1 /* $NetBSD: drm_dp_mst_topology.c,v 1.12 2022/08/22 18:30:50 riastradh Exp $ */
2
3 /*
4 * Copyright © 2014 Red Hat
5 *
6 * Permission to use, copy, modify, distribute, and sell this software and its
7 * documentation for any purpose is hereby granted without fee, provided that
8 * the above copyright notice appear in all copies and that both that copyright
9 * notice and this permission notice appear in supporting documentation, and
10 * that the name of the copyright holders not be used in advertising or
11 * publicity pertaining to distribution of the software without specific,
12 * written prior permission. The copyright holders make no representations
13 * about the suitability of this software for any purpose. It is provided "as
14 * is" without express or implied warranty.
15 *
16 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
17 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
18 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
19 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
20 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
21 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
22 * OF THIS SOFTWARE.
23 */
24
25 #include <sys/cdefs.h>
26 __KERNEL_RCSID(0, "$NetBSD: drm_dp_mst_topology.c,v 1.12 2022/08/22 18:30:50 riastradh Exp $");
27
28 #include <linux/delay.h>
29 #include <linux/errno.h>
30 #include <linux/i2c.h>
31 #include <linux/init.h>
32 #include <linux/kernel.h>
33 #include <linux/sched.h>
34 #include <linux/seq_file.h>
35
36 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
37 #include <linux/stacktrace.h>
38 #include <linux/sort.h>
39 #include <linux/timekeeping.h>
40 #include <linux/math64.h>
41 #endif
42
43 #include <drm/drm_atomic.h>
44 #include <drm/drm_atomic_helper.h>
45 #include <drm/drm_dp_mst_helper.h>
46 #include <drm/drm_drv.h>
47 #include <drm/drm_print.h>
48 #include <drm/drm_probe_helper.h>
49
50 #include "drm_crtc_helper_internal.h"
51 #include "drm_dp_mst_topology_internal.h"
52
53 #include <linux/nbsd-namespace.h>
54
55 /**
56 * DOC: dp mst helper
57 *
58 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
59 * protocol. The helpers contain a topology manager and bandwidth manager.
60 * The helpers encapsulate the sending and received of sideband msgs.
61 */
62 struct drm_dp_pending_up_req {
63 struct drm_dp_sideband_msg_hdr hdr;
64 struct drm_dp_sideband_msg_req_body msg;
65 struct list_head next;
66 };
67
68 #if IS_ENABLED(CONFIG_DEBUG_FS)
69 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
70 char *buf);
71 #endif
72
73 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
74
75 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
76 int id,
77 struct drm_dp_payload *payload);
78
79 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
80 struct drm_dp_mst_port *port,
81 int offset, int size, u8 *bytes);
82 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
83 struct drm_dp_mst_port *port,
84 int offset, int size, u8 *bytes);
85
86 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
87 struct drm_dp_mst_branch *mstb);
88
89 static void
90 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
91 struct drm_dp_mst_branch *mstb);
92
93 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
94 struct drm_dp_mst_branch *mstb,
95 struct drm_dp_mst_port *port);
96 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
97 u8 *guid);
98
99 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
100 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
101 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
102
103 #define DBG_PREFIX "[dp_mst]"
104
105 #define DP_STR(x) [DP_ ## x] = #x
106
drm_dp_mst_req_type_str(u8 req_type)107 static const char *drm_dp_mst_req_type_str(u8 req_type)
108 {
109 static const char * const req_type_str[] = {
110 DP_STR(GET_MSG_TRANSACTION_VERSION),
111 DP_STR(LINK_ADDRESS),
112 DP_STR(CONNECTION_STATUS_NOTIFY),
113 DP_STR(ENUM_PATH_RESOURCES),
114 DP_STR(ALLOCATE_PAYLOAD),
115 DP_STR(QUERY_PAYLOAD),
116 DP_STR(RESOURCE_STATUS_NOTIFY),
117 DP_STR(CLEAR_PAYLOAD_ID_TABLE),
118 DP_STR(REMOTE_DPCD_READ),
119 DP_STR(REMOTE_DPCD_WRITE),
120 DP_STR(REMOTE_I2C_READ),
121 DP_STR(REMOTE_I2C_WRITE),
122 DP_STR(POWER_UP_PHY),
123 DP_STR(POWER_DOWN_PHY),
124 DP_STR(SINK_EVENT_NOTIFY),
125 DP_STR(QUERY_STREAM_ENC_STATUS),
126 };
127
128 if (req_type >= ARRAY_SIZE(req_type_str) ||
129 !req_type_str[req_type])
130 return "unknown";
131
132 return req_type_str[req_type];
133 }
134
135 #undef DP_STR
136 #define DP_STR(x) [DP_NAK_ ## x] = #x
137
drm_dp_mst_nak_reason_str(u8 nak_reason)138 static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
139 {
140 static const char * const nak_reason_str[] = {
141 DP_STR(WRITE_FAILURE),
142 DP_STR(INVALID_READ),
143 DP_STR(CRC_FAILURE),
144 DP_STR(BAD_PARAM),
145 DP_STR(DEFER),
146 DP_STR(LINK_FAILURE),
147 DP_STR(NO_RESOURCES),
148 DP_STR(DPCD_FAIL),
149 DP_STR(I2C_NAK),
150 DP_STR(ALLOCATE_FAIL),
151 };
152
153 if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
154 !nak_reason_str[nak_reason])
155 return "unknown";
156
157 return nak_reason_str[nak_reason];
158 }
159
160 #undef DP_STR
161 #define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x
162
drm_dp_mst_sideband_tx_state_str(int state)163 static const char *drm_dp_mst_sideband_tx_state_str(int state)
164 {
165 static const char * const sideband_reason_str[] = {
166 DP_STR(QUEUED),
167 DP_STR(START_SEND),
168 DP_STR(SENT),
169 DP_STR(RX),
170 DP_STR(TIMEOUT),
171 };
172
173 if (state >= ARRAY_SIZE(sideband_reason_str) ||
174 !sideband_reason_str[state])
175 return "unknown";
176
177 return sideband_reason_str[state];
178 }
179
180 static int
drm_dp_mst_rad_to_str(const u8 rad[8],u8 lct,char * out,size_t len)181 drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len)
182 {
183 int i;
184 u8 unpacked_rad[16];
185
186 for (i = 0; i < lct; i++) {
187 if (i % 2)
188 unpacked_rad[i] = rad[i / 2] >> 4;
189 else
190 unpacked_rad[i] = rad[i / 2] & BIT_MASK(4);
191 }
192
193 /* TODO: Eventually add something to printk so we can format the rad
194 * like this: 1.2.3
195 */
196 return snprintf(out, len, "%*phC", lct, unpacked_rad);
197 }
198
199 /* sideband msg handling */
drm_dp_msg_header_crc4(const uint8_t * data,size_t num_nibbles)200 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
201 {
202 u8 bitmask = 0x80;
203 u8 bitshift = 7;
204 u8 array_index = 0;
205 int number_of_bits = num_nibbles * 4;
206 u8 remainder = 0;
207
208 while (number_of_bits != 0) {
209 number_of_bits--;
210 remainder <<= 1;
211 remainder |= (data[array_index] & bitmask) >> bitshift;
212 bitmask >>= 1;
213 bitshift--;
214 if (bitmask == 0) {
215 bitmask = 0x80;
216 bitshift = 7;
217 array_index++;
218 }
219 if ((remainder & 0x10) == 0x10)
220 remainder ^= 0x13;
221 }
222
223 number_of_bits = 4;
224 while (number_of_bits != 0) {
225 number_of_bits--;
226 remainder <<= 1;
227 if ((remainder & 0x10) != 0)
228 remainder ^= 0x13;
229 }
230
231 return remainder;
232 }
233
drm_dp_msg_data_crc4(const uint8_t * data,u8 number_of_bytes)234 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
235 {
236 u8 bitmask = 0x80;
237 u8 bitshift = 7;
238 u8 array_index = 0;
239 int number_of_bits = number_of_bytes * 8;
240 u16 remainder = 0;
241
242 while (number_of_bits != 0) {
243 number_of_bits--;
244 remainder <<= 1;
245 remainder |= (data[array_index] & bitmask) >> bitshift;
246 bitmask >>= 1;
247 bitshift--;
248 if (bitmask == 0) {
249 bitmask = 0x80;
250 bitshift = 7;
251 array_index++;
252 }
253 if ((remainder & 0x100) == 0x100)
254 remainder ^= 0xd5;
255 }
256
257 number_of_bits = 8;
258 while (number_of_bits != 0) {
259 number_of_bits--;
260 remainder <<= 1;
261 if ((remainder & 0x100) != 0)
262 remainder ^= 0xd5;
263 }
264
265 return remainder & 0xff;
266 }
drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr * hdr)267 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
268 {
269 u8 size = 3;
270 size += (hdr->lct / 2);
271 return size;
272 }
273
drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr * hdr,u8 * buf,int * len)274 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
275 u8 *buf, int *len)
276 {
277 int idx = 0;
278 int i;
279 u8 crc4;
280 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
281 for (i = 0; i < (hdr->lct / 2); i++)
282 buf[idx++] = hdr->rad[i];
283 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
284 (hdr->msg_len & 0x3f);
285 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
286
287 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
288 buf[idx - 1] |= (crc4 & 0xf);
289
290 *len = idx;
291 }
292
drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr * hdr,u8 * buf,int buflen,u8 * hdrlen)293 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
294 u8 *buf, int buflen, u8 *hdrlen)
295 {
296 u8 crc4;
297 u8 len;
298 int i;
299 u8 idx;
300 if (buf[0] == 0)
301 return false;
302 len = 3;
303 len += ((buf[0] & 0xf0) >> 4) / 2;
304 if (len > buflen)
305 return false;
306 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
307
308 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
309 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
310 return false;
311 }
312
313 hdr->lct = (buf[0] & 0xf0) >> 4;
314 hdr->lcr = (buf[0] & 0xf);
315 idx = 1;
316 for (i = 0; i < (hdr->lct / 2); i++)
317 hdr->rad[i] = buf[idx++];
318 hdr->broadcast = (buf[idx] >> 7) & 0x1;
319 hdr->path_msg = (buf[idx] >> 6) & 0x1;
320 hdr->msg_len = buf[idx] & 0x3f;
321 idx++;
322 hdr->somt = (buf[idx] >> 7) & 0x1;
323 hdr->eomt = (buf[idx] >> 6) & 0x1;
324 hdr->seqno = (buf[idx] >> 4) & 0x1;
325 idx++;
326 *hdrlen = idx;
327 return true;
328 }
329
330 static void
drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body * req,struct drm_dp_sideband_msg_tx * raw)331 drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
332 struct drm_dp_sideband_msg_tx *raw)
333 {
334 int idx = 0;
335 int i;
336 u8 *buf = raw->msg;
337 buf[idx++] = req->req_type & 0x7f;
338
339 switch (req->req_type) {
340 case DP_ENUM_PATH_RESOURCES:
341 case DP_POWER_DOWN_PHY:
342 case DP_POWER_UP_PHY:
343 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
344 idx++;
345 break;
346 case DP_ALLOCATE_PAYLOAD:
347 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
348 (req->u.allocate_payload.number_sdp_streams & 0xf);
349 idx++;
350 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
351 idx++;
352 buf[idx] = (req->u.allocate_payload.pbn >> 8);
353 idx++;
354 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
355 idx++;
356 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
357 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
358 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
359 idx++;
360 }
361 if (req->u.allocate_payload.number_sdp_streams & 1) {
362 i = req->u.allocate_payload.number_sdp_streams - 1;
363 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
364 idx++;
365 }
366 break;
367 case DP_QUERY_PAYLOAD:
368 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
369 idx++;
370 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
371 idx++;
372 break;
373 case DP_REMOTE_DPCD_READ:
374 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
375 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
376 idx++;
377 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
378 idx++;
379 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
380 idx++;
381 buf[idx] = (req->u.dpcd_read.num_bytes);
382 idx++;
383 break;
384
385 case DP_REMOTE_DPCD_WRITE:
386 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
387 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
388 idx++;
389 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
390 idx++;
391 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
392 idx++;
393 buf[idx] = (req->u.dpcd_write.num_bytes);
394 idx++;
395 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
396 idx += req->u.dpcd_write.num_bytes;
397 break;
398 case DP_REMOTE_I2C_READ:
399 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
400 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
401 idx++;
402 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
403 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
404 idx++;
405 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
406 idx++;
407 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
408 idx += req->u.i2c_read.transactions[i].num_bytes;
409
410 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
411 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
412 idx++;
413 }
414 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
415 idx++;
416 buf[idx] = (req->u.i2c_read.num_bytes_read);
417 idx++;
418 break;
419
420 case DP_REMOTE_I2C_WRITE:
421 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
422 idx++;
423 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
424 idx++;
425 buf[idx] = (req->u.i2c_write.num_bytes);
426 idx++;
427 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
428 idx += req->u.i2c_write.num_bytes;
429 break;
430 }
431 raw->cur_len = idx;
432 }
433 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req);
434
435 /* Decode a sideband request we've encoded, mainly used for debugging */
436 static int
drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx * raw,struct drm_dp_sideband_msg_req_body * req)437 drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
438 struct drm_dp_sideband_msg_req_body *req)
439 {
440 const u8 *buf = raw->msg;
441 int i, idx = 0;
442
443 req->req_type = buf[idx++] & 0x7f;
444 switch (req->req_type) {
445 case DP_ENUM_PATH_RESOURCES:
446 case DP_POWER_DOWN_PHY:
447 case DP_POWER_UP_PHY:
448 req->u.port_num.port_number = (buf[idx] >> 4) & 0xf;
449 break;
450 case DP_ALLOCATE_PAYLOAD:
451 {
452 struct drm_dp_allocate_payload *a =
453 &req->u.allocate_payload;
454
455 a->number_sdp_streams = buf[idx] & 0xf;
456 a->port_number = (buf[idx] >> 4) & 0xf;
457
458 WARN_ON(buf[++idx] & 0x80);
459 a->vcpi = buf[idx] & 0x7f;
460
461 a->pbn = buf[++idx] << 8;
462 a->pbn |= buf[++idx];
463
464 idx++;
465 for (i = 0; i < a->number_sdp_streams; i++) {
466 a->sdp_stream_sink[i] =
467 (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf;
468 }
469 }
470 break;
471 case DP_QUERY_PAYLOAD:
472 req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf;
473 WARN_ON(buf[++idx] & 0x80);
474 req->u.query_payload.vcpi = buf[idx] & 0x7f;
475 break;
476 case DP_REMOTE_DPCD_READ:
477 {
478 struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read;
479
480 r->port_number = (buf[idx] >> 4) & 0xf;
481
482 r->dpcd_address = (buf[idx] << 16) & 0xf0000;
483 r->dpcd_address |= (buf[++idx] << 8) & 0xff00;
484 r->dpcd_address |= buf[++idx] & 0xff;
485
486 r->num_bytes = buf[++idx];
487 }
488 break;
489 case DP_REMOTE_DPCD_WRITE:
490 {
491 struct drm_dp_remote_dpcd_write *w =
492 &req->u.dpcd_write;
493
494 w->port_number = (buf[idx] >> 4) & 0xf;
495
496 w->dpcd_address = (buf[idx] << 16) & 0xf0000;
497 w->dpcd_address |= (buf[++idx] << 8) & 0xff00;
498 w->dpcd_address |= buf[++idx] & 0xff;
499
500 w->num_bytes = buf[++idx];
501
502 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
503 GFP_KERNEL);
504 if (!w->bytes)
505 return -ENOMEM;
506 }
507 break;
508 case DP_REMOTE_I2C_READ:
509 {
510 struct drm_dp_remote_i2c_read *r = &req->u.i2c_read;
511 struct drm_dp_remote_i2c_read_tx *tx;
512 bool failed = false;
513
514 r->num_transactions = buf[idx] & 0x3;
515 r->port_number = (buf[idx] >> 4) & 0xf;
516 for (i = 0; i < r->num_transactions; i++) {
517 tx = &r->transactions[i];
518
519 tx->i2c_dev_id = buf[++idx] & 0x7f;
520 tx->num_bytes = buf[++idx];
521 tx->bytes = kmemdup(&buf[++idx],
522 tx->num_bytes,
523 GFP_KERNEL);
524 if (!tx->bytes) {
525 failed = true;
526 break;
527 }
528 idx += tx->num_bytes;
529 tx->no_stop_bit = (buf[idx] >> 5) & 0x1;
530 tx->i2c_transaction_delay = buf[idx] & 0xf;
531 }
532
533 if (failed) {
534 for (i = 0; i < r->num_transactions; i++) {
535 tx = &r->transactions[i];
536 kfree(tx->bytes);
537 }
538 return -ENOMEM;
539 }
540
541 r->read_i2c_device_id = buf[++idx] & 0x7f;
542 r->num_bytes_read = buf[++idx];
543 }
544 break;
545 case DP_REMOTE_I2C_WRITE:
546 {
547 struct drm_dp_remote_i2c_write *w = &req->u.i2c_write;
548
549 w->port_number = (buf[idx] >> 4) & 0xf;
550 w->write_i2c_device_id = buf[++idx] & 0x7f;
551 w->num_bytes = buf[++idx];
552 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
553 GFP_KERNEL);
554 if (!w->bytes)
555 return -ENOMEM;
556 }
557 break;
558 }
559
560 return 0;
561 }
562 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req);
563
564 static void
drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body * req,int indent,struct drm_printer * printer)565 drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req,
566 int indent, struct drm_printer *printer)
567 {
568 int i;
569
570 #define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__)
571 if (req->req_type == DP_LINK_ADDRESS) {
572 /* No contents to print */
573 P("type=%s\n", drm_dp_mst_req_type_str(req->req_type));
574 return;
575 }
576
577 P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type));
578 indent++;
579
580 switch (req->req_type) {
581 case DP_ENUM_PATH_RESOURCES:
582 case DP_POWER_DOWN_PHY:
583 case DP_POWER_UP_PHY:
584 P("port=%d\n", req->u.port_num.port_number);
585 break;
586 case DP_ALLOCATE_PAYLOAD:
587 P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n",
588 req->u.allocate_payload.port_number,
589 req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn,
590 req->u.allocate_payload.number_sdp_streams,
591 req->u.allocate_payload.number_sdp_streams,
592 req->u.allocate_payload.sdp_stream_sink);
593 break;
594 case DP_QUERY_PAYLOAD:
595 P("port=%d vcpi=%d\n",
596 req->u.query_payload.port_number,
597 req->u.query_payload.vcpi);
598 break;
599 case DP_REMOTE_DPCD_READ:
600 P("port=%d dpcd_addr=%05x len=%d\n",
601 req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address,
602 req->u.dpcd_read.num_bytes);
603 break;
604 case DP_REMOTE_DPCD_WRITE:
605 P("port=%d addr=%05x len=%d: %*ph\n",
606 req->u.dpcd_write.port_number,
607 req->u.dpcd_write.dpcd_address,
608 req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes,
609 req->u.dpcd_write.bytes);
610 break;
611 case DP_REMOTE_I2C_READ:
612 P("port=%d num_tx=%d id=%d size=%d:\n",
613 req->u.i2c_read.port_number,
614 req->u.i2c_read.num_transactions,
615 req->u.i2c_read.read_i2c_device_id,
616 req->u.i2c_read.num_bytes_read);
617
618 indent++;
619 for (i = 0; i < req->u.i2c_read.num_transactions; i++) {
620 const struct drm_dp_remote_i2c_read_tx *rtx =
621 &req->u.i2c_read.transactions[i];
622
623 P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n",
624 i, rtx->i2c_dev_id, rtx->num_bytes,
625 rtx->no_stop_bit, rtx->i2c_transaction_delay,
626 rtx->num_bytes, rtx->bytes);
627 }
628 break;
629 case DP_REMOTE_I2C_WRITE:
630 P("port=%d id=%d size=%d: %*ph\n",
631 req->u.i2c_write.port_number,
632 req->u.i2c_write.write_i2c_device_id,
633 req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes,
634 req->u.i2c_write.bytes);
635 break;
636 default:
637 P("???\n");
638 break;
639 }
640 #undef P
641 }
642 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body);
643
644 static inline void
drm_dp_mst_dump_sideband_msg_tx(struct drm_printer * p,const struct drm_dp_sideband_msg_tx * txmsg)645 drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p,
646 const struct drm_dp_sideband_msg_tx *txmsg)
647 {
648 struct drm_dp_sideband_msg_req_body req;
649 char buf[64];
650 int ret;
651 int i;
652
653 drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf,
654 sizeof(buf));
655 drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n",
656 txmsg->cur_offset, txmsg->cur_len, txmsg->seqno,
657 drm_dp_mst_sideband_tx_state_str(txmsg->state),
658 txmsg->path_msg, buf);
659
660 ret = drm_dp_decode_sideband_req(txmsg, &req);
661 if (ret) {
662 drm_printf(p, "<failed to decode sideband req: %d>\n", ret);
663 return;
664 }
665 drm_dp_dump_sideband_msg_req_body(&req, 1, p);
666
667 switch (req.req_type) {
668 case DP_REMOTE_DPCD_WRITE:
669 kfree(req.u.dpcd_write.bytes);
670 break;
671 case DP_REMOTE_I2C_READ:
672 for (i = 0; i < req.u.i2c_read.num_transactions; i++)
673 kfree(req.u.i2c_read.transactions[i].bytes);
674 break;
675 case DP_REMOTE_I2C_WRITE:
676 kfree(req.u.i2c_write.bytes);
677 break;
678 }
679 }
680
drm_dp_crc_sideband_chunk_req(u8 * msg,u8 len)681 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
682 {
683 u8 crc4;
684 crc4 = drm_dp_msg_data_crc4(msg, len);
685 msg[len] = crc4;
686 }
687
drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body * rep,struct drm_dp_sideband_msg_tx * raw)688 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
689 struct drm_dp_sideband_msg_tx *raw)
690 {
691 int idx = 0;
692 u8 *buf = raw->msg;
693
694 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
695
696 raw->cur_len = idx;
697 }
698
699 /* this adds a chunk of msg to the builder to get the final msg */
drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx * msg,u8 * replybuf,u8 replybuflen,bool hdr)700 static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
701 u8 *replybuf, u8 replybuflen, bool hdr)
702 {
703 int ret;
704 u8 crc4 __unused; /* XXX Mistake? */
705
706 if (hdr) {
707 u8 hdrlen;
708 struct drm_dp_sideband_msg_hdr recv_hdr;
709 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
710 if (ret == false) {
711 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
712 return false;
713 }
714
715 /*
716 * ignore out-of-order messages or messages that are part of a
717 * failed transaction
718 */
719 if (!recv_hdr.somt && !msg->have_somt)
720 return false;
721
722 /* get length contained in this portion */
723 msg->curchunk_len = recv_hdr.msg_len;
724 msg->curchunk_hdrlen = hdrlen;
725
726 /* we have already gotten an somt - don't bother parsing */
727 if (recv_hdr.somt && msg->have_somt)
728 return false;
729
730 if (recv_hdr.somt) {
731 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
732 msg->have_somt = true;
733 }
734 if (recv_hdr.eomt)
735 msg->have_eomt = true;
736
737 /* copy the bytes for the remainder of this header chunk */
738 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
739 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
740 } else {
741 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
742 msg->curchunk_idx += replybuflen;
743 }
744
745 if (msg->curchunk_idx >= msg->curchunk_len) {
746 /* do CRC */
747 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
748 /* copy chunk into bigger msg */
749 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
750 msg->curlen += msg->curchunk_len - 1;
751 }
752 return true;
753 }
754
drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)755 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
756 struct drm_dp_sideband_msg_reply_body *repmsg)
757 {
758 int idx = 1;
759 int i;
760 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
761 idx += 16;
762 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
763 idx++;
764 if (idx > raw->curlen)
765 goto fail_len;
766 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
767 if (raw->msg[idx] & 0x80)
768 repmsg->u.link_addr.ports[i].input_port = 1;
769
770 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
771 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
772
773 idx++;
774 if (idx > raw->curlen)
775 goto fail_len;
776 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
777 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
778 if (repmsg->u.link_addr.ports[i].input_port == 0)
779 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
780 idx++;
781 if (idx > raw->curlen)
782 goto fail_len;
783 if (repmsg->u.link_addr.ports[i].input_port == 0) {
784 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
785 idx++;
786 if (idx > raw->curlen)
787 goto fail_len;
788 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
789 idx += 16;
790 if (idx > raw->curlen)
791 goto fail_len;
792 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
793 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
794 idx++;
795
796 }
797 if (idx > raw->curlen)
798 goto fail_len;
799 }
800
801 return true;
802 fail_len:
803 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
804 return false;
805 }
806
drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)807 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
808 struct drm_dp_sideband_msg_reply_body *repmsg)
809 {
810 int idx = 1;
811 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
812 idx++;
813 if (idx > raw->curlen)
814 goto fail_len;
815 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
816 idx++;
817 if (idx > raw->curlen)
818 goto fail_len;
819
820 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
821 return true;
822 fail_len:
823 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
824 return false;
825 }
826
drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)827 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
828 struct drm_dp_sideband_msg_reply_body *repmsg)
829 {
830 int idx = 1;
831 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
832 idx++;
833 if (idx > raw->curlen)
834 goto fail_len;
835 return true;
836 fail_len:
837 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
838 return false;
839 }
840
drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)841 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
842 struct drm_dp_sideband_msg_reply_body *repmsg)
843 {
844 int idx = 1;
845
846 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
847 idx++;
848 if (idx > raw->curlen)
849 goto fail_len;
850 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
851 idx++;
852 /* TODO check */
853 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
854 return true;
855 fail_len:
856 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
857 return false;
858 }
859
drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)860 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
861 struct drm_dp_sideband_msg_reply_body *repmsg)
862 {
863 int idx = 1;
864 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
865 repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1;
866 idx++;
867 if (idx > raw->curlen)
868 goto fail_len;
869 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
870 idx += 2;
871 if (idx > raw->curlen)
872 goto fail_len;
873 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
874 idx += 2;
875 if (idx > raw->curlen)
876 goto fail_len;
877 return true;
878 fail_len:
879 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
880 return false;
881 }
882
drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)883 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
884 struct drm_dp_sideband_msg_reply_body *repmsg)
885 {
886 int idx = 1;
887 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
888 idx++;
889 if (idx > raw->curlen)
890 goto fail_len;
891 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
892 idx++;
893 if (idx > raw->curlen)
894 goto fail_len;
895 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
896 idx += 2;
897 if (idx > raw->curlen)
898 goto fail_len;
899 return true;
900 fail_len:
901 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
902 return false;
903 }
904
drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)905 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
906 struct drm_dp_sideband_msg_reply_body *repmsg)
907 {
908 int idx = 1;
909 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
910 idx++;
911 if (idx > raw->curlen)
912 goto fail_len;
913 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
914 idx += 2;
915 if (idx > raw->curlen)
916 goto fail_len;
917 return true;
918 fail_len:
919 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
920 return false;
921 }
922
drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * repmsg)923 static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
924 struct drm_dp_sideband_msg_reply_body *repmsg)
925 {
926 int idx = 1;
927
928 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
929 idx++;
930 if (idx > raw->curlen) {
931 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
932 idx, raw->curlen);
933 return false;
934 }
935 return true;
936 }
937
drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_reply_body * msg)938 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
939 struct drm_dp_sideband_msg_reply_body *msg)
940 {
941 memset(msg, 0, sizeof(*msg));
942 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
943 msg->req_type = (raw->msg[0] & 0x7f);
944
945 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
946 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
947 msg->u.nak.reason = raw->msg[17];
948 msg->u.nak.nak_data = raw->msg[18];
949 return false;
950 }
951
952 switch (msg->req_type) {
953 case DP_LINK_ADDRESS:
954 return drm_dp_sideband_parse_link_address(raw, msg);
955 case DP_QUERY_PAYLOAD:
956 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
957 case DP_REMOTE_DPCD_READ:
958 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
959 case DP_REMOTE_DPCD_WRITE:
960 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
961 case DP_REMOTE_I2C_READ:
962 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
963 case DP_ENUM_PATH_RESOURCES:
964 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
965 case DP_ALLOCATE_PAYLOAD:
966 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
967 case DP_POWER_DOWN_PHY:
968 case DP_POWER_UP_PHY:
969 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
970 case DP_CLEAR_PAYLOAD_ID_TABLE:
971 return true; /* since there's nothing to parse */
972 default:
973 DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type,
974 drm_dp_mst_req_type_str(msg->req_type));
975 return false;
976 }
977 }
978
drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_req_body * msg)979 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
980 struct drm_dp_sideband_msg_req_body *msg)
981 {
982 int idx = 1;
983
984 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
985 idx++;
986 if (idx > raw->curlen)
987 goto fail_len;
988
989 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
990 idx += 16;
991 if (idx > raw->curlen)
992 goto fail_len;
993
994 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
995 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
996 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
997 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
998 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
999 idx++;
1000 return true;
1001 fail_len:
1002 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
1003 return false;
1004 }
1005
drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_req_body * msg)1006 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
1007 struct drm_dp_sideband_msg_req_body *msg)
1008 {
1009 int idx = 1;
1010
1011 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
1012 idx++;
1013 if (idx > raw->curlen)
1014 goto fail_len;
1015
1016 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
1017 idx += 16;
1018 if (idx > raw->curlen)
1019 goto fail_len;
1020
1021 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
1022 idx++;
1023 return true;
1024 fail_len:
1025 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
1026 return false;
1027 }
1028
drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx * raw,struct drm_dp_sideband_msg_req_body * msg)1029 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
1030 struct drm_dp_sideband_msg_req_body *msg)
1031 {
1032 memset(msg, 0, sizeof(*msg));
1033 msg->req_type = (raw->msg[0] & 0x7f);
1034
1035 switch (msg->req_type) {
1036 case DP_CONNECTION_STATUS_NOTIFY:
1037 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
1038 case DP_RESOURCE_STATUS_NOTIFY:
1039 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
1040 default:
1041 DRM_ERROR("Got unknown request 0x%02x (%s)\n", msg->req_type,
1042 drm_dp_mst_req_type_str(msg->req_type));
1043 return false;
1044 }
1045 }
1046
build_dpcd_write(struct drm_dp_sideband_msg_tx * msg,u8 port_num,u32 offset,u8 num_bytes,u8 * bytes)1047 static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
1048 {
1049 struct drm_dp_sideband_msg_req_body req;
1050
1051 req.req_type = DP_REMOTE_DPCD_WRITE;
1052 req.u.dpcd_write.port_number = port_num;
1053 req.u.dpcd_write.dpcd_address = offset;
1054 req.u.dpcd_write.num_bytes = num_bytes;
1055 req.u.dpcd_write.bytes = bytes;
1056 drm_dp_encode_sideband_req(&req, msg);
1057
1058 return 0;
1059 }
1060
build_link_address(struct drm_dp_sideband_msg_tx * msg)1061 static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
1062 {
1063 struct drm_dp_sideband_msg_req_body req;
1064
1065 req.req_type = DP_LINK_ADDRESS;
1066 drm_dp_encode_sideband_req(&req, msg);
1067 return 0;
1068 }
1069
build_clear_payload_id_table(struct drm_dp_sideband_msg_tx * msg)1070 static int build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
1071 {
1072 struct drm_dp_sideband_msg_req_body req;
1073
1074 req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE;
1075 drm_dp_encode_sideband_req(&req, msg);
1076 return 0;
1077 }
1078
build_enum_path_resources(struct drm_dp_sideband_msg_tx * msg,int port_num)1079 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
1080 {
1081 struct drm_dp_sideband_msg_req_body req;
1082
1083 req.req_type = DP_ENUM_PATH_RESOURCES;
1084 req.u.port_num.port_number = port_num;
1085 drm_dp_encode_sideband_req(&req, msg);
1086 msg->path_msg = true;
1087 return 0;
1088 }
1089
build_allocate_payload(struct drm_dp_sideband_msg_tx * msg,int port_num,u8 vcpi,uint16_t pbn,u8 number_sdp_streams,u8 * sdp_stream_sink)1090 static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
1091 u8 vcpi, uint16_t pbn,
1092 u8 number_sdp_streams,
1093 u8 *sdp_stream_sink)
1094 {
1095 struct drm_dp_sideband_msg_req_body req;
1096 memset(&req, 0, sizeof(req));
1097 req.req_type = DP_ALLOCATE_PAYLOAD;
1098 req.u.allocate_payload.port_number = port_num;
1099 req.u.allocate_payload.vcpi = vcpi;
1100 req.u.allocate_payload.pbn = pbn;
1101 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
1102 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
1103 number_sdp_streams);
1104 drm_dp_encode_sideband_req(&req, msg);
1105 msg->path_msg = true;
1106 return 0;
1107 }
1108
build_power_updown_phy(struct drm_dp_sideband_msg_tx * msg,int port_num,bool power_up)1109 static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
1110 int port_num, bool power_up)
1111 {
1112 struct drm_dp_sideband_msg_req_body req;
1113
1114 if (power_up)
1115 req.req_type = DP_POWER_UP_PHY;
1116 else
1117 req.req_type = DP_POWER_DOWN_PHY;
1118
1119 req.u.port_num.port_number = port_num;
1120 drm_dp_encode_sideband_req(&req, msg);
1121 msg->path_msg = true;
1122 return 0;
1123 }
1124
drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_vcpi * vcpi)1125 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1126 struct drm_dp_vcpi *vcpi)
1127 {
1128 int ret, vcpi_ret;
1129
1130 mutex_lock(&mgr->payload_lock);
1131 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
1132 if (ret > mgr->max_payloads) {
1133 ret = -EINVAL;
1134 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
1135 goto out_unlock;
1136 }
1137
1138 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
1139 if (vcpi_ret > mgr->max_payloads) {
1140 ret = -EINVAL;
1141 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
1142 goto out_unlock;
1143 }
1144
1145 set_bit(ret, &mgr->payload_mask);
1146 set_bit(vcpi_ret, &mgr->vcpi_mask);
1147 vcpi->vcpi = vcpi_ret + 1;
1148 mgr->proposed_vcpis[ret - 1] = vcpi;
1149 out_unlock:
1150 mutex_unlock(&mgr->payload_lock);
1151 return ret;
1152 }
1153
drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr * mgr,int vcpi)1154 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1155 int vcpi)
1156 {
1157 int i;
1158 if (vcpi == 0)
1159 return;
1160
1161 mutex_lock(&mgr->payload_lock);
1162 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
1163 clear_bit(vcpi - 1, &mgr->vcpi_mask);
1164
1165 for (i = 0; i < mgr->max_payloads; i++) {
1166 if (mgr->proposed_vcpis[i] &&
1167 mgr->proposed_vcpis[i]->vcpi == vcpi) {
1168 mgr->proposed_vcpis[i] = NULL;
1169 clear_bit(i + 1, &mgr->payload_mask);
1170 }
1171 }
1172 mutex_unlock(&mgr->payload_lock);
1173 }
1174
check_txmsg_state(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg)1175 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
1176 struct drm_dp_sideband_msg_tx *txmsg)
1177 {
1178 unsigned int state;
1179
1180 /*
1181 * All updates to txmsg->state are protected by mgr->qlock, and the two
1182 * cases we check here are terminal states. For those the barriers
1183 * provided by the wake_up/wait_event pair are enough.
1184 */
1185 state = READ_ONCE(txmsg->state);
1186 return (state == DRM_DP_SIDEBAND_TX_RX ||
1187 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
1188 }
1189
drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch * mstb,struct drm_dp_sideband_msg_tx * txmsg)1190 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
1191 struct drm_dp_sideband_msg_tx *txmsg)
1192 {
1193 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1194 int ret;
1195
1196 mutex_lock(&mstb->mgr->qlock);
1197 DRM_TIMED_WAIT_UNTIL(ret, &mgr->tx_waitq, &mstb->mgr->qlock, 4*HZ,
1198 check_txmsg_state(mgr, txmsg));
1199 if (ret > 0) {
1200 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
1201 ret = -EIO;
1202 goto out;
1203 }
1204 } else {
1205 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
1206
1207 /* dump some state */
1208 ret = -EIO;
1209
1210 /* remove from q */
1211 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
1212 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
1213 list_del(&txmsg->next);
1214 }
1215
1216 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
1217 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
1218 mstb->tx_slots[txmsg->seqno] = NULL;
1219 }
1220 mgr->is_waiting_for_dwn_reply = false;
1221
1222 }
1223 out:
1224 if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
1225 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1226
1227 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
1228 }
1229 mutex_unlock(&mgr->qlock);
1230
1231 drm_dp_mst_kick_tx(mgr);
1232 return ret;
1233 }
1234
drm_dp_add_mst_branch_device(u8 lct,u8 * rad)1235 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
1236 {
1237 struct drm_dp_mst_branch *mstb;
1238
1239 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
1240 if (!mstb)
1241 return NULL;
1242
1243 mstb->lct = lct;
1244 if (lct > 1)
1245 memcpy(mstb->rad, rad, lct / 2);
1246 INIT_LIST_HEAD(&mstb->ports);
1247 kref_init(&mstb->topology_kref);
1248 kref_init(&mstb->malloc_kref);
1249 return mstb;
1250 }
1251
drm_dp_free_mst_branch_device(struct kref * kref)1252 static void drm_dp_free_mst_branch_device(struct kref *kref)
1253 {
1254 struct drm_dp_mst_branch *mstb =
1255 container_of(kref, struct drm_dp_mst_branch, malloc_kref);
1256
1257 if (mstb->port_parent)
1258 drm_dp_mst_put_port_malloc(mstb->port_parent);
1259
1260 kfree(mstb);
1261 }
1262
1263 /**
1264 * DOC: Branch device and port refcounting
1265 *
1266 * Topology refcount overview
1267 * ~~~~~~~~~~~~~~~~~~~~~~~~~~
1268 *
1269 * The refcounting schemes for &struct drm_dp_mst_branch and &struct
1270 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
1271 * two different kinds of refcounts: topology refcounts, and malloc refcounts.
1272 *
1273 * Topology refcounts are not exposed to drivers, and are handled internally
1274 * by the DP MST helpers. The helpers use them in order to prevent the
1275 * in-memory topology state from being changed in the middle of critical
1276 * operations like changing the internal state of payload allocations. This
1277 * means each branch and port will be considered to be connected to the rest
1278 * of the topology until its topology refcount reaches zero. Additionally,
1279 * for ports this means that their associated &struct drm_connector will stay
1280 * registered with userspace until the port's refcount reaches 0.
1281 *
1282 * Malloc refcount overview
1283 * ~~~~~~~~~~~~~~~~~~~~~~~~
1284 *
1285 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct
1286 * drm_dp_mst_branch allocated even after all of its topology references have
1287 * been dropped, so that the driver or MST helpers can safely access each
1288 * branch's last known state before it was disconnected from the topology.
1289 * When the malloc refcount of a port or branch reaches 0, the memory
1290 * allocation containing the &struct drm_dp_mst_branch or &struct
1291 * drm_dp_mst_port respectively will be freed.
1292 *
1293 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
1294 * to drivers. As of writing this documentation, there are no drivers that
1295 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
1296 * helpers. Exposing this API to drivers in a race-free manner would take more
1297 * tweaking of the refcounting scheme, however patches are welcome provided
1298 * there is a legitimate driver usecase for this.
1299 *
1300 * Refcount relationships in a topology
1301 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1302 *
1303 * Let's take a look at why the relationship between topology and malloc
1304 * refcounts is designed the way it is.
1305 *
1306 * .. kernel-figure:: dp-mst/topology-figure-1.dot
1307 *
1308 * An example of topology and malloc refs in a DP MST topology with two
1309 * active payloads. Topology refcount increments are indicated by solid
1310 * lines, and malloc refcount increments are indicated by dashed lines.
1311 * Each starts from the branch which incremented the refcount, and ends at
1312 * the branch to which the refcount belongs to, i.e. the arrow points the
1313 * same way as the C pointers used to reference a structure.
1314 *
1315 * As you can see in the above figure, every branch increments the topology
1316 * refcount of its children, and increments the malloc refcount of its
1317 * parent. Additionally, every payload increments the malloc refcount of its
1318 * assigned port by 1.
1319 *
1320 * So, what would happen if MSTB #3 from the above figure was unplugged from
1321 * the system, but the driver hadn't yet removed payload #2 from port #3? The
1322 * topology would start to look like the figure below.
1323 *
1324 * .. kernel-figure:: dp-mst/topology-figure-2.dot
1325 *
1326 * Ports and branch devices which have been released from memory are
1327 * colored grey, and references which have been removed are colored red.
1328 *
1329 * Whenever a port or branch device's topology refcount reaches zero, it will
1330 * decrement the topology refcounts of all its children, the malloc refcount
1331 * of its parent, and finally its own malloc refcount. For MSTB #4 and port
1332 * #4, this means they both have been disconnected from the topology and freed
1333 * from memory. But, because payload #2 is still holding a reference to port
1334 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
1335 * is still accessible from memory. This also means port #3 has not yet
1336 * decremented the malloc refcount of MSTB #3, so its &struct
1337 * drm_dp_mst_branch will also stay allocated in memory until port #3's
1338 * malloc refcount reaches 0.
1339 *
1340 * This relationship is necessary because in order to release payload #2, we
1341 * need to be able to figure out the last relative of port #3 that's still
1342 * connected to the topology. In this case, we would travel up the topology as
1343 * shown below.
1344 *
1345 * .. kernel-figure:: dp-mst/topology-figure-3.dot
1346 *
1347 * And finally, remove payload #2 by communicating with port #2 through
1348 * sideband transactions.
1349 */
1350
1351 /**
1352 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
1353 * device
1354 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
1355 *
1356 * Increments &drm_dp_mst_branch.malloc_kref. When
1357 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1358 * will be released and @mstb may no longer be used.
1359 *
1360 * See also: drm_dp_mst_put_mstb_malloc()
1361 */
1362 static void
drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch * mstb)1363 drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
1364 {
1365 kref_get(&mstb->malloc_kref);
1366 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
1367 }
1368
1369 /**
1370 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
1371 * device
1372 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
1373 *
1374 * Decrements &drm_dp_mst_branch.malloc_kref. When
1375 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1376 * will be released and @mstb may no longer be used.
1377 *
1378 * See also: drm_dp_mst_get_mstb_malloc()
1379 */
1380 static void
drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch * mstb)1381 drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
1382 {
1383 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
1384 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
1385 }
1386
drm_dp_free_mst_port(struct kref * kref)1387 static void drm_dp_free_mst_port(struct kref *kref)
1388 {
1389 struct drm_dp_mst_port *port =
1390 container_of(kref, struct drm_dp_mst_port, malloc_kref);
1391
1392 drm_dp_mst_put_mstb_malloc(port->parent);
1393 kfree(port);
1394 }
1395
1396 /**
1397 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
1398 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of
1399 *
1400 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1401 * reaches 0, the memory allocation for @port will be released and @port may
1402 * no longer be used.
1403 *
1404 * Because @port could potentially be freed at any time by the DP MST helpers
1405 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
1406 * function, drivers that which to make use of &struct drm_dp_mst_port should
1407 * ensure that they grab at least one main malloc reference to their MST ports
1408 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
1409 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
1410 *
1411 * See also: drm_dp_mst_put_port_malloc()
1412 */
1413 void
drm_dp_mst_get_port_malloc(struct drm_dp_mst_port * port)1414 drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
1415 {
1416 kref_get(&port->malloc_kref);
1417 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref));
1418 }
1419 EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
1420
1421 /**
1422 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
1423 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
1424 *
1425 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1426 * reaches 0, the memory allocation for @port will be released and @port may
1427 * no longer be used.
1428 *
1429 * See also: drm_dp_mst_get_port_malloc()
1430 */
1431 void
drm_dp_mst_put_port_malloc(struct drm_dp_mst_port * port)1432 drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
1433 {
1434 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
1435 kref_put(&port->malloc_kref, drm_dp_free_mst_port);
1436 }
1437 EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
1438
1439 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
1440
1441 #define STACK_DEPTH 8
1442
1443 static noinline void
__topology_ref_save(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_topology_ref_history * history,enum drm_dp_mst_topology_ref_type type)1444 __topology_ref_save(struct drm_dp_mst_topology_mgr *mgr,
1445 struct drm_dp_mst_topology_ref_history *history,
1446 enum drm_dp_mst_topology_ref_type type)
1447 {
1448 struct drm_dp_mst_topology_ref_entry *entry = NULL;
1449 depot_stack_handle_t backtrace;
1450 ulong stack_entries[STACK_DEPTH];
1451 uint n;
1452 int i;
1453
1454 n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1);
1455 backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL);
1456 if (!backtrace)
1457 return;
1458
1459 /* Try to find an existing entry for this backtrace */
1460 for (i = 0; i < history->len; i++) {
1461 if (history->entries[i].backtrace == backtrace) {
1462 entry = &history->entries[i];
1463 break;
1464 }
1465 }
1466
1467 /* Otherwise add one */
1468 if (!entry) {
1469 struct drm_dp_mst_topology_ref_entry *new;
1470 int new_len = history->len + 1;
1471
1472 new = krealloc(history->entries, sizeof(*new) * new_len,
1473 GFP_KERNEL);
1474 if (!new)
1475 return;
1476
1477 entry = &new[history->len];
1478 history->len = new_len;
1479 history->entries = new;
1480
1481 entry->backtrace = backtrace;
1482 entry->type = type;
1483 entry->count = 0;
1484 }
1485 entry->count++;
1486 entry->ts_nsec = ktime_get_ns();
1487 }
1488
1489 static int
topology_ref_history_cmp(const void * a,const void * b)1490 topology_ref_history_cmp(const void *a, const void *b)
1491 {
1492 const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b;
1493
1494 if (entry_a->ts_nsec > entry_b->ts_nsec)
1495 return 1;
1496 else if (entry_a->ts_nsec < entry_b->ts_nsec)
1497 return -1;
1498 else
1499 return 0;
1500 }
1501
1502 static inline const char *
topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type)1503 topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type)
1504 {
1505 if (type == DRM_DP_MST_TOPOLOGY_REF_GET)
1506 return "get";
1507 else
1508 return "put";
1509 }
1510
1511 static void
__dump_topology_ref_history(struct drm_dp_mst_topology_ref_history * history,void * ptr,const char * type_str)1512 __dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history,
1513 void *ptr, const char *type_str)
1514 {
1515 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1516 char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1517 int i;
1518
1519 if (!buf)
1520 return;
1521
1522 if (!history->len)
1523 goto out;
1524
1525 /* First, sort the list so that it goes from oldest to newest
1526 * reference entry
1527 */
1528 sort(history->entries, history->len, sizeof(*history->entries),
1529 topology_ref_history_cmp, NULL);
1530
1531 drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n",
1532 type_str, ptr);
1533
1534 for (i = 0; i < history->len; i++) {
1535 const struct drm_dp_mst_topology_ref_entry *entry =
1536 &history->entries[i];
1537 ulong *entries;
1538 uint nr_entries;
1539 u64 ts_nsec = entry->ts_nsec;
1540 u32 rem_nsec = do_div(ts_nsec, 1000000000);
1541
1542 nr_entries = stack_depot_fetch(entry->backtrace, &entries);
1543 stack_trace_snprint(buf, PAGE_SIZE, entries, nr_entries, 4);
1544
1545 drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s",
1546 entry->count,
1547 topology_ref_type_to_str(entry->type),
1548 ts_nsec, rem_nsec / 1000, buf);
1549 }
1550
1551 /* Now free the history, since this is the only time we expose it */
1552 kfree(history->entries);
1553 out:
1554 kfree(buf);
1555 }
1556
1557 static __always_inline void
drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch * mstb)1558 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb)
1559 {
1560 __dump_topology_ref_history(&mstb->topology_ref_history, mstb,
1561 "MSTB");
1562 }
1563
1564 static __always_inline void
drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port * port)1565 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port)
1566 {
1567 __dump_topology_ref_history(&port->topology_ref_history, port,
1568 "Port");
1569 }
1570
1571 static __always_inline void
save_mstb_topology_ref(struct drm_dp_mst_branch * mstb,enum drm_dp_mst_topology_ref_type type)1572 save_mstb_topology_ref(struct drm_dp_mst_branch *mstb,
1573 enum drm_dp_mst_topology_ref_type type)
1574 {
1575 __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type);
1576 }
1577
1578 static __always_inline void
save_port_topology_ref(struct drm_dp_mst_port * port,enum drm_dp_mst_topology_ref_type type)1579 save_port_topology_ref(struct drm_dp_mst_port *port,
1580 enum drm_dp_mst_topology_ref_type type)
1581 {
1582 __topology_ref_save(port->mgr, &port->topology_ref_history, type);
1583 }
1584
1585 static inline void
topology_ref_history_lock(struct drm_dp_mst_topology_mgr * mgr)1586 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr)
1587 {
1588 mutex_lock(&mgr->topology_ref_history_lock);
1589 }
1590
1591 static inline void
topology_ref_history_unlock(struct drm_dp_mst_topology_mgr * mgr)1592 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr)
1593 {
1594 mutex_unlock(&mgr->topology_ref_history_lock);
1595 }
1596 #else
1597 static inline void
topology_ref_history_lock(struct drm_dp_mst_topology_mgr * mgr)1598 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {}
1599 static inline void
topology_ref_history_unlock(struct drm_dp_mst_topology_mgr * mgr)1600 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {}
1601 static inline void
drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch * mstb)1602 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {}
1603 static inline void
drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port * port)1604 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {}
1605 #define save_mstb_topology_ref(mstb, type)
1606 #define save_port_topology_ref(port, type)
1607 #endif
1608
drm_dp_destroy_mst_branch_device(struct kref * kref)1609 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
1610 {
1611 struct drm_dp_mst_branch *mstb =
1612 container_of(kref, struct drm_dp_mst_branch, topology_kref);
1613 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1614
1615 drm_dp_mst_dump_mstb_topology_history(mstb);
1616
1617 INIT_LIST_HEAD(&mstb->destroy_next);
1618
1619 /*
1620 * This can get called under mgr->mutex, so we need to perform the
1621 * actual destruction of the mstb in another worker
1622 */
1623 mutex_lock(&mgr->delayed_destroy_lock);
1624 list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list);
1625 mutex_unlock(&mgr->delayed_destroy_lock);
1626 schedule_work(&mgr->delayed_destroy_work);
1627 }
1628
1629 /**
1630 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1631 * branch device unless it's zero
1632 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
1633 *
1634 * Attempts to grab a topology reference to @mstb, if it hasn't yet been
1635 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
1636 * reached 0). Holding a topology reference implies that a malloc reference
1637 * will be held to @mstb as long as the user holds the topology reference.
1638 *
1639 * Care should be taken to ensure that the user has at least one malloc
1640 * reference to @mstb. If you already have a topology reference to @mstb, you
1641 * should use drm_dp_mst_topology_get_mstb() instead.
1642 *
1643 * See also:
1644 * drm_dp_mst_topology_get_mstb()
1645 * drm_dp_mst_topology_put_mstb()
1646 *
1647 * Returns:
1648 * * 1: A topology reference was grabbed successfully
1649 * * 0: @port is no longer in the topology, no reference was grabbed
1650 */
1651 static int __must_check
drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch * mstb)1652 drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
1653 {
1654 int ret;
1655
1656 topology_ref_history_lock(mstb->mgr);
1657 ret = kref_get_unless_zero(&mstb->topology_kref);
1658 if (ret) {
1659 DRM_DEBUG("mstb %p (%d)\n",
1660 mstb, kref_read(&mstb->topology_kref));
1661 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1662 }
1663
1664 topology_ref_history_unlock(mstb->mgr);
1665
1666 return ret;
1667 }
1668
1669 /**
1670 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
1671 * branch device
1672 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
1673 *
1674 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or
1675 * not it's already reached 0. This is only valid to use in scenarios where
1676 * you are already guaranteed to have at least one active topology reference
1677 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
1678 *
1679 * See also:
1680 * drm_dp_mst_topology_try_get_mstb()
1681 * drm_dp_mst_topology_put_mstb()
1682 */
drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch * mstb)1683 static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
1684 {
1685 topology_ref_history_lock(mstb->mgr);
1686
1687 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1688 WARN_ON(kref_read(&mstb->topology_kref) == 0);
1689 kref_get(&mstb->topology_kref);
1690 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1691
1692 topology_ref_history_unlock(mstb->mgr);
1693 }
1694
1695 /**
1696 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
1697 * device
1698 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from
1699 *
1700 * Releases a topology reference from @mstb by decrementing
1701 * &drm_dp_mst_branch.topology_kref.
1702 *
1703 * See also:
1704 * drm_dp_mst_topology_try_get_mstb()
1705 * drm_dp_mst_topology_get_mstb()
1706 */
1707 static void
drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch * mstb)1708 drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
1709 {
1710 topology_ref_history_lock(mstb->mgr);
1711
1712 DRM_DEBUG("mstb %p (%d)\n",
1713 mstb, kref_read(&mstb->topology_kref) - 1);
1714 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT);
1715
1716 topology_ref_history_unlock(mstb->mgr);
1717 kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
1718 }
1719
drm_dp_destroy_port(struct kref * kref)1720 static void drm_dp_destroy_port(struct kref *kref)
1721 {
1722 struct drm_dp_mst_port *port =
1723 container_of(kref, struct drm_dp_mst_port, topology_kref);
1724 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1725
1726 drm_dp_mst_dump_port_topology_history(port);
1727
1728 /* There's nothing that needs locking to destroy an input port yet */
1729 if (port->input) {
1730 drm_dp_mst_put_port_malloc(port);
1731 return;
1732 }
1733
1734 kfree(port->cached_edid);
1735
1736 /*
1737 * we can't destroy the connector here, as we might be holding the
1738 * mode_config.mutex from an EDID retrieval
1739 */
1740 mutex_lock(&mgr->delayed_destroy_lock);
1741 list_add(&port->next, &mgr->destroy_port_list);
1742 mutex_unlock(&mgr->delayed_destroy_lock);
1743 schedule_work(&mgr->delayed_destroy_work);
1744 }
1745
1746 /**
1747 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
1748 * port unless it's zero
1749 * @port: &struct drm_dp_mst_port to increment the topology refcount of
1750 *
1751 * Attempts to grab a topology reference to @port, if it hasn't yet been
1752 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
1753 * 0). Holding a topology reference implies that a malloc reference will be
1754 * held to @port as long as the user holds the topology reference.
1755 *
1756 * Care should be taken to ensure that the user has at least one malloc
1757 * reference to @port. If you already have a topology reference to @port, you
1758 * should use drm_dp_mst_topology_get_port() instead.
1759 *
1760 * See also:
1761 * drm_dp_mst_topology_get_port()
1762 * drm_dp_mst_topology_put_port()
1763 *
1764 * Returns:
1765 * * 1: A topology reference was grabbed successfully
1766 * * 0: @port is no longer in the topology, no reference was grabbed
1767 */
1768 static int __must_check
drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port * port)1769 drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
1770 {
1771 int ret;
1772
1773 topology_ref_history_lock(port->mgr);
1774 ret = kref_get_unless_zero(&port->topology_kref);
1775 if (ret) {
1776 DRM_DEBUG("port %p (%d)\n",
1777 port, kref_read(&port->topology_kref));
1778 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1779 }
1780
1781 topology_ref_history_unlock(port->mgr);
1782 return ret;
1783 }
1784
1785 /**
1786 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
1787 * @port: The &struct drm_dp_mst_port to increment the topology refcount of
1788 *
1789 * Increments &drm_dp_mst_port.topology_refcount without checking whether or
1790 * not it's already reached 0. This is only valid to use in scenarios where
1791 * you are already guaranteed to have at least one active topology reference
1792 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
1793 *
1794 * See also:
1795 * drm_dp_mst_topology_try_get_port()
1796 * drm_dp_mst_topology_put_port()
1797 */
drm_dp_mst_topology_get_port(struct drm_dp_mst_port * port)1798 static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
1799 {
1800 topology_ref_history_lock(port->mgr);
1801
1802 WARN_ON(kref_read(&port->topology_kref) == 0);
1803 kref_get(&port->topology_kref);
1804 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref));
1805 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1806
1807 topology_ref_history_unlock(port->mgr);
1808 }
1809
1810 /**
1811 * drm_dp_mst_topology_put_port() - release a topology reference to a port
1812 * @port: The &struct drm_dp_mst_port to release the topology reference from
1813 *
1814 * Releases a topology reference from @port by decrementing
1815 * &drm_dp_mst_port.topology_kref.
1816 *
1817 * See also:
1818 * drm_dp_mst_topology_try_get_port()
1819 * drm_dp_mst_topology_get_port()
1820 */
drm_dp_mst_topology_put_port(struct drm_dp_mst_port * port)1821 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
1822 {
1823 topology_ref_history_lock(port->mgr);
1824
1825 DRM_DEBUG("port %p (%d)\n",
1826 port, kref_read(&port->topology_kref) - 1);
1827 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT);
1828
1829 topology_ref_history_unlock(port->mgr);
1830 kref_put(&port->topology_kref, drm_dp_destroy_port);
1831 }
1832
1833 static struct drm_dp_mst_branch *
drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch * mstb,struct drm_dp_mst_branch * to_find)1834 drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
1835 struct drm_dp_mst_branch *to_find)
1836 {
1837 struct drm_dp_mst_port *port;
1838 struct drm_dp_mst_branch *rmstb;
1839
1840 if (to_find == mstb)
1841 return mstb;
1842
1843 list_for_each_entry(port, &mstb->ports, next) {
1844 if (port->mstb) {
1845 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1846 port->mstb, to_find);
1847 if (rmstb)
1848 return rmstb;
1849 }
1850 }
1851 return NULL;
1852 }
1853
1854 static struct drm_dp_mst_branch *
drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb)1855 drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
1856 struct drm_dp_mst_branch *mstb)
1857 {
1858 struct drm_dp_mst_branch *rmstb = NULL;
1859
1860 mutex_lock(&mgr->lock);
1861 if (mgr->mst_primary) {
1862 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1863 mgr->mst_primary, mstb);
1864
1865 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
1866 rmstb = NULL;
1867 }
1868 mutex_unlock(&mgr->lock);
1869 return rmstb;
1870 }
1871
1872 static struct drm_dp_mst_port *
drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch * mstb,struct drm_dp_mst_port * to_find)1873 drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
1874 struct drm_dp_mst_port *to_find)
1875 {
1876 struct drm_dp_mst_port *port, *mport;
1877
1878 list_for_each_entry(port, &mstb->ports, next) {
1879 if (port == to_find)
1880 return port;
1881
1882 if (port->mstb) {
1883 mport = drm_dp_mst_topology_get_port_validated_locked(
1884 port->mstb, to_find);
1885 if (mport)
1886 return mport;
1887 }
1888 }
1889 return NULL;
1890 }
1891
1892 static struct drm_dp_mst_port *
drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)1893 drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
1894 struct drm_dp_mst_port *port)
1895 {
1896 struct drm_dp_mst_port *rport = NULL;
1897
1898 mutex_lock(&mgr->lock);
1899 if (mgr->mst_primary) {
1900 rport = drm_dp_mst_topology_get_port_validated_locked(
1901 mgr->mst_primary, port);
1902
1903 if (rport && !drm_dp_mst_topology_try_get_port(rport))
1904 rport = NULL;
1905 }
1906 mutex_unlock(&mgr->lock);
1907 return rport;
1908 }
1909
drm_dp_get_port(struct drm_dp_mst_branch * mstb,u8 port_num)1910 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
1911 {
1912 struct drm_dp_mst_port *port;
1913 int ret;
1914
1915 list_for_each_entry(port, &mstb->ports, next) {
1916 if (port->port_num == port_num) {
1917 ret = drm_dp_mst_topology_try_get_port(port);
1918 return ret ? port : NULL;
1919 }
1920 }
1921
1922 return NULL;
1923 }
1924
1925 /*
1926 * calculate a new RAD for this MST branch device
1927 * if parent has an LCT of 2 then it has 1 nibble of RAD,
1928 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1929 */
drm_dp_calculate_rad(struct drm_dp_mst_port * port,u8 * rad)1930 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1931 u8 *rad)
1932 {
1933 int parent_lct = port->parent->lct;
1934 int shift = 4;
1935 int idx = (parent_lct - 1) / 2;
1936 if (parent_lct > 1) {
1937 memcpy(rad, port->parent->rad, idx + 1);
1938 shift = (parent_lct % 2) ? 4 : 0;
1939 } else
1940 rad[0] = 0;
1941
1942 rad[idx] |= port->port_num << shift;
1943 return parent_lct + 1;
1944 }
1945
drm_dp_mst_is_dp_mst_end_device(u8 pdt,bool mcs)1946 static bool drm_dp_mst_is_dp_mst_end_device(u8 pdt, bool mcs)
1947 {
1948 switch (pdt) {
1949 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1950 case DP_PEER_DEVICE_SST_SINK:
1951 return true;
1952 case DP_PEER_DEVICE_MST_BRANCHING:
1953 /* For sst branch device */
1954 if (!mcs)
1955 return true;
1956
1957 return false;
1958 }
1959 return true;
1960 }
1961
1962 static int
drm_dp_port_set_pdt(struct drm_dp_mst_port * port,u8 new_pdt,bool new_mcs)1963 drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
1964 bool new_mcs)
1965 {
1966 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1967 struct drm_dp_mst_branch *mstb;
1968 u8 rad[8], lct;
1969 int ret = 0;
1970
1971 if (port->pdt == new_pdt && port->mcs == new_mcs)
1972 return 0;
1973
1974 /* Teardown the old pdt, if there is one */
1975 if (port->pdt != DP_PEER_DEVICE_NONE) {
1976 if (drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
1977 /*
1978 * If the new PDT would also have an i2c bus,
1979 * don't bother with reregistering it
1980 */
1981 if (new_pdt != DP_PEER_DEVICE_NONE &&
1982 drm_dp_mst_is_dp_mst_end_device(new_pdt, new_mcs)) {
1983 port->pdt = new_pdt;
1984 port->mcs = new_mcs;
1985 return 0;
1986 }
1987
1988 /* remove i2c over sideband */
1989 drm_dp_mst_unregister_i2c_bus(&port->aux);
1990 } else {
1991 mutex_lock(&mgr->lock);
1992 drm_dp_mst_topology_put_mstb(port->mstb);
1993 port->mstb = NULL;
1994 mutex_unlock(&mgr->lock);
1995 }
1996 }
1997
1998 port->pdt = new_pdt;
1999 port->mcs = new_mcs;
2000
2001 if (port->pdt != DP_PEER_DEVICE_NONE) {
2002 if (drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
2003 /* add i2c over sideband */
2004 ret = drm_dp_mst_register_i2c_bus(&port->aux);
2005 } else {
2006 lct = drm_dp_calculate_rad(port, rad);
2007 mstb = drm_dp_add_mst_branch_device(lct, rad);
2008 if (!mstb) {
2009 ret = -ENOMEM;
2010 DRM_ERROR("Failed to create MSTB for port %p",
2011 port);
2012 goto out;
2013 }
2014
2015 mutex_lock(&mgr->lock);
2016 port->mstb = mstb;
2017 mstb->mgr = port->mgr;
2018 mstb->port_parent = port;
2019
2020 /*
2021 * Make sure this port's memory allocation stays
2022 * around until its child MSTB releases it
2023 */
2024 drm_dp_mst_get_port_malloc(port);
2025 mutex_unlock(&mgr->lock);
2026
2027 /* And make sure we send a link address for this */
2028 ret = 1;
2029 }
2030 }
2031
2032 out:
2033 if (ret < 0)
2034 port->pdt = DP_PEER_DEVICE_NONE;
2035 return ret;
2036 }
2037
2038 /**
2039 * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
2040 * @aux: Fake sideband AUX CH
2041 * @offset: address of the (first) register to read
2042 * @buffer: buffer to store the register values
2043 * @size: number of bytes in @buffer
2044 *
2045 * Performs the same functionality for remote devices via
2046 * sideband messaging as drm_dp_dpcd_read() does for local
2047 * devices via actual AUX CH.
2048 *
2049 * Return: Number of bytes read, or negative error code on failure.
2050 */
drm_dp_mst_dpcd_read(struct drm_dp_aux * aux,unsigned int offset,void * buffer,size_t size)2051 ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
2052 unsigned int offset, void *buffer, size_t size)
2053 {
2054 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2055 aux);
2056
2057 return drm_dp_send_dpcd_read(port->mgr, port,
2058 offset, size, buffer);
2059 }
2060
2061 /**
2062 * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
2063 * @aux: Fake sideband AUX CH
2064 * @offset: address of the (first) register to write
2065 * @buffer: buffer containing the values to write
2066 * @size: number of bytes in @buffer
2067 *
2068 * Performs the same functionality for remote devices via
2069 * sideband messaging as drm_dp_dpcd_write() does for local
2070 * devices via actual AUX CH.
2071 *
2072 * Return: 0 on success, negative error code on failure.
2073 */
drm_dp_mst_dpcd_write(struct drm_dp_aux * aux,unsigned int offset,void * buffer,size_t size)2074 ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
2075 unsigned int offset, void *buffer, size_t size)
2076 {
2077 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2078 aux);
2079
2080 return drm_dp_send_dpcd_write(port->mgr, port,
2081 offset, size, buffer);
2082 }
2083
drm_dp_check_mstb_guid(struct drm_dp_mst_branch * mstb,u8 * guid)2084 static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
2085 {
2086 int ret __unused;
2087
2088 memcpy(mstb->guid, guid, 16);
2089
2090 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
2091 if (mstb->port_parent) {
2092 ret = drm_dp_send_dpcd_write(
2093 mstb->mgr,
2094 mstb->port_parent,
2095 DP_GUID,
2096 16,
2097 mstb->guid);
2098 } else {
2099
2100 ret = drm_dp_dpcd_write(
2101 mstb->mgr->aux,
2102 DP_GUID,
2103 mstb->guid,
2104 16);
2105 }
2106 }
2107 }
2108
build_mst_prop_path(const struct drm_dp_mst_branch * mstb,int pnum,char * proppath,size_t proppath_size)2109 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
2110 int pnum,
2111 char *proppath,
2112 size_t proppath_size)
2113 {
2114 int i;
2115 char temp[8];
2116 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
2117 for (i = 0; i < (mstb->lct - 1); i++) {
2118 int shift = (i % 2) ? 0 : 4;
2119 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
2120 snprintf(temp, sizeof(temp), "-%d", port_num);
2121 strlcat(proppath, temp, proppath_size);
2122 }
2123 snprintf(temp, sizeof(temp), "-%d", pnum);
2124 strlcat(proppath, temp, proppath_size);
2125 }
2126
2127 /**
2128 * drm_dp_mst_connector_late_register() - Late MST connector registration
2129 * @connector: The MST connector
2130 * @port: The MST port for this connector
2131 *
2132 * Helper to register the remote aux device for this MST port. Drivers should
2133 * call this from their mst connector's late_register hook to enable MST aux
2134 * devices.
2135 *
2136 * Return: 0 on success, negative error code on failure.
2137 */
drm_dp_mst_connector_late_register(struct drm_connector * connector,struct drm_dp_mst_port * port)2138 int drm_dp_mst_connector_late_register(struct drm_connector *connector,
2139 struct drm_dp_mst_port *port)
2140 {
2141 DRM_DEBUG_KMS("registering %s remote bus for %s\n",
2142 port->aux.name, device_xname(connector->dev->dev));
2143
2144 port->aux.dev = connector->kdev;
2145 return drm_dp_aux_register_devnode(&port->aux);
2146 }
2147 EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
2148
2149 /**
2150 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
2151 * @connector: The MST connector
2152 * @port: The MST port for this connector
2153 *
2154 * Helper to unregister the remote aux device for this MST port, registered by
2155 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst
2156 * connector's early_unregister hook.
2157 */
drm_dp_mst_connector_early_unregister(struct drm_connector * connector,struct drm_dp_mst_port * port)2158 void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
2159 struct drm_dp_mst_port *port)
2160 {
2161 DRM_DEBUG_KMS("unregistering %s remote bus for %s\n",
2162 port->aux.name, device_xname(connector->dev->dev));
2163 drm_dp_aux_unregister_devnode(&port->aux);
2164 }
2165 EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
2166
2167 static void
drm_dp_mst_port_add_connector(struct drm_dp_mst_branch * mstb,struct drm_dp_mst_port * port)2168 drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
2169 struct drm_dp_mst_port *port)
2170 {
2171 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2172 char proppath[255];
2173 int ret;
2174
2175 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
2176 port->connector = mgr->cbs->add_connector(mgr, port, proppath);
2177 if (!port->connector) {
2178 ret = -ENOMEM;
2179 goto error;
2180 }
2181
2182 if (port->pdt != DP_PEER_DEVICE_NONE &&
2183 drm_dp_mst_is_dp_mst_end_device(port->pdt, port->mcs)) {
2184 port->cached_edid = drm_get_edid(port->connector,
2185 &port->aux.ddc);
2186 drm_connector_set_tile_property(port->connector);
2187 }
2188
2189 mgr->cbs->register_connector(port->connector);
2190 return;
2191
2192 error:
2193 DRM_ERROR("Failed to create connector for port %p: %d\n", port, ret);
2194 }
2195
2196 /*
2197 * Drop a topology reference, and unlink the port from the in-memory topology
2198 * layout
2199 */
2200 static void
drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)2201 drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr,
2202 struct drm_dp_mst_port *port)
2203 {
2204 mutex_lock(&mgr->lock);
2205 port->parent->num_ports--;
2206 list_del(&port->next);
2207 mutex_unlock(&mgr->lock);
2208 drm_dp_mst_topology_put_port(port);
2209 }
2210
2211 static struct drm_dp_mst_port *
drm_dp_mst_add_port(struct drm_device * dev,struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb,u8 port_number)2212 drm_dp_mst_add_port(struct drm_device *dev,
2213 struct drm_dp_mst_topology_mgr *mgr,
2214 struct drm_dp_mst_branch *mstb, u8 port_number)
2215 {
2216 struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
2217
2218 if (!port)
2219 return NULL;
2220
2221 kref_init(&port->topology_kref);
2222 kref_init(&port->malloc_kref);
2223 port->parent = mstb;
2224 port->port_num = port_number;
2225 port->mgr = mgr;
2226 port->aux.name = "DPMST";
2227 port->aux.dev = dev->dev;
2228 port->aux.is_remote = true;
2229
2230 /* initialize the MST downstream port's AUX crc work queue */
2231 drm_dp_remote_aux_init(&port->aux);
2232
2233 /*
2234 * Make sure the memory allocation for our parent branch stays
2235 * around until our own memory allocation is released
2236 */
2237 drm_dp_mst_get_mstb_malloc(mstb);
2238
2239 return port;
2240 }
2241
2242 static int
drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch * mstb,struct drm_device * dev,struct drm_dp_link_addr_reply_port * port_msg)2243 drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
2244 struct drm_device *dev,
2245 struct drm_dp_link_addr_reply_port *port_msg)
2246 {
2247 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2248 struct drm_dp_mst_port *port;
2249 int old_ddps = 0, ret;
2250 u8 new_pdt = DP_PEER_DEVICE_NONE;
2251 bool new_mcs = 0;
2252 bool created = false, send_link_addr = false, changed = false;
2253
2254 port = drm_dp_get_port(mstb, port_msg->port_number);
2255 if (!port) {
2256 port = drm_dp_mst_add_port(dev, mgr, mstb,
2257 port_msg->port_number);
2258 if (!port)
2259 return -ENOMEM;
2260 created = true;
2261 changed = true;
2262 } else if (!port->input && port_msg->input_port && port->connector) {
2263 /* Since port->connector can't be changed here, we create a
2264 * new port if input_port changes from 0 to 1
2265 */
2266 drm_dp_mst_topology_unlink_port(mgr, port);
2267 drm_dp_mst_topology_put_port(port);
2268 port = drm_dp_mst_add_port(dev, mgr, mstb,
2269 port_msg->port_number);
2270 if (!port)
2271 return -ENOMEM;
2272 changed = true;
2273 created = true;
2274 } else if (port->input && !port_msg->input_port) {
2275 changed = true;
2276 } else if (port->connector) {
2277 /* We're updating a port that's exposed to userspace, so do it
2278 * under lock
2279 */
2280 drm_modeset_lock(&mgr->base.lock, NULL);
2281
2282 old_ddps = port->ddps;
2283 changed = port->ddps != port_msg->ddps ||
2284 (port->ddps &&
2285 (port->ldps != port_msg->legacy_device_plug_status ||
2286 port->dpcd_rev != port_msg->dpcd_revision ||
2287 port->mcs != port_msg->mcs ||
2288 port->pdt != port_msg->peer_device_type ||
2289 port->num_sdp_stream_sinks !=
2290 port_msg->num_sdp_stream_sinks));
2291 }
2292
2293 port->input = port_msg->input_port;
2294 if (!port->input)
2295 new_pdt = port_msg->peer_device_type;
2296 new_mcs = port_msg->mcs;
2297 port->ddps = port_msg->ddps;
2298 port->ldps = port_msg->legacy_device_plug_status;
2299 port->dpcd_rev = port_msg->dpcd_revision;
2300 port->num_sdp_streams = port_msg->num_sdp_streams;
2301 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
2302
2303 /* manage mstb port lists with mgr lock - take a reference
2304 for this list */
2305 if (created) {
2306 mutex_lock(&mgr->lock);
2307 drm_dp_mst_topology_get_port(port);
2308 list_add(&port->next, &mstb->ports);
2309 mstb->num_ports++;
2310 mutex_unlock(&mgr->lock);
2311 }
2312
2313 if (old_ddps != port->ddps) {
2314 if (port->ddps) {
2315 if (!port->input) {
2316 drm_dp_send_enum_path_resources(mgr, mstb,
2317 port);
2318 }
2319 } else {
2320 port->available_pbn = 0;
2321 }
2322 }
2323
2324 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2325 if (ret == 1) {
2326 send_link_addr = true;
2327 } else if (ret < 0) {
2328 DRM_ERROR("Failed to change PDT on port %p: %d\n",
2329 port, ret);
2330 goto fail;
2331 }
2332
2333 /*
2334 * If this port wasn't just created, then we're reprobing because
2335 * we're coming out of suspend. In this case, always resend the link
2336 * address if there's an MSTB on this port
2337 */
2338 if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
2339 port->mcs)
2340 send_link_addr = true;
2341
2342 if (port->connector)
2343 drm_modeset_unlock(&mgr->base.lock);
2344 else if (!port->input)
2345 drm_dp_mst_port_add_connector(mstb, port);
2346
2347 if (send_link_addr && port->mstb) {
2348 ret = drm_dp_send_link_address(mgr, port->mstb);
2349 if (ret == 1) /* MSTB below us changed */
2350 changed = true;
2351 else if (ret < 0)
2352 goto fail_put;
2353 }
2354
2355 /* put reference to this port */
2356 drm_dp_mst_topology_put_port(port);
2357 return changed;
2358
2359 fail:
2360 drm_dp_mst_topology_unlink_port(mgr, port);
2361 if (port->connector)
2362 drm_modeset_unlock(&mgr->base.lock);
2363 fail_put:
2364 drm_dp_mst_topology_put_port(port);
2365 return ret;
2366 }
2367
2368 static void
drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch * mstb,struct drm_dp_connection_status_notify * conn_stat)2369 drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
2370 struct drm_dp_connection_status_notify *conn_stat)
2371 {
2372 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2373 struct drm_dp_mst_port *port;
2374 int old_ddps, old_input, ret, i;
2375 u8 new_pdt;
2376 bool new_mcs;
2377 bool dowork = false, create_connector = false;
2378
2379 port = drm_dp_get_port(mstb, conn_stat->port_number);
2380 if (!port)
2381 return;
2382
2383 if (port->connector) {
2384 if (!port->input && conn_stat->input_port) {
2385 /*
2386 * We can't remove a connector from an already exposed
2387 * port, so just throw the port out and make sure we
2388 * reprobe the link address of it's parent MSTB
2389 */
2390 drm_dp_mst_topology_unlink_port(mgr, port);
2391 mstb->link_address_sent = false;
2392 dowork = true;
2393 goto out;
2394 }
2395
2396 /* Locking is only needed if the port's exposed to userspace */
2397 drm_modeset_lock(&mgr->base.lock, NULL);
2398 } else if (port->input && !conn_stat->input_port) {
2399 create_connector = true;
2400 /* Reprobe link address so we get num_sdp_streams */
2401 mstb->link_address_sent = false;
2402 dowork = true;
2403 }
2404
2405 old_ddps = port->ddps;
2406 old_input = port->input;
2407 port->input = conn_stat->input_port;
2408 port->ldps = conn_stat->legacy_device_plug_status;
2409 port->ddps = conn_stat->displayport_device_plug_status;
2410
2411 if (old_ddps != port->ddps) {
2412 if (port->ddps) {
2413 dowork = true;
2414 } else {
2415 port->available_pbn = 0;
2416 }
2417 }
2418
2419 new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
2420 new_mcs = conn_stat->message_capability_status;
2421 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2422 if (ret == 1) {
2423 dowork = true;
2424 } else if (ret < 0) {
2425 DRM_ERROR("Failed to change PDT for port %p: %d\n",
2426 port, ret);
2427 dowork = false;
2428 }
2429
2430 if (!old_input && old_ddps != port->ddps && !port->ddps) {
2431 for (i = 0; i < mgr->max_payloads; i++) {
2432 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
2433 struct drm_dp_mst_port *port_validated;
2434
2435 if (!vcpi)
2436 continue;
2437
2438 port_validated =
2439 container_of(vcpi, struct drm_dp_mst_port, vcpi);
2440 port_validated =
2441 drm_dp_mst_topology_get_port_validated(mgr, port_validated);
2442 if (!port_validated) {
2443 mutex_lock(&mgr->payload_lock);
2444 vcpi->num_slots = 0;
2445 mutex_unlock(&mgr->payload_lock);
2446 } else {
2447 drm_dp_mst_topology_put_port(port_validated);
2448 }
2449 }
2450 }
2451
2452 if (port->connector)
2453 drm_modeset_unlock(&mgr->base.lock);
2454 else if (create_connector)
2455 drm_dp_mst_port_add_connector(mstb, port);
2456
2457 out:
2458 drm_dp_mst_topology_put_port(port);
2459 if (dowork)
2460 queue_work(system_long_wq, &mstb->mgr->work);
2461 }
2462
drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr * mgr,u8 lct,u8 * rad)2463 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
2464 u8 lct, u8 *rad)
2465 {
2466 struct drm_dp_mst_branch *mstb;
2467 struct drm_dp_mst_port *port;
2468 int i, ret;
2469 /* find the port by iterating down */
2470
2471 mutex_lock(&mgr->lock);
2472 mstb = mgr->mst_primary;
2473
2474 if (!mstb)
2475 goto out;
2476
2477 for (i = 0; i < lct - 1; i++) {
2478 int shift = (i % 2) ? 0 : 4;
2479 int port_num = (rad[i / 2] >> shift) & 0xf;
2480
2481 list_for_each_entry(port, &mstb->ports, next) {
2482 if (port->port_num == port_num) {
2483 mstb = port->mstb;
2484 if (!mstb) {
2485 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
2486 goto out;
2487 }
2488
2489 break;
2490 }
2491 }
2492 }
2493 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2494 if (!ret)
2495 mstb = NULL;
2496 out:
2497 mutex_unlock(&mgr->lock);
2498 return mstb;
2499 }
2500
get_mst_branch_device_by_guid_helper(struct drm_dp_mst_branch * mstb,const uint8_t * guid)2501 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
2502 struct drm_dp_mst_branch *mstb,
2503 const uint8_t *guid)
2504 {
2505 struct drm_dp_mst_branch *found_mstb;
2506 struct drm_dp_mst_port *port;
2507
2508 if (memcmp(mstb->guid, guid, 16) == 0)
2509 return mstb;
2510
2511
2512 list_for_each_entry(port, &mstb->ports, next) {
2513 if (!port->mstb)
2514 continue;
2515
2516 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
2517
2518 if (found_mstb)
2519 return found_mstb;
2520 }
2521
2522 return NULL;
2523 }
2524
2525 static struct drm_dp_mst_branch *
drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr * mgr,const uint8_t * guid)2526 drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
2527 const uint8_t *guid)
2528 {
2529 struct drm_dp_mst_branch *mstb;
2530 int ret;
2531
2532 /* find the port by iterating down */
2533 mutex_lock(&mgr->lock);
2534
2535 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
2536 if (mstb) {
2537 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2538 if (!ret)
2539 mstb = NULL;
2540 }
2541
2542 mutex_unlock(&mgr->lock);
2543 return mstb;
2544 }
2545
drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb)2546 static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2547 struct drm_dp_mst_branch *mstb)
2548 {
2549 struct drm_dp_mst_port *port;
2550 int ret;
2551 bool changed = false;
2552
2553 if (!mstb->link_address_sent) {
2554 ret = drm_dp_send_link_address(mgr, mstb);
2555 if (ret == 1)
2556 changed = true;
2557 else if (ret < 0)
2558 return ret;
2559 }
2560
2561 list_for_each_entry(port, &mstb->ports, next) {
2562 struct drm_dp_mst_branch *mstb_child = NULL;
2563
2564 if (port->input || !port->ddps)
2565 continue;
2566
2567 if (!port->available_pbn) {
2568 drm_modeset_lock(&mgr->base.lock, NULL);
2569 drm_dp_send_enum_path_resources(mgr, mstb, port);
2570 drm_modeset_unlock(&mgr->base.lock);
2571 changed = true;
2572 }
2573
2574 if (port->mstb)
2575 mstb_child = drm_dp_mst_topology_get_mstb_validated(
2576 mgr, port->mstb);
2577
2578 if (mstb_child) {
2579 ret = drm_dp_check_and_send_link_address(mgr,
2580 mstb_child);
2581 drm_dp_mst_topology_put_mstb(mstb_child);
2582 if (ret == 1)
2583 changed = true;
2584 else if (ret < 0)
2585 return ret;
2586 }
2587 }
2588
2589 return changed;
2590 }
2591
drm_dp_mst_link_probe_work(struct work_struct * work)2592 static void drm_dp_mst_link_probe_work(struct work_struct *work)
2593 {
2594 struct drm_dp_mst_topology_mgr *mgr =
2595 container_of(work, struct drm_dp_mst_topology_mgr, work);
2596 struct drm_device *dev = mgr->dev;
2597 struct drm_dp_mst_branch *mstb;
2598 int ret;
2599 bool clear_payload_id_table;
2600
2601 mutex_lock(&mgr->probe_lock);
2602
2603 mutex_lock(&mgr->lock);
2604 clear_payload_id_table = !mgr->payload_id_table_cleared;
2605 mgr->payload_id_table_cleared = true;
2606
2607 mstb = mgr->mst_primary;
2608 if (mstb) {
2609 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2610 if (!ret)
2611 mstb = NULL;
2612 }
2613 mutex_unlock(&mgr->lock);
2614 if (!mstb) {
2615 mutex_unlock(&mgr->probe_lock);
2616 return;
2617 }
2618
2619 /*
2620 * Certain branch devices seem to incorrectly report an available_pbn
2621 * of 0 on downstream sinks, even after clearing the
2622 * DP_PAYLOAD_ALLOCATE_* registers in
2623 * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
2624 * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
2625 * things work again.
2626 */
2627 if (clear_payload_id_table) {
2628 DRM_DEBUG_KMS("Clearing payload ID table\n");
2629 drm_dp_send_clear_payload_id_table(mgr, mstb);
2630 }
2631
2632 ret = drm_dp_check_and_send_link_address(mgr, mstb);
2633 drm_dp_mst_topology_put_mstb(mstb);
2634
2635 mutex_unlock(&mgr->probe_lock);
2636 if (ret)
2637 drm_kms_helper_hotplug_event(dev);
2638 }
2639
drm_dp_validate_guid(struct drm_dp_mst_topology_mgr * mgr,u8 * guid)2640 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
2641 u8 *guid)
2642 {
2643 u64 salt;
2644
2645 if (memchr_inv(guid, 0, 16))
2646 return true;
2647
2648 salt = get_jiffies_64();
2649
2650 memcpy(&guid[0], &salt, sizeof(u64));
2651 memcpy(&guid[8], &salt, sizeof(u64));
2652
2653 return false;
2654 }
2655
build_dpcd_read(struct drm_dp_sideband_msg_tx * msg,u8 port_num,u32 offset,u8 num_bytes)2656 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
2657 {
2658 struct drm_dp_sideband_msg_req_body req;
2659
2660 req.req_type = DP_REMOTE_DPCD_READ;
2661 req.u.dpcd_read.port_number = port_num;
2662 req.u.dpcd_read.dpcd_address = offset;
2663 req.u.dpcd_read.num_bytes = num_bytes;
2664 drm_dp_encode_sideband_req(&req, msg);
2665
2666 return 0;
2667 }
2668
drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr * mgr,bool up,u8 * msg,int len)2669 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
2670 bool up, u8 *msg, int len)
2671 {
2672 int ret;
2673 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
2674 int tosend, total, offset;
2675 int retries = 0;
2676
2677 retry:
2678 total = len;
2679 offset = 0;
2680 do {
2681 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
2682
2683 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
2684 &msg[offset],
2685 tosend);
2686 if (ret != tosend) {
2687 if (ret == -EIO && retries < 5) {
2688 retries++;
2689 goto retry;
2690 }
2691 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
2692
2693 return -EIO;
2694 }
2695 offset += tosend;
2696 total -= tosend;
2697 } while (total > 0);
2698 return 0;
2699 }
2700
set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr * hdr,struct drm_dp_sideband_msg_tx * txmsg)2701 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
2702 struct drm_dp_sideband_msg_tx *txmsg)
2703 {
2704 struct drm_dp_mst_branch *mstb = txmsg->dst;
2705 u8 req_type;
2706
2707 /* both msg slots are full */
2708 if (txmsg->seqno == -1) {
2709 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
2710 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
2711 return -EAGAIN;
2712 }
2713 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
2714 txmsg->seqno = mstb->last_seqno;
2715 mstb->last_seqno ^= 1;
2716 } else if (mstb->tx_slots[0] == NULL)
2717 txmsg->seqno = 0;
2718 else
2719 txmsg->seqno = 1;
2720 mstb->tx_slots[txmsg->seqno] = txmsg;
2721 }
2722
2723 req_type = txmsg->msg[0] & 0x7f;
2724 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
2725 req_type == DP_RESOURCE_STATUS_NOTIFY)
2726 hdr->broadcast = 1;
2727 else
2728 hdr->broadcast = 0;
2729 hdr->path_msg = txmsg->path_msg;
2730 hdr->lct = mstb->lct;
2731 hdr->lcr = mstb->lct - 1;
2732 if (mstb->lct > 1)
2733 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
2734 hdr->seqno = txmsg->seqno;
2735 return 0;
2736 }
2737 /*
2738 * process a single block of the next message in the sideband queue
2739 */
process_single_tx_qlock(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg,bool up)2740 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2741 struct drm_dp_sideband_msg_tx *txmsg,
2742 bool up)
2743 {
2744 u8 chunk[48];
2745 struct drm_dp_sideband_msg_hdr hdr;
2746 int len, space, idx, tosend;
2747 int ret;
2748
2749 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
2750
2751 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
2752 txmsg->seqno = -1;
2753 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
2754 }
2755
2756 /* make hdr from dst mst - for replies use seqno
2757 otherwise assign one */
2758 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
2759 if (ret < 0)
2760 return ret;
2761
2762 /* amount left to send in this message */
2763 len = txmsg->cur_len - txmsg->cur_offset;
2764
2765 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
2766 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
2767
2768 tosend = min(len, space);
2769 if (len == txmsg->cur_len)
2770 hdr.somt = 1;
2771 if (space >= len)
2772 hdr.eomt = 1;
2773
2774
2775 hdr.msg_len = tosend + 1;
2776 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
2777 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
2778 /* add crc at end */
2779 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
2780 idx += tosend + 1;
2781
2782 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
2783 if (unlikely(ret) && drm_debug_enabled(DRM_UT_DP)) {
2784 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2785
2786 drm_printf(&p, "sideband msg failed to send\n");
2787 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2788 return ret;
2789 }
2790
2791 txmsg->cur_offset += tosend;
2792 if (txmsg->cur_offset == txmsg->cur_len) {
2793 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
2794 return 1;
2795 }
2796 return 0;
2797 }
2798
process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr * mgr)2799 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
2800 {
2801 struct drm_dp_sideband_msg_tx *txmsg;
2802 int ret;
2803
2804 WARN_ON(!mutex_is_locked(&mgr->qlock));
2805
2806 /* construct a chunk from the first msg in the tx_msg queue */
2807 if (list_empty(&mgr->tx_msg_downq))
2808 return;
2809
2810 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
2811 ret = process_single_tx_qlock(mgr, txmsg, false);
2812 if (ret == 1) {
2813 /* txmsg is sent it should be in the slots now */
2814 mgr->is_waiting_for_dwn_reply = true;
2815 list_del(&txmsg->next);
2816 } else if (ret) {
2817 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
2818 mgr->is_waiting_for_dwn_reply = false;
2819 list_del(&txmsg->next);
2820 if (txmsg->seqno != -1)
2821 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
2822 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
2823 DRM_WAKEUP_ALL(&mgr->tx_waitq, &mgr->qlock);
2824 }
2825 }
2826
2827 /* called holding qlock */
process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg)2828 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2829 struct drm_dp_sideband_msg_tx *txmsg)
2830 {
2831 int ret;
2832
2833 /* construct a chunk from the first msg in the tx_msg queue */
2834 ret = process_single_tx_qlock(mgr, txmsg, true);
2835
2836 if (ret != 1)
2837 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
2838
2839 if (txmsg->seqno != -1) {
2840 WARN_ON((unsigned int)txmsg->seqno >
2841 ARRAY_SIZE(txmsg->dst->tx_slots));
2842 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
2843 }
2844 }
2845
drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_sideband_msg_tx * txmsg)2846 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
2847 struct drm_dp_sideband_msg_tx *txmsg)
2848 {
2849 mutex_lock(&mgr->qlock);
2850 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
2851
2852 if (drm_debug_enabled(DRM_UT_DP)) {
2853 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2854
2855 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2856 }
2857
2858 if (list_is_singular(&mgr->tx_msg_downq) &&
2859 !mgr->is_waiting_for_dwn_reply)
2860 process_single_down_tx_qlock(mgr);
2861 mutex_unlock(&mgr->qlock);
2862 }
2863
2864 static void
drm_dp_dump_link_address(struct drm_dp_link_address_ack_reply * reply)2865 drm_dp_dump_link_address(struct drm_dp_link_address_ack_reply *reply)
2866 {
2867 struct drm_dp_link_addr_reply_port *port_reply;
2868 int i;
2869
2870 for (i = 0; i < reply->nports; i++) {
2871 port_reply = &reply->ports[i];
2872 DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n",
2873 i,
2874 port_reply->input_port,
2875 port_reply->peer_device_type,
2876 port_reply->port_number,
2877 port_reply->dpcd_revision,
2878 port_reply->mcs,
2879 port_reply->ddps,
2880 port_reply->legacy_device_plug_status,
2881 port_reply->num_sdp_streams,
2882 port_reply->num_sdp_stream_sinks);
2883 }
2884 }
2885
drm_dp_send_link_address(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb)2886 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2887 struct drm_dp_mst_branch *mstb)
2888 {
2889 struct drm_dp_sideband_msg_tx *txmsg;
2890 struct drm_dp_link_address_ack_reply *reply;
2891 struct drm_dp_mst_port *port, *tmp;
2892 int i, len __unused, ret, port_mask = 0;
2893 bool changed = false;
2894
2895 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2896 if (!txmsg)
2897 return -ENOMEM;
2898
2899 txmsg->dst = mstb;
2900 len = build_link_address(txmsg);
2901
2902 mstb->link_address_sent = true;
2903 drm_dp_queue_down_tx(mgr, txmsg);
2904
2905 /* FIXME: Actually do some real error handling here */
2906 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2907 if (ret <= 0) {
2908 DRM_ERROR("Sending link address failed with %d\n", ret);
2909 goto out;
2910 }
2911 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2912 DRM_ERROR("link address NAK received\n");
2913 ret = -EIO;
2914 goto out;
2915 }
2916
2917 reply = &txmsg->reply.u.link_addr;
2918 DRM_DEBUG_KMS("link address reply: %d\n", reply->nports);
2919 drm_dp_dump_link_address(reply);
2920
2921 drm_dp_check_mstb_guid(mstb, reply->guid);
2922
2923 for (i = 0; i < reply->nports; i++) {
2924 port_mask |= BIT(reply->ports[i].port_number);
2925 ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev,
2926 &reply->ports[i]);
2927 if (ret == 1)
2928 changed = true;
2929 else if (ret < 0)
2930 goto out;
2931 }
2932
2933 /* Prune any ports that are currently a part of mstb in our in-memory
2934 * topology, but were not seen in this link address. Usually this
2935 * means that they were removed while the topology was out of sync,
2936 * e.g. during suspend/resume
2937 */
2938 mutex_lock(&mgr->lock);
2939 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
2940 if (port_mask & BIT(port->port_num))
2941 continue;
2942
2943 DRM_DEBUG_KMS("port %d was not in link address, removing\n",
2944 port->port_num);
2945 list_del(&port->next);
2946 drm_dp_mst_topology_put_port(port);
2947 changed = true;
2948 }
2949 mutex_unlock(&mgr->lock);
2950
2951 out:
2952 if (ret <= 0)
2953 mstb->link_address_sent = false;
2954 kfree(txmsg);
2955 return ret < 0 ? ret : changed;
2956 }
2957
drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb)2958 void drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
2959 struct drm_dp_mst_branch *mstb)
2960 {
2961 struct drm_dp_sideband_msg_tx *txmsg;
2962 int len __unused, ret;
2963
2964 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2965 if (!txmsg)
2966 return;
2967
2968 txmsg->dst = mstb;
2969 len = build_clear_payload_id_table(txmsg);
2970
2971 drm_dp_queue_down_tx(mgr, txmsg);
2972
2973 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2974 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
2975 DRM_DEBUG_KMS("clear payload table id nak received\n");
2976
2977 kfree(txmsg);
2978 }
2979
2980 static int
drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb,struct drm_dp_mst_port * port)2981 drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
2982 struct drm_dp_mst_branch *mstb,
2983 struct drm_dp_mst_port *port)
2984 {
2985 struct drm_dp_enum_path_resources_ack_reply *path_res;
2986 struct drm_dp_sideband_msg_tx *txmsg;
2987 int len __unused;
2988 int ret;
2989
2990 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2991 if (!txmsg)
2992 return -ENOMEM;
2993
2994 txmsg->dst = mstb;
2995 len = build_enum_path_resources(txmsg, port->port_num);
2996
2997 drm_dp_queue_down_tx(mgr, txmsg);
2998
2999 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3000 if (ret > 0) {
3001 path_res = &txmsg->reply.u.path_resources;
3002
3003 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3004 DRM_DEBUG_KMS("enum path resources nak received\n");
3005 } else {
3006 if (port->port_num != path_res->port_number)
3007 DRM_ERROR("got incorrect port in response\n");
3008
3009 DRM_DEBUG_KMS("enum path resources %d: %d %d\n",
3010 path_res->port_number,
3011 path_res->full_payload_bw_number,
3012 path_res->avail_payload_bw_number);
3013 port->available_pbn =
3014 path_res->avail_payload_bw_number;
3015 port->fec_capable = path_res->fec_capable;
3016 }
3017 }
3018
3019 kfree(txmsg);
3020 return 0;
3021 }
3022
drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch * mstb)3023 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
3024 {
3025 if (!mstb->port_parent)
3026 return NULL;
3027
3028 if (mstb->port_parent->mstb != mstb)
3029 return mstb->port_parent;
3030
3031 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
3032 }
3033
3034 /*
3035 * Searches upwards in the topology starting from mstb to try to find the
3036 * closest available parent of mstb that's still connected to the rest of the
3037 * topology. This can be used in order to perform operations like releasing
3038 * payloads, where the branch device which owned the payload may no longer be
3039 * around and thus would require that the payload on the last living relative
3040 * be freed instead.
3041 */
3042 static struct drm_dp_mst_branch *
drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb,int * port_num)3043 drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
3044 struct drm_dp_mst_branch *mstb,
3045 int *port_num)
3046 {
3047 struct drm_dp_mst_branch *rmstb = NULL;
3048 struct drm_dp_mst_port *found_port;
3049
3050 mutex_lock(&mgr->lock);
3051 if (!mgr->mst_primary)
3052 goto out;
3053
3054 do {
3055 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
3056 if (!found_port)
3057 break;
3058
3059 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
3060 rmstb = found_port->parent;
3061 *port_num = found_port->port_num;
3062 } else {
3063 /* Search again, starting from this parent */
3064 mstb = found_port->parent;
3065 }
3066 } while (!rmstb);
3067 out:
3068 mutex_unlock(&mgr->lock);
3069 return rmstb;
3070 }
3071
drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int id,int pbn)3072 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
3073 struct drm_dp_mst_port *port,
3074 int id,
3075 int pbn)
3076 {
3077 struct drm_dp_sideband_msg_tx *txmsg;
3078 struct drm_dp_mst_branch *mstb;
3079 int len __unused, ret, port_num;
3080 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
3081 int i;
3082
3083 port_num = port->port_num;
3084 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3085 if (!mstb) {
3086 mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
3087 port->parent,
3088 &port_num);
3089
3090 if (!mstb)
3091 return -EINVAL;
3092 }
3093
3094 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3095 if (!txmsg) {
3096 ret = -ENOMEM;
3097 goto fail_put;
3098 }
3099
3100 for (i = 0; i < port->num_sdp_streams; i++)
3101 sinks[i] = i;
3102
3103 txmsg->dst = mstb;
3104 len = build_allocate_payload(txmsg, port_num,
3105 id,
3106 pbn, port->num_sdp_streams, sinks);
3107
3108 drm_dp_queue_down_tx(mgr, txmsg);
3109
3110 /*
3111 * FIXME: there is a small chance that between getting the last
3112 * connected mstb and sending the payload message, the last connected
3113 * mstb could also be removed from the topology. In the future, this
3114 * needs to be fixed by restarting the
3115 * drm_dp_get_last_connected_port_and_mstb() search in the event of a
3116 * timeout if the topology is still connected to the system.
3117 */
3118 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3119 if (ret > 0) {
3120 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3121 ret = -EINVAL;
3122 else
3123 ret = 0;
3124 }
3125 kfree(txmsg);
3126 fail_put:
3127 drm_dp_mst_topology_put_mstb(mstb);
3128 return ret;
3129 }
3130
drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,bool power_up)3131 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
3132 struct drm_dp_mst_port *port, bool power_up)
3133 {
3134 struct drm_dp_sideband_msg_tx *txmsg;
3135 int len __unused, ret;
3136
3137 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3138 if (!port)
3139 return -EINVAL;
3140
3141 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3142 if (!txmsg) {
3143 drm_dp_mst_topology_put_port(port);
3144 return -ENOMEM;
3145 }
3146
3147 txmsg->dst = port->parent;
3148 len = build_power_updown_phy(txmsg, port->port_num, power_up);
3149 drm_dp_queue_down_tx(mgr, txmsg);
3150
3151 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
3152 if (ret > 0) {
3153 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3154 ret = -EINVAL;
3155 else
3156 ret = 0;
3157 }
3158 kfree(txmsg);
3159 drm_dp_mst_topology_put_port(port);
3160
3161 return ret;
3162 }
3163 EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
3164
drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr * mgr,int id,struct drm_dp_payload * payload)3165 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3166 int id,
3167 struct drm_dp_payload *payload)
3168 {
3169 int ret;
3170
3171 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
3172 if (ret < 0) {
3173 payload->payload_state = 0;
3174 return ret;
3175 }
3176 payload->payload_state = DP_PAYLOAD_LOCAL;
3177 return 0;
3178 }
3179
drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int id,struct drm_dp_payload * payload)3180 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3181 struct drm_dp_mst_port *port,
3182 int id,
3183 struct drm_dp_payload *payload)
3184 {
3185 int ret;
3186 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
3187 if (ret < 0)
3188 return ret;
3189 payload->payload_state = DP_PAYLOAD_REMOTE;
3190 return ret;
3191 }
3192
drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int id,struct drm_dp_payload * payload)3193 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3194 struct drm_dp_mst_port *port,
3195 int id,
3196 struct drm_dp_payload *payload)
3197 {
3198 DRM_DEBUG_KMS("\n");
3199 /* it's okay for these to fail */
3200 if (port) {
3201 drm_dp_payload_send_msg(mgr, port, id, 0);
3202 }
3203
3204 drm_dp_dpcd_write_payload(mgr, id, payload);
3205 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
3206 return 0;
3207 }
3208
drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr * mgr,int id,struct drm_dp_payload * payload)3209 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3210 int id,
3211 struct drm_dp_payload *payload)
3212 {
3213 payload->payload_state = 0;
3214 return 0;
3215 }
3216
3217 /**
3218 * drm_dp_update_payload_part1() - Execute payload update part 1
3219 * @mgr: manager to use.
3220 *
3221 * This iterates over all proposed virtual channels, and tries to
3222 * allocate space in the link for them. For 0->slots transitions,
3223 * this step just writes the VCPI to the MST device. For slots->0
3224 * transitions, this writes the updated VCPIs and removes the
3225 * remote VC payloads.
3226 *
3227 * after calling this the driver should generate ACT and payload
3228 * packets.
3229 */
drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr * mgr)3230 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
3231 {
3232 struct drm_dp_payload req_payload;
3233 struct drm_dp_mst_port *port;
3234 int i, j;
3235 int cur_slots = 1;
3236
3237 mutex_lock(&mgr->payload_lock);
3238 for (i = 0; i < mgr->max_payloads; i++) {
3239 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
3240 struct drm_dp_payload *payload = &mgr->payloads[i];
3241 bool put_port = false;
3242
3243 /* solve the current payloads - compare to the hw ones
3244 - update the hw view */
3245 req_payload.start_slot = cur_slots;
3246 if (vcpi) {
3247 port = container_of(vcpi, struct drm_dp_mst_port,
3248 vcpi);
3249
3250 /* Validated ports don't matter if we're releasing
3251 * VCPI
3252 */
3253 if (vcpi->num_slots) {
3254 port = drm_dp_mst_topology_get_port_validated(
3255 mgr, port);
3256 if (!port) {
3257 mutex_unlock(&mgr->payload_lock);
3258 return -EINVAL;
3259 }
3260 put_port = true;
3261 }
3262
3263 req_payload.num_slots = vcpi->num_slots;
3264 req_payload.vcpi = vcpi->vcpi;
3265 } else {
3266 port = NULL;
3267 req_payload.num_slots = 0;
3268 }
3269
3270 payload->start_slot = req_payload.start_slot;
3271 /* work out what is required to happen with this payload */
3272 if (payload->num_slots != req_payload.num_slots) {
3273
3274 /* need to push an update for this payload */
3275 if (req_payload.num_slots) {
3276 drm_dp_create_payload_step1(mgr, vcpi->vcpi,
3277 &req_payload);
3278 payload->num_slots = req_payload.num_slots;
3279 payload->vcpi = req_payload.vcpi;
3280
3281 } else if (payload->num_slots) {
3282 payload->num_slots = 0;
3283 drm_dp_destroy_payload_step1(mgr, port,
3284 payload->vcpi,
3285 payload);
3286 req_payload.payload_state =
3287 payload->payload_state;
3288 payload->start_slot = 0;
3289 }
3290 payload->payload_state = req_payload.payload_state;
3291 }
3292 cur_slots += req_payload.num_slots;
3293
3294 if (put_port)
3295 drm_dp_mst_topology_put_port(port);
3296 }
3297
3298 for (i = 0; i < mgr->max_payloads; /* do nothing */) {
3299 if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL) {
3300 i++;
3301 continue;
3302 }
3303
3304 DRM_DEBUG_KMS("removing payload %d\n", i);
3305 for (j = i; j < mgr->max_payloads - 1; j++) {
3306 mgr->payloads[j] = mgr->payloads[j + 1];
3307 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
3308
3309 if (mgr->proposed_vcpis[j] &&
3310 mgr->proposed_vcpis[j]->num_slots) {
3311 set_bit(j + 1, &mgr->payload_mask);
3312 } else {
3313 clear_bit(j + 1, &mgr->payload_mask);
3314 }
3315 }
3316
3317 memset(&mgr->payloads[mgr->max_payloads - 1], 0,
3318 sizeof(struct drm_dp_payload));
3319 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
3320 clear_bit(mgr->max_payloads, &mgr->payload_mask);
3321 }
3322 mutex_unlock(&mgr->payload_lock);
3323
3324 return 0;
3325 }
3326 EXPORT_SYMBOL(drm_dp_update_payload_part1);
3327
3328 /**
3329 * drm_dp_update_payload_part2() - Execute payload update part 2
3330 * @mgr: manager to use.
3331 *
3332 * This iterates over all proposed virtual channels, and tries to
3333 * allocate space in the link for them. For 0->slots transitions,
3334 * this step writes the remote VC payload commands. For slots->0
3335 * this just resets some internal state.
3336 */
drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr * mgr)3337 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
3338 {
3339 struct drm_dp_mst_port *port;
3340 int i;
3341 int ret = 0;
3342 mutex_lock(&mgr->payload_lock);
3343 for (i = 0; i < mgr->max_payloads; i++) {
3344
3345 if (!mgr->proposed_vcpis[i])
3346 continue;
3347
3348 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
3349
3350 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
3351 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
3352 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3353 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
3354 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3355 }
3356 if (ret) {
3357 mutex_unlock(&mgr->payload_lock);
3358 return ret;
3359 }
3360 }
3361 mutex_unlock(&mgr->payload_lock);
3362 return 0;
3363 }
3364 EXPORT_SYMBOL(drm_dp_update_payload_part2);
3365
drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int offset,int size,u8 * bytes)3366 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
3367 struct drm_dp_mst_port *port,
3368 int offset, int size, u8 *bytes)
3369 {
3370 int len __unused;
3371 int ret = 0;
3372 struct drm_dp_sideband_msg_tx *txmsg;
3373 struct drm_dp_mst_branch *mstb;
3374
3375 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3376 if (!mstb)
3377 return -EINVAL;
3378
3379 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3380 if (!txmsg) {
3381 ret = -ENOMEM;
3382 goto fail_put;
3383 }
3384
3385 len = build_dpcd_read(txmsg, port->port_num, offset, size);
3386 txmsg->dst = port->parent;
3387
3388 drm_dp_queue_down_tx(mgr, txmsg);
3389
3390 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3391 if (ret < 0)
3392 goto fail_free;
3393
3394 /* DPCD read should never be NACKed */
3395 if (txmsg->reply.reply_type == 1) {
3396 DRM_ERROR("mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n",
3397 mstb, port->port_num, offset, size);
3398 ret = -EIO;
3399 goto fail_free;
3400 }
3401
3402 if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) {
3403 ret = -EPROTO;
3404 goto fail_free;
3405 }
3406
3407 ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes,
3408 size);
3409 memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret);
3410
3411 fail_free:
3412 kfree(txmsg);
3413 fail_put:
3414 drm_dp_mst_topology_put_mstb(mstb);
3415
3416 return ret;
3417 }
3418
drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int offset,int size,u8 * bytes)3419 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
3420 struct drm_dp_mst_port *port,
3421 int offset, int size, u8 *bytes)
3422 {
3423 int len __unused;
3424 int ret;
3425 struct drm_dp_sideband_msg_tx *txmsg;
3426 struct drm_dp_mst_branch *mstb;
3427
3428 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3429 if (!mstb)
3430 return -EINVAL;
3431
3432 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3433 if (!txmsg) {
3434 ret = -ENOMEM;
3435 goto fail_put;
3436 }
3437
3438 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
3439 txmsg->dst = mstb;
3440
3441 drm_dp_queue_down_tx(mgr, txmsg);
3442
3443 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3444 if (ret > 0) {
3445 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3446 ret = -EIO;
3447 else
3448 ret = 0;
3449 }
3450 kfree(txmsg);
3451 fail_put:
3452 drm_dp_mst_topology_put_mstb(mstb);
3453 return ret;
3454 }
3455
drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx * msg,u8 req_type)3456 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
3457 {
3458 struct drm_dp_sideband_msg_reply_body reply;
3459
3460 reply.reply_type = DP_SIDEBAND_REPLY_ACK;
3461 reply.req_type = req_type;
3462 drm_dp_encode_sideband_reply(&reply, msg);
3463 return 0;
3464 }
3465
drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_branch * mstb,int req_type,int seqno,bool broadcast)3466 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
3467 struct drm_dp_mst_branch *mstb,
3468 int req_type, int seqno, bool broadcast)
3469 {
3470 struct drm_dp_sideband_msg_tx *txmsg;
3471
3472 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3473 if (!txmsg)
3474 return -ENOMEM;
3475
3476 txmsg->dst = mstb;
3477 txmsg->seqno = seqno;
3478 drm_dp_encode_up_ack_reply(txmsg, req_type);
3479
3480 mutex_lock(&mgr->qlock);
3481
3482 process_single_up_tx_qlock(mgr, txmsg);
3483
3484 mutex_unlock(&mgr->qlock);
3485
3486 kfree(txmsg);
3487 return 0;
3488 }
3489
drm_dp_get_vc_payload_bw(u8 dp_link_bw,u8 dp_link_count)3490 static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count)
3491 {
3492 if (dp_link_bw == 0 || dp_link_count == 0)
3493 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
3494 dp_link_bw, dp_link_count);
3495
3496 return dp_link_bw * dp_link_count / 2;
3497 }
3498
3499 /**
3500 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
3501 * @mgr: manager to set state for
3502 * @mst_state: true to enable MST on this connector - false to disable.
3503 *
3504 * This is called by the driver when it detects an MST capable device plugged
3505 * into a DP MST capable port, or when a DP MST capable device is unplugged.
3506 */
drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr * mgr,bool mst_state)3507 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
3508 {
3509 int ret = 0;
3510 int i = 0;
3511 struct drm_dp_mst_branch *mstb = NULL;
3512
3513 mutex_lock(&mgr->lock);
3514 if (mst_state == mgr->mst_state)
3515 goto out_unlock;
3516
3517 mgr->mst_state = mst_state;
3518 /* set the device into MST mode */
3519 if (mst_state) {
3520 WARN_ON(mgr->mst_primary);
3521
3522 /* get dpcd info */
3523 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
3524 if (ret != DP_RECEIVER_CAP_SIZE) {
3525 DRM_DEBUG_KMS("failed to read DPCD\n");
3526 goto out_unlock;
3527 }
3528
3529 mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1],
3530 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK);
3531 if (mgr->pbn_div == 0) {
3532 ret = -EINVAL;
3533 goto out_unlock;
3534 }
3535
3536 /* add initial branch device at LCT 1 */
3537 mstb = drm_dp_add_mst_branch_device(1, NULL);
3538 if (mstb == NULL) {
3539 ret = -ENOMEM;
3540 goto out_unlock;
3541 }
3542 mstb->mgr = mgr;
3543
3544 /* give this the main reference */
3545 mgr->mst_primary = mstb;
3546 drm_dp_mst_topology_get_mstb(mgr->mst_primary);
3547
3548 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3549 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
3550 if (ret < 0) {
3551 goto out_unlock;
3552 }
3553
3554 {
3555 struct drm_dp_payload reset_pay;
3556 reset_pay.start_slot = 0;
3557 reset_pay.num_slots = 0x3f;
3558 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
3559 }
3560
3561 queue_work(system_long_wq, &mgr->work);
3562
3563 ret = 0;
3564 } else {
3565 /* disable MST on the device */
3566 mstb = mgr->mst_primary;
3567 mgr->mst_primary = NULL;
3568 /* this can fail if the device is gone */
3569 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
3570 ret = 0;
3571 mutex_lock(&mgr->payload_lock);
3572 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
3573 mgr->payload_mask = 0;
3574 set_bit(0, &mgr->payload_mask);
3575 for (i = 0; i < mgr->max_payloads; i++) {
3576 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
3577
3578 if (vcpi) {
3579 vcpi->vcpi = 0;
3580 vcpi->num_slots = 0;
3581 }
3582 mgr->proposed_vcpis[i] = NULL;
3583 }
3584 mgr->vcpi_mask = 0;
3585 mutex_unlock(&mgr->payload_lock);
3586
3587 mgr->payload_id_table_cleared = false;
3588 }
3589
3590 out_unlock:
3591 mutex_unlock(&mgr->lock);
3592 if (mstb)
3593 drm_dp_mst_topology_put_mstb(mstb);
3594 return ret;
3595
3596 }
3597 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
3598
3599 static void
drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch * mstb)3600 drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
3601 {
3602 struct drm_dp_mst_port *port;
3603
3604 /* The link address will need to be re-sent on resume */
3605 mstb->link_address_sent = false;
3606
3607 list_for_each_entry(port, &mstb->ports, next) {
3608 /* The PBN for each port will also need to be re-probed */
3609 port->available_pbn = 0;
3610
3611 if (port->mstb)
3612 drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb);
3613 }
3614 }
3615
3616 /**
3617 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
3618 * @mgr: manager to suspend
3619 *
3620 * This function tells the MST device that we can't handle UP messages
3621 * anymore. This should stop it from sending any since we are suspended.
3622 */
drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr * mgr)3623 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
3624 {
3625 mutex_lock(&mgr->lock);
3626 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3627 DP_MST_EN | DP_UPSTREAM_IS_SRC);
3628 mutex_unlock(&mgr->lock);
3629 flush_work(&mgr->up_req_work);
3630 flush_work(&mgr->work);
3631 flush_work(&mgr->delayed_destroy_work);
3632
3633 mutex_lock(&mgr->lock);
3634 if (mgr->mst_state && mgr->mst_primary)
3635 drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary);
3636 mutex_unlock(&mgr->lock);
3637 }
3638 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
3639
3640 /**
3641 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
3642 * @mgr: manager to resume
3643 * @sync: whether or not to perform topology reprobing synchronously
3644 *
3645 * This will fetch DPCD and see if the device is still there,
3646 * if it is, it will rewrite the MSTM control bits, and return.
3647 *
3648 * If the device fails this returns -1, and the driver should do
3649 * a full MST reprobe, in case we were undocked.
3650 *
3651 * During system resume (where it is assumed that the driver will be calling
3652 * drm_atomic_helper_resume()) this function should be called beforehand with
3653 * @sync set to true. In contexts like runtime resume where the driver is not
3654 * expected to be calling drm_atomic_helper_resume(), this function should be
3655 * called with @sync set to false in order to avoid deadlocking.
3656 *
3657 * Returns: -1 if the MST topology was removed while we were suspended, 0
3658 * otherwise.
3659 */
drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr * mgr,bool sync)3660 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
3661 bool sync)
3662 {
3663 int ret;
3664 u8 guid[16];
3665
3666 mutex_lock(&mgr->lock);
3667 if (!mgr->mst_primary)
3668 goto out_fail;
3669
3670 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd,
3671 DP_RECEIVER_CAP_SIZE);
3672 if (ret != DP_RECEIVER_CAP_SIZE) {
3673 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
3674 goto out_fail;
3675 }
3676
3677 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3678 DP_MST_EN |
3679 DP_UP_REQ_EN |
3680 DP_UPSTREAM_IS_SRC);
3681 if (ret < 0) {
3682 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
3683 goto out_fail;
3684 }
3685
3686 /* Some hubs forget their guids after they resume */
3687 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
3688 if (ret != 16) {
3689 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
3690 goto out_fail;
3691 }
3692 drm_dp_check_mstb_guid(mgr->mst_primary, guid);
3693
3694 /*
3695 * For the final step of resuming the topology, we need to bring the
3696 * state of our in-memory topology back into sync with reality. So,
3697 * restart the probing process as if we're probing a new hub
3698 */
3699 queue_work(system_long_wq, &mgr->work);
3700 mutex_unlock(&mgr->lock);
3701
3702 if (sync) {
3703 DRM_DEBUG_KMS("Waiting for link probe work to finish re-syncing topology...\n");
3704 flush_work(&mgr->work);
3705 }
3706
3707 return 0;
3708
3709 out_fail:
3710 mutex_unlock(&mgr->lock);
3711 return -1;
3712 }
3713 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
3714
drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr * mgr,bool up)3715 static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
3716 {
3717 int len;
3718 u8 replyblock[32];
3719 int replylen, origlen __unused, curreply;
3720 int ret;
3721 struct drm_dp_sideband_msg_rx *msg;
3722 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
3723 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
3724
3725 len = min(mgr->max_dpcd_transaction_bytes, 16);
3726 ret = drm_dp_dpcd_read(mgr->aux, basereg,
3727 replyblock, len);
3728 if (ret != len) {
3729 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
3730 return false;
3731 }
3732 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
3733 if (!ret) {
3734 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
3735 return false;
3736 }
3737 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
3738
3739 origlen = replylen;
3740 replylen -= len;
3741 curreply = len;
3742 while (replylen > 0) {
3743 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
3744 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
3745 replyblock, len);
3746 if (ret != len) {
3747 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
3748 len, ret);
3749 return false;
3750 }
3751
3752 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
3753 if (!ret) {
3754 DRM_DEBUG_KMS("failed to build sideband msg\n");
3755 return false;
3756 }
3757
3758 curreply += len;
3759 replylen -= len;
3760 }
3761 return true;
3762 }
3763
drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr * mgr)3764 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
3765 {
3766 struct drm_dp_sideband_msg_tx *txmsg;
3767 struct drm_dp_mst_branch *mstb;
3768 struct drm_dp_sideband_msg_hdr *hdr = &mgr->down_rep_recv.initial_hdr;
3769 int slot = -1;
3770
3771 if (!drm_dp_get_one_sb_msg(mgr, false))
3772 goto clear_down_rep_recv;
3773
3774 if (!mgr->down_rep_recv.have_eomt)
3775 return 0;
3776
3777 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
3778 if (!mstb) {
3779 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
3780 hdr->lct);
3781 goto clear_down_rep_recv;
3782 }
3783
3784 /* find the message */
3785 slot = hdr->seqno;
3786 mutex_lock(&mgr->qlock);
3787 txmsg = mstb->tx_slots[slot];
3788 /* remove from slots */
3789 mutex_unlock(&mgr->qlock);
3790
3791 if (!txmsg) {
3792 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
3793 mstb, hdr->seqno, hdr->lct, hdr->rad[0],
3794 mgr->down_rep_recv.msg[0]);
3795 goto no_msg;
3796 }
3797
3798 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
3799
3800 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3801 DRM_DEBUG_KMS("Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
3802 txmsg->reply.req_type,
3803 drm_dp_mst_req_type_str(txmsg->reply.req_type),
3804 txmsg->reply.u.nak.reason,
3805 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason),
3806 txmsg->reply.u.nak.nak_data);
3807
3808 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
3809 drm_dp_mst_topology_put_mstb(mstb);
3810
3811 mutex_lock(&mgr->qlock);
3812 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
3813 mstb->tx_slots[slot] = NULL;
3814 mgr->is_waiting_for_dwn_reply = false;
3815 DRM_WAKEUP_ALL(&mgr->tx_waitq, &mgr->qlock);
3816 mutex_unlock(&mgr->qlock);
3817
3818 return 0;
3819
3820 no_msg:
3821 drm_dp_mst_topology_put_mstb(mstb);
3822 clear_down_rep_recv:
3823 mutex_lock(&mgr->qlock);
3824 mgr->is_waiting_for_dwn_reply = false;
3825 mutex_unlock(&mgr->qlock);
3826 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
3827
3828 return 0;
3829 }
3830
3831 static inline bool
drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_pending_up_req * up_req)3832 drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
3833 struct drm_dp_pending_up_req *up_req)
3834 {
3835 struct drm_dp_mst_branch *mstb = NULL;
3836 struct drm_dp_sideband_msg_req_body *msg = &up_req->msg;
3837 struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr;
3838 bool hotplug = false;
3839
3840 if (hdr->broadcast) {
3841 const u8 *guid = NULL;
3842
3843 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY)
3844 guid = msg->u.conn_stat.guid;
3845 else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
3846 guid = msg->u.resource_stat.guid;
3847
3848 if (guid)
3849 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
3850 } else {
3851 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
3852 }
3853
3854 if (!mstb) {
3855 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
3856 hdr->lct);
3857 return false;
3858 }
3859
3860 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */
3861 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) {
3862 drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat);
3863 hotplug = true;
3864 }
3865
3866 drm_dp_mst_topology_put_mstb(mstb);
3867 return hotplug;
3868 }
3869
drm_dp_mst_up_req_work(struct work_struct * work)3870 static void drm_dp_mst_up_req_work(struct work_struct *work)
3871 {
3872 struct drm_dp_mst_topology_mgr *mgr =
3873 container_of(work, struct drm_dp_mst_topology_mgr,
3874 up_req_work);
3875 struct drm_dp_pending_up_req *up_req;
3876 bool send_hotplug = false;
3877
3878 mutex_lock(&mgr->probe_lock);
3879 while (true) {
3880 mutex_lock(&mgr->up_req_lock);
3881 up_req = list_first_entry_or_null(&mgr->up_req_list,
3882 struct drm_dp_pending_up_req,
3883 next);
3884 if (up_req)
3885 list_del(&up_req->next);
3886 mutex_unlock(&mgr->up_req_lock);
3887
3888 if (!up_req)
3889 break;
3890
3891 send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req);
3892 kfree(up_req);
3893 }
3894 mutex_unlock(&mgr->probe_lock);
3895
3896 if (send_hotplug)
3897 drm_kms_helper_hotplug_event(mgr->dev);
3898 }
3899
drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr * mgr)3900 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
3901 {
3902 struct drm_dp_sideband_msg_hdr *hdr = &mgr->up_req_recv.initial_hdr;
3903 struct drm_dp_pending_up_req *up_req;
3904 bool seqno;
3905
3906 if (!drm_dp_get_one_sb_msg(mgr, true))
3907 goto out;
3908
3909 if (!mgr->up_req_recv.have_eomt)
3910 return 0;
3911
3912 up_req = kzalloc(sizeof(*up_req), GFP_KERNEL);
3913 if (!up_req) {
3914 DRM_ERROR("Not enough memory to process MST up req\n");
3915 return -ENOMEM;
3916 }
3917 INIT_LIST_HEAD(&up_req->next);
3918
3919 seqno = hdr->seqno;
3920 drm_dp_sideband_parse_req(&mgr->up_req_recv, &up_req->msg);
3921
3922 if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY &&
3923 up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) {
3924 DRM_DEBUG_KMS("Received unknown up req type, ignoring: %x\n",
3925 up_req->msg.req_type);
3926 kfree(up_req);
3927 goto out;
3928 }
3929
3930 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type,
3931 seqno, false);
3932
3933 if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
3934 const struct drm_dp_connection_status_notify *conn_stat =
3935 &up_req->msg.u.conn_stat;
3936
3937 DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
3938 conn_stat->port_number,
3939 conn_stat->legacy_device_plug_status,
3940 conn_stat->displayport_device_plug_status,
3941 conn_stat->message_capability_status,
3942 conn_stat->input_port,
3943 conn_stat->peer_device_type);
3944 } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
3945 const struct drm_dp_resource_status_notify *res_stat =
3946 &up_req->msg.u.resource_stat;
3947
3948 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n",
3949 res_stat->port_number,
3950 res_stat->available_pbn);
3951 }
3952
3953 up_req->hdr = *hdr;
3954 mutex_lock(&mgr->up_req_lock);
3955 list_add_tail(&up_req->next, &mgr->up_req_list);
3956 mutex_unlock(&mgr->up_req_lock);
3957 queue_work(system_long_wq, &mgr->up_req_work);
3958
3959 out:
3960 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
3961 return 0;
3962 }
3963
3964 /**
3965 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
3966 * @mgr: manager to notify irq for.
3967 * @esi: 4 bytes from SINK_COUNT_ESI
3968 * @handled: whether the hpd interrupt was consumed or not
3969 *
3970 * This should be called from the driver when it detects a short IRQ,
3971 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
3972 * topology manager will process the sideband messages received as a result
3973 * of this.
3974 */
drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr * mgr,u8 * esi,bool * handled)3975 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
3976 {
3977 int ret = 0;
3978 int sc;
3979 *handled = false;
3980 sc = esi[0] & 0x3f;
3981
3982 if (sc != mgr->sink_count) {
3983 mgr->sink_count = sc;
3984 *handled = true;
3985 }
3986
3987 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
3988 ret = drm_dp_mst_handle_down_rep(mgr);
3989 *handled = true;
3990 }
3991
3992 if (esi[1] & DP_UP_REQ_MSG_RDY) {
3993 ret |= drm_dp_mst_handle_up_req(mgr);
3994 *handled = true;
3995 }
3996
3997 drm_dp_mst_kick_tx(mgr);
3998 return ret;
3999 }
4000 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
4001
4002 /**
4003 * drm_dp_mst_detect_port() - get connection status for an MST port
4004 * @connector: DRM connector for this port
4005 * @ctx: The acquisition context to use for grabbing locks
4006 * @mgr: manager for this port
4007 * @port: pointer to a port
4008 *
4009 * This returns the current connection state for a port.
4010 */
4011 int
drm_dp_mst_detect_port(struct drm_connector * connector,struct drm_modeset_acquire_ctx * ctx,struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)4012 drm_dp_mst_detect_port(struct drm_connector *connector,
4013 struct drm_modeset_acquire_ctx *ctx,
4014 struct drm_dp_mst_topology_mgr *mgr,
4015 struct drm_dp_mst_port *port)
4016 {
4017 int ret;
4018
4019 /* we need to search for the port in the mgr in case it's gone */
4020 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4021 if (!port)
4022 return connector_status_disconnected;
4023
4024 ret = drm_modeset_lock(&mgr->base.lock, ctx);
4025 if (ret)
4026 goto out;
4027
4028 ret = connector_status_disconnected;
4029
4030 if (!port->ddps)
4031 goto out;
4032
4033 switch (port->pdt) {
4034 case DP_PEER_DEVICE_NONE:
4035 case DP_PEER_DEVICE_MST_BRANCHING:
4036 if (!port->mcs)
4037 ret = connector_status_connected;
4038 break;
4039
4040 case DP_PEER_DEVICE_SST_SINK:
4041 ret = connector_status_connected;
4042 /* for logical ports - cache the EDID */
4043 if (port->port_num >= 8 && !port->cached_edid) {
4044 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
4045 }
4046 break;
4047 case DP_PEER_DEVICE_DP_LEGACY_CONV:
4048 if (port->ldps)
4049 ret = connector_status_connected;
4050 break;
4051 }
4052 out:
4053 drm_dp_mst_topology_put_port(port);
4054 return ret;
4055 }
4056 EXPORT_SYMBOL(drm_dp_mst_detect_port);
4057
4058 /**
4059 * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
4060 * @mgr: manager for this port
4061 * @port: unverified pointer to a port.
4062 *
4063 * This returns whether the port supports audio or not.
4064 */
drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)4065 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
4066 struct drm_dp_mst_port *port)
4067 {
4068 bool ret = false;
4069
4070 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4071 if (!port)
4072 return ret;
4073 ret = port->has_audio;
4074 drm_dp_mst_topology_put_port(port);
4075 return ret;
4076 }
4077 EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
4078
4079 /**
4080 * drm_dp_mst_get_edid() - get EDID for an MST port
4081 * @connector: toplevel connector to get EDID for
4082 * @mgr: manager for this port
4083 * @port: unverified pointer to a port.
4084 *
4085 * This returns an EDID for the port connected to a connector,
4086 * It validates the pointer still exists so the caller doesn't require a
4087 * reference.
4088 */
drm_dp_mst_get_edid(struct drm_connector * connector,struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)4089 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4090 {
4091 struct edid *edid = NULL;
4092
4093 /* we need to search for the port in the mgr in case it's gone */
4094 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4095 if (!port)
4096 return NULL;
4097
4098 if (port->cached_edid)
4099 edid = drm_edid_duplicate(port->cached_edid);
4100 else {
4101 edid = drm_get_edid(connector, &port->aux.ddc);
4102 }
4103 port->has_audio = drm_detect_monitor_audio(edid);
4104 drm_dp_mst_topology_put_port(port);
4105 return edid;
4106 }
4107 EXPORT_SYMBOL(drm_dp_mst_get_edid);
4108
4109 /**
4110 * drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
4111 * @mgr: manager to use
4112 * @pbn: payload bandwidth to convert into slots.
4113 *
4114 * Calculate the number of VCPI slots that will be required for the given PBN
4115 * value. This function is deprecated, and should not be used in atomic
4116 * drivers.
4117 *
4118 * RETURNS:
4119 * The total slots required for this port, or error.
4120 */
drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr * mgr,int pbn)4121 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
4122 int pbn)
4123 {
4124 int num_slots;
4125
4126 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
4127
4128 /* max. time slots - one slot for MTP header */
4129 if (num_slots > 63)
4130 return -ENOSPC;
4131 return num_slots;
4132 }
4133 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
4134
drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_vcpi * vcpi,int pbn,int slots)4135 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4136 struct drm_dp_vcpi *vcpi, int pbn, int slots)
4137 {
4138 int ret;
4139
4140 /* max. time slots - one slot for MTP header */
4141 if (slots > 63)
4142 return -ENOSPC;
4143
4144 vcpi->pbn = pbn;
4145 vcpi->aligned_pbn = slots * mgr->pbn_div;
4146 vcpi->num_slots = slots;
4147
4148 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
4149 if (ret < 0)
4150 return ret;
4151 return 0;
4152 }
4153
4154 /**
4155 * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
4156 * @state: global atomic state
4157 * @mgr: MST topology manager for the port
4158 * @port: port to find vcpi slots for
4159 * @pbn: bandwidth required for the mode in PBN
4160 * @pbn_div: divider for DSC mode that takes FEC into account
4161 *
4162 * Allocates VCPI slots to @port, replacing any previous VCPI allocations it
4163 * may have had. Any atomic drivers which support MST must call this function
4164 * in their &drm_encoder_helper_funcs.atomic_check() callback to change the
4165 * current VCPI allocation for the new state, but only when
4166 * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set
4167 * to ensure compatibility with userspace applications that still use the
4168 * legacy modesetting UAPI.
4169 *
4170 * Allocations set by this function are not checked against the bandwidth
4171 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
4172 *
4173 * Additionally, it is OK to call this function multiple times on the same
4174 * @port as needed. It is not OK however, to call this function and
4175 * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
4176 *
4177 * See also:
4178 * drm_dp_atomic_release_vcpi_slots()
4179 * drm_dp_mst_atomic_check()
4180 *
4181 * Returns:
4182 * Total slots in the atomic state assigned for this port, or a negative error
4183 * code if the port no longer exists
4184 */
drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state * state,struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int pbn,int pbn_div)4185 int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
4186 struct drm_dp_mst_topology_mgr *mgr,
4187 struct drm_dp_mst_port *port, int pbn,
4188 int pbn_div)
4189 {
4190 struct drm_dp_mst_topology_state *topology_state;
4191 struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
4192 int prev_slots, prev_bw, req_slots;
4193
4194 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4195 if (IS_ERR(topology_state))
4196 return PTR_ERR(topology_state);
4197
4198 /* Find the current allocation for this port, if any */
4199 list_for_each_entry(pos, &topology_state->vcpis, next) {
4200 if (pos->port == port) {
4201 vcpi = pos;
4202 prev_slots = vcpi->vcpi;
4203 prev_bw = vcpi->pbn;
4204
4205 /*
4206 * This should never happen, unless the driver tries
4207 * releasing and allocating the same VCPI allocation,
4208 * which is an error
4209 */
4210 if (WARN_ON(!prev_slots)) {
4211 DRM_ERROR("cannot allocate and release VCPI on [MST PORT:%p] in the same state\n",
4212 port);
4213 return -EINVAL;
4214 }
4215
4216 break;
4217 }
4218 }
4219 if (!vcpi) {
4220 prev_slots = 0;
4221 prev_bw = 0;
4222 }
4223
4224 if (pbn_div <= 0)
4225 pbn_div = mgr->pbn_div;
4226
4227 req_slots = DIV_ROUND_UP(pbn, pbn_div);
4228
4229 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
4230 port->connector->base.id, port->connector->name,
4231 port, prev_slots, req_slots);
4232 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n",
4233 port->connector->base.id, port->connector->name,
4234 port, prev_bw, pbn);
4235
4236 /* Add the new allocation to the state */
4237 if (!vcpi) {
4238 vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL);
4239 if (!vcpi)
4240 return -ENOMEM;
4241
4242 drm_dp_mst_get_port_malloc(port);
4243 vcpi->port = port;
4244 list_add(&vcpi->next, &topology_state->vcpis);
4245 }
4246 vcpi->vcpi = req_slots;
4247 vcpi->pbn = pbn;
4248
4249 return req_slots;
4250 }
4251 EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
4252
4253 /**
4254 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
4255 * @state: global atomic state
4256 * @mgr: MST topology manager for the port
4257 * @port: The port to release the VCPI slots from
4258 *
4259 * Releases any VCPI slots that have been allocated to a port in the atomic
4260 * state. Any atomic drivers which support MST must call this function in
4261 * their &drm_connector_helper_funcs.atomic_check() callback when the
4262 * connector will no longer have VCPI allocated (e.g. because its CRTC was
4263 * removed) when it had VCPI allocated in the previous atomic state.
4264 *
4265 * It is OK to call this even if @port has been removed from the system.
4266 * Additionally, it is OK to call this function multiple times on the same
4267 * @port as needed. It is not OK however, to call this function and
4268 * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
4269 * phase.
4270 *
4271 * See also:
4272 * drm_dp_atomic_find_vcpi_slots()
4273 * drm_dp_mst_atomic_check()
4274 *
4275 * Returns:
4276 * 0 if all slots for this port were added back to
4277 * &drm_dp_mst_topology_state.avail_slots or negative error code
4278 */
drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state * state,struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)4279 int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
4280 struct drm_dp_mst_topology_mgr *mgr,
4281 struct drm_dp_mst_port *port)
4282 {
4283 struct drm_dp_mst_topology_state *topology_state;
4284 struct drm_dp_vcpi_allocation *pos;
4285 bool found = false;
4286
4287 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4288 if (IS_ERR(topology_state))
4289 return PTR_ERR(topology_state);
4290
4291 list_for_each_entry(pos, &topology_state->vcpis, next) {
4292 if (pos->port == port) {
4293 found = true;
4294 break;
4295 }
4296 }
4297 if (WARN_ON(!found)) {
4298 DRM_ERROR("no VCPI for [MST PORT:%p] found in mst state %p\n",
4299 port, &topology_state->base);
4300 return -EINVAL;
4301 }
4302
4303 DRM_DEBUG_ATOMIC("[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi);
4304 if (pos->vcpi) {
4305 drm_dp_mst_put_port_malloc(port);
4306 pos->vcpi = 0;
4307 }
4308
4309 return 0;
4310 }
4311 EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
4312
4313 /**
4314 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
4315 * @mgr: manager for this port
4316 * @port: port to allocate a virtual channel for.
4317 * @pbn: payload bandwidth number to request
4318 * @slots: returned number of slots for this PBN.
4319 */
drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,int pbn,int slots)4320 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4321 struct drm_dp_mst_port *port, int pbn, int slots)
4322 {
4323 int ret;
4324
4325 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4326 if (!port)
4327 return false;
4328
4329 if (slots < 0)
4330 return false;
4331
4332 if (port->vcpi.vcpi > 0) {
4333 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
4334 port->vcpi.vcpi, port->vcpi.pbn, pbn);
4335 if (pbn == port->vcpi.pbn) {
4336 drm_dp_mst_topology_put_port(port);
4337 return true;
4338 }
4339 }
4340
4341 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
4342 if (ret) {
4343 DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
4344 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
4345 goto out;
4346 }
4347 DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
4348 pbn, port->vcpi.num_slots);
4349
4350 /* Keep port allocated until its payload has been removed */
4351 drm_dp_mst_get_port_malloc(port);
4352 drm_dp_mst_topology_put_port(port);
4353 return true;
4354 out:
4355 return false;
4356 }
4357 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
4358
drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)4359 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4360 {
4361 int slots = 0;
4362 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4363 if (!port)
4364 return slots;
4365
4366 slots = port->vcpi.num_slots;
4367 drm_dp_mst_topology_put_port(port);
4368 return slots;
4369 }
4370 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
4371
4372 /**
4373 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
4374 * @mgr: manager for this port
4375 * @port: unverified pointer to a port.
4376 *
4377 * This just resets the number of slots for the ports VCPI for later programming.
4378 */
drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)4379 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4380 {
4381 /*
4382 * A port with VCPI will remain allocated until its VCPI is
4383 * released, no verified ref needed
4384 */
4385
4386 port->vcpi.num_slots = 0;
4387 }
4388 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
4389
4390 /**
4391 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
4392 * @mgr: manager for this port
4393 * @port: port to deallocate vcpi for
4394 *
4395 * This can be called unconditionally, regardless of whether
4396 * drm_dp_mst_allocate_vcpi() succeeded or not.
4397 */
drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port)4398 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4399 struct drm_dp_mst_port *port)
4400 {
4401 if (!port->vcpi.vcpi)
4402 return;
4403
4404 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
4405 port->vcpi.num_slots = 0;
4406 port->vcpi.pbn = 0;
4407 port->vcpi.aligned_pbn = 0;
4408 port->vcpi.vcpi = 0;
4409 drm_dp_mst_put_port_malloc(port);
4410 }
4411 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
4412
drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr * mgr,int id,struct drm_dp_payload * payload)4413 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
4414 int id, struct drm_dp_payload *payload)
4415 {
4416 u8 payload_alloc[3], status;
4417 int ret;
4418 int retries = 0;
4419
4420 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
4421 DP_PAYLOAD_TABLE_UPDATED);
4422
4423 payload_alloc[0] = id;
4424 payload_alloc[1] = payload->start_slot;
4425 payload_alloc[2] = payload->num_slots;
4426
4427 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
4428 if (ret != 3) {
4429 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
4430 goto fail;
4431 }
4432
4433 retry:
4434 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4435 if (ret < 0) {
4436 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
4437 goto fail;
4438 }
4439
4440 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
4441 retries++;
4442 if (retries < 20) {
4443 usleep_range(10000, 20000);
4444 goto retry;
4445 }
4446 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
4447 ret = -EINVAL;
4448 goto fail;
4449 }
4450 ret = 0;
4451 fail:
4452 return ret;
4453 }
4454
4455
4456 /**
4457 * drm_dp_check_act_status() - Check ACT handled status.
4458 * @mgr: manager to use
4459 *
4460 * Check the payload status bits in the DPCD for ACT handled completion.
4461 */
drm_dp_check_act_status(struct drm_dp_mst_topology_mgr * mgr)4462 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
4463 {
4464 u8 status;
4465 int ret;
4466 int count = 0;
4467
4468 do {
4469 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4470
4471 if (ret < 0) {
4472 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
4473 goto fail;
4474 }
4475
4476 if (status & DP_PAYLOAD_ACT_HANDLED)
4477 break;
4478 count++;
4479 udelay(100);
4480
4481 } while (count < 30);
4482
4483 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
4484 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
4485 ret = -EINVAL;
4486 goto fail;
4487 }
4488 return 0;
4489 fail:
4490 return ret;
4491 }
4492 EXPORT_SYMBOL(drm_dp_check_act_status);
4493
4494 /**
4495 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
4496 * @clock: dot clock for the mode
4497 * @bpp: bpp for the mode.
4498 * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel
4499 *
4500 * This uses the formula in the spec to calculate the PBN value for a mode.
4501 */
drm_dp_calc_pbn_mode(int clock,int bpp,bool dsc)4502 int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc)
4503 {
4504 /*
4505 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
4506 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
4507 * common multiplier to render an integer PBN for all link rate/lane
4508 * counts combinations
4509 * calculate
4510 * peak_kbps *= (1006/1000)
4511 * peak_kbps *= (64/54)
4512 * peak_kbps *= 8 convert to bytes
4513 *
4514 * If the bpp is in units of 1/16, further divide by 16. Put this
4515 * factor in the numerator rather than the denominator to avoid
4516 * integer overflow
4517 */
4518
4519 if (dsc)
4520 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006),
4521 8 * 54 * 1000 * 1000);
4522
4523 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
4524 8 * 54 * 1000 * 1000);
4525 }
4526 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
4527
4528 /* we want to kick the TX after we've ack the up/down IRQs. */
drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr * mgr)4529 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
4530 {
4531 queue_work(system_long_wq, &mgr->tx_work);
4532 }
4533
4534 #if IS_ENABLED(CONFIG_DEBUG_FS)
drm_dp_mst_dump_mstb(struct seq_file * m,struct drm_dp_mst_branch * mstb)4535 static void drm_dp_mst_dump_mstb(struct seq_file *m,
4536 struct drm_dp_mst_branch *mstb)
4537 {
4538 struct drm_dp_mst_port *port;
4539 int tabs = mstb->lct;
4540 char prefix[10];
4541 int i;
4542
4543 for (i = 0; i < tabs; i++)
4544 prefix[i] = '\t';
4545 prefix[i] = '\0';
4546
4547 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
4548 list_for_each_entry(port, &mstb->ports, next) {
4549 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);
4550 if (port->mstb)
4551 drm_dp_mst_dump_mstb(m, port->mstb);
4552 }
4553 }
4554
4555 #define DP_PAYLOAD_TABLE_SIZE 64
4556
dump_dp_payload_table(struct drm_dp_mst_topology_mgr * mgr,char * buf)4557 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
4558 char *buf)
4559 {
4560 int i;
4561
4562 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
4563 if (drm_dp_dpcd_read(mgr->aux,
4564 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
4565 &buf[i], 16) != 16)
4566 return false;
4567 }
4568 return true;
4569 }
4570
fetch_monitor_name(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_port * port,char * name,int namelen)4571 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
4572 struct drm_dp_mst_port *port, char *name,
4573 int namelen)
4574 {
4575 struct edid *mst_edid;
4576
4577 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
4578 drm_edid_get_monitor_name(mst_edid, name, namelen);
4579 }
4580
4581 /**
4582 * drm_dp_mst_dump_topology(): dump topology to seq file.
4583 * @m: seq_file to dump output to
4584 * @mgr: manager to dump current topology for.
4585 *
4586 * helper to dump MST topology to a seq file for debugfs.
4587 */
drm_dp_mst_dump_topology(struct seq_file * m,struct drm_dp_mst_topology_mgr * mgr)4588 void drm_dp_mst_dump_topology(struct seq_file *m,
4589 struct drm_dp_mst_topology_mgr *mgr)
4590 {
4591 int i;
4592 struct drm_dp_mst_port *port;
4593
4594 mutex_lock(&mgr->lock);
4595 if (mgr->mst_primary)
4596 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
4597
4598 /* dump VCPIs */
4599 mutex_unlock(&mgr->lock);
4600
4601 mutex_lock(&mgr->payload_lock);
4602 seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
4603 mgr->max_payloads);
4604
4605 for (i = 0; i < mgr->max_payloads; i++) {
4606 if (mgr->proposed_vcpis[i]) {
4607 char name[14];
4608
4609 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
4610 fetch_monitor_name(mgr, port, name, sizeof(name));
4611 seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
4612 port->port_num, port->vcpi.vcpi,
4613 port->vcpi.num_slots,
4614 (*name != 0) ? name : "Unknown");
4615 } else
4616 seq_printf(m, "vcpi %d:unused\n", i);
4617 }
4618 for (i = 0; i < mgr->max_payloads; i++) {
4619 seq_printf(m, "payload %d: %d, %d, %d\n",
4620 i,
4621 mgr->payloads[i].payload_state,
4622 mgr->payloads[i].start_slot,
4623 mgr->payloads[i].num_slots);
4624
4625
4626 }
4627 mutex_unlock(&mgr->payload_lock);
4628
4629 mutex_lock(&mgr->lock);
4630 if (mgr->mst_primary) {
4631 u8 buf[DP_PAYLOAD_TABLE_SIZE];
4632 int ret;
4633
4634 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
4635 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
4636 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
4637 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
4638 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
4639 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
4640
4641 /* dump the standard OUI branch header */
4642 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
4643 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
4644 for (i = 0x3; i < 0x8 && buf[i]; i++)
4645 seq_printf(m, "%c", buf[i]);
4646 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
4647 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
4648 if (dump_dp_payload_table(mgr, buf))
4649 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
4650 }
4651
4652 mutex_unlock(&mgr->lock);
4653
4654 }
4655 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
4656 #endif /* IS_ENABLED(CONFIG_DEBUG_FS) */
4657
drm_dp_tx_work(struct work_struct * work)4658 static void drm_dp_tx_work(struct work_struct *work)
4659 {
4660 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
4661
4662 mutex_lock(&mgr->qlock);
4663 if (!list_empty(&mgr->tx_msg_downq) && !mgr->is_waiting_for_dwn_reply)
4664 process_single_down_tx_qlock(mgr);
4665 mutex_unlock(&mgr->qlock);
4666 }
4667
4668 static inline void
drm_dp_delayed_destroy_port(struct drm_dp_mst_port * port)4669 drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port)
4670 {
4671 if (port->connector)
4672 port->mgr->cbs->destroy_connector(port->mgr, port->connector);
4673
4674 drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs);
4675 drm_dp_mst_put_port_malloc(port);
4676 }
4677
4678 static inline void
drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch * mstb)4679 drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb)
4680 {
4681 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
4682 struct drm_dp_mst_port *port, *tmp;
4683 bool wake_tx = false;
4684
4685 mutex_lock(&mgr->lock);
4686 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
4687 list_del(&port->next);
4688 drm_dp_mst_topology_put_port(port);
4689 }
4690 mutex_unlock(&mgr->lock);
4691
4692 /* drop any tx slots msg */
4693 mutex_lock(&mstb->mgr->qlock);
4694 if (mstb->tx_slots[0]) {
4695 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
4696 mstb->tx_slots[0] = NULL;
4697 wake_tx = true;
4698 }
4699 if (mstb->tx_slots[1]) {
4700 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
4701 mstb->tx_slots[1] = NULL;
4702 wake_tx = true;
4703 }
4704 if (wake_tx)
4705 DRM_WAKEUP_ALL(&mstb->mgr->tx_waitq, &mstb->mgr->qlock);
4706 mutex_unlock(&mstb->mgr->qlock);
4707
4708 drm_dp_mst_put_mstb_malloc(mstb);
4709 }
4710
drm_dp_delayed_destroy_work(struct work_struct * work)4711 static void drm_dp_delayed_destroy_work(struct work_struct *work)
4712 {
4713 struct drm_dp_mst_topology_mgr *mgr =
4714 container_of(work, struct drm_dp_mst_topology_mgr,
4715 delayed_destroy_work);
4716 bool send_hotplug = false, go_again;
4717
4718 /*
4719 * Not a regular list traverse as we have to drop the destroy
4720 * connector lock before destroying the mstb/port, to avoid AB->BA
4721 * ordering between this lock and the config mutex.
4722 */
4723 do {
4724 go_again = false;
4725
4726 for (;;) {
4727 struct drm_dp_mst_branch *mstb;
4728
4729 mutex_lock(&mgr->delayed_destroy_lock);
4730 mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list,
4731 struct drm_dp_mst_branch,
4732 destroy_next);
4733 if (mstb)
4734 list_del(&mstb->destroy_next);
4735 mutex_unlock(&mgr->delayed_destroy_lock);
4736
4737 if (!mstb)
4738 break;
4739
4740 drm_dp_delayed_destroy_mstb(mstb);
4741 go_again = true;
4742 }
4743
4744 for (;;) {
4745 struct drm_dp_mst_port *port;
4746
4747 mutex_lock(&mgr->delayed_destroy_lock);
4748 port = list_first_entry_or_null(&mgr->destroy_port_list,
4749 struct drm_dp_mst_port,
4750 next);
4751 if (port)
4752 list_del(&port->next);
4753 mutex_unlock(&mgr->delayed_destroy_lock);
4754
4755 if (!port)
4756 break;
4757
4758 drm_dp_delayed_destroy_port(port);
4759 send_hotplug = true;
4760 go_again = true;
4761 }
4762 } while (go_again);
4763
4764 if (send_hotplug)
4765 drm_kms_helper_hotplug_event(mgr->dev);
4766 }
4767
4768 static struct drm_private_state *
drm_dp_mst_duplicate_state(struct drm_private_obj * obj)4769 drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
4770 {
4771 struct drm_dp_mst_topology_state *state, *old_state =
4772 to_dp_mst_topology_state(obj->state);
4773 struct drm_dp_vcpi_allocation *pos, *vcpi;
4774
4775 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
4776 if (!state)
4777 return NULL;
4778
4779 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
4780
4781 INIT_LIST_HEAD(&state->vcpis);
4782
4783 list_for_each_entry(pos, &old_state->vcpis, next) {
4784 /* Prune leftover freed VCPI allocations */
4785 if (!pos->vcpi)
4786 continue;
4787
4788 vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL);
4789 if (!vcpi)
4790 goto fail;
4791
4792 drm_dp_mst_get_port_malloc(vcpi->port);
4793 list_add(&vcpi->next, &state->vcpis);
4794 }
4795
4796 return &state->base;
4797
4798 fail:
4799 list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) {
4800 drm_dp_mst_put_port_malloc(pos->port);
4801 kfree(pos);
4802 }
4803 kfree(state);
4804
4805 return NULL;
4806 }
4807
drm_dp_mst_destroy_state(struct drm_private_obj * obj,struct drm_private_state * state)4808 static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
4809 struct drm_private_state *state)
4810 {
4811 struct drm_dp_mst_topology_state *mst_state =
4812 to_dp_mst_topology_state(state);
4813 struct drm_dp_vcpi_allocation *pos, *tmp;
4814
4815 list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) {
4816 /* We only keep references to ports with non-zero VCPIs */
4817 if (pos->vcpi)
4818 drm_dp_mst_put_port_malloc(pos->port);
4819 kfree(pos);
4820 }
4821
4822 kfree(mst_state);
4823 }
4824
drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port * port,struct drm_dp_mst_branch * branch)4825 static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
4826 struct drm_dp_mst_branch *branch)
4827 {
4828 while (port->parent) {
4829 if (port->parent == branch)
4830 return true;
4831
4832 if (port->parent->port_parent)
4833 port = port->parent->port_parent;
4834 else
4835 break;
4836 }
4837 return false;
4838 }
4839
4840 static inline
drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch * branch,struct drm_dp_mst_topology_state * mst_state)4841 int drm_dp_mst_atomic_check_bw_limit(struct drm_dp_mst_branch *branch,
4842 struct drm_dp_mst_topology_state *mst_state)
4843 {
4844 struct drm_dp_mst_port *port;
4845 struct drm_dp_vcpi_allocation *vcpi;
4846 int pbn_limit = 0, pbn_used = 0;
4847
4848 list_for_each_entry(port, &branch->ports, next) {
4849 if (port->mstb)
4850 if (drm_dp_mst_atomic_check_bw_limit(port->mstb, mst_state))
4851 return -ENOSPC;
4852
4853 if (port->available_pbn > 0)
4854 pbn_limit = port->available_pbn;
4855 }
4856 DRM_DEBUG_ATOMIC("[MST BRANCH:%p] branch has %d PBN available\n",
4857 branch, pbn_limit);
4858
4859 list_for_each_entry(vcpi, &mst_state->vcpis, next) {
4860 if (!vcpi->pbn)
4861 continue;
4862
4863 if (drm_dp_mst_port_downstream_of_branch(vcpi->port, branch))
4864 pbn_used += vcpi->pbn;
4865 }
4866 DRM_DEBUG_ATOMIC("[MST BRANCH:%p] branch used %d PBN\n",
4867 branch, pbn_used);
4868
4869 if (pbn_used > pbn_limit) {
4870 DRM_DEBUG_ATOMIC("[MST BRANCH:%p] No available bandwidth\n",
4871 branch);
4872 return -ENOSPC;
4873 }
4874 return 0;
4875 }
4876
4877 static inline int
drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr * mgr,struct drm_dp_mst_topology_state * mst_state)4878 drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr,
4879 struct drm_dp_mst_topology_state *mst_state)
4880 {
4881 struct drm_dp_vcpi_allocation *vcpi;
4882 int avail_slots = 63, payload_count = 0;
4883
4884 list_for_each_entry(vcpi, &mst_state->vcpis, next) {
4885 /* Releasing VCPI is always OK-even if the port is gone */
4886 if (!vcpi->vcpi) {
4887 DRM_DEBUG_ATOMIC("[MST PORT:%p] releases all VCPI slots\n",
4888 vcpi->port);
4889 continue;
4890 }
4891
4892 DRM_DEBUG_ATOMIC("[MST PORT:%p] requires %d vcpi slots\n",
4893 vcpi->port, vcpi->vcpi);
4894
4895 avail_slots -= vcpi->vcpi;
4896 if (avail_slots < 0) {
4897 DRM_DEBUG_ATOMIC("[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n",
4898 vcpi->port, mst_state,
4899 avail_slots + vcpi->vcpi);
4900 return -ENOSPC;
4901 }
4902
4903 if (++payload_count > mgr->max_payloads) {
4904 DRM_DEBUG_ATOMIC("[MST MGR:%p] state %p has too many payloads (max=%d)\n",
4905 mgr, mst_state, mgr->max_payloads);
4906 return -EINVAL;
4907 }
4908 }
4909 DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
4910 mgr, mst_state, avail_slots,
4911 63 - avail_slots);
4912
4913 return 0;
4914 }
4915
4916 /**
4917 * drm_dp_mst_add_affected_dsc_crtcs
4918 * @state: Pointer to the new struct drm_dp_mst_topology_state
4919 * @mgr: MST topology manager
4920 *
4921 * Whenever there is a change in mst topology
4922 * DSC configuration would have to be recalculated
4923 * therefore we need to trigger modeset on all affected
4924 * CRTCs in that topology
4925 *
4926 * See also:
4927 * drm_dp_mst_atomic_enable_dsc()
4928 */
drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state * state,struct drm_dp_mst_topology_mgr * mgr)4929 int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr)
4930 {
4931 struct drm_dp_mst_topology_state *mst_state;
4932 struct drm_dp_vcpi_allocation *pos;
4933 struct drm_connector *connector;
4934 struct drm_connector_state *conn_state;
4935 struct drm_crtc *crtc;
4936 struct drm_crtc_state *crtc_state;
4937
4938 mst_state = drm_atomic_get_mst_topology_state(state, mgr);
4939
4940 if (IS_ERR(mst_state))
4941 return -EINVAL;
4942
4943 list_for_each_entry(pos, &mst_state->vcpis, next) {
4944
4945 connector = pos->port->connector;
4946
4947 if (!connector)
4948 return -EINVAL;
4949
4950 conn_state = drm_atomic_get_connector_state(state, connector);
4951
4952 if (IS_ERR(conn_state))
4953 return PTR_ERR(conn_state);
4954
4955 crtc = conn_state->crtc;
4956
4957 if (WARN_ON(!crtc))
4958 return -EINVAL;
4959
4960 if (!drm_dp_mst_dsc_aux_for_port(pos->port))
4961 continue;
4962
4963 crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc);
4964
4965 if (IS_ERR(crtc_state))
4966 return PTR_ERR(crtc_state);
4967
4968 DRM_DEBUG_ATOMIC("[MST MGR:%p] Setting mode_changed flag on CRTC %p\n",
4969 mgr, crtc);
4970
4971 crtc_state->mode_changed = true;
4972 }
4973 return 0;
4974 }
4975 EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs);
4976
4977 /**
4978 * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off
4979 * @state: Pointer to the new drm_atomic_state
4980 * @port: Pointer to the affected MST Port
4981 * @pbn: Newly recalculated bw required for link with DSC enabled
4982 * @pbn_div: Divider to calculate correct number of pbn per slot
4983 * @enable: Boolean flag to enable or disable DSC on the port
4984 *
4985 * This function enables DSC on the given Port
4986 * by recalculating its vcpi from pbn provided
4987 * and sets dsc_enable flag to keep track of which
4988 * ports have DSC enabled
4989 *
4990 */
drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state * state,struct drm_dp_mst_port * port,int pbn,int pbn_div,bool enable)4991 int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
4992 struct drm_dp_mst_port *port,
4993 int pbn, int pbn_div,
4994 bool enable)
4995 {
4996 struct drm_dp_mst_topology_state *mst_state;
4997 struct drm_dp_vcpi_allocation *pos;
4998 bool found = false;
4999 int vcpi = 0;
5000
5001 mst_state = drm_atomic_get_mst_topology_state(state, port->mgr);
5002
5003 if (IS_ERR(mst_state))
5004 return PTR_ERR(mst_state);
5005
5006 list_for_each_entry(pos, &mst_state->vcpis, next) {
5007 if (pos->port == port) {
5008 found = true;
5009 break;
5010 }
5011 }
5012
5013 if (!found) {
5014 DRM_DEBUG_ATOMIC("[MST PORT:%p] Couldn't find VCPI allocation in mst state %p\n",
5015 port, mst_state);
5016 return -EINVAL;
5017 }
5018
5019 if (pos->dsc_enabled == enable) {
5020 DRM_DEBUG_ATOMIC("[MST PORT:%p] DSC flag is already set to %d, returning %d VCPI slots\n",
5021 port, enable, pos->vcpi);
5022 vcpi = pos->vcpi;
5023 }
5024
5025 if (enable) {
5026 vcpi = drm_dp_atomic_find_vcpi_slots(state, port->mgr, port, pbn, pbn_div);
5027 DRM_DEBUG_ATOMIC("[MST PORT:%p] Enabling DSC flag, reallocating %d VCPI slots on the port\n",
5028 port, vcpi);
5029 if (vcpi < 0)
5030 return -EINVAL;
5031 }
5032
5033 pos->dsc_enabled = enable;
5034
5035 return vcpi;
5036 }
5037 EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc);
5038 /**
5039 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
5040 * atomic update is valid
5041 * @state: Pointer to the new &struct drm_dp_mst_topology_state
5042 *
5043 * Checks the given topology state for an atomic update to ensure that it's
5044 * valid. This includes checking whether there's enough bandwidth to support
5045 * the new VCPI allocations in the atomic update.
5046 *
5047 * Any atomic drivers supporting DP MST must make sure to call this after
5048 * checking the rest of their state in their
5049 * &drm_mode_config_funcs.atomic_check() callback.
5050 *
5051 * See also:
5052 * drm_dp_atomic_find_vcpi_slots()
5053 * drm_dp_atomic_release_vcpi_slots()
5054 *
5055 * Returns:
5056 *
5057 * 0 if the new state is valid, negative error code otherwise.
5058 */
drm_dp_mst_atomic_check(struct drm_atomic_state * state)5059 int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
5060 {
5061 struct drm_dp_mst_topology_mgr *mgr;
5062 struct drm_dp_mst_topology_state *mst_state;
5063 int i, ret = 0;
5064
5065 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
5066 if (!mgr->mst_state)
5067 continue;
5068
5069 ret = drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr, mst_state);
5070 if (ret)
5071 break;
5072 ret = drm_dp_mst_atomic_check_bw_limit(mgr->mst_primary, mst_state);
5073 if (ret)
5074 break;
5075 }
5076
5077 return ret;
5078 }
5079 EXPORT_SYMBOL(drm_dp_mst_atomic_check);
5080
5081 const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
5082 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
5083 .atomic_destroy_state = drm_dp_mst_destroy_state,
5084 };
5085 EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
5086
5087 /**
5088 * drm_atomic_get_mst_topology_state: get MST topology state
5089 *
5090 * @state: global atomic state
5091 * @mgr: MST topology manager, also the private object in this case
5092 *
5093 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
5094 * state vtable so that the private object state returned is that of a MST
5095 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
5096 * to care of the locking, so warn if don't hold the connection_mutex.
5097 *
5098 * RETURNS:
5099 *
5100 * The MST topology state or error pointer.
5101 */
drm_atomic_get_mst_topology_state(struct drm_atomic_state * state,struct drm_dp_mst_topology_mgr * mgr)5102 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
5103 struct drm_dp_mst_topology_mgr *mgr)
5104 {
5105 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
5106 }
5107 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
5108
5109 /**
5110 * drm_dp_mst_topology_mgr_init - initialise a topology manager
5111 * @mgr: manager struct to initialise
5112 * @dev: device providing this structure - for i2c addition.
5113 * @aux: DP helper aux channel to talk to this device
5114 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
5115 * @max_payloads: maximum number of payloads this GPU can source
5116 * @conn_base_id: the connector object ID the MST device is connected to.
5117 *
5118 * Return 0 for success, or negative error code on failure
5119 */
drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr * mgr,struct drm_device * dev,struct drm_dp_aux * aux,int max_dpcd_transaction_bytes,int max_payloads,int conn_base_id)5120 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
5121 struct drm_device *dev, struct drm_dp_aux *aux,
5122 int max_dpcd_transaction_bytes,
5123 int max_payloads, int conn_base_id)
5124 {
5125 struct drm_dp_mst_topology_state *mst_state;
5126
5127 mutex_init(&mgr->lock);
5128 mutex_init(&mgr->qlock);
5129 mutex_init(&mgr->payload_lock);
5130 mutex_init(&mgr->delayed_destroy_lock);
5131 mutex_init(&mgr->up_req_lock);
5132 mutex_init(&mgr->probe_lock);
5133 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5134 mutex_init(&mgr->topology_ref_history_lock);
5135 #endif
5136 INIT_LIST_HEAD(&mgr->tx_msg_downq);
5137 INIT_LIST_HEAD(&mgr->destroy_port_list);
5138 INIT_LIST_HEAD(&mgr->destroy_branch_device_list);
5139 INIT_LIST_HEAD(&mgr->up_req_list);
5140 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
5141 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
5142 INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work);
5143 INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work);
5144 DRM_INIT_WAITQUEUE(&mgr->tx_waitq, "dpmstwait");
5145 mgr->dev = dev;
5146 mgr->aux = aux;
5147 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
5148 mgr->max_payloads = max_payloads;
5149 mgr->conn_base_id = conn_base_id;
5150 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
5151 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
5152 return -EINVAL;
5153 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
5154 if (!mgr->payloads)
5155 return -ENOMEM;
5156 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
5157 if (!mgr->proposed_vcpis)
5158 return -ENOMEM;
5159 set_bit(0, &mgr->payload_mask);
5160
5161 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
5162 if (mst_state == NULL)
5163 return -ENOMEM;
5164
5165 mst_state->mgr = mgr;
5166 INIT_LIST_HEAD(&mst_state->vcpis);
5167
5168 drm_atomic_private_obj_init(dev, &mgr->base,
5169 &mst_state->base,
5170 &drm_dp_mst_topology_state_funcs);
5171
5172 return 0;
5173 }
5174 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
5175
5176 /**
5177 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
5178 * @mgr: manager to destroy
5179 */
drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr * mgr)5180 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
5181 {
5182 drm_dp_mst_topology_mgr_set_mst(mgr, false);
5183 flush_work(&mgr->work);
5184 cancel_work_sync(&mgr->delayed_destroy_work);
5185 mutex_lock(&mgr->payload_lock);
5186 kfree(mgr->payloads);
5187 mgr->payloads = NULL;
5188 kfree(mgr->proposed_vcpis);
5189 mgr->proposed_vcpis = NULL;
5190 mutex_unlock(&mgr->payload_lock);
5191 mgr->dev = NULL;
5192 mgr->aux = NULL;
5193 drm_atomic_private_obj_fini(&mgr->base);
5194 mgr->funcs = NULL;
5195
5196 DRM_DESTROY_WAITQUEUE(&mgr->tx_waitq);
5197 mutex_destroy(&mgr->delayed_destroy_lock);
5198 mutex_destroy(&mgr->payload_lock);
5199 mutex_destroy(&mgr->qlock);
5200 mutex_destroy(&mgr->lock);
5201 mutex_destroy(&mgr->up_req_lock);
5202 mutex_destroy(&mgr->probe_lock);
5203 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5204 mutex_destroy(&mgr->topology_ref_history_lock);
5205 #endif
5206 }
5207 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
5208
remote_i2c_read_ok(const struct i2c_msg msgs[],int num)5209 static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
5210 {
5211 int i;
5212
5213 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
5214 return false;
5215
5216 for (i = 0; i < num - 1; i++) {
5217 if (msgs[i].flags & I2C_M_RD ||
5218 msgs[i].len > 0xff)
5219 return false;
5220 }
5221
5222 return msgs[num - 1].flags & I2C_M_RD &&
5223 msgs[num - 1].len <= 0xff;
5224 }
5225
5226 /* I2C device */
drm_dp_mst_i2c_xfer(struct i2c_adapter * adapter,struct i2c_msg * msgs,int num)5227 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
5228 int num)
5229 {
5230 struct drm_dp_aux *aux = adapter->algo_data;
5231 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
5232 struct drm_dp_mst_branch *mstb;
5233 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5234 unsigned int i;
5235 struct drm_dp_sideband_msg_req_body msg;
5236 struct drm_dp_sideband_msg_tx *txmsg = NULL;
5237 int ret;
5238
5239 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
5240 if (!mstb)
5241 return -EREMOTEIO;
5242
5243 if (!remote_i2c_read_ok(msgs, num)) {
5244 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
5245 ret = -EIO;
5246 goto out;
5247 }
5248
5249 memset(&msg, 0, sizeof(msg));
5250 msg.req_type = DP_REMOTE_I2C_READ;
5251 msg.u.i2c_read.num_transactions = num - 1;
5252 msg.u.i2c_read.port_number = port->port_num;
5253 for (i = 0; i < num - 1; i++) {
5254 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
5255 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
5256 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
5257 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
5258 }
5259 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
5260 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
5261
5262 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5263 if (!txmsg) {
5264 ret = -ENOMEM;
5265 goto out;
5266 }
5267
5268 txmsg->dst = mstb;
5269 drm_dp_encode_sideband_req(&msg, txmsg);
5270
5271 drm_dp_queue_down_tx(mgr, txmsg);
5272
5273 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5274 if (ret > 0) {
5275
5276 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5277 ret = -EREMOTEIO;
5278 goto out;
5279 }
5280 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
5281 ret = -EIO;
5282 goto out;
5283 }
5284 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
5285 ret = num;
5286 }
5287 out:
5288 kfree(txmsg);
5289 drm_dp_mst_topology_put_mstb(mstb);
5290 return ret;
5291 }
5292
drm_dp_mst_i2c_functionality(struct i2c_adapter * adapter)5293 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
5294 {
5295 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
5296 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
5297 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
5298 I2C_FUNC_10BIT_ADDR;
5299 }
5300
5301 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
5302 .functionality = drm_dp_mst_i2c_functionality,
5303 .master_xfer = drm_dp_mst_i2c_xfer,
5304 };
5305
5306 /**
5307 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
5308 * @aux: DisplayPort AUX channel
5309 *
5310 * Returns 0 on success or a negative error code on failure.
5311 */
drm_dp_mst_register_i2c_bus(struct drm_dp_aux * aux)5312 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
5313 {
5314 aux->ddc.algo = &drm_dp_mst_i2c_algo;
5315 aux->ddc.algo_data = aux;
5316 aux->ddc.retries = 3;
5317
5318 aux->ddc.class = I2C_CLASS_DDC;
5319 aux->ddc.owner = THIS_MODULE;
5320 aux->ddc.dev.parent = aux->dev;
5321 #ifndef __NetBSD__ /* XXX of? */
5322 aux->ddc.dev.of_node = aux->dev->of_node;
5323 #endif
5324
5325 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
5326 sizeof(aux->ddc.name));
5327
5328 return i2c_add_adapter(&aux->ddc);
5329 }
5330
5331 /**
5332 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
5333 * @aux: DisplayPort AUX channel
5334 */
drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux * aux)5335 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
5336 {
5337 i2c_del_adapter(&aux->ddc);
5338 }
5339
5340 /**
5341 * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device
5342 * @port: The port to check
5343 *
5344 * A single physical MST hub object can be represented in the topology
5345 * by multiple branches, with virtual ports between those branches.
5346 *
5347 * As of DP1.4, An MST hub with internal (virtual) ports must expose
5348 * certain DPCD registers over those ports. See sections 2.6.1.1.1
5349 * and 2.6.1.1.2 of Display Port specification v1.4 for details.
5350 *
5351 * May acquire mgr->lock
5352 *
5353 * Returns:
5354 * true if the port is a virtual DP peer device, false otherwise
5355 */
drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port * port)5356 static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port)
5357 {
5358 struct drm_dp_mst_port *downstream_port;
5359
5360 if (!port || port->dpcd_rev < DP_DPCD_REV_14)
5361 return false;
5362
5363 /* Virtual DP Sink (Internal Display Panel) */
5364 if (port->port_num >= 8)
5365 return true;
5366
5367 /* DP-to-HDMI Protocol Converter */
5368 if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV &&
5369 !port->mcs &&
5370 port->ldps)
5371 return true;
5372
5373 /* DP-to-DP */
5374 mutex_lock(&port->mgr->lock);
5375 if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
5376 port->mstb &&
5377 port->mstb->num_ports == 2) {
5378 list_for_each_entry(downstream_port, &port->mstb->ports, next) {
5379 if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK &&
5380 !downstream_port->input) {
5381 mutex_unlock(&port->mgr->lock);
5382 return true;
5383 }
5384 }
5385 }
5386 mutex_unlock(&port->mgr->lock);
5387
5388 return false;
5389 }
5390
5391 /**
5392 * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
5393 * @port: The port to check. A leaf of the MST tree with an attached display.
5394 *
5395 * Depending on the situation, DSC may be enabled via the endpoint aux,
5396 * the immediately upstream aux, or the connector's physical aux.
5397 *
5398 * This is both the correct aux to read DSC_CAPABILITY and the
5399 * correct aux to write DSC_ENABLED.
5400 *
5401 * This operation can be expensive (up to four aux reads), so
5402 * the caller should cache the return.
5403 *
5404 * Returns:
5405 * NULL if DSC cannot be enabled on this port, otherwise the aux device
5406 */
drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port * port)5407 struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
5408 {
5409 struct drm_dp_mst_port *immediate_upstream_port;
5410 struct drm_dp_mst_port *fec_port;
5411 struct drm_dp_desc desc = { 0 };
5412 u8 endpoint_fec;
5413 u8 endpoint_dsc;
5414
5415 if (!port)
5416 return NULL;
5417
5418 if (port->parent->port_parent)
5419 immediate_upstream_port = port->parent->port_parent;
5420 else
5421 immediate_upstream_port = NULL;
5422
5423 fec_port = immediate_upstream_port;
5424 while (fec_port) {
5425 /*
5426 * Each physical link (i.e. not a virtual port) between the
5427 * output and the primary device must support FEC
5428 */
5429 if (!drm_dp_mst_is_virtual_dpcd(fec_port) &&
5430 !fec_port->fec_capable)
5431 return NULL;
5432
5433 fec_port = fec_port->parent->port_parent;
5434 }
5435
5436 /* DP-to-DP peer device */
5437 if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) {
5438 u8 upstream_dsc;
5439
5440 if (drm_dp_dpcd_read(&port->aux,
5441 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5442 return NULL;
5443 if (drm_dp_dpcd_read(&port->aux,
5444 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5445 return NULL;
5446 if (drm_dp_dpcd_read(&immediate_upstream_port->aux,
5447 DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
5448 return NULL;
5449
5450 /* Enpoint decompression with DP-to-DP peer device */
5451 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5452 (endpoint_fec & DP_FEC_CAPABLE) &&
5453 (upstream_dsc & 0x2) /* DSC passthrough */)
5454 return &port->aux;
5455
5456 /* Virtual DPCD decompression with DP-to-DP peer device */
5457 return &immediate_upstream_port->aux;
5458 }
5459
5460 /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */
5461 if (drm_dp_mst_is_virtual_dpcd(port))
5462 return &port->aux;
5463
5464 /*
5465 * Synaptics quirk
5466 * Applies to ports for which:
5467 * - Physical aux has Synaptics OUI
5468 * - DPv1.4 or higher
5469 * - Port is on primary branch device
5470 * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG)
5471 */
5472 if (drm_dp_read_desc(port->mgr->aux, &desc, true))
5473 return NULL;
5474
5475 if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) &&
5476 port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 &&
5477 port->parent == port->mgr->mst_primary) {
5478 u8 downstreamport;
5479
5480 if (drm_dp_dpcd_read(&port->aux, DP_DOWNSTREAMPORT_PRESENT,
5481 &downstreamport, 1) < 0)
5482 return NULL;
5483
5484 if ((downstreamport & DP_DWN_STRM_PORT_PRESENT) &&
5485 ((downstreamport & DP_DWN_STRM_PORT_TYPE_MASK)
5486 != DP_DWN_STRM_PORT_TYPE_ANALOG))
5487 return port->mgr->aux;
5488 }
5489
5490 /*
5491 * The check below verifies if the MST sink
5492 * connected to the GPU is capable of DSC -
5493 * therefore the endpoint needs to be
5494 * both DSC and FEC capable.
5495 */
5496 if (drm_dp_dpcd_read(&port->aux,
5497 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5498 return NULL;
5499 if (drm_dp_dpcd_read(&port->aux,
5500 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5501 return NULL;
5502 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5503 (endpoint_fec & DP_FEC_CAPABLE))
5504 return &port->aux;
5505
5506 return NULL;
5507 }
5508 EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);
5509