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                 case TB_TYPE_USB3_DOWN:
 115                         tunnel = tb_tunnel_discover_usb3(tb, port);
 116                         break;
 117
 118                 default:
 119                         break;
 120                 }
 121
 122                 if (!tunnel)
 123                         continue;
 124
 125                 if (tb_tunnel_is_pci(tunnel)) {
 126                         struct tb_switch *parent = tunnel->dst_port->sw;
 127
 128                         while (parent != tunnel->src_port->sw) {
 129                                 parent->boot = true;
 130                                 parent = tb_switch_parent(parent);
 131                         }
 132                 }
 133
 134                 list_add_tail(&tunnel->list, &tcm->tunnel_list);
 135         }
 136
 137         tb_switch_for_each_port(sw, port) {
 138                 if (tb_port_has_remote(port))
 139                         tb_discover_tunnels(port->remote->sw);
 140         }
 141 }
 142
 143 static void tb_scan_xdomain(struct tb_port *port)
 144 {
 145         struct tb_switch *sw = port->sw;
 146         struct tb *tb = sw->tb;
 147         struct tb_xdomain *xd;
 148         u64 route;
 149
 150         route = tb_downstream_route(port);
 151         xd = tb_xdomain_find_by_route(tb, route);
 152         if (xd) {
 153                 tb_xdomain_put(xd);
 154                 return;
 155         }
 156
 157         xd = tb_xdomain_alloc(tb, &sw->dev, route, tb->root_switch->uuid,
 158                               NULL);
 159         if (xd) {
 160                 tb_port_at(route, sw)->xdomain = xd;
 161                 tb_xdomain_add(xd);
 162         }
 163 }
 164
 165 static int tb_enable_tmu(struct tb_switch *sw)
 166 {
 167         int ret;
 168
 169         /* If it is already enabled in correct mode, don't touch it */
 170         if (tb_switch_tmu_is_enabled(sw))
 171                 return 0;
 172
 173         ret = tb_switch_tmu_disable(sw);
 174         if (ret)
 175                 return ret;
 176
 177         ret = tb_switch_tmu_post_time(sw);
 178         if (ret)
 179                 return ret;
 180
 181         return tb_switch_tmu_enable(sw);
 182 }
 183
 184 /**
 185  * tb_find_unused_port() - return the first inactive port on @sw
 186  * @sw: Switch to find the port on
 187  * @type: Port type to look for
 188  */
 189 static struct tb_port *tb_find_unused_port(struct tb_switch *sw,
 190                                            enum tb_port_type type)
 191 {
 192         struct tb_port *port;
 193
 194         tb_switch_for_each_port(sw, port) {
 195                 if (tb_is_upstream_port(port))
 196                         continue;
 197                 if (port->config.type != type)
 198                         continue;
 199                 if (!port->cap_adap)
 200                         continue;
 201                 if (tb_port_is_enabled(port))
 202                         continue;
 203                 return port;
 204         }
 205         return NULL;
 206 }
 207
 208 static struct tb_port *tb_find_usb3_down(struct tb_switch *sw,
 209                                         const struct tb_port *port)
 210 {
 211         struct tb_port *down;
 212
 213         down = usb4_switch_map_usb3_down(sw, port);
 214         if (down) {
 215                 if (WARN_ON(!tb_port_is_usb3_down(down)))
 216                         goto out;
 217                 if (WARN_ON(tb_usb3_port_is_enabled(down)))
 218                         goto out;
 219
 220                 return down;
 221         }
 222
 223 out:
 224         return tb_find_unused_port(sw, TB_TYPE_USB3_DOWN);
 225 }
 226
 227 static int tb_tunnel_usb3(struct tb *tb, struct tb_switch *sw)
 228 {
 229         struct tb_switch *parent = tb_switch_parent(sw);
 230         struct tb_port *up, *down, *port;
 231         struct tb_cm *tcm = tb_priv(tb);
 232         struct tb_tunnel *tunnel;
 233
 234         up = tb_switch_find_port(sw, TB_TYPE_USB3_UP);
 235         if (!up)
 236                 return 0;
 237
 238         /*
 239          * Look up available down port. Since we are chaining it should
 240          * be found right above this switch.
 241          */
 242         port = tb_port_at(tb_route(sw), parent);
 243         down = tb_find_usb3_down(parent, port);
 244         if (!down)
 245                 return 0;
 246
 247         if (tb_route(parent)) {
 248                 struct tb_port *parent_up;
 249                 /*
 250                  * Check first that the parent switch has its upstream USB3
 251                  * port enabled. Otherwise the chain is not complete and
 252                  * there is no point setting up a new tunnel.
 253                  */
 254                 parent_up = tb_switch_find_port(parent, TB_TYPE_USB3_UP);
 255                 if (!parent_up || !tb_port_is_enabled(parent_up))
 256                         return 0;
 257         }
 258
 259         tunnel = tb_tunnel_alloc_usb3(tb, up, down);
 260         if (!tunnel)
 261                 return -ENOMEM;
 262
 263         if (tb_tunnel_activate(tunnel)) {
 264                 tb_port_info(up,
 265                              "USB3 tunnel activation failed, aborting\n");
 266                 tb_tunnel_free(tunnel);
 267                 return -EIO;
 268         }
 269
 270         list_add_tail(&tunnel->list, &tcm->tunnel_list);
 271         return 0;
 272 }
 273
 274 static int tb_create_usb3_tunnels(struct tb_switch *sw)
 275 {
 276         struct tb_port *port;
 277         int ret;
 278
 279         if (tb_route(sw)) {
 280                 ret = tb_tunnel_usb3(sw->tb, sw);
 281                 if (ret)
 282                         return ret;
 283         }
 284
 285         tb_switch_for_each_port(sw, port) {
 286                 if (!tb_port_has_remote(port))
 287                         continue;
 288                 ret = tb_create_usb3_tunnels(port->remote->sw);
 289                 if (ret)
 290                         return ret;
 291         }
 292
 293         return 0;
 294 }
 295
 296 static void tb_scan_port(struct tb_port *port);
 297
 298 /**
 299  * tb_scan_switch() - scan for and initialize downstream switches
 300  */
 301 static void tb_scan_switch(struct tb_switch *sw)
 302 {
 303         struct tb_port *port;
 304
 305         tb_switch_for_each_port(sw, port)
 306                 tb_scan_port(port);
 307 }
 308
 309 /**
 310  * tb_scan_port() - check for and initialize switches below port
 311  */
 312 static void tb_scan_port(struct tb_port *port)
 313 {
 314         struct tb_cm *tcm = tb_priv(port->sw->tb);
 315         struct tb_port *upstream_port;
 316         struct tb_switch *sw;
 317
 318         if (tb_is_upstream_port(port))
 319                 return;
 320
 321         if (tb_port_is_dpout(port) && tb_dp_port_hpd_is_active(port) == 1 &&
 322             !tb_dp_port_is_enabled(port)) {
 323                 tb_port_dbg(port, "DP adapter HPD set, queuing hotplug\n");
 324                 tb_queue_hotplug(port->sw->tb, tb_route(port->sw), port->port,
 325                                  false);
 326                 return;
 327         }
 328
 329         if (port->config.type != TB_TYPE_PORT)
 330                 return;
 331         if (port->dual_link_port && port->link_nr)
 332                 return; /*
 333                          * Downstream switch is reachable through two ports.
 334                          * Only scan on the primary port (link_nr == 0).
 335                          */
 336         if (tb_wait_for_port(port, false) <= 0)
 337                 return;
 338         if (port->remote) {
 339                 tb_port_dbg(port, "port already has a remote\n");
 340                 return;
 341         }
 342         sw = tb_switch_alloc(port->sw->tb, &port->sw->dev,
 343                              tb_downstream_route(port));
 344         if (IS_ERR(sw)) {
 345                 /*
 346                  * If there is an error accessing the connected switch
 347                  * it may be connected to another domain. Also we allow
 348                  * the other domain to be connected to a max depth switch.
 349                  */
 350                 if (PTR_ERR(sw) == -EIO || PTR_ERR(sw) == -EADDRNOTAVAIL)
 351                         tb_scan_xdomain(port);
 352                 return;
 353         }
 354
 355         if (tb_switch_configure(sw)) {
 356                 tb_switch_put(sw);
 357                 return;
 358         }
 359
 360         /*
 361          * If there was previously another domain connected remove it
 362          * first.
 363          */
 364         if (port->xdomain) {
 365                 tb_xdomain_remove(port->xdomain);
 366                 port->xdomain = NULL;
 367         }
 368
 369         /*
 370          * Do not send uevents until we have discovered all existing
 371          * tunnels and know which switches were authorized already by
 372          * the boot firmware.
 373          */
 374         if (!tcm->hotplug_active)
 375                 dev_set_uevent_suppress(&sw->dev, true);
 376
 377         if (tb_switch_add(sw)) {
 378                 tb_switch_put(sw);
 379                 return;
 380         }
 381
 382         /* Link the switches using both links if available */
 383         upstream_port = tb_upstream_port(sw);
 384         port->remote = upstream_port;
 385         upstream_port->remote = port;
 386         if (port->dual_link_port && upstream_port->dual_link_port) {
 387                 port->dual_link_port->remote = upstream_port->dual_link_port;
 388                 upstream_port->dual_link_port->remote = port->dual_link_port;
 389         }
 390
 391         /* Enable lane bonding if supported */
 392         if (tb_switch_lane_bonding_enable(sw))
 393                 tb_sw_warn(sw, "failed to enable lane bonding\n");
 394
 395         if (tb_enable_tmu(sw))
 396                 tb_sw_warn(sw, "failed to enable TMU\n");
 397
 398         /*
 399          * Create USB 3.x tunnels only when the switch is plugged to the
 400          * domain. This is because we scan the domain also during discovery
 401          * and want to discover existing USB 3.x tunnels before we create
 402          * any new.
 403          */
 404         if (tcm->hotplug_active && tb_tunnel_usb3(sw->tb, sw))
 405                 tb_sw_warn(sw, "USB3 tunnel creation failed\n");
 406
 407         tb_scan_switch(sw);
 408 }
 409
 410 static struct tb_tunnel *tb_find_tunnel(struct tb *tb, enum tb_tunnel_type type,
 411                                         struct tb_port *src_port,
 412                                         struct tb_port *dst_port)
 413 {
 414         struct tb_cm *tcm = tb_priv(tb);
 415         struct tb_tunnel *tunnel;
 416
 417         list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
 418                 if (tunnel->type == type &&
 419                     ((src_port && src_port == tunnel->src_port) ||
 420                      (dst_port && dst_port == tunnel->dst_port))) {
 421                         return tunnel;
 422                 }
 423         }
 424
 425         return NULL;
 426 }
 427
 428 static void tb_deactivate_and_free_tunnel(struct tb_tunnel *tunnel)
 429 {
 430         if (!tunnel)
 431                 return;
 432
 433         tb_tunnel_deactivate(tunnel);
 434         list_del(&tunnel->list);
 435
 436         /*
 437          * In case of DP tunnel make sure the DP IN resource is deallocated
 438          * properly.
 439          */
 440         if (tb_tunnel_is_dp(tunnel)) {
 441                 struct tb_port *in = tunnel->src_port;
 442
 443                 tb_switch_dealloc_dp_resource(in->sw, in);
 444         }
 445
 446         tb_tunnel_free(tunnel);
 447 }
 448
 449 /**
 450  * tb_free_invalid_tunnels() - destroy tunnels of devices that have gone away
 451  */
 452 static void tb_free_invalid_tunnels(struct tb *tb)
 453 {
 454         struct tb_cm *tcm = tb_priv(tb);
 455         struct tb_tunnel *tunnel;
 456         struct tb_tunnel *n;
 457
 458         list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
 459                 if (tb_tunnel_is_invalid(tunnel))
 460                         tb_deactivate_and_free_tunnel(tunnel);
 461         }
 462 }
 463
 464 /**
 465  * tb_free_unplugged_children() - traverse hierarchy and free unplugged switches
 466  */
 467 static void tb_free_unplugged_children(struct tb_switch *sw)
 468 {
 469         struct tb_port *port;
 470
 471         tb_switch_for_each_port(sw, port) {
 472                 if (!tb_port_has_remote(port))
 473                         continue;
 474
 475                 if (port->remote->sw->is_unplugged) {
 476                         tb_remove_dp_resources(port->remote->sw);
 477                         tb_switch_lane_bonding_disable(port->remote->sw);
 478                         tb_switch_remove(port->remote->sw);
 479                         port->remote = NULL;
 480                         if (port->dual_link_port)
 481                                 port->dual_link_port->remote = NULL;
 482                 } else {
 483                         tb_free_unplugged_children(port->remote->sw);
 484                 }
 485         }
 486 }
 487
 488 static struct tb_port *tb_find_pcie_down(struct tb_switch *sw,
 489                                          const struct tb_port *port)
 490 {
 491         struct tb_port *down = NULL;
 492
 493         /*
 494          * To keep plugging devices consistently in the same PCIe
 495          * hierarchy, do mapping here for switch downstream PCIe ports.
 496          */
 497         if (tb_switch_is_usb4(sw)) {
 498                 down = usb4_switch_map_pcie_down(sw, port);
 499         } else if (!tb_route(sw)) {
 500                 int phy_port = tb_phy_port_from_link(port->port);
 501                 int index;
 502
 503                 /*
 504                  * Hard-coded Thunderbolt port to PCIe down port mapping
 505                  * per controller.
 506                  */
 507                 if (tb_switch_is_cactus_ridge(sw) ||
 508                     tb_switch_is_alpine_ridge(sw))
 509                         index = !phy_port ? 6 : 7;
 510                 else if (tb_switch_is_falcon_ridge(sw))
 511                         index = !phy_port ? 6 : 8;
 512                 else if (tb_switch_is_titan_ridge(sw))
 513                         index = !phy_port ? 8 : 9;
 514                 else
 515                         goto out;
 516
 517                 /* Validate the hard-coding */
 518                 if (WARN_ON(index > sw->config.max_port_number))
 519                         goto out;
 520
 521                 down = &sw->ports[index];
 522         }
 523
 524         if (down) {
 525                 if (WARN_ON(!tb_port_is_pcie_down(down)))
 526                         goto out;
 527                 if (WARN_ON(tb_pci_port_is_enabled(down)))
 528                         goto out;
 529
 530                 return down;
 531         }
 532
 533 out:
 534         return tb_find_unused_port(sw, TB_TYPE_PCIE_DOWN);
 535 }
 536
 537 static int tb_available_bw(struct tb_cm *tcm, struct tb_port *in,
 538                            struct tb_port *out)
 539 {
 540         struct tb_switch *sw = out->sw;
 541         struct tb_tunnel *tunnel;
 542         int bw, available_bw = 40000;
 543
 544         while (sw && sw != in->sw) {
 545                 bw = sw->link_speed * sw->link_width * 1000; /* Mb/s */
 546                 /* Leave 10% guard band */
 547                 bw -= bw / 10;
 548
 549                 /*
 550                  * Check for any active DP tunnels that go through this
 551                  * switch and reduce their consumed bandwidth from
 552                  * available.
 553                  */
 554                 list_for_each_entry(tunnel, &tcm->tunnel_list, list) {
 555                         int consumed_bw;
 556
 557                         if (!tb_tunnel_switch_on_path(tunnel, sw))
 558                                 continue;
 559
 560                         consumed_bw = tb_tunnel_consumed_bandwidth(tunnel);
 561                         if (consumed_bw < 0)
 562                                 return consumed_bw;
 563
 564                         bw -= consumed_bw;
 565                 }
 566
 567                 if (bw < available_bw)
 568                         available_bw = bw;
 569
 570                 sw = tb_switch_parent(sw);
 571         }
 572
 573         return available_bw;
 574 }
 575
 576 static void tb_tunnel_dp(struct tb *tb)
 577 {
 578         struct tb_cm *tcm = tb_priv(tb);
 579         struct tb_port *port, *in, *out;
 580         struct tb_tunnel *tunnel;
 581         int available_bw;
 582
 583         /*
 584          * Find pair of inactive DP IN and DP OUT adapters and then
 585          * establish a DP tunnel between them.
 586          */
 587         tb_dbg(tb, "looking for DP IN <-> DP OUT pairs:\n");
 588
 589         in = NULL;
 590         out = NULL;
 591         list_for_each_entry(port, &tcm->dp_resources, list) {
 592                 if (tb_port_is_enabled(port)) {
 593                         tb_port_dbg(port, "in use\n");
 594                         continue;
 595                 }
 596
 597                 tb_port_dbg(port, "available\n");
 598
 599                 if (!in && tb_port_is_dpin(port))
 600                         in = port;
 601                 else if (!out && tb_port_is_dpout(port))
 602                         out = port;
 603         }
 604
 605         if (!in) {
 606                 tb_dbg(tb, "no suitable DP IN adapter available, not tunneling\n");
 607                 return;
 608         }
 609         if (!out) {
 610                 tb_dbg(tb, "no suitable DP OUT adapter available, not tunneling\n");
 611                 return;
 612         }
 613
 614         if (tb_switch_alloc_dp_resource(in->sw, in)) {
 615                 tb_port_dbg(in, "no resource available for DP IN, not tunneling\n");
 616                 return;
 617         }
 618
 619         /* Calculate available bandwidth between in and out */
 620         available_bw = tb_available_bw(tcm, in, out);
 621         if (available_bw < 0) {
 622                 tb_warn(tb, "failed to determine available bandwidth\n");
 623                 return;
 624         }
 625
 626         tb_dbg(tb, "available bandwidth for new DP tunnel %u Mb/s\n",
 627                available_bw);
 628
 629         tunnel = tb_tunnel_alloc_dp(tb, in, out, available_bw);
 630         if (!tunnel) {
 631                 tb_port_dbg(out, "could not allocate DP tunnel\n");
 632                 goto dealloc_dp;
 633         }
 634
 635         if (tb_tunnel_activate(tunnel)) {
 636                 tb_port_info(out, "DP tunnel activation failed, aborting\n");
 637                 tb_tunnel_free(tunnel);
 638                 goto dealloc_dp;
 639         }
 640
 641         list_add_tail(&tunnel->list, &tcm->tunnel_list);
 642         return;
 643
 644 dealloc_dp:
 645         tb_switch_dealloc_dp_resource(in->sw, in);
 646 }
 647
 648 static void tb_dp_resource_unavailable(struct tb *tb, struct tb_port *port)
 649 {
 650         struct tb_port *in, *out;
 651         struct tb_tunnel *tunnel;
 652
 653         if (tb_port_is_dpin(port)) {
 654                 tb_port_dbg(port, "DP IN resource unavailable\n");
 655                 in = port;
 656                 out = NULL;
 657         } else {
 658                 tb_port_dbg(port, "DP OUT resource unavailable\n");
 659                 in = NULL;
 660                 out = port;
 661         }
 662
 663         tunnel = tb_find_tunnel(tb, TB_TUNNEL_DP, in, out);
 664         tb_deactivate_and_free_tunnel(tunnel);
 665         list_del_init(&port->list);
 666
 667         /*
 668          * See if there is another DP OUT port that can be used for
 669          * to create another tunnel.
 670          */
 671         tb_tunnel_dp(tb);
 672 }
 673
 674 static void tb_dp_resource_available(struct tb *tb, struct tb_port *port)
 675 {
 676         struct tb_cm *tcm = tb_priv(tb);
 677         struct tb_port *p;
 678
 679         if (tb_port_is_enabled(port))
 680                 return;
 681
 682         list_for_each_entry(p, &tcm->dp_resources, list) {
 683                 if (p == port)
 684                         return;
 685         }
 686
 687         tb_port_dbg(port, "DP %s resource available\n",
 688                     tb_port_is_dpin(port) ? "IN" : "OUT");
 689         list_add_tail(&port->list, &tcm->dp_resources);
 690
 691         /* Look for suitable DP IN <-> DP OUT pairs now */
 692         tb_tunnel_dp(tb);
 693 }
 694
 695 static int tb_tunnel_pci(struct tb *tb, struct tb_switch *sw)
 696 {
 697         struct tb_port *up, *down, *port;
 698         struct tb_cm *tcm = tb_priv(tb);
 699         struct tb_switch *parent_sw;
 700         struct tb_tunnel *tunnel;
 701
 702         up = tb_switch_find_port(sw, TB_TYPE_PCIE_UP);
 703         if (!up)
 704                 return 0;
 705
 706         /*
 707          * Look up available down port. Since we are chaining it should
 708          * be found right above this switch.
 709          */
 710         parent_sw = tb_to_switch(sw->dev.parent);
 711         port = tb_port_at(tb_route(sw), parent_sw);
 712         down = tb_find_pcie_down(parent_sw, port);
 713         if (!down)
 714                 return 0;
 715
 716         tunnel = tb_tunnel_alloc_pci(tb, up, down);
 717         if (!tunnel)
 718                 return -ENOMEM;
 719
 720         if (tb_tunnel_activate(tunnel)) {
 721                 tb_port_info(up,
 722                              "PCIe tunnel activation failed, aborting\n");
 723                 tb_tunnel_free(tunnel);
 724                 return -EIO;
 725         }
 726
 727         list_add_tail(&tunnel->list, &tcm->tunnel_list);
 728         return 0;
 729 }
 730
 731 static int tb_approve_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
 732 {
 733         struct tb_cm *tcm = tb_priv(tb);
 734         struct tb_port *nhi_port, *dst_port;
 735         struct tb_tunnel *tunnel;
 736         struct tb_switch *sw;
 737
 738         sw = tb_to_switch(xd->dev.parent);
 739         dst_port = tb_port_at(xd->route, sw);
 740         nhi_port = tb_switch_find_port(tb->root_switch, TB_TYPE_NHI);
 741
 742         mutex_lock(&tb->lock);
 743         tunnel = tb_tunnel_alloc_dma(tb, nhi_port, dst_port, xd->transmit_ring,
 744                                      xd->transmit_path, xd->receive_ring,
 745                                      xd->receive_path);
 746         if (!tunnel) {
 747                 mutex_unlock(&tb->lock);
 748                 return -ENOMEM;
 749         }
 750
 751         if (tb_tunnel_activate(tunnel)) {
 752                 tb_port_info(nhi_port,
 753                              "DMA tunnel activation failed, aborting\n");
 754                 tb_tunnel_free(tunnel);
 755                 mutex_unlock(&tb->lock);
 756                 return -EIO;
 757         }
 758
 759         list_add_tail(&tunnel->list, &tcm->tunnel_list);
 760         mutex_unlock(&tb->lock);
 761         return 0;
 762 }
 763
 764 static void __tb_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
 765 {
 766         struct tb_port *dst_port;
 767         struct tb_tunnel *tunnel;
 768         struct tb_switch *sw;
 769
 770         sw = tb_to_switch(xd->dev.parent);
 771         dst_port = tb_port_at(xd->route, sw);
 772
 773         /*
 774          * It is possible that the tunnel was already teared down (in
 775          * case of cable disconnect) so it is fine if we cannot find it
 776          * here anymore.
 777          */
 778         tunnel = tb_find_tunnel(tb, TB_TUNNEL_DMA, NULL, dst_port);
 779         tb_deactivate_and_free_tunnel(tunnel);
 780 }
 781
 782 static int tb_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd)
 783 {
 784         if (!xd->is_unplugged) {
 785                 mutex_lock(&tb->lock);
 786                 __tb_disconnect_xdomain_paths(tb, xd);
 787                 mutex_unlock(&tb->lock);
 788         }
 789         return 0;
 790 }
 791
 792 /* hotplug handling */
 793
 794 /**
 795  * tb_handle_hotplug() - handle hotplug event
 796  *
 797  * Executes on tb->wq.
 798  */
 799 static void tb_handle_hotplug(struct work_struct *work)
 800 {
 801         struct tb_hotplug_event *ev = container_of(work, typeof(*ev), work);
 802         struct tb *tb = ev->tb;
 803         struct tb_cm *tcm = tb_priv(tb);
 804         struct tb_switch *sw;
 805         struct tb_port *port;
 806         mutex_lock(&tb->lock);
 807         if (!tcm->hotplug_active)
 808                 goto out; /* during init, suspend or shutdown */
 809
 810         sw = tb_switch_find_by_route(tb, ev->route);
 811         if (!sw) {
 812                 tb_warn(tb,
 813                         "hotplug event from non existent switch %llx:%x (unplug: %d)\n",
 814                         ev->route, ev->port, ev->unplug);
 815                 goto out;
 816         }
 817         if (ev->port > sw->config.max_port_number) {
 818                 tb_warn(tb,
 819                         "hotplug event from non existent port %llx:%x (unplug: %d)\n",
 820                         ev->route, ev->port, ev->unplug);
 821                 goto put_sw;
 822         }
 823         port = &sw->ports[ev->port];
 824         if (tb_is_upstream_port(port)) {
 825                 tb_dbg(tb, "hotplug event for upstream port %llx:%x (unplug: %d)\n",
 826                        ev->route, ev->port, ev->unplug);
 827                 goto put_sw;
 828         }
 829         if (ev->unplug) {
 830                 if (tb_port_has_remote(port)) {
 831                         tb_port_dbg(port, "switch unplugged\n");
 832                         tb_sw_set_unplugged(port->remote->sw);
 833                         tb_free_invalid_tunnels(tb);
 834                         tb_remove_dp_resources(port->remote->sw);
 835                         tb_switch_tmu_disable(port->remote->sw);
 836                         tb_switch_lane_bonding_disable(port->remote->sw);
 837                         tb_switch_remove(port->remote->sw);
 838                         port->remote = NULL;
 839                         if (port->dual_link_port)
 840                                 port->dual_link_port->remote = NULL;
 841                         /* Maybe we can create another DP tunnel */
 842                         tb_tunnel_dp(tb);
 843                 } else if (port->xdomain) {
 844                         struct tb_xdomain *xd = tb_xdomain_get(port->xdomain);
 845
 846                         tb_port_dbg(port, "xdomain unplugged\n");
 847                         /*
 848                          * Service drivers are unbound during
 849                          * tb_xdomain_remove() so setting XDomain as
 850                          * unplugged here prevents deadlock if they call
 851                          * tb_xdomain_disable_paths(). We will tear down
 852                          * the path below.
 853                          */
 854                         xd->is_unplugged = true;
 855                         tb_xdomain_remove(xd);
 856                         port->xdomain = NULL;
 857                         __tb_disconnect_xdomain_paths(tb, xd);
 858                         tb_xdomain_put(xd);
 859                 } else if (tb_port_is_dpout(port) || tb_port_is_dpin(port)) {
 860                         tb_dp_resource_unavailable(tb, port);
 861                 } else {
 862                         tb_port_dbg(port,
 863                                    "got unplug event for disconnected port, ignoring\n");
 864                 }
 865         } else if (port->remote) {
 866                 tb_port_dbg(port, "got plug event for connected port, ignoring\n");
 867         } else {
 868                 if (tb_port_is_null(port)) {
 869                         tb_port_dbg(port, "hotplug: scanning\n");
 870                         tb_scan_port(port);
 871                         if (!port->remote)
 872                                 tb_port_dbg(port, "hotplug: no switch found\n");
 873                 } else if (tb_port_is_dpout(port) || tb_port_is_dpin(port)) {
 874                         tb_dp_resource_available(tb, port);
 875                 }
 876         }
 877
 878 put_sw:
 879         tb_switch_put(sw);
 880 out:
 881         mutex_unlock(&tb->lock);
 882         kfree(ev);
 883 }
 884
 885 /**
 886  * tb_schedule_hotplug_handler() - callback function for the control channel
 887  *
 888  * Delegates to tb_handle_hotplug.
 889  */
 890 static void tb_handle_event(struct tb *tb, enum tb_cfg_pkg_type type,
 891                             const void *buf, size_t size)
 892 {
 893         const struct cfg_event_pkg *pkg = buf;
 894         u64 route;
 895
 896         if (type != TB_CFG_PKG_EVENT) {
 897                 tb_warn(tb, "unexpected event %#x, ignoring\n", type);
 898                 return;
 899         }
 900
 901         route = tb_cfg_get_route(&pkg->header);
 902
 903         if (tb_cfg_ack_plug(tb->ctl, route, pkg->port, pkg->unplug)) {
 904                 tb_warn(tb, "could not ack plug event on %llx:%x\n", route,
 905                         pkg->port);
 906         }
 907
 908         tb_queue_hotplug(tb, route, pkg->port, pkg->unplug);
 909 }
 910
 911 static void tb_stop(struct tb *tb)
 912 {
 913         struct tb_cm *tcm = tb_priv(tb);
 914         struct tb_tunnel *tunnel;
 915         struct tb_tunnel *n;
 916
 917         /* tunnels are only present after everything has been initialized */
 918         list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list) {
 919                 /*
 920                  * DMA tunnels require the driver to be functional so we
 921                  * tear them down. Other protocol tunnels can be left
 922                  * intact.
 923                  */
 924                 if (tb_tunnel_is_dma(tunnel))
 925                         tb_tunnel_deactivate(tunnel);
 926                 tb_tunnel_free(tunnel);
 927         }
 928         tb_switch_remove(tb->root_switch);
 929         tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
 930 }
 931
 932 static int tb_scan_finalize_switch(struct device *dev, void *data)
 933 {
 934         if (tb_is_switch(dev)) {
 935                 struct tb_switch *sw = tb_to_switch(dev);
 936
 937                 /*
 938                  * If we found that the switch was already setup by the
 939                  * boot firmware, mark it as authorized now before we
 940                  * send uevent to userspace.
 941                  */
 942                 if (sw->boot)
 943                         sw->authorized = 1;
 944
 945                 dev_set_uevent_suppress(dev, false);
 946                 kobject_uevent(&dev->kobj, KOBJ_ADD);
 947                 device_for_each_child(dev, NULL, tb_scan_finalize_switch);
 948         }
 949
 950         return 0;
 951 }
 952
 953 static int tb_start(struct tb *tb)
 954 {
 955         struct tb_cm *tcm = tb_priv(tb);
 956         int ret;
 957
 958         tb->root_switch = tb_switch_alloc(tb, &tb->dev, 0);
 959         if (IS_ERR(tb->root_switch))
 960                 return PTR_ERR(tb->root_switch);
 961
 962         /*
 963          * ICM firmware upgrade needs running firmware and in native
 964          * mode that is not available so disable firmware upgrade of the
 965          * root switch.
 966          */
 967         tb->root_switch->no_nvm_upgrade = true;
 968
 969         ret = tb_switch_configure(tb->root_switch);
 970         if (ret) {
 971                 tb_switch_put(tb->root_switch);
 972                 return ret;
 973         }
 974
 975         /* Announce the switch to the world */
 976         ret = tb_switch_add(tb->root_switch);
 977         if (ret) {
 978                 tb_switch_put(tb->root_switch);
 979                 return ret;
 980         }
 981
 982         /* Enable TMU if it is off */
 983         tb_switch_tmu_enable(tb->root_switch);
 984         /* Full scan to discover devices added before the driver was loaded. */
 985         tb_scan_switch(tb->root_switch);
 986         /* Find out tunnels created by the boot firmware */
 987         tb_discover_tunnels(tb->root_switch);
 988         /*
 989          * If the boot firmware did not create USB 3.x tunnels create them
 990          * now for the whole topology.
 991          */
 992         tb_create_usb3_tunnels(tb->root_switch);
 993         /* Add DP IN resources for the root switch */
 994         tb_add_dp_resources(tb->root_switch);
 995         /* Make the discovered switches available to the userspace */
 996         device_for_each_child(&tb->root_switch->dev, NULL,
 997                               tb_scan_finalize_switch);
 998
 999         /* Allow tb_handle_hotplug to progress events */
1000         tcm->hotplug_active = true;
1001         return 0;
1002 }
1003
1004 static int tb_suspend_noirq(struct tb *tb)
1005 {
1006         struct tb_cm *tcm = tb_priv(tb);
1007
1008         tb_dbg(tb, "suspending...\n");
1009         tb_switch_suspend(tb->root_switch);
1010         tcm->hotplug_active = false; /* signal tb_handle_hotplug to quit */
1011         tb_dbg(tb, "suspend finished\n");
1012
1013         return 0;
1014 }
1015
1016 static void tb_restore_children(struct tb_switch *sw)
1017 {
1018         struct tb_port *port;
1019
1020         if (tb_enable_tmu(sw))
1021                 tb_sw_warn(sw, "failed to restore TMU configuration\n");
1022
1023         tb_switch_for_each_port(sw, port) {
1024                 if (!tb_port_has_remote(port))
1025                         continue;
1026
1027                 if (tb_switch_lane_bonding_enable(port->remote->sw))
1028                         dev_warn(&sw->dev, "failed to restore lane bonding\n");
1029
1030                 tb_restore_children(port->remote->sw);
1031         }
1032 }
1033
1034 static int tb_resume_noirq(struct tb *tb)
1035 {
1036         struct tb_cm *tcm = tb_priv(tb);
1037         struct tb_tunnel *tunnel, *n;
1038
1039         tb_dbg(tb, "resuming...\n");
1040
1041         /* remove any pci devices the firmware might have setup */
1042         tb_switch_reset(tb, 0);
1043
1044         tb_switch_resume(tb->root_switch);
1045         tb_free_invalid_tunnels(tb);
1046         tb_free_unplugged_children(tb->root_switch);
1047         tb_restore_children(tb->root_switch);
1048         list_for_each_entry_safe(tunnel, n, &tcm->tunnel_list, list)
1049                 tb_tunnel_restart(tunnel);
1050         if (!list_empty(&tcm->tunnel_list)) {
1051                 /*
1052                  * the pcie links need some time to get going.
1053                  * 100ms works for me...
1054                  */
1055                 tb_dbg(tb, "tunnels restarted, sleeping for 100ms\n");
1056                 msleep(100);
1057         }
1058          /* Allow tb_handle_hotplug to progress events */
1059         tcm->hotplug_active = true;
1060         tb_dbg(tb, "resume finished\n");
1061
1062         return 0;
1063 }
1064
1065 static int tb_free_unplugged_xdomains(struct tb_switch *sw)
1066 {
1067         struct tb_port *port;
1068         int ret = 0;
1069
1070         tb_switch_for_each_port(sw, port) {
1071                 if (tb_is_upstream_port(port))
1072                         continue;
1073                 if (port->xdomain && port->xdomain->is_unplugged) {
1074                         tb_xdomain_remove(port->xdomain);
1075                         port->xdomain = NULL;
1076                         ret++;
1077                 } else if (port->remote) {
1078                         ret += tb_free_unplugged_xdomains(port->remote->sw);
1079                 }
1080         }
1081
1082         return ret;
1083 }
1084
1085 static void tb_complete(struct tb *tb)
1086 {
1087         /*
1088          * Release any unplugged XDomains and if there is a case where
1089          * another domain is swapped in place of unplugged XDomain we
1090          * need to run another rescan.
1091          */
1092         mutex_lock(&tb->lock);
1093         if (tb_free_unplugged_xdomains(tb->root_switch))
1094                 tb_scan_switch(tb->root_switch);
1095         mutex_unlock(&tb->lock);
1096 }
1097
1098 static const struct tb_cm_ops tb_cm_ops = {
1099         .start = tb_start,
1100         .stop = tb_stop,
1101         .suspend_noirq = tb_suspend_noirq,
1102         .resume_noirq = tb_resume_noirq,
1103         .complete = tb_complete,
1104         .handle_event = tb_handle_event,
1105         .approve_switch = tb_tunnel_pci,
1106         .approve_xdomain_paths = tb_approve_xdomain_paths,
1107         .disconnect_xdomain_paths = tb_disconnect_xdomain_paths,
1108 };
1109
1110 struct tb *tb_probe(struct tb_nhi *nhi)
1111 {
1112         struct tb_cm *tcm;
1113         struct tb *tb;
1114
1115         tb = tb_domain_alloc(nhi, sizeof(*tcm));
1116         if (!tb)
1117                 return NULL;
1118
1119         tb->security_level = TB_SECURITY_USER;
1120         tb->cm_ops = &tb_cm_ops;
1121
1122         tcm = tb_priv(tb);
1123         INIT_LIST_HEAD(&tcm->tunnel_list);
1124         INIT_LIST_HEAD(&tcm->dp_resources);
1125
1126         return tb;
1127 }