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