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(size: sizeof(*req), GFP_KERNEL);
83 if (!req)
84 return NULL;
85
86 kref_init(kref: &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(kref: &req->kref);
99 mutex_unlock(lock: &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(objp: 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(kref: &req->kref, release: tb_cfg_request_destroy);
120 mutex_unlock(lock: &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(lock: &ctl->request_queue_lock);
132 return -ENOTCONN;
133 }
134 req->ctl = ctl;
135 list_add_tail(new: &req->list, head: &ctl->request_queue);
136 set_bit(TB_CFG_REQUEST_ACTIVE, addr: &req->flags);
137 mutex_unlock(lock: &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(entry: &req->list);
147 clear_bit(TB_CFG_REQUEST_ACTIVE, addr: &req->flags);
148 if (test_bit(TB_CFG_REQUEST_CANCELED, &req->flags))
149 wake_up(&tb_cfg_request_cancel_queue);
150 mutex_unlock(lock: &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(req: iter);
166 if (iter->match(iter, pkg)) {
167 req = iter;
168 break;
169 }
170 tb_cfg_request_put(req: iter);
171 }
172 mutex_unlock(lock: &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_cfg_result res = { 0 };
234 res.response_route = tb_cfg_get_route(header: &pkg->header);
235 res.response_port = 0;
236 res.err = check_header(pkg: response, len: sizeof(*pkg), type: TB_CFG_PKG_ERROR,
237 route: tb_cfg_get_route(header: &pkg->header));
238 if (res.err)
239 return res;
240
241 res.err = 1;
242 res.tb_error = pkg->error;
243 res.response_port = pkg->port;
244 return res;
245
246}
247
248static struct tb_cfg_result parse_header(const struct ctl_pkg *pkg, u32 len,
249 enum tb_cfg_pkg_type type, u64 route)
250{
251 struct tb_cfg_header *header = pkg->buffer;
252 struct tb_cfg_result res = { 0 };
253
254 if (pkg->frame.eof == TB_CFG_PKG_ERROR)
255 return decode_error(response: pkg);
256
257 res.response_port = 0; /* will be updated later for cfg_read/write */
258 res.response_route = tb_cfg_get_route(header);
259 res.err = check_header(pkg, len, type, route);
260 return res;
261}
262
263static void tb_cfg_print_error(struct tb_ctl *ctl,
264 const struct tb_cfg_result *res)
265{
266 WARN_ON(res->err != 1);
267 switch (res->tb_error) {
268 case TB_CFG_ERROR_PORT_NOT_CONNECTED:
269 /* Port is not connected. This can happen during surprise
270 * removal. Do not warn. */
271 return;
272 case TB_CFG_ERROR_INVALID_CONFIG_SPACE:
273 /*
274 * Invalid cfg_space/offset/length combination in
275 * cfg_read/cfg_write.
276 */
277 tb_ctl_dbg(ctl, "%llx:%x: invalid config space or offset\n",
278 res->response_route, res->response_port);
279 return;
280 case TB_CFG_ERROR_NO_SUCH_PORT:
281 /*
282 * - The route contains a non-existent port.
283 * - The route contains a non-PHY port (e.g. PCIe).
284 * - The port in cfg_read/cfg_write does not exist.
285 */
286 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Invalid port\n",
287 res->response_route, res->response_port);
288 return;
289 case TB_CFG_ERROR_LOOP:
290 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Route contains a loop\n",
291 res->response_route, res->response_port);
292 return;
293 case TB_CFG_ERROR_LOCK:
294 tb_ctl_warn(ctl, "%llx:%x: downstream port is locked\n",
295 res->response_route, res->response_port);
296 return;
297 default:
298 /* 5,6,7,9 and 11 are also valid error codes */
299 tb_ctl_WARN(ctl, "CFG_ERROR(%llx:%x): Unknown error\n",
300 res->response_route, res->response_port);
301 return;
302 }
303}
304
305static __be32 tb_crc(const void *data, size_t len)
306{
307 return cpu_to_be32(~__crc32c_le(~0, data, len));
308}
309
310static void tb_ctl_pkg_free(struct ctl_pkg *pkg)
311{
312 if (pkg) {
313 dma_pool_free(pool: pkg->ctl->frame_pool,
314 vaddr: pkg->buffer, addr: pkg->frame.buffer_phy);
315 kfree(objp: pkg);
316 }
317}
318
319static struct ctl_pkg *tb_ctl_pkg_alloc(struct tb_ctl *ctl)
320{
321 struct ctl_pkg *pkg = kzalloc(size: sizeof(*pkg), GFP_KERNEL);
322 if (!pkg)
323 return NULL;
324 pkg->ctl = ctl;
325 pkg->buffer = dma_pool_alloc(pool: ctl->frame_pool, GFP_KERNEL,
326 handle: &pkg->frame.buffer_phy);
327 if (!pkg->buffer) {
328 kfree(objp: pkg);
329 return NULL;
330 }
331 return pkg;
332}
333
334
335/* RX/TX handling */
336
337static void tb_ctl_tx_callback(struct tb_ring *ring, struct ring_frame *frame,
338 bool canceled)
339{
340 struct ctl_pkg *pkg = container_of(frame, typeof(*pkg), frame);
341 tb_ctl_pkg_free(pkg);
342}
343
344/*
345 * tb_cfg_tx() - transmit a packet on the control channel
346 *
347 * len must be a multiple of four.
348 *
349 * Return: Returns 0 on success or an error code on failure.
350 */
351static int tb_ctl_tx(struct tb_ctl *ctl, const void *data, size_t len,
352 enum tb_cfg_pkg_type type)
353{
354 int res;
355 struct ctl_pkg *pkg;
356 if (len % 4 != 0) { /* required for le->be conversion */
357 tb_ctl_WARN(ctl, "TX: invalid size: %zu\n", len);
358 return -EINVAL;
359 }
360 if (len > TB_FRAME_SIZE - 4) { /* checksum is 4 bytes */
361 tb_ctl_WARN(ctl, "TX: packet too large: %zu/%d\n",
362 len, TB_FRAME_SIZE - 4);
363 return -EINVAL;
364 }
365 pkg = tb_ctl_pkg_alloc(ctl);
366 if (!pkg)
367 return -ENOMEM;
368 pkg->frame.callback = tb_ctl_tx_callback;
369 pkg->frame.size = len + 4;
370 pkg->frame.sof = type;
371 pkg->frame.eof = type;
372 cpu_to_be32_array(dst: pkg->buffer, src: data, len: len / 4);
373 *(__be32 *) (pkg->buffer + len) = tb_crc(data: pkg->buffer, len);
374
375 res = tb_ring_tx(ring: ctl->tx, frame: &pkg->frame);
376 if (res) /* ring is stopped */
377 tb_ctl_pkg_free(pkg);
378 return res;
379}
380
381/*
382 * tb_ctl_handle_event() - acknowledge a plug event, invoke ctl->callback
383 */
384static bool tb_ctl_handle_event(struct tb_ctl *ctl, enum tb_cfg_pkg_type type,
385 struct ctl_pkg *pkg, size_t size)
386{
387 return ctl->callback(ctl->callback_data, type, pkg->buffer, size);
388}
389
390static void tb_ctl_rx_submit(struct ctl_pkg *pkg)
391{
392 tb_ring_rx(ring: pkg->ctl->rx, frame: &pkg->frame); /*
393 * We ignore failures during stop.
394 * All rx packets are referenced
395 * from ctl->rx_packets, so we do
396 * not loose them.
397 */
398}
399
400static int tb_async_error(const struct ctl_pkg *pkg)
401{
402 const struct cfg_error_pkg *error = pkg->buffer;
403
404 if (pkg->frame.eof != TB_CFG_PKG_ERROR)
405 return false;
406
407 switch (error->error) {
408 case TB_CFG_ERROR_LINK_ERROR:
409 case TB_CFG_ERROR_HEC_ERROR_DETECTED:
410 case TB_CFG_ERROR_FLOW_CONTROL_ERROR:
411 case TB_CFG_ERROR_DP_BW:
412 case TB_CFG_ERROR_ROP_CMPLT:
413 case TB_CFG_ERROR_POP_CMPLT:
414 case TB_CFG_ERROR_PCIE_WAKE:
415 case TB_CFG_ERROR_DP_CON_CHANGE:
416 case TB_CFG_ERROR_DPTX_DISCOVERY:
417 case TB_CFG_ERROR_LINK_RECOVERY:
418 case TB_CFG_ERROR_ASYM_LINK:
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(data: pkg->buffer, len: frame->size);
447 be32_to_cpu_array(dst: pkg->buffer, src: pkg->buffer, len: 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(ctl: pkg->ctl, type: frame->eof,
462 pkg, size: 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(ctl: pkg->ctl, type: frame->eof, pkg, size: 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(ctl: pkg->ctl, pkg);
492 if (req) {
493 if (req->copy(req, pkg))
494 schedule_work(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(list: &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, data: req->request, len: req->request_size,
540 type: req->request_type);
541 if (ret)
542 goto err_dequeue;
543
544 if (!req->response)
545 schedule_work(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, addr: &req->flags);
568 schedule_work(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(m: 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, callback: tb_cfg_request_complete, callback_data: &done);
599 if (ret) {
600 res.err = ret;
601 return res;
602 }
603
604 if (!wait_for_completion_timeout(x: &done, timeout))
605 tb_cfg_request_cancel(req, err: -ETIMEDOUT);
606
607 flush_work(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(size: 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(list: &ctl->request_queue);
639 ctl->frame_pool = dma_pool_create(name: "thunderbolt_ctl", dev: &nhi->pdev->dev,
640 TB_FRAME_SIZE, align: 4, allocation: 0);
641 if (!ctl->frame_pool)
642 goto err;
643
644 ctl->tx = tb_ring_alloc_tx(nhi, hop: 0, size: 10, RING_FLAG_NO_SUSPEND);
645 if (!ctl->tx)
646 goto err;
647
648 ctl->rx = tb_ring_alloc_rx(nhi, hop: 0, size: 10, RING_FLAG_NO_SUSPEND, e2e_tx_hop: 0, sof_mask: 0xffff,
649 eof_mask: 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(ring: ctl->rx);
684 if (ctl->tx)
685 tb_ring_free(ring: ctl->tx);
686
687 /* free RX packets */
688 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
689 tb_ctl_pkg_free(pkg: ctl->rx_packets[i]);
690
691
692 dma_pool_destroy(pool: ctl->frame_pool);
693 kfree(objp: 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(ring: ctl->tx); /* is used to ack hotplug packets, start first */
705 tb_ring_start(ring: ctl->rx);
706 for (i = 0; i < TB_CTL_RX_PKG_COUNT; i++)
707 tb_ctl_rx_submit(pkg: 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(lock: &ctl->request_queue_lock);
726
727 tb_ring_stop(ring: ctl->rx);
728 tb_ring_stop(ring: ctl->tx);
729
730 if (!list_empty(head: &ctl->request_queue))
731 tb_ctl_WARN(ctl, "dangling request in request_queue\n");
732 INIT_LIST_HEAD(list: &ctl->request_queue);
733 tb_ctl_dbg(ctl, "control channel stopped\n");
734}
735
736/* public interface, commands */
737
738/**
739 * tb_cfg_ack_notification() - Ack notification
740 * @ctl: Control channel to use
741 * @route: Router that originated the event
742 * @error: Pointer to the notification package
743 *
744 * Call this as response for non-plug notification to ack it. Returns
745 * %0 on success or an error code on failure.
746 */
747int tb_cfg_ack_notification(struct tb_ctl *ctl, u64 route,
748 const struct cfg_error_pkg *error)
749{
750 struct cfg_ack_pkg pkg = {
751 .header = tb_cfg_make_header(route),
752 };
753 const char *name;
754
755 switch (error->error) {
756 case TB_CFG_ERROR_LINK_ERROR:
757 name = "link error";
758 break;
759 case TB_CFG_ERROR_HEC_ERROR_DETECTED:
760 name = "HEC error";
761 break;
762 case TB_CFG_ERROR_FLOW_CONTROL_ERROR:
763 name = "flow control error";
764 break;
765 case TB_CFG_ERROR_DP_BW:
766 name = "DP_BW";
767 break;
768 case TB_CFG_ERROR_ROP_CMPLT:
769 name = "router operation completion";
770 break;
771 case TB_CFG_ERROR_POP_CMPLT:
772 name = "port operation completion";
773 break;
774 case TB_CFG_ERROR_PCIE_WAKE:
775 name = "PCIe wake";
776 break;
777 case TB_CFG_ERROR_DP_CON_CHANGE:
778 name = "DP connector change";
779 break;
780 case TB_CFG_ERROR_DPTX_DISCOVERY:
781 name = "DPTX discovery";
782 break;
783 case TB_CFG_ERROR_LINK_RECOVERY:
784 name = "link recovery";
785 break;
786 case TB_CFG_ERROR_ASYM_LINK:
787 name = "asymmetric link";
788 break;
789 default:
790 name = "unknown";
791 break;
792 }
793
794 tb_ctl_dbg(ctl, "acking %s (%#x) notification on %llx\n", name,
795 error->error, route);
796
797 return tb_ctl_tx(ctl, data: &pkg, len: sizeof(pkg), type: TB_CFG_PKG_NOTIFY_ACK);
798}
799
800/**
801 * tb_cfg_ack_plug() - Ack hot plug/unplug event
802 * @ctl: Control channel to use
803 * @route: Router that originated the event
804 * @port: Port where the hot plug/unplug happened
805 * @unplug: Ack hot plug or unplug
806 *
807 * Call this as response for hot plug/unplug event to ack it.
808 * Returns %0 on success or an error code on failure.
809 */
810int tb_cfg_ack_plug(struct tb_ctl *ctl, u64 route, u32 port, bool unplug)
811{
812 struct cfg_error_pkg pkg = {
813 .header = tb_cfg_make_header(route),
814 .port = port,
815 .error = TB_CFG_ERROR_ACK_PLUG_EVENT,
816 .pg = unplug ? TB_CFG_ERROR_PG_HOT_UNPLUG
817 : TB_CFG_ERROR_PG_HOT_PLUG,
818 };
819 tb_ctl_dbg(ctl, "acking hot %splug event on %llx:%u\n",
820 unplug ? "un" : "", route, port);
821 return tb_ctl_tx(ctl, data: &pkg, len: sizeof(pkg), type: TB_CFG_PKG_ERROR);
822}
823
824static bool tb_cfg_match(const struct tb_cfg_request *req,
825 const struct ctl_pkg *pkg)
826{
827 u64 route = tb_cfg_get_route(header: pkg->buffer) & ~BIT_ULL(63);
828
829 if (pkg->frame.eof == TB_CFG_PKG_ERROR)
830 return true;
831
832 if (pkg->frame.eof != req->response_type)
833 return false;
834 if (route != tb_cfg_get_route(header: req->request))
835 return false;
836 if (pkg->frame.size != req->response_size)
837 return false;
838
839 if (pkg->frame.eof == TB_CFG_PKG_READ ||
840 pkg->frame.eof == TB_CFG_PKG_WRITE) {
841 const struct cfg_read_pkg *req_hdr = req->request;
842 const struct cfg_read_pkg *res_hdr = pkg->buffer;
843
844 if (req_hdr->addr.seq != res_hdr->addr.seq)
845 return false;
846 }
847
848 return true;
849}
850
851static bool tb_cfg_copy(struct tb_cfg_request *req, const struct ctl_pkg *pkg)
852{
853 struct tb_cfg_result res;
854
855 /* Now make sure it is in expected format */
856 res = parse_header(pkg, len: req->response_size, type: req->response_type,
857 route: tb_cfg_get_route(header: req->request));
858 if (!res.err)
859 memcpy(req->response, pkg->buffer, req->response_size);
860
861 req->result = res;
862
863 /* Always complete when first response is received */
864 return true;
865}
866
867/**
868 * tb_cfg_reset() - send a reset packet and wait for a response
869 * @ctl: Control channel pointer
870 * @route: Router string for the router to send reset
871 *
872 * If the switch at route is incorrectly configured then we will not receive a
873 * reply (even though the switch will reset). The caller should check for
874 * -ETIMEDOUT and attempt to reconfigure the switch.
875 */
876struct tb_cfg_result tb_cfg_reset(struct tb_ctl *ctl, u64 route)
877{
878 struct cfg_reset_pkg request = { .header = tb_cfg_make_header(route) };
879 struct tb_cfg_result res = { 0 };
880 struct tb_cfg_header reply;
881 struct tb_cfg_request *req;
882
883 req = tb_cfg_request_alloc();
884 if (!req) {
885 res.err = -ENOMEM;
886 return res;
887 }
888
889 req->match = tb_cfg_match;
890 req->copy = tb_cfg_copy;
891 req->request = &request;
892 req->request_size = sizeof(request);
893 req->request_type = TB_CFG_PKG_RESET;
894 req->response = &reply;
895 req->response_size = sizeof(reply);
896 req->response_type = TB_CFG_PKG_RESET;
897
898 res = tb_cfg_request_sync(ctl, req, timeout_msec: ctl->timeout_msec);
899
900 tb_cfg_request_put(req);
901
902 return res;
903}
904
905/**
906 * tb_cfg_read_raw() - read from config space into buffer
907 * @ctl: Pointer to the control channel
908 * @buffer: Buffer where the data is read
909 * @route: Route string of the router
910 * @port: Port number when reading from %TB_CFG_PORT, %0 otherwise
911 * @space: Config space selector
912 * @offset: Dword word offset of the register to start reading
913 * @length: Number of dwords to read
914 * @timeout_msec: Timeout in ms how long to wait for the response
915 *
916 * Reads from router config space without translating the possible error.
917 */
918struct tb_cfg_result tb_cfg_read_raw(struct tb_ctl *ctl, void *buffer,
919 u64 route, u32 port, enum tb_cfg_space space,
920 u32 offset, u32 length, int timeout_msec)
921{
922 struct tb_cfg_result res = { 0 };
923 struct cfg_read_pkg request = {
924 .header = tb_cfg_make_header(route),
925 .addr = {
926 .port = port,
927 .space = space,
928 .offset = offset,
929 .length = length,
930 },
931 };
932 struct cfg_write_pkg reply;
933 int retries = 0;
934
935 while (retries < TB_CTL_RETRIES) {
936 struct tb_cfg_request *req;
937
938 req = tb_cfg_request_alloc();
939 if (!req) {
940 res.err = -ENOMEM;
941 return res;
942 }
943
944 request.addr.seq = retries++;
945
946 req->match = tb_cfg_match;
947 req->copy = tb_cfg_copy;
948 req->request = &request;
949 req->request_size = sizeof(request);
950 req->request_type = TB_CFG_PKG_READ;
951 req->response = &reply;
952 req->response_size = 12 + 4 * length;
953 req->response_type = TB_CFG_PKG_READ;
954
955 res = tb_cfg_request_sync(ctl, req, timeout_msec);
956
957 tb_cfg_request_put(req);
958
959 if (res.err != -ETIMEDOUT)
960 break;
961
962 /* Wait a bit (arbitrary time) until we send a retry */
963 usleep_range(min: 10, max: 100);
964 }
965
966 if (res.err)
967 return res;
968
969 res.response_port = reply.addr.port;
970 res.err = check_config_address(addr: reply.addr, space, offset, length);
971 if (!res.err)
972 memcpy(buffer, &reply.data, 4 * length);
973 return res;
974}
975
976/**
977 * tb_cfg_write_raw() - write from buffer into config space
978 * @ctl: Pointer to the control channel
979 * @buffer: Data to write
980 * @route: Route string of the router
981 * @port: Port number when writing to %TB_CFG_PORT, %0 otherwise
982 * @space: Config space selector
983 * @offset: Dword word offset of the register to start writing
984 * @length: Number of dwords to write
985 * @timeout_msec: Timeout in ms how long to wait for the response
986 *
987 * Writes to router config space without translating the possible error.
988 */
989struct tb_cfg_result tb_cfg_write_raw(struct tb_ctl *ctl, const void *buffer,
990 u64 route, u32 port, enum tb_cfg_space space,
991 u32 offset, u32 length, int timeout_msec)
992{
993 struct tb_cfg_result res = { 0 };
994 struct cfg_write_pkg request = {
995 .header = tb_cfg_make_header(route),
996 .addr = {
997 .port = port,
998 .space = space,
999 .offset = offset,
1000 .length = length,
1001 },
1002 };
1003 struct cfg_read_pkg reply;
1004 int retries = 0;
1005
1006 memcpy(&request.data, buffer, length * 4);
1007
1008 while (retries < TB_CTL_RETRIES) {
1009 struct tb_cfg_request *req;
1010
1011 req = tb_cfg_request_alloc();
1012 if (!req) {
1013 res.err = -ENOMEM;
1014 return res;
1015 }
1016
1017 request.addr.seq = retries++;
1018
1019 req->match = tb_cfg_match;
1020 req->copy = tb_cfg_copy;
1021 req->request = &request;
1022 req->request_size = 12 + 4 * length;
1023 req->request_type = TB_CFG_PKG_WRITE;
1024 req->response = &reply;
1025 req->response_size = sizeof(reply);
1026 req->response_type = TB_CFG_PKG_WRITE;
1027
1028 res = tb_cfg_request_sync(ctl, req, timeout_msec);
1029
1030 tb_cfg_request_put(req);
1031
1032 if (res.err != -ETIMEDOUT)
1033 break;
1034
1035 /* Wait a bit (arbitrary time) until we send a retry */
1036 usleep_range(min: 10, max: 100);
1037 }
1038
1039 if (res.err)
1040 return res;
1041
1042 res.response_port = reply.addr.port;
1043 res.err = check_config_address(addr: reply.addr, space, offset, length);
1044 return res;
1045}
1046
1047static int tb_cfg_get_error(struct tb_ctl *ctl, enum tb_cfg_space space,
1048 const struct tb_cfg_result *res)
1049{
1050 /*
1051 * For unimplemented ports access to port config space may return
1052 * TB_CFG_ERROR_INVALID_CONFIG_SPACE (alternatively their type is
1053 * set to TB_TYPE_INACTIVE). In the former case return -ENODEV so
1054 * that the caller can mark the port as disabled.
1055 */
1056 if (space == TB_CFG_PORT &&
1057 res->tb_error == TB_CFG_ERROR_INVALID_CONFIG_SPACE)
1058 return -ENODEV;
1059
1060 tb_cfg_print_error(ctl, res);
1061
1062 if (res->tb_error == TB_CFG_ERROR_LOCK)
1063 return -EACCES;
1064 if (res->tb_error == TB_CFG_ERROR_PORT_NOT_CONNECTED)
1065 return -ENOTCONN;
1066
1067 return -EIO;
1068}
1069
1070int tb_cfg_read(struct tb_ctl *ctl, void *buffer, u64 route, u32 port,
1071 enum tb_cfg_space space, u32 offset, u32 length)
1072{
1073 struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer, route, port,
1074 space, offset, length, timeout_msec: ctl->timeout_msec);
1075 switch (res.err) {
1076 case 0:
1077 /* Success */
1078 break;
1079
1080 case 1:
1081 /* Thunderbolt error, tb_error holds the actual number */
1082 return tb_cfg_get_error(ctl, space, res: &res);
1083
1084 case -ETIMEDOUT:
1085 tb_ctl_warn(ctl, "%llx: timeout reading config space %u from %#x\n",
1086 route, space, offset);
1087 break;
1088
1089 default:
1090 WARN(1, "tb_cfg_read: %d\n", res.err);
1091 break;
1092 }
1093 return res.err;
1094}
1095
1096int tb_cfg_write(struct tb_ctl *ctl, const void *buffer, u64 route, u32 port,
1097 enum tb_cfg_space space, u32 offset, u32 length)
1098{
1099 struct tb_cfg_result res = tb_cfg_write_raw(ctl, buffer, route, port,
1100 space, offset, length, timeout_msec: ctl->timeout_msec);
1101 switch (res.err) {
1102 case 0:
1103 /* Success */
1104 break;
1105
1106 case 1:
1107 /* Thunderbolt error, tb_error holds the actual number */
1108 return tb_cfg_get_error(ctl, space, res: &res);
1109
1110 case -ETIMEDOUT:
1111 tb_ctl_warn(ctl, "%llx: timeout writing config space %u to %#x\n",
1112 route, space, offset);
1113 break;
1114
1115 default:
1116 WARN(1, "tb_cfg_write: %d\n", res.err);
1117 break;
1118 }
1119 return res.err;
1120}
1121
1122/**
1123 * tb_cfg_get_upstream_port() - get upstream port number of switch at route
1124 * @ctl: Pointer to the control channel
1125 * @route: Route string of the router
1126 *
1127 * Reads the first dword from the switches TB_CFG_SWITCH config area and
1128 * returns the port number from which the reply originated.
1129 *
1130 * Return: Returns the upstream port number on success or an error code on
1131 * failure.
1132 */
1133int tb_cfg_get_upstream_port(struct tb_ctl *ctl, u64 route)
1134{
1135 u32 dummy;
1136 struct tb_cfg_result res = tb_cfg_read_raw(ctl, buffer: &dummy, route, port: 0,
1137 space: TB_CFG_SWITCH, offset: 0, length: 1,
1138 timeout_msec: ctl->timeout_msec);
1139 if (res.err == 1)
1140 return -EIO;
1141 if (res.err)
1142 return res.err;
1143 return res.response_port;
1144}
1145

source code of linux/drivers/thunderbolt/ctl.c