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 #include <linux/ktime.h>
  13 #include <linux/string_helpers.h>
  14
  15 #include "tunnel.h"
  16 #include "tb.h"
  17
  18 /* PCIe adapters use always HopID of 8 for both directions */
  19 #define TB_PCI_HOPID                    8
  20
  21 #define TB_PCI_PATH_DOWN                0
  22 #define TB_PCI_PATH_UP                  1
  23
  24 #define TB_PCI_PRIORITY                 3
  25 #define TB_PCI_WEIGHT                   1
  26
  27 /* USB3 adapters use always HopID of 8 for both directions */
  28 #define TB_USB3_HOPID                   8
  29
  30 #define TB_USB3_PATH_DOWN               0
  31 #define TB_USB3_PATH_UP                 1
  32
  33 #define TB_USB3_PRIORITY                3
  34 #define TB_USB3_WEIGHT                  2
  35
  36 /* DP adapters use HopID 8 for AUX and 9 for Video */
  37 #define TB_DP_AUX_TX_HOPID              8
  38 #define TB_DP_AUX_RX_HOPID              8
  39 #define TB_DP_VIDEO_HOPID               9
  40
  41 #define TB_DP_VIDEO_PATH_OUT            0
  42 #define TB_DP_AUX_PATH_OUT              1
  43 #define TB_DP_AUX_PATH_IN               2
  44
  45 #define TB_DP_VIDEO_PRIORITY            1
  46 #define TB_DP_VIDEO_WEIGHT              1
  47
  48 #define TB_DP_AUX_PRIORITY              2
  49 #define TB_DP_AUX_WEIGHT                1
  50
  51 /* Minimum number of credits needed for PCIe path */
  52 #define TB_MIN_PCIE_CREDITS             6U
  53 /*
  54  * Number of credits we try to allocate for each DMA path if not limited
  55  * by the host router baMaxHI.
  56  */
  57 #define TB_DMA_CREDITS                  14
  58 /* Minimum number of credits for DMA path */
  59 #define TB_MIN_DMA_CREDITS              1
  60
  61 #define TB_DMA_PRIORITY                 5
  62 #define TB_DMA_WEIGHT                   1
  63
  64 /*
  65  * Reserve additional bandwidth for USB 3.x and PCIe bulk traffic
  66  * according to USB4 v2 Connection Manager guide. This ends up reserving
  67  * 1500 Mb/s for PCIe and 3000 Mb/s for USB 3.x taking weights into
  68  * account.
  69  */
  70 #define USB4_V2_PCI_MIN_BANDWIDTH       (1500 * TB_PCI_WEIGHT)
  71 #define USB4_V2_USB3_MIN_BANDWIDTH      (1500 * TB_USB3_WEIGHT)
  72
  73 static unsigned int dma_credits = TB_DMA_CREDITS;
  74 module_param(dma_credits, uint, 0444);
  75 MODULE_PARM_DESC(dma_credits, "specify custom credits for DMA tunnels (default: "
  76                 __MODULE_STRING(TB_DMA_CREDITS) ")");
  77
  78 static bool bw_alloc_mode = true;
  79 module_param(bw_alloc_mode, bool, 0444);
  80 MODULE_PARM_DESC(bw_alloc_mode,
  81                  "enable bandwidth allocation mode if supported (default: true)");
  82
  83 static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA", "USB3" };
  84
  85 static inline unsigned int tb_usable_credits(const struct tb_port *port)
  86 {
  87         return port->total_credits - port->ctl_credits;
  88 }
  89
  90 /**
  91  * tb_available_credits() - Available credits for PCIe and DMA
  92  * @port: Lane adapter to check
  93  * @max_dp_streams: If non-%NULL stores maximum number of simultaneous DP
  94  *                  streams possible through this lane adapter
  95  */
  96 static unsigned int tb_available_credits(const struct tb_port *port,
  97                                          size_t *max_dp_streams)
  98 {
  99         const struct tb_switch *sw = port->sw;
 100         int credits, usb3, pcie, spare;
 101         size_t ndp;
 102
 103         usb3 = tb_acpi_may_tunnel_usb3() ? sw->max_usb3_credits : 0;
 104         pcie = tb_acpi_may_tunnel_pcie() ? sw->max_pcie_credits : 0;
 105
 106         if (tb_acpi_is_xdomain_allowed()) {
 107                 spare = min_not_zero(sw->max_dma_credits, dma_credits);
 108                 /* Add some credits for potential second DMA tunnel */
 109                 spare += TB_MIN_DMA_CREDITS;
 110         } else {
 111                 spare = 0;
 112         }
 113
 114         credits = tb_usable_credits(port);
 115         if (tb_acpi_may_tunnel_dp()) {
 116                 /*
 117                  * Maximum number of DP streams possible through the
 118                  * lane adapter.
 119                  */
 120                 if (sw->min_dp_aux_credits + sw->min_dp_main_credits)
 121                         ndp = (credits - (usb3 + pcie + spare)) /
 122                               (sw->min_dp_aux_credits + sw->min_dp_main_credits);
 123                 else
 124                         ndp = 0;
 125         } else {
 126                 ndp = 0;
 127         }
 128         credits -= ndp * (sw->min_dp_aux_credits + sw->min_dp_main_credits);
 129         credits -= usb3;
 130
 131         if (max_dp_streams)
 132                 *max_dp_streams = ndp;
 133
 134         return credits > 0 ? credits : 0;
 135 }
 136
 137 static void tb_init_pm_support(struct tb_path_hop *hop)
 138 {
 139         struct tb_port *out_port = hop->out_port;
 140         struct tb_port *in_port = hop->in_port;
 141
 142         if (tb_port_is_null(in_port) && tb_port_is_null(out_port) &&
 143             usb4_switch_version(in_port->sw) >= 2)
 144                 hop->pm_support = true;
 145 }
 146
 147 static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
 148                                          enum tb_tunnel_type type)
 149 {
 150         struct tb_tunnel *tunnel;
 151
 152         tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
 153         if (!tunnel)
 154                 return NULL;
 155
 156         tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL);
 157         if (!tunnel->paths) {
 158                 tb_tunnel_free(tunnel);
 159                 return NULL;
 160         }
 161
 162         INIT_LIST_HEAD(&tunnel->list);
 163         tunnel->tb = tb;
 164         tunnel->npaths = npaths;
 165         tunnel->type = type;
 166
 167         return tunnel;
 168 }
 169
 170 static int tb_pci_set_ext_encapsulation(struct tb_tunnel *tunnel, bool enable)
 171 {
 172         struct tb_port *port = tb_upstream_port(tunnel->dst_port->sw);
 173         int ret;
 174
 175         /* Only supported of both routers are at least USB4 v2 */
 176         if ((usb4_switch_version(tunnel->src_port->sw) < 2) ||
 177            (usb4_switch_version(tunnel->dst_port->sw) < 2))
 178                 return 0;
 179
 180         if (enable && tb_port_get_link_generation(port) < 4)
 181                 return 0;
 182
 183         ret = usb4_pci_port_set_ext_encapsulation(tunnel->src_port, enable);
 184         if (ret)
 185                 return ret;
 186
 187         /*
 188          * Downstream router could be unplugged so disable of encapsulation
 189          * in upstream router is still possible.
 190          */
 191         ret = usb4_pci_port_set_ext_encapsulation(tunnel->dst_port, enable);
 192         if (ret) {
 193                 if (enable)
 194                         return ret;
 195                 if (ret != -ENODEV)
 196                         return ret;
 197         }
 198
 199         tb_tunnel_dbg(tunnel, "extended encapsulation %s\n",
 200                       str_enabled_disabled(enable));
 201         return 0;
 202 }
 203
 204 static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)
 205 {
 206         int res;
 207
 208         if (activate) {
 209                 res = tb_pci_set_ext_encapsulation(tunnel, activate);
 210                 if (res)
 211                         return res;
 212         }
 213
 214         if (activate)
 215                 res = tb_pci_port_enable(tunnel->dst_port, activate);
 216         else
 217                 res = tb_pci_port_enable(tunnel->src_port, activate);
 218         if (res)
 219                 return res;
 220
 221
 222         if (activate) {
 223                 res = tb_pci_port_enable(tunnel->src_port, activate);
 224                 if (res)
 225                         return res;
 226         } else {
 227                 /* Downstream router could be unplugged */
 228                 tb_pci_port_enable(tunnel->dst_port, activate);
 229         }
 230
 231         return activate ? 0 : tb_pci_set_ext_encapsulation(tunnel, activate);
 232 }
 233
 234 static int tb_pci_init_credits(struct tb_path_hop *hop)
 235 {
 236         struct tb_port *port = hop->in_port;
 237         struct tb_switch *sw = port->sw;
 238         unsigned int credits;
 239
 240         if (tb_port_use_credit_allocation(port)) {
 241                 unsigned int available;
 242
 243                 available = tb_available_credits(port, NULL);
 244                 credits = min(sw->max_pcie_credits, available);
 245
 246                 if (credits < TB_MIN_PCIE_CREDITS)
 247                         return -ENOSPC;
 248
 249                 credits = max(TB_MIN_PCIE_CREDITS, credits);
 250         } else {
 251                 if (tb_port_is_null(port))
 252                         credits = port->bonded ? 32 : 16;
 253                 else
 254                         credits = 7;
 255         }
 256
 257         hop->initial_credits = credits;
 258         return 0;
 259 }
 260
 261 static int tb_pci_init_path(struct tb_path *path)
 262 {
 263         struct tb_path_hop *hop;
 264
 265         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
 266         path->egress_shared_buffer = TB_PATH_NONE;
 267         path->ingress_fc_enable = TB_PATH_ALL;
 268         path->ingress_shared_buffer = TB_PATH_NONE;
 269         path->priority = TB_PCI_PRIORITY;
 270         path->weight = TB_PCI_WEIGHT;
 271         path->drop_packages = 0;
 272
 273         tb_path_for_each_hop(path, hop) {
 274                 int ret;
 275
 276                 ret = tb_pci_init_credits(hop);
 277                 if (ret)
 278                         return ret;
 279         }
 280
 281         return 0;
 282 }
 283
 284 /**
 285  * tb_tunnel_discover_pci() - Discover existing PCIe tunnels
 286  * @tb: Pointer to the domain structure
 287  * @down: PCIe downstream adapter
 288  * @alloc_hopid: Allocate HopIDs from visited ports
 289  *
 290  * If @down adapter is active, follows the tunnel to the PCIe upstream
 291  * adapter and back. Returns the discovered tunnel or %NULL if there was
 292  * no tunnel.
 293  */
 294 struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down,
 295                                          bool alloc_hopid)
 296 {
 297         struct tb_tunnel *tunnel;
 298         struct tb_path *path;
 299
 300         if (!tb_pci_port_is_enabled(down))
 301                 return NULL;
 302
 303         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
 304         if (!tunnel)
 305                 return NULL;
 306
 307         tunnel->activate = tb_pci_activate;
 308         tunnel->src_port = down;
 309
 310         /*
 311          * Discover both paths even if they are not complete. We will
 312          * clean them up by calling tb_tunnel_deactivate() below in that
 313          * case.
 314          */
 315         path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1,
 316                                 &tunnel->dst_port, "PCIe Up", alloc_hopid);
 317         if (!path) {
 318                 /* Just disable the downstream port */
 319                 tb_pci_port_enable(down, false);
 320                 goto err_free;
 321         }
 322         tunnel->paths[TB_PCI_PATH_UP] = path;
 323         if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]))
 324                 goto err_free;
 325
 326         path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL,
 327                                 "PCIe Down", alloc_hopid);
 328         if (!path)
 329                 goto err_deactivate;
 330         tunnel->paths[TB_PCI_PATH_DOWN] = path;
 331         if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]))
 332                 goto err_deactivate;
 333
 334         /* Validate that the tunnel is complete */
 335         if (!tb_port_is_pcie_up(tunnel->dst_port)) {
 336                 tb_port_warn(tunnel->dst_port,
 337                              "path does not end on a PCIe adapter, cleaning up\n");
 338                 goto err_deactivate;
 339         }
 340
 341         if (down != tunnel->src_port) {
 342                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
 343                 goto err_deactivate;
 344         }
 345
 346         if (!tb_pci_port_is_enabled(tunnel->dst_port)) {
 347                 tb_tunnel_warn(tunnel,
 348                                "tunnel is not fully activated, cleaning up\n");
 349                 goto err_deactivate;
 350         }
 351
 352         tb_tunnel_dbg(tunnel, "discovered\n");
 353         return tunnel;
 354
 355 err_deactivate:
 356         tb_tunnel_deactivate(tunnel);
 357 err_free:
 358         tb_tunnel_free(tunnel);
 359
 360         return NULL;
 361 }
 362
 363 /**
 364  * tb_tunnel_alloc_pci() - allocate a pci tunnel
 365  * @tb: Pointer to the domain structure
 366  * @up: PCIe upstream adapter port
 367  * @down: PCIe downstream adapter port
 368  *
 369  * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
 370  * TB_TYPE_PCIE_DOWN.
 371  *
 372  * Return: Returns a tb_tunnel on success or NULL on failure.
 373  */
 374 struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
 375                                       struct tb_port *down)
 376 {
 377         struct tb_tunnel *tunnel;
 378         struct tb_path *path;
 379
 380         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
 381         if (!tunnel)
 382                 return NULL;
 383
 384         tunnel->activate = tb_pci_activate;
 385         tunnel->src_port = down;
 386         tunnel->dst_port = up;
 387
 388         path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0,
 389                              "PCIe Down");
 390         if (!path)
 391                 goto err_free;
 392         tunnel->paths[TB_PCI_PATH_DOWN] = path;
 393         if (tb_pci_init_path(path))
 394                 goto err_free;
 395
 396         path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0,
 397                              "PCIe Up");
 398         if (!path)
 399                 goto err_free;
 400         tunnel->paths[TB_PCI_PATH_UP] = path;
 401         if (tb_pci_init_path(path))
 402                 goto err_free;
 403
 404         return tunnel;
 405
 406 err_free:
 407         tb_tunnel_free(tunnel);
 408         return NULL;
 409 }
 410
 411 /**
 412  * tb_tunnel_reserved_pci() - Amount of bandwidth to reserve for PCIe
 413  * @port: Lane 0 adapter
 414  * @reserved_up: Upstream bandwidth in Mb/s to reserve
 415  * @reserved_down: Downstream bandwidth in Mb/s to reserve
 416  *
 417  * Can be called to any connected lane 0 adapter to find out how much
 418  * bandwidth needs to be left in reserve for possible PCIe bulk traffic.
 419  * Returns true if there is something to be reserved and writes the
 420  * amount to @reserved_down/@reserved_up. Otherwise returns false and
 421  * does not touch the parameters.
 422  */
 423 bool tb_tunnel_reserved_pci(struct tb_port *port, int *reserved_up,
 424                             int *reserved_down)
 425 {
 426         if (WARN_ON_ONCE(!port->remote))
 427                 return false;
 428
 429         if (!tb_acpi_may_tunnel_pcie())
 430                 return false;
 431
 432         if (tb_port_get_link_generation(port) < 4)
 433                 return false;
 434
 435         /* Must have PCIe adapters */
 436         if (tb_is_upstream_port(port)) {
 437                 if (!tb_switch_find_port(port->sw, TB_TYPE_PCIE_UP))
 438                         return false;
 439                 if (!tb_switch_find_port(port->remote->sw, TB_TYPE_PCIE_DOWN))
 440                         return false;
 441         } else {
 442                 if (!tb_switch_find_port(port->sw, TB_TYPE_PCIE_DOWN))
 443                         return false;
 444                 if (!tb_switch_find_port(port->remote->sw, TB_TYPE_PCIE_UP))
 445                         return false;
 446         }
 447
 448         *reserved_up = USB4_V2_PCI_MIN_BANDWIDTH;
 449         *reserved_down = USB4_V2_PCI_MIN_BANDWIDTH;
 450
 451         tb_port_dbg(port, "reserving %u/%u Mb/s for PCIe\n", *reserved_up,
 452                     *reserved_down);
 453         return true;
 454 }
 455
 456 static bool tb_dp_is_usb4(const struct tb_switch *sw)
 457 {
 458         /* Titan Ridge DP adapters need the same treatment as USB4 */
 459         return tb_switch_is_usb4(sw) || tb_switch_is_titan_ridge(sw);
 460 }
 461
 462 static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out,
 463                               int timeout_msec)
 464 {
 465         ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
 466         u32 val;
 467         int ret;
 468
 469         /* Both ends need to support this */
 470         if (!tb_dp_is_usb4(in->sw) || !tb_dp_is_usb4(out->sw))
 471                 return 0;
 472
 473         ret = tb_port_read(out, &val, TB_CFG_PORT,
 474                            out->cap_adap + DP_STATUS_CTRL, 1);
 475         if (ret)
 476                 return ret;
 477
 478         val |= DP_STATUS_CTRL_UF | DP_STATUS_CTRL_CMHS;
 479
 480         ret = tb_port_write(out, &val, TB_CFG_PORT,
 481                             out->cap_adap + DP_STATUS_CTRL, 1);
 482         if (ret)
 483                 return ret;
 484
 485         do {
 486                 ret = tb_port_read(out, &val, TB_CFG_PORT,
 487                                    out->cap_adap + DP_STATUS_CTRL, 1);
 488                 if (ret)
 489                         return ret;
 490                 if (!(val & DP_STATUS_CTRL_CMHS))
 491                         return 0;
 492                 usleep_range(100, 150);
 493         } while (ktime_before(ktime_get(), timeout));
 494
 495         return -ETIMEDOUT;
 496 }
 497
 498 /*
 499  * Returns maximum possible rate from capability supporting only DP 2.0
 500  * and below. Used when DP BW allocation mode is not enabled.
 501  */
 502 static inline u32 tb_dp_cap_get_rate(u32 val)
 503 {
 504         u32 rate = (val & DP_COMMON_CAP_RATE_MASK) >> DP_COMMON_CAP_RATE_SHIFT;
 505
 506         switch (rate) {
 507         case DP_COMMON_CAP_RATE_RBR:
 508                 return 1620;
 509         case DP_COMMON_CAP_RATE_HBR:
 510                 return 2700;
 511         case DP_COMMON_CAP_RATE_HBR2:
 512                 return 5400;
 513         case DP_COMMON_CAP_RATE_HBR3:
 514                 return 8100;
 515         default:
 516                 return 0;
 517         }
 518 }
 519
 520 /*
 521  * Returns maximum possible rate from capability supporting DP 2.1
 522  * UHBR20, 13.5 and 10 rates as well. Use only when DP BW allocation
 523  * mode is enabled.
 524  */
 525 static inline u32 tb_dp_cap_get_rate_ext(u32 val)
 526 {
 527         if (val & DP_COMMON_CAP_UHBR20)
 528                 return 20000;
 529         else if (val & DP_COMMON_CAP_UHBR13_5)
 530                 return 13500;
 531         else if (val & DP_COMMON_CAP_UHBR10)
 532                 return 10000;
 533
 534         return tb_dp_cap_get_rate(val);
 535 }
 536
 537 static inline bool tb_dp_is_uhbr_rate(unsigned int rate)
 538 {
 539         return rate >= 10000;
 540 }
 541
 542 static inline u32 tb_dp_cap_set_rate(u32 val, u32 rate)
 543 {
 544         val &= ~DP_COMMON_CAP_RATE_MASK;
 545         switch (rate) {
 546         default:
 547                 WARN(1, "invalid rate %u passed, defaulting to 1620 MB/s\n", rate);
 548                 fallthrough;
 549         case 1620:
 550                 val |= DP_COMMON_CAP_RATE_RBR << DP_COMMON_CAP_RATE_SHIFT;
 551                 break;
 552         case 2700:
 553                 val |= DP_COMMON_CAP_RATE_HBR << DP_COMMON_CAP_RATE_SHIFT;
 554                 break;
 555         case 5400:
 556                 val |= DP_COMMON_CAP_RATE_HBR2 << DP_COMMON_CAP_RATE_SHIFT;
 557                 break;
 558         case 8100:
 559                 val |= DP_COMMON_CAP_RATE_HBR3 << DP_COMMON_CAP_RATE_SHIFT;
 560                 break;
 561         }
 562         return val;
 563 }
 564
 565 static inline u32 tb_dp_cap_get_lanes(u32 val)
 566 {
 567         u32 lanes = (val & DP_COMMON_CAP_LANES_MASK) >> DP_COMMON_CAP_LANES_SHIFT;
 568
 569         switch (lanes) {
 570         case DP_COMMON_CAP_1_LANE:
 571                 return 1;
 572         case DP_COMMON_CAP_2_LANES:
 573                 return 2;
 574         case DP_COMMON_CAP_4_LANES:
 575                 return 4;
 576         default:
 577                 return 0;
 578         }
 579 }
 580
 581 static inline u32 tb_dp_cap_set_lanes(u32 val, u32 lanes)
 582 {
 583         val &= ~DP_COMMON_CAP_LANES_MASK;
 584         switch (lanes) {
 585         default:
 586                 WARN(1, "invalid number of lanes %u passed, defaulting to 1\n",
 587                      lanes);
 588                 fallthrough;
 589         case 1:
 590                 val |= DP_COMMON_CAP_1_LANE << DP_COMMON_CAP_LANES_SHIFT;
 591                 break;
 592         case 2:
 593                 val |= DP_COMMON_CAP_2_LANES << DP_COMMON_CAP_LANES_SHIFT;
 594                 break;
 595         case 4:
 596                 val |= DP_COMMON_CAP_4_LANES << DP_COMMON_CAP_LANES_SHIFT;
 597                 break;
 598         }
 599         return val;
 600 }
 601
 602 static unsigned int tb_dp_bandwidth(unsigned int rate, unsigned int lanes)
 603 {
 604         /* Tunneling removes the DP 8b/10b 128/132b encoding */
 605         if (tb_dp_is_uhbr_rate(rate))
 606                 return rate * lanes * 128 / 132;
 607         return rate * lanes * 8 / 10;
 608 }
 609
 610 static int tb_dp_reduce_bandwidth(int max_bw, u32 in_rate, u32 in_lanes,
 611                                   u32 out_rate, u32 out_lanes, u32 *new_rate,
 612                                   u32 *new_lanes)
 613 {
 614         static const u32 dp_bw[][2] = {
 615                 /* Mb/s, lanes */
 616                 { 8100, 4 }, /* 25920 Mb/s */
 617                 { 5400, 4 }, /* 17280 Mb/s */
 618                 { 8100, 2 }, /* 12960 Mb/s */
 619                 { 2700, 4 }, /* 8640 Mb/s */
 620                 { 5400, 2 }, /* 8640 Mb/s */
 621                 { 8100, 1 }, /* 6480 Mb/s */
 622                 { 1620, 4 }, /* 5184 Mb/s */
 623                 { 5400, 1 }, /* 4320 Mb/s */
 624                 { 2700, 2 }, /* 4320 Mb/s */
 625                 { 1620, 2 }, /* 2592 Mb/s */
 626                 { 2700, 1 }, /* 2160 Mb/s */
 627                 { 1620, 1 }, /* 1296 Mb/s */
 628         };
 629         unsigned int i;
 630
 631         /*
 632          * Find a combination that can fit into max_bw and does not
 633          * exceed the maximum rate and lanes supported by the DP OUT and
 634          * DP IN adapters.
 635          */
 636         for (i = 0; i < ARRAY_SIZE(dp_bw); i++) {
 637                 if (dp_bw[i][0] > out_rate || dp_bw[i][1] > out_lanes)
 638                         continue;
 639
 640                 if (dp_bw[i][0] > in_rate || dp_bw[i][1] > in_lanes)
 641                         continue;
 642
 643                 if (tb_dp_bandwidth(dp_bw[i][0], dp_bw[i][1]) <= max_bw) {
 644                         *new_rate = dp_bw[i][0];
 645                         *new_lanes = dp_bw[i][1];
 646                         return 0;
 647                 }
 648         }
 649
 650         return -ENOSR;
 651 }
 652
 653 static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
 654 {
 655         u32 out_dp_cap, out_rate, out_lanes, in_dp_cap, in_rate, in_lanes, bw;
 656         struct tb_port *out = tunnel->dst_port;
 657         struct tb_port *in = tunnel->src_port;
 658         int ret, max_bw;
 659
 660         /*
 661          * Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for
 662          * newer generation hardware.
 663          */
 664         if (in->sw->generation < 2 || out->sw->generation < 2)
 665                 return 0;
 666
 667         /*
 668          * Perform connection manager handshake between IN and OUT ports
 669          * before capabilities exchange can take place.
 670          */
 671         ret = tb_dp_cm_handshake(in, out, 3000);
 672         if (ret)
 673                 return ret;
 674
 675         /* Read both DP_LOCAL_CAP registers */
 676         ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
 677                            in->cap_adap + DP_LOCAL_CAP, 1);
 678         if (ret)
 679                 return ret;
 680
 681         ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
 682                            out->cap_adap + DP_LOCAL_CAP, 1);
 683         if (ret)
 684                 return ret;
 685
 686         /* Write IN local caps to OUT remote caps */
 687         ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT,
 688                             out->cap_adap + DP_REMOTE_CAP, 1);
 689         if (ret)
 690                 return ret;
 691
 692         in_rate = tb_dp_cap_get_rate(in_dp_cap);
 693         in_lanes = tb_dp_cap_get_lanes(in_dp_cap);
 694         tb_tunnel_dbg(tunnel,
 695                       "DP IN maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
 696                       in_rate, in_lanes, tb_dp_bandwidth(in_rate, in_lanes));
 697
 698         /*
 699          * If the tunnel bandwidth is limited (max_bw is set) then see
 700          * if we need to reduce bandwidth to fit there.
 701          */
 702         out_rate = tb_dp_cap_get_rate(out_dp_cap);
 703         out_lanes = tb_dp_cap_get_lanes(out_dp_cap);
 704         bw = tb_dp_bandwidth(out_rate, out_lanes);
 705         tb_tunnel_dbg(tunnel,
 706                       "DP OUT maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
 707                       out_rate, out_lanes, bw);
 708
 709         if (tb_port_path_direction_downstream(in, out))
 710                 max_bw = tunnel->max_down;
 711         else
 712                 max_bw = tunnel->max_up;
 713
 714         if (max_bw && bw > max_bw) {
 715                 u32 new_rate, new_lanes, new_bw;
 716
 717                 ret = tb_dp_reduce_bandwidth(max_bw, in_rate, in_lanes,
 718                                              out_rate, out_lanes, &new_rate,
 719                                              &new_lanes);
 720                 if (ret) {
 721                         tb_tunnel_info(tunnel, "not enough bandwidth\n");
 722                         return ret;
 723                 }
 724
 725                 new_bw = tb_dp_bandwidth(new_rate, new_lanes);
 726                 tb_tunnel_dbg(tunnel,
 727                               "bandwidth reduced to %u Mb/s x%u = %u Mb/s\n",
 728                               new_rate, new_lanes, new_bw);
 729
 730                 /*
 731                  * Set new rate and number of lanes before writing it to
 732                  * the IN port remote caps.
 733                  */
 734                 out_dp_cap = tb_dp_cap_set_rate(out_dp_cap, new_rate);
 735                 out_dp_cap = tb_dp_cap_set_lanes(out_dp_cap, new_lanes);
 736         }
 737
 738         /*
 739          * Titan Ridge does not disable AUX timers when it gets
 740          * SET_CONFIG with SET_LTTPR_MODE set. This causes problems with
 741          * DP tunneling.
 742          */
 743         if (tb_route(out->sw) && tb_switch_is_titan_ridge(out->sw)) {
 744                 out_dp_cap |= DP_COMMON_CAP_LTTPR_NS;
 745                 tb_tunnel_dbg(tunnel, "disabling LTTPR\n");
 746         }
 747
 748         return tb_port_write(in, &out_dp_cap, TB_CFG_PORT,
 749                              in->cap_adap + DP_REMOTE_CAP, 1);
 750 }
 751
 752 static int tb_dp_bandwidth_alloc_mode_enable(struct tb_tunnel *tunnel)
 753 {
 754         int ret, estimated_bw, granularity, tmp;
 755         struct tb_port *out = tunnel->dst_port;
 756         struct tb_port *in = tunnel->src_port;
 757         u32 out_dp_cap, out_rate, out_lanes;
 758         u32 in_dp_cap, in_rate, in_lanes;
 759         u32 rate, lanes;
 760
 761         if (!bw_alloc_mode)
 762                 return 0;
 763
 764         ret = usb4_dp_port_set_cm_bandwidth_mode_supported(in, true);
 765         if (ret)
 766                 return ret;
 767
 768         ret = usb4_dp_port_set_group_id(in, in->group->index);
 769         if (ret)
 770                 return ret;
 771
 772         /*
 773          * Get the non-reduced rate and lanes based on the lowest
 774          * capability of both adapters.
 775          */
 776         ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
 777                            in->cap_adap + DP_LOCAL_CAP, 1);
 778         if (ret)
 779                 return ret;
 780
 781         ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
 782                            out->cap_adap + DP_LOCAL_CAP, 1);
 783         if (ret)
 784                 return ret;
 785
 786         in_rate = tb_dp_cap_get_rate(in_dp_cap);
 787         in_lanes = tb_dp_cap_get_lanes(in_dp_cap);
 788         out_rate = tb_dp_cap_get_rate(out_dp_cap);
 789         out_lanes = tb_dp_cap_get_lanes(out_dp_cap);
 790
 791         rate = min(in_rate, out_rate);
 792         lanes = min(in_lanes, out_lanes);
 793         tmp = tb_dp_bandwidth(rate, lanes);
 794
 795         tb_tunnel_dbg(tunnel, "non-reduced bandwidth %u Mb/s x%u = %u Mb/s\n",
 796                       rate, lanes, tmp);
 797
 798         ret = usb4_dp_port_set_nrd(in, rate, lanes);
 799         if (ret)
 800                 return ret;
 801
 802         /*
 803          * Pick up granularity that supports maximum possible bandwidth.
 804          * For that we use the UHBR rates too.
 805          */
 806         in_rate = tb_dp_cap_get_rate_ext(in_dp_cap);
 807         out_rate = tb_dp_cap_get_rate_ext(out_dp_cap);
 808         rate = min(in_rate, out_rate);
 809         tmp = tb_dp_bandwidth(rate, lanes);
 810
 811         tb_tunnel_dbg(tunnel,
 812                       "maximum bandwidth through allocation mode %u Mb/s x%u = %u Mb/s\n",
 813                       rate, lanes, tmp);
 814
 815         for (granularity = 250; tmp / granularity > 255 && granularity <= 1000;
 816              granularity *= 2)
 817                 ;
 818
 819         tb_tunnel_dbg(tunnel, "granularity %d Mb/s\n", granularity);
 820
 821         /*
 822          * Returns -EINVAL if granularity above is outside of the
 823          * accepted ranges.
 824          */
 825         ret = usb4_dp_port_set_granularity(in, granularity);
 826         if (ret)
 827                 return ret;
 828
 829         /*
 830          * Bandwidth estimation is pretty much what we have in
 831          * max_up/down fields. For discovery we just read what the
 832          * estimation was set to.
 833          */
 834         if (tb_port_path_direction_downstream(in, out))
 835                 estimated_bw = tunnel->max_down;
 836         else
 837                 estimated_bw = tunnel->max_up;
 838
 839         tb_tunnel_dbg(tunnel, "estimated bandwidth %d Mb/s\n", estimated_bw);
 840
 841         ret = usb4_dp_port_set_estimated_bandwidth(in, estimated_bw);
 842         if (ret)
 843                 return ret;
 844
 845         /* Initial allocation should be 0 according the spec */
 846         ret = usb4_dp_port_allocate_bandwidth(in, 0);
 847         if (ret)
 848                 return ret;
 849
 850         tb_tunnel_dbg(tunnel, "bandwidth allocation mode enabled\n");
 851         return 0;
 852 }
 853
 854 static int tb_dp_init(struct tb_tunnel *tunnel)
 855 {
 856         struct tb_port *in = tunnel->src_port;
 857         struct tb_switch *sw = in->sw;
 858         struct tb *tb = in->sw->tb;
 859         int ret;
 860
 861         ret = tb_dp_xchg_caps(tunnel);
 862         if (ret)
 863                 return ret;
 864
 865         if (!tb_switch_is_usb4(sw))
 866                 return 0;
 867
 868         if (!usb4_dp_port_bandwidth_mode_supported(in))
 869                 return 0;
 870
 871         tb_tunnel_dbg(tunnel, "bandwidth allocation mode supported\n");
 872
 873         ret = usb4_dp_port_set_cm_id(in, tb->index);
 874         if (ret)
 875                 return ret;
 876
 877         return tb_dp_bandwidth_alloc_mode_enable(tunnel);
 878 }
 879
 880 static void tb_dp_deinit(struct tb_tunnel *tunnel)
 881 {
 882         struct tb_port *in = tunnel->src_port;
 883
 884         if (!usb4_dp_port_bandwidth_mode_supported(in))
 885                 return;
 886         if (usb4_dp_port_bandwidth_mode_enabled(in)) {
 887                 usb4_dp_port_set_cm_bandwidth_mode_supported(in, false);
 888                 tb_tunnel_dbg(tunnel, "bandwidth allocation mode disabled\n");
 889         }
 890 }
 891
 892 static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
 893 {
 894         int ret;
 895
 896         if (active) {
 897                 struct tb_path **paths;
 898                 int last;
 899
 900                 paths = tunnel->paths;
 901                 last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;
 902
 903                 tb_dp_port_set_hops(tunnel->src_port,
 904                         paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,
 905                         paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,
 906                         paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);
 907
 908                 tb_dp_port_set_hops(tunnel->dst_port,
 909                         paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,
 910                         paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,
 911                         paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);
 912         } else {
 913                 tb_dp_port_hpd_clear(tunnel->src_port);
 914                 tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0);
 915                 if (tb_port_is_dpout(tunnel->dst_port))
 916                         tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0);
 917         }
 918
 919         ret = tb_dp_port_enable(tunnel->src_port, active);
 920         if (ret)
 921                 return ret;
 922
 923         if (tb_port_is_dpout(tunnel->dst_port))
 924                 return tb_dp_port_enable(tunnel->dst_port, active);
 925
 926         return 0;
 927 }
 928
 929 /* max_bw is rounded up to next granularity */
 930 static int tb_dp_bandwidth_mode_maximum_bandwidth(struct tb_tunnel *tunnel,
 931                                                   int *max_bw)
 932 {
 933         struct tb_port *in = tunnel->src_port;
 934         int ret, rate, lanes, nrd_bw;
 935         u32 cap;
 936
 937         /*
 938          * DP IN adapter DP_LOCAL_CAP gets updated to the lowest AUX
 939          * read parameter values so this so we can use this to determine
 940          * the maximum possible bandwidth over this link.
 941          *
 942          * See USB4 v2 spec 1.0 10.4.4.5.
 943          */
 944         ret = tb_port_read(in, &cap, TB_CFG_PORT,
 945                            in->cap_adap + DP_LOCAL_CAP, 1);
 946         if (ret)
 947                 return ret;
 948
 949         rate = tb_dp_cap_get_rate_ext(cap);
 950         if (tb_dp_is_uhbr_rate(rate)) {
 951                 /*
 952                  * When UHBR is used there is no reduction in lanes so
 953                  * we can use this directly.
 954                  */
 955                 lanes = tb_dp_cap_get_lanes(cap);
 956         } else {
 957                 /*
 958                  * If there is no UHBR supported then check the
 959                  * non-reduced rate and lanes.
 960                  */
 961                 ret = usb4_dp_port_nrd(in, &rate, &lanes);
 962                 if (ret)
 963                         return ret;
 964         }
 965
 966         nrd_bw = tb_dp_bandwidth(rate, lanes);
 967
 968         if (max_bw) {
 969                 ret = usb4_dp_port_granularity(in);
 970                 if (ret < 0)
 971                         return ret;
 972                 *max_bw = roundup(nrd_bw, ret);
 973         }
 974
 975         return nrd_bw;
 976 }
 977
 978 static int tb_dp_bandwidth_mode_consumed_bandwidth(struct tb_tunnel *tunnel,
 979                                                    int *consumed_up,
 980                                                    int *consumed_down)
 981 {
 982         struct tb_port *out = tunnel->dst_port;
 983         struct tb_port *in = tunnel->src_port;
 984         int ret, allocated_bw, max_bw;
 985
 986         if (!usb4_dp_port_bandwidth_mode_enabled(in))
 987                 return -EOPNOTSUPP;
 988
 989         if (!tunnel->bw_mode)
 990                 return -EOPNOTSUPP;
 991
 992         /* Read what was allocated previously if any */
 993         ret = usb4_dp_port_allocated_bandwidth(in);
 994         if (ret < 0)
 995                 return ret;
 996         allocated_bw = ret;
 997
 998         ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw);
 999         if (ret < 0)
1000                 return ret;
1001         if (allocated_bw == max_bw)
1002                 allocated_bw = ret;
1003
1004         if (tb_port_path_direction_downstream(in, out)) {
1005                 *consumed_up = 0;
1006                 *consumed_down = allocated_bw;
1007         } else {
1008                 *consumed_up = allocated_bw;
1009                 *consumed_down = 0;
1010         }
1011
1012         return 0;
1013 }
1014
1015 static int tb_dp_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,
1016                                      int *allocated_down)
1017 {
1018         struct tb_port *out = tunnel->dst_port;
1019         struct tb_port *in = tunnel->src_port;
1020
1021         /*
1022          * If we have already set the allocated bandwidth then use that.
1023          * Otherwise we read it from the DPRX.
1024          */
1025         if (usb4_dp_port_bandwidth_mode_enabled(in) && tunnel->bw_mode) {
1026                 int ret, allocated_bw, max_bw;
1027
1028                 ret = usb4_dp_port_allocated_bandwidth(in);
1029                 if (ret < 0)
1030                         return ret;
1031                 allocated_bw = ret;
1032
1033                 ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw);
1034                 if (ret < 0)
1035                         return ret;
1036                 if (allocated_bw == max_bw)
1037                         allocated_bw = ret;
1038
1039                 if (tb_port_path_direction_downstream(in, out)) {
1040                         *allocated_up = 0;
1041                         *allocated_down = allocated_bw;
1042                 } else {
1043                         *allocated_up = allocated_bw;
1044                         *allocated_down = 0;
1045                 }
1046                 return 0;
1047         }
1048
1049         return tunnel->consumed_bandwidth(tunnel, allocated_up,
1050                                           allocated_down);
1051 }
1052
1053 static int tb_dp_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,
1054                                  int *alloc_down)
1055 {
1056         struct tb_port *out = tunnel->dst_port;
1057         struct tb_port *in = tunnel->src_port;
1058         int max_bw, ret, tmp;
1059
1060         if (!usb4_dp_port_bandwidth_mode_enabled(in))
1061                 return -EOPNOTSUPP;
1062
1063         ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw);
1064         if (ret < 0)
1065                 return ret;
1066
1067         if (tb_port_path_direction_downstream(in, out)) {
1068                 tmp = min(*alloc_down, max_bw);
1069                 ret = usb4_dp_port_allocate_bandwidth(in, tmp);
1070                 if (ret)
1071                         return ret;
1072                 *alloc_down = tmp;
1073                 *alloc_up = 0;
1074         } else {
1075                 tmp = min(*alloc_up, max_bw);
1076                 ret = usb4_dp_port_allocate_bandwidth(in, tmp);
1077                 if (ret)
1078                         return ret;
1079                 *alloc_down = 0;
1080                 *alloc_up = tmp;
1081         }
1082
1083         /* Now we can use BW mode registers to figure out the bandwidth */
1084         /* TODO: need to handle discovery too */
1085         tunnel->bw_mode = true;
1086         return 0;
1087 }
1088
1089 static int tb_dp_wait_dprx(struct tb_tunnel *tunnel, int timeout_msec)
1090 {
1091         ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
1092         struct tb_port *in = tunnel->src_port;
1093
1094         /*
1095          * Wait for DPRX done. Normally it should be already set for
1096          * active tunnel.
1097          */
1098         do {
1099                 u32 val;
1100                 int ret;
1101
1102                 ret = tb_port_read(in, &val, TB_CFG_PORT,
1103                                    in->cap_adap + DP_COMMON_CAP, 1);
1104                 if (ret)
1105                         return ret;
1106
1107                 if (val & DP_COMMON_CAP_DPRX_DONE) {
1108                         tb_tunnel_dbg(tunnel, "DPRX read done\n");
1109                         return 0;
1110                 }
1111                 usleep_range(100, 150);
1112         } while (ktime_before(ktime_get(), timeout));
1113
1114         tb_tunnel_dbg(tunnel, "DPRX read timeout\n");
1115         return -ETIMEDOUT;
1116 }
1117
1118 /* Read cap from tunnel DP IN */
1119 static int tb_dp_read_cap(struct tb_tunnel *tunnel, unsigned int cap, u32 *rate,
1120                           u32 *lanes)
1121 {
1122         struct tb_port *in = tunnel->src_port;
1123         u32 val;
1124         int ret;
1125
1126         switch (cap) {
1127         case DP_LOCAL_CAP:
1128         case DP_REMOTE_CAP:
1129         case DP_COMMON_CAP:
1130                 break;
1131
1132         default:
1133                 tb_tunnel_WARN(tunnel, "invalid capability index %#x\n", cap);
1134                 return -EINVAL;
1135         }
1136
1137         /*
1138          * Read from the copied remote cap so that we take into account
1139          * if capabilities were reduced during exchange.
1140          */
1141         ret = tb_port_read(in, &val, TB_CFG_PORT, in->cap_adap + cap, 1);
1142         if (ret)
1143                 return ret;
1144
1145         *rate = tb_dp_cap_get_rate(val);
1146         *lanes = tb_dp_cap_get_lanes(val);
1147         return 0;
1148 }
1149
1150 static int tb_dp_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,
1151                                    int *max_down)
1152 {
1153         struct tb_port *in = tunnel->src_port;
1154         int ret;
1155
1156         if (!usb4_dp_port_bandwidth_mode_enabled(in))
1157                 return -EOPNOTSUPP;
1158
1159         ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, NULL);
1160         if (ret < 0)
1161                 return ret;
1162
1163         if (tb_port_path_direction_downstream(in, tunnel->dst_port)) {
1164                 *max_up = 0;
1165                 *max_down = ret;
1166         } else {
1167                 *max_up = ret;
1168                 *max_down = 0;
1169         }
1170
1171         return 0;
1172 }
1173
1174 static int tb_dp_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
1175                                     int *consumed_down)
1176 {
1177         struct tb_port *in = tunnel->src_port;
1178         const struct tb_switch *sw = in->sw;
1179         u32 rate = 0, lanes = 0;
1180         int ret;
1181
1182         if (tb_dp_is_usb4(sw)) {
1183                 /*
1184                  * On USB4 routers check if the bandwidth allocation
1185                  * mode is enabled first and then read the bandwidth
1186                  * through those registers.
1187                  */
1188                 ret = tb_dp_bandwidth_mode_consumed_bandwidth(tunnel, consumed_up,
1189                                                               consumed_down);
1190                 if (ret < 0) {
1191                         if (ret != -EOPNOTSUPP)
1192                                 return ret;
1193                 } else if (!ret) {
1194                         return 0;
1195                 }
1196                 /*
1197                  * Then see if the DPRX negotiation is ready and if yes
1198                  * return that bandwidth (it may be smaller than the
1199                  * reduced one). According to VESA spec, the DPRX
1200                  * negotiation shall compete in 5 seconds after tunnel
1201                  * established. We give it 100ms extra just in case.
1202                  */
1203                 ret = tb_dp_wait_dprx(tunnel, 5100);
1204                 if (ret)
1205                         return ret;
1206                 ret = tb_dp_read_cap(tunnel, DP_COMMON_CAP, &rate, &lanes);
1207                 if (ret)
1208                         return ret;
1209         } else if (sw->generation >= 2) {
1210                 ret = tb_dp_read_cap(tunnel, DP_REMOTE_CAP, &rate, &lanes);
1211                 if (ret)
1212                         return ret;
1213         } else {
1214                 /* No bandwidth management for legacy devices  */
1215                 *consumed_up = 0;
1216                 *consumed_down = 0;
1217                 return 0;
1218         }
1219
1220         if (tb_port_path_direction_downstream(in, tunnel->dst_port)) {
1221                 *consumed_up = 0;
1222                 *consumed_down = tb_dp_bandwidth(rate, lanes);
1223         } else {
1224                 *consumed_up = tb_dp_bandwidth(rate, lanes);
1225                 *consumed_down = 0;
1226         }
1227
1228         return 0;
1229 }
1230
1231 static void tb_dp_init_aux_credits(struct tb_path_hop *hop)
1232 {
1233         struct tb_port *port = hop->in_port;
1234         struct tb_switch *sw = port->sw;
1235
1236         if (tb_port_use_credit_allocation(port))
1237                 hop->initial_credits = sw->min_dp_aux_credits;
1238         else
1239                 hop->initial_credits = 1;
1240 }
1241
1242 static void tb_dp_init_aux_path(struct tb_path *path, bool pm_support)
1243 {
1244         struct tb_path_hop *hop;
1245
1246         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1247         path->egress_shared_buffer = TB_PATH_NONE;
1248         path->ingress_fc_enable = TB_PATH_ALL;
1249         path->ingress_shared_buffer = TB_PATH_NONE;
1250         path->priority = TB_DP_AUX_PRIORITY;
1251         path->weight = TB_DP_AUX_WEIGHT;
1252
1253         tb_path_for_each_hop(path, hop) {
1254                 tb_dp_init_aux_credits(hop);
1255                 if (pm_support)
1256                         tb_init_pm_support(hop);
1257         }
1258 }
1259
1260 static int tb_dp_init_video_credits(struct tb_path_hop *hop)
1261 {
1262         struct tb_port *port = hop->in_port;
1263         struct tb_switch *sw = port->sw;
1264
1265         if (tb_port_use_credit_allocation(port)) {
1266                 unsigned int nfc_credits;
1267                 size_t max_dp_streams;
1268
1269                 tb_available_credits(port, &max_dp_streams);
1270                 /*
1271                  * Read the number of currently allocated NFC credits
1272                  * from the lane adapter. Since we only use them for DP
1273                  * tunneling we can use that to figure out how many DP
1274                  * tunnels already go through the lane adapter.
1275                  */
1276                 nfc_credits = port->config.nfc_credits &
1277                                 ADP_CS_4_NFC_BUFFERS_MASK;
1278                 if (nfc_credits / sw->min_dp_main_credits > max_dp_streams)
1279                         return -ENOSPC;
1280
1281                 hop->nfc_credits = sw->min_dp_main_credits;
1282         } else {
1283                 hop->nfc_credits = min(port->total_credits - 2, 12U);
1284         }
1285
1286         return 0;
1287 }
1288
1289 static int tb_dp_init_video_path(struct tb_path *path, bool pm_support)
1290 {
1291         struct tb_path_hop *hop;
1292
1293         path->egress_fc_enable = TB_PATH_NONE;
1294         path->egress_shared_buffer = TB_PATH_NONE;
1295         path->ingress_fc_enable = TB_PATH_NONE;
1296         path->ingress_shared_buffer = TB_PATH_NONE;
1297         path->priority = TB_DP_VIDEO_PRIORITY;
1298         path->weight = TB_DP_VIDEO_WEIGHT;
1299
1300         tb_path_for_each_hop(path, hop) {
1301                 int ret;
1302
1303                 ret = tb_dp_init_video_credits(hop);
1304                 if (ret)
1305                         return ret;
1306                 if (pm_support)
1307                         tb_init_pm_support(hop);
1308         }
1309
1310         return 0;
1311 }
1312
1313 static void tb_dp_dump(struct tb_tunnel *tunnel)
1314 {
1315         struct tb_port *in, *out;
1316         u32 dp_cap, rate, lanes;
1317
1318         in = tunnel->src_port;
1319         out = tunnel->dst_port;
1320
1321         if (tb_port_read(in, &dp_cap, TB_CFG_PORT,
1322                          in->cap_adap + DP_LOCAL_CAP, 1))
1323                 return;
1324
1325         rate = tb_dp_cap_get_rate(dp_cap);
1326         lanes = tb_dp_cap_get_lanes(dp_cap);
1327
1328         tb_tunnel_dbg(tunnel,
1329                       "DP IN maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
1330                       rate, lanes, tb_dp_bandwidth(rate, lanes));
1331
1332         if (tb_port_read(out, &dp_cap, TB_CFG_PORT,
1333                          out->cap_adap + DP_LOCAL_CAP, 1))
1334                 return;
1335
1336         rate = tb_dp_cap_get_rate(dp_cap);
1337         lanes = tb_dp_cap_get_lanes(dp_cap);
1338
1339         tb_tunnel_dbg(tunnel,
1340                       "DP OUT maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
1341                       rate, lanes, tb_dp_bandwidth(rate, lanes));
1342
1343         if (tb_port_read(in, &dp_cap, TB_CFG_PORT,
1344                          in->cap_adap + DP_REMOTE_CAP, 1))
1345                 return;
1346
1347         rate = tb_dp_cap_get_rate(dp_cap);
1348         lanes = tb_dp_cap_get_lanes(dp_cap);
1349
1350         tb_tunnel_dbg(tunnel, "reduced bandwidth %u Mb/s x%u = %u Mb/s\n",
1351                       rate, lanes, tb_dp_bandwidth(rate, lanes));
1352 }
1353
1354 /**
1355  * tb_tunnel_discover_dp() - Discover existing Display Port tunnels
1356  * @tb: Pointer to the domain structure
1357  * @in: DP in adapter
1358  * @alloc_hopid: Allocate HopIDs from visited ports
1359  *
1360  * If @in adapter is active, follows the tunnel to the DP out adapter
1361  * and back. Returns the discovered tunnel or %NULL if there was no
1362  * tunnel.
1363  *
1364  * Return: DP tunnel or %NULL if no tunnel found.
1365  */
1366 struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in,
1367                                         bool alloc_hopid)
1368 {
1369         struct tb_tunnel *tunnel;
1370         struct tb_port *port;
1371         struct tb_path *path;
1372
1373         if (!tb_dp_port_is_enabled(in))
1374                 return NULL;
1375
1376         tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
1377         if (!tunnel)
1378                 return NULL;
1379
1380         tunnel->init = tb_dp_init;
1381         tunnel->deinit = tb_dp_deinit;
1382         tunnel->activate = tb_dp_activate;
1383         tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;
1384         tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;
1385         tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;
1386         tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
1387         tunnel->src_port = in;
1388
1389         path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1,
1390                                 &tunnel->dst_port, "Video", alloc_hopid);
1391         if (!path) {
1392                 /* Just disable the DP IN port */
1393                 tb_dp_port_enable(in, false);
1394                 goto err_free;
1395         }
1396         tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;
1397         if (tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT], false))
1398                 goto err_free;
1399
1400         path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX",
1401                                 alloc_hopid);
1402         if (!path)
1403                 goto err_deactivate;
1404         tunnel->paths[TB_DP_AUX_PATH_OUT] = path;
1405         tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT], false);
1406
1407         path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID,
1408                                 &port, "AUX RX", alloc_hopid);
1409         if (!path)
1410                 goto err_deactivate;
1411         tunnel->paths[TB_DP_AUX_PATH_IN] = path;
1412         tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN], false);
1413
1414         /* Validate that the tunnel is complete */
1415         if (!tb_port_is_dpout(tunnel->dst_port)) {
1416                 tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");
1417                 goto err_deactivate;
1418         }
1419
1420         if (!tb_dp_port_is_enabled(tunnel->dst_port))
1421                 goto err_deactivate;
1422
1423         if (!tb_dp_port_hpd_is_active(tunnel->dst_port))
1424                 goto err_deactivate;
1425
1426         if (port != tunnel->src_port) {
1427                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
1428                 goto err_deactivate;
1429         }
1430
1431         tb_dp_dump(tunnel);
1432
1433         tb_tunnel_dbg(tunnel, "discovered\n");
1434         return tunnel;
1435
1436 err_deactivate:
1437         tb_tunnel_deactivate(tunnel);
1438 err_free:
1439         tb_tunnel_free(tunnel);
1440
1441         return NULL;
1442 }
1443
1444 /**
1445  * tb_tunnel_alloc_dp() - allocate a Display Port tunnel
1446  * @tb: Pointer to the domain structure
1447  * @in: DP in adapter port
1448  * @out: DP out adapter port
1449  * @link_nr: Preferred lane adapter when the link is not bonded
1450  * @max_up: Maximum available upstream bandwidth for the DP tunnel (%0
1451  *          if not limited)
1452  * @max_down: Maximum available downstream bandwidth for the DP tunnel
1453  *            (%0 if not limited)
1454  *
1455  * Allocates a tunnel between @in and @out that is capable of tunneling
1456  * Display Port traffic.
1457  *
1458  * Return: Returns a tb_tunnel on success or NULL on failure.
1459  */
1460 struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
1461                                      struct tb_port *out, int link_nr,
1462                                      int max_up, int max_down)
1463 {
1464         struct tb_tunnel *tunnel;
1465         struct tb_path **paths;
1466         struct tb_path *path;
1467         bool pm_support;
1468
1469         if (WARN_ON(!in->cap_adap || !out->cap_adap))
1470                 return NULL;
1471
1472         tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
1473         if (!tunnel)
1474                 return NULL;
1475
1476         tunnel->init = tb_dp_init;
1477         tunnel->deinit = tb_dp_deinit;
1478         tunnel->activate = tb_dp_activate;
1479         tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;
1480         tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;
1481         tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;
1482         tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
1483         tunnel->src_port = in;
1484         tunnel->dst_port = out;
1485         tunnel->max_up = max_up;
1486         tunnel->max_down = max_down;
1487
1488         paths = tunnel->paths;
1489         pm_support = usb4_switch_version(in->sw) >= 2;
1490
1491         path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,
1492                              link_nr, "Video");
1493         if (!path)
1494                 goto err_free;
1495         tb_dp_init_video_path(path, pm_support);
1496         paths[TB_DP_VIDEO_PATH_OUT] = path;
1497
1498         path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
1499                              TB_DP_AUX_TX_HOPID, link_nr, "AUX TX");
1500         if (!path)
1501                 goto err_free;
1502         tb_dp_init_aux_path(path, pm_support);
1503         paths[TB_DP_AUX_PATH_OUT] = path;
1504
1505         path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,
1506                              TB_DP_AUX_RX_HOPID, link_nr, "AUX RX");
1507         if (!path)
1508                 goto err_free;
1509         tb_dp_init_aux_path(path, pm_support);
1510         paths[TB_DP_AUX_PATH_IN] = path;
1511
1512         return tunnel;
1513
1514 err_free:
1515         tb_tunnel_free(tunnel);
1516         return NULL;
1517 }
1518
1519 static unsigned int tb_dma_available_credits(const struct tb_port *port)
1520 {
1521         const struct tb_switch *sw = port->sw;
1522         int credits;
1523
1524         credits = tb_available_credits(port, NULL);
1525         if (tb_acpi_may_tunnel_pcie())
1526                 credits -= sw->max_pcie_credits;
1527         credits -= port->dma_credits;
1528
1529         return credits > 0 ? credits : 0;
1530 }
1531
1532 static int tb_dma_reserve_credits(struct tb_path_hop *hop, unsigned int credits)
1533 {
1534         struct tb_port *port = hop->in_port;
1535
1536         if (tb_port_use_credit_allocation(port)) {
1537                 unsigned int available = tb_dma_available_credits(port);
1538
1539                 /*
1540                  * Need to have at least TB_MIN_DMA_CREDITS, otherwise
1541                  * DMA path cannot be established.
1542                  */
1543                 if (available < TB_MIN_DMA_CREDITS)
1544                         return -ENOSPC;
1545
1546                 while (credits > available)
1547                         credits--;
1548
1549                 tb_port_dbg(port, "reserving %u credits for DMA path\n",
1550                             credits);
1551
1552                 port->dma_credits += credits;
1553         } else {
1554                 if (tb_port_is_null(port))
1555                         credits = port->bonded ? 14 : 6;
1556                 else
1557                         credits = min(port->total_credits, credits);
1558         }
1559
1560         hop->initial_credits = credits;
1561         return 0;
1562 }
1563
1564 /* Path from lane adapter to NHI */
1565 static int tb_dma_init_rx_path(struct tb_path *path, unsigned int credits)
1566 {
1567         struct tb_path_hop *hop;
1568         unsigned int i, tmp;
1569
1570         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1571         path->ingress_fc_enable = TB_PATH_ALL;
1572         path->egress_shared_buffer = TB_PATH_NONE;
1573         path->ingress_shared_buffer = TB_PATH_NONE;
1574         path->priority = TB_DMA_PRIORITY;
1575         path->weight = TB_DMA_WEIGHT;
1576         path->clear_fc = true;
1577
1578         /*
1579          * First lane adapter is the one connected to the remote host.
1580          * We don't tunnel other traffic over this link so can use all
1581          * the credits (except the ones reserved for control traffic).
1582          */
1583         hop = &path->hops[0];
1584         tmp = min(tb_usable_credits(hop->in_port), credits);
1585         hop->initial_credits = tmp;
1586         hop->in_port->dma_credits += tmp;
1587
1588         for (i = 1; i < path->path_length; i++) {
1589                 int ret;
1590
1591                 ret = tb_dma_reserve_credits(&path->hops[i], credits);
1592                 if (ret)
1593                         return ret;
1594         }
1595
1596         return 0;
1597 }
1598
1599 /* Path from NHI to lane adapter */
1600 static int tb_dma_init_tx_path(struct tb_path *path, unsigned int credits)
1601 {
1602         struct tb_path_hop *hop;
1603
1604         path->egress_fc_enable = TB_PATH_ALL;
1605         path->ingress_fc_enable = TB_PATH_ALL;
1606         path->egress_shared_buffer = TB_PATH_NONE;
1607         path->ingress_shared_buffer = TB_PATH_NONE;
1608         path->priority = TB_DMA_PRIORITY;
1609         path->weight = TB_DMA_WEIGHT;
1610         path->clear_fc = true;
1611
1612         tb_path_for_each_hop(path, hop) {
1613                 int ret;
1614
1615                 ret = tb_dma_reserve_credits(hop, credits);
1616                 if (ret)
1617                         return ret;
1618         }
1619
1620         return 0;
1621 }
1622
1623 static void tb_dma_release_credits(struct tb_path_hop *hop)
1624 {
1625         struct tb_port *port = hop->in_port;
1626
1627         if (tb_port_use_credit_allocation(port)) {
1628                 port->dma_credits -= hop->initial_credits;
1629
1630                 tb_port_dbg(port, "released %u DMA path credits\n",
1631                             hop->initial_credits);
1632         }
1633 }
1634
1635 static void tb_dma_deinit_path(struct tb_path *path)
1636 {
1637         struct tb_path_hop *hop;
1638
1639         tb_path_for_each_hop(path, hop)
1640                 tb_dma_release_credits(hop);
1641 }
1642
1643 static void tb_dma_deinit(struct tb_tunnel *tunnel)
1644 {
1645         int i;
1646
1647         for (i = 0; i < tunnel->npaths; i++) {
1648                 if (!tunnel->paths[i])
1649                         continue;
1650                 tb_dma_deinit_path(tunnel->paths[i]);
1651         }
1652 }
1653
1654 /**
1655  * tb_tunnel_alloc_dma() - allocate a DMA tunnel
1656  * @tb: Pointer to the domain structure
1657  * @nhi: Host controller port
1658  * @dst: Destination null port which the other domain is connected to
1659  * @transmit_path: HopID used for transmitting packets
1660  * @transmit_ring: NHI ring number used to send packets towards the
1661  *                 other domain. Set to %-1 if TX path is not needed.
1662  * @receive_path: HopID used for receiving packets
1663  * @receive_ring: NHI ring number used to receive packets from the
1664  *                other domain. Set to %-1 if RX path is not needed.
1665  *
1666  * Return: Returns a tb_tunnel on success or NULL on failure.
1667  */
1668 struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
1669                                       struct tb_port *dst, int transmit_path,
1670                                       int transmit_ring, int receive_path,
1671                                       int receive_ring)
1672 {
1673         struct tb_tunnel *tunnel;
1674         size_t npaths = 0, i = 0;
1675         struct tb_path *path;
1676         int credits;
1677
1678         /* Ring 0 is reserved for control channel */
1679         if (WARN_ON(!receive_ring || !transmit_ring))
1680                 return NULL;
1681
1682         if (receive_ring > 0)
1683                 npaths++;
1684         if (transmit_ring > 0)
1685                 npaths++;
1686
1687         if (WARN_ON(!npaths))
1688                 return NULL;
1689
1690         tunnel = tb_tunnel_alloc(tb, npaths, TB_TUNNEL_DMA);
1691         if (!tunnel)
1692                 return NULL;
1693
1694         tunnel->src_port = nhi;
1695         tunnel->dst_port = dst;
1696         tunnel->deinit = tb_dma_deinit;
1697
1698         credits = min_not_zero(dma_credits, nhi->sw->max_dma_credits);
1699
1700         if (receive_ring > 0) {
1701                 path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0,
1702                                      "DMA RX");
1703                 if (!path)
1704                         goto err_free;
1705                 tunnel->paths[i++] = path;
1706                 if (tb_dma_init_rx_path(path, credits)) {
1707                         tb_tunnel_dbg(tunnel, "not enough buffers for RX path\n");
1708                         goto err_free;
1709                 }
1710         }
1711
1712         if (transmit_ring > 0) {
1713                 path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0,
1714                                      "DMA TX");
1715                 if (!path)
1716                         goto err_free;
1717                 tunnel->paths[i++] = path;
1718                 if (tb_dma_init_tx_path(path, credits)) {
1719                         tb_tunnel_dbg(tunnel, "not enough buffers for TX path\n");
1720                         goto err_free;
1721                 }
1722         }
1723
1724         return tunnel;
1725
1726 err_free:
1727         tb_tunnel_free(tunnel);
1728         return NULL;
1729 }
1730
1731 /**
1732  * tb_tunnel_match_dma() - Match DMA tunnel
1733  * @tunnel: Tunnel to match
1734  * @transmit_path: HopID used for transmitting packets. Pass %-1 to ignore.
1735  * @transmit_ring: NHI ring number used to send packets towards the
1736  *                 other domain. Pass %-1 to ignore.
1737  * @receive_path: HopID used for receiving packets. Pass %-1 to ignore.
1738  * @receive_ring: NHI ring number used to receive packets from the
1739  *                other domain. Pass %-1 to ignore.
1740  *
1741  * This function can be used to match specific DMA tunnel, if there are
1742  * multiple DMA tunnels going through the same XDomain connection.
1743  * Returns true if there is match and false otherwise.
1744  */
1745 bool tb_tunnel_match_dma(const struct tb_tunnel *tunnel, int transmit_path,
1746                          int transmit_ring, int receive_path, int receive_ring)
1747 {
1748         const struct tb_path *tx_path = NULL, *rx_path = NULL;
1749         int i;
1750
1751         if (!receive_ring || !transmit_ring)
1752                 return false;
1753
1754         for (i = 0; i < tunnel->npaths; i++) {
1755                 const struct tb_path *path = tunnel->paths[i];
1756
1757                 if (!path)
1758                         continue;
1759
1760                 if (tb_port_is_nhi(path->hops[0].in_port))
1761                         tx_path = path;
1762                 else if (tb_port_is_nhi(path->hops[path->path_length - 1].out_port))
1763                         rx_path = path;
1764         }
1765
1766         if (transmit_ring > 0 || transmit_path > 0) {
1767                 if (!tx_path)
1768                         return false;
1769                 if (transmit_ring > 0 &&
1770                     (tx_path->hops[0].in_hop_index != transmit_ring))
1771                         return false;
1772                 if (transmit_path > 0 &&
1773                     (tx_path->hops[tx_path->path_length - 1].next_hop_index != transmit_path))
1774                         return false;
1775         }
1776
1777         if (receive_ring > 0 || receive_path > 0) {
1778                 if (!rx_path)
1779                         return false;
1780                 if (receive_path > 0 &&
1781                     (rx_path->hops[0].in_hop_index != receive_path))
1782                         return false;
1783                 if (receive_ring > 0 &&
1784                     (rx_path->hops[rx_path->path_length - 1].next_hop_index != receive_ring))
1785                         return false;
1786         }
1787
1788         return true;
1789 }
1790
1791 static int tb_usb3_max_link_rate(struct tb_port *up, struct tb_port *down)
1792 {
1793         int ret, up_max_rate, down_max_rate;
1794
1795         ret = usb4_usb3_port_max_link_rate(up);
1796         if (ret < 0)
1797                 return ret;
1798         up_max_rate = ret;
1799
1800         ret = usb4_usb3_port_max_link_rate(down);
1801         if (ret < 0)
1802                 return ret;
1803         down_max_rate = ret;
1804
1805         return min(up_max_rate, down_max_rate);
1806 }
1807
1808 static int tb_usb3_init(struct tb_tunnel *tunnel)
1809 {
1810         tb_tunnel_dbg(tunnel, "allocating initial bandwidth %d/%d Mb/s\n",
1811                       tunnel->allocated_up, tunnel->allocated_down);
1812
1813         return usb4_usb3_port_allocate_bandwidth(tunnel->src_port,
1814                                                  &tunnel->allocated_up,
1815                                                  &tunnel->allocated_down);
1816 }
1817
1818 static int tb_usb3_activate(struct tb_tunnel *tunnel, bool activate)
1819 {
1820         int res;
1821
1822         res = tb_usb3_port_enable(tunnel->src_port, activate);
1823         if (res)
1824                 return res;
1825
1826         if (tb_port_is_usb3_up(tunnel->dst_port))
1827                 return tb_usb3_port_enable(tunnel->dst_port, activate);
1828
1829         return 0;
1830 }
1831
1832 static int tb_usb3_consumed_bandwidth(struct tb_tunnel *tunnel,
1833                 int *consumed_up, int *consumed_down)
1834 {
1835         struct tb_port *port = tb_upstream_port(tunnel->dst_port->sw);
1836         int pcie_weight = tb_acpi_may_tunnel_pcie() ? TB_PCI_WEIGHT : 0;
1837
1838         /*
1839          * PCIe tunneling, if enabled, affects the USB3 bandwidth so
1840          * take that it into account here.
1841          */
1842         *consumed_up = tunnel->allocated_up *
1843                 (TB_USB3_WEIGHT + pcie_weight) / TB_USB3_WEIGHT;
1844         *consumed_down = tunnel->allocated_down *
1845                 (TB_USB3_WEIGHT + pcie_weight) / TB_USB3_WEIGHT;
1846
1847         if (tb_port_get_link_generation(port) >= 4) {
1848                 *consumed_up = max(*consumed_up, USB4_V2_USB3_MIN_BANDWIDTH);
1849                 *consumed_down = max(*consumed_down, USB4_V2_USB3_MIN_BANDWIDTH);
1850         }
1851
1852         return 0;
1853 }
1854
1855 static int tb_usb3_release_unused_bandwidth(struct tb_tunnel *tunnel)
1856 {
1857         int ret;
1858
1859         ret = usb4_usb3_port_release_bandwidth(tunnel->src_port,
1860                                                &tunnel->allocated_up,
1861                                                &tunnel->allocated_down);
1862         if (ret)
1863                 return ret;
1864
1865         tb_tunnel_dbg(tunnel, "decreased bandwidth allocation to %d/%d Mb/s\n",
1866                       tunnel->allocated_up, tunnel->allocated_down);
1867         return 0;
1868 }
1869
1870 static void tb_usb3_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
1871                                                 int *available_up,
1872                                                 int *available_down)
1873 {
1874         int ret, max_rate, allocate_up, allocate_down;
1875
1876         ret = tb_usb3_max_link_rate(tunnel->dst_port, tunnel->src_port);
1877         if (ret < 0) {
1878                 tb_tunnel_warn(tunnel, "failed to read maximum link rate\n");
1879                 return;
1880         }
1881
1882         /*
1883          * 90% of the max rate can be allocated for isochronous
1884          * transfers.
1885          */
1886         max_rate = ret * 90 / 100;
1887
1888         /* No need to reclaim if already at maximum */
1889         if (tunnel->allocated_up >= max_rate &&
1890             tunnel->allocated_down >= max_rate)
1891                 return;
1892
1893         /* Don't go lower than what is already allocated */
1894         allocate_up = min(max_rate, *available_up);
1895         if (allocate_up < tunnel->allocated_up)
1896                 allocate_up = tunnel->allocated_up;
1897
1898         allocate_down = min(max_rate, *available_down);
1899         if (allocate_down < tunnel->allocated_down)
1900                 allocate_down = tunnel->allocated_down;
1901
1902         /* If no changes no need to do more */
1903         if (allocate_up == tunnel->allocated_up &&
1904             allocate_down == tunnel->allocated_down)
1905                 return;
1906
1907         ret = usb4_usb3_port_allocate_bandwidth(tunnel->src_port, &allocate_up,
1908                                                 &allocate_down);
1909         if (ret) {
1910                 tb_tunnel_info(tunnel, "failed to allocate bandwidth\n");
1911                 return;
1912         }
1913
1914         tunnel->allocated_up = allocate_up;
1915         *available_up -= tunnel->allocated_up;
1916
1917         tunnel->allocated_down = allocate_down;
1918         *available_down -= tunnel->allocated_down;
1919
1920         tb_tunnel_dbg(tunnel, "increased bandwidth allocation to %d/%d Mb/s\n",
1921                       tunnel->allocated_up, tunnel->allocated_down);
1922 }
1923
1924 static void tb_usb3_init_credits(struct tb_path_hop *hop)
1925 {
1926         struct tb_port *port = hop->in_port;
1927         struct tb_switch *sw = port->sw;
1928         unsigned int credits;
1929
1930         if (tb_port_use_credit_allocation(port)) {
1931                 credits = sw->max_usb3_credits;
1932         } else {
1933                 if (tb_port_is_null(port))
1934                         credits = port->bonded ? 32 : 16;
1935                 else
1936                         credits = 7;
1937         }
1938
1939         hop->initial_credits = credits;
1940 }
1941
1942 static void tb_usb3_init_path(struct tb_path *path)
1943 {
1944         struct tb_path_hop *hop;
1945
1946         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1947         path->egress_shared_buffer = TB_PATH_NONE;
1948         path->ingress_fc_enable = TB_PATH_ALL;
1949         path->ingress_shared_buffer = TB_PATH_NONE;
1950         path->priority = TB_USB3_PRIORITY;
1951         path->weight = TB_USB3_WEIGHT;
1952         path->drop_packages = 0;
1953
1954         tb_path_for_each_hop(path, hop)
1955                 tb_usb3_init_credits(hop);
1956 }
1957
1958 /**
1959  * tb_tunnel_discover_usb3() - Discover existing USB3 tunnels
1960  * @tb: Pointer to the domain structure
1961  * @down: USB3 downstream adapter
1962  * @alloc_hopid: Allocate HopIDs from visited ports
1963  *
1964  * If @down adapter is active, follows the tunnel to the USB3 upstream
1965  * adapter and back. Returns the discovered tunnel or %NULL if there was
1966  * no tunnel.
1967  */
1968 struct tb_tunnel *tb_tunnel_discover_usb3(struct tb *tb, struct tb_port *down,
1969                                           bool alloc_hopid)
1970 {
1971         struct tb_tunnel *tunnel;
1972         struct tb_path *path;
1973
1974         if (!tb_usb3_port_is_enabled(down))
1975                 return NULL;
1976
1977         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
1978         if (!tunnel)
1979                 return NULL;
1980
1981         tunnel->activate = tb_usb3_activate;
1982         tunnel->src_port = down;
1983
1984         /*
1985          * Discover both paths even if they are not complete. We will
1986          * clean them up by calling tb_tunnel_deactivate() below in that
1987          * case.
1988          */
1989         path = tb_path_discover(down, TB_USB3_HOPID, NULL, -1,
1990                                 &tunnel->dst_port, "USB3 Down", alloc_hopid);
1991         if (!path) {
1992                 /* Just disable the downstream port */
1993                 tb_usb3_port_enable(down, false);
1994                 goto err_free;
1995         }
1996         tunnel->paths[TB_USB3_PATH_DOWN] = path;
1997         tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_DOWN]);
1998
1999         path = tb_path_discover(tunnel->dst_port, -1, down, TB_USB3_HOPID, NULL,
2000                                 "USB3 Up", alloc_hopid);
2001         if (!path)
2002                 goto err_deactivate;
2003         tunnel->paths[TB_USB3_PATH_UP] = path;
2004         tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_UP]);
2005
2006         /* Validate that the tunnel is complete */
2007         if (!tb_port_is_usb3_up(tunnel->dst_port)) {
2008                 tb_port_warn(tunnel->dst_port,
2009                              "path does not end on an USB3 adapter, cleaning up\n");
2010                 goto err_deactivate;
2011         }
2012
2013         if (down != tunnel->src_port) {
2014                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
2015                 goto err_deactivate;
2016         }
2017
2018         if (!tb_usb3_port_is_enabled(tunnel->dst_port)) {
2019                 tb_tunnel_warn(tunnel,
2020                                "tunnel is not fully activated, cleaning up\n");
2021                 goto err_deactivate;
2022         }
2023
2024         if (!tb_route(down->sw)) {
2025                 int ret;
2026
2027                 /*
2028                  * Read the initial bandwidth allocation for the first
2029                  * hop tunnel.
2030                  */
2031                 ret = usb4_usb3_port_allocated_bandwidth(down,
2032                         &tunnel->allocated_up, &tunnel->allocated_down);
2033                 if (ret)
2034                         goto err_deactivate;
2035
2036                 tb_tunnel_dbg(tunnel, "currently allocated bandwidth %d/%d Mb/s\n",
2037                               tunnel->allocated_up, tunnel->allocated_down);
2038
2039                 tunnel->init = tb_usb3_init;
2040                 tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
2041                 tunnel->release_unused_bandwidth =
2042                         tb_usb3_release_unused_bandwidth;
2043                 tunnel->reclaim_available_bandwidth =
2044                         tb_usb3_reclaim_available_bandwidth;
2045         }
2046
2047         tb_tunnel_dbg(tunnel, "discovered\n");
2048         return tunnel;
2049
2050 err_deactivate:
2051         tb_tunnel_deactivate(tunnel);
2052 err_free:
2053         tb_tunnel_free(tunnel);
2054
2055         return NULL;
2056 }
2057
2058 /**
2059  * tb_tunnel_alloc_usb3() - allocate a USB3 tunnel
2060  * @tb: Pointer to the domain structure
2061  * @up: USB3 upstream adapter port
2062  * @down: USB3 downstream adapter port
2063  * @max_up: Maximum available upstream bandwidth for the USB3 tunnel (%0
2064  *          if not limited).
2065  * @max_down: Maximum available downstream bandwidth for the USB3 tunnel
2066  *            (%0 if not limited).
2067  *
2068  * Allocate an USB3 tunnel. The ports must be of type @TB_TYPE_USB3_UP and
2069  * @TB_TYPE_USB3_DOWN.
2070  *
2071  * Return: Returns a tb_tunnel on success or %NULL on failure.
2072  */
2073 struct tb_tunnel *tb_tunnel_alloc_usb3(struct tb *tb, struct tb_port *up,
2074                                        struct tb_port *down, int max_up,
2075                                        int max_down)
2076 {
2077         struct tb_tunnel *tunnel;
2078         struct tb_path *path;
2079         int max_rate = 0;
2080
2081         /*
2082          * Check that we have enough bandwidth available for the new
2083          * USB3 tunnel.
2084          */
2085         if (max_up > 0 || max_down > 0) {
2086                 max_rate = tb_usb3_max_link_rate(down, up);
2087                 if (max_rate < 0)
2088                         return NULL;
2089
2090                 /* Only 90% can be allocated for USB3 isochronous transfers */
2091                 max_rate = max_rate * 90 / 100;
2092                 tb_port_dbg(up, "required bandwidth for USB3 tunnel %d Mb/s\n",
2093                             max_rate);
2094
2095                 if (max_rate > max_up || max_rate > max_down) {
2096                         tb_port_warn(up, "not enough bandwidth for USB3 tunnel\n");
2097                         return NULL;
2098                 }
2099         }
2100
2101         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
2102         if (!tunnel)
2103                 return NULL;
2104
2105         tunnel->activate = tb_usb3_activate;
2106         tunnel->src_port = down;
2107         tunnel->dst_port = up;
2108         tunnel->max_up = max_up;
2109         tunnel->max_down = max_down;
2110
2111         path = tb_path_alloc(tb, down, TB_USB3_HOPID, up, TB_USB3_HOPID, 0,
2112                              "USB3 Down");
2113         if (!path) {
2114                 tb_tunnel_free(tunnel);
2115                 return NULL;
2116         }
2117         tb_usb3_init_path(path);
2118         tunnel->paths[TB_USB3_PATH_DOWN] = path;
2119
2120         path = tb_path_alloc(tb, up, TB_USB3_HOPID, down, TB_USB3_HOPID, 0,
2121                              "USB3 Up");
2122         if (!path) {
2123                 tb_tunnel_free(tunnel);
2124                 return NULL;
2125         }
2126         tb_usb3_init_path(path);
2127         tunnel->paths[TB_USB3_PATH_UP] = path;
2128
2129         if (!tb_route(down->sw)) {
2130                 tunnel->allocated_up = max_rate;
2131                 tunnel->allocated_down = max_rate;
2132
2133                 tunnel->init = tb_usb3_init;
2134                 tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
2135                 tunnel->release_unused_bandwidth =
2136                         tb_usb3_release_unused_bandwidth;
2137                 tunnel->reclaim_available_bandwidth =
2138                         tb_usb3_reclaim_available_bandwidth;
2139         }
2140
2141         return tunnel;
2142 }
2143
2144 /**
2145  * tb_tunnel_free() - free a tunnel
2146  * @tunnel: Tunnel to be freed
2147  *
2148  * Frees a tunnel. The tunnel does not need to be deactivated.
2149  */
2150 void tb_tunnel_free(struct tb_tunnel *tunnel)
2151 {
2152         int i;
2153
2154         if (!tunnel)
2155                 return;
2156
2157         if (tunnel->deinit)
2158                 tunnel->deinit(tunnel);
2159
2160         for (i = 0; i < tunnel->npaths; i++) {
2161                 if (tunnel->paths[i])
2162                         tb_path_free(tunnel->paths[i]);
2163         }
2164
2165         kfree(tunnel->paths);
2166         kfree(tunnel);
2167 }
2168
2169 /**
2170  * tb_tunnel_is_invalid - check whether an activated path is still valid
2171  * @tunnel: Tunnel to check
2172  */
2173 bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
2174 {
2175         int i;
2176
2177         for (i = 0; i < tunnel->npaths; i++) {
2178                 WARN_ON(!tunnel->paths[i]->activated);
2179                 if (tb_path_is_invalid(tunnel->paths[i]))
2180                         return true;
2181         }
2182
2183         return false;
2184 }
2185
2186 /**
2187  * tb_tunnel_restart() - activate a tunnel after a hardware reset
2188  * @tunnel: Tunnel to restart
2189  *
2190  * Return: 0 on success and negative errno in case if failure
2191  */
2192 int tb_tunnel_restart(struct tb_tunnel *tunnel)
2193 {
2194         int res, i;
2195
2196         tb_tunnel_dbg(tunnel, "activating\n");
2197
2198         /*
2199          * Make sure all paths are properly disabled before enabling
2200          * them again.
2201          */
2202         for (i = 0; i < tunnel->npaths; i++) {
2203                 if (tunnel->paths[i]->activated) {
2204                         tb_path_deactivate(tunnel->paths[i]);
2205                         tunnel->paths[i]->activated = false;
2206                 }
2207         }
2208
2209         if (tunnel->init) {
2210                 res = tunnel->init(tunnel);
2211                 if (res)
2212                         return res;
2213         }
2214
2215         for (i = 0; i < tunnel->npaths; i++) {
2216                 res = tb_path_activate(tunnel->paths[i]);
2217                 if (res)
2218                         goto err;
2219         }
2220
2221         if (tunnel->activate) {
2222                 res = tunnel->activate(tunnel, true);
2223                 if (res)
2224                         goto err;
2225         }
2226
2227         return 0;
2228
2229 err:
2230         tb_tunnel_warn(tunnel, "activation failed\n");
2231         tb_tunnel_deactivate(tunnel);
2232         return res;
2233 }
2234
2235 /**
2236  * tb_tunnel_activate() - activate a tunnel
2237  * @tunnel: Tunnel to activate
2238  *
2239  * Return: Returns 0 on success or an error code on failure.
2240  */
2241 int tb_tunnel_activate(struct tb_tunnel *tunnel)
2242 {
2243         int i;
2244
2245         for (i = 0; i < tunnel->npaths; i++) {
2246                 if (tunnel->paths[i]->activated) {
2247                         tb_tunnel_WARN(tunnel,
2248                                        "trying to activate an already activated tunnel\n");
2249                         return -EINVAL;
2250                 }
2251         }
2252
2253         return tb_tunnel_restart(tunnel);
2254 }
2255
2256 /**
2257  * tb_tunnel_deactivate() - deactivate a tunnel
2258  * @tunnel: Tunnel to deactivate
2259  */
2260 void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
2261 {
2262         int i;
2263
2264         tb_tunnel_dbg(tunnel, "deactivating\n");
2265
2266         if (tunnel->activate)
2267                 tunnel->activate(tunnel, false);
2268
2269         for (i = 0; i < tunnel->npaths; i++) {
2270                 if (tunnel->paths[i] && tunnel->paths[i]->activated)
2271                         tb_path_deactivate(tunnel->paths[i]);
2272         }
2273 }
2274
2275 /**
2276  * tb_tunnel_port_on_path() - Does the tunnel go through port
2277  * @tunnel: Tunnel to check
2278  * @port: Port to check
2279  *
2280  * Returns true if @tunnel goes through @port (direction does not matter),
2281  * false otherwise.
2282  */
2283 bool tb_tunnel_port_on_path(const struct tb_tunnel *tunnel,
2284                             const struct tb_port *port)
2285 {
2286         int i;
2287
2288         for (i = 0; i < tunnel->npaths; i++) {
2289                 if (!tunnel->paths[i])
2290                         continue;
2291
2292                 if (tb_path_port_on_path(tunnel->paths[i], port))
2293                         return true;
2294         }
2295
2296         return false;
2297 }
2298
2299 static bool tb_tunnel_is_active(const struct tb_tunnel *tunnel)
2300 {
2301         int i;
2302
2303         for (i = 0; i < tunnel->npaths; i++) {
2304                 if (!tunnel->paths[i])
2305                         return false;
2306                 if (!tunnel->paths[i]->activated)
2307                         return false;
2308         }
2309
2310         return true;
2311 }
2312
2313 /**
2314  * tb_tunnel_maximum_bandwidth() - Return maximum possible bandwidth
2315  * @tunnel: Tunnel to check
2316  * @max_up: Maximum upstream bandwidth in Mb/s
2317  * @max_down: Maximum downstream bandwidth in Mb/s
2318  *
2319  * Returns maximum possible bandwidth this tunnel can go if not limited
2320  * by other bandwidth clients. If the tunnel does not support this
2321  * returns %-EOPNOTSUPP.
2322  */
2323 int tb_tunnel_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,
2324                                 int *max_down)
2325 {
2326         if (!tb_tunnel_is_active(tunnel))
2327                 return -EINVAL;
2328
2329         if (tunnel->maximum_bandwidth)
2330                 return tunnel->maximum_bandwidth(tunnel, max_up, max_down);
2331         return -EOPNOTSUPP;
2332 }
2333
2334 /**
2335  * tb_tunnel_allocated_bandwidth() - Return bandwidth allocated for the tunnel
2336  * @tunnel: Tunnel to check
2337  * @allocated_up: Currently allocated upstream bandwidth in Mb/s is stored here
2338  * @allocated_down: Currently allocated downstream bandwidth in Mb/s is
2339  *                  stored here
2340  *
2341  * Returns the bandwidth allocated for the tunnel. This may be higher
2342  * than what the tunnel actually consumes.
2343  */
2344 int tb_tunnel_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,
2345                                   int *allocated_down)
2346 {
2347         if (!tb_tunnel_is_active(tunnel))
2348                 return -EINVAL;
2349
2350         if (tunnel->allocated_bandwidth)
2351                 return tunnel->allocated_bandwidth(tunnel, allocated_up,
2352                                                    allocated_down);
2353         return -EOPNOTSUPP;
2354 }
2355
2356 /**
2357  * tb_tunnel_alloc_bandwidth() - Change tunnel bandwidth allocation
2358  * @tunnel: Tunnel whose bandwidth allocation to change
2359  * @alloc_up: New upstream bandwidth in Mb/s
2360  * @alloc_down: New downstream bandwidth in Mb/s
2361  *
2362  * Tries to change tunnel bandwidth allocation. If succeeds returns %0
2363  * and updates @alloc_up and @alloc_down to that was actually allocated
2364  * (it may not be the same as passed originally). Returns negative errno
2365  * in case of failure.
2366  */
2367 int tb_tunnel_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,
2368                               int *alloc_down)
2369 {
2370         if (!tb_tunnel_is_active(tunnel))
2371                 return -EINVAL;
2372
2373         if (tunnel->alloc_bandwidth)
2374                 return tunnel->alloc_bandwidth(tunnel, alloc_up, alloc_down);
2375
2376         return -EOPNOTSUPP;
2377 }
2378
2379 /**
2380  * tb_tunnel_consumed_bandwidth() - Return bandwidth consumed by the tunnel
2381  * @tunnel: Tunnel to check
2382  * @consumed_up: Consumed bandwidth in Mb/s from @dst_port to @src_port.
2383  *               Can be %NULL.
2384  * @consumed_down: Consumed bandwidth in Mb/s from @src_port to @dst_port.
2385  *                 Can be %NULL.
2386  *
2387  * Stores the amount of isochronous bandwidth @tunnel consumes in
2388  * @consumed_up and @consumed_down. In case of success returns %0,
2389  * negative errno otherwise.
2390  */
2391 int tb_tunnel_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
2392                                  int *consumed_down)
2393 {
2394         int up_bw = 0, down_bw = 0;
2395
2396         if (!tb_tunnel_is_active(tunnel))
2397                 goto out;
2398
2399         if (tunnel->consumed_bandwidth) {
2400                 int ret;
2401
2402                 ret = tunnel->consumed_bandwidth(tunnel, &up_bw, &down_bw);
2403                 if (ret)
2404                         return ret;
2405
2406                 tb_tunnel_dbg(tunnel, "consumed bandwidth %d/%d Mb/s\n", up_bw,
2407                               down_bw);
2408         }
2409
2410 out:
2411         if (consumed_up)
2412                 *consumed_up = up_bw;
2413         if (consumed_down)
2414                 *consumed_down = down_bw;
2415
2416         return 0;
2417 }
2418
2419 /**
2420  * tb_tunnel_release_unused_bandwidth() - Release unused bandwidth
2421  * @tunnel: Tunnel whose unused bandwidth to release
2422  *
2423  * If tunnel supports dynamic bandwidth management (USB3 tunnels at the
2424  * moment) this function makes it to release all the unused bandwidth.
2425  *
2426  * Returns %0 in case of success and negative errno otherwise.
2427  */
2428 int tb_tunnel_release_unused_bandwidth(struct tb_tunnel *tunnel)
2429 {
2430         if (!tb_tunnel_is_active(tunnel))
2431                 return 0;
2432
2433         if (tunnel->release_unused_bandwidth) {
2434                 int ret;
2435
2436                 ret = tunnel->release_unused_bandwidth(tunnel);
2437                 if (ret)
2438                         return ret;
2439         }
2440
2441         return 0;
2442 }
2443
2444 /**
2445  * tb_tunnel_reclaim_available_bandwidth() - Reclaim available bandwidth
2446  * @tunnel: Tunnel reclaiming available bandwidth
2447  * @available_up: Available upstream bandwidth (in Mb/s)
2448  * @available_down: Available downstream bandwidth (in Mb/s)
2449  *
2450  * Reclaims bandwidth from @available_up and @available_down and updates
2451  * the variables accordingly (e.g decreases both according to what was
2452  * reclaimed by the tunnel). If nothing was reclaimed the values are
2453  * kept as is.
2454  */
2455 void tb_tunnel_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
2456                                            int *available_up,
2457                                            int *available_down)
2458 {
2459         if (!tb_tunnel_is_active(tunnel))
2460                 return;
2461
2462         if (tunnel->reclaim_available_bandwidth)
2463                 tunnel->reclaim_available_bandwidth(tunnel, available_up,
2464                                                     available_down);
2465 }
2466
2467 const char *tb_tunnel_type_name(const struct tb_tunnel *tunnel)
2468 {
2469         return tb_tunnel_names[tunnel->type];
2470 }