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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_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 = NULL, *iter;
162
163 mutex_lock(&pkg->ctl->request_queue_lock);
164 list_for_each_entry(iter, &pkg->ctl->request_queue, list) {
165 tb_cfg_request_get(iter);
166 if (iter->match(iter, pkg)) {
167 req = iter;
168 break;
169 }
170 tb_cfg_request_put(iter);
171 }
172 mutex_unlock(&pkg->ctl->request_queue_lock);
173
174 return req;
175}
176
177/* utility functions */
178
179
180static int check_header(const struct ctl_pkg *pkg, u32 len,
181 enum tb_cfg_pkg_type type, u64 route)
182{
183 struct tb_cfg_header *header = pkg->buffer;
184
185 /* check frame, TODO: frame flags */
186 if (WARN(len != pkg->frame.size,
187 "wrong framesize (expected %#x, got %#x)\n",
188 len, pkg->frame.size))
189 return -EIO;
190 if (WARN(type != pkg->frame.eof, "wrong eof (expected %#x, got %#x)\n",
191 type, pkg->frame.eof))
192 return -EIO;
193 if (WARN(pkg->frame.sof, "wrong sof (expected 0x0, got %#x)\n",
194 pkg->frame.sof))
195 return -EIO;
196
197 /* check header */
198 if (WARN(header->unknown != 1 << 9,
199 "header->unknown is %#x\n", header->unknown))
200 return -EIO;
201 if (WARN(route != tb_cfg_get_route(header),
202 "wrong route (expected %llx, got %llx)",
203 route, tb_cfg_get_route(header)))
204 return -EIO;
205 return 0;
206}
207
208static int check_config_address(struct tb_cfg_address addr,
209 enum tb_cfg_space space, u32 offset,
210 u32 length)
211{
212 if (WARN(addr.zero, "addr.zero is %#x\n", addr.zero))
213 return -EIO;
214 if (WARN(space != addr.space, "wrong space (expected %x, got %x\n)",
215 space, addr.space))
216 return -EIO;
217 if (WARN(offset != addr.offset, "wrong offset (expected %x, got %x\n)",
218 offset, addr.offset))
219 return -EIO;
220 if (WARN(length != addr.length, "wrong space (expected %x, got %x\n)",
221 length, addr.length))
222 return -EIO;
223 /*
224 * We cannot check addr->port as it is set to the upstream port of the
225 * sender.
226 */
227 return 0;
228}
229
230static struct tb_cfg_result decode_error(const struct ctl_pkg *response)
231{
232 struct cfg_error_pkg *pkg = response->buffer;
233 struct tb_ctl *ctl = response->ctl;
234 struct tb_cfg_result res = { 0 };
235 res.response_route = tb_cfg_get_route(&pkg->header);
236 res.response_port = 0;
237 res.err = check_header(response, sizeof(*pkg), TB_CFG_PKG_ERROR,
238 tb_cfg_get_route(&pkg->header));
239 if (res.err)
240 return res;
241
242 if (pkg->zero1)
243 tb_ctl_warn(ctl, "pkg->zero1 is %#x\n", pkg->zero1);
244 if (pkg->zero2)
245 tb_ctl_warn(ctl, "pkg->zero2 is %#x\n", pkg->zero2);
246 if (pkg->zero3)
247 tb_ctl_warn(ctl, "pkg->zero3 is %#x\n", pkg->zero3);
248
249 res.err = 1;
250 res.tb_error = pkg->error;
251 res.response_port = pkg->port;
252 return res;
253
254}
255
256static struct tb_cfg_result parse_header(const struct ctl_pkg *pkg, u32 len,
257 enum tb_cfg_pkg_type type, u64 route)
258{
259 struct tb_cfg_header *header = pkg->buffer;
260 struct tb_cfg_result res = { 0 };
261
262 if (pkg->frame.eof == TB_CFG_PKG_ERROR)
263 return decode_error(pkg);
264
265 res.response_port = 0; /* will be updated later for cfg_read/write */
266 res.response_route = tb_cfg_get_route(header);
267 res.err = check_header(pkg, len, type, route);
268 return res;
269}
270
271static void tb_cfg_print_error(struct tb_ctl *ctl,
272 const struct tb_cfg_result *res)
273{
274 WARN_ON(res->err != 1);
275 switch (res->tb_error) {
276 case TB_CFG_ERROR_PORT_NOT_CONNECTED:
277 /* Port is not connected. This can happen during surprise
278 * removal. Do not warn. */
279 return;
280 case TB_CFG_ERROR_INVALID_CONFIG_SPACE:
281 /*
282 * Invalid cfg_space/offset/length combination in
283 * cfg_read/cfg_write.
284 */
285 tb_ctl_dbg(ctl, "%llx:%x: invalid config space or offset\n",
286 res->response_route, res->response_port);
287 return;
288 case TB_CFG_ERROR_NO_SUCH_PORT:
289 /*
290 * - The route contains a non-existent port.
291 * - The route contains a non-PHY port (e.g. PCIe).
292 * - The port in cfg_read/cfg_write does not exist.
293 */
294 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n",
295 res->response_route, res->response_port);
296 return;
297 case TB_CFG_ERROR_LOOP:
298 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n",
299 res->response_route, res->response_port);
300 return;
301 case TB_CFG_ERROR_LOCK:
302 tb_ctl_warn(ctl, "%llx:%x: downstream port is locked\n",
303 res->response_route, res->response_port);
304 return;
305 default:
306 /* 5,6,7,9 and 11 are also valid error codes */
307 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n",
308 res->response_route, res->response_port);
309 return;
310 }
311}
312
313static __be32 tb_crc(const void *data, size_t len)
314{
315 return cpu_to_be32(~__crc32c_le(~0, data, len));
316}
317
318static void tb_ctl_pkg_free(struct ctl_pkg *pkg)
319{
320 if (pkg) {
321 dma_pool_free(pkg->ctl->frame_pool,
322 pkg->buffer, pkg->frame.buffer_phy);
323 kfree(pkg);
324 }
325}
326
327static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl)
328{
329 struct ctl_pkg *pkg = kzalloc(sizeof(*pkg), GFP_KERNEL);
330 if (!pkg)
331 return NULL;
332 pkg->ctl = ctl;
333 pkg->buffer = dma_pool_alloc(ctl->frame_pool, GFP_KERNEL,
334 &pkg->frame.buffer_phy);
335 if (!pkg->buffer) {
336 kfree(pkg);
337 return NULL;
338 }
339 return pkg;
340}
341
342
343/* RX/TX handling */
344
345static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
346 bool canceled)
347{
348 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
349 tb_ctl_pkg_free(pkg);
350}
351
352/*
353 * tb_cfg_tx() - transmit a packet on the control channel
354 *
355 * len must be a multiple of four.
356 *
357 * Return: Returns 0 on success or an error code on failure.
358 */
359static int tb_ctl_tx(struct tb_ctl *ctl, const void *data, size_t len,
360 enum tb_cfg_pkg_type type)
361{
362 int res;
363 struct ctl_pkg *pkg;
364 if (len % 4 != 0) { /* required for le->be conversion */
365 tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len);
366 return -EINVAL;
367 }
368 if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */
369 tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n",
370 len, TB_FRAME_SIZE - 4);
371 return -EINVAL;
372 }
373 pkg = tb_ctl_pkg_alloc(ctl);
374 if (!pkg)
375 return -ENOMEM;
376 pkg->frame.callback = tb_ctl_tx_callback;
377 pkg->frame.size = len + 4;
378 pkg->frame.sof = type;
379 pkg->frame.eof = type;
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 */
392static 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 return ctl->callback(ctl->callback_data, type, pkg->buffer, size);
396}
397
398static void tb_ctl_rx_submit(struct ctl_pkg *pkg)
399{
400 tb_ring_rx(pkg->ctl->rx, &pkg->frame); /*
401 * We ignore failures during stop.
402 * All rx packets are referenced
403 * from ctl->rx_packets, so we do
404 * not loose them.
405 */
406}
407
408static int tb_async_error(const struct ctl_pkg *pkg)
409{
410 const struct cfg_error_pkg *error = pkg->buffer;
411
412 if (pkg->frame.eof != TB_CFG_PKG_ERROR)
413 return false;
414
415 switch (error->error) {
416 case TB_CFG_ERROR_LINK_ERROR:
417 case TB_CFG_ERROR_HEC_ERROR_DETECTED:
418 case TB_CFG_ERROR_FLOW_CONTROL_ERROR:
419 return true;
420
421 default:
422 return false;
423 }
424}
425
426static void tb_ctl_rx_callback(struct tb_ring *ring, struct ring_frame *frame,
427 bool canceled)
428{
429 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
430 struct tb_cfg_request *req;
431 __be32 crc32;
432
433 if (canceled)
434 return; /*
435 * ring is stopped, packet is referenced from
436 * ctl->rx_packets.
437 */
438
439 if (frame->size < 4 || frame->size % 4 != 0) {
440 tb_ctl_err(pkg->ctl, "RX: invalid size %#x, dropping packet\n",
441 frame->size);
442 goto rx;
443 }
444
445 frame->size -= 4; /* remove checksum */
446 crc32 = tb_crc(pkg->buffer, frame->size);
447 be32_to_cpu_array(pkg->buffer, pkg->buffer, frame->size / 4);
448
449 switch (frame->eof) {
450 case TB_CFG_PKG_READ:
451 case TB_CFG_PKG_WRITE:
452 case TB_CFG_PKG_ERROR:
453 case TB_CFG_PKG_OVERRIDE:
454 case TB_CFG_PKG_RESET:
455 if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {
456 tb_ctl_err(pkg->ctl,
457 "RX: checksum mismatch, dropping packet\n");
458 goto rx;
459 }
460 if (tb_async_error(pkg)) {
461 tb_ctl_handle_event(pkg->ctl, frame->eof,
462 pkg, frame->size);
463 goto rx;
464 }
465 break;
466
467 case TB_CFG_PKG_EVENT:
468 case TB_CFG_PKG_XDOMAIN_RESP:
469 case TB_CFG_PKG_XDOMAIN_REQ:
470 if (*(__be32 *)(pkg->buffer + frame->size) != crc32) {
471 tb_ctl_err(pkg->ctl,
472 "RX: checksum mismatch, dropping packet\n");
473 goto rx;
474 }
475 fallthrough;
476 case TB_CFG_PKG_ICM_EVENT:
477 if (tb_ctl_handle_event(pkg->ctl, frame->eof, pkg, frame->size))
478 goto rx;
479 break;
480
481 default:
482 break;
483 }
484
485 /*
486 * The received packet will be processed only if there is an
487 * active request and that the packet is what is expected. This
488 * prevents packets such as replies coming after timeout has
489 * triggered from messing with the active requests.
490 */
491 req = tb_cfg_request_find(pkg->ctl, pkg);
492 if (req) {
493 if (req->copy(req, pkg))
494 schedule_work(&req->work);
495 tb_cfg_request_put(req);
496 }
497
498rx:
499 tb_ctl_rx_submit(pkg);
500}
501
502static void tb_cfg_request_work(struct work_struct *work)
503{
504 struct tb_cfg_request *req = container_of(work, typeof(*req), work);
505
506 if (!test_bit(TB_CFG_REQUEST_CANCELED, &req->flags))
507 req->callback(req->callback_data);
508
509 tb_cfg_request_dequeue(req);
510 tb_cfg_request_put(req);
511}
512
513/**
514 * tb_cfg_request() - Start control request not waiting for it to complete
515 * @ctl: Control channel to use
516 * @req: Request to start
517 * @callback: Callback called when the request is completed
518 * @callback_data: Data to be passed to @callback
519 *
520 * This queues @req on the given control channel without waiting for it
521 * to complete. When the request completes @callback is called.
522 */
523int tb_cfg_request(struct tb_ctl *ctl, struct tb_cfg_request *req,
524 void (*callback)(void *), void *callback_data)
525{
526 int ret;
527
528 req->flags = 0;
529 req->callback = callback;
530 req->callback_data = callback_data;
531 INIT_WORK(&req->work, tb_cfg_request_work);
532 INIT_LIST_HEAD(&req->list);
533
534 tb_cfg_request_get(req);
535 ret = tb_cfg_request_enqueue(ctl, req);
536 if (ret)
537 goto err_put;
538
539 ret = tb_ctl_tx(ctl, req->request, req->request_size,
540 req->request_type);
541 if (ret)
542 goto err_dequeue;
543
544 if (!req->response)
545 schedule_work(&req->work);
546
547 return 0;
548
549err_dequeue:
550 tb_cfg_request_dequeue(req);
551err_put:
552 tb_cfg_request_put(req);
553
554 return ret;
555}
556
557/**
558 * tb_cfg_request_cancel() - Cancel a control request
559 * @req: Request to cancel
560 * @err: Error to assign to the request
561 *
562 * This function can be used to cancel ongoing request. It will wait
563 * until the request is not active anymore.
564 */
565void tb_cfg_request_cancel(struct tb_cfg_request *req, int err)
566{
567 set_bit(TB_CFG_REQUEST_CANCELED, &req->flags);
568 schedule_work(&req->work);
569 wait_event(tb_cfg_request_cancel_queue, !tb_cfg_request_is_active(req));
570 req->result.err = err;
571}
572
573static void tb_cfg_request_complete(void *data)
574{
575 complete(data);
576}
577
578/**
579 * tb_cfg_request_sync() - Start control request and wait until it completes
580 * @ctl: Control channel to use
581 * @req: Request to start
582 * @timeout_msec: Timeout how long to wait @req to complete
583 *
584 * Starts a control request and waits until it completes. If timeout
585 * triggers the request is canceled before function returns. Note the
586 * caller needs to make sure only one message for given switch is active
587 * at a time.
588 */
589struct tb_cfg_result tb_cfg_request_sync(struct tb_ctl *ctl,
590 struct tb_cfg_request *req,
591 int timeout_msec)
592{
593 unsigned long timeout = msecs_to_jiffies(timeout_msec);
594 struct tb_cfg_result res = { 0 };
595 DECLARE_COMPLETION_ONSTACK(done);
596 int ret;
597
598 ret = tb_cfg_request(ctl, req, tb_cfg_request_complete, &done);
599 if (ret) {
600 res.err = ret;
601 return res;
602 }
603
604 if (!wait_for_completion_timeout(&done, timeout))
605 tb_cfg_request_cancel(req, -ETIMEDOUT);
606
607 flush_work(&req->work);
608
609 return req->result;
610}
611
612/* public interface, alloc/start/stop/free */
613
614/**
615 * tb_ctl_alloc() - allocate a control channel
616 * @nhi: Pointer to NHI
617 * @timeout_msec: Default timeout used with non-raw control messages
618 * @cb: Callback called for plug events
619 * @cb_data: Data passed to @cb
620 *
621 * cb will be invoked once for every hot plug event.
622 *
623 * Return: Returns a pointer on success or NULL on failure.
624 */
625struct tb_ctl *tb_ctl_alloc(struct tb_nhi *nhi, int timeout_msec, event_cb cb,
626 void *cb_data)
627{
628 int i;
629 struct tb_ctl *ctl = kzalloc(sizeof(*ctl), GFP_KERNEL);
630 if (!ctl)
631 return NULL;
632 ctl->nhi = nhi;
633 ctl->timeout_msec = timeout_msec;
634 ctl->callback = cb;
635 ctl->callback_data = cb_data;
636
637 mutex_init(&ctl->request_queue_lock);
638 INIT_LIST_HEAD(&ctl->request_queue);
639 ctl->frame_pool = dma_pool_create("thunderbolt_ctl", &nhi->pdev->dev,
640 TB_FRAME_SIZE, 4, 0);
641 if (!ctl->frame_pool)
642 goto err;
643
644 ctl->tx = tb_ring_alloc_tx(nhi, 0, 10, RING_FLAG_NO_SUSPEND);
645 if (!ctl->tx)
646 goto err;
647
648 ctl->rx = tb_ring_alloc_rx(nhi, 0, 10, RING_FLAG_NO_SUSPEND, 0, 0xffff,
649 0xffff, NULL, NULL);
650 if (!ctl->rx)
651 goto err;
652
653 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++) {
654 ctl->rx_packets[i] = tb_ctl_pkg_alloc(ctl);
655 if (!ctl->rx_packets[i])
656 goto err;
657 ctl->rx_packets[i]->frame.callback = tb_ctl_rx_callback;
658 }
659
660 tb_ctl_dbg(ctl, "control channel created\n");
661 return ctl;
662err:
663 tb_ctl_free(ctl);
664 return NULL;
665}
666
667/**
668 * tb_ctl_free() - free a control channel
669 * @ctl: Control channel to free
670 *
671 * Must be called after tb_ctl_stop.
672 *
673 * Must NOT be called from ctl->callback.
674 */
675void tb_ctl_free(struct tb_ctl *ctl)
676{
677 int i;
678
679 if (!ctl)
680 return;
681
682 if (ctl->rx)
683 tb_ring_free(ctl->rx);
684 if (ctl->tx)
685 tb_ring_free(ctl->tx);
686
687 /* free RX packets */
688 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
689 tb_ctl_pkg_free(ctl->rx_packets[i]);
690
691
692 dma_pool_destroy(ctl->frame_pool);
693 kfree(ctl);
694}
695
696/**
697 * tb_ctl_start() - start/resume the control channel
698 * @ctl: Control channel to start
699 */
700void tb_ctl_start(struct tb_ctl *ctl)
701{
702 int i;
703 tb_ctl_dbg(ctl, "control channel starting...\n");
704 tb_ring_start(ctl->tx); /* is used to ack hotplug packets, start first */
705 tb_ring_start(ctl->rx);
706 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
707 tb_ctl_rx_submit(ctl->rx_packets[i]);
708
709 ctl->running = true;
710}
711
712/**
713 * tb_ctl_stop() - pause the control channel
714 * @ctl: Control channel to stop
715 *
716 * All invocations of ctl->callback will have finished after this method
717 * returns.
718 *
719 * Must NOT be called from ctl->callback.
720 */
721void tb_ctl_stop(struct tb_ctl *ctl)
722{
723 mutex_lock(&ctl->request_queue_lock);
724 ctl->running = false;
725 mutex_unlock(&ctl->request_queue_lock);
726
727 tb_ring_stop(ctl->rx);
728 tb_ring_stop(ctl->tx);
729
730 if (!list_empty(&ctl->request_queue))
731 tb_ctl_WARN(ctl, "dangling request in request_queue\n");
732 INIT_LIST_HEAD(&ctl->request_queue);
733 tb_ctl_dbg(ctl, "control channel stopped\n");
734}
735
736/* public interface, commands */
737
738/**
739 * tb_cfg_ack_plug() - Ack hot plug/unplug event
740 * @ctl: Control channel to use
741 * @route: Router that originated the event
742 * @port: Port where the hot plug/unplug happened
743 * @unplug: Ack hot plug or unplug
744 *
745 * Call this as response for hot plug/unplug event to ack it.
746 * Returns %0 on success or an error code on failure.
747 */
748int tb_cfg_ack_plug(struct tb_ctl *ctl, u64 route, u32 port, bool unplug)
749{
750 struct cfg_error_pkg pkg = {
751 .header = tb_cfg_make_header(route),
752 .port = port,
753 .error = TB_CFG_ERROR_ACK_PLUG_EVENT,
754 .pg = unplug ? TB_CFG_ERROR_PG_HOT_UNPLUG
755 : TB_CFG_ERROR_PG_HOT_PLUG,
756 };
757 tb_ctl_dbg(ctl, "acking hot %splug event on %llx:%x\n",
758 unplug ? "un" : "", route, port);
759 return tb_ctl_tx(ctl, &pkg, sizeof(pkg), TB_CFG_PKG_ERROR);
760}
761
762static bool tb_cfg_match(const struct tb_cfg_request *req,
763 const struct ctl_pkg *pkg)
764{
765 u64 route = tb_cfg_get_route(pkg->buffer) & ~BIT_ULL(63);
766
767 if (pkg->frame.eof == TB_CFG_PKG_ERROR)
768 return true;
769
770 if (pkg->frame.eof != req->response_type)
771 return false;
772 if (route != tb_cfg_get_route(req->request))
773 return false;
774 if (pkg->frame.size != req->response_size)
775 return false;
776
777 if (pkg->frame.eof == TB_CFG_PKG_READ ||
778 pkg->frame.eof == TB_CFG_PKG_WRITE) {
779 const struct cfg_read_pkg *req_hdr = req->request;
780 const struct cfg_read_pkg *res_hdr = pkg->buffer;
781
782 if (req_hdr->addr.seq != res_hdr->addr.seq)
783 return false;
784 }
785
786 return true;
787}
788
789static bool tb_cfg_copy(struct tb_cfg_request *req, const struct ctl_pkg *pkg)
790{
791 struct tb_cfg_result res;
792
793 /* Now make sure it is in expected format */
794 res = parse_header(pkg, req->response_size, req->response_type,
795 tb_cfg_get_route(req->request));
796 if (!res.err)
797 memcpy(req->response, pkg->buffer, req->response_size);
798
799 req->result = res;
800
801 /* Always complete when first response is received */
802 return true;
803}
804
805/**
806 * tb_cfg_reset() - send a reset packet and wait for a response
807 * @ctl: Control channel pointer
808 * @route: Router string for the router to send reset
809 *
810 * If the switch at route is incorrectly configured then we will not receive a
811 * reply (even though the switch will reset). The caller should check for
812 * -ETIMEDOUT and attempt to reconfigure the switch.
813 */
814struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route)
815{
816 struct cfg_reset_pkg request = { .header = tb_cfg_make_header(route) };
817 struct tb_cfg_result res = { 0 };
818 struct tb_cfg_header reply;
819 struct tb_cfg_request *req;
820
821 req = tb_cfg_request_alloc();
822 if (!req) {
823 res.err = -ENOMEM;
824 return res;
825 }
826
827 req->match = tb_cfg_match;
828 req->copy = tb_cfg_copy;
829 req->request = &request;
830 req->request_size = sizeof(request);
831 req->request_type = TB_CFG_PKG_RESET;
832 req->response = &reply;
833 req->response_size = sizeof(reply);
834 req->response_type = TB_CFG_PKG_RESET;
835
836 res = tb_cfg_request_sync(ctl, req, ctl->timeout_msec);
837
838 tb_cfg_request_put(req);
839
840 return res;
841}
842
843/**
844 * tb_cfg_read_raw() - read from config space into buffer
845 * @ctl: Pointer to the control channel
846 * @buffer: Buffer where the data is read
847 * @route: Route string of the router
848 * @port: Port number when reading from %TB_CFG_PORT, %0 otherwise
849 * @space: Config space selector
850 * @offset: Dword word offset of the register to start reading
851 * @length: Number of dwords to read
852 * @timeout_msec: Timeout in ms how long to wait for the response
853 *
854 * Reads from router config space without translating the possible error.
855 */
856struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer,
857 u64 route, u32 port, enum tb_cfg_space space,
858 u32 offset, u32 length, int timeout_msec)
859{
860 struct tb_cfg_result res = { 0 };
861 struct cfg_read_pkg request = {
862 .header = tb_cfg_make_header(route),
863 .addr = {
864 .port = port,
865 .space = space,
866 .offset = offset,
867 .length = length,
868 },
869 };
870 struct cfg_write_pkg reply;
871 int retries = 0;
872
873 while (retries < TB_CTL_RETRIES) {
874 struct tb_cfg_request *req;
875
876 req = tb_cfg_request_alloc();
877 if (!req) {
878 res.err = -ENOMEM;
879 return res;
880 }
881
882 request.addr.seq = retries++;
883
884 req->match = tb_cfg_match;
885 req->copy = tb_cfg_copy;
886 req->request = &request;
887 req->request_size = sizeof(request);
888 req->request_type = TB_CFG_PKG_READ;
889 req->response = &reply;
890 req->response_size = 12 + 4 * length;
891 req->response_type = TB_CFG_PKG_READ;
892
893 res = tb_cfg_request_sync(ctl, req, timeout_msec);
894
895 tb_cfg_request_put(req);
896
897 if (res.err != -ETIMEDOUT)
898 break;
899
900 /* Wait a bit (arbitrary time) until we send a retry */
901 usleep_range(10, 100);
902 }
903
904 if (res.err)
905 return res;
906
907 res.response_port = reply.addr.port;
908 res.err = check_config_address(reply.addr, space, offset, length);
909 if (!res.err)
910 memcpy(buffer, &reply.data, 4 * length);
911 return res;
912}
913
914/**
915 * tb_cfg_write_raw() - write from buffer into config space
916 * @ctl: Pointer to the control channel
917 * @buffer: Data to write
918 * @route: Route string of the router
919 * @port: Port number when writing to %TB_CFG_PORT, %0 otherwise
920 * @space: Config space selector
921 * @offset: Dword word offset of the register to start writing
922 * @length: Number of dwords to write
923 * @timeout_msec: Timeout in ms how long to wait for the response
924 *
925 * Writes to router config space without translating the possible error.
926 */
927struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, const void *buffer,
928 u64 route, u32 port, enum tb_cfg_space space,
929 u32 offset, u32 length, int timeout_msec)
930{
931 struct tb_cfg_result res = { 0 };
932 struct cfg_write_pkg request = {
933 .header = tb_cfg_make_header(route),
934 .addr = {
935 .port = port,
936 .space = space,
937 .offset = offset,
938 .length = length,
939 },
940 };
941 struct cfg_read_pkg reply;
942 int retries = 0;
943
944 memcpy(&request.data, buffer, length * 4);
945
946 while (retries < TB_CTL_RETRIES) {
947 struct tb_cfg_request *req;
948
949 req = tb_cfg_request_alloc();
950 if (!req) {
951 res.err = -ENOMEM;
952 return res;
953 }
954
955 request.addr.seq = retries++;
956
957 req->match = tb_cfg_match;
958 req->copy = tb_cfg_copy;
959 req->request = &request;
960 req->request_size = 12 + 4 * length;
961 req->request_type = TB_CFG_PKG_WRITE;
962 req->response = &reply;
963 req->response_size = sizeof(reply);
964 req->response_type = TB_CFG_PKG_WRITE;
965
966 res = tb_cfg_request_sync(ctl, req, timeout_msec);
967
968 tb_cfg_request_put(req);
969
970 if (res.err != -ETIMEDOUT)
971 break;
972
973 /* Wait a bit (arbitrary time) until we send a retry */
974 usleep_range(10, 100);
975 }
976
977 if (res.err)
978 return res;
979
980 res.response_port = reply.addr.port;
981 res.err = check_config_address(reply.addr, space, offset, length);
982 return res;
983}
984
985static int tb_cfg_get_error(struct tb_ctl *ctl, enum tb_cfg_space space,
986 const struct tb_cfg_result *res)
987{
988 /*
989 * For unimplemented ports access to port config space may return
990 * TB_CFG_ERROR_INVALID_CONFIG_SPACE (alternatively their type is
991 * set to TB_TYPE_INACTIVE). In the former case return -ENODEV so
992 * that the caller can mark the port as disabled.
993 */
994 if (space == TB_CFG_PORT &&
995 res->tb_error == TB_CFG_ERROR_INVALID_CONFIG_SPACE)
996 return -ENODEV;
997
998 tb_cfg_print_error(ctl, res);
999
1000 if (res->tb_error == TB_CFG_ERROR_LOCK)
1001 return -EACCES;
1002 else if (res->tb_error == TB_CFG_ERROR_PORT_NOT_CONNECTED)
1003 return -ENOTCONN;
1004
1005 return -EIO;
1006}
1007
1008int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,
1009 enum tb_cfg_space space, u32 offset, u32 length)
1010{
1011 struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port,
1012 space, offset, length, ctl->timeout_msec);
1013 switch (res.err) {
1014 case 0:
1015 /* Success */
1016 break;
1017
1018 case 1:
1019 /* Thunderbolt error, tb_error holds the actual number */
1020 return tb_cfg_get_error(ctl, space, &res);
1021
1022 case -ETIMEDOUT:
1023 tb_ctl_warn(ctl, "%llx: timeout reading config space %u from %#x\n",
1024 route, space, offset);
1025 break;
1026
1027 default:
1028 WARN(1, "tb_cfg_read: %d\n", res.err);
1029 break;
1030 }
1031 return res.err;
1032}
1033
1034int tb_cfg_write(struct tb_ctl *ctl, const void *buffer, u64 route, u32 port,
1035 enum tb_cfg_space space, u32 offset, u32 length)
1036{
1037 struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port,
1038 space, offset, length, ctl->timeout_msec);
1039 switch (res.err) {
1040 case 0:
1041 /* Success */
1042 break;
1043
1044 case 1:
1045 /* Thunderbolt error, tb_error holds the actual number */
1046 return tb_cfg_get_error(ctl, space, &res);
1047
1048 case -ETIMEDOUT:
1049 tb_ctl_warn(ctl, "%llx: timeout writing config space %u to %#x\n",
1050 route, space, offset);
1051 break;
1052
1053 default:
1054 WARN(1, "tb_cfg_write: %d\n", res.err);
1055 break;
1056 }
1057 return res.err;
1058}
1059
1060/**
1061 * tb_cfg_get_upstream_port() - get upstream port number of switch at route
1062 * @ctl: Pointer to the control channel
1063 * @route: Route string of the router
1064 *
1065 * Reads the first dword from the switches TB_CFG_SWITCH config area and
1066 * returns the port number from which the reply originated.
1067 *
1068 * Return: Returns the upstream port number on success or an error code on
1069 * failure.
1070 */
1071int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route)
1072{
1073 u32 dummy;
1074 struct tb_cfg_result res = tb_cfg_read_raw(ctl, &dummy, route, 0,
1075 TB_CFG_SWITCH, 0, 1,
1076 ctl->timeout_msec);
1077 if (res.err == 1)
1078 return -EIO;
1079 if (res.err)
1080 return res.err;
1081 return res.response_port;
1082}
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 of 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}