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 /* USB3 adapters use always HopID of 8 for both directions */
  25 #define TB_USB3_HOPID                   8
  26
  27 #define TB_USB3_PATH_DOWN               0
  28 #define TB_USB3_PATH_UP                 1
  29
  30 /* DP adapters use HopID 8 for AUX and 9 for Video */
  31 #define TB_DP_AUX_TX_HOPID              8
  32 #define TB_DP_AUX_RX_HOPID              8
  33 #define TB_DP_VIDEO_HOPID               9
  34
  35 #define TB_DP_VIDEO_PATH_OUT            0
  36 #define TB_DP_AUX_PATH_OUT              1
  37 #define TB_DP_AUX_PATH_IN               2
  38
  39 /* Minimum number of credits needed for PCIe path */
  40 #define TB_MIN_PCIE_CREDITS             6U
  41 /*
  42  * Number of credits we try to allocate for each DMA path if not limited
  43  * by the host router baMaxHI.
  44  */
  45 #define TB_DMA_CREDITS                  14
  46 /* Minimum number of credits for DMA path */
  47 #define TB_MIN_DMA_CREDITS              1
  48
  49 static unsigned int dma_credits = TB_DMA_CREDITS;
  50 module_param(dma_credits, uint, 0444);
  51 MODULE_PARM_DESC(dma_credits, "specify custom credits for DMA tunnels (default: "
  52                 __MODULE_STRING(TB_DMA_CREDITS) ")");
  53
  54 static bool bw_alloc_mode = true;
  55 module_param(bw_alloc_mode, bool, 0444);
  56 MODULE_PARM_DESC(bw_alloc_mode,
  57                  "enable bandwidth allocation mode if supported (default: true)");
  58
  59 static const char * const tb_tunnel_names[] = { "PCI", "DP", "DMA", "USB3" };
  60
  61 #define __TB_TUNNEL_PRINT(level, tunnel, fmt, arg...)                   \
  62         do {                                                            \
  63                 struct tb_tunnel *__tunnel = (tunnel);                  \
  64                 level(__tunnel->tb, "%llx:%u <-> %llx:%u (%s): " fmt,   \
  65                       tb_route(__tunnel->src_port->sw),                 \
  66                       __tunnel->src_port->port,                         \
  67                       tb_route(__tunnel->dst_port->sw),                 \
  68                       __tunnel->dst_port->port,                         \
  69                       tb_tunnel_names[__tunnel->type],                  \
  70                       ## arg);                                          \
  71         } while (0)
  72
  73 #define tb_tunnel_WARN(tunnel, fmt, arg...) \
  74         __TB_TUNNEL_PRINT(tb_WARN, tunnel, fmt, ##arg)
  75 #define tb_tunnel_warn(tunnel, fmt, arg...) \
  76         __TB_TUNNEL_PRINT(tb_warn, tunnel, fmt, ##arg)
  77 #define tb_tunnel_info(tunnel, fmt, arg...) \
  78         __TB_TUNNEL_PRINT(tb_info, tunnel, fmt, ##arg)
  79 #define tb_tunnel_dbg(tunnel, fmt, arg...) \
  80         __TB_TUNNEL_PRINT(tb_dbg, tunnel, fmt, ##arg)
  81
  82 static inline unsigned int tb_usable_credits(const struct tb_port *port)
  83 {
  84         return port->total_credits - port->ctl_credits;
  85 }
  86
  87 /**
  88  * tb_available_credits() - Available credits for PCIe and DMA
  89  * @port: Lane adapter to check
  90  * @max_dp_streams: If non-%NULL stores maximum number of simultaneous DP
  91  *                  streams possible through this lane adapter
  92  */
  93 static unsigned int tb_available_credits(const struct tb_port *port,
  94                                          size_t *max_dp_streams)
  95 {
  96         const struct tb_switch *sw = port->sw;
  97         int credits, usb3, pcie, spare;
  98         size_t ndp;
  99
 100         usb3 = tb_acpi_may_tunnel_usb3() ? sw->max_usb3_credits : 0;
 101         pcie = tb_acpi_may_tunnel_pcie() ? sw->max_pcie_credits : 0;
 102
 103         if (tb_acpi_is_xdomain_allowed()) {
 104                 spare = min_not_zero(sw->max_dma_credits, dma_credits);
 105                 /* Add some credits for potential second DMA tunnel */
 106                 spare += TB_MIN_DMA_CREDITS;
 107         } else {
 108                 spare = 0;
 109         }
 110
 111         credits = tb_usable_credits(port);
 112         if (tb_acpi_may_tunnel_dp()) {
 113                 /*
 114                  * Maximum number of DP streams possible through the
 115                  * lane adapter.
 116                  */
 117                 if (sw->min_dp_aux_credits + sw->min_dp_main_credits)
 118                         ndp = (credits - (usb3 + pcie + spare)) /
 119                               (sw->min_dp_aux_credits + sw->min_dp_main_credits);
 120                 else
 121                         ndp = 0;
 122         } else {
 123                 ndp = 0;
 124         }
 125         credits -= ndp * (sw->min_dp_aux_credits + sw->min_dp_main_credits);
 126         credits -= usb3;
 127
 128         if (max_dp_streams)
 129                 *max_dp_streams = ndp;
 130
 131         return credits > 0 ? credits : 0;
 132 }
 133
 134 static struct tb_tunnel *tb_tunnel_alloc(struct tb *tb, size_t npaths,
 135                                          enum tb_tunnel_type type)
 136 {
 137         struct tb_tunnel *tunnel;
 138
 139         tunnel = kzalloc(sizeof(*tunnel), GFP_KERNEL);
 140         if (!tunnel)
 141                 return NULL;
 142
 143         tunnel->paths = kcalloc(npaths, sizeof(tunnel->paths[0]), GFP_KERNEL);
 144         if (!tunnel->paths) {
 145                 tb_tunnel_free(tunnel);
 146                 return NULL;
 147         }
 148
 149         INIT_LIST_HEAD(&tunnel->list);
 150         tunnel->tb = tb;
 151         tunnel->npaths = npaths;
 152         tunnel->type = type;
 153
 154         return tunnel;
 155 }
 156
 157 static int tb_pci_set_ext_encapsulation(struct tb_tunnel *tunnel, bool enable)
 158 {
 159         int ret;
 160
 161         /* Only supported of both routers are at least USB4 v2 */
 162         if (usb4_switch_version(tunnel->src_port->sw) < 2 ||
 163             usb4_switch_version(tunnel->dst_port->sw) < 2)
 164                 return 0;
 165
 166         ret = usb4_pci_port_set_ext_encapsulation(tunnel->src_port, enable);
 167         if (ret)
 168                 return ret;
 169
 170         ret = usb4_pci_port_set_ext_encapsulation(tunnel->dst_port, enable);
 171         if (ret)
 172                 return ret;
 173
 174         tb_tunnel_dbg(tunnel, "extended encapsulation %s\n",
 175                       str_enabled_disabled(enable));
 176         return 0;
 177 }
 178
 179 static int tb_pci_activate(struct tb_tunnel *tunnel, bool activate)
 180 {
 181         int res;
 182
 183         if (activate) {
 184                 res = tb_pci_set_ext_encapsulation(tunnel, activate);
 185                 if (res)
 186                         return res;
 187         }
 188
 189         res = tb_pci_port_enable(tunnel->src_port, activate);
 190         if (res)
 191                 return res;
 192
 193         if (tb_port_is_pcie_up(tunnel->dst_port)) {
 194                 res = tb_pci_port_enable(tunnel->dst_port, activate);
 195                 if (res)
 196                         return res;
 197         }
 198
 199         return activate ? 0 : tb_pci_set_ext_encapsulation(tunnel, activate);
 200 }
 201
 202 static int tb_pci_init_credits(struct tb_path_hop *hop)
 203 {
 204         struct tb_port *port = hop->in_port;
 205         struct tb_switch *sw = port->sw;
 206         unsigned int credits;
 207
 208         if (tb_port_use_credit_allocation(port)) {
 209                 unsigned int available;
 210
 211                 available = tb_available_credits(port, NULL);
 212                 credits = min(sw->max_pcie_credits, available);
 213
 214                 if (credits < TB_MIN_PCIE_CREDITS)
 215                         return -ENOSPC;
 216
 217                 credits = max(TB_MIN_PCIE_CREDITS, credits);
 218         } else {
 219                 if (tb_port_is_null(port))
 220                         credits = port->bonded ? 32 : 16;
 221                 else
 222                         credits = 7;
 223         }
 224
 225         hop->initial_credits = credits;
 226         return 0;
 227 }
 228
 229 static int tb_pci_init_path(struct tb_path *path)
 230 {
 231         struct tb_path_hop *hop;
 232
 233         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
 234         path->egress_shared_buffer = TB_PATH_NONE;
 235         path->ingress_fc_enable = TB_PATH_ALL;
 236         path->ingress_shared_buffer = TB_PATH_NONE;
 237         path->priority = 3;
 238         path->weight = 1;
 239         path->drop_packages = 0;
 240
 241         tb_path_for_each_hop(path, hop) {
 242                 int ret;
 243
 244                 ret = tb_pci_init_credits(hop);
 245                 if (ret)
 246                         return ret;
 247         }
 248
 249         return 0;
 250 }
 251
 252 /**
 253  * tb_tunnel_discover_pci() - Discover existing PCIe tunnels
 254  * @tb: Pointer to the domain structure
 255  * @down: PCIe downstream adapter
 256  * @alloc_hopid: Allocate HopIDs from visited ports
 257  *
 258  * If @down adapter is active, follows the tunnel to the PCIe upstream
 259  * adapter and back. Returns the discovered tunnel or %NULL if there was
 260  * no tunnel.
 261  */
 262 struct tb_tunnel *tb_tunnel_discover_pci(struct tb *tb, struct tb_port *down,
 263                                          bool alloc_hopid)
 264 {
 265         struct tb_tunnel *tunnel;
 266         struct tb_path *path;
 267
 268         if (!tb_pci_port_is_enabled(down))
 269                 return NULL;
 270
 271         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
 272         if (!tunnel)
 273                 return NULL;
 274
 275         tunnel->activate = tb_pci_activate;
 276         tunnel->src_port = down;
 277
 278         /*
 279          * Discover both paths even if they are not complete. We will
 280          * clean them up by calling tb_tunnel_deactivate() below in that
 281          * case.
 282          */
 283         path = tb_path_discover(down, TB_PCI_HOPID, NULL, -1,
 284                                 &tunnel->dst_port, "PCIe Up", alloc_hopid);
 285         if (!path) {
 286                 /* Just disable the downstream port */
 287                 tb_pci_port_enable(down, false);
 288                 goto err_free;
 289         }
 290         tunnel->paths[TB_PCI_PATH_UP] = path;
 291         if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_UP]))
 292                 goto err_free;
 293
 294         path = tb_path_discover(tunnel->dst_port, -1, down, TB_PCI_HOPID, NULL,
 295                                 "PCIe Down", alloc_hopid);
 296         if (!path)
 297                 goto err_deactivate;
 298         tunnel->paths[TB_PCI_PATH_DOWN] = path;
 299         if (tb_pci_init_path(tunnel->paths[TB_PCI_PATH_DOWN]))
 300                 goto err_deactivate;
 301
 302         /* Validate that the tunnel is complete */
 303         if (!tb_port_is_pcie_up(tunnel->dst_port)) {
 304                 tb_port_warn(tunnel->dst_port,
 305                              "path does not end on a PCIe adapter, cleaning up\n");
 306                 goto err_deactivate;
 307         }
 308
 309         if (down != tunnel->src_port) {
 310                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
 311                 goto err_deactivate;
 312         }
 313
 314         if (!tb_pci_port_is_enabled(tunnel->dst_port)) {
 315                 tb_tunnel_warn(tunnel,
 316                                "tunnel is not fully activated, cleaning up\n");
 317                 goto err_deactivate;
 318         }
 319
 320         tb_tunnel_dbg(tunnel, "discovered\n");
 321         return tunnel;
 322
 323 err_deactivate:
 324         tb_tunnel_deactivate(tunnel);
 325 err_free:
 326         tb_tunnel_free(tunnel);
 327
 328         return NULL;
 329 }
 330
 331 /**
 332  * tb_tunnel_alloc_pci() - allocate a pci tunnel
 333  * @tb: Pointer to the domain structure
 334  * @up: PCIe upstream adapter port
 335  * @down: PCIe downstream adapter port
 336  *
 337  * Allocate a PCI tunnel. The ports must be of type TB_TYPE_PCIE_UP and
 338  * TB_TYPE_PCIE_DOWN.
 339  *
 340  * Return: Returns a tb_tunnel on success or NULL on failure.
 341  */
 342 struct tb_tunnel *tb_tunnel_alloc_pci(struct tb *tb, struct tb_port *up,
 343                                       struct tb_port *down)
 344 {
 345         struct tb_tunnel *tunnel;
 346         struct tb_path *path;
 347
 348         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_PCI);
 349         if (!tunnel)
 350                 return NULL;
 351
 352         tunnel->activate = tb_pci_activate;
 353         tunnel->src_port = down;
 354         tunnel->dst_port = up;
 355
 356         path = tb_path_alloc(tb, down, TB_PCI_HOPID, up, TB_PCI_HOPID, 0,
 357                              "PCIe Down");
 358         if (!path)
 359                 goto err_free;
 360         tunnel->paths[TB_PCI_PATH_DOWN] = path;
 361         if (tb_pci_init_path(path))
 362                 goto err_free;
 363
 364         path = tb_path_alloc(tb, up, TB_PCI_HOPID, down, TB_PCI_HOPID, 0,
 365                              "PCIe Up");
 366         if (!path)
 367                 goto err_free;
 368         tunnel->paths[TB_PCI_PATH_UP] = path;
 369         if (tb_pci_init_path(path))
 370                 goto err_free;
 371
 372         return tunnel;
 373
 374 err_free:
 375         tb_tunnel_free(tunnel);
 376         return NULL;
 377 }
 378
 379 static bool tb_dp_is_usb4(const struct tb_switch *sw)
 380 {
 381         /* Titan Ridge DP adapters need the same treatment as USB4 */
 382         return tb_switch_is_usb4(sw) || tb_switch_is_titan_ridge(sw);
 383 }
 384
 385 static int tb_dp_cm_handshake(struct tb_port *in, struct tb_port *out,
 386                               int timeout_msec)
 387 {
 388         ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
 389         u32 val;
 390         int ret;
 391
 392         /* Both ends need to support this */
 393         if (!tb_dp_is_usb4(in->sw) || !tb_dp_is_usb4(out->sw))
 394                 return 0;
 395
 396         ret = tb_port_read(out, &val, TB_CFG_PORT,
 397                            out->cap_adap + DP_STATUS_CTRL, 1);
 398         if (ret)
 399                 return ret;
 400
 401         val |= DP_STATUS_CTRL_UF | DP_STATUS_CTRL_CMHS;
 402
 403         ret = tb_port_write(out, &val, TB_CFG_PORT,
 404                             out->cap_adap + DP_STATUS_CTRL, 1);
 405         if (ret)
 406                 return ret;
 407
 408         do {
 409                 ret = tb_port_read(out, &val, TB_CFG_PORT,
 410                                    out->cap_adap + DP_STATUS_CTRL, 1);
 411                 if (ret)
 412                         return ret;
 413                 if (!(val & DP_STATUS_CTRL_CMHS))
 414                         return 0;
 415                 usleep_range(100, 150);
 416         } while (ktime_before(ktime_get(), timeout));
 417
 418         return -ETIMEDOUT;
 419 }
 420
 421 /*
 422  * Returns maximum possible rate from capability supporting only DP 2.0
 423  * and below. Used when DP BW allocation mode is not enabled.
 424  */
 425 static inline u32 tb_dp_cap_get_rate(u32 val)
 426 {
 427         u32 rate = (val & DP_COMMON_CAP_RATE_MASK) >> DP_COMMON_CAP_RATE_SHIFT;
 428
 429         switch (rate) {
 430         case DP_COMMON_CAP_RATE_RBR:
 431                 return 1620;
 432         case DP_COMMON_CAP_RATE_HBR:
 433                 return 2700;
 434         case DP_COMMON_CAP_RATE_HBR2:
 435                 return 5400;
 436         case DP_COMMON_CAP_RATE_HBR3:
 437                 return 8100;
 438         default:
 439                 return 0;
 440         }
 441 }
 442
 443 /*
 444  * Returns maximum possible rate from capability supporting DP 2.1
 445  * UHBR20, 13.5 and 10 rates as well. Use only when DP BW allocation
 446  * mode is enabled.
 447  */
 448 static inline u32 tb_dp_cap_get_rate_ext(u32 val)
 449 {
 450         if (val & DP_COMMON_CAP_UHBR20)
 451                 return 20000;
 452         else if (val & DP_COMMON_CAP_UHBR13_5)
 453                 return 13500;
 454         else if (val & DP_COMMON_CAP_UHBR10)
 455                 return 10000;
 456
 457         return tb_dp_cap_get_rate(val);
 458 }
 459
 460 static inline bool tb_dp_is_uhbr_rate(unsigned int rate)
 461 {
 462         return rate >= 10000;
 463 }
 464
 465 static inline u32 tb_dp_cap_set_rate(u32 val, u32 rate)
 466 {
 467         val &= ~DP_COMMON_CAP_RATE_MASK;
 468         switch (rate) {
 469         default:
 470                 WARN(1, "invalid rate %u passed, defaulting to 1620 MB/s\n", rate);
 471                 fallthrough;
 472         case 1620:
 473                 val |= DP_COMMON_CAP_RATE_RBR << DP_COMMON_CAP_RATE_SHIFT;
 474                 break;
 475         case 2700:
 476                 val |= DP_COMMON_CAP_RATE_HBR << DP_COMMON_CAP_RATE_SHIFT;
 477                 break;
 478         case 5400:
 479                 val |= DP_COMMON_CAP_RATE_HBR2 << DP_COMMON_CAP_RATE_SHIFT;
 480                 break;
 481         case 8100:
 482                 val |= DP_COMMON_CAP_RATE_HBR3 << DP_COMMON_CAP_RATE_SHIFT;
 483                 break;
 484         }
 485         return val;
 486 }
 487
 488 static inline u32 tb_dp_cap_get_lanes(u32 val)
 489 {
 490         u32 lanes = (val & DP_COMMON_CAP_LANES_MASK) >> DP_COMMON_CAP_LANES_SHIFT;
 491
 492         switch (lanes) {
 493         case DP_COMMON_CAP_1_LANE:
 494                 return 1;
 495         case DP_COMMON_CAP_2_LANES:
 496                 return 2;
 497         case DP_COMMON_CAP_4_LANES:
 498                 return 4;
 499         default:
 500                 return 0;
 501         }
 502 }
 503
 504 static inline u32 tb_dp_cap_set_lanes(u32 val, u32 lanes)
 505 {
 506         val &= ~DP_COMMON_CAP_LANES_MASK;
 507         switch (lanes) {
 508         default:
 509                 WARN(1, "invalid number of lanes %u passed, defaulting to 1\n",
 510                      lanes);
 511                 fallthrough;
 512         case 1:
 513                 val |= DP_COMMON_CAP_1_LANE << DP_COMMON_CAP_LANES_SHIFT;
 514                 break;
 515         case 2:
 516                 val |= DP_COMMON_CAP_2_LANES << DP_COMMON_CAP_LANES_SHIFT;
 517                 break;
 518         case 4:
 519                 val |= DP_COMMON_CAP_4_LANES << DP_COMMON_CAP_LANES_SHIFT;
 520                 break;
 521         }
 522         return val;
 523 }
 524
 525 static unsigned int tb_dp_bandwidth(unsigned int rate, unsigned int lanes)
 526 {
 527         /* Tunneling removes the DP 8b/10b 128/132b encoding */
 528         if (tb_dp_is_uhbr_rate(rate))
 529                 return rate * lanes * 128 / 132;
 530         return rate * lanes * 8 / 10;
 531 }
 532
 533 static int tb_dp_reduce_bandwidth(int max_bw, u32 in_rate, u32 in_lanes,
 534                                   u32 out_rate, u32 out_lanes, u32 *new_rate,
 535                                   u32 *new_lanes)
 536 {
 537         static const u32 dp_bw[][2] = {
 538                 /* Mb/s, lanes */
 539                 { 8100, 4 }, /* 25920 Mb/s */
 540                 { 5400, 4 }, /* 17280 Mb/s */
 541                 { 8100, 2 }, /* 12960 Mb/s */
 542                 { 2700, 4 }, /* 8640 Mb/s */
 543                 { 5400, 2 }, /* 8640 Mb/s */
 544                 { 8100, 1 }, /* 6480 Mb/s */
 545                 { 1620, 4 }, /* 5184 Mb/s */
 546                 { 5400, 1 }, /* 4320 Mb/s */
 547                 { 2700, 2 }, /* 4320 Mb/s */
 548                 { 1620, 2 }, /* 2592 Mb/s */
 549                 { 2700, 1 }, /* 2160 Mb/s */
 550                 { 1620, 1 }, /* 1296 Mb/s */
 551         };
 552         unsigned int i;
 553
 554         /*
 555          * Find a combination that can fit into max_bw and does not
 556          * exceed the maximum rate and lanes supported by the DP OUT and
 557          * DP IN adapters.
 558          */
 559         for (i = 0; i < ARRAY_SIZE(dp_bw); i++) {
 560                 if (dp_bw[i][0] > out_rate || dp_bw[i][1] > out_lanes)
 561                         continue;
 562
 563                 if (dp_bw[i][0] > in_rate || dp_bw[i][1] > in_lanes)
 564                         continue;
 565
 566                 if (tb_dp_bandwidth(dp_bw[i][0], dp_bw[i][1]) <= max_bw) {
 567                         *new_rate = dp_bw[i][0];
 568                         *new_lanes = dp_bw[i][1];
 569                         return 0;
 570                 }
 571         }
 572
 573         return -ENOSR;
 574 }
 575
 576 static int tb_dp_xchg_caps(struct tb_tunnel *tunnel)
 577 {
 578         u32 out_dp_cap, out_rate, out_lanes, in_dp_cap, in_rate, in_lanes, bw;
 579         struct tb_port *out = tunnel->dst_port;
 580         struct tb_port *in = tunnel->src_port;
 581         int ret, max_bw;
 582
 583         /*
 584          * Copy DP_LOCAL_CAP register to DP_REMOTE_CAP register for
 585          * newer generation hardware.
 586          */
 587         if (in->sw->generation < 2 || out->sw->generation < 2)
 588                 return 0;
 589
 590         /*
 591          * Perform connection manager handshake between IN and OUT ports
 592          * before capabilities exchange can take place.
 593          */
 594         ret = tb_dp_cm_handshake(in, out, 3000);
 595         if (ret)
 596                 return ret;
 597
 598         /* Read both DP_LOCAL_CAP registers */
 599         ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
 600                            in->cap_adap + DP_LOCAL_CAP, 1);
 601         if (ret)
 602                 return ret;
 603
 604         ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
 605                            out->cap_adap + DP_LOCAL_CAP, 1);
 606         if (ret)
 607                 return ret;
 608
 609         /* Write IN local caps to OUT remote caps */
 610         ret = tb_port_write(out, &in_dp_cap, TB_CFG_PORT,
 611                             out->cap_adap + DP_REMOTE_CAP, 1);
 612         if (ret)
 613                 return ret;
 614
 615         in_rate = tb_dp_cap_get_rate(in_dp_cap);
 616         in_lanes = tb_dp_cap_get_lanes(in_dp_cap);
 617         tb_port_dbg(in, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
 618                     in_rate, in_lanes, tb_dp_bandwidth(in_rate, in_lanes));
 619
 620         /*
 621          * If the tunnel bandwidth is limited (max_bw is set) then see
 622          * if we need to reduce bandwidth to fit there.
 623          */
 624         out_rate = tb_dp_cap_get_rate(out_dp_cap);
 625         out_lanes = tb_dp_cap_get_lanes(out_dp_cap);
 626         bw = tb_dp_bandwidth(out_rate, out_lanes);
 627         tb_port_dbg(out, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
 628                     out_rate, out_lanes, bw);
 629
 630         if (in->sw->config.depth < out->sw->config.depth)
 631                 max_bw = tunnel->max_down;
 632         else
 633                 max_bw = tunnel->max_up;
 634
 635         if (max_bw && bw > max_bw) {
 636                 u32 new_rate, new_lanes, new_bw;
 637
 638                 ret = tb_dp_reduce_bandwidth(max_bw, in_rate, in_lanes,
 639                                              out_rate, out_lanes, &new_rate,
 640                                              &new_lanes);
 641                 if (ret) {
 642                         tb_port_info(out, "not enough bandwidth for DP tunnel\n");
 643                         return ret;
 644                 }
 645
 646                 new_bw = tb_dp_bandwidth(new_rate, new_lanes);
 647                 tb_port_dbg(out, "bandwidth reduced to %u Mb/s x%u = %u Mb/s\n",
 648                             new_rate, new_lanes, new_bw);
 649
 650                 /*
 651                  * Set new rate and number of lanes before writing it to
 652                  * the IN port remote caps.
 653                  */
 654                 out_dp_cap = tb_dp_cap_set_rate(out_dp_cap, new_rate);
 655                 out_dp_cap = tb_dp_cap_set_lanes(out_dp_cap, new_lanes);
 656         }
 657
 658         /*
 659          * Titan Ridge does not disable AUX timers when it gets
 660          * SET_CONFIG with SET_LTTPR_MODE set. This causes problems with
 661          * DP tunneling.
 662          */
 663         if (tb_route(out->sw) && tb_switch_is_titan_ridge(out->sw)) {
 664                 out_dp_cap |= DP_COMMON_CAP_LTTPR_NS;
 665                 tb_port_dbg(out, "disabling LTTPR\n");
 666         }
 667
 668         return tb_port_write(in, &out_dp_cap, TB_CFG_PORT,
 669                              in->cap_adap + DP_REMOTE_CAP, 1);
 670 }
 671
 672 static int tb_dp_bandwidth_alloc_mode_enable(struct tb_tunnel *tunnel)
 673 {
 674         int ret, estimated_bw, granularity, tmp;
 675         struct tb_port *out = tunnel->dst_port;
 676         struct tb_port *in = tunnel->src_port;
 677         u32 out_dp_cap, out_rate, out_lanes;
 678         u32 in_dp_cap, in_rate, in_lanes;
 679         u32 rate, lanes;
 680
 681         if (!bw_alloc_mode)
 682                 return 0;
 683
 684         ret = usb4_dp_port_set_cm_bandwidth_mode_supported(in, true);
 685         if (ret)
 686                 return ret;
 687
 688         ret = usb4_dp_port_set_group_id(in, in->group->index);
 689         if (ret)
 690                 return ret;
 691
 692         /*
 693          * Get the non-reduced rate and lanes based on the lowest
 694          * capability of both adapters.
 695          */
 696         ret = tb_port_read(in, &in_dp_cap, TB_CFG_PORT,
 697                            in->cap_adap + DP_LOCAL_CAP, 1);
 698         if (ret)
 699                 return ret;
 700
 701         ret = tb_port_read(out, &out_dp_cap, TB_CFG_PORT,
 702                            out->cap_adap + DP_LOCAL_CAP, 1);
 703         if (ret)
 704                 return ret;
 705
 706         in_rate = tb_dp_cap_get_rate(in_dp_cap);
 707         in_lanes = tb_dp_cap_get_lanes(in_dp_cap);
 708         out_rate = tb_dp_cap_get_rate(out_dp_cap);
 709         out_lanes = tb_dp_cap_get_lanes(out_dp_cap);
 710
 711         rate = min(in_rate, out_rate);
 712         lanes = min(in_lanes, out_lanes);
 713         tmp = tb_dp_bandwidth(rate, lanes);
 714
 715         tb_port_dbg(in, "non-reduced bandwidth %u Mb/s x%u = %u Mb/s\n", rate,
 716                     lanes, tmp);
 717
 718         ret = usb4_dp_port_set_nrd(in, rate, lanes);
 719         if (ret)
 720                 return ret;
 721
 722         /*
 723          * Pick up granularity that supports maximum possible bandwidth.
 724          * For that we use the UHBR rates too.
 725          */
 726         in_rate = tb_dp_cap_get_rate_ext(in_dp_cap);
 727         out_rate = tb_dp_cap_get_rate_ext(out_dp_cap);
 728         rate = min(in_rate, out_rate);
 729         tmp = tb_dp_bandwidth(rate, lanes);
 730
 731         tb_port_dbg(in,
 732                     "maximum bandwidth through allocation mode %u Mb/s x%u = %u Mb/s\n",
 733                     rate, lanes, tmp);
 734
 735         for (granularity = 250; tmp / granularity > 255 && granularity <= 1000;
 736              granularity *= 2)
 737                 ;
 738
 739         tb_port_dbg(in, "granularity %d Mb/s\n", granularity);
 740
 741         /*
 742          * Returns -EINVAL if granularity above is outside of the
 743          * accepted ranges.
 744          */
 745         ret = usb4_dp_port_set_granularity(in, granularity);
 746         if (ret)
 747                 return ret;
 748
 749         /*
 750          * Bandwidth estimation is pretty much what we have in
 751          * max_up/down fields. For discovery we just read what the
 752          * estimation was set to.
 753          */
 754         if (in->sw->config.depth < out->sw->config.depth)
 755                 estimated_bw = tunnel->max_down;
 756         else
 757                 estimated_bw = tunnel->max_up;
 758
 759         tb_port_dbg(in, "estimated bandwidth %d Mb/s\n", estimated_bw);
 760
 761         ret = usb4_dp_port_set_estimated_bandwidth(in, estimated_bw);
 762         if (ret)
 763                 return ret;
 764
 765         /* Initial allocation should be 0 according the spec */
 766         ret = usb4_dp_port_allocate_bandwidth(in, 0);
 767         if (ret)
 768                 return ret;
 769
 770         tb_port_dbg(in, "bandwidth allocation mode enabled\n");
 771         return 0;
 772 }
 773
 774 static int tb_dp_init(struct tb_tunnel *tunnel)
 775 {
 776         struct tb_port *in = tunnel->src_port;
 777         struct tb_switch *sw = in->sw;
 778         struct tb *tb = in->sw->tb;
 779         int ret;
 780
 781         ret = tb_dp_xchg_caps(tunnel);
 782         if (ret)
 783                 return ret;
 784
 785         if (!tb_switch_is_usb4(sw))
 786                 return 0;
 787
 788         if (!usb4_dp_port_bandwidth_mode_supported(in))
 789                 return 0;
 790
 791         tb_port_dbg(in, "bandwidth allocation mode supported\n");
 792
 793         ret = usb4_dp_port_set_cm_id(in, tb->index);
 794         if (ret)
 795                 return ret;
 796
 797         return tb_dp_bandwidth_alloc_mode_enable(tunnel);
 798 }
 799
 800 static void tb_dp_deinit(struct tb_tunnel *tunnel)
 801 {
 802         struct tb_port *in = tunnel->src_port;
 803
 804         if (!usb4_dp_port_bandwidth_mode_supported(in))
 805                 return;
 806         if (usb4_dp_port_bandwidth_mode_enabled(in)) {
 807                 usb4_dp_port_set_cm_bandwidth_mode_supported(in, false);
 808                 tb_port_dbg(in, "bandwidth allocation mode disabled\n");
 809         }
 810 }
 811
 812 static int tb_dp_activate(struct tb_tunnel *tunnel, bool active)
 813 {
 814         int ret;
 815
 816         if (active) {
 817                 struct tb_path **paths;
 818                 int last;
 819
 820                 paths = tunnel->paths;
 821                 last = paths[TB_DP_VIDEO_PATH_OUT]->path_length - 1;
 822
 823                 tb_dp_port_set_hops(tunnel->src_port,
 824                         paths[TB_DP_VIDEO_PATH_OUT]->hops[0].in_hop_index,
 825                         paths[TB_DP_AUX_PATH_OUT]->hops[0].in_hop_index,
 826                         paths[TB_DP_AUX_PATH_IN]->hops[last].next_hop_index);
 827
 828                 tb_dp_port_set_hops(tunnel->dst_port,
 829                         paths[TB_DP_VIDEO_PATH_OUT]->hops[last].next_hop_index,
 830                         paths[TB_DP_AUX_PATH_IN]->hops[0].in_hop_index,
 831                         paths[TB_DP_AUX_PATH_OUT]->hops[last].next_hop_index);
 832         } else {
 833                 tb_dp_port_hpd_clear(tunnel->src_port);
 834                 tb_dp_port_set_hops(tunnel->src_port, 0, 0, 0);
 835                 if (tb_port_is_dpout(tunnel->dst_port))
 836                         tb_dp_port_set_hops(tunnel->dst_port, 0, 0, 0);
 837         }
 838
 839         ret = tb_dp_port_enable(tunnel->src_port, active);
 840         if (ret)
 841                 return ret;
 842
 843         if (tb_port_is_dpout(tunnel->dst_port))
 844                 return tb_dp_port_enable(tunnel->dst_port, active);
 845
 846         return 0;
 847 }
 848
 849 /* max_bw is rounded up to next granularity */
 850 static int tb_dp_bandwidth_mode_maximum_bandwidth(struct tb_tunnel *tunnel,
 851                                                   int *max_bw)
 852 {
 853         struct tb_port *in = tunnel->src_port;
 854         int ret, rate, lanes, nrd_bw;
 855         u32 cap;
 856
 857         /*
 858          * DP IN adapter DP_LOCAL_CAP gets updated to the lowest AUX
 859          * read parameter values so this so we can use this to determine
 860          * the maximum possible bandwidth over this link.
 861          *
 862          * See USB4 v2 spec 1.0 10.4.4.5.
 863          */
 864         ret = tb_port_read(in, &cap, TB_CFG_PORT,
 865                            in->cap_adap + DP_LOCAL_CAP, 1);
 866         if (ret)
 867                 return ret;
 868
 869         rate = tb_dp_cap_get_rate_ext(cap);
 870         if (tb_dp_is_uhbr_rate(rate)) {
 871                 /*
 872                  * When UHBR is used there is no reduction in lanes so
 873                  * we can use this directly.
 874                  */
 875                 lanes = tb_dp_cap_get_lanes(cap);
 876         } else {
 877                 /*
 878                  * If there is no UHBR supported then check the
 879                  * non-reduced rate and lanes.
 880                  */
 881                 ret = usb4_dp_port_nrd(in, &rate, &lanes);
 882                 if (ret)
 883                         return ret;
 884         }
 885
 886         nrd_bw = tb_dp_bandwidth(rate, lanes);
 887
 888         if (max_bw) {
 889                 ret = usb4_dp_port_granularity(in);
 890                 if (ret < 0)
 891                         return ret;
 892                 *max_bw = roundup(nrd_bw, ret);
 893         }
 894
 895         return nrd_bw;
 896 }
 897
 898 static int tb_dp_bandwidth_mode_consumed_bandwidth(struct tb_tunnel *tunnel,
 899                                                    int *consumed_up,
 900                                                    int *consumed_down)
 901 {
 902         struct tb_port *out = tunnel->dst_port;
 903         struct tb_port *in = tunnel->src_port;
 904         int ret, allocated_bw, max_bw;
 905
 906         if (!usb4_dp_port_bandwidth_mode_enabled(in))
 907                 return -EOPNOTSUPP;
 908
 909         if (!tunnel->bw_mode)
 910                 return -EOPNOTSUPP;
 911
 912         /* Read what was allocated previously if any */
 913         ret = usb4_dp_port_allocated_bandwidth(in);
 914         if (ret < 0)
 915                 return ret;
 916         allocated_bw = ret;
 917
 918         ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw);
 919         if (ret < 0)
 920                 return ret;
 921         if (allocated_bw == max_bw)
 922                 allocated_bw = ret;
 923
 924         tb_port_dbg(in, "consumed bandwidth through allocation mode %d Mb/s\n",
 925                     allocated_bw);
 926
 927         if (in->sw->config.depth < out->sw->config.depth) {
 928                 *consumed_up = 0;
 929                 *consumed_down = allocated_bw;
 930         } else {
 931                 *consumed_up = allocated_bw;
 932                 *consumed_down = 0;
 933         }
 934
 935         return 0;
 936 }
 937
 938 static int tb_dp_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,
 939                                      int *allocated_down)
 940 {
 941         struct tb_port *out = tunnel->dst_port;
 942         struct tb_port *in = tunnel->src_port;
 943
 944         /*
 945          * If we have already set the allocated bandwidth then use that.
 946          * Otherwise we read it from the DPRX.
 947          */
 948         if (usb4_dp_port_bandwidth_mode_enabled(in) && tunnel->bw_mode) {
 949                 int ret, allocated_bw, max_bw;
 950
 951                 ret = usb4_dp_port_allocated_bandwidth(in);
 952                 if (ret < 0)
 953                         return ret;
 954                 allocated_bw = ret;
 955
 956                 ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw);
 957                 if (ret < 0)
 958                         return ret;
 959                 if (allocated_bw == max_bw)
 960                         allocated_bw = ret;
 961
 962                 if (in->sw->config.depth < out->sw->config.depth) {
 963                         *allocated_up = 0;
 964                         *allocated_down = allocated_bw;
 965                 } else {
 966                         *allocated_up = allocated_bw;
 967                         *allocated_down = 0;
 968                 }
 969                 return 0;
 970         }
 971
 972         return tunnel->consumed_bandwidth(tunnel, allocated_up,
 973                                           allocated_down);
 974 }
 975
 976 static int tb_dp_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,
 977                                  int *alloc_down)
 978 {
 979         struct tb_port *out = tunnel->dst_port;
 980         struct tb_port *in = tunnel->src_port;
 981         int max_bw, ret, tmp;
 982
 983         if (!usb4_dp_port_bandwidth_mode_enabled(in))
 984                 return -EOPNOTSUPP;
 985
 986         ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, &max_bw);
 987         if (ret < 0)
 988                 return ret;
 989
 990         if (in->sw->config.depth < out->sw->config.depth) {
 991                 tmp = min(*alloc_down, max_bw);
 992                 ret = usb4_dp_port_allocate_bandwidth(in, tmp);
 993                 if (ret)
 994                         return ret;
 995                 *alloc_down = tmp;
 996                 *alloc_up = 0;
 997         } else {
 998                 tmp = min(*alloc_up, max_bw);
 999                 ret = usb4_dp_port_allocate_bandwidth(in, tmp);
1000                 if (ret)
1001                         return ret;
1002                 *alloc_down = 0;
1003                 *alloc_up = tmp;
1004         }
1005
1006         /* Now we can use BW mode registers to figure out the bandwidth */
1007         /* TODO: need to handle discovery too */
1008         tunnel->bw_mode = true;
1009
1010         tb_port_dbg(in, "allocated bandwidth through allocation mode %d Mb/s\n",
1011                     tmp);
1012         return 0;
1013 }
1014
1015 static int tb_dp_read_dprx(struct tb_tunnel *tunnel, u32 *rate, u32 *lanes,
1016                            int timeout_msec)
1017 {
1018         ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
1019         struct tb_port *in = tunnel->src_port;
1020
1021         /*
1022          * Wait for DPRX done. Normally it should be already set for
1023          * active tunnel.
1024          */
1025         do {
1026                 u32 val;
1027                 int ret;
1028
1029                 ret = tb_port_read(in, &val, TB_CFG_PORT,
1030                                    in->cap_adap + DP_COMMON_CAP, 1);
1031                 if (ret)
1032                         return ret;
1033
1034                 if (val & DP_COMMON_CAP_DPRX_DONE) {
1035                         *rate = tb_dp_cap_get_rate(val);
1036                         *lanes = tb_dp_cap_get_lanes(val);
1037
1038                         tb_port_dbg(in, "consumed bandwidth through DPRX %d Mb/s\n",
1039                                     tb_dp_bandwidth(*rate, *lanes));
1040                         return 0;
1041                 }
1042                 usleep_range(100, 150);
1043         } while (ktime_before(ktime_get(), timeout));
1044
1045         return -ETIMEDOUT;
1046 }
1047
1048 /* Read cap from tunnel DP IN */
1049 static int tb_dp_read_cap(struct tb_tunnel *tunnel, unsigned int cap, u32 *rate,
1050                           u32 *lanes)
1051 {
1052         struct tb_port *in = tunnel->src_port;
1053         u32 val;
1054         int ret;
1055
1056         switch (cap) {
1057         case DP_LOCAL_CAP:
1058         case DP_REMOTE_CAP:
1059                 break;
1060
1061         default:
1062                 tb_tunnel_WARN(tunnel, "invalid capability index %#x\n", cap);
1063                 return -EINVAL;
1064         }
1065
1066         /*
1067          * Read from the copied remote cap so that we take into account
1068          * if capabilities were reduced during exchange.
1069          */
1070         ret = tb_port_read(in, &val, TB_CFG_PORT, in->cap_adap + cap, 1);
1071         if (ret)
1072                 return ret;
1073
1074         *rate = tb_dp_cap_get_rate(val);
1075         *lanes = tb_dp_cap_get_lanes(val);
1076
1077         tb_port_dbg(in, "bandwidth from %#x capability %d Mb/s\n", cap,
1078                     tb_dp_bandwidth(*rate, *lanes));
1079         return 0;
1080 }
1081
1082 static int tb_dp_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,
1083                                    int *max_down)
1084 {
1085         struct tb_port *in = tunnel->src_port;
1086         int ret;
1087
1088         if (!usb4_dp_port_bandwidth_mode_enabled(in))
1089                 return -EOPNOTSUPP;
1090
1091         ret = tb_dp_bandwidth_mode_maximum_bandwidth(tunnel, NULL);
1092         if (ret < 0)
1093                 return ret;
1094
1095         if (in->sw->config.depth < tunnel->dst_port->sw->config.depth) {
1096                 *max_up = 0;
1097                 *max_down = ret;
1098         } else {
1099                 *max_up = ret;
1100                 *max_down = 0;
1101         }
1102
1103         return 0;
1104 }
1105
1106 static int tb_dp_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
1107                                     int *consumed_down)
1108 {
1109         struct tb_port *in = tunnel->src_port;
1110         const struct tb_switch *sw = in->sw;
1111         u32 rate = 0, lanes = 0;
1112         int ret;
1113
1114         if (tb_dp_is_usb4(sw)) {
1115                 /*
1116                  * On USB4 routers check if the bandwidth allocation
1117                  * mode is enabled first and then read the bandwidth
1118                  * through those registers.
1119                  */
1120                 ret = tb_dp_bandwidth_mode_consumed_bandwidth(tunnel, consumed_up,
1121                                                               consumed_down);
1122                 if (ret < 0) {
1123                         if (ret != -EOPNOTSUPP)
1124                                 return ret;
1125                 } else if (!ret) {
1126                         return 0;
1127                 }
1128                 /*
1129                  * Then see if the DPRX negotiation is ready and if yes
1130                  * return that bandwidth (it may be smaller than the
1131                  * reduced one). Otherwise return the remote (possibly
1132                  * reduced) caps.
1133                  */
1134                 ret = tb_dp_read_dprx(tunnel, &rate, &lanes, 150);
1135                 if (ret) {
1136                         if (ret == -ETIMEDOUT)
1137                                 ret = tb_dp_read_cap(tunnel, DP_REMOTE_CAP,
1138                                                      &rate, &lanes);
1139                         if (ret)
1140                                 return ret;
1141                 }
1142         } else if (sw->generation >= 2) {
1143                 ret = tb_dp_read_cap(tunnel, DP_REMOTE_CAP, &rate, &lanes);
1144                 if (ret)
1145                         return ret;
1146         } else {
1147                 /* No bandwidth management for legacy devices  */
1148                 *consumed_up = 0;
1149                 *consumed_down = 0;
1150                 return 0;
1151         }
1152
1153         if (in->sw->config.depth < tunnel->dst_port->sw->config.depth) {
1154                 *consumed_up = 0;
1155                 *consumed_down = tb_dp_bandwidth(rate, lanes);
1156         } else {
1157                 *consumed_up = tb_dp_bandwidth(rate, lanes);
1158                 *consumed_down = 0;
1159         }
1160
1161         return 0;
1162 }
1163
1164 static void tb_dp_init_aux_credits(struct tb_path_hop *hop)
1165 {
1166         struct tb_port *port = hop->in_port;
1167         struct tb_switch *sw = port->sw;
1168
1169         if (tb_port_use_credit_allocation(port))
1170                 hop->initial_credits = sw->min_dp_aux_credits;
1171         else
1172                 hop->initial_credits = 1;
1173 }
1174
1175 static void tb_dp_init_aux_path(struct tb_path *path)
1176 {
1177         struct tb_path_hop *hop;
1178
1179         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1180         path->egress_shared_buffer = TB_PATH_NONE;
1181         path->ingress_fc_enable = TB_PATH_ALL;
1182         path->ingress_shared_buffer = TB_PATH_NONE;
1183         path->priority = 2;
1184         path->weight = 1;
1185
1186         tb_path_for_each_hop(path, hop)
1187                 tb_dp_init_aux_credits(hop);
1188 }
1189
1190 static int tb_dp_init_video_credits(struct tb_path_hop *hop)
1191 {
1192         struct tb_port *port = hop->in_port;
1193         struct tb_switch *sw = port->sw;
1194
1195         if (tb_port_use_credit_allocation(port)) {
1196                 unsigned int nfc_credits;
1197                 size_t max_dp_streams;
1198
1199                 tb_available_credits(port, &max_dp_streams);
1200                 /*
1201                  * Read the number of currently allocated NFC credits
1202                  * from the lane adapter. Since we only use them for DP
1203                  * tunneling we can use that to figure out how many DP
1204                  * tunnels already go through the lane adapter.
1205                  */
1206                 nfc_credits = port->config.nfc_credits &
1207                                 ADP_CS_4_NFC_BUFFERS_MASK;
1208                 if (nfc_credits / sw->min_dp_main_credits > max_dp_streams)
1209                         return -ENOSPC;
1210
1211                 hop->nfc_credits = sw->min_dp_main_credits;
1212         } else {
1213                 hop->nfc_credits = min(port->total_credits - 2, 12U);
1214         }
1215
1216         return 0;
1217 }
1218
1219 static int tb_dp_init_video_path(struct tb_path *path)
1220 {
1221         struct tb_path_hop *hop;
1222
1223         path->egress_fc_enable = TB_PATH_NONE;
1224         path->egress_shared_buffer = TB_PATH_NONE;
1225         path->ingress_fc_enable = TB_PATH_NONE;
1226         path->ingress_shared_buffer = TB_PATH_NONE;
1227         path->priority = 1;
1228         path->weight = 1;
1229
1230         tb_path_for_each_hop(path, hop) {
1231                 int ret;
1232
1233                 ret = tb_dp_init_video_credits(hop);
1234                 if (ret)
1235                         return ret;
1236         }
1237
1238         return 0;
1239 }
1240
1241 static void tb_dp_dump(struct tb_tunnel *tunnel)
1242 {
1243         struct tb_port *in, *out;
1244         u32 dp_cap, rate, lanes;
1245
1246         in = tunnel->src_port;
1247         out = tunnel->dst_port;
1248
1249         if (tb_port_read(in, &dp_cap, TB_CFG_PORT,
1250                          in->cap_adap + DP_LOCAL_CAP, 1))
1251                 return;
1252
1253         rate = tb_dp_cap_get_rate(dp_cap);
1254         lanes = tb_dp_cap_get_lanes(dp_cap);
1255
1256         tb_port_dbg(in, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
1257                     rate, lanes, tb_dp_bandwidth(rate, lanes));
1258
1259         out = tunnel->dst_port;
1260
1261         if (tb_port_read(out, &dp_cap, TB_CFG_PORT,
1262                          out->cap_adap + DP_LOCAL_CAP, 1))
1263                 return;
1264
1265         rate = tb_dp_cap_get_rate(dp_cap);
1266         lanes = tb_dp_cap_get_lanes(dp_cap);
1267
1268         tb_port_dbg(out, "maximum supported bandwidth %u Mb/s x%u = %u Mb/s\n",
1269                     rate, lanes, tb_dp_bandwidth(rate, lanes));
1270
1271         if (tb_port_read(in, &dp_cap, TB_CFG_PORT,
1272                          in->cap_adap + DP_REMOTE_CAP, 1))
1273                 return;
1274
1275         rate = tb_dp_cap_get_rate(dp_cap);
1276         lanes = tb_dp_cap_get_lanes(dp_cap);
1277
1278         tb_port_dbg(in, "reduced bandwidth %u Mb/s x%u = %u Mb/s\n",
1279                     rate, lanes, tb_dp_bandwidth(rate, lanes));
1280 }
1281
1282 /**
1283  * tb_tunnel_discover_dp() - Discover existing Display Port tunnels
1284  * @tb: Pointer to the domain structure
1285  * @in: DP in adapter
1286  * @alloc_hopid: Allocate HopIDs from visited ports
1287  *
1288  * If @in adapter is active, follows the tunnel to the DP out adapter
1289  * and back. Returns the discovered tunnel or %NULL if there was no
1290  * tunnel.
1291  *
1292  * Return: DP tunnel or %NULL if no tunnel found.
1293  */
1294 struct tb_tunnel *tb_tunnel_discover_dp(struct tb *tb, struct tb_port *in,
1295                                         bool alloc_hopid)
1296 {
1297         struct tb_tunnel *tunnel;
1298         struct tb_port *port;
1299         struct tb_path *path;
1300
1301         if (!tb_dp_port_is_enabled(in))
1302                 return NULL;
1303
1304         tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
1305         if (!tunnel)
1306                 return NULL;
1307
1308         tunnel->init = tb_dp_init;
1309         tunnel->deinit = tb_dp_deinit;
1310         tunnel->activate = tb_dp_activate;
1311         tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;
1312         tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;
1313         tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;
1314         tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
1315         tunnel->src_port = in;
1316
1317         path = tb_path_discover(in, TB_DP_VIDEO_HOPID, NULL, -1,
1318                                 &tunnel->dst_port, "Video", alloc_hopid);
1319         if (!path) {
1320                 /* Just disable the DP IN port */
1321                 tb_dp_port_enable(in, false);
1322                 goto err_free;
1323         }
1324         tunnel->paths[TB_DP_VIDEO_PATH_OUT] = path;
1325         if (tb_dp_init_video_path(tunnel->paths[TB_DP_VIDEO_PATH_OUT]))
1326                 goto err_free;
1327
1328         path = tb_path_discover(in, TB_DP_AUX_TX_HOPID, NULL, -1, NULL, "AUX TX",
1329                                 alloc_hopid);
1330         if (!path)
1331                 goto err_deactivate;
1332         tunnel->paths[TB_DP_AUX_PATH_OUT] = path;
1333         tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_OUT]);
1334
1335         path = tb_path_discover(tunnel->dst_port, -1, in, TB_DP_AUX_RX_HOPID,
1336                                 &port, "AUX RX", alloc_hopid);
1337         if (!path)
1338                 goto err_deactivate;
1339         tunnel->paths[TB_DP_AUX_PATH_IN] = path;
1340         tb_dp_init_aux_path(tunnel->paths[TB_DP_AUX_PATH_IN]);
1341
1342         /* Validate that the tunnel is complete */
1343         if (!tb_port_is_dpout(tunnel->dst_port)) {
1344                 tb_port_warn(in, "path does not end on a DP adapter, cleaning up\n");
1345                 goto err_deactivate;
1346         }
1347
1348         if (!tb_dp_port_is_enabled(tunnel->dst_port))
1349                 goto err_deactivate;
1350
1351         if (!tb_dp_port_hpd_is_active(tunnel->dst_port))
1352                 goto err_deactivate;
1353
1354         if (port != tunnel->src_port) {
1355                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
1356                 goto err_deactivate;
1357         }
1358
1359         tb_dp_dump(tunnel);
1360
1361         tb_tunnel_dbg(tunnel, "discovered\n");
1362         return tunnel;
1363
1364 err_deactivate:
1365         tb_tunnel_deactivate(tunnel);
1366 err_free:
1367         tb_tunnel_free(tunnel);
1368
1369         return NULL;
1370 }
1371
1372 /**
1373  * tb_tunnel_alloc_dp() - allocate a Display Port tunnel
1374  * @tb: Pointer to the domain structure
1375  * @in: DP in adapter port
1376  * @out: DP out adapter port
1377  * @link_nr: Preferred lane adapter when the link is not bonded
1378  * @max_up: Maximum available upstream bandwidth for the DP tunnel (%0
1379  *          if not limited)
1380  * @max_down: Maximum available downstream bandwidth for the DP tunnel
1381  *            (%0 if not limited)
1382  *
1383  * Allocates a tunnel between @in and @out that is capable of tunneling
1384  * Display Port traffic.
1385  *
1386  * Return: Returns a tb_tunnel on success or NULL on failure.
1387  */
1388 struct tb_tunnel *tb_tunnel_alloc_dp(struct tb *tb, struct tb_port *in,
1389                                      struct tb_port *out, int link_nr,
1390                                      int max_up, int max_down)
1391 {
1392         struct tb_tunnel *tunnel;
1393         struct tb_path **paths;
1394         struct tb_path *path;
1395
1396         if (WARN_ON(!in->cap_adap || !out->cap_adap))
1397                 return NULL;
1398
1399         tunnel = tb_tunnel_alloc(tb, 3, TB_TUNNEL_DP);
1400         if (!tunnel)
1401                 return NULL;
1402
1403         tunnel->init = tb_dp_init;
1404         tunnel->deinit = tb_dp_deinit;
1405         tunnel->activate = tb_dp_activate;
1406         tunnel->maximum_bandwidth = tb_dp_maximum_bandwidth;
1407         tunnel->allocated_bandwidth = tb_dp_allocated_bandwidth;
1408         tunnel->alloc_bandwidth = tb_dp_alloc_bandwidth;
1409         tunnel->consumed_bandwidth = tb_dp_consumed_bandwidth;
1410         tunnel->src_port = in;
1411         tunnel->dst_port = out;
1412         tunnel->max_up = max_up;
1413         tunnel->max_down = max_down;
1414
1415         paths = tunnel->paths;
1416
1417         path = tb_path_alloc(tb, in, TB_DP_VIDEO_HOPID, out, TB_DP_VIDEO_HOPID,
1418                              link_nr, "Video");
1419         if (!path)
1420                 goto err_free;
1421         tb_dp_init_video_path(path);
1422         paths[TB_DP_VIDEO_PATH_OUT] = path;
1423
1424         path = tb_path_alloc(tb, in, TB_DP_AUX_TX_HOPID, out,
1425                              TB_DP_AUX_TX_HOPID, link_nr, "AUX TX");
1426         if (!path)
1427                 goto err_free;
1428         tb_dp_init_aux_path(path);
1429         paths[TB_DP_AUX_PATH_OUT] = path;
1430
1431         path = tb_path_alloc(tb, out, TB_DP_AUX_RX_HOPID, in,
1432                              TB_DP_AUX_RX_HOPID, link_nr, "AUX RX");
1433         if (!path)
1434                 goto err_free;
1435         tb_dp_init_aux_path(path);
1436         paths[TB_DP_AUX_PATH_IN] = path;
1437
1438         return tunnel;
1439
1440 err_free:
1441         tb_tunnel_free(tunnel);
1442         return NULL;
1443 }
1444
1445 static unsigned int tb_dma_available_credits(const struct tb_port *port)
1446 {
1447         const struct tb_switch *sw = port->sw;
1448         int credits;
1449
1450         credits = tb_available_credits(port, NULL);
1451         if (tb_acpi_may_tunnel_pcie())
1452                 credits -= sw->max_pcie_credits;
1453         credits -= port->dma_credits;
1454
1455         return credits > 0 ? credits : 0;
1456 }
1457
1458 static int tb_dma_reserve_credits(struct tb_path_hop *hop, unsigned int credits)
1459 {
1460         struct tb_port *port = hop->in_port;
1461
1462         if (tb_port_use_credit_allocation(port)) {
1463                 unsigned int available = tb_dma_available_credits(port);
1464
1465                 /*
1466                  * Need to have at least TB_MIN_DMA_CREDITS, otherwise
1467                  * DMA path cannot be established.
1468                  */
1469                 if (available < TB_MIN_DMA_CREDITS)
1470                         return -ENOSPC;
1471
1472                 while (credits > available)
1473                         credits--;
1474
1475                 tb_port_dbg(port, "reserving %u credits for DMA path\n",
1476                             credits);
1477
1478                 port->dma_credits += credits;
1479         } else {
1480                 if (tb_port_is_null(port))
1481                         credits = port->bonded ? 14 : 6;
1482                 else
1483                         credits = min(port->total_credits, credits);
1484         }
1485
1486         hop->initial_credits = credits;
1487         return 0;
1488 }
1489
1490 /* Path from lane adapter to NHI */
1491 static int tb_dma_init_rx_path(struct tb_path *path, unsigned int credits)
1492 {
1493         struct tb_path_hop *hop;
1494         unsigned int i, tmp;
1495
1496         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1497         path->ingress_fc_enable = TB_PATH_ALL;
1498         path->egress_shared_buffer = TB_PATH_NONE;
1499         path->ingress_shared_buffer = TB_PATH_NONE;
1500         path->priority = 5;
1501         path->weight = 1;
1502         path->clear_fc = true;
1503
1504         /*
1505          * First lane adapter is the one connected to the remote host.
1506          * We don't tunnel other traffic over this link so can use all
1507          * the credits (except the ones reserved for control traffic).
1508          */
1509         hop = &path->hops[0];
1510         tmp = min(tb_usable_credits(hop->in_port), credits);
1511         hop->initial_credits = tmp;
1512         hop->in_port->dma_credits += tmp;
1513
1514         for (i = 1; i < path->path_length; i++) {
1515                 int ret;
1516
1517                 ret = tb_dma_reserve_credits(&path->hops[i], credits);
1518                 if (ret)
1519                         return ret;
1520         }
1521
1522         return 0;
1523 }
1524
1525 /* Path from NHI to lane adapter */
1526 static int tb_dma_init_tx_path(struct tb_path *path, unsigned int credits)
1527 {
1528         struct tb_path_hop *hop;
1529
1530         path->egress_fc_enable = TB_PATH_ALL;
1531         path->ingress_fc_enable = TB_PATH_ALL;
1532         path->egress_shared_buffer = TB_PATH_NONE;
1533         path->ingress_shared_buffer = TB_PATH_NONE;
1534         path->priority = 5;
1535         path->weight = 1;
1536         path->clear_fc = true;
1537
1538         tb_path_for_each_hop(path, hop) {
1539                 int ret;
1540
1541                 ret = tb_dma_reserve_credits(hop, credits);
1542                 if (ret)
1543                         return ret;
1544         }
1545
1546         return 0;
1547 }
1548
1549 static void tb_dma_release_credits(struct tb_path_hop *hop)
1550 {
1551         struct tb_port *port = hop->in_port;
1552
1553         if (tb_port_use_credit_allocation(port)) {
1554                 port->dma_credits -= hop->initial_credits;
1555
1556                 tb_port_dbg(port, "released %u DMA path credits\n",
1557                             hop->initial_credits);
1558         }
1559 }
1560
1561 static void tb_dma_deinit_path(struct tb_path *path)
1562 {
1563         struct tb_path_hop *hop;
1564
1565         tb_path_for_each_hop(path, hop)
1566                 tb_dma_release_credits(hop);
1567 }
1568
1569 static void tb_dma_deinit(struct tb_tunnel *tunnel)
1570 {
1571         int i;
1572
1573         for (i = 0; i < tunnel->npaths; i++) {
1574                 if (!tunnel->paths[i])
1575                         continue;
1576                 tb_dma_deinit_path(tunnel->paths[i]);
1577         }
1578 }
1579
1580 /**
1581  * tb_tunnel_alloc_dma() - allocate a DMA tunnel
1582  * @tb: Pointer to the domain structure
1583  * @nhi: Host controller port
1584  * @dst: Destination null port which the other domain is connected to
1585  * @transmit_path: HopID used for transmitting packets
1586  * @transmit_ring: NHI ring number used to send packets towards the
1587  *                 other domain. Set to %-1 if TX path is not needed.
1588  * @receive_path: HopID used for receiving packets
1589  * @receive_ring: NHI ring number used to receive packets from the
1590  *                other domain. Set to %-1 if RX path is not needed.
1591  *
1592  * Return: Returns a tb_tunnel on success or NULL on failure.
1593  */
1594 struct tb_tunnel *tb_tunnel_alloc_dma(struct tb *tb, struct tb_port *nhi,
1595                                       struct tb_port *dst, int transmit_path,
1596                                       int transmit_ring, int receive_path,
1597                                       int receive_ring)
1598 {
1599         struct tb_tunnel *tunnel;
1600         size_t npaths = 0, i = 0;
1601         struct tb_path *path;
1602         int credits;
1603
1604         /* Ring 0 is reserved for control channel */
1605         if (WARN_ON(!receive_ring || !transmit_ring))
1606                 return NULL;
1607
1608         if (receive_ring > 0)
1609                 npaths++;
1610         if (transmit_ring > 0)
1611                 npaths++;
1612
1613         if (WARN_ON(!npaths))
1614                 return NULL;
1615
1616         tunnel = tb_tunnel_alloc(tb, npaths, TB_TUNNEL_DMA);
1617         if (!tunnel)
1618                 return NULL;
1619
1620         tunnel->src_port = nhi;
1621         tunnel->dst_port = dst;
1622         tunnel->deinit = tb_dma_deinit;
1623
1624         credits = min_not_zero(dma_credits, nhi->sw->max_dma_credits);
1625
1626         if (receive_ring > 0) {
1627                 path = tb_path_alloc(tb, dst, receive_path, nhi, receive_ring, 0,
1628                                      "DMA RX");
1629                 if (!path)
1630                         goto err_free;
1631                 tunnel->paths[i++] = path;
1632                 if (tb_dma_init_rx_path(path, credits)) {
1633                         tb_tunnel_dbg(tunnel, "not enough buffers for RX path\n");
1634                         goto err_free;
1635                 }
1636         }
1637
1638         if (transmit_ring > 0) {
1639                 path = tb_path_alloc(tb, nhi, transmit_ring, dst, transmit_path, 0,
1640                                      "DMA TX");
1641                 if (!path)
1642                         goto err_free;
1643                 tunnel->paths[i++] = path;
1644                 if (tb_dma_init_tx_path(path, credits)) {
1645                         tb_tunnel_dbg(tunnel, "not enough buffers for TX path\n");
1646                         goto err_free;
1647                 }
1648         }
1649
1650         return tunnel;
1651
1652 err_free:
1653         tb_tunnel_free(tunnel);
1654         return NULL;
1655 }
1656
1657 /**
1658  * tb_tunnel_match_dma() - Match DMA tunnel
1659  * @tunnel: Tunnel to match
1660  * @transmit_path: HopID used for transmitting packets. Pass %-1 to ignore.
1661  * @transmit_ring: NHI ring number used to send packets towards the
1662  *                 other domain. Pass %-1 to ignore.
1663  * @receive_path: HopID used for receiving packets. Pass %-1 to ignore.
1664  * @receive_ring: NHI ring number used to receive packets from the
1665  *                other domain. Pass %-1 to ignore.
1666  *
1667  * This function can be used to match specific DMA tunnel, if there are
1668  * multiple DMA tunnels going through the same XDomain connection.
1669  * Returns true if there is match and false otherwise.
1670  */
1671 bool tb_tunnel_match_dma(const struct tb_tunnel *tunnel, int transmit_path,
1672                          int transmit_ring, int receive_path, int receive_ring)
1673 {
1674         const struct tb_path *tx_path = NULL, *rx_path = NULL;
1675         int i;
1676
1677         if (!receive_ring || !transmit_ring)
1678                 return false;
1679
1680         for (i = 0; i < tunnel->npaths; i++) {
1681                 const struct tb_path *path = tunnel->paths[i];
1682
1683                 if (!path)
1684                         continue;
1685
1686                 if (tb_port_is_nhi(path->hops[0].in_port))
1687                         tx_path = path;
1688                 else if (tb_port_is_nhi(path->hops[path->path_length - 1].out_port))
1689                         rx_path = path;
1690         }
1691
1692         if (transmit_ring > 0 || transmit_path > 0) {
1693                 if (!tx_path)
1694                         return false;
1695                 if (transmit_ring > 0 &&
1696                     (tx_path->hops[0].in_hop_index != transmit_ring))
1697                         return false;
1698                 if (transmit_path > 0 &&
1699                     (tx_path->hops[tx_path->path_length - 1].next_hop_index != transmit_path))
1700                         return false;
1701         }
1702
1703         if (receive_ring > 0 || receive_path > 0) {
1704                 if (!rx_path)
1705                         return false;
1706                 if (receive_path > 0 &&
1707                     (rx_path->hops[0].in_hop_index != receive_path))
1708                         return false;
1709                 if (receive_ring > 0 &&
1710                     (rx_path->hops[rx_path->path_length - 1].next_hop_index != receive_ring))
1711                         return false;
1712         }
1713
1714         return true;
1715 }
1716
1717 static int tb_usb3_max_link_rate(struct tb_port *up, struct tb_port *down)
1718 {
1719         int ret, up_max_rate, down_max_rate;
1720
1721         ret = usb4_usb3_port_max_link_rate(up);
1722         if (ret < 0)
1723                 return ret;
1724         up_max_rate = ret;
1725
1726         ret = usb4_usb3_port_max_link_rate(down);
1727         if (ret < 0)
1728                 return ret;
1729         down_max_rate = ret;
1730
1731         return min(up_max_rate, down_max_rate);
1732 }
1733
1734 static int tb_usb3_init(struct tb_tunnel *tunnel)
1735 {
1736         tb_tunnel_dbg(tunnel, "allocating initial bandwidth %d/%d Mb/s\n",
1737                       tunnel->allocated_up, tunnel->allocated_down);
1738
1739         return usb4_usb3_port_allocate_bandwidth(tunnel->src_port,
1740                                                  &tunnel->allocated_up,
1741                                                  &tunnel->allocated_down);
1742 }
1743
1744 static int tb_usb3_activate(struct tb_tunnel *tunnel, bool activate)
1745 {
1746         int res;
1747
1748         res = tb_usb3_port_enable(tunnel->src_port, activate);
1749         if (res)
1750                 return res;
1751
1752         if (tb_port_is_usb3_up(tunnel->dst_port))
1753                 return tb_usb3_port_enable(tunnel->dst_port, activate);
1754
1755         return 0;
1756 }
1757
1758 static int tb_usb3_consumed_bandwidth(struct tb_tunnel *tunnel,
1759                 int *consumed_up, int *consumed_down)
1760 {
1761         int pcie_enabled = tb_acpi_may_tunnel_pcie();
1762
1763         /*
1764          * PCIe tunneling, if enabled, affects the USB3 bandwidth so
1765          * take that it into account here.
1766          */
1767         *consumed_up = tunnel->allocated_up * (3 + pcie_enabled) / 3;
1768         *consumed_down = tunnel->allocated_down * (3 + pcie_enabled) / 3;
1769         return 0;
1770 }
1771
1772 static int tb_usb3_release_unused_bandwidth(struct tb_tunnel *tunnel)
1773 {
1774         int ret;
1775
1776         ret = usb4_usb3_port_release_bandwidth(tunnel->src_port,
1777                                                &tunnel->allocated_up,
1778                                                &tunnel->allocated_down);
1779         if (ret)
1780                 return ret;
1781
1782         tb_tunnel_dbg(tunnel, "decreased bandwidth allocation to %d/%d Mb/s\n",
1783                       tunnel->allocated_up, tunnel->allocated_down);
1784         return 0;
1785 }
1786
1787 static void tb_usb3_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
1788                                                 int *available_up,
1789                                                 int *available_down)
1790 {
1791         int ret, max_rate, allocate_up, allocate_down;
1792
1793         ret = usb4_usb3_port_actual_link_rate(tunnel->src_port);
1794         if (ret < 0) {
1795                 tb_tunnel_warn(tunnel, "failed to read actual link rate\n");
1796                 return;
1797         } else if (!ret) {
1798                 /* Use maximum link rate if the link valid is not set */
1799                 ret = tb_usb3_max_link_rate(tunnel->dst_port, tunnel->src_port);
1800                 if (ret < 0) {
1801                         tb_tunnel_warn(tunnel, "failed to read maximum link rate\n");
1802                         return;
1803                 }
1804         }
1805
1806         /*
1807          * 90% of the max rate can be allocated for isochronous
1808          * transfers.
1809          */
1810         max_rate = ret * 90 / 100;
1811
1812         /* No need to reclaim if already at maximum */
1813         if (tunnel->allocated_up >= max_rate &&
1814             tunnel->allocated_down >= max_rate)
1815                 return;
1816
1817         /* Don't go lower than what is already allocated */
1818         allocate_up = min(max_rate, *available_up);
1819         if (allocate_up < tunnel->allocated_up)
1820                 allocate_up = tunnel->allocated_up;
1821
1822         allocate_down = min(max_rate, *available_down);
1823         if (allocate_down < tunnel->allocated_down)
1824                 allocate_down = tunnel->allocated_down;
1825
1826         /* If no changes no need to do more */
1827         if (allocate_up == tunnel->allocated_up &&
1828             allocate_down == tunnel->allocated_down)
1829                 return;
1830
1831         ret = usb4_usb3_port_allocate_bandwidth(tunnel->src_port, &allocate_up,
1832                                                 &allocate_down);
1833         if (ret) {
1834                 tb_tunnel_info(tunnel, "failed to allocate bandwidth\n");
1835                 return;
1836         }
1837
1838         tunnel->allocated_up = allocate_up;
1839         *available_up -= tunnel->allocated_up;
1840
1841         tunnel->allocated_down = allocate_down;
1842         *available_down -= tunnel->allocated_down;
1843
1844         tb_tunnel_dbg(tunnel, "increased bandwidth allocation to %d/%d Mb/s\n",
1845                       tunnel->allocated_up, tunnel->allocated_down);
1846 }
1847
1848 static void tb_usb3_init_credits(struct tb_path_hop *hop)
1849 {
1850         struct tb_port *port = hop->in_port;
1851         struct tb_switch *sw = port->sw;
1852         unsigned int credits;
1853
1854         if (tb_port_use_credit_allocation(port)) {
1855                 credits = sw->max_usb3_credits;
1856         } else {
1857                 if (tb_port_is_null(port))
1858                         credits = port->bonded ? 32 : 16;
1859                 else
1860                         credits = 7;
1861         }
1862
1863         hop->initial_credits = credits;
1864 }
1865
1866 static void tb_usb3_init_path(struct tb_path *path)
1867 {
1868         struct tb_path_hop *hop;
1869
1870         path->egress_fc_enable = TB_PATH_SOURCE | TB_PATH_INTERNAL;
1871         path->egress_shared_buffer = TB_PATH_NONE;
1872         path->ingress_fc_enable = TB_PATH_ALL;
1873         path->ingress_shared_buffer = TB_PATH_NONE;
1874         path->priority = 3;
1875         path->weight = 3;
1876         path->drop_packages = 0;
1877
1878         tb_path_for_each_hop(path, hop)
1879                 tb_usb3_init_credits(hop);
1880 }
1881
1882 /**
1883  * tb_tunnel_discover_usb3() - Discover existing USB3 tunnels
1884  * @tb: Pointer to the domain structure
1885  * @down: USB3 downstream adapter
1886  * @alloc_hopid: Allocate HopIDs from visited ports
1887  *
1888  * If @down adapter is active, follows the tunnel to the USB3 upstream
1889  * adapter and back. Returns the discovered tunnel or %NULL if there was
1890  * no tunnel.
1891  */
1892 struct tb_tunnel *tb_tunnel_discover_usb3(struct tb *tb, struct tb_port *down,
1893                                           bool alloc_hopid)
1894 {
1895         struct tb_tunnel *tunnel;
1896         struct tb_path *path;
1897
1898         if (!tb_usb3_port_is_enabled(down))
1899                 return NULL;
1900
1901         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
1902         if (!tunnel)
1903                 return NULL;
1904
1905         tunnel->activate = tb_usb3_activate;
1906         tunnel->src_port = down;
1907
1908         /*
1909          * Discover both paths even if they are not complete. We will
1910          * clean them up by calling tb_tunnel_deactivate() below in that
1911          * case.
1912          */
1913         path = tb_path_discover(down, TB_USB3_HOPID, NULL, -1,
1914                                 &tunnel->dst_port, "USB3 Down", alloc_hopid);
1915         if (!path) {
1916                 /* Just disable the downstream port */
1917                 tb_usb3_port_enable(down, false);
1918                 goto err_free;
1919         }
1920         tunnel->paths[TB_USB3_PATH_DOWN] = path;
1921         tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_DOWN]);
1922
1923         path = tb_path_discover(tunnel->dst_port, -1, down, TB_USB3_HOPID, NULL,
1924                                 "USB3 Up", alloc_hopid);
1925         if (!path)
1926                 goto err_deactivate;
1927         tunnel->paths[TB_USB3_PATH_UP] = path;
1928         tb_usb3_init_path(tunnel->paths[TB_USB3_PATH_UP]);
1929
1930         /* Validate that the tunnel is complete */
1931         if (!tb_port_is_usb3_up(tunnel->dst_port)) {
1932                 tb_port_warn(tunnel->dst_port,
1933                              "path does not end on an USB3 adapter, cleaning up\n");
1934                 goto err_deactivate;
1935         }
1936
1937         if (down != tunnel->src_port) {
1938                 tb_tunnel_warn(tunnel, "path is not complete, cleaning up\n");
1939                 goto err_deactivate;
1940         }
1941
1942         if (!tb_usb3_port_is_enabled(tunnel->dst_port)) {
1943                 tb_tunnel_warn(tunnel,
1944                                "tunnel is not fully activated, cleaning up\n");
1945                 goto err_deactivate;
1946         }
1947
1948         if (!tb_route(down->sw)) {
1949                 int ret;
1950
1951                 /*
1952                  * Read the initial bandwidth allocation for the first
1953                  * hop tunnel.
1954                  */
1955                 ret = usb4_usb3_port_allocated_bandwidth(down,
1956                         &tunnel->allocated_up, &tunnel->allocated_down);
1957                 if (ret)
1958                         goto err_deactivate;
1959
1960                 tb_tunnel_dbg(tunnel, "currently allocated bandwidth %d/%d Mb/s\n",
1961                               tunnel->allocated_up, tunnel->allocated_down);
1962
1963                 tunnel->init = tb_usb3_init;
1964                 tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
1965                 tunnel->release_unused_bandwidth =
1966                         tb_usb3_release_unused_bandwidth;
1967                 tunnel->reclaim_available_bandwidth =
1968                         tb_usb3_reclaim_available_bandwidth;
1969         }
1970
1971         tb_tunnel_dbg(tunnel, "discovered\n");
1972         return tunnel;
1973
1974 err_deactivate:
1975         tb_tunnel_deactivate(tunnel);
1976 err_free:
1977         tb_tunnel_free(tunnel);
1978
1979         return NULL;
1980 }
1981
1982 /**
1983  * tb_tunnel_alloc_usb3() - allocate a USB3 tunnel
1984  * @tb: Pointer to the domain structure
1985  * @up: USB3 upstream adapter port
1986  * @down: USB3 downstream adapter port
1987  * @max_up: Maximum available upstream bandwidth for the USB3 tunnel (%0
1988  *          if not limited).
1989  * @max_down: Maximum available downstream bandwidth for the USB3 tunnel
1990  *            (%0 if not limited).
1991  *
1992  * Allocate an USB3 tunnel. The ports must be of type @TB_TYPE_USB3_UP and
1993  * @TB_TYPE_USB3_DOWN.
1994  *
1995  * Return: Returns a tb_tunnel on success or %NULL on failure.
1996  */
1997 struct tb_tunnel *tb_tunnel_alloc_usb3(struct tb *tb, struct tb_port *up,
1998                                        struct tb_port *down, int max_up,
1999                                        int max_down)
2000 {
2001         struct tb_tunnel *tunnel;
2002         struct tb_path *path;
2003         int max_rate = 0;
2004
2005         /*
2006          * Check that we have enough bandwidth available for the new
2007          * USB3 tunnel.
2008          */
2009         if (max_up > 0 || max_down > 0) {
2010                 max_rate = tb_usb3_max_link_rate(down, up);
2011                 if (max_rate < 0)
2012                         return NULL;
2013
2014                 /* Only 90% can be allocated for USB3 isochronous transfers */
2015                 max_rate = max_rate * 90 / 100;
2016                 tb_port_dbg(up, "required bandwidth for USB3 tunnel %d Mb/s\n",
2017                             max_rate);
2018
2019                 if (max_rate > max_up || max_rate > max_down) {
2020                         tb_port_warn(up, "not enough bandwidth for USB3 tunnel\n");
2021                         return NULL;
2022                 }
2023         }
2024
2025         tunnel = tb_tunnel_alloc(tb, 2, TB_TUNNEL_USB3);
2026         if (!tunnel)
2027                 return NULL;
2028
2029         tunnel->activate = tb_usb3_activate;
2030         tunnel->src_port = down;
2031         tunnel->dst_port = up;
2032         tunnel->max_up = max_up;
2033         tunnel->max_down = max_down;
2034
2035         path = tb_path_alloc(tb, down, TB_USB3_HOPID, up, TB_USB3_HOPID, 0,
2036                              "USB3 Down");
2037         if (!path) {
2038                 tb_tunnel_free(tunnel);
2039                 return NULL;
2040         }
2041         tb_usb3_init_path(path);
2042         tunnel->paths[TB_USB3_PATH_DOWN] = path;
2043
2044         path = tb_path_alloc(tb, up, TB_USB3_HOPID, down, TB_USB3_HOPID, 0,
2045                              "USB3 Up");
2046         if (!path) {
2047                 tb_tunnel_free(tunnel);
2048                 return NULL;
2049         }
2050         tb_usb3_init_path(path);
2051         tunnel->paths[TB_USB3_PATH_UP] = path;
2052
2053         if (!tb_route(down->sw)) {
2054                 tunnel->allocated_up = max_rate;
2055                 tunnel->allocated_down = max_rate;
2056
2057                 tunnel->init = tb_usb3_init;
2058                 tunnel->consumed_bandwidth = tb_usb3_consumed_bandwidth;
2059                 tunnel->release_unused_bandwidth =
2060                         tb_usb3_release_unused_bandwidth;
2061                 tunnel->reclaim_available_bandwidth =
2062                         tb_usb3_reclaim_available_bandwidth;
2063         }
2064
2065         return tunnel;
2066 }
2067
2068 /**
2069  * tb_tunnel_free() - free a tunnel
2070  * @tunnel: Tunnel to be freed
2071  *
2072  * Frees a tunnel. The tunnel does not need to be deactivated.
2073  */
2074 void tb_tunnel_free(struct tb_tunnel *tunnel)
2075 {
2076         int i;
2077
2078         if (!tunnel)
2079                 return;
2080
2081         if (tunnel->deinit)
2082                 tunnel->deinit(tunnel);
2083
2084         for (i = 0; i < tunnel->npaths; i++) {
2085                 if (tunnel->paths[i])
2086                         tb_path_free(tunnel->paths[i]);
2087         }
2088
2089         kfree(tunnel->paths);
2090         kfree(tunnel);
2091 }
2092
2093 /**
2094  * tb_tunnel_is_invalid - check whether an activated path is still valid
2095  * @tunnel: Tunnel to check
2096  */
2097 bool tb_tunnel_is_invalid(struct tb_tunnel *tunnel)
2098 {
2099         int i;
2100
2101         for (i = 0; i < tunnel->npaths; i++) {
2102                 WARN_ON(!tunnel->paths[i]->activated);
2103                 if (tb_path_is_invalid(tunnel->paths[i]))
2104                         return true;
2105         }
2106
2107         return false;
2108 }
2109
2110 /**
2111  * tb_tunnel_restart() - activate a tunnel after a hardware reset
2112  * @tunnel: Tunnel to restart
2113  *
2114  * Return: 0 on success and negative errno in case if failure
2115  */
2116 int tb_tunnel_restart(struct tb_tunnel *tunnel)
2117 {
2118         int res, i;
2119
2120         tb_tunnel_dbg(tunnel, "activating\n");
2121
2122         /*
2123          * Make sure all paths are properly disabled before enabling
2124          * them again.
2125          */
2126         for (i = 0; i < tunnel->npaths; i++) {
2127                 if (tunnel->paths[i]->activated) {
2128                         tb_path_deactivate(tunnel->paths[i]);
2129                         tunnel->paths[i]->activated = false;
2130                 }
2131         }
2132
2133         if (tunnel->init) {
2134                 res = tunnel->init(tunnel);
2135                 if (res)
2136                         return res;
2137         }
2138
2139         for (i = 0; i < tunnel->npaths; i++) {
2140                 res = tb_path_activate(tunnel->paths[i]);
2141                 if (res)
2142                         goto err;
2143         }
2144
2145         if (tunnel->activate) {
2146                 res = tunnel->activate(tunnel, true);
2147                 if (res)
2148                         goto err;
2149         }
2150
2151         return 0;
2152
2153 err:
2154         tb_tunnel_warn(tunnel, "activation failed\n");
2155         tb_tunnel_deactivate(tunnel);
2156         return res;
2157 }
2158
2159 /**
2160  * tb_tunnel_activate() - activate a tunnel
2161  * @tunnel: Tunnel to activate
2162  *
2163  * Return: Returns 0 on success or an error code on failure.
2164  */
2165 int tb_tunnel_activate(struct tb_tunnel *tunnel)
2166 {
2167         int i;
2168
2169         for (i = 0; i < tunnel->npaths; i++) {
2170                 if (tunnel->paths[i]->activated) {
2171                         tb_tunnel_WARN(tunnel,
2172                                        "trying to activate an already activated tunnel\n");
2173                         return -EINVAL;
2174                 }
2175         }
2176
2177         return tb_tunnel_restart(tunnel);
2178 }
2179
2180 /**
2181  * tb_tunnel_deactivate() - deactivate a tunnel
2182  * @tunnel: Tunnel to deactivate
2183  */
2184 void tb_tunnel_deactivate(struct tb_tunnel *tunnel)
2185 {
2186         int i;
2187
2188         tb_tunnel_dbg(tunnel, "deactivating\n");
2189
2190         if (tunnel->activate)
2191                 tunnel->activate(tunnel, false);
2192
2193         for (i = 0; i < tunnel->npaths; i++) {
2194                 if (tunnel->paths[i] && tunnel->paths[i]->activated)
2195                         tb_path_deactivate(tunnel->paths[i]);
2196         }
2197 }
2198
2199 /**
2200  * tb_tunnel_port_on_path() - Does the tunnel go through port
2201  * @tunnel: Tunnel to check
2202  * @port: Port to check
2203  *
2204  * Returns true if @tunnel goes through @port (direction does not matter),
2205  * false otherwise.
2206  */
2207 bool tb_tunnel_port_on_path(const struct tb_tunnel *tunnel,
2208                             const struct tb_port *port)
2209 {
2210         int i;
2211
2212         for (i = 0; i < tunnel->npaths; i++) {
2213                 if (!tunnel->paths[i])
2214                         continue;
2215
2216                 if (tb_path_port_on_path(tunnel->paths[i], port))
2217                         return true;
2218         }
2219
2220         return false;
2221 }
2222
2223 static bool tb_tunnel_is_active(const struct tb_tunnel *tunnel)
2224 {
2225         int i;
2226
2227         for (i = 0; i < tunnel->npaths; i++) {
2228                 if (!tunnel->paths[i])
2229                         return false;
2230                 if (!tunnel->paths[i]->activated)
2231                         return false;
2232         }
2233
2234         return true;
2235 }
2236
2237 /**
2238  * tb_tunnel_maximum_bandwidth() - Return maximum possible bandwidth
2239  * @tunnel: Tunnel to check
2240  * @max_up: Maximum upstream bandwidth in Mb/s
2241  * @max_down: Maximum downstream bandwidth in Mb/s
2242  *
2243  * Returns maximum possible bandwidth this tunnel can go if not limited
2244  * by other bandwidth clients. If the tunnel does not support this
2245  * returns %-EOPNOTSUPP.
2246  */
2247 int tb_tunnel_maximum_bandwidth(struct tb_tunnel *tunnel, int *max_up,
2248                                 int *max_down)
2249 {
2250         if (!tb_tunnel_is_active(tunnel))
2251                 return -EINVAL;
2252
2253         if (tunnel->maximum_bandwidth)
2254                 return tunnel->maximum_bandwidth(tunnel, max_up, max_down);
2255         return -EOPNOTSUPP;
2256 }
2257
2258 /**
2259  * tb_tunnel_allocated_bandwidth() - Return bandwidth allocated for the tunnel
2260  * @tunnel: Tunnel to check
2261  * @allocated_up: Currently allocated upstream bandwidth in Mb/s is stored here
2262  * @allocated_down: Currently allocated downstream bandwidth in Mb/s is
2263  *                  stored here
2264  *
2265  * Returns the bandwidth allocated for the tunnel. This may be higher
2266  * than what the tunnel actually consumes.
2267  */
2268 int tb_tunnel_allocated_bandwidth(struct tb_tunnel *tunnel, int *allocated_up,
2269                                   int *allocated_down)
2270 {
2271         if (!tb_tunnel_is_active(tunnel))
2272                 return -EINVAL;
2273
2274         if (tunnel->allocated_bandwidth)
2275                 return tunnel->allocated_bandwidth(tunnel, allocated_up,
2276                                                    allocated_down);
2277         return -EOPNOTSUPP;
2278 }
2279
2280 /**
2281  * tb_tunnel_alloc_bandwidth() - Change tunnel bandwidth allocation
2282  * @tunnel: Tunnel whose bandwidth allocation to change
2283  * @alloc_up: New upstream bandwidth in Mb/s
2284  * @alloc_down: New downstream bandwidth in Mb/s
2285  *
2286  * Tries to change tunnel bandwidth allocation. If succeeds returns %0
2287  * and updates @alloc_up and @alloc_down to that was actually allocated
2288  * (it may not be the same as passed originally). Returns negative errno
2289  * in case of failure.
2290  */
2291 int tb_tunnel_alloc_bandwidth(struct tb_tunnel *tunnel, int *alloc_up,
2292                               int *alloc_down)
2293 {
2294         if (!tb_tunnel_is_active(tunnel))
2295                 return -EINVAL;
2296
2297         if (tunnel->alloc_bandwidth)
2298                 return tunnel->alloc_bandwidth(tunnel, alloc_up, alloc_down);
2299
2300         return -EOPNOTSUPP;
2301 }
2302
2303 /**
2304  * tb_tunnel_consumed_bandwidth() - Return bandwidth consumed by the tunnel
2305  * @tunnel: Tunnel to check
2306  * @consumed_up: Consumed bandwidth in Mb/s from @dst_port to @src_port.
2307  *               Can be %NULL.
2308  * @consumed_down: Consumed bandwidth in Mb/s from @src_port to @dst_port.
2309  *                 Can be %NULL.
2310  *
2311  * Stores the amount of isochronous bandwidth @tunnel consumes in
2312  * @consumed_up and @consumed_down. In case of success returns %0,
2313  * negative errno otherwise.
2314  */
2315 int tb_tunnel_consumed_bandwidth(struct tb_tunnel *tunnel, int *consumed_up,
2316                                  int *consumed_down)
2317 {
2318         int up_bw = 0, down_bw = 0;
2319
2320         if (!tb_tunnel_is_active(tunnel))
2321                 goto out;
2322
2323         if (tunnel->consumed_bandwidth) {
2324                 int ret;
2325
2326                 ret = tunnel->consumed_bandwidth(tunnel, &up_bw, &down_bw);
2327                 if (ret)
2328                         return ret;
2329
2330                 tb_tunnel_dbg(tunnel, "consumed bandwidth %d/%d Mb/s\n", up_bw,
2331                               down_bw);
2332         }
2333
2334 out:
2335         if (consumed_up)
2336                 *consumed_up = up_bw;
2337         if (consumed_down)
2338                 *consumed_down = down_bw;
2339
2340         return 0;
2341 }
2342
2343 /**
2344  * tb_tunnel_release_unused_bandwidth() - Release unused bandwidth
2345  * @tunnel: Tunnel whose unused bandwidth to release
2346  *
2347  * If tunnel supports dynamic bandwidth management (USB3 tunnels at the
2348  * moment) this function makes it to release all the unused bandwidth.
2349  *
2350  * Returns %0 in case of success and negative errno otherwise.
2351  */
2352 int tb_tunnel_release_unused_bandwidth(struct tb_tunnel *tunnel)
2353 {
2354         if (!tb_tunnel_is_active(tunnel))
2355                 return 0;
2356
2357         if (tunnel->release_unused_bandwidth) {
2358                 int ret;
2359
2360                 ret = tunnel->release_unused_bandwidth(tunnel);
2361                 if (ret)
2362                         return ret;
2363         }
2364
2365         return 0;
2366 }
2367
2368 /**
2369  * tb_tunnel_reclaim_available_bandwidth() - Reclaim available bandwidth
2370  * @tunnel: Tunnel reclaiming available bandwidth
2371  * @available_up: Available upstream bandwidth (in Mb/s)
2372  * @available_down: Available downstream bandwidth (in Mb/s)
2373  *
2374  * Reclaims bandwidth from @available_up and @available_down and updates
2375  * the variables accordingly (e.g decreases both according to what was
2376  * reclaimed by the tunnel). If nothing was reclaimed the values are
2377  * kept as is.
2378  */
2379 void tb_tunnel_reclaim_available_bandwidth(struct tb_tunnel *tunnel,
2380                                            int *available_up,
2381                                            int *available_down)
2382 {
2383         if (!tb_tunnel_is_active(tunnel))
2384                 return;
2385
2386         if (tunnel->reclaim_available_bandwidth)
2387                 tunnel->reclaim_available_bandwidth(tunnel, available_up,
2388                                                     available_down);
2389 }