drivers/staging/greybus/connection.c

   1 /*
   2  * Greybus connections
   3  *
   4  * Copyright 2014 Google Inc.
   5  * Copyright 2014 Linaro Ltd.
   6  *
   7  * Released under the GPLv2 only.
   8  */
   9
  10 #include <linux/workqueue.h>
  11
  12 #include "greybus.h"
  13 #include "greybus_trace.h"
  14
  15
  16 #define GB_CONNECTION_CPORT_QUIESCE_TIMEOUT     1000
  17
  18
  19 static void gb_connection_kref_release(struct kref *kref);
  20
  21
  22 static DEFINE_SPINLOCK(gb_connections_lock);
  23 static DEFINE_MUTEX(gb_connection_mutex);
  24
  25
  26 /* Caller holds gb_connection_mutex. */
  27 static bool gb_connection_cport_in_use(struct gb_interface *intf, u16 cport_id)
  28 {
  29         struct gb_host_device *hd = intf->hd;
  30         struct gb_connection *connection;
  31
  32         list_for_each_entry(connection, &hd->connections, hd_links) {
  33                 if (connection->intf == intf &&
  34                                 connection->intf_cport_id == cport_id)
  35                         return true;
  36         }
  37
  38         return false;
  39 }
  40
  41 static void gb_connection_get(struct gb_connection *connection)
  42 {
  43         kref_get(&connection->kref);
  44
  45         trace_gb_connection_get(connection);
  46 }
  47
  48 static void gb_connection_put(struct gb_connection *connection)
  49 {
  50         trace_gb_connection_put(connection);
  51
  52         kref_put(&connection->kref, gb_connection_kref_release);
  53 }
  54
  55 /*
  56  * Returns a reference-counted pointer to the connection if found.
  57  */
  58 static struct gb_connection *
  59 gb_connection_hd_find(struct gb_host_device *hd, u16 cport_id)
  60 {
  61         struct gb_connection *connection;
  62         unsigned long flags;
  63
  64         spin_lock_irqsave(&gb_connections_lock, flags);
  65         list_for_each_entry(connection, &hd->connections, hd_links)
  66                 if (connection->hd_cport_id == cport_id) {
  67                         gb_connection_get(connection);
  68                         goto found;
  69                 }
  70         connection = NULL;
  71 found:
  72         spin_unlock_irqrestore(&gb_connections_lock, flags);
  73
  74         return connection;
  75 }
  76
  77 /*
  78  * Callback from the host driver to let us know that data has been
  79  * received on the bundle.
  80  */
  81 void greybus_data_rcvd(struct gb_host_device *hd, u16 cport_id,
  82                         u8 *data, size_t length)
  83 {
  84         struct gb_connection *connection;
  85
  86         trace_gb_hd_in(hd);
  87
  88         connection = gb_connection_hd_find(hd, cport_id);
  89         if (!connection) {
  90                 dev_err(&hd->dev,
  91                         "nonexistent connection (%zu bytes dropped)\n", length);
  92                 return;
  93         }
  94         gb_connection_recv(connection, data, length);
  95         gb_connection_put(connection);
  96 }
  97 EXPORT_SYMBOL_GPL(greybus_data_rcvd);
  98
  99 static void gb_connection_kref_release(struct kref *kref)
 100 {
 101         struct gb_connection *connection;
 102
 103         connection = container_of(kref, struct gb_connection, kref);
 104
 105         trace_gb_connection_release(connection);
 106
 107         kfree(connection);
 108 }
 109
 110 static void gb_connection_init_name(struct gb_connection *connection)
 111 {
 112         u16 hd_cport_id = connection->hd_cport_id;
 113         u16 cport_id = 0;
 114         u8 intf_id = 0;
 115
 116         if (connection->intf) {
 117                 intf_id = connection->intf->interface_id;
 118                 cport_id = connection->intf_cport_id;
 119         }
 120
 121         snprintf(connection->name, sizeof(connection->name),
 122                         "%u/%u:%u", hd_cport_id, intf_id, cport_id);
 123 }
 124
 125 /*
 126  * _gb_connection_create() - create a Greybus connection
 127  * @hd:                 host device of the connection
 128  * @hd_cport_id:        host-device cport id, or -1 for dynamic allocation
 129  * @intf:               remote interface, or NULL for static connections
 130  * @bundle:             remote-interface bundle (may be NULL)
 131  * @cport_id:           remote-interface cport id, or 0 for static connections
 132  * @handler:            request handler (may be NULL)
 133  * @flags:              connection flags
 134  *
 135  * Create a Greybus connection, representing the bidirectional link
 136  * between a CPort on a (local) Greybus host device and a CPort on
 137  * another Greybus interface.
 138  *
 139  * A connection also maintains the state of operations sent over the
 140  * connection.
 141  *
 142  * Serialised against concurrent create and destroy using the
 143  * gb_connection_mutex.
 144  *
 145  * Return: A pointer to the new connection if successful, or an ERR_PTR
 146  * otherwise.
 147  */
 148 static struct gb_connection *
 149 _gb_connection_create(struct gb_host_device *hd, int hd_cport_id,
 150                                 struct gb_interface *intf,
 151                                 struct gb_bundle *bundle, int cport_id,
 152                                 gb_request_handler_t handler,
 153                                 unsigned long flags)
 154 {
 155         struct gb_connection *connection;
 156         int ret;
 157
 158         mutex_lock(&gb_connection_mutex);
 159
 160         if (intf && gb_connection_cport_in_use(intf, cport_id)) {
 161                 dev_err(&intf->dev, "cport %u already in use\n", cport_id);
 162                 ret = -EBUSY;
 163                 goto err_unlock;
 164         }
 165
 166         ret = gb_hd_cport_allocate(hd, hd_cport_id, flags);
 167         if (ret < 0) {
 168                 dev_err(&hd->dev, "failed to allocate cport: %d\n", ret);
 169                 goto err_unlock;
 170         }
 171         hd_cport_id = ret;
 172
 173         connection = kzalloc(sizeof(*connection), GFP_KERNEL);
 174         if (!connection) {
 175                 ret = -ENOMEM;
 176                 goto err_hd_cport_release;
 177         }
 178
 179         connection->hd_cport_id = hd_cport_id;
 180         connection->intf_cport_id = cport_id;
 181         connection->hd = hd;
 182         connection->intf = intf;
 183         connection->bundle = bundle;
 184         connection->handler = handler;
 185         connection->flags = flags;
 186         if (intf && (intf->quirks & GB_INTERFACE_QUIRK_NO_CPORT_FEATURES))
 187                 connection->flags |= GB_CONNECTION_FLAG_NO_FLOWCTRL;
 188         connection->state = GB_CONNECTION_STATE_DISABLED;
 189
 190         atomic_set(&connection->op_cycle, 0);
 191         mutex_init(&connection->mutex);
 192         spin_lock_init(&connection->lock);
 193         INIT_LIST_HEAD(&connection->operations);
 194
 195         connection->wq = alloc_workqueue("%s:%d", WQ_UNBOUND, 1,
 196                                          dev_name(&hd->dev), hd_cport_id);
 197         if (!connection->wq) {
 198                 ret = -ENOMEM;
 199                 goto err_free_connection;
 200         }
 201
 202         kref_init(&connection->kref);
 203
 204         gb_connection_init_name(connection);
 205
 206         spin_lock_irq(&gb_connections_lock);
 207         list_add(&connection->hd_links, &hd->connections);
 208
 209         if (bundle)
 210                 list_add(&connection->bundle_links, &bundle->connections);
 211         else
 212                 INIT_LIST_HEAD(&connection->bundle_links);
 213
 214         spin_unlock_irq(&gb_connections_lock);
 215
 216         mutex_unlock(&gb_connection_mutex);
 217
 218         trace_gb_connection_create(connection);
 219
 220         return connection;
 221
 222 err_free_connection:
 223         kfree(connection);
 224 err_hd_cport_release:
 225         gb_hd_cport_release(hd, hd_cport_id);
 226 err_unlock:
 227         mutex_unlock(&gb_connection_mutex);
 228
 229         return ERR_PTR(ret);
 230 }
 231
 232 struct gb_connection *
 233 gb_connection_create_static(struct gb_host_device *hd, u16 hd_cport_id,
 234                                         gb_request_handler_t handler)
 235 {
 236         return _gb_connection_create(hd, hd_cport_id, NULL, NULL, 0, handler,
 237                                         GB_CONNECTION_FLAG_HIGH_PRIO);
 238 }
 239
 240 struct gb_connection *
 241 gb_connection_create_control(struct gb_interface *intf)
 242 {
 243         return _gb_connection_create(intf->hd, -1, intf, NULL, 0, NULL,
 244                                         GB_CONNECTION_FLAG_CONTROL |
 245                                         GB_CONNECTION_FLAG_HIGH_PRIO);
 246 }
 247
 248 struct gb_connection *
 249 gb_connection_create(struct gb_bundle *bundle, u16 cport_id,
 250                                         gb_request_handler_t handler)
 251 {
 252         struct gb_interface *intf = bundle->intf;
 253
 254         return _gb_connection_create(intf->hd, -1, intf, bundle, cport_id,
 255                                         handler, 0);
 256 }
 257 EXPORT_SYMBOL_GPL(gb_connection_create);
 258
 259 struct gb_connection *
 260 gb_connection_create_flags(struct gb_bundle *bundle, u16 cport_id,
 261                                         gb_request_handler_t handler,
 262                                         unsigned long flags)
 263 {
 264         struct gb_interface *intf = bundle->intf;
 265
 266         if (WARN_ON_ONCE(flags & GB_CONNECTION_FLAG_CORE_MASK))
 267                 flags &= ~GB_CONNECTION_FLAG_CORE_MASK;
 268
 269         return _gb_connection_create(intf->hd, -1, intf, bundle, cport_id,
 270                                         handler, flags);
 271 }
 272 EXPORT_SYMBOL_GPL(gb_connection_create_flags);
 273
 274 struct gb_connection *
 275 gb_connection_create_offloaded(struct gb_bundle *bundle, u16 cport_id,
 276                                         unsigned long flags)
 277 {
 278         flags |= GB_CONNECTION_FLAG_OFFLOADED;
 279
 280         return gb_connection_create_flags(bundle, cport_id, NULL, flags);
 281 }
 282 EXPORT_SYMBOL_GPL(gb_connection_create_offloaded);
 283
 284 static int gb_connection_hd_cport_enable(struct gb_connection *connection)
 285 {
 286         struct gb_host_device *hd = connection->hd;
 287         int ret;
 288
 289         if (!hd->driver->cport_enable)
 290                 return 0;
 291
 292         ret = hd->driver->cport_enable(hd, connection->hd_cport_id,
 293                                         connection->flags);
 294         if (ret) {
 295                 dev_err(&hd->dev, "%s: failed to enable host cport: %d\n",
 296                                 connection->name, ret);
 297                 return ret;
 298         }
 299
 300         return 0;
 301 }
 302
 303 static void gb_connection_hd_cport_disable(struct gb_connection *connection)
 304 {
 305         struct gb_host_device *hd = connection->hd;
 306         int ret;
 307
 308         if (!hd->driver->cport_disable)
 309                 return;
 310
 311         ret = hd->driver->cport_disable(hd, connection->hd_cport_id);
 312         if (ret) {
 313                 dev_err(&hd->dev, "%s: failed to disable host cport: %d\n",
 314                                 connection->name, ret);
 315         }
 316 }
 317
 318 static int gb_connection_hd_cport_connected(struct gb_connection *connection)
 319 {
 320         struct gb_host_device *hd = connection->hd;
 321         int ret;
 322
 323         if (!hd->driver->cport_connected)
 324                 return 0;
 325
 326         ret = hd->driver->cport_connected(hd, connection->hd_cport_id);
 327         if (ret) {
 328                 dev_err(&hd->dev, "%s: failed to set connected state: %d\n",
 329                                 connection->name, ret);
 330                 return ret;
 331         }
 332
 333         return 0;
 334 }
 335
 336 static int gb_connection_hd_cport_flush(struct gb_connection *connection)
 337 {
 338         struct gb_host_device *hd = connection->hd;
 339         int ret;
 340
 341         if (!hd->driver->cport_flush)
 342                 return 0;
 343
 344         ret = hd->driver->cport_flush(hd, connection->hd_cport_id);
 345         if (ret) {
 346                 dev_err(&hd->dev, "%s: failed to flush host cport: %d\n",
 347                                 connection->name, ret);
 348                 return ret;
 349         }
 350
 351         return 0;
 352 }
 353
 354 static int gb_connection_hd_cport_quiesce(struct gb_connection *connection)
 355 {
 356         struct gb_host_device *hd = connection->hd;
 357         size_t peer_space;
 358         int ret;
 359
 360         if (!hd->driver->cport_quiesce)
 361                 return 0;
 362
 363         peer_space = sizeof(struct gb_operation_msg_hdr) +
 364                         sizeof(struct gb_cport_shutdown_request);
 365
 366         if (connection->mode_switch)
 367                 peer_space += sizeof(struct gb_operation_msg_hdr);
 368
 369         ret = hd->driver->cport_quiesce(hd, connection->hd_cport_id,
 370                                         peer_space,
 371                                         GB_CONNECTION_CPORT_QUIESCE_TIMEOUT);
 372         if (ret) {
 373                 dev_err(&hd->dev, "%s: failed to quiesce host cport: %d\n",
 374                                 connection->name, ret);
 375                 return ret;
 376         }
 377
 378         return 0;
 379 }
 380
 381 static int gb_connection_hd_cport_clear(struct gb_connection *connection)
 382 {
 383         struct gb_host_device *hd = connection->hd;
 384         int ret;
 385
 386         if (!hd->driver->cport_clear)
 387                 return 0;
 388
 389         ret = hd->driver->cport_clear(hd, connection->hd_cport_id);
 390         if (ret) {
 391                 dev_err(&hd->dev, "%s: failed to clear host cport: %d\n",
 392                                 connection->name, ret);
 393                 return ret;
 394         }
 395
 396         return 0;
 397 }
 398
 399 /*
 400  * Request the SVC to create a connection from AP's cport to interface's
 401  * cport.
 402  */
 403 static int
 404 gb_connection_svc_connection_create(struct gb_connection *connection)
 405 {
 406         struct gb_host_device *hd = connection->hd;
 407         struct gb_interface *intf;
 408         u8 cport_flags;
 409         int ret;
 410
 411         if (gb_connection_is_static(connection))
 412                 return 0;
 413
 414         intf = connection->intf;
 415
 416         /*
 417          * Enable either E2EFC or CSD, unless no flow control is requested.
 418          */
 419         cport_flags = GB_SVC_CPORT_FLAG_CSV_N;
 420         if (gb_connection_flow_control_disabled(connection)) {
 421                 cport_flags |= GB_SVC_CPORT_FLAG_CSD_N;
 422         } else if (gb_connection_e2efc_enabled(connection)) {
 423                 cport_flags |= GB_SVC_CPORT_FLAG_CSD_N |
 424                                 GB_SVC_CPORT_FLAG_E2EFC;
 425         }
 426
 427         ret = gb_svc_connection_create(hd->svc,
 428                         hd->svc->ap_intf_id,
 429                         connection->hd_cport_id,
 430                         intf->interface_id,
 431                         connection->intf_cport_id,
 432                         cport_flags);
 433         if (ret) {
 434                 dev_err(&connection->hd->dev,
 435                         "%s: failed to create svc connection: %d\n",
 436                         connection->name, ret);
 437                 return ret;
 438         }
 439
 440         return 0;
 441 }
 442
 443 static void
 444 gb_connection_svc_connection_destroy(struct gb_connection *connection)
 445 {
 446         if (gb_connection_is_static(connection))
 447                 return;
 448
 449         gb_svc_connection_destroy(connection->hd->svc,
 450                                   connection->hd->svc->ap_intf_id,
 451                                   connection->hd_cport_id,
 452                                   connection->intf->interface_id,
 453                                   connection->intf_cport_id);
 454 }
 455
 456 /* Inform Interface about active CPorts */
 457 static int gb_connection_control_connected(struct gb_connection *connection)
 458 {
 459         struct gb_control *control;
 460         u16 cport_id = connection->intf_cport_id;
 461         int ret;
 462
 463         if (gb_connection_is_static(connection))
 464                 return 0;
 465
 466         if (gb_connection_is_control(connection))
 467                 return 0;
 468
 469         control = connection->intf->control;
 470
 471         ret = gb_control_connected_operation(control, cport_id);
 472         if (ret) {
 473                 dev_err(&connection->bundle->dev,
 474                         "failed to connect cport: %d\n", ret);
 475                 return ret;
 476         }
 477
 478         return 0;
 479 }
 480
 481 static void
 482 gb_connection_control_disconnecting(struct gb_connection *connection)
 483 {
 484         struct gb_control *control;
 485         u16 cport_id = connection->intf_cport_id;
 486         int ret;
 487
 488         if (gb_connection_is_static(connection))
 489                 return;
 490
 491         control = connection->intf->control;
 492
 493         ret = gb_control_disconnecting_operation(control, cport_id);
 494         if (ret) {
 495                 dev_err(&connection->hd->dev,
 496                                 "%s: failed to send disconnecting: %d\n",
 497                                 connection->name, ret);
 498         }
 499 }
 500
 501 static void
 502 gb_connection_control_disconnected(struct gb_connection *connection)
 503 {
 504         struct gb_control *control;
 505         u16 cport_id = connection->intf_cport_id;
 506         int ret;
 507
 508         if (gb_connection_is_static(connection))
 509                 return;
 510
 511         control = connection->intf->control;
 512
 513         if (gb_connection_is_control(connection)) {
 514                 if (connection->mode_switch) {
 515                         ret = gb_control_mode_switch_operation(control);
 516                         if (ret) {
 517                                 /*
 518                                  * Allow mode switch to time out waiting for
 519                                  * mailbox event.
 520                                  */
 521                                 return;
 522                         }
 523                 }
 524
 525                 return;
 526         }
 527
 528         ret = gb_control_disconnected_operation(control, cport_id);
 529         if (ret) {
 530                 dev_warn(&connection->bundle->dev,
 531                          "failed to disconnect cport: %d\n", ret);
 532         }
 533 }
 534
 535 static int gb_connection_shutdown_operation(struct gb_connection *connection,
 536                                                 u8 phase)
 537 {
 538         struct gb_cport_shutdown_request *req;
 539         struct gb_operation *operation;
 540         int ret;
 541
 542         operation = gb_operation_create_core(connection,
 543                                                 GB_REQUEST_TYPE_CPORT_SHUTDOWN,
 544                                                 sizeof(*req), 0, 0,
 545                                                 GFP_KERNEL);
 546         if (!operation)
 547                 return -ENOMEM;
 548
 549         req = operation->request->payload;
 550         req->phase = phase;
 551
 552         ret = gb_operation_request_send_sync(operation);
 553
 554         gb_operation_put(operation);
 555
 556         return ret;
 557 }
 558
 559 static int gb_connection_cport_shutdown(struct gb_connection *connection,
 560                                         u8 phase)
 561 {
 562         struct gb_host_device *hd = connection->hd;
 563         const struct gb_hd_driver *drv = hd->driver;
 564         int ret;
 565
 566         if (gb_connection_is_static(connection))
 567                 return 0;
 568
 569         if (gb_connection_is_offloaded(connection)) {
 570                 if (!drv->cport_shutdown)
 571                         return 0;
 572
 573                 ret = drv->cport_shutdown(hd, connection->hd_cport_id, phase,
 574                                                 GB_OPERATION_TIMEOUT_DEFAULT);
 575         } else {
 576                 ret = gb_connection_shutdown_operation(connection, phase);
 577         }
 578
 579         if (ret) {
 580                 dev_err(&hd->dev, "%s: failed to send cport shutdown (phase %d): %d\n",
 581                                 connection->name, phase, ret);
 582                 return ret;
 583         }
 584
 585         return 0;
 586 }
 587
 588 static int
 589 gb_connection_cport_shutdown_phase_1(struct gb_connection *connection)
 590 {
 591         return gb_connection_cport_shutdown(connection, 1);
 592 }
 593
 594 static int
 595 gb_connection_cport_shutdown_phase_2(struct gb_connection *connection)
 596 {
 597         return gb_connection_cport_shutdown(connection, 2);
 598 }
 599
 600 /*
 601  * Cancel all active operations on a connection.
 602  *
 603  * Locking: Called with connection lock held and state set to DISABLED or
 604  * DISCONNECTING.
 605  */
 606 static void gb_connection_cancel_operations(struct gb_connection *connection,
 607                                                 int errno)
 608         __must_hold(&connection->lock)
 609 {
 610         struct gb_operation *operation;
 611
 612         while (!list_empty(&connection->operations)) {
 613                 operation = list_last_entry(&connection->operations,
 614                                                 struct gb_operation, links);
 615                 gb_operation_get(operation);
 616                 spin_unlock_irq(&connection->lock);
 617
 618                 if (gb_operation_is_incoming(operation))
 619                         gb_operation_cancel_incoming(operation, errno);
 620                 else
 621                         gb_operation_cancel(operation, errno);
 622
 623                 gb_operation_put(operation);
 624
 625                 spin_lock_irq(&connection->lock);
 626         }
 627 }
 628
 629 /*
 630  * Cancel all active incoming operations on a connection.
 631  *
 632  * Locking: Called with connection lock held and state set to ENABLED_TX.
 633  */
 634 static void
 635 gb_connection_flush_incoming_operations(struct gb_connection *connection,
 636                                                 int errno)
 637         __must_hold(&connection->lock)
 638 {
 639         struct gb_operation *operation;
 640         bool incoming;
 641
 642         while (!list_empty(&connection->operations)) {
 643                 incoming = false;
 644                 list_for_each_entry(operation, &connection->operations,
 645                                                                 links) {
 646                         if (gb_operation_is_incoming(operation)) {
 647                                 gb_operation_get(operation);
 648                                 incoming = true;
 649                                 break;
 650                         }
 651                 }
 652
 653                 if (!incoming)
 654                         break;
 655
 656                 spin_unlock_irq(&connection->lock);
 657
 658                 /* FIXME: flush, not cancel? */
 659                 gb_operation_cancel_incoming(operation, errno);
 660                 gb_operation_put(operation);
 661
 662                 spin_lock_irq(&connection->lock);
 663         }
 664 }
 665
 666 /*
 667  * _gb_connection_enable() - enable a connection
 668  * @connection:         connection to enable
 669  * @rx:                 whether to enable incoming requests
 670  *
 671  * Connection-enable helper for DISABLED->ENABLED, DISABLED->ENABLED_TX, and
 672  * ENABLED_TX->ENABLED state transitions.
 673  *
 674  * Locking: Caller holds connection->mutex.
 675  */
 676 static int _gb_connection_enable(struct gb_connection *connection, bool rx)
 677 {
 678         int ret;
 679
 680         /* Handle ENABLED_TX -> ENABLED transitions. */
 681         if (connection->state == GB_CONNECTION_STATE_ENABLED_TX) {
 682                 if (!(connection->handler && rx))
 683                         return 0;
 684
 685                 spin_lock_irq(&connection->lock);
 686                 connection->state = GB_CONNECTION_STATE_ENABLED;
 687                 spin_unlock_irq(&connection->lock);
 688
 689                 return 0;
 690         }
 691
 692         ret = gb_connection_hd_cport_enable(connection);
 693         if (ret)
 694                 return ret;
 695
 696         ret = gb_connection_svc_connection_create(connection);
 697         if (ret)
 698                 goto err_hd_cport_clear;
 699
 700         ret = gb_connection_hd_cport_connected(connection);
 701         if (ret)
 702                 goto err_svc_connection_destroy;
 703
 704         spin_lock_irq(&connection->lock);
 705         if (connection->handler && rx)
 706                 connection->state = GB_CONNECTION_STATE_ENABLED;
 707         else
 708                 connection->state = GB_CONNECTION_STATE_ENABLED_TX;
 709         spin_unlock_irq(&connection->lock);
 710
 711         ret = gb_connection_control_connected(connection);
 712         if (ret)
 713                 goto err_control_disconnecting;
 714
 715         return 0;
 716
 717 err_control_disconnecting:
 718         spin_lock_irq(&connection->lock);
 719         connection->state = GB_CONNECTION_STATE_DISCONNECTING;
 720         gb_connection_cancel_operations(connection, -ESHUTDOWN);
 721         spin_unlock_irq(&connection->lock);
 722
 723         /* Transmit queue should already be empty. */
 724         gb_connection_hd_cport_flush(connection);
 725
 726         gb_connection_control_disconnecting(connection);
 727         gb_connection_cport_shutdown_phase_1(connection);
 728         gb_connection_hd_cport_quiesce(connection);
 729         gb_connection_cport_shutdown_phase_2(connection);
 730         gb_connection_control_disconnected(connection);
 731         connection->state = GB_CONNECTION_STATE_DISABLED;
 732 err_svc_connection_destroy:
 733         gb_connection_svc_connection_destroy(connection);
 734 err_hd_cport_clear:
 735         gb_connection_hd_cport_clear(connection);
 736
 737         gb_connection_hd_cport_disable(connection);
 738
 739         return ret;
 740 }
 741
 742 int gb_connection_enable(struct gb_connection *connection)
 743 {
 744         int ret = 0;
 745
 746         mutex_lock(&connection->mutex);
 747
 748         if (connection->state == GB_CONNECTION_STATE_ENABLED)
 749                 goto out_unlock;
 750
 751         ret = _gb_connection_enable(connection, true);
 752         if (!ret)
 753                 trace_gb_connection_enable(connection);
 754
 755 out_unlock:
 756         mutex_unlock(&connection->mutex);
 757
 758         return ret;
 759 }
 760 EXPORT_SYMBOL_GPL(gb_connection_enable);
 761
 762 int gb_connection_enable_tx(struct gb_connection *connection)
 763 {
 764         int ret = 0;
 765
 766         mutex_lock(&connection->mutex);
 767
 768         if (connection->state == GB_CONNECTION_STATE_ENABLED) {
 769                 ret = -EINVAL;
 770                 goto out_unlock;
 771         }
 772
 773         if (connection->state == GB_CONNECTION_STATE_ENABLED_TX)
 774                 goto out_unlock;
 775
 776         ret = _gb_connection_enable(connection, false);
 777         if (!ret)
 778                 trace_gb_connection_enable(connection);
 779
 780 out_unlock:
 781         mutex_unlock(&connection->mutex);
 782
 783         return ret;
 784 }
 785 EXPORT_SYMBOL_GPL(gb_connection_enable_tx);
 786
 787 void gb_connection_disable_rx(struct gb_connection *connection)
 788 {
 789         mutex_lock(&connection->mutex);
 790
 791         spin_lock_irq(&connection->lock);
 792         if (connection->state != GB_CONNECTION_STATE_ENABLED) {
 793                 spin_unlock_irq(&connection->lock);
 794                 goto out_unlock;
 795         }
 796         connection->state = GB_CONNECTION_STATE_ENABLED_TX;
 797         gb_connection_flush_incoming_operations(connection, -ESHUTDOWN);
 798         spin_unlock_irq(&connection->lock);
 799
 800         trace_gb_connection_disable(connection);
 801
 802 out_unlock:
 803         mutex_unlock(&connection->mutex);
 804 }
 805 EXPORT_SYMBOL_GPL(gb_connection_disable_rx);
 806
 807 void gb_connection_mode_switch_prepare(struct gb_connection *connection)
 808 {
 809         connection->mode_switch = true;
 810 }
 811
 812 void gb_connection_mode_switch_complete(struct gb_connection *connection)
 813 {
 814         gb_connection_svc_connection_destroy(connection);
 815         gb_connection_hd_cport_clear(connection);
 816
 817         gb_connection_hd_cport_disable(connection);
 818
 819         connection->mode_switch = false;
 820 }
 821
 822 void gb_connection_disable(struct gb_connection *connection)
 823 {
 824         mutex_lock(&connection->mutex);
 825
 826         if (connection->state == GB_CONNECTION_STATE_DISABLED)
 827                 goto out_unlock;
 828
 829         trace_gb_connection_disable(connection);
 830
 831         spin_lock_irq(&connection->lock);
 832         connection->state = GB_CONNECTION_STATE_DISCONNECTING;
 833         gb_connection_cancel_operations(connection, -ESHUTDOWN);
 834         spin_unlock_irq(&connection->lock);
 835
 836         gb_connection_hd_cport_flush(connection);
 837
 838         gb_connection_control_disconnecting(connection);
 839         gb_connection_cport_shutdown_phase_1(connection);
 840         gb_connection_hd_cport_quiesce(connection);
 841         gb_connection_cport_shutdown_phase_2(connection);
 842         gb_connection_control_disconnected(connection);
 843
 844         connection->state = GB_CONNECTION_STATE_DISABLED;
 845
 846         /* control-connection tear down is deferred when mode switching */
 847         if (!connection->mode_switch) {
 848                 gb_connection_svc_connection_destroy(connection);
 849                 gb_connection_hd_cport_clear(connection);
 850
 851                 gb_connection_hd_cport_disable(connection);
 852         }
 853
 854 out_unlock:
 855         mutex_unlock(&connection->mutex);
 856 }
 857 EXPORT_SYMBOL_GPL(gb_connection_disable);
 858
 859 /* Disable a connection without communicating with the remote end. */
 860 void gb_connection_disable_forced(struct gb_connection *connection)
 861 {
 862         mutex_lock(&connection->mutex);
 863
 864         if (connection->state == GB_CONNECTION_STATE_DISABLED)
 865                 goto out_unlock;
 866
 867         trace_gb_connection_disable(connection);
 868
 869         spin_lock_irq(&connection->lock);
 870         connection->state = GB_CONNECTION_STATE_DISABLED;
 871         gb_connection_cancel_operations(connection, -ESHUTDOWN);
 872         spin_unlock_irq(&connection->lock);
 873
 874         gb_connection_hd_cport_flush(connection);
 875
 876         gb_connection_svc_connection_destroy(connection);
 877         gb_connection_hd_cport_clear(connection);
 878
 879         gb_connection_hd_cport_disable(connection);
 880 out_unlock:
 881         mutex_unlock(&connection->mutex);
 882 }
 883 EXPORT_SYMBOL_GPL(gb_connection_disable_forced);
 884
 885 /* Caller must have disabled the connection before destroying it. */
 886 void gb_connection_destroy(struct gb_connection *connection)
 887 {
 888         if (!connection)
 889                 return;
 890
 891         if (WARN_ON(connection->state != GB_CONNECTION_STATE_DISABLED))
 892                 gb_connection_disable(connection);
 893
 894         mutex_lock(&gb_connection_mutex);
 895
 896         spin_lock_irq(&gb_connections_lock);
 897         list_del(&connection->bundle_links);
 898         list_del(&connection->hd_links);
 899         spin_unlock_irq(&gb_connections_lock);
 900
 901         destroy_workqueue(connection->wq);
 902
 903         gb_hd_cport_release(connection->hd, connection->hd_cport_id);
 904         connection->hd_cport_id = CPORT_ID_BAD;
 905
 906         mutex_unlock(&gb_connection_mutex);
 907
 908         gb_connection_put(connection);
 909 }
 910 EXPORT_SYMBOL_GPL(gb_connection_destroy);
 911
 912 void gb_connection_latency_tag_enable(struct gb_connection *connection)
 913 {
 914         struct gb_host_device *hd = connection->hd;
 915         int ret;
 916
 917         if (!hd->driver->latency_tag_enable)
 918                 return;
 919
 920         ret = hd->driver->latency_tag_enable(hd, connection->hd_cport_id);
 921         if (ret) {
 922                 dev_err(&connection->hd->dev,
 923                         "%s: failed to enable latency tag: %d\n",
 924                         connection->name, ret);
 925         }
 926 }
 927 EXPORT_SYMBOL_GPL(gb_connection_latency_tag_enable);
 928
 929 void gb_connection_latency_tag_disable(struct gb_connection *connection)
 930 {
 931         struct gb_host_device *hd = connection->hd;
 932         int ret;
 933
 934         if (!hd->driver->latency_tag_disable)
 935                 return;
 936
 937         ret = hd->driver->latency_tag_disable(hd, connection->hd_cport_id);
 938         if (ret) {
 939                 dev_err(&connection->hd->dev,
 940                         "%s: failed to disable latency tag: %d\n",
 941                         connection->name, ret);
 942         }
 943 }
 944 EXPORT_SYMBOL_GPL(gb_connection_latency_tag_disable);