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  * Return: 0 on success, <0 on failure.
  68  */
  69 int mei_amthif_host_init(struct mei_device *dev)
  70 {
  71         struct mei_cl *cl = &dev->iamthif_cl;
  72         struct mei_me_client *me_cl;
  73         unsigned char *msg_buf;
  74         int ret;
  75
  76         dev->iamthif_state = MEI_IAMTHIF_IDLE;
  77
  78         mei_cl_init(cl, dev);
  79
  80         me_cl = mei_me_cl_by_uuid(dev, &mei_amthif_guid);
  81         if (!me_cl) {
  82                 dev_info(dev->dev, "amthif: failed to find the client");
  83                 return -ENOTTY;
  84         }
  85
  86         cl->me_client_id = me_cl->client_id;
  87         cl->cl_uuid = me_cl->props.protocol_name;
  88
  89         /* Assign iamthif_mtu to the value received from ME  */
  90
  91         dev->iamthif_mtu = me_cl->props.max_msg_length;
  92         dev_dbg(dev->dev, "IAMTHIF_MTU = %d\n", dev->iamthif_mtu);
  93
  94         kfree(dev->iamthif_msg_buf);
  95         dev->iamthif_msg_buf = NULL;
  96
  97         /* allocate storage for ME message buffer */
  98         msg_buf = kcalloc(dev->iamthif_mtu,
  99                         sizeof(unsigned char), GFP_KERNEL);
 100         if (!msg_buf)
 101                 return -ENOMEM;
 102
 103         dev->iamthif_msg_buf = msg_buf;
 104
 105         ret = mei_cl_link(cl, MEI_IAMTHIF_HOST_CLIENT_ID);
 106
 107         if (ret < 0) {
 108                 dev_err(dev->dev,
 109                         "amthif: failed link client %d\n", ret);
 110                 return ret;
 111         }
 112
 113         ret = mei_cl_connect(cl, NULL);
 114
 115         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 116
 117         return ret;
 118 }
 119
 120 /**
 121  * mei_amthif_find_read_list_entry - finds a amthilist entry for current file
 122  *
 123  * @dev: the device structure
 124  * @file: pointer to file object
 125  *
 126  * Return:   returned a list entry on success, NULL on failure.
 127  */
 128 struct mei_cl_cb *mei_amthif_find_read_list_entry(struct mei_device *dev,
 129                                                 struct file *file)
 130 {
 131         struct mei_cl_cb *cb;
 132
 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  * @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  * Return:
 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  * Return: 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  * Return: 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 - send next amt command from queue
 357  *
 358  * @dev: the device structure
 359  */
 360 void mei_amthif_run_next_cmd(struct mei_device *dev)
 361 {
 362         struct mei_cl_cb *cb;
 363         struct mei_cl_cb *next;
 364         int status;
 365
 366         if (!dev)
 367                 return;
 368
 369         dev->iamthif_msg_buf_size = 0;
 370         dev->iamthif_msg_buf_index = 0;
 371         dev->iamthif_canceled = false;
 372         dev->iamthif_ioctl = true;
 373         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 374         dev->iamthif_timer = 0;
 375         dev->iamthif_file_object = NULL;
 376
 377         dev_dbg(dev->dev, "complete amthif cmd_list cb.\n");
 378
 379         list_for_each_entry_safe(cb, next, &dev->amthif_cmd_list.list, list) {
 380                 list_del(&cb->list);
 381                 if (!cb->cl)
 382                         continue;
 383                 status = mei_amthif_send_cmd(dev, cb);
 384                 if (status)
 385                         dev_warn(dev->dev, "amthif write failed status = %d\n",
 386                                                 status);
 387                 break;
 388         }
 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         if (!cb->cl)
 540                 return -ENODEV;
 541
 542         dev->iamthif_stall_timer = 0;
 543         cb->buf_idx = dev->iamthif_msg_buf_index;
 544         cb->read_time = jiffies;
 545         if (dev->iamthif_ioctl) {
 546                 /* found the iamthif cb */
 547                 dev_dbg(dev->dev, "complete the amthif read cb.\n ");
 548                 dev_dbg(dev->dev, "add the amthif read cb to complete.\n ");
 549                 list_add_tail(&cb->list, &complete_list->list);
 550         }
 551         return 0;
 552 }
 553
 554 /**
 555  * mei_amthif_irq_read - prepares to read amthif data.
 556  *
 557  * @dev: the device structure.
 558  * @slots: free slots.
 559  *
 560  * Return: 0, OK; otherwise, error.
 561  */
 562 int mei_amthif_irq_read(struct mei_device *dev, s32 *slots)
 563 {
 564         u32 msg_slots = mei_data2slots(sizeof(struct hbm_flow_control));
 565
 566         if (*slots < msg_slots)
 567                 return -EMSGSIZE;
 568
 569         *slots -= msg_slots;
 570
 571         if (mei_hbm_cl_flow_control_req(dev, &dev->iamthif_cl)) {
 572                 dev_dbg(dev->dev, "iamthif flow control failed\n");
 573                 return -EIO;
 574         }
 575
 576         dev_dbg(dev->dev, "iamthif flow control success\n");
 577         dev->iamthif_state = MEI_IAMTHIF_READING;
 578         dev->iamthif_flow_control_pending = false;
 579         dev->iamthif_msg_buf_index = 0;
 580         dev->iamthif_msg_buf_size = 0;
 581         dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
 582         dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
 583         return 0;
 584 }
 585
 586 /**
 587  * mei_amthif_complete - complete amthif callback.
 588  *
 589  * @dev: the device structure.
 590  * @cb: callback block.
 591  */
 592 void mei_amthif_complete(struct mei_device *dev, struct mei_cl_cb *cb)
 593 {
 594         if (dev->iamthif_canceled != 1) {
 595                 dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
 596                 dev->iamthif_stall_timer = 0;
 597                 memcpy(cb->response_buffer.data,
 598                                 dev->iamthif_msg_buf,
 599                                 dev->iamthif_msg_buf_index);
 600                 list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
 601                 dev_dbg(dev->dev, "amthif read completed\n");
 602                 dev->iamthif_timer = jiffies;
 603                 dev_dbg(dev->dev, "dev->iamthif_timer = %ld\n",
 604                                 dev->iamthif_timer);
 605         } else {
 606                 mei_amthif_run_next_cmd(dev);
 607         }
 608
 609         dev_dbg(dev->dev, "completing amthif call back.\n");
 610         wake_up_interruptible(&dev->iamthif_cl.wait);
 611 }
 612
 613 /**
 614  * mei_clear_list - removes all callbacks associated with file
 615  *              from mei_cb_list
 616  *
 617  * @dev: device structure.
 618  * @file: file structure
 619  * @mei_cb_list: callbacks list
 620  *
 621  * mei_clear_list is called to clear resources associated with file
 622  * when application calls close function or Ctrl-C was pressed
 623  *
 624  * Return: true if callback removed from the list, false otherwise
 625  */
 626 static bool mei_clear_list(struct mei_device *dev,
 627                 const struct file *file, struct list_head *mei_cb_list)
 628 {
 629         struct mei_cl_cb *cb_pos = NULL;
 630         struct mei_cl_cb *cb_next = NULL;
 631         bool removed = false;
 632
 633         /* list all list member */
 634         list_for_each_entry_safe(cb_pos, cb_next, mei_cb_list, list) {
 635                 /* check if list member associated with a file */
 636                 if (file == cb_pos->file_object) {
 637                         /* remove member from the list */
 638                         list_del(&cb_pos->list);
 639                         /* check if cb equal to current iamthif cb */
 640                         if (dev->iamthif_current_cb == cb_pos) {
 641                                 dev->iamthif_current_cb = NULL;
 642                                 /* send flow control to iamthif client */
 643                                 mei_hbm_cl_flow_control_req(dev,
 644                                                         &dev->iamthif_cl);
 645                         }
 646                         /* free all allocated buffers */
 647                         mei_io_cb_free(cb_pos);
 648                         cb_pos = NULL;
 649                         removed = true;
 650                 }
 651         }
 652         return removed;
 653 }
 654
 655 /**
 656  * mei_clear_lists - removes all callbacks associated with file
 657  *
 658  * @dev: device structure
 659  * @file: file structure
 660  *
 661  * mei_clear_lists is called to clear resources associated with file
 662  * when application calls close function or Ctrl-C was pressed
 663  *
 664  * Return: true if callback removed from the list, false otherwise
 665  */
 666 static bool mei_clear_lists(struct mei_device *dev, struct file *file)
 667 {
 668         bool removed = false;
 669
 670         /* remove callbacks associated with a file */
 671         mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
 672         if (mei_clear_list(dev, file, &dev->amthif_rd_complete_list.list))
 673                 removed = true;
 674
 675         mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
 676
 677         if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
 678                 removed = true;
 679
 680         if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
 681                 removed = true;
 682
 683         if (mei_clear_list(dev, file, &dev->write_list.list))
 684                 removed = true;
 685
 686         /* check if iamthif_current_cb not NULL */
 687         if (dev->iamthif_current_cb && !removed) {
 688                 /* check file and iamthif current cb association */
 689                 if (dev->iamthif_current_cb->file_object == file) {
 690                         /* remove cb */
 691                         mei_io_cb_free(dev->iamthif_current_cb);
 692                         dev->iamthif_current_cb = NULL;
 693                         removed = true;
 694                 }
 695         }
 696         return removed;
 697 }
 698
 699 /**
 700 * mei_amthif_release - the release function
 701 *
 702 *  @dev: device structure
 703 *  @file: pointer to file structure
 704 *
 705 *  Return: 0 on success, <0 on error
 706 */
 707 int mei_amthif_release(struct mei_device *dev, struct file *file)
 708 {
 709         if (dev->iamthif_open_count > 0)
 710                 dev->iamthif_open_count--;
 711
 712         if (dev->iamthif_file_object == file &&
 713             dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 714
 715                 dev_dbg(dev->dev, "amthif canceled iamthif state %d\n",
 716                     dev->iamthif_state);
 717                 dev->iamthif_canceled = true;
 718                 if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
 719                         dev_dbg(dev->dev, "run next amthif iamthif cb\n");
 720                         mei_amthif_run_next_cmd(dev);
 721                 }
 722         }
 723
 724         if (mei_clear_lists(dev, file))
 725                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 726
 727         return 0;
 728 }