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_print.h>
46 : #include <drm/drm_probe_helper.h>
47 :
48 : #include "drm_dp_helper_internal.h"
49 : #include "drm_dp_mst_topology_internal.h"
50 :
51 : /**
52 : * DOC: dp mst helper
53 : *
54 : * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
55 : * protocol. The helpers contain a topology manager and bandwidth manager.
56 : * The helpers encapsulate the sending and received of sideband msgs.
57 : */
58 : struct drm_dp_pending_up_req {
59 : struct drm_dp_sideband_msg_hdr hdr;
60 : struct drm_dp_sideband_msg_req_body msg;
61 : struct list_head next;
62 : };
63 :
64 : static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
65 : char *buf);
66 :
67 : static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
68 :
69 : static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
70 : int id,
71 : struct drm_dp_payload *payload);
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 0 : drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
333 : struct drm_dp_sideband_msg_tx *raw)
334 : {
335 0 : int idx = 0;
336 : int i;
337 0 : u8 *buf = raw->msg;
338 :
339 0 : buf[idx++] = req->req_type & 0x7f;
340 :
341 0 : switch (req->req_type) {
342 : case DP_ENUM_PATH_RESOURCES:
343 : case DP_POWER_DOWN_PHY:
344 : case DP_POWER_UP_PHY:
345 0 : buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
346 0 : idx++;
347 0 : break;
348 : case DP_ALLOCATE_PAYLOAD:
349 0 : buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
350 0 : (req->u.allocate_payload.number_sdp_streams & 0xf);
351 0 : idx++;
352 0 : buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
353 0 : idx++;
354 0 : buf[idx] = (req->u.allocate_payload.pbn >> 8);
355 0 : idx++;
356 0 : buf[idx] = (req->u.allocate_payload.pbn & 0xff);
357 0 : idx++;
358 0 : for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
359 0 : buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
360 0 : (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
361 0 : idx++;
362 : }
363 0 : if (req->u.allocate_payload.number_sdp_streams & 1) {
364 0 : i = req->u.allocate_payload.number_sdp_streams - 1;
365 0 : buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
366 0 : idx++;
367 : }
368 : break;
369 : case DP_QUERY_PAYLOAD:
370 0 : buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
371 0 : idx++;
372 0 : buf[idx] = (req->u.query_payload.vcpi & 0x7f);
373 0 : idx++;
374 0 : break;
375 : case DP_REMOTE_DPCD_READ:
376 0 : buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
377 0 : buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
378 0 : idx++;
379 0 : buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
380 0 : idx++;
381 0 : buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
382 0 : idx++;
383 0 : buf[idx] = (req->u.dpcd_read.num_bytes);
384 0 : idx++;
385 0 : break;
386 :
387 : case DP_REMOTE_DPCD_WRITE:
388 0 : buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
389 0 : buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
390 0 : idx++;
391 0 : buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
392 0 : idx++;
393 0 : buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
394 0 : idx++;
395 0 : buf[idx] = (req->u.dpcd_write.num_bytes);
396 0 : idx++;
397 0 : memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
398 0 : idx += req->u.dpcd_write.num_bytes;
399 0 : break;
400 : case DP_REMOTE_I2C_READ:
401 0 : buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
402 0 : buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
403 0 : idx++;
404 0 : for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
405 0 : buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
406 0 : idx++;
407 0 : buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
408 0 : idx++;
409 0 : memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
410 0 : idx += req->u.i2c_read.transactions[i].num_bytes;
411 :
412 0 : buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
413 0 : buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
414 0 : idx++;
415 : }
416 0 : buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
417 0 : idx++;
418 0 : buf[idx] = (req->u.i2c_read.num_bytes_read);
419 0 : idx++;
420 0 : break;
421 :
422 : case DP_REMOTE_I2C_WRITE:
423 0 : buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
424 0 : idx++;
425 0 : buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
426 0 : idx++;
427 0 : buf[idx] = (req->u.i2c_write.num_bytes);
428 0 : idx++;
429 0 : memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
430 0 : idx += req->u.i2c_write.num_bytes;
431 0 : break;
432 : case DP_QUERY_STREAM_ENC_STATUS: {
433 : const struct drm_dp_query_stream_enc_status *msg;
434 :
435 0 : msg = &req->u.enc_status;
436 0 : buf[idx] = msg->stream_id;
437 0 : idx++;
438 0 : memcpy(&buf[idx], msg->client_id, sizeof(msg->client_id));
439 0 : idx += sizeof(msg->client_id);
440 0 : buf[idx] = 0;
441 0 : buf[idx] |= FIELD_PREP(GENMASK(1, 0), msg->stream_event);
442 0 : buf[idx] |= msg->valid_stream_event ? BIT(2) : 0;
443 0 : buf[idx] |= FIELD_PREP(GENMASK(4, 3), msg->stream_behavior);
444 0 : buf[idx] |= msg->valid_stream_behavior ? BIT(5) : 0;
445 0 : idx++;
446 : }
447 0 : break;
448 : }
449 0 : raw->cur_len = idx;
450 0 : }
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 0 : drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
456 : struct drm_dp_sideband_msg_req_body *req)
457 : {
458 0 : const u8 *buf = raw->msg;
459 0 : int i, idx = 0;
460 :
461 0 : req->req_type = buf[idx++] & 0x7f;
462 0 : switch (req->req_type) {
463 : case DP_ENUM_PATH_RESOURCES:
464 : case DP_POWER_DOWN_PHY:
465 : case DP_POWER_UP_PHY:
466 0 : req->u.port_num.port_number = (buf[idx] >> 4) & 0xf;
467 0 : break;
468 : case DP_ALLOCATE_PAYLOAD:
469 : {
470 0 : struct drm_dp_allocate_payload *a =
471 : &req->u.allocate_payload;
472 :
473 0 : a->number_sdp_streams = buf[idx] & 0xf;
474 0 : a->port_number = (buf[idx] >> 4) & 0xf;
475 :
476 0 : WARN_ON(buf[++idx] & 0x80);
477 0 : a->vcpi = buf[idx] & 0x7f;
478 :
479 0 : a->pbn = buf[++idx] << 8;
480 0 : a->pbn |= buf[++idx];
481 :
482 0 : idx++;
483 0 : for (i = 0; i < a->number_sdp_streams; i++) {
484 0 : a->sdp_stream_sink[i] =
485 0 : (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf;
486 : }
487 : }
488 : break;
489 : case DP_QUERY_PAYLOAD:
490 0 : req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf;
491 0 : WARN_ON(buf[++idx] & 0x80);
492 0 : req->u.query_payload.vcpi = buf[idx] & 0x7f;
493 0 : break;
494 : case DP_REMOTE_DPCD_READ:
495 : {
496 0 : struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read;
497 :
498 0 : r->port_number = (buf[idx] >> 4) & 0xf;
499 :
500 0 : r->dpcd_address = (buf[idx] << 16) & 0xf0000;
501 0 : r->dpcd_address |= (buf[++idx] << 8) & 0xff00;
502 0 : r->dpcd_address |= buf[++idx] & 0xff;
503 :
504 0 : r->num_bytes = buf[++idx];
505 : }
506 0 : break;
507 : case DP_REMOTE_DPCD_WRITE:
508 : {
509 0 : struct drm_dp_remote_dpcd_write *w =
510 : &req->u.dpcd_write;
511 :
512 0 : w->port_number = (buf[idx] >> 4) & 0xf;
513 :
514 0 : w->dpcd_address = (buf[idx] << 16) & 0xf0000;
515 0 : w->dpcd_address |= (buf[++idx] << 8) & 0xff00;
516 0 : w->dpcd_address |= buf[++idx] & 0xff;
517 :
518 0 : w->num_bytes = buf[++idx];
519 :
520 0 : w->bytes = kmemdup(&buf[++idx], w->num_bytes,
521 : GFP_KERNEL);
522 0 : if (!w->bytes)
523 : return -ENOMEM;
524 : }
525 : break;
526 : case DP_REMOTE_I2C_READ:
527 : {
528 0 : struct drm_dp_remote_i2c_read *r = &req->u.i2c_read;
529 : struct drm_dp_remote_i2c_read_tx *tx;
530 0 : bool failed = false;
531 :
532 0 : r->num_transactions = buf[idx] & 0x3;
533 0 : r->port_number = (buf[idx] >> 4) & 0xf;
534 0 : for (i = 0; i < r->num_transactions; i++) {
535 0 : tx = &r->transactions[i];
536 :
537 0 : tx->i2c_dev_id = buf[++idx] & 0x7f;
538 0 : tx->num_bytes = buf[++idx];
539 0 : tx->bytes = kmemdup(&buf[++idx],
540 : tx->num_bytes,
541 : GFP_KERNEL);
542 0 : if (!tx->bytes) {
543 : failed = true;
544 : break;
545 : }
546 0 : idx += tx->num_bytes;
547 0 : tx->no_stop_bit = (buf[idx] >> 5) & 0x1;
548 0 : tx->i2c_transaction_delay = buf[idx] & 0xf;
549 : }
550 :
551 0 : 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 0 : r->read_i2c_device_id = buf[++idx] & 0x7f;
560 0 : r->num_bytes_read = buf[++idx];
561 : }
562 0 : break;
563 : case DP_REMOTE_I2C_WRITE:
564 : {
565 0 : struct drm_dp_remote_i2c_write *w = &req->u.i2c_write;
566 :
567 0 : w->port_number = (buf[idx] >> 4) & 0xf;
568 0 : w->write_i2c_device_id = buf[++idx] & 0x7f;
569 0 : w->num_bytes = buf[++idx];
570 0 : w->bytes = kmemdup(&buf[++idx], w->num_bytes,
571 : GFP_KERNEL);
572 0 : if (!w->bytes)
573 : return -ENOMEM;
574 : }
575 : break;
576 : case DP_QUERY_STREAM_ENC_STATUS:
577 0 : req->u.enc_status.stream_id = buf[idx++];
578 0 : for (i = 0; i < sizeof(req->u.enc_status.client_id); i++)
579 0 : req->u.enc_status.client_id[i] = buf[idx++];
580 :
581 0 : req->u.enc_status.stream_event = FIELD_GET(GENMASK(1, 0),
582 : buf[idx]);
583 0 : req->u.enc_status.valid_stream_event = FIELD_GET(BIT(2),
584 : buf[idx]);
585 0 : req->u.enc_status.stream_behavior = FIELD_GET(GENMASK(4, 3),
586 : buf[idx]);
587 0 : req->u.enc_status.valid_stream_behavior = FIELD_GET(BIT(5),
588 : buf[idx]);
589 0 : 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 0 : static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1238 : struct drm_dp_vcpi *vcpi)
1239 : {
1240 : int ret, vcpi_ret;
1241 :
1242 0 : mutex_lock(&mgr->payload_lock);
1243 0 : ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
1244 0 : if (ret > mgr->max_payloads) {
1245 0 : ret = -EINVAL;
1246 0 : drm_dbg_kms(mgr->dev, "out of payload ids %d\n", ret);
1247 0 : goto out_unlock;
1248 : }
1249 :
1250 0 : vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
1251 0 : if (vcpi_ret > mgr->max_payloads) {
1252 0 : ret = -EINVAL;
1253 0 : drm_dbg_kms(mgr->dev, "out of vcpi ids %d\n", ret);
1254 0 : goto out_unlock;
1255 : }
1256 :
1257 0 : set_bit(ret, &mgr->payload_mask);
1258 0 : set_bit(vcpi_ret, &mgr->vcpi_mask);
1259 0 : vcpi->vcpi = vcpi_ret + 1;
1260 0 : mgr->proposed_vcpis[ret - 1] = vcpi;
1261 : out_unlock:
1262 0 : mutex_unlock(&mgr->payload_lock);
1263 0 : return ret;
1264 : }
1265 :
1266 0 : static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1267 : int vcpi)
1268 : {
1269 : int i;
1270 :
1271 0 : if (vcpi == 0)
1272 : return;
1273 :
1274 0 : mutex_lock(&mgr->payload_lock);
1275 0 : drm_dbg_kms(mgr->dev, "putting payload %d\n", vcpi);
1276 0 : clear_bit(vcpi - 1, &mgr->vcpi_mask);
1277 :
1278 0 : for (i = 0; i < mgr->max_payloads; i++) {
1279 0 : if (mgr->proposed_vcpis[i] &&
1280 0 : mgr->proposed_vcpis[i]->vcpi == vcpi) {
1281 0 : mgr->proposed_vcpis[i] = NULL;
1282 0 : clear_bit(i + 1, &mgr->payload_mask);
1283 : }
1284 : }
1285 0 : mutex_unlock(&mgr->payload_lock);
1286 : }
1287 :
1288 : static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
1289 : struct drm_dp_sideband_msg_tx *txmsg)
1290 : {
1291 : unsigned int state;
1292 :
1293 : /*
1294 : * All updates to txmsg->state are protected by mgr->qlock, and the two
1295 : * cases we check here are terminal states. For those the barriers
1296 : * provided by the wake_up/wait_event pair are enough.
1297 : */
1298 0 : state = READ_ONCE(txmsg->state);
1299 0 : return (state == DRM_DP_SIDEBAND_TX_RX ||
1300 : state == DRM_DP_SIDEBAND_TX_TIMEOUT);
1301 : }
1302 :
1303 0 : static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
1304 : struct drm_dp_sideband_msg_tx *txmsg)
1305 : {
1306 0 : struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1307 0 : unsigned long wait_timeout = msecs_to_jiffies(4000);
1308 0 : unsigned long wait_expires = jiffies + wait_timeout;
1309 : int ret;
1310 :
1311 : for (;;) {
1312 : /*
1313 : * If the driver provides a way for this, change to
1314 : * poll-waiting for the MST reply interrupt if we didn't receive
1315 : * it for 50 msec. This would cater for cases where the HPD
1316 : * pulse signal got lost somewhere, even though the sink raised
1317 : * the corresponding MST interrupt correctly. One example is the
1318 : * Club 3D CAC-1557 TypeC -> DP adapter which for some reason
1319 : * filters out short pulses with a duration less than ~540 usec.
1320 : *
1321 : * The poll period is 50 msec to avoid missing an interrupt
1322 : * after the sink has cleared it (after a 110msec timeout
1323 : * since it raised the interrupt).
1324 : */
1325 0 : ret = wait_event_timeout(mgr->tx_waitq,
1326 : check_txmsg_state(mgr, txmsg),
1327 : mgr->cbs->poll_hpd_irq ?
1328 : msecs_to_jiffies(50) :
1329 : wait_timeout);
1330 :
1331 0 : if (ret || !mgr->cbs->poll_hpd_irq ||
1332 0 : time_after(jiffies, wait_expires))
1333 : break;
1334 :
1335 0 : mgr->cbs->poll_hpd_irq(mgr);
1336 : }
1337 :
1338 0 : mutex_lock(&mgr->qlock);
1339 0 : if (ret > 0) {
1340 0 : if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
1341 0 : ret = -EIO;
1342 : goto out;
1343 : }
1344 : } else {
1345 0 : drm_dbg_kms(mgr->dev, "timedout msg send %p %d %d\n",
1346 : txmsg, txmsg->state, txmsg->seqno);
1347 :
1348 : /* dump some state */
1349 0 : ret = -EIO;
1350 :
1351 : /* remove from q */
1352 0 : if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
1353 0 : txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
1354 : txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
1355 0 : list_del(&txmsg->next);
1356 : }
1357 : out:
1358 0 : if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
1359 0 : struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1360 :
1361 0 : drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
1362 : }
1363 0 : mutex_unlock(&mgr->qlock);
1364 :
1365 0 : drm_dp_mst_kick_tx(mgr);
1366 0 : return ret;
1367 : }
1368 :
1369 0 : static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
1370 : {
1371 : struct drm_dp_mst_branch *mstb;
1372 :
1373 0 : mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
1374 0 : if (!mstb)
1375 : return NULL;
1376 :
1377 0 : mstb->lct = lct;
1378 0 : if (lct > 1)
1379 0 : memcpy(mstb->rad, rad, lct / 2);
1380 0 : INIT_LIST_HEAD(&mstb->ports);
1381 0 : kref_init(&mstb->topology_kref);
1382 0 : kref_init(&mstb->malloc_kref);
1383 0 : return mstb;
1384 : }
1385 :
1386 0 : static void drm_dp_free_mst_branch_device(struct kref *kref)
1387 : {
1388 0 : struct drm_dp_mst_branch *mstb =
1389 0 : container_of(kref, struct drm_dp_mst_branch, malloc_kref);
1390 :
1391 0 : if (mstb->port_parent)
1392 0 : drm_dp_mst_put_port_malloc(mstb->port_parent);
1393 :
1394 0 : kfree(mstb);
1395 0 : }
1396 :
1397 : /**
1398 : * DOC: Branch device and port refcounting
1399 : *
1400 : * Topology refcount overview
1401 : * ~~~~~~~~~~~~~~~~~~~~~~~~~~
1402 : *
1403 : * The refcounting schemes for &struct drm_dp_mst_branch and &struct
1404 : * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
1405 : * two different kinds of refcounts: topology refcounts, and malloc refcounts.
1406 : *
1407 : * Topology refcounts are not exposed to drivers, and are handled internally
1408 : * by the DP MST helpers. The helpers use them in order to prevent the
1409 : * in-memory topology state from being changed in the middle of critical
1410 : * operations like changing the internal state of payload allocations. This
1411 : * means each branch and port will be considered to be connected to the rest
1412 : * of the topology until its topology refcount reaches zero. Additionally,
1413 : * for ports this means that their associated &struct drm_connector will stay
1414 : * registered with userspace until the port's refcount reaches 0.
1415 : *
1416 : * Malloc refcount overview
1417 : * ~~~~~~~~~~~~~~~~~~~~~~~~
1418 : *
1419 : * Malloc references are used to keep a &struct drm_dp_mst_port or &struct
1420 : * drm_dp_mst_branch allocated even after all of its topology references have
1421 : * been dropped, so that the driver or MST helpers can safely access each
1422 : * branch's last known state before it was disconnected from the topology.
1423 : * When the malloc refcount of a port or branch reaches 0, the memory
1424 : * allocation containing the &struct drm_dp_mst_branch or &struct
1425 : * drm_dp_mst_port respectively will be freed.
1426 : *
1427 : * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
1428 : * to drivers. As of writing this documentation, there are no drivers that
1429 : * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
1430 : * helpers. Exposing this API to drivers in a race-free manner would take more
1431 : * tweaking of the refcounting scheme, however patches are welcome provided
1432 : * there is a legitimate driver usecase for this.
1433 : *
1434 : * Refcount relationships in a topology
1435 : * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1436 : *
1437 : * Let's take a look at why the relationship between topology and malloc
1438 : * refcounts is designed the way it is.
1439 : *
1440 : * .. kernel-figure:: dp-mst/topology-figure-1.dot
1441 : *
1442 : * An example of topology and malloc refs in a DP MST topology with two
1443 : * active payloads. Topology refcount increments are indicated by solid
1444 : * lines, and malloc refcount increments are indicated by dashed lines.
1445 : * Each starts from the branch which incremented the refcount, and ends at
1446 : * the branch to which the refcount belongs to, i.e. the arrow points the
1447 : * same way as the C pointers used to reference a structure.
1448 : *
1449 : * As you can see in the above figure, every branch increments the topology
1450 : * refcount of its children, and increments the malloc refcount of its
1451 : * parent. Additionally, every payload increments the malloc refcount of its
1452 : * assigned port by 1.
1453 : *
1454 : * So, what would happen if MSTB #3 from the above figure was unplugged from
1455 : * the system, but the driver hadn't yet removed payload #2 from port #3? The
1456 : * topology would start to look like the figure below.
1457 : *
1458 : * .. kernel-figure:: dp-mst/topology-figure-2.dot
1459 : *
1460 : * Ports and branch devices which have been released from memory are
1461 : * colored grey, and references which have been removed are colored red.
1462 : *
1463 : * Whenever a port or branch device's topology refcount reaches zero, it will
1464 : * decrement the topology refcounts of all its children, the malloc refcount
1465 : * of its parent, and finally its own malloc refcount. For MSTB #4 and port
1466 : * #4, this means they both have been disconnected from the topology and freed
1467 : * from memory. But, because payload #2 is still holding a reference to port
1468 : * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
1469 : * is still accessible from memory. This also means port #3 has not yet
1470 : * decremented the malloc refcount of MSTB #3, so its &struct
1471 : * drm_dp_mst_branch will also stay allocated in memory until port #3's
1472 : * malloc refcount reaches 0.
1473 : *
1474 : * This relationship is necessary because in order to release payload #2, we
1475 : * need to be able to figure out the last relative of port #3 that's still
1476 : * connected to the topology. In this case, we would travel up the topology as
1477 : * shown below.
1478 : *
1479 : * .. kernel-figure:: dp-mst/topology-figure-3.dot
1480 : *
1481 : * And finally, remove payload #2 by communicating with port #2 through
1482 : * sideband transactions.
1483 : */
1484 :
1485 : /**
1486 : * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
1487 : * device
1488 : * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
1489 : *
1490 : * Increments &drm_dp_mst_branch.malloc_kref. When
1491 : * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1492 : * will be released and @mstb may no longer be used.
1493 : *
1494 : * See also: drm_dp_mst_put_mstb_malloc()
1495 : */
1496 : static void
1497 0 : drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
1498 : {
1499 0 : kref_get(&mstb->malloc_kref);
1500 0 : drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
1501 0 : }
1502 :
1503 : /**
1504 : * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
1505 : * device
1506 : * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
1507 : *
1508 : * Decrements &drm_dp_mst_branch.malloc_kref. When
1509 : * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1510 : * will be released and @mstb may no longer be used.
1511 : *
1512 : * See also: drm_dp_mst_get_mstb_malloc()
1513 : */
1514 : static void
1515 0 : drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
1516 : {
1517 0 : drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
1518 0 : kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
1519 0 : }
1520 :
1521 0 : static void drm_dp_free_mst_port(struct kref *kref)
1522 : {
1523 0 : struct drm_dp_mst_port *port =
1524 0 : container_of(kref, struct drm_dp_mst_port, malloc_kref);
1525 :
1526 0 : drm_dp_mst_put_mstb_malloc(port->parent);
1527 0 : kfree(port);
1528 0 : }
1529 :
1530 : /**
1531 : * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
1532 : * @port: The &struct drm_dp_mst_port to increment the malloc refcount of
1533 : *
1534 : * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1535 : * reaches 0, the memory allocation for @port will be released and @port may
1536 : * no longer be used.
1537 : *
1538 : * Because @port could potentially be freed at any time by the DP MST helpers
1539 : * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
1540 : * function, drivers that which to make use of &struct drm_dp_mst_port should
1541 : * ensure that they grab at least one main malloc reference to their MST ports
1542 : * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
1543 : * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
1544 : *
1545 : * See also: drm_dp_mst_put_port_malloc()
1546 : */
1547 : void
1548 0 : drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
1549 : {
1550 0 : kref_get(&port->malloc_kref);
1551 0 : drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref));
1552 0 : }
1553 : EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
1554 :
1555 : /**
1556 : * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
1557 : * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
1558 : *
1559 : * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1560 : * reaches 0, the memory allocation for @port will be released and @port may
1561 : * no longer be used.
1562 : *
1563 : * See also: drm_dp_mst_get_port_malloc()
1564 : */
1565 : void
1566 0 : drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
1567 : {
1568 0 : drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
1569 0 : kref_put(&port->malloc_kref, drm_dp_free_mst_port);
1570 0 : }
1571 : EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
1572 :
1573 : #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
1574 :
1575 : #define STACK_DEPTH 8
1576 :
1577 : static noinline void
1578 : __topology_ref_save(struct drm_dp_mst_topology_mgr *mgr,
1579 : struct drm_dp_mst_topology_ref_history *history,
1580 : enum drm_dp_mst_topology_ref_type type)
1581 : {
1582 : struct drm_dp_mst_topology_ref_entry *entry = NULL;
1583 : depot_stack_handle_t backtrace;
1584 : ulong stack_entries[STACK_DEPTH];
1585 : uint n;
1586 : int i;
1587 :
1588 : n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1);
1589 : backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL);
1590 : if (!backtrace)
1591 : return;
1592 :
1593 : /* Try to find an existing entry for this backtrace */
1594 : for (i = 0; i < history->len; i++) {
1595 : if (history->entries[i].backtrace == backtrace) {
1596 : entry = &history->entries[i];
1597 : break;
1598 : }
1599 : }
1600 :
1601 : /* Otherwise add one */
1602 : if (!entry) {
1603 : struct drm_dp_mst_topology_ref_entry *new;
1604 : int new_len = history->len + 1;
1605 :
1606 : new = krealloc(history->entries, sizeof(*new) * new_len,
1607 : GFP_KERNEL);
1608 : if (!new)
1609 : return;
1610 :
1611 : entry = &new[history->len];
1612 : history->len = new_len;
1613 : history->entries = new;
1614 :
1615 : entry->backtrace = backtrace;
1616 : entry->type = type;
1617 : entry->count = 0;
1618 : }
1619 : entry->count++;
1620 : entry->ts_nsec = ktime_get_ns();
1621 : }
1622 :
1623 : static int
1624 : topology_ref_history_cmp(const void *a, const void *b)
1625 : {
1626 : const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b;
1627 :
1628 : if (entry_a->ts_nsec > entry_b->ts_nsec)
1629 : return 1;
1630 : else if (entry_a->ts_nsec < entry_b->ts_nsec)
1631 : return -1;
1632 : else
1633 : return 0;
1634 : }
1635 :
1636 : static inline const char *
1637 : topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type)
1638 : {
1639 : if (type == DRM_DP_MST_TOPOLOGY_REF_GET)
1640 : return "get";
1641 : else
1642 : return "put";
1643 : }
1644 :
1645 : static void
1646 : __dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history,
1647 : void *ptr, const char *type_str)
1648 : {
1649 : struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1650 : char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1651 : int i;
1652 :
1653 : if (!buf)
1654 : return;
1655 :
1656 : if (!history->len)
1657 : goto out;
1658 :
1659 : /* First, sort the list so that it goes from oldest to newest
1660 : * reference entry
1661 : */
1662 : sort(history->entries, history->len, sizeof(*history->entries),
1663 : topology_ref_history_cmp, NULL);
1664 :
1665 : drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n",
1666 : type_str, ptr);
1667 :
1668 : for (i = 0; i < history->len; i++) {
1669 : const struct drm_dp_mst_topology_ref_entry *entry =
1670 : &history->entries[i];
1671 : u64 ts_nsec = entry->ts_nsec;
1672 : u32 rem_nsec = do_div(ts_nsec, 1000000000);
1673 :
1674 : stack_depot_snprint(entry->backtrace, buf, PAGE_SIZE, 4);
1675 :
1676 : drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s",
1677 : entry->count,
1678 : topology_ref_type_to_str(entry->type),
1679 : ts_nsec, rem_nsec / 1000, buf);
1680 : }
1681 :
1682 : /* Now free the history, since this is the only time we expose it */
1683 : kfree(history->entries);
1684 : out:
1685 : kfree(buf);
1686 : }
1687 :
1688 : static __always_inline void
1689 : drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb)
1690 : {
1691 : __dump_topology_ref_history(&mstb->topology_ref_history, mstb,
1692 : "MSTB");
1693 : }
1694 :
1695 : static __always_inline void
1696 : drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port)
1697 : {
1698 : __dump_topology_ref_history(&port->topology_ref_history, port,
1699 : "Port");
1700 : }
1701 :
1702 : static __always_inline void
1703 : save_mstb_topology_ref(struct drm_dp_mst_branch *mstb,
1704 : enum drm_dp_mst_topology_ref_type type)
1705 : {
1706 : __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type);
1707 : }
1708 :
1709 : static __always_inline void
1710 : save_port_topology_ref(struct drm_dp_mst_port *port,
1711 : enum drm_dp_mst_topology_ref_type type)
1712 : {
1713 : __topology_ref_save(port->mgr, &port->topology_ref_history, type);
1714 : }
1715 :
1716 : static inline void
1717 : topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr)
1718 : {
1719 : mutex_lock(&mgr->topology_ref_history_lock);
1720 : }
1721 :
1722 : static inline void
1723 : topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr)
1724 : {
1725 : mutex_unlock(&mgr->topology_ref_history_lock);
1726 : }
1727 : #else
1728 : static inline void
1729 : topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {}
1730 : static inline void
1731 : topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {}
1732 : static inline void
1733 : drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {}
1734 : static inline void
1735 : drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {}
1736 : #define save_mstb_topology_ref(mstb, type)
1737 : #define save_port_topology_ref(port, type)
1738 : #endif
1739 :
1740 0 : static void drm_dp_destroy_mst_branch_device(struct kref *kref)
1741 : {
1742 0 : struct drm_dp_mst_branch *mstb =
1743 0 : container_of(kref, struct drm_dp_mst_branch, topology_kref);
1744 0 : struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1745 :
1746 0 : drm_dp_mst_dump_mstb_topology_history(mstb);
1747 :
1748 0 : INIT_LIST_HEAD(&mstb->destroy_next);
1749 :
1750 : /*
1751 : * This can get called under mgr->mutex, so we need to perform the
1752 : * actual destruction of the mstb in another worker
1753 : */
1754 0 : mutex_lock(&mgr->delayed_destroy_lock);
1755 0 : list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list);
1756 0 : mutex_unlock(&mgr->delayed_destroy_lock);
1757 0 : queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1758 0 : }
1759 :
1760 : /**
1761 : * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1762 : * branch device unless it's zero
1763 : * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
1764 : *
1765 : * Attempts to grab a topology reference to @mstb, if it hasn't yet been
1766 : * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
1767 : * reached 0). Holding a topology reference implies that a malloc reference
1768 : * will be held to @mstb as long as the user holds the topology reference.
1769 : *
1770 : * Care should be taken to ensure that the user has at least one malloc
1771 : * reference to @mstb. If you already have a topology reference to @mstb, you
1772 : * should use drm_dp_mst_topology_get_mstb() instead.
1773 : *
1774 : * See also:
1775 : * drm_dp_mst_topology_get_mstb()
1776 : * drm_dp_mst_topology_put_mstb()
1777 : *
1778 : * Returns:
1779 : * * 1: A topology reference was grabbed successfully
1780 : * * 0: @port is no longer in the topology, no reference was grabbed
1781 : */
1782 : static int __must_check
1783 0 : drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
1784 : {
1785 : int ret;
1786 :
1787 0 : topology_ref_history_lock(mstb->mgr);
1788 0 : ret = kref_get_unless_zero(&mstb->topology_kref);
1789 0 : if (ret) {
1790 0 : drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1791 : save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1792 : }
1793 :
1794 0 : topology_ref_history_unlock(mstb->mgr);
1795 :
1796 0 : return ret;
1797 : }
1798 :
1799 : /**
1800 : * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
1801 : * branch device
1802 : * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
1803 : *
1804 : * Increments &drm_dp_mst_branch.topology_refcount without checking whether or
1805 : * not it's already reached 0. This is only valid to use in scenarios where
1806 : * you are already guaranteed to have at least one active topology reference
1807 : * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
1808 : *
1809 : * See also:
1810 : * drm_dp_mst_topology_try_get_mstb()
1811 : * drm_dp_mst_topology_put_mstb()
1812 : */
1813 0 : static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
1814 : {
1815 0 : topology_ref_history_lock(mstb->mgr);
1816 :
1817 : save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1818 0 : WARN_ON(kref_read(&mstb->topology_kref) == 0);
1819 0 : kref_get(&mstb->topology_kref);
1820 0 : drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1821 :
1822 0 : topology_ref_history_unlock(mstb->mgr);
1823 0 : }
1824 :
1825 : /**
1826 : * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
1827 : * device
1828 : * @mstb: The &struct drm_dp_mst_branch to release the topology reference from
1829 : *
1830 : * Releases a topology reference from @mstb by decrementing
1831 : * &drm_dp_mst_branch.topology_kref.
1832 : *
1833 : * See also:
1834 : * drm_dp_mst_topology_try_get_mstb()
1835 : * drm_dp_mst_topology_get_mstb()
1836 : */
1837 : static void
1838 0 : drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
1839 : {
1840 0 : topology_ref_history_lock(mstb->mgr);
1841 :
1842 0 : drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref) - 1);
1843 : save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT);
1844 :
1845 0 : topology_ref_history_unlock(mstb->mgr);
1846 0 : kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
1847 0 : }
1848 :
1849 0 : static void drm_dp_destroy_port(struct kref *kref)
1850 : {
1851 0 : struct drm_dp_mst_port *port =
1852 0 : container_of(kref, struct drm_dp_mst_port, topology_kref);
1853 0 : struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1854 :
1855 0 : drm_dp_mst_dump_port_topology_history(port);
1856 :
1857 : /* There's nothing that needs locking to destroy an input port yet */
1858 0 : if (port->input) {
1859 0 : drm_dp_mst_put_port_malloc(port);
1860 0 : return;
1861 : }
1862 :
1863 0 : kfree(port->cached_edid);
1864 :
1865 : /*
1866 : * we can't destroy the connector here, as we might be holding the
1867 : * mode_config.mutex from an EDID retrieval
1868 : */
1869 0 : mutex_lock(&mgr->delayed_destroy_lock);
1870 0 : list_add(&port->next, &mgr->destroy_port_list);
1871 0 : mutex_unlock(&mgr->delayed_destroy_lock);
1872 0 : queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1873 : }
1874 :
1875 : /**
1876 : * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
1877 : * port unless it's zero
1878 : * @port: &struct drm_dp_mst_port to increment the topology refcount of
1879 : *
1880 : * Attempts to grab a topology reference to @port, if it hasn't yet been
1881 : * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
1882 : * 0). Holding a topology reference implies that a malloc reference will be
1883 : * held to @port as long as the user holds the topology reference.
1884 : *
1885 : * Care should be taken to ensure that the user has at least one malloc
1886 : * reference to @port. If you already have a topology reference to @port, you
1887 : * should use drm_dp_mst_topology_get_port() instead.
1888 : *
1889 : * See also:
1890 : * drm_dp_mst_topology_get_port()
1891 : * drm_dp_mst_topology_put_port()
1892 : *
1893 : * Returns:
1894 : * * 1: A topology reference was grabbed successfully
1895 : * * 0: @port is no longer in the topology, no reference was grabbed
1896 : */
1897 : static int __must_check
1898 0 : drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
1899 : {
1900 : int ret;
1901 :
1902 0 : topology_ref_history_lock(port->mgr);
1903 0 : ret = kref_get_unless_zero(&port->topology_kref);
1904 0 : if (ret) {
1905 0 : drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref));
1906 : save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1907 : }
1908 :
1909 0 : topology_ref_history_unlock(port->mgr);
1910 0 : return ret;
1911 : }
1912 :
1913 : /**
1914 : * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
1915 : * @port: The &struct drm_dp_mst_port to increment the topology refcount of
1916 : *
1917 : * Increments &drm_dp_mst_port.topology_refcount without checking whether or
1918 : * not it's already reached 0. This is only valid to use in scenarios where
1919 : * you are already guaranteed to have at least one active topology reference
1920 : * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
1921 : *
1922 : * See also:
1923 : * drm_dp_mst_topology_try_get_port()
1924 : * drm_dp_mst_topology_put_port()
1925 : */
1926 0 : static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
1927 : {
1928 0 : topology_ref_history_lock(port->mgr);
1929 :
1930 0 : WARN_ON(kref_read(&port->topology_kref) == 0);
1931 0 : kref_get(&port->topology_kref);
1932 0 : drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref));
1933 : save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1934 :
1935 0 : topology_ref_history_unlock(port->mgr);
1936 0 : }
1937 :
1938 : /**
1939 : * drm_dp_mst_topology_put_port() - release a topology reference to a port
1940 : * @port: The &struct drm_dp_mst_port to release the topology reference from
1941 : *
1942 : * Releases a topology reference from @port by decrementing
1943 : * &drm_dp_mst_port.topology_kref.
1944 : *
1945 : * See also:
1946 : * drm_dp_mst_topology_try_get_port()
1947 : * drm_dp_mst_topology_get_port()
1948 : */
1949 0 : static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
1950 : {
1951 0 : topology_ref_history_lock(port->mgr);
1952 :
1953 0 : drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref) - 1);
1954 : save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT);
1955 :
1956 0 : topology_ref_history_unlock(port->mgr);
1957 0 : kref_put(&port->topology_kref, drm_dp_destroy_port);
1958 0 : }
1959 :
1960 : static struct drm_dp_mst_branch *
1961 0 : drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
1962 : struct drm_dp_mst_branch *to_find)
1963 : {
1964 : struct drm_dp_mst_port *port;
1965 : struct drm_dp_mst_branch *rmstb;
1966 :
1967 0 : if (to_find == mstb)
1968 : return mstb;
1969 :
1970 0 : list_for_each_entry(port, &mstb->ports, next) {
1971 0 : if (port->mstb) {
1972 0 : rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1973 : port->mstb, to_find);
1974 0 : if (rmstb)
1975 : return rmstb;
1976 : }
1977 : }
1978 : return NULL;
1979 : }
1980 :
1981 : static struct drm_dp_mst_branch *
1982 0 : drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
1983 : struct drm_dp_mst_branch *mstb)
1984 : {
1985 0 : struct drm_dp_mst_branch *rmstb = NULL;
1986 :
1987 0 : mutex_lock(&mgr->lock);
1988 0 : if (mgr->mst_primary) {
1989 0 : rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1990 : mgr->mst_primary, mstb);
1991 :
1992 0 : if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
1993 0 : rmstb = NULL;
1994 : }
1995 0 : mutex_unlock(&mgr->lock);
1996 0 : return rmstb;
1997 : }
1998 :
1999 : static struct drm_dp_mst_port *
2000 0 : drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
2001 : struct drm_dp_mst_port *to_find)
2002 : {
2003 : struct drm_dp_mst_port *port, *mport;
2004 :
2005 0 : list_for_each_entry(port, &mstb->ports, next) {
2006 0 : if (port == to_find)
2007 : return port;
2008 :
2009 0 : if (port->mstb) {
2010 0 : mport = drm_dp_mst_topology_get_port_validated_locked(
2011 : port->mstb, to_find);
2012 0 : if (mport)
2013 : return mport;
2014 : }
2015 : }
2016 : return NULL;
2017 : }
2018 :
2019 : static struct drm_dp_mst_port *
2020 0 : drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
2021 : struct drm_dp_mst_port *port)
2022 : {
2023 0 : struct drm_dp_mst_port *rport = NULL;
2024 :
2025 0 : mutex_lock(&mgr->lock);
2026 0 : if (mgr->mst_primary) {
2027 0 : rport = drm_dp_mst_topology_get_port_validated_locked(
2028 : mgr->mst_primary, port);
2029 :
2030 0 : if (rport && !drm_dp_mst_topology_try_get_port(rport))
2031 0 : rport = NULL;
2032 : }
2033 0 : mutex_unlock(&mgr->lock);
2034 0 : return rport;
2035 : }
2036 :
2037 0 : static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
2038 : {
2039 : struct drm_dp_mst_port *port;
2040 : int ret;
2041 :
2042 0 : list_for_each_entry(port, &mstb->ports, next) {
2043 0 : if (port->port_num == port_num) {
2044 0 : ret = drm_dp_mst_topology_try_get_port(port);
2045 0 : return ret ? port : NULL;
2046 : }
2047 : }
2048 :
2049 : return NULL;
2050 : }
2051 :
2052 : /*
2053 : * calculate a new RAD for this MST branch device
2054 : * if parent has an LCT of 2 then it has 1 nibble of RAD,
2055 : * if parent has an LCT of 3 then it has 2 nibbles of RAD,
2056 : */
2057 0 : static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
2058 : u8 *rad)
2059 : {
2060 0 : int parent_lct = port->parent->lct;
2061 0 : int shift = 4;
2062 0 : int idx = (parent_lct - 1) / 2;
2063 :
2064 0 : if (parent_lct > 1) {
2065 0 : memcpy(rad, port->parent->rad, idx + 1);
2066 0 : shift = (parent_lct % 2) ? 4 : 0;
2067 : } else
2068 0 : rad[0] = 0;
2069 :
2070 0 : rad[idx] |= port->port_num << shift;
2071 0 : return parent_lct + 1;
2072 : }
2073 :
2074 : static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs)
2075 : {
2076 0 : switch (pdt) {
2077 : case DP_PEER_DEVICE_DP_LEGACY_CONV:
2078 : case DP_PEER_DEVICE_SST_SINK:
2079 : return true;
2080 : case DP_PEER_DEVICE_MST_BRANCHING:
2081 : /* For sst branch device */
2082 0 : if (!mcs)
2083 : return true;
2084 :
2085 : return false;
2086 : }
2087 : return true;
2088 : }
2089 :
2090 : static int
2091 0 : drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
2092 : bool new_mcs)
2093 : {
2094 0 : struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2095 : struct drm_dp_mst_branch *mstb;
2096 : u8 rad[8], lct;
2097 0 : int ret = 0;
2098 :
2099 0 : if (port->pdt == new_pdt && port->mcs == new_mcs)
2100 : return 0;
2101 :
2102 : /* Teardown the old pdt, if there is one */
2103 0 : if (port->pdt != DP_PEER_DEVICE_NONE) {
2104 0 : if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2105 : /*
2106 : * If the new PDT would also have an i2c bus,
2107 : * don't bother with reregistering it
2108 : */
2109 0 : if (new_pdt != DP_PEER_DEVICE_NONE &&
2110 0 : drm_dp_mst_is_end_device(new_pdt, new_mcs)) {
2111 0 : port->pdt = new_pdt;
2112 0 : port->mcs = new_mcs;
2113 0 : return 0;
2114 : }
2115 :
2116 : /* remove i2c over sideband */
2117 : drm_dp_mst_unregister_i2c_bus(port);
2118 : } else {
2119 0 : mutex_lock(&mgr->lock);
2120 0 : drm_dp_mst_topology_put_mstb(port->mstb);
2121 0 : port->mstb = NULL;
2122 0 : mutex_unlock(&mgr->lock);
2123 : }
2124 : }
2125 :
2126 0 : port->pdt = new_pdt;
2127 0 : port->mcs = new_mcs;
2128 :
2129 0 : if (port->pdt != DP_PEER_DEVICE_NONE) {
2130 0 : if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2131 : /* add i2c over sideband */
2132 0 : ret = drm_dp_mst_register_i2c_bus(port);
2133 : } else {
2134 0 : lct = drm_dp_calculate_rad(port, rad);
2135 0 : mstb = drm_dp_add_mst_branch_device(lct, rad);
2136 0 : if (!mstb) {
2137 0 : ret = -ENOMEM;
2138 0 : drm_err(mgr->dev, "Failed to create MSTB for port %p", port);
2139 0 : goto out;
2140 : }
2141 :
2142 0 : mutex_lock(&mgr->lock);
2143 0 : port->mstb = mstb;
2144 0 : mstb->mgr = port->mgr;
2145 0 : mstb->port_parent = port;
2146 :
2147 : /*
2148 : * Make sure this port's memory allocation stays
2149 : * around until its child MSTB releases it
2150 : */
2151 0 : drm_dp_mst_get_port_malloc(port);
2152 0 : mutex_unlock(&mgr->lock);
2153 :
2154 : /* And make sure we send a link address for this */
2155 0 : ret = 1;
2156 : }
2157 : }
2158 :
2159 : out:
2160 0 : if (ret < 0)
2161 0 : port->pdt = DP_PEER_DEVICE_NONE;
2162 : return ret;
2163 : }
2164 :
2165 : /**
2166 : * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
2167 : * @aux: Fake sideband AUX CH
2168 : * @offset: address of the (first) register to read
2169 : * @buffer: buffer to store the register values
2170 : * @size: number of bytes in @buffer
2171 : *
2172 : * Performs the same functionality for remote devices via
2173 : * sideband messaging as drm_dp_dpcd_read() does for local
2174 : * devices via actual AUX CH.
2175 : *
2176 : * Return: Number of bytes read, or negative error code on failure.
2177 : */
2178 0 : ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
2179 : unsigned int offset, void *buffer, size_t size)
2180 : {
2181 0 : struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2182 : aux);
2183 :
2184 0 : return drm_dp_send_dpcd_read(port->mgr, port,
2185 : offset, size, buffer);
2186 : }
2187 :
2188 : /**
2189 : * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
2190 : * @aux: Fake sideband AUX CH
2191 : * @offset: address of the (first) register to write
2192 : * @buffer: buffer containing the values to write
2193 : * @size: number of bytes in @buffer
2194 : *
2195 : * Performs the same functionality for remote devices via
2196 : * sideband messaging as drm_dp_dpcd_write() does for local
2197 : * devices via actual AUX CH.
2198 : *
2199 : * Return: number of bytes written on success, negative error code on failure.
2200 : */
2201 0 : ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
2202 : unsigned int offset, void *buffer, size_t size)
2203 : {
2204 0 : struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2205 : aux);
2206 :
2207 0 : return drm_dp_send_dpcd_write(port->mgr, port,
2208 : offset, size, buffer);
2209 : }
2210 :
2211 0 : static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
2212 : {
2213 0 : int ret = 0;
2214 :
2215 0 : memcpy(mstb->guid, guid, 16);
2216 :
2217 0 : if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
2218 0 : if (mstb->port_parent) {
2219 0 : ret = drm_dp_send_dpcd_write(mstb->mgr,
2220 : mstb->port_parent,
2221 : DP_GUID, 16, mstb->guid);
2222 : } else {
2223 0 : ret = drm_dp_dpcd_write(mstb->mgr->aux,
2224 : DP_GUID, mstb->guid, 16);
2225 : }
2226 : }
2227 :
2228 0 : if (ret < 16 && ret > 0)
2229 : return -EPROTO;
2230 :
2231 0 : return ret == 16 ? 0 : ret;
2232 : }
2233 :
2234 0 : static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
2235 : int pnum,
2236 : char *proppath,
2237 : size_t proppath_size)
2238 : {
2239 : int i;
2240 : char temp[8];
2241 :
2242 0 : snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
2243 0 : for (i = 0; i < (mstb->lct - 1); i++) {
2244 0 : int shift = (i % 2) ? 0 : 4;
2245 0 : int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
2246 :
2247 0 : snprintf(temp, sizeof(temp), "-%d", port_num);
2248 0 : strlcat(proppath, temp, proppath_size);
2249 : }
2250 0 : snprintf(temp, sizeof(temp), "-%d", pnum);
2251 0 : strlcat(proppath, temp, proppath_size);
2252 0 : }
2253 :
2254 : /**
2255 : * drm_dp_mst_connector_late_register() - Late MST connector registration
2256 : * @connector: The MST connector
2257 : * @port: The MST port for this connector
2258 : *
2259 : * Helper to register the remote aux device for this MST port. Drivers should
2260 : * call this from their mst connector's late_register hook to enable MST aux
2261 : * devices.
2262 : *
2263 : * Return: 0 on success, negative error code on failure.
2264 : */
2265 0 : int drm_dp_mst_connector_late_register(struct drm_connector *connector,
2266 : struct drm_dp_mst_port *port)
2267 : {
2268 0 : drm_dbg_kms(port->mgr->dev, "registering %s remote bus for %s\n",
2269 : port->aux.name, connector->kdev->kobj.name);
2270 :
2271 0 : port->aux.dev = connector->kdev;
2272 0 : return drm_dp_aux_register_devnode(&port->aux);
2273 : }
2274 : EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
2275 :
2276 : /**
2277 : * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
2278 : * @connector: The MST connector
2279 : * @port: The MST port for this connector
2280 : *
2281 : * Helper to unregister the remote aux device for this MST port, registered by
2282 : * drm_dp_mst_connector_late_register(). Drivers should call this from their mst
2283 : * connector's early_unregister hook.
2284 : */
2285 0 : void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
2286 : struct drm_dp_mst_port *port)
2287 : {
2288 0 : drm_dbg_kms(port->mgr->dev, "unregistering %s remote bus for %s\n",
2289 : port->aux.name, connector->kdev->kobj.name);
2290 0 : drm_dp_aux_unregister_devnode(&port->aux);
2291 0 : }
2292 : EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
2293 :
2294 : static void
2295 0 : drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
2296 : struct drm_dp_mst_port *port)
2297 : {
2298 0 : struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2299 : char proppath[255];
2300 : int ret;
2301 :
2302 0 : build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
2303 0 : port->connector = mgr->cbs->add_connector(mgr, port, proppath);
2304 0 : if (!port->connector) {
2305 0 : ret = -ENOMEM;
2306 : goto error;
2307 : }
2308 :
2309 0 : if (port->pdt != DP_PEER_DEVICE_NONE &&
2310 0 : drm_dp_mst_is_end_device(port->pdt, port->mcs) &&
2311 0 : port->port_num >= DP_MST_LOGICAL_PORT_0)
2312 0 : port->cached_edid = drm_get_edid(port->connector,
2313 : &port->aux.ddc);
2314 :
2315 0 : drm_connector_register(port->connector);
2316 0 : return;
2317 :
2318 : error:
2319 0 : drm_err(mgr->dev, "Failed to create connector for port %p: %d\n", port, ret);
2320 : }
2321 :
2322 : /*
2323 : * Drop a topology reference, and unlink the port from the in-memory topology
2324 : * layout
2325 : */
2326 : static void
2327 0 : drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr,
2328 : struct drm_dp_mst_port *port)
2329 : {
2330 0 : mutex_lock(&mgr->lock);
2331 0 : port->parent->num_ports--;
2332 0 : list_del(&port->next);
2333 0 : mutex_unlock(&mgr->lock);
2334 0 : drm_dp_mst_topology_put_port(port);
2335 0 : }
2336 :
2337 : static struct drm_dp_mst_port *
2338 0 : drm_dp_mst_add_port(struct drm_device *dev,
2339 : struct drm_dp_mst_topology_mgr *mgr,
2340 : struct drm_dp_mst_branch *mstb, u8 port_number)
2341 : {
2342 0 : struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
2343 :
2344 0 : if (!port)
2345 : return NULL;
2346 :
2347 0 : kref_init(&port->topology_kref);
2348 0 : kref_init(&port->malloc_kref);
2349 0 : port->parent = mstb;
2350 0 : port->port_num = port_number;
2351 0 : port->mgr = mgr;
2352 0 : port->aux.name = "DPMST";
2353 0 : port->aux.dev = dev->dev;
2354 0 : port->aux.is_remote = true;
2355 :
2356 : /* initialize the MST downstream port's AUX crc work queue */
2357 0 : port->aux.drm_dev = dev;
2358 0 : drm_dp_remote_aux_init(&port->aux);
2359 :
2360 : /*
2361 : * Make sure the memory allocation for our parent branch stays
2362 : * around until our own memory allocation is released
2363 : */
2364 0 : drm_dp_mst_get_mstb_malloc(mstb);
2365 :
2366 0 : return port;
2367 : }
2368 :
2369 : static int
2370 0 : drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
2371 : struct drm_device *dev,
2372 : struct drm_dp_link_addr_reply_port *port_msg)
2373 : {
2374 0 : struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2375 : struct drm_dp_mst_port *port;
2376 0 : int old_ddps = 0, ret;
2377 0 : u8 new_pdt = DP_PEER_DEVICE_NONE;
2378 0 : bool new_mcs = 0;
2379 0 : bool created = false, send_link_addr = false, changed = false;
2380 :
2381 0 : port = drm_dp_get_port(mstb, port_msg->port_number);
2382 0 : if (!port) {
2383 0 : port = drm_dp_mst_add_port(dev, mgr, mstb,
2384 0 : port_msg->port_number);
2385 0 : if (!port)
2386 : return -ENOMEM;
2387 : created = true;
2388 : changed = true;
2389 0 : } else if (!port->input && port_msg->input_port && port->connector) {
2390 : /* Since port->connector can't be changed here, we create a
2391 : * new port if input_port changes from 0 to 1
2392 : */
2393 0 : drm_dp_mst_topology_unlink_port(mgr, port);
2394 0 : drm_dp_mst_topology_put_port(port);
2395 0 : port = drm_dp_mst_add_port(dev, mgr, mstb,
2396 0 : port_msg->port_number);
2397 0 : if (!port)
2398 : return -ENOMEM;
2399 : changed = true;
2400 : created = true;
2401 0 : } else if (port->input && !port_msg->input_port) {
2402 : changed = true;
2403 0 : } else if (port->connector) {
2404 : /* We're updating a port that's exposed to userspace, so do it
2405 : * under lock
2406 : */
2407 0 : drm_modeset_lock(&mgr->base.lock, NULL);
2408 :
2409 0 : old_ddps = port->ddps;
2410 0 : changed = port->ddps != port_msg->ddps ||
2411 0 : (port->ddps &&
2412 0 : (port->ldps != port_msg->legacy_device_plug_status ||
2413 0 : port->dpcd_rev != port_msg->dpcd_revision ||
2414 0 : port->mcs != port_msg->mcs ||
2415 0 : port->pdt != port_msg->peer_device_type ||
2416 0 : port->num_sdp_stream_sinks !=
2417 0 : port_msg->num_sdp_stream_sinks));
2418 : }
2419 :
2420 0 : port->input = port_msg->input_port;
2421 0 : if (!port->input)
2422 0 : new_pdt = port_msg->peer_device_type;
2423 0 : new_mcs = port_msg->mcs;
2424 0 : port->ddps = port_msg->ddps;
2425 0 : port->ldps = port_msg->legacy_device_plug_status;
2426 0 : port->dpcd_rev = port_msg->dpcd_revision;
2427 0 : port->num_sdp_streams = port_msg->num_sdp_streams;
2428 0 : port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
2429 :
2430 : /* manage mstb port lists with mgr lock - take a reference
2431 : for this list */
2432 0 : if (created) {
2433 0 : mutex_lock(&mgr->lock);
2434 0 : drm_dp_mst_topology_get_port(port);
2435 0 : list_add(&port->next, &mstb->ports);
2436 0 : mstb->num_ports++;
2437 0 : mutex_unlock(&mgr->lock);
2438 : }
2439 :
2440 : /*
2441 : * Reprobe PBN caps on both hotplug, and when re-probing the link
2442 : * for our parent mstb
2443 : */
2444 0 : if (old_ddps != port->ddps || !created) {
2445 0 : if (port->ddps && !port->input) {
2446 0 : ret = drm_dp_send_enum_path_resources(mgr, mstb,
2447 : port);
2448 0 : if (ret == 1)
2449 0 : changed = true;
2450 : } else {
2451 0 : port->full_pbn = 0;
2452 : }
2453 : }
2454 :
2455 0 : ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2456 0 : if (ret == 1) {
2457 : send_link_addr = true;
2458 0 : } else if (ret < 0) {
2459 0 : drm_err(dev, "Failed to change PDT on port %p: %d\n", port, ret);
2460 : goto fail;
2461 : }
2462 :
2463 : /*
2464 : * If this port wasn't just created, then we're reprobing because
2465 : * we're coming out of suspend. In this case, always resend the link
2466 : * address if there's an MSTB on this port
2467 : */
2468 0 : if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
2469 0 : port->mcs)
2470 0 : send_link_addr = true;
2471 :
2472 0 : if (port->connector)
2473 0 : drm_modeset_unlock(&mgr->base.lock);
2474 0 : else if (!port->input)
2475 0 : drm_dp_mst_port_add_connector(mstb, port);
2476 :
2477 0 : if (send_link_addr && port->mstb) {
2478 0 : ret = drm_dp_send_link_address(mgr, port->mstb);
2479 0 : if (ret == 1) /* MSTB below us changed */
2480 : changed = true;
2481 0 : else if (ret < 0)
2482 : goto fail_put;
2483 : }
2484 :
2485 : /* put reference to this port */
2486 0 : drm_dp_mst_topology_put_port(port);
2487 0 : return changed;
2488 :
2489 : fail:
2490 0 : drm_dp_mst_topology_unlink_port(mgr, port);
2491 0 : if (port->connector)
2492 0 : drm_modeset_unlock(&mgr->base.lock);
2493 : fail_put:
2494 0 : drm_dp_mst_topology_put_port(port);
2495 0 : return ret;
2496 : }
2497 :
2498 : static void
2499 0 : drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
2500 : struct drm_dp_connection_status_notify *conn_stat)
2501 : {
2502 0 : struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2503 : struct drm_dp_mst_port *port;
2504 : int old_ddps, ret;
2505 : u8 new_pdt;
2506 : bool new_mcs;
2507 0 : bool dowork = false, create_connector = false;
2508 :
2509 0 : port = drm_dp_get_port(mstb, conn_stat->port_number);
2510 0 : if (!port)
2511 : return;
2512 :
2513 0 : if (port->connector) {
2514 0 : if (!port->input && conn_stat->input_port) {
2515 : /*
2516 : * We can't remove a connector from an already exposed
2517 : * port, so just throw the port out and make sure we
2518 : * reprobe the link address of it's parent MSTB
2519 : */
2520 0 : drm_dp_mst_topology_unlink_port(mgr, port);
2521 0 : mstb->link_address_sent = false;
2522 0 : dowork = true;
2523 0 : goto out;
2524 : }
2525 :
2526 : /* Locking is only needed if the port's exposed to userspace */
2527 0 : drm_modeset_lock(&mgr->base.lock, NULL);
2528 0 : } else if (port->input && !conn_stat->input_port) {
2529 0 : create_connector = true;
2530 : /* Reprobe link address so we get num_sdp_streams */
2531 0 : mstb->link_address_sent = false;
2532 0 : dowork = true;
2533 : }
2534 :
2535 0 : old_ddps = port->ddps;
2536 0 : port->input = conn_stat->input_port;
2537 0 : port->ldps = conn_stat->legacy_device_plug_status;
2538 0 : port->ddps = conn_stat->displayport_device_plug_status;
2539 :
2540 0 : if (old_ddps != port->ddps) {
2541 0 : if (port->ddps && !port->input)
2542 0 : drm_dp_send_enum_path_resources(mgr, mstb, port);
2543 : else
2544 0 : port->full_pbn = 0;
2545 : }
2546 :
2547 0 : new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
2548 0 : new_mcs = conn_stat->message_capability_status;
2549 0 : ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2550 0 : if (ret == 1) {
2551 : dowork = true;
2552 0 : } else if (ret < 0) {
2553 0 : drm_err(mgr->dev, "Failed to change PDT for port %p: %d\n", port, ret);
2554 0 : dowork = false;
2555 : }
2556 :
2557 0 : if (port->connector)
2558 0 : drm_modeset_unlock(&mgr->base.lock);
2559 0 : else if (create_connector)
2560 0 : drm_dp_mst_port_add_connector(mstb, port);
2561 :
2562 : out:
2563 0 : drm_dp_mst_topology_put_port(port);
2564 0 : if (dowork)
2565 0 : queue_work(system_long_wq, &mstb->mgr->work);
2566 : }
2567 :
2568 0 : static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
2569 : u8 lct, u8 *rad)
2570 : {
2571 : struct drm_dp_mst_branch *mstb;
2572 : struct drm_dp_mst_port *port;
2573 : int i, ret;
2574 : /* find the port by iterating down */
2575 :
2576 0 : mutex_lock(&mgr->lock);
2577 0 : mstb = mgr->mst_primary;
2578 :
2579 0 : if (!mstb)
2580 : goto out;
2581 :
2582 0 : for (i = 0; i < lct - 1; i++) {
2583 0 : int shift = (i % 2) ? 0 : 4;
2584 0 : int port_num = (rad[i / 2] >> shift) & 0xf;
2585 :
2586 0 : list_for_each_entry(port, &mstb->ports, next) {
2587 0 : if (port->port_num == port_num) {
2588 0 : mstb = port->mstb;
2589 0 : if (!mstb) {
2590 0 : drm_err(mgr->dev,
2591 : "failed to lookup MSTB with lct %d, rad %02x\n",
2592 : lct, rad[0]);
2593 0 : goto out;
2594 : }
2595 :
2596 : break;
2597 : }
2598 : }
2599 : }
2600 0 : ret = drm_dp_mst_topology_try_get_mstb(mstb);
2601 0 : if (!ret)
2602 0 : mstb = NULL;
2603 : out:
2604 0 : mutex_unlock(&mgr->lock);
2605 0 : return mstb;
2606 : }
2607 :
2608 0 : static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
2609 : struct drm_dp_mst_branch *mstb,
2610 : const uint8_t *guid)
2611 : {
2612 : struct drm_dp_mst_branch *found_mstb;
2613 : struct drm_dp_mst_port *port;
2614 :
2615 0 : if (memcmp(mstb->guid, guid, 16) == 0)
2616 : return mstb;
2617 :
2618 :
2619 0 : list_for_each_entry(port, &mstb->ports, next) {
2620 0 : if (!port->mstb)
2621 0 : continue;
2622 :
2623 0 : found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
2624 :
2625 0 : if (found_mstb)
2626 : return found_mstb;
2627 : }
2628 :
2629 : return NULL;
2630 : }
2631 :
2632 : static struct drm_dp_mst_branch *
2633 0 : drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
2634 : const uint8_t *guid)
2635 : {
2636 : struct drm_dp_mst_branch *mstb;
2637 : int ret;
2638 :
2639 : /* find the port by iterating down */
2640 0 : mutex_lock(&mgr->lock);
2641 :
2642 0 : mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
2643 0 : if (mstb) {
2644 0 : ret = drm_dp_mst_topology_try_get_mstb(mstb);
2645 0 : if (!ret)
2646 0 : mstb = NULL;
2647 : }
2648 :
2649 0 : mutex_unlock(&mgr->lock);
2650 0 : return mstb;
2651 : }
2652 :
2653 0 : static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2654 : struct drm_dp_mst_branch *mstb)
2655 : {
2656 : struct drm_dp_mst_port *port;
2657 : int ret;
2658 0 : bool changed = false;
2659 :
2660 0 : if (!mstb->link_address_sent) {
2661 0 : ret = drm_dp_send_link_address(mgr, mstb);
2662 0 : if (ret == 1)
2663 : changed = true;
2664 0 : else if (ret < 0)
2665 : return ret;
2666 : }
2667 :
2668 0 : list_for_each_entry(port, &mstb->ports, next) {
2669 0 : struct drm_dp_mst_branch *mstb_child = NULL;
2670 :
2671 0 : if (port->input || !port->ddps)
2672 0 : continue;
2673 :
2674 0 : if (port->mstb)
2675 0 : mstb_child = drm_dp_mst_topology_get_mstb_validated(
2676 : mgr, port->mstb);
2677 :
2678 0 : if (mstb_child) {
2679 0 : ret = drm_dp_check_and_send_link_address(mgr,
2680 : mstb_child);
2681 0 : drm_dp_mst_topology_put_mstb(mstb_child);
2682 0 : if (ret == 1)
2683 : changed = true;
2684 0 : else if (ret < 0)
2685 : return ret;
2686 : }
2687 : }
2688 :
2689 0 : return changed;
2690 : }
2691 :
2692 0 : static void drm_dp_mst_link_probe_work(struct work_struct *work)
2693 : {
2694 0 : struct drm_dp_mst_topology_mgr *mgr =
2695 0 : container_of(work, struct drm_dp_mst_topology_mgr, work);
2696 0 : struct drm_device *dev = mgr->dev;
2697 : struct drm_dp_mst_branch *mstb;
2698 : int ret;
2699 : bool clear_payload_id_table;
2700 :
2701 0 : mutex_lock(&mgr->probe_lock);
2702 :
2703 0 : mutex_lock(&mgr->lock);
2704 0 : clear_payload_id_table = !mgr->payload_id_table_cleared;
2705 0 : mgr->payload_id_table_cleared = true;
2706 :
2707 0 : mstb = mgr->mst_primary;
2708 0 : if (mstb) {
2709 0 : ret = drm_dp_mst_topology_try_get_mstb(mstb);
2710 0 : if (!ret)
2711 0 : mstb = NULL;
2712 : }
2713 0 : mutex_unlock(&mgr->lock);
2714 0 : if (!mstb) {
2715 0 : mutex_unlock(&mgr->probe_lock);
2716 0 : return;
2717 : }
2718 :
2719 : /*
2720 : * Certain branch devices seem to incorrectly report an available_pbn
2721 : * of 0 on downstream sinks, even after clearing the
2722 : * DP_PAYLOAD_ALLOCATE_* registers in
2723 : * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
2724 : * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
2725 : * things work again.
2726 : */
2727 0 : if (clear_payload_id_table) {
2728 0 : drm_dbg_kms(dev, "Clearing payload ID table\n");
2729 0 : drm_dp_send_clear_payload_id_table(mgr, mstb);
2730 : }
2731 :
2732 0 : ret = drm_dp_check_and_send_link_address(mgr, mstb);
2733 0 : drm_dp_mst_topology_put_mstb(mstb);
2734 :
2735 0 : mutex_unlock(&mgr->probe_lock);
2736 0 : if (ret > 0)
2737 0 : drm_kms_helper_hotplug_event(dev);
2738 : }
2739 :
2740 0 : static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
2741 : u8 *guid)
2742 : {
2743 : u64 salt;
2744 :
2745 0 : if (memchr_inv(guid, 0, 16))
2746 : return true;
2747 :
2748 0 : salt = get_jiffies_64();
2749 :
2750 0 : memcpy(&guid[0], &salt, sizeof(u64));
2751 0 : memcpy(&guid[8], &salt, sizeof(u64));
2752 :
2753 : return false;
2754 : }
2755 :
2756 0 : static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg,
2757 : u8 port_num, u32 offset, u8 num_bytes)
2758 : {
2759 : struct drm_dp_sideband_msg_req_body req;
2760 :
2761 0 : req.req_type = DP_REMOTE_DPCD_READ;
2762 0 : req.u.dpcd_read.port_number = port_num;
2763 0 : req.u.dpcd_read.dpcd_address = offset;
2764 0 : req.u.dpcd_read.num_bytes = num_bytes;
2765 0 : drm_dp_encode_sideband_req(&req, msg);
2766 0 : }
2767 :
2768 0 : static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
2769 : bool up, u8 *msg, int len)
2770 : {
2771 : int ret;
2772 0 : int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
2773 : int tosend, total, offset;
2774 0 : int retries = 0;
2775 :
2776 : retry:
2777 0 : total = len;
2778 0 : offset = 0;
2779 : do {
2780 0 : tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
2781 :
2782 0 : ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
2783 0 : &msg[offset],
2784 : tosend);
2785 0 : if (ret != tosend) {
2786 0 : if (ret == -EIO && retries < 5) {
2787 0 : retries++;
2788 0 : goto retry;
2789 : }
2790 0 : drm_dbg_kms(mgr->dev, "failed to dpcd write %d %d\n", tosend, ret);
2791 :
2792 0 : return -EIO;
2793 : }
2794 0 : offset += tosend;
2795 0 : total -= tosend;
2796 0 : } while (total > 0);
2797 : return 0;
2798 : }
2799 :
2800 0 : static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
2801 : struct drm_dp_sideband_msg_tx *txmsg)
2802 : {
2803 0 : struct drm_dp_mst_branch *mstb = txmsg->dst;
2804 : u8 req_type;
2805 :
2806 0 : req_type = txmsg->msg[0] & 0x7f;
2807 0 : if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
2808 0 : req_type == DP_RESOURCE_STATUS_NOTIFY ||
2809 : req_type == DP_CLEAR_PAYLOAD_ID_TABLE)
2810 0 : hdr->broadcast = 1;
2811 : else
2812 0 : hdr->broadcast = 0;
2813 0 : hdr->path_msg = txmsg->path_msg;
2814 0 : if (hdr->broadcast) {
2815 0 : hdr->lct = 1;
2816 0 : hdr->lcr = 6;
2817 : } else {
2818 0 : hdr->lct = mstb->lct;
2819 0 : hdr->lcr = mstb->lct - 1;
2820 : }
2821 :
2822 0 : memcpy(hdr->rad, mstb->rad, hdr->lct / 2);
2823 :
2824 0 : return 0;
2825 : }
2826 : /*
2827 : * process a single block of the next message in the sideband queue
2828 : */
2829 0 : static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2830 : struct drm_dp_sideband_msg_tx *txmsg,
2831 : bool up)
2832 : {
2833 : u8 chunk[48];
2834 : struct drm_dp_sideband_msg_hdr hdr;
2835 : int len, space, idx, tosend;
2836 : int ret;
2837 :
2838 0 : if (txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
2839 : return 0;
2840 :
2841 0 : memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
2842 :
2843 0 : if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED)
2844 0 : txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
2845 :
2846 : /* make hdr from dst mst */
2847 0 : ret = set_hdr_from_dst_qlock(&hdr, txmsg);
2848 0 : if (ret < 0)
2849 : return ret;
2850 :
2851 : /* amount left to send in this message */
2852 0 : len = txmsg->cur_len - txmsg->cur_offset;
2853 :
2854 : /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
2855 0 : space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
2856 :
2857 0 : tosend = min(len, space);
2858 0 : if (len == txmsg->cur_len)
2859 0 : hdr.somt = 1;
2860 0 : if (space >= len)
2861 0 : hdr.eomt = 1;
2862 :
2863 :
2864 0 : hdr.msg_len = tosend + 1;
2865 0 : drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
2866 0 : memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
2867 : /* add crc at end */
2868 0 : drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
2869 0 : idx += tosend + 1;
2870 :
2871 0 : ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
2872 0 : if (ret) {
2873 0 : if (drm_debug_enabled(DRM_UT_DP)) {
2874 0 : struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2875 :
2876 0 : drm_printf(&p, "sideband msg failed to send\n");
2877 0 : drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2878 : }
2879 : return ret;
2880 : }
2881 :
2882 0 : txmsg->cur_offset += tosend;
2883 0 : if (txmsg->cur_offset == txmsg->cur_len) {
2884 0 : txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
2885 0 : return 1;
2886 : }
2887 : return 0;
2888 : }
2889 :
2890 0 : static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
2891 : {
2892 : struct drm_dp_sideband_msg_tx *txmsg;
2893 : int ret;
2894 :
2895 0 : WARN_ON(!mutex_is_locked(&mgr->qlock));
2896 :
2897 : /* construct a chunk from the first msg in the tx_msg queue */
2898 0 : if (list_empty(&mgr->tx_msg_downq))
2899 : return;
2900 :
2901 0 : txmsg = list_first_entry(&mgr->tx_msg_downq,
2902 : struct drm_dp_sideband_msg_tx, next);
2903 0 : ret = process_single_tx_qlock(mgr, txmsg, false);
2904 0 : if (ret < 0) {
2905 0 : drm_dbg_kms(mgr->dev, "failed to send msg in q %d\n", ret);
2906 0 : list_del(&txmsg->next);
2907 0 : txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
2908 0 : wake_up_all(&mgr->tx_waitq);
2909 : }
2910 : }
2911 :
2912 0 : static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
2913 : struct drm_dp_sideband_msg_tx *txmsg)
2914 : {
2915 0 : mutex_lock(&mgr->qlock);
2916 0 : list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
2917 :
2918 0 : if (drm_debug_enabled(DRM_UT_DP)) {
2919 0 : struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2920 :
2921 0 : drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2922 : }
2923 :
2924 0 : if (list_is_singular(&mgr->tx_msg_downq))
2925 0 : process_single_down_tx_qlock(mgr);
2926 0 : mutex_unlock(&mgr->qlock);
2927 0 : }
2928 :
2929 : static void
2930 0 : drm_dp_dump_link_address(const struct drm_dp_mst_topology_mgr *mgr,
2931 : struct drm_dp_link_address_ack_reply *reply)
2932 : {
2933 : struct drm_dp_link_addr_reply_port *port_reply;
2934 : int i;
2935 :
2936 0 : for (i = 0; i < reply->nports; i++) {
2937 0 : port_reply = &reply->ports[i];
2938 0 : drm_dbg_kms(mgr->dev,
2939 : "port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n",
2940 : i,
2941 : port_reply->input_port,
2942 : port_reply->peer_device_type,
2943 : port_reply->port_number,
2944 : port_reply->dpcd_revision,
2945 : port_reply->mcs,
2946 : port_reply->ddps,
2947 : port_reply->legacy_device_plug_status,
2948 : port_reply->num_sdp_streams,
2949 : port_reply->num_sdp_stream_sinks);
2950 : }
2951 0 : }
2952 :
2953 0 : static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2954 : struct drm_dp_mst_branch *mstb)
2955 : {
2956 : struct drm_dp_sideband_msg_tx *txmsg;
2957 : struct drm_dp_link_address_ack_reply *reply;
2958 : struct drm_dp_mst_port *port, *tmp;
2959 0 : int i, ret, port_mask = 0;
2960 0 : bool changed = false;
2961 :
2962 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2963 0 : if (!txmsg)
2964 : return -ENOMEM;
2965 :
2966 0 : txmsg->dst = mstb;
2967 0 : build_link_address(txmsg);
2968 :
2969 0 : mstb->link_address_sent = true;
2970 0 : drm_dp_queue_down_tx(mgr, txmsg);
2971 :
2972 : /* FIXME: Actually do some real error handling here */
2973 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2974 0 : if (ret <= 0) {
2975 0 : drm_err(mgr->dev, "Sending link address failed with %d\n", ret);
2976 0 : goto out;
2977 : }
2978 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2979 0 : drm_err(mgr->dev, "link address NAK received\n");
2980 0 : ret = -EIO;
2981 0 : goto out;
2982 : }
2983 :
2984 0 : reply = &txmsg->reply.u.link_addr;
2985 0 : drm_dbg_kms(mgr->dev, "link address reply: %d\n", reply->nports);
2986 0 : drm_dp_dump_link_address(mgr, reply);
2987 :
2988 0 : ret = drm_dp_check_mstb_guid(mstb, reply->guid);
2989 0 : if (ret) {
2990 : char buf[64];
2991 :
2992 0 : drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf));
2993 0 : drm_err(mgr->dev, "GUID check on %s failed: %d\n", buf, ret);
2994 : goto out;
2995 : }
2996 :
2997 0 : for (i = 0; i < reply->nports; i++) {
2998 0 : port_mask |= BIT(reply->ports[i].port_number);
2999 0 : ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev,
3000 : &reply->ports[i]);
3001 0 : if (ret == 1)
3002 : changed = true;
3003 0 : else if (ret < 0)
3004 : goto out;
3005 : }
3006 :
3007 : /* Prune any ports that are currently a part of mstb in our in-memory
3008 : * topology, but were not seen in this link address. Usually this
3009 : * means that they were removed while the topology was out of sync,
3010 : * e.g. during suspend/resume
3011 : */
3012 0 : mutex_lock(&mgr->lock);
3013 0 : list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
3014 0 : if (port_mask & BIT(port->port_num))
3015 0 : continue;
3016 :
3017 0 : drm_dbg_kms(mgr->dev, "port %d was not in link address, removing\n",
3018 : port->port_num);
3019 0 : list_del(&port->next);
3020 0 : drm_dp_mst_topology_put_port(port);
3021 0 : changed = true;
3022 : }
3023 0 : mutex_unlock(&mgr->lock);
3024 :
3025 : out:
3026 0 : if (ret <= 0)
3027 0 : mstb->link_address_sent = false;
3028 0 : kfree(txmsg);
3029 0 : return ret < 0 ? ret : changed;
3030 : }
3031 :
3032 : static void
3033 0 : drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
3034 : struct drm_dp_mst_branch *mstb)
3035 : {
3036 : struct drm_dp_sideband_msg_tx *txmsg;
3037 : int ret;
3038 :
3039 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3040 0 : if (!txmsg)
3041 : return;
3042 :
3043 0 : txmsg->dst = mstb;
3044 0 : build_clear_payload_id_table(txmsg);
3045 :
3046 0 : drm_dp_queue_down_tx(mgr, txmsg);
3047 :
3048 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3049 0 : if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3050 0 : drm_dbg_kms(mgr->dev, "clear payload table id nak received\n");
3051 :
3052 0 : kfree(txmsg);
3053 : }
3054 :
3055 : static int
3056 0 : drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
3057 : struct drm_dp_mst_branch *mstb,
3058 : struct drm_dp_mst_port *port)
3059 : {
3060 : struct drm_dp_enum_path_resources_ack_reply *path_res;
3061 : struct drm_dp_sideband_msg_tx *txmsg;
3062 : int ret;
3063 :
3064 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3065 0 : if (!txmsg)
3066 : return -ENOMEM;
3067 :
3068 0 : txmsg->dst = mstb;
3069 0 : build_enum_path_resources(txmsg, port->port_num);
3070 :
3071 0 : drm_dp_queue_down_tx(mgr, txmsg);
3072 :
3073 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3074 0 : if (ret > 0) {
3075 0 : ret = 0;
3076 0 : path_res = &txmsg->reply.u.path_resources;
3077 :
3078 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3079 0 : drm_dbg_kms(mgr->dev, "enum path resources nak received\n");
3080 : } else {
3081 0 : if (port->port_num != path_res->port_number)
3082 0 : DRM_ERROR("got incorrect port in response\n");
3083 :
3084 0 : drm_dbg_kms(mgr->dev, "enum path resources %d: %d %d\n",
3085 : path_res->port_number,
3086 : path_res->full_payload_bw_number,
3087 : path_res->avail_payload_bw_number);
3088 :
3089 : /*
3090 : * If something changed, make sure we send a
3091 : * hotplug
3092 : */
3093 0 : if (port->full_pbn != path_res->full_payload_bw_number ||
3094 0 : port->fec_capable != path_res->fec_capable)
3095 0 : ret = 1;
3096 :
3097 0 : port->full_pbn = path_res->full_payload_bw_number;
3098 0 : port->fec_capable = path_res->fec_capable;
3099 : }
3100 : }
3101 :
3102 0 : kfree(txmsg);
3103 0 : return ret;
3104 : }
3105 :
3106 0 : static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
3107 : {
3108 0 : if (!mstb->port_parent)
3109 : return NULL;
3110 :
3111 0 : if (mstb->port_parent->mstb != mstb)
3112 : return mstb->port_parent;
3113 :
3114 0 : return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
3115 : }
3116 :
3117 : /*
3118 : * Searches upwards in the topology starting from mstb to try to find the
3119 : * closest available parent of mstb that's still connected to the rest of the
3120 : * topology. This can be used in order to perform operations like releasing
3121 : * payloads, where the branch device which owned the payload may no longer be
3122 : * around and thus would require that the payload on the last living relative
3123 : * be freed instead.
3124 : */
3125 : static struct drm_dp_mst_branch *
3126 0 : drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
3127 : struct drm_dp_mst_branch *mstb,
3128 : int *port_num)
3129 : {
3130 0 : struct drm_dp_mst_branch *rmstb = NULL;
3131 : struct drm_dp_mst_port *found_port;
3132 :
3133 0 : mutex_lock(&mgr->lock);
3134 0 : if (!mgr->mst_primary)
3135 : goto out;
3136 :
3137 : do {
3138 0 : found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
3139 0 : if (!found_port)
3140 : break;
3141 :
3142 0 : if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
3143 0 : rmstb = found_port->parent;
3144 0 : *port_num = found_port->port_num;
3145 : } else {
3146 : /* Search again, starting from this parent */
3147 0 : mstb = found_port->parent;
3148 : }
3149 0 : } while (!rmstb);
3150 : out:
3151 0 : mutex_unlock(&mgr->lock);
3152 0 : return rmstb;
3153 : }
3154 :
3155 0 : static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
3156 : struct drm_dp_mst_port *port,
3157 : int id,
3158 : int pbn)
3159 : {
3160 : struct drm_dp_sideband_msg_tx *txmsg;
3161 : struct drm_dp_mst_branch *mstb;
3162 : int ret, port_num;
3163 : u8 sinks[DRM_DP_MAX_SDP_STREAMS];
3164 : int i;
3165 :
3166 0 : port_num = port->port_num;
3167 0 : mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3168 0 : if (!mstb) {
3169 0 : mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
3170 : port->parent,
3171 : &port_num);
3172 :
3173 0 : if (!mstb)
3174 : return -EINVAL;
3175 : }
3176 :
3177 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3178 0 : if (!txmsg) {
3179 : ret = -ENOMEM;
3180 : goto fail_put;
3181 : }
3182 :
3183 0 : for (i = 0; i < port->num_sdp_streams; i++)
3184 0 : sinks[i] = i;
3185 :
3186 0 : txmsg->dst = mstb;
3187 0 : build_allocate_payload(txmsg, port_num,
3188 : id,
3189 : pbn, port->num_sdp_streams, sinks);
3190 :
3191 0 : drm_dp_queue_down_tx(mgr, txmsg);
3192 :
3193 : /*
3194 : * FIXME: there is a small chance that between getting the last
3195 : * connected mstb and sending the payload message, the last connected
3196 : * mstb could also be removed from the topology. In the future, this
3197 : * needs to be fixed by restarting the
3198 : * drm_dp_get_last_connected_port_and_mstb() search in the event of a
3199 : * timeout if the topology is still connected to the system.
3200 : */
3201 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3202 0 : if (ret > 0) {
3203 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3204 : ret = -EINVAL;
3205 : else
3206 0 : ret = 0;
3207 : }
3208 0 : kfree(txmsg);
3209 : fail_put:
3210 0 : drm_dp_mst_topology_put_mstb(mstb);
3211 0 : return ret;
3212 : }
3213 :
3214 0 : int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
3215 : struct drm_dp_mst_port *port, bool power_up)
3216 : {
3217 : struct drm_dp_sideband_msg_tx *txmsg;
3218 : int ret;
3219 :
3220 0 : port = drm_dp_mst_topology_get_port_validated(mgr, port);
3221 0 : if (!port)
3222 : return -EINVAL;
3223 :
3224 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3225 0 : if (!txmsg) {
3226 0 : drm_dp_mst_topology_put_port(port);
3227 0 : return -ENOMEM;
3228 : }
3229 :
3230 0 : txmsg->dst = port->parent;
3231 0 : build_power_updown_phy(txmsg, port->port_num, power_up);
3232 0 : drm_dp_queue_down_tx(mgr, txmsg);
3233 :
3234 0 : ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
3235 0 : if (ret > 0) {
3236 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3237 : ret = -EINVAL;
3238 : else
3239 0 : ret = 0;
3240 : }
3241 0 : kfree(txmsg);
3242 0 : drm_dp_mst_topology_put_port(port);
3243 :
3244 0 : return ret;
3245 : }
3246 : EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
3247 :
3248 0 : int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr,
3249 : struct drm_dp_mst_port *port,
3250 : struct drm_dp_query_stream_enc_status_ack_reply *status)
3251 : {
3252 : struct drm_dp_sideband_msg_tx *txmsg;
3253 : u8 nonce[7];
3254 : int ret;
3255 :
3256 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3257 0 : if (!txmsg)
3258 : return -ENOMEM;
3259 :
3260 0 : port = drm_dp_mst_topology_get_port_validated(mgr, port);
3261 0 : if (!port) {
3262 : ret = -EINVAL;
3263 : goto out_get_port;
3264 : }
3265 :
3266 0 : get_random_bytes(nonce, sizeof(nonce));
3267 :
3268 : /*
3269 : * "Source device targets the QUERY_STREAM_ENCRYPTION_STATUS message
3270 : * transaction at the MST Branch device directly connected to the
3271 : * Source"
3272 : */
3273 0 : txmsg->dst = mgr->mst_primary;
3274 :
3275 0 : build_query_stream_enc_status(txmsg, port->vcpi.vcpi, nonce);
3276 :
3277 0 : drm_dp_queue_down_tx(mgr, txmsg);
3278 :
3279 0 : ret = drm_dp_mst_wait_tx_reply(mgr->mst_primary, txmsg);
3280 0 : if (ret < 0) {
3281 : goto out;
3282 0 : } else if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3283 0 : drm_dbg_kms(mgr->dev, "query encryption status nak received\n");
3284 0 : ret = -ENXIO;
3285 0 : goto out;
3286 : }
3287 :
3288 0 : ret = 0;
3289 0 : memcpy(status, &txmsg->reply.u.enc_status, sizeof(*status));
3290 :
3291 : out:
3292 0 : drm_dp_mst_topology_put_port(port);
3293 : out_get_port:
3294 0 : kfree(txmsg);
3295 0 : return ret;
3296 : }
3297 : EXPORT_SYMBOL(drm_dp_send_query_stream_enc_status);
3298 :
3299 : static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3300 : int id,
3301 : struct drm_dp_payload *payload)
3302 : {
3303 : int ret;
3304 :
3305 0 : ret = drm_dp_dpcd_write_payload(mgr, id, payload);
3306 0 : if (ret < 0) {
3307 0 : payload->payload_state = 0;
3308 : return ret;
3309 : }
3310 0 : payload->payload_state = DP_PAYLOAD_LOCAL;
3311 : return 0;
3312 : }
3313 :
3314 : static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3315 : struct drm_dp_mst_port *port,
3316 : int id,
3317 : struct drm_dp_payload *payload)
3318 : {
3319 : int ret;
3320 :
3321 0 : ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
3322 0 : if (ret < 0)
3323 : return ret;
3324 0 : payload->payload_state = DP_PAYLOAD_REMOTE;
3325 : return ret;
3326 : }
3327 :
3328 0 : static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3329 : struct drm_dp_mst_port *port,
3330 : int id,
3331 : struct drm_dp_payload *payload)
3332 : {
3333 0 : drm_dbg_kms(mgr->dev, "\n");
3334 : /* it's okay for these to fail */
3335 0 : if (port) {
3336 0 : drm_dp_payload_send_msg(mgr, port, id, 0);
3337 : }
3338 :
3339 0 : drm_dp_dpcd_write_payload(mgr, id, payload);
3340 0 : payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
3341 0 : return 0;
3342 : }
3343 :
3344 : static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3345 : int id,
3346 : struct drm_dp_payload *payload)
3347 : {
3348 0 : payload->payload_state = 0;
3349 : return 0;
3350 : }
3351 :
3352 : /**
3353 : * drm_dp_update_payload_part1() - Execute payload update part 1
3354 : * @mgr: manager to use.
3355 : * @start_slot: this is the cur slot
3356 : *
3357 : * NOTE: start_slot is a temporary workaround for non-atomic drivers,
3358 : * this will be removed when non-atomic mst helpers are moved out of the helper
3359 : *
3360 : * This iterates over all proposed virtual channels, and tries to
3361 : * allocate space in the link for them. For 0->slots transitions,
3362 : * this step just writes the VCPI to the MST device. For slots->0
3363 : * transitions, this writes the updated VCPIs and removes the
3364 : * remote VC payloads.
3365 : *
3366 : * after calling this the driver should generate ACT and payload
3367 : * packets.
3368 : */
3369 0 : int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr, int start_slot)
3370 : {
3371 : struct drm_dp_payload req_payload;
3372 : struct drm_dp_mst_port *port;
3373 : int i, j;
3374 0 : int cur_slots = start_slot;
3375 : bool skip;
3376 :
3377 0 : mutex_lock(&mgr->payload_lock);
3378 0 : for (i = 0; i < mgr->max_payloads; i++) {
3379 0 : struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
3380 0 : struct drm_dp_payload *payload = &mgr->payloads[i];
3381 0 : bool put_port = false;
3382 :
3383 : /* solve the current payloads - compare to the hw ones
3384 : - update the hw view */
3385 0 : req_payload.start_slot = cur_slots;
3386 0 : if (vcpi) {
3387 0 : port = container_of(vcpi, struct drm_dp_mst_port,
3388 : vcpi);
3389 :
3390 0 : mutex_lock(&mgr->lock);
3391 0 : skip = !drm_dp_mst_port_downstream_of_branch(port, mgr->mst_primary);
3392 0 : mutex_unlock(&mgr->lock);
3393 :
3394 0 : if (skip) {
3395 0 : drm_dbg_kms(mgr->dev,
3396 : "Virtual channel %d is not in current topology\n",
3397 : i);
3398 0 : continue;
3399 : }
3400 : /* Validated ports don't matter if we're releasing
3401 : * VCPI
3402 : */
3403 0 : if (vcpi->num_slots) {
3404 0 : port = drm_dp_mst_topology_get_port_validated(
3405 : mgr, port);
3406 0 : if (!port) {
3407 0 : if (vcpi->num_slots == payload->num_slots) {
3408 0 : cur_slots += vcpi->num_slots;
3409 0 : payload->start_slot = req_payload.start_slot;
3410 0 : continue;
3411 : } else {
3412 0 : drm_dbg_kms(mgr->dev,
3413 : "Fail:set payload to invalid sink");
3414 0 : mutex_unlock(&mgr->payload_lock);
3415 0 : return -EINVAL;
3416 : }
3417 : }
3418 : put_port = true;
3419 : }
3420 :
3421 0 : req_payload.num_slots = vcpi->num_slots;
3422 0 : req_payload.vcpi = vcpi->vcpi;
3423 : } else {
3424 0 : port = NULL;
3425 0 : req_payload.num_slots = 0;
3426 : }
3427 :
3428 0 : payload->start_slot = req_payload.start_slot;
3429 : /* work out what is required to happen with this payload */
3430 0 : if (payload->num_slots != req_payload.num_slots) {
3431 :
3432 : /* need to push an update for this payload */
3433 0 : if (req_payload.num_slots) {
3434 0 : drm_dp_create_payload_step1(mgr, vcpi->vcpi,
3435 : &req_payload);
3436 0 : payload->num_slots = req_payload.num_slots;
3437 0 : payload->vcpi = req_payload.vcpi;
3438 :
3439 0 : } else if (payload->num_slots) {
3440 0 : payload->num_slots = 0;
3441 0 : drm_dp_destroy_payload_step1(mgr, port,
3442 : payload->vcpi,
3443 : payload);
3444 0 : req_payload.payload_state =
3445 0 : payload->payload_state;
3446 0 : payload->start_slot = 0;
3447 : }
3448 0 : payload->payload_state = req_payload.payload_state;
3449 : }
3450 0 : cur_slots += req_payload.num_slots;
3451 :
3452 0 : if (put_port)
3453 0 : drm_dp_mst_topology_put_port(port);
3454 : }
3455 :
3456 0 : for (i = 0; i < mgr->max_payloads; /* do nothing */) {
3457 0 : if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL) {
3458 0 : i++;
3459 0 : continue;
3460 : }
3461 :
3462 0 : drm_dbg_kms(mgr->dev, "removing payload %d\n", i);
3463 0 : for (j = i; j < mgr->max_payloads - 1; j++) {
3464 0 : mgr->payloads[j] = mgr->payloads[j + 1];
3465 0 : mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
3466 :
3467 0 : if (mgr->proposed_vcpis[j] &&
3468 0 : mgr->proposed_vcpis[j]->num_slots) {
3469 0 : set_bit(j + 1, &mgr->payload_mask);
3470 : } else {
3471 0 : clear_bit(j + 1, &mgr->payload_mask);
3472 : }
3473 : }
3474 :
3475 0 : memset(&mgr->payloads[mgr->max_payloads - 1], 0,
3476 : sizeof(struct drm_dp_payload));
3477 0 : mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
3478 0 : clear_bit(mgr->max_payloads, &mgr->payload_mask);
3479 : }
3480 0 : mutex_unlock(&mgr->payload_lock);
3481 :
3482 0 : return 0;
3483 : }
3484 : EXPORT_SYMBOL(drm_dp_update_payload_part1);
3485 :
3486 : /**
3487 : * drm_dp_update_payload_part2() - Execute payload update part 2
3488 : * @mgr: manager to use.
3489 : *
3490 : * This iterates over all proposed virtual channels, and tries to
3491 : * allocate space in the link for them. For 0->slots transitions,
3492 : * this step writes the remote VC payload commands. For slots->0
3493 : * this just resets some internal state.
3494 : */
3495 0 : int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
3496 : {
3497 : struct drm_dp_mst_port *port;
3498 : int i;
3499 0 : int ret = 0;
3500 : bool skip;
3501 :
3502 0 : mutex_lock(&mgr->payload_lock);
3503 0 : for (i = 0; i < mgr->max_payloads; i++) {
3504 :
3505 0 : if (!mgr->proposed_vcpis[i])
3506 0 : continue;
3507 :
3508 0 : port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
3509 :
3510 0 : mutex_lock(&mgr->lock);
3511 0 : skip = !drm_dp_mst_port_downstream_of_branch(port, mgr->mst_primary);
3512 0 : mutex_unlock(&mgr->lock);
3513 :
3514 0 : if (skip)
3515 0 : continue;
3516 :
3517 0 : drm_dbg_kms(mgr->dev, "payload %d %d\n", i, mgr->payloads[i].payload_state);
3518 0 : if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
3519 0 : ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3520 0 : } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
3521 0 : ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3522 : }
3523 0 : if (ret) {
3524 0 : mutex_unlock(&mgr->payload_lock);
3525 0 : return ret;
3526 : }
3527 : }
3528 0 : mutex_unlock(&mgr->payload_lock);
3529 0 : return 0;
3530 : }
3531 : EXPORT_SYMBOL(drm_dp_update_payload_part2);
3532 :
3533 0 : static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
3534 : struct drm_dp_mst_port *port,
3535 : int offset, int size, u8 *bytes)
3536 : {
3537 0 : int ret = 0;
3538 : struct drm_dp_sideband_msg_tx *txmsg;
3539 : struct drm_dp_mst_branch *mstb;
3540 :
3541 0 : mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3542 0 : if (!mstb)
3543 : return -EINVAL;
3544 :
3545 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3546 0 : if (!txmsg) {
3547 : ret = -ENOMEM;
3548 : goto fail_put;
3549 : }
3550 :
3551 0 : build_dpcd_read(txmsg, port->port_num, offset, size);
3552 0 : txmsg->dst = port->parent;
3553 :
3554 0 : drm_dp_queue_down_tx(mgr, txmsg);
3555 :
3556 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3557 0 : if (ret < 0)
3558 : goto fail_free;
3559 :
3560 0 : if (txmsg->reply.reply_type == 1) {
3561 0 : drm_dbg_kms(mgr->dev, "mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n",
3562 : mstb, port->port_num, offset, size);
3563 0 : ret = -EIO;
3564 : goto fail_free;
3565 : }
3566 :
3567 0 : if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) {
3568 : ret = -EPROTO;
3569 : goto fail_free;
3570 : }
3571 :
3572 0 : ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes,
3573 : size);
3574 0 : memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret);
3575 :
3576 : fail_free:
3577 0 : kfree(txmsg);
3578 : fail_put:
3579 0 : drm_dp_mst_topology_put_mstb(mstb);
3580 :
3581 : return ret;
3582 : }
3583 :
3584 0 : static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
3585 : struct drm_dp_mst_port *port,
3586 : int offset, int size, u8 *bytes)
3587 : {
3588 : int ret;
3589 : struct drm_dp_sideband_msg_tx *txmsg;
3590 : struct drm_dp_mst_branch *mstb;
3591 :
3592 0 : mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3593 0 : if (!mstb)
3594 : return -EINVAL;
3595 :
3596 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3597 0 : if (!txmsg) {
3598 : ret = -ENOMEM;
3599 : goto fail_put;
3600 : }
3601 :
3602 0 : build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
3603 0 : txmsg->dst = mstb;
3604 :
3605 0 : drm_dp_queue_down_tx(mgr, txmsg);
3606 :
3607 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3608 0 : if (ret > 0) {
3609 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3610 : ret = -EIO;
3611 : else
3612 0 : ret = size;
3613 : }
3614 :
3615 0 : kfree(txmsg);
3616 : fail_put:
3617 0 : drm_dp_mst_topology_put_mstb(mstb);
3618 : return ret;
3619 : }
3620 :
3621 : static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
3622 : {
3623 : struct drm_dp_sideband_msg_reply_body reply;
3624 :
3625 0 : reply.reply_type = DP_SIDEBAND_REPLY_ACK;
3626 0 : reply.req_type = req_type;
3627 0 : drm_dp_encode_sideband_reply(&reply, msg);
3628 : return 0;
3629 : }
3630 :
3631 0 : static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
3632 : struct drm_dp_mst_branch *mstb,
3633 : int req_type, bool broadcast)
3634 : {
3635 : struct drm_dp_sideband_msg_tx *txmsg;
3636 :
3637 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3638 0 : if (!txmsg)
3639 : return -ENOMEM;
3640 :
3641 0 : txmsg->dst = mstb;
3642 0 : drm_dp_encode_up_ack_reply(txmsg, req_type);
3643 :
3644 0 : mutex_lock(&mgr->qlock);
3645 : /* construct a chunk from the first msg in the tx_msg queue */
3646 0 : process_single_tx_qlock(mgr, txmsg, true);
3647 0 : mutex_unlock(&mgr->qlock);
3648 :
3649 0 : kfree(txmsg);
3650 0 : return 0;
3651 : }
3652 :
3653 : /**
3654 : * drm_dp_get_vc_payload_bw - get the VC payload BW for an MST link
3655 : * @mgr: The &drm_dp_mst_topology_mgr to use
3656 : * @link_rate: link rate in 10kbits/s units
3657 : * @link_lane_count: lane count
3658 : *
3659 : * Calculate the total bandwidth of a MultiStream Transport link. The returned
3660 : * value is in units of PBNs/(timeslots/1 MTP). This value can be used to
3661 : * convert the number of PBNs required for a given stream to the number of
3662 : * timeslots this stream requires in each MTP.
3663 : */
3664 0 : int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr,
3665 : int link_rate, int link_lane_count)
3666 : {
3667 0 : if (link_rate == 0 || link_lane_count == 0)
3668 0 : drm_dbg_kms(mgr->dev, "invalid link rate/lane count: (%d / %d)\n",
3669 : link_rate, link_lane_count);
3670 :
3671 : /* See DP v2.0 2.6.4.2, VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */
3672 0 : return link_rate * link_lane_count / 54000;
3673 : }
3674 : EXPORT_SYMBOL(drm_dp_get_vc_payload_bw);
3675 :
3676 : /**
3677 : * drm_dp_read_mst_cap() - check whether or not a sink supports MST
3678 : * @aux: The DP AUX channel to use
3679 : * @dpcd: A cached copy of the DPCD capabilities for this sink
3680 : *
3681 : * Returns: %True if the sink supports MST, %false otherwise
3682 : */
3683 0 : bool drm_dp_read_mst_cap(struct drm_dp_aux *aux,
3684 : const u8 dpcd[DP_RECEIVER_CAP_SIZE])
3685 : {
3686 : u8 mstm_cap;
3687 :
3688 0 : if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_12)
3689 : return false;
3690 :
3691 0 : if (drm_dp_dpcd_readb(aux, DP_MSTM_CAP, &mstm_cap) != 1)
3692 : return false;
3693 :
3694 0 : return mstm_cap & DP_MST_CAP;
3695 : }
3696 : EXPORT_SYMBOL(drm_dp_read_mst_cap);
3697 :
3698 : /**
3699 : * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
3700 : * @mgr: manager to set state for
3701 : * @mst_state: true to enable MST on this connector - false to disable.
3702 : *
3703 : * This is called by the driver when it detects an MST capable device plugged
3704 : * into a DP MST capable port, or when a DP MST capable device is unplugged.
3705 : */
3706 0 : int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
3707 : {
3708 0 : int ret = 0;
3709 0 : struct drm_dp_mst_branch *mstb = NULL;
3710 :
3711 0 : mutex_lock(&mgr->payload_lock);
3712 0 : mutex_lock(&mgr->lock);
3713 0 : if (mst_state == mgr->mst_state)
3714 : goto out_unlock;
3715 :
3716 0 : mgr->mst_state = mst_state;
3717 : /* set the device into MST mode */
3718 0 : if (mst_state) {
3719 : struct drm_dp_payload reset_pay;
3720 : int lane_count;
3721 : int link_rate;
3722 :
3723 0 : WARN_ON(mgr->mst_primary);
3724 :
3725 : /* get dpcd info */
3726 0 : ret = drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd);
3727 0 : if (ret < 0) {
3728 0 : drm_dbg_kms(mgr->dev, "%s: failed to read DPCD, ret %d\n",
3729 : mgr->aux->name, ret);
3730 0 : goto out_unlock;
3731 : }
3732 :
3733 0 : lane_count = min_t(int, mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK, mgr->max_lane_count);
3734 0 : link_rate = min_t(int, drm_dp_bw_code_to_link_rate(mgr->dpcd[1]), mgr->max_link_rate);
3735 0 : mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr,
3736 : link_rate,
3737 : lane_count);
3738 0 : if (mgr->pbn_div == 0) {
3739 : ret = -EINVAL;
3740 : goto out_unlock;
3741 : }
3742 :
3743 : /* add initial branch device at LCT 1 */
3744 0 : mstb = drm_dp_add_mst_branch_device(1, NULL);
3745 0 : if (mstb == NULL) {
3746 : ret = -ENOMEM;
3747 : goto out_unlock;
3748 : }
3749 0 : mstb->mgr = mgr;
3750 :
3751 : /* give this the main reference */
3752 0 : mgr->mst_primary = mstb;
3753 0 : drm_dp_mst_topology_get_mstb(mgr->mst_primary);
3754 :
3755 0 : ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3756 : DP_MST_EN |
3757 : DP_UP_REQ_EN |
3758 : DP_UPSTREAM_IS_SRC);
3759 0 : if (ret < 0)
3760 : goto out_unlock;
3761 :
3762 0 : reset_pay.start_slot = 0;
3763 0 : reset_pay.num_slots = 0x3f;
3764 0 : drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
3765 :
3766 0 : queue_work(system_long_wq, &mgr->work);
3767 :
3768 0 : ret = 0;
3769 : } else {
3770 : /* disable MST on the device */
3771 0 : mstb = mgr->mst_primary;
3772 0 : mgr->mst_primary = NULL;
3773 : /* this can fail if the device is gone */
3774 0 : drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
3775 0 : ret = 0;
3776 0 : memset(mgr->payloads, 0,
3777 0 : mgr->max_payloads * sizeof(mgr->payloads[0]));
3778 0 : memset(mgr->proposed_vcpis, 0,
3779 0 : mgr->max_payloads * sizeof(mgr->proposed_vcpis[0]));
3780 0 : mgr->payload_mask = 0;
3781 0 : set_bit(0, &mgr->payload_mask);
3782 0 : mgr->vcpi_mask = 0;
3783 0 : mgr->payload_id_table_cleared = false;
3784 : }
3785 :
3786 : out_unlock:
3787 0 : mutex_unlock(&mgr->lock);
3788 0 : mutex_unlock(&mgr->payload_lock);
3789 0 : if (mstb)
3790 0 : drm_dp_mst_topology_put_mstb(mstb);
3791 0 : return ret;
3792 :
3793 : }
3794 : EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
3795 :
3796 : static void
3797 0 : drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
3798 : {
3799 : struct drm_dp_mst_port *port;
3800 :
3801 : /* The link address will need to be re-sent on resume */
3802 0 : mstb->link_address_sent = false;
3803 :
3804 0 : list_for_each_entry(port, &mstb->ports, next)
3805 0 : if (port->mstb)
3806 0 : drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb);
3807 0 : }
3808 :
3809 : /**
3810 : * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
3811 : * @mgr: manager to suspend
3812 : *
3813 : * This function tells the MST device that we can't handle UP messages
3814 : * anymore. This should stop it from sending any since we are suspended.
3815 : */
3816 0 : void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
3817 : {
3818 0 : mutex_lock(&mgr->lock);
3819 0 : drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3820 : DP_MST_EN | DP_UPSTREAM_IS_SRC);
3821 0 : mutex_unlock(&mgr->lock);
3822 0 : flush_work(&mgr->up_req_work);
3823 0 : flush_work(&mgr->work);
3824 0 : flush_work(&mgr->delayed_destroy_work);
3825 :
3826 0 : mutex_lock(&mgr->lock);
3827 0 : if (mgr->mst_state && mgr->mst_primary)
3828 0 : drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary);
3829 0 : mutex_unlock(&mgr->lock);
3830 0 : }
3831 : EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
3832 :
3833 : /**
3834 : * drm_dp_mst_topology_mgr_resume() - resume the MST manager
3835 : * @mgr: manager to resume
3836 : * @sync: whether or not to perform topology reprobing synchronously
3837 : *
3838 : * This will fetch DPCD and see if the device is still there,
3839 : * if it is, it will rewrite the MSTM control bits, and return.
3840 : *
3841 : * If the device fails this returns -1, and the driver should do
3842 : * a full MST reprobe, in case we were undocked.
3843 : *
3844 : * During system resume (where it is assumed that the driver will be calling
3845 : * drm_atomic_helper_resume()) this function should be called beforehand with
3846 : * @sync set to true. In contexts like runtime resume where the driver is not
3847 : * expected to be calling drm_atomic_helper_resume(), this function should be
3848 : * called with @sync set to false in order to avoid deadlocking.
3849 : *
3850 : * Returns: -1 if the MST topology was removed while we were suspended, 0
3851 : * otherwise.
3852 : */
3853 0 : int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
3854 : bool sync)
3855 : {
3856 : int ret;
3857 : u8 guid[16];
3858 :
3859 0 : mutex_lock(&mgr->lock);
3860 0 : if (!mgr->mst_primary)
3861 : goto out_fail;
3862 :
3863 0 : ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd,
3864 : DP_RECEIVER_CAP_SIZE);
3865 0 : if (ret != DP_RECEIVER_CAP_SIZE) {
3866 0 : drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n");
3867 0 : goto out_fail;
3868 : }
3869 :
3870 0 : ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3871 : DP_MST_EN |
3872 : DP_UP_REQ_EN |
3873 : DP_UPSTREAM_IS_SRC);
3874 0 : if (ret < 0) {
3875 0 : drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n");
3876 0 : goto out_fail;
3877 : }
3878 :
3879 : /* Some hubs forget their guids after they resume */
3880 0 : ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
3881 0 : if (ret != 16) {
3882 0 : drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n");
3883 0 : goto out_fail;
3884 : }
3885 :
3886 0 : ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid);
3887 0 : if (ret) {
3888 0 : drm_dbg_kms(mgr->dev, "check mstb failed - undocked during suspend?\n");
3889 0 : goto out_fail;
3890 : }
3891 :
3892 : /*
3893 : * For the final step of resuming the topology, we need to bring the
3894 : * state of our in-memory topology back into sync with reality. So,
3895 : * restart the probing process as if we're probing a new hub
3896 : */
3897 0 : queue_work(system_long_wq, &mgr->work);
3898 0 : mutex_unlock(&mgr->lock);
3899 :
3900 0 : if (sync) {
3901 0 : drm_dbg_kms(mgr->dev,
3902 : "Waiting for link probe work to finish re-syncing topology...\n");
3903 0 : flush_work(&mgr->work);
3904 : }
3905 :
3906 : return 0;
3907 :
3908 : out_fail:
3909 0 : mutex_unlock(&mgr->lock);
3910 0 : return -1;
3911 : }
3912 : EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
3913 :
3914 : static bool
3915 0 : drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up,
3916 : struct drm_dp_mst_branch **mstb)
3917 : {
3918 : int len;
3919 : u8 replyblock[32];
3920 : int replylen, curreply;
3921 : int ret;
3922 : u8 hdrlen;
3923 : struct drm_dp_sideband_msg_hdr hdr;
3924 0 : struct drm_dp_sideband_msg_rx *msg =
3925 0 : up ? &mgr->up_req_recv : &mgr->down_rep_recv;
3926 0 : int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE :
3927 : DP_SIDEBAND_MSG_DOWN_REP_BASE;
3928 :
3929 0 : if (!up)
3930 0 : *mstb = NULL;
3931 :
3932 0 : len = min(mgr->max_dpcd_transaction_bytes, 16);
3933 0 : ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len);
3934 0 : if (ret != len) {
3935 0 : drm_dbg_kms(mgr->dev, "failed to read DPCD down rep %d %d\n", len, ret);
3936 0 : return false;
3937 : }
3938 :
3939 0 : ret = drm_dp_decode_sideband_msg_hdr(mgr, &hdr, replyblock, len, &hdrlen);
3940 0 : if (ret == false) {
3941 0 : print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16,
3942 : 1, replyblock, len, false);
3943 0 : drm_dbg_kms(mgr->dev, "ERROR: failed header\n");
3944 0 : return false;
3945 : }
3946 :
3947 0 : if (!up) {
3948 : /* Caller is responsible for giving back this reference */
3949 0 : *mstb = drm_dp_get_mst_branch_device(mgr, hdr.lct, hdr.rad);
3950 0 : if (!*mstb) {
3951 0 : drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr.lct);
3952 0 : return false;
3953 : }
3954 : }
3955 :
3956 0 : if (!drm_dp_sideband_msg_set_header(msg, &hdr, hdrlen)) {
3957 0 : drm_dbg_kms(mgr->dev, "sideband msg set header failed %d\n", replyblock[0]);
3958 0 : return false;
3959 : }
3960 :
3961 0 : replylen = min(msg->curchunk_len, (u8)(len - hdrlen));
3962 0 : ret = drm_dp_sideband_append_payload(msg, replyblock + hdrlen, replylen);
3963 0 : if (!ret) {
3964 0 : drm_dbg_kms(mgr->dev, "sideband msg build failed %d\n", replyblock[0]);
3965 0 : return false;
3966 : }
3967 :
3968 0 : replylen = msg->curchunk_len + msg->curchunk_hdrlen - len;
3969 0 : curreply = len;
3970 0 : while (replylen > 0) {
3971 0 : len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
3972 0 : ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
3973 : replyblock, len);
3974 0 : if (ret != len) {
3975 0 : drm_dbg_kms(mgr->dev, "failed to read a chunk (len %d, ret %d)\n",
3976 : len, ret);
3977 0 : return false;
3978 : }
3979 :
3980 0 : ret = drm_dp_sideband_append_payload(msg, replyblock, len);
3981 0 : if (!ret) {
3982 0 : drm_dbg_kms(mgr->dev, "failed to build sideband msg\n");
3983 0 : return false;
3984 : }
3985 :
3986 0 : curreply += len;
3987 0 : replylen -= len;
3988 : }
3989 : return true;
3990 : }
3991 :
3992 0 : static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
3993 : {
3994 : struct drm_dp_sideband_msg_tx *txmsg;
3995 0 : struct drm_dp_mst_branch *mstb = NULL;
3996 0 : struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv;
3997 :
3998 0 : if (!drm_dp_get_one_sb_msg(mgr, false, &mstb))
3999 : goto out;
4000 :
4001 : /* Multi-packet message transmission, don't clear the reply */
4002 0 : if (!msg->have_eomt)
4003 : goto out;
4004 :
4005 : /* find the message */
4006 0 : mutex_lock(&mgr->qlock);
4007 0 : txmsg = list_first_entry_or_null(&mgr->tx_msg_downq,
4008 : struct drm_dp_sideband_msg_tx, next);
4009 0 : mutex_unlock(&mgr->qlock);
4010 :
4011 : /* Were we actually expecting a response, and from this mstb? */
4012 0 : if (!txmsg || txmsg->dst != mstb) {
4013 : struct drm_dp_sideband_msg_hdr *hdr;
4014 :
4015 0 : hdr = &msg->initial_hdr;
4016 0 : drm_dbg_kms(mgr->dev, "Got MST reply with no msg %p %d %d %02x %02x\n",
4017 : mstb, hdr->seqno, hdr->lct, hdr->rad[0], msg->msg[0]);
4018 : goto out_clear_reply;
4019 : }
4020 :
4021 0 : drm_dp_sideband_parse_reply(mgr, msg, &txmsg->reply);
4022 :
4023 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
4024 0 : drm_dbg_kms(mgr->dev,
4025 : "Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
4026 : txmsg->reply.req_type,
4027 : drm_dp_mst_req_type_str(txmsg->reply.req_type),
4028 : txmsg->reply.u.nak.reason,
4029 : drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason),
4030 : txmsg->reply.u.nak.nak_data);
4031 : }
4032 :
4033 0 : memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
4034 0 : drm_dp_mst_topology_put_mstb(mstb);
4035 :
4036 0 : mutex_lock(&mgr->qlock);
4037 0 : txmsg->state = DRM_DP_SIDEBAND_TX_RX;
4038 0 : list_del(&txmsg->next);
4039 0 : mutex_unlock(&mgr->qlock);
4040 :
4041 0 : wake_up_all(&mgr->tx_waitq);
4042 :
4043 0 : return 0;
4044 :
4045 : out_clear_reply:
4046 0 : memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
4047 : out:
4048 0 : if (mstb)
4049 0 : drm_dp_mst_topology_put_mstb(mstb);
4050 :
4051 : return 0;
4052 : }
4053 :
4054 : static inline bool
4055 0 : drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
4056 : struct drm_dp_pending_up_req *up_req)
4057 : {
4058 0 : struct drm_dp_mst_branch *mstb = NULL;
4059 0 : struct drm_dp_sideband_msg_req_body *msg = &up_req->msg;
4060 0 : struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr;
4061 0 : bool hotplug = false;
4062 :
4063 0 : if (hdr->broadcast) {
4064 0 : const u8 *guid = NULL;
4065 :
4066 0 : if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY)
4067 0 : guid = msg->u.conn_stat.guid;
4068 0 : else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
4069 0 : guid = msg->u.resource_stat.guid;
4070 :
4071 0 : if (guid)
4072 0 : mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
4073 : } else {
4074 0 : mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
4075 : }
4076 :
4077 0 : if (!mstb) {
4078 0 : drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr->lct);
4079 0 : return false;
4080 : }
4081 :
4082 : /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */
4083 0 : if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) {
4084 0 : drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat);
4085 0 : hotplug = true;
4086 : }
4087 :
4088 0 : drm_dp_mst_topology_put_mstb(mstb);
4089 0 : return hotplug;
4090 : }
4091 :
4092 0 : static void drm_dp_mst_up_req_work(struct work_struct *work)
4093 : {
4094 0 : struct drm_dp_mst_topology_mgr *mgr =
4095 0 : container_of(work, struct drm_dp_mst_topology_mgr,
4096 : up_req_work);
4097 : struct drm_dp_pending_up_req *up_req;
4098 0 : bool send_hotplug = false;
4099 :
4100 0 : mutex_lock(&mgr->probe_lock);
4101 : while (true) {
4102 0 : mutex_lock(&mgr->up_req_lock);
4103 0 : up_req = list_first_entry_or_null(&mgr->up_req_list,
4104 : struct drm_dp_pending_up_req,
4105 : next);
4106 0 : if (up_req)
4107 0 : list_del(&up_req->next);
4108 0 : mutex_unlock(&mgr->up_req_lock);
4109 :
4110 0 : if (!up_req)
4111 : break;
4112 :
4113 0 : send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req);
4114 0 : kfree(up_req);
4115 : }
4116 0 : mutex_unlock(&mgr->probe_lock);
4117 :
4118 0 : if (send_hotplug)
4119 0 : drm_kms_helper_hotplug_event(mgr->dev);
4120 0 : }
4121 :
4122 0 : static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
4123 : {
4124 : struct drm_dp_pending_up_req *up_req;
4125 :
4126 0 : if (!drm_dp_get_one_sb_msg(mgr, true, NULL))
4127 : goto out;
4128 :
4129 0 : if (!mgr->up_req_recv.have_eomt)
4130 : return 0;
4131 :
4132 0 : up_req = kzalloc(sizeof(*up_req), GFP_KERNEL);
4133 0 : if (!up_req)
4134 : return -ENOMEM;
4135 :
4136 0 : INIT_LIST_HEAD(&up_req->next);
4137 :
4138 0 : drm_dp_sideband_parse_req(mgr, &mgr->up_req_recv, &up_req->msg);
4139 :
4140 0 : if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY &&
4141 : up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) {
4142 0 : drm_dbg_kms(mgr->dev, "Received unknown up req type, ignoring: %x\n",
4143 : up_req->msg.req_type);
4144 0 : kfree(up_req);
4145 0 : goto out;
4146 : }
4147 :
4148 0 : drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type,
4149 : false);
4150 :
4151 0 : if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
4152 0 : const struct drm_dp_connection_status_notify *conn_stat =
4153 : &up_req->msg.u.conn_stat;
4154 :
4155 0 : drm_dbg_kms(mgr->dev, "Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
4156 : conn_stat->port_number,
4157 : conn_stat->legacy_device_plug_status,
4158 : conn_stat->displayport_device_plug_status,
4159 : conn_stat->message_capability_status,
4160 : conn_stat->input_port,
4161 : conn_stat->peer_device_type);
4162 0 : } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
4163 0 : const struct drm_dp_resource_status_notify *res_stat =
4164 : &up_req->msg.u.resource_stat;
4165 :
4166 0 : drm_dbg_kms(mgr->dev, "Got RSN: pn: %d avail_pbn %d\n",
4167 : res_stat->port_number,
4168 : res_stat->available_pbn);
4169 : }
4170 :
4171 0 : up_req->hdr = mgr->up_req_recv.initial_hdr;
4172 0 : mutex_lock(&mgr->up_req_lock);
4173 0 : list_add_tail(&up_req->next, &mgr->up_req_list);
4174 0 : mutex_unlock(&mgr->up_req_lock);
4175 0 : queue_work(system_long_wq, &mgr->up_req_work);
4176 :
4177 : out:
4178 0 : memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
4179 0 : return 0;
4180 : }
4181 :
4182 : /**
4183 : * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
4184 : * @mgr: manager to notify irq for.
4185 : * @esi: 4 bytes from SINK_COUNT_ESI
4186 : * @handled: whether the hpd interrupt was consumed or not
4187 : *
4188 : * This should be called from the driver when it detects a short IRQ,
4189 : * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
4190 : * topology manager will process the sideband messages received as a result
4191 : * of this.
4192 : */
4193 0 : int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
4194 : {
4195 0 : int ret = 0;
4196 : int sc;
4197 0 : *handled = false;
4198 0 : sc = DP_GET_SINK_COUNT(esi[0]);
4199 :
4200 0 : if (sc != mgr->sink_count) {
4201 0 : mgr->sink_count = sc;
4202 0 : *handled = true;
4203 : }
4204 :
4205 0 : if (esi[1] & DP_DOWN_REP_MSG_RDY) {
4206 0 : ret = drm_dp_mst_handle_down_rep(mgr);
4207 0 : *handled = true;
4208 : }
4209 :
4210 0 : if (esi[1] & DP_UP_REQ_MSG_RDY) {
4211 0 : ret |= drm_dp_mst_handle_up_req(mgr);
4212 0 : *handled = true;
4213 : }
4214 :
4215 0 : drm_dp_mst_kick_tx(mgr);
4216 0 : return ret;
4217 : }
4218 : EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
4219 :
4220 : /**
4221 : * drm_dp_mst_detect_port() - get connection status for an MST port
4222 : * @connector: DRM connector for this port
4223 : * @ctx: The acquisition context to use for grabbing locks
4224 : * @mgr: manager for this port
4225 : * @port: pointer to a port
4226 : *
4227 : * This returns the current connection state for a port.
4228 : */
4229 : int
4230 0 : drm_dp_mst_detect_port(struct drm_connector *connector,
4231 : struct drm_modeset_acquire_ctx *ctx,
4232 : struct drm_dp_mst_topology_mgr *mgr,
4233 : struct drm_dp_mst_port *port)
4234 : {
4235 : int ret;
4236 :
4237 : /* we need to search for the port in the mgr in case it's gone */
4238 0 : port = drm_dp_mst_topology_get_port_validated(mgr, port);
4239 0 : if (!port)
4240 : return connector_status_disconnected;
4241 :
4242 0 : ret = drm_modeset_lock(&mgr->base.lock, ctx);
4243 0 : if (ret)
4244 : goto out;
4245 :
4246 0 : ret = connector_status_disconnected;
4247 :
4248 0 : if (!port->ddps)
4249 : goto out;
4250 :
4251 0 : switch (port->pdt) {
4252 : case DP_PEER_DEVICE_NONE:
4253 : break;
4254 : case DP_PEER_DEVICE_MST_BRANCHING:
4255 0 : if (!port->mcs)
4256 0 : ret = connector_status_connected;
4257 : break;
4258 :
4259 : case DP_PEER_DEVICE_SST_SINK:
4260 0 : ret = connector_status_connected;
4261 : /* for logical ports - cache the EDID */
4262 0 : if (port->port_num >= DP_MST_LOGICAL_PORT_0 && !port->cached_edid)
4263 0 : port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
4264 : break;
4265 : case DP_PEER_DEVICE_DP_LEGACY_CONV:
4266 0 : if (port->ldps)
4267 0 : ret = connector_status_connected;
4268 : break;
4269 : }
4270 : out:
4271 0 : drm_dp_mst_topology_put_port(port);
4272 0 : return ret;
4273 : }
4274 : EXPORT_SYMBOL(drm_dp_mst_detect_port);
4275 :
4276 : /**
4277 : * drm_dp_mst_get_edid() - get EDID for an MST port
4278 : * @connector: toplevel connector to get EDID for
4279 : * @mgr: manager for this port
4280 : * @port: unverified pointer to a port.
4281 : *
4282 : * This returns an EDID for the port connected to a connector,
4283 : * It validates the pointer still exists so the caller doesn't require a
4284 : * reference.
4285 : */
4286 0 : struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4287 : {
4288 0 : struct edid *edid = NULL;
4289 :
4290 : /* we need to search for the port in the mgr in case it's gone */
4291 0 : port = drm_dp_mst_topology_get_port_validated(mgr, port);
4292 0 : if (!port)
4293 : return NULL;
4294 :
4295 0 : if (port->cached_edid)
4296 0 : edid = drm_edid_duplicate(port->cached_edid);
4297 : else {
4298 0 : edid = drm_get_edid(connector, &port->aux.ddc);
4299 : }
4300 0 : port->has_audio = drm_detect_monitor_audio(edid);
4301 0 : drm_dp_mst_topology_put_port(port);
4302 0 : return edid;
4303 : }
4304 : EXPORT_SYMBOL(drm_dp_mst_get_edid);
4305 :
4306 : /**
4307 : * drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
4308 : * @mgr: manager to use
4309 : * @pbn: payload bandwidth to convert into slots.
4310 : *
4311 : * Calculate the number of VCPI slots that will be required for the given PBN
4312 : * value. This function is deprecated, and should not be used in atomic
4313 : * drivers.
4314 : *
4315 : * RETURNS:
4316 : * The total slots required for this port, or error.
4317 : */
4318 0 : int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
4319 : int pbn)
4320 : {
4321 : int num_slots;
4322 :
4323 0 : num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
4324 :
4325 : /* max. time slots - one slot for MTP header */
4326 0 : if (num_slots > 63)
4327 : return -ENOSPC;
4328 0 : return num_slots;
4329 : }
4330 : EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
4331 :
4332 : static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4333 : struct drm_dp_vcpi *vcpi, int pbn, int slots)
4334 : {
4335 : int ret;
4336 :
4337 0 : vcpi->pbn = pbn;
4338 0 : vcpi->aligned_pbn = slots * mgr->pbn_div;
4339 0 : vcpi->num_slots = slots;
4340 :
4341 0 : ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
4342 0 : if (ret < 0)
4343 : return ret;
4344 : return 0;
4345 : }
4346 :
4347 : /**
4348 : * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
4349 : * @state: global atomic state
4350 : * @mgr: MST topology manager for the port
4351 : * @port: port to find vcpi slots for
4352 : * @pbn: bandwidth required for the mode in PBN
4353 : * @pbn_div: divider for DSC mode that takes FEC into account
4354 : *
4355 : * Allocates VCPI slots to @port, replacing any previous VCPI allocations it
4356 : * may have had. Any atomic drivers which support MST must call this function
4357 : * in their &drm_encoder_helper_funcs.atomic_check() callback to change the
4358 : * current VCPI allocation for the new state, but only when
4359 : * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set
4360 : * to ensure compatibility with userspace applications that still use the
4361 : * legacy modesetting UAPI.
4362 : *
4363 : * Allocations set by this function are not checked against the bandwidth
4364 : * restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
4365 : *
4366 : * Additionally, it is OK to call this function multiple times on the same
4367 : * @port as needed. It is not OK however, to call this function and
4368 : * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
4369 : *
4370 : * See also:
4371 : * drm_dp_atomic_release_vcpi_slots()
4372 : * drm_dp_mst_atomic_check()
4373 : *
4374 : * Returns:
4375 : * Total slots in the atomic state assigned for this port, or a negative error
4376 : * code if the port no longer exists
4377 : */
4378 0 : int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
4379 : struct drm_dp_mst_topology_mgr *mgr,
4380 : struct drm_dp_mst_port *port, int pbn,
4381 : int pbn_div)
4382 : {
4383 : struct drm_dp_mst_topology_state *topology_state;
4384 0 : struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
4385 : int prev_slots, prev_bw, req_slots;
4386 :
4387 0 : topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4388 0 : if (IS_ERR(topology_state))
4389 0 : return PTR_ERR(topology_state);
4390 :
4391 : /* Find the current allocation for this port, if any */
4392 0 : list_for_each_entry(pos, &topology_state->vcpis, next) {
4393 0 : if (pos->port == port) {
4394 0 : vcpi = pos;
4395 0 : prev_slots = vcpi->vcpi;
4396 0 : prev_bw = vcpi->pbn;
4397 :
4398 : /*
4399 : * This should never happen, unless the driver tries
4400 : * releasing and allocating the same VCPI allocation,
4401 : * which is an error
4402 : */
4403 0 : if (WARN_ON(!prev_slots)) {
4404 0 : drm_err(mgr->dev,
4405 : "cannot allocate and release VCPI on [MST PORT:%p] in the same state\n",
4406 : port);
4407 0 : return -EINVAL;
4408 : }
4409 :
4410 : break;
4411 : }
4412 : }
4413 0 : if (!vcpi) {
4414 0 : prev_slots = 0;
4415 0 : prev_bw = 0;
4416 : }
4417 :
4418 0 : if (pbn_div <= 0)
4419 0 : pbn_div = mgr->pbn_div;
4420 :
4421 0 : req_slots = DIV_ROUND_UP(pbn, pbn_div);
4422 :
4423 0 : drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
4424 : port->connector->base.id, port->connector->name,
4425 : port, prev_slots, req_slots);
4426 0 : drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n",
4427 : port->connector->base.id, port->connector->name,
4428 : port, prev_bw, pbn);
4429 :
4430 : /* Add the new allocation to the state */
4431 0 : if (!vcpi) {
4432 0 : vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL);
4433 0 : if (!vcpi)
4434 : return -ENOMEM;
4435 :
4436 0 : drm_dp_mst_get_port_malloc(port);
4437 0 : vcpi->port = port;
4438 0 : list_add(&vcpi->next, &topology_state->vcpis);
4439 : }
4440 0 : vcpi->vcpi = req_slots;
4441 0 : vcpi->pbn = pbn;
4442 :
4443 0 : return req_slots;
4444 : }
4445 : EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
4446 :
4447 : /**
4448 : * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
4449 : * @state: global atomic state
4450 : * @mgr: MST topology manager for the port
4451 : * @port: The port to release the VCPI slots from
4452 : *
4453 : * Releases any VCPI slots that have been allocated to a port in the atomic
4454 : * state. Any atomic drivers which support MST must call this function in
4455 : * their &drm_connector_helper_funcs.atomic_check() callback when the
4456 : * connector will no longer have VCPI allocated (e.g. because its CRTC was
4457 : * removed) when it had VCPI allocated in the previous atomic state.
4458 : *
4459 : * It is OK to call this even if @port has been removed from the system.
4460 : * Additionally, it is OK to call this function multiple times on the same
4461 : * @port as needed. It is not OK however, to call this function and
4462 : * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
4463 : * phase.
4464 : *
4465 : * See also:
4466 : * drm_dp_atomic_find_vcpi_slots()
4467 : * drm_dp_mst_atomic_check()
4468 : *
4469 : * Returns:
4470 : * 0 if all slots for this port were added back to
4471 : * &drm_dp_mst_topology_state.avail_slots or negative error code
4472 : */
4473 0 : int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
4474 : struct drm_dp_mst_topology_mgr *mgr,
4475 : struct drm_dp_mst_port *port)
4476 : {
4477 : struct drm_dp_mst_topology_state *topology_state;
4478 : struct drm_dp_vcpi_allocation *pos;
4479 0 : bool found = false;
4480 :
4481 0 : topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4482 0 : if (IS_ERR(topology_state))
4483 0 : return PTR_ERR(topology_state);
4484 :
4485 0 : list_for_each_entry(pos, &topology_state->vcpis, next) {
4486 0 : if (pos->port == port) {
4487 : found = true;
4488 : break;
4489 : }
4490 : }
4491 0 : if (WARN_ON(!found)) {
4492 0 : drm_err(mgr->dev, "no VCPI for [MST PORT:%p] found in mst state %p\n",
4493 : port, &topology_state->base);
4494 0 : return -EINVAL;
4495 : }
4496 :
4497 0 : drm_dbg_atomic(mgr->dev, "[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi);
4498 0 : if (pos->vcpi) {
4499 0 : drm_dp_mst_put_port_malloc(port);
4500 0 : pos->vcpi = 0;
4501 0 : pos->pbn = 0;
4502 : }
4503 :
4504 : return 0;
4505 : }
4506 : EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
4507 :
4508 : /**
4509 : * drm_dp_mst_update_slots() - updates the slot info depending on the DP ecoding format
4510 : * @mst_state: mst_state to update
4511 : * @link_encoding_cap: the ecoding format on the link
4512 : */
4513 0 : void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap)
4514 : {
4515 0 : if (link_encoding_cap == DP_CAP_ANSI_128B132B) {
4516 0 : mst_state->total_avail_slots = 64;
4517 0 : mst_state->start_slot = 0;
4518 : } else {
4519 0 : mst_state->total_avail_slots = 63;
4520 0 : mst_state->start_slot = 1;
4521 : }
4522 :
4523 0 : DRM_DEBUG_KMS("%s encoding format on mst_state 0x%p\n",
4524 : (link_encoding_cap == DP_CAP_ANSI_128B132B) ? "128b/132b":"8b/10b",
4525 : mst_state);
4526 0 : }
4527 : EXPORT_SYMBOL(drm_dp_mst_update_slots);
4528 :
4529 : /**
4530 : * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
4531 : * @mgr: manager for this port
4532 : * @port: port to allocate a virtual channel for.
4533 : * @pbn: payload bandwidth number to request
4534 : * @slots: returned number of slots for this PBN.
4535 : */
4536 0 : bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4537 : struct drm_dp_mst_port *port, int pbn, int slots)
4538 : {
4539 : int ret;
4540 :
4541 0 : if (slots < 0)
4542 : return false;
4543 :
4544 0 : port = drm_dp_mst_topology_get_port_validated(mgr, port);
4545 0 : if (!port)
4546 : return false;
4547 :
4548 0 : if (port->vcpi.vcpi > 0) {
4549 0 : drm_dbg_kms(mgr->dev,
4550 : "payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
4551 : port->vcpi.vcpi, port->vcpi.pbn, pbn);
4552 0 : if (pbn == port->vcpi.pbn) {
4553 0 : drm_dp_mst_topology_put_port(port);
4554 0 : return true;
4555 : }
4556 : }
4557 :
4558 0 : ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
4559 0 : if (ret) {
4560 0 : drm_dbg_kms(mgr->dev, "failed to init vcpi slots=%d ret=%d\n",
4561 : DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
4562 0 : drm_dp_mst_topology_put_port(port);
4563 : goto out;
4564 : }
4565 0 : drm_dbg_kms(mgr->dev, "initing vcpi for pbn=%d slots=%d\n", pbn, port->vcpi.num_slots);
4566 :
4567 : /* Keep port allocated until its payload has been removed */
4568 0 : drm_dp_mst_get_port_malloc(port);
4569 0 : drm_dp_mst_topology_put_port(port);
4570 0 : return true;
4571 : out:
4572 0 : return false;
4573 : }
4574 : EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
4575 :
4576 0 : int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4577 : {
4578 0 : int slots = 0;
4579 :
4580 0 : port = drm_dp_mst_topology_get_port_validated(mgr, port);
4581 0 : if (!port)
4582 : return slots;
4583 :
4584 0 : slots = port->vcpi.num_slots;
4585 0 : drm_dp_mst_topology_put_port(port);
4586 0 : return slots;
4587 : }
4588 : EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
4589 :
4590 : /**
4591 : * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
4592 : * @mgr: manager for this port
4593 : * @port: unverified pointer to a port.
4594 : *
4595 : * This just resets the number of slots for the ports VCPI for later programming.
4596 : */
4597 0 : void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4598 : {
4599 : /*
4600 : * A port with VCPI will remain allocated until its VCPI is
4601 : * released, no verified ref needed
4602 : */
4603 :
4604 0 : port->vcpi.num_slots = 0;
4605 0 : }
4606 : EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
4607 :
4608 : /**
4609 : * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
4610 : * @mgr: manager for this port
4611 : * @port: port to deallocate vcpi for
4612 : *
4613 : * This can be called unconditionally, regardless of whether
4614 : * drm_dp_mst_allocate_vcpi() succeeded or not.
4615 : */
4616 0 : void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4617 : struct drm_dp_mst_port *port)
4618 : {
4619 : bool skip;
4620 :
4621 0 : if (!port->vcpi.vcpi)
4622 : return;
4623 :
4624 0 : mutex_lock(&mgr->lock);
4625 0 : skip = !drm_dp_mst_port_downstream_of_branch(port, mgr->mst_primary);
4626 0 : mutex_unlock(&mgr->lock);
4627 :
4628 0 : if (skip)
4629 : return;
4630 :
4631 0 : drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
4632 0 : port->vcpi.num_slots = 0;
4633 0 : port->vcpi.pbn = 0;
4634 0 : port->vcpi.aligned_pbn = 0;
4635 0 : port->vcpi.vcpi = 0;
4636 0 : drm_dp_mst_put_port_malloc(port);
4637 : }
4638 : EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
4639 :
4640 0 : static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
4641 : int id, struct drm_dp_payload *payload)
4642 : {
4643 : u8 payload_alloc[3], status;
4644 : int ret;
4645 0 : int retries = 0;
4646 :
4647 0 : drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
4648 : DP_PAYLOAD_TABLE_UPDATED);
4649 :
4650 0 : payload_alloc[0] = id;
4651 0 : payload_alloc[1] = payload->start_slot;
4652 0 : payload_alloc[2] = payload->num_slots;
4653 :
4654 0 : ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
4655 0 : if (ret != 3) {
4656 0 : drm_dbg_kms(mgr->dev, "failed to write payload allocation %d\n", ret);
4657 : goto fail;
4658 : }
4659 :
4660 : retry:
4661 0 : ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4662 0 : if (ret < 0) {
4663 0 : drm_dbg_kms(mgr->dev, "failed to read payload table status %d\n", ret);
4664 : goto fail;
4665 : }
4666 :
4667 0 : if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
4668 0 : retries++;
4669 0 : if (retries < 20) {
4670 : usleep_range(10000, 20000);
4671 : goto retry;
4672 : }
4673 0 : drm_dbg_kms(mgr->dev, "status not set after read payload table status %d\n",
4674 : status);
4675 0 : ret = -EINVAL;
4676 : goto fail;
4677 : }
4678 : ret = 0;
4679 : fail:
4680 0 : return ret;
4681 : }
4682 :
4683 : static int do_get_act_status(struct drm_dp_aux *aux)
4684 : {
4685 : int ret;
4686 : u8 status;
4687 :
4688 0 : ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4689 0 : if (ret < 0)
4690 : return ret;
4691 :
4692 0 : return status;
4693 : }
4694 :
4695 : /**
4696 : * drm_dp_check_act_status() - Polls for ACT handled status.
4697 : * @mgr: manager to use
4698 : *
4699 : * Tries waiting for the MST hub to finish updating it's payload table by
4700 : * polling for the ACT handled bit for up to 3 seconds (yes-some hubs really
4701 : * take that long).
4702 : *
4703 : * Returns:
4704 : * 0 if the ACT was handled in time, negative error code on failure.
4705 : */
4706 0 : int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
4707 : {
4708 : /*
4709 : * There doesn't seem to be any recommended retry count or timeout in
4710 : * the MST specification. Since some hubs have been observed to take
4711 : * over 1 second to update their payload allocations under certain
4712 : * conditions, we use a rather large timeout value.
4713 : */
4714 0 : const int timeout_ms = 3000;
4715 : int ret, status;
4716 :
4717 0 : ret = readx_poll_timeout(do_get_act_status, mgr->aux, status,
4718 : status & DP_PAYLOAD_ACT_HANDLED || status < 0,
4719 : 200, timeout_ms * USEC_PER_MSEC);
4720 0 : if (ret < 0 && status >= 0) {
4721 0 : drm_err(mgr->dev, "Failed to get ACT after %dms, last status: %02x\n",
4722 : timeout_ms, status);
4723 0 : return -EINVAL;
4724 0 : } else if (status < 0) {
4725 : /*
4726 : * Failure here isn't unexpected - the hub may have
4727 : * just been unplugged
4728 : */
4729 0 : drm_dbg_kms(mgr->dev, "Failed to read payload table status: %d\n", status);
4730 0 : return status;
4731 : }
4732 :
4733 : return 0;
4734 : }
4735 : EXPORT_SYMBOL(drm_dp_check_act_status);
4736 :
4737 : /**
4738 : * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
4739 : * @clock: dot clock for the mode
4740 : * @bpp: bpp for the mode.
4741 : * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel
4742 : *
4743 : * This uses the formula in the spec to calculate the PBN value for a mode.
4744 : */
4745 0 : int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc)
4746 : {
4747 : /*
4748 : * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
4749 : * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
4750 : * common multiplier to render an integer PBN for all link rate/lane
4751 : * counts combinations
4752 : * calculate
4753 : * peak_kbps *= (1006/1000)
4754 : * peak_kbps *= (64/54)
4755 : * peak_kbps *= 8 convert to bytes
4756 : *
4757 : * If the bpp is in units of 1/16, further divide by 16. Put this
4758 : * factor in the numerator rather than the denominator to avoid
4759 : * integer overflow
4760 : */
4761 :
4762 0 : if (dsc)
4763 0 : return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006),
4764 : 8 * 54 * 1000 * 1000);
4765 :
4766 0 : return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
4767 : 8 * 54 * 1000 * 1000);
4768 : }
4769 : EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
4770 :
4771 : /* we want to kick the TX after we've ack the up/down IRQs. */
4772 : static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
4773 : {
4774 0 : queue_work(system_long_wq, &mgr->tx_work);
4775 : }
4776 :
4777 : /*
4778 : * Helper function for parsing DP device types into convenient strings
4779 : * for use with dp_mst_topology
4780 : */
4781 : static const char *pdt_to_string(u8 pdt)
4782 : {
4783 : switch (pdt) {
4784 : case DP_PEER_DEVICE_NONE:
4785 : return "NONE";
4786 : case DP_PEER_DEVICE_SOURCE_OR_SST:
4787 : return "SOURCE OR SST";
4788 : case DP_PEER_DEVICE_MST_BRANCHING:
4789 : return "MST BRANCHING";
4790 : case DP_PEER_DEVICE_SST_SINK:
4791 : return "SST SINK";
4792 : case DP_PEER_DEVICE_DP_LEGACY_CONV:
4793 : return "DP LEGACY CONV";
4794 : default:
4795 : return "ERR";
4796 : }
4797 : }
4798 :
4799 0 : static void drm_dp_mst_dump_mstb(struct seq_file *m,
4800 : struct drm_dp_mst_branch *mstb)
4801 : {
4802 : struct drm_dp_mst_port *port;
4803 0 : int tabs = mstb->lct;
4804 : char prefix[10];
4805 : int i;
4806 :
4807 0 : for (i = 0; i < tabs; i++)
4808 0 : prefix[i] = '\t';
4809 0 : prefix[i] = '\0';
4810 :
4811 0 : seq_printf(m, "%smstb - [%p]: num_ports: %d\n", prefix, mstb, mstb->num_ports);
4812 0 : list_for_each_entry(port, &mstb->ports, next) {
4813 0 : seq_printf(m, "%sport %d - [%p] (%s - %s): ddps: %d, ldps: %d, sdp: %d/%d, fec: %s, conn: %p\n",
4814 : prefix,
4815 0 : port->port_num,
4816 : port,
4817 0 : port->input ? "input" : "output",
4818 0 : pdt_to_string(port->pdt),
4819 0 : port->ddps,
4820 0 : port->ldps,
4821 0 : port->num_sdp_streams,
4822 0 : port->num_sdp_stream_sinks,
4823 0 : port->fec_capable ? "true" : "false",
4824 : port->connector);
4825 0 : if (port->mstb)
4826 0 : drm_dp_mst_dump_mstb(m, port->mstb);
4827 : }
4828 0 : }
4829 :
4830 : #define DP_PAYLOAD_TABLE_SIZE 64
4831 :
4832 0 : static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
4833 : char *buf)
4834 : {
4835 : int i;
4836 :
4837 0 : for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
4838 0 : if (drm_dp_dpcd_read(mgr->aux,
4839 0 : DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
4840 0 : &buf[i], 16) != 16)
4841 : return false;
4842 : }
4843 : return true;
4844 : }
4845 :
4846 0 : static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
4847 : struct drm_dp_mst_port *port, char *name,
4848 : int namelen)
4849 : {
4850 : struct edid *mst_edid;
4851 :
4852 0 : mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
4853 0 : drm_edid_get_monitor_name(mst_edid, name, namelen);
4854 0 : kfree(mst_edid);
4855 0 : }
4856 :
4857 : /**
4858 : * drm_dp_mst_dump_topology(): dump topology to seq file.
4859 : * @m: seq_file to dump output to
4860 : * @mgr: manager to dump current topology for.
4861 : *
4862 : * helper to dump MST topology to a seq file for debugfs.
4863 : */
4864 0 : void drm_dp_mst_dump_topology(struct seq_file *m,
4865 : struct drm_dp_mst_topology_mgr *mgr)
4866 : {
4867 : int i;
4868 : struct drm_dp_mst_port *port;
4869 :
4870 0 : mutex_lock(&mgr->lock);
4871 0 : if (mgr->mst_primary)
4872 0 : drm_dp_mst_dump_mstb(m, mgr->mst_primary);
4873 :
4874 : /* dump VCPIs */
4875 0 : mutex_unlock(&mgr->lock);
4876 :
4877 0 : mutex_lock(&mgr->payload_lock);
4878 0 : seq_printf(m, "\n*** VCPI Info ***\n");
4879 0 : seq_printf(m, "payload_mask: %lx, vcpi_mask: %lx, max_payloads: %d\n", mgr->payload_mask, mgr->vcpi_mask, mgr->max_payloads);
4880 :
4881 0 : seq_printf(m, "\n| idx | port # | vcp_id | # slots | sink name |\n");
4882 0 : for (i = 0; i < mgr->max_payloads; i++) {
4883 0 : if (mgr->proposed_vcpis[i]) {
4884 : char name[14];
4885 :
4886 0 : port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
4887 0 : fetch_monitor_name(mgr, port, name, sizeof(name));
4888 0 : seq_printf(m, "%10d%10d%10d%10d%20s\n",
4889 : i,
4890 0 : port->port_num,
4891 : port->vcpi.vcpi,
4892 : port->vcpi.num_slots,
4893 0 : (*name != 0) ? name : "Unknown");
4894 : } else
4895 0 : seq_printf(m, "%6d - Unused\n", i);
4896 : }
4897 0 : seq_printf(m, "\n*** Payload Info ***\n");
4898 0 : seq_printf(m, "| idx | state | start slot | # slots |\n");
4899 0 : for (i = 0; i < mgr->max_payloads; i++) {
4900 0 : seq_printf(m, "%10d%10d%15d%10d\n",
4901 : i,
4902 : mgr->payloads[i].payload_state,
4903 : mgr->payloads[i].start_slot,
4904 0 : mgr->payloads[i].num_slots);
4905 : }
4906 0 : mutex_unlock(&mgr->payload_lock);
4907 :
4908 0 : seq_printf(m, "\n*** DPCD Info ***\n");
4909 0 : mutex_lock(&mgr->lock);
4910 0 : if (mgr->mst_primary) {
4911 : u8 buf[DP_PAYLOAD_TABLE_SIZE];
4912 : int ret;
4913 :
4914 0 : ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
4915 0 : if (ret) {
4916 0 : seq_printf(m, "dpcd read failed\n");
4917 0 : goto out;
4918 : }
4919 0 : seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
4920 :
4921 0 : ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
4922 0 : if (ret) {
4923 0 : seq_printf(m, "faux/mst read failed\n");
4924 0 : goto out;
4925 : }
4926 0 : seq_printf(m, "faux/mst: %*ph\n", 2, buf);
4927 :
4928 0 : ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
4929 0 : if (ret) {
4930 0 : seq_printf(m, "mst ctrl read failed\n");
4931 0 : goto out;
4932 : }
4933 0 : seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
4934 :
4935 : /* dump the standard OUI branch header */
4936 0 : ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
4937 0 : if (ret) {
4938 0 : seq_printf(m, "branch oui read failed\n");
4939 0 : goto out;
4940 : }
4941 0 : seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
4942 :
4943 0 : for (i = 0x3; i < 0x8 && buf[i]; i++)
4944 0 : seq_printf(m, "%c", buf[i]);
4945 0 : seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
4946 0 : buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
4947 0 : if (dump_dp_payload_table(mgr, buf))
4948 0 : seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
4949 : }
4950 :
4951 : out:
4952 0 : mutex_unlock(&mgr->lock);
4953 :
4954 0 : }
4955 : EXPORT_SYMBOL(drm_dp_mst_dump_topology);
4956 :
4957 0 : static void drm_dp_tx_work(struct work_struct *work)
4958 : {
4959 0 : struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
4960 :
4961 0 : mutex_lock(&mgr->qlock);
4962 0 : if (!list_empty(&mgr->tx_msg_downq))
4963 0 : process_single_down_tx_qlock(mgr);
4964 0 : mutex_unlock(&mgr->qlock);
4965 0 : }
4966 :
4967 : static inline void
4968 0 : drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port)
4969 : {
4970 0 : drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs);
4971 :
4972 0 : if (port->connector) {
4973 0 : drm_connector_unregister(port->connector);
4974 0 : drm_connector_put(port->connector);
4975 : }
4976 :
4977 0 : drm_dp_mst_put_port_malloc(port);
4978 0 : }
4979 :
4980 : static inline void
4981 0 : drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb)
4982 : {
4983 0 : struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
4984 : struct drm_dp_mst_port *port, *port_tmp;
4985 : struct drm_dp_sideband_msg_tx *txmsg, *txmsg_tmp;
4986 0 : bool wake_tx = false;
4987 :
4988 0 : mutex_lock(&mgr->lock);
4989 0 : list_for_each_entry_safe(port, port_tmp, &mstb->ports, next) {
4990 0 : list_del(&port->next);
4991 0 : drm_dp_mst_topology_put_port(port);
4992 : }
4993 0 : mutex_unlock(&mgr->lock);
4994 :
4995 : /* drop any tx slot msg */
4996 0 : mutex_lock(&mstb->mgr->qlock);
4997 0 : list_for_each_entry_safe(txmsg, txmsg_tmp, &mgr->tx_msg_downq, next) {
4998 0 : if (txmsg->dst != mstb)
4999 0 : continue;
5000 :
5001 0 : txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
5002 0 : list_del(&txmsg->next);
5003 0 : wake_tx = true;
5004 : }
5005 0 : mutex_unlock(&mstb->mgr->qlock);
5006 :
5007 0 : if (wake_tx)
5008 0 : wake_up_all(&mstb->mgr->tx_waitq);
5009 :
5010 0 : drm_dp_mst_put_mstb_malloc(mstb);
5011 0 : }
5012 :
5013 0 : static void drm_dp_delayed_destroy_work(struct work_struct *work)
5014 : {
5015 0 : struct drm_dp_mst_topology_mgr *mgr =
5016 0 : container_of(work, struct drm_dp_mst_topology_mgr,
5017 : delayed_destroy_work);
5018 0 : bool send_hotplug = false, go_again;
5019 :
5020 : /*
5021 : * Not a regular list traverse as we have to drop the destroy
5022 : * connector lock before destroying the mstb/port, to avoid AB->BA
5023 : * ordering between this lock and the config mutex.
5024 : */
5025 : do {
5026 0 : go_again = false;
5027 :
5028 0 : for (;;) {
5029 : struct drm_dp_mst_branch *mstb;
5030 :
5031 0 : mutex_lock(&mgr->delayed_destroy_lock);
5032 0 : mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list,
5033 : struct drm_dp_mst_branch,
5034 : destroy_next);
5035 0 : if (mstb)
5036 0 : list_del(&mstb->destroy_next);
5037 0 : mutex_unlock(&mgr->delayed_destroy_lock);
5038 :
5039 0 : if (!mstb)
5040 : break;
5041 :
5042 0 : drm_dp_delayed_destroy_mstb(mstb);
5043 0 : go_again = true;
5044 : }
5045 :
5046 0 : for (;;) {
5047 : struct drm_dp_mst_port *port;
5048 :
5049 0 : mutex_lock(&mgr->delayed_destroy_lock);
5050 0 : port = list_first_entry_or_null(&mgr->destroy_port_list,
5051 : struct drm_dp_mst_port,
5052 : next);
5053 0 : if (port)
5054 0 : list_del(&port->next);
5055 0 : mutex_unlock(&mgr->delayed_destroy_lock);
5056 :
5057 0 : if (!port)
5058 : break;
5059 :
5060 0 : drm_dp_delayed_destroy_port(port);
5061 0 : send_hotplug = true;
5062 0 : go_again = true;
5063 : }
5064 0 : } while (go_again);
5065 :
5066 0 : if (send_hotplug)
5067 0 : drm_kms_helper_hotplug_event(mgr->dev);
5068 0 : }
5069 :
5070 : static struct drm_private_state *
5071 0 : drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
5072 : {
5073 0 : struct drm_dp_mst_topology_state *state, *old_state =
5074 0 : to_dp_mst_topology_state(obj->state);
5075 : struct drm_dp_vcpi_allocation *pos, *vcpi;
5076 :
5077 0 : state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
5078 0 : if (!state)
5079 : return NULL;
5080 :
5081 0 : __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
5082 :
5083 0 : INIT_LIST_HEAD(&state->vcpis);
5084 :
5085 0 : list_for_each_entry(pos, &old_state->vcpis, next) {
5086 : /* Prune leftover freed VCPI allocations */
5087 0 : if (!pos->vcpi)
5088 0 : continue;
5089 :
5090 0 : vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL);
5091 0 : if (!vcpi)
5092 : goto fail;
5093 :
5094 0 : drm_dp_mst_get_port_malloc(vcpi->port);
5095 0 : list_add(&vcpi->next, &state->vcpis);
5096 : }
5097 :
5098 : return &state->base;
5099 :
5100 : fail:
5101 0 : list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) {
5102 0 : drm_dp_mst_put_port_malloc(pos->port);
5103 0 : kfree(pos);
5104 : }
5105 0 : kfree(state);
5106 :
5107 0 : return NULL;
5108 : }
5109 :
5110 0 : static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
5111 : struct drm_private_state *state)
5112 : {
5113 0 : struct drm_dp_mst_topology_state *mst_state =
5114 0 : to_dp_mst_topology_state(state);
5115 : struct drm_dp_vcpi_allocation *pos, *tmp;
5116 :
5117 0 : list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) {
5118 : /* We only keep references to ports with non-zero VCPIs */
5119 0 : if (pos->vcpi)
5120 0 : drm_dp_mst_put_port_malloc(pos->port);
5121 0 : kfree(pos);
5122 : }
5123 :
5124 0 : kfree(mst_state);
5125 0 : }
5126 :
5127 : static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
5128 : struct drm_dp_mst_branch *branch)
5129 : {
5130 0 : while (port->parent) {
5131 0 : if (port->parent == branch)
5132 : return true;
5133 :
5134 0 : if (port->parent->port_parent)
5135 : port = port->parent->port_parent;
5136 : else
5137 : break;
5138 : }
5139 : return false;
5140 : }
5141 :
5142 : static int
5143 : drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
5144 : struct drm_dp_mst_topology_state *state);
5145 :
5146 : static int
5147 0 : drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb,
5148 : struct drm_dp_mst_topology_state *state)
5149 : {
5150 : struct drm_dp_vcpi_allocation *vcpi;
5151 : struct drm_dp_mst_port *port;
5152 0 : int pbn_used = 0, ret;
5153 0 : bool found = false;
5154 :
5155 : /* Check that we have at least one port in our state that's downstream
5156 : * of this branch, otherwise we can skip this branch
5157 : */
5158 0 : list_for_each_entry(vcpi, &state->vcpis, next) {
5159 0 : if (!vcpi->pbn ||
5160 0 : !drm_dp_mst_port_downstream_of_branch(vcpi->port, mstb))
5161 0 : continue;
5162 :
5163 : found = true;
5164 : break;
5165 : }
5166 0 : if (!found)
5167 : return 0;
5168 :
5169 0 : if (mstb->port_parent)
5170 0 : drm_dbg_atomic(mstb->mgr->dev,
5171 : "[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n",
5172 : mstb->port_parent->parent, mstb->port_parent, mstb);
5173 : else
5174 0 : drm_dbg_atomic(mstb->mgr->dev, "[MSTB:%p] Checking bandwidth limits\n", mstb);
5175 :
5176 0 : list_for_each_entry(port, &mstb->ports, next) {
5177 0 : ret = drm_dp_mst_atomic_check_port_bw_limit(port, state);
5178 0 : if (ret < 0)
5179 : return ret;
5180 :
5181 0 : pbn_used += ret;
5182 : }
5183 :
5184 : return pbn_used;
5185 : }
5186 :
5187 : static int
5188 0 : drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
5189 : struct drm_dp_mst_topology_state *state)
5190 : {
5191 : struct drm_dp_vcpi_allocation *vcpi;
5192 0 : int pbn_used = 0;
5193 :
5194 0 : if (port->pdt == DP_PEER_DEVICE_NONE)
5195 : return 0;
5196 :
5197 0 : if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
5198 0 : bool found = false;
5199 :
5200 0 : list_for_each_entry(vcpi, &state->vcpis, next) {
5201 0 : if (vcpi->port != port)
5202 0 : continue;
5203 0 : if (!vcpi->pbn)
5204 : return 0;
5205 :
5206 : found = true;
5207 : break;
5208 : }
5209 0 : if (!found)
5210 : return 0;
5211 :
5212 : /*
5213 : * This could happen if the sink deasserted its HPD line, but
5214 : * the branch device still reports it as attached (PDT != NONE).
5215 : */
5216 0 : if (!port->full_pbn) {
5217 0 : drm_dbg_atomic(port->mgr->dev,
5218 : "[MSTB:%p] [MST PORT:%p] no BW available for the port\n",
5219 : port->parent, port);
5220 0 : return -EINVAL;
5221 : }
5222 :
5223 0 : pbn_used = vcpi->pbn;
5224 : } else {
5225 0 : pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb,
5226 : state);
5227 0 : if (pbn_used <= 0)
5228 : return pbn_used;
5229 : }
5230 :
5231 0 : if (pbn_used > port->full_pbn) {
5232 0 : drm_dbg_atomic(port->mgr->dev,
5233 : "[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n",
5234 : port->parent, port, pbn_used, port->full_pbn);
5235 0 : return -ENOSPC;
5236 : }
5237 :
5238 0 : drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n",
5239 : port->parent, port, pbn_used, port->full_pbn);
5240 :
5241 0 : return pbn_used;
5242 : }
5243 :
5244 : static inline int
5245 0 : drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr,
5246 : struct drm_dp_mst_topology_state *mst_state)
5247 : {
5248 : struct drm_dp_vcpi_allocation *vcpi;
5249 0 : int avail_slots = mst_state->total_avail_slots, payload_count = 0;
5250 :
5251 0 : list_for_each_entry(vcpi, &mst_state->vcpis, next) {
5252 : /* Releasing VCPI is always OK-even if the port is gone */
5253 0 : if (!vcpi->vcpi) {
5254 0 : drm_dbg_atomic(mgr->dev, "[MST PORT:%p] releases all VCPI slots\n",
5255 : vcpi->port);
5256 0 : continue;
5257 : }
5258 :
5259 0 : drm_dbg_atomic(mgr->dev, "[MST PORT:%p] requires %d vcpi slots\n",
5260 : vcpi->port, vcpi->vcpi);
5261 :
5262 0 : avail_slots -= vcpi->vcpi;
5263 0 : if (avail_slots < 0) {
5264 0 : drm_dbg_atomic(mgr->dev,
5265 : "[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n",
5266 : vcpi->port, mst_state, avail_slots + vcpi->vcpi);
5267 0 : return -ENOSPC;
5268 : }
5269 :
5270 0 : if (++payload_count > mgr->max_payloads) {
5271 0 : drm_dbg_atomic(mgr->dev,
5272 : "[MST MGR:%p] state %p has too many payloads (max=%d)\n",
5273 : mgr, mst_state, mgr->max_payloads);
5274 0 : return -EINVAL;
5275 : }
5276 : }
5277 0 : drm_dbg_atomic(mgr->dev, "[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
5278 : mgr, mst_state, avail_slots, mst_state->total_avail_slots - avail_slots);
5279 :
5280 0 : return 0;
5281 : }
5282 :
5283 : /**
5284 : * drm_dp_mst_add_affected_dsc_crtcs
5285 : * @state: Pointer to the new struct drm_dp_mst_topology_state
5286 : * @mgr: MST topology manager
5287 : *
5288 : * Whenever there is a change in mst topology
5289 : * DSC configuration would have to be recalculated
5290 : * therefore we need to trigger modeset on all affected
5291 : * CRTCs in that topology
5292 : *
5293 : * See also:
5294 : * drm_dp_mst_atomic_enable_dsc()
5295 : */
5296 0 : int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr)
5297 : {
5298 : struct drm_dp_mst_topology_state *mst_state;
5299 : struct drm_dp_vcpi_allocation *pos;
5300 : struct drm_connector *connector;
5301 : struct drm_connector_state *conn_state;
5302 : struct drm_crtc *crtc;
5303 : struct drm_crtc_state *crtc_state;
5304 :
5305 0 : mst_state = drm_atomic_get_mst_topology_state(state, mgr);
5306 :
5307 0 : if (IS_ERR(mst_state))
5308 : return -EINVAL;
5309 :
5310 0 : list_for_each_entry(pos, &mst_state->vcpis, next) {
5311 :
5312 0 : connector = pos->port->connector;
5313 :
5314 0 : if (!connector)
5315 : return -EINVAL;
5316 :
5317 0 : conn_state = drm_atomic_get_connector_state(state, connector);
5318 :
5319 0 : if (IS_ERR(conn_state))
5320 0 : return PTR_ERR(conn_state);
5321 :
5322 0 : crtc = conn_state->crtc;
5323 :
5324 0 : if (!crtc)
5325 0 : continue;
5326 :
5327 0 : if (!drm_dp_mst_dsc_aux_for_port(pos->port))
5328 0 : continue;
5329 :
5330 0 : crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc);
5331 :
5332 0 : if (IS_ERR(crtc_state))
5333 0 : return PTR_ERR(crtc_state);
5334 :
5335 0 : drm_dbg_atomic(mgr->dev, "[MST MGR:%p] Setting mode_changed flag on CRTC %p\n",
5336 : mgr, crtc);
5337 :
5338 0 : crtc_state->mode_changed = true;
5339 : }
5340 : return 0;
5341 : }
5342 : EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs);
5343 :
5344 : /**
5345 : * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off
5346 : * @state: Pointer to the new drm_atomic_state
5347 : * @port: Pointer to the affected MST Port
5348 : * @pbn: Newly recalculated bw required for link with DSC enabled
5349 : * @pbn_div: Divider to calculate correct number of pbn per slot
5350 : * @enable: Boolean flag to enable or disable DSC on the port
5351 : *
5352 : * This function enables DSC on the given Port
5353 : * by recalculating its vcpi from pbn provided
5354 : * and sets dsc_enable flag to keep track of which
5355 : * ports have DSC enabled
5356 : *
5357 : */
5358 0 : int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
5359 : struct drm_dp_mst_port *port,
5360 : int pbn, int pbn_div,
5361 : bool enable)
5362 : {
5363 : struct drm_dp_mst_topology_state *mst_state;
5364 : struct drm_dp_vcpi_allocation *pos;
5365 0 : bool found = false;
5366 0 : int vcpi = 0;
5367 :
5368 0 : mst_state = drm_atomic_get_mst_topology_state(state, port->mgr);
5369 :
5370 0 : if (IS_ERR(mst_state))
5371 0 : return PTR_ERR(mst_state);
5372 :
5373 0 : list_for_each_entry(pos, &mst_state->vcpis, next) {
5374 0 : if (pos->port == port) {
5375 : found = true;
5376 : break;
5377 : }
5378 : }
5379 :
5380 0 : if (!found) {
5381 0 : drm_dbg_atomic(state->dev,
5382 : "[MST PORT:%p] Couldn't find VCPI allocation in mst state %p\n",
5383 : port, mst_state);
5384 0 : return -EINVAL;
5385 : }
5386 :
5387 0 : if (pos->dsc_enabled == enable) {
5388 0 : drm_dbg_atomic(state->dev,
5389 : "[MST PORT:%p] DSC flag is already set to %d, returning %d VCPI slots\n",
5390 : port, enable, pos->vcpi);
5391 0 : vcpi = pos->vcpi;
5392 : }
5393 :
5394 0 : if (enable) {
5395 0 : vcpi = drm_dp_atomic_find_vcpi_slots(state, port->mgr, port, pbn, pbn_div);
5396 0 : drm_dbg_atomic(state->dev,
5397 : "[MST PORT:%p] Enabling DSC flag, reallocating %d VCPI slots on the port\n",
5398 : port, vcpi);
5399 0 : if (vcpi < 0)
5400 : return -EINVAL;
5401 : }
5402 :
5403 0 : pos->dsc_enabled = enable;
5404 :
5405 0 : return vcpi;
5406 : }
5407 : EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc);
5408 : /**
5409 : * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
5410 : * atomic update is valid
5411 : * @state: Pointer to the new &struct drm_dp_mst_topology_state
5412 : *
5413 : * Checks the given topology state for an atomic update to ensure that it's
5414 : * valid. This includes checking whether there's enough bandwidth to support
5415 : * the new VCPI allocations in the atomic update.
5416 : *
5417 : * Any atomic drivers supporting DP MST must make sure to call this after
5418 : * checking the rest of their state in their
5419 : * &drm_mode_config_funcs.atomic_check() callback.
5420 : *
5421 : * See also:
5422 : * drm_dp_atomic_find_vcpi_slots()
5423 : * drm_dp_atomic_release_vcpi_slots()
5424 : *
5425 : * Returns:
5426 : *
5427 : * 0 if the new state is valid, negative error code otherwise.
5428 : */
5429 0 : int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
5430 : {
5431 : struct drm_dp_mst_topology_mgr *mgr;
5432 : struct drm_dp_mst_topology_state *mst_state;
5433 0 : int i, ret = 0;
5434 :
5435 0 : for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
5436 0 : if (!mgr->mst_state)
5437 0 : continue;
5438 :
5439 0 : ret = drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr, mst_state);
5440 0 : if (ret)
5441 : break;
5442 :
5443 0 : mutex_lock(&mgr->lock);
5444 0 : ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary,
5445 : mst_state);
5446 0 : mutex_unlock(&mgr->lock);
5447 0 : if (ret < 0)
5448 : break;
5449 : else
5450 : ret = 0;
5451 : }
5452 :
5453 0 : return ret;
5454 : }
5455 : EXPORT_SYMBOL(drm_dp_mst_atomic_check);
5456 :
5457 : const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
5458 : .atomic_duplicate_state = drm_dp_mst_duplicate_state,
5459 : .atomic_destroy_state = drm_dp_mst_destroy_state,
5460 : };
5461 : EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
5462 :
5463 : /**
5464 : * drm_atomic_get_mst_topology_state: get MST topology state
5465 : *
5466 : * @state: global atomic state
5467 : * @mgr: MST topology manager, also the private object in this case
5468 : *
5469 : * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
5470 : * state vtable so that the private object state returned is that of a MST
5471 : * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
5472 : * to care of the locking, so warn if don't hold the connection_mutex.
5473 : *
5474 : * RETURNS:
5475 : *
5476 : * The MST topology state or error pointer.
5477 : */
5478 0 : struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
5479 : struct drm_dp_mst_topology_mgr *mgr)
5480 : {
5481 0 : return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
5482 : }
5483 : EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
5484 :
5485 : /**
5486 : * drm_dp_mst_topology_mgr_init - initialise a topology manager
5487 : * @mgr: manager struct to initialise
5488 : * @dev: device providing this structure - for i2c addition.
5489 : * @aux: DP helper aux channel to talk to this device
5490 : * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
5491 : * @max_payloads: maximum number of payloads this GPU can source
5492 : * @max_lane_count: maximum number of lanes this GPU supports
5493 : * @max_link_rate: maximum link rate per lane this GPU supports in kHz
5494 : * @conn_base_id: the connector object ID the MST device is connected to.
5495 : *
5496 : * Return 0 for success, or negative error code on failure
5497 : */
5498 0 : int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
5499 : struct drm_device *dev, struct drm_dp_aux *aux,
5500 : int max_dpcd_transaction_bytes, int max_payloads,
5501 : int max_lane_count, int max_link_rate,
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->payload_lock);
5509 0 : mutex_init(&mgr->delayed_destroy_lock);
5510 0 : mutex_init(&mgr->up_req_lock);
5511 0 : mutex_init(&mgr->probe_lock);
5512 : #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5513 : mutex_init(&mgr->topology_ref_history_lock);
5514 : stack_depot_init();
5515 : #endif
5516 0 : INIT_LIST_HEAD(&mgr->tx_msg_downq);
5517 0 : INIT_LIST_HEAD(&mgr->destroy_port_list);
5518 0 : INIT_LIST_HEAD(&mgr->destroy_branch_device_list);
5519 0 : INIT_LIST_HEAD(&mgr->up_req_list);
5520 :
5521 : /*
5522 : * delayed_destroy_work will be queued on a dedicated WQ, so that any
5523 : * requeuing will be also flushed when deiniting the topology manager.
5524 : */
5525 0 : mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0);
5526 0 : if (mgr->delayed_destroy_wq == NULL)
5527 : return -ENOMEM;
5528 :
5529 0 : INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
5530 0 : INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
5531 0 : INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work);
5532 0 : INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work);
5533 0 : init_waitqueue_head(&mgr->tx_waitq);
5534 0 : mgr->dev = dev;
5535 0 : mgr->aux = aux;
5536 0 : mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
5537 0 : mgr->max_payloads = max_payloads;
5538 0 : mgr->max_lane_count = max_lane_count;
5539 0 : mgr->max_link_rate = max_link_rate;
5540 0 : mgr->conn_base_id = conn_base_id;
5541 0 : if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
5542 : max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
5543 : return -EINVAL;
5544 0 : mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
5545 0 : if (!mgr->payloads)
5546 : return -ENOMEM;
5547 0 : mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
5548 0 : if (!mgr->proposed_vcpis)
5549 : return -ENOMEM;
5550 0 : set_bit(0, &mgr->payload_mask);
5551 :
5552 0 : mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
5553 0 : if (mst_state == NULL)
5554 : return -ENOMEM;
5555 :
5556 0 : mst_state->total_avail_slots = 63;
5557 0 : mst_state->start_slot = 1;
5558 :
5559 0 : mst_state->mgr = mgr;
5560 0 : INIT_LIST_HEAD(&mst_state->vcpis);
5561 :
5562 0 : drm_atomic_private_obj_init(dev, &mgr->base,
5563 : &mst_state->base,
5564 : &drm_dp_mst_topology_state_funcs);
5565 :
5566 0 : return 0;
5567 : }
5568 : EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
5569 :
5570 : /**
5571 : * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
5572 : * @mgr: manager to destroy
5573 : */
5574 0 : void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
5575 : {
5576 0 : drm_dp_mst_topology_mgr_set_mst(mgr, false);
5577 0 : flush_work(&mgr->work);
5578 : /* The following will also drain any requeued work on the WQ. */
5579 0 : if (mgr->delayed_destroy_wq) {
5580 0 : destroy_workqueue(mgr->delayed_destroy_wq);
5581 0 : mgr->delayed_destroy_wq = NULL;
5582 : }
5583 0 : mutex_lock(&mgr->payload_lock);
5584 0 : kfree(mgr->payloads);
5585 0 : mgr->payloads = NULL;
5586 0 : kfree(mgr->proposed_vcpis);
5587 0 : mgr->proposed_vcpis = NULL;
5588 0 : mutex_unlock(&mgr->payload_lock);
5589 0 : mgr->dev = NULL;
5590 0 : mgr->aux = NULL;
5591 0 : drm_atomic_private_obj_fini(&mgr->base);
5592 0 : mgr->funcs = NULL;
5593 :
5594 0 : mutex_destroy(&mgr->delayed_destroy_lock);
5595 0 : mutex_destroy(&mgr->payload_lock);
5596 0 : mutex_destroy(&mgr->qlock);
5597 0 : mutex_destroy(&mgr->lock);
5598 0 : mutex_destroy(&mgr->up_req_lock);
5599 0 : mutex_destroy(&mgr->probe_lock);
5600 : #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5601 : mutex_destroy(&mgr->topology_ref_history_lock);
5602 : #endif
5603 0 : }
5604 : EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
5605 :
5606 0 : static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
5607 : {
5608 : int i;
5609 :
5610 0 : if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
5611 : return false;
5612 :
5613 0 : for (i = 0; i < num - 1; i++) {
5614 0 : if (msgs[i].flags & I2C_M_RD ||
5615 0 : msgs[i].len > 0xff)
5616 : return false;
5617 : }
5618 :
5619 0 : return msgs[num - 1].flags & I2C_M_RD &&
5620 0 : msgs[num - 1].len <= 0xff;
5621 : }
5622 :
5623 0 : static bool remote_i2c_write_ok(const struct i2c_msg msgs[], int num)
5624 : {
5625 : int i;
5626 :
5627 0 : for (i = 0; i < num - 1; i++) {
5628 0 : if (msgs[i].flags & I2C_M_RD || !(msgs[i].flags & I2C_M_STOP) ||
5629 0 : msgs[i].len > 0xff)
5630 : return false;
5631 : }
5632 :
5633 0 : return !(msgs[num - 1].flags & I2C_M_RD) && msgs[num - 1].len <= 0xff;
5634 : }
5635 :
5636 0 : static int drm_dp_mst_i2c_read(struct drm_dp_mst_branch *mstb,
5637 : struct drm_dp_mst_port *port,
5638 : struct i2c_msg *msgs, int num)
5639 : {
5640 0 : struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5641 : unsigned int i;
5642 : struct drm_dp_sideband_msg_req_body msg;
5643 0 : struct drm_dp_sideband_msg_tx *txmsg = NULL;
5644 : int ret;
5645 :
5646 0 : memset(&msg, 0, sizeof(msg));
5647 0 : msg.req_type = DP_REMOTE_I2C_READ;
5648 0 : msg.u.i2c_read.num_transactions = num - 1;
5649 0 : msg.u.i2c_read.port_number = port->port_num;
5650 0 : for (i = 0; i < num - 1; i++) {
5651 0 : msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
5652 0 : msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
5653 0 : msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
5654 0 : msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
5655 : }
5656 0 : msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
5657 0 : msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
5658 :
5659 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5660 0 : if (!txmsg) {
5661 : ret = -ENOMEM;
5662 : goto out;
5663 : }
5664 :
5665 0 : txmsg->dst = mstb;
5666 0 : drm_dp_encode_sideband_req(&msg, txmsg);
5667 :
5668 0 : drm_dp_queue_down_tx(mgr, txmsg);
5669 :
5670 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5671 0 : if (ret > 0) {
5672 :
5673 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5674 : ret = -EREMOTEIO;
5675 : goto out;
5676 : }
5677 0 : if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
5678 : ret = -EIO;
5679 : goto out;
5680 : }
5681 0 : memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
5682 0 : ret = num;
5683 : }
5684 : out:
5685 0 : kfree(txmsg);
5686 0 : return ret;
5687 : }
5688 :
5689 0 : static int drm_dp_mst_i2c_write(struct drm_dp_mst_branch *mstb,
5690 : struct drm_dp_mst_port *port,
5691 : struct i2c_msg *msgs, int num)
5692 : {
5693 0 : struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5694 : unsigned int i;
5695 : struct drm_dp_sideband_msg_req_body msg;
5696 0 : struct drm_dp_sideband_msg_tx *txmsg = NULL;
5697 : int ret;
5698 :
5699 0 : txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5700 0 : if (!txmsg) {
5701 : ret = -ENOMEM;
5702 : goto out;
5703 : }
5704 0 : for (i = 0; i < num; i++) {
5705 0 : memset(&msg, 0, sizeof(msg));
5706 0 : msg.req_type = DP_REMOTE_I2C_WRITE;
5707 0 : msg.u.i2c_write.port_number = port->port_num;
5708 0 : msg.u.i2c_write.write_i2c_device_id = msgs[i].addr;
5709 0 : msg.u.i2c_write.num_bytes = msgs[i].len;
5710 0 : msg.u.i2c_write.bytes = msgs[i].buf;
5711 :
5712 0 : memset(txmsg, 0, sizeof(*txmsg));
5713 0 : txmsg->dst = mstb;
5714 :
5715 0 : drm_dp_encode_sideband_req(&msg, txmsg);
5716 0 : drm_dp_queue_down_tx(mgr, txmsg);
5717 :
5718 0 : ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5719 0 : if (ret > 0) {
5720 0 : if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5721 : ret = -EREMOTEIO;
5722 : goto out;
5723 : }
5724 : } else {
5725 : goto out;
5726 : }
5727 : }
5728 : ret = num;
5729 : out:
5730 0 : kfree(txmsg);
5731 0 : return ret;
5732 : }
5733 :
5734 : /* I2C device */
5735 0 : static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter,
5736 : struct i2c_msg *msgs, int num)
5737 : {
5738 0 : struct drm_dp_aux *aux = adapter->algo_data;
5739 0 : struct drm_dp_mst_port *port =
5740 0 : container_of(aux, struct drm_dp_mst_port, aux);
5741 : struct drm_dp_mst_branch *mstb;
5742 0 : struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5743 : int ret;
5744 :
5745 0 : mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
5746 0 : if (!mstb)
5747 : return -EREMOTEIO;
5748 :
5749 0 : if (remote_i2c_read_ok(msgs, num)) {
5750 0 : ret = drm_dp_mst_i2c_read(mstb, port, msgs, num);
5751 0 : } else if (remote_i2c_write_ok(msgs, num)) {
5752 0 : ret = drm_dp_mst_i2c_write(mstb, port, msgs, num);
5753 : } else {
5754 0 : drm_dbg_kms(mgr->dev, "Unsupported I2C transaction for MST device\n");
5755 0 : ret = -EIO;
5756 : }
5757 :
5758 0 : drm_dp_mst_topology_put_mstb(mstb);
5759 0 : return ret;
5760 : }
5761 :
5762 0 : static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
5763 : {
5764 0 : return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
5765 : I2C_FUNC_SMBUS_READ_BLOCK_DATA |
5766 : I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
5767 : I2C_FUNC_10BIT_ADDR;
5768 : }
5769 :
5770 : static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
5771 : .functionality = drm_dp_mst_i2c_functionality,
5772 : .master_xfer = drm_dp_mst_i2c_xfer,
5773 : };
5774 :
5775 : /**
5776 : * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
5777 : * @port: The port to add the I2C bus on
5778 : *
5779 : * Returns 0 on success or a negative error code on failure.
5780 : */
5781 0 : static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port)
5782 : {
5783 0 : struct drm_dp_aux *aux = &port->aux;
5784 0 : struct device *parent_dev = port->mgr->dev->dev;
5785 :
5786 0 : aux->ddc.algo = &drm_dp_mst_i2c_algo;
5787 0 : aux->ddc.algo_data = aux;
5788 0 : aux->ddc.retries = 3;
5789 :
5790 0 : aux->ddc.class = I2C_CLASS_DDC;
5791 0 : aux->ddc.owner = THIS_MODULE;
5792 : /* FIXME: set the kdev of the port's connector as parent */
5793 0 : aux->ddc.dev.parent = parent_dev;
5794 0 : aux->ddc.dev.of_node = parent_dev->of_node;
5795 :
5796 0 : strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev),
5797 : sizeof(aux->ddc.name));
5798 :
5799 0 : return i2c_add_adapter(&aux->ddc);
5800 : }
5801 :
5802 : /**
5803 : * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
5804 : * @port: The port to remove the I2C bus from
5805 : */
5806 : static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port)
5807 : {
5808 0 : i2c_del_adapter(&port->aux.ddc);
5809 : }
5810 :
5811 : /**
5812 : * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device
5813 : * @port: The port to check
5814 : *
5815 : * A single physical MST hub object can be represented in the topology
5816 : * by multiple branches, with virtual ports between those branches.
5817 : *
5818 : * As of DP1.4, An MST hub with internal (virtual) ports must expose
5819 : * certain DPCD registers over those ports. See sections 2.6.1.1.1
5820 : * and 2.6.1.1.2 of Display Port specification v1.4 for details.
5821 : *
5822 : * May acquire mgr->lock
5823 : *
5824 : * Returns:
5825 : * true if the port is a virtual DP peer device, false otherwise
5826 : */
5827 0 : static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port)
5828 : {
5829 : struct drm_dp_mst_port *downstream_port;
5830 :
5831 0 : if (!port || port->dpcd_rev < DP_DPCD_REV_14)
5832 : return false;
5833 :
5834 : /* Virtual DP Sink (Internal Display Panel) */
5835 0 : if (port->port_num >= 8)
5836 : return true;
5837 :
5838 : /* DP-to-HDMI Protocol Converter */
5839 0 : if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV &&
5840 0 : !port->mcs &&
5841 0 : port->ldps)
5842 : return true;
5843 :
5844 : /* DP-to-DP */
5845 0 : mutex_lock(&port->mgr->lock);
5846 0 : if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
5847 0 : port->mstb &&
5848 0 : port->mstb->num_ports == 2) {
5849 0 : list_for_each_entry(downstream_port, &port->mstb->ports, next) {
5850 0 : if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK &&
5851 0 : !downstream_port->input) {
5852 0 : mutex_unlock(&port->mgr->lock);
5853 0 : return true;
5854 : }
5855 : }
5856 : }
5857 0 : mutex_unlock(&port->mgr->lock);
5858 :
5859 0 : return false;
5860 : }
5861 :
5862 : /**
5863 : * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
5864 : * @port: The port to check. A leaf of the MST tree with an attached display.
5865 : *
5866 : * Depending on the situation, DSC may be enabled via the endpoint aux,
5867 : * the immediately upstream aux, or the connector's physical aux.
5868 : *
5869 : * This is both the correct aux to read DSC_CAPABILITY and the
5870 : * correct aux to write DSC_ENABLED.
5871 : *
5872 : * This operation can be expensive (up to four aux reads), so
5873 : * the caller should cache the return.
5874 : *
5875 : * Returns:
5876 : * NULL if DSC cannot be enabled on this port, otherwise the aux device
5877 : */
5878 0 : struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
5879 : {
5880 : struct drm_dp_mst_port *immediate_upstream_port;
5881 : struct drm_dp_mst_port *fec_port;
5882 0 : struct drm_dp_desc desc = {};
5883 : u8 endpoint_fec;
5884 : u8 endpoint_dsc;
5885 :
5886 0 : if (!port)
5887 : return NULL;
5888 :
5889 0 : if (port->parent->port_parent)
5890 0 : immediate_upstream_port = port->parent->port_parent;
5891 : else
5892 : immediate_upstream_port = NULL;
5893 :
5894 0 : fec_port = immediate_upstream_port;
5895 0 : while (fec_port) {
5896 : /*
5897 : * Each physical link (i.e. not a virtual port) between the
5898 : * output and the primary device must support FEC
5899 : */
5900 0 : if (!drm_dp_mst_is_virtual_dpcd(fec_port) &&
5901 0 : !fec_port->fec_capable)
5902 : return NULL;
5903 :
5904 0 : fec_port = fec_port->parent->port_parent;
5905 : }
5906 :
5907 : /* DP-to-DP peer device */
5908 0 : if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) {
5909 : u8 upstream_dsc;
5910 :
5911 0 : if (drm_dp_dpcd_read(&port->aux,
5912 : DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5913 : return NULL;
5914 0 : if (drm_dp_dpcd_read(&port->aux,
5915 : DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5916 : return NULL;
5917 0 : if (drm_dp_dpcd_read(&immediate_upstream_port->aux,
5918 : DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
5919 : return NULL;
5920 :
5921 : /* Enpoint decompression with DP-to-DP peer device */
5922 0 : if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5923 0 : (endpoint_fec & DP_FEC_CAPABLE) &&
5924 0 : (upstream_dsc & DP_DSC_PASSTHROUGH_IS_SUPPORTED)) {
5925 0 : port->passthrough_aux = &immediate_upstream_port->aux;
5926 0 : return &port->aux;
5927 : }
5928 :
5929 : /* Virtual DPCD decompression with DP-to-DP peer device */
5930 : return &immediate_upstream_port->aux;
5931 : }
5932 :
5933 : /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */
5934 0 : if (drm_dp_mst_is_virtual_dpcd(port))
5935 0 : return &port->aux;
5936 :
5937 : /*
5938 : * Synaptics quirk
5939 : * Applies to ports for which:
5940 : * - Physical aux has Synaptics OUI
5941 : * - DPv1.4 or higher
5942 : * - Port is on primary branch device
5943 : * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG)
5944 : */
5945 0 : if (drm_dp_read_desc(port->mgr->aux, &desc, true))
5946 : return NULL;
5947 :
5948 0 : if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) &&
5949 0 : port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 &&
5950 0 : port->parent == port->mgr->mst_primary) {
5951 : u8 dpcd_ext[DP_RECEIVER_CAP_SIZE];
5952 :
5953 0 : if (drm_dp_read_dpcd_caps(port->mgr->aux, dpcd_ext) < 0)
5954 0 : return NULL;
5955 :
5956 0 : if ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT) &&
5957 : ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK)
5958 : != DP_DWN_STRM_PORT_TYPE_ANALOG))
5959 0 : return port->mgr->aux;
5960 : }
5961 :
5962 : /*
5963 : * The check below verifies if the MST sink
5964 : * connected to the GPU is capable of DSC -
5965 : * therefore the endpoint needs to be
5966 : * both DSC and FEC capable.
5967 : */
5968 0 : if (drm_dp_dpcd_read(&port->aux,
5969 : DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5970 : return NULL;
5971 0 : if (drm_dp_dpcd_read(&port->aux,
5972 : DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5973 : return NULL;
5974 0 : if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5975 0 : (endpoint_fec & DP_FEC_CAPABLE))
5976 0 : return &port->aux;
5977 :
5978 : return NULL;
5979 : }
5980 : EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);
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