drivers/thunderbolt/tb.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Thunderbolt driver - bus logic (NHI independent)
   4  *
   5  * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
   6  * Copyright (C) 2019, Intel Corporation
   7  */
   8
   9 #include <linux/slab.h>
  10 #include <linux/errno.h>
  11 #include <linux/delay.h>
  12
  13 #include "tb.h"
  14 #include "tb_regs.h"
  15 #include "tunnel.h"
  16
  17 /**
  18  * struct tb_cm - Simple Thunderbolt connection manager
  19  * @tunnel_list: List of active tunnels
  20  * @dp_resources: List of available DP resources for DP tunneling
  21  * @hotplug_active: tb_handle_hotplug will stop progressing plug
  22  *                  events and exit if this is not set (it needs to
  23  *                  acquire the lock one more time). Used to drain wq
  24  *                  after cfg has been paused.
  25  */
  26 struct tb_cm {
  27         struct list_head tunnel_list;
  28         struct list_head dp_resources;
  29         bool hotplug_active;
  30 };
  31
  32 struct tb_hotplug_event {
  33         struct work_struct work;
  34         struct tb *tb;
  35         u64 route;
  36         u8 port;
  37         bool unplug;
  38 };
  39
  40 static void tb_handle_hotplug(struct work_struct *work);
  41
  42 static void tb_queue_hotplug(struct tb *tb, u64 route, u8 port, bool unplug)
  43 {
  44         struct tb_hotplug_event *ev;
  45
  46         ev = kmalloc(sizeof(*ev), GFP_KERNEL);
  47         if (!ev)
  48                 return;
  49
  50         ev->tb = tb;
  51         ev->route = route;
  52         ev->port = port;
  53         ev->unplug = unplug;
  54         INIT_WORK(&ev->work, tb_handle_hotplug);
  55         queue_work(tb->wq, &ev->work);
  56 }
  57
  58 /* enumeration & hot plug handling */
  59
  60 static void tb_add_dp_resources(struct tb_switch *sw)
  61 {
  62         struct tb_cm *tcm = tb_priv(sw->tb);
  63         struct tb_port *port;
  64
  65         tb_switch_for_each_port(sw, port) {
  66                 if (!tb_port_is_dpin(port))
  67                         continue;
  68
  69                 if (!tb_switch_query_dp_resource(sw, port))
  70                         continue;
  71
  72                 list_add_tail(&port->list, &tcm->dp_resources);
  73                 tb_port_dbg(port, "DP IN resource available\n");
  74         }
  75 }
  76
  77 static void tb_remove_dp_resources(struct tb_switch *sw)
  78 {
  79         struct tb_cm *tcm = tb_priv(sw->tb);
  80         struct tb_port *port, *tmp;
  81
  82         /* Clear children resources first */
  83         tb_switch_for_each_port(sw, port) {
  84                 if (tb_port_has_remote(port))
  85                         tb_remove_dp_resources(port->remote->sw);
  86         }
  87
  88         list_for_each_entry_safe(port, tmp, &tcm->dp_resources, list) {
  89                 if (port->sw == sw) {
  90                         tb_port_dbg(port, "DP OUT resource unavailable\n");
  91                         list_del_init(&port->list);
  92                 }
  93         }
  94 }
  95
  96 static void tb_discover_tunnels(struct tb_switch *sw)
  97 {
  98         struct tb *tb = sw->tb;
  99         struct tb_cm *tcm = tb_priv(tb);
 100         struct tb_port *port;
 101
 102         tb_switch_for_each_port(sw, port) {
 103                 struct tb_tunnel *tunnel = NULL;
 104
 105                 switch (port->config.type) {
 106                 case TB_TYPE_DP_HDMI_IN:
 107                         tunnel = tb_tunnel_discover_dp(tb, port);
 108                         break;
 109
 110                 case TB_TYPE_PCIE_DOWN:
 111                         tunnel = tb_tunnel_discover_pci(tb, port);
 112                         break;
 113
 114                 default:
 115                         break;
 116                 }
 117
 118                 if (!tunnel)
 119                         continue;
 120
 121                 if (tb_tunnel_is_pci(tunnel)) {
 122                         struct tb_switch *parent = tunnel->dst_port->sw;
 123
 124                         while (parent != tunnel->src_port->sw) {
 125                                 parent->boot = true;
 126                                 parent = tb_switch_parent(parent);
 127                         }
 128                 }
 129
 130                 list_add_tail(&tunnel->list, &tcm->tunnel_list);
 131         }
 132
 133         tb_switch_for_each_port(sw, port) {
 134                 if (tb_port_has_remote(port))
 135                         tb_discover_tunnels(port->remote->sw);
 136         }
 137 }
 138
 139 static void tb_scan_xdomain(struct tb_port *port)
 140 {
 141         struct tb_switch *sw = port->sw;
 142         struct tb *tb = sw->tb;
 143         struct tb_xdomain *xd;
 144         u64 route;
 145
 146         route = tb_downstream_route(port);
 147         xd = tb_xdomain_find_by_route(tb, route);
 148         if (xd) {
 149                 tb_xdomain_put(xd);
 150                 return;
 151         }
 152
 153         xd = tb_xdomain_alloc(tb, &sw->dev, route, tb->root_switch->uuid,
 154                               NULL);
 155         if (xd) {
 156                 tb_port_at(route, sw)->xdomain = xd;
 157                 tb_xdomain_add(xd);
 158         }
 159 }
 160
 161 static void tb_scan_port(struct tb_port *port);
 162
 163 /**
 164  * tb_scan_switch() - scan for and initialize downstream switches
 165  */
 166 static void tb_scan_switch(struct tb_switch *sw)
 167 {
 168         struct tb_port *port;
 169
 170         tb_switch_for_each_port(sw, port)
 171                 tb_scan_port(port);
 172 }
 173
 174 /**
 175  * tb_scan_port() - check for and initialize switches below port
 176  */
 177 static void tb_scan_port(struct tb_port *port)
 178 {
 179         struct tb_cm *tcm = tb_priv(port->sw->tb);
 180         struct tb_port *upstream_port;
 181         struct tb_switch *sw;
 182
 183         if (tb_is_upstream_port(port))
 184                 return;
 185
 186         if (tb_port_is_dpout(port) && tb_dp_port_hpd_is_active(port) == 1 &&
 187             !tb_dp_port_is_enabled(port)) {
 188                 tb_port_dbg(port, "DP adapter HPD set, queuing hotplug\n");
 189                 tb_queue_hotplug(port->sw->tb, tb_route(port->sw), port->port,
 190                                  false);
 191                 return;
 192         }
 193
 194         if (port->config.type != TB_TYPE_PORT)
 195                 return;
 196         if (port->dual_link_port && port->link_nr)
 197                 return; /*
 198                          * Downstream switch is reachable through two ports.
 199                          * Only scan on the primary port (link_nr == 0).
 200                          */
 201         if (tb_wait_for_port(port, false) <= 0)
 202                 return;
 203         if (port->remote) {
 204                 tb_port_dbg(port, "port already has a remote\n");
 205                 return;
 206         }
 207         sw = tb_switch_alloc(port->sw->tb, &port->sw->dev,
 208                              tb_downstream_route(port));
 209         if (IS_ERR(sw)) {
 210                 /*
 211                  * If there is an error accessing the connected switch
 212                  * it may be connected to another domain. Also we allow
 213                  * the other domain to be connected to a max depth switch.
 214                  */
 215                 if (PTR_ERR(sw) == -EIO || PTR_ERR(sw) == -EADDRNOTAVAIL)
 216                         tb_scan_xdomain(port);
 217                 return;
 218         }
 219
 220         if (tb_switch_configure(sw)) {
 221                 tb_switch_put(sw);
 222                 return;
 223         }
 224
 225         /*
 226          * If there was previously another domain connected remove it
 227          * first.
 228          */
 229         if (port->xdomain) {
 230                 tb_xdomain_remove(port->xdomain);
 231                 port->xdomain = NULL;
 232         }
 233
 234         /*
 235          * Do not send uevents until we have discovered all existing
 236          * tunnels and know which switches were authorized already by
 237          * the boot firmware.
 238          */
 239         if (!tcm->hotplug_active)
 240                 dev_set_uevent_suppress(&sw->dev, true);
 241
 242         if (tb_switch_add(sw)) {
 243                 tb_switch_put(sw);
 244                 return;
 245         }
 246
 247         /* Link the switches using both links if available */
 248         upstream_port = tb_upstream_port(sw);
 249         port->remote = upstream_port;
 250         upstream_port->remote = port;
 251         if (port->dual_link_port && upstream_port->dual_link_port) {
 252                 port->dual_link_port->remote = upstream_port->dual_link_port;
 253                 upstream_port->dual_link_port->remote = port->dual_link_port;
 254         }
 255
 256         /* Enable lane bonding if supported */
 257         if (tb_switch_lane_bonding_enable(sw))
 258                 tb_sw_warn(sw, "failed to enable lane bonding\n");
 259
 260         tb_scan_switch(sw);
 261 }
 262
 263 static struct tb_tunnel *tb_find_tunnel(struct tb *tb, enum tb_tunnel_type type,
 264                                         struct tb_port *src_port,
 265                                         struct tb_port *dst_port)
 266 {
 267         struct tb_cm *tcm = tb_priv(tb);
 268         struct tb_tunnel *tunnel;
 269
 270         list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
 271                 if (tunnel->type == type &&
 272                     ((src_port && src_port == tunnel->src_port) ||
 273                      (dst_port && dst_port == tunnel->dst_port))) {
 274                         return tunnel;
 275                 }
 276         }
 277
 278         return NULL;
 279 }
 280
 281 static void tb_deactivate_and_free_tunnel(struct tb_tunnel *tunnel)
 282 {
 283         if (!tunnel)
 284                 return;
 285
 286         tb_tunnel_deactivate(tunnel);
 287         list_del(&tunnel->list);
 288
 289         /*
 290          * In case of DP tunnel make sure the DP IN resource is deallocated
 291          * properly.
 292          */
 293         if (tb_tunnel_is_dp(tunnel)) {
 294                 struct tb_port *in = tunnel->src_port;
 295
 296                 tb_switch_dealloc_dp_resource(in->sw, in);
 297         }
 298
 299         tb_tunnel_free(tunnel);
 300 }
 301
 302 /**
 303  * tb_free_invalid_tunnels() - destroy tunnels of devices that have gone away
 304  */
 305 static void tb_free_invalid_tunnels(struct tb *tb)
 306 {
 307         struct tb_cm *tcm = tb_priv(tb);
 308         struct tb_tunnel *tunnel;
 309         struct tb_tunnel *n;
 310
 311         list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
 312                 if (tb_tunnel_is_invalid(tunnel))
 313                         tb_deactivate_and_free_tunnel(tunnel);
 314         }
 315 }
 316
 317 /**
 318  * tb_free_unplugged_children() - traverse hierarchy and free unplugged switches
 319  */
 320 static void tb_free_unplugged_children(struct tb_switch *sw)
 321 {
 322         struct tb_port *port;
 323
 324         tb_switch_for_each_port(sw, port) {
 325                 if (!tb_port_has_remote(port))
 326                         continue;
 327
 328                 if (port->remote->sw->is_unplugged) {
 329                         tb_remove_dp_resources(port->remote->sw);
 330                         tb_switch_lane_bonding_disable(port->remote->sw);
 331                         tb_switch_remove(port->remote->sw);
 332                         port->remote = NULL;
 333                         if (port->dual_link_port)
 334                                 port->dual_link_port->remote = NULL;
 335                 } else {
 336                         tb_free_unplugged_children(port->remote->sw);
 337                 }
 338         }
 339 }
 340
 341 /**
 342  * tb_find_unused_port() - return the first inactive port on @sw
 343  * @sw: Switch to find the port on
 344  * @type: Port type to look for
 345  */
 346 static struct tb_port *tb_find_unused_port(struct tb_switch *sw,
 347                                            enum tb_port_type type)
 348 {
 349         struct tb_port *port;
 350
 351         tb_switch_for_each_port(sw, port) {
 352                 if (tb_is_upstream_port(port))
 353                         continue;
 354                 if (port->config.type != type)
 355                         continue;
 356                 if (port->cap_adap)
 357                         continue;
 358                 if (tb_port_is_enabled(port))
 359                         continue;
 360                 return port;
 361         }
 362         return NULL;
 363 }
 364
 365 static struct tb_port *tb_find_pcie_down(struct tb_switch *sw,
 366                                          const struct tb_port *port)
 367 {
 368         /*
 369          * To keep plugging devices consistently in the same PCIe
 370          * hierarchy, do mapping here for root switch downstream PCIe
 371          * ports.
 372          */
 373         if (!tb_route(sw)) {
 374                 int phy_port = tb_phy_port_from_link(port->port);
 375                 int index;
 376
 377                 /*
 378                  * Hard-coded Thunderbolt port to PCIe down port mapping
 379                  * per controller.
 380                  */
 381                 if (tb_switch_is_cactus_ridge(sw) ||
 382                     tb_switch_is_alpine_ridge(sw))
 383                         index = !phy_port ? 6 : 7;
 384                 else if (tb_switch_is_falcon_ridge(sw))
 385                         index = !phy_port ? 6 : 8;
 386                 else if (tb_switch_is_titan_ridge(sw))
 387                         index = !phy_port ? 8 : 9;
 388                 else
 389                         goto out;
 390
 391                 /* Validate the hard-coding */
 392                 if (WARN_ON(index > sw->config.max_port_number))
 393                         goto out;
 394                 if (WARN_ON(!tb_port_is_pcie_down(&sw->ports[index])))
 395                         goto out;
 396                 if (WARN_ON(tb_pci_port_is_enabled(&sw->ports[index])))
 397                         goto out;
 398
 399                 return &sw->ports[index];
 400         }
 401
 402 out:
 403         return tb_find_unused_port(sw, TB_TYPE_PCIE_DOWN);
 404 }
 405
 406 static int tb_available_bw(struct tb_cm *tcm, struct tb_port *in,
 407                            struct tb_port *out)
 408 {
 409         struct tb_switch *sw = out->sw;
 410         struct tb_tunnel *tunnel;
 411         int bw, available_bw = 40000;
 412
 413         while (sw && sw != in->sw) {
 414                 bw = sw->link_speed * sw->link_width * 1000; /* Mb/s */
 415                 /* Leave 10% guard band */
 416                 bw -= bw / 10;
 417
 418                 /*
 419                  * Check for any active DP tunnels that go through this
 420                  * switch and reduce their consumed bandwidth from
 421                  * available.
 422                  */
 423                 list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
 424                         int consumed_bw;
 425
 426                         if (!tb_tunnel_switch_on_path(tunnel, sw))
 427                                 continue;
 428
 429                         consumed_bw = tb_tunnel_consumed_bandwidth(tunnel);
 430                         if (consumed_bw < 0)
 431                                 return consumed_bw;
 432
 433                         bw -= consumed_bw;
 434                 }
 435
 436                 if (bw < available_bw)
 437                         available_bw = bw;
 438
 439                 sw = tb_switch_parent(sw);
 440         }
 441
 442         return available_bw;
 443 }
 444
 445 static void tb_tunnel_dp(struct tb *tb)
 446 {
 447         struct tb_cm *tcm = tb_priv(tb);
 448         struct tb_port *port, *in, *out;
 449         struct tb_tunnel *tunnel;
 450         int available_bw;
 451
 452         /*
 453          * Find pair of inactive DP IN and DP OUT adapters and then
 454          * establish a DP tunnel between them.
 455          */
 456         tb_dbg(tb, "looking for DP IN <-> DP OUT pairs:\n");
 457
 458         in = NULL;
 459         out = NULL;
 460         list_for_each_entry(port, &tcm->dp_resources, list) {
 461                 if (tb_port_is_enabled(port)) {
 462                         tb_port_dbg(port, "in use\n");
 463                         continue;
 464                 }
 465
 466                 tb_port_dbg(port, "available\n");
 467
 468                 if (!in && tb_port_is_dpin(port))
 469                         in = port;
 470                 else if (!out && tb_port_is_dpout(port))
 471                         out = port;
 472         }
 473
 474         if (!in) {
 475                 tb_dbg(tb, "no suitable DP IN adapter available, not tunneling\n");
 476                 return;
 477         }
 478         if (!out) {
 479                 tb_dbg(tb, "no suitable DP OUT adapter available, not tunneling\n");
 480                 return;
 481         }
 482
 483         if (tb_switch_alloc_dp_resource(in->sw, in)) {
 484                 tb_port_dbg(in, "no resource available for DP IN, not tunneling\n");
 485                 return;
 486         }
 487
 488         /* Calculate available bandwidth between in and out */
 489         available_bw = tb_available_bw(tcm, in, out);
 490         if (available_bw < 0) {
 491                 tb_warn(tb, "failed to determine available bandwidth\n");
 492                 return;
 493         }
 494
 495         tb_dbg(tb, "available bandwidth for new DP tunnel %u Mb/s\n",
 496                available_bw);
 497
 498         tunnel = tb_tunnel_alloc_dp(tb, in, out, available_bw);
 499         if (!tunnel) {
 500                 tb_port_dbg(out, "could not allocate DP tunnel\n");
 501                 goto dealloc_dp;
 502         }
 503
 504         if (tb_tunnel_activate(tunnel)) {
 505                 tb_port_info(out, "DP tunnel activation failed, aborting\n");
 506                 tb_tunnel_free(tunnel);
 507                 goto dealloc_dp;
 508         }
 509
 510         list_add_tail(&tunnel->list, &tcm->tunnel_list);
 511         return;
 512
 513 dealloc_dp:
 514         tb_switch_dealloc_dp_resource(in->sw, in);
 515 }
 516
 517 static void tb_dp_resource_unavailable(struct tb *tb, struct tb_port *port)
 518 {
 519         struct tb_port *in, *out;
 520         struct tb_tunnel *tunnel;
 521
 522         if (tb_port_is_dpin(port)) {
 523                 tb_port_dbg(port, "DP IN resource unavailable\n");
 524                 in = port;
 525                 out = NULL;
 526         } else {
 527                 tb_port_dbg(port, "DP OUT resource unavailable\n");
 528                 in = NULL;
 529                 out = port;
 530         }
 531
 532         tunnel = tb_find_tunnel(tb, TB_TUNNEL_DP, in, out);
 533         tb_deactivate_and_free_tunnel(tunnel);
 534         list_del_init(&port->list);
 535
 536         /*
 537          * See if there is another DP OUT port that can be used for
 538          * to create another tunnel.
 539          */
 540         tb_tunnel_dp(tb);
 541 }
 542
 543 static void tb_dp_resource_available(struct tb *tb, struct tb_port *port)
 544 {
 545         struct tb_cm *tcm = tb_priv(tb);
 546         struct tb_port *p;
 547
 548         if (tb_port_is_enabled(port))
 549                 return;
 550
 551         list_for_each_entry(p, &tcm->dp_resources, list) {
 552                 if (p == port)
 553                         return;
 554         }
 555
 556         tb_port_dbg(port, "DP %s resource available\n",
 557                     tb_port_is_dpin(port) ? "IN" : "OUT");
 558         list_add_tail(&port->list, &tcm->dp_resources);
 559
 560         /* Look for suitable DP IN <-> DP OUT pairs now */
 561         tb_tunnel_dp(tb);
 562 }
 563
 564 static int tb_tunnel_pci(struct tb *tb, struct tb_switch *sw)
 565 {
 566         struct tb_port *up, *down, *port;
 567         struct tb_cm *tcm = tb_priv(tb);
 568         struct tb_switch *parent_sw;
 569         struct tb_tunnel *tunnel;
 570
 571         up = tb_switch_find_port(sw, TB_TYPE_PCIE_UP);
 572         if (!up)
 573                 return 0;
 574
 575         /*
 576          * Look up available down port. Since we are chaining it should
 577          * be found right above this switch.
 578          */
 579         parent_sw = tb_to_switch(sw->dev.parent);
 580         port = tb_port_at(tb_route(sw), parent_sw);
 581         down = tb_find_pcie_down(parent_sw, port);
 582         if (!down)
 583                 return 0;
 584
 585         tunnel = tb_tunnel_alloc_pci(tb, up, down);
 586         if (!tunnel)
 587                 return -ENOMEM;
 588
 589         if (tb_tunnel_activate(tunnel)) {
 590                 tb_port_info(up,
 591                              "PCIe tunnel activation failed, aborting\n");
 592                 tb_tunnel_free(tunnel);
 593                 return -EIO;
 594         }
 595
 596         list_add_tail(&tunnel->list, &tcm->tunnel_list);
 597         return 0;
 598 }
 599
 600 static int tb_approve_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
 601 {
 602         struct tb_cm *tcm = tb_priv(tb);
 603         struct tb_port *nhi_port, *dst_port;
 604         struct tb_tunnel *tunnel;
 605         struct tb_switch *sw;
 606
 607         sw = tb_to_switch(xd->dev.parent);
 608         dst_port = tb_port_at(xd->route, sw);
 609         nhi_port = tb_switch_find_port(tb->root_switch, TB_TYPE_NHI);
 610
 611         mutex_lock(&tb->lock);
 612         tunnel = tb_tunnel_alloc_dma(tb, nhi_port, dst_port, xd->transmit_ring,
 613                                      xd->transmit_path, xd->receive_ring,
 614                                      xd->receive_path);
 615         if (!tunnel) {
 616                 mutex_unlock(&tb->lock);
 617                 return -ENOMEM;
 618         }
 619
 620         if (tb_tunnel_activate(tunnel)) {
 621                 tb_port_info(nhi_port,
 622                              "DMA tunnel activation failed, aborting\n");
 623                 tb_tunnel_free(tunnel);
 624                 mutex_unlock(&tb->lock);
 625                 return -EIO;
 626         }
 627
 628         list_add_tail(&tunnel->list, &tcm->tunnel_list);
 629         mutex_unlock(&tb->lock);
 630         return 0;
 631 }
 632
 633 static void __tb_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
 634 {
 635         struct tb_port *dst_port;
 636         struct tb_tunnel *tunnel;
 637         struct tb_switch *sw;
 638
 639         sw = tb_to_switch(xd->dev.parent);
 640         dst_port = tb_port_at(xd->route, sw);
 641
 642         /*
 643          * It is possible that the tunnel was already teared down (in
 644          * case of cable disconnect) so it is fine if we cannot find it
 645          * here anymore.
 646          */
 647         tunnel = tb_find_tunnel(tb, TB_TUNNEL_DMA, NULL, dst_port);
 648         tb_deactivate_and_free_tunnel(tunnel);
 649 }
 650
 651 static int tb_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
 652 {
 653         if (!xd->is_unplugged) {
 654                 mutex_lock(&tb->lock);
 655                 __tb_disconnect_xdomain_paths(tb, xd);
 656                 mutex_unlock(&tb->lock);
 657         }
 658         return 0;
 659 }
 660
 661 /* hotplug handling */
 662
 663 /**
 664  * tb_handle_hotplug() - handle hotplug event
 665  *
 666  * Executes on tb->wq.
 667  */
 668 static void tb_handle_hotplug(struct work_struct *work)
 669 {
 670         struct tb_hotplug_event *ev = container_of(work, typeof(*ev), work);
 671         struct tb *tb = ev->tb;
 672         struct tb_cm *tcm = tb_priv(tb);
 673         struct tb_switch *sw;
 674         struct tb_port *port;
 675         mutex_lock(&tb->lock);
 676         if (!tcm->hotplug_active)
 677                 goto out; /* during init, suspend or shutdown */
 678
 679         sw = tb_switch_find_by_route(tb, ev->route);
 680         if (!sw) {
 681                 tb_warn(tb,
 682                         "hotplug event from non existent switch %llx:%x (unplug: %d)\n",
 683                         ev->route, ev->port, ev->unplug);
 684                 goto out;
 685         }
 686         if (ev->port > sw->config.max_port_number) {
 687                 tb_warn(tb,
 688                         "hotplug event from non existent port %llx:%x (unplug: %d)\n",
 689                         ev->route, ev->port, ev->unplug);
 690                 goto put_sw;
 691         }
 692         port = &sw->ports[ev->port];
 693         if (tb_is_upstream_port(port)) {
 694                 tb_dbg(tb, "hotplug event for upstream port %llx:%x (unplug: %d)\n",
 695                        ev->route, ev->port, ev->unplug);
 696                 goto put_sw;
 697         }
 698         if (ev->unplug) {
 699                 if (tb_port_has_remote(port)) {
 700                         tb_port_dbg(port, "switch unplugged\n");
 701                         tb_sw_set_unplugged(port->remote->sw);
 702                         tb_free_invalid_tunnels(tb);
 703                         tb_remove_dp_resources(port->remote->sw);
 704                         tb_switch_lane_bonding_disable(port->remote->sw);
 705                         tb_switch_remove(port->remote->sw);
 706                         port->remote = NULL;
 707                         if (port->dual_link_port)
 708                                 port->dual_link_port->remote = NULL;
 709                         /* Maybe we can create another DP tunnel */
 710                         tb_tunnel_dp(tb);
 711                 } else if (port->xdomain) {
 712                         struct tb_xdomain *xd = tb_xdomain_get(port->xdomain);
 713
 714                         tb_port_dbg(port, "xdomain unplugged\n");
 715                         /*
 716                          * Service drivers are unbound during
 717                          * tb_xdomain_remove() so setting XDomain as
 718                          * unplugged here prevents deadlock if they call
 719                          * tb_xdomain_disable_paths(). We will tear down
 720                          * the path below.
 721                          */
 722                         xd->is_unplugged = true;
 723                         tb_xdomain_remove(xd);
 724                         port->xdomain = NULL;
 725                         __tb_disconnect_xdomain_paths(tb, xd);
 726                         tb_xdomain_put(xd);
 727                 } else if (tb_port_is_dpout(port) || tb_port_is_dpin(port)) {
 728                         tb_dp_resource_unavailable(tb, port);
 729                 } else {
 730                         tb_port_dbg(port,
 731                                    "got unplug event for disconnected port, ignoring\n");
 732                 }
 733         } else if (port->remote) {
 734                 tb_port_dbg(port, "got plug event for connected port, ignoring\n");
 735         } else {
 736                 if (tb_port_is_null(port)) {
 737                         tb_port_dbg(port, "hotplug: scanning\n");
 738                         tb_scan_port(port);
 739                         if (!port->remote)
 740                                 tb_port_dbg(port, "hotplug: no switch found\n");
 741                 } else if (tb_port_is_dpout(port) || tb_port_is_dpin(port)) {
 742                         tb_dp_resource_available(tb, port);
 743                 }
 744         }
 745
 746 put_sw:
 747         tb_switch_put(sw);
 748 out:
 749         mutex_unlock(&tb->lock);
 750         kfree(ev);
 751 }
 752
 753 /**
 754  * tb_schedule_hotplug_handler() - callback function for the control channel
 755  *
 756  * Delegates to tb_handle_hotplug.
 757  */
 758 static void tb_handle_event(struct tb *tb, enum tb_cfg_pkg_type type,
 759                             const void *buf, size_t size)
 760 {
 761         const struct cfg_event_pkg *pkg = buf;
 762         u64 route;
 763
 764         if (type != TB_CFG_PKG_EVENT) {
 765                 tb_warn(tb, "unexpected event %#x, ignoring\n", type);
 766                 return;
 767         }
 768
 769         route = tb_cfg_get_route(&pkg->header);
 770
 771         if (tb_cfg_ack_plug(tb->ctl, route, pkg->port, pkg->unplug)) {
 772                 tb_warn(tb, "could not ack plug event on %llx:%x\n", route,
 773                         pkg->port);
 774         }
 775
 776         tb_queue_hotplug(tb, route, pkg->port, pkg->unplug);
 777 }
 778
 779 static void tb_stop(struct tb *tb)
 780 {
 781         struct tb_cm *tcm = tb_priv(tb);
 782         struct tb_tunnel *tunnel;
 783         struct tb_tunnel *n;
 784
 785         /* tunnels are only present after everything has been initialized */
 786         list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
 787                 /*
 788                  * DMA tunnels require the driver to be functional so we
 789                  * tear them down. Other protocol tunnels can be left
 790                  * intact.
 791                  */
 792                 if (tb_tunnel_is_dma(tunnel))
 793                         tb_tunnel_deactivate(tunnel);
 794                 tb_tunnel_free(tunnel);
 795         }
 796         tb_switch_remove(tb->root_switch);
 797         tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
 798 }
 799
 800 static int tb_scan_finalize_switch(struct device *dev, void *data)
 801 {
 802         if (tb_is_switch(dev)) {
 803                 struct tb_switch *sw = tb_to_switch(dev);
 804
 805                 /*
 806                  * If we found that the switch was already setup by the
 807                  * boot firmware, mark it as authorized now before we
 808                  * send uevent to userspace.
 809                  */
 810                 if (sw->boot)
 811                         sw->authorized = 1;
 812
 813                 dev_set_uevent_suppress(dev, false);
 814                 kobject_uevent(&dev->kobj, KOBJ_ADD);
 815                 device_for_each_child(dev, NULL, tb_scan_finalize_switch);
 816         }
 817
 818         return 0;
 819 }
 820
 821 static int tb_start(struct tb *tb)
 822 {
 823         struct tb_cm *tcm = tb_priv(tb);
 824         int ret;
 825
 826         tb->root_switch = tb_switch_alloc(tb, &tb->dev, 0);
 827         if (IS_ERR(tb->root_switch))
 828                 return PTR_ERR(tb->root_switch);
 829
 830         /*
 831          * ICM firmware upgrade needs running firmware and in native
 832          * mode that is not available so disable firmware upgrade of the
 833          * root switch.
 834          */
 835         tb->root_switch->no_nvm_upgrade = true;
 836
 837         ret = tb_switch_configure(tb->root_switch);
 838         if (ret) {
 839                 tb_switch_put(tb->root_switch);
 840                 return ret;
 841         }
 842
 843         /* Announce the switch to the world */
 844         ret = tb_switch_add(tb->root_switch);
 845         if (ret) {
 846                 tb_switch_put(tb->root_switch);
 847                 return ret;
 848         }
 849
 850         /* Full scan to discover devices added before the driver was loaded. */
 851         tb_scan_switch(tb->root_switch);
 852         /* Find out tunnels created by the boot firmware */
 853         tb_discover_tunnels(tb->root_switch);
 854         /* Add DP IN resources for the root switch */
 855         tb_add_dp_resources(tb->root_switch);
 856         /* Make the discovered switches available to the userspace */
 857         device_for_each_child(&tb->root_switch->dev, NULL,
 858                               tb_scan_finalize_switch);
 859
 860         /* Allow tb_handle_hotplug to progress events */
 861         tcm->hotplug_active = true;
 862         return 0;
 863 }
 864
 865 static int tb_suspend_noirq(struct tb *tb)
 866 {
 867         struct tb_cm *tcm = tb_priv(tb);
 868
 869         tb_dbg(tb, "suspending...\n");
 870         tb_switch_suspend(tb->root_switch);
 871         tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
 872         tb_dbg(tb, "suspend finished\n");
 873
 874         return 0;
 875 }
 876
 877 static void tb_restore_children(struct tb_switch *sw)
 878 {
 879         struct tb_port *port;
 880
 881         tb_switch_for_each_port(sw, port) {
 882                 if (!tb_port_has_remote(port))
 883                         continue;
 884
 885                 if (tb_switch_lane_bonding_enable(port->remote->sw))
 886                         dev_warn(&sw->dev, "failed to restore lane bonding\n");
 887
 888                 tb_restore_children(port->remote->sw);
 889         }
 890 }
 891
 892 static int tb_resume_noirq(struct tb *tb)
 893 {
 894         struct tb_cm *tcm = tb_priv(tb);
 895         struct tb_tunnel *tunnel, *n;
 896
 897         tb_dbg(tb, "resuming...\n");
 898
 899         /* remove any pci devices the firmware might have setup */
 900         tb_switch_reset(tb, 0);
 901
 902         tb_switch_resume(tb->root_switch);
 903         tb_free_invalid_tunnels(tb);
 904         tb_free_unplugged_children(tb->root_switch);
 905         tb_restore_children(tb->root_switch);
 906         list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list)
 907                 tb_tunnel_restart(tunnel);
 908         if (!list_empty(&tcm->tunnel_list)) {
 909                 /*
 910                  * the pcie links need some time to get going.
 911                  * 100ms works for me...
 912                  */
 913                 tb_dbg(tb, "tunnels restarted, sleeping for 100ms\n");
 914                 msleep(100);
 915         }
 916          /* Allow tb_handle_hotplug to progress events */
 917         tcm->hotplug_active = true;
 918         tb_dbg(tb, "resume finished\n");
 919
 920         return 0;
 921 }
 922
 923 static int tb_free_unplugged_xdomains(struct tb_switch *sw)
 924 {
 925         struct tb_port *port;
 926         int ret = 0;
 927
 928         tb_switch_for_each_port(sw, port) {
 929                 if (tb_is_upstream_port(port))
 930                         continue;
 931                 if (port->xdomain && port->xdomain->is_unplugged) {
 932                         tb_xdomain_remove(port->xdomain);
 933                         port->xdomain = NULL;
 934                         ret++;
 935                 } else if (port->remote) {
 936                         ret += tb_free_unplugged_xdomains(port->remote->sw);
 937                 }
 938         }
 939
 940         return ret;
 941 }
 942
 943 static void tb_complete(struct tb *tb)
 944 {
 945         /*
 946          * Release any unplugged XDomains and if there is a case where
 947          * another domain is swapped in place of unplugged XDomain we
 948          * need to run another rescan.
 949          */
 950         mutex_lock(&tb->lock);
 951         if (tb_free_unplugged_xdomains(tb->root_switch))
 952                 tb_scan_switch(tb->root_switch);
 953         mutex_unlock(&tb->lock);
 954 }
 955
 956 static const struct tb_cm_ops tb_cm_ops = {
 957         .start = tb_start,
 958         .stop = tb_stop,
 959         .suspend_noirq = tb_suspend_noirq,
 960         .resume_noirq = tb_resume_noirq,
 961         .complete = tb_complete,
 962         .handle_event = tb_handle_event,
 963         .approve_switch = tb_tunnel_pci,
 964         .approve_xdomain_paths = tb_approve_xdomain_paths,
 965         .disconnect_xdomain_paths = tb_disconnect_xdomain_paths,
 966 };
 967
 968 struct tb *tb_probe(struct tb_nhi *nhi)
 969 {
 970         struct tb_cm *tcm;
 971         struct tb *tb;
 972
 973         tb = tb_domain_alloc(nhi, sizeof(*tcm));
 974         if (!tb)
 975                 return NULL;
 976
 977         tb->security_level = TB_SECURITY_USER;
 978         tb->cm_ops = &tb_cm_ops;
 979
 980         tcm = tb_priv(tb);
 981         INIT_LIST_HEAD(&tcm->tunnel_list);
 982         INIT_LIST_HEAD(&tcm->dp_resources);
 983
 984         return tb;
 985 }