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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 4
21
22/**
23 * struct tb_cfg - thunderbolt control channel
24 */
25struct tb_ctl {
26 struct tb_nhi *nhi;
27 struct tb_ring *tx;
28 struct tb_ring *rx;
29
30 struct dma_pool *frame_pool;
31 struct ctl_pkg *rx_packets[TB_CTL_RX_PKG_COUNT];
32 struct mutex request_queue_lock;
33 struct list_head request_queue;
34 bool running;
35
36 event_cb callback;
37 void *callback_data;
38};
39
40
41#define tb_ctl_WARN(ctl, format, arg...) \
42 dev_WARN(&(ctl)->nhi->pdev->dev, format, ## arg)
43
44#define tb_ctl_err(ctl, format, arg...) \
45 dev_err(&(ctl)->nhi->pdev->dev, format, ## arg)
46
47#define tb_ctl_warn(ctl, format, arg...) \
48 dev_warn(&(ctl)->nhi->pdev->dev, format, ## arg)
49
50#define tb_ctl_info(ctl, format, arg...) \
51 dev_info(&(ctl)->nhi->pdev->dev, format, ## arg)
52
53#define tb_ctl_dbg(ctl, format, arg...) \
54 dev_dbg(&(ctl)->nhi->pdev->dev, format, ## arg)
55
56static DECLARE_WAIT_QUEUE_HEAD(tb_cfg_request_cancel_queue);
57/* Serializes access to request kref_get/put */
58static DEFINE_MUTEX(tb_cfg_request_lock);
59
60/**
61 * tb_cfg_request_alloc() - Allocates a new config request
62 *
63 * This is refcounted object so when you are done with this, call
64 * tb_cfg_request_put() to it.
65 */
66struct tb_cfg_request *tb_cfg_request_alloc(void)
67{
68 struct tb_cfg_request *req;
69
70 req = kzalloc(sizeof(*req), GFP_KERNEL);
71 if (!req)
72 return NULL;
73
74 kref_init(&req->kref);
75
76 return req;
77}
78
79/**
80 * tb_cfg_request_get() - Increase refcount of a request
81 * @req: Request whose refcount is increased
82 */
83void tb_cfg_request_get(struct tb_cfg_request *req)
84{
85 mutex_lock(&tb_cfg_request_lock);
86 kref_get(&req->kref);
87 mutex_unlock(&tb_cfg_request_lock);
88}
89
90static void tb_cfg_request_destroy(struct kref *kref)
91{
92 struct tb_cfg_request *req = container_of(kref, typeof(*req), kref);
93
94 kfree(req);
95}
96
97/**
98 * tb_cfg_request_put() - Decrease refcount and possibly release the request
99 * @req: Request whose refcount is decreased
100 *
101 * Call this function when you are done with the request. When refcount
102 * goes to %0 the object is released.
103 */
104void tb_cfg_request_put(struct tb_cfg_request *req)
105{
106 mutex_lock(&tb_cfg_request_lock);
107 kref_put(&req->kref, tb_cfg_request_destroy);
108 mutex_unlock(&tb_cfg_request_lock);
109}
110
111static int tb_cfg_request_enqueue(struct tb_ctl *ctl,
112 struct tb_cfg_request *req)
113{
114 WARN_ON(test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags));
115 WARN_ON(req->ctl);
116
117 mutex_lock(&ctl->request_queue_lock);
118 if (!ctl->running) {
119 mutex_unlock(&ctl->request_queue_lock);
120 return -ENOTCONN;
121 }
122 req->ctl = ctl;
123 list_add_tail(&req->list, &ctl->request_queue);
124 set_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);
125 mutex_unlock(&ctl->request_queue_lock);
126 return 0;
127}
128
129static void tb_cfg_request_dequeue(struct tb_cfg_request *req)
130{
131 struct tb_ctl *ctl = req->ctl;
132
133 mutex_lock(&ctl->request_queue_lock);
134 list_del(&req->list);
135 clear_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);
136 if (test_bit(TB_CFG_REQUEST_CANCELED, &req->flags))
137 wake_up(&tb_cfg_request_cancel_queue);
138 mutex_unlock(&ctl->request_queue_lock);
139}
140
141static bool tb_cfg_request_is_active(struct tb_cfg_request *req)
142{
143 return test_bit(TB_CFG_REQUEST_ACTIVE, &req->flags);
144}
145
146static struct tb_cfg_request *
147tb_cfg_request_find(struct tb_ctl *ctl, struct ctl_pkg *pkg)
148{
149 struct tb_cfg_request *req;
150 bool found = false;
151
152 mutex_lock(&pkg->ctl->request_queue_lock);
153 list_for_each_entry(req, &pkg->ctl->request_queue, list) {
154 tb_cfg_request_get(req);
155 if (req->match(req, pkg)) {
156 found = true;
157 break;
158 }
159 tb_cfg_request_put(req);
160 }
161 mutex_unlock(&pkg->ctl->request_queue_lock);
162
163 return found ? req : NULL;
164}
165
166/* utility functions */
167
168
169static int check_header(const struct ctl_pkg *pkg, u32 len,
170 enum tb_cfg_pkg_type type, u64 route)
171{
172 struct tb_cfg_header *header = pkg->buffer;
173
174 /* check frame, TODO: frame flags */
175 if (WARN(len != pkg->frame.size,
176 "wrong framesize (expected %#x, got %#x)\n",
177 len, pkg->frame.size))
178 return -EIO;
179 if (WARN(type != pkg->frame.eof, "wrong eof (expected %#x, got %#x)\n",
180 type, pkg->frame.eof))
181 return -EIO;
182 if (WARN(pkg->frame.sof, "wrong sof (expected 0x0, got %#x)\n",
183 pkg->frame.sof))
184 return -EIO;
185
186 /* check header */
187 if (WARN(header->unknown != 1 << 9,
188 "header->unknown is %#x\n", header->unknown))
189 return -EIO;
190 if (WARN(route != tb_cfg_get_route(header),
191 "wrong route (expected %llx, got %llx)",
192 route, tb_cfg_get_route(header)))
193 return -EIO;
194 return 0;
195}
196
197static int check_config_address(struct tb_cfg_address addr,
198 enum tb_cfg_space space, u32 offset,
199 u32 length)
200{
201 if (WARN(addr.zero, "addr.zero is %#x\n", addr.zero))
202 return -EIO;
203 if (WARN(space != addr.space, "wrong space (expected %x, got %x\n)",
204 space, addr.space))
205 return -EIO;
206 if (WARN(offset != addr.offset, "wrong offset (expected %x, got %x\n)",
207 offset, addr.offset))
208 return -EIO;
209 if (WARN(length != addr.length, "wrong space (expected %x, got %x\n)",
210 length, addr.length))
211 return -EIO;
212 /*
213 * We cannot check addr->port as it is set to the upstream port of the
214 * sender.
215 */
216 return 0;
217}
218
219static struct tb_cfg_result decode_error(const struct ctl_pkg *response)
220{
221 struct cfg_error_pkg *pkg = response->buffer;
222 struct tb_cfg_result res = { 0 };
223 res.response_route = tb_cfg_get_route(&pkg->header);
224 res.response_port = 0;
225 res.err = check_header(response, sizeof(*pkg), TB_CFG_PKG_ERROR,
226 tb_cfg_get_route(&pkg->header));
227 if (res.err)
228 return res;
229
230 WARN(pkg->zero1, "pkg->zero1 is %#x\n", pkg->zero1);
231 WARN(pkg->zero2, "pkg->zero1 is %#x\n", pkg->zero1);
232 WARN(pkg->zero3, "pkg->zero1 is %#x\n", pkg->zero1);
233 res.err = 1;
234 res.tb_error = pkg->error;
235 res.response_port = pkg->port;
236 return res;
237
238}
239
240static struct tb_cfg_result parse_header(const struct ctl_pkg *pkg, u32 len,
241 enum tb_cfg_pkg_type type, u64 route)
242{
243 struct tb_cfg_header *header = pkg->buffer;
244 struct tb_cfg_result res = { 0 };
245
246 if (pkg->frame.eof == TB_CFG_PKG_ERROR)
247 return decode_error(pkg);
248
249 res.response_port = 0; /* will be updated later for cfg_read/write */
250 res.response_route = tb_cfg_get_route(header);
251 res.err = check_header(pkg, len, type, route);
252 return res;
253}
254
255static void tb_cfg_print_error(struct tb_ctl *ctl,
256 const struct tb_cfg_result *res)
257{
258 WARN_ON(res->err != 1);
259 switch (res->tb_error) {
260 case TB_CFG_ERROR_PORT_NOT_CONNECTED:
261 /* Port is not connected. This can happen during surprise
262 * removal. Do not warn. */
263 return;
264 case TB_CFG_ERROR_INVALID_CONFIG_SPACE:
265 /*
266 * Invalid cfg_space/offset/length combination in
267 * cfg_read/cfg_write.
268 */
269 tb_ctl_WARN(ctl,
270 "CFG_ERROR(%llx:%x): Invalid config space or offset\n",
271 res->response_route, res->response_port);
272 return;
273 case TB_CFG_ERROR_NO_SUCH_PORT:
274 /*
275 * - The route contains a non-existent port.
276 * - The route contains a non-PHY port (e.g. PCIe).
277 * - The port in cfg_read/cfg_write does not exist.
278 */
279 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n",
280 res->response_route, res->response_port);
281 return;
282 case TB_CFG_ERROR_LOOP:
283 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n",
284 res->response_route, res->response_port);
285 return;
286 default:
287 /* 5,6,7,9 and 11 are also valid error codes */
288 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n",
289 res->response_route, res->response_port);
290 return;
291 }
292}
293
294static __be32 tb_crc(const void *data, size_t len)
295{
296 return cpu_to_be32(~__crc32c_le(~0, data, len));
297}
298
299static void tb_ctl_pkg_free(struct ctl_pkg *pkg)
300{
301 if (pkg) {
302 dma_pool_free(pkg->ctl->frame_pool,
303 pkg->buffer, pkg->frame.buffer_phy);
304 kfree(pkg);
305 }
306}
307
308static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl)
309{
310 struct ctl_pkg *pkg = kzalloc(sizeof(*pkg), GFP_KERNEL);
311 if (!pkg)
312 return NULL;
313 pkg->ctl = ctl;
314 pkg->buffer = dma_pool_alloc(ctl->frame_pool, GFP_KERNEL,
315 &pkg->frame.buffer_phy);
316 if (!pkg->buffer) {
317 kfree(pkg);
318 return NULL;
319 }
320 return pkg;
321}
322
323
324/* RX/TX handling */
325
326static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
327 bool canceled)
328{
329 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
330 tb_ctl_pkg_free(pkg);
331}
332
333/**
334 * tb_cfg_tx() - transmit a packet on the control channel
335 *
336 * len must be a multiple of four.
337 *
338 * Return: Returns 0 on success or an error code on failure.
339 */
340static int tb_ctl_tx(struct tb_ctl *ctl, const void *data, size_t len,
341 enum tb_cfg_pkg_type type)
342{
343 int res;
344 struct ctl_pkg *pkg;
345 if (len % 4 != 0) { /* required for le->be conversion */
346 tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len);
347 return -EINVAL;
348 }
349 if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */
350 tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n",
351 len, TB_FRAME_SIZE - 4);
352 return -EINVAL;
353 }
354 pkg = tb_ctl_pkg_alloc(ctl);
355 if (!pkg)
356 return -ENOMEM;
357 pkg->frame.callback = tb_ctl_tx_callback;
358 pkg->frame.size = len + 4;
359 pkg->frame.sof = type;
360 pkg->frame.eof = type;
361 cpu_to_be32_array(pkg->buffer, data, len / 4);
362 *(__be32 *) (pkg->buffer + len) = tb_crc(pkg->buffer, len);
363
364 res = tb_ring_tx(ctl->tx, &pkg->frame);
365 if (res) /* ring is stopped */
366 tb_ctl_pkg_free(pkg);
367 return res;
368}
369
370/**
371 * tb_ctl_handle_event() - acknowledge a plug event, invoke ctl->callback
372 */
373static bool tb_ctl_handle_event(struct tb_ctl *ctl, enum tb_cfg_pkg_type type,
374 struct ctl_pkg *pkg, size_t size)
375{
376 return ctl->callback(ctl->callback_data, type, pkg->buffer, size);
377}
378
379static void tb_ctl_rx_submit(struct ctl_pkg *pkg)
380{
381 tb_ring_rx(pkg->ctl->rx, &pkg->frame); /*
382 * We ignore failures during stop.
383 * All rx packets are referenced
384 * from ctl->rx_packets, so we do
385 * not loose them.
386 */
387}
388
389static int tb_async_error(const struct ctl_pkg *pkg)
390{
391 const struct cfg_error_pkg *error = (const struct cfg_error_pkg *)pkg;
392
393 if (pkg->frame.eof != TB_CFG_PKG_ERROR)
394 return false;
395
396 switch (error->error) {
397 case TB_CFG_ERROR_LINK_ERROR:
398 case TB_CFG_ERROR_HEC_ERROR_DETECTED:
399 case TB_CFG_ERROR_FLOW_CONTROL_ERROR:
400 return true;
401
402 default:
403 return false;
404 }
405}
406
407static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame,
408 bool canceled)
409{
410 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
411 struct tb_cfg_request *req;
412 __be32 crc32;
413
414 if (canceled)
415 return; /*
416 * ring is stopped, packet is referenced from
417 * ctl->rx_packets.
418 */
419
420 if (frame->size < 4 || frame->size % 4 != 0) {
421 tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n",
422 frame->size);
423 goto rx;
424 }
425
426 frame->size -= 4; /* remove checksum */
427 crc32 = tb_crc(pkg->buffer, frame->size);
428 be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4);
429
430 switch (frame->eof) {
431 case TB_CFG_PKG_READ:
432 case TB_CFG_PKG_WRITE:
433 case TB_CFG_PKG_ERROR:
434 case TB_CFG_PKG_OVERRIDE:
435 case TB_CFG_PKG_RESET:
436 if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {
437 tb_ctl_err(pkg->ctl,
438 "RX: checksum mismatch, dropping packet\n");
439 goto rx;
440 }
441 if (tb_async_error(pkg)) {
442 tb_ctl_handle_event(pkg->ctl, frame->eof,
443 pkg, frame->size);
444 goto rx;
445 }
446 break;
447
448 case TB_CFG_PKG_EVENT:
449 case TB_CFG_PKG_XDOMAIN_RESP:
450 case TB_CFG_PKG_XDOMAIN_REQ:
451 if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {
452 tb_ctl_err(pkg->ctl,
453 "RX: checksum mismatch, dropping packet\n");
454 goto rx;
455 }
456 /* Fall through */
457 case TB_CFG_PKG_ICM_EVENT:
458 if (tb_ctl_handle_event(pkg->ctl, frame->eof, pkg, frame->size))
459 goto rx;
460 break;
461
462 default:
463 break;
464 }
465
466 /*
467 * The received packet will be processed only if there is an
468 * active request and that the packet is what is expected. This
469 * prevents packets such as replies coming after timeout has
470 * triggered from messing with the active requests.
471 */
472 req = tb_cfg_request_find(pkg->ctl, pkg);
473 if (req) {
474 if (req->copy(req, pkg))
475 schedule_work(&req->work);
476 tb_cfg_request_put(req);
477 }
478
479rx:
480 tb_ctl_rx_submit(pkg);
481}
482
483static void tb_cfg_request_work(struct work_struct *work)
484{
485 struct tb_cfg_request *req = container_of(work, typeof(*req), work);
486
487 if (!test_bit(TB_CFG_REQUEST_CANCELED, &req->flags))
488 req->callback(req->callback_data);
489
490 tb_cfg_request_dequeue(req);
491 tb_cfg_request_put(req);
492}
493
494/**
495 * tb_cfg_request() - Start control request not waiting for it to complete
496 * @ctl: Control channel to use
497 * @req: Request to start
498 * @callback: Callback called when the request is completed
499 * @callback_data: Data to be passed to @callback
500 *
501 * This queues @req on the given control channel without waiting for it
502 * to complete. When the request completes @callback is called.
503 */
504int tb_cfg_request(struct tb_ctl *ctl, struct tb_cfg_request *req,
505 void (*callback)(void *), void *callback_data)
506{
507 int ret;
508
509 req->flags = 0;
510 req->callback = callback;
511 req->callback_data = callback_data;
512 INIT_WORK(&req->work, tb_cfg_request_work);
513 INIT_LIST_HEAD(&req->list);
514
515 tb_cfg_request_get(req);
516 ret = tb_cfg_request_enqueue(ctl, req);
517 if (ret)
518 goto err_put;
519
520 ret = tb_ctl_tx(ctl, req->request, req->request_size,
521 req->request_type);
522 if (ret)
523 goto err_dequeue;
524
525 if (!req->response)
526 schedule_work(&req->work);
527
528 return 0;
529
530err_dequeue:
531 tb_cfg_request_dequeue(req);
532err_put:
533 tb_cfg_request_put(req);
534
535 return ret;
536}
537
538/**
539 * tb_cfg_request_cancel() - Cancel a control request
540 * @req: Request to cancel
541 * @err: Error to assign to the request
542 *
543 * This function can be used to cancel ongoing request. It will wait
544 * until the request is not active anymore.
545 */
546void tb_cfg_request_cancel(struct tb_cfg_request *req, int err)
547{
548 set_bit(TB_CFG_REQUEST_CANCELED, &req->flags);
549 schedule_work(&req->work);
550 wait_event(tb_cfg_request_cancel_queue, !tb_cfg_request_is_active(req));
551 req->result.err = err;
552}
553
554static void tb_cfg_request_complete(void *data)
555{
556 complete(data);
557}
558
559/**
560 * tb_cfg_request_sync() - Start control request and wait until it completes
561 * @ctl: Control channel to use
562 * @req: Request to start
563 * @timeout_msec: Timeout how long to wait @req to complete
564 *
565 * Starts a control request and waits until it completes. If timeout
566 * triggers the request is canceled before function returns. Note the
567 * caller needs to make sure only one message for given switch is active
568 * at a time.
569 */
570struct tb_cfg_result tb_cfg_request_sync(struct tb_ctl *ctl,
571 struct tb_cfg_request *req,
572 int timeout_msec)
573{
574 unsigned long timeout = msecs_to_jiffies(timeout_msec);
575 struct tb_cfg_result res = { 0 };
576 DECLARE_COMPLETION_ONSTACK(done);
577 int ret;
578
579 ret = tb_cfg_request(ctl, req, tb_cfg_request_complete, &done);
580 if (ret) {
581 res.err = ret;
582 return res;
583 }
584
585 if (!wait_for_completion_timeout(&done, timeout))
586 tb_cfg_request_cancel(req, -ETIMEDOUT);
587
588 flush_work(&req->work);
589
590 return req->result;
591}
592
593/* public interface, alloc/start/stop/free */
594
595/**
596 * tb_ctl_alloc() - allocate a control channel
597 *
598 * cb will be invoked once for every hot plug event.
599 *
600 * Return: Returns a pointer on success or NULL on failure.
601 */
602struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, event_cb cb, void *cb_data)
603{
604 int i;
605 struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
606 if (!ctl)
607 return NULL;
608 ctl->nhi = nhi;
609 ctl->callback = cb;
610 ctl->callback_data = cb_data;
611
612 mutex_init(&ctl->request_queue_lock);
613 INIT_LIST_HEAD(&ctl->request_queue);
614 ctl->frame_pool = dma_pool_create("thunderbolt_ctl", &nhi->pdev->dev,
615 TB_FRAME_SIZE, 4, 0);
616 if (!ctl->frame_pool)
617 goto err;
618
619 ctl->tx = tb_ring_alloc_tx(nhi, 0, 10, RING_FLAG_NO_SUSPEND);
620 if (!ctl->tx)
621 goto err;
622
623 ctl->rx = tb_ring_alloc_rx(nhi, 0, 10, RING_FLAG_NO_SUSPEND, 0xffff,
624 0xffff, NULL, NULL);
625 if (!ctl->rx)
626 goto err;
627
628 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) {
629 ctl->rx_packets[i] = tb_ctl_pkg_alloc(ctl);
630 if (!ctl->rx_packets[i])
631 goto err;
632 ctl->rx_packets[i]->frame.callback = tb_ctl_rx_callback;
633 }
634
635 tb_ctl_dbg(ctl, "control channel created\n");
636 return ctl;
637err:
638 tb_ctl_free(ctl);
639 return NULL;
640}
641
642/**
643 * tb_ctl_free() - free a control channel
644 *
645 * Must be called after tb_ctl_stop.
646 *
647 * Must NOT be called from ctl->callback.
648 */
649void tb_ctl_free(struct tb_ctl *ctl)
650{
651 int i;
652
653 if (!ctl)
654 return;
655
656 if (ctl->rx)
657 tb_ring_free(ctl->rx);
658 if (ctl->tx)
659 tb_ring_free(ctl->tx);
660
661 /* free RX packets */
662 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
663 tb_ctl_pkg_free(ctl->rx_packets[i]);
664
665
666 dma_pool_destroy(ctl->frame_pool);
667 kfree(ctl);
668}
669
670/**
671 * tb_cfg_start() - start/resume the control channel
672 */
673void tb_ctl_start(struct tb_ctl *ctl)
674{
675 int i;
676 tb_ctl_dbg(ctl, "control channel starting...\n");
677 tb_ring_start(ctl->tx); /* is used to ack hotplug packets, start first */
678 tb_ring_start(ctl->rx);
679 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
680 tb_ctl_rx_submit(ctl->rx_packets[i]);
681
682 ctl->running = true;
683}
684
685/**
686 * control() - pause the control channel
687 *
688 * All invocations of ctl->callback will have finished after this method
689 * returns.
690 *
691 * Must NOT be called from ctl->callback.
692 */
693void tb_ctl_stop(struct tb_ctl *ctl)
694{
695 mutex_lock(&ctl->request_queue_lock);
696 ctl->running = false;
697 mutex_unlock(&ctl->request_queue_lock);
698
699 tb_ring_stop(ctl->rx);
700 tb_ring_stop(ctl->tx);
701
702 if (!list_empty(&ctl->request_queue))
703 tb_ctl_WARN(ctl, "dangling request in request_queue\n");
704 INIT_LIST_HEAD(&ctl->request_queue);
705 tb_ctl_dbg(ctl, "control channel stopped\n");
706}
707
708/* public interface, commands */
709
710/**
711 * tb_cfg_error() - send error packet
712 *
713 * Return: Returns 0 on success or an error code on failure.
714 */
715int tb_cfg_error(struct tb_ctl *ctl, u64 route, u32 port,
716 enum tb_cfg_error error)
717{
718 struct cfg_error_pkg pkg = {
719 .header = tb_cfg_make_header(route),
720 .port = port,
721 .error = error,
722 };
723 tb_ctl_dbg(ctl, "resetting error on %llx:%x.\n", route, port);
724 return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR);
725}
726
727static bool tb_cfg_match(const struct tb_cfg_request *req,
728 const struct ctl_pkg *pkg)
729{
730 u64 route = tb_cfg_get_route(pkg->buffer) & ~BIT_ULL(63);
731
732 if (pkg->frame.eof == TB_CFG_PKG_ERROR)
733 return true;
734
735 if (pkg->frame.eof != req->response_type)
736 return false;
737 if (route != tb_cfg_get_route(req->request))
738 return false;
739 if (pkg->frame.size != req->response_size)
740 return false;
741
742 if (pkg->frame.eof == TB_CFG_PKG_READ ||
743 pkg->frame.eof == TB_CFG_PKG_WRITE) {
744 const struct cfg_read_pkg *req_hdr = req->request;
745 const struct cfg_read_pkg *res_hdr = pkg->buffer;
746
747 if (req_hdr->addr.seq != res_hdr->addr.seq)
748 return false;
749 }
750
751 return true;
752}
753
754static bool tb_cfg_copy(struct tb_cfg_request *req, const struct ctl_pkg *pkg)
755{
756 struct tb_cfg_result res;
757
758 /* Now make sure it is in expected format */
759 res = parse_header(pkg, req->response_size, req->response_type,
760 tb_cfg_get_route(req->request));
761 if (!res.err)
762 memcpy(req->response, pkg->buffer, req->response_size);
763
764 req->result = res;
765
766 /* Always complete when first response is received */
767 return true;
768}
769
770/**
771 * tb_cfg_reset() - send a reset packet and wait for a response
772 *
773 * If the switch at route is incorrectly configured then we will not receive a
774 * reply (even though the switch will reset). The caller should check for
775 * -ETIMEDOUT and attempt to reconfigure the switch.
776 */
777struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route,
778 int timeout_msec)
779{
780 struct cfg_reset_pkg request = { .header = tb_cfg_make_header(route) };
781 struct tb_cfg_result res = { 0 };
782 struct tb_cfg_header reply;
783 struct tb_cfg_request *req;
784
785 req = tb_cfg_request_alloc();
786 if (!req) {
787 res.err = -ENOMEM;
788 return res;
789 }
790
791 req->match = tb_cfg_match;
792 req->copy = tb_cfg_copy;
793 req->request = &request;
794 req->request_size = sizeof(request);
795 req->request_type = TB_CFG_PKG_RESET;
796 req->response = &reply;
797 req->response_size = sizeof(reply);
798 req->response_type = TB_CFG_PKG_RESET;
799
800 res = tb_cfg_request_sync(ctl, req, timeout_msec);
801
802 tb_cfg_request_put(req);
803
804 return res;
805}
806
807/**
808 * tb_cfg_read() - read from config space into buffer
809 *
810 * Offset and length are in dwords.
811 */
812struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer,
813 u64 route, u32 port, enum tb_cfg_space space,
814 u32 offset, u32 length, int timeout_msec)
815{
816 struct tb_cfg_result res = { 0 };
817 struct cfg_read_pkg request = {
818 .header = tb_cfg_make_header(route),
819 .addr = {
820 .port = port,
821 .space = space,
822 .offset = offset,
823 .length = length,
824 },
825 };
826 struct cfg_write_pkg reply;
827 int retries = 0;
828
829 while (retries < TB_CTL_RETRIES) {
830 struct tb_cfg_request *req;
831
832 req = tb_cfg_request_alloc();
833 if (!req) {
834 res.err = -ENOMEM;
835 return res;
836 }
837
838 request.addr.seq = retries++;
839
840 req->match = tb_cfg_match;
841 req->copy = tb_cfg_copy;
842 req->request = &request;
843 req->request_size = sizeof(request);
844 req->request_type = TB_CFG_PKG_READ;
845 req->response = &reply;
846 req->response_size = 12 + 4 * length;
847 req->response_type = TB_CFG_PKG_READ;
848
849 res = tb_cfg_request_sync(ctl, req, timeout_msec);
850
851 tb_cfg_request_put(req);
852
853 if (res.err != -ETIMEDOUT)
854 break;
855
856 /* Wait a bit (arbitrary time) until we send a retry */
857 usleep_range(10, 100);
858 }
859
860 if (res.err)
861 return res;
862
863 res.response_port = reply.addr.port;
864 res.err = check_config_address(reply.addr, space, offset, length);
865 if (!res.err)
866 memcpy(buffer, &reply.data, 4 * length);
867 return res;
868}
869
870/**
871 * tb_cfg_write() - write from buffer into config space
872 *
873 * Offset and length are in dwords.
874 */
875struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, const void *buffer,
876 u64 route, u32 port, enum tb_cfg_space space,
877 u32 offset, u32 length, int timeout_msec)
878{
879 struct tb_cfg_result res = { 0 };
880 struct cfg_write_pkg request = {
881 .header = tb_cfg_make_header(route),
882 .addr = {
883 .port = port,
884 .space = space,
885 .offset = offset,
886 .length = length,
887 },
888 };
889 struct cfg_read_pkg reply;
890 int retries = 0;
891
892 memcpy(&request.data, buffer, length * 4);
893
894 while (retries < TB_CTL_RETRIES) {
895 struct tb_cfg_request *req;
896
897 req = tb_cfg_request_alloc();
898 if (!req) {
899 res.err = -ENOMEM;
900 return res;
901 }
902
903 request.addr.seq = retries++;
904
905 req->match = tb_cfg_match;
906 req->copy = tb_cfg_copy;
907 req->request = &request;
908 req->request_size = 12 + 4 * length;
909 req->request_type = TB_CFG_PKG_WRITE;
910 req->response = &reply;
911 req->response_size = sizeof(reply);
912 req->response_type = TB_CFG_PKG_WRITE;
913
914 res = tb_cfg_request_sync(ctl, req, timeout_msec);
915
916 tb_cfg_request_put(req);
917
918 if (res.err != -ETIMEDOUT)
919 break;
920
921 /* Wait a bit (arbitrary time) until we send a retry */
922 usleep_range(10, 100);
923 }
924
925 if (res.err)
926 return res;
927
928 res.response_port = reply.addr.port;
929 res.err = check_config_address(reply.addr, space, offset, length);
930 return res;
931}
932
933static int tb_cfg_get_error(struct tb_ctl *ctl, enum tb_cfg_space space,
934 const struct tb_cfg_result *res)
935{
936 /*
937 * For unimplemented ports access to port config space may return
938 * TB_CFG_ERROR_INVALID_CONFIG_SPACE (alternatively their type is
939 * set to TB_TYPE_INACTIVE). In the former case return -ENODEV so
940 * that the caller can mark the port as disabled.
941 */
942 if (space == TB_CFG_PORT &&
943 res->tb_error == TB_CFG_ERROR_INVALID_CONFIG_SPACE)
944 return -ENODEV;
945
946 tb_cfg_print_error(ctl, res);
947 return -EIO;
948}
949
950int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,
951 enum tb_cfg_space space, u32 offset, u32 length)
952{
953 struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port,
954 space, offset, length, TB_CFG_DEFAULT_TIMEOUT);
955 switch (res.err) {
956 case 0:
957 /* Success */
958 break;
959
960 case 1:
961 /* Thunderbolt error, tb_error holds the actual number */
962 return tb_cfg_get_error(ctl, space, &res);
963
964 case -ETIMEDOUT:
965 tb_ctl_warn(ctl, "timeout reading config space %u from %#x\n",
966 space, offset);
967 break;
968
969 default:
970 WARN(1, "tb_cfg_read: %d\n", res.err);
971 break;
972 }
973 return res.err;
974}
975
976int tb_cfg_write(struct tb_ctl *ctl, const void *buffer, u64 route, u32 port,
977 enum tb_cfg_space space, u32 offset, u32 length)
978{
979 struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port,
980 space, offset, length, TB_CFG_DEFAULT_TIMEOUT);
981 switch (res.err) {
982 case 0:
983 /* Success */
984 break;
985
986 case 1:
987 /* Thunderbolt error, tb_error holds the actual number */
988 return tb_cfg_get_error(ctl, space, &res);
989
990 case -ETIMEDOUT:
991 tb_ctl_warn(ctl, "timeout writing config space %u to %#x\n",
992 space, offset);
993 break;
994
995 default:
996 WARN(1, "tb_cfg_write: %d\n", res.err);
997 break;
998 }
999 return res.err;
1000}
1001
1002/**
1003 * tb_cfg_get_upstream_port() - get upstream port number of switch at route
1004 *
1005 * Reads the first dword from the switches TB_CFG_SWITCH config area and
1006 * returns the port number from which the reply originated.
1007 *
1008 * Return: Returns the upstream port number on success or an error code on
1009 * failure.
1010 */
1011int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route)
1012{
1013 u32 dummy;
1014 struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0,
1015 TB_CFG_SWITCH, 0, 1,
1016 TB_CFG_DEFAULT_TIMEOUT);
1017 if (res.err == 1)
1018 return -EIO;
1019 if (res.err)
1020 return res.err;
1021 return res.response_port;
1022}
1/*
2 * Thunderbolt Cactus Ridge driver - control channel and configuration commands
3 *
4 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com>
5 */
6
7#include <linux/crc32.h>
8#include <linux/slab.h>
9#include <linux/pci.h>
10#include <linux/dmapool.h>
11#include <linux/workqueue.h>
12#include <linux/kfifo.h>
13
14#include "ctl.h"
15
16
17struct ctl_pkg {
18 struct tb_ctl *ctl;
19 void *buffer;
20 struct ring_frame frame;
21};
22
23#define TB_CTL_RX_PKG_COUNT 10
24
25/**
26 * struct tb_cfg - thunderbolt control channel
27 */
28struct tb_ctl {
29 struct tb_nhi *nhi;
30 struct tb_ring *tx;
31 struct tb_ring *rx;
32
33 struct dma_pool *frame_pool;
34 struct ctl_pkg *rx_packets[TB_CTL_RX_PKG_COUNT];
35 DECLARE_KFIFO(response_fifo, struct ctl_pkg*, 16);
36 struct completion response_ready;
37
38 hotplug_cb callback;
39 void *callback_data;
40};
41
42
43#define tb_ctl_WARN(ctl, format, arg...) \
44 dev_WARN(&(ctl)->nhi->pdev->dev, format, ## arg)
45
46#define tb_ctl_err(ctl, format, arg...) \
47 dev_err(&(ctl)->nhi->pdev->dev, format, ## arg)
48
49#define tb_ctl_warn(ctl, format, arg...) \
50 dev_warn(&(ctl)->nhi->pdev->dev, format, ## arg)
51
52#define tb_ctl_info(ctl, format, arg...) \
53 dev_info(&(ctl)->nhi->pdev->dev, format, ## arg)
54
55
56/* configuration packets definitions */
57
58enum tb_cfg_pkg_type {
59 TB_CFG_PKG_READ = 1,
60 TB_CFG_PKG_WRITE = 2,
61 TB_CFG_PKG_ERROR = 3,
62 TB_CFG_PKG_NOTIFY_ACK = 4,
63 TB_CFG_PKG_EVENT = 5,
64 TB_CFG_PKG_XDOMAIN_REQ = 6,
65 TB_CFG_PKG_XDOMAIN_RESP = 7,
66 TB_CFG_PKG_OVERRIDE = 8,
67 TB_CFG_PKG_RESET = 9,
68 TB_CFG_PKG_PREPARE_TO_SLEEP = 0xd,
69};
70
71/* common header */
72struct tb_cfg_header {
73 u32 route_hi:22;
74 u32 unknown:10; /* highest order bit is set on replies */
75 u32 route_lo;
76} __packed;
77
78/* additional header for read/write packets */
79struct tb_cfg_address {
80 u32 offset:13; /* in dwords */
81 u32 length:6; /* in dwords */
82 u32 port:6;
83 enum tb_cfg_space space:2;
84 u32 seq:2; /* sequence number */
85 u32 zero:3;
86} __packed;
87
88/* TB_CFG_PKG_READ, response for TB_CFG_PKG_WRITE */
89struct cfg_read_pkg {
90 struct tb_cfg_header header;
91 struct tb_cfg_address addr;
92} __packed;
93
94/* TB_CFG_PKG_WRITE, response for TB_CFG_PKG_READ */
95struct cfg_write_pkg {
96 struct tb_cfg_header header;
97 struct tb_cfg_address addr;
98 u32 data[64]; /* maximum size, tb_cfg_address.length has 6 bits */
99} __packed;
100
101/* TB_CFG_PKG_ERROR */
102struct cfg_error_pkg {
103 struct tb_cfg_header header;
104 enum tb_cfg_error error:4;
105 u32 zero1:4;
106 u32 port:6;
107 u32 zero2:2; /* Both should be zero, still they are different fields. */
108 u32 zero3:16;
109} __packed;
110
111/* TB_CFG_PKG_EVENT */
112struct cfg_event_pkg {
113 struct tb_cfg_header header;
114 u32 port:6;
115 u32 zero:25;
116 bool unplug:1;
117} __packed;
118
119/* TB_CFG_PKG_RESET */
120struct cfg_reset_pkg {
121 struct tb_cfg_header header;
122} __packed;
123
124/* TB_CFG_PKG_PREPARE_TO_SLEEP */
125struct cfg_pts_pkg {
126 struct tb_cfg_header header;
127 u32 data;
128} __packed;
129
130
131/* utility functions */
132
133static u64 get_route(struct tb_cfg_header header)
134{
135 return (u64) header.route_hi << 32 | header.route_lo;
136}
137
138static struct tb_cfg_header make_header(u64 route)
139{
140 struct tb_cfg_header header = {
141 .route_hi = route >> 32,
142 .route_lo = route,
143 };
144 /* check for overflow, route_hi is not 32 bits! */
145 WARN_ON(get_route(header) != route);
146 return header;
147}
148
149static int check_header(struct ctl_pkg *pkg, u32 len, enum tb_cfg_pkg_type type,
150 u64 route)
151{
152 struct tb_cfg_header *header = pkg->buffer;
153
154 /* check frame, TODO: frame flags */
155 if (WARN(len != pkg->frame.size,
156 "wrong framesize (expected %#x, got %#x)\n",
157 len, pkg->frame.size))
158 return -EIO;
159 if (WARN(type != pkg->frame.eof, "wrong eof (expected %#x, got %#x)\n",
160 type, pkg->frame.eof))
161 return -EIO;
162 if (WARN(pkg->frame.sof, "wrong sof (expected 0x0, got %#x)\n",
163 pkg->frame.sof))
164 return -EIO;
165
166 /* check header */
167 if (WARN(header->unknown != 1 << 9,
168 "header->unknown is %#x\n", header->unknown))
169 return -EIO;
170 if (WARN(route != get_route(*header),
171 "wrong route (expected %llx, got %llx)",
172 route, get_route(*header)))
173 return -EIO;
174 return 0;
175}
176
177static int check_config_address(struct tb_cfg_address addr,
178 enum tb_cfg_space space, u32 offset,
179 u32 length)
180{
181 if (WARN(addr.zero, "addr.zero is %#x\n", addr.zero))
182 return -EIO;
183 if (WARN(space != addr.space, "wrong space (expected %x, got %x\n)",
184 space, addr.space))
185 return -EIO;
186 if (WARN(offset != addr.offset, "wrong offset (expected %x, got %x\n)",
187 offset, addr.offset))
188 return -EIO;
189 if (WARN(length != addr.length, "wrong space (expected %x, got %x\n)",
190 length, addr.length))
191 return -EIO;
192 if (WARN(addr.seq, "addr.seq is %#x\n", addr.seq))
193 return -EIO;
194 /*
195 * We cannot check addr->port as it is set to the upstream port of the
196 * sender.
197 */
198 return 0;
199}
200
201static struct tb_cfg_result decode_error(struct ctl_pkg *response)
202{
203 struct cfg_error_pkg *pkg = response->buffer;
204 struct tb_cfg_result res = { 0 };
205 res.response_route = get_route(pkg->header);
206 res.response_port = 0;
207 res.err = check_header(response, sizeof(*pkg), TB_CFG_PKG_ERROR,
208 get_route(pkg->header));
209 if (res.err)
210 return res;
211
212 WARN(pkg->zero1, "pkg->zero1 is %#x\n", pkg->zero1);
213 WARN(pkg->zero2, "pkg->zero1 is %#x\n", pkg->zero1);
214 WARN(pkg->zero3, "pkg->zero1 is %#x\n", pkg->zero1);
215 res.err = 1;
216 res.tb_error = pkg->error;
217 res.response_port = pkg->port;
218 return res;
219
220}
221
222static struct tb_cfg_result parse_header(struct ctl_pkg *pkg, u32 len,
223 enum tb_cfg_pkg_type type, u64 route)
224{
225 struct tb_cfg_header *header = pkg->buffer;
226 struct tb_cfg_result res = { 0 };
227
228 if (pkg->frame.eof == TB_CFG_PKG_ERROR)
229 return decode_error(pkg);
230
231 res.response_port = 0; /* will be updated later for cfg_read/write */
232 res.response_route = get_route(*header);
233 res.err = check_header(pkg, len, type, route);
234 return res;
235}
236
237static void tb_cfg_print_error(struct tb_ctl *ctl,
238 const struct tb_cfg_result *res)
239{
240 WARN_ON(res->err != 1);
241 switch (res->tb_error) {
242 case TB_CFG_ERROR_PORT_NOT_CONNECTED:
243 /* Port is not connected. This can happen during surprise
244 * removal. Do not warn. */
245 return;
246 case TB_CFG_ERROR_INVALID_CONFIG_SPACE:
247 /*
248 * Invalid cfg_space/offset/length combination in
249 * cfg_read/cfg_write.
250 */
251 tb_ctl_WARN(ctl,
252 "CFG_ERROR(%llx:%x): Invalid config space or offset\n",
253 res->response_route, res->response_port);
254 return;
255 case TB_CFG_ERROR_NO_SUCH_PORT:
256 /*
257 * - The route contains a non-existent port.
258 * - The route contains a non-PHY port (e.g. PCIe).
259 * - The port in cfg_read/cfg_write does not exist.
260 */
261 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n",
262 res->response_route, res->response_port);
263 return;
264 case TB_CFG_ERROR_LOOP:
265 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n",
266 res->response_route, res->response_port);
267 return;
268 default:
269 /* 5,6,7,9 and 11 are also valid error codes */
270 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n",
271 res->response_route, res->response_port);
272 return;
273 }
274}
275
276static void cpu_to_be32_array(__be32 *dst, u32 *src, size_t len)
277{
278 int i;
279 for (i = 0; i < len; i++)
280 dst[i] = cpu_to_be32(src[i]);
281}
282
283static void be32_to_cpu_array(u32 *dst, __be32 *src, size_t len)
284{
285 int i;
286 for (i = 0; i < len; i++)
287 dst[i] = be32_to_cpu(src[i]);
288}
289
290static __be32 tb_crc(void *data, size_t len)
291{
292 return cpu_to_be32(~__crc32c_le(~0, data, len));
293}
294
295static void tb_ctl_pkg_free(struct ctl_pkg *pkg)
296{
297 if (pkg) {
298 dma_pool_free(pkg->ctl->frame_pool,
299 pkg->buffer, pkg->frame.buffer_phy);
300 kfree(pkg);
301 }
302}
303
304static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl)
305{
306 struct ctl_pkg *pkg = kzalloc(sizeof(*pkg), GFP_KERNEL);
307 if (!pkg)
308 return NULL;
309 pkg->ctl = ctl;
310 pkg->buffer = dma_pool_alloc(ctl->frame_pool, GFP_KERNEL,
311 &pkg->frame.buffer_phy);
312 if (!pkg->buffer) {
313 kfree(pkg);
314 return NULL;
315 }
316 return pkg;
317}
318
319
320/* RX/TX handling */
321
322static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
323 bool canceled)
324{
325 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
326 tb_ctl_pkg_free(pkg);
327}
328
329/**
330 * tb_cfg_tx() - transmit a packet on the control channel
331 *
332 * len must be a multiple of four.
333 *
334 * Return: Returns 0 on success or an error code on failure.
335 */
336static int tb_ctl_tx(struct tb_ctl *ctl, void *data, size_t len,
337 enum tb_cfg_pkg_type type)
338{
339 int res;
340 struct ctl_pkg *pkg;
341 if (len % 4 != 0) { /* required for le->be conversion */
342 tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len);
343 return -EINVAL;
344 }
345 if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */
346 tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n",
347 len, TB_FRAME_SIZE - 4);
348 return -EINVAL;
349 }
350 pkg = tb_ctl_pkg_alloc(ctl);
351 if (!pkg)
352 return -ENOMEM;
353 pkg->frame.callback = tb_ctl_tx_callback;
354 pkg->frame.size = len + 4;
355 pkg->frame.sof = type;
356 pkg->frame.eof = type;
357 cpu_to_be32_array(pkg->buffer, data, len / 4);
358 *(__be32 *) (pkg->buffer + len) = tb_crc(pkg->buffer, len);
359
360 res = ring_tx(ctl->tx, &pkg->frame);
361 if (res) /* ring is stopped */
362 tb_ctl_pkg_free(pkg);
363 return res;
364}
365
366/**
367 * tb_ctl_handle_plug_event() - acknowledge a plug event, invoke ctl->callback
368 */
369static void tb_ctl_handle_plug_event(struct tb_ctl *ctl,
370 struct ctl_pkg *response)
371{
372 struct cfg_event_pkg *pkg = response->buffer;
373 u64 route = get_route(pkg->header);
374
375 if (check_header(response, sizeof(*pkg), TB_CFG_PKG_EVENT, route)) {
376 tb_ctl_warn(ctl, "malformed TB_CFG_PKG_EVENT\n");
377 return;
378 }
379
380 if (tb_cfg_error(ctl, route, pkg->port, TB_CFG_ERROR_ACK_PLUG_EVENT))
381 tb_ctl_warn(ctl, "could not ack plug event on %llx:%x\n",
382 route, pkg->port);
383 WARN(pkg->zero, "pkg->zero is %#x\n", pkg->zero);
384 ctl->callback(ctl->callback_data, route, pkg->port, pkg->unplug);
385}
386
387static void tb_ctl_rx_submit(struct ctl_pkg *pkg)
388{
389 ring_rx(pkg->ctl->rx, &pkg->frame); /*
390 * We ignore failures during stop.
391 * All rx packets are referenced
392 * from ctl->rx_packets, so we do
393 * not loose them.
394 */
395}
396
397static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame,
398 bool canceled)
399{
400 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
401
402 if (canceled)
403 return; /*
404 * ring is stopped, packet is referenced from
405 * ctl->rx_packets.
406 */
407
408 if (frame->size < 4 || frame->size % 4 != 0) {
409 tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n",
410 frame->size);
411 goto rx;
412 }
413
414 frame->size -= 4; /* remove checksum */
415 if (*(__be32 *) (pkg->buffer + frame->size)
416 != tb_crc(pkg->buffer, frame->size)) {
417 tb_ctl_err(pkg->ctl,
418 "RX: checksum mismatch, dropping packet\n");
419 goto rx;
420 }
421 be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4);
422
423 if (frame->eof == TB_CFG_PKG_EVENT) {
424 tb_ctl_handle_plug_event(pkg->ctl, pkg);
425 goto rx;
426 }
427 if (!kfifo_put(&pkg->ctl->response_fifo, pkg)) {
428 tb_ctl_err(pkg->ctl, "RX: fifo is full\n");
429 goto rx;
430 }
431 complete(&pkg->ctl->response_ready);
432 return;
433rx:
434 tb_ctl_rx_submit(pkg);
435}
436
437/**
438 * tb_ctl_rx() - receive a packet from the control channel
439 */
440static struct tb_cfg_result tb_ctl_rx(struct tb_ctl *ctl, void *buffer,
441 size_t length, int timeout_msec,
442 u64 route, enum tb_cfg_pkg_type type)
443{
444 struct tb_cfg_result res;
445 struct ctl_pkg *pkg;
446
447 if (!wait_for_completion_timeout(&ctl->response_ready,
448 msecs_to_jiffies(timeout_msec))) {
449 tb_ctl_WARN(ctl, "RX: timeout\n");
450 return (struct tb_cfg_result) { .err = -ETIMEDOUT };
451 }
452 if (!kfifo_get(&ctl->response_fifo, &pkg)) {
453 tb_ctl_WARN(ctl, "empty kfifo\n");
454 return (struct tb_cfg_result) { .err = -EIO };
455 }
456
457 res = parse_header(pkg, length, type, route);
458 if (!res.err)
459 memcpy(buffer, pkg->buffer, length);
460 tb_ctl_rx_submit(pkg);
461 return res;
462}
463
464
465/* public interface, alloc/start/stop/free */
466
467/**
468 * tb_ctl_alloc() - allocate a control channel
469 *
470 * cb will be invoked once for every hot plug event.
471 *
472 * Return: Returns a pointer on success or NULL on failure.
473 */
474struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, hotplug_cb cb, void *cb_data)
475{
476 int i;
477 struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
478 if (!ctl)
479 return NULL;
480 ctl->nhi = nhi;
481 ctl->callback = cb;
482 ctl->callback_data = cb_data;
483
484 init_completion(&ctl->response_ready);
485 INIT_KFIFO(ctl->response_fifo);
486 ctl->frame_pool = dma_pool_create("thunderbolt_ctl", &nhi->pdev->dev,
487 TB_FRAME_SIZE, 4, 0);
488 if (!ctl->frame_pool)
489 goto err;
490
491 ctl->tx = ring_alloc_tx(nhi, 0, 10);
492 if (!ctl->tx)
493 goto err;
494
495 ctl->rx = ring_alloc_rx(nhi, 0, 10);
496 if (!ctl->rx)
497 goto err;
498
499 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) {
500 ctl->rx_packets[i] = tb_ctl_pkg_alloc(ctl);
501 if (!ctl->rx_packets[i])
502 goto err;
503 ctl->rx_packets[i]->frame.callback = tb_ctl_rx_callback;
504 }
505
506 tb_ctl_info(ctl, "control channel created\n");
507 return ctl;
508err:
509 tb_ctl_free(ctl);
510 return NULL;
511}
512
513/**
514 * tb_ctl_free() - free a control channel
515 *
516 * Must be called after tb_ctl_stop.
517 *
518 * Must NOT be called from ctl->callback.
519 */
520void tb_ctl_free(struct tb_ctl *ctl)
521{
522 int i;
523 if (ctl->rx)
524 ring_free(ctl->rx);
525 if (ctl->tx)
526 ring_free(ctl->tx);
527
528 /* free RX packets */
529 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
530 tb_ctl_pkg_free(ctl->rx_packets[i]);
531
532
533 if (ctl->frame_pool)
534 dma_pool_destroy(ctl->frame_pool);
535 kfree(ctl);
536}
537
538/**
539 * tb_cfg_start() - start/resume the control channel
540 */
541void tb_ctl_start(struct tb_ctl *ctl)
542{
543 int i;
544 tb_ctl_info(ctl, "control channel starting...\n");
545 ring_start(ctl->tx); /* is used to ack hotplug packets, start first */
546 ring_start(ctl->rx);
547 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
548 tb_ctl_rx_submit(ctl->rx_packets[i]);
549}
550
551/**
552 * control() - pause the control channel
553 *
554 * All invocations of ctl->callback will have finished after this method
555 * returns.
556 *
557 * Must NOT be called from ctl->callback.
558 */
559void tb_ctl_stop(struct tb_ctl *ctl)
560{
561 ring_stop(ctl->rx);
562 ring_stop(ctl->tx);
563
564 if (!kfifo_is_empty(&ctl->response_fifo))
565 tb_ctl_WARN(ctl, "dangling response in response_fifo\n");
566 kfifo_reset(&ctl->response_fifo);
567 tb_ctl_info(ctl, "control channel stopped\n");
568}
569
570/* public interface, commands */
571
572/**
573 * tb_cfg_error() - send error packet
574 *
575 * Return: Returns 0 on success or an error code on failure.
576 */
577int tb_cfg_error(struct tb_ctl *ctl, u64 route, u32 port,
578 enum tb_cfg_error error)
579{
580 struct cfg_error_pkg pkg = {
581 .header = make_header(route),
582 .port = port,
583 .error = error,
584 };
585 tb_ctl_info(ctl, "resetting error on %llx:%x.\n", route, port);
586 return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR);
587}
588
589/**
590 * tb_cfg_reset() - send a reset packet and wait for a response
591 *
592 * If the switch at route is incorrectly configured then we will not receive a
593 * reply (even though the switch will reset). The caller should check for
594 * -ETIMEDOUT and attempt to reconfigure the switch.
595 */
596struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route,
597 int timeout_msec)
598{
599 int err;
600 struct cfg_reset_pkg request = { .header = make_header(route) };
601 struct tb_cfg_header reply;
602
603 err = tb_ctl_tx(ctl, &request, sizeof(request), TB_CFG_PKG_RESET);
604 if (err)
605 return (struct tb_cfg_result) { .err = err };
606
607 return tb_ctl_rx(ctl, &reply, sizeof(reply), timeout_msec, route,
608 TB_CFG_PKG_RESET);
609}
610
611/**
612 * tb_cfg_read() - read from config space into buffer
613 *
614 * Offset and length are in dwords.
615 */
616struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer,
617 u64 route, u32 port, enum tb_cfg_space space,
618 u32 offset, u32 length, int timeout_msec)
619{
620 struct tb_cfg_result res = { 0 };
621 struct cfg_read_pkg request = {
622 .header = make_header(route),
623 .addr = {
624 .port = port,
625 .space = space,
626 .offset = offset,
627 .length = length,
628 },
629 };
630 struct cfg_write_pkg reply;
631
632 res.err = tb_ctl_tx(ctl, &request, sizeof(request), TB_CFG_PKG_READ);
633 if (res.err)
634 return res;
635
636 res = tb_ctl_rx(ctl, &reply, 12 + 4 * length, timeout_msec, route,
637 TB_CFG_PKG_READ);
638 if (res.err)
639 return res;
640
641 res.response_port = reply.addr.port;
642 res.err = check_config_address(reply.addr, space, offset, length);
643 if (!res.err)
644 memcpy(buffer, &reply.data, 4 * length);
645 return res;
646}
647
648/**
649 * tb_cfg_write() - write from buffer into config space
650 *
651 * Offset and length are in dwords.
652 */
653struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, void *buffer,
654 u64 route, u32 port, enum tb_cfg_space space,
655 u32 offset, u32 length, int timeout_msec)
656{
657 struct tb_cfg_result res = { 0 };
658 struct cfg_write_pkg request = {
659 .header = make_header(route),
660 .addr = {
661 .port = port,
662 .space = space,
663 .offset = offset,
664 .length = length,
665 },
666 };
667 struct cfg_read_pkg reply;
668
669 memcpy(&request.data, buffer, length * 4);
670
671 res.err = tb_ctl_tx(ctl, &request, 12 + 4 * length, TB_CFG_PKG_WRITE);
672 if (res.err)
673 return res;
674
675 res = tb_ctl_rx(ctl, &reply, sizeof(reply), timeout_msec, route,
676 TB_CFG_PKG_WRITE);
677 if (res.err)
678 return res;
679
680 res.response_port = reply.addr.port;
681 res.err = check_config_address(reply.addr, space, offset, length);
682 return res;
683}
684
685int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,
686 enum tb_cfg_space space, u32 offset, u32 length)
687{
688 struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port,
689 space, offset, length, TB_CFG_DEFAULT_TIMEOUT);
690 if (res.err == 1) {
691 tb_cfg_print_error(ctl, &res);
692 return -EIO;
693 }
694 WARN(res.err, "tb_cfg_read: %d\n", res.err);
695 return res.err;
696}
697
698int tb_cfg_write(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,
699 enum tb_cfg_space space, u32 offset, u32 length)
700{
701 struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port,
702 space, offset, length, TB_CFG_DEFAULT_TIMEOUT);
703 if (res.err == 1) {
704 tb_cfg_print_error(ctl, &res);
705 return -EIO;
706 }
707 WARN(res.err, "tb_cfg_write: %d\n", res.err);
708 return res.err;
709}
710
711/**
712 * tb_cfg_get_upstream_port() - get upstream port number of switch at route
713 *
714 * Reads the first dword from the switches TB_CFG_SWITCH config area and
715 * returns the port number from which the reply originated.
716 *
717 * Return: Returns the upstream port number on success or an error code on
718 * failure.
719 */
720int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route)
721{
722 u32 dummy;
723 struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0,
724 TB_CFG_SWITCH, 0, 1,
725 TB_CFG_DEFAULT_TIMEOUT);
726 if (res.err == 1)
727 return -EIO;
728 if (res.err)
729 return res.err;
730 return res.response_port;
731}