drivers/thunderbolt/xdomain.c

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