drivers/misc/mei/init.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/pci.h>
  18 #include <linux/sched.h>
  19 #include <linux/wait.h>
  20 #include <linux/delay.h>
  21
  22 #include "mei_dev.h"
  23 #include "hw.h"
  24 #include "interface.h"
  25 #include <linux/mei.h>
  26
  27 const char *mei_dev_state_str(int state)
  28 {
  29 #define MEI_DEV_STATE(state) case MEI_DEV_##state: return #state
  30         switch (state) {
  31         MEI_DEV_STATE(INITIALIZING);
  32         MEI_DEV_STATE(INIT_CLIENTS);
  33         MEI_DEV_STATE(ENABLED);
  34         MEI_DEV_STATE(RESETING);
  35         MEI_DEV_STATE(DISABLED);
  36         MEI_DEV_STATE(RECOVERING_FROM_RESET);
  37         MEI_DEV_STATE(POWER_DOWN);
  38         MEI_DEV_STATE(POWER_UP);
  39         default:
  40                 return "unkown";
  41         }
  42 #undef MEI_DEV_STATE
  43 }
  44
  45
  46
  47 /**
  48  * mei_io_list_flush - removes list entry belonging to cl.
  49  *
  50  * @list:  An instance of our list structure
  51  * @cl: private data of the file object
  52  */
  53 void mei_io_list_flush(struct mei_cl_cb *list, struct mei_cl *cl)
  54 {
  55         struct mei_cl_cb *pos;
  56         struct mei_cl_cb *next;
  57
  58         list_for_each_entry_safe(pos, next, &list->list, list) {
  59                 if (pos->cl) {
  60                         if (mei_cl_cmp_id(cl, pos->cl))
  61                                 list_del(&pos->list);
  62                 }
  63         }
  64 }
  65 /**
  66  * mei_cl_flush_queues - flushes queue lists belonging to cl.
  67  *
  68  * @dev: the device structure
  69  * @cl: private data of the file object
  70  */
  71 int mei_cl_flush_queues(struct mei_cl *cl)
  72 {
  73         if (!cl || !cl->dev)
  74                 return -EINVAL;
  75
  76         dev_dbg(&cl->dev->pdev->dev, "remove list entry belonging to cl\n");
  77         mei_io_list_flush(&cl->dev->read_list, cl);
  78         mei_io_list_flush(&cl->dev->write_list, cl);
  79         mei_io_list_flush(&cl->dev->write_waiting_list, cl);
  80         mei_io_list_flush(&cl->dev->ctrl_wr_list, cl);
  81         mei_io_list_flush(&cl->dev->ctrl_rd_list, cl);
  82         mei_io_list_flush(&cl->dev->amthif_cmd_list, cl);
  83         mei_io_list_flush(&cl->dev->amthif_rd_complete_list, cl);
  84         return 0;
  85 }
  86
  87
  88
  89 /**
  90  * init_mei_device - allocates and initializes the mei device structure
  91  *
  92  * @pdev: The pci device structure
  93  *
  94  * returns The mei_device_device pointer on success, NULL on failure.
  95  */
  96 struct mei_device *mei_device_init(struct pci_dev *pdev)
  97 {
  98         struct mei_device *dev;
  99
 100         dev = kzalloc(sizeof(struct mei_device), GFP_KERNEL);
 101         if (!dev)
 102                 return NULL;
 103
 104         /* setup our list array */
 105         INIT_LIST_HEAD(&dev->file_list);
 106         INIT_LIST_HEAD(&dev->wd_cl.link);
 107         INIT_LIST_HEAD(&dev->iamthif_cl.link);
 108         mutex_init(&dev->device_lock);
 109         init_waitqueue_head(&dev->wait_recvd_msg);
 110         init_waitqueue_head(&dev->wait_stop_wd);
 111         dev->dev_state = MEI_DEV_INITIALIZING;
 112         dev->iamthif_state = MEI_IAMTHIF_IDLE;
 113
 114         mei_io_list_init(&dev->read_list);
 115         mei_io_list_init(&dev->write_list);
 116         mei_io_list_init(&dev->write_waiting_list);
 117         mei_io_list_init(&dev->ctrl_wr_list);
 118         mei_io_list_init(&dev->ctrl_rd_list);
 119         mei_io_list_init(&dev->amthif_cmd_list);
 120         mei_io_list_init(&dev->amthif_rd_complete_list);
 121         dev->pdev = pdev;
 122         return dev;
 123 }
 124
 125 /**
 126  * mei_hw_init - initializes host and fw to start work.
 127  *
 128  * @dev: the device structure
 129  *
 130  * returns 0 on success, <0 on failure.
 131  */
 132 int mei_hw_init(struct mei_device *dev)
 133 {
 134         int err = 0;
 135         int ret;
 136
 137         mutex_lock(&dev->device_lock);
 138
 139         dev->host_hw_state = mei_hcsr_read(dev);
 140         dev->me_hw_state = mei_mecsr_read(dev);
 141         dev_dbg(&dev->pdev->dev, "host_hw_state = 0x%08x, mestate = 0x%08x.\n",
 142             dev->host_hw_state, dev->me_hw_state);
 143
 144         /* acknowledge interrupt and stop interupts */
 145         if ((dev->host_hw_state & H_IS) == H_IS)
 146                 mei_reg_write(dev, H_CSR, dev->host_hw_state);
 147
 148         /* Doesn't change in runtime */
 149         dev->hbuf_depth = (dev->host_hw_state & H_CBD) >> 24;
 150
 151         dev->recvd_msg = false;
 152         dev_dbg(&dev->pdev->dev, "reset in start the mei device.\n");
 153
 154         mei_reset(dev, 1);
 155
 156         dev_dbg(&dev->pdev->dev, "host_hw_state = 0x%08x, me_hw_state = 0x%08x.\n",
 157             dev->host_hw_state, dev->me_hw_state);
 158
 159         /* wait for ME to turn on ME_RDY */
 160         if (!dev->recvd_msg) {
 161                 mutex_unlock(&dev->device_lock);
 162                 err = wait_event_interruptible_timeout(dev->wait_recvd_msg,
 163                         dev->recvd_msg,
 164                         mei_secs_to_jiffies(MEI_INTEROP_TIMEOUT));
 165                 mutex_lock(&dev->device_lock);
 166         }
 167
 168         if (err <= 0 && !dev->recvd_msg) {
 169                 dev->dev_state = MEI_DEV_DISABLED;
 170                 dev_dbg(&dev->pdev->dev,
 171                         "wait_event_interruptible_timeout failed"
 172                         "on wait for ME to turn on ME_RDY.\n");
 173                 ret = -ENODEV;
 174                 goto out;
 175         }
 176
 177         if (!(((dev->host_hw_state & H_RDY) == H_RDY) &&
 178               ((dev->me_hw_state & ME_RDY_HRA) == ME_RDY_HRA))) {
 179                 dev->dev_state = MEI_DEV_DISABLED;
 180                 dev_dbg(&dev->pdev->dev,
 181                         "host_hw_state = 0x%08x, me_hw_state = 0x%08x.\n",
 182                         dev->host_hw_state, dev->me_hw_state);
 183
 184                 if (!(dev->host_hw_state & H_RDY))
 185                         dev_dbg(&dev->pdev->dev, "host turn off H_RDY.\n");
 186
 187                 if (!(dev->me_hw_state & ME_RDY_HRA))
 188                         dev_dbg(&dev->pdev->dev, "ME turn off ME_RDY.\n");
 189
 190                 dev_err(&dev->pdev->dev, "link layer initialization failed.\n");
 191                 ret = -ENODEV;
 192                 goto out;
 193         }
 194
 195         if (dev->version.major_version != HBM_MAJOR_VERSION ||
 196             dev->version.minor_version != HBM_MINOR_VERSION) {
 197                 dev_dbg(&dev->pdev->dev, "MEI start failed.\n");
 198                 ret = -ENODEV;
 199                 goto out;
 200         }
 201
 202         dev->recvd_msg = false;
 203         dev_dbg(&dev->pdev->dev, "host_hw_state = 0x%08x, me_hw_state = 0x%08x.\n",
 204             dev->host_hw_state, dev->me_hw_state);
 205         dev_dbg(&dev->pdev->dev, "ME turn on ME_RDY and host turn on H_RDY.\n");
 206         dev_dbg(&dev->pdev->dev, "link layer has been established.\n");
 207         dev_dbg(&dev->pdev->dev, "MEI  start success.\n");
 208         ret = 0;
 209
 210 out:
 211         mutex_unlock(&dev->device_lock);
 212         return ret;
 213 }
 214
 215 /**
 216  * mei_hw_reset - resets fw via mei csr register.
 217  *
 218  * @dev: the device structure
 219  * @interrupts_enabled: if interrupt should be enabled after reset.
 220  */
 221 static void mei_hw_reset(struct mei_device *dev, int interrupts_enabled)
 222 {
 223         dev->host_hw_state |= (H_RST | H_IG);
 224
 225         if (interrupts_enabled)
 226                 mei_enable_interrupts(dev);
 227         else
 228                 mei_disable_interrupts(dev);
 229 }
 230
 231 /**
 232  * mei_reset - resets host and fw.
 233  *
 234  * @dev: the device structure
 235  * @interrupts_enabled: if interrupt should be enabled after reset.
 236  */
 237 void mei_reset(struct mei_device *dev, int interrupts_enabled)
 238 {
 239         struct mei_cl *cl_pos = NULL;
 240         struct mei_cl *cl_next = NULL;
 241         struct mei_cl_cb *cb_pos = NULL;
 242         struct mei_cl_cb *cb_next = NULL;
 243         bool unexpected;
 244
 245         if (dev->dev_state == MEI_DEV_RECOVERING_FROM_RESET) {
 246                 dev->need_reset = true;
 247                 return;
 248         }
 249
 250         unexpected = (dev->dev_state != MEI_DEV_INITIALIZING &&
 251                         dev->dev_state != MEI_DEV_DISABLED &&
 252                         dev->dev_state != MEI_DEV_POWER_DOWN &&
 253                         dev->dev_state != MEI_DEV_POWER_UP);
 254
 255         dev->host_hw_state = mei_hcsr_read(dev);
 256
 257         dev_dbg(&dev->pdev->dev, "before reset host_hw_state = 0x%08x.\n",
 258             dev->host_hw_state);
 259
 260         mei_hw_reset(dev, interrupts_enabled);
 261
 262         dev->host_hw_state &= ~H_RST;
 263         dev->host_hw_state |= H_IG;
 264
 265         mei_hcsr_set(dev);
 266
 267         dev_dbg(&dev->pdev->dev, "currently saved host_hw_state = 0x%08x.\n",
 268             dev->host_hw_state);
 269
 270         dev->need_reset = false;
 271
 272         if (dev->dev_state != MEI_DEV_INITIALIZING) {
 273                 if (dev->dev_state != MEI_DEV_DISABLED &&
 274                     dev->dev_state != MEI_DEV_POWER_DOWN)
 275                         dev->dev_state = MEI_DEV_RESETING;
 276
 277                 list_for_each_entry_safe(cl_pos,
 278                                 cl_next, &dev->file_list, link) {
 279                         cl_pos->state = MEI_FILE_DISCONNECTED;
 280                         cl_pos->mei_flow_ctrl_creds = 0;
 281                         cl_pos->read_cb = NULL;
 282                         cl_pos->timer_count = 0;
 283                 }
 284                 /* remove entry if already in list */
 285                 dev_dbg(&dev->pdev->dev, "remove iamthif and wd from the file list.\n");
 286                 mei_me_cl_unlink(dev, &dev->wd_cl);
 287
 288                 mei_me_cl_unlink(dev, &dev->iamthif_cl);
 289
 290                 mei_amthif_reset_params(dev);
 291                 memset(&dev->wr_ext_msg, 0, sizeof(dev->wr_ext_msg));
 292         }
 293
 294         dev->me_clients_num = 0;
 295         dev->rd_msg_hdr = 0;
 296         dev->wd_pending = false;
 297
 298         /* update the state of the registers after reset */
 299         dev->host_hw_state = mei_hcsr_read(dev);
 300         dev->me_hw_state = mei_mecsr_read(dev);
 301
 302         dev_dbg(&dev->pdev->dev, "after reset host_hw_state = 0x%08x, me_hw_state = 0x%08x.\n",
 303             dev->host_hw_state, dev->me_hw_state);
 304
 305         if (unexpected)
 306                 dev_warn(&dev->pdev->dev, "unexpected reset: dev_state = %s\n",
 307                          mei_dev_state_str(dev->dev_state));
 308
 309         /* Wake up all readings so they can be interrupted */
 310         list_for_each_entry_safe(cl_pos, cl_next, &dev->file_list, link) {
 311                 if (waitqueue_active(&cl_pos->rx_wait)) {
 312                         dev_dbg(&dev->pdev->dev, "Waking up client!\n");
 313                         wake_up_interruptible(&cl_pos->rx_wait);
 314                 }
 315         }
 316         /* remove all waiting requests */
 317         list_for_each_entry_safe(cb_pos, cb_next, &dev->write_list.list, list) {
 318                 list_del(&cb_pos->list);
 319                 mei_io_cb_free(cb_pos);
 320         }
 321 }
 322
 323
 324
 325 /**
 326  * host_start_message - mei host sends start message.
 327  *
 328  * @dev: the device structure
 329  *
 330  * returns none.
 331  */
 332 void mei_host_start_message(struct mei_device *dev)
 333 {
 334         struct mei_msg_hdr *mei_hdr;
 335         struct hbm_host_version_request *start_req;
 336         const size_t len = sizeof(struct hbm_host_version_request);
 337
 338         mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);
 339
 340         /* host start message */
 341         start_req = (struct hbm_host_version_request *)&dev->wr_msg_buf[1];
 342         memset(start_req, 0, len);
 343         start_req->hbm_cmd = HOST_START_REQ_CMD;
 344         start_req->host_version.major_version = HBM_MAJOR_VERSION;
 345         start_req->host_version.minor_version = HBM_MINOR_VERSION;
 346
 347         dev->recvd_msg = false;
 348         if (mei_write_message(dev, mei_hdr, (unsigned char *)start_req, len)) {
 349                 dev_dbg(&dev->pdev->dev, "write send version message to FW fail.\n");
 350                 dev->dev_state = MEI_DEV_RESETING;
 351                 mei_reset(dev, 1);
 352         }
 353         dev->init_clients_state = MEI_START_MESSAGE;
 354         dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
 355         return ;
 356 }
 357
 358 /**
 359  * host_enum_clients_message - host sends enumeration client request message.
 360  *
 361  * @dev: the device structure
 362  *
 363  * returns none.
 364  */
 365 void mei_host_enum_clients_message(struct mei_device *dev)
 366 {
 367         struct mei_msg_hdr *mei_hdr;
 368         struct hbm_host_enum_request *enum_req;
 369         const size_t len = sizeof(struct hbm_host_enum_request);
 370         /* enumerate clients */
 371         mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);
 372
 373         enum_req = (struct hbm_host_enum_request *) &dev->wr_msg_buf[1];
 374         memset(enum_req, 0, sizeof(struct hbm_host_enum_request));
 375         enum_req->hbm_cmd = HOST_ENUM_REQ_CMD;
 376
 377         if (mei_write_message(dev, mei_hdr, (unsigned char *)enum_req, len)) {
 378                 dev->dev_state = MEI_DEV_RESETING;
 379                 dev_dbg(&dev->pdev->dev, "write send enumeration request message to FW fail.\n");
 380                 mei_reset(dev, 1);
 381         }
 382         dev->init_clients_state = MEI_ENUM_CLIENTS_MESSAGE;
 383         dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
 384         return;
 385 }
 386
 387
 388 /**
 389  * allocate_me_clients_storage - allocates storage for me clients
 390  *
 391  * @dev: the device structure
 392  *
 393  * returns none.
 394  */
 395 void mei_allocate_me_clients_storage(struct mei_device *dev)
 396 {
 397         struct mei_me_client *clients;
 398         int b;
 399
 400         /* count how many ME clients we have */
 401         for_each_set_bit(b, dev->me_clients_map, MEI_CLIENTS_MAX)
 402                 dev->me_clients_num++;
 403
 404         if (dev->me_clients_num <= 0)
 405                 return ;
 406
 407
 408         if (dev->me_clients != NULL) {
 409                 kfree(dev->me_clients);
 410                 dev->me_clients = NULL;
 411         }
 412         dev_dbg(&dev->pdev->dev, "memory allocation for ME clients size=%zd.\n",
 413                 dev->me_clients_num * sizeof(struct mei_me_client));
 414         /* allocate storage for ME clients representation */
 415         clients = kcalloc(dev->me_clients_num,
 416                         sizeof(struct mei_me_client), GFP_KERNEL);
 417         if (!clients) {
 418                 dev_dbg(&dev->pdev->dev, "memory allocation for ME clients failed.\n");
 419                 dev->dev_state = MEI_DEV_RESETING;
 420                 mei_reset(dev, 1);
 421                 return ;
 422         }
 423         dev->me_clients = clients;
 424         return ;
 425 }
 426
 427 void mei_host_client_init(struct work_struct *work)
 428 {
 429         struct mei_device *dev = container_of(work,
 430                                               struct mei_device, init_work);
 431         struct mei_client_properties *client_props;
 432         int i;
 433
 434         mutex_lock(&dev->device_lock);
 435
 436         bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
 437         dev->open_handle_count = 0;
 438
 439         /*
 440          * Reserving the first three client IDs
 441          * 0: Reserved for MEI Bus Message communications
 442          * 1: Reserved for Watchdog
 443          * 2: Reserved for AMTHI
 444          */
 445         bitmap_set(dev->host_clients_map, 0, 3);
 446
 447         for (i = 0; i < dev->me_clients_num; i++) {
 448                 client_props = &dev->me_clients[i].props;
 449
 450                 if (!uuid_le_cmp(client_props->protocol_name, mei_amthi_guid))
 451                         mei_amthif_host_init(dev);
 452                 else if (!uuid_le_cmp(client_props->protocol_name, mei_wd_guid))
 453                         mei_wd_host_init(dev);
 454         }
 455
 456         dev->dev_state = MEI_DEV_ENABLED;
 457
 458         mutex_unlock(&dev->device_lock);
 459 }
 460
 461 int mei_host_client_enumerate(struct mei_device *dev)
 462 {
 463
 464         struct mei_msg_hdr *mei_hdr;
 465         struct hbm_props_request *prop_req;
 466         const size_t len = sizeof(struct hbm_props_request);
 467         unsigned long next_client_index;
 468         u8 client_num;
 469
 470
 471         client_num = dev->me_client_presentation_num;
 472
 473         next_client_index = find_next_bit(dev->me_clients_map, MEI_CLIENTS_MAX,
 474                                           dev->me_client_index);
 475
 476         /* We got all client properties */
 477         if (next_client_index == MEI_CLIENTS_MAX) {
 478                 schedule_work(&dev->init_work);
 479
 480                 return 0;
 481         }
 482
 483         dev->me_clients[client_num].client_id = next_client_index;
 484         dev->me_clients[client_num].mei_flow_ctrl_creds = 0;
 485
 486         mei_hdr = mei_hbm_hdr(&dev->wr_msg_buf[0], len);
 487         prop_req = (struct hbm_props_request *)&dev->wr_msg_buf[1];
 488
 489         memset(prop_req, 0, sizeof(struct hbm_props_request));
 490
 491
 492         prop_req->hbm_cmd = HOST_CLIENT_PROPERTIES_REQ_CMD;
 493         prop_req->address = next_client_index;
 494
 495         if (mei_write_message(dev, mei_hdr, (unsigned char *) prop_req,
 496                               mei_hdr->length)) {
 497                 dev->dev_state = MEI_DEV_RESETING;
 498                 dev_err(&dev->pdev->dev, "Properties request command failed\n");
 499                 mei_reset(dev, 1);
 500
 501                 return -EIO;
 502         }
 503
 504         dev->init_clients_timer = MEI_CLIENTS_INIT_TIMEOUT;
 505         dev->me_client_index = next_client_index;
 506
 507         return 0;
 508 }
 509
 510 /**
 511  * mei_init_file_private - initializes private file structure.
 512  *
 513  * @priv: private file structure to be initialized
 514  * @file: the file structure
 515  */
 516 void mei_cl_init(struct mei_cl *priv, struct mei_device *dev)
 517 {
 518         memset(priv, 0, sizeof(struct mei_cl));
 519         init_waitqueue_head(&priv->wait);
 520         init_waitqueue_head(&priv->rx_wait);
 521         init_waitqueue_head(&priv->tx_wait);
 522         INIT_LIST_HEAD(&priv->link);
 523         priv->reading_state = MEI_IDLE;
 524         priv->writing_state = MEI_IDLE;
 525         priv->dev = dev;
 526 }
 527
 528 int mei_me_cl_by_uuid(const struct mei_device *dev, const uuid_le *cuuid)
 529 {
 530         int i, res = -ENOENT;
 531
 532         for (i = 0; i < dev->me_clients_num; ++i)
 533                 if (uuid_le_cmp(*cuuid,
 534                                 dev->me_clients[i].props.protocol_name) == 0) {
 535                         res = i;
 536                         break;
 537                 }
 538
 539         return res;
 540 }
 541
 542
 543 /**
 544  * mei_me_cl_link - create link between host and me clinet and add
 545  *   me_cl to the list
 546  *
 547  * @dev: the device structure
 548  * @cl: link between me and host client assocated with opened file descriptor
 549  * @cuuid: uuid of ME client
 550  * @client_id: id of the host client
 551  *
 552  * returns ME client index if ME client
 553  *      -EINVAL on incorrect values
 554  *      -ENONET if client not found
 555  */
 556 int mei_me_cl_link(struct mei_device *dev, struct mei_cl *cl,
 557                         const uuid_le *cuuid, u8 host_cl_id)
 558 {
 559         int i;
 560
 561         if (!dev || !cl || !cuuid)
 562                 return -EINVAL;
 563
 564         /* check for valid client id */
 565         i = mei_me_cl_by_uuid(dev, cuuid);
 566         if (i >= 0) {
 567                 cl->me_client_id = dev->me_clients[i].client_id;
 568                 cl->state = MEI_FILE_CONNECTING;
 569                 cl->host_client_id = host_cl_id;
 570
 571                 list_add_tail(&cl->link, &dev->file_list);
 572                 return (u8)i;
 573         }
 574
 575         return -ENOENT;
 576 }
 577 /**
 578  * mei_me_cl_unlink - remove me_cl from the list
 579  *
 580  * @dev: the device structure
 581  * @host_client_id: host client id to be removed
 582  */
 583 void mei_me_cl_unlink(struct mei_device *dev, struct mei_cl *cl)
 584 {
 585         struct mei_cl *pos, *next;
 586         list_for_each_entry_safe(pos, next, &dev->file_list, link) {
 587                 if (cl->host_client_id == pos->host_client_id) {
 588                         dev_dbg(&dev->pdev->dev, "remove host client = %d, ME client = %d\n",
 589                                         pos->host_client_id, pos->me_client_id);
 590                         list_del_init(&pos->link);
 591                         break;
 592                 }
 593         }
 594 }
 595
 596 /**
 597  * mei_alloc_file_private - allocates a private file structure and sets it up.
 598  * @file: the file structure
 599  *
 600  * returns  The allocated file or NULL on failure
 601  */
 602 struct mei_cl *mei_cl_allocate(struct mei_device *dev)
 603 {
 604         struct mei_cl *cl;
 605
 606         cl = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
 607         if (!cl)
 608                 return NULL;
 609
 610         mei_cl_init(cl, dev);
 611
 612         return cl;
 613 }
 614
 615
 616
 617 /**
 618  * mei_disconnect_host_client - sends disconnect message to fw from host client.
 619  *
 620  * @dev: the device structure
 621  * @cl: private data of the file object
 622  *
 623  * Locking: called under "dev->device_lock" lock
 624  *
 625  * returns 0 on success, <0 on failure.
 626  */
 627 int mei_disconnect_host_client(struct mei_device *dev, struct mei_cl *cl)
 628 {
 629         struct mei_cl_cb *cb;
 630         int rets, err;
 631
 632         if (!dev || !cl)
 633                 return -ENODEV;
 634
 635         if (cl->state != MEI_FILE_DISCONNECTING)
 636                 return 0;
 637
 638         cb = mei_io_cb_init(cl, NULL);
 639         if (!cb)
 640                 return -ENOMEM;
 641
 642         cb->fop_type = MEI_FOP_CLOSE;
 643         if (dev->mei_host_buffer_is_empty) {
 644                 dev->mei_host_buffer_is_empty = false;
 645                 if (mei_disconnect(dev, cl)) {
 646                         rets = -ENODEV;
 647                         dev_dbg(&dev->pdev->dev, "failed to call mei_disconnect.\n");
 648                         goto free;
 649                 }
 650                 mdelay(10); /* Wait for hardware disconnection ready */
 651                 list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
 652         } else {
 653                 dev_dbg(&dev->pdev->dev, "add disconnect cb to control write list\n");
 654                 list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
 655
 656         }
 657         mutex_unlock(&dev->device_lock);
 658
 659         err = wait_event_timeout(dev->wait_recvd_msg,
 660                         MEI_FILE_DISCONNECTED == cl->state,
 661                         mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 662
 663         mutex_lock(&dev->device_lock);
 664         if (MEI_FILE_DISCONNECTED == cl->state) {
 665                 rets = 0;
 666                 dev_dbg(&dev->pdev->dev, "successfully disconnected from FW client.\n");
 667         } else {
 668                 rets = -ENODEV;
 669                 if (MEI_FILE_DISCONNECTED != cl->state)
 670                         dev_dbg(&dev->pdev->dev, "wrong status client disconnect.\n");
 671
 672                 if (err)
 673                         dev_dbg(&dev->pdev->dev,
 674                                         "wait failed disconnect err=%08x\n",
 675                                         err);
 676
 677                 dev_dbg(&dev->pdev->dev, "failed to disconnect from FW client.\n");
 678         }
 679
 680         mei_io_list_flush(&dev->ctrl_rd_list, cl);
 681         mei_io_list_flush(&dev->ctrl_wr_list, cl);
 682 free:
 683         mei_io_cb_free(cb);
 684         return rets;
 685 }
 686