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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
19#define TB_CTL_RX_PKG_COUNT 10
20#define TB_CTL_RETRIES 1
21
22/**
23 * struct tb_ctl - Thunderbolt control channel
24 * @nhi: Pointer to the NHI structure
25 * @tx: Transmit ring
26 * @rx: Receive ring
27 * @frame_pool: DMA pool for control messages
28 * @rx_packets: Received control messages
29 * @request_queue_lock: Lock protecting @request_queue
30 * @request_queue: List of outstanding requests
31 * @running: Is the control channel running at the moment
32 * @timeout_msec: Default timeout for non-raw control messages
33 * @callback: Callback called when hotplug message is received
34 * @callback_data: Data passed to @callback
35 */
36struct tb_ctl {
37 struct tb_nhi *nhi;
38 struct tb_ring *tx;
39 struct tb_ring *rx;
40
41 struct dma_pool *frame_pool;
42 struct ctl_pkg *rx_packets[TB_CTL_RX_PKG_COUNT];
43 struct mutex request_queue_lock;
44 struct list_head request_queue;
45 bool running;
46
47 int timeout_msec;
48 event_cb callback;
49 void *callback_data;
50};
51
52
53#define tb_ctl_WARN(ctl, format, arg...) \
54 dev_WARN(&(ctl)->nhi->pdev->dev, format, ## arg)
55
56#define tb_ctl_err(ctl, format, arg...) \
57 dev_err(&(ctl)->nhi->pdev->dev, format, ## arg)
58
59#define tb_ctl_warn(ctl, format, arg...) \
60 dev_warn(&(ctl)->nhi->pdev->dev, format, ## arg)
61
62#define tb_ctl_info(ctl, format, arg...) \
63 dev_info(&(ctl)->nhi->pdev->dev, format, ## arg)
64
65#define tb_ctl_dbg(ctl, format, arg...) \
66 dev_dbg(&(ctl)->nhi->pdev->dev, format, ## arg)
67
68static DECLARE_WAIT_QUEUE_HEAD(tb_cfg_request_cancel_queue);
69/* Serializes access to request kref_get/put */
70static DEFINE_MUTEX(tb_cfg_request_lock);
71
72/**
73 * tb_cfg_request_alloc() - Allocates a new config request
74 *
75 * This is refcounted object so when you are done with this, call
76 * tb_cfg_request_put() to it.
77 */
78struct tb_cfg_request *tb_cfg_request_alloc(void)
79{
80 struct tb_cfg_request *req;
81
82 req = kzalloc(sizeof(*req), GFP_KERNEL);
83 if (!req)
84 return NULL;
85
86 kref_init(&req->kref);
87
88 return req;
89}
90
91/**
92 * tb_cfg_request_get() - Increase refcount of a request
93 * @req: Request whose refcount is increased
94 */
95void tb_cfg_request_get(struct tb_cfg_request *req)
96{
97 mutex_lock(&tb_cfg_request_lock);
98 kref_get(&req->kref);
99 mutex_unlock(&tb_cfg_request_lock);
100}
101
102static void tb_cfg_request_destroy(struct kref *kref)
103{
104 struct tb_cfg_request *req = container_of(kref, typeof(*req), kref);
105
106 kfree(req);
107}
108
109/**
110 * tb_cfg_request_put() - Decrease refcount and possibly release the request
111 * @req: Request whose refcount is decreased
112 *
113 * Call this function when you are done with the request. When refcount
114 * goes to %0 the object is released.
115 */
116void tb_cfg_request_put(struct tb_cfg_request *req)
117{
118 mutex_lock(&tb_cfg_request_lock);
119 kref_put(&req->kref, tb_cfg_request_destroy);
120 mutex_unlock(&tb_cfg_request_lock);
121}
122
123static int tb_cfg_request_enqueue(struct tb_ctl *ctl,
124 struct tb_cfg_request *req)
125{
126 WARN_ON(test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags));
127 WARN_ON(req->ctl);
128
129 mutex_lock(&ctl->request_queue_lock);
130 if (!ctl->running) {
131 mutex_unlock(&ctl->request_queue_lock);
132 return -ENOTCONN;
133 }
134 req->ctl = ctl;
135 list_add_tail(&req->list, &ctl->request_queue);
136 set_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);
137 mutex_unlock(&ctl->request_queue_lock);
138 return 0;
139}
140
141static void tb_cfg_request_dequeue(struct tb_cfg_request *req)
142{
143 struct tb_ctl *ctl = req->ctl;
144
145 mutex_lock(&ctl->request_queue_lock);
146 list_del(&req->list);
147 clear_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);
148 if (test_bit(TB_CFG_REQUEST_CANCELED, &req->flags))
149 wake_up(&tb_cfg_request_cancel_queue);
150 mutex_unlock(&ctl->request_queue_lock);
151}
152
153static bool tb_cfg_request_is_active(struct tb_cfg_request *req)
154{
155 return test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);
156}
157
158static struct tb_cfg_request *
159tb_cfg_request_find(struct tb_ctl *ctl, struct ctl_pkg *pkg)
160{
161 struct tb_cfg_request *req;
162 bool found = false;
163
164 mutex_lock(&pkg->ctl->request_queue_lock);
165 list_for_each_entry(req, &pkg->ctl->request_queue, list) {
166 tb_cfg_request_get(req);
167 if (req->match(req, pkg)) {
168 found = true;
169 break;
170 }
171 tb_cfg_request_put(req);
172 }
173 mutex_unlock(&pkg->ctl->request_queue_lock);
174
175 return found ? req : NULL;
176}
177
178/* utility functions */
179
180
181static int check_header(const struct ctl_pkg *pkg, u32 len,
182 enum tb_cfg_pkg_type type, u64 route)
183{
184 struct tb_cfg_header *header = pkg->buffer;
185
186 /* check frame, TODO: frame flags */
187 if (WARN(len != pkg->frame.size,
188 "wrong framesize (expected %#x, got %#x)\n",
189 len, pkg->frame.size))
190 return -EIO;
191 if (WARN(type != pkg->frame.eof, "wrong eof (expected %#x, got %#x)\n",
192 type, pkg->frame.eof))
193 return -EIO;
194 if (WARN(pkg->frame.sof, "wrong sof (expected 0x0, got %#x)\n",
195 pkg->frame.sof))
196 return -EIO;
197
198 /* check header */
199 if (WARN(header->unknown != 1 << 9,
200 "header->unknown is %#x\n", header->unknown))
201 return -EIO;
202 if (WARN(route != tb_cfg_get_route(header),
203 "wrong route (expected %llx, got %llx)",
204 route, tb_cfg_get_route(header)))
205 return -EIO;
206 return 0;
207}
208
209static int check_config_address(struct tb_cfg_address addr,
210 enum tb_cfg_space space, u32 offset,
211 u32 length)
212{
213 if (WARN(addr.zero, "addr.zero is %#x\n", addr.zero))
214 return -EIO;
215 if (WARN(space != addr.space, "wrong space (expected %x, got %x\n)",
216 space, addr.space))
217 return -EIO;
218 if (WARN(offset != addr.offset, "wrong offset (expected %x, got %x\n)",
219 offset, addr.offset))
220 return -EIO;
221 if (WARN(length != addr.length, "wrong space (expected %x, got %x\n)",
222 length, addr.length))
223 return -EIO;
224 /*
225 * We cannot check addr->port as it is set to the upstream port of the
226 * sender.
227 */
228 return 0;
229}
230
231static struct tb_cfg_result decode_error(const struct ctl_pkg *response)
232{
233 struct cfg_error_pkg *pkg = response->buffer;
234 struct tb_ctl *ctl = response->ctl;
235 struct tb_cfg_result res = { 0 };
236 res.response_route = tb_cfg_get_route(&pkg->header);
237 res.response_port = 0;
238 res.err = check_header(response, sizeof(*pkg), TB_CFG_PKG_ERROR,
239 tb_cfg_get_route(&pkg->header));
240 if (res.err)
241 return res;
242
243 if (pkg->zero1)
244 tb_ctl_warn(ctl, "pkg->zero1 is %#x\n", pkg->zero1);
245 if (pkg->zero2)
246 tb_ctl_warn(ctl, "pkg->zero2 is %#x\n", pkg->zero2);
247 if (pkg->zero3)
248 tb_ctl_warn(ctl, "pkg->zero3 is %#x\n", pkg->zero3);
249
250 res.err = 1;
251 res.tb_error = pkg->error;
252 res.response_port = pkg->port;
253 return res;
254
255}
256
257static struct tb_cfg_result parse_header(const struct ctl_pkg *pkg, u32 len,
258 enum tb_cfg_pkg_type type, u64 route)
259{
260 struct tb_cfg_header *header = pkg->buffer;
261 struct tb_cfg_result res = { 0 };
262
263 if (pkg->frame.eof == TB_CFG_PKG_ERROR)
264 return decode_error(pkg);
265
266 res.response_port = 0; /* will be updated later for cfg_read/write */
267 res.response_route = tb_cfg_get_route(header);
268 res.err = check_header(pkg, len, type, route);
269 return res;
270}
271
272static void tb_cfg_print_error(struct tb_ctl *ctl,
273 const struct tb_cfg_result *res)
274{
275 WARN_ON(res->err != 1);
276 switch (res->tb_error) {
277 case TB_CFG_ERROR_PORT_NOT_CONNECTED:
278 /* Port is not connected. This can happen during surprise
279 * removal. Do not warn. */
280 return;
281 case TB_CFG_ERROR_INVALID_CONFIG_SPACE:
282 /*
283 * Invalid cfg_space/offset/length combination in
284 * cfg_read/cfg_write.
285 */
286 tb_ctl_dbg(ctl, "%llx:%x: invalid config space or offset\n",
287 res->response_route, res->response_port);
288 return;
289 case TB_CFG_ERROR_NO_SUCH_PORT:
290 /*
291 * - The route contains a non-existent port.
292 * - The route contains a non-PHY port (e.g. PCIe).
293 * - The port in cfg_read/cfg_write does not exist.
294 */
295 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n",
296 res->response_route, res->response_port);
297 return;
298 case TB_CFG_ERROR_LOOP:
299 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n",
300 res->response_route, res->response_port);
301 return;
302 case TB_CFG_ERROR_LOCK:
303 tb_ctl_warn(ctl, "%llx:%x: downstream port is locked\n",
304 res->response_route, res->response_port);
305 return;
306 default:
307 /* 5,6,7,9 and 11 are also valid error codes */
308 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n",
309 res->response_route, res->response_port);
310 return;
311 }
312}
313
314static __be32 tb_crc(const void *data, size_t len)
315{
316 return cpu_to_be32(~__crc32c_le(~0, data, len));
317}
318
319static void tb_ctl_pkg_free(struct ctl_pkg *pkg)
320{
321 if (pkg) {
322 dma_pool_free(pkg->ctl->frame_pool,
323 pkg->buffer, pkg->frame.buffer_phy);
324 kfree(pkg);
325 }
326}
327
328static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl)
329{
330 struct ctl_pkg *pkg = kzalloc(sizeof(*pkg), GFP_KERNEL);
331 if (!pkg)
332 return NULL;
333 pkg->ctl = ctl;
334 pkg->buffer = dma_pool_alloc(ctl->frame_pool, GFP_KERNEL,
335 &pkg->frame.buffer_phy);
336 if (!pkg->buffer) {
337 kfree(pkg);
338 return NULL;
339 }
340 return pkg;
341}
342
343
344/* RX/TX handling */
345
346static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
347 bool canceled)
348{
349 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
350 tb_ctl_pkg_free(pkg);
351}
352
353/*
354 * tb_cfg_tx() - transmit a packet on the control channel
355 *
356 * len must be a multiple of four.
357 *
358 * Return: Returns 0 on success or an error code on failure.
359 */
360static int tb_ctl_tx(struct tb_ctl *ctl, const void *data, size_t len,
361 enum tb_cfg_pkg_type type)
362{
363 int res;
364 struct ctl_pkg *pkg;
365 if (len % 4 != 0) { /* required for le->be conversion */
366 tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len);
367 return -EINVAL;
368 }
369 if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */
370 tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n",
371 len, TB_FRAME_SIZE - 4);
372 return -EINVAL;
373 }
374 pkg = tb_ctl_pkg_alloc(ctl);
375 if (!pkg)
376 return -ENOMEM;
377 pkg->frame.callback = tb_ctl_tx_callback;
378 pkg->frame.size = len + 4;
379 pkg->frame.sof = type;
380 pkg->frame.eof = type;
381 cpu_to_be32_array(pkg->buffer, data, len / 4);
382 *(__be32 *) (pkg->buffer + len) = tb_crc(pkg->buffer, len);
383
384 res = tb_ring_tx(ctl->tx, &pkg->frame);
385 if (res) /* ring is stopped */
386 tb_ctl_pkg_free(pkg);
387 return res;
388}
389
390/*
391 * tb_ctl_handle_event() - acknowledge a plug event, invoke ctl->callback
392 */
393static bool tb_ctl_handle_event(struct tb_ctl *ctl, enum tb_cfg_pkg_type type,
394 struct ctl_pkg *pkg, size_t size)
395{
396 return ctl->callback(ctl->callback_data, type, pkg->buffer, size);
397}
398
399static 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
409static int tb_async_error(const struct ctl_pkg *pkg)
410{
411 const struct cfg_error_pkg *error = (const struct cfg_error_pkg *)pkg;
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 return true;
421
422 default:
423 return false;
424 }
425}
426
427static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame,
428 bool canceled)
429{
430 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
431 struct tb_cfg_request *req;
432 __be32 crc32;
433
434 if (canceled)
435 return; /*
436 * ring is stopped, packet is referenced from
437 * ctl->rx_packets.
438 */
439
440 if (frame->size < 4 || frame->size % 4 != 0) {
441 tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n",
442 frame->size);
443 goto rx;
444 }
445
446 frame->size -= 4; /* remove checksum */
447 crc32 = tb_crc(pkg->buffer, frame->size);
448 be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4);
449
450 switch (frame->eof) {
451 case TB_CFG_PKG_READ:
452 case TB_CFG_PKG_WRITE:
453 case TB_CFG_PKG_ERROR:
454 case TB_CFG_PKG_OVERRIDE:
455 case TB_CFG_PKG_RESET:
456 if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {
457 tb_ctl_err(pkg->ctl,
458 "RX: checksum mismatch, dropping packet\n");
459 goto rx;
460 }
461 if (tb_async_error(pkg)) {
462 tb_ctl_handle_event(pkg->ctl, frame->eof,
463 pkg, frame->size);
464 goto rx;
465 }
466 break;
467
468 case TB_CFG_PKG_EVENT:
469 case TB_CFG_PKG_XDOMAIN_RESP:
470 case TB_CFG_PKG_XDOMAIN_REQ:
471 if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {
472 tb_ctl_err(pkg->ctl,
473 "RX: checksum mismatch, dropping packet\n");
474 goto rx;
475 }
476 fallthrough;
477 case TB_CFG_PKG_ICM_EVENT:
478 if (tb_ctl_handle_event(pkg->ctl, frame->eof, pkg, frame->size))
479 goto rx;
480 break;
481
482 default:
483 break;
484 }
485
486 /*
487 * The received packet will be processed only if there is an
488 * active request and that the packet is what is expected. This
489 * prevents packets such as replies coming after timeout has
490 * triggered from messing with the active requests.
491 */
492 req = tb_cfg_request_find(pkg->ctl, pkg);
493 if (req) {
494 if (req->copy(req, pkg))
495 schedule_work(&req->work);
496 tb_cfg_request_put(req);
497 }
498
499rx:
500 tb_ctl_rx_submit(pkg);
501}
502
503static void tb_cfg_request_work(struct work_struct *work)
504{
505 struct tb_cfg_request *req = container_of(work, typeof(*req), work);
506
507 if (!test_bit(TB_CFG_REQUEST_CANCELED, &req->flags))
508 req->callback(req->callback_data);
509
510 tb_cfg_request_dequeue(req);
511 tb_cfg_request_put(req);
512}
513
514/**
515 * tb_cfg_request() - Start control request not waiting for it to complete
516 * @ctl: Control channel to use
517 * @req: Request to start
518 * @callback: Callback called when the request is completed
519 * @callback_data: Data to be passed to @callback
520 *
521 * This queues @req on the given control channel without waiting for it
522 * to complete. When the request completes @callback is called.
523 */
524int tb_cfg_request(struct tb_ctl *ctl, struct tb_cfg_request *req,
525 void (*callback)(void *), void *callback_data)
526{
527 int ret;
528
529 req->flags = 0;
530 req->callback = callback;
531 req->callback_data = callback_data;
532 INIT_WORK(&req->work, tb_cfg_request_work);
533 INIT_LIST_HEAD(&req->list);
534
535 tb_cfg_request_get(req);
536 ret = tb_cfg_request_enqueue(ctl, req);
537 if (ret)
538 goto err_put;
539
540 ret = tb_ctl_tx(ctl, req->request, req->request_size,
541 req->request_type);
542 if (ret)
543 goto err_dequeue;
544
545 if (!req->response)
546 schedule_work(&req->work);
547
548 return 0;
549
550err_dequeue:
551 tb_cfg_request_dequeue(req);
552err_put:
553 tb_cfg_request_put(req);
554
555 return ret;
556}
557
558/**
559 * tb_cfg_request_cancel() - Cancel a control request
560 * @req: Request to cancel
561 * @err: Error to assign to the request
562 *
563 * This function can be used to cancel ongoing request. It will wait
564 * until the request is not active anymore.
565 */
566void tb_cfg_request_cancel(struct tb_cfg_request *req, int err)
567{
568 set_bit(TB_CFG_REQUEST_CANCELED, &req->flags);
569 schedule_work(&req->work);
570 wait_event(tb_cfg_request_cancel_queue, !tb_cfg_request_is_active(req));
571 req->result.err = err;
572}
573
574static void tb_cfg_request_complete(void *data)
575{
576 complete(data);
577}
578
579/**
580 * tb_cfg_request_sync() - Start control request and wait until it completes
581 * @ctl: Control channel to use
582 * @req: Request to start
583 * @timeout_msec: Timeout how long to wait @req to complete
584 *
585 * Starts a control request and waits until it completes. If timeout
586 * triggers the request is canceled before function returns. Note the
587 * caller needs to make sure only one message for given switch is active
588 * at a time.
589 */
590struct tb_cfg_result tb_cfg_request_sync(struct tb_ctl *ctl,
591 struct tb_cfg_request *req,
592 int timeout_msec)
593{
594 unsigned long timeout = msecs_to_jiffies(timeout_msec);
595 struct tb_cfg_result res = { 0 };
596 DECLARE_COMPLETION_ONSTACK(done);
597 int ret;
598
599 ret = tb_cfg_request(ctl, req, tb_cfg_request_complete, &done);
600 if (ret) {
601 res.err = ret;
602 return res;
603 }
604
605 if (!wait_for_completion_timeout(&done, timeout))
606 tb_cfg_request_cancel(req, -ETIMEDOUT);
607
608 flush_work(&req->work);
609
610 return req->result;
611}
612
613/* public interface, alloc/start/stop/free */
614
615/**
616 * tb_ctl_alloc() - allocate a control channel
617 * @nhi: Pointer to NHI
618 * @timeout_msec: Default timeout used with non-raw control messages
619 * @cb: Callback called for plug events
620 * @cb_data: Data passed to @cb
621 *
622 * cb will be invoked once for every hot plug event.
623 *
624 * Return: Returns a pointer on success or NULL on failure.
625 */
626struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, int timeout_msec, event_cb cb,
627 void *cb_data)
628{
629 int i;
630 struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
631 if (!ctl)
632 return NULL;
633 ctl->nhi = nhi;
634 ctl->timeout_msec = timeout_msec;
635 ctl->callback = cb;
636 ctl->callback_data = cb_data;
637
638 mutex_init(&ctl->request_queue_lock);
639 INIT_LIST_HEAD(&ctl->request_queue);
640 ctl->frame_pool = dma_pool_create("thunderbolt_ctl", &nhi->pdev->dev,
641 TB_FRAME_SIZE, 4, 0);
642 if (!ctl->frame_pool)
643 goto err;
644
645 ctl->tx = tb_ring_alloc_tx(nhi, 0, 10, RING_FLAG_NO_SUSPEND);
646 if (!ctl->tx)
647 goto err;
648
649 ctl->rx = tb_ring_alloc_rx(nhi, 0, 10, RING_FLAG_NO_SUSPEND, 0, 0xffff,
650 0xffff, NULL, NULL);
651 if (!ctl->rx)
652 goto err;
653
654 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) {
655 ctl->rx_packets[i] = tb_ctl_pkg_alloc(ctl);
656 if (!ctl->rx_packets[i])
657 goto err;
658 ctl->rx_packets[i]->frame.callback = tb_ctl_rx_callback;
659 }
660
661 tb_ctl_dbg(ctl, "control channel created\n");
662 return ctl;
663err:
664 tb_ctl_free(ctl);
665 return NULL;
666}
667
668/**
669 * tb_ctl_free() - free a control channel
670 * @ctl: Control channel to free
671 *
672 * Must be called after tb_ctl_stop.
673 *
674 * Must NOT be called from ctl->callback.
675 */
676void tb_ctl_free(struct tb_ctl *ctl)
677{
678 int i;
679
680 if (!ctl)
681 return;
682
683 if (ctl->rx)
684 tb_ring_free(ctl->rx);
685 if (ctl->tx)
686 tb_ring_free(ctl->tx);
687
688 /* free RX packets */
689 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
690 tb_ctl_pkg_free(ctl->rx_packets[i]);
691
692
693 dma_pool_destroy(ctl->frame_pool);
694 kfree(ctl);
695}
696
697/**
698 * tb_cfg_start() - start/resume the control channel
699 * @ctl: Control channel to start
700 */
701void tb_ctl_start(struct tb_ctl *ctl)
702{
703 int i;
704 tb_ctl_dbg(ctl, "control channel starting...\n");
705 tb_ring_start(ctl->tx); /* is used to ack hotplug packets, start first */
706 tb_ring_start(ctl->rx);
707 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
708 tb_ctl_rx_submit(ctl->rx_packets[i]);
709
710 ctl->running = true;
711}
712
713/**
714 * tb_ctrl_stop() - pause the control channel
715 * @ctl: Control channel to stop
716 *
717 * All invocations of ctl->callback will have finished after this method
718 * returns.
719 *
720 * Must NOT be called from ctl->callback.
721 */
722void tb_ctl_stop(struct tb_ctl *ctl)
723{
724 mutex_lock(&ctl->request_queue_lock);
725 ctl->running = false;
726 mutex_unlock(&ctl->request_queue_lock);
727
728 tb_ring_stop(ctl->rx);
729 tb_ring_stop(ctl->tx);
730
731 if (!list_empty(&ctl->request_queue))
732 tb_ctl_WARN(ctl, "dangling request in request_queue\n");
733 INIT_LIST_HEAD(&ctl->request_queue);
734 tb_ctl_dbg(ctl, "control channel stopped\n");
735}
736
737/* public interface, commands */
738
739/**
740 * tb_cfg_ack_plug() - Ack hot plug/unplug event
741 * @ctl: Control channel to use
742 * @route: Router that originated the event
743 * @port: Port where the hot plug/unplug happened
744 * @unplug: Ack hot plug or unplug
745 *
746 * Call this as response for hot plug/unplug event to ack it.
747 * Returns %0 on success or an error code on failure.
748 */
749int tb_cfg_ack_plug(struct tb_ctl *ctl, u64 route, u32 port, bool unplug)
750{
751 struct cfg_error_pkg pkg = {
752 .header = tb_cfg_make_header(route),
753 .port = port,
754 .error = TB_CFG_ERROR_ACK_PLUG_EVENT,
755 .pg = unplug ? TB_CFG_ERROR_PG_HOT_UNPLUG
756 : TB_CFG_ERROR_PG_HOT_PLUG,
757 };
758 tb_ctl_dbg(ctl, "acking hot %splug event on %llx:%x\n",
759 unplug ? "un" : "", route, port);
760 return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR);
761}
762
763static bool tb_cfg_match(const struct tb_cfg_request *req,
764 const struct ctl_pkg *pkg)
765{
766 u64 route = tb_cfg_get_route(pkg->buffer) & ~BIT_ULL(63);
767
768 if (pkg->frame.eof == TB_CFG_PKG_ERROR)
769 return true;
770
771 if (pkg->frame.eof != req->response_type)
772 return false;
773 if (route != tb_cfg_get_route(req->request))
774 return false;
775 if (pkg->frame.size != req->response_size)
776 return false;
777
778 if (pkg->frame.eof == TB_CFG_PKG_READ ||
779 pkg->frame.eof == TB_CFG_PKG_WRITE) {
780 const struct cfg_read_pkg *req_hdr = req->request;
781 const struct cfg_read_pkg *res_hdr = pkg->buffer;
782
783 if (req_hdr->addr.seq != res_hdr->addr.seq)
784 return false;
785 }
786
787 return true;
788}
789
790static bool tb_cfg_copy(struct tb_cfg_request *req, const struct ctl_pkg *pkg)
791{
792 struct tb_cfg_result res;
793
794 /* Now make sure it is in expected format */
795 res = parse_header(pkg, req->response_size, req->response_type,
796 tb_cfg_get_route(req->request));
797 if (!res.err)
798 memcpy(req->response, pkg->buffer, req->response_size);
799
800 req->result = res;
801
802 /* Always complete when first response is received */
803 return true;
804}
805
806/**
807 * tb_cfg_reset() - send a reset packet and wait for a response
808 * @ctl: Control channel pointer
809 * @route: Router string for the router to send reset
810 *
811 * If the switch at route is incorrectly configured then we will not receive a
812 * reply (even though the switch will reset). The caller should check for
813 * -ETIMEDOUT and attempt to reconfigure the switch.
814 */
815struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route)
816{
817 struct cfg_reset_pkg request = { .header = tb_cfg_make_header(route) };
818 struct tb_cfg_result res = { 0 };
819 struct tb_cfg_header reply;
820 struct tb_cfg_request *req;
821
822 req = tb_cfg_request_alloc();
823 if (!req) {
824 res.err = -ENOMEM;
825 return res;
826 }
827
828 req->match = tb_cfg_match;
829 req->copy = tb_cfg_copy;
830 req->request = &request;
831 req->request_size = sizeof(request);
832 req->request_type = TB_CFG_PKG_RESET;
833 req->response = &reply;
834 req->response_size = sizeof(reply);
835 req->response_type = TB_CFG_PKG_RESET;
836
837 res = tb_cfg_request_sync(ctl, req, ctl->timeout_msec);
838
839 tb_cfg_request_put(req);
840
841 return res;
842}
843
844/**
845 * tb_cfg_read_raw() - read from config space into buffer
846 * @ctl: Pointer to the control channel
847 * @buffer: Buffer where the data is read
848 * @route: Route string of the router
849 * @port: Port number when reading from %TB_CFG_PORT, %0 otherwise
850 * @space: Config space selector
851 * @offset: Dword word offset of the register to start reading
852 * @length: Number of dwords to read
853 * @timeout_msec: Timeout in ms how long to wait for the response
854 *
855 * Reads from router config space without translating the possible error.
856 */
857struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer,
858 u64 route, u32 port, enum tb_cfg_space space,
859 u32 offset, u32 length, int timeout_msec)
860{
861 struct tb_cfg_result res = { 0 };
862 struct cfg_read_pkg request = {
863 .header = tb_cfg_make_header(route),
864 .addr = {
865 .port = port,
866 .space = space,
867 .offset = offset,
868 .length = length,
869 },
870 };
871 struct cfg_write_pkg reply;
872 int retries = 0;
873
874 while (retries < TB_CTL_RETRIES) {
875 struct tb_cfg_request *req;
876
877 req = tb_cfg_request_alloc();
878 if (!req) {
879 res.err = -ENOMEM;
880 return res;
881 }
882
883 request.addr.seq = retries++;
884
885 req->match = tb_cfg_match;
886 req->copy = tb_cfg_copy;
887 req->request = &request;
888 req->request_size = sizeof(request);
889 req->request_type = TB_CFG_PKG_READ;
890 req->response = &reply;
891 req->response_size = 12 + 4 * length;
892 req->response_type = TB_CFG_PKG_READ;
893
894 res = tb_cfg_request_sync(ctl, req, timeout_msec);
895
896 tb_cfg_request_put(req);
897
898 if (res.err != -ETIMEDOUT)
899 break;
900
901 /* Wait a bit (arbitrary time) until we send a retry */
902 usleep_range(10, 100);
903 }
904
905 if (res.err)
906 return res;
907
908 res.response_port = reply.addr.port;
909 res.err = check_config_address(reply.addr, space, offset, length);
910 if (!res.err)
911 memcpy(buffer, &reply.data, 4 * length);
912 return res;
913}
914
915/**
916 * tb_cfg_write() - write from buffer into config space
917 * @ctl: Pointer to the control channel
918 * @buffer: Data to write
919 * @route: Route string of the router
920 * @port: Port number when writing to %TB_CFG_PORT, %0 otherwise
921 * @space: Config space selector
922 * @offset: Dword word offset of the register to start writing
923 * @length: Number of dwords to write
924 * @timeout_msec: Timeout in ms how long to wait for the response
925 *
926 * Writes to router config space without translating the possible error.
927 */
928struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, const void *buffer,
929 u64 route, u32 port, enum tb_cfg_space space,
930 u32 offset, u32 length, int timeout_msec)
931{
932 struct tb_cfg_result res = { 0 };
933 struct cfg_write_pkg request = {
934 .header = tb_cfg_make_header(route),
935 .addr = {
936 .port = port,
937 .space = space,
938 .offset = offset,
939 .length = length,
940 },
941 };
942 struct cfg_read_pkg reply;
943 int retries = 0;
944
945 memcpy(&request.data, buffer, length * 4);
946
947 while (retries < TB_CTL_RETRIES) {
948 struct tb_cfg_request *req;
949
950 req = tb_cfg_request_alloc();
951 if (!req) {
952 res.err = -ENOMEM;
953 return res;
954 }
955
956 request.addr.seq = retries++;
957
958 req->match = tb_cfg_match;
959 req->copy = tb_cfg_copy;
960 req->request = &request;
961 req->request_size = 12 + 4 * length;
962 req->request_type = TB_CFG_PKG_WRITE;
963 req->response = &reply;
964 req->response_size = sizeof(reply);
965 req->response_type = TB_CFG_PKG_WRITE;
966
967 res = tb_cfg_request_sync(ctl, req, timeout_msec);
968
969 tb_cfg_request_put(req);
970
971 if (res.err != -ETIMEDOUT)
972 break;
973
974 /* Wait a bit (arbitrary time) until we send a retry */
975 usleep_range(10, 100);
976 }
977
978 if (res.err)
979 return res;
980
981 res.response_port = reply.addr.port;
982 res.err = check_config_address(reply.addr, space, offset, length);
983 return res;
984}
985
986static int tb_cfg_get_error(struct tb_ctl *ctl, enum tb_cfg_space space,
987 const struct tb_cfg_result *res)
988{
989 /*
990 * For unimplemented ports access to port config space may return
991 * TB_CFG_ERROR_INVALID_CONFIG_SPACE (alternatively their type is
992 * set to TB_TYPE_INACTIVE). In the former case return -ENODEV so
993 * that the caller can mark the port as disabled.
994 */
995 if (space == TB_CFG_PORT &&
996 res->tb_error == TB_CFG_ERROR_INVALID_CONFIG_SPACE)
997 return -ENODEV;
998
999 tb_cfg_print_error(ctl, res);
1000
1001 if (res->tb_error == TB_CFG_ERROR_LOCK)
1002 return -EACCES;
1003 else if (res->tb_error == TB_CFG_ERROR_PORT_NOT_CONNECTED)
1004 return -ENOTCONN;
1005
1006 return -EIO;
1007}
1008
1009int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,
1010 enum tb_cfg_space space, u32 offset, u32 length)
1011{
1012 struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port,
1013 space, offset, length, ctl->timeout_msec);
1014 switch (res.err) {
1015 case 0:
1016 /* Success */
1017 break;
1018
1019 case 1:
1020 /* Thunderbolt error, tb_error holds the actual number */
1021 return tb_cfg_get_error(ctl, space, &res);
1022
1023 case -ETIMEDOUT:
1024 tb_ctl_warn(ctl, "%llx: timeout reading config space %u from %#x\n",
1025 route, space, offset);
1026 break;
1027
1028 default:
1029 WARN(1, "tb_cfg_read: %d\n", res.err);
1030 break;
1031 }
1032 return res.err;
1033}
1034
1035int tb_cfg_write(struct tb_ctl *ctl, const void *buffer, u64 route, u32 port,
1036 enum tb_cfg_space space, u32 offset, u32 length)
1037{
1038 struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port,
1039 space, offset, length, ctl->timeout_msec);
1040 switch (res.err) {
1041 case 0:
1042 /* Success */
1043 break;
1044
1045 case 1:
1046 /* Thunderbolt error, tb_error holds the actual number */
1047 return tb_cfg_get_error(ctl, space, &res);
1048
1049 case -ETIMEDOUT:
1050 tb_ctl_warn(ctl, "%llx: timeout writing config space %u to %#x\n",
1051 route, space, offset);
1052 break;
1053
1054 default:
1055 WARN(1, "tb_cfg_write: %d\n", res.err);
1056 break;
1057 }
1058 return res.err;
1059}
1060
1061/**
1062 * tb_cfg_get_upstream_port() - get upstream port number of switch at route
1063 * @ctl: Pointer to the control channel
1064 * @route: Route string of the router
1065 *
1066 * Reads the first dword from the switches TB_CFG_SWITCH config area and
1067 * returns the port number from which the reply originated.
1068 *
1069 * Return: Returns the upstream port number on success or an error code on
1070 * failure.
1071 */
1072int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route)
1073{
1074 u32 dummy;
1075 struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0,
1076 TB_CFG_SWITCH, 0, 1,
1077 ctl->timeout_msec);
1078 if (res.err == 1)
1079 return -EIO;
1080 if (res.err)
1081 return res.err;
1082 return res.response_port;
1083}