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 int tb_dma_activate(struct tb_tunnel *tunnel, bool active)
 798 {
 799         struct tb_port *nhi = tunnel->src_port;
 800         u32 credits;
 801
 802         credits = active ? tb_dma_credits(nhi) : 0;
 803         return tb_port_set_initial_credits(nhi, credits);
 804 }
 805
 806 static void tb_dma_init_path(struct tb_path *path, unsigned int isb,
 807                              unsigned int efc, u32 credits)
 808 {
 809         int i;
 810
 811         path->egress_fc_enable = efc;
 812         path->ingress_fc_enable = TB_PATH_ALL;
 813         path->egress_shared_buffer = TB_PATH_NONE;
 814         path->ingress_shared_buffer = isb;
 815         path->priority = 5;
 816         path->weight = 1;
 817         path->clear_fc = true;
 818
 819         for (i = 0; i < path->path_length; i++)
 820                 path->hops[i].initial_credits = credits;
 821 }
 822
 823 /**
 824  * tb_tunnel_alloc_dma() - allocate a DMA tunnel
 825  * @tb: Pointer to the domain structure
 826  * @nhi: Host controller port
 827  * @dst: Destination null port which the other domain is connected to
 828  * @transmit_ring: NHI ring number used to send packets towards the
 829  *                 other domain. Set to %0 if TX path is not needed.
 830  * @transmit_path: HopID used for transmitting packets
 831  * @receive_ring: NHI ring number used to receive packets from the
 832  *                other domain. Set to %0 if RX path is not needed.
 833  * @receive_path: HopID used for receiving packets
 834  *
 835  * Return: Returns a tb_tunnel on success or NULL on failure.
 836  */
 837 struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
 838                                       struct tb_port *dst, int transmit_ring,
 839                                       int transmit_path, int receive_ring,
 840                                       int receive_path)
 841 {
 842         struct tb_tunnel *tunnel;
 843         size_t npaths = 0, i = 0;
 844         struct tb_path *path;
 845         u32 credits;
 846
 847         if (receive_ring)
 848                 npaths++;
 849         if (transmit_ring)
 850                 npaths++;
 851
 852         if (WARN_ON(!npaths))
 853                 return NULL;
 854
 855         tunnel = tb_tunnel_alloc(tb, npaths, TB_TUNNEL_DMA);
 856         if (!tunnel)
 857                 return NULL;
 858
 859         tunnel->activate = tb_dma_activate;
 860         tunnel->src_port = nhi;
 861         tunnel->dst_port = dst;
 862
 863         credits = tb_dma_credits(nhi);
 864
 865         if (receive_ring) {
 866                 path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0,
 867                                      "DMA RX");
 868                 if (!path) {
 869                         tb_tunnel_free(tunnel);
 870                         return NULL;
 871                 }
 872                 tb_dma_init_path(path, TB_PATH_NONE, TB_PATH_SOURCE | TB_PATH_INTERNAL,
 873                                  credits);
 874                 tunnel->paths[i++] = path;
 875         }
 876
 877         if (transmit_ring) {
 878                 path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0,
 879                                      "DMA TX");
 880                 if (!path) {
 881                         tb_tunnel_free(tunnel);
 882                         return NULL;
 883                 }
 884                 tb_dma_init_path(path, TB_PATH_SOURCE, TB_PATH_ALL, credits);
 885                 tunnel->paths[i++] = path;
 886         }
 887
 888         return tunnel;
 889 }
 890
 891 static int tb_usb3_max_link_rate(struct tb_port *up, struct tb_port *down)
 892 {
 893         int ret, up_max_rate, down_max_rate;
 894
 895         ret = usb4_usb3_port_max_link_rate(up);
 896         if (ret < 0)
 897                 return ret;
 898         up_max_rate = ret;
 899
 900         ret = usb4_usb3_port_max_link_rate(down);
 901         if (ret < 0)
 902                 return ret;
 903         down_max_rate = ret;
 904
 905         return min(up_max_rate, down_max_rate);
 906 }
 907
 908 static int tb_usb3_init(struct tb_tunnel *tunnel)
 909 {
 910         tb_tunnel_dbg(tunnel, "allocating initial bandwidth %d/%d Mb/s\n",
 911                       tunnel->allocated_up, tunnel->allocated_down);
 912
 913         return usb4_usb3_port_allocate_bandwidth(tunnel->src_port,
 914                                                  &tunnel->allocated_up,
 915                                                  &tunnel->allocated_down);
 916 }
 917
 918 static int tb_usb3_activate(struct tb_tunnel *tunnel, bool activate)
 919 {
 920         int res;
 921
 922         res = tb_usb3_port_enable(tunnel->src_port, activate);
 923         if (res)
 924                 return res;
 925
 926         if (tb_port_is_usb3_up(tunnel->dst_port))
 927                 return tb_usb3_port_enable(tunnel->dst_port, activate);
 928
 929         return 0;
 930 }
 931
 932 static int tb_usb3_consumed_bandwidth(struct tb_tunnel *tunnel,
 933                 int *consumed_up, int *consumed_down)
 934 {
 935         int pcie_enabled = tb_acpi_may_tunnel_pcie();
 936
 937         /*
 938          * PCIe tunneling, if enabled, affects the USB3 bandwidth so
 939          * take that it into account here.
 940          */
 941         *consumed_up = tunnel->allocated_up * (3 + pcie_enabled) / 3;
 942         *consumed_down = tunnel->allocated_down * (3 + pcie_enabled) / 3;
 943         return 0;
 944 }
 945
 946 static int tb_usb3_release_unused_bandwidth(struct tb_tunnel *tunnel)
 947 {
 948         int ret;
 949
 950         ret = usb4_usb3_port_release_bandwidth(tunnel->src_port,
 951                                                &tunnel->allocated_up,
 952                                                &tunnel->allocated_down);
 953         if (ret)
 954                 return ret;
 955
 956         tb_tunnel_dbg(tunnel, "decreased bandwidth allocation to %d/%d Mb/s\n",
 957                       tunnel->allocated_up, tunnel->allocated_down);
 958         return 0;
 959 }
 960
 961 static void tb_usb3_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
 962                                                 int *available_up,
 963                                                 int *available_down)
 964 {
 965         int ret, max_rate, allocate_up, allocate_down;
 966
 967         ret = usb4_usb3_port_actual_link_rate(tunnel->src_port);
 968         if (ret < 0) {
 969                 tb_tunnel_warn(tunnel, "failed to read actual link rate\n");
 970                 return;
 971         } else if (!ret) {
 972                 /* Use maximum link rate if the link valid is not set */
 973                 ret = usb4_usb3_port_max_link_rate(tunnel->src_port);
 974                 if (ret < 0) {
 975                         tb_tunnel_warn(tunnel, "failed to read maximum link rate\n");
 976                         return;
 977                 }
 978         }
 979
 980         /*
 981          * 90% of the max rate can be allocated for isochronous
 982          * transfers.
 983          */
 984         max_rate = ret * 90 / 100;
 985
 986         /* No need to reclaim if already at maximum */
 987         if (tunnel->allocated_up >= max_rate &&
 988             tunnel->allocated_down >= max_rate)
 989                 return;
 990
 991         /* Don't go lower than what is already allocated */
 992         allocate_up = min(max_rate, *available_up);
 993         if (allocate_up < tunnel->allocated_up)
 994                 allocate_up = tunnel->allocated_up;
 995
 996         allocate_down = min(max_rate, *available_down);
 997         if (allocate_down < tunnel->allocated_down)
 998                 allocate_down = tunnel->allocated_down;
 999
1000         /* If no changes no need to do more */
1001         if (allocate_up == tunnel->allocated_up &&
1002             allocate_down == tunnel->allocated_down)
1003                 return;
1004
1005         ret = usb4_usb3_port_allocate_bandwidth(tunnel->src_port, &allocate_up,
1006                                                 &allocate_down);
1007         if (ret) {
1008                 tb_tunnel_info(tunnel, "failed to allocate bandwidth\n");
1009                 return;
1010         }
1011
1012         tunnel->allocated_up = allocate_up;
1013         *available_up -= tunnel->allocated_up;
1014
1015         tunnel->allocated_down = allocate_down;
1016         *available_down -= tunnel->allocated_down;
1017
1018         tb_tunnel_dbg(tunnel, "increased bandwidth allocation to %d/%d Mb/s\n",
1019                       tunnel->allocated_up, tunnel->allocated_down);
1020 }
1021
1022 static void tb_usb3_init_path(struct tb_path *path)
1023 {
1024         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1025         path->egress_shared_buffer = TB_PATH_NONE;
1026         path->ingress_fc_enable = TB_PATH_ALL;
1027         path->ingress_shared_buffer = TB_PATH_NONE;
1028         path->priority = 3;
1029         path->weight = 3;
1030         path->drop_packages = 0;
1031         path->nfc_credits = 0;
1032         path->hops[0].initial_credits = 7;
1033         if (path->path_length > 1)
1034                 path->hops[1].initial_credits =
1035                         tb_initial_credits(path->hops[1].in_port->sw);
1036 }
1037
1038 /**
1039  * tb_tunnel_discover_usb3() - Discover existing USB3 tunnels
1040  * @tb: Pointer to the domain structure
1041  * @down: USB3 downstream adapter
1042  *
1043  * If @down adapter is active, follows the tunnel to the USB3 upstream
1044  * adapter and back. Returns the discovered tunnel or %NULL if there was
1045  * no tunnel.
1046  */
1047 struct tb_tunnel *tb_tunnel_discover_usb3(struct tb *tb, struct tb_port *down)
1048 {
1049         struct tb_tunnel *tunnel;
1050         struct tb_path *path;
1051
1052         if (!tb_usb3_port_is_enabled(down))
1053                 return NULL;
1054
1055         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
1056         if (!tunnel)
1057                 return NULL;
1058
1059         tunnel->activate = tb_usb3_activate;
1060         tunnel->src_port = down;
1061
1062         /*
1063          * Discover both paths even if they are not complete. We will
1064          * clean them up by calling tb_tunnel_deactivate() below in that
1065          * case.
1066          */
1067         path = tb_path_discover(down, TB_USB3_HOPID, NULL, -1,
1068                                 &tunnel->dst_port, "USB3 Down");
1069         if (!path) {
1070                 /* Just disable the downstream port */
1071                 tb_usb3_port_enable(down, false);
1072                 goto err_free;
1073         }
1074         tunnel->paths[TB_USB3_PATH_DOWN] = path;
1075         tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_DOWN]);
1076
1077         path = tb_path_discover(tunnel->dst_port, -1, down, TB_USB3_HOPID, NULL,
1078                                 "USB3 Up");
1079         if (!path)
1080                 goto err_deactivate;
1081         tunnel->paths[TB_USB3_PATH_UP] = path;
1082         tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_UP]);
1083
1084         /* Validate that the tunnel is complete */
1085         if (!tb_port_is_usb3_up(tunnel->dst_port)) {
1086                 tb_port_warn(tunnel->dst_port,
1087                              "path does not end on an USB3 adapter, cleaning up\n");
1088                 goto err_deactivate;
1089         }
1090
1091         if (down != tunnel->src_port) {
1092                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
1093                 goto err_deactivate;
1094         }
1095
1096         if (!tb_usb3_port_is_enabled(tunnel->dst_port)) {
1097                 tb_tunnel_warn(tunnel,
1098                                "tunnel is not fully activated, cleaning up\n");
1099                 goto err_deactivate;
1100         }
1101
1102         if (!tb_route(down->sw)) {
1103                 int ret;
1104
1105                 /*
1106                  * Read the initial bandwidth allocation for the first
1107                  * hop tunnel.
1108                  */
1109                 ret = usb4_usb3_port_allocated_bandwidth(down,
1110                         &tunnel->allocated_up, &tunnel->allocated_down);
1111                 if (ret)
1112                         goto err_deactivate;
1113
1114                 tb_tunnel_dbg(tunnel, "currently allocated bandwidth %d/%d Mb/s\n",
1115                               tunnel->allocated_up, tunnel->allocated_down);
1116
1117                 tunnel->init = tb_usb3_init;
1118                 tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
1119                 tunnel->release_unused_bandwidth =
1120                         tb_usb3_release_unused_bandwidth;
1121                 tunnel->reclaim_available_bandwidth =
1122                         tb_usb3_reclaim_available_bandwidth;
1123         }
1124
1125         tb_tunnel_dbg(tunnel, "discovered\n");
1126         return tunnel;
1127
1128 err_deactivate:
1129         tb_tunnel_deactivate(tunnel);
1130 err_free:
1131         tb_tunnel_free(tunnel);
1132
1133         return NULL;
1134 }
1135
1136 /**
1137  * tb_tunnel_alloc_usb3() - allocate a USB3 tunnel
1138  * @tb: Pointer to the domain structure
1139  * @up: USB3 upstream adapter port
1140  * @down: USB3 downstream adapter port
1141  * @max_up: Maximum available upstream bandwidth for the USB3 tunnel (%0
1142  *          if not limited).
1143  * @max_down: Maximum available downstream bandwidth for the USB3 tunnel
1144  *            (%0 if not limited).
1145  *
1146  * Allocate an USB3 tunnel. The ports must be of type @TB_TYPE_USB3_UP and
1147  * @TB_TYPE_USB3_DOWN.
1148  *
1149  * Return: Returns a tb_tunnel on success or %NULL on failure.
1150  */
1151 struct tb_tunnel *tb_tunnel_alloc_usb3(struct tb *tb, struct tb_port *up,
1152                                        struct tb_port *down, int max_up,
1153                                        int max_down)
1154 {
1155         struct tb_tunnel *tunnel;
1156         struct tb_path *path;
1157         int max_rate = 0;
1158
1159         /*
1160          * Check that we have enough bandwidth available for the new
1161          * USB3 tunnel.
1162          */
1163         if (max_up > 0 || max_down > 0) {
1164                 max_rate = tb_usb3_max_link_rate(down, up);
1165                 if (max_rate < 0)
1166                         return NULL;
1167
1168                 /* Only 90% can be allocated for USB3 isochronous transfers */
1169                 max_rate = max_rate * 90 / 100;
1170                 tb_port_dbg(up, "required bandwidth for USB3 tunnel %d Mb/s\n",
1171                             max_rate);
1172
1173                 if (max_rate > max_up || max_rate > max_down) {
1174                         tb_port_warn(up, "not enough bandwidth for USB3 tunnel\n");
1175                         return NULL;
1176                 }
1177         }
1178
1179         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
1180         if (!tunnel)
1181                 return NULL;
1182
1183         tunnel->activate = tb_usb3_activate;
1184         tunnel->src_port = down;
1185         tunnel->dst_port = up;
1186         tunnel->max_up = max_up;
1187         tunnel->max_down = max_down;
1188
1189         path = tb_path_alloc(tb, down, TB_USB3_HOPID, up, TB_USB3_HOPID, 0,
1190                              "USB3 Down");
1191         if (!path) {
1192                 tb_tunnel_free(tunnel);
1193                 return NULL;
1194         }
1195         tb_usb3_init_path(path);
1196         tunnel->paths[TB_USB3_PATH_DOWN] = path;
1197
1198         path = tb_path_alloc(tb, up, TB_USB3_HOPID, down, TB_USB3_HOPID, 0,
1199                              "USB3 Up");
1200         if (!path) {
1201                 tb_tunnel_free(tunnel);
1202                 return NULL;
1203         }
1204         tb_usb3_init_path(path);
1205         tunnel->paths[TB_USB3_PATH_UP] = path;
1206
1207         if (!tb_route(down->sw)) {
1208                 tunnel->allocated_up = max_rate;
1209                 tunnel->allocated_down = max_rate;
1210
1211                 tunnel->init = tb_usb3_init;
1212                 tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
1213                 tunnel->release_unused_bandwidth =
1214                         tb_usb3_release_unused_bandwidth;
1215                 tunnel->reclaim_available_bandwidth =
1216                         tb_usb3_reclaim_available_bandwidth;
1217         }
1218
1219         return tunnel;
1220 }
1221
1222 /**
1223  * tb_tunnel_free() - free a tunnel
1224  * @tunnel: Tunnel to be freed
1225  *
1226  * Frees a tunnel. The tunnel does not need to be deactivated.
1227  */
1228 void tb_tunnel_free(struct tb_tunnel *tunnel)
1229 {
1230         int i;
1231
1232         if (!tunnel)
1233                 return;
1234
1235         for (i = 0; i < tunnel->npaths; i++) {
1236                 if (tunnel->paths[i])
1237                         tb_path_free(tunnel->paths[i]);
1238         }
1239
1240         kfree(tunnel->paths);
1241         kfree(tunnel);
1242 }
1243
1244 /**
1245  * tb_tunnel_is_invalid - check whether an activated path is still valid
1246  * @tunnel: Tunnel to check
1247  */
1248 bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
1249 {
1250         int i;
1251
1252         for (i = 0; i < tunnel->npaths; i++) {
1253                 WARN_ON(!tunnel->paths[i]->activated);
1254                 if (tb_path_is_invalid(tunnel->paths[i]))
1255                         return true;
1256         }
1257
1258         return false;
1259 }
1260
1261 /**
1262  * tb_tunnel_restart() - activate a tunnel after a hardware reset
1263  * @tunnel: Tunnel to restart
1264  *
1265  * Return: 0 on success and negative errno in case if failure
1266  */
1267 int tb_tunnel_restart(struct tb_tunnel *tunnel)
1268 {
1269         int res, i;
1270
1271         tb_tunnel_dbg(tunnel, "activating\n");
1272
1273         /*
1274          * Make sure all paths are properly disabled before enabling
1275          * them again.
1276          */
1277         for (i = 0; i < tunnel->npaths; i++) {
1278                 if (tunnel->paths[i]->activated) {
1279                         tb_path_deactivate(tunnel->paths[i]);
1280                         tunnel->paths[i]->activated = false;
1281                 }
1282         }
1283
1284         if (tunnel->init) {
1285                 res = tunnel->init(tunnel);
1286                 if (res)
1287                         return res;
1288         }
1289
1290         for (i = 0; i < tunnel->npaths; i++) {
1291                 res = tb_path_activate(tunnel->paths[i]);
1292                 if (res)
1293                         goto err;
1294         }
1295
1296         if (tunnel->activate) {
1297                 res = tunnel->activate(tunnel, true);
1298                 if (res)
1299                         goto err;
1300         }
1301
1302         return 0;
1303
1304 err:
1305         tb_tunnel_warn(tunnel, "activation failed\n");
1306         tb_tunnel_deactivate(tunnel);
1307         return res;
1308 }
1309
1310 /**
1311  * tb_tunnel_activate() - activate a tunnel
1312  * @tunnel: Tunnel to activate
1313  *
1314  * Return: Returns 0 on success or an error code on failure.
1315  */
1316 int tb_tunnel_activate(struct tb_tunnel *tunnel)
1317 {
1318         int i;
1319
1320         for (i = 0; i < tunnel->npaths; i++) {
1321                 if (tunnel->paths[i]->activated) {
1322                         tb_tunnel_WARN(tunnel,
1323                                        "trying to activate an already activated tunnel\n");
1324                         return -EINVAL;
1325                 }
1326         }
1327
1328         return tb_tunnel_restart(tunnel);
1329 }
1330
1331 /**
1332  * tb_tunnel_deactivate() - deactivate a tunnel
1333  * @tunnel: Tunnel to deactivate
1334  */
1335 void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
1336 {
1337         int i;
1338
1339         tb_tunnel_dbg(tunnel, "deactivating\n");
1340
1341         if (tunnel->activate)
1342                 tunnel->activate(tunnel, false);
1343
1344         for (i = 0; i < tunnel->npaths; i++) {
1345                 if (tunnel->paths[i] && tunnel->paths[i]->activated)
1346                         tb_path_deactivate(tunnel->paths[i]);
1347         }
1348 }
1349
1350 /**
1351  * tb_tunnel_port_on_path() - Does the tunnel go through port
1352  * @tunnel: Tunnel to check
1353  * @port: Port to check
1354  *
1355  * Returns true if @tunnel goes through @port (direction does not matter),
1356  * false otherwise.
1357  */
1358 bool tb_tunnel_port_on_path(const struct tb_tunnel *tunnel,
1359                             const struct tb_port *port)
1360 {
1361         int i;
1362
1363         for (i = 0; i < tunnel->npaths; i++) {
1364                 if (!tunnel->paths[i])
1365                         continue;
1366
1367                 if (tb_path_port_on_path(tunnel->paths[i], port))
1368                         return true;
1369         }
1370
1371         return false;
1372 }
1373
1374 static bool tb_tunnel_is_active(const struct tb_tunnel *tunnel)
1375 {
1376         int i;
1377
1378         for (i = 0; i < tunnel->npaths; i++) {
1379                 if (!tunnel->paths[i])
1380                         return false;
1381                 if (!tunnel->paths[i]->activated)
1382                         return false;
1383         }
1384
1385         return true;
1386 }
1387
1388 /**
1389  * tb_tunnel_consumed_bandwidth() - Return bandwidth consumed by the tunnel
1390  * @tunnel: Tunnel to check
1391  * @consumed_up: Consumed bandwidth in Mb/s from @dst_port to @src_port.
1392  *               Can be %NULL.
1393  * @consumed_down: Consumed bandwidth in Mb/s from @src_port to @dst_port.
1394  *                 Can be %NULL.
1395  *
1396  * Stores the amount of isochronous bandwidth @tunnel consumes in
1397  * @consumed_up and @consumed_down. In case of success returns %0,
1398  * negative errno otherwise.
1399  */
1400 int tb_tunnel_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
1401                                  int *consumed_down)
1402 {
1403         int up_bw = 0, down_bw = 0;
1404
1405         if (!tb_tunnel_is_active(tunnel))
1406                 goto out;
1407
1408         if (tunnel->consumed_bandwidth) {
1409                 int ret;
1410
1411                 ret = tunnel->consumed_bandwidth(tunnel, &up_bw, &down_bw);
1412                 if (ret)
1413                         return ret;
1414
1415                 tb_tunnel_dbg(tunnel, "consumed bandwidth %d/%d Mb/s\n", up_bw,
1416                               down_bw);
1417         }
1418
1419 out:
1420         if (consumed_up)
1421                 *consumed_up = up_bw;
1422         if (consumed_down)
1423                 *consumed_down = down_bw;
1424
1425         return 0;
1426 }
1427
1428 /**
1429  * tb_tunnel_release_unused_bandwidth() - Release unused bandwidth
1430  * @tunnel: Tunnel whose unused bandwidth to release
1431  *
1432  * If tunnel supports dynamic bandwidth management (USB3 tunnels at the
1433  * moment) this function makes it to release all the unused bandwidth.
1434  *
1435  * Returns %0 in case of success and negative errno otherwise.
1436  */
1437 int tb_tunnel_release_unused_bandwidth(struct tb_tunnel *tunnel)
1438 {
1439         if (!tb_tunnel_is_active(tunnel))
1440                 return 0;
1441
1442         if (tunnel->release_unused_bandwidth) {
1443                 int ret;
1444
1445                 ret = tunnel->release_unused_bandwidth(tunnel);
1446                 if (ret)
1447                         return ret;
1448         }
1449
1450         return 0;
1451 }
1452
1453 /**
1454  * tb_tunnel_reclaim_available_bandwidth() - Reclaim available bandwidth
1455  * @tunnel: Tunnel reclaiming available bandwidth
1456  * @available_up: Available upstream bandwidth (in Mb/s)
1457  * @available_down: Available downstream bandwidth (in Mb/s)
1458  *
1459  * Reclaims bandwidth from @available_up and @available_down and updates
1460  * the variables accordingly (e.g decreases both according to what was
1461  * reclaimed by the tunnel). If nothing was reclaimed the values are
1462  * kept as is.
1463  */
1464 void tb_tunnel_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
1465                                            int *available_up,
1466                                            int *available_down)
1467 {
1468         if (!tb_tunnel_is_active(tunnel))
1469                 return;
1470
1471         if (tunnel->reclaim_available_bandwidth)
1472                 tunnel->reclaim_available_bandwidth(tunnel, available_up,
1473                                                     available_down);
1474 }