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 static DECLARE_WAIT_QUEUE_HEAD(tb_cfg_request_cancel_queue); 74 /* Serializes access to request kref_get/put */ 75 static DEFINE_MUTEX(tb_cfg_request_lock); 76 77 /** 78 * tb_cfg_request_alloc() - Allocates a new config request 79 * 80 * This is refcounted object so when you are done with this, call 81 * tb_cfg_request_put() to it. 82 */ 83 struct tb_cfg_request *tb_cfg_request_alloc(void) 84 { 85 struct tb_cfg_request *req; 86 87 req = kzalloc(sizeof(*req), GFP_KERNEL); 88 if (!req) 89 return NULL; 90 91 kref_init(&req->kref); 92 93 return req; 94 } 95 96 /** 97 * tb_cfg_request_get() - Increase refcount of a request 98 * @req: Request whose refcount is increased 99 */ 100 void tb_cfg_request_get(struct tb_cfg_request *req) 101 { 102 mutex_lock(&tb_cfg_request_lock); 103 kref_get(&req->kref); 104 mutex_unlock(&tb_cfg_request_lock); 105 } 106 107 static void tb_cfg_request_destroy(struct kref *kref) 108 { 109 struct tb_cfg_request *req = container_of(kref, typeof(*req), kref); 110 111 kfree(req); 112 } 113 114 /** 115 * tb_cfg_request_put() - Decrease refcount and possibly release the request 116 * @req: Request whose refcount is decreased 117 * 118 * Call this function when you are done with the request. When refcount 119 * goes to %0 the object is released. 120 */ 121 void tb_cfg_request_put(struct tb_cfg_request *req) 122 { 123 mutex_lock(&tb_cfg_request_lock); 124 kref_put(&req->kref, tb_cfg_request_destroy); 125 mutex_unlock(&tb_cfg_request_lock); 126 } 127 128 static int tb_cfg_request_enqueue(struct tb_ctl *ctl, 129 struct tb_cfg_request *req) 130 { 131 WARN_ON(test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags)); 132 WARN_ON(req->ctl); 133 134 mutex_lock(&ctl->request_queue_lock); 135 if (!ctl->running) { 136 mutex_unlock(&ctl->request_queue_lock); 137 return -ENOTCONN; 138 } 139 req->ctl = ctl; 140 list_add_tail(&req->list, &ctl->request_queue); 141 set_bit(TB_CFG_REQUEST_ACTIVE, &req->flags); 142 mutex_unlock(&ctl->request_queue_lock); 143 return 0; 144 } 145 146 static void tb_cfg_request_dequeue(struct tb_cfg_request *req) 147 { 148 struct tb_ctl *ctl = req->ctl; 149 150 mutex_lock(&ctl->request_queue_lock); 151 list_del(&req->list); 152 clear_bit(TB_CFG_REQUEST_ACTIVE, &req->flags); 153 if (test_bit(TB_CFG_REQUEST_CANCELED, &req->flags)) 154 wake_up(&tb_cfg_request_cancel_queue); 155 mutex_unlock(&ctl->request_queue_lock); 156 } 157 158 static bool tb_cfg_request_is_active(struct tb_cfg_request *req) 159 { 160 return test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags); 161 } 162 163 static struct tb_cfg_request * 164 tb_cfg_request_find(struct tb_ctl *ctl, struct ctl_pkg *pkg) 165 { 166 struct tb_cfg_request *req = NULL, *iter; 167 168 mutex_lock(&pkg->ctl->request_queue_lock); 169 list_for_each_entry(iter, &pkg->ctl->request_queue, list) { 170 tb_cfg_request_get(iter); 171 if (iter->match(iter, pkg)) { 172 req = iter; 173 break; 174 } 175 tb_cfg_request_put(iter); 176 } 177 mutex_unlock(&pkg->ctl->request_queue_lock); 178 179 return req; 180 } 181 182 /* utility functions */ 183 184 185 static int check_header(const struct ctl_pkg *pkg, u32 len, 186 enum tb_cfg_pkg_type type, u64 route) 187 { 188 struct tb_cfg_header *header = pkg->buffer; 189 190 /* check frame, TODO: frame flags */ 191 if (WARN(len != pkg->frame.size, 192 "wrong framesize (expected %#x, got %#x)\n", 193 len, pkg->frame.size)) 194 return -EIO; 195 if (WARN(type != pkg->frame.eof, "wrong eof (expected %#x, got %#x)\n", 196 type, pkg->frame.eof)) 197 return -EIO; 198 if (WARN(pkg->frame.sof, "wrong sof (expected 0x0, got %#x)\n", 199 pkg->frame.sof)) 200 return -EIO; 201 202 /* check header */ 203 if (WARN(header->unknown != 1 << 9, 204 "header->unknown is %#x\n", header->unknown)) 205 return -EIO; 206 if (WARN(route != tb_cfg_get_route(header), 207 "wrong route (expected %llx, got %llx)", 208 route, tb_cfg_get_route(header))) 209 return -EIO; 210 return 0; 211 } 212 213 static int check_config_address(struct tb_cfg_address addr, 214 enum tb_cfg_space space, u32 offset, 215 u32 length) 216 { 217 if (WARN(addr.zero, "addr.zero is %#x\n", addr.zero)) 218 return -EIO; 219 if (WARN(space != addr.space, "wrong space (expected %x, got %x\n)", 220 space, addr.space)) 221 return -EIO; 222 if (WARN(offset != addr.offset, "wrong offset (expected %x, got %x\n)", 223 offset, addr.offset)) 224 return -EIO; 225 if (WARN(length != addr.length, "wrong space (expected %x, got %x\n)", 226 length, addr.length)) 227 return -EIO; 228 /* 229 * We cannot check addr->port as it is set to the upstream port of the 230 * sender. 231 */ 232 return 0; 233 } 234 235 static struct tb_cfg_result decode_error(const struct ctl_pkg *response) 236 { 237 struct cfg_error_pkg *pkg = response->buffer; 238 struct tb_cfg_result res = { 0 }; 239 res.response_route = tb_cfg_get_route(&pkg->header); 240 res.response_port = 0; 241 res.err = check_header(response, sizeof(*pkg), TB_CFG_PKG_ERROR, 242 tb_cfg_get_route(&pkg->header)); 243 if (res.err) 244 return res; 245 246 res.err = 1; 247 res.tb_error = pkg->error; 248 res.response_port = pkg->port; 249 return res; 250 251 } 252 253 static struct tb_cfg_result parse_header(const struct ctl_pkg *pkg, u32 len, 254 enum tb_cfg_pkg_type type, u64 route) 255 { 256 struct tb_cfg_header *header = pkg->buffer; 257 struct tb_cfg_result res = { 0 }; 258 259 if (pkg->frame.eof == TB_CFG_PKG_ERROR) 260 return decode_error(pkg); 261 262 res.response_port = 0; /* will be updated later for cfg_read/write */ 263 res.response_route = tb_cfg_get_route(header); 264 res.err = check_header(pkg, len, type, route); 265 return res; 266 } 267 268 static void tb_cfg_print_error(struct tb_ctl *ctl, 269 const struct tb_cfg_result *res) 270 { 271 WARN_ON(res->err != 1); 272 switch (res->tb_error) { 273 case TB_CFG_ERROR_PORT_NOT_CONNECTED: 274 /* Port is not connected. This can happen during surprise 275 * removal. Do not warn. */ 276 return; 277 case TB_CFG_ERROR_INVALID_CONFIG_SPACE: 278 /* 279 * Invalid cfg_space/offset/length combination in 280 * cfg_read/cfg_write. 281 */ 282 tb_ctl_dbg(ctl, "%llx:%x: invalid config space or offset\n", 283 res->response_route, res->response_port); 284 return; 285 case TB_CFG_ERROR_NO_SUCH_PORT: 286 /* 287 * - The route contains a non-existent port. 288 * - The route contains a non-PHY port (e.g. PCIe). 289 * - The port in cfg_read/cfg_write does not exist. 290 */ 291 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n", 292 res->response_route, res->response_port); 293 return; 294 case TB_CFG_ERROR_LOOP: 295 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n", 296 res->response_route, res->response_port); 297 return; 298 case TB_CFG_ERROR_LOCK: 299 tb_ctl_warn(ctl, "%llx:%x: downstream port is locked\n", 300 res->response_route, res->response_port); 301 return; 302 default: 303 /* 5,6,7,9 and 11 are also valid error codes */ 304 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n", 305 res->response_route, res->response_port); 306 return; 307 } 308 } 309 310 static __be32 tb_crc(const void *data, size_t len) 311 { 312 return cpu_to_be32(~__crc32c_le(~0, data, len)); 313 } 314 315 static void tb_ctl_pkg_free(struct ctl_pkg *pkg) 316 { 317 if (pkg) { 318 dma_pool_free(pkg->ctl->frame_pool, 319 pkg->buffer, pkg->frame.buffer_phy); 320 kfree(pkg); 321 } 322 } 323 324 static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl) 325 { 326 struct ctl_pkg *pkg = kzalloc(sizeof(*pkg), GFP_KERNEL); 327 if (!pkg) 328 return NULL; 329 pkg->ctl = ctl; 330 pkg->buffer = dma_pool_alloc(ctl->frame_pool, GFP_KERNEL, 331 &pkg->frame.buffer_phy); 332 if (!pkg->buffer) { 333 kfree(pkg); 334 return NULL; 335 } 336 return pkg; 337 } 338 339 340 /* RX/TX handling */ 341 342 static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame, 343 bool canceled) 344 { 345 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame); 346 tb_ctl_pkg_free(pkg); 347 } 348 349 /* 350 * tb_cfg_tx() - transmit a packet on the control channel 351 * 352 * len must be a multiple of four. 353 * 354 * Return: Returns 0 on success or an error code on failure. 355 */ 356 static int tb_ctl_tx(struct tb_ctl *ctl, const void *data, size_t len, 357 enum tb_cfg_pkg_type type) 358 { 359 int res; 360 struct ctl_pkg *pkg; 361 if (len % 4 != 0) { /* required for le->be conversion */ 362 tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len); 363 return -EINVAL; 364 } 365 if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */ 366 tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n", 367 len, TB_FRAME_SIZE - 4); 368 return -EINVAL; 369 } 370 pkg = tb_ctl_pkg_alloc(ctl); 371 if (!pkg) 372 return -ENOMEM; 373 pkg->frame.callback = tb_ctl_tx_callback; 374 pkg->frame.size = len + 4; 375 pkg->frame.sof = type; 376 pkg->frame.eof = type; 377 378 trace_tb_tx(ctl->index, type, data, len); 379 380 cpu_to_be32_array(pkg->buffer, data, len / 4); 381 *(__be32 *) (pkg->buffer + len) = tb_crc(pkg->buffer, len); 382 383 res = tb_ring_tx(ctl->tx, &pkg->frame); 384 if (res) /* ring is stopped */ 385 tb_ctl_pkg_free(pkg); 386 return res; 387 } 388 389 /* 390 * tb_ctl_handle_event() - acknowledge a plug event, invoke ctl->callback 391 */ 392 static bool tb_ctl_handle_event(struct tb_ctl *ctl, enum tb_cfg_pkg_type type, 393 struct ctl_pkg *pkg, size_t size) 394 { 395 trace_tb_event(ctl->index, type, pkg->buffer, size); 396 return ctl->callback(ctl->callback_data, type, pkg->buffer, size); 397 } 398 399 static void tb_ctl_rx_submit(struct ctl_pkg *pkg) 400 { 401 tb_ring_rx(pkg->ctl->rx, &pkg->frame); /* 402 * We ignore failures during stop. 403 * All rx packets are referenced 404 * from ctl->rx_packets, so we do 405 * not loose them. 406 */ 407 } 408 409 static int tb_async_error(const struct ctl_pkg *pkg) 410 { 411 const struct cfg_error_pkg *error = pkg->buffer; 412 413 if (pkg->frame.eof != TB_CFG_PKG_ERROR) 414 return false; 415 416 switch (error->error) { 417 case TB_CFG_ERROR_LINK_ERROR: 418 case TB_CFG_ERROR_HEC_ERROR_DETECTED: 419 case TB_CFG_ERROR_FLOW_CONTROL_ERROR: 420 case TB_CFG_ERROR_DP_BW: 421 case TB_CFG_ERROR_ROP_CMPLT: 422 case TB_CFG_ERROR_POP_CMPLT: 423 case TB_CFG_ERROR_PCIE_WAKE: 424 case TB_CFG_ERROR_DP_CON_CHANGE: 425 case TB_CFG_ERROR_DPTX_DISCOVERY: 426 case TB_CFG_ERROR_LINK_RECOVERY: 427 case TB_CFG_ERROR_ASYM_LINK: 428 return true; 429 430 default: 431 return false; 432 } 433 } 434 435 static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame, 436 bool canceled) 437 { 438 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame); 439 struct tb_cfg_request *req; 440 __be32 crc32; 441 442 if (canceled) 443 return; /* 444 * ring is stopped, packet is referenced from 445 * ctl->rx_packets. 446 */ 447 448 if (frame->size < 4 || frame->size % 4 != 0) { 449 tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n", 450 frame->size); 451 goto rx; 452 } 453 454 frame->size -= 4; /* remove checksum */ 455 crc32 = tb_crc(pkg->buffer, frame->size); 456 be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4); 457 458 switch (frame->eof) { 459 case TB_CFG_PKG_READ: 460 case TB_CFG_PKG_WRITE: 461 case TB_CFG_PKG_ERROR: 462 case TB_CFG_PKG_OVERRIDE: 463 case TB_CFG_PKG_RESET: 464 if (*(__be32 *)(pkg->buffer + frame->size) != crc32) { 465 tb_ctl_err(pkg->ctl, 466 "RX: checksum mismatch, dropping packet\n"); 467 goto rx; 468 } 469 if (tb_async_error(pkg)) { 470 tb_ctl_handle_event(pkg->ctl, frame->eof, 471 pkg, frame->size); 472 goto rx; 473 } 474 break; 475 476 case TB_CFG_PKG_EVENT: 477 case TB_CFG_PKG_XDOMAIN_RESP: 478 case TB_CFG_PKG_XDOMAIN_REQ: 479 if (*(__be32 *)(pkg->buffer + frame->size) != crc32) { 480 tb_ctl_err(pkg->ctl, 481 "RX: checksum mismatch, dropping packet\n"); 482 goto rx; 483 } 484 fallthrough; 485 case TB_CFG_PKG_ICM_EVENT: 486 if (tb_ctl_handle_event(pkg->ctl, frame->eof, pkg, frame->size)) 487 goto rx; 488 break; 489 490 default: 491 break; 492 } 493 494 /* 495 * The received packet will be processed only if there is an 496 * active request and that the packet is what is expected. This 497 * prevents packets such as replies coming after timeout has 498 * triggered from messing with the active requests. 499 */ 500 req = tb_cfg_request_find(pkg->ctl, pkg); 501 502 trace_tb_rx(pkg->ctl->index, frame->eof, pkg->buffer, frame->size, !req); 503 504 if (req) { 505 if (req->copy(req, pkg)) 506 schedule_work(&req->work); 507 tb_cfg_request_put(req); 508 } 509 510 rx: 511 tb_ctl_rx_submit(pkg); 512 } 513 514 static void tb_cfg_request_work(struct work_struct *work) 515 { 516 struct tb_cfg_request *req = container_of(work, typeof(*req), work); 517 518 if (!test_bit(TB_CFG_REQUEST_CANCELED, &req->flags)) 519 req->callback(req->callback_data); 520 521 tb_cfg_request_dequeue(req); 522 tb_cfg_request_put(req); 523 } 524 525 /** 526 * tb_cfg_request() - Start control request not waiting for it to complete 527 * @ctl: Control channel to use 528 * @req: Request to start 529 * @callback: Callback called when the request is completed 530 * @callback_data: Data to be passed to @callback 531 * 532 * This queues @req on the given control channel without waiting for it 533 * to complete. When the request completes @callback is called. 534 */ 535 int tb_cfg_request(struct tb_ctl *ctl, struct tb_cfg_request *req, 536 void (*callback)(void *), void *callback_data) 537 { 538 int ret; 539 540 req->flags = 0; 541 req->callback = callback; 542 req->callback_data = callback_data; 543 INIT_WORK(&req->work, tb_cfg_request_work); 544 INIT_LIST_HEAD(&req->list); 545 546 tb_cfg_request_get(req); 547 ret = tb_cfg_request_enqueue(ctl, req); 548 if (ret) 549 goto err_put; 550 551 ret = tb_ctl_tx(ctl, req->request, req->request_size, 552 req->request_type); 553 if (ret) 554 goto err_dequeue; 555 556 if (!req->response) 557 schedule_work(&req->work); 558 559 return 0; 560 561 err_dequeue: 562 tb_cfg_request_dequeue(req); 563 err_put: 564 tb_cfg_request_put(req); 565 566 return ret; 567 } 568 569 /** 570 * tb_cfg_request_cancel() - Cancel a control request 571 * @req: Request to cancel 572 * @err: Error to assign to the request 573 * 574 * This function can be used to cancel ongoing request. It will wait 575 * until the request is not active anymore. 576 */ 577 void tb_cfg_request_cancel(struct tb_cfg_request *req, int err) 578 { 579 set_bit(TB_CFG_REQUEST_CANCELED, &req->flags); 580 schedule_work(&req->work); 581 wait_event(tb_cfg_request_cancel_queue, !tb_cfg_request_is_active(req)); 582 req->result.err = err; 583 } 584 585 static void tb_cfg_request_complete(void *data) 586 { 587 complete(data); 588 } 589 590 /** 591 * tb_cfg_request_sync() - Start control request and wait until it completes 592 * @ctl: Control channel to use 593 * @req: Request to start 594 * @timeout_msec: Timeout how long to wait @req to complete 595 * 596 * Starts a control request and waits until it completes. If timeout 597 * triggers the request is canceled before function returns. Note the 598 * caller needs to make sure only one message for given switch is active 599 * at a time. 600 */ 601 struct tb_cfg_result tb_cfg_request_sync(struct tb_ctl *ctl, 602 struct tb_cfg_request *req, 603 int timeout_msec) 604 { 605 unsigned long timeout = msecs_to_jiffies(timeout_msec); 606 struct tb_cfg_result res = { 0 }; 607 DECLARE_COMPLETION_ONSTACK(done); 608 int ret; 609 610 ret = tb_cfg_request(ctl, req, tb_cfg_request_complete, &done); 611 if (ret) { 612 res.err = ret; 613 return res; 614 } 615 616 if (!wait_for_completion_timeout(&done, timeout)) 617 tb_cfg_request_cancel(req, -ETIMEDOUT); 618 619 flush_work(&req->work); 620 621 return req->result; 622 } 623 624 /* public interface, alloc/start/stop/free */ 625 626 /** 627 * tb_ctl_alloc() - allocate a control channel 628 * @nhi: Pointer to NHI 629 * @index: Domain number 630 * @timeout_msec: Default timeout used with non-raw control messages 631 * @cb: Callback called for plug events 632 * @cb_data: Data passed to @cb 633 * 634 * cb will be invoked once for every hot plug event. 635 * 636 * Return: Returns a pointer on success or NULL on failure. 637 */ 638 struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, int index, int timeout_msec, 639 event_cb cb, void *cb_data) 640 { 641 int i; 642 struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL); 643 if (!ctl) 644 return NULL; 645 646 ctl->nhi = nhi; 647 ctl->index = index; 648 ctl->timeout_msec = timeout_msec; 649 ctl->callback = cb; 650 ctl->callback_data = cb_data; 651 652 mutex_init(&ctl->request_queue_lock); 653 INIT_LIST_HEAD(&ctl->request_queue); 654 ctl->frame_pool = dma_pool_create("thunderbolt_ctl", &nhi->pdev->dev, 655 TB_FRAME_SIZE, 4, 0); 656 if (!ctl->frame_pool) 657 goto err; 658 659 ctl->tx = tb_ring_alloc_tx(nhi, 0, 10, RING_FLAG_NO_SUSPEND); 660 if (!ctl->tx) 661 goto err; 662 663 ctl->rx = tb_ring_alloc_rx(nhi, 0, 10, RING_FLAG_NO_SUSPEND, 0, 0xffff, 664 0xffff, NULL, NULL); 665 if (!ctl->rx) 666 goto err; 667 668 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) { 669 ctl->rx_packets[i] = tb_ctl_pkg_alloc(ctl); 670 if (!ctl->rx_packets[i]) 671 goto err; 672 ctl->rx_packets[i]->frame.callback = tb_ctl_rx_callback; 673 } 674 675 tb_ctl_dbg(ctl, "control channel created\n"); 676 return ctl; 677 err: 678 tb_ctl_free(ctl); 679 return NULL; 680 } 681 682 /** 683 * tb_ctl_free() - free a control channel 684 * @ctl: Control channel to free 685 * 686 * Must be called after tb_ctl_stop. 687 * 688 * Must NOT be called from ctl->callback. 689 */ 690 void tb_ctl_free(struct tb_ctl *ctl) 691 { 692 int i; 693 694 if (!ctl) 695 return; 696 697 if (ctl->rx) 698 tb_ring_free(ctl->rx); 699 if (ctl->tx) 700 tb_ring_free(ctl->tx); 701 702 /* free RX packets */ 703 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) 704 tb_ctl_pkg_free(ctl->rx_packets[i]); 705 706 707 dma_pool_destroy(ctl->frame_pool); 708 kfree(ctl); 709 } 710 711 /** 712 * tb_ctl_start() - start/resume the control channel 713 * @ctl: Control channel to start 714 */ 715 void tb_ctl_start(struct tb_ctl *ctl) 716 { 717 int i; 718 tb_ctl_dbg(ctl, "control channel starting...\n"); 719 tb_ring_start(ctl->tx); /* is used to ack hotplug packets, start first */ 720 tb_ring_start(ctl->rx); 721 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) 722 tb_ctl_rx_submit(ctl->rx_packets[i]); 723 724 ctl->running = true; 725 } 726 727 /** 728 * tb_ctl_stop() - pause the control channel 729 * @ctl: Control channel to stop 730 * 731 * All invocations of ctl->callback will have finished after this method 732 * returns. 733 * 734 * Must NOT be called from ctl->callback. 735 */ 736 void tb_ctl_stop(struct tb_ctl *ctl) 737 { 738 mutex_lock(&ctl->request_queue_lock); 739 ctl->running = false; 740 mutex_unlock(&ctl->request_queue_lock); 741 742 tb_ring_stop(ctl->rx); 743 tb_ring_stop(ctl->tx); 744 745 if (!list_empty(&ctl->request_queue)) 746 tb_ctl_WARN(ctl, "dangling request in request_queue\n"); 747 INIT_LIST_HEAD(&ctl->request_queue); 748 tb_ctl_dbg(ctl, "control channel stopped\n"); 749 } 750 751 /* public interface, commands */ 752 753 /** 754 * tb_cfg_ack_notification() - Ack notification 755 * @ctl: Control channel to use 756 * @route: Router that originated the event 757 * @error: Pointer to the notification package 758 * 759 * Call this as response for non-plug notification to ack it. Returns 760 * %0 on success or an error code on failure. 761 */ 762 int tb_cfg_ack_notification(struct tb_ctl *ctl, u64 route, 763 const struct cfg_error_pkg *error) 764 { 765 struct cfg_ack_pkg pkg = { 766 .header = tb_cfg_make_header(route), 767 }; 768 const char *name; 769 770 switch (error->error) { 771 case TB_CFG_ERROR_LINK_ERROR: 772 name = "link error"; 773 break; 774 case TB_CFG_ERROR_HEC_ERROR_DETECTED: 775 name = "HEC error"; 776 break; 777 case TB_CFG_ERROR_FLOW_CONTROL_ERROR: 778 name = "flow control error"; 779 break; 780 case TB_CFG_ERROR_DP_BW: 781 name = "DP_BW"; 782 break; 783 case TB_CFG_ERROR_ROP_CMPLT: 784 name = "router operation completion"; 785 break; 786 case TB_CFG_ERROR_POP_CMPLT: 787 name = "port operation completion"; 788 break; 789 case TB_CFG_ERROR_PCIE_WAKE: 790 name = "PCIe wake"; 791 break; 792 case TB_CFG_ERROR_DP_CON_CHANGE: 793 name = "DP connector change"; 794 break; 795 case TB_CFG_ERROR_DPTX_DISCOVERY: 796 name = "DPTX discovery"; 797 break; 798 case TB_CFG_ERROR_LINK_RECOVERY: 799 name = "link recovery"; 800 break; 801 case TB_CFG_ERROR_ASYM_LINK: 802 name = "asymmetric link"; 803 break; 804 default: 805 name = "unknown"; 806 break; 807 } 808 809 tb_ctl_dbg(ctl, "acking %s (%#x) notification on %llx\n", name, 810 error->error, route); 811 812 return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_NOTIFY_ACK); 813 } 814 815 /** 816 * tb_cfg_ack_plug() - Ack hot plug/unplug event 817 * @ctl: Control channel to use 818 * @route: Router that originated the event 819 * @port: Port where the hot plug/unplug happened 820 * @unplug: Ack hot plug or unplug 821 * 822 * Call this as response for hot plug/unplug event to ack it. 823 * Returns %0 on success or an error code on failure. 824 */ 825 int tb_cfg_ack_plug(struct tb_ctl *ctl, u64 route, u32 port, bool unplug) 826 { 827 struct cfg_error_pkg pkg = { 828 .header = tb_cfg_make_header(route), 829 .port = port, 830 .error = TB_CFG_ERROR_ACK_PLUG_EVENT, 831 .pg = unplug ? TB_CFG_ERROR_PG_HOT_UNPLUG 832 : TB_CFG_ERROR_PG_HOT_PLUG, 833 }; 834 tb_ctl_dbg(ctl, "acking hot %splug event on %llx:%u\n", 835 unplug ? "un" : "", route, port); 836 return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR); 837 } 838 839 static bool tb_cfg_match(const struct tb_cfg_request *req, 840 const struct ctl_pkg *pkg) 841 { 842 u64 route = tb_cfg_get_route(pkg->buffer) & ~BIT_ULL(63); 843 844 if (pkg->frame.eof == TB_CFG_PKG_ERROR) 845 return true; 846 847 if (pkg->frame.eof != req->response_type) 848 return false; 849 if (route != tb_cfg_get_route(req->request)) 850 return false; 851 if (pkg->frame.size != req->response_size) 852 return false; 853 854 if (pkg->frame.eof == TB_CFG_PKG_READ || 855 pkg->frame.eof == TB_CFG_PKG_WRITE) { 856 const struct cfg_read_pkg *req_hdr = req->request; 857 const struct cfg_read_pkg *res_hdr = pkg->buffer; 858 859 if (req_hdr->addr.seq != res_hdr->addr.seq) 860 return false; 861 } 862 863 return true; 864 } 865 866 static bool tb_cfg_copy(struct tb_cfg_request *req, const struct ctl_pkg *pkg) 867 { 868 struct tb_cfg_result res; 869 870 /* Now make sure it is in expected format */ 871 res = parse_header(pkg, req->response_size, req->response_type, 872 tb_cfg_get_route(req->request)); 873 if (!res.err) 874 memcpy(req->response, pkg->buffer, req->response_size); 875 876 req->result = res; 877 878 /* Always complete when first response is received */ 879 return true; 880 } 881 882 /** 883 * tb_cfg_reset() - send a reset packet and wait for a response 884 * @ctl: Control channel pointer 885 * @route: Router string for the router to send reset 886 * 887 * If the switch at route is incorrectly configured then we will not receive a 888 * reply (even though the switch will reset). The caller should check for 889 * -ETIMEDOUT and attempt to reconfigure the switch. 890 */ 891 struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route) 892 { 893 struct cfg_reset_pkg request = { .header = tb_cfg_make_header(route) }; 894 struct tb_cfg_result res = { 0 }; 895 struct tb_cfg_header reply; 896 struct tb_cfg_request *req; 897 898 req = tb_cfg_request_alloc(); 899 if (!req) { 900 res.err = -ENOMEM; 901 return res; 902 } 903 904 req->match = tb_cfg_match; 905 req->copy = tb_cfg_copy; 906 req->request = &request; 907 req->request_size = sizeof(request); 908 req->request_type = TB_CFG_PKG_RESET; 909 req->response = &reply; 910 req->response_size = sizeof(reply); 911 req->response_type = TB_CFG_PKG_RESET; 912 913 res = tb_cfg_request_sync(ctl, req, ctl->timeout_msec); 914 915 tb_cfg_request_put(req); 916 917 return res; 918 } 919 920 /** 921 * tb_cfg_read_raw() - read from config space into buffer 922 * @ctl: Pointer to the control channel 923 * @buffer: Buffer where the data is read 924 * @route: Route string of the router 925 * @port: Port number when reading from %TB_CFG_PORT, %0 otherwise 926 * @space: Config space selector 927 * @offset: Dword word offset of the register to start reading 928 * @length: Number of dwords to read 929 * @timeout_msec: Timeout in ms how long to wait for the response 930 * 931 * Reads from router config space without translating the possible error. 932 */ 933 struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer, 934 u64 route, u32 port, enum tb_cfg_space space, 935 u32 offset, u32 length, int timeout_msec) 936 { 937 struct tb_cfg_result res = { 0 }; 938 struct cfg_read_pkg request = { 939 .header = tb_cfg_make_header(route), 940 .addr = { 941 .port = port, 942 .space = space, 943 .offset = offset, 944 .length = length, 945 }, 946 }; 947 struct cfg_write_pkg reply; 948 int retries = 0; 949 950 while (retries < TB_CTL_RETRIES) { 951 struct tb_cfg_request *req; 952 953 req = tb_cfg_request_alloc(); 954 if (!req) { 955 res.err = -ENOMEM; 956 return res; 957 } 958 959 request.addr.seq = retries++; 960 961 req->match = tb_cfg_match; 962 req->copy = tb_cfg_copy; 963 req->request = &request; 964 req->request_size = sizeof(request); 965 req->request_type = TB_CFG_PKG_READ; 966 req->response = &reply; 967 req->response_size = 12 + 4 * length; 968 req->response_type = TB_CFG_PKG_READ; 969 970 res = tb_cfg_request_sync(ctl, req, timeout_msec); 971 972 tb_cfg_request_put(req); 973 974 if (res.err != -ETIMEDOUT) 975 break; 976 977 /* Wait a bit (arbitrary time) until we send a retry */ 978 usleep_range(10, 100); 979 } 980 981 if (res.err) 982 return res; 983 984 res.response_port = reply.addr.port; 985 res.err = check_config_address(reply.addr, space, offset, length); 986 if (!res.err) 987 memcpy(buffer, &reply.data, 4 * length); 988 return res; 989 } 990 991 /** 992 * tb_cfg_write_raw() - write from buffer into config space 993 * @ctl: Pointer to the control channel 994 * @buffer: Data to write 995 * @route: Route string of the router 996 * @port: Port number when writing to %TB_CFG_PORT, %0 otherwise 997 * @space: Config space selector 998 * @offset: Dword word offset of the register to start writing 999 * @length: Number of dwords to write 1000 * @timeout_msec: Timeout in ms how long to wait for the response 1001 * 1002 * Writes to router config space without translating the possible error. 1003 */ 1004 struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, const void *buffer, 1005 u64 route, u32 port, enum tb_cfg_space space, 1006 u32 offset, u32 length, int timeout_msec) 1007 { 1008 struct tb_cfg_result res = { 0 }; 1009 struct cfg_write_pkg request = { 1010 .header = tb_cfg_make_header(route), 1011 .addr = { 1012 .port = port, 1013 .space = space, 1014 .offset = offset, 1015 .length = length, 1016 }, 1017 }; 1018 struct cfg_read_pkg reply; 1019 int retries = 0; 1020 1021 memcpy(&request.data, buffer, length * 4); 1022 1023 while (retries < TB_CTL_RETRIES) { 1024 struct tb_cfg_request *req; 1025 1026 req = tb_cfg_request_alloc(); 1027 if (!req) { 1028 res.err = -ENOMEM; 1029 return res; 1030 } 1031 1032 request.addr.seq = retries++; 1033 1034 req->match = tb_cfg_match; 1035 req->copy = tb_cfg_copy; 1036 req->request = &request; 1037 req->request_size = 12 + 4 * length; 1038 req->request_type = TB_CFG_PKG_WRITE; 1039 req->response = &reply; 1040 req->response_size = sizeof(reply); 1041 req->response_type = TB_CFG_PKG_WRITE; 1042 1043 res = tb_cfg_request_sync(ctl, req, timeout_msec); 1044 1045 tb_cfg_request_put(req); 1046 1047 if (res.err != -ETIMEDOUT) 1048 break; 1049 1050 /* Wait a bit (arbitrary time) until we send a retry */ 1051 usleep_range(10, 100); 1052 } 1053 1054 if (res.err) 1055 return res; 1056 1057 res.response_port = reply.addr.port; 1058 res.err = check_config_address(reply.addr, space, offset, length); 1059 return res; 1060 } 1061 1062 static int tb_cfg_get_error(struct tb_ctl *ctl, enum tb_cfg_space space, 1063 const struct tb_cfg_result *res) 1064 { 1065 /* 1066 * For unimplemented ports access to port config space may return 1067 * TB_CFG_ERROR_INVALID_CONFIG_SPACE (alternatively their type is 1068 * set to TB_TYPE_INACTIVE). In the former case return -ENODEV so 1069 * that the caller can mark the port as disabled. 1070 */ 1071 if (space == TB_CFG_PORT && 1072 res->tb_error == TB_CFG_ERROR_INVALID_CONFIG_SPACE) 1073 return -ENODEV; 1074 1075 tb_cfg_print_error(ctl, res); 1076 1077 if (res->tb_error == TB_CFG_ERROR_LOCK) 1078 return -EACCES; 1079 if (res->tb_error == TB_CFG_ERROR_PORT_NOT_CONNECTED) 1080 return -ENOTCONN; 1081 1082 return -EIO; 1083 } 1084 1085 int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port, 1086 enum tb_cfg_space space, u32 offset, u32 length) 1087 { 1088 struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port, 1089 space, offset, length, ctl->timeout_msec); 1090 switch (res.err) { 1091 case 0: 1092 /* Success */ 1093 break; 1094 1095 case 1: 1096 /* Thunderbolt error, tb_error holds the actual number */ 1097 return tb_cfg_get_error(ctl, space, &res); 1098 1099 case -ETIMEDOUT: 1100 tb_ctl_warn(ctl, "%llx: timeout reading config space %u from %#x\n", 1101 route, space, offset); 1102 break; 1103 1104 default: 1105 WARN(1, "tb_cfg_read: %d\n", res.err); 1106 break; 1107 } 1108 return res.err; 1109 } 1110 1111 int tb_cfg_write(struct tb_ctl *ctl, const void *buffer, u64 route, u32 port, 1112 enum tb_cfg_space space, u32 offset, u32 length) 1113 { 1114 struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port, 1115 space, offset, length, ctl->timeout_msec); 1116 switch (res.err) { 1117 case 0: 1118 /* Success */ 1119 break; 1120 1121 case 1: 1122 /* Thunderbolt error, tb_error holds the actual number */ 1123 return tb_cfg_get_error(ctl, space, &res); 1124 1125 case -ETIMEDOUT: 1126 tb_ctl_warn(ctl, "%llx: timeout writing config space %u to %#x\n", 1127 route, space, offset); 1128 break; 1129 1130 default: 1131 WARN(1, "tb_cfg_write: %d\n", res.err); 1132 break; 1133 } 1134 return res.err; 1135 } 1136 1137 /** 1138 * tb_cfg_get_upstream_port() - get upstream port number of switch at route 1139 * @ctl: Pointer to the control channel 1140 * @route: Route string of the router 1141 * 1142 * Reads the first dword from the switches TB_CFG_SWITCH config area and 1143 * returns the port number from which the reply originated. 1144 * 1145 * Return: Returns the upstream port number on success or an error code on 1146 * failure. 1147 */ 1148 int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route) 1149 { 1150 u32 dummy; 1151 struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0, 1152 TB_CFG_SWITCH, 0, 1, 1153 ctl->timeout_msec); 1154 if (res.err == 1) 1155 return -EIO; 1156 if (res.err) 1157 return res.err; 1158 return res.response_port; 1159 } 1160