1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Thunderbolt driver - control channel and configuration commands 4 * 5 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com> 6 * Copyright (C) 2018, Intel Corporation 7 */ 8 9 #include <linux/crc32.h> 10 #include <linux/delay.h> 11 #include <linux/slab.h> 12 #include <linux/pci.h> 13 #include <linux/dmapool.h> 14 #include <linux/workqueue.h> 15 16 #include "ctl.h" 17 18 #define CREATE_TRACE_POINTS 19 #include "trace.h" 20 21 #define TB_CTL_RX_PKG_COUNT 10 22 #define TB_CTL_RETRIES 4 23 24 /** 25 * struct tb_ctl - Thunderbolt control channel 26 * @nhi: Pointer to the NHI structure 27 * @tx: Transmit ring 28 * @rx: Receive ring 29 * @frame_pool: DMA pool for control messages 30 * @rx_packets: Received control messages 31 * @request_queue_lock: Lock protecting @request_queue 32 * @request_queue: List of outstanding requests 33 * @running: Is the control channel running at the moment 34 * @timeout_msec: Default timeout for non-raw control messages 35 * @callback: Callback called when hotplug message is received 36 * @callback_data: Data passed to @callback 37 * @index: Domain number. This will be output with the trace record. 38 */ 39 struct tb_ctl { 40 struct tb_nhi *nhi; 41 struct tb_ring *tx; 42 struct tb_ring *rx; 43 44 struct dma_pool *frame_pool; 45 struct ctl_pkg *rx_packets[TB_CTL_RX_PKG_COUNT]; 46 struct mutex request_queue_lock; 47 struct list_head request_queue; 48 bool running; 49 50 int timeout_msec; 51 event_cb callback; 52 void *callback_data; 53 54 int index; 55 }; 56 57 58 #define tb_ctl_WARN(ctl, format, arg...) \ 59 dev_WARN(&(ctl)->nhi->pdev->dev, format, ## arg) 60 61 #define tb_ctl_err(ctl, format, arg...) \ 62 dev_err(&(ctl)->nhi->pdev->dev, format, ## arg) 63 64 #define tb_ctl_warn(ctl, format, arg...) \ 65 dev_warn(&(ctl)->nhi->pdev->dev, format, ## arg) 66 67 #define tb_ctl_info(ctl, format, arg...) \ 68 dev_info(&(ctl)->nhi->pdev->dev, format, ## arg) 69 70 #define tb_ctl_dbg(ctl, format, arg...) \ 71 dev_dbg(&(ctl)->nhi->pdev->dev, format, ## arg) 72 73 #define tb_ctl_dbg_once(ctl, format, arg...) \ 74 dev_dbg_once(&(ctl)->nhi->pdev->dev, format, ## arg) 75 76 static DECLARE_WAIT_QUEUE_HEAD(tb_cfg_request_cancel_queue); 77 /* Serializes access to request kref_get/put */ 78 static DEFINE_MUTEX(tb_cfg_request_lock); 79 80 /** 81 * tb_cfg_request_alloc() - Allocates a new config request 82 * 83 * This is refcounted object so when you are done with this, call 84 * tb_cfg_request_put() to it. 85 */ 86 struct tb_cfg_request *tb_cfg_request_alloc(void) 87 { 88 struct tb_cfg_request *req; 89 90 req = kzalloc(sizeof(*req), GFP_KERNEL); 91 if (!req) 92 return NULL; 93 94 kref_init(&req->kref); 95 96 return req; 97 } 98 99 /** 100 * tb_cfg_request_get() - Increase refcount of a request 101 * @req: Request whose refcount is increased 102 */ 103 void tb_cfg_request_get(struct tb_cfg_request *req) 104 { 105 mutex_lock(&tb_cfg_request_lock); 106 kref_get(&req->kref); 107 mutex_unlock(&tb_cfg_request_lock); 108 } 109 110 static void tb_cfg_request_destroy(struct kref *kref) 111 { 112 struct tb_cfg_request *req = container_of(kref, typeof(*req), kref); 113 114 kfree(req); 115 } 116 117 /** 118 * tb_cfg_request_put() - Decrease refcount and possibly release the request 119 * @req: Request whose refcount is decreased 120 * 121 * Call this function when you are done with the request. When refcount 122 * goes to %0 the object is released. 123 */ 124 void tb_cfg_request_put(struct tb_cfg_request *req) 125 { 126 mutex_lock(&tb_cfg_request_lock); 127 kref_put(&req->kref, tb_cfg_request_destroy); 128 mutex_unlock(&tb_cfg_request_lock); 129 } 130 131 static int tb_cfg_request_enqueue(struct tb_ctl *ctl, 132 struct tb_cfg_request *req) 133 { 134 WARN_ON(test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags)); 135 WARN_ON(req->ctl); 136 137 mutex_lock(&ctl->request_queue_lock); 138 if (!ctl->running) { 139 mutex_unlock(&ctl->request_queue_lock); 140 return -ENOTCONN; 141 } 142 req->ctl = ctl; 143 list_add_tail(&req->list, &ctl->request_queue); 144 set_bit(TB_CFG_REQUEST_ACTIVE, &req->flags); 145 mutex_unlock(&ctl->request_queue_lock); 146 return 0; 147 } 148 149 static void tb_cfg_request_dequeue(struct tb_cfg_request *req) 150 { 151 struct tb_ctl *ctl = req->ctl; 152 153 mutex_lock(&ctl->request_queue_lock); 154 if (!test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags)) { 155 mutex_unlock(&ctl->request_queue_lock); 156 return; 157 } 158 159 list_del(&req->list); 160 clear_bit(TB_CFG_REQUEST_ACTIVE, &req->flags); 161 if (test_bit(TB_CFG_REQUEST_CANCELED, &req->flags)) 162 wake_up(&tb_cfg_request_cancel_queue); 163 mutex_unlock(&ctl->request_queue_lock); 164 } 165 166 static bool tb_cfg_request_is_active(struct tb_cfg_request *req) 167 { 168 return test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags); 169 } 170 171 static struct tb_cfg_request * 172 tb_cfg_request_find(struct tb_ctl *ctl, struct ctl_pkg *pkg) 173 { 174 struct tb_cfg_request *req = NULL, *iter; 175 176 mutex_lock(&pkg->ctl->request_queue_lock); 177 list_for_each_entry(iter, &pkg->ctl->request_queue, list) { 178 tb_cfg_request_get(iter); 179 if (iter->match(iter, pkg)) { 180 req = iter; 181 break; 182 } 183 tb_cfg_request_put(iter); 184 } 185 mutex_unlock(&pkg->ctl->request_queue_lock); 186 187 return req; 188 } 189 190 /* utility functions */ 191 192 193 static int check_header(const struct ctl_pkg *pkg, u32 len, 194 enum tb_cfg_pkg_type type, u64 route) 195 { 196 struct tb_cfg_header *header = pkg->buffer; 197 198 /* check frame, TODO: frame flags */ 199 if (WARN(len != pkg->frame.size, 200 "wrong framesize (expected %#x, got %#x)\n", 201 len, pkg->frame.size)) 202 return -EIO; 203 if (WARN(type != pkg->frame.eof, "wrong eof (expected %#x, got %#x)\n", 204 type, pkg->frame.eof)) 205 return -EIO; 206 if (WARN(pkg->frame.sof, "wrong sof (expected 0x0, got %#x)\n", 207 pkg->frame.sof)) 208 return -EIO; 209 210 /* check header */ 211 if (WARN(header->unknown != 1 << 9, 212 "header->unknown is %#x\n", header->unknown)) 213 return -EIO; 214 if (WARN(route != tb_cfg_get_route(header), 215 "wrong route (expected %llx, got %llx)", 216 route, tb_cfg_get_route(header))) 217 return -EIO; 218 return 0; 219 } 220 221 static int check_config_address(struct tb_cfg_address addr, 222 enum tb_cfg_space space, u32 offset, 223 u32 length) 224 { 225 if (WARN(addr.zero, "addr.zero is %#x\n", addr.zero)) 226 return -EIO; 227 if (WARN(space != addr.space, "wrong space (expected %x, got %x\n)", 228 space, addr.space)) 229 return -EIO; 230 if (WARN(offset != addr.offset, "wrong offset (expected %x, got %x\n)", 231 offset, addr.offset)) 232 return -EIO; 233 if (WARN(length != addr.length, "wrong space (expected %x, got %x\n)", 234 length, addr.length)) 235 return -EIO; 236 /* 237 * We cannot check addr->port as it is set to the upstream port of the 238 * sender. 239 */ 240 return 0; 241 } 242 243 static struct tb_cfg_result decode_error(const struct ctl_pkg *response) 244 { 245 struct cfg_error_pkg *pkg = response->buffer; 246 struct tb_cfg_result res = { 0 }; 247 res.response_route = tb_cfg_get_route(&pkg->header); 248 res.response_port = 0; 249 res.err = check_header(response, sizeof(*pkg), TB_CFG_PKG_ERROR, 250 tb_cfg_get_route(&pkg->header)); 251 if (res.err) 252 return res; 253 254 res.err = 1; 255 res.tb_error = pkg->error; 256 res.response_port = pkg->port; 257 return res; 258 259 } 260 261 static struct tb_cfg_result parse_header(const struct ctl_pkg *pkg, u32 len, 262 enum tb_cfg_pkg_type type, u64 route) 263 { 264 struct tb_cfg_header *header = pkg->buffer; 265 struct tb_cfg_result res = { 0 }; 266 267 if (pkg->frame.eof == TB_CFG_PKG_ERROR) 268 return decode_error(pkg); 269 270 res.response_port = 0; /* will be updated later for cfg_read/write */ 271 res.response_route = tb_cfg_get_route(header); 272 res.err = check_header(pkg, len, type, route); 273 return res; 274 } 275 276 static void tb_cfg_print_error(struct tb_ctl *ctl, enum tb_cfg_space space, 277 const struct tb_cfg_result *res) 278 { 279 WARN_ON(res->err != 1); 280 switch (res->tb_error) { 281 case TB_CFG_ERROR_PORT_NOT_CONNECTED: 282 /* Port is not connected. This can happen during surprise 283 * removal. Do not warn. */ 284 return; 285 case TB_CFG_ERROR_INVALID_CONFIG_SPACE: 286 /* 287 * Invalid cfg_space/offset/length combination in 288 * cfg_read/cfg_write. 289 */ 290 tb_ctl_dbg_once(ctl, "%llx:%x: invalid config space (%u) or offset\n", 291 res->response_route, res->response_port, space); 292 return; 293 case TB_CFG_ERROR_NO_SUCH_PORT: 294 /* 295 * - The route contains a non-existent port. 296 * - The route contains a non-PHY port (e.g. PCIe). 297 * - The port in cfg_read/cfg_write does not exist. 298 */ 299 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n", 300 res->response_route, res->response_port); 301 return; 302 case TB_CFG_ERROR_LOOP: 303 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n", 304 res->response_route, res->response_port); 305 return; 306 case TB_CFG_ERROR_LOCK: 307 tb_ctl_warn(ctl, "%llx:%x: downstream port is locked\n", 308 res->response_route, res->response_port); 309 return; 310 default: 311 /* 5,6,7,9 and 11 are also valid error codes */ 312 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n", 313 res->response_route, res->response_port); 314 return; 315 } 316 } 317 318 static __be32 tb_crc(const void *data, size_t len) 319 { 320 return cpu_to_be32(~crc32c(~0, data, len)); 321 } 322 323 static void tb_ctl_pkg_free(struct ctl_pkg *pkg) 324 { 325 if (pkg) { 326 dma_pool_free(pkg->ctl->frame_pool, 327 pkg->buffer, pkg->frame.buffer_phy); 328 kfree(pkg); 329 } 330 } 331 332 static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl) 333 { 334 struct ctl_pkg *pkg = kzalloc(sizeof(*pkg), GFP_KERNEL); 335 if (!pkg) 336 return NULL; 337 pkg->ctl = ctl; 338 pkg->buffer = dma_pool_alloc(ctl->frame_pool, GFP_KERNEL, 339 &pkg->frame.buffer_phy); 340 if (!pkg->buffer) { 341 kfree(pkg); 342 return NULL; 343 } 344 return pkg; 345 } 346 347 348 /* RX/TX handling */ 349 350 static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame, 351 bool canceled) 352 { 353 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame); 354 tb_ctl_pkg_free(pkg); 355 } 356 357 /* 358 * tb_cfg_tx() - transmit a packet on the control channel 359 * 360 * len must be a multiple of four. 361 * 362 * Return: Returns 0 on success or an error code on failure. 363 */ 364 static int tb_ctl_tx(struct tb_ctl *ctl, const void *data, size_t len, 365 enum tb_cfg_pkg_type type) 366 { 367 int res; 368 struct ctl_pkg *pkg; 369 if (len % 4 != 0) { /* required for le->be conversion */ 370 tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len); 371 return -EINVAL; 372 } 373 if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */ 374 tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n", 375 len, TB_FRAME_SIZE - 4); 376 return -EINVAL; 377 } 378 pkg = tb_ctl_pkg_alloc(ctl); 379 if (!pkg) 380 return -ENOMEM; 381 pkg->frame.callback = tb_ctl_tx_callback; 382 pkg->frame.size = len + 4; 383 pkg->frame.sof = type; 384 pkg->frame.eof = type; 385 386 trace_tb_tx(ctl->index, type, data, len); 387 388 cpu_to_be32_array(pkg->buffer, data, len / 4); 389 *(__be32 *) (pkg->buffer + len) = tb_crc(pkg->buffer, len); 390 391 res = tb_ring_tx(ctl->tx, &pkg->frame); 392 if (res) /* ring is stopped */ 393 tb_ctl_pkg_free(pkg); 394 return res; 395 } 396 397 /* 398 * tb_ctl_handle_event() - acknowledge a plug event, invoke ctl->callback 399 */ 400 static bool tb_ctl_handle_event(struct tb_ctl *ctl, enum tb_cfg_pkg_type type, 401 struct ctl_pkg *pkg, size_t size) 402 { 403 trace_tb_event(ctl->index, type, pkg->buffer, size); 404 return ctl->callback(ctl->callback_data, type, pkg->buffer, size); 405 } 406 407 static void tb_ctl_rx_submit(struct ctl_pkg *pkg) 408 { 409 tb_ring_rx(pkg->ctl->rx, &pkg->frame); /* 410 * We ignore failures during stop. 411 * All rx packets are referenced 412 * from ctl->rx_packets, so we do 413 * not loose them. 414 */ 415 } 416 417 static int tb_async_error(const struct ctl_pkg *pkg) 418 { 419 const struct cfg_error_pkg *error = pkg->buffer; 420 421 if (pkg->frame.eof != TB_CFG_PKG_ERROR) 422 return false; 423 424 switch (error->error) { 425 case TB_CFG_ERROR_LINK_ERROR: 426 case TB_CFG_ERROR_HEC_ERROR_DETECTED: 427 case TB_CFG_ERROR_FLOW_CONTROL_ERROR: 428 case TB_CFG_ERROR_DP_BW: 429 case TB_CFG_ERROR_ROP_CMPLT: 430 case TB_CFG_ERROR_POP_CMPLT: 431 case TB_CFG_ERROR_PCIE_WAKE: 432 case TB_CFG_ERROR_DP_CON_CHANGE: 433 case TB_CFG_ERROR_DPTX_DISCOVERY: 434 case TB_CFG_ERROR_LINK_RECOVERY: 435 case TB_CFG_ERROR_ASYM_LINK: 436 return true; 437 438 default: 439 return false; 440 } 441 } 442 443 static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame, 444 bool canceled) 445 { 446 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame); 447 struct tb_cfg_request *req; 448 __be32 crc32; 449 450 if (canceled) 451 return; /* 452 * ring is stopped, packet is referenced from 453 * ctl->rx_packets. 454 */ 455 456 if (frame->size < 4 || frame->size % 4 != 0) { 457 tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n", 458 frame->size); 459 goto rx; 460 } 461 462 frame->size -= 4; /* remove checksum */ 463 crc32 = tb_crc(pkg->buffer, frame->size); 464 be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4); 465 466 switch (frame->eof) { 467 case TB_CFG_PKG_READ: 468 case TB_CFG_PKG_WRITE: 469 case TB_CFG_PKG_ERROR: 470 case TB_CFG_PKG_OVERRIDE: 471 case TB_CFG_PKG_RESET: 472 if (*(__be32 *)(pkg->buffer + frame->size) != crc32) { 473 tb_ctl_err(pkg->ctl, 474 "RX: checksum mismatch, dropping packet\n"); 475 goto rx; 476 } 477 if (tb_async_error(pkg)) { 478 tb_ctl_handle_event(pkg->ctl, frame->eof, 479 pkg, frame->size); 480 goto rx; 481 } 482 break; 483 484 case TB_CFG_PKG_EVENT: 485 case TB_CFG_PKG_XDOMAIN_RESP: 486 case TB_CFG_PKG_XDOMAIN_REQ: 487 if (*(__be32 *)(pkg->buffer + frame->size) != crc32) { 488 tb_ctl_err(pkg->ctl, 489 "RX: checksum mismatch, dropping packet\n"); 490 goto rx; 491 } 492 fallthrough; 493 case TB_CFG_PKG_ICM_EVENT: 494 if (tb_ctl_handle_event(pkg->ctl, frame->eof, pkg, frame->size)) 495 goto rx; 496 break; 497 498 default: 499 break; 500 } 501 502 /* 503 * The received packet will be processed only if there is an 504 * active request and that the packet is what is expected. This 505 * prevents packets such as replies coming after timeout has 506 * triggered from messing with the active requests. 507 */ 508 req = tb_cfg_request_find(pkg->ctl, pkg); 509 510 trace_tb_rx(pkg->ctl->index, frame->eof, pkg->buffer, frame->size, !req); 511 512 if (req) { 513 if (req->copy(req, pkg)) 514 schedule_work(&req->work); 515 tb_cfg_request_put(req); 516 } 517 518 rx: 519 tb_ctl_rx_submit(pkg); 520 } 521 522 static void tb_cfg_request_work(struct work_struct *work) 523 { 524 struct tb_cfg_request *req = container_of(work, typeof(*req), work); 525 526 if (!test_bit(TB_CFG_REQUEST_CANCELED, &req->flags)) 527 req->callback(req->callback_data); 528 529 tb_cfg_request_dequeue(req); 530 tb_cfg_request_put(req); 531 } 532 533 /** 534 * tb_cfg_request() - Start control request not waiting for it to complete 535 * @ctl: Control channel to use 536 * @req: Request to start 537 * @callback: Callback called when the request is completed 538 * @callback_data: Data to be passed to @callback 539 * 540 * This queues @req on the given control channel without waiting for it 541 * to complete. When the request completes @callback is called. 542 */ 543 int tb_cfg_request(struct tb_ctl *ctl, struct tb_cfg_request *req, 544 void (*callback)(void *), void *callback_data) 545 { 546 int ret; 547 548 req->flags = 0; 549 req->callback = callback; 550 req->callback_data = callback_data; 551 INIT_WORK(&req->work, tb_cfg_request_work); 552 INIT_LIST_HEAD(&req->list); 553 554 tb_cfg_request_get(req); 555 ret = tb_cfg_request_enqueue(ctl, req); 556 if (ret) 557 goto err_put; 558 559 ret = tb_ctl_tx(ctl, req->request, req->request_size, 560 req->request_type); 561 if (ret) 562 goto err_dequeue; 563 564 if (!req->response) 565 schedule_work(&req->work); 566 567 return 0; 568 569 err_dequeue: 570 tb_cfg_request_dequeue(req); 571 err_put: 572 tb_cfg_request_put(req); 573 574 return ret; 575 } 576 577 /** 578 * tb_cfg_request_cancel() - Cancel a control request 579 * @req: Request to cancel 580 * @err: Error to assign to the request 581 * 582 * This function can be used to cancel ongoing request. It will wait 583 * until the request is not active anymore. 584 */ 585 void tb_cfg_request_cancel(struct tb_cfg_request *req, int err) 586 { 587 set_bit(TB_CFG_REQUEST_CANCELED, &req->flags); 588 schedule_work(&req->work); 589 wait_event(tb_cfg_request_cancel_queue, !tb_cfg_request_is_active(req)); 590 req->result.err = err; 591 } 592 593 static void tb_cfg_request_complete(void *data) 594 { 595 complete(data); 596 } 597 598 /** 599 * tb_cfg_request_sync() - Start control request and wait until it completes 600 * @ctl: Control channel to use 601 * @req: Request to start 602 * @timeout_msec: Timeout how long to wait @req to complete 603 * 604 * Starts a control request and waits until it completes. If timeout 605 * triggers the request is canceled before function returns. Note the 606 * caller needs to make sure only one message for given switch is active 607 * at a time. 608 */ 609 struct tb_cfg_result tb_cfg_request_sync(struct tb_ctl *ctl, 610 struct tb_cfg_request *req, 611 int timeout_msec) 612 { 613 unsigned long timeout = msecs_to_jiffies(timeout_msec); 614 struct tb_cfg_result res = { 0 }; 615 DECLARE_COMPLETION_ONSTACK(done); 616 int ret; 617 618 ret = tb_cfg_request(ctl, req, tb_cfg_request_complete, &done); 619 if (ret) { 620 res.err = ret; 621 return res; 622 } 623 624 if (!wait_for_completion_timeout(&done, timeout)) 625 tb_cfg_request_cancel(req, -ETIMEDOUT); 626 627 flush_work(&req->work); 628 629 return req->result; 630 } 631 632 /* public interface, alloc/start/stop/free */ 633 634 /** 635 * tb_ctl_alloc() - allocate a control channel 636 * @nhi: Pointer to NHI 637 * @index: Domain number 638 * @timeout_msec: Default timeout used with non-raw control messages 639 * @cb: Callback called for plug events 640 * @cb_data: Data passed to @cb 641 * 642 * cb will be invoked once for every hot plug event. 643 * 644 * Return: Returns a pointer on success or NULL on failure. 645 */ 646 struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, int index, int timeout_msec, 647 event_cb cb, void *cb_data) 648 { 649 int i; 650 struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL); 651 if (!ctl) 652 return NULL; 653 654 ctl->nhi = nhi; 655 ctl->index = index; 656 ctl->timeout_msec = timeout_msec; 657 ctl->callback = cb; 658 ctl->callback_data = cb_data; 659 660 mutex_init(&ctl->request_queue_lock); 661 INIT_LIST_HEAD(&ctl->request_queue); 662 ctl->frame_pool = dma_pool_create("thunderbolt_ctl", &nhi->pdev->dev, 663 TB_FRAME_SIZE, 4, 0); 664 if (!ctl->frame_pool) 665 goto err; 666 667 ctl->tx = tb_ring_alloc_tx(nhi, 0, 10, RING_FLAG_NO_SUSPEND); 668 if (!ctl->tx) 669 goto err; 670 671 ctl->rx = tb_ring_alloc_rx(nhi, 0, 10, RING_FLAG_NO_SUSPEND, 0, 0xffff, 672 0xffff, NULL, NULL); 673 if (!ctl->rx) 674 goto err; 675 676 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) { 677 ctl->rx_packets[i] = tb_ctl_pkg_alloc(ctl); 678 if (!ctl->rx_packets[i]) 679 goto err; 680 ctl->rx_packets[i]->frame.callback = tb_ctl_rx_callback; 681 } 682 683 tb_ctl_dbg(ctl, "control channel created\n"); 684 return ctl; 685 err: 686 tb_ctl_free(ctl); 687 return NULL; 688 } 689 690 /** 691 * tb_ctl_free() - free a control channel 692 * @ctl: Control channel to free 693 * 694 * Must be called after tb_ctl_stop. 695 * 696 * Must NOT be called from ctl->callback. 697 */ 698 void tb_ctl_free(struct tb_ctl *ctl) 699 { 700 int i; 701 702 if (!ctl) 703 return; 704 705 if (ctl->rx) 706 tb_ring_free(ctl->rx); 707 if (ctl->tx) 708 tb_ring_free(ctl->tx); 709 710 /* free RX packets */ 711 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) 712 tb_ctl_pkg_free(ctl->rx_packets[i]); 713 714 715 dma_pool_destroy(ctl->frame_pool); 716 kfree(ctl); 717 } 718 719 /** 720 * tb_ctl_start() - start/resume the control channel 721 * @ctl: Control channel to start 722 */ 723 void tb_ctl_start(struct tb_ctl *ctl) 724 { 725 int i; 726 tb_ctl_dbg(ctl, "control channel starting...\n"); 727 tb_ring_start(ctl->tx); /* is used to ack hotplug packets, start first */ 728 tb_ring_start(ctl->rx); 729 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) 730 tb_ctl_rx_submit(ctl->rx_packets[i]); 731 732 ctl->running = true; 733 } 734 735 /** 736 * tb_ctl_stop() - pause the control channel 737 * @ctl: Control channel to stop 738 * 739 * All invocations of ctl->callback will have finished after this method 740 * returns. 741 * 742 * Must NOT be called from ctl->callback. 743 */ 744 void tb_ctl_stop(struct tb_ctl *ctl) 745 { 746 mutex_lock(&ctl->request_queue_lock); 747 ctl->running = false; 748 mutex_unlock(&ctl->request_queue_lock); 749 750 tb_ring_stop(ctl->rx); 751 tb_ring_stop(ctl->tx); 752 753 if (!list_empty(&ctl->request_queue)) 754 tb_ctl_WARN(ctl, "dangling request in request_queue\n"); 755 INIT_LIST_HEAD(&ctl->request_queue); 756 tb_ctl_dbg(ctl, "control channel stopped\n"); 757 } 758 759 /* public interface, commands */ 760 761 /** 762 * tb_cfg_ack_notification() - Ack notification 763 * @ctl: Control channel to use 764 * @route: Router that originated the event 765 * @error: Pointer to the notification package 766 * 767 * Call this as response for non-plug notification to ack it. Returns 768 * %0 on success or an error code on failure. 769 */ 770 int tb_cfg_ack_notification(struct tb_ctl *ctl, u64 route, 771 const struct cfg_error_pkg *error) 772 { 773 struct cfg_ack_pkg pkg = { 774 .header = tb_cfg_make_header(route), 775 }; 776 const char *name; 777 778 switch (error->error) { 779 case TB_CFG_ERROR_LINK_ERROR: 780 name = "link error"; 781 break; 782 case TB_CFG_ERROR_HEC_ERROR_DETECTED: 783 name = "HEC error"; 784 break; 785 case TB_CFG_ERROR_FLOW_CONTROL_ERROR: 786 name = "flow control error"; 787 break; 788 case TB_CFG_ERROR_DP_BW: 789 name = "DP_BW"; 790 break; 791 case TB_CFG_ERROR_ROP_CMPLT: 792 name = "router operation completion"; 793 break; 794 case TB_CFG_ERROR_POP_CMPLT: 795 name = "port operation completion"; 796 break; 797 case TB_CFG_ERROR_PCIE_WAKE: 798 name = "PCIe wake"; 799 break; 800 case TB_CFG_ERROR_DP_CON_CHANGE: 801 name = "DP connector change"; 802 break; 803 case TB_CFG_ERROR_DPTX_DISCOVERY: 804 name = "DPTX discovery"; 805 break; 806 case TB_CFG_ERROR_LINK_RECOVERY: 807 name = "link recovery"; 808 break; 809 case TB_CFG_ERROR_ASYM_LINK: 810 name = "asymmetric link"; 811 break; 812 default: 813 name = "unknown"; 814 break; 815 } 816 817 tb_ctl_dbg(ctl, "acking %s (%#x) notification on %llx\n", name, 818 error->error, route); 819 820 return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_NOTIFY_ACK); 821 } 822 823 /** 824 * tb_cfg_ack_plug() - Ack hot plug/unplug event 825 * @ctl: Control channel to use 826 * @route: Router that originated the event 827 * @port: Port where the hot plug/unplug happened 828 * @unplug: Ack hot plug or unplug 829 * 830 * Call this as response for hot plug/unplug event to ack it. 831 * Returns %0 on success or an error code on failure. 832 */ 833 int tb_cfg_ack_plug(struct tb_ctl *ctl, u64 route, u32 port, bool unplug) 834 { 835 struct cfg_error_pkg pkg = { 836 .header = tb_cfg_make_header(route), 837 .port = port, 838 .error = TB_CFG_ERROR_ACK_PLUG_EVENT, 839 .pg = unplug ? TB_CFG_ERROR_PG_HOT_UNPLUG 840 : TB_CFG_ERROR_PG_HOT_PLUG, 841 }; 842 tb_ctl_dbg(ctl, "acking hot %splug event on %llx:%u\n", 843 unplug ? "un" : "", route, port); 844 return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR); 845 } 846 847 static bool tb_cfg_match(const struct tb_cfg_request *req, 848 const struct ctl_pkg *pkg) 849 { 850 u64 route = tb_cfg_get_route(pkg->buffer) & ~BIT_ULL(63); 851 852 if (pkg->frame.eof == TB_CFG_PKG_ERROR) 853 return true; 854 855 if (pkg->frame.eof != req->response_type) 856 return false; 857 if (route != tb_cfg_get_route(req->request)) 858 return false; 859 if (pkg->frame.size != req->response_size) 860 return false; 861 862 if (pkg->frame.eof == TB_CFG_PKG_READ || 863 pkg->frame.eof == TB_CFG_PKG_WRITE) { 864 const struct cfg_read_pkg *req_hdr = req->request; 865 const struct cfg_read_pkg *res_hdr = pkg->buffer; 866 867 if (req_hdr->addr.seq != res_hdr->addr.seq) 868 return false; 869 } 870 871 return true; 872 } 873 874 static bool tb_cfg_copy(struct tb_cfg_request *req, const struct ctl_pkg *pkg) 875 { 876 struct tb_cfg_result res; 877 878 /* Now make sure it is in expected format */ 879 res = parse_header(pkg, req->response_size, req->response_type, 880 tb_cfg_get_route(req->request)); 881 if (!res.err) 882 memcpy(req->response, pkg->buffer, req->response_size); 883 884 req->result = res; 885 886 /* Always complete when first response is received */ 887 return true; 888 } 889 890 /** 891 * tb_cfg_reset() - send a reset packet and wait for a response 892 * @ctl: Control channel pointer 893 * @route: Router string for the router to send reset 894 * 895 * If the switch at route is incorrectly configured then we will not receive a 896 * reply (even though the switch will reset). The caller should check for 897 * -ETIMEDOUT and attempt to reconfigure the switch. 898 */ 899 struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route) 900 { 901 struct cfg_reset_pkg request = { .header = tb_cfg_make_header(route) }; 902 struct tb_cfg_result res = { 0 }; 903 struct tb_cfg_header reply; 904 struct tb_cfg_request *req; 905 906 req = tb_cfg_request_alloc(); 907 if (!req) { 908 res.err = -ENOMEM; 909 return res; 910 } 911 912 req->match = tb_cfg_match; 913 req->copy = tb_cfg_copy; 914 req->request = &request; 915 req->request_size = sizeof(request); 916 req->request_type = TB_CFG_PKG_RESET; 917 req->response = &reply; 918 req->response_size = sizeof(reply); 919 req->response_type = TB_CFG_PKG_RESET; 920 921 res = tb_cfg_request_sync(ctl, req, ctl->timeout_msec); 922 923 tb_cfg_request_put(req); 924 925 return res; 926 } 927 928 /** 929 * tb_cfg_read_raw() - read from config space into buffer 930 * @ctl: Pointer to the control channel 931 * @buffer: Buffer where the data is read 932 * @route: Route string of the router 933 * @port: Port number when reading from %TB_CFG_PORT, %0 otherwise 934 * @space: Config space selector 935 * @offset: Dword word offset of the register to start reading 936 * @length: Number of dwords to read 937 * @timeout_msec: Timeout in ms how long to wait for the response 938 * 939 * Reads from router config space without translating the possible error. 940 */ 941 struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer, 942 u64 route, u32 port, enum tb_cfg_space space, 943 u32 offset, u32 length, int timeout_msec) 944 { 945 struct tb_cfg_result res = { 0 }; 946 struct cfg_read_pkg request = { 947 .header = tb_cfg_make_header(route), 948 .addr = { 949 .port = port, 950 .space = space, 951 .offset = offset, 952 .length = length, 953 }, 954 }; 955 struct cfg_write_pkg reply; 956 int retries = 0; 957 958 while (retries < TB_CTL_RETRIES) { 959 struct tb_cfg_request *req; 960 961 req = tb_cfg_request_alloc(); 962 if (!req) { 963 res.err = -ENOMEM; 964 return res; 965 } 966 967 request.addr.seq = retries++; 968 969 req->match = tb_cfg_match; 970 req->copy = tb_cfg_copy; 971 req->request = &request; 972 req->request_size = sizeof(request); 973 req->request_type = TB_CFG_PKG_READ; 974 req->response = &reply; 975 req->response_size = 12 + 4 * length; 976 req->response_type = TB_CFG_PKG_READ; 977 978 res = tb_cfg_request_sync(ctl, req, timeout_msec); 979 980 tb_cfg_request_put(req); 981 982 if (res.err != -ETIMEDOUT) 983 break; 984 985 /* Wait a bit (arbitrary time) until we send a retry */ 986 usleep_range(10, 100); 987 } 988 989 if (res.err) 990 return res; 991 992 res.response_port = reply.addr.port; 993 res.err = check_config_address(reply.addr, space, offset, length); 994 if (!res.err) 995 memcpy(buffer, &reply.data, 4 * length); 996 return res; 997 } 998 999 /** 1000 * tb_cfg_write_raw() - write from buffer into config space 1001 * @ctl: Pointer to the control channel 1002 * @buffer: Data to write 1003 * @route: Route string of the router 1004 * @port: Port number when writing to %TB_CFG_PORT, %0 otherwise 1005 * @space: Config space selector 1006 * @offset: Dword word offset of the register to start writing 1007 * @length: Number of dwords to write 1008 * @timeout_msec: Timeout in ms how long to wait for the response 1009 * 1010 * Writes to router config space without translating the possible error. 1011 */ 1012 struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, const void *buffer, 1013 u64 route, u32 port, enum tb_cfg_space space, 1014 u32 offset, u32 length, int timeout_msec) 1015 { 1016 struct tb_cfg_result res = { 0 }; 1017 struct cfg_write_pkg request = { 1018 .header = tb_cfg_make_header(route), 1019 .addr = { 1020 .port = port, 1021 .space = space, 1022 .offset = offset, 1023 .length = length, 1024 }, 1025 }; 1026 struct cfg_read_pkg reply; 1027 int retries = 0; 1028 1029 memcpy(&request.data, buffer, length * 4); 1030 1031 while (retries < TB_CTL_RETRIES) { 1032 struct tb_cfg_request *req; 1033 1034 req = tb_cfg_request_alloc(); 1035 if (!req) { 1036 res.err = -ENOMEM; 1037 return res; 1038 } 1039 1040 request.addr.seq = retries++; 1041 1042 req->match = tb_cfg_match; 1043 req->copy = tb_cfg_copy; 1044 req->request = &request; 1045 req->request_size = 12 + 4 * length; 1046 req->request_type = TB_CFG_PKG_WRITE; 1047 req->response = &reply; 1048 req->response_size = sizeof(reply); 1049 req->response_type = TB_CFG_PKG_WRITE; 1050 1051 res = tb_cfg_request_sync(ctl, req, timeout_msec); 1052 1053 tb_cfg_request_put(req); 1054 1055 if (res.err != -ETIMEDOUT) 1056 break; 1057 1058 /* Wait a bit (arbitrary time) until we send a retry */ 1059 usleep_range(10, 100); 1060 } 1061 1062 if (res.err) 1063 return res; 1064 1065 res.response_port = reply.addr.port; 1066 res.err = check_config_address(reply.addr, space, offset, length); 1067 return res; 1068 } 1069 1070 static int tb_cfg_get_error(struct tb_ctl *ctl, enum tb_cfg_space space, 1071 const struct tb_cfg_result *res) 1072 { 1073 /* 1074 * For unimplemented ports access to port config space may return 1075 * TB_CFG_ERROR_INVALID_CONFIG_SPACE (alternatively their type is 1076 * set to TB_TYPE_INACTIVE). In the former case return -ENODEV so 1077 * that the caller can mark the port as disabled. 1078 */ 1079 if (space == TB_CFG_PORT && 1080 res->tb_error == TB_CFG_ERROR_INVALID_CONFIG_SPACE) 1081 return -ENODEV; 1082 1083 tb_cfg_print_error(ctl, space, res); 1084 1085 if (res->tb_error == TB_CFG_ERROR_LOCK) 1086 return -EACCES; 1087 if (res->tb_error == TB_CFG_ERROR_PORT_NOT_CONNECTED) 1088 return -ENOTCONN; 1089 1090 return -EIO; 1091 } 1092 1093 int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port, 1094 enum tb_cfg_space space, u32 offset, u32 length) 1095 { 1096 struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port, 1097 space, offset, length, ctl->timeout_msec); 1098 switch (res.err) { 1099 case 0: 1100 /* Success */ 1101 break; 1102 1103 case 1: 1104 /* Thunderbolt error, tb_error holds the actual number */ 1105 return tb_cfg_get_error(ctl, space, &res); 1106 1107 case -ETIMEDOUT: 1108 tb_ctl_warn(ctl, "%llx: timeout reading config space %u from %#x\n", 1109 route, space, offset); 1110 break; 1111 1112 default: 1113 WARN(1, "tb_cfg_read: %d\n", res.err); 1114 break; 1115 } 1116 return res.err; 1117 } 1118 1119 int tb_cfg_write(struct tb_ctl *ctl, const void *buffer, u64 route, u32 port, 1120 enum tb_cfg_space space, u32 offset, u32 length) 1121 { 1122 struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port, 1123 space, offset, length, ctl->timeout_msec); 1124 switch (res.err) { 1125 case 0: 1126 /* Success */ 1127 break; 1128 1129 case 1: 1130 /* Thunderbolt error, tb_error holds the actual number */ 1131 return tb_cfg_get_error(ctl, space, &res); 1132 1133 case -ETIMEDOUT: 1134 tb_ctl_warn(ctl, "%llx: timeout writing config space %u to %#x\n", 1135 route, space, offset); 1136 break; 1137 1138 default: 1139 WARN(1, "tb_cfg_write: %d\n", res.err); 1140 break; 1141 } 1142 return res.err; 1143 } 1144 1145 /** 1146 * tb_cfg_get_upstream_port() - get upstream port number of switch at route 1147 * @ctl: Pointer to the control channel 1148 * @route: Route string of the router 1149 * 1150 * Reads the first dword from the switches TB_CFG_SWITCH config area and 1151 * returns the port number from which the reply originated. 1152 * 1153 * Return: Returns the upstream port number on success or an error code on 1154 * failure. 1155 */ 1156 int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route) 1157 { 1158 u32 dummy; 1159 struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0, 1160 TB_CFG_SWITCH, 0, 1, 1161 ctl->timeout_msec); 1162 if (res.err == 1) 1163 return -EIO; 1164 if (res.err) 1165 return res.err; 1166 return res.response_port; 1167 } 1168