drivers/misc/mei/amthif.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 #include <linux/kernel.h>
  18 #include <linux/fs.h>
  19 #include <linux/errno.h>
  20 #include <linux/types.h>
  21 #include <linux/fcntl.h>
  22 #include <linux/aio.h>
  23 #include <linux/ioctl.h>
  24 #include <linux/cdev.h>
  25 #include <linux/list.h>
  26 #include <linux/delay.h>
  27 #include <linux/sched.h>
  28 #include <linux/uuid.h>
  29 #include <linux/jiffies.h>
  30 #include <linux/uaccess.h>
  31 #include <linux/slab.h>
  32
  33 #include <linux/mei.h>
  34
  35 #include "mei_dev.h"
  36 #include "hbm.h"
  37 #include "client.h"
  38
  39 const uuid_le mei_amthif_guid  = UUID_LE(0x12f80028, 0xb4b7, 0x4b2d,
  40                                          0xac, 0xa8, 0x46, 0xe0,
  41                                          0xff, 0x65, 0x81, 0x4c);
  42
  43 /**
  44  * mei_amthif_reset_params - initializes mei device iamthif
  45  *
  46  * @dev: the device structure
  47  */
  48 void mei_amthif_reset_params(struct mei_device *dev)
  49 {
  50         /* reset iamthif parameters. */
  51         dev->iamthif_current_cb = NULL;
  52         dev->iamthif_msg_buf_size = 0;
  53         dev->iamthif_msg_buf_index = 0;
  54         dev->iamthif_canceled = false;
  55         dev->iamthif_ioctl = false;
  56         dev->iamthif_state = MEI_IAMTHIF_IDLE;
  57         dev->iamthif_timer = 0;
  58         dev->iamthif_stall_timer = 0;
  59         dev->iamthif_open_count = 0;
  60 }
  61
  62 /**
  63  * mei_amthif_host_init - mei initialization amthif client.
  64  *
  65  * @dev: the device structure
  66  *
  67  */
  68 int mei_amthif_host_init(struct mei_device *dev)
  69 {
  70         struct mei_cl *cl = &dev->iamthif_cl;
  71         struct mei_me_client *me_cl;
  72         unsigned char *msg_buf;
  73         int ret;
  74
  75         dev->iamthif_state = MEI_IAMTHIF_IDLE;
  76
  77         mei_cl_init(cl, dev);
  78
  79         me_cl = mei_me_cl_by_uuid(dev, &mei_amthif_guid);
  80         if (!me_cl) {
  81                 dev_info(dev->dev, "amthif: failed to find the client");
  82                 return -ENOTTY;
  83         }
  84
  85         cl->me_client_id = me_cl->client_id;
  86         cl->cl_uuid = me_cl->props.protocol_name;
  87
  88         /* Assign iamthif_mtu to the value received from ME  */
  89
  90         dev->iamthif_mtu = me_cl->props.max_msg_length;
  91         dev_dbg(dev->dev, "IAMTHIF_MTU = %d\n", dev->iamthif_mtu);
  92
  93         kfree(dev->iamthif_msg_buf);
  94         dev->iamthif_msg_buf = NULL;
  95
  96         /* allocate storage for ME message buffer */
  97         msg_buf = kcalloc(dev->iamthif_mtu,
  98                         sizeof(unsigned char), GFP_KERNEL);
  99         if (!msg_buf)
 100                 return -ENOMEM;
 101
 102         dev->iamthif_msg_buf = msg_buf;
 103
 104         ret = mei_cl_link(cl, MEI_IAMTHIF_HOST_CLIENT_ID);
 105
 106         if (ret < 0) {
 107                 dev_err(dev->dev,
 108                         "amthif: failed link client %d\n", ret);
 109                 return ret;
 110         }
 111
 112         ret = mei_cl_connect(cl, NULL);
 113
 114         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 115
 116         return ret;
 117 }
 118
 119 /**
 120  * mei_amthif_find_read_list_entry - finds a amthilist entry for current file
 121  *
 122  * @dev: the device structure
 123  * @file: pointer to file object
 124  *
 125  * returns   returned a list entry on success, NULL on failure.
 126  */
 127 struct mei_cl_cb *mei_amthif_find_read_list_entry(struct mei_device *dev,
 128                                                 struct file *file)
 129 {
 130         struct mei_cl_cb *cb;
 131
 132         list_for_each_entry(cb, &dev->amthif_rd_complete_list.list, list)
 133                 if (cb->file_object == file)
 134                         return cb;
 135         return NULL;
 136 }
 137
 138
 139 /**
 140  * mei_amthif_read - read data from AMTHIF client
 141  *
 142  * @dev: the device structure
 143  * @if_num:  minor number
 144  * @file: pointer to file object
 145  * @*ubuf: pointer to user data in user space
 146  * @length: data length to read
 147  * @offset: data read offset
 148  *
 149  * Locking: called under "dev->device_lock" lock
 150  *
 151  * returns
 152  *  returned data length on success,
 153  *  zero if no data to read,
 154  *  negative on failure.
 155  */
 156 int mei_amthif_read(struct mei_device *dev, struct file *file,
 157                char __user *ubuf, size_t length, loff_t *offset)
 158 {
 159         struct mei_cl *cl = file->private_data;
 160         struct mei_cl_cb *cb;
 161         unsigned long timeout;
 162         int rets;
 163         int wait_ret;
 164
 165         /* Only possible if we are in timeout */
 166         if (!cl) {
 167                 dev_err(dev->dev, "bad file ext.\n");
 168                 return -ETIME;
 169         }
 170
 171         dev_dbg(dev->dev, "checking amthif data\n");
 172         cb = mei_amthif_find_read_list_entry(dev, file);
 173
 174         /* Check for if we can block or not*/
 175         if (cb == NULL && file->f_flags & O_NONBLOCK)
 176                 return -EAGAIN;
 177
 178
 179         dev_dbg(dev->dev, "waiting for amthif data\n");
 180         while (cb == NULL) {
 181                 /* unlock the Mutex */
 182                 mutex_unlock(&dev->device_lock);
 183
 184                 wait_ret = wait_event_interruptible(dev->iamthif_cl.wait,
 185                         (cb = mei_amthif_find_read_list_entry(dev, file)));
 186
 187                 /* Locking again the Mutex */
 188                 mutex_lock(&dev->device_lock);
 189
 190                 if (wait_ret)
 191                         return -ERESTARTSYS;
 192
 193                 dev_dbg(dev->dev, "woke up from sleep\n");
 194         }
 195
 196
 197         dev_dbg(dev->dev, "Got amthif data\n");
 198         dev->iamthif_timer = 0;
 199
 200         if (cb) {
 201                 timeout = cb->read_time +
 202                         mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
 203                 dev_dbg(dev->dev, "amthif timeout = %lud\n",
 204                                 timeout);
 205
 206                 if  (time_after(jiffies, timeout)) {
 207                         dev_dbg(dev->dev, "amthif Time out\n");
 208                         /* 15 sec for the message has expired */
 209                         list_del(&cb->list);
 210                         rets = -ETIME;
 211                         goto free;
 212                 }
 213         }
 214         /* if the whole message will fit remove it from the list */
 215         if (cb->buf_idx >= *offset && length >= (cb->buf_idx - *offset))
 216                 list_del(&cb->list);
 217         else if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
 218                 /* end of the message has been reached */
 219                 list_del(&cb->list);
 220                 rets = 0;
 221                 goto free;
 222         }
 223                 /* else means that not full buffer will be read and do not
 224                  * remove message from deletion list
 225                  */
 226
 227         dev_dbg(dev->dev, "amthif cb->response_buffer size - %d\n",
 228             cb->response_buffer.size);
 229         dev_dbg(dev->dev, "amthif cb->buf_idx - %lu\n", cb->buf_idx);
 230
 231         /* length is being truncated to PAGE_SIZE, however,
 232          * the buf_idx may point beyond */
 233         length = min_t(size_t, length, (cb->buf_idx - *offset));
 234
 235         if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length)) {
 236                 dev_dbg(dev->dev, "failed to copy data to userland\n");
 237                 rets = -EFAULT;
 238         } else {
 239                 rets = length;
 240                 if ((*offset + length) < cb->buf_idx) {
 241                         *offset += length;
 242                         goto out;
 243                 }
 244         }
 245 free:
 246         dev_dbg(dev->dev, "free amthif cb memory.\n");
 247         *offset = 0;
 248         mei_io_cb_free(cb);
 249 out:
 250         return rets;
 251 }
 252
 253 /**
 254  * mei_amthif_send_cmd - send amthif command to the ME
 255  *
 256  * @dev: the device structure
 257  * @cb: mei call back struct
 258  *
 259  * returns 0 on success, <0 on failure.
 260  *
 261  */
 262 static int mei_amthif_send_cmd(struct mei_device *dev, struct mei_cl_cb *cb)
 263 {
 264         struct mei_msg_hdr mei_hdr;
 265         int ret;
 266
 267         if (!dev || !cb)
 268                 return -ENODEV;
 269
 270         dev_dbg(dev->dev, "write data to amthif client.\n");
 271
 272         dev->iamthif_state = MEI_IAMTHIF_WRITING;
 273         dev->iamthif_current_cb = cb;
 274         dev->iamthif_file_object = cb->file_object;
 275         dev->iamthif_canceled = false;
 276         dev->iamthif_ioctl = true;
 277         dev->iamthif_msg_buf_size = cb->request_buffer.size;
 278         memcpy(dev->iamthif_msg_buf, cb->request_buffer.data,
 279                cb->request_buffer.size);
 280
 281         ret = mei_cl_flow_ctrl_creds(&dev->iamthif_cl);
 282         if (ret < 0)
 283                 return ret;
 284
 285         if (ret && mei_hbuf_acquire(dev)) {
 286                 ret = 0;
 287                 if (cb->request_buffer.size > mei_hbuf_max_len(dev)) {
 288                         mei_hdr.length = mei_hbuf_max_len(dev);
 289                         mei_hdr.msg_complete = 0;
 290                 } else {
 291                         mei_hdr.length = cb->request_buffer.size;
 292                         mei_hdr.msg_complete = 1;
 293                 }
 294
 295                 mei_hdr.host_addr = dev->iamthif_cl.host_client_id;
 296                 mei_hdr.me_addr = dev->iamthif_cl.me_client_id;
 297                 mei_hdr.reserved = 0;
 298                 mei_hdr.internal = 0;
 299                 dev->iamthif_msg_buf_index += mei_hdr.length;
 300                 ret = mei_write_message(dev, &mei_hdr, dev->iamthif_msg_buf);
 301                 if (ret)
 302                         return ret;
 303
 304                 if (mei_hdr.msg_complete) {
 305                         if (mei_cl_flow_ctrl_reduce(&dev->iamthif_cl))
 306                                 return -EIO;
 307                         dev->iamthif_flow_control_pending = true;
 308                         dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
 309                         dev_dbg(dev->dev, "add amthif cb to write waiting list\n");
 310                         dev->iamthif_current_cb = cb;
 311                         dev->iamthif_file_object = cb->file_object;
 312                         list_add_tail(&cb->list, &dev->write_waiting_list.list);
 313                 } else {
 314                         dev_dbg(dev->dev, "message does not complete, so add amthif cb to write list.\n");
 315                         list_add_tail(&cb->list, &dev->write_list.list);
 316                 }
 317         } else {
 318                 list_add_tail(&cb->list, &dev->write_list.list);
 319         }
 320         return 0;
 321 }
 322
 323 /**
 324  * mei_amthif_write - write amthif data to amthif client
 325  *
 326  * @dev: the device structure
 327  * @cb: mei call back struct
 328  *
 329  * returns 0 on success, <0 on failure.
 330  *
 331  */
 332 int mei_amthif_write(struct mei_device *dev, struct mei_cl_cb *cb)
 333 {
 334         int ret;
 335
 336         if (!dev || !cb)
 337                 return -ENODEV;
 338
 339         ret = mei_io_cb_alloc_resp_buf(cb, dev->iamthif_mtu);
 340         if (ret)
 341                 return ret;
 342
 343         cb->fop_type = MEI_FOP_WRITE;
 344
 345         if (!list_empty(&dev->amthif_cmd_list.list) ||
 346             dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 347                 dev_dbg(dev->dev,
 348                         "amthif state = %d\n", dev->iamthif_state);
 349                 dev_dbg(dev->dev, "AMTHIF: add cb to the wait list\n");
 350                 list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
 351                 return 0;
 352         }
 353         return mei_amthif_send_cmd(dev, cb);
 354 }
 355 /**
 356  * mei_amthif_run_next_cmd
 357  *
 358  * @dev: the device structure
 359  *
 360  * returns 0 on success, <0 on failure.
 361  */
 362 void mei_amthif_run_next_cmd(struct mei_device *dev)
 363 {
 364         struct mei_cl_cb *cb;
 365         struct mei_cl_cb *next;
 366         int status;
 367
 368         if (!dev)
 369                 return;
 370
 371         dev->iamthif_msg_buf_size = 0;
 372         dev->iamthif_msg_buf_index = 0;
 373         dev->iamthif_canceled = false;
 374         dev->iamthif_ioctl = true;
 375         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 376         dev->iamthif_timer = 0;
 377         dev->iamthif_file_object = NULL;
 378
 379         dev_dbg(dev->dev, "complete amthif cmd_list cb.\n");
 380
 381         list_for_each_entry_safe(cb, next, &dev->amthif_cmd_list.list, list) {
 382                 list_del(&cb->list);
 383                 if (!cb->cl)
 384                         continue;
 385                 status = mei_amthif_send_cmd(dev, cb);
 386                 if (status)
 387                         dev_warn(dev->dev, "amthif write failed status = %d\n",
 388                                                 status);
 389                 break;
 390         }
 391 }
 392
 393
 394 unsigned int mei_amthif_poll(struct mei_device *dev,
 395                 struct file *file, poll_table *wait)
 396 {
 397         unsigned int mask = 0;
 398
 399         poll_wait(file, &dev->iamthif_cl.wait, wait);
 400
 401         mutex_lock(&dev->device_lock);
 402         if (!mei_cl_is_connected(&dev->iamthif_cl)) {
 403
 404                 mask = POLLERR;
 405
 406         } else if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
 407                    dev->iamthif_file_object == file) {
 408
 409                 mask |= (POLLIN | POLLRDNORM);
 410                 dev_dbg(dev->dev, "run next amthif cb\n");
 411                 mei_amthif_run_next_cmd(dev);
 412         }
 413         mutex_unlock(&dev->device_lock);
 414
 415         return mask;
 416 }
 417
 418
 419
 420 /**
 421  * mei_amthif_irq_write - write iamthif command in irq thread context.
 422  *
 423  * @dev: the device structure.
 424  * @cb_pos: callback block.
 425  * @cl: private data of the file object.
 426  * @cmpl_list: complete list.
 427  *
 428  * returns 0, OK; otherwise, error.
 429  */
 430 int mei_amthif_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 431                          struct mei_cl_cb *cmpl_list)
 432 {
 433         struct mei_device *dev = cl->dev;
 434         struct mei_msg_hdr mei_hdr;
 435         size_t len = dev->iamthif_msg_buf_size - dev->iamthif_msg_buf_index;
 436         u32 msg_slots = mei_data2slots(len);
 437         int slots;
 438         int rets;
 439
 440         rets = mei_cl_flow_ctrl_creds(cl);
 441         if (rets < 0)
 442                 return rets;
 443
 444         if (rets == 0) {
 445                 cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
 446                 return 0;
 447         }
 448
 449         mei_hdr.host_addr = cl->host_client_id;
 450         mei_hdr.me_addr = cl->me_client_id;
 451         mei_hdr.reserved = 0;
 452         mei_hdr.internal = 0;
 453
 454         slots = mei_hbuf_empty_slots(dev);
 455
 456         if (slots >= msg_slots) {
 457                 mei_hdr.length = len;
 458                 mei_hdr.msg_complete = 1;
 459         /* Split the message only if we can write the whole host buffer */
 460         } else if (slots == dev->hbuf_depth) {
 461                 msg_slots = slots;
 462                 len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
 463                 mei_hdr.length = len;
 464                 mei_hdr.msg_complete = 0;
 465         } else {
 466                 /* wait for next time the host buffer is empty */
 467                 return 0;
 468         }
 469
 470         dev_dbg(dev->dev, MEI_HDR_FMT,  MEI_HDR_PRM(&mei_hdr));
 471
 472         rets = mei_write_message(dev, &mei_hdr,
 473                         dev->iamthif_msg_buf + dev->iamthif_msg_buf_index);
 474         if (rets) {
 475                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 476                 cl->status = rets;
 477                 list_del(&cb->list);
 478                 return rets;
 479         }
 480
 481         if (mei_cl_flow_ctrl_reduce(cl))
 482                 return -EIO;
 483
 484         dev->iamthif_msg_buf_index += mei_hdr.length;
 485         cl->status = 0;
 486
 487         if (mei_hdr.msg_complete) {
 488                 dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
 489                 dev->iamthif_flow_control_pending = true;
 490
 491                 /* save iamthif cb sent to amthif client */
 492                 cb->buf_idx = dev->iamthif_msg_buf_index;
 493                 dev->iamthif_current_cb = cb;
 494
 495                 list_move_tail(&cb->list, &dev->write_waiting_list.list);
 496         }
 497
 498
 499         return 0;
 500 }
 501
 502 /**
 503  * mei_amthif_irq_read_message - read routine after ISR to
 504  *                      handle the read amthif message
 505  *
 506  * @dev: the device structure
 507  * @mei_hdr: header of amthif message
 508  * @complete_list: An instance of our list structure
 509  *
 510  * returns 0 on success, <0 on failure.
 511  */
 512 int mei_amthif_irq_read_msg(struct mei_device *dev,
 513                             struct mei_msg_hdr *mei_hdr,
 514                             struct mei_cl_cb *complete_list)
 515 {
 516         struct mei_cl_cb *cb;
 517         unsigned char *buffer;
 518
 519         BUG_ON(mei_hdr->me_addr != dev->iamthif_cl.me_client_id);
 520         BUG_ON(dev->iamthif_state != MEI_IAMTHIF_READING);
 521
 522         buffer = dev->iamthif_msg_buf + dev->iamthif_msg_buf_index;
 523         BUG_ON(dev->iamthif_mtu < dev->iamthif_msg_buf_index + mei_hdr->length);
 524
 525         mei_read_slots(dev, buffer, mei_hdr->length);
 526
 527         dev->iamthif_msg_buf_index += mei_hdr->length;
 528
 529         if (!mei_hdr->msg_complete)
 530                 return 0;
 531
 532         dev_dbg(dev->dev, "amthif_message_buffer_index =%d\n",
 533                         mei_hdr->length);
 534
 535         dev_dbg(dev->dev, "completed amthif read.\n ");
 536         if (!dev->iamthif_current_cb)
 537                 return -ENODEV;
 538
 539         cb = dev->iamthif_current_cb;
 540         dev->iamthif_current_cb = NULL;
 541
 542         if (!cb->cl)
 543                 return -ENODEV;
 544
 545         dev->iamthif_stall_timer = 0;
 546         cb->buf_idx = dev->iamthif_msg_buf_index;
 547         cb->read_time = jiffies;
 548         if (dev->iamthif_ioctl) {
 549                 /* found the iamthif cb */
 550                 dev_dbg(dev->dev, "complete the amthif read cb.\n ");
 551                 dev_dbg(dev->dev, "add the amthif read cb to complete.\n ");
 552                 list_add_tail(&cb->list, &complete_list->list);
 553         }
 554         return 0;
 555 }
 556
 557 /**
 558  * mei_amthif_irq_read - prepares to read amthif data.
 559  *
 560  * @dev: the device structure.
 561  * @slots: free slots.
 562  *
 563  * returns 0, OK; otherwise, error.
 564  */
 565 int mei_amthif_irq_read(struct mei_device *dev, s32 *slots)
 566 {
 567         u32 msg_slots = mei_data2slots(sizeof(struct hbm_flow_control));
 568
 569         if (*slots < msg_slots)
 570                 return -EMSGSIZE;
 571
 572         *slots -= msg_slots;
 573
 574         if (mei_hbm_cl_flow_control_req(dev, &dev->iamthif_cl)) {
 575                 dev_dbg(dev->dev, "iamthif flow control failed\n");
 576                 return -EIO;
 577         }
 578
 579         dev_dbg(dev->dev, "iamthif flow control success\n");
 580         dev->iamthif_state = MEI_IAMTHIF_READING;
 581         dev->iamthif_flow_control_pending = false;
 582         dev->iamthif_msg_buf_index = 0;
 583         dev->iamthif_msg_buf_size = 0;
 584         dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
 585         dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
 586         return 0;
 587 }
 588
 589 /**
 590  * mei_amthif_complete - complete amthif callback.
 591  *
 592  * @dev: the device structure.
 593  * @cb_pos: callback block.
 594  */
 595 void mei_amthif_complete(struct mei_device *dev, struct mei_cl_cb *cb)
 596 {
 597         if (dev->iamthif_canceled != 1) {
 598                 dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
 599                 dev->iamthif_stall_timer = 0;
 600                 memcpy(cb->response_buffer.data,
 601                                 dev->iamthif_msg_buf,
 602                                 dev->iamthif_msg_buf_index);
 603                 list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
 604                 dev_dbg(dev->dev, "amthif read completed\n");
 605                 dev->iamthif_timer = jiffies;
 606                 dev_dbg(dev->dev, "dev->iamthif_timer = %ld\n",
 607                                 dev->iamthif_timer);
 608         } else {
 609                 mei_amthif_run_next_cmd(dev);
 610         }
 611
 612         dev_dbg(dev->dev, "completing amthif call back.\n");
 613         wake_up_interruptible(&dev->iamthif_cl.wait);
 614 }
 615
 616 /**
 617  * mei_clear_list - removes all callbacks associated with file
 618  *              from mei_cb_list
 619  *
 620  * @dev: device structure.
 621  * @file: file structure
 622  * @mei_cb_list: callbacks list
 623  *
 624  * mei_clear_list is called to clear resources associated with file
 625  * when application calls close function or Ctrl-C was pressed
 626  *
 627  * returns true if callback removed from the list, false otherwise
 628  */
 629 static bool mei_clear_list(struct mei_device *dev,
 630                 const struct file *file, struct list_head *mei_cb_list)
 631 {
 632         struct mei_cl_cb *cb_pos = NULL;
 633         struct mei_cl_cb *cb_next = NULL;
 634         bool removed = false;
 635
 636         /* list all list member */
 637         list_for_each_entry_safe(cb_pos, cb_next, mei_cb_list, list) {
 638                 /* check if list member associated with a file */
 639                 if (file == cb_pos->file_object) {
 640                         /* remove member from the list */
 641                         list_del(&cb_pos->list);
 642                         /* check if cb equal to current iamthif cb */
 643                         if (dev->iamthif_current_cb == cb_pos) {
 644                                 dev->iamthif_current_cb = NULL;
 645                                 /* send flow control to iamthif client */
 646                                 mei_hbm_cl_flow_control_req(dev,
 647                                                         &dev->iamthif_cl);
 648                         }
 649                         /* free all allocated buffers */
 650                         mei_io_cb_free(cb_pos);
 651                         cb_pos = NULL;
 652                         removed = true;
 653                 }
 654         }
 655         return removed;
 656 }
 657
 658 /**
 659  * mei_clear_lists - removes all callbacks associated with file
 660  *
 661  * @dev: device structure
 662  * @file: file structure
 663  *
 664  * mei_clear_lists is called to clear resources associated with file
 665  * when application calls close function or Ctrl-C was pressed
 666  *
 667  * returns true if callback removed from the list, false otherwise
 668  */
 669 static bool mei_clear_lists(struct mei_device *dev, struct file *file)
 670 {
 671         bool removed = false;
 672
 673         /* remove callbacks associated with a file */
 674         mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
 675         if (mei_clear_list(dev, file, &dev->amthif_rd_complete_list.list))
 676                 removed = true;
 677
 678         mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
 679
 680         if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
 681                 removed = true;
 682
 683         if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
 684                 removed = true;
 685
 686         if (mei_clear_list(dev, file, &dev->write_list.list))
 687                 removed = true;
 688
 689         /* check if iamthif_current_cb not NULL */
 690         if (dev->iamthif_current_cb && !removed) {
 691                 /* check file and iamthif current cb association */
 692                 if (dev->iamthif_current_cb->file_object == file) {
 693                         /* remove cb */
 694                         mei_io_cb_free(dev->iamthif_current_cb);
 695                         dev->iamthif_current_cb = NULL;
 696                         removed = true;
 697                 }
 698         }
 699         return removed;
 700 }
 701
 702 /**
 703 * mei_amthif_release - the release function
 704 *
 705 *  @dev: device structure
 706 *  @file: pointer to file structure
 707 *
 708 *  returns 0 on success, <0 on error
 709 */
 710 int mei_amthif_release(struct mei_device *dev, struct file *file)
 711 {
 712         if (dev->iamthif_open_count > 0)
 713                 dev->iamthif_open_count--;
 714
 715         if (dev->iamthif_file_object == file &&
 716             dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 717
 718                 dev_dbg(dev->dev, "amthif canceled iamthif state %d\n",
 719                     dev->iamthif_state);
 720                 dev->iamthif_canceled = true;
 721                 if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
 722                         dev_dbg(dev->dev, "run next amthif iamthif cb\n");
 723                         mei_amthif_run_next_cmd(dev);
 724                 }
 725         }
 726
 727         if (mei_clear_lists(dev, file))
 728                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 729
 730         return 0;
 731 }