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Merge tag 'for-linus-hmm' of git://git.kernel.org/pub/scm/linux/kernel/git/rdma/rdma
[mirror_ubuntu-focal-kernel.git] / drivers / gpu / drm / drm_dp_mst_topology.c
CommitLineData
ad7f8a1f
DA		 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
ad7f8a1f 23#include <linux/delay.h>
ad7f8a1f 24#include <linux/errno.h>
580fc13f
JN		 25#include <linux/i2c.h>
26#include <linux/init.h>
27#include <linux/kernel.h>
ad7f8a1f 28#include <linux/sched.h>
75bc08ab 29#include <linux/seq_file.h>
ad7f8a1f 30
a4370c77
VS		 31#include <drm/drm_atomic.h>
32#include <drm/drm_atomic_helper.h>
580fc13f
JN		 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>
fcd70cd3 37#include <drm/drm_probe_helper.h>
ad7f8a1f 38
562836a2
VS		 39#include "drm_crtc_helper_internal.h"
40
ad7f8a1f
DA		 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
d0757afd 52static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
ad7f8a1f
DA		 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
562836a2
VS		 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);
ad7f8a1f
DA		 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
68d8c9fc
DA		 65static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
66 struct drm_dp_mst_branch *mstb);
ad7f8a1f
DA		 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);
3dadbd29
VS		 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
ad7f8a1f
DA		 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;
0bb9c2b2
DP		 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;
ad7f8a1f
DA		 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
636c4c3e
ID		 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
ad7f8a1f
DA		 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];
a4c30a48 507 idx++;
ad7f8a1f
DA		 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
0bb9c2b2
DP		 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
ad7f8a1f
DA		 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
45bbda1e 635 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
ad7f8a1f
DA		 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);
0bb9c2b2
DP		 657 case DP_POWER_DOWN_PHY:
658 case DP_POWER_UP_PHY:
659 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
ad7f8a1f 660 default:
3dadbd29
VS		 661 DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type,
662 drm_dp_mst_req_type_str(msg->req_type));
ad7f8a1f
DA		 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:
3dadbd29
VS		 729 DRM_ERROR("Got unknown request 0x%02x (%s)\n", msg->req_type,
730 drm_dp_mst_req_type_str(msg->req_type));
ad7f8a1f
DA		 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,
ef8f9bea
LY		 770 u8 vcpi, uint16_t pbn,
771 u8 number_sdp_streams,
772 u8 *sdp_stream_sink)
ad7f8a1f
DA		 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;
ef8f9bea
LY		 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);
ad7f8a1f
DA		 783 drm_dp_encode_sideband_req(&req, msg);
784 msg->path_msg = true;
785 return 0;
786}
787
0bb9c2b2
DP		 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
ad7f8a1f
DA		 804static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
805 struct drm_dp_vcpi *vcpi)
806{
dfda0df3 807 int ret, vcpi_ret;
ad7f8a1f
DA		 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
dfda0df3
DA		 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
ad7f8a1f 824 set_bit(ret, &mgr->payload_mask);
dfda0df3
DA		 825 set_bit(vcpi_ret, &mgr->vcpi_mask);
826 vcpi->vcpi = vcpi_ret + 1;
ad7f8a1f
DA		 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,
dfda0df3 834 int vcpi)
ad7f8a1f 835{
dfda0df3
DA		 836 int i;
837 if (vcpi == 0)
ad7f8a1f
DA		 838 return;
839
840 mutex_lock(&mgr->payload_lock);
dfda0df3
DA		 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 }
ad7f8a1f
DA		 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{
992d38cc 857 unsigned int state;
cd961bb9
DV		 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 */
992d38cc
CW		 864 state = READ_ONCE(txmsg->state);
865 return (state == DRM_DP_SIDEBAND_TX_RX ||
866 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
ad7f8a1f
DA		 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);
ebcc0e6b
LP		 919 kref_init(&mstb->topology_kref);
920 kref_init(&mstb->malloc_kref);
ad7f8a1f
DA		 921 return mstb;
922}
923
91a25e46
ML		 924static void drm_dp_free_mst_branch_device(struct kref *kref)
925{
ebcc0e6b
LP		 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
91a25e46
ML		 932 kfree(mstb);
933}
934
ebcc0e6b
LP		 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
1e55a53a 950 * of the topology until its topology refcount reaches zero. Additionally,
ebcc0e6b
LP		 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
1e55a53a
MR		 988 * refcount of its children, and increments the malloc refcount of its
989 * parent. Additionally, every payload increments the malloc refcount of its
ebcc0e6b
LP		 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
1e55a53a 1006 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
ebcc0e6b 1007 * is still accessible from memory. This also means port #3 has not yet
1e55a53a 1008 * decremented the malloc refcount of MSTB #3, so its &struct
ebcc0e6b
LP		 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
ad7f8a1f
DA		 1111static void drm_dp_destroy_mst_branch_device(struct kref *kref)
1112{
ebcc0e6b
LP		 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;
ad7f8a1f
DA		 1116 struct drm_dp_mst_port *port, *tmp;
1117 bool wake_tx = false;
1118
ebcc0e6b 1119 mutex_lock(&mgr->lock);
ad7f8a1f
DA		 1120 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
1121 list_del(&port->next);
d0757afd 1122 drm_dp_mst_topology_put_port(port);
ad7f8a1f 1123 }
ebcc0e6b 1124 mutex_unlock(&mgr->lock);
ad7f8a1f
DA		 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)
68e989dc 1141 wake_up_all(&mstb->mgr->tx_waitq);
91a25e46 1142
ebcc0e6b 1143 drm_dp_mst_put_mstb_malloc(mstb);
ad7f8a1f
DA		 1144}
1145
ebcc0e6b
LP		 1146/**
1147 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1e55a53a 1148 * branch device unless it's zero
ebcc0e6b
LP		 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)
ad7f8a1f 1170{
ebcc0e6b
LP		 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;
ad7f8a1f
DA		 1178}
1179
ebcc0e6b
LP		 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}
ad7f8a1f
DA		 1220
1221static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
1222{
0391359d
DV		 1223 struct drm_dp_mst_branch *mstb;
1224
ad7f8a1f
DA		 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:
0391359d 1232 mstb = port->mstb;
ad7f8a1f 1233 port->mstb = NULL;
d0757afd 1234 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 1235 break;
1236 }
1237}
1238
1239static void drm_dp_destroy_port(struct kref *kref)
1240{
ebcc0e6b
LP		 1241 struct drm_dp_mst_port *port =
1242 container_of(kref, struct drm_dp_mst_port, topology_kref);
ad7f8a1f 1243 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
df4839fd 1244
ad7f8a1f 1245 if (!port->input) {
c6a0aed4 1246 kfree(port->cached_edid);
6b8eeca6 1247
df4839fd
DA		 1248 /*
1249 * The only time we don't have a connector
1250 * on an output port is if the connector init
1251 * fails.
1252 */
6b8eeca6 1253 if (port->connector) {
df4839fd
DA		 1254 /* we can't destroy the connector here, as
1255 * we might be holding the mode_config.mutex
1256 * from an EDID retrieval */
1257
6b8eeca6 1258 mutex_lock(&mgr->destroy_connector_lock);
4772ff03 1259 list_add(&port->next, &mgr->destroy_connector_list);
6b8eeca6
DA		 1260 mutex_unlock(&mgr->destroy_connector_lock);
1261 schedule_work(&mgr->destroy_connector_work);
4772ff03 1262 return;
6b8eeca6 1263 }
df4839fd
DA		 1264 /* no need to clean up vcpi
1265 * as if we have no connector we never setup a vcpi */
ad7f8a1f 1266 drm_dp_port_teardown_pdt(port, port->pdt);
36e3fa6a 1267 port->pdt = DP_PEER_DEVICE_NONE;
ad7f8a1f 1268 }
ebcc0e6b
LP		 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
1e55a53a 1274 * port unless it's zero
ebcc0e6b
LP		 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;
ad7f8a1f
DA		 1304}
1305
ebcc0e6b
LP		 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 */
d0757afd 1337static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
ad7f8a1f 1338{
ebcc0e6b
LP		 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);
ad7f8a1f
DA		 1342}
1343
d0757afd
LP		 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)
ad7f8a1f
DA		 1347{
1348 struct drm_dp_mst_port *port;
1349 struct drm_dp_mst_branch *rmstb;
ebcc0e6b
LP		 1350
1351 if (to_find == mstb)
ad7f8a1f 1352 return mstb;
ebcc0e6b 1353
ad7f8a1f
DA		 1354 list_for_each_entry(port, &mstb->ports, next) {
1355 if (port->mstb) {
d0757afd
LP		 1356 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1357 port->mstb, to_find);
ad7f8a1f
DA		 1358 if (rmstb)
1359 return rmstb;
1360 }
1361 }
1362 return NULL;
1363}
1364
d0757afd
LP		 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)
ad7f8a1f
DA		 1368{
1369 struct drm_dp_mst_branch *rmstb = NULL;
ebcc0e6b 1370
ad7f8a1f 1371 mutex_lock(&mgr->lock);
ebcc0e6b 1372 if (mgr->mst_primary) {
d0757afd
LP		 1373 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1374 mgr->mst_primary, mstb);
ebcc0e6b
LP		 1375
1376 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
1377 rmstb = NULL;
1378 }
ad7f8a1f
DA		 1379 mutex_unlock(&mgr->lock);
1380 return rmstb;
1381}
1382
ebcc0e6b
LP		 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)
ad7f8a1f
DA		 1386{
1387 struct drm_dp_mst_port *port, *mport;
1388
1389 list_for_each_entry(port, &mstb->ports, next) {
ebcc0e6b 1390 if (port == to_find)
ad7f8a1f 1391 return port;
ebcc0e6b 1392
ad7f8a1f 1393 if (port->mstb) {
ebcc0e6b
LP		 1394 mport = drm_dp_mst_topology_get_port_validated_locked(
1395 port->mstb, to_find);
ad7f8a1f
DA		 1396 if (mport)
1397 return mport;
1398 }
1399 }
1400 return NULL;
1401}
1402
d0757afd
LP		 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)
ad7f8a1f
DA		 1406{
1407 struct drm_dp_mst_port *rport = NULL;
ebcc0e6b 1408
ad7f8a1f 1409 mutex_lock(&mgr->lock);
ebcc0e6b
LP		 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 }
ad7f8a1f
DA		 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;
ebcc0e6b 1424 int ret;
ad7f8a1f
DA		 1425
1426 list_for_each_entry(port, &mstb->ports, next) {
1427 if (port->port_num == port_num) {
ebcc0e6b
LP		 1428 ret = drm_dp_mst_topology_try_get_port(port);
1429 return ret ? port : NULL;
ad7f8a1f
DA		 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{
75af4c8c 1444 int parent_lct = port->parent->lct;
ad7f8a1f 1445 int shift = 4;
75af4c8c
ML		 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;
ad7f8a1f
DA		 1450 } else
1451 rad[0] = 0;
1452
1453 rad[idx] |= port->port_num << shift;
75af4c8c 1454 return parent_lct + 1;
ad7f8a1f
DA		 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);
22a07038
JM		 1475 if (port->mstb) {
1476 port->mstb->mgr = port->mgr;
1477 port->mstb->port_parent = port;
ebcc0e6b
LP		 1478 /*
1479 * Make sure this port's memory allocation stays
1e55a53a 1480 * around until its child MSTB releases it
ebcc0e6b
LP		 1481 */
1482 drm_dp_mst_get_port_malloc(port);
ad7f8a1f 1483
22a07038
JM		 1484 send_link = true;
1485 }
ad7f8a1f
DA		 1486 break;
1487 }
1488 return send_link;
1489}
1490
562836a2
VS		 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
5e93b820 1537static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
ad7f8a1f
DA		 1538{
1539 int ret;
5e93b820
HW		 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);
ad7f8a1f
DA		 1558 }
1559 }
1560}
1561
1c960876
DA		 1562static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1563 int pnum,
d87af4d1
RS		 1564 char *proppath,
1565 size_t proppath_size)
ad7f8a1f
DA		 1566{
1567 int i;
1568 char temp[8];
d87af4d1 1569 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
ad7f8a1f
DA		 1570 for (i = 0; i < (mstb->lct - 1); i++) {
1571 int shift = (i % 2) ? 0 : 4;
7a11a334 1572 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
d87af4d1
RS		 1573 snprintf(temp, sizeof(temp), "-%d", port_num);
1574 strlcat(proppath, temp, proppath_size);
ad7f8a1f 1575 }
1c960876 1576 snprintf(temp, sizeof(temp), "-%d", pnum);
d87af4d1 1577 strlcat(proppath, temp, proppath_size);
ad7f8a1f
DA		 1578}
1579
562836a2
VS		 1580/**
1581 * drm_dp_mst_connector_late_register() - Late MST connector registration
63b87c31 1582 * @connector: The MST connector
562836a2
VS		 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
63b87c31 1604 * @connector: The MST connector
562836a2
VS		 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
ad7f8a1f 1620static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
7b0a89a6 1621 struct drm_device *dev,
ad7f8a1f
DA		 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;
ebcc0e6b 1629
ad7f8a1f
DA		 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;
ebcc0e6b
LP		 1635 kref_init(&port->topology_kref);
1636 kref_init(&port->malloc_kref);
ad7f8a1f
DA		 1637 port->parent = mstb;
1638 port->port_num = port_msg->port_number;
1639 port->mgr = mstb->mgr;
1640 port->aux.name = "DPMST";
7b0a89a6 1641 port->aux.dev = dev->dev;
562836a2 1642 port->aux.is_remote = true;
ebcc0e6b
LP		 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
ad7f8a1f
DA		 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;
ad7f8a1f
DA		 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);
ebcc0e6b 1669 drm_dp_mst_topology_get_port(port);
ad7f8a1f
DA		 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) {
3d76df63
LP		 1676 if (!port->input) {
1677 drm_dp_send_enum_path_resources(mstb->mgr,
1678 mstb, port);
1679 }
ad7f8a1f 1680 } else {
ad7f8a1f 1681 port->available_pbn = 0;
3d76df63 1682 }
ad7f8a1f
DA		 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);
68d8c9fc 1689 if (ret == true)
ad7f8a1f 1690 drm_dp_send_link_address(mstb->mgr, port->mstb);
ad7f8a1f
DA		 1691 }
1692
1693 if (created && !port->input) {
1694 char proppath[255];
1c960876 1695
3d76df63
LP		 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);
df4839fd
DA		 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 */
d0757afd 1707 drm_dp_mst_topology_put_port(port);
df4839fd
DA		 1708 goto out;
1709 }
4da5caa6
VS		 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) {
3d76df63
LP		 1713 port->cached_edid = drm_get_edid(port->connector,
1714 &port->aux.ddc);
97e14fbe 1715 drm_connector_set_tile_property(port->connector);
8ae22cb4 1716 }
d9515c5e 1717 (*mstb->mgr->cbs->register_connector)(port->connector);
ad7f8a1f 1718 }
8ae22cb4 1719
df4839fd 1720out:
ad7f8a1f 1721 /* put reference to this port */
d0757afd 1722 drm_dp_mst_topology_put_port(port);
ad7f8a1f
DA		 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) {
8ae22cb4 1745 dowork = true;
ad7f8a1f 1746 } else {
ad7f8a1f
DA		 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
d0757afd 1757 drm_dp_mst_topology_put_port(port);
ad7f8a1f
DA		 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;
ebcc0e6b 1768 int i, ret;
ad7f8a1f 1769 /* find the port by iterating down */
9eb1e57f
DA		 1770
1771 mutex_lock(&mgr->lock);
ad7f8a1f
DA		 1772 mstb = mgr->mst_primary;
1773
23d80039
SL		 1774 if (!mstb)
1775 goto out;
1776
ad7f8a1f
DA		 1777 for (i = 0; i < lct - 1; i++) {
1778 int shift = (i % 2) ? 0 : 4;
7a11a334 1779 int port_num = (rad[i / 2] >> shift) & 0xf;
ad7f8a1f
DA		 1780
1781 list_for_each_entry(port, &mstb->ports, next) {
1782 if (port->port_num == port_num) {
30730c7f
AR		 1783 mstb = port->mstb;
1784 if (!mstb) {
ad7f8a1f 1785 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
30730c7f 1786 goto out;
ad7f8a1f
DA		 1787 }
1788
ad7f8a1f
DA		 1789 break;
1790 }
1791 }
1792 }
ebcc0e6b
LP		 1793 ret = drm_dp_mst_topology_try_get_mstb(mstb);
1794 if (!ret)
1795 mstb = NULL;
30730c7f 1796out:
9eb1e57f 1797 mutex_unlock(&mgr->lock);
ad7f8a1f
DA		 1798 return mstb;
1799}
1800
bd934320
ML		 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
5e93b820
HW		 1808 if (memcmp(mstb->guid, guid, 16) == 0)
1809 return mstb;
1810
1811
bd934320
ML		 1812 list_for_each_entry(port, &mstb->ports, next) {
1813 if (!port->mstb)
1814 continue;
1815
bd934320
ML		 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
de6d6818
LP		 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)
bd934320
ML		 1828{
1829 struct drm_dp_mst_branch *mstb;
ebcc0e6b 1830 int ret;
bd934320
ML		 1831
1832 /* find the port by iterating down */
1833 mutex_lock(&mgr->lock);
1834
5e93b820 1835 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
ebcc0e6b
LP		 1836 if (mstb) {
1837 ret = drm_dp_mst_topology_try_get_mstb(mstb);
1838 if (!ret)
1839 mstb = NULL;
1840 }
bd934320
ML		 1841
1842 mutex_unlock(&mgr->lock);
1843 return mstb;
1844}
1845
ad7f8a1f
DA		 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;
9254ec49 1850 struct drm_dp_mst_branch *mstb_child;
68d8c9fc 1851 if (!mstb->link_address_sent)
ad7f8a1f 1852 drm_dp_send_link_address(mgr, mstb);
68d8c9fc 1853
ad7f8a1f
DA		 1854 list_for_each_entry(port, &mstb->ports, next) {
1855 if (port->input)
1856 continue;
1857
8ae22cb4 1858 if (!port->ddps)
ad7f8a1f
DA		 1859 continue;
1860
1861 if (!port->available_pbn)
1862 drm_dp_send_enum_path_resources(mgr, mstb, port);
1863
9254ec49 1864 if (port->mstb) {
d0757afd
LP		 1865 mstb_child = drm_dp_mst_topology_get_mstb_validated(
1866 mgr, port->mstb);
9254ec49
DV		 1867 if (mstb_child) {
1868 drm_dp_check_and_send_link_address(mgr, mstb_child);
d0757afd 1869 drm_dp_mst_topology_put_mstb(mstb_child);
9254ec49
DV		 1870 }
1871 }
ad7f8a1f
DA		 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);
9254ec49 1878 struct drm_dp_mst_branch *mstb;
ebcc0e6b 1879 int ret;
ad7f8a1f 1880
9254ec49
DV		 1881 mutex_lock(&mgr->lock);
1882 mstb = mgr->mst_primary;
1883 if (mstb) {
ebcc0e6b
LP		 1884 ret = drm_dp_mst_topology_try_get_mstb(mstb);
1885 if (!ret)
1886 mstb = NULL;
9254ec49
DV		 1887 }
1888 mutex_unlock(&mgr->lock);
1889 if (mstb) {
1890 drm_dp_check_and_send_link_address(mgr, mstb);
d0757afd 1891 drm_dp_mst_topology_put_mstb(mstb);
9254ec49 1892 }
ad7f8a1f
DA		 1893}
1894
1895static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1896 u8 *guid)
1897{
e38e1289 1898 u64 salt;
ad7f8a1f 1899
e38e1289
VS		 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;
ad7f8a1f
DA		 1909}
1910
ad7f8a1f
DA		 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}
ad7f8a1f
DA		 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);
ad7f8a1f
DA		 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;
bd934320 1960 u8 req_type;
ad7f8a1f
DA		 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 }
bd934320
ML		 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;
ad7f8a1f
DA		 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
bf3719c0
DL		 2004 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
2005
ad7f8a1f
DA		 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
ad7f8a1f
DA		 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
cd961bb9
DV		 2056 WARN_ON(!mutex_is_locked(&mgr->qlock));
2057
ad7f8a1f 2058 /* construct a chunk from the first msg in the tx_msg queue */
cb021a3e 2059 if (list_empty(&mgr->tx_msg_downq))
ad7f8a1f 2060 return;
ad7f8a1f
DA		 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;
68e989dc 2073 wake_up_all(&mgr->tx_waitq);
ad7f8a1f 2074 }
ad7f8a1f
DA		 2075}
2076
2077/* called holding qlock */
1f16ee7f
ML		 2078static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2079 struct drm_dp_sideband_msg_tx *txmsg)
ad7f8a1f 2080{
ad7f8a1f
DA		 2081 int ret;
2082
2083 /* construct a chunk from the first msg in the tx_msg queue */
ad7f8a1f 2084 ret = process_single_tx_qlock(mgr, txmsg, true);
1f16ee7f
ML		 2085
2086 if (ret != 1)
ad7f8a1f 2087 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1f16ee7f 2088
d8fd3722
ID		 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 }
ad7f8a1f
DA		 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);
cb021a3e 2101 if (list_is_singular(&mgr->tx_msg_downq))
ad7f8a1f
DA		 2102 process_single_down_tx_qlock(mgr);
2103 mutex_unlock(&mgr->qlock);
2104}
2105
68d8c9fc
DA		 2106static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2107 struct drm_dp_mst_branch *mstb)
ad7f8a1f
DA		 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)
68d8c9fc 2115 return;
ad7f8a1f
DA		 2116
2117 txmsg->dst = mstb;
2118 len = build_link_address(txmsg);
2119
68d8c9fc 2120 mstb->link_address_sent = true;
ad7f8a1f
DA		 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
45bbda1e 2127 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
ad7f8a1f 2128 DRM_DEBUG_KMS("link address nak received\n");
45bbda1e 2129 } else {
ad7f8a1f
DA		 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 }
5e93b820
HW		 2143
2144 drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
2145
ad7f8a1f
DA		 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 }
16bff572 2149 drm_kms_helper_hotplug_event(mgr->dev);
ad7f8a1f 2150 }
68d8c9fc
DA		 2151 } else {
2152 mstb->link_address_sent = false;
ad7f8a1f 2153 DRM_DEBUG_KMS("link address failed %d\n", ret);
68d8c9fc 2154 }
ad7f8a1f
DA		 2155
2156 kfree(txmsg);
ad7f8a1f
DA		 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) {
45bbda1e 2178 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
ad7f8a1f 2179 DRM_DEBUG_KMS("enum path resources nak received\n");
45bbda1e 2180 } else {
ad7f8a1f
DA		 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
91a25e46
ML		 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
56d1c14e
LP		 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)
91a25e46
ML		 2216{
2217 struct drm_dp_mst_branch *rmstb = NULL;
2218 struct drm_dp_mst_port *found_port;
56d1c14e 2219
91a25e46 2220 mutex_lock(&mgr->lock);
56d1c14e
LP		 2221 if (!mgr->mst_primary)
2222 goto out;
2223
2224 do {
91a25e46 2225 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
56d1c14e
LP		 2226 if (!found_port)
2227 break;
91a25e46 2228
56d1c14e 2229 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
91a25e46 2230 rmstb = found_port->parent;
56d1c14e
LP		 2231 *port_num = found_port->port_num;
2232 } else {
2233 /* Search again, starting from this parent */
2234 mstb = found_port->parent;
91a25e46 2235 }
56d1c14e
LP		 2236 } while (!rmstb);
2237out:
91a25e46
ML		 2238 mutex_unlock(&mgr->lock);
2239 return rmstb;
2240}
2241
8fa6a425
TR		 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)
ad7f8a1f
DA		 2246{
2247 struct drm_dp_sideband_msg_tx *txmsg;
2248 struct drm_dp_mst_branch *mstb;
91a25e46 2249 int len, ret, port_num;
ef8f9bea
LY		 2250 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
2251 int i;
ad7f8a1f 2252
91a25e46 2253 port_num = port->port_num;
d0757afd 2254 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
91a25e46 2255 if (!mstb) {
de6d6818
LP		 2256 mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
2257 port->parent,
2258 &port_num);
91a25e46 2259
cfe9f903 2260 if (!mstb)
91a25e46
ML		 2261 return -EINVAL;
2262 }
ad7f8a1f
DA		 2263
2264 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2265 if (!txmsg) {
2266 ret = -ENOMEM;
2267 goto fail_put;
2268 }
2269
ef8f9bea
LY		 2270 for (i = 0; i < port->num_sdp_streams; i++)
2271 sinks[i] = i;
2272
ad7f8a1f 2273 txmsg->dst = mstb;
91a25e46 2274 len = build_allocate_payload(txmsg, port_num,
ad7f8a1f 2275 id,
ef8f9bea 2276 pbn, port->num_sdp_streams, sinks);
ad7f8a1f
DA		 2277
2278 drm_dp_queue_down_tx(mgr, txmsg);
2279
56d1c14e
LP		 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 */
ad7f8a1f
DA		 2288 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2289 if (ret > 0) {
45bbda1e 2290 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
ad7f8a1f 2291 ret = -EINVAL;
de6d6818 2292 else
ad7f8a1f
DA		 2293 ret = 0;
2294 }
2295 kfree(txmsg);
2296fail_put:
d0757afd 2297 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 2298 return ret;
2299}
2300
0bb9c2b2
DP		 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
d0757afd 2307 port = drm_dp_mst_topology_get_port_validated(mgr, port);
0bb9c2b2
DP		 2308 if (!port)
2309 return -EINVAL;
2310
2311 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2312 if (!txmsg) {
d0757afd 2313 drm_dp_mst_topology_put_port(port);
0bb9c2b2
DP		 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) {
45bbda1e 2323 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
0bb9c2b2
DP		 2324 ret = -EINVAL;
2325 else
2326 ret = 0;
2327 }
2328 kfree(txmsg);
d0757afd 2329 drm_dp_mst_topology_put_port(port);
0bb9c2b2
DP		 2330
2331 return ret;
2332}
2333EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
2334
ad7f8a1f
DA		 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
8fa6a425
TR		 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)
ad7f8a1f
DA		 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
8fa6a425
TR		 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)
ad7f8a1f
DA		 2367{
2368 DRM_DEBUG_KMS("\n");
1e55a53a 2369 /* it's okay for these to fail */
ad7f8a1f
DA		 2370 if (port) {
2371 drm_dp_payload_send_msg(mgr, port, id, 0);
2372 }
2373
2374 drm_dp_dpcd_write_payload(mgr, id, payload);
dfda0df3 2375 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
ad7f8a1f
DA		 2376 return 0;
2377}
2378
8fa6a425
TR		 2379static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
2380 int id,
2381 struct drm_dp_payload *payload)
ad7f8a1f
DA		 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{
ad7f8a1f
DA		 2402 struct drm_dp_payload req_payload;
2403 struct drm_dp_mst_port *port;
cfe9f903
LP		 2404 int i, j;
2405 int cur_slots = 1;
ad7f8a1f
DA		 2406
2407 mutex_lock(&mgr->payload_lock);
2408 for (i = 0; i < mgr->max_payloads; i++) {
706246c7
LP		 2409 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
2410 struct drm_dp_payload *payload = &mgr->payloads[i];
cfe9f903 2411 bool put_port = false;
706246c7 2412
ad7f8a1f
DA		 2413 /* solve the current payloads - compare to the hw ones
2414 - update the hw view */
2415 req_payload.start_slot = cur_slots;
706246c7
LP		 2416 if (vcpi) {
2417 port = container_of(vcpi, struct drm_dp_mst_port,
2418 vcpi);
cfe9f903
LP		 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;
263efde3 2431 }
cfe9f903 2432
706246c7
LP		 2433 req_payload.num_slots = vcpi->num_slots;
2434 req_payload.vcpi = vcpi->vcpi;
ad7f8a1f
DA		 2435 } else {
2436 port = NULL;
2437 req_payload.num_slots = 0;
2438 }
dfda0df3 2439
706246c7 2440 payload->start_slot = req_payload.start_slot;
ad7f8a1f 2441 /* work out what is required to happen with this payload */
706246c7 2442 if (payload->num_slots != req_payload.num_slots) {
ad7f8a1f
DA		 2443
2444 /* need to push an update for this payload */
2445 if (req_payload.num_slots) {
706246c7
LP		 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;
dfda0df3 2459 }
706246c7 2460 payload->payload_state = req_payload.payload_state;
ad7f8a1f
DA		 2461 }
2462 cur_slots += req_payload.num_slots;
263efde3 2463
cfe9f903 2464 if (put_port)
d0757afd 2465 drm_dp_mst_topology_put_port(port);
ad7f8a1f 2466 }
dfda0df3
DA		 2467
2468 for (i = 0; i < mgr->max_payloads; i++) {
706246c7
LP		 2469 if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL)
2470 continue;
dfda0df3 2471
706246c7
LP		 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 }
dfda0df3 2483 }
706246c7
LP		 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);
dfda0df3 2489 }
ad7f8a1f
DA		 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;
7389ad4b 2509 int ret = 0;
ad7f8a1f
DA		 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) {
dfda0df3 2520 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
ad7f8a1f 2521 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
dfda0df3 2522 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
ad7f8a1f
DA		 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
ad7f8a1f
DA		 2534static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
2535 struct drm_dp_mst_port *port,
562836a2 2536 int offset, int size, u8 *bytes)
ad7f8a1f
DA		 2537{
2538 int len;
562836a2 2539 int ret = 0;
ad7f8a1f 2540 struct drm_dp_sideband_msg_tx *txmsg;
562836a2
VS		 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;
ad7f8a1f
DA		 2546
2547 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
562836a2
VS		 2548 if (!txmsg) {
2549 ret = -ENOMEM;
2550 goto fail_put;
2551 }
ad7f8a1f 2552
562836a2 2553 len = build_dpcd_read(txmsg, port->port_num, offset, size);
ad7f8a1f
DA		 2554 txmsg->dst = port->parent;
2555
2556 drm_dp_queue_down_tx(mgr, txmsg);
2557
562836a2
VS		 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;
ad7f8a1f 2585}
ad7f8a1f
DA		 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
d0757afd 2596 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
ad7f8a1f
DA		 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) {
45bbda1e 2613 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
562836a2 2614 ret = -EIO;
45bbda1e 2615 else
ad7f8a1f
DA		 2616 ret = 0;
2617 }
2618 kfree(txmsg);
2619fail_put:
d0757afd 2620 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 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
45bbda1e 2628 reply.reply_type = DP_SIDEBAND_REPLY_ACK;
ad7f8a1f
DA		 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);
1f16ee7f
ML		 2649
2650 process_single_up_tx_qlock(mgr, txmsg);
2651
ad7f8a1f 2652 mutex_unlock(&mgr->qlock);
1f16ee7f
ML		 2653
2654 kfree(txmsg);
ad7f8a1f
DA		 2655 return 0;
2656}
2657
b853fdb3
CW		 2658static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
2659 int dp_link_count,
2660 int *out)
ad7f8a1f
DA		 2661{
2662 switch (dp_link_bw) {
b853fdb3
CW		 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
ad7f8a1f 2668 case DP_LINK_BW_1_62:
b853fdb3
CW		 2669 *out = 3 * dp_link_count;
2670 break;
ad7f8a1f 2671 case DP_LINK_BW_2_7:
b853fdb3
CW		 2672 *out = 5 * dp_link_count;
2673 break;
ad7f8a1f 2674 case DP_LINK_BW_5_4:
b853fdb3
CW		 2675 *out = 10 * dp_link_count;
2676 break;
e0bd878a
MN		 2677 case DP_LINK_BW_8_1:
2678 *out = 15 * dp_link_count;
2679 break;
ad7f8a1f 2680 }
b853fdb3 2681 return true;
ad7f8a1f
DA		 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
b853fdb3
CW		 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
ad7f8a1f
DA		 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;
ebcc0e6b 2730 drm_dp_mst_topology_get_mstb(mgr->mst_primary);
ad7f8a1f 2731
c175cd16
AG		 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
ad7f8a1f
DA		 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
ad7f8a1f
DA		 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);
dfda0df3 2758 mgr->vcpi_mask = 0;
ad7f8a1f
DA		 2759 }
2760
2761out_unlock:
2762 mutex_unlock(&mgr->lock);
2763 if (mstb)
d0757afd 2764 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 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);
274d8352
DA		 2783 flush_work(&mgr->work);
2784 flush_work(&mgr->destroy_connector_work);
ad7f8a1f
DA		 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;
1652fce6
L		 2806 u8 guid[16];
2807
ad7f8a1f
DA		 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 }
1652fce6
L		 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
ad7f8a1f
DA		 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
636c4c3e 2842static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
ad7f8a1f
DA		 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);
636c4c3e 2857 return false;
ad7f8a1f
DA		 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]);
636c4c3e 2862 return false;
ad7f8a1f
DA		 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) {
448421b5
ID		 2874 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
2875 len, ret);
636c4c3e 2876 return false;
ad7f8a1f 2877 }
448421b5 2878
ad7f8a1f 2879 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
448421b5 2880 if (!ret) {
ad7f8a1f 2881 DRM_DEBUG_KMS("failed to build sideband msg\n");
636c4c3e 2882 return false;
448421b5
ID		 2883 }
2884
ad7f8a1f
DA		 2885 curreply += len;
2886 replylen -= len;
2887 }
636c4c3e 2888 return true;
ad7f8a1f
DA		 2889}
2890
2891static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2892{
2893 int ret = 0;
2894
636c4c3e
ID		 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 }
ad7f8a1f
DA		 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]);
d0757afd 2929 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 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);
45bbda1e
VS		 2935
2936 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3dadbd29
VS		 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);
ad7f8a1f
DA		 2943
2944 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
d0757afd 2945 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 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
68e989dc 2952 wake_up_all(&mgr->tx_waitq);
ad7f8a1f
DA		 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;
636c4c3e
ID		 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 }
ad7f8a1f
DA		 2966
2967 if (mgr->up_req_recv.have_eomt) {
2968 struct drm_dp_sideband_msg_req_body msg;
bd934320 2969 struct drm_dp_mst_branch *mstb = NULL;
ad7f8a1f 2970 bool seqno;
bd934320
ML		 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 }
ad7f8a1f
DA		 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) {
bd934320
ML		 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
ad7f8a1f 2998 drm_dp_update_port(mstb, &msg.u.conn_stat);
5e93b820 2999
ad7f8a1f 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);
16bff572 3001 drm_kms_helper_hotplug_event(mgr->dev);
8ae22cb4 3002
ad7f8a1f 3003 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
bd934320
ML		 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
ad7f8a1f
DA		 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
7f8b3987 3017 if (mstb)
d0757afd 3018 drm_dp_mst_topology_put_mstb(mstb);
7f8b3987 3019
ad7f8a1f
DA		 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
295ee853 3029 * @handled: whether the hpd interrupt was consumed or not
ad7f8a1f
DA		 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
132d49d7 3065 * @connector: DRM connector for this port
ad7f8a1f
DA		 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 */
c6a0aed4
DA		 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)
ad7f8a1f
DA		 3074{
3075 enum drm_connector_status status = connector_status_disconnected;
3076
1e55a53a 3077 /* we need to search for the port in the mgr in case it's gone */
d0757afd 3078 port = drm_dp_mst_topology_get_port_validated(mgr, port);
ad7f8a1f
DA		 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;
8ae22cb4
DA		 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 }
ad7f8a1f
DA		 3096 break;
3097 case DP_PEER_DEVICE_DP_LEGACY_CONV:
3098 if (port->ldps)
3099 status = connector_status_connected;
3100 break;
3101 }
3102out:
d0757afd 3103 drm_dp_mst_topology_put_port(port);
ad7f8a1f
DA		 3104 return status;
3105}
3106EXPORT_SYMBOL(drm_dp_mst_detect_port);
3107
ef8f9bea
LY		 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
d0757afd 3120 port = drm_dp_mst_topology_get_port_validated(mgr, port);
ef8f9bea
LY		 3121 if (!port)
3122 return ret;
3123 ret = port->has_audio;
d0757afd 3124 drm_dp_mst_topology_put_port(port);
ef8f9bea
LY		 3125 return ret;
3126}
3127EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
3128
ad7f8a1f
DA		 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
1e55a53a 3143 /* we need to search for the port in the mgr in case it's gone */
d0757afd 3144 port = drm_dp_mst_topology_get_port_validated(mgr, port);
ad7f8a1f
DA		 3145 if (!port)
3146 return NULL;
3147
c6a0aed4
DA		 3148 if (port->cached_edid)
3149 edid = drm_edid_duplicate(port->cached_edid);
8ae22cb4
DA		 3150 else {
3151 edid = drm_get_edid(connector, &port->aux.ddc);
8ae22cb4 3152 }
ef8f9bea 3153 port->has_audio = drm_detect_monitor_audio(edid);
d0757afd 3154 drm_dp_mst_topology_put_port(port);
ad7f8a1f
DA		 3155 return edid;
3156}
3157EXPORT_SYMBOL(drm_dp_mst_get_edid);
3158
3159/**
e4b0c868 3160 * drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
ad7f8a1f
DA		 3161 * @mgr: manager to use
3162 * @pbn: payload bandwidth to convert into slots.
e4b0c868
LP		 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.
ad7f8a1f
DA		 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
feb2c3bc
PD		 3178 /* max. time slots - one slot for MTP header */
3179 if (num_slots > 63)
ad7f8a1f
DA		 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,
1e797f55 3186 struct drm_dp_vcpi *vcpi, int pbn, int slots)
ad7f8a1f 3187{
ad7f8a1f
DA		 3188 int ret;
3189
feb2c3bc 3190 /* max. time slots - one slot for MTP header */
1e797f55 3191 if (slots > 63)
ad7f8a1f
DA		 3192 return -ENOSPC;
3193
3194 vcpi->pbn = pbn;
1e797f55
PD		 3195 vcpi->aligned_pbn = slots * mgr->pbn_div;
3196 vcpi->num_slots = slots;
ad7f8a1f
DA		 3197
3198 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
3199 if (ret < 0)
3200 return ret;
3201 return 0;
3202}
3203
edb1ed1a 3204/**
eceae147 3205 * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
edb1ed1a
PD		 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 *
eceae147
LP		 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
edb1ed1a
PD		 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;
eceae147
LP		 3239 struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
3240 int prev_slots, req_slots, ret;
edb1ed1a
PD		 3241
3242 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
56a91c49
VS		 3243 if (IS_ERR(topology_state))
3244 return PTR_ERR(topology_state);
edb1ed1a 3245
eceae147
LP		 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 }
edb1ed1a 3265 }
eceae147
LP		 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);
a3d15c4b
LP		 3278 if (!vcpi)
3279 return -ENOMEM;
edb1ed1a 3280
eceae147
LP		 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;
edb1ed1a 3286
eceae147 3287 ret = req_slots;
eceae147 3288 return ret;
edb1ed1a
PD		 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
eceae147 3296 * @port: The port to release the VCPI slots from
edb1ed1a 3297 *
eceae147
LP		 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
1e55a53a 3301 * connector will no longer have VCPI allocated (e.g. because its CRTC was
eceae147
LP		 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
edb1ed1a
PD		 3317 */
3318int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
3319 struct drm_dp_mst_topology_mgr *mgr,
eceae147 3320 struct drm_dp_mst_port *port)
edb1ed1a
PD		 3321{
3322 struct drm_dp_mst_topology_state *topology_state;
eceae147
LP		 3323 struct drm_dp_vcpi_allocation *pos;
3324 bool found = false;
edb1ed1a
PD		 3325
3326 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
56a91c49
VS		 3327 if (IS_ERR(topology_state))
3328 return PTR_ERR(topology_state);
edb1ed1a 3329
eceae147
LP		 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 }
edb1ed1a
PD		 3347
3348 return 0;
3349}
3350EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
3351
ad7f8a1f
DA		 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 */
1e797f55
PD		 3359bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
3360 struct drm_dp_mst_port *port, int pbn, int slots)
ad7f8a1f
DA		 3361{
3362 int ret;
3363
d0757afd 3364 port = drm_dp_mst_topology_get_port_validated(mgr, port);
ad7f8a1f
DA		 3365 if (!port)
3366 return false;
3367
1e797f55
PD		 3368 if (slots < 0)
3369 return false;
3370
ad7f8a1f 3371 if (port->vcpi.vcpi > 0) {
e0ac7113
LP		 3372 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
3373 port->vcpi.vcpi, port->vcpi.pbn, pbn);
ad7f8a1f 3374 if (pbn == port->vcpi.pbn) {
d0757afd 3375 drm_dp_mst_topology_put_port(port);
ad7f8a1f
DA		 3376 return true;
3377 }
3378 }
3379
1e797f55 3380 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
ad7f8a1f 3381 if (ret) {
feb2c3bc 3382 DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
e0ac7113 3383 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
ad7f8a1f
DA		 3384 goto out;
3385 }
feb2c3bc 3386 DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
e0ac7113 3387 pbn, port->vcpi.num_slots);
ad7f8a1f 3388
1e55a53a 3389 /* Keep port allocated until its payload has been removed */
cfe9f903 3390 drm_dp_mst_get_port_malloc(port);
d0757afd 3391 drm_dp_mst_topology_put_port(port);
ad7f8a1f
DA		 3392 return true;
3393out:
3394 return false;
3395}
3396EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
3397
87f5942d
DA		 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;
d0757afd 3401 port = drm_dp_mst_topology_get_port_validated(mgr, port);
87f5942d
DA		 3402 if (!port)
3403 return slots;
3404
3405 slots = port->vcpi.num_slots;
d0757afd 3406 drm_dp_mst_topology_put_port(port);
87f5942d
DA		 3407 return slots;
3408}
3409EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
3410
ad7f8a1f
DA		 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{
cfe9f903 3420 /*
1e55a53a 3421 * A port with VCPI will remain allocated until its VCPI is
cfe9f903
LP		 3422 * released, no verified ref needed
3423 */
3424
ad7f8a1f 3425 port->vcpi.num_slots = 0;
ad7f8a1f
DA		 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
3a8844c2
LP		 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.
ad7f8a1f 3436 */
4afb8a26
LP		 3437void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
3438 struct drm_dp_mst_port *port)
ad7f8a1f 3439{
3a8844c2
LP		 3440 if (!port->vcpi.vcpi)
3441 return;
ad7f8a1f
DA		 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;
cfe9f903 3448 drm_dp_mst_put_port_malloc(port);
ad7f8a1f
DA		 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{
a9ebb3e4
HW		 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);
ad7f8a1f
DA		 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);
a9ebb3e4
HW		 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);
ad7f8a1f 3577 return -EINVAL;
a9ebb3e4 3578 }
ad7f8a1f 3579 ret = drm_dp_calc_pbn_mode(234000, 30);
a9ebb3e4
HW		 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);
ad7f8a1f 3583 return -EINVAL;
a9ebb3e4
HW		 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 }
ad7f8a1f
DA		 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) {
51108f25 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);
ad7f8a1f
DA		 3615 if (port->mstb)
3616 drm_dp_mst_dump_mstb(m, port->mstb);
3617 }
3618}
3619
7056a2bc
AS		 3620#define DP_PAYLOAD_TABLE_SIZE 64
3621
ad7f8a1f
DA		 3622static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
3623 char *buf)
3624{
ad7f8a1f 3625 int i;
46466b0d 3626
7056a2bc 3627 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
46466b0d
JP		 3628 if (drm_dp_dpcd_read(mgr->aux,
3629 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
3630 &buf[i], 16) != 16)
3631 return false;
ad7f8a1f 3632 }
46466b0d 3633 return true;
ad7f8a1f
DA		 3634}
3635
51108f25
JB		 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
ad7f8a1f
DA		 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;
51108f25 3658
ad7f8a1f
DA		 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);
51108f25
JB		 3667 seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
3668 mgr->max_payloads);
ad7f8a1f
DA		 3669
3670 for (i = 0; i < mgr->max_payloads; i++) {
3671 if (mgr->proposed_vcpis[i]) {
51108f25
JB		 3672 char name[14];
3673
ad7f8a1f 3674 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
51108f25
JB		 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");
ad7f8a1f 3680 } else
51108f25 3681 seq_printf(m, "vcpi %d:unused\n", i);
ad7f8a1f
DA		 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) {
7056a2bc 3696 u8 buf[DP_PAYLOAD_TABLE_SIZE];
ad7f8a1f 3697 int ret;
46466b0d 3698
ad7f8a1f 3699 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
46466b0d 3700 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
ad7f8a1f 3701 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
46466b0d 3702 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
ad7f8a1f 3703 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
46466b0d 3704 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
ad7f8a1f 3705
44790462
DA		 3706 /* dump the standard OUI branch header */
3707 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
46466b0d 3708 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
51108f25 3709 for (i = 0x3; i < 0x8 && buf[i]; i++)
44790462 3710 seq_printf(m, "%c", buf[i]);
46466b0d
JP		 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))
7056a2bc 3714 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
ad7f8a1f
DA		 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);
cb021a3e 3727 if (!list_empty(&mgr->tx_msg_downq))
ad7f8a1f
DA		 3728 process_single_down_tx_qlock(mgr);
3729 mutex_unlock(&mgr->qlock);
3730}
3731
6b8eeca6
DA		 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);
4772ff03 3735 struct drm_dp_mst_port *port;
df4839fd 3736 bool send_hotplug = false;
6b8eeca6
DA		 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);
4772ff03
ML		 3744 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
3745 if (!port) {
6b8eeca6
DA		 3746 mutex_unlock(&mgr->destroy_connector_lock);
3747 break;
3748 }
4772ff03 3749 list_del(&port->next);
6b8eeca6
DA		 3750 mutex_unlock(&mgr->destroy_connector_lock);
3751
91a25e46
ML		 3752 INIT_LIST_HEAD(&port->next);
3753
4772ff03
ML		 3754 mgr->cbs->destroy_connector(mgr, port->connector);
3755
3756 drm_dp_port_teardown_pdt(port, port->pdt);
36e3fa6a 3757 port->pdt = DP_PEER_DEVICE_NONE;
4772ff03 3758
ebcc0e6b 3759 drm_dp_mst_put_port_malloc(port);
df4839fd 3760 send_hotplug = true;
6b8eeca6 3761 }
df4839fd 3762 if (send_hotplug)
16bff572 3763 drm_kms_helper_hotplug_event(mgr->dev);
6b8eeca6
DA		 3764}
3765
a4370c77
VS		 3766static struct drm_private_state *
3767drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
3f3353b7 3768{
eceae147
LP		 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;
3f3353b7 3772
eceae147 3773 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
a4370c77 3774 if (!state)
3f3353b7
PD		 3775 return NULL;
3776
a4370c77 3777 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
3f3353b7 3778
eceae147
LP		 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
a4370c77 3794 return &state->base;
eceae147
LP		 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;
3f3353b7
PD		 3804}
3805
a4370c77
VS		 3806static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
3807 struct drm_private_state *state)
3f3353b7 3808{
a4370c77
VS		 3809 struct drm_dp_mst_topology_state *mst_state =
3810 to_dp_mst_topology_state(state);
eceae147
LP		 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 }
a4370c77
VS		 3819
3820 kfree(mst_state);
3f3353b7
PD		 3821}
3822
eceae147
LP		 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;
5e187a01 3828 int avail_slots = 63, payload_count = 0;
eceae147
LP		 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 }
5e187a01
LP		 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 }
eceae147
LP		 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
bea5c38f 3899const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
a4370c77
VS		 3900 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
3901 .atomic_destroy_state = drm_dp_mst_destroy_state,
3f3353b7 3902};
bea5c38f 3903EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
3f3353b7
PD		 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));
a4370c77 3926 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
3f3353b7
PD		 3927}
3928EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
3929
ad7f8a1f
DA		 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,
7b0a89a6 3942 struct drm_device *dev, struct drm_dp_aux *aux,
ad7f8a1f
DA		 3943 int max_dpcd_transaction_bytes,
3944 int max_payloads, int conn_base_id)
3945{
a4370c77
VS		 3946 struct drm_dp_mst_topology_state *mst_state;
3947
ad7f8a1f
DA		 3948 mutex_init(&mgr->lock);
3949 mutex_init(&mgr->qlock);
3950 mutex_init(&mgr->payload_lock);
6b8eeca6 3951 mutex_init(&mgr->destroy_connector_lock);
ad7f8a1f 3952 INIT_LIST_HEAD(&mgr->tx_msg_downq);
6b8eeca6 3953 INIT_LIST_HEAD(&mgr->destroy_connector_list);
ad7f8a1f
DA		 3954 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
3955 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
6b8eeca6 3956 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
ad7f8a1f
DA		 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;
4d6a10da
ID		 3963 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
3964 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
3965 return -EINVAL;
ad7f8a1f
DA		 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);
441388a8
ID		 3973 if (test_calc_pbn_mode() < 0)
3974 DRM_ERROR("MST PBN self-test failed\n");
3975
a4370c77
VS		 3976 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
3977 if (mst_state == NULL)
3f3353b7 3978 return -ENOMEM;
a4370c77
VS		 3979
3980 mst_state->mgr = mgr;
eceae147 3981 INIT_LIST_HEAD(&mst_state->vcpis);
a4370c77 3982
b962a120 3983 drm_atomic_private_obj_init(dev, &mgr->base,
a4370c77 3984 &mst_state->base,
bea5c38f 3985 &drm_dp_mst_topology_state_funcs);
3f3353b7 3986
ad7f8a1f
DA		 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{
f536e00c 3997 drm_dp_mst_topology_mgr_set_mst(mgr, false);
274d8352 3998 flush_work(&mgr->work);
6b8eeca6 3999 flush_work(&mgr->destroy_connector_work);
ad7f8a1f
DA		 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;
a4370c77 4008 drm_atomic_private_obj_fini(&mgr->base);
3f3353b7 4009 mgr->funcs = NULL;
ad7f8a1f
DA		 4010}
4011EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
4012
cb8ce711
VS		 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
ad7f8a1f
DA		 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;
ad7f8a1f
DA		 4039 struct drm_dp_sideband_msg_req_body msg;
4040 struct drm_dp_sideband_msg_tx *txmsg = NULL;
4041 int ret;
4042
d0757afd 4043 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
ad7f8a1f
DA		 4044 if (!mstb)
4045 return -EREMOTEIO;
4046
cb8ce711 4047 if (!remote_i2c_read_ok(msgs, num)) {
ad7f8a1f
DA		 4048 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
4049 ret = -EIO;
4050 goto out;
4051 }
4052
ae491542 4053 memset(&msg, 0, sizeof(msg));
ad7f8a1f
DA		 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;
c978ae9b 4061 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
ad7f8a1f
DA		 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
45bbda1e 4080 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
ad7f8a1f
DA		 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);
d0757afd 4093 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 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}
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