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1/*
2 * Copyright © 2014 Red Hat
3 *
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
13 *
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20 * OF THIS SOFTWARE.
21 */
22
23#include <linux/delay.h>
24#include <linux/errno.h>
25#include <linux/i2c.h>
26#include <linux/init.h>
27#include <linux/kernel.h>
28#include <linux/sched.h>
29#include <linux/seq_file.h>
30#include <linux/iopoll.h>
31
32#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
33#include <linux/stacktrace.h>
34#include <linux/sort.h>
35#include <linux/timekeeping.h>
36#include <linux/math64.h>
37#endif
38
39#include <drm/drm_atomic.h>
40#include <drm/drm_atomic_helper.h>
41#include <drm/drm_dp_mst_helper.h>
42#include <drm/drm_drv.h>
43#include <drm/drm_print.h>
44#include <drm/drm_probe_helper.h>
45
46#include "drm_crtc_helper_internal.h"
47#include "drm_dp_mst_topology_internal.h"
48
49/**
50 * DOC: dp mst helper
51 *
52 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
53 * protocol. The helpers contain a topology manager and bandwidth manager.
54 * The helpers encapsulate the sending and received of sideband msgs.
55 */
56struct drm_dp_pending_up_req {
57 struct drm_dp_sideband_msg_hdr hdr;
58 struct drm_dp_sideband_msg_req_body msg;
59 struct list_head next;
60};
61
62static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
63 char *buf);
64
65static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
66
67static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
68 int id,
69 struct drm_dp_payload *payload);
70
71static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
72 struct drm_dp_mst_port *port,
73 int offset, int size, u8 *bytes);
74static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
75 struct drm_dp_mst_port *port,
76 int offset, int size, u8 *bytes);
77
78static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
79 struct drm_dp_mst_branch *mstb);
80
81static void
82drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
83 struct drm_dp_mst_branch *mstb);
84
85static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
86 struct drm_dp_mst_branch *mstb,
87 struct drm_dp_mst_port *port);
88static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
89 u8 *guid);
90
91static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port);
92static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port);
93static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
94
95#define DBG_PREFIX "[dp_mst]"
96
97#define DP_STR(x) [DP_ ## x] = #x
98
99static const char *drm_dp_mst_req_type_str(u8 req_type)
100{
101 static const char * const req_type_str[] = {
102 DP_STR(GET_MSG_TRANSACTION_VERSION),
103 DP_STR(LINK_ADDRESS),
104 DP_STR(CONNECTION_STATUS_NOTIFY),
105 DP_STR(ENUM_PATH_RESOURCES),
106 DP_STR(ALLOCATE_PAYLOAD),
107 DP_STR(QUERY_PAYLOAD),
108 DP_STR(RESOURCE_STATUS_NOTIFY),
109 DP_STR(CLEAR_PAYLOAD_ID_TABLE),
110 DP_STR(REMOTE_DPCD_READ),
111 DP_STR(REMOTE_DPCD_WRITE),
112 DP_STR(REMOTE_I2C_READ),
113 DP_STR(REMOTE_I2C_WRITE),
114 DP_STR(POWER_UP_PHY),
115 DP_STR(POWER_DOWN_PHY),
116 DP_STR(SINK_EVENT_NOTIFY),
117 DP_STR(QUERY_STREAM_ENC_STATUS),
118 };
119
120 if (req_type >= ARRAY_SIZE(req_type_str) ||
121 !req_type_str[req_type])
122 return "unknown";
123
124 return req_type_str[req_type];
125}
126
127#undef DP_STR
128#define DP_STR(x) [DP_NAK_ ## x] = #x
129
130static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
131{
132 static const char * const nak_reason_str[] = {
133 DP_STR(WRITE_FAILURE),
134 DP_STR(INVALID_READ),
135 DP_STR(CRC_FAILURE),
136 DP_STR(BAD_PARAM),
137 DP_STR(DEFER),
138 DP_STR(LINK_FAILURE),
139 DP_STR(NO_RESOURCES),
140 DP_STR(DPCD_FAIL),
141 DP_STR(I2C_NAK),
142 DP_STR(ALLOCATE_FAIL),
143 };
144
145 if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
146 !nak_reason_str[nak_reason])
147 return "unknown";
148
149 return nak_reason_str[nak_reason];
150}
151
152#undef DP_STR
153#define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x
154
155static const char *drm_dp_mst_sideband_tx_state_str(int state)
156{
157 static const char * const sideband_reason_str[] = {
158 DP_STR(QUEUED),
159 DP_STR(START_SEND),
160 DP_STR(SENT),
161 DP_STR(RX),
162 DP_STR(TIMEOUT),
163 };
164
165 if (state >= ARRAY_SIZE(sideband_reason_str) ||
166 !sideband_reason_str[state])
167 return "unknown";
168
169 return sideband_reason_str[state];
170}
171
172static int
173drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len)
174{
175 int i;
176 u8 unpacked_rad[16];
177
178 for (i = 0; i < lct; i++) {
179 if (i % 2)
180 unpacked_rad[i] = rad[i / 2] >> 4;
181 else
182 unpacked_rad[i] = rad[i / 2] & BIT_MASK(4);
183 }
184
185 /* TODO: Eventually add something to printk so we can format the rad
186 * like this: 1.2.3
187 */
188 return snprintf(out, len, "%*phC", lct, unpacked_rad);
189}
190
191/* sideband msg handling */
192static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
193{
194 u8 bitmask = 0x80;
195 u8 bitshift = 7;
196 u8 array_index = 0;
197 int number_of_bits = num_nibbles * 4;
198 u8 remainder = 0;
199
200 while (number_of_bits != 0) {
201 number_of_bits--;
202 remainder <<= 1;
203 remainder |= (data[array_index] & bitmask) >> bitshift;
204 bitmask >>= 1;
205 bitshift--;
206 if (bitmask == 0) {
207 bitmask = 0x80;
208 bitshift = 7;
209 array_index++;
210 }
211 if ((remainder & 0x10) == 0x10)
212 remainder ^= 0x13;
213 }
214
215 number_of_bits = 4;
216 while (number_of_bits != 0) {
217 number_of_bits--;
218 remainder <<= 1;
219 if ((remainder & 0x10) != 0)
220 remainder ^= 0x13;
221 }
222
223 return remainder;
224}
225
226static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
227{
228 u8 bitmask = 0x80;
229 u8 bitshift = 7;
230 u8 array_index = 0;
231 int number_of_bits = number_of_bytes * 8;
232 u16 remainder = 0;
233
234 while (number_of_bits != 0) {
235 number_of_bits--;
236 remainder <<= 1;
237 remainder |= (data[array_index] & bitmask) >> bitshift;
238 bitmask >>= 1;
239 bitshift--;
240 if (bitmask == 0) {
241 bitmask = 0x80;
242 bitshift = 7;
243 array_index++;
244 }
245 if ((remainder & 0x100) == 0x100)
246 remainder ^= 0xd5;
247 }
248
249 number_of_bits = 8;
250 while (number_of_bits != 0) {
251 number_of_bits--;
252 remainder <<= 1;
253 if ((remainder & 0x100) != 0)
254 remainder ^= 0xd5;
255 }
256
257 return remainder & 0xff;
258}
259static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
260{
261 u8 size = 3;
262
263 size += (hdr->lct / 2);
264 return size;
265}
266
267static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
268 u8 *buf, int *len)
269{
270 int idx = 0;
271 int i;
272 u8 crc4;
273
274 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
275 for (i = 0; i < (hdr->lct / 2); i++)
276 buf[idx++] = hdr->rad[i];
277 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
278 (hdr->msg_len & 0x3f);
279 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
280
281 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
282 buf[idx - 1] |= (crc4 & 0xf);
283
284 *len = idx;
285}
286
287static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
288 u8 *buf, int buflen, u8 *hdrlen)
289{
290 u8 crc4;
291 u8 len;
292 int i;
293 u8 idx;
294
295 if (buf[0] == 0)
296 return false;
297 len = 3;
298 len += ((buf[0] & 0xf0) >> 4) / 2;
299 if (len > buflen)
300 return false;
301 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
302
303 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
304 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
305 return false;
306 }
307
308 hdr->lct = (buf[0] & 0xf0) >> 4;
309 hdr->lcr = (buf[0] & 0xf);
310 idx = 1;
311 for (i = 0; i < (hdr->lct / 2); i++)
312 hdr->rad[i] = buf[idx++];
313 hdr->broadcast = (buf[idx] >> 7) & 0x1;
314 hdr->path_msg = (buf[idx] >> 6) & 0x1;
315 hdr->msg_len = buf[idx] & 0x3f;
316 idx++;
317 hdr->somt = (buf[idx] >> 7) & 0x1;
318 hdr->eomt = (buf[idx] >> 6) & 0x1;
319 hdr->seqno = (buf[idx] >> 4) & 0x1;
320 idx++;
321 *hdrlen = idx;
322 return true;
323}
324
325void
326drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
327 struct drm_dp_sideband_msg_tx *raw)
328{
329 int idx = 0;
330 int i;
331 u8 *buf = raw->msg;
332
333 buf[idx++] = req->req_type & 0x7f;
334
335 switch (req->req_type) {
336 case DP_ENUM_PATH_RESOURCES:
337 case DP_POWER_DOWN_PHY:
338 case DP_POWER_UP_PHY:
339 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
340 idx++;
341 break;
342 case DP_ALLOCATE_PAYLOAD:
343 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
344 (req->u.allocate_payload.number_sdp_streams & 0xf);
345 idx++;
346 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
347 idx++;
348 buf[idx] = (req->u.allocate_payload.pbn >> 8);
349 idx++;
350 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
351 idx++;
352 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
353 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
354 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
355 idx++;
356 }
357 if (req->u.allocate_payload.number_sdp_streams & 1) {
358 i = req->u.allocate_payload.number_sdp_streams - 1;
359 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
360 idx++;
361 }
362 break;
363 case DP_QUERY_PAYLOAD:
364 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
365 idx++;
366 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
367 idx++;
368 break;
369 case DP_REMOTE_DPCD_READ:
370 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
371 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
372 idx++;
373 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
374 idx++;
375 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
376 idx++;
377 buf[idx] = (req->u.dpcd_read.num_bytes);
378 idx++;
379 break;
380
381 case DP_REMOTE_DPCD_WRITE:
382 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
383 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
384 idx++;
385 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
386 idx++;
387 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
388 idx++;
389 buf[idx] = (req->u.dpcd_write.num_bytes);
390 idx++;
391 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
392 idx += req->u.dpcd_write.num_bytes;
393 break;
394 case DP_REMOTE_I2C_READ:
395 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
396 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
397 idx++;
398 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
399 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
400 idx++;
401 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
402 idx++;
403 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
404 idx += req->u.i2c_read.transactions[i].num_bytes;
405
406 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
407 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
408 idx++;
409 }
410 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
411 idx++;
412 buf[idx] = (req->u.i2c_read.num_bytes_read);
413 idx++;
414 break;
415
416 case DP_REMOTE_I2C_WRITE:
417 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
418 idx++;
419 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
420 idx++;
421 buf[idx] = (req->u.i2c_write.num_bytes);
422 idx++;
423 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
424 idx += req->u.i2c_write.num_bytes;
425 break;
426 }
427 raw->cur_len = idx;
428}
429EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req);
430
431/* Decode a sideband request we've encoded, mainly used for debugging */
432int
433drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
434 struct drm_dp_sideband_msg_req_body *req)
435{
436 const u8 *buf = raw->msg;
437 int i, idx = 0;
438
439 req->req_type = buf[idx++] & 0x7f;
440 switch (req->req_type) {
441 case DP_ENUM_PATH_RESOURCES:
442 case DP_POWER_DOWN_PHY:
443 case DP_POWER_UP_PHY:
444 req->u.port_num.port_number = (buf[idx] >> 4) & 0xf;
445 break;
446 case DP_ALLOCATE_PAYLOAD:
447 {
448 struct drm_dp_allocate_payload *a =
449 &req->u.allocate_payload;
450
451 a->number_sdp_streams = buf[idx] & 0xf;
452 a->port_number = (buf[idx] >> 4) & 0xf;
453
454 WARN_ON(buf[++idx] & 0x80);
455 a->vcpi = buf[idx] & 0x7f;
456
457 a->pbn = buf[++idx] << 8;
458 a->pbn |= buf[++idx];
459
460 idx++;
461 for (i = 0; i < a->number_sdp_streams; i++) {
462 a->sdp_stream_sink[i] =
463 (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf;
464 }
465 }
466 break;
467 case DP_QUERY_PAYLOAD:
468 req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf;
469 WARN_ON(buf[++idx] & 0x80);
470 req->u.query_payload.vcpi = buf[idx] & 0x7f;
471 break;
472 case DP_REMOTE_DPCD_READ:
473 {
474 struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read;
475
476 r->port_number = (buf[idx] >> 4) & 0xf;
477
478 r->dpcd_address = (buf[idx] << 16) & 0xf0000;
479 r->dpcd_address |= (buf[++idx] << 8) & 0xff00;
480 r->dpcd_address |= buf[++idx] & 0xff;
481
482 r->num_bytes = buf[++idx];
483 }
484 break;
485 case DP_REMOTE_DPCD_WRITE:
486 {
487 struct drm_dp_remote_dpcd_write *w =
488 &req->u.dpcd_write;
489
490 w->port_number = (buf[idx] >> 4) & 0xf;
491
492 w->dpcd_address = (buf[idx] << 16) & 0xf0000;
493 w->dpcd_address |= (buf[++idx] << 8) & 0xff00;
494 w->dpcd_address |= buf[++idx] & 0xff;
495
496 w->num_bytes = buf[++idx];
497
498 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
499 GFP_KERNEL);
500 if (!w->bytes)
501 return -ENOMEM;
502 }
503 break;
504 case DP_REMOTE_I2C_READ:
505 {
506 struct drm_dp_remote_i2c_read *r = &req->u.i2c_read;
507 struct drm_dp_remote_i2c_read_tx *tx;
508 bool failed = false;
509
510 r->num_transactions = buf[idx] & 0x3;
511 r->port_number = (buf[idx] >> 4) & 0xf;
512 for (i = 0; i < r->num_transactions; i++) {
513 tx = &r->transactions[i];
514
515 tx->i2c_dev_id = buf[++idx] & 0x7f;
516 tx->num_bytes = buf[++idx];
517 tx->bytes = kmemdup(&buf[++idx],
518 tx->num_bytes,
519 GFP_KERNEL);
520 if (!tx->bytes) {
521 failed = true;
522 break;
523 }
524 idx += tx->num_bytes;
525 tx->no_stop_bit = (buf[idx] >> 5) & 0x1;
526 tx->i2c_transaction_delay = buf[idx] & 0xf;
527 }
528
529 if (failed) {
530 for (i = 0; i < r->num_transactions; i++) {
531 tx = &r->transactions[i];
532 kfree(tx->bytes);
533 }
534 return -ENOMEM;
535 }
536
537 r->read_i2c_device_id = buf[++idx] & 0x7f;
538 r->num_bytes_read = buf[++idx];
539 }
540 break;
541 case DP_REMOTE_I2C_WRITE:
542 {
543 struct drm_dp_remote_i2c_write *w = &req->u.i2c_write;
544
545 w->port_number = (buf[idx] >> 4) & 0xf;
546 w->write_i2c_device_id = buf[++idx] & 0x7f;
547 w->num_bytes = buf[++idx];
548 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
549 GFP_KERNEL);
550 if (!w->bytes)
551 return -ENOMEM;
552 }
553 break;
554 }
555
556 return 0;
557}
558EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req);
559
560void
561drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req,
562 int indent, struct drm_printer *printer)
563{
564 int i;
565
566#define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__)
567 if (req->req_type == DP_LINK_ADDRESS) {
568 /* No contents to print */
569 P("type=%s\n", drm_dp_mst_req_type_str(req->req_type));
570 return;
571 }
572
573 P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type));
574 indent++;
575
576 switch (req->req_type) {
577 case DP_ENUM_PATH_RESOURCES:
578 case DP_POWER_DOWN_PHY:
579 case DP_POWER_UP_PHY:
580 P("port=%d\n", req->u.port_num.port_number);
581 break;
582 case DP_ALLOCATE_PAYLOAD:
583 P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n",
584 req->u.allocate_payload.port_number,
585 req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn,
586 req->u.allocate_payload.number_sdp_streams,
587 req->u.allocate_payload.number_sdp_streams,
588 req->u.allocate_payload.sdp_stream_sink);
589 break;
590 case DP_QUERY_PAYLOAD:
591 P("port=%d vcpi=%d\n",
592 req->u.query_payload.port_number,
593 req->u.query_payload.vcpi);
594 break;
595 case DP_REMOTE_DPCD_READ:
596 P("port=%d dpcd_addr=%05x len=%d\n",
597 req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address,
598 req->u.dpcd_read.num_bytes);
599 break;
600 case DP_REMOTE_DPCD_WRITE:
601 P("port=%d addr=%05x len=%d: %*ph\n",
602 req->u.dpcd_write.port_number,
603 req->u.dpcd_write.dpcd_address,
604 req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes,
605 req->u.dpcd_write.bytes);
606 break;
607 case DP_REMOTE_I2C_READ:
608 P("port=%d num_tx=%d id=%d size=%d:\n",
609 req->u.i2c_read.port_number,
610 req->u.i2c_read.num_transactions,
611 req->u.i2c_read.read_i2c_device_id,
612 req->u.i2c_read.num_bytes_read);
613
614 indent++;
615 for (i = 0; i < req->u.i2c_read.num_transactions; i++) {
616 const struct drm_dp_remote_i2c_read_tx *rtx =
617 &req->u.i2c_read.transactions[i];
618
619 P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n",
620 i, rtx->i2c_dev_id, rtx->num_bytes,
621 rtx->no_stop_bit, rtx->i2c_transaction_delay,
622 rtx->num_bytes, rtx->bytes);
623 }
624 break;
625 case DP_REMOTE_I2C_WRITE:
626 P("port=%d id=%d size=%d: %*ph\n",
627 req->u.i2c_write.port_number,
628 req->u.i2c_write.write_i2c_device_id,
629 req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes,
630 req->u.i2c_write.bytes);
631 break;
632 default:
633 P("???\n");
634 break;
635 }
636#undef P
637}
638EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body);
639
640static inline void
641drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p,
642 const struct drm_dp_sideband_msg_tx *txmsg)
643{
644 struct drm_dp_sideband_msg_req_body req;
645 char buf[64];
646 int ret;
647 int i;
648
649 drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf,
650 sizeof(buf));
651 drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n",
652 txmsg->cur_offset, txmsg->cur_len, txmsg->seqno,
653 drm_dp_mst_sideband_tx_state_str(txmsg->state),
654 txmsg->path_msg, buf);
655
656 ret = drm_dp_decode_sideband_req(txmsg, &req);
657 if (ret) {
658 drm_printf(p, "<failed to decode sideband req: %d>\n", ret);
659 return;
660 }
661 drm_dp_dump_sideband_msg_req_body(&req, 1, p);
662
663 switch (req.req_type) {
664 case DP_REMOTE_DPCD_WRITE:
665 kfree(req.u.dpcd_write.bytes);
666 break;
667 case DP_REMOTE_I2C_READ:
668 for (i = 0; i < req.u.i2c_read.num_transactions; i++)
669 kfree(req.u.i2c_read.transactions[i].bytes);
670 break;
671 case DP_REMOTE_I2C_WRITE:
672 kfree(req.u.i2c_write.bytes);
673 break;
674 }
675}
676
677static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
678{
679 u8 crc4;
680
681 crc4 = drm_dp_msg_data_crc4(msg, len);
682 msg[len] = crc4;
683}
684
685static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
686 struct drm_dp_sideband_msg_tx *raw)
687{
688 int idx = 0;
689 u8 *buf = raw->msg;
690
691 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
692
693 raw->cur_len = idx;
694}
695
696static int drm_dp_sideband_msg_set_header(struct drm_dp_sideband_msg_rx *msg,
697 struct drm_dp_sideband_msg_hdr *hdr,
698 u8 hdrlen)
699{
700 /*
701 * ignore out-of-order messages or messages that are part of a
702 * failed transaction
703 */
704 if (!hdr->somt && !msg->have_somt)
705 return false;
706
707 /* get length contained in this portion */
708 msg->curchunk_idx = 0;
709 msg->curchunk_len = hdr->msg_len;
710 msg->curchunk_hdrlen = hdrlen;
711
712 /* we have already gotten an somt - don't bother parsing */
713 if (hdr->somt && msg->have_somt)
714 return false;
715
716 if (hdr->somt) {
717 memcpy(&msg->initial_hdr, hdr,
718 sizeof(struct drm_dp_sideband_msg_hdr));
719 msg->have_somt = true;
720 }
721 if (hdr->eomt)
722 msg->have_eomt = true;
723
724 return true;
725}
726
727/* this adds a chunk of msg to the builder to get the final msg */
728static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx *msg,
729 u8 *replybuf, u8 replybuflen)
730{
731 u8 crc4;
732
733 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
734 msg->curchunk_idx += replybuflen;
735
736 if (msg->curchunk_idx >= msg->curchunk_len) {
737 /* do CRC */
738 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
739 if (crc4 != msg->chunk[msg->curchunk_len - 1])
740 print_hex_dump(KERN_DEBUG, "wrong crc",
741 DUMP_PREFIX_NONE, 16, 1,
742 msg->chunk, msg->curchunk_len, false);
743 /* copy chunk into bigger msg */
744 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
745 msg->curlen += msg->curchunk_len - 1;
746 }
747 return true;
748}
749
750static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
751 struct drm_dp_sideband_msg_reply_body *repmsg)
752{
753 int idx = 1;
754 int i;
755
756 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
757 idx += 16;
758 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
759 idx++;
760 if (idx > raw->curlen)
761 goto fail_len;
762 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
763 if (raw->msg[idx] & 0x80)
764 repmsg->u.link_addr.ports[i].input_port = 1;
765
766 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
767 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
768
769 idx++;
770 if (idx > raw->curlen)
771 goto fail_len;
772 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
773 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
774 if (repmsg->u.link_addr.ports[i].input_port == 0)
775 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
776 idx++;
777 if (idx > raw->curlen)
778 goto fail_len;
779 if (repmsg->u.link_addr.ports[i].input_port == 0) {
780 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
781 idx++;
782 if (idx > raw->curlen)
783 goto fail_len;
784 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
785 idx += 16;
786 if (idx > raw->curlen)
787 goto fail_len;
788 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
789 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
790 idx++;
791
792 }
793 if (idx > raw->curlen)
794 goto fail_len;
795 }
796
797 return true;
798fail_len:
799 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
800 return false;
801}
802
803static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
804 struct drm_dp_sideband_msg_reply_body *repmsg)
805{
806 int idx = 1;
807
808 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
809 idx++;
810 if (idx > raw->curlen)
811 goto fail_len;
812 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
813 idx++;
814 if (idx > raw->curlen)
815 goto fail_len;
816
817 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
818 return true;
819fail_len:
820 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
821 return false;
822}
823
824static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
825 struct drm_dp_sideband_msg_reply_body *repmsg)
826{
827 int idx = 1;
828
829 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
830 idx++;
831 if (idx > raw->curlen)
832 goto fail_len;
833 return true;
834fail_len:
835 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
836 return false;
837}
838
839static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
840 struct drm_dp_sideband_msg_reply_body *repmsg)
841{
842 int idx = 1;
843
844 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
845 idx++;
846 if (idx > raw->curlen)
847 goto fail_len;
848 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
849 idx++;
850 /* TODO check */
851 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
852 return true;
853fail_len:
854 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
855 return false;
856}
857
858static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
859 struct drm_dp_sideband_msg_reply_body *repmsg)
860{
861 int idx = 1;
862
863 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
864 repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1;
865 idx++;
866 if (idx > raw->curlen)
867 goto fail_len;
868 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
869 idx += 2;
870 if (idx > raw->curlen)
871 goto fail_len;
872 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
873 idx += 2;
874 if (idx > raw->curlen)
875 goto fail_len;
876 return true;
877fail_len:
878 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
879 return false;
880}
881
882static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
883 struct drm_dp_sideband_msg_reply_body *repmsg)
884{
885 int idx = 1;
886
887 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
888 idx++;
889 if (idx > raw->curlen)
890 goto fail_len;
891 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
892 idx++;
893 if (idx > raw->curlen)
894 goto fail_len;
895 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
896 idx += 2;
897 if (idx > raw->curlen)
898 goto fail_len;
899 return true;
900fail_len:
901 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
902 return false;
903}
904
905static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
906 struct drm_dp_sideband_msg_reply_body *repmsg)
907{
908 int idx = 1;
909
910 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
911 idx++;
912 if (idx > raw->curlen)
913 goto fail_len;
914 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
915 idx += 2;
916 if (idx > raw->curlen)
917 goto fail_len;
918 return true;
919fail_len:
920 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
921 return false;
922}
923
924static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
925 struct drm_dp_sideband_msg_reply_body *repmsg)
926{
927 int idx = 1;
928
929 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
930 idx++;
931 if (idx > raw->curlen) {
932 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
933 idx, raw->curlen);
934 return false;
935 }
936 return true;
937}
938
939static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
940 struct drm_dp_sideband_msg_reply_body *msg)
941{
942 memset(msg, 0, sizeof(*msg));
943 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
944 msg->req_type = (raw->msg[0] & 0x7f);
945
946 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
947 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
948 msg->u.nak.reason = raw->msg[17];
949 msg->u.nak.nak_data = raw->msg[18];
950 return false;
951 }
952
953 switch (msg->req_type) {
954 case DP_LINK_ADDRESS:
955 return drm_dp_sideband_parse_link_address(raw, msg);
956 case DP_QUERY_PAYLOAD:
957 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
958 case DP_REMOTE_DPCD_READ:
959 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
960 case DP_REMOTE_DPCD_WRITE:
961 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
962 case DP_REMOTE_I2C_READ:
963 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
964 case DP_ENUM_PATH_RESOURCES:
965 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
966 case DP_ALLOCATE_PAYLOAD:
967 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
968 case DP_POWER_DOWN_PHY:
969 case DP_POWER_UP_PHY:
970 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
971 case DP_CLEAR_PAYLOAD_ID_TABLE:
972 return true; /* since there's nothing to parse */
973 default:
974 DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type,
975 drm_dp_mst_req_type_str(msg->req_type));
976 return false;
977 }
978}
979
980static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
981 struct drm_dp_sideband_msg_req_body *msg)
982{
983 int idx = 1;
984
985 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
986 idx++;
987 if (idx > raw->curlen)
988 goto fail_len;
989
990 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
991 idx += 16;
992 if (idx > raw->curlen)
993 goto fail_len;
994
995 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
996 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
997 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
998 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
999 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
1000 idx++;
1001 return true;
1002fail_len:
1003 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
1004 return false;
1005}
1006
1007static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
1008 struct drm_dp_sideband_msg_req_body *msg)
1009{
1010 int idx = 1;
1011
1012 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
1013 idx++;
1014 if (idx > raw->curlen)
1015 goto fail_len;
1016
1017 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
1018 idx += 16;
1019 if (idx > raw->curlen)
1020 goto fail_len;
1021
1022 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
1023 idx++;
1024 return true;
1025fail_len:
1026 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
1027 return false;
1028}
1029
1030static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
1031 struct drm_dp_sideband_msg_req_body *msg)
1032{
1033 memset(msg, 0, sizeof(*msg));
1034 msg->req_type = (raw->msg[0] & 0x7f);
1035
1036 switch (msg->req_type) {
1037 case DP_CONNECTION_STATUS_NOTIFY:
1038 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
1039 case DP_RESOURCE_STATUS_NOTIFY:
1040 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
1041 default:
1042 DRM_ERROR("Got unknown request 0x%02x (%s)\n", msg->req_type,
1043 drm_dp_mst_req_type_str(msg->req_type));
1044 return false;
1045 }
1046}
1047
1048static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg,
1049 u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
1050{
1051 struct drm_dp_sideband_msg_req_body req;
1052
1053 req.req_type = DP_REMOTE_DPCD_WRITE;
1054 req.u.dpcd_write.port_number = port_num;
1055 req.u.dpcd_write.dpcd_address = offset;
1056 req.u.dpcd_write.num_bytes = num_bytes;
1057 req.u.dpcd_write.bytes = bytes;
1058 drm_dp_encode_sideband_req(&req, msg);
1059}
1060
1061static void build_link_address(struct drm_dp_sideband_msg_tx *msg)
1062{
1063 struct drm_dp_sideband_msg_req_body req;
1064
1065 req.req_type = DP_LINK_ADDRESS;
1066 drm_dp_encode_sideband_req(&req, msg);
1067}
1068
1069static void build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
1070{
1071 struct drm_dp_sideband_msg_req_body req;
1072
1073 req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE;
1074 drm_dp_encode_sideband_req(&req, msg);
1075}
1076
1077static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg,
1078 int port_num)
1079{
1080 struct drm_dp_sideband_msg_req_body req;
1081
1082 req.req_type = DP_ENUM_PATH_RESOURCES;
1083 req.u.port_num.port_number = port_num;
1084 drm_dp_encode_sideband_req(&req, msg);
1085 msg->path_msg = true;
1086 return 0;
1087}
1088
1089static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg,
1090 int port_num,
1091 u8 vcpi, uint16_t pbn,
1092 u8 number_sdp_streams,
1093 u8 *sdp_stream_sink)
1094{
1095 struct drm_dp_sideband_msg_req_body req;
1096
1097 memset(&req, 0, sizeof(req));
1098 req.req_type = DP_ALLOCATE_PAYLOAD;
1099 req.u.allocate_payload.port_number = port_num;
1100 req.u.allocate_payload.vcpi = vcpi;
1101 req.u.allocate_payload.pbn = pbn;
1102 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
1103 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
1104 number_sdp_streams);
1105 drm_dp_encode_sideband_req(&req, msg);
1106 msg->path_msg = true;
1107}
1108
1109static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
1110 int port_num, bool power_up)
1111{
1112 struct drm_dp_sideband_msg_req_body req;
1113
1114 if (power_up)
1115 req.req_type = DP_POWER_UP_PHY;
1116 else
1117 req.req_type = DP_POWER_DOWN_PHY;
1118
1119 req.u.port_num.port_number = port_num;
1120 drm_dp_encode_sideband_req(&req, msg);
1121 msg->path_msg = true;
1122}
1123
1124static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1125 struct drm_dp_vcpi *vcpi)
1126{
1127 int ret, vcpi_ret;
1128
1129 mutex_lock(&mgr->payload_lock);
1130 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
1131 if (ret > mgr->max_payloads) {
1132 ret = -EINVAL;
1133 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
1134 goto out_unlock;
1135 }
1136
1137 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
1138 if (vcpi_ret > mgr->max_payloads) {
1139 ret = -EINVAL;
1140 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
1141 goto out_unlock;
1142 }
1143
1144 set_bit(ret, &mgr->payload_mask);
1145 set_bit(vcpi_ret, &mgr->vcpi_mask);
1146 vcpi->vcpi = vcpi_ret + 1;
1147 mgr->proposed_vcpis[ret - 1] = vcpi;
1148out_unlock:
1149 mutex_unlock(&mgr->payload_lock);
1150 return ret;
1151}
1152
1153static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1154 int vcpi)
1155{
1156 int i;
1157
1158 if (vcpi == 0)
1159 return;
1160
1161 mutex_lock(&mgr->payload_lock);
1162 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
1163 clear_bit(vcpi - 1, &mgr->vcpi_mask);
1164
1165 for (i = 0; i < mgr->max_payloads; i++) {
1166 if (mgr->proposed_vcpis[i] &&
1167 mgr->proposed_vcpis[i]->vcpi == vcpi) {
1168 mgr->proposed_vcpis[i] = NULL;
1169 clear_bit(i + 1, &mgr->payload_mask);
1170 }
1171 }
1172 mutex_unlock(&mgr->payload_lock);
1173}
1174
1175static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
1176 struct drm_dp_sideband_msg_tx *txmsg)
1177{
1178 unsigned int state;
1179
1180 /*
1181 * All updates to txmsg->state are protected by mgr->qlock, and the two
1182 * cases we check here are terminal states. For those the barriers
1183 * provided by the wake_up/wait_event pair are enough.
1184 */
1185 state = READ_ONCE(txmsg->state);
1186 return (state == DRM_DP_SIDEBAND_TX_RX ||
1187 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
1188}
1189
1190static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
1191 struct drm_dp_sideband_msg_tx *txmsg)
1192{
1193 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1194 unsigned long wait_timeout = msecs_to_jiffies(4000);
1195 unsigned long wait_expires = jiffies + wait_timeout;
1196 int ret;
1197
1198 for (;;) {
1199 /*
1200 * If the driver provides a way for this, change to
1201 * poll-waiting for the MST reply interrupt if we didn't receive
1202 * it for 50 msec. This would cater for cases where the HPD
1203 * pulse signal got lost somewhere, even though the sink raised
1204 * the corresponding MST interrupt correctly. One example is the
1205 * Club 3D CAC-1557 TypeC -> DP adapter which for some reason
1206 * filters out short pulses with a duration less than ~540 usec.
1207 *
1208 * The poll period is 50 msec to avoid missing an interrupt
1209 * after the sink has cleared it (after a 110msec timeout
1210 * since it raised the interrupt).
1211 */
1212 ret = wait_event_timeout(mgr->tx_waitq,
1213 check_txmsg_state(mgr, txmsg),
1214 mgr->cbs->poll_hpd_irq ?
1215 msecs_to_jiffies(50) :
1216 wait_timeout);
1217
1218 if (ret || !mgr->cbs->poll_hpd_irq ||
1219 time_after(jiffies, wait_expires))
1220 break;
1221
1222 mgr->cbs->poll_hpd_irq(mgr);
1223 }
1224
1225 mutex_lock(&mgr->qlock);
1226 if (ret > 0) {
1227 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
1228 ret = -EIO;
1229 goto out;
1230 }
1231 } else {
1232 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
1233
1234 /* dump some state */
1235 ret = -EIO;
1236
1237 /* remove from q */
1238 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
1239 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
1240 txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
1241 list_del(&txmsg->next);
1242 }
1243out:
1244 if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
1245 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1246
1247 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
1248 }
1249 mutex_unlock(&mgr->qlock);
1250
1251 drm_dp_mst_kick_tx(mgr);
1252 return ret;
1253}
1254
1255static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
1256{
1257 struct drm_dp_mst_branch *mstb;
1258
1259 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
1260 if (!mstb)
1261 return NULL;
1262
1263 mstb->lct = lct;
1264 if (lct > 1)
1265 memcpy(mstb->rad, rad, lct / 2);
1266 INIT_LIST_HEAD(&mstb->ports);
1267 kref_init(&mstb->topology_kref);
1268 kref_init(&mstb->malloc_kref);
1269 return mstb;
1270}
1271
1272static void drm_dp_free_mst_branch_device(struct kref *kref)
1273{
1274 struct drm_dp_mst_branch *mstb =
1275 container_of(kref, struct drm_dp_mst_branch, malloc_kref);
1276
1277 if (mstb->port_parent)
1278 drm_dp_mst_put_port_malloc(mstb->port_parent);
1279
1280 kfree(mstb);
1281}
1282
1283/**
1284 * DOC: Branch device and port refcounting
1285 *
1286 * Topology refcount overview
1287 * ~~~~~~~~~~~~~~~~~~~~~~~~~~
1288 *
1289 * The refcounting schemes for &struct drm_dp_mst_branch and &struct
1290 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
1291 * two different kinds of refcounts: topology refcounts, and malloc refcounts.
1292 *
1293 * Topology refcounts are not exposed to drivers, and are handled internally
1294 * by the DP MST helpers. The helpers use them in order to prevent the
1295 * in-memory topology state from being changed in the middle of critical
1296 * operations like changing the internal state of payload allocations. This
1297 * means each branch and port will be considered to be connected to the rest
1298 * of the topology until its topology refcount reaches zero. Additionally,
1299 * for ports this means that their associated &struct drm_connector will stay
1300 * registered with userspace until the port's refcount reaches 0.
1301 *
1302 * Malloc refcount overview
1303 * ~~~~~~~~~~~~~~~~~~~~~~~~
1304 *
1305 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct
1306 * drm_dp_mst_branch allocated even after all of its topology references have
1307 * been dropped, so that the driver or MST helpers can safely access each
1308 * branch's last known state before it was disconnected from the topology.
1309 * When the malloc refcount of a port or branch reaches 0, the memory
1310 * allocation containing the &struct drm_dp_mst_branch or &struct
1311 * drm_dp_mst_port respectively will be freed.
1312 *
1313 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
1314 * to drivers. As of writing this documentation, there are no drivers that
1315 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
1316 * helpers. Exposing this API to drivers in a race-free manner would take more
1317 * tweaking of the refcounting scheme, however patches are welcome provided
1318 * there is a legitimate driver usecase for this.
1319 *
1320 * Refcount relationships in a topology
1321 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1322 *
1323 * Let's take a look at why the relationship between topology and malloc
1324 * refcounts is designed the way it is.
1325 *
1326 * .. kernel-figure:: dp-mst/topology-figure-1.dot
1327 *
1328 * An example of topology and malloc refs in a DP MST topology with two
1329 * active payloads. Topology refcount increments are indicated by solid
1330 * lines, and malloc refcount increments are indicated by dashed lines.
1331 * Each starts from the branch which incremented the refcount, and ends at
1332 * the branch to which the refcount belongs to, i.e. the arrow points the
1333 * same way as the C pointers used to reference a structure.
1334 *
1335 * As you can see in the above figure, every branch increments the topology
1336 * refcount of its children, and increments the malloc refcount of its
1337 * parent. Additionally, every payload increments the malloc refcount of its
1338 * assigned port by 1.
1339 *
1340 * So, what would happen if MSTB #3 from the above figure was unplugged from
1341 * the system, but the driver hadn't yet removed payload #2 from port #3? The
1342 * topology would start to look like the figure below.
1343 *
1344 * .. kernel-figure:: dp-mst/topology-figure-2.dot
1345 *
1346 * Ports and branch devices which have been released from memory are
1347 * colored grey, and references which have been removed are colored red.
1348 *
1349 * Whenever a port or branch device's topology refcount reaches zero, it will
1350 * decrement the topology refcounts of all its children, the malloc refcount
1351 * of its parent, and finally its own malloc refcount. For MSTB #4 and port
1352 * #4, this means they both have been disconnected from the topology and freed
1353 * from memory. But, because payload #2 is still holding a reference to port
1354 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
1355 * is still accessible from memory. This also means port #3 has not yet
1356 * decremented the malloc refcount of MSTB #3, so its &struct
1357 * drm_dp_mst_branch will also stay allocated in memory until port #3's
1358 * malloc refcount reaches 0.
1359 *
1360 * This relationship is necessary because in order to release payload #2, we
1361 * need to be able to figure out the last relative of port #3 that's still
1362 * connected to the topology. In this case, we would travel up the topology as
1363 * shown below.
1364 *
1365 * .. kernel-figure:: dp-mst/topology-figure-3.dot
1366 *
1367 * And finally, remove payload #2 by communicating with port #2 through
1368 * sideband transactions.
1369 */
1370
1371/**
1372 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
1373 * device
1374 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
1375 *
1376 * Increments &drm_dp_mst_branch.malloc_kref. When
1377 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1378 * will be released and @mstb may no longer be used.
1379 *
1380 * See also: drm_dp_mst_put_mstb_malloc()
1381 */
1382static void
1383drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
1384{
1385 kref_get(&mstb->malloc_kref);
1386 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
1387}
1388
1389/**
1390 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
1391 * device
1392 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
1393 *
1394 * Decrements &drm_dp_mst_branch.malloc_kref. When
1395 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1396 * will be released and @mstb may no longer be used.
1397 *
1398 * See also: drm_dp_mst_get_mstb_malloc()
1399 */
1400static void
1401drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
1402{
1403 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
1404 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
1405}
1406
1407static void drm_dp_free_mst_port(struct kref *kref)
1408{
1409 struct drm_dp_mst_port *port =
1410 container_of(kref, struct drm_dp_mst_port, malloc_kref);
1411
1412 drm_dp_mst_put_mstb_malloc(port->parent);
1413 kfree(port);
1414}
1415
1416/**
1417 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
1418 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of
1419 *
1420 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1421 * reaches 0, the memory allocation for @port will be released and @port may
1422 * no longer be used.
1423 *
1424 * Because @port could potentially be freed at any time by the DP MST helpers
1425 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
1426 * function, drivers that which to make use of &struct drm_dp_mst_port should
1427 * ensure that they grab at least one main malloc reference to their MST ports
1428 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
1429 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
1430 *
1431 * See also: drm_dp_mst_put_port_malloc()
1432 */
1433void
1434drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
1435{
1436 kref_get(&port->malloc_kref);
1437 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref));
1438}
1439EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
1440
1441/**
1442 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
1443 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
1444 *
1445 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1446 * reaches 0, the memory allocation for @port will be released and @port may
1447 * no longer be used.
1448 *
1449 * See also: drm_dp_mst_get_port_malloc()
1450 */
1451void
1452drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
1453{
1454 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
1455 kref_put(&port->malloc_kref, drm_dp_free_mst_port);
1456}
1457EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
1458
1459#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
1460
1461#define STACK_DEPTH 8
1462
1463static noinline void
1464__topology_ref_save(struct drm_dp_mst_topology_mgr *mgr,
1465 struct drm_dp_mst_topology_ref_history *history,
1466 enum drm_dp_mst_topology_ref_type type)
1467{
1468 struct drm_dp_mst_topology_ref_entry *entry = NULL;
1469 depot_stack_handle_t backtrace;
1470 ulong stack_entries[STACK_DEPTH];
1471 uint n;
1472 int i;
1473
1474 n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1);
1475 backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL);
1476 if (!backtrace)
1477 return;
1478
1479 /* Try to find an existing entry for this backtrace */
1480 for (i = 0; i < history->len; i++) {
1481 if (history->entries[i].backtrace == backtrace) {
1482 entry = &history->entries[i];
1483 break;
1484 }
1485 }
1486
1487 /* Otherwise add one */
1488 if (!entry) {
1489 struct drm_dp_mst_topology_ref_entry *new;
1490 int new_len = history->len + 1;
1491
1492 new = krealloc(history->entries, sizeof(*new) * new_len,
1493 GFP_KERNEL);
1494 if (!new)
1495 return;
1496
1497 entry = &new[history->len];
1498 history->len = new_len;
1499 history->entries = new;
1500
1501 entry->backtrace = backtrace;
1502 entry->type = type;
1503 entry->count = 0;
1504 }
1505 entry->count++;
1506 entry->ts_nsec = ktime_get_ns();
1507}
1508
1509static int
1510topology_ref_history_cmp(const void *a, const void *b)
1511{
1512 const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b;
1513
1514 if (entry_a->ts_nsec > entry_b->ts_nsec)
1515 return 1;
1516 else if (entry_a->ts_nsec < entry_b->ts_nsec)
1517 return -1;
1518 else
1519 return 0;
1520}
1521
1522static inline const char *
1523topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type)
1524{
1525 if (type == DRM_DP_MST_TOPOLOGY_REF_GET)
1526 return "get";
1527 else
1528 return "put";
1529}
1530
1531static void
1532__dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history,
1533 void *ptr, const char *type_str)
1534{
1535 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1536 char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1537 int i;
1538
1539 if (!buf)
1540 return;
1541
1542 if (!history->len)
1543 goto out;
1544
1545 /* First, sort the list so that it goes from oldest to newest
1546 * reference entry
1547 */
1548 sort(history->entries, history->len, sizeof(*history->entries),
1549 topology_ref_history_cmp, NULL);
1550
1551 drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n",
1552 type_str, ptr);
1553
1554 for (i = 0; i < history->len; i++) {
1555 const struct drm_dp_mst_topology_ref_entry *entry =
1556 &history->entries[i];
1557 ulong *entries;
1558 uint nr_entries;
1559 u64 ts_nsec = entry->ts_nsec;
1560 u32 rem_nsec = do_div(ts_nsec, 1000000000);
1561
1562 nr_entries = stack_depot_fetch(entry->backtrace, &entries);
1563 stack_trace_snprint(buf, PAGE_SIZE, entries, nr_entries, 4);
1564
1565 drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s",
1566 entry->count,
1567 topology_ref_type_to_str(entry->type),
1568 ts_nsec, rem_nsec / 1000, buf);
1569 }
1570
1571 /* Now free the history, since this is the only time we expose it */
1572 kfree(history->entries);
1573out:
1574 kfree(buf);
1575}
1576
1577static __always_inline void
1578drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb)
1579{
1580 __dump_topology_ref_history(&mstb->topology_ref_history, mstb,
1581 "MSTB");
1582}
1583
1584static __always_inline void
1585drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port)
1586{
1587 __dump_topology_ref_history(&port->topology_ref_history, port,
1588 "Port");
1589}
1590
1591static __always_inline void
1592save_mstb_topology_ref(struct drm_dp_mst_branch *mstb,
1593 enum drm_dp_mst_topology_ref_type type)
1594{
1595 __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type);
1596}
1597
1598static __always_inline void
1599save_port_topology_ref(struct drm_dp_mst_port *port,
1600 enum drm_dp_mst_topology_ref_type type)
1601{
1602 __topology_ref_save(port->mgr, &port->topology_ref_history, type);
1603}
1604
1605static inline void
1606topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr)
1607{
1608 mutex_lock(&mgr->topology_ref_history_lock);
1609}
1610
1611static inline void
1612topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr)
1613{
1614 mutex_unlock(&mgr->topology_ref_history_lock);
1615}
1616#else
1617static inline void
1618topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {}
1619static inline void
1620topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {}
1621static inline void
1622drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {}
1623static inline void
1624drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {}
1625#define save_mstb_topology_ref(mstb, type)
1626#define save_port_topology_ref(port, type)
1627#endif
1628
1629static void drm_dp_destroy_mst_branch_device(struct kref *kref)
1630{
1631 struct drm_dp_mst_branch *mstb =
1632 container_of(kref, struct drm_dp_mst_branch, topology_kref);
1633 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1634
1635 drm_dp_mst_dump_mstb_topology_history(mstb);
1636
1637 INIT_LIST_HEAD(&mstb->destroy_next);
1638
1639 /*
1640 * This can get called under mgr->mutex, so we need to perform the
1641 * actual destruction of the mstb in another worker
1642 */
1643 mutex_lock(&mgr->delayed_destroy_lock);
1644 list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list);
1645 mutex_unlock(&mgr->delayed_destroy_lock);
1646 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1647}
1648
1649/**
1650 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1651 * branch device unless it's zero
1652 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
1653 *
1654 * Attempts to grab a topology reference to @mstb, if it hasn't yet been
1655 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
1656 * reached 0). Holding a topology reference implies that a malloc reference
1657 * will be held to @mstb as long as the user holds the topology reference.
1658 *
1659 * Care should be taken to ensure that the user has at least one malloc
1660 * reference to @mstb. If you already have a topology reference to @mstb, you
1661 * should use drm_dp_mst_topology_get_mstb() instead.
1662 *
1663 * See also:
1664 * drm_dp_mst_topology_get_mstb()
1665 * drm_dp_mst_topology_put_mstb()
1666 *
1667 * Returns:
1668 * * 1: A topology reference was grabbed successfully
1669 * * 0: @port is no longer in the topology, no reference was grabbed
1670 */
1671static int __must_check
1672drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
1673{
1674 int ret;
1675
1676 topology_ref_history_lock(mstb->mgr);
1677 ret = kref_get_unless_zero(&mstb->topology_kref);
1678 if (ret) {
1679 DRM_DEBUG("mstb %p (%d)\n",
1680 mstb, kref_read(&mstb->topology_kref));
1681 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1682 }
1683
1684 topology_ref_history_unlock(mstb->mgr);
1685
1686 return ret;
1687}
1688
1689/**
1690 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
1691 * branch device
1692 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
1693 *
1694 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or
1695 * not it's already reached 0. This is only valid to use in scenarios where
1696 * you are already guaranteed to have at least one active topology reference
1697 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
1698 *
1699 * See also:
1700 * drm_dp_mst_topology_try_get_mstb()
1701 * drm_dp_mst_topology_put_mstb()
1702 */
1703static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
1704{
1705 topology_ref_history_lock(mstb->mgr);
1706
1707 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1708 WARN_ON(kref_read(&mstb->topology_kref) == 0);
1709 kref_get(&mstb->topology_kref);
1710 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1711
1712 topology_ref_history_unlock(mstb->mgr);
1713}
1714
1715/**
1716 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
1717 * device
1718 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from
1719 *
1720 * Releases a topology reference from @mstb by decrementing
1721 * &drm_dp_mst_branch.topology_kref.
1722 *
1723 * See also:
1724 * drm_dp_mst_topology_try_get_mstb()
1725 * drm_dp_mst_topology_get_mstb()
1726 */
1727static void
1728drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
1729{
1730 topology_ref_history_lock(mstb->mgr);
1731
1732 DRM_DEBUG("mstb %p (%d)\n",
1733 mstb, kref_read(&mstb->topology_kref) - 1);
1734 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT);
1735
1736 topology_ref_history_unlock(mstb->mgr);
1737 kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
1738}
1739
1740static void drm_dp_destroy_port(struct kref *kref)
1741{
1742 struct drm_dp_mst_port *port =
1743 container_of(kref, struct drm_dp_mst_port, topology_kref);
1744 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1745
1746 drm_dp_mst_dump_port_topology_history(port);
1747
1748 /* There's nothing that needs locking to destroy an input port yet */
1749 if (port->input) {
1750 drm_dp_mst_put_port_malloc(port);
1751 return;
1752 }
1753
1754 kfree(port->cached_edid);
1755
1756 /*
1757 * we can't destroy the connector here, as we might be holding the
1758 * mode_config.mutex from an EDID retrieval
1759 */
1760 mutex_lock(&mgr->delayed_destroy_lock);
1761 list_add(&port->next, &mgr->destroy_port_list);
1762 mutex_unlock(&mgr->delayed_destroy_lock);
1763 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1764}
1765
1766/**
1767 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
1768 * port unless it's zero
1769 * @port: &struct drm_dp_mst_port to increment the topology refcount of
1770 *
1771 * Attempts to grab a topology reference to @port, if it hasn't yet been
1772 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
1773 * 0). Holding a topology reference implies that a malloc reference will be
1774 * held to @port as long as the user holds the topology reference.
1775 *
1776 * Care should be taken to ensure that the user has at least one malloc
1777 * reference to @port. If you already have a topology reference to @port, you
1778 * should use drm_dp_mst_topology_get_port() instead.
1779 *
1780 * See also:
1781 * drm_dp_mst_topology_get_port()
1782 * drm_dp_mst_topology_put_port()
1783 *
1784 * Returns:
1785 * * 1: A topology reference was grabbed successfully
1786 * * 0: @port is no longer in the topology, no reference was grabbed
1787 */
1788static int __must_check
1789drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
1790{
1791 int ret;
1792
1793 topology_ref_history_lock(port->mgr);
1794 ret = kref_get_unless_zero(&port->topology_kref);
1795 if (ret) {
1796 DRM_DEBUG("port %p (%d)\n",
1797 port, kref_read(&port->topology_kref));
1798 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1799 }
1800
1801 topology_ref_history_unlock(port->mgr);
1802 return ret;
1803}
1804
1805/**
1806 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
1807 * @port: The &struct drm_dp_mst_port to increment the topology refcount of
1808 *
1809 * Increments &drm_dp_mst_port.topology_refcount without checking whether or
1810 * not it's already reached 0. This is only valid to use in scenarios where
1811 * you are already guaranteed to have at least one active topology reference
1812 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
1813 *
1814 * See also:
1815 * drm_dp_mst_topology_try_get_port()
1816 * drm_dp_mst_topology_put_port()
1817 */
1818static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
1819{
1820 topology_ref_history_lock(port->mgr);
1821
1822 WARN_ON(kref_read(&port->topology_kref) == 0);
1823 kref_get(&port->topology_kref);
1824 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref));
1825 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1826
1827 topology_ref_history_unlock(port->mgr);
1828}
1829
1830/**
1831 * drm_dp_mst_topology_put_port() - release a topology reference to a port
1832 * @port: The &struct drm_dp_mst_port to release the topology reference from
1833 *
1834 * Releases a topology reference from @port by decrementing
1835 * &drm_dp_mst_port.topology_kref.
1836 *
1837 * See also:
1838 * drm_dp_mst_topology_try_get_port()
1839 * drm_dp_mst_topology_get_port()
1840 */
1841static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
1842{
1843 topology_ref_history_lock(port->mgr);
1844
1845 DRM_DEBUG("port %p (%d)\n",
1846 port, kref_read(&port->topology_kref) - 1);
1847 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT);
1848
1849 topology_ref_history_unlock(port->mgr);
1850 kref_put(&port->topology_kref, drm_dp_destroy_port);
1851}
1852
1853static struct drm_dp_mst_branch *
1854drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
1855 struct drm_dp_mst_branch *to_find)
1856{
1857 struct drm_dp_mst_port *port;
1858 struct drm_dp_mst_branch *rmstb;
1859
1860 if (to_find == mstb)
1861 return mstb;
1862
1863 list_for_each_entry(port, &mstb->ports, next) {
1864 if (port->mstb) {
1865 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1866 port->mstb, to_find);
1867 if (rmstb)
1868 return rmstb;
1869 }
1870 }
1871 return NULL;
1872}
1873
1874static struct drm_dp_mst_branch *
1875drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
1876 struct drm_dp_mst_branch *mstb)
1877{
1878 struct drm_dp_mst_branch *rmstb = NULL;
1879
1880 mutex_lock(&mgr->lock);
1881 if (mgr->mst_primary) {
1882 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1883 mgr->mst_primary, mstb);
1884
1885 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
1886 rmstb = NULL;
1887 }
1888 mutex_unlock(&mgr->lock);
1889 return rmstb;
1890}
1891
1892static struct drm_dp_mst_port *
1893drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
1894 struct drm_dp_mst_port *to_find)
1895{
1896 struct drm_dp_mst_port *port, *mport;
1897
1898 list_for_each_entry(port, &mstb->ports, next) {
1899 if (port == to_find)
1900 return port;
1901
1902 if (port->mstb) {
1903 mport = drm_dp_mst_topology_get_port_validated_locked(
1904 port->mstb, to_find);
1905 if (mport)
1906 return mport;
1907 }
1908 }
1909 return NULL;
1910}
1911
1912static struct drm_dp_mst_port *
1913drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
1914 struct drm_dp_mst_port *port)
1915{
1916 struct drm_dp_mst_port *rport = NULL;
1917
1918 mutex_lock(&mgr->lock);
1919 if (mgr->mst_primary) {
1920 rport = drm_dp_mst_topology_get_port_validated_locked(
1921 mgr->mst_primary, port);
1922
1923 if (rport && !drm_dp_mst_topology_try_get_port(rport))
1924 rport = NULL;
1925 }
1926 mutex_unlock(&mgr->lock);
1927 return rport;
1928}
1929
1930static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
1931{
1932 struct drm_dp_mst_port *port;
1933 int ret;
1934
1935 list_for_each_entry(port, &mstb->ports, next) {
1936 if (port->port_num == port_num) {
1937 ret = drm_dp_mst_topology_try_get_port(port);
1938 return ret ? port : NULL;
1939 }
1940 }
1941
1942 return NULL;
1943}
1944
1945/*
1946 * calculate a new RAD for this MST branch device
1947 * if parent has an LCT of 2 then it has 1 nibble of RAD,
1948 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1949 */
1950static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1951 u8 *rad)
1952{
1953 int parent_lct = port->parent->lct;
1954 int shift = 4;
1955 int idx = (parent_lct - 1) / 2;
1956
1957 if (parent_lct > 1) {
1958 memcpy(rad, port->parent->rad, idx + 1);
1959 shift = (parent_lct % 2) ? 4 : 0;
1960 } else
1961 rad[0] = 0;
1962
1963 rad[idx] |= port->port_num << shift;
1964 return parent_lct + 1;
1965}
1966
1967static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs)
1968{
1969 switch (pdt) {
1970 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1971 case DP_PEER_DEVICE_SST_SINK:
1972 return true;
1973 case DP_PEER_DEVICE_MST_BRANCHING:
1974 /* For sst branch device */
1975 if (!mcs)
1976 return true;
1977
1978 return false;
1979 }
1980 return true;
1981}
1982
1983static int
1984drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
1985 bool new_mcs)
1986{
1987 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1988 struct drm_dp_mst_branch *mstb;
1989 u8 rad[8], lct;
1990 int ret = 0;
1991
1992 if (port->pdt == new_pdt && port->mcs == new_mcs)
1993 return 0;
1994
1995 /* Teardown the old pdt, if there is one */
1996 if (port->pdt != DP_PEER_DEVICE_NONE) {
1997 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
1998 /*
1999 * If the new PDT would also have an i2c bus,
2000 * don't bother with reregistering it
2001 */
2002 if (new_pdt != DP_PEER_DEVICE_NONE &&
2003 drm_dp_mst_is_end_device(new_pdt, new_mcs)) {
2004 port->pdt = new_pdt;
2005 port->mcs = new_mcs;
2006 return 0;
2007 }
2008
2009 /* remove i2c over sideband */
2010 drm_dp_mst_unregister_i2c_bus(port);
2011 } else {
2012 mutex_lock(&mgr->lock);
2013 drm_dp_mst_topology_put_mstb(port->mstb);
2014 port->mstb = NULL;
2015 mutex_unlock(&mgr->lock);
2016 }
2017 }
2018
2019 port->pdt = new_pdt;
2020 port->mcs = new_mcs;
2021
2022 if (port->pdt != DP_PEER_DEVICE_NONE) {
2023 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2024 /* add i2c over sideband */
2025 ret = drm_dp_mst_register_i2c_bus(port);
2026 } else {
2027 lct = drm_dp_calculate_rad(port, rad);
2028 mstb = drm_dp_add_mst_branch_device(lct, rad);
2029 if (!mstb) {
2030 ret = -ENOMEM;
2031 DRM_ERROR("Failed to create MSTB for port %p",
2032 port);
2033 goto out;
2034 }
2035
2036 mutex_lock(&mgr->lock);
2037 port->mstb = mstb;
2038 mstb->mgr = port->mgr;
2039 mstb->port_parent = port;
2040
2041 /*
2042 * Make sure this port's memory allocation stays
2043 * around until its child MSTB releases it
2044 */
2045 drm_dp_mst_get_port_malloc(port);
2046 mutex_unlock(&mgr->lock);
2047
2048 /* And make sure we send a link address for this */
2049 ret = 1;
2050 }
2051 }
2052
2053out:
2054 if (ret < 0)
2055 port->pdt = DP_PEER_DEVICE_NONE;
2056 return ret;
2057}
2058
2059/**
2060 * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
2061 * @aux: Fake sideband AUX CH
2062 * @offset: address of the (first) register to read
2063 * @buffer: buffer to store the register values
2064 * @size: number of bytes in @buffer
2065 *
2066 * Performs the same functionality for remote devices via
2067 * sideband messaging as drm_dp_dpcd_read() does for local
2068 * devices via actual AUX CH.
2069 *
2070 * Return: Number of bytes read, or negative error code on failure.
2071 */
2072ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
2073 unsigned int offset, void *buffer, size_t size)
2074{
2075 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2076 aux);
2077
2078 return drm_dp_send_dpcd_read(port->mgr, port,
2079 offset, size, buffer);
2080}
2081
2082/**
2083 * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
2084 * @aux: Fake sideband AUX CH
2085 * @offset: address of the (first) register to write
2086 * @buffer: buffer containing the values to write
2087 * @size: number of bytes in @buffer
2088 *
2089 * Performs the same functionality for remote devices via
2090 * sideband messaging as drm_dp_dpcd_write() does for local
2091 * devices via actual AUX CH.
2092 *
2093 * Return: number of bytes written on success, negative error code on failure.
2094 */
2095ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
2096 unsigned int offset, void *buffer, size_t size)
2097{
2098 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2099 aux);
2100
2101 return drm_dp_send_dpcd_write(port->mgr, port,
2102 offset, size, buffer);
2103}
2104
2105static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
2106{
2107 int ret = 0;
2108
2109 memcpy(mstb->guid, guid, 16);
2110
2111 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
2112 if (mstb->port_parent) {
2113 ret = drm_dp_send_dpcd_write(mstb->mgr,
2114 mstb->port_parent,
2115 DP_GUID, 16, mstb->guid);
2116 } else {
2117 ret = drm_dp_dpcd_write(mstb->mgr->aux,
2118 DP_GUID, mstb->guid, 16);
2119 }
2120 }
2121
2122 if (ret < 16 && ret > 0)
2123 return -EPROTO;
2124
2125 return ret == 16 ? 0 : ret;
2126}
2127
2128static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
2129 int pnum,
2130 char *proppath,
2131 size_t proppath_size)
2132{
2133 int i;
2134 char temp[8];
2135
2136 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
2137 for (i = 0; i < (mstb->lct - 1); i++) {
2138 int shift = (i % 2) ? 0 : 4;
2139 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
2140
2141 snprintf(temp, sizeof(temp), "-%d", port_num);
2142 strlcat(proppath, temp, proppath_size);
2143 }
2144 snprintf(temp, sizeof(temp), "-%d", pnum);
2145 strlcat(proppath, temp, proppath_size);
2146}
2147
2148/**
2149 * drm_dp_mst_connector_late_register() - Late MST connector registration
2150 * @connector: The MST connector
2151 * @port: The MST port for this connector
2152 *
2153 * Helper to register the remote aux device for this MST port. Drivers should
2154 * call this from their mst connector's late_register hook to enable MST aux
2155 * devices.
2156 *
2157 * Return: 0 on success, negative error code on failure.
2158 */
2159int drm_dp_mst_connector_late_register(struct drm_connector *connector,
2160 struct drm_dp_mst_port *port)
2161{
2162 DRM_DEBUG_KMS("registering %s remote bus for %s\n",
2163 port->aux.name, connector->kdev->kobj.name);
2164
2165 port->aux.dev = connector->kdev;
2166 return drm_dp_aux_register_devnode(&port->aux);
2167}
2168EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
2169
2170/**
2171 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
2172 * @connector: The MST connector
2173 * @port: The MST port for this connector
2174 *
2175 * Helper to unregister the remote aux device for this MST port, registered by
2176 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst
2177 * connector's early_unregister hook.
2178 */
2179void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
2180 struct drm_dp_mst_port *port)
2181{
2182 DRM_DEBUG_KMS("unregistering %s remote bus for %s\n",
2183 port->aux.name, connector->kdev->kobj.name);
2184 drm_dp_aux_unregister_devnode(&port->aux);
2185}
2186EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
2187
2188static void
2189drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
2190 struct drm_dp_mst_port *port)
2191{
2192 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2193 char proppath[255];
2194 int ret;
2195
2196 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
2197 port->connector = mgr->cbs->add_connector(mgr, port, proppath);
2198 if (!port->connector) {
2199 ret = -ENOMEM;
2200 goto error;
2201 }
2202
2203 if (port->pdt != DP_PEER_DEVICE_NONE &&
2204 drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2205 port->cached_edid = drm_get_edid(port->connector,
2206 &port->aux.ddc);
2207 drm_connector_set_tile_property(port->connector);
2208 }
2209
2210 drm_connector_register(port->connector);
2211 return;
2212
2213error:
2214 DRM_ERROR("Failed to create connector for port %p: %d\n", port, ret);
2215}
2216
2217/*
2218 * Drop a topology reference, and unlink the port from the in-memory topology
2219 * layout
2220 */
2221static void
2222drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr,
2223 struct drm_dp_mst_port *port)
2224{
2225 mutex_lock(&mgr->lock);
2226 port->parent->num_ports--;
2227 list_del(&port->next);
2228 mutex_unlock(&mgr->lock);
2229 drm_dp_mst_topology_put_port(port);
2230}
2231
2232static struct drm_dp_mst_port *
2233drm_dp_mst_add_port(struct drm_device *dev,
2234 struct drm_dp_mst_topology_mgr *mgr,
2235 struct drm_dp_mst_branch *mstb, u8 port_number)
2236{
2237 struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
2238
2239 if (!port)
2240 return NULL;
2241
2242 kref_init(&port->topology_kref);
2243 kref_init(&port->malloc_kref);
2244 port->parent = mstb;
2245 port->port_num = port_number;
2246 port->mgr = mgr;
2247 port->aux.name = "DPMST";
2248 port->aux.dev = dev->dev;
2249 port->aux.is_remote = true;
2250
2251 /* initialize the MST downstream port's AUX crc work queue */
2252 drm_dp_remote_aux_init(&port->aux);
2253
2254 /*
2255 * Make sure the memory allocation for our parent branch stays
2256 * around until our own memory allocation is released
2257 */
2258 drm_dp_mst_get_mstb_malloc(mstb);
2259
2260 return port;
2261}
2262
2263static int
2264drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
2265 struct drm_device *dev,
2266 struct drm_dp_link_addr_reply_port *port_msg)
2267{
2268 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2269 struct drm_dp_mst_port *port;
2270 int old_ddps = 0, ret;
2271 u8 new_pdt = DP_PEER_DEVICE_NONE;
2272 bool new_mcs = 0;
2273 bool created = false, send_link_addr = false, changed = false;
2274
2275 port = drm_dp_get_port(mstb, port_msg->port_number);
2276 if (!port) {
2277 port = drm_dp_mst_add_port(dev, mgr, mstb,
2278 port_msg->port_number);
2279 if (!port)
2280 return -ENOMEM;
2281 created = true;
2282 changed = true;
2283 } else if (!port->input && port_msg->input_port && port->connector) {
2284 /* Since port->connector can't be changed here, we create a
2285 * new port if input_port changes from 0 to 1
2286 */
2287 drm_dp_mst_topology_unlink_port(mgr, port);
2288 drm_dp_mst_topology_put_port(port);
2289 port = drm_dp_mst_add_port(dev, mgr, mstb,
2290 port_msg->port_number);
2291 if (!port)
2292 return -ENOMEM;
2293 changed = true;
2294 created = true;
2295 } else if (port->input && !port_msg->input_port) {
2296 changed = true;
2297 } else if (port->connector) {
2298 /* We're updating a port that's exposed to userspace, so do it
2299 * under lock
2300 */
2301 drm_modeset_lock(&mgr->base.lock, NULL);
2302
2303 old_ddps = port->ddps;
2304 changed = port->ddps != port_msg->ddps ||
2305 (port->ddps &&
2306 (port->ldps != port_msg->legacy_device_plug_status ||
2307 port->dpcd_rev != port_msg->dpcd_revision ||
2308 port->mcs != port_msg->mcs ||
2309 port->pdt != port_msg->peer_device_type ||
2310 port->num_sdp_stream_sinks !=
2311 port_msg->num_sdp_stream_sinks));
2312 }
2313
2314 port->input = port_msg->input_port;
2315 if (!port->input)
2316 new_pdt = port_msg->peer_device_type;
2317 new_mcs = port_msg->mcs;
2318 port->ddps = port_msg->ddps;
2319 port->ldps = port_msg->legacy_device_plug_status;
2320 port->dpcd_rev = port_msg->dpcd_revision;
2321 port->num_sdp_streams = port_msg->num_sdp_streams;
2322 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
2323
2324 /* manage mstb port lists with mgr lock - take a reference
2325 for this list */
2326 if (created) {
2327 mutex_lock(&mgr->lock);
2328 drm_dp_mst_topology_get_port(port);
2329 list_add(&port->next, &mstb->ports);
2330 mstb->num_ports++;
2331 mutex_unlock(&mgr->lock);
2332 }
2333
2334 /*
2335 * Reprobe PBN caps on both hotplug, and when re-probing the link
2336 * for our parent mstb
2337 */
2338 if (old_ddps != port->ddps || !created) {
2339 if (port->ddps && !port->input) {
2340 ret = drm_dp_send_enum_path_resources(mgr, mstb,
2341 port);
2342 if (ret == 1)
2343 changed = true;
2344 } else {
2345 port->full_pbn = 0;
2346 }
2347 }
2348
2349 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2350 if (ret == 1) {
2351 send_link_addr = true;
2352 } else if (ret < 0) {
2353 DRM_ERROR("Failed to change PDT on port %p: %d\n",
2354 port, ret);
2355 goto fail;
2356 }
2357
2358 /*
2359 * If this port wasn't just created, then we're reprobing because
2360 * we're coming out of suspend. In this case, always resend the link
2361 * address if there's an MSTB on this port
2362 */
2363 if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
2364 port->mcs)
2365 send_link_addr = true;
2366
2367 if (port->connector)
2368 drm_modeset_unlock(&mgr->base.lock);
2369 else if (!port->input)
2370 drm_dp_mst_port_add_connector(mstb, port);
2371
2372 if (send_link_addr && port->mstb) {
2373 ret = drm_dp_send_link_address(mgr, port->mstb);
2374 if (ret == 1) /* MSTB below us changed */
2375 changed = true;
2376 else if (ret < 0)
2377 goto fail_put;
2378 }
2379
2380 /* put reference to this port */
2381 drm_dp_mst_topology_put_port(port);
2382 return changed;
2383
2384fail:
2385 drm_dp_mst_topology_unlink_port(mgr, port);
2386 if (port->connector)
2387 drm_modeset_unlock(&mgr->base.lock);
2388fail_put:
2389 drm_dp_mst_topology_put_port(port);
2390 return ret;
2391}
2392
2393static void
2394drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
2395 struct drm_dp_connection_status_notify *conn_stat)
2396{
2397 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2398 struct drm_dp_mst_port *port;
2399 int old_ddps, old_input, ret, i;
2400 u8 new_pdt;
2401 bool new_mcs;
2402 bool dowork = false, create_connector = false;
2403
2404 port = drm_dp_get_port(mstb, conn_stat->port_number);
2405 if (!port)
2406 return;
2407
2408 if (port->connector) {
2409 if (!port->input && conn_stat->input_port) {
2410 /*
2411 * We can't remove a connector from an already exposed
2412 * port, so just throw the port out and make sure we
2413 * reprobe the link address of it's parent MSTB
2414 */
2415 drm_dp_mst_topology_unlink_port(mgr, port);
2416 mstb->link_address_sent = false;
2417 dowork = true;
2418 goto out;
2419 }
2420
2421 /* Locking is only needed if the port's exposed to userspace */
2422 drm_modeset_lock(&mgr->base.lock, NULL);
2423 } else if (port->input && !conn_stat->input_port) {
2424 create_connector = true;
2425 /* Reprobe link address so we get num_sdp_streams */
2426 mstb->link_address_sent = false;
2427 dowork = true;
2428 }
2429
2430 old_ddps = port->ddps;
2431 old_input = port->input;
2432 port->input = conn_stat->input_port;
2433 port->ldps = conn_stat->legacy_device_plug_status;
2434 port->ddps = conn_stat->displayport_device_plug_status;
2435
2436 if (old_ddps != port->ddps) {
2437 if (port->ddps && !port->input)
2438 drm_dp_send_enum_path_resources(mgr, mstb, port);
2439 else
2440 port->full_pbn = 0;
2441 }
2442
2443 new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
2444 new_mcs = conn_stat->message_capability_status;
2445 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2446 if (ret == 1) {
2447 dowork = true;
2448 } else if (ret < 0) {
2449 DRM_ERROR("Failed to change PDT for port %p: %d\n",
2450 port, ret);
2451 dowork = false;
2452 }
2453
2454 if (!old_input && old_ddps != port->ddps && !port->ddps) {
2455 for (i = 0; i < mgr->max_payloads; i++) {
2456 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
2457 struct drm_dp_mst_port *port_validated;
2458
2459 if (!vcpi)
2460 continue;
2461
2462 port_validated =
2463 container_of(vcpi, struct drm_dp_mst_port, vcpi);
2464 port_validated =
2465 drm_dp_mst_topology_get_port_validated(mgr, port_validated);
2466 if (!port_validated) {
2467 mutex_lock(&mgr->payload_lock);
2468 vcpi->num_slots = 0;
2469 mutex_unlock(&mgr->payload_lock);
2470 } else {
2471 drm_dp_mst_topology_put_port(port_validated);
2472 }
2473 }
2474 }
2475
2476 if (port->connector)
2477 drm_modeset_unlock(&mgr->base.lock);
2478 else if (create_connector)
2479 drm_dp_mst_port_add_connector(mstb, port);
2480
2481out:
2482 drm_dp_mst_topology_put_port(port);
2483 if (dowork)
2484 queue_work(system_long_wq, &mstb->mgr->work);
2485}
2486
2487static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
2488 u8 lct, u8 *rad)
2489{
2490 struct drm_dp_mst_branch *mstb;
2491 struct drm_dp_mst_port *port;
2492 int i, ret;
2493 /* find the port by iterating down */
2494
2495 mutex_lock(&mgr->lock);
2496 mstb = mgr->mst_primary;
2497
2498 if (!mstb)
2499 goto out;
2500
2501 for (i = 0; i < lct - 1; i++) {
2502 int shift = (i % 2) ? 0 : 4;
2503 int port_num = (rad[i / 2] >> shift) & 0xf;
2504
2505 list_for_each_entry(port, &mstb->ports, next) {
2506 if (port->port_num == port_num) {
2507 mstb = port->mstb;
2508 if (!mstb) {
2509 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
2510 goto out;
2511 }
2512
2513 break;
2514 }
2515 }
2516 }
2517 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2518 if (!ret)
2519 mstb = NULL;
2520out:
2521 mutex_unlock(&mgr->lock);
2522 return mstb;
2523}
2524
2525static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
2526 struct drm_dp_mst_branch *mstb,
2527 const uint8_t *guid)
2528{
2529 struct drm_dp_mst_branch *found_mstb;
2530 struct drm_dp_mst_port *port;
2531
2532 if (memcmp(mstb->guid, guid, 16) == 0)
2533 return mstb;
2534
2535
2536 list_for_each_entry(port, &mstb->ports, next) {
2537 if (!port->mstb)
2538 continue;
2539
2540 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
2541
2542 if (found_mstb)
2543 return found_mstb;
2544 }
2545
2546 return NULL;
2547}
2548
2549static struct drm_dp_mst_branch *
2550drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
2551 const uint8_t *guid)
2552{
2553 struct drm_dp_mst_branch *mstb;
2554 int ret;
2555
2556 /* find the port by iterating down */
2557 mutex_lock(&mgr->lock);
2558
2559 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
2560 if (mstb) {
2561 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2562 if (!ret)
2563 mstb = NULL;
2564 }
2565
2566 mutex_unlock(&mgr->lock);
2567 return mstb;
2568}
2569
2570static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2571 struct drm_dp_mst_branch *mstb)
2572{
2573 struct drm_dp_mst_port *port;
2574 int ret;
2575 bool changed = false;
2576
2577 if (!mstb->link_address_sent) {
2578 ret = drm_dp_send_link_address(mgr, mstb);
2579 if (ret == 1)
2580 changed = true;
2581 else if (ret < 0)
2582 return ret;
2583 }
2584
2585 list_for_each_entry(port, &mstb->ports, next) {
2586 struct drm_dp_mst_branch *mstb_child = NULL;
2587
2588 if (port->input || !port->ddps)
2589 continue;
2590
2591 if (port->mstb)
2592 mstb_child = drm_dp_mst_topology_get_mstb_validated(
2593 mgr, port->mstb);
2594
2595 if (mstb_child) {
2596 ret = drm_dp_check_and_send_link_address(mgr,
2597 mstb_child);
2598 drm_dp_mst_topology_put_mstb(mstb_child);
2599 if (ret == 1)
2600 changed = true;
2601 else if (ret < 0)
2602 return ret;
2603 }
2604 }
2605
2606 return changed;
2607}
2608
2609static void drm_dp_mst_link_probe_work(struct work_struct *work)
2610{
2611 struct drm_dp_mst_topology_mgr *mgr =
2612 container_of(work, struct drm_dp_mst_topology_mgr, work);
2613 struct drm_device *dev = mgr->dev;
2614 struct drm_dp_mst_branch *mstb;
2615 int ret;
2616 bool clear_payload_id_table;
2617
2618 mutex_lock(&mgr->probe_lock);
2619
2620 mutex_lock(&mgr->lock);
2621 clear_payload_id_table = !mgr->payload_id_table_cleared;
2622 mgr->payload_id_table_cleared = true;
2623
2624 mstb = mgr->mst_primary;
2625 if (mstb) {
2626 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2627 if (!ret)
2628 mstb = NULL;
2629 }
2630 mutex_unlock(&mgr->lock);
2631 if (!mstb) {
2632 mutex_unlock(&mgr->probe_lock);
2633 return;
2634 }
2635
2636 /*
2637 * Certain branch devices seem to incorrectly report an available_pbn
2638 * of 0 on downstream sinks, even after clearing the
2639 * DP_PAYLOAD_ALLOCATE_* registers in
2640 * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
2641 * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
2642 * things work again.
2643 */
2644 if (clear_payload_id_table) {
2645 DRM_DEBUG_KMS("Clearing payload ID table\n");
2646 drm_dp_send_clear_payload_id_table(mgr, mstb);
2647 }
2648
2649 ret = drm_dp_check_and_send_link_address(mgr, mstb);
2650 drm_dp_mst_topology_put_mstb(mstb);
2651
2652 mutex_unlock(&mgr->probe_lock);
2653 if (ret)
2654 drm_kms_helper_hotplug_event(dev);
2655}
2656
2657static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
2658 u8 *guid)
2659{
2660 u64 salt;
2661
2662 if (memchr_inv(guid, 0, 16))
2663 return true;
2664
2665 salt = get_jiffies_64();
2666
2667 memcpy(&guid[0], &salt, sizeof(u64));
2668 memcpy(&guid[8], &salt, sizeof(u64));
2669
2670 return false;
2671}
2672
2673static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg,
2674 u8 port_num, u32 offset, u8 num_bytes)
2675{
2676 struct drm_dp_sideband_msg_req_body req;
2677
2678 req.req_type = DP_REMOTE_DPCD_READ;
2679 req.u.dpcd_read.port_number = port_num;
2680 req.u.dpcd_read.dpcd_address = offset;
2681 req.u.dpcd_read.num_bytes = num_bytes;
2682 drm_dp_encode_sideband_req(&req, msg);
2683}
2684
2685static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
2686 bool up, u8 *msg, int len)
2687{
2688 int ret;
2689 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
2690 int tosend, total, offset;
2691 int retries = 0;
2692
2693retry:
2694 total = len;
2695 offset = 0;
2696 do {
2697 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
2698
2699 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
2700 &msg[offset],
2701 tosend);
2702 if (ret != tosend) {
2703 if (ret == -EIO && retries < 5) {
2704 retries++;
2705 goto retry;
2706 }
2707 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
2708
2709 return -EIO;
2710 }
2711 offset += tosend;
2712 total -= tosend;
2713 } while (total > 0);
2714 return 0;
2715}
2716
2717static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
2718 struct drm_dp_sideband_msg_tx *txmsg)
2719{
2720 struct drm_dp_mst_branch *mstb = txmsg->dst;
2721 u8 req_type;
2722
2723 req_type = txmsg->msg[0] & 0x7f;
2724 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
2725 req_type == DP_RESOURCE_STATUS_NOTIFY)
2726 hdr->broadcast = 1;
2727 else
2728 hdr->broadcast = 0;
2729 hdr->path_msg = txmsg->path_msg;
2730 hdr->lct = mstb->lct;
2731 hdr->lcr = mstb->lct - 1;
2732 if (mstb->lct > 1)
2733 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
2734
2735 return 0;
2736}
2737/*
2738 * process a single block of the next message in the sideband queue
2739 */
2740static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2741 struct drm_dp_sideband_msg_tx *txmsg,
2742 bool up)
2743{
2744 u8 chunk[48];
2745 struct drm_dp_sideband_msg_hdr hdr;
2746 int len, space, idx, tosend;
2747 int ret;
2748
2749 if (txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
2750 return 0;
2751
2752 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
2753
2754 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED)
2755 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
2756
2757 /* make hdr from dst mst */
2758 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
2759 if (ret < 0)
2760 return ret;
2761
2762 /* amount left to send in this message */
2763 len = txmsg->cur_len - txmsg->cur_offset;
2764
2765 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
2766 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
2767
2768 tosend = min(len, space);
2769 if (len == txmsg->cur_len)
2770 hdr.somt = 1;
2771 if (space >= len)
2772 hdr.eomt = 1;
2773
2774
2775 hdr.msg_len = tosend + 1;
2776 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
2777 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
2778 /* add crc at end */
2779 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
2780 idx += tosend + 1;
2781
2782 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
2783 if (unlikely(ret) && drm_debug_enabled(DRM_UT_DP)) {
2784 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2785
2786 drm_printf(&p, "sideband msg failed to send\n");
2787 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2788 return ret;
2789 }
2790
2791 txmsg->cur_offset += tosend;
2792 if (txmsg->cur_offset == txmsg->cur_len) {
2793 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
2794 return 1;
2795 }
2796 return 0;
2797}
2798
2799static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
2800{
2801 struct drm_dp_sideband_msg_tx *txmsg;
2802 int ret;
2803
2804 WARN_ON(!mutex_is_locked(&mgr->qlock));
2805
2806 /* construct a chunk from the first msg in the tx_msg queue */
2807 if (list_empty(&mgr->tx_msg_downq))
2808 return;
2809
2810 txmsg = list_first_entry(&mgr->tx_msg_downq,
2811 struct drm_dp_sideband_msg_tx, next);
2812 ret = process_single_tx_qlock(mgr, txmsg, false);
2813 if (ret < 0) {
2814 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
2815 list_del(&txmsg->next);
2816 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
2817 wake_up_all(&mgr->tx_waitq);
2818 }
2819}
2820
2821static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
2822 struct drm_dp_sideband_msg_tx *txmsg)
2823{
2824 mutex_lock(&mgr->qlock);
2825 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
2826
2827 if (drm_debug_enabled(DRM_UT_DP)) {
2828 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2829
2830 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2831 }
2832
2833 if (list_is_singular(&mgr->tx_msg_downq))
2834 process_single_down_tx_qlock(mgr);
2835 mutex_unlock(&mgr->qlock);
2836}
2837
2838static void
2839drm_dp_dump_link_address(struct drm_dp_link_address_ack_reply *reply)
2840{
2841 struct drm_dp_link_addr_reply_port *port_reply;
2842 int i;
2843
2844 for (i = 0; i < reply->nports; i++) {
2845 port_reply = &reply->ports[i];
2846 DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n",
2847 i,
2848 port_reply->input_port,
2849 port_reply->peer_device_type,
2850 port_reply->port_number,
2851 port_reply->dpcd_revision,
2852 port_reply->mcs,
2853 port_reply->ddps,
2854 port_reply->legacy_device_plug_status,
2855 port_reply->num_sdp_streams,
2856 port_reply->num_sdp_stream_sinks);
2857 }
2858}
2859
2860static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2861 struct drm_dp_mst_branch *mstb)
2862{
2863 struct drm_dp_sideband_msg_tx *txmsg;
2864 struct drm_dp_link_address_ack_reply *reply;
2865 struct drm_dp_mst_port *port, *tmp;
2866 int i, ret, port_mask = 0;
2867 bool changed = false;
2868
2869 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2870 if (!txmsg)
2871 return -ENOMEM;
2872
2873 txmsg->dst = mstb;
2874 build_link_address(txmsg);
2875
2876 mstb->link_address_sent = true;
2877 drm_dp_queue_down_tx(mgr, txmsg);
2878
2879 /* FIXME: Actually do some real error handling here */
2880 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2881 if (ret <= 0) {
2882 DRM_ERROR("Sending link address failed with %d\n", ret);
2883 goto out;
2884 }
2885 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2886 DRM_ERROR("link address NAK received\n");
2887 ret = -EIO;
2888 goto out;
2889 }
2890
2891 reply = &txmsg->reply.u.link_addr;
2892 DRM_DEBUG_KMS("link address reply: %d\n", reply->nports);
2893 drm_dp_dump_link_address(reply);
2894
2895 ret = drm_dp_check_mstb_guid(mstb, reply->guid);
2896 if (ret) {
2897 char buf[64];
2898
2899 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf));
2900 DRM_ERROR("GUID check on %s failed: %d\n",
2901 buf, ret);
2902 goto out;
2903 }
2904
2905 for (i = 0; i < reply->nports; i++) {
2906 port_mask |= BIT(reply->ports[i].port_number);
2907 ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev,
2908 &reply->ports[i]);
2909 if (ret == 1)
2910 changed = true;
2911 else if (ret < 0)
2912 goto out;
2913 }
2914
2915 /* Prune any ports that are currently a part of mstb in our in-memory
2916 * topology, but were not seen in this link address. Usually this
2917 * means that they were removed while the topology was out of sync,
2918 * e.g. during suspend/resume
2919 */
2920 mutex_lock(&mgr->lock);
2921 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
2922 if (port_mask & BIT(port->port_num))
2923 continue;
2924
2925 DRM_DEBUG_KMS("port %d was not in link address, removing\n",
2926 port->port_num);
2927 list_del(&port->next);
2928 drm_dp_mst_topology_put_port(port);
2929 changed = true;
2930 }
2931 mutex_unlock(&mgr->lock);
2932
2933out:
2934 if (ret <= 0)
2935 mstb->link_address_sent = false;
2936 kfree(txmsg);
2937 return ret < 0 ? ret : changed;
2938}
2939
2940static void
2941drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
2942 struct drm_dp_mst_branch *mstb)
2943{
2944 struct drm_dp_sideband_msg_tx *txmsg;
2945 int ret;
2946
2947 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2948 if (!txmsg)
2949 return;
2950
2951 txmsg->dst = mstb;
2952 build_clear_payload_id_table(txmsg);
2953
2954 drm_dp_queue_down_tx(mgr, txmsg);
2955
2956 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2957 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
2958 DRM_DEBUG_KMS("clear payload table id nak received\n");
2959
2960 kfree(txmsg);
2961}
2962
2963static int
2964drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
2965 struct drm_dp_mst_branch *mstb,
2966 struct drm_dp_mst_port *port)
2967{
2968 struct drm_dp_enum_path_resources_ack_reply *path_res;
2969 struct drm_dp_sideband_msg_tx *txmsg;
2970 int ret;
2971
2972 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2973 if (!txmsg)
2974 return -ENOMEM;
2975
2976 txmsg->dst = mstb;
2977 build_enum_path_resources(txmsg, port->port_num);
2978
2979 drm_dp_queue_down_tx(mgr, txmsg);
2980
2981 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2982 if (ret > 0) {
2983 ret = 0;
2984 path_res = &txmsg->reply.u.path_resources;
2985
2986 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2987 DRM_DEBUG_KMS("enum path resources nak received\n");
2988 } else {
2989 if (port->port_num != path_res->port_number)
2990 DRM_ERROR("got incorrect port in response\n");
2991
2992 DRM_DEBUG_KMS("enum path resources %d: %d %d\n",
2993 path_res->port_number,
2994 path_res->full_payload_bw_number,
2995 path_res->avail_payload_bw_number);
2996
2997 /*
2998 * If something changed, make sure we send a
2999 * hotplug
3000 */
3001 if (port->full_pbn != path_res->full_payload_bw_number ||
3002 port->fec_capable != path_res->fec_capable)
3003 ret = 1;
3004
3005 port->full_pbn = path_res->full_payload_bw_number;
3006 port->fec_capable = path_res->fec_capable;
3007 }
3008 }
3009
3010 kfree(txmsg);
3011 return ret;
3012}
3013
3014static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
3015{
3016 if (!mstb->port_parent)
3017 return NULL;
3018
3019 if (mstb->port_parent->mstb != mstb)
3020 return mstb->port_parent;
3021
3022 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
3023}
3024
3025/*
3026 * Searches upwards in the topology starting from mstb to try to find the
3027 * closest available parent of mstb that's still connected to the rest of the
3028 * topology. This can be used in order to perform operations like releasing
3029 * payloads, where the branch device which owned the payload may no longer be
3030 * around and thus would require that the payload on the last living relative
3031 * be freed instead.
3032 */
3033static struct drm_dp_mst_branch *
3034drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
3035 struct drm_dp_mst_branch *mstb,
3036 int *port_num)
3037{
3038 struct drm_dp_mst_branch *rmstb = NULL;
3039 struct drm_dp_mst_port *found_port;
3040
3041 mutex_lock(&mgr->lock);
3042 if (!mgr->mst_primary)
3043 goto out;
3044
3045 do {
3046 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
3047 if (!found_port)
3048 break;
3049
3050 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
3051 rmstb = found_port->parent;
3052 *port_num = found_port->port_num;
3053 } else {
3054 /* Search again, starting from this parent */
3055 mstb = found_port->parent;
3056 }
3057 } while (!rmstb);
3058out:
3059 mutex_unlock(&mgr->lock);
3060 return rmstb;
3061}
3062
3063static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
3064 struct drm_dp_mst_port *port,
3065 int id,
3066 int pbn)
3067{
3068 struct drm_dp_sideband_msg_tx *txmsg;
3069 struct drm_dp_mst_branch *mstb;
3070 int ret, port_num;
3071 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
3072 int i;
3073
3074 port_num = port->port_num;
3075 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3076 if (!mstb) {
3077 mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
3078 port->parent,
3079 &port_num);
3080
3081 if (!mstb)
3082 return -EINVAL;
3083 }
3084
3085 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3086 if (!txmsg) {
3087 ret = -ENOMEM;
3088 goto fail_put;
3089 }
3090
3091 for (i = 0; i < port->num_sdp_streams; i++)
3092 sinks[i] = i;
3093
3094 txmsg->dst = mstb;
3095 build_allocate_payload(txmsg, port_num,
3096 id,
3097 pbn, port->num_sdp_streams, sinks);
3098
3099 drm_dp_queue_down_tx(mgr, txmsg);
3100
3101 /*
3102 * FIXME: there is a small chance that between getting the last
3103 * connected mstb and sending the payload message, the last connected
3104 * mstb could also be removed from the topology. In the future, this
3105 * needs to be fixed by restarting the
3106 * drm_dp_get_last_connected_port_and_mstb() search in the event of a
3107 * timeout if the topology is still connected to the system.
3108 */
3109 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3110 if (ret > 0) {
3111 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3112 ret = -EINVAL;
3113 else
3114 ret = 0;
3115 }
3116 kfree(txmsg);
3117fail_put:
3118 drm_dp_mst_topology_put_mstb(mstb);
3119 return ret;
3120}
3121
3122int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
3123 struct drm_dp_mst_port *port, bool power_up)
3124{
3125 struct drm_dp_sideband_msg_tx *txmsg;
3126 int ret;
3127
3128 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3129 if (!port)
3130 return -EINVAL;
3131
3132 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3133 if (!txmsg) {
3134 drm_dp_mst_topology_put_port(port);
3135 return -ENOMEM;
3136 }
3137
3138 txmsg->dst = port->parent;
3139 build_power_updown_phy(txmsg, port->port_num, power_up);
3140 drm_dp_queue_down_tx(mgr, txmsg);
3141
3142 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
3143 if (ret > 0) {
3144 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3145 ret = -EINVAL;
3146 else
3147 ret = 0;
3148 }
3149 kfree(txmsg);
3150 drm_dp_mst_topology_put_port(port);
3151
3152 return ret;
3153}
3154EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
3155
3156static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3157 int id,
3158 struct drm_dp_payload *payload)
3159{
3160 int ret;
3161
3162 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
3163 if (ret < 0) {
3164 payload->payload_state = 0;
3165 return ret;
3166 }
3167 payload->payload_state = DP_PAYLOAD_LOCAL;
3168 return 0;
3169}
3170
3171static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3172 struct drm_dp_mst_port *port,
3173 int id,
3174 struct drm_dp_payload *payload)
3175{
3176 int ret;
3177
3178 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
3179 if (ret < 0)
3180 return ret;
3181 payload->payload_state = DP_PAYLOAD_REMOTE;
3182 return ret;
3183}
3184
3185static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3186 struct drm_dp_mst_port *port,
3187 int id,
3188 struct drm_dp_payload *payload)
3189{
3190 DRM_DEBUG_KMS("\n");
3191 /* it's okay for these to fail */
3192 if (port) {
3193 drm_dp_payload_send_msg(mgr, port, id, 0);
3194 }
3195
3196 drm_dp_dpcd_write_payload(mgr, id, payload);
3197 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
3198 return 0;
3199}
3200
3201static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3202 int id,
3203 struct drm_dp_payload *payload)
3204{
3205 payload->payload_state = 0;
3206 return 0;
3207}
3208
3209/**
3210 * drm_dp_update_payload_part1() - Execute payload update part 1
3211 * @mgr: manager to use.
3212 *
3213 * This iterates over all proposed virtual channels, and tries to
3214 * allocate space in the link for them. For 0->slots transitions,
3215 * this step just writes the VCPI to the MST device. For slots->0
3216 * transitions, this writes the updated VCPIs and removes the
3217 * remote VC payloads.
3218 *
3219 * after calling this the driver should generate ACT and payload
3220 * packets.
3221 */
3222int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
3223{
3224 struct drm_dp_payload req_payload;
3225 struct drm_dp_mst_port *port;
3226 int i, j;
3227 int cur_slots = 1;
3228
3229 mutex_lock(&mgr->payload_lock);
3230 for (i = 0; i < mgr->max_payloads; i++) {
3231 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
3232 struct drm_dp_payload *payload = &mgr->payloads[i];
3233 bool put_port = false;
3234
3235 /* solve the current payloads - compare to the hw ones
3236 - update the hw view */
3237 req_payload.start_slot = cur_slots;
3238 if (vcpi) {
3239 port = container_of(vcpi, struct drm_dp_mst_port,
3240 vcpi);
3241
3242 /* Validated ports don't matter if we're releasing
3243 * VCPI
3244 */
3245 if (vcpi->num_slots) {
3246 port = drm_dp_mst_topology_get_port_validated(
3247 mgr, port);
3248 if (!port) {
3249 mutex_unlock(&mgr->payload_lock);
3250 return -EINVAL;
3251 }
3252 put_port = true;
3253 }
3254
3255 req_payload.num_slots = vcpi->num_slots;
3256 req_payload.vcpi = vcpi->vcpi;
3257 } else {
3258 port = NULL;
3259 req_payload.num_slots = 0;
3260 }
3261
3262 payload->start_slot = req_payload.start_slot;
3263 /* work out what is required to happen with this payload */
3264 if (payload->num_slots != req_payload.num_slots) {
3265
3266 /* need to push an update for this payload */
3267 if (req_payload.num_slots) {
3268 drm_dp_create_payload_step1(mgr, vcpi->vcpi,
3269 &req_payload);
3270 payload->num_slots = req_payload.num_slots;
3271 payload->vcpi = req_payload.vcpi;
3272
3273 } else if (payload->num_slots) {
3274 payload->num_slots = 0;
3275 drm_dp_destroy_payload_step1(mgr, port,
3276 payload->vcpi,
3277 payload);
3278 req_payload.payload_state =
3279 payload->payload_state;
3280 payload->start_slot = 0;
3281 }
3282 payload->payload_state = req_payload.payload_state;
3283 }
3284 cur_slots += req_payload.num_slots;
3285
3286 if (put_port)
3287 drm_dp_mst_topology_put_port(port);
3288 }
3289
3290 for (i = 0; i < mgr->max_payloads; /* do nothing */) {
3291 if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL) {
3292 i++;
3293 continue;
3294 }
3295
3296 DRM_DEBUG_KMS("removing payload %d\n", i);
3297 for (j = i; j < mgr->max_payloads - 1; j++) {
3298 mgr->payloads[j] = mgr->payloads[j + 1];
3299 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
3300
3301 if (mgr->proposed_vcpis[j] &&
3302 mgr->proposed_vcpis[j]->num_slots) {
3303 set_bit(j + 1, &mgr->payload_mask);
3304 } else {
3305 clear_bit(j + 1, &mgr->payload_mask);
3306 }
3307 }
3308
3309 memset(&mgr->payloads[mgr->max_payloads - 1], 0,
3310 sizeof(struct drm_dp_payload));
3311 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
3312 clear_bit(mgr->max_payloads, &mgr->payload_mask);
3313 }
3314 mutex_unlock(&mgr->payload_lock);
3315
3316 return 0;
3317}
3318EXPORT_SYMBOL(drm_dp_update_payload_part1);
3319
3320/**
3321 * drm_dp_update_payload_part2() - Execute payload update part 2
3322 * @mgr: manager to use.
3323 *
3324 * This iterates over all proposed virtual channels, and tries to
3325 * allocate space in the link for them. For 0->slots transitions,
3326 * this step writes the remote VC payload commands. For slots->0
3327 * this just resets some internal state.
3328 */
3329int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
3330{
3331 struct drm_dp_mst_port *port;
3332 int i;
3333 int ret = 0;
3334
3335 mutex_lock(&mgr->payload_lock);
3336 for (i = 0; i < mgr->max_payloads; i++) {
3337
3338 if (!mgr->proposed_vcpis[i])
3339 continue;
3340
3341 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
3342
3343 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
3344 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
3345 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3346 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
3347 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3348 }
3349 if (ret) {
3350 mutex_unlock(&mgr->payload_lock);
3351 return ret;
3352 }
3353 }
3354 mutex_unlock(&mgr->payload_lock);
3355 return 0;
3356}
3357EXPORT_SYMBOL(drm_dp_update_payload_part2);
3358
3359static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
3360 struct drm_dp_mst_port *port,
3361 int offset, int size, u8 *bytes)
3362{
3363 int ret = 0;
3364 struct drm_dp_sideband_msg_tx *txmsg;
3365 struct drm_dp_mst_branch *mstb;
3366
3367 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3368 if (!mstb)
3369 return -EINVAL;
3370
3371 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3372 if (!txmsg) {
3373 ret = -ENOMEM;
3374 goto fail_put;
3375 }
3376
3377 build_dpcd_read(txmsg, port->port_num, offset, size);
3378 txmsg->dst = port->parent;
3379
3380 drm_dp_queue_down_tx(mgr, txmsg);
3381
3382 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3383 if (ret < 0)
3384 goto fail_free;
3385
3386 /* DPCD read should never be NACKed */
3387 if (txmsg->reply.reply_type == 1) {
3388 DRM_ERROR("mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n",
3389 mstb, port->port_num, offset, size);
3390 ret = -EIO;
3391 goto fail_free;
3392 }
3393
3394 if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) {
3395 ret = -EPROTO;
3396 goto fail_free;
3397 }
3398
3399 ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes,
3400 size);
3401 memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret);
3402
3403fail_free:
3404 kfree(txmsg);
3405fail_put:
3406 drm_dp_mst_topology_put_mstb(mstb);
3407
3408 return ret;
3409}
3410
3411static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
3412 struct drm_dp_mst_port *port,
3413 int offset, int size, u8 *bytes)
3414{
3415 int ret;
3416 struct drm_dp_sideband_msg_tx *txmsg;
3417 struct drm_dp_mst_branch *mstb;
3418
3419 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3420 if (!mstb)
3421 return -EINVAL;
3422
3423 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3424 if (!txmsg) {
3425 ret = -ENOMEM;
3426 goto fail_put;
3427 }
3428
3429 build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
3430 txmsg->dst = mstb;
3431
3432 drm_dp_queue_down_tx(mgr, txmsg);
3433
3434 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3435 if (ret > 0) {
3436 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3437 ret = -EIO;
3438 else
3439 ret = size;
3440 }
3441
3442 kfree(txmsg);
3443fail_put:
3444 drm_dp_mst_topology_put_mstb(mstb);
3445 return ret;
3446}
3447
3448static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
3449{
3450 struct drm_dp_sideband_msg_reply_body reply;
3451
3452 reply.reply_type = DP_SIDEBAND_REPLY_ACK;
3453 reply.req_type = req_type;
3454 drm_dp_encode_sideband_reply(&reply, msg);
3455 return 0;
3456}
3457
3458static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
3459 struct drm_dp_mst_branch *mstb,
3460 int req_type, bool broadcast)
3461{
3462 struct drm_dp_sideband_msg_tx *txmsg;
3463
3464 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3465 if (!txmsg)
3466 return -ENOMEM;
3467
3468 txmsg->dst = mstb;
3469 drm_dp_encode_up_ack_reply(txmsg, req_type);
3470
3471 mutex_lock(&mgr->qlock);
3472 /* construct a chunk from the first msg in the tx_msg queue */
3473 process_single_tx_qlock(mgr, txmsg, true);
3474 mutex_unlock(&mgr->qlock);
3475
3476 kfree(txmsg);
3477 return 0;
3478}
3479
3480static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count)
3481{
3482 if (dp_link_bw == 0 || dp_link_count == 0)
3483 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
3484 dp_link_bw, dp_link_count);
3485
3486 return dp_link_bw * dp_link_count / 2;
3487}
3488
3489/**
3490 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
3491 * @mgr: manager to set state for
3492 * @mst_state: true to enable MST on this connector - false to disable.
3493 *
3494 * This is called by the driver when it detects an MST capable device plugged
3495 * into a DP MST capable port, or when a DP MST capable device is unplugged.
3496 */
3497int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
3498{
3499 int ret = 0;
3500 struct drm_dp_mst_branch *mstb = NULL;
3501
3502 mutex_lock(&mgr->payload_lock);
3503 mutex_lock(&mgr->lock);
3504 if (mst_state == mgr->mst_state)
3505 goto out_unlock;
3506
3507 mgr->mst_state = mst_state;
3508 /* set the device into MST mode */
3509 if (mst_state) {
3510 struct drm_dp_payload reset_pay;
3511
3512 WARN_ON(mgr->mst_primary);
3513
3514 /* get dpcd info */
3515 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
3516 if (ret != DP_RECEIVER_CAP_SIZE) {
3517 DRM_DEBUG_KMS("failed to read DPCD\n");
3518 goto out_unlock;
3519 }
3520
3521 mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1],
3522 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK);
3523 if (mgr->pbn_div == 0) {
3524 ret = -EINVAL;
3525 goto out_unlock;
3526 }
3527
3528 /* add initial branch device at LCT 1 */
3529 mstb = drm_dp_add_mst_branch_device(1, NULL);
3530 if (mstb == NULL) {
3531 ret = -ENOMEM;
3532 goto out_unlock;
3533 }
3534 mstb->mgr = mgr;
3535
3536 /* give this the main reference */
3537 mgr->mst_primary = mstb;
3538 drm_dp_mst_topology_get_mstb(mgr->mst_primary);
3539
3540 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3541 DP_MST_EN |
3542 DP_UP_REQ_EN |
3543 DP_UPSTREAM_IS_SRC);
3544 if (ret < 0)
3545 goto out_unlock;
3546
3547 reset_pay.start_slot = 0;
3548 reset_pay.num_slots = 0x3f;
3549 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
3550
3551 queue_work(system_long_wq, &mgr->work);
3552
3553 ret = 0;
3554 } else {
3555 /* disable MST on the device */
3556 mstb = mgr->mst_primary;
3557 mgr->mst_primary = NULL;
3558 /* this can fail if the device is gone */
3559 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
3560 ret = 0;
3561 memset(mgr->payloads, 0,
3562 mgr->max_payloads * sizeof(mgr->payloads[0]));
3563 memset(mgr->proposed_vcpis, 0,
3564 mgr->max_payloads * sizeof(mgr->proposed_vcpis[0]));
3565 mgr->payload_mask = 0;
3566 set_bit(0, &mgr->payload_mask);
3567 mgr->vcpi_mask = 0;
3568 mgr->payload_id_table_cleared = false;
3569 }
3570
3571out_unlock:
3572 mutex_unlock(&mgr->lock);
3573 mutex_unlock(&mgr->payload_lock);
3574 if (mstb)
3575 drm_dp_mst_topology_put_mstb(mstb);
3576 return ret;
3577
3578}
3579EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
3580
3581static void
3582drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
3583{
3584 struct drm_dp_mst_port *port;
3585
3586 /* The link address will need to be re-sent on resume */
3587 mstb->link_address_sent = false;
3588
3589 list_for_each_entry(port, &mstb->ports, next)
3590 if (port->mstb)
3591 drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb);
3592}
3593
3594/**
3595 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
3596 * @mgr: manager to suspend
3597 *
3598 * This function tells the MST device that we can't handle UP messages
3599 * anymore. This should stop it from sending any since we are suspended.
3600 */
3601void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
3602{
3603 mutex_lock(&mgr->lock);
3604 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3605 DP_MST_EN | DP_UPSTREAM_IS_SRC);
3606 mutex_unlock(&mgr->lock);
3607 flush_work(&mgr->up_req_work);
3608 flush_work(&mgr->work);
3609 flush_work(&mgr->delayed_destroy_work);
3610
3611 mutex_lock(&mgr->lock);
3612 if (mgr->mst_state && mgr->mst_primary)
3613 drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary);
3614 mutex_unlock(&mgr->lock);
3615}
3616EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
3617
3618/**
3619 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
3620 * @mgr: manager to resume
3621 * @sync: whether or not to perform topology reprobing synchronously
3622 *
3623 * This will fetch DPCD and see if the device is still there,
3624 * if it is, it will rewrite the MSTM control bits, and return.
3625 *
3626 * If the device fails this returns -1, and the driver should do
3627 * a full MST reprobe, in case we were undocked.
3628 *
3629 * During system resume (where it is assumed that the driver will be calling
3630 * drm_atomic_helper_resume()) this function should be called beforehand with
3631 * @sync set to true. In contexts like runtime resume where the driver is not
3632 * expected to be calling drm_atomic_helper_resume(), this function should be
3633 * called with @sync set to false in order to avoid deadlocking.
3634 *
3635 * Returns: -1 if the MST topology was removed while we were suspended, 0
3636 * otherwise.
3637 */
3638int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
3639 bool sync)
3640{
3641 int ret;
3642 u8 guid[16];
3643
3644 mutex_lock(&mgr->lock);
3645 if (!mgr->mst_primary)
3646 goto out_fail;
3647
3648 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd,
3649 DP_RECEIVER_CAP_SIZE);
3650 if (ret != DP_RECEIVER_CAP_SIZE) {
3651 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
3652 goto out_fail;
3653 }
3654
3655 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3656 DP_MST_EN |
3657 DP_UP_REQ_EN |
3658 DP_UPSTREAM_IS_SRC);
3659 if (ret < 0) {
3660 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
3661 goto out_fail;
3662 }
3663
3664 /* Some hubs forget their guids after they resume */
3665 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
3666 if (ret != 16) {
3667 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
3668 goto out_fail;
3669 }
3670
3671 ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid);
3672 if (ret) {
3673 DRM_DEBUG_KMS("check mstb failed - undocked during suspend?\n");
3674 goto out_fail;
3675 }
3676
3677 /*
3678 * For the final step of resuming the topology, we need to bring the
3679 * state of our in-memory topology back into sync with reality. So,
3680 * restart the probing process as if we're probing a new hub
3681 */
3682 queue_work(system_long_wq, &mgr->work);
3683 mutex_unlock(&mgr->lock);
3684
3685 if (sync) {
3686 DRM_DEBUG_KMS("Waiting for link probe work to finish re-syncing topology...\n");
3687 flush_work(&mgr->work);
3688 }
3689
3690 return 0;
3691
3692out_fail:
3693 mutex_unlock(&mgr->lock);
3694 return -1;
3695}
3696EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
3697
3698static bool
3699drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up,
3700 struct drm_dp_mst_branch **mstb)
3701{
3702 int len;
3703 u8 replyblock[32];
3704 int replylen, curreply;
3705 int ret;
3706 u8 hdrlen;
3707 struct drm_dp_sideband_msg_hdr hdr;
3708 struct drm_dp_sideband_msg_rx *msg =
3709 up ? &mgr->up_req_recv : &mgr->down_rep_recv;
3710 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE :
3711 DP_SIDEBAND_MSG_DOWN_REP_BASE;
3712
3713 if (!up)
3714 *mstb = NULL;
3715
3716 len = min(mgr->max_dpcd_transaction_bytes, 16);
3717 ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len);
3718 if (ret != len) {
3719 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
3720 return false;
3721 }
3722
3723 ret = drm_dp_decode_sideband_msg_hdr(&hdr, replyblock, len, &hdrlen);
3724 if (ret == false) {
3725 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16,
3726 1, replyblock, len, false);
3727 DRM_DEBUG_KMS("ERROR: failed header\n");
3728 return false;
3729 }
3730
3731 if (!up) {
3732 /* Caller is responsible for giving back this reference */
3733 *mstb = drm_dp_get_mst_branch_device(mgr, hdr.lct, hdr.rad);
3734 if (!*mstb) {
3735 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
3736 hdr.lct);
3737 return false;
3738 }
3739 }
3740
3741 if (!drm_dp_sideband_msg_set_header(msg, &hdr, hdrlen)) {
3742 DRM_DEBUG_KMS("sideband msg set header failed %d\n",
3743 replyblock[0]);
3744 return false;
3745 }
3746
3747 replylen = min(msg->curchunk_len, (u8)(len - hdrlen));
3748 ret = drm_dp_sideband_append_payload(msg, replyblock + hdrlen, replylen);
3749 if (!ret) {
3750 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
3751 return false;
3752 }
3753
3754 replylen = msg->curchunk_len + msg->curchunk_hdrlen - len;
3755 curreply = len;
3756 while (replylen > 0) {
3757 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
3758 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
3759 replyblock, len);
3760 if (ret != len) {
3761 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
3762 len, ret);
3763 return false;
3764 }
3765
3766 ret = drm_dp_sideband_append_payload(msg, replyblock, len);
3767 if (!ret) {
3768 DRM_DEBUG_KMS("failed to build sideband msg\n");
3769 return false;
3770 }
3771
3772 curreply += len;
3773 replylen -= len;
3774 }
3775 return true;
3776}
3777
3778static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
3779{
3780 struct drm_dp_sideband_msg_tx *txmsg;
3781 struct drm_dp_mst_branch *mstb = NULL;
3782 struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv;
3783
3784 if (!drm_dp_get_one_sb_msg(mgr, false, &mstb))
3785 goto out;
3786
3787 /* Multi-packet message transmission, don't clear the reply */
3788 if (!msg->have_eomt)
3789 goto out;
3790
3791 /* find the message */
3792 mutex_lock(&mgr->qlock);
3793 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq,
3794 struct drm_dp_sideband_msg_tx, next);
3795 mutex_unlock(&mgr->qlock);
3796
3797 /* Were we actually expecting a response, and from this mstb? */
3798 if (!txmsg || txmsg->dst != mstb) {
3799 struct drm_dp_sideband_msg_hdr *hdr;
3800
3801 hdr = &msg->initial_hdr;
3802 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
3803 mstb, hdr->seqno, hdr->lct, hdr->rad[0],
3804 msg->msg[0]);
3805 goto out_clear_reply;
3806 }
3807
3808 drm_dp_sideband_parse_reply(msg, &txmsg->reply);
3809
3810 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3811 DRM_DEBUG_KMS("Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
3812 txmsg->reply.req_type,
3813 drm_dp_mst_req_type_str(txmsg->reply.req_type),
3814 txmsg->reply.u.nak.reason,
3815 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason),
3816 txmsg->reply.u.nak.nak_data);
3817 }
3818
3819 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
3820 drm_dp_mst_topology_put_mstb(mstb);
3821
3822 mutex_lock(&mgr->qlock);
3823 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
3824 list_del(&txmsg->next);
3825 mutex_unlock(&mgr->qlock);
3826
3827 wake_up_all(&mgr->tx_waitq);
3828
3829 return 0;
3830
3831out_clear_reply:
3832 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
3833out:
3834 if (mstb)
3835 drm_dp_mst_topology_put_mstb(mstb);
3836
3837 return 0;
3838}
3839
3840static inline bool
3841drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
3842 struct drm_dp_pending_up_req *up_req)
3843{
3844 struct drm_dp_mst_branch *mstb = NULL;
3845 struct drm_dp_sideband_msg_req_body *msg = &up_req->msg;
3846 struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr;
3847 bool hotplug = false;
3848
3849 if (hdr->broadcast) {
3850 const u8 *guid = NULL;
3851
3852 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY)
3853 guid = msg->u.conn_stat.guid;
3854 else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
3855 guid = msg->u.resource_stat.guid;
3856
3857 if (guid)
3858 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
3859 } else {
3860 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
3861 }
3862
3863 if (!mstb) {
3864 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
3865 hdr->lct);
3866 return false;
3867 }
3868
3869 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */
3870 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) {
3871 drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat);
3872 hotplug = true;
3873 }
3874
3875 drm_dp_mst_topology_put_mstb(mstb);
3876 return hotplug;
3877}
3878
3879static void drm_dp_mst_up_req_work(struct work_struct *work)
3880{
3881 struct drm_dp_mst_topology_mgr *mgr =
3882 container_of(work, struct drm_dp_mst_topology_mgr,
3883 up_req_work);
3884 struct drm_dp_pending_up_req *up_req;
3885 bool send_hotplug = false;
3886
3887 mutex_lock(&mgr->probe_lock);
3888 while (true) {
3889 mutex_lock(&mgr->up_req_lock);
3890 up_req = list_first_entry_or_null(&mgr->up_req_list,
3891 struct drm_dp_pending_up_req,
3892 next);
3893 if (up_req)
3894 list_del(&up_req->next);
3895 mutex_unlock(&mgr->up_req_lock);
3896
3897 if (!up_req)
3898 break;
3899
3900 send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req);
3901 kfree(up_req);
3902 }
3903 mutex_unlock(&mgr->probe_lock);
3904
3905 if (send_hotplug)
3906 drm_kms_helper_hotplug_event(mgr->dev);
3907}
3908
3909static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
3910{
3911 struct drm_dp_pending_up_req *up_req;
3912
3913 if (!drm_dp_get_one_sb_msg(mgr, true, NULL))
3914 goto out;
3915
3916 if (!mgr->up_req_recv.have_eomt)
3917 return 0;
3918
3919 up_req = kzalloc(sizeof(*up_req), GFP_KERNEL);
3920 if (!up_req) {
3921 DRM_ERROR("Not enough memory to process MST up req\n");
3922 return -ENOMEM;
3923 }
3924 INIT_LIST_HEAD(&up_req->next);
3925
3926 drm_dp_sideband_parse_req(&mgr->up_req_recv, &up_req->msg);
3927
3928 if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY &&
3929 up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) {
3930 DRM_DEBUG_KMS("Received unknown up req type, ignoring: %x\n",
3931 up_req->msg.req_type);
3932 kfree(up_req);
3933 goto out;
3934 }
3935
3936 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type,
3937 false);
3938
3939 if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
3940 const struct drm_dp_connection_status_notify *conn_stat =
3941 &up_req->msg.u.conn_stat;
3942
3943 DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
3944 conn_stat->port_number,
3945 conn_stat->legacy_device_plug_status,
3946 conn_stat->displayport_device_plug_status,
3947 conn_stat->message_capability_status,
3948 conn_stat->input_port,
3949 conn_stat->peer_device_type);
3950 } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
3951 const struct drm_dp_resource_status_notify *res_stat =
3952 &up_req->msg.u.resource_stat;
3953
3954 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n",
3955 res_stat->port_number,
3956 res_stat->available_pbn);
3957 }
3958
3959 up_req->hdr = mgr->up_req_recv.initial_hdr;
3960 mutex_lock(&mgr->up_req_lock);
3961 list_add_tail(&up_req->next, &mgr->up_req_list);
3962 mutex_unlock(&mgr->up_req_lock);
3963 queue_work(system_long_wq, &mgr->up_req_work);
3964
3965out:
3966 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
3967 return 0;
3968}
3969
3970/**
3971 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
3972 * @mgr: manager to notify irq for.
3973 * @esi: 4 bytes from SINK_COUNT_ESI
3974 * @handled: whether the hpd interrupt was consumed or not
3975 *
3976 * This should be called from the driver when it detects a short IRQ,
3977 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
3978 * topology manager will process the sideband messages received as a result
3979 * of this.
3980 */
3981int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
3982{
3983 int ret = 0;
3984 int sc;
3985 *handled = false;
3986 sc = esi[0] & 0x3f;
3987
3988 if (sc != mgr->sink_count) {
3989 mgr->sink_count = sc;
3990 *handled = true;
3991 }
3992
3993 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
3994 ret = drm_dp_mst_handle_down_rep(mgr);
3995 *handled = true;
3996 }
3997
3998 if (esi[1] & DP_UP_REQ_MSG_RDY) {
3999 ret |= drm_dp_mst_handle_up_req(mgr);
4000 *handled = true;
4001 }
4002
4003 drm_dp_mst_kick_tx(mgr);
4004 return ret;
4005}
4006EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
4007
4008/**
4009 * drm_dp_mst_detect_port() - get connection status for an MST port
4010 * @connector: DRM connector for this port
4011 * @ctx: The acquisition context to use for grabbing locks
4012 * @mgr: manager for this port
4013 * @port: pointer to a port
4014 *
4015 * This returns the current connection state for a port.
4016 */
4017int
4018drm_dp_mst_detect_port(struct drm_connector *connector,
4019 struct drm_modeset_acquire_ctx *ctx,
4020 struct drm_dp_mst_topology_mgr *mgr,
4021 struct drm_dp_mst_port *port)
4022{
4023 int ret;
4024
4025 /* we need to search for the port in the mgr in case it's gone */
4026 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4027 if (!port)
4028 return connector_status_disconnected;
4029
4030 ret = drm_modeset_lock(&mgr->base.lock, ctx);
4031 if (ret)
4032 goto out;
4033
4034 ret = connector_status_disconnected;
4035
4036 if (!port->ddps)
4037 goto out;
4038
4039 switch (port->pdt) {
4040 case DP_PEER_DEVICE_NONE:
4041 case DP_PEER_DEVICE_MST_BRANCHING:
4042 if (!port->mcs)
4043 ret = connector_status_connected;
4044 break;
4045
4046 case DP_PEER_DEVICE_SST_SINK:
4047 ret = connector_status_connected;
4048 /* for logical ports - cache the EDID */
4049 if (port->port_num >= 8 && !port->cached_edid) {
4050 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
4051 }
4052 break;
4053 case DP_PEER_DEVICE_DP_LEGACY_CONV:
4054 if (port->ldps)
4055 ret = connector_status_connected;
4056 break;
4057 }
4058out:
4059 drm_dp_mst_topology_put_port(port);
4060 return ret;
4061}
4062EXPORT_SYMBOL(drm_dp_mst_detect_port);
4063
4064/**
4065 * drm_dp_mst_get_edid() - get EDID for an MST port
4066 * @connector: toplevel connector to get EDID for
4067 * @mgr: manager for this port
4068 * @port: unverified pointer to a port.
4069 *
4070 * This returns an EDID for the port connected to a connector,
4071 * It validates the pointer still exists so the caller doesn't require a
4072 * reference.
4073 */
4074struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4075{
4076 struct edid *edid = NULL;
4077
4078 /* we need to search for the port in the mgr in case it's gone */
4079 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4080 if (!port)
4081 return NULL;
4082
4083 if (port->cached_edid)
4084 edid = drm_edid_duplicate(port->cached_edid);
4085 else {
4086 edid = drm_get_edid(connector, &port->aux.ddc);
4087 }
4088 port->has_audio = drm_detect_monitor_audio(edid);
4089 drm_dp_mst_topology_put_port(port);
4090 return edid;
4091}
4092EXPORT_SYMBOL(drm_dp_mst_get_edid);
4093
4094/**
4095 * drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
4096 * @mgr: manager to use
4097 * @pbn: payload bandwidth to convert into slots.
4098 *
4099 * Calculate the number of VCPI slots that will be required for the given PBN
4100 * value. This function is deprecated, and should not be used in atomic
4101 * drivers.
4102 *
4103 * RETURNS:
4104 * The total slots required for this port, or error.
4105 */
4106int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
4107 int pbn)
4108{
4109 int num_slots;
4110
4111 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
4112
4113 /* max. time slots - one slot for MTP header */
4114 if (num_slots > 63)
4115 return -ENOSPC;
4116 return num_slots;
4117}
4118EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
4119
4120static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4121 struct drm_dp_vcpi *vcpi, int pbn, int slots)
4122{
4123 int ret;
4124
4125 /* max. time slots - one slot for MTP header */
4126 if (slots > 63)
4127 return -ENOSPC;
4128
4129 vcpi->pbn = pbn;
4130 vcpi->aligned_pbn = slots * mgr->pbn_div;
4131 vcpi->num_slots = slots;
4132
4133 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
4134 if (ret < 0)
4135 return ret;
4136 return 0;
4137}
4138
4139/**
4140 * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
4141 * @state: global atomic state
4142 * @mgr: MST topology manager for the port
4143 * @port: port to find vcpi slots for
4144 * @pbn: bandwidth required for the mode in PBN
4145 * @pbn_div: divider for DSC mode that takes FEC into account
4146 *
4147 * Allocates VCPI slots to @port, replacing any previous VCPI allocations it
4148 * may have had. Any atomic drivers which support MST must call this function
4149 * in their &drm_encoder_helper_funcs.atomic_check() callback to change the
4150 * current VCPI allocation for the new state, but only when
4151 * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set
4152 * to ensure compatibility with userspace applications that still use the
4153 * legacy modesetting UAPI.
4154 *
4155 * Allocations set by this function are not checked against the bandwidth
4156 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
4157 *
4158 * Additionally, it is OK to call this function multiple times on the same
4159 * @port as needed. It is not OK however, to call this function and
4160 * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
4161 *
4162 * See also:
4163 * drm_dp_atomic_release_vcpi_slots()
4164 * drm_dp_mst_atomic_check()
4165 *
4166 * Returns:
4167 * Total slots in the atomic state assigned for this port, or a negative error
4168 * code if the port no longer exists
4169 */
4170int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
4171 struct drm_dp_mst_topology_mgr *mgr,
4172 struct drm_dp_mst_port *port, int pbn,
4173 int pbn_div)
4174{
4175 struct drm_dp_mst_topology_state *topology_state;
4176 struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
4177 int prev_slots, prev_bw, req_slots;
4178
4179 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4180 if (IS_ERR(topology_state))
4181 return PTR_ERR(topology_state);
4182
4183 /* Find the current allocation for this port, if any */
4184 list_for_each_entry(pos, &topology_state->vcpis, next) {
4185 if (pos->port == port) {
4186 vcpi = pos;
4187 prev_slots = vcpi->vcpi;
4188 prev_bw = vcpi->pbn;
4189
4190 /*
4191 * This should never happen, unless the driver tries
4192 * releasing and allocating the same VCPI allocation,
4193 * which is an error
4194 */
4195 if (WARN_ON(!prev_slots)) {
4196 DRM_ERROR("cannot allocate and release VCPI on [MST PORT:%p] in the same state\n",
4197 port);
4198 return -EINVAL;
4199 }
4200
4201 break;
4202 }
4203 }
4204 if (!vcpi) {
4205 prev_slots = 0;
4206 prev_bw = 0;
4207 }
4208
4209 if (pbn_div <= 0)
4210 pbn_div = mgr->pbn_div;
4211
4212 req_slots = DIV_ROUND_UP(pbn, pbn_div);
4213
4214 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
4215 port->connector->base.id, port->connector->name,
4216 port, prev_slots, req_slots);
4217 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n",
4218 port->connector->base.id, port->connector->name,
4219 port, prev_bw, pbn);
4220
4221 /* Add the new allocation to the state */
4222 if (!vcpi) {
4223 vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL);
4224 if (!vcpi)
4225 return -ENOMEM;
4226
4227 drm_dp_mst_get_port_malloc(port);
4228 vcpi->port = port;
4229 list_add(&vcpi->next, &topology_state->vcpis);
4230 }
4231 vcpi->vcpi = req_slots;
4232 vcpi->pbn = pbn;
4233
4234 return req_slots;
4235}
4236EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
4237
4238/**
4239 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
4240 * @state: global atomic state
4241 * @mgr: MST topology manager for the port
4242 * @port: The port to release the VCPI slots from
4243 *
4244 * Releases any VCPI slots that have been allocated to a port in the atomic
4245 * state. Any atomic drivers which support MST must call this function in
4246 * their &drm_connector_helper_funcs.atomic_check() callback when the
4247 * connector will no longer have VCPI allocated (e.g. because its CRTC was
4248 * removed) when it had VCPI allocated in the previous atomic state.
4249 *
4250 * It is OK to call this even if @port has been removed from the system.
4251 * Additionally, it is OK to call this function multiple times on the same
4252 * @port as needed. It is not OK however, to call this function and
4253 * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
4254 * phase.
4255 *
4256 * See also:
4257 * drm_dp_atomic_find_vcpi_slots()
4258 * drm_dp_mst_atomic_check()
4259 *
4260 * Returns:
4261 * 0 if all slots for this port were added back to
4262 * &drm_dp_mst_topology_state.avail_slots or negative error code
4263 */
4264int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
4265 struct drm_dp_mst_topology_mgr *mgr,
4266 struct drm_dp_mst_port *port)
4267{
4268 struct drm_dp_mst_topology_state *topology_state;
4269 struct drm_dp_vcpi_allocation *pos;
4270 bool found = false;
4271
4272 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4273 if (IS_ERR(topology_state))
4274 return PTR_ERR(topology_state);
4275
4276 list_for_each_entry(pos, &topology_state->vcpis, next) {
4277 if (pos->port == port) {
4278 found = true;
4279 break;
4280 }
4281 }
4282 if (WARN_ON(!found)) {
4283 DRM_ERROR("no VCPI for [MST PORT:%p] found in mst state %p\n",
4284 port, &topology_state->base);
4285 return -EINVAL;
4286 }
4287
4288 DRM_DEBUG_ATOMIC("[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi);
4289 if (pos->vcpi) {
4290 drm_dp_mst_put_port_malloc(port);
4291 pos->vcpi = 0;
4292 pos->pbn = 0;
4293 }
4294
4295 return 0;
4296}
4297EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
4298
4299/**
4300 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
4301 * @mgr: manager for this port
4302 * @port: port to allocate a virtual channel for.
4303 * @pbn: payload bandwidth number to request
4304 * @slots: returned number of slots for this PBN.
4305 */
4306bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4307 struct drm_dp_mst_port *port, int pbn, int slots)
4308{
4309 int ret;
4310
4311 if (slots < 0)
4312 return false;
4313
4314 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4315 if (!port)
4316 return false;
4317
4318 if (port->vcpi.vcpi > 0) {
4319 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
4320 port->vcpi.vcpi, port->vcpi.pbn, pbn);
4321 if (pbn == port->vcpi.pbn) {
4322 drm_dp_mst_topology_put_port(port);
4323 return true;
4324 }
4325 }
4326
4327 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
4328 if (ret) {
4329 DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
4330 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
4331 drm_dp_mst_topology_put_port(port);
4332 goto out;
4333 }
4334 DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
4335 pbn, port->vcpi.num_slots);
4336
4337 /* Keep port allocated until its payload has been removed */
4338 drm_dp_mst_get_port_malloc(port);
4339 drm_dp_mst_topology_put_port(port);
4340 return true;
4341out:
4342 return false;
4343}
4344EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
4345
4346int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4347{
4348 int slots = 0;
4349
4350 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4351 if (!port)
4352 return slots;
4353
4354 slots = port->vcpi.num_slots;
4355 drm_dp_mst_topology_put_port(port);
4356 return slots;
4357}
4358EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
4359
4360/**
4361 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
4362 * @mgr: manager for this port
4363 * @port: unverified pointer to a port.
4364 *
4365 * This just resets the number of slots for the ports VCPI for later programming.
4366 */
4367void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4368{
4369 /*
4370 * A port with VCPI will remain allocated until its VCPI is
4371 * released, no verified ref needed
4372 */
4373
4374 port->vcpi.num_slots = 0;
4375}
4376EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
4377
4378/**
4379 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
4380 * @mgr: manager for this port
4381 * @port: port to deallocate vcpi for
4382 *
4383 * This can be called unconditionally, regardless of whether
4384 * drm_dp_mst_allocate_vcpi() succeeded or not.
4385 */
4386void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4387 struct drm_dp_mst_port *port)
4388{
4389 if (!port->vcpi.vcpi)
4390 return;
4391
4392 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
4393 port->vcpi.num_slots = 0;
4394 port->vcpi.pbn = 0;
4395 port->vcpi.aligned_pbn = 0;
4396 port->vcpi.vcpi = 0;
4397 drm_dp_mst_put_port_malloc(port);
4398}
4399EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
4400
4401static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
4402 int id, struct drm_dp_payload *payload)
4403{
4404 u8 payload_alloc[3], status;
4405 int ret;
4406 int retries = 0;
4407
4408 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
4409 DP_PAYLOAD_TABLE_UPDATED);
4410
4411 payload_alloc[0] = id;
4412 payload_alloc[1] = payload->start_slot;
4413 payload_alloc[2] = payload->num_slots;
4414
4415 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
4416 if (ret != 3) {
4417 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
4418 goto fail;
4419 }
4420
4421retry:
4422 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4423 if (ret < 0) {
4424 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
4425 goto fail;
4426 }
4427
4428 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
4429 retries++;
4430 if (retries < 20) {
4431 usleep_range(10000, 20000);
4432 goto retry;
4433 }
4434 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
4435 ret = -EINVAL;
4436 goto fail;
4437 }
4438 ret = 0;
4439fail:
4440 return ret;
4441}
4442
4443static int do_get_act_status(struct drm_dp_aux *aux)
4444{
4445 int ret;
4446 u8 status;
4447
4448 ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4449 if (ret < 0)
4450 return ret;
4451
4452 return status;
4453}
4454
4455/**
4456 * drm_dp_check_act_status() - Polls for ACT handled status.
4457 * @mgr: manager to use
4458 *
4459 * Tries waiting for the MST hub to finish updating it's payload table by
4460 * polling for the ACT handled bit for up to 3 seconds (yes-some hubs really
4461 * take that long).
4462 *
4463 * Returns:
4464 * 0 if the ACT was handled in time, negative error code on failure.
4465 */
4466int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
4467{
4468 /*
4469 * There doesn't seem to be any recommended retry count or timeout in
4470 * the MST specification. Since some hubs have been observed to take
4471 * over 1 second to update their payload allocations under certain
4472 * conditions, we use a rather large timeout value.
4473 */
4474 const int timeout_ms = 3000;
4475 int ret, status;
4476
4477 ret = readx_poll_timeout(do_get_act_status, mgr->aux, status,
4478 status & DP_PAYLOAD_ACT_HANDLED || status < 0,
4479 200, timeout_ms * USEC_PER_MSEC);
4480 if (ret < 0 && status >= 0) {
4481 DRM_ERROR("Failed to get ACT after %dms, last status: %02x\n",
4482 timeout_ms, status);
4483 return -EINVAL;
4484 } else if (status < 0) {
4485 /*
4486 * Failure here isn't unexpected - the hub may have
4487 * just been unplugged
4488 */
4489 DRM_DEBUG_KMS("Failed to read payload table status: %d\n",
4490 status);
4491 return status;
4492 }
4493
4494 return 0;
4495}
4496EXPORT_SYMBOL(drm_dp_check_act_status);
4497
4498/**
4499 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
4500 * @clock: dot clock for the mode
4501 * @bpp: bpp for the mode.
4502 * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel
4503 *
4504 * This uses the formula in the spec to calculate the PBN value for a mode.
4505 */
4506int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc)
4507{
4508 /*
4509 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
4510 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
4511 * common multiplier to render an integer PBN for all link rate/lane
4512 * counts combinations
4513 * calculate
4514 * peak_kbps *= (1006/1000)
4515 * peak_kbps *= (64/54)
4516 * peak_kbps *= 8 convert to bytes
4517 *
4518 * If the bpp is in units of 1/16, further divide by 16. Put this
4519 * factor in the numerator rather than the denominator to avoid
4520 * integer overflow
4521 */
4522
4523 if (dsc)
4524 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006),
4525 8 * 54 * 1000 * 1000);
4526
4527 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
4528 8 * 54 * 1000 * 1000);
4529}
4530EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
4531
4532/* we want to kick the TX after we've ack the up/down IRQs. */
4533static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
4534{
4535 queue_work(system_long_wq, &mgr->tx_work);
4536}
4537
4538static void drm_dp_mst_dump_mstb(struct seq_file *m,
4539 struct drm_dp_mst_branch *mstb)
4540{
4541 struct drm_dp_mst_port *port;
4542 int tabs = mstb->lct;
4543 char prefix[10];
4544 int i;
4545
4546 for (i = 0; i < tabs; i++)
4547 prefix[i] = '\t';
4548 prefix[i] = '\0';
4549
4550 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
4551 list_for_each_entry(port, &mstb->ports, next) {
4552 seq_printf(m, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->input, port->pdt, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
4553 if (port->mstb)
4554 drm_dp_mst_dump_mstb(m, port->mstb);
4555 }
4556}
4557
4558#define DP_PAYLOAD_TABLE_SIZE 64
4559
4560static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
4561 char *buf)
4562{
4563 int i;
4564
4565 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
4566 if (drm_dp_dpcd_read(mgr->aux,
4567 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
4568 &buf[i], 16) != 16)
4569 return false;
4570 }
4571 return true;
4572}
4573
4574static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
4575 struct drm_dp_mst_port *port, char *name,
4576 int namelen)
4577{
4578 struct edid *mst_edid;
4579
4580 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
4581 drm_edid_get_monitor_name(mst_edid, name, namelen);
4582}
4583
4584/**
4585 * drm_dp_mst_dump_topology(): dump topology to seq file.
4586 * @m: seq_file to dump output to
4587 * @mgr: manager to dump current topology for.
4588 *
4589 * helper to dump MST topology to a seq file for debugfs.
4590 */
4591void drm_dp_mst_dump_topology(struct seq_file *m,
4592 struct drm_dp_mst_topology_mgr *mgr)
4593{
4594 int i;
4595 struct drm_dp_mst_port *port;
4596
4597 mutex_lock(&mgr->lock);
4598 if (mgr->mst_primary)
4599 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
4600
4601 /* dump VCPIs */
4602 mutex_unlock(&mgr->lock);
4603
4604 mutex_lock(&mgr->payload_lock);
4605 seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
4606 mgr->max_payloads);
4607
4608 for (i = 0; i < mgr->max_payloads; i++) {
4609 if (mgr->proposed_vcpis[i]) {
4610 char name[14];
4611
4612 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
4613 fetch_monitor_name(mgr, port, name, sizeof(name));
4614 seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
4615 port->port_num, port->vcpi.vcpi,
4616 port->vcpi.num_slots,
4617 (*name != 0) ? name : "Unknown");
4618 } else
4619 seq_printf(m, "vcpi %d:unused\n", i);
4620 }
4621 for (i = 0; i < mgr->max_payloads; i++) {
4622 seq_printf(m, "payload %d: %d, %d, %d\n",
4623 i,
4624 mgr->payloads[i].payload_state,
4625 mgr->payloads[i].start_slot,
4626 mgr->payloads[i].num_slots);
4627
4628
4629 }
4630 mutex_unlock(&mgr->payload_lock);
4631
4632 mutex_lock(&mgr->lock);
4633 if (mgr->mst_primary) {
4634 u8 buf[DP_PAYLOAD_TABLE_SIZE];
4635 int ret;
4636
4637 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
4638 if (ret) {
4639 seq_printf(m, "dpcd read failed\n");
4640 goto out;
4641 }
4642 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
4643
4644 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
4645 if (ret) {
4646 seq_printf(m, "faux/mst read failed\n");
4647 goto out;
4648 }
4649 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
4650
4651 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
4652 if (ret) {
4653 seq_printf(m, "mst ctrl read failed\n");
4654 goto out;
4655 }
4656 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
4657
4658 /* dump the standard OUI branch header */
4659 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
4660 if (ret) {
4661 seq_printf(m, "branch oui read failed\n");
4662 goto out;
4663 }
4664 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
4665
4666 for (i = 0x3; i < 0x8 && buf[i]; i++)
4667 seq_printf(m, "%c", buf[i]);
4668 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
4669 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
4670 if (dump_dp_payload_table(mgr, buf))
4671 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
4672 }
4673
4674out:
4675 mutex_unlock(&mgr->lock);
4676
4677}
4678EXPORT_SYMBOL(drm_dp_mst_dump_topology);
4679
4680static void drm_dp_tx_work(struct work_struct *work)
4681{
4682 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
4683
4684 mutex_lock(&mgr->qlock);
4685 if (!list_empty(&mgr->tx_msg_downq))
4686 process_single_down_tx_qlock(mgr);
4687 mutex_unlock(&mgr->qlock);
4688}
4689
4690static inline void
4691drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port)
4692{
4693 drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs);
4694
4695 if (port->connector) {
4696 drm_connector_unregister(port->connector);
4697 drm_connector_put(port->connector);
4698 }
4699
4700 drm_dp_mst_put_port_malloc(port);
4701}
4702
4703static inline void
4704drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb)
4705{
4706 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
4707 struct drm_dp_mst_port *port, *port_tmp;
4708 struct drm_dp_sideband_msg_tx *txmsg, *txmsg_tmp;
4709 bool wake_tx = false;
4710
4711 mutex_lock(&mgr->lock);
4712 list_for_each_entry_safe(port, port_tmp, &mstb->ports, next) {
4713 list_del(&port->next);
4714 drm_dp_mst_topology_put_port(port);
4715 }
4716 mutex_unlock(&mgr->lock);
4717
4718 /* drop any tx slot msg */
4719 mutex_lock(&mstb->mgr->qlock);
4720 list_for_each_entry_safe(txmsg, txmsg_tmp, &mgr->tx_msg_downq, next) {
4721 if (txmsg->dst != mstb)
4722 continue;
4723
4724 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
4725 list_del(&txmsg->next);
4726 wake_tx = true;
4727 }
4728 mutex_unlock(&mstb->mgr->qlock);
4729
4730 if (wake_tx)
4731 wake_up_all(&mstb->mgr->tx_waitq);
4732
4733 drm_dp_mst_put_mstb_malloc(mstb);
4734}
4735
4736static void drm_dp_delayed_destroy_work(struct work_struct *work)
4737{
4738 struct drm_dp_mst_topology_mgr *mgr =
4739 container_of(work, struct drm_dp_mst_topology_mgr,
4740 delayed_destroy_work);
4741 bool send_hotplug = false, go_again;
4742
4743 /*
4744 * Not a regular list traverse as we have to drop the destroy
4745 * connector lock before destroying the mstb/port, to avoid AB->BA
4746 * ordering between this lock and the config mutex.
4747 */
4748 do {
4749 go_again = false;
4750
4751 for (;;) {
4752 struct drm_dp_mst_branch *mstb;
4753
4754 mutex_lock(&mgr->delayed_destroy_lock);
4755 mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list,
4756 struct drm_dp_mst_branch,
4757 destroy_next);
4758 if (mstb)
4759 list_del(&mstb->destroy_next);
4760 mutex_unlock(&mgr->delayed_destroy_lock);
4761
4762 if (!mstb)
4763 break;
4764
4765 drm_dp_delayed_destroy_mstb(mstb);
4766 go_again = true;
4767 }
4768
4769 for (;;) {
4770 struct drm_dp_mst_port *port;
4771
4772 mutex_lock(&mgr->delayed_destroy_lock);
4773 port = list_first_entry_or_null(&mgr->destroy_port_list,
4774 struct drm_dp_mst_port,
4775 next);
4776 if (port)
4777 list_del(&port->next);
4778 mutex_unlock(&mgr->delayed_destroy_lock);
4779
4780 if (!port)
4781 break;
4782
4783 drm_dp_delayed_destroy_port(port);
4784 send_hotplug = true;
4785 go_again = true;
4786 }
4787 } while (go_again);
4788
4789 if (send_hotplug)
4790 drm_kms_helper_hotplug_event(mgr->dev);
4791}
4792
4793static struct drm_private_state *
4794drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
4795{
4796 struct drm_dp_mst_topology_state *state, *old_state =
4797 to_dp_mst_topology_state(obj->state);
4798 struct drm_dp_vcpi_allocation *pos, *vcpi;
4799
4800 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
4801 if (!state)
4802 return NULL;
4803
4804 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
4805
4806 INIT_LIST_HEAD(&state->vcpis);
4807
4808 list_for_each_entry(pos, &old_state->vcpis, next) {
4809 /* Prune leftover freed VCPI allocations */
4810 if (!pos->vcpi)
4811 continue;
4812
4813 vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL);
4814 if (!vcpi)
4815 goto fail;
4816
4817 drm_dp_mst_get_port_malloc(vcpi->port);
4818 list_add(&vcpi->next, &state->vcpis);
4819 }
4820
4821 return &state->base;
4822
4823fail:
4824 list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) {
4825 drm_dp_mst_put_port_malloc(pos->port);
4826 kfree(pos);
4827 }
4828 kfree(state);
4829
4830 return NULL;
4831}
4832
4833static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
4834 struct drm_private_state *state)
4835{
4836 struct drm_dp_mst_topology_state *mst_state =
4837 to_dp_mst_topology_state(state);
4838 struct drm_dp_vcpi_allocation *pos, *tmp;
4839
4840 list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) {
4841 /* We only keep references to ports with non-zero VCPIs */
4842 if (pos->vcpi)
4843 drm_dp_mst_put_port_malloc(pos->port);
4844 kfree(pos);
4845 }
4846
4847 kfree(mst_state);
4848}
4849
4850static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
4851 struct drm_dp_mst_branch *branch)
4852{
4853 while (port->parent) {
4854 if (port->parent == branch)
4855 return true;
4856
4857 if (port->parent->port_parent)
4858 port = port->parent->port_parent;
4859 else
4860 break;
4861 }
4862 return false;
4863}
4864
4865static int
4866drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
4867 struct drm_dp_mst_topology_state *state);
4868
4869static int
4870drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb,
4871 struct drm_dp_mst_topology_state *state)
4872{
4873 struct drm_dp_vcpi_allocation *vcpi;
4874 struct drm_dp_mst_port *port;
4875 int pbn_used = 0, ret;
4876 bool found = false;
4877
4878 /* Check that we have at least one port in our state that's downstream
4879 * of this branch, otherwise we can skip this branch
4880 */
4881 list_for_each_entry(vcpi, &state->vcpis, next) {
4882 if (!vcpi->pbn ||
4883 !drm_dp_mst_port_downstream_of_branch(vcpi->port, mstb))
4884 continue;
4885
4886 found = true;
4887 break;
4888 }
4889 if (!found)
4890 return 0;
4891
4892 if (mstb->port_parent)
4893 DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n",
4894 mstb->port_parent->parent, mstb->port_parent,
4895 mstb);
4896 else
4897 DRM_DEBUG_ATOMIC("[MSTB:%p] Checking bandwidth limits\n",
4898 mstb);
4899
4900 list_for_each_entry(port, &mstb->ports, next) {
4901 ret = drm_dp_mst_atomic_check_port_bw_limit(port, state);
4902 if (ret < 0)
4903 return ret;
4904
4905 pbn_used += ret;
4906 }
4907
4908 return pbn_used;
4909}
4910
4911static int
4912drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
4913 struct drm_dp_mst_topology_state *state)
4914{
4915 struct drm_dp_vcpi_allocation *vcpi;
4916 int pbn_used = 0;
4917
4918 if (port->pdt == DP_PEER_DEVICE_NONE)
4919 return 0;
4920
4921 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
4922 bool found = false;
4923
4924 list_for_each_entry(vcpi, &state->vcpis, next) {
4925 if (vcpi->port != port)
4926 continue;
4927 if (!vcpi->pbn)
4928 return 0;
4929
4930 found = true;
4931 break;
4932 }
4933 if (!found)
4934 return 0;
4935
4936 /* This should never happen, as it means we tried to
4937 * set a mode before querying the full_pbn
4938 */
4939 if (WARN_ON(!port->full_pbn))
4940 return -EINVAL;
4941
4942 pbn_used = vcpi->pbn;
4943 } else {
4944 pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb,
4945 state);
4946 if (pbn_used <= 0)
4947 return pbn_used;
4948 }
4949
4950 if (pbn_used > port->full_pbn) {
4951 DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n",
4952 port->parent, port, pbn_used,
4953 port->full_pbn);
4954 return -ENOSPC;
4955 }
4956
4957 DRM_DEBUG_ATOMIC("[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n",
4958 port->parent, port, pbn_used, port->full_pbn);
4959
4960 return pbn_used;
4961}
4962
4963static inline int
4964drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr,
4965 struct drm_dp_mst_topology_state *mst_state)
4966{
4967 struct drm_dp_vcpi_allocation *vcpi;
4968 int avail_slots = 63, payload_count = 0;
4969
4970 list_for_each_entry(vcpi, &mst_state->vcpis, next) {
4971 /* Releasing VCPI is always OK-even if the port is gone */
4972 if (!vcpi->vcpi) {
4973 DRM_DEBUG_ATOMIC("[MST PORT:%p] releases all VCPI slots\n",
4974 vcpi->port);
4975 continue;
4976 }
4977
4978 DRM_DEBUG_ATOMIC("[MST PORT:%p] requires %d vcpi slots\n",
4979 vcpi->port, vcpi->vcpi);
4980
4981 avail_slots -= vcpi->vcpi;
4982 if (avail_slots < 0) {
4983 DRM_DEBUG_ATOMIC("[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n",
4984 vcpi->port, mst_state,
4985 avail_slots + vcpi->vcpi);
4986 return -ENOSPC;
4987 }
4988
4989 if (++payload_count > mgr->max_payloads) {
4990 DRM_DEBUG_ATOMIC("[MST MGR:%p] state %p has too many payloads (max=%d)\n",
4991 mgr, mst_state, mgr->max_payloads);
4992 return -EINVAL;
4993 }
4994 }
4995 DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
4996 mgr, mst_state, avail_slots,
4997 63 - avail_slots);
4998
4999 return 0;
5000}
5001
5002/**
5003 * drm_dp_mst_add_affected_dsc_crtcs
5004 * @state: Pointer to the new struct drm_dp_mst_topology_state
5005 * @mgr: MST topology manager
5006 *
5007 * Whenever there is a change in mst topology
5008 * DSC configuration would have to be recalculated
5009 * therefore we need to trigger modeset on all affected
5010 * CRTCs in that topology
5011 *
5012 * See also:
5013 * drm_dp_mst_atomic_enable_dsc()
5014 */
5015int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr)
5016{
5017 struct drm_dp_mst_topology_state *mst_state;
5018 struct drm_dp_vcpi_allocation *pos;
5019 struct drm_connector *connector;
5020 struct drm_connector_state *conn_state;
5021 struct drm_crtc *crtc;
5022 struct drm_crtc_state *crtc_state;
5023
5024 mst_state = drm_atomic_get_mst_topology_state(state, mgr);
5025
5026 if (IS_ERR(mst_state))
5027 return -EINVAL;
5028
5029 list_for_each_entry(pos, &mst_state->vcpis, next) {
5030
5031 connector = pos->port->connector;
5032
5033 if (!connector)
5034 return -EINVAL;
5035
5036 conn_state = drm_atomic_get_connector_state(state, connector);
5037
5038 if (IS_ERR(conn_state))
5039 return PTR_ERR(conn_state);
5040
5041 crtc = conn_state->crtc;
5042
5043 if (!crtc)
5044 continue;
5045
5046 if (!drm_dp_mst_dsc_aux_for_port(pos->port))
5047 continue;
5048
5049 crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc);
5050
5051 if (IS_ERR(crtc_state))
5052 return PTR_ERR(crtc_state);
5053
5054 DRM_DEBUG_ATOMIC("[MST MGR:%p] Setting mode_changed flag on CRTC %p\n",
5055 mgr, crtc);
5056
5057 crtc_state->mode_changed = true;
5058 }
5059 return 0;
5060}
5061EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs);
5062
5063/**
5064 * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off
5065 * @state: Pointer to the new drm_atomic_state
5066 * @port: Pointer to the affected MST Port
5067 * @pbn: Newly recalculated bw required for link with DSC enabled
5068 * @pbn_div: Divider to calculate correct number of pbn per slot
5069 * @enable: Boolean flag to enable or disable DSC on the port
5070 *
5071 * This function enables DSC on the given Port
5072 * by recalculating its vcpi from pbn provided
5073 * and sets dsc_enable flag to keep track of which
5074 * ports have DSC enabled
5075 *
5076 */
5077int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
5078 struct drm_dp_mst_port *port,
5079 int pbn, int pbn_div,
5080 bool enable)
5081{
5082 struct drm_dp_mst_topology_state *mst_state;
5083 struct drm_dp_vcpi_allocation *pos;
5084 bool found = false;
5085 int vcpi = 0;
5086
5087 mst_state = drm_atomic_get_mst_topology_state(state, port->mgr);
5088
5089 if (IS_ERR(mst_state))
5090 return PTR_ERR(mst_state);
5091
5092 list_for_each_entry(pos, &mst_state->vcpis, next) {
5093 if (pos->port == port) {
5094 found = true;
5095 break;
5096 }
5097 }
5098
5099 if (!found) {
5100 DRM_DEBUG_ATOMIC("[MST PORT:%p] Couldn't find VCPI allocation in mst state %p\n",
5101 port, mst_state);
5102 return -EINVAL;
5103 }
5104
5105 if (pos->dsc_enabled == enable) {
5106 DRM_DEBUG_ATOMIC("[MST PORT:%p] DSC flag is already set to %d, returning %d VCPI slots\n",
5107 port, enable, pos->vcpi);
5108 vcpi = pos->vcpi;
5109 }
5110
5111 if (enable) {
5112 vcpi = drm_dp_atomic_find_vcpi_slots(state, port->mgr, port, pbn, pbn_div);
5113 DRM_DEBUG_ATOMIC("[MST PORT:%p] Enabling DSC flag, reallocating %d VCPI slots on the port\n",
5114 port, vcpi);
5115 if (vcpi < 0)
5116 return -EINVAL;
5117 }
5118
5119 pos->dsc_enabled = enable;
5120
5121 return vcpi;
5122}
5123EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc);
5124/**
5125 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
5126 * atomic update is valid
5127 * @state: Pointer to the new &struct drm_dp_mst_topology_state
5128 *
5129 * Checks the given topology state for an atomic update to ensure that it's
5130 * valid. This includes checking whether there's enough bandwidth to support
5131 * the new VCPI allocations in the atomic update.
5132 *
5133 * Any atomic drivers supporting DP MST must make sure to call this after
5134 * checking the rest of their state in their
5135 * &drm_mode_config_funcs.atomic_check() callback.
5136 *
5137 * See also:
5138 * drm_dp_atomic_find_vcpi_slots()
5139 * drm_dp_atomic_release_vcpi_slots()
5140 *
5141 * Returns:
5142 *
5143 * 0 if the new state is valid, negative error code otherwise.
5144 */
5145int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
5146{
5147 struct drm_dp_mst_topology_mgr *mgr;
5148 struct drm_dp_mst_topology_state *mst_state;
5149 int i, ret = 0;
5150
5151 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
5152 if (!mgr->mst_state)
5153 continue;
5154
5155 ret = drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr, mst_state);
5156 if (ret)
5157 break;
5158
5159 mutex_lock(&mgr->lock);
5160 ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary,
5161 mst_state);
5162 mutex_unlock(&mgr->lock);
5163 if (ret < 0)
5164 break;
5165 else
5166 ret = 0;
5167 }
5168
5169 return ret;
5170}
5171EXPORT_SYMBOL(drm_dp_mst_atomic_check);
5172
5173const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
5174 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
5175 .atomic_destroy_state = drm_dp_mst_destroy_state,
5176};
5177EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
5178
5179/**
5180 * drm_atomic_get_mst_topology_state: get MST topology state
5181 *
5182 * @state: global atomic state
5183 * @mgr: MST topology manager, also the private object in this case
5184 *
5185 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
5186 * state vtable so that the private object state returned is that of a MST
5187 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
5188 * to care of the locking, so warn if don't hold the connection_mutex.
5189 *
5190 * RETURNS:
5191 *
5192 * The MST topology state or error pointer.
5193 */
5194struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
5195 struct drm_dp_mst_topology_mgr *mgr)
5196{
5197 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
5198}
5199EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
5200
5201/**
5202 * drm_dp_mst_topology_mgr_init - initialise a topology manager
5203 * @mgr: manager struct to initialise
5204 * @dev: device providing this structure - for i2c addition.
5205 * @aux: DP helper aux channel to talk to this device
5206 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
5207 * @max_payloads: maximum number of payloads this GPU can source
5208 * @conn_base_id: the connector object ID the MST device is connected to.
5209 *
5210 * Return 0 for success, or negative error code on failure
5211 */
5212int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
5213 struct drm_device *dev, struct drm_dp_aux *aux,
5214 int max_dpcd_transaction_bytes,
5215 int max_payloads, int conn_base_id)
5216{
5217 struct drm_dp_mst_topology_state *mst_state;
5218
5219 mutex_init(&mgr->lock);
5220 mutex_init(&mgr->qlock);
5221 mutex_init(&mgr->payload_lock);
5222 mutex_init(&mgr->delayed_destroy_lock);
5223 mutex_init(&mgr->up_req_lock);
5224 mutex_init(&mgr->probe_lock);
5225#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5226 mutex_init(&mgr->topology_ref_history_lock);
5227#endif
5228 INIT_LIST_HEAD(&mgr->tx_msg_downq);
5229 INIT_LIST_HEAD(&mgr->destroy_port_list);
5230 INIT_LIST_HEAD(&mgr->destroy_branch_device_list);
5231 INIT_LIST_HEAD(&mgr->up_req_list);
5232
5233 /*
5234 * delayed_destroy_work will be queued on a dedicated WQ, so that any
5235 * requeuing will be also flushed when deiniting the topology manager.
5236 */
5237 mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0);
5238 if (mgr->delayed_destroy_wq == NULL)
5239 return -ENOMEM;
5240
5241 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
5242 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
5243 INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work);
5244 INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work);
5245 init_waitqueue_head(&mgr->tx_waitq);
5246 mgr->dev = dev;
5247 mgr->aux = aux;
5248 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
5249 mgr->max_payloads = max_payloads;
5250 mgr->conn_base_id = conn_base_id;
5251 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
5252 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
5253 return -EINVAL;
5254 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
5255 if (!mgr->payloads)
5256 return -ENOMEM;
5257 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
5258 if (!mgr->proposed_vcpis)
5259 return -ENOMEM;
5260 set_bit(0, &mgr->payload_mask);
5261
5262 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
5263 if (mst_state == NULL)
5264 return -ENOMEM;
5265
5266 mst_state->mgr = mgr;
5267 INIT_LIST_HEAD(&mst_state->vcpis);
5268
5269 drm_atomic_private_obj_init(dev, &mgr->base,
5270 &mst_state->base,
5271 &drm_dp_mst_topology_state_funcs);
5272
5273 return 0;
5274}
5275EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
5276
5277/**
5278 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
5279 * @mgr: manager to destroy
5280 */
5281void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
5282{
5283 drm_dp_mst_topology_mgr_set_mst(mgr, false);
5284 flush_work(&mgr->work);
5285 /* The following will also drain any requeued work on the WQ. */
5286 if (mgr->delayed_destroy_wq) {
5287 destroy_workqueue(mgr->delayed_destroy_wq);
5288 mgr->delayed_destroy_wq = NULL;
5289 }
5290 mutex_lock(&mgr->payload_lock);
5291 kfree(mgr->payloads);
5292 mgr->payloads = NULL;
5293 kfree(mgr->proposed_vcpis);
5294 mgr->proposed_vcpis = NULL;
5295 mutex_unlock(&mgr->payload_lock);
5296 mgr->dev = NULL;
5297 mgr->aux = NULL;
5298 drm_atomic_private_obj_fini(&mgr->base);
5299 mgr->funcs = NULL;
5300
5301 mutex_destroy(&mgr->delayed_destroy_lock);
5302 mutex_destroy(&mgr->payload_lock);
5303 mutex_destroy(&mgr->qlock);
5304 mutex_destroy(&mgr->lock);
5305 mutex_destroy(&mgr->up_req_lock);
5306 mutex_destroy(&mgr->probe_lock);
5307#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5308 mutex_destroy(&mgr->topology_ref_history_lock);
5309#endif
5310}
5311EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
5312
5313static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
5314{
5315 int i;
5316
5317 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
5318 return false;
5319
5320 for (i = 0; i < num - 1; i++) {
5321 if (msgs[i].flags & I2C_M_RD ||
5322 msgs[i].len > 0xff)
5323 return false;
5324 }
5325
5326 return msgs[num - 1].flags & I2C_M_RD &&
5327 msgs[num - 1].len <= 0xff;
5328}
5329
5330/* I2C device */
5331static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
5332 int num)
5333{
5334 struct drm_dp_aux *aux = adapter->algo_data;
5335 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
5336 struct drm_dp_mst_branch *mstb;
5337 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5338 unsigned int i;
5339 struct drm_dp_sideband_msg_req_body msg;
5340 struct drm_dp_sideband_msg_tx *txmsg = NULL;
5341 int ret;
5342
5343 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
5344 if (!mstb)
5345 return -EREMOTEIO;
5346
5347 if (!remote_i2c_read_ok(msgs, num)) {
5348 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
5349 ret = -EIO;
5350 goto out;
5351 }
5352
5353 memset(&msg, 0, sizeof(msg));
5354 msg.req_type = DP_REMOTE_I2C_READ;
5355 msg.u.i2c_read.num_transactions = num - 1;
5356 msg.u.i2c_read.port_number = port->port_num;
5357 for (i = 0; i < num - 1; i++) {
5358 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
5359 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
5360 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
5361 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
5362 }
5363 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
5364 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
5365
5366 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5367 if (!txmsg) {
5368 ret = -ENOMEM;
5369 goto out;
5370 }
5371
5372 txmsg->dst = mstb;
5373 drm_dp_encode_sideband_req(&msg, txmsg);
5374
5375 drm_dp_queue_down_tx(mgr, txmsg);
5376
5377 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5378 if (ret > 0) {
5379
5380 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5381 ret = -EREMOTEIO;
5382 goto out;
5383 }
5384 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
5385 ret = -EIO;
5386 goto out;
5387 }
5388 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
5389 ret = num;
5390 }
5391out:
5392 kfree(txmsg);
5393 drm_dp_mst_topology_put_mstb(mstb);
5394 return ret;
5395}
5396
5397static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
5398{
5399 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
5400 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
5401 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
5402 I2C_FUNC_10BIT_ADDR;
5403}
5404
5405static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
5406 .functionality = drm_dp_mst_i2c_functionality,
5407 .master_xfer = drm_dp_mst_i2c_xfer,
5408};
5409
5410/**
5411 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
5412 * @port: The port to add the I2C bus on
5413 *
5414 * Returns 0 on success or a negative error code on failure.
5415 */
5416static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port)
5417{
5418 struct drm_dp_aux *aux = &port->aux;
5419 struct device *parent_dev = port->mgr->dev->dev;
5420
5421 aux->ddc.algo = &drm_dp_mst_i2c_algo;
5422 aux->ddc.algo_data = aux;
5423 aux->ddc.retries = 3;
5424
5425 aux->ddc.class = I2C_CLASS_DDC;
5426 aux->ddc.owner = THIS_MODULE;
5427 /* FIXME: set the kdev of the port's connector as parent */
5428 aux->ddc.dev.parent = parent_dev;
5429 aux->ddc.dev.of_node = parent_dev->of_node;
5430
5431 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev),
5432 sizeof(aux->ddc.name));
5433
5434 return i2c_add_adapter(&aux->ddc);
5435}
5436
5437/**
5438 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
5439 * @port: The port to remove the I2C bus from
5440 */
5441static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port)
5442{
5443 i2c_del_adapter(&port->aux.ddc);
5444}
5445
5446/**
5447 * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device
5448 * @port: The port to check
5449 *
5450 * A single physical MST hub object can be represented in the topology
5451 * by multiple branches, with virtual ports between those branches.
5452 *
5453 * As of DP1.4, An MST hub with internal (virtual) ports must expose
5454 * certain DPCD registers over those ports. See sections 2.6.1.1.1
5455 * and 2.6.1.1.2 of Display Port specification v1.4 for details.
5456 *
5457 * May acquire mgr->lock
5458 *
5459 * Returns:
5460 * true if the port is a virtual DP peer device, false otherwise
5461 */
5462static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port)
5463{
5464 struct drm_dp_mst_port *downstream_port;
5465
5466 if (!port || port->dpcd_rev < DP_DPCD_REV_14)
5467 return false;
5468
5469 /* Virtual DP Sink (Internal Display Panel) */
5470 if (port->port_num >= 8)
5471 return true;
5472
5473 /* DP-to-HDMI Protocol Converter */
5474 if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV &&
5475 !port->mcs &&
5476 port->ldps)
5477 return true;
5478
5479 /* DP-to-DP */
5480 mutex_lock(&port->mgr->lock);
5481 if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
5482 port->mstb &&
5483 port->mstb->num_ports == 2) {
5484 list_for_each_entry(downstream_port, &port->mstb->ports, next) {
5485 if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK &&
5486 !downstream_port->input) {
5487 mutex_unlock(&port->mgr->lock);
5488 return true;
5489 }
5490 }
5491 }
5492 mutex_unlock(&port->mgr->lock);
5493
5494 return false;
5495}
5496
5497/**
5498 * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
5499 * @port: The port to check. A leaf of the MST tree with an attached display.
5500 *
5501 * Depending on the situation, DSC may be enabled via the endpoint aux,
5502 * the immediately upstream aux, or the connector's physical aux.
5503 *
5504 * This is both the correct aux to read DSC_CAPABILITY and the
5505 * correct aux to write DSC_ENABLED.
5506 *
5507 * This operation can be expensive (up to four aux reads), so
5508 * the caller should cache the return.
5509 *
5510 * Returns:
5511 * NULL if DSC cannot be enabled on this port, otherwise the aux device
5512 */
5513struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
5514{
5515 struct drm_dp_mst_port *immediate_upstream_port;
5516 struct drm_dp_mst_port *fec_port;
5517 struct drm_dp_desc desc = {};
5518 u8 endpoint_fec;
5519 u8 endpoint_dsc;
5520
5521 if (!port)
5522 return NULL;
5523
5524 if (port->parent->port_parent)
5525 immediate_upstream_port = port->parent->port_parent;
5526 else
5527 immediate_upstream_port = NULL;
5528
5529 fec_port = immediate_upstream_port;
5530 while (fec_port) {
5531 /*
5532 * Each physical link (i.e. not a virtual port) between the
5533 * output and the primary device must support FEC
5534 */
5535 if (!drm_dp_mst_is_virtual_dpcd(fec_port) &&
5536 !fec_port->fec_capable)
5537 return NULL;
5538
5539 fec_port = fec_port->parent->port_parent;
5540 }
5541
5542 /* DP-to-DP peer device */
5543 if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) {
5544 u8 upstream_dsc;
5545
5546 if (drm_dp_dpcd_read(&port->aux,
5547 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5548 return NULL;
5549 if (drm_dp_dpcd_read(&port->aux,
5550 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5551 return NULL;
5552 if (drm_dp_dpcd_read(&immediate_upstream_port->aux,
5553 DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
5554 return NULL;
5555
5556 /* Enpoint decompression with DP-to-DP peer device */
5557 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5558 (endpoint_fec & DP_FEC_CAPABLE) &&
5559 (upstream_dsc & 0x2) /* DSC passthrough */)
5560 return &port->aux;
5561
5562 /* Virtual DPCD decompression with DP-to-DP peer device */
5563 return &immediate_upstream_port->aux;
5564 }
5565
5566 /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */
5567 if (drm_dp_mst_is_virtual_dpcd(port))
5568 return &port->aux;
5569
5570 /*
5571 * Synaptics quirk
5572 * Applies to ports for which:
5573 * - Physical aux has Synaptics OUI
5574 * - DPv1.4 or higher
5575 * - Port is on primary branch device
5576 * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG)
5577 */
5578 if (drm_dp_read_desc(port->mgr->aux, &desc, true))
5579 return NULL;
5580
5581 if (drm_dp_has_quirk(&desc, 0,
5582 DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) &&
5583 port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 &&
5584 port->parent == port->mgr->mst_primary) {
5585 u8 downstreamport;
5586
5587 if (drm_dp_dpcd_read(&port->aux, DP_DOWNSTREAMPORT_PRESENT,
5588 &downstreamport, 1) < 0)
5589 return NULL;
5590
5591 if ((downstreamport & DP_DWN_STRM_PORT_PRESENT) &&
5592 ((downstreamport & DP_DWN_STRM_PORT_TYPE_MASK)
5593 != DP_DWN_STRM_PORT_TYPE_ANALOG))
5594 return port->mgr->aux;
5595 }
5596
5597 /*
5598 * The check below verifies if the MST sink
5599 * connected to the GPU is capable of DSC -
5600 * therefore the endpoint needs to be
5601 * both DSC and FEC capable.
5602 */
5603 if (drm_dp_dpcd_read(&port->aux,
5604 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5605 return NULL;
5606 if (drm_dp_dpcd_read(&port->aux,
5607 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5608 return NULL;
5609 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5610 (endpoint_fec & DP_FEC_CAPABLE))
5611 return &port->aux;
5612
5613 return NULL;
5614}
5615EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);
1/*
2 * Copyright © 2014 Red Hat
3 *
4 * Permission to use, copy, modify, distribute, and sell this software and its
5 * documentation for any purpose is hereby granted without fee, provided that
6 * the above copyright notice appear in all copies and that both that copyright
7 * notice and this permission notice appear in supporting documentation, and
8 * that the name of the copyright holders not be used in advertising or
9 * publicity pertaining to distribution of the software without specific,
10 * written prior permission. The copyright holders make no representations
11 * about the suitability of this software for any purpose. It is provided "as
12 * is" without express or implied warranty.
13 *
14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20 * OF THIS SOFTWARE.
21 */
22
23#include <linux/delay.h>
24#include <linux/errno.h>
25#include <linux/i2c.h>
26#include <linux/init.h>
27#include <linux/kernel.h>
28#include <linux/sched.h>
29#include <linux/seq_file.h>
30
31#include <drm/drm_atomic.h>
32#include <drm/drm_atomic_helper.h>
33#include <drm/drm_dp_mst_helper.h>
34#include <drm/drm_drv.h>
35#include <drm/drm_fixed.h>
36#include <drm/drm_print.h>
37#include <drm/drm_probe_helper.h>
38
39#include "drm_crtc_helper_internal.h"
40
41/**
42 * DOC: dp mst helper
43 *
44 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
45 * protocol. The helpers contain a topology manager and bandwidth manager.
46 * The helpers encapsulate the sending and received of sideband msgs.
47 */
48static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
49 char *buf);
50static int test_calc_pbn_mode(void);
51
52static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
53
54static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
55 int id,
56 struct drm_dp_payload *payload);
57
58static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
59 struct drm_dp_mst_port *port,
60 int offset, int size, u8 *bytes);
61static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
62 struct drm_dp_mst_port *port,
63 int offset, int size, u8 *bytes);
64
65static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
66 struct drm_dp_mst_branch *mstb);
67static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
68 struct drm_dp_mst_branch *mstb,
69 struct drm_dp_mst_port *port);
70static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
71 u8 *guid);
72
73static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
74static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
75static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
76
77#define DP_STR(x) [DP_ ## x] = #x
78
79static const char *drm_dp_mst_req_type_str(u8 req_type)
80{
81 static const char * const req_type_str[] = {
82 DP_STR(GET_MSG_TRANSACTION_VERSION),
83 DP_STR(LINK_ADDRESS),
84 DP_STR(CONNECTION_STATUS_NOTIFY),
85 DP_STR(ENUM_PATH_RESOURCES),
86 DP_STR(ALLOCATE_PAYLOAD),
87 DP_STR(QUERY_PAYLOAD),
88 DP_STR(RESOURCE_STATUS_NOTIFY),
89 DP_STR(CLEAR_PAYLOAD_ID_TABLE),
90 DP_STR(REMOTE_DPCD_READ),
91 DP_STR(REMOTE_DPCD_WRITE),
92 DP_STR(REMOTE_I2C_READ),
93 DP_STR(REMOTE_I2C_WRITE),
94 DP_STR(POWER_UP_PHY),
95 DP_STR(POWER_DOWN_PHY),
96 DP_STR(SINK_EVENT_NOTIFY),
97 DP_STR(QUERY_STREAM_ENC_STATUS),
98 };
99
100 if (req_type >= ARRAY_SIZE(req_type_str) ||
101 !req_type_str[req_type])
102 return "unknown";
103
104 return req_type_str[req_type];
105}
106
107#undef DP_STR
108#define DP_STR(x) [DP_NAK_ ## x] = #x
109
110static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
111{
112 static const char * const nak_reason_str[] = {
113 DP_STR(WRITE_FAILURE),
114 DP_STR(INVALID_READ),
115 DP_STR(CRC_FAILURE),
116 DP_STR(BAD_PARAM),
117 DP_STR(DEFER),
118 DP_STR(LINK_FAILURE),
119 DP_STR(NO_RESOURCES),
120 DP_STR(DPCD_FAIL),
121 DP_STR(I2C_NAK),
122 DP_STR(ALLOCATE_FAIL),
123 };
124
125 if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
126 !nak_reason_str[nak_reason])
127 return "unknown";
128
129 return nak_reason_str[nak_reason];
130}
131
132#undef DP_STR
133
134/* sideband msg handling */
135static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
136{
137 u8 bitmask = 0x80;
138 u8 bitshift = 7;
139 u8 array_index = 0;
140 int number_of_bits = num_nibbles * 4;
141 u8 remainder = 0;
142
143 while (number_of_bits != 0) {
144 number_of_bits--;
145 remainder <<= 1;
146 remainder |= (data[array_index] & bitmask) >> bitshift;
147 bitmask >>= 1;
148 bitshift--;
149 if (bitmask == 0) {
150 bitmask = 0x80;
151 bitshift = 7;
152 array_index++;
153 }
154 if ((remainder & 0x10) == 0x10)
155 remainder ^= 0x13;
156 }
157
158 number_of_bits = 4;
159 while (number_of_bits != 0) {
160 number_of_bits--;
161 remainder <<= 1;
162 if ((remainder & 0x10) != 0)
163 remainder ^= 0x13;
164 }
165
166 return remainder;
167}
168
169static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
170{
171 u8 bitmask = 0x80;
172 u8 bitshift = 7;
173 u8 array_index = 0;
174 int number_of_bits = number_of_bytes * 8;
175 u16 remainder = 0;
176
177 while (number_of_bits != 0) {
178 number_of_bits--;
179 remainder <<= 1;
180 remainder |= (data[array_index] & bitmask) >> bitshift;
181 bitmask >>= 1;
182 bitshift--;
183 if (bitmask == 0) {
184 bitmask = 0x80;
185 bitshift = 7;
186 array_index++;
187 }
188 if ((remainder & 0x100) == 0x100)
189 remainder ^= 0xd5;
190 }
191
192 number_of_bits = 8;
193 while (number_of_bits != 0) {
194 number_of_bits--;
195 remainder <<= 1;
196 if ((remainder & 0x100) != 0)
197 remainder ^= 0xd5;
198 }
199
200 return remainder & 0xff;
201}
202static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
203{
204 u8 size = 3;
205 size += (hdr->lct / 2);
206 return size;
207}
208
209static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
210 u8 *buf, int *len)
211{
212 int idx = 0;
213 int i;
214 u8 crc4;
215 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
216 for (i = 0; i < (hdr->lct / 2); i++)
217 buf[idx++] = hdr->rad[i];
218 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
219 (hdr->msg_len & 0x3f);
220 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
221
222 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
223 buf[idx - 1] |= (crc4 & 0xf);
224
225 *len = idx;
226}
227
228static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
229 u8 *buf, int buflen, u8 *hdrlen)
230{
231 u8 crc4;
232 u8 len;
233 int i;
234 u8 idx;
235 if (buf[0] == 0)
236 return false;
237 len = 3;
238 len += ((buf[0] & 0xf0) >> 4) / 2;
239 if (len > buflen)
240 return false;
241 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
242
243 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
244 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
245 return false;
246 }
247
248 hdr->lct = (buf[0] & 0xf0) >> 4;
249 hdr->lcr = (buf[0] & 0xf);
250 idx = 1;
251 for (i = 0; i < (hdr->lct / 2); i++)
252 hdr->rad[i] = buf[idx++];
253 hdr->broadcast = (buf[idx] >> 7) & 0x1;
254 hdr->path_msg = (buf[idx] >> 6) & 0x1;
255 hdr->msg_len = buf[idx] & 0x3f;
256 idx++;
257 hdr->somt = (buf[idx] >> 7) & 0x1;
258 hdr->eomt = (buf[idx] >> 6) & 0x1;
259 hdr->seqno = (buf[idx] >> 4) & 0x1;
260 idx++;
261 *hdrlen = idx;
262 return true;
263}
264
265static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
266 struct drm_dp_sideband_msg_tx *raw)
267{
268 int idx = 0;
269 int i;
270 u8 *buf = raw->msg;
271 buf[idx++] = req->req_type & 0x7f;
272
273 switch (req->req_type) {
274 case DP_ENUM_PATH_RESOURCES:
275 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
276 idx++;
277 break;
278 case DP_ALLOCATE_PAYLOAD:
279 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
280 (req->u.allocate_payload.number_sdp_streams & 0xf);
281 idx++;
282 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
283 idx++;
284 buf[idx] = (req->u.allocate_payload.pbn >> 8);
285 idx++;
286 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
287 idx++;
288 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
289 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
290 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
291 idx++;
292 }
293 if (req->u.allocate_payload.number_sdp_streams & 1) {
294 i = req->u.allocate_payload.number_sdp_streams - 1;
295 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
296 idx++;
297 }
298 break;
299 case DP_QUERY_PAYLOAD:
300 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
301 idx++;
302 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
303 idx++;
304 break;
305 case DP_REMOTE_DPCD_READ:
306 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
307 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
308 idx++;
309 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
310 idx++;
311 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
312 idx++;
313 buf[idx] = (req->u.dpcd_read.num_bytes);
314 idx++;
315 break;
316
317 case DP_REMOTE_DPCD_WRITE:
318 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
319 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
320 idx++;
321 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
322 idx++;
323 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
324 idx++;
325 buf[idx] = (req->u.dpcd_write.num_bytes);
326 idx++;
327 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
328 idx += req->u.dpcd_write.num_bytes;
329 break;
330 case DP_REMOTE_I2C_READ:
331 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
332 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
333 idx++;
334 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
335 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
336 idx++;
337 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
338 idx++;
339 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
340 idx += req->u.i2c_read.transactions[i].num_bytes;
341
342 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
343 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
344 idx++;
345 }
346 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
347 idx++;
348 buf[idx] = (req->u.i2c_read.num_bytes_read);
349 idx++;
350 break;
351
352 case DP_REMOTE_I2C_WRITE:
353 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
354 idx++;
355 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
356 idx++;
357 buf[idx] = (req->u.i2c_write.num_bytes);
358 idx++;
359 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
360 idx += req->u.i2c_write.num_bytes;
361 break;
362
363 case DP_POWER_DOWN_PHY:
364 case DP_POWER_UP_PHY:
365 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
366 idx++;
367 break;
368 }
369 raw->cur_len = idx;
370}
371
372static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
373{
374 u8 crc4;
375 crc4 = drm_dp_msg_data_crc4(msg, len);
376 msg[len] = crc4;
377}
378
379static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
380 struct drm_dp_sideband_msg_tx *raw)
381{
382 int idx = 0;
383 u8 *buf = raw->msg;
384
385 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
386
387 raw->cur_len = idx;
388}
389
390/* this adds a chunk of msg to the builder to get the final msg */
391static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
392 u8 *replybuf, u8 replybuflen, bool hdr)
393{
394 int ret;
395 u8 crc4;
396
397 if (hdr) {
398 u8 hdrlen;
399 struct drm_dp_sideband_msg_hdr recv_hdr;
400 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
401 if (ret == false) {
402 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
403 return false;
404 }
405
406 /*
407 * ignore out-of-order messages or messages that are part of a
408 * failed transaction
409 */
410 if (!recv_hdr.somt && !msg->have_somt)
411 return false;
412
413 /* get length contained in this portion */
414 msg->curchunk_len = recv_hdr.msg_len;
415 msg->curchunk_hdrlen = hdrlen;
416
417 /* we have already gotten an somt - don't bother parsing */
418 if (recv_hdr.somt && msg->have_somt)
419 return false;
420
421 if (recv_hdr.somt) {
422 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
423 msg->have_somt = true;
424 }
425 if (recv_hdr.eomt)
426 msg->have_eomt = true;
427
428 /* copy the bytes for the remainder of this header chunk */
429 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
430 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
431 } else {
432 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
433 msg->curchunk_idx += replybuflen;
434 }
435
436 if (msg->curchunk_idx >= msg->curchunk_len) {
437 /* do CRC */
438 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
439 /* copy chunk into bigger msg */
440 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
441 msg->curlen += msg->curchunk_len - 1;
442 }
443 return true;
444}
445
446static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
447 struct drm_dp_sideband_msg_reply_body *repmsg)
448{
449 int idx = 1;
450 int i;
451 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
452 idx += 16;
453 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
454 idx++;
455 if (idx > raw->curlen)
456 goto fail_len;
457 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
458 if (raw->msg[idx] & 0x80)
459 repmsg->u.link_addr.ports[i].input_port = 1;
460
461 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
462 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
463
464 idx++;
465 if (idx > raw->curlen)
466 goto fail_len;
467 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
468 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
469 if (repmsg->u.link_addr.ports[i].input_port == 0)
470 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
471 idx++;
472 if (idx > raw->curlen)
473 goto fail_len;
474 if (repmsg->u.link_addr.ports[i].input_port == 0) {
475 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
476 idx++;
477 if (idx > raw->curlen)
478 goto fail_len;
479 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
480 idx += 16;
481 if (idx > raw->curlen)
482 goto fail_len;
483 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
484 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
485 idx++;
486
487 }
488 if (idx > raw->curlen)
489 goto fail_len;
490 }
491
492 return true;
493fail_len:
494 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
495 return false;
496}
497
498static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
499 struct drm_dp_sideband_msg_reply_body *repmsg)
500{
501 int idx = 1;
502 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
503 idx++;
504 if (idx > raw->curlen)
505 goto fail_len;
506 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
507 idx++;
508 if (idx > raw->curlen)
509 goto fail_len;
510
511 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
512 return true;
513fail_len:
514 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
515 return false;
516}
517
518static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
519 struct drm_dp_sideband_msg_reply_body *repmsg)
520{
521 int idx = 1;
522 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
523 idx++;
524 if (idx > raw->curlen)
525 goto fail_len;
526 return true;
527fail_len:
528 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
529 return false;
530}
531
532static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
533 struct drm_dp_sideband_msg_reply_body *repmsg)
534{
535 int idx = 1;
536
537 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
538 idx++;
539 if (idx > raw->curlen)
540 goto fail_len;
541 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
542 idx++;
543 /* TODO check */
544 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
545 return true;
546fail_len:
547 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
548 return false;
549}
550
551static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
552 struct drm_dp_sideband_msg_reply_body *repmsg)
553{
554 int idx = 1;
555 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
556 idx++;
557 if (idx > raw->curlen)
558 goto fail_len;
559 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
560 idx += 2;
561 if (idx > raw->curlen)
562 goto fail_len;
563 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
564 idx += 2;
565 if (idx > raw->curlen)
566 goto fail_len;
567 return true;
568fail_len:
569 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
570 return false;
571}
572
573static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
574 struct drm_dp_sideband_msg_reply_body *repmsg)
575{
576 int idx = 1;
577 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
578 idx++;
579 if (idx > raw->curlen)
580 goto fail_len;
581 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
582 idx++;
583 if (idx > raw->curlen)
584 goto fail_len;
585 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
586 idx += 2;
587 if (idx > raw->curlen)
588 goto fail_len;
589 return true;
590fail_len:
591 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
592 return false;
593}
594
595static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
596 struct drm_dp_sideband_msg_reply_body *repmsg)
597{
598 int idx = 1;
599 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
600 idx++;
601 if (idx > raw->curlen)
602 goto fail_len;
603 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
604 idx += 2;
605 if (idx > raw->curlen)
606 goto fail_len;
607 return true;
608fail_len:
609 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
610 return false;
611}
612
613static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
614 struct drm_dp_sideband_msg_reply_body *repmsg)
615{
616 int idx = 1;
617
618 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
619 idx++;
620 if (idx > raw->curlen) {
621 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
622 idx, raw->curlen);
623 return false;
624 }
625 return true;
626}
627
628static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
629 struct drm_dp_sideband_msg_reply_body *msg)
630{
631 memset(msg, 0, sizeof(*msg));
632 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
633 msg->req_type = (raw->msg[0] & 0x7f);
634
635 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
636 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
637 msg->u.nak.reason = raw->msg[17];
638 msg->u.nak.nak_data = raw->msg[18];
639 return false;
640 }
641
642 switch (msg->req_type) {
643 case DP_LINK_ADDRESS:
644 return drm_dp_sideband_parse_link_address(raw, msg);
645 case DP_QUERY_PAYLOAD:
646 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
647 case DP_REMOTE_DPCD_READ:
648 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
649 case DP_REMOTE_DPCD_WRITE:
650 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
651 case DP_REMOTE_I2C_READ:
652 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
653 case DP_ENUM_PATH_RESOURCES:
654 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
655 case DP_ALLOCATE_PAYLOAD:
656 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
657 case DP_POWER_DOWN_PHY:
658 case DP_POWER_UP_PHY:
659 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
660 default:
661 DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type,
662 drm_dp_mst_req_type_str(msg->req_type));
663 return false;
664 }
665}
666
667static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
668 struct drm_dp_sideband_msg_req_body *msg)
669{
670 int idx = 1;
671
672 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
673 idx++;
674 if (idx > raw->curlen)
675 goto fail_len;
676
677 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
678 idx += 16;
679 if (idx > raw->curlen)
680 goto fail_len;
681
682 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
683 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
684 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
685 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
686 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
687 idx++;
688 return true;
689fail_len:
690 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
691 return false;
692}
693
694static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
695 struct drm_dp_sideband_msg_req_body *msg)
696{
697 int idx = 1;
698
699 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
700 idx++;
701 if (idx > raw->curlen)
702 goto fail_len;
703
704 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
705 idx += 16;
706 if (idx > raw->curlen)
707 goto fail_len;
708
709 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
710 idx++;
711 return true;
712fail_len:
713 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
714 return false;
715}
716
717static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
718 struct drm_dp_sideband_msg_req_body *msg)
719{
720 memset(msg, 0, sizeof(*msg));
721 msg->req_type = (raw->msg[0] & 0x7f);
722
723 switch (msg->req_type) {
724 case DP_CONNECTION_STATUS_NOTIFY:
725 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
726 case DP_RESOURCE_STATUS_NOTIFY:
727 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
728 default:
729 DRM_ERROR("Got unknown request 0x%02x (%s)\n", msg->req_type,
730 drm_dp_mst_req_type_str(msg->req_type));
731 return false;
732 }
733}
734
735static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
736{
737 struct drm_dp_sideband_msg_req_body req;
738
739 req.req_type = DP_REMOTE_DPCD_WRITE;
740 req.u.dpcd_write.port_number = port_num;
741 req.u.dpcd_write.dpcd_address = offset;
742 req.u.dpcd_write.num_bytes = num_bytes;
743 req.u.dpcd_write.bytes = bytes;
744 drm_dp_encode_sideband_req(&req, msg);
745
746 return 0;
747}
748
749static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
750{
751 struct drm_dp_sideband_msg_req_body req;
752
753 req.req_type = DP_LINK_ADDRESS;
754 drm_dp_encode_sideband_req(&req, msg);
755 return 0;
756}
757
758static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
759{
760 struct drm_dp_sideband_msg_req_body req;
761
762 req.req_type = DP_ENUM_PATH_RESOURCES;
763 req.u.port_num.port_number = port_num;
764 drm_dp_encode_sideband_req(&req, msg);
765 msg->path_msg = true;
766 return 0;
767}
768
769static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
770 u8 vcpi, uint16_t pbn,
771 u8 number_sdp_streams,
772 u8 *sdp_stream_sink)
773{
774 struct drm_dp_sideband_msg_req_body req;
775 memset(&req, 0, sizeof(req));
776 req.req_type = DP_ALLOCATE_PAYLOAD;
777 req.u.allocate_payload.port_number = port_num;
778 req.u.allocate_payload.vcpi = vcpi;
779 req.u.allocate_payload.pbn = pbn;
780 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
781 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
782 number_sdp_streams);
783 drm_dp_encode_sideband_req(&req, msg);
784 msg->path_msg = true;
785 return 0;
786}
787
788static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
789 int port_num, bool power_up)
790{
791 struct drm_dp_sideband_msg_req_body req;
792
793 if (power_up)
794 req.req_type = DP_POWER_UP_PHY;
795 else
796 req.req_type = DP_POWER_DOWN_PHY;
797
798 req.u.port_num.port_number = port_num;
799 drm_dp_encode_sideband_req(&req, msg);
800 msg->path_msg = true;
801 return 0;
802}
803
804static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
805 struct drm_dp_vcpi *vcpi)
806{
807 int ret, vcpi_ret;
808
809 mutex_lock(&mgr->payload_lock);
810 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
811 if (ret > mgr->max_payloads) {
812 ret = -EINVAL;
813 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
814 goto out_unlock;
815 }
816
817 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
818 if (vcpi_ret > mgr->max_payloads) {
819 ret = -EINVAL;
820 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
821 goto out_unlock;
822 }
823
824 set_bit(ret, &mgr->payload_mask);
825 set_bit(vcpi_ret, &mgr->vcpi_mask);
826 vcpi->vcpi = vcpi_ret + 1;
827 mgr->proposed_vcpis[ret - 1] = vcpi;
828out_unlock:
829 mutex_unlock(&mgr->payload_lock);
830 return ret;
831}
832
833static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
834 int vcpi)
835{
836 int i;
837 if (vcpi == 0)
838 return;
839
840 mutex_lock(&mgr->payload_lock);
841 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
842 clear_bit(vcpi - 1, &mgr->vcpi_mask);
843
844 for (i = 0; i < mgr->max_payloads; i++) {
845 if (mgr->proposed_vcpis[i])
846 if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
847 mgr->proposed_vcpis[i] = NULL;
848 clear_bit(i + 1, &mgr->payload_mask);
849 }
850 }
851 mutex_unlock(&mgr->payload_lock);
852}
853
854static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
855 struct drm_dp_sideband_msg_tx *txmsg)
856{
857 unsigned int state;
858
859 /*
860 * All updates to txmsg->state are protected by mgr->qlock, and the two
861 * cases we check here are terminal states. For those the barriers
862 * provided by the wake_up/wait_event pair are enough.
863 */
864 state = READ_ONCE(txmsg->state);
865 return (state == DRM_DP_SIDEBAND_TX_RX ||
866 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
867}
868
869static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
870 struct drm_dp_sideband_msg_tx *txmsg)
871{
872 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
873 int ret;
874
875 ret = wait_event_timeout(mgr->tx_waitq,
876 check_txmsg_state(mgr, txmsg),
877 (4 * HZ));
878 mutex_lock(&mstb->mgr->qlock);
879 if (ret > 0) {
880 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
881 ret = -EIO;
882 goto out;
883 }
884 } else {
885 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
886
887 /* dump some state */
888 ret = -EIO;
889
890 /* remove from q */
891 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
892 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
893 list_del(&txmsg->next);
894 }
895
896 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
897 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
898 mstb->tx_slots[txmsg->seqno] = NULL;
899 }
900 }
901out:
902 mutex_unlock(&mgr->qlock);
903
904 return ret;
905}
906
907static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
908{
909 struct drm_dp_mst_branch *mstb;
910
911 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
912 if (!mstb)
913 return NULL;
914
915 mstb->lct = lct;
916 if (lct > 1)
917 memcpy(mstb->rad, rad, lct / 2);
918 INIT_LIST_HEAD(&mstb->ports);
919 kref_init(&mstb->topology_kref);
920 kref_init(&mstb->malloc_kref);
921 return mstb;
922}
923
924static void drm_dp_free_mst_branch_device(struct kref *kref)
925{
926 struct drm_dp_mst_branch *mstb =
927 container_of(kref, struct drm_dp_mst_branch, malloc_kref);
928
929 if (mstb->port_parent)
930 drm_dp_mst_put_port_malloc(mstb->port_parent);
931
932 kfree(mstb);
933}
934
935/**
936 * DOC: Branch device and port refcounting
937 *
938 * Topology refcount overview
939 * ~~~~~~~~~~~~~~~~~~~~~~~~~~
940 *
941 * The refcounting schemes for &struct drm_dp_mst_branch and &struct
942 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
943 * two different kinds of refcounts: topology refcounts, and malloc refcounts.
944 *
945 * Topology refcounts are not exposed to drivers, and are handled internally
946 * by the DP MST helpers. The helpers use them in order to prevent the
947 * in-memory topology state from being changed in the middle of critical
948 * operations like changing the internal state of payload allocations. This
949 * means each branch and port will be considered to be connected to the rest
950 * of the topology until its topology refcount reaches zero. Additionally,
951 * for ports this means that their associated &struct drm_connector will stay
952 * registered with userspace until the port's refcount reaches 0.
953 *
954 * Malloc refcount overview
955 * ~~~~~~~~~~~~~~~~~~~~~~~~
956 *
957 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct
958 * drm_dp_mst_branch allocated even after all of its topology references have
959 * been dropped, so that the driver or MST helpers can safely access each
960 * branch's last known state before it was disconnected from the topology.
961 * When the malloc refcount of a port or branch reaches 0, the memory
962 * allocation containing the &struct drm_dp_mst_branch or &struct
963 * drm_dp_mst_port respectively will be freed.
964 *
965 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
966 * to drivers. As of writing this documentation, there are no drivers that
967 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
968 * helpers. Exposing this API to drivers in a race-free manner would take more
969 * tweaking of the refcounting scheme, however patches are welcome provided
970 * there is a legitimate driver usecase for this.
971 *
972 * Refcount relationships in a topology
973 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
974 *
975 * Let's take a look at why the relationship between topology and malloc
976 * refcounts is designed the way it is.
977 *
978 * .. kernel-figure:: dp-mst/topology-figure-1.dot
979 *
980 * An example of topology and malloc refs in a DP MST topology with two
981 * active payloads. Topology refcount increments are indicated by solid
982 * lines, and malloc refcount increments are indicated by dashed lines.
983 * Each starts from the branch which incremented the refcount, and ends at
984 * the branch to which the refcount belongs to, i.e. the arrow points the
985 * same way as the C pointers used to reference a structure.
986 *
987 * As you can see in the above figure, every branch increments the topology
988 * refcount of its children, and increments the malloc refcount of its
989 * parent. Additionally, every payload increments the malloc refcount of its
990 * assigned port by 1.
991 *
992 * So, what would happen if MSTB #3 from the above figure was unplugged from
993 * the system, but the driver hadn't yet removed payload #2 from port #3? The
994 * topology would start to look like the figure below.
995 *
996 * .. kernel-figure:: dp-mst/topology-figure-2.dot
997 *
998 * Ports and branch devices which have been released from memory are
999 * colored grey, and references which have been removed are colored red.
1000 *
1001 * Whenever a port or branch device's topology refcount reaches zero, it will
1002 * decrement the topology refcounts of all its children, the malloc refcount
1003 * of its parent, and finally its own malloc refcount. For MSTB #4 and port
1004 * #4, this means they both have been disconnected from the topology and freed
1005 * from memory. But, because payload #2 is still holding a reference to port
1006 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
1007 * is still accessible from memory. This also means port #3 has not yet
1008 * decremented the malloc refcount of MSTB #3, so its &struct
1009 * drm_dp_mst_branch will also stay allocated in memory until port #3's
1010 * malloc refcount reaches 0.
1011 *
1012 * This relationship is necessary because in order to release payload #2, we
1013 * need to be able to figure out the last relative of port #3 that's still
1014 * connected to the topology. In this case, we would travel up the topology as
1015 * shown below.
1016 *
1017 * .. kernel-figure:: dp-mst/topology-figure-3.dot
1018 *
1019 * And finally, remove payload #2 by communicating with port #2 through
1020 * sideband transactions.
1021 */
1022
1023/**
1024 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
1025 * device
1026 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
1027 *
1028 * Increments &drm_dp_mst_branch.malloc_kref. When
1029 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1030 * will be released and @mstb may no longer be used.
1031 *
1032 * See also: drm_dp_mst_put_mstb_malloc()
1033 */
1034static void
1035drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
1036{
1037 kref_get(&mstb->malloc_kref);
1038 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
1039}
1040
1041/**
1042 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
1043 * device
1044 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
1045 *
1046 * Decrements &drm_dp_mst_branch.malloc_kref. When
1047 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1048 * will be released and @mstb may no longer be used.
1049 *
1050 * See also: drm_dp_mst_get_mstb_malloc()
1051 */
1052static void
1053drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
1054{
1055 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
1056 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
1057}
1058
1059static void drm_dp_free_mst_port(struct kref *kref)
1060{
1061 struct drm_dp_mst_port *port =
1062 container_of(kref, struct drm_dp_mst_port, malloc_kref);
1063
1064 drm_dp_mst_put_mstb_malloc(port->parent);
1065 kfree(port);
1066}
1067
1068/**
1069 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
1070 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of
1071 *
1072 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1073 * reaches 0, the memory allocation for @port will be released and @port may
1074 * no longer be used.
1075 *
1076 * Because @port could potentially be freed at any time by the DP MST helpers
1077 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
1078 * function, drivers that which to make use of &struct drm_dp_mst_port should
1079 * ensure that they grab at least one main malloc reference to their MST ports
1080 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
1081 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
1082 *
1083 * See also: drm_dp_mst_put_port_malloc()
1084 */
1085void
1086drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
1087{
1088 kref_get(&port->malloc_kref);
1089 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref));
1090}
1091EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
1092
1093/**
1094 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
1095 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
1096 *
1097 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1098 * reaches 0, the memory allocation for @port will be released and @port may
1099 * no longer be used.
1100 *
1101 * See also: drm_dp_mst_get_port_malloc()
1102 */
1103void
1104drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
1105{
1106 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
1107 kref_put(&port->malloc_kref, drm_dp_free_mst_port);
1108}
1109EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
1110
1111static void drm_dp_destroy_mst_branch_device(struct kref *kref)
1112{
1113 struct drm_dp_mst_branch *mstb =
1114 container_of(kref, struct drm_dp_mst_branch, topology_kref);
1115 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1116 struct drm_dp_mst_port *port, *tmp;
1117 bool wake_tx = false;
1118
1119 mutex_lock(&mgr->lock);
1120 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
1121 list_del(&port->next);
1122 drm_dp_mst_topology_put_port(port);
1123 }
1124 mutex_unlock(&mgr->lock);
1125
1126 /* drop any tx slots msg */
1127 mutex_lock(&mstb->mgr->qlock);
1128 if (mstb->tx_slots[0]) {
1129 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1130 mstb->tx_slots[0] = NULL;
1131 wake_tx = true;
1132 }
1133 if (mstb->tx_slots[1]) {
1134 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1135 mstb->tx_slots[1] = NULL;
1136 wake_tx = true;
1137 }
1138 mutex_unlock(&mstb->mgr->qlock);
1139
1140 if (wake_tx)
1141 wake_up_all(&mstb->mgr->tx_waitq);
1142
1143 drm_dp_mst_put_mstb_malloc(mstb);
1144}
1145
1146/**
1147 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1148 * branch device unless it's zero
1149 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
1150 *
1151 * Attempts to grab a topology reference to @mstb, if it hasn't yet been
1152 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
1153 * reached 0). Holding a topology reference implies that a malloc reference
1154 * will be held to @mstb as long as the user holds the topology reference.
1155 *
1156 * Care should be taken to ensure that the user has at least one malloc
1157 * reference to @mstb. If you already have a topology reference to @mstb, you
1158 * should use drm_dp_mst_topology_get_mstb() instead.
1159 *
1160 * See also:
1161 * drm_dp_mst_topology_get_mstb()
1162 * drm_dp_mst_topology_put_mstb()
1163 *
1164 * Returns:
1165 * * 1: A topology reference was grabbed successfully
1166 * * 0: @port is no longer in the topology, no reference was grabbed
1167 */
1168static int __must_check
1169drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
1170{
1171 int ret = kref_get_unless_zero(&mstb->topology_kref);
1172
1173 if (ret)
1174 DRM_DEBUG("mstb %p (%d)\n", mstb,
1175 kref_read(&mstb->topology_kref));
1176
1177 return ret;
1178}
1179
1180/**
1181 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
1182 * branch device
1183 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
1184 *
1185 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or
1186 * not it's already reached 0. This is only valid to use in scenarios where
1187 * you are already guaranteed to have at least one active topology reference
1188 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
1189 *
1190 * See also:
1191 * drm_dp_mst_topology_try_get_mstb()
1192 * drm_dp_mst_topology_put_mstb()
1193 */
1194static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
1195{
1196 WARN_ON(kref_read(&mstb->topology_kref) == 0);
1197 kref_get(&mstb->topology_kref);
1198 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1199}
1200
1201/**
1202 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
1203 * device
1204 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from
1205 *
1206 * Releases a topology reference from @mstb by decrementing
1207 * &drm_dp_mst_branch.topology_kref.
1208 *
1209 * See also:
1210 * drm_dp_mst_topology_try_get_mstb()
1211 * drm_dp_mst_topology_get_mstb()
1212 */
1213static void
1214drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
1215{
1216 DRM_DEBUG("mstb %p (%d)\n",
1217 mstb, kref_read(&mstb->topology_kref) - 1);
1218 kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
1219}
1220
1221static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
1222{
1223 struct drm_dp_mst_branch *mstb;
1224
1225 switch (old_pdt) {
1226 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1227 case DP_PEER_DEVICE_SST_SINK:
1228 /* remove i2c over sideband */
1229 drm_dp_mst_unregister_i2c_bus(&port->aux);
1230 break;
1231 case DP_PEER_DEVICE_MST_BRANCHING:
1232 mstb = port->mstb;
1233 port->mstb = NULL;
1234 drm_dp_mst_topology_put_mstb(mstb);
1235 break;
1236 }
1237}
1238
1239static void drm_dp_destroy_port(struct kref *kref)
1240{
1241 struct drm_dp_mst_port *port =
1242 container_of(kref, struct drm_dp_mst_port, topology_kref);
1243 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1244
1245 if (!port->input) {
1246 kfree(port->cached_edid);
1247
1248 /*
1249 * The only time we don't have a connector
1250 * on an output port is if the connector init
1251 * fails.
1252 */
1253 if (port->connector) {
1254 /* we can't destroy the connector here, as
1255 * we might be holding the mode_config.mutex
1256 * from an EDID retrieval */
1257
1258 mutex_lock(&mgr->destroy_connector_lock);
1259 list_add(&port->next, &mgr->destroy_connector_list);
1260 mutex_unlock(&mgr->destroy_connector_lock);
1261 schedule_work(&mgr->destroy_connector_work);
1262 return;
1263 }
1264 /* no need to clean up vcpi
1265 * as if we have no connector we never setup a vcpi */
1266 drm_dp_port_teardown_pdt(port, port->pdt);
1267 port->pdt = DP_PEER_DEVICE_NONE;
1268 }
1269 drm_dp_mst_put_port_malloc(port);
1270}
1271
1272/**
1273 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
1274 * port unless it's zero
1275 * @port: &struct drm_dp_mst_port to increment the topology refcount of
1276 *
1277 * Attempts to grab a topology reference to @port, if it hasn't yet been
1278 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
1279 * 0). Holding a topology reference implies that a malloc reference will be
1280 * held to @port as long as the user holds the topology reference.
1281 *
1282 * Care should be taken to ensure that the user has at least one malloc
1283 * reference to @port. If you already have a topology reference to @port, you
1284 * should use drm_dp_mst_topology_get_port() instead.
1285 *
1286 * See also:
1287 * drm_dp_mst_topology_get_port()
1288 * drm_dp_mst_topology_put_port()
1289 *
1290 * Returns:
1291 * * 1: A topology reference was grabbed successfully
1292 * * 0: @port is no longer in the topology, no reference was grabbed
1293 */
1294static int __must_check
1295drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
1296{
1297 int ret = kref_get_unless_zero(&port->topology_kref);
1298
1299 if (ret)
1300 DRM_DEBUG("port %p (%d)\n", port,
1301 kref_read(&port->topology_kref));
1302
1303 return ret;
1304}
1305
1306/**
1307 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
1308 * @port: The &struct drm_dp_mst_port to increment the topology refcount of
1309 *
1310 * Increments &drm_dp_mst_port.topology_refcount without checking whether or
1311 * not it's already reached 0. This is only valid to use in scenarios where
1312 * you are already guaranteed to have at least one active topology reference
1313 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
1314 *
1315 * See also:
1316 * drm_dp_mst_topology_try_get_port()
1317 * drm_dp_mst_topology_put_port()
1318 */
1319static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
1320{
1321 WARN_ON(kref_read(&port->topology_kref) == 0);
1322 kref_get(&port->topology_kref);
1323 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref));
1324}
1325
1326/**
1327 * drm_dp_mst_topology_put_port() - release a topology reference to a port
1328 * @port: The &struct drm_dp_mst_port to release the topology reference from
1329 *
1330 * Releases a topology reference from @port by decrementing
1331 * &drm_dp_mst_port.topology_kref.
1332 *
1333 * See also:
1334 * drm_dp_mst_topology_try_get_port()
1335 * drm_dp_mst_topology_get_port()
1336 */
1337static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
1338{
1339 DRM_DEBUG("port %p (%d)\n",
1340 port, kref_read(&port->topology_kref) - 1);
1341 kref_put(&port->topology_kref, drm_dp_destroy_port);
1342}
1343
1344static struct drm_dp_mst_branch *
1345drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
1346 struct drm_dp_mst_branch *to_find)
1347{
1348 struct drm_dp_mst_port *port;
1349 struct drm_dp_mst_branch *rmstb;
1350
1351 if (to_find == mstb)
1352 return mstb;
1353
1354 list_for_each_entry(port, &mstb->ports, next) {
1355 if (port->mstb) {
1356 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1357 port->mstb, to_find);
1358 if (rmstb)
1359 return rmstb;
1360 }
1361 }
1362 return NULL;
1363}
1364
1365static struct drm_dp_mst_branch *
1366drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
1367 struct drm_dp_mst_branch *mstb)
1368{
1369 struct drm_dp_mst_branch *rmstb = NULL;
1370
1371 mutex_lock(&mgr->lock);
1372 if (mgr->mst_primary) {
1373 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1374 mgr->mst_primary, mstb);
1375
1376 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
1377 rmstb = NULL;
1378 }
1379 mutex_unlock(&mgr->lock);
1380 return rmstb;
1381}
1382
1383static struct drm_dp_mst_port *
1384drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
1385 struct drm_dp_mst_port *to_find)
1386{
1387 struct drm_dp_mst_port *port, *mport;
1388
1389 list_for_each_entry(port, &mstb->ports, next) {
1390 if (port == to_find)
1391 return port;
1392
1393 if (port->mstb) {
1394 mport = drm_dp_mst_topology_get_port_validated_locked(
1395 port->mstb, to_find);
1396 if (mport)
1397 return mport;
1398 }
1399 }
1400 return NULL;
1401}
1402
1403static struct drm_dp_mst_port *
1404drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
1405 struct drm_dp_mst_port *port)
1406{
1407 struct drm_dp_mst_port *rport = NULL;
1408
1409 mutex_lock(&mgr->lock);
1410 if (mgr->mst_primary) {
1411 rport = drm_dp_mst_topology_get_port_validated_locked(
1412 mgr->mst_primary, port);
1413
1414 if (rport && !drm_dp_mst_topology_try_get_port(rport))
1415 rport = NULL;
1416 }
1417 mutex_unlock(&mgr->lock);
1418 return rport;
1419}
1420
1421static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
1422{
1423 struct drm_dp_mst_port *port;
1424 int ret;
1425
1426 list_for_each_entry(port, &mstb->ports, next) {
1427 if (port->port_num == port_num) {
1428 ret = drm_dp_mst_topology_try_get_port(port);
1429 return ret ? port : NULL;
1430 }
1431 }
1432
1433 return NULL;
1434}
1435
1436/*
1437 * calculate a new RAD for this MST branch device
1438 * if parent has an LCT of 2 then it has 1 nibble of RAD,
1439 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1440 */
1441static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1442 u8 *rad)
1443{
1444 int parent_lct = port->parent->lct;
1445 int shift = 4;
1446 int idx = (parent_lct - 1) / 2;
1447 if (parent_lct > 1) {
1448 memcpy(rad, port->parent->rad, idx + 1);
1449 shift = (parent_lct % 2) ? 4 : 0;
1450 } else
1451 rad[0] = 0;
1452
1453 rad[idx] |= port->port_num << shift;
1454 return parent_lct + 1;
1455}
1456
1457/*
1458 * return sends link address for new mstb
1459 */
1460static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
1461{
1462 int ret;
1463 u8 rad[6], lct;
1464 bool send_link = false;
1465 switch (port->pdt) {
1466 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1467 case DP_PEER_DEVICE_SST_SINK:
1468 /* add i2c over sideband */
1469 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1470 break;
1471 case DP_PEER_DEVICE_MST_BRANCHING:
1472 lct = drm_dp_calculate_rad(port, rad);
1473
1474 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1475 if (port->mstb) {
1476 port->mstb->mgr = port->mgr;
1477 port->mstb->port_parent = port;
1478 /*
1479 * Make sure this port's memory allocation stays
1480 * around until its child MSTB releases it
1481 */
1482 drm_dp_mst_get_port_malloc(port);
1483
1484 send_link = true;
1485 }
1486 break;
1487 }
1488 return send_link;
1489}
1490
1491/**
1492 * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
1493 * @aux: Fake sideband AUX CH
1494 * @offset: address of the (first) register to read
1495 * @buffer: buffer to store the register values
1496 * @size: number of bytes in @buffer
1497 *
1498 * Performs the same functionality for remote devices via
1499 * sideband messaging as drm_dp_dpcd_read() does for local
1500 * devices via actual AUX CH.
1501 *
1502 * Return: Number of bytes read, or negative error code on failure.
1503 */
1504ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
1505 unsigned int offset, void *buffer, size_t size)
1506{
1507 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
1508 aux);
1509
1510 return drm_dp_send_dpcd_read(port->mgr, port,
1511 offset, size, buffer);
1512}
1513
1514/**
1515 * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
1516 * @aux: Fake sideband AUX CH
1517 * @offset: address of the (first) register to write
1518 * @buffer: buffer containing the values to write
1519 * @size: number of bytes in @buffer
1520 *
1521 * Performs the same functionality for remote devices via
1522 * sideband messaging as drm_dp_dpcd_write() does for local
1523 * devices via actual AUX CH.
1524 *
1525 * Return: 0 on success, negative error code on failure.
1526 */
1527ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
1528 unsigned int offset, void *buffer, size_t size)
1529{
1530 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
1531 aux);
1532
1533 return drm_dp_send_dpcd_write(port->mgr, port,
1534 offset, size, buffer);
1535}
1536
1537static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
1538{
1539 int ret;
1540
1541 memcpy(mstb->guid, guid, 16);
1542
1543 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
1544 if (mstb->port_parent) {
1545 ret = drm_dp_send_dpcd_write(
1546 mstb->mgr,
1547 mstb->port_parent,
1548 DP_GUID,
1549 16,
1550 mstb->guid);
1551 } else {
1552
1553 ret = drm_dp_dpcd_write(
1554 mstb->mgr->aux,
1555 DP_GUID,
1556 mstb->guid,
1557 16);
1558 }
1559 }
1560}
1561
1562static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1563 int pnum,
1564 char *proppath,
1565 size_t proppath_size)
1566{
1567 int i;
1568 char temp[8];
1569 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1570 for (i = 0; i < (mstb->lct - 1); i++) {
1571 int shift = (i % 2) ? 0 : 4;
1572 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
1573 snprintf(temp, sizeof(temp), "-%d", port_num);
1574 strlcat(proppath, temp, proppath_size);
1575 }
1576 snprintf(temp, sizeof(temp), "-%d", pnum);
1577 strlcat(proppath, temp, proppath_size);
1578}
1579
1580/**
1581 * drm_dp_mst_connector_late_register() - Late MST connector registration
1582 * @connector: The MST connector
1583 * @port: The MST port for this connector
1584 *
1585 * Helper to register the remote aux device for this MST port. Drivers should
1586 * call this from their mst connector's late_register hook to enable MST aux
1587 * devices.
1588 *
1589 * Return: 0 on success, negative error code on failure.
1590 */
1591int drm_dp_mst_connector_late_register(struct drm_connector *connector,
1592 struct drm_dp_mst_port *port)
1593{
1594 DRM_DEBUG_KMS("registering %s remote bus for %s\n",
1595 port->aux.name, connector->kdev->kobj.name);
1596
1597 port->aux.dev = connector->kdev;
1598 return drm_dp_aux_register_devnode(&port->aux);
1599}
1600EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
1601
1602/**
1603 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
1604 * @connector: The MST connector
1605 * @port: The MST port for this connector
1606 *
1607 * Helper to unregister the remote aux device for this MST port, registered by
1608 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst
1609 * connector's early_unregister hook.
1610 */
1611void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
1612 struct drm_dp_mst_port *port)
1613{
1614 DRM_DEBUG_KMS("unregistering %s remote bus for %s\n",
1615 port->aux.name, connector->kdev->kobj.name);
1616 drm_dp_aux_unregister_devnode(&port->aux);
1617}
1618EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
1619
1620static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1621 struct drm_device *dev,
1622 struct drm_dp_link_addr_reply_port *port_msg)
1623{
1624 struct drm_dp_mst_port *port;
1625 bool ret;
1626 bool created = false;
1627 int old_pdt = 0;
1628 int old_ddps = 0;
1629
1630 port = drm_dp_get_port(mstb, port_msg->port_number);
1631 if (!port) {
1632 port = kzalloc(sizeof(*port), GFP_KERNEL);
1633 if (!port)
1634 return;
1635 kref_init(&port->topology_kref);
1636 kref_init(&port->malloc_kref);
1637 port->parent = mstb;
1638 port->port_num = port_msg->port_number;
1639 port->mgr = mstb->mgr;
1640 port->aux.name = "DPMST";
1641 port->aux.dev = dev->dev;
1642 port->aux.is_remote = true;
1643
1644 /*
1645 * Make sure the memory allocation for our parent branch stays
1646 * around until our own memory allocation is released
1647 */
1648 drm_dp_mst_get_mstb_malloc(mstb);
1649
1650 created = true;
1651 } else {
1652 old_pdt = port->pdt;
1653 old_ddps = port->ddps;
1654 }
1655
1656 port->pdt = port_msg->peer_device_type;
1657 port->input = port_msg->input_port;
1658 port->mcs = port_msg->mcs;
1659 port->ddps = port_msg->ddps;
1660 port->ldps = port_msg->legacy_device_plug_status;
1661 port->dpcd_rev = port_msg->dpcd_revision;
1662 port->num_sdp_streams = port_msg->num_sdp_streams;
1663 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1664
1665 /* manage mstb port lists with mgr lock - take a reference
1666 for this list */
1667 if (created) {
1668 mutex_lock(&mstb->mgr->lock);
1669 drm_dp_mst_topology_get_port(port);
1670 list_add(&port->next, &mstb->ports);
1671 mutex_unlock(&mstb->mgr->lock);
1672 }
1673
1674 if (old_ddps != port->ddps) {
1675 if (port->ddps) {
1676 if (!port->input) {
1677 drm_dp_send_enum_path_resources(mstb->mgr,
1678 mstb, port);
1679 }
1680 } else {
1681 port->available_pbn = 0;
1682 }
1683 }
1684
1685 if (old_pdt != port->pdt && !port->input) {
1686 drm_dp_port_teardown_pdt(port, old_pdt);
1687
1688 ret = drm_dp_port_setup_pdt(port);
1689 if (ret == true)
1690 drm_dp_send_link_address(mstb->mgr, port->mstb);
1691 }
1692
1693 if (created && !port->input) {
1694 char proppath[255];
1695
1696 build_mst_prop_path(mstb, port->port_num, proppath,
1697 sizeof(proppath));
1698 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr,
1699 port,
1700 proppath);
1701 if (!port->connector) {
1702 /* remove it from the port list */
1703 mutex_lock(&mstb->mgr->lock);
1704 list_del(&port->next);
1705 mutex_unlock(&mstb->mgr->lock);
1706 /* drop port list reference */
1707 drm_dp_mst_topology_put_port(port);
1708 goto out;
1709 }
1710 if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
1711 port->pdt == DP_PEER_DEVICE_SST_SINK) &&
1712 port->port_num >= DP_MST_LOGICAL_PORT_0) {
1713 port->cached_edid = drm_get_edid(port->connector,
1714 &port->aux.ddc);
1715 drm_connector_set_tile_property(port->connector);
1716 }
1717 (*mstb->mgr->cbs->register_connector)(port->connector);
1718 }
1719
1720out:
1721 /* put reference to this port */
1722 drm_dp_mst_topology_put_port(port);
1723}
1724
1725static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1726 struct drm_dp_connection_status_notify *conn_stat)
1727{
1728 struct drm_dp_mst_port *port;
1729 int old_pdt;
1730 int old_ddps;
1731 bool dowork = false;
1732 port = drm_dp_get_port(mstb, conn_stat->port_number);
1733 if (!port)
1734 return;
1735
1736 old_ddps = port->ddps;
1737 old_pdt = port->pdt;
1738 port->pdt = conn_stat->peer_device_type;
1739 port->mcs = conn_stat->message_capability_status;
1740 port->ldps = conn_stat->legacy_device_plug_status;
1741 port->ddps = conn_stat->displayport_device_plug_status;
1742
1743 if (old_ddps != port->ddps) {
1744 if (port->ddps) {
1745 dowork = true;
1746 } else {
1747 port->available_pbn = 0;
1748 }
1749 }
1750 if (old_pdt != port->pdt && !port->input) {
1751 drm_dp_port_teardown_pdt(port, old_pdt);
1752
1753 if (drm_dp_port_setup_pdt(port))
1754 dowork = true;
1755 }
1756
1757 drm_dp_mst_topology_put_port(port);
1758 if (dowork)
1759 queue_work(system_long_wq, &mstb->mgr->work);
1760
1761}
1762
1763static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1764 u8 lct, u8 *rad)
1765{
1766 struct drm_dp_mst_branch *mstb;
1767 struct drm_dp_mst_port *port;
1768 int i, ret;
1769 /* find the port by iterating down */
1770
1771 mutex_lock(&mgr->lock);
1772 mstb = mgr->mst_primary;
1773
1774 if (!mstb)
1775 goto out;
1776
1777 for (i = 0; i < lct - 1; i++) {
1778 int shift = (i % 2) ? 0 : 4;
1779 int port_num = (rad[i / 2] >> shift) & 0xf;
1780
1781 list_for_each_entry(port, &mstb->ports, next) {
1782 if (port->port_num == port_num) {
1783 mstb = port->mstb;
1784 if (!mstb) {
1785 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1786 goto out;
1787 }
1788
1789 break;
1790 }
1791 }
1792 }
1793 ret = drm_dp_mst_topology_try_get_mstb(mstb);
1794 if (!ret)
1795 mstb = NULL;
1796out:
1797 mutex_unlock(&mgr->lock);
1798 return mstb;
1799}
1800
1801static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1802 struct drm_dp_mst_branch *mstb,
1803 uint8_t *guid)
1804{
1805 struct drm_dp_mst_branch *found_mstb;
1806 struct drm_dp_mst_port *port;
1807
1808 if (memcmp(mstb->guid, guid, 16) == 0)
1809 return mstb;
1810
1811
1812 list_for_each_entry(port, &mstb->ports, next) {
1813 if (!port->mstb)
1814 continue;
1815
1816 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1817
1818 if (found_mstb)
1819 return found_mstb;
1820 }
1821
1822 return NULL;
1823}
1824
1825static struct drm_dp_mst_branch *
1826drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
1827 uint8_t *guid)
1828{
1829 struct drm_dp_mst_branch *mstb;
1830 int ret;
1831
1832 /* find the port by iterating down */
1833 mutex_lock(&mgr->lock);
1834
1835 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1836 if (mstb) {
1837 ret = drm_dp_mst_topology_try_get_mstb(mstb);
1838 if (!ret)
1839 mstb = NULL;
1840 }
1841
1842 mutex_unlock(&mgr->lock);
1843 return mstb;
1844}
1845
1846static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1847 struct drm_dp_mst_branch *mstb)
1848{
1849 struct drm_dp_mst_port *port;
1850 struct drm_dp_mst_branch *mstb_child;
1851 if (!mstb->link_address_sent)
1852 drm_dp_send_link_address(mgr, mstb);
1853
1854 list_for_each_entry(port, &mstb->ports, next) {
1855 if (port->input)
1856 continue;
1857
1858 if (!port->ddps)
1859 continue;
1860
1861 if (!port->available_pbn)
1862 drm_dp_send_enum_path_resources(mgr, mstb, port);
1863
1864 if (port->mstb) {
1865 mstb_child = drm_dp_mst_topology_get_mstb_validated(
1866 mgr, port->mstb);
1867 if (mstb_child) {
1868 drm_dp_check_and_send_link_address(mgr, mstb_child);
1869 drm_dp_mst_topology_put_mstb(mstb_child);
1870 }
1871 }
1872 }
1873}
1874
1875static void drm_dp_mst_link_probe_work(struct work_struct *work)
1876{
1877 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1878 struct drm_dp_mst_branch *mstb;
1879 int ret;
1880
1881 mutex_lock(&mgr->lock);
1882 mstb = mgr->mst_primary;
1883 if (mstb) {
1884 ret = drm_dp_mst_topology_try_get_mstb(mstb);
1885 if (!ret)
1886 mstb = NULL;
1887 }
1888 mutex_unlock(&mgr->lock);
1889 if (mstb) {
1890 drm_dp_check_and_send_link_address(mgr, mstb);
1891 drm_dp_mst_topology_put_mstb(mstb);
1892 }
1893}
1894
1895static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1896 u8 *guid)
1897{
1898 u64 salt;
1899
1900 if (memchr_inv(guid, 0, 16))
1901 return true;
1902
1903 salt = get_jiffies_64();
1904
1905 memcpy(&guid[0], &salt, sizeof(u64));
1906 memcpy(&guid[8], &salt, sizeof(u64));
1907
1908 return false;
1909}
1910
1911static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1912{
1913 struct drm_dp_sideband_msg_req_body req;
1914
1915 req.req_type = DP_REMOTE_DPCD_READ;
1916 req.u.dpcd_read.port_number = port_num;
1917 req.u.dpcd_read.dpcd_address = offset;
1918 req.u.dpcd_read.num_bytes = num_bytes;
1919 drm_dp_encode_sideband_req(&req, msg);
1920
1921 return 0;
1922}
1923
1924static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1925 bool up, u8 *msg, int len)
1926{
1927 int ret;
1928 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1929 int tosend, total, offset;
1930 int retries = 0;
1931
1932retry:
1933 total = len;
1934 offset = 0;
1935 do {
1936 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1937
1938 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1939 &msg[offset],
1940 tosend);
1941 if (ret != tosend) {
1942 if (ret == -EIO && retries < 5) {
1943 retries++;
1944 goto retry;
1945 }
1946 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1947
1948 return -EIO;
1949 }
1950 offset += tosend;
1951 total -= tosend;
1952 } while (total > 0);
1953 return 0;
1954}
1955
1956static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1957 struct drm_dp_sideband_msg_tx *txmsg)
1958{
1959 struct drm_dp_mst_branch *mstb = txmsg->dst;
1960 u8 req_type;
1961
1962 /* both msg slots are full */
1963 if (txmsg->seqno == -1) {
1964 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1965 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1966 return -EAGAIN;
1967 }
1968 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1969 txmsg->seqno = mstb->last_seqno;
1970 mstb->last_seqno ^= 1;
1971 } else if (mstb->tx_slots[0] == NULL)
1972 txmsg->seqno = 0;
1973 else
1974 txmsg->seqno = 1;
1975 mstb->tx_slots[txmsg->seqno] = txmsg;
1976 }
1977
1978 req_type = txmsg->msg[0] & 0x7f;
1979 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1980 req_type == DP_RESOURCE_STATUS_NOTIFY)
1981 hdr->broadcast = 1;
1982 else
1983 hdr->broadcast = 0;
1984 hdr->path_msg = txmsg->path_msg;
1985 hdr->lct = mstb->lct;
1986 hdr->lcr = mstb->lct - 1;
1987 if (mstb->lct > 1)
1988 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1989 hdr->seqno = txmsg->seqno;
1990 return 0;
1991}
1992/*
1993 * process a single block of the next message in the sideband queue
1994 */
1995static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1996 struct drm_dp_sideband_msg_tx *txmsg,
1997 bool up)
1998{
1999 u8 chunk[48];
2000 struct drm_dp_sideband_msg_hdr hdr;
2001 int len, space, idx, tosend;
2002 int ret;
2003
2004 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
2005
2006 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
2007 txmsg->seqno = -1;
2008 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
2009 }
2010
2011 /* make hdr from dst mst - for replies use seqno
2012 otherwise assign one */
2013 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
2014 if (ret < 0)
2015 return ret;
2016
2017 /* amount left to send in this message */
2018 len = txmsg->cur_len - txmsg->cur_offset;
2019
2020 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
2021 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
2022
2023 tosend = min(len, space);
2024 if (len == txmsg->cur_len)
2025 hdr.somt = 1;
2026 if (space >= len)
2027 hdr.eomt = 1;
2028
2029
2030 hdr.msg_len = tosend + 1;
2031 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
2032 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
2033 /* add crc at end */
2034 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
2035 idx += tosend + 1;
2036
2037 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
2038 if (ret) {
2039 DRM_DEBUG_KMS("sideband msg failed to send\n");
2040 return ret;
2041 }
2042
2043 txmsg->cur_offset += tosend;
2044 if (txmsg->cur_offset == txmsg->cur_len) {
2045 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
2046 return 1;
2047 }
2048 return 0;
2049}
2050
2051static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
2052{
2053 struct drm_dp_sideband_msg_tx *txmsg;
2054 int ret;
2055
2056 WARN_ON(!mutex_is_locked(&mgr->qlock));
2057
2058 /* construct a chunk from the first msg in the tx_msg queue */
2059 if (list_empty(&mgr->tx_msg_downq))
2060 return;
2061
2062 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
2063 ret = process_single_tx_qlock(mgr, txmsg, false);
2064 if (ret == 1) {
2065 /* txmsg is sent it should be in the slots now */
2066 list_del(&txmsg->next);
2067 } else if (ret) {
2068 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
2069 list_del(&txmsg->next);
2070 if (txmsg->seqno != -1)
2071 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
2072 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
2073 wake_up_all(&mgr->tx_waitq);
2074 }
2075}
2076
2077/* called holding qlock */
2078static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2079 struct drm_dp_sideband_msg_tx *txmsg)
2080{
2081 int ret;
2082
2083 /* construct a chunk from the first msg in the tx_msg queue */
2084 ret = process_single_tx_qlock(mgr, txmsg, true);
2085
2086 if (ret != 1)
2087 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
2088
2089 if (txmsg->seqno != -1) {
2090 WARN_ON((unsigned int)txmsg->seqno >
2091 ARRAY_SIZE(txmsg->dst->tx_slots));
2092 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
2093 }
2094}
2095
2096static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
2097 struct drm_dp_sideband_msg_tx *txmsg)
2098{
2099 mutex_lock(&mgr->qlock);
2100 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
2101 if (list_is_singular(&mgr->tx_msg_downq))
2102 process_single_down_tx_qlock(mgr);
2103 mutex_unlock(&mgr->qlock);
2104}
2105
2106static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2107 struct drm_dp_mst_branch *mstb)
2108{
2109 int len;
2110 struct drm_dp_sideband_msg_tx *txmsg;
2111 int ret;
2112
2113 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2114 if (!txmsg)
2115 return;
2116
2117 txmsg->dst = mstb;
2118 len = build_link_address(txmsg);
2119
2120 mstb->link_address_sent = true;
2121 drm_dp_queue_down_tx(mgr, txmsg);
2122
2123 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2124 if (ret > 0) {
2125 int i;
2126
2127 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2128 DRM_DEBUG_KMS("link address nak received\n");
2129 } else {
2130 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
2131 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
2132 DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", i,
2133 txmsg->reply.u.link_addr.ports[i].input_port,
2134 txmsg->reply.u.link_addr.ports[i].peer_device_type,
2135 txmsg->reply.u.link_addr.ports[i].port_number,
2136 txmsg->reply.u.link_addr.ports[i].dpcd_revision,
2137 txmsg->reply.u.link_addr.ports[i].mcs,
2138 txmsg->reply.u.link_addr.ports[i].ddps,
2139 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
2140 txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
2141 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
2142 }
2143
2144 drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
2145
2146 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
2147 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
2148 }
2149 drm_kms_helper_hotplug_event(mgr->dev);
2150 }
2151 } else {
2152 mstb->link_address_sent = false;
2153 DRM_DEBUG_KMS("link address failed %d\n", ret);
2154 }
2155
2156 kfree(txmsg);
2157}
2158
2159static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
2160 struct drm_dp_mst_branch *mstb,
2161 struct drm_dp_mst_port *port)
2162{
2163 int len;
2164 struct drm_dp_sideband_msg_tx *txmsg;
2165 int ret;
2166
2167 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2168 if (!txmsg)
2169 return -ENOMEM;
2170
2171 txmsg->dst = mstb;
2172 len = build_enum_path_resources(txmsg, port->port_num);
2173
2174 drm_dp_queue_down_tx(mgr, txmsg);
2175
2176 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2177 if (ret > 0) {
2178 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2179 DRM_DEBUG_KMS("enum path resources nak received\n");
2180 } else {
2181 if (port->port_num != txmsg->reply.u.path_resources.port_number)
2182 DRM_ERROR("got incorrect port in response\n");
2183 DRM_DEBUG_KMS("enum path resources %d: %d %d\n", txmsg->reply.u.path_resources.port_number, txmsg->reply.u.path_resources.full_payload_bw_number,
2184 txmsg->reply.u.path_resources.avail_payload_bw_number);
2185 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
2186 }
2187 }
2188
2189 kfree(txmsg);
2190 return 0;
2191}
2192
2193static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
2194{
2195 if (!mstb->port_parent)
2196 return NULL;
2197
2198 if (mstb->port_parent->mstb != mstb)
2199 return mstb->port_parent;
2200
2201 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
2202}
2203
2204/*
2205 * Searches upwards in the topology starting from mstb to try to find the
2206 * closest available parent of mstb that's still connected to the rest of the
2207 * topology. This can be used in order to perform operations like releasing
2208 * payloads, where the branch device which owned the payload may no longer be
2209 * around and thus would require that the payload on the last living relative
2210 * be freed instead.
2211 */
2212static struct drm_dp_mst_branch *
2213drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
2214 struct drm_dp_mst_branch *mstb,
2215 int *port_num)
2216{
2217 struct drm_dp_mst_branch *rmstb = NULL;
2218 struct drm_dp_mst_port *found_port;
2219
2220 mutex_lock(&mgr->lock);
2221 if (!mgr->mst_primary)
2222 goto out;
2223
2224 do {
2225 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
2226 if (!found_port)
2227 break;
2228
2229 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
2230 rmstb = found_port->parent;
2231 *port_num = found_port->port_num;
2232 } else {
2233 /* Search again, starting from this parent */
2234 mstb = found_port->parent;
2235 }
2236 } while (!rmstb);
2237out:
2238 mutex_unlock(&mgr->lock);
2239 return rmstb;
2240}
2241
2242static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
2243 struct drm_dp_mst_port *port,
2244 int id,
2245 int pbn)
2246{
2247 struct drm_dp_sideband_msg_tx *txmsg;
2248 struct drm_dp_mst_branch *mstb;
2249 int len, ret, port_num;
2250 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
2251 int i;
2252
2253 port_num = port->port_num;
2254 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
2255 if (!mstb) {
2256 mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
2257 port->parent,
2258 &port_num);
2259
2260 if (!mstb)
2261 return -EINVAL;
2262 }
2263
2264 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2265 if (!txmsg) {
2266 ret = -ENOMEM;
2267 goto fail_put;
2268 }
2269
2270 for (i = 0; i < port->num_sdp_streams; i++)
2271 sinks[i] = i;
2272
2273 txmsg->dst = mstb;
2274 len = build_allocate_payload(txmsg, port_num,
2275 id,
2276 pbn, port->num_sdp_streams, sinks);
2277
2278 drm_dp_queue_down_tx(mgr, txmsg);
2279
2280 /*
2281 * FIXME: there is a small chance that between getting the last
2282 * connected mstb and sending the payload message, the last connected
2283 * mstb could also be removed from the topology. In the future, this
2284 * needs to be fixed by restarting the
2285 * drm_dp_get_last_connected_port_and_mstb() search in the event of a
2286 * timeout if the topology is still connected to the system.
2287 */
2288 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2289 if (ret > 0) {
2290 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
2291 ret = -EINVAL;
2292 else
2293 ret = 0;
2294 }
2295 kfree(txmsg);
2296fail_put:
2297 drm_dp_mst_topology_put_mstb(mstb);
2298 return ret;
2299}
2300
2301int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
2302 struct drm_dp_mst_port *port, bool power_up)
2303{
2304 struct drm_dp_sideband_msg_tx *txmsg;
2305 int len, ret;
2306
2307 port = drm_dp_mst_topology_get_port_validated(mgr, port);
2308 if (!port)
2309 return -EINVAL;
2310
2311 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2312 if (!txmsg) {
2313 drm_dp_mst_topology_put_port(port);
2314 return -ENOMEM;
2315 }
2316
2317 txmsg->dst = port->parent;
2318 len = build_power_updown_phy(txmsg, port->port_num, power_up);
2319 drm_dp_queue_down_tx(mgr, txmsg);
2320
2321 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
2322 if (ret > 0) {
2323 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
2324 ret = -EINVAL;
2325 else
2326 ret = 0;
2327 }
2328 kfree(txmsg);
2329 drm_dp_mst_topology_put_port(port);
2330
2331 return ret;
2332}
2333EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
2334
2335static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
2336 int id,
2337 struct drm_dp_payload *payload)
2338{
2339 int ret;
2340
2341 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
2342 if (ret < 0) {
2343 payload->payload_state = 0;
2344 return ret;
2345 }
2346 payload->payload_state = DP_PAYLOAD_LOCAL;
2347 return 0;
2348}
2349
2350static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
2351 struct drm_dp_mst_port *port,
2352 int id,
2353 struct drm_dp_payload *payload)
2354{
2355 int ret;
2356 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
2357 if (ret < 0)
2358 return ret;
2359 payload->payload_state = DP_PAYLOAD_REMOTE;
2360 return ret;
2361}
2362
2363static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
2364 struct drm_dp_mst_port *port,
2365 int id,
2366 struct drm_dp_payload *payload)
2367{
2368 DRM_DEBUG_KMS("\n");
2369 /* it's okay for these to fail */
2370 if (port) {
2371 drm_dp_payload_send_msg(mgr, port, id, 0);
2372 }
2373
2374 drm_dp_dpcd_write_payload(mgr, id, payload);
2375 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
2376 return 0;
2377}
2378
2379static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
2380 int id,
2381 struct drm_dp_payload *payload)
2382{
2383 payload->payload_state = 0;
2384 return 0;
2385}
2386
2387/**
2388 * drm_dp_update_payload_part1() - Execute payload update part 1
2389 * @mgr: manager to use.
2390 *
2391 * This iterates over all proposed virtual channels, and tries to
2392 * allocate space in the link for them. For 0->slots transitions,
2393 * this step just writes the VCPI to the MST device. For slots->0
2394 * transitions, this writes the updated VCPIs and removes the
2395 * remote VC payloads.
2396 *
2397 * after calling this the driver should generate ACT and payload
2398 * packets.
2399 */
2400int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
2401{
2402 struct drm_dp_payload req_payload;
2403 struct drm_dp_mst_port *port;
2404 int i, j;
2405 int cur_slots = 1;
2406
2407 mutex_lock(&mgr->payload_lock);
2408 for (i = 0; i < mgr->max_payloads; i++) {
2409 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
2410 struct drm_dp_payload *payload = &mgr->payloads[i];
2411 bool put_port = false;
2412
2413 /* solve the current payloads - compare to the hw ones
2414 - update the hw view */
2415 req_payload.start_slot = cur_slots;
2416 if (vcpi) {
2417 port = container_of(vcpi, struct drm_dp_mst_port,
2418 vcpi);
2419
2420 /* Validated ports don't matter if we're releasing
2421 * VCPI
2422 */
2423 if (vcpi->num_slots) {
2424 port = drm_dp_mst_topology_get_port_validated(
2425 mgr, port);
2426 if (!port) {
2427 mutex_unlock(&mgr->payload_lock);
2428 return -EINVAL;
2429 }
2430 put_port = true;
2431 }
2432
2433 req_payload.num_slots = vcpi->num_slots;
2434 req_payload.vcpi = vcpi->vcpi;
2435 } else {
2436 port = NULL;
2437 req_payload.num_slots = 0;
2438 }
2439
2440 payload->start_slot = req_payload.start_slot;
2441 /* work out what is required to happen with this payload */
2442 if (payload->num_slots != req_payload.num_slots) {
2443
2444 /* need to push an update for this payload */
2445 if (req_payload.num_slots) {
2446 drm_dp_create_payload_step1(mgr, vcpi->vcpi,
2447 &req_payload);
2448 payload->num_slots = req_payload.num_slots;
2449 payload->vcpi = req_payload.vcpi;
2450
2451 } else if (payload->num_slots) {
2452 payload->num_slots = 0;
2453 drm_dp_destroy_payload_step1(mgr, port,
2454 payload->vcpi,
2455 payload);
2456 req_payload.payload_state =
2457 payload->payload_state;
2458 payload->start_slot = 0;
2459 }
2460 payload->payload_state = req_payload.payload_state;
2461 }
2462 cur_slots += req_payload.num_slots;
2463
2464 if (put_port)
2465 drm_dp_mst_topology_put_port(port);
2466 }
2467
2468 for (i = 0; i < mgr->max_payloads; i++) {
2469 if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL)
2470 continue;
2471
2472 DRM_DEBUG_KMS("removing payload %d\n", i);
2473 for (j = i; j < mgr->max_payloads - 1; j++) {
2474 mgr->payloads[j] = mgr->payloads[j + 1];
2475 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
2476
2477 if (mgr->proposed_vcpis[j] &&
2478 mgr->proposed_vcpis[j]->num_slots) {
2479 set_bit(j + 1, &mgr->payload_mask);
2480 } else {
2481 clear_bit(j + 1, &mgr->payload_mask);
2482 }
2483 }
2484
2485 memset(&mgr->payloads[mgr->max_payloads - 1], 0,
2486 sizeof(struct drm_dp_payload));
2487 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
2488 clear_bit(mgr->max_payloads, &mgr->payload_mask);
2489 }
2490 mutex_unlock(&mgr->payload_lock);
2491
2492 return 0;
2493}
2494EXPORT_SYMBOL(drm_dp_update_payload_part1);
2495
2496/**
2497 * drm_dp_update_payload_part2() - Execute payload update part 2
2498 * @mgr: manager to use.
2499 *
2500 * This iterates over all proposed virtual channels, and tries to
2501 * allocate space in the link for them. For 0->slots transitions,
2502 * this step writes the remote VC payload commands. For slots->0
2503 * this just resets some internal state.
2504 */
2505int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
2506{
2507 struct drm_dp_mst_port *port;
2508 int i;
2509 int ret = 0;
2510 mutex_lock(&mgr->payload_lock);
2511 for (i = 0; i < mgr->max_payloads; i++) {
2512
2513 if (!mgr->proposed_vcpis[i])
2514 continue;
2515
2516 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2517
2518 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
2519 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
2520 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
2521 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
2522 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
2523 }
2524 if (ret) {
2525 mutex_unlock(&mgr->payload_lock);
2526 return ret;
2527 }
2528 }
2529 mutex_unlock(&mgr->payload_lock);
2530 return 0;
2531}
2532EXPORT_SYMBOL(drm_dp_update_payload_part2);
2533
2534static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
2535 struct drm_dp_mst_port *port,
2536 int offset, int size, u8 *bytes)
2537{
2538 int len;
2539 int ret = 0;
2540 struct drm_dp_sideband_msg_tx *txmsg;
2541 struct drm_dp_mst_branch *mstb;
2542
2543 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
2544 if (!mstb)
2545 return -EINVAL;
2546
2547 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2548 if (!txmsg) {
2549 ret = -ENOMEM;
2550 goto fail_put;
2551 }
2552
2553 len = build_dpcd_read(txmsg, port->port_num, offset, size);
2554 txmsg->dst = port->parent;
2555
2556 drm_dp_queue_down_tx(mgr, txmsg);
2557
2558 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2559 if (ret < 0)
2560 goto fail_free;
2561
2562 /* DPCD read should never be NACKed */
2563 if (txmsg->reply.reply_type == 1) {
2564 DRM_ERROR("mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n",
2565 mstb, port->port_num, offset, size);
2566 ret = -EIO;
2567 goto fail_free;
2568 }
2569
2570 if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) {
2571 ret = -EPROTO;
2572 goto fail_free;
2573 }
2574
2575 ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes,
2576 size);
2577 memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret);
2578
2579fail_free:
2580 kfree(txmsg);
2581fail_put:
2582 drm_dp_mst_topology_put_mstb(mstb);
2583
2584 return ret;
2585}
2586
2587static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
2588 struct drm_dp_mst_port *port,
2589 int offset, int size, u8 *bytes)
2590{
2591 int len;
2592 int ret;
2593 struct drm_dp_sideband_msg_tx *txmsg;
2594 struct drm_dp_mst_branch *mstb;
2595
2596 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
2597 if (!mstb)
2598 return -EINVAL;
2599
2600 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2601 if (!txmsg) {
2602 ret = -ENOMEM;
2603 goto fail_put;
2604 }
2605
2606 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
2607 txmsg->dst = mstb;
2608
2609 drm_dp_queue_down_tx(mgr, txmsg);
2610
2611 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2612 if (ret > 0) {
2613 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
2614 ret = -EIO;
2615 else
2616 ret = 0;
2617 }
2618 kfree(txmsg);
2619fail_put:
2620 drm_dp_mst_topology_put_mstb(mstb);
2621 return ret;
2622}
2623
2624static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
2625{
2626 struct drm_dp_sideband_msg_reply_body reply;
2627
2628 reply.reply_type = DP_SIDEBAND_REPLY_ACK;
2629 reply.req_type = req_type;
2630 drm_dp_encode_sideband_reply(&reply, msg);
2631 return 0;
2632}
2633
2634static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
2635 struct drm_dp_mst_branch *mstb,
2636 int req_type, int seqno, bool broadcast)
2637{
2638 struct drm_dp_sideband_msg_tx *txmsg;
2639
2640 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2641 if (!txmsg)
2642 return -ENOMEM;
2643
2644 txmsg->dst = mstb;
2645 txmsg->seqno = seqno;
2646 drm_dp_encode_up_ack_reply(txmsg, req_type);
2647
2648 mutex_lock(&mgr->qlock);
2649
2650 process_single_up_tx_qlock(mgr, txmsg);
2651
2652 mutex_unlock(&mgr->qlock);
2653
2654 kfree(txmsg);
2655 return 0;
2656}
2657
2658static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
2659 int dp_link_count,
2660 int *out)
2661{
2662 switch (dp_link_bw) {
2663 default:
2664 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
2665 dp_link_bw, dp_link_count);
2666 return false;
2667
2668 case DP_LINK_BW_1_62:
2669 *out = 3 * dp_link_count;
2670 break;
2671 case DP_LINK_BW_2_7:
2672 *out = 5 * dp_link_count;
2673 break;
2674 case DP_LINK_BW_5_4:
2675 *out = 10 * dp_link_count;
2676 break;
2677 case DP_LINK_BW_8_1:
2678 *out = 15 * dp_link_count;
2679 break;
2680 }
2681 return true;
2682}
2683
2684/**
2685 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
2686 * @mgr: manager to set state for
2687 * @mst_state: true to enable MST on this connector - false to disable.
2688 *
2689 * This is called by the driver when it detects an MST capable device plugged
2690 * into a DP MST capable port, or when a DP MST capable device is unplugged.
2691 */
2692int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
2693{
2694 int ret = 0;
2695 struct drm_dp_mst_branch *mstb = NULL;
2696
2697 mutex_lock(&mgr->lock);
2698 if (mst_state == mgr->mst_state)
2699 goto out_unlock;
2700
2701 mgr->mst_state = mst_state;
2702 /* set the device into MST mode */
2703 if (mst_state) {
2704 WARN_ON(mgr->mst_primary);
2705
2706 /* get dpcd info */
2707 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2708 if (ret != DP_RECEIVER_CAP_SIZE) {
2709 DRM_DEBUG_KMS("failed to read DPCD\n");
2710 goto out_unlock;
2711 }
2712
2713 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2714 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2715 &mgr->pbn_div)) {
2716 ret = -EINVAL;
2717 goto out_unlock;
2718 }
2719
2720 /* add initial branch device at LCT 1 */
2721 mstb = drm_dp_add_mst_branch_device(1, NULL);
2722 if (mstb == NULL) {
2723 ret = -ENOMEM;
2724 goto out_unlock;
2725 }
2726 mstb->mgr = mgr;
2727
2728 /* give this the main reference */
2729 mgr->mst_primary = mstb;
2730 drm_dp_mst_topology_get_mstb(mgr->mst_primary);
2731
2732 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2733 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2734 if (ret < 0) {
2735 goto out_unlock;
2736 }
2737
2738 {
2739 struct drm_dp_payload reset_pay;
2740 reset_pay.start_slot = 0;
2741 reset_pay.num_slots = 0x3f;
2742 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2743 }
2744
2745 queue_work(system_long_wq, &mgr->work);
2746
2747 ret = 0;
2748 } else {
2749 /* disable MST on the device */
2750 mstb = mgr->mst_primary;
2751 mgr->mst_primary = NULL;
2752 /* this can fail if the device is gone */
2753 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2754 ret = 0;
2755 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2756 mgr->payload_mask = 0;
2757 set_bit(0, &mgr->payload_mask);
2758 mgr->vcpi_mask = 0;
2759 }
2760
2761out_unlock:
2762 mutex_unlock(&mgr->lock);
2763 if (mstb)
2764 drm_dp_mst_topology_put_mstb(mstb);
2765 return ret;
2766
2767}
2768EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2769
2770/**
2771 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2772 * @mgr: manager to suspend
2773 *
2774 * This function tells the MST device that we can't handle UP messages
2775 * anymore. This should stop it from sending any since we are suspended.
2776 */
2777void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2778{
2779 mutex_lock(&mgr->lock);
2780 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2781 DP_MST_EN | DP_UPSTREAM_IS_SRC);
2782 mutex_unlock(&mgr->lock);
2783 flush_work(&mgr->work);
2784 flush_work(&mgr->destroy_connector_work);
2785}
2786EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2787
2788/**
2789 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2790 * @mgr: manager to resume
2791 *
2792 * This will fetch DPCD and see if the device is still there,
2793 * if it is, it will rewrite the MSTM control bits, and return.
2794 *
2795 * if the device fails this returns -1, and the driver should do
2796 * a full MST reprobe, in case we were undocked.
2797 */
2798int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2799{
2800 int ret = 0;
2801
2802 mutex_lock(&mgr->lock);
2803
2804 if (mgr->mst_primary) {
2805 int sret;
2806 u8 guid[16];
2807
2808 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2809 if (sret != DP_RECEIVER_CAP_SIZE) {
2810 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2811 ret = -1;
2812 goto out_unlock;
2813 }
2814
2815 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2816 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2817 if (ret < 0) {
2818 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2819 ret = -1;
2820 goto out_unlock;
2821 }
2822
2823 /* Some hubs forget their guids after they resume */
2824 sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
2825 if (sret != 16) {
2826 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2827 ret = -1;
2828 goto out_unlock;
2829 }
2830 drm_dp_check_mstb_guid(mgr->mst_primary, guid);
2831
2832 ret = 0;
2833 } else
2834 ret = -1;
2835
2836out_unlock:
2837 mutex_unlock(&mgr->lock);
2838 return ret;
2839}
2840EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2841
2842static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2843{
2844 int len;
2845 u8 replyblock[32];
2846 int replylen, origlen, curreply;
2847 int ret;
2848 struct drm_dp_sideband_msg_rx *msg;
2849 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2850 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2851
2852 len = min(mgr->max_dpcd_transaction_bytes, 16);
2853 ret = drm_dp_dpcd_read(mgr->aux, basereg,
2854 replyblock, len);
2855 if (ret != len) {
2856 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2857 return false;
2858 }
2859 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2860 if (!ret) {
2861 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2862 return false;
2863 }
2864 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2865
2866 origlen = replylen;
2867 replylen -= len;
2868 curreply = len;
2869 while (replylen > 0) {
2870 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2871 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2872 replyblock, len);
2873 if (ret != len) {
2874 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
2875 len, ret);
2876 return false;
2877 }
2878
2879 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2880 if (!ret) {
2881 DRM_DEBUG_KMS("failed to build sideband msg\n");
2882 return false;
2883 }
2884
2885 curreply += len;
2886 replylen -= len;
2887 }
2888 return true;
2889}
2890
2891static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2892{
2893 int ret = 0;
2894
2895 if (!drm_dp_get_one_sb_msg(mgr, false)) {
2896 memset(&mgr->down_rep_recv, 0,
2897 sizeof(struct drm_dp_sideband_msg_rx));
2898 return 0;
2899 }
2900
2901 if (mgr->down_rep_recv.have_eomt) {
2902 struct drm_dp_sideband_msg_tx *txmsg;
2903 struct drm_dp_mst_branch *mstb;
2904 int slot = -1;
2905 mstb = drm_dp_get_mst_branch_device(mgr,
2906 mgr->down_rep_recv.initial_hdr.lct,
2907 mgr->down_rep_recv.initial_hdr.rad);
2908
2909 if (!mstb) {
2910 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2911 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2912 return 0;
2913 }
2914
2915 /* find the message */
2916 slot = mgr->down_rep_recv.initial_hdr.seqno;
2917 mutex_lock(&mgr->qlock);
2918 txmsg = mstb->tx_slots[slot];
2919 /* remove from slots */
2920 mutex_unlock(&mgr->qlock);
2921
2922 if (!txmsg) {
2923 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2924 mstb,
2925 mgr->down_rep_recv.initial_hdr.seqno,
2926 mgr->down_rep_recv.initial_hdr.lct,
2927 mgr->down_rep_recv.initial_hdr.rad[0],
2928 mgr->down_rep_recv.msg[0]);
2929 drm_dp_mst_topology_put_mstb(mstb);
2930 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2931 return 0;
2932 }
2933
2934 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2935
2936 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
2937 DRM_DEBUG_KMS("Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
2938 txmsg->reply.req_type,
2939 drm_dp_mst_req_type_str(txmsg->reply.req_type),
2940 txmsg->reply.u.nak.reason,
2941 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason),
2942 txmsg->reply.u.nak.nak_data);
2943
2944 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2945 drm_dp_mst_topology_put_mstb(mstb);
2946
2947 mutex_lock(&mgr->qlock);
2948 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2949 mstb->tx_slots[slot] = NULL;
2950 mutex_unlock(&mgr->qlock);
2951
2952 wake_up_all(&mgr->tx_waitq);
2953 }
2954 return ret;
2955}
2956
2957static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2958{
2959 int ret = 0;
2960
2961 if (!drm_dp_get_one_sb_msg(mgr, true)) {
2962 memset(&mgr->up_req_recv, 0,
2963 sizeof(struct drm_dp_sideband_msg_rx));
2964 return 0;
2965 }
2966
2967 if (mgr->up_req_recv.have_eomt) {
2968 struct drm_dp_sideband_msg_req_body msg;
2969 struct drm_dp_mst_branch *mstb = NULL;
2970 bool seqno;
2971
2972 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2973 mstb = drm_dp_get_mst_branch_device(mgr,
2974 mgr->up_req_recv.initial_hdr.lct,
2975 mgr->up_req_recv.initial_hdr.rad);
2976 if (!mstb) {
2977 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2978 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2979 return 0;
2980 }
2981 }
2982
2983 seqno = mgr->up_req_recv.initial_hdr.seqno;
2984 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2985
2986 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2987 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2988
2989 if (!mstb)
2990 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2991
2992 if (!mstb) {
2993 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2994 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2995 return 0;
2996 }
2997
2998 drm_dp_update_port(mstb, &msg.u.conn_stat);
2999
3000 DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", msg.u.conn_stat.port_number, msg.u.conn_stat.legacy_device_plug_status, msg.u.conn_stat.displayport_device_plug_status, msg.u.conn_stat.message_capability_status, msg.u.conn_stat.input_port, msg.u.conn_stat.peer_device_type);
3001 drm_kms_helper_hotplug_event(mgr->dev);
3002
3003 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
3004 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
3005 if (!mstb)
3006 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
3007
3008 if (!mstb) {
3009 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
3010 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
3011 return 0;
3012 }
3013
3014 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
3015 }
3016
3017 if (mstb)
3018 drm_dp_mst_topology_put_mstb(mstb);
3019
3020 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
3021 }
3022 return ret;
3023}
3024
3025/**
3026 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
3027 * @mgr: manager to notify irq for.
3028 * @esi: 4 bytes from SINK_COUNT_ESI
3029 * @handled: whether the hpd interrupt was consumed or not
3030 *
3031 * This should be called from the driver when it detects a short IRQ,
3032 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
3033 * topology manager will process the sideband messages received as a result
3034 * of this.
3035 */
3036int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
3037{
3038 int ret = 0;
3039 int sc;
3040 *handled = false;
3041 sc = esi[0] & 0x3f;
3042
3043 if (sc != mgr->sink_count) {
3044 mgr->sink_count = sc;
3045 *handled = true;
3046 }
3047
3048 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
3049 ret = drm_dp_mst_handle_down_rep(mgr);
3050 *handled = true;
3051 }
3052
3053 if (esi[1] & DP_UP_REQ_MSG_RDY) {
3054 ret |= drm_dp_mst_handle_up_req(mgr);
3055 *handled = true;
3056 }
3057
3058 drm_dp_mst_kick_tx(mgr);
3059 return ret;
3060}
3061EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
3062
3063/**
3064 * drm_dp_mst_detect_port() - get connection status for an MST port
3065 * @connector: DRM connector for this port
3066 * @mgr: manager for this port
3067 * @port: unverified pointer to a port
3068 *
3069 * This returns the current connection state for a port. It validates the
3070 * port pointer still exists so the caller doesn't require a reference
3071 */
3072enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
3073 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
3074{
3075 enum drm_connector_status status = connector_status_disconnected;
3076
3077 /* we need to search for the port in the mgr in case it's gone */
3078 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3079 if (!port)
3080 return connector_status_disconnected;
3081
3082 if (!port->ddps)
3083 goto out;
3084
3085 switch (port->pdt) {
3086 case DP_PEER_DEVICE_NONE:
3087 case DP_PEER_DEVICE_MST_BRANCHING:
3088 break;
3089
3090 case DP_PEER_DEVICE_SST_SINK:
3091 status = connector_status_connected;
3092 /* for logical ports - cache the EDID */
3093 if (port->port_num >= 8 && !port->cached_edid) {
3094 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
3095 }
3096 break;
3097 case DP_PEER_DEVICE_DP_LEGACY_CONV:
3098 if (port->ldps)
3099 status = connector_status_connected;
3100 break;
3101 }
3102out:
3103 drm_dp_mst_topology_put_port(port);
3104 return status;
3105}
3106EXPORT_SYMBOL(drm_dp_mst_detect_port);
3107
3108/**
3109 * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
3110 * @mgr: manager for this port
3111 * @port: unverified pointer to a port.
3112 *
3113 * This returns whether the port supports audio or not.
3114 */
3115bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
3116 struct drm_dp_mst_port *port)
3117{
3118 bool ret = false;
3119
3120 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3121 if (!port)
3122 return ret;
3123 ret = port->has_audio;
3124 drm_dp_mst_topology_put_port(port);
3125 return ret;
3126}
3127EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
3128
3129/**
3130 * drm_dp_mst_get_edid() - get EDID for an MST port
3131 * @connector: toplevel connector to get EDID for
3132 * @mgr: manager for this port
3133 * @port: unverified pointer to a port.
3134 *
3135 * This returns an EDID for the port connected to a connector,
3136 * It validates the pointer still exists so the caller doesn't require a
3137 * reference.
3138 */
3139struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
3140{
3141 struct edid *edid = NULL;
3142
3143 /* we need to search for the port in the mgr in case it's gone */
3144 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3145 if (!port)
3146 return NULL;
3147
3148 if (port->cached_edid)
3149 edid = drm_edid_duplicate(port->cached_edid);
3150 else {
3151 edid = drm_get_edid(connector, &port->aux.ddc);
3152 }
3153 port->has_audio = drm_detect_monitor_audio(edid);
3154 drm_dp_mst_topology_put_port(port);
3155 return edid;
3156}
3157EXPORT_SYMBOL(drm_dp_mst_get_edid);
3158
3159/**
3160 * drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
3161 * @mgr: manager to use
3162 * @pbn: payload bandwidth to convert into slots.
3163 *
3164 * Calculate the number of VCPI slots that will be required for the given PBN
3165 * value. This function is deprecated, and should not be used in atomic
3166 * drivers.
3167 *
3168 * RETURNS:
3169 * The total slots required for this port, or error.
3170 */
3171int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
3172 int pbn)
3173{
3174 int num_slots;
3175
3176 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
3177
3178 /* max. time slots - one slot for MTP header */
3179 if (num_slots > 63)
3180 return -ENOSPC;
3181 return num_slots;
3182}
3183EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
3184
3185static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
3186 struct drm_dp_vcpi *vcpi, int pbn, int slots)
3187{
3188 int ret;
3189
3190 /* max. time slots - one slot for MTP header */
3191 if (slots > 63)
3192 return -ENOSPC;
3193
3194 vcpi->pbn = pbn;
3195 vcpi->aligned_pbn = slots * mgr->pbn_div;
3196 vcpi->num_slots = slots;
3197
3198 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
3199 if (ret < 0)
3200 return ret;
3201 return 0;
3202}
3203
3204/**
3205 * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
3206 * @state: global atomic state
3207 * @mgr: MST topology manager for the port
3208 * @port: port to find vcpi slots for
3209 * @pbn: bandwidth required for the mode in PBN
3210 *
3211 * Allocates VCPI slots to @port, replacing any previous VCPI allocations it
3212 * may have had. Any atomic drivers which support MST must call this function
3213 * in their &drm_encoder_helper_funcs.atomic_check() callback to change the
3214 * current VCPI allocation for the new state, but only when
3215 * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set
3216 * to ensure compatibility with userspace applications that still use the
3217 * legacy modesetting UAPI.
3218 *
3219 * Allocations set by this function are not checked against the bandwidth
3220 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
3221 *
3222 * Additionally, it is OK to call this function multiple times on the same
3223 * @port as needed. It is not OK however, to call this function and
3224 * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
3225 *
3226 * See also:
3227 * drm_dp_atomic_release_vcpi_slots()
3228 * drm_dp_mst_atomic_check()
3229 *
3230 * Returns:
3231 * Total slots in the atomic state assigned for this port, or a negative error
3232 * code if the port no longer exists
3233 */
3234int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
3235 struct drm_dp_mst_topology_mgr *mgr,
3236 struct drm_dp_mst_port *port, int pbn)
3237{
3238 struct drm_dp_mst_topology_state *topology_state;
3239 struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
3240 int prev_slots, req_slots, ret;
3241
3242 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
3243 if (IS_ERR(topology_state))
3244 return PTR_ERR(topology_state);
3245
3246 /* Find the current allocation for this port, if any */
3247 list_for_each_entry(pos, &topology_state->vcpis, next) {
3248 if (pos->port == port) {
3249 vcpi = pos;
3250 prev_slots = vcpi->vcpi;
3251
3252 /*
3253 * This should never happen, unless the driver tries
3254 * releasing and allocating the same VCPI allocation,
3255 * which is an error
3256 */
3257 if (WARN_ON(!prev_slots)) {
3258 DRM_ERROR("cannot allocate and release VCPI on [MST PORT:%p] in the same state\n",
3259 port);
3260 return -EINVAL;
3261 }
3262
3263 break;
3264 }
3265 }
3266 if (!vcpi)
3267 prev_slots = 0;
3268
3269 req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
3270
3271 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
3272 port->connector->base.id, port->connector->name,
3273 port, prev_slots, req_slots);
3274
3275 /* Add the new allocation to the state */
3276 if (!vcpi) {
3277 vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL);
3278 if (!vcpi)
3279 return -ENOMEM;
3280
3281 drm_dp_mst_get_port_malloc(port);
3282 vcpi->port = port;
3283 list_add(&vcpi->next, &topology_state->vcpis);
3284 }
3285 vcpi->vcpi = req_slots;
3286
3287 ret = req_slots;
3288 return ret;
3289}
3290EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
3291
3292/**
3293 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
3294 * @state: global atomic state
3295 * @mgr: MST topology manager for the port
3296 * @port: The port to release the VCPI slots from
3297 *
3298 * Releases any VCPI slots that have been allocated to a port in the atomic
3299 * state. Any atomic drivers which support MST must call this function in
3300 * their &drm_connector_helper_funcs.atomic_check() callback when the
3301 * connector will no longer have VCPI allocated (e.g. because its CRTC was
3302 * removed) when it had VCPI allocated in the previous atomic state.
3303 *
3304 * It is OK to call this even if @port has been removed from the system.
3305 * Additionally, it is OK to call this function multiple times on the same
3306 * @port as needed. It is not OK however, to call this function and
3307 * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
3308 * phase.
3309 *
3310 * See also:
3311 * drm_dp_atomic_find_vcpi_slots()
3312 * drm_dp_mst_atomic_check()
3313 *
3314 * Returns:
3315 * 0 if all slots for this port were added back to
3316 * &drm_dp_mst_topology_state.avail_slots or negative error code
3317 */
3318int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
3319 struct drm_dp_mst_topology_mgr *mgr,
3320 struct drm_dp_mst_port *port)
3321{
3322 struct drm_dp_mst_topology_state *topology_state;
3323 struct drm_dp_vcpi_allocation *pos;
3324 bool found = false;
3325
3326 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
3327 if (IS_ERR(topology_state))
3328 return PTR_ERR(topology_state);
3329
3330 list_for_each_entry(pos, &topology_state->vcpis, next) {
3331 if (pos->port == port) {
3332 found = true;
3333 break;
3334 }
3335 }
3336 if (WARN_ON(!found)) {
3337 DRM_ERROR("no VCPI for [MST PORT:%p] found in mst state %p\n",
3338 port, &topology_state->base);
3339 return -EINVAL;
3340 }
3341
3342 DRM_DEBUG_ATOMIC("[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi);
3343 if (pos->vcpi) {
3344 drm_dp_mst_put_port_malloc(port);
3345 pos->vcpi = 0;
3346 }
3347
3348 return 0;
3349}
3350EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
3351
3352/**
3353 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
3354 * @mgr: manager for this port
3355 * @port: port to allocate a virtual channel for.
3356 * @pbn: payload bandwidth number to request
3357 * @slots: returned number of slots for this PBN.
3358 */
3359bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
3360 struct drm_dp_mst_port *port, int pbn, int slots)
3361{
3362 int ret;
3363
3364 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3365 if (!port)
3366 return false;
3367
3368 if (slots < 0)
3369 return false;
3370
3371 if (port->vcpi.vcpi > 0) {
3372 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
3373 port->vcpi.vcpi, port->vcpi.pbn, pbn);
3374 if (pbn == port->vcpi.pbn) {
3375 drm_dp_mst_topology_put_port(port);
3376 return true;
3377 }
3378 }
3379
3380 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
3381 if (ret) {
3382 DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
3383 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
3384 goto out;
3385 }
3386 DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
3387 pbn, port->vcpi.num_slots);
3388
3389 /* Keep port allocated until its payload has been removed */
3390 drm_dp_mst_get_port_malloc(port);
3391 drm_dp_mst_topology_put_port(port);
3392 return true;
3393out:
3394 return false;
3395}
3396EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
3397
3398int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
3399{
3400 int slots = 0;
3401 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3402 if (!port)
3403 return slots;
3404
3405 slots = port->vcpi.num_slots;
3406 drm_dp_mst_topology_put_port(port);
3407 return slots;
3408}
3409EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
3410
3411/**
3412 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
3413 * @mgr: manager for this port
3414 * @port: unverified pointer to a port.
3415 *
3416 * This just resets the number of slots for the ports VCPI for later programming.
3417 */
3418void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
3419{
3420 /*
3421 * A port with VCPI will remain allocated until its VCPI is
3422 * released, no verified ref needed
3423 */
3424
3425 port->vcpi.num_slots = 0;
3426}
3427EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
3428
3429/**
3430 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
3431 * @mgr: manager for this port
3432 * @port: port to deallocate vcpi for
3433 *
3434 * This can be called unconditionally, regardless of whether
3435 * drm_dp_mst_allocate_vcpi() succeeded or not.
3436 */
3437void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
3438 struct drm_dp_mst_port *port)
3439{
3440 if (!port->vcpi.vcpi)
3441 return;
3442
3443 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
3444 port->vcpi.num_slots = 0;
3445 port->vcpi.pbn = 0;
3446 port->vcpi.aligned_pbn = 0;
3447 port->vcpi.vcpi = 0;
3448 drm_dp_mst_put_port_malloc(port);
3449}
3450EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
3451
3452static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
3453 int id, struct drm_dp_payload *payload)
3454{
3455 u8 payload_alloc[3], status;
3456 int ret;
3457 int retries = 0;
3458
3459 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
3460 DP_PAYLOAD_TABLE_UPDATED);
3461
3462 payload_alloc[0] = id;
3463 payload_alloc[1] = payload->start_slot;
3464 payload_alloc[2] = payload->num_slots;
3465
3466 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
3467 if (ret != 3) {
3468 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
3469 goto fail;
3470 }
3471
3472retry:
3473 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
3474 if (ret < 0) {
3475 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
3476 goto fail;
3477 }
3478
3479 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
3480 retries++;
3481 if (retries < 20) {
3482 usleep_range(10000, 20000);
3483 goto retry;
3484 }
3485 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
3486 ret = -EINVAL;
3487 goto fail;
3488 }
3489 ret = 0;
3490fail:
3491 return ret;
3492}
3493
3494
3495/**
3496 * drm_dp_check_act_status() - Check ACT handled status.
3497 * @mgr: manager to use
3498 *
3499 * Check the payload status bits in the DPCD for ACT handled completion.
3500 */
3501int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
3502{
3503 u8 status;
3504 int ret;
3505 int count = 0;
3506
3507 do {
3508 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
3509
3510 if (ret < 0) {
3511 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
3512 goto fail;
3513 }
3514
3515 if (status & DP_PAYLOAD_ACT_HANDLED)
3516 break;
3517 count++;
3518 udelay(100);
3519
3520 } while (count < 30);
3521
3522 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
3523 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
3524 ret = -EINVAL;
3525 goto fail;
3526 }
3527 return 0;
3528fail:
3529 return ret;
3530}
3531EXPORT_SYMBOL(drm_dp_check_act_status);
3532
3533/**
3534 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
3535 * @clock: dot clock for the mode
3536 * @bpp: bpp for the mode.
3537 *
3538 * This uses the formula in the spec to calculate the PBN value for a mode.
3539 */
3540int drm_dp_calc_pbn_mode(int clock, int bpp)
3541{
3542 u64 kbps;
3543 s64 peak_kbps;
3544 u32 numerator;
3545 u32 denominator;
3546
3547 kbps = clock * bpp;
3548
3549 /*
3550 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
3551 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
3552 * common multiplier to render an integer PBN for all link rate/lane
3553 * counts combinations
3554 * calculate
3555 * peak_kbps *= (1006/1000)
3556 * peak_kbps *= (64/54)
3557 * peak_kbps *= 8 convert to bytes
3558 */
3559
3560 numerator = 64 * 1006;
3561 denominator = 54 * 8 * 1000 * 1000;
3562
3563 kbps *= numerator;
3564 peak_kbps = drm_fixp_from_fraction(kbps, denominator);
3565
3566 return drm_fixp2int_ceil(peak_kbps);
3567}
3568EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
3569
3570static int test_calc_pbn_mode(void)
3571{
3572 int ret;
3573 ret = drm_dp_calc_pbn_mode(154000, 30);
3574 if (ret != 689) {
3575 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
3576 154000, 30, 689, ret);
3577 return -EINVAL;
3578 }
3579 ret = drm_dp_calc_pbn_mode(234000, 30);
3580 if (ret != 1047) {
3581 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
3582 234000, 30, 1047, ret);
3583 return -EINVAL;
3584 }
3585 ret = drm_dp_calc_pbn_mode(297000, 24);
3586 if (ret != 1063) {
3587 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
3588 297000, 24, 1063, ret);
3589 return -EINVAL;
3590 }
3591 return 0;
3592}
3593
3594/* we want to kick the TX after we've ack the up/down IRQs. */
3595static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
3596{
3597 queue_work(system_long_wq, &mgr->tx_work);
3598}
3599
3600static void drm_dp_mst_dump_mstb(struct seq_file *m,
3601 struct drm_dp_mst_branch *mstb)
3602{
3603 struct drm_dp_mst_port *port;
3604 int tabs = mstb->lct;
3605 char prefix[10];
3606 int i;
3607
3608 for (i = 0; i < tabs; i++)
3609 prefix[i] = '\t';
3610 prefix[i] = '\0';
3611
3612 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
3613 list_for_each_entry(port, &mstb->ports, next) {
3614 seq_printf(m, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->input, port->pdt, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
3615 if (port->mstb)
3616 drm_dp_mst_dump_mstb(m, port->mstb);
3617 }
3618}
3619
3620#define DP_PAYLOAD_TABLE_SIZE 64
3621
3622static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
3623 char *buf)
3624{
3625 int i;
3626
3627 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
3628 if (drm_dp_dpcd_read(mgr->aux,
3629 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
3630 &buf[i], 16) != 16)
3631 return false;
3632 }
3633 return true;
3634}
3635
3636static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
3637 struct drm_dp_mst_port *port, char *name,
3638 int namelen)
3639{
3640 struct edid *mst_edid;
3641
3642 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
3643 drm_edid_get_monitor_name(mst_edid, name, namelen);
3644}
3645
3646/**
3647 * drm_dp_mst_dump_topology(): dump topology to seq file.
3648 * @m: seq_file to dump output to
3649 * @mgr: manager to dump current topology for.
3650 *
3651 * helper to dump MST topology to a seq file for debugfs.
3652 */
3653void drm_dp_mst_dump_topology(struct seq_file *m,
3654 struct drm_dp_mst_topology_mgr *mgr)
3655{
3656 int i;
3657 struct drm_dp_mst_port *port;
3658
3659 mutex_lock(&mgr->lock);
3660 if (mgr->mst_primary)
3661 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
3662
3663 /* dump VCPIs */
3664 mutex_unlock(&mgr->lock);
3665
3666 mutex_lock(&mgr->payload_lock);
3667 seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
3668 mgr->max_payloads);
3669
3670 for (i = 0; i < mgr->max_payloads; i++) {
3671 if (mgr->proposed_vcpis[i]) {
3672 char name[14];
3673
3674 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
3675 fetch_monitor_name(mgr, port, name, sizeof(name));
3676 seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
3677 port->port_num, port->vcpi.vcpi,
3678 port->vcpi.num_slots,
3679 (*name != 0) ? name : "Unknown");
3680 } else
3681 seq_printf(m, "vcpi %d:unused\n", i);
3682 }
3683 for (i = 0; i < mgr->max_payloads; i++) {
3684 seq_printf(m, "payload %d: %d, %d, %d\n",
3685 i,
3686 mgr->payloads[i].payload_state,
3687 mgr->payloads[i].start_slot,
3688 mgr->payloads[i].num_slots);
3689
3690
3691 }
3692 mutex_unlock(&mgr->payload_lock);
3693
3694 mutex_lock(&mgr->lock);
3695 if (mgr->mst_primary) {
3696 u8 buf[DP_PAYLOAD_TABLE_SIZE];
3697 int ret;
3698
3699 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
3700 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
3701 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
3702 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
3703 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
3704 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
3705
3706 /* dump the standard OUI branch header */
3707 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
3708 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
3709 for (i = 0x3; i < 0x8 && buf[i]; i++)
3710 seq_printf(m, "%c", buf[i]);
3711 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
3712 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
3713 if (dump_dp_payload_table(mgr, buf))
3714 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
3715 }
3716
3717 mutex_unlock(&mgr->lock);
3718
3719}
3720EXPORT_SYMBOL(drm_dp_mst_dump_topology);
3721
3722static void drm_dp_tx_work(struct work_struct *work)
3723{
3724 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
3725
3726 mutex_lock(&mgr->qlock);
3727 if (!list_empty(&mgr->tx_msg_downq))
3728 process_single_down_tx_qlock(mgr);
3729 mutex_unlock(&mgr->qlock);
3730}
3731
3732static void drm_dp_destroy_connector_work(struct work_struct *work)
3733{
3734 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
3735 struct drm_dp_mst_port *port;
3736 bool send_hotplug = false;
3737 /*
3738 * Not a regular list traverse as we have to drop the destroy
3739 * connector lock before destroying the connector, to avoid AB->BA
3740 * ordering between this lock and the config mutex.
3741 */
3742 for (;;) {
3743 mutex_lock(&mgr->destroy_connector_lock);
3744 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
3745 if (!port) {
3746 mutex_unlock(&mgr->destroy_connector_lock);
3747 break;
3748 }
3749 list_del(&port->next);
3750 mutex_unlock(&mgr->destroy_connector_lock);
3751
3752 INIT_LIST_HEAD(&port->next);
3753
3754 mgr->cbs->destroy_connector(mgr, port->connector);
3755
3756 drm_dp_port_teardown_pdt(port, port->pdt);
3757 port->pdt = DP_PEER_DEVICE_NONE;
3758
3759 drm_dp_mst_put_port_malloc(port);
3760 send_hotplug = true;
3761 }
3762 if (send_hotplug)
3763 drm_kms_helper_hotplug_event(mgr->dev);
3764}
3765
3766static struct drm_private_state *
3767drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
3768{
3769 struct drm_dp_mst_topology_state *state, *old_state =
3770 to_dp_mst_topology_state(obj->state);
3771 struct drm_dp_vcpi_allocation *pos, *vcpi;
3772
3773 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
3774 if (!state)
3775 return NULL;
3776
3777 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
3778
3779 INIT_LIST_HEAD(&state->vcpis);
3780
3781 list_for_each_entry(pos, &old_state->vcpis, next) {
3782 /* Prune leftover freed VCPI allocations */
3783 if (!pos->vcpi)
3784 continue;
3785
3786 vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL);
3787 if (!vcpi)
3788 goto fail;
3789
3790 drm_dp_mst_get_port_malloc(vcpi->port);
3791 list_add(&vcpi->next, &state->vcpis);
3792 }
3793
3794 return &state->base;
3795
3796fail:
3797 list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) {
3798 drm_dp_mst_put_port_malloc(pos->port);
3799 kfree(pos);
3800 }
3801 kfree(state);
3802
3803 return NULL;
3804}
3805
3806static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
3807 struct drm_private_state *state)
3808{
3809 struct drm_dp_mst_topology_state *mst_state =
3810 to_dp_mst_topology_state(state);
3811 struct drm_dp_vcpi_allocation *pos, *tmp;
3812
3813 list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) {
3814 /* We only keep references to ports with non-zero VCPIs */
3815 if (pos->vcpi)
3816 drm_dp_mst_put_port_malloc(pos->port);
3817 kfree(pos);
3818 }
3819
3820 kfree(mst_state);
3821}
3822
3823static inline int
3824drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr,
3825 struct drm_dp_mst_topology_state *mst_state)
3826{
3827 struct drm_dp_vcpi_allocation *vcpi;
3828 int avail_slots = 63, payload_count = 0;
3829
3830 list_for_each_entry(vcpi, &mst_state->vcpis, next) {
3831 /* Releasing VCPI is always OK-even if the port is gone */
3832 if (!vcpi->vcpi) {
3833 DRM_DEBUG_ATOMIC("[MST PORT:%p] releases all VCPI slots\n",
3834 vcpi->port);
3835 continue;
3836 }
3837
3838 DRM_DEBUG_ATOMIC("[MST PORT:%p] requires %d vcpi slots\n",
3839 vcpi->port, vcpi->vcpi);
3840
3841 avail_slots -= vcpi->vcpi;
3842 if (avail_slots < 0) {
3843 DRM_DEBUG_ATOMIC("[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n",
3844 vcpi->port, mst_state,
3845 avail_slots + vcpi->vcpi);
3846 return -ENOSPC;
3847 }
3848
3849 if (++payload_count > mgr->max_payloads) {
3850 DRM_DEBUG_ATOMIC("[MST MGR:%p] state %p has too many payloads (max=%d)\n",
3851 mgr, mst_state, mgr->max_payloads);
3852 return -EINVAL;
3853 }
3854 }
3855 DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
3856 mgr, mst_state, avail_slots,
3857 63 - avail_slots);
3858
3859 return 0;
3860}
3861
3862/**
3863 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
3864 * atomic update is valid
3865 * @state: Pointer to the new &struct drm_dp_mst_topology_state
3866 *
3867 * Checks the given topology state for an atomic update to ensure that it's
3868 * valid. This includes checking whether there's enough bandwidth to support
3869 * the new VCPI allocations in the atomic update.
3870 *
3871 * Any atomic drivers supporting DP MST must make sure to call this after
3872 * checking the rest of their state in their
3873 * &drm_mode_config_funcs.atomic_check() callback.
3874 *
3875 * See also:
3876 * drm_dp_atomic_find_vcpi_slots()
3877 * drm_dp_atomic_release_vcpi_slots()
3878 *
3879 * Returns:
3880 *
3881 * 0 if the new state is valid, negative error code otherwise.
3882 */
3883int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
3884{
3885 struct drm_dp_mst_topology_mgr *mgr;
3886 struct drm_dp_mst_topology_state *mst_state;
3887 int i, ret = 0;
3888
3889 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
3890 ret = drm_dp_mst_atomic_check_topology_state(mgr, mst_state);
3891 if (ret)
3892 break;
3893 }
3894
3895 return ret;
3896}
3897EXPORT_SYMBOL(drm_dp_mst_atomic_check);
3898
3899const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
3900 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
3901 .atomic_destroy_state = drm_dp_mst_destroy_state,
3902};
3903EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
3904
3905/**
3906 * drm_atomic_get_mst_topology_state: get MST topology state
3907 *
3908 * @state: global atomic state
3909 * @mgr: MST topology manager, also the private object in this case
3910 *
3911 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
3912 * state vtable so that the private object state returned is that of a MST
3913 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
3914 * to care of the locking, so warn if don't hold the connection_mutex.
3915 *
3916 * RETURNS:
3917 *
3918 * The MST topology state or error pointer.
3919 */
3920struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
3921 struct drm_dp_mst_topology_mgr *mgr)
3922{
3923 struct drm_device *dev = mgr->dev;
3924
3925 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
3926 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
3927}
3928EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
3929
3930/**
3931 * drm_dp_mst_topology_mgr_init - initialise a topology manager
3932 * @mgr: manager struct to initialise
3933 * @dev: device providing this structure - for i2c addition.
3934 * @aux: DP helper aux channel to talk to this device
3935 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
3936 * @max_payloads: maximum number of payloads this GPU can source
3937 * @conn_base_id: the connector object ID the MST device is connected to.
3938 *
3939 * Return 0 for success, or negative error code on failure
3940 */
3941int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
3942 struct drm_device *dev, struct drm_dp_aux *aux,
3943 int max_dpcd_transaction_bytes,
3944 int max_payloads, int conn_base_id)
3945{
3946 struct drm_dp_mst_topology_state *mst_state;
3947
3948 mutex_init(&mgr->lock);
3949 mutex_init(&mgr->qlock);
3950 mutex_init(&mgr->payload_lock);
3951 mutex_init(&mgr->destroy_connector_lock);
3952 INIT_LIST_HEAD(&mgr->tx_msg_downq);
3953 INIT_LIST_HEAD(&mgr->destroy_connector_list);
3954 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
3955 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
3956 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
3957 init_waitqueue_head(&mgr->tx_waitq);
3958 mgr->dev = dev;
3959 mgr->aux = aux;
3960 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
3961 mgr->max_payloads = max_payloads;
3962 mgr->conn_base_id = conn_base_id;
3963 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
3964 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
3965 return -EINVAL;
3966 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
3967 if (!mgr->payloads)
3968 return -ENOMEM;
3969 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
3970 if (!mgr->proposed_vcpis)
3971 return -ENOMEM;
3972 set_bit(0, &mgr->payload_mask);
3973 if (test_calc_pbn_mode() < 0)
3974 DRM_ERROR("MST PBN self-test failed\n");
3975
3976 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
3977 if (mst_state == NULL)
3978 return -ENOMEM;
3979
3980 mst_state->mgr = mgr;
3981 INIT_LIST_HEAD(&mst_state->vcpis);
3982
3983 drm_atomic_private_obj_init(dev, &mgr->base,
3984 &mst_state->base,
3985 &drm_dp_mst_topology_state_funcs);
3986
3987 return 0;
3988}
3989EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
3990
3991/**
3992 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
3993 * @mgr: manager to destroy
3994 */
3995void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
3996{
3997 drm_dp_mst_topology_mgr_set_mst(mgr, false);
3998 flush_work(&mgr->work);
3999 flush_work(&mgr->destroy_connector_work);
4000 mutex_lock(&mgr->payload_lock);
4001 kfree(mgr->payloads);
4002 mgr->payloads = NULL;
4003 kfree(mgr->proposed_vcpis);
4004 mgr->proposed_vcpis = NULL;
4005 mutex_unlock(&mgr->payload_lock);
4006 mgr->dev = NULL;
4007 mgr->aux = NULL;
4008 drm_atomic_private_obj_fini(&mgr->base);
4009 mgr->funcs = NULL;
4010}
4011EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
4012
4013static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
4014{
4015 int i;
4016
4017 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
4018 return false;
4019
4020 for (i = 0; i < num - 1; i++) {
4021 if (msgs[i].flags & I2C_M_RD ||
4022 msgs[i].len > 0xff)
4023 return false;
4024 }
4025
4026 return msgs[num - 1].flags & I2C_M_RD &&
4027 msgs[num - 1].len <= 0xff;
4028}
4029
4030/* I2C device */
4031static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
4032 int num)
4033{
4034 struct drm_dp_aux *aux = adapter->algo_data;
4035 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
4036 struct drm_dp_mst_branch *mstb;
4037 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
4038 unsigned int i;
4039 struct drm_dp_sideband_msg_req_body msg;
4040 struct drm_dp_sideband_msg_tx *txmsg = NULL;
4041 int ret;
4042
4043 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
4044 if (!mstb)
4045 return -EREMOTEIO;
4046
4047 if (!remote_i2c_read_ok(msgs, num)) {
4048 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
4049 ret = -EIO;
4050 goto out;
4051 }
4052
4053 memset(&msg, 0, sizeof(msg));
4054 msg.req_type = DP_REMOTE_I2C_READ;
4055 msg.u.i2c_read.num_transactions = num - 1;
4056 msg.u.i2c_read.port_number = port->port_num;
4057 for (i = 0; i < num - 1; i++) {
4058 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
4059 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
4060 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
4061 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
4062 }
4063 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
4064 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
4065
4066 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
4067 if (!txmsg) {
4068 ret = -ENOMEM;
4069 goto out;
4070 }
4071
4072 txmsg->dst = mstb;
4073 drm_dp_encode_sideband_req(&msg, txmsg);
4074
4075 drm_dp_queue_down_tx(mgr, txmsg);
4076
4077 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
4078 if (ret > 0) {
4079
4080 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
4081 ret = -EREMOTEIO;
4082 goto out;
4083 }
4084 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
4085 ret = -EIO;
4086 goto out;
4087 }
4088 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
4089 ret = num;
4090 }
4091out:
4092 kfree(txmsg);
4093 drm_dp_mst_topology_put_mstb(mstb);
4094 return ret;
4095}
4096
4097static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
4098{
4099 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
4100 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
4101 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
4102 I2C_FUNC_10BIT_ADDR;
4103}
4104
4105static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
4106 .functionality = drm_dp_mst_i2c_functionality,
4107 .master_xfer = drm_dp_mst_i2c_xfer,
4108};
4109
4110/**
4111 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
4112 * @aux: DisplayPort AUX channel
4113 *
4114 * Returns 0 on success or a negative error code on failure.
4115 */
4116static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
4117{
4118 aux->ddc.algo = &drm_dp_mst_i2c_algo;
4119 aux->ddc.algo_data = aux;
4120 aux->ddc.retries = 3;
4121
4122 aux->ddc.class = I2C_CLASS_DDC;
4123 aux->ddc.owner = THIS_MODULE;
4124 aux->ddc.dev.parent = aux->dev;
4125 aux->ddc.dev.of_node = aux->dev->of_node;
4126
4127 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
4128 sizeof(aux->ddc.name));
4129
4130 return i2c_add_adapter(&aux->ddc);
4131}
4132
4133/**
4134 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
4135 * @aux: DisplayPort AUX channel
4136 */
4137static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
4138{
4139 i2c_del_adapter(&aux->ddc);
4140}