drivers/misc/mei/client.c

   1 /*
   2  *
   3  * Intel Management Engine Interface (Intel MEI) Linux driver
   4  * Copyright (c) 2003-2012, Intel Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify it
   7  * under the terms and conditions of the GNU General Public License,
   8  * version 2, as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  13  * more details.
  14  *
  15  */
  16
  17 #include <linux/pci.h>
  18 #include <linux/sched.h>
  19 #include <linux/wait.h>
  20 #include <linux/delay.h>
  21
  22 #include <linux/mei.h>
  23
  24 #include "mei_dev.h"
  25 #include "hbm.h"
  26 #include "client.h"
  27
  28 /**
  29  * mei_me_cl_by_uuid - locate index of me client
  30  *
  31  * @dev: mei device
  32  * returns me client index or -ENOENT if not found
  33  */
  34 int mei_me_cl_by_uuid(const struct mei_device *dev, const uuid_le *uuid)
  35 {
  36         int i, res = -ENOENT;
  37
  38         for (i = 0; i < dev->me_clients_num; ++i)
  39                 if (uuid_le_cmp(*uuid,
  40                                 dev->me_clients[i].props.protocol_name) == 0) {
  41                         res = i;
  42                         break;
  43                 }
  44
  45         return res;
  46 }
  47
  48
  49 /**
  50  * mei_me_cl_by_id return index to me_clients for client_id
  51  *
  52  * @dev: the device structure
  53  * @client_id: me client id
  54  *
  55  * Locking: called under "dev->device_lock" lock
  56  *
  57  * returns index on success, -ENOENT on failure.
  58  */
  59
  60 int mei_me_cl_by_id(struct mei_device *dev, u8 client_id)
  61 {
  62         int i;
  63         for (i = 0; i < dev->me_clients_num; i++)
  64                 if (dev->me_clients[i].client_id == client_id)
  65                         break;
  66         if (WARN_ON(dev->me_clients[i].client_id != client_id))
  67                 return -ENOENT;
  68
  69         if (i == dev->me_clients_num)
  70                 return -ENOENT;
  71
  72         return i;
  73 }
  74
  75
  76 /**
  77  * mei_io_list_flush - removes list entry belonging to cl.
  78  *
  79  * @list:  An instance of our list structure
  80  * @cl: host client
  81  */
  82 void mei_io_list_flush(struct mei_cl_cb *list, struct mei_cl *cl)
  83 {
  84         struct mei_cl_cb *cb;
  85         struct mei_cl_cb *next;
  86
  87         list_for_each_entry_safe(cb, next, &list->list, list) {
  88                 if (cb->cl && mei_cl_cmp_id(cl, cb->cl))
  89                         list_del(&cb->list);
  90         }
  91 }
  92
  93 /**
  94  * mei_io_cb_free - free mei_cb_private related memory
  95  *
  96  * @cb: mei callback struct
  97  */
  98 void mei_io_cb_free(struct mei_cl_cb *cb)
  99 {
 100         if (cb == NULL)
 101                 return;
 102
 103         kfree(cb->request_buffer.data);
 104         kfree(cb->response_buffer.data);
 105         kfree(cb);
 106 }
 107
 108 /**
 109  * mei_io_cb_init - allocate and initialize io callback
 110  *
 111  * @cl - mei client
 112  * @fp: pointer to file structure
 113  *
 114  * returns mei_cl_cb pointer or NULL;
 115  */
 116 struct mei_cl_cb *mei_io_cb_init(struct mei_cl *cl, struct file *fp)
 117 {
 118         struct mei_cl_cb *cb;
 119
 120         cb = kzalloc(sizeof(struct mei_cl_cb), GFP_KERNEL);
 121         if (!cb)
 122                 return NULL;
 123
 124         mei_io_list_init(cb);
 125
 126         cb->file_object = fp;
 127         cb->cl = cl;
 128         cb->buf_idx = 0;
 129         return cb;
 130 }
 131
 132 /**
 133  * mei_io_cb_alloc_req_buf - allocate request buffer
 134  *
 135  * @cb: io callback structure
 136  * @length: size of the buffer
 137  *
 138  * returns 0 on success
 139  *         -EINVAL if cb is NULL
 140  *         -ENOMEM if allocation failed
 141  */
 142 int mei_io_cb_alloc_req_buf(struct mei_cl_cb *cb, size_t length)
 143 {
 144         if (!cb)
 145                 return -EINVAL;
 146
 147         if (length == 0)
 148                 return 0;
 149
 150         cb->request_buffer.data = kmalloc(length, GFP_KERNEL);
 151         if (!cb->request_buffer.data)
 152                 return -ENOMEM;
 153         cb->request_buffer.size = length;
 154         return 0;
 155 }
 156 /**
 157  * mei_io_cb_alloc_resp_buf - allocate respose buffer
 158  *
 159  * @cb: io callback structure
 160  * @length: size of the buffer
 161  *
 162  * returns 0 on success
 163  *         -EINVAL if cb is NULL
 164  *         -ENOMEM if allocation failed
 165  */
 166 int mei_io_cb_alloc_resp_buf(struct mei_cl_cb *cb, size_t length)
 167 {
 168         if (!cb)
 169                 return -EINVAL;
 170
 171         if (length == 0)
 172                 return 0;
 173
 174         cb->response_buffer.data = kmalloc(length, GFP_KERNEL);
 175         if (!cb->response_buffer.data)
 176                 return -ENOMEM;
 177         cb->response_buffer.size = length;
 178         return 0;
 179 }
 180
 181
 182
 183 /**
 184  * mei_cl_flush_queues - flushes queue lists belonging to cl.
 185  *
 186  * @cl: host client
 187  */
 188 int mei_cl_flush_queues(struct mei_cl *cl)
 189 {
 190         if (WARN_ON(!cl || !cl->dev))
 191                 return -EINVAL;
 192
 193         dev_dbg(&cl->dev->pdev->dev, "remove list entry belonging to cl\n");
 194         mei_io_list_flush(&cl->dev->read_list, cl);
 195         mei_io_list_flush(&cl->dev->write_list, cl);
 196         mei_io_list_flush(&cl->dev->write_waiting_list, cl);
 197         mei_io_list_flush(&cl->dev->ctrl_wr_list, cl);
 198         mei_io_list_flush(&cl->dev->ctrl_rd_list, cl);
 199         mei_io_list_flush(&cl->dev->amthif_cmd_list, cl);
 200         mei_io_list_flush(&cl->dev->amthif_rd_complete_list, cl);
 201         return 0;
 202 }
 203
 204
 205 /**
 206  * mei_cl_init - initializes intialize cl.
 207  *
 208  * @cl: host client to be initialized
 209  * @dev: mei device
 210  */
 211 void mei_cl_init(struct mei_cl *cl, struct mei_device *dev)
 212 {
 213         memset(cl, 0, sizeof(struct mei_cl));
 214         init_waitqueue_head(&cl->wait);
 215         init_waitqueue_head(&cl->rx_wait);
 216         init_waitqueue_head(&cl->tx_wait);
 217         INIT_LIST_HEAD(&cl->link);
 218         INIT_LIST_HEAD(&cl->device_link);
 219         cl->reading_state = MEI_IDLE;
 220         cl->writing_state = MEI_IDLE;
 221         cl->dev = dev;
 222 }
 223
 224 /**
 225  * mei_cl_allocate - allocates cl  structure and sets it up.
 226  *
 227  * @dev: mei device
 228  * returns  The allocated file or NULL on failure
 229  */
 230 struct mei_cl *mei_cl_allocate(struct mei_device *dev)
 231 {
 232         struct mei_cl *cl;
 233
 234         cl = kmalloc(sizeof(struct mei_cl), GFP_KERNEL);
 235         if (!cl)
 236                 return NULL;
 237
 238         mei_cl_init(cl, dev);
 239
 240         return cl;
 241 }
 242
 243 /**
 244  * mei_cl_find_read_cb - find this cl's callback in the read list
 245  *
 246  * @cl: host client
 247  *
 248  * returns cb on success, NULL on error
 249  */
 250 struct mei_cl_cb *mei_cl_find_read_cb(struct mei_cl *cl)
 251 {
 252         struct mei_device *dev = cl->dev;
 253         struct mei_cl_cb *cb = NULL;
 254         struct mei_cl_cb *next = NULL;
 255
 256         list_for_each_entry_safe(cb, next, &dev->read_list.list, list)
 257                 if (mei_cl_cmp_id(cl, cb->cl))
 258                         return cb;
 259         return NULL;
 260 }
 261
 262 /** mei_cl_link: allocte host id in the host map
 263  *
 264  * @cl - host client
 265  * @id - fixed host id or -1 for genereting one
 266  *
 267  * returns 0 on success
 268  *      -EINVAL on incorrect values
 269  *      -ENONET if client not found
 270  */
 271 int mei_cl_link(struct mei_cl *cl, int id)
 272 {
 273         struct mei_device *dev;
 274
 275         if (WARN_ON(!cl || !cl->dev))
 276                 return -EINVAL;
 277
 278         dev = cl->dev;
 279
 280         /* If Id is not asigned get one*/
 281         if (id == MEI_HOST_CLIENT_ID_ANY)
 282                 id = find_first_zero_bit(dev->host_clients_map,
 283                                         MEI_CLIENTS_MAX);
 284
 285         if (id >= MEI_CLIENTS_MAX) {
 286                 dev_err(&dev->pdev->dev, "id exceded %d", MEI_CLIENTS_MAX) ;
 287                 return -ENOENT;
 288         }
 289
 290         dev->open_handle_count++;
 291
 292         cl->host_client_id = id;
 293         list_add_tail(&cl->link, &dev->file_list);
 294
 295         set_bit(id, dev->host_clients_map);
 296
 297         cl->state = MEI_FILE_INITIALIZING;
 298
 299         dev_dbg(&dev->pdev->dev, "link cl host id = %d\n", cl->host_client_id);
 300         return 0;
 301 }
 302
 303 /**
 304  * mei_cl_unlink - remove me_cl from the list
 305  *
 306  * @cl: host client
 307  */
 308 int mei_cl_unlink(struct mei_cl *cl)
 309 {
 310         struct mei_device *dev;
 311         struct mei_cl *pos, *next;
 312
 313         /* don't shout on error exit path */
 314         if (!cl)
 315                 return 0;
 316
 317         /* wd and amthif might not be initialized */
 318         if (!cl->dev)
 319                 return 0;
 320
 321         dev = cl->dev;
 322
 323         list_for_each_entry_safe(pos, next, &dev->file_list, link) {
 324                 if (cl->host_client_id == pos->host_client_id) {
 325                         dev_dbg(&dev->pdev->dev, "remove host client = %d, ME client = %d\n",
 326                                 pos->host_client_id, pos->me_client_id);
 327                         list_del_init(&pos->link);
 328                         break;
 329                 }
 330         }
 331         return 0;
 332 }
 333
 334
 335 void mei_host_client_init(struct work_struct *work)
 336 {
 337         struct mei_device *dev = container_of(work,
 338                                               struct mei_device, init_work);
 339         struct mei_client_properties *client_props;
 340         int i;
 341
 342         mutex_lock(&dev->device_lock);
 343
 344         bitmap_zero(dev->host_clients_map, MEI_CLIENTS_MAX);
 345         dev->open_handle_count = 0;
 346
 347         /*
 348          * Reserving the first three client IDs
 349          * 0: Reserved for MEI Bus Message communications
 350          * 1: Reserved for Watchdog
 351          * 2: Reserved for AMTHI
 352          */
 353         bitmap_set(dev->host_clients_map, 0, 3);
 354
 355         for (i = 0; i < dev->me_clients_num; i++) {
 356                 client_props = &dev->me_clients[i].props;
 357
 358                 if (!uuid_le_cmp(client_props->protocol_name, mei_amthif_guid))
 359                         mei_amthif_host_init(dev);
 360                 else if (!uuid_le_cmp(client_props->protocol_name, mei_wd_guid))
 361                         mei_wd_host_init(dev);
 362                 else if (!uuid_le_cmp(client_props->protocol_name, mei_nfc_guid))
 363                         mei_nfc_host_init(dev);
 364
 365         }
 366
 367         dev->dev_state = MEI_DEV_ENABLED;
 368
 369         mutex_unlock(&dev->device_lock);
 370 }
 371
 372
 373 /**
 374  * mei_cl_disconnect - disconnect host clinet form the me one
 375  *
 376  * @cl: host client
 377  *
 378  * Locking: called under "dev->device_lock" lock
 379  *
 380  * returns 0 on success, <0 on failure.
 381  */
 382 int mei_cl_disconnect(struct mei_cl *cl)
 383 {
 384         struct mei_device *dev;
 385         struct mei_cl_cb *cb;
 386         int rets, err;
 387
 388         if (WARN_ON(!cl || !cl->dev))
 389                 return -ENODEV;
 390
 391         dev = cl->dev;
 392
 393         if (cl->state != MEI_FILE_DISCONNECTING)
 394                 return 0;
 395
 396         cb = mei_io_cb_init(cl, NULL);
 397         if (!cb)
 398                 return -ENOMEM;
 399
 400         cb->fop_type = MEI_FOP_CLOSE;
 401         if (dev->hbuf_is_ready) {
 402                 dev->hbuf_is_ready = false;
 403                 if (mei_hbm_cl_disconnect_req(dev, cl)) {
 404                         rets = -ENODEV;
 405                         dev_err(&dev->pdev->dev, "failed to disconnect.\n");
 406                         goto free;
 407                 }
 408                 mdelay(10); /* Wait for hardware disconnection ready */
 409                 list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
 410         } else {
 411                 dev_dbg(&dev->pdev->dev, "add disconnect cb to control write list\n");
 412                 list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
 413
 414         }
 415         mutex_unlock(&dev->device_lock);
 416
 417         err = wait_event_timeout(dev->wait_recvd_msg,
 418                         MEI_FILE_DISCONNECTED == cl->state,
 419                         mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT));
 420
 421         mutex_lock(&dev->device_lock);
 422         if (MEI_FILE_DISCONNECTED == cl->state) {
 423                 rets = 0;
 424                 dev_dbg(&dev->pdev->dev, "successfully disconnected from FW client.\n");
 425         } else {
 426                 rets = -ENODEV;
 427                 if (MEI_FILE_DISCONNECTED != cl->state)
 428                         dev_dbg(&dev->pdev->dev, "wrong status client disconnect.\n");
 429
 430                 if (err)
 431                         dev_dbg(&dev->pdev->dev,
 432                                         "wait failed disconnect err=%08x\n",
 433                                         err);
 434
 435                 dev_dbg(&dev->pdev->dev, "failed to disconnect from FW client.\n");
 436         }
 437
 438         mei_io_list_flush(&dev->ctrl_rd_list, cl);
 439         mei_io_list_flush(&dev->ctrl_wr_list, cl);
 440 free:
 441         mei_io_cb_free(cb);
 442         return rets;
 443 }
 444
 445
 446 /**
 447  * mei_cl_is_other_connecting - checks if other
 448  *    client with the same me client id is connecting
 449  *
 450  * @cl: private data of the file object
 451  *
 452  * returns ture if other client is connected, 0 - otherwise.
 453  */
 454 bool mei_cl_is_other_connecting(struct mei_cl *cl)
 455 {
 456         struct mei_device *dev;
 457         struct mei_cl *pos;
 458         struct mei_cl *next;
 459
 460         if (WARN_ON(!cl || !cl->dev))
 461                 return false;
 462
 463         dev = cl->dev;
 464
 465         list_for_each_entry_safe(pos, next, &dev->file_list, link) {
 466                 if ((pos->state == MEI_FILE_CONNECTING) &&
 467                     (pos != cl) && cl->me_client_id == pos->me_client_id)
 468                         return true;
 469
 470         }
 471
 472         return false;
 473 }
 474
 475 /**
 476  * mei_cl_connect - connect host clinet to the me one
 477  *
 478  * @cl: host client
 479  *
 480  * Locking: called under "dev->device_lock" lock
 481  *
 482  * returns 0 on success, <0 on failure.
 483  */
 484 int mei_cl_connect(struct mei_cl *cl, struct file *file)
 485 {
 486         struct mei_device *dev;
 487         struct mei_cl_cb *cb;
 488         long timeout = mei_secs_to_jiffies(MEI_CL_CONNECT_TIMEOUT);
 489         int rets;
 490
 491         if (WARN_ON(!cl || !cl->dev))
 492                 return -ENODEV;
 493
 494         dev = cl->dev;
 495
 496         cb = mei_io_cb_init(cl, file);
 497         if (!cb) {
 498                 rets = -ENOMEM;
 499                 goto out;
 500         }
 501
 502         cb->fop_type = MEI_FOP_IOCTL;
 503
 504         if (dev->hbuf_is_ready && !mei_cl_is_other_connecting(cl)) {
 505                 dev->hbuf_is_ready = false;
 506
 507                 if (mei_hbm_cl_connect_req(dev, cl)) {
 508                         rets = -ENODEV;
 509                         goto out;
 510                 }
 511                 cl->timer_count = MEI_CONNECT_TIMEOUT;
 512                 list_add_tail(&cb->list, &dev->ctrl_rd_list.list);
 513         } else {
 514                 list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
 515         }
 516
 517         mutex_unlock(&dev->device_lock);
 518         rets = wait_event_timeout(dev->wait_recvd_msg,
 519                                  (cl->state == MEI_FILE_CONNECTED ||
 520                                   cl->state == MEI_FILE_DISCONNECTED),
 521                                  timeout * HZ);
 522         mutex_lock(&dev->device_lock);
 523
 524         if (cl->state != MEI_FILE_CONNECTED) {
 525                 rets = -EFAULT;
 526
 527                 mei_io_list_flush(&dev->ctrl_rd_list, cl);
 528                 mei_io_list_flush(&dev->ctrl_wr_list, cl);
 529                 goto out;
 530         }
 531
 532         rets = cl->status;
 533
 534 out:
 535         mei_io_cb_free(cb);
 536         return rets;
 537 }
 538
 539 /**
 540  * mei_cl_flow_ctrl_creds - checks flow_control credits for cl.
 541  *
 542  * @cl: private data of the file object
 543  *
 544  * returns 1 if mei_flow_ctrl_creds >0, 0 - otherwise.
 545  *      -ENOENT if mei_cl is not present
 546  *      -EINVAL if single_recv_buf == 0
 547  */
 548 int mei_cl_flow_ctrl_creds(struct mei_cl *cl)
 549 {
 550         struct mei_device *dev;
 551         int i;
 552
 553         if (WARN_ON(!cl || !cl->dev))
 554                 return -EINVAL;
 555
 556         dev = cl->dev;
 557
 558         if (!dev->me_clients_num)
 559                 return 0;
 560
 561         if (cl->mei_flow_ctrl_creds > 0)
 562                 return 1;
 563
 564         for (i = 0; i < dev->me_clients_num; i++) {
 565                 struct mei_me_client  *me_cl = &dev->me_clients[i];
 566                 if (me_cl->client_id == cl->me_client_id) {
 567                         if (me_cl->mei_flow_ctrl_creds) {
 568                                 if (WARN_ON(me_cl->props.single_recv_buf == 0))
 569                                         return -EINVAL;
 570                                 return 1;
 571                         } else {
 572                                 return 0;
 573                         }
 574                 }
 575         }
 576         return -ENOENT;
 577 }
 578
 579 /**
 580  * mei_cl_flow_ctrl_reduce - reduces flow_control.
 581  *
 582  * @cl: private data of the file object
 583  *
 584  * @returns
 585  *      0 on success
 586  *      -ENOENT when me client is not found
 587  *      -EINVAL when ctrl credits are <= 0
 588  */
 589 int mei_cl_flow_ctrl_reduce(struct mei_cl *cl)
 590 {
 591         struct mei_device *dev;
 592         int i;
 593
 594         if (WARN_ON(!cl || !cl->dev))
 595                 return -EINVAL;
 596
 597         dev = cl->dev;
 598
 599         if (!dev->me_clients_num)
 600                 return -ENOENT;
 601
 602         for (i = 0; i < dev->me_clients_num; i++) {
 603                 struct mei_me_client  *me_cl = &dev->me_clients[i];
 604                 if (me_cl->client_id == cl->me_client_id) {
 605                         if (me_cl->props.single_recv_buf != 0) {
 606                                 if (WARN_ON(me_cl->mei_flow_ctrl_creds <= 0))
 607                                         return -EINVAL;
 608                                 dev->me_clients[i].mei_flow_ctrl_creds--;
 609                         } else {
 610                                 if (WARN_ON(cl->mei_flow_ctrl_creds <= 0))
 611                                         return -EINVAL;
 612                                 cl->mei_flow_ctrl_creds--;
 613                         }
 614                         return 0;
 615                 }
 616         }
 617         return -ENOENT;
 618 }
 619
 620 /**
 621  * mei_cl_read_start - the start read client message function.
 622  *
 623  * @cl: host client
 624  *
 625  * returns 0 on success, <0 on failure.
 626  */
 627 int mei_cl_read_start(struct mei_cl *cl, size_t length)
 628 {
 629         struct mei_device *dev;
 630         struct mei_cl_cb *cb;
 631         int rets;
 632         int i;
 633
 634         if (WARN_ON(!cl || !cl->dev))
 635                 return -ENODEV;
 636
 637         dev = cl->dev;
 638
 639         if (cl->state != MEI_FILE_CONNECTED)
 640                 return -ENODEV;
 641
 642         if (dev->dev_state != MEI_DEV_ENABLED)
 643                 return -ENODEV;
 644
 645         if (cl->read_cb) {
 646                 dev_dbg(&dev->pdev->dev, "read is pending.\n");
 647                 return -EBUSY;
 648         }
 649         i = mei_me_cl_by_id(dev, cl->me_client_id);
 650         if (i < 0) {
 651                 dev_err(&dev->pdev->dev, "no such me client %d\n",
 652                         cl->me_client_id);
 653                 return  -ENODEV;
 654         }
 655
 656         cb = mei_io_cb_init(cl, NULL);
 657         if (!cb)
 658                 return -ENOMEM;
 659
 660         /* always allocate at least client max message */
 661         length = max_t(size_t, length, dev->me_clients[i].props.max_msg_length);
 662         rets = mei_io_cb_alloc_resp_buf(cb, length);
 663         if (rets)
 664                 goto err;
 665
 666         cb->fop_type = MEI_FOP_READ;
 667         cl->read_cb = cb;
 668         if (dev->hbuf_is_ready) {
 669                 dev->hbuf_is_ready = false;
 670                 if (mei_hbm_cl_flow_control_req(dev, cl)) {
 671                         rets = -ENODEV;
 672                         goto err;
 673                 }
 674                 list_add_tail(&cb->list, &dev->read_list.list);
 675         } else {
 676                 list_add_tail(&cb->list, &dev->ctrl_wr_list.list);
 677         }
 678         return rets;
 679 err:
 680         mei_io_cb_free(cb);
 681         return rets;
 682 }
 683
 684 /**
 685  * mei_cl_write - submit a write cb to mei device
 686         assumes device_lock is locked
 687  *
 688  * @cl: host client
 689  * @cl: write callback with filled data
 690  *
 691  * returns numbe of bytes sent on success, <0 on failure.
 692  */
 693 int mei_cl_write(struct mei_cl *cl, struct mei_cl_cb *cb, bool blocking)
 694 {
 695         struct mei_device *dev;
 696         struct mei_msg_data *buf;
 697         struct mei_msg_hdr mei_hdr;
 698         int rets;
 699
 700
 701         if (WARN_ON(!cl || !cl->dev))
 702                 return -ENODEV;
 703
 704         if (WARN_ON(!cb))
 705                 return -EINVAL;
 706
 707         dev = cl->dev;
 708
 709
 710         buf = &cb->request_buffer;
 711
 712         dev_dbg(&dev->pdev->dev, "mei_cl_write %d\n", buf->size);
 713
 714
 715         cb->fop_type = MEI_FOP_WRITE;
 716
 717         rets = mei_cl_flow_ctrl_creds(cl);
 718         if (rets < 0)
 719                 goto err;
 720
 721         /* Host buffer is not ready, we queue the request */
 722         if (rets == 0 || !dev->hbuf_is_ready) {
 723                 cb->buf_idx = 0;
 724                 /* unseting complete will enqueue the cb for write */
 725                 mei_hdr.msg_complete = 0;
 726                 cl->writing_state = MEI_WRITING;
 727                 rets = buf->size;
 728                 goto out;
 729         }
 730
 731         dev->hbuf_is_ready = false;
 732
 733         /* Check for a maximum length */
 734         if (buf->size > mei_hbuf_max_len(dev)) {
 735                 mei_hdr.length = mei_hbuf_max_len(dev);
 736                 mei_hdr.msg_complete = 0;
 737         } else {
 738                 mei_hdr.length = buf->size;
 739                 mei_hdr.msg_complete = 1;
 740         }
 741
 742         mei_hdr.host_addr = cl->host_client_id;
 743         mei_hdr.me_addr = cl->me_client_id;
 744         mei_hdr.reserved = 0;
 745
 746         dev_dbg(&dev->pdev->dev, "write " MEI_HDR_FMT "\n",
 747                 MEI_HDR_PRM(&mei_hdr));
 748
 749
 750         if (mei_write_message(dev, &mei_hdr, buf->data)) {
 751                 rets = -EIO;
 752                 goto err;
 753         }
 754
 755         cl->writing_state = MEI_WRITING;
 756         cb->buf_idx = mei_hdr.length;
 757
 758         rets = buf->size;
 759 out:
 760         if (mei_hdr.msg_complete) {
 761                 if (mei_cl_flow_ctrl_reduce(cl)) {
 762                         rets = -ENODEV;
 763                         goto err;
 764                 }
 765                 list_add_tail(&cb->list, &dev->write_waiting_list.list);
 766         } else {
 767                 list_add_tail(&cb->list, &dev->write_list.list);
 768         }
 769
 770
 771         if (blocking && cl->writing_state != MEI_WRITE_COMPLETE) {
 772
 773                 mutex_unlock(&dev->device_lock);
 774                 if (wait_event_interruptible(cl->tx_wait,
 775                         cl->writing_state == MEI_WRITE_COMPLETE)) {
 776                                 if (signal_pending(current))
 777                                         rets = -EINTR;
 778                                 else
 779                                         rets = -ERESTARTSYS;
 780                 }
 781                 mutex_lock(&dev->device_lock);
 782         }
 783 err:
 784         return rets;
 785 }
 786
 787
 788
 789 /**
 790  * mei_cl_all_disconnect - disconnect forcefully all connected clients
 791  *
 792  * @dev - mei device
 793  */
 794
 795 void mei_cl_all_disconnect(struct mei_device *dev)
 796 {
 797         struct mei_cl *cl, *next;
 798
 799         list_for_each_entry_safe(cl, next, &dev->file_list, link) {
 800                 cl->state = MEI_FILE_DISCONNECTED;
 801                 cl->mei_flow_ctrl_creds = 0;
 802                 cl->read_cb = NULL;
 803                 cl->timer_count = 0;
 804         }
 805 }
 806
 807
 808 /**
 809  * mei_cl_all_read_wakeup  - wake up all readings so they can be interrupted
 810  *
 811  * @dev  - mei device
 812  */
 813 void mei_cl_all_read_wakeup(struct mei_device *dev)
 814 {
 815         struct mei_cl *cl, *next;
 816         list_for_each_entry_safe(cl, next, &dev->file_list, link) {
 817                 if (waitqueue_active(&cl->rx_wait)) {
 818                         dev_dbg(&dev->pdev->dev, "Waking up client!\n");
 819                         wake_up_interruptible(&cl->rx_wait);
 820                 }
 821         }
 822 }
 823
 824 /**
 825  * mei_cl_all_write_clear - clear all pending writes
 826
 827  * @dev - mei device
 828  */
 829 void mei_cl_all_write_clear(struct mei_device *dev)
 830 {
 831         struct mei_cl_cb *cb, *next;
 832
 833         list_for_each_entry_safe(cb, next, &dev->write_list.list, list) {
 834                 list_del(&cb->list);
 835                 mei_io_cb_free(cb);
 836         }
 837 }
 838
 839