drivers/thunderbolt/domain.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Thunderbolt bus support
   4  *
   5  * Copyright (C) 2017, Intel Corporation
   6  * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
   7  */
   8
   9 #include <linux/device.h>
  10 #include <linux/idr.h>
  11 #include <linux/module.h>
  12 #include <linux/pm_runtime.h>
  13 #include <linux/slab.h>
  14 #include <linux/random.h>
  15 #include <crypto/hash.h>
  16
  17 #include "tb.h"
  18
  19 static DEFINE_IDA(tb_domain_ida);
  20
  21 static bool match_service_id(const struct tb_service_id *id,
  22                              const struct tb_service *svc)
  23 {
  24         if (id->match_flags & TBSVC_MATCH_PROTOCOL_KEY) {
  25                 if (strcmp(id->protocol_key, svc->key))
  26                         return false;
  27         }
  28
  29         if (id->match_flags & TBSVC_MATCH_PROTOCOL_ID) {
  30                 if (id->protocol_id != svc->prtcid)
  31                         return false;
  32         }
  33
  34         if (id->match_flags & TBSVC_MATCH_PROTOCOL_VERSION) {
  35                 if (id->protocol_version != svc->prtcvers)
  36                         return false;
  37         }
  38
  39         if (id->match_flags & TBSVC_MATCH_PROTOCOL_VERSION) {
  40                 if (id->protocol_revision != svc->prtcrevs)
  41                         return false;
  42         }
  43
  44         return true;
  45 }
  46
  47 static const struct tb_service_id *__tb_service_match(struct device *dev,
  48                                                       struct device_driver *drv)
  49 {
  50         struct tb_service_driver *driver;
  51         const struct tb_service_id *ids;
  52         struct tb_service *svc;
  53
  54         svc = tb_to_service(dev);
  55         if (!svc)
  56                 return NULL;
  57
  58         driver = container_of(drv, struct tb_service_driver, driver);
  59         if (!driver->id_table)
  60                 return NULL;
  61
  62         for (ids = driver->id_table; ids->match_flags != 0; ids++) {
  63                 if (match_service_id(ids, svc))
  64                         return ids;
  65         }
  66
  67         return NULL;
  68 }
  69
  70 static int tb_service_match(struct device *dev, struct device_driver *drv)
  71 {
  72         return !!__tb_service_match(dev, drv);
  73 }
  74
  75 static int tb_service_probe(struct device *dev)
  76 {
  77         struct tb_service *svc = tb_to_service(dev);
  78         struct tb_service_driver *driver;
  79         const struct tb_service_id *id;
  80
  81         driver = container_of(dev->driver, struct tb_service_driver, driver);
  82         id = __tb_service_match(dev, &driver->driver);
  83
  84         return driver->probe(svc, id);
  85 }
  86
  87 static void tb_service_remove(struct device *dev)
  88 {
  89         struct tb_service *svc = tb_to_service(dev);
  90         struct tb_service_driver *driver;
  91
  92         driver = container_of(dev->driver, struct tb_service_driver, driver);
  93         if (driver->remove)
  94                 driver->remove(svc);
  95 }
  96
  97 static void tb_service_shutdown(struct device *dev)
  98 {
  99         struct tb_service_driver *driver;
 100         struct tb_service *svc;
 101
 102         svc = tb_to_service(dev);
 103         if (!svc || !dev->driver)
 104                 return;
 105
 106         driver = container_of(dev->driver, struct tb_service_driver, driver);
 107         if (driver->shutdown)
 108                 driver->shutdown(svc);
 109 }
 110
 111 static const char * const tb_security_names[] = {
 112         [TB_SECURITY_NONE] = "none",
 113         [TB_SECURITY_USER] = "user",
 114         [TB_SECURITY_SECURE] = "secure",
 115         [TB_SECURITY_DPONLY] = "dponly",
 116         [TB_SECURITY_USBONLY] = "usbonly",
 117         [TB_SECURITY_NOPCIE] = "nopcie",
 118 };
 119
 120 static ssize_t boot_acl_show(struct device *dev, struct device_attribute *attr,
 121                              char *buf)
 122 {
 123         struct tb *tb = container_of(dev, struct tb, dev);
 124         uuid_t *uuids;
 125         ssize_t ret;
 126         int i;
 127
 128         uuids = kcalloc(tb->nboot_acl, sizeof(uuid_t), GFP_KERNEL);
 129         if (!uuids)
 130                 return -ENOMEM;
 131
 132         pm_runtime_get_sync(&tb->dev);
 133
 134         if (mutex_lock_interruptible(&tb->lock)) {
 135                 ret = -ERESTARTSYS;
 136                 goto out;
 137         }
 138         ret = tb->cm_ops->get_boot_acl(tb, uuids, tb->nboot_acl);
 139         if (ret) {
 140                 mutex_unlock(&tb->lock);
 141                 goto out;
 142         }
 143         mutex_unlock(&tb->lock);
 144
 145         for (ret = 0, i = 0; i < tb->nboot_acl; i++) {
 146                 if (!uuid_is_null(&uuids[i]))
 147                         ret += sysfs_emit_at(buf, ret, "%pUb", &uuids[i]);
 148
 149                 ret += sysfs_emit_at(buf, ret, "%s", i < tb->nboot_acl - 1 ? "," : "\n");
 150         }
 151
 152 out:
 153         pm_runtime_mark_last_busy(&tb->dev);
 154         pm_runtime_put_autosuspend(&tb->dev);
 155         kfree(uuids);
 156
 157         return ret;
 158 }
 159
 160 static ssize_t boot_acl_store(struct device *dev, struct device_attribute *attr,
 161                               const char *buf, size_t count)
 162 {
 163         struct tb *tb = container_of(dev, struct tb, dev);
 164         char *str, *s, *uuid_str;
 165         ssize_t ret = 0;
 166         uuid_t *acl;
 167         int i = 0;
 168
 169         /*
 170          * Make sure the value is not bigger than tb->nboot_acl * UUID
 171          * length + commas and optional "\n". Also the smallest allowable
 172          * string is tb->nboot_acl * ",".
 173          */
 174         if (count > (UUID_STRING_LEN + 1) * tb->nboot_acl + 1)
 175                 return -EINVAL;
 176         if (count < tb->nboot_acl - 1)
 177                 return -EINVAL;
 178
 179         str = kstrdup(buf, GFP_KERNEL);
 180         if (!str)
 181                 return -ENOMEM;
 182
 183         acl = kcalloc(tb->nboot_acl, sizeof(uuid_t), GFP_KERNEL);
 184         if (!acl) {
 185                 ret = -ENOMEM;
 186                 goto err_free_str;
 187         }
 188
 189         uuid_str = strim(str);
 190         while ((s = strsep(&uuid_str, ",")) != NULL && i < tb->nboot_acl) {
 191                 size_t len = strlen(s);
 192
 193                 if (len) {
 194                         if (len != UUID_STRING_LEN) {
 195                                 ret = -EINVAL;
 196                                 goto err_free_acl;
 197                         }
 198                         ret = uuid_parse(s, &acl[i]);
 199                         if (ret)
 200                                 goto err_free_acl;
 201                 }
 202
 203                 i++;
 204         }
 205
 206         if (s || i < tb->nboot_acl) {
 207                 ret = -EINVAL;
 208                 goto err_free_acl;
 209         }
 210
 211         pm_runtime_get_sync(&tb->dev);
 212
 213         if (mutex_lock_interruptible(&tb->lock)) {
 214                 ret = -ERESTARTSYS;
 215                 goto err_rpm_put;
 216         }
 217         ret = tb->cm_ops->set_boot_acl(tb, acl, tb->nboot_acl);
 218         if (!ret) {
 219                 /* Notify userspace about the change */
 220                 kobject_uevent(&tb->dev.kobj, KOBJ_CHANGE);
 221         }
 222         mutex_unlock(&tb->lock);
 223
 224 err_rpm_put:
 225         pm_runtime_mark_last_busy(&tb->dev);
 226         pm_runtime_put_autosuspend(&tb->dev);
 227 err_free_acl:
 228         kfree(acl);
 229 err_free_str:
 230         kfree(str);
 231
 232         return ret ?: count;
 233 }
 234 static DEVICE_ATTR_RW(boot_acl);
 235
 236 static ssize_t deauthorization_show(struct device *dev,
 237                                     struct device_attribute *attr,
 238                                     char *buf)
 239 {
 240         const struct tb *tb = container_of(dev, struct tb, dev);
 241         bool deauthorization = false;
 242
 243         /* Only meaningful if authorization is supported */
 244         if (tb->security_level == TB_SECURITY_USER ||
 245             tb->security_level == TB_SECURITY_SECURE)
 246                 deauthorization = !!tb->cm_ops->disapprove_switch;
 247
 248         return sysfs_emit(buf, "%d\n", deauthorization);
 249 }
 250 static DEVICE_ATTR_RO(deauthorization);
 251
 252 static ssize_t iommu_dma_protection_show(struct device *dev,
 253                                          struct device_attribute *attr,
 254                                          char *buf)
 255 {
 256         struct tb *tb = container_of(dev, struct tb, dev);
 257
 258         return sysfs_emit(buf, "%d\n", tb->nhi->iommu_dma_protection);
 259 }
 260 static DEVICE_ATTR_RO(iommu_dma_protection);
 261
 262 static ssize_t security_show(struct device *dev, struct device_attribute *attr,
 263                              char *buf)
 264 {
 265         struct tb *tb = container_of(dev, struct tb, dev);
 266         const char *name = "unknown";
 267
 268         if (tb->security_level < ARRAY_SIZE(tb_security_names))
 269                 name = tb_security_names[tb->security_level];
 270
 271         return sysfs_emit(buf, "%s\n", name);
 272 }
 273 static DEVICE_ATTR_RO(security);
 274
 275 static struct attribute *domain_attrs[] = {
 276         &dev_attr_boot_acl.attr,
 277         &dev_attr_deauthorization.attr,
 278         &dev_attr_iommu_dma_protection.attr,
 279         &dev_attr_security.attr,
 280         NULL,
 281 };
 282
 283 static umode_t domain_attr_is_visible(struct kobject *kobj,
 284                                       struct attribute *attr, int n)
 285 {
 286         struct device *dev = kobj_to_dev(kobj);
 287         struct tb *tb = container_of(dev, struct tb, dev);
 288
 289         if (attr == &dev_attr_boot_acl.attr) {
 290                 if (tb->nboot_acl &&
 291                     tb->cm_ops->get_boot_acl &&
 292                     tb->cm_ops->set_boot_acl)
 293                         return attr->mode;
 294                 return 0;
 295         }
 296
 297         return attr->mode;
 298 }
 299
 300 static const struct attribute_group domain_attr_group = {
 301         .is_visible = domain_attr_is_visible,
 302         .attrs = domain_attrs,
 303 };
 304
 305 static const struct attribute_group *domain_attr_groups[] = {
 306         &domain_attr_group,
 307         NULL,
 308 };
 309
 310 struct bus_type tb_bus_type = {
 311         .name = "thunderbolt",
 312         .match = tb_service_match,
 313         .probe = tb_service_probe,
 314         .remove = tb_service_remove,
 315         .shutdown = tb_service_shutdown,
 316 };
 317
 318 static void tb_domain_release(struct device *dev)
 319 {
 320         struct tb *tb = container_of(dev, struct tb, dev);
 321
 322         tb_ctl_free(tb->ctl);
 323         destroy_workqueue(tb->wq);
 324         ida_simple_remove(&tb_domain_ida, tb->index);
 325         mutex_destroy(&tb->lock);
 326         kfree(tb);
 327 }
 328
 329 struct device_type tb_domain_type = {
 330         .name = "thunderbolt_domain",
 331         .release = tb_domain_release,
 332 };
 333
 334 static bool tb_domain_event_cb(void *data, enum tb_cfg_pkg_type type,
 335                                const void *buf, size_t size)
 336 {
 337         struct tb *tb = data;
 338
 339         if (!tb->cm_ops->handle_event) {
 340                 tb_warn(tb, "domain does not have event handler\n");
 341                 return true;
 342         }
 343
 344         switch (type) {
 345         case TB_CFG_PKG_XDOMAIN_REQ:
 346         case TB_CFG_PKG_XDOMAIN_RESP:
 347                 if (tb_is_xdomain_enabled())
 348                         return tb_xdomain_handle_request(tb, type, buf, size);
 349                 break;
 350
 351         default:
 352                 tb->cm_ops->handle_event(tb, type, buf, size);
 353         }
 354
 355         return true;
 356 }
 357
 358 /**
 359  * tb_domain_alloc() - Allocate a domain
 360  * @nhi: Pointer to the host controller
 361  * @timeout_msec: Control channel timeout for non-raw messages
 362  * @privsize: Size of the connection manager private data
 363  *
 364  * Allocates and initializes a new Thunderbolt domain. Connection
 365  * managers are expected to call this and then fill in @cm_ops
 366  * accordingly.
 367  *
 368  * Call tb_domain_put() to release the domain before it has been added
 369  * to the system.
 370  *
 371  * Return: allocated domain structure on %NULL in case of error
 372  */
 373 struct tb *tb_domain_alloc(struct tb_nhi *nhi, int timeout_msec, size_t privsize)
 374 {
 375         struct tb *tb;
 376
 377         /*
 378          * Make sure the structure sizes map with that the hardware
 379          * expects because bit-fields are being used.
 380          */
 381         BUILD_BUG_ON(sizeof(struct tb_regs_switch_header) != 5 * 4);
 382         BUILD_BUG_ON(sizeof(struct tb_regs_port_header) != 8 * 4);
 383         BUILD_BUG_ON(sizeof(struct tb_regs_hop) != 2 * 4);
 384
 385         tb = kzalloc(sizeof(*tb) + privsize, GFP_KERNEL);
 386         if (!tb)
 387                 return NULL;
 388
 389         tb->nhi = nhi;
 390         mutex_init(&tb->lock);
 391
 392         tb->index = ida_simple_get(&tb_domain_ida, 0, 0, GFP_KERNEL);
 393         if (tb->index < 0)
 394                 goto err_free;
 395
 396         tb->wq = alloc_ordered_workqueue("thunderbolt%d", 0, tb->index);
 397         if (!tb->wq)
 398                 goto err_remove_ida;
 399
 400         tb->ctl = tb_ctl_alloc(nhi, timeout_msec, tb_domain_event_cb, tb);
 401         if (!tb->ctl)
 402                 goto err_destroy_wq;
 403
 404         tb->dev.parent = &nhi->pdev->dev;
 405         tb->dev.bus = &tb_bus_type;
 406         tb->dev.type = &tb_domain_type;
 407         tb->dev.groups = domain_attr_groups;
 408         dev_set_name(&tb->dev, "domain%d", tb->index);
 409         device_initialize(&tb->dev);
 410
 411         return tb;
 412
 413 err_destroy_wq:
 414         destroy_workqueue(tb->wq);
 415 err_remove_ida:
 416         ida_simple_remove(&tb_domain_ida, tb->index);
 417 err_free:
 418         kfree(tb);
 419
 420         return NULL;
 421 }
 422
 423 /**
 424  * tb_domain_add() - Add domain to the system
 425  * @tb: Domain to add
 426  *
 427  * Starts the domain and adds it to the system. Hotplugging devices will
 428  * work after this has been returned successfully. In order to remove
 429  * and release the domain after this function has been called, call
 430  * tb_domain_remove().
 431  *
 432  * Return: %0 in case of success and negative errno in case of error
 433  */
 434 int tb_domain_add(struct tb *tb)
 435 {
 436         int ret;
 437
 438         if (WARN_ON(!tb->cm_ops))
 439                 return -EINVAL;
 440
 441         mutex_lock(&tb->lock);
 442         /*
 443          * tb_schedule_hotplug_handler may be called as soon as the config
 444          * channel is started. Thats why we have to hold the lock here.
 445          */
 446         tb_ctl_start(tb->ctl);
 447
 448         if (tb->cm_ops->driver_ready) {
 449                 ret = tb->cm_ops->driver_ready(tb);
 450                 if (ret)
 451                         goto err_ctl_stop;
 452         }
 453
 454         tb_dbg(tb, "security level set to %s\n",
 455                tb_security_names[tb->security_level]);
 456
 457         ret = device_add(&tb->dev);
 458         if (ret)
 459                 goto err_ctl_stop;
 460
 461         /* Start the domain */
 462         if (tb->cm_ops->start) {
 463                 ret = tb->cm_ops->start(tb);
 464                 if (ret)
 465                         goto err_domain_del;
 466         }
 467
 468         /* This starts event processing */
 469         mutex_unlock(&tb->lock);
 470
 471         device_init_wakeup(&tb->dev, true);
 472
 473         pm_runtime_no_callbacks(&tb->dev);
 474         pm_runtime_set_active(&tb->dev);
 475         pm_runtime_enable(&tb->dev);
 476         pm_runtime_set_autosuspend_delay(&tb->dev, TB_AUTOSUSPEND_DELAY);
 477         pm_runtime_mark_last_busy(&tb->dev);
 478         pm_runtime_use_autosuspend(&tb->dev);
 479
 480         return 0;
 481
 482 err_domain_del:
 483         device_del(&tb->dev);
 484 err_ctl_stop:
 485         tb_ctl_stop(tb->ctl);
 486         mutex_unlock(&tb->lock);
 487
 488         return ret;
 489 }
 490
 491 /**
 492  * tb_domain_remove() - Removes and releases a domain
 493  * @tb: Domain to remove
 494  *
 495  * Stops the domain, removes it from the system and releases all
 496  * resources once the last reference has been released.
 497  */
 498 void tb_domain_remove(struct tb *tb)
 499 {
 500         mutex_lock(&tb->lock);
 501         if (tb->cm_ops->stop)
 502                 tb->cm_ops->stop(tb);
 503         /* Stop the domain control traffic */
 504         tb_ctl_stop(tb->ctl);
 505         mutex_unlock(&tb->lock);
 506
 507         flush_workqueue(tb->wq);
 508         device_unregister(&tb->dev);
 509 }
 510
 511 /**
 512  * tb_domain_suspend_noirq() - Suspend a domain
 513  * @tb: Domain to suspend
 514  *
 515  * Suspends all devices in the domain and stops the control channel.
 516  */
 517 int tb_domain_suspend_noirq(struct tb *tb)
 518 {
 519         int ret = 0;
 520
 521         /*
 522          * The control channel interrupt is left enabled during suspend
 523          * and taking the lock here prevents any events happening before
 524          * we actually have stopped the domain and the control channel.
 525          */
 526         mutex_lock(&tb->lock);
 527         if (tb->cm_ops->suspend_noirq)
 528                 ret = tb->cm_ops->suspend_noirq(tb);
 529         if (!ret)
 530                 tb_ctl_stop(tb->ctl);
 531         mutex_unlock(&tb->lock);
 532
 533         return ret;
 534 }
 535
 536 /**
 537  * tb_domain_resume_noirq() - Resume a domain
 538  * @tb: Domain to resume
 539  *
 540  * Re-starts the control channel, and resumes all devices connected to
 541  * the domain.
 542  */
 543 int tb_domain_resume_noirq(struct tb *tb)
 544 {
 545         int ret = 0;
 546
 547         mutex_lock(&tb->lock);
 548         tb_ctl_start(tb->ctl);
 549         if (tb->cm_ops->resume_noirq)
 550                 ret = tb->cm_ops->resume_noirq(tb);
 551         mutex_unlock(&tb->lock);
 552
 553         return ret;
 554 }
 555
 556 int tb_domain_suspend(struct tb *tb)
 557 {
 558         return tb->cm_ops->suspend ? tb->cm_ops->suspend(tb) : 0;
 559 }
 560
 561 int tb_domain_freeze_noirq(struct tb *tb)
 562 {
 563         int ret = 0;
 564
 565         mutex_lock(&tb->lock);
 566         if (tb->cm_ops->freeze_noirq)
 567                 ret = tb->cm_ops->freeze_noirq(tb);
 568         if (!ret)
 569                 tb_ctl_stop(tb->ctl);
 570         mutex_unlock(&tb->lock);
 571
 572         return ret;
 573 }
 574
 575 int tb_domain_thaw_noirq(struct tb *tb)
 576 {
 577         int ret = 0;
 578
 579         mutex_lock(&tb->lock);
 580         tb_ctl_start(tb->ctl);
 581         if (tb->cm_ops->thaw_noirq)
 582                 ret = tb->cm_ops->thaw_noirq(tb);
 583         mutex_unlock(&tb->lock);
 584
 585         return ret;
 586 }
 587
 588 void tb_domain_complete(struct tb *tb)
 589 {
 590         if (tb->cm_ops->complete)
 591                 tb->cm_ops->complete(tb);
 592 }
 593
 594 int tb_domain_runtime_suspend(struct tb *tb)
 595 {
 596         if (tb->cm_ops->runtime_suspend) {
 597                 int ret = tb->cm_ops->runtime_suspend(tb);
 598                 if (ret)
 599                         return ret;
 600         }
 601         tb_ctl_stop(tb->ctl);
 602         return 0;
 603 }
 604
 605 int tb_domain_runtime_resume(struct tb *tb)
 606 {
 607         tb_ctl_start(tb->ctl);
 608         if (tb->cm_ops->runtime_resume) {
 609                 int ret = tb->cm_ops->runtime_resume(tb);
 610                 if (ret)
 611                         return ret;
 612         }
 613         return 0;
 614 }
 615
 616 /**
 617  * tb_domain_disapprove_switch() - Disapprove switch
 618  * @tb: Domain the switch belongs to
 619  * @sw: Switch to disapprove
 620  *
 621  * This will disconnect PCIe tunnel from parent to this @sw.
 622  *
 623  * Return: %0 on success and negative errno in case of failure.
 624  */
 625 int tb_domain_disapprove_switch(struct tb *tb, struct tb_switch *sw)
 626 {
 627         if (!tb->cm_ops->disapprove_switch)
 628                 return -EPERM;
 629
 630         return tb->cm_ops->disapprove_switch(tb, sw);
 631 }
 632
 633 /**
 634  * tb_domain_approve_switch() - Approve switch
 635  * @tb: Domain the switch belongs to
 636  * @sw: Switch to approve
 637  *
 638  * This will approve switch by connection manager specific means. In
 639  * case of success the connection manager will create PCIe tunnel from
 640  * parent to @sw.
 641  */
 642 int tb_domain_approve_switch(struct tb *tb, struct tb_switch *sw)
 643 {
 644         struct tb_switch *parent_sw;
 645
 646         if (!tb->cm_ops->approve_switch)
 647                 return -EPERM;
 648
 649         /* The parent switch must be authorized before this one */
 650         parent_sw = tb_to_switch(sw->dev.parent);
 651         if (!parent_sw || !parent_sw->authorized)
 652                 return -EINVAL;
 653
 654         return tb->cm_ops->approve_switch(tb, sw);
 655 }
 656
 657 /**
 658  * tb_domain_approve_switch_key() - Approve switch and add key
 659  * @tb: Domain the switch belongs to
 660  * @sw: Switch to approve
 661  *
 662  * For switches that support secure connect, this function first adds
 663  * key to the switch NVM using connection manager specific means. If
 664  * adding the key is successful, the switch is approved and connected.
 665  *
 666  * Return: %0 on success and negative errno in case of failure.
 667  */
 668 int tb_domain_approve_switch_key(struct tb *tb, struct tb_switch *sw)
 669 {
 670         struct tb_switch *parent_sw;
 671         int ret;
 672
 673         if (!tb->cm_ops->approve_switch || !tb->cm_ops->add_switch_key)
 674                 return -EPERM;
 675
 676         /* The parent switch must be authorized before this one */
 677         parent_sw = tb_to_switch(sw->dev.parent);
 678         if (!parent_sw || !parent_sw->authorized)
 679                 return -EINVAL;
 680
 681         ret = tb->cm_ops->add_switch_key(tb, sw);
 682         if (ret)
 683                 return ret;
 684
 685         return tb->cm_ops->approve_switch(tb, sw);
 686 }
 687
 688 /**
 689  * tb_domain_challenge_switch_key() - Challenge and approve switch
 690  * @tb: Domain the switch belongs to
 691  * @sw: Switch to approve
 692  *
 693  * For switches that support secure connect, this function generates
 694  * random challenge and sends it to the switch. The switch responds to
 695  * this and if the response matches our random challenge, the switch is
 696  * approved and connected.
 697  *
 698  * Return: %0 on success and negative errno in case of failure.
 699  */
 700 int tb_domain_challenge_switch_key(struct tb *tb, struct tb_switch *sw)
 701 {
 702         u8 challenge[TB_SWITCH_KEY_SIZE];
 703         u8 response[TB_SWITCH_KEY_SIZE];
 704         u8 hmac[TB_SWITCH_KEY_SIZE];
 705         struct tb_switch *parent_sw;
 706         struct crypto_shash *tfm;
 707         struct shash_desc *shash;
 708         int ret;
 709
 710         if (!tb->cm_ops->approve_switch || !tb->cm_ops->challenge_switch_key)
 711                 return -EPERM;
 712
 713         /* The parent switch must be authorized before this one */
 714         parent_sw = tb_to_switch(sw->dev.parent);
 715         if (!parent_sw || !parent_sw->authorized)
 716                 return -EINVAL;
 717
 718         get_random_bytes(challenge, sizeof(challenge));
 719         ret = tb->cm_ops->challenge_switch_key(tb, sw, challenge, response);
 720         if (ret)
 721                 return ret;
 722
 723         tfm = crypto_alloc_shash("hmac(sha256)", 0, 0);
 724         if (IS_ERR(tfm))
 725                 return PTR_ERR(tfm);
 726
 727         ret = crypto_shash_setkey(tfm, sw->key, TB_SWITCH_KEY_SIZE);
 728         if (ret)
 729                 goto err_free_tfm;
 730
 731         shash = kzalloc(sizeof(*shash) + crypto_shash_descsize(tfm),
 732                         GFP_KERNEL);
 733         if (!shash) {
 734                 ret = -ENOMEM;
 735                 goto err_free_tfm;
 736         }
 737
 738         shash->tfm = tfm;
 739
 740         memset(hmac, 0, sizeof(hmac));
 741         ret = crypto_shash_digest(shash, challenge, sizeof(hmac), hmac);
 742         if (ret)
 743                 goto err_free_shash;
 744
 745         /* The returned HMAC must match the one we calculated */
 746         if (memcmp(response, hmac, sizeof(hmac))) {
 747                 ret = -EKEYREJECTED;
 748                 goto err_free_shash;
 749         }
 750
 751         crypto_free_shash(tfm);
 752         kfree(shash);
 753
 754         return tb->cm_ops->approve_switch(tb, sw);
 755
 756 err_free_shash:
 757         kfree(shash);
 758 err_free_tfm:
 759         crypto_free_shash(tfm);
 760
 761         return ret;
 762 }
 763
 764 /**
 765  * tb_domain_disconnect_pcie_paths() - Disconnect all PCIe paths
 766  * @tb: Domain whose PCIe paths to disconnect
 767  *
 768  * This needs to be called in preparation for NVM upgrade of the host
 769  * controller. Makes sure all PCIe paths are disconnected.
 770  *
 771  * Return %0 on success and negative errno in case of error.
 772  */
 773 int tb_domain_disconnect_pcie_paths(struct tb *tb)
 774 {
 775         if (!tb->cm_ops->disconnect_pcie_paths)
 776                 return -EPERM;
 777
 778         return tb->cm_ops->disconnect_pcie_paths(tb);
 779 }
 780
 781 /**
 782  * tb_domain_approve_xdomain_paths() - Enable DMA paths for XDomain
 783  * @tb: Domain enabling the DMA paths
 784  * @xd: XDomain DMA paths are created to
 785  * @transmit_path: HopID we are using to send out packets
 786  * @transmit_ring: DMA ring used to send out packets
 787  * @receive_path: HopID the other end is using to send packets to us
 788  * @receive_ring: DMA ring used to receive packets from @receive_path
 789  *
 790  * Calls connection manager specific method to enable DMA paths to the
 791  * XDomain in question.
 792  *
 793  * Return: 0% in case of success and negative errno otherwise. In
 794  * particular returns %-ENOTSUPP if the connection manager
 795  * implementation does not support XDomains.
 796  */
 797 int tb_domain_approve_xdomain_paths(struct tb *tb, struct tb_xdomain *xd,
 798                                     int transmit_path, int transmit_ring,
 799                                     int receive_path, int receive_ring)
 800 {
 801         if (!tb->cm_ops->approve_xdomain_paths)
 802                 return -ENOTSUPP;
 803
 804         return tb->cm_ops->approve_xdomain_paths(tb, xd, transmit_path,
 805                         transmit_ring, receive_path, receive_ring);
 806 }
 807
 808 /**
 809  * tb_domain_disconnect_xdomain_paths() - Disable DMA paths for XDomain
 810  * @tb: Domain disabling the DMA paths
 811  * @xd: XDomain whose DMA paths are disconnected
 812  * @transmit_path: HopID we are using to send out packets
 813  * @transmit_ring: DMA ring used to send out packets
 814  * @receive_path: HopID the other end is using to send packets to us
 815  * @receive_ring: DMA ring used to receive packets from @receive_path
 816  *
 817  * Calls connection manager specific method to disconnect DMA paths to
 818  * the XDomain in question.
 819  *
 820  * Return: 0% in case of success and negative errno otherwise. In
 821  * particular returns %-ENOTSUPP if the connection manager
 822  * implementation does not support XDomains.
 823  */
 824 int tb_domain_disconnect_xdomain_paths(struct tb *tb, struct tb_xdomain *xd,
 825                                        int transmit_path, int transmit_ring,
 826                                        int receive_path, int receive_ring)
 827 {
 828         if (!tb->cm_ops->disconnect_xdomain_paths)
 829                 return -ENOTSUPP;
 830
 831         return tb->cm_ops->disconnect_xdomain_paths(tb, xd, transmit_path,
 832                         transmit_ring, receive_path, receive_ring);
 833 }
 834
 835 static int disconnect_xdomain(struct device *dev, void *data)
 836 {
 837         struct tb_xdomain *xd;
 838         struct tb *tb = data;
 839         int ret = 0;
 840
 841         xd = tb_to_xdomain(dev);
 842         if (xd && xd->tb == tb)
 843                 ret = tb_xdomain_disable_all_paths(xd);
 844
 845         return ret;
 846 }
 847
 848 /**
 849  * tb_domain_disconnect_all_paths() - Disconnect all paths for the domain
 850  * @tb: Domain whose paths are disconnected
 851  *
 852  * This function can be used to disconnect all paths (PCIe, XDomain) for
 853  * example in preparation for host NVM firmware upgrade. After this is
 854  * called the paths cannot be established without resetting the switch.
 855  *
 856  * Return: %0 in case of success and negative errno otherwise.
 857  */
 858 int tb_domain_disconnect_all_paths(struct tb *tb)
 859 {
 860         int ret;
 861
 862         ret = tb_domain_disconnect_pcie_paths(tb);
 863         if (ret)
 864                 return ret;
 865
 866         return bus_for_each_dev(&tb_bus_type, NULL, tb, disconnect_xdomain);
 867 }
 868
 869 int tb_domain_init(void)
 870 {
 871         int ret;
 872
 873         tb_debugfs_init();
 874         tb_acpi_init();
 875
 876         ret = tb_xdomain_init();
 877         if (ret)
 878                 goto err_acpi;
 879         ret = bus_register(&tb_bus_type);
 880         if (ret)
 881                 goto err_xdomain;
 882
 883         return 0;
 884
 885 err_xdomain:
 886         tb_xdomain_exit();
 887 err_acpi:
 888         tb_acpi_exit();
 889         tb_debugfs_exit();
 890
 891         return ret;
 892 }
 893
 894 void tb_domain_exit(void)
 895 {
 896         bus_unregister(&tb_bus_type);
 897         ida_destroy(&tb_domain_ida);
 898         tb_nvm_exit();
 899         tb_xdomain_exit();
 900         tb_acpi_exit();
 901         tb_debugfs_exit();
 902 }