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/pci.h>
  24 #include <linux/ioctl.h>
  25 #include <linux/cdev.h>
  26 #include <linux/list.h>
  27 #include <linux/delay.h>
  28 #include <linux/sched.h>
  29 #include <linux/uuid.h>
  30 #include <linux/jiffies.h>
  31 #include <linux/uaccess.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->pdev->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->pdev->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                 dev_err(&dev->pdev->dev, "amthif: memory allocation for ME message buffer failed.\n");
 101                 return -ENOMEM;
 102         }
 103
 104         dev->iamthif_msg_buf = msg_buf;
 105
 106         ret = mei_cl_link(cl, MEI_IAMTHIF_HOST_CLIENT_ID);
 107
 108         if (ret < 0) {
 109                 dev_err(&dev->pdev->dev,
 110                         "amthif: failed link client %d\n", ret);
 111                 return ret;
 112         }
 113
 114         ret = mei_cl_connect(cl, NULL);
 115
 116         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 117
 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  * returns   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         list_for_each_entry(cb, &dev->amthif_rd_complete_list.list, list)
 134                 if (cb->file_object == file)
 135                         return cb;
 136         return NULL;
 137 }
 138
 139
 140 /**
 141  * mei_amthif_read - read data from AMTHIF client
 142  *
 143  * @dev: the device structure
 144  * @if_num:  minor number
 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  * returns
 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->pdev->dev, "bad file ext.\n");
 169                 return -ETIME;
 170         }
 171
 172         dev_dbg(&dev->pdev->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->pdev->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->pdev->dev, "woke up from sleep\n");
 195         }
 196
 197
 198         dev_dbg(&dev->pdev->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->pdev->dev, "amthif timeout = %lud\n",
 205                                 timeout);
 206
 207                 if  (time_after(jiffies, timeout)) {
 208                         dev_dbg(&dev->pdev->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->pdev->dev, "amthif cb->response_buffer size - %d\n",
 229             cb->response_buffer.size);
 230         dev_dbg(&dev->pdev->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->pdev->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->pdev->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  * returns 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         int ret;
 267
 268         if (!dev || !cb)
 269                 return -ENODEV;
 270
 271         dev_dbg(&dev->pdev->dev, "write data to amthif client.\n");
 272
 273         dev->iamthif_state = MEI_IAMTHIF_WRITING;
 274         dev->iamthif_current_cb = cb;
 275         dev->iamthif_file_object = cb->file_object;
 276         dev->iamthif_canceled = false;
 277         dev->iamthif_ioctl = true;
 278         dev->iamthif_msg_buf_size = cb->request_buffer.size;
 279         memcpy(dev->iamthif_msg_buf, cb->request_buffer.data,
 280                cb->request_buffer.size);
 281
 282         ret = mei_cl_flow_ctrl_creds(&dev->iamthif_cl);
 283         if (ret < 0)
 284                 return ret;
 285
 286         if (ret && mei_hbuf_acquire(dev)) {
 287                 ret = 0;
 288                 if (cb->request_buffer.size > mei_hbuf_max_len(dev)) {
 289                         mei_hdr.length = mei_hbuf_max_len(dev);
 290                         mei_hdr.msg_complete = 0;
 291                 } else {
 292                         mei_hdr.length = cb->request_buffer.size;
 293                         mei_hdr.msg_complete = 1;
 294                 }
 295
 296                 mei_hdr.host_addr = dev->iamthif_cl.host_client_id;
 297                 mei_hdr.me_addr = dev->iamthif_cl.me_client_id;
 298                 mei_hdr.reserved = 0;
 299                 mei_hdr.internal = 0;
 300                 dev->iamthif_msg_buf_index += mei_hdr.length;
 301                 ret = mei_write_message(dev, &mei_hdr, dev->iamthif_msg_buf);
 302                 if (ret)
 303                         return ret;
 304
 305                 if (mei_hdr.msg_complete) {
 306                         if (mei_cl_flow_ctrl_reduce(&dev->iamthif_cl))
 307                                 return -EIO;
 308                         dev->iamthif_flow_control_pending = true;
 309                         dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
 310                         dev_dbg(&dev->pdev->dev, "add amthif cb to write waiting list\n");
 311                         dev->iamthif_current_cb = cb;
 312                         dev->iamthif_file_object = cb->file_object;
 313                         list_add_tail(&cb->list, &dev->write_waiting_list.list);
 314                 } else {
 315                         dev_dbg(&dev->pdev->dev, "message does not complete, so add amthif cb to write list.\n");
 316                         list_add_tail(&cb->list, &dev->write_list.list);
 317                 }
 318         } else {
 319                 list_add_tail(&cb->list, &dev->write_list.list);
 320         }
 321         return 0;
 322 }
 323
 324 /**
 325  * mei_amthif_write - write amthif data to amthif client
 326  *
 327  * @dev: the device structure
 328  * @cb: mei call back struct
 329  *
 330  * returns 0 on success, <0 on failure.
 331  *
 332  */
 333 int mei_amthif_write(struct mei_device *dev, struct mei_cl_cb *cb)
 334 {
 335         int ret;
 336
 337         if (!dev || !cb)
 338                 return -ENODEV;
 339
 340         ret = mei_io_cb_alloc_resp_buf(cb, dev->iamthif_mtu);
 341         if (ret)
 342                 return ret;
 343
 344         cb->fop_type = MEI_FOP_WRITE;
 345
 346         if (!list_empty(&dev->amthif_cmd_list.list) ||
 347             dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 348                 dev_dbg(&dev->pdev->dev,
 349                         "amthif state = %d\n", dev->iamthif_state);
 350                 dev_dbg(&dev->pdev->dev, "AMTHIF: add cb to the wait list\n");
 351                 list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
 352                 return 0;
 353         }
 354         return mei_amthif_send_cmd(dev, cb);
 355 }
 356 /**
 357  * mei_amthif_run_next_cmd
 358  *
 359  * @dev: the device structure
 360  *
 361  * returns 0 on success, <0 on failure.
 362  */
 363 void mei_amthif_run_next_cmd(struct mei_device *dev)
 364 {
 365         struct mei_cl_cb *cb;
 366         struct mei_cl_cb *next;
 367         int status;
 368
 369         if (!dev)
 370                 return;
 371
 372         dev->iamthif_msg_buf_size = 0;
 373         dev->iamthif_msg_buf_index = 0;
 374         dev->iamthif_canceled = false;
 375         dev->iamthif_ioctl = true;
 376         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 377         dev->iamthif_timer = 0;
 378         dev->iamthif_file_object = NULL;
 379
 380         dev_dbg(&dev->pdev->dev, "complete amthif cmd_list cb.\n");
 381
 382         list_for_each_entry_safe(cb, next, &dev->amthif_cmd_list.list, list) {
 383                 list_del(&cb->list);
 384                 if (!cb->cl)
 385                         continue;
 386                 status = mei_amthif_send_cmd(dev, cb);
 387                 if (status)
 388                         dev_warn(&dev->pdev->dev, "amthif write failed status = %d\n",
 389                                                 status);
 390                 break;
 391         }
 392 }
 393
 394
 395 unsigned int mei_amthif_poll(struct mei_device *dev,
 396                 struct file *file, poll_table *wait)
 397 {
 398         unsigned int mask = 0;
 399
 400         poll_wait(file, &dev->iamthif_cl.wait, wait);
 401
 402         mutex_lock(&dev->device_lock);
 403         if (!mei_cl_is_connected(&dev->iamthif_cl)) {
 404
 405                 mask = POLLERR;
 406
 407         } else if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
 408                    dev->iamthif_file_object == file) {
 409
 410                 mask |= (POLLIN | POLLRDNORM);
 411                 dev_dbg(&dev->pdev->dev, "run next amthif cb\n");
 412                 mei_amthif_run_next_cmd(dev);
 413         }
 414         mutex_unlock(&dev->device_lock);
 415
 416         return mask;
 417 }
 418
 419
 420
 421 /**
 422  * mei_amthif_irq_write - write iamthif command in irq thread context.
 423  *
 424  * @dev: the device structure.
 425  * @cb_pos: callback block.
 426  * @cl: private data of the file object.
 427  * @cmpl_list: complete list.
 428  *
 429  * returns 0, OK; otherwise, error.
 430  */
 431 int mei_amthif_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 432                          struct mei_cl_cb *cmpl_list)
 433 {
 434         struct mei_device *dev = cl->dev;
 435         struct mei_msg_hdr mei_hdr;
 436         size_t len = dev->iamthif_msg_buf_size - dev->iamthif_msg_buf_index;
 437         u32 msg_slots = mei_data2slots(len);
 438         int slots;
 439         int rets;
 440
 441         rets = mei_cl_flow_ctrl_creds(cl);
 442         if (rets < 0)
 443                 return rets;
 444
 445         if (rets == 0) {
 446                 cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
 447                 return 0;
 448         }
 449
 450         mei_hdr.host_addr = cl->host_client_id;
 451         mei_hdr.me_addr = cl->me_client_id;
 452         mei_hdr.reserved = 0;
 453         mei_hdr.internal = 0;
 454
 455         slots = mei_hbuf_empty_slots(dev);
 456
 457         if (slots >= msg_slots) {
 458                 mei_hdr.length = len;
 459                 mei_hdr.msg_complete = 1;
 460         /* Split the message only if we can write the whole host buffer */
 461         } else if (slots == dev->hbuf_depth) {
 462                 msg_slots = slots;
 463                 len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
 464                 mei_hdr.length = len;
 465                 mei_hdr.msg_complete = 0;
 466         } else {
 467                 /* wait for next time the host buffer is empty */
 468                 return 0;
 469         }
 470
 471         dev_dbg(&dev->pdev->dev, MEI_HDR_FMT,  MEI_HDR_PRM(&mei_hdr));
 472
 473         rets = mei_write_message(dev, &mei_hdr,
 474                         dev->iamthif_msg_buf + dev->iamthif_msg_buf_index);
 475         if (rets) {
 476                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 477                 cl->status = rets;
 478                 list_del(&cb->list);
 479                 return rets;
 480         }
 481
 482         if (mei_cl_flow_ctrl_reduce(cl))
 483                 return -EIO;
 484
 485         dev->iamthif_msg_buf_index += mei_hdr.length;
 486         cl->status = 0;
 487
 488         if (mei_hdr.msg_complete) {
 489                 dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
 490                 dev->iamthif_flow_control_pending = true;
 491
 492                 /* save iamthif cb sent to amthif client */
 493                 cb->buf_idx = dev->iamthif_msg_buf_index;
 494                 dev->iamthif_current_cb = cb;
 495
 496                 list_move_tail(&cb->list, &dev->write_waiting_list.list);
 497         }
 498
 499
 500         return 0;
 501 }
 502
 503 /**
 504  * mei_amthif_irq_read_message - read routine after ISR to
 505  *                      handle the read amthif message
 506  *
 507  * @dev: the device structure
 508  * @mei_hdr: header of amthif message
 509  * @complete_list: An instance of our list structure
 510  *
 511  * returns 0 on success, <0 on failure.
 512  */
 513 int mei_amthif_irq_read_msg(struct mei_device *dev,
 514                             struct mei_msg_hdr *mei_hdr,
 515                             struct mei_cl_cb *complete_list)
 516 {
 517         struct mei_cl_cb *cb;
 518         unsigned char *buffer;
 519
 520         BUG_ON(mei_hdr->me_addr != dev->iamthif_cl.me_client_id);
 521         BUG_ON(dev->iamthif_state != MEI_IAMTHIF_READING);
 522
 523         buffer = dev->iamthif_msg_buf + dev->iamthif_msg_buf_index;
 524         BUG_ON(dev->iamthif_mtu < dev->iamthif_msg_buf_index + mei_hdr->length);
 525
 526         mei_read_slots(dev, buffer, mei_hdr->length);
 527
 528         dev->iamthif_msg_buf_index += mei_hdr->length;
 529
 530         if (!mei_hdr->msg_complete)
 531                 return 0;
 532
 533         dev_dbg(&dev->pdev->dev, "amthif_message_buffer_index =%d\n",
 534                         mei_hdr->length);
 535
 536         dev_dbg(&dev->pdev->dev, "completed amthif read.\n ");
 537         if (!dev->iamthif_current_cb)
 538                 return -ENODEV;
 539
 540         cb = dev->iamthif_current_cb;
 541         dev->iamthif_current_cb = NULL;
 542
 543         if (!cb->cl)
 544                 return -ENODEV;
 545
 546         dev->iamthif_stall_timer = 0;
 547         cb->buf_idx = dev->iamthif_msg_buf_index;
 548         cb->read_time = jiffies;
 549         if (dev->iamthif_ioctl) {
 550                 /* found the iamthif cb */
 551                 dev_dbg(&dev->pdev->dev, "complete the amthif read cb.\n ");
 552                 dev_dbg(&dev->pdev->dev, "add the amthif read cb to complete.\n ");
 553                 list_add_tail(&cb->list, &complete_list->list);
 554         }
 555         return 0;
 556 }
 557
 558 /**
 559  * mei_amthif_irq_read - prepares to read amthif data.
 560  *
 561  * @dev: the device structure.
 562  * @slots: free slots.
 563  *
 564  * returns 0, OK; otherwise, error.
 565  */
 566 int mei_amthif_irq_read(struct mei_device *dev, s32 *slots)
 567 {
 568         u32 msg_slots = mei_data2slots(sizeof(struct hbm_flow_control));
 569
 570         if (*slots < msg_slots)
 571                 return -EMSGSIZE;
 572
 573         *slots -= msg_slots;
 574
 575         if (mei_hbm_cl_flow_control_req(dev, &dev->iamthif_cl)) {
 576                 dev_dbg(&dev->pdev->dev, "iamthif flow control failed\n");
 577                 return -EIO;
 578         }
 579
 580         dev_dbg(&dev->pdev->dev, "iamthif flow control success\n");
 581         dev->iamthif_state = MEI_IAMTHIF_READING;
 582         dev->iamthif_flow_control_pending = false;
 583         dev->iamthif_msg_buf_index = 0;
 584         dev->iamthif_msg_buf_size = 0;
 585         dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
 586         dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
 587         return 0;
 588 }
 589
 590 /**
 591  * mei_amthif_complete - complete amthif callback.
 592  *
 593  * @dev: the device structure.
 594  * @cb_pos: callback block.
 595  */
 596 void mei_amthif_complete(struct mei_device *dev, struct mei_cl_cb *cb)
 597 {
 598         if (dev->iamthif_canceled != 1) {
 599                 dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
 600                 dev->iamthif_stall_timer = 0;
 601                 memcpy(cb->response_buffer.data,
 602                                 dev->iamthif_msg_buf,
 603                                 dev->iamthif_msg_buf_index);
 604                 list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
 605                 dev_dbg(&dev->pdev->dev, "amthif read completed\n");
 606                 dev->iamthif_timer = jiffies;
 607                 dev_dbg(&dev->pdev->dev, "dev->iamthif_timer = %ld\n",
 608                                 dev->iamthif_timer);
 609         } else {
 610                 mei_amthif_run_next_cmd(dev);
 611         }
 612
 613         dev_dbg(&dev->pdev->dev, "completing amthif call back.\n");
 614         wake_up_interruptible(&dev->iamthif_cl.wait);
 615 }
 616
 617 /**
 618  * mei_clear_list - removes all callbacks associated with file
 619  *              from mei_cb_list
 620  *
 621  * @dev: device structure.
 622  * @file: file structure
 623  * @mei_cb_list: callbacks list
 624  *
 625  * mei_clear_list is called to clear resources associated with file
 626  * when application calls close function or Ctrl-C was pressed
 627  *
 628  * returns true if callback removed from the list, false otherwise
 629  */
 630 static bool mei_clear_list(struct mei_device *dev,
 631                 const struct file *file, struct list_head *mei_cb_list)
 632 {
 633         struct mei_cl_cb *cb_pos = NULL;
 634         struct mei_cl_cb *cb_next = NULL;
 635         bool removed = false;
 636
 637         /* list all list member */
 638         list_for_each_entry_safe(cb_pos, cb_next, mei_cb_list, list) {
 639                 /* check if list member associated with a file */
 640                 if (file == cb_pos->file_object) {
 641                         /* remove member from the list */
 642                         list_del(&cb_pos->list);
 643                         /* check if cb equal to current iamthif cb */
 644                         if (dev->iamthif_current_cb == cb_pos) {
 645                                 dev->iamthif_current_cb = NULL;
 646                                 /* send flow control to iamthif client */
 647                                 mei_hbm_cl_flow_control_req(dev,
 648                                                         &dev->iamthif_cl);
 649                         }
 650                         /* free all allocated buffers */
 651                         mei_io_cb_free(cb_pos);
 652                         cb_pos = NULL;
 653                         removed = true;
 654                 }
 655         }
 656         return removed;
 657 }
 658
 659 /**
 660  * mei_clear_lists - removes all callbacks associated with file
 661  *
 662  * @dev: device structure
 663  * @file: file structure
 664  *
 665  * mei_clear_lists is called to clear resources associated with file
 666  * when application calls close function or Ctrl-C was pressed
 667  *
 668  * returns true if callback removed from the list, false otherwise
 669  */
 670 static bool mei_clear_lists(struct mei_device *dev, struct file *file)
 671 {
 672         bool removed = false;
 673
 674         /* remove callbacks associated with a file */
 675         mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
 676         if (mei_clear_list(dev, file, &dev->amthif_rd_complete_list.list))
 677                 removed = true;
 678
 679         mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
 680
 681         if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
 682                 removed = true;
 683
 684         if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
 685                 removed = true;
 686
 687         if (mei_clear_list(dev, file, &dev->write_list.list))
 688                 removed = true;
 689
 690         /* check if iamthif_current_cb not NULL */
 691         if (dev->iamthif_current_cb && !removed) {
 692                 /* check file and iamthif current cb association */
 693                 if (dev->iamthif_current_cb->file_object == file) {
 694                         /* remove cb */
 695                         mei_io_cb_free(dev->iamthif_current_cb);
 696                         dev->iamthif_current_cb = NULL;
 697                         removed = true;
 698                 }
 699         }
 700         return removed;
 701 }
 702
 703 /**
 704 * mei_amthif_release - the release function
 705 *
 706 *  @dev: device structure
 707 *  @file: pointer to file structure
 708 *
 709 *  returns 0 on success, <0 on error
 710 */
 711 int mei_amthif_release(struct mei_device *dev, struct file *file)
 712 {
 713         if (dev->iamthif_open_count > 0)
 714                 dev->iamthif_open_count--;
 715
 716         if (dev->iamthif_file_object == file &&
 717             dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 718
 719                 dev_dbg(&dev->pdev->dev, "amthif canceled iamthif state %d\n",
 720                     dev->iamthif_state);
 721                 dev->iamthif_canceled = true;
 722                 if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
 723                         dev_dbg(&dev->pdev->dev, "run next amthif iamthif cb\n");
 724                         mei_amthif_run_next_cmd(dev);
 725                 }
 726         }
 727
 728         if (mei_clear_lists(dev, file))
 729                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 730
 731         return 0;
 732 }