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 /* Minimum number of credits needed for PCIe path */
  38 #define TB_MIN_PCIE_CREDITS             6U
  39 /*
  40  * Number of credits we try to allocate for each DMA path if not limited
  41  * by the host router baMaxHI.
  42  */
  43 #define TB_DMA_CREDITS                  14U
  44 /* Minimum number of credits for DMA path */
  45 #define TB_MIN_DMA_CREDITS              1U
  46
  47 static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA", "USB3" };
  48
  49 #define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...)                   \
  50         do {                                                            \
  51                 struct tb_tunnel *__tunnel = (tunnel);                  \
  52                 level(__tunnel->tb, "%llx:%x <-> %llx:%x (%s): " fmt,   \
  53                       tb_route(__tunnel->src_port->sw),                 \
  54                       __tunnel->src_port->port,                         \
  55                       tb_route(__tunnel->dst_port->sw),                 \
  56                       __tunnel->dst_port->port,                         \
  57                       tb_tunnel_names[__tunnel->type],                  \
  58                       ## arg);                                          \
  59         } while (0)
  60
  61 #define tb_tunnel_WARN(tunnel, fmt, arg...) \
  62         __TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
  63 #define tb_tunnel_warn(tunnel, fmt, arg...) \
  64         __TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
  65 #define tb_tunnel_info(tunnel, fmt, arg...) \
  66         __TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
  67 #define tb_tunnel_dbg(tunnel, fmt, arg...) \
  68         __TB_TUNNEL_PRINT(tb_dbg, tunnel, fmt, ##arg)
  69
  70 static inline unsigned int tb_usable_credits(const struct tb_port *port)
  71 {
  72         return port->total_credits - port->ctl_credits;
  73 }
  74
  75 /**
  76  * tb_available_credits() - Available credits for PCIe and DMA
  77  * @port: Lane adapter to check
  78  * @max_dp_streams: If non-%NULL stores maximum number of simultaneous DP
  79  *                  streams possible through this lane adapter
  80  */
  81 static unsigned int tb_available_credits(const struct tb_port *port,
  82                                          size_t *max_dp_streams)
  83 {
  84         const struct tb_switch *sw = port->sw;
  85         int credits, usb3, pcie, spare;
  86         size_t ndp;
  87
  88         usb3 = tb_acpi_may_tunnel_usb3() ? sw->max_usb3_credits : 0;
  89         pcie = tb_acpi_may_tunnel_pcie() ? sw->max_pcie_credits : 0;
  90
  91         if (tb_acpi_is_xdomain_allowed()) {
  92                 spare = min_not_zero(sw->max_dma_credits, TB_DMA_CREDITS);
  93                 /* Add some credits for potential second DMA tunnel */
  94                 spare += TB_MIN_DMA_CREDITS;
  95         } else {
  96                 spare = 0;
  97         }
  98
  99         credits = tb_usable_credits(port);
 100         if (tb_acpi_may_tunnel_dp()) {
 101                 /*
 102                  * Maximum number of DP streams possible through the
 103                  * lane adapter.
 104                  */
 105                 if (sw->min_dp_aux_credits + sw->min_dp_main_credits)
 106                         ndp = (credits - (usb3 + pcie + spare)) /
 107                               (sw->min_dp_aux_credits + sw->min_dp_main_credits);
 108                 else
 109                         ndp = 0;
 110         } else {
 111                 ndp = 0;
 112         }
 113         credits -= ndp * (sw->min_dp_aux_credits + sw->min_dp_main_credits);
 114         credits -= usb3;
 115
 116         if (max_dp_streams)
 117                 *max_dp_streams = ndp;
 118
 119         return credits > 0 ? credits : 0;
 120 }
 121
 122 static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
 123                                          enum tb_tunnel_type type)
 124 {
 125         struct tb_tunnel *tunnel;
 126
 127         tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
 128         if (!tunnel)
 129                 return NULL;
 130
 131         tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL);
 132         if (!tunnel->paths) {
 133                 tb_tunnel_free(tunnel);
 134                 return NULL;
 135         }
 136
 137         INIT_LIST_HEAD(&tunnel->list);
 138         tunnel->tb = tb;
 139         tunnel->npaths = npaths;
 140         tunnel->type = type;
 141
 142         return tunnel;
 143 }
 144
 145 static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)
 146 {
 147         int res;
 148
 149         res = tb_pci_port_enable(tunnel->src_port, activate);
 150         if (res)
 151                 return res;
 152
 153         if (tb_port_is_pcie_up(tunnel->dst_port))
 154                 return tb_pci_port_enable(tunnel->dst_port, activate);
 155
 156         return 0;
 157 }
 158
 159 static int tb_pci_init_credits(struct tb_path_hop *hop)
 160 {
 161         struct tb_port *port = hop->in_port;
 162         struct tb_switch *sw = port->sw;
 163         unsigned int credits;
 164
 165         if (tb_port_use_credit_allocation(port)) {
 166                 unsigned int available;
 167
 168                 available = tb_available_credits(port, NULL);
 169                 credits = min(sw->max_pcie_credits, available);
 170
 171                 if (credits < TB_MIN_PCIE_CREDITS)
 172                         return -ENOSPC;
 173
 174                 credits = max(TB_MIN_PCIE_CREDITS, credits);
 175         } else {
 176                 if (tb_port_is_null(port))
 177                         credits = port->bonded ? 32 : 16;
 178                 else
 179                         credits = 7;
 180         }
 181
 182         hop->initial_credits = credits;
 183         return 0;
 184 }
 185
 186 static int tb_pci_init_path(struct tb_path *path)
 187 {
 188         struct tb_path_hop *hop;
 189
 190         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
 191         path->egress_shared_buffer = TB_PATH_NONE;
 192         path->ingress_fc_enable = TB_PATH_ALL;
 193         path->ingress_shared_buffer = TB_PATH_NONE;
 194         path->priority = 3;
 195         path->weight = 1;
 196         path->drop_packages = 0;
 197
 198         tb_path_for_each_hop(path, hop) {
 199                 int ret;
 200
 201                 ret = tb_pci_init_credits(hop);
 202                 if (ret)
 203                         return ret;
 204         }
 205
 206         return 0;
 207 }
 208
 209 /**
 210  * tb_tunnel_discover_pci() - Discover existing PCIe tunnels
 211  * @tb: Pointer to the domain structure
 212  * @down: PCIe downstream adapter
 213  * @alloc_hopid: Allocate HopIDs from visited ports
 214  *
 215  * If @down adapter is active, follows the tunnel to the PCIe upstream
 216  * adapter and back. Returns the discovered tunnel or %NULL if there was
 217  * no tunnel.
 218  */
 219 struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down,
 220                                          bool alloc_hopid)
 221 {
 222         struct tb_tunnel *tunnel;
 223         struct tb_path *path;
 224
 225         if (!tb_pci_port_is_enabled(down))
 226                 return NULL;
 227
 228         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
 229         if (!tunnel)
 230                 return NULL;
 231
 232         tunnel->activate = tb_pci_activate;
 233         tunnel->src_port = down;
 234
 235         /*
 236          * Discover both paths even if they are not complete. We will
 237          * clean them up by calling tb_tunnel_deactivate() below in that
 238          * case.
 239          */
 240         path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1,
 241                                 &tunnel->dst_port, "PCIe Up", alloc_hopid);
 242         if (!path) {
 243                 /* Just disable the downstream port */
 244                 tb_pci_port_enable(down, false);
 245                 goto err_free;
 246         }
 247         tunnel->paths[TB_PCI_PATH_UP] = path;
 248         if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]))
 249                 goto err_free;
 250
 251         path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL,
 252                                 "PCIe Down", alloc_hopid);
 253         if (!path)
 254                 goto err_deactivate;
 255         tunnel->paths[TB_PCI_PATH_DOWN] = path;
 256         if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]))
 257                 goto err_deactivate;
 258
 259         /* Validate that the tunnel is complete */
 260         if (!tb_port_is_pcie_up(tunnel->dst_port)) {
 261                 tb_port_warn(tunnel->dst_port,
 262                              "path does not end on a PCIe adapter, cleaning up\n");
 263                 goto err_deactivate;
 264         }
 265
 266         if (down != tunnel->src_port) {
 267                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
 268                 goto err_deactivate;
 269         }
 270
 271         if (!tb_pci_port_is_enabled(tunnel->dst_port)) {
 272                 tb_tunnel_warn(tunnel,
 273                                "tunnel is not fully activated, cleaning up\n");
 274                 goto err_deactivate;
 275         }
 276
 277         tb_tunnel_dbg(tunnel, "discovered\n");
 278         return tunnel;
 279
 280 err_deactivate:
 281         tb_tunnel_deactivate(tunnel);
 282 err_free:
 283         tb_tunnel_free(tunnel);
 284
 285         return NULL;
 286 }
 287
 288 /**
 289  * tb_tunnel_alloc_pci() - allocate a pci tunnel
 290  * @tb: Pointer to the domain structure
 291  * @up: PCIe upstream adapter port
 292  * @down: PCIe downstream adapter port
 293  *
 294  * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
 295  * TB_TYPE_PCIE_DOWN.
 296  *
 297  * Return: Returns a tb_tunnel on success or NULL on failure.
 298  */
 299 struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
 300                                       struct tb_port *down)
 301 {
 302         struct tb_tunnel *tunnel;
 303         struct tb_path *path;
 304
 305         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
 306         if (!tunnel)
 307                 return NULL;
 308
 309         tunnel->activate = tb_pci_activate;
 310         tunnel->src_port = down;
 311         tunnel->dst_port = up;
 312
 313         path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0,
 314                              "PCIe Down");
 315         if (!path)
 316                 goto err_free;
 317         tunnel->paths[TB_PCI_PATH_DOWN] = path;
 318         if (tb_pci_init_path(path))
 319                 goto err_free;
 320
 321         path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0,
 322                              "PCIe Up");
 323         if (!path)
 324                 goto err_free;
 325         tunnel->paths[TB_PCI_PATH_UP] = path;
 326         if (tb_pci_init_path(path))
 327                 goto err_free;
 328
 329         return tunnel;
 330
 331 err_free:
 332         tb_tunnel_free(tunnel);
 333         return NULL;
 334 }
 335
 336 static bool tb_dp_is_usb4(const struct tb_switch *sw)
 337 {
 338         /* Titan Ridge DP adapters need the same treatment as USB4 */
 339         return tb_switch_is_usb4(sw) || tb_switch_is_titan_ridge(sw);
 340 }
 341
 342 static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out)
 343 {
 344         int timeout = 10;
 345         u32 val;
 346         int ret;
 347
 348         /* Both ends need to support this */
 349         if (!tb_dp_is_usb4(in->sw) || !tb_dp_is_usb4(out->sw))
 350                 return 0;
 351
 352         ret = tb_port_read(out, &val, TB_CFG_PORT,
 353                            out->cap_adap + DP_STATUS_CTRL, 1);
 354         if (ret)
 355                 return ret;
 356
 357         val |= DP_STATUS_CTRL_UF | DP_STATUS_CTRL_CMHS;
 358
 359         ret = tb_port_write(out, &val, TB_CFG_PORT,
 360                             out->cap_adap + DP_STATUS_CTRL, 1);
 361         if (ret)
 362                 return ret;
 363
 364         do {
 365                 ret = tb_port_read(out, &val, TB_CFG_PORT,
 366                                    out->cap_adap + DP_STATUS_CTRL, 1);
 367                 if (ret)
 368                         return ret;
 369                 if (!(val & DP_STATUS_CTRL_CMHS))
 370                         return 0;
 371                 usleep_range(10, 100);
 372         } while (timeout--);
 373
 374         return -ETIMEDOUT;
 375 }
 376
 377 static inline u32 tb_dp_cap_get_rate(u32 val)
 378 {
 379         u32 rate = (val & DP_COMMON_CAP_RATE_MASK) >> DP_COMMON_CAP_RATE_SHIFT;
 380
 381         switch (rate) {
 382         case DP_COMMON_CAP_RATE_RBR:
 383                 return 1620;
 384         case DP_COMMON_CAP_RATE_HBR:
 385                 return 2700;
 386         case DP_COMMON_CAP_RATE_HBR2:
 387                 return 5400;
 388         case DP_COMMON_CAP_RATE_HBR3:
 389                 return 8100;
 390         default:
 391                 return 0;
 392         }
 393 }
 394
 395 static inline u32 tb_dp_cap_set_rate(u32 val, u32 rate)
 396 {
 397         val &= ~DP_COMMON_CAP_RATE_MASK;
 398         switch (rate) {
 399         default:
 400                 WARN(1, "invalid rate %u passed, defaulting to 1620 MB/s\n", rate);
 401                 fallthrough;
 402         case 1620:
 403                 val |= DP_COMMON_CAP_RATE_RBR << DP_COMMON_CAP_RATE_SHIFT;
 404                 break;
 405         case 2700:
 406                 val |= DP_COMMON_CAP_RATE_HBR << DP_COMMON_CAP_RATE_SHIFT;
 407                 break;
 408         case 5400:
 409                 val |= DP_COMMON_CAP_RATE_HBR2 << DP_COMMON_CAP_RATE_SHIFT;
 410                 break;
 411         case 8100:
 412                 val |= DP_COMMON_CAP_RATE_HBR3 << DP_COMMON_CAP_RATE_SHIFT;
 413                 break;
 414         }
 415         return val;
 416 }
 417
 418 static inline u32 tb_dp_cap_get_lanes(u32 val)
 419 {
 420         u32 lanes = (val & DP_COMMON_CAP_LANES_MASK) >> DP_COMMON_CAP_LANES_SHIFT;
 421
 422         switch (lanes) {
 423         case DP_COMMON_CAP_1_LANE:
 424                 return 1;
 425         case DP_COMMON_CAP_2_LANES:
 426                 return 2;
 427         case DP_COMMON_CAP_4_LANES:
 428                 return 4;
 429         default:
 430                 return 0;
 431         }
 432 }
 433
 434 static inline u32 tb_dp_cap_set_lanes(u32 val, u32 lanes)
 435 {
 436         val &= ~DP_COMMON_CAP_LANES_MASK;
 437         switch (lanes) {
 438         default:
 439                 WARN(1, "invalid number of lanes %u passed, defaulting to 1\n",
 440                      lanes);
 441                 fallthrough;
 442         case 1:
 443                 val |= DP_COMMON_CAP_1_LANE << DP_COMMON_CAP_LANES_SHIFT;
 444                 break;
 445         case 2:
 446                 val |= DP_COMMON_CAP_2_LANES << DP_COMMON_CAP_LANES_SHIFT;
 447                 break;
 448         case 4:
 449                 val |= DP_COMMON_CAP_4_LANES << DP_COMMON_CAP_LANES_SHIFT;
 450                 break;
 451         }
 452         return val;
 453 }
 454
 455 static unsigned int tb_dp_bandwidth(unsigned int rate, unsigned int lanes)
 456 {
 457         /* Tunneling removes the DP 8b/10b encoding */
 458         return rate * lanes * 8 / 10;
 459 }
 460
 461 static int tb_dp_reduce_bandwidth(int max_bw, u32 in_rate, u32 in_lanes,
 462                                   u32 out_rate, u32 out_lanes, u32 *new_rate,
 463                                   u32 *new_lanes)
 464 {
 465         static const u32 dp_bw[][2] = {
 466                 /* Mb/s, lanes */
 467                 { 8100, 4 }, /* 25920 Mb/s */
 468                 { 5400, 4 }, /* 17280 Mb/s */
 469                 { 8100, 2 }, /* 12960 Mb/s */
 470                 { 2700, 4 }, /* 8640 Mb/s */
 471                 { 5400, 2 }, /* 8640 Mb/s */
 472                 { 8100, 1 }, /* 6480 Mb/s */
 473                 { 1620, 4 }, /* 5184 Mb/s */
 474                 { 5400, 1 }, /* 4320 Mb/s */
 475                 { 2700, 2 }, /* 4320 Mb/s */
 476                 { 1620, 2 }, /* 2592 Mb/s */
 477                 { 2700, 1 }, /* 2160 Mb/s */
 478                 { 1620, 1 }, /* 1296 Mb/s */
 479         };
 480         unsigned int i;
 481
 482         /*
 483          * Find a combination that can fit into max_bw and does not
 484          * exceed the maximum rate and lanes supported by the DP OUT and
 485          * DP IN adapters.
 486          */
 487         for (i = 0; i < ARRAY_SIZE(dp_bw); i++) {
 488                 if (dp_bw[i][0] > out_rate || dp_bw[i][1] > out_lanes)
 489                         continue;
 490
 491                 if (dp_bw[i][0] > in_rate || dp_bw[i][1] > in_lanes)
 492                         continue;
 493
 494                 if (tb_dp_bandwidth(dp_bw[i][0], dp_bw[i][1]) <= max_bw) {
 495                         *new_rate = dp_bw[i][0];
 496                         *new_lanes = dp_bw[i][1];
 497                         return 0;
 498                 }
 499         }
 500
 501         return -ENOSR;
 502 }
 503
 504 static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
 505 {
 506         u32 out_dp_cap, out_rate, out_lanes, in_dp_cap, in_rate, in_lanes, bw;
 507         struct tb_port *out = tunnel->dst_port;
 508         struct tb_port *in = tunnel->src_port;
 509         int ret, max_bw;
 510
 511         /*
 512          * Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for
 513          * newer generation hardware.
 514          */
 515         if (in->sw->generation < 2 || out->sw->generation < 2)
 516                 return 0;
 517
 518         /*
 519          * Perform connection manager handshake between IN and OUT ports
 520          * before capabilities exchange can take place.
 521          */
 522         ret = tb_dp_cm_handshake(in, out);
 523         if (ret)
 524                 return ret;
 525
 526         /* Read both DP_LOCAL_CAP registers */
 527         ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
 528                            in->cap_adap + DP_LOCAL_CAP, 1);
 529         if (ret)
 530                 return ret;
 531
 532         ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
 533                            out->cap_adap + DP_LOCAL_CAP, 1);
 534         if (ret)
 535                 return ret;
 536
 537         /* Write IN local caps to OUT remote caps */
 538         ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT,
 539                             out->cap_adap + DP_REMOTE_CAP, 1);
 540         if (ret)
 541                 return ret;
 542
 543         in_rate = tb_dp_cap_get_rate(in_dp_cap);
 544         in_lanes = tb_dp_cap_get_lanes(in_dp_cap);
 545         tb_port_dbg(in, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
 546                     in_rate, in_lanes, tb_dp_bandwidth(in_rate, in_lanes));
 547
 548         /*
 549          * If the tunnel bandwidth is limited (max_bw is set) then see
 550          * if we need to reduce bandwidth to fit there.
 551          */
 552         out_rate = tb_dp_cap_get_rate(out_dp_cap);
 553         out_lanes = tb_dp_cap_get_lanes(out_dp_cap);
 554         bw = tb_dp_bandwidth(out_rate, out_lanes);
 555         tb_port_dbg(out, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
 556                     out_rate, out_lanes, bw);
 557
 558         if (in->sw->config.depth < out->sw->config.depth)
 559                 max_bw = tunnel->max_down;
 560         else
 561                 max_bw = tunnel->max_up;
 562
 563         if (max_bw && bw > max_bw) {
 564                 u32 new_rate, new_lanes, new_bw;
 565
 566                 ret = tb_dp_reduce_bandwidth(max_bw, in_rate, in_lanes,
 567                                              out_rate, out_lanes, &new_rate,
 568                                              &new_lanes);
 569                 if (ret) {
 570                         tb_port_info(out, "not enough bandwidth for DP tunnel\n");
 571                         return ret;
 572                 }
 573
 574                 new_bw = tb_dp_bandwidth(new_rate, new_lanes);
 575                 tb_port_dbg(out, "bandwidth reduced to %u Mb/s x%u = %u Mb/s\n",
 576                             new_rate, new_lanes, new_bw);
 577
 578                 /*
 579                  * Set new rate and number of lanes before writing it to
 580                  * the IN port remote caps.
 581                  */
 582                 out_dp_cap = tb_dp_cap_set_rate(out_dp_cap, new_rate);
 583                 out_dp_cap = tb_dp_cap_set_lanes(out_dp_cap, new_lanes);
 584         }
 585
 586         /*
 587          * Titan Ridge does not disable AUX timers when it gets
 588          * SET_CONFIG with SET_LTTPR_MODE set. This causes problems with
 589          * DP tunneling.
 590          */
 591         if (tb_route(out->sw) && tb_switch_is_titan_ridge(out->sw)) {
 592                 out_dp_cap |= DP_COMMON_CAP_LTTPR_NS;
 593                 tb_port_dbg(out, "disabling LTTPR\n");
 594         }
 595
 596         return tb_port_write(in, &out_dp_cap, TB_CFG_PORT,
 597                              in->cap_adap + DP_REMOTE_CAP, 1);
 598 }
 599
 600 static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
 601 {
 602         int ret;
 603
 604         if (active) {
 605                 struct tb_path **paths;
 606                 int last;
 607
 608                 paths = tunnel->paths;
 609                 last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;
 610
 611                 tb_dp_port_set_hops(tunnel->src_port,
 612                         paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,
 613                         paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,
 614                         paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);
 615
 616                 tb_dp_port_set_hops(tunnel->dst_port,
 617                         paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,
 618                         paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,
 619                         paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);
 620         } else {
 621                 tb_dp_port_hpd_clear(tunnel->src_port);
 622                 tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0);
 623                 if (tb_port_is_dpout(tunnel->dst_port))
 624                         tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0);
 625         }
 626
 627         ret = tb_dp_port_enable(tunnel->src_port, active);
 628         if (ret)
 629                 return ret;
 630
 631         if (tb_port_is_dpout(tunnel->dst_port))
 632                 return tb_dp_port_enable(tunnel->dst_port, active);
 633
 634         return 0;
 635 }
 636
 637 static int tb_dp_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
 638                                     int *consumed_down)
 639 {
 640         struct tb_port *in = tunnel->src_port;
 641         const struct tb_switch *sw = in->sw;
 642         u32 val, rate = 0, lanes = 0;
 643         int ret;
 644
 645         if (tb_dp_is_usb4(sw)) {
 646                 int timeout = 20;
 647
 648                 /*
 649                  * Wait for DPRX done. Normally it should be already set
 650                  * for active tunnel.
 651                  */
 652                 do {
 653                         ret = tb_port_read(in, &val, TB_CFG_PORT,
 654                                            in->cap_adap + DP_COMMON_CAP, 1);
 655                         if (ret)
 656                                 return ret;
 657
 658                         if (val & DP_COMMON_CAP_DPRX_DONE) {
 659                                 rate = tb_dp_cap_get_rate(val);
 660                                 lanes = tb_dp_cap_get_lanes(val);
 661                                 break;
 662                         }
 663                         msleep(250);
 664                 } while (timeout--);
 665
 666                 if (!timeout)
 667                         return -ETIMEDOUT;
 668         } else if (sw->generation >= 2) {
 669                 /*
 670                  * Read from the copied remote cap so that we take into
 671                  * account if capabilities were reduced during exchange.
 672                  */
 673                 ret = tb_port_read(in, &val, TB_CFG_PORT,
 674                                    in->cap_adap + DP_REMOTE_CAP, 1);
 675                 if (ret)
 676                         return ret;
 677
 678                 rate = tb_dp_cap_get_rate(val);
 679                 lanes = tb_dp_cap_get_lanes(val);
 680         } else {
 681                 /* No bandwidth management for legacy devices  */
 682                 *consumed_up = 0;
 683                 *consumed_down = 0;
 684                 return 0;
 685         }
 686
 687         if (in->sw->config.depth < tunnel->dst_port->sw->config.depth) {
 688                 *consumed_up = 0;
 689                 *consumed_down = tb_dp_bandwidth(rate, lanes);
 690         } else {
 691                 *consumed_up = tb_dp_bandwidth(rate, lanes);
 692                 *consumed_down = 0;
 693         }
 694
 695         return 0;
 696 }
 697
 698 static void tb_dp_init_aux_credits(struct tb_path_hop *hop)
 699 {
 700         struct tb_port *port = hop->in_port;
 701         struct tb_switch *sw = port->sw;
 702
 703         if (tb_port_use_credit_allocation(port))
 704                 hop->initial_credits = sw->min_dp_aux_credits;
 705         else
 706                 hop->initial_credits = 1;
 707 }
 708
 709 static void tb_dp_init_aux_path(struct tb_path *path)
 710 {
 711         struct tb_path_hop *hop;
 712
 713         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
 714         path->egress_shared_buffer = TB_PATH_NONE;
 715         path->ingress_fc_enable = TB_PATH_ALL;
 716         path->ingress_shared_buffer = TB_PATH_NONE;
 717         path->priority = 2;
 718         path->weight = 1;
 719
 720         tb_path_for_each_hop(path, hop)
 721                 tb_dp_init_aux_credits(hop);
 722 }
 723
 724 static int tb_dp_init_video_credits(struct tb_path_hop *hop)
 725 {
 726         struct tb_port *port = hop->in_port;
 727         struct tb_switch *sw = port->sw;
 728
 729         if (tb_port_use_credit_allocation(port)) {
 730                 unsigned int nfc_credits;
 731                 size_t max_dp_streams;
 732
 733                 tb_available_credits(port, &max_dp_streams);
 734                 /*
 735                  * Read the number of currently allocated NFC credits
 736                  * from the lane adapter. Since we only use them for DP
 737                  * tunneling we can use that to figure out how many DP
 738                  * tunnels already go through the lane adapter.
 739                  */
 740                 nfc_credits = port->config.nfc_credits &
 741                                 ADP_CS_4_NFC_BUFFERS_MASK;
 742                 if (nfc_credits / sw->min_dp_main_credits > max_dp_streams)
 743                         return -ENOSPC;
 744
 745                 hop->nfc_credits = sw->min_dp_main_credits;
 746         } else {
 747                 hop->nfc_credits = min(port->total_credits - 2, 12U);
 748         }
 749
 750         return 0;
 751 }
 752
 753 static int tb_dp_init_video_path(struct tb_path *path)
 754 {
 755         struct tb_path_hop *hop;
 756
 757         path->egress_fc_enable = TB_PATH_NONE;
 758         path->egress_shared_buffer = TB_PATH_NONE;
 759         path->ingress_fc_enable = TB_PATH_NONE;
 760         path->ingress_shared_buffer = TB_PATH_NONE;
 761         path->priority = 1;
 762         path->weight = 1;
 763
 764         tb_path_for_each_hop(path, hop) {
 765                 int ret;
 766
 767                 ret = tb_dp_init_video_credits(hop);
 768                 if (ret)
 769                         return ret;
 770         }
 771
 772         return 0;
 773 }
 774
 775 /**
 776  * tb_tunnel_discover_dp() - Discover existing Display Port tunnels
 777  * @tb: Pointer to the domain structure
 778  * @in: DP in adapter
 779  * @alloc_hopid: Allocate HopIDs from visited ports
 780  *
 781  * If @in adapter is active, follows the tunnel to the DP out adapter
 782  * and back. Returns the discovered tunnel or %NULL if there was no
 783  * tunnel.
 784  *
 785  * Return: DP tunnel or %NULL if no tunnel found.
 786  */
 787 struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in,
 788                                         bool alloc_hopid)
 789 {
 790         struct tb_tunnel *tunnel;
 791         struct tb_port *port;
 792         struct tb_path *path;
 793
 794         if (!tb_dp_port_is_enabled(in))
 795                 return NULL;
 796
 797         tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
 798         if (!tunnel)
 799                 return NULL;
 800
 801         tunnel->init = tb_dp_xchg_caps;
 802         tunnel->activate = tb_dp_activate;
 803         tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
 804         tunnel->src_port = in;
 805
 806         path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1,
 807                                 &tunnel->dst_port, "Video", alloc_hopid);
 808         if (!path) {
 809                 /* Just disable the DP IN port */
 810                 tb_dp_port_enable(in, false);
 811                 goto err_free;
 812         }
 813         tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;
 814         if (tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT]))
 815                 goto err_free;
 816
 817         path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX",
 818                                 alloc_hopid);
 819         if (!path)
 820                 goto err_deactivate;
 821         tunnel->paths[TB_DP_AUX_PATH_OUT] = path;
 822         tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT]);
 823
 824         path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID,
 825                                 &port, "AUX RX", alloc_hopid);
 826         if (!path)
 827                 goto err_deactivate;
 828         tunnel->paths[TB_DP_AUX_PATH_IN] = path;
 829         tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN]);
 830
 831         /* Validate that the tunnel is complete */
 832         if (!tb_port_is_dpout(tunnel->dst_port)) {
 833                 tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");
 834                 goto err_deactivate;
 835         }
 836
 837         if (!tb_dp_port_is_enabled(tunnel->dst_port))
 838                 goto err_deactivate;
 839
 840         if (!tb_dp_port_hpd_is_active(tunnel->dst_port))
 841                 goto err_deactivate;
 842
 843         if (port != tunnel->src_port) {
 844                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
 845                 goto err_deactivate;
 846         }
 847
 848         tb_tunnel_dbg(tunnel, "discovered\n");
 849         return tunnel;
 850
 851 err_deactivate:
 852         tb_tunnel_deactivate(tunnel);
 853 err_free:
 854         tb_tunnel_free(tunnel);
 855
 856         return NULL;
 857 }
 858
 859 /**
 860  * tb_tunnel_alloc_dp() - allocate a Display Port tunnel
 861  * @tb: Pointer to the domain structure
 862  * @in: DP in adapter port
 863  * @out: DP out adapter port
 864  * @link_nr: Preferred lane adapter when the link is not bonded
 865  * @max_up: Maximum available upstream bandwidth for the DP tunnel (%0
 866  *          if not limited)
 867  * @max_down: Maximum available downstream bandwidth for the DP tunnel
 868  *            (%0 if not limited)
 869  *
 870  * Allocates a tunnel between @in and @out that is capable of tunneling
 871  * Display Port traffic.
 872  *
 873  * Return: Returns a tb_tunnel on success or NULL on failure.
 874  */
 875 struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
 876                                      struct tb_port *out, int link_nr,
 877                                      int max_up, int max_down)
 878 {
 879         struct tb_tunnel *tunnel;
 880         struct tb_path **paths;
 881         struct tb_path *path;
 882
 883         if (WARN_ON(!in->cap_adap || !out->cap_adap))
 884                 return NULL;
 885
 886         tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
 887         if (!tunnel)
 888                 return NULL;
 889
 890         tunnel->init = tb_dp_xchg_caps;
 891         tunnel->activate = tb_dp_activate;
 892         tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
 893         tunnel->src_port = in;
 894         tunnel->dst_port = out;
 895         tunnel->max_up = max_up;
 896         tunnel->max_down = max_down;
 897
 898         paths = tunnel->paths;
 899
 900         path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,
 901                              link_nr, "Video");
 902         if (!path)
 903                 goto err_free;
 904         tb_dp_init_video_path(path);
 905         paths[TB_DP_VIDEO_PATH_OUT] = path;
 906
 907         path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
 908                              TB_DP_AUX_TX_HOPID, link_nr, "AUX TX");
 909         if (!path)
 910                 goto err_free;
 911         tb_dp_init_aux_path(path);
 912         paths[TB_DP_AUX_PATH_OUT] = path;
 913
 914         path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,
 915                              TB_DP_AUX_RX_HOPID, link_nr, "AUX RX");
 916         if (!path)
 917                 goto err_free;
 918         tb_dp_init_aux_path(path);
 919         paths[TB_DP_AUX_PATH_IN] = path;
 920
 921         return tunnel;
 922
 923 err_free:
 924         tb_tunnel_free(tunnel);
 925         return NULL;
 926 }
 927
 928 static unsigned int tb_dma_available_credits(const struct tb_port *port)
 929 {
 930         const struct tb_switch *sw = port->sw;
 931         int credits;
 932
 933         credits = tb_available_credits(port, NULL);
 934         if (tb_acpi_may_tunnel_pcie())
 935                 credits -= sw->max_pcie_credits;
 936         credits -= port->dma_credits;
 937
 938         return credits > 0 ? credits : 0;
 939 }
 940
 941 static int tb_dma_reserve_credits(struct tb_path_hop *hop, unsigned int credits)
 942 {
 943         struct tb_port *port = hop->in_port;
 944
 945         if (tb_port_use_credit_allocation(port)) {
 946                 unsigned int available = tb_dma_available_credits(port);
 947
 948                 /*
 949                  * Need to have at least TB_MIN_DMA_CREDITS, otherwise
 950                  * DMA path cannot be established.
 951                  */
 952                 if (available < TB_MIN_DMA_CREDITS)
 953                         return -ENOSPC;
 954
 955                 while (credits > available)
 956                         credits--;
 957
 958                 tb_port_dbg(port, "reserving %u credits for DMA path\n",
 959                             credits);
 960
 961                 port->dma_credits += credits;
 962         } else {
 963                 if (tb_port_is_null(port))
 964                         credits = port->bonded ? 14 : 6;
 965                 else
 966                         credits = min(port->total_credits, credits);
 967         }
 968
 969         hop->initial_credits = credits;
 970         return 0;
 971 }
 972
 973 /* Path from lane adapter to NHI */
 974 static int tb_dma_init_rx_path(struct tb_path *path, unsigned int credits)
 975 {
 976         struct tb_path_hop *hop;
 977         unsigned int i, tmp;
 978
 979         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
 980         path->ingress_fc_enable = TB_PATH_ALL;
 981         path->egress_shared_buffer = TB_PATH_NONE;
 982         path->ingress_shared_buffer = TB_PATH_NONE;
 983         path->priority = 5;
 984         path->weight = 1;
 985         path->clear_fc = true;
 986
 987         /*
 988          * First lane adapter is the one connected to the remote host.
 989          * We don't tunnel other traffic over this link so can use all
 990          * the credits (except the ones reserved for control traffic).
 991          */
 992         hop = &path->hops[0];
 993         tmp = min(tb_usable_credits(hop->in_port), credits);
 994         hop->initial_credits = tmp;
 995         hop->in_port->dma_credits += tmp;
 996
 997         for (i = 1; i < path->path_length; i++) {
 998                 int ret;
 999
1000                 ret = tb_dma_reserve_credits(&path->hops[i], credits);
1001                 if (ret)
1002                         return ret;
1003         }
1004
1005         return 0;
1006 }
1007
1008 /* Path from NHI to lane adapter */
1009 static int tb_dma_init_tx_path(struct tb_path *path, unsigned int credits)
1010 {
1011         struct tb_path_hop *hop;
1012
1013         path->egress_fc_enable = TB_PATH_ALL;
1014         path->ingress_fc_enable = TB_PATH_ALL;
1015         path->egress_shared_buffer = TB_PATH_NONE;
1016         path->ingress_shared_buffer = TB_PATH_NONE;
1017         path->priority = 5;
1018         path->weight = 1;
1019         path->clear_fc = true;
1020
1021         tb_path_for_each_hop(path, hop) {
1022                 int ret;
1023
1024                 ret = tb_dma_reserve_credits(hop, credits);
1025                 if (ret)
1026                         return ret;
1027         }
1028
1029         return 0;
1030 }
1031
1032 static void tb_dma_release_credits(struct tb_path_hop *hop)
1033 {
1034         struct tb_port *port = hop->in_port;
1035
1036         if (tb_port_use_credit_allocation(port)) {
1037                 port->dma_credits -= hop->initial_credits;
1038
1039                 tb_port_dbg(port, "released %u DMA path credits\n",
1040                             hop->initial_credits);
1041         }
1042 }
1043
1044 static void tb_dma_deinit_path(struct tb_path *path)
1045 {
1046         struct tb_path_hop *hop;
1047
1048         tb_path_for_each_hop(path, hop)
1049                 tb_dma_release_credits(hop);
1050 }
1051
1052 static void tb_dma_deinit(struct tb_tunnel *tunnel)
1053 {
1054         int i;
1055
1056         for (i = 0; i < tunnel->npaths; i++) {
1057                 if (!tunnel->paths[i])
1058                         continue;
1059                 tb_dma_deinit_path(tunnel->paths[i]);
1060         }
1061 }
1062
1063 /**
1064  * tb_tunnel_alloc_dma() - allocate a DMA tunnel
1065  * @tb: Pointer to the domain structure
1066  * @nhi: Host controller port
1067  * @dst: Destination null port which the other domain is connected to
1068  * @transmit_path: HopID used for transmitting packets
1069  * @transmit_ring: NHI ring number used to send packets towards the
1070  *                 other domain. Set to %-1 if TX path is not needed.
1071  * @receive_path: HopID used for receiving packets
1072  * @receive_ring: NHI ring number used to receive packets from the
1073  *                other domain. Set to %-1 if RX path is not needed.
1074  *
1075  * Return: Returns a tb_tunnel on success or NULL on failure.
1076  */
1077 struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
1078                                       struct tb_port *dst, int transmit_path,
1079                                       int transmit_ring, int receive_path,
1080                                       int receive_ring)
1081 {
1082         struct tb_tunnel *tunnel;
1083         size_t npaths = 0, i = 0;
1084         struct tb_path *path;
1085         int credits;
1086
1087         if (receive_ring > 0)
1088                 npaths++;
1089         if (transmit_ring > 0)
1090                 npaths++;
1091
1092         if (WARN_ON(!npaths))
1093                 return NULL;
1094
1095         tunnel = tb_tunnel_alloc(tb, npaths, TB_TUNNEL_DMA);
1096         if (!tunnel)
1097                 return NULL;
1098
1099         tunnel->src_port = nhi;
1100         tunnel->dst_port = dst;
1101         tunnel->deinit = tb_dma_deinit;
1102
1103         credits = min_not_zero(TB_DMA_CREDITS, nhi->sw->max_dma_credits);
1104
1105         if (receive_ring > 0) {
1106                 path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0,
1107                                      "DMA RX");
1108                 if (!path)
1109                         goto err_free;
1110                 tunnel->paths[i++] = path;
1111                 if (tb_dma_init_rx_path(path, credits)) {
1112                         tb_tunnel_dbg(tunnel, "not enough buffers for RX path\n");
1113                         goto err_free;
1114                 }
1115         }
1116
1117         if (transmit_ring > 0) {
1118                 path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0,
1119                                      "DMA TX");
1120                 if (!path)
1121                         goto err_free;
1122                 tunnel->paths[i++] = path;
1123                 if (tb_dma_init_tx_path(path, credits)) {
1124                         tb_tunnel_dbg(tunnel, "not enough buffers for TX path\n");
1125                         goto err_free;
1126                 }
1127         }
1128
1129         return tunnel;
1130
1131 err_free:
1132         tb_tunnel_free(tunnel);
1133         return NULL;
1134 }
1135
1136 /**
1137  * tb_tunnel_match_dma() - Match DMA tunnel
1138  * @tunnel: Tunnel to match
1139  * @transmit_path: HopID used for transmitting packets. Pass %-1 to ignore.
1140  * @transmit_ring: NHI ring number used to send packets towards the
1141  *                 other domain. Pass %-1 to ignore.
1142  * @receive_path: HopID used for receiving packets. Pass %-1 to ignore.
1143  * @receive_ring: NHI ring number used to receive packets from the
1144  *                other domain. Pass %-1 to ignore.
1145  *
1146  * This function can be used to match specific DMA tunnel, if there are
1147  * multiple DMA tunnels going through the same XDomain connection.
1148  * Returns true if there is match and false otherwise.
1149  */
1150 bool tb_tunnel_match_dma(const struct tb_tunnel *tunnel, int transmit_path,
1151                          int transmit_ring, int receive_path, int receive_ring)
1152 {
1153         const struct tb_path *tx_path = NULL, *rx_path = NULL;
1154         int i;
1155
1156         if (!receive_ring || !transmit_ring)
1157                 return false;
1158
1159         for (i = 0; i < tunnel->npaths; i++) {
1160                 const struct tb_path *path = tunnel->paths[i];
1161
1162                 if (!path)
1163                         continue;
1164
1165                 if (tb_port_is_nhi(path->hops[0].in_port))
1166                         tx_path = path;
1167                 else if (tb_port_is_nhi(path->hops[path->path_length - 1].out_port))
1168                         rx_path = path;
1169         }
1170
1171         if (transmit_ring > 0 || transmit_path > 0) {
1172                 if (!tx_path)
1173                         return false;
1174                 if (transmit_ring > 0 &&
1175                     (tx_path->hops[0].in_hop_index != transmit_ring))
1176                         return false;
1177                 if (transmit_path > 0 &&
1178                     (tx_path->hops[tx_path->path_length - 1].next_hop_index != transmit_path))
1179                         return false;
1180         }
1181
1182         if (receive_ring > 0 || receive_path > 0) {
1183                 if (!rx_path)
1184                         return false;
1185                 if (receive_path > 0 &&
1186                     (rx_path->hops[0].in_hop_index != receive_path))
1187                         return false;
1188                 if (receive_ring > 0 &&
1189                     (rx_path->hops[rx_path->path_length - 1].next_hop_index != receive_ring))
1190                         return false;
1191         }
1192
1193         return true;
1194 }
1195
1196 static int tb_usb3_max_link_rate(struct tb_port *up, struct tb_port *down)
1197 {
1198         int ret, up_max_rate, down_max_rate;
1199
1200         ret = usb4_usb3_port_max_link_rate(up);
1201         if (ret < 0)
1202                 return ret;
1203         up_max_rate = ret;
1204
1205         ret = usb4_usb3_port_max_link_rate(down);
1206         if (ret < 0)
1207                 return ret;
1208         down_max_rate = ret;
1209
1210         return min(up_max_rate, down_max_rate);
1211 }
1212
1213 static int tb_usb3_init(struct tb_tunnel *tunnel)
1214 {
1215         tb_tunnel_dbg(tunnel, "allocating initial bandwidth %d/%d Mb/s\n",
1216                       tunnel->allocated_up, tunnel->allocated_down);
1217
1218         return usb4_usb3_port_allocate_bandwidth(tunnel->src_port,
1219                                                  &tunnel->allocated_up,
1220                                                  &tunnel->allocated_down);
1221 }
1222
1223 static int tb_usb3_activate(struct tb_tunnel *tunnel, bool activate)
1224 {
1225         int res;
1226
1227         res = tb_usb3_port_enable(tunnel->src_port, activate);
1228         if (res)
1229                 return res;
1230
1231         if (tb_port_is_usb3_up(tunnel->dst_port))
1232                 return tb_usb3_port_enable(tunnel->dst_port, activate);
1233
1234         return 0;
1235 }
1236
1237 static int tb_usb3_consumed_bandwidth(struct tb_tunnel *tunnel,
1238                 int *consumed_up, int *consumed_down)
1239 {
1240         int pcie_enabled = tb_acpi_may_tunnel_pcie();
1241
1242         /*
1243          * PCIe tunneling, if enabled, affects the USB3 bandwidth so
1244          * take that it into account here.
1245          */
1246         *consumed_up = tunnel->allocated_up * (3 + pcie_enabled) / 3;
1247         *consumed_down = tunnel->allocated_down * (3 + pcie_enabled) / 3;
1248         return 0;
1249 }
1250
1251 static int tb_usb3_release_unused_bandwidth(struct tb_tunnel *tunnel)
1252 {
1253         int ret;
1254
1255         ret = usb4_usb3_port_release_bandwidth(tunnel->src_port,
1256                                                &tunnel->allocated_up,
1257                                                &tunnel->allocated_down);
1258         if (ret)
1259                 return ret;
1260
1261         tb_tunnel_dbg(tunnel, "decreased bandwidth allocation to %d/%d Mb/s\n",
1262                       tunnel->allocated_up, tunnel->allocated_down);
1263         return 0;
1264 }
1265
1266 static void tb_usb3_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
1267                                                 int *available_up,
1268                                                 int *available_down)
1269 {
1270         int ret, max_rate, allocate_up, allocate_down;
1271
1272         ret = usb4_usb3_port_actual_link_rate(tunnel->src_port);
1273         if (ret < 0) {
1274                 tb_tunnel_warn(tunnel, "failed to read actual link rate\n");
1275                 return;
1276         } else if (!ret) {
1277                 /* Use maximum link rate if the link valid is not set */
1278                 ret = usb4_usb3_port_max_link_rate(tunnel->src_port);
1279                 if (ret < 0) {
1280                         tb_tunnel_warn(tunnel, "failed to read maximum link rate\n");
1281                         return;
1282                 }
1283         }
1284
1285         /*
1286          * 90% of the max rate can be allocated for isochronous
1287          * transfers.
1288          */
1289         max_rate = ret * 90 / 100;
1290
1291         /* No need to reclaim if already at maximum */
1292         if (tunnel->allocated_up >= max_rate &&
1293             tunnel->allocated_down >= max_rate)
1294                 return;
1295
1296         /* Don't go lower than what is already allocated */
1297         allocate_up = min(max_rate, *available_up);
1298         if (allocate_up < tunnel->allocated_up)
1299                 allocate_up = tunnel->allocated_up;
1300
1301         allocate_down = min(max_rate, *available_down);
1302         if (allocate_down < tunnel->allocated_down)
1303                 allocate_down = tunnel->allocated_down;
1304
1305         /* If no changes no need to do more */
1306         if (allocate_up == tunnel->allocated_up &&
1307             allocate_down == tunnel->allocated_down)
1308                 return;
1309
1310         ret = usb4_usb3_port_allocate_bandwidth(tunnel->src_port, &allocate_up,
1311                                                 &allocate_down);
1312         if (ret) {
1313                 tb_tunnel_info(tunnel, "failed to allocate bandwidth\n");
1314                 return;
1315         }
1316
1317         tunnel->allocated_up = allocate_up;
1318         *available_up -= tunnel->allocated_up;
1319
1320         tunnel->allocated_down = allocate_down;
1321         *available_down -= tunnel->allocated_down;
1322
1323         tb_tunnel_dbg(tunnel, "increased bandwidth allocation to %d/%d Mb/s\n",
1324                       tunnel->allocated_up, tunnel->allocated_down);
1325 }
1326
1327 static void tb_usb3_init_credits(struct tb_path_hop *hop)
1328 {
1329         struct tb_port *port = hop->in_port;
1330         struct tb_switch *sw = port->sw;
1331         unsigned int credits;
1332
1333         if (tb_port_use_credit_allocation(port)) {
1334                 credits = sw->max_usb3_credits;
1335         } else {
1336                 if (tb_port_is_null(port))
1337                         credits = port->bonded ? 32 : 16;
1338                 else
1339                         credits = 7;
1340         }
1341
1342         hop->initial_credits = credits;
1343 }
1344
1345 static void tb_usb3_init_path(struct tb_path *path)
1346 {
1347         struct tb_path_hop *hop;
1348
1349         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1350         path->egress_shared_buffer = TB_PATH_NONE;
1351         path->ingress_fc_enable = TB_PATH_ALL;
1352         path->ingress_shared_buffer = TB_PATH_NONE;
1353         path->priority = 3;
1354         path->weight = 3;
1355         path->drop_packages = 0;
1356
1357         tb_path_for_each_hop(path, hop)
1358                 tb_usb3_init_credits(hop);
1359 }
1360
1361 /**
1362  * tb_tunnel_discover_usb3() - Discover existing USB3 tunnels
1363  * @tb: Pointer to the domain structure
1364  * @down: USB3 downstream adapter
1365  * @alloc_hopid: Allocate HopIDs from visited ports
1366  *
1367  * If @down adapter is active, follows the tunnel to the USB3 upstream
1368  * adapter and back. Returns the discovered tunnel or %NULL if there was
1369  * no tunnel.
1370  */
1371 struct tb_tunnel *tb_tunnel_discover_usb3(struct tb *tb, struct tb_port *down,
1372                                           bool alloc_hopid)
1373 {
1374         struct tb_tunnel *tunnel;
1375         struct tb_path *path;
1376
1377         if (!tb_usb3_port_is_enabled(down))
1378                 return NULL;
1379
1380         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
1381         if (!tunnel)
1382                 return NULL;
1383
1384         tunnel->activate = tb_usb3_activate;
1385         tunnel->src_port = down;
1386
1387         /*
1388          * Discover both paths even if they are not complete. We will
1389          * clean them up by calling tb_tunnel_deactivate() below in that
1390          * case.
1391          */
1392         path = tb_path_discover(down, TB_USB3_HOPID, NULL, -1,
1393                                 &tunnel->dst_port, "USB3 Down", alloc_hopid);
1394         if (!path) {
1395                 /* Just disable the downstream port */
1396                 tb_usb3_port_enable(down, false);
1397                 goto err_free;
1398         }
1399         tunnel->paths[TB_USB3_PATH_DOWN] = path;
1400         tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_DOWN]);
1401
1402         path = tb_path_discover(tunnel->dst_port, -1, down, TB_USB3_HOPID, NULL,
1403                                 "USB3 Up", alloc_hopid);
1404         if (!path)
1405                 goto err_deactivate;
1406         tunnel->paths[TB_USB3_PATH_UP] = path;
1407         tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_UP]);
1408
1409         /* Validate that the tunnel is complete */
1410         if (!tb_port_is_usb3_up(tunnel->dst_port)) {
1411                 tb_port_warn(tunnel->dst_port,
1412                              "path does not end on an USB3 adapter, cleaning up\n");
1413                 goto err_deactivate;
1414         }
1415
1416         if (down != tunnel->src_port) {
1417                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
1418                 goto err_deactivate;
1419         }
1420
1421         if (!tb_usb3_port_is_enabled(tunnel->dst_port)) {
1422                 tb_tunnel_warn(tunnel,
1423                                "tunnel is not fully activated, cleaning up\n");
1424                 goto err_deactivate;
1425         }
1426
1427         if (!tb_route(down->sw)) {
1428                 int ret;
1429
1430                 /*
1431                  * Read the initial bandwidth allocation for the first
1432                  * hop tunnel.
1433                  */
1434                 ret = usb4_usb3_port_allocated_bandwidth(down,
1435                         &tunnel->allocated_up, &tunnel->allocated_down);
1436                 if (ret)
1437                         goto err_deactivate;
1438
1439                 tb_tunnel_dbg(tunnel, "currently allocated bandwidth %d/%d Mb/s\n",
1440                               tunnel->allocated_up, tunnel->allocated_down);
1441
1442                 tunnel->init = tb_usb3_init;
1443                 tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
1444                 tunnel->release_unused_bandwidth =
1445                         tb_usb3_release_unused_bandwidth;
1446                 tunnel->reclaim_available_bandwidth =
1447                         tb_usb3_reclaim_available_bandwidth;
1448         }
1449
1450         tb_tunnel_dbg(tunnel, "discovered\n");
1451         return tunnel;
1452
1453 err_deactivate:
1454         tb_tunnel_deactivate(tunnel);
1455 err_free:
1456         tb_tunnel_free(tunnel);
1457
1458         return NULL;
1459 }
1460
1461 /**
1462  * tb_tunnel_alloc_usb3() - allocate a USB3 tunnel
1463  * @tb: Pointer to the domain structure
1464  * @up: USB3 upstream adapter port
1465  * @down: USB3 downstream adapter port
1466  * @max_up: Maximum available upstream bandwidth for the USB3 tunnel (%0
1467  *          if not limited).
1468  * @max_down: Maximum available downstream bandwidth for the USB3 tunnel
1469  *            (%0 if not limited).
1470  *
1471  * Allocate an USB3 tunnel. The ports must be of type @TB_TYPE_USB3_UP and
1472  * @TB_TYPE_USB3_DOWN.
1473  *
1474  * Return: Returns a tb_tunnel on success or %NULL on failure.
1475  */
1476 struct tb_tunnel *tb_tunnel_alloc_usb3(struct tb *tb, struct tb_port *up,
1477                                        struct tb_port *down, int max_up,
1478                                        int max_down)
1479 {
1480         struct tb_tunnel *tunnel;
1481         struct tb_path *path;
1482         int max_rate = 0;
1483
1484         /*
1485          * Check that we have enough bandwidth available for the new
1486          * USB3 tunnel.
1487          */
1488         if (max_up > 0 || max_down > 0) {
1489                 max_rate = tb_usb3_max_link_rate(down, up);
1490                 if (max_rate < 0)
1491                         return NULL;
1492
1493                 /* Only 90% can be allocated for USB3 isochronous transfers */
1494                 max_rate = max_rate * 90 / 100;
1495                 tb_port_dbg(up, "required bandwidth for USB3 tunnel %d Mb/s\n",
1496                             max_rate);
1497
1498                 if (max_rate > max_up || max_rate > max_down) {
1499                         tb_port_warn(up, "not enough bandwidth for USB3 tunnel\n");
1500                         return NULL;
1501                 }
1502         }
1503
1504         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
1505         if (!tunnel)
1506                 return NULL;
1507
1508         tunnel->activate = tb_usb3_activate;
1509         tunnel->src_port = down;
1510         tunnel->dst_port = up;
1511         tunnel->max_up = max_up;
1512         tunnel->max_down = max_down;
1513
1514         path = tb_path_alloc(tb, down, TB_USB3_HOPID, up, TB_USB3_HOPID, 0,
1515                              "USB3 Down");
1516         if (!path) {
1517                 tb_tunnel_free(tunnel);
1518                 return NULL;
1519         }
1520         tb_usb3_init_path(path);
1521         tunnel->paths[TB_USB3_PATH_DOWN] = path;
1522
1523         path = tb_path_alloc(tb, up, TB_USB3_HOPID, down, TB_USB3_HOPID, 0,
1524                              "USB3 Up");
1525         if (!path) {
1526                 tb_tunnel_free(tunnel);
1527                 return NULL;
1528         }
1529         tb_usb3_init_path(path);
1530         tunnel->paths[TB_USB3_PATH_UP] = path;
1531
1532         if (!tb_route(down->sw)) {
1533                 tunnel->allocated_up = max_rate;
1534                 tunnel->allocated_down = max_rate;
1535
1536                 tunnel->init = tb_usb3_init;
1537                 tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
1538                 tunnel->release_unused_bandwidth =
1539                         tb_usb3_release_unused_bandwidth;
1540                 tunnel->reclaim_available_bandwidth =
1541                         tb_usb3_reclaim_available_bandwidth;
1542         }
1543
1544         return tunnel;
1545 }
1546
1547 /**
1548  * tb_tunnel_free() - free a tunnel
1549  * @tunnel: Tunnel to be freed
1550  *
1551  * Frees a tunnel. The tunnel does not need to be deactivated.
1552  */
1553 void tb_tunnel_free(struct tb_tunnel *tunnel)
1554 {
1555         int i;
1556
1557         if (!tunnel)
1558                 return;
1559
1560         if (tunnel->deinit)
1561                 tunnel->deinit(tunnel);
1562
1563         for (i = 0; i < tunnel->npaths; i++) {
1564                 if (tunnel->paths[i])
1565                         tb_path_free(tunnel->paths[i]);
1566         }
1567
1568         kfree(tunnel->paths);
1569         kfree(tunnel);
1570 }
1571
1572 /**
1573  * tb_tunnel_is_invalid - check whether an activated path is still valid
1574  * @tunnel: Tunnel to check
1575  */
1576 bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
1577 {
1578         int i;
1579
1580         for (i = 0; i < tunnel->npaths; i++) {
1581                 WARN_ON(!tunnel->paths[i]->activated);
1582                 if (tb_path_is_invalid(tunnel->paths[i]))
1583                         return true;
1584         }
1585
1586         return false;
1587 }
1588
1589 /**
1590  * tb_tunnel_restart() - activate a tunnel after a hardware reset
1591  * @tunnel: Tunnel to restart
1592  *
1593  * Return: 0 on success and negative errno in case if failure
1594  */
1595 int tb_tunnel_restart(struct tb_tunnel *tunnel)
1596 {
1597         int res, i;
1598
1599         tb_tunnel_dbg(tunnel, "activating\n");
1600
1601         /*
1602          * Make sure all paths are properly disabled before enabling
1603          * them again.
1604          */
1605         for (i = 0; i < tunnel->npaths; i++) {
1606                 if (tunnel->paths[i]->activated) {
1607                         tb_path_deactivate(tunnel->paths[i]);
1608                         tunnel->paths[i]->activated = false;
1609                 }
1610         }
1611
1612         if (tunnel->init) {
1613                 res = tunnel->init(tunnel);
1614                 if (res)
1615                         return res;
1616         }
1617
1618         for (i = 0; i < tunnel->npaths; i++) {
1619                 res = tb_path_activate(tunnel->paths[i]);
1620                 if (res)
1621                         goto err;
1622         }
1623
1624         if (tunnel->activate) {
1625                 res = tunnel->activate(tunnel, true);
1626                 if (res)
1627                         goto err;
1628         }
1629
1630         return 0;
1631
1632 err:
1633         tb_tunnel_warn(tunnel, "activation failed\n");
1634         tb_tunnel_deactivate(tunnel);
1635         return res;
1636 }
1637
1638 /**
1639  * tb_tunnel_activate() - activate a tunnel
1640  * @tunnel: Tunnel to activate
1641  *
1642  * Return: Returns 0 on success or an error code on failure.
1643  */
1644 int tb_tunnel_activate(struct tb_tunnel *tunnel)
1645 {
1646         int i;
1647
1648         for (i = 0; i < tunnel->npaths; i++) {
1649                 if (tunnel->paths[i]->activated) {
1650                         tb_tunnel_WARN(tunnel,
1651                                        "trying to activate an already activated tunnel\n");
1652                         return -EINVAL;
1653                 }
1654         }
1655
1656         return tb_tunnel_restart(tunnel);
1657 }
1658
1659 /**
1660  * tb_tunnel_deactivate() - deactivate a tunnel
1661  * @tunnel: Tunnel to deactivate
1662  */
1663 void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
1664 {
1665         int i;
1666
1667         tb_tunnel_dbg(tunnel, "deactivating\n");
1668
1669         if (tunnel->activate)
1670                 tunnel->activate(tunnel, false);
1671
1672         for (i = 0; i < tunnel->npaths; i++) {
1673                 if (tunnel->paths[i] && tunnel->paths[i]->activated)
1674                         tb_path_deactivate(tunnel->paths[i]);
1675         }
1676 }
1677
1678 /**
1679  * tb_tunnel_port_on_path() - Does the tunnel go through port
1680  * @tunnel: Tunnel to check
1681  * @port: Port to check
1682  *
1683  * Returns true if @tunnel goes through @port (direction does not matter),
1684  * false otherwise.
1685  */
1686 bool tb_tunnel_port_on_path(const struct tb_tunnel *tunnel,
1687                             const struct tb_port *port)
1688 {
1689         int i;
1690
1691         for (i = 0; i < tunnel->npaths; i++) {
1692                 if (!tunnel->paths[i])
1693                         continue;
1694
1695                 if (tb_path_port_on_path(tunnel->paths[i], port))
1696                         return true;
1697         }
1698
1699         return false;
1700 }
1701
1702 static bool tb_tunnel_is_active(const struct tb_tunnel *tunnel)
1703 {
1704         int i;
1705
1706         for (i = 0; i < tunnel->npaths; i++) {
1707                 if (!tunnel->paths[i])
1708                         return false;
1709                 if (!tunnel->paths[i]->activated)
1710                         return false;
1711         }
1712
1713         return true;
1714 }
1715
1716 /**
1717  * tb_tunnel_consumed_bandwidth() - Return bandwidth consumed by the tunnel
1718  * @tunnel: Tunnel to check
1719  * @consumed_up: Consumed bandwidth in Mb/s from @dst_port to @src_port.
1720  *               Can be %NULL.
1721  * @consumed_down: Consumed bandwidth in Mb/s from @src_port to @dst_port.
1722  *                 Can be %NULL.
1723  *
1724  * Stores the amount of isochronous bandwidth @tunnel consumes in
1725  * @consumed_up and @consumed_down. In case of success returns %0,
1726  * negative errno otherwise.
1727  */
1728 int tb_tunnel_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
1729                                  int *consumed_down)
1730 {
1731         int up_bw = 0, down_bw = 0;
1732
1733         if (!tb_tunnel_is_active(tunnel))
1734                 goto out;
1735
1736         if (tunnel->consumed_bandwidth) {
1737                 int ret;
1738
1739                 ret = tunnel->consumed_bandwidth(tunnel, &up_bw, &down_bw);
1740                 if (ret)
1741                         return ret;
1742
1743                 tb_tunnel_dbg(tunnel, "consumed bandwidth %d/%d Mb/s\n", up_bw,
1744                               down_bw);
1745         }
1746
1747 out:
1748         if (consumed_up)
1749                 *consumed_up = up_bw;
1750         if (consumed_down)
1751                 *consumed_down = down_bw;
1752
1753         return 0;
1754 }
1755
1756 /**
1757  * tb_tunnel_release_unused_bandwidth() - Release unused bandwidth
1758  * @tunnel: Tunnel whose unused bandwidth to release
1759  *
1760  * If tunnel supports dynamic bandwidth management (USB3 tunnels at the
1761  * moment) this function makes it to release all the unused bandwidth.
1762  *
1763  * Returns %0 in case of success and negative errno otherwise.
1764  */
1765 int tb_tunnel_release_unused_bandwidth(struct tb_tunnel *tunnel)
1766 {
1767         if (!tb_tunnel_is_active(tunnel))
1768                 return 0;
1769
1770         if (tunnel->release_unused_bandwidth) {
1771                 int ret;
1772
1773                 ret = tunnel->release_unused_bandwidth(tunnel);
1774                 if (ret)
1775                         return ret;
1776         }
1777
1778         return 0;
1779 }
1780
1781 /**
1782  * tb_tunnel_reclaim_available_bandwidth() - Reclaim available bandwidth
1783  * @tunnel: Tunnel reclaiming available bandwidth
1784  * @available_up: Available upstream bandwidth (in Mb/s)
1785  * @available_down: Available downstream bandwidth (in Mb/s)
1786  *
1787  * Reclaims bandwidth from @available_up and @available_down and updates
1788  * the variables accordingly (e.g decreases both according to what was
1789  * reclaimed by the tunnel). If nothing was reclaimed the values are
1790  * kept as is.
1791  */
1792 void tb_tunnel_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
1793                                            int *available_up,
1794                                            int *available_down)
1795 {
1796         if (!tb_tunnel_is_active(tunnel))
1797                 return;
1798
1799         if (tunnel->reclaim_available_bandwidth)
1800                 tunnel->reclaim_available_bandwidth(tunnel, available_up,
1801                                                     available_down);
1802 }