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 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, "amthif: failed to find the client\n");
  81                 return -ENOENT;
  82         }
  83
  84         cl->me_client_id = dev->me_clients[i].client_id;
  85
  86         /* Assign iamthif_mtu to the value received from ME  */
  87
  88         dev->iamthif_mtu = dev->me_clients[i].props.max_msg_length;
  89         dev_dbg(&dev->pdev->dev, "IAMTHIF_MTU = %d\n",
  90                         dev->me_clients[i].props.max_msg_length);
  91
  92         kfree(dev->iamthif_msg_buf);
  93         dev->iamthif_msg_buf = NULL;
  94
  95         /* allocate storage for ME message buffer */
  96         msg_buf = kcalloc(dev->iamthif_mtu,
  97                         sizeof(unsigned char), GFP_KERNEL);
  98         if (!msg_buf) {
  99                 dev_err(&dev->pdev->dev, "amthif: memory allocation for ME message buffer failed.\n");
 100                 return -ENOMEM;
 101         }
 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->pdev->dev, "amthif: failed link client\n");
 109                 return -ENOENT;
 110         }
 111
 112         cl->state = MEI_FILE_CONNECTING;
 113
 114         if (mei_hbm_cl_connect_req(dev, cl)) {
 115                 dev_dbg(&dev->pdev->dev, "amthif: Failed to connect to ME client\n");
 116                 cl->state = MEI_FILE_DISCONNECTED;
 117                 cl->host_client_id = 0;
 118         } else {
 119                 cl->timer_count = MEI_CONNECT_TIMEOUT;
 120         }
 121         return 0;
 122 }
 123
 124 /**
 125  * mei_amthif_find_read_list_entry - finds a amthilist entry for current file
 126  *
 127  * @dev: the device structure
 128  * @file: pointer to file object
 129  *
 130  * returns   returned a list entry on success, NULL on failure.
 131  */
 132 struct mei_cl_cb *mei_amthif_find_read_list_entry(struct mei_device *dev,
 133                                                 struct file *file)
 134 {
 135         struct mei_cl_cb *pos = NULL;
 136         struct mei_cl_cb *next = NULL;
 137
 138         list_for_each_entry_safe(pos, next,
 139                                 &dev->amthif_rd_complete_list.list, list) {
 140                 if (pos->cl && pos->cl == &dev->iamthif_cl &&
 141                         pos->file_object == file)
 142                         return pos;
 143         }
 144         return NULL;
 145 }
 146
 147
 148 /**
 149  * mei_amthif_read - read data from AMTHIF client
 150  *
 151  * @dev: the device structure
 152  * @if_num:  minor number
 153  * @file: pointer to file object
 154  * @*ubuf: pointer to user data in user space
 155  * @length: data length to read
 156  * @offset: data read offset
 157  *
 158  * Locking: called under "dev->device_lock" lock
 159  *
 160  * returns
 161  *  returned data length on success,
 162  *  zero if no data to read,
 163  *  negative on failure.
 164  */
 165 int mei_amthif_read(struct mei_device *dev, struct file *file,
 166                char __user *ubuf, size_t length, loff_t *offset)
 167 {
 168         int rets;
 169         int wait_ret;
 170         struct mei_cl_cb *cb = NULL;
 171         struct mei_cl *cl = file->private_data;
 172         unsigned long timeout;
 173         int i;
 174
 175         /* Only Posible if we are in timeout */
 176         if (!cl || cl != &dev->iamthif_cl) {
 177                 dev_dbg(&dev->pdev->dev, "bad file ext.\n");
 178                 return -ETIMEDOUT;
 179         }
 180
 181         i = mei_me_cl_by_id(dev, dev->iamthif_cl.me_client_id);
 182
 183         if (i < 0) {
 184                 dev_dbg(&dev->pdev->dev, "amthif client not found.\n");
 185                 return -ENODEV;
 186         }
 187         dev_dbg(&dev->pdev->dev, "checking amthif data\n");
 188         cb = mei_amthif_find_read_list_entry(dev, file);
 189
 190         /* Check for if we can block or not*/
 191         if (cb == NULL && file->f_flags & O_NONBLOCK)
 192                 return -EAGAIN;
 193
 194
 195         dev_dbg(&dev->pdev->dev, "waiting for amthif data\n");
 196         while (cb == NULL) {
 197                 /* unlock the Mutex */
 198                 mutex_unlock(&dev->device_lock);
 199
 200                 wait_ret = wait_event_interruptible(dev->iamthif_cl.wait,
 201                         (cb = mei_amthif_find_read_list_entry(dev, file)));
 202
 203                 /* Locking again the Mutex */
 204                 mutex_lock(&dev->device_lock);
 205
 206                 if (wait_ret)
 207                         return -ERESTARTSYS;
 208
 209                 dev_dbg(&dev->pdev->dev, "woke up from sleep\n");
 210         }
 211
 212
 213         dev_dbg(&dev->pdev->dev, "Got amthif data\n");
 214         dev->iamthif_timer = 0;
 215
 216         if (cb) {
 217                 timeout = cb->read_time +
 218                         mei_secs_to_jiffies(MEI_IAMTHIF_READ_TIMER);
 219                 dev_dbg(&dev->pdev->dev, "amthif timeout = %lud\n",
 220                                 timeout);
 221
 222                 if  (time_after(jiffies, timeout)) {
 223                         dev_dbg(&dev->pdev->dev, "amthif Time out\n");
 224                         /* 15 sec for the message has expired */
 225                         list_del(&cb->list);
 226                         rets = -ETIMEDOUT;
 227                         goto free;
 228                 }
 229         }
 230         /* if the whole message will fit remove it from the list */
 231         if (cb->buf_idx >= *offset && length >= (cb->buf_idx - *offset))
 232                 list_del(&cb->list);
 233         else if (cb->buf_idx > 0 && cb->buf_idx <= *offset) {
 234                 /* end of the message has been reached */
 235                 list_del(&cb->list);
 236                 rets = 0;
 237                 goto free;
 238         }
 239                 /* else means that not full buffer will be read and do not
 240                  * remove message from deletion list
 241                  */
 242
 243         dev_dbg(&dev->pdev->dev, "amthif cb->response_buffer size - %d\n",
 244             cb->response_buffer.size);
 245         dev_dbg(&dev->pdev->dev, "amthif cb->buf_idx - %lu\n", cb->buf_idx);
 246
 247         /* length is being turncated to PAGE_SIZE, however,
 248          * the buf_idx may point beyond */
 249         length = min_t(size_t, length, (cb->buf_idx - *offset));
 250
 251         if (copy_to_user(ubuf, cb->response_buffer.data + *offset, length))
 252                 rets = -EFAULT;
 253         else {
 254                 rets = length;
 255                 if ((*offset + length) < cb->buf_idx) {
 256                         *offset += length;
 257                         goto out;
 258                 }
 259         }
 260 free:
 261         dev_dbg(&dev->pdev->dev, "free amthif cb memory.\n");
 262         *offset = 0;
 263         mei_io_cb_free(cb);
 264 out:
 265         return rets;
 266 }
 267
 268 /**
 269  * mei_amthif_send_cmd - send amthif command to the ME
 270  *
 271  * @dev: the device structure
 272  * @cb: mei call back struct
 273  *
 274  * returns 0 on success, <0 on failure.
 275  *
 276  */
 277 static int mei_amthif_send_cmd(struct mei_device *dev, struct mei_cl_cb *cb)
 278 {
 279         struct mei_msg_hdr mei_hdr;
 280         int ret;
 281
 282         if (!dev || !cb)
 283                 return -ENODEV;
 284
 285         dev_dbg(&dev->pdev->dev, "write data to amthif client.\n");
 286
 287         dev->iamthif_state = MEI_IAMTHIF_WRITING;
 288         dev->iamthif_current_cb = cb;
 289         dev->iamthif_file_object = cb->file_object;
 290         dev->iamthif_canceled = false;
 291         dev->iamthif_ioctl = true;
 292         dev->iamthif_msg_buf_size = cb->request_buffer.size;
 293         memcpy(dev->iamthif_msg_buf, cb->request_buffer.data,
 294                cb->request_buffer.size);
 295
 296         ret = mei_cl_flow_ctrl_creds(&dev->iamthif_cl);
 297         if (ret < 0)
 298                 return ret;
 299
 300         if (ret && dev->mei_host_buffer_is_empty) {
 301                 ret = 0;
 302                 dev->mei_host_buffer_is_empty = false;
 303                 if (cb->request_buffer.size > mei_hbuf_max_data(dev)) {
 304                         mei_hdr.length = mei_hbuf_max_data(dev);
 305                         mei_hdr.msg_complete = 0;
 306                 } else {
 307                         mei_hdr.length = cb->request_buffer.size;
 308                         mei_hdr.msg_complete = 1;
 309                 }
 310
 311                 mei_hdr.host_addr = dev->iamthif_cl.host_client_id;
 312                 mei_hdr.me_addr = dev->iamthif_cl.me_client_id;
 313                 mei_hdr.reserved = 0;
 314                 dev->iamthif_msg_buf_index += mei_hdr.length;
 315                 if (mei_write_message(dev, &mei_hdr,
 316                                         (unsigned char *)dev->iamthif_msg_buf))
 317                         return -ENODEV;
 318
 319                 if (mei_hdr.msg_complete) {
 320                         if (mei_cl_flow_ctrl_reduce(&dev->iamthif_cl))
 321                                 return -ENODEV;
 322                         dev->iamthif_flow_control_pending = true;
 323                         dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
 324                         dev_dbg(&dev->pdev->dev, "add amthif cb to write waiting list\n");
 325                         dev->iamthif_current_cb = cb;
 326                         dev->iamthif_file_object = cb->file_object;
 327                         list_add_tail(&cb->list, &dev->write_waiting_list.list);
 328                 } else {
 329                         dev_dbg(&dev->pdev->dev, "message does not complete, so add amthif cb to write list.\n");
 330                         list_add_tail(&cb->list, &dev->write_list.list);
 331                 }
 332         } else {
 333                 if (!(dev->mei_host_buffer_is_empty))
 334                         dev_dbg(&dev->pdev->dev, "host buffer is not empty");
 335
 336                 dev_dbg(&dev->pdev->dev, "No flow control credentials, so add iamthif cb to write list.\n");
 337                 list_add_tail(&cb->list, &dev->write_list.list);
 338         }
 339         return 0;
 340 }
 341
 342 /**
 343  * mei_amthif_write - write amthif data to amthif client
 344  *
 345  * @dev: the device structure
 346  * @cb: mei call back struct
 347  *
 348  * returns 0 on success, <0 on failure.
 349  *
 350  */
 351 int mei_amthif_write(struct mei_device *dev, struct mei_cl_cb *cb)
 352 {
 353         int ret;
 354
 355         if (!dev || !cb)
 356                 return -ENODEV;
 357
 358         ret = mei_io_cb_alloc_resp_buf(cb, dev->iamthif_mtu);
 359         if (ret)
 360                 return ret;
 361
 362         cb->fop_type = MEI_FOP_IOCTL;
 363
 364         if (!list_empty(&dev->amthif_cmd_list.list) ||
 365             dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 366                 dev_dbg(&dev->pdev->dev,
 367                         "amthif state = %d\n", dev->iamthif_state);
 368                 dev_dbg(&dev->pdev->dev, "AMTHIF: add cb to the wait list\n");
 369                 list_add_tail(&cb->list, &dev->amthif_cmd_list.list);
 370                 return 0;
 371         }
 372         return mei_amthif_send_cmd(dev, cb);
 373 }
 374 /**
 375  * mei_amthif_run_next_cmd
 376  *
 377  * @dev: the device structure
 378  *
 379  * returns 0 on success, <0 on failure.
 380  */
 381 void mei_amthif_run_next_cmd(struct mei_device *dev)
 382 {
 383         struct mei_cl_cb *pos = NULL;
 384         struct mei_cl_cb *next = NULL;
 385         int status;
 386
 387         if (!dev)
 388                 return;
 389
 390         dev->iamthif_msg_buf_size = 0;
 391         dev->iamthif_msg_buf_index = 0;
 392         dev->iamthif_canceled = false;
 393         dev->iamthif_ioctl = true;
 394         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 395         dev->iamthif_timer = 0;
 396         dev->iamthif_file_object = NULL;
 397
 398         dev_dbg(&dev->pdev->dev, "complete amthif cmd_list cb.\n");
 399
 400         list_for_each_entry_safe(pos, next, &dev->amthif_cmd_list.list, list) {
 401                 list_del(&pos->list);
 402
 403                 if (pos->cl && pos->cl == &dev->iamthif_cl) {
 404                         status = mei_amthif_send_cmd(dev, pos);
 405                         if (status) {
 406                                 dev_dbg(&dev->pdev->dev,
 407                                         "amthif write failed status = %d\n",
 408                                                 status);
 409                                 return;
 410                         }
 411                         break;
 412                 }
 413         }
 414 }
 415
 416
 417 unsigned int mei_amthif_poll(struct mei_device *dev,
 418                 struct file *file, poll_table *wait)
 419 {
 420         unsigned int mask = 0;
 421         mutex_unlock(&dev->device_lock);
 422         poll_wait(file, &dev->iamthif_cl.wait, wait);
 423         mutex_lock(&dev->device_lock);
 424         if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE &&
 425                 dev->iamthif_file_object == file) {
 426                 mask |= (POLLIN | POLLRDNORM);
 427                 dev_dbg(&dev->pdev->dev, "run next amthif cb\n");
 428                 mei_amthif_run_next_cmd(dev);
 429         }
 430         return mask;
 431 }
 432
 433
 434
 435 /**
 436  * mei_amthif_irq_process_completed - processes completed iamthif operation.
 437  *
 438  * @dev: the device structure.
 439  * @slots: free slots.
 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_complete(struct mei_device *dev, s32 *slots,
 447                         struct mei_cl_cb *cb, struct mei_cl_cb *cmpl_list)
 448 {
 449         struct mei_msg_hdr mei_hdr;
 450         struct mei_cl *cl = cb->cl;
 451         size_t len = dev->iamthif_msg_buf_size - dev->iamthif_msg_buf_index;
 452         size_t msg_slots = mei_data2slots(len);
 453
 454         mei_hdr.host_addr = cl->host_client_id;
 455         mei_hdr.me_addr = cl->me_client_id;
 456         mei_hdr.reserved = 0;
 457
 458         if (*slots >= msg_slots) {
 459                 mei_hdr.length = len;
 460                 mei_hdr.msg_complete = 1;
 461         /* Split the message only if we can write the whole host buffer */
 462         } else if (*slots == dev->hbuf_depth) {
 463                 msg_slots = *slots;
 464                 len = (*slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
 465                 mei_hdr.length = len;
 466                 mei_hdr.msg_complete = 0;
 467         } else {
 468                 /* wait for next time the host buffer is empty */
 469                 return 0;
 470         }
 471
 472         dev_dbg(&dev->pdev->dev, MEI_HDR_FMT,  MEI_HDR_PRM(&mei_hdr));
 473
 474         *slots -=  msg_slots;
 475         if (mei_write_message(dev, &mei_hdr,
 476                 dev->iamthif_msg_buf + dev->iamthif_msg_buf_index)) {
 477                         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 478                         cl->status = -ENODEV;
 479                         list_del(&cb->list);
 480                         return -ENODEV;
 481         }
 482
 483         if (mei_cl_flow_ctrl_reduce(cl))
 484                 return -ENODEV;
 485
 486         dev->iamthif_msg_buf_index += mei_hdr.length;
 487         cl->status = 0;
 488
 489         if (mei_hdr.msg_complete) {
 490                 dev->iamthif_state = MEI_IAMTHIF_FLOW_CONTROL;
 491                 dev->iamthif_flow_control_pending = true;
 492
 493                 /* save iamthif cb sent to amthif client */
 494                 cb->buf_idx = dev->iamthif_msg_buf_index;
 495                 dev->iamthif_current_cb = cb;
 496
 497                 list_move_tail(&cb->list, &dev->write_waiting_list.list);
 498         }
 499
 500
 501         return 0;
 502 }
 503
 504 /**
 505  * mei_amthif_irq_read_message - read routine after ISR to
 506  *                      handle the read amthif message
 507  *
 508  * @complete_list: An instance of our list structure
 509  * @dev: the device structure
 510  * @mei_hdr: header of amthif message
 511  *
 512  * returns 0 on success, <0 on failure.
 513  */
 514 int mei_amthif_irq_read_message(struct mei_cl_cb *complete_list,
 515                 struct mei_device *dev, struct mei_msg_hdr *mei_hdr)
 516 {
 517         struct mei_cl_cb *cb;
 518         unsigned char *buffer;
 519
 520         BUG_ON(mei_hdr->me_addr != dev->iamthif_cl.me_client_id);
 521         BUG_ON(dev->iamthif_state != MEI_IAMTHIF_READING);
 522
 523         buffer = dev->iamthif_msg_buf + dev->iamthif_msg_buf_index;
 524         BUG_ON(dev->iamthif_mtu < dev->iamthif_msg_buf_index + mei_hdr->length);
 525
 526         mei_read_slots(dev, buffer, mei_hdr->length);
 527
 528         dev->iamthif_msg_buf_index += mei_hdr->length;
 529
 530         if (!mei_hdr->msg_complete)
 531                 return 0;
 532
 533         dev_dbg(&dev->pdev->dev,
 534                         "amthif_message_buffer_index =%d\n",
 535                         mei_hdr->length);
 536
 537         dev_dbg(&dev->pdev->dev, "completed amthif read.\n ");
 538         if (!dev->iamthif_current_cb)
 539                 return -ENODEV;
 540
 541         cb = dev->iamthif_current_cb;
 542         dev->iamthif_current_cb = NULL;
 543
 544         if (!cb->cl)
 545                 return -ENODEV;
 546
 547         dev->iamthif_stall_timer = 0;
 548         cb->buf_idx = dev->iamthif_msg_buf_index;
 549         cb->read_time = jiffies;
 550         if (dev->iamthif_ioctl && cb->cl == &dev->iamthif_cl) {
 551                 /* found the iamthif cb */
 552                 dev_dbg(&dev->pdev->dev, "complete the amthif read cb.\n ");
 553                 dev_dbg(&dev->pdev->dev, "add the amthif read cb to complete.\n ");
 554                 list_add_tail(&cb->list, &complete_list->list);
 555         }
 556         return 0;
 557 }
 558
 559 /**
 560  * mei_amthif_irq_read - prepares to read amthif data.
 561  *
 562  * @dev: the device structure.
 563  * @slots: free slots.
 564  *
 565  * returns 0, OK; otherwise, error.
 566  */
 567 int mei_amthif_irq_read(struct mei_device *dev, s32 *slots)
 568 {
 569
 570         if (((*slots) * sizeof(u32)) < (sizeof(struct mei_msg_hdr)
 571                         + sizeof(struct hbm_flow_control))) {
 572                 return -EMSGSIZE;
 573         }
 574         *slots -= mei_data2slots(sizeof(struct hbm_flow_control));
 575         if (mei_hbm_cl_flow_control_req(dev, &dev->iamthif_cl)) {
 576                 dev_dbg(&dev->pdev->dev, "iamthif flow control failed\n");
 577                 return -EIO;
 578         }
 579
 580         dev_dbg(&dev->pdev->dev, "iamthif flow control success\n");
 581         dev->iamthif_state = MEI_IAMTHIF_READING;
 582         dev->iamthif_flow_control_pending = false;
 583         dev->iamthif_msg_buf_index = 0;
 584         dev->iamthif_msg_buf_size = 0;
 585         dev->iamthif_stall_timer = MEI_IAMTHIF_STALL_TIMER;
 586         dev->mei_host_buffer_is_empty = mei_hbuf_is_empty(dev);
 587         return 0;
 588 }
 589
 590 /**
 591  * mei_amthif_complete - complete amthif callback.
 592  *
 593  * @dev: the device structure.
 594  * @cb_pos: callback block.
 595  */
 596 void mei_amthif_complete(struct mei_device *dev, struct mei_cl_cb *cb)
 597 {
 598         if (dev->iamthif_canceled != 1) {
 599                 dev->iamthif_state = MEI_IAMTHIF_READ_COMPLETE;
 600                 dev->iamthif_stall_timer = 0;
 601                 memcpy(cb->response_buffer.data,
 602                                 dev->iamthif_msg_buf,
 603                                 dev->iamthif_msg_buf_index);
 604                 list_add_tail(&cb->list, &dev->amthif_rd_complete_list.list);
 605                 dev_dbg(&dev->pdev->dev, "amthif read completed\n");
 606                 dev->iamthif_timer = jiffies;
 607                 dev_dbg(&dev->pdev->dev, "dev->iamthif_timer = %ld\n",
 608                                 dev->iamthif_timer);
 609         } else {
 610                 mei_amthif_run_next_cmd(dev);
 611         }
 612
 613         dev_dbg(&dev->pdev->dev, "completing amthif call back.\n");
 614         wake_up_interruptible(&dev->iamthif_cl.wait);
 615 }
 616
 617 /**
 618  * mei_clear_list - removes all callbacks associated with file
 619  *              from mei_cb_list
 620  *
 621  * @dev: device structure.
 622  * @file: file structure
 623  * @mei_cb_list: callbacks list
 624  *
 625  * mei_clear_list is called to clear resources associated with file
 626  * when application calls close function or Ctrl-C was pressed
 627  *
 628  * returns true if callback removed from the list, false otherwise
 629  */
 630 static bool mei_clear_list(struct mei_device *dev,
 631                 const struct file *file, struct list_head *mei_cb_list)
 632 {
 633         struct mei_cl_cb *cb_pos = NULL;
 634         struct mei_cl_cb *cb_next = NULL;
 635         bool removed = false;
 636
 637         /* list all list member */
 638         list_for_each_entry_safe(cb_pos, cb_next, mei_cb_list, list) {
 639                 /* check if list member associated with a file */
 640                 if (file == cb_pos->file_object) {
 641                         /* remove member from the list */
 642                         list_del(&cb_pos->list);
 643                         /* check if cb equal to current iamthif cb */
 644                         if (dev->iamthif_current_cb == cb_pos) {
 645                                 dev->iamthif_current_cb = NULL;
 646                                 /* send flow control to iamthif client */
 647                                 mei_hbm_cl_flow_control_req(dev,
 648                                                         &dev->iamthif_cl);
 649                         }
 650                         /* free all allocated buffers */
 651                         mei_io_cb_free(cb_pos);
 652                         cb_pos = NULL;
 653                         removed = true;
 654                 }
 655         }
 656         return removed;
 657 }
 658
 659 /**
 660  * mei_clear_lists - removes all callbacks associated with file
 661  *
 662  * @dev: device structure
 663  * @file: file structure
 664  *
 665  * mei_clear_lists is called to clear resources associated with file
 666  * when application calls close function or Ctrl-C was pressed
 667  *
 668  * returns true if callback removed from the list, false otherwise
 669  */
 670 static bool mei_clear_lists(struct mei_device *dev, struct file *file)
 671 {
 672         bool removed = false;
 673
 674         /* remove callbacks associated with a file */
 675         mei_clear_list(dev, file, &dev->amthif_cmd_list.list);
 676         if (mei_clear_list(dev, file, &dev->amthif_rd_complete_list.list))
 677                 removed = true;
 678
 679         mei_clear_list(dev, file, &dev->ctrl_rd_list.list);
 680
 681         if (mei_clear_list(dev, file, &dev->ctrl_wr_list.list))
 682                 removed = true;
 683
 684         if (mei_clear_list(dev, file, &dev->write_waiting_list.list))
 685                 removed = true;
 686
 687         if (mei_clear_list(dev, file, &dev->write_list.list))
 688                 removed = true;
 689
 690         /* check if iamthif_current_cb not NULL */
 691         if (dev->iamthif_current_cb && !removed) {
 692                 /* check file and iamthif current cb association */
 693                 if (dev->iamthif_current_cb->file_object == file) {
 694                         /* remove cb */
 695                         mei_io_cb_free(dev->iamthif_current_cb);
 696                         dev->iamthif_current_cb = NULL;
 697                         removed = true;
 698                 }
 699         }
 700         return removed;
 701 }
 702
 703 /**
 704 * mei_amthif_release - the release function
 705 *
 706 *  @inode: pointer to inode structure
 707 *  @file: pointer to file structure
 708 *
 709 *  returns 0 on success, <0 on error
 710 */
 711 int mei_amthif_release(struct mei_device *dev, struct file *file)
 712 {
 713         if (dev->open_handle_count > 0)
 714                 dev->open_handle_count--;
 715
 716         if (dev->iamthif_file_object == file &&
 717             dev->iamthif_state != MEI_IAMTHIF_IDLE) {
 718
 719                 dev_dbg(&dev->pdev->dev, "amthif canceled iamthif state %d\n",
 720                     dev->iamthif_state);
 721                 dev->iamthif_canceled = true;
 722                 if (dev->iamthif_state == MEI_IAMTHIF_READ_COMPLETE) {
 723                         dev_dbg(&dev->pdev->dev, "run next amthif iamthif cb\n");
 724                         mei_amthif_run_next_cmd(dev);
 725                 }
 726         }
 727
 728         if (mei_clear_lists(dev, file))
 729                 dev->iamthif_state = MEI_IAMTHIF_IDLE;
 730
 731         return 0;
 732 }