drivers/misc/mei/client.c

   1 /*
   2  *
   3  * Intel Management Engine Interface (Intel MEI) Linux driver
   4  * Copyright (c) 2003-2012, Intel Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  */
  16
  17 #include <linux/sched/signal.h>
  18 #include <linux/wait.h>
  19 #include <linux/delay.h>
  20 #include <linux/slab.h>
  21 #include <linux/pm_runtime.h>
  22
  23 #include <linux/mei.h>
  24
  25 #include "mei_dev.h"
  26 #include "hbm.h"
  27 #include "client.h"
  28
  29 /**
  30  * mei_me_cl_init - initialize me client
  31  *
  32  * @me_cl: me client
  33  */
  34 void mei_me_cl_init(struct mei_me_client *me_cl)
  35 {
  36         INIT_LIST_HEAD(&me_cl->list);
  37         kref_init(&me_cl->refcnt);
  38 }
  39
  40 /**
  41  * mei_me_cl_get - increases me client refcount
  42  *
  43  * @me_cl: me client
  44  *
  45  * Locking: called under "dev->device_lock" lock
  46  *
  47  * Return: me client or NULL
  48  */
  49 struct mei_me_client *mei_me_cl_get(struct mei_me_client *me_cl)
  50 {
  51         if (me_cl && kref_get_unless_zero(&me_cl->refcnt))
  52                 return me_cl;
  53
  54         return NULL;
  55 }
  56
  57 /**
  58  * mei_me_cl_release - free me client
  59  *
  60  * Locking: called under "dev->device_lock" lock
  61  *
  62  * @ref: me_client refcount
  63  */
  64 static void mei_me_cl_release(struct kref *ref)
  65 {
  66         struct mei_me_client *me_cl =
  67                 container_of(ref, struct mei_me_client, refcnt);
  68
  69         kfree(me_cl);
  70 }
  71
  72 /**
  73  * mei_me_cl_put - decrease me client refcount and free client if necessary
  74  *
  75  * Locking: called under "dev->device_lock" lock
  76  *
  77  * @me_cl: me client
  78  */
  79 void mei_me_cl_put(struct mei_me_client *me_cl)
  80 {
  81         if (me_cl)
  82                 kref_put(&me_cl->refcnt, mei_me_cl_release);
  83 }
  84
  85 /**
  86  * __mei_me_cl_del  - delete me client from the list and decrease
  87  *     reference counter
  88  *
  89  * @dev: mei device
  90  * @me_cl: me client
  91  *
  92  * Locking: dev->me_clients_rwsem
  93  */
  94 static void __mei_me_cl_del(struct mei_device *dev, struct mei_me_client *me_cl)
  95 {
  96         if (!me_cl)
  97                 return;
  98
  99         list_del_init(&me_cl->list);
 100         mei_me_cl_put(me_cl);
 101 }
 102
 103 /**
 104  * mei_me_cl_del - delete me client from the list and decrease
 105  *     reference counter
 106  *
 107  * @dev: mei device
 108  * @me_cl: me client
 109  */
 110 void mei_me_cl_del(struct mei_device *dev, struct mei_me_client *me_cl)
 111 {
 112         down_write(&dev->me_clients_rwsem);
 113         __mei_me_cl_del(dev, me_cl);
 114         up_write(&dev->me_clients_rwsem);
 115 }
 116
 117 /**
 118  * mei_me_cl_add - add me client to the list
 119  *
 120  * @dev: mei device
 121  * @me_cl: me client
 122  */
 123 void mei_me_cl_add(struct mei_device *dev, struct mei_me_client *me_cl)
 124 {
 125         down_write(&dev->me_clients_rwsem);
 126         list_add(&me_cl->list, &dev->me_clients);
 127         up_write(&dev->me_clients_rwsem);
 128 }
 129
 130 /**
 131  * __mei_me_cl_by_uuid - locate me client by uuid
 132  *      increases ref count
 133  *
 134  * @dev: mei device
 135  * @uuid: me client uuid
 136  *
 137  * Return: me client or NULL if not found
 138  *
 139  * Locking: dev->me_clients_rwsem
 140  */
 141 static struct mei_me_client *__mei_me_cl_by_uuid(struct mei_device *dev,
 142                                         const uuid_le *uuid)
 143 {
 144         struct mei_me_client *me_cl;
 145         const uuid_le *pn;
 146
 147         WARN_ON(!rwsem_is_locked(&dev->me_clients_rwsem));
 148
 149         list_for_each_entry(me_cl, &dev->me_clients, list) {
 150                 pn = &me_cl->props.protocol_name;
 151                 if (uuid_le_cmp(*uuid, *pn) == 0)
 152                         return mei_me_cl_get(me_cl);
 153         }
 154
 155         return NULL;
 156 }
 157
 158 /**
 159  * mei_me_cl_by_uuid - locate me client by uuid
 160  *      increases ref count
 161  *
 162  * @dev: mei device
 163  * @uuid: me client uuid
 164  *
 165  * Return: me client or NULL if not found
 166  *
 167  * Locking: dev->me_clients_rwsem
 168  */
 169 struct mei_me_client *mei_me_cl_by_uuid(struct mei_device *dev,
 170                                         const uuid_le *uuid)
 171 {
 172         struct mei_me_client *me_cl;
 173
 174         down_read(&dev->me_clients_rwsem);
 175         me_cl = __mei_me_cl_by_uuid(dev, uuid);
 176         up_read(&dev->me_clients_rwsem);
 177
 178         return me_cl;
 179 }
 180
 181 /**
 182  * mei_me_cl_by_id - locate me client by client id
 183  *      increases ref count
 184  *
 185  * @dev: the device structure
 186  * @client_id: me client id
 187  *
 188  * Return: me client or NULL if not found
 189  *
 190  * Locking: dev->me_clients_rwsem
 191  */
 192 struct mei_me_client *mei_me_cl_by_id(struct mei_device *dev, u8 client_id)
 193 {
 194
 195         struct mei_me_client *__me_cl, *me_cl = NULL;
 196
 197         down_read(&dev->me_clients_rwsem);
 198         list_for_each_entry(__me_cl, &dev->me_clients, list) {
 199                 if (__me_cl->client_id == client_id) {
 200                         me_cl = mei_me_cl_get(__me_cl);
 201                         break;
 202                 }
 203         }
 204         up_read(&dev->me_clients_rwsem);
 205
 206         return me_cl;
 207 }
 208
 209 /**
 210  * __mei_me_cl_by_uuid_id - locate me client by client id and uuid
 211  *      increases ref count
 212  *
 213  * @dev: the device structure
 214  * @uuid: me client uuid
 215  * @client_id: me client id
 216  *
 217  * Return: me client or null if not found
 218  *
 219  * Locking: dev->me_clients_rwsem
 220  */
 221 static struct mei_me_client *__mei_me_cl_by_uuid_id(struct mei_device *dev,
 222                                            const uuid_le *uuid, u8 client_id)
 223 {
 224         struct mei_me_client *me_cl;
 225         const uuid_le *pn;
 226
 227         WARN_ON(!rwsem_is_locked(&dev->me_clients_rwsem));
 228
 229         list_for_each_entry(me_cl, &dev->me_clients, list) {
 230                 pn = &me_cl->props.protocol_name;
 231                 if (uuid_le_cmp(*uuid, *pn) == 0 &&
 232                     me_cl->client_id == client_id)
 233                         return mei_me_cl_get(me_cl);
 234         }
 235
 236         return NULL;
 237 }
 238
 239
 240 /**
 241  * mei_me_cl_by_uuid_id - locate me client by client id and uuid
 242  *      increases ref count
 243  *
 244  * @dev: the device structure
 245  * @uuid: me client uuid
 246  * @client_id: me client id
 247  *
 248  * Return: me client or null if not found
 249  */
 250 struct mei_me_client *mei_me_cl_by_uuid_id(struct mei_device *dev,
 251                                            const uuid_le *uuid, u8 client_id)
 252 {
 253         struct mei_me_client *me_cl;
 254
 255         down_read(&dev->me_clients_rwsem);
 256         me_cl = __mei_me_cl_by_uuid_id(dev, uuid, client_id);
 257         up_read(&dev->me_clients_rwsem);
 258
 259         return me_cl;
 260 }
 261
 262 /**
 263  * mei_me_cl_rm_by_uuid - remove all me clients matching uuid
 264  *
 265  * @dev: the device structure
 266  * @uuid: me client uuid
 267  *
 268  * Locking: called under "dev->device_lock" lock
 269  */
 270 void mei_me_cl_rm_by_uuid(struct mei_device *dev, const uuid_le *uuid)
 271 {
 272         struct mei_me_client *me_cl;
 273
 274         dev_dbg(dev->dev, "remove %pUl\n", uuid);
 275
 276         down_write(&dev->me_clients_rwsem);
 277         me_cl = __mei_me_cl_by_uuid(dev, uuid);
 278         __mei_me_cl_del(dev, me_cl);
 279         up_write(&dev->me_clients_rwsem);
 280 }
 281
 282 /**
 283  * mei_me_cl_rm_by_uuid_id - remove all me clients matching client id
 284  *
 285  * @dev: the device structure
 286  * @uuid: me client uuid
 287  * @id: me client id
 288  *
 289  * Locking: called under "dev->device_lock" lock
 290  */
 291 void mei_me_cl_rm_by_uuid_id(struct mei_device *dev, const uuid_le *uuid, u8 id)
 292 {
 293         struct mei_me_client *me_cl;
 294
 295         dev_dbg(dev->dev, "remove %pUl %d\n", uuid, id);
 296
 297         down_write(&dev->me_clients_rwsem);
 298         me_cl = __mei_me_cl_by_uuid_id(dev, uuid, id);
 299         __mei_me_cl_del(dev, me_cl);
 300         up_write(&dev->me_clients_rwsem);
 301 }
 302
 303 /**
 304  * mei_me_cl_rm_all - remove all me clients
 305  *
 306  * @dev: the device structure
 307  *
 308  * Locking: called under "dev->device_lock" lock
 309  */
 310 void mei_me_cl_rm_all(struct mei_device *dev)
 311 {
 312         struct mei_me_client *me_cl, *next;
 313
 314         down_write(&dev->me_clients_rwsem);
 315         list_for_each_entry_safe(me_cl, next, &dev->me_clients, list)
 316                 __mei_me_cl_del(dev, me_cl);
 317         up_write(&dev->me_clients_rwsem);
 318 }
 319
 320 /**
 321  * mei_io_cb_free - free mei_cb_private related memory
 322  *
 323  * @cb: mei callback struct
 324  */
 325 void mei_io_cb_free(struct mei_cl_cb *cb)
 326 {
 327         if (cb == NULL)
 328                 return;
 329
 330         list_del(&cb->list);
 331         kfree(cb->buf.data);
 332         kfree(cb);
 333 }
 334
 335 /**
 336  * mei_tx_cb_queue - queue tx callback
 337  *
 338  * Locking: called under "dev->device_lock" lock
 339  *
 340  * @cb: mei callback struct
 341  * @head: an instance of list to queue on
 342  */
 343 static inline void mei_tx_cb_enqueue(struct mei_cl_cb *cb,
 344                                      struct list_head *head)
 345 {
 346         list_add_tail(&cb->list, head);
 347         cb->cl->tx_cb_queued++;
 348 }
 349
 350 /**
 351  * mei_tx_cb_dequeue - dequeue tx callback
 352  *
 353  * Locking: called under "dev->device_lock" lock
 354  *
 355  * @cb: mei callback struct to dequeue and free
 356  */
 357 static inline void mei_tx_cb_dequeue(struct mei_cl_cb *cb)
 358 {
 359         if (!WARN_ON(cb->cl->tx_cb_queued == 0))
 360                 cb->cl->tx_cb_queued--;
 361
 362         mei_io_cb_free(cb);
 363 }
 364
 365 /**
 366  * mei_io_cb_init - allocate and initialize io callback
 367  *
 368  * @cl: mei client
 369  * @type: operation type
 370  * @fp: pointer to file structure
 371  *
 372  * Return: mei_cl_cb pointer or NULL;
 373  */
 374 static struct mei_cl_cb *mei_io_cb_init(struct mei_cl *cl,
 375                                         enum mei_cb_file_ops type,
 376                                         const struct file *fp)
 377 {
 378         struct mei_cl_cb *cb;
 379
 380         cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
 381         if (!cb)
 382                 return NULL;
 383
 384         INIT_LIST_HEAD(&cb->list);
 385         cb->fp = fp;
 386         cb->cl = cl;
 387         cb->buf_idx = 0;
 388         cb->fop_type = type;
 389         return cb;
 390 }
 391
 392 /**
 393  * mei_io_list_flush_cl - removes cbs belonging to the cl.
 394  *
 395  * @head:  an instance of our list structure
 396  * @cl:    host client
 397  */
 398 static void mei_io_list_flush_cl(struct list_head *head,
 399                                  const struct mei_cl *cl)
 400 {
 401         struct mei_cl_cb *cb, *next;
 402
 403         list_for_each_entry_safe(cb, next, head, list) {
 404                 if (cl == cb->cl)
 405                         list_del_init(&cb->list);
 406         }
 407 }
 408
 409 /**
 410  * mei_io_tx_list_free_cl - removes cb belonging to the cl and free them
 411  *
 412  * @head: An instance of our list structure
 413  * @cl: host client
 414  */
 415 static void mei_io_tx_list_free_cl(struct list_head *head,
 416                                    const struct mei_cl *cl)
 417 {
 418         struct mei_cl_cb *cb, *next;
 419
 420         list_for_each_entry_safe(cb, next, head, list) {
 421                 if (cl == cb->cl)
 422                         mei_tx_cb_dequeue(cb);
 423         }
 424 }
 425
 426 /**
 427  * mei_io_list_free_fp - free cb from a list that matches file pointer
 428  *
 429  * @head: io list
 430  * @fp: file pointer (matching cb file object), may be NULL
 431  */
 432 static void mei_io_list_free_fp(struct list_head *head, const struct file *fp)
 433 {
 434         struct mei_cl_cb *cb, *next;
 435
 436         list_for_each_entry_safe(cb, next, head, list)
 437                 if (!fp || fp == cb->fp)
 438                         mei_io_cb_free(cb);
 439 }
 440
 441 /**
 442  * mei_cl_alloc_cb - a convenient wrapper for allocating read cb
 443  *
 444  * @cl: host client
 445  * @length: size of the buffer
 446  * @fop_type: operation type
 447  * @fp: associated file pointer (might be NULL)
 448  *
 449  * Return: cb on success and NULL on failure
 450  */
 451 struct mei_cl_cb *mei_cl_alloc_cb(struct mei_cl *cl, size_t length,
 452                                   enum mei_cb_file_ops fop_type,
 453                                   const struct file *fp)
 454 {
 455         struct mei_cl_cb *cb;
 456
 457         cb = mei_io_cb_init(cl, fop_type, fp);
 458         if (!cb)
 459                 return NULL;
 460
 461         if (length == 0)
 462                 return cb;
 463
 464         cb->buf.data = kmalloc(roundup(length, MEI_SLOT_SIZE), GFP_KERNEL);
 465         if (!cb->buf.data) {
 466                 mei_io_cb_free(cb);
 467                 return NULL;
 468         }
 469         cb->buf.size = length;
 470
 471         return cb;
 472 }
 473
 474 /**
 475  * mei_cl_enqueue_ctrl_wr_cb - a convenient wrapper for allocating
 476  *     and enqueuing of the control commands cb
 477  *
 478  * @cl: host client
 479  * @length: size of the buffer
 480  * @fop_type: operation type
 481  * @fp: associated file pointer (might be NULL)
 482  *
 483  * Return: cb on success and NULL on failure
 484  * Locking: called under "dev->device_lock" lock
 485  */
 486 struct mei_cl_cb *mei_cl_enqueue_ctrl_wr_cb(struct mei_cl *cl, size_t length,
 487                                             enum mei_cb_file_ops fop_type,
 488                                             const struct file *fp)
 489 {
 490         struct mei_cl_cb *cb;
 491
 492         /* for RX always allocate at least client's mtu */
 493         if (length)
 494                 length = max_t(size_t, length, mei_cl_mtu(cl));
 495
 496         cb = mei_cl_alloc_cb(cl, length, fop_type, fp);
 497         if (!cb)
 498                 return NULL;
 499
 500         list_add_tail(&cb->list, &cl->dev->ctrl_wr_list);
 501         return cb;
 502 }
 503
 504 /**
 505  * mei_cl_read_cb - find this cl's callback in the read list
 506  *     for a specific file
 507  *
 508  * @cl: host client
 509  * @fp: file pointer (matching cb file object), may be NULL
 510  *
 511  * Return: cb on success, NULL if cb is not found
 512  */
 513 struct mei_cl_cb *mei_cl_read_cb(const struct mei_cl *cl, const struct file *fp)
 514 {
 515         struct mei_cl_cb *cb;
 516
 517         list_for_each_entry(cb, &cl->rd_completed, list)
 518                 if (!fp || fp == cb->fp)
 519                         return cb;
 520
 521         return NULL;
 522 }
 523
 524 /**
 525  * mei_cl_flush_queues - flushes queue lists belonging to cl.
 526  *
 527  * @cl: host client
 528  * @fp: file pointer (matching cb file object), may be NULL
 529  *
 530  * Return: 0 on success, -EINVAL if cl or cl->dev is NULL.
 531  */
 532 int mei_cl_flush_queues(struct mei_cl *cl, const struct file *fp)
 533 {
 534         struct mei_device *dev;
 535
 536         if (WARN_ON(!cl || !cl->dev))
 537                 return -EINVAL;
 538
 539         dev = cl->dev;
 540
 541         cl_dbg(dev, cl, "remove list entry belonging to cl\n");
 542         mei_io_tx_list_free_cl(&cl->dev->write_list, cl);
 543         mei_io_tx_list_free_cl(&cl->dev->write_waiting_list, cl);
 544         mei_io_list_flush_cl(&cl->dev->ctrl_wr_list, cl);
 545         mei_io_list_flush_cl(&cl->dev->ctrl_rd_list, cl);
 546         mei_io_list_free_fp(&cl->rd_pending, fp);
 547         mei_io_list_free_fp(&cl->rd_completed, fp);
 548
 549         return 0;
 550 }
 551
 552 /**
 553  * mei_cl_init - initializes cl.
 554  *
 555  * @cl: host client to be initialized
 556  * @dev: mei device
 557  */
 558 static void mei_cl_init(struct mei_cl *cl, struct mei_device *dev)
 559 {
 560         memset(cl, 0, sizeof(struct mei_cl));
 561         init_waitqueue_head(&cl->wait);
 562         init_waitqueue_head(&cl->rx_wait);
 563         init_waitqueue_head(&cl->tx_wait);
 564         init_waitqueue_head(&cl->ev_wait);
 565         INIT_LIST_HEAD(&cl->rd_completed);
 566         INIT_LIST_HEAD(&cl->rd_pending);
 567         INIT_LIST_HEAD(&cl->link);
 568         cl->writing_state = MEI_IDLE;
 569         cl->state = MEI_FILE_UNINITIALIZED;
 570         cl->dev = dev;
 571 }
 572
 573 /**
 574  * mei_cl_allocate - allocates cl  structure and sets it up.
 575  *
 576  * @dev: mei device
 577  * Return:  The allocated file or NULL on failure
 578  */
 579 struct mei_cl *mei_cl_allocate(struct mei_device *dev)
 580 {
 581         struct mei_cl *cl;
 582
 583         cl = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
 584         if (!cl)
 585                 return NULL;
 586
 587         mei_cl_init(cl, dev);
 588
 589         return cl;
 590 }
 591
 592 /**
 593  * mei_cl_link - allocate host id in the host map
 594  *
 595  * @cl: host client
 596  *
 597  * Return: 0 on success
 598  *      -EINVAL on incorrect values
 599  *      -EMFILE if open count exceeded.
 600  */
 601 int mei_cl_link(struct mei_cl *cl)
 602 {
 603         struct mei_device *dev;
 604         int id;
 605
 606         if (WARN_ON(!cl || !cl->dev))
 607                 return -EINVAL;
 608
 609         dev = cl->dev;
 610
 611         id = find_first_zero_bit(dev->host_clients_map, MEI_CLIENTS_MAX);
 612         if (id >= MEI_CLIENTS_MAX) {
 613                 dev_err(dev->dev, "id exceeded %d", MEI_CLIENTS_MAX);
 614                 return -EMFILE;
 615         }
 616
 617         if (dev->open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
 618                 dev_err(dev->dev, "open_handle_count exceeded %d",
 619                         MEI_MAX_OPEN_HANDLE_COUNT);
 620                 return -EMFILE;
 621         }
 622
 623         dev->open_handle_count++;
 624
 625         cl->host_client_id = id;
 626         list_add_tail(&cl->link, &dev->file_list);
 627
 628         set_bit(id, dev->host_clients_map);
 629
 630         cl->state = MEI_FILE_INITIALIZING;
 631
 632         cl_dbg(dev, cl, "link cl\n");
 633         return 0;
 634 }
 635
 636 /**
 637  * mei_cl_unlink - remove host client from the list
 638  *
 639  * @cl: host client
 640  *
 641  * Return: always 0
 642  */
 643 int mei_cl_unlink(struct mei_cl *cl)
 644 {
 645         struct mei_device *dev;
 646
 647         /* don't shout on error exit path */
 648         if (!cl)
 649                 return 0;
 650
 651         if (WARN_ON(!cl->dev))
 652                 return 0;
 653
 654         dev = cl->dev;
 655
 656         cl_dbg(dev, cl, "unlink client");
 657
 658         if (dev->open_handle_count > 0)
 659                 dev->open_handle_count--;
 660
 661         /* never clear the 0 bit */
 662         if (cl->host_client_id)
 663                 clear_bit(cl->host_client_id, dev->host_clients_map);
 664
 665         list_del_init(&cl->link);
 666
 667         cl->state = MEI_FILE_UNINITIALIZED;
 668         cl->writing_state = MEI_IDLE;
 669
 670         WARN_ON(!list_empty(&cl->rd_completed) ||
 671                 !list_empty(&cl->rd_pending) ||
 672                 !list_empty(&cl->link));
 673
 674         return 0;
 675 }
 676
 677 void mei_host_client_init(struct mei_device *dev)
 678 {
 679         dev->dev_state = MEI_DEV_ENABLED;
 680         dev->reset_count = 0;
 681
 682         schedule_work(&dev->bus_rescan_work);
 683
 684         pm_runtime_mark_last_busy(dev->dev);
 685         dev_dbg(dev->dev, "rpm: autosuspend\n");
 686         pm_request_autosuspend(dev->dev);
 687 }
 688
 689 /**
 690  * mei_hbuf_acquire - try to acquire host buffer
 691  *
 692  * @dev: the device structure
 693  * Return: true if host buffer was acquired
 694  */
 695 bool mei_hbuf_acquire(struct mei_device *dev)
 696 {
 697         if (mei_pg_state(dev) == MEI_PG_ON ||
 698             mei_pg_in_transition(dev)) {
 699                 dev_dbg(dev->dev, "device is in pg\n");
 700                 return false;
 701         }
 702
 703         if (!dev->hbuf_is_ready) {
 704                 dev_dbg(dev->dev, "hbuf is not ready\n");
 705                 return false;
 706         }
 707
 708         dev->hbuf_is_ready = false;
 709
 710         return true;
 711 }
 712
 713 /**
 714  * mei_cl_wake_all - wake up readers, writers and event waiters so
 715  *                 they can be interrupted
 716  *
 717  * @cl: host client
 718  */
 719 static void mei_cl_wake_all(struct mei_cl *cl)
 720 {
 721         struct mei_device *dev = cl->dev;
 722
 723         /* synchronized under device mutex */
 724         if (waitqueue_active(&cl->rx_wait)) {
 725                 cl_dbg(dev, cl, "Waking up reading client!\n");
 726                 wake_up_interruptible(&cl->rx_wait);
 727         }
 728         /* synchronized under device mutex */
 729         if (waitqueue_active(&cl->tx_wait)) {
 730                 cl_dbg(dev, cl, "Waking up writing client!\n");
 731                 wake_up_interruptible(&cl->tx_wait);
 732         }
 733         /* synchronized under device mutex */
 734         if (waitqueue_active(&cl->ev_wait)) {
 735                 cl_dbg(dev, cl, "Waking up waiting for event clients!\n");
 736                 wake_up_interruptible(&cl->ev_wait);
 737         }
 738         /* synchronized under device mutex */
 739         if (waitqueue_active(&cl->wait)) {
 740                 cl_dbg(dev, cl, "Waking up ctrl write clients!\n");
 741                 wake_up(&cl->wait);
 742         }
 743 }
 744
 745 /**
 746  * mei_cl_set_disconnected - set disconnected state and clear
 747  *   associated states and resources
 748  *
 749  * @cl: host client
 750  */
 751 static void mei_cl_set_disconnected(struct mei_cl *cl)
 752 {
 753         struct mei_device *dev = cl->dev;
 754
 755         if (cl->state == MEI_FILE_DISCONNECTED ||
 756             cl->state <= MEI_FILE_INITIALIZING)
 757                 return;
 758
 759         cl->state = MEI_FILE_DISCONNECTED;
 760         mei_io_tx_list_free_cl(&dev->write_list, cl);
 761         mei_io_tx_list_free_cl(&dev->write_waiting_list, cl);
 762         mei_io_list_flush_cl(&dev->ctrl_rd_list, cl);
 763         mei_io_list_flush_cl(&dev->ctrl_wr_list, cl);
 764         mei_cl_wake_all(cl);
 765         cl->rx_flow_ctrl_creds = 0;
 766         cl->tx_flow_ctrl_creds = 0;
 767         cl->timer_count = 0;
 768
 769         if (!cl->me_cl)
 770                 return;
 771
 772         if (!WARN_ON(cl->me_cl->connect_count == 0))
 773                 cl->me_cl->connect_count--;
 774
 775         if (cl->me_cl->connect_count == 0)
 776                 cl->me_cl->tx_flow_ctrl_creds = 0;
 777
 778         mei_me_cl_put(cl->me_cl);
 779         cl->me_cl = NULL;
 780 }
 781
 782 static int mei_cl_set_connecting(struct mei_cl *cl, struct mei_me_client *me_cl)
 783 {
 784         if (!mei_me_cl_get(me_cl))
 785                 return -ENOENT;
 786
 787         /* only one connection is allowed for fixed address clients */
 788         if (me_cl->props.fixed_address) {
 789                 if (me_cl->connect_count) {
 790                         mei_me_cl_put(me_cl);
 791                         return -EBUSY;
 792                 }
 793         }
 794
 795         cl->me_cl = me_cl;
 796         cl->state = MEI_FILE_CONNECTING;
 797         cl->me_cl->connect_count++;
 798
 799         return 0;
 800 }
 801
 802 /*
 803  * mei_cl_send_disconnect - send disconnect request
 804  *
 805  * @cl: host client
 806  * @cb: callback block
 807  *
 808  * Return: 0, OK; otherwise, error.
 809  */
 810 static int mei_cl_send_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb)
 811 {
 812         struct mei_device *dev;
 813         int ret;
 814
 815         dev = cl->dev;
 816
 817         ret = mei_hbm_cl_disconnect_req(dev, cl);
 818         cl->status = ret;
 819         if (ret) {
 820                 cl->state = MEI_FILE_DISCONNECT_REPLY;
 821                 return ret;
 822         }
 823
 824         list_move_tail(&cb->list, &dev->ctrl_rd_list);
 825         cl->timer_count = MEI_CONNECT_TIMEOUT;
 826         mei_schedule_stall_timer(dev);
 827
 828         return 0;
 829 }
 830
 831 /**
 832  * mei_cl_irq_disconnect - processes close related operation from
 833  *      interrupt thread context - send disconnect request
 834  *
 835  * @cl: client
 836  * @cb: callback block.
 837  * @cmpl_list: complete list.
 838  *
 839  * Return: 0, OK; otherwise, error.
 840  */
 841 int mei_cl_irq_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb,
 842                           struct list_head *cmpl_list)
 843 {
 844         struct mei_device *dev = cl->dev;
 845         u32 msg_slots;
 846         int slots;
 847         int ret;
 848
 849         msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_request));
 850         slots = mei_hbuf_empty_slots(dev);
 851         if (slots < 0)
 852                 return -EOVERFLOW;
 853
 854         if ((u32)slots < msg_slots)
 855                 return -EMSGSIZE;
 856
 857         ret = mei_cl_send_disconnect(cl, cb);
 858         if (ret)
 859                 list_move_tail(&cb->list, cmpl_list);
 860
 861         return ret;
 862 }
 863
 864 /**
 865  * __mei_cl_disconnect - disconnect host client from the me one
 866  *     internal function runtime pm has to be already acquired
 867  *
 868  * @cl: host client
 869  *
 870  * Return: 0 on success, <0 on failure.
 871  */
 872 static int __mei_cl_disconnect(struct mei_cl *cl)
 873 {
 874         struct mei_device *dev;
 875         struct mei_cl_cb *cb;
 876         int rets;
 877
 878         dev = cl->dev;
 879
 880         cl->state = MEI_FILE_DISCONNECTING;
 881
 882         cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_DISCONNECT, NULL);
 883         if (!cb) {
 884                 rets = -ENOMEM;
 885                 goto out;
 886         }
 887
 888         if (mei_hbuf_acquire(dev)) {
 889                 rets = mei_cl_send_disconnect(cl, cb);
 890                 if (rets) {
 891                         cl_err(dev, cl, "failed to disconnect.\n");
 892                         goto out;
 893                 }
 894         }
 895
 896         mutex_unlock(&dev->device_lock);
 897         wait_event_timeout(cl->wait,
 898                            cl->state == MEI_FILE_DISCONNECT_REPLY ||
 899                            cl->state == MEI_FILE_DISCONNECTED,
 900                            mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 901         mutex_lock(&dev->device_lock);
 902
 903         rets = cl->status;
 904         if (cl->state != MEI_FILE_DISCONNECT_REPLY &&
 905             cl->state != MEI_FILE_DISCONNECTED) {
 906                 cl_dbg(dev, cl, "timeout on disconnect from FW client.\n");
 907                 rets = -ETIME;
 908         }
 909
 910 out:
 911         /* we disconnect also on error */
 912         mei_cl_set_disconnected(cl);
 913         if (!rets)
 914                 cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
 915
 916         mei_io_cb_free(cb);
 917         return rets;
 918 }
 919
 920 /**
 921  * mei_cl_disconnect - disconnect host client from the me one
 922  *
 923  * @cl: host client
 924  *
 925  * Locking: called under "dev->device_lock" lock
 926  *
 927  * Return: 0 on success, <0 on failure.
 928  */
 929 int mei_cl_disconnect(struct mei_cl *cl)
 930 {
 931         struct mei_device *dev;
 932         int rets;
 933
 934         if (WARN_ON(!cl || !cl->dev))
 935                 return -ENODEV;
 936
 937         dev = cl->dev;
 938
 939         cl_dbg(dev, cl, "disconnecting");
 940
 941         if (!mei_cl_is_connected(cl))
 942                 return 0;
 943
 944         if (mei_cl_is_fixed_address(cl)) {
 945                 mei_cl_set_disconnected(cl);
 946                 return 0;
 947         }
 948
 949         if (dev->dev_state == MEI_DEV_POWER_DOWN) {
 950                 cl_dbg(dev, cl, "Device is powering down, don't bother with disconnection\n");
 951                 mei_cl_set_disconnected(cl);
 952                 return 0;
 953         }
 954
 955         rets = pm_runtime_get(dev->dev);
 956         if (rets < 0 && rets != -EINPROGRESS) {
 957                 pm_runtime_put_noidle(dev->dev);
 958                 cl_err(dev, cl, "rpm: get failed %d\n", rets);
 959                 return rets;
 960         }
 961
 962         rets = __mei_cl_disconnect(cl);
 963
 964         cl_dbg(dev, cl, "rpm: autosuspend\n");
 965         pm_runtime_mark_last_busy(dev->dev);
 966         pm_runtime_put_autosuspend(dev->dev);
 967
 968         return rets;
 969 }
 970
 971
 972 /**
 973  * mei_cl_is_other_connecting - checks if other
 974  *    client with the same me client id is connecting
 975  *
 976  * @cl: private data of the file object
 977  *
 978  * Return: true if other client is connected, false - otherwise.
 979  */
 980 static bool mei_cl_is_other_connecting(struct mei_cl *cl)
 981 {
 982         struct mei_device *dev;
 983         struct mei_cl_cb *cb;
 984
 985         dev = cl->dev;
 986
 987         list_for_each_entry(cb, &dev->ctrl_rd_list, list) {
 988                 if (cb->fop_type == MEI_FOP_CONNECT &&
 989                     mei_cl_me_id(cl) == mei_cl_me_id(cb->cl))
 990                         return true;
 991         }
 992
 993         return false;
 994 }
 995
 996 /**
 997  * mei_cl_send_connect - send connect request
 998  *
 999  * @cl: host client
1000  * @cb: callback block
1001  *
1002  * Return: 0, OK; otherwise, error.
1003  */
1004 static int mei_cl_send_connect(struct mei_cl *cl, struct mei_cl_cb *cb)
1005 {
1006         struct mei_device *dev;
1007         int ret;
1008
1009         dev = cl->dev;
1010
1011         ret = mei_hbm_cl_connect_req(dev, cl);
1012         cl->status = ret;
1013         if (ret) {
1014                 cl->state = MEI_FILE_DISCONNECT_REPLY;
1015                 return ret;
1016         }
1017
1018         list_move_tail(&cb->list, &dev->ctrl_rd_list);
1019         cl->timer_count = MEI_CONNECT_TIMEOUT;
1020         mei_schedule_stall_timer(dev);
1021         return 0;
1022 }
1023
1024 /**
1025  * mei_cl_irq_connect - send connect request in irq_thread context
1026  *
1027  * @cl: host client
1028  * @cb: callback block
1029  * @cmpl_list: complete list
1030  *
1031  * Return: 0, OK; otherwise, error.
1032  */
1033 int mei_cl_irq_connect(struct mei_cl *cl, struct mei_cl_cb *cb,
1034                        struct list_head *cmpl_list)
1035 {
1036         struct mei_device *dev = cl->dev;
1037         u32 msg_slots;
1038         int slots;
1039         int rets;
1040
1041         if (mei_cl_is_other_connecting(cl))
1042                 return 0;
1043
1044         msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_request));
1045         slots = mei_hbuf_empty_slots(dev);
1046         if (slots < 0)
1047                 return -EOVERFLOW;
1048
1049         if ((u32)slots < msg_slots)
1050                 return -EMSGSIZE;
1051
1052         rets = mei_cl_send_connect(cl, cb);
1053         if (rets)
1054                 list_move_tail(&cb->list, cmpl_list);
1055
1056         return rets;
1057 }
1058
1059 /**
1060  * mei_cl_connect - connect host client to the me one
1061  *
1062  * @cl: host client
1063  * @me_cl: me client
1064  * @fp: pointer to file structure
1065  *
1066  * Locking: called under "dev->device_lock" lock
1067  *
1068  * Return: 0 on success, <0 on failure.
1069  */
1070 int mei_cl_connect(struct mei_cl *cl, struct mei_me_client *me_cl,
1071                    const struct file *fp)
1072 {
1073         struct mei_device *dev;
1074         struct mei_cl_cb *cb;
1075         int rets;
1076
1077         if (WARN_ON(!cl || !cl->dev || !me_cl))
1078                 return -ENODEV;
1079
1080         dev = cl->dev;
1081
1082         rets = mei_cl_set_connecting(cl, me_cl);
1083         if (rets)
1084                 goto nortpm;
1085
1086         if (mei_cl_is_fixed_address(cl)) {
1087                 cl->state = MEI_FILE_CONNECTED;
1088                 rets = 0;
1089                 goto nortpm;
1090         }
1091
1092         rets = pm_runtime_get(dev->dev);
1093         if (rets < 0 && rets != -EINPROGRESS) {
1094                 pm_runtime_put_noidle(dev->dev);
1095                 cl_err(dev, cl, "rpm: get failed %d\n", rets);
1096                 goto nortpm;
1097         }
1098
1099         cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_CONNECT, fp);
1100         if (!cb) {
1101                 rets = -ENOMEM;
1102                 goto out;
1103         }
1104
1105         /* run hbuf acquire last so we don't have to undo */
1106         if (!mei_cl_is_other_connecting(cl) && mei_hbuf_acquire(dev)) {
1107                 rets = mei_cl_send_connect(cl, cb);
1108                 if (rets)
1109                         goto out;
1110         }
1111
1112         mutex_unlock(&dev->device_lock);
1113         wait_event_timeout(cl->wait,
1114                         (cl->state == MEI_FILE_CONNECTED ||
1115                          cl->state == MEI_FILE_DISCONNECTED ||
1116                          cl->state == MEI_FILE_DISCONNECT_REQUIRED ||
1117                          cl->state == MEI_FILE_DISCONNECT_REPLY),
1118                         mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1119         mutex_lock(&dev->device_lock);
1120
1121         if (!mei_cl_is_connected(cl)) {
1122                 if (cl->state == MEI_FILE_DISCONNECT_REQUIRED) {
1123                         mei_io_list_flush_cl(&dev->ctrl_rd_list, cl);
1124                         mei_io_list_flush_cl(&dev->ctrl_wr_list, cl);
1125                          /* ignore disconnect return valuue;
1126                           * in case of failure reset will be invoked
1127                           */
1128                         __mei_cl_disconnect(cl);
1129                         rets = -EFAULT;
1130                         goto out;
1131                 }
1132
1133                 /* timeout or something went really wrong */
1134                 if (!cl->status)
1135                         cl->status = -EFAULT;
1136         }
1137
1138         rets = cl->status;
1139 out:
1140         cl_dbg(dev, cl, "rpm: autosuspend\n");
1141         pm_runtime_mark_last_busy(dev->dev);
1142         pm_runtime_put_autosuspend(dev->dev);
1143
1144         mei_io_cb_free(cb);
1145
1146 nortpm:
1147         if (!mei_cl_is_connected(cl))
1148                 mei_cl_set_disconnected(cl);
1149
1150         return rets;
1151 }
1152
1153 /**
1154  * mei_cl_alloc_linked - allocate and link host client
1155  *
1156  * @dev: the device structure
1157  *
1158  * Return: cl on success ERR_PTR on failure
1159  */
1160 struct mei_cl *mei_cl_alloc_linked(struct mei_device *dev)
1161 {
1162         struct mei_cl *cl;
1163         int ret;
1164
1165         cl = mei_cl_allocate(dev);
1166         if (!cl) {
1167                 ret = -ENOMEM;
1168                 goto err;
1169         }
1170
1171         ret = mei_cl_link(cl);
1172         if (ret)
1173                 goto err;
1174
1175         return cl;
1176 err:
1177         kfree(cl);
1178         return ERR_PTR(ret);
1179 }
1180
1181 /**
1182  * mei_cl_tx_flow_ctrl_creds - checks flow_control credits for cl.
1183  *
1184  * @cl: host client
1185  *
1186  * Return: 1 if tx_flow_ctrl_creds >0, 0 - otherwise.
1187  */
1188 static int mei_cl_tx_flow_ctrl_creds(struct mei_cl *cl)
1189 {
1190         if (WARN_ON(!cl || !cl->me_cl))
1191                 return -EINVAL;
1192
1193         if (cl->tx_flow_ctrl_creds > 0)
1194                 return 1;
1195
1196         if (mei_cl_is_fixed_address(cl))
1197                 return 1;
1198
1199         if (mei_cl_is_single_recv_buf(cl)) {
1200                 if (cl->me_cl->tx_flow_ctrl_creds > 0)
1201                         return 1;
1202         }
1203         return 0;
1204 }
1205
1206 /**
1207  * mei_cl_tx_flow_ctrl_creds_reduce - reduces transmit flow control credits
1208  *   for a client
1209  *
1210  * @cl: host client
1211  *
1212  * Return:
1213  *      0 on success
1214  *      -EINVAL when ctrl credits are <= 0
1215  */
1216 static int mei_cl_tx_flow_ctrl_creds_reduce(struct mei_cl *cl)
1217 {
1218         if (WARN_ON(!cl || !cl->me_cl))
1219                 return -EINVAL;
1220
1221         if (mei_cl_is_fixed_address(cl))
1222                 return 0;
1223
1224         if (mei_cl_is_single_recv_buf(cl)) {
1225                 if (WARN_ON(cl->me_cl->tx_flow_ctrl_creds <= 0))
1226                         return -EINVAL;
1227                 cl->me_cl->tx_flow_ctrl_creds--;
1228         } else {
1229                 if (WARN_ON(cl->tx_flow_ctrl_creds <= 0))
1230                         return -EINVAL;
1231                 cl->tx_flow_ctrl_creds--;
1232         }
1233         return 0;
1234 }
1235
1236 /**
1237  *  mei_cl_notify_fop2req - convert fop to proper request
1238  *
1239  * @fop: client notification start response command
1240  *
1241  * Return:  MEI_HBM_NOTIFICATION_START/STOP
1242  */
1243 u8 mei_cl_notify_fop2req(enum mei_cb_file_ops fop)
1244 {
1245         if (fop == MEI_FOP_NOTIFY_START)
1246                 return MEI_HBM_NOTIFICATION_START;
1247         else
1248                 return MEI_HBM_NOTIFICATION_STOP;
1249 }
1250
1251 /**
1252  *  mei_cl_notify_req2fop - convert notification request top file operation type
1253  *
1254  * @req: hbm notification request type
1255  *
1256  * Return:  MEI_FOP_NOTIFY_START/STOP
1257  */
1258 enum mei_cb_file_ops mei_cl_notify_req2fop(u8 req)
1259 {
1260         if (req == MEI_HBM_NOTIFICATION_START)
1261                 return MEI_FOP_NOTIFY_START;
1262         else
1263                 return MEI_FOP_NOTIFY_STOP;
1264 }
1265
1266 /**
1267  * mei_cl_irq_notify - send notification request in irq_thread context
1268  *
1269  * @cl: client
1270  * @cb: callback block.
1271  * @cmpl_list: complete list.
1272  *
1273  * Return: 0 on such and error otherwise.
1274  */
1275 int mei_cl_irq_notify(struct mei_cl *cl, struct mei_cl_cb *cb,
1276                       struct list_head *cmpl_list)
1277 {
1278         struct mei_device *dev = cl->dev;
1279         u32 msg_slots;
1280         int slots;
1281         int ret;
1282         bool request;
1283
1284         msg_slots = mei_hbm2slots(sizeof(struct hbm_client_connect_request));
1285         slots = mei_hbuf_empty_slots(dev);
1286         if (slots < 0)
1287                 return -EOVERFLOW;
1288
1289         if ((u32)slots < msg_slots)
1290                 return -EMSGSIZE;
1291
1292         request = mei_cl_notify_fop2req(cb->fop_type);
1293         ret = mei_hbm_cl_notify_req(dev, cl, request);
1294         if (ret) {
1295                 cl->status = ret;
1296                 list_move_tail(&cb->list, cmpl_list);
1297                 return ret;
1298         }
1299
1300         list_move_tail(&cb->list, &dev->ctrl_rd_list);
1301         return 0;
1302 }
1303
1304 /**
1305  * mei_cl_notify_request - send notification stop/start request
1306  *
1307  * @cl: host client
1308  * @fp: associate request with file
1309  * @request: 1 for start or 0 for stop
1310  *
1311  * Locking: called under "dev->device_lock" lock
1312  *
1313  * Return: 0 on such and error otherwise.
1314  */
1315 int mei_cl_notify_request(struct mei_cl *cl,
1316                           const struct file *fp, u8 request)
1317 {
1318         struct mei_device *dev;
1319         struct mei_cl_cb *cb;
1320         enum mei_cb_file_ops fop_type;
1321         int rets;
1322
1323         if (WARN_ON(!cl || !cl->dev))
1324                 return -ENODEV;
1325
1326         dev = cl->dev;
1327
1328         if (!dev->hbm_f_ev_supported) {
1329                 cl_dbg(dev, cl, "notifications not supported\n");
1330                 return -EOPNOTSUPP;
1331         }
1332
1333         if (!mei_cl_is_connected(cl))
1334                 return -ENODEV;
1335
1336         rets = pm_runtime_get(dev->dev);
1337         if (rets < 0 && rets != -EINPROGRESS) {
1338                 pm_runtime_put_noidle(dev->dev);
1339                 cl_err(dev, cl, "rpm: get failed %d\n", rets);
1340                 return rets;
1341         }
1342
1343         fop_type = mei_cl_notify_req2fop(request);
1344         cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, fop_type, fp);
1345         if (!cb) {
1346                 rets = -ENOMEM;
1347                 goto out;
1348         }
1349
1350         if (mei_hbuf_acquire(dev)) {
1351                 if (mei_hbm_cl_notify_req(dev, cl, request)) {
1352                         rets = -ENODEV;
1353                         goto out;
1354                 }
1355                 list_move_tail(&cb->list, &dev->ctrl_rd_list);
1356         }
1357
1358         mutex_unlock(&dev->device_lock);
1359         wait_event_timeout(cl->wait,
1360                            cl->notify_en == request ||
1361                            cl->status ||
1362                            !mei_cl_is_connected(cl),
1363                            mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1364         mutex_lock(&dev->device_lock);
1365
1366         if (cl->notify_en != request && !cl->status)
1367                 cl->status = -EFAULT;
1368
1369         rets = cl->status;
1370
1371 out:
1372         cl_dbg(dev, cl, "rpm: autosuspend\n");
1373         pm_runtime_mark_last_busy(dev->dev);
1374         pm_runtime_put_autosuspend(dev->dev);
1375
1376         mei_io_cb_free(cb);
1377         return rets;
1378 }
1379
1380 /**
1381  * mei_cl_notify - raise notification
1382  *
1383  * @cl: host client
1384  *
1385  * Locking: called under "dev->device_lock" lock
1386  */
1387 void mei_cl_notify(struct mei_cl *cl)
1388 {
1389         struct mei_device *dev;
1390
1391         if (!cl || !cl->dev)
1392                 return;
1393
1394         dev = cl->dev;
1395
1396         if (!cl->notify_en)
1397                 return;
1398
1399         cl_dbg(dev, cl, "notify event");
1400         cl->notify_ev = true;
1401         if (!mei_cl_bus_notify_event(cl))
1402                 wake_up_interruptible(&cl->ev_wait);
1403
1404         if (cl->ev_async)
1405                 kill_fasync(&cl->ev_async, SIGIO, POLL_PRI);
1406
1407 }
1408
1409 /**
1410  * mei_cl_notify_get - get or wait for notification event
1411  *
1412  * @cl: host client
1413  * @block: this request is blocking
1414  * @notify_ev: true if notification event was received
1415  *
1416  * Locking: called under "dev->device_lock" lock
1417  *
1418  * Return: 0 on such and error otherwise.
1419  */
1420 int mei_cl_notify_get(struct mei_cl *cl, bool block, bool *notify_ev)
1421 {
1422         struct mei_device *dev;
1423         int rets;
1424
1425         *notify_ev = false;
1426
1427         if (WARN_ON(!cl || !cl->dev))
1428                 return -ENODEV;
1429
1430         dev = cl->dev;
1431
1432         if (!dev->hbm_f_ev_supported) {
1433                 cl_dbg(dev, cl, "notifications not supported\n");
1434                 return -EOPNOTSUPP;
1435         }
1436
1437         if (!mei_cl_is_connected(cl))
1438                 return -ENODEV;
1439
1440         if (cl->notify_ev)
1441                 goto out;
1442
1443         if (!block)
1444                 return -EAGAIN;
1445
1446         mutex_unlock(&dev->device_lock);
1447         rets = wait_event_interruptible(cl->ev_wait, cl->notify_ev);
1448         mutex_lock(&dev->device_lock);
1449
1450         if (rets < 0)
1451                 return rets;
1452
1453 out:
1454         *notify_ev = cl->notify_ev;
1455         cl->notify_ev = false;
1456         return 0;
1457 }
1458
1459 /**
1460  * mei_cl_read_start - the start read client message function.
1461  *
1462  * @cl: host client
1463  * @length: number of bytes to read
1464  * @fp: pointer to file structure
1465  *
1466  * Return: 0 on success, <0 on failure.
1467  */
1468 int mei_cl_read_start(struct mei_cl *cl, size_t length, const struct file *fp)
1469 {
1470         struct mei_device *dev;
1471         struct mei_cl_cb *cb;
1472         int rets;
1473
1474         if (WARN_ON(!cl || !cl->dev))
1475                 return -ENODEV;
1476
1477         dev = cl->dev;
1478
1479         if (!mei_cl_is_connected(cl))
1480                 return -ENODEV;
1481
1482         if (!mei_me_cl_is_active(cl->me_cl)) {
1483                 cl_err(dev, cl, "no such me client\n");
1484                 return  -ENOTTY;
1485         }
1486
1487         if (mei_cl_is_fixed_address(cl))
1488                 return 0;
1489
1490         /* HW currently supports only one pending read */
1491         if (cl->rx_flow_ctrl_creds)
1492                 return -EBUSY;
1493
1494         cb = mei_cl_enqueue_ctrl_wr_cb(cl, length, MEI_FOP_READ, fp);
1495         if (!cb)
1496                 return -ENOMEM;
1497
1498         rets = pm_runtime_get(dev->dev);
1499         if (rets < 0 && rets != -EINPROGRESS) {
1500                 pm_runtime_put_noidle(dev->dev);
1501                 cl_err(dev, cl, "rpm: get failed %d\n", rets);
1502                 goto nortpm;
1503         }
1504
1505         rets = 0;
1506         if (mei_hbuf_acquire(dev)) {
1507                 rets = mei_hbm_cl_flow_control_req(dev, cl);
1508                 if (rets < 0)
1509                         goto out;
1510
1511                 list_move_tail(&cb->list, &cl->rd_pending);
1512         }
1513         cl->rx_flow_ctrl_creds++;
1514
1515 out:
1516         cl_dbg(dev, cl, "rpm: autosuspend\n");
1517         pm_runtime_mark_last_busy(dev->dev);
1518         pm_runtime_put_autosuspend(dev->dev);
1519 nortpm:
1520         if (rets)
1521                 mei_io_cb_free(cb);
1522
1523         return rets;
1524 }
1525
1526 /**
1527  * mei_msg_hdr_init - initialize mei message header
1528  *
1529  * @mei_hdr: mei message header
1530  * @cb: message callback structure
1531  */
1532 static void mei_msg_hdr_init(struct mei_msg_hdr *mei_hdr, struct mei_cl_cb *cb)
1533 {
1534         mei_hdr->host_addr = mei_cl_host_addr(cb->cl);
1535         mei_hdr->me_addr = mei_cl_me_id(cb->cl);
1536         mei_hdr->length = 0;
1537         mei_hdr->reserved = 0;
1538         mei_hdr->msg_complete = 0;
1539         mei_hdr->dma_ring = 0;
1540         mei_hdr->internal = cb->internal;
1541 }
1542
1543 /**
1544  * mei_cl_irq_write - write a message to device
1545  *      from the interrupt thread context
1546  *
1547  * @cl: client
1548  * @cb: callback block.
1549  * @cmpl_list: complete list.
1550  *
1551  * Return: 0, OK; otherwise error.
1552  */
1553 int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
1554                      struct list_head *cmpl_list)
1555 {
1556         struct mei_device *dev;
1557         struct mei_msg_data *buf;
1558         struct mei_msg_hdr mei_hdr;
1559         size_t hdr_len = sizeof(mei_hdr);
1560         size_t len;
1561         size_t hbuf_len, dr_len;
1562         int hbuf_slots;
1563         u32 dr_slots;
1564         u32 dma_len;
1565         int rets;
1566         bool first_chunk;
1567         const void *data;
1568
1569         if (WARN_ON(!cl || !cl->dev))
1570                 return -ENODEV;
1571
1572         dev = cl->dev;
1573
1574         buf = &cb->buf;
1575
1576         first_chunk = cb->buf_idx == 0;
1577
1578         rets = first_chunk ? mei_cl_tx_flow_ctrl_creds(cl) : 1;
1579         if (rets < 0)
1580                 goto err;
1581
1582         if (rets == 0) {
1583                 cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1584                 return 0;
1585         }
1586
1587         len = buf->size - cb->buf_idx;
1588         data = buf->data + cb->buf_idx;
1589         hbuf_slots = mei_hbuf_empty_slots(dev);
1590         if (hbuf_slots < 0) {
1591                 rets = -EOVERFLOW;
1592                 goto err;
1593         }
1594
1595         hbuf_len = mei_slots2data(hbuf_slots);
1596         dr_slots = mei_dma_ring_empty_slots(dev);
1597         dr_len = mei_slots2data(dr_slots);
1598
1599         mei_msg_hdr_init(&mei_hdr, cb);
1600
1601         /**
1602          * Split the message only if we can write the whole host buffer
1603          * otherwise wait for next time the host buffer is empty.
1604          */
1605         if (len + hdr_len <= hbuf_len) {
1606                 mei_hdr.length = len;
1607                 mei_hdr.msg_complete = 1;
1608         } else if (dr_slots && hbuf_len >= hdr_len + sizeof(dma_len)) {
1609                 mei_hdr.dma_ring = 1;
1610                 if (len > dr_len)
1611                         len = dr_len;
1612                 else
1613                         mei_hdr.msg_complete = 1;
1614
1615                 mei_hdr.length = sizeof(dma_len);
1616                 dma_len = len;
1617                 data = &dma_len;
1618         } else if ((u32)hbuf_slots == mei_hbuf_depth(dev)) {
1619                 len = hbuf_len - hdr_len;
1620                 mei_hdr.length = len;
1621         } else {
1622                 return 0;
1623         }
1624
1625         if (mei_hdr.dma_ring)
1626                 mei_dma_ring_write(dev, buf->data + cb->buf_idx, len);
1627
1628         rets = mei_write_message(dev, &mei_hdr, hdr_len, data, mei_hdr.length);
1629         if (rets)
1630                 goto err;
1631
1632         cl->status = 0;
1633         cl->writing_state = MEI_WRITING;
1634         cb->buf_idx += len;
1635
1636         if (first_chunk) {
1637                 if (mei_cl_tx_flow_ctrl_creds_reduce(cl)) {
1638                         rets = -EIO;
1639                         goto err;
1640                 }
1641         }
1642
1643         if (mei_hdr.msg_complete)
1644                 list_move_tail(&cb->list, &dev->write_waiting_list);
1645
1646         return 0;
1647
1648 err:
1649         cl->status = rets;
1650         list_move_tail(&cb->list, cmpl_list);
1651         return rets;
1652 }
1653
1654 /**
1655  * mei_cl_write - submit a write cb to mei device
1656  *      assumes device_lock is locked
1657  *
1658  * @cl: host client
1659  * @cb: write callback with filled data
1660  *
1661  * Return: number of bytes sent on success, <0 on failure.
1662  */
1663 ssize_t mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb)
1664 {
1665         struct mei_device *dev;
1666         struct mei_msg_data *buf;
1667         struct mei_msg_hdr mei_hdr;
1668         size_t hdr_len = sizeof(mei_hdr);
1669         size_t len, hbuf_len, dr_len;
1670         int hbuf_slots;
1671         u32 dr_slots;
1672         u32 dma_len;
1673         ssize_t rets;
1674         bool blocking;
1675         const void *data;
1676
1677         if (WARN_ON(!cl || !cl->dev))
1678                 return -ENODEV;
1679
1680         if (WARN_ON(!cb))
1681                 return -EINVAL;
1682
1683         dev = cl->dev;
1684
1685         buf = &cb->buf;
1686         len = buf->size;
1687
1688         cl_dbg(dev, cl, "len=%zd\n", len);
1689
1690         blocking = cb->blocking;
1691         data = buf->data;
1692
1693         rets = pm_runtime_get(dev->dev);
1694         if (rets < 0 && rets != -EINPROGRESS) {
1695                 pm_runtime_put_noidle(dev->dev);
1696                 cl_err(dev, cl, "rpm: get failed %zd\n", rets);
1697                 goto free;
1698         }
1699
1700         cb->buf_idx = 0;
1701         cl->writing_state = MEI_IDLE;
1702
1703
1704         rets = mei_cl_tx_flow_ctrl_creds(cl);
1705         if (rets < 0)
1706                 goto err;
1707
1708         mei_msg_hdr_init(&mei_hdr, cb);
1709
1710         if (rets == 0) {
1711                 cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1712                 rets = len;
1713                 goto out;
1714         }
1715
1716         if (!mei_hbuf_acquire(dev)) {
1717                 cl_dbg(dev, cl, "Cannot acquire the host buffer: not sending.\n");
1718                 rets = len;
1719                 goto out;
1720         }
1721
1722         hbuf_slots = mei_hbuf_empty_slots(dev);
1723         if (hbuf_slots < 0) {
1724                 rets = -EOVERFLOW;
1725                 goto out;
1726         }
1727
1728         hbuf_len = mei_slots2data(hbuf_slots);
1729         dr_slots = mei_dma_ring_empty_slots(dev);
1730         dr_len =  mei_slots2data(dr_slots);
1731
1732         if (len + hdr_len <= hbuf_len) {
1733                 mei_hdr.length = len;
1734                 mei_hdr.msg_complete = 1;
1735         } else if (dr_slots && hbuf_len >= hdr_len + sizeof(dma_len)) {
1736                 mei_hdr.dma_ring = 1;
1737                 if (len > dr_len)
1738                         len = dr_len;
1739                 else
1740                         mei_hdr.msg_complete = 1;
1741
1742                 mei_hdr.length = sizeof(dma_len);
1743                 dma_len = len;
1744                 data = &dma_len;
1745         } else {
1746                 len = hbuf_len - hdr_len;
1747                 mei_hdr.length = len;
1748         }
1749
1750         if (mei_hdr.dma_ring)
1751                 mei_dma_ring_write(dev, buf->data, len);
1752
1753         rets = mei_write_message(dev, &mei_hdr, hdr_len,
1754                                  data, mei_hdr.length);
1755         if (rets)
1756                 goto err;
1757
1758         rets = mei_cl_tx_flow_ctrl_creds_reduce(cl);
1759         if (rets)
1760                 goto err;
1761
1762         cl->writing_state = MEI_WRITING;
1763         cb->buf_idx = len;
1764         /* restore return value */
1765         len = buf->size;
1766
1767 out:
1768         if (mei_hdr.msg_complete)
1769                 mei_tx_cb_enqueue(cb, &dev->write_waiting_list);
1770         else
1771                 mei_tx_cb_enqueue(cb, &dev->write_list);
1772
1773         cb = NULL;
1774         if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
1775
1776                 mutex_unlock(&dev->device_lock);
1777                 rets = wait_event_interruptible(cl->tx_wait,
1778                                 cl->writing_state == MEI_WRITE_COMPLETE ||
1779                                 (!mei_cl_is_connected(cl)));
1780                 mutex_lock(&dev->device_lock);
1781                 /* wait_event_interruptible returns -ERESTARTSYS */
1782                 if (rets) {
1783                         if (signal_pending(current))
1784                                 rets = -EINTR;
1785                         goto err;
1786                 }
1787                 if (cl->writing_state != MEI_WRITE_COMPLETE) {
1788                         rets = -EFAULT;
1789                         goto err;
1790                 }
1791         }
1792
1793         rets = len;
1794 err:
1795         cl_dbg(dev, cl, "rpm: autosuspend\n");
1796         pm_runtime_mark_last_busy(dev->dev);
1797         pm_runtime_put_autosuspend(dev->dev);
1798 free:
1799         mei_io_cb_free(cb);
1800
1801         return rets;
1802 }
1803
1804
1805 /**
1806  * mei_cl_complete - processes completed operation for a client
1807  *
1808  * @cl: private data of the file object.
1809  * @cb: callback block.
1810  */
1811 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
1812 {
1813         struct mei_device *dev = cl->dev;
1814
1815         switch (cb->fop_type) {
1816         case MEI_FOP_WRITE:
1817                 mei_tx_cb_dequeue(cb);
1818                 cl->writing_state = MEI_WRITE_COMPLETE;
1819                 if (waitqueue_active(&cl->tx_wait)) {
1820                         wake_up_interruptible(&cl->tx_wait);
1821                 } else {
1822                         pm_runtime_mark_last_busy(dev->dev);
1823                         pm_request_autosuspend(dev->dev);
1824                 }
1825                 break;
1826
1827         case MEI_FOP_READ:
1828                 list_add_tail(&cb->list, &cl->rd_completed);
1829                 if (!mei_cl_is_fixed_address(cl) &&
1830                     !WARN_ON(!cl->rx_flow_ctrl_creds))
1831                         cl->rx_flow_ctrl_creds--;
1832                 if (!mei_cl_bus_rx_event(cl))
1833                         wake_up_interruptible(&cl->rx_wait);
1834                 break;
1835
1836         case MEI_FOP_CONNECT:
1837         case MEI_FOP_DISCONNECT:
1838         case MEI_FOP_NOTIFY_STOP:
1839         case MEI_FOP_NOTIFY_START:
1840                 if (waitqueue_active(&cl->wait))
1841                         wake_up(&cl->wait);
1842
1843                 break;
1844         case MEI_FOP_DISCONNECT_RSP:
1845                 mei_io_cb_free(cb);
1846                 mei_cl_set_disconnected(cl);
1847                 break;
1848         default:
1849                 BUG_ON(0);
1850         }
1851 }
1852
1853
1854 /**
1855  * mei_cl_all_disconnect - disconnect forcefully all connected clients
1856  *
1857  * @dev: mei device
1858  */
1859 void mei_cl_all_disconnect(struct mei_device *dev)
1860 {
1861         struct mei_cl *cl;
1862
1863         list_for_each_entry(cl, &dev->file_list, link)
1864                 mei_cl_set_disconnected(cl);
1865 }