Line data Source code
1 : /*
2 : * Copyright © 2014 Red Hat
3 : *
4 : * Permission to use, copy, modify, distribute, and sell this software and its
5 : * documentation for any purpose is hereby granted without fee, provided that
6 : * the above copyright notice appear in all copies and that both that copyright
7 : * notice and this permission notice appear in supporting documentation, and
8 : * that the name of the copyright holders not be used in advertising or
9 : * publicity pertaining to distribution of the software without specific,
10 : * written prior permission. The copyright holders make no representations
11 : * about the suitability of this software for any purpose. It is provided "as
12 : * is" without express or implied warranty.
13 : *
14 : * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
15 : * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
16 : * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
17 : * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
18 : * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
19 : * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
20 : * OF THIS SOFTWARE.
21 : */
22 :
23 : #include <linux/bitfield.h>
24 : #include <linux/delay.h>
25 : #include <linux/errno.h>
26 : #include <linux/i2c.h>
27 : #include <linux/init.h>
28 : #include <linux/kernel.h>
29 : #include <linux/random.h>
30 : #include <linux/sched.h>
31 : #include <linux/seq_file.h>
32 : #include <linux/iopoll.h>
33 :
34 : #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
35 : #include <linux/stacktrace.h>
36 : #include <linux/sort.h>
37 : #include <linux/timekeeping.h>
38 : #include <linux/math64.h>
39 : #endif
40 :
41 : #include <drm/display/drm_dp_mst_helper.h>
42 : #include <drm/drm_atomic.h>
43 : #include <drm/drm_atomic_helper.h>
44 : #include <drm/drm_drv.h>
45 : #include <drm/drm_edid.h>
46 : #include <drm/drm_print.h>
47 : #include <drm/drm_probe_helper.h>
48 :
49 : #include "drm_dp_helper_internal.h"
50 : #include "drm_dp_mst_topology_internal.h"
51 :
52 : /**
53 : * DOC: dp mst helper
54 : *
55 : * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
56 : * protocol. The helpers contain a topology manager and bandwidth manager.
57 : * The helpers encapsulate the sending and received of sideband msgs.
58 : */
59 : struct drm_dp_pending_up_req {
60 : struct drm_dp_sideband_msg_hdr hdr;
61 : struct drm_dp_sideband_msg_req_body msg;
62 : struct list_head next;
63 : };
64 :
65 : static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
66 : char *buf);
67 :
68 : static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
69 :
70 : static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
71 : int id, u8 start_slot, u8 num_slots);
72 :
73 : static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
74 : struct drm_dp_mst_port *port,
75 : int offset, int size, u8 *bytes);
76 : static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
77 : struct drm_dp_mst_port *port,
78 : int offset, int size, u8 *bytes);
79 :
80 : static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
81 : struct drm_dp_mst_branch *mstb);
82 :
83 : static void
84 : drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
85 : struct drm_dp_mst_branch *mstb);
86 :
87 : static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
88 : struct drm_dp_mst_branch *mstb,
89 : struct drm_dp_mst_port *port);
90 : static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
91 : u8 *guid);
92 :
93 : static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port);
94 : static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port);
95 : static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
96 :
97 : static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
98 : struct drm_dp_mst_branch *branch);
99 :
100 : #define DBG_PREFIX "[dp_mst]"
101 :
102 : #define DP_STR(x) [DP_ ## x] = #x
103 :
104 : static const char *drm_dp_mst_req_type_str(u8 req_type)
105 : {
106 : static const char * const req_type_str[] = {
107 : DP_STR(GET_MSG_TRANSACTION_VERSION),
108 : DP_STR(LINK_ADDRESS),
109 : DP_STR(CONNECTION_STATUS_NOTIFY),
110 : DP_STR(ENUM_PATH_RESOURCES),
111 : DP_STR(ALLOCATE_PAYLOAD),
112 : DP_STR(QUERY_PAYLOAD),
113 : DP_STR(RESOURCE_STATUS_NOTIFY),
114 : DP_STR(CLEAR_PAYLOAD_ID_TABLE),
115 : DP_STR(REMOTE_DPCD_READ),
116 : DP_STR(REMOTE_DPCD_WRITE),
117 : DP_STR(REMOTE_I2C_READ),
118 : DP_STR(REMOTE_I2C_WRITE),
119 : DP_STR(POWER_UP_PHY),
120 : DP_STR(POWER_DOWN_PHY),
121 : DP_STR(SINK_EVENT_NOTIFY),
122 : DP_STR(QUERY_STREAM_ENC_STATUS),
123 : };
124 :
125 0 : if (req_type >= ARRAY_SIZE(req_type_str) ||
126 0 : !req_type_str[req_type])
127 : return "unknown";
128 :
129 : return req_type_str[req_type];
130 : }
131 :
132 : #undef DP_STR
133 : #define DP_STR(x) [DP_NAK_ ## x] = #x
134 :
135 : static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
136 : {
137 : static const char * const nak_reason_str[] = {
138 : DP_STR(WRITE_FAILURE),
139 : DP_STR(INVALID_READ),
140 : DP_STR(CRC_FAILURE),
141 : DP_STR(BAD_PARAM),
142 : DP_STR(DEFER),
143 : DP_STR(LINK_FAILURE),
144 : DP_STR(NO_RESOURCES),
145 : DP_STR(DPCD_FAIL),
146 : DP_STR(I2C_NAK),
147 : DP_STR(ALLOCATE_FAIL),
148 : };
149 :
150 0 : if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
151 0 : !nak_reason_str[nak_reason])
152 : return "unknown";
153 :
154 : return nak_reason_str[nak_reason];
155 : }
156 :
157 : #undef DP_STR
158 : #define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x
159 :
160 : static const char *drm_dp_mst_sideband_tx_state_str(int state)
161 : {
162 : static const char * const sideband_reason_str[] = {
163 : DP_STR(QUEUED),
164 : DP_STR(START_SEND),
165 : DP_STR(SENT),
166 : DP_STR(RX),
167 : DP_STR(TIMEOUT),
168 : };
169 :
170 0 : if (state >= ARRAY_SIZE(sideband_reason_str) ||
171 0 : !sideband_reason_str[state])
172 : return "unknown";
173 :
174 : return sideband_reason_str[state];
175 : }
176 :
177 : static int
178 0 : drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len)
179 : {
180 : int i;
181 : u8 unpacked_rad[16];
182 :
183 0 : for (i = 0; i < lct; i++) {
184 0 : if (i % 2)
185 0 : unpacked_rad[i] = rad[i / 2] >> 4;
186 : else
187 0 : unpacked_rad[i] = rad[i / 2] & BIT_MASK(4);
188 : }
189 :
190 : /* TODO: Eventually add something to printk so we can format the rad
191 : * like this: 1.2.3
192 : */
193 0 : return snprintf(out, len, "%*phC", lct, unpacked_rad);
194 : }
195 :
196 : /* sideband msg handling */
197 0 : static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
198 : {
199 0 : u8 bitmask = 0x80;
200 0 : u8 bitshift = 7;
201 0 : u8 array_index = 0;
202 0 : int number_of_bits = num_nibbles * 4;
203 0 : u8 remainder = 0;
204 :
205 0 : while (number_of_bits != 0) {
206 0 : number_of_bits--;
207 0 : remainder <<= 1;
208 0 : remainder |= (data[array_index] & bitmask) >> bitshift;
209 0 : bitmask >>= 1;
210 0 : bitshift--;
211 0 : if (bitmask == 0) {
212 0 : bitmask = 0x80;
213 0 : bitshift = 7;
214 0 : array_index++;
215 : }
216 0 : if ((remainder & 0x10) == 0x10)
217 0 : remainder ^= 0x13;
218 : }
219 :
220 : number_of_bits = 4;
221 0 : while (number_of_bits != 0) {
222 0 : number_of_bits--;
223 0 : remainder <<= 1;
224 0 : if ((remainder & 0x10) != 0)
225 0 : remainder ^= 0x13;
226 : }
227 :
228 0 : return remainder;
229 : }
230 :
231 0 : static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
232 : {
233 0 : u8 bitmask = 0x80;
234 0 : u8 bitshift = 7;
235 0 : u8 array_index = 0;
236 0 : int number_of_bits = number_of_bytes * 8;
237 0 : u16 remainder = 0;
238 :
239 0 : while (number_of_bits != 0) {
240 0 : number_of_bits--;
241 0 : remainder <<= 1;
242 0 : remainder |= (data[array_index] & bitmask) >> bitshift;
243 0 : bitmask >>= 1;
244 0 : bitshift--;
245 0 : if (bitmask == 0) {
246 0 : bitmask = 0x80;
247 0 : bitshift = 7;
248 0 : array_index++;
249 : }
250 0 : if ((remainder & 0x100) == 0x100)
251 0 : remainder ^= 0xd5;
252 : }
253 :
254 : number_of_bits = 8;
255 0 : while (number_of_bits != 0) {
256 0 : number_of_bits--;
257 0 : remainder <<= 1;
258 0 : if ((remainder & 0x100) != 0)
259 0 : remainder ^= 0xd5;
260 : }
261 :
262 0 : return remainder & 0xff;
263 : }
264 : static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
265 : {
266 0 : u8 size = 3;
267 :
268 0 : size += (hdr->lct / 2);
269 : return size;
270 : }
271 :
272 0 : static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
273 : u8 *buf, int *len)
274 : {
275 0 : int idx = 0;
276 : int i;
277 : u8 crc4;
278 :
279 0 : buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
280 0 : for (i = 0; i < (hdr->lct / 2); i++)
281 0 : buf[idx++] = hdr->rad[i];
282 0 : buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
283 0 : (hdr->msg_len & 0x3f);
284 0 : buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
285 :
286 0 : crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
287 0 : buf[idx - 1] |= (crc4 & 0xf);
288 :
289 0 : *len = idx;
290 0 : }
291 :
292 0 : static bool drm_dp_decode_sideband_msg_hdr(const struct drm_dp_mst_topology_mgr *mgr,
293 : 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 :
301 0 : if (buf[0] == 0)
302 : return false;
303 0 : len = 3;
304 0 : len += ((buf[0] & 0xf0) >> 4) / 2;
305 0 : if (len > buflen)
306 : return false;
307 0 : crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
308 :
309 0 : if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
310 0 : drm_dbg_kms(mgr->dev, "crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
311 : return false;
312 : }
313 :
314 0 : hdr->lct = (buf[0] & 0xf0) >> 4;
315 0 : hdr->lcr = (buf[0] & 0xf);
316 0 : idx = 1;
317 0 : for (i = 0; i < (hdr->lct / 2); i++)
318 0 : hdr->rad[i] = buf[idx++];
319 0 : hdr->broadcast = (buf[idx] >> 7) & 0x1;
320 0 : hdr->path_msg = (buf[idx] >> 6) & 0x1;
321 0 : hdr->msg_len = buf[idx] & 0x3f;
322 0 : idx++;
323 0 : hdr->somt = (buf[idx] >> 7) & 0x1;
324 0 : hdr->eomt = (buf[idx] >> 6) & 0x1;
325 0 : hdr->seqno = (buf[idx] >> 4) & 0x1;
326 0 : idx++;
327 0 : *hdrlen = idx;
328 : return true;
329 : }
330 :
331 : void
332 27 : drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
333 : struct drm_dp_sideband_msg_tx *raw)
334 : {
335 27 : int idx = 0;
336 : int i;
337 27 : u8 *buf = raw->msg;
338 :
339 27 : buf[idx++] = req->req_type & 0x7f;
340 :
341 27 : switch (req->req_type) {
342 : case DP_ENUM_PATH_RESOURCES:
343 : case DP_POWER_DOWN_PHY:
344 : case DP_POWER_UP_PHY:
345 3 : buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
346 3 : idx++;
347 3 : break;
348 : case DP_ALLOCATE_PAYLOAD:
349 8 : buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
350 4 : (req->u.allocate_payload.number_sdp_streams & 0xf);
351 4 : idx++;
352 4 : buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
353 4 : idx++;
354 4 : buf[idx] = (req->u.allocate_payload.pbn >> 8);
355 4 : idx++;
356 4 : buf[idx] = (req->u.allocate_payload.pbn & 0xff);
357 4 : idx++;
358 5 : for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
359 2 : buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
360 1 : (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
361 1 : idx++;
362 : }
363 4 : if (req->u.allocate_payload.number_sdp_streams & 1) {
364 1 : i = req->u.allocate_payload.number_sdp_streams - 1;
365 1 : buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
366 1 : idx++;
367 : }
368 : break;
369 : case DP_QUERY_PAYLOAD:
370 2 : buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
371 2 : idx++;
372 2 : buf[idx] = (req->u.query_payload.vcpi & 0x7f);
373 2 : idx++;
374 2 : break;
375 : case DP_REMOTE_DPCD_READ:
376 3 : buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
377 3 : buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
378 3 : idx++;
379 3 : buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
380 3 : idx++;
381 3 : buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
382 3 : idx++;
383 3 : buf[idx] = (req->u.dpcd_read.num_bytes);
384 3 : idx++;
385 3 : break;
386 :
387 : case DP_REMOTE_DPCD_WRITE:
388 3 : buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
389 3 : buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
390 3 : idx++;
391 3 : buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
392 3 : idx++;
393 3 : buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
394 3 : idx++;
395 3 : buf[idx] = (req->u.dpcd_write.num_bytes);
396 3 : idx++;
397 3 : memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
398 3 : idx += req->u.dpcd_write.num_bytes;
399 3 : break;
400 : case DP_REMOTE_I2C_READ:
401 3 : buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
402 3 : buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
403 3 : idx++;
404 6 : for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
405 3 : buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
406 3 : idx++;
407 3 : buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
408 3 : idx++;
409 3 : memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
410 3 : idx += req->u.i2c_read.transactions[i].num_bytes;
411 :
412 3 : buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
413 3 : buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
414 3 : idx++;
415 : }
416 3 : buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
417 3 : idx++;
418 3 : buf[idx] = (req->u.i2c_read.num_bytes_read);
419 3 : idx++;
420 3 : break;
421 :
422 : case DP_REMOTE_I2C_WRITE:
423 3 : buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
424 3 : idx++;
425 3 : buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
426 3 : idx++;
427 3 : buf[idx] = (req->u.i2c_write.num_bytes);
428 3 : idx++;
429 3 : memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
430 3 : idx += req->u.i2c_write.num_bytes;
431 3 : break;
432 : case DP_QUERY_STREAM_ENC_STATUS: {
433 : const struct drm_dp_query_stream_enc_status *msg;
434 :
435 6 : msg = &req->u.enc_status;
436 6 : buf[idx] = msg->stream_id;
437 6 : idx++;
438 6 : memcpy(&buf[idx], msg->client_id, sizeof(msg->client_id));
439 6 : idx += sizeof(msg->client_id);
440 6 : buf[idx] = 0;
441 6 : buf[idx] |= FIELD_PREP(GENMASK(1, 0), msg->stream_event);
442 6 : buf[idx] |= msg->valid_stream_event ? BIT(2) : 0;
443 6 : buf[idx] |= FIELD_PREP(GENMASK(4, 3), msg->stream_behavior);
444 6 : buf[idx] |= msg->valid_stream_behavior ? BIT(5) : 0;
445 6 : idx++;
446 : }
447 6 : break;
448 : }
449 27 : raw->cur_len = idx;
450 27 : }
451 : EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req);
452 :
453 : /* Decode a sideband request we've encoded, mainly used for debugging */
454 : int
455 27 : drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
456 : struct drm_dp_sideband_msg_req_body *req)
457 : {
458 27 : const u8 *buf = raw->msg;
459 27 : int i, idx = 0;
460 :
461 27 : req->req_type = buf[idx++] & 0x7f;
462 27 : switch (req->req_type) {
463 : case DP_ENUM_PATH_RESOURCES:
464 : case DP_POWER_DOWN_PHY:
465 : case DP_POWER_UP_PHY:
466 3 : req->u.port_num.port_number = (buf[idx] >> 4) & 0xf;
467 3 : break;
468 : case DP_ALLOCATE_PAYLOAD:
469 : {
470 4 : struct drm_dp_allocate_payload *a =
471 : &req->u.allocate_payload;
472 :
473 4 : a->number_sdp_streams = buf[idx] & 0xf;
474 4 : a->port_number = (buf[idx] >> 4) & 0xf;
475 :
476 4 : WARN_ON(buf[++idx] & 0x80);
477 4 : a->vcpi = buf[idx] & 0x7f;
478 :
479 4 : a->pbn = buf[++idx] << 8;
480 4 : a->pbn |= buf[++idx];
481 :
482 4 : idx++;
483 7 : for (i = 0; i < a->number_sdp_streams; i++) {
484 3 : a->sdp_stream_sink[i] =
485 3 : (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf;
486 : }
487 : }
488 : break;
489 : case DP_QUERY_PAYLOAD:
490 2 : req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf;
491 2 : WARN_ON(buf[++idx] & 0x80);
492 2 : req->u.query_payload.vcpi = buf[idx] & 0x7f;
493 2 : break;
494 : case DP_REMOTE_DPCD_READ:
495 : {
496 3 : struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read;
497 :
498 3 : r->port_number = (buf[idx] >> 4) & 0xf;
499 :
500 3 : r->dpcd_address = (buf[idx] << 16) & 0xf0000;
501 3 : r->dpcd_address |= (buf[++idx] << 8) & 0xff00;
502 3 : r->dpcd_address |= buf[++idx] & 0xff;
503 :
504 3 : r->num_bytes = buf[++idx];
505 : }
506 3 : break;
507 : case DP_REMOTE_DPCD_WRITE:
508 : {
509 3 : struct drm_dp_remote_dpcd_write *w =
510 : &req->u.dpcd_write;
511 :
512 3 : w->port_number = (buf[idx] >> 4) & 0xf;
513 :
514 3 : w->dpcd_address = (buf[idx] << 16) & 0xf0000;
515 3 : w->dpcd_address |= (buf[++idx] << 8) & 0xff00;
516 3 : w->dpcd_address |= buf[++idx] & 0xff;
517 :
518 3 : w->num_bytes = buf[++idx];
519 :
520 3 : w->bytes = kmemdup(&buf[++idx], w->num_bytes,
521 : GFP_KERNEL);
522 3 : if (!w->bytes)
523 : return -ENOMEM;
524 : }
525 : break;
526 : case DP_REMOTE_I2C_READ:
527 : {
528 3 : struct drm_dp_remote_i2c_read *r = &req->u.i2c_read;
529 : struct drm_dp_remote_i2c_read_tx *tx;
530 3 : bool failed = false;
531 :
532 3 : r->num_transactions = buf[idx] & 0x3;
533 3 : r->port_number = (buf[idx] >> 4) & 0xf;
534 6 : for (i = 0; i < r->num_transactions; i++) {
535 3 : tx = &r->transactions[i];
536 :
537 3 : tx->i2c_dev_id = buf[++idx] & 0x7f;
538 3 : tx->num_bytes = buf[++idx];
539 3 : tx->bytes = kmemdup(&buf[++idx],
540 : tx->num_bytes,
541 : GFP_KERNEL);
542 3 : if (!tx->bytes) {
543 : failed = true;
544 : break;
545 : }
546 3 : idx += tx->num_bytes;
547 3 : tx->no_stop_bit = (buf[idx] >> 5) & 0x1;
548 3 : tx->i2c_transaction_delay = buf[idx] & 0xf;
549 : }
550 :
551 3 : if (failed) {
552 0 : for (i = 0; i < r->num_transactions; i++) {
553 0 : tx = &r->transactions[i];
554 0 : kfree(tx->bytes);
555 : }
556 : return -ENOMEM;
557 : }
558 :
559 3 : r->read_i2c_device_id = buf[++idx] & 0x7f;
560 3 : r->num_bytes_read = buf[++idx];
561 : }
562 3 : break;
563 : case DP_REMOTE_I2C_WRITE:
564 : {
565 3 : struct drm_dp_remote_i2c_write *w = &req->u.i2c_write;
566 :
567 3 : w->port_number = (buf[idx] >> 4) & 0xf;
568 3 : w->write_i2c_device_id = buf[++idx] & 0x7f;
569 3 : w->num_bytes = buf[++idx];
570 3 : w->bytes = kmemdup(&buf[++idx], w->num_bytes,
571 : GFP_KERNEL);
572 3 : if (!w->bytes)
573 : return -ENOMEM;
574 : }
575 : break;
576 : case DP_QUERY_STREAM_ENC_STATUS:
577 6 : req->u.enc_status.stream_id = buf[idx++];
578 48 : for (i = 0; i < sizeof(req->u.enc_status.client_id); i++)
579 42 : req->u.enc_status.client_id[i] = buf[idx++];
580 :
581 6 : req->u.enc_status.stream_event = FIELD_GET(GENMASK(1, 0),
582 : buf[idx]);
583 6 : req->u.enc_status.valid_stream_event = FIELD_GET(BIT(2),
584 : buf[idx]);
585 6 : req->u.enc_status.stream_behavior = FIELD_GET(GENMASK(4, 3),
586 : buf[idx]);
587 6 : req->u.enc_status.valid_stream_behavior = FIELD_GET(BIT(5),
588 : buf[idx]);
589 6 : break;
590 : }
591 :
592 : return 0;
593 : }
594 : EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req);
595 :
596 : void
597 0 : drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req,
598 : int indent, struct drm_printer *printer)
599 : {
600 : int i;
601 :
602 : #define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__)
603 0 : if (req->req_type == DP_LINK_ADDRESS) {
604 : /* No contents to print */
605 0 : P("type=%s\n", drm_dp_mst_req_type_str(req->req_type));
606 0 : return;
607 : }
608 :
609 0 : P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type));
610 0 : indent++;
611 :
612 0 : switch (req->req_type) {
613 : case DP_ENUM_PATH_RESOURCES:
614 : case DP_POWER_DOWN_PHY:
615 : case DP_POWER_UP_PHY:
616 0 : P("port=%d\n", req->u.port_num.port_number);
617 0 : break;
618 : case DP_ALLOCATE_PAYLOAD:
619 0 : P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n",
620 : req->u.allocate_payload.port_number,
621 : req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn,
622 : req->u.allocate_payload.number_sdp_streams,
623 : req->u.allocate_payload.number_sdp_streams,
624 : req->u.allocate_payload.sdp_stream_sink);
625 0 : break;
626 : case DP_QUERY_PAYLOAD:
627 0 : P("port=%d vcpi=%d\n",
628 : req->u.query_payload.port_number,
629 : req->u.query_payload.vcpi);
630 0 : break;
631 : case DP_REMOTE_DPCD_READ:
632 0 : P("port=%d dpcd_addr=%05x len=%d\n",
633 : req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address,
634 : req->u.dpcd_read.num_bytes);
635 0 : break;
636 : case DP_REMOTE_DPCD_WRITE:
637 0 : P("port=%d addr=%05x len=%d: %*ph\n",
638 : req->u.dpcd_write.port_number,
639 : req->u.dpcd_write.dpcd_address,
640 : req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes,
641 : req->u.dpcd_write.bytes);
642 0 : break;
643 : case DP_REMOTE_I2C_READ:
644 0 : P("port=%d num_tx=%d id=%d size=%d:\n",
645 : req->u.i2c_read.port_number,
646 : req->u.i2c_read.num_transactions,
647 : req->u.i2c_read.read_i2c_device_id,
648 : req->u.i2c_read.num_bytes_read);
649 :
650 0 : indent++;
651 0 : for (i = 0; i < req->u.i2c_read.num_transactions; i++) {
652 0 : const struct drm_dp_remote_i2c_read_tx *rtx =
653 : &req->u.i2c_read.transactions[i];
654 :
655 0 : P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n",
656 : i, rtx->i2c_dev_id, rtx->num_bytes,
657 : rtx->no_stop_bit, rtx->i2c_transaction_delay,
658 : rtx->num_bytes, rtx->bytes);
659 : }
660 : break;
661 : case DP_REMOTE_I2C_WRITE:
662 0 : P("port=%d id=%d size=%d: %*ph\n",
663 : req->u.i2c_write.port_number,
664 : req->u.i2c_write.write_i2c_device_id,
665 : req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes,
666 : req->u.i2c_write.bytes);
667 0 : break;
668 : case DP_QUERY_STREAM_ENC_STATUS:
669 0 : P("stream_id=%u client_id=%*ph stream_event=%x "
670 : "valid_event=%d stream_behavior=%x valid_behavior=%d",
671 : req->u.enc_status.stream_id,
672 : (int)ARRAY_SIZE(req->u.enc_status.client_id),
673 : req->u.enc_status.client_id, req->u.enc_status.stream_event,
674 : req->u.enc_status.valid_stream_event,
675 : req->u.enc_status.stream_behavior,
676 : req->u.enc_status.valid_stream_behavior);
677 0 : break;
678 : default:
679 0 : P("???\n");
680 0 : break;
681 : }
682 : #undef P
683 : }
684 : EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body);
685 :
686 : static inline void
687 0 : drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p,
688 : const struct drm_dp_sideband_msg_tx *txmsg)
689 : {
690 : struct drm_dp_sideband_msg_req_body req;
691 : char buf[64];
692 : int ret;
693 : int i;
694 :
695 0 : drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf,
696 : sizeof(buf));
697 0 : drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n",
698 0 : txmsg->cur_offset, txmsg->cur_len, txmsg->seqno,
699 : drm_dp_mst_sideband_tx_state_str(txmsg->state),
700 0 : txmsg->path_msg, buf);
701 :
702 0 : ret = drm_dp_decode_sideband_req(txmsg, &req);
703 0 : if (ret) {
704 0 : drm_printf(p, "<failed to decode sideband req: %d>\n", ret);
705 0 : return;
706 : }
707 0 : drm_dp_dump_sideband_msg_req_body(&req, 1, p);
708 :
709 0 : switch (req.req_type) {
710 : case DP_REMOTE_DPCD_WRITE:
711 0 : kfree(req.u.dpcd_write.bytes);
712 0 : break;
713 : case DP_REMOTE_I2C_READ:
714 0 : for (i = 0; i < req.u.i2c_read.num_transactions; i++)
715 0 : kfree(req.u.i2c_read.transactions[i].bytes);
716 : break;
717 : case DP_REMOTE_I2C_WRITE:
718 0 : kfree(req.u.i2c_write.bytes);
719 0 : break;
720 : }
721 : }
722 :
723 : static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
724 : {
725 : u8 crc4;
726 :
727 0 : crc4 = drm_dp_msg_data_crc4(msg, len);
728 0 : msg[len] = crc4;
729 : }
730 :
731 : static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
732 : struct drm_dp_sideband_msg_tx *raw)
733 : {
734 0 : int idx = 0;
735 0 : u8 *buf = raw->msg;
736 :
737 0 : buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
738 :
739 0 : raw->cur_len = idx;
740 : }
741 :
742 0 : static int drm_dp_sideband_msg_set_header(struct drm_dp_sideband_msg_rx *msg,
743 : struct drm_dp_sideband_msg_hdr *hdr,
744 : u8 hdrlen)
745 : {
746 : /*
747 : * ignore out-of-order messages or messages that are part of a
748 : * failed transaction
749 : */
750 0 : if (!hdr->somt && !msg->have_somt)
751 : return false;
752 :
753 : /* get length contained in this portion */
754 0 : msg->curchunk_idx = 0;
755 0 : msg->curchunk_len = hdr->msg_len;
756 0 : msg->curchunk_hdrlen = hdrlen;
757 :
758 : /* we have already gotten an somt - don't bother parsing */
759 0 : if (hdr->somt && msg->have_somt)
760 : return false;
761 :
762 0 : if (hdr->somt) {
763 0 : memcpy(&msg->initial_hdr, hdr,
764 : sizeof(struct drm_dp_sideband_msg_hdr));
765 0 : msg->have_somt = true;
766 : }
767 0 : if (hdr->eomt)
768 0 : msg->have_eomt = true;
769 :
770 : return true;
771 : }
772 :
773 : /* this adds a chunk of msg to the builder to get the final msg */
774 0 : static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx *msg,
775 : u8 *replybuf, u8 replybuflen)
776 : {
777 : u8 crc4;
778 :
779 0 : memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
780 0 : msg->curchunk_idx += replybuflen;
781 :
782 0 : if (msg->curchunk_idx >= msg->curchunk_len) {
783 : /* do CRC */
784 0 : crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
785 0 : if (crc4 != msg->chunk[msg->curchunk_len - 1])
786 0 : print_hex_dump(KERN_DEBUG, "wrong crc",
787 : DUMP_PREFIX_NONE, 16, 1,
788 : msg->chunk, msg->curchunk_len, false);
789 : /* copy chunk into bigger msg */
790 0 : memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
791 0 : msg->curlen += msg->curchunk_len - 1;
792 : }
793 0 : return true;
794 : }
795 :
796 0 : static bool drm_dp_sideband_parse_link_address(const struct drm_dp_mst_topology_mgr *mgr,
797 : struct drm_dp_sideband_msg_rx *raw,
798 : struct drm_dp_sideband_msg_reply_body *repmsg)
799 : {
800 0 : int idx = 1;
801 : int i;
802 :
803 0 : memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
804 0 : idx += 16;
805 0 : repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
806 0 : idx++;
807 0 : if (idx > raw->curlen)
808 : goto fail_len;
809 0 : for (i = 0; i < repmsg->u.link_addr.nports; i++) {
810 0 : if (raw->msg[idx] & 0x80)
811 0 : repmsg->u.link_addr.ports[i].input_port = 1;
812 :
813 0 : repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
814 0 : repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
815 :
816 0 : idx++;
817 0 : if (idx > raw->curlen)
818 : goto fail_len;
819 0 : repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
820 0 : repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
821 0 : if (repmsg->u.link_addr.ports[i].input_port == 0)
822 0 : repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
823 0 : idx++;
824 0 : if (idx > raw->curlen)
825 : goto fail_len;
826 0 : if (repmsg->u.link_addr.ports[i].input_port == 0) {
827 0 : repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
828 0 : idx++;
829 0 : if (idx > raw->curlen)
830 : goto fail_len;
831 0 : memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
832 0 : idx += 16;
833 0 : if (idx > raw->curlen)
834 : goto fail_len;
835 0 : repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
836 0 : repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
837 0 : idx++;
838 :
839 : }
840 0 : if (idx > raw->curlen)
841 : goto fail_len;
842 : }
843 :
844 : return true;
845 : fail_len:
846 0 : DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
847 : return false;
848 : }
849 :
850 0 : static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
851 : struct drm_dp_sideband_msg_reply_body *repmsg)
852 : {
853 0 : int idx = 1;
854 :
855 0 : repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
856 0 : idx++;
857 0 : if (idx > raw->curlen)
858 : goto fail_len;
859 0 : repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
860 0 : idx++;
861 0 : if (idx > raw->curlen)
862 : goto fail_len;
863 :
864 0 : memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
865 0 : return true;
866 : fail_len:
867 0 : DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
868 0 : return false;
869 : }
870 :
871 : static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
872 : struct drm_dp_sideband_msg_reply_body *repmsg)
873 : {
874 0 : int idx = 1;
875 :
876 0 : repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
877 0 : idx++;
878 0 : if (idx > raw->curlen)
879 : goto fail_len;
880 : return true;
881 : fail_len:
882 0 : DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
883 : return false;
884 : }
885 :
886 0 : static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
887 : struct drm_dp_sideband_msg_reply_body *repmsg)
888 : {
889 0 : int idx = 1;
890 :
891 0 : repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
892 0 : idx++;
893 0 : if (idx > raw->curlen)
894 : goto fail_len;
895 0 : repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
896 0 : idx++;
897 : /* TODO check */
898 0 : memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
899 0 : return true;
900 : fail_len:
901 0 : DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
902 0 : return false;
903 : }
904 :
905 0 : static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
906 : struct drm_dp_sideband_msg_reply_body *repmsg)
907 : {
908 0 : int idx = 1;
909 :
910 0 : repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
911 0 : repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1;
912 0 : idx++;
913 0 : if (idx > raw->curlen)
914 : goto fail_len;
915 0 : repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
916 0 : idx += 2;
917 0 : if (idx > raw->curlen)
918 : goto fail_len;
919 0 : repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
920 0 : idx += 2;
921 0 : if (idx > raw->curlen)
922 : goto fail_len;
923 : return true;
924 : fail_len:
925 0 : DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
926 0 : return false;
927 : }
928 :
929 0 : static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
930 : struct drm_dp_sideband_msg_reply_body *repmsg)
931 : {
932 0 : int idx = 1;
933 :
934 0 : repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
935 0 : idx++;
936 0 : if (idx > raw->curlen)
937 : goto fail_len;
938 0 : repmsg->u.allocate_payload.vcpi = raw->msg[idx];
939 0 : idx++;
940 0 : if (idx > raw->curlen)
941 : goto fail_len;
942 0 : repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
943 0 : idx += 2;
944 0 : if (idx > raw->curlen)
945 : goto fail_len;
946 : return true;
947 : fail_len:
948 0 : DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
949 0 : return false;
950 : }
951 :
952 0 : static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
953 : struct drm_dp_sideband_msg_reply_body *repmsg)
954 : {
955 0 : int idx = 1;
956 :
957 0 : repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
958 0 : idx++;
959 0 : if (idx > raw->curlen)
960 : goto fail_len;
961 0 : repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
962 0 : idx += 2;
963 0 : if (idx > raw->curlen)
964 : goto fail_len;
965 : return true;
966 : fail_len:
967 0 : DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
968 : return false;
969 : }
970 :
971 : static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
972 : struct drm_dp_sideband_msg_reply_body *repmsg)
973 : {
974 0 : int idx = 1;
975 :
976 0 : repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
977 0 : idx++;
978 0 : if (idx > raw->curlen) {
979 0 : DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
980 : idx, raw->curlen);
981 : return false;
982 : }
983 : return true;
984 : }
985 :
986 : static bool
987 0 : drm_dp_sideband_parse_query_stream_enc_status(
988 : struct drm_dp_sideband_msg_rx *raw,
989 : struct drm_dp_sideband_msg_reply_body *repmsg)
990 : {
991 : struct drm_dp_query_stream_enc_status_ack_reply *reply;
992 :
993 0 : reply = &repmsg->u.enc_status;
994 :
995 0 : reply->stream_id = raw->msg[3];
996 :
997 0 : reply->reply_signed = raw->msg[2] & BIT(0);
998 :
999 : /*
1000 : * NOTE: It's my impression from reading the spec that the below parsing
1001 : * is correct. However I noticed while testing with an HDCP 1.4 display
1002 : * through an HDCP 2.2 hub that only bit 3 was set. In that case, I
1003 : * would expect both bits to be set. So keep the parsing following the
1004 : * spec, but beware reality might not match the spec (at least for some
1005 : * configurations).
1006 : */
1007 0 : reply->hdcp_1x_device_present = raw->msg[2] & BIT(4);
1008 0 : reply->hdcp_2x_device_present = raw->msg[2] & BIT(3);
1009 :
1010 0 : reply->query_capable_device_present = raw->msg[2] & BIT(5);
1011 0 : reply->legacy_device_present = raw->msg[2] & BIT(6);
1012 0 : reply->unauthorizable_device_present = raw->msg[2] & BIT(7);
1013 :
1014 0 : reply->auth_completed = !!(raw->msg[1] & BIT(3));
1015 0 : reply->encryption_enabled = !!(raw->msg[1] & BIT(4));
1016 0 : reply->repeater_present = !!(raw->msg[1] & BIT(5));
1017 0 : reply->state = (raw->msg[1] & GENMASK(7, 6)) >> 6;
1018 :
1019 0 : return true;
1020 : }
1021 :
1022 0 : static bool drm_dp_sideband_parse_reply(const struct drm_dp_mst_topology_mgr *mgr,
1023 : struct drm_dp_sideband_msg_rx *raw,
1024 : struct drm_dp_sideband_msg_reply_body *msg)
1025 : {
1026 0 : memset(msg, 0, sizeof(*msg));
1027 0 : msg->reply_type = (raw->msg[0] & 0x80) >> 7;
1028 0 : msg->req_type = (raw->msg[0] & 0x7f);
1029 :
1030 0 : if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
1031 0 : memcpy(msg->u.nak.guid, &raw->msg[1], 16);
1032 0 : msg->u.nak.reason = raw->msg[17];
1033 0 : msg->u.nak.nak_data = raw->msg[18];
1034 : return false;
1035 : }
1036 :
1037 0 : switch (msg->req_type) {
1038 : case DP_LINK_ADDRESS:
1039 0 : return drm_dp_sideband_parse_link_address(mgr, raw, msg);
1040 : case DP_QUERY_PAYLOAD:
1041 0 : return drm_dp_sideband_parse_query_payload_ack(raw, msg);
1042 : case DP_REMOTE_DPCD_READ:
1043 0 : return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
1044 : case DP_REMOTE_DPCD_WRITE:
1045 0 : return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
1046 : case DP_REMOTE_I2C_READ:
1047 0 : return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
1048 : case DP_REMOTE_I2C_WRITE:
1049 : return true; /* since there's nothing to parse */
1050 : case DP_ENUM_PATH_RESOURCES:
1051 0 : return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
1052 : case DP_ALLOCATE_PAYLOAD:
1053 0 : return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
1054 : case DP_POWER_DOWN_PHY:
1055 : case DP_POWER_UP_PHY:
1056 0 : return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
1057 : case DP_CLEAR_PAYLOAD_ID_TABLE:
1058 : return true; /* since there's nothing to parse */
1059 : case DP_QUERY_STREAM_ENC_STATUS:
1060 0 : return drm_dp_sideband_parse_query_stream_enc_status(raw, msg);
1061 : default:
1062 0 : drm_err(mgr->dev, "Got unknown reply 0x%02x (%s)\n",
1063 : msg->req_type, drm_dp_mst_req_type_str(msg->req_type));
1064 : return false;
1065 : }
1066 : }
1067 :
1068 : static bool
1069 0 : drm_dp_sideband_parse_connection_status_notify(const struct drm_dp_mst_topology_mgr *mgr,
1070 : struct drm_dp_sideband_msg_rx *raw,
1071 : struct drm_dp_sideband_msg_req_body *msg)
1072 : {
1073 0 : int idx = 1;
1074 :
1075 0 : msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
1076 0 : idx++;
1077 0 : if (idx > raw->curlen)
1078 : goto fail_len;
1079 :
1080 0 : memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
1081 0 : idx += 16;
1082 0 : if (idx > raw->curlen)
1083 : goto fail_len;
1084 :
1085 0 : msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
1086 0 : msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
1087 0 : msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
1088 0 : msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
1089 0 : msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
1090 0 : idx++;
1091 : return true;
1092 : fail_len:
1093 0 : drm_dbg_kms(mgr->dev, "connection status reply parse length fail %d %d\n",
1094 : idx, raw->curlen);
1095 : return false;
1096 : }
1097 :
1098 0 : static bool drm_dp_sideband_parse_resource_status_notify(const struct drm_dp_mst_topology_mgr *mgr,
1099 : struct drm_dp_sideband_msg_rx *raw,
1100 : struct drm_dp_sideband_msg_req_body *msg)
1101 : {
1102 0 : int idx = 1;
1103 :
1104 0 : msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
1105 0 : idx++;
1106 0 : if (idx > raw->curlen)
1107 : goto fail_len;
1108 :
1109 0 : memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
1110 0 : idx += 16;
1111 0 : if (idx > raw->curlen)
1112 : goto fail_len;
1113 :
1114 0 : msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
1115 0 : idx++;
1116 : return true;
1117 : fail_len:
1118 0 : drm_dbg_kms(mgr->dev, "resource status reply parse length fail %d %d\n", idx, raw->curlen);
1119 : return false;
1120 : }
1121 :
1122 0 : static bool drm_dp_sideband_parse_req(const struct drm_dp_mst_topology_mgr *mgr,
1123 : struct drm_dp_sideband_msg_rx *raw,
1124 : struct drm_dp_sideband_msg_req_body *msg)
1125 : {
1126 0 : memset(msg, 0, sizeof(*msg));
1127 0 : msg->req_type = (raw->msg[0] & 0x7f);
1128 :
1129 0 : switch (msg->req_type) {
1130 : case DP_CONNECTION_STATUS_NOTIFY:
1131 0 : return drm_dp_sideband_parse_connection_status_notify(mgr, raw, msg);
1132 : case DP_RESOURCE_STATUS_NOTIFY:
1133 0 : return drm_dp_sideband_parse_resource_status_notify(mgr, raw, msg);
1134 : default:
1135 0 : drm_err(mgr->dev, "Got unknown request 0x%02x (%s)\n",
1136 : msg->req_type, drm_dp_mst_req_type_str(msg->req_type));
1137 0 : return false;
1138 : }
1139 : }
1140 :
1141 0 : static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg,
1142 : u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
1143 : {
1144 : struct drm_dp_sideband_msg_req_body req;
1145 :
1146 0 : req.req_type = DP_REMOTE_DPCD_WRITE;
1147 0 : req.u.dpcd_write.port_number = port_num;
1148 0 : req.u.dpcd_write.dpcd_address = offset;
1149 0 : req.u.dpcd_write.num_bytes = num_bytes;
1150 0 : req.u.dpcd_write.bytes = bytes;
1151 0 : drm_dp_encode_sideband_req(&req, msg);
1152 0 : }
1153 :
1154 0 : static void build_link_address(struct drm_dp_sideband_msg_tx *msg)
1155 : {
1156 : struct drm_dp_sideband_msg_req_body req;
1157 :
1158 0 : req.req_type = DP_LINK_ADDRESS;
1159 0 : drm_dp_encode_sideband_req(&req, msg);
1160 0 : }
1161 :
1162 0 : static void build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
1163 : {
1164 : struct drm_dp_sideband_msg_req_body req;
1165 :
1166 0 : req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE;
1167 0 : drm_dp_encode_sideband_req(&req, msg);
1168 0 : msg->path_msg = true;
1169 0 : }
1170 :
1171 0 : static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg,
1172 : int port_num)
1173 : {
1174 : struct drm_dp_sideband_msg_req_body req;
1175 :
1176 0 : req.req_type = DP_ENUM_PATH_RESOURCES;
1177 0 : req.u.port_num.port_number = port_num;
1178 0 : drm_dp_encode_sideband_req(&req, msg);
1179 0 : msg->path_msg = true;
1180 0 : return 0;
1181 : }
1182 :
1183 0 : static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg,
1184 : int port_num,
1185 : u8 vcpi, uint16_t pbn,
1186 : u8 number_sdp_streams,
1187 : u8 *sdp_stream_sink)
1188 : {
1189 : struct drm_dp_sideband_msg_req_body req;
1190 :
1191 0 : memset(&req, 0, sizeof(req));
1192 0 : req.req_type = DP_ALLOCATE_PAYLOAD;
1193 0 : req.u.allocate_payload.port_number = port_num;
1194 0 : req.u.allocate_payload.vcpi = vcpi;
1195 0 : req.u.allocate_payload.pbn = pbn;
1196 0 : req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
1197 0 : memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
1198 : number_sdp_streams);
1199 0 : drm_dp_encode_sideband_req(&req, msg);
1200 0 : msg->path_msg = true;
1201 0 : }
1202 :
1203 0 : static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
1204 : int port_num, bool power_up)
1205 : {
1206 : struct drm_dp_sideband_msg_req_body req;
1207 :
1208 0 : if (power_up)
1209 0 : req.req_type = DP_POWER_UP_PHY;
1210 : else
1211 0 : req.req_type = DP_POWER_DOWN_PHY;
1212 :
1213 0 : req.u.port_num.port_number = port_num;
1214 0 : drm_dp_encode_sideband_req(&req, msg);
1215 0 : msg->path_msg = true;
1216 0 : }
1217 :
1218 : static int
1219 0 : build_query_stream_enc_status(struct drm_dp_sideband_msg_tx *msg, u8 stream_id,
1220 : u8 *q_id)
1221 : {
1222 : struct drm_dp_sideband_msg_req_body req;
1223 :
1224 0 : req.req_type = DP_QUERY_STREAM_ENC_STATUS;
1225 0 : req.u.enc_status.stream_id = stream_id;
1226 0 : memcpy(req.u.enc_status.client_id, q_id,
1227 : sizeof(req.u.enc_status.client_id));
1228 0 : req.u.enc_status.stream_event = 0;
1229 0 : req.u.enc_status.valid_stream_event = false;
1230 0 : req.u.enc_status.stream_behavior = 0;
1231 0 : req.u.enc_status.valid_stream_behavior = false;
1232 :
1233 0 : drm_dp_encode_sideband_req(&req, msg);
1234 0 : return 0;
1235 : }
1236 :
1237 : static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
1238 : struct drm_dp_sideband_msg_tx *txmsg)
1239 : {
1240 : unsigned int state;
1241 :
1242 : /*
1243 : * All updates to txmsg->state are protected by mgr->qlock, and the two
1244 : * cases we check here are terminal states. For those the barriers
1245 : * provided by the wake_up/wait_event pair are enough.
1246 : */
1247 0 : state = READ_ONCE(txmsg->state);
1248 0 : return (state == DRM_DP_SIDEBAND_TX_RX ||
1249 : state == DRM_DP_SIDEBAND_TX_TIMEOUT);
1250 : }
1251 :
1252 0 : static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
1253 : struct drm_dp_sideband_msg_tx *txmsg)
1254 : {
1255 0 : struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1256 0 : unsigned long wait_timeout = msecs_to_jiffies(4000);
1257 0 : unsigned long wait_expires = jiffies + wait_timeout;
1258 : int ret;
1259 :
1260 : for (;;) {
1261 : /*
1262 : * If the driver provides a way for this, change to
1263 : * poll-waiting for the MST reply interrupt if we didn't receive
1264 : * it for 50 msec. This would cater for cases where the HPD
1265 : * pulse signal got lost somewhere, even though the sink raised
1266 : * the corresponding MST interrupt correctly. One example is the
1267 : * Club 3D CAC-1557 TypeC -> DP adapter which for some reason
1268 : * filters out short pulses with a duration less than ~540 usec.
1269 : *
1270 : * The poll period is 50 msec to avoid missing an interrupt
1271 : * after the sink has cleared it (after a 110msec timeout
1272 : * since it raised the interrupt).
1273 : */
1274 0 : ret = wait_event_timeout(mgr->tx_waitq,
1275 : check_txmsg_state(mgr, txmsg),
1276 : mgr->cbs->poll_hpd_irq ?
1277 : msecs_to_jiffies(50) :
1278 : wait_timeout);
1279 :
1280 0 : if (ret || !mgr->cbs->poll_hpd_irq ||
1281 0 : time_after(jiffies, wait_expires))
1282 : break;
1283 :
1284 0 : mgr->cbs->poll_hpd_irq(mgr);
1285 : }
1286 :
1287 0 : mutex_lock(&mgr->qlock);
1288 0 : if (ret > 0) {
1289 0 : if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
1290 0 : ret = -EIO;
1291 : goto out;
1292 : }
1293 : } else {
1294 0 : drm_dbg_kms(mgr->dev, "timedout msg send %p %d %d\n",
1295 : txmsg, txmsg->state, txmsg->seqno);
1296 :
1297 : /* dump some state */
1298 0 : ret = -EIO;
1299 :
1300 : /* remove from q */
1301 0 : if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
1302 0 : txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
1303 : txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
1304 0 : list_del(&txmsg->next);
1305 : }
1306 : out:
1307 0 : if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
1308 0 : struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1309 :
1310 0 : drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
1311 : }
1312 0 : mutex_unlock(&mgr->qlock);
1313 :
1314 0 : drm_dp_mst_kick_tx(mgr);
1315 0 : return ret;
1316 : }
1317 :
1318 0 : static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
1319 : {
1320 : struct drm_dp_mst_branch *mstb;
1321 :
1322 0 : mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
1323 0 : if (!mstb)
1324 : return NULL;
1325 :
1326 0 : mstb->lct = lct;
1327 0 : if (lct > 1)
1328 0 : memcpy(mstb->rad, rad, lct / 2);
1329 0 : INIT_LIST_HEAD(&mstb->ports);
1330 0 : kref_init(&mstb->topology_kref);
1331 0 : kref_init(&mstb->malloc_kref);
1332 0 : return mstb;
1333 : }
1334 :
1335 0 : static void drm_dp_free_mst_branch_device(struct kref *kref)
1336 : {
1337 0 : struct drm_dp_mst_branch *mstb =
1338 0 : container_of(kref, struct drm_dp_mst_branch, malloc_kref);
1339 :
1340 0 : if (mstb->port_parent)
1341 0 : drm_dp_mst_put_port_malloc(mstb->port_parent);
1342 :
1343 0 : kfree(mstb);
1344 0 : }
1345 :
1346 : /**
1347 : * DOC: Branch device and port refcounting
1348 : *
1349 : * Topology refcount overview
1350 : * ~~~~~~~~~~~~~~~~~~~~~~~~~~
1351 : *
1352 : * The refcounting schemes for &struct drm_dp_mst_branch and &struct
1353 : * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
1354 : * two different kinds of refcounts: topology refcounts, and malloc refcounts.
1355 : *
1356 : * Topology refcounts are not exposed to drivers, and are handled internally
1357 : * by the DP MST helpers. The helpers use them in order to prevent the
1358 : * in-memory topology state from being changed in the middle of critical
1359 : * operations like changing the internal state of payload allocations. This
1360 : * means each branch and port will be considered to be connected to the rest
1361 : * of the topology until its topology refcount reaches zero. Additionally,
1362 : * for ports this means that their associated &struct drm_connector will stay
1363 : * registered with userspace until the port's refcount reaches 0.
1364 : *
1365 : * Malloc refcount overview
1366 : * ~~~~~~~~~~~~~~~~~~~~~~~~
1367 : *
1368 : * Malloc references are used to keep a &struct drm_dp_mst_port or &struct
1369 : * drm_dp_mst_branch allocated even after all of its topology references have
1370 : * been dropped, so that the driver or MST helpers can safely access each
1371 : * branch's last known state before it was disconnected from the topology.
1372 : * When the malloc refcount of a port or branch reaches 0, the memory
1373 : * allocation containing the &struct drm_dp_mst_branch or &struct
1374 : * drm_dp_mst_port respectively will be freed.
1375 : *
1376 : * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
1377 : * to drivers. As of writing this documentation, there are no drivers that
1378 : * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
1379 : * helpers. Exposing this API to drivers in a race-free manner would take more
1380 : * tweaking of the refcounting scheme, however patches are welcome provided
1381 : * there is a legitimate driver usecase for this.
1382 : *
1383 : * Refcount relationships in a topology
1384 : * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1385 : *
1386 : * Let's take a look at why the relationship between topology and malloc
1387 : * refcounts is designed the way it is.
1388 : *
1389 : * .. kernel-figure:: dp-mst/topology-figure-1.dot
1390 : *
1391 : * An example of topology and malloc refs in a DP MST topology with two
1392 : * active payloads. Topology refcount increments are indicated by solid
1393 : * lines, and malloc refcount increments are indicated by dashed lines.
1394 : * Each starts from the branch which incremented the refcount, and ends at
1395 : * the branch to which the refcount belongs to, i.e. the arrow points the
1396 : * same way as the C pointers used to reference a structure.
1397 : *
1398 : * As you can see in the above figure, every branch increments the topology
1399 : * refcount of its children, and increments the malloc refcount of its
1400 : * parent. Additionally, every payload increments the malloc refcount of its
1401 : * assigned port by 1.
1402 : *
1403 : * So, what would happen if MSTB #3 from the above figure was unplugged from
1404 : * the system, but the driver hadn't yet removed payload #2 from port #3? The
1405 : * topology would start to look like the figure below.
1406 : *
1407 : * .. kernel-figure:: dp-mst/topology-figure-2.dot
1408 : *
1409 : * Ports and branch devices which have been released from memory are
1410 : * colored grey, and references which have been removed are colored red.
1411 : *
1412 : * Whenever a port or branch device's topology refcount reaches zero, it will
1413 : * decrement the topology refcounts of all its children, the malloc refcount
1414 : * of its parent, and finally its own malloc refcount. For MSTB #4 and port
1415 : * #4, this means they both have been disconnected from the topology and freed
1416 : * from memory. But, because payload #2 is still holding a reference to port
1417 : * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
1418 : * is still accessible from memory. This also means port #3 has not yet
1419 : * decremented the malloc refcount of MSTB #3, so its &struct
1420 : * drm_dp_mst_branch will also stay allocated in memory until port #3's
1421 : * malloc refcount reaches 0.
1422 : *
1423 : * This relationship is necessary because in order to release payload #2, we
1424 : * need to be able to figure out the last relative of port #3 that's still
1425 : * connected to the topology. In this case, we would travel up the topology as
1426 : * shown below.
1427 : *
1428 : * .. kernel-figure:: dp-mst/topology-figure-3.dot
1429 : *
1430 : * And finally, remove payload #2 by communicating with port #2 through
1431 : * sideband transactions.
1432 : */
1433 :
1434 : /**
1435 : * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
1436 : * device
1437 : * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
1438 : *
1439 : * Increments &drm_dp_mst_branch.malloc_kref. When
1440 : * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1441 : * will be released and @mstb may no longer be used.
1442 : *
1443 : * See also: drm_dp_mst_put_mstb_malloc()
1444 : */
1445 : static void
1446 0 : drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
1447 : {
1448 0 : kref_get(&mstb->malloc_kref);
1449 0 : drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
1450 0 : }
1451 :
1452 : /**
1453 : * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
1454 : * device
1455 : * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
1456 : *
1457 : * Decrements &drm_dp_mst_branch.malloc_kref. When
1458 : * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1459 : * will be released and @mstb may no longer be used.
1460 : *
1461 : * See also: drm_dp_mst_get_mstb_malloc()
1462 : */
1463 : static void
1464 0 : drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
1465 : {
1466 0 : drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
1467 0 : kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
1468 0 : }
1469 :
1470 0 : static void drm_dp_free_mst_port(struct kref *kref)
1471 : {
1472 0 : struct drm_dp_mst_port *port =
1473 0 : container_of(kref, struct drm_dp_mst_port, malloc_kref);
1474 :
1475 0 : drm_dp_mst_put_mstb_malloc(port->parent);
1476 0 : kfree(port);
1477 0 : }
1478 :
1479 : /**
1480 : * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
1481 : * @port: The &struct drm_dp_mst_port to increment the malloc refcount of
1482 : *
1483 : * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1484 : * reaches 0, the memory allocation for @port will be released and @port may
1485 : * no longer be used.
1486 : *
1487 : * Because @port could potentially be freed at any time by the DP MST helpers
1488 : * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
1489 : * function, drivers that which to make use of &struct drm_dp_mst_port should
1490 : * ensure that they grab at least one main malloc reference to their MST ports
1491 : * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
1492 : * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
1493 : *
1494 : * See also: drm_dp_mst_put_port_malloc()
1495 : */
1496 : void
1497 0 : drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
1498 : {
1499 0 : kref_get(&port->malloc_kref);
1500 0 : drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref));
1501 0 : }
1502 : EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
1503 :
1504 : /**
1505 : * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
1506 : * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
1507 : *
1508 : * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1509 : * reaches 0, the memory allocation for @port will be released and @port may
1510 : * no longer be used.
1511 : *
1512 : * See also: drm_dp_mst_get_port_malloc()
1513 : */
1514 : void
1515 0 : drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
1516 : {
1517 0 : drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
1518 0 : kref_put(&port->malloc_kref, drm_dp_free_mst_port);
1519 0 : }
1520 : EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
1521 :
1522 : #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
1523 :
1524 : #define STACK_DEPTH 8
1525 :
1526 : static noinline void
1527 : __topology_ref_save(struct drm_dp_mst_topology_mgr *mgr,
1528 : struct drm_dp_mst_topology_ref_history *history,
1529 : enum drm_dp_mst_topology_ref_type type)
1530 : {
1531 : struct drm_dp_mst_topology_ref_entry *entry = NULL;
1532 : depot_stack_handle_t backtrace;
1533 : ulong stack_entries[STACK_DEPTH];
1534 : uint n;
1535 : int i;
1536 :
1537 : n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1);
1538 : backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL);
1539 : if (!backtrace)
1540 : return;
1541 :
1542 : /* Try to find an existing entry for this backtrace */
1543 : for (i = 0; i < history->len; i++) {
1544 : if (history->entries[i].backtrace == backtrace) {
1545 : entry = &history->entries[i];
1546 : break;
1547 : }
1548 : }
1549 :
1550 : /* Otherwise add one */
1551 : if (!entry) {
1552 : struct drm_dp_mst_topology_ref_entry *new;
1553 : int new_len = history->len + 1;
1554 :
1555 : new = krealloc(history->entries, sizeof(*new) * new_len,
1556 : GFP_KERNEL);
1557 : if (!new)
1558 : return;
1559 :
1560 : entry = &new[history->len];
1561 : history->len = new_len;
1562 : history->entries = new;
1563 :
1564 : entry->backtrace = backtrace;
1565 : entry->type = type;
1566 : entry->count = 0;
1567 : }
1568 : entry->count++;
1569 : entry->ts_nsec = ktime_get_ns();
1570 : }
1571 :
1572 : static int
1573 : topology_ref_history_cmp(const void *a, const void *b)
1574 : {
1575 : const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b;
1576 :
1577 : if (entry_a->ts_nsec > entry_b->ts_nsec)
1578 : return 1;
1579 : else if (entry_a->ts_nsec < entry_b->ts_nsec)
1580 : return -1;
1581 : else
1582 : return 0;
1583 : }
1584 :
1585 : static inline const char *
1586 : topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type)
1587 : {
1588 : if (type == DRM_DP_MST_TOPOLOGY_REF_GET)
1589 : return "get";
1590 : else
1591 : return "put";
1592 : }
1593 :
1594 : static void
1595 : __dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history,
1596 : void *ptr, const char *type_str)
1597 : {
1598 : struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1599 : char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1600 : int i;
1601 :
1602 : if (!buf)
1603 : return;
1604 :
1605 : if (!history->len)
1606 : goto out;
1607 :
1608 : /* First, sort the list so that it goes from oldest to newest
1609 : * reference entry
1610 : */
1611 : sort(history->entries, history->len, sizeof(*history->entries),
1612 : topology_ref_history_cmp, NULL);
1613 :
1614 : drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n",
1615 : type_str, ptr);
1616 :
1617 : for (i = 0; i < history->len; i++) {
1618 : const struct drm_dp_mst_topology_ref_entry *entry =
1619 : &history->entries[i];
1620 : u64 ts_nsec = entry->ts_nsec;
1621 : u32 rem_nsec = do_div(ts_nsec, 1000000000);
1622 :
1623 : stack_depot_snprint(entry->backtrace, buf, PAGE_SIZE, 4);
1624 :
1625 : drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s",
1626 : entry->count,
1627 : topology_ref_type_to_str(entry->type),
1628 : ts_nsec, rem_nsec / 1000, buf);
1629 : }
1630 :
1631 : /* Now free the history, since this is the only time we expose it */
1632 : kfree(history->entries);
1633 : out:
1634 : kfree(buf);
1635 : }
1636 :
1637 : static __always_inline void
1638 : drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb)
1639 : {
1640 : __dump_topology_ref_history(&mstb->topology_ref_history, mstb,
1641 : "MSTB");
1642 : }
1643 :
1644 : static __always_inline void
1645 : drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port)
1646 : {
1647 : __dump_topology_ref_history(&port->topology_ref_history, port,
1648 : "Port");
1649 : }
1650 :
1651 : static __always_inline void
1652 : save_mstb_topology_ref(struct drm_dp_mst_branch *mstb,
1653 : enum drm_dp_mst_topology_ref_type type)
1654 : {
1655 : __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type);
1656 : }
1657 :
1658 : static __always_inline void
1659 : save_port_topology_ref(struct drm_dp_mst_port *port,
1660 : enum drm_dp_mst_topology_ref_type type)
1661 : {
1662 : __topology_ref_save(port->mgr, &port->topology_ref_history, type);
1663 : }
1664 :
1665 : static inline void
1666 : topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr)
1667 : {
1668 : mutex_lock(&mgr->topology_ref_history_lock);
1669 : }
1670 :
1671 : static inline void
1672 : topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr)
1673 : {
1674 : mutex_unlock(&mgr->topology_ref_history_lock);
1675 : }
1676 : #else
1677 : static inline void
1678 : topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {}
1679 : static inline void
1680 : topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {}
1681 : static inline void
1682 : drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {}
1683 : static inline void
1684 : drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {}
1685 : #define save_mstb_topology_ref(mstb, type)
1686 : #define save_port_topology_ref(port, type)
1687 : #endif
1688 :
1689 : struct drm_dp_mst_atomic_payload *
1690 0 : drm_atomic_get_mst_payload_state(struct drm_dp_mst_topology_state *state,
1691 : struct drm_dp_mst_port *port)
1692 : {
1693 : struct drm_dp_mst_atomic_payload *payload;
1694 :
1695 0 : list_for_each_entry(payload, &state->payloads, next)
1696 0 : if (payload->port == port)
1697 : return payload;
1698 :
1699 : return NULL;
1700 : }
1701 : EXPORT_SYMBOL(drm_atomic_get_mst_payload_state);
1702 :
1703 0 : static void drm_dp_destroy_mst_branch_device(struct kref *kref)
1704 : {
1705 0 : struct drm_dp_mst_branch *mstb =
1706 0 : container_of(kref, struct drm_dp_mst_branch, topology_kref);
1707 0 : struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1708 :
1709 0 : drm_dp_mst_dump_mstb_topology_history(mstb);
1710 :
1711 0 : INIT_LIST_HEAD(&mstb->destroy_next);
1712 :
1713 : /*
1714 : * This can get called under mgr->mutex, so we need to perform the
1715 : * actual destruction of the mstb in another worker
1716 : */
1717 0 : mutex_lock(&mgr->delayed_destroy_lock);
1718 0 : list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list);
1719 0 : mutex_unlock(&mgr->delayed_destroy_lock);
1720 0 : queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1721 0 : }
1722 :
1723 : /**
1724 : * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1725 : * branch device unless it's zero
1726 : * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
1727 : *
1728 : * Attempts to grab a topology reference to @mstb, if it hasn't yet been
1729 : * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
1730 : * reached 0). Holding a topology reference implies that a malloc reference
1731 : * will be held to @mstb as long as the user holds the topology reference.
1732 : *
1733 : * Care should be taken to ensure that the user has at least one malloc
1734 : * reference to @mstb. If you already have a topology reference to @mstb, you
1735 : * should use drm_dp_mst_topology_get_mstb() instead.
1736 : *
1737 : * See also:
1738 : * drm_dp_mst_topology_get_mstb()
1739 : * drm_dp_mst_topology_put_mstb()
1740 : *
1741 : * Returns:
1742 : * * 1: A topology reference was grabbed successfully
1743 : * * 0: @port is no longer in the topology, no reference was grabbed
1744 : */
1745 : static int __must_check
1746 0 : drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
1747 : {
1748 : int ret;
1749 :
1750 0 : topology_ref_history_lock(mstb->mgr);
1751 0 : ret = kref_get_unless_zero(&mstb->topology_kref);
1752 0 : if (ret) {
1753 0 : drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1754 : save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1755 : }
1756 :
1757 0 : topology_ref_history_unlock(mstb->mgr);
1758 :
1759 0 : return ret;
1760 : }
1761 :
1762 : /**
1763 : * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
1764 : * branch device
1765 : * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
1766 : *
1767 : * Increments &drm_dp_mst_branch.topology_refcount without checking whether or
1768 : * not it's already reached 0. This is only valid to use in scenarios where
1769 : * you are already guaranteed to have at least one active topology reference
1770 : * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
1771 : *
1772 : * See also:
1773 : * drm_dp_mst_topology_try_get_mstb()
1774 : * drm_dp_mst_topology_put_mstb()
1775 : */
1776 0 : static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
1777 : {
1778 0 : topology_ref_history_lock(mstb->mgr);
1779 :
1780 : save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1781 0 : WARN_ON(kref_read(&mstb->topology_kref) == 0);
1782 0 : kref_get(&mstb->topology_kref);
1783 0 : drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1784 :
1785 0 : topology_ref_history_unlock(mstb->mgr);
1786 0 : }
1787 :
1788 : /**
1789 : * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
1790 : * device
1791 : * @mstb: The &struct drm_dp_mst_branch to release the topology reference from
1792 : *
1793 : * Releases a topology reference from @mstb by decrementing
1794 : * &drm_dp_mst_branch.topology_kref.
1795 : *
1796 : * See also:
1797 : * drm_dp_mst_topology_try_get_mstb()
1798 : * drm_dp_mst_topology_get_mstb()
1799 : */
1800 : static void
1801 0 : drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
1802 : {
1803 0 : topology_ref_history_lock(mstb->mgr);
1804 :
1805 0 : drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref) - 1);
1806 : save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT);
1807 :
1808 0 : topology_ref_history_unlock(mstb->mgr);
1809 0 : kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
1810 0 : }
1811 :
1812 0 : static void drm_dp_destroy_port(struct kref *kref)
1813 : {
1814 0 : struct drm_dp_mst_port *port =
1815 0 : container_of(kref, struct drm_dp_mst_port, topology_kref);
1816 0 : struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1817 :
1818 0 : drm_dp_mst_dump_port_topology_history(port);
1819 :
1820 : /* There's nothing that needs locking to destroy an input port yet */
1821 0 : if (port->input) {
1822 0 : drm_dp_mst_put_port_malloc(port);
1823 0 : return;
1824 : }
1825 :
1826 0 : drm_edid_free(port->cached_edid);
1827 :
1828 : /*
1829 : * we can't destroy the connector here, as we might be holding the
1830 : * mode_config.mutex from an EDID retrieval
1831 : */
1832 0 : mutex_lock(&mgr->delayed_destroy_lock);
1833 0 : list_add(&port->next, &mgr->destroy_port_list);
1834 0 : mutex_unlock(&mgr->delayed_destroy_lock);
1835 0 : queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1836 : }
1837 :
1838 : /**
1839 : * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
1840 : * port unless it's zero
1841 : * @port: &struct drm_dp_mst_port to increment the topology refcount of
1842 : *
1843 : * Attempts to grab a topology reference to @port, if it hasn't yet been
1844 : * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
1845 : * 0). Holding a topology reference implies that a malloc reference will be
1846 : * held to @port as long as the user holds the topology reference.
1847 : *
1848 : * Care should be taken to ensure that the user has at least one malloc
1849 : * reference to @port. If you already have a topology reference to @port, you
1850 : * should use drm_dp_mst_topology_get_port() instead.
1851 : *
1852 : * See also:
1853 : * drm_dp_mst_topology_get_port()
1854 : * drm_dp_mst_topology_put_port()
1855 : *
1856 : * Returns:
1857 : * * 1: A topology reference was grabbed successfully
1858 : * * 0: @port is no longer in the topology, no reference was grabbed
1859 : */
1860 : static int __must_check
1861 0 : drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
1862 : {
1863 : int ret;
1864 :
1865 0 : topology_ref_history_lock(port->mgr);
1866 0 : ret = kref_get_unless_zero(&port->topology_kref);
1867 0 : if (ret) {
1868 0 : drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref));
1869 : save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1870 : }
1871 :
1872 0 : topology_ref_history_unlock(port->mgr);
1873 0 : return ret;
1874 : }
1875 :
1876 : /**
1877 : * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
1878 : * @port: The &struct drm_dp_mst_port to increment the topology refcount of
1879 : *
1880 : * Increments &drm_dp_mst_port.topology_refcount without checking whether or
1881 : * not it's already reached 0. This is only valid to use in scenarios where
1882 : * you are already guaranteed to have at least one active topology reference
1883 : * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
1884 : *
1885 : * See also:
1886 : * drm_dp_mst_topology_try_get_port()
1887 : * drm_dp_mst_topology_put_port()
1888 : */
1889 0 : static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
1890 : {
1891 0 : topology_ref_history_lock(port->mgr);
1892 :
1893 0 : WARN_ON(kref_read(&port->topology_kref) == 0);
1894 0 : kref_get(&port->topology_kref);
1895 0 : drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref));
1896 : save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1897 :
1898 0 : topology_ref_history_unlock(port->mgr);
1899 0 : }
1900 :
1901 : /**
1902 : * drm_dp_mst_topology_put_port() - release a topology reference to a port
1903 : * @port: The &struct drm_dp_mst_port to release the topology reference from
1904 : *
1905 : * Releases a topology reference from @port by decrementing
1906 : * &drm_dp_mst_port.topology_kref.
1907 : *
1908 : * See also:
1909 : * drm_dp_mst_topology_try_get_port()
1910 : * drm_dp_mst_topology_get_port()
1911 : */
1912 0 : static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
1913 : {
1914 0 : topology_ref_history_lock(port->mgr);
1915 :
1916 0 : drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref) - 1);
1917 : save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT);
1918 :
1919 0 : topology_ref_history_unlock(port->mgr);
1920 0 : kref_put(&port->topology_kref, drm_dp_destroy_port);
1921 0 : }
1922 :
1923 : static struct drm_dp_mst_branch *
1924 0 : drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
1925 : struct drm_dp_mst_branch *to_find)
1926 : {
1927 : struct drm_dp_mst_port *port;
1928 : struct drm_dp_mst_branch *rmstb;
1929 :
1930 0 : if (to_find == mstb)
1931 : return mstb;
1932 :
1933 0 : list_for_each_entry(port, &mstb->ports, next) {
1934 0 : if (port->mstb) {
1935 0 : rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1936 : port->mstb, to_find);
1937 0 : if (rmstb)
1938 : return rmstb;
1939 : }
1940 : }
1941 : return NULL;
1942 : }
1943 :
1944 : static struct drm_dp_mst_branch *
1945 0 : drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
1946 : struct drm_dp_mst_branch *mstb)
1947 : {
1948 0 : struct drm_dp_mst_branch *rmstb = NULL;
1949 :
1950 0 : mutex_lock(&mgr->lock);
1951 0 : if (mgr->mst_primary) {
1952 0 : rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1953 : mgr->mst_primary, mstb);
1954 :
1955 0 : if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
1956 0 : rmstb = NULL;
1957 : }
1958 0 : mutex_unlock(&mgr->lock);
1959 0 : return rmstb;
1960 : }
1961 :
1962 : static struct drm_dp_mst_port *
1963 0 : drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
1964 : struct drm_dp_mst_port *to_find)
1965 : {
1966 : struct drm_dp_mst_port *port, *mport;
1967 :
1968 0 : list_for_each_entry(port, &mstb->ports, next) {
1969 0 : if (port == to_find)
1970 : return port;
1971 :
1972 0 : if (port->mstb) {
1973 0 : mport = drm_dp_mst_topology_get_port_validated_locked(
1974 : port->mstb, to_find);
1975 0 : if (mport)
1976 : return mport;
1977 : }
1978 : }
1979 : return NULL;
1980 : }
1981 :
1982 : static struct drm_dp_mst_port *
1983 0 : drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
1984 : struct drm_dp_mst_port *port)
1985 : {
1986 0 : struct drm_dp_mst_port *rport = NULL;
1987 :
1988 0 : mutex_lock(&mgr->lock);
1989 0 : if (mgr->mst_primary) {
1990 0 : rport = drm_dp_mst_topology_get_port_validated_locked(
1991 : mgr->mst_primary, port);
1992 :
1993 0 : if (rport && !drm_dp_mst_topology_try_get_port(rport))
1994 0 : rport = NULL;
1995 : }
1996 0 : mutex_unlock(&mgr->lock);
1997 0 : return rport;
1998 : }
1999 :
2000 0 : static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
2001 : {
2002 : struct drm_dp_mst_port *port;
2003 : int ret;
2004 :
2005 0 : list_for_each_entry(port, &mstb->ports, next) {
2006 0 : if (port->port_num == port_num) {
2007 0 : ret = drm_dp_mst_topology_try_get_port(port);
2008 0 : return ret ? port : NULL;
2009 : }
2010 : }
2011 :
2012 : return NULL;
2013 : }
2014 :
2015 : /*
2016 : * calculate a new RAD for this MST branch device
2017 : * if parent has an LCT of 2 then it has 1 nibble of RAD,
2018 : * if parent has an LCT of 3 then it has 2 nibbles of RAD,
2019 : */
2020 0 : static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
2021 : u8 *rad)
2022 : {
2023 0 : int parent_lct = port->parent->lct;
2024 0 : int shift = 4;
2025 0 : int idx = (parent_lct - 1) / 2;
2026 :
2027 0 : if (parent_lct > 1) {
2028 0 : memcpy(rad, port->parent->rad, idx + 1);
2029 0 : shift = (parent_lct % 2) ? 4 : 0;
2030 : } else
2031 0 : rad[0] = 0;
2032 :
2033 0 : rad[idx] |= port->port_num << shift;
2034 0 : return parent_lct + 1;
2035 : }
2036 :
2037 : static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs)
2038 : {
2039 0 : switch (pdt) {
2040 : case DP_PEER_DEVICE_DP_LEGACY_CONV:
2041 : case DP_PEER_DEVICE_SST_SINK:
2042 : return true;
2043 : case DP_PEER_DEVICE_MST_BRANCHING:
2044 : /* For sst branch device */
2045 0 : if (!mcs)
2046 : return true;
2047 :
2048 : return false;
2049 : }
2050 : return true;
2051 : }
2052 :
2053 : static int
2054 0 : drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
2055 : bool new_mcs)
2056 : {
2057 0 : struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2058 : struct drm_dp_mst_branch *mstb;
2059 : u8 rad[8], lct;
2060 0 : int ret = 0;
2061 :
2062 0 : if (port->pdt == new_pdt && port->mcs == new_mcs)
2063 : return 0;
2064 :
2065 : /* Teardown the old pdt, if there is one */
2066 0 : if (port->pdt != DP_PEER_DEVICE_NONE) {
2067 0 : if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2068 : /*
2069 : * If the new PDT would also have an i2c bus,
2070 : * don't bother with reregistering it
2071 : */
2072 0 : if (new_pdt != DP_PEER_DEVICE_NONE &&
2073 0 : drm_dp_mst_is_end_device(new_pdt, new_mcs)) {
2074 0 : port->pdt = new_pdt;
2075 0 : port->mcs = new_mcs;
2076 0 : return 0;
2077 : }
2078 :
2079 : /* remove i2c over sideband */
2080 : drm_dp_mst_unregister_i2c_bus(port);
2081 : } else {
2082 0 : mutex_lock(&mgr->lock);
2083 0 : drm_dp_mst_topology_put_mstb(port->mstb);
2084 0 : port->mstb = NULL;
2085 0 : mutex_unlock(&mgr->lock);
2086 : }
2087 : }
2088 :
2089 0 : port->pdt = new_pdt;
2090 0 : port->mcs = new_mcs;
2091 :
2092 0 : if (port->pdt != DP_PEER_DEVICE_NONE) {
2093 0 : if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2094 : /* add i2c over sideband */
2095 0 : ret = drm_dp_mst_register_i2c_bus(port);
2096 : } else {
2097 0 : lct = drm_dp_calculate_rad(port, rad);
2098 0 : mstb = drm_dp_add_mst_branch_device(lct, rad);
2099 0 : if (!mstb) {
2100 0 : ret = -ENOMEM;
2101 0 : drm_err(mgr->dev, "Failed to create MSTB for port %p", port);
2102 0 : goto out;
2103 : }
2104 :
2105 0 : mutex_lock(&mgr->lock);
2106 0 : port->mstb = mstb;
2107 0 : mstb->mgr = port->mgr;
2108 0 : mstb->port_parent = port;
2109 :
2110 : /*
2111 : * Make sure this port's memory allocation stays
2112 : * around until its child MSTB releases it
2113 : */
2114 0 : drm_dp_mst_get_port_malloc(port);
2115 0 : mutex_unlock(&mgr->lock);
2116 :
2117 : /* And make sure we send a link address for this */
2118 0 : ret = 1;
2119 : }
2120 : }
2121 :
2122 : out:
2123 0 : if (ret < 0)
2124 0 : port->pdt = DP_PEER_DEVICE_NONE;
2125 : return ret;
2126 : }
2127 :
2128 : /**
2129 : * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
2130 : * @aux: Fake sideband AUX CH
2131 : * @offset: address of the (first) register to read
2132 : * @buffer: buffer to store the register values
2133 : * @size: number of bytes in @buffer
2134 : *
2135 : * Performs the same functionality for remote devices via
2136 : * sideband messaging as drm_dp_dpcd_read() does for local
2137 : * devices via actual AUX CH.
2138 : *
2139 : * Return: Number of bytes read, or negative error code on failure.
2140 : */
2141 0 : ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
2142 : unsigned int offset, void *buffer, size_t size)
2143 : {
2144 0 : struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2145 : aux);
2146 :
2147 0 : return drm_dp_send_dpcd_read(port->mgr, port,
2148 : offset, size, buffer);
2149 : }
2150 :
2151 : /**
2152 : * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
2153 : * @aux: Fake sideband AUX CH
2154 : * @offset: address of the (first) register to write
2155 : * @buffer: buffer containing the values to write
2156 : * @size: number of bytes in @buffer
2157 : *
2158 : * Performs the same functionality for remote devices via
2159 : * sideband messaging as drm_dp_dpcd_write() does for local
2160 : * devices via actual AUX CH.
2161 : *
2162 : * Return: number of bytes written on success, negative error code on failure.
2163 : */
2164 0 : ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
2165 : unsigned int offset, void *buffer, size_t size)
2166 : {
2167 0 : struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2168 : aux);
2169 :
2170 0 : return drm_dp_send_dpcd_write(port->mgr, port,
2171 : offset, size, buffer);
2172 : }
2173 :
2174 0 : static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
2175 : {
2176 0 : int ret = 0;
2177 :
2178 0 : memcpy(mstb->guid, guid, 16);
2179 :
2180 0 : if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
2181 0 : if (mstb->port_parent) {
2182 0 : ret = drm_dp_send_dpcd_write(mstb->mgr,
2183 : mstb->port_parent,
2184 : DP_GUID, 16, mstb->guid);
2185 : } else {
2186 0 : ret = drm_dp_dpcd_write(mstb->mgr->aux,
2187 : DP_GUID, mstb->guid, 16);
2188 : }
2189 : }
2190 :
2191 0 : if (ret < 16 && ret > 0)
2192 : return -EPROTO;
2193 :
2194 0 : return ret == 16 ? 0 : ret;
2195 : }
2196 :
2197 0 : static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
2198 : int pnum,
2199 : char *proppath,
2200 : size_t proppath_size)
2201 : {
2202 : int i;
2203 : char temp[8];
2204 :
2205 0 : snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
2206 0 : for (i = 0; i < (mstb->lct - 1); i++) {
2207 0 : int shift = (i % 2) ? 0 : 4;
2208 0 : int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
2209 :
2210 0 : snprintf(temp, sizeof(temp), "-%d", port_num);
2211 0 : strlcat(proppath, temp, proppath_size);
2212 : }
2213 0 : snprintf(temp, sizeof(temp), "-%d", pnum);
2214 0 : strlcat(proppath, temp, proppath_size);
2215 0 : }
2216 :
2217 : /**
2218 : * drm_dp_mst_connector_late_register() - Late MST connector registration
2219 : * @connector: The MST connector
2220 : * @port: The MST port for this connector
2221 : *
2222 : * Helper to register the remote aux device for this MST port. Drivers should
2223 : * call this from their mst connector's late_register hook to enable MST aux
2224 : * devices.
2225 : *
2226 : * Return: 0 on success, negative error code on failure.
2227 : */
2228 0 : int drm_dp_mst_connector_late_register(struct drm_connector *connector,
2229 : struct drm_dp_mst_port *port)
2230 : {
2231 0 : drm_dbg_kms(port->mgr->dev, "registering %s remote bus for %s\n",
2232 : port->aux.name, connector->kdev->kobj.name);
2233 :
2234 0 : port->aux.dev = connector->kdev;
2235 0 : return drm_dp_aux_register_devnode(&port->aux);
2236 : }
2237 : EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
2238 :
2239 : /**
2240 : * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
2241 : * @connector: The MST connector
2242 : * @port: The MST port for this connector
2243 : *
2244 : * Helper to unregister the remote aux device for this MST port, registered by
2245 : * drm_dp_mst_connector_late_register(). Drivers should call this from their mst
2246 : * connector's early_unregister hook.
2247 : */
2248 0 : void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
2249 : struct drm_dp_mst_port *port)
2250 : {
2251 0 : drm_dbg_kms(port->mgr->dev, "unregistering %s remote bus for %s\n",
2252 : port->aux.name, connector->kdev->kobj.name);
2253 0 : drm_dp_aux_unregister_devnode(&port->aux);
2254 0 : }
2255 : EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
2256 :
2257 : static void
2258 0 : drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
2259 : struct drm_dp_mst_port *port)
2260 : {
2261 0 : struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2262 : char proppath[255];
2263 : int ret;
2264 :
2265 0 : build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
2266 0 : port->connector = mgr->cbs->add_connector(mgr, port, proppath);
2267 0 : if (!port->connector) {
2268 0 : ret = -ENOMEM;
2269 : goto error;
2270 : }
2271 :
2272 0 : if (port->pdt != DP_PEER_DEVICE_NONE &&
2273 0 : drm_dp_mst_is_end_device(port->pdt, port->mcs) &&
2274 0 : port->port_num >= DP_MST_LOGICAL_PORT_0)
2275 0 : port->cached_edid = drm_edid_read_ddc(port->connector,
2276 : &port->aux.ddc);
2277 :
2278 0 : drm_connector_register(port->connector);
2279 0 : return;
2280 :
2281 : error:
2282 0 : drm_err(mgr->dev, "Failed to create connector for port %p: %d\n", port, ret);
2283 : }
2284 :
2285 : /*
2286 : * Drop a topology reference, and unlink the port from the in-memory topology
2287 : * layout
2288 : */
2289 : static void
2290 0 : drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr,
2291 : struct drm_dp_mst_port *port)
2292 : {
2293 0 : mutex_lock(&mgr->lock);
2294 0 : port->parent->num_ports--;
2295 0 : list_del(&port->next);
2296 0 : mutex_unlock(&mgr->lock);
2297 0 : drm_dp_mst_topology_put_port(port);
2298 0 : }
2299 :
2300 : static struct drm_dp_mst_port *
2301 0 : drm_dp_mst_add_port(struct drm_device *dev,
2302 : struct drm_dp_mst_topology_mgr *mgr,
2303 : struct drm_dp_mst_branch *mstb, u8 port_number)
2304 : {
2305 0 : struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
2306 :
2307 0 : if (!port)
2308 : return NULL;
2309 :
2310 0 : kref_init(&port->topology_kref);
2311 0 : kref_init(&port->malloc_kref);
2312 0 : port->parent = mstb;
2313 0 : port->port_num = port_number;
2314 0 : port->mgr = mgr;
2315 0 : port->aux.name = "DPMST";
2316 0 : port->aux.dev = dev->dev;
2317 0 : port->aux.is_remote = true;
2318 :
2319 : /* initialize the MST downstream port's AUX crc work queue */
2320 0 : port->aux.drm_dev = dev;
2321 0 : drm_dp_remote_aux_init(&port->aux);
2322 :
2323 : /*
2324 : * Make sure the memory allocation for our parent branch stays
2325 : * around until our own memory allocation is released
2326 : */
2327 0 : drm_dp_mst_get_mstb_malloc(mstb);
2328 :
2329 0 : return port;
2330 : }
2331 :
2332 : static int
2333 0 : drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
2334 : struct drm_device *dev,
2335 : struct drm_dp_link_addr_reply_port *port_msg)
2336 : {
2337 0 : struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2338 : struct drm_dp_mst_port *port;
2339 0 : int old_ddps = 0, ret;
2340 0 : u8 new_pdt = DP_PEER_DEVICE_NONE;
2341 0 : bool new_mcs = 0;
2342 0 : bool created = false, send_link_addr = false, changed = false;
2343 :
2344 0 : port = drm_dp_get_port(mstb, port_msg->port_number);
2345 0 : if (!port) {
2346 0 : port = drm_dp_mst_add_port(dev, mgr, mstb,
2347 0 : port_msg->port_number);
2348 0 : if (!port)
2349 : return -ENOMEM;
2350 : created = true;
2351 : changed = true;
2352 0 : } else if (!port->input && port_msg->input_port && port->connector) {
2353 : /* Since port->connector can't be changed here, we create a
2354 : * new port if input_port changes from 0 to 1
2355 : */
2356 0 : drm_dp_mst_topology_unlink_port(mgr, port);
2357 0 : drm_dp_mst_topology_put_port(port);
2358 0 : port = drm_dp_mst_add_port(dev, mgr, mstb,
2359 0 : port_msg->port_number);
2360 0 : if (!port)
2361 : return -ENOMEM;
2362 : changed = true;
2363 : created = true;
2364 0 : } else if (port->input && !port_msg->input_port) {
2365 : changed = true;
2366 0 : } else if (port->connector) {
2367 : /* We're updating a port that's exposed to userspace, so do it
2368 : * under lock
2369 : */
2370 0 : drm_modeset_lock(&mgr->base.lock, NULL);
2371 :
2372 0 : old_ddps = port->ddps;
2373 0 : changed = port->ddps != port_msg->ddps ||
2374 0 : (port->ddps &&
2375 0 : (port->ldps != port_msg->legacy_device_plug_status ||
2376 0 : port->dpcd_rev != port_msg->dpcd_revision ||
2377 0 : port->mcs != port_msg->mcs ||
2378 0 : port->pdt != port_msg->peer_device_type ||
2379 0 : port->num_sdp_stream_sinks !=
2380 0 : port_msg->num_sdp_stream_sinks));
2381 : }
2382 :
2383 0 : port->input = port_msg->input_port;
2384 0 : if (!port->input)
2385 0 : new_pdt = port_msg->peer_device_type;
2386 0 : new_mcs = port_msg->mcs;
2387 0 : port->ddps = port_msg->ddps;
2388 0 : port->ldps = port_msg->legacy_device_plug_status;
2389 0 : port->dpcd_rev = port_msg->dpcd_revision;
2390 0 : port->num_sdp_streams = port_msg->num_sdp_streams;
2391 0 : port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
2392 :
2393 : /* manage mstb port lists with mgr lock - take a reference
2394 : for this list */
2395 0 : if (created) {
2396 0 : mutex_lock(&mgr->lock);
2397 0 : drm_dp_mst_topology_get_port(port);
2398 0 : list_add(&port->next, &mstb->ports);
2399 0 : mstb->num_ports++;
2400 0 : mutex_unlock(&mgr->lock);
2401 : }
2402 :
2403 : /*
2404 : * Reprobe PBN caps on both hotplug, and when re-probing the link
2405 : * for our parent mstb
2406 : */
2407 0 : if (old_ddps != port->ddps || !created) {
2408 0 : if (port->ddps && !port->input) {
2409 0 : ret = drm_dp_send_enum_path_resources(mgr, mstb,
2410 : port);
2411 0 : if (ret == 1)
2412 0 : changed = true;
2413 : } else {
2414 0 : port->full_pbn = 0;
2415 : }
2416 : }
2417 :
2418 0 : ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2419 0 : if (ret == 1) {
2420 : send_link_addr = true;
2421 0 : } else if (ret < 0) {
2422 0 : drm_err(dev, "Failed to change PDT on port %p: %d\n", port, ret);
2423 : goto fail;
2424 : }
2425 :
2426 : /*
2427 : * If this port wasn't just created, then we're reprobing because
2428 : * we're coming out of suspend. In this case, always resend the link
2429 : * address if there's an MSTB on this port
2430 : */
2431 0 : if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
2432 0 : port->mcs)
2433 0 : send_link_addr = true;
2434 :
2435 0 : if (port->connector)
2436 0 : drm_modeset_unlock(&mgr->base.lock);
2437 0 : else if (!port->input)
2438 0 : drm_dp_mst_port_add_connector(mstb, port);
2439 :
2440 0 : if (send_link_addr && port->mstb) {
2441 0 : ret = drm_dp_send_link_address(mgr, port->mstb);
2442 0 : if (ret == 1) /* MSTB below us changed */
2443 : changed = true;
2444 0 : else if (ret < 0)
2445 : goto fail_put;
2446 : }
2447 :
2448 : /* put reference to this port */
2449 0 : drm_dp_mst_topology_put_port(port);
2450 0 : return changed;
2451 :
2452 : fail:
2453 0 : drm_dp_mst_topology_unlink_port(mgr, port);
2454 0 : if (port->connector)
2455 0 : drm_modeset_unlock(&mgr->base.lock);
2456 : fail_put:
2457 0 : drm_dp_mst_topology_put_port(port);
2458 0 : return ret;
2459 : }
2460 :
2461 : static int
2462 0 : drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
2463 : struct drm_dp_connection_status_notify *conn_stat)
2464 : {
2465 0 : struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2466 : struct drm_dp_mst_port *port;
2467 : int old_ddps, ret;
2468 : u8 new_pdt;
2469 : bool new_mcs;
2470 0 : bool dowork = false, create_connector = false;
2471 :
2472 0 : port = drm_dp_get_port(mstb, conn_stat->port_number);
2473 0 : if (!port)
2474 : return 0;
2475 :
2476 0 : if (port->connector) {
2477 0 : if (!port->input && conn_stat->input_port) {
2478 : /*
2479 : * We can't remove a connector from an already exposed
2480 : * port, so just throw the port out and make sure we
2481 : * reprobe the link address of it's parent MSTB
2482 : */
2483 0 : drm_dp_mst_topology_unlink_port(mgr, port);
2484 0 : mstb->link_address_sent = false;
2485 0 : dowork = true;
2486 0 : goto out;
2487 : }
2488 :
2489 : /* Locking is only needed if the port's exposed to userspace */
2490 0 : drm_modeset_lock(&mgr->base.lock, NULL);
2491 0 : } else if (port->input && !conn_stat->input_port) {
2492 0 : create_connector = true;
2493 : /* Reprobe link address so we get num_sdp_streams */
2494 0 : mstb->link_address_sent = false;
2495 0 : dowork = true;
2496 : }
2497 :
2498 0 : old_ddps = port->ddps;
2499 0 : port->input = conn_stat->input_port;
2500 0 : port->ldps = conn_stat->legacy_device_plug_status;
2501 0 : port->ddps = conn_stat->displayport_device_plug_status;
2502 :
2503 0 : if (old_ddps != port->ddps) {
2504 0 : if (port->ddps && !port->input)
2505 0 : drm_dp_send_enum_path_resources(mgr, mstb, port);
2506 : else
2507 0 : port->full_pbn = 0;
2508 : }
2509 :
2510 0 : new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
2511 0 : new_mcs = conn_stat->message_capability_status;
2512 0 : ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2513 0 : if (ret == 1) {
2514 : dowork = true;
2515 0 : } else if (ret < 0) {
2516 0 : drm_err(mgr->dev, "Failed to change PDT for port %p: %d\n", port, ret);
2517 0 : dowork = false;
2518 : }
2519 :
2520 0 : if (port->connector)
2521 0 : drm_modeset_unlock(&mgr->base.lock);
2522 0 : else if (create_connector)
2523 0 : drm_dp_mst_port_add_connector(mstb, port);
2524 :
2525 : out:
2526 0 : drm_dp_mst_topology_put_port(port);
2527 0 : return dowork;
2528 : }
2529 :
2530 0 : static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
2531 : u8 lct, u8 *rad)
2532 : {
2533 : struct drm_dp_mst_branch *mstb;
2534 : struct drm_dp_mst_port *port;
2535 : int i, ret;
2536 : /* find the port by iterating down */
2537 :
2538 0 : mutex_lock(&mgr->lock);
2539 0 : mstb = mgr->mst_primary;
2540 :
2541 0 : if (!mstb)
2542 : goto out;
2543 :
2544 0 : for (i = 0; i < lct - 1; i++) {
2545 0 : int shift = (i % 2) ? 0 : 4;
2546 0 : int port_num = (rad[i / 2] >> shift) & 0xf;
2547 :
2548 0 : list_for_each_entry(port, &mstb->ports, next) {
2549 0 : if (port->port_num == port_num) {
2550 0 : mstb = port->mstb;
2551 0 : if (!mstb) {
2552 0 : drm_err(mgr->dev,
2553 : "failed to lookup MSTB with lct %d, rad %02x\n",
2554 : lct, rad[0]);
2555 0 : goto out;
2556 : }
2557 :
2558 : break;
2559 : }
2560 : }
2561 : }
2562 0 : ret = drm_dp_mst_topology_try_get_mstb(mstb);
2563 0 : if (!ret)
2564 0 : mstb = NULL;
2565 : out:
2566 0 : mutex_unlock(&mgr->lock);
2567 0 : return mstb;
2568 : }
2569 :
2570 0 : static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
2571 : struct drm_dp_mst_branch *mstb,
2572 : const uint8_t *guid)
2573 : {
2574 : struct drm_dp_mst_branch *found_mstb;
2575 : struct drm_dp_mst_port *port;
2576 :
2577 0 : if (memcmp(mstb->guid, guid, 16) == 0)
2578 : return mstb;
2579 :
2580 :
2581 0 : list_for_each_entry(port, &mstb->ports, next) {
2582 0 : if (!port->mstb)
2583 0 : continue;
2584 :
2585 0 : found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
2586 :
2587 0 : if (found_mstb)
2588 : return found_mstb;
2589 : }
2590 :
2591 : return NULL;
2592 : }
2593 :
2594 : static struct drm_dp_mst_branch *
2595 0 : drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
2596 : const uint8_t *guid)
2597 : {
2598 : struct drm_dp_mst_branch *mstb;
2599 : int ret;
2600 :
2601 : /* find the port by iterating down */
2602 0 : mutex_lock(&mgr->lock);
2603 :
2604 0 : mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
2605 0 : if (mstb) {
2606 0 : ret = drm_dp_mst_topology_try_get_mstb(mstb);
2607 0 : if (!ret)
2608 0 : mstb = NULL;
2609 : }
2610 :
2611 0 : mutex_unlock(&mgr->lock);
2612 0 : return mstb;
2613 : }
2614 :
2615 0 : static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2616 : struct drm_dp_mst_branch *mstb)
2617 : {
2618 : struct drm_dp_mst_port *port;
2619 : int ret;
2620 0 : bool changed = false;
2621 :
2622 0 : if (!mstb->link_address_sent) {
2623 0 : ret = drm_dp_send_link_address(mgr, mstb);
2624 0 : if (ret == 1)
2625 : changed = true;
2626 0 : else if (ret < 0)
2627 : return ret;
2628 : }
2629 :
2630 0 : list_for_each_entry(port, &mstb->ports, next) {
2631 0 : if (port->input || !port->ddps || !port->mstb)
2632 0 : continue;
2633 :
2634 0 : ret = drm_dp_check_and_send_link_address(mgr, port->mstb);
2635 0 : if (ret == 1)
2636 : changed = true;
2637 0 : else if (ret < 0)
2638 : return ret;
2639 : }
2640 :
2641 0 : return changed;
2642 : }
2643 :
2644 0 : static void drm_dp_mst_link_probe_work(struct work_struct *work)
2645 : {
2646 0 : struct drm_dp_mst_topology_mgr *mgr =
2647 0 : container_of(work, struct drm_dp_mst_topology_mgr, work);
2648 0 : struct drm_device *dev = mgr->dev;
2649 : struct drm_dp_mst_branch *mstb;
2650 : int ret;
2651 : bool clear_payload_id_table;
2652 :
2653 0 : mutex_lock(&mgr->probe_lock);
2654 :
2655 0 : mutex_lock(&mgr->lock);
2656 0 : clear_payload_id_table = !mgr->payload_id_table_cleared;
2657 0 : mgr->payload_id_table_cleared = true;
2658 :
2659 0 : mstb = mgr->mst_primary;
2660 0 : if (mstb) {
2661 0 : ret = drm_dp_mst_topology_try_get_mstb(mstb);
2662 0 : if (!ret)
2663 0 : mstb = NULL;
2664 : }
2665 0 : mutex_unlock(&mgr->lock);
2666 0 : if (!mstb) {
2667 0 : mutex_unlock(&mgr->probe_lock);
2668 0 : return;
2669 : }
2670 :
2671 : /*
2672 : * Certain branch devices seem to incorrectly report an available_pbn
2673 : * of 0 on downstream sinks, even after clearing the
2674 : * DP_PAYLOAD_ALLOCATE_* registers in
2675 : * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
2676 : * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
2677 : * things work again.
2678 : */
2679 0 : if (clear_payload_id_table) {
2680 0 : drm_dbg_kms(dev, "Clearing payload ID table\n");
2681 0 : drm_dp_send_clear_payload_id_table(mgr, mstb);
2682 : }
2683 :
2684 0 : ret = drm_dp_check_and_send_link_address(mgr, mstb);
2685 0 : drm_dp_mst_topology_put_mstb(mstb);
2686 :
2687 0 : mutex_unlock(&mgr->probe_lock);
2688 0 : if (ret > 0)
2689 0 : drm_kms_helper_hotplug_event(dev);
2690 : }
2691 :
2692 0 : static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
2693 : u8 *guid)
2694 : {
2695 : u64 salt;
2696 :
2697 0 : if (memchr_inv(guid, 0, 16))
2698 : return true;
2699 :
2700 0 : salt = get_jiffies_64();
2701 :
2702 0 : memcpy(&guid[0], &salt, sizeof(u64));
2703 0 : memcpy(&guid[8], &salt, sizeof(u64));
2704 :
2705 : return false;
2706 : }
2707 :
2708 0 : static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg,
2709 : u8 port_num, u32 offset, u8 num_bytes)
2710 : {
2711 : struct drm_dp_sideband_msg_req_body req;
2712 :
2713 0 : req.req_type = DP_REMOTE_DPCD_READ;
2714 0 : req.u.dpcd_read.port_number = port_num;
2715 0 : req.u.dpcd_read.dpcd_address = offset;
2716 0 : req.u.dpcd_read.num_bytes = num_bytes;
2717 0 : drm_dp_encode_sideband_req(&req, msg);
2718 0 : }
2719 :
2720 0 : static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
2721 : bool up, u8 *msg, int len)
2722 : {
2723 : int ret;
2724 0 : int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
2725 : int tosend, total, offset;
2726 0 : int retries = 0;
2727 :
2728 : retry:
2729 0 : total = len;
2730 0 : offset = 0;
2731 : do {
2732 0 : tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
2733 :
2734 0 : ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
2735 0 : &msg[offset],
2736 : tosend);
2737 0 : if (ret != tosend) {
2738 0 : if (ret == -EIO && retries < 5) {
2739 0 : retries++;
2740 0 : goto retry;
2741 : }
2742 0 : drm_dbg_kms(mgr->dev, "failed to dpcd write %d %d\n", tosend, ret);
2743 :
2744 0 : return -EIO;
2745 : }
2746 0 : offset += tosend;
2747 0 : total -= tosend;
2748 0 : } while (total > 0);
2749 : return 0;
2750 : }
2751 :
2752 0 : static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
2753 : struct drm_dp_sideband_msg_tx *txmsg)
2754 : {
2755 0 : struct drm_dp_mst_branch *mstb = txmsg->dst;
2756 : u8 req_type;
2757 :
2758 0 : req_type = txmsg->msg[0] & 0x7f;
2759 0 : if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
2760 0 : req_type == DP_RESOURCE_STATUS_NOTIFY ||
2761 : req_type == DP_CLEAR_PAYLOAD_ID_TABLE)
2762 0 : hdr->broadcast = 1;
2763 : else
2764 0 : hdr->broadcast = 0;
2765 0 : hdr->path_msg = txmsg->path_msg;
2766 0 : if (hdr->broadcast) {
2767 0 : hdr->lct = 1;
2768 0 : hdr->lcr = 6;
2769 : } else {
2770 0 : hdr->lct = mstb->lct;
2771 0 : hdr->lcr = mstb->lct - 1;
2772 : }
2773 :
2774 0 : memcpy(hdr->rad, mstb->rad, hdr->lct / 2);
2775 :
2776 0 : return 0;
2777 : }
2778 : /*
2779 : * process a single block of the next message in the sideband queue
2780 : */
2781 0 : static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2782 : struct drm_dp_sideband_msg_tx *txmsg,
2783 : bool up)
2784 : {
2785 : u8 chunk[48];
2786 : struct drm_dp_sideband_msg_hdr hdr;
2787 : int len, space, idx, tosend;
2788 : int ret;
2789 :
2790 0 : if (txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
2791 : return 0;
2792 :
2793 0 : memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
2794 :
2795 0 : if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED)
2796 0 : txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
2797 :
2798 : /* make hdr from dst mst */
2799 0 : ret = set_hdr_from_dst_qlock(&hdr, txmsg);
2800 0 : if (ret < 0)
2801 : return ret;
2802 :
2803 : /* amount left to send in this message */
2804 0 : len = txmsg->cur_len - txmsg->cur_offset;
2805 :
2806 : /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
2807 0 : space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
2808 :
2809 0 : tosend = min(len, space);
2810 0 : if (len == txmsg->cur_len)
2811 0 : hdr.somt = 1;
2812 0 : if (space >= len)
2813 0 : hdr.eomt = 1;
2814 :
2815 :
2816 0 : hdr.msg_len = tosend + 1;
2817 0 : drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
2818 0 : memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
2819 : /* add crc at end */
2820 0 : drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
2821 0 : idx += tosend + 1;
2822 :
2823 0 : ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
2824 0 : if (ret) {
2825 0 : if (drm_debug_enabled(DRM_UT_DP)) {
2826 0 : struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2827 :
2828 0 : drm_printf(&p, "sideband msg failed to send\n");
2829 0 : drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2830 : }
2831 : return ret;
2832 : }
2833 :
2834 0 : txmsg->cur_offset += tosend;
2835 0 : if (txmsg->cur_offset == txmsg->cur_len) {
2836 0 : txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
2837 0 : return 1;
2838 : }
2839 : return 0;
2840 : }
2841 :
2842 0 : static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
2843 : {
2844 : struct drm_dp_sideband_msg_tx *txmsg;
2845 : int ret;
2846 :
2847 0 : WARN_ON(!mutex_is_locked(&mgr->qlock));
2848 :
2849 : /* construct a chunk from the first msg in the tx_msg queue */
2850 0 : if (list_empty(&mgr->tx_msg_downq))
2851 : return;
2852 :
2853 0 : txmsg = list_first_entry(&mgr->tx_msg_downq,
2854 : struct drm_dp_sideband_msg_tx, next);
2855 0 : ret = process_single_tx_qlock(mgr, txmsg, false);
2856 0 : if (ret < 0) {
2857 0 : drm_dbg_kms(mgr->dev, "failed to send msg in q %d\n", ret);
2858 0 : list_del(&txmsg->next);
2859 0 : txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
2860 0 : wake_up_all(&mgr->tx_waitq);
2861 : }
2862 : }
2863 :
2864 0 : static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
2865 : struct drm_dp_sideband_msg_tx *txmsg)
2866 : {
2867 0 : mutex_lock(&mgr->qlock);
2868 0 : list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
2869 :
2870 0 : if (drm_debug_enabled(DRM_UT_DP)) {
2871 0 : struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2872 :
2873 0 : drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2874 : }
2875 :
2876 0 : if (list_is_singular(&mgr->tx_msg_downq))
2877 0 : process_single_down_tx_qlock(mgr);
2878 0 : mutex_unlock(&mgr->qlock);
2879 0 : }
2880 :
2881 : static void
2882 0 : drm_dp_dump_link_address(const struct drm_dp_mst_topology_mgr *mgr,
2883 : struct drm_dp_link_address_ack_reply *reply)
2884 : {
2885 : struct drm_dp_link_addr_reply_port *port_reply;
2886 : int i;
2887 :
2888 0 : for (i = 0; i < reply->nports; i++) {
2889 0 : port_reply = &reply->ports[i];
2890 0 : drm_dbg_kms(mgr->dev,
2891 : "port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n",
2892 : i,
2893 : port_reply->input_port,
2894 : port_reply->peer_device_type,
2895 : port_reply->port_number,
2896 : port_reply->dpcd_revision,
2897 : port_reply->mcs,
2898 : port_reply->ddps,
2899 : port_reply->legacy_device_plug_status,
2900 : port_reply->num_sdp_streams,
2901 : port_reply->num_sdp_stream_sinks);
2902 : }
2903 0 : }
2904 :
2905 0 : static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2906 : struct drm_dp_mst_branch *mstb)
2907 : {
2908 : struct drm_dp_sideband_msg_tx *txmsg;
2909 : struct drm_dp_link_address_ack_reply *reply;
2910 : struct drm_dp_mst_port *port, *tmp;
2911 0 : int i, ret, port_mask = 0;
2912 0 : bool changed = false;
2913 :
2914 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2915 0 : if (!txmsg)
2916 : return -ENOMEM;
2917 :
2918 0 : txmsg->dst = mstb;
2919 0 : build_link_address(txmsg);
2920 :
2921 0 : mstb->link_address_sent = true;
2922 0 : drm_dp_queue_down_tx(mgr, txmsg);
2923 :
2924 : /* FIXME: Actually do some real error handling here */
2925 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2926 0 : if (ret <= 0) {
2927 0 : drm_err(mgr->dev, "Sending link address failed with %d\n", ret);
2928 0 : goto out;
2929 : }
2930 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2931 0 : drm_err(mgr->dev, "link address NAK received\n");
2932 0 : ret = -EIO;
2933 0 : goto out;
2934 : }
2935 :
2936 0 : reply = &txmsg->reply.u.link_addr;
2937 0 : drm_dbg_kms(mgr->dev, "link address reply: %d\n", reply->nports);
2938 0 : drm_dp_dump_link_address(mgr, reply);
2939 :
2940 0 : ret = drm_dp_check_mstb_guid(mstb, reply->guid);
2941 0 : if (ret) {
2942 : char buf[64];
2943 :
2944 0 : drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf));
2945 0 : drm_err(mgr->dev, "GUID check on %s failed: %d\n", buf, ret);
2946 : goto out;
2947 : }
2948 :
2949 0 : for (i = 0; i < reply->nports; i++) {
2950 0 : port_mask |= BIT(reply->ports[i].port_number);
2951 0 : ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev,
2952 : &reply->ports[i]);
2953 0 : if (ret == 1)
2954 : changed = true;
2955 0 : else if (ret < 0)
2956 : goto out;
2957 : }
2958 :
2959 : /* Prune any ports that are currently a part of mstb in our in-memory
2960 : * topology, but were not seen in this link address. Usually this
2961 : * means that they were removed while the topology was out of sync,
2962 : * e.g. during suspend/resume
2963 : */
2964 0 : mutex_lock(&mgr->lock);
2965 0 : list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
2966 0 : if (port_mask & BIT(port->port_num))
2967 0 : continue;
2968 :
2969 0 : drm_dbg_kms(mgr->dev, "port %d was not in link address, removing\n",
2970 : port->port_num);
2971 0 : list_del(&port->next);
2972 0 : drm_dp_mst_topology_put_port(port);
2973 0 : changed = true;
2974 : }
2975 0 : mutex_unlock(&mgr->lock);
2976 :
2977 : out:
2978 0 : if (ret <= 0)
2979 0 : mstb->link_address_sent = false;
2980 0 : kfree(txmsg);
2981 0 : return ret < 0 ? ret : changed;
2982 : }
2983 :
2984 : static void
2985 0 : drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
2986 : struct drm_dp_mst_branch *mstb)
2987 : {
2988 : struct drm_dp_sideband_msg_tx *txmsg;
2989 : int ret;
2990 :
2991 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2992 0 : if (!txmsg)
2993 : return;
2994 :
2995 0 : txmsg->dst = mstb;
2996 0 : build_clear_payload_id_table(txmsg);
2997 :
2998 0 : drm_dp_queue_down_tx(mgr, txmsg);
2999 :
3000 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3001 0 : if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3002 0 : drm_dbg_kms(mgr->dev, "clear payload table id nak received\n");
3003 :
3004 0 : kfree(txmsg);
3005 : }
3006 :
3007 : static int
3008 0 : drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
3009 : struct drm_dp_mst_branch *mstb,
3010 : struct drm_dp_mst_port *port)
3011 : {
3012 : struct drm_dp_enum_path_resources_ack_reply *path_res;
3013 : struct drm_dp_sideband_msg_tx *txmsg;
3014 : int ret;
3015 :
3016 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3017 0 : if (!txmsg)
3018 : return -ENOMEM;
3019 :
3020 0 : txmsg->dst = mstb;
3021 0 : build_enum_path_resources(txmsg, port->port_num);
3022 :
3023 0 : drm_dp_queue_down_tx(mgr, txmsg);
3024 :
3025 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3026 0 : if (ret > 0) {
3027 0 : ret = 0;
3028 0 : path_res = &txmsg->reply.u.path_resources;
3029 :
3030 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3031 0 : drm_dbg_kms(mgr->dev, "enum path resources nak received\n");
3032 : } else {
3033 0 : if (port->port_num != path_res->port_number)
3034 0 : DRM_ERROR("got incorrect port in response\n");
3035 :
3036 0 : drm_dbg_kms(mgr->dev, "enum path resources %d: %d %d\n",
3037 : path_res->port_number,
3038 : path_res->full_payload_bw_number,
3039 : path_res->avail_payload_bw_number);
3040 :
3041 : /*
3042 : * If something changed, make sure we send a
3043 : * hotplug
3044 : */
3045 0 : if (port->full_pbn != path_res->full_payload_bw_number ||
3046 0 : port->fec_capable != path_res->fec_capable)
3047 0 : ret = 1;
3048 :
3049 0 : port->full_pbn = path_res->full_payload_bw_number;
3050 0 : port->fec_capable = path_res->fec_capable;
3051 : }
3052 : }
3053 :
3054 0 : kfree(txmsg);
3055 0 : return ret;
3056 : }
3057 :
3058 0 : static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
3059 : {
3060 0 : if (!mstb->port_parent)
3061 : return NULL;
3062 :
3063 0 : if (mstb->port_parent->mstb != mstb)
3064 : return mstb->port_parent;
3065 :
3066 0 : return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
3067 : }
3068 :
3069 : /*
3070 : * Searches upwards in the topology starting from mstb to try to find the
3071 : * closest available parent of mstb that's still connected to the rest of the
3072 : * topology. This can be used in order to perform operations like releasing
3073 : * payloads, where the branch device which owned the payload may no longer be
3074 : * around and thus would require that the payload on the last living relative
3075 : * be freed instead.
3076 : */
3077 : static struct drm_dp_mst_branch *
3078 0 : drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
3079 : struct drm_dp_mst_branch *mstb,
3080 : int *port_num)
3081 : {
3082 0 : struct drm_dp_mst_branch *rmstb = NULL;
3083 : struct drm_dp_mst_port *found_port;
3084 :
3085 0 : mutex_lock(&mgr->lock);
3086 0 : if (!mgr->mst_primary)
3087 : goto out;
3088 :
3089 : do {
3090 0 : found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
3091 0 : if (!found_port)
3092 : break;
3093 :
3094 0 : if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
3095 0 : rmstb = found_port->parent;
3096 0 : *port_num = found_port->port_num;
3097 : } else {
3098 : /* Search again, starting from this parent */
3099 0 : mstb = found_port->parent;
3100 : }
3101 0 : } while (!rmstb);
3102 : out:
3103 0 : mutex_unlock(&mgr->lock);
3104 0 : return rmstb;
3105 : }
3106 :
3107 0 : static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
3108 : struct drm_dp_mst_port *port,
3109 : int id,
3110 : int pbn)
3111 : {
3112 : struct drm_dp_sideband_msg_tx *txmsg;
3113 : struct drm_dp_mst_branch *mstb;
3114 : int ret, port_num;
3115 : u8 sinks[DRM_DP_MAX_SDP_STREAMS];
3116 : int i;
3117 :
3118 0 : port_num = port->port_num;
3119 0 : mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3120 0 : if (!mstb) {
3121 0 : mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
3122 : port->parent,
3123 : &port_num);
3124 :
3125 0 : if (!mstb)
3126 : return -EINVAL;
3127 : }
3128 :
3129 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3130 0 : if (!txmsg) {
3131 : ret = -ENOMEM;
3132 : goto fail_put;
3133 : }
3134 :
3135 0 : for (i = 0; i < port->num_sdp_streams; i++)
3136 0 : sinks[i] = i;
3137 :
3138 0 : txmsg->dst = mstb;
3139 0 : build_allocate_payload(txmsg, port_num,
3140 : id,
3141 : pbn, port->num_sdp_streams, sinks);
3142 :
3143 0 : drm_dp_queue_down_tx(mgr, txmsg);
3144 :
3145 : /*
3146 : * FIXME: there is a small chance that between getting the last
3147 : * connected mstb and sending the payload message, the last connected
3148 : * mstb could also be removed from the topology. In the future, this
3149 : * needs to be fixed by restarting the
3150 : * drm_dp_get_last_connected_port_and_mstb() search in the event of a
3151 : * timeout if the topology is still connected to the system.
3152 : */
3153 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3154 0 : if (ret > 0) {
3155 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3156 : ret = -EINVAL;
3157 : else
3158 0 : ret = 0;
3159 : }
3160 0 : kfree(txmsg);
3161 : fail_put:
3162 0 : drm_dp_mst_topology_put_mstb(mstb);
3163 0 : return ret;
3164 : }
3165 :
3166 0 : int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
3167 : struct drm_dp_mst_port *port, bool power_up)
3168 : {
3169 : struct drm_dp_sideband_msg_tx *txmsg;
3170 : int ret;
3171 :
3172 0 : port = drm_dp_mst_topology_get_port_validated(mgr, port);
3173 0 : if (!port)
3174 : return -EINVAL;
3175 :
3176 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3177 0 : if (!txmsg) {
3178 0 : drm_dp_mst_topology_put_port(port);
3179 0 : return -ENOMEM;
3180 : }
3181 :
3182 0 : txmsg->dst = port->parent;
3183 0 : build_power_updown_phy(txmsg, port->port_num, power_up);
3184 0 : drm_dp_queue_down_tx(mgr, txmsg);
3185 :
3186 0 : ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
3187 0 : if (ret > 0) {
3188 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3189 : ret = -EINVAL;
3190 : else
3191 0 : ret = 0;
3192 : }
3193 0 : kfree(txmsg);
3194 0 : drm_dp_mst_topology_put_port(port);
3195 :
3196 0 : return ret;
3197 : }
3198 : EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
3199 :
3200 0 : int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr,
3201 : struct drm_dp_mst_port *port,
3202 : struct drm_dp_query_stream_enc_status_ack_reply *status)
3203 : {
3204 : struct drm_dp_mst_topology_state *state;
3205 : struct drm_dp_mst_atomic_payload *payload;
3206 : struct drm_dp_sideband_msg_tx *txmsg;
3207 : u8 nonce[7];
3208 : int ret;
3209 :
3210 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3211 0 : if (!txmsg)
3212 : return -ENOMEM;
3213 :
3214 0 : port = drm_dp_mst_topology_get_port_validated(mgr, port);
3215 0 : if (!port) {
3216 : ret = -EINVAL;
3217 : goto out_get_port;
3218 : }
3219 :
3220 0 : get_random_bytes(nonce, sizeof(nonce));
3221 :
3222 0 : drm_modeset_lock(&mgr->base.lock, NULL);
3223 0 : state = to_drm_dp_mst_topology_state(mgr->base.state);
3224 0 : payload = drm_atomic_get_mst_payload_state(state, port);
3225 :
3226 : /*
3227 : * "Source device targets the QUERY_STREAM_ENCRYPTION_STATUS message
3228 : * transaction at the MST Branch device directly connected to the
3229 : * Source"
3230 : */
3231 0 : txmsg->dst = mgr->mst_primary;
3232 :
3233 0 : build_query_stream_enc_status(txmsg, payload->vcpi, nonce);
3234 :
3235 0 : drm_dp_queue_down_tx(mgr, txmsg);
3236 :
3237 0 : ret = drm_dp_mst_wait_tx_reply(mgr->mst_primary, txmsg);
3238 0 : if (ret < 0) {
3239 : goto out;
3240 0 : } else if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3241 0 : drm_dbg_kms(mgr->dev, "query encryption status nak received\n");
3242 0 : ret = -ENXIO;
3243 0 : goto out;
3244 : }
3245 :
3246 0 : ret = 0;
3247 0 : memcpy(status, &txmsg->reply.u.enc_status, sizeof(*status));
3248 :
3249 : out:
3250 0 : drm_modeset_unlock(&mgr->base.lock);
3251 0 : drm_dp_mst_topology_put_port(port);
3252 : out_get_port:
3253 0 : kfree(txmsg);
3254 0 : return ret;
3255 : }
3256 : EXPORT_SYMBOL(drm_dp_send_query_stream_enc_status);
3257 :
3258 : static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3259 : struct drm_dp_mst_atomic_payload *payload)
3260 : {
3261 0 : return drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot,
3262 : payload->time_slots);
3263 : }
3264 :
3265 0 : static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3266 : struct drm_dp_mst_atomic_payload *payload)
3267 : {
3268 : int ret;
3269 0 : struct drm_dp_mst_port *port = drm_dp_mst_topology_get_port_validated(mgr, payload->port);
3270 :
3271 0 : if (!port)
3272 : return -EIO;
3273 :
3274 0 : ret = drm_dp_payload_send_msg(mgr, port, payload->vcpi, payload->pbn);
3275 0 : drm_dp_mst_topology_put_port(port);
3276 0 : return ret;
3277 : }
3278 :
3279 0 : static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3280 : struct drm_dp_mst_topology_state *mst_state,
3281 : struct drm_dp_mst_atomic_payload *payload)
3282 : {
3283 0 : drm_dbg_kms(mgr->dev, "\n");
3284 :
3285 : /* it's okay for these to fail */
3286 0 : drm_dp_payload_send_msg(mgr, payload->port, payload->vcpi, 0);
3287 0 : drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot, 0);
3288 :
3289 0 : return 0;
3290 : }
3291 :
3292 : /**
3293 : * drm_dp_add_payload_part1() - Execute payload update part 1
3294 : * @mgr: Manager to use.
3295 : * @mst_state: The MST atomic state
3296 : * @payload: The payload to write
3297 : *
3298 : * Determines the starting time slot for the given payload, and programs the VCPI for this payload
3299 : * into hardware. After calling this, the driver should generate ACT and payload packets.
3300 : *
3301 : * Returns: 0 on success, error code on failure. In the event that this fails,
3302 : * @payload.vc_start_slot will also be set to -1.
3303 : */
3304 0 : int drm_dp_add_payload_part1(struct drm_dp_mst_topology_mgr *mgr,
3305 : struct drm_dp_mst_topology_state *mst_state,
3306 : struct drm_dp_mst_atomic_payload *payload)
3307 : {
3308 : struct drm_dp_mst_port *port;
3309 : int ret;
3310 :
3311 0 : port = drm_dp_mst_topology_get_port_validated(mgr, payload->port);
3312 0 : if (!port) {
3313 0 : drm_dbg_kms(mgr->dev,
3314 : "VCPI %d for port %p not in topology, not creating a payload\n",
3315 : payload->vcpi, payload->port);
3316 0 : payload->vc_start_slot = -1;
3317 0 : return 0;
3318 : }
3319 :
3320 0 : if (mgr->payload_count == 0)
3321 0 : mgr->next_start_slot = mst_state->start_slot;
3322 :
3323 0 : payload->vc_start_slot = mgr->next_start_slot;
3324 :
3325 0 : ret = drm_dp_create_payload_step1(mgr, payload);
3326 0 : drm_dp_mst_topology_put_port(port);
3327 0 : if (ret < 0) {
3328 0 : drm_warn(mgr->dev, "Failed to create MST payload for port %p: %d\n",
3329 : payload->port, ret);
3330 0 : payload->vc_start_slot = -1;
3331 0 : return ret;
3332 : }
3333 :
3334 0 : mgr->payload_count++;
3335 0 : mgr->next_start_slot += payload->time_slots;
3336 :
3337 0 : return 0;
3338 : }
3339 : EXPORT_SYMBOL(drm_dp_add_payload_part1);
3340 :
3341 : /**
3342 : * drm_dp_remove_payload() - Remove an MST payload
3343 : * @mgr: Manager to use.
3344 : * @mst_state: The MST atomic state
3345 : * @old_payload: The payload with its old state
3346 : * @new_payload: The payload to write
3347 : *
3348 : * Removes a payload from an MST topology if it was successfully assigned a start slot. Also updates
3349 : * the starting time slots of all other payloads which would have been shifted towards the start of
3350 : * the VC table as a result. After calling this, the driver should generate ACT and payload packets.
3351 : */
3352 0 : void drm_dp_remove_payload(struct drm_dp_mst_topology_mgr *mgr,
3353 : struct drm_dp_mst_topology_state *mst_state,
3354 : const struct drm_dp_mst_atomic_payload *old_payload,
3355 : struct drm_dp_mst_atomic_payload *new_payload)
3356 : {
3357 : struct drm_dp_mst_atomic_payload *pos;
3358 0 : bool send_remove = false;
3359 :
3360 : /* We failed to make the payload, so nothing to do */
3361 0 : if (new_payload->vc_start_slot == -1)
3362 : return;
3363 :
3364 0 : mutex_lock(&mgr->lock);
3365 0 : send_remove = drm_dp_mst_port_downstream_of_branch(new_payload->port, mgr->mst_primary);
3366 0 : mutex_unlock(&mgr->lock);
3367 :
3368 0 : if (send_remove)
3369 0 : drm_dp_destroy_payload_step1(mgr, mst_state, new_payload);
3370 : else
3371 0 : drm_dbg_kms(mgr->dev, "Payload for VCPI %d not in topology, not sending remove\n",
3372 : new_payload->vcpi);
3373 :
3374 0 : list_for_each_entry(pos, &mst_state->payloads, next) {
3375 0 : if (pos != new_payload && pos->vc_start_slot > new_payload->vc_start_slot)
3376 0 : pos->vc_start_slot -= old_payload->time_slots;
3377 : }
3378 0 : new_payload->vc_start_slot = -1;
3379 :
3380 0 : mgr->payload_count--;
3381 0 : mgr->next_start_slot -= old_payload->time_slots;
3382 :
3383 0 : if (new_payload->delete)
3384 0 : drm_dp_mst_put_port_malloc(new_payload->port);
3385 : }
3386 : EXPORT_SYMBOL(drm_dp_remove_payload);
3387 :
3388 : /**
3389 : * drm_dp_add_payload_part2() - Execute payload update part 2
3390 : * @mgr: Manager to use.
3391 : * @state: The global atomic state
3392 : * @payload: The payload to update
3393 : *
3394 : * If @payload was successfully assigned a starting time slot by drm_dp_add_payload_part1(), this
3395 : * function will send the sideband messages to finish allocating this payload.
3396 : *
3397 : * Returns: 0 on success, negative error code on failure.
3398 : */
3399 0 : int drm_dp_add_payload_part2(struct drm_dp_mst_topology_mgr *mgr,
3400 : struct drm_atomic_state *state,
3401 : struct drm_dp_mst_atomic_payload *payload)
3402 : {
3403 0 : int ret = 0;
3404 :
3405 : /* Skip failed payloads */
3406 0 : if (payload->vc_start_slot == -1) {
3407 0 : drm_dbg_kms(state->dev, "Part 1 of payload creation for %s failed, skipping part 2\n",
3408 : payload->port->connector->name);
3409 0 : return -EIO;
3410 : }
3411 :
3412 0 : ret = drm_dp_create_payload_step2(mgr, payload);
3413 0 : if (ret < 0) {
3414 0 : if (!payload->delete)
3415 0 : drm_err(mgr->dev, "Step 2 of creating MST payload for %p failed: %d\n",
3416 : payload->port, ret);
3417 : else
3418 0 : drm_dbg_kms(mgr->dev, "Step 2 of removing MST payload for %p failed: %d\n",
3419 : payload->port, ret);
3420 : }
3421 :
3422 : return ret;
3423 : }
3424 : EXPORT_SYMBOL(drm_dp_add_payload_part2);
3425 :
3426 0 : static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
3427 : struct drm_dp_mst_port *port,
3428 : int offset, int size, u8 *bytes)
3429 : {
3430 0 : int ret = 0;
3431 : struct drm_dp_sideband_msg_tx *txmsg;
3432 : struct drm_dp_mst_branch *mstb;
3433 :
3434 0 : mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3435 0 : if (!mstb)
3436 : return -EINVAL;
3437 :
3438 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3439 0 : if (!txmsg) {
3440 : ret = -ENOMEM;
3441 : goto fail_put;
3442 : }
3443 :
3444 0 : build_dpcd_read(txmsg, port->port_num, offset, size);
3445 0 : txmsg->dst = port->parent;
3446 :
3447 0 : drm_dp_queue_down_tx(mgr, txmsg);
3448 :
3449 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3450 0 : if (ret < 0)
3451 : goto fail_free;
3452 :
3453 0 : if (txmsg->reply.reply_type == 1) {
3454 0 : drm_dbg_kms(mgr->dev, "mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n",
3455 : mstb, port->port_num, offset, size);
3456 0 : ret = -EIO;
3457 : goto fail_free;
3458 : }
3459 :
3460 0 : if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) {
3461 : ret = -EPROTO;
3462 : goto fail_free;
3463 : }
3464 :
3465 0 : ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes,
3466 : size);
3467 0 : memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret);
3468 :
3469 : fail_free:
3470 0 : kfree(txmsg);
3471 : fail_put:
3472 0 : drm_dp_mst_topology_put_mstb(mstb);
3473 :
3474 : return ret;
3475 : }
3476 :
3477 0 : static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
3478 : struct drm_dp_mst_port *port,
3479 : int offset, int size, u8 *bytes)
3480 : {
3481 : int ret;
3482 : struct drm_dp_sideband_msg_tx *txmsg;
3483 : struct drm_dp_mst_branch *mstb;
3484 :
3485 0 : mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3486 0 : if (!mstb)
3487 : return -EINVAL;
3488 :
3489 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3490 0 : if (!txmsg) {
3491 : ret = -ENOMEM;
3492 : goto fail_put;
3493 : }
3494 :
3495 0 : build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
3496 0 : txmsg->dst = mstb;
3497 :
3498 0 : drm_dp_queue_down_tx(mgr, txmsg);
3499 :
3500 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3501 0 : if (ret > 0) {
3502 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3503 : ret = -EIO;
3504 : else
3505 0 : ret = size;
3506 : }
3507 :
3508 0 : kfree(txmsg);
3509 : fail_put:
3510 0 : drm_dp_mst_topology_put_mstb(mstb);
3511 : return ret;
3512 : }
3513 :
3514 : static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
3515 : {
3516 : struct drm_dp_sideband_msg_reply_body reply;
3517 :
3518 0 : reply.reply_type = DP_SIDEBAND_REPLY_ACK;
3519 0 : reply.req_type = req_type;
3520 0 : drm_dp_encode_sideband_reply(&reply, msg);
3521 : return 0;
3522 : }
3523 :
3524 0 : static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
3525 : struct drm_dp_mst_branch *mstb,
3526 : int req_type, bool broadcast)
3527 : {
3528 : struct drm_dp_sideband_msg_tx *txmsg;
3529 :
3530 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3531 0 : if (!txmsg)
3532 : return -ENOMEM;
3533 :
3534 0 : txmsg->dst = mstb;
3535 0 : drm_dp_encode_up_ack_reply(txmsg, req_type);
3536 :
3537 0 : mutex_lock(&mgr->qlock);
3538 : /* construct a chunk from the first msg in the tx_msg queue */
3539 0 : process_single_tx_qlock(mgr, txmsg, true);
3540 0 : mutex_unlock(&mgr->qlock);
3541 :
3542 0 : kfree(txmsg);
3543 0 : return 0;
3544 : }
3545 :
3546 : /**
3547 : * drm_dp_get_vc_payload_bw - get the VC payload BW for an MST link
3548 : * @mgr: The &drm_dp_mst_topology_mgr to use
3549 : * @link_rate: link rate in 10kbits/s units
3550 : * @link_lane_count: lane count
3551 : *
3552 : * Calculate the total bandwidth of a MultiStream Transport link. The returned
3553 : * value is in units of PBNs/(timeslots/1 MTP). This value can be used to
3554 : * convert the number of PBNs required for a given stream to the number of
3555 : * timeslots this stream requires in each MTP.
3556 : */
3557 0 : int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr,
3558 : int link_rate, int link_lane_count)
3559 : {
3560 0 : if (link_rate == 0 || link_lane_count == 0)
3561 0 : drm_dbg_kms(mgr->dev, "invalid link rate/lane count: (%d / %d)\n",
3562 : link_rate, link_lane_count);
3563 :
3564 : /* See DP v2.0 2.6.4.2, VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */
3565 0 : return link_rate * link_lane_count / 54000;
3566 : }
3567 : EXPORT_SYMBOL(drm_dp_get_vc_payload_bw);
3568 :
3569 : /**
3570 : * drm_dp_read_mst_cap() - check whether or not a sink supports MST
3571 : * @aux: The DP AUX channel to use
3572 : * @dpcd: A cached copy of the DPCD capabilities for this sink
3573 : *
3574 : * Returns: %True if the sink supports MST, %false otherwise
3575 : */
3576 0 : bool drm_dp_read_mst_cap(struct drm_dp_aux *aux,
3577 : const u8 dpcd[DP_RECEIVER_CAP_SIZE])
3578 : {
3579 : u8 mstm_cap;
3580 :
3581 0 : if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_12)
3582 : return false;
3583 :
3584 0 : if (drm_dp_dpcd_readb(aux, DP_MSTM_CAP, &mstm_cap) != 1)
3585 : return false;
3586 :
3587 0 : return mstm_cap & DP_MST_CAP;
3588 : }
3589 : EXPORT_SYMBOL(drm_dp_read_mst_cap);
3590 :
3591 : /**
3592 : * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
3593 : * @mgr: manager to set state for
3594 : * @mst_state: true to enable MST on this connector - false to disable.
3595 : *
3596 : * This is called by the driver when it detects an MST capable device plugged
3597 : * into a DP MST capable port, or when a DP MST capable device is unplugged.
3598 : */
3599 0 : int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
3600 : {
3601 0 : int ret = 0;
3602 0 : struct drm_dp_mst_branch *mstb = NULL;
3603 :
3604 0 : mutex_lock(&mgr->lock);
3605 0 : if (mst_state == mgr->mst_state)
3606 : goto out_unlock;
3607 :
3608 0 : mgr->mst_state = mst_state;
3609 : /* set the device into MST mode */
3610 0 : if (mst_state) {
3611 0 : WARN_ON(mgr->mst_primary);
3612 :
3613 : /* get dpcd info */
3614 0 : ret = drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd);
3615 0 : if (ret < 0) {
3616 0 : drm_dbg_kms(mgr->dev, "%s: failed to read DPCD, ret %d\n",
3617 : mgr->aux->name, ret);
3618 0 : goto out_unlock;
3619 : }
3620 :
3621 : /* add initial branch device at LCT 1 */
3622 0 : mstb = drm_dp_add_mst_branch_device(1, NULL);
3623 0 : if (mstb == NULL) {
3624 : ret = -ENOMEM;
3625 : goto out_unlock;
3626 : }
3627 0 : mstb->mgr = mgr;
3628 :
3629 : /* give this the main reference */
3630 0 : mgr->mst_primary = mstb;
3631 0 : drm_dp_mst_topology_get_mstb(mgr->mst_primary);
3632 :
3633 0 : ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3634 : DP_MST_EN |
3635 : DP_UP_REQ_EN |
3636 : DP_UPSTREAM_IS_SRC);
3637 0 : if (ret < 0)
3638 : goto out_unlock;
3639 :
3640 : /* Write reset payload */
3641 0 : drm_dp_dpcd_write_payload(mgr, 0, 0, 0x3f);
3642 :
3643 0 : queue_work(system_long_wq, &mgr->work);
3644 :
3645 0 : ret = 0;
3646 : } else {
3647 : /* disable MST on the device */
3648 0 : mstb = mgr->mst_primary;
3649 0 : mgr->mst_primary = NULL;
3650 : /* this can fail if the device is gone */
3651 0 : drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
3652 0 : ret = 0;
3653 0 : mgr->payload_id_table_cleared = false;
3654 :
3655 0 : memset(&mgr->down_rep_recv, 0, sizeof(mgr->down_rep_recv));
3656 0 : memset(&mgr->up_req_recv, 0, sizeof(mgr->up_req_recv));
3657 : }
3658 :
3659 : out_unlock:
3660 0 : mutex_unlock(&mgr->lock);
3661 0 : if (mstb)
3662 0 : drm_dp_mst_topology_put_mstb(mstb);
3663 0 : return ret;
3664 :
3665 : }
3666 : EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
3667 :
3668 : static void
3669 0 : drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
3670 : {
3671 : struct drm_dp_mst_port *port;
3672 :
3673 : /* The link address will need to be re-sent on resume */
3674 0 : mstb->link_address_sent = false;
3675 :
3676 0 : list_for_each_entry(port, &mstb->ports, next)
3677 0 : if (port->mstb)
3678 0 : drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb);
3679 0 : }
3680 :
3681 : /**
3682 : * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
3683 : * @mgr: manager to suspend
3684 : *
3685 : * This function tells the MST device that we can't handle UP messages
3686 : * anymore. This should stop it from sending any since we are suspended.
3687 : */
3688 0 : void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
3689 : {
3690 0 : mutex_lock(&mgr->lock);
3691 0 : drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3692 : DP_MST_EN | DP_UPSTREAM_IS_SRC);
3693 0 : mutex_unlock(&mgr->lock);
3694 0 : flush_work(&mgr->up_req_work);
3695 0 : flush_work(&mgr->work);
3696 0 : flush_work(&mgr->delayed_destroy_work);
3697 :
3698 0 : mutex_lock(&mgr->lock);
3699 0 : if (mgr->mst_state && mgr->mst_primary)
3700 0 : drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary);
3701 0 : mutex_unlock(&mgr->lock);
3702 0 : }
3703 : EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
3704 :
3705 : /**
3706 : * drm_dp_mst_topology_mgr_resume() - resume the MST manager
3707 : * @mgr: manager to resume
3708 : * @sync: whether or not to perform topology reprobing synchronously
3709 : *
3710 : * This will fetch DPCD and see if the device is still there,
3711 : * if it is, it will rewrite the MSTM control bits, and return.
3712 : *
3713 : * If the device fails this returns -1, and the driver should do
3714 : * a full MST reprobe, in case we were undocked.
3715 : *
3716 : * During system resume (where it is assumed that the driver will be calling
3717 : * drm_atomic_helper_resume()) this function should be called beforehand with
3718 : * @sync set to true. In contexts like runtime resume where the driver is not
3719 : * expected to be calling drm_atomic_helper_resume(), this function should be
3720 : * called with @sync set to false in order to avoid deadlocking.
3721 : *
3722 : * Returns: -1 if the MST topology was removed while we were suspended, 0
3723 : * otherwise.
3724 : */
3725 0 : int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
3726 : bool sync)
3727 : {
3728 : int ret;
3729 : u8 guid[16];
3730 :
3731 0 : mutex_lock(&mgr->lock);
3732 0 : if (!mgr->mst_primary)
3733 : goto out_fail;
3734 :
3735 0 : if (drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd) < 0) {
3736 0 : drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n");
3737 0 : goto out_fail;
3738 : }
3739 :
3740 0 : ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3741 : DP_MST_EN |
3742 : DP_UP_REQ_EN |
3743 : DP_UPSTREAM_IS_SRC);
3744 0 : if (ret < 0) {
3745 0 : drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n");
3746 0 : goto out_fail;
3747 : }
3748 :
3749 : /* Some hubs forget their guids after they resume */
3750 0 : ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
3751 0 : if (ret != 16) {
3752 0 : drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n");
3753 0 : goto out_fail;
3754 : }
3755 :
3756 0 : ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid);
3757 0 : if (ret) {
3758 0 : drm_dbg_kms(mgr->dev, "check mstb failed - undocked during suspend?\n");
3759 0 : goto out_fail;
3760 : }
3761 :
3762 : /*
3763 : * For the final step of resuming the topology, we need to bring the
3764 : * state of our in-memory topology back into sync with reality. So,
3765 : * restart the probing process as if we're probing a new hub
3766 : */
3767 0 : queue_work(system_long_wq, &mgr->work);
3768 0 : mutex_unlock(&mgr->lock);
3769 :
3770 0 : if (sync) {
3771 0 : drm_dbg_kms(mgr->dev,
3772 : "Waiting for link probe work to finish re-syncing topology...\n");
3773 0 : flush_work(&mgr->work);
3774 : }
3775 :
3776 : return 0;
3777 :
3778 : out_fail:
3779 0 : mutex_unlock(&mgr->lock);
3780 0 : return -1;
3781 : }
3782 : EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
3783 :
3784 : static bool
3785 0 : drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up,
3786 : struct drm_dp_mst_branch **mstb)
3787 : {
3788 : int len;
3789 : u8 replyblock[32];
3790 : int replylen, curreply;
3791 : int ret;
3792 : u8 hdrlen;
3793 : struct drm_dp_sideband_msg_hdr hdr;
3794 0 : struct drm_dp_sideband_msg_rx *msg =
3795 0 : up ? &mgr->up_req_recv : &mgr->down_rep_recv;
3796 0 : int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE :
3797 : DP_SIDEBAND_MSG_DOWN_REP_BASE;
3798 :
3799 0 : if (!up)
3800 0 : *mstb = NULL;
3801 :
3802 0 : len = min(mgr->max_dpcd_transaction_bytes, 16);
3803 0 : ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len);
3804 0 : if (ret != len) {
3805 0 : drm_dbg_kms(mgr->dev, "failed to read DPCD down rep %d %d\n", len, ret);
3806 0 : return false;
3807 : }
3808 :
3809 0 : ret = drm_dp_decode_sideband_msg_hdr(mgr, &hdr, replyblock, len, &hdrlen);
3810 0 : if (ret == false) {
3811 0 : print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16,
3812 : 1, replyblock, len, false);
3813 0 : drm_dbg_kms(mgr->dev, "ERROR: failed header\n");
3814 0 : return false;
3815 : }
3816 :
3817 0 : if (!up) {
3818 : /* Caller is responsible for giving back this reference */
3819 0 : *mstb = drm_dp_get_mst_branch_device(mgr, hdr.lct, hdr.rad);
3820 0 : if (!*mstb) {
3821 0 : drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr.lct);
3822 0 : return false;
3823 : }
3824 : }
3825 :
3826 0 : if (!drm_dp_sideband_msg_set_header(msg, &hdr, hdrlen)) {
3827 0 : drm_dbg_kms(mgr->dev, "sideband msg set header failed %d\n", replyblock[0]);
3828 0 : return false;
3829 : }
3830 :
3831 0 : replylen = min(msg->curchunk_len, (u8)(len - hdrlen));
3832 0 : ret = drm_dp_sideband_append_payload(msg, replyblock + hdrlen, replylen);
3833 0 : if (!ret) {
3834 0 : drm_dbg_kms(mgr->dev, "sideband msg build failed %d\n", replyblock[0]);
3835 0 : return false;
3836 : }
3837 :
3838 0 : replylen = msg->curchunk_len + msg->curchunk_hdrlen - len;
3839 0 : curreply = len;
3840 0 : while (replylen > 0) {
3841 0 : len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
3842 0 : ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
3843 : replyblock, len);
3844 0 : if (ret != len) {
3845 0 : drm_dbg_kms(mgr->dev, "failed to read a chunk (len %d, ret %d)\n",
3846 : len, ret);
3847 0 : return false;
3848 : }
3849 :
3850 0 : ret = drm_dp_sideband_append_payload(msg, replyblock, len);
3851 0 : if (!ret) {
3852 0 : drm_dbg_kms(mgr->dev, "failed to build sideband msg\n");
3853 0 : return false;
3854 : }
3855 :
3856 0 : curreply += len;
3857 0 : replylen -= len;
3858 : }
3859 : return true;
3860 : }
3861 :
3862 0 : static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
3863 : {
3864 : struct drm_dp_sideband_msg_tx *txmsg;
3865 0 : struct drm_dp_mst_branch *mstb = NULL;
3866 0 : struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv;
3867 :
3868 0 : if (!drm_dp_get_one_sb_msg(mgr, false, &mstb))
3869 : goto out_clear_reply;
3870 :
3871 : /* Multi-packet message transmission, don't clear the reply */
3872 0 : if (!msg->have_eomt)
3873 : goto out;
3874 :
3875 : /* find the message */
3876 0 : mutex_lock(&mgr->qlock);
3877 0 : txmsg = list_first_entry_or_null(&mgr->tx_msg_downq,
3878 : struct drm_dp_sideband_msg_tx, next);
3879 0 : mutex_unlock(&mgr->qlock);
3880 :
3881 : /* Were we actually expecting a response, and from this mstb? */
3882 0 : if (!txmsg || txmsg->dst != mstb) {
3883 : struct drm_dp_sideband_msg_hdr *hdr;
3884 :
3885 0 : hdr = &msg->initial_hdr;
3886 0 : drm_dbg_kms(mgr->dev, "Got MST reply with no msg %p %d %d %02x %02x\n",
3887 : mstb, hdr->seqno, hdr->lct, hdr->rad[0], msg->msg[0]);
3888 0 : goto out_clear_reply;
3889 : }
3890 :
3891 0 : drm_dp_sideband_parse_reply(mgr, msg, &txmsg->reply);
3892 :
3893 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3894 0 : drm_dbg_kms(mgr->dev,
3895 : "Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
3896 : txmsg->reply.req_type,
3897 : drm_dp_mst_req_type_str(txmsg->reply.req_type),
3898 : txmsg->reply.u.nak.reason,
3899 : drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason),
3900 : txmsg->reply.u.nak.nak_data);
3901 : }
3902 :
3903 0 : memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
3904 0 : drm_dp_mst_topology_put_mstb(mstb);
3905 :
3906 0 : mutex_lock(&mgr->qlock);
3907 0 : txmsg->state = DRM_DP_SIDEBAND_TX_RX;
3908 0 : list_del(&txmsg->next);
3909 0 : mutex_unlock(&mgr->qlock);
3910 :
3911 0 : wake_up_all(&mgr->tx_waitq);
3912 :
3913 0 : return 0;
3914 :
3915 : out_clear_reply:
3916 0 : memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
3917 : out:
3918 0 : if (mstb)
3919 0 : drm_dp_mst_topology_put_mstb(mstb);
3920 :
3921 : return 0;
3922 : }
3923 :
3924 : static inline bool
3925 0 : drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
3926 : struct drm_dp_pending_up_req *up_req)
3927 : {
3928 0 : struct drm_dp_mst_branch *mstb = NULL;
3929 0 : struct drm_dp_sideband_msg_req_body *msg = &up_req->msg;
3930 0 : struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr;
3931 0 : bool hotplug = false, dowork = false;
3932 :
3933 0 : if (hdr->broadcast) {
3934 0 : const u8 *guid = NULL;
3935 :
3936 0 : if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY)
3937 0 : guid = msg->u.conn_stat.guid;
3938 0 : else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
3939 0 : guid = msg->u.resource_stat.guid;
3940 :
3941 0 : if (guid)
3942 0 : mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
3943 : } else {
3944 0 : mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
3945 : }
3946 :
3947 0 : if (!mstb) {
3948 0 : drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr->lct);
3949 0 : return false;
3950 : }
3951 :
3952 : /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */
3953 0 : if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) {
3954 0 : dowork = drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat);
3955 0 : hotplug = true;
3956 : }
3957 :
3958 0 : drm_dp_mst_topology_put_mstb(mstb);
3959 :
3960 0 : if (dowork)
3961 0 : queue_work(system_long_wq, &mgr->work);
3962 : return hotplug;
3963 : }
3964 :
3965 0 : static void drm_dp_mst_up_req_work(struct work_struct *work)
3966 : {
3967 0 : struct drm_dp_mst_topology_mgr *mgr =
3968 0 : container_of(work, struct drm_dp_mst_topology_mgr,
3969 : up_req_work);
3970 : struct drm_dp_pending_up_req *up_req;
3971 0 : bool send_hotplug = false;
3972 :
3973 0 : mutex_lock(&mgr->probe_lock);
3974 : while (true) {
3975 0 : mutex_lock(&mgr->up_req_lock);
3976 0 : up_req = list_first_entry_or_null(&mgr->up_req_list,
3977 : struct drm_dp_pending_up_req,
3978 : next);
3979 0 : if (up_req)
3980 0 : list_del(&up_req->next);
3981 0 : mutex_unlock(&mgr->up_req_lock);
3982 :
3983 0 : if (!up_req)
3984 : break;
3985 :
3986 0 : send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req);
3987 0 : kfree(up_req);
3988 : }
3989 0 : mutex_unlock(&mgr->probe_lock);
3990 :
3991 0 : if (send_hotplug)
3992 0 : drm_kms_helper_hotplug_event(mgr->dev);
3993 0 : }
3994 :
3995 0 : static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
3996 : {
3997 : struct drm_dp_pending_up_req *up_req;
3998 :
3999 0 : if (!drm_dp_get_one_sb_msg(mgr, true, NULL))
4000 : goto out;
4001 :
4002 0 : if (!mgr->up_req_recv.have_eomt)
4003 : return 0;
4004 :
4005 0 : up_req = kzalloc(sizeof(*up_req), GFP_KERNEL);
4006 0 : if (!up_req)
4007 : return -ENOMEM;
4008 :
4009 0 : INIT_LIST_HEAD(&up_req->next);
4010 :
4011 0 : drm_dp_sideband_parse_req(mgr, &mgr->up_req_recv, &up_req->msg);
4012 :
4013 0 : if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY &&
4014 : up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) {
4015 0 : drm_dbg_kms(mgr->dev, "Received unknown up req type, ignoring: %x\n",
4016 : up_req->msg.req_type);
4017 0 : kfree(up_req);
4018 0 : goto out;
4019 : }
4020 :
4021 0 : drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type,
4022 : false);
4023 :
4024 0 : if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
4025 0 : const struct drm_dp_connection_status_notify *conn_stat =
4026 : &up_req->msg.u.conn_stat;
4027 :
4028 0 : drm_dbg_kms(mgr->dev, "Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
4029 : conn_stat->port_number,
4030 : conn_stat->legacy_device_plug_status,
4031 : conn_stat->displayport_device_plug_status,
4032 : conn_stat->message_capability_status,
4033 : conn_stat->input_port,
4034 : conn_stat->peer_device_type);
4035 0 : } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
4036 0 : const struct drm_dp_resource_status_notify *res_stat =
4037 : &up_req->msg.u.resource_stat;
4038 :
4039 0 : drm_dbg_kms(mgr->dev, "Got RSN: pn: %d avail_pbn %d\n",
4040 : res_stat->port_number,
4041 : res_stat->available_pbn);
4042 : }
4043 :
4044 0 : up_req->hdr = mgr->up_req_recv.initial_hdr;
4045 0 : mutex_lock(&mgr->up_req_lock);
4046 0 : list_add_tail(&up_req->next, &mgr->up_req_list);
4047 0 : mutex_unlock(&mgr->up_req_lock);
4048 0 : queue_work(system_long_wq, &mgr->up_req_work);
4049 :
4050 : out:
4051 0 : memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
4052 0 : return 0;
4053 : }
4054 :
4055 : /**
4056 : * drm_dp_mst_hpd_irq_handle_event() - MST hotplug IRQ handle MST event
4057 : * @mgr: manager to notify irq for.
4058 : * @esi: 4 bytes from SINK_COUNT_ESI
4059 : * @ack: 4 bytes used to ack events starting from SINK_COUNT_ESI
4060 : * @handled: whether the hpd interrupt was consumed or not
4061 : *
4062 : * This should be called from the driver when it detects a HPD IRQ,
4063 : * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
4064 : * topology manager will process the sideband messages received
4065 : * as indicated in the DEVICE_SERVICE_IRQ_VECTOR_ESI0 and set the
4066 : * corresponding flags that Driver has to ack the DP receiver later.
4067 : *
4068 : * Note that driver shall also call
4069 : * drm_dp_mst_hpd_irq_send_new_request() if the 'handled' is set
4070 : * after calling this function, to try to kick off a new request in
4071 : * the queue if the previous message transaction is completed.
4072 : *
4073 : * See also:
4074 : * drm_dp_mst_hpd_irq_send_new_request()
4075 : */
4076 0 : int drm_dp_mst_hpd_irq_handle_event(struct drm_dp_mst_topology_mgr *mgr, const u8 *esi,
4077 : u8 *ack, bool *handled)
4078 : {
4079 0 : int ret = 0;
4080 : int sc;
4081 0 : *handled = false;
4082 0 : sc = DP_GET_SINK_COUNT(esi[0]);
4083 :
4084 0 : if (sc != mgr->sink_count) {
4085 0 : mgr->sink_count = sc;
4086 0 : *handled = true;
4087 : }
4088 :
4089 0 : if (esi[1] & DP_DOWN_REP_MSG_RDY) {
4090 0 : ret = drm_dp_mst_handle_down_rep(mgr);
4091 0 : *handled = true;
4092 0 : ack[1] |= DP_DOWN_REP_MSG_RDY;
4093 : }
4094 :
4095 0 : if (esi[1] & DP_UP_REQ_MSG_RDY) {
4096 0 : ret |= drm_dp_mst_handle_up_req(mgr);
4097 0 : *handled = true;
4098 0 : ack[1] |= DP_UP_REQ_MSG_RDY;
4099 : }
4100 :
4101 0 : return ret;
4102 : }
4103 : EXPORT_SYMBOL(drm_dp_mst_hpd_irq_handle_event);
4104 :
4105 : /**
4106 : * drm_dp_mst_hpd_irq_send_new_request() - MST hotplug IRQ kick off new request
4107 : * @mgr: manager to notify irq for.
4108 : *
4109 : * This should be called from the driver when mst irq event is handled
4110 : * and acked. Note that new down request should only be sent when
4111 : * previous message transaction is completed. Source is not supposed to generate
4112 : * interleaved message transactions.
4113 : */
4114 0 : void drm_dp_mst_hpd_irq_send_new_request(struct drm_dp_mst_topology_mgr *mgr)
4115 : {
4116 : struct drm_dp_sideband_msg_tx *txmsg;
4117 0 : bool kick = true;
4118 :
4119 0 : mutex_lock(&mgr->qlock);
4120 0 : txmsg = list_first_entry_or_null(&mgr->tx_msg_downq,
4121 : struct drm_dp_sideband_msg_tx, next);
4122 : /* If last transaction is not completed yet*/
4123 0 : if (!txmsg ||
4124 0 : txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
4125 : txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
4126 0 : kick = false;
4127 0 : mutex_unlock(&mgr->qlock);
4128 :
4129 0 : if (kick)
4130 : drm_dp_mst_kick_tx(mgr);
4131 0 : }
4132 : EXPORT_SYMBOL(drm_dp_mst_hpd_irq_send_new_request);
4133 : /**
4134 : * drm_dp_mst_detect_port() - get connection status for an MST port
4135 : * @connector: DRM connector for this port
4136 : * @ctx: The acquisition context to use for grabbing locks
4137 : * @mgr: manager for this port
4138 : * @port: pointer to a port
4139 : *
4140 : * This returns the current connection state for a port.
4141 : */
4142 : int
4143 0 : drm_dp_mst_detect_port(struct drm_connector *connector,
4144 : struct drm_modeset_acquire_ctx *ctx,
4145 : struct drm_dp_mst_topology_mgr *mgr,
4146 : struct drm_dp_mst_port *port)
4147 : {
4148 : int ret;
4149 :
4150 : /* we need to search for the port in the mgr in case it's gone */
4151 0 : port = drm_dp_mst_topology_get_port_validated(mgr, port);
4152 0 : if (!port)
4153 : return connector_status_disconnected;
4154 :
4155 0 : ret = drm_modeset_lock(&mgr->base.lock, ctx);
4156 0 : if (ret)
4157 : goto out;
4158 :
4159 0 : ret = connector_status_disconnected;
4160 :
4161 0 : if (!port->ddps)
4162 : goto out;
4163 :
4164 0 : switch (port->pdt) {
4165 : case DP_PEER_DEVICE_NONE:
4166 : break;
4167 : case DP_PEER_DEVICE_MST_BRANCHING:
4168 0 : if (!port->mcs)
4169 0 : ret = connector_status_connected;
4170 : break;
4171 :
4172 : case DP_PEER_DEVICE_SST_SINK:
4173 0 : ret = connector_status_connected;
4174 : /* for logical ports - cache the EDID */
4175 0 : if (port->port_num >= DP_MST_LOGICAL_PORT_0 && !port->cached_edid)
4176 0 : port->cached_edid = drm_edid_read_ddc(connector, &port->aux.ddc);
4177 : break;
4178 : case DP_PEER_DEVICE_DP_LEGACY_CONV:
4179 0 : if (port->ldps)
4180 0 : ret = connector_status_connected;
4181 : break;
4182 : }
4183 : out:
4184 0 : drm_dp_mst_topology_put_port(port);
4185 0 : return ret;
4186 : }
4187 : EXPORT_SYMBOL(drm_dp_mst_detect_port);
4188 :
4189 : /**
4190 : * drm_dp_mst_edid_read() - get EDID for an MST port
4191 : * @connector: toplevel connector to get EDID for
4192 : * @mgr: manager for this port
4193 : * @port: unverified pointer to a port.
4194 : *
4195 : * This returns an EDID for the port connected to a connector,
4196 : * It validates the pointer still exists so the caller doesn't require a
4197 : * reference.
4198 : */
4199 0 : const struct drm_edid *drm_dp_mst_edid_read(struct drm_connector *connector,
4200 : struct drm_dp_mst_topology_mgr *mgr,
4201 : struct drm_dp_mst_port *port)
4202 : {
4203 : const struct drm_edid *drm_edid;
4204 :
4205 : /* we need to search for the port in the mgr in case it's gone */
4206 0 : port = drm_dp_mst_topology_get_port_validated(mgr, port);
4207 0 : if (!port)
4208 : return NULL;
4209 :
4210 0 : if (port->cached_edid)
4211 0 : drm_edid = drm_edid_dup(port->cached_edid);
4212 : else
4213 0 : drm_edid = drm_edid_read_ddc(connector, &port->aux.ddc);
4214 :
4215 0 : drm_dp_mst_topology_put_port(port);
4216 :
4217 0 : return drm_edid;
4218 : }
4219 : EXPORT_SYMBOL(drm_dp_mst_edid_read);
4220 :
4221 : /**
4222 : * drm_dp_mst_get_edid() - get EDID for an MST port
4223 : * @connector: toplevel connector to get EDID for
4224 : * @mgr: manager for this port
4225 : * @port: unverified pointer to a port.
4226 : *
4227 : * This function is deprecated; please use drm_dp_mst_edid_read() instead.
4228 : *
4229 : * This returns an EDID for the port connected to a connector,
4230 : * It validates the pointer still exists so the caller doesn't require a
4231 : * reference.
4232 : */
4233 0 : struct edid *drm_dp_mst_get_edid(struct drm_connector *connector,
4234 : struct drm_dp_mst_topology_mgr *mgr,
4235 : struct drm_dp_mst_port *port)
4236 : {
4237 : const struct drm_edid *drm_edid;
4238 : struct edid *edid;
4239 :
4240 0 : drm_edid = drm_dp_mst_edid_read(connector, mgr, port);
4241 :
4242 0 : edid = drm_edid_duplicate(drm_edid_raw(drm_edid));
4243 :
4244 0 : drm_edid_free(drm_edid);
4245 :
4246 0 : return edid;
4247 : }
4248 : EXPORT_SYMBOL(drm_dp_mst_get_edid);
4249 :
4250 : /**
4251 : * drm_dp_atomic_find_time_slots() - Find and add time slots to the state
4252 : * @state: global atomic state
4253 : * @mgr: MST topology manager for the port
4254 : * @port: port to find time slots for
4255 : * @pbn: bandwidth required for the mode in PBN
4256 : *
4257 : * Allocates time slots to @port, replacing any previous time slot allocations it may
4258 : * have had. Any atomic drivers which support MST must call this function in
4259 : * their &drm_encoder_helper_funcs.atomic_check() callback unconditionally to
4260 : * change the current time slot allocation for the new state, and ensure the MST
4261 : * atomic state is added whenever the state of payloads in the topology changes.
4262 : *
4263 : * Allocations set by this function are not checked against the bandwidth
4264 : * restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
4265 : *
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_release_time_slots() in the same atomic check phase.
4269 : *
4270 : * See also:
4271 : * drm_dp_atomic_release_time_slots()
4272 : * drm_dp_mst_atomic_check()
4273 : *
4274 : * Returns:
4275 : * Total slots in the atomic state assigned for this port, or a negative error
4276 : * code if the port no longer exists
4277 : */
4278 0 : int drm_dp_atomic_find_time_slots(struct drm_atomic_state *state,
4279 : struct drm_dp_mst_topology_mgr *mgr,
4280 : struct drm_dp_mst_port *port, int pbn)
4281 : {
4282 : struct drm_dp_mst_topology_state *topology_state;
4283 0 : struct drm_dp_mst_atomic_payload *payload = NULL;
4284 : struct drm_connector_state *conn_state;
4285 0 : int prev_slots = 0, prev_bw = 0, req_slots;
4286 :
4287 0 : topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4288 0 : if (IS_ERR(topology_state))
4289 0 : return PTR_ERR(topology_state);
4290 :
4291 0 : conn_state = drm_atomic_get_new_connector_state(state, port->connector);
4292 0 : topology_state->pending_crtc_mask |= drm_crtc_mask(conn_state->crtc);
4293 :
4294 : /* Find the current allocation for this port, if any */
4295 0 : payload = drm_atomic_get_mst_payload_state(topology_state, port);
4296 0 : if (payload) {
4297 0 : prev_slots = payload->time_slots;
4298 0 : prev_bw = payload->pbn;
4299 :
4300 : /*
4301 : * This should never happen, unless the driver tries
4302 : * releasing and allocating the same timeslot allocation,
4303 : * which is an error
4304 : */
4305 0 : if (drm_WARN_ON(mgr->dev, payload->delete)) {
4306 0 : drm_err(mgr->dev,
4307 : "cannot allocate and release time slots on [MST PORT:%p] in the same state\n",
4308 : port);
4309 0 : return -EINVAL;
4310 : }
4311 : }
4312 :
4313 0 : req_slots = DIV_ROUND_UP(pbn, topology_state->pbn_div);
4314 :
4315 0 : drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] TU %d -> %d\n",
4316 : port->connector->base.id, port->connector->name,
4317 : port, prev_slots, req_slots);
4318 0 : drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n",
4319 : port->connector->base.id, port->connector->name,
4320 : port, prev_bw, pbn);
4321 :
4322 : /* Add the new allocation to the state, note the VCPI isn't assigned until the end */
4323 0 : if (!payload) {
4324 0 : payload = kzalloc(sizeof(*payload), GFP_KERNEL);
4325 0 : if (!payload)
4326 : return -ENOMEM;
4327 :
4328 0 : drm_dp_mst_get_port_malloc(port);
4329 0 : payload->port = port;
4330 0 : payload->vc_start_slot = -1;
4331 0 : list_add(&payload->next, &topology_state->payloads);
4332 : }
4333 0 : payload->time_slots = req_slots;
4334 0 : payload->pbn = pbn;
4335 :
4336 0 : return req_slots;
4337 : }
4338 : EXPORT_SYMBOL(drm_dp_atomic_find_time_slots);
4339 :
4340 : /**
4341 : * drm_dp_atomic_release_time_slots() - Release allocated time slots
4342 : * @state: global atomic state
4343 : * @mgr: MST topology manager for the port
4344 : * @port: The port to release the time slots from
4345 : *
4346 : * Releases any time slots that have been allocated to a port in the atomic
4347 : * state. Any atomic drivers which support MST must call this function
4348 : * unconditionally in their &drm_connector_helper_funcs.atomic_check() callback.
4349 : * This helper will check whether time slots would be released by the new state and
4350 : * respond accordingly, along with ensuring the MST state is always added to the
4351 : * atomic state whenever a new state would modify the state of payloads on the
4352 : * topology.
4353 : *
4354 : * It is OK to call this even if @port has been removed from the system.
4355 : * Additionally, it is OK to call this function multiple times on the same
4356 : * @port as needed. It is not OK however, to call this function and
4357 : * drm_dp_atomic_find_time_slots() on the same @port in a single atomic check
4358 : * phase.
4359 : *
4360 : * See also:
4361 : * drm_dp_atomic_find_time_slots()
4362 : * drm_dp_mst_atomic_check()
4363 : *
4364 : * Returns:
4365 : * 0 on success, negative error code otherwise
4366 : */
4367 0 : int drm_dp_atomic_release_time_slots(struct drm_atomic_state *state,
4368 : struct drm_dp_mst_topology_mgr *mgr,
4369 : struct drm_dp_mst_port *port)
4370 : {
4371 : struct drm_dp_mst_topology_state *topology_state;
4372 : struct drm_dp_mst_atomic_payload *payload;
4373 : struct drm_connector_state *old_conn_state, *new_conn_state;
4374 0 : bool update_payload = true;
4375 :
4376 0 : old_conn_state = drm_atomic_get_old_connector_state(state, port->connector);
4377 0 : if (!old_conn_state->crtc)
4378 : return 0;
4379 :
4380 : /* If the CRTC isn't disabled by this state, don't release it's payload */
4381 0 : new_conn_state = drm_atomic_get_new_connector_state(state, port->connector);
4382 0 : if (new_conn_state->crtc) {
4383 0 : struct drm_crtc_state *crtc_state =
4384 : drm_atomic_get_new_crtc_state(state, new_conn_state->crtc);
4385 :
4386 : /* No modeset means no payload changes, so it's safe to not pull in the MST state */
4387 0 : if (!crtc_state || !drm_atomic_crtc_needs_modeset(crtc_state))
4388 : return 0;
4389 :
4390 0 : if (!crtc_state->mode_changed && !crtc_state->connectors_changed)
4391 0 : update_payload = false;
4392 : }
4393 :
4394 0 : topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4395 0 : if (IS_ERR(topology_state))
4396 0 : return PTR_ERR(topology_state);
4397 :
4398 0 : topology_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc);
4399 0 : if (!update_payload)
4400 : return 0;
4401 :
4402 0 : payload = drm_atomic_get_mst_payload_state(topology_state, port);
4403 0 : if (WARN_ON(!payload)) {
4404 0 : drm_err(mgr->dev, "No payload for [MST PORT:%p] found in mst state %p\n",
4405 : port, &topology_state->base);
4406 0 : return -EINVAL;
4407 : }
4408 :
4409 0 : if (new_conn_state->crtc)
4410 : return 0;
4411 :
4412 0 : drm_dbg_atomic(mgr->dev, "[MST PORT:%p] TU %d -> 0\n", port, payload->time_slots);
4413 0 : if (!payload->delete) {
4414 0 : payload->pbn = 0;
4415 0 : payload->delete = true;
4416 0 : topology_state->payload_mask &= ~BIT(payload->vcpi - 1);
4417 : }
4418 :
4419 : return 0;
4420 : }
4421 : EXPORT_SYMBOL(drm_dp_atomic_release_time_slots);
4422 :
4423 : /**
4424 : * drm_dp_mst_atomic_setup_commit() - setup_commit hook for MST helpers
4425 : * @state: global atomic state
4426 : *
4427 : * This function saves all of the &drm_crtc_commit structs in an atomic state that touch any CRTCs
4428 : * currently assigned to an MST topology. Drivers must call this hook from their
4429 : * &drm_mode_config_helper_funcs.atomic_commit_setup hook.
4430 : *
4431 : * Returns:
4432 : * 0 if all CRTC commits were retrieved successfully, negative error code otherwise
4433 : */
4434 0 : int drm_dp_mst_atomic_setup_commit(struct drm_atomic_state *state)
4435 : {
4436 : struct drm_dp_mst_topology_mgr *mgr;
4437 : struct drm_dp_mst_topology_state *mst_state;
4438 : struct drm_crtc *crtc;
4439 : struct drm_crtc_state *crtc_state;
4440 : int i, j, commit_idx, num_commit_deps;
4441 :
4442 0 : for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
4443 0 : if (!mst_state->pending_crtc_mask)
4444 0 : continue;
4445 :
4446 0 : num_commit_deps = hweight32(mst_state->pending_crtc_mask);
4447 0 : mst_state->commit_deps = kmalloc_array(num_commit_deps,
4448 : sizeof(*mst_state->commit_deps), GFP_KERNEL);
4449 0 : if (!mst_state->commit_deps)
4450 : return -ENOMEM;
4451 0 : mst_state->num_commit_deps = num_commit_deps;
4452 :
4453 0 : commit_idx = 0;
4454 0 : for_each_new_crtc_in_state(state, crtc, crtc_state, j) {
4455 0 : if (mst_state->pending_crtc_mask & drm_crtc_mask(crtc)) {
4456 0 : mst_state->commit_deps[commit_idx++] =
4457 0 : drm_crtc_commit_get(crtc_state->commit);
4458 : }
4459 : }
4460 : }
4461 :
4462 : return 0;
4463 : }
4464 : EXPORT_SYMBOL(drm_dp_mst_atomic_setup_commit);
4465 :
4466 : /**
4467 : * drm_dp_mst_atomic_wait_for_dependencies() - Wait for all pending commits on MST topologies,
4468 : * prepare new MST state for commit
4469 : * @state: global atomic state
4470 : *
4471 : * Goes through any MST topologies in this atomic state, and waits for any pending commits which
4472 : * touched CRTCs that were/are on an MST topology to be programmed to hardware and flipped to before
4473 : * returning. This is to prevent multiple non-blocking commits affecting an MST topology from racing
4474 : * with eachother by forcing them to be executed sequentially in situations where the only resources
4475 : * the modeset objects in these commits share are an MST topology.
4476 : *
4477 : * This function also prepares the new MST state for commit by performing some state preparation
4478 : * which can't be done until this point, such as reading back the final VC start slots (which are
4479 : * determined at commit-time) from the previous state.
4480 : *
4481 : * All MST drivers must call this function after calling drm_atomic_helper_wait_for_dependencies(),
4482 : * or whatever their equivalent of that is.
4483 : */
4484 0 : void drm_dp_mst_atomic_wait_for_dependencies(struct drm_atomic_state *state)
4485 : {
4486 : struct drm_dp_mst_topology_state *old_mst_state, *new_mst_state;
4487 : struct drm_dp_mst_topology_mgr *mgr;
4488 : struct drm_dp_mst_atomic_payload *old_payload, *new_payload;
4489 : int i, j, ret;
4490 :
4491 0 : for_each_oldnew_mst_mgr_in_state(state, mgr, old_mst_state, new_mst_state, i) {
4492 0 : for (j = 0; j < old_mst_state->num_commit_deps; j++) {
4493 0 : ret = drm_crtc_commit_wait(old_mst_state->commit_deps[j]);
4494 0 : if (ret < 0)
4495 0 : drm_err(state->dev, "Failed to wait for %s: %d\n",
4496 : old_mst_state->commit_deps[j]->crtc->name, ret);
4497 : }
4498 :
4499 : /* Now that previous state is committed, it's safe to copy over the start slot
4500 : * assignments
4501 : */
4502 0 : list_for_each_entry(old_payload, &old_mst_state->payloads, next) {
4503 0 : if (old_payload->delete)
4504 0 : continue;
4505 :
4506 0 : new_payload = drm_atomic_get_mst_payload_state(new_mst_state,
4507 : old_payload->port);
4508 0 : new_payload->vc_start_slot = old_payload->vc_start_slot;
4509 : }
4510 : }
4511 0 : }
4512 : EXPORT_SYMBOL(drm_dp_mst_atomic_wait_for_dependencies);
4513 :
4514 : /**
4515 : * drm_dp_mst_root_conn_atomic_check() - Serialize CRTC commits on MST-capable connectors operating
4516 : * in SST mode
4517 : * @new_conn_state: The new connector state of the &drm_connector
4518 : * @mgr: The MST topology manager for the &drm_connector
4519 : *
4520 : * Since MST uses fake &drm_encoder structs, the generic atomic modesetting code isn't able to
4521 : * serialize non-blocking commits happening on the real DP connector of an MST topology switching
4522 : * into/away from MST mode - as the CRTC on the real DP connector and the CRTCs on the connector's
4523 : * MST topology will never share the same &drm_encoder.
4524 : *
4525 : * This function takes care of this serialization issue, by checking a root MST connector's atomic
4526 : * state to determine if it is about to have a modeset - and then pulling in the MST topology state
4527 : * if so, along with adding any relevant CRTCs to &drm_dp_mst_topology_state.pending_crtc_mask.
4528 : *
4529 : * Drivers implementing MST must call this function from the
4530 : * &drm_connector_helper_funcs.atomic_check hook of any physical DP &drm_connector capable of
4531 : * driving MST sinks.
4532 : *
4533 : * Returns:
4534 : * 0 on success, negative error code otherwise
4535 : */
4536 0 : int drm_dp_mst_root_conn_atomic_check(struct drm_connector_state *new_conn_state,
4537 : struct drm_dp_mst_topology_mgr *mgr)
4538 : {
4539 0 : struct drm_atomic_state *state = new_conn_state->state;
4540 0 : struct drm_connector_state *old_conn_state =
4541 0 : drm_atomic_get_old_connector_state(state, new_conn_state->connector);
4542 : struct drm_crtc_state *crtc_state;
4543 0 : struct drm_dp_mst_topology_state *mst_state = NULL;
4544 :
4545 0 : if (new_conn_state->crtc) {
4546 0 : crtc_state = drm_atomic_get_new_crtc_state(state, new_conn_state->crtc);
4547 0 : if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) {
4548 0 : mst_state = drm_atomic_get_mst_topology_state(state, mgr);
4549 0 : if (IS_ERR(mst_state))
4550 0 : return PTR_ERR(mst_state);
4551 :
4552 0 : mst_state->pending_crtc_mask |= drm_crtc_mask(new_conn_state->crtc);
4553 : }
4554 : }
4555 :
4556 0 : if (old_conn_state->crtc) {
4557 0 : crtc_state = drm_atomic_get_new_crtc_state(state, old_conn_state->crtc);
4558 0 : if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) {
4559 0 : if (!mst_state) {
4560 0 : mst_state = drm_atomic_get_mst_topology_state(state, mgr);
4561 0 : if (IS_ERR(mst_state))
4562 0 : return PTR_ERR(mst_state);
4563 : }
4564 :
4565 0 : mst_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc);
4566 : }
4567 : }
4568 :
4569 : return 0;
4570 : }
4571 : EXPORT_SYMBOL(drm_dp_mst_root_conn_atomic_check);
4572 :
4573 : /**
4574 : * drm_dp_mst_update_slots() - updates the slot info depending on the DP ecoding format
4575 : * @mst_state: mst_state to update
4576 : * @link_encoding_cap: the ecoding format on the link
4577 : */
4578 0 : void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap)
4579 : {
4580 0 : if (link_encoding_cap == DP_CAP_ANSI_128B132B) {
4581 0 : mst_state->total_avail_slots = 64;
4582 0 : mst_state->start_slot = 0;
4583 : } else {
4584 0 : mst_state->total_avail_slots = 63;
4585 0 : mst_state->start_slot = 1;
4586 : }
4587 :
4588 0 : DRM_DEBUG_KMS("%s encoding format on mst_state 0x%p\n",
4589 : (link_encoding_cap == DP_CAP_ANSI_128B132B) ? "128b/132b":"8b/10b",
4590 : mst_state);
4591 0 : }
4592 : EXPORT_SYMBOL(drm_dp_mst_update_slots);
4593 :
4594 0 : static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
4595 : int id, u8 start_slot, u8 num_slots)
4596 : {
4597 : u8 payload_alloc[3], status;
4598 : int ret;
4599 0 : int retries = 0;
4600 :
4601 0 : drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
4602 : DP_PAYLOAD_TABLE_UPDATED);
4603 :
4604 0 : payload_alloc[0] = id;
4605 0 : payload_alloc[1] = start_slot;
4606 0 : payload_alloc[2] = num_slots;
4607 :
4608 0 : ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
4609 0 : if (ret != 3) {
4610 0 : drm_dbg_kms(mgr->dev, "failed to write payload allocation %d\n", ret);
4611 0 : goto fail;
4612 : }
4613 :
4614 : retry:
4615 0 : ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4616 0 : if (ret < 0) {
4617 0 : drm_dbg_kms(mgr->dev, "failed to read payload table status %d\n", ret);
4618 0 : goto fail;
4619 : }
4620 :
4621 0 : if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
4622 0 : retries++;
4623 0 : if (retries < 20) {
4624 : usleep_range(10000, 20000);
4625 : goto retry;
4626 : }
4627 0 : drm_dbg_kms(mgr->dev, "status not set after read payload table status %d\n",
4628 : status);
4629 0 : ret = -EINVAL;
4630 0 : goto fail;
4631 : }
4632 : ret = 0;
4633 : fail:
4634 0 : return ret;
4635 : }
4636 :
4637 : static int do_get_act_status(struct drm_dp_aux *aux)
4638 : {
4639 : int ret;
4640 : u8 status;
4641 :
4642 0 : ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4643 0 : if (ret < 0)
4644 : return ret;
4645 :
4646 0 : return status;
4647 : }
4648 :
4649 : /**
4650 : * drm_dp_check_act_status() - Polls for ACT handled status.
4651 : * @mgr: manager to use
4652 : *
4653 : * Tries waiting for the MST hub to finish updating it's payload table by
4654 : * polling for the ACT handled bit for up to 3 seconds (yes-some hubs really
4655 : * take that long).
4656 : *
4657 : * Returns:
4658 : * 0 if the ACT was handled in time, negative error code on failure.
4659 : */
4660 0 : int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
4661 : {
4662 : /*
4663 : * There doesn't seem to be any recommended retry count or timeout in
4664 : * the MST specification. Since some hubs have been observed to take
4665 : * over 1 second to update their payload allocations under certain
4666 : * conditions, we use a rather large timeout value.
4667 : */
4668 0 : const int timeout_ms = 3000;
4669 : int ret, status;
4670 :
4671 0 : ret = readx_poll_timeout(do_get_act_status, mgr->aux, status,
4672 : status & DP_PAYLOAD_ACT_HANDLED || status < 0,
4673 : 200, timeout_ms * USEC_PER_MSEC);
4674 0 : if (ret < 0 && status >= 0) {
4675 0 : drm_err(mgr->dev, "Failed to get ACT after %dms, last status: %02x\n",
4676 : timeout_ms, status);
4677 0 : return -EINVAL;
4678 0 : } else if (status < 0) {
4679 : /*
4680 : * Failure here isn't unexpected - the hub may have
4681 : * just been unplugged
4682 : */
4683 0 : drm_dbg_kms(mgr->dev, "Failed to read payload table status: %d\n", status);
4684 0 : return status;
4685 : }
4686 :
4687 : return 0;
4688 : }
4689 : EXPORT_SYMBOL(drm_dp_check_act_status);
4690 :
4691 : /**
4692 : * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
4693 : * @clock: dot clock for the mode
4694 : * @bpp: bpp for the mode.
4695 : * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel
4696 : *
4697 : * This uses the formula in the spec to calculate the PBN value for a mode.
4698 : */
4699 5 : int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc)
4700 : {
4701 : /*
4702 : * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
4703 : * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
4704 : * common multiplier to render an integer PBN for all link rate/lane
4705 : * counts combinations
4706 : * calculate
4707 : * peak_kbps *= (1006/1000)
4708 : * peak_kbps *= (64/54)
4709 : * peak_kbps *= 8 convert to bytes
4710 : *
4711 : * If the bpp is in units of 1/16, further divide by 16. Put this
4712 : * factor in the numerator rather than the denominator to avoid
4713 : * integer overflow
4714 : */
4715 :
4716 5 : if (dsc)
4717 4 : return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006),
4718 : 8 * 54 * 1000 * 1000);
4719 :
4720 6 : return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
4721 : 8 * 54 * 1000 * 1000);
4722 : }
4723 : EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
4724 :
4725 : /* we want to kick the TX after we've ack the up/down IRQs. */
4726 : static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
4727 : {
4728 0 : queue_work(system_long_wq, &mgr->tx_work);
4729 : }
4730 :
4731 : /*
4732 : * Helper function for parsing DP device types into convenient strings
4733 : * for use with dp_mst_topology
4734 : */
4735 : static const char *pdt_to_string(u8 pdt)
4736 : {
4737 : switch (pdt) {
4738 : case DP_PEER_DEVICE_NONE:
4739 : return "NONE";
4740 : case DP_PEER_DEVICE_SOURCE_OR_SST:
4741 : return "SOURCE OR SST";
4742 : case DP_PEER_DEVICE_MST_BRANCHING:
4743 : return "MST BRANCHING";
4744 : case DP_PEER_DEVICE_SST_SINK:
4745 : return "SST SINK";
4746 : case DP_PEER_DEVICE_DP_LEGACY_CONV:
4747 : return "DP LEGACY CONV";
4748 : default:
4749 : return "ERR";
4750 : }
4751 : }
4752 :
4753 0 : static void drm_dp_mst_dump_mstb(struct seq_file *m,
4754 : struct drm_dp_mst_branch *mstb)
4755 : {
4756 : struct drm_dp_mst_port *port;
4757 0 : int tabs = mstb->lct;
4758 : char prefix[10];
4759 : int i;
4760 :
4761 0 : for (i = 0; i < tabs; i++)
4762 0 : prefix[i] = '\t';
4763 0 : prefix[i] = '\0';
4764 :
4765 0 : seq_printf(m, "%smstb - [%p]: num_ports: %d\n", prefix, mstb, mstb->num_ports);
4766 0 : list_for_each_entry(port, &mstb->ports, next) {
4767 0 : seq_printf(m, "%sport %d - [%p] (%s - %s): ddps: %d, ldps: %d, sdp: %d/%d, fec: %s, conn: %p\n",
4768 : prefix,
4769 0 : port->port_num,
4770 : port,
4771 0 : port->input ? "input" : "output",
4772 0 : pdt_to_string(port->pdt),
4773 0 : port->ddps,
4774 0 : port->ldps,
4775 0 : port->num_sdp_streams,
4776 0 : port->num_sdp_stream_sinks,
4777 0 : port->fec_capable ? "true" : "false",
4778 : port->connector);
4779 0 : if (port->mstb)
4780 0 : drm_dp_mst_dump_mstb(m, port->mstb);
4781 : }
4782 0 : }
4783 :
4784 : #define DP_PAYLOAD_TABLE_SIZE 64
4785 :
4786 0 : static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
4787 : char *buf)
4788 : {
4789 : int i;
4790 :
4791 0 : for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
4792 0 : if (drm_dp_dpcd_read(mgr->aux,
4793 0 : DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
4794 0 : &buf[i], 16) != 16)
4795 : return false;
4796 : }
4797 : return true;
4798 : }
4799 :
4800 0 : static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
4801 : struct drm_dp_mst_port *port, char *name,
4802 : int namelen)
4803 : {
4804 : struct edid *mst_edid;
4805 :
4806 0 : mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
4807 0 : drm_edid_get_monitor_name(mst_edid, name, namelen);
4808 0 : kfree(mst_edid);
4809 0 : }
4810 :
4811 : /**
4812 : * drm_dp_mst_dump_topology(): dump topology to seq file.
4813 : * @m: seq_file to dump output to
4814 : * @mgr: manager to dump current topology for.
4815 : *
4816 : * helper to dump MST topology to a seq file for debugfs.
4817 : */
4818 0 : void drm_dp_mst_dump_topology(struct seq_file *m,
4819 : struct drm_dp_mst_topology_mgr *mgr)
4820 : {
4821 : struct drm_dp_mst_topology_state *state;
4822 : struct drm_dp_mst_atomic_payload *payload;
4823 : int i, ret;
4824 :
4825 0 : mutex_lock(&mgr->lock);
4826 0 : if (mgr->mst_primary)
4827 0 : drm_dp_mst_dump_mstb(m, mgr->mst_primary);
4828 :
4829 : /* dump VCPIs */
4830 0 : mutex_unlock(&mgr->lock);
4831 :
4832 0 : ret = drm_modeset_lock_single_interruptible(&mgr->base.lock);
4833 0 : if (ret < 0)
4834 : return;
4835 :
4836 0 : state = to_drm_dp_mst_topology_state(mgr->base.state);
4837 0 : seq_printf(m, "\n*** Atomic state info ***\n");
4838 0 : seq_printf(m, "payload_mask: %x, max_payloads: %d, start_slot: %u, pbn_div: %d\n",
4839 0 : state->payload_mask, mgr->max_payloads, state->start_slot, state->pbn_div);
4840 :
4841 0 : seq_printf(m, "\n| idx | port | vcpi | slots | pbn | dsc | sink name |\n");
4842 0 : for (i = 0; i < mgr->max_payloads; i++) {
4843 0 : list_for_each_entry(payload, &state->payloads, next) {
4844 : char name[14];
4845 :
4846 0 : if (payload->vcpi != i || payload->delete)
4847 0 : continue;
4848 :
4849 0 : fetch_monitor_name(mgr, payload->port, name, sizeof(name));
4850 0 : seq_printf(m, " %5d %6d %6d %02d - %02d %5d %5s %19s\n",
4851 : i,
4852 0 : payload->port->port_num,
4853 0 : payload->vcpi,
4854 : payload->vc_start_slot,
4855 0 : payload->vc_start_slot + payload->time_slots - 1,
4856 : payload->pbn,
4857 0 : payload->dsc_enabled ? "Y" : "N",
4858 0 : (*name != 0) ? name : "Unknown");
4859 : }
4860 : }
4861 :
4862 0 : seq_printf(m, "\n*** DPCD Info ***\n");
4863 0 : mutex_lock(&mgr->lock);
4864 0 : if (mgr->mst_primary) {
4865 : u8 buf[DP_PAYLOAD_TABLE_SIZE];
4866 : int ret;
4867 :
4868 0 : if (drm_dp_read_dpcd_caps(mgr->aux, buf) < 0) {
4869 0 : seq_printf(m, "dpcd read failed\n");
4870 0 : goto out;
4871 : }
4872 0 : seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
4873 :
4874 0 : ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
4875 0 : if (ret != 2) {
4876 0 : seq_printf(m, "faux/mst read failed\n");
4877 0 : goto out;
4878 : }
4879 0 : seq_printf(m, "faux/mst: %*ph\n", 2, buf);
4880 :
4881 0 : ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
4882 0 : if (ret != 1) {
4883 0 : seq_printf(m, "mst ctrl read failed\n");
4884 0 : goto out;
4885 : }
4886 0 : seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
4887 :
4888 : /* dump the standard OUI branch header */
4889 0 : ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
4890 0 : if (ret != DP_BRANCH_OUI_HEADER_SIZE) {
4891 0 : seq_printf(m, "branch oui read failed\n");
4892 0 : goto out;
4893 : }
4894 0 : seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
4895 :
4896 0 : for (i = 0x3; i < 0x8 && buf[i]; i++)
4897 0 : seq_printf(m, "%c", buf[i]);
4898 0 : seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
4899 0 : buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
4900 0 : if (dump_dp_payload_table(mgr, buf))
4901 0 : seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
4902 : }
4903 :
4904 : out:
4905 0 : mutex_unlock(&mgr->lock);
4906 0 : drm_modeset_unlock(&mgr->base.lock);
4907 : }
4908 : EXPORT_SYMBOL(drm_dp_mst_dump_topology);
4909 :
4910 0 : static void drm_dp_tx_work(struct work_struct *work)
4911 : {
4912 0 : struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
4913 :
4914 0 : mutex_lock(&mgr->qlock);
4915 0 : if (!list_empty(&mgr->tx_msg_downq))
4916 0 : process_single_down_tx_qlock(mgr);
4917 0 : mutex_unlock(&mgr->qlock);
4918 0 : }
4919 :
4920 : static inline void
4921 0 : drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port)
4922 : {
4923 0 : drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs);
4924 :
4925 0 : if (port->connector) {
4926 0 : drm_connector_unregister(port->connector);
4927 0 : drm_connector_put(port->connector);
4928 : }
4929 :
4930 0 : drm_dp_mst_put_port_malloc(port);
4931 0 : }
4932 :
4933 : static inline void
4934 0 : drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb)
4935 : {
4936 0 : struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
4937 : struct drm_dp_mst_port *port, *port_tmp;
4938 : struct drm_dp_sideband_msg_tx *txmsg, *txmsg_tmp;
4939 0 : bool wake_tx = false;
4940 :
4941 0 : mutex_lock(&mgr->lock);
4942 0 : list_for_each_entry_safe(port, port_tmp, &mstb->ports, next) {
4943 0 : list_del(&port->next);
4944 0 : drm_dp_mst_topology_put_port(port);
4945 : }
4946 0 : mutex_unlock(&mgr->lock);
4947 :
4948 : /* drop any tx slot msg */
4949 0 : mutex_lock(&mstb->mgr->qlock);
4950 0 : list_for_each_entry_safe(txmsg, txmsg_tmp, &mgr->tx_msg_downq, next) {
4951 0 : if (txmsg->dst != mstb)
4952 0 : continue;
4953 :
4954 0 : txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
4955 0 : list_del(&txmsg->next);
4956 0 : wake_tx = true;
4957 : }
4958 0 : mutex_unlock(&mstb->mgr->qlock);
4959 :
4960 0 : if (wake_tx)
4961 0 : wake_up_all(&mstb->mgr->tx_waitq);
4962 :
4963 0 : drm_dp_mst_put_mstb_malloc(mstb);
4964 0 : }
4965 :
4966 0 : static void drm_dp_delayed_destroy_work(struct work_struct *work)
4967 : {
4968 0 : struct drm_dp_mst_topology_mgr *mgr =
4969 0 : container_of(work, struct drm_dp_mst_topology_mgr,
4970 : delayed_destroy_work);
4971 0 : bool send_hotplug = false, go_again;
4972 :
4973 : /*
4974 : * Not a regular list traverse as we have to drop the destroy
4975 : * connector lock before destroying the mstb/port, to avoid AB->BA
4976 : * ordering between this lock and the config mutex.
4977 : */
4978 : do {
4979 0 : go_again = false;
4980 :
4981 0 : for (;;) {
4982 : struct drm_dp_mst_branch *mstb;
4983 :
4984 0 : mutex_lock(&mgr->delayed_destroy_lock);
4985 0 : mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list,
4986 : struct drm_dp_mst_branch,
4987 : destroy_next);
4988 0 : if (mstb)
4989 0 : list_del(&mstb->destroy_next);
4990 0 : mutex_unlock(&mgr->delayed_destroy_lock);
4991 :
4992 0 : if (!mstb)
4993 : break;
4994 :
4995 0 : drm_dp_delayed_destroy_mstb(mstb);
4996 0 : go_again = true;
4997 : }
4998 :
4999 0 : for (;;) {
5000 : struct drm_dp_mst_port *port;
5001 :
5002 0 : mutex_lock(&mgr->delayed_destroy_lock);
5003 0 : port = list_first_entry_or_null(&mgr->destroy_port_list,
5004 : struct drm_dp_mst_port,
5005 : next);
5006 0 : if (port)
5007 0 : list_del(&port->next);
5008 0 : mutex_unlock(&mgr->delayed_destroy_lock);
5009 :
5010 0 : if (!port)
5011 : break;
5012 :
5013 0 : drm_dp_delayed_destroy_port(port);
5014 0 : send_hotplug = true;
5015 0 : go_again = true;
5016 : }
5017 0 : } while (go_again);
5018 :
5019 0 : if (send_hotplug)
5020 0 : drm_kms_helper_hotplug_event(mgr->dev);
5021 0 : }
5022 :
5023 : static struct drm_private_state *
5024 0 : drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
5025 : {
5026 0 : struct drm_dp_mst_topology_state *state, *old_state =
5027 0 : to_dp_mst_topology_state(obj->state);
5028 : struct drm_dp_mst_atomic_payload *pos, *payload;
5029 :
5030 0 : state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
5031 0 : if (!state)
5032 : return NULL;
5033 :
5034 0 : __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
5035 :
5036 0 : INIT_LIST_HEAD(&state->payloads);
5037 0 : state->commit_deps = NULL;
5038 0 : state->num_commit_deps = 0;
5039 0 : state->pending_crtc_mask = 0;
5040 :
5041 0 : list_for_each_entry(pos, &old_state->payloads, next) {
5042 : /* Prune leftover freed timeslot allocations */
5043 0 : if (pos->delete)
5044 0 : continue;
5045 :
5046 0 : payload = kmemdup(pos, sizeof(*payload), GFP_KERNEL);
5047 0 : if (!payload)
5048 : goto fail;
5049 :
5050 0 : drm_dp_mst_get_port_malloc(payload->port);
5051 0 : list_add(&payload->next, &state->payloads);
5052 : }
5053 :
5054 : return &state->base;
5055 :
5056 : fail:
5057 0 : list_for_each_entry_safe(pos, payload, &state->payloads, next) {
5058 0 : drm_dp_mst_put_port_malloc(pos->port);
5059 0 : kfree(pos);
5060 : }
5061 0 : kfree(state);
5062 :
5063 0 : return NULL;
5064 : }
5065 :
5066 0 : static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
5067 : struct drm_private_state *state)
5068 : {
5069 0 : struct drm_dp_mst_topology_state *mst_state =
5070 0 : to_dp_mst_topology_state(state);
5071 : struct drm_dp_mst_atomic_payload *pos, *tmp;
5072 : int i;
5073 :
5074 0 : list_for_each_entry_safe(pos, tmp, &mst_state->payloads, next) {
5075 : /* We only keep references to ports with active payloads */
5076 0 : if (!pos->delete)
5077 0 : drm_dp_mst_put_port_malloc(pos->port);
5078 0 : kfree(pos);
5079 : }
5080 :
5081 0 : for (i = 0; i < mst_state->num_commit_deps; i++)
5082 0 : drm_crtc_commit_put(mst_state->commit_deps[i]);
5083 :
5084 0 : kfree(mst_state->commit_deps);
5085 0 : kfree(mst_state);
5086 0 : }
5087 :
5088 : static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
5089 : struct drm_dp_mst_branch *branch)
5090 : {
5091 0 : while (port->parent) {
5092 0 : if (port->parent == branch)
5093 : return true;
5094 :
5095 0 : if (port->parent->port_parent)
5096 : port = port->parent->port_parent;
5097 : else
5098 : break;
5099 : }
5100 : return false;
5101 : }
5102 :
5103 : static int
5104 : drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
5105 : struct drm_dp_mst_topology_state *state);
5106 :
5107 : static int
5108 0 : drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb,
5109 : struct drm_dp_mst_topology_state *state)
5110 : {
5111 : struct drm_dp_mst_atomic_payload *payload;
5112 : struct drm_dp_mst_port *port;
5113 0 : int pbn_used = 0, ret;
5114 0 : bool found = false;
5115 :
5116 : /* Check that we have at least one port in our state that's downstream
5117 : * of this branch, otherwise we can skip this branch
5118 : */
5119 0 : list_for_each_entry(payload, &state->payloads, next) {
5120 0 : if (!payload->pbn ||
5121 0 : !drm_dp_mst_port_downstream_of_branch(payload->port, mstb))
5122 0 : continue;
5123 :
5124 : found = true;
5125 : break;
5126 : }
5127 0 : if (!found)
5128 : return 0;
5129 :
5130 0 : if (mstb->port_parent)
5131 0 : drm_dbg_atomic(mstb->mgr->dev,
5132 : "[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n",
5133 : mstb->port_parent->parent, mstb->port_parent, mstb);
5134 : else
5135 0 : drm_dbg_atomic(mstb->mgr->dev, "[MSTB:%p] Checking bandwidth limits\n", mstb);
5136 :
5137 0 : list_for_each_entry(port, &mstb->ports, next) {
5138 0 : ret = drm_dp_mst_atomic_check_port_bw_limit(port, state);
5139 0 : if (ret < 0)
5140 : return ret;
5141 :
5142 0 : pbn_used += ret;
5143 : }
5144 :
5145 : return pbn_used;
5146 : }
5147 :
5148 : static int
5149 0 : drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
5150 : struct drm_dp_mst_topology_state *state)
5151 : {
5152 : struct drm_dp_mst_atomic_payload *payload;
5153 0 : int pbn_used = 0;
5154 :
5155 0 : if (port->pdt == DP_PEER_DEVICE_NONE)
5156 : return 0;
5157 :
5158 0 : if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
5159 0 : payload = drm_atomic_get_mst_payload_state(state, port);
5160 0 : if (!payload)
5161 : return 0;
5162 :
5163 : /*
5164 : * This could happen if the sink deasserted its HPD line, but
5165 : * the branch device still reports it as attached (PDT != NONE).
5166 : */
5167 0 : if (!port->full_pbn) {
5168 0 : drm_dbg_atomic(port->mgr->dev,
5169 : "[MSTB:%p] [MST PORT:%p] no BW available for the port\n",
5170 : port->parent, port);
5171 0 : return -EINVAL;
5172 : }
5173 :
5174 0 : pbn_used = payload->pbn;
5175 : } else {
5176 0 : pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb,
5177 : state);
5178 0 : if (pbn_used <= 0)
5179 : return pbn_used;
5180 : }
5181 :
5182 0 : if (pbn_used > port->full_pbn) {
5183 0 : drm_dbg_atomic(port->mgr->dev,
5184 : "[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n",
5185 : port->parent, port, pbn_used, port->full_pbn);
5186 0 : return -ENOSPC;
5187 : }
5188 :
5189 0 : drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n",
5190 : port->parent, port, pbn_used, port->full_pbn);
5191 :
5192 0 : return pbn_used;
5193 : }
5194 :
5195 : static inline int
5196 0 : drm_dp_mst_atomic_check_payload_alloc_limits(struct drm_dp_mst_topology_mgr *mgr,
5197 : struct drm_dp_mst_topology_state *mst_state)
5198 : {
5199 : struct drm_dp_mst_atomic_payload *payload;
5200 0 : int avail_slots = mst_state->total_avail_slots, payload_count = 0;
5201 :
5202 0 : list_for_each_entry(payload, &mst_state->payloads, next) {
5203 : /* Releasing payloads is always OK-even if the port is gone */
5204 0 : if (payload->delete) {
5205 0 : drm_dbg_atomic(mgr->dev, "[MST PORT:%p] releases all time slots\n",
5206 : payload->port);
5207 0 : continue;
5208 : }
5209 :
5210 0 : drm_dbg_atomic(mgr->dev, "[MST PORT:%p] requires %d time slots\n",
5211 : payload->port, payload->time_slots);
5212 :
5213 0 : avail_slots -= payload->time_slots;
5214 0 : if (avail_slots < 0) {
5215 0 : drm_dbg_atomic(mgr->dev,
5216 : "[MST PORT:%p] not enough time slots in mst state %p (avail=%d)\n",
5217 : payload->port, mst_state, avail_slots + payload->time_slots);
5218 0 : return -ENOSPC;
5219 : }
5220 :
5221 0 : if (++payload_count > mgr->max_payloads) {
5222 0 : drm_dbg_atomic(mgr->dev,
5223 : "[MST MGR:%p] state %p has too many payloads (max=%d)\n",
5224 : mgr, mst_state, mgr->max_payloads);
5225 0 : return -EINVAL;
5226 : }
5227 :
5228 : /* Assign a VCPI */
5229 0 : if (!payload->vcpi) {
5230 0 : payload->vcpi = ffz(mst_state->payload_mask) + 1;
5231 0 : drm_dbg_atomic(mgr->dev, "[MST PORT:%p] assigned VCPI #%d\n",
5232 : payload->port, payload->vcpi);
5233 0 : mst_state->payload_mask |= BIT(payload->vcpi - 1);
5234 : }
5235 : }
5236 :
5237 0 : if (!payload_count)
5238 0 : mst_state->pbn_div = 0;
5239 :
5240 0 : drm_dbg_atomic(mgr->dev, "[MST MGR:%p] mst state %p TU pbn_div=%d avail=%d used=%d\n",
5241 : mgr, mst_state, mst_state->pbn_div, avail_slots,
5242 : mst_state->total_avail_slots - avail_slots);
5243 :
5244 0 : return 0;
5245 : }
5246 :
5247 : /**
5248 : * drm_dp_mst_add_affected_dsc_crtcs
5249 : * @state: Pointer to the new struct drm_dp_mst_topology_state
5250 : * @mgr: MST topology manager
5251 : *
5252 : * Whenever there is a change in mst topology
5253 : * DSC configuration would have to be recalculated
5254 : * therefore we need to trigger modeset on all affected
5255 : * CRTCs in that topology
5256 : *
5257 : * See also:
5258 : * drm_dp_mst_atomic_enable_dsc()
5259 : */
5260 0 : int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr)
5261 : {
5262 : struct drm_dp_mst_topology_state *mst_state;
5263 : struct drm_dp_mst_atomic_payload *pos;
5264 : struct drm_connector *connector;
5265 : struct drm_connector_state *conn_state;
5266 : struct drm_crtc *crtc;
5267 : struct drm_crtc_state *crtc_state;
5268 :
5269 0 : mst_state = drm_atomic_get_mst_topology_state(state, mgr);
5270 :
5271 0 : if (IS_ERR(mst_state))
5272 0 : return PTR_ERR(mst_state);
5273 :
5274 0 : list_for_each_entry(pos, &mst_state->payloads, next) {
5275 :
5276 0 : connector = pos->port->connector;
5277 :
5278 0 : if (!connector)
5279 : return -EINVAL;
5280 :
5281 0 : conn_state = drm_atomic_get_connector_state(state, connector);
5282 :
5283 0 : if (IS_ERR(conn_state))
5284 0 : return PTR_ERR(conn_state);
5285 :
5286 0 : crtc = conn_state->crtc;
5287 :
5288 0 : if (!crtc)
5289 0 : continue;
5290 :
5291 0 : if (!drm_dp_mst_dsc_aux_for_port(pos->port))
5292 0 : continue;
5293 :
5294 0 : crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc);
5295 :
5296 0 : if (IS_ERR(crtc_state))
5297 0 : return PTR_ERR(crtc_state);
5298 :
5299 0 : drm_dbg_atomic(mgr->dev, "[MST MGR:%p] Setting mode_changed flag on CRTC %p\n",
5300 : mgr, crtc);
5301 :
5302 0 : crtc_state->mode_changed = true;
5303 : }
5304 : return 0;
5305 : }
5306 : EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs);
5307 :
5308 : /**
5309 : * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off
5310 : * @state: Pointer to the new drm_atomic_state
5311 : * @port: Pointer to the affected MST Port
5312 : * @pbn: Newly recalculated bw required for link with DSC enabled
5313 : * @enable: Boolean flag to enable or disable DSC on the port
5314 : *
5315 : * This function enables DSC on the given Port
5316 : * by recalculating its vcpi from pbn provided
5317 : * and sets dsc_enable flag to keep track of which
5318 : * ports have DSC enabled
5319 : *
5320 : */
5321 0 : int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
5322 : struct drm_dp_mst_port *port,
5323 : int pbn, bool enable)
5324 : {
5325 : struct drm_dp_mst_topology_state *mst_state;
5326 : struct drm_dp_mst_atomic_payload *payload;
5327 0 : int time_slots = 0;
5328 :
5329 0 : mst_state = drm_atomic_get_mst_topology_state(state, port->mgr);
5330 0 : if (IS_ERR(mst_state))
5331 0 : return PTR_ERR(mst_state);
5332 :
5333 0 : payload = drm_atomic_get_mst_payload_state(mst_state, port);
5334 0 : if (!payload) {
5335 0 : drm_dbg_atomic(state->dev,
5336 : "[MST PORT:%p] Couldn't find payload in mst state %p\n",
5337 : port, mst_state);
5338 0 : return -EINVAL;
5339 : }
5340 :
5341 0 : if (payload->dsc_enabled == enable) {
5342 0 : drm_dbg_atomic(state->dev,
5343 : "[MST PORT:%p] DSC flag is already set to %d, returning %d time slots\n",
5344 : port, enable, payload->time_slots);
5345 0 : time_slots = payload->time_slots;
5346 : }
5347 :
5348 0 : if (enable) {
5349 0 : time_slots = drm_dp_atomic_find_time_slots(state, port->mgr, port, pbn);
5350 0 : drm_dbg_atomic(state->dev,
5351 : "[MST PORT:%p] Enabling DSC flag, reallocating %d time slots on the port\n",
5352 : port, time_slots);
5353 0 : if (time_slots < 0)
5354 : return -EINVAL;
5355 : }
5356 :
5357 0 : payload->dsc_enabled = enable;
5358 :
5359 0 : return time_slots;
5360 : }
5361 : EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc);
5362 :
5363 : /**
5364 : * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
5365 : * atomic update is valid
5366 : * @state: Pointer to the new &struct drm_dp_mst_topology_state
5367 : *
5368 : * Checks the given topology state for an atomic update to ensure that it's
5369 : * valid. This includes checking whether there's enough bandwidth to support
5370 : * the new timeslot allocations in the atomic update.
5371 : *
5372 : * Any atomic drivers supporting DP MST must make sure to call this after
5373 : * checking the rest of their state in their
5374 : * &drm_mode_config_funcs.atomic_check() callback.
5375 : *
5376 : * See also:
5377 : * drm_dp_atomic_find_time_slots()
5378 : * drm_dp_atomic_release_time_slots()
5379 : *
5380 : * Returns:
5381 : *
5382 : * 0 if the new state is valid, negative error code otherwise.
5383 : */
5384 0 : int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
5385 : {
5386 : struct drm_dp_mst_topology_mgr *mgr;
5387 : struct drm_dp_mst_topology_state *mst_state;
5388 0 : int i, ret = 0;
5389 :
5390 0 : for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
5391 0 : if (!mgr->mst_state)
5392 0 : continue;
5393 :
5394 0 : ret = drm_dp_mst_atomic_check_payload_alloc_limits(mgr, mst_state);
5395 0 : if (ret)
5396 : break;
5397 :
5398 0 : mutex_lock(&mgr->lock);
5399 0 : ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary,
5400 : mst_state);
5401 0 : mutex_unlock(&mgr->lock);
5402 0 : if (ret < 0)
5403 : break;
5404 : else
5405 : ret = 0;
5406 : }
5407 :
5408 0 : return ret;
5409 : }
5410 : EXPORT_SYMBOL(drm_dp_mst_atomic_check);
5411 :
5412 : const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
5413 : .atomic_duplicate_state = drm_dp_mst_duplicate_state,
5414 : .atomic_destroy_state = drm_dp_mst_destroy_state,
5415 : };
5416 : EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
5417 :
5418 : /**
5419 : * drm_atomic_get_mst_topology_state: get MST topology state
5420 : * @state: global atomic state
5421 : * @mgr: MST topology manager, also the private object in this case
5422 : *
5423 : * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
5424 : * state vtable so that the private object state returned is that of a MST
5425 : * topology object.
5426 : *
5427 : * RETURNS:
5428 : *
5429 : * The MST topology state or error pointer.
5430 : */
5431 0 : struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
5432 : struct drm_dp_mst_topology_mgr *mgr)
5433 : {
5434 0 : return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
5435 : }
5436 : EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
5437 :
5438 : /**
5439 : * drm_atomic_get_old_mst_topology_state: get old MST topology state in atomic state, if any
5440 : * @state: global atomic state
5441 : * @mgr: MST topology manager, also the private object in this case
5442 : *
5443 : * This function wraps drm_atomic_get_old_private_obj_state() passing in the MST atomic
5444 : * state vtable so that the private object state returned is that of a MST
5445 : * topology object.
5446 : *
5447 : * Returns:
5448 : *
5449 : * The old MST topology state, or NULL if there's no topology state for this MST mgr
5450 : * in the global atomic state
5451 : */
5452 : struct drm_dp_mst_topology_state *
5453 0 : drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state,
5454 : struct drm_dp_mst_topology_mgr *mgr)
5455 : {
5456 0 : struct drm_private_state *old_priv_state =
5457 0 : drm_atomic_get_old_private_obj_state(state, &mgr->base);
5458 :
5459 0 : return old_priv_state ? to_dp_mst_topology_state(old_priv_state) : NULL;
5460 : }
5461 : EXPORT_SYMBOL(drm_atomic_get_old_mst_topology_state);
5462 :
5463 : /**
5464 : * drm_atomic_get_new_mst_topology_state: get new MST topology state in atomic state, if any
5465 : * @state: global atomic state
5466 : * @mgr: MST topology manager, also the private object in this case
5467 : *
5468 : * This function wraps drm_atomic_get_new_private_obj_state() passing in the MST atomic
5469 : * state vtable so that the private object state returned is that of a MST
5470 : * topology object.
5471 : *
5472 : * Returns:
5473 : *
5474 : * The new MST topology state, or NULL if there's no topology state for this MST mgr
5475 : * in the global atomic state
5476 : */
5477 : struct drm_dp_mst_topology_state *
5478 0 : drm_atomic_get_new_mst_topology_state(struct drm_atomic_state *state,
5479 : struct drm_dp_mst_topology_mgr *mgr)
5480 : {
5481 0 : struct drm_private_state *new_priv_state =
5482 0 : drm_atomic_get_new_private_obj_state(state, &mgr->base);
5483 :
5484 0 : return new_priv_state ? to_dp_mst_topology_state(new_priv_state) : NULL;
5485 : }
5486 : EXPORT_SYMBOL(drm_atomic_get_new_mst_topology_state);
5487 :
5488 : /**
5489 : * drm_dp_mst_topology_mgr_init - initialise a topology manager
5490 : * @mgr: manager struct to initialise
5491 : * @dev: device providing this structure - for i2c addition.
5492 : * @aux: DP helper aux channel to talk to this device
5493 : * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
5494 : * @max_payloads: maximum number of payloads this GPU can source
5495 : * @conn_base_id: the connector object ID the MST device is connected to.
5496 : *
5497 : * Return 0 for success, or negative error code on failure
5498 : */
5499 0 : int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
5500 : struct drm_device *dev, struct drm_dp_aux *aux,
5501 : int max_dpcd_transaction_bytes, int max_payloads,
5502 : int conn_base_id)
5503 : {
5504 : struct drm_dp_mst_topology_state *mst_state;
5505 :
5506 0 : mutex_init(&mgr->lock);
5507 0 : mutex_init(&mgr->qlock);
5508 0 : mutex_init(&mgr->delayed_destroy_lock);
5509 0 : mutex_init(&mgr->up_req_lock);
5510 0 : mutex_init(&mgr->probe_lock);
5511 : #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5512 : mutex_init(&mgr->topology_ref_history_lock);
5513 : stack_depot_init();
5514 : #endif
5515 0 : INIT_LIST_HEAD(&mgr->tx_msg_downq);
5516 0 : INIT_LIST_HEAD(&mgr->destroy_port_list);
5517 0 : INIT_LIST_HEAD(&mgr->destroy_branch_device_list);
5518 0 : INIT_LIST_HEAD(&mgr->up_req_list);
5519 :
5520 : /*
5521 : * delayed_destroy_work will be queued on a dedicated WQ, so that any
5522 : * requeuing will be also flushed when deiniting the topology manager.
5523 : */
5524 0 : mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0);
5525 0 : if (mgr->delayed_destroy_wq == NULL)
5526 : return -ENOMEM;
5527 :
5528 0 : INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
5529 0 : INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
5530 0 : INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work);
5531 0 : INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work);
5532 0 : init_waitqueue_head(&mgr->tx_waitq);
5533 0 : mgr->dev = dev;
5534 0 : mgr->aux = aux;
5535 0 : mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
5536 0 : mgr->max_payloads = max_payloads;
5537 0 : mgr->conn_base_id = conn_base_id;
5538 :
5539 0 : mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
5540 0 : if (mst_state == NULL)
5541 : return -ENOMEM;
5542 :
5543 0 : mst_state->total_avail_slots = 63;
5544 0 : mst_state->start_slot = 1;
5545 :
5546 0 : mst_state->mgr = mgr;
5547 0 : INIT_LIST_HEAD(&mst_state->payloads);
5548 :
5549 0 : drm_atomic_private_obj_init(dev, &mgr->base,
5550 : &mst_state->base,
5551 : &drm_dp_mst_topology_state_funcs);
5552 :
5553 0 : return 0;
5554 : }
5555 : EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
5556 :
5557 : /**
5558 : * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
5559 : * @mgr: manager to destroy
5560 : */
5561 0 : void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
5562 : {
5563 0 : drm_dp_mst_topology_mgr_set_mst(mgr, false);
5564 0 : flush_work(&mgr->work);
5565 : /* The following will also drain any requeued work on the WQ. */
5566 0 : if (mgr->delayed_destroy_wq) {
5567 0 : destroy_workqueue(mgr->delayed_destroy_wq);
5568 0 : mgr->delayed_destroy_wq = NULL;
5569 : }
5570 0 : mgr->dev = NULL;
5571 0 : mgr->aux = NULL;
5572 0 : drm_atomic_private_obj_fini(&mgr->base);
5573 0 : mgr->funcs = NULL;
5574 :
5575 0 : mutex_destroy(&mgr->delayed_destroy_lock);
5576 0 : mutex_destroy(&mgr->qlock);
5577 0 : mutex_destroy(&mgr->lock);
5578 0 : mutex_destroy(&mgr->up_req_lock);
5579 0 : mutex_destroy(&mgr->probe_lock);
5580 : #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5581 : mutex_destroy(&mgr->topology_ref_history_lock);
5582 : #endif
5583 0 : }
5584 : EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
5585 :
5586 0 : static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
5587 : {
5588 : int i;
5589 :
5590 0 : if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
5591 : return false;
5592 :
5593 0 : for (i = 0; i < num - 1; i++) {
5594 0 : if (msgs[i].flags & I2C_M_RD ||
5595 0 : msgs[i].len > 0xff)
5596 : return false;
5597 : }
5598 :
5599 0 : return msgs[num - 1].flags & I2C_M_RD &&
5600 0 : msgs[num - 1].len <= 0xff;
5601 : }
5602 :
5603 0 : static bool remote_i2c_write_ok(const struct i2c_msg msgs[], int num)
5604 : {
5605 : int i;
5606 :
5607 0 : for (i = 0; i < num - 1; i++) {
5608 0 : if (msgs[i].flags & I2C_M_RD || !(msgs[i].flags & I2C_M_STOP) ||
5609 0 : msgs[i].len > 0xff)
5610 : return false;
5611 : }
5612 :
5613 0 : return !(msgs[num - 1].flags & I2C_M_RD) && msgs[num - 1].len <= 0xff;
5614 : }
5615 :
5616 0 : static int drm_dp_mst_i2c_read(struct drm_dp_mst_branch *mstb,
5617 : struct drm_dp_mst_port *port,
5618 : struct i2c_msg *msgs, int num)
5619 : {
5620 0 : struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5621 : unsigned int i;
5622 : struct drm_dp_sideband_msg_req_body msg;
5623 0 : struct drm_dp_sideband_msg_tx *txmsg = NULL;
5624 : int ret;
5625 :
5626 0 : memset(&msg, 0, sizeof(msg));
5627 0 : msg.req_type = DP_REMOTE_I2C_READ;
5628 0 : msg.u.i2c_read.num_transactions = num - 1;
5629 0 : msg.u.i2c_read.port_number = port->port_num;
5630 0 : for (i = 0; i < num - 1; i++) {
5631 0 : msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
5632 0 : msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
5633 0 : msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
5634 0 : msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
5635 : }
5636 0 : msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
5637 0 : msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
5638 :
5639 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5640 0 : if (!txmsg) {
5641 : ret = -ENOMEM;
5642 : goto out;
5643 : }
5644 :
5645 0 : txmsg->dst = mstb;
5646 0 : drm_dp_encode_sideband_req(&msg, txmsg);
5647 :
5648 0 : drm_dp_queue_down_tx(mgr, txmsg);
5649 :
5650 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5651 0 : if (ret > 0) {
5652 :
5653 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5654 : ret = -EREMOTEIO;
5655 : goto out;
5656 : }
5657 0 : if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
5658 : ret = -EIO;
5659 : goto out;
5660 : }
5661 0 : memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
5662 0 : ret = num;
5663 : }
5664 : out:
5665 0 : kfree(txmsg);
5666 0 : return ret;
5667 : }
5668 :
5669 0 : static int drm_dp_mst_i2c_write(struct drm_dp_mst_branch *mstb,
5670 : struct drm_dp_mst_port *port,
5671 : struct i2c_msg *msgs, int num)
5672 : {
5673 0 : struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5674 : unsigned int i;
5675 : struct drm_dp_sideband_msg_req_body msg;
5676 0 : struct drm_dp_sideband_msg_tx *txmsg = NULL;
5677 : int ret;
5678 :
5679 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5680 0 : if (!txmsg) {
5681 : ret = -ENOMEM;
5682 : goto out;
5683 : }
5684 0 : for (i = 0; i < num; i++) {
5685 0 : memset(&msg, 0, sizeof(msg));
5686 0 : msg.req_type = DP_REMOTE_I2C_WRITE;
5687 0 : msg.u.i2c_write.port_number = port->port_num;
5688 0 : msg.u.i2c_write.write_i2c_device_id = msgs[i].addr;
5689 0 : msg.u.i2c_write.num_bytes = msgs[i].len;
5690 0 : msg.u.i2c_write.bytes = msgs[i].buf;
5691 :
5692 0 : memset(txmsg, 0, sizeof(*txmsg));
5693 0 : txmsg->dst = mstb;
5694 :
5695 0 : drm_dp_encode_sideband_req(&msg, txmsg);
5696 0 : drm_dp_queue_down_tx(mgr, txmsg);
5697 :
5698 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5699 0 : if (ret > 0) {
5700 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5701 : ret = -EREMOTEIO;
5702 : goto out;
5703 : }
5704 : } else {
5705 : goto out;
5706 : }
5707 : }
5708 : ret = num;
5709 : out:
5710 0 : kfree(txmsg);
5711 0 : return ret;
5712 : }
5713 :
5714 : /* I2C device */
5715 0 : static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter,
5716 : struct i2c_msg *msgs, int num)
5717 : {
5718 0 : struct drm_dp_aux *aux = adapter->algo_data;
5719 0 : struct drm_dp_mst_port *port =
5720 0 : container_of(aux, struct drm_dp_mst_port, aux);
5721 : struct drm_dp_mst_branch *mstb;
5722 0 : struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5723 : int ret;
5724 :
5725 0 : mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
5726 0 : if (!mstb)
5727 : return -EREMOTEIO;
5728 :
5729 0 : if (remote_i2c_read_ok(msgs, num)) {
5730 0 : ret = drm_dp_mst_i2c_read(mstb, port, msgs, num);
5731 0 : } else if (remote_i2c_write_ok(msgs, num)) {
5732 0 : ret = drm_dp_mst_i2c_write(mstb, port, msgs, num);
5733 : } else {
5734 0 : drm_dbg_kms(mgr->dev, "Unsupported I2C transaction for MST device\n");
5735 0 : ret = -EIO;
5736 : }
5737 :
5738 0 : drm_dp_mst_topology_put_mstb(mstb);
5739 0 : return ret;
5740 : }
5741 :
5742 0 : static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
5743 : {
5744 0 : return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
5745 : I2C_FUNC_SMBUS_READ_BLOCK_DATA |
5746 : I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
5747 : I2C_FUNC_10BIT_ADDR;
5748 : }
5749 :
5750 : static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
5751 : .functionality = drm_dp_mst_i2c_functionality,
5752 : .master_xfer = drm_dp_mst_i2c_xfer,
5753 : };
5754 :
5755 : /**
5756 : * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
5757 : * @port: The port to add the I2C bus on
5758 : *
5759 : * Returns 0 on success or a negative error code on failure.
5760 : */
5761 0 : static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port)
5762 : {
5763 0 : struct drm_dp_aux *aux = &port->aux;
5764 0 : struct device *parent_dev = port->mgr->dev->dev;
5765 :
5766 0 : aux->ddc.algo = &drm_dp_mst_i2c_algo;
5767 0 : aux->ddc.algo_data = aux;
5768 0 : aux->ddc.retries = 3;
5769 :
5770 0 : aux->ddc.class = I2C_CLASS_DDC;
5771 0 : aux->ddc.owner = THIS_MODULE;
5772 : /* FIXME: set the kdev of the port's connector as parent */
5773 0 : aux->ddc.dev.parent = parent_dev;
5774 0 : aux->ddc.dev.of_node = parent_dev->of_node;
5775 :
5776 0 : strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev),
5777 : sizeof(aux->ddc.name));
5778 :
5779 0 : return i2c_add_adapter(&aux->ddc);
5780 : }
5781 :
5782 : /**
5783 : * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
5784 : * @port: The port to remove the I2C bus from
5785 : */
5786 : static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port)
5787 : {
5788 0 : i2c_del_adapter(&port->aux.ddc);
5789 : }
5790 :
5791 : /**
5792 : * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device
5793 : * @port: The port to check
5794 : *
5795 : * A single physical MST hub object can be represented in the topology
5796 : * by multiple branches, with virtual ports between those branches.
5797 : *
5798 : * As of DP1.4, An MST hub with internal (virtual) ports must expose
5799 : * certain DPCD registers over those ports. See sections 2.6.1.1.1
5800 : * and 2.6.1.1.2 of Display Port specification v1.4 for details.
5801 : *
5802 : * May acquire mgr->lock
5803 : *
5804 : * Returns:
5805 : * true if the port is a virtual DP peer device, false otherwise
5806 : */
5807 0 : static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port)
5808 : {
5809 : struct drm_dp_mst_port *downstream_port;
5810 :
5811 0 : if (!port || port->dpcd_rev < DP_DPCD_REV_14)
5812 : return false;
5813 :
5814 : /* Virtual DP Sink (Internal Display Panel) */
5815 0 : if (port->port_num >= 8)
5816 : return true;
5817 :
5818 : /* DP-to-HDMI Protocol Converter */
5819 0 : if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV &&
5820 0 : !port->mcs &&
5821 0 : port->ldps)
5822 : return true;
5823 :
5824 : /* DP-to-DP */
5825 0 : mutex_lock(&port->mgr->lock);
5826 0 : if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
5827 0 : port->mstb &&
5828 0 : port->mstb->num_ports == 2) {
5829 0 : list_for_each_entry(downstream_port, &port->mstb->ports, next) {
5830 0 : if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK &&
5831 0 : !downstream_port->input) {
5832 0 : mutex_unlock(&port->mgr->lock);
5833 0 : return true;
5834 : }
5835 : }
5836 : }
5837 0 : mutex_unlock(&port->mgr->lock);
5838 :
5839 0 : return false;
5840 : }
5841 :
5842 : /**
5843 : * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
5844 : * @port: The port to check. A leaf of the MST tree with an attached display.
5845 : *
5846 : * Depending on the situation, DSC may be enabled via the endpoint aux,
5847 : * the immediately upstream aux, or the connector's physical aux.
5848 : *
5849 : * This is both the correct aux to read DSC_CAPABILITY and the
5850 : * correct aux to write DSC_ENABLED.
5851 : *
5852 : * This operation can be expensive (up to four aux reads), so
5853 : * the caller should cache the return.
5854 : *
5855 : * Returns:
5856 : * NULL if DSC cannot be enabled on this port, otherwise the aux device
5857 : */
5858 0 : struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
5859 : {
5860 : struct drm_dp_mst_port *immediate_upstream_port;
5861 : struct drm_dp_mst_port *fec_port;
5862 0 : struct drm_dp_desc desc = {};
5863 : u8 endpoint_fec;
5864 : u8 endpoint_dsc;
5865 :
5866 0 : if (!port)
5867 : return NULL;
5868 :
5869 0 : if (port->parent->port_parent)
5870 0 : immediate_upstream_port = port->parent->port_parent;
5871 : else
5872 : immediate_upstream_port = NULL;
5873 :
5874 0 : fec_port = immediate_upstream_port;
5875 0 : while (fec_port) {
5876 : /*
5877 : * Each physical link (i.e. not a virtual port) between the
5878 : * output and the primary device must support FEC
5879 : */
5880 0 : if (!drm_dp_mst_is_virtual_dpcd(fec_port) &&
5881 0 : !fec_port->fec_capable)
5882 : return NULL;
5883 :
5884 0 : fec_port = fec_port->parent->port_parent;
5885 : }
5886 :
5887 : /* DP-to-DP peer device */
5888 0 : if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) {
5889 : u8 upstream_dsc;
5890 :
5891 0 : if (drm_dp_dpcd_read(&port->aux,
5892 : DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5893 : return NULL;
5894 0 : if (drm_dp_dpcd_read(&port->aux,
5895 : DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5896 : return NULL;
5897 0 : if (drm_dp_dpcd_read(&immediate_upstream_port->aux,
5898 : DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
5899 : return NULL;
5900 :
5901 : /* Enpoint decompression with DP-to-DP peer device */
5902 0 : if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5903 0 : (endpoint_fec & DP_FEC_CAPABLE) &&
5904 0 : (upstream_dsc & DP_DSC_PASSTHROUGH_IS_SUPPORTED)) {
5905 0 : port->passthrough_aux = &immediate_upstream_port->aux;
5906 0 : return &port->aux;
5907 : }
5908 :
5909 : /* Virtual DPCD decompression with DP-to-DP peer device */
5910 : return &immediate_upstream_port->aux;
5911 : }
5912 :
5913 : /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */
5914 0 : if (drm_dp_mst_is_virtual_dpcd(port))
5915 0 : return &port->aux;
5916 :
5917 : /*
5918 : * Synaptics quirk
5919 : * Applies to ports for which:
5920 : * - Physical aux has Synaptics OUI
5921 : * - DPv1.4 or higher
5922 : * - Port is on primary branch device
5923 : * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG)
5924 : */
5925 0 : if (drm_dp_read_desc(port->mgr->aux, &desc, true))
5926 : return NULL;
5927 :
5928 0 : if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) &&
5929 0 : port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 &&
5930 0 : port->parent == port->mgr->mst_primary) {
5931 : u8 dpcd_ext[DP_RECEIVER_CAP_SIZE];
5932 :
5933 0 : if (drm_dp_read_dpcd_caps(port->mgr->aux, dpcd_ext) < 0)
5934 0 : return NULL;
5935 :
5936 0 : if ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT) &&
5937 : ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK)
5938 : != DP_DWN_STRM_PORT_TYPE_ANALOG))
5939 0 : return port->mgr->aux;
5940 : }
5941 :
5942 : /*
5943 : * The check below verifies if the MST sink
5944 : * connected to the GPU is capable of DSC -
5945 : * therefore the endpoint needs to be
5946 : * both DSC and FEC capable.
5947 : */
5948 0 : if (drm_dp_dpcd_read(&port->aux,
5949 : DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5950 : return NULL;
5951 0 : if (drm_dp_dpcd_read(&port->aux,
5952 : DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5953 : return NULL;
5954 0 : if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5955 0 : (endpoint_fec & DP_FEC_CAPABLE))
5956 0 : return &port->aux;
5957 :
5958 : return NULL;
5959 : }
5960 : EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);
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