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_cl_cmp_id - tells if the clients are the same
 322  *
 323  * @cl1: host client 1
 324  * @cl2: host client 2
 325  *
 326  * Return: true  - if the clients has same host and me ids
 327  *         false - otherwise
 328  */
 329 static inline bool mei_cl_cmp_id(const struct mei_cl *cl1,
 330                                 const struct mei_cl *cl2)
 331 {
 332         return cl1 && cl2 &&
 333                 (cl1->host_client_id == cl2->host_client_id) &&
 334                 (mei_cl_me_id(cl1) == mei_cl_me_id(cl2));
 335 }
 336
 337 /**
 338  * mei_io_cb_free - free mei_cb_private related memory
 339  *
 340  * @cb: mei callback struct
 341  */
 342 void mei_io_cb_free(struct mei_cl_cb *cb)
 343 {
 344         if (cb == NULL)
 345                 return;
 346
 347         list_del(&cb->list);
 348         kfree(cb->buf.data);
 349         kfree(cb);
 350 }
 351
 352 /**
 353  * mei_io_cb_init - allocate and initialize io callback
 354  *
 355  * @cl: mei client
 356  * @type: operation type
 357  * @fp: pointer to file structure
 358  *
 359  * Return: mei_cl_cb pointer or NULL;
 360  */
 361 static struct mei_cl_cb *mei_io_cb_init(struct mei_cl *cl,
 362                                         enum mei_cb_file_ops type,
 363                                         const struct file *fp)
 364 {
 365         struct mei_cl_cb *cb;
 366
 367         cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
 368         if (!cb)
 369                 return NULL;
 370
 371         INIT_LIST_HEAD(&cb->list);
 372         cb->fp = fp;
 373         cb->cl = cl;
 374         cb->buf_idx = 0;
 375         cb->fop_type = type;
 376         return cb;
 377 }
 378
 379 /**
 380  * __mei_io_list_flush_cl - removes and frees cbs belonging to cl.
 381  *
 382  * @head:  an instance of our list structure
 383  * @cl:    host client, can be NULL for flushing the whole list
 384  * @free:  whether to free the cbs
 385  */
 386 static void __mei_io_list_flush_cl(struct list_head *head,
 387                                    const struct mei_cl *cl, bool free)
 388 {
 389         struct mei_cl_cb *cb, *next;
 390
 391         /* enable removing everything if no cl is specified */
 392         list_for_each_entry_safe(cb, next, head, list) {
 393                 if (!cl || mei_cl_cmp_id(cl, cb->cl)) {
 394                         list_del_init(&cb->list);
 395                         if (free)
 396                                 mei_io_cb_free(cb);
 397                 }
 398         }
 399 }
 400
 401 /**
 402  * mei_io_list_flush_cl - removes list entry belonging to cl.
 403  *
 404  * @head: An instance of our list structure
 405  * @cl: host client
 406  */
 407 static inline void mei_io_list_flush_cl(struct list_head *head,
 408                                         const struct mei_cl *cl)
 409 {
 410         __mei_io_list_flush_cl(head, cl, false);
 411 }
 412
 413 /**
 414  * mei_io_list_free_cl - removes cb belonging to cl and free them
 415  *
 416  * @head: An instance of our list structure
 417  * @cl: host client
 418  */
 419 static inline void mei_io_list_free_cl(struct list_head *head,
 420                                        const struct mei_cl *cl)
 421 {
 422         __mei_io_list_flush_cl(head, cl, true);
 423 }
 424
 425 /**
 426  * mei_io_list_free_fp - free cb from a list that matches file pointer
 427  *
 428  * @head: io list
 429  * @fp: file pointer (matching cb file object), may be NULL
 430  */
 431 static void mei_io_list_free_fp(struct list_head *head, const struct file *fp)
 432 {
 433         struct mei_cl_cb *cb, *next;
 434
 435         list_for_each_entry_safe(cb, next, head, list)
 436                 if (!fp || fp == cb->fp)
 437                         mei_io_cb_free(cb);
 438 }
 439
 440 /**
 441  * mei_cl_alloc_cb - a convenient wrapper for allocating read cb
 442  *
 443  * @cl: host client
 444  * @length: size of the buffer
 445  * @fop_type: operation type
 446  * @fp: associated file pointer (might be NULL)
 447  *
 448  * Return: cb on success and NULL on failure
 449  */
 450 struct mei_cl_cb *mei_cl_alloc_cb(struct mei_cl *cl, size_t length,
 451                                   enum mei_cb_file_ops fop_type,
 452                                   const struct file *fp)
 453 {
 454         struct mei_cl_cb *cb;
 455
 456         cb = mei_io_cb_init(cl, fop_type, fp);
 457         if (!cb)
 458                 return NULL;
 459
 460         if (length == 0)
 461                 return cb;
 462
 463         cb->buf.data = kmalloc(length, GFP_KERNEL);
 464         if (!cb->buf.data) {
 465                 mei_io_cb_free(cb);
 466                 return NULL;
 467         }
 468         cb->buf.size = length;
 469
 470         return cb;
 471 }
 472
 473 /**
 474  * mei_cl_enqueue_ctrl_wr_cb - a convenient wrapper for allocating
 475  *     and enqueuing of the control commands cb
 476  *
 477  * @cl: host client
 478  * @length: size of the buffer
 479  * @fop_type: operation type
 480  * @fp: associated file pointer (might be NULL)
 481  *
 482  * Return: cb on success and NULL on failure
 483  * Locking: called under "dev->device_lock" lock
 484  */
 485 struct mei_cl_cb *mei_cl_enqueue_ctrl_wr_cb(struct mei_cl *cl, size_t length,
 486                                             enum mei_cb_file_ops fop_type,
 487                                             const struct file *fp)
 488 {
 489         struct mei_cl_cb *cb;
 490
 491         /* for RX always allocate at least client's mtu */
 492         if (length)
 493                 length = max_t(size_t, length, mei_cl_mtu(cl));
 494
 495         cb = mei_cl_alloc_cb(cl, length, fop_type, fp);
 496         if (!cb)
 497                 return NULL;
 498
 499         list_add_tail(&cb->list, &cl->dev->ctrl_wr_list);
 500         return cb;
 501 }
 502
 503 /**
 504  * mei_cl_read_cb - find this cl's callback in the read list
 505  *     for a specific file
 506  *
 507  * @cl: host client
 508  * @fp: file pointer (matching cb file object), may be NULL
 509  *
 510  * Return: cb on success, NULL if cb is not found
 511  */
 512 struct mei_cl_cb *mei_cl_read_cb(const struct mei_cl *cl, const struct file *fp)
 513 {
 514         struct mei_cl_cb *cb;
 515
 516         list_for_each_entry(cb, &cl->rd_completed, list)
 517                 if (!fp || fp == cb->fp)
 518                         return cb;
 519
 520         return NULL;
 521 }
 522
 523 /**
 524  * mei_cl_flush_queues - flushes queue lists belonging to cl.
 525  *
 526  * @cl: host client
 527  * @fp: file pointer (matching cb file object), may be NULL
 528  *
 529  * Return: 0 on success, -EINVAL if cl or cl->dev is NULL.
 530  */
 531 int mei_cl_flush_queues(struct mei_cl *cl, const struct file *fp)
 532 {
 533         struct mei_device *dev;
 534
 535         if (WARN_ON(!cl || !cl->dev))
 536                 return -EINVAL;
 537
 538         dev = cl->dev;
 539
 540         cl_dbg(dev, cl, "remove list entry belonging to cl\n");
 541         mei_io_list_free_cl(&cl->dev->write_list, cl);
 542         mei_io_list_free_cl(&cl->dev->write_waiting_list, cl);
 543         mei_io_list_flush_cl(&cl->dev->ctrl_wr_list, cl);
 544         mei_io_list_flush_cl(&cl->dev->ctrl_rd_list, cl);
 545         mei_io_list_free_fp(&cl->rd_pending, fp);
 546         mei_io_list_free_fp(&cl->rd_completed, fp);
 547
 548         return 0;
 549 }
 550
 551 /**
 552  * mei_cl_init - initializes cl.
 553  *
 554  * @cl: host client to be initialized
 555  * @dev: mei device
 556  */
 557 static void mei_cl_init(struct mei_cl *cl, struct mei_device *dev)
 558 {
 559         memset(cl, 0, sizeof(struct mei_cl));
 560         init_waitqueue_head(&cl->wait);
 561         init_waitqueue_head(&cl->rx_wait);
 562         init_waitqueue_head(&cl->tx_wait);
 563         init_waitqueue_head(&cl->ev_wait);
 564         INIT_LIST_HEAD(&cl->rd_completed);
 565         INIT_LIST_HEAD(&cl->rd_pending);
 566         INIT_LIST_HEAD(&cl->link);
 567         cl->writing_state = MEI_IDLE;
 568         cl->state = MEI_FILE_UNINITIALIZED;
 569         cl->dev = dev;
 570 }
 571
 572 /**
 573  * mei_cl_allocate - allocates cl  structure and sets it up.
 574  *
 575  * @dev: mei device
 576  * Return:  The allocated file or NULL on failure
 577  */
 578 struct mei_cl *mei_cl_allocate(struct mei_device *dev)
 579 {
 580         struct mei_cl *cl;
 581
 582         cl = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
 583         if (!cl)
 584                 return NULL;
 585
 586         mei_cl_init(cl, dev);
 587
 588         return cl;
 589 }
 590
 591 /**
 592  * mei_cl_link - allocate host id in the host map
 593  *
 594  * @cl: host client
 595  *
 596  * Return: 0 on success
 597  *      -EINVAL on incorrect values
 598  *      -EMFILE if open count exceeded.
 599  */
 600 int mei_cl_link(struct mei_cl *cl)
 601 {
 602         struct mei_device *dev;
 603         int id;
 604
 605         if (WARN_ON(!cl || !cl->dev))
 606                 return -EINVAL;
 607
 608         dev = cl->dev;
 609
 610         id = find_first_zero_bit(dev->host_clients_map, MEI_CLIENTS_MAX);
 611         if (id >= MEI_CLIENTS_MAX) {
 612                 dev_err(dev->dev, "id exceeded %d", MEI_CLIENTS_MAX);
 613                 return -EMFILE;
 614         }
 615
 616         if (dev->open_handle_count >= MEI_MAX_OPEN_HANDLE_COUNT) {
 617                 dev_err(dev->dev, "open_handle_count exceeded %d",
 618                         MEI_MAX_OPEN_HANDLE_COUNT);
 619                 return -EMFILE;
 620         }
 621
 622         dev->open_handle_count++;
 623
 624         cl->host_client_id = id;
 625         list_add_tail(&cl->link, &dev->file_list);
 626
 627         set_bit(id, dev->host_clients_map);
 628
 629         cl->state = MEI_FILE_INITIALIZING;
 630
 631         cl_dbg(dev, cl, "link cl\n");
 632         return 0;
 633 }
 634
 635 /**
 636  * mei_cl_unlink - remove host client from the list
 637  *
 638  * @cl: host client
 639  *
 640  * Return: always 0
 641  */
 642 int mei_cl_unlink(struct mei_cl *cl)
 643 {
 644         struct mei_device *dev;
 645
 646         /* don't shout on error exit path */
 647         if (!cl)
 648                 return 0;
 649
 650         if (WARN_ON(!cl->dev))
 651                 return 0;
 652
 653         dev = cl->dev;
 654
 655         cl_dbg(dev, cl, "unlink client");
 656
 657         if (dev->open_handle_count > 0)
 658                 dev->open_handle_count--;
 659
 660         /* never clear the 0 bit */
 661         if (cl->host_client_id)
 662                 clear_bit(cl->host_client_id, dev->host_clients_map);
 663
 664         list_del_init(&cl->link);
 665
 666         cl->state = MEI_FILE_UNINITIALIZED;
 667         cl->writing_state = MEI_IDLE;
 668
 669         WARN_ON(!list_empty(&cl->rd_completed) ||
 670                 !list_empty(&cl->rd_pending) ||
 671                 !list_empty(&cl->link));
 672
 673         return 0;
 674 }
 675
 676 void mei_host_client_init(struct mei_device *dev)
 677 {
 678         dev->dev_state = MEI_DEV_ENABLED;
 679         dev->reset_count = 0;
 680
 681         schedule_work(&dev->bus_rescan_work);
 682
 683         pm_runtime_mark_last_busy(dev->dev);
 684         dev_dbg(dev->dev, "rpm: autosuspend\n");
 685         pm_request_autosuspend(dev->dev);
 686 }
 687
 688 /**
 689  * mei_hbuf_acquire - try to acquire host buffer
 690  *
 691  * @dev: the device structure
 692  * Return: true if host buffer was acquired
 693  */
 694 bool mei_hbuf_acquire(struct mei_device *dev)
 695 {
 696         if (mei_pg_state(dev) == MEI_PG_ON ||
 697             mei_pg_in_transition(dev)) {
 698                 dev_dbg(dev->dev, "device is in pg\n");
 699                 return false;
 700         }
 701
 702         if (!dev->hbuf_is_ready) {
 703                 dev_dbg(dev->dev, "hbuf is not ready\n");
 704                 return false;
 705         }
 706
 707         dev->hbuf_is_ready = false;
 708
 709         return true;
 710 }
 711
 712 /**
 713  * mei_cl_wake_all - wake up readers, writers and event waiters so
 714  *                 they can be interrupted
 715  *
 716  * @cl: host client
 717  */
 718 static void mei_cl_wake_all(struct mei_cl *cl)
 719 {
 720         struct mei_device *dev = cl->dev;
 721
 722         /* synchronized under device mutex */
 723         if (waitqueue_active(&cl->rx_wait)) {
 724                 cl_dbg(dev, cl, "Waking up reading client!\n");
 725                 wake_up_interruptible(&cl->rx_wait);
 726         }
 727         /* synchronized under device mutex */
 728         if (waitqueue_active(&cl->tx_wait)) {
 729                 cl_dbg(dev, cl, "Waking up writing client!\n");
 730                 wake_up_interruptible(&cl->tx_wait);
 731         }
 732         /* synchronized under device mutex */
 733         if (waitqueue_active(&cl->ev_wait)) {
 734                 cl_dbg(dev, cl, "Waking up waiting for event clients!\n");
 735                 wake_up_interruptible(&cl->ev_wait);
 736         }
 737         /* synchronized under device mutex */
 738         if (waitqueue_active(&cl->wait)) {
 739                 cl_dbg(dev, cl, "Waking up ctrl write clients!\n");
 740                 wake_up(&cl->wait);
 741         }
 742 }
 743
 744 /**
 745  * mei_cl_set_disconnected - set disconnected state and clear
 746  *   associated states and resources
 747  *
 748  * @cl: host client
 749  */
 750 static void mei_cl_set_disconnected(struct mei_cl *cl)
 751 {
 752         struct mei_device *dev = cl->dev;
 753
 754         if (cl->state == MEI_FILE_DISCONNECTED ||
 755             cl->state <= MEI_FILE_INITIALIZING)
 756                 return;
 757
 758         cl->state = MEI_FILE_DISCONNECTED;
 759         mei_io_list_free_cl(&dev->write_list, cl);
 760         mei_io_list_free_cl(&dev->write_waiting_list, cl);
 761         mei_io_list_flush_cl(&dev->ctrl_rd_list, cl);
 762         mei_io_list_flush_cl(&dev->ctrl_wr_list, cl);
 763         mei_cl_wake_all(cl);
 764         cl->rx_flow_ctrl_creds = 0;
 765         cl->tx_flow_ctrl_creds = 0;
 766         cl->timer_count = 0;
 767
 768         mei_cl_bus_module_put(cl);
 769
 770         if (!cl->me_cl)
 771                 return;
 772
 773         if (!WARN_ON(cl->me_cl->connect_count == 0))
 774                 cl->me_cl->connect_count--;
 775
 776         if (cl->me_cl->connect_count == 0)
 777                 cl->me_cl->tx_flow_ctrl_creds = 0;
 778
 779         mei_me_cl_put(cl->me_cl);
 780         cl->me_cl = NULL;
 781 }
 782
 783 static int mei_cl_set_connecting(struct mei_cl *cl, struct mei_me_client *me_cl)
 784 {
 785         if (!mei_me_cl_get(me_cl))
 786                 return -ENOENT;
 787
 788         /* only one connection is allowed for fixed address clients */
 789         if (me_cl->props.fixed_address) {
 790                 if (me_cl->connect_count) {
 791                         mei_me_cl_put(me_cl);
 792                         return -EBUSY;
 793                 }
 794         }
 795
 796         cl->me_cl = me_cl;
 797         cl->state = MEI_FILE_CONNECTING;
 798         cl->me_cl->connect_count++;
 799
 800         return 0;
 801 }
 802
 803 /*
 804  * mei_cl_send_disconnect - send disconnect request
 805  *
 806  * @cl: host client
 807  * @cb: callback block
 808  *
 809  * Return: 0, OK; otherwise, error.
 810  */
 811 static int mei_cl_send_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb)
 812 {
 813         struct mei_device *dev;
 814         int ret;
 815
 816         dev = cl->dev;
 817
 818         ret = mei_hbm_cl_disconnect_req(dev, cl);
 819         cl->status = ret;
 820         if (ret) {
 821                 cl->state = MEI_FILE_DISCONNECT_REPLY;
 822                 return ret;
 823         }
 824
 825         list_move_tail(&cb->list, &dev->ctrl_rd_list);
 826         cl->timer_count = MEI_CONNECT_TIMEOUT;
 827         mei_schedule_stall_timer(dev);
 828
 829         return 0;
 830 }
 831
 832 /**
 833  * mei_cl_irq_disconnect - processes close related operation from
 834  *      interrupt thread context - send disconnect request
 835  *
 836  * @cl: client
 837  * @cb: callback block.
 838  * @cmpl_list: complete list.
 839  *
 840  * Return: 0, OK; otherwise, error.
 841  */
 842 int mei_cl_irq_disconnect(struct mei_cl *cl, struct mei_cl_cb *cb,
 843                           struct list_head *cmpl_list)
 844 {
 845         struct mei_device *dev = cl->dev;
 846         u32 msg_slots;
 847         int slots;
 848         int ret;
 849
 850         msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
 851         slots = mei_hbuf_empty_slots(dev);
 852
 853         if (slots < msg_slots)
 854                 return -EMSGSIZE;
 855
 856         ret = mei_cl_send_disconnect(cl, cb);
 857         if (ret)
 858                 list_move_tail(&cb->list, cmpl_list);
 859
 860         return ret;
 861 }
 862
 863 /**
 864  * __mei_cl_disconnect - disconnect host client from the me one
 865  *     internal function runtime pm has to be already acquired
 866  *
 867  * @cl: host client
 868  *
 869  * Return: 0 on success, <0 on failure.
 870  */
 871 static int __mei_cl_disconnect(struct mei_cl *cl)
 872 {
 873         struct mei_device *dev;
 874         struct mei_cl_cb *cb;
 875         int rets;
 876
 877         dev = cl->dev;
 878
 879         cl->state = MEI_FILE_DISCONNECTING;
 880
 881         cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, MEI_FOP_DISCONNECT, NULL);
 882         if (!cb) {
 883                 rets = -ENOMEM;
 884                 goto out;
 885         }
 886
 887         if (mei_hbuf_acquire(dev)) {
 888                 rets = mei_cl_send_disconnect(cl, cb);
 889                 if (rets) {
 890                         cl_err(dev, cl, "failed to disconnect.\n");
 891                         goto out;
 892                 }
 893         }
 894
 895         mutex_unlock(&dev->device_lock);
 896         wait_event_timeout(cl->wait,
 897                            cl->state == MEI_FILE_DISCONNECT_REPLY ||
 898                            cl->state == MEI_FILE_DISCONNECTED,
 899                            mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 900         mutex_lock(&dev->device_lock);
 901
 902         rets = cl->status;
 903         if (cl->state != MEI_FILE_DISCONNECT_REPLY &&
 904             cl->state != MEI_FILE_DISCONNECTED) {
 905                 cl_dbg(dev, cl, "timeout on disconnect from FW client.\n");
 906                 rets = -ETIME;
 907         }
 908
 909 out:
 910         /* we disconnect also on error */
 911         mei_cl_set_disconnected(cl);
 912         if (!rets)
 913                 cl_dbg(dev, cl, "successfully disconnected from FW client.\n");
 914
 915         mei_io_cb_free(cb);
 916         return rets;
 917 }
 918
 919 /**
 920  * mei_cl_disconnect - disconnect host client from the me one
 921  *
 922  * @cl: host client
 923  *
 924  * Locking: called under "dev->device_lock" lock
 925  *
 926  * Return: 0 on success, <0 on failure.
 927  */
 928 int mei_cl_disconnect(struct mei_cl *cl)
 929 {
 930         struct mei_device *dev;
 931         int rets;
 932
 933         if (WARN_ON(!cl || !cl->dev))
 934                 return -ENODEV;
 935
 936         dev = cl->dev;
 937
 938         cl_dbg(dev, cl, "disconnecting");
 939
 940         if (!mei_cl_is_connected(cl))
 941                 return 0;
 942
 943         if (mei_cl_is_fixed_address(cl)) {
 944                 mei_cl_set_disconnected(cl);
 945                 return 0;
 946         }
 947
 948         if (dev->dev_state == MEI_DEV_POWER_DOWN) {
 949                 cl_dbg(dev, cl, "Device is powering down, don't bother with disconnection\n");
 950                 mei_cl_set_disconnected(cl);
 951                 return 0;
 952         }
 953
 954         rets = pm_runtime_get(dev->dev);
 955         if (rets < 0 && rets != -EINPROGRESS) {
 956                 pm_runtime_put_noidle(dev->dev);
 957                 cl_err(dev, cl, "rpm: get failed %d\n", rets);
 958                 return rets;
 959         }
 960
 961         rets = __mei_cl_disconnect(cl);
 962
 963         cl_dbg(dev, cl, "rpm: autosuspend\n");
 964         pm_runtime_mark_last_busy(dev->dev);
 965         pm_runtime_put_autosuspend(dev->dev);
 966
 967         return rets;
 968 }
 969
 970
 971 /**
 972  * mei_cl_is_other_connecting - checks if other
 973  *    client with the same me client id is connecting
 974  *
 975  * @cl: private data of the file object
 976  *
 977  * Return: true if other client is connected, false - otherwise.
 978  */
 979 static bool mei_cl_is_other_connecting(struct mei_cl *cl)
 980 {
 981         struct mei_device *dev;
 982         struct mei_cl_cb *cb;
 983
 984         dev = cl->dev;
 985
 986         list_for_each_entry(cb, &dev->ctrl_rd_list, list) {
 987                 if (cb->fop_type == MEI_FOP_CONNECT &&
 988                     mei_cl_me_id(cl) == mei_cl_me_id(cb->cl))
 989                         return true;
 990         }
 991
 992         return false;
 993 }
 994
 995 /**
 996  * mei_cl_send_connect - send connect request
 997  *
 998  * @cl: host client
 999  * @cb: callback block
1000  *
1001  * Return: 0, OK; otherwise, error.
1002  */
1003 static int mei_cl_send_connect(struct mei_cl *cl, struct mei_cl_cb *cb)
1004 {
1005         struct mei_device *dev;
1006         int ret;
1007
1008         dev = cl->dev;
1009
1010         ret = mei_hbm_cl_connect_req(dev, cl);
1011         cl->status = ret;
1012         if (ret) {
1013                 cl->state = MEI_FILE_DISCONNECT_REPLY;
1014                 return ret;
1015         }
1016
1017         list_move_tail(&cb->list, &dev->ctrl_rd_list);
1018         cl->timer_count = MEI_CONNECT_TIMEOUT;
1019         mei_schedule_stall_timer(dev);
1020         return 0;
1021 }
1022
1023 /**
1024  * mei_cl_irq_connect - send connect request in irq_thread context
1025  *
1026  * @cl: host client
1027  * @cb: callback block
1028  * @cmpl_list: complete list
1029  *
1030  * Return: 0, OK; otherwise, error.
1031  */
1032 int mei_cl_irq_connect(struct mei_cl *cl, struct mei_cl_cb *cb,
1033                        struct list_head *cmpl_list)
1034 {
1035         struct mei_device *dev = cl->dev;
1036         u32 msg_slots;
1037         int slots;
1038         int rets;
1039
1040         msg_slots = mei_data2slots(sizeof(struct hbm_client_connect_request));
1041         slots = mei_hbuf_empty_slots(dev);
1042
1043         if (mei_cl_is_other_connecting(cl))
1044                 return 0;
1045
1046         if (slots < msg_slots)
1047                 return -EMSGSIZE;
1048
1049         rets = mei_cl_send_connect(cl, cb);
1050         if (rets)
1051                 list_move_tail(&cb->list, cmpl_list);
1052
1053         return rets;
1054 }
1055
1056 /**
1057  * mei_cl_connect - connect host client to the me one
1058  *
1059  * @cl: host client
1060  * @me_cl: me client
1061  * @fp: pointer to file structure
1062  *
1063  * Locking: called under "dev->device_lock" lock
1064  *
1065  * Return: 0 on success, <0 on failure.
1066  */
1067 int mei_cl_connect(struct mei_cl *cl, struct mei_me_client *me_cl,
1068                    const struct file *fp)
1069 {
1070         struct mei_device *dev;
1071         struct mei_cl_cb *cb;
1072         int rets;
1073
1074         if (WARN_ON(!cl || !cl->dev || !me_cl))
1075                 return -ENODEV;
1076
1077         dev = cl->dev;
1078
1079         if (!mei_cl_bus_module_get(cl))
1080                 return -ENODEV;
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_data2slots(sizeof(struct hbm_client_connect_request));
1285         slots = mei_hbuf_empty_slots(dev);
1286
1287         if (slots < msg_slots)
1288                 return -EMSGSIZE;
1289
1290         request = mei_cl_notify_fop2req(cb->fop_type);
1291         ret = mei_hbm_cl_notify_req(dev, cl, request);
1292         if (ret) {
1293                 cl->status = ret;
1294                 list_move_tail(&cb->list, cmpl_list);
1295                 return ret;
1296         }
1297
1298         list_move_tail(&cb->list, &dev->ctrl_rd_list);
1299         return 0;
1300 }
1301
1302 /**
1303  * mei_cl_notify_request - send notification stop/start request
1304  *
1305  * @cl: host client
1306  * @fp: associate request with file
1307  * @request: 1 for start or 0 for stop
1308  *
1309  * Locking: called under "dev->device_lock" lock
1310  *
1311  * Return: 0 on such and error otherwise.
1312  */
1313 int mei_cl_notify_request(struct mei_cl *cl,
1314                           const struct file *fp, u8 request)
1315 {
1316         struct mei_device *dev;
1317         struct mei_cl_cb *cb;
1318         enum mei_cb_file_ops fop_type;
1319         int rets;
1320
1321         if (WARN_ON(!cl || !cl->dev))
1322                 return -ENODEV;
1323
1324         dev = cl->dev;
1325
1326         if (!dev->hbm_f_ev_supported) {
1327                 cl_dbg(dev, cl, "notifications not supported\n");
1328                 return -EOPNOTSUPP;
1329         }
1330
1331         if (!mei_cl_is_connected(cl))
1332                 return -ENODEV;
1333
1334         rets = pm_runtime_get(dev->dev);
1335         if (rets < 0 && rets != -EINPROGRESS) {
1336                 pm_runtime_put_noidle(dev->dev);
1337                 cl_err(dev, cl, "rpm: get failed %d\n", rets);
1338                 return rets;
1339         }
1340
1341         fop_type = mei_cl_notify_req2fop(request);
1342         cb = mei_cl_enqueue_ctrl_wr_cb(cl, 0, fop_type, fp);
1343         if (!cb) {
1344                 rets = -ENOMEM;
1345                 goto out;
1346         }
1347
1348         if (mei_hbuf_acquire(dev)) {
1349                 if (mei_hbm_cl_notify_req(dev, cl, request)) {
1350                         rets = -ENODEV;
1351                         goto out;
1352                 }
1353                 list_move_tail(&cb->list, &dev->ctrl_rd_list);
1354         }
1355
1356         mutex_unlock(&dev->device_lock);
1357         wait_event_timeout(cl->wait,
1358                            cl->notify_en == request || !mei_cl_is_connected(cl),
1359                            mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
1360         mutex_lock(&dev->device_lock);
1361
1362         if (cl->notify_en != request && !cl->status)
1363                 cl->status = -EFAULT;
1364
1365         rets = cl->status;
1366
1367 out:
1368         cl_dbg(dev, cl, "rpm: autosuspend\n");
1369         pm_runtime_mark_last_busy(dev->dev);
1370         pm_runtime_put_autosuspend(dev->dev);
1371
1372         mei_io_cb_free(cb);
1373         return rets;
1374 }
1375
1376 /**
1377  * mei_cl_notify - raise notification
1378  *
1379  * @cl: host client
1380  *
1381  * Locking: called under "dev->device_lock" lock
1382  */
1383 void mei_cl_notify(struct mei_cl *cl)
1384 {
1385         struct mei_device *dev;
1386
1387         if (!cl || !cl->dev)
1388                 return;
1389
1390         dev = cl->dev;
1391
1392         if (!cl->notify_en)
1393                 return;
1394
1395         cl_dbg(dev, cl, "notify event");
1396         cl->notify_ev = true;
1397         if (!mei_cl_bus_notify_event(cl))
1398                 wake_up_interruptible(&cl->ev_wait);
1399
1400         if (cl->ev_async)
1401                 kill_fasync(&cl->ev_async, SIGIO, POLL_PRI);
1402
1403 }
1404
1405 /**
1406  * mei_cl_notify_get - get or wait for notification event
1407  *
1408  * @cl: host client
1409  * @block: this request is blocking
1410  * @notify_ev: true if notification event was received
1411  *
1412  * Locking: called under "dev->device_lock" lock
1413  *
1414  * Return: 0 on such and error otherwise.
1415  */
1416 int mei_cl_notify_get(struct mei_cl *cl, bool block, bool *notify_ev)
1417 {
1418         struct mei_device *dev;
1419         int rets;
1420
1421         *notify_ev = false;
1422
1423         if (WARN_ON(!cl || !cl->dev))
1424                 return -ENODEV;
1425
1426         dev = cl->dev;
1427
1428         if (!dev->hbm_f_ev_supported) {
1429                 cl_dbg(dev, cl, "notifications not supported\n");
1430                 return -EOPNOTSUPP;
1431         }
1432
1433         if (!mei_cl_is_connected(cl))
1434                 return -ENODEV;
1435
1436         if (cl->notify_ev)
1437                 goto out;
1438
1439         if (!block)
1440                 return -EAGAIN;
1441
1442         mutex_unlock(&dev->device_lock);
1443         rets = wait_event_interruptible(cl->ev_wait, cl->notify_ev);
1444         mutex_lock(&dev->device_lock);
1445
1446         if (rets < 0)
1447                 return rets;
1448
1449 out:
1450         *notify_ev = cl->notify_ev;
1451         cl->notify_ev = false;
1452         return 0;
1453 }
1454
1455 /**
1456  * mei_cl_read_start - the start read client message function.
1457  *
1458  * @cl: host client
1459  * @length: number of bytes to read
1460  * @fp: pointer to file structure
1461  *
1462  * Return: 0 on success, <0 on failure.
1463  */
1464 int mei_cl_read_start(struct mei_cl *cl, size_t length, const struct file *fp)
1465 {
1466         struct mei_device *dev;
1467         struct mei_cl_cb *cb;
1468         int rets;
1469
1470         if (WARN_ON(!cl || !cl->dev))
1471                 return -ENODEV;
1472
1473         dev = cl->dev;
1474
1475         if (!mei_cl_is_connected(cl))
1476                 return -ENODEV;
1477
1478         if (!mei_me_cl_is_active(cl->me_cl)) {
1479                 cl_err(dev, cl, "no such me client\n");
1480                 return  -ENOTTY;
1481         }
1482
1483         if (mei_cl_is_fixed_address(cl))
1484                 return 0;
1485
1486         /* HW currently supports only one pending read */
1487         if (cl->rx_flow_ctrl_creds)
1488                 return -EBUSY;
1489
1490         cb = mei_cl_enqueue_ctrl_wr_cb(cl, length, MEI_FOP_READ, fp);
1491         if (!cb)
1492                 return -ENOMEM;
1493
1494         rets = pm_runtime_get(dev->dev);
1495         if (rets < 0 && rets != -EINPROGRESS) {
1496                 pm_runtime_put_noidle(dev->dev);
1497                 cl_err(dev, cl, "rpm: get failed %d\n", rets);
1498                 goto nortpm;
1499         }
1500
1501         rets = 0;
1502         if (mei_hbuf_acquire(dev)) {
1503                 rets = mei_hbm_cl_flow_control_req(dev, cl);
1504                 if (rets < 0)
1505                         goto out;
1506
1507                 list_move_tail(&cb->list, &cl->rd_pending);
1508         }
1509         cl->rx_flow_ctrl_creds++;
1510
1511 out:
1512         cl_dbg(dev, cl, "rpm: autosuspend\n");
1513         pm_runtime_mark_last_busy(dev->dev);
1514         pm_runtime_put_autosuspend(dev->dev);
1515 nortpm:
1516         if (rets)
1517                 mei_io_cb_free(cb);
1518
1519         return rets;
1520 }
1521
1522 /**
1523  * mei_cl_irq_write - write a message to device
1524  *      from the interrupt thread context
1525  *
1526  * @cl: client
1527  * @cb: callback block.
1528  * @cmpl_list: complete list.
1529  *
1530  * Return: 0, OK; otherwise error.
1531  */
1532 int mei_cl_irq_write(struct mei_cl *cl, struct mei_cl_cb *cb,
1533                      struct list_head *cmpl_list)
1534 {
1535         struct mei_device *dev;
1536         struct mei_msg_data *buf;
1537         struct mei_msg_hdr mei_hdr;
1538         size_t len;
1539         u32 msg_slots;
1540         int slots;
1541         int rets;
1542         bool first_chunk;
1543
1544         if (WARN_ON(!cl || !cl->dev))
1545                 return -ENODEV;
1546
1547         dev = cl->dev;
1548
1549         buf = &cb->buf;
1550
1551         first_chunk = cb->buf_idx == 0;
1552
1553         rets = first_chunk ? mei_cl_tx_flow_ctrl_creds(cl) : 1;
1554         if (rets < 0)
1555                 goto err;
1556
1557         if (rets == 0) {
1558                 cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1559                 return 0;
1560         }
1561
1562         slots = mei_hbuf_empty_slots(dev);
1563         len = buf->size - cb->buf_idx;
1564         msg_slots = mei_data2slots(len);
1565
1566         mei_hdr.host_addr = mei_cl_host_addr(cl);
1567         mei_hdr.me_addr = mei_cl_me_id(cl);
1568         mei_hdr.reserved = 0;
1569         mei_hdr.internal = cb->internal;
1570
1571         if (slots >= msg_slots) {
1572                 mei_hdr.length = len;
1573                 mei_hdr.msg_complete = 1;
1574         /* Split the message only if we can write the whole host buffer */
1575         } else if (slots == dev->hbuf_depth) {
1576                 msg_slots = slots;
1577                 len = (slots * sizeof(u32)) - sizeof(struct mei_msg_hdr);
1578                 mei_hdr.length = len;
1579                 mei_hdr.msg_complete = 0;
1580         } else {
1581                 /* wait for next time the host buffer is empty */
1582                 return 0;
1583         }
1584
1585         cl_dbg(dev, cl, "buf: size = %zu idx = %zu\n",
1586                         cb->buf.size, cb->buf_idx);
1587
1588         rets = mei_write_message(dev, &mei_hdr, buf->data + cb->buf_idx);
1589         if (rets)
1590                 goto err;
1591
1592         cl->status = 0;
1593         cl->writing_state = MEI_WRITING;
1594         cb->buf_idx += mei_hdr.length;
1595         cb->completed = mei_hdr.msg_complete == 1;
1596
1597         if (first_chunk) {
1598                 if (mei_cl_tx_flow_ctrl_creds_reduce(cl)) {
1599                         rets = -EIO;
1600                         goto err;
1601                 }
1602         }
1603
1604         if (mei_hdr.msg_complete)
1605                 list_move_tail(&cb->list, &dev->write_waiting_list);
1606
1607         return 0;
1608
1609 err:
1610         cl->status = rets;
1611         list_move_tail(&cb->list, cmpl_list);
1612         return rets;
1613 }
1614
1615 /**
1616  * mei_cl_write - submit a write cb to mei device
1617  *      assumes device_lock is locked
1618  *
1619  * @cl: host client
1620  * @cb: write callback with filled data
1621  *
1622  * Return: number of bytes sent on success, <0 on failure.
1623  */
1624 int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb)
1625 {
1626         struct mei_device *dev;
1627         struct mei_msg_data *buf;
1628         struct mei_msg_hdr mei_hdr;
1629         int size;
1630         int rets;
1631         bool blocking;
1632
1633         if (WARN_ON(!cl || !cl->dev))
1634                 return -ENODEV;
1635
1636         if (WARN_ON(!cb))
1637                 return -EINVAL;
1638
1639         dev = cl->dev;
1640
1641         buf = &cb->buf;
1642         size = buf->size;
1643         blocking = cb->blocking;
1644
1645         cl_dbg(dev, cl, "size=%d\n", size);
1646
1647         rets = pm_runtime_get(dev->dev);
1648         if (rets < 0 && rets != -EINPROGRESS) {
1649                 pm_runtime_put_noidle(dev->dev);
1650                 cl_err(dev, cl, "rpm: get failed %d\n", rets);
1651                 goto free;
1652         }
1653
1654         cb->buf_idx = 0;
1655         cl->writing_state = MEI_IDLE;
1656
1657         mei_hdr.host_addr = mei_cl_host_addr(cl);
1658         mei_hdr.me_addr = mei_cl_me_id(cl);
1659         mei_hdr.reserved = 0;
1660         mei_hdr.msg_complete = 0;
1661         mei_hdr.internal = cb->internal;
1662
1663         rets = mei_cl_tx_flow_ctrl_creds(cl);
1664         if (rets < 0)
1665                 goto err;
1666
1667         if (rets == 0) {
1668                 cl_dbg(dev, cl, "No flow control credentials: not sending.\n");
1669                 rets = size;
1670                 goto out;
1671         }
1672         if (!mei_hbuf_acquire(dev)) {
1673                 cl_dbg(dev, cl, "Cannot acquire the host buffer: not sending.\n");
1674                 rets = size;
1675                 goto out;
1676         }
1677
1678         /* Check for a maximum length */
1679         if (size > mei_hbuf_max_len(dev)) {
1680                 mei_hdr.length = mei_hbuf_max_len(dev);
1681                 mei_hdr.msg_complete = 0;
1682         } else {
1683                 mei_hdr.length = size;
1684                 mei_hdr.msg_complete = 1;
1685         }
1686
1687         rets = mei_write_message(dev, &mei_hdr, buf->data);
1688         if (rets)
1689                 goto err;
1690
1691         rets = mei_cl_tx_flow_ctrl_creds_reduce(cl);
1692         if (rets)
1693                 goto err;
1694
1695         cl->writing_state = MEI_WRITING;
1696         cb->buf_idx = mei_hdr.length;
1697         cb->completed = mei_hdr.msg_complete == 1;
1698
1699 out:
1700         if (mei_hdr.msg_complete)
1701                 list_add_tail(&cb->list, &dev->write_waiting_list);
1702         else
1703                 list_add_tail(&cb->list, &dev->write_list);
1704
1705         cb = NULL;
1706         if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
1707
1708                 mutex_unlock(&dev->device_lock);
1709                 rets = wait_event_interruptible(cl->tx_wait,
1710                                 cl->writing_state == MEI_WRITE_COMPLETE ||
1711                                 (!mei_cl_is_connected(cl)));
1712                 mutex_lock(&dev->device_lock);
1713                 /* wait_event_interruptible returns -ERESTARTSYS */
1714                 if (rets) {
1715                         if (signal_pending(current))
1716                                 rets = -EINTR;
1717                         goto err;
1718                 }
1719                 if (cl->writing_state != MEI_WRITE_COMPLETE) {
1720                         rets = -EFAULT;
1721                         goto err;
1722                 }
1723         }
1724
1725         rets = size;
1726 err:
1727         cl_dbg(dev, cl, "rpm: autosuspend\n");
1728         pm_runtime_mark_last_busy(dev->dev);
1729         pm_runtime_put_autosuspend(dev->dev);
1730 free:
1731         mei_io_cb_free(cb);
1732
1733         return rets;
1734 }
1735
1736
1737 /**
1738  * mei_cl_complete - processes completed operation for a client
1739  *
1740  * @cl: private data of the file object.
1741  * @cb: callback block.
1742  */
1743 void mei_cl_complete(struct mei_cl *cl, struct mei_cl_cb *cb)
1744 {
1745         struct mei_device *dev = cl->dev;
1746
1747         switch (cb->fop_type) {
1748         case MEI_FOP_WRITE:
1749                 mei_io_cb_free(cb);
1750                 cl->writing_state = MEI_WRITE_COMPLETE;
1751                 if (waitqueue_active(&cl->tx_wait)) {
1752                         wake_up_interruptible(&cl->tx_wait);
1753                 } else {
1754                         pm_runtime_mark_last_busy(dev->dev);
1755                         pm_request_autosuspend(dev->dev);
1756                 }
1757                 break;
1758
1759         case MEI_FOP_READ:
1760                 list_add_tail(&cb->list, &cl->rd_completed);
1761                 if (!mei_cl_is_fixed_address(cl) &&
1762                     !WARN_ON(!cl->rx_flow_ctrl_creds))
1763                         cl->rx_flow_ctrl_creds--;
1764                 if (!mei_cl_bus_rx_event(cl))
1765                         wake_up_interruptible(&cl->rx_wait);
1766                 break;
1767
1768         case MEI_FOP_CONNECT:
1769         case MEI_FOP_DISCONNECT:
1770         case MEI_FOP_NOTIFY_STOP:
1771         case MEI_FOP_NOTIFY_START:
1772                 if (waitqueue_active(&cl->wait))
1773                         wake_up(&cl->wait);
1774
1775                 break;
1776         case MEI_FOP_DISCONNECT_RSP:
1777                 mei_io_cb_free(cb);
1778                 mei_cl_set_disconnected(cl);
1779                 break;
1780         default:
1781                 BUG_ON(0);
1782         }
1783 }
1784
1785
1786 /**
1787  * mei_cl_all_disconnect - disconnect forcefully all connected clients
1788  *
1789  * @dev: mei device
1790  */
1791 void mei_cl_all_disconnect(struct mei_device *dev)
1792 {
1793         struct mei_cl *cl;
1794
1795         list_for_each_entry(cl, &dev->file_list, link)
1796                 mei_cl_set_disconnected(cl);
1797 }