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