drivers/thunderbolt/switch.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Thunderbolt Cactus Ridge driver - switch/port utility functions
   4  *
   5  * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
   6  */
   7
   8 #include <linux/delay.h>
   9 #include <linux/idr.h>
  10 #include <linux/nvmem-provider.h>
  11 #include <linux/sizes.h>
  12 #include <linux/slab.h>
  13 #include <linux/vmalloc.h>
  14
  15 #include "tb.h"
  16
  17 /* Switch authorization from userspace is serialized by this lock */
  18 static DEFINE_MUTEX(switch_lock);
  19
  20 /* Switch NVM support */
  21
  22 #define NVM_DEVID               0x05
  23 #define NVM_VERSION             0x08
  24 #define NVM_CSS                 0x10
  25 #define NVM_FLASH_SIZE          0x45
  26
  27 #define NVM_MIN_SIZE            SZ_32K
  28 #define NVM_MAX_SIZE            SZ_512K
  29
  30 static DEFINE_IDA(nvm_ida);
  31
  32 struct nvm_auth_status {
  33         struct list_head list;
  34         uuid_t uuid;
  35         u32 status;
  36 };
  37
  38 /*
  39  * Hold NVM authentication failure status per switch This information
  40  * needs to stay around even when the switch gets power cycled so we
  41  * keep it separately.
  42  */
  43 static LIST_HEAD(nvm_auth_status_cache);
  44 static DEFINE_MUTEX(nvm_auth_status_lock);
  45
  46 static struct nvm_auth_status *__nvm_get_auth_status(const struct tb_switch *sw)
  47 {
  48         struct nvm_auth_status *st;
  49
  50         list_for_each_entry(st, &nvm_auth_status_cache, list) {
  51                 if (uuid_equal(&st->uuid, sw->uuid))
  52                         return st;
  53         }
  54
  55         return NULL;
  56 }
  57
  58 static void nvm_get_auth_status(const struct tb_switch *sw, u32 *status)
  59 {
  60         struct nvm_auth_status *st;
  61
  62         mutex_lock(&nvm_auth_status_lock);
  63         st = __nvm_get_auth_status(sw);
  64         mutex_unlock(&nvm_auth_status_lock);
  65
  66         *status = st ? st->status : 0;
  67 }
  68
  69 static void nvm_set_auth_status(const struct tb_switch *sw, u32 status)
  70 {
  71         struct nvm_auth_status *st;
  72
  73         if (WARN_ON(!sw->uuid))
  74                 return;
  75
  76         mutex_lock(&nvm_auth_status_lock);
  77         st = __nvm_get_auth_status(sw);
  78
  79         if (!st) {
  80                 st = kzalloc(sizeof(*st), GFP_KERNEL);
  81                 if (!st)
  82                         goto unlock;
  83
  84                 memcpy(&st->uuid, sw->uuid, sizeof(st->uuid));
  85                 INIT_LIST_HEAD(&st->list);
  86                 list_add_tail(&st->list, &nvm_auth_status_cache);
  87         }
  88
  89         st->status = status;
  90 unlock:
  91         mutex_unlock(&nvm_auth_status_lock);
  92 }
  93
  94 static void nvm_clear_auth_status(const struct tb_switch *sw)
  95 {
  96         struct nvm_auth_status *st;
  97
  98         mutex_lock(&nvm_auth_status_lock);
  99         st = __nvm_get_auth_status(sw);
 100         if (st) {
 101                 list_del(&st->list);
 102                 kfree(st);
 103         }
 104         mutex_unlock(&nvm_auth_status_lock);
 105 }
 106
 107 static int nvm_validate_and_write(struct tb_switch *sw)
 108 {
 109         unsigned int image_size, hdr_size;
 110         const u8 *buf = sw->nvm->buf;
 111         u16 ds_size;
 112         int ret;
 113
 114         if (!buf)
 115                 return -EINVAL;
 116
 117         image_size = sw->nvm->buf_data_size;
 118         if (image_size < NVM_MIN_SIZE || image_size > NVM_MAX_SIZE)
 119                 return -EINVAL;
 120
 121         /*
 122          * FARB pointer must point inside the image and must at least
 123          * contain parts of the digital section we will be reading here.
 124          */
 125         hdr_size = (*(u32 *)buf) & 0xffffff;
 126         if (hdr_size + NVM_DEVID + 2 >= image_size)
 127                 return -EINVAL;
 128
 129         /* Digital section start should be aligned to 4k page */
 130         if (!IS_ALIGNED(hdr_size, SZ_4K))
 131                 return -EINVAL;
 132
 133         /*
 134          * Read digital section size and check that it also fits inside
 135          * the image.
 136          */
 137         ds_size = *(u16 *)(buf + hdr_size);
 138         if (ds_size >= image_size)
 139                 return -EINVAL;
 140
 141         if (!sw->safe_mode) {
 142                 u16 device_id;
 143
 144                 /*
 145                  * Make sure the device ID in the image matches the one
 146                  * we read from the switch config space.
 147                  */
 148                 device_id = *(u16 *)(buf + hdr_size + NVM_DEVID);
 149                 if (device_id != sw->config.device_id)
 150                         return -EINVAL;
 151
 152                 if (sw->generation < 3) {
 153                         /* Write CSS headers first */
 154                         ret = dma_port_flash_write(sw->dma_port,
 155                                 DMA_PORT_CSS_ADDRESS, buf + NVM_CSS,
 156                                 DMA_PORT_CSS_MAX_SIZE);
 157                         if (ret)
 158                                 return ret;
 159                 }
 160
 161                 /* Skip headers in the image */
 162                 buf += hdr_size;
 163                 image_size -= hdr_size;
 164         }
 165
 166         return dma_port_flash_write(sw->dma_port, 0, buf, image_size);
 167 }
 168
 169 static int nvm_authenticate_host(struct tb_switch *sw)
 170 {
 171         int ret;
 172
 173         /*
 174          * Root switch NVM upgrade requires that we disconnect the
 175          * existing paths first (in case it is not in safe mode
 176          * already).
 177          */
 178         if (!sw->safe_mode) {
 179                 ret = tb_domain_disconnect_all_paths(sw->tb);
 180                 if (ret)
 181                         return ret;
 182                 /*
 183                  * The host controller goes away pretty soon after this if
 184                  * everything goes well so getting timeout is expected.
 185                  */
 186                 ret = dma_port_flash_update_auth(sw->dma_port);
 187                 return ret == -ETIMEDOUT ? 0 : ret;
 188         }
 189
 190         /*
 191          * From safe mode we can get out by just power cycling the
 192          * switch.
 193          */
 194         dma_port_power_cycle(sw->dma_port);
 195         return 0;
 196 }
 197
 198 static int nvm_authenticate_device(struct tb_switch *sw)
 199 {
 200         int ret, retries = 10;
 201
 202         ret = dma_port_flash_update_auth(sw->dma_port);
 203         if (ret && ret != -ETIMEDOUT)
 204                 return ret;
 205
 206         /*
 207          * Poll here for the authentication status. It takes some time
 208          * for the device to respond (we get timeout for a while). Once
 209          * we get response the device needs to be power cycled in order
 210          * to the new NVM to be taken into use.
 211          */
 212         do {
 213                 u32 status;
 214
 215                 ret = dma_port_flash_update_auth_status(sw->dma_port, &status);
 216                 if (ret < 0 && ret != -ETIMEDOUT)
 217                         return ret;
 218                 if (ret > 0) {
 219                         if (status) {
 220                                 tb_sw_warn(sw, "failed to authenticate NVM\n");
 221                                 nvm_set_auth_status(sw, status);
 222                         }
 223
 224                         tb_sw_info(sw, "power cycling the switch now\n");
 225                         dma_port_power_cycle(sw->dma_port);
 226                         return 0;
 227                 }
 228
 229                 msleep(500);
 230         } while (--retries);
 231
 232         return -ETIMEDOUT;
 233 }
 234
 235 static int tb_switch_nvm_read(void *priv, unsigned int offset, void *val,
 236                               size_t bytes)
 237 {
 238         struct tb_switch *sw = priv;
 239
 240         return dma_port_flash_read(sw->dma_port, offset, val, bytes);
 241 }
 242
 243 static int tb_switch_nvm_write(void *priv, unsigned int offset, void *val,
 244                                size_t bytes)
 245 {
 246         struct tb_switch *sw = priv;
 247         int ret = 0;
 248
 249         if (mutex_lock_interruptible(&switch_lock))
 250                 return -ERESTARTSYS;
 251
 252         /*
 253          * Since writing the NVM image might require some special steps,
 254          * for example when CSS headers are written, we cache the image
 255          * locally here and handle the special cases when the user asks
 256          * us to authenticate the image.
 257          */
 258         if (!sw->nvm->buf) {
 259                 sw->nvm->buf = vmalloc(NVM_MAX_SIZE);
 260                 if (!sw->nvm->buf) {
 261                         ret = -ENOMEM;
 262                         goto unlock;
 263                 }
 264         }
 265
 266         sw->nvm->buf_data_size = offset + bytes;
 267         memcpy(sw->nvm->buf + offset, val, bytes);
 268
 269 unlock:
 270         mutex_unlock(&switch_lock);
 271
 272         return ret;
 273 }
 274
 275 static struct nvmem_device *register_nvmem(struct tb_switch *sw, int id,
 276                                            size_t size, bool active)
 277 {
 278         struct nvmem_config config;
 279
 280         memset(&config, 0, sizeof(config));
 281
 282         if (active) {
 283                 config.name = "nvm_active";
 284                 config.reg_read = tb_switch_nvm_read;
 285                 config.read_only = true;
 286         } else {
 287                 config.name = "nvm_non_active";
 288                 config.reg_write = tb_switch_nvm_write;
 289                 config.root_only = true;
 290         }
 291
 292         config.id = id;
 293         config.stride = 4;
 294         config.word_size = 4;
 295         config.size = size;
 296         config.dev = &sw->dev;
 297         config.owner = THIS_MODULE;
 298         config.priv = sw;
 299
 300         return nvmem_register(&config);
 301 }
 302
 303 static int tb_switch_nvm_add(struct tb_switch *sw)
 304 {
 305         struct nvmem_device *nvm_dev;
 306         struct tb_switch_nvm *nvm;
 307         u32 val;
 308         int ret;
 309
 310         if (!sw->dma_port)
 311                 return 0;
 312
 313         nvm = kzalloc(sizeof(*nvm), GFP_KERNEL);
 314         if (!nvm)
 315                 return -ENOMEM;
 316
 317         nvm->id = ida_simple_get(&nvm_ida, 0, 0, GFP_KERNEL);
 318
 319         /*
 320          * If the switch is in safe-mode the only accessible portion of
 321          * the NVM is the non-active one where userspace is expected to
 322          * write new functional NVM.
 323          */
 324         if (!sw->safe_mode) {
 325                 u32 nvm_size, hdr_size;
 326
 327                 ret = dma_port_flash_read(sw->dma_port, NVM_FLASH_SIZE, &val,
 328                                           sizeof(val));
 329                 if (ret)
 330                         goto err_ida;
 331
 332                 hdr_size = sw->generation < 3 ? SZ_8K : SZ_16K;
 333                 nvm_size = (SZ_1M << (val & 7)) / 8;
 334                 nvm_size = (nvm_size - hdr_size) / 2;
 335
 336                 ret = dma_port_flash_read(sw->dma_port, NVM_VERSION, &val,
 337                                           sizeof(val));
 338                 if (ret)
 339                         goto err_ida;
 340
 341                 nvm->major = val >> 16;
 342                 nvm->minor = val >> 8;
 343
 344                 nvm_dev = register_nvmem(sw, nvm->id, nvm_size, true);
 345                 if (IS_ERR(nvm_dev)) {
 346                         ret = PTR_ERR(nvm_dev);
 347                         goto err_ida;
 348                 }
 349                 nvm->active = nvm_dev;
 350         }
 351
 352         nvm_dev = register_nvmem(sw, nvm->id, NVM_MAX_SIZE, false);
 353         if (IS_ERR(nvm_dev)) {
 354                 ret = PTR_ERR(nvm_dev);
 355                 goto err_nvm_active;
 356         }
 357         nvm->non_active = nvm_dev;
 358
 359         mutex_lock(&switch_lock);
 360         sw->nvm = nvm;
 361         mutex_unlock(&switch_lock);
 362
 363         return 0;
 364
 365 err_nvm_active:
 366         if (nvm->active)
 367                 nvmem_unregister(nvm->active);
 368 err_ida:
 369         ida_simple_remove(&nvm_ida, nvm->id);
 370         kfree(nvm);
 371
 372         return ret;
 373 }
 374
 375 static void tb_switch_nvm_remove(struct tb_switch *sw)
 376 {
 377         struct tb_switch_nvm *nvm;
 378
 379         mutex_lock(&switch_lock);
 380         nvm = sw->nvm;
 381         sw->nvm = NULL;
 382         mutex_unlock(&switch_lock);
 383
 384         if (!nvm)
 385                 return;
 386
 387         /* Remove authentication status in case the switch is unplugged */
 388         if (!nvm->authenticating)
 389                 nvm_clear_auth_status(sw);
 390
 391         nvmem_unregister(nvm->non_active);
 392         if (nvm->active)
 393                 nvmem_unregister(nvm->active);
 394         ida_simple_remove(&nvm_ida, nvm->id);
 395         vfree(nvm->buf);
 396         kfree(nvm);
 397 }
 398
 399 /* port utility functions */
 400
 401 static const char *tb_port_type(struct tb_regs_port_header *port)
 402 {
 403         switch (port->type >> 16) {
 404         case 0:
 405                 switch ((u8) port->type) {
 406                 case 0:
 407                         return "Inactive";
 408                 case 1:
 409                         return "Port";
 410                 case 2:
 411                         return "NHI";
 412                 default:
 413                         return "unknown";
 414                 }
 415         case 0x2:
 416                 return "Ethernet";
 417         case 0x8:
 418                 return "SATA";
 419         case 0xe:
 420                 return "DP/HDMI";
 421         case 0x10:
 422                 return "PCIe";
 423         case 0x20:
 424                 return "USB";
 425         default:
 426                 return "unknown";
 427         }
 428 }
 429
 430 static void tb_dump_port(struct tb *tb, struct tb_regs_port_header *port)
 431 {
 432         tb_info(tb,
 433                 " Port %d: %x:%x (Revision: %d, TB Version: %d, Type: %s (%#x))\n",
 434                 port->port_number, port->vendor_id, port->device_id,
 435                 port->revision, port->thunderbolt_version, tb_port_type(port),
 436                 port->type);
 437         tb_info(tb, "  Max hop id (in/out): %d/%d\n",
 438                 port->max_in_hop_id, port->max_out_hop_id);
 439         tb_info(tb, "  Max counters: %d\n", port->max_counters);
 440         tb_info(tb, "  NFC Credits: %#x\n", port->nfc_credits);
 441 }
 442
 443 /**
 444  * tb_port_state() - get connectedness state of a port
 445  *
 446  * The port must have a TB_CAP_PHY (i.e. it should be a real port).
 447  *
 448  * Return: Returns an enum tb_port_state on success or an error code on failure.
 449  */
 450 static int tb_port_state(struct tb_port *port)
 451 {
 452         struct tb_cap_phy phy;
 453         int res;
 454         if (port->cap_phy == 0) {
 455                 tb_port_WARN(port, "does not have a PHY\n");
 456                 return -EINVAL;
 457         }
 458         res = tb_port_read(port, &phy, TB_CFG_PORT, port->cap_phy, 2);
 459         if (res)
 460                 return res;
 461         return phy.state;
 462 }
 463
 464 /**
 465  * tb_wait_for_port() - wait for a port to become ready
 466  *
 467  * Wait up to 1 second for a port to reach state TB_PORT_UP. If
 468  * wait_if_unplugged is set then we also wait if the port is in state
 469  * TB_PORT_UNPLUGGED (it takes a while for the device to be registered after
 470  * switch resume). Otherwise we only wait if a device is registered but the link
 471  * has not yet been established.
 472  *
 473  * Return: Returns an error code on failure. Returns 0 if the port is not
 474  * connected or failed to reach state TB_PORT_UP within one second. Returns 1
 475  * if the port is connected and in state TB_PORT_UP.
 476  */
 477 int tb_wait_for_port(struct tb_port *port, bool wait_if_unplugged)
 478 {
 479         int retries = 10;
 480         int state;
 481         if (!port->cap_phy) {
 482                 tb_port_WARN(port, "does not have PHY\n");
 483                 return -EINVAL;
 484         }
 485         if (tb_is_upstream_port(port)) {
 486                 tb_port_WARN(port, "is the upstream port\n");
 487                 return -EINVAL;
 488         }
 489
 490         while (retries--) {
 491                 state = tb_port_state(port);
 492                 if (state < 0)
 493                         return state;
 494                 if (state == TB_PORT_DISABLED) {
 495                         tb_port_info(port, "is disabled (state: 0)\n");
 496                         return 0;
 497                 }
 498                 if (state == TB_PORT_UNPLUGGED) {
 499                         if (wait_if_unplugged) {
 500                                 /* used during resume */
 501                                 tb_port_info(port,
 502                                              "is unplugged (state: 7), retrying...\n");
 503                                 msleep(100);
 504                                 continue;
 505                         }
 506                         tb_port_info(port, "is unplugged (state: 7)\n");
 507                         return 0;
 508                 }
 509                 if (state == TB_PORT_UP) {
 510                         tb_port_info(port,
 511                                      "is connected, link is up (state: 2)\n");
 512                         return 1;
 513                 }
 514
 515                 /*
 516                  * After plug-in the state is TB_PORT_CONNECTING. Give it some
 517                  * time.
 518                  */
 519                 tb_port_info(port,
 520                              "is connected, link is not up (state: %d), retrying...\n",
 521                              state);
 522                 msleep(100);
 523         }
 524         tb_port_warn(port,
 525                      "failed to reach state TB_PORT_UP. Ignoring port...\n");
 526         return 0;
 527 }
 528
 529 /**
 530  * tb_port_add_nfc_credits() - add/remove non flow controlled credits to port
 531  *
 532  * Change the number of NFC credits allocated to @port by @credits. To remove
 533  * NFC credits pass a negative amount of credits.
 534  *
 535  * Return: Returns 0 on success or an error code on failure.
 536  */
 537 int tb_port_add_nfc_credits(struct tb_port *port, int credits)
 538 {
 539         if (credits == 0)
 540                 return 0;
 541         tb_port_info(port,
 542                      "adding %#x NFC credits (%#x -> %#x)",
 543                      credits,
 544                      port->config.nfc_credits,
 545                      port->config.nfc_credits + credits);
 546         port->config.nfc_credits += credits;
 547         return tb_port_write(port, &port->config.nfc_credits,
 548                              TB_CFG_PORT, 4, 1);
 549 }
 550
 551 /**
 552  * tb_port_clear_counter() - clear a counter in TB_CFG_COUNTER
 553  *
 554  * Return: Returns 0 on success or an error code on failure.
 555  */
 556 int tb_port_clear_counter(struct tb_port *port, int counter)
 557 {
 558         u32 zero[3] = { 0, 0, 0 };
 559         tb_port_info(port, "clearing counter %d\n", counter);
 560         return tb_port_write(port, zero, TB_CFG_COUNTERS, 3 * counter, 3);
 561 }
 562
 563 /**
 564  * tb_init_port() - initialize a port
 565  *
 566  * This is a helper method for tb_switch_alloc. Does not check or initialize
 567  * any downstream switches.
 568  *
 569  * Return: Returns 0 on success or an error code on failure.
 570  */
 571 static int tb_init_port(struct tb_port *port)
 572 {
 573         int res;
 574         int cap;
 575
 576         res = tb_port_read(port, &port->config, TB_CFG_PORT, 0, 8);
 577         if (res)
 578                 return res;
 579
 580         /* Port 0 is the switch itself and has no PHY. */
 581         if (port->config.type == TB_TYPE_PORT && port->port != 0) {
 582                 cap = tb_port_find_cap(port, TB_PORT_CAP_PHY);
 583
 584                 if (cap > 0)
 585                         port->cap_phy = cap;
 586                 else
 587                         tb_port_WARN(port, "non switch port without a PHY\n");
 588         }
 589
 590         tb_dump_port(port->sw->tb, &port->config);
 591
 592         /* TODO: Read dual link port, DP port and more from EEPROM. */
 593         return 0;
 594
 595 }
 596
 597 /* switch utility functions */
 598
 599 static void tb_dump_switch(struct tb *tb, struct tb_regs_switch_header *sw)
 600 {
 601         tb_info(tb,
 602                 " Switch: %x:%x (Revision: %d, TB Version: %d)\n",
 603                 sw->vendor_id, sw->device_id, sw->revision,
 604                 sw->thunderbolt_version);
 605         tb_info(tb, "  Max Port Number: %d\n", sw->max_port_number);
 606         tb_info(tb, "  Config:\n");
 607         tb_info(tb,
 608                 "   Upstream Port Number: %d Depth: %d Route String: %#llx Enabled: %d, PlugEventsDelay: %dms\n",
 609                 sw->upstream_port_number, sw->depth,
 610                 (((u64) sw->route_hi) << 32) | sw->route_lo,
 611                 sw->enabled, sw->plug_events_delay);
 612         tb_info(tb,
 613                 "   unknown1: %#x unknown4: %#x\n",
 614                 sw->__unknown1, sw->__unknown4);
 615 }
 616
 617 /**
 618  * reset_switch() - reconfigure route, enable and send TB_CFG_PKG_RESET
 619  *
 620  * Return: Returns 0 on success or an error code on failure.
 621  */
 622 int tb_switch_reset(struct tb *tb, u64 route)
 623 {
 624         struct tb_cfg_result res;
 625         struct tb_regs_switch_header header = {
 626                 header.route_hi = route >> 32,
 627                 header.route_lo = route,
 628                 header.enabled = true,
 629         };
 630         tb_info(tb, "resetting switch at %llx\n", route);
 631         res.err = tb_cfg_write(tb->ctl, ((u32 *) &header) + 2, route,
 632                         0, 2, 2, 2);
 633         if (res.err)
 634                 return res.err;
 635         res = tb_cfg_reset(tb->ctl, route, TB_CFG_DEFAULT_TIMEOUT);
 636         if (res.err > 0)
 637                 return -EIO;
 638         return res.err;
 639 }
 640
 641 struct tb_switch *get_switch_at_route(struct tb_switch *sw, u64 route)
 642 {
 643         u8 next_port = route; /*
 644                                * Routes use a stride of 8 bits,
 645                                * eventhough a port index has 6 bits at most.
 646                                * */
 647         if (route == 0)
 648                 return sw;
 649         if (next_port > sw->config.max_port_number)
 650                 return NULL;
 651         if (tb_is_upstream_port(&sw->ports[next_port]))
 652                 return NULL;
 653         if (!sw->ports[next_port].remote)
 654                 return NULL;
 655         return get_switch_at_route(sw->ports[next_port].remote->sw,
 656                                    route >> TB_ROUTE_SHIFT);
 657 }
 658
 659 /**
 660  * tb_plug_events_active() - enable/disable plug events on a switch
 661  *
 662  * Also configures a sane plug_events_delay of 255ms.
 663  *
 664  * Return: Returns 0 on success or an error code on failure.
 665  */
 666 static int tb_plug_events_active(struct tb_switch *sw, bool active)
 667 {
 668         u32 data;
 669         int res;
 670
 671         if (!sw->config.enabled)
 672                 return 0;
 673
 674         sw->config.plug_events_delay = 0xff;
 675         res = tb_sw_write(sw, ((u32 *) &sw->config) + 4, TB_CFG_SWITCH, 4, 1);
 676         if (res)
 677                 return res;
 678
 679         res = tb_sw_read(sw, &data, TB_CFG_SWITCH, sw->cap_plug_events + 1, 1);
 680         if (res)
 681                 return res;
 682
 683         if (active) {
 684                 data = data & 0xFFFFFF83;
 685                 switch (sw->config.device_id) {
 686                 case PCI_DEVICE_ID_INTEL_LIGHT_RIDGE:
 687                 case PCI_DEVICE_ID_INTEL_EAGLE_RIDGE:
 688                 case PCI_DEVICE_ID_INTEL_PORT_RIDGE:
 689                         break;
 690                 default:
 691                         data |= 4;
 692                 }
 693         } else {
 694                 data = data | 0x7c;
 695         }
 696         return tb_sw_write(sw, &data, TB_CFG_SWITCH,
 697                            sw->cap_plug_events + 1, 1);
 698 }
 699
 700 static ssize_t authorized_show(struct device *dev,
 701                                struct device_attribute *attr,
 702                                char *buf)
 703 {
 704         struct tb_switch *sw = tb_to_switch(dev);
 705
 706         return sprintf(buf, "%u\n", sw->authorized);
 707 }
 708
 709 static int tb_switch_set_authorized(struct tb_switch *sw, unsigned int val)
 710 {
 711         int ret = -EINVAL;
 712
 713         if (mutex_lock_interruptible(&switch_lock))
 714                 return -ERESTARTSYS;
 715
 716         if (sw->authorized)
 717                 goto unlock;
 718
 719         /*
 720          * Make sure there is no PCIe rescan ongoing when a new PCIe
 721          * tunnel is created. Otherwise the PCIe rescan code might find
 722          * the new tunnel too early.
 723          */
 724         pci_lock_rescan_remove();
 725
 726         switch (val) {
 727         /* Approve switch */
 728         case 1:
 729                 if (sw->key)
 730                         ret = tb_domain_approve_switch_key(sw->tb, sw);
 731                 else
 732                         ret = tb_domain_approve_switch(sw->tb, sw);
 733                 break;
 734
 735         /* Challenge switch */
 736         case 2:
 737                 if (sw->key)
 738                         ret = tb_domain_challenge_switch_key(sw->tb, sw);
 739                 break;
 740
 741         default:
 742                 break;
 743         }
 744
 745         pci_unlock_rescan_remove();
 746
 747         if (!ret) {
 748                 sw->authorized = val;
 749                 /* Notify status change to the userspace */
 750                 kobject_uevent(&sw->dev.kobj, KOBJ_CHANGE);
 751         }
 752
 753 unlock:
 754         mutex_unlock(&switch_lock);
 755         return ret;
 756 }
 757
 758 static ssize_t authorized_store(struct device *dev,
 759                                 struct device_attribute *attr,
 760                                 const char *buf, size_t count)
 761 {
 762         struct tb_switch *sw = tb_to_switch(dev);
 763         unsigned int val;
 764         ssize_t ret;
 765
 766         ret = kstrtouint(buf, 0, &val);
 767         if (ret)
 768                 return ret;
 769         if (val > 2)
 770                 return -EINVAL;
 771
 772         ret = tb_switch_set_authorized(sw, val);
 773
 774         return ret ? ret : count;
 775 }
 776 static DEVICE_ATTR_RW(authorized);
 777
 778 static ssize_t boot_show(struct device *dev, struct device_attribute *attr,
 779                          char *buf)
 780 {
 781         struct tb_switch *sw = tb_to_switch(dev);
 782
 783         return sprintf(buf, "%u\n", sw->boot);
 784 }
 785 static DEVICE_ATTR_RO(boot);
 786
 787 static ssize_t device_show(struct device *dev, struct device_attribute *attr,
 788                            char *buf)
 789 {
 790         struct tb_switch *sw = tb_to_switch(dev);
 791
 792         return sprintf(buf, "%#x\n", sw->device);
 793 }
 794 static DEVICE_ATTR_RO(device);
 795
 796 static ssize_t
 797 device_name_show(struct device *dev, struct device_attribute *attr, char *buf)
 798 {
 799         struct tb_switch *sw = tb_to_switch(dev);
 800
 801         return sprintf(buf, "%s\n", sw->device_name ? sw->device_name : "");
 802 }
 803 static DEVICE_ATTR_RO(device_name);
 804
 805 static ssize_t key_show(struct device *dev, struct device_attribute *attr,
 806                         char *buf)
 807 {
 808         struct tb_switch *sw = tb_to_switch(dev);
 809         ssize_t ret;
 810
 811         if (mutex_lock_interruptible(&switch_lock))
 812                 return -ERESTARTSYS;
 813
 814         if (sw->key)
 815                 ret = sprintf(buf, "%*phN\n", TB_SWITCH_KEY_SIZE, sw->key);
 816         else
 817                 ret = sprintf(buf, "\n");
 818
 819         mutex_unlock(&switch_lock);
 820         return ret;
 821 }
 822
 823 static ssize_t key_store(struct device *dev, struct device_attribute *attr,
 824                          const char *buf, size_t count)
 825 {
 826         struct tb_switch *sw = tb_to_switch(dev);
 827         u8 key[TB_SWITCH_KEY_SIZE];
 828         ssize_t ret = count;
 829         bool clear = false;
 830
 831         if (!strcmp(buf, "\n"))
 832                 clear = true;
 833         else if (hex2bin(key, buf, sizeof(key)))
 834                 return -EINVAL;
 835
 836         if (mutex_lock_interruptible(&switch_lock))
 837                 return -ERESTARTSYS;
 838
 839         if (sw->authorized) {
 840                 ret = -EBUSY;
 841         } else {
 842                 kfree(sw->key);
 843                 if (clear) {
 844                         sw->key = NULL;
 845                 } else {
 846                         sw->key = kmemdup(key, sizeof(key), GFP_KERNEL);
 847                         if (!sw->key)
 848                                 ret = -ENOMEM;
 849                 }
 850         }
 851
 852         mutex_unlock(&switch_lock);
 853         return ret;
 854 }
 855 static DEVICE_ATTR(key, 0600, key_show, key_store);
 856
 857 static ssize_t nvm_authenticate_show(struct device *dev,
 858         struct device_attribute *attr, char *buf)
 859 {
 860         struct tb_switch *sw = tb_to_switch(dev);
 861         u32 status;
 862
 863         nvm_get_auth_status(sw, &status);
 864         return sprintf(buf, "%#x\n", status);
 865 }
 866
 867 static ssize_t nvm_authenticate_store(struct device *dev,
 868         struct device_attribute *attr, const char *buf, size_t count)
 869 {
 870         struct tb_switch *sw = tb_to_switch(dev);
 871         bool val;
 872         int ret;
 873
 874         if (mutex_lock_interruptible(&switch_lock))
 875                 return -ERESTARTSYS;
 876
 877         /* If NVMem devices are not yet added */
 878         if (!sw->nvm) {
 879                 ret = -EAGAIN;
 880                 goto exit_unlock;
 881         }
 882
 883         ret = kstrtobool(buf, &val);
 884         if (ret)
 885                 goto exit_unlock;
 886
 887         /* Always clear the authentication status */
 888         nvm_clear_auth_status(sw);
 889
 890         if (val) {
 891                 ret = nvm_validate_and_write(sw);
 892                 if (ret)
 893                         goto exit_unlock;
 894
 895                 sw->nvm->authenticating = true;
 896
 897                 if (!tb_route(sw))
 898                         ret = nvm_authenticate_host(sw);
 899                 else
 900                         ret = nvm_authenticate_device(sw);
 901         }
 902
 903 exit_unlock:
 904         mutex_unlock(&switch_lock);
 905
 906         if (ret)
 907                 return ret;
 908         return count;
 909 }
 910 static DEVICE_ATTR_RW(nvm_authenticate);
 911
 912 static ssize_t nvm_version_show(struct device *dev,
 913                                 struct device_attribute *attr, char *buf)
 914 {
 915         struct tb_switch *sw = tb_to_switch(dev);
 916         int ret;
 917
 918         if (mutex_lock_interruptible(&switch_lock))
 919                 return -ERESTARTSYS;
 920
 921         if (sw->safe_mode)
 922                 ret = -ENODATA;
 923         else if (!sw->nvm)
 924                 ret = -EAGAIN;
 925         else
 926                 ret = sprintf(buf, "%x.%x\n", sw->nvm->major, sw->nvm->minor);
 927
 928         mutex_unlock(&switch_lock);
 929
 930         return ret;
 931 }
 932 static DEVICE_ATTR_RO(nvm_version);
 933
 934 static ssize_t vendor_show(struct device *dev, struct device_attribute *attr,
 935                            char *buf)
 936 {
 937         struct tb_switch *sw = tb_to_switch(dev);
 938
 939         return sprintf(buf, "%#x\n", sw->vendor);
 940 }
 941 static DEVICE_ATTR_RO(vendor);
 942
 943 static ssize_t
 944 vendor_name_show(struct device *dev, struct device_attribute *attr, char *buf)
 945 {
 946         struct tb_switch *sw = tb_to_switch(dev);
 947
 948         return sprintf(buf, "%s\n", sw->vendor_name ? sw->vendor_name : "");
 949 }
 950 static DEVICE_ATTR_RO(vendor_name);
 951
 952 static ssize_t unique_id_show(struct device *dev, struct device_attribute *attr,
 953                               char *buf)
 954 {
 955         struct tb_switch *sw = tb_to_switch(dev);
 956
 957         return sprintf(buf, "%pUb\n", sw->uuid);
 958 }
 959 static DEVICE_ATTR_RO(unique_id);
 960
 961 static struct attribute *switch_attrs[] = {
 962         &dev_attr_authorized.attr,
 963         &dev_attr_boot.attr,
 964         &dev_attr_device.attr,
 965         &dev_attr_device_name.attr,
 966         &dev_attr_key.attr,
 967         &dev_attr_nvm_authenticate.attr,
 968         &dev_attr_nvm_version.attr,
 969         &dev_attr_vendor.attr,
 970         &dev_attr_vendor_name.attr,
 971         &dev_attr_unique_id.attr,
 972         NULL,
 973 };
 974
 975 static umode_t switch_attr_is_visible(struct kobject *kobj,
 976                                       struct attribute *attr, int n)
 977 {
 978         struct device *dev = container_of(kobj, struct device, kobj);
 979         struct tb_switch *sw = tb_to_switch(dev);
 980
 981         if (attr == &dev_attr_key.attr) {
 982                 if (tb_route(sw) &&
 983                     sw->tb->security_level == TB_SECURITY_SECURE &&
 984                     sw->security_level == TB_SECURITY_SECURE)
 985                         return attr->mode;
 986                 return 0;
 987         } else if (attr == &dev_attr_nvm_authenticate.attr ||
 988                    attr == &dev_attr_nvm_version.attr) {
 989                 if (sw->dma_port)
 990                         return attr->mode;
 991                 return 0;
 992         } else if (attr == &dev_attr_boot.attr) {
 993                 if (tb_route(sw))
 994                         return attr->mode;
 995                 return 0;
 996         }
 997
 998         return sw->safe_mode ? 0 : attr->mode;
 999 }
1000
1001 static struct attribute_group switch_group = {
1002         .is_visible = switch_attr_is_visible,
1003         .attrs = switch_attrs,
1004 };
1005
1006 static const struct attribute_group *switch_groups[] = {
1007         &switch_group,
1008         NULL,
1009 };
1010
1011 static void tb_switch_release(struct device *dev)
1012 {
1013         struct tb_switch *sw = tb_to_switch(dev);
1014
1015         dma_port_free(sw->dma_port);
1016
1017         kfree(sw->uuid);
1018         kfree(sw->device_name);
1019         kfree(sw->vendor_name);
1020         kfree(sw->ports);
1021         kfree(sw->drom);
1022         kfree(sw->key);
1023         kfree(sw);
1024 }
1025
1026 struct device_type tb_switch_type = {
1027         .name = "thunderbolt_device",
1028         .release = tb_switch_release,
1029 };
1030
1031 static int tb_switch_get_generation(struct tb_switch *sw)
1032 {
1033         switch (sw->config.device_id) {
1034         case PCI_DEVICE_ID_INTEL_LIGHT_RIDGE:
1035         case PCI_DEVICE_ID_INTEL_EAGLE_RIDGE:
1036         case PCI_DEVICE_ID_INTEL_LIGHT_PEAK:
1037         case PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_2C:
1038         case PCI_DEVICE_ID_INTEL_CACTUS_RIDGE_4C:
1039         case PCI_DEVICE_ID_INTEL_PORT_RIDGE:
1040         case PCI_DEVICE_ID_INTEL_REDWOOD_RIDGE_2C_BRIDGE:
1041         case PCI_DEVICE_ID_INTEL_REDWOOD_RIDGE_4C_BRIDGE:
1042                 return 1;
1043
1044         case PCI_DEVICE_ID_INTEL_WIN_RIDGE_2C_BRIDGE:
1045         case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_2C_BRIDGE:
1046         case PCI_DEVICE_ID_INTEL_FALCON_RIDGE_4C_BRIDGE:
1047                 return 2;
1048
1049         case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_LP_BRIDGE:
1050         case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_2C_BRIDGE:
1051         case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_4C_BRIDGE:
1052         case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_2C_BRIDGE:
1053         case PCI_DEVICE_ID_INTEL_ALPINE_RIDGE_C_4C_BRIDGE:
1054         case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_2C_BRIDGE:
1055         case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_4C_BRIDGE:
1056         case PCI_DEVICE_ID_INTEL_TITAN_RIDGE_DD_BRIDGE:
1057                 return 3;
1058
1059         default:
1060                 /*
1061                  * For unknown switches assume generation to be 1 to be
1062                  * on the safe side.
1063                  */
1064                 tb_sw_warn(sw, "unsupported switch device id %#x\n",
1065                            sw->config.device_id);
1066                 return 1;
1067         }
1068 }
1069
1070 /**
1071  * tb_switch_alloc() - allocate a switch
1072  * @tb: Pointer to the owning domain
1073  * @parent: Parent device for this switch
1074  * @route: Route string for this switch
1075  *
1076  * Allocates and initializes a switch. Will not upload configuration to
1077  * the switch. For that you need to call tb_switch_configure()
1078  * separately. The returned switch should be released by calling
1079  * tb_switch_put().
1080  *
1081  * Return: Pointer to the allocated switch or %NULL in case of failure
1082  */
1083 struct tb_switch *tb_switch_alloc(struct tb *tb, struct device *parent,
1084                                   u64 route)
1085 {
1086         int i;
1087         int cap;
1088         struct tb_switch *sw;
1089         int upstream_port = tb_cfg_get_upstream_port(tb->ctl, route);
1090         if (upstream_port < 0)
1091                 return NULL;
1092
1093         sw = kzalloc(sizeof(*sw), GFP_KERNEL);
1094         if (!sw)
1095                 return NULL;
1096
1097         sw->tb = tb;
1098         if (tb_cfg_read(tb->ctl, &sw->config, route, 0, TB_CFG_SWITCH, 0, 5))
1099                 goto err_free_sw_ports;
1100
1101         tb_info(tb, "current switch config:\n");
1102         tb_dump_switch(tb, &sw->config);
1103
1104         /* configure switch */
1105         sw->config.upstream_port_number = upstream_port;
1106         sw->config.depth = tb_route_length(route);
1107         sw->config.route_lo = route;
1108         sw->config.route_hi = route >> 32;
1109         sw->config.enabled = 0;
1110
1111         /* initialize ports */
1112         sw->ports = kcalloc(sw->config.max_port_number + 1, sizeof(*sw->ports),
1113                                 GFP_KERNEL);
1114         if (!sw->ports)
1115                 goto err_free_sw_ports;
1116
1117         for (i = 0; i <= sw->config.max_port_number; i++) {
1118                 /* minimum setup for tb_find_cap and tb_drom_read to work */
1119                 sw->ports[i].sw = sw;
1120                 sw->ports[i].port = i;
1121         }
1122
1123         sw->generation = tb_switch_get_generation(sw);
1124
1125         cap = tb_switch_find_vse_cap(sw, TB_VSE_CAP_PLUG_EVENTS);
1126         if (cap < 0) {
1127                 tb_sw_warn(sw, "cannot find TB_VSE_CAP_PLUG_EVENTS aborting\n");
1128                 goto err_free_sw_ports;
1129         }
1130         sw->cap_plug_events = cap;
1131
1132         /* Root switch is always authorized */
1133         if (!route)
1134                 sw->authorized = true;
1135
1136         device_initialize(&sw->dev);
1137         sw->dev.parent = parent;
1138         sw->dev.bus = &tb_bus_type;
1139         sw->dev.type = &tb_switch_type;
1140         sw->dev.groups = switch_groups;
1141         dev_set_name(&sw->dev, "%u-%llx", tb->index, tb_route(sw));
1142
1143         return sw;
1144
1145 err_free_sw_ports:
1146         kfree(sw->ports);
1147         kfree(sw);
1148
1149         return NULL;
1150 }
1151
1152 /**
1153  * tb_switch_alloc_safe_mode() - allocate a switch that is in safe mode
1154  * @tb: Pointer to the owning domain
1155  * @parent: Parent device for this switch
1156  * @route: Route string for this switch
1157  *
1158  * This creates a switch in safe mode. This means the switch pretty much
1159  * lacks all capabilities except DMA configuration port before it is
1160  * flashed with a valid NVM firmware.
1161  *
1162  * The returned switch must be released by calling tb_switch_put().
1163  *
1164  * Return: Pointer to the allocated switch or %NULL in case of failure
1165  */
1166 struct tb_switch *
1167 tb_switch_alloc_safe_mode(struct tb *tb, struct device *parent, u64 route)
1168 {
1169         struct tb_switch *sw;
1170
1171         sw = kzalloc(sizeof(*sw), GFP_KERNEL);
1172         if (!sw)
1173                 return NULL;
1174
1175         sw->tb = tb;
1176         sw->config.depth = tb_route_length(route);
1177         sw->config.route_hi = upper_32_bits(route);
1178         sw->config.route_lo = lower_32_bits(route);
1179         sw->safe_mode = true;
1180
1181         device_initialize(&sw->dev);
1182         sw->dev.parent = parent;
1183         sw->dev.bus = &tb_bus_type;
1184         sw->dev.type = &tb_switch_type;
1185         sw->dev.groups = switch_groups;
1186         dev_set_name(&sw->dev, "%u-%llx", tb->index, tb_route(sw));
1187
1188         return sw;
1189 }
1190
1191 /**
1192  * tb_switch_configure() - Uploads configuration to the switch
1193  * @sw: Switch to configure
1194  *
1195  * Call this function before the switch is added to the system. It will
1196  * upload configuration to the switch and makes it available for the
1197  * connection manager to use.
1198  *
1199  * Return: %0 in case of success and negative errno in case of failure
1200  */
1201 int tb_switch_configure(struct tb_switch *sw)
1202 {
1203         struct tb *tb = sw->tb;
1204         u64 route;
1205         int ret;
1206
1207         route = tb_route(sw);
1208         tb_info(tb,
1209                 "initializing Switch at %#llx (depth: %d, up port: %d)\n",
1210                 route, tb_route_length(route), sw->config.upstream_port_number);
1211
1212         if (sw->config.vendor_id != PCI_VENDOR_ID_INTEL)
1213                 tb_sw_warn(sw, "unknown switch vendor id %#x\n",
1214                            sw->config.vendor_id);
1215
1216         sw->config.enabled = 1;
1217
1218         /* upload configuration */
1219         ret = tb_sw_write(sw, 1 + (u32 *)&sw->config, TB_CFG_SWITCH, 1, 3);
1220         if (ret)
1221                 return ret;
1222
1223         return tb_plug_events_active(sw, true);
1224 }
1225
1226 static void tb_switch_set_uuid(struct tb_switch *sw)
1227 {
1228         u32 uuid[4];
1229         int cap;
1230
1231         if (sw->uuid)
1232                 return;
1233
1234         /*
1235          * The newer controllers include fused UUID as part of link
1236          * controller specific registers
1237          */
1238         cap = tb_switch_find_vse_cap(sw, TB_VSE_CAP_LINK_CONTROLLER);
1239         if (cap > 0) {
1240                 tb_sw_read(sw, uuid, TB_CFG_SWITCH, cap + 3, 4);
1241         } else {
1242                 /*
1243                  * ICM generates UUID based on UID and fills the upper
1244                  * two words with ones. This is not strictly following
1245                  * UUID format but we want to be compatible with it so
1246                  * we do the same here.
1247                  */
1248                 uuid[0] = sw->uid & 0xffffffff;
1249                 uuid[1] = (sw->uid >> 32) & 0xffffffff;
1250                 uuid[2] = 0xffffffff;
1251                 uuid[3] = 0xffffffff;
1252         }
1253
1254         sw->uuid = kmemdup(uuid, sizeof(uuid), GFP_KERNEL);
1255 }
1256
1257 static int tb_switch_add_dma_port(struct tb_switch *sw)
1258 {
1259         u32 status;
1260         int ret;
1261
1262         switch (sw->generation) {
1263         case 3:
1264                 break;
1265
1266         case 2:
1267                 /* Only root switch can be upgraded */
1268                 if (tb_route(sw))
1269                         return 0;
1270                 break;
1271
1272         default:
1273                 /*
1274                  * DMA port is the only thing available when the switch
1275                  * is in safe mode.
1276                  */
1277                 if (!sw->safe_mode)
1278                         return 0;
1279                 break;
1280         }
1281
1282         if (sw->no_nvm_upgrade)
1283                 return 0;
1284
1285         sw->dma_port = dma_port_alloc(sw);
1286         if (!sw->dma_port)
1287                 return 0;
1288
1289         /*
1290          * Check status of the previous flash authentication. If there
1291          * is one we need to power cycle the switch in any case to make
1292          * it functional again.
1293          */
1294         ret = dma_port_flash_update_auth_status(sw->dma_port, &status);
1295         if (ret <= 0)
1296                 return ret;
1297
1298         if (status) {
1299                 tb_sw_info(sw, "switch flash authentication failed\n");
1300                 tb_switch_set_uuid(sw);
1301                 nvm_set_auth_status(sw, status);
1302         }
1303
1304         tb_sw_info(sw, "power cycling the switch now\n");
1305         dma_port_power_cycle(sw->dma_port);
1306
1307         /*
1308          * We return error here which causes the switch adding failure.
1309          * It should appear back after power cycle is complete.
1310          */
1311         return -ESHUTDOWN;
1312 }
1313
1314 /**
1315  * tb_switch_add() - Add a switch to the domain
1316  * @sw: Switch to add
1317  *
1318  * This is the last step in adding switch to the domain. It will read
1319  * identification information from DROM and initializes ports so that
1320  * they can be used to connect other switches. The switch will be
1321  * exposed to the userspace when this function successfully returns. To
1322  * remove and release the switch, call tb_switch_remove().
1323  *
1324  * Return: %0 in case of success and negative errno in case of failure
1325  */
1326 int tb_switch_add(struct tb_switch *sw)
1327 {
1328         int i, ret;
1329
1330         /*
1331          * Initialize DMA control port now before we read DROM. Recent
1332          * host controllers have more complete DROM on NVM that includes
1333          * vendor and model identification strings which we then expose
1334          * to the userspace. NVM can be accessed through DMA
1335          * configuration based mailbox.
1336          */
1337         ret = tb_switch_add_dma_port(sw);
1338         if (ret)
1339                 return ret;
1340
1341         if (!sw->safe_mode) {
1342                 /* read drom */
1343                 ret = tb_drom_read(sw);
1344                 if (ret) {
1345                         tb_sw_warn(sw, "tb_eeprom_read_rom failed\n");
1346                         return ret;
1347                 }
1348                 tb_sw_info(sw, "uid: %#llx\n", sw->uid);
1349
1350                 tb_switch_set_uuid(sw);
1351
1352                 for (i = 0; i <= sw->config.max_port_number; i++) {
1353                         if (sw->ports[i].disabled) {
1354                                 tb_port_info(&sw->ports[i], "disabled by eeprom\n");
1355                                 continue;
1356                         }
1357                         ret = tb_init_port(&sw->ports[i]);
1358                         if (ret)
1359                                 return ret;
1360                 }
1361         }
1362
1363         ret = device_add(&sw->dev);
1364         if (ret)
1365                 return ret;
1366
1367         ret = tb_switch_nvm_add(sw);
1368         if (ret)
1369                 device_del(&sw->dev);
1370
1371         return ret;
1372 }
1373
1374 /**
1375  * tb_switch_remove() - Remove and release a switch
1376  * @sw: Switch to remove
1377  *
1378  * This will remove the switch from the domain and release it after last
1379  * reference count drops to zero. If there are switches connected below
1380  * this switch, they will be removed as well.
1381  */
1382 void tb_switch_remove(struct tb_switch *sw)
1383 {
1384         int i;
1385
1386         /* port 0 is the switch itself and never has a remote */
1387         for (i = 1; i <= sw->config.max_port_number; i++) {
1388                 if (tb_is_upstream_port(&sw->ports[i]))
1389                         continue;
1390                 if (sw->ports[i].remote)
1391                         tb_switch_remove(sw->ports[i].remote->sw);
1392                 sw->ports[i].remote = NULL;
1393                 if (sw->ports[i].xdomain)
1394                         tb_xdomain_remove(sw->ports[i].xdomain);
1395                 sw->ports[i].xdomain = NULL;
1396         }
1397
1398         if (!sw->is_unplugged)
1399                 tb_plug_events_active(sw, false);
1400
1401         tb_switch_nvm_remove(sw);
1402         device_unregister(&sw->dev);
1403 }
1404
1405 /**
1406  * tb_sw_set_unplugged() - set is_unplugged on switch and downstream switches
1407  */
1408 void tb_sw_set_unplugged(struct tb_switch *sw)
1409 {
1410         int i;
1411         if (sw == sw->tb->root_switch) {
1412                 tb_sw_WARN(sw, "cannot unplug root switch\n");
1413                 return;
1414         }
1415         if (sw->is_unplugged) {
1416                 tb_sw_WARN(sw, "is_unplugged already set\n");
1417                 return;
1418         }
1419         sw->is_unplugged = true;
1420         for (i = 0; i <= sw->config.max_port_number; i++) {
1421                 if (!tb_is_upstream_port(&sw->ports[i]) && sw->ports[i].remote)
1422                         tb_sw_set_unplugged(sw->ports[i].remote->sw);
1423         }
1424 }
1425
1426 int tb_switch_resume(struct tb_switch *sw)
1427 {
1428         int i, err;
1429         tb_sw_info(sw, "resuming switch\n");
1430
1431         /*
1432          * Check for UID of the connected switches except for root
1433          * switch which we assume cannot be removed.
1434          */
1435         if (tb_route(sw)) {
1436                 u64 uid;
1437
1438                 err = tb_drom_read_uid_only(sw, &uid);
1439                 if (err) {
1440                         tb_sw_warn(sw, "uid read failed\n");
1441                         return err;
1442                 }
1443                 if (sw->uid != uid) {
1444                         tb_sw_info(sw,
1445                                 "changed while suspended (uid %#llx -> %#llx)\n",
1446                                 sw->uid, uid);
1447                         return -ENODEV;
1448                 }
1449         }
1450
1451         /* upload configuration */
1452         err = tb_sw_write(sw, 1 + (u32 *) &sw->config, TB_CFG_SWITCH, 1, 3);
1453         if (err)
1454                 return err;
1455
1456         err = tb_plug_events_active(sw, true);
1457         if (err)
1458                 return err;
1459
1460         /* check for surviving downstream switches */
1461         for (i = 1; i <= sw->config.max_port_number; i++) {
1462                 struct tb_port *port = &sw->ports[i];
1463                 if (tb_is_upstream_port(port))
1464                         continue;
1465                 if (!port->remote)
1466                         continue;
1467                 if (tb_wait_for_port(port, true) <= 0
1468                         || tb_switch_resume(port->remote->sw)) {
1469                         tb_port_warn(port,
1470                                      "lost during suspend, disconnecting\n");
1471                         tb_sw_set_unplugged(port->remote->sw);
1472                 }
1473         }
1474         return 0;
1475 }
1476
1477 void tb_switch_suspend(struct tb_switch *sw)
1478 {
1479         int i, err;
1480         err = tb_plug_events_active(sw, false);
1481         if (err)
1482                 return;
1483
1484         for (i = 1; i <= sw->config.max_port_number; i++) {
1485                 if (!tb_is_upstream_port(&sw->ports[i]) && sw->ports[i].remote)
1486                         tb_switch_suspend(sw->ports[i].remote->sw);
1487         }
1488         /*
1489          * TODO: invoke tb_cfg_prepare_to_sleep here? does not seem to have any
1490          * effect?
1491          */
1492 }
1493
1494 struct tb_sw_lookup {
1495         struct tb *tb;
1496         u8 link;
1497         u8 depth;
1498         const uuid_t *uuid;
1499         u64 route;
1500 };
1501
1502 static int tb_switch_match(struct device *dev, void *data)
1503 {
1504         struct tb_switch *sw = tb_to_switch(dev);
1505         struct tb_sw_lookup *lookup = data;
1506
1507         if (!sw)
1508                 return 0;
1509         if (sw->tb != lookup->tb)
1510                 return 0;
1511
1512         if (lookup->uuid)
1513                 return !memcmp(sw->uuid, lookup->uuid, sizeof(*lookup->uuid));
1514
1515         if (lookup->route) {
1516                 return sw->config.route_lo == lower_32_bits(lookup->route) &&
1517                        sw->config.route_hi == upper_32_bits(lookup->route);
1518         }
1519
1520         /* Root switch is matched only by depth */
1521         if (!lookup->depth)
1522                 return !sw->depth;
1523
1524         return sw->link == lookup->link && sw->depth == lookup->depth;
1525 }
1526
1527 /**
1528  * tb_switch_find_by_link_depth() - Find switch by link and depth
1529  * @tb: Domain the switch belongs
1530  * @link: Link number the switch is connected
1531  * @depth: Depth of the switch in link
1532  *
1533  * Returned switch has reference count increased so the caller needs to
1534  * call tb_switch_put() when done with the switch.
1535  */
1536 struct tb_switch *tb_switch_find_by_link_depth(struct tb *tb, u8 link, u8 depth)
1537 {
1538         struct tb_sw_lookup lookup;
1539         struct device *dev;
1540
1541         memset(&lookup, 0, sizeof(lookup));
1542         lookup.tb = tb;
1543         lookup.link = link;
1544         lookup.depth = depth;
1545
1546         dev = bus_find_device(&tb_bus_type, NULL, &lookup, tb_switch_match);
1547         if (dev)
1548                 return tb_to_switch(dev);
1549
1550         return NULL;
1551 }
1552
1553 /**
1554  * tb_switch_find_by_uuid() - Find switch by UUID
1555  * @tb: Domain the switch belongs
1556  * @uuid: UUID to look for
1557  *
1558  * Returned switch has reference count increased so the caller needs to
1559  * call tb_switch_put() when done with the switch.
1560  */
1561 struct tb_switch *tb_switch_find_by_uuid(struct tb *tb, const uuid_t *uuid)
1562 {
1563         struct tb_sw_lookup lookup;
1564         struct device *dev;
1565
1566         memset(&lookup, 0, sizeof(lookup));
1567         lookup.tb = tb;
1568         lookup.uuid = uuid;
1569
1570         dev = bus_find_device(&tb_bus_type, NULL, &lookup, tb_switch_match);
1571         if (dev)
1572                 return tb_to_switch(dev);
1573
1574         return NULL;
1575 }
1576
1577 /**
1578  * tb_switch_find_by_route() - Find switch by route string
1579  * @tb: Domain the switch belongs
1580  * @route: Route string to look for
1581  *
1582  * Returned switch has reference count increased so the caller needs to
1583  * call tb_switch_put() when done with the switch.
1584  */
1585 struct tb_switch *tb_switch_find_by_route(struct tb *tb, u64 route)
1586 {
1587         struct tb_sw_lookup lookup;
1588         struct device *dev;
1589
1590         if (!route)
1591                 return tb_switch_get(tb->root_switch);
1592
1593         memset(&lookup, 0, sizeof(lookup));
1594         lookup.tb = tb;
1595         lookup.route = route;
1596
1597         dev = bus_find_device(&tb_bus_type, NULL, &lookup, tb_switch_match);
1598         if (dev)
1599                 return tb_to_switch(dev);
1600
1601         return NULL;
1602 }
1603
1604 void tb_switch_exit(void)
1605 {
1606         ida_destroy(&nvm_ida);
1607 }