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         unsigned char *msg_buf;
  72         int ret, i;
  73
  74         dev->iamthif_state = MEI_IAMTHIF_IDLE;
  75
  76         mei_cl_init(cl, dev);
  77
  78         i = mei_me_cl_by_uuid(dev, &mei_amthif_guid);
  79         if (i < 0) {
  80                 dev_info(&dev->pdev->dev,
  81                         "amthif: failed to find the client %d\n", i);
  82                 return -ENOTTY;
  83         }
  84
  85         cl->me_client_id = dev->me_clients[i].client_id;
  86
  87         /* Assign iamthif_mtu to the value received from ME  */
  88
  89         dev->iamthif_mtu = dev->me_clients[i].props.max_msg_length;
  90         dev_dbg(&dev->pdev->dev, "IAMTHIF_MTU = %d\n",
  91                         dev->me_clients[i].props.max_msg_length);
  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         cl->state = MEI_FILE_CONNECTING;
 115
 116         ret = mei_cl_connect(cl, NULL);
 117
 118         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 119
 120         return ret;
 121 }
 122
 123 /**
 124  * mei_amthif_find_read_list_entry - finds a amthilist entry for current file
 125  *
 126  * @dev: the device structure
 127  * @file: pointer to file object
 128  *
 129  * returns   returned a list entry on success, NULL on failure.
 130  */
 131 struct mei_cl_cb *mei_amthif_find_read_list_entry(struct mei_device *dev,
 132                                                 struct file *file)
 133 {
 134         struct mei_cl_cb *cb;
 135
 136         list_for_each_entry(cb, &dev->amthif_rd_complete_list.list, list) {
 137                 if (cb->cl && cb->cl == &dev->iamthif_cl &&
 138                         cb->file_object == file)
 139                         return cb;
 140         }
 141         return NULL;
 142 }
 143
 144
 145 /**
 146  * mei_amthif_read - read data from AMTHIF client
 147  *
 148  * @dev: the device structure
 149  * @if_num:  minor number
 150  * @file: pointer to file object
 151  * @*ubuf: pointer to user data in user space
 152  * @length: data length to read
 153  * @offset: data read offset
 154  *
 155  * Locking: called under "dev->device_lock" lock
 156  *
 157  * returns
 158  *  returned data length on success,
 159  *  zero if no data to read,
 160  *  negative on failure.
 161  */
 162 int mei_amthif_read(struct mei_device *dev, struct file *file,
 163                char __user *ubuf, size_t length, loff_t *offset)
 164 {
 165         int rets;
 166         int wait_ret;
 167         struct mei_cl_cb *cb = NULL;
 168         struct mei_cl *cl = file->private_data;
 169         unsigned long timeout;
 170         int i;
 171
 172         /* Only possible if we are in timeout */
 173         if (!cl || cl != &dev->iamthif_cl) {
 174                 dev_dbg(&dev->pdev->dev, "bad file ext.\n");
 175                 return -ETIME;
 176         }
 177
 178         i = mei_me_cl_by_id(dev, dev->iamthif_cl.me_client_id);
 179         if (i < 0) {
 180                 dev_dbg(&dev->pdev->dev, "amthif client not found.\n");
 181                 return -ENOTTY;
 182         }
 183         dev_dbg(&dev->pdev->dev, "checking amthif data\n");
 184         cb = mei_amthif_find_read_list_entry(dev, file);
 185
 186         /* Check for if we can block or not*/
 187         if (cb == NULL && file->f_flags & O_NONBLOCK)
 188                 return -EAGAIN;
 189
 190
 191         dev_dbg(&dev->pdev->dev, "waiting for amthif data\n");
 192         while (cb == NULL) {
 193                 /* unlock the Mutex */
 194                 mutex_unlock(&dev->device_lock);
 195
 196                 wait_ret = wait_event_interruptible(dev->iamthif_cl.wait,
 197                         (cb = mei_amthif_find_read_list_entry(dev, file)));
 198
 199                 /* Locking again the Mutex */
 200                 mutex_lock(&dev->device_lock);
 201
 202                 if (wait_ret)
 203                         return -ERESTARTSYS;
 204
 205                 dev_dbg(&dev->pdev->dev, "woke up from sleep\n");
 206         }
 207
 208
 209         dev_dbg(&dev->pdev->dev, "Got amthif data\n");
 210         dev->iamthif_timer = 0;
 211
 212         if (cb) {
 213                 timeout = cb->read_time +
 214                         mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
 215                 dev_dbg(&dev->pdev->dev, "amthif timeout = %lud\n",
 216                                 timeout);
 217
 218                 if  (time_after(jiffies, timeout)) {
 219                         dev_dbg(&dev->pdev->dev, "amthif Time out\n");
 220                         /* 15 sec for the message has expired */
 221                         list_del(&cb->list);
 222                         rets = -ETIME;
 223                         goto free;
 224                 }
 225         }
 226         /* if the whole message will fit remove it from the list */
 227         if (cb->buf_idx >= *offset && length >= (cb->buf_idx - *offset))
 228                 list_del(&cb->list);
 229         else if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
 230                 /* end of the message has been reached */
 231                 list_del(&cb->list);
 232                 rets = 0;
 233                 goto free;
 234         }
 235                 /* else means that not full buffer will be read and do not
 236                  * remove message from deletion list
 237                  */
 238
 239         dev_dbg(&dev->pdev->dev, "amthif cb->response_buffer size - %d\n",
 240             cb->response_buffer.size);
 241         dev_dbg(&dev->pdev->dev, "amthif cb->buf_idx - %lu\n", cb->buf_idx);
 242
 243         /* length is being truncated to PAGE_SIZE, however,
 244          * the buf_idx may point beyond */
 245         length = min_t(size_t, length, (cb->buf_idx - *offset));
 246
 247         if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length)) {
 248                 dev_dbg(&dev->pdev->dev, "failed to copy data to userland\n");
 249                 rets = -EFAULT;
 250         }
 251         else {
 252                 rets = length;
 253                 if ((*offset + length) < cb->buf_idx) {
 254                         *offset += length;
 255                         goto out;
 256                 }
 257         }
 258 free:
 259         dev_dbg(&dev->pdev->dev, "free amthif cb memory.\n");
 260         *offset = 0;
 261         mei_io_cb_free(cb);
 262 out:
 263         return rets;
 264 }
 265
 266 /**
 267  * mei_amthif_send_cmd - send amthif command to the ME
 268  *
 269  * @dev: the device structure
 270  * @cb: mei call back struct
 271  *
 272  * returns 0 on success, <0 on failure.
 273  *
 274  */
 275 static int mei_amthif_send_cmd(struct mei_device *dev, struct mei_cl_cb *cb)
 276 {
 277         struct mei_msg_hdr mei_hdr;
 278         int ret;
 279
 280         if (!dev || !cb)
 281                 return -ENODEV;
 282
 283         dev_dbg(&dev->pdev->dev, "write data to amthif client.\n");
 284
 285         dev->iamthif_state = MEI_IAMTHIF_WRITING;
 286         dev->iamthif_current_cb = cb;
 287         dev->iamthif_file_object = cb->file_object;
 288         dev->iamthif_canceled = false;
 289         dev->iamthif_ioctl = true;
 290         dev->iamthif_msg_buf_size = cb->request_buffer.size;
 291         memcpy(dev->iamthif_msg_buf, cb->request_buffer.data,
 292                cb->request_buffer.size);
 293
 294         ret = mei_cl_flow_ctrl_creds(&dev->iamthif_cl);
 295         if (ret < 0)
 296                 return ret;
 297
 298         if (ret && mei_hbuf_acquire(dev)) {
 299                 ret = 0;
 300                 if (cb->request_buffer.size > mei_hbuf_max_len(dev)) {
 301                         mei_hdr.length = mei_hbuf_max_len(dev);
 302                         mei_hdr.msg_complete = 0;
 303                 } else {
 304                         mei_hdr.length = cb->request_buffer.size;
 305                         mei_hdr.msg_complete = 1;
 306                 }
 307
 308                 mei_hdr.host_addr = dev->iamthif_cl.host_client_id;
 309                 mei_hdr.me_addr = dev->iamthif_cl.me_client_id;
 310                 mei_hdr.reserved = 0;
 311                 mei_hdr.internal = 0;
 312                 dev->iamthif_msg_buf_index += mei_hdr.length;
 313                 ret = mei_write_message(dev, &mei_hdr, dev->iamthif_msg_buf);
 314                 if (ret)
 315                         return ret;
 316
 317                 if (mei_hdr.msg_complete) {
 318                         if (mei_cl_flow_ctrl_reduce(&dev->iamthif_cl))
 319                                 return -EIO;
 320                         dev->iamthif_flow_control_pending = true;
 321                         dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
 322                         dev_dbg(&dev->pdev->dev, "add amthif cb to write waiting list\n");
 323                         dev->iamthif_current_cb = cb;
 324                         dev->iamthif_file_object = cb->file_object;
 325                         list_add_tail(&cb->list, &dev->write_waiting_list.list);
 326                 } else {
 327                         dev_dbg(&dev->pdev->dev, "message does not complete, so add amthif cb to write list.\n");
 328                         list_add_tail(&cb->list, &dev->write_list.list);
 329                 }
 330         } else {
 331                 list_add_tail(&cb->list, &dev->write_list.list);
 332         }
 333         return 0;
 334 }
 335
 336 /**
 337  * mei_amthif_write - write amthif data to amthif client
 338  *
 339  * @dev: the device structure
 340  * @cb: mei call back struct
 341  *
 342  * returns 0 on success, <0 on failure.
 343  *
 344  */
 345 int mei_amthif_write(struct mei_device *dev, struct mei_cl_cb *cb)
 346 {
 347         int ret;
 348
 349         if (!dev || !cb)
 350                 return -ENODEV;
 351
 352         ret = mei_io_cb_alloc_resp_buf(cb, dev->iamthif_mtu);
 353         if (ret)
 354                 return ret;
 355
 356         cb->fop_type = MEI_FOP_WRITE;
 357
 358         if (!list_empty(&dev->amthif_cmd_list.list) ||
 359             dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 360                 dev_dbg(&dev->pdev->dev,
 361                         "amthif state = %d\n", dev->iamthif_state);
 362                 dev_dbg(&dev->pdev->dev, "AMTHIF: add cb to the wait list\n");
 363                 list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
 364                 return 0;
 365         }
 366         return mei_amthif_send_cmd(dev, cb);
 367 }
 368 /**
 369  * mei_amthif_run_next_cmd
 370  *
 371  * @dev: the device structure
 372  *
 373  * returns 0 on success, <0 on failure.
 374  */
 375 void mei_amthif_run_next_cmd(struct mei_device *dev)
 376 {
 377         struct mei_cl_cb *pos = NULL;
 378         struct mei_cl_cb *next = NULL;
 379         int status;
 380
 381         if (!dev)
 382                 return;
 383
 384         dev->iamthif_msg_buf_size = 0;
 385         dev->iamthif_msg_buf_index = 0;
 386         dev->iamthif_canceled = false;
 387         dev->iamthif_ioctl = true;
 388         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 389         dev->iamthif_timer = 0;
 390         dev->iamthif_file_object = NULL;
 391
 392         dev_dbg(&dev->pdev->dev, "complete amthif cmd_list cb.\n");
 393
 394         list_for_each_entry_safe(pos, next, &dev->amthif_cmd_list.list, list) {
 395                 list_del(&pos->list);
 396
 397                 if (pos->cl && pos->cl == &dev->iamthif_cl) {
 398                         status = mei_amthif_send_cmd(dev, pos);
 399                         if (status) {
 400                                 dev_dbg(&dev->pdev->dev,
 401                                         "amthif write failed status = %d\n",
 402                                                 status);
 403                                 return;
 404                         }
 405                         break;
 406                 }
 407         }
 408 }
 409
 410
 411 unsigned int mei_amthif_poll(struct mei_device *dev,
 412                 struct file *file, poll_table *wait)
 413 {
 414         unsigned int mask = 0;
 415
 416         poll_wait(file, &dev->iamthif_cl.wait, wait);
 417
 418         mutex_lock(&dev->device_lock);
 419         if (!mei_cl_is_connected(&dev->iamthif_cl)) {
 420
 421                 mask = POLLERR;
 422
 423         } else if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
 424                    dev->iamthif_file_object == file) {
 425
 426                 mask |= (POLLIN | POLLRDNORM);
 427                 dev_dbg(&dev->pdev->dev, "run next amthif cb\n");
 428                 mei_amthif_run_next_cmd(dev);
 429         }
 430         mutex_unlock(&dev->device_lock);
 431
 432         return mask;
 433 }
 434
 435
 436
 437 /**
 438  * mei_amthif_irq_write - write iamthif command in irq thread context.
 439  *
 440  * @dev: the device structure.
 441  * @cb_pos: callback block.
 442  * @cl: private data of the file object.
 443  * @cmpl_list: complete list.
 444  *
 445  * returns 0, OK; otherwise, error.
 446  */
 447 int mei_amthif_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 448                          struct mei_cl_cb *cmpl_list)
 449 {
 450         struct mei_device *dev = cl->dev;
 451         struct mei_msg_hdr mei_hdr;
 452         size_t len = dev->iamthif_msg_buf_size - dev->iamthif_msg_buf_index;
 453         u32 msg_slots = mei_data2slots(len);
 454         int slots;
 455         int rets;
 456
 457         rets = mei_cl_flow_ctrl_creds(cl);
 458         if (rets < 0)
 459                 return rets;
 460
 461         if (rets == 0) {
 462                 cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
 463                 return 0;
 464         }
 465
 466         mei_hdr.host_addr = cl->host_client_id;
 467         mei_hdr.me_addr = cl->me_client_id;
 468         mei_hdr.reserved = 0;
 469         mei_hdr.internal = 0;
 470
 471         slots = mei_hbuf_empty_slots(dev);
 472
 473         if (slots >= msg_slots) {
 474                 mei_hdr.length = len;
 475                 mei_hdr.msg_complete = 1;
 476         /* Split the message only if we can write the whole host buffer */
 477         } else if (slots == dev->hbuf_depth) {
 478                 msg_slots = slots;
 479                 len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
 480                 mei_hdr.length = len;
 481                 mei_hdr.msg_complete = 0;
 482         } else {
 483                 /* wait for next time the host buffer is empty */
 484                 return 0;
 485         }
 486
 487         dev_dbg(&dev->pdev->dev, MEI_HDR_FMT,  MEI_HDR_PRM(&mei_hdr));
 488
 489         rets = mei_write_message(dev, &mei_hdr,
 490                         dev->iamthif_msg_buf + dev->iamthif_msg_buf_index);
 491         if (rets) {
 492                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 493                 cl->status = rets;
 494                 list_del(&cb->list);
 495                 return rets;
 496         }
 497
 498         if (mei_cl_flow_ctrl_reduce(cl))
 499                 return -EIO;
 500
 501         dev->iamthif_msg_buf_index += mei_hdr.length;
 502         cl->status = 0;
 503
 504         if (mei_hdr.msg_complete) {
 505                 dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
 506                 dev->iamthif_flow_control_pending = true;
 507
 508                 /* save iamthif cb sent to amthif client */
 509                 cb->buf_idx = dev->iamthif_msg_buf_index;
 510                 dev->iamthif_current_cb = cb;
 511
 512                 list_move_tail(&cb->list, &dev->write_waiting_list.list);
 513         }
 514
 515
 516         return 0;
 517 }
 518
 519 /**
 520  * mei_amthif_irq_read_message - read routine after ISR to
 521  *                      handle the read amthif message
 522  *
 523  * @dev: the device structure
 524  * @mei_hdr: header of amthif message
 525  * @complete_list: An instance of our list structure
 526  *
 527  * returns 0 on success, <0 on failure.
 528  */
 529 int mei_amthif_irq_read_msg(struct mei_device *dev,
 530                             struct mei_msg_hdr *mei_hdr,
 531                             struct mei_cl_cb *complete_list)
 532 {
 533         struct mei_cl_cb *cb;
 534         unsigned char *buffer;
 535
 536         BUG_ON(mei_hdr->me_addr != dev->iamthif_cl.me_client_id);
 537         BUG_ON(dev->iamthif_state != MEI_IAMTHIF_READING);
 538
 539         buffer = dev->iamthif_msg_buf + dev->iamthif_msg_buf_index;
 540         BUG_ON(dev->iamthif_mtu < dev->iamthif_msg_buf_index + mei_hdr->length);
 541
 542         mei_read_slots(dev, buffer, mei_hdr->length);
 543
 544         dev->iamthif_msg_buf_index += mei_hdr->length;
 545
 546         if (!mei_hdr->msg_complete)
 547                 return 0;
 548
 549         dev_dbg(&dev->pdev->dev, "amthif_message_buffer_index =%d\n",
 550                         mei_hdr->length);
 551
 552         dev_dbg(&dev->pdev->dev, "completed amthif read.\n ");
 553         if (!dev->iamthif_current_cb)
 554                 return -ENODEV;
 555
 556         cb = dev->iamthif_current_cb;
 557         dev->iamthif_current_cb = NULL;
 558
 559         if (!cb->cl)
 560                 return -ENODEV;
 561
 562         dev->iamthif_stall_timer = 0;
 563         cb->buf_idx = dev->iamthif_msg_buf_index;
 564         cb->read_time = jiffies;
 565         if (dev->iamthif_ioctl && cb->cl == &dev->iamthif_cl) {
 566                 /* found the iamthif cb */
 567                 dev_dbg(&dev->pdev->dev, "complete the amthif read cb.\n ");
 568                 dev_dbg(&dev->pdev->dev, "add the amthif read cb to complete.\n ");
 569                 list_add_tail(&cb->list, &complete_list->list);
 570         }
 571         return 0;
 572 }
 573
 574 /**
 575  * mei_amthif_irq_read - prepares to read amthif data.
 576  *
 577  * @dev: the device structure.
 578  * @slots: free slots.
 579  *
 580  * returns 0, OK; otherwise, error.
 581  */
 582 int mei_amthif_irq_read(struct mei_device *dev, s32 *slots)
 583 {
 584         u32 msg_slots = mei_data2slots(sizeof(struct hbm_flow_control));
 585
 586         if (*slots < msg_slots)
 587                 return -EMSGSIZE;
 588
 589         *slots -= msg_slots;
 590
 591         if (mei_hbm_cl_flow_control_req(dev, &dev->iamthif_cl)) {
 592                 dev_dbg(&dev->pdev->dev, "iamthif flow control failed\n");
 593                 return -EIO;
 594         }
 595
 596         dev_dbg(&dev->pdev->dev, "iamthif flow control success\n");
 597         dev->iamthif_state = MEI_IAMTHIF_READING;
 598         dev->iamthif_flow_control_pending = false;
 599         dev->iamthif_msg_buf_index = 0;
 600         dev->iamthif_msg_buf_size = 0;
 601         dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
 602         dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
 603         return 0;
 604 }
 605
 606 /**
 607  * mei_amthif_complete - complete amthif callback.
 608  *
 609  * @dev: the device structure.
 610  * @cb_pos: callback block.
 611  */
 612 void mei_amthif_complete(struct mei_device *dev, struct mei_cl_cb *cb)
 613 {
 614         if (dev->iamthif_canceled != 1) {
 615                 dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
 616                 dev->iamthif_stall_timer = 0;
 617                 memcpy(cb->response_buffer.data,
 618                                 dev->iamthif_msg_buf,
 619                                 dev->iamthif_msg_buf_index);
 620                 list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
 621                 dev_dbg(&dev->pdev->dev, "amthif read completed\n");
 622                 dev->iamthif_timer = jiffies;
 623                 dev_dbg(&dev->pdev->dev, "dev->iamthif_timer = %ld\n",
 624                                 dev->iamthif_timer);
 625         } else {
 626                 mei_amthif_run_next_cmd(dev);
 627         }
 628
 629         dev_dbg(&dev->pdev->dev, "completing amthif call back.\n");
 630         wake_up_interruptible(&dev->iamthif_cl.wait);
 631 }
 632
 633 /**
 634  * mei_clear_list - removes all callbacks associated with file
 635  *              from mei_cb_list
 636  *
 637  * @dev: device structure.
 638  * @file: file structure
 639  * @mei_cb_list: callbacks list
 640  *
 641  * mei_clear_list is called to clear resources associated with file
 642  * when application calls close function or Ctrl-C was pressed
 643  *
 644  * returns true if callback removed from the list, false otherwise
 645  */
 646 static bool mei_clear_list(struct mei_device *dev,
 647                 const struct file *file, struct list_head *mei_cb_list)
 648 {
 649         struct mei_cl_cb *cb_pos = NULL;
 650         struct mei_cl_cb *cb_next = NULL;
 651         bool removed = false;
 652
 653         /* list all list member */
 654         list_for_each_entry_safe(cb_pos, cb_next, mei_cb_list, list) {
 655                 /* check if list member associated with a file */
 656                 if (file == cb_pos->file_object) {
 657                         /* remove member from the list */
 658                         list_del(&cb_pos->list);
 659                         /* check if cb equal to current iamthif cb */
 660                         if (dev->iamthif_current_cb == cb_pos) {
 661                                 dev->iamthif_current_cb = NULL;
 662                                 /* send flow control to iamthif client */
 663                                 mei_hbm_cl_flow_control_req(dev,
 664                                                         &dev->iamthif_cl);
 665                         }
 666                         /* free all allocated buffers */
 667                         mei_io_cb_free(cb_pos);
 668                         cb_pos = NULL;
 669                         removed = true;
 670                 }
 671         }
 672         return removed;
 673 }
 674
 675 /**
 676  * mei_clear_lists - removes all callbacks associated with file
 677  *
 678  * @dev: device structure
 679  * @file: file structure
 680  *
 681  * mei_clear_lists is called to clear resources associated with file
 682  * when application calls close function or Ctrl-C was pressed
 683  *
 684  * returns true if callback removed from the list, false otherwise
 685  */
 686 static bool mei_clear_lists(struct mei_device *dev, struct file *file)
 687 {
 688         bool removed = false;
 689
 690         /* remove callbacks associated with a file */
 691         mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
 692         if (mei_clear_list(dev, file, &dev->amthif_rd_complete_list.list))
 693                 removed = true;
 694
 695         mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
 696
 697         if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
 698                 removed = true;
 699
 700         if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
 701                 removed = true;
 702
 703         if (mei_clear_list(dev, file, &dev->write_list.list))
 704                 removed = true;
 705
 706         /* check if iamthif_current_cb not NULL */
 707         if (dev->iamthif_current_cb && !removed) {
 708                 /* check file and iamthif current cb association */
 709                 if (dev->iamthif_current_cb->file_object == file) {
 710                         /* remove cb */
 711                         mei_io_cb_free(dev->iamthif_current_cb);
 712                         dev->iamthif_current_cb = NULL;
 713                         removed = true;
 714                 }
 715         }
 716         return removed;
 717 }
 718
 719 /**
 720 * mei_amthif_release - the release function
 721 *
 722 *  @dev: device structure
 723 *  @file: pointer to file structure
 724 *
 725 *  returns 0 on success, <0 on error
 726 */
 727 int mei_amthif_release(struct mei_device *dev, struct file *file)
 728 {
 729         if (dev->iamthif_open_count > 0)
 730                 dev->iamthif_open_count--;
 731
 732         if (dev->iamthif_file_object == file &&
 733             dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 734
 735                 dev_dbg(&dev->pdev->dev, "amthif canceled iamthif state %d\n",
 736                     dev->iamthif_state);
 737                 dev->iamthif_canceled = true;
 738                 if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
 739                         dev_dbg(&dev->pdev->dev, "run next amthif iamthif cb\n");
 740                         mei_amthif_run_next_cmd(dev);
 741                 }
 742         }
 743
 744         if (mei_clear_lists(dev, file))
 745                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 746
 747         return 0;
 748 }