drivers/thunderbolt/tunnel.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Thunderbolt driver - Tunneling support
   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/list.h>
  11
  12 #include "tunnel.h"
  13 #include "tb.h"
  14
  15 /* PCIe adapters use always HopID of 8 for both directions */
  16 #define TB_PCI_HOPID                    8
  17
  18 #define TB_PCI_PATH_DOWN                0
  19 #define TB_PCI_PATH_UP                  1
  20
  21 /* DP adapters use HopID 8 for AUX and 9 for Video */
  22 #define TB_DP_AUX_TX_HOPID              8
  23 #define TB_DP_AUX_RX_HOPID              8
  24 #define TB_DP_VIDEO_HOPID               9
  25
  26 #define TB_DP_VIDEO_PATH_OUT            0
  27 #define TB_DP_AUX_PATH_OUT              1
  28 #define TB_DP_AUX_PATH_IN               2
  29
  30 #define TB_DMA_PATH_OUT                 0
  31 #define TB_DMA_PATH_IN                  1
  32
  33 static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA" };
  34
  35 #define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...)                   \
  36         do {                                                            \
  37                 struct tb_tunnel *__tunnel = (tunnel);                  \
  38                 level(__tunnel->tb, "%llx:%x <-> %llx:%x (%s): " fmt,   \
  39                       tb_route(__tunnel->src_port->sw),                 \
  40                       __tunnel->src_port->port,                         \
  41                       tb_route(__tunnel->dst_port->sw),                 \
  42                       __tunnel->dst_port->port,                         \
  43                       tb_tunnel_names[__tunnel->type],                  \
  44                       ## arg);                                          \
  45         } while (0)
  46
  47 #define tb_tunnel_WARN(tunnel, fmt, arg...) \
  48         __TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
  49 #define tb_tunnel_warn(tunnel, fmt, arg...) \
  50         __TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
  51 #define tb_tunnel_info(tunnel, fmt, arg...) \
  52         __TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
  53 #define tb_tunnel_dbg(tunnel, fmt, arg...) \
  54         __TB_TUNNEL_PRINT(tb_dbg, tunnel, fmt, ##arg)
  55
  56 static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
  57                                          enum tb_tunnel_type type)
  58 {
  59         struct tb_tunnel *tunnel;
  60
  61         tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
  62         if (!tunnel)
  63                 return NULL;
  64
  65         tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL);
  66         if (!tunnel->paths) {
  67                 tb_tunnel_free(tunnel);
  68                 return NULL;
  69         }
  70
  71         INIT_LIST_HEAD(&tunnel->list);
  72         tunnel->tb = tb;
  73         tunnel->npaths = npaths;
  74         tunnel->type = type;
  75
  76         return tunnel;
  77 }
  78
  79 static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)
  80 {
  81         int res;
  82
  83         res = tb_pci_port_enable(tunnel->src_port, activate);
  84         if (res)
  85                 return res;
  86
  87         if (tb_port_is_pcie_up(tunnel->dst_port))
  88                 return tb_pci_port_enable(tunnel->dst_port, activate);
  89
  90         return 0;
  91 }
  92
  93 static int tb_initial_credits(const struct tb_switch *sw)
  94 {
  95         /* If the path is complete sw is not NULL */
  96         if (sw) {
  97                 /* More credits for faster link */
  98                 switch (sw->link_speed * sw->link_width) {
  99                 case 40:
 100                         return 32;
 101                 case 20:
 102                         return 24;
 103                 }
 104         }
 105
 106         return 16;
 107 }
 108
 109 static void tb_pci_init_path(struct tb_path *path)
 110 {
 111         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
 112         path->egress_shared_buffer = TB_PATH_NONE;
 113         path->ingress_fc_enable = TB_PATH_ALL;
 114         path->ingress_shared_buffer = TB_PATH_NONE;
 115         path->priority = 3;
 116         path->weight = 1;
 117         path->drop_packages = 0;
 118         path->nfc_credits = 0;
 119         path->hops[0].initial_credits = 7;
 120         path->hops[1].initial_credits =
 121                 tb_initial_credits(path->hops[1].in_port->sw);
 122 }
 123
 124 /**
 125  * tb_tunnel_discover_pci() - Discover existing PCIe tunnels
 126  * @tb: Pointer to the domain structure
 127  * @down: PCIe downstream adapter
 128  *
 129  * If @down adapter is active, follows the tunnel to the PCIe upstream
 130  * adapter and back. Returns the discovered tunnel or %NULL if there was
 131  * no tunnel.
 132  */
 133 struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down)
 134 {
 135         struct tb_tunnel *tunnel;
 136         struct tb_path *path;
 137
 138         if (!tb_pci_port_is_enabled(down))
 139                 return NULL;
 140
 141         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
 142         if (!tunnel)
 143                 return NULL;
 144
 145         tunnel->activate = tb_pci_activate;
 146         tunnel->src_port = down;
 147
 148         /*
 149          * Discover both paths even if they are not complete. We will
 150          * clean them up by calling tb_tunnel_deactivate() below in that
 151          * case.
 152          */
 153         path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1,
 154                                 &tunnel->dst_port, "PCIe Up");
 155         if (!path) {
 156                 /* Just disable the downstream port */
 157                 tb_pci_port_enable(down, false);
 158                 goto err_free;
 159         }
 160         tunnel->paths[TB_PCI_PATH_UP] = path;
 161         tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]);
 162
 163         path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL,
 164                                 "PCIe Down");
 165         if (!path)
 166                 goto err_deactivate;
 167         tunnel->paths[TB_PCI_PATH_DOWN] = path;
 168         tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]);
 169
 170         /* Validate that the tunnel is complete */
 171         if (!tb_port_is_pcie_up(tunnel->dst_port)) {
 172                 tb_port_warn(tunnel->dst_port,
 173                              "path does not end on a PCIe adapter, cleaning up\n");
 174                 goto err_deactivate;
 175         }
 176
 177         if (down != tunnel->src_port) {
 178                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
 179                 goto err_deactivate;
 180         }
 181
 182         if (!tb_pci_port_is_enabled(tunnel->dst_port)) {
 183                 tb_tunnel_warn(tunnel,
 184                                "tunnel is not fully activated, cleaning up\n");
 185                 goto err_deactivate;
 186         }
 187
 188         tb_tunnel_dbg(tunnel, "discovered\n");
 189         return tunnel;
 190
 191 err_deactivate:
 192         tb_tunnel_deactivate(tunnel);
 193 err_free:
 194         tb_tunnel_free(tunnel);
 195
 196         return NULL;
 197 }
 198
 199 /**
 200  * tb_tunnel_alloc_pci() - allocate a pci tunnel
 201  * @tb: Pointer to the domain structure
 202  * @up: PCIe upstream adapter port
 203  * @down: PCIe downstream adapter port
 204  *
 205  * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
 206  * TB_TYPE_PCIE_DOWN.
 207  *
 208  * Return: Returns a tb_tunnel on success or NULL on failure.
 209  */
 210 struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
 211                                       struct tb_port *down)
 212 {
 213         struct tb_tunnel *tunnel;
 214         struct tb_path *path;
 215
 216         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
 217         if (!tunnel)
 218                 return NULL;
 219
 220         tunnel->activate = tb_pci_activate;
 221         tunnel->src_port = down;
 222         tunnel->dst_port = up;
 223
 224         path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0,
 225                              "PCIe Down");
 226         if (!path) {
 227                 tb_tunnel_free(tunnel);
 228                 return NULL;
 229         }
 230         tb_pci_init_path(path);
 231         tunnel->paths[TB_PCI_PATH_DOWN] = path;
 232
 233         path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0,
 234                              "PCIe Up");
 235         if (!path) {
 236                 tb_tunnel_free(tunnel);
 237                 return NULL;
 238         }
 239         tb_pci_init_path(path);
 240         tunnel->paths[TB_PCI_PATH_UP] = path;
 241
 242         return tunnel;
 243 }
 244
 245 static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
 246 {
 247         struct tb_port *out = tunnel->dst_port;
 248         struct tb_port *in = tunnel->src_port;
 249         u32 in_dp_cap, out_dp_cap;
 250         int ret;
 251
 252         /*
 253          * Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for
 254          * newer generation hardware.
 255          */
 256         if (in->sw->generation < 2 || out->sw->generation < 2)
 257                 return 0;
 258
 259         /* Read both DP_LOCAL_CAP registers */
 260         ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
 261                            in->cap_adap + DP_LOCAL_CAP, 1);
 262         if (ret)
 263                 return ret;
 264
 265         ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
 266                            out->cap_adap + DP_LOCAL_CAP, 1);
 267         if (ret)
 268                 return ret;
 269
 270         /* Write IN local caps to OUT remote caps */
 271         ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT,
 272                             out->cap_adap + DP_REMOTE_CAP, 1);
 273         if (ret)
 274                 return ret;
 275
 276         return tb_port_write(in, &out_dp_cap, TB_CFG_PORT,
 277                              in->cap_adap + DP_REMOTE_CAP, 1);
 278 }
 279
 280 static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
 281 {
 282         int ret;
 283
 284         if (active) {
 285                 struct tb_path **paths;
 286                 int last;
 287
 288                 paths = tunnel->paths;
 289                 last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;
 290
 291                 tb_dp_port_set_hops(tunnel->src_port,
 292                         paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,
 293                         paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,
 294                         paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);
 295
 296                 tb_dp_port_set_hops(tunnel->dst_port,
 297                         paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,
 298                         paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,
 299                         paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);
 300         } else {
 301                 tb_dp_port_hpd_clear(tunnel->src_port);
 302                 tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0);
 303                 if (tb_port_is_dpout(tunnel->dst_port))
 304                         tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0);
 305         }
 306
 307         ret = tb_dp_port_enable(tunnel->src_port, active);
 308         if (ret)
 309                 return ret;
 310
 311         if (tb_port_is_dpout(tunnel->dst_port))
 312                 return tb_dp_port_enable(tunnel->dst_port, active);
 313
 314         return 0;
 315 }
 316
 317 static void tb_dp_init_aux_path(struct tb_path *path)
 318 {
 319         int i;
 320
 321         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
 322         path->egress_shared_buffer = TB_PATH_NONE;
 323         path->ingress_fc_enable = TB_PATH_ALL;
 324         path->ingress_shared_buffer = TB_PATH_NONE;
 325         path->priority = 2;
 326         path->weight = 1;
 327
 328         for (i = 0; i < path->path_length; i++)
 329                 path->hops[i].initial_credits = 1;
 330 }
 331
 332 static void tb_dp_init_video_path(struct tb_path *path, bool discover)
 333 {
 334         u32 nfc_credits = path->hops[0].in_port->config.nfc_credits;
 335
 336         path->egress_fc_enable = TB_PATH_NONE;
 337         path->egress_shared_buffer = TB_PATH_NONE;
 338         path->ingress_fc_enable = TB_PATH_NONE;
 339         path->ingress_shared_buffer = TB_PATH_NONE;
 340         path->priority = 1;
 341         path->weight = 1;
 342
 343         if (discover) {
 344                 path->nfc_credits = nfc_credits & ADP_CS_4_NFC_BUFFERS_MASK;
 345         } else {
 346                 u32 max_credits;
 347
 348                 max_credits = (nfc_credits & ADP_CS_4_TOTAL_BUFFERS_MASK) >>
 349                         ADP_CS_4_TOTAL_BUFFERS_SHIFT;
 350                 /* Leave some credits for AUX path */
 351                 path->nfc_credits = min(max_credits - 2, 12U);
 352         }
 353 }
 354
 355 /**
 356  * tb_tunnel_discover_dp() - Discover existing Display Port tunnels
 357  * @tb: Pointer to the domain structure
 358  * @in: DP in adapter
 359  *
 360  * If @in adapter is active, follows the tunnel to the DP out adapter
 361  * and back. Returns the discovered tunnel or %NULL if there was no
 362  * tunnel.
 363  *
 364  * Return: DP tunnel or %NULL if no tunnel found.
 365  */
 366 struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in)
 367 {
 368         struct tb_tunnel *tunnel;
 369         struct tb_port *port;
 370         struct tb_path *path;
 371
 372         if (!tb_dp_port_is_enabled(in))
 373                 return NULL;
 374
 375         tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
 376         if (!tunnel)
 377                 return NULL;
 378
 379         tunnel->init = tb_dp_xchg_caps;
 380         tunnel->activate = tb_dp_activate;
 381         tunnel->src_port = in;
 382
 383         path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1,
 384                                 &tunnel->dst_port, "Video");
 385         if (!path) {
 386                 /* Just disable the DP IN port */
 387                 tb_dp_port_enable(in, false);
 388                 goto err_free;
 389         }
 390         tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;
 391         tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT], true);
 392
 393         path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX");
 394         if (!path)
 395                 goto err_deactivate;
 396         tunnel->paths[TB_DP_AUX_PATH_OUT] = path;
 397         tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT]);
 398
 399         path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID,
 400                                 &port, "AUX RX");
 401         if (!path)
 402                 goto err_deactivate;
 403         tunnel->paths[TB_DP_AUX_PATH_IN] = path;
 404         tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN]);
 405
 406         /* Validate that the tunnel is complete */
 407         if (!tb_port_is_dpout(tunnel->dst_port)) {
 408                 tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");
 409                 goto err_deactivate;
 410         }
 411
 412         if (!tb_dp_port_is_enabled(tunnel->dst_port))
 413                 goto err_deactivate;
 414
 415         if (!tb_dp_port_hpd_is_active(tunnel->dst_port))
 416                 goto err_deactivate;
 417
 418         if (port != tunnel->src_port) {
 419                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
 420                 goto err_deactivate;
 421         }
 422
 423         tb_tunnel_dbg(tunnel, "discovered\n");
 424         return tunnel;
 425
 426 err_deactivate:
 427         tb_tunnel_deactivate(tunnel);
 428 err_free:
 429         tb_tunnel_free(tunnel);
 430
 431         return NULL;
 432 }
 433
 434 /**
 435  * tb_tunnel_alloc_dp() - allocate a Display Port tunnel
 436  * @tb: Pointer to the domain structure
 437  * @in: DP in adapter port
 438  * @out: DP out adapter port
 439  *
 440  * Allocates a tunnel between @in and @out that is capable of tunneling
 441  * Display Port traffic.
 442  *
 443  * Return: Returns a tb_tunnel on success or NULL on failure.
 444  */
 445 struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
 446                                      struct tb_port *out)
 447 {
 448         struct tb_tunnel *tunnel;
 449         struct tb_path **paths;
 450         struct tb_path *path;
 451
 452         if (WARN_ON(!in->cap_adap || !out->cap_adap))
 453                 return NULL;
 454
 455         tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
 456         if (!tunnel)
 457                 return NULL;
 458
 459         tunnel->init = tb_dp_xchg_caps;
 460         tunnel->activate = tb_dp_activate;
 461         tunnel->src_port = in;
 462         tunnel->dst_port = out;
 463
 464         paths = tunnel->paths;
 465
 466         path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,
 467                              1, "Video");
 468         if (!path)
 469                 goto err_free;
 470         tb_dp_init_video_path(path, false);
 471         paths[TB_DP_VIDEO_PATH_OUT] = path;
 472
 473         path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
 474                              TB_DP_AUX_TX_HOPID, 1, "AUX TX");
 475         if (!path)
 476                 goto err_free;
 477         tb_dp_init_aux_path(path);
 478         paths[TB_DP_AUX_PATH_OUT] = path;
 479
 480         path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,
 481                              TB_DP_AUX_RX_HOPID, 1, "AUX RX");
 482         if (!path)
 483                 goto err_free;
 484         tb_dp_init_aux_path(path);
 485         paths[TB_DP_AUX_PATH_IN] = path;
 486
 487         return tunnel;
 488
 489 err_free:
 490         tb_tunnel_free(tunnel);
 491         return NULL;
 492 }
 493
 494 static u32 tb_dma_credits(struct tb_port *nhi)
 495 {
 496         u32 max_credits;
 497
 498         max_credits = (nhi->config.nfc_credits & ADP_CS_4_TOTAL_BUFFERS_MASK) >>
 499                 ADP_CS_4_TOTAL_BUFFERS_SHIFT;
 500         return min(max_credits, 13U);
 501 }
 502
 503 static int tb_dma_activate(struct tb_tunnel *tunnel, bool active)
 504 {
 505         struct tb_port *nhi = tunnel->src_port;
 506         u32 credits;
 507
 508         credits = active ? tb_dma_credits(nhi) : 0;
 509         return tb_port_set_initial_credits(nhi, credits);
 510 }
 511
 512 static void tb_dma_init_path(struct tb_path *path, unsigned int isb,
 513                              unsigned int efc, u32 credits)
 514 {
 515         int i;
 516
 517         path->egress_fc_enable = efc;
 518         path->ingress_fc_enable = TB_PATH_ALL;
 519         path->egress_shared_buffer = TB_PATH_NONE;
 520         path->ingress_shared_buffer = isb;
 521         path->priority = 5;
 522         path->weight = 1;
 523         path->clear_fc = true;
 524
 525         for (i = 0; i < path->path_length; i++)
 526                 path->hops[i].initial_credits = credits;
 527 }
 528
 529 /**
 530  * tb_tunnel_alloc_dma() - allocate a DMA tunnel
 531  * @tb: Pointer to the domain structure
 532  * @nhi: Host controller port
 533  * @dst: Destination null port which the other domain is connected to
 534  * @transmit_ring: NHI ring number used to send packets towards the
 535  *                 other domain
 536  * @transmit_path: HopID used for transmitting packets
 537  * @receive_ring: NHI ring number used to receive packets from the
 538  *                other domain
 539  * @reveive_path: HopID used for receiving packets
 540  *
 541  * Return: Returns a tb_tunnel on success or NULL on failure.
 542  */
 543 struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
 544                                       struct tb_port *dst, int transmit_ring,
 545                                       int transmit_path, int receive_ring,
 546                                       int receive_path)
 547 {
 548         struct tb_tunnel *tunnel;
 549         struct tb_path *path;
 550         u32 credits;
 551
 552         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_DMA);
 553         if (!tunnel)
 554                 return NULL;
 555
 556         tunnel->activate = tb_dma_activate;
 557         tunnel->src_port = nhi;
 558         tunnel->dst_port = dst;
 559
 560         credits = tb_dma_credits(nhi);
 561
 562         path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0, "DMA RX");
 563         if (!path) {
 564                 tb_tunnel_free(tunnel);
 565                 return NULL;
 566         }
 567         tb_dma_init_path(path, TB_PATH_NONE, TB_PATH_SOURCE | TB_PATH_INTERNAL,
 568                          credits);
 569         tunnel->paths[TB_DMA_PATH_IN] = path;
 570
 571         path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0, "DMA TX");
 572         if (!path) {
 573                 tb_tunnel_free(tunnel);
 574                 return NULL;
 575         }
 576         tb_dma_init_path(path, TB_PATH_SOURCE, TB_PATH_ALL, credits);
 577         tunnel->paths[TB_DMA_PATH_OUT] = path;
 578
 579         return tunnel;
 580 }
 581
 582 /**
 583  * tb_tunnel_free() - free a tunnel
 584  * @tunnel: Tunnel to be freed
 585  *
 586  * Frees a tunnel. The tunnel does not need to be deactivated.
 587  */
 588 void tb_tunnel_free(struct tb_tunnel *tunnel)
 589 {
 590         int i;
 591
 592         if (!tunnel)
 593                 return;
 594
 595         for (i = 0; i < tunnel->npaths; i++) {
 596                 if (tunnel->paths[i])
 597                         tb_path_free(tunnel->paths[i]);
 598         }
 599
 600         kfree(tunnel->paths);
 601         kfree(tunnel);
 602 }
 603
 604 /**
 605  * tb_tunnel_is_invalid - check whether an activated path is still valid
 606  * @tunnel: Tunnel to check
 607  */
 608 bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
 609 {
 610         int i;
 611
 612         for (i = 0; i < tunnel->npaths; i++) {
 613                 WARN_ON(!tunnel->paths[i]->activated);
 614                 if (tb_path_is_invalid(tunnel->paths[i]))
 615                         return true;
 616         }
 617
 618         return false;
 619 }
 620
 621 /**
 622  * tb_tunnel_restart() - activate a tunnel after a hardware reset
 623  * @tunnel: Tunnel to restart
 624  *
 625  * Return: 0 on success and negative errno in case if failure
 626  */
 627 int tb_tunnel_restart(struct tb_tunnel *tunnel)
 628 {
 629         int res, i;
 630
 631         tb_tunnel_dbg(tunnel, "activating\n");
 632
 633         /*
 634          * Make sure all paths are properly disabled before enabling
 635          * them again.
 636          */
 637         for (i = 0; i < tunnel->npaths; i++) {
 638                 if (tunnel->paths[i]->activated) {
 639                         tb_path_deactivate(tunnel->paths[i]);
 640                         tunnel->paths[i]->activated = false;
 641                 }
 642         }
 643
 644         if (tunnel->init) {
 645                 res = tunnel->init(tunnel);
 646                 if (res)
 647                         return res;
 648         }
 649
 650         for (i = 0; i < tunnel->npaths; i++) {
 651                 res = tb_path_activate(tunnel->paths[i]);
 652                 if (res)
 653                         goto err;
 654         }
 655
 656         if (tunnel->activate) {
 657                 res = tunnel->activate(tunnel, true);
 658                 if (res)
 659                         goto err;
 660         }
 661
 662         return 0;
 663
 664 err:
 665         tb_tunnel_warn(tunnel, "activation failed\n");
 666         tb_tunnel_deactivate(tunnel);
 667         return res;
 668 }
 669
 670 /**
 671  * tb_tunnel_activate() - activate a tunnel
 672  * @tunnel: Tunnel to activate
 673  *
 674  * Return: Returns 0 on success or an error code on failure.
 675  */
 676 int tb_tunnel_activate(struct tb_tunnel *tunnel)
 677 {
 678         int i;
 679
 680         for (i = 0; i < tunnel->npaths; i++) {
 681                 if (tunnel->paths[i]->activated) {
 682                         tb_tunnel_WARN(tunnel,
 683                                        "trying to activate an already activated tunnel\n");
 684                         return -EINVAL;
 685                 }
 686         }
 687
 688         return tb_tunnel_restart(tunnel);
 689 }
 690
 691 /**
 692  * tb_tunnel_deactivate() - deactivate a tunnel
 693  * @tunnel: Tunnel to deactivate
 694  */
 695 void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
 696 {
 697         int i;
 698
 699         tb_tunnel_dbg(tunnel, "deactivating\n");
 700
 701         if (tunnel->activate)
 702                 tunnel->activate(tunnel, false);
 703
 704         for (i = 0; i < tunnel->npaths; i++) {
 705                 if (tunnel->paths[i] && tunnel->paths[i]->activated)
 706                         tb_path_deactivate(tunnel->paths[i]);
 707         }
 708 }