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