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         } else {
 251                 rets = length;
 252                 if ((*offset + length) < cb->buf_idx) {
 253                         *offset += length;
 254                         goto out;
 255                 }
 256         }
 257 free:
 258         dev_dbg(&dev->pdev->dev, "free amthif cb memory.\n");
 259         *offset = 0;
 260         mei_io_cb_free(cb);
 261 out:
 262         return rets;
 263 }
 264
 265 /**
 266  * mei_amthif_send_cmd - send amthif command to the ME
 267  *
 268  * @dev: the device structure
 269  * @cb: mei call back struct
 270  *
 271  * returns 0 on success, <0 on failure.
 272  *
 273  */
 274 static int mei_amthif_send_cmd(struct mei_device *dev, struct mei_cl_cb *cb)
 275 {
 276         struct mei_msg_hdr mei_hdr;
 277         int ret;
 278
 279         if (!dev || !cb)
 280                 return -ENODEV;
 281
 282         dev_dbg(&dev->pdev->dev, "write data to amthif client.\n");
 283
 284         dev->iamthif_state = MEI_IAMTHIF_WRITING;
 285         dev->iamthif_current_cb = cb;
 286         dev->iamthif_file_object = cb->file_object;
 287         dev->iamthif_canceled = false;
 288         dev->iamthif_ioctl = true;
 289         dev->iamthif_msg_buf_size = cb->request_buffer.size;
 290         memcpy(dev->iamthif_msg_buf, cb->request_buffer.data,
 291                cb->request_buffer.size);
 292
 293         ret = mei_cl_flow_ctrl_creds(&dev->iamthif_cl);
 294         if (ret < 0)
 295                 return ret;
 296
 297         if (ret && mei_hbuf_acquire(dev)) {
 298                 ret = 0;
 299                 if (cb->request_buffer.size > mei_hbuf_max_len(dev)) {
 300                         mei_hdr.length = mei_hbuf_max_len(dev);
 301                         mei_hdr.msg_complete = 0;
 302                 } else {
 303                         mei_hdr.length = cb->request_buffer.size;
 304                         mei_hdr.msg_complete = 1;
 305                 }
 306
 307                 mei_hdr.host_addr = dev->iamthif_cl.host_client_id;
 308                 mei_hdr.me_addr = dev->iamthif_cl.me_client_id;
 309                 mei_hdr.reserved = 0;
 310                 mei_hdr.internal = 0;
 311                 dev->iamthif_msg_buf_index += mei_hdr.length;
 312                 ret = mei_write_message(dev, &mei_hdr, dev->iamthif_msg_buf);
 313                 if (ret)
 314                         return ret;
 315
 316                 if (mei_hdr.msg_complete) {
 317                         if (mei_cl_flow_ctrl_reduce(&dev->iamthif_cl))
 318                                 return -EIO;
 319                         dev->iamthif_flow_control_pending = true;
 320                         dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
 321                         dev_dbg(&dev->pdev->dev, "add amthif cb to write waiting list\n");
 322                         dev->iamthif_current_cb = cb;
 323                         dev->iamthif_file_object = cb->file_object;
 324                         list_add_tail(&cb->list, &dev->write_waiting_list.list);
 325                 } else {
 326                         dev_dbg(&dev->pdev->dev, "message does not complete, so add amthif cb to write list.\n");
 327                         list_add_tail(&cb->list, &dev->write_list.list);
 328                 }
 329         } else {
 330                 list_add_tail(&cb->list, &dev->write_list.list);
 331         }
 332         return 0;
 333 }
 334
 335 /**
 336  * mei_amthif_write - write amthif data to amthif client
 337  *
 338  * @dev: the device structure
 339  * @cb: mei call back struct
 340  *
 341  * returns 0 on success, <0 on failure.
 342  *
 343  */
 344 int mei_amthif_write(struct mei_device *dev, struct mei_cl_cb *cb)
 345 {
 346         int ret;
 347
 348         if (!dev || !cb)
 349                 return -ENODEV;
 350
 351         ret = mei_io_cb_alloc_resp_buf(cb, dev->iamthif_mtu);
 352         if (ret)
 353                 return ret;
 354
 355         cb->fop_type = MEI_FOP_WRITE;
 356
 357         if (!list_empty(&dev->amthif_cmd_list.list) ||
 358             dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 359                 dev_dbg(&dev->pdev->dev,
 360                         "amthif state = %d\n", dev->iamthif_state);
 361                 dev_dbg(&dev->pdev->dev, "AMTHIF: add cb to the wait list\n");
 362                 list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
 363                 return 0;
 364         }
 365         return mei_amthif_send_cmd(dev, cb);
 366 }
 367 /**
 368  * mei_amthif_run_next_cmd
 369  *
 370  * @dev: the device structure
 371  *
 372  * returns 0 on success, <0 on failure.
 373  */
 374 void mei_amthif_run_next_cmd(struct mei_device *dev)
 375 {
 376         struct mei_cl_cb *pos = NULL;
 377         struct mei_cl_cb *next = NULL;
 378         int status;
 379
 380         if (!dev)
 381                 return;
 382
 383         dev->iamthif_msg_buf_size = 0;
 384         dev->iamthif_msg_buf_index = 0;
 385         dev->iamthif_canceled = false;
 386         dev->iamthif_ioctl = true;
 387         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 388         dev->iamthif_timer = 0;
 389         dev->iamthif_file_object = NULL;
 390
 391         dev_dbg(&dev->pdev->dev, "complete amthif cmd_list cb.\n");
 392
 393         list_for_each_entry_safe(pos, next, &dev->amthif_cmd_list.list, list) {
 394                 list_del(&pos->list);
 395
 396                 if (pos->cl && pos->cl == &dev->iamthif_cl) {
 397                         status = mei_amthif_send_cmd(dev, pos);
 398                         if (status) {
 399                                 dev_dbg(&dev->pdev->dev,
 400                                         "amthif write failed status = %d\n",
 401                                                 status);
 402                                 return;
 403                         }
 404                         break;
 405                 }
 406         }
 407 }
 408
 409
 410 unsigned int mei_amthif_poll(struct mei_device *dev,
 411                 struct file *file, poll_table *wait)
 412 {
 413         unsigned int mask = 0;
 414
 415         poll_wait(file, &dev->iamthif_cl.wait, wait);
 416
 417         mutex_lock(&dev->device_lock);
 418         if (!mei_cl_is_connected(&dev->iamthif_cl)) {
 419
 420                 mask = POLLERR;
 421
 422         } else if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
 423                    dev->iamthif_file_object == file) {
 424
 425                 mask |= (POLLIN | POLLRDNORM);
 426                 dev_dbg(&dev->pdev->dev, "run next amthif cb\n");
 427                 mei_amthif_run_next_cmd(dev);
 428         }
 429         mutex_unlock(&dev->device_lock);
 430
 431         return mask;
 432 }
 433
 434
 435
 436 /**
 437  * mei_amthif_irq_write - write iamthif command in irq thread context.
 438  *
 439  * @dev: the device structure.
 440  * @cb_pos: callback block.
 441  * @cl: private data of the file object.
 442  * @cmpl_list: complete list.
 443  *
 444  * returns 0, OK; otherwise, error.
 445  */
 446 int mei_amthif_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
 447                          struct mei_cl_cb *cmpl_list)
 448 {
 449         struct mei_device *dev = cl->dev;
 450         struct mei_msg_hdr mei_hdr;
 451         size_t len = dev->iamthif_msg_buf_size - dev->iamthif_msg_buf_index;
 452         u32 msg_slots = mei_data2slots(len);
 453         int slots;
 454         int rets;
 455
 456         rets = mei_cl_flow_ctrl_creds(cl);
 457         if (rets < 0)
 458                 return rets;
 459
 460         if (rets == 0) {
 461                 cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
 462                 return 0;
 463         }
 464
 465         mei_hdr.host_addr = cl->host_client_id;
 466         mei_hdr.me_addr = cl->me_client_id;
 467         mei_hdr.reserved = 0;
 468         mei_hdr.internal = 0;
 469
 470         slots = mei_hbuf_empty_slots(dev);
 471
 472         if (slots >= msg_slots) {
 473                 mei_hdr.length = len;
 474                 mei_hdr.msg_complete = 1;
 475         /* Split the message only if we can write the whole host buffer */
 476         } else if (slots == dev->hbuf_depth) {
 477                 msg_slots = slots;
 478                 len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
 479                 mei_hdr.length = len;
 480                 mei_hdr.msg_complete = 0;
 481         } else {
 482                 /* wait for next time the host buffer is empty */
 483                 return 0;
 484         }
 485
 486         dev_dbg(&dev->pdev->dev, MEI_HDR_FMT,  MEI_HDR_PRM(&mei_hdr));
 487
 488         rets = mei_write_message(dev, &mei_hdr,
 489                         dev->iamthif_msg_buf + dev->iamthif_msg_buf_index);
 490         if (rets) {
 491                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 492                 cl->status = rets;
 493                 list_del(&cb->list);
 494                 return rets;
 495         }
 496
 497         if (mei_cl_flow_ctrl_reduce(cl))
 498                 return -EIO;
 499
 500         dev->iamthif_msg_buf_index += mei_hdr.length;
 501         cl->status = 0;
 502
 503         if (mei_hdr.msg_complete) {
 504                 dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
 505                 dev->iamthif_flow_control_pending = true;
 506
 507                 /* save iamthif cb sent to amthif client */
 508                 cb->buf_idx = dev->iamthif_msg_buf_index;
 509                 dev->iamthif_current_cb = cb;
 510
 511                 list_move_tail(&cb->list, &dev->write_waiting_list.list);
 512         }
 513
 514
 515         return 0;
 516 }
 517
 518 /**
 519  * mei_amthif_irq_read_message - read routine after ISR to
 520  *                      handle the read amthif message
 521  *
 522  * @dev: the device structure
 523  * @mei_hdr: header of amthif message
 524  * @complete_list: An instance of our list structure
 525  *
 526  * returns 0 on success, <0 on failure.
 527  */
 528 int mei_amthif_irq_read_msg(struct mei_device *dev,
 529                             struct mei_msg_hdr *mei_hdr,
 530                             struct mei_cl_cb *complete_list)
 531 {
 532         struct mei_cl_cb *cb;
 533         unsigned char *buffer;
 534
 535         BUG_ON(mei_hdr->me_addr != dev->iamthif_cl.me_client_id);
 536         BUG_ON(dev->iamthif_state != MEI_IAMTHIF_READING);
 537
 538         buffer = dev->iamthif_msg_buf + dev->iamthif_msg_buf_index;
 539         BUG_ON(dev->iamthif_mtu < dev->iamthif_msg_buf_index + mei_hdr->length);
 540
 541         mei_read_slots(dev, buffer, mei_hdr->length);
 542
 543         dev->iamthif_msg_buf_index += mei_hdr->length;
 544
 545         if (!mei_hdr->msg_complete)
 546                 return 0;
 547
 548         dev_dbg(&dev->pdev->dev, "amthif_message_buffer_index =%d\n",
 549                         mei_hdr->length);
 550
 551         dev_dbg(&dev->pdev->dev, "completed amthif read.\n ");
 552         if (!dev->iamthif_current_cb)
 553                 return -ENODEV;
 554
 555         cb = dev->iamthif_current_cb;
 556         dev->iamthif_current_cb = NULL;
 557
 558         if (!cb->cl)
 559                 return -ENODEV;
 560
 561         dev->iamthif_stall_timer = 0;
 562         cb->buf_idx = dev->iamthif_msg_buf_index;
 563         cb->read_time = jiffies;
 564         if (dev->iamthif_ioctl && cb->cl == &dev->iamthif_cl) {
 565                 /* found the iamthif cb */
 566                 dev_dbg(&dev->pdev->dev, "complete the amthif read cb.\n ");
 567                 dev_dbg(&dev->pdev->dev, "add the amthif read cb to complete.\n ");
 568                 list_add_tail(&cb->list, &complete_list->list);
 569         }
 570         return 0;
 571 }
 572
 573 /**
 574  * mei_amthif_irq_read - prepares to read amthif data.
 575  *
 576  * @dev: the device structure.
 577  * @slots: free slots.
 578  *
 579  * returns 0, OK; otherwise, error.
 580  */
 581 int mei_amthif_irq_read(struct mei_device *dev, s32 *slots)
 582 {
 583         u32 msg_slots = mei_data2slots(sizeof(struct hbm_flow_control));
 584
 585         if (*slots < msg_slots)
 586                 return -EMSGSIZE;
 587
 588         *slots -= msg_slots;
 589
 590         if (mei_hbm_cl_flow_control_req(dev, &dev->iamthif_cl)) {
 591                 dev_dbg(&dev->pdev->dev, "iamthif flow control failed\n");
 592                 return -EIO;
 593         }
 594
 595         dev_dbg(&dev->pdev->dev, "iamthif flow control success\n");
 596         dev->iamthif_state = MEI_IAMTHIF_READING;
 597         dev->iamthif_flow_control_pending = false;
 598         dev->iamthif_msg_buf_index = 0;
 599         dev->iamthif_msg_buf_size = 0;
 600         dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
 601         dev->hbuf_is_ready = mei_hbuf_is_ready(dev);
 602         return 0;
 603 }
 604
 605 /**
 606  * mei_amthif_complete - complete amthif callback.
 607  *
 608  * @dev: the device structure.
 609  * @cb_pos: callback block.
 610  */
 611 void mei_amthif_complete(struct mei_device *dev, struct mei_cl_cb *cb)
 612 {
 613         if (dev->iamthif_canceled != 1) {
 614                 dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
 615                 dev->iamthif_stall_timer = 0;
 616                 memcpy(cb->response_buffer.data,
 617                                 dev->iamthif_msg_buf,
 618                                 dev->iamthif_msg_buf_index);
 619                 list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
 620                 dev_dbg(&dev->pdev->dev, "amthif read completed\n");
 621                 dev->iamthif_timer = jiffies;
 622                 dev_dbg(&dev->pdev->dev, "dev->iamthif_timer = %ld\n",
 623                                 dev->iamthif_timer);
 624         } else {
 625                 mei_amthif_run_next_cmd(dev);
 626         }
 627
 628         dev_dbg(&dev->pdev->dev, "completing amthif call back.\n");
 629         wake_up_interruptible(&dev->iamthif_cl.wait);
 630 }
 631
 632 /**
 633  * mei_clear_list - removes all callbacks associated with file
 634  *              from mei_cb_list
 635  *
 636  * @dev: device structure.
 637  * @file: file structure
 638  * @mei_cb_list: callbacks list
 639  *
 640  * mei_clear_list is called to clear resources associated with file
 641  * when application calls close function or Ctrl-C was pressed
 642  *
 643  * returns true if callback removed from the list, false otherwise
 644  */
 645 static bool mei_clear_list(struct mei_device *dev,
 646                 const struct file *file, struct list_head *mei_cb_list)
 647 {
 648         struct mei_cl_cb *cb_pos = NULL;
 649         struct mei_cl_cb *cb_next = NULL;
 650         bool removed = false;
 651
 652         /* list all list member */
 653         list_for_each_entry_safe(cb_pos, cb_next, mei_cb_list, list) {
 654                 /* check if list member associated with a file */
 655                 if (file == cb_pos->file_object) {
 656                         /* remove member from the list */
 657                         list_del(&cb_pos->list);
 658                         /* check if cb equal to current iamthif cb */
 659                         if (dev->iamthif_current_cb == cb_pos) {
 660                                 dev->iamthif_current_cb = NULL;
 661                                 /* send flow control to iamthif client */
 662                                 mei_hbm_cl_flow_control_req(dev,
 663                                                         &dev->iamthif_cl);
 664                         }
 665                         /* free all allocated buffers */
 666                         mei_io_cb_free(cb_pos);
 667                         cb_pos = NULL;
 668                         removed = true;
 669                 }
 670         }
 671         return removed;
 672 }
 673
 674 /**
 675  * mei_clear_lists - removes all callbacks associated with file
 676  *
 677  * @dev: device structure
 678  * @file: file structure
 679  *
 680  * mei_clear_lists is called to clear resources associated with file
 681  * when application calls close function or Ctrl-C was pressed
 682  *
 683  * returns true if callback removed from the list, false otherwise
 684  */
 685 static bool mei_clear_lists(struct mei_device *dev, struct file *file)
 686 {
 687         bool removed = false;
 688
 689         /* remove callbacks associated with a file */
 690         mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
 691         if (mei_clear_list(dev, file, &dev->amthif_rd_complete_list.list))
 692                 removed = true;
 693
 694         mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
 695
 696         if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
 697                 removed = true;
 698
 699         if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
 700                 removed = true;
 701
 702         if (mei_clear_list(dev, file, &dev->write_list.list))
 703                 removed = true;
 704
 705         /* check if iamthif_current_cb not NULL */
 706         if (dev->iamthif_current_cb && !removed) {
 707                 /* check file and iamthif current cb association */
 708                 if (dev->iamthif_current_cb->file_object == file) {
 709                         /* remove cb */
 710                         mei_io_cb_free(dev->iamthif_current_cb);
 711                         dev->iamthif_current_cb = NULL;
 712                         removed = true;
 713                 }
 714         }
 715         return removed;
 716 }
 717
 718 /**
 719 * mei_amthif_release - the release function
 720 *
 721 *  @dev: device structure
 722 *  @file: pointer to file structure
 723 *
 724 *  returns 0 on success, <0 on error
 725 */
 726 int mei_amthif_release(struct mei_device *dev, struct file *file)
 727 {
 728         if (dev->iamthif_open_count > 0)
 729                 dev->iamthif_open_count--;
 730
 731         if (dev->iamthif_file_object == file &&
 732             dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 733
 734                 dev_dbg(&dev->pdev->dev, "amthif canceled iamthif state %d\n",
 735                     dev->iamthif_state);
 736                 dev->iamthif_canceled = true;
 737                 if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
 738                         dev_dbg(&dev->pdev->dev, "run next amthif iamthif cb\n");
 739                         mei_amthif_run_next_cmd(dev);
 740                 }
 741         }
 742
 743         if (mei_clear_lists(dev, file))
 744                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 745
 746         return 0;
 747 }