,
 571                                 sizeof(struct mei_connect_client_data))) {
 572                 dev_err(&dev->pdev->dev, "failed to copy data from userland\n");
 573                 rets = -EFAULT;
 574                 goto out;
 575         }
 576
 577         rets = mei_ioctl_connect_client(file, connect_data);
 578
 579         /* if all is ok, copying the data back to user. */
 580         if (rets)
 581                 goto out;
 582
 583         dev_dbg(&dev->pdev->dev, "copy connect data to user\n");
 584         if (copy_to_user((char __user *)data, connect_data,
 585                                 sizeof(struct mei_connect_client_data))) {
 586                 dev_dbg(&dev->pdev->dev, "failed to copy data to userland\n");
 587                 rets = -EFAULT;
 588                 goto out;
 589         }
 590
 591 out:
 592         kfree(connect_data);
 593         mutex_unlock(&dev->device_lock);
 594         return rets;
 595 }
 596
 597 /**
 598  * mei_compat_ioctl - the compat IOCTL function
 599  *
 600  * @file: pointer to file structure
 601  * @cmd: ioctl command
 602  * @data: pointer to mei message structure
 603  *
 604  * returns 0 on success , <0 on error
 605  */
 606 #ifdef CONFIG_COMPAT
 607 static long mei_compat_ioctl(struct file *file,
 608                         unsigned int cmd, unsigned long data)
 609 {
 610         return mei_ioctl(file, cmd, (unsigned long)compat_ptr(data));
 611 }
 612 #endif
 613
 614
 615 /**
 616  * mei_poll - the poll function
 617  *
 618  * @file: pointer to file structure
 619  * @wait: pointer to poll_table structure
 620  *
 621  * returns poll mask
 622  */
 623 static unsigned int mei_poll(struct file *file, poll_table *wait)
 624 {
 625         struct mei_cl *cl = file->private_data;
 626         struct mei_device *dev;
 627         unsigned int mask = 0;
 628
 629         if (WARN_ON(!cl || !cl->dev))
 630                 return POLLERR;
 631
 632         dev = cl->dev;
 633
 634         mutex_lock(&dev->device_lock);
 635
 636         if (!mei_cl_is_connected(cl)) {
 637                 mask = POLLERR;
 638                 goto out;
 639         }
 640
 641         mutex_unlock(&dev->device_lock);
 642
 643
 644         if (cl == &dev->iamthif_cl)
 645                 return mei_amthif_poll(dev, file, wait);
 646
 647         poll_wait(file, &cl->tx_wait, wait);
 648
 649         mutex_lock(&dev->device_lock);
 650
 651         if (!mei_cl_is_connected(cl)) {
 652                 mask = POLLERR;
 653                 goto out;
 654         }
 655
 656         if (MEI_WRITE_COMPLETE == cl->writing_state)
 657                 mask |= (POLLIN | POLLRDNORM);
 658
 659 out:
 660         mutex_unlock(&dev->device_lock);
 661         return mask;
 662 }
 663
 664 /*
 665  * file operations structure will be used for mei char device.
 666  */
 667 static const struct file_operations mei_fops = {
 668         .owner = THIS_MODULE,
 669         .read = mei_read,
 670         .unlocked_ioctl = mei_ioctl,
 671 #ifdef CONFIG_COMPAT
 672         .compat_ioctl = mei_compat_ioctl,
 673 #endif
 674         .open = mei_open,
 675         .release = mei_release,
 676         .write = mei_write,
 677         .poll = mei_poll,
 678         .llseek = no_llseek
 679 };
 680
 681 /*
 682  * Misc Device Struct
 683  */
 684 static struct miscdevice  mei_misc_device = {
 685                 .name = "mei",
 686                 .fops = &mei_fops,
 687                 .minor = MISC_DYNAMIC_MINOR,
 688 };
 689
 690
 691 int mei_register(struct mei_device *dev)
 692 {
 693         int ret;
 694         mei_misc_device.parent = &dev->pdev->dev;
 695         ret = misc_register(&mei_misc_device);
 696         if (ret)
 697                 return ret;
 698
 699         if (mei_dbgfs_register(dev, mei_misc_device.name))
 700                 dev_err(&dev->pdev->dev, "cannot register debugfs\n");
 701
 702         return 0;
 703 }
 704 EXPORT_SYMBOL_GPL(mei_register);
 705
 706 void mei_deregister(struct mei_device *dev)
 707 {
 708         mei_dbgfs_deregister(dev);
 709         misc_deregister(&mei_misc_device);
 710         mei_misc_device.parent = NULL;
 711 }
 712 EXPORT_SYMBOL_GPL(mei_deregister);
 713
 714 static int __init mei_init(void)
 715 {
 716         return mei_cl_bus_init();
 717 }
 718
 719 static void __exit mei_exit(void)
 720 {
 721         mei_cl_bus_exit();
 722 }
 723
 724 module_init(mei_init);
 725 module_exit(mei_exit);
 726
 727 MODULE_AUTHOR("Intel Corporation");
 728 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
 729 MODULE_LICENSE("GPL v2");
 730