drivers/misc/mei/client.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 <linux/mei.h>
  23
  24 #include "mei_dev.h"
  25 #include "hbm.h"
  26 #include "client.h"
  27
  28 /**
  29  * mei_me_cl_by_uuid - locate index of me client
  30  *
  31  * @dev: mei device
  32  * returns me client index or -ENOENT if not found
  33  */
  34 int mei_me_cl_by_uuid(const struct mei_device *dev, const uuid_le *uuid)
  35 {
  36         int i, res = -ENOENT;
  37
  38         for (i = 0; i < dev->me_clients_num; ++i)
  39                 if (uuid_le_cmp(*uuid,
  40                                 dev->me_clients[i].props.protocol_name) == 0) {
  41                         res = i;
  42                         break;
  43                 }
  44
  45         return res;
  46 }
  47
  48
  49 /**
  50  * mei_me_cl_by_id return index to me_clients for client_id
  51  *
  52  * @dev: the device structure
  53  * @client_id: me client id
  54  *
  55  * Locking: called under "dev->device_lock" lock
  56  *
  57  * returns index on success, -ENOENT on failure.
  58  */
  59
  60 int mei_me_cl_by_id(struct mei_device *dev, u8 client_id)
  61 {
  62         int i;
  63         for (i = 0; i < dev->me_clients_num; i++)
  64                 if (dev->me_clients[i].client_id == client_id)
  65                         break;
  66         if (WARN_ON(dev->me_clients[i].client_id != client_id))
  67                 return -ENOENT;
  68
  69         if (i == dev->me_clients_num)
  70                 return -ENOENT;
  71
  72         return i;
  73 }
  74
  75
  76 /**
  77  * mei_io_list_flush - removes list entry belonging to cl.
  78  *
  79  * @list:  An instance of our list structure
  80  * @cl: host client
  81  */
  82 void mei_io_list_flush(struct mei_cl_cb *list, struct mei_cl *cl)
  83 {
  84         struct mei_cl_cb *cb;
  85         struct mei_cl_cb *next;
  86
  87         list_for_each_entry_safe(cb, next, &list->list, list) {
  88                 if (cb->cl && mei_cl_cmp_id(cl, cb->cl))
  89                         list_del(&cb->list);
  90         }
  91 }
  92
  93 /**
  94  * mei_io_cb_free - free mei_cb_private related memory
  95  *
  96  * @cb: mei callback struct
  97  */
  98 void mei_io_cb_free(struct mei_cl_cb *cb)
  99 {
 100         if (cb == NULL)
 101                 return;
 102
 103         kfree(cb->request_buffer.data);
 104         kfree(cb->response_buffer.data);
 105         kfree(cb);
 106 }
 107
 108 /**
 109  * mei_io_cb_init - allocate and initialize io callback
 110  *
 111  * @cl - mei client
 112  * @fp: pointer to file structure
 113  *
 114  * returns mei_cl_cb pointer or NULL;
 115  */
 116 struct mei_cl_cb *mei_io_cb_init(struct mei_cl *cl, struct file *fp)
 117 {
 118         struct mei_cl_cb *cb;
 119
 120         cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
 121         if (!cb)
 122                 return NULL;
 123
 124         mei_io_list_init(cb);
 125
 126         cb->file_object = fp;
 127         cb->cl = cl;
 128         cb->buf_idx = 0;
 129         return cb;
 130 }
 131
 132 /**
 133  * mei_io_cb_alloc_req_buf - allocate request buffer
 134  *
 135  * @cb: io callback structure
 136  * @length: size of the buffer
 137  *
 138  * returns 0 on success
 139  *         -EINVAL if cb is NULL
 140  *         -ENOMEM if allocation failed
 141  */
 142 int mei_io_cb_alloc_req_buf(struct mei_cl_cb *cb, size_t length)
 143 {
 144         if (!cb)
 145                 return -EINVAL;
 146
 147         if (length == 0)
 148                 return 0;
 149
 150         cb->request_buffer.data = kmalloc(length, GFP_KERNEL);
 151         if (!cb->request_buffer.data)
 152                 return -ENOMEM;
 153         cb->request_buffer.size = length;
 154         return 0;
 155 }
 156 /**
 157  * mei_io_cb_alloc_resp_buf - allocate response buffer
 158  *
 159  * @cb: io callback structure
 160  * @length: size of the buffer
 161  *
 162  * returns 0 on success
 163  *         -EINVAL if cb is NULL
 164  *         -ENOMEM if allocation failed
 165  */
 166 int mei_io_cb_alloc_resp_buf(struct mei_cl_cb *cb, size_t length)
 167 {
 168         if (!cb)
 169                 return -EINVAL;
 170
 171         if (length == 0)
 172                 return 0;
 173
 174         cb->response_buffer.data = kmalloc(length, GFP_KERNEL);
 175         if (!cb->response_buffer.data)
 176                 return -ENOMEM;
 177         cb->response_buffer.size = length;
 178         return 0;
 179 }
 180
 181
 182
 183 /**
 184  * mei_cl_flush_queues - flushes queue lists belonging to cl.
 185  *
 186  * @cl: host client
 187  */
 188 int mei_cl_flush_queues(struct mei_cl *cl)
 189 {
 190         struct mei_device *dev;
 191
 192         if (WARN_ON(!cl || !cl->dev))
 193                 return -EINVAL;
 194
 195         dev = cl->dev;
 196
 197         cl_dbg(dev, cl, "remove list entry belonging to cl\n");
 198         mei_io_list_flush(&cl->dev->read_list, cl);
 199         mei_io_list_flush(&cl->dev->write_list, cl);
 200         mei_io_list_flush(&cl->dev->write_waiting_list, cl);
 201         mei_io_list_flush(&cl->dev->ctrl_wr_list, cl);
 202         mei_io_list_flush(&cl->dev->ctrl_rd_list, cl);
 203         mei_io_list_flush(&cl->dev->amthif_cmd_list, cl);
 204         mei_io_list_flush(&cl->dev->amthif_rd_complete_list, cl);
 205         return 0;
 206 }
 207
 208
 209 /**
 210  * mei_cl_init - initializes cl.
 211  *
 212  * @cl: host client to be initialized
 213  * @dev: mei device
 214  */
 215 void mei_cl_init(struct mei_cl *cl, struct mei_device *dev)
 216 {
 217         memset(cl, 0, sizeof(struct mei_cl));
 218         init_waitqueue_head(&cl->wait);
 219         init_waitqueue_head(&cl->rx_wait);
 220         init_waitqueue_head(&cl->tx_wait);
 221         INIT_LIST_HEAD(&cl->link);
 222         INIT_LIST_HEAD(&cl->device_link);
 223         cl->reading_state = MEI_IDLE;
 224         cl->writing_state = MEI_IDLE;
 225         cl->dev = dev;
 226 }
 227
 228 /**
 229  * mei_cl_allocate - allocates cl  structure and sets it up.
 230  *
 231  * @dev: mei device
 232  * returns  The allocated file or NULL on failure
 233  */
 234 struct mei_cl *mei_cl_allocate(struct mei_device *dev)
 235 {
 236         struct mei_cl *cl;
 237
 238         cl = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
 239         if (!cl)
 240                 return NULL;
 241
 242         mei_cl_init(cl, dev);
 243
 244         return cl;
 245 }
 246
 247 /**
 248  * mei_cl_find_read_cb - find this cl's callback in the read list
 249  *
 250  * @cl: host client
 251  *
 252  * returns cb on success, NULL on error
 253  */
 254 struct mei_cl_cb *mei_cl_find_read_cb(struct mei_cl *cl)
 255 {
 256         struct mei_device *dev = cl->dev;
 257         struct mei_cl_cb *cb = NULL;
 258         struct mei_cl_cb *next = NULL;
 259
 260         list_for_each_entry_safe(cb, next, &dev->read_list.list, list)
 261                 if (mei_cl_cmp_id(cl, cb->cl))
 262                         return cb;
 263         return NULL;
 264 }
 265
 266 /** mei_cl_link: allocate host id in the host map
 267  *
 268  * @cl - host client
 269  * @id - fixed host id or -1 for generic one
 270  *
 271  * returns 0 on success
 272  *      -EINVAL on incorrect values
 273  *      -ENONET if client not found
 274  */
 275 int mei_cl_link(struct mei_cl *cl, int id)
 276 {
 277         struct mei_device *dev;
 278         long open_handle_count;
 279
 280         if (WARN_ON(!cl || !cl->dev))
 281                 return -EINVAL;
 282
 283         dev = cl->dev;
 284
 285         /* If Id is not assigned get one*/
 286         if (id == MEI_HOST_CLIENT_ID_ANY)
 287                 id = find_first_zero_bit(dev->host_clients_map,
 288                                         MEI_CLIENTS_MAX);
 289
 290         if (id >= MEI_CLIENTS_MAX) {
 291                 dev_err(&dev->pdev->dev, "id exceeded %d", MEI_CLIENTS_MAX);
 292                 return -EMFILE;
 293         }
 294
 295         open_handle_count = dev->open_handle_count + dev->iamthif_open_count;
 296         if (open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
 297                 dev_err(&dev->pdev->dev, "open_handle_count exceeded %d",
 298                         MEI_MAX_OPEN_HANDLE_COUNT);
 299                 return -EMFILE;
 300         }
 301
 302         dev->open_handle_count++;
 303
 304         cl->host_client_id = id;
 305         list_add_tail(&cl->link, &dev->file_list);
 306
 307         set_bit(id, dev->host_clients_map);
 308
 309         cl->state = MEI_FILE_INITIALIZING;
 310
 311         cl_dbg(dev, cl, "link cl\n");
 312         return 0;
 313 }
 314
 315 /**
 316  * mei_cl_unlink - remove me_cl from the list
 317  *
 318  * @cl: host client
 319  */
 320 int mei_cl_unlink(struct mei_cl *cl)
 321 {
 322         struct mei_device *dev;
 323
 324         /* don't shout on error exit path */
 325         if (!cl)
 326                 return 0;
 327
 328         /* wd and amthif might not be initialized */
 329         if (!cl->dev)
 330                 return 0;
 331
 332         dev = cl->dev;
 333
 334         cl_dbg(dev, cl, "unlink client");
 335
 336         if (dev->open_handle_count > 0)
 337                 dev->open_handle_count--;
 338
 339         /* never clear the 0 bit */
 340         if (cl->host_client_id)
 341                 clear_bit(cl->host_client_id, dev->host_clients_map);
 342
 343         list_del_init(&cl->link);
 344
 345         cl->state = MEI_FILE_INITIALIZING;
 346
 347         return 0;
 348 }
 349
 350
 351 void mei_host_client_init(struct work_struct *work)
 352 {
 353         struct mei_device *dev = container_of(work,
 354                                               struct mei_device, init_work);
 355         struct mei_client_properties *client_props;
 356         int i;
 357
 358         mutex_lock(&dev->device_lock);
 359
 360         for (i = 0; i < dev->me_clients_num; i++) {
 361                 client_props = &dev->me_clients[i].props;
 362
 363                 if (!uuid_le_cmp(client_props->protocol_name, mei_amthif_guid))
 364                         mei_amthif_host_init(dev);
 365                 else if (!uuid_le_cmp(client_props->protocol_name, mei_wd_guid))
 366                         mei_wd_host_init(dev);
 367                 else if (!uuid_le_cmp(client_props->protocol_name, mei_nfc_guid))
 368                         mei_nfc_host_init(dev);
 369
 370         }
 371
 372         dev->dev_state = MEI_DEV_ENABLED;
 373         dev->reset_count = 0;
 374
 375         mutex_unlock(&dev->device_lock);
 376 }
 377
 378
 379 /**
 380  * mei_cl_disconnect - disconnect host client from the me one
 381  *
 382  * @cl: host client
 383  *
 384  * Locking: called under "dev->device_lock" lock
 385  *
 386  * returns 0 on success, <0 on failure.
 387  */
 388 int mei_cl_disconnect(struct mei_cl *cl)
 389 {
 390         struct mei_device *dev;
 391         struct mei_cl_cb *cb;
 392         int rets, err;
 393
 394         if (WARN_ON(!cl || !cl->dev))
 395                 return -ENODEV;
 396
 397         dev = cl->dev;
 398
 399         cl_dbg(dev, cl, "disconnecting");
 400
 401         if (cl->state != MEI_FILE_DISCONNECTING)
 402                 return 0;
 403
 404         cb = mei_io_cb_init(cl, NULL);
 405         if (!cb)
 406                 return -ENOMEM;
 407
 408         cb->fop_type = MEI_FOP_CLOSE;
 409         if (dev->hbuf_is_ready) {
 410                 dev->hbuf_is_ready = false;
 411                 if (mei_hbm_cl_disconnect_req(dev, cl)) {
 412                         rets = -ENODEV;
 413                         cl_err(dev, cl, "failed to disconnect.\n");
 414                         goto free;
 415                 }
 416                 mdelay(10); /* Wait for hardware disconnection ready */
 417                 list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
 418         } else {
 419                 cl_dbg(dev, cl, "add disconnect cb to control write list\n");
 420                 list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
 421
 422         }
 423         mutex_unlock(&dev->device_lock);
 424
 425         err = wait_event_timeout(dev->wait_recvd_msg,
 426                         MEI_FILE_DISCONNECTED == cl->state,
 427                         mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 428
 429         mutex_lock(&dev->device_lock);
 430         if (MEI_FILE_DISCONNECTED == cl->state) {
 431                 rets = 0;
 432                 cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
 433         } else {
 434                 rets = -ENODEV;
 435                 if (MEI_FILE_DISCONNECTED != cl->state)
 436                         cl_err(dev, cl, "wrong status client disconnect.\n");
 437
 438                 if (err)
 439                         cl_dbg(dev, cl, "wait failed disconnect err=%08x\n",
 440                                         err);
 441
 442                 cl_err(dev, cl, "failed to disconnect from FW client.\n");
 443         }
 444
 445         mei_io_list_flush(&dev->ctrl_rd_list, cl);
 446         mei_io_list_flush(&dev->ctrl_wr_list, cl);
 447 free:
 448         mei_io_cb_free(cb);
 449         return rets;
 450 }
 451
 452
 453 /**
 454  * mei_cl_is_other_connecting - checks if other
 455  *    client with the same me client id is connecting
 456  *
 457  * @cl: private data of the file object
 458  *
 459  * returns true if other client is connected, false - otherwise.
 460  */
 461 bool mei_cl_is_other_connecting(struct mei_cl *cl)
 462 {
 463         struct mei_device *dev;
 464         struct mei_cl *pos;
 465         struct mei_cl *next;
 466
 467         if (WARN_ON(!cl || !cl->dev))
 468                 return false;
 469
 470         dev = cl->dev;
 471
 472         list_for_each_entry_safe(pos, next, &dev->file_list, link) {
 473                 if ((pos->state == MEI_FILE_CONNECTING) &&
 474                     (pos != cl) && cl->me_client_id == pos->me_client_id)
 475                         return true;
 476
 477         }
 478
 479         return false;
 480 }
 481
 482 /**
 483  * mei_cl_connect - connect host client to the me one
 484  *
 485  * @cl: host client
 486  *
 487  * Locking: called under "dev->device_lock" lock
 488  *
 489  * returns 0 on success, <0 on failure.
 490  */
 491 int mei_cl_connect(struct mei_cl *cl, struct file *file)
 492 {
 493         struct mei_device *dev;
 494         struct mei_cl_cb *cb;
 495         int rets;
 496
 497         if (WARN_ON(!cl || !cl->dev))
 498                 return -ENODEV;
 499
 500         dev = cl->dev;
 501
 502         cb = mei_io_cb_init(cl, file);
 503         if (!cb) {
 504                 rets = -ENOMEM;
 505                 goto out;
 506         }
 507
 508         cb->fop_type = MEI_FOP_IOCTL;
 509
 510         if (dev->hbuf_is_ready && !mei_cl_is_other_connecting(cl)) {
 511                 dev->hbuf_is_ready = false;
 512
 513                 if (mei_hbm_cl_connect_req(dev, cl)) {
 514                         rets = -ENODEV;
 515                         goto out;
 516                 }
 517                 cl->timer_count = MEI_CONNECT_TIMEOUT;
 518                 list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
 519         } else {
 520                 list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
 521         }
 522
 523         mutex_unlock(&dev->device_lock);
 524         rets = wait_event_timeout(dev->wait_recvd_msg,
 525                                  (cl->state == MEI_FILE_CONNECTED ||
 526                                   cl->state == MEI_FILE_DISCONNECTED),
 527                                  mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 528         mutex_lock(&dev->device_lock);
 529
 530         if (cl->state != MEI_FILE_CONNECTED) {
 531                 rets = -EFAULT;
 532
 533                 mei_io_list_flush(&dev->ctrl_rd_list, cl);
 534                 mei_io_list_flush(&dev->ctrl_wr_list, cl);
 535                 goto out;
 536         }
 537
 538         rets = cl->status;
 539
 540 out:
 541         mei_io_cb_free(cb);
 542         return rets;
 543 }
 544
 545 /**
 546  * mei_cl_flow_ctrl_creds - checks flow_control credits for cl.
 547  *
 548  * @cl: private data of the file object
 549  *
 550  * returns 1 if mei_flow_ctrl_creds >0, 0 - otherwise.
 551  *      -ENOENT if mei_cl is not present
 552  *      -EINVAL if single_recv_buf == 0
 553  */
 554 int mei_cl_flow_ctrl_creds(struct mei_cl *cl)
 555 {
 556         struct mei_device *dev;
 557         int i;
 558
 559         if (WARN_ON(!cl || !cl->dev))
 560                 return -EINVAL;
 561
 562         dev = cl->dev;
 563
 564         if (!dev->me_clients_num)
 565                 return 0;
 566
 567         if (cl->mei_flow_ctrl_creds > 0)
 568                 return 1;
 569
 570         for (i = 0; i < dev->me_clients_num; i++) {
 571                 struct mei_me_client  *me_cl = &dev->me_clients[i];
 572                 if (me_cl->client_id == cl->me_client_id) {
 573                         if (me_cl->mei_flow_ctrl_creds) {
 574                                 if (WARN_ON(me_cl->props.single_recv_buf == 0))
 575                                         return -EINVAL;
 576                                 return 1;
 577                         } else {
 578                                 return 0;
 579                         }
 580                 }
 581         }
 582         return -ENOENT;
 583 }
 584
 585 /**
 586  * mei_cl_flow_ctrl_reduce - reduces flow_control.
 587  *
 588  * @cl: private data of the file object
 589  *
 590  * @returns
 591  *      0 on success
 592  *      -ENOENT when me client is not found
 593  *      -EINVAL when ctrl credits are <= 0
 594  */
 595 int mei_cl_flow_ctrl_reduce(struct mei_cl *cl)
 596 {
 597         struct mei_device *dev;
 598         int i;
 599
 600         if (WARN_ON(!cl || !cl->dev))
 601                 return -EINVAL;
 602
 603         dev = cl->dev;
 604
 605         if (!dev->me_clients_num)
 606                 return -ENOENT;
 607
 608         for (i = 0; i < dev->me_clients_num; i++) {
 609                 struct mei_me_client  *me_cl = &dev->me_clients[i];
 610                 if (me_cl->client_id == cl->me_client_id) {
 611                         if (me_cl->props.single_recv_buf != 0) {
 612                                 if (WARN_ON(me_cl->mei_flow_ctrl_creds <= 0))
 613                                         return -EINVAL;
 614                                 dev->me_clients[i].mei_flow_ctrl_creds--;
 615                         } else {
 616                                 if (WARN_ON(cl->mei_flow_ctrl_creds <= 0))
 617                                         return -EINVAL;
 618                                 cl->mei_flow_ctrl_creds--;
 619                         }
 620                         return 0;
 621                 }
 622         }
 623         return -ENOENT;
 624 }
 625
 626 /**
 627  * mei_cl_read_start - the start read client message function.
 628  *
 629  * @cl: host client
 630  *
 631  * returns 0 on success, <0 on failure.
 632  */
 633 int mei_cl_read_start(struct mei_cl *cl, size_t length)
 634 {
 635         struct mei_device *dev;
 636         struct mei_cl_cb *cb;
 637         int rets;
 638         int i;
 639
 640         if (WARN_ON(!cl || !cl->dev))
 641                 return -ENODEV;
 642
 643         dev = cl->dev;
 644
 645         if (!mei_cl_is_connected(cl))
 646                 return -ENODEV;
 647
 648         if (cl->read_cb) {
 649                 cl_dbg(dev, cl, "read is pending.\n");
 650                 return -EBUSY;
 651         }
 652         i = mei_me_cl_by_id(dev, cl->me_client_id);
 653         if (i < 0) {
 654                 cl_err(dev, cl, "no such me client %d\n", cl->me_client_id);
 655                 return  -ENODEV;
 656         }
 657
 658         cb = mei_io_cb_init(cl, NULL);
 659         if (!cb)
 660                 return -ENOMEM;
 661
 662         /* always allocate at least client max message */
 663         length = max_t(size_t, length, dev->me_clients[i].props.max_msg_length);
 664         rets = mei_io_cb_alloc_resp_buf(cb, length);
 665         if (rets)
 666                 goto err;
 667
 668         cb->fop_type = MEI_FOP_READ;
 669         cl->read_cb = cb;
 670         if (dev->hbuf_is_ready) {
 671                 dev->hbuf_is_ready = false;
 672                 if (mei_hbm_cl_flow_control_req(dev, cl)) {
 673                         cl_err(dev, cl, "flow control send failed\n");
 674                         rets = -ENODEV;
 675                         goto err;
 676                 }
 677                 list_add_tail(&cb->list, &dev->read_list.list);
 678         } else {
 679                 list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
 680         }
 681         return rets;
 682 err:
 683         mei_io_cb_free(cb);
 684         return rets;
 685 }
 686
 687 /**
 688  * mei_cl_irq_write_complete - write a message to device
 689  *      from the interrupt thread context
 690  *
 691  * @cl: client
 692  * @cb: callback block.
 693  * @slots: free slots.
 694  * @cmpl_list: complete list.
 695  *
 696  * returns 0, OK; otherwise error.
 697  */
 698 int mei_cl_irq_write_complete(struct mei_cl *cl, struct mei_cl_cb *cb,
 699                                      s32 *slots, struct mei_cl_cb *cmpl_list)
 700 {
 701         struct mei_device *dev;
 702         struct mei_msg_data *buf;
 703         struct mei_msg_hdr mei_hdr;
 704         size_t len;
 705         u32 msg_slots;
 706         int rets;
 707
 708
 709         if (WARN_ON(!cl || !cl->dev))
 710                 return -ENODEV;
 711
 712         dev = cl->dev;
 713
 714         buf = &cb->request_buffer;
 715
 716         rets = mei_cl_flow_ctrl_creds(cl);
 717         if (rets < 0)
 718                 return rets;
 719
 720         if (rets == 0) {
 721                 cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
 722                 return 0;
 723         }
 724
 725         len = buf->size - cb->buf_idx;
 726         msg_slots = mei_data2slots(len);
 727
 728         mei_hdr.host_addr = cl->host_client_id;
 729         mei_hdr.me_addr = cl->me_client_id;
 730         mei_hdr.reserved = 0;
 731         mei_hdr.internal = cb->internal;
 732
 733         if (*slots >= msg_slots) {
 734                 mei_hdr.length = len;
 735                 mei_hdr.msg_complete = 1;
 736         /* Split the message only if we can write the whole host buffer */
 737         } else if (*slots == dev->hbuf_depth) {
 738                 msg_slots = *slots;
 739                 len = (*slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
 740                 mei_hdr.length = len;
 741                 mei_hdr.msg_complete = 0;
 742         } else {
 743                 /* wait for next time the host buffer is empty */
 744                 return 0;
 745         }
 746
 747         cl_dbg(dev, cl, "buf: size = %d idx = %lu\n",
 748                         cb->request_buffer.size, cb->buf_idx);
 749
 750         *slots -=  msg_slots;
 751         rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
 752         if (rets) {
 753                 cl->status = rets;
 754                 list_move_tail(&cb->list, &cmpl_list->list);
 755                 return rets;
 756         }
 757
 758         cl->status = 0;
 759         cl->writing_state = MEI_WRITING;
 760         cb->buf_idx += mei_hdr.length;
 761
 762         if (mei_hdr.msg_complete) {
 763                 if (mei_cl_flow_ctrl_reduce(cl))
 764                         return -EIO;
 765                 list_move_tail(&cb->list, &dev->write_waiting_list.list);
 766         }
 767
 768         return 0;
 769 }
 770
 771 /**
 772  * mei_cl_write - submit a write cb to mei device
 773         assumes device_lock is locked
 774  *
 775  * @cl: host client
 776  * @cl: write callback with filled data
 777  *
 778  * returns number of bytes sent on success, <0 on failure.
 779  */
 780 int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
 781 {
 782         struct mei_device *dev;
 783         struct mei_msg_data *buf;
 784         struct mei_msg_hdr mei_hdr;
 785         int rets;
 786
 787
 788         if (WARN_ON(!cl || !cl->dev))
 789                 return -ENODEV;
 790
 791         if (WARN_ON(!cb))
 792                 return -EINVAL;
 793
 794         dev = cl->dev;
 795
 796
 797         buf = &cb->request_buffer;
 798
 799         cl_dbg(dev, cl, "mei_cl_write %d\n", buf->size);
 800
 801
 802         cb->fop_type = MEI_FOP_WRITE;
 803
 804         rets = mei_cl_flow_ctrl_creds(cl);
 805         if (rets < 0)
 806                 goto err;
 807
 808         /* Host buffer is not ready, we queue the request */
 809         if (rets == 0 || !dev->hbuf_is_ready) {
 810                 cb->buf_idx = 0;
 811                 /* unseting complete will enqueue the cb for write */
 812                 mei_hdr.msg_complete = 0;
 813                 rets = buf->size;
 814                 goto out;
 815         }
 816
 817         dev->hbuf_is_ready = false;
 818
 819         /* Check for a maximum length */
 820         if (buf->size > mei_hbuf_max_len(dev)) {
 821                 mei_hdr.length = mei_hbuf_max_len(dev);
 822                 mei_hdr.msg_complete = 0;
 823         } else {
 824                 mei_hdr.length = buf->size;
 825                 mei_hdr.msg_complete = 1;
 826         }
 827
 828         mei_hdr.host_addr = cl->host_client_id;
 829         mei_hdr.me_addr = cl->me_client_id;
 830         mei_hdr.reserved = 0;
 831         mei_hdr.internal = cb->internal;
 832
 833
 834         rets = mei_write_message(dev, &mei_hdr, buf->data);
 835         if (rets)
 836                 goto err;
 837
 838         cl->writing_state = MEI_WRITING;
 839         cb->buf_idx = mei_hdr.length;
 840
 841         rets = buf->size;
 842 out:
 843         if (mei_hdr.msg_complete) {
 844                 if (mei_cl_flow_ctrl_reduce(cl)) {
 845                         rets = -ENODEV;
 846                         goto err;
 847                 }
 848                 list_add_tail(&cb->list, &dev->write_waiting_list.list);
 849         } else {
 850                 list_add_tail(&cb->list, &dev->write_list.list);
 851         }
 852
 853
 854         if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
 855
 856                 mutex_unlock(&dev->device_lock);
 857                 if (wait_event_interruptible(cl->tx_wait,
 858                         cl->writing_state == MEI_WRITE_COMPLETE)) {
 859                                 if (signal_pending(current))
 860                                         rets = -EINTR;
 861                                 else
 862                                         rets = -ERESTARTSYS;
 863                 }
 864                 mutex_lock(&dev->device_lock);
 865         }
 866 err:
 867         return rets;
 868 }
 869
 870
 871 /**
 872  * mei_cl_complete - processes completed operation for a client
 873  *
 874  * @cl: private data of the file object.
 875  * @cb: callback block.
 876  */
 877 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
 878 {
 879         if (cb->fop_type == MEI_FOP_WRITE) {
 880                 mei_io_cb_free(cb);
 881                 cb = NULL;
 882                 cl->writing_state = MEI_WRITE_COMPLETE;
 883                 if (waitqueue_active(&cl->tx_wait))
 884                         wake_up_interruptible(&cl->tx_wait);
 885
 886         } else if (cb->fop_type == MEI_FOP_READ &&
 887                         MEI_READING == cl->reading_state) {
 888                 cl->reading_state = MEI_READ_COMPLETE;
 889                 if (waitqueue_active(&cl->rx_wait))
 890                         wake_up_interruptible(&cl->rx_wait);
 891                 else
 892                         mei_cl_bus_rx_event(cl);
 893
 894         }
 895 }
 896
 897
 898 /**
 899  * mei_cl_all_disconnect - disconnect forcefully all connected clients
 900  *
 901  * @dev - mei device
 902  */
 903
 904 void mei_cl_all_disconnect(struct mei_device *dev)
 905 {
 906         struct mei_cl *cl, *next;
 907
 908         list_for_each_entry_safe(cl, next, &dev->file_list, link) {
 909                 cl->state = MEI_FILE_DISCONNECTED;
 910                 cl->mei_flow_ctrl_creds = 0;
 911                 cl->read_cb = NULL;
 912                 cl->timer_count = 0;
 913         }
 914 }
 915
 916
 917 /**
 918  * mei_cl_all_wakeup  - wake up all readers and writers they can be interrupted
 919  *
 920  * @dev  - mei device
 921  */
 922 void mei_cl_all_wakeup(struct mei_device *dev)
 923 {
 924         struct mei_cl *cl, *next;
 925         list_for_each_entry_safe(cl, next, &dev->file_list, link) {
 926                 if (waitqueue_active(&cl->rx_wait)) {
 927                         cl_dbg(dev, cl, "Waking up reading client!\n");
 928                         wake_up_interruptible(&cl->rx_wait);
 929                 }
 930                 if (waitqueue_active(&cl->tx_wait)) {
 931                         cl_dbg(dev, cl, "Waking up writing client!\n");
 932                         wake_up_interruptible(&cl->tx_wait);
 933                 }
 934         }
 935 }
 936
 937 /**
 938  * mei_cl_all_write_clear - clear all pending writes
 939
 940  * @dev - mei device
 941  */
 942 void mei_cl_all_write_clear(struct mei_device *dev)
 943 {
 944         struct mei_cl_cb *cb, *next;
 945
 946         list_for_each_entry_safe(cb, next, &dev->write_list.list, list) {
 947                 list_del(&cb->list);
 948                 mei_io_cb_free(cb);
 949         }
 950 }
 951
 952