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/delay.h>
  10 #include <linux/slab.h>
  11 #include <linux/list.h>
  12
  13 #include "tunnel.h"
  14 #include "tb.h"
  15
  16 /* PCIe adapters use always HopID of 8 for both directions */
  17 #define TB_PCI_HOPID                    8
  18
  19 #define TB_PCI_PATH_DOWN                0
  20 #define TB_PCI_PATH_UP                  1
  21
  22 /* USB3 adapters use always HopID of 8 for both directions */
  23 #define TB_USB3_HOPID                   8
  24
  25 #define TB_USB3_PATH_DOWN               0
  26 #define TB_USB3_PATH_UP                 1
  27
  28 /* DP adapters use HopID 8 for AUX and 9 for Video */
  29 #define TB_DP_AUX_TX_HOPID              8
  30 #define TB_DP_AUX_RX_HOPID              8
  31 #define TB_DP_VIDEO_HOPID               9
  32
  33 #define TB_DP_VIDEO_PATH_OUT            0
  34 #define TB_DP_AUX_PATH_OUT              1
  35 #define TB_DP_AUX_PATH_IN               2
  36
  37 static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA", "USB3" };
  38
  39 #define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...)                   \
  40         do {                                                            \
  41                 struct tb_tunnel *__tunnel = (tunnel);                  \
  42                 level(__tunnel->tb, "%llx:%x <-> %llx:%x (%s): " fmt,   \
  43                       tb_route(__tunnel->src_port->sw),                 \
  44                       __tunnel->src_port->port,                         \
  45                       tb_route(__tunnel->dst_port->sw),                 \
  46                       __tunnel->dst_port->port,                         \
  47                       tb_tunnel_names[__tunnel->type],                  \
  48                       ## arg);                                          \
  49         } while (0)
  50
  51 #define tb_tunnel_WARN(tunnel, fmt, arg...) \
  52         __TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
  53 #define tb_tunnel_warn(tunnel, fmt, arg...) \
  54         __TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
  55 #define tb_tunnel_info(tunnel, fmt, arg...) \
  56         __TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
  57 #define tb_tunnel_dbg(tunnel, fmt, arg...) \
  58         __TB_TUNNEL_PRINT(tb_dbg, tunnel, fmt, ##arg)
  59
  60 static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
  61                                          enum tb_tunnel_type type)
  62 {
  63         struct tb_tunnel *tunnel;
  64
  65         tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
  66         if (!tunnel)
  67                 return NULL;
  68
  69         tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL);
  70         if (!tunnel->paths) {
  71                 tb_tunnel_free(tunnel);
  72                 return NULL;
  73         }
  74
  75         INIT_LIST_HEAD(&tunnel->list);
  76         tunnel->tb = tb;
  77         tunnel->npaths = npaths;
  78         tunnel->type = type;
  79
  80         return tunnel;
  81 }
  82
  83 static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)
  84 {
  85         int res;
  86
  87         res = tb_pci_port_enable(tunnel->src_port, activate);
  88         if (res)
  89                 return res;
  90
  91         if (tb_port_is_pcie_up(tunnel->dst_port))
  92                 return tb_pci_port_enable(tunnel->dst_port, activate);
  93
  94         return 0;
  95 }
  96
  97 static int tb_initial_credits(const struct tb_switch *sw)
  98 {
  99         /* If the path is complete sw is not NULL */
 100         if (sw) {
 101                 /* More credits for faster link */
 102                 switch (sw->link_speed * sw->link_width) {
 103                 case 40:
 104                         return 32;
 105                 case 20:
 106                         return 24;
 107                 }
 108         }
 109
 110         return 16;
 111 }
 112
 113 static void tb_pci_init_path(struct tb_path *path)
 114 {
 115         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
 116         path->egress_shared_buffer = TB_PATH_NONE;
 117         path->ingress_fc_enable = TB_PATH_ALL;
 118         path->ingress_shared_buffer = TB_PATH_NONE;
 119         path->priority = 3;
 120         path->weight = 1;
 121         path->drop_packages = 0;
 122         path->nfc_credits = 0;
 123         path->hops[0].initial_credits = 7;
 124         if (path->path_length > 1)
 125                 path->hops[1].initial_credits =
 126                         tb_initial_credits(path->hops[1].in_port->sw);
 127 }
 128
 129 /**
 130  * tb_tunnel_discover_pci() - Discover existing PCIe tunnels
 131  * @tb: Pointer to the domain structure
 132  * @down: PCIe downstream adapter
 133  *
 134  * If @down adapter is active, follows the tunnel to the PCIe upstream
 135  * adapter and back. Returns the discovered tunnel or %NULL if there was
 136  * no tunnel.
 137  */
 138 struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down)
 139 {
 140         struct tb_tunnel *tunnel;
 141         struct tb_path *path;
 142
 143         if (!tb_pci_port_is_enabled(down))
 144                 return NULL;
 145
 146         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
 147         if (!tunnel)
 148                 return NULL;
 149
 150         tunnel->activate = tb_pci_activate;
 151         tunnel->src_port = down;
 152
 153         /*
 154          * Discover both paths even if they are not complete. We will
 155          * clean them up by calling tb_tunnel_deactivate() below in that
 156          * case.
 157          */
 158         path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1,
 159                                 &tunnel->dst_port, "PCIe Up");
 160         if (!path) {
 161                 /* Just disable the downstream port */
 162                 tb_pci_port_enable(down, false);
 163                 goto err_free;
 164         }
 165         tunnel->paths[TB_PCI_PATH_UP] = path;
 166         tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]);
 167
 168         path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL,
 169                                 "PCIe Down");
 170         if (!path)
 171                 goto err_deactivate;
 172         tunnel->paths[TB_PCI_PATH_DOWN] = path;
 173         tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]);
 174
 175         /* Validate that the tunnel is complete */
 176         if (!tb_port_is_pcie_up(tunnel->dst_port)) {
 177                 tb_port_warn(tunnel->dst_port,
 178                              "path does not end on a PCIe adapter, cleaning up\n");
 179                 goto err_deactivate;
 180         }
 181
 182         if (down != tunnel->src_port) {
 183                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
 184                 goto err_deactivate;
 185         }
 186
 187         if (!tb_pci_port_is_enabled(tunnel->dst_port)) {
 188                 tb_tunnel_warn(tunnel,
 189                                "tunnel is not fully activated, cleaning up\n");
 190                 goto err_deactivate;
 191         }
 192
 193         tb_tunnel_dbg(tunnel, "discovered\n");
 194         return tunnel;
 195
 196 err_deactivate:
 197         tb_tunnel_deactivate(tunnel);
 198 err_free:
 199         tb_tunnel_free(tunnel);
 200
 201         return NULL;
 202 }
 203
 204 /**
 205  * tb_tunnel_alloc_pci() - allocate a pci tunnel
 206  * @tb: Pointer to the domain structure
 207  * @up: PCIe upstream adapter port
 208  * @down: PCIe downstream adapter port
 209  *
 210  * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
 211  * TB_TYPE_PCIE_DOWN.
 212  *
 213  * Return: Returns a tb_tunnel on success or NULL on failure.
 214  */
 215 struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
 216                                       struct tb_port *down)
 217 {
 218         struct tb_tunnel *tunnel;
 219         struct tb_path *path;
 220
 221         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
 222         if (!tunnel)
 223                 return NULL;
 224
 225         tunnel->activate = tb_pci_activate;
 226         tunnel->src_port = down;
 227         tunnel->dst_port = up;
 228
 229         path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0,
 230                              "PCIe Down");
 231         if (!path) {
 232                 tb_tunnel_free(tunnel);
 233                 return NULL;
 234         }
 235         tb_pci_init_path(path);
 236         tunnel->paths[TB_PCI_PATH_DOWN] = path;
 237
 238         path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0,
 239                              "PCIe Up");
 240         if (!path) {
 241                 tb_tunnel_free(tunnel);
 242                 return NULL;
 243         }
 244         tb_pci_init_path(path);
 245         tunnel->paths[TB_PCI_PATH_UP] = path;
 246
 247         return tunnel;
 248 }
 249
 250 static bool tb_dp_is_usb4(const struct tb_switch *sw)
 251 {
 252         /* Titan Ridge DP adapters need the same treatment as USB4 */
 253         return tb_switch_is_usb4(sw) || tb_switch_is_titan_ridge(sw);
 254 }
 255
 256 static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out)
 257 {
 258         int timeout = 10;
 259         u32 val;
 260         int ret;
 261
 262         /* Both ends need to support this */
 263         if (!tb_dp_is_usb4(in->sw) || !tb_dp_is_usb4(out->sw))
 264                 return 0;
 265
 266         ret = tb_port_read(out, &val, TB_CFG_PORT,
 267                            out->cap_adap + DP_STATUS_CTRL, 1);
 268         if (ret)
 269                 return ret;
 270
 271         val |= DP_STATUS_CTRL_UF | DP_STATUS_CTRL_CMHS;
 272
 273         ret = tb_port_write(out, &val, TB_CFG_PORT,
 274                             out->cap_adap + DP_STATUS_CTRL, 1);
 275         if (ret)
 276                 return ret;
 277
 278         do {
 279                 ret = tb_port_read(out, &val, TB_CFG_PORT,
 280                                    out->cap_adap + DP_STATUS_CTRL, 1);
 281                 if (ret)
 282                         return ret;
 283                 if (!(val & DP_STATUS_CTRL_CMHS))
 284                         return 0;
 285                 usleep_range(10, 100);
 286         } while (timeout--);
 287
 288         return -ETIMEDOUT;
 289 }
 290
 291 static inline u32 tb_dp_cap_get_rate(u32 val)
 292 {
 293         u32 rate = (val & DP_COMMON_CAP_RATE_MASK) >> DP_COMMON_CAP_RATE_SHIFT;
 294
 295         switch (rate) {
 296         case DP_COMMON_CAP_RATE_RBR:
 297                 return 1620;
 298         case DP_COMMON_CAP_RATE_HBR:
 299                 return 2700;
 300         case DP_COMMON_CAP_RATE_HBR2:
 301                 return 5400;
 302         case DP_COMMON_CAP_RATE_HBR3:
 303                 return 8100;
 304         default:
 305                 return 0;
 306         }
 307 }
 308
 309 static inline u32 tb_dp_cap_set_rate(u32 val, u32 rate)
 310 {
 311         val &= ~DP_COMMON_CAP_RATE_MASK;
 312         switch (rate) {
 313         default:
 314                 WARN(1, "invalid rate %u passed, defaulting to 1620 MB/s\n", rate);
 315                 fallthrough;
 316         case 1620:
 317                 val |= DP_COMMON_CAP_RATE_RBR << DP_COMMON_CAP_RATE_SHIFT;
 318                 break;
 319         case 2700:
 320                 val |= DP_COMMON_CAP_RATE_HBR << DP_COMMON_CAP_RATE_SHIFT;
 321                 break;
 322         case 5400:
 323                 val |= DP_COMMON_CAP_RATE_HBR2 << DP_COMMON_CAP_RATE_SHIFT;
 324                 break;
 325         case 8100:
 326                 val |= DP_COMMON_CAP_RATE_HBR3 << DP_COMMON_CAP_RATE_SHIFT;
 327                 break;
 328         }
 329         return val;
 330 }
 331
 332 static inline u32 tb_dp_cap_get_lanes(u32 val)
 333 {
 334         u32 lanes = (val & DP_COMMON_CAP_LANES_MASK) >> DP_COMMON_CAP_LANES_SHIFT;
 335
 336         switch (lanes) {
 337         case DP_COMMON_CAP_1_LANE:
 338                 return 1;
 339         case DP_COMMON_CAP_2_LANES:
 340                 return 2;
 341         case DP_COMMON_CAP_4_LANES:
 342                 return 4;
 343         default:
 344                 return 0;
 345         }
 346 }
 347
 348 static inline u32 tb_dp_cap_set_lanes(u32 val, u32 lanes)
 349 {
 350         val &= ~DP_COMMON_CAP_LANES_MASK;
 351         switch (lanes) {
 352         default:
 353                 WARN(1, "invalid number of lanes %u passed, defaulting to 1\n",
 354                      lanes);
 355                 fallthrough;
 356         case 1:
 357                 val |= DP_COMMON_CAP_1_LANE << DP_COMMON_CAP_LANES_SHIFT;
 358                 break;
 359         case 2:
 360                 val |= DP_COMMON_CAP_2_LANES << DP_COMMON_CAP_LANES_SHIFT;
 361                 break;
 362         case 4:
 363                 val |= DP_COMMON_CAP_4_LANES << DP_COMMON_CAP_LANES_SHIFT;
 364                 break;
 365         }
 366         return val;
 367 }
 368
 369 static unsigned int tb_dp_bandwidth(unsigned int rate, unsigned int lanes)
 370 {
 371         /* Tunneling removes the DP 8b/10b encoding */
 372         return rate * lanes * 8 / 10;
 373 }
 374
 375 static int tb_dp_reduce_bandwidth(int max_bw, u32 in_rate, u32 in_lanes,
 376                                   u32 out_rate, u32 out_lanes, u32 *new_rate,
 377                                   u32 *new_lanes)
 378 {
 379         static const u32 dp_bw[][2] = {
 380                 /* Mb/s, lanes */
 381                 { 8100, 4 }, /* 25920 Mb/s */
 382                 { 5400, 4 }, /* 17280 Mb/s */
 383                 { 8100, 2 }, /* 12960 Mb/s */
 384                 { 2700, 4 }, /* 8640 Mb/s */
 385                 { 5400, 2 }, /* 8640 Mb/s */
 386                 { 8100, 1 }, /* 6480 Mb/s */
 387                 { 1620, 4 }, /* 5184 Mb/s */
 388                 { 5400, 1 }, /* 4320 Mb/s */
 389                 { 2700, 2 }, /* 4320 Mb/s */
 390                 { 1620, 2 }, /* 2592 Mb/s */
 391                 { 2700, 1 }, /* 2160 Mb/s */
 392                 { 1620, 1 }, /* 1296 Mb/s */
 393         };
 394         unsigned int i;
 395
 396         /*
 397          * Find a combination that can fit into max_bw and does not
 398          * exceed the maximum rate and lanes supported by the DP OUT and
 399          * DP IN adapters.
 400          */
 401         for (i = 0; i < ARRAY_SIZE(dp_bw); i++) {
 402                 if (dp_bw[i][0] > out_rate || dp_bw[i][1] > out_lanes)
 403                         continue;
 404
 405                 if (dp_bw[i][0] > in_rate || dp_bw[i][1] > in_lanes)
 406                         continue;
 407
 408                 if (tb_dp_bandwidth(dp_bw[i][0], dp_bw[i][1]) <= max_bw) {
 409                         *new_rate = dp_bw[i][0];
 410                         *new_lanes = dp_bw[i][1];
 411                         return 0;
 412                 }
 413         }
 414
 415         return -ENOSR;
 416 }
 417
 418 static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
 419 {
 420         u32 out_dp_cap, out_rate, out_lanes, in_dp_cap, in_rate, in_lanes, bw;
 421         struct tb_port *out = tunnel->dst_port;
 422         struct tb_port *in = tunnel->src_port;
 423         int ret, max_bw;
 424
 425         /*
 426          * Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for
 427          * newer generation hardware.
 428          */
 429         if (in->sw->generation < 2 || out->sw->generation < 2)
 430                 return 0;
 431
 432         /*
 433          * Perform connection manager handshake between IN and OUT ports
 434          * before capabilities exchange can take place.
 435          */
 436         ret = tb_dp_cm_handshake(in, out);
 437         if (ret)
 438                 return ret;
 439
 440         /* Read both DP_LOCAL_CAP registers */
 441         ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
 442                            in->cap_adap + DP_LOCAL_CAP, 1);
 443         if (ret)
 444                 return ret;
 445
 446         ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
 447                            out->cap_adap + DP_LOCAL_CAP, 1);
 448         if (ret)
 449                 return ret;
 450
 451         /* Write IN local caps to OUT remote caps */
 452         ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT,
 453                             out->cap_adap + DP_REMOTE_CAP, 1);
 454         if (ret)
 455                 return ret;
 456
 457         in_rate = tb_dp_cap_get_rate(in_dp_cap);
 458         in_lanes = tb_dp_cap_get_lanes(in_dp_cap);
 459         tb_port_dbg(in, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
 460                     in_rate, in_lanes, tb_dp_bandwidth(in_rate, in_lanes));
 461
 462         /*
 463          * If the tunnel bandwidth is limited (max_bw is set) then see
 464          * if we need to reduce bandwidth to fit there.
 465          */
 466         out_rate = tb_dp_cap_get_rate(out_dp_cap);
 467         out_lanes = tb_dp_cap_get_lanes(out_dp_cap);
 468         bw = tb_dp_bandwidth(out_rate, out_lanes);
 469         tb_port_dbg(out, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
 470                     out_rate, out_lanes, bw);
 471
 472         if (in->sw->config.depth < out->sw->config.depth)
 473                 max_bw = tunnel->max_down;
 474         else
 475                 max_bw = tunnel->max_up;
 476
 477         if (max_bw && bw > max_bw) {
 478                 u32 new_rate, new_lanes, new_bw;
 479
 480                 ret = tb_dp_reduce_bandwidth(max_bw, in_rate, in_lanes,
 481                                              out_rate, out_lanes, &new_rate,
 482                                              &new_lanes);
 483                 if (ret) {
 484                         tb_port_info(out, "not enough bandwidth for DP tunnel\n");
 485                         return ret;
 486                 }
 487
 488                 new_bw = tb_dp_bandwidth(new_rate, new_lanes);
 489                 tb_port_dbg(out, "bandwidth reduced to %u Mb/s x%u = %u Mb/s\n",
 490                             new_rate, new_lanes, new_bw);
 491
 492                 /*
 493                  * Set new rate and number of lanes before writing it to
 494                  * the IN port remote caps.
 495                  */
 496                 out_dp_cap = tb_dp_cap_set_rate(out_dp_cap, new_rate);
 497                 out_dp_cap = tb_dp_cap_set_lanes(out_dp_cap, new_lanes);
 498         }
 499
 500         return tb_port_write(in, &out_dp_cap, TB_CFG_PORT,
 501                              in->cap_adap + DP_REMOTE_CAP, 1);
 502 }
 503
 504 static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
 505 {
 506         int ret;
 507
 508         if (active) {
 509                 struct tb_path **paths;
 510                 int last;
 511
 512                 paths = tunnel->paths;
 513                 last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;
 514
 515                 tb_dp_port_set_hops(tunnel->src_port,
 516                         paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,
 517                         paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,
 518                         paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);
 519
 520                 tb_dp_port_set_hops(tunnel->dst_port,
 521                         paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,
 522                         paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,
 523                         paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);
 524         } else {
 525                 tb_dp_port_hpd_clear(tunnel->src_port);
 526                 tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0);
 527                 if (tb_port_is_dpout(tunnel->dst_port))
 528                         tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0);
 529         }
 530
 531         ret = tb_dp_port_enable(tunnel->src_port, active);
 532         if (ret)
 533                 return ret;
 534
 535         if (tb_port_is_dpout(tunnel->dst_port))
 536                 return tb_dp_port_enable(tunnel->dst_port, active);
 537
 538         return 0;
 539 }
 540
 541 static int tb_dp_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
 542                                     int *consumed_down)
 543 {
 544         struct tb_port *in = tunnel->src_port;
 545         const struct tb_switch *sw = in->sw;
 546         u32 val, rate = 0, lanes = 0;
 547         int ret;
 548
 549         if (tb_dp_is_usb4(sw)) {
 550                 int timeout = 20;
 551
 552                 /*
 553                  * Wait for DPRX done. Normally it should be already set
 554                  * for active tunnel.
 555                  */
 556                 do {
 557                         ret = tb_port_read(in, &val, TB_CFG_PORT,
 558                                            in->cap_adap + DP_COMMON_CAP, 1);
 559                         if (ret)
 560                                 return ret;
 561
 562                         if (val & DP_COMMON_CAP_DPRX_DONE) {
 563                                 rate = tb_dp_cap_get_rate(val);
 564                                 lanes = tb_dp_cap_get_lanes(val);
 565                                 break;
 566                         }
 567                         msleep(250);
 568                 } while (timeout--);
 569
 570                 if (!timeout)
 571                         return -ETIMEDOUT;
 572         } else if (sw->generation >= 2) {
 573                 /*
 574                  * Read from the copied remote cap so that we take into
 575                  * account if capabilities were reduced during exchange.
 576                  */
 577                 ret = tb_port_read(in, &val, TB_CFG_PORT,
 578                                    in->cap_adap + DP_REMOTE_CAP, 1);
 579                 if (ret)
 580                         return ret;
 581
 582                 rate = tb_dp_cap_get_rate(val);
 583                 lanes = tb_dp_cap_get_lanes(val);
 584         } else {
 585                 /* No bandwidth management for legacy devices  */
 586                 *consumed_up = 0;
 587                 *consumed_down = 0;
 588                 return 0;
 589         }
 590
 591         if (in->sw->config.depth < tunnel->dst_port->sw->config.depth) {
 592                 *consumed_up = 0;
 593                 *consumed_down = tb_dp_bandwidth(rate, lanes);
 594         } else {
 595                 *consumed_up = tb_dp_bandwidth(rate, lanes);
 596                 *consumed_down = 0;
 597         }
 598
 599         return 0;
 600 }
 601
 602 static void tb_dp_init_aux_path(struct tb_path *path)
 603 {
 604         int i;
 605
 606         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
 607         path->egress_shared_buffer = TB_PATH_NONE;
 608         path->ingress_fc_enable = TB_PATH_ALL;
 609         path->ingress_shared_buffer = TB_PATH_NONE;
 610         path->priority = 2;
 611         path->weight = 1;
 612
 613         for (i = 0; i < path->path_length; i++)
 614                 path->hops[i].initial_credits = 1;
 615 }
 616
 617 static void tb_dp_init_video_path(struct tb_path *path, bool discover)
 618 {
 619         u32 nfc_credits = path->hops[0].in_port->config.nfc_credits;
 620
 621         path->egress_fc_enable = TB_PATH_NONE;
 622         path->egress_shared_buffer = TB_PATH_NONE;
 623         path->ingress_fc_enable = TB_PATH_NONE;
 624         path->ingress_shared_buffer = TB_PATH_NONE;
 625         path->priority = 1;
 626         path->weight = 1;
 627
 628         if (discover) {
 629                 path->nfc_credits = nfc_credits & ADP_CS_4_NFC_BUFFERS_MASK;
 630         } else {
 631                 u32 max_credits;
 632
 633                 max_credits = (nfc_credits & ADP_CS_4_TOTAL_BUFFERS_MASK) >>
 634                         ADP_CS_4_TOTAL_BUFFERS_SHIFT;
 635                 /* Leave some credits for AUX path */
 636                 path->nfc_credits = min(max_credits - 2, 12U);
 637         }
 638 }
 639
 640 /**
 641  * tb_tunnel_discover_dp() - Discover existing Display Port tunnels
 642  * @tb: Pointer to the domain structure
 643  * @in: DP in adapter
 644  *
 645  * If @in adapter is active, follows the tunnel to the DP out adapter
 646  * and back. Returns the discovered tunnel or %NULL if there was no
 647  * tunnel.
 648  *
 649  * Return: DP tunnel or %NULL if no tunnel found.
 650  */
 651 struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in)
 652 {
 653         struct tb_tunnel *tunnel;
 654         struct tb_port *port;
 655         struct tb_path *path;
 656
 657         if (!tb_dp_port_is_enabled(in))
 658                 return NULL;
 659
 660         tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
 661         if (!tunnel)
 662                 return NULL;
 663
 664         tunnel->init = tb_dp_xchg_caps;
 665         tunnel->activate = tb_dp_activate;
 666         tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
 667         tunnel->src_port = in;
 668
 669         path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1,
 670                                 &tunnel->dst_port, "Video");
 671         if (!path) {
 672                 /* Just disable the DP IN port */
 673                 tb_dp_port_enable(in, false);
 674                 goto err_free;
 675         }
 676         tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;
 677         tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT], true);
 678
 679         path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX");
 680         if (!path)
 681                 goto err_deactivate;
 682         tunnel->paths[TB_DP_AUX_PATH_OUT] = path;
 683         tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT]);
 684
 685         path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID,
 686                                 &port, "AUX RX");
 687         if (!path)
 688                 goto err_deactivate;
 689         tunnel->paths[TB_DP_AUX_PATH_IN] = path;
 690         tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN]);
 691
 692         /* Validate that the tunnel is complete */
 693         if (!tb_port_is_dpout(tunnel->dst_port)) {
 694                 tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");
 695                 goto err_deactivate;
 696         }
 697
 698         if (!tb_dp_port_is_enabled(tunnel->dst_port))
 699                 goto err_deactivate;
 700
 701         if (!tb_dp_port_hpd_is_active(tunnel->dst_port))
 702                 goto err_deactivate;
 703
 704         if (port != tunnel->src_port) {
 705                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
 706                 goto err_deactivate;
 707         }
 708
 709         tb_tunnel_dbg(tunnel, "discovered\n");
 710         return tunnel;
 711
 712 err_deactivate:
 713         tb_tunnel_deactivate(tunnel);
 714 err_free:
 715         tb_tunnel_free(tunnel);
 716
 717         return NULL;
 718 }
 719
 720 /**
 721  * tb_tunnel_alloc_dp() - allocate a Display Port tunnel
 722  * @tb: Pointer to the domain structure
 723  * @in: DP in adapter port
 724  * @out: DP out adapter port
 725  * @max_up: Maximum available upstream bandwidth for the DP tunnel (%0
 726  *          if not limited)
 727  * @max_down: Maximum available downstream bandwidth for the DP tunnel
 728  *            (%0 if not limited)
 729  *
 730  * Allocates a tunnel between @in and @out that is capable of tunneling
 731  * Display Port traffic.
 732  *
 733  * Return: Returns a tb_tunnel on success or NULL on failure.
 734  */
 735 struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
 736                                      struct tb_port *out, int max_up,
 737                                      int max_down)
 738 {
 739         struct tb_tunnel *tunnel;
 740         struct tb_path **paths;
 741         struct tb_path *path;
 742
 743         if (WARN_ON(!in->cap_adap || !out->cap_adap))
 744                 return NULL;
 745
 746         tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
 747         if (!tunnel)
 748                 return NULL;
 749
 750         tunnel->init = tb_dp_xchg_caps;
 751         tunnel->activate = tb_dp_activate;
 752         tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
 753         tunnel->src_port = in;
 754         tunnel->dst_port = out;
 755         tunnel->max_up = max_up;
 756         tunnel->max_down = max_down;
 757
 758         paths = tunnel->paths;
 759
 760         path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,
 761                              1, "Video");
 762         if (!path)
 763                 goto err_free;
 764         tb_dp_init_video_path(path, false);
 765         paths[TB_DP_VIDEO_PATH_OUT] = path;
 766
 767         path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
 768                              TB_DP_AUX_TX_HOPID, 1, "AUX TX");
 769         if (!path)
 770                 goto err_free;
 771         tb_dp_init_aux_path(path);
 772         paths[TB_DP_AUX_PATH_OUT] = path;
 773
 774         path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,
 775                              TB_DP_AUX_RX_HOPID, 1, "AUX RX");
 776         if (!path)
 777                 goto err_free;
 778         tb_dp_init_aux_path(path);
 779         paths[TB_DP_AUX_PATH_IN] = path;
 780
 781         return tunnel;
 782
 783 err_free:
 784         tb_tunnel_free(tunnel);
 785         return NULL;
 786 }
 787
 788 static u32 tb_dma_credits(struct tb_port *nhi)
 789 {
 790         u32 max_credits;
 791
 792         max_credits = (nhi->config.nfc_credits & ADP_CS_4_TOTAL_BUFFERS_MASK) >>
 793                 ADP_CS_4_TOTAL_BUFFERS_SHIFT;
 794         return min(max_credits, 13U);
 795 }
 796
 797 static void tb_dma_init_path(struct tb_path *path, unsigned int efc, u32 credits)
 798 {
 799         int i;
 800
 801         path->egress_fc_enable = efc;
 802         path->ingress_fc_enable = TB_PATH_ALL;
 803         path->egress_shared_buffer = TB_PATH_NONE;
 804         path->ingress_shared_buffer = TB_PATH_NONE;
 805         path->priority = 5;
 806         path->weight = 1;
 807         path->clear_fc = true;
 808
 809         for (i = 0; i < path->path_length; i++)
 810                 path->hops[i].initial_credits = credits;
 811 }
 812
 813 /**
 814  * tb_tunnel_alloc_dma() - allocate a DMA tunnel
 815  * @tb: Pointer to the domain structure
 816  * @nhi: Host controller port
 817  * @dst: Destination null port which the other domain is connected to
 818  * @transmit_path: HopID used for transmitting packets
 819  * @transmit_ring: NHI ring number used to send packets towards the
 820  *                 other domain. Set to %-1 if TX path is not needed.
 821  * @receive_path: HopID used for receiving packets
 822  * @receive_ring: NHI ring number used to receive packets from the
 823  *                other domain. Set to %-1 if RX path is not needed.
 824  *
 825  * Return: Returns a tb_tunnel on success or NULL on failure.
 826  */
 827 struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
 828                                       struct tb_port *dst, int transmit_path,
 829                                       int transmit_ring, int receive_path,
 830                                       int receive_ring)
 831 {
 832         struct tb_tunnel *tunnel;
 833         size_t npaths = 0, i = 0;
 834         struct tb_path *path;
 835         u32 credits;
 836
 837         if (receive_ring > 0)
 838                 npaths++;
 839         if (transmit_ring > 0)
 840                 npaths++;
 841
 842         if (WARN_ON(!npaths))
 843                 return NULL;
 844
 845         tunnel = tb_tunnel_alloc(tb, npaths, TB_TUNNEL_DMA);
 846         if (!tunnel)
 847                 return NULL;
 848
 849         tunnel->src_port = nhi;
 850         tunnel->dst_port = dst;
 851
 852         credits = tb_dma_credits(nhi);
 853
 854         if (receive_ring > 0) {
 855                 path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0,
 856                                      "DMA RX");
 857                 if (!path) {
 858                         tb_tunnel_free(tunnel);
 859                         return NULL;
 860                 }
 861                 tb_dma_init_path(path, TB_PATH_SOURCE | TB_PATH_INTERNAL, credits);
 862                 tunnel->paths[i++] = path;
 863         }
 864
 865         if (transmit_ring > 0) {
 866                 path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0,
 867                                      "DMA TX");
 868                 if (!path) {
 869                         tb_tunnel_free(tunnel);
 870                         return NULL;
 871                 }
 872                 tb_dma_init_path(path, TB_PATH_ALL, credits);
 873                 tunnel->paths[i++] = path;
 874         }
 875
 876         return tunnel;
 877 }
 878
 879 /**
 880  * tb_tunnel_match_dma() - Match DMA tunnel
 881  * @tunnel: Tunnel to match
 882  * @transmit_path: HopID used for transmitting packets. Pass %-1 to ignore.
 883  * @transmit_ring: NHI ring number used to send packets towards the
 884  *                 other domain. Pass %-1 to ignore.
 885  * @receive_path: HopID used for receiving packets. Pass %-1 to ignore.
 886  * @receive_ring: NHI ring number used to receive packets from the
 887  *                other domain. Pass %-1 to ignore.
 888  *
 889  * This function can be used to match specific DMA tunnel, if there are
 890  * multiple DMA tunnels going through the same XDomain connection.
 891  * Returns true if there is match and false otherwise.
 892  */
 893 bool tb_tunnel_match_dma(const struct tb_tunnel *tunnel, int transmit_path,
 894                          int transmit_ring, int receive_path, int receive_ring)
 895 {
 896         const struct tb_path *tx_path = NULL, *rx_path = NULL;
 897         int i;
 898
 899         if (!receive_ring || !transmit_ring)
 900                 return false;
 901
 902         for (i = 0; i < tunnel->npaths; i++) {
 903                 const struct tb_path *path = tunnel->paths[i];
 904
 905                 if (!path)
 906                         continue;
 907
 908                 if (tb_port_is_nhi(path->hops[0].in_port))
 909                         tx_path = path;
 910                 else if (tb_port_is_nhi(path->hops[path->path_length - 1].out_port))
 911                         rx_path = path;
 912         }
 913
 914         if (transmit_ring > 0 || transmit_path > 0) {
 915                 if (!tx_path)
 916                         return false;
 917                 if (transmit_ring > 0 &&
 918                     (tx_path->hops[0].in_hop_index != transmit_ring))
 919                         return false;
 920                 if (transmit_path > 0 &&
 921                     (tx_path->hops[tx_path->path_length - 1].next_hop_index != transmit_path))
 922                         return false;
 923         }
 924
 925         if (receive_ring > 0 || receive_path > 0) {
 926                 if (!rx_path)
 927                         return false;
 928                 if (receive_path > 0 &&
 929                     (rx_path->hops[0].in_hop_index != receive_path))
 930                         return false;
 931                 if (receive_ring > 0 &&
 932                     (rx_path->hops[rx_path->path_length - 1].next_hop_index != receive_ring))
 933                         return false;
 934         }
 935
 936         return true;
 937 }
 938
 939 static int tb_usb3_max_link_rate(struct tb_port *up, struct tb_port *down)
 940 {
 941         int ret, up_max_rate, down_max_rate;
 942
 943         ret = usb4_usb3_port_max_link_rate(up);
 944         if (ret < 0)
 945                 return ret;
 946         up_max_rate = ret;
 947
 948         ret = usb4_usb3_port_max_link_rate(down);
 949         if (ret < 0)
 950                 return ret;
 951         down_max_rate = ret;
 952
 953         return min(up_max_rate, down_max_rate);
 954 }
 955
 956 static int tb_usb3_init(struct tb_tunnel *tunnel)
 957 {
 958         tb_tunnel_dbg(tunnel, "allocating initial bandwidth %d/%d Mb/s\n",
 959                       tunnel->allocated_up, tunnel->allocated_down);
 960
 961         return usb4_usb3_port_allocate_bandwidth(tunnel->src_port,
 962                                                  &tunnel->allocated_up,
 963                                                  &tunnel->allocated_down);
 964 }
 965
 966 static int tb_usb3_activate(struct tb_tunnel *tunnel, bool activate)
 967 {
 968         int res;
 969
 970         res = tb_usb3_port_enable(tunnel->src_port, activate);
 971         if (res)
 972                 return res;
 973
 974         if (tb_port_is_usb3_up(tunnel->dst_port))
 975                 return tb_usb3_port_enable(tunnel->dst_port, activate);
 976
 977         return 0;
 978 }
 979
 980 static int tb_usb3_consumed_bandwidth(struct tb_tunnel *tunnel,
 981                 int *consumed_up, int *consumed_down)
 982 {
 983         int pcie_enabled = tb_acpi_may_tunnel_pcie();
 984
 985         /*
 986          * PCIe tunneling, if enabled, affects the USB3 bandwidth so
 987          * take that it into account here.
 988          */
 989         *consumed_up = tunnel->allocated_up * (3 + pcie_enabled) / 3;
 990         *consumed_down = tunnel->allocated_down * (3 + pcie_enabled) / 3;
 991         return 0;
 992 }
 993
 994 static int tb_usb3_release_unused_bandwidth(struct tb_tunnel *tunnel)
 995 {
 996         int ret;
 997
 998         ret = usb4_usb3_port_release_bandwidth(tunnel->src_port,
 999                                                &tunnel->allocated_up,
1000                                                &tunnel->allocated_down);
1001         if (ret)
1002                 return ret;
1003
1004         tb_tunnel_dbg(tunnel, "decreased bandwidth allocation to %d/%d Mb/s\n",
1005                       tunnel->allocated_up, tunnel->allocated_down);
1006         return 0;
1007 }
1008
1009 static void tb_usb3_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
1010                                                 int *available_up,
1011                                                 int *available_down)
1012 {
1013         int ret, max_rate, allocate_up, allocate_down;
1014
1015         ret = usb4_usb3_port_actual_link_rate(tunnel->src_port);
1016         if (ret < 0) {
1017                 tb_tunnel_warn(tunnel, "failed to read actual link rate\n");
1018                 return;
1019         } else if (!ret) {
1020                 /* Use maximum link rate if the link valid is not set */
1021                 ret = usb4_usb3_port_max_link_rate(tunnel->src_port);
1022                 if (ret < 0) {
1023                         tb_tunnel_warn(tunnel, "failed to read maximum link rate\n");
1024                         return;
1025                 }
1026         }
1027
1028         /*
1029          * 90% of the max rate can be allocated for isochronous
1030          * transfers.
1031          */
1032         max_rate = ret * 90 / 100;
1033
1034         /* No need to reclaim if already at maximum */
1035         if (tunnel->allocated_up >= max_rate &&
1036             tunnel->allocated_down >= max_rate)
1037                 return;
1038
1039         /* Don't go lower than what is already allocated */
1040         allocate_up = min(max_rate, *available_up);
1041         if (allocate_up < tunnel->allocated_up)
1042                 allocate_up = tunnel->allocated_up;
1043
1044         allocate_down = min(max_rate, *available_down);
1045         if (allocate_down < tunnel->allocated_down)
1046                 allocate_down = tunnel->allocated_down;
1047
1048         /* If no changes no need to do more */
1049         if (allocate_up == tunnel->allocated_up &&
1050             allocate_down == tunnel->allocated_down)
1051                 return;
1052
1053         ret = usb4_usb3_port_allocate_bandwidth(tunnel->src_port, &allocate_up,
1054                                                 &allocate_down);
1055         if (ret) {
1056                 tb_tunnel_info(tunnel, "failed to allocate bandwidth\n");
1057                 return;
1058         }
1059
1060         tunnel->allocated_up = allocate_up;
1061         *available_up -= tunnel->allocated_up;
1062
1063         tunnel->allocated_down = allocate_down;
1064         *available_down -= tunnel->allocated_down;
1065
1066         tb_tunnel_dbg(tunnel, "increased bandwidth allocation to %d/%d Mb/s\n",
1067                       tunnel->allocated_up, tunnel->allocated_down);
1068 }
1069
1070 static void tb_usb3_init_path(struct tb_path *path)
1071 {
1072         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1073         path->egress_shared_buffer = TB_PATH_NONE;
1074         path->ingress_fc_enable = TB_PATH_ALL;
1075         path->ingress_shared_buffer = TB_PATH_NONE;
1076         path->priority = 3;
1077         path->weight = 3;
1078         path->drop_packages = 0;
1079         path->nfc_credits = 0;
1080         path->hops[0].initial_credits = 7;
1081         if (path->path_length > 1)
1082                 path->hops[1].initial_credits =
1083                         tb_initial_credits(path->hops[1].in_port->sw);
1084 }
1085
1086 /**
1087  * tb_tunnel_discover_usb3() - Discover existing USB3 tunnels
1088  * @tb: Pointer to the domain structure
1089  * @down: USB3 downstream adapter
1090  *
1091  * If @down adapter is active, follows the tunnel to the USB3 upstream
1092  * adapter and back. Returns the discovered tunnel or %NULL if there was
1093  * no tunnel.
1094  */
1095 struct tb_tunnel *tb_tunnel_discover_usb3(struct tb *tb, struct tb_port *down)
1096 {
1097         struct tb_tunnel *tunnel;
1098         struct tb_path *path;
1099
1100         if (!tb_usb3_port_is_enabled(down))
1101                 return NULL;
1102
1103         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
1104         if (!tunnel)
1105                 return NULL;
1106
1107         tunnel->activate = tb_usb3_activate;
1108         tunnel->src_port = down;
1109
1110         /*
1111          * Discover both paths even if they are not complete. We will
1112          * clean them up by calling tb_tunnel_deactivate() below in that
1113          * case.
1114          */
1115         path = tb_path_discover(down, TB_USB3_HOPID, NULL, -1,
1116                                 &tunnel->dst_port, "USB3 Down");
1117         if (!path) {
1118                 /* Just disable the downstream port */
1119                 tb_usb3_port_enable(down, false);
1120                 goto err_free;
1121         }
1122         tunnel->paths[TB_USB3_PATH_DOWN] = path;
1123         tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_DOWN]);
1124
1125         path = tb_path_discover(tunnel->dst_port, -1, down, TB_USB3_HOPID, NULL,
1126                                 "USB3 Up");
1127         if (!path)
1128                 goto err_deactivate;
1129         tunnel->paths[TB_USB3_PATH_UP] = path;
1130         tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_UP]);
1131
1132         /* Validate that the tunnel is complete */
1133         if (!tb_port_is_usb3_up(tunnel->dst_port)) {
1134                 tb_port_warn(tunnel->dst_port,
1135                              "path does not end on an USB3 adapter, cleaning up\n");
1136                 goto err_deactivate;
1137         }
1138
1139         if (down != tunnel->src_port) {
1140                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
1141                 goto err_deactivate;
1142         }
1143
1144         if (!tb_usb3_port_is_enabled(tunnel->dst_port)) {
1145                 tb_tunnel_warn(tunnel,
1146                                "tunnel is not fully activated, cleaning up\n");
1147                 goto err_deactivate;
1148         }
1149
1150         if (!tb_route(down->sw)) {
1151                 int ret;
1152
1153                 /*
1154                  * Read the initial bandwidth allocation for the first
1155                  * hop tunnel.
1156                  */
1157                 ret = usb4_usb3_port_allocated_bandwidth(down,
1158                         &tunnel->allocated_up, &tunnel->allocated_down);
1159                 if (ret)
1160                         goto err_deactivate;
1161
1162                 tb_tunnel_dbg(tunnel, "currently allocated bandwidth %d/%d Mb/s\n",
1163                               tunnel->allocated_up, tunnel->allocated_down);
1164
1165                 tunnel->init = tb_usb3_init;
1166                 tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
1167                 tunnel->release_unused_bandwidth =
1168                         tb_usb3_release_unused_bandwidth;
1169                 tunnel->reclaim_available_bandwidth =
1170                         tb_usb3_reclaim_available_bandwidth;
1171         }
1172
1173         tb_tunnel_dbg(tunnel, "discovered\n");
1174         return tunnel;
1175
1176 err_deactivate:
1177         tb_tunnel_deactivate(tunnel);
1178 err_free:
1179         tb_tunnel_free(tunnel);
1180
1181         return NULL;
1182 }
1183
1184 /**
1185  * tb_tunnel_alloc_usb3() - allocate a USB3 tunnel
1186  * @tb: Pointer to the domain structure
1187  * @up: USB3 upstream adapter port
1188  * @down: USB3 downstream adapter port
1189  * @max_up: Maximum available upstream bandwidth for the USB3 tunnel (%0
1190  *          if not limited).
1191  * @max_down: Maximum available downstream bandwidth for the USB3 tunnel
1192  *            (%0 if not limited).
1193  *
1194  * Allocate an USB3 tunnel. The ports must be of type @TB_TYPE_USB3_UP and
1195  * @TB_TYPE_USB3_DOWN.
1196  *
1197  * Return: Returns a tb_tunnel on success or %NULL on failure.
1198  */
1199 struct tb_tunnel *tb_tunnel_alloc_usb3(struct tb *tb, struct tb_port *up,
1200                                        struct tb_port *down, int max_up,
1201                                        int max_down)
1202 {
1203         struct tb_tunnel *tunnel;
1204         struct tb_path *path;
1205         int max_rate = 0;
1206
1207         /*
1208          * Check that we have enough bandwidth available for the new
1209          * USB3 tunnel.
1210          */
1211         if (max_up > 0 || max_down > 0) {
1212                 max_rate = tb_usb3_max_link_rate(down, up);
1213                 if (max_rate < 0)
1214                         return NULL;
1215
1216                 /* Only 90% can be allocated for USB3 isochronous transfers */
1217                 max_rate = max_rate * 90 / 100;
1218                 tb_port_dbg(up, "required bandwidth for USB3 tunnel %d Mb/s\n",
1219                             max_rate);
1220
1221                 if (max_rate > max_up || max_rate > max_down) {
1222                         tb_port_warn(up, "not enough bandwidth for USB3 tunnel\n");
1223                         return NULL;
1224                 }
1225         }
1226
1227         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
1228         if (!tunnel)
1229                 return NULL;
1230
1231         tunnel->activate = tb_usb3_activate;
1232         tunnel->src_port = down;
1233         tunnel->dst_port = up;
1234         tunnel->max_up = max_up;
1235         tunnel->max_down = max_down;
1236
1237         path = tb_path_alloc(tb, down, TB_USB3_HOPID, up, TB_USB3_HOPID, 0,
1238                              "USB3 Down");
1239         if (!path) {
1240                 tb_tunnel_free(tunnel);
1241                 return NULL;
1242         }
1243         tb_usb3_init_path(path);
1244         tunnel->paths[TB_USB3_PATH_DOWN] = path;
1245
1246         path = tb_path_alloc(tb, up, TB_USB3_HOPID, down, TB_USB3_HOPID, 0,
1247                              "USB3 Up");
1248         if (!path) {
1249                 tb_tunnel_free(tunnel);
1250                 return NULL;
1251         }
1252         tb_usb3_init_path(path);
1253         tunnel->paths[TB_USB3_PATH_UP] = path;
1254
1255         if (!tb_route(down->sw)) {
1256                 tunnel->allocated_up = max_rate;
1257                 tunnel->allocated_down = max_rate;
1258
1259                 tunnel->init = tb_usb3_init;
1260                 tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
1261                 tunnel->release_unused_bandwidth =
1262                         tb_usb3_release_unused_bandwidth;
1263                 tunnel->reclaim_available_bandwidth =
1264                         tb_usb3_reclaim_available_bandwidth;
1265         }
1266
1267         return tunnel;
1268 }
1269
1270 /**
1271  * tb_tunnel_free() - free a tunnel
1272  * @tunnel: Tunnel to be freed
1273  *
1274  * Frees a tunnel. The tunnel does not need to be deactivated.
1275  */
1276 void tb_tunnel_free(struct tb_tunnel *tunnel)
1277 {
1278         int i;
1279
1280         if (!tunnel)
1281                 return;
1282
1283         for (i = 0; i < tunnel->npaths; i++) {
1284                 if (tunnel->paths[i])
1285                         tb_path_free(tunnel->paths[i]);
1286         }
1287
1288         kfree(tunnel->paths);
1289         kfree(tunnel);
1290 }
1291
1292 /**
1293  * tb_tunnel_is_invalid - check whether an activated path is still valid
1294  * @tunnel: Tunnel to check
1295  */
1296 bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
1297 {
1298         int i;
1299
1300         for (i = 0; i < tunnel->npaths; i++) {
1301                 WARN_ON(!tunnel->paths[i]->activated);
1302                 if (tb_path_is_invalid(tunnel->paths[i]))
1303                         return true;
1304         }
1305
1306         return false;
1307 }
1308
1309 /**
1310  * tb_tunnel_restart() - activate a tunnel after a hardware reset
1311  * @tunnel: Tunnel to restart
1312  *
1313  * Return: 0 on success and negative errno in case if failure
1314  */
1315 int tb_tunnel_restart(struct tb_tunnel *tunnel)
1316 {
1317         int res, i;
1318
1319         tb_tunnel_dbg(tunnel, "activating\n");
1320
1321         /*
1322          * Make sure all paths are properly disabled before enabling
1323          * them again.
1324          */
1325         for (i = 0; i < tunnel->npaths; i++) {
1326                 if (tunnel->paths[i]->activated) {
1327                         tb_path_deactivate(tunnel->paths[i]);
1328                         tunnel->paths[i]->activated = false;
1329                 }
1330         }
1331
1332         if (tunnel->init) {
1333                 res = tunnel->init(tunnel);
1334                 if (res)
1335                         return res;
1336         }
1337
1338         for (i = 0; i < tunnel->npaths; i++) {
1339                 res = tb_path_activate(tunnel->paths[i]);
1340                 if (res)
1341                         goto err;
1342         }
1343
1344         if (tunnel->activate) {
1345                 res = tunnel->activate(tunnel, true);
1346                 if (res)
1347                         goto err;
1348         }
1349
1350         return 0;
1351
1352 err:
1353         tb_tunnel_warn(tunnel, "activation failed\n");
1354         tb_tunnel_deactivate(tunnel);
1355         return res;
1356 }
1357
1358 /**
1359  * tb_tunnel_activate() - activate a tunnel
1360  * @tunnel: Tunnel to activate
1361  *
1362  * Return: Returns 0 on success or an error code on failure.
1363  */
1364 int tb_tunnel_activate(struct tb_tunnel *tunnel)
1365 {
1366         int i;
1367
1368         for (i = 0; i < tunnel->npaths; i++) {
1369                 if (tunnel->paths[i]->activated) {
1370                         tb_tunnel_WARN(tunnel,
1371                                        "trying to activate an already activated tunnel\n");
1372                         return -EINVAL;
1373                 }
1374         }
1375
1376         return tb_tunnel_restart(tunnel);
1377 }
1378
1379 /**
1380  * tb_tunnel_deactivate() - deactivate a tunnel
1381  * @tunnel: Tunnel to deactivate
1382  */
1383 void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
1384 {
1385         int i;
1386
1387         tb_tunnel_dbg(tunnel, "deactivating\n");
1388
1389         if (tunnel->activate)
1390                 tunnel->activate(tunnel, false);
1391
1392         for (i = 0; i < tunnel->npaths; i++) {
1393                 if (tunnel->paths[i] && tunnel->paths[i]->activated)
1394                         tb_path_deactivate(tunnel->paths[i]);
1395         }
1396 }
1397
1398 /**
1399  * tb_tunnel_port_on_path() - Does the tunnel go through port
1400  * @tunnel: Tunnel to check
1401  * @port: Port to check
1402  *
1403  * Returns true if @tunnel goes through @port (direction does not matter),
1404  * false otherwise.
1405  */
1406 bool tb_tunnel_port_on_path(const struct tb_tunnel *tunnel,
1407                             const struct tb_port *port)
1408 {
1409         int i;
1410
1411         for (i = 0; i < tunnel->npaths; i++) {
1412                 if (!tunnel->paths[i])
1413                         continue;
1414
1415                 if (tb_path_port_on_path(tunnel->paths[i], port))
1416                         return true;
1417         }
1418
1419         return false;
1420 }
1421
1422 static bool tb_tunnel_is_active(const struct tb_tunnel *tunnel)
1423 {
1424         int i;
1425
1426         for (i = 0; i < tunnel->npaths; i++) {
1427                 if (!tunnel->paths[i])
1428                         return false;
1429                 if (!tunnel->paths[i]->activated)
1430                         return false;
1431         }
1432
1433         return true;
1434 }
1435
1436 /**
1437  * tb_tunnel_consumed_bandwidth() - Return bandwidth consumed by the tunnel
1438  * @tunnel: Tunnel to check
1439  * @consumed_up: Consumed bandwidth in Mb/s from @dst_port to @src_port.
1440  *               Can be %NULL.
1441  * @consumed_down: Consumed bandwidth in Mb/s from @src_port to @dst_port.
1442  *                 Can be %NULL.
1443  *
1444  * Stores the amount of isochronous bandwidth @tunnel consumes in
1445  * @consumed_up and @consumed_down. In case of success returns %0,
1446  * negative errno otherwise.
1447  */
1448 int tb_tunnel_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
1449                                  int *consumed_down)
1450 {
1451         int up_bw = 0, down_bw = 0;
1452
1453         if (!tb_tunnel_is_active(tunnel))
1454                 goto out;
1455
1456         if (tunnel->consumed_bandwidth) {
1457                 int ret;
1458
1459                 ret = tunnel->consumed_bandwidth(tunnel, &up_bw, &down_bw);
1460                 if (ret)
1461                         return ret;
1462
1463                 tb_tunnel_dbg(tunnel, "consumed bandwidth %d/%d Mb/s\n", up_bw,
1464                               down_bw);
1465         }
1466
1467 out:
1468         if (consumed_up)
1469                 *consumed_up = up_bw;
1470         if (consumed_down)
1471                 *consumed_down = down_bw;
1472
1473         return 0;
1474 }
1475
1476 /**
1477  * tb_tunnel_release_unused_bandwidth() - Release unused bandwidth
1478  * @tunnel: Tunnel whose unused bandwidth to release
1479  *
1480  * If tunnel supports dynamic bandwidth management (USB3 tunnels at the
1481  * moment) this function makes it to release all the unused bandwidth.
1482  *
1483  * Returns %0 in case of success and negative errno otherwise.
1484  */
1485 int tb_tunnel_release_unused_bandwidth(struct tb_tunnel *tunnel)
1486 {
1487         if (!tb_tunnel_is_active(tunnel))
1488                 return 0;
1489
1490         if (tunnel->release_unused_bandwidth) {
1491                 int ret;
1492
1493                 ret = tunnel->release_unused_bandwidth(tunnel);
1494                 if (ret)
1495                         return ret;
1496         }
1497
1498         return 0;
1499 }
1500
1501 /**
1502  * tb_tunnel_reclaim_available_bandwidth() - Reclaim available bandwidth
1503  * @tunnel: Tunnel reclaiming available bandwidth
1504  * @available_up: Available upstream bandwidth (in Mb/s)
1505  * @available_down: Available downstream bandwidth (in Mb/s)
1506  *
1507  * Reclaims bandwidth from @available_up and @available_down and updates
1508  * the variables accordingly (e.g decreases both according to what was
1509  * reclaimed by the tunnel). If nothing was reclaimed the values are
1510  * kept as is.
1511  */
1512 void tb_tunnel_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
1513                                            int *available_up,
1514                                            int *available_down)
1515 {
1516         if (!tb_tunnel_is_active(tunnel))
1517                 return;
1518
1519         if (tunnel->reclaim_available_bandwidth)
1520                 tunnel->reclaim_available_bandwidth(tunnel, available_up,
1521                                                     available_down);
1522 }