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