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drm: Split out drm_probe_helper.h
[linux-block.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
23#include <linux/kernel.h>
24#include <linux/delay.h>
25#include <linux/init.h>
26#include <linux/errno.h>
27#include <linux/sched.h>
75bc08ab 28#include <linux/seq_file.h>
ad7f8a1f
DA		 29#include <linux/i2c.h>
30#include <drm/drm_dp_mst_helper.h>
31#include <drm/drmP.h>
32
33#include <drm/drm_fixed.h>
a4370c77
VS		 34#include <drm/drm_atomic.h>
35#include <drm/drm_atomic_helper.h>
fcd70cd3 36#include <drm/drm_probe_helper.h>
ad7f8a1f
DA		 37
38/**
39 * DOC: dp mst helper
40 *
41 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
42 * protocol. The helpers contain a topology manager and bandwidth manager.
43 * The helpers encapsulate the sending and received of sideband msgs.
44 */
45static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
46 char *buf);
47static int test_calc_pbn_mode(void);
48
d0757afd 49static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
ad7f8a1f
DA		 50
51static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
52 int id,
53 struct drm_dp_payload *payload);
54
55static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
56 struct drm_dp_mst_port *port,
57 int offset, int size, u8 *bytes);
58
68d8c9fc
DA		 59static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
60 struct drm_dp_mst_branch *mstb);
ad7f8a1f
DA		 61static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
62 struct drm_dp_mst_branch *mstb,
63 struct drm_dp_mst_port *port);
64static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
65 u8 *guid);
66
67static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
68static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
69static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
70/* sideband msg handling */
71static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
72{
73 u8 bitmask = 0x80;
74 u8 bitshift = 7;
75 u8 array_index = 0;
76 int number_of_bits = num_nibbles * 4;
77 u8 remainder = 0;
78
79 while (number_of_bits != 0) {
80 number_of_bits--;
81 remainder <<= 1;
82 remainder |= (data[array_index] & bitmask) >> bitshift;
83 bitmask >>= 1;
84 bitshift--;
85 if (bitmask == 0) {
86 bitmask = 0x80;
87 bitshift = 7;
88 array_index++;
89 }
90 if ((remainder & 0x10) == 0x10)
91 remainder ^= 0x13;
92 }
93
94 number_of_bits = 4;
95 while (number_of_bits != 0) {
96 number_of_bits--;
97 remainder <<= 1;
98 if ((remainder & 0x10) != 0)
99 remainder ^= 0x13;
100 }
101
102 return remainder;
103}
104
105static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
106{
107 u8 bitmask = 0x80;
108 u8 bitshift = 7;
109 u8 array_index = 0;
110 int number_of_bits = number_of_bytes * 8;
111 u16 remainder = 0;
112
113 while (number_of_bits != 0) {
114 number_of_bits--;
115 remainder <<= 1;
116 remainder |= (data[array_index] & bitmask) >> bitshift;
117 bitmask >>= 1;
118 bitshift--;
119 if (bitmask == 0) {
120 bitmask = 0x80;
121 bitshift = 7;
122 array_index++;
123 }
124 if ((remainder & 0x100) == 0x100)
125 remainder ^= 0xd5;
126 }
127
128 number_of_bits = 8;
129 while (number_of_bits != 0) {
130 number_of_bits--;
131 remainder <<= 1;
132 if ((remainder & 0x100) != 0)
133 remainder ^= 0xd5;
134 }
135
136 return remainder & 0xff;
137}
138static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
139{
140 u8 size = 3;
141 size += (hdr->lct / 2);
142 return size;
143}
144
145static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
146 u8 *buf, int *len)
147{
148 int idx = 0;
149 int i;
150 u8 crc4;
151 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
152 for (i = 0; i < (hdr->lct / 2); i++)
153 buf[idx++] = hdr->rad[i];
154 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
155 (hdr->msg_len & 0x3f);
156 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
157
158 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
159 buf[idx - 1] |= (crc4 & 0xf);
160
161 *len = idx;
162}
163
164static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
165 u8 *buf, int buflen, u8 *hdrlen)
166{
167 u8 crc4;
168 u8 len;
169 int i;
170 u8 idx;
171 if (buf[0] == 0)
172 return false;
173 len = 3;
174 len += ((buf[0] & 0xf0) >> 4) / 2;
175 if (len > buflen)
176 return false;
177 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
178
179 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
180 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
181 return false;
182 }
183
184 hdr->lct = (buf[0] & 0xf0) >> 4;
185 hdr->lcr = (buf[0] & 0xf);
186 idx = 1;
187 for (i = 0; i < (hdr->lct / 2); i++)
188 hdr->rad[i] = buf[idx++];
189 hdr->broadcast = (buf[idx] >> 7) & 0x1;
190 hdr->path_msg = (buf[idx] >> 6) & 0x1;
191 hdr->msg_len = buf[idx] & 0x3f;
192 idx++;
193 hdr->somt = (buf[idx] >> 7) & 0x1;
194 hdr->eomt = (buf[idx] >> 6) & 0x1;
195 hdr->seqno = (buf[idx] >> 4) & 0x1;
196 idx++;
197 *hdrlen = idx;
198 return true;
199}
200
201static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
202 struct drm_dp_sideband_msg_tx *raw)
203{
204 int idx = 0;
205 int i;
206 u8 *buf = raw->msg;
207 buf[idx++] = req->req_type & 0x7f;
208
209 switch (req->req_type) {
210 case DP_ENUM_PATH_RESOURCES:
211 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
212 idx++;
213 break;
214 case DP_ALLOCATE_PAYLOAD:
215 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
216 (req->u.allocate_payload.number_sdp_streams & 0xf);
217 idx++;
218 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
219 idx++;
220 buf[idx] = (req->u.allocate_payload.pbn >> 8);
221 idx++;
222 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
223 idx++;
224 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
225 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
226 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
227 idx++;
228 }
229 if (req->u.allocate_payload.number_sdp_streams & 1) {
230 i = req->u.allocate_payload.number_sdp_streams - 1;
231 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
232 idx++;
233 }
234 break;
235 case DP_QUERY_PAYLOAD:
236 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
237 idx++;
238 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
239 idx++;
240 break;
241 case DP_REMOTE_DPCD_READ:
242 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
243 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
244 idx++;
245 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
246 idx++;
247 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
248 idx++;
249 buf[idx] = (req->u.dpcd_read.num_bytes);
250 idx++;
251 break;
252
253 case DP_REMOTE_DPCD_WRITE:
254 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
255 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
256 idx++;
257 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
258 idx++;
259 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
260 idx++;
261 buf[idx] = (req->u.dpcd_write.num_bytes);
262 idx++;
263 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
264 idx += req->u.dpcd_write.num_bytes;
265 break;
266 case DP_REMOTE_I2C_READ:
267 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
268 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
269 idx++;
270 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
271 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
272 idx++;
273 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
274 idx++;
275 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
276 idx += req->u.i2c_read.transactions[i].num_bytes;
277
278 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
279 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
280 idx++;
281 }
282 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
283 idx++;
284 buf[idx] = (req->u.i2c_read.num_bytes_read);
285 idx++;
286 break;
287
288 case DP_REMOTE_I2C_WRITE:
289 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
290 idx++;
291 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
292 idx++;
293 buf[idx] = (req->u.i2c_write.num_bytes);
294 idx++;
295 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
296 idx += req->u.i2c_write.num_bytes;
297 break;
0bb9c2b2
DP		 298
299 case DP_POWER_DOWN_PHY:
300 case DP_POWER_UP_PHY:
301 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
302 idx++;
303 break;
ad7f8a1f
DA		 304 }
305 raw->cur_len = idx;
306}
307
308static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
309{
310 u8 crc4;
311 crc4 = drm_dp_msg_data_crc4(msg, len);
312 msg[len] = crc4;
313}
314
315static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
316 struct drm_dp_sideband_msg_tx *raw)
317{
318 int idx = 0;
319 u8 *buf = raw->msg;
320
321 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
322
323 raw->cur_len = idx;
324}
325
326/* this adds a chunk of msg to the builder to get the final msg */
327static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
328 u8 *replybuf, u8 replybuflen, bool hdr)
329{
330 int ret;
331 u8 crc4;
332
333 if (hdr) {
334 u8 hdrlen;
335 struct drm_dp_sideband_msg_hdr recv_hdr;
336 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
337 if (ret == false) {
338 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
339 return false;
340 }
341
636c4c3e
ID		 342 /*
343 * ignore out-of-order messages or messages that are part of a
344 * failed transaction
345 */
346 if (!recv_hdr.somt && !msg->have_somt)
347 return false;
348
ad7f8a1f
DA		 349 /* get length contained in this portion */
350 msg->curchunk_len = recv_hdr.msg_len;
351 msg->curchunk_hdrlen = hdrlen;
352
353 /* we have already gotten an somt - don't bother parsing */
354 if (recv_hdr.somt && msg->have_somt)
355 return false;
356
357 if (recv_hdr.somt) {
358 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
359 msg->have_somt = true;
360 }
361 if (recv_hdr.eomt)
362 msg->have_eomt = true;
363
364 /* copy the bytes for the remainder of this header chunk */
365 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
366 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
367 } else {
368 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
369 msg->curchunk_idx += replybuflen;
370 }
371
372 if (msg->curchunk_idx >= msg->curchunk_len) {
373 /* do CRC */
374 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
375 /* copy chunk into bigger msg */
376 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
377 msg->curlen += msg->curchunk_len - 1;
378 }
379 return true;
380}
381
382static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
383 struct drm_dp_sideband_msg_reply_body *repmsg)
384{
385 int idx = 1;
386 int i;
387 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
388 idx += 16;
389 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
390 idx++;
391 if (idx > raw->curlen)
392 goto fail_len;
393 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
394 if (raw->msg[idx] & 0x80)
395 repmsg->u.link_addr.ports[i].input_port = 1;
396
397 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
398 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
399
400 idx++;
401 if (idx > raw->curlen)
402 goto fail_len;
403 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
404 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
405 if (repmsg->u.link_addr.ports[i].input_port == 0)
406 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
407 idx++;
408 if (idx > raw->curlen)
409 goto fail_len;
410 if (repmsg->u.link_addr.ports[i].input_port == 0) {
411 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
412 idx++;
413 if (idx > raw->curlen)
414 goto fail_len;
415 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
416 idx += 16;
417 if (idx > raw->curlen)
418 goto fail_len;
419 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
420 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
421 idx++;
422
423 }
424 if (idx > raw->curlen)
425 goto fail_len;
426 }
427
428 return true;
429fail_len:
430 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
431 return false;
432}
433
434static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
435 struct drm_dp_sideband_msg_reply_body *repmsg)
436{
437 int idx = 1;
438 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
439 idx++;
440 if (idx > raw->curlen)
441 goto fail_len;
442 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
a4c30a48 443 idx++;
ad7f8a1f
DA		 444 if (idx > raw->curlen)
445 goto fail_len;
446
447 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
448 return true;
449fail_len:
450 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
451 return false;
452}
453
454static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
455 struct drm_dp_sideband_msg_reply_body *repmsg)
456{
457 int idx = 1;
458 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
459 idx++;
460 if (idx > raw->curlen)
461 goto fail_len;
462 return true;
463fail_len:
464 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
465 return false;
466}
467
468static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
469 struct drm_dp_sideband_msg_reply_body *repmsg)
470{
471 int idx = 1;
472
473 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
474 idx++;
475 if (idx > raw->curlen)
476 goto fail_len;
477 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
478 idx++;
479 /* TODO check */
480 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
481 return true;
482fail_len:
483 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
484 return false;
485}
486
487static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
488 struct drm_dp_sideband_msg_reply_body *repmsg)
489{
490 int idx = 1;
491 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
492 idx++;
493 if (idx > raw->curlen)
494 goto fail_len;
495 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
496 idx += 2;
497 if (idx > raw->curlen)
498 goto fail_len;
499 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
500 idx += 2;
501 if (idx > raw->curlen)
502 goto fail_len;
503 return true;
504fail_len:
505 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
506 return false;
507}
508
509static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
510 struct drm_dp_sideband_msg_reply_body *repmsg)
511{
512 int idx = 1;
513 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
514 idx++;
515 if (idx > raw->curlen)
516 goto fail_len;
517 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
518 idx++;
519 if (idx > raw->curlen)
520 goto fail_len;
521 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
522 idx += 2;
523 if (idx > raw->curlen)
524 goto fail_len;
525 return true;
526fail_len:
527 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
528 return false;
529}
530
531static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
532 struct drm_dp_sideband_msg_reply_body *repmsg)
533{
534 int idx = 1;
535 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
536 idx++;
537 if (idx > raw->curlen)
538 goto fail_len;
539 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
540 idx += 2;
541 if (idx > raw->curlen)
542 goto fail_len;
543 return true;
544fail_len:
545 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
546 return false;
547}
548
0bb9c2b2
DP		 549static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
550 struct drm_dp_sideband_msg_reply_body *repmsg)
551{
552 int idx = 1;
553
554 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
555 idx++;
556 if (idx > raw->curlen) {
557 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
558 idx, raw->curlen);
559 return false;
560 }
561 return true;
562}
563
ad7f8a1f
DA		 564static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
565 struct drm_dp_sideband_msg_reply_body *msg)
566{
567 memset(msg, 0, sizeof(*msg));
568 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
569 msg->req_type = (raw->msg[0] & 0x7f);
570
571 if (msg->reply_type) {
572 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
573 msg->u.nak.reason = raw->msg[17];
574 msg->u.nak.nak_data = raw->msg[18];
575 return false;
576 }
577
578 switch (msg->req_type) {
579 case DP_LINK_ADDRESS:
580 return drm_dp_sideband_parse_link_address(raw, msg);
581 case DP_QUERY_PAYLOAD:
582 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
583 case DP_REMOTE_DPCD_READ:
584 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
585 case DP_REMOTE_DPCD_WRITE:
586 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
587 case DP_REMOTE_I2C_READ:
588 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
589 case DP_ENUM_PATH_RESOURCES:
590 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
591 case DP_ALLOCATE_PAYLOAD:
592 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
0bb9c2b2
DP		 593 case DP_POWER_DOWN_PHY:
594 case DP_POWER_UP_PHY:
595 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
ad7f8a1f
DA		 596 default:
597 DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
598 return false;
599 }
600}
601
602static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
603 struct drm_dp_sideband_msg_req_body *msg)
604{
605 int idx = 1;
606
607 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
608 idx++;
609 if (idx > raw->curlen)
610 goto fail_len;
611
612 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
613 idx += 16;
614 if (idx > raw->curlen)
615 goto fail_len;
616
617 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
618 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
619 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
620 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
621 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
622 idx++;
623 return true;
624fail_len:
625 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
626 return false;
627}
628
629static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
630 struct drm_dp_sideband_msg_req_body *msg)
631{
632 int idx = 1;
633
634 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
635 idx++;
636 if (idx > raw->curlen)
637 goto fail_len;
638
639 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
640 idx += 16;
641 if (idx > raw->curlen)
642 goto fail_len;
643
644 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
645 idx++;
646 return true;
647fail_len:
648 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
649 return false;
650}
651
652static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
653 struct drm_dp_sideband_msg_req_body *msg)
654{
655 memset(msg, 0, sizeof(*msg));
656 msg->req_type = (raw->msg[0] & 0x7f);
657
658 switch (msg->req_type) {
659 case DP_CONNECTION_STATUS_NOTIFY:
660 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
661 case DP_RESOURCE_STATUS_NOTIFY:
662 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
663 default:
664 DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
665 return false;
666 }
667}
668
669static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
670{
671 struct drm_dp_sideband_msg_req_body req;
672
673 req.req_type = DP_REMOTE_DPCD_WRITE;
674 req.u.dpcd_write.port_number = port_num;
675 req.u.dpcd_write.dpcd_address = offset;
676 req.u.dpcd_write.num_bytes = num_bytes;
677 req.u.dpcd_write.bytes = bytes;
678 drm_dp_encode_sideband_req(&req, msg);
679
680 return 0;
681}
682
683static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
684{
685 struct drm_dp_sideband_msg_req_body req;
686
687 req.req_type = DP_LINK_ADDRESS;
688 drm_dp_encode_sideband_req(&req, msg);
689 return 0;
690}
691
692static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
693{
694 struct drm_dp_sideband_msg_req_body req;
695
696 req.req_type = DP_ENUM_PATH_RESOURCES;
697 req.u.port_num.port_number = port_num;
698 drm_dp_encode_sideband_req(&req, msg);
699 msg->path_msg = true;
700 return 0;
701}
702
703static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
ef8f9bea
LY		 704 u8 vcpi, uint16_t pbn,
705 u8 number_sdp_streams,
706 u8 *sdp_stream_sink)
ad7f8a1f
DA		 707{
708 struct drm_dp_sideband_msg_req_body req;
709 memset(&req, 0, sizeof(req));
710 req.req_type = DP_ALLOCATE_PAYLOAD;
711 req.u.allocate_payload.port_number = port_num;
712 req.u.allocate_payload.vcpi = vcpi;
713 req.u.allocate_payload.pbn = pbn;
ef8f9bea
LY		 714 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
715 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
716 number_sdp_streams);
ad7f8a1f
DA		 717 drm_dp_encode_sideband_req(&req, msg);
718 msg->path_msg = true;
719 return 0;
720}
721
0bb9c2b2
DP		 722static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
723 int port_num, bool power_up)
724{
725 struct drm_dp_sideband_msg_req_body req;
726
727 if (power_up)
728 req.req_type = DP_POWER_UP_PHY;
729 else
730 req.req_type = DP_POWER_DOWN_PHY;
731
732 req.u.port_num.port_number = port_num;
733 drm_dp_encode_sideband_req(&req, msg);
734 msg->path_msg = true;
735 return 0;
736}
737
ad7f8a1f
DA		 738static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
739 struct drm_dp_vcpi *vcpi)
740{
dfda0df3 741 int ret, vcpi_ret;
ad7f8a1f
DA		 742
743 mutex_lock(&mgr->payload_lock);
744 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
745 if (ret > mgr->max_payloads) {
746 ret = -EINVAL;
747 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
748 goto out_unlock;
749 }
750
dfda0df3
DA		 751 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
752 if (vcpi_ret > mgr->max_payloads) {
753 ret = -EINVAL;
754 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
755 goto out_unlock;
756 }
757
ad7f8a1f 758 set_bit(ret, &mgr->payload_mask);
dfda0df3
DA		 759 set_bit(vcpi_ret, &mgr->vcpi_mask);
760 vcpi->vcpi = vcpi_ret + 1;
ad7f8a1f
DA		 761 mgr->proposed_vcpis[ret - 1] = vcpi;
762out_unlock:
763 mutex_unlock(&mgr->payload_lock);
764 return ret;
765}
766
767static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
dfda0df3 768 int vcpi)
ad7f8a1f 769{
dfda0df3
DA		 770 int i;
771 if (vcpi == 0)
ad7f8a1f
DA		 772 return;
773
774 mutex_lock(&mgr->payload_lock);
dfda0df3
DA		 775 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
776 clear_bit(vcpi - 1, &mgr->vcpi_mask);
777
778 for (i = 0; i < mgr->max_payloads; i++) {
779 if (mgr->proposed_vcpis[i])
780 if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
781 mgr->proposed_vcpis[i] = NULL;
782 clear_bit(i + 1, &mgr->payload_mask);
783 }
784 }
ad7f8a1f
DA		 785 mutex_unlock(&mgr->payload_lock);
786}
787
788static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
789 struct drm_dp_sideband_msg_tx *txmsg)
790{
992d38cc 791 unsigned int state;
cd961bb9
DV		 792
793 /*
794 * All updates to txmsg->state are protected by mgr->qlock, and the two
795 * cases we check here are terminal states. For those the barriers
796 * provided by the wake_up/wait_event pair are enough.
797 */
992d38cc
CW		 798 state = READ_ONCE(txmsg->state);
799 return (state == DRM_DP_SIDEBAND_TX_RX ||
800 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
ad7f8a1f
DA		 801}
802
803static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
804 struct drm_dp_sideband_msg_tx *txmsg)
805{
806 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
807 int ret;
808
809 ret = wait_event_timeout(mgr->tx_waitq,
810 check_txmsg_state(mgr, txmsg),
811 (4 * HZ));
812 mutex_lock(&mstb->mgr->qlock);
813 if (ret > 0) {
814 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
815 ret = -EIO;
816 goto out;
817 }
818 } else {
819 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
820
821 /* dump some state */
822 ret = -EIO;
823
824 /* remove from q */
825 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
826 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
827 list_del(&txmsg->next);
828 }
829
830 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
831 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
832 mstb->tx_slots[txmsg->seqno] = NULL;
833 }
834 }
835out:
836 mutex_unlock(&mgr->qlock);
837
838 return ret;
839}
840
841static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
842{
843 struct drm_dp_mst_branch *mstb;
844
845 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
846 if (!mstb)
847 return NULL;
848
849 mstb->lct = lct;
850 if (lct > 1)
851 memcpy(mstb->rad, rad, lct / 2);
852 INIT_LIST_HEAD(&mstb->ports);
ebcc0e6b
LP		 853 kref_init(&mstb->topology_kref);
854 kref_init(&mstb->malloc_kref);
ad7f8a1f
DA		 855 return mstb;
856}
857
91a25e46
ML		 858static void drm_dp_free_mst_branch_device(struct kref *kref)
859{
ebcc0e6b
LP		 860 struct drm_dp_mst_branch *mstb =
861 container_of(kref, struct drm_dp_mst_branch, malloc_kref);
862
863 if (mstb->port_parent)
864 drm_dp_mst_put_port_malloc(mstb->port_parent);
865
91a25e46
ML		 866 kfree(mstb);
867}
868
ebcc0e6b
LP		 869/**
870 * DOC: Branch device and port refcounting
871 *
872 * Topology refcount overview
873 * ~~~~~~~~~~~~~~~~~~~~~~~~~~
874 *
875 * The refcounting schemes for &struct drm_dp_mst_branch and &struct
876 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
877 * two different kinds of refcounts: topology refcounts, and malloc refcounts.
878 *
879 * Topology refcounts are not exposed to drivers, and are handled internally
880 * by the DP MST helpers. The helpers use them in order to prevent the
881 * in-memory topology state from being changed in the middle of critical
882 * operations like changing the internal state of payload allocations. This
883 * means each branch and port will be considered to be connected to the rest
884 * of the topology until it's topology refcount reaches zero. Additionally,
885 * for ports this means that their associated &struct drm_connector will stay
886 * registered with userspace until the port's refcount reaches 0.
887 *
888 * Malloc refcount overview
889 * ~~~~~~~~~~~~~~~~~~~~~~~~
890 *
891 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct
892 * drm_dp_mst_branch allocated even after all of its topology references have
893 * been dropped, so that the driver or MST helpers can safely access each
894 * branch's last known state before it was disconnected from the topology.
895 * When the malloc refcount of a port or branch reaches 0, the memory
896 * allocation containing the &struct drm_dp_mst_branch or &struct
897 * drm_dp_mst_port respectively will be freed.
898 *
899 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
900 * to drivers. As of writing this documentation, there are no drivers that
901 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
902 * helpers. Exposing this API to drivers in a race-free manner would take more
903 * tweaking of the refcounting scheme, however patches are welcome provided
904 * there is a legitimate driver usecase for this.
905 *
906 * Refcount relationships in a topology
907 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
908 *
909 * Let's take a look at why the relationship between topology and malloc
910 * refcounts is designed the way it is.
911 *
912 * .. kernel-figure:: dp-mst/topology-figure-1.dot
913 *
914 * An example of topology and malloc refs in a DP MST topology with two
915 * active payloads. Topology refcount increments are indicated by solid
916 * lines, and malloc refcount increments are indicated by dashed lines.
917 * Each starts from the branch which incremented the refcount, and ends at
918 * the branch to which the refcount belongs to, i.e. the arrow points the
919 * same way as the C pointers used to reference a structure.
920 *
921 * As you can see in the above figure, every branch increments the topology
922 * refcount of it's children, and increments the malloc refcount of it's
923 * parent. Additionally, every payload increments the malloc refcount of it's
924 * assigned port by 1.
925 *
926 * So, what would happen if MSTB #3 from the above figure was unplugged from
927 * the system, but the driver hadn't yet removed payload #2 from port #3? The
928 * topology would start to look like the figure below.
929 *
930 * .. kernel-figure:: dp-mst/topology-figure-2.dot
931 *
932 * Ports and branch devices which have been released from memory are
933 * colored grey, and references which have been removed are colored red.
934 *
935 * Whenever a port or branch device's topology refcount reaches zero, it will
936 * decrement the topology refcounts of all its children, the malloc refcount
937 * of its parent, and finally its own malloc refcount. For MSTB #4 and port
938 * #4, this means they both have been disconnected from the topology and freed
939 * from memory. But, because payload #2 is still holding a reference to port
940 * #3, port #3 is removed from the topology but it's &struct drm_dp_mst_port
941 * is still accessible from memory. This also means port #3 has not yet
942 * decremented the malloc refcount of MSTB #3, so it's &struct
943 * drm_dp_mst_branch will also stay allocated in memory until port #3's
944 * malloc refcount reaches 0.
945 *
946 * This relationship is necessary because in order to release payload #2, we
947 * need to be able to figure out the last relative of port #3 that's still
948 * connected to the topology. In this case, we would travel up the topology as
949 * shown below.
950 *
951 * .. kernel-figure:: dp-mst/topology-figure-3.dot
952 *
953 * And finally, remove payload #2 by communicating with port #2 through
954 * sideband transactions.
955 */
956
957/**
958 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
959 * device
960 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
961 *
962 * Increments &drm_dp_mst_branch.malloc_kref. When
963 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
964 * will be released and @mstb may no longer be used.
965 *
966 * See also: drm_dp_mst_put_mstb_malloc()
967 */
968static void
969drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
970{
971 kref_get(&mstb->malloc_kref);
972 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
973}
974
975/**
976 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
977 * device
978 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
979 *
980 * Decrements &drm_dp_mst_branch.malloc_kref. When
981 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
982 * will be released and @mstb may no longer be used.
983 *
984 * See also: drm_dp_mst_get_mstb_malloc()
985 */
986static void
987drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
988{
989 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
990 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
991}
992
993static void drm_dp_free_mst_port(struct kref *kref)
994{
995 struct drm_dp_mst_port *port =
996 container_of(kref, struct drm_dp_mst_port, malloc_kref);
997
998 drm_dp_mst_put_mstb_malloc(port->parent);
999 kfree(port);
1000}
1001
1002/**
1003 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
1004 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of
1005 *
1006 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1007 * reaches 0, the memory allocation for @port will be released and @port may
1008 * no longer be used.
1009 *
1010 * Because @port could potentially be freed at any time by the DP MST helpers
1011 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
1012 * function, drivers that which to make use of &struct drm_dp_mst_port should
1013 * ensure that they grab at least one main malloc reference to their MST ports
1014 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
1015 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
1016 *
1017 * See also: drm_dp_mst_put_port_malloc()
1018 */
1019void
1020drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
1021{
1022 kref_get(&port->malloc_kref);
1023 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref));
1024}
1025EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
1026
1027/**
1028 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
1029 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
1030 *
1031 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1032 * reaches 0, the memory allocation for @port will be released and @port may
1033 * no longer be used.
1034 *
1035 * See also: drm_dp_mst_get_port_malloc()
1036 */
1037void
1038drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
1039{
1040 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
1041 kref_put(&port->malloc_kref, drm_dp_free_mst_port);
1042}
1043EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
1044
ad7f8a1f
DA		 1045static void drm_dp_destroy_mst_branch_device(struct kref *kref)
1046{
ebcc0e6b
LP		 1047 struct drm_dp_mst_branch *mstb =
1048 container_of(kref, struct drm_dp_mst_branch, topology_kref);
1049 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
ad7f8a1f
DA		 1050 struct drm_dp_mst_port *port, *tmp;
1051 bool wake_tx = false;
1052
ebcc0e6b 1053 mutex_lock(&mgr->lock);
ad7f8a1f
DA		 1054 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
1055 list_del(&port->next);
d0757afd 1056 drm_dp_mst_topology_put_port(port);
ad7f8a1f 1057 }
ebcc0e6b 1058 mutex_unlock(&mgr->lock);
ad7f8a1f
DA		 1059
1060 /* drop any tx slots msg */
1061 mutex_lock(&mstb->mgr->qlock);
1062 if (mstb->tx_slots[0]) {
1063 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1064 mstb->tx_slots[0] = NULL;
1065 wake_tx = true;
1066 }
1067 if (mstb->tx_slots[1]) {
1068 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1069 mstb->tx_slots[1] = NULL;
1070 wake_tx = true;
1071 }
1072 mutex_unlock(&mstb->mgr->qlock);
1073
1074 if (wake_tx)
68e989dc 1075 wake_up_all(&mstb->mgr->tx_waitq);
91a25e46 1076
ebcc0e6b 1077 drm_dp_mst_put_mstb_malloc(mstb);
ad7f8a1f
DA		 1078}
1079
ebcc0e6b
LP		 1080/**
1081 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1082 * branch device unless its zero
1083 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
1084 *
1085 * Attempts to grab a topology reference to @mstb, if it hasn't yet been
1086 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
1087 * reached 0). Holding a topology reference implies that a malloc reference
1088 * will be held to @mstb as long as the user holds the topology reference.
1089 *
1090 * Care should be taken to ensure that the user has at least one malloc
1091 * reference to @mstb. If you already have a topology reference to @mstb, you
1092 * should use drm_dp_mst_topology_get_mstb() instead.
1093 *
1094 * See also:
1095 * drm_dp_mst_topology_get_mstb()
1096 * drm_dp_mst_topology_put_mstb()
1097 *
1098 * Returns:
1099 * * 1: A topology reference was grabbed successfully
1100 * * 0: @port is no longer in the topology, no reference was grabbed
1101 */
1102static int __must_check
1103drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
ad7f8a1f 1104{
ebcc0e6b
LP		 1105 int ret = kref_get_unless_zero(&mstb->topology_kref);
1106
1107 if (ret)
1108 DRM_DEBUG("mstb %p (%d)\n", mstb,
1109 kref_read(&mstb->topology_kref));
1110
1111 return ret;
ad7f8a1f
DA		 1112}
1113
ebcc0e6b
LP		 1114/**
1115 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
1116 * branch device
1117 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
1118 *
1119 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or
1120 * not it's already reached 0. This is only valid to use in scenarios where
1121 * you are already guaranteed to have at least one active topology reference
1122 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
1123 *
1124 * See also:
1125 * drm_dp_mst_topology_try_get_mstb()
1126 * drm_dp_mst_topology_put_mstb()
1127 */
1128static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
1129{
1130 WARN_ON(kref_read(&mstb->topology_kref) == 0);
1131 kref_get(&mstb->topology_kref);
1132 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1133}
1134
1135/**
1136 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
1137 * device
1138 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from
1139 *
1140 * Releases a topology reference from @mstb by decrementing
1141 * &drm_dp_mst_branch.topology_kref.
1142 *
1143 * See also:
1144 * drm_dp_mst_topology_try_get_mstb()
1145 * drm_dp_mst_topology_get_mstb()
1146 */
1147static void
1148drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
1149{
1150 DRM_DEBUG("mstb %p (%d)\n",
1151 mstb, kref_read(&mstb->topology_kref) - 1);
1152 kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
1153}
ad7f8a1f
DA		 1154
1155static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
1156{
0391359d
DV		 1157 struct drm_dp_mst_branch *mstb;
1158
ad7f8a1f
DA		 1159 switch (old_pdt) {
1160 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1161 case DP_PEER_DEVICE_SST_SINK:
1162 /* remove i2c over sideband */
1163 drm_dp_mst_unregister_i2c_bus(&port->aux);
1164 break;
1165 case DP_PEER_DEVICE_MST_BRANCHING:
0391359d 1166 mstb = port->mstb;
ad7f8a1f 1167 port->mstb = NULL;
d0757afd 1168 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 1169 break;
1170 }
1171}
1172
1173static void drm_dp_destroy_port(struct kref *kref)
1174{
ebcc0e6b
LP		 1175 struct drm_dp_mst_port *port =
1176 container_of(kref, struct drm_dp_mst_port, topology_kref);
ad7f8a1f 1177 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
df4839fd 1178
ad7f8a1f 1179 if (!port->input) {
c6a0aed4 1180 kfree(port->cached_edid);
6b8eeca6 1181
df4839fd
DA		 1182 /*
1183 * The only time we don't have a connector
1184 * on an output port is if the connector init
1185 * fails.
1186 */
6b8eeca6 1187 if (port->connector) {
df4839fd
DA		 1188 /* we can't destroy the connector here, as
1189 * we might be holding the mode_config.mutex
1190 * from an EDID retrieval */
1191
6b8eeca6 1192 mutex_lock(&mgr->destroy_connector_lock);
4772ff03 1193 list_add(&port->next, &mgr->destroy_connector_list);
6b8eeca6
DA		 1194 mutex_unlock(&mgr->destroy_connector_lock);
1195 schedule_work(&mgr->destroy_connector_work);
4772ff03 1196 return;
6b8eeca6 1197 }
df4839fd
DA		 1198 /* no need to clean up vcpi
1199 * as if we have no connector we never setup a vcpi */
ad7f8a1f 1200 drm_dp_port_teardown_pdt(port, port->pdt);
36e3fa6a 1201 port->pdt = DP_PEER_DEVICE_NONE;
ad7f8a1f 1202 }
ebcc0e6b
LP		 1203 drm_dp_mst_put_port_malloc(port);
1204}
1205
1206/**
1207 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
1208 * port unless its zero
1209 * @port: &struct drm_dp_mst_port to increment the topology refcount of
1210 *
1211 * Attempts to grab a topology reference to @port, if it hasn't yet been
1212 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
1213 * 0). Holding a topology reference implies that a malloc reference will be
1214 * held to @port as long as the user holds the topology reference.
1215 *
1216 * Care should be taken to ensure that the user has at least one malloc
1217 * reference to @port. If you already have a topology reference to @port, you
1218 * should use drm_dp_mst_topology_get_port() instead.
1219 *
1220 * See also:
1221 * drm_dp_mst_topology_get_port()
1222 * drm_dp_mst_topology_put_port()
1223 *
1224 * Returns:
1225 * * 1: A topology reference was grabbed successfully
1226 * * 0: @port is no longer in the topology, no reference was grabbed
1227 */
1228static int __must_check
1229drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
1230{
1231 int ret = kref_get_unless_zero(&port->topology_kref);
1232
1233 if (ret)
1234 DRM_DEBUG("port %p (%d)\n", port,
1235 kref_read(&port->topology_kref));
1236
1237 return ret;
ad7f8a1f
DA		 1238}
1239
ebcc0e6b
LP		 1240/**
1241 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
1242 * @port: The &struct drm_dp_mst_port to increment the topology refcount of
1243 *
1244 * Increments &drm_dp_mst_port.topology_refcount without checking whether or
1245 * not it's already reached 0. This is only valid to use in scenarios where
1246 * you are already guaranteed to have at least one active topology reference
1247 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
1248 *
1249 * See also:
1250 * drm_dp_mst_topology_try_get_port()
1251 * drm_dp_mst_topology_put_port()
1252 */
1253static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
1254{
1255 WARN_ON(kref_read(&port->topology_kref) == 0);
1256 kref_get(&port->topology_kref);
1257 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref));
1258}
1259
1260/**
1261 * drm_dp_mst_topology_put_port() - release a topology reference to a port
1262 * @port: The &struct drm_dp_mst_port to release the topology reference from
1263 *
1264 * Releases a topology reference from @port by decrementing
1265 * &drm_dp_mst_port.topology_kref.
1266 *
1267 * See also:
1268 * drm_dp_mst_topology_try_get_port()
1269 * drm_dp_mst_topology_get_port()
1270 */
d0757afd 1271static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
ad7f8a1f 1272{
ebcc0e6b
LP		 1273 DRM_DEBUG("port %p (%d)\n",
1274 port, kref_read(&port->topology_kref) - 1);
1275 kref_put(&port->topology_kref, drm_dp_destroy_port);
ad7f8a1f
DA		 1276}
1277
d0757afd
LP		 1278static struct drm_dp_mst_branch *
1279drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
1280 struct drm_dp_mst_branch *to_find)
ad7f8a1f
DA		 1281{
1282 struct drm_dp_mst_port *port;
1283 struct drm_dp_mst_branch *rmstb;
ebcc0e6b
LP		 1284
1285 if (to_find == mstb)
ad7f8a1f 1286 return mstb;
ebcc0e6b 1287
ad7f8a1f
DA		 1288 list_for_each_entry(port, &mstb->ports, next) {
1289 if (port->mstb) {
d0757afd
LP		 1290 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1291 port->mstb, to_find);
ad7f8a1f
DA		 1292 if (rmstb)
1293 return rmstb;
1294 }
1295 }
1296 return NULL;
1297}
1298
d0757afd
LP		 1299static struct drm_dp_mst_branch *
1300drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
1301 struct drm_dp_mst_branch *mstb)
ad7f8a1f
DA		 1302{
1303 struct drm_dp_mst_branch *rmstb = NULL;
ebcc0e6b 1304
ad7f8a1f 1305 mutex_lock(&mgr->lock);
ebcc0e6b 1306 if (mgr->mst_primary) {
d0757afd
LP		 1307 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1308 mgr->mst_primary, mstb);
ebcc0e6b
LP		 1309
1310 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
1311 rmstb = NULL;
1312 }
ad7f8a1f
DA		 1313 mutex_unlock(&mgr->lock);
1314 return rmstb;
1315}
1316
ebcc0e6b
LP		 1317static struct drm_dp_mst_port *
1318drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
1319 struct drm_dp_mst_port *to_find)
ad7f8a1f
DA		 1320{
1321 struct drm_dp_mst_port *port, *mport;
1322
1323 list_for_each_entry(port, &mstb->ports, next) {
ebcc0e6b 1324 if (port == to_find)
ad7f8a1f 1325 return port;
ebcc0e6b 1326
ad7f8a1f 1327 if (port->mstb) {
ebcc0e6b
LP		 1328 mport = drm_dp_mst_topology_get_port_validated_locked(
1329 port->mstb, to_find);
ad7f8a1f
DA		 1330 if (mport)
1331 return mport;
1332 }
1333 }
1334 return NULL;
1335}
1336
d0757afd
LP		 1337static struct drm_dp_mst_port *
1338drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
1339 struct drm_dp_mst_port *port)
ad7f8a1f
DA		 1340{
1341 struct drm_dp_mst_port *rport = NULL;
ebcc0e6b 1342
ad7f8a1f 1343 mutex_lock(&mgr->lock);
ebcc0e6b
LP		 1344 if (mgr->mst_primary) {
1345 rport = drm_dp_mst_topology_get_port_validated_locked(
1346 mgr->mst_primary, port);
1347
1348 if (rport && !drm_dp_mst_topology_try_get_port(rport))
1349 rport = NULL;
1350 }
ad7f8a1f
DA		 1351 mutex_unlock(&mgr->lock);
1352 return rport;
1353}
1354
1355static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
1356{
1357 struct drm_dp_mst_port *port;
ebcc0e6b 1358 int ret;
ad7f8a1f
DA		 1359
1360 list_for_each_entry(port, &mstb->ports, next) {
1361 if (port->port_num == port_num) {
ebcc0e6b
LP		 1362 ret = drm_dp_mst_topology_try_get_port(port);
1363 return ret ? port : NULL;
ad7f8a1f
DA		 1364 }
1365 }
1366
1367 return NULL;
1368}
1369
1370/*
1371 * calculate a new RAD for this MST branch device
1372 * if parent has an LCT of 2 then it has 1 nibble of RAD,
1373 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1374 */
1375static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1376 u8 *rad)
1377{
75af4c8c 1378 int parent_lct = port->parent->lct;
ad7f8a1f 1379 int shift = 4;
75af4c8c
ML		 1380 int idx = (parent_lct - 1) / 2;
1381 if (parent_lct > 1) {
1382 memcpy(rad, port->parent->rad, idx + 1);
1383 shift = (parent_lct % 2) ? 4 : 0;
ad7f8a1f
DA		 1384 } else
1385 rad[0] = 0;
1386
1387 rad[idx] |= port->port_num << shift;
75af4c8c 1388 return parent_lct + 1;
ad7f8a1f
DA		 1389}
1390
1391/*
1392 * return sends link address for new mstb
1393 */
1394static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
1395{
1396 int ret;
1397 u8 rad[6], lct;
1398 bool send_link = false;
1399 switch (port->pdt) {
1400 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1401 case DP_PEER_DEVICE_SST_SINK:
1402 /* add i2c over sideband */
1403 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1404 break;
1405 case DP_PEER_DEVICE_MST_BRANCHING:
1406 lct = drm_dp_calculate_rad(port, rad);
1407
1408 port->mstb = drm_dp_add_mst_branch_device(lct, rad);
22a07038
JM		 1409 if (port->mstb) {
1410 port->mstb->mgr = port->mgr;
1411 port->mstb->port_parent = port;
ebcc0e6b
LP		 1412 /*
1413 * Make sure this port's memory allocation stays
1414 * around until it's child MSTB releases it
1415 */
1416 drm_dp_mst_get_port_malloc(port);
ad7f8a1f 1417
22a07038
JM		 1418 send_link = true;
1419 }
ad7f8a1f
DA		 1420 break;
1421 }
1422 return send_link;
1423}
1424
5e93b820 1425static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
ad7f8a1f
DA		 1426{
1427 int ret;
5e93b820
HW		 1428
1429 memcpy(mstb->guid, guid, 16);
1430
1431 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
1432 if (mstb->port_parent) {
1433 ret = drm_dp_send_dpcd_write(
1434 mstb->mgr,
1435 mstb->port_parent,
1436 DP_GUID,
1437 16,
1438 mstb->guid);
1439 } else {
1440
1441 ret = drm_dp_dpcd_write(
1442 mstb->mgr->aux,
1443 DP_GUID,
1444 mstb->guid,
1445 16);
ad7f8a1f
DA		 1446 }
1447 }
1448}
1449
1c960876
DA		 1450static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1451 int pnum,
d87af4d1
RS		 1452 char *proppath,
1453 size_t proppath_size)
ad7f8a1f
DA		 1454{
1455 int i;
1456 char temp[8];
d87af4d1 1457 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
ad7f8a1f
DA		 1458 for (i = 0; i < (mstb->lct - 1); i++) {
1459 int shift = (i % 2) ? 0 : 4;
7a11a334 1460 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
d87af4d1
RS		 1461 snprintf(temp, sizeof(temp), "-%d", port_num);
1462 strlcat(proppath, temp, proppath_size);
ad7f8a1f 1463 }
1c960876 1464 snprintf(temp, sizeof(temp), "-%d", pnum);
d87af4d1 1465 strlcat(proppath, temp, proppath_size);
ad7f8a1f
DA		 1466}
1467
1468static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
7b0a89a6 1469 struct drm_device *dev,
ad7f8a1f
DA		 1470 struct drm_dp_link_addr_reply_port *port_msg)
1471{
1472 struct drm_dp_mst_port *port;
1473 bool ret;
1474 bool created = false;
1475 int old_pdt = 0;
1476 int old_ddps = 0;
ebcc0e6b 1477
ad7f8a1f
DA		 1478 port = drm_dp_get_port(mstb, port_msg->port_number);
1479 if (!port) {
1480 port = kzalloc(sizeof(*port), GFP_KERNEL);
1481 if (!port)
1482 return;
ebcc0e6b
LP		 1483 kref_init(&port->topology_kref);
1484 kref_init(&port->malloc_kref);
ad7f8a1f
DA		 1485 port->parent = mstb;
1486 port->port_num = port_msg->port_number;
1487 port->mgr = mstb->mgr;
1488 port->aux.name = "DPMST";
7b0a89a6 1489 port->aux.dev = dev->dev;
ebcc0e6b
LP		 1490
1491 /*
1492 * Make sure the memory allocation for our parent branch stays
1493 * around until our own memory allocation is released
1494 */
1495 drm_dp_mst_get_mstb_malloc(mstb);
1496
ad7f8a1f
DA		 1497 created = true;
1498 } else {
1499 old_pdt = port->pdt;
1500 old_ddps = port->ddps;
1501 }
1502
1503 port->pdt = port_msg->peer_device_type;
1504 port->input = port_msg->input_port;
1505 port->mcs = port_msg->mcs;
1506 port->ddps = port_msg->ddps;
1507 port->ldps = port_msg->legacy_device_plug_status;
1508 port->dpcd_rev = port_msg->dpcd_revision;
1509 port->num_sdp_streams = port_msg->num_sdp_streams;
1510 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
ad7f8a1f
DA		 1511
1512 /* manage mstb port lists with mgr lock - take a reference
1513 for this list */
1514 if (created) {
1515 mutex_lock(&mstb->mgr->lock);
ebcc0e6b 1516 drm_dp_mst_topology_get_port(port);
ad7f8a1f
DA		 1517 list_add(&port->next, &mstb->ports);
1518 mutex_unlock(&mstb->mgr->lock);
1519 }
1520
1521 if (old_ddps != port->ddps) {
1522 if (port->ddps) {
3d76df63
LP		 1523 if (!port->input) {
1524 drm_dp_send_enum_path_resources(mstb->mgr,
1525 mstb, port);
1526 }
ad7f8a1f 1527 } else {
ad7f8a1f 1528 port->available_pbn = 0;
3d76df63 1529 }
ad7f8a1f
DA		 1530 }
1531
1532 if (old_pdt != port->pdt && !port->input) {
1533 drm_dp_port_teardown_pdt(port, old_pdt);
1534
1535 ret = drm_dp_port_setup_pdt(port);
68d8c9fc 1536 if (ret == true)
ad7f8a1f 1537 drm_dp_send_link_address(mstb->mgr, port->mstb);
ad7f8a1f
DA		 1538 }
1539
1540 if (created && !port->input) {
1541 char proppath[255];
1c960876 1542
3d76df63
LP		 1543 build_mst_prop_path(mstb, port->port_num, proppath,
1544 sizeof(proppath));
1545 port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr,
1546 port,
1547 proppath);
df4839fd
DA		 1548 if (!port->connector) {
1549 /* remove it from the port list */
1550 mutex_lock(&mstb->mgr->lock);
1551 list_del(&port->next);
1552 mutex_unlock(&mstb->mgr->lock);
1553 /* drop port list reference */
d0757afd 1554 drm_dp_mst_topology_put_port(port);
df4839fd
DA		 1555 goto out;
1556 }
4da5caa6
VS		 1557 if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
1558 port->pdt == DP_PEER_DEVICE_SST_SINK) &&
1559 port->port_num >= DP_MST_LOGICAL_PORT_0) {
3d76df63
LP		 1560 port->cached_edid = drm_get_edid(port->connector,
1561 &port->aux.ddc);
97e14fbe 1562 drm_connector_set_tile_property(port->connector);
8ae22cb4 1563 }
d9515c5e 1564 (*mstb->mgr->cbs->register_connector)(port->connector);
ad7f8a1f 1565 }
8ae22cb4 1566
df4839fd 1567out:
ad7f8a1f 1568 /* put reference to this port */
d0757afd 1569 drm_dp_mst_topology_put_port(port);
ad7f8a1f
DA		 1570}
1571
1572static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1573 struct drm_dp_connection_status_notify *conn_stat)
1574{
1575 struct drm_dp_mst_port *port;
1576 int old_pdt;
1577 int old_ddps;
1578 bool dowork = false;
1579 port = drm_dp_get_port(mstb, conn_stat->port_number);
1580 if (!port)
1581 return;
1582
1583 old_ddps = port->ddps;
1584 old_pdt = port->pdt;
1585 port->pdt = conn_stat->peer_device_type;
1586 port->mcs = conn_stat->message_capability_status;
1587 port->ldps = conn_stat->legacy_device_plug_status;
1588 port->ddps = conn_stat->displayport_device_plug_status;
1589
1590 if (old_ddps != port->ddps) {
1591 if (port->ddps) {
8ae22cb4 1592 dowork = true;
ad7f8a1f 1593 } else {
ad7f8a1f
DA		 1594 port->available_pbn = 0;
1595 }
1596 }
1597 if (old_pdt != port->pdt && !port->input) {
1598 drm_dp_port_teardown_pdt(port, old_pdt);
1599
1600 if (drm_dp_port_setup_pdt(port))
1601 dowork = true;
1602 }
1603
d0757afd 1604 drm_dp_mst_topology_put_port(port);
ad7f8a1f
DA		 1605 if (dowork)
1606 queue_work(system_long_wq, &mstb->mgr->work);
1607
1608}
1609
1610static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1611 u8 lct, u8 *rad)
1612{
1613 struct drm_dp_mst_branch *mstb;
1614 struct drm_dp_mst_port *port;
ebcc0e6b 1615 int i, ret;
ad7f8a1f 1616 /* find the port by iterating down */
9eb1e57f
DA		 1617
1618 mutex_lock(&mgr->lock);
ad7f8a1f
DA		 1619 mstb = mgr->mst_primary;
1620
23d80039
SL		 1621 if (!mstb)
1622 goto out;
1623
ad7f8a1f
DA		 1624 for (i = 0; i < lct - 1; i++) {
1625 int shift = (i % 2) ? 0 : 4;
7a11a334 1626 int port_num = (rad[i / 2] >> shift) & 0xf;
ad7f8a1f
DA		 1627
1628 list_for_each_entry(port, &mstb->ports, next) {
1629 if (port->port_num == port_num) {
30730c7f
AR		 1630 mstb = port->mstb;
1631 if (!mstb) {
ad7f8a1f 1632 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
30730c7f 1633 goto out;
ad7f8a1f
DA		 1634 }
1635
ad7f8a1f
DA		 1636 break;
1637 }
1638 }
1639 }
ebcc0e6b
LP		 1640 ret = drm_dp_mst_topology_try_get_mstb(mstb);
1641 if (!ret)
1642 mstb = NULL;
30730c7f 1643out:
9eb1e57f 1644 mutex_unlock(&mgr->lock);
ad7f8a1f
DA		 1645 return mstb;
1646}
1647
bd934320
ML		 1648static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1649 struct drm_dp_mst_branch *mstb,
1650 uint8_t *guid)
1651{
1652 struct drm_dp_mst_branch *found_mstb;
1653 struct drm_dp_mst_port *port;
1654
5e93b820
HW		 1655 if (memcmp(mstb->guid, guid, 16) == 0)
1656 return mstb;
1657
1658
bd934320
ML		 1659 list_for_each_entry(port, &mstb->ports, next) {
1660 if (!port->mstb)
1661 continue;
1662
bd934320
ML		 1663 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1664
1665 if (found_mstb)
1666 return found_mstb;
1667 }
1668
1669 return NULL;
1670}
1671
de6d6818
LP		 1672static struct drm_dp_mst_branch *
1673drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
1674 uint8_t *guid)
bd934320
ML		 1675{
1676 struct drm_dp_mst_branch *mstb;
ebcc0e6b 1677 int ret;
bd934320
ML		 1678
1679 /* find the port by iterating down */
1680 mutex_lock(&mgr->lock);
1681
5e93b820 1682 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
ebcc0e6b
LP		 1683 if (mstb) {
1684 ret = drm_dp_mst_topology_try_get_mstb(mstb);
1685 if (!ret)
1686 mstb = NULL;
1687 }
bd934320
ML		 1688
1689 mutex_unlock(&mgr->lock);
1690 return mstb;
1691}
1692
ad7f8a1f
DA		 1693static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1694 struct drm_dp_mst_branch *mstb)
1695{
1696 struct drm_dp_mst_port *port;
9254ec49 1697 struct drm_dp_mst_branch *mstb_child;
68d8c9fc 1698 if (!mstb->link_address_sent)
ad7f8a1f 1699 drm_dp_send_link_address(mgr, mstb);
68d8c9fc 1700
ad7f8a1f
DA		 1701 list_for_each_entry(port, &mstb->ports, next) {
1702 if (port->input)
1703 continue;
1704
8ae22cb4 1705 if (!port->ddps)
ad7f8a1f
DA		 1706 continue;
1707
1708 if (!port->available_pbn)
1709 drm_dp_send_enum_path_resources(mgr, mstb, port);
1710
9254ec49 1711 if (port->mstb) {
d0757afd
LP		 1712 mstb_child = drm_dp_mst_topology_get_mstb_validated(
1713 mgr, port->mstb);
9254ec49
DV		 1714 if (mstb_child) {
1715 drm_dp_check_and_send_link_address(mgr, mstb_child);
d0757afd 1716 drm_dp_mst_topology_put_mstb(mstb_child);
9254ec49
DV		 1717 }
1718 }
ad7f8a1f
DA		 1719 }
1720}
1721
1722static void drm_dp_mst_link_probe_work(struct work_struct *work)
1723{
1724 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
9254ec49 1725 struct drm_dp_mst_branch *mstb;
ebcc0e6b 1726 int ret;
ad7f8a1f 1727
9254ec49
DV		 1728 mutex_lock(&mgr->lock);
1729 mstb = mgr->mst_primary;
1730 if (mstb) {
ebcc0e6b
LP		 1731 ret = drm_dp_mst_topology_try_get_mstb(mstb);
1732 if (!ret)
1733 mstb = NULL;
9254ec49
DV		 1734 }
1735 mutex_unlock(&mgr->lock);
1736 if (mstb) {
1737 drm_dp_check_and_send_link_address(mgr, mstb);
d0757afd 1738 drm_dp_mst_topology_put_mstb(mstb);
9254ec49 1739 }
ad7f8a1f
DA		 1740}
1741
1742static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1743 u8 *guid)
1744{
e38e1289 1745 u64 salt;
ad7f8a1f 1746
e38e1289
VS		 1747 if (memchr_inv(guid, 0, 16))
1748 return true;
1749
1750 salt = get_jiffies_64();
1751
1752 memcpy(&guid[0], &salt, sizeof(u64));
1753 memcpy(&guid[8], &salt, sizeof(u64));
1754
1755 return false;
ad7f8a1f
DA		 1756}
1757
1758#if 0
1759static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1760{
1761 struct drm_dp_sideband_msg_req_body req;
1762
1763 req.req_type = DP_REMOTE_DPCD_READ;
1764 req.u.dpcd_read.port_number = port_num;
1765 req.u.dpcd_read.dpcd_address = offset;
1766 req.u.dpcd_read.num_bytes = num_bytes;
1767 drm_dp_encode_sideband_req(&req, msg);
1768
1769 return 0;
1770}
1771#endif
1772
1773static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1774 bool up, u8 *msg, int len)
1775{
1776 int ret;
1777 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1778 int tosend, total, offset;
1779 int retries = 0;
1780
1781retry:
1782 total = len;
1783 offset = 0;
1784 do {
1785 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1786
1787 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1788 &msg[offset],
1789 tosend);
1790 if (ret != tosend) {
1791 if (ret == -EIO && retries < 5) {
1792 retries++;
1793 goto retry;
1794 }
1795 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
ad7f8a1f
DA		 1796
1797 return -EIO;
1798 }
1799 offset += tosend;
1800 total -= tosend;
1801 } while (total > 0);
1802 return 0;
1803}
1804
1805static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1806 struct drm_dp_sideband_msg_tx *txmsg)
1807{
1808 struct drm_dp_mst_branch *mstb = txmsg->dst;
bd934320 1809 u8 req_type;
ad7f8a1f
DA		 1810
1811 /* both msg slots are full */
1812 if (txmsg->seqno == -1) {
1813 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1814 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1815 return -EAGAIN;
1816 }
1817 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1818 txmsg->seqno = mstb->last_seqno;
1819 mstb->last_seqno ^= 1;
1820 } else if (mstb->tx_slots[0] == NULL)
1821 txmsg->seqno = 0;
1822 else
1823 txmsg->seqno = 1;
1824 mstb->tx_slots[txmsg->seqno] = txmsg;
1825 }
bd934320
ML		 1826
1827 req_type = txmsg->msg[0] & 0x7f;
1828 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1829 req_type == DP_RESOURCE_STATUS_NOTIFY)
1830 hdr->broadcast = 1;
1831 else
1832 hdr->broadcast = 0;
ad7f8a1f
DA		 1833 hdr->path_msg = txmsg->path_msg;
1834 hdr->lct = mstb->lct;
1835 hdr->lcr = mstb->lct - 1;
1836 if (mstb->lct > 1)
1837 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1838 hdr->seqno = txmsg->seqno;
1839 return 0;
1840}
1841/*
1842 * process a single block of the next message in the sideband queue
1843 */
1844static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1845 struct drm_dp_sideband_msg_tx *txmsg,
1846 bool up)
1847{
1848 u8 chunk[48];
1849 struct drm_dp_sideband_msg_hdr hdr;
1850 int len, space, idx, tosend;
1851 int ret;
1852
bf3719c0
DL		 1853 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1854
ad7f8a1f
DA		 1855 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1856 txmsg->seqno = -1;
1857 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1858 }
1859
1860 /* make hdr from dst mst - for replies use seqno
1861 otherwise assign one */
1862 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1863 if (ret < 0)
1864 return ret;
1865
1866 /* amount left to send in this message */
1867 len = txmsg->cur_len - txmsg->cur_offset;
1868
1869 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1870 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1871
1872 tosend = min(len, space);
1873 if (len == txmsg->cur_len)
1874 hdr.somt = 1;
1875 if (space >= len)
1876 hdr.eomt = 1;
1877
1878
1879 hdr.msg_len = tosend + 1;
1880 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1881 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1882 /* add crc at end */
1883 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1884 idx += tosend + 1;
1885
1886 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1887 if (ret) {
1888 DRM_DEBUG_KMS("sideband msg failed to send\n");
1889 return ret;
1890 }
1891
1892 txmsg->cur_offset += tosend;
1893 if (txmsg->cur_offset == txmsg->cur_len) {
1894 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1895 return 1;
1896 }
1897 return 0;
1898}
1899
ad7f8a1f
DA		 1900static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1901{
1902 struct drm_dp_sideband_msg_tx *txmsg;
1903 int ret;
1904
cd961bb9
DV		 1905 WARN_ON(!mutex_is_locked(&mgr->qlock));
1906
ad7f8a1f 1907 /* construct a chunk from the first msg in the tx_msg queue */
cb021a3e 1908 if (list_empty(&mgr->tx_msg_downq))
ad7f8a1f 1909 return;
ad7f8a1f
DA		 1910
1911 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1912 ret = process_single_tx_qlock(mgr, txmsg, false);
1913 if (ret == 1) {
1914 /* txmsg is sent it should be in the slots now */
1915 list_del(&txmsg->next);
1916 } else if (ret) {
1917 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1918 list_del(&txmsg->next);
1919 if (txmsg->seqno != -1)
1920 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1921 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
68e989dc 1922 wake_up_all(&mgr->tx_waitq);
ad7f8a1f 1923 }
ad7f8a1f
DA		 1924}
1925
1926/* called holding qlock */
1f16ee7f
ML		 1927static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1928 struct drm_dp_sideband_msg_tx *txmsg)
ad7f8a1f 1929{
ad7f8a1f
DA		 1930 int ret;
1931
1932 /* construct a chunk from the first msg in the tx_msg queue */
ad7f8a1f 1933 ret = process_single_tx_qlock(mgr, txmsg, true);
1f16ee7f
ML		 1934
1935 if (ret != 1)
ad7f8a1f 1936 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1f16ee7f
ML		 1937
1938 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
ad7f8a1f
DA		 1939}
1940
1941static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1942 struct drm_dp_sideband_msg_tx *txmsg)
1943{
1944 mutex_lock(&mgr->qlock);
1945 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
cb021a3e 1946 if (list_is_singular(&mgr->tx_msg_downq))
ad7f8a1f
DA		 1947 process_single_down_tx_qlock(mgr);
1948 mutex_unlock(&mgr->qlock);
1949}
1950
68d8c9fc
DA		 1951static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1952 struct drm_dp_mst_branch *mstb)
ad7f8a1f
DA		 1953{
1954 int len;
1955 struct drm_dp_sideband_msg_tx *txmsg;
1956 int ret;
1957
1958 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1959 if (!txmsg)
68d8c9fc 1960 return;
ad7f8a1f
DA		 1961
1962 txmsg->dst = mstb;
1963 len = build_link_address(txmsg);
1964
68d8c9fc 1965 mstb->link_address_sent = true;
ad7f8a1f
DA		 1966 drm_dp_queue_down_tx(mgr, txmsg);
1967
1968 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1969 if (ret > 0) {
1970 int i;
1971
1972 if (txmsg->reply.reply_type == 1)
1973 DRM_DEBUG_KMS("link address nak received\n");
1974 else {
1975 DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1976 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1977 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,
1978 txmsg->reply.u.link_addr.ports[i].input_port,
1979 txmsg->reply.u.link_addr.ports[i].peer_device_type,
1980 txmsg->reply.u.link_addr.ports[i].port_number,
1981 txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1982 txmsg->reply.u.link_addr.ports[i].mcs,
1983 txmsg->reply.u.link_addr.ports[i].ddps,
1984 txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1985 txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1986 txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1987 }
5e93b820
HW		 1988
1989 drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
1990
ad7f8a1f
DA		 1991 for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1992 drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1993 }
16bff572 1994 drm_kms_helper_hotplug_event(mgr->dev);
ad7f8a1f 1995 }
68d8c9fc
DA		 1996 } else {
1997 mstb->link_address_sent = false;
ad7f8a1f 1998 DRM_DEBUG_KMS("link address failed %d\n", ret);
68d8c9fc 1999 }
ad7f8a1f
DA		 2000
2001 kfree(txmsg);
ad7f8a1f
DA		 2002}
2003
2004static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
2005 struct drm_dp_mst_branch *mstb,
2006 struct drm_dp_mst_port *port)
2007{
2008 int len;
2009 struct drm_dp_sideband_msg_tx *txmsg;
2010 int ret;
2011
2012 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2013 if (!txmsg)
2014 return -ENOMEM;
2015
2016 txmsg->dst = mstb;
2017 len = build_enum_path_resources(txmsg, port->port_num);
2018
2019 drm_dp_queue_down_tx(mgr, txmsg);
2020
2021 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2022 if (ret > 0) {
2023 if (txmsg->reply.reply_type == 1)
2024 DRM_DEBUG_KMS("enum path resources nak received\n");
2025 else {
2026 if (port->port_num != txmsg->reply.u.path_resources.port_number)
2027 DRM_ERROR("got incorrect port in response\n");
2028 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,
2029 txmsg->reply.u.path_resources.avail_payload_bw_number);
2030 port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
2031 }
2032 }
2033
2034 kfree(txmsg);
2035 return 0;
2036}
2037
91a25e46
ML		 2038static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
2039{
2040 if (!mstb->port_parent)
2041 return NULL;
2042
2043 if (mstb->port_parent->mstb != mstb)
2044 return mstb->port_parent;
2045
2046 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
2047}
2048
56d1c14e
LP		 2049/*
2050 * Searches upwards in the topology starting from mstb to try to find the
2051 * closest available parent of mstb that's still connected to the rest of the
2052 * topology. This can be used in order to perform operations like releasing
2053 * payloads, where the branch device which owned the payload may no longer be
2054 * around and thus would require that the payload on the last living relative
2055 * be freed instead.
2056 */
2057static struct drm_dp_mst_branch *
2058drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
2059 struct drm_dp_mst_branch *mstb,
2060 int *port_num)
91a25e46
ML		 2061{
2062 struct drm_dp_mst_branch *rmstb = NULL;
2063 struct drm_dp_mst_port *found_port;
56d1c14e 2064
91a25e46 2065 mutex_lock(&mgr->lock);
56d1c14e
LP		 2066 if (!mgr->mst_primary)
2067 goto out;
2068
2069 do {
91a25e46 2070 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
56d1c14e
LP		 2071 if (!found_port)
2072 break;
91a25e46 2073
56d1c14e 2074 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
91a25e46 2075 rmstb = found_port->parent;
56d1c14e
LP		 2076 *port_num = found_port->port_num;
2077 } else {
2078 /* Search again, starting from this parent */
2079 mstb = found_port->parent;
91a25e46 2080 }
56d1c14e
LP		 2081 } while (!rmstb);
2082out:
91a25e46
ML		 2083 mutex_unlock(&mgr->lock);
2084 return rmstb;
2085}
2086
8fa6a425
TR		 2087static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
2088 struct drm_dp_mst_port *port,
2089 int id,
2090 int pbn)
ad7f8a1f
DA		 2091{
2092 struct drm_dp_sideband_msg_tx *txmsg;
2093 struct drm_dp_mst_branch *mstb;
91a25e46 2094 int len, ret, port_num;
ef8f9bea
LY		 2095 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
2096 int i;
ad7f8a1f 2097
91a25e46 2098 port_num = port->port_num;
d0757afd 2099 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
91a25e46 2100 if (!mstb) {
de6d6818
LP		 2101 mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
2102 port->parent,
2103 &port_num);
91a25e46 2104
cfe9f903 2105 if (!mstb)
91a25e46
ML		 2106 return -EINVAL;
2107 }
ad7f8a1f
DA		 2108
2109 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2110 if (!txmsg) {
2111 ret = -ENOMEM;
2112 goto fail_put;
2113 }
2114
ef8f9bea
LY		 2115 for (i = 0; i < port->num_sdp_streams; i++)
2116 sinks[i] = i;
2117
ad7f8a1f 2118 txmsg->dst = mstb;
91a25e46 2119 len = build_allocate_payload(txmsg, port_num,
ad7f8a1f 2120 id,
ef8f9bea 2121 pbn, port->num_sdp_streams, sinks);
ad7f8a1f
DA		 2122
2123 drm_dp_queue_down_tx(mgr, txmsg);
2124
56d1c14e
LP		 2125 /*
2126 * FIXME: there is a small chance that between getting the last
2127 * connected mstb and sending the payload message, the last connected
2128 * mstb could also be removed from the topology. In the future, this
2129 * needs to be fixed by restarting the
2130 * drm_dp_get_last_connected_port_and_mstb() search in the event of a
2131 * timeout if the topology is still connected to the system.
2132 */
ad7f8a1f
DA		 2133 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2134 if (ret > 0) {
de6d6818 2135 if (txmsg->reply.reply_type == 1)
ad7f8a1f 2136 ret = -EINVAL;
de6d6818 2137 else
ad7f8a1f
DA		 2138 ret = 0;
2139 }
2140 kfree(txmsg);
2141fail_put:
d0757afd 2142 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 2143 return ret;
2144}
2145
0bb9c2b2
DP		 2146int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
2147 struct drm_dp_mst_port *port, bool power_up)
2148{
2149 struct drm_dp_sideband_msg_tx *txmsg;
2150 int len, ret;
2151
d0757afd 2152 port = drm_dp_mst_topology_get_port_validated(mgr, port);
0bb9c2b2
DP		 2153 if (!port)
2154 return -EINVAL;
2155
2156 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2157 if (!txmsg) {
d0757afd 2158 drm_dp_mst_topology_put_port(port);
0bb9c2b2
DP		 2159 return -ENOMEM;
2160 }
2161
2162 txmsg->dst = port->parent;
2163 len = build_power_updown_phy(txmsg, port->port_num, power_up);
2164 drm_dp_queue_down_tx(mgr, txmsg);
2165
2166 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
2167 if (ret > 0) {
2168 if (txmsg->reply.reply_type == 1)
2169 ret = -EINVAL;
2170 else
2171 ret = 0;
2172 }
2173 kfree(txmsg);
d0757afd 2174 drm_dp_mst_topology_put_port(port);
0bb9c2b2
DP		 2175
2176 return ret;
2177}
2178EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
2179
ad7f8a1f
DA		 2180static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
2181 int id,
2182 struct drm_dp_payload *payload)
2183{
2184 int ret;
2185
2186 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
2187 if (ret < 0) {
2188 payload->payload_state = 0;
2189 return ret;
2190 }
2191 payload->payload_state = DP_PAYLOAD_LOCAL;
2192 return 0;
2193}
2194
8fa6a425
TR		 2195static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
2196 struct drm_dp_mst_port *port,
2197 int id,
2198 struct drm_dp_payload *payload)
ad7f8a1f
DA		 2199{
2200 int ret;
2201 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
2202 if (ret < 0)
2203 return ret;
2204 payload->payload_state = DP_PAYLOAD_REMOTE;
2205 return ret;
2206}
2207
8fa6a425
TR		 2208static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
2209 struct drm_dp_mst_port *port,
2210 int id,
2211 struct drm_dp_payload *payload)
ad7f8a1f
DA		 2212{
2213 DRM_DEBUG_KMS("\n");
2214 /* its okay for these to fail */
2215 if (port) {
2216 drm_dp_payload_send_msg(mgr, port, id, 0);
2217 }
2218
2219 drm_dp_dpcd_write_payload(mgr, id, payload);
dfda0df3 2220 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
ad7f8a1f
DA		 2221 return 0;
2222}
2223
8fa6a425
TR		 2224static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
2225 int id,
2226 struct drm_dp_payload *payload)
ad7f8a1f
DA		 2227{
2228 payload->payload_state = 0;
2229 return 0;
2230}
2231
2232/**
2233 * drm_dp_update_payload_part1() - Execute payload update part 1
2234 * @mgr: manager to use.
2235 *
2236 * This iterates over all proposed virtual channels, and tries to
2237 * allocate space in the link for them. For 0->slots transitions,
2238 * this step just writes the VCPI to the MST device. For slots->0
2239 * transitions, this writes the updated VCPIs and removes the
2240 * remote VC payloads.
2241 *
2242 * after calling this the driver should generate ACT and payload
2243 * packets.
2244 */
2245int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
2246{
ad7f8a1f
DA		 2247 struct drm_dp_payload req_payload;
2248 struct drm_dp_mst_port *port;
cfe9f903
LP		 2249 int i, j;
2250 int cur_slots = 1;
ad7f8a1f
DA		 2251
2252 mutex_lock(&mgr->payload_lock);
2253 for (i = 0; i < mgr->max_payloads; i++) {
706246c7
LP		 2254 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
2255 struct drm_dp_payload *payload = &mgr->payloads[i];
cfe9f903 2256 bool put_port = false;
706246c7 2257
ad7f8a1f
DA		 2258 /* solve the current payloads - compare to the hw ones
2259 - update the hw view */
2260 req_payload.start_slot = cur_slots;
706246c7
LP		 2261 if (vcpi) {
2262 port = container_of(vcpi, struct drm_dp_mst_port,
2263 vcpi);
cfe9f903
LP		 2264
2265 /* Validated ports don't matter if we're releasing
2266 * VCPI
2267 */
2268 if (vcpi->num_slots) {
2269 port = drm_dp_mst_topology_get_port_validated(
2270 mgr, port);
2271 if (!port) {
2272 mutex_unlock(&mgr->payload_lock);
2273 return -EINVAL;
2274 }
2275 put_port = true;
263efde3 2276 }
cfe9f903 2277
706246c7
LP		 2278 req_payload.num_slots = vcpi->num_slots;
2279 req_payload.vcpi = vcpi->vcpi;
ad7f8a1f
DA		 2280 } else {
2281 port = NULL;
2282 req_payload.num_slots = 0;
2283 }
dfda0df3 2284
706246c7 2285 payload->start_slot = req_payload.start_slot;
ad7f8a1f 2286 /* work out what is required to happen with this payload */
706246c7 2287 if (payload->num_slots != req_payload.num_slots) {
ad7f8a1f
DA		 2288
2289 /* need to push an update for this payload */
2290 if (req_payload.num_slots) {
706246c7
LP		 2291 drm_dp_create_payload_step1(mgr, vcpi->vcpi,
2292 &req_payload);
2293 payload->num_slots = req_payload.num_slots;
2294 payload->vcpi = req_payload.vcpi;
2295
2296 } else if (payload->num_slots) {
2297 payload->num_slots = 0;
2298 drm_dp_destroy_payload_step1(mgr, port,
2299 payload->vcpi,
2300 payload);
2301 req_payload.payload_state =
2302 payload->payload_state;
2303 payload->start_slot = 0;
dfda0df3 2304 }
706246c7 2305 payload->payload_state = req_payload.payload_state;
ad7f8a1f
DA		 2306 }
2307 cur_slots += req_payload.num_slots;
263efde3 2308
cfe9f903 2309 if (put_port)
d0757afd 2310 drm_dp_mst_topology_put_port(port);
ad7f8a1f 2311 }
dfda0df3
DA		 2312
2313 for (i = 0; i < mgr->max_payloads; i++) {
706246c7
LP		 2314 if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL)
2315 continue;
dfda0df3 2316
706246c7
LP		 2317 DRM_DEBUG_KMS("removing payload %d\n", i);
2318 for (j = i; j < mgr->max_payloads - 1; j++) {
2319 mgr->payloads[j] = mgr->payloads[j + 1];
2320 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
2321
2322 if (mgr->proposed_vcpis[j] &&
2323 mgr->proposed_vcpis[j]->num_slots) {
2324 set_bit(j + 1, &mgr->payload_mask);
2325 } else {
2326 clear_bit(j + 1, &mgr->payload_mask);
2327 }
dfda0df3 2328 }
706246c7
LP		 2329
2330 memset(&mgr->payloads[mgr->max_payloads - 1], 0,
2331 sizeof(struct drm_dp_payload));
2332 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
2333 clear_bit(mgr->max_payloads, &mgr->payload_mask);
dfda0df3 2334 }
ad7f8a1f
DA		 2335 mutex_unlock(&mgr->payload_lock);
2336
2337 return 0;
2338}
2339EXPORT_SYMBOL(drm_dp_update_payload_part1);
2340
2341/**
2342 * drm_dp_update_payload_part2() - Execute payload update part 2
2343 * @mgr: manager to use.
2344 *
2345 * This iterates over all proposed virtual channels, and tries to
2346 * allocate space in the link for them. For 0->slots transitions,
2347 * this step writes the remote VC payload commands. For slots->0
2348 * this just resets some internal state.
2349 */
2350int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
2351{
2352 struct drm_dp_mst_port *port;
2353 int i;
7389ad4b 2354 int ret = 0;
ad7f8a1f
DA		 2355 mutex_lock(&mgr->payload_lock);
2356 for (i = 0; i < mgr->max_payloads; i++) {
2357
2358 if (!mgr->proposed_vcpis[i])
2359 continue;
2360
2361 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2362
2363 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
2364 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
dfda0df3 2365 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
ad7f8a1f 2366 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
dfda0df3 2367 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
ad7f8a1f
DA		 2368 }
2369 if (ret) {
2370 mutex_unlock(&mgr->payload_lock);
2371 return ret;
2372 }
2373 }
2374 mutex_unlock(&mgr->payload_lock);
2375 return 0;
2376}
2377EXPORT_SYMBOL(drm_dp_update_payload_part2);
2378
2379#if 0 /* unused as of yet */
2380static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
2381 struct drm_dp_mst_port *port,
2382 int offset, int size)
2383{
2384 int len;
2385 struct drm_dp_sideband_msg_tx *txmsg;
2386
2387 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2388 if (!txmsg)
2389 return -ENOMEM;
2390
2391 len = build_dpcd_read(txmsg, port->port_num, 0, 8);
2392 txmsg->dst = port->parent;
2393
2394 drm_dp_queue_down_tx(mgr, txmsg);
2395
2396 return 0;
2397}
2398#endif
2399
2400static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
2401 struct drm_dp_mst_port *port,
2402 int offset, int size, u8 *bytes)
2403{
2404 int len;
2405 int ret;
2406 struct drm_dp_sideband_msg_tx *txmsg;
2407 struct drm_dp_mst_branch *mstb;
2408
d0757afd 2409 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
ad7f8a1f
DA		 2410 if (!mstb)
2411 return -EINVAL;
2412
2413 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2414 if (!txmsg) {
2415 ret = -ENOMEM;
2416 goto fail_put;
2417 }
2418
2419 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
2420 txmsg->dst = mstb;
2421
2422 drm_dp_queue_down_tx(mgr, txmsg);
2423
2424 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2425 if (ret > 0) {
2426 if (txmsg->reply.reply_type == 1) {
2427 ret = -EINVAL;
2428 } else
2429 ret = 0;
2430 }
2431 kfree(txmsg);
2432fail_put:
d0757afd 2433 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 2434 return ret;
2435}
2436
2437static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
2438{
2439 struct drm_dp_sideband_msg_reply_body reply;
2440
a68d2437 2441 reply.reply_type = 0;
ad7f8a1f
DA		 2442 reply.req_type = req_type;
2443 drm_dp_encode_sideband_reply(&reply, msg);
2444 return 0;
2445}
2446
2447static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
2448 struct drm_dp_mst_branch *mstb,
2449 int req_type, int seqno, bool broadcast)
2450{
2451 struct drm_dp_sideband_msg_tx *txmsg;
2452
2453 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2454 if (!txmsg)
2455 return -ENOMEM;
2456
2457 txmsg->dst = mstb;
2458 txmsg->seqno = seqno;
2459 drm_dp_encode_up_ack_reply(txmsg, req_type);
2460
2461 mutex_lock(&mgr->qlock);
1f16ee7f
ML		 2462
2463 process_single_up_tx_qlock(mgr, txmsg);
2464
ad7f8a1f 2465 mutex_unlock(&mgr->qlock);
1f16ee7f
ML		 2466
2467 kfree(txmsg);
ad7f8a1f
DA		 2468 return 0;
2469}
2470
b853fdb3
CW		 2471static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
2472 int dp_link_count,
2473 int *out)
ad7f8a1f
DA		 2474{
2475 switch (dp_link_bw) {
b853fdb3
CW		 2476 default:
2477 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
2478 dp_link_bw, dp_link_count);
2479 return false;
2480
ad7f8a1f 2481 case DP_LINK_BW_1_62:
b853fdb3
CW		 2482 *out = 3 * dp_link_count;
2483 break;
ad7f8a1f 2484 case DP_LINK_BW_2_7:
b853fdb3
CW		 2485 *out = 5 * dp_link_count;
2486 break;
ad7f8a1f 2487 case DP_LINK_BW_5_4:
b853fdb3
CW		 2488 *out = 10 * dp_link_count;
2489 break;
e0bd878a
MN		 2490 case DP_LINK_BW_8_1:
2491 *out = 15 * dp_link_count;
2492 break;
ad7f8a1f 2493 }
b853fdb3 2494 return true;
ad7f8a1f
DA		 2495}
2496
2497/**
2498 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
2499 * @mgr: manager to set state for
2500 * @mst_state: true to enable MST on this connector - false to disable.
2501 *
2502 * This is called by the driver when it detects an MST capable device plugged
2503 * into a DP MST capable port, or when a DP MST capable device is unplugged.
2504 */
2505int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
2506{
2507 int ret = 0;
2508 struct drm_dp_mst_branch *mstb = NULL;
2509
2510 mutex_lock(&mgr->lock);
2511 if (mst_state == mgr->mst_state)
2512 goto out_unlock;
2513
2514 mgr->mst_state = mst_state;
2515 /* set the device into MST mode */
2516 if (mst_state) {
2517 WARN_ON(mgr->mst_primary);
2518
2519 /* get dpcd info */
2520 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2521 if (ret != DP_RECEIVER_CAP_SIZE) {
2522 DRM_DEBUG_KMS("failed to read DPCD\n");
2523 goto out_unlock;
2524 }
2525
b853fdb3
CW		 2526 if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2527 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2528 &mgr->pbn_div)) {
2529 ret = -EINVAL;
2530 goto out_unlock;
2531 }
2532
ad7f8a1f
DA		 2533 /* add initial branch device at LCT 1 */
2534 mstb = drm_dp_add_mst_branch_device(1, NULL);
2535 if (mstb == NULL) {
2536 ret = -ENOMEM;
2537 goto out_unlock;
2538 }
2539 mstb->mgr = mgr;
2540
2541 /* give this the main reference */
2542 mgr->mst_primary = mstb;
ebcc0e6b 2543 drm_dp_mst_topology_get_mstb(mgr->mst_primary);
ad7f8a1f 2544
c175cd16
AG		 2545 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2546 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2547 if (ret < 0) {
2548 goto out_unlock;
2549 }
2550
ad7f8a1f
DA		 2551 {
2552 struct drm_dp_payload reset_pay;
2553 reset_pay.start_slot = 0;
2554 reset_pay.num_slots = 0x3f;
2555 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2556 }
2557
ad7f8a1f
DA		 2558 queue_work(system_long_wq, &mgr->work);
2559
2560 ret = 0;
2561 } else {
2562 /* disable MST on the device */
2563 mstb = mgr->mst_primary;
2564 mgr->mst_primary = NULL;
2565 /* this can fail if the device is gone */
2566 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2567 ret = 0;
2568 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2569 mgr->payload_mask = 0;
2570 set_bit(0, &mgr->payload_mask);
dfda0df3 2571 mgr->vcpi_mask = 0;
ad7f8a1f
DA		 2572 }
2573
2574out_unlock:
2575 mutex_unlock(&mgr->lock);
2576 if (mstb)
d0757afd 2577 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 2578 return ret;
2579
2580}
2581EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2582
2583/**
2584 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2585 * @mgr: manager to suspend
2586 *
2587 * This function tells the MST device that we can't handle UP messages
2588 * anymore. This should stop it from sending any since we are suspended.
2589 */
2590void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2591{
2592 mutex_lock(&mgr->lock);
2593 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2594 DP_MST_EN | DP_UPSTREAM_IS_SRC);
2595 mutex_unlock(&mgr->lock);
274d8352
DA		 2596 flush_work(&mgr->work);
2597 flush_work(&mgr->destroy_connector_work);
ad7f8a1f
DA		 2598}
2599EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2600
2601/**
2602 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2603 * @mgr: manager to resume
2604 *
2605 * This will fetch DPCD and see if the device is still there,
2606 * if it is, it will rewrite the MSTM control bits, and return.
2607 *
2608 * if the device fails this returns -1, and the driver should do
2609 * a full MST reprobe, in case we were undocked.
2610 */
2611int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2612{
2613 int ret = 0;
2614
2615 mutex_lock(&mgr->lock);
2616
2617 if (mgr->mst_primary) {
2618 int sret;
1652fce6
L		 2619 u8 guid[16];
2620
ad7f8a1f
DA		 2621 sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2622 if (sret != DP_RECEIVER_CAP_SIZE) {
2623 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2624 ret = -1;
2625 goto out_unlock;
2626 }
2627
2628 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2629 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2630 if (ret < 0) {
2631 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2632 ret = -1;
2633 goto out_unlock;
2634 }
1652fce6
L		 2635
2636 /* Some hubs forget their guids after they resume */
2637 sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
2638 if (sret != 16) {
2639 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2640 ret = -1;
2641 goto out_unlock;
2642 }
2643 drm_dp_check_mstb_guid(mgr->mst_primary, guid);
2644
ad7f8a1f
DA		 2645 ret = 0;
2646 } else
2647 ret = -1;
2648
2649out_unlock:
2650 mutex_unlock(&mgr->lock);
2651 return ret;
2652}
2653EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2654
636c4c3e 2655static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
ad7f8a1f
DA		 2656{
2657 int len;
2658 u8 replyblock[32];
2659 int replylen, origlen, curreply;
2660 int ret;
2661 struct drm_dp_sideband_msg_rx *msg;
2662 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2663 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2664
2665 len = min(mgr->max_dpcd_transaction_bytes, 16);
2666 ret = drm_dp_dpcd_read(mgr->aux, basereg,
2667 replyblock, len);
2668 if (ret != len) {
2669 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
636c4c3e 2670 return false;
ad7f8a1f
DA		 2671 }
2672 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2673 if (!ret) {
2674 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
636c4c3e 2675 return false;
ad7f8a1f
DA		 2676 }
2677 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2678
2679 origlen = replylen;
2680 replylen -= len;
2681 curreply = len;
2682 while (replylen > 0) {
2683 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2684 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2685 replyblock, len);
2686 if (ret != len) {
448421b5
ID		 2687 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
2688 len, ret);
636c4c3e 2689 return false;
ad7f8a1f 2690 }
448421b5 2691
ad7f8a1f 2692 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
448421b5 2693 if (!ret) {
ad7f8a1f 2694 DRM_DEBUG_KMS("failed to build sideband msg\n");
636c4c3e 2695 return false;
448421b5
ID		 2696 }
2697
ad7f8a1f
DA		 2698 curreply += len;
2699 replylen -= len;
2700 }
636c4c3e 2701 return true;
ad7f8a1f
DA		 2702}
2703
2704static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2705{
2706 int ret = 0;
2707
636c4c3e
ID		 2708 if (!drm_dp_get_one_sb_msg(mgr, false)) {
2709 memset(&mgr->down_rep_recv, 0,
2710 sizeof(struct drm_dp_sideband_msg_rx));
2711 return 0;
2712 }
ad7f8a1f
DA		 2713
2714 if (mgr->down_rep_recv.have_eomt) {
2715 struct drm_dp_sideband_msg_tx *txmsg;
2716 struct drm_dp_mst_branch *mstb;
2717 int slot = -1;
2718 mstb = drm_dp_get_mst_branch_device(mgr,
2719 mgr->down_rep_recv.initial_hdr.lct,
2720 mgr->down_rep_recv.initial_hdr.rad);
2721
2722 if (!mstb) {
2723 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2724 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2725 return 0;
2726 }
2727
2728 /* find the message */
2729 slot = mgr->down_rep_recv.initial_hdr.seqno;
2730 mutex_lock(&mgr->qlock);
2731 txmsg = mstb->tx_slots[slot];
2732 /* remove from slots */
2733 mutex_unlock(&mgr->qlock);
2734
2735 if (!txmsg) {
2736 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2737 mstb,
2738 mgr->down_rep_recv.initial_hdr.seqno,
2739 mgr->down_rep_recv.initial_hdr.lct,
2740 mgr->down_rep_recv.initial_hdr.rad[0],
2741 mgr->down_rep_recv.msg[0]);
d0757afd 2742 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 2743 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2744 return 0;
2745 }
2746
2747 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2748 if (txmsg->reply.reply_type == 1) {
2749 DRM_DEBUG_KMS("Got NAK reply: req 0x%02x, reason 0x%02x, nak data 0x%02x\n", txmsg->reply.req_type, txmsg->reply.u.nak.reason, txmsg->reply.u.nak.nak_data);
2750 }
2751
2752 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
d0757afd 2753 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 2754
2755 mutex_lock(&mgr->qlock);
2756 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2757 mstb->tx_slots[slot] = NULL;
2758 mutex_unlock(&mgr->qlock);
2759
68e989dc 2760 wake_up_all(&mgr->tx_waitq);
ad7f8a1f
DA		 2761 }
2762 return ret;
2763}
2764
2765static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2766{
2767 int ret = 0;
636c4c3e
ID		 2768
2769 if (!drm_dp_get_one_sb_msg(mgr, true)) {
2770 memset(&mgr->up_req_recv, 0,
2771 sizeof(struct drm_dp_sideband_msg_rx));
2772 return 0;
2773 }
ad7f8a1f
DA		 2774
2775 if (mgr->up_req_recv.have_eomt) {
2776 struct drm_dp_sideband_msg_req_body msg;
bd934320 2777 struct drm_dp_mst_branch *mstb = NULL;
ad7f8a1f 2778 bool seqno;
bd934320
ML		 2779
2780 if (!mgr->up_req_recv.initial_hdr.broadcast) {
2781 mstb = drm_dp_get_mst_branch_device(mgr,
2782 mgr->up_req_recv.initial_hdr.lct,
2783 mgr->up_req_recv.initial_hdr.rad);
2784 if (!mstb) {
2785 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2786 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2787 return 0;
2788 }
ad7f8a1f
DA		 2789 }
2790
2791 seqno = mgr->up_req_recv.initial_hdr.seqno;
2792 drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2793
2794 if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
bd934320
ML		 2795 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2796
2797 if (!mstb)
2798 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2799
2800 if (!mstb) {
2801 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2802 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2803 return 0;
2804 }
2805
ad7f8a1f 2806 drm_dp_update_port(mstb, &msg.u.conn_stat);
5e93b820 2807
ad7f8a1f 2808 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 2809 drm_kms_helper_hotplug_event(mgr->dev);
8ae22cb4 2810
ad7f8a1f 2811 } else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
bd934320
ML		 2812 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2813 if (!mstb)
2814 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2815
2816 if (!mstb) {
2817 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2818 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2819 return 0;
2820 }
2821
ad7f8a1f
DA		 2822 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2823 }
2824
7f8b3987 2825 if (mstb)
d0757afd 2826 drm_dp_mst_topology_put_mstb(mstb);
7f8b3987 2827
ad7f8a1f
DA		 2828 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2829 }
2830 return ret;
2831}
2832
2833/**
2834 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2835 * @mgr: manager to notify irq for.
2836 * @esi: 4 bytes from SINK_COUNT_ESI
295ee853 2837 * @handled: whether the hpd interrupt was consumed or not
ad7f8a1f
DA		 2838 *
2839 * This should be called from the driver when it detects a short IRQ,
2840 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2841 * topology manager will process the sideband messages received as a result
2842 * of this.
2843 */
2844int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2845{
2846 int ret = 0;
2847 int sc;
2848 *handled = false;
2849 sc = esi[0] & 0x3f;
2850
2851 if (sc != mgr->sink_count) {
2852 mgr->sink_count = sc;
2853 *handled = true;
2854 }
2855
2856 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2857 ret = drm_dp_mst_handle_down_rep(mgr);
2858 *handled = true;
2859 }
2860
2861 if (esi[1] & DP_UP_REQ_MSG_RDY) {
2862 ret |= drm_dp_mst_handle_up_req(mgr);
2863 *handled = true;
2864 }
2865
2866 drm_dp_mst_kick_tx(mgr);
2867 return ret;
2868}
2869EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2870
2871/**
2872 * drm_dp_mst_detect_port() - get connection status for an MST port
132d49d7 2873 * @connector: DRM connector for this port
ad7f8a1f
DA		 2874 * @mgr: manager for this port
2875 * @port: unverified pointer to a port
2876 *
2877 * This returns the current connection state for a port. It validates the
2878 * port pointer still exists so the caller doesn't require a reference
2879 */
c6a0aed4
DA		 2880enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2881 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
ad7f8a1f
DA		 2882{
2883 enum drm_connector_status status = connector_status_disconnected;
2884
2885 /* we need to search for the port in the mgr in case its gone */
d0757afd 2886 port = drm_dp_mst_topology_get_port_validated(mgr, port);
ad7f8a1f
DA		 2887 if (!port)
2888 return connector_status_disconnected;
2889
2890 if (!port->ddps)
2891 goto out;
2892
2893 switch (port->pdt) {
2894 case DP_PEER_DEVICE_NONE:
2895 case DP_PEER_DEVICE_MST_BRANCHING:
2896 break;
2897
2898 case DP_PEER_DEVICE_SST_SINK:
2899 status = connector_status_connected;
8ae22cb4
DA		 2900 /* for logical ports - cache the EDID */
2901 if (port->port_num >= 8 && !port->cached_edid) {
2902 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2903 }
ad7f8a1f
DA		 2904 break;
2905 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2906 if (port->ldps)
2907 status = connector_status_connected;
2908 break;
2909 }
2910out:
d0757afd 2911 drm_dp_mst_topology_put_port(port);
ad7f8a1f
DA		 2912 return status;
2913}
2914EXPORT_SYMBOL(drm_dp_mst_detect_port);
2915
ef8f9bea
LY		 2916/**
2917 * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
2918 * @mgr: manager for this port
2919 * @port: unverified pointer to a port.
2920 *
2921 * This returns whether the port supports audio or not.
2922 */
2923bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
2924 struct drm_dp_mst_port *port)
2925{
2926 bool ret = false;
2927
d0757afd 2928 port = drm_dp_mst_topology_get_port_validated(mgr, port);
ef8f9bea
LY		 2929 if (!port)
2930 return ret;
2931 ret = port->has_audio;
d0757afd 2932 drm_dp_mst_topology_put_port(port);
ef8f9bea
LY		 2933 return ret;
2934}
2935EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
2936
ad7f8a1f
DA		 2937/**
2938 * drm_dp_mst_get_edid() - get EDID for an MST port
2939 * @connector: toplevel connector to get EDID for
2940 * @mgr: manager for this port
2941 * @port: unverified pointer to a port.
2942 *
2943 * This returns an EDID for the port connected to a connector,
2944 * It validates the pointer still exists so the caller doesn't require a
2945 * reference.
2946 */
2947struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2948{
2949 struct edid *edid = NULL;
2950
2951 /* we need to search for the port in the mgr in case its gone */
d0757afd 2952 port = drm_dp_mst_topology_get_port_validated(mgr, port);
ad7f8a1f
DA		 2953 if (!port)
2954 return NULL;
2955
c6a0aed4
DA		 2956 if (port->cached_edid)
2957 edid = drm_edid_duplicate(port->cached_edid);
8ae22cb4
DA		 2958 else {
2959 edid = drm_get_edid(connector, &port->aux.ddc);
97e14fbe 2960 drm_connector_set_tile_property(connector);
8ae22cb4 2961 }
ef8f9bea 2962 port->has_audio = drm_detect_monitor_audio(edid);
d0757afd 2963 drm_dp_mst_topology_put_port(port);
ad7f8a1f
DA		 2964 return edid;
2965}
2966EXPORT_SYMBOL(drm_dp_mst_get_edid);
2967
2968/**
e4b0c868 2969 * drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
ad7f8a1f
DA		 2970 * @mgr: manager to use
2971 * @pbn: payload bandwidth to convert into slots.
e4b0c868
LP		 2972 *
2973 * Calculate the number of VCPI slots that will be required for the given PBN
2974 * value. This function is deprecated, and should not be used in atomic
2975 * drivers.
2976 *
2977 * RETURNS:
2978 * The total slots required for this port, or error.
ad7f8a1f
DA		 2979 */
2980int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2981 int pbn)
2982{
2983 int num_slots;
2984
2985 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2986
feb2c3bc
PD		 2987 /* max. time slots - one slot for MTP header */
2988 if (num_slots > 63)
ad7f8a1f
DA		 2989 return -ENOSPC;
2990 return num_slots;
2991}
2992EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2993
2994static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
1e797f55 2995 struct drm_dp_vcpi *vcpi, int pbn, int slots)
ad7f8a1f 2996{
ad7f8a1f
DA		 2997 int ret;
2998
feb2c3bc 2999 /* max. time slots - one slot for MTP header */
1e797f55 3000 if (slots > 63)
ad7f8a1f
DA		 3001 return -ENOSPC;
3002
3003 vcpi->pbn = pbn;
1e797f55
PD		 3004 vcpi->aligned_pbn = slots * mgr->pbn_div;
3005 vcpi->num_slots = slots;
ad7f8a1f
DA		 3006
3007 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
3008 if (ret < 0)
3009 return ret;
3010 return 0;
3011}
3012
edb1ed1a 3013/**
eceae147 3014 * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
edb1ed1a
PD		 3015 * @state: global atomic state
3016 * @mgr: MST topology manager for the port
3017 * @port: port to find vcpi slots for
3018 * @pbn: bandwidth required for the mode in PBN
3019 *
eceae147
LP		 3020 * Allocates VCPI slots to @port, replacing any previous VCPI allocations it
3021 * may have had. Any atomic drivers which support MST must call this function
3022 * in their &drm_encoder_helper_funcs.atomic_check() callback to change the
3023 * current VCPI allocation for the new state, but only when
3024 * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set
3025 * to ensure compatibility with userspace applications that still use the
3026 * legacy modesetting UAPI.
3027 *
3028 * Allocations set by this function are not checked against the bandwidth
3029 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
3030 *
3031 * Additionally, it is OK to call this function multiple times on the same
3032 * @port as needed. It is not OK however, to call this function and
3033 * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
3034 *
3035 * See also:
3036 * drm_dp_atomic_release_vcpi_slots()
3037 * drm_dp_mst_atomic_check()
3038 *
3039 * Returns:
3040 * Total slots in the atomic state assigned for this port, or a negative error
3041 * code if the port no longer exists
edb1ed1a
PD		 3042 */
3043int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
3044 struct drm_dp_mst_topology_mgr *mgr,
3045 struct drm_dp_mst_port *port, int pbn)
3046{
3047 struct drm_dp_mst_topology_state *topology_state;
eceae147
LP		 3048 struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
3049 int prev_slots, req_slots, ret;
edb1ed1a
PD		 3050
3051 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
56a91c49
VS		 3052 if (IS_ERR(topology_state))
3053 return PTR_ERR(topology_state);
edb1ed1a 3054
d0757afd 3055 port = drm_dp_mst_topology_get_port_validated(mgr, port);
edb1ed1a
PD		 3056 if (port == NULL)
3057 return -EINVAL;
edb1ed1a 3058
eceae147
LP		 3059 /* Find the current allocation for this port, if any */
3060 list_for_each_entry(pos, &topology_state->vcpis, next) {
3061 if (pos->port == port) {
3062 vcpi = pos;
3063 prev_slots = vcpi->vcpi;
3064
3065 /*
3066 * This should never happen, unless the driver tries
3067 * releasing and allocating the same VCPI allocation,
3068 * which is an error
3069 */
3070 if (WARN_ON(!prev_slots)) {
3071 DRM_ERROR("cannot allocate and release VCPI on [MST PORT:%p] in the same state\n",
3072 port);
3073 return -EINVAL;
3074 }
3075
3076 break;
3077 }
edb1ed1a 3078 }
eceae147
LP		 3079 if (!vcpi)
3080 prev_slots = 0;
3081
3082 req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
3083
3084 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
3085 port->connector->base.id, port->connector->name,
3086 port, prev_slots, req_slots);
3087
3088 /* Add the new allocation to the state */
3089 if (!vcpi) {
3090 vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL);
3091 if (!vcpi) {
3092 ret = -ENOMEM;
3093 goto out;
3094 }
edb1ed1a 3095
eceae147
LP		 3096 drm_dp_mst_get_port_malloc(port);
3097 vcpi->port = port;
3098 list_add(&vcpi->next, &topology_state->vcpis);
3099 }
3100 vcpi->vcpi = req_slots;
edb1ed1a 3101
eceae147
LP		 3102 ret = req_slots;
3103out:
d0757afd 3104 drm_dp_mst_topology_put_port(port);
eceae147 3105 return ret;
edb1ed1a
PD		 3106}
3107EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
3108
3109/**
3110 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
3111 * @state: global atomic state
3112 * @mgr: MST topology manager for the port
eceae147 3113 * @port: The port to release the VCPI slots from
edb1ed1a 3114 *
eceae147
LP		 3115 * Releases any VCPI slots that have been allocated to a port in the atomic
3116 * state. Any atomic drivers which support MST must call this function in
3117 * their &drm_connector_helper_funcs.atomic_check() callback when the
3118 * connector will no longer have VCPI allocated (e.g. because it's CRTC was
3119 * removed) when it had VCPI allocated in the previous atomic state.
3120 *
3121 * It is OK to call this even if @port has been removed from the system.
3122 * Additionally, it is OK to call this function multiple times on the same
3123 * @port as needed. It is not OK however, to call this function and
3124 * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
3125 * phase.
3126 *
3127 * See also:
3128 * drm_dp_atomic_find_vcpi_slots()
3129 * drm_dp_mst_atomic_check()
3130 *
3131 * Returns:
3132 * 0 if all slots for this port were added back to
3133 * &drm_dp_mst_topology_state.avail_slots or negative error code
edb1ed1a
PD		 3134 */
3135int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
3136 struct drm_dp_mst_topology_mgr *mgr,
eceae147 3137 struct drm_dp_mst_port *port)
edb1ed1a
PD		 3138{
3139 struct drm_dp_mst_topology_state *topology_state;
eceae147
LP		 3140 struct drm_dp_vcpi_allocation *pos;
3141 bool found = false;
edb1ed1a
PD		 3142
3143 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
56a91c49
VS		 3144 if (IS_ERR(topology_state))
3145 return PTR_ERR(topology_state);
edb1ed1a 3146
eceae147
LP		 3147 list_for_each_entry(pos, &topology_state->vcpis, next) {
3148 if (pos->port == port) {
3149 found = true;
3150 break;
3151 }
3152 }
3153 if (WARN_ON(!found)) {
3154 DRM_ERROR("no VCPI for [MST PORT:%p] found in mst state %p\n",
3155 port, &topology_state->base);
3156 return -EINVAL;
3157 }
3158
3159 DRM_DEBUG_ATOMIC("[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi);
3160 if (pos->vcpi) {
3161 drm_dp_mst_put_port_malloc(port);
3162 pos->vcpi = 0;
3163 }
edb1ed1a
PD		 3164
3165 return 0;
3166}
3167EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
3168
ad7f8a1f
DA		 3169/**
3170 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
3171 * @mgr: manager for this port
3172 * @port: port to allocate a virtual channel for.
3173 * @pbn: payload bandwidth number to request
3174 * @slots: returned number of slots for this PBN.
3175 */
1e797f55
PD		 3176bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
3177 struct drm_dp_mst_port *port, int pbn, int slots)
ad7f8a1f
DA		 3178{
3179 int ret;
3180
d0757afd 3181 port = drm_dp_mst_topology_get_port_validated(mgr, port);
ad7f8a1f
DA		 3182 if (!port)
3183 return false;
3184
1e797f55
PD		 3185 if (slots < 0)
3186 return false;
3187
ad7f8a1f 3188 if (port->vcpi.vcpi > 0) {
e0ac7113
LP		 3189 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
3190 port->vcpi.vcpi, port->vcpi.pbn, pbn);
ad7f8a1f 3191 if (pbn == port->vcpi.pbn) {
d0757afd 3192 drm_dp_mst_topology_put_port(port);
ad7f8a1f
DA		 3193 return true;
3194 }
3195 }
3196
1e797f55 3197 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
ad7f8a1f 3198 if (ret) {
feb2c3bc 3199 DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
e0ac7113 3200 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
ad7f8a1f
DA		 3201 goto out;
3202 }
feb2c3bc 3203 DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
e0ac7113 3204 pbn, port->vcpi.num_slots);
ad7f8a1f 3205
cfe9f903
LP		 3206 /* Keep port allocated until it's payload has been removed */
3207 drm_dp_mst_get_port_malloc(port);
d0757afd 3208 drm_dp_mst_topology_put_port(port);
ad7f8a1f
DA		 3209 return true;
3210out:
3211 return false;
3212}
3213EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
3214
87f5942d
DA		 3215int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
3216{
3217 int slots = 0;
d0757afd 3218 port = drm_dp_mst_topology_get_port_validated(mgr, port);
87f5942d
DA		 3219 if (!port)
3220 return slots;
3221
3222 slots = port->vcpi.num_slots;
d0757afd 3223 drm_dp_mst_topology_put_port(port);
87f5942d
DA		 3224 return slots;
3225}
3226EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
3227
ad7f8a1f
DA		 3228/**
3229 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
3230 * @mgr: manager for this port
3231 * @port: unverified pointer to a port.
3232 *
3233 * This just resets the number of slots for the ports VCPI for later programming.
3234 */
3235void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
3236{
cfe9f903
LP		 3237 /*
3238 * A port with VCPI will remain allocated until it's VCPI is
3239 * released, no verified ref needed
3240 */
3241
ad7f8a1f 3242 port->vcpi.num_slots = 0;
ad7f8a1f
DA		 3243}
3244EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
3245
3246/**
3247 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
3248 * @mgr: manager for this port
3249 * @port: unverified port to deallocate vcpi for
3250 */
4afb8a26
LP		 3251void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
3252 struct drm_dp_mst_port *port)
ad7f8a1f 3253{
cfe9f903
LP		 3254 /*
3255 * A port with VCPI will remain allocated until it's VCPI is
3256 * released, no verified ref needed
3257 */
ad7f8a1f
DA		 3258
3259 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
3260 port->vcpi.num_slots = 0;
3261 port->vcpi.pbn = 0;
3262 port->vcpi.aligned_pbn = 0;
3263 port->vcpi.vcpi = 0;
cfe9f903 3264 drm_dp_mst_put_port_malloc(port);
ad7f8a1f
DA		 3265}
3266EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
3267
3268static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
3269 int id, struct drm_dp_payload *payload)
3270{
3271 u8 payload_alloc[3], status;
3272 int ret;
3273 int retries = 0;
3274
3275 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
3276 DP_PAYLOAD_TABLE_UPDATED);
3277
3278 payload_alloc[0] = id;
3279 payload_alloc[1] = payload->start_slot;
3280 payload_alloc[2] = payload->num_slots;
3281
3282 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
3283 if (ret != 3) {
3284 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
3285 goto fail;
3286 }
3287
3288retry:
3289 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
3290 if (ret < 0) {
3291 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
3292 goto fail;
3293 }
3294
3295 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
3296 retries++;
3297 if (retries < 20) {
3298 usleep_range(10000, 20000);
3299 goto retry;
3300 }
3301 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
3302 ret = -EINVAL;
3303 goto fail;
3304 }
3305 ret = 0;
3306fail:
3307 return ret;
3308}
3309
3310
3311/**
3312 * drm_dp_check_act_status() - Check ACT handled status.
3313 * @mgr: manager to use
3314 *
3315 * Check the payload status bits in the DPCD for ACT handled completion.
3316 */
3317int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
3318{
3319 u8 status;
3320 int ret;
3321 int count = 0;
3322
3323 do {
3324 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
3325
3326 if (ret < 0) {
3327 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
3328 goto fail;
3329 }
3330
3331 if (status & DP_PAYLOAD_ACT_HANDLED)
3332 break;
3333 count++;
3334 udelay(100);
3335
3336 } while (count < 30);
3337
3338 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
3339 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
3340 ret = -EINVAL;
3341 goto fail;
3342 }
3343 return 0;
3344fail:
3345 return ret;
3346}
3347EXPORT_SYMBOL(drm_dp_check_act_status);
3348
3349/**
3350 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
3351 * @clock: dot clock for the mode
3352 * @bpp: bpp for the mode.
3353 *
3354 * This uses the formula in the spec to calculate the PBN value for a mode.
3355 */
3356int drm_dp_calc_pbn_mode(int clock, int bpp)
3357{
a9ebb3e4
HW		 3358 u64 kbps;
3359 s64 peak_kbps;
3360 u32 numerator;
3361 u32 denominator;
3362
3363 kbps = clock * bpp;
3364
3365 /*
3366 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
3367 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
3368 * common multiplier to render an integer PBN for all link rate/lane
3369 * counts combinations
3370 * calculate
3371 * peak_kbps *= (1006/1000)
3372 * peak_kbps *= (64/54)
3373 * peak_kbps *= 8 convert to bytes
3374 */
3375
3376 numerator = 64 * 1006;
3377 denominator = 54 * 8 * 1000 * 1000;
3378
3379 kbps *= numerator;
3380 peak_kbps = drm_fixp_from_fraction(kbps, denominator);
3381
3382 return drm_fixp2int_ceil(peak_kbps);
ad7f8a1f
DA		 3383}
3384EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
3385
3386static int test_calc_pbn_mode(void)
3387{
3388 int ret;
3389 ret = drm_dp_calc_pbn_mode(154000, 30);
a9ebb3e4
HW		 3390 if (ret != 689) {
3391 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
3392 154000, 30, 689, ret);
ad7f8a1f 3393 return -EINVAL;
a9ebb3e4 3394 }
ad7f8a1f 3395 ret = drm_dp_calc_pbn_mode(234000, 30);
a9ebb3e4
HW		 3396 if (ret != 1047) {
3397 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
3398 234000, 30, 1047, ret);
ad7f8a1f 3399 return -EINVAL;
a9ebb3e4
HW		 3400 }
3401 ret = drm_dp_calc_pbn_mode(297000, 24);
3402 if (ret != 1063) {
3403 DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
3404 297000, 24, 1063, ret);
3405 return -EINVAL;
3406 }
ad7f8a1f
DA		 3407 return 0;
3408}
3409
3410/* we want to kick the TX after we've ack the up/down IRQs. */
3411static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
3412{
3413 queue_work(system_long_wq, &mgr->tx_work);
3414}
3415
3416static void drm_dp_mst_dump_mstb(struct seq_file *m,
3417 struct drm_dp_mst_branch *mstb)
3418{
3419 struct drm_dp_mst_port *port;
3420 int tabs = mstb->lct;
3421 char prefix[10];
3422 int i;
3423
3424 for (i = 0; i < tabs; i++)
3425 prefix[i] = '\t';
3426 prefix[i] = '\0';
3427
3428 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
3429 list_for_each_entry(port, &mstb->ports, next) {
51108f25 3430 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		 3431 if (port->mstb)
3432 drm_dp_mst_dump_mstb(m, port->mstb);
3433 }
3434}
3435
7056a2bc
AS		 3436#define DP_PAYLOAD_TABLE_SIZE 64
3437
ad7f8a1f
DA		 3438static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
3439 char *buf)
3440{
ad7f8a1f 3441 int i;
46466b0d 3442
7056a2bc 3443 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
46466b0d
JP		 3444 if (drm_dp_dpcd_read(mgr->aux,
3445 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
3446 &buf[i], 16) != 16)
3447 return false;
ad7f8a1f 3448 }
46466b0d 3449 return true;
ad7f8a1f
DA		 3450}
3451
51108f25
JB		 3452static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
3453 struct drm_dp_mst_port *port, char *name,
3454 int namelen)
3455{
3456 struct edid *mst_edid;
3457
3458 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
3459 drm_edid_get_monitor_name(mst_edid, name, namelen);
3460}
3461
ad7f8a1f
DA		 3462/**
3463 * drm_dp_mst_dump_topology(): dump topology to seq file.
3464 * @m: seq_file to dump output to
3465 * @mgr: manager to dump current topology for.
3466 *
3467 * helper to dump MST topology to a seq file for debugfs.
3468 */
3469void drm_dp_mst_dump_topology(struct seq_file *m,
3470 struct drm_dp_mst_topology_mgr *mgr)
3471{
3472 int i;
3473 struct drm_dp_mst_port *port;
51108f25 3474
ad7f8a1f
DA		 3475 mutex_lock(&mgr->lock);
3476 if (mgr->mst_primary)
3477 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
3478
3479 /* dump VCPIs */
3480 mutex_unlock(&mgr->lock);
3481
3482 mutex_lock(&mgr->payload_lock);
51108f25
JB		 3483 seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
3484 mgr->max_payloads);
ad7f8a1f
DA		 3485
3486 for (i = 0; i < mgr->max_payloads; i++) {
3487 if (mgr->proposed_vcpis[i]) {
51108f25
JB		 3488 char name[14];
3489
ad7f8a1f 3490 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
51108f25
JB		 3491 fetch_monitor_name(mgr, port, name, sizeof(name));
3492 seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
3493 port->port_num, port->vcpi.vcpi,
3494 port->vcpi.num_slots,
3495 (*name != 0) ? name : "Unknown");
ad7f8a1f 3496 } else
51108f25 3497 seq_printf(m, "vcpi %d:unused\n", i);
ad7f8a1f
DA		 3498 }
3499 for (i = 0; i < mgr->max_payloads; i++) {
3500 seq_printf(m, "payload %d: %d, %d, %d\n",
3501 i,
3502 mgr->payloads[i].payload_state,
3503 mgr->payloads[i].start_slot,
3504 mgr->payloads[i].num_slots);
3505
3506
3507 }
3508 mutex_unlock(&mgr->payload_lock);
3509
3510 mutex_lock(&mgr->lock);
3511 if (mgr->mst_primary) {
7056a2bc 3512 u8 buf[DP_PAYLOAD_TABLE_SIZE];
ad7f8a1f 3513 int ret;
46466b0d 3514
ad7f8a1f 3515 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
46466b0d 3516 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
ad7f8a1f 3517 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
46466b0d 3518 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
ad7f8a1f 3519 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
46466b0d 3520 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
ad7f8a1f 3521
44790462
DA		 3522 /* dump the standard OUI branch header */
3523 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
46466b0d 3524 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
51108f25 3525 for (i = 0x3; i < 0x8 && buf[i]; i++)
44790462 3526 seq_printf(m, "%c", buf[i]);
46466b0d
JP		 3527 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
3528 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
3529 if (dump_dp_payload_table(mgr, buf))
7056a2bc 3530 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
ad7f8a1f
DA		 3531 }
3532
3533 mutex_unlock(&mgr->lock);
3534
3535}
3536EXPORT_SYMBOL(drm_dp_mst_dump_topology);
3537
3538static void drm_dp_tx_work(struct work_struct *work)
3539{
3540 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
3541
3542 mutex_lock(&mgr->qlock);
cb021a3e 3543 if (!list_empty(&mgr->tx_msg_downq))
ad7f8a1f
DA		 3544 process_single_down_tx_qlock(mgr);
3545 mutex_unlock(&mgr->qlock);
3546}
3547
6b8eeca6
DA		 3548static void drm_dp_destroy_connector_work(struct work_struct *work)
3549{
3550 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
4772ff03 3551 struct drm_dp_mst_port *port;
df4839fd 3552 bool send_hotplug = false;
6b8eeca6
DA		 3553 /*
3554 * Not a regular list traverse as we have to drop the destroy
3555 * connector lock before destroying the connector, to avoid AB->BA
3556 * ordering between this lock and the config mutex.
3557 */
3558 for (;;) {
3559 mutex_lock(&mgr->destroy_connector_lock);
4772ff03
ML		 3560 port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
3561 if (!port) {
6b8eeca6
DA		 3562 mutex_unlock(&mgr->destroy_connector_lock);
3563 break;
3564 }
4772ff03 3565 list_del(&port->next);
6b8eeca6
DA		 3566 mutex_unlock(&mgr->destroy_connector_lock);
3567
91a25e46
ML		 3568 INIT_LIST_HEAD(&port->next);
3569
4772ff03
ML		 3570 mgr->cbs->destroy_connector(mgr, port->connector);
3571
3572 drm_dp_port_teardown_pdt(port, port->pdt);
36e3fa6a 3573 port->pdt = DP_PEER_DEVICE_NONE;
4772ff03 3574
ebcc0e6b 3575 drm_dp_mst_put_port_malloc(port);
df4839fd 3576 send_hotplug = true;
6b8eeca6 3577 }
df4839fd 3578 if (send_hotplug)
16bff572 3579 drm_kms_helper_hotplug_event(mgr->dev);
6b8eeca6
DA		 3580}
3581
a4370c77
VS		 3582static struct drm_private_state *
3583drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
3f3353b7 3584{
eceae147
LP		 3585 struct drm_dp_mst_topology_state *state, *old_state =
3586 to_dp_mst_topology_state(obj->state);
3587 struct drm_dp_vcpi_allocation *pos, *vcpi;
3f3353b7 3588
eceae147 3589 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
a4370c77 3590 if (!state)
3f3353b7
PD		 3591 return NULL;
3592
a4370c77 3593 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
3f3353b7 3594
eceae147
LP		 3595 INIT_LIST_HEAD(&state->vcpis);
3596
3597 list_for_each_entry(pos, &old_state->vcpis, next) {
3598 /* Prune leftover freed VCPI allocations */
3599 if (!pos->vcpi)
3600 continue;
3601
3602 vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL);
3603 if (!vcpi)
3604 goto fail;
3605
3606 drm_dp_mst_get_port_malloc(vcpi->port);
3607 list_add(&vcpi->next, &state->vcpis);
3608 }
3609
a4370c77 3610 return &state->base;
eceae147
LP		 3611
3612fail:
3613 list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) {
3614 drm_dp_mst_put_port_malloc(pos->port);
3615 kfree(pos);
3616 }
3617 kfree(state);
3618
3619 return NULL;
3f3353b7
PD		 3620}
3621
a4370c77
VS		 3622static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
3623 struct drm_private_state *state)
3f3353b7 3624{
a4370c77
VS		 3625 struct drm_dp_mst_topology_state *mst_state =
3626 to_dp_mst_topology_state(state);
eceae147
LP		 3627 struct drm_dp_vcpi_allocation *pos, *tmp;
3628
3629 list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) {
3630 /* We only keep references to ports with non-zero VCPIs */
3631 if (pos->vcpi)
3632 drm_dp_mst_put_port_malloc(pos->port);
3633 kfree(pos);
3634 }
a4370c77
VS		 3635
3636 kfree(mst_state);
3f3353b7
PD		 3637}
3638
eceae147
LP		 3639static inline int
3640drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr,
3641 struct drm_dp_mst_topology_state *mst_state)
3642{
3643 struct drm_dp_vcpi_allocation *vcpi;
5e187a01 3644 int avail_slots = 63, payload_count = 0;
eceae147
LP		 3645
3646 list_for_each_entry(vcpi, &mst_state->vcpis, next) {
3647 /* Releasing VCPI is always OK-even if the port is gone */
3648 if (!vcpi->vcpi) {
3649 DRM_DEBUG_ATOMIC("[MST PORT:%p] releases all VCPI slots\n",
3650 vcpi->port);
3651 continue;
3652 }
3653
3654 DRM_DEBUG_ATOMIC("[MST PORT:%p] requires %d vcpi slots\n",
3655 vcpi->port, vcpi->vcpi);
3656
3657 avail_slots -= vcpi->vcpi;
3658 if (avail_slots < 0) {
3659 DRM_DEBUG_ATOMIC("[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n",
3660 vcpi->port, mst_state,
3661 avail_slots + vcpi->vcpi);
3662 return -ENOSPC;
3663 }
5e187a01
LP		 3664
3665 if (++payload_count > mgr->max_payloads) {
3666 DRM_DEBUG_ATOMIC("[MST MGR:%p] state %p has too many payloads (max=%d)\n",
3667 mgr, mst_state, mgr->max_payloads);
3668 return -EINVAL;
3669 }
eceae147
LP		 3670 }
3671 DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
3672 mgr, mst_state, avail_slots,
3673 63 - avail_slots);
3674
3675 return 0;
3676}
3677
3678/**
3679 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
3680 * atomic update is valid
3681 * @state: Pointer to the new &struct drm_dp_mst_topology_state
3682 *
3683 * Checks the given topology state for an atomic update to ensure that it's
3684 * valid. This includes checking whether there's enough bandwidth to support
3685 * the new VCPI allocations in the atomic update.
3686 *
3687 * Any atomic drivers supporting DP MST must make sure to call this after
3688 * checking the rest of their state in their
3689 * &drm_mode_config_funcs.atomic_check() callback.
3690 *
3691 * See also:
3692 * drm_dp_atomic_find_vcpi_slots()
3693 * drm_dp_atomic_release_vcpi_slots()
3694 *
3695 * Returns:
3696 *
3697 * 0 if the new state is valid, negative error code otherwise.
3698 */
3699int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
3700{
3701 struct drm_dp_mst_topology_mgr *mgr;
3702 struct drm_dp_mst_topology_state *mst_state;
3703 int i, ret = 0;
3704
3705 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
3706 ret = drm_dp_mst_atomic_check_topology_state(mgr, mst_state);
3707 if (ret)
3708 break;
3709 }
3710
3711 return ret;
3712}
3713EXPORT_SYMBOL(drm_dp_mst_atomic_check);
3714
bea5c38f 3715const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
a4370c77
VS		 3716 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
3717 .atomic_destroy_state = drm_dp_mst_destroy_state,
3f3353b7 3718};
bea5c38f 3719EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
3f3353b7
PD		 3720
3721/**
3722 * drm_atomic_get_mst_topology_state: get MST topology state
3723 *
3724 * @state: global atomic state
3725 * @mgr: MST topology manager, also the private object in this case
3726 *
3727 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
3728 * state vtable so that the private object state returned is that of a MST
3729 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
3730 * to care of the locking, so warn if don't hold the connection_mutex.
3731 *
3732 * RETURNS:
3733 *
3734 * The MST topology state or error pointer.
3735 */
3736struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
3737 struct drm_dp_mst_topology_mgr *mgr)
3738{
3739 struct drm_device *dev = mgr->dev;
3740
3741 WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
a4370c77 3742 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
3f3353b7
PD		 3743}
3744EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
3745
ad7f8a1f
DA		 3746/**
3747 * drm_dp_mst_topology_mgr_init - initialise a topology manager
3748 * @mgr: manager struct to initialise
3749 * @dev: device providing this structure - for i2c addition.
3750 * @aux: DP helper aux channel to talk to this device
3751 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
3752 * @max_payloads: maximum number of payloads this GPU can source
3753 * @conn_base_id: the connector object ID the MST device is connected to.
3754 *
3755 * Return 0 for success, or negative error code on failure
3756 */
3757int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
7b0a89a6 3758 struct drm_device *dev, struct drm_dp_aux *aux,
ad7f8a1f
DA		 3759 int max_dpcd_transaction_bytes,
3760 int max_payloads, int conn_base_id)
3761{
a4370c77
VS		 3762 struct drm_dp_mst_topology_state *mst_state;
3763
ad7f8a1f
DA		 3764 mutex_init(&mgr->lock);
3765 mutex_init(&mgr->qlock);
3766 mutex_init(&mgr->payload_lock);
6b8eeca6 3767 mutex_init(&mgr->destroy_connector_lock);
ad7f8a1f 3768 INIT_LIST_HEAD(&mgr->tx_msg_downq);
6b8eeca6 3769 INIT_LIST_HEAD(&mgr->destroy_connector_list);
ad7f8a1f
DA		 3770 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
3771 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
6b8eeca6 3772 INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
ad7f8a1f
DA		 3773 init_waitqueue_head(&mgr->tx_waitq);
3774 mgr->dev = dev;
3775 mgr->aux = aux;
3776 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
3777 mgr->max_payloads = max_payloads;
3778 mgr->conn_base_id = conn_base_id;
4d6a10da
ID		 3779 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
3780 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
3781 return -EINVAL;
ad7f8a1f
DA		 3782 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
3783 if (!mgr->payloads)
3784 return -ENOMEM;
3785 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
3786 if (!mgr->proposed_vcpis)
3787 return -ENOMEM;
3788 set_bit(0, &mgr->payload_mask);
441388a8
ID		 3789 if (test_calc_pbn_mode() < 0)
3790 DRM_ERROR("MST PBN self-test failed\n");
3791
a4370c77
VS		 3792 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
3793 if (mst_state == NULL)
3f3353b7 3794 return -ENOMEM;
a4370c77
VS		 3795
3796 mst_state->mgr = mgr;
eceae147 3797 INIT_LIST_HEAD(&mst_state->vcpis);
a4370c77 3798
b962a120 3799 drm_atomic_private_obj_init(dev, &mgr->base,
a4370c77 3800 &mst_state->base,
bea5c38f 3801 &drm_dp_mst_topology_state_funcs);
3f3353b7 3802
ad7f8a1f
DA		 3803 return 0;
3804}
3805EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
3806
3807/**
3808 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
3809 * @mgr: manager to destroy
3810 */
3811void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
3812{
f536e00c 3813 drm_dp_mst_topology_mgr_set_mst(mgr, false);
274d8352 3814 flush_work(&mgr->work);
6b8eeca6 3815 flush_work(&mgr->destroy_connector_work);
ad7f8a1f
DA		 3816 mutex_lock(&mgr->payload_lock);
3817 kfree(mgr->payloads);
3818 mgr->payloads = NULL;
3819 kfree(mgr->proposed_vcpis);
3820 mgr->proposed_vcpis = NULL;
3821 mutex_unlock(&mgr->payload_lock);
3822 mgr->dev = NULL;
3823 mgr->aux = NULL;
a4370c77 3824 drm_atomic_private_obj_fini(&mgr->base);
3f3353b7 3825 mgr->funcs = NULL;
ad7f8a1f
DA		 3826}
3827EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
3828
cb8ce711
VS		 3829static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
3830{
3831 int i;
3832
3833 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
3834 return false;
3835
3836 for (i = 0; i < num - 1; i++) {
3837 if (msgs[i].flags & I2C_M_RD ||
3838 msgs[i].len > 0xff)
3839 return false;
3840 }
3841
3842 return msgs[num - 1].flags & I2C_M_RD &&
3843 msgs[num - 1].len <= 0xff;
3844}
3845
ad7f8a1f
DA		 3846/* I2C device */
3847static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
3848 int num)
3849{
3850 struct drm_dp_aux *aux = adapter->algo_data;
3851 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
3852 struct drm_dp_mst_branch *mstb;
3853 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
3854 unsigned int i;
ad7f8a1f
DA		 3855 struct drm_dp_sideband_msg_req_body msg;
3856 struct drm_dp_sideband_msg_tx *txmsg = NULL;
3857 int ret;
3858
d0757afd 3859 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
ad7f8a1f
DA		 3860 if (!mstb)
3861 return -EREMOTEIO;
3862
cb8ce711 3863 if (!remote_i2c_read_ok(msgs, num)) {
ad7f8a1f
DA		 3864 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
3865 ret = -EIO;
3866 goto out;
3867 }
3868
ae491542 3869 memset(&msg, 0, sizeof(msg));
ad7f8a1f
DA		 3870 msg.req_type = DP_REMOTE_I2C_READ;
3871 msg.u.i2c_read.num_transactions = num - 1;
3872 msg.u.i2c_read.port_number = port->port_num;
3873 for (i = 0; i < num - 1; i++) {
3874 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
3875 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
3876 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
c978ae9b 3877 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
ad7f8a1f
DA		 3878 }
3879 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
3880 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
3881
3882 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3883 if (!txmsg) {
3884 ret = -ENOMEM;
3885 goto out;
3886 }
3887
3888 txmsg->dst = mstb;
3889 drm_dp_encode_sideband_req(&msg, txmsg);
3890
3891 drm_dp_queue_down_tx(mgr, txmsg);
3892
3893 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3894 if (ret > 0) {
3895
3896 if (txmsg->reply.reply_type == 1) { /* got a NAK back */
3897 ret = -EREMOTEIO;
3898 goto out;
3899 }
3900 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
3901 ret = -EIO;
3902 goto out;
3903 }
3904 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
3905 ret = num;
3906 }
3907out:
3908 kfree(txmsg);
d0757afd 3909 drm_dp_mst_topology_put_mstb(mstb);
ad7f8a1f
DA		 3910 return ret;
3911}
3912
3913static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
3914{
3915 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
3916 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
3917 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
3918 I2C_FUNC_10BIT_ADDR;
3919}
3920
3921static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
3922 .functionality = drm_dp_mst_i2c_functionality,
3923 .master_xfer = drm_dp_mst_i2c_xfer,
3924};
3925
3926/**
3927 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
3928 * @aux: DisplayPort AUX channel
3929 *
3930 * Returns 0 on success or a negative error code on failure.
3931 */
3932static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
3933{
3934 aux->ddc.algo = &drm_dp_mst_i2c_algo;
3935 aux->ddc.algo_data = aux;
3936 aux->ddc.retries = 3;
3937
3938 aux->ddc.class = I2C_CLASS_DDC;
3939 aux->ddc.owner = THIS_MODULE;
3940 aux->ddc.dev.parent = aux->dev;
3941 aux->ddc.dev.of_node = aux->dev->of_node;
3942
3943 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
3944 sizeof(aux->ddc.name));
3945
3946 return i2c_add_adapter(&aux->ddc);
3947}
3948
3949/**
3950 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
3951 * @aux: DisplayPort AUX channel
3952 */
3953static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3954{
3955 i2c_del_adapter(&aux->ddc);
3956}
Linux 6.x block layer and io_uring tree(s)