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