drivers/thunderbolt/xdomain.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Thunderbolt XDomain discovery protocol support
   4  *
   5  * Copyright (C) 2017, Intel Corporation
   6  * Authors: Michael Jamet <michael.jamet@intel.com>
   7  *          Mika Westerberg <mika.westerberg@linux.intel.com>
   8  */
   9
  10 #include <linux/device.h>
  11 #include <linux/kmod.h>
  12 #include <linux/module.h>
  13 #include <linux/pm_runtime.h>
  14 #include <linux/utsname.h>
  15 #include <linux/uuid.h>
  16 #include <linux/workqueue.h>
  17
  18 #include "tb.h"
  19
  20 #define XDOMAIN_DEFAULT_TIMEOUT                 5000 /* ms */
  21 #define XDOMAIN_UUID_RETRIES                    10
  22 #define XDOMAIN_PROPERTIES_RETRIES              60
  23 #define XDOMAIN_PROPERTIES_CHANGED_RETRIES      10
  24
  25 struct xdomain_request_work {
  26         struct work_struct work;
  27         struct tb_xdp_header *pkg;
  28         struct tb *tb;
  29 };
  30
  31 /* Serializes access to the properties and protocol handlers below */
  32 static DEFINE_MUTEX(xdomain_lock);
  33
  34 /* Properties exposed to the remote domains */
  35 static struct tb_property_dir *xdomain_property_dir;
  36 static u32 *xdomain_property_block;
  37 static u32 xdomain_property_block_len;
  38 static u32 xdomain_property_block_gen;
  39
  40 /* Additional protocol handlers */
  41 static LIST_HEAD(protocol_handlers);
  42
  43 /* UUID for XDomain discovery protocol: b638d70e-42ff-40bb-97c2-90e2c0b2ff07 */
  44 static const uuid_t tb_xdp_uuid =
  45         UUID_INIT(0xb638d70e, 0x42ff, 0x40bb,
  46                   0x97, 0xc2, 0x90, 0xe2, 0xc0, 0xb2, 0xff, 0x07);
  47
  48 static bool tb_xdomain_match(const struct tb_cfg_request *req,
  49                              const struct ctl_pkg *pkg)
  50 {
  51         switch (pkg->frame.eof) {
  52         case TB_CFG_PKG_ERROR:
  53                 return true;
  54
  55         case TB_CFG_PKG_XDOMAIN_RESP: {
  56                 const struct tb_xdp_header *res_hdr = pkg->buffer;
  57                 const struct tb_xdp_header *req_hdr = req->request;
  58
  59                 if (pkg->frame.size < req->response_size / 4)
  60                         return false;
  61
  62                 /* Make sure route matches */
  63                 if ((res_hdr->xd_hdr.route_hi & ~BIT(31)) !=
  64                      req_hdr->xd_hdr.route_hi)
  65                         return false;
  66                 if ((res_hdr->xd_hdr.route_lo) != req_hdr->xd_hdr.route_lo)
  67                         return false;
  68
  69                 /* Check that the XDomain protocol matches */
  70                 if (!uuid_equal(&res_hdr->uuid, &req_hdr->uuid))
  71                         return false;
  72
  73                 return true;
  74         }
  75
  76         default:
  77                 return false;
  78         }
  79 }
  80
  81 static bool tb_xdomain_copy(struct tb_cfg_request *req,
  82                             const struct ctl_pkg *pkg)
  83 {
  84         memcpy(req->response, pkg->buffer, req->response_size);
  85         req->result.err = 0;
  86         return true;
  87 }
  88
  89 static void response_ready(void *data)
  90 {
  91         tb_cfg_request_put(data);
  92 }
  93
  94 static int __tb_xdomain_response(struct tb_ctl *ctl, const void *response,
  95                                  size_t size, enum tb_cfg_pkg_type type)
  96 {
  97         struct tb_cfg_request *req;
  98
  99         req = tb_cfg_request_alloc();
 100         if (!req)
 101                 return -ENOMEM;
 102
 103         req->match = tb_xdomain_match;
 104         req->copy = tb_xdomain_copy;
 105         req->request = response;
 106         req->request_size = size;
 107         req->request_type = type;
 108
 109         return tb_cfg_request(ctl, req, response_ready, req);
 110 }
 111
 112 /**
 113  * tb_xdomain_response() - Send a XDomain response message
 114  * @xd: XDomain to send the message
 115  * @response: Response to send
 116  * @size: Size of the response
 117  * @type: PDF type of the response
 118  *
 119  * This can be used to send a XDomain response message to the other
 120  * domain. No response for the message is expected.
 121  *
 122  * Return: %0 in case of success and negative errno in case of failure
 123  */
 124 int tb_xdomain_response(struct tb_xdomain *xd, const void *response,
 125                         size_t size, enum tb_cfg_pkg_type type)
 126 {
 127         return __tb_xdomain_response(xd->tb->ctl, response, size, type);
 128 }
 129 EXPORT_SYMBOL_GPL(tb_xdomain_response);
 130
 131 static int __tb_xdomain_request(struct tb_ctl *ctl, const void *request,
 132         size_t request_size, enum tb_cfg_pkg_type request_type, void *response,
 133         size_t response_size, enum tb_cfg_pkg_type response_type,
 134         unsigned int timeout_msec)
 135 {
 136         struct tb_cfg_request *req;
 137         struct tb_cfg_result res;
 138
 139         req = tb_cfg_request_alloc();
 140         if (!req)
 141                 return -ENOMEM;
 142
 143         req->match = tb_xdomain_match;
 144         req->copy = tb_xdomain_copy;
 145         req->request = request;
 146         req->request_size = request_size;
 147         req->request_type = request_type;
 148         req->response = response;
 149         req->response_size = response_size;
 150         req->response_type = response_type;
 151
 152         res = tb_cfg_request_sync(ctl, req, timeout_msec);
 153
 154         tb_cfg_request_put(req);
 155
 156         return res.err == 1 ? -EIO : res.err;
 157 }
 158
 159 /**
 160  * tb_xdomain_request() - Send a XDomain request
 161  * @xd: XDomain to send the request
 162  * @request: Request to send
 163  * @request_size: Size of the request in bytes
 164  * @request_type: PDF type of the request
 165  * @response: Response is copied here
 166  * @response_size: Expected size of the response in bytes
 167  * @response_type: Expected PDF type of the response
 168  * @timeout_msec: Timeout in milliseconds to wait for the response
 169  *
 170  * This function can be used to send XDomain control channel messages to
 171  * the other domain. The function waits until the response is received
 172  * or when timeout triggers. Whichever comes first.
 173  *
 174  * Return: %0 in case of success and negative errno in case of failure
 175  */
 176 int tb_xdomain_request(struct tb_xdomain *xd, const void *request,
 177         size_t request_size, enum tb_cfg_pkg_type request_type,
 178         void *response, size_t response_size,
 179         enum tb_cfg_pkg_type response_type, unsigned int timeout_msec)
 180 {
 181         return __tb_xdomain_request(xd->tb->ctl, request, request_size,
 182                                     request_type, response, response_size,
 183                                     response_type, timeout_msec);
 184 }
 185 EXPORT_SYMBOL_GPL(tb_xdomain_request);
 186
 187 static inline void tb_xdp_fill_header(struct tb_xdp_header *hdr, u64 route,
 188         u8 sequence, enum tb_xdp_type type, size_t size)
 189 {
 190         u32 length_sn;
 191
 192         length_sn = (size - sizeof(hdr->xd_hdr)) / 4;
 193         length_sn |= (sequence << TB_XDOMAIN_SN_SHIFT) & TB_XDOMAIN_SN_MASK;
 194
 195         hdr->xd_hdr.route_hi = upper_32_bits(route);
 196         hdr->xd_hdr.route_lo = lower_32_bits(route);
 197         hdr->xd_hdr.length_sn = length_sn;
 198         hdr->type = type;
 199         memcpy(&hdr->uuid, &tb_xdp_uuid, sizeof(tb_xdp_uuid));
 200 }
 201
 202 static int tb_xdp_handle_error(const struct tb_xdp_header *hdr)
 203 {
 204         const struct tb_xdp_error_response *error;
 205
 206         if (hdr->type != ERROR_RESPONSE)
 207                 return 0;
 208
 209         error = (const struct tb_xdp_error_response *)hdr;
 210
 211         switch (error->error) {
 212         case ERROR_UNKNOWN_PACKET:
 213         case ERROR_UNKNOWN_DOMAIN:
 214                 return -EIO;
 215         case ERROR_NOT_SUPPORTED:
 216                 return -ENOTSUPP;
 217         case ERROR_NOT_READY:
 218                 return -EAGAIN;
 219         default:
 220                 break;
 221         }
 222
 223         return 0;
 224 }
 225
 226 static int tb_xdp_uuid_request(struct tb_ctl *ctl, u64 route, int retry,
 227                                uuid_t *uuid)
 228 {
 229         struct tb_xdp_uuid_response res;
 230         struct tb_xdp_uuid req;
 231         int ret;
 232
 233         memset(&req, 0, sizeof(req));
 234         tb_xdp_fill_header(&req.hdr, route, retry % 4, UUID_REQUEST,
 235                            sizeof(req));
 236
 237         memset(&res, 0, sizeof(res));
 238         ret = __tb_xdomain_request(ctl, &req, sizeof(req),
 239                                    TB_CFG_PKG_XDOMAIN_REQ, &res, sizeof(res),
 240                                    TB_CFG_PKG_XDOMAIN_RESP,
 241                                    XDOMAIN_DEFAULT_TIMEOUT);
 242         if (ret)
 243                 return ret;
 244
 245         ret = tb_xdp_handle_error(&res.hdr);
 246         if (ret)
 247                 return ret;
 248
 249         uuid_copy(uuid, &res.src_uuid);
 250         return 0;
 251 }
 252
 253 static int tb_xdp_uuid_response(struct tb_ctl *ctl, u64 route, u8 sequence,
 254                                 const uuid_t *uuid)
 255 {
 256         struct tb_xdp_uuid_response res;
 257
 258         memset(&res, 0, sizeof(res));
 259         tb_xdp_fill_header(&res.hdr, route, sequence, UUID_RESPONSE,
 260                            sizeof(res));
 261
 262         uuid_copy(&res.src_uuid, uuid);
 263         res.src_route_hi = upper_32_bits(route);
 264         res.src_route_lo = lower_32_bits(route);
 265
 266         return __tb_xdomain_response(ctl, &res, sizeof(res),
 267                                      TB_CFG_PKG_XDOMAIN_RESP);
 268 }
 269
 270 static int tb_xdp_error_response(struct tb_ctl *ctl, u64 route, u8 sequence,
 271                                  enum tb_xdp_error error)
 272 {
 273         struct tb_xdp_error_response res;
 274
 275         memset(&res, 0, sizeof(res));
 276         tb_xdp_fill_header(&res.hdr, route, sequence, ERROR_RESPONSE,
 277                            sizeof(res));
 278         res.error = error;
 279
 280         return __tb_xdomain_response(ctl, &res, sizeof(res),
 281                                      TB_CFG_PKG_XDOMAIN_RESP);
 282 }
 283
 284 static int tb_xdp_properties_request(struct tb_ctl *ctl, u64 route,
 285         const uuid_t *src_uuid, const uuid_t *dst_uuid, int retry,
 286         u32 **block, u32 *generation)
 287 {
 288         struct tb_xdp_properties_response *res;
 289         struct tb_xdp_properties req;
 290         u16 data_len, len;
 291         size_t total_size;
 292         u32 *data = NULL;
 293         int ret;
 294
 295         total_size = sizeof(*res) + TB_XDP_PROPERTIES_MAX_DATA_LENGTH * 4;
 296         res = kzalloc(total_size, GFP_KERNEL);
 297         if (!res)
 298                 return -ENOMEM;
 299
 300         memset(&req, 0, sizeof(req));
 301         tb_xdp_fill_header(&req.hdr, route, retry % 4, PROPERTIES_REQUEST,
 302                            sizeof(req));
 303         memcpy(&req.src_uuid, src_uuid, sizeof(*src_uuid));
 304         memcpy(&req.dst_uuid, dst_uuid, sizeof(*dst_uuid));
 305
 306         len = 0;
 307         data_len = 0;
 308
 309         do {
 310                 ret = __tb_xdomain_request(ctl, &req, sizeof(req),
 311                                            TB_CFG_PKG_XDOMAIN_REQ, res,
 312                                            total_size, TB_CFG_PKG_XDOMAIN_RESP,
 313                                            XDOMAIN_DEFAULT_TIMEOUT);
 314                 if (ret)
 315                         goto err;
 316
 317                 ret = tb_xdp_handle_error(&res->hdr);
 318                 if (ret)
 319                         goto err;
 320
 321                 /*
 322                  * Package length includes the whole payload without the
 323                  * XDomain header. Validate first that the package is at
 324                  * least size of the response structure.
 325                  */
 326                 len = res->hdr.xd_hdr.length_sn & TB_XDOMAIN_LENGTH_MASK;
 327                 if (len < sizeof(*res) / 4) {
 328                         ret = -EINVAL;
 329                         goto err;
 330                 }
 331
 332                 len += sizeof(res->hdr.xd_hdr) / 4;
 333                 len -= sizeof(*res) / 4;
 334
 335                 if (res->offset != req.offset) {
 336                         ret = -EINVAL;
 337                         goto err;
 338                 }
 339
 340                 /*
 341                  * First time allocate block that has enough space for
 342                  * the whole properties block.
 343                  */
 344                 if (!data) {
 345                         data_len = res->data_length;
 346                         if (data_len > TB_XDP_PROPERTIES_MAX_LENGTH) {
 347                                 ret = -E2BIG;
 348                                 goto err;
 349                         }
 350
 351                         data = kcalloc(data_len, sizeof(u32), GFP_KERNEL);
 352                         if (!data) {
 353                                 ret = -ENOMEM;
 354                                 goto err;
 355                         }
 356                 }
 357
 358                 memcpy(data + req.offset, res->data, len * 4);
 359                 req.offset += len;
 360         } while (!data_len || req.offset < data_len);
 361
 362         *block = data;
 363         *generation = res->generation;
 364
 365         kfree(res);
 366
 367         return data_len;
 368
 369 err:
 370         kfree(data);
 371         kfree(res);
 372
 373         return ret;
 374 }
 375
 376 static int tb_xdp_properties_response(struct tb *tb, struct tb_ctl *ctl,
 377         u64 route, u8 sequence, const uuid_t *src_uuid,
 378         const struct tb_xdp_properties *req)
 379 {
 380         struct tb_xdp_properties_response *res;
 381         size_t total_size;
 382         u16 len;
 383         int ret;
 384
 385         /*
 386          * Currently we expect all requests to be directed to us. The
 387          * protocol supports forwarding, though which we might add
 388          * support later on.
 389          */
 390         if (!uuid_equal(src_uuid, &req->dst_uuid)) {
 391                 tb_xdp_error_response(ctl, route, sequence,
 392                                       ERROR_UNKNOWN_DOMAIN);
 393                 return 0;
 394         }
 395
 396         mutex_lock(&xdomain_lock);
 397
 398         if (req->offset >= xdomain_property_block_len) {
 399                 mutex_unlock(&xdomain_lock);
 400                 return -EINVAL;
 401         }
 402
 403         len = xdomain_property_block_len - req->offset;
 404         len = min_t(u16, len, TB_XDP_PROPERTIES_MAX_DATA_LENGTH);
 405         total_size = sizeof(*res) + len * 4;
 406
 407         res = kzalloc(total_size, GFP_KERNEL);
 408         if (!res) {
 409                 mutex_unlock(&xdomain_lock);
 410                 return -ENOMEM;
 411         }
 412
 413         tb_xdp_fill_header(&res->hdr, route, sequence, PROPERTIES_RESPONSE,
 414                            total_size);
 415         res->generation = xdomain_property_block_gen;
 416         res->data_length = xdomain_property_block_len;
 417         res->offset = req->offset;
 418         uuid_copy(&res->src_uuid, src_uuid);
 419         uuid_copy(&res->dst_uuid, &req->src_uuid);
 420         memcpy(res->data, &xdomain_property_block[req->offset], len * 4);
 421
 422         mutex_unlock(&xdomain_lock);
 423
 424         ret = __tb_xdomain_response(ctl, res, total_size,
 425                                     TB_CFG_PKG_XDOMAIN_RESP);
 426
 427         kfree(res);
 428         return ret;
 429 }
 430
 431 static int tb_xdp_properties_changed_request(struct tb_ctl *ctl, u64 route,
 432                                              int retry, const uuid_t *uuid)
 433 {
 434         struct tb_xdp_properties_changed_response res;
 435         struct tb_xdp_properties_changed req;
 436         int ret;
 437
 438         memset(&req, 0, sizeof(req));
 439         tb_xdp_fill_header(&req.hdr, route, retry % 4,
 440                            PROPERTIES_CHANGED_REQUEST, sizeof(req));
 441         uuid_copy(&req.src_uuid, uuid);
 442
 443         memset(&res, 0, sizeof(res));
 444         ret = __tb_xdomain_request(ctl, &req, sizeof(req),
 445                                    TB_CFG_PKG_XDOMAIN_REQ, &res, sizeof(res),
 446                                    TB_CFG_PKG_XDOMAIN_RESP,
 447                                    XDOMAIN_DEFAULT_TIMEOUT);
 448         if (ret)
 449                 return ret;
 450
 451         return tb_xdp_handle_error(&res.hdr);
 452 }
 453
 454 static int
 455 tb_xdp_properties_changed_response(struct tb_ctl *ctl, u64 route, u8 sequence)
 456 {
 457         struct tb_xdp_properties_changed_response res;
 458
 459         memset(&res, 0, sizeof(res));
 460         tb_xdp_fill_header(&res.hdr, route, sequence,
 461                            PROPERTIES_CHANGED_RESPONSE, sizeof(res));
 462         return __tb_xdomain_response(ctl, &res, sizeof(res),
 463                                      TB_CFG_PKG_XDOMAIN_RESP);
 464 }
 465
 466 /**
 467  * tb_register_protocol_handler() - Register protocol handler
 468  * @handler: Handler to register
 469  *
 470  * This allows XDomain service drivers to hook into incoming XDomain
 471  * messages. After this function is called the service driver needs to
 472  * be able to handle calls to callback whenever a package with the
 473  * registered protocol is received.
 474  */
 475 int tb_register_protocol_handler(struct tb_protocol_handler *handler)
 476 {
 477         if (!handler->uuid || !handler->callback)
 478                 return -EINVAL;
 479         if (uuid_equal(handler->uuid, &tb_xdp_uuid))
 480                 return -EINVAL;
 481
 482         mutex_lock(&xdomain_lock);
 483         list_add_tail(&handler->list, &protocol_handlers);
 484         mutex_unlock(&xdomain_lock);
 485
 486         return 0;
 487 }
 488 EXPORT_SYMBOL_GPL(tb_register_protocol_handler);
 489
 490 /**
 491  * tb_unregister_protocol_handler() - Unregister protocol handler
 492  * @handler: Handler to unregister
 493  *
 494  * Removes the previously registered protocol handler.
 495  */
 496 void tb_unregister_protocol_handler(struct tb_protocol_handler *handler)
 497 {
 498         mutex_lock(&xdomain_lock);
 499         list_del_init(&handler->list);
 500         mutex_unlock(&xdomain_lock);
 501 }
 502 EXPORT_SYMBOL_GPL(tb_unregister_protocol_handler);
 503
 504 static void tb_xdp_handle_request(struct work_struct *work)
 505 {
 506         struct xdomain_request_work *xw = container_of(work, typeof(*xw), work);
 507         const struct tb_xdp_header *pkg = xw->pkg;
 508         const struct tb_xdomain_header *xhdr = &pkg->xd_hdr;
 509         struct tb *tb = xw->tb;
 510         struct tb_ctl *ctl = tb->ctl;
 511         const uuid_t *uuid;
 512         int ret = 0;
 513         u32 sequence;
 514         u64 route;
 515
 516         route = ((u64)xhdr->route_hi << 32 | xhdr->route_lo) & ~BIT_ULL(63);
 517         sequence = xhdr->length_sn & TB_XDOMAIN_SN_MASK;
 518         sequence >>= TB_XDOMAIN_SN_SHIFT;
 519
 520         mutex_lock(&tb->lock);
 521         if (tb->root_switch)
 522                 uuid = tb->root_switch->uuid;
 523         else
 524                 uuid = NULL;
 525         mutex_unlock(&tb->lock);
 526
 527         if (!uuid) {
 528                 tb_xdp_error_response(ctl, route, sequence, ERROR_NOT_READY);
 529                 goto out;
 530         }
 531
 532         switch (pkg->type) {
 533         case PROPERTIES_REQUEST:
 534                 ret = tb_xdp_properties_response(tb, ctl, route, sequence, uuid,
 535                         (const struct tb_xdp_properties *)pkg);
 536                 break;
 537
 538         case PROPERTIES_CHANGED_REQUEST: {
 539                 const struct tb_xdp_properties_changed *xchg =
 540                         (const struct tb_xdp_properties_changed *)pkg;
 541                 struct tb_xdomain *xd;
 542
 543                 ret = tb_xdp_properties_changed_response(ctl, route, sequence);
 544
 545                 /*
 546                  * Since the properties have been changed, let's update
 547                  * the xdomain related to this connection as well in
 548                  * case there is a change in services it offers.
 549                  */
 550                 xd = tb_xdomain_find_by_uuid_locked(tb, &xchg->src_uuid);
 551                 if (xd) {
 552                         queue_delayed_work(tb->wq, &xd->get_properties_work,
 553                                            msecs_to_jiffies(50));
 554                         tb_xdomain_put(xd);
 555                 }
 556
 557                 break;
 558         }
 559
 560         case UUID_REQUEST_OLD:
 561         case UUID_REQUEST:
 562                 ret = tb_xdp_uuid_response(ctl, route, sequence, uuid);
 563                 break;
 564
 565         default:
 566                 tb_xdp_error_response(ctl, route, sequence,
 567                                       ERROR_NOT_SUPPORTED);
 568                 break;
 569         }
 570
 571         if (ret) {
 572                 tb_warn(tb, "failed to send XDomain response for %#x\n",
 573                         pkg->type);
 574         }
 575
 576 out:
 577         kfree(xw->pkg);
 578         kfree(xw);
 579
 580         tb_domain_put(tb);
 581 }
 582
 583 static bool
 584 tb_xdp_schedule_request(struct tb *tb, const struct tb_xdp_header *hdr,
 585                         size_t size)
 586 {
 587         struct xdomain_request_work *xw;
 588
 589         xw = kmalloc(sizeof(*xw), GFP_KERNEL);
 590         if (!xw)
 591                 return false;
 592
 593         INIT_WORK(&xw->work, tb_xdp_handle_request);
 594         xw->pkg = kmemdup(hdr, size, GFP_KERNEL);
 595         if (!xw->pkg) {
 596                 kfree(xw);
 597                 return false;
 598         }
 599         xw->tb = tb_domain_get(tb);
 600
 601         schedule_work(&xw->work);
 602         return true;
 603 }
 604
 605 /**
 606  * tb_register_service_driver() - Register XDomain service driver
 607  * @drv: Driver to register
 608  *
 609  * Registers new service driver from @drv to the bus.
 610  */
 611 int tb_register_service_driver(struct tb_service_driver *drv)
 612 {
 613         drv->driver.bus = &tb_bus_type;
 614         return driver_register(&drv->driver);
 615 }
 616 EXPORT_SYMBOL_GPL(tb_register_service_driver);
 617
 618 /**
 619  * tb_unregister_service_driver() - Unregister XDomain service driver
 620  * @xdrv: Driver to unregister
 621  *
 622  * Unregisters XDomain service driver from the bus.
 623  */
 624 void tb_unregister_service_driver(struct tb_service_driver *drv)
 625 {
 626         driver_unregister(&drv->driver);
 627 }
 628 EXPORT_SYMBOL_GPL(tb_unregister_service_driver);
 629
 630 static ssize_t key_show(struct device *dev, struct device_attribute *attr,
 631                         char *buf)
 632 {
 633         struct tb_service *svc = container_of(dev, struct tb_service, dev);
 634
 635         /*
 636          * It should be null terminated but anything else is pretty much
 637          * allowed.
 638          */
 639         return sprintf(buf, "%*pEp\n", (int)strlen(svc->key), svc->key);
 640 }
 641 static DEVICE_ATTR_RO(key);
 642
 643 static int get_modalias(struct tb_service *svc, char *buf, size_t size)
 644 {
 645         return snprintf(buf, size, "tbsvc:k%sp%08Xv%08Xr%08X", svc->key,
 646                         svc->prtcid, svc->prtcvers, svc->prtcrevs);
 647 }
 648
 649 static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
 650                              char *buf)
 651 {
 652         struct tb_service *svc = container_of(dev, struct tb_service, dev);
 653
 654         /* Full buffer size except new line and null termination */
 655         get_modalias(svc, buf, PAGE_SIZE - 2);
 656         return sprintf(buf, "%s\n", buf);
 657 }
 658 static DEVICE_ATTR_RO(modalias);
 659
 660 static ssize_t prtcid_show(struct device *dev, struct device_attribute *attr,
 661                            char *buf)
 662 {
 663         struct tb_service *svc = container_of(dev, struct tb_service, dev);
 664
 665         return sprintf(buf, "%u\n", svc->prtcid);
 666 }
 667 static DEVICE_ATTR_RO(prtcid);
 668
 669 static ssize_t prtcvers_show(struct device *dev, struct device_attribute *attr,
 670                              char *buf)
 671 {
 672         struct tb_service *svc = container_of(dev, struct tb_service, dev);
 673
 674         return sprintf(buf, "%u\n", svc->prtcvers);
 675 }
 676 static DEVICE_ATTR_RO(prtcvers);
 677
 678 static ssize_t prtcrevs_show(struct device *dev, struct device_attribute *attr,
 679                              char *buf)
 680 {
 681         struct tb_service *svc = container_of(dev, struct tb_service, dev);
 682
 683         return sprintf(buf, "%u\n", svc->prtcrevs);
 684 }
 685 static DEVICE_ATTR_RO(prtcrevs);
 686
 687 static ssize_t prtcstns_show(struct device *dev, struct device_attribute *attr,
 688                              char *buf)
 689 {
 690         struct tb_service *svc = container_of(dev, struct tb_service, dev);
 691
 692         return sprintf(buf, "0x%08x\n", svc->prtcstns);
 693 }
 694 static DEVICE_ATTR_RO(prtcstns);
 695
 696 static struct attribute *tb_service_attrs[] = {
 697         &dev_attr_key.attr,
 698         &dev_attr_modalias.attr,
 699         &dev_attr_prtcid.attr,
 700         &dev_attr_prtcvers.attr,
 701         &dev_attr_prtcrevs.attr,
 702         &dev_attr_prtcstns.attr,
 703         NULL,
 704 };
 705
 706 static struct attribute_group tb_service_attr_group = {
 707         .attrs = tb_service_attrs,
 708 };
 709
 710 static const struct attribute_group *tb_service_attr_groups[] = {
 711         &tb_service_attr_group,
 712         NULL,
 713 };
 714
 715 static int tb_service_uevent(struct device *dev, struct kobj_uevent_env *env)
 716 {
 717         struct tb_service *svc = container_of(dev, struct tb_service, dev);
 718         char modalias[64];
 719
 720         get_modalias(svc, modalias, sizeof(modalias));
 721         return add_uevent_var(env, "MODALIAS=%s", modalias);
 722 }
 723
 724 static void tb_service_release(struct device *dev)
 725 {
 726         struct tb_service *svc = container_of(dev, struct tb_service, dev);
 727         struct tb_xdomain *xd = tb_service_parent(svc);
 728
 729         ida_simple_remove(&xd->service_ids, svc->id);
 730         kfree(svc->key);
 731         kfree(svc);
 732 }
 733
 734 struct device_type tb_service_type = {
 735         .name = "thunderbolt_service",
 736         .groups = tb_service_attr_groups,
 737         .uevent = tb_service_uevent,
 738         .release = tb_service_release,
 739 };
 740 EXPORT_SYMBOL_GPL(tb_service_type);
 741
 742 static int remove_missing_service(struct device *dev, void *data)
 743 {
 744         struct tb_xdomain *xd = data;
 745         struct tb_service *svc;
 746
 747         svc = tb_to_service(dev);
 748         if (!svc)
 749                 return 0;
 750
 751         if (!tb_property_find(xd->properties, svc->key,
 752                               TB_PROPERTY_TYPE_DIRECTORY))
 753                 device_unregister(dev);
 754
 755         return 0;
 756 }
 757
 758 static int find_service(struct device *dev, void *data)
 759 {
 760         const struct tb_property *p = data;
 761         struct tb_service *svc;
 762
 763         svc = tb_to_service(dev);
 764         if (!svc)
 765                 return 0;
 766
 767         return !strcmp(svc->key, p->key);
 768 }
 769
 770 static int populate_service(struct tb_service *svc,
 771                             struct tb_property *property)
 772 {
 773         struct tb_property_dir *dir = property->value.dir;
 774         struct tb_property *p;
 775
 776         /* Fill in standard properties */
 777         p = tb_property_find(dir, "prtcid", TB_PROPERTY_TYPE_VALUE);
 778         if (p)
 779                 svc->prtcid = p->value.immediate;
 780         p = tb_property_find(dir, "prtcvers", TB_PROPERTY_TYPE_VALUE);
 781         if (p)
 782                 svc->prtcvers = p->value.immediate;
 783         p = tb_property_find(dir, "prtcrevs", TB_PROPERTY_TYPE_VALUE);
 784         if (p)
 785                 svc->prtcrevs = p->value.immediate;
 786         p = tb_property_find(dir, "prtcstns", TB_PROPERTY_TYPE_VALUE);
 787         if (p)
 788                 svc->prtcstns = p->value.immediate;
 789
 790         svc->key = kstrdup(property->key, GFP_KERNEL);
 791         if (!svc->key)
 792                 return -ENOMEM;
 793
 794         return 0;
 795 }
 796
 797 static void enumerate_services(struct tb_xdomain *xd)
 798 {
 799         struct tb_service *svc;
 800         struct tb_property *p;
 801         struct device *dev;
 802         int id;
 803
 804         /*
 805          * First remove all services that are not available anymore in
 806          * the updated property block.
 807          */
 808         device_for_each_child_reverse(&xd->dev, xd, remove_missing_service);
 809
 810         /* Then re-enumerate properties creating new services as we go */
 811         tb_property_for_each(xd->properties, p) {
 812                 if (p->type != TB_PROPERTY_TYPE_DIRECTORY)
 813                         continue;
 814
 815                 /* If the service exists already we are fine */
 816                 dev = device_find_child(&xd->dev, p, find_service);
 817                 if (dev) {
 818                         put_device(dev);
 819                         continue;
 820                 }
 821
 822                 svc = kzalloc(sizeof(*svc), GFP_KERNEL);
 823                 if (!svc)
 824                         break;
 825
 826                 if (populate_service(svc, p)) {
 827                         kfree(svc);
 828                         break;
 829                 }
 830
 831                 id = ida_simple_get(&xd->service_ids, 0, 0, GFP_KERNEL);
 832                 if (id < 0) {
 833                         kfree(svc);
 834                         break;
 835                 }
 836                 svc->id = id;
 837                 svc->dev.bus = &tb_bus_type;
 838                 svc->dev.type = &tb_service_type;
 839                 svc->dev.parent = &xd->dev;
 840                 dev_set_name(&svc->dev, "%s.%d", dev_name(&xd->dev), svc->id);
 841
 842                 if (device_register(&svc->dev)) {
 843                         put_device(&svc->dev);
 844                         break;
 845                 }
 846         }
 847 }
 848
 849 static int populate_properties(struct tb_xdomain *xd,
 850                                struct tb_property_dir *dir)
 851 {
 852         const struct tb_property *p;
 853
 854         /* Required properties */
 855         p = tb_property_find(dir, "deviceid", TB_PROPERTY_TYPE_VALUE);
 856         if (!p)
 857                 return -EINVAL;
 858         xd->device = p->value.immediate;
 859
 860         p = tb_property_find(dir, "vendorid", TB_PROPERTY_TYPE_VALUE);
 861         if (!p)
 862                 return -EINVAL;
 863         xd->vendor = p->value.immediate;
 864
 865         kfree(xd->device_name);
 866         xd->device_name = NULL;
 867         kfree(xd->vendor_name);
 868         xd->vendor_name = NULL;
 869
 870         /* Optional properties */
 871         p = tb_property_find(dir, "deviceid", TB_PROPERTY_TYPE_TEXT);
 872         if (p)
 873                 xd->device_name = kstrdup(p->value.text, GFP_KERNEL);
 874         p = tb_property_find(dir, "vendorid", TB_PROPERTY_TYPE_TEXT);
 875         if (p)
 876                 xd->vendor_name = kstrdup(p->value.text, GFP_KERNEL);
 877
 878         return 0;
 879 }
 880
 881 /* Called with @xd->lock held */
 882 static void tb_xdomain_restore_paths(struct tb_xdomain *xd)
 883 {
 884         if (!xd->resume)
 885                 return;
 886
 887         xd->resume = false;
 888         if (xd->transmit_path) {
 889                 dev_dbg(&xd->dev, "re-establishing DMA path\n");
 890                 tb_domain_approve_xdomain_paths(xd->tb, xd);
 891         }
 892 }
 893
 894 static void tb_xdomain_get_uuid(struct work_struct *work)
 895 {
 896         struct tb_xdomain *xd = container_of(work, typeof(*xd),
 897                                              get_uuid_work.work);
 898         struct tb *tb = xd->tb;
 899         uuid_t uuid;
 900         int ret;
 901
 902         ret = tb_xdp_uuid_request(tb->ctl, xd->route, xd->uuid_retries, &uuid);
 903         if (ret < 0) {
 904                 if (xd->uuid_retries-- > 0) {
 905                         queue_delayed_work(xd->tb->wq, &xd->get_uuid_work,
 906                                            msecs_to_jiffies(100));
 907                 } else {
 908                         dev_dbg(&xd->dev, "failed to read remote UUID\n");
 909                 }
 910                 return;
 911         }
 912
 913         if (uuid_equal(&uuid, xd->local_uuid)) {
 914                 dev_dbg(&xd->dev, "intra-domain loop detected\n");
 915                 return;
 916         }
 917
 918         /*
 919          * If the UUID is different, there is another domain connected
 920          * so mark this one unplugged and wait for the connection
 921          * manager to replace it.
 922          */
 923         if (xd->remote_uuid && !uuid_equal(&uuid, xd->remote_uuid)) {
 924                 dev_dbg(&xd->dev, "remote UUID is different, unplugging\n");
 925                 xd->is_unplugged = true;
 926                 return;
 927         }
 928
 929         /* First time fill in the missing UUID */
 930         if (!xd->remote_uuid) {
 931                 xd->remote_uuid = kmemdup(&uuid, sizeof(uuid_t), GFP_KERNEL);
 932                 if (!xd->remote_uuid)
 933                         return;
 934         }
 935
 936         /* Now we can start the normal properties exchange */
 937         queue_delayed_work(xd->tb->wq, &xd->properties_changed_work,
 938                            msecs_to_jiffies(100));
 939         queue_delayed_work(xd->tb->wq, &xd->get_properties_work,
 940                            msecs_to_jiffies(1000));
 941 }
 942
 943 static void tb_xdomain_get_properties(struct work_struct *work)
 944 {
 945         struct tb_xdomain *xd = container_of(work, typeof(*xd),
 946                                              get_properties_work.work);
 947         struct tb_property_dir *dir;
 948         struct tb *tb = xd->tb;
 949         bool update = false;
 950         u32 *block = NULL;
 951         u32 gen = 0;
 952         int ret;
 953
 954         ret = tb_xdp_properties_request(tb->ctl, xd->route, xd->local_uuid,
 955                                         xd->remote_uuid, xd->properties_retries,
 956                                         &block, &gen);
 957         if (ret < 0) {
 958                 if (xd->properties_retries-- > 0) {
 959                         queue_delayed_work(xd->tb->wq, &xd->get_properties_work,
 960                                            msecs_to_jiffies(1000));
 961                 } else {
 962                         /* Give up now */
 963                         dev_err(&xd->dev,
 964                                 "failed read XDomain properties from %pUb\n",
 965                                 xd->remote_uuid);
 966                 }
 967                 return;
 968         }
 969
 970         xd->properties_retries = XDOMAIN_PROPERTIES_RETRIES;
 971
 972         mutex_lock(&xd->lock);
 973
 974         /* Only accept newer generation properties */
 975         if (xd->properties && gen <= xd->property_block_gen) {
 976                 /*
 977                  * On resume it is likely that the properties block is
 978                  * not changed (unless the other end added or removed
 979                  * services). However, we need to make sure the existing
 980                  * DMA paths are restored properly.
 981                  */
 982                 tb_xdomain_restore_paths(xd);
 983                 goto err_free_block;
 984         }
 985
 986         dir = tb_property_parse_dir(block, ret);
 987         if (!dir) {
 988                 dev_err(&xd->dev, "failed to parse XDomain properties\n");
 989                 goto err_free_block;
 990         }
 991
 992         ret = populate_properties(xd, dir);
 993         if (ret) {
 994                 dev_err(&xd->dev, "missing XDomain properties in response\n");
 995                 goto err_free_dir;
 996         }
 997
 998         /* Release the existing one */
 999         if (xd->properties) {
1000                 tb_property_free_dir(xd->properties);
1001                 update = true;
1002         }
1003
1004         xd->properties = dir;
1005         xd->property_block_gen = gen;
1006
1007         tb_xdomain_restore_paths(xd);
1008
1009         mutex_unlock(&xd->lock);
1010
1011         kfree(block);
1012
1013         /*
1014          * Now the device should be ready enough so we can add it to the
1015          * bus and let userspace know about it. If the device is already
1016          * registered, we notify the userspace that it has changed.
1017          */
1018         if (!update) {
1019                 if (device_add(&xd->dev)) {
1020                         dev_err(&xd->dev, "failed to add XDomain device\n");
1021                         return;
1022                 }
1023         } else {
1024                 kobject_uevent(&xd->dev.kobj, KOBJ_CHANGE);
1025         }
1026
1027         enumerate_services(xd);
1028         return;
1029
1030 err_free_dir:
1031         tb_property_free_dir(dir);
1032 err_free_block:
1033         kfree(block);
1034         mutex_unlock(&xd->lock);
1035 }
1036
1037 static void tb_xdomain_properties_changed(struct work_struct *work)
1038 {
1039         struct tb_xdomain *xd = container_of(work, typeof(*xd),
1040                                              properties_changed_work.work);
1041         int ret;
1042
1043         ret = tb_xdp_properties_changed_request(xd->tb->ctl, xd->route,
1044                                 xd->properties_changed_retries, xd->local_uuid);
1045         if (ret) {
1046                 if (xd->properties_changed_retries-- > 0)
1047                         queue_delayed_work(xd->tb->wq,
1048                                            &xd->properties_changed_work,
1049                                            msecs_to_jiffies(1000));
1050                 return;
1051         }
1052
1053         xd->properties_changed_retries = XDOMAIN_PROPERTIES_CHANGED_RETRIES;
1054 }
1055
1056 static ssize_t device_show(struct device *dev, struct device_attribute *attr,
1057                            char *buf)
1058 {
1059         struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);
1060
1061         return sprintf(buf, "%#x\n", xd->device);
1062 }
1063 static DEVICE_ATTR_RO(device);
1064
1065 static ssize_t
1066 device_name_show(struct device *dev, struct device_attribute *attr, char *buf)
1067 {
1068         struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);
1069         int ret;
1070
1071         if (mutex_lock_interruptible(&xd->lock))
1072                 return -ERESTARTSYS;
1073         ret = sprintf(buf, "%s\n", xd->device_name ? xd->device_name : "");
1074         mutex_unlock(&xd->lock);
1075
1076         return ret;
1077 }
1078 static DEVICE_ATTR_RO(device_name);
1079
1080 static ssize_t vendor_show(struct device *dev, struct device_attribute *attr,
1081                            char *buf)
1082 {
1083         struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);
1084
1085         return sprintf(buf, "%#x\n", xd->vendor);
1086 }
1087 static DEVICE_ATTR_RO(vendor);
1088
1089 static ssize_t
1090 vendor_name_show(struct device *dev, struct device_attribute *attr, char *buf)
1091 {
1092         struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);
1093         int ret;
1094
1095         if (mutex_lock_interruptible(&xd->lock))
1096                 return -ERESTARTSYS;
1097         ret = sprintf(buf, "%s\n", xd->vendor_name ? xd->vendor_name : "");
1098         mutex_unlock(&xd->lock);
1099
1100         return ret;
1101 }
1102 static DEVICE_ATTR_RO(vendor_name);
1103
1104 static ssize_t unique_id_show(struct device *dev, struct device_attribute *attr,
1105                               char *buf)
1106 {
1107         struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);
1108
1109         return sprintf(buf, "%pUb\n", xd->remote_uuid);
1110 }
1111 static DEVICE_ATTR_RO(unique_id);
1112
1113 static struct attribute *xdomain_attrs[] = {
1114         &dev_attr_device.attr,
1115         &dev_attr_device_name.attr,
1116         &dev_attr_unique_id.attr,
1117         &dev_attr_vendor.attr,
1118         &dev_attr_vendor_name.attr,
1119         NULL,
1120 };
1121
1122 static struct attribute_group xdomain_attr_group = {
1123         .attrs = xdomain_attrs,
1124 };
1125
1126 static const struct attribute_group *xdomain_attr_groups[] = {
1127         &xdomain_attr_group,
1128         NULL,
1129 };
1130
1131 static void tb_xdomain_release(struct device *dev)
1132 {
1133         struct tb_xdomain *xd = container_of(dev, struct tb_xdomain, dev);
1134
1135         put_device(xd->dev.parent);
1136
1137         tb_property_free_dir(xd->properties);
1138         ida_destroy(&xd->service_ids);
1139
1140         kfree(xd->local_uuid);
1141         kfree(xd->remote_uuid);
1142         kfree(xd->device_name);
1143         kfree(xd->vendor_name);
1144         kfree(xd);
1145 }
1146
1147 static void start_handshake(struct tb_xdomain *xd)
1148 {
1149         xd->uuid_retries = XDOMAIN_UUID_RETRIES;
1150         xd->properties_retries = XDOMAIN_PROPERTIES_RETRIES;
1151         xd->properties_changed_retries = XDOMAIN_PROPERTIES_CHANGED_RETRIES;
1152
1153         if (xd->needs_uuid) {
1154                 queue_delayed_work(xd->tb->wq, &xd->get_uuid_work,
1155                                    msecs_to_jiffies(100));
1156         } else {
1157                 /* Start exchanging properties with the other host */
1158                 queue_delayed_work(xd->tb->wq, &xd->properties_changed_work,
1159                                    msecs_to_jiffies(100));
1160                 queue_delayed_work(xd->tb->wq, &xd->get_properties_work,
1161                                    msecs_to_jiffies(1000));
1162         }
1163 }
1164
1165 static void stop_handshake(struct tb_xdomain *xd)
1166 {
1167         xd->uuid_retries = 0;
1168         xd->properties_retries = 0;
1169         xd->properties_changed_retries = 0;
1170
1171         cancel_delayed_work_sync(&xd->get_uuid_work);
1172         cancel_delayed_work_sync(&xd->get_properties_work);
1173         cancel_delayed_work_sync(&xd->properties_changed_work);
1174 }
1175
1176 static int __maybe_unused tb_xdomain_suspend(struct device *dev)
1177 {
1178         stop_handshake(tb_to_xdomain(dev));
1179         return 0;
1180 }
1181
1182 static int __maybe_unused tb_xdomain_resume(struct device *dev)
1183 {
1184         struct tb_xdomain *xd = tb_to_xdomain(dev);
1185
1186         /*
1187          * Ask tb_xdomain_get_properties() restore any existing DMA
1188          * paths after properties are re-read.
1189          */
1190         xd->resume = true;
1191         start_handshake(xd);
1192
1193         return 0;
1194 }
1195
1196 static const struct dev_pm_ops tb_xdomain_pm_ops = {
1197         SET_SYSTEM_SLEEP_PM_OPS(tb_xdomain_suspend, tb_xdomain_resume)
1198 };
1199
1200 struct device_type tb_xdomain_type = {
1201         .name = "thunderbolt_xdomain",
1202         .release = tb_xdomain_release,
1203         .pm = &tb_xdomain_pm_ops,
1204 };
1205 EXPORT_SYMBOL_GPL(tb_xdomain_type);
1206
1207 /**
1208  * tb_xdomain_alloc() - Allocate new XDomain object
1209  * @tb: Domain where the XDomain belongs
1210  * @parent: Parent device (the switch through the connection to the
1211  *          other domain is reached).
1212  * @route: Route string used to reach the other domain
1213  * @local_uuid: Our local domain UUID
1214  * @remote_uuid: UUID of the other domain (optional)
1215  *
1216  * Allocates new XDomain structure and returns pointer to that. The
1217  * object must be released by calling tb_xdomain_put().
1218  */
1219 struct tb_xdomain *tb_xdomain_alloc(struct tb *tb, struct device *parent,
1220                                     u64 route, const uuid_t *local_uuid,
1221                                     const uuid_t *remote_uuid)
1222 {
1223         struct tb_xdomain *xd;
1224
1225         xd = kzalloc(sizeof(*xd), GFP_KERNEL);
1226         if (!xd)
1227                 return NULL;
1228
1229         xd->tb = tb;
1230         xd->route = route;
1231         ida_init(&xd->service_ids);
1232         mutex_init(&xd->lock);
1233         INIT_DELAYED_WORK(&xd->get_uuid_work, tb_xdomain_get_uuid);
1234         INIT_DELAYED_WORK(&xd->get_properties_work, tb_xdomain_get_properties);
1235         INIT_DELAYED_WORK(&xd->properties_changed_work,
1236                           tb_xdomain_properties_changed);
1237
1238         xd->local_uuid = kmemdup(local_uuid, sizeof(uuid_t), GFP_KERNEL);
1239         if (!xd->local_uuid)
1240                 goto err_free;
1241
1242         if (remote_uuid) {
1243                 xd->remote_uuid = kmemdup(remote_uuid, sizeof(uuid_t),
1244                                           GFP_KERNEL);
1245                 if (!xd->remote_uuid)
1246                         goto err_free_local_uuid;
1247         } else {
1248                 xd->needs_uuid = true;
1249         }
1250
1251         device_initialize(&xd->dev);
1252         xd->dev.parent = get_device(parent);
1253         xd->dev.bus = &tb_bus_type;
1254         xd->dev.type = &tb_xdomain_type;
1255         xd->dev.groups = xdomain_attr_groups;
1256         dev_set_name(&xd->dev, "%u-%llx", tb->index, route);
1257
1258         /*
1259          * This keeps the DMA powered on as long as we have active
1260          * connection to another host.
1261          */
1262         pm_runtime_set_active(&xd->dev);
1263         pm_runtime_get_noresume(&xd->dev);
1264         pm_runtime_enable(&xd->dev);
1265
1266         return xd;
1267
1268 err_free_local_uuid:
1269         kfree(xd->local_uuid);
1270 err_free:
1271         kfree(xd);
1272
1273         return NULL;
1274 }
1275
1276 /**
1277  * tb_xdomain_add() - Add XDomain to the bus
1278  * @xd: XDomain to add
1279  *
1280  * This function starts XDomain discovery protocol handshake and
1281  * eventually adds the XDomain to the bus. After calling this function
1282  * the caller needs to call tb_xdomain_remove() in order to remove and
1283  * release the object regardless whether the handshake succeeded or not.
1284  */
1285 void tb_xdomain_add(struct tb_xdomain *xd)
1286 {
1287         /* Start exchanging properties with the other host */
1288         start_handshake(xd);
1289 }
1290
1291 static int unregister_service(struct device *dev, void *data)
1292 {
1293         device_unregister(dev);
1294         return 0;
1295 }
1296
1297 /**
1298  * tb_xdomain_remove() - Remove XDomain from the bus
1299  * @xd: XDomain to remove
1300  *
1301  * This will stop all ongoing configuration work and remove the XDomain
1302  * along with any services from the bus. When the last reference to @xd
1303  * is released the object will be released as well.
1304  */
1305 void tb_xdomain_remove(struct tb_xdomain *xd)
1306 {
1307         stop_handshake(xd);
1308
1309         device_for_each_child_reverse(&xd->dev, xd, unregister_service);
1310
1311         /*
1312          * Undo runtime PM here explicitly because it is possible that
1313          * the XDomain was never added to the bus and thus device_del()
1314          * is not called for it (device_del() would handle this otherwise).
1315          */
1316         pm_runtime_disable(&xd->dev);
1317         pm_runtime_put_noidle(&xd->dev);
1318         pm_runtime_set_suspended(&xd->dev);
1319
1320         if (!device_is_registered(&xd->dev))
1321                 put_device(&xd->dev);
1322         else
1323                 device_unregister(&xd->dev);
1324 }
1325
1326 /**
1327  * tb_xdomain_enable_paths() - Enable DMA paths for XDomain connection
1328  * @xd: XDomain connection
1329  * @transmit_path: HopID of the transmit path the other end is using to
1330  *                 send packets
1331  * @transmit_ring: DMA ring used to receive packets from the other end
1332  * @receive_path: HopID of the receive path the other end is using to
1333  *                receive packets
1334  * @receive_ring: DMA ring used to send packets to the other end
1335  *
1336  * The function enables DMA paths accordingly so that after successful
1337  * return the caller can send and receive packets using high-speed DMA
1338  * path.
1339  *
1340  * Return: %0 in case of success and negative errno in case of error
1341  */
1342 int tb_xdomain_enable_paths(struct tb_xdomain *xd, u16 transmit_path,
1343                             u16 transmit_ring, u16 receive_path,
1344                             u16 receive_ring)
1345 {
1346         int ret;
1347
1348         mutex_lock(&xd->lock);
1349
1350         if (xd->transmit_path) {
1351                 ret = xd->transmit_path == transmit_path ? 0 : -EBUSY;
1352                 goto exit_unlock;
1353         }
1354
1355         xd->transmit_path = transmit_path;
1356         xd->transmit_ring = transmit_ring;
1357         xd->receive_path = receive_path;
1358         xd->receive_ring = receive_ring;
1359
1360         ret = tb_domain_approve_xdomain_paths(xd->tb, xd);
1361
1362 exit_unlock:
1363         mutex_unlock(&xd->lock);
1364
1365         return ret;
1366 }
1367 EXPORT_SYMBOL_GPL(tb_xdomain_enable_paths);
1368
1369 /**
1370  * tb_xdomain_disable_paths() - Disable DMA paths for XDomain connection
1371  * @xd: XDomain connection
1372  *
1373  * This does the opposite of tb_xdomain_enable_paths(). After call to
1374  * this the caller is not expected to use the rings anymore.
1375  *
1376  * Return: %0 in case of success and negative errno in case of error
1377  */
1378 int tb_xdomain_disable_paths(struct tb_xdomain *xd)
1379 {
1380         int ret = 0;
1381
1382         mutex_lock(&xd->lock);
1383         if (xd->transmit_path) {
1384                 xd->transmit_path = 0;
1385                 xd->transmit_ring = 0;
1386                 xd->receive_path = 0;
1387                 xd->receive_ring = 0;
1388
1389                 ret = tb_domain_disconnect_xdomain_paths(xd->tb, xd);
1390         }
1391         mutex_unlock(&xd->lock);
1392
1393         return ret;
1394 }
1395 EXPORT_SYMBOL_GPL(tb_xdomain_disable_paths);
1396
1397 struct tb_xdomain_lookup {
1398         const uuid_t *uuid;
1399         u8 link;
1400         u8 depth;
1401         u64 route;
1402 };
1403
1404 static struct tb_xdomain *switch_find_xdomain(struct tb_switch *sw,
1405         const struct tb_xdomain_lookup *lookup)
1406 {
1407         int i;
1408
1409         for (i = 1; i <= sw->config.max_port_number; i++) {
1410                 struct tb_port *port = &sw->ports[i];
1411                 struct tb_xdomain *xd;
1412
1413                 if (port->xdomain) {
1414                         xd = port->xdomain;
1415
1416                         if (lookup->uuid) {
1417                                 if (xd->remote_uuid &&
1418                                     uuid_equal(xd->remote_uuid, lookup->uuid))
1419                                         return xd;
1420                         } else if (lookup->link &&
1421                                    lookup->link == xd->link &&
1422                                    lookup->depth == xd->depth) {
1423                                 return xd;
1424                         } else if (lookup->route &&
1425                                    lookup->route == xd->route) {
1426                                 return xd;
1427                         }
1428                 } else if (tb_port_has_remote(port)) {
1429                         xd = switch_find_xdomain(port->remote->sw, lookup);
1430                         if (xd)
1431                                 return xd;
1432                 }
1433         }
1434
1435         return NULL;
1436 }
1437
1438 /**
1439  * tb_xdomain_find_by_uuid() - Find an XDomain by UUID
1440  * @tb: Domain where the XDomain belongs to
1441  * @uuid: UUID to look for
1442  *
1443  * Finds XDomain by walking through the Thunderbolt topology below @tb.
1444  * The returned XDomain will have its reference count increased so the
1445  * caller needs to call tb_xdomain_put() when it is done with the
1446  * object.
1447  *
1448  * This will find all XDomains including the ones that are not yet added
1449  * to the bus (handshake is still in progress).
1450  *
1451  * The caller needs to hold @tb->lock.
1452  */
1453 struct tb_xdomain *tb_xdomain_find_by_uuid(struct tb *tb, const uuid_t *uuid)
1454 {
1455         struct tb_xdomain_lookup lookup;
1456         struct tb_xdomain *xd;
1457
1458         memset(&lookup, 0, sizeof(lookup));
1459         lookup.uuid = uuid;
1460
1461         xd = switch_find_xdomain(tb->root_switch, &lookup);
1462         return tb_xdomain_get(xd);
1463 }
1464 EXPORT_SYMBOL_GPL(tb_xdomain_find_by_uuid);
1465
1466 /**
1467  * tb_xdomain_find_by_link_depth() - Find an XDomain by link and depth
1468  * @tb: Domain where the XDomain belongs to
1469  * @link: Root switch link number
1470  * @depth: Depth in the link
1471  *
1472  * Finds XDomain by walking through the Thunderbolt topology below @tb.
1473  * The returned XDomain will have its reference count increased so the
1474  * caller needs to call tb_xdomain_put() when it is done with the
1475  * object.
1476  *
1477  * This will find all XDomains including the ones that are not yet added
1478  * to the bus (handshake is still in progress).
1479  *
1480  * The caller needs to hold @tb->lock.
1481  */
1482 struct tb_xdomain *tb_xdomain_find_by_link_depth(struct tb *tb, u8 link,
1483                                                  u8 depth)
1484 {
1485         struct tb_xdomain_lookup lookup;
1486         struct tb_xdomain *xd;
1487
1488         memset(&lookup, 0, sizeof(lookup));
1489         lookup.link = link;
1490         lookup.depth = depth;
1491
1492         xd = switch_find_xdomain(tb->root_switch, &lookup);
1493         return tb_xdomain_get(xd);
1494 }
1495
1496 /**
1497  * tb_xdomain_find_by_route() - Find an XDomain by route string
1498  * @tb: Domain where the XDomain belongs to
1499  * @route: XDomain route string
1500  *
1501  * Finds XDomain by walking through the Thunderbolt topology below @tb.
1502  * The returned XDomain will have its reference count increased so the
1503  * caller needs to call tb_xdomain_put() when it is done with the
1504  * object.
1505  *
1506  * This will find all XDomains including the ones that are not yet added
1507  * to the bus (handshake is still in progress).
1508  *
1509  * The caller needs to hold @tb->lock.
1510  */
1511 struct tb_xdomain *tb_xdomain_find_by_route(struct tb *tb, u64 route)
1512 {
1513         struct tb_xdomain_lookup lookup;
1514         struct tb_xdomain *xd;
1515
1516         memset(&lookup, 0, sizeof(lookup));
1517         lookup.route = route;
1518
1519         xd = switch_find_xdomain(tb->root_switch, &lookup);
1520         return tb_xdomain_get(xd);
1521 }
1522 EXPORT_SYMBOL_GPL(tb_xdomain_find_by_route);
1523
1524 bool tb_xdomain_handle_request(struct tb *tb, enum tb_cfg_pkg_type type,
1525                                const void *buf, size_t size)
1526 {
1527         const struct tb_protocol_handler *handler, *tmp;
1528         const struct tb_xdp_header *hdr = buf;
1529         unsigned int length;
1530         int ret = 0;
1531
1532         /* We expect the packet is at least size of the header */
1533         length = hdr->xd_hdr.length_sn & TB_XDOMAIN_LENGTH_MASK;
1534         if (length != size / 4 - sizeof(hdr->xd_hdr) / 4)
1535                 return true;
1536         if (length < sizeof(*hdr) / 4 - sizeof(hdr->xd_hdr) / 4)
1537                 return true;
1538
1539         /*
1540          * Handle XDomain discovery protocol packets directly here. For
1541          * other protocols (based on their UUID) we call registered
1542          * handlers in turn.
1543          */
1544         if (uuid_equal(&hdr->uuid, &tb_xdp_uuid)) {
1545                 if (type == TB_CFG_PKG_XDOMAIN_REQ)
1546                         return tb_xdp_schedule_request(tb, hdr, size);
1547                 return false;
1548         }
1549
1550         mutex_lock(&xdomain_lock);
1551         list_for_each_entry_safe(handler, tmp, &protocol_handlers, list) {
1552                 if (!uuid_equal(&hdr->uuid, handler->uuid))
1553                         continue;
1554
1555                 mutex_unlock(&xdomain_lock);
1556                 ret = handler->callback(buf, size, handler->data);
1557                 mutex_lock(&xdomain_lock);
1558
1559                 if (ret)
1560                         break;
1561         }
1562         mutex_unlock(&xdomain_lock);
1563
1564         return ret > 0;
1565 }
1566
1567 static int rebuild_property_block(void)
1568 {
1569         u32 *block, len;
1570         int ret;
1571
1572         ret = tb_property_format_dir(xdomain_property_dir, NULL, 0);
1573         if (ret < 0)
1574                 return ret;
1575
1576         len = ret;
1577
1578         block = kcalloc(len, sizeof(u32), GFP_KERNEL);
1579         if (!block)
1580                 return -ENOMEM;
1581
1582         ret = tb_property_format_dir(xdomain_property_dir, block, len);
1583         if (ret) {
1584                 kfree(block);
1585                 return ret;
1586         }
1587
1588         kfree(xdomain_property_block);
1589         xdomain_property_block = block;
1590         xdomain_property_block_len = len;
1591         xdomain_property_block_gen++;
1592
1593         return 0;
1594 }
1595
1596 static int update_xdomain(struct device *dev, void *data)
1597 {
1598         struct tb_xdomain *xd;
1599
1600         xd = tb_to_xdomain(dev);
1601         if (xd) {
1602                 queue_delayed_work(xd->tb->wq, &xd->properties_changed_work,
1603                                    msecs_to_jiffies(50));
1604         }
1605
1606         return 0;
1607 }
1608
1609 static void update_all_xdomains(void)
1610 {
1611         bus_for_each_dev(&tb_bus_type, NULL, NULL, update_xdomain);
1612 }
1613
1614 static bool remove_directory(const char *key, const struct tb_property_dir *dir)
1615 {
1616         struct tb_property *p;
1617
1618         p = tb_property_find(xdomain_property_dir, key,
1619                              TB_PROPERTY_TYPE_DIRECTORY);
1620         if (p && p->value.dir == dir) {
1621                 tb_property_remove(p);
1622                 return true;
1623         }
1624         return false;
1625 }
1626
1627 /**
1628  * tb_register_property_dir() - Register property directory to the host
1629  * @key: Key (name) of the directory to add
1630  * @dir: Directory to add
1631  *
1632  * Service drivers can use this function to add new property directory
1633  * to the host available properties. The other connected hosts are
1634  * notified so they can re-read properties of this host if they are
1635  * interested.
1636  *
1637  * Return: %0 on success and negative errno on failure
1638  */
1639 int tb_register_property_dir(const char *key, struct tb_property_dir *dir)
1640 {
1641         int ret;
1642
1643         if (WARN_ON(!xdomain_property_dir))
1644                 return -EAGAIN;
1645
1646         if (!key || strlen(key) > 8)
1647                 return -EINVAL;
1648
1649         mutex_lock(&xdomain_lock);
1650         if (tb_property_find(xdomain_property_dir, key,
1651                              TB_PROPERTY_TYPE_DIRECTORY)) {
1652                 ret = -EEXIST;
1653                 goto err_unlock;
1654         }
1655
1656         ret = tb_property_add_dir(xdomain_property_dir, key, dir);
1657         if (ret)
1658                 goto err_unlock;
1659
1660         ret = rebuild_property_block();
1661         if (ret) {
1662                 remove_directory(key, dir);
1663                 goto err_unlock;
1664         }
1665
1666         mutex_unlock(&xdomain_lock);
1667         update_all_xdomains();
1668         return 0;
1669
1670 err_unlock:
1671         mutex_unlock(&xdomain_lock);
1672         return ret;
1673 }
1674 EXPORT_SYMBOL_GPL(tb_register_property_dir);
1675
1676 /**
1677  * tb_unregister_property_dir() - Removes property directory from host
1678  * @key: Key (name) of the directory
1679  * @dir: Directory to remove
1680  *
1681  * This will remove the existing directory from this host and notify the
1682  * connected hosts about the change.
1683  */
1684 void tb_unregister_property_dir(const char *key, struct tb_property_dir *dir)
1685 {
1686         int ret = 0;
1687
1688         mutex_lock(&xdomain_lock);
1689         if (remove_directory(key, dir))
1690                 ret = rebuild_property_block();
1691         mutex_unlock(&xdomain_lock);
1692
1693         if (!ret)
1694                 update_all_xdomains();
1695 }
1696 EXPORT_SYMBOL_GPL(tb_unregister_property_dir);
1697
1698 int tb_xdomain_init(void)
1699 {
1700         int ret;
1701
1702         xdomain_property_dir = tb_property_create_dir(NULL);
1703         if (!xdomain_property_dir)
1704                 return -ENOMEM;
1705
1706         /*
1707          * Initialize standard set of properties without any service
1708          * directories. Those will be added by service drivers
1709          * themselves when they are loaded.
1710          */
1711         tb_property_add_immediate(xdomain_property_dir, "vendorid",
1712                                   PCI_VENDOR_ID_INTEL);
1713         tb_property_add_text(xdomain_property_dir, "vendorid", "Intel Corp.");
1714         tb_property_add_immediate(xdomain_property_dir, "deviceid", 0x1);
1715         tb_property_add_text(xdomain_property_dir, "deviceid",
1716                              utsname()->nodename);
1717         tb_property_add_immediate(xdomain_property_dir, "devicerv", 0x80000100);
1718
1719         ret = rebuild_property_block();
1720         if (ret) {
1721                 tb_property_free_dir(xdomain_property_dir);
1722                 xdomain_property_dir = NULL;
1723         }
1724
1725         return ret;
1726 }
1727
1728 void tb_xdomain_exit(void)
1729 {
1730         kfree(xdomain_property_block);
1731         tb_property_free_dir(xdomain_property_dir);
1732 }