drivers/misc/mei/client.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (c) 2003-2019, Intel Corporation. All rights reserved.
   4  * Intel Management Engine Interface (Intel MEI) Linux driver
   5  */
   6
   7 #include <linux/sched/signal.h>
   8 #include <linux/wait.h>
   9 #include <linux/delay.h>
  10 #include <linux/slab.h>
  11 #include <linux/pm_runtime.h>
  12
  13 #include <linux/mei.h>
  14
  15 #include "mei_dev.h"
  16 #include "hbm.h"
  17 #include "client.h"
  18
  19 /**
  20  * mei_me_cl_init - initialize me client
  21  *
  22  * @me_cl: me client
  23  */
  24 void mei_me_cl_init(struct mei_me_client *me_cl)
  25 {
  26         INIT_LIST_HEAD(&me_cl->list);
  27         kref_init(&me_cl->refcnt);
  28 }
  29
  30 /**
  31  * mei_me_cl_get - increases me client refcount
  32  *
  33  * @me_cl: me client
  34  *
  35  * Locking: called under "dev->device_lock" lock
  36  *
  37  * Return: me client or NULL
  38  */
  39 struct mei_me_client *mei_me_cl_get(struct mei_me_client *me_cl)
  40 {
  41         if (me_cl && kref_get_unless_zero(&me_cl->refcnt))
  42                 return me_cl;
  43
  44         return NULL;
  45 }
  46
  47 /**
  48  * mei_me_cl_release - free me client
  49  *
  50  * Locking: called under "dev->device_lock" lock
  51  *
  52  * @ref: me_client refcount
  53  */
  54 static void mei_me_cl_release(struct kref *ref)
  55 {
  56         struct mei_me_client *me_cl =
  57                 container_of(ref, struct mei_me_client, refcnt);
  58
  59         kfree(me_cl);
  60 }
  61
  62 /**
  63  * mei_me_cl_put - decrease me client refcount and free client if necessary
  64  *
  65  * Locking: called under "dev->device_lock" lock
  66  *
  67  * @me_cl: me client
  68  */
  69 void mei_me_cl_put(struct mei_me_client *me_cl)
  70 {
  71         if (me_cl)
  72                 kref_put(&me_cl->refcnt, mei_me_cl_release);
  73 }
  74
  75 /**
  76  * __mei_me_cl_del  - delete me client from the list and decrease
  77  *     reference counter
  78  *
  79  * @dev: mei device
  80  * @me_cl: me client
  81  *
  82  * Locking: dev->me_clients_rwsem
  83  */
  84 static void __mei_me_cl_del(struct mei_device *dev, struct mei_me_client *me_cl)
  85 {
  86         if (!me_cl)
  87                 return;
  88
  89         list_del_init(&me_cl->list);
  90         mei_me_cl_put(me_cl);
  91 }
  92
  93 /**
  94  * mei_me_cl_del - delete me client from the list and decrease
  95  *     reference counter
  96  *
  97  * @dev: mei device
  98  * @me_cl: me client
  99  */
 100 void mei_me_cl_del(struct mei_device *dev, struct mei_me_client *me_cl)
 101 {
 102         down_write(&dev->me_clients_rwsem);
 103         __mei_me_cl_del(dev, me_cl);
 104         up_write(&dev->me_clients_rwsem);
 105 }
 106
 107 /**
 108  * mei_me_cl_add - add me client to the list
 109  *
 110  * @dev: mei device
 111  * @me_cl: me client
 112  */
 113 void mei_me_cl_add(struct mei_device *dev, struct mei_me_client *me_cl)
 114 {
 115         down_write(&dev->me_clients_rwsem);
 116         list_add(&me_cl->list, &dev->me_clients);
 117         up_write(&dev->me_clients_rwsem);
 118 }
 119
 120 /**
 121  * __mei_me_cl_by_uuid - locate me client by uuid
 122  *      increases ref count
 123  *
 124  * @dev: mei device
 125  * @uuid: me client uuid
 126  *
 127  * Return: me client or NULL if not found
 128  *
 129  * Locking: dev->me_clients_rwsem
 130  */
 131 static struct mei_me_client *__mei_me_cl_by_uuid(struct mei_device *dev,
 132                                         const uuid_le *uuid)
 133 {
 134         struct mei_me_client *me_cl;
 135         const uuid_le *pn;
 136
 137         WARN_ON(!rwsem_is_locked(&dev->me_clients_rwsem));
 138
 139         list_for_each_entry(me_cl, &dev->me_clients, list) {
 140                 pn = &me_cl->props.protocol_name;
 141                 if (uuid_le_cmp(*uuid, *pn) == 0)
 142                         return mei_me_cl_get(me_cl);
 143         }
 144
 145         return NULL;
 146 }
 147
 148 /**
 149  * mei_me_cl_by_uuid - locate me client by uuid
 150  *      increases ref count
 151  *
 152  * @dev: mei device
 153  * @uuid: me client uuid
 154  *
 155  * Return: me client or NULL if not found
 156  *
 157  * Locking: dev->me_clients_rwsem
 158  */
 159 struct mei_me_client *mei_me_cl_by_uuid(struct mei_device *dev,
 160                                         const uuid_le *uuid)
 161 {
 162         struct mei_me_client *me_cl;
 163
 164         down_read(&dev->me_clients_rwsem);
 165         me_cl = __mei_me_cl_by_uuid(dev, uuid);
 166         up_read(&dev->me_clients_rwsem);
 167
 168         return me_cl;
 169 }
 170
 171 /**
 172  * mei_me_cl_by_id - locate me client by client id
 173  *      increases ref count
 174  *
 175  * @dev: the device structure
 176  * @client_id: me client id
 177  *
 178  * Return: me client or NULL if not found
 179  *
 180  * Locking: dev->me_clients_rwsem
 181  */
 182 struct mei_me_client *mei_me_cl_by_id(struct mei_device *dev, u8 client_id)
 183 {
 184
 185         struct mei_me_client *__me_cl, *me_cl = NULL;
 186
 187         down_read(&dev->me_clients_rwsem);
 188         list_for_each_entry(__me_cl, &dev->me_clients, list) {
 189                 if (__me_cl->client_id == client_id) {
 190                         me_cl = mei_me_cl_get(__me_cl);
 191                         break;
 192                 }
 193         }
 194         up_read(&dev->me_clients_rwsem);
 195
 196         return me_cl;
 197 }
 198
 199 /**
 200  * __mei_me_cl_by_uuid_id - locate me client by client id and uuid
 201  *      increases ref count
 202  *
 203  * @dev: the device structure
 204  * @uuid: me client uuid
 205  * @client_id: me client id
 206  *
 207  * Return: me client or null if not found
 208  *
 209  * Locking: dev->me_clients_rwsem
 210  */
 211 static struct mei_me_client *__mei_me_cl_by_uuid_id(struct mei_device *dev,
 212                                            const uuid_le *uuid, u8 client_id)
 213 {
 214         struct mei_me_client *me_cl;
 215         const uuid_le *pn;
 216
 217         WARN_ON(!rwsem_is_locked(&dev->me_clients_rwsem));
 218
 219         list_for_each_entry(me_cl, &dev->me_clients, list) {
 220                 pn = &me_cl->props.protocol_name;
 221                 if (uuid_le_cmp(*uuid, *pn) == 0 &&
 222                     me_cl->client_id == client_id)
 223                         return mei_me_cl_get(me_cl);
 224         }
 225
 226         return NULL;
 227 }
 228
 229
 230 /**
 231  * mei_me_cl_by_uuid_id - locate me client by client id and uuid
 232  *      increases ref count
 233  *
 234  * @dev: the device structure
 235  * @uuid: me client uuid
 236  * @client_id: me client id
 237  *
 238  * Return: me client or null if not found
 239  */
 240 struct mei_me_client *mei_me_cl_by_uuid_id(struct mei_device *dev,
 241                                            const uuid_le *uuid, u8 client_id)
 242 {
 243         struct mei_me_client *me_cl;
 244
 245         down_read(&dev->me_clients_rwsem);
 246         me_cl = __mei_me_cl_by_uuid_id(dev, uuid, client_id);
 247         up_read(&dev->me_clients_rwsem);
 248
 249         return me_cl;
 250 }
 251
 252 /**
 253  * mei_me_cl_rm_by_uuid - remove all me clients matching uuid
 254  *
 255  * @dev: the device structure
 256  * @uuid: me client uuid
 257  *
 258  * Locking: called under "dev->device_lock" lock
 259  */
 260 void mei_me_cl_rm_by_uuid(struct mei_device *dev, const uuid_le *uuid)
 261 {
 262         struct mei_me_client *me_cl;
 263
 264         dev_dbg(dev->dev, "remove %pUl\n", uuid);
 265
 266         down_write(&dev->me_clients_rwsem);
 267         me_cl = __mei_me_cl_by_uuid(dev, uuid);
 268         __mei_me_cl_del(dev, me_cl);
 269         mei_me_cl_put(me_cl);
 270         up_write(&dev->me_clients_rwsem);
 271 }
 272
 273 /**
 274  * mei_me_cl_rm_by_uuid_id - remove all me clients matching client id
 275  *
 276  * @dev: the device structure
 277  * @uuid: me client uuid
 278  * @id: me client id
 279  *
 280  * Locking: called under "dev->device_lock" lock
 281  */
 282 void mei_me_cl_rm_by_uuid_id(struct mei_device *dev, const uuid_le *uuid, u8 id)
 283 {
 284         struct mei_me_client *me_cl;
 285
 286         dev_dbg(dev->dev, "remove %pUl %d\n", uuid, id);
 287
 288         down_write(&dev->me_clients_rwsem);
 289         me_cl = __mei_me_cl_by_uuid_id(dev, uuid, id);
 290         __mei_me_cl_del(dev, me_cl);
 291         mei_me_cl_put(me_cl);
 292         up_write(&dev->me_clients_rwsem);
 293 }
 294
 295 /**
 296  * mei_me_cl_rm_all - remove all me clients
 297  *
 298  * @dev: the device structure
 299  *
 300  * Locking: called under "dev->device_lock" lock
 301  */
 302 void mei_me_cl_rm_all(struct mei_device *dev)
 303 {
 304         struct mei_me_client *me_cl, *next;
 305
 306         down_write(&dev->me_clients_rwsem);
 307         list_for_each_entry_safe(me_cl, next, &dev->me_clients, list)
 308                 __mei_me_cl_del(dev, me_cl);
 309         up_write(&dev->me_clients_rwsem);
 310 }
 311
 312 /**
 313  * mei_io_cb_free - free mei_cb_private related memory
 314  *
 315  * @cb: mei callback struct
 316  */
 317 void mei_io_cb_free(struct mei_cl_cb *cb)
 318 {
 319         if (cb == NULL)
 320                 return;
 321
 322         list_del(&cb->list);
 323         kfree(cb->buf.data);
 324         kfree(cb);
 325 }
 326
 327 /**
 328  * mei_tx_cb_queue - queue tx callback
 329  *
 330  * Locking: called under "dev->device_lock" lock
 331  *
 332  * @cb: mei callback struct
 333  * @head: an instance of list to queue on
 334  */
 335 static inline void mei_tx_cb_enqueue(struct mei_cl_cb *cb,
 336                                      struct list_head *head)
 337 {
 338         list_add_tail(&cb->list, head);
 339         cb->cl->tx_cb_queued++;
 340 }
 341
 342 /**
 343  * mei_tx_cb_dequeue - dequeue tx callback
 344  *
 345  * Locking: called under "dev->device_lock" lock
 346  *
 347  * @cb: mei callback struct to dequeue and free
 348  */
 349 static inline void mei_tx_cb_dequeue(struct mei_cl_cb *cb)
 350 {
 351         if (!WARN_ON(cb->cl->tx_cb_queued == 0))
 352                 cb->cl->tx_cb_queued--;
 353
 354         mei_io_cb_free(cb);
 355 }
 356
 357 /**
 358  * mei_io_cb_init - allocate and initialize io callback
 359  *
 360  * @cl: mei client
 361  * @type: operation type
 362  * @fp: pointer to file structure
 363  *
 364  * Return: mei_cl_cb pointer or NULL;
 365  */
 366 static struct mei_cl_cb *mei_io_cb_init(struct mei_cl *cl,
 367                                         enum mei_cb_file_ops type,
 368                                         const struct file *fp)
 369 {
 370         struct mei_cl_cb *cb;
 371
 372         cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
 373         if (!cb)
 374                 return NULL;
 375
 376         INIT_LIST_HEAD(&cb->list);
 377         cb->fp = fp;
 378         cb->cl = cl;
 379         cb->buf_idx = 0;
 380         cb->fop_type = type;
 381         return cb;
 382 }
 383
 384 /**
 385  * mei_io_list_flush_cl - removes cbs belonging to the cl.
 386  *
 387  * @head:  an instance of our list structure
 388  * @cl:    host client
 389  */
 390 static void mei_io_list_flush_cl(struct list_head *head,
 391                                  const struct mei_cl *cl)
 392 {
 393         struct mei_cl_cb *cb, *next;
 394
 395         list_for_each_entry_safe(cb, next, head, list) {
 396                 if (cl == cb->cl) {
 397                         list_del_init(&cb->list);
 398                         if (cb->fop_type == MEI_FOP_READ)
 399                                 mei_io_cb_free(cb);
 400                 }
 401         }
 402 }
 403
 404 /**
 405  * mei_io_tx_list_free_cl - removes cb belonging to the cl and free them
 406  *
 407  * @head: An instance of our list structure
 408  * @cl: host client
 409  */
 410 static void mei_io_tx_list_free_cl(struct list_head *head,
 411                                    const struct mei_cl *cl)
 412 {
 413         struct mei_cl_cb *cb, *next;
 414
 415         list_for_each_entry_safe(cb, next, head, list) {
 416                 if (cl == cb->cl)
 417                         mei_tx_cb_dequeue(cb);
 418         }
 419 }
 420
 421 /**
 422  * mei_io_list_free_fp - free cb from a list that matches file pointer
 423  *
 424  * @head: io list
 425  * @fp: file pointer (matching cb file object), may be NULL
 426  */
 427 static void mei_io_list_free_fp(struct list_head *head, const struct file *fp)
 428 {
 429         struct mei_cl_cb *cb, *next;
 430
 431         list_for_each_entry_safe(cb, next, head, list)
 432                 if (!fp || fp == cb->fp)
 433                         mei_io_cb_free(cb);
 434 }
 435
 436 /**
 437  * mei_cl_alloc_cb - a convenient wrapper for allocating read cb
 438  *
 439  * @cl: host client
 440  * @length: size of the buffer
 441  * @fop_type: operation type
 442  * @fp: associated file pointer (might be NULL)
 443  *
 444  * Return: cb on success and NULL on failure
 445  */
 446 struct mei_cl_cb *mei_cl_alloc_cb(struct mei_cl *cl, size_t length,
 447                                   enum mei_cb_file_ops fop_type,
 448                                   const struct file *fp)
 449 {
 450         struct mei_cl_cb *cb;
 451
 452         cb = mei_io_cb_init(cl, fop_type, fp);
 453         if (!cb)
 454                 return NULL;
 455
 456         if (length == 0)
 457                 return cb;
 458
 459         cb->buf.data = kmalloc(roundup(length, MEI_SLOT_SIZE), GFP_KERNEL);
 460         if (!cb->buf.data) {
 461                 mei_io_cb_free(cb);
 462                 return NULL;
 463         }
 464         cb->buf.size = length;
 465
 466         return cb;
 467 }
 468
 469 /**
 470  * mei_cl_enqueue_ctrl_wr_cb - a convenient wrapper for allocating
 471  *     and enqueuing of the control commands cb
 472  *
 473  * @cl: host client
 474  * @length: size of the buffer
 475  * @fop_type: operation type
 476  * @fp: associated file pointer (might be NULL)
 477  *
 478  * Return: cb on success and NULL on failure
 479  * Locking: called under "dev->device_lock" lock
 480  */
 481 struct mei_cl_cb *mei_cl_enqueue_ctrl_wr_cb(struct mei_cl *cl, size_t length,
 482                                             enum mei_cb_file_ops fop_type,
 483                                             const struct file *fp)
 484 {
 485         struct mei_cl_cb *cb;
 486
 487         /* for RX always allocate at least client's mtu */
 488         if (length)
 489                 length = max_t(size_t, length, mei_cl_mtu(cl));
 490
 491         cb = mei_cl_alloc_cb(cl, length, fop_type, fp);
 492         if (!cb)
 493                 return NULL;
 494
 495         list_add_tail(&cb->list, &cl->dev->ctrl_wr_list);
 496         return cb;
 497 }
 498
 499 /**
 500  * mei_cl_read_cb - find this cl's callback in the read list
 501  *     for a specific file
 502  *
 503  * @cl: host client
 504  * @fp: file pointer (matching cb file object), may be NULL
 505  *
 506  * Return: cb on success, NULL if cb is not found
 507  */
 508 struct mei_cl_cb *mei_cl_read_cb(const struct mei_cl *cl, const struct file *fp)
 509 {
 510         struct mei_cl_cb *cb;
 511
 512         list_for_each_entry(cb, &cl->rd_completed, list)
 513                 if (!fp || fp == cb->fp)
 514                         return cb;
 515
 516         return NULL;
 517 }
 518
 519 /**
 520  * mei_cl_flush_queues - flushes queue lists belonging to cl.
 521  *
 522  * @cl: host client
 523  * @fp: file pointer (matching cb file object), may be NULL
 524  *
 525  * Return: 0 on success, -EINVAL if cl or cl->dev is NULL.
 526  */
 527 int mei_cl_flush_queues(struct mei_cl *cl, const struct file *fp)
 528 {
 529         struct mei_device *dev;
 530
 531         if (WARN_ON(!cl || !cl->dev))
 532                 return -EINVAL;
 533
 534         dev = cl->dev;
 535
 536         cl_dbg(dev, cl, "remove list entry belonging to cl\n");
 537         mei_io_tx_list_free_cl(&cl->dev->write_list, cl);
 538         mei_io_tx_list_free_cl(&cl->dev->write_waiting_list, cl);
 539         mei_io_list_flush_cl(&cl->dev->ctrl_wr_list, cl);
 540         mei_io_list_flush_cl(&cl->dev->ctrl_rd_list, cl);
 541         mei_io_list_free_fp(&cl->rd_pending, fp);
 542         mei_io_list_free_fp(&cl->rd_completed, fp);
 543
 544         return 0;
 545 }
 546
 547 /**
 548  * mei_cl_init - initializes cl.
 549  *
 550  * @cl: host client to be initialized
 551  * @dev: mei device
 552  */
 553 static void mei_cl_init(struct mei_cl *cl, struct mei_device *dev)
 554 {
 555         memset(cl, 0, sizeof(struct mei_cl));
 556         init_waitqueue_head(&cl->wait);
 557         init_waitqueue_head(&cl->rx_wait);
 558         init_waitqueue_head(&cl->tx_wait);
 559         init_waitqueue_head(&cl->ev_wait);
 560         INIT_LIST_HEAD(&cl->rd_completed);
 561         INIT_LIST_HEAD(&cl->rd_pending);
 562         INIT_LIST_HEAD(&cl->link);
 563         cl->writing_state = MEI_IDLE;
 564         cl->state = MEI_FILE_UNINITIALIZED;
 565         cl->dev = dev;
 566 }
 567
 568 /**
 569  * mei_cl_allocate - allocates cl  structure and sets it up.
 570  *
 571  * @dev: mei device
 572  * Return:  The allocated file or NULL on failure
 573  */
 574 struct mei_cl *mei_cl_allocate(struct mei_device *dev)
 575 {
 576         struct mei_cl *cl;
 577
 578         cl = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
 579         if (!cl)
 580                 return NULL;
 581
 582         mei_cl_init(cl, dev);
 583
 584         return cl;
 585 }
 586
 587 /**
 588  * mei_cl_link - allocate host id in the host map
 589  *
 590  * @cl: host client
 591  *
 592  * Return: 0 on success
 593  *      -EINVAL on incorrect values
 594  *      -EMFILE if open count exceeded.
 595  */
 596 int mei_cl_link(struct mei_cl *cl)
 597 {
 598         struct mei_device *dev;
 599         int id;
 600
 601         if (WARN_ON(!cl || !cl->dev))
 602                 return -EINVAL;
 603
 604         dev = cl->dev;
 605
 606         id = find_first_zero_bit(dev->host_clients_map, MEI_CLIENTS_MAX);
 607         if (id >= MEI_CLIENTS_MAX) {
 608                 dev_err(dev->dev, "id exceeded %d", MEI_CLIENTS_MAX);
 609                 return -EMFILE;
 610         }
 611
 612         if (dev->open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
 613                 dev_err(dev->dev, "open_handle_count exceeded %d",
 614                         MEI_MAX_OPEN_HANDLE_COUNT);
 615                 return -EMFILE;
 616         }
 617
 618         dev->open_handle_count++;
 619
 620         cl->host_client_id = id;
 621         list_add_tail(&cl->link, &dev->file_list);
 622
 623         set_bit(id, dev->host_clients_map);
 624
 625         cl->state = MEI_FILE_INITIALIZING;
 626
 627         cl_dbg(dev, cl, "link cl\n");
 628         return 0;
 629 }
 630
 631 /**
 632  * mei_cl_unlink - remove host client from the list
 633  *
 634  * @cl: host client
 635  *
 636  * Return: always 0
 637  */
 638 int mei_cl_unlink(struct mei_cl *cl)
 639 {
 640         struct mei_device *dev;
 641
 642         /* don't shout on error exit path */
 643         if (!cl)
 644                 return 0;
 645
 646         if (WARN_ON(!cl->dev))
 647                 return 0;
 648
 649         dev = cl->dev;
 650
 651         cl_dbg(dev, cl, "unlink client");
 652
 653         if (dev->open_handle_count > 0)
 654                 dev->open_handle_count--;
 655
 656         /* never clear the 0 bit */
 657         if (cl->host_client_id)
 658                 clear_bit(cl->host_client_id, dev->host_clients_map);
 659
 660         list_del_init(&cl->link);
 661
 662         cl->state = MEI_FILE_UNINITIALIZED;
 663         cl->writing_state = MEI_IDLE;
 664
 665         WARN_ON(!list_empty(&cl->rd_completed) ||
 666                 !list_empty(&cl->rd_pending) ||
 667                 !list_empty(&cl->link));
 668
 669         return 0;
 670 }
 671
 672 void mei_host_client_init(struct mei_device *dev)
 673 {
 674         mei_set_devstate(dev, MEI_DEV_ENABLED);
 675         dev->reset_count = 0;
 676
 677         schedule_work(&dev->bus_rescan_work);
 678
 679         pm_runtime_mark_last_busy(dev->dev);
 680         dev_dbg(dev->dev, "rpm: autosuspend\n");
 681         pm_request_autosuspend(dev->dev);
 682 }
 683
 684 /**
 685  * mei_hbuf_acquire - try to acquire host buffer
 686  *
 687  * @dev: the device structure
 688  * Return: true if host buffer was acquired
 689  */
 690 bool mei_hbuf_acquire(struct mei_device *dev)
 691 {
 692         if (mei_pg_state(dev) == MEI_PG_ON ||
 693             mei_pg_in_transition(dev)) {
 694                 dev_dbg(dev->dev, "device is in pg\n");
 695                 return false;
 696         }
 697
 698         if (!dev->hbuf_is_ready) {
 699                 dev_dbg(dev->dev, "hbuf is not ready\n");
 700                 return false;
 701         }
 702
 703         dev->hbuf_is_ready = false;
 704
 705         return true;
 706 }
 707
 708 /**
 709  * mei_cl_wake_all - wake up readers, writers and event waiters so
 710  *                 they can be interrupted
 711  *
 712  * @cl: host client
 713  */
 714 static void mei_cl_wake_all(struct mei_cl *cl)
 715 {
 716         struct mei_device *dev = cl->dev;
 717
 718         /* synchronized under device mutex */
 719         if (waitqueue_active(&cl->rx_wait)) {
 720                 cl_dbg(dev, cl, "Waking up reading client!\n");
 721                 wake_up_interruptible(&cl->rx_wait);
 722         }
 723         /* synchronized under device mutex */
 724         if (waitqueue_active(&cl->tx_wait)) {
 725                 cl_dbg(dev, cl, "Waking up writing client!\n");
 726                 wake_up_interruptible(&cl->tx_wait);
 727         }
 728         /* synchronized under device mutex */
 729         if (waitqueue_active(&cl->ev_wait)) {
 730                 cl_dbg(dev, cl, "Waking up waiting for event clients!\n");
 731                 wake_up_interruptible(&cl->ev_wait);
 732         }
 733         /* synchronized under device mutex */
 734         if (waitqueue_active(&cl->wait)) {
 735                 cl_dbg(dev, cl, "Waking up ctrl write clients!\n");
 736                 wake_up(&cl->wait);
 737         }
 738 }
 739
 740 /**
 741  * mei_cl_set_disconnected - set disconnected state and clear
 742  *   associated states and resources
 743  *
 744  * @cl: host client
 745  */
 746 static void mei_cl_set_disconnected(struct mei_cl *cl)
 747 {
 748         struct mei_device *dev = cl->dev;
 749
 750         if (cl->state == MEI_FILE_DISCONNECTED ||
 751             cl->state <= MEI_FILE_INITIALIZING)
 752                 return;
 753
 754         cl->state = MEI_FILE_DISCONNECTED;
 755         mei_io_tx_list_free_cl(&dev->write_list, cl);
 756         mei_io_tx_list_free_cl(&dev->write_waiting_list, cl);
 757         mei_io_list_flush_cl(&dev->ctrl_rd_list, cl);
 758         mei_io_list_flush_cl(&dev->ctrl_wr_list, cl);
 759         mei_cl_wake_all(cl);
 760         cl->rx_flow_ctrl_creds = 0;
 761         cl->tx_flow_ctrl_creds = 0;
 762         cl->timer_count = 0;
 763
 764         if (!cl->me_cl)
 765                 return;
 766
 767         if (!WARN_ON(cl->me_cl->connect_count == 0))
 768                 cl->me_cl->connect_count--;
 769
 770         if (cl->me_cl->connect_count == 0)
 771                 cl->me_cl->tx_flow_ctrl_creds = 0;
 772
 773         mei_me_cl_put(cl->me_cl);
 774         cl->me_cl = NULL;
 775 }
 776
 777 static int mei_cl_set_connecting(struct mei_cl *cl, struct mei_me_client *me_cl)
 778 {
 779         if (!mei_me_cl_get(me_cl))
 780                 return -ENOENT;
 781
 782         /* only one connection is allowed for fixed address clients */
 783         if (me_cl->props.fixed_address) {
 784                 if (me_cl->connect_count) {
 785                         mei_me_cl_put(me_cl);
 786                         return -EBUSY;
 787                 }
 788         }
 789
 790         cl->me_cl = me_cl;
 791         cl->state = MEI_FILE_CONNECTING;
 792         cl->me_cl->connect_count++;
 793
 794         return 0;
 795 }
 796
 797 /*
 798  * mei_cl_send_disconnect - send disconnect request
 799  *
 800  * @cl: host client
 801  * @cb: callback block
 802  *
 803  * Return: 0, OK; otherwise, error.
 804  */
 805 static int mei_cl_send_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb)
 806 {
 807         struct mei_device *dev;
 808         int ret;
 809
 810         dev = cl->dev;
 811
 812         ret = mei_hbm_cl_disconnect_req(dev, cl);
 813         cl->status = ret;
 814         if (ret) {
 815                 cl->state = MEI_FILE_DISCONNECT_REPLY;
 816                 return ret;
 817         }
 818
 819         list_move_tail(&cb->list, &dev->ctrl_rd_list);
 820         cl->timer_count = MEI_CONNECT_TIMEOUT;
 821         mei_schedule_stall_timer(dev);
 822
 823         return 0;
 824 }
 825
 826 /**
 827  * mei_cl_irq_disconnect - processes close related operation from
 828  *      interrupt thread context - send disconnect request
 829  *
 830  * @cl: client
 831  * @cb: callback block.
 832  * @cmpl_list: complete list.
 833  *
 834  * Return: 0, OK; otherwise, error.
 835  */
 836 int mei_cl_irq_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb,
 837                           struct list_head *cmpl_list)
 838 {
 839         struct mei_device *dev = cl->dev;
 840         u32 msg_slots;
 841         int slots;
 842         int ret;
 843
 844         msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_request));
 845         slots = mei_hbuf_empty_slots(dev);
 846         if (slots < 0)
 847                 return -EOVERFLOW;
 848
 849         if ((u32)slots < msg_slots)
 850                 return -EMSGSIZE;
 851
 852         ret = mei_cl_send_disconnect(cl, cb);
 853         if (ret)
 854                 list_move_tail(&cb->list, cmpl_list);
 855
 856         return ret;
 857 }
 858
 859 /**
 860  * __mei_cl_disconnect - disconnect host client from the me one
 861  *     internal function runtime pm has to be already acquired
 862  *
 863  * @cl: host client
 864  *
 865  * Return: 0 on success, <0 on failure.
 866  */
 867 static int __mei_cl_disconnect(struct mei_cl *cl)
 868 {
 869         struct mei_device *dev;
 870         struct mei_cl_cb *cb;
 871         int rets;
 872
 873         dev = cl->dev;
 874
 875         cl->state = MEI_FILE_DISCONNECTING;
 876
 877         cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_DISCONNECT, NULL);
 878         if (!cb) {
 879                 rets = -ENOMEM;
 880                 goto out;
 881         }
 882
 883         if (mei_hbuf_acquire(dev)) {
 884                 rets = mei_cl_send_disconnect(cl, cb);
 885                 if (rets) {
 886                         cl_err(dev, cl, "failed to disconnect.\n");
 887                         goto out;
 888                 }
 889         }
 890
 891         mutex_unlock(&dev->device_lock);
 892         wait_event_timeout(cl->wait,
 893                            cl->state == MEI_FILE_DISCONNECT_REPLY ||
 894                            cl->state == MEI_FILE_DISCONNECTED,
 895                            mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 896         mutex_lock(&dev->device_lock);
 897
 898         rets = cl->status;
 899         if (cl->state != MEI_FILE_DISCONNECT_REPLY &&
 900             cl->state != MEI_FILE_DISCONNECTED) {
 901                 cl_dbg(dev, cl, "timeout on disconnect from FW client.\n");
 902                 rets = -ETIME;
 903         }
 904
 905 out:
 906         /* we disconnect also on error */
 907         mei_cl_set_disconnected(cl);
 908         if (!rets)
 909                 cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
 910
 911         mei_io_cb_free(cb);
 912         return rets;
 913 }
 914
 915 /**
 916  * mei_cl_disconnect - disconnect host client from the me one
 917  *
 918  * @cl: host client
 919  *
 920  * Locking: called under "dev->device_lock" lock
 921  *
 922  * Return: 0 on success, <0 on failure.
 923  */
 924 int mei_cl_disconnect(struct mei_cl *cl)
 925 {
 926         struct mei_device *dev;
 927         int rets;
 928
 929         if (WARN_ON(!cl || !cl->dev))
 930                 return -ENODEV;
 931
 932         dev = cl->dev;
 933
 934         cl_dbg(dev, cl, "disconnecting");
 935
 936         if (!mei_cl_is_connected(cl))
 937                 return 0;
 938
 939         if (mei_cl_is_fixed_address(cl)) {
 940                 mei_cl_set_disconnected(cl);
 941                 return 0;
 942         }
 943
 944         if (dev->dev_state == MEI_DEV_POWER_DOWN) {
 945                 cl_dbg(dev, cl, "Device is powering down, don't bother with disconnection\n");
 946                 mei_cl_set_disconnected(cl);
 947                 return 0;
 948         }
 949
 950         rets = pm_runtime_get(dev->dev);
 951         if (rets < 0 && rets != -EINPROGRESS) {
 952                 pm_runtime_put_noidle(dev->dev);
 953                 cl_err(dev, cl, "rpm: get failed %d\n", rets);
 954                 return rets;
 955         }
 956
 957         rets = __mei_cl_disconnect(cl);
 958
 959         cl_dbg(dev, cl, "rpm: autosuspend\n");
 960         pm_runtime_mark_last_busy(dev->dev);
 961         pm_runtime_put_autosuspend(dev->dev);
 962
 963         return rets;
 964 }
 965
 966
 967 /**
 968  * mei_cl_is_other_connecting - checks if other
 969  *    client with the same me client id is connecting
 970  *
 971  * @cl: private data of the file object
 972  *
 973  * Return: true if other client is connected, false - otherwise.
 974  */
 975 static bool mei_cl_is_other_connecting(struct mei_cl *cl)
 976 {
 977         struct mei_device *dev;
 978         struct mei_cl_cb *cb;
 979
 980         dev = cl->dev;
 981
 982         list_for_each_entry(cb, &dev->ctrl_rd_list, list) {
 983                 if (cb->fop_type == MEI_FOP_CONNECT &&
 984                     mei_cl_me_id(cl) == mei_cl_me_id(cb->cl))
 985                         return true;
 986         }
 987
 988         return false;
 989 }
 990
 991 /**
 992  * mei_cl_send_connect - send connect request
 993  *
 994  * @cl: host client
 995  * @cb: callback block
 996  *
 997  * Return: 0, OK; otherwise, error.
 998  */
 999 static int mei_cl_send_connect(struct mei_cl *cl, struct mei_cl_cb *cb)
1000 {
1001         struct mei_device *dev;
1002         int ret;
1003
1004         dev = cl->dev;
1005
1006         ret = mei_hbm_cl_connect_req(dev, cl);
1007         cl->status = ret;
1008         if (ret) {
1009                 cl->state = MEI_FILE_DISCONNECT_REPLY;
1010                 return ret;
1011         }
1012
1013         list_move_tail(&cb->list, &dev->ctrl_rd_list);
1014         cl->timer_count = MEI_CONNECT_TIMEOUT;
1015         mei_schedule_stall_timer(dev);
1016         return 0;
1017 }
1018
1019 /**
1020  * mei_cl_irq_connect - send connect request in irq_thread context
1021  *
1022  * @cl: host client
1023  * @cb: callback block
1024  * @cmpl_list: complete list
1025  *
1026  * Return: 0, OK; otherwise, error.
1027  */
1028 int mei_cl_irq_connect(struct mei_cl *cl, struct mei_cl_cb *cb,
1029                        struct list_head *cmpl_list)
1030 {
1031         struct mei_device *dev = cl->dev;
1032         u32 msg_slots;
1033         int slots;
1034         int rets;
1035
1036         if (mei_cl_is_other_connecting(cl))
1037                 return 0;
1038
1039         msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_request));
1040         slots = mei_hbuf_empty_slots(dev);
1041         if (slots < 0)
1042                 return -EOVERFLOW;
1043
1044         if ((u32)slots < msg_slots)
1045                 return -EMSGSIZE;
1046
1047         rets = mei_cl_send_connect(cl, cb);
1048         if (rets)
1049                 list_move_tail(&cb->list, cmpl_list);
1050
1051         return rets;
1052 }
1053
1054 /**
1055  * mei_cl_connect - connect host client to the me one
1056  *
1057  * @cl: host client
1058  * @me_cl: me client
1059  * @fp: pointer to file structure
1060  *
1061  * Locking: called under "dev->device_lock" lock
1062  *
1063  * Return: 0 on success, <0 on failure.
1064  */
1065 int mei_cl_connect(struct mei_cl *cl, struct mei_me_client *me_cl,
1066                    const struct file *fp)
1067 {
1068         struct mei_device *dev;
1069         struct mei_cl_cb *cb;
1070         int rets;
1071
1072         if (WARN_ON(!cl || !cl->dev || !me_cl))
1073                 return -ENODEV;
1074
1075         dev = cl->dev;
1076
1077         rets = mei_cl_set_connecting(cl, me_cl);
1078         if (rets)
1079                 goto nortpm;
1080
1081         if (mei_cl_is_fixed_address(cl)) {
1082                 cl->state = MEI_FILE_CONNECTED;
1083                 rets = 0;
1084                 goto nortpm;
1085         }
1086
1087         rets = pm_runtime_get(dev->dev);
1088         if (rets < 0 && rets != -EINPROGRESS) {
1089                 pm_runtime_put_noidle(dev->dev);
1090                 cl_err(dev, cl, "rpm: get failed %d\n", rets);
1091                 goto nortpm;
1092         }
1093
1094         cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_CONNECT, fp);
1095         if (!cb) {
1096                 rets = -ENOMEM;
1097                 goto out;
1098         }
1099
1100         /* run hbuf acquire last so we don't have to undo */
1101         if (!mei_cl_is_other_connecting(cl) && mei_hbuf_acquire(dev)) {
1102                 rets = mei_cl_send_connect(cl, cb);
1103                 if (rets)
1104                         goto out;
1105         }
1106
1107         mutex_unlock(&dev->device_lock);
1108         wait_event_timeout(cl->wait,
1109                         (cl->state == MEI_FILE_CONNECTED ||
1110                          cl->state == MEI_FILE_DISCONNECTED ||
1111                          cl->state == MEI_FILE_DISCONNECT_REQUIRED ||
1112                          cl->state == MEI_FILE_DISCONNECT_REPLY),
1113                         mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1114         mutex_lock(&dev->device_lock);
1115
1116         if (!mei_cl_is_connected(cl)) {
1117                 if (cl->state == MEI_FILE_DISCONNECT_REQUIRED) {
1118                         mei_io_list_flush_cl(&dev->ctrl_rd_list, cl);
1119                         mei_io_list_flush_cl(&dev->ctrl_wr_list, cl);
1120                          /* ignore disconnect return valuue;
1121                           * in case of failure reset will be invoked
1122                           */
1123                         __mei_cl_disconnect(cl);
1124                         rets = -EFAULT;
1125                         goto out;
1126                 }
1127
1128                 /* timeout or something went really wrong */
1129                 if (!cl->status)
1130                         cl->status = -EFAULT;
1131         }
1132
1133         rets = cl->status;
1134 out:
1135         cl_dbg(dev, cl, "rpm: autosuspend\n");
1136         pm_runtime_mark_last_busy(dev->dev);
1137         pm_runtime_put_autosuspend(dev->dev);
1138
1139         mei_io_cb_free(cb);
1140
1141 nortpm:
1142         if (!mei_cl_is_connected(cl))
1143                 mei_cl_set_disconnected(cl);
1144
1145         return rets;
1146 }
1147
1148 /**
1149  * mei_cl_alloc_linked - allocate and link host client
1150  *
1151  * @dev: the device structure
1152  *
1153  * Return: cl on success ERR_PTR on failure
1154  */
1155 struct mei_cl *mei_cl_alloc_linked(struct mei_device *dev)
1156 {
1157         struct mei_cl *cl;
1158         int ret;
1159
1160         cl = mei_cl_allocate(dev);
1161         if (!cl) {
1162                 ret = -ENOMEM;
1163                 goto err;
1164         }
1165
1166         ret = mei_cl_link(cl);
1167         if (ret)
1168                 goto err;
1169
1170         return cl;
1171 err:
1172         kfree(cl);
1173         return ERR_PTR(ret);
1174 }
1175
1176 /**
1177  * mei_cl_tx_flow_ctrl_creds - checks flow_control credits for cl.
1178  *
1179  * @cl: host client
1180  *
1181  * Return: 1 if tx_flow_ctrl_creds >0, 0 - otherwise.
1182  */
1183 static int mei_cl_tx_flow_ctrl_creds(struct mei_cl *cl)
1184 {
1185         if (WARN_ON(!cl || !cl->me_cl))
1186                 return -EINVAL;
1187
1188         if (cl->tx_flow_ctrl_creds > 0)
1189                 return 1;
1190
1191         if (mei_cl_is_fixed_address(cl))
1192                 return 1;
1193
1194         if (mei_cl_is_single_recv_buf(cl)) {
1195                 if (cl->me_cl->tx_flow_ctrl_creds > 0)
1196                         return 1;
1197         }
1198         return 0;
1199 }
1200
1201 /**
1202  * mei_cl_tx_flow_ctrl_creds_reduce - reduces transmit flow control credits
1203  *   for a client
1204  *
1205  * @cl: host client
1206  *
1207  * Return:
1208  *      0 on success
1209  *      -EINVAL when ctrl credits are <= 0
1210  */
1211 static int mei_cl_tx_flow_ctrl_creds_reduce(struct mei_cl *cl)
1212 {
1213         if (WARN_ON(!cl || !cl->me_cl))
1214                 return -EINVAL;
1215
1216         if (mei_cl_is_fixed_address(cl))
1217                 return 0;
1218
1219         if (mei_cl_is_single_recv_buf(cl)) {
1220                 if (WARN_ON(cl->me_cl->tx_flow_ctrl_creds <= 0))
1221                         return -EINVAL;
1222                 cl->me_cl->tx_flow_ctrl_creds--;
1223         } else {
1224                 if (WARN_ON(cl->tx_flow_ctrl_creds <= 0))
1225                         return -EINVAL;
1226                 cl->tx_flow_ctrl_creds--;
1227         }
1228         return 0;
1229 }
1230
1231 /**
1232  *  mei_cl_notify_fop2req - convert fop to proper request
1233  *
1234  * @fop: client notification start response command
1235  *
1236  * Return:  MEI_HBM_NOTIFICATION_START/STOP
1237  */
1238 u8 mei_cl_notify_fop2req(enum mei_cb_file_ops fop)
1239 {
1240         if (fop == MEI_FOP_NOTIFY_START)
1241                 return MEI_HBM_NOTIFICATION_START;
1242         else
1243                 return MEI_HBM_NOTIFICATION_STOP;
1244 }
1245
1246 /**
1247  *  mei_cl_notify_req2fop - convert notification request top file operation type
1248  *
1249  * @req: hbm notification request type
1250  *
1251  * Return:  MEI_FOP_NOTIFY_START/STOP
1252  */
1253 enum mei_cb_file_ops mei_cl_notify_req2fop(u8 req)
1254 {
1255         if (req == MEI_HBM_NOTIFICATION_START)
1256                 return MEI_FOP_NOTIFY_START;
1257         else
1258                 return MEI_FOP_NOTIFY_STOP;
1259 }
1260
1261 /**
1262  * mei_cl_irq_notify - send notification request in irq_thread context
1263  *
1264  * @cl: client
1265  * @cb: callback block.
1266  * @cmpl_list: complete list.
1267  *
1268  * Return: 0 on such and error otherwise.
1269  */
1270 int mei_cl_irq_notify(struct mei_cl *cl, struct mei_cl_cb *cb,
1271                       struct list_head *cmpl_list)
1272 {
1273         struct mei_device *dev = cl->dev;
1274         u32 msg_slots;
1275         int slots;
1276         int ret;
1277         bool request;
1278
1279         msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_request));
1280         slots = mei_hbuf_empty_slots(dev);
1281         if (slots < 0)
1282                 return -EOVERFLOW;
1283
1284         if ((u32)slots < msg_slots)
1285                 return -EMSGSIZE;
1286
1287         request = mei_cl_notify_fop2req(cb->fop_type);
1288         ret = mei_hbm_cl_notify_req(dev, cl, request);
1289         if (ret) {
1290                 cl->status = ret;
1291                 list_move_tail(&cb->list, cmpl_list);
1292                 return ret;
1293         }
1294
1295         list_move_tail(&cb->list, &dev->ctrl_rd_list);
1296         return 0;
1297 }
1298
1299 /**
1300  * mei_cl_notify_request - send notification stop/start request
1301  *
1302  * @cl: host client
1303  * @fp: associate request with file
1304  * @request: 1 for start or 0 for stop
1305  *
1306  * Locking: called under "dev->device_lock" lock
1307  *
1308  * Return: 0 on such and error otherwise.
1309  */
1310 int mei_cl_notify_request(struct mei_cl *cl,
1311                           const struct file *fp, u8 request)
1312 {
1313         struct mei_device *dev;
1314         struct mei_cl_cb *cb;
1315         enum mei_cb_file_ops fop_type;
1316         int rets;
1317
1318         if (WARN_ON(!cl || !cl->dev))
1319                 return -ENODEV;
1320
1321         dev = cl->dev;
1322
1323         if (!dev->hbm_f_ev_supported) {
1324                 cl_dbg(dev, cl, "notifications not supported\n");
1325                 return -EOPNOTSUPP;
1326         }
1327
1328         if (!mei_cl_is_connected(cl))
1329                 return -ENODEV;
1330
1331         rets = pm_runtime_get(dev->dev);
1332         if (rets < 0 && rets != -EINPROGRESS) {
1333                 pm_runtime_put_noidle(dev->dev);
1334                 cl_err(dev, cl, "rpm: get failed %d\n", rets);
1335                 return rets;
1336         }
1337
1338         fop_type = mei_cl_notify_req2fop(request);
1339         cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, fop_type, fp);
1340         if (!cb) {
1341                 rets = -ENOMEM;
1342                 goto out;
1343         }
1344
1345         if (mei_hbuf_acquire(dev)) {
1346                 if (mei_hbm_cl_notify_req(dev, cl, request)) {
1347                         rets = -ENODEV;
1348                         goto out;
1349                 }
1350                 list_move_tail(&cb->list, &dev->ctrl_rd_list);
1351         }
1352
1353         mutex_unlock(&dev->device_lock);
1354         wait_event_timeout(cl->wait,
1355                            cl->notify_en == request ||
1356                            cl->status ||
1357                            !mei_cl_is_connected(cl),
1358                            mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1359         mutex_lock(&dev->device_lock);
1360
1361         if (cl->notify_en != request && !cl->status)
1362                 cl->status = -EFAULT;
1363
1364         rets = cl->status;
1365
1366 out:
1367         cl_dbg(dev, cl, "rpm: autosuspend\n");
1368         pm_runtime_mark_last_busy(dev->dev);
1369         pm_runtime_put_autosuspend(dev->dev);
1370
1371         mei_io_cb_free(cb);
1372         return rets;
1373 }
1374
1375 /**
1376  * mei_cl_notify - raise notification
1377  *
1378  * @cl: host client
1379  *
1380  * Locking: called under "dev->device_lock" lock
1381  */
1382 void mei_cl_notify(struct mei_cl *cl)
1383 {
1384         struct mei_device *dev;
1385
1386         if (!cl || !cl->dev)
1387                 return;
1388
1389         dev = cl->dev;
1390
1391         if (!cl->notify_en)
1392                 return;
1393
1394         cl_dbg(dev, cl, "notify event");
1395         cl->notify_ev = true;
1396         if (!mei_cl_bus_notify_event(cl))
1397                 wake_up_interruptible(&cl->ev_wait);
1398
1399         if (cl->ev_async)
1400                 kill_fasync(&cl->ev_async, SIGIO, POLL_PRI);
1401
1402 }
1403
1404 /**
1405  * mei_cl_notify_get - get or wait for notification event
1406  *
1407  * @cl: host client
1408  * @block: this request is blocking
1409  * @notify_ev: true if notification event was received
1410  *
1411  * Locking: called under "dev->device_lock" lock
1412  *
1413  * Return: 0 on such and error otherwise.
1414  */
1415 int mei_cl_notify_get(struct mei_cl *cl, bool block, bool *notify_ev)
1416 {
1417         struct mei_device *dev;
1418         int rets;
1419
1420         *notify_ev = false;
1421
1422         if (WARN_ON(!cl || !cl->dev))
1423                 return -ENODEV;
1424
1425         dev = cl->dev;
1426
1427         if (!dev->hbm_f_ev_supported) {
1428                 cl_dbg(dev, cl, "notifications not supported\n");
1429                 return -EOPNOTSUPP;
1430         }
1431
1432         if (!mei_cl_is_connected(cl))
1433                 return -ENODEV;
1434
1435         if (cl->notify_ev)
1436                 goto out;
1437
1438         if (!block)
1439                 return -EAGAIN;
1440
1441         mutex_unlock(&dev->device_lock);
1442         rets = wait_event_interruptible(cl->ev_wait, cl->notify_ev);
1443         mutex_lock(&dev->device_lock);
1444
1445         if (rets < 0)
1446                 return rets;
1447
1448 out:
1449         *notify_ev = cl->notify_ev;
1450         cl->notify_ev = false;
1451         return 0;
1452 }
1453
1454 /**
1455  * mei_cl_read_start - the start read client message function.
1456  *
1457  * @cl: host client
1458  * @length: number of bytes to read
1459  * @fp: pointer to file structure
1460  *
1461  * Return: 0 on success, <0 on failure.
1462  */
1463 int mei_cl_read_start(struct mei_cl *cl, size_t length, const struct file *fp)
1464 {
1465         struct mei_device *dev;
1466         struct mei_cl_cb *cb;
1467         int rets;
1468
1469         if (WARN_ON(!cl || !cl->dev))
1470                 return -ENODEV;
1471
1472         dev = cl->dev;
1473
1474         if (!mei_cl_is_connected(cl))
1475                 return -ENODEV;
1476
1477         if (!mei_me_cl_is_active(cl->me_cl)) {
1478                 cl_err(dev, cl, "no such me client\n");
1479                 return  -ENOTTY;
1480         }
1481
1482         if (mei_cl_is_fixed_address(cl))
1483                 return 0;
1484
1485         /* HW currently supports only one pending read */
1486         if (cl->rx_flow_ctrl_creds)
1487                 return -EBUSY;
1488
1489         cb = mei_cl_enqueue_ctrl_wr_cb(cl, length, MEI_FOP_READ, fp);
1490         if (!cb)
1491                 return -ENOMEM;
1492
1493         rets = pm_runtime_get(dev->dev);
1494         if (rets < 0 && rets != -EINPROGRESS) {
1495                 pm_runtime_put_noidle(dev->dev);
1496                 cl_err(dev, cl, "rpm: get failed %d\n", rets);
1497                 goto nortpm;
1498         }
1499
1500         rets = 0;
1501         if (mei_hbuf_acquire(dev)) {
1502                 rets = mei_hbm_cl_flow_control_req(dev, cl);
1503                 if (rets < 0)
1504                         goto out;
1505
1506                 list_move_tail(&cb->list, &cl->rd_pending);
1507         }
1508         cl->rx_flow_ctrl_creds++;
1509
1510 out:
1511         cl_dbg(dev, cl, "rpm: autosuspend\n");
1512         pm_runtime_mark_last_busy(dev->dev);
1513         pm_runtime_put_autosuspend(dev->dev);
1514 nortpm:
1515         if (rets)
1516                 mei_io_cb_free(cb);
1517
1518         return rets;
1519 }
1520
1521 /**
1522  * mei_msg_hdr_init - initialize mei message header
1523  *
1524  * @mei_hdr: mei message header
1525  * @cb: message callback structure
1526  */
1527 static void mei_msg_hdr_init(struct mei_msg_hdr *mei_hdr, struct mei_cl_cb *cb)
1528 {
1529         mei_hdr->host_addr = mei_cl_host_addr(cb->cl);
1530         mei_hdr->me_addr = mei_cl_me_id(cb->cl);
1531         mei_hdr->length = 0;
1532         mei_hdr->reserved = 0;
1533         mei_hdr->msg_complete = 0;
1534         mei_hdr->dma_ring = 0;
1535         mei_hdr->internal = cb->internal;
1536 }
1537
1538 /**
1539  * mei_cl_irq_write - write a message to device
1540  *      from the interrupt thread context
1541  *
1542  * @cl: client
1543  * @cb: callback block.
1544  * @cmpl_list: complete list.
1545  *
1546  * Return: 0, OK; otherwise error.
1547  */
1548 int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
1549                      struct list_head *cmpl_list)
1550 {
1551         struct mei_device *dev;
1552         struct mei_msg_data *buf;
1553         struct mei_msg_hdr mei_hdr;
1554         size_t hdr_len = sizeof(mei_hdr);
1555         size_t len;
1556         size_t hbuf_len, dr_len;
1557         int hbuf_slots;
1558         u32 dr_slots;
1559         u32 dma_len;
1560         int rets;
1561         bool first_chunk;
1562         const void *data;
1563
1564         if (WARN_ON(!cl || !cl->dev))
1565                 return -ENODEV;
1566
1567         dev = cl->dev;
1568
1569         buf = &cb->buf;
1570
1571         first_chunk = cb->buf_idx == 0;
1572
1573         rets = first_chunk ? mei_cl_tx_flow_ctrl_creds(cl) : 1;
1574         if (rets < 0)
1575                 goto err;
1576
1577         if (rets == 0) {
1578                 cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1579                 return 0;
1580         }
1581
1582         len = buf->size - cb->buf_idx;
1583         data = buf->data + cb->buf_idx;
1584         hbuf_slots = mei_hbuf_empty_slots(dev);
1585         if (hbuf_slots < 0) {
1586                 rets = -EOVERFLOW;
1587                 goto err;
1588         }
1589
1590         hbuf_len = mei_slots2data(hbuf_slots) & MEI_MSG_MAX_LEN_MASK;
1591         dr_slots = mei_dma_ring_empty_slots(dev);
1592         dr_len = mei_slots2data(dr_slots);
1593
1594         mei_msg_hdr_init(&mei_hdr, cb);
1595
1596         /**
1597          * Split the message only if we can write the whole host buffer
1598          * otherwise wait for next time the host buffer is empty.
1599          */
1600         if (len + hdr_len <= hbuf_len) {
1601                 mei_hdr.length = len;
1602                 mei_hdr.msg_complete = 1;
1603         } else if (dr_slots && hbuf_len >= hdr_len + sizeof(dma_len)) {
1604                 mei_hdr.dma_ring = 1;
1605                 if (len > dr_len)
1606                         len = dr_len;
1607                 else
1608                         mei_hdr.msg_complete = 1;
1609
1610                 mei_hdr.length = sizeof(dma_len);
1611                 dma_len = len;
1612                 data = &dma_len;
1613         } else if ((u32)hbuf_slots == mei_hbuf_depth(dev)) {
1614                 len = hbuf_len - hdr_len;
1615                 mei_hdr.length = len;
1616         } else {
1617                 return 0;
1618         }
1619
1620         if (mei_hdr.dma_ring)
1621                 mei_dma_ring_write(dev, buf->data + cb->buf_idx, len);
1622
1623         rets = mei_write_message(dev, &mei_hdr, hdr_len, data, mei_hdr.length);
1624         if (rets)
1625                 goto err;
1626
1627         cl->status = 0;
1628         cl->writing_state = MEI_WRITING;
1629         cb->buf_idx += len;
1630
1631         if (first_chunk) {
1632                 if (mei_cl_tx_flow_ctrl_creds_reduce(cl)) {
1633                         rets = -EIO;
1634                         goto err;
1635                 }
1636         }
1637
1638         if (mei_hdr.msg_complete)
1639                 list_move_tail(&cb->list, &dev->write_waiting_list);
1640
1641         return 0;
1642
1643 err:
1644         cl->status = rets;
1645         list_move_tail(&cb->list, cmpl_list);
1646         return rets;
1647 }
1648
1649 /**
1650  * mei_cl_write - submit a write cb to mei device
1651  *      assumes device_lock is locked
1652  *
1653  * @cl: host client
1654  * @cb: write callback with filled data
1655  *
1656  * Return: number of bytes sent on success, <0 on failure.
1657  */
1658 ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb)
1659 {
1660         struct mei_device *dev;
1661         struct mei_msg_data *buf;
1662         struct mei_msg_hdr mei_hdr;
1663         size_t hdr_len = sizeof(mei_hdr);
1664         size_t len, hbuf_len, dr_len;
1665         int hbuf_slots;
1666         u32 dr_slots;
1667         u32 dma_len;
1668         ssize_t rets;
1669         bool blocking;
1670         const void *data;
1671
1672         if (WARN_ON(!cl || !cl->dev))
1673                 return -ENODEV;
1674
1675         if (WARN_ON(!cb))
1676                 return -EINVAL;
1677
1678         dev = cl->dev;
1679
1680         buf = &cb->buf;
1681         len = buf->size;
1682
1683         cl_dbg(dev, cl, "len=%zd\n", len);
1684
1685         blocking = cb->blocking;
1686         data = buf->data;
1687
1688         rets = pm_runtime_get(dev->dev);
1689         if (rets < 0 && rets != -EINPROGRESS) {
1690                 pm_runtime_put_noidle(dev->dev);
1691                 cl_err(dev, cl, "rpm: get failed %zd\n", rets);
1692                 goto free;
1693         }
1694
1695         cb->buf_idx = 0;
1696         cl->writing_state = MEI_IDLE;
1697
1698
1699         rets = mei_cl_tx_flow_ctrl_creds(cl);
1700         if (rets < 0)
1701                 goto err;
1702
1703         mei_msg_hdr_init(&mei_hdr, cb);
1704
1705         if (rets == 0) {
1706                 cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1707                 rets = len;
1708                 goto out;
1709         }
1710
1711         if (!mei_hbuf_acquire(dev)) {
1712                 cl_dbg(dev, cl, "Cannot acquire the host buffer: not sending.\n");
1713                 rets = len;
1714                 goto out;
1715         }
1716
1717         hbuf_slots = mei_hbuf_empty_slots(dev);
1718         if (hbuf_slots < 0) {
1719                 rets = -EOVERFLOW;
1720                 goto out;
1721         }
1722
1723         hbuf_len = mei_slots2data(hbuf_slots) & MEI_MSG_MAX_LEN_MASK;
1724         dr_slots = mei_dma_ring_empty_slots(dev);
1725         dr_len =  mei_slots2data(dr_slots);
1726
1727         if (len + hdr_len <= hbuf_len) {
1728                 mei_hdr.length = len;
1729                 mei_hdr.msg_complete = 1;
1730         } else if (dr_slots && hbuf_len >= hdr_len + sizeof(dma_len)) {
1731                 mei_hdr.dma_ring = 1;
1732                 if (len > dr_len)
1733                         len = dr_len;
1734                 else
1735                         mei_hdr.msg_complete = 1;
1736
1737                 mei_hdr.length = sizeof(dma_len);
1738                 dma_len = len;
1739                 data = &dma_len;
1740         } else {
1741                 len = hbuf_len - hdr_len;
1742                 mei_hdr.length = len;
1743         }
1744
1745         if (mei_hdr.dma_ring)
1746                 mei_dma_ring_write(dev, buf->data, len);
1747
1748         rets = mei_write_message(dev, &mei_hdr, hdr_len,
1749                                  data, mei_hdr.length);
1750         if (rets)
1751                 goto err;
1752
1753         rets = mei_cl_tx_flow_ctrl_creds_reduce(cl);
1754         if (rets)
1755                 goto err;
1756
1757         cl->writing_state = MEI_WRITING;
1758         cb->buf_idx = len;
1759         /* restore return value */
1760         len = buf->size;
1761
1762 out:
1763         if (mei_hdr.msg_complete)
1764                 mei_tx_cb_enqueue(cb, &dev->write_waiting_list);
1765         else
1766                 mei_tx_cb_enqueue(cb, &dev->write_list);
1767
1768         cb = NULL;
1769         if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
1770
1771                 mutex_unlock(&dev->device_lock);
1772                 rets = wait_event_interruptible(cl->tx_wait,
1773                                 cl->writing_state == MEI_WRITE_COMPLETE ||
1774                                 (!mei_cl_is_connected(cl)));
1775                 mutex_lock(&dev->device_lock);
1776                 /* wait_event_interruptible returns -ERESTARTSYS */
1777                 if (rets) {
1778                         if (signal_pending(current))
1779                                 rets = -EINTR;
1780                         goto err;
1781                 }
1782                 if (cl->writing_state != MEI_WRITE_COMPLETE) {
1783                         rets = -EFAULT;
1784                         goto err;
1785                 }
1786         }
1787
1788         rets = len;
1789 err:
1790         cl_dbg(dev, cl, "rpm: autosuspend\n");
1791         pm_runtime_mark_last_busy(dev->dev);
1792         pm_runtime_put_autosuspend(dev->dev);
1793 free:
1794         mei_io_cb_free(cb);
1795
1796         return rets;
1797 }
1798
1799
1800 /**
1801  * mei_cl_complete - processes completed operation for a client
1802  *
1803  * @cl: private data of the file object.
1804  * @cb: callback block.
1805  */
1806 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
1807 {
1808         struct mei_device *dev = cl->dev;
1809
1810         switch (cb->fop_type) {
1811         case MEI_FOP_WRITE:
1812                 mei_tx_cb_dequeue(cb);
1813                 cl->writing_state = MEI_WRITE_COMPLETE;
1814                 if (waitqueue_active(&cl->tx_wait)) {
1815                         wake_up_interruptible(&cl->tx_wait);
1816                 } else {
1817                         pm_runtime_mark_last_busy(dev->dev);
1818                         pm_request_autosuspend(dev->dev);
1819                 }
1820                 break;
1821
1822         case MEI_FOP_READ:
1823                 list_add_tail(&cb->list, &cl->rd_completed);
1824                 if (!mei_cl_is_fixed_address(cl) &&
1825                     !WARN_ON(!cl->rx_flow_ctrl_creds))
1826                         cl->rx_flow_ctrl_creds--;
1827                 if (!mei_cl_bus_rx_event(cl))
1828                         wake_up_interruptible(&cl->rx_wait);
1829                 break;
1830
1831         case MEI_FOP_CONNECT:
1832         case MEI_FOP_DISCONNECT:
1833         case MEI_FOP_NOTIFY_STOP:
1834         case MEI_FOP_NOTIFY_START:
1835                 if (waitqueue_active(&cl->wait))
1836                         wake_up(&cl->wait);
1837
1838                 break;
1839         case MEI_FOP_DISCONNECT_RSP:
1840                 mei_io_cb_free(cb);
1841                 mei_cl_set_disconnected(cl);
1842                 break;
1843         default:
1844                 BUG_ON(0);
1845         }
1846 }
1847
1848
1849 /**
1850  * mei_cl_all_disconnect - disconnect forcefully all connected clients
1851  *
1852  * @dev: mei device
1853  */
1854 void mei_cl_all_disconnect(struct mei_device *dev)
1855 {
1856         struct mei_cl *cl;
1857
1858         list_for_each_entry(cl, &dev->file_list, link)
1859                 mei_cl_set_disconnected(cl);
1860 }