2 * Copyright © 2014 Red Hat
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.
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
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>
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>
41 #include <drm/display/drm_dp_mst_helper.h>
42 #include <drm/drm_atomic.h>
43 #include <drm/drm_atomic_helper.h>
44 #include <drm/drm_drv.h>
45 #include <drm/drm_edid.h>
46 #include <drm/drm_print.h>
47 #include <drm/drm_probe_helper.h>
49 #include "drm_dp_helper_internal.h"
50 #include "drm_dp_mst_topology_internal.h"
55 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
56 * protocol. The helpers contain a topology manager and bandwidth manager.
57 * The helpers encapsulate the sending and received of sideband msgs.
59 struct drm_dp_pending_up_req {
60 struct drm_dp_sideband_msg_hdr hdr;
61 struct drm_dp_sideband_msg_req_body msg;
62 struct list_head next;
65 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
68 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
70 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
72 struct drm_dp_payload *payload);
74 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
75 struct drm_dp_mst_port *port,
76 int offset, int size, u8 *bytes);
77 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
78 struct drm_dp_mst_port *port,
79 int offset, int size, u8 *bytes);
81 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
82 struct drm_dp_mst_branch *mstb);
85 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
86 struct drm_dp_mst_branch *mstb);
88 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
89 struct drm_dp_mst_branch *mstb,
90 struct drm_dp_mst_port *port);
91 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
94 static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port);
95 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port);
96 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
98 static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
99 struct drm_dp_mst_branch *branch);
101 #define DBG_PREFIX "[dp_mst]"
103 #define DP_STR(x) [DP_ ## x] = #x
105 static const char *drm_dp_mst_req_type_str(u8 req_type)
107 static const char * const req_type_str[] = {
108 DP_STR(GET_MSG_TRANSACTION_VERSION),
109 DP_STR(LINK_ADDRESS),
110 DP_STR(CONNECTION_STATUS_NOTIFY),
111 DP_STR(ENUM_PATH_RESOURCES),
112 DP_STR(ALLOCATE_PAYLOAD),
113 DP_STR(QUERY_PAYLOAD),
114 DP_STR(RESOURCE_STATUS_NOTIFY),
115 DP_STR(CLEAR_PAYLOAD_ID_TABLE),
116 DP_STR(REMOTE_DPCD_READ),
117 DP_STR(REMOTE_DPCD_WRITE),
118 DP_STR(REMOTE_I2C_READ),
119 DP_STR(REMOTE_I2C_WRITE),
120 DP_STR(POWER_UP_PHY),
121 DP_STR(POWER_DOWN_PHY),
122 DP_STR(SINK_EVENT_NOTIFY),
123 DP_STR(QUERY_STREAM_ENC_STATUS),
126 if (req_type >= ARRAY_SIZE(req_type_str) ||
127 !req_type_str[req_type])
130 return req_type_str[req_type];
134 #define DP_STR(x) [DP_NAK_ ## x] = #x
136 static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
138 static const char * const nak_reason_str[] = {
139 DP_STR(WRITE_FAILURE),
140 DP_STR(INVALID_READ),
144 DP_STR(LINK_FAILURE),
145 DP_STR(NO_RESOURCES),
148 DP_STR(ALLOCATE_FAIL),
151 if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
152 !nak_reason_str[nak_reason])
155 return nak_reason_str[nak_reason];
159 #define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x
161 static const char *drm_dp_mst_sideband_tx_state_str(int state)
163 static const char * const sideband_reason_str[] = {
171 if (state >= ARRAY_SIZE(sideband_reason_str) ||
172 !sideband_reason_str[state])
175 return sideband_reason_str[state];
179 drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len)
184 for (i = 0; i < lct; i++) {
186 unpacked_rad[i] = rad[i / 2] >> 4;
188 unpacked_rad[i] = rad[i / 2] & BIT_MASK(4);
191 /* TODO: Eventually add something to printk so we can format the rad
194 return snprintf(out, len, "%*phC", lct, unpacked_rad);
197 /* sideband msg handling */
198 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
203 int number_of_bits = num_nibbles * 4;
206 while (number_of_bits != 0) {
209 remainder |= (data[array_index] & bitmask) >> bitshift;
217 if ((remainder & 0x10) == 0x10)
222 while (number_of_bits != 0) {
225 if ((remainder & 0x10) != 0)
232 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
237 int number_of_bits = number_of_bytes * 8;
240 while (number_of_bits != 0) {
243 remainder |= (data[array_index] & bitmask) >> bitshift;
251 if ((remainder & 0x100) == 0x100)
256 while (number_of_bits != 0) {
259 if ((remainder & 0x100) != 0)
263 return remainder & 0xff;
265 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
269 size += (hdr->lct / 2);
273 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
280 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
281 for (i = 0; i < (hdr->lct / 2); i++)
282 buf[idx++] = hdr->rad[i];
283 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
284 (hdr->msg_len & 0x3f);
285 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
287 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
288 buf[idx - 1] |= (crc4 & 0xf);
293 static bool drm_dp_decode_sideband_msg_hdr(const struct drm_dp_mst_topology_mgr *mgr,
294 struct drm_dp_sideband_msg_hdr *hdr,
295 u8 *buf, int buflen, u8 *hdrlen)
305 len += ((buf[0] & 0xf0) >> 4) / 2;
308 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
310 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
311 drm_dbg_kms(mgr->dev, "crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
315 hdr->lct = (buf[0] & 0xf0) >> 4;
316 hdr->lcr = (buf[0] & 0xf);
318 for (i = 0; i < (hdr->lct / 2); i++)
319 hdr->rad[i] = buf[idx++];
320 hdr->broadcast = (buf[idx] >> 7) & 0x1;
321 hdr->path_msg = (buf[idx] >> 6) & 0x1;
322 hdr->msg_len = buf[idx] & 0x3f;
324 hdr->somt = (buf[idx] >> 7) & 0x1;
325 hdr->eomt = (buf[idx] >> 6) & 0x1;
326 hdr->seqno = (buf[idx] >> 4) & 0x1;
333 drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
334 struct drm_dp_sideband_msg_tx *raw)
340 buf[idx++] = req->req_type & 0x7f;
342 switch (req->req_type) {
343 case DP_ENUM_PATH_RESOURCES:
344 case DP_POWER_DOWN_PHY:
345 case DP_POWER_UP_PHY:
346 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
349 case DP_ALLOCATE_PAYLOAD:
350 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
351 (req->u.allocate_payload.number_sdp_streams & 0xf);
353 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
355 buf[idx] = (req->u.allocate_payload.pbn >> 8);
357 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
359 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
360 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
361 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
364 if (req->u.allocate_payload.number_sdp_streams & 1) {
365 i = req->u.allocate_payload.number_sdp_streams - 1;
366 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
370 case DP_QUERY_PAYLOAD:
371 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
373 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
376 case DP_REMOTE_DPCD_READ:
377 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
378 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
380 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
382 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
384 buf[idx] = (req->u.dpcd_read.num_bytes);
388 case DP_REMOTE_DPCD_WRITE:
389 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
390 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
392 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
394 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
396 buf[idx] = (req->u.dpcd_write.num_bytes);
398 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
399 idx += req->u.dpcd_write.num_bytes;
401 case DP_REMOTE_I2C_READ:
402 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
403 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
405 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
406 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
408 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
410 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
411 idx += req->u.i2c_read.transactions[i].num_bytes;
413 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
414 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
417 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
419 buf[idx] = (req->u.i2c_read.num_bytes_read);
423 case DP_REMOTE_I2C_WRITE:
424 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
426 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
428 buf[idx] = (req->u.i2c_write.num_bytes);
430 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
431 idx += req->u.i2c_write.num_bytes;
433 case DP_QUERY_STREAM_ENC_STATUS: {
434 const struct drm_dp_query_stream_enc_status *msg;
436 msg = &req->u.enc_status;
437 buf[idx] = msg->stream_id;
439 memcpy(&buf[idx], msg->client_id, sizeof(msg->client_id));
440 idx += sizeof(msg->client_id);
442 buf[idx] |= FIELD_PREP(GENMASK(1, 0), msg->stream_event);
443 buf[idx] |= msg->valid_stream_event ? BIT(2) : 0;
444 buf[idx] |= FIELD_PREP(GENMASK(4, 3), msg->stream_behavior);
445 buf[idx] |= msg->valid_stream_behavior ? BIT(5) : 0;
452 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req);
454 /* Decode a sideband request we've encoded, mainly used for debugging */
456 drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
457 struct drm_dp_sideband_msg_req_body *req)
459 const u8 *buf = raw->msg;
462 req->req_type = buf[idx++] & 0x7f;
463 switch (req->req_type) {
464 case DP_ENUM_PATH_RESOURCES:
465 case DP_POWER_DOWN_PHY:
466 case DP_POWER_UP_PHY:
467 req->u.port_num.port_number = (buf[idx] >> 4) & 0xf;
469 case DP_ALLOCATE_PAYLOAD:
471 struct drm_dp_allocate_payload *a =
472 &req->u.allocate_payload;
474 a->number_sdp_streams = buf[idx] & 0xf;
475 a->port_number = (buf[idx] >> 4) & 0xf;
477 WARN_ON(buf[++idx] & 0x80);
478 a->vcpi = buf[idx] & 0x7f;
480 a->pbn = buf[++idx] << 8;
481 a->pbn |= buf[++idx];
484 for (i = 0; i < a->number_sdp_streams; i++) {
485 a->sdp_stream_sink[i] =
486 (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf;
490 case DP_QUERY_PAYLOAD:
491 req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf;
492 WARN_ON(buf[++idx] & 0x80);
493 req->u.query_payload.vcpi = buf[idx] & 0x7f;
495 case DP_REMOTE_DPCD_READ:
497 struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read;
499 r->port_number = (buf[idx] >> 4) & 0xf;
501 r->dpcd_address = (buf[idx] << 16) & 0xf0000;
502 r->dpcd_address |= (buf[++idx] << 8) & 0xff00;
503 r->dpcd_address |= buf[++idx] & 0xff;
505 r->num_bytes = buf[++idx];
508 case DP_REMOTE_DPCD_WRITE:
510 struct drm_dp_remote_dpcd_write *w =
513 w->port_number = (buf[idx] >> 4) & 0xf;
515 w->dpcd_address = (buf[idx] << 16) & 0xf0000;
516 w->dpcd_address |= (buf[++idx] << 8) & 0xff00;
517 w->dpcd_address |= buf[++idx] & 0xff;
519 w->num_bytes = buf[++idx];
521 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
527 case DP_REMOTE_I2C_READ:
529 struct drm_dp_remote_i2c_read *r = &req->u.i2c_read;
530 struct drm_dp_remote_i2c_read_tx *tx;
533 r->num_transactions = buf[idx] & 0x3;
534 r->port_number = (buf[idx] >> 4) & 0xf;
535 for (i = 0; i < r->num_transactions; i++) {
536 tx = &r->transactions[i];
538 tx->i2c_dev_id = buf[++idx] & 0x7f;
539 tx->num_bytes = buf[++idx];
540 tx->bytes = kmemdup(&buf[++idx],
547 idx += tx->num_bytes;
548 tx->no_stop_bit = (buf[idx] >> 5) & 0x1;
549 tx->i2c_transaction_delay = buf[idx] & 0xf;
553 for (i = 0; i < r->num_transactions; i++) {
554 tx = &r->transactions[i];
560 r->read_i2c_device_id = buf[++idx] & 0x7f;
561 r->num_bytes_read = buf[++idx];
564 case DP_REMOTE_I2C_WRITE:
566 struct drm_dp_remote_i2c_write *w = &req->u.i2c_write;
568 w->port_number = (buf[idx] >> 4) & 0xf;
569 w->write_i2c_device_id = buf[++idx] & 0x7f;
570 w->num_bytes = buf[++idx];
571 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
577 case DP_QUERY_STREAM_ENC_STATUS:
578 req->u.enc_status.stream_id = buf[idx++];
579 for (i = 0; i < sizeof(req->u.enc_status.client_id); i++)
580 req->u.enc_status.client_id[i] = buf[idx++];
582 req->u.enc_status.stream_event = FIELD_GET(GENMASK(1, 0),
584 req->u.enc_status.valid_stream_event = FIELD_GET(BIT(2),
586 req->u.enc_status.stream_behavior = FIELD_GET(GENMASK(4, 3),
588 req->u.enc_status.valid_stream_behavior = FIELD_GET(BIT(5),
595 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req);
598 drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req,
599 int indent, struct drm_printer *printer)
603 #define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__)
604 if (req->req_type == DP_LINK_ADDRESS) {
605 /* No contents to print */
606 P("type=%s\n", drm_dp_mst_req_type_str(req->req_type));
610 P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type));
613 switch (req->req_type) {
614 case DP_ENUM_PATH_RESOURCES:
615 case DP_POWER_DOWN_PHY:
616 case DP_POWER_UP_PHY:
617 P("port=%d\n", req->u.port_num.port_number);
619 case DP_ALLOCATE_PAYLOAD:
620 P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n",
621 req->u.allocate_payload.port_number,
622 req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn,
623 req->u.allocate_payload.number_sdp_streams,
624 req->u.allocate_payload.number_sdp_streams,
625 req->u.allocate_payload.sdp_stream_sink);
627 case DP_QUERY_PAYLOAD:
628 P("port=%d vcpi=%d\n",
629 req->u.query_payload.port_number,
630 req->u.query_payload.vcpi);
632 case DP_REMOTE_DPCD_READ:
633 P("port=%d dpcd_addr=%05x len=%d\n",
634 req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address,
635 req->u.dpcd_read.num_bytes);
637 case DP_REMOTE_DPCD_WRITE:
638 P("port=%d addr=%05x len=%d: %*ph\n",
639 req->u.dpcd_write.port_number,
640 req->u.dpcd_write.dpcd_address,
641 req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes,
642 req->u.dpcd_write.bytes);
644 case DP_REMOTE_I2C_READ:
645 P("port=%d num_tx=%d id=%d size=%d:\n",
646 req->u.i2c_read.port_number,
647 req->u.i2c_read.num_transactions,
648 req->u.i2c_read.read_i2c_device_id,
649 req->u.i2c_read.num_bytes_read);
652 for (i = 0; i < req->u.i2c_read.num_transactions; i++) {
653 const struct drm_dp_remote_i2c_read_tx *rtx =
654 &req->u.i2c_read.transactions[i];
656 P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n",
657 i, rtx->i2c_dev_id, rtx->num_bytes,
658 rtx->no_stop_bit, rtx->i2c_transaction_delay,
659 rtx->num_bytes, rtx->bytes);
662 case DP_REMOTE_I2C_WRITE:
663 P("port=%d id=%d size=%d: %*ph\n",
664 req->u.i2c_write.port_number,
665 req->u.i2c_write.write_i2c_device_id,
666 req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes,
667 req->u.i2c_write.bytes);
669 case DP_QUERY_STREAM_ENC_STATUS:
670 P("stream_id=%u client_id=%*ph stream_event=%x "
671 "valid_event=%d stream_behavior=%x valid_behavior=%d",
672 req->u.enc_status.stream_id,
673 (int)ARRAY_SIZE(req->u.enc_status.client_id),
674 req->u.enc_status.client_id, req->u.enc_status.stream_event,
675 req->u.enc_status.valid_stream_event,
676 req->u.enc_status.stream_behavior,
677 req->u.enc_status.valid_stream_behavior);
685 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body);
688 drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p,
689 const struct drm_dp_sideband_msg_tx *txmsg)
691 struct drm_dp_sideband_msg_req_body req;
696 drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf,
698 drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n",
699 txmsg->cur_offset, txmsg->cur_len, txmsg->seqno,
700 drm_dp_mst_sideband_tx_state_str(txmsg->state),
701 txmsg->path_msg, buf);
703 ret = drm_dp_decode_sideband_req(txmsg, &req);
705 drm_printf(p, "<failed to decode sideband req: %d>\n", ret);
708 drm_dp_dump_sideband_msg_req_body(&req, 1, p);
710 switch (req.req_type) {
711 case DP_REMOTE_DPCD_WRITE:
712 kfree(req.u.dpcd_write.bytes);
714 case DP_REMOTE_I2C_READ:
715 for (i = 0; i < req.u.i2c_read.num_transactions; i++)
716 kfree(req.u.i2c_read.transactions[i].bytes);
718 case DP_REMOTE_I2C_WRITE:
719 kfree(req.u.i2c_write.bytes);
724 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
728 crc4 = drm_dp_msg_data_crc4(msg, len);
732 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
733 struct drm_dp_sideband_msg_tx *raw)
738 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
743 static int drm_dp_sideband_msg_set_header(struct drm_dp_sideband_msg_rx *msg,
744 struct drm_dp_sideband_msg_hdr *hdr,
748 * ignore out-of-order messages or messages that are part of a
751 if (!hdr->somt && !msg->have_somt)
754 /* get length contained in this portion */
755 msg->curchunk_idx = 0;
756 msg->curchunk_len = hdr->msg_len;
757 msg->curchunk_hdrlen = hdrlen;
759 /* we have already gotten an somt - don't bother parsing */
760 if (hdr->somt && msg->have_somt)
764 memcpy(&msg->initial_hdr, hdr,
765 sizeof(struct drm_dp_sideband_msg_hdr));
766 msg->have_somt = true;
769 msg->have_eomt = true;
774 /* this adds a chunk of msg to the builder to get the final msg */
775 static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx *msg,
776 u8 *replybuf, u8 replybuflen)
780 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
781 msg->curchunk_idx += replybuflen;
783 if (msg->curchunk_idx >= msg->curchunk_len) {
785 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
786 if (crc4 != msg->chunk[msg->curchunk_len - 1])
787 print_hex_dump(KERN_DEBUG, "wrong crc",
788 DUMP_PREFIX_NONE, 16, 1,
789 msg->chunk, msg->curchunk_len, false);
790 /* copy chunk into bigger msg */
791 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
792 msg->curlen += msg->curchunk_len - 1;
797 static bool drm_dp_sideband_parse_link_address(const struct drm_dp_mst_topology_mgr *mgr,
798 struct drm_dp_sideband_msg_rx *raw,
799 struct drm_dp_sideband_msg_reply_body *repmsg)
804 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
806 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
808 if (idx > raw->curlen)
810 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
811 if (raw->msg[idx] & 0x80)
812 repmsg->u.link_addr.ports[i].input_port = 1;
814 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
815 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
818 if (idx > raw->curlen)
820 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
821 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
822 if (repmsg->u.link_addr.ports[i].input_port == 0)
823 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
825 if (idx > raw->curlen)
827 if (repmsg->u.link_addr.ports[i].input_port == 0) {
828 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
830 if (idx > raw->curlen)
832 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
834 if (idx > raw->curlen)
836 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
837 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
841 if (idx > raw->curlen)
847 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
851 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
852 struct drm_dp_sideband_msg_reply_body *repmsg)
856 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
858 if (idx > raw->curlen)
860 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
862 if (idx > raw->curlen)
865 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
868 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
872 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
873 struct drm_dp_sideband_msg_reply_body *repmsg)
877 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
879 if (idx > raw->curlen)
883 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
887 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
888 struct drm_dp_sideband_msg_reply_body *repmsg)
892 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
894 if (idx > raw->curlen)
896 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
899 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
902 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
906 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
907 struct drm_dp_sideband_msg_reply_body *repmsg)
911 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
912 repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1;
914 if (idx > raw->curlen)
916 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
918 if (idx > raw->curlen)
920 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
922 if (idx > raw->curlen)
926 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
930 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
931 struct drm_dp_sideband_msg_reply_body *repmsg)
935 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
937 if (idx > raw->curlen)
939 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
941 if (idx > raw->curlen)
943 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
945 if (idx > raw->curlen)
949 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
953 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
954 struct drm_dp_sideband_msg_reply_body *repmsg)
958 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
960 if (idx > raw->curlen)
962 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
964 if (idx > raw->curlen)
968 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
972 static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
973 struct drm_dp_sideband_msg_reply_body *repmsg)
977 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
979 if (idx > raw->curlen) {
980 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
988 drm_dp_sideband_parse_query_stream_enc_status(
989 struct drm_dp_sideband_msg_rx *raw,
990 struct drm_dp_sideband_msg_reply_body *repmsg)
992 struct drm_dp_query_stream_enc_status_ack_reply *reply;
994 reply = &repmsg->u.enc_status;
996 reply->stream_id = raw->msg[3];
998 reply->reply_signed = raw->msg[2] & BIT(0);
1001 * NOTE: It's my impression from reading the spec that the below parsing
1002 * is correct. However I noticed while testing with an HDCP 1.4 display
1003 * through an HDCP 2.2 hub that only bit 3 was set. In that case, I
1004 * would expect both bits to be set. So keep the parsing following the
1005 * spec, but beware reality might not match the spec (at least for some
1008 reply->hdcp_1x_device_present = raw->msg[2] & BIT(4);
1009 reply->hdcp_2x_device_present = raw->msg[2] & BIT(3);
1011 reply->query_capable_device_present = raw->msg[2] & BIT(5);
1012 reply->legacy_device_present = raw->msg[2] & BIT(6);
1013 reply->unauthorizable_device_present = raw->msg[2] & BIT(7);
1015 reply->auth_completed = !!(raw->msg[1] & BIT(3));
1016 reply->encryption_enabled = !!(raw->msg[1] & BIT(4));
1017 reply->repeater_present = !!(raw->msg[1] & BIT(5));
1018 reply->state = (raw->msg[1] & GENMASK(7, 6)) >> 6;
1023 static bool drm_dp_sideband_parse_reply(const struct drm_dp_mst_topology_mgr *mgr,
1024 struct drm_dp_sideband_msg_rx *raw,
1025 struct drm_dp_sideband_msg_reply_body *msg)
1027 memset(msg, 0, sizeof(*msg));
1028 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
1029 msg->req_type = (raw->msg[0] & 0x7f);
1031 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
1032 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
1033 msg->u.nak.reason = raw->msg[17];
1034 msg->u.nak.nak_data = raw->msg[18];
1038 switch (msg->req_type) {
1039 case DP_LINK_ADDRESS:
1040 return drm_dp_sideband_parse_link_address(mgr, raw, msg);
1041 case DP_QUERY_PAYLOAD:
1042 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
1043 case DP_REMOTE_DPCD_READ:
1044 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
1045 case DP_REMOTE_DPCD_WRITE:
1046 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
1047 case DP_REMOTE_I2C_READ:
1048 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
1049 case DP_REMOTE_I2C_WRITE:
1050 return true; /* since there's nothing to parse */
1051 case DP_ENUM_PATH_RESOURCES:
1052 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
1053 case DP_ALLOCATE_PAYLOAD:
1054 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
1055 case DP_POWER_DOWN_PHY:
1056 case DP_POWER_UP_PHY:
1057 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
1058 case DP_CLEAR_PAYLOAD_ID_TABLE:
1059 return true; /* since there's nothing to parse */
1060 case DP_QUERY_STREAM_ENC_STATUS:
1061 return drm_dp_sideband_parse_query_stream_enc_status(raw, msg);
1063 drm_err(mgr->dev, "Got unknown reply 0x%02x (%s)\n",
1064 msg->req_type, drm_dp_mst_req_type_str(msg->req_type));
1070 drm_dp_sideband_parse_connection_status_notify(const struct drm_dp_mst_topology_mgr *mgr,
1071 struct drm_dp_sideband_msg_rx *raw,
1072 struct drm_dp_sideband_msg_req_body *msg)
1076 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
1078 if (idx > raw->curlen)
1081 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
1083 if (idx > raw->curlen)
1086 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
1087 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
1088 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
1089 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
1090 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
1094 drm_dbg_kms(mgr->dev, "connection status reply parse length fail %d %d\n",
1099 static bool drm_dp_sideband_parse_resource_status_notify(const struct drm_dp_mst_topology_mgr *mgr,
1100 struct drm_dp_sideband_msg_rx *raw,
1101 struct drm_dp_sideband_msg_req_body *msg)
1105 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
1107 if (idx > raw->curlen)
1110 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
1112 if (idx > raw->curlen)
1115 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
1119 drm_dbg_kms(mgr->dev, "resource status reply parse length fail %d %d\n", idx, raw->curlen);
1123 static bool drm_dp_sideband_parse_req(const struct drm_dp_mst_topology_mgr *mgr,
1124 struct drm_dp_sideband_msg_rx *raw,
1125 struct drm_dp_sideband_msg_req_body *msg)
1127 memset(msg, 0, sizeof(*msg));
1128 msg->req_type = (raw->msg[0] & 0x7f);
1130 switch (msg->req_type) {
1131 case DP_CONNECTION_STATUS_NOTIFY:
1132 return drm_dp_sideband_parse_connection_status_notify(mgr, raw, msg);
1133 case DP_RESOURCE_STATUS_NOTIFY:
1134 return drm_dp_sideband_parse_resource_status_notify(mgr, raw, msg);
1136 drm_err(mgr->dev, "Got unknown request 0x%02x (%s)\n",
1137 msg->req_type, drm_dp_mst_req_type_str(msg->req_type));
1142 static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg,
1143 u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
1145 struct drm_dp_sideband_msg_req_body req;
1147 req.req_type = DP_REMOTE_DPCD_WRITE;
1148 req.u.dpcd_write.port_number = port_num;
1149 req.u.dpcd_write.dpcd_address = offset;
1150 req.u.dpcd_write.num_bytes = num_bytes;
1151 req.u.dpcd_write.bytes = bytes;
1152 drm_dp_encode_sideband_req(&req, msg);
1155 static void build_link_address(struct drm_dp_sideband_msg_tx *msg)
1157 struct drm_dp_sideband_msg_req_body req;
1159 req.req_type = DP_LINK_ADDRESS;
1160 drm_dp_encode_sideband_req(&req, msg);
1163 static void build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
1165 struct drm_dp_sideband_msg_req_body req;
1167 req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE;
1168 drm_dp_encode_sideband_req(&req, msg);
1169 msg->path_msg = true;
1172 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg,
1175 struct drm_dp_sideband_msg_req_body req;
1177 req.req_type = DP_ENUM_PATH_RESOURCES;
1178 req.u.port_num.port_number = port_num;
1179 drm_dp_encode_sideband_req(&req, msg);
1180 msg->path_msg = true;
1184 static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg,
1186 u8 vcpi, uint16_t pbn,
1187 u8 number_sdp_streams,
1188 u8 *sdp_stream_sink)
1190 struct drm_dp_sideband_msg_req_body req;
1192 memset(&req, 0, sizeof(req));
1193 req.req_type = DP_ALLOCATE_PAYLOAD;
1194 req.u.allocate_payload.port_number = port_num;
1195 req.u.allocate_payload.vcpi = vcpi;
1196 req.u.allocate_payload.pbn = pbn;
1197 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
1198 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
1199 number_sdp_streams);
1200 drm_dp_encode_sideband_req(&req, msg);
1201 msg->path_msg = true;
1204 static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
1205 int port_num, bool power_up)
1207 struct drm_dp_sideband_msg_req_body req;
1210 req.req_type = DP_POWER_UP_PHY;
1212 req.req_type = DP_POWER_DOWN_PHY;
1214 req.u.port_num.port_number = port_num;
1215 drm_dp_encode_sideband_req(&req, msg);
1216 msg->path_msg = true;
1220 build_query_stream_enc_status(struct drm_dp_sideband_msg_tx *msg, u8 stream_id,
1223 struct drm_dp_sideband_msg_req_body req;
1225 req.req_type = DP_QUERY_STREAM_ENC_STATUS;
1226 req.u.enc_status.stream_id = stream_id;
1227 memcpy(req.u.enc_status.client_id, q_id,
1228 sizeof(req.u.enc_status.client_id));
1229 req.u.enc_status.stream_event = 0;
1230 req.u.enc_status.valid_stream_event = false;
1231 req.u.enc_status.stream_behavior = 0;
1232 req.u.enc_status.valid_stream_behavior = false;
1234 drm_dp_encode_sideband_req(&req, msg);
1238 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1239 struct drm_dp_vcpi *vcpi)
1243 mutex_lock(&mgr->payload_lock);
1244 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
1245 if (ret > mgr->max_payloads) {
1247 drm_dbg_kms(mgr->dev, "out of payload ids %d\n", ret);
1251 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
1252 if (vcpi_ret > mgr->max_payloads) {
1254 drm_dbg_kms(mgr->dev, "out of vcpi ids %d\n", ret);
1258 set_bit(ret, &mgr->payload_mask);
1259 set_bit(vcpi_ret, &mgr->vcpi_mask);
1260 vcpi->vcpi = vcpi_ret + 1;
1261 mgr->proposed_vcpis[ret - 1] = vcpi;
1263 mutex_unlock(&mgr->payload_lock);
1267 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1275 mutex_lock(&mgr->payload_lock);
1276 drm_dbg_kms(mgr->dev, "putting payload %d\n", vcpi);
1277 clear_bit(vcpi - 1, &mgr->vcpi_mask);
1279 for (i = 0; i < mgr->max_payloads; i++) {
1280 if (mgr->proposed_vcpis[i] &&
1281 mgr->proposed_vcpis[i]->vcpi == vcpi) {
1282 mgr->proposed_vcpis[i] = NULL;
1283 clear_bit(i + 1, &mgr->payload_mask);
1286 mutex_unlock(&mgr->payload_lock);
1289 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
1290 struct drm_dp_sideband_msg_tx *txmsg)
1295 * All updates to txmsg->state are protected by mgr->qlock, and the two
1296 * cases we check here are terminal states. For those the barriers
1297 * provided by the wake_up/wait_event pair are enough.
1299 state = READ_ONCE(txmsg->state);
1300 return (state == DRM_DP_SIDEBAND_TX_RX ||
1301 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
1304 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
1305 struct drm_dp_sideband_msg_tx *txmsg)
1307 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1308 unsigned long wait_timeout = msecs_to_jiffies(4000);
1309 unsigned long wait_expires = jiffies + wait_timeout;
1314 * If the driver provides a way for this, change to
1315 * poll-waiting for the MST reply interrupt if we didn't receive
1316 * it for 50 msec. This would cater for cases where the HPD
1317 * pulse signal got lost somewhere, even though the sink raised
1318 * the corresponding MST interrupt correctly. One example is the
1319 * Club 3D CAC-1557 TypeC -> DP adapter which for some reason
1320 * filters out short pulses with a duration less than ~540 usec.
1322 * The poll period is 50 msec to avoid missing an interrupt
1323 * after the sink has cleared it (after a 110msec timeout
1324 * since it raised the interrupt).
1326 ret = wait_event_timeout(mgr->tx_waitq,
1327 check_txmsg_state(mgr, txmsg),
1328 mgr->cbs->poll_hpd_irq ?
1329 msecs_to_jiffies(50) :
1332 if (ret || !mgr->cbs->poll_hpd_irq ||
1333 time_after(jiffies, wait_expires))
1336 mgr->cbs->poll_hpd_irq(mgr);
1339 mutex_lock(&mgr->qlock);
1341 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
1346 drm_dbg_kms(mgr->dev, "timedout msg send %p %d %d\n",
1347 txmsg, txmsg->state, txmsg->seqno);
1349 /* dump some state */
1353 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
1354 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
1355 txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
1356 list_del(&txmsg->next);
1359 if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
1360 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1362 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
1364 mutex_unlock(&mgr->qlock);
1366 drm_dp_mst_kick_tx(mgr);
1370 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
1372 struct drm_dp_mst_branch *mstb;
1374 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
1380 memcpy(mstb->rad, rad, lct / 2);
1381 INIT_LIST_HEAD(&mstb->ports);
1382 kref_init(&mstb->topology_kref);
1383 kref_init(&mstb->malloc_kref);
1387 static void drm_dp_free_mst_branch_device(struct kref *kref)
1389 struct drm_dp_mst_branch *mstb =
1390 container_of(kref, struct drm_dp_mst_branch, malloc_kref);
1392 if (mstb->port_parent)
1393 drm_dp_mst_put_port_malloc(mstb->port_parent);
1399 * DOC: Branch device and port refcounting
1401 * Topology refcount overview
1402 * ~~~~~~~~~~~~~~~~~~~~~~~~~~
1404 * The refcounting schemes for &struct drm_dp_mst_branch and &struct
1405 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
1406 * two different kinds of refcounts: topology refcounts, and malloc refcounts.
1408 * Topology refcounts are not exposed to drivers, and are handled internally
1409 * by the DP MST helpers. The helpers use them in order to prevent the
1410 * in-memory topology state from being changed in the middle of critical
1411 * operations like changing the internal state of payload allocations. This
1412 * means each branch and port will be considered to be connected to the rest
1413 * of the topology until its topology refcount reaches zero. Additionally,
1414 * for ports this means that their associated &struct drm_connector will stay
1415 * registered with userspace until the port's refcount reaches 0.
1417 * Malloc refcount overview
1418 * ~~~~~~~~~~~~~~~~~~~~~~~~
1420 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct
1421 * drm_dp_mst_branch allocated even after all of its topology references have
1422 * been dropped, so that the driver or MST helpers can safely access each
1423 * branch's last known state before it was disconnected from the topology.
1424 * When the malloc refcount of a port or branch reaches 0, the memory
1425 * allocation containing the &struct drm_dp_mst_branch or &struct
1426 * drm_dp_mst_port respectively will be freed.
1428 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
1429 * to drivers. As of writing this documentation, there are no drivers that
1430 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
1431 * helpers. Exposing this API to drivers in a race-free manner would take more
1432 * tweaking of the refcounting scheme, however patches are welcome provided
1433 * there is a legitimate driver usecase for this.
1435 * Refcount relationships in a topology
1436 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1438 * Let's take a look at why the relationship between topology and malloc
1439 * refcounts is designed the way it is.
1441 * .. kernel-figure:: dp-mst/topology-figure-1.dot
1443 * An example of topology and malloc refs in a DP MST topology with two
1444 * active payloads. Topology refcount increments are indicated by solid
1445 * lines, and malloc refcount increments are indicated by dashed lines.
1446 * Each starts from the branch which incremented the refcount, and ends at
1447 * the branch to which the refcount belongs to, i.e. the arrow points the
1448 * same way as the C pointers used to reference a structure.
1450 * As you can see in the above figure, every branch increments the topology
1451 * refcount of its children, and increments the malloc refcount of its
1452 * parent. Additionally, every payload increments the malloc refcount of its
1453 * assigned port by 1.
1455 * So, what would happen if MSTB #3 from the above figure was unplugged from
1456 * the system, but the driver hadn't yet removed payload #2 from port #3? The
1457 * topology would start to look like the figure below.
1459 * .. kernel-figure:: dp-mst/topology-figure-2.dot
1461 * Ports and branch devices which have been released from memory are
1462 * colored grey, and references which have been removed are colored red.
1464 * Whenever a port or branch device's topology refcount reaches zero, it will
1465 * decrement the topology refcounts of all its children, the malloc refcount
1466 * of its parent, and finally its own malloc refcount. For MSTB #4 and port
1467 * #4, this means they both have been disconnected from the topology and freed
1468 * from memory. But, because payload #2 is still holding a reference to port
1469 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
1470 * is still accessible from memory. This also means port #3 has not yet
1471 * decremented the malloc refcount of MSTB #3, so its &struct
1472 * drm_dp_mst_branch will also stay allocated in memory until port #3's
1473 * malloc refcount reaches 0.
1475 * This relationship is necessary because in order to release payload #2, we
1476 * need to be able to figure out the last relative of port #3 that's still
1477 * connected to the topology. In this case, we would travel up the topology as
1480 * .. kernel-figure:: dp-mst/topology-figure-3.dot
1482 * And finally, remove payload #2 by communicating with port #2 through
1483 * sideband transactions.
1487 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
1489 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
1491 * Increments &drm_dp_mst_branch.malloc_kref. When
1492 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1493 * will be released and @mstb may no longer be used.
1495 * See also: drm_dp_mst_put_mstb_malloc()
1498 drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
1500 kref_get(&mstb->malloc_kref);
1501 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
1505 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
1507 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
1509 * Decrements &drm_dp_mst_branch.malloc_kref. When
1510 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1511 * will be released and @mstb may no longer be used.
1513 * See also: drm_dp_mst_get_mstb_malloc()
1516 drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
1518 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
1519 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
1522 static void drm_dp_free_mst_port(struct kref *kref)
1524 struct drm_dp_mst_port *port =
1525 container_of(kref, struct drm_dp_mst_port, malloc_kref);
1527 drm_dp_mst_put_mstb_malloc(port->parent);
1532 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
1533 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of
1535 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1536 * reaches 0, the memory allocation for @port will be released and @port may
1537 * no longer be used.
1539 * Because @port could potentially be freed at any time by the DP MST helpers
1540 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
1541 * function, drivers that which to make use of &struct drm_dp_mst_port should
1542 * ensure that they grab at least one main malloc reference to their MST ports
1543 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
1544 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
1546 * See also: drm_dp_mst_put_port_malloc()
1549 drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
1551 kref_get(&port->malloc_kref);
1552 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref));
1554 EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
1557 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
1558 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
1560 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1561 * reaches 0, the memory allocation for @port will be released and @port may
1562 * no longer be used.
1564 * See also: drm_dp_mst_get_port_malloc()
1567 drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
1569 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
1570 kref_put(&port->malloc_kref, drm_dp_free_mst_port);
1572 EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
1574 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
1576 #define STACK_DEPTH 8
1578 static noinline void
1579 __topology_ref_save(struct drm_dp_mst_topology_mgr *mgr,
1580 struct drm_dp_mst_topology_ref_history *history,
1581 enum drm_dp_mst_topology_ref_type type)
1583 struct drm_dp_mst_topology_ref_entry *entry = NULL;
1584 depot_stack_handle_t backtrace;
1585 ulong stack_entries[STACK_DEPTH];
1589 n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1);
1590 backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL);
1594 /* Try to find an existing entry for this backtrace */
1595 for (i = 0; i < history->len; i++) {
1596 if (history->entries[i].backtrace == backtrace) {
1597 entry = &history->entries[i];
1602 /* Otherwise add one */
1604 struct drm_dp_mst_topology_ref_entry *new;
1605 int new_len = history->len + 1;
1607 new = krealloc(history->entries, sizeof(*new) * new_len,
1612 entry = &new[history->len];
1613 history->len = new_len;
1614 history->entries = new;
1616 entry->backtrace = backtrace;
1621 entry->ts_nsec = ktime_get_ns();
1625 topology_ref_history_cmp(const void *a, const void *b)
1627 const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b;
1629 if (entry_a->ts_nsec > entry_b->ts_nsec)
1631 else if (entry_a->ts_nsec < entry_b->ts_nsec)
1637 static inline const char *
1638 topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type)
1640 if (type == DRM_DP_MST_TOPOLOGY_REF_GET)
1647 __dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history,
1648 void *ptr, const char *type_str)
1650 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1651 char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1660 /* First, sort the list so that it goes from oldest to newest
1663 sort(history->entries, history->len, sizeof(*history->entries),
1664 topology_ref_history_cmp, NULL);
1666 drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n",
1669 for (i = 0; i < history->len; i++) {
1670 const struct drm_dp_mst_topology_ref_entry *entry =
1671 &history->entries[i];
1672 u64 ts_nsec = entry->ts_nsec;
1673 u32 rem_nsec = do_div(ts_nsec, 1000000000);
1675 stack_depot_snprint(entry->backtrace, buf, PAGE_SIZE, 4);
1677 drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s",
1679 topology_ref_type_to_str(entry->type),
1680 ts_nsec, rem_nsec / 1000, buf);
1683 /* Now free the history, since this is the only time we expose it */
1684 kfree(history->entries);
1689 static __always_inline void
1690 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb)
1692 __dump_topology_ref_history(&mstb->topology_ref_history, mstb,
1696 static __always_inline void
1697 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port)
1699 __dump_topology_ref_history(&port->topology_ref_history, port,
1703 static __always_inline void
1704 save_mstb_topology_ref(struct drm_dp_mst_branch *mstb,
1705 enum drm_dp_mst_topology_ref_type type)
1707 __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type);
1710 static __always_inline void
1711 save_port_topology_ref(struct drm_dp_mst_port *port,
1712 enum drm_dp_mst_topology_ref_type type)
1714 __topology_ref_save(port->mgr, &port->topology_ref_history, type);
1718 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr)
1720 mutex_lock(&mgr->topology_ref_history_lock);
1724 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr)
1726 mutex_unlock(&mgr->topology_ref_history_lock);
1730 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {}
1732 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {}
1734 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {}
1736 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {}
1737 #define save_mstb_topology_ref(mstb, type)
1738 #define save_port_topology_ref(port, type)
1741 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
1743 struct drm_dp_mst_branch *mstb =
1744 container_of(kref, struct drm_dp_mst_branch, topology_kref);
1745 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1747 drm_dp_mst_dump_mstb_topology_history(mstb);
1749 INIT_LIST_HEAD(&mstb->destroy_next);
1752 * This can get called under mgr->mutex, so we need to perform the
1753 * actual destruction of the mstb in another worker
1755 mutex_lock(&mgr->delayed_destroy_lock);
1756 list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list);
1757 mutex_unlock(&mgr->delayed_destroy_lock);
1758 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1762 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1763 * branch device unless it's zero
1764 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
1766 * Attempts to grab a topology reference to @mstb, if it hasn't yet been
1767 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
1768 * reached 0). Holding a topology reference implies that a malloc reference
1769 * will be held to @mstb as long as the user holds the topology reference.
1771 * Care should be taken to ensure that the user has at least one malloc
1772 * reference to @mstb. If you already have a topology reference to @mstb, you
1773 * should use drm_dp_mst_topology_get_mstb() instead.
1776 * drm_dp_mst_topology_get_mstb()
1777 * drm_dp_mst_topology_put_mstb()
1780 * * 1: A topology reference was grabbed successfully
1781 * * 0: @port is no longer in the topology, no reference was grabbed
1783 static int __must_check
1784 drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
1788 topology_ref_history_lock(mstb->mgr);
1789 ret = kref_get_unless_zero(&mstb->topology_kref);
1791 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1792 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1795 topology_ref_history_unlock(mstb->mgr);
1801 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
1803 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
1805 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or
1806 * not it's already reached 0. This is only valid to use in scenarios where
1807 * you are already guaranteed to have at least one active topology reference
1808 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
1811 * drm_dp_mst_topology_try_get_mstb()
1812 * drm_dp_mst_topology_put_mstb()
1814 static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
1816 topology_ref_history_lock(mstb->mgr);
1818 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1819 WARN_ON(kref_read(&mstb->topology_kref) == 0);
1820 kref_get(&mstb->topology_kref);
1821 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1823 topology_ref_history_unlock(mstb->mgr);
1827 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
1829 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from
1831 * Releases a topology reference from @mstb by decrementing
1832 * &drm_dp_mst_branch.topology_kref.
1835 * drm_dp_mst_topology_try_get_mstb()
1836 * drm_dp_mst_topology_get_mstb()
1839 drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
1841 topology_ref_history_lock(mstb->mgr);
1843 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref) - 1);
1844 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT);
1846 topology_ref_history_unlock(mstb->mgr);
1847 kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
1850 static void drm_dp_destroy_port(struct kref *kref)
1852 struct drm_dp_mst_port *port =
1853 container_of(kref, struct drm_dp_mst_port, topology_kref);
1854 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1856 drm_dp_mst_dump_port_topology_history(port);
1858 /* There's nothing that needs locking to destroy an input port yet */
1860 drm_dp_mst_put_port_malloc(port);
1864 kfree(port->cached_edid);
1867 * we can't destroy the connector here, as we might be holding the
1868 * mode_config.mutex from an EDID retrieval
1870 mutex_lock(&mgr->delayed_destroy_lock);
1871 list_add(&port->next, &mgr->destroy_port_list);
1872 mutex_unlock(&mgr->delayed_destroy_lock);
1873 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1877 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
1878 * port unless it's zero
1879 * @port: &struct drm_dp_mst_port to increment the topology refcount of
1881 * Attempts to grab a topology reference to @port, if it hasn't yet been
1882 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
1883 * 0). Holding a topology reference implies that a malloc reference will be
1884 * held to @port as long as the user holds the topology reference.
1886 * Care should be taken to ensure that the user has at least one malloc
1887 * reference to @port. If you already have a topology reference to @port, you
1888 * should use drm_dp_mst_topology_get_port() instead.
1891 * drm_dp_mst_topology_get_port()
1892 * drm_dp_mst_topology_put_port()
1895 * * 1: A topology reference was grabbed successfully
1896 * * 0: @port is no longer in the topology, no reference was grabbed
1898 static int __must_check
1899 drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
1903 topology_ref_history_lock(port->mgr);
1904 ret = kref_get_unless_zero(&port->topology_kref);
1906 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref));
1907 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1910 topology_ref_history_unlock(port->mgr);
1915 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
1916 * @port: The &struct drm_dp_mst_port to increment the topology refcount of
1918 * Increments &drm_dp_mst_port.topology_refcount without checking whether or
1919 * not it's already reached 0. This is only valid to use in scenarios where
1920 * you are already guaranteed to have at least one active topology reference
1921 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
1924 * drm_dp_mst_topology_try_get_port()
1925 * drm_dp_mst_topology_put_port()
1927 static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
1929 topology_ref_history_lock(port->mgr);
1931 WARN_ON(kref_read(&port->topology_kref) == 0);
1932 kref_get(&port->topology_kref);
1933 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref));
1934 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1936 topology_ref_history_unlock(port->mgr);
1940 * drm_dp_mst_topology_put_port() - release a topology reference to a port
1941 * @port: The &struct drm_dp_mst_port to release the topology reference from
1943 * Releases a topology reference from @port by decrementing
1944 * &drm_dp_mst_port.topology_kref.
1947 * drm_dp_mst_topology_try_get_port()
1948 * drm_dp_mst_topology_get_port()
1950 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
1952 topology_ref_history_lock(port->mgr);
1954 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref) - 1);
1955 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT);
1957 topology_ref_history_unlock(port->mgr);
1958 kref_put(&port->topology_kref, drm_dp_destroy_port);
1961 static struct drm_dp_mst_branch *
1962 drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
1963 struct drm_dp_mst_branch *to_find)
1965 struct drm_dp_mst_port *port;
1966 struct drm_dp_mst_branch *rmstb;
1968 if (to_find == mstb)
1971 list_for_each_entry(port, &mstb->ports, next) {
1973 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1974 port->mstb, to_find);
1982 static struct drm_dp_mst_branch *
1983 drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
1984 struct drm_dp_mst_branch *mstb)
1986 struct drm_dp_mst_branch *rmstb = NULL;
1988 mutex_lock(&mgr->lock);
1989 if (mgr->mst_primary) {
1990 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1991 mgr->mst_primary, mstb);
1993 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
1996 mutex_unlock(&mgr->lock);
2000 static struct drm_dp_mst_port *
2001 drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
2002 struct drm_dp_mst_port *to_find)
2004 struct drm_dp_mst_port *port, *mport;
2006 list_for_each_entry(port, &mstb->ports, next) {
2007 if (port == to_find)
2011 mport = drm_dp_mst_topology_get_port_validated_locked(
2012 port->mstb, to_find);
2020 static struct drm_dp_mst_port *
2021 drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
2022 struct drm_dp_mst_port *port)
2024 struct drm_dp_mst_port *rport = NULL;
2026 mutex_lock(&mgr->lock);
2027 if (mgr->mst_primary) {
2028 rport = drm_dp_mst_topology_get_port_validated_locked(
2029 mgr->mst_primary, port);
2031 if (rport && !drm_dp_mst_topology_try_get_port(rport))
2034 mutex_unlock(&mgr->lock);
2038 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
2040 struct drm_dp_mst_port *port;
2043 list_for_each_entry(port, &mstb->ports, next) {
2044 if (port->port_num == port_num) {
2045 ret = drm_dp_mst_topology_try_get_port(port);
2046 return ret ? port : NULL;
2054 * calculate a new RAD for this MST branch device
2055 * if parent has an LCT of 2 then it has 1 nibble of RAD,
2056 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
2058 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
2061 int parent_lct = port->parent->lct;
2063 int idx = (parent_lct - 1) / 2;
2065 if (parent_lct > 1) {
2066 memcpy(rad, port->parent->rad, idx + 1);
2067 shift = (parent_lct % 2) ? 4 : 0;
2071 rad[idx] |= port->port_num << shift;
2072 return parent_lct + 1;
2075 static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs)
2078 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2079 case DP_PEER_DEVICE_SST_SINK:
2081 case DP_PEER_DEVICE_MST_BRANCHING:
2082 /* For sst branch device */
2092 drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
2095 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2096 struct drm_dp_mst_branch *mstb;
2100 if (port->pdt == new_pdt && port->mcs == new_mcs)
2103 /* Teardown the old pdt, if there is one */
2104 if (port->pdt != DP_PEER_DEVICE_NONE) {
2105 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2107 * If the new PDT would also have an i2c bus,
2108 * don't bother with reregistering it
2110 if (new_pdt != DP_PEER_DEVICE_NONE &&
2111 drm_dp_mst_is_end_device(new_pdt, new_mcs)) {
2112 port->pdt = new_pdt;
2113 port->mcs = new_mcs;
2117 /* remove i2c over sideband */
2118 drm_dp_mst_unregister_i2c_bus(port);
2120 mutex_lock(&mgr->lock);
2121 drm_dp_mst_topology_put_mstb(port->mstb);
2123 mutex_unlock(&mgr->lock);
2127 port->pdt = new_pdt;
2128 port->mcs = new_mcs;
2130 if (port->pdt != DP_PEER_DEVICE_NONE) {
2131 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2132 /* add i2c over sideband */
2133 ret = drm_dp_mst_register_i2c_bus(port);
2135 lct = drm_dp_calculate_rad(port, rad);
2136 mstb = drm_dp_add_mst_branch_device(lct, rad);
2139 drm_err(mgr->dev, "Failed to create MSTB for port %p", port);
2143 mutex_lock(&mgr->lock);
2145 mstb->mgr = port->mgr;
2146 mstb->port_parent = port;
2149 * Make sure this port's memory allocation stays
2150 * around until its child MSTB releases it
2152 drm_dp_mst_get_port_malloc(port);
2153 mutex_unlock(&mgr->lock);
2155 /* And make sure we send a link address for this */
2162 port->pdt = DP_PEER_DEVICE_NONE;
2167 * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
2168 * @aux: Fake sideband AUX CH
2169 * @offset: address of the (first) register to read
2170 * @buffer: buffer to store the register values
2171 * @size: number of bytes in @buffer
2173 * Performs the same functionality for remote devices via
2174 * sideband messaging as drm_dp_dpcd_read() does for local
2175 * devices via actual AUX CH.
2177 * Return: Number of bytes read, or negative error code on failure.
2179 ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
2180 unsigned int offset, void *buffer, size_t size)
2182 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2185 return drm_dp_send_dpcd_read(port->mgr, port,
2186 offset, size, buffer);
2190 * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
2191 * @aux: Fake sideband AUX CH
2192 * @offset: address of the (first) register to write
2193 * @buffer: buffer containing the values to write
2194 * @size: number of bytes in @buffer
2196 * Performs the same functionality for remote devices via
2197 * sideband messaging as drm_dp_dpcd_write() does for local
2198 * devices via actual AUX CH.
2200 * Return: number of bytes written on success, negative error code on failure.
2202 ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
2203 unsigned int offset, void *buffer, size_t size)
2205 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2208 return drm_dp_send_dpcd_write(port->mgr, port,
2209 offset, size, buffer);
2212 static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
2216 memcpy(mstb->guid, guid, 16);
2218 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
2219 if (mstb->port_parent) {
2220 ret = drm_dp_send_dpcd_write(mstb->mgr,
2222 DP_GUID, 16, mstb->guid);
2224 ret = drm_dp_dpcd_write(mstb->mgr->aux,
2225 DP_GUID, mstb->guid, 16);
2229 if (ret < 16 && ret > 0)
2232 return ret == 16 ? 0 : ret;
2235 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
2238 size_t proppath_size)
2243 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
2244 for (i = 0; i < (mstb->lct - 1); i++) {
2245 int shift = (i % 2) ? 0 : 4;
2246 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
2248 snprintf(temp, sizeof(temp), "-%d", port_num);
2249 strlcat(proppath, temp, proppath_size);
2251 snprintf(temp, sizeof(temp), "-%d", pnum);
2252 strlcat(proppath, temp, proppath_size);
2256 * drm_dp_mst_connector_late_register() - Late MST connector registration
2257 * @connector: The MST connector
2258 * @port: The MST port for this connector
2260 * Helper to register the remote aux device for this MST port. Drivers should
2261 * call this from their mst connector's late_register hook to enable MST aux
2264 * Return: 0 on success, negative error code on failure.
2266 int drm_dp_mst_connector_late_register(struct drm_connector *connector,
2267 struct drm_dp_mst_port *port)
2269 drm_dbg_kms(port->mgr->dev, "registering %s remote bus for %s\n",
2270 port->aux.name, connector->kdev->kobj.name);
2272 port->aux.dev = connector->kdev;
2273 return drm_dp_aux_register_devnode(&port->aux);
2275 EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
2278 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
2279 * @connector: The MST connector
2280 * @port: The MST port for this connector
2282 * Helper to unregister the remote aux device for this MST port, registered by
2283 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst
2284 * connector's early_unregister hook.
2286 void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
2287 struct drm_dp_mst_port *port)
2289 drm_dbg_kms(port->mgr->dev, "unregistering %s remote bus for %s\n",
2290 port->aux.name, connector->kdev->kobj.name);
2291 drm_dp_aux_unregister_devnode(&port->aux);
2293 EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
2296 drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
2297 struct drm_dp_mst_port *port)
2299 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2303 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
2304 port->connector = mgr->cbs->add_connector(mgr, port, proppath);
2305 if (!port->connector) {
2310 if (port->pdt != DP_PEER_DEVICE_NONE &&
2311 drm_dp_mst_is_end_device(port->pdt, port->mcs) &&
2312 port->port_num >= DP_MST_LOGICAL_PORT_0)
2313 port->cached_edid = drm_get_edid(port->connector,
2316 drm_connector_register(port->connector);
2320 drm_err(mgr->dev, "Failed to create connector for port %p: %d\n", port, ret);
2324 * Drop a topology reference, and unlink the port from the in-memory topology
2328 drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr,
2329 struct drm_dp_mst_port *port)
2331 mutex_lock(&mgr->lock);
2332 port->parent->num_ports--;
2333 list_del(&port->next);
2334 mutex_unlock(&mgr->lock);
2335 drm_dp_mst_topology_put_port(port);
2338 static struct drm_dp_mst_port *
2339 drm_dp_mst_add_port(struct drm_device *dev,
2340 struct drm_dp_mst_topology_mgr *mgr,
2341 struct drm_dp_mst_branch *mstb, u8 port_number)
2343 struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
2348 kref_init(&port->topology_kref);
2349 kref_init(&port->malloc_kref);
2350 port->parent = mstb;
2351 port->port_num = port_number;
2353 port->aux.name = "DPMST";
2354 port->aux.dev = dev->dev;
2355 port->aux.is_remote = true;
2357 /* initialize the MST downstream port's AUX crc work queue */
2358 port->aux.drm_dev = dev;
2359 drm_dp_remote_aux_init(&port->aux);
2362 * Make sure the memory allocation for our parent branch stays
2363 * around until our own memory allocation is released
2365 drm_dp_mst_get_mstb_malloc(mstb);
2371 drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
2372 struct drm_device *dev,
2373 struct drm_dp_link_addr_reply_port *port_msg)
2375 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2376 struct drm_dp_mst_port *port;
2377 int old_ddps = 0, ret;
2378 u8 new_pdt = DP_PEER_DEVICE_NONE;
2380 bool created = false, send_link_addr = false, changed = false;
2382 port = drm_dp_get_port(mstb, port_msg->port_number);
2384 port = drm_dp_mst_add_port(dev, mgr, mstb,
2385 port_msg->port_number);
2390 } else if (!port->input && port_msg->input_port && port->connector) {
2391 /* Since port->connector can't be changed here, we create a
2392 * new port if input_port changes from 0 to 1
2394 drm_dp_mst_topology_unlink_port(mgr, port);
2395 drm_dp_mst_topology_put_port(port);
2396 port = drm_dp_mst_add_port(dev, mgr, mstb,
2397 port_msg->port_number);
2402 } else if (port->input && !port_msg->input_port) {
2404 } else if (port->connector) {
2405 /* We're updating a port that's exposed to userspace, so do it
2408 drm_modeset_lock(&mgr->base.lock, NULL);
2410 old_ddps = port->ddps;
2411 changed = port->ddps != port_msg->ddps ||
2413 (port->ldps != port_msg->legacy_device_plug_status ||
2414 port->dpcd_rev != port_msg->dpcd_revision ||
2415 port->mcs != port_msg->mcs ||
2416 port->pdt != port_msg->peer_device_type ||
2417 port->num_sdp_stream_sinks !=
2418 port_msg->num_sdp_stream_sinks));
2421 port->input = port_msg->input_port;
2423 new_pdt = port_msg->peer_device_type;
2424 new_mcs = port_msg->mcs;
2425 port->ddps = port_msg->ddps;
2426 port->ldps = port_msg->legacy_device_plug_status;
2427 port->dpcd_rev = port_msg->dpcd_revision;
2428 port->num_sdp_streams = port_msg->num_sdp_streams;
2429 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
2431 /* manage mstb port lists with mgr lock - take a reference
2434 mutex_lock(&mgr->lock);
2435 drm_dp_mst_topology_get_port(port);
2436 list_add(&port->next, &mstb->ports);
2438 mutex_unlock(&mgr->lock);
2442 * Reprobe PBN caps on both hotplug, and when re-probing the link
2443 * for our parent mstb
2445 if (old_ddps != port->ddps || !created) {
2446 if (port->ddps && !port->input) {
2447 ret = drm_dp_send_enum_path_resources(mgr, mstb,
2456 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2458 send_link_addr = true;
2459 } else if (ret < 0) {
2460 drm_err(dev, "Failed to change PDT on port %p: %d\n", port, ret);
2465 * If this port wasn't just created, then we're reprobing because
2466 * we're coming out of suspend. In this case, always resend the link
2467 * address if there's an MSTB on this port
2469 if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
2471 send_link_addr = true;
2473 if (port->connector)
2474 drm_modeset_unlock(&mgr->base.lock);
2475 else if (!port->input)
2476 drm_dp_mst_port_add_connector(mstb, port);
2478 if (send_link_addr && port->mstb) {
2479 ret = drm_dp_send_link_address(mgr, port->mstb);
2480 if (ret == 1) /* MSTB below us changed */
2486 /* put reference to this port */
2487 drm_dp_mst_topology_put_port(port);
2491 drm_dp_mst_topology_unlink_port(mgr, port);
2492 if (port->connector)
2493 drm_modeset_unlock(&mgr->base.lock);
2495 drm_dp_mst_topology_put_port(port);
2500 drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
2501 struct drm_dp_connection_status_notify *conn_stat)
2503 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2504 struct drm_dp_mst_port *port;
2508 bool dowork = false, create_connector = false;
2510 port = drm_dp_get_port(mstb, conn_stat->port_number);
2514 if (port->connector) {
2515 if (!port->input && conn_stat->input_port) {
2517 * We can't remove a connector from an already exposed
2518 * port, so just throw the port out and make sure we
2519 * reprobe the link address of it's parent MSTB
2521 drm_dp_mst_topology_unlink_port(mgr, port);
2522 mstb->link_address_sent = false;
2527 /* Locking is only needed if the port's exposed to userspace */
2528 drm_modeset_lock(&mgr->base.lock, NULL);
2529 } else if (port->input && !conn_stat->input_port) {
2530 create_connector = true;
2531 /* Reprobe link address so we get num_sdp_streams */
2532 mstb->link_address_sent = false;
2536 old_ddps = port->ddps;
2537 port->input = conn_stat->input_port;
2538 port->ldps = conn_stat->legacy_device_plug_status;
2539 port->ddps = conn_stat->displayport_device_plug_status;
2541 if (old_ddps != port->ddps) {
2542 if (port->ddps && !port->input)
2543 drm_dp_send_enum_path_resources(mgr, mstb, port);
2548 new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
2549 new_mcs = conn_stat->message_capability_status;
2550 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2553 } else if (ret < 0) {
2554 drm_err(mgr->dev, "Failed to change PDT for port %p: %d\n", port, ret);
2558 if (port->connector)
2559 drm_modeset_unlock(&mgr->base.lock);
2560 else if (create_connector)
2561 drm_dp_mst_port_add_connector(mstb, port);
2564 drm_dp_mst_topology_put_port(port);
2566 queue_work(system_long_wq, &mstb->mgr->work);
2569 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
2572 struct drm_dp_mst_branch *mstb;
2573 struct drm_dp_mst_port *port;
2575 /* find the port by iterating down */
2577 mutex_lock(&mgr->lock);
2578 mstb = mgr->mst_primary;
2583 for (i = 0; i < lct - 1; i++) {
2584 int shift = (i % 2) ? 0 : 4;
2585 int port_num = (rad[i / 2] >> shift) & 0xf;
2587 list_for_each_entry(port, &mstb->ports, next) {
2588 if (port->port_num == port_num) {
2592 "failed to lookup MSTB with lct %d, rad %02x\n",
2601 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2605 mutex_unlock(&mgr->lock);
2609 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
2610 struct drm_dp_mst_branch *mstb,
2611 const uint8_t *guid)
2613 struct drm_dp_mst_branch *found_mstb;
2614 struct drm_dp_mst_port *port;
2616 if (memcmp(mstb->guid, guid, 16) == 0)
2620 list_for_each_entry(port, &mstb->ports, next) {
2624 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
2633 static struct drm_dp_mst_branch *
2634 drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
2635 const uint8_t *guid)
2637 struct drm_dp_mst_branch *mstb;
2640 /* find the port by iterating down */
2641 mutex_lock(&mgr->lock);
2643 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
2645 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2650 mutex_unlock(&mgr->lock);
2654 static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2655 struct drm_dp_mst_branch *mstb)
2657 struct drm_dp_mst_port *port;
2659 bool changed = false;
2661 if (!mstb->link_address_sent) {
2662 ret = drm_dp_send_link_address(mgr, mstb);
2669 list_for_each_entry(port, &mstb->ports, next) {
2670 if (port->input || !port->ddps || !port->mstb)
2673 ret = drm_dp_check_and_send_link_address(mgr, port->mstb);
2683 static void drm_dp_mst_link_probe_work(struct work_struct *work)
2685 struct drm_dp_mst_topology_mgr *mgr =
2686 container_of(work, struct drm_dp_mst_topology_mgr, work);
2687 struct drm_device *dev = mgr->dev;
2688 struct drm_dp_mst_branch *mstb;
2690 bool clear_payload_id_table;
2692 mutex_lock(&mgr->probe_lock);
2694 mutex_lock(&mgr->lock);
2695 clear_payload_id_table = !mgr->payload_id_table_cleared;
2696 mgr->payload_id_table_cleared = true;
2698 mstb = mgr->mst_primary;
2700 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2704 mutex_unlock(&mgr->lock);
2706 mutex_unlock(&mgr->probe_lock);
2711 * Certain branch devices seem to incorrectly report an available_pbn
2712 * of 0 on downstream sinks, even after clearing the
2713 * DP_PAYLOAD_ALLOCATE_* registers in
2714 * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
2715 * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
2716 * things work again.
2718 if (clear_payload_id_table) {
2719 drm_dbg_kms(dev, "Clearing payload ID table\n");
2720 drm_dp_send_clear_payload_id_table(mgr, mstb);
2723 ret = drm_dp_check_and_send_link_address(mgr, mstb);
2724 drm_dp_mst_topology_put_mstb(mstb);
2726 mutex_unlock(&mgr->probe_lock);
2728 drm_kms_helper_hotplug_event(dev);
2731 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
2736 if (memchr_inv(guid, 0, 16))
2739 salt = get_jiffies_64();
2741 memcpy(&guid[0], &salt, sizeof(u64));
2742 memcpy(&guid[8], &salt, sizeof(u64));
2747 static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg,
2748 u8 port_num, u32 offset, u8 num_bytes)
2750 struct drm_dp_sideband_msg_req_body req;
2752 req.req_type = DP_REMOTE_DPCD_READ;
2753 req.u.dpcd_read.port_number = port_num;
2754 req.u.dpcd_read.dpcd_address = offset;
2755 req.u.dpcd_read.num_bytes = num_bytes;
2756 drm_dp_encode_sideband_req(&req, msg);
2759 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
2760 bool up, u8 *msg, int len)
2763 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
2764 int tosend, total, offset;
2771 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
2773 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
2776 if (ret != tosend) {
2777 if (ret == -EIO && retries < 5) {
2781 drm_dbg_kms(mgr->dev, "failed to dpcd write %d %d\n", tosend, ret);
2787 } while (total > 0);
2791 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
2792 struct drm_dp_sideband_msg_tx *txmsg)
2794 struct drm_dp_mst_branch *mstb = txmsg->dst;
2797 req_type = txmsg->msg[0] & 0x7f;
2798 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
2799 req_type == DP_RESOURCE_STATUS_NOTIFY ||
2800 req_type == DP_CLEAR_PAYLOAD_ID_TABLE)
2804 hdr->path_msg = txmsg->path_msg;
2805 if (hdr->broadcast) {
2809 hdr->lct = mstb->lct;
2810 hdr->lcr = mstb->lct - 1;
2813 memcpy(hdr->rad, mstb->rad, hdr->lct / 2);
2818 * process a single block of the next message in the sideband queue
2820 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2821 struct drm_dp_sideband_msg_tx *txmsg,
2825 struct drm_dp_sideband_msg_hdr hdr;
2826 int len, space, idx, tosend;
2829 if (txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
2832 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
2834 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED)
2835 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
2837 /* make hdr from dst mst */
2838 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
2842 /* amount left to send in this message */
2843 len = txmsg->cur_len - txmsg->cur_offset;
2845 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
2846 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
2848 tosend = min(len, space);
2849 if (len == txmsg->cur_len)
2855 hdr.msg_len = tosend + 1;
2856 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
2857 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
2858 /* add crc at end */
2859 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
2862 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
2864 if (drm_debug_enabled(DRM_UT_DP)) {
2865 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2867 drm_printf(&p, "sideband msg failed to send\n");
2868 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2873 txmsg->cur_offset += tosend;
2874 if (txmsg->cur_offset == txmsg->cur_len) {
2875 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
2881 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
2883 struct drm_dp_sideband_msg_tx *txmsg;
2886 WARN_ON(!mutex_is_locked(&mgr->qlock));
2888 /* construct a chunk from the first msg in the tx_msg queue */
2889 if (list_empty(&mgr->tx_msg_downq))
2892 txmsg = list_first_entry(&mgr->tx_msg_downq,
2893 struct drm_dp_sideband_msg_tx, next);
2894 ret = process_single_tx_qlock(mgr, txmsg, false);
2896 drm_dbg_kms(mgr->dev, "failed to send msg in q %d\n", ret);
2897 list_del(&txmsg->next);
2898 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
2899 wake_up_all(&mgr->tx_waitq);
2903 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
2904 struct drm_dp_sideband_msg_tx *txmsg)
2906 mutex_lock(&mgr->qlock);
2907 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
2909 if (drm_debug_enabled(DRM_UT_DP)) {
2910 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2912 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2915 if (list_is_singular(&mgr->tx_msg_downq))
2916 process_single_down_tx_qlock(mgr);
2917 mutex_unlock(&mgr->qlock);
2921 drm_dp_dump_link_address(const struct drm_dp_mst_topology_mgr *mgr,
2922 struct drm_dp_link_address_ack_reply *reply)
2924 struct drm_dp_link_addr_reply_port *port_reply;
2927 for (i = 0; i < reply->nports; i++) {
2928 port_reply = &reply->ports[i];
2929 drm_dbg_kms(mgr->dev,
2930 "port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n",
2932 port_reply->input_port,
2933 port_reply->peer_device_type,
2934 port_reply->port_number,
2935 port_reply->dpcd_revision,
2938 port_reply->legacy_device_plug_status,
2939 port_reply->num_sdp_streams,
2940 port_reply->num_sdp_stream_sinks);
2944 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2945 struct drm_dp_mst_branch *mstb)
2947 struct drm_dp_sideband_msg_tx *txmsg;
2948 struct drm_dp_link_address_ack_reply *reply;
2949 struct drm_dp_mst_port *port, *tmp;
2950 int i, ret, port_mask = 0;
2951 bool changed = false;
2953 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2958 build_link_address(txmsg);
2960 mstb->link_address_sent = true;
2961 drm_dp_queue_down_tx(mgr, txmsg);
2963 /* FIXME: Actually do some real error handling here */
2964 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2966 drm_err(mgr->dev, "Sending link address failed with %d\n", ret);
2969 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2970 drm_err(mgr->dev, "link address NAK received\n");
2975 reply = &txmsg->reply.u.link_addr;
2976 drm_dbg_kms(mgr->dev, "link address reply: %d\n", reply->nports);
2977 drm_dp_dump_link_address(mgr, reply);
2979 ret = drm_dp_check_mstb_guid(mstb, reply->guid);
2983 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf));
2984 drm_err(mgr->dev, "GUID check on %s failed: %d\n", buf, ret);
2988 for (i = 0; i < reply->nports; i++) {
2989 port_mask |= BIT(reply->ports[i].port_number);
2990 ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev,
2998 /* Prune any ports that are currently a part of mstb in our in-memory
2999 * topology, but were not seen in this link address. Usually this
3000 * means that they were removed while the topology was out of sync,
3001 * e.g. during suspend/resume
3003 mutex_lock(&mgr->lock);
3004 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
3005 if (port_mask & BIT(port->port_num))
3008 drm_dbg_kms(mgr->dev, "port %d was not in link address, removing\n",
3010 list_del(&port->next);
3011 drm_dp_mst_topology_put_port(port);
3014 mutex_unlock(&mgr->lock);
3018 mstb->link_address_sent = false;
3020 return ret < 0 ? ret : changed;
3024 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
3025 struct drm_dp_mst_branch *mstb)
3027 struct drm_dp_sideband_msg_tx *txmsg;
3030 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3035 build_clear_payload_id_table(txmsg);
3037 drm_dp_queue_down_tx(mgr, txmsg);
3039 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3040 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3041 drm_dbg_kms(mgr->dev, "clear payload table id nak received\n");
3047 drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
3048 struct drm_dp_mst_branch *mstb,
3049 struct drm_dp_mst_port *port)
3051 struct drm_dp_enum_path_resources_ack_reply *path_res;
3052 struct drm_dp_sideband_msg_tx *txmsg;
3055 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3060 build_enum_path_resources(txmsg, port->port_num);
3062 drm_dp_queue_down_tx(mgr, txmsg);
3064 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3067 path_res = &txmsg->reply.u.path_resources;
3069 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3070 drm_dbg_kms(mgr->dev, "enum path resources nak received\n");
3072 if (port->port_num != path_res->port_number)
3073 DRM_ERROR("got incorrect port in response\n");
3075 drm_dbg_kms(mgr->dev, "enum path resources %d: %d %d\n",
3076 path_res->port_number,
3077 path_res->full_payload_bw_number,
3078 path_res->avail_payload_bw_number);
3081 * If something changed, make sure we send a
3084 if (port->full_pbn != path_res->full_payload_bw_number ||
3085 port->fec_capable != path_res->fec_capable)
3088 port->full_pbn = path_res->full_payload_bw_number;
3089 port->fec_capable = path_res->fec_capable;
3097 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
3099 if (!mstb->port_parent)
3102 if (mstb->port_parent->mstb != mstb)
3103 return mstb->port_parent;
3105 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
3109 * Searches upwards in the topology starting from mstb to try to find the
3110 * closest available parent of mstb that's still connected to the rest of the
3111 * topology. This can be used in order to perform operations like releasing
3112 * payloads, where the branch device which owned the payload may no longer be
3113 * around and thus would require that the payload on the last living relative
3116 static struct drm_dp_mst_branch *
3117 drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
3118 struct drm_dp_mst_branch *mstb,
3121 struct drm_dp_mst_branch *rmstb = NULL;
3122 struct drm_dp_mst_port *found_port;
3124 mutex_lock(&mgr->lock);
3125 if (!mgr->mst_primary)
3129 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
3133 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
3134 rmstb = found_port->parent;
3135 *port_num = found_port->port_num;
3137 /* Search again, starting from this parent */
3138 mstb = found_port->parent;
3142 mutex_unlock(&mgr->lock);
3146 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
3147 struct drm_dp_mst_port *port,
3151 struct drm_dp_sideband_msg_tx *txmsg;
3152 struct drm_dp_mst_branch *mstb;
3154 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
3157 port_num = port->port_num;
3158 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3160 mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
3168 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3174 for (i = 0; i < port->num_sdp_streams; i++)
3178 build_allocate_payload(txmsg, port_num,
3180 pbn, port->num_sdp_streams, sinks);
3182 drm_dp_queue_down_tx(mgr, txmsg);
3185 * FIXME: there is a small chance that between getting the last
3186 * connected mstb and sending the payload message, the last connected
3187 * mstb could also be removed from the topology. In the future, this
3188 * needs to be fixed by restarting the
3189 * drm_dp_get_last_connected_port_and_mstb() search in the event of a
3190 * timeout if the topology is still connected to the system.
3192 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3194 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3201 drm_dp_mst_topology_put_mstb(mstb);
3205 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
3206 struct drm_dp_mst_port *port, bool power_up)
3208 struct drm_dp_sideband_msg_tx *txmsg;
3211 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3215 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3217 drm_dp_mst_topology_put_port(port);
3221 txmsg->dst = port->parent;
3222 build_power_updown_phy(txmsg, port->port_num, power_up);
3223 drm_dp_queue_down_tx(mgr, txmsg);
3225 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
3227 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3233 drm_dp_mst_topology_put_port(port);
3237 EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
3239 int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr,
3240 struct drm_dp_mst_port *port,
3241 struct drm_dp_query_stream_enc_status_ack_reply *status)
3243 struct drm_dp_sideband_msg_tx *txmsg;
3247 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3251 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3257 get_random_bytes(nonce, sizeof(nonce));
3260 * "Source device targets the QUERY_STREAM_ENCRYPTION_STATUS message
3261 * transaction at the MST Branch device directly connected to the
3264 txmsg->dst = mgr->mst_primary;
3266 build_query_stream_enc_status(txmsg, port->vcpi.vcpi, nonce);
3268 drm_dp_queue_down_tx(mgr, txmsg);
3270 ret = drm_dp_mst_wait_tx_reply(mgr->mst_primary, txmsg);
3273 } else if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3274 drm_dbg_kms(mgr->dev, "query encryption status nak received\n");
3280 memcpy(status, &txmsg->reply.u.enc_status, sizeof(*status));
3283 drm_dp_mst_topology_put_port(port);
3288 EXPORT_SYMBOL(drm_dp_send_query_stream_enc_status);
3290 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3292 struct drm_dp_payload *payload)
3296 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
3298 payload->payload_state = 0;
3301 payload->payload_state = DP_PAYLOAD_LOCAL;
3305 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3306 struct drm_dp_mst_port *port,
3308 struct drm_dp_payload *payload)
3312 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
3315 payload->payload_state = DP_PAYLOAD_REMOTE;
3319 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3320 struct drm_dp_mst_port *port,
3322 struct drm_dp_payload *payload)
3324 drm_dbg_kms(mgr->dev, "\n");
3325 /* it's okay for these to fail */
3327 drm_dp_payload_send_msg(mgr, port, id, 0);
3330 drm_dp_dpcd_write_payload(mgr, id, payload);
3331 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
3335 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3337 struct drm_dp_payload *payload)
3339 payload->payload_state = 0;
3344 * drm_dp_update_payload_part1() - Execute payload update part 1
3345 * @mgr: manager to use.
3346 * @start_slot: this is the cur slot
3348 * NOTE: start_slot is a temporary workaround for non-atomic drivers,
3349 * this will be removed when non-atomic mst helpers are moved out of the helper
3351 * This iterates over all proposed virtual channels, and tries to
3352 * allocate space in the link for them. For 0->slots transitions,
3353 * this step just writes the VCPI to the MST device. For slots->0
3354 * transitions, this writes the updated VCPIs and removes the
3355 * remote VC payloads.
3357 * after calling this the driver should generate ACT and payload
3360 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr, int start_slot)
3362 struct drm_dp_payload req_payload;
3363 struct drm_dp_mst_port *port;
3365 int cur_slots = start_slot;
3368 mutex_lock(&mgr->payload_lock);
3369 for (i = 0; i < mgr->max_payloads; i++) {
3370 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
3371 struct drm_dp_payload *payload = &mgr->payloads[i];
3372 bool put_port = false;
3374 /* solve the current payloads - compare to the hw ones
3375 - update the hw view */
3376 req_payload.start_slot = cur_slots;
3378 port = container_of(vcpi, struct drm_dp_mst_port,
3381 mutex_lock(&mgr->lock);
3382 skip = !drm_dp_mst_port_downstream_of_branch(port, mgr->mst_primary);
3383 mutex_unlock(&mgr->lock);
3386 drm_dbg_kms(mgr->dev,
3387 "Virtual channel %d is not in current topology\n",
3391 /* Validated ports don't matter if we're releasing
3394 if (vcpi->num_slots) {
3395 port = drm_dp_mst_topology_get_port_validated(
3398 if (vcpi->num_slots == payload->num_slots) {
3399 cur_slots += vcpi->num_slots;
3400 payload->start_slot = req_payload.start_slot;
3403 drm_dbg_kms(mgr->dev,
3404 "Fail:set payload to invalid sink");
3405 mutex_unlock(&mgr->payload_lock);
3412 req_payload.num_slots = vcpi->num_slots;
3413 req_payload.vcpi = vcpi->vcpi;
3416 req_payload.num_slots = 0;
3419 payload->start_slot = req_payload.start_slot;
3420 /* work out what is required to happen with this payload */
3421 if (payload->num_slots != req_payload.num_slots) {
3423 /* need to push an update for this payload */
3424 if (req_payload.num_slots) {
3425 drm_dp_create_payload_step1(mgr, vcpi->vcpi,
3427 payload->num_slots = req_payload.num_slots;
3428 payload->vcpi = req_payload.vcpi;
3430 } else if (payload->num_slots) {
3431 payload->num_slots = 0;
3432 drm_dp_destroy_payload_step1(mgr, port,
3435 req_payload.payload_state =
3436 payload->payload_state;
3437 payload->start_slot = 0;
3439 payload->payload_state = req_payload.payload_state;
3441 cur_slots += req_payload.num_slots;
3444 drm_dp_mst_topology_put_port(port);
3447 for (i = 0; i < mgr->max_payloads; /* do nothing */) {
3448 if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL) {
3453 drm_dbg_kms(mgr->dev, "removing payload %d\n", i);
3454 for (j = i; j < mgr->max_payloads - 1; j++) {
3455 mgr->payloads[j] = mgr->payloads[j + 1];
3456 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
3458 if (mgr->proposed_vcpis[j] &&
3459 mgr->proposed_vcpis[j]->num_slots) {
3460 set_bit(j + 1, &mgr->payload_mask);
3462 clear_bit(j + 1, &mgr->payload_mask);
3466 memset(&mgr->payloads[mgr->max_payloads - 1], 0,
3467 sizeof(struct drm_dp_payload));
3468 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
3469 clear_bit(mgr->max_payloads, &mgr->payload_mask);
3471 mutex_unlock(&mgr->payload_lock);
3475 EXPORT_SYMBOL(drm_dp_update_payload_part1);
3478 * drm_dp_update_payload_part2() - Execute payload update part 2
3479 * @mgr: manager to use.
3481 * This iterates over all proposed virtual channels, and tries to
3482 * allocate space in the link for them. For 0->slots transitions,
3483 * this step writes the remote VC payload commands. For slots->0
3484 * this just resets some internal state.
3486 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
3488 struct drm_dp_mst_port *port;
3493 mutex_lock(&mgr->payload_lock);
3494 for (i = 0; i < mgr->max_payloads; i++) {
3496 if (!mgr->proposed_vcpis[i])
3499 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
3501 mutex_lock(&mgr->lock);
3502 skip = !drm_dp_mst_port_downstream_of_branch(port, mgr->mst_primary);
3503 mutex_unlock(&mgr->lock);
3508 drm_dbg_kms(mgr->dev, "payload %d %d\n", i, mgr->payloads[i].payload_state);
3509 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
3510 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3511 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
3512 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3515 mutex_unlock(&mgr->payload_lock);
3519 mutex_unlock(&mgr->payload_lock);
3522 EXPORT_SYMBOL(drm_dp_update_payload_part2);
3524 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
3525 struct drm_dp_mst_port *port,
3526 int offset, int size, u8 *bytes)
3529 struct drm_dp_sideband_msg_tx *txmsg;
3530 struct drm_dp_mst_branch *mstb;
3532 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3536 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3542 build_dpcd_read(txmsg, port->port_num, offset, size);
3543 txmsg->dst = port->parent;
3545 drm_dp_queue_down_tx(mgr, txmsg);
3547 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3551 if (txmsg->reply.reply_type == 1) {
3552 drm_dbg_kms(mgr->dev, "mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n",
3553 mstb, port->port_num, offset, size);
3558 if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) {
3563 ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes,
3565 memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret);
3570 drm_dp_mst_topology_put_mstb(mstb);
3575 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
3576 struct drm_dp_mst_port *port,
3577 int offset, int size, u8 *bytes)
3580 struct drm_dp_sideband_msg_tx *txmsg;
3581 struct drm_dp_mst_branch *mstb;
3583 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3587 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3593 build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
3596 drm_dp_queue_down_tx(mgr, txmsg);
3598 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3600 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3608 drm_dp_mst_topology_put_mstb(mstb);
3612 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
3614 struct drm_dp_sideband_msg_reply_body reply;
3616 reply.reply_type = DP_SIDEBAND_REPLY_ACK;
3617 reply.req_type = req_type;
3618 drm_dp_encode_sideband_reply(&reply, msg);
3622 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
3623 struct drm_dp_mst_branch *mstb,
3624 int req_type, bool broadcast)
3626 struct drm_dp_sideband_msg_tx *txmsg;
3628 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3633 drm_dp_encode_up_ack_reply(txmsg, req_type);
3635 mutex_lock(&mgr->qlock);
3636 /* construct a chunk from the first msg in the tx_msg queue */
3637 process_single_tx_qlock(mgr, txmsg, true);
3638 mutex_unlock(&mgr->qlock);
3645 * drm_dp_get_vc_payload_bw - get the VC payload BW for an MST link
3646 * @mgr: The &drm_dp_mst_topology_mgr to use
3647 * @link_rate: link rate in 10kbits/s units
3648 * @link_lane_count: lane count
3650 * Calculate the total bandwidth of a MultiStream Transport link. The returned
3651 * value is in units of PBNs/(timeslots/1 MTP). This value can be used to
3652 * convert the number of PBNs required for a given stream to the number of
3653 * timeslots this stream requires in each MTP.
3655 int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr,
3656 int link_rate, int link_lane_count)
3658 if (link_rate == 0 || link_lane_count == 0)
3659 drm_dbg_kms(mgr->dev, "invalid link rate/lane count: (%d / %d)\n",
3660 link_rate, link_lane_count);
3662 /* See DP v2.0 2.6.4.2, VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */
3663 return link_rate * link_lane_count / 54000;
3665 EXPORT_SYMBOL(drm_dp_get_vc_payload_bw);
3668 * drm_dp_read_mst_cap() - check whether or not a sink supports MST
3669 * @aux: The DP AUX channel to use
3670 * @dpcd: A cached copy of the DPCD capabilities for this sink
3672 * Returns: %True if the sink supports MST, %false otherwise
3674 bool drm_dp_read_mst_cap(struct drm_dp_aux *aux,
3675 const u8 dpcd[DP_RECEIVER_CAP_SIZE])
3679 if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_12)
3682 if (drm_dp_dpcd_readb(aux, DP_MSTM_CAP, &mstm_cap) != 1)
3685 return mstm_cap & DP_MST_CAP;
3687 EXPORT_SYMBOL(drm_dp_read_mst_cap);
3690 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
3691 * @mgr: manager to set state for
3692 * @mst_state: true to enable MST on this connector - false to disable.
3694 * This is called by the driver when it detects an MST capable device plugged
3695 * into a DP MST capable port, or when a DP MST capable device is unplugged.
3697 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
3700 struct drm_dp_mst_branch *mstb = NULL;
3702 mutex_lock(&mgr->payload_lock);
3703 mutex_lock(&mgr->lock);
3704 if (mst_state == mgr->mst_state)
3707 mgr->mst_state = mst_state;
3708 /* set the device into MST mode */
3710 struct drm_dp_payload reset_pay;
3714 WARN_ON(mgr->mst_primary);
3717 ret = drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd);
3719 drm_dbg_kms(mgr->dev, "%s: failed to read DPCD, ret %d\n",
3720 mgr->aux->name, ret);
3724 lane_count = min_t(int, mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK, mgr->max_lane_count);
3725 link_rate = min_t(int, drm_dp_bw_code_to_link_rate(mgr->dpcd[1]), mgr->max_link_rate);
3726 mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr,
3729 if (mgr->pbn_div == 0) {
3734 /* add initial branch device at LCT 1 */
3735 mstb = drm_dp_add_mst_branch_device(1, NULL);
3742 /* give this the main reference */
3743 mgr->mst_primary = mstb;
3744 drm_dp_mst_topology_get_mstb(mgr->mst_primary);
3746 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3749 DP_UPSTREAM_IS_SRC);
3753 reset_pay.start_slot = 0;
3754 reset_pay.num_slots = 0x3f;
3755 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
3757 queue_work(system_long_wq, &mgr->work);
3761 /* disable MST on the device */
3762 mstb = mgr->mst_primary;
3763 mgr->mst_primary = NULL;
3764 /* this can fail if the device is gone */
3765 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
3767 memset(mgr->payloads, 0,
3768 mgr->max_payloads * sizeof(mgr->payloads[0]));
3769 memset(mgr->proposed_vcpis, 0,
3770 mgr->max_payloads * sizeof(mgr->proposed_vcpis[0]));
3771 mgr->payload_mask = 0;
3772 set_bit(0, &mgr->payload_mask);
3774 mgr->payload_id_table_cleared = false;
3778 mutex_unlock(&mgr->lock);
3779 mutex_unlock(&mgr->payload_lock);
3781 drm_dp_mst_topology_put_mstb(mstb);
3785 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
3788 drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
3790 struct drm_dp_mst_port *port;
3792 /* The link address will need to be re-sent on resume */
3793 mstb->link_address_sent = false;
3795 list_for_each_entry(port, &mstb->ports, next)
3797 drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb);
3801 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
3802 * @mgr: manager to suspend
3804 * This function tells the MST device that we can't handle UP messages
3805 * anymore. This should stop it from sending any since we are suspended.
3807 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
3809 mutex_lock(&mgr->lock);
3810 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3811 DP_MST_EN | DP_UPSTREAM_IS_SRC);
3812 mutex_unlock(&mgr->lock);
3813 flush_work(&mgr->up_req_work);
3814 flush_work(&mgr->work);
3815 flush_work(&mgr->delayed_destroy_work);
3817 mutex_lock(&mgr->lock);
3818 if (mgr->mst_state && mgr->mst_primary)
3819 drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary);
3820 mutex_unlock(&mgr->lock);
3822 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
3825 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
3826 * @mgr: manager to resume
3827 * @sync: whether or not to perform topology reprobing synchronously
3829 * This will fetch DPCD and see if the device is still there,
3830 * if it is, it will rewrite the MSTM control bits, and return.
3832 * If the device fails this returns -1, and the driver should do
3833 * a full MST reprobe, in case we were undocked.
3835 * During system resume (where it is assumed that the driver will be calling
3836 * drm_atomic_helper_resume()) this function should be called beforehand with
3837 * @sync set to true. In contexts like runtime resume where the driver is not
3838 * expected to be calling drm_atomic_helper_resume(), this function should be
3839 * called with @sync set to false in order to avoid deadlocking.
3841 * Returns: -1 if the MST topology was removed while we were suspended, 0
3844 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
3850 mutex_lock(&mgr->lock);
3851 if (!mgr->mst_primary)
3854 if (drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd) < 0) {
3855 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n");
3859 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3862 DP_UPSTREAM_IS_SRC);
3864 drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n");
3868 /* Some hubs forget their guids after they resume */
3869 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
3871 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n");
3875 ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid);
3877 drm_dbg_kms(mgr->dev, "check mstb failed - undocked during suspend?\n");
3882 * For the final step of resuming the topology, we need to bring the
3883 * state of our in-memory topology back into sync with reality. So,
3884 * restart the probing process as if we're probing a new hub
3886 queue_work(system_long_wq, &mgr->work);
3887 mutex_unlock(&mgr->lock);
3890 drm_dbg_kms(mgr->dev,
3891 "Waiting for link probe work to finish re-syncing topology...\n");
3892 flush_work(&mgr->work);
3898 mutex_unlock(&mgr->lock);
3901 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
3904 drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up,
3905 struct drm_dp_mst_branch **mstb)
3909 int replylen, curreply;
3912 struct drm_dp_sideband_msg_hdr hdr;
3913 struct drm_dp_sideband_msg_rx *msg =
3914 up ? &mgr->up_req_recv : &mgr->down_rep_recv;
3915 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE :
3916 DP_SIDEBAND_MSG_DOWN_REP_BASE;
3921 len = min(mgr->max_dpcd_transaction_bytes, 16);
3922 ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len);
3924 drm_dbg_kms(mgr->dev, "failed to read DPCD down rep %d %d\n", len, ret);
3928 ret = drm_dp_decode_sideband_msg_hdr(mgr, &hdr, replyblock, len, &hdrlen);
3930 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16,
3931 1, replyblock, len, false);
3932 drm_dbg_kms(mgr->dev, "ERROR: failed header\n");
3937 /* Caller is responsible for giving back this reference */
3938 *mstb = drm_dp_get_mst_branch_device(mgr, hdr.lct, hdr.rad);
3940 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr.lct);
3945 if (!drm_dp_sideband_msg_set_header(msg, &hdr, hdrlen)) {
3946 drm_dbg_kms(mgr->dev, "sideband msg set header failed %d\n", replyblock[0]);
3950 replylen = min(msg->curchunk_len, (u8)(len - hdrlen));
3951 ret = drm_dp_sideband_append_payload(msg, replyblock + hdrlen, replylen);
3953 drm_dbg_kms(mgr->dev, "sideband msg build failed %d\n", replyblock[0]);
3957 replylen = msg->curchunk_len + msg->curchunk_hdrlen - len;
3959 while (replylen > 0) {
3960 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
3961 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
3964 drm_dbg_kms(mgr->dev, "failed to read a chunk (len %d, ret %d)\n",
3969 ret = drm_dp_sideband_append_payload(msg, replyblock, len);
3971 drm_dbg_kms(mgr->dev, "failed to build sideband msg\n");
3981 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
3983 struct drm_dp_sideband_msg_tx *txmsg;
3984 struct drm_dp_mst_branch *mstb = NULL;
3985 struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv;
3987 if (!drm_dp_get_one_sb_msg(mgr, false, &mstb))
3990 /* Multi-packet message transmission, don't clear the reply */
3991 if (!msg->have_eomt)
3994 /* find the message */
3995 mutex_lock(&mgr->qlock);
3996 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq,
3997 struct drm_dp_sideband_msg_tx, next);
3998 mutex_unlock(&mgr->qlock);
4000 /* Were we actually expecting a response, and from this mstb? */
4001 if (!txmsg || txmsg->dst != mstb) {
4002 struct drm_dp_sideband_msg_hdr *hdr;
4004 hdr = &msg->initial_hdr;
4005 drm_dbg_kms(mgr->dev, "Got MST reply with no msg %p %d %d %02x %02x\n",
4006 mstb, hdr->seqno, hdr->lct, hdr->rad[0], msg->msg[0]);
4007 goto out_clear_reply;
4010 drm_dp_sideband_parse_reply(mgr, msg, &txmsg->reply);
4012 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
4013 drm_dbg_kms(mgr->dev,
4014 "Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
4015 txmsg->reply.req_type,
4016 drm_dp_mst_req_type_str(txmsg->reply.req_type),
4017 txmsg->reply.u.nak.reason,
4018 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason),
4019 txmsg->reply.u.nak.nak_data);
4022 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
4023 drm_dp_mst_topology_put_mstb(mstb);
4025 mutex_lock(&mgr->qlock);
4026 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
4027 list_del(&txmsg->next);
4028 mutex_unlock(&mgr->qlock);
4030 wake_up_all(&mgr->tx_waitq);
4035 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
4038 drm_dp_mst_topology_put_mstb(mstb);
4044 drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
4045 struct drm_dp_pending_up_req *up_req)
4047 struct drm_dp_mst_branch *mstb = NULL;
4048 struct drm_dp_sideband_msg_req_body *msg = &up_req->msg;
4049 struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr;
4050 bool hotplug = false;
4052 if (hdr->broadcast) {
4053 const u8 *guid = NULL;
4055 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY)
4056 guid = msg->u.conn_stat.guid;
4057 else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
4058 guid = msg->u.resource_stat.guid;
4061 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
4063 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
4067 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr->lct);
4071 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */
4072 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) {
4073 drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat);
4077 drm_dp_mst_topology_put_mstb(mstb);
4081 static void drm_dp_mst_up_req_work(struct work_struct *work)
4083 struct drm_dp_mst_topology_mgr *mgr =
4084 container_of(work, struct drm_dp_mst_topology_mgr,
4086 struct drm_dp_pending_up_req *up_req;
4087 bool send_hotplug = false;
4089 mutex_lock(&mgr->probe_lock);
4091 mutex_lock(&mgr->up_req_lock);
4092 up_req = list_first_entry_or_null(&mgr->up_req_list,
4093 struct drm_dp_pending_up_req,
4096 list_del(&up_req->next);
4097 mutex_unlock(&mgr->up_req_lock);
4102 send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req);
4105 mutex_unlock(&mgr->probe_lock);
4108 drm_kms_helper_hotplug_event(mgr->dev);
4111 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
4113 struct drm_dp_pending_up_req *up_req;
4115 if (!drm_dp_get_one_sb_msg(mgr, true, NULL))
4118 if (!mgr->up_req_recv.have_eomt)
4121 up_req = kzalloc(sizeof(*up_req), GFP_KERNEL);
4125 INIT_LIST_HEAD(&up_req->next);
4127 drm_dp_sideband_parse_req(mgr, &mgr->up_req_recv, &up_req->msg);
4129 if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY &&
4130 up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) {
4131 drm_dbg_kms(mgr->dev, "Received unknown up req type, ignoring: %x\n",
4132 up_req->msg.req_type);
4137 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type,
4140 if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
4141 const struct drm_dp_connection_status_notify *conn_stat =
4142 &up_req->msg.u.conn_stat;
4144 drm_dbg_kms(mgr->dev, "Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
4145 conn_stat->port_number,
4146 conn_stat->legacy_device_plug_status,
4147 conn_stat->displayport_device_plug_status,
4148 conn_stat->message_capability_status,
4149 conn_stat->input_port,
4150 conn_stat->peer_device_type);
4151 } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
4152 const struct drm_dp_resource_status_notify *res_stat =
4153 &up_req->msg.u.resource_stat;
4155 drm_dbg_kms(mgr->dev, "Got RSN: pn: %d avail_pbn %d\n",
4156 res_stat->port_number,
4157 res_stat->available_pbn);
4160 up_req->hdr = mgr->up_req_recv.initial_hdr;
4161 mutex_lock(&mgr->up_req_lock);
4162 list_add_tail(&up_req->next, &mgr->up_req_list);
4163 mutex_unlock(&mgr->up_req_lock);
4164 queue_work(system_long_wq, &mgr->up_req_work);
4167 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
4172 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
4173 * @mgr: manager to notify irq for.
4174 * @esi: 4 bytes from SINK_COUNT_ESI
4175 * @handled: whether the hpd interrupt was consumed or not
4177 * This should be called from the driver when it detects a short IRQ,
4178 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
4179 * topology manager will process the sideband messages received as a result
4182 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
4187 sc = DP_GET_SINK_COUNT(esi[0]);
4189 if (sc != mgr->sink_count) {
4190 mgr->sink_count = sc;
4194 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
4195 ret = drm_dp_mst_handle_down_rep(mgr);
4199 if (esi[1] & DP_UP_REQ_MSG_RDY) {
4200 ret |= drm_dp_mst_handle_up_req(mgr);
4204 drm_dp_mst_kick_tx(mgr);
4207 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
4210 * drm_dp_mst_detect_port() - get connection status for an MST port
4211 * @connector: DRM connector for this port
4212 * @ctx: The acquisition context to use for grabbing locks
4213 * @mgr: manager for this port
4214 * @port: pointer to a port
4216 * This returns the current connection state for a port.
4219 drm_dp_mst_detect_port(struct drm_connector *connector,
4220 struct drm_modeset_acquire_ctx *ctx,
4221 struct drm_dp_mst_topology_mgr *mgr,
4222 struct drm_dp_mst_port *port)
4226 /* we need to search for the port in the mgr in case it's gone */
4227 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4229 return connector_status_disconnected;
4231 ret = drm_modeset_lock(&mgr->base.lock, ctx);
4235 ret = connector_status_disconnected;
4240 switch (port->pdt) {
4241 case DP_PEER_DEVICE_NONE:
4243 case DP_PEER_DEVICE_MST_BRANCHING:
4245 ret = connector_status_connected;
4248 case DP_PEER_DEVICE_SST_SINK:
4249 ret = connector_status_connected;
4250 /* for logical ports - cache the EDID */
4251 if (port->port_num >= DP_MST_LOGICAL_PORT_0 && !port->cached_edid)
4252 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
4254 case DP_PEER_DEVICE_DP_LEGACY_CONV:
4256 ret = connector_status_connected;
4260 drm_dp_mst_topology_put_port(port);
4263 EXPORT_SYMBOL(drm_dp_mst_detect_port);
4266 * drm_dp_mst_get_edid() - get EDID for an MST port
4267 * @connector: toplevel connector to get EDID for
4268 * @mgr: manager for this port
4269 * @port: unverified pointer to a port.
4271 * This returns an EDID for the port connected to a connector,
4272 * It validates the pointer still exists so the caller doesn't require a
4275 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4277 struct edid *edid = NULL;
4279 /* we need to search for the port in the mgr in case it's gone */
4280 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4284 if (port->cached_edid)
4285 edid = drm_edid_duplicate(port->cached_edid);
4287 edid = drm_get_edid(connector, &port->aux.ddc);
4289 port->has_audio = drm_detect_monitor_audio(edid);
4290 drm_dp_mst_topology_put_port(port);
4293 EXPORT_SYMBOL(drm_dp_mst_get_edid);
4296 * drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
4297 * @mgr: manager to use
4298 * @pbn: payload bandwidth to convert into slots.
4300 * Calculate the number of VCPI slots that will be required for the given PBN
4301 * value. This function is deprecated, and should not be used in atomic
4305 * The total slots required for this port, or error.
4307 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
4312 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
4314 /* max. time slots - one slot for MTP header */
4319 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
4321 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4322 struct drm_dp_vcpi *vcpi, int pbn, int slots)
4327 vcpi->aligned_pbn = slots * mgr->pbn_div;
4328 vcpi->num_slots = slots;
4330 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
4337 * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
4338 * @state: global atomic state
4339 * @mgr: MST topology manager for the port
4340 * @port: port to find vcpi slots for
4341 * @pbn: bandwidth required for the mode in PBN
4342 * @pbn_div: divider for DSC mode that takes FEC into account
4344 * Allocates VCPI slots to @port, replacing any previous VCPI allocations it
4345 * may have had. Any atomic drivers which support MST must call this function
4346 * in their &drm_encoder_helper_funcs.atomic_check() callback to change the
4347 * current VCPI allocation for the new state, but only when
4348 * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set
4349 * to ensure compatibility with userspace applications that still use the
4350 * legacy modesetting UAPI.
4352 * Allocations set by this function are not checked against the bandwidth
4353 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
4355 * Additionally, it is OK to call this function multiple times on the same
4356 * @port as needed. It is not OK however, to call this function and
4357 * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
4360 * drm_dp_atomic_release_vcpi_slots()
4361 * drm_dp_mst_atomic_check()
4364 * Total slots in the atomic state assigned for this port, or a negative error
4365 * code if the port no longer exists
4367 int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
4368 struct drm_dp_mst_topology_mgr *mgr,
4369 struct drm_dp_mst_port *port, int pbn,
4372 struct drm_dp_mst_topology_state *topology_state;
4373 struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
4374 int prev_slots, prev_bw, req_slots;
4376 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4377 if (IS_ERR(topology_state))
4378 return PTR_ERR(topology_state);
4380 /* Find the current allocation for this port, if any */
4381 list_for_each_entry(pos, &topology_state->vcpis, next) {
4382 if (pos->port == port) {
4384 prev_slots = vcpi->vcpi;
4385 prev_bw = vcpi->pbn;
4388 * This should never happen, unless the driver tries
4389 * releasing and allocating the same VCPI allocation,
4392 if (WARN_ON(!prev_slots)) {
4394 "cannot allocate and release VCPI on [MST PORT:%p] in the same state\n",
4408 pbn_div = mgr->pbn_div;
4410 req_slots = DIV_ROUND_UP(pbn, pbn_div);
4412 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
4413 port->connector->base.id, port->connector->name,
4414 port, prev_slots, req_slots);
4415 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n",
4416 port->connector->base.id, port->connector->name,
4417 port, prev_bw, pbn);
4419 /* Add the new allocation to the state */
4421 vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL);
4425 drm_dp_mst_get_port_malloc(port);
4427 list_add(&vcpi->next, &topology_state->vcpis);
4429 vcpi->vcpi = req_slots;
4434 EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
4437 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
4438 * @state: global atomic state
4439 * @mgr: MST topology manager for the port
4440 * @port: The port to release the VCPI slots from
4442 * Releases any VCPI slots that have been allocated to a port in the atomic
4443 * state. Any atomic drivers which support MST must call this function in
4444 * their &drm_connector_helper_funcs.atomic_check() callback when the
4445 * connector will no longer have VCPI allocated (e.g. because its CRTC was
4446 * removed) when it had VCPI allocated in the previous atomic state.
4448 * It is OK to call this even if @port has been removed from the system.
4449 * Additionally, it is OK to call this function multiple times on the same
4450 * @port as needed. It is not OK however, to call this function and
4451 * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
4455 * drm_dp_atomic_find_vcpi_slots()
4456 * drm_dp_mst_atomic_check()
4459 * 0 if all slots for this port were added back to
4460 * &drm_dp_mst_topology_state.avail_slots or negative error code
4462 int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
4463 struct drm_dp_mst_topology_mgr *mgr,
4464 struct drm_dp_mst_port *port)
4466 struct drm_dp_mst_topology_state *topology_state;
4467 struct drm_dp_vcpi_allocation *pos;
4470 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4471 if (IS_ERR(topology_state))
4472 return PTR_ERR(topology_state);
4474 list_for_each_entry(pos, &topology_state->vcpis, next) {
4475 if (pos->port == port) {
4480 if (WARN_ON(!found)) {
4481 drm_err(mgr->dev, "no VCPI for [MST PORT:%p] found in mst state %p\n",
4482 port, &topology_state->base);
4486 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi);
4488 drm_dp_mst_put_port_malloc(port);
4495 EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
4498 * drm_dp_mst_update_slots() - updates the slot info depending on the DP ecoding format
4499 * @mst_state: mst_state to update
4500 * @link_encoding_cap: the ecoding format on the link
4502 void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap)
4504 if (link_encoding_cap == DP_CAP_ANSI_128B132B) {
4505 mst_state->total_avail_slots = 64;
4506 mst_state->start_slot = 0;
4508 mst_state->total_avail_slots = 63;
4509 mst_state->start_slot = 1;
4512 DRM_DEBUG_KMS("%s encoding format on mst_state 0x%p\n",
4513 (link_encoding_cap == DP_CAP_ANSI_128B132B) ? "128b/132b":"8b/10b",
4516 EXPORT_SYMBOL(drm_dp_mst_update_slots);
4519 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
4520 * @mgr: manager for this port
4521 * @port: port to allocate a virtual channel for.
4522 * @pbn: payload bandwidth number to request
4523 * @slots: returned number of slots for this PBN.
4525 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4526 struct drm_dp_mst_port *port, int pbn, int slots)
4533 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4537 if (port->vcpi.vcpi > 0) {
4538 drm_dbg_kms(mgr->dev,
4539 "payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
4540 port->vcpi.vcpi, port->vcpi.pbn, pbn);
4541 if (pbn == port->vcpi.pbn) {
4542 drm_dp_mst_topology_put_port(port);
4547 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
4549 drm_dbg_kms(mgr->dev, "failed to init vcpi slots=%d ret=%d\n",
4550 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
4551 drm_dp_mst_topology_put_port(port);
4554 drm_dbg_kms(mgr->dev, "initing vcpi for pbn=%d slots=%d\n", pbn, port->vcpi.num_slots);
4556 /* Keep port allocated until its payload has been removed */
4557 drm_dp_mst_get_port_malloc(port);
4558 drm_dp_mst_topology_put_port(port);
4563 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
4565 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4569 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4573 slots = port->vcpi.num_slots;
4574 drm_dp_mst_topology_put_port(port);
4577 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
4580 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
4581 * @mgr: manager for this port
4582 * @port: unverified pointer to a port.
4584 * This just resets the number of slots for the ports VCPI for later programming.
4586 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4589 * A port with VCPI will remain allocated until its VCPI is
4590 * released, no verified ref needed
4593 port->vcpi.num_slots = 0;
4595 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
4598 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
4599 * @mgr: manager for this port
4600 * @port: port to deallocate vcpi for
4602 * This can be called unconditionally, regardless of whether
4603 * drm_dp_mst_allocate_vcpi() succeeded or not.
4605 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4606 struct drm_dp_mst_port *port)
4610 if (!port->vcpi.vcpi)
4613 mutex_lock(&mgr->lock);
4614 skip = !drm_dp_mst_port_downstream_of_branch(port, mgr->mst_primary);
4615 mutex_unlock(&mgr->lock);
4620 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
4621 port->vcpi.num_slots = 0;
4623 port->vcpi.aligned_pbn = 0;
4624 port->vcpi.vcpi = 0;
4625 drm_dp_mst_put_port_malloc(port);
4627 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
4629 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
4630 int id, struct drm_dp_payload *payload)
4632 u8 payload_alloc[3], status;
4636 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
4637 DP_PAYLOAD_TABLE_UPDATED);
4639 payload_alloc[0] = id;
4640 payload_alloc[1] = payload->start_slot;
4641 payload_alloc[2] = payload->num_slots;
4643 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
4645 drm_dbg_kms(mgr->dev, "failed to write payload allocation %d\n", ret);
4650 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4652 drm_dbg_kms(mgr->dev, "failed to read payload table status %d\n", ret);
4656 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
4659 usleep_range(10000, 20000);
4662 drm_dbg_kms(mgr->dev, "status not set after read payload table status %d\n",
4672 static int do_get_act_status(struct drm_dp_aux *aux)
4677 ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4685 * drm_dp_check_act_status() - Polls for ACT handled status.
4686 * @mgr: manager to use
4688 * Tries waiting for the MST hub to finish updating it's payload table by
4689 * polling for the ACT handled bit for up to 3 seconds (yes-some hubs really
4693 * 0 if the ACT was handled in time, negative error code on failure.
4695 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
4698 * There doesn't seem to be any recommended retry count or timeout in
4699 * the MST specification. Since some hubs have been observed to take
4700 * over 1 second to update their payload allocations under certain
4701 * conditions, we use a rather large timeout value.
4703 const int timeout_ms = 3000;
4706 ret = readx_poll_timeout(do_get_act_status, mgr->aux, status,
4707 status & DP_PAYLOAD_ACT_HANDLED || status < 0,
4708 200, timeout_ms * USEC_PER_MSEC);
4709 if (ret < 0 && status >= 0) {
4710 drm_err(mgr->dev, "Failed to get ACT after %dms, last status: %02x\n",
4711 timeout_ms, status);
4713 } else if (status < 0) {
4715 * Failure here isn't unexpected - the hub may have
4716 * just been unplugged
4718 drm_dbg_kms(mgr->dev, "Failed to read payload table status: %d\n", status);
4724 EXPORT_SYMBOL(drm_dp_check_act_status);
4727 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
4728 * @clock: dot clock for the mode
4729 * @bpp: bpp for the mode.
4730 * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel
4732 * This uses the formula in the spec to calculate the PBN value for a mode.
4734 int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc)
4737 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
4738 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
4739 * common multiplier to render an integer PBN for all link rate/lane
4740 * counts combinations
4742 * peak_kbps *= (1006/1000)
4743 * peak_kbps *= (64/54)
4744 * peak_kbps *= 8 convert to bytes
4746 * If the bpp is in units of 1/16, further divide by 16. Put this
4747 * factor in the numerator rather than the denominator to avoid
4752 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006),
4753 8 * 54 * 1000 * 1000);
4755 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
4756 8 * 54 * 1000 * 1000);
4758 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
4760 /* we want to kick the TX after we've ack the up/down IRQs. */
4761 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
4763 queue_work(system_long_wq, &mgr->tx_work);
4767 * Helper function for parsing DP device types into convenient strings
4768 * for use with dp_mst_topology
4770 static const char *pdt_to_string(u8 pdt)
4773 case DP_PEER_DEVICE_NONE:
4775 case DP_PEER_DEVICE_SOURCE_OR_SST:
4776 return "SOURCE OR SST";
4777 case DP_PEER_DEVICE_MST_BRANCHING:
4778 return "MST BRANCHING";
4779 case DP_PEER_DEVICE_SST_SINK:
4781 case DP_PEER_DEVICE_DP_LEGACY_CONV:
4782 return "DP LEGACY CONV";
4788 static void drm_dp_mst_dump_mstb(struct seq_file *m,
4789 struct drm_dp_mst_branch *mstb)
4791 struct drm_dp_mst_port *port;
4792 int tabs = mstb->lct;
4796 for (i = 0; i < tabs; i++)
4800 seq_printf(m, "%smstb - [%p]: num_ports: %d\n", prefix, mstb, mstb->num_ports);
4801 list_for_each_entry(port, &mstb->ports, next) {
4802 seq_printf(m, "%sport %d - [%p] (%s - %s): ddps: %d, ldps: %d, sdp: %d/%d, fec: %s, conn: %p\n",
4806 port->input ? "input" : "output",
4807 pdt_to_string(port->pdt),
4810 port->num_sdp_streams,
4811 port->num_sdp_stream_sinks,
4812 port->fec_capable ? "true" : "false",
4815 drm_dp_mst_dump_mstb(m, port->mstb);
4819 #define DP_PAYLOAD_TABLE_SIZE 64
4821 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
4826 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
4827 if (drm_dp_dpcd_read(mgr->aux,
4828 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
4835 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
4836 struct drm_dp_mst_port *port, char *name,
4839 struct edid *mst_edid;
4841 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
4842 drm_edid_get_monitor_name(mst_edid, name, namelen);
4847 * drm_dp_mst_dump_topology(): dump topology to seq file.
4848 * @m: seq_file to dump output to
4849 * @mgr: manager to dump current topology for.
4851 * helper to dump MST topology to a seq file for debugfs.
4853 void drm_dp_mst_dump_topology(struct seq_file *m,
4854 struct drm_dp_mst_topology_mgr *mgr)
4857 struct drm_dp_mst_port *port;
4859 mutex_lock(&mgr->lock);
4860 if (mgr->mst_primary)
4861 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
4864 mutex_unlock(&mgr->lock);
4866 mutex_lock(&mgr->payload_lock);
4867 seq_printf(m, "\n*** VCPI Info ***\n");
4868 seq_printf(m, "payload_mask: %lx, vcpi_mask: %lx, max_payloads: %d\n", mgr->payload_mask, mgr->vcpi_mask, mgr->max_payloads);
4870 seq_printf(m, "\n| idx | port # | vcp_id | # slots | sink name |\n");
4871 for (i = 0; i < mgr->max_payloads; i++) {
4872 if (mgr->proposed_vcpis[i]) {
4875 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
4876 fetch_monitor_name(mgr, port, name, sizeof(name));
4877 seq_printf(m, "%10d%10d%10d%10d%20s\n",
4881 port->vcpi.num_slots,
4882 (*name != 0) ? name : "Unknown");
4884 seq_printf(m, "%6d - Unused\n", i);
4886 seq_printf(m, "\n*** Payload Info ***\n");
4887 seq_printf(m, "| idx | state | start slot | # slots |\n");
4888 for (i = 0; i < mgr->max_payloads; i++) {
4889 seq_printf(m, "%10d%10d%15d%10d\n",
4891 mgr->payloads[i].payload_state,
4892 mgr->payloads[i].start_slot,
4893 mgr->payloads[i].num_slots);
4895 mutex_unlock(&mgr->payload_lock);
4897 seq_printf(m, "\n*** DPCD Info ***\n");
4898 mutex_lock(&mgr->lock);
4899 if (mgr->mst_primary) {
4900 u8 buf[DP_PAYLOAD_TABLE_SIZE];
4903 if (drm_dp_read_dpcd_caps(mgr->aux, buf) < 0) {
4904 seq_printf(m, "dpcd read failed\n");
4907 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
4909 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
4911 seq_printf(m, "faux/mst read failed\n");
4914 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
4916 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
4918 seq_printf(m, "mst ctrl read failed\n");
4921 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
4923 /* dump the standard OUI branch header */
4924 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
4926 seq_printf(m, "branch oui read failed\n");
4929 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
4931 for (i = 0x3; i < 0x8 && buf[i]; i++)
4932 seq_printf(m, "%c", buf[i]);
4933 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
4934 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
4935 if (dump_dp_payload_table(mgr, buf))
4936 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
4940 mutex_unlock(&mgr->lock);
4943 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
4945 static void drm_dp_tx_work(struct work_struct *work)
4947 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
4949 mutex_lock(&mgr->qlock);
4950 if (!list_empty(&mgr->tx_msg_downq))
4951 process_single_down_tx_qlock(mgr);
4952 mutex_unlock(&mgr->qlock);
4956 drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port)
4958 drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs);
4960 if (port->connector) {
4961 drm_connector_unregister(port->connector);
4962 drm_connector_put(port->connector);
4965 drm_dp_mst_put_port_malloc(port);
4969 drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb)
4971 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
4972 struct drm_dp_mst_port *port, *port_tmp;
4973 struct drm_dp_sideband_msg_tx *txmsg, *txmsg_tmp;
4974 bool wake_tx = false;
4976 mutex_lock(&mgr->lock);
4977 list_for_each_entry_safe(port, port_tmp, &mstb->ports, next) {
4978 list_del(&port->next);
4979 drm_dp_mst_topology_put_port(port);
4981 mutex_unlock(&mgr->lock);
4983 /* drop any tx slot msg */
4984 mutex_lock(&mstb->mgr->qlock);
4985 list_for_each_entry_safe(txmsg, txmsg_tmp, &mgr->tx_msg_downq, next) {
4986 if (txmsg->dst != mstb)
4989 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
4990 list_del(&txmsg->next);
4993 mutex_unlock(&mstb->mgr->qlock);
4996 wake_up_all(&mstb->mgr->tx_waitq);
4998 drm_dp_mst_put_mstb_malloc(mstb);
5001 static void drm_dp_delayed_destroy_work(struct work_struct *work)
5003 struct drm_dp_mst_topology_mgr *mgr =
5004 container_of(work, struct drm_dp_mst_topology_mgr,
5005 delayed_destroy_work);
5006 bool send_hotplug = false, go_again;
5009 * Not a regular list traverse as we have to drop the destroy
5010 * connector lock before destroying the mstb/port, to avoid AB->BA
5011 * ordering between this lock and the config mutex.
5017 struct drm_dp_mst_branch *mstb;
5019 mutex_lock(&mgr->delayed_destroy_lock);
5020 mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list,
5021 struct drm_dp_mst_branch,
5024 list_del(&mstb->destroy_next);
5025 mutex_unlock(&mgr->delayed_destroy_lock);
5030 drm_dp_delayed_destroy_mstb(mstb);
5035 struct drm_dp_mst_port *port;
5037 mutex_lock(&mgr->delayed_destroy_lock);
5038 port = list_first_entry_or_null(&mgr->destroy_port_list,
5039 struct drm_dp_mst_port,
5042 list_del(&port->next);
5043 mutex_unlock(&mgr->delayed_destroy_lock);
5048 drm_dp_delayed_destroy_port(port);
5049 send_hotplug = true;
5055 drm_kms_helper_hotplug_event(mgr->dev);
5058 static struct drm_private_state *
5059 drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
5061 struct drm_dp_mst_topology_state *state, *old_state =
5062 to_dp_mst_topology_state(obj->state);
5063 struct drm_dp_vcpi_allocation *pos, *vcpi;
5065 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
5069 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
5071 INIT_LIST_HEAD(&state->vcpis);
5073 list_for_each_entry(pos, &old_state->vcpis, next) {
5074 /* Prune leftover freed VCPI allocations */
5078 vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL);
5082 drm_dp_mst_get_port_malloc(vcpi->port);
5083 list_add(&vcpi->next, &state->vcpis);
5086 return &state->base;
5089 list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) {
5090 drm_dp_mst_put_port_malloc(pos->port);
5098 static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
5099 struct drm_private_state *state)
5101 struct drm_dp_mst_topology_state *mst_state =
5102 to_dp_mst_topology_state(state);
5103 struct drm_dp_vcpi_allocation *pos, *tmp;
5105 list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) {
5106 /* We only keep references to ports with non-zero VCPIs */
5108 drm_dp_mst_put_port_malloc(pos->port);
5115 static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
5116 struct drm_dp_mst_branch *branch)
5118 while (port->parent) {
5119 if (port->parent == branch)
5122 if (port->parent->port_parent)
5123 port = port->parent->port_parent;
5131 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
5132 struct drm_dp_mst_topology_state *state);
5135 drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb,
5136 struct drm_dp_mst_topology_state *state)
5138 struct drm_dp_vcpi_allocation *vcpi;
5139 struct drm_dp_mst_port *port;
5140 int pbn_used = 0, ret;
5143 /* Check that we have at least one port in our state that's downstream
5144 * of this branch, otherwise we can skip this branch
5146 list_for_each_entry(vcpi, &state->vcpis, next) {
5148 !drm_dp_mst_port_downstream_of_branch(vcpi->port, mstb))
5157 if (mstb->port_parent)
5158 drm_dbg_atomic(mstb->mgr->dev,
5159 "[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n",
5160 mstb->port_parent->parent, mstb->port_parent, mstb);
5162 drm_dbg_atomic(mstb->mgr->dev, "[MSTB:%p] Checking bandwidth limits\n", mstb);
5164 list_for_each_entry(port, &mstb->ports, next) {
5165 ret = drm_dp_mst_atomic_check_port_bw_limit(port, state);
5176 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
5177 struct drm_dp_mst_topology_state *state)
5179 struct drm_dp_vcpi_allocation *vcpi;
5182 if (port->pdt == DP_PEER_DEVICE_NONE)
5185 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
5188 list_for_each_entry(vcpi, &state->vcpis, next) {
5189 if (vcpi->port != port)
5201 * This could happen if the sink deasserted its HPD line, but
5202 * the branch device still reports it as attached (PDT != NONE).
5204 if (!port->full_pbn) {
5205 drm_dbg_atomic(port->mgr->dev,
5206 "[MSTB:%p] [MST PORT:%p] no BW available for the port\n",
5207 port->parent, port);
5211 pbn_used = vcpi->pbn;
5213 pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb,
5219 if (pbn_used > port->full_pbn) {
5220 drm_dbg_atomic(port->mgr->dev,
5221 "[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n",
5222 port->parent, port, pbn_used, port->full_pbn);
5226 drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n",
5227 port->parent, port, pbn_used, port->full_pbn);
5233 drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr,
5234 struct drm_dp_mst_topology_state *mst_state)
5236 struct drm_dp_vcpi_allocation *vcpi;
5237 int avail_slots = mst_state->total_avail_slots, payload_count = 0;
5239 list_for_each_entry(vcpi, &mst_state->vcpis, next) {
5240 /* Releasing VCPI is always OK-even if the port is gone */
5242 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] releases all VCPI slots\n",
5247 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] requires %d vcpi slots\n",
5248 vcpi->port, vcpi->vcpi);
5250 avail_slots -= vcpi->vcpi;
5251 if (avail_slots < 0) {
5252 drm_dbg_atomic(mgr->dev,
5253 "[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n",
5254 vcpi->port, mst_state, avail_slots + vcpi->vcpi);
5258 if (++payload_count > mgr->max_payloads) {
5259 drm_dbg_atomic(mgr->dev,
5260 "[MST MGR:%p] state %p has too many payloads (max=%d)\n",
5261 mgr, mst_state, mgr->max_payloads);
5265 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
5266 mgr, mst_state, avail_slots, mst_state->total_avail_slots - avail_slots);
5272 * drm_dp_mst_add_affected_dsc_crtcs
5273 * @state: Pointer to the new struct drm_dp_mst_topology_state
5274 * @mgr: MST topology manager
5276 * Whenever there is a change in mst topology
5277 * DSC configuration would have to be recalculated
5278 * therefore we need to trigger modeset on all affected
5279 * CRTCs in that topology
5282 * drm_dp_mst_atomic_enable_dsc()
5284 int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr)
5286 struct drm_dp_mst_topology_state *mst_state;
5287 struct drm_dp_vcpi_allocation *pos;
5288 struct drm_connector *connector;
5289 struct drm_connector_state *conn_state;
5290 struct drm_crtc *crtc;
5291 struct drm_crtc_state *crtc_state;
5293 mst_state = drm_atomic_get_mst_topology_state(state, mgr);
5295 if (IS_ERR(mst_state))
5298 list_for_each_entry(pos, &mst_state->vcpis, next) {
5300 connector = pos->port->connector;
5305 conn_state = drm_atomic_get_connector_state(state, connector);
5307 if (IS_ERR(conn_state))
5308 return PTR_ERR(conn_state);
5310 crtc = conn_state->crtc;
5315 if (!drm_dp_mst_dsc_aux_for_port(pos->port))
5318 crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc);
5320 if (IS_ERR(crtc_state))
5321 return PTR_ERR(crtc_state);
5323 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] Setting mode_changed flag on CRTC %p\n",
5326 crtc_state->mode_changed = true;
5330 EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs);
5333 * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off
5334 * @state: Pointer to the new drm_atomic_state
5335 * @port: Pointer to the affected MST Port
5336 * @pbn: Newly recalculated bw required for link with DSC enabled
5337 * @pbn_div: Divider to calculate correct number of pbn per slot
5338 * @enable: Boolean flag to enable or disable DSC on the port
5340 * This function enables DSC on the given Port
5341 * by recalculating its vcpi from pbn provided
5342 * and sets dsc_enable flag to keep track of which
5343 * ports have DSC enabled
5346 int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
5347 struct drm_dp_mst_port *port,
5348 int pbn, int pbn_div,
5351 struct drm_dp_mst_topology_state *mst_state;
5352 struct drm_dp_vcpi_allocation *pos;
5356 mst_state = drm_atomic_get_mst_topology_state(state, port->mgr);
5358 if (IS_ERR(mst_state))
5359 return PTR_ERR(mst_state);
5361 list_for_each_entry(pos, &mst_state->vcpis, next) {
5362 if (pos->port == port) {
5369 drm_dbg_atomic(state->dev,
5370 "[MST PORT:%p] Couldn't find VCPI allocation in mst state %p\n",
5375 if (pos->dsc_enabled == enable) {
5376 drm_dbg_atomic(state->dev,
5377 "[MST PORT:%p] DSC flag is already set to %d, returning %d VCPI slots\n",
5378 port, enable, pos->vcpi);
5383 vcpi = drm_dp_atomic_find_vcpi_slots(state, port->mgr, port, pbn, pbn_div);
5384 drm_dbg_atomic(state->dev,
5385 "[MST PORT:%p] Enabling DSC flag, reallocating %d VCPI slots on the port\n",
5391 pos->dsc_enabled = enable;
5395 EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc);
5397 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
5398 * atomic update is valid
5399 * @state: Pointer to the new &struct drm_dp_mst_topology_state
5401 * Checks the given topology state for an atomic update to ensure that it's
5402 * valid. This includes checking whether there's enough bandwidth to support
5403 * the new VCPI allocations in the atomic update.
5405 * Any atomic drivers supporting DP MST must make sure to call this after
5406 * checking the rest of their state in their
5407 * &drm_mode_config_funcs.atomic_check() callback.
5410 * drm_dp_atomic_find_vcpi_slots()
5411 * drm_dp_atomic_release_vcpi_slots()
5415 * 0 if the new state is valid, negative error code otherwise.
5417 int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
5419 struct drm_dp_mst_topology_mgr *mgr;
5420 struct drm_dp_mst_topology_state *mst_state;
5423 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
5424 if (!mgr->mst_state)
5427 ret = drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr, mst_state);
5431 mutex_lock(&mgr->lock);
5432 ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary,
5434 mutex_unlock(&mgr->lock);
5443 EXPORT_SYMBOL(drm_dp_mst_atomic_check);
5445 const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
5446 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
5447 .atomic_destroy_state = drm_dp_mst_destroy_state,
5449 EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
5452 * drm_atomic_get_mst_topology_state: get MST topology state
5454 * @state: global atomic state
5455 * @mgr: MST topology manager, also the private object in this case
5457 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
5458 * state vtable so that the private object state returned is that of a MST
5459 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
5460 * to care of the locking, so warn if don't hold the connection_mutex.
5464 * The MST topology state or error pointer.
5466 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
5467 struct drm_dp_mst_topology_mgr *mgr)
5469 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
5471 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
5474 * drm_dp_mst_topology_mgr_init - initialise a topology manager
5475 * @mgr: manager struct to initialise
5476 * @dev: device providing this structure - for i2c addition.
5477 * @aux: DP helper aux channel to talk to this device
5478 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
5479 * @max_payloads: maximum number of payloads this GPU can source
5480 * @max_lane_count: maximum number of lanes this GPU supports
5481 * @max_link_rate: maximum link rate per lane this GPU supports in kHz
5482 * @conn_base_id: the connector object ID the MST device is connected to.
5484 * Return 0 for success, or negative error code on failure
5486 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
5487 struct drm_device *dev, struct drm_dp_aux *aux,
5488 int max_dpcd_transaction_bytes, int max_payloads,
5489 int max_lane_count, int max_link_rate,
5492 struct drm_dp_mst_topology_state *mst_state;
5494 mutex_init(&mgr->lock);
5495 mutex_init(&mgr->qlock);
5496 mutex_init(&mgr->payload_lock);
5497 mutex_init(&mgr->delayed_destroy_lock);
5498 mutex_init(&mgr->up_req_lock);
5499 mutex_init(&mgr->probe_lock);
5500 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5501 mutex_init(&mgr->topology_ref_history_lock);
5504 INIT_LIST_HEAD(&mgr->tx_msg_downq);
5505 INIT_LIST_HEAD(&mgr->destroy_port_list);
5506 INIT_LIST_HEAD(&mgr->destroy_branch_device_list);
5507 INIT_LIST_HEAD(&mgr->up_req_list);
5510 * delayed_destroy_work will be queued on a dedicated WQ, so that any
5511 * requeuing will be also flushed when deiniting the topology manager.
5513 mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0);
5514 if (mgr->delayed_destroy_wq == NULL)
5517 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
5518 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
5519 INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work);
5520 INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work);
5521 init_waitqueue_head(&mgr->tx_waitq);
5524 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
5525 mgr->max_payloads = max_payloads;
5526 mgr->max_lane_count = max_lane_count;
5527 mgr->max_link_rate = max_link_rate;
5528 mgr->conn_base_id = conn_base_id;
5529 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
5530 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
5532 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
5535 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
5536 if (!mgr->proposed_vcpis)
5538 set_bit(0, &mgr->payload_mask);
5540 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
5541 if (mst_state == NULL)
5544 mst_state->total_avail_slots = 63;
5545 mst_state->start_slot = 1;
5547 mst_state->mgr = mgr;
5548 INIT_LIST_HEAD(&mst_state->vcpis);
5550 drm_atomic_private_obj_init(dev, &mgr->base,
5552 &drm_dp_mst_topology_state_funcs);
5556 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
5559 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
5560 * @mgr: manager to destroy
5562 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
5564 drm_dp_mst_topology_mgr_set_mst(mgr, false);
5565 flush_work(&mgr->work);
5566 /* The following will also drain any requeued work on the WQ. */
5567 if (mgr->delayed_destroy_wq) {
5568 destroy_workqueue(mgr->delayed_destroy_wq);
5569 mgr->delayed_destroy_wq = NULL;
5571 mutex_lock(&mgr->payload_lock);
5572 kfree(mgr->payloads);
5573 mgr->payloads = NULL;
5574 kfree(mgr->proposed_vcpis);
5575 mgr->proposed_vcpis = NULL;
5576 mutex_unlock(&mgr->payload_lock);
5579 drm_atomic_private_obj_fini(&mgr->base);
5582 mutex_destroy(&mgr->delayed_destroy_lock);
5583 mutex_destroy(&mgr->payload_lock);
5584 mutex_destroy(&mgr->qlock);
5585 mutex_destroy(&mgr->lock);
5586 mutex_destroy(&mgr->up_req_lock);
5587 mutex_destroy(&mgr->probe_lock);
5588 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5589 mutex_destroy(&mgr->topology_ref_history_lock);
5592 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
5594 static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
5598 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
5601 for (i = 0; i < num - 1; i++) {
5602 if (msgs[i].flags & I2C_M_RD ||
5607 return msgs[num - 1].flags & I2C_M_RD &&
5608 msgs[num - 1].len <= 0xff;
5611 static bool remote_i2c_write_ok(const struct i2c_msg msgs[], int num)
5615 for (i = 0; i < num - 1; i++) {
5616 if (msgs[i].flags & I2C_M_RD || !(msgs[i].flags & I2C_M_STOP) ||
5621 return !(msgs[num - 1].flags & I2C_M_RD) && msgs[num - 1].len <= 0xff;
5624 static int drm_dp_mst_i2c_read(struct drm_dp_mst_branch *mstb,
5625 struct drm_dp_mst_port *port,
5626 struct i2c_msg *msgs, int num)
5628 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5630 struct drm_dp_sideband_msg_req_body msg;
5631 struct drm_dp_sideband_msg_tx *txmsg = NULL;
5634 memset(&msg, 0, sizeof(msg));
5635 msg.req_type = DP_REMOTE_I2C_READ;
5636 msg.u.i2c_read.num_transactions = num - 1;
5637 msg.u.i2c_read.port_number = port->port_num;
5638 for (i = 0; i < num - 1; i++) {
5639 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
5640 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
5641 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
5642 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
5644 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
5645 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
5647 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5654 drm_dp_encode_sideband_req(&msg, txmsg);
5656 drm_dp_queue_down_tx(mgr, txmsg);
5658 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5661 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5665 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
5669 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
5677 static int drm_dp_mst_i2c_write(struct drm_dp_mst_branch *mstb,
5678 struct drm_dp_mst_port *port,
5679 struct i2c_msg *msgs, int num)
5681 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5683 struct drm_dp_sideband_msg_req_body msg;
5684 struct drm_dp_sideband_msg_tx *txmsg = NULL;
5687 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5692 for (i = 0; i < num; i++) {
5693 memset(&msg, 0, sizeof(msg));
5694 msg.req_type = DP_REMOTE_I2C_WRITE;
5695 msg.u.i2c_write.port_number = port->port_num;
5696 msg.u.i2c_write.write_i2c_device_id = msgs[i].addr;
5697 msg.u.i2c_write.num_bytes = msgs[i].len;
5698 msg.u.i2c_write.bytes = msgs[i].buf;
5700 memset(txmsg, 0, sizeof(*txmsg));
5703 drm_dp_encode_sideband_req(&msg, txmsg);
5704 drm_dp_queue_down_tx(mgr, txmsg);
5706 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5708 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5723 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter,
5724 struct i2c_msg *msgs, int num)
5726 struct drm_dp_aux *aux = adapter->algo_data;
5727 struct drm_dp_mst_port *port =
5728 container_of(aux, struct drm_dp_mst_port, aux);
5729 struct drm_dp_mst_branch *mstb;
5730 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5733 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
5737 if (remote_i2c_read_ok(msgs, num)) {
5738 ret = drm_dp_mst_i2c_read(mstb, port, msgs, num);
5739 } else if (remote_i2c_write_ok(msgs, num)) {
5740 ret = drm_dp_mst_i2c_write(mstb, port, msgs, num);
5742 drm_dbg_kms(mgr->dev, "Unsupported I2C transaction for MST device\n");
5746 drm_dp_mst_topology_put_mstb(mstb);
5750 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
5752 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
5753 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
5754 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
5755 I2C_FUNC_10BIT_ADDR;
5758 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
5759 .functionality = drm_dp_mst_i2c_functionality,
5760 .master_xfer = drm_dp_mst_i2c_xfer,
5764 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
5765 * @port: The port to add the I2C bus on
5767 * Returns 0 on success or a negative error code on failure.
5769 static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port)
5771 struct drm_dp_aux *aux = &port->aux;
5772 struct device *parent_dev = port->mgr->dev->dev;
5774 aux->ddc.algo = &drm_dp_mst_i2c_algo;
5775 aux->ddc.algo_data = aux;
5776 aux->ddc.retries = 3;
5778 aux->ddc.class = I2C_CLASS_DDC;
5779 aux->ddc.owner = THIS_MODULE;
5780 /* FIXME: set the kdev of the port's connector as parent */
5781 aux->ddc.dev.parent = parent_dev;
5782 aux->ddc.dev.of_node = parent_dev->of_node;
5784 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev),
5785 sizeof(aux->ddc.name));
5787 return i2c_add_adapter(&aux->ddc);
5791 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
5792 * @port: The port to remove the I2C bus from
5794 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port)
5796 i2c_del_adapter(&port->aux.ddc);
5800 * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device
5801 * @port: The port to check
5803 * A single physical MST hub object can be represented in the topology
5804 * by multiple branches, with virtual ports between those branches.
5806 * As of DP1.4, An MST hub with internal (virtual) ports must expose
5807 * certain DPCD registers over those ports. See sections 2.6.1.1.1
5808 * and 2.6.1.1.2 of Display Port specification v1.4 for details.
5810 * May acquire mgr->lock
5813 * true if the port is a virtual DP peer device, false otherwise
5815 static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port)
5817 struct drm_dp_mst_port *downstream_port;
5819 if (!port || port->dpcd_rev < DP_DPCD_REV_14)
5822 /* Virtual DP Sink (Internal Display Panel) */
5823 if (port->port_num >= 8)
5826 /* DP-to-HDMI Protocol Converter */
5827 if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV &&
5833 mutex_lock(&port->mgr->lock);
5834 if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
5836 port->mstb->num_ports == 2) {
5837 list_for_each_entry(downstream_port, &port->mstb->ports, next) {
5838 if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK &&
5839 !downstream_port->input) {
5840 mutex_unlock(&port->mgr->lock);
5845 mutex_unlock(&port->mgr->lock);
5851 * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
5852 * @port: The port to check. A leaf of the MST tree with an attached display.
5854 * Depending on the situation, DSC may be enabled via the endpoint aux,
5855 * the immediately upstream aux, or the connector's physical aux.
5857 * This is both the correct aux to read DSC_CAPABILITY and the
5858 * correct aux to write DSC_ENABLED.
5860 * This operation can be expensive (up to four aux reads), so
5861 * the caller should cache the return.
5864 * NULL if DSC cannot be enabled on this port, otherwise the aux device
5866 struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
5868 struct drm_dp_mst_port *immediate_upstream_port;
5869 struct drm_dp_mst_port *fec_port;
5870 struct drm_dp_desc desc = {};
5877 if (port->parent->port_parent)
5878 immediate_upstream_port = port->parent->port_parent;
5880 immediate_upstream_port = NULL;
5882 fec_port = immediate_upstream_port;
5885 * Each physical link (i.e. not a virtual port) between the
5886 * output and the primary device must support FEC
5888 if (!drm_dp_mst_is_virtual_dpcd(fec_port) &&
5889 !fec_port->fec_capable)
5892 fec_port = fec_port->parent->port_parent;
5895 /* DP-to-DP peer device */
5896 if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) {
5899 if (drm_dp_dpcd_read(&port->aux,
5900 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5902 if (drm_dp_dpcd_read(&port->aux,
5903 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5905 if (drm_dp_dpcd_read(&immediate_upstream_port->aux,
5906 DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
5909 /* Enpoint decompression with DP-to-DP peer device */
5910 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5911 (endpoint_fec & DP_FEC_CAPABLE) &&
5912 (upstream_dsc & 0x2) /* DSC passthrough */)
5915 /* Virtual DPCD decompression with DP-to-DP peer device */
5916 return &immediate_upstream_port->aux;
5919 /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */
5920 if (drm_dp_mst_is_virtual_dpcd(port))
5925 * Applies to ports for which:
5926 * - Physical aux has Synaptics OUI
5927 * - DPv1.4 or higher
5928 * - Port is on primary branch device
5929 * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG)
5931 if (drm_dp_read_desc(port->mgr->aux, &desc, true))
5934 if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) &&
5935 port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 &&
5936 port->parent == port->mgr->mst_primary) {
5937 u8 dpcd_ext[DP_RECEIVER_CAP_SIZE];
5939 if (drm_dp_read_dpcd_caps(port->mgr->aux, dpcd_ext) < 0)
5942 if ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT) &&
5943 ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK)
5944 != DP_DWN_STRM_PORT_TYPE_ANALOG))
5945 return port->mgr->aux;
5949 * The check below verifies if the MST sink
5950 * connected to the GPU is capable of DSC -
5951 * therefore the endpoint needs to be
5952 * both DSC and FEC capable.
5954 if (drm_dp_dpcd_read(&port->aux,
5955 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5957 if (drm_dp_dpcd_read(&port->aux,
5958 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5960 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5961 (endpoint_fec & DP_FEC_CAPABLE))
5966 EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);