drivers/thunderbolt/usb4.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * USB4 specific functionality
   4  *
   5  * Copyright (C) 2019, Intel Corporation
   6  * Authors: Mika Westerberg <mika.westerberg@linux.intel.com>
   7  *          Rajmohan Mani <rajmohan.mani@intel.com>
   8  */
   9
  10 #include <linux/delay.h>
  11 #include <linux/ktime.h>
  12
  13 #include "tb.h"
  14
  15 #define USB4_DATA_DWORDS                16
  16 #define USB4_DATA_RETRIES               3
  17
  18 enum usb4_switch_op {
  19         USB4_SWITCH_OP_QUERY_DP_RESOURCE = 0x10,
  20         USB4_SWITCH_OP_ALLOC_DP_RESOURCE = 0x11,
  21         USB4_SWITCH_OP_DEALLOC_DP_RESOURCE = 0x12,
  22         USB4_SWITCH_OP_NVM_WRITE = 0x20,
  23         USB4_SWITCH_OP_NVM_AUTH = 0x21,
  24         USB4_SWITCH_OP_NVM_READ = 0x22,
  25         USB4_SWITCH_OP_NVM_SET_OFFSET = 0x23,
  26         USB4_SWITCH_OP_DROM_READ = 0x24,
  27         USB4_SWITCH_OP_NVM_SECTOR_SIZE = 0x25,
  28 };
  29
  30 #define USB4_NVM_READ_OFFSET_MASK       GENMASK(23, 2)
  31 #define USB4_NVM_READ_OFFSET_SHIFT      2
  32 #define USB4_NVM_READ_LENGTH_MASK       GENMASK(27, 24)
  33 #define USB4_NVM_READ_LENGTH_SHIFT      24
  34
  35 #define USB4_NVM_SET_OFFSET_MASK        USB4_NVM_READ_OFFSET_MASK
  36 #define USB4_NVM_SET_OFFSET_SHIFT       USB4_NVM_READ_OFFSET_SHIFT
  37
  38 #define USB4_DROM_ADDRESS_MASK          GENMASK(14, 2)
  39 #define USB4_DROM_ADDRESS_SHIFT         2
  40 #define USB4_DROM_SIZE_MASK             GENMASK(19, 15)
  41 #define USB4_DROM_SIZE_SHIFT            15
  42
  43 #define USB4_NVM_SECTOR_SIZE_MASK       GENMASK(23, 0)
  44
  45 typedef int (*read_block_fn)(struct tb_switch *, unsigned int, void *, size_t);
  46 typedef int (*write_block_fn)(struct tb_switch *, const void *, size_t);
  47
  48 static int usb4_switch_wait_for_bit(struct tb_switch *sw, u32 offset, u32 bit,
  49                                     u32 value, int timeout_msec)
  50 {
  51         ktime_t timeout = ktime_add_ms(ktime_get(), timeout_msec);
  52
  53         do {
  54                 u32 val;
  55                 int ret;
  56
  57                 ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, offset, 1);
  58                 if (ret)
  59                         return ret;
  60
  61                 if ((val & bit) == value)
  62                         return 0;
  63
  64                 usleep_range(50, 100);
  65         } while (ktime_before(ktime_get(), timeout));
  66
  67         return -ETIMEDOUT;
  68 }
  69
  70 static int usb4_switch_op_read_data(struct tb_switch *sw, void *data,
  71                                     size_t dwords)
  72 {
  73         if (dwords > USB4_DATA_DWORDS)
  74                 return -EINVAL;
  75
  76         return tb_sw_read(sw, data, TB_CFG_SWITCH, ROUTER_CS_9, dwords);
  77 }
  78
  79 static int usb4_switch_op_write_data(struct tb_switch *sw, const void *data,
  80                                      size_t dwords)
  81 {
  82         if (dwords > USB4_DATA_DWORDS)
  83                 return -EINVAL;
  84
  85         return tb_sw_write(sw, data, TB_CFG_SWITCH, ROUTER_CS_9, dwords);
  86 }
  87
  88 static int usb4_switch_op_read_metadata(struct tb_switch *sw, u32 *metadata)
  89 {
  90         return tb_sw_read(sw, metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
  91 }
  92
  93 static int usb4_switch_op_write_metadata(struct tb_switch *sw, u32 metadata)
  94 {
  95         return tb_sw_write(sw, &metadata, TB_CFG_SWITCH, ROUTER_CS_25, 1);
  96 }
  97
  98 static int usb4_switch_do_read_data(struct tb_switch *sw, u16 address,
  99         void *buf, size_t size, read_block_fn read_block)
 100 {
 101         unsigned int retries = USB4_DATA_RETRIES;
 102         unsigned int offset;
 103
 104         offset = address & 3;
 105         address = address & ~3;
 106
 107         do {
 108                 size_t nbytes = min_t(size_t, size, USB4_DATA_DWORDS * 4);
 109                 unsigned int dwaddress, dwords;
 110                 u8 data[USB4_DATA_DWORDS * 4];
 111                 int ret;
 112
 113                 dwaddress = address / 4;
 114                 dwords = ALIGN(nbytes, 4) / 4;
 115
 116                 ret = read_block(sw, dwaddress, data, dwords);
 117                 if (ret) {
 118                         if (ret == -ETIMEDOUT) {
 119                                 if (retries--)
 120                                         continue;
 121                                 ret = -EIO;
 122                         }
 123                         return ret;
 124                 }
 125
 126                 memcpy(buf, data + offset, nbytes);
 127
 128                 size -= nbytes;
 129                 address += nbytes;
 130                 buf += nbytes;
 131         } while (size > 0);
 132
 133         return 0;
 134 }
 135
 136 static int usb4_switch_do_write_data(struct tb_switch *sw, u16 address,
 137         const void *buf, size_t size, write_block_fn write_next_block)
 138 {
 139         unsigned int retries = USB4_DATA_RETRIES;
 140         unsigned int offset;
 141
 142         offset = address & 3;
 143         address = address & ~3;
 144
 145         do {
 146                 u32 nbytes = min_t(u32, size, USB4_DATA_DWORDS * 4);
 147                 u8 data[USB4_DATA_DWORDS * 4];
 148                 int ret;
 149
 150                 memcpy(data + offset, buf, nbytes);
 151
 152                 ret = write_next_block(sw, data, nbytes / 4);
 153                 if (ret) {
 154                         if (ret == -ETIMEDOUT) {
 155                                 if (retries--)
 156                                         continue;
 157                                 ret = -EIO;
 158                         }
 159                         return ret;
 160                 }
 161
 162                 size -= nbytes;
 163                 address += nbytes;
 164                 buf += nbytes;
 165         } while (size > 0);
 166
 167         return 0;
 168 }
 169
 170 static int usb4_switch_op(struct tb_switch *sw, u16 opcode, u8 *status)
 171 {
 172         u32 val;
 173         int ret;
 174
 175         val = opcode | ROUTER_CS_26_OV;
 176         ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
 177         if (ret)
 178                 return ret;
 179
 180         ret = usb4_switch_wait_for_bit(sw, ROUTER_CS_26, ROUTER_CS_26_OV, 0, 500);
 181         if (ret)
 182                 return ret;
 183
 184         ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_26, 1);
 185         if (val & ROUTER_CS_26_ONS)
 186                 return -EOPNOTSUPP;
 187
 188         *status = (val & ROUTER_CS_26_STATUS_MASK) >> ROUTER_CS_26_STATUS_SHIFT;
 189         return 0;
 190 }
 191
 192 /**
 193  * usb4_switch_setup() - Additional setup for USB4 device
 194  * @sw: USB4 router to setup
 195  *
 196  * USB4 routers need additional settings in order to enable all the
 197  * tunneling. This function enables USB and PCIe tunneling if it can be
 198  * enabled (e.g the parent switch also supports them). If USB tunneling
 199  * is not available for some reason (like that there is Thunderbolt 3
 200  * switch upstream) then the internal xHCI controller is enabled
 201  * instead.
 202  */
 203 int usb4_switch_setup(struct tb_switch *sw)
 204 {
 205         struct tb_switch *parent;
 206         bool tbt3, xhci;
 207         u32 val = 0;
 208         int ret;
 209
 210         if (!tb_route(sw))
 211                 return 0;
 212
 213         ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_6, 1);
 214         if (ret)
 215                 return ret;
 216
 217         xhci = val & ROUTER_CS_6_HCI;
 218         tbt3 = !(val & ROUTER_CS_6_TNS);
 219
 220         tb_sw_dbg(sw, "TBT3 support: %s, xHCI: %s\n",
 221                   tbt3 ? "yes" : "no", xhci ? "yes" : "no");
 222
 223         ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
 224         if (ret)
 225                 return ret;
 226
 227         parent = tb_switch_parent(sw);
 228
 229         if (tb_switch_find_port(parent, TB_TYPE_USB3_DOWN)) {
 230                 val |= ROUTER_CS_5_UTO;
 231                 xhci = false;
 232         }
 233
 234         /* Only enable PCIe tunneling if the parent router supports it */
 235         if (tb_switch_find_port(parent, TB_TYPE_PCIE_DOWN)) {
 236                 val |= ROUTER_CS_5_PTO;
 237                 /*
 238                  * xHCI can be enabled if PCIe tunneling is supported
 239                  * and the parent does not have any USB3 dowstream
 240                  * adapters (so we cannot do USB 3.x tunneling).
 241                  */
 242                 if (xhci)
 243                         val |= ROUTER_CS_5_HCO;
 244         }
 245
 246         /* TBT3 supported by the CM */
 247         val |= ROUTER_CS_5_C3S;
 248         /* Tunneling configuration is ready now */
 249         val |= ROUTER_CS_5_CV;
 250
 251         ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
 252         if (ret)
 253                 return ret;
 254
 255         return usb4_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_CR,
 256                                         ROUTER_CS_6_CR, 50);
 257 }
 258
 259 /**
 260  * usb4_switch_read_uid() - Read UID from USB4 router
 261  * @sw: USB4 router
 262  * @uid: UID is stored here
 263  *
 264  * Reads 64-bit UID from USB4 router config space.
 265  */
 266 int usb4_switch_read_uid(struct tb_switch *sw, u64 *uid)
 267 {
 268         return tb_sw_read(sw, uid, TB_CFG_SWITCH, ROUTER_CS_7, 2);
 269 }
 270
 271 static int usb4_switch_drom_read_block(struct tb_switch *sw,
 272                                        unsigned int dwaddress, void *buf,
 273                                        size_t dwords)
 274 {
 275         u8 status = 0;
 276         u32 metadata;
 277         int ret;
 278
 279         metadata = (dwords << USB4_DROM_SIZE_SHIFT) & USB4_DROM_SIZE_MASK;
 280         metadata |= (dwaddress << USB4_DROM_ADDRESS_SHIFT) &
 281                 USB4_DROM_ADDRESS_MASK;
 282
 283         ret = usb4_switch_op_write_metadata(sw, metadata);
 284         if (ret)
 285                 return ret;
 286
 287         ret = usb4_switch_op(sw, USB4_SWITCH_OP_DROM_READ, &status);
 288         if (ret)
 289                 return ret;
 290
 291         if (status)
 292                 return -EIO;
 293
 294         return usb4_switch_op_read_data(sw, buf, dwords);
 295 }
 296
 297 /**
 298  * usb4_switch_drom_read() - Read arbitrary bytes from USB4 router DROM
 299  * @sw: USB4 router
 300  * @address: Byte address inside DROM to start reading
 301  * @buf: Buffer where the DROM content is stored
 302  * @size: Number of bytes to read from DROM
 303  *
 304  * Uses USB4 router operations to read router DROM. For devices this
 305  * should always work but for hosts it may return %-EOPNOTSUPP in which
 306  * case the host router does not have DROM.
 307  */
 308 int usb4_switch_drom_read(struct tb_switch *sw, unsigned int address, void *buf,
 309                           size_t size)
 310 {
 311         return usb4_switch_do_read_data(sw, address, buf, size,
 312                                         usb4_switch_drom_read_block);
 313 }
 314
 315 static int usb4_set_port_configured(struct tb_port *port, bool configured)
 316 {
 317         int ret;
 318         u32 val;
 319
 320         ret = tb_port_read(port, &val, TB_CFG_PORT,
 321                            port->cap_usb4 + PORT_CS_19, 1);
 322         if (ret)
 323                 return ret;
 324
 325         if (configured)
 326                 val |= PORT_CS_19_PC;
 327         else
 328                 val &= ~PORT_CS_19_PC;
 329
 330         return tb_port_write(port, &val, TB_CFG_PORT,
 331                              port->cap_usb4 + PORT_CS_19, 1);
 332 }
 333
 334 /**
 335  * usb4_switch_configure_link() - Set upstream USB4 link configured
 336  * @sw: USB4 router
 337  *
 338  * Sets the upstream USB4 link to be configured for power management
 339  * purposes.
 340  */
 341 int usb4_switch_configure_link(struct tb_switch *sw)
 342 {
 343         struct tb_port *up;
 344
 345         if (!tb_route(sw))
 346                 return 0;
 347
 348         up = tb_upstream_port(sw);
 349         return usb4_set_port_configured(up, true);
 350 }
 351
 352 /**
 353  * usb4_switch_unconfigure_link() - Un-set upstream USB4 link configuration
 354  * @sw: USB4 router
 355  *
 356  * Reverse of usb4_switch_configure_link().
 357  */
 358 void usb4_switch_unconfigure_link(struct tb_switch *sw)
 359 {
 360         struct tb_port *up;
 361
 362         if (sw->is_unplugged || !tb_route(sw))
 363                 return;
 364
 365         up = tb_upstream_port(sw);
 366         usb4_set_port_configured(up, false);
 367 }
 368
 369 /**
 370  * usb4_switch_lane_bonding_possible() - Are conditions met for lane bonding
 371  * @sw: USB4 router
 372  *
 373  * Checks whether conditions are met so that lane bonding can be
 374  * established with the upstream router. Call only for device routers.
 375  */
 376 bool usb4_switch_lane_bonding_possible(struct tb_switch *sw)
 377 {
 378         struct tb_port *up;
 379         int ret;
 380         u32 val;
 381
 382         up = tb_upstream_port(sw);
 383         ret = tb_port_read(up, &val, TB_CFG_PORT, up->cap_usb4 + PORT_CS_18, 1);
 384         if (ret)
 385                 return false;
 386
 387         return !!(val & PORT_CS_18_BE);
 388 }
 389
 390 /**
 391  * usb4_switch_set_sleep() - Prepare the router to enter sleep
 392  * @sw: USB4 router
 393  *
 394  * Enables wakes and sets sleep bit for the router. Returns when the
 395  * router sleep ready bit has been asserted.
 396  */
 397 int usb4_switch_set_sleep(struct tb_switch *sw)
 398 {
 399         int ret;
 400         u32 val;
 401
 402         /* Set sleep bit and wait for sleep ready to be asserted */
 403         ret = tb_sw_read(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
 404         if (ret)
 405                 return ret;
 406
 407         val |= ROUTER_CS_5_SLP;
 408
 409         ret = tb_sw_write(sw, &val, TB_CFG_SWITCH, ROUTER_CS_5, 1);
 410         if (ret)
 411                 return ret;
 412
 413         return usb4_switch_wait_for_bit(sw, ROUTER_CS_6, ROUTER_CS_6_SLPR,
 414                                         ROUTER_CS_6_SLPR, 500);
 415 }
 416
 417 /**
 418  * usb4_switch_nvm_sector_size() - Return router NVM sector size
 419  * @sw: USB4 router
 420  *
 421  * If the router supports NVM operations this function returns the NVM
 422  * sector size in bytes. If NVM operations are not supported returns
 423  * %-EOPNOTSUPP.
 424  */
 425 int usb4_switch_nvm_sector_size(struct tb_switch *sw)
 426 {
 427         u32 metadata;
 428         u8 status;
 429         int ret;
 430
 431         ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SECTOR_SIZE, &status);
 432         if (ret)
 433                 return ret;
 434
 435         if (status)
 436                 return status == 0x2 ? -EOPNOTSUPP : -EIO;
 437
 438         ret = usb4_switch_op_read_metadata(sw, &metadata);
 439         if (ret)
 440                 return ret;
 441
 442         return metadata & USB4_NVM_SECTOR_SIZE_MASK;
 443 }
 444
 445 static int usb4_switch_nvm_read_block(struct tb_switch *sw,
 446         unsigned int dwaddress, void *buf, size_t dwords)
 447 {
 448         u8 status = 0;
 449         u32 metadata;
 450         int ret;
 451
 452         metadata = (dwords << USB4_NVM_READ_LENGTH_SHIFT) &
 453                    USB4_NVM_READ_LENGTH_MASK;
 454         metadata |= (dwaddress << USB4_NVM_READ_OFFSET_SHIFT) &
 455                    USB4_NVM_READ_OFFSET_MASK;
 456
 457         ret = usb4_switch_op_write_metadata(sw, metadata);
 458         if (ret)
 459                 return ret;
 460
 461         ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_READ, &status);
 462         if (ret)
 463                 return ret;
 464
 465         if (status)
 466                 return -EIO;
 467
 468         return usb4_switch_op_read_data(sw, buf, dwords);
 469 }
 470
 471 /**
 472  * usb4_switch_nvm_read() - Read arbitrary bytes from router NVM
 473  * @sw: USB4 router
 474  * @address: Starting address in bytes
 475  * @buf: Read data is placed here
 476  * @size: How many bytes to read
 477  *
 478  * Reads NVM contents of the router. If NVM is not supported returns
 479  * %-EOPNOTSUPP.
 480  */
 481 int usb4_switch_nvm_read(struct tb_switch *sw, unsigned int address, void *buf,
 482                          size_t size)
 483 {
 484         return usb4_switch_do_read_data(sw, address, buf, size,
 485                                         usb4_switch_nvm_read_block);
 486 }
 487
 488 static int usb4_switch_nvm_set_offset(struct tb_switch *sw,
 489                                       unsigned int address)
 490 {
 491         u32 metadata, dwaddress;
 492         u8 status = 0;
 493         int ret;
 494
 495         dwaddress = address / 4;
 496         metadata = (dwaddress << USB4_NVM_SET_OFFSET_SHIFT) &
 497                    USB4_NVM_SET_OFFSET_MASK;
 498
 499         ret = usb4_switch_op_write_metadata(sw, metadata);
 500         if (ret)
 501                 return ret;
 502
 503         ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_SET_OFFSET, &status);
 504         if (ret)
 505                 return ret;
 506
 507         return status ? -EIO : 0;
 508 }
 509
 510 static int usb4_switch_nvm_write_next_block(struct tb_switch *sw,
 511                                             const void *buf, size_t dwords)
 512 {
 513         u8 status;
 514         int ret;
 515
 516         ret = usb4_switch_op_write_data(sw, buf, dwords);
 517         if (ret)
 518                 return ret;
 519
 520         ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_WRITE, &status);
 521         if (ret)
 522                 return ret;
 523
 524         return status ? -EIO : 0;
 525 }
 526
 527 /**
 528  * usb4_switch_nvm_write() - Write to the router NVM
 529  * @sw: USB4 router
 530  * @address: Start address where to write in bytes
 531  * @buf: Pointer to the data to write
 532  * @size: Size of @buf in bytes
 533  *
 534  * Writes @buf to the router NVM using USB4 router operations. If NVM
 535  * write is not supported returns %-EOPNOTSUPP.
 536  */
 537 int usb4_switch_nvm_write(struct tb_switch *sw, unsigned int address,
 538                           const void *buf, size_t size)
 539 {
 540         int ret;
 541
 542         ret = usb4_switch_nvm_set_offset(sw, address);
 543         if (ret)
 544                 return ret;
 545
 546         return usb4_switch_do_write_data(sw, address, buf, size,
 547                                          usb4_switch_nvm_write_next_block);
 548 }
 549
 550 /**
 551  * usb4_switch_nvm_authenticate() - Authenticate new NVM
 552  * @sw: USB4 router
 553  *
 554  * After the new NVM has been written via usb4_switch_nvm_write(), this
 555  * function triggers NVM authentication process. If the authentication
 556  * is successful the router is power cycled and the new NVM starts
 557  * running. In case of failure returns negative errno.
 558  */
 559 int usb4_switch_nvm_authenticate(struct tb_switch *sw)
 560 {
 561         u8 status = 0;
 562         int ret;
 563
 564         ret = usb4_switch_op(sw, USB4_SWITCH_OP_NVM_AUTH, &status);
 565         if (ret)
 566                 return ret;
 567
 568         switch (status) {
 569         case 0x0:
 570                 tb_sw_dbg(sw, "NVM authentication successful\n");
 571                 return 0;
 572         case 0x1:
 573                 return -EINVAL;
 574         case 0x2:
 575                 return -EAGAIN;
 576         case 0x3:
 577                 return -EOPNOTSUPP;
 578         default:
 579                 return -EIO;
 580         }
 581 }
 582
 583 /**
 584  * usb4_switch_query_dp_resource() - Query availability of DP IN resource
 585  * @sw: USB4 router
 586  * @in: DP IN adapter
 587  *
 588  * For DP tunneling this function can be used to query availability of
 589  * DP IN resource. Returns true if the resource is available for DP
 590  * tunneling, false otherwise.
 591  */
 592 bool usb4_switch_query_dp_resource(struct tb_switch *sw, struct tb_port *in)
 593 {
 594         u8 status;
 595         int ret;
 596
 597         ret = usb4_switch_op_write_metadata(sw, in->port);
 598         if (ret)
 599                 return false;
 600
 601         ret = usb4_switch_op(sw, USB4_SWITCH_OP_QUERY_DP_RESOURCE, &status);
 602         /*
 603          * If DP resource allocation is not supported assume it is
 604          * always available.
 605          */
 606         if (ret == -EOPNOTSUPP)
 607                 return true;
 608         else if (ret)
 609                 return false;
 610
 611         return !status;
 612 }
 613
 614 /**
 615  * usb4_switch_alloc_dp_resource() - Allocate DP IN resource
 616  * @sw: USB4 router
 617  * @in: DP IN adapter
 618  *
 619  * Allocates DP IN resource for DP tunneling using USB4 router
 620  * operations. If the resource was allocated returns %0. Otherwise
 621  * returns negative errno, in particular %-EBUSY if the resource is
 622  * already allocated.
 623  */
 624 int usb4_switch_alloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
 625 {
 626         u8 status;
 627         int ret;
 628
 629         ret = usb4_switch_op_write_metadata(sw, in->port);
 630         if (ret)
 631                 return ret;
 632
 633         ret = usb4_switch_op(sw, USB4_SWITCH_OP_ALLOC_DP_RESOURCE, &status);
 634         if (ret == -EOPNOTSUPP)
 635                 return 0;
 636         else if (ret)
 637                 return ret;
 638
 639         return status ? -EBUSY : 0;
 640 }
 641
 642 /**
 643  * usb4_switch_dealloc_dp_resource() - Releases allocated DP IN resource
 644  * @sw: USB4 router
 645  * @in: DP IN adapter
 646  *
 647  * Releases the previously allocated DP IN resource.
 648  */
 649 int usb4_switch_dealloc_dp_resource(struct tb_switch *sw, struct tb_port *in)
 650 {
 651         u8 status;
 652         int ret;
 653
 654         ret = usb4_switch_op_write_metadata(sw, in->port);
 655         if (ret)
 656                 return ret;
 657
 658         ret = usb4_switch_op(sw, USB4_SWITCH_OP_DEALLOC_DP_RESOURCE, &status);
 659         if (ret == -EOPNOTSUPP)
 660                 return 0;
 661         else if (ret)
 662                 return ret;
 663
 664         return status ? -EIO : 0;
 665 }
 666
 667 static int usb4_port_idx(const struct tb_switch *sw, const struct tb_port *port)
 668 {
 669         struct tb_port *p;
 670         int usb4_idx = 0;
 671
 672         /* Assume port is primary */
 673         tb_switch_for_each_port(sw, p) {
 674                 if (!tb_port_is_null(p))
 675                         continue;
 676                 if (tb_is_upstream_port(p))
 677                         continue;
 678                 if (!p->link_nr) {
 679                         if (p == port)
 680                                 break;
 681                         usb4_idx++;
 682                 }
 683         }
 684
 685         return usb4_idx;
 686 }
 687
 688 /**
 689  * usb4_switch_map_pcie_down() - Map USB4 port to a PCIe downstream adapter
 690  * @sw: USB4 router
 691  * @port: USB4 port
 692  *
 693  * USB4 routers have direct mapping between USB4 ports and PCIe
 694  * downstream adapters where the PCIe topology is extended. This
 695  * function returns the corresponding downstream PCIe adapter or %NULL
 696  * if no such mapping was possible.
 697  */
 698 struct tb_port *usb4_switch_map_pcie_down(struct tb_switch *sw,
 699                                           const struct tb_port *port)
 700 {
 701         int usb4_idx = usb4_port_idx(sw, port);
 702         struct tb_port *p;
 703         int pcie_idx = 0;
 704
 705         /* Find PCIe down port matching usb4_port */
 706         tb_switch_for_each_port(sw, p) {
 707                 if (!tb_port_is_pcie_down(p))
 708                         continue;
 709
 710                 if (pcie_idx == usb4_idx && !tb_pci_port_is_enabled(p))
 711                         return p;
 712
 713                 pcie_idx++;
 714         }
 715
 716         return NULL;
 717 }
 718
 719 /**
 720  * usb4_switch_map_usb3_down() - Map USB4 port to a USB3 downstream adapter
 721  * @sw: USB4 router
 722  * @port: USB4 port
 723  *
 724  * USB4 routers have direct mapping between USB4 ports and USB 3.x
 725  * downstream adapters where the USB 3.x topology is extended. This
 726  * function returns the corresponding downstream USB 3.x adapter or
 727  * %NULL if no such mapping was possible.
 728  */
 729 struct tb_port *usb4_switch_map_usb3_down(struct tb_switch *sw,
 730                                           const struct tb_port *port)
 731 {
 732         int usb4_idx = usb4_port_idx(sw, port);
 733         struct tb_port *p;
 734         int usb_idx = 0;
 735
 736         /* Find USB3 down port matching usb4_port */
 737         tb_switch_for_each_port(sw, p) {
 738                 if (!tb_port_is_usb3_down(p))
 739                         continue;
 740
 741                 if (usb_idx == usb4_idx && !tb_usb3_port_is_enabled(p))
 742                         return p;
 743
 744                 usb_idx++;
 745         }
 746
 747         return NULL;
 748 }
 749
 750 /**
 751  * usb4_port_unlock() - Unlock USB4 downstream port
 752  * @port: USB4 port to unlock
 753  *
 754  * Unlocks USB4 downstream port so that the connection manager can
 755  * access the router below this port.
 756  */
 757 int usb4_port_unlock(struct tb_port *port)
 758 {
 759         int ret;
 760         u32 val;
 761
 762         ret = tb_port_read(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
 763         if (ret)
 764                 return ret;
 765
 766         val &= ~ADP_CS_4_LCK;
 767         return tb_port_write(port, &val, TB_CFG_PORT, ADP_CS_4, 1);
 768 }