drivers/misc/mei/main.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2003-2020, Intel Corporation. All rights reserved.
   4  * Intel Management Engine Interface (Intel MEI) Linux driver
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/moduleparam.h>
   9 #include <linux/kernel.h>
  10 #include <linux/device.h>
  11 #include <linux/slab.h>
  12 #include <linux/fs.h>
  13 #include <linux/errno.h>
  14 #include <linux/types.h>
  15 #include <linux/fcntl.h>
  16 #include <linux/poll.h>
  17 #include <linux/init.h>
  18 #include <linux/ioctl.h>
  19 #include <linux/cdev.h>
  20 #include <linux/sched/signal.h>
  21 #include <linux/uuid.h>
  22 #include <linux/compat.h>
  23 #include <linux/jiffies.h>
  24 #include <linux/interrupt.h>
  25
  26 #include <linux/mei.h>
  27
  28 #include "mei_dev.h"
  29 #include "client.h"
  30
  31 static struct class *mei_class;
  32 static dev_t mei_devt;
  33 #define MEI_MAX_DEVS  MINORMASK
  34 static DEFINE_MUTEX(mei_minor_lock);
  35 static DEFINE_IDR(mei_idr);
  36
  37 /**
  38  * mei_open - the open function
  39  *
  40  * @inode: pointer to inode structure
  41  * @file: pointer to file structure
  42  *
  43  * Return: 0 on success, <0 on error
  44  */
  45 static int mei_open(struct inode *inode, struct file *file)
  46 {
  47         struct mei_device *dev;
  48         struct mei_cl *cl;
  49
  50         int err;
  51
  52         dev = container_of(inode->i_cdev, struct mei_device, cdev);
  53         if (!dev)
  54                 return -ENODEV;
  55
  56         mutex_lock(&dev->device_lock);
  57
  58         if (dev->dev_state != MEI_DEV_ENABLED) {
  59                 dev_dbg(dev->dev, "dev_state != MEI_ENABLED  dev_state = %s\n",
  60                     mei_dev_state_str(dev->dev_state));
  61                 err = -ENODEV;
  62                 goto err_unlock;
  63         }
  64
  65         cl = mei_cl_alloc_linked(dev);
  66         if (IS_ERR(cl)) {
  67                 err = PTR_ERR(cl);
  68                 goto err_unlock;
  69         }
  70
  71         cl->fp = file;
  72         file->private_data = cl;
  73
  74         mutex_unlock(&dev->device_lock);
  75
  76         return nonseekable_open(inode, file);
  77
  78 err_unlock:
  79         mutex_unlock(&dev->device_lock);
  80         return err;
  81 }
  82
  83 /**
  84  * mei_cl_vtag_remove_by_fp - remove vtag that corresponds to fp from list
  85  *
  86  * @cl: host client
  87  * @fp: pointer to file structure
  88  *
  89  */
  90 static void mei_cl_vtag_remove_by_fp(const struct mei_cl *cl,
  91                                      const struct file *fp)
  92 {
  93         struct mei_cl_vtag *vtag_l, *next;
  94
  95         list_for_each_entry_safe(vtag_l, next, &cl->vtag_map, list) {
  96                 if (vtag_l->fp == fp) {
  97                         list_del(&vtag_l->list);
  98                         kfree(vtag_l);
  99                         return;
 100                 }
 101         }
 102 }
 103
 104 /**
 105  * mei_release - the release function
 106  *
 107  * @inode: pointer to inode structure
 108  * @file: pointer to file structure
 109  *
 110  * Return: 0 on success, <0 on error
 111  */
 112 static int mei_release(struct inode *inode, struct file *file)
 113 {
 114         struct mei_cl *cl = file->private_data;
 115         struct mei_device *dev;
 116         int rets;
 117
 118         if (WARN_ON(!cl || !cl->dev))
 119                 return -ENODEV;
 120
 121         dev = cl->dev;
 122
 123         mutex_lock(&dev->device_lock);
 124
 125         mei_cl_vtag_remove_by_fp(cl, file);
 126
 127         if (!list_empty(&cl->vtag_map)) {
 128                 cl_dbg(dev, cl, "not the last vtag\n");
 129                 mei_cl_flush_queues(cl, file);
 130                 rets = 0;
 131                 goto out;
 132         }
 133
 134         rets = mei_cl_disconnect(cl);
 135         /*
 136          * Check again: This is necessary since disconnect releases the lock
 137          * and another client can connect in the meantime.
 138          */
 139         if (!list_empty(&cl->vtag_map)) {
 140                 cl_dbg(dev, cl, "not the last vtag after disconnect\n");
 141                 mei_cl_flush_queues(cl, file);
 142                 goto out;
 143         }
 144
 145         mei_cl_flush_queues(cl, NULL);
 146         cl_dbg(dev, cl, "removing\n");
 147
 148         mei_cl_unlink(cl);
 149         kfree(cl);
 150
 151 out:
 152         file->private_data = NULL;
 153
 154         mutex_unlock(&dev->device_lock);
 155         return rets;
 156 }
 157
 158
 159 /**
 160  * mei_read - the read function.
 161  *
 162  * @file: pointer to file structure
 163  * @ubuf: pointer to user buffer
 164  * @length: buffer length
 165  * @offset: data offset in buffer
 166  *
 167  * Return: >=0 data length on success , <0 on error
 168  */
 169 static ssize_t mei_read(struct file *file, char __user *ubuf,
 170                         size_t length, loff_t *offset)
 171 {
 172         struct mei_cl *cl = file->private_data;
 173         struct mei_device *dev;
 174         struct mei_cl_cb *cb = NULL;
 175         bool nonblock = !!(file->f_flags & O_NONBLOCK);
 176         ssize_t rets;
 177
 178         if (WARN_ON(!cl || !cl->dev))
 179                 return -ENODEV;
 180
 181         dev = cl->dev;
 182
 183
 184         mutex_lock(&dev->device_lock);
 185         if (dev->dev_state != MEI_DEV_ENABLED) {
 186                 rets = -ENODEV;
 187                 goto out;
 188         }
 189
 190         if (length == 0) {
 191                 rets = 0;
 192                 goto out;
 193         }
 194
 195         if (ubuf == NULL) {
 196                 rets = -EMSGSIZE;
 197                 goto out;
 198         }
 199
 200         cb = mei_cl_read_cb(cl, file);
 201         if (cb)
 202                 goto copy_buffer;
 203
 204         if (*offset > 0)
 205                 *offset = 0;
 206
 207         rets = mei_cl_read_start(cl, length, file);
 208         if (rets && rets != -EBUSY) {
 209                 cl_dbg(dev, cl, "mei start read failure status = %zd\n", rets);
 210                 goto out;
 211         }
 212
 213         if (nonblock) {
 214                 rets = -EAGAIN;
 215                 goto out;
 216         }
 217
 218         mutex_unlock(&dev->device_lock);
 219         if (wait_event_interruptible(cl->rx_wait,
 220                                      mei_cl_read_cb(cl, file) ||
 221                                      !mei_cl_is_connected(cl))) {
 222                 if (signal_pending(current))
 223                         return -EINTR;
 224                 return -ERESTARTSYS;
 225         }
 226         mutex_lock(&dev->device_lock);
 227
 228         if (!mei_cl_is_connected(cl)) {
 229                 rets = -ENODEV;
 230                 goto out;
 231         }
 232
 233         cb = mei_cl_read_cb(cl, file);
 234         if (!cb) {
 235                 rets = 0;
 236                 goto out;
 237         }
 238
 239 copy_buffer:
 240         /* now copy the data to user space */
 241         if (cb->status) {
 242                 rets = cb->status;
 243                 cl_dbg(dev, cl, "read operation failed %zd\n", rets);
 244                 goto free;
 245         }
 246
 247         cl_dbg(dev, cl, "buf.size = %zu buf.idx = %zu offset = %lld\n",
 248                cb->buf.size, cb->buf_idx, *offset);
 249         if (*offset >= cb->buf_idx) {
 250                 rets = 0;
 251                 goto free;
 252         }
 253
 254         /* length is being truncated to PAGE_SIZE,
 255          * however buf_idx may point beyond that */
 256         length = min_t(size_t, length, cb->buf_idx - *offset);
 257
 258         if (copy_to_user(ubuf, cb->buf.data + *offset, length)) {
 259                 dev_dbg(dev->dev, "failed to copy data to userland\n");
 260                 rets = -EFAULT;
 261                 goto free;
 262         }
 263
 264         rets = length;
 265         *offset += length;
 266         /* not all data was read, keep the cb */
 267         if (*offset < cb->buf_idx)
 268                 goto out;
 269
 270 free:
 271         mei_cl_del_rd_completed(cl, cb);
 272         *offset = 0;
 273
 274 out:
 275         cl_dbg(dev, cl, "end mei read rets = %zd\n", rets);
 276         mutex_unlock(&dev->device_lock);
 277         return rets;
 278 }
 279
 280 /**
 281  * mei_cl_vtag_by_fp - obtain the vtag by file pointer
 282  *
 283  * @cl: host client
 284  * @fp: pointer to file structure
 285  *
 286  * Return: vtag value on success, otherwise 0
 287  */
 288 static u8 mei_cl_vtag_by_fp(const struct mei_cl *cl, const struct file *fp)
 289 {
 290         struct mei_cl_vtag *cl_vtag;
 291
 292         if (!fp)
 293                 return 0;
 294
 295         list_for_each_entry(cl_vtag, &cl->vtag_map, list)
 296                 if (cl_vtag->fp == fp)
 297                         return cl_vtag->vtag;
 298         return 0;
 299 }
 300
 301 /**
 302  * mei_write - the write function.
 303  *
 304  * @file: pointer to file structure
 305  * @ubuf: pointer to user buffer
 306  * @length: buffer length
 307  * @offset: data offset in buffer
 308  *
 309  * Return: >=0 data length on success , <0 on error
 310  */
 311 static ssize_t mei_write(struct file *file, const char __user *ubuf,
 312                          size_t length, loff_t *offset)
 313 {
 314         struct mei_cl *cl = file->private_data;
 315         struct mei_cl_cb *cb;
 316         struct mei_device *dev;
 317         ssize_t rets;
 318
 319         if (WARN_ON(!cl || !cl->dev))
 320                 return -ENODEV;
 321
 322         dev = cl->dev;
 323
 324         mutex_lock(&dev->device_lock);
 325
 326         if (dev->dev_state != MEI_DEV_ENABLED) {
 327                 rets = -ENODEV;
 328                 goto out;
 329         }
 330
 331         if (!mei_cl_is_connected(cl)) {
 332                 cl_err(dev, cl, "is not connected");
 333                 rets = -ENODEV;
 334                 goto out;
 335         }
 336
 337         if (!mei_me_cl_is_active(cl->me_cl)) {
 338                 rets = -ENOTTY;
 339                 goto out;
 340         }
 341
 342         if (length > mei_cl_mtu(cl)) {
 343                 rets = -EFBIG;
 344                 goto out;
 345         }
 346
 347         if (length == 0) {
 348                 rets = 0;
 349                 goto out;
 350         }
 351
 352         while (cl->tx_cb_queued >= dev->tx_queue_limit) {
 353                 if (file->f_flags & O_NONBLOCK) {
 354                         rets = -EAGAIN;
 355                         goto out;
 356                 }
 357                 mutex_unlock(&dev->device_lock);
 358                 rets = wait_event_interruptible(cl->tx_wait,
 359                                 cl->writing_state == MEI_WRITE_COMPLETE ||
 360                                 (!mei_cl_is_connected(cl)));
 361                 mutex_lock(&dev->device_lock);
 362                 if (rets) {
 363                         if (signal_pending(current))
 364                                 rets = -EINTR;
 365                         goto out;
 366                 }
 367                 if (!mei_cl_is_connected(cl)) {
 368                         rets = -ENODEV;
 369                         goto out;
 370                 }
 371         }
 372
 373         cb = mei_cl_alloc_cb(cl, length, MEI_FOP_WRITE, file);
 374         if (!cb) {
 375                 rets = -ENOMEM;
 376                 goto out;
 377         }
 378         cb->vtag = mei_cl_vtag_by_fp(cl, file);
 379
 380         rets = copy_from_user(cb->buf.data, ubuf, length);
 381         if (rets) {
 382                 dev_dbg(dev->dev, "failed to copy data from userland\n");
 383                 rets = -EFAULT;
 384                 mei_io_cb_free(cb);
 385                 goto out;
 386         }
 387
 388         rets = mei_cl_write(cl, cb);
 389 out:
 390         mutex_unlock(&dev->device_lock);
 391         return rets;
 392 }
 393
 394 /**
 395  * mei_ioctl_connect_client - the connect to fw client IOCTL function
 396  *
 397  * @file: private data of the file object
 398  * @in_client_uuid: requested UUID for connection
 399  * @client: IOCTL connect data, output parameters
 400  *
 401  * Locking: called under "dev->device_lock" lock
 402  *
 403  * Return: 0 on success, <0 on failure.
 404  */
 405 static int mei_ioctl_connect_client(struct file *file,
 406                                     const uuid_le *in_client_uuid,
 407                                     struct mei_client *client)
 408 {
 409         struct mei_device *dev;
 410         struct mei_me_client *me_cl;
 411         struct mei_cl *cl;
 412         int rets;
 413
 414         cl = file->private_data;
 415         dev = cl->dev;
 416
 417         if (cl->state != MEI_FILE_INITIALIZING &&
 418             cl->state != MEI_FILE_DISCONNECTED)
 419                 return  -EBUSY;
 420
 421         /* find ME client we're trying to connect to */
 422         me_cl = mei_me_cl_by_uuid(dev, in_client_uuid);
 423         if (!me_cl) {
 424                 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
 425                         in_client_uuid);
 426                 rets = -ENOTTY;
 427                 goto end;
 428         }
 429
 430         if (me_cl->props.fixed_address) {
 431                 bool forbidden = dev->override_fixed_address ?
 432                          !dev->allow_fixed_address : !dev->hbm_f_fa_supported;
 433                 if (forbidden) {
 434                         dev_dbg(dev->dev, "Connection forbidden to FW Client UUID = %pUl\n",
 435                                 in_client_uuid);
 436                         rets = -ENOTTY;
 437                         goto end;
 438                 }
 439         }
 440
 441         dev_dbg(dev->dev, "Connect to FW Client ID = %d\n",
 442                         me_cl->client_id);
 443         dev_dbg(dev->dev, "FW Client - Protocol Version = %d\n",
 444                         me_cl->props.protocol_version);
 445         dev_dbg(dev->dev, "FW Client - Max Msg Len = %d\n",
 446                         me_cl->props.max_msg_length);
 447
 448         /* prepare the output buffer */
 449         client->max_msg_length = me_cl->props.max_msg_length;
 450         client->protocol_version = me_cl->props.protocol_version;
 451         dev_dbg(dev->dev, "Can connect?\n");
 452
 453         rets = mei_cl_connect(cl, me_cl, file);
 454
 455 end:
 456         mei_me_cl_put(me_cl);
 457         return rets;
 458 }
 459
 460 /**
 461  * mei_vt_support_check - check if client support vtags
 462  *
 463  * Locking: called under "dev->device_lock" lock
 464  *
 465  * @dev: mei_device
 466  * @uuid: client UUID
 467  *
 468  * Return:
 469  *      0 - supported
 470  *      -ENOTTY - no such client
 471  *      -EOPNOTSUPP - vtags are not supported by client
 472  */
 473 static int mei_vt_support_check(struct mei_device *dev, const uuid_le *uuid)
 474 {
 475         struct mei_me_client *me_cl;
 476         int ret;
 477
 478         if (!dev->hbm_f_vt_supported)
 479                 return -EOPNOTSUPP;
 480
 481         me_cl = mei_me_cl_by_uuid(dev, uuid);
 482         if (!me_cl) {
 483                 dev_dbg(dev->dev, "Cannot connect to FW Client UUID = %pUl\n",
 484                         uuid);
 485                 return -ENOTTY;
 486         }
 487         ret = me_cl->props.vt_supported ? 0 : -EOPNOTSUPP;
 488         mei_me_cl_put(me_cl);
 489
 490         return ret;
 491 }
 492
 493 /**
 494  * mei_ioctl_connect_vtag - connect to fw client with vtag IOCTL function
 495  *
 496  * @file: private data of the file object
 497  * @in_client_uuid: requested UUID for connection
 498  * @client: IOCTL connect data, output parameters
 499  * @vtag: vm tag
 500  *
 501  * Locking: called under "dev->device_lock" lock
 502  *
 503  * Return: 0 on success, <0 on failure.
 504  */
 505 static int mei_ioctl_connect_vtag(struct file *file,
 506                                   const uuid_le *in_client_uuid,
 507                                   struct mei_client *client,
 508                                   u8 vtag)
 509 {
 510         struct mei_device *dev;
 511         struct mei_cl *cl;
 512         struct mei_cl *pos;
 513         struct mei_cl_vtag *cl_vtag;
 514
 515         cl = file->private_data;
 516         dev = cl->dev;
 517
 518         dev_dbg(dev->dev, "FW Client %pUl vtag %d\n", in_client_uuid, vtag);
 519
 520         switch (cl->state) {
 521         case MEI_FILE_DISCONNECTED:
 522                 if (mei_cl_vtag_by_fp(cl, file) != vtag) {
 523                         dev_err(dev->dev, "reconnect with different vtag\n");
 524                         return -EINVAL;
 525                 }
 526                 break;
 527         case MEI_FILE_INITIALIZING:
 528                 /* malicious connect from another thread may push vtag */
 529                 if (!IS_ERR(mei_cl_fp_by_vtag(cl, vtag))) {
 530                         dev_err(dev->dev, "vtag already filled\n");
 531                         return -EINVAL;
 532                 }
 533
 534                 list_for_each_entry(pos, &dev->file_list, link) {
 535                         if (pos == cl)
 536                                 continue;
 537                         if (!pos->me_cl)
 538                                 continue;
 539
 540                         /* only search for same UUID */
 541                         if (uuid_le_cmp(*mei_cl_uuid(pos), *in_client_uuid))
 542                                 continue;
 543
 544                         /* if tag already exist try another fp */
 545                         if (!IS_ERR(mei_cl_fp_by_vtag(pos, vtag)))
 546                                 continue;
 547
 548                         /* replace cl with acquired one */
 549                         dev_dbg(dev->dev, "replacing with existing cl\n");
 550                         mei_cl_unlink(cl);
 551                         kfree(cl);
 552                         file->private_data = pos;
 553                         cl = pos;
 554                         break;
 555                 }
 556
 557                 cl_vtag = mei_cl_vtag_alloc(file, vtag);
 558                 if (IS_ERR(cl_vtag))
 559                         return -ENOMEM;
 560
 561                 list_add_tail(&cl_vtag->list, &cl->vtag_map);
 562                 break;
 563         default:
 564                 return -EBUSY;
 565         }
 566
 567         while (cl->state != MEI_FILE_INITIALIZING &&
 568                cl->state != MEI_FILE_DISCONNECTED &&
 569                cl->state != MEI_FILE_CONNECTED) {
 570                 mutex_unlock(&dev->device_lock);
 571                 wait_event_timeout(cl->wait,
 572                                    (cl->state == MEI_FILE_CONNECTED ||
 573                                     cl->state == MEI_FILE_DISCONNECTED ||
 574                                     cl->state == MEI_FILE_DISCONNECT_REQUIRED ||
 575                                     cl->state == MEI_FILE_DISCONNECT_REPLY),
 576                                    mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 577                 mutex_lock(&dev->device_lock);
 578         }
 579
 580         if (!mei_cl_is_connected(cl))
 581                 return mei_ioctl_connect_client(file, in_client_uuid, client);
 582
 583         client->max_msg_length = cl->me_cl->props.max_msg_length;
 584         client->protocol_version = cl->me_cl->props.protocol_version;
 585
 586         return 0;
 587 }
 588
 589 /**
 590  * mei_ioctl_client_notify_request -
 591  *     propagate event notification request to client
 592  *
 593  * @file: pointer to file structure
 594  * @request: 0 - disable, 1 - enable
 595  *
 596  * Return: 0 on success , <0 on error
 597  */
 598 static int mei_ioctl_client_notify_request(const struct file *file, u32 request)
 599 {
 600         struct mei_cl *cl = file->private_data;
 601
 602         if (request != MEI_HBM_NOTIFICATION_START &&
 603             request != MEI_HBM_NOTIFICATION_STOP)
 604                 return -EINVAL;
 605
 606         return mei_cl_notify_request(cl, file, (u8)request);
 607 }
 608
 609 /**
 610  * mei_ioctl_client_notify_get -  wait for notification request
 611  *
 612  * @file: pointer to file structure
 613  * @notify_get: 0 - disable, 1 - enable
 614  *
 615  * Return: 0 on success , <0 on error
 616  */
 617 static int mei_ioctl_client_notify_get(const struct file *file, u32 *notify_get)
 618 {
 619         struct mei_cl *cl = file->private_data;
 620         bool notify_ev;
 621         bool block = (file->f_flags & O_NONBLOCK) == 0;
 622         int rets;
 623
 624         rets = mei_cl_notify_get(cl, block, &notify_ev);
 625         if (rets)
 626                 return rets;
 627
 628         *notify_get = notify_ev ? 1 : 0;
 629         return 0;
 630 }
 631
 632 /**
 633  * mei_ioctl - the IOCTL function
 634  *
 635  * @file: pointer to file structure
 636  * @cmd: ioctl command
 637  * @data: pointer to mei message structure
 638  *
 639  * Return: 0 on success , <0 on error
 640  */
 641 static long mei_ioctl(struct file *file, unsigned int cmd, unsigned long data)
 642 {
 643         struct mei_device *dev;
 644         struct mei_cl *cl = file->private_data;
 645         struct mei_connect_client_data conn;
 646         struct mei_connect_client_data_vtag conn_vtag;
 647         const uuid_le *cl_uuid;
 648         struct mei_client *props;
 649         u8 vtag;
 650         u32 notify_get, notify_req;
 651         int rets;
 652
 653
 654         if (WARN_ON(!cl || !cl->dev))
 655                 return -ENODEV;
 656
 657         dev = cl->dev;
 658
 659         dev_dbg(dev->dev, "IOCTL cmd = 0x%x", cmd);
 660
 661         mutex_lock(&dev->device_lock);
 662         if (dev->dev_state != MEI_DEV_ENABLED) {
 663                 rets = -ENODEV;
 664                 goto out;
 665         }
 666
 667         switch (cmd) {
 668         case IOCTL_MEI_CONNECT_CLIENT:
 669                 dev_dbg(dev->dev, ": IOCTL_MEI_CONNECT_CLIENT.\n");
 670                 if (copy_from_user(&conn, (char __user *)data, sizeof(conn))) {
 671                         dev_dbg(dev->dev, "failed to copy data from userland\n");
 672                         rets = -EFAULT;
 673                         goto out;
 674                 }
 675                 cl_uuid = &conn.in_client_uuid;
 676                 props = &conn.out_client_properties;
 677                 vtag = 0;
 678
 679                 rets = mei_vt_support_check(dev, cl_uuid);
 680                 if (rets == -ENOTTY)
 681                         goto out;
 682                 if (!rets)
 683                         rets = mei_ioctl_connect_vtag(file, cl_uuid, props,
 684                                                       vtag);
 685                 else
 686                         rets = mei_ioctl_connect_client(file, cl_uuid, props);
 687                 if (rets)
 688                         goto out;
 689
 690                 /* if all is ok, copying the data back to user. */
 691                 if (copy_to_user((char __user *)data, &conn, sizeof(conn))) {
 692                         dev_dbg(dev->dev, "failed to copy data to userland\n");
 693                         rets = -EFAULT;
 694                         goto out;
 695                 }
 696
 697                 break;
 698
 699         case IOCTL_MEI_CONNECT_CLIENT_VTAG:
 700                 dev_dbg(dev->dev, "IOCTL_MEI_CONNECT_CLIENT_VTAG\n");
 701                 if (copy_from_user(&conn_vtag, (char __user *)data,
 702                                    sizeof(conn_vtag))) {
 703                         dev_dbg(dev->dev, "failed to copy data from userland\n");
 704                         rets = -EFAULT;
 705                         goto out;
 706                 }
 707
 708                 cl_uuid = &conn_vtag.connect.in_client_uuid;
 709                 props = &conn_vtag.out_client_properties;
 710                 vtag = conn_vtag.connect.vtag;
 711
 712                 rets = mei_vt_support_check(dev, cl_uuid);
 713                 if (rets == -EOPNOTSUPP)
 714                         dev_dbg(dev->dev, "FW Client %pUl does not support vtags\n",
 715                                 cl_uuid);
 716                 if (rets)
 717                         goto out;
 718
 719                 if (!vtag) {
 720                         dev_dbg(dev->dev, "vtag can't be zero\n");
 721                         rets = -EINVAL;
 722                         goto out;
 723                 }
 724
 725                 rets = mei_ioctl_connect_vtag(file, cl_uuid, props, vtag);
 726                 if (rets)
 727                         goto out;
 728
 729                 /* if all is ok, copying the data back to user. */
 730                 if (copy_to_user((char __user *)data, &conn_vtag,
 731                                  sizeof(conn_vtag))) {
 732                         dev_dbg(dev->dev, "failed to copy data to userland\n");
 733                         rets = -EFAULT;
 734                         goto out;
 735                 }
 736
 737                 break;
 738
 739         case IOCTL_MEI_NOTIFY_SET:
 740                 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_SET.\n");
 741                 if (copy_from_user(&notify_req,
 742                                    (char __user *)data, sizeof(notify_req))) {
 743                         dev_dbg(dev->dev, "failed to copy data from userland\n");
 744                         rets = -EFAULT;
 745                         goto out;
 746                 }
 747                 rets = mei_ioctl_client_notify_request(file, notify_req);
 748                 break;
 749
 750         case IOCTL_MEI_NOTIFY_GET:
 751                 dev_dbg(dev->dev, ": IOCTL_MEI_NOTIFY_GET.\n");
 752                 rets = mei_ioctl_client_notify_get(file, &notify_get);
 753                 if (rets)
 754                         goto out;
 755
 756                 dev_dbg(dev->dev, "copy connect data to user\n");
 757                 if (copy_to_user((char __user *)data,
 758                                 &notify_get, sizeof(notify_get))) {
 759                         dev_dbg(dev->dev, "failed to copy data to userland\n");
 760                         rets = -EFAULT;
 761                         goto out;
 762
 763                 }
 764                 break;
 765
 766         default:
 767                 rets = -ENOIOCTLCMD;
 768         }
 769
 770 out:
 771         mutex_unlock(&dev->device_lock);
 772         return rets;
 773 }
 774
 775 /**
 776  * mei_poll - the poll function
 777  *
 778  * @file: pointer to file structure
 779  * @wait: pointer to poll_table structure
 780  *
 781  * Return: poll mask
 782  */
 783 static __poll_t mei_poll(struct file *file, poll_table *wait)
 784 {
 785         __poll_t req_events = poll_requested_events(wait);
 786         struct mei_cl *cl = file->private_data;
 787         struct mei_device *dev;
 788         __poll_t mask = 0;
 789         bool notify_en;
 790
 791         if (WARN_ON(!cl || !cl->dev))
 792                 return EPOLLERR;
 793
 794         dev = cl->dev;
 795
 796         mutex_lock(&dev->device_lock);
 797
 798         notify_en = cl->notify_en && (req_events & EPOLLPRI);
 799
 800         if (dev->dev_state != MEI_DEV_ENABLED ||
 801             !mei_cl_is_connected(cl)) {
 802                 mask = EPOLLERR;
 803                 goto out;
 804         }
 805
 806         if (notify_en) {
 807                 poll_wait(file, &cl->ev_wait, wait);
 808                 if (cl->notify_ev)
 809                         mask |= EPOLLPRI;
 810         }
 811
 812         if (req_events & (EPOLLIN | EPOLLRDNORM)) {
 813                 poll_wait(file, &cl->rx_wait, wait);
 814
 815                 if (mei_cl_read_cb(cl, file))
 816                         mask |= EPOLLIN | EPOLLRDNORM;
 817                 else
 818                         mei_cl_read_start(cl, mei_cl_mtu(cl), file);
 819         }
 820
 821         if (req_events & (EPOLLOUT | EPOLLWRNORM)) {
 822                 poll_wait(file, &cl->tx_wait, wait);
 823                 if (cl->tx_cb_queued < dev->tx_queue_limit)
 824                         mask |= EPOLLOUT | EPOLLWRNORM;
 825         }
 826
 827 out:
 828         mutex_unlock(&dev->device_lock);
 829         return mask;
 830 }
 831
 832 /**
 833  * mei_cl_is_write_queued - check if the client has pending writes.
 834  *
 835  * @cl: writing host client
 836  *
 837  * Return: true if client is writing, false otherwise.
 838  */
 839 static bool mei_cl_is_write_queued(struct mei_cl *cl)
 840 {
 841         struct mei_device *dev = cl->dev;
 842         struct mei_cl_cb *cb;
 843
 844         list_for_each_entry(cb, &dev->write_list, list)
 845                 if (cb->cl == cl)
 846                         return true;
 847         list_for_each_entry(cb, &dev->write_waiting_list, list)
 848                 if (cb->cl == cl)
 849                         return true;
 850         return false;
 851 }
 852
 853 /**
 854  * mei_fsync - the fsync handler
 855  *
 856  * @fp:       pointer to file structure
 857  * @start:    unused
 858  * @end:      unused
 859  * @datasync: unused
 860  *
 861  * Return: 0 on success, -ENODEV if client is not connected
 862  */
 863 static int mei_fsync(struct file *fp, loff_t start, loff_t end, int datasync)
 864 {
 865         struct mei_cl *cl = fp->private_data;
 866         struct mei_device *dev;
 867         int rets;
 868
 869         if (WARN_ON(!cl || !cl->dev))
 870                 return -ENODEV;
 871
 872         dev = cl->dev;
 873
 874         mutex_lock(&dev->device_lock);
 875
 876         if (dev->dev_state != MEI_DEV_ENABLED || !mei_cl_is_connected(cl)) {
 877                 rets = -ENODEV;
 878                 goto out;
 879         }
 880
 881         while (mei_cl_is_write_queued(cl)) {
 882                 mutex_unlock(&dev->device_lock);
 883                 rets = wait_event_interruptible(cl->tx_wait,
 884                                 cl->writing_state == MEI_WRITE_COMPLETE ||
 885                                 !mei_cl_is_connected(cl));
 886                 mutex_lock(&dev->device_lock);
 887                 if (rets) {
 888                         if (signal_pending(current))
 889                                 rets = -EINTR;
 890                         goto out;
 891                 }
 892                 if (!mei_cl_is_connected(cl)) {
 893                         rets = -ENODEV;
 894                         goto out;
 895                 }
 896         }
 897         rets = 0;
 898 out:
 899         mutex_unlock(&dev->device_lock);
 900         return rets;
 901 }
 902
 903 /**
 904  * mei_fasync - asynchronous io support
 905  *
 906  * @fd: file descriptor
 907  * @file: pointer to file structure
 908  * @band: band bitmap
 909  *
 910  * Return: negative on error,
 911  *         0 if it did no changes,
 912  *         and positive a process was added or deleted
 913  */
 914 static int mei_fasync(int fd, struct file *file, int band)
 915 {
 916
 917         struct mei_cl *cl = file->private_data;
 918
 919         if (!mei_cl_is_connected(cl))
 920                 return -ENODEV;
 921
 922         return fasync_helper(fd, file, band, &cl->ev_async);
 923 }
 924
 925 /**
 926  * trc_show - mei device trc attribute show method
 927  *
 928  * @device: device pointer
 929  * @attr: attribute pointer
 930  * @buf:  char out buffer
 931  *
 932  * Return: number of the bytes printed into buf or error
 933  */
 934 static ssize_t trc_show(struct device *device,
 935                         struct device_attribute *attr, char *buf)
 936 {
 937         struct mei_device *dev = dev_get_drvdata(device);
 938         u32 trc;
 939         int ret;
 940
 941         ret = mei_trc_status(dev, &trc);
 942         if (ret)
 943                 return ret;
 944         return sprintf(buf, "%08X\n", trc);
 945 }
 946 static DEVICE_ATTR_RO(trc);
 947
 948 /**
 949  * fw_status_show - mei device fw_status attribute show method
 950  *
 951  * @device: device pointer
 952  * @attr: attribute pointer
 953  * @buf:  char out buffer
 954  *
 955  * Return: number of the bytes printed into buf or error
 956  */
 957 static ssize_t fw_status_show(struct device *device,
 958                 struct device_attribute *attr, char *buf)
 959 {
 960         struct mei_device *dev = dev_get_drvdata(device);
 961         struct mei_fw_status fw_status;
 962         int err, i;
 963         ssize_t cnt = 0;
 964
 965         mutex_lock(&dev->device_lock);
 966         err = mei_fw_status(dev, &fw_status);
 967         mutex_unlock(&dev->device_lock);
 968         if (err) {
 969                 dev_err(device, "read fw_status error = %d\n", err);
 970                 return err;
 971         }
 972
 973         for (i = 0; i < fw_status.count; i++)
 974                 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%08X\n",
 975                                 fw_status.status[i]);
 976         return cnt;
 977 }
 978 static DEVICE_ATTR_RO(fw_status);
 979
 980 /**
 981  * hbm_ver_show - display HBM protocol version negotiated with FW
 982  *
 983  * @device: device pointer
 984  * @attr: attribute pointer
 985  * @buf:  char out buffer
 986  *
 987  * Return: number of the bytes printed into buf or error
 988  */
 989 static ssize_t hbm_ver_show(struct device *device,
 990                             struct device_attribute *attr, char *buf)
 991 {
 992         struct mei_device *dev = dev_get_drvdata(device);
 993         struct hbm_version ver;
 994
 995         mutex_lock(&dev->device_lock);
 996         ver = dev->version;
 997         mutex_unlock(&dev->device_lock);
 998
 999         return sprintf(buf, "%u.%u\n", ver.major_version, ver.minor_version);
1000 }
1001 static DEVICE_ATTR_RO(hbm_ver);
1002
1003 /**
1004  * hbm_ver_drv_show - display HBM protocol version advertised by driver
1005  *
1006  * @device: device pointer
1007  * @attr: attribute pointer
1008  * @buf:  char out buffer
1009  *
1010  * Return: number of the bytes printed into buf or error
1011  */
1012 static ssize_t hbm_ver_drv_show(struct device *device,
1013                                 struct device_attribute *attr, char *buf)
1014 {
1015         return sprintf(buf, "%u.%u\n", HBM_MAJOR_VERSION, HBM_MINOR_VERSION);
1016 }
1017 static DEVICE_ATTR_RO(hbm_ver_drv);
1018
1019 static ssize_t tx_queue_limit_show(struct device *device,
1020                                    struct device_attribute *attr, char *buf)
1021 {
1022         struct mei_device *dev = dev_get_drvdata(device);
1023         u8 size = 0;
1024
1025         mutex_lock(&dev->device_lock);
1026         size = dev->tx_queue_limit;
1027         mutex_unlock(&dev->device_lock);
1028
1029         return snprintf(buf, PAGE_SIZE, "%u\n", size);
1030 }
1031
1032 static ssize_t tx_queue_limit_store(struct device *device,
1033                                     struct device_attribute *attr,
1034                                     const char *buf, size_t count)
1035 {
1036         struct mei_device *dev = dev_get_drvdata(device);
1037         u8 limit;
1038         unsigned int inp;
1039         int err;
1040
1041         err = kstrtouint(buf, 10, &inp);
1042         if (err)
1043                 return err;
1044         if (inp > MEI_TX_QUEUE_LIMIT_MAX || inp < MEI_TX_QUEUE_LIMIT_MIN)
1045                 return -EINVAL;
1046         limit = inp;
1047
1048         mutex_lock(&dev->device_lock);
1049         dev->tx_queue_limit = limit;
1050         mutex_unlock(&dev->device_lock);
1051
1052         return count;
1053 }
1054 static DEVICE_ATTR_RW(tx_queue_limit);
1055
1056 /**
1057  * fw_ver_show - display ME FW version
1058  *
1059  * @device: device pointer
1060  * @attr: attribute pointer
1061  * @buf:  char out buffer
1062  *
1063  * Return: number of the bytes printed into buf or error
1064  */
1065 static ssize_t fw_ver_show(struct device *device,
1066                            struct device_attribute *attr, char *buf)
1067 {
1068         struct mei_device *dev = dev_get_drvdata(device);
1069         struct mei_fw_version *ver;
1070         ssize_t cnt = 0;
1071         int i;
1072
1073         ver = dev->fw_ver;
1074
1075         for (i = 0; i < MEI_MAX_FW_VER_BLOCKS; i++)
1076                 cnt += scnprintf(buf + cnt, PAGE_SIZE - cnt, "%u:%u.%u.%u.%u\n",
1077                                  ver[i].platform, ver[i].major, ver[i].minor,
1078                                  ver[i].hotfix, ver[i].buildno);
1079         return cnt;
1080 }
1081 static DEVICE_ATTR_RO(fw_ver);
1082
1083 /**
1084  * dev_state_show - display device state
1085  *
1086  * @device: device pointer
1087  * @attr: attribute pointer
1088  * @buf:  char out buffer
1089  *
1090  * Return: number of the bytes printed into buf or error
1091  */
1092 static ssize_t dev_state_show(struct device *device,
1093                               struct device_attribute *attr, char *buf)
1094 {
1095         struct mei_device *dev = dev_get_drvdata(device);
1096         enum mei_dev_state dev_state;
1097
1098         mutex_lock(&dev->device_lock);
1099         dev_state = dev->dev_state;
1100         mutex_unlock(&dev->device_lock);
1101
1102         return sprintf(buf, "%s", mei_dev_state_str(dev_state));
1103 }
1104 static DEVICE_ATTR_RO(dev_state);
1105
1106 /**
1107  * dev_set_devstate: set to new device state and notify sysfs file.
1108  *
1109  * @dev: mei_device
1110  * @state: new device state
1111  */
1112 void mei_set_devstate(struct mei_device *dev, enum mei_dev_state state)
1113 {
1114         struct device *clsdev;
1115
1116         if (dev->dev_state == state)
1117                 return;
1118
1119         dev->dev_state = state;
1120
1121         clsdev = class_find_device_by_devt(mei_class, dev->cdev.dev);
1122         if (clsdev) {
1123                 sysfs_notify(&clsdev->kobj, NULL, "dev_state");
1124                 put_device(clsdev);
1125         }
1126 }
1127
1128 /**
1129  * kind_show - display device kind
1130  *
1131  * @device: device pointer
1132  * @attr: attribute pointer
1133  * @buf: char out buffer
1134  *
1135  * Return: number of the bytes printed into buf or error
1136  */
1137 static ssize_t kind_show(struct device *device,
1138                          struct device_attribute *attr, char *buf)
1139 {
1140         struct mei_device *dev = dev_get_drvdata(device);
1141         ssize_t ret;
1142
1143         if (dev->kind)
1144                 ret = sprintf(buf, "%s\n", dev->kind);
1145         else
1146                 ret = sprintf(buf, "%s\n", "mei");
1147
1148         return ret;
1149 }
1150 static DEVICE_ATTR_RO(kind);
1151
1152 static struct attribute *mei_attrs[] = {
1153         &dev_attr_fw_status.attr,
1154         &dev_attr_hbm_ver.attr,
1155         &dev_attr_hbm_ver_drv.attr,
1156         &dev_attr_tx_queue_limit.attr,
1157         &dev_attr_fw_ver.attr,
1158         &dev_attr_dev_state.attr,
1159         &dev_attr_trc.attr,
1160         &dev_attr_kind.attr,
1161         NULL
1162 };
1163 ATTRIBUTE_GROUPS(mei);
1164
1165 /*
1166  * file operations structure will be used for mei char device.
1167  */
1168 static const struct file_operations mei_fops = {
1169         .owner = THIS_MODULE,
1170         .read = mei_read,
1171         .unlocked_ioctl = mei_ioctl,
1172         .compat_ioctl = compat_ptr_ioctl,
1173         .open = mei_open,
1174         .release = mei_release,
1175         .write = mei_write,
1176         .poll = mei_poll,
1177         .fsync = mei_fsync,
1178         .fasync = mei_fasync,
1179         .llseek = no_llseek
1180 };
1181
1182 /**
1183  * mei_minor_get - obtain next free device minor number
1184  *
1185  * @dev:  device pointer
1186  *
1187  * Return: allocated minor, or -ENOSPC if no free minor left
1188  */
1189 static int mei_minor_get(struct mei_device *dev)
1190 {
1191         int ret;
1192
1193         mutex_lock(&mei_minor_lock);
1194         ret = idr_alloc(&mei_idr, dev, 0, MEI_MAX_DEVS, GFP_KERNEL);
1195         if (ret >= 0)
1196                 dev->minor = ret;
1197         else if (ret == -ENOSPC)
1198                 dev_err(dev->dev, "too many mei devices\n");
1199
1200         mutex_unlock(&mei_minor_lock);
1201         return ret;
1202 }
1203
1204 /**
1205  * mei_minor_free - mark device minor number as free
1206  *
1207  * @dev:  device pointer
1208  */
1209 static void mei_minor_free(struct mei_device *dev)
1210 {
1211         mutex_lock(&mei_minor_lock);
1212         idr_remove(&mei_idr, dev->minor);
1213         mutex_unlock(&mei_minor_lock);
1214 }
1215
1216 int mei_register(struct mei_device *dev, struct device *parent)
1217 {
1218         struct device *clsdev; /* class device */
1219         int ret, devno;
1220
1221         ret = mei_minor_get(dev);
1222         if (ret < 0)
1223                 return ret;
1224
1225         /* Fill in the data structures */
1226         devno = MKDEV(MAJOR(mei_devt), dev->minor);
1227         cdev_init(&dev->cdev, &mei_fops);
1228         dev->cdev.owner = parent->driver->owner;
1229
1230         /* Add the device */
1231         ret = cdev_add(&dev->cdev, devno, 1);
1232         if (ret) {
1233                 dev_err(parent, "unable to add device %d:%d\n",
1234                         MAJOR(mei_devt), dev->minor);
1235                 goto err_dev_add;
1236         }
1237
1238         clsdev = device_create_with_groups(mei_class, parent, devno,
1239                                            dev, mei_groups,
1240                                            "mei%d", dev->minor);
1241
1242         if (IS_ERR(clsdev)) {
1243                 dev_err(parent, "unable to create device %d:%d\n",
1244                         MAJOR(mei_devt), dev->minor);
1245                 ret = PTR_ERR(clsdev);
1246                 goto err_dev_create;
1247         }
1248
1249         mei_dbgfs_register(dev, dev_name(clsdev));
1250
1251         return 0;
1252
1253 err_dev_create:
1254         cdev_del(&dev->cdev);
1255 err_dev_add:
1256         mei_minor_free(dev);
1257         return ret;
1258 }
1259 EXPORT_SYMBOL_GPL(mei_register);
1260
1261 void mei_deregister(struct mei_device *dev)
1262 {
1263         int devno;
1264
1265         devno = dev->cdev.dev;
1266         cdev_del(&dev->cdev);
1267
1268         mei_dbgfs_deregister(dev);
1269
1270         device_destroy(mei_class, devno);
1271
1272         mei_minor_free(dev);
1273 }
1274 EXPORT_SYMBOL_GPL(mei_deregister);
1275
1276 static int __init mei_init(void)
1277 {
1278         int ret;
1279
1280         mei_class = class_create(THIS_MODULE, "mei");
1281         if (IS_ERR(mei_class)) {
1282                 pr_err("couldn't create class\n");
1283                 ret = PTR_ERR(mei_class);
1284                 goto err;
1285         }
1286
1287         ret = alloc_chrdev_region(&mei_devt, 0, MEI_MAX_DEVS, "mei");
1288         if (ret < 0) {
1289                 pr_err("unable to allocate char dev region\n");
1290                 goto err_class;
1291         }
1292
1293         ret = mei_cl_bus_init();
1294         if (ret < 0) {
1295                 pr_err("unable to initialize bus\n");
1296                 goto err_chrdev;
1297         }
1298
1299         return 0;
1300
1301 err_chrdev:
1302         unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
1303 err_class:
1304         class_destroy(mei_class);
1305 err:
1306         return ret;
1307 }
1308
1309 static void __exit mei_exit(void)
1310 {
1311         unregister_chrdev_region(mei_devt, MEI_MAX_DEVS);
1312         class_destroy(mei_class);
1313         mei_cl_bus_exit();
1314 }
1315
1316 module_init(mei_init);
1317 module_exit(mei_exit);
1318
1319 MODULE_AUTHOR("Intel Corporation");
1320 MODULE_DESCRIPTION("Intel(R) Management Engine Interface");
1321 MODULE_LICENSE("GPL v2");
1322