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