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/drm_atomic.h>
42 #include <drm/drm_atomic_helper.h>
43 #include <drm/drm_dp_mst_helper.h>
44 #include <drm/drm_drv.h>
45 #include <drm/drm_print.h>
46 #include <drm/drm_probe_helper.h>
48 #include "drm_crtc_helper_internal.h"
49 #include "drm_dp_mst_topology_internal.h"
54 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
55 * protocol. The helpers contain a topology manager and bandwidth manager.
56 * The helpers encapsulate the sending and received of sideband msgs.
58 struct drm_dp_pending_up_req {
59 struct drm_dp_sideband_msg_hdr hdr;
60 struct drm_dp_sideband_msg_req_body msg;
61 struct list_head next;
64 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
67 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
69 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
71 struct drm_dp_payload *payload);
73 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
74 struct drm_dp_mst_port *port,
75 int offset, int size, u8 *bytes);
76 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
77 struct drm_dp_mst_port *port,
78 int offset, int size, u8 *bytes);
80 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
81 struct drm_dp_mst_branch *mstb);
84 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
85 struct drm_dp_mst_branch *mstb);
87 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
88 struct drm_dp_mst_branch *mstb,
89 struct drm_dp_mst_port *port);
90 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
93 static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port);
94 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port);
95 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
97 #define DBG_PREFIX "[dp_mst]"
99 #define DP_STR(x) [DP_ ## x] = #x
101 static const char *drm_dp_mst_req_type_str(u8 req_type)
103 static const char * const req_type_str[] = {
104 DP_STR(GET_MSG_TRANSACTION_VERSION),
105 DP_STR(LINK_ADDRESS),
106 DP_STR(CONNECTION_STATUS_NOTIFY),
107 DP_STR(ENUM_PATH_RESOURCES),
108 DP_STR(ALLOCATE_PAYLOAD),
109 DP_STR(QUERY_PAYLOAD),
110 DP_STR(RESOURCE_STATUS_NOTIFY),
111 DP_STR(CLEAR_PAYLOAD_ID_TABLE),
112 DP_STR(REMOTE_DPCD_READ),
113 DP_STR(REMOTE_DPCD_WRITE),
114 DP_STR(REMOTE_I2C_READ),
115 DP_STR(REMOTE_I2C_WRITE),
116 DP_STR(POWER_UP_PHY),
117 DP_STR(POWER_DOWN_PHY),
118 DP_STR(SINK_EVENT_NOTIFY),
119 DP_STR(QUERY_STREAM_ENC_STATUS),
122 if (req_type >= ARRAY_SIZE(req_type_str) ||
123 !req_type_str[req_type])
126 return req_type_str[req_type];
130 #define DP_STR(x) [DP_NAK_ ## x] = #x
132 static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
134 static const char * const nak_reason_str[] = {
135 DP_STR(WRITE_FAILURE),
136 DP_STR(INVALID_READ),
140 DP_STR(LINK_FAILURE),
141 DP_STR(NO_RESOURCES),
144 DP_STR(ALLOCATE_FAIL),
147 if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
148 !nak_reason_str[nak_reason])
151 return nak_reason_str[nak_reason];
155 #define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x
157 static const char *drm_dp_mst_sideband_tx_state_str(int state)
159 static const char * const sideband_reason_str[] = {
167 if (state >= ARRAY_SIZE(sideband_reason_str) ||
168 !sideband_reason_str[state])
171 return sideband_reason_str[state];
175 drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len)
180 for (i = 0; i < lct; i++) {
182 unpacked_rad[i] = rad[i / 2] >> 4;
184 unpacked_rad[i] = rad[i / 2] & BIT_MASK(4);
187 /* TODO: Eventually add something to printk so we can format the rad
190 return snprintf(out, len, "%*phC", lct, unpacked_rad);
193 /* sideband msg handling */
194 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
199 int number_of_bits = num_nibbles * 4;
202 while (number_of_bits != 0) {
205 remainder |= (data[array_index] & bitmask) >> bitshift;
213 if ((remainder & 0x10) == 0x10)
218 while (number_of_bits != 0) {
221 if ((remainder & 0x10) != 0)
228 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
233 int number_of_bits = number_of_bytes * 8;
236 while (number_of_bits != 0) {
239 remainder |= (data[array_index] & bitmask) >> bitshift;
247 if ((remainder & 0x100) == 0x100)
252 while (number_of_bits != 0) {
255 if ((remainder & 0x100) != 0)
259 return remainder & 0xff;
261 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
265 size += (hdr->lct / 2);
269 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
276 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
277 for (i = 0; i < (hdr->lct / 2); i++)
278 buf[idx++] = hdr->rad[i];
279 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
280 (hdr->msg_len & 0x3f);
281 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
283 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
284 buf[idx - 1] |= (crc4 & 0xf);
289 static bool drm_dp_decode_sideband_msg_hdr(const struct drm_dp_mst_topology_mgr *mgr,
290 struct drm_dp_sideband_msg_hdr *hdr,
291 u8 *buf, int buflen, u8 *hdrlen)
301 len += ((buf[0] & 0xf0) >> 4) / 2;
304 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
306 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
307 drm_dbg_kms(mgr->dev, "crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
311 hdr->lct = (buf[0] & 0xf0) >> 4;
312 hdr->lcr = (buf[0] & 0xf);
314 for (i = 0; i < (hdr->lct / 2); i++)
315 hdr->rad[i] = buf[idx++];
316 hdr->broadcast = (buf[idx] >> 7) & 0x1;
317 hdr->path_msg = (buf[idx] >> 6) & 0x1;
318 hdr->msg_len = buf[idx] & 0x3f;
320 hdr->somt = (buf[idx] >> 7) & 0x1;
321 hdr->eomt = (buf[idx] >> 6) & 0x1;
322 hdr->seqno = (buf[idx] >> 4) & 0x1;
329 drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
330 struct drm_dp_sideband_msg_tx *raw)
336 buf[idx++] = req->req_type & 0x7f;
338 switch (req->req_type) {
339 case DP_ENUM_PATH_RESOURCES:
340 case DP_POWER_DOWN_PHY:
341 case DP_POWER_UP_PHY:
342 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
345 case DP_ALLOCATE_PAYLOAD:
346 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
347 (req->u.allocate_payload.number_sdp_streams & 0xf);
349 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
351 buf[idx] = (req->u.allocate_payload.pbn >> 8);
353 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
355 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
356 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
357 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
360 if (req->u.allocate_payload.number_sdp_streams & 1) {
361 i = req->u.allocate_payload.number_sdp_streams - 1;
362 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
366 case DP_QUERY_PAYLOAD:
367 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
369 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
372 case DP_REMOTE_DPCD_READ:
373 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
374 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
376 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
378 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
380 buf[idx] = (req->u.dpcd_read.num_bytes);
384 case DP_REMOTE_DPCD_WRITE:
385 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
386 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
388 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
390 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
392 buf[idx] = (req->u.dpcd_write.num_bytes);
394 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
395 idx += req->u.dpcd_write.num_bytes;
397 case DP_REMOTE_I2C_READ:
398 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
399 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
401 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
402 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
404 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
406 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
407 idx += req->u.i2c_read.transactions[i].num_bytes;
409 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4;
410 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
413 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
415 buf[idx] = (req->u.i2c_read.num_bytes_read);
419 case DP_REMOTE_I2C_WRITE:
420 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
422 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
424 buf[idx] = (req->u.i2c_write.num_bytes);
426 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
427 idx += req->u.i2c_write.num_bytes;
429 case DP_QUERY_STREAM_ENC_STATUS: {
430 const struct drm_dp_query_stream_enc_status *msg;
432 msg = &req->u.enc_status;
433 buf[idx] = msg->stream_id;
435 memcpy(&buf[idx], msg->client_id, sizeof(msg->client_id));
436 idx += sizeof(msg->client_id);
438 buf[idx] |= FIELD_PREP(GENMASK(1, 0), msg->stream_event);
439 buf[idx] |= msg->valid_stream_event ? BIT(2) : 0;
440 buf[idx] |= FIELD_PREP(GENMASK(4, 3), msg->stream_behavior);
441 buf[idx] |= msg->valid_stream_behavior ? BIT(5) : 0;
448 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req);
450 /* Decode a sideband request we've encoded, mainly used for debugging */
452 drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
453 struct drm_dp_sideband_msg_req_body *req)
455 const u8 *buf = raw->msg;
458 req->req_type = buf[idx++] & 0x7f;
459 switch (req->req_type) {
460 case DP_ENUM_PATH_RESOURCES:
461 case DP_POWER_DOWN_PHY:
462 case DP_POWER_UP_PHY:
463 req->u.port_num.port_number = (buf[idx] >> 4) & 0xf;
465 case DP_ALLOCATE_PAYLOAD:
467 struct drm_dp_allocate_payload *a =
468 &req->u.allocate_payload;
470 a->number_sdp_streams = buf[idx] & 0xf;
471 a->port_number = (buf[idx] >> 4) & 0xf;
473 WARN_ON(buf[++idx] & 0x80);
474 a->vcpi = buf[idx] & 0x7f;
476 a->pbn = buf[++idx] << 8;
477 a->pbn |= buf[++idx];
480 for (i = 0; i < a->number_sdp_streams; i++) {
481 a->sdp_stream_sink[i] =
482 (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf;
486 case DP_QUERY_PAYLOAD:
487 req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf;
488 WARN_ON(buf[++idx] & 0x80);
489 req->u.query_payload.vcpi = buf[idx] & 0x7f;
491 case DP_REMOTE_DPCD_READ:
493 struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read;
495 r->port_number = (buf[idx] >> 4) & 0xf;
497 r->dpcd_address = (buf[idx] << 16) & 0xf0000;
498 r->dpcd_address |= (buf[++idx] << 8) & 0xff00;
499 r->dpcd_address |= buf[++idx] & 0xff;
501 r->num_bytes = buf[++idx];
504 case DP_REMOTE_DPCD_WRITE:
506 struct drm_dp_remote_dpcd_write *w =
509 w->port_number = (buf[idx] >> 4) & 0xf;
511 w->dpcd_address = (buf[idx] << 16) & 0xf0000;
512 w->dpcd_address |= (buf[++idx] << 8) & 0xff00;
513 w->dpcd_address |= buf[++idx] & 0xff;
515 w->num_bytes = buf[++idx];
517 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
523 case DP_REMOTE_I2C_READ:
525 struct drm_dp_remote_i2c_read *r = &req->u.i2c_read;
526 struct drm_dp_remote_i2c_read_tx *tx;
529 r->num_transactions = buf[idx] & 0x3;
530 r->port_number = (buf[idx] >> 4) & 0xf;
531 for (i = 0; i < r->num_transactions; i++) {
532 tx = &r->transactions[i];
534 tx->i2c_dev_id = buf[++idx] & 0x7f;
535 tx->num_bytes = buf[++idx];
536 tx->bytes = kmemdup(&buf[++idx],
543 idx += tx->num_bytes;
544 tx->no_stop_bit = (buf[idx] >> 5) & 0x1;
545 tx->i2c_transaction_delay = buf[idx] & 0xf;
549 for (i = 0; i < r->num_transactions; i++) {
550 tx = &r->transactions[i];
556 r->read_i2c_device_id = buf[++idx] & 0x7f;
557 r->num_bytes_read = buf[++idx];
560 case DP_REMOTE_I2C_WRITE:
562 struct drm_dp_remote_i2c_write *w = &req->u.i2c_write;
564 w->port_number = (buf[idx] >> 4) & 0xf;
565 w->write_i2c_device_id = buf[++idx] & 0x7f;
566 w->num_bytes = buf[++idx];
567 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
573 case DP_QUERY_STREAM_ENC_STATUS:
574 req->u.enc_status.stream_id = buf[idx++];
575 for (i = 0; i < sizeof(req->u.enc_status.client_id); i++)
576 req->u.enc_status.client_id[i] = buf[idx++];
578 req->u.enc_status.stream_event = FIELD_GET(GENMASK(1, 0),
580 req->u.enc_status.valid_stream_event = FIELD_GET(BIT(2),
582 req->u.enc_status.stream_behavior = FIELD_GET(GENMASK(4, 3),
584 req->u.enc_status.valid_stream_behavior = FIELD_GET(BIT(5),
591 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req);
594 drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req,
595 int indent, struct drm_printer *printer)
599 #define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__)
600 if (req->req_type == DP_LINK_ADDRESS) {
601 /* No contents to print */
602 P("type=%s\n", drm_dp_mst_req_type_str(req->req_type));
606 P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type));
609 switch (req->req_type) {
610 case DP_ENUM_PATH_RESOURCES:
611 case DP_POWER_DOWN_PHY:
612 case DP_POWER_UP_PHY:
613 P("port=%d\n", req->u.port_num.port_number);
615 case DP_ALLOCATE_PAYLOAD:
616 P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n",
617 req->u.allocate_payload.port_number,
618 req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn,
619 req->u.allocate_payload.number_sdp_streams,
620 req->u.allocate_payload.number_sdp_streams,
621 req->u.allocate_payload.sdp_stream_sink);
623 case DP_QUERY_PAYLOAD:
624 P("port=%d vcpi=%d\n",
625 req->u.query_payload.port_number,
626 req->u.query_payload.vcpi);
628 case DP_REMOTE_DPCD_READ:
629 P("port=%d dpcd_addr=%05x len=%d\n",
630 req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address,
631 req->u.dpcd_read.num_bytes);
633 case DP_REMOTE_DPCD_WRITE:
634 P("port=%d addr=%05x len=%d: %*ph\n",
635 req->u.dpcd_write.port_number,
636 req->u.dpcd_write.dpcd_address,
637 req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes,
638 req->u.dpcd_write.bytes);
640 case DP_REMOTE_I2C_READ:
641 P("port=%d num_tx=%d id=%d size=%d:\n",
642 req->u.i2c_read.port_number,
643 req->u.i2c_read.num_transactions,
644 req->u.i2c_read.read_i2c_device_id,
645 req->u.i2c_read.num_bytes_read);
648 for (i = 0; i < req->u.i2c_read.num_transactions; i++) {
649 const struct drm_dp_remote_i2c_read_tx *rtx =
650 &req->u.i2c_read.transactions[i];
652 P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n",
653 i, rtx->i2c_dev_id, rtx->num_bytes,
654 rtx->no_stop_bit, rtx->i2c_transaction_delay,
655 rtx->num_bytes, rtx->bytes);
658 case DP_REMOTE_I2C_WRITE:
659 P("port=%d id=%d size=%d: %*ph\n",
660 req->u.i2c_write.port_number,
661 req->u.i2c_write.write_i2c_device_id,
662 req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes,
663 req->u.i2c_write.bytes);
665 case DP_QUERY_STREAM_ENC_STATUS:
666 P("stream_id=%u client_id=%*ph stream_event=%x "
667 "valid_event=%d stream_behavior=%x valid_behavior=%d",
668 req->u.enc_status.stream_id,
669 (int)ARRAY_SIZE(req->u.enc_status.client_id),
670 req->u.enc_status.client_id, req->u.enc_status.stream_event,
671 req->u.enc_status.valid_stream_event,
672 req->u.enc_status.stream_behavior,
673 req->u.enc_status.valid_stream_behavior);
681 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body);
684 drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p,
685 const struct drm_dp_sideband_msg_tx *txmsg)
687 struct drm_dp_sideband_msg_req_body req;
692 drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf,
694 drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n",
695 txmsg->cur_offset, txmsg->cur_len, txmsg->seqno,
696 drm_dp_mst_sideband_tx_state_str(txmsg->state),
697 txmsg->path_msg, buf);
699 ret = drm_dp_decode_sideband_req(txmsg, &req);
701 drm_printf(p, "<failed to decode sideband req: %d>\n", ret);
704 drm_dp_dump_sideband_msg_req_body(&req, 1, p);
706 switch (req.req_type) {
707 case DP_REMOTE_DPCD_WRITE:
708 kfree(req.u.dpcd_write.bytes);
710 case DP_REMOTE_I2C_READ:
711 for (i = 0; i < req.u.i2c_read.num_transactions; i++)
712 kfree(req.u.i2c_read.transactions[i].bytes);
714 case DP_REMOTE_I2C_WRITE:
715 kfree(req.u.i2c_write.bytes);
720 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
724 crc4 = drm_dp_msg_data_crc4(msg, len);
728 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
729 struct drm_dp_sideband_msg_tx *raw)
734 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
739 static int drm_dp_sideband_msg_set_header(struct drm_dp_sideband_msg_rx *msg,
740 struct drm_dp_sideband_msg_hdr *hdr,
744 * ignore out-of-order messages or messages that are part of a
747 if (!hdr->somt && !msg->have_somt)
750 /* get length contained in this portion */
751 msg->curchunk_idx = 0;
752 msg->curchunk_len = hdr->msg_len;
753 msg->curchunk_hdrlen = hdrlen;
755 /* we have already gotten an somt - don't bother parsing */
756 if (hdr->somt && msg->have_somt)
760 memcpy(&msg->initial_hdr, hdr,
761 sizeof(struct drm_dp_sideband_msg_hdr));
762 msg->have_somt = true;
765 msg->have_eomt = true;
770 /* this adds a chunk of msg to the builder to get the final msg */
771 static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx *msg,
772 u8 *replybuf, u8 replybuflen)
776 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
777 msg->curchunk_idx += replybuflen;
779 if (msg->curchunk_idx >= msg->curchunk_len) {
781 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
782 if (crc4 != msg->chunk[msg->curchunk_len - 1])
783 print_hex_dump(KERN_DEBUG, "wrong crc",
784 DUMP_PREFIX_NONE, 16, 1,
785 msg->chunk, msg->curchunk_len, false);
786 /* copy chunk into bigger msg */
787 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
788 msg->curlen += msg->curchunk_len - 1;
793 static bool drm_dp_sideband_parse_link_address(const struct drm_dp_mst_topology_mgr *mgr,
794 struct drm_dp_sideband_msg_rx *raw,
795 struct drm_dp_sideband_msg_reply_body *repmsg)
800 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
802 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
804 if (idx > raw->curlen)
806 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
807 if (raw->msg[idx] & 0x80)
808 repmsg->u.link_addr.ports[i].input_port = 1;
810 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
811 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
814 if (idx > raw->curlen)
816 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
817 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
818 if (repmsg->u.link_addr.ports[i].input_port == 0)
819 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
821 if (idx > raw->curlen)
823 if (repmsg->u.link_addr.ports[i].input_port == 0) {
824 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
826 if (idx > raw->curlen)
828 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
830 if (idx > raw->curlen)
832 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
833 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
837 if (idx > raw->curlen)
843 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
847 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
848 struct drm_dp_sideband_msg_reply_body *repmsg)
852 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
854 if (idx > raw->curlen)
856 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
858 if (idx > raw->curlen)
861 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
864 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
868 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
869 struct drm_dp_sideband_msg_reply_body *repmsg)
873 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
875 if (idx > raw->curlen)
879 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
883 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
884 struct drm_dp_sideband_msg_reply_body *repmsg)
888 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
890 if (idx > raw->curlen)
892 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
895 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
898 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
902 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
903 struct drm_dp_sideband_msg_reply_body *repmsg)
907 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
908 repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1;
910 if (idx > raw->curlen)
912 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
914 if (idx > raw->curlen)
916 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
918 if (idx > raw->curlen)
922 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
926 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
927 struct drm_dp_sideband_msg_reply_body *repmsg)
931 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
933 if (idx > raw->curlen)
935 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
937 if (idx > raw->curlen)
939 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
941 if (idx > raw->curlen)
945 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
949 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
950 struct drm_dp_sideband_msg_reply_body *repmsg)
954 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
956 if (idx > raw->curlen)
958 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
960 if (idx > raw->curlen)
964 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
968 static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
969 struct drm_dp_sideband_msg_reply_body *repmsg)
973 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
975 if (idx > raw->curlen) {
976 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
984 drm_dp_sideband_parse_query_stream_enc_status(
985 struct drm_dp_sideband_msg_rx *raw,
986 struct drm_dp_sideband_msg_reply_body *repmsg)
988 struct drm_dp_query_stream_enc_status_ack_reply *reply;
990 reply = &repmsg->u.enc_status;
992 reply->stream_id = raw->msg[3];
994 reply->reply_signed = raw->msg[2] & BIT(0);
997 * NOTE: It's my impression from reading the spec that the below parsing
998 * is correct. However I noticed while testing with an HDCP 1.4 display
999 * through an HDCP 2.2 hub that only bit 3 was set. In that case, I
1000 * would expect both bits to be set. So keep the parsing following the
1001 * spec, but beware reality might not match the spec (at least for some
1004 reply->hdcp_1x_device_present = raw->msg[2] & BIT(4);
1005 reply->hdcp_2x_device_present = raw->msg[2] & BIT(3);
1007 reply->query_capable_device_present = raw->msg[2] & BIT(5);
1008 reply->legacy_device_present = raw->msg[2] & BIT(6);
1009 reply->unauthorizable_device_present = raw->msg[2] & BIT(7);
1011 reply->auth_completed = !!(raw->msg[1] & BIT(3));
1012 reply->encryption_enabled = !!(raw->msg[1] & BIT(4));
1013 reply->repeater_present = !!(raw->msg[1] & BIT(5));
1014 reply->state = (raw->msg[1] & GENMASK(7, 6)) >> 6;
1019 static bool drm_dp_sideband_parse_reply(const struct drm_dp_mst_topology_mgr *mgr,
1020 struct drm_dp_sideband_msg_rx *raw,
1021 struct drm_dp_sideband_msg_reply_body *msg)
1023 memset(msg, 0, sizeof(*msg));
1024 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
1025 msg->req_type = (raw->msg[0] & 0x7f);
1027 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
1028 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
1029 msg->u.nak.reason = raw->msg[17];
1030 msg->u.nak.nak_data = raw->msg[18];
1034 switch (msg->req_type) {
1035 case DP_LINK_ADDRESS:
1036 return drm_dp_sideband_parse_link_address(mgr, raw, msg);
1037 case DP_QUERY_PAYLOAD:
1038 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
1039 case DP_REMOTE_DPCD_READ:
1040 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
1041 case DP_REMOTE_DPCD_WRITE:
1042 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
1043 case DP_REMOTE_I2C_READ:
1044 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
1045 case DP_REMOTE_I2C_WRITE:
1046 return true; /* since there's nothing to parse */
1047 case DP_ENUM_PATH_RESOURCES:
1048 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
1049 case DP_ALLOCATE_PAYLOAD:
1050 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
1051 case DP_POWER_DOWN_PHY:
1052 case DP_POWER_UP_PHY:
1053 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
1054 case DP_CLEAR_PAYLOAD_ID_TABLE:
1055 return true; /* since there's nothing to parse */
1056 case DP_QUERY_STREAM_ENC_STATUS:
1057 return drm_dp_sideband_parse_query_stream_enc_status(raw, msg);
1059 drm_err(mgr->dev, "Got unknown reply 0x%02x (%s)\n",
1060 msg->req_type, drm_dp_mst_req_type_str(msg->req_type));
1066 drm_dp_sideband_parse_connection_status_notify(const struct drm_dp_mst_topology_mgr *mgr,
1067 struct drm_dp_sideband_msg_rx *raw,
1068 struct drm_dp_sideband_msg_req_body *msg)
1072 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
1074 if (idx > raw->curlen)
1077 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
1079 if (idx > raw->curlen)
1082 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
1083 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
1084 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
1085 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
1086 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
1090 drm_dbg_kms(mgr->dev, "connection status reply parse length fail %d %d\n",
1095 static bool drm_dp_sideband_parse_resource_status_notify(const struct drm_dp_mst_topology_mgr *mgr,
1096 struct drm_dp_sideband_msg_rx *raw,
1097 struct drm_dp_sideband_msg_req_body *msg)
1101 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
1103 if (idx > raw->curlen)
1106 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
1108 if (idx > raw->curlen)
1111 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
1115 drm_dbg_kms(mgr->dev, "resource status reply parse length fail %d %d\n", idx, raw->curlen);
1119 static bool drm_dp_sideband_parse_req(const struct drm_dp_mst_topology_mgr *mgr,
1120 struct drm_dp_sideband_msg_rx *raw,
1121 struct drm_dp_sideband_msg_req_body *msg)
1123 memset(msg, 0, sizeof(*msg));
1124 msg->req_type = (raw->msg[0] & 0x7f);
1126 switch (msg->req_type) {
1127 case DP_CONNECTION_STATUS_NOTIFY:
1128 return drm_dp_sideband_parse_connection_status_notify(mgr, raw, msg);
1129 case DP_RESOURCE_STATUS_NOTIFY:
1130 return drm_dp_sideband_parse_resource_status_notify(mgr, raw, msg);
1132 drm_err(mgr->dev, "Got unknown request 0x%02x (%s)\n",
1133 msg->req_type, drm_dp_mst_req_type_str(msg->req_type));
1138 static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg,
1139 u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
1141 struct drm_dp_sideband_msg_req_body req;
1143 req.req_type = DP_REMOTE_DPCD_WRITE;
1144 req.u.dpcd_write.port_number = port_num;
1145 req.u.dpcd_write.dpcd_address = offset;
1146 req.u.dpcd_write.num_bytes = num_bytes;
1147 req.u.dpcd_write.bytes = bytes;
1148 drm_dp_encode_sideband_req(&req, msg);
1151 static void build_link_address(struct drm_dp_sideband_msg_tx *msg)
1153 struct drm_dp_sideband_msg_req_body req;
1155 req.req_type = DP_LINK_ADDRESS;
1156 drm_dp_encode_sideband_req(&req, msg);
1159 static void build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
1161 struct drm_dp_sideband_msg_req_body req;
1163 req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE;
1164 drm_dp_encode_sideband_req(&req, msg);
1165 msg->path_msg = true;
1168 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg,
1171 struct drm_dp_sideband_msg_req_body req;
1173 req.req_type = DP_ENUM_PATH_RESOURCES;
1174 req.u.port_num.port_number = port_num;
1175 drm_dp_encode_sideband_req(&req, msg);
1176 msg->path_msg = true;
1180 static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg,
1182 u8 vcpi, uint16_t pbn,
1183 u8 number_sdp_streams,
1184 u8 *sdp_stream_sink)
1186 struct drm_dp_sideband_msg_req_body req;
1188 memset(&req, 0, sizeof(req));
1189 req.req_type = DP_ALLOCATE_PAYLOAD;
1190 req.u.allocate_payload.port_number = port_num;
1191 req.u.allocate_payload.vcpi = vcpi;
1192 req.u.allocate_payload.pbn = pbn;
1193 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
1194 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
1195 number_sdp_streams);
1196 drm_dp_encode_sideband_req(&req, msg);
1197 msg->path_msg = true;
1200 static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
1201 int port_num, bool power_up)
1203 struct drm_dp_sideband_msg_req_body req;
1206 req.req_type = DP_POWER_UP_PHY;
1208 req.req_type = DP_POWER_DOWN_PHY;
1210 req.u.port_num.port_number = port_num;
1211 drm_dp_encode_sideband_req(&req, msg);
1212 msg->path_msg = true;
1216 build_query_stream_enc_status(struct drm_dp_sideband_msg_tx *msg, u8 stream_id,
1219 struct drm_dp_sideband_msg_req_body req;
1221 req.req_type = DP_QUERY_STREAM_ENC_STATUS;
1222 req.u.enc_status.stream_id = stream_id;
1223 memcpy(req.u.enc_status.client_id, q_id,
1224 sizeof(req.u.enc_status.client_id));
1225 req.u.enc_status.stream_event = 0;
1226 req.u.enc_status.valid_stream_event = false;
1227 req.u.enc_status.stream_behavior = 0;
1228 req.u.enc_status.valid_stream_behavior = false;
1230 drm_dp_encode_sideband_req(&req, msg);
1234 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1235 struct drm_dp_vcpi *vcpi)
1239 mutex_lock(&mgr->payload_lock);
1240 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
1241 if (ret > mgr->max_payloads) {
1243 drm_dbg_kms(mgr->dev, "out of payload ids %d\n", ret);
1247 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
1248 if (vcpi_ret > mgr->max_payloads) {
1250 drm_dbg_kms(mgr->dev, "out of vcpi ids %d\n", ret);
1254 set_bit(ret, &mgr->payload_mask);
1255 set_bit(vcpi_ret, &mgr->vcpi_mask);
1256 vcpi->vcpi = vcpi_ret + 1;
1257 mgr->proposed_vcpis[ret - 1] = vcpi;
1259 mutex_unlock(&mgr->payload_lock);
1263 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1271 mutex_lock(&mgr->payload_lock);
1272 drm_dbg_kms(mgr->dev, "putting payload %d\n", vcpi);
1273 clear_bit(vcpi - 1, &mgr->vcpi_mask);
1275 for (i = 0; i < mgr->max_payloads; i++) {
1276 if (mgr->proposed_vcpis[i] &&
1277 mgr->proposed_vcpis[i]->vcpi == vcpi) {
1278 mgr->proposed_vcpis[i] = NULL;
1279 clear_bit(i + 1, &mgr->payload_mask);
1282 mutex_unlock(&mgr->payload_lock);
1285 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
1286 struct drm_dp_sideband_msg_tx *txmsg)
1291 * All updates to txmsg->state are protected by mgr->qlock, and the two
1292 * cases we check here are terminal states. For those the barriers
1293 * provided by the wake_up/wait_event pair are enough.
1295 state = READ_ONCE(txmsg->state);
1296 return (state == DRM_DP_SIDEBAND_TX_RX ||
1297 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
1300 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
1301 struct drm_dp_sideband_msg_tx *txmsg)
1303 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1304 unsigned long wait_timeout = msecs_to_jiffies(4000);
1305 unsigned long wait_expires = jiffies + wait_timeout;
1310 * If the driver provides a way for this, change to
1311 * poll-waiting for the MST reply interrupt if we didn't receive
1312 * it for 50 msec. This would cater for cases where the HPD
1313 * pulse signal got lost somewhere, even though the sink raised
1314 * the corresponding MST interrupt correctly. One example is the
1315 * Club 3D CAC-1557 TypeC -> DP adapter which for some reason
1316 * filters out short pulses with a duration less than ~540 usec.
1318 * The poll period is 50 msec to avoid missing an interrupt
1319 * after the sink has cleared it (after a 110msec timeout
1320 * since it raised the interrupt).
1322 ret = wait_event_timeout(mgr->tx_waitq,
1323 check_txmsg_state(mgr, txmsg),
1324 mgr->cbs->poll_hpd_irq ?
1325 msecs_to_jiffies(50) :
1328 if (ret || !mgr->cbs->poll_hpd_irq ||
1329 time_after(jiffies, wait_expires))
1332 mgr->cbs->poll_hpd_irq(mgr);
1335 mutex_lock(&mgr->qlock);
1337 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
1342 drm_dbg_kms(mgr->dev, "timedout msg send %p %d %d\n",
1343 txmsg, txmsg->state, txmsg->seqno);
1345 /* dump some state */
1349 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
1350 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
1351 txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
1352 list_del(&txmsg->next);
1355 if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
1356 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1358 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
1360 mutex_unlock(&mgr->qlock);
1362 drm_dp_mst_kick_tx(mgr);
1366 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
1368 struct drm_dp_mst_branch *mstb;
1370 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
1376 memcpy(mstb->rad, rad, lct / 2);
1377 INIT_LIST_HEAD(&mstb->ports);
1378 kref_init(&mstb->topology_kref);
1379 kref_init(&mstb->malloc_kref);
1383 static void drm_dp_free_mst_branch_device(struct kref *kref)
1385 struct drm_dp_mst_branch *mstb =
1386 container_of(kref, struct drm_dp_mst_branch, malloc_kref);
1388 if (mstb->port_parent)
1389 drm_dp_mst_put_port_malloc(mstb->port_parent);
1395 * DOC: Branch device and port refcounting
1397 * Topology refcount overview
1398 * ~~~~~~~~~~~~~~~~~~~~~~~~~~
1400 * The refcounting schemes for &struct drm_dp_mst_branch and &struct
1401 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
1402 * two different kinds of refcounts: topology refcounts, and malloc refcounts.
1404 * Topology refcounts are not exposed to drivers, and are handled internally
1405 * by the DP MST helpers. The helpers use them in order to prevent the
1406 * in-memory topology state from being changed in the middle of critical
1407 * operations like changing the internal state of payload allocations. This
1408 * means each branch and port will be considered to be connected to the rest
1409 * of the topology until its topology refcount reaches zero. Additionally,
1410 * for ports this means that their associated &struct drm_connector will stay
1411 * registered with userspace until the port's refcount reaches 0.
1413 * Malloc refcount overview
1414 * ~~~~~~~~~~~~~~~~~~~~~~~~
1416 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct
1417 * drm_dp_mst_branch allocated even after all of its topology references have
1418 * been dropped, so that the driver or MST helpers can safely access each
1419 * branch's last known state before it was disconnected from the topology.
1420 * When the malloc refcount of a port or branch reaches 0, the memory
1421 * allocation containing the &struct drm_dp_mst_branch or &struct
1422 * drm_dp_mst_port respectively will be freed.
1424 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
1425 * to drivers. As of writing this documentation, there are no drivers that
1426 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
1427 * helpers. Exposing this API to drivers in a race-free manner would take more
1428 * tweaking of the refcounting scheme, however patches are welcome provided
1429 * there is a legitimate driver usecase for this.
1431 * Refcount relationships in a topology
1432 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1434 * Let's take a look at why the relationship between topology and malloc
1435 * refcounts is designed the way it is.
1437 * .. kernel-figure:: dp-mst/topology-figure-1.dot
1439 * An example of topology and malloc refs in a DP MST topology with two
1440 * active payloads. Topology refcount increments are indicated by solid
1441 * lines, and malloc refcount increments are indicated by dashed lines.
1442 * Each starts from the branch which incremented the refcount, and ends at
1443 * the branch to which the refcount belongs to, i.e. the arrow points the
1444 * same way as the C pointers used to reference a structure.
1446 * As you can see in the above figure, every branch increments the topology
1447 * refcount of its children, and increments the malloc refcount of its
1448 * parent. Additionally, every payload increments the malloc refcount of its
1449 * assigned port by 1.
1451 * So, what would happen if MSTB #3 from the above figure was unplugged from
1452 * the system, but the driver hadn't yet removed payload #2 from port #3? The
1453 * topology would start to look like the figure below.
1455 * .. kernel-figure:: dp-mst/topology-figure-2.dot
1457 * Ports and branch devices which have been released from memory are
1458 * colored grey, and references which have been removed are colored red.
1460 * Whenever a port or branch device's topology refcount reaches zero, it will
1461 * decrement the topology refcounts of all its children, the malloc refcount
1462 * of its parent, and finally its own malloc refcount. For MSTB #4 and port
1463 * #4, this means they both have been disconnected from the topology and freed
1464 * from memory. But, because payload #2 is still holding a reference to port
1465 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
1466 * is still accessible from memory. This also means port #3 has not yet
1467 * decremented the malloc refcount of MSTB #3, so its &struct
1468 * drm_dp_mst_branch will also stay allocated in memory until port #3's
1469 * malloc refcount reaches 0.
1471 * This relationship is necessary because in order to release payload #2, we
1472 * need to be able to figure out the last relative of port #3 that's still
1473 * connected to the topology. In this case, we would travel up the topology as
1476 * .. kernel-figure:: dp-mst/topology-figure-3.dot
1478 * And finally, remove payload #2 by communicating with port #2 through
1479 * sideband transactions.
1483 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
1485 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
1487 * Increments &drm_dp_mst_branch.malloc_kref. When
1488 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1489 * will be released and @mstb may no longer be used.
1491 * See also: drm_dp_mst_put_mstb_malloc()
1494 drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
1496 kref_get(&mstb->malloc_kref);
1497 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
1501 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
1503 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
1505 * Decrements &drm_dp_mst_branch.malloc_kref. When
1506 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1507 * will be released and @mstb may no longer be used.
1509 * See also: drm_dp_mst_get_mstb_malloc()
1512 drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
1514 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
1515 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
1518 static void drm_dp_free_mst_port(struct kref *kref)
1520 struct drm_dp_mst_port *port =
1521 container_of(kref, struct drm_dp_mst_port, malloc_kref);
1523 drm_dp_mst_put_mstb_malloc(port->parent);
1528 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
1529 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of
1531 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1532 * reaches 0, the memory allocation for @port will be released and @port may
1533 * no longer be used.
1535 * Because @port could potentially be freed at any time by the DP MST helpers
1536 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
1537 * function, drivers that which to make use of &struct drm_dp_mst_port should
1538 * ensure that they grab at least one main malloc reference to their MST ports
1539 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
1540 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
1542 * See also: drm_dp_mst_put_port_malloc()
1545 drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
1547 kref_get(&port->malloc_kref);
1548 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref));
1550 EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
1553 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
1554 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
1556 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1557 * reaches 0, the memory allocation for @port will be released and @port may
1558 * no longer be used.
1560 * See also: drm_dp_mst_get_port_malloc()
1563 drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
1565 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
1566 kref_put(&port->malloc_kref, drm_dp_free_mst_port);
1568 EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
1570 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
1572 #define STACK_DEPTH 8
1574 static noinline void
1575 __topology_ref_save(struct drm_dp_mst_topology_mgr *mgr,
1576 struct drm_dp_mst_topology_ref_history *history,
1577 enum drm_dp_mst_topology_ref_type type)
1579 struct drm_dp_mst_topology_ref_entry *entry = NULL;
1580 depot_stack_handle_t backtrace;
1581 ulong stack_entries[STACK_DEPTH];
1585 n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1);
1586 backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL);
1590 /* Try to find an existing entry for this backtrace */
1591 for (i = 0; i < history->len; i++) {
1592 if (history->entries[i].backtrace == backtrace) {
1593 entry = &history->entries[i];
1598 /* Otherwise add one */
1600 struct drm_dp_mst_topology_ref_entry *new;
1601 int new_len = history->len + 1;
1603 new = krealloc(history->entries, sizeof(*new) * new_len,
1608 entry = &new[history->len];
1609 history->len = new_len;
1610 history->entries = new;
1612 entry->backtrace = backtrace;
1617 entry->ts_nsec = ktime_get_ns();
1621 topology_ref_history_cmp(const void *a, const void *b)
1623 const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b;
1625 if (entry_a->ts_nsec > entry_b->ts_nsec)
1627 else if (entry_a->ts_nsec < entry_b->ts_nsec)
1633 static inline const char *
1634 topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type)
1636 if (type == DRM_DP_MST_TOPOLOGY_REF_GET)
1643 __dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history,
1644 void *ptr, const char *type_str)
1646 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1647 char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1656 /* First, sort the list so that it goes from oldest to newest
1659 sort(history->entries, history->len, sizeof(*history->entries),
1660 topology_ref_history_cmp, NULL);
1662 drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n",
1665 for (i = 0; i < history->len; i++) {
1666 const struct drm_dp_mst_topology_ref_entry *entry =
1667 &history->entries[i];
1670 u64 ts_nsec = entry->ts_nsec;
1671 u32 rem_nsec = do_div(ts_nsec, 1000000000);
1673 nr_entries = stack_depot_fetch(entry->backtrace, &entries);
1674 stack_trace_snprint(buf, PAGE_SIZE, entries, nr_entries, 4);
1676 drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s",
1678 topology_ref_type_to_str(entry->type),
1679 ts_nsec, rem_nsec / 1000, buf);
1682 /* Now free the history, since this is the only time we expose it */
1683 kfree(history->entries);
1688 static __always_inline void
1689 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb)
1691 __dump_topology_ref_history(&mstb->topology_ref_history, mstb,
1695 static __always_inline void
1696 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port)
1698 __dump_topology_ref_history(&port->topology_ref_history, port,
1702 static __always_inline void
1703 save_mstb_topology_ref(struct drm_dp_mst_branch *mstb,
1704 enum drm_dp_mst_topology_ref_type type)
1706 __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type);
1709 static __always_inline void
1710 save_port_topology_ref(struct drm_dp_mst_port *port,
1711 enum drm_dp_mst_topology_ref_type type)
1713 __topology_ref_save(port->mgr, &port->topology_ref_history, type);
1717 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr)
1719 mutex_lock(&mgr->topology_ref_history_lock);
1723 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr)
1725 mutex_unlock(&mgr->topology_ref_history_lock);
1729 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {}
1731 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {}
1733 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {}
1735 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {}
1736 #define save_mstb_topology_ref(mstb, type)
1737 #define save_port_topology_ref(port, type)
1740 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
1742 struct drm_dp_mst_branch *mstb =
1743 container_of(kref, struct drm_dp_mst_branch, topology_kref);
1744 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1746 drm_dp_mst_dump_mstb_topology_history(mstb);
1748 INIT_LIST_HEAD(&mstb->destroy_next);
1751 * This can get called under mgr->mutex, so we need to perform the
1752 * actual destruction of the mstb in another worker
1754 mutex_lock(&mgr->delayed_destroy_lock);
1755 list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list);
1756 mutex_unlock(&mgr->delayed_destroy_lock);
1757 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1761 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1762 * branch device unless it's zero
1763 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
1765 * Attempts to grab a topology reference to @mstb, if it hasn't yet been
1766 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
1767 * reached 0). Holding a topology reference implies that a malloc reference
1768 * will be held to @mstb as long as the user holds the topology reference.
1770 * Care should be taken to ensure that the user has at least one malloc
1771 * reference to @mstb. If you already have a topology reference to @mstb, you
1772 * should use drm_dp_mst_topology_get_mstb() instead.
1775 * drm_dp_mst_topology_get_mstb()
1776 * drm_dp_mst_topology_put_mstb()
1779 * * 1: A topology reference was grabbed successfully
1780 * * 0: @port is no longer in the topology, no reference was grabbed
1782 static int __must_check
1783 drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
1787 topology_ref_history_lock(mstb->mgr);
1788 ret = kref_get_unless_zero(&mstb->topology_kref);
1790 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1791 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1794 topology_ref_history_unlock(mstb->mgr);
1800 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
1802 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
1804 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or
1805 * not it's already reached 0. This is only valid to use in scenarios where
1806 * you are already guaranteed to have at least one active topology reference
1807 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
1810 * drm_dp_mst_topology_try_get_mstb()
1811 * drm_dp_mst_topology_put_mstb()
1813 static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
1815 topology_ref_history_lock(mstb->mgr);
1817 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1818 WARN_ON(kref_read(&mstb->topology_kref) == 0);
1819 kref_get(&mstb->topology_kref);
1820 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1822 topology_ref_history_unlock(mstb->mgr);
1826 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
1828 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from
1830 * Releases a topology reference from @mstb by decrementing
1831 * &drm_dp_mst_branch.topology_kref.
1834 * drm_dp_mst_topology_try_get_mstb()
1835 * drm_dp_mst_topology_get_mstb()
1838 drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
1840 topology_ref_history_lock(mstb->mgr);
1842 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref) - 1);
1843 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT);
1845 topology_ref_history_unlock(mstb->mgr);
1846 kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
1849 static void drm_dp_destroy_port(struct kref *kref)
1851 struct drm_dp_mst_port *port =
1852 container_of(kref, struct drm_dp_mst_port, topology_kref);
1853 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1855 drm_dp_mst_dump_port_topology_history(port);
1857 /* There's nothing that needs locking to destroy an input port yet */
1859 drm_dp_mst_put_port_malloc(port);
1863 kfree(port->cached_edid);
1866 * we can't destroy the connector here, as we might be holding the
1867 * mode_config.mutex from an EDID retrieval
1869 mutex_lock(&mgr->delayed_destroy_lock);
1870 list_add(&port->next, &mgr->destroy_port_list);
1871 mutex_unlock(&mgr->delayed_destroy_lock);
1872 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work);
1876 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
1877 * port unless it's zero
1878 * @port: &struct drm_dp_mst_port to increment the topology refcount of
1880 * Attempts to grab a topology reference to @port, if it hasn't yet been
1881 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
1882 * 0). Holding a topology reference implies that a malloc reference will be
1883 * held to @port as long as the user holds the topology reference.
1885 * Care should be taken to ensure that the user has at least one malloc
1886 * reference to @port. If you already have a topology reference to @port, you
1887 * should use drm_dp_mst_topology_get_port() instead.
1890 * drm_dp_mst_topology_get_port()
1891 * drm_dp_mst_topology_put_port()
1894 * * 1: A topology reference was grabbed successfully
1895 * * 0: @port is no longer in the topology, no reference was grabbed
1897 static int __must_check
1898 drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
1902 topology_ref_history_lock(port->mgr);
1903 ret = kref_get_unless_zero(&port->topology_kref);
1905 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref));
1906 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1909 topology_ref_history_unlock(port->mgr);
1914 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
1915 * @port: The &struct drm_dp_mst_port to increment the topology refcount of
1917 * Increments &drm_dp_mst_port.topology_refcount without checking whether or
1918 * not it's already reached 0. This is only valid to use in scenarios where
1919 * you are already guaranteed to have at least one active topology reference
1920 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
1923 * drm_dp_mst_topology_try_get_port()
1924 * drm_dp_mst_topology_put_port()
1926 static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
1928 topology_ref_history_lock(port->mgr);
1930 WARN_ON(kref_read(&port->topology_kref) == 0);
1931 kref_get(&port->topology_kref);
1932 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref));
1933 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1935 topology_ref_history_unlock(port->mgr);
1939 * drm_dp_mst_topology_put_port() - release a topology reference to a port
1940 * @port: The &struct drm_dp_mst_port to release the topology reference from
1942 * Releases a topology reference from @port by decrementing
1943 * &drm_dp_mst_port.topology_kref.
1946 * drm_dp_mst_topology_try_get_port()
1947 * drm_dp_mst_topology_get_port()
1949 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
1951 topology_ref_history_lock(port->mgr);
1953 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref) - 1);
1954 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT);
1956 topology_ref_history_unlock(port->mgr);
1957 kref_put(&port->topology_kref, drm_dp_destroy_port);
1960 static struct drm_dp_mst_branch *
1961 drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
1962 struct drm_dp_mst_branch *to_find)
1964 struct drm_dp_mst_port *port;
1965 struct drm_dp_mst_branch *rmstb;
1967 if (to_find == mstb)
1970 list_for_each_entry(port, &mstb->ports, next) {
1972 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1973 port->mstb, to_find);
1981 static struct drm_dp_mst_branch *
1982 drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
1983 struct drm_dp_mst_branch *mstb)
1985 struct drm_dp_mst_branch *rmstb = NULL;
1987 mutex_lock(&mgr->lock);
1988 if (mgr->mst_primary) {
1989 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1990 mgr->mst_primary, mstb);
1992 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
1995 mutex_unlock(&mgr->lock);
1999 static struct drm_dp_mst_port *
2000 drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
2001 struct drm_dp_mst_port *to_find)
2003 struct drm_dp_mst_port *port, *mport;
2005 list_for_each_entry(port, &mstb->ports, next) {
2006 if (port == to_find)
2010 mport = drm_dp_mst_topology_get_port_validated_locked(
2011 port->mstb, to_find);
2019 static struct drm_dp_mst_port *
2020 drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
2021 struct drm_dp_mst_port *port)
2023 struct drm_dp_mst_port *rport = NULL;
2025 mutex_lock(&mgr->lock);
2026 if (mgr->mst_primary) {
2027 rport = drm_dp_mst_topology_get_port_validated_locked(
2028 mgr->mst_primary, port);
2030 if (rport && !drm_dp_mst_topology_try_get_port(rport))
2033 mutex_unlock(&mgr->lock);
2037 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
2039 struct drm_dp_mst_port *port;
2042 list_for_each_entry(port, &mstb->ports, next) {
2043 if (port->port_num == port_num) {
2044 ret = drm_dp_mst_topology_try_get_port(port);
2045 return ret ? port : NULL;
2053 * calculate a new RAD for this MST branch device
2054 * if parent has an LCT of 2 then it has 1 nibble of RAD,
2055 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
2057 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
2060 int parent_lct = port->parent->lct;
2062 int idx = (parent_lct - 1) / 2;
2064 if (parent_lct > 1) {
2065 memcpy(rad, port->parent->rad, idx + 1);
2066 shift = (parent_lct % 2) ? 4 : 0;
2070 rad[idx] |= port->port_num << shift;
2071 return parent_lct + 1;
2074 static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs)
2077 case DP_PEER_DEVICE_DP_LEGACY_CONV:
2078 case DP_PEER_DEVICE_SST_SINK:
2080 case DP_PEER_DEVICE_MST_BRANCHING:
2081 /* For sst branch device */
2091 drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt,
2094 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2095 struct drm_dp_mst_branch *mstb;
2099 if (port->pdt == new_pdt && port->mcs == new_mcs)
2102 /* Teardown the old pdt, if there is one */
2103 if (port->pdt != DP_PEER_DEVICE_NONE) {
2104 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2106 * If the new PDT would also have an i2c bus,
2107 * don't bother with reregistering it
2109 if (new_pdt != DP_PEER_DEVICE_NONE &&
2110 drm_dp_mst_is_end_device(new_pdt, new_mcs)) {
2111 port->pdt = new_pdt;
2112 port->mcs = new_mcs;
2116 /* remove i2c over sideband */
2117 drm_dp_mst_unregister_i2c_bus(port);
2119 mutex_lock(&mgr->lock);
2120 drm_dp_mst_topology_put_mstb(port->mstb);
2122 mutex_unlock(&mgr->lock);
2126 port->pdt = new_pdt;
2127 port->mcs = new_mcs;
2129 if (port->pdt != DP_PEER_DEVICE_NONE) {
2130 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
2131 /* add i2c over sideband */
2132 ret = drm_dp_mst_register_i2c_bus(port);
2134 lct = drm_dp_calculate_rad(port, rad);
2135 mstb = drm_dp_add_mst_branch_device(lct, rad);
2138 drm_err(mgr->dev, "Failed to create MSTB for port %p", port);
2142 mutex_lock(&mgr->lock);
2144 mstb->mgr = port->mgr;
2145 mstb->port_parent = port;
2148 * Make sure this port's memory allocation stays
2149 * around until its child MSTB releases it
2151 drm_dp_mst_get_port_malloc(port);
2152 mutex_unlock(&mgr->lock);
2154 /* And make sure we send a link address for this */
2161 port->pdt = DP_PEER_DEVICE_NONE;
2166 * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
2167 * @aux: Fake sideband AUX CH
2168 * @offset: address of the (first) register to read
2169 * @buffer: buffer to store the register values
2170 * @size: number of bytes in @buffer
2172 * Performs the same functionality for remote devices via
2173 * sideband messaging as drm_dp_dpcd_read() does for local
2174 * devices via actual AUX CH.
2176 * Return: Number of bytes read, or negative error code on failure.
2178 ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
2179 unsigned int offset, void *buffer, size_t size)
2181 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2184 return drm_dp_send_dpcd_read(port->mgr, port,
2185 offset, size, buffer);
2189 * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
2190 * @aux: Fake sideband AUX CH
2191 * @offset: address of the (first) register to write
2192 * @buffer: buffer containing the values to write
2193 * @size: number of bytes in @buffer
2195 * Performs the same functionality for remote devices via
2196 * sideband messaging as drm_dp_dpcd_write() does for local
2197 * devices via actual AUX CH.
2199 * Return: number of bytes written on success, negative error code on failure.
2201 ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
2202 unsigned int offset, void *buffer, size_t size)
2204 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2207 return drm_dp_send_dpcd_write(port->mgr, port,
2208 offset, size, buffer);
2211 static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
2215 memcpy(mstb->guid, guid, 16);
2217 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
2218 if (mstb->port_parent) {
2219 ret = drm_dp_send_dpcd_write(mstb->mgr,
2221 DP_GUID, 16, mstb->guid);
2223 ret = drm_dp_dpcd_write(mstb->mgr->aux,
2224 DP_GUID, mstb->guid, 16);
2228 if (ret < 16 && ret > 0)
2231 return ret == 16 ? 0 : ret;
2234 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
2237 size_t proppath_size)
2242 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
2243 for (i = 0; i < (mstb->lct - 1); i++) {
2244 int shift = (i % 2) ? 0 : 4;
2245 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
2247 snprintf(temp, sizeof(temp), "-%d", port_num);
2248 strlcat(proppath, temp, proppath_size);
2250 snprintf(temp, sizeof(temp), "-%d", pnum);
2251 strlcat(proppath, temp, proppath_size);
2255 * drm_dp_mst_connector_late_register() - Late MST connector registration
2256 * @connector: The MST connector
2257 * @port: The MST port for this connector
2259 * Helper to register the remote aux device for this MST port. Drivers should
2260 * call this from their mst connector's late_register hook to enable MST aux
2263 * Return: 0 on success, negative error code on failure.
2265 int drm_dp_mst_connector_late_register(struct drm_connector *connector,
2266 struct drm_dp_mst_port *port)
2268 drm_dbg_kms(port->mgr->dev, "registering %s remote bus for %s\n",
2269 port->aux.name, connector->kdev->kobj.name);
2271 port->aux.dev = connector->kdev;
2272 return drm_dp_aux_register_devnode(&port->aux);
2274 EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
2277 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
2278 * @connector: The MST connector
2279 * @port: The MST port for this connector
2281 * Helper to unregister the remote aux device for this MST port, registered by
2282 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst
2283 * connector's early_unregister hook.
2285 void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
2286 struct drm_dp_mst_port *port)
2288 drm_dbg_kms(port->mgr->dev, "unregistering %s remote bus for %s\n",
2289 port->aux.name, connector->kdev->kobj.name);
2290 drm_dp_aux_unregister_devnode(&port->aux);
2292 EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
2295 drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
2296 struct drm_dp_mst_port *port)
2298 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2302 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
2303 port->connector = mgr->cbs->add_connector(mgr, port, proppath);
2304 if (!port->connector) {
2309 if (port->pdt != DP_PEER_DEVICE_NONE &&
2310 drm_dp_mst_is_end_device(port->pdt, port->mcs) &&
2311 port->port_num >= DP_MST_LOGICAL_PORT_0)
2312 port->cached_edid = drm_get_edid(port->connector,
2315 drm_connector_register(port->connector);
2319 drm_err(mgr->dev, "Failed to create connector for port %p: %d\n", port, ret);
2323 * Drop a topology reference, and unlink the port from the in-memory topology
2327 drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr,
2328 struct drm_dp_mst_port *port)
2330 mutex_lock(&mgr->lock);
2331 port->parent->num_ports--;
2332 list_del(&port->next);
2333 mutex_unlock(&mgr->lock);
2334 drm_dp_mst_topology_put_port(port);
2337 static struct drm_dp_mst_port *
2338 drm_dp_mst_add_port(struct drm_device *dev,
2339 struct drm_dp_mst_topology_mgr *mgr,
2340 struct drm_dp_mst_branch *mstb, u8 port_number)
2342 struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
2347 kref_init(&port->topology_kref);
2348 kref_init(&port->malloc_kref);
2349 port->parent = mstb;
2350 port->port_num = port_number;
2352 port->aux.name = "DPMST";
2353 port->aux.dev = dev->dev;
2354 port->aux.is_remote = true;
2356 /* initialize the MST downstream port's AUX crc work queue */
2357 port->aux.drm_dev = dev;
2358 drm_dp_remote_aux_init(&port->aux);
2361 * Make sure the memory allocation for our parent branch stays
2362 * around until our own memory allocation is released
2364 drm_dp_mst_get_mstb_malloc(mstb);
2370 drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
2371 struct drm_device *dev,
2372 struct drm_dp_link_addr_reply_port *port_msg)
2374 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2375 struct drm_dp_mst_port *port;
2376 int old_ddps = 0, ret;
2377 u8 new_pdt = DP_PEER_DEVICE_NONE;
2379 bool created = false, send_link_addr = false, changed = false;
2381 port = drm_dp_get_port(mstb, port_msg->port_number);
2383 port = drm_dp_mst_add_port(dev, mgr, mstb,
2384 port_msg->port_number);
2389 } else if (!port->input && port_msg->input_port && port->connector) {
2390 /* Since port->connector can't be changed here, we create a
2391 * new port if input_port changes from 0 to 1
2393 drm_dp_mst_topology_unlink_port(mgr, port);
2394 drm_dp_mst_topology_put_port(port);
2395 port = drm_dp_mst_add_port(dev, mgr, mstb,
2396 port_msg->port_number);
2401 } else if (port->input && !port_msg->input_port) {
2403 } else if (port->connector) {
2404 /* We're updating a port that's exposed to userspace, so do it
2407 drm_modeset_lock(&mgr->base.lock, NULL);
2409 old_ddps = port->ddps;
2410 changed = port->ddps != port_msg->ddps ||
2412 (port->ldps != port_msg->legacy_device_plug_status ||
2413 port->dpcd_rev != port_msg->dpcd_revision ||
2414 port->mcs != port_msg->mcs ||
2415 port->pdt != port_msg->peer_device_type ||
2416 port->num_sdp_stream_sinks !=
2417 port_msg->num_sdp_stream_sinks));
2420 port->input = port_msg->input_port;
2422 new_pdt = port_msg->peer_device_type;
2423 new_mcs = port_msg->mcs;
2424 port->ddps = port_msg->ddps;
2425 port->ldps = port_msg->legacy_device_plug_status;
2426 port->dpcd_rev = port_msg->dpcd_revision;
2427 port->num_sdp_streams = port_msg->num_sdp_streams;
2428 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
2430 /* manage mstb port lists with mgr lock - take a reference
2433 mutex_lock(&mgr->lock);
2434 drm_dp_mst_topology_get_port(port);
2435 list_add(&port->next, &mstb->ports);
2437 mutex_unlock(&mgr->lock);
2441 * Reprobe PBN caps on both hotplug, and when re-probing the link
2442 * for our parent mstb
2444 if (old_ddps != port->ddps || !created) {
2445 if (port->ddps && !port->input) {
2446 ret = drm_dp_send_enum_path_resources(mgr, mstb,
2455 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs);
2457 send_link_addr = true;
2458 } else if (ret < 0) {
2459 drm_err(dev, "Failed to change PDT on port %p: %d\n", port, ret);
2464 * If this port wasn't just created, then we're reprobing because
2465 * we're coming out of suspend. In this case, always resend the link
2466 * address if there's an MSTB on this port
2468 if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
2470 send_link_addr = true;
2472 if (port->connector)
2473 drm_modeset_unlock(&mgr->base.lock);
2474 else if (!port->input)
2475 drm_dp_mst_port_add_connector(mstb, port);
2477 if (send_link_addr && port->mstb) {
2478 ret = drm_dp_send_link_address(mgr, port->mstb);
2479 if (ret == 1) /* MSTB below us changed */
2485 /* put reference to this port */
2486 drm_dp_mst_topology_put_port(port);
2490 drm_dp_mst_topology_unlink_port(mgr, port);
2491 if (port->connector)
2492 drm_modeset_unlock(&mgr->base.lock);
2494 drm_dp_mst_topology_put_port(port);
2499 drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
2500 struct drm_dp_connection_status_notify *conn_stat)
2502 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2503 struct drm_dp_mst_port *port;
2504 int old_ddps, old_input, ret, i;
2507 bool dowork = false, create_connector = false;
2509 port = drm_dp_get_port(mstb, conn_stat->port_number);
2513 if (port->connector) {
2514 if (!port->input && conn_stat->input_port) {
2516 * We can't remove a connector from an already exposed
2517 * port, so just throw the port out and make sure we
2518 * reprobe the link address of it's parent MSTB
2520 drm_dp_mst_topology_unlink_port(mgr, port);
2521 mstb->link_address_sent = false;
2526 /* Locking is only needed if the port's exposed to userspace */
2527 drm_modeset_lock(&mgr->base.lock, NULL);
2528 } else if (port->input && !conn_stat->input_port) {
2529 create_connector = true;
2530 /* Reprobe link address so we get num_sdp_streams */
2531 mstb->link_address_sent = false;
2535 old_ddps = port->ddps;
2536 old_input = port->input;
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 (!old_input && old_ddps != port->ddps && !port->ddps) {
2559 for (i = 0; i < mgr->max_payloads; i++) {
2560 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
2561 struct drm_dp_mst_port *port_validated;
2567 container_of(vcpi, struct drm_dp_mst_port, vcpi);
2569 drm_dp_mst_topology_get_port_validated(mgr, port_validated);
2570 if (!port_validated) {
2571 mutex_lock(&mgr->payload_lock);
2572 vcpi->num_slots = 0;
2573 mutex_unlock(&mgr->payload_lock);
2575 drm_dp_mst_topology_put_port(port_validated);
2580 if (port->connector)
2581 drm_modeset_unlock(&mgr->base.lock);
2582 else if (create_connector)
2583 drm_dp_mst_port_add_connector(mstb, port);
2586 drm_dp_mst_topology_put_port(port);
2588 queue_work(system_long_wq, &mstb->mgr->work);
2591 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
2594 struct drm_dp_mst_branch *mstb;
2595 struct drm_dp_mst_port *port;
2597 /* find the port by iterating down */
2599 mutex_lock(&mgr->lock);
2600 mstb = mgr->mst_primary;
2605 for (i = 0; i < lct - 1; i++) {
2606 int shift = (i % 2) ? 0 : 4;
2607 int port_num = (rad[i / 2] >> shift) & 0xf;
2609 list_for_each_entry(port, &mstb->ports, next) {
2610 if (port->port_num == port_num) {
2614 "failed to lookup MSTB with lct %d, rad %02x\n",
2623 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2627 mutex_unlock(&mgr->lock);
2631 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
2632 struct drm_dp_mst_branch *mstb,
2633 const uint8_t *guid)
2635 struct drm_dp_mst_branch *found_mstb;
2636 struct drm_dp_mst_port *port;
2638 if (memcmp(mstb->guid, guid, 16) == 0)
2642 list_for_each_entry(port, &mstb->ports, next) {
2646 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
2655 static struct drm_dp_mst_branch *
2656 drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
2657 const uint8_t *guid)
2659 struct drm_dp_mst_branch *mstb;
2662 /* find the port by iterating down */
2663 mutex_lock(&mgr->lock);
2665 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
2667 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2672 mutex_unlock(&mgr->lock);
2676 static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2677 struct drm_dp_mst_branch *mstb)
2679 struct drm_dp_mst_port *port;
2681 bool changed = false;
2683 if (!mstb->link_address_sent) {
2684 ret = drm_dp_send_link_address(mgr, mstb);
2691 list_for_each_entry(port, &mstb->ports, next) {
2692 struct drm_dp_mst_branch *mstb_child = NULL;
2694 if (port->input || !port->ddps)
2698 mstb_child = drm_dp_mst_topology_get_mstb_validated(
2702 ret = drm_dp_check_and_send_link_address(mgr,
2704 drm_dp_mst_topology_put_mstb(mstb_child);
2715 static void drm_dp_mst_link_probe_work(struct work_struct *work)
2717 struct drm_dp_mst_topology_mgr *mgr =
2718 container_of(work, struct drm_dp_mst_topology_mgr, work);
2719 struct drm_device *dev = mgr->dev;
2720 struct drm_dp_mst_branch *mstb;
2722 bool clear_payload_id_table;
2724 mutex_lock(&mgr->probe_lock);
2726 mutex_lock(&mgr->lock);
2727 clear_payload_id_table = !mgr->payload_id_table_cleared;
2728 mgr->payload_id_table_cleared = true;
2730 mstb = mgr->mst_primary;
2732 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2736 mutex_unlock(&mgr->lock);
2738 mutex_unlock(&mgr->probe_lock);
2743 * Certain branch devices seem to incorrectly report an available_pbn
2744 * of 0 on downstream sinks, even after clearing the
2745 * DP_PAYLOAD_ALLOCATE_* registers in
2746 * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
2747 * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
2748 * things work again.
2750 if (clear_payload_id_table) {
2751 drm_dbg_kms(dev, "Clearing payload ID table\n");
2752 drm_dp_send_clear_payload_id_table(mgr, mstb);
2755 ret = drm_dp_check_and_send_link_address(mgr, mstb);
2756 drm_dp_mst_topology_put_mstb(mstb);
2758 mutex_unlock(&mgr->probe_lock);
2760 drm_kms_helper_hotplug_event(dev);
2763 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
2768 if (memchr_inv(guid, 0, 16))
2771 salt = get_jiffies_64();
2773 memcpy(&guid[0], &salt, sizeof(u64));
2774 memcpy(&guid[8], &salt, sizeof(u64));
2779 static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg,
2780 u8 port_num, u32 offset, u8 num_bytes)
2782 struct drm_dp_sideband_msg_req_body req;
2784 req.req_type = DP_REMOTE_DPCD_READ;
2785 req.u.dpcd_read.port_number = port_num;
2786 req.u.dpcd_read.dpcd_address = offset;
2787 req.u.dpcd_read.num_bytes = num_bytes;
2788 drm_dp_encode_sideband_req(&req, msg);
2791 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
2792 bool up, u8 *msg, int len)
2795 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
2796 int tosend, total, offset;
2803 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
2805 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
2808 if (ret != tosend) {
2809 if (ret == -EIO && retries < 5) {
2813 drm_dbg_kms(mgr->dev, "failed to dpcd write %d %d\n", tosend, ret);
2819 } while (total > 0);
2823 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
2824 struct drm_dp_sideband_msg_tx *txmsg)
2826 struct drm_dp_mst_branch *mstb = txmsg->dst;
2829 req_type = txmsg->msg[0] & 0x7f;
2830 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
2831 req_type == DP_RESOURCE_STATUS_NOTIFY ||
2832 req_type == DP_CLEAR_PAYLOAD_ID_TABLE)
2836 hdr->path_msg = txmsg->path_msg;
2837 if (hdr->broadcast) {
2841 hdr->lct = mstb->lct;
2842 hdr->lcr = mstb->lct - 1;
2845 memcpy(hdr->rad, mstb->rad, hdr->lct / 2);
2850 * process a single block of the next message in the sideband queue
2852 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2853 struct drm_dp_sideband_msg_tx *txmsg,
2857 struct drm_dp_sideband_msg_hdr hdr;
2858 int len, space, idx, tosend;
2861 if (txmsg->state == DRM_DP_SIDEBAND_TX_SENT)
2864 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
2866 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED)
2867 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
2869 /* make hdr from dst mst */
2870 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
2874 /* amount left to send in this message */
2875 len = txmsg->cur_len - txmsg->cur_offset;
2877 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
2878 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
2880 tosend = min(len, space);
2881 if (len == txmsg->cur_len)
2887 hdr.msg_len = tosend + 1;
2888 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
2889 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
2890 /* add crc at end */
2891 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
2894 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
2895 if (unlikely(ret) && drm_debug_enabled(DRM_UT_DP)) {
2896 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2898 drm_printf(&p, "sideband msg failed to send\n");
2899 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2903 txmsg->cur_offset += tosend;
2904 if (txmsg->cur_offset == txmsg->cur_len) {
2905 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
2911 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
2913 struct drm_dp_sideband_msg_tx *txmsg;
2916 WARN_ON(!mutex_is_locked(&mgr->qlock));
2918 /* construct a chunk from the first msg in the tx_msg queue */
2919 if (list_empty(&mgr->tx_msg_downq))
2922 txmsg = list_first_entry(&mgr->tx_msg_downq,
2923 struct drm_dp_sideband_msg_tx, next);
2924 ret = process_single_tx_qlock(mgr, txmsg, false);
2926 drm_dbg_kms(mgr->dev, "failed to send msg in q %d\n", ret);
2927 list_del(&txmsg->next);
2928 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
2929 wake_up_all(&mgr->tx_waitq);
2933 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
2934 struct drm_dp_sideband_msg_tx *txmsg)
2936 mutex_lock(&mgr->qlock);
2937 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
2939 if (drm_debug_enabled(DRM_UT_DP)) {
2940 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2942 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2945 if (list_is_singular(&mgr->tx_msg_downq))
2946 process_single_down_tx_qlock(mgr);
2947 mutex_unlock(&mgr->qlock);
2951 drm_dp_dump_link_address(const struct drm_dp_mst_topology_mgr *mgr,
2952 struct drm_dp_link_address_ack_reply *reply)
2954 struct drm_dp_link_addr_reply_port *port_reply;
2957 for (i = 0; i < reply->nports; i++) {
2958 port_reply = &reply->ports[i];
2959 drm_dbg_kms(mgr->dev,
2960 "port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n",
2962 port_reply->input_port,
2963 port_reply->peer_device_type,
2964 port_reply->port_number,
2965 port_reply->dpcd_revision,
2968 port_reply->legacy_device_plug_status,
2969 port_reply->num_sdp_streams,
2970 port_reply->num_sdp_stream_sinks);
2974 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2975 struct drm_dp_mst_branch *mstb)
2977 struct drm_dp_sideband_msg_tx *txmsg;
2978 struct drm_dp_link_address_ack_reply *reply;
2979 struct drm_dp_mst_port *port, *tmp;
2980 int i, ret, port_mask = 0;
2981 bool changed = false;
2983 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2988 build_link_address(txmsg);
2990 mstb->link_address_sent = true;
2991 drm_dp_queue_down_tx(mgr, txmsg);
2993 /* FIXME: Actually do some real error handling here */
2994 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2996 drm_err(mgr->dev, "Sending link address failed with %d\n", ret);
2999 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3000 drm_err(mgr->dev, "link address NAK received\n");
3005 reply = &txmsg->reply.u.link_addr;
3006 drm_dbg_kms(mgr->dev, "link address reply: %d\n", reply->nports);
3007 drm_dp_dump_link_address(mgr, reply);
3009 ret = drm_dp_check_mstb_guid(mstb, reply->guid);
3013 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf));
3014 drm_err(mgr->dev, "GUID check on %s failed: %d\n", buf, ret);
3018 for (i = 0; i < reply->nports; i++) {
3019 port_mask |= BIT(reply->ports[i].port_number);
3020 ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev,
3028 /* Prune any ports that are currently a part of mstb in our in-memory
3029 * topology, but were not seen in this link address. Usually this
3030 * means that they were removed while the topology was out of sync,
3031 * e.g. during suspend/resume
3033 mutex_lock(&mgr->lock);
3034 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
3035 if (port_mask & BIT(port->port_num))
3038 drm_dbg_kms(mgr->dev, "port %d was not in link address, removing\n",
3040 list_del(&port->next);
3041 drm_dp_mst_topology_put_port(port);
3044 mutex_unlock(&mgr->lock);
3048 mstb->link_address_sent = false;
3050 return ret < 0 ? ret : changed;
3054 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
3055 struct drm_dp_mst_branch *mstb)
3057 struct drm_dp_sideband_msg_tx *txmsg;
3060 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3065 build_clear_payload_id_table(txmsg);
3067 drm_dp_queue_down_tx(mgr, txmsg);
3069 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3070 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3071 drm_dbg_kms(mgr->dev, "clear payload table id nak received\n");
3077 drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
3078 struct drm_dp_mst_branch *mstb,
3079 struct drm_dp_mst_port *port)
3081 struct drm_dp_enum_path_resources_ack_reply *path_res;
3082 struct drm_dp_sideband_msg_tx *txmsg;
3085 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3090 build_enum_path_resources(txmsg, port->port_num);
3092 drm_dp_queue_down_tx(mgr, txmsg);
3094 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3097 path_res = &txmsg->reply.u.path_resources;
3099 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3100 drm_dbg_kms(mgr->dev, "enum path resources nak received\n");
3102 if (port->port_num != path_res->port_number)
3103 DRM_ERROR("got incorrect port in response\n");
3105 drm_dbg_kms(mgr->dev, "enum path resources %d: %d %d\n",
3106 path_res->port_number,
3107 path_res->full_payload_bw_number,
3108 path_res->avail_payload_bw_number);
3111 * If something changed, make sure we send a
3114 if (port->full_pbn != path_res->full_payload_bw_number ||
3115 port->fec_capable != path_res->fec_capable)
3118 port->full_pbn = path_res->full_payload_bw_number;
3119 port->fec_capable = path_res->fec_capable;
3127 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
3129 if (!mstb->port_parent)
3132 if (mstb->port_parent->mstb != mstb)
3133 return mstb->port_parent;
3135 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
3139 * Searches upwards in the topology starting from mstb to try to find the
3140 * closest available parent of mstb that's still connected to the rest of the
3141 * topology. This can be used in order to perform operations like releasing
3142 * payloads, where the branch device which owned the payload may no longer be
3143 * around and thus would require that the payload on the last living relative
3146 static struct drm_dp_mst_branch *
3147 drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
3148 struct drm_dp_mst_branch *mstb,
3151 struct drm_dp_mst_branch *rmstb = NULL;
3152 struct drm_dp_mst_port *found_port;
3154 mutex_lock(&mgr->lock);
3155 if (!mgr->mst_primary)
3159 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
3163 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
3164 rmstb = found_port->parent;
3165 *port_num = found_port->port_num;
3167 /* Search again, starting from this parent */
3168 mstb = found_port->parent;
3172 mutex_unlock(&mgr->lock);
3176 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
3177 struct drm_dp_mst_port *port,
3181 struct drm_dp_sideband_msg_tx *txmsg;
3182 struct drm_dp_mst_branch *mstb;
3184 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
3187 port_num = port->port_num;
3188 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3190 mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
3198 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3204 for (i = 0; i < port->num_sdp_streams; i++)
3208 build_allocate_payload(txmsg, port_num,
3210 pbn, port->num_sdp_streams, sinks);
3212 drm_dp_queue_down_tx(mgr, txmsg);
3215 * FIXME: there is a small chance that between getting the last
3216 * connected mstb and sending the payload message, the last connected
3217 * mstb could also be removed from the topology. In the future, this
3218 * needs to be fixed by restarting the
3219 * drm_dp_get_last_connected_port_and_mstb() search in the event of a
3220 * timeout if the topology is still connected to the system.
3222 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3224 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3231 drm_dp_mst_topology_put_mstb(mstb);
3235 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
3236 struct drm_dp_mst_port *port, bool power_up)
3238 struct drm_dp_sideband_msg_tx *txmsg;
3241 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3245 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3247 drm_dp_mst_topology_put_port(port);
3251 txmsg->dst = port->parent;
3252 build_power_updown_phy(txmsg, port->port_num, power_up);
3253 drm_dp_queue_down_tx(mgr, txmsg);
3255 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
3257 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3263 drm_dp_mst_topology_put_port(port);
3267 EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
3269 int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr,
3270 struct drm_dp_mst_port *port,
3271 struct drm_dp_query_stream_enc_status_ack_reply *status)
3273 struct drm_dp_sideband_msg_tx *txmsg;
3277 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3281 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3287 get_random_bytes(nonce, sizeof(nonce));
3290 * "Source device targets the QUERY_STREAM_ENCRYPTION_STATUS message
3291 * transaction at the MST Branch device directly connected to the
3294 txmsg->dst = mgr->mst_primary;
3296 build_query_stream_enc_status(txmsg, port->vcpi.vcpi, nonce);
3298 drm_dp_queue_down_tx(mgr, txmsg);
3300 ret = drm_dp_mst_wait_tx_reply(mgr->mst_primary, txmsg);
3303 } else if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
3304 drm_dbg_kms(mgr->dev, "query encryption status nak received\n");
3310 memcpy(status, &txmsg->reply.u.enc_status, sizeof(*status));
3313 drm_dp_mst_topology_put_port(port);
3318 EXPORT_SYMBOL(drm_dp_send_query_stream_enc_status);
3320 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3322 struct drm_dp_payload *payload)
3326 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
3328 payload->payload_state = 0;
3331 payload->payload_state = DP_PAYLOAD_LOCAL;
3335 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3336 struct drm_dp_mst_port *port,
3338 struct drm_dp_payload *payload)
3342 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
3345 payload->payload_state = DP_PAYLOAD_REMOTE;
3349 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3350 struct drm_dp_mst_port *port,
3352 struct drm_dp_payload *payload)
3354 drm_dbg_kms(mgr->dev, "\n");
3355 /* it's okay for these to fail */
3357 drm_dp_payload_send_msg(mgr, port, id, 0);
3360 drm_dp_dpcd_write_payload(mgr, id, payload);
3361 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
3365 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3367 struct drm_dp_payload *payload)
3369 payload->payload_state = 0;
3374 * drm_dp_update_payload_part1() - Execute payload update part 1
3375 * @mgr: manager to use.
3377 * This iterates over all proposed virtual channels, and tries to
3378 * allocate space in the link for them. For 0->slots transitions,
3379 * this step just writes the VCPI to the MST device. For slots->0
3380 * transitions, this writes the updated VCPIs and removes the
3381 * remote VC payloads.
3383 * after calling this the driver should generate ACT and payload
3386 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
3388 struct drm_dp_payload req_payload;
3389 struct drm_dp_mst_port *port;
3393 mutex_lock(&mgr->payload_lock);
3394 for (i = 0; i < mgr->max_payloads; i++) {
3395 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
3396 struct drm_dp_payload *payload = &mgr->payloads[i];
3397 bool put_port = false;
3399 /* solve the current payloads - compare to the hw ones
3400 - update the hw view */
3401 req_payload.start_slot = cur_slots;
3403 port = container_of(vcpi, struct drm_dp_mst_port,
3406 /* Validated ports don't matter if we're releasing
3409 if (vcpi->num_slots) {
3410 port = drm_dp_mst_topology_get_port_validated(
3413 mutex_unlock(&mgr->payload_lock);
3419 req_payload.num_slots = vcpi->num_slots;
3420 req_payload.vcpi = vcpi->vcpi;
3423 req_payload.num_slots = 0;
3426 payload->start_slot = req_payload.start_slot;
3427 /* work out what is required to happen with this payload */
3428 if (payload->num_slots != req_payload.num_slots) {
3430 /* need to push an update for this payload */
3431 if (req_payload.num_slots) {
3432 drm_dp_create_payload_step1(mgr, vcpi->vcpi,
3434 payload->num_slots = req_payload.num_slots;
3435 payload->vcpi = req_payload.vcpi;
3437 } else if (payload->num_slots) {
3438 payload->num_slots = 0;
3439 drm_dp_destroy_payload_step1(mgr, port,
3442 req_payload.payload_state =
3443 payload->payload_state;
3444 payload->start_slot = 0;
3446 payload->payload_state = req_payload.payload_state;
3448 cur_slots += req_payload.num_slots;
3451 drm_dp_mst_topology_put_port(port);
3454 for (i = 0; i < mgr->max_payloads; /* do nothing */) {
3455 if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL) {
3460 drm_dbg_kms(mgr->dev, "removing payload %d\n", i);
3461 for (j = i; j < mgr->max_payloads - 1; j++) {
3462 mgr->payloads[j] = mgr->payloads[j + 1];
3463 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
3465 if (mgr->proposed_vcpis[j] &&
3466 mgr->proposed_vcpis[j]->num_slots) {
3467 set_bit(j + 1, &mgr->payload_mask);
3469 clear_bit(j + 1, &mgr->payload_mask);
3473 memset(&mgr->payloads[mgr->max_payloads - 1], 0,
3474 sizeof(struct drm_dp_payload));
3475 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
3476 clear_bit(mgr->max_payloads, &mgr->payload_mask);
3478 mutex_unlock(&mgr->payload_lock);
3482 EXPORT_SYMBOL(drm_dp_update_payload_part1);
3485 * drm_dp_update_payload_part2() - Execute payload update part 2
3486 * @mgr: manager to use.
3488 * This iterates over all proposed virtual channels, and tries to
3489 * allocate space in the link for them. For 0->slots transitions,
3490 * this step writes the remote VC payload commands. For slots->0
3491 * this just resets some internal state.
3493 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
3495 struct drm_dp_mst_port *port;
3499 mutex_lock(&mgr->payload_lock);
3500 for (i = 0; i < mgr->max_payloads; i++) {
3502 if (!mgr->proposed_vcpis[i])
3505 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
3507 drm_dbg_kms(mgr->dev, "payload %d %d\n", i, mgr->payloads[i].payload_state);
3508 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
3509 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3510 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
3511 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3514 mutex_unlock(&mgr->payload_lock);
3518 mutex_unlock(&mgr->payload_lock);
3521 EXPORT_SYMBOL(drm_dp_update_payload_part2);
3523 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
3524 struct drm_dp_mst_port *port,
3525 int offset, int size, u8 *bytes)
3528 struct drm_dp_sideband_msg_tx *txmsg;
3529 struct drm_dp_mst_branch *mstb;
3531 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3535 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3541 build_dpcd_read(txmsg, port->port_num, offset, size);
3542 txmsg->dst = port->parent;
3544 drm_dp_queue_down_tx(mgr, txmsg);
3546 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3550 /* DPCD read should never be NACKed */
3551 if (txmsg->reply.reply_type == 1) {
3552 drm_err(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, mgr->dpcd[1], mgr->max_link_rate);
3726 mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr,
3727 drm_dp_bw_code_to_link_rate(link_rate),
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 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd,
3855 DP_RECEIVER_CAP_SIZE);
3856 if (ret != DP_RECEIVER_CAP_SIZE) {
3857 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n");
3861 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3864 DP_UPSTREAM_IS_SRC);
3866 drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n");
3870 /* Some hubs forget their guids after they resume */
3871 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
3873 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n");
3877 ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid);
3879 drm_dbg_kms(mgr->dev, "check mstb failed - undocked during suspend?\n");
3884 * For the final step of resuming the topology, we need to bring the
3885 * state of our in-memory topology back into sync with reality. So,
3886 * restart the probing process as if we're probing a new hub
3888 queue_work(system_long_wq, &mgr->work);
3889 mutex_unlock(&mgr->lock);
3892 drm_dbg_kms(mgr->dev,
3893 "Waiting for link probe work to finish re-syncing topology...\n");
3894 flush_work(&mgr->work);
3900 mutex_unlock(&mgr->lock);
3903 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
3906 drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up,
3907 struct drm_dp_mst_branch **mstb)
3911 int replylen, curreply;
3914 struct drm_dp_sideband_msg_hdr hdr;
3915 struct drm_dp_sideband_msg_rx *msg =
3916 up ? &mgr->up_req_recv : &mgr->down_rep_recv;
3917 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE :
3918 DP_SIDEBAND_MSG_DOWN_REP_BASE;
3923 len = min(mgr->max_dpcd_transaction_bytes, 16);
3924 ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len);
3926 drm_dbg_kms(mgr->dev, "failed to read DPCD down rep %d %d\n", len, ret);
3930 ret = drm_dp_decode_sideband_msg_hdr(mgr, &hdr, replyblock, len, &hdrlen);
3932 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16,
3933 1, replyblock, len, false);
3934 drm_dbg_kms(mgr->dev, "ERROR: failed header\n");
3939 /* Caller is responsible for giving back this reference */
3940 *mstb = drm_dp_get_mst_branch_device(mgr, hdr.lct, hdr.rad);
3942 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr.lct);
3947 if (!drm_dp_sideband_msg_set_header(msg, &hdr, hdrlen)) {
3948 drm_dbg_kms(mgr->dev, "sideband msg set header failed %d\n", replyblock[0]);
3952 replylen = min(msg->curchunk_len, (u8)(len - hdrlen));
3953 ret = drm_dp_sideband_append_payload(msg, replyblock + hdrlen, replylen);
3955 drm_dbg_kms(mgr->dev, "sideband msg build failed %d\n", replyblock[0]);
3959 replylen = msg->curchunk_len + msg->curchunk_hdrlen - len;
3961 while (replylen > 0) {
3962 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
3963 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
3966 drm_dbg_kms(mgr->dev, "failed to read a chunk (len %d, ret %d)\n",
3971 ret = drm_dp_sideband_append_payload(msg, replyblock, len);
3973 drm_dbg_kms(mgr->dev, "failed to build sideband msg\n");
3983 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
3985 struct drm_dp_sideband_msg_tx *txmsg;
3986 struct drm_dp_mst_branch *mstb = NULL;
3987 struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv;
3989 if (!drm_dp_get_one_sb_msg(mgr, false, &mstb))
3992 /* Multi-packet message transmission, don't clear the reply */
3993 if (!msg->have_eomt)
3996 /* find the message */
3997 mutex_lock(&mgr->qlock);
3998 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq,
3999 struct drm_dp_sideband_msg_tx, next);
4000 mutex_unlock(&mgr->qlock);
4002 /* Were we actually expecting a response, and from this mstb? */
4003 if (!txmsg || txmsg->dst != mstb) {
4004 struct drm_dp_sideband_msg_hdr *hdr;
4006 hdr = &msg->initial_hdr;
4007 drm_dbg_kms(mgr->dev, "Got MST reply with no msg %p %d %d %02x %02x\n",
4008 mstb, hdr->seqno, hdr->lct, hdr->rad[0], msg->msg[0]);
4009 goto out_clear_reply;
4012 drm_dp_sideband_parse_reply(mgr, msg, &txmsg->reply);
4014 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
4015 drm_dbg_kms(mgr->dev,
4016 "Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
4017 txmsg->reply.req_type,
4018 drm_dp_mst_req_type_str(txmsg->reply.req_type),
4019 txmsg->reply.u.nak.reason,
4020 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason),
4021 txmsg->reply.u.nak.nak_data);
4024 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
4025 drm_dp_mst_topology_put_mstb(mstb);
4027 mutex_lock(&mgr->qlock);
4028 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
4029 list_del(&txmsg->next);
4030 mutex_unlock(&mgr->qlock);
4032 wake_up_all(&mgr->tx_waitq);
4037 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx));
4040 drm_dp_mst_topology_put_mstb(mstb);
4046 drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
4047 struct drm_dp_pending_up_req *up_req)
4049 struct drm_dp_mst_branch *mstb = NULL;
4050 struct drm_dp_sideband_msg_req_body *msg = &up_req->msg;
4051 struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr;
4052 bool hotplug = false;
4054 if (hdr->broadcast) {
4055 const u8 *guid = NULL;
4057 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY)
4058 guid = msg->u.conn_stat.guid;
4059 else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
4060 guid = msg->u.resource_stat.guid;
4063 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
4065 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
4069 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr->lct);
4073 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */
4074 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) {
4075 drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat);
4079 drm_dp_mst_topology_put_mstb(mstb);
4083 static void drm_dp_mst_up_req_work(struct work_struct *work)
4085 struct drm_dp_mst_topology_mgr *mgr =
4086 container_of(work, struct drm_dp_mst_topology_mgr,
4088 struct drm_dp_pending_up_req *up_req;
4089 bool send_hotplug = false;
4091 mutex_lock(&mgr->probe_lock);
4093 mutex_lock(&mgr->up_req_lock);
4094 up_req = list_first_entry_or_null(&mgr->up_req_list,
4095 struct drm_dp_pending_up_req,
4098 list_del(&up_req->next);
4099 mutex_unlock(&mgr->up_req_lock);
4104 send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req);
4107 mutex_unlock(&mgr->probe_lock);
4110 drm_kms_helper_hotplug_event(mgr->dev);
4113 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
4115 struct drm_dp_pending_up_req *up_req;
4117 if (!drm_dp_get_one_sb_msg(mgr, true, NULL))
4120 if (!mgr->up_req_recv.have_eomt)
4123 up_req = kzalloc(sizeof(*up_req), GFP_KERNEL);
4127 INIT_LIST_HEAD(&up_req->next);
4129 drm_dp_sideband_parse_req(mgr, &mgr->up_req_recv, &up_req->msg);
4131 if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY &&
4132 up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) {
4133 drm_dbg_kms(mgr->dev, "Received unknown up req type, ignoring: %x\n",
4134 up_req->msg.req_type);
4139 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type,
4142 if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
4143 const struct drm_dp_connection_status_notify *conn_stat =
4144 &up_req->msg.u.conn_stat;
4146 drm_dbg_kms(mgr->dev, "Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
4147 conn_stat->port_number,
4148 conn_stat->legacy_device_plug_status,
4149 conn_stat->displayport_device_plug_status,
4150 conn_stat->message_capability_status,
4151 conn_stat->input_port,
4152 conn_stat->peer_device_type);
4153 } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
4154 const struct drm_dp_resource_status_notify *res_stat =
4155 &up_req->msg.u.resource_stat;
4157 drm_dbg_kms(mgr->dev, "Got RSN: pn: %d avail_pbn %d\n",
4158 res_stat->port_number,
4159 res_stat->available_pbn);
4162 up_req->hdr = mgr->up_req_recv.initial_hdr;
4163 mutex_lock(&mgr->up_req_lock);
4164 list_add_tail(&up_req->next, &mgr->up_req_list);
4165 mutex_unlock(&mgr->up_req_lock);
4166 queue_work(system_long_wq, &mgr->up_req_work);
4169 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
4174 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
4175 * @mgr: manager to notify irq for.
4176 * @esi: 4 bytes from SINK_COUNT_ESI
4177 * @handled: whether the hpd interrupt was consumed or not
4179 * This should be called from the driver when it detects a short IRQ,
4180 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
4181 * topology manager will process the sideband messages received as a result
4184 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
4191 if (sc != mgr->sink_count) {
4192 mgr->sink_count = sc;
4196 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
4197 ret = drm_dp_mst_handle_down_rep(mgr);
4201 if (esi[1] & DP_UP_REQ_MSG_RDY) {
4202 ret |= drm_dp_mst_handle_up_req(mgr);
4206 drm_dp_mst_kick_tx(mgr);
4209 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
4212 * drm_dp_mst_detect_port() - get connection status for an MST port
4213 * @connector: DRM connector for this port
4214 * @ctx: The acquisition context to use for grabbing locks
4215 * @mgr: manager for this port
4216 * @port: pointer to a port
4218 * This returns the current connection state for a port.
4221 drm_dp_mst_detect_port(struct drm_connector *connector,
4222 struct drm_modeset_acquire_ctx *ctx,
4223 struct drm_dp_mst_topology_mgr *mgr,
4224 struct drm_dp_mst_port *port)
4228 /* we need to search for the port in the mgr in case it's gone */
4229 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4231 return connector_status_disconnected;
4233 ret = drm_modeset_lock(&mgr->base.lock, ctx);
4237 ret = connector_status_disconnected;
4242 switch (port->pdt) {
4243 case DP_PEER_DEVICE_NONE:
4245 case DP_PEER_DEVICE_MST_BRANCHING:
4247 ret = connector_status_connected;
4250 case DP_PEER_DEVICE_SST_SINK:
4251 ret = connector_status_connected;
4252 /* for logical ports - cache the EDID */
4253 if (port->port_num >= DP_MST_LOGICAL_PORT_0 && !port->cached_edid)
4254 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
4256 case DP_PEER_DEVICE_DP_LEGACY_CONV:
4258 ret = connector_status_connected;
4262 drm_dp_mst_topology_put_port(port);
4265 EXPORT_SYMBOL(drm_dp_mst_detect_port);
4268 * drm_dp_mst_get_edid() - get EDID for an MST port
4269 * @connector: toplevel connector to get EDID for
4270 * @mgr: manager for this port
4271 * @port: unverified pointer to a port.
4273 * This returns an EDID for the port connected to a connector,
4274 * It validates the pointer still exists so the caller doesn't require a
4277 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4279 struct edid *edid = NULL;
4281 /* we need to search for the port in the mgr in case it's gone */
4282 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4286 if (port->cached_edid)
4287 edid = drm_edid_duplicate(port->cached_edid);
4289 edid = drm_get_edid(connector, &port->aux.ddc);
4291 port->has_audio = drm_detect_monitor_audio(edid);
4292 drm_dp_mst_topology_put_port(port);
4295 EXPORT_SYMBOL(drm_dp_mst_get_edid);
4298 * drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
4299 * @mgr: manager to use
4300 * @pbn: payload bandwidth to convert into slots.
4302 * Calculate the number of VCPI slots that will be required for the given PBN
4303 * value. This function is deprecated, and should not be used in atomic
4307 * The total slots required for this port, or error.
4309 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
4314 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
4316 /* max. time slots - one slot for MTP header */
4321 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
4323 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4324 struct drm_dp_vcpi *vcpi, int pbn, int slots)
4328 /* max. time slots - one slot for MTP header */
4333 vcpi->aligned_pbn = slots * mgr->pbn_div;
4334 vcpi->num_slots = slots;
4336 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
4343 * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
4344 * @state: global atomic state
4345 * @mgr: MST topology manager for the port
4346 * @port: port to find vcpi slots for
4347 * @pbn: bandwidth required for the mode in PBN
4348 * @pbn_div: divider for DSC mode that takes FEC into account
4350 * Allocates VCPI slots to @port, replacing any previous VCPI allocations it
4351 * may have had. Any atomic drivers which support MST must call this function
4352 * in their &drm_encoder_helper_funcs.atomic_check() callback to change the
4353 * current VCPI allocation for the new state, but only when
4354 * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set
4355 * to ensure compatibility with userspace applications that still use the
4356 * legacy modesetting UAPI.
4358 * Allocations set by this function are not checked against the bandwidth
4359 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
4361 * Additionally, it is OK to call this function multiple times on the same
4362 * @port as needed. It is not OK however, to call this function and
4363 * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
4366 * drm_dp_atomic_release_vcpi_slots()
4367 * drm_dp_mst_atomic_check()
4370 * Total slots in the atomic state assigned for this port, or a negative error
4371 * code if the port no longer exists
4373 int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
4374 struct drm_dp_mst_topology_mgr *mgr,
4375 struct drm_dp_mst_port *port, int pbn,
4378 struct drm_dp_mst_topology_state *topology_state;
4379 struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
4380 int prev_slots, prev_bw, req_slots;
4382 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4383 if (IS_ERR(topology_state))
4384 return PTR_ERR(topology_state);
4386 /* Find the current allocation for this port, if any */
4387 list_for_each_entry(pos, &topology_state->vcpis, next) {
4388 if (pos->port == port) {
4390 prev_slots = vcpi->vcpi;
4391 prev_bw = vcpi->pbn;
4394 * This should never happen, unless the driver tries
4395 * releasing and allocating the same VCPI allocation,
4398 if (WARN_ON(!prev_slots)) {
4400 "cannot allocate and release VCPI on [MST PORT:%p] in the same state\n",
4414 pbn_div = mgr->pbn_div;
4416 req_slots = DIV_ROUND_UP(pbn, pbn_div);
4418 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
4419 port->connector->base.id, port->connector->name,
4420 port, prev_slots, req_slots);
4421 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n",
4422 port->connector->base.id, port->connector->name,
4423 port, prev_bw, pbn);
4425 /* Add the new allocation to the state */
4427 vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL);
4431 drm_dp_mst_get_port_malloc(port);
4433 list_add(&vcpi->next, &topology_state->vcpis);
4435 vcpi->vcpi = req_slots;
4440 EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
4443 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
4444 * @state: global atomic state
4445 * @mgr: MST topology manager for the port
4446 * @port: The port to release the VCPI slots from
4448 * Releases any VCPI slots that have been allocated to a port in the atomic
4449 * state. Any atomic drivers which support MST must call this function in
4450 * their &drm_connector_helper_funcs.atomic_check() callback when the
4451 * connector will no longer have VCPI allocated (e.g. because its CRTC was
4452 * removed) when it had VCPI allocated in the previous atomic state.
4454 * It is OK to call this even if @port has been removed from the system.
4455 * Additionally, it is OK to call this function multiple times on the same
4456 * @port as needed. It is not OK however, to call this function and
4457 * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
4461 * drm_dp_atomic_find_vcpi_slots()
4462 * drm_dp_mst_atomic_check()
4465 * 0 if all slots for this port were added back to
4466 * &drm_dp_mst_topology_state.avail_slots or negative error code
4468 int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
4469 struct drm_dp_mst_topology_mgr *mgr,
4470 struct drm_dp_mst_port *port)
4472 struct drm_dp_mst_topology_state *topology_state;
4473 struct drm_dp_vcpi_allocation *pos;
4476 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4477 if (IS_ERR(topology_state))
4478 return PTR_ERR(topology_state);
4480 list_for_each_entry(pos, &topology_state->vcpis, next) {
4481 if (pos->port == port) {
4486 if (WARN_ON(!found)) {
4487 drm_err(mgr->dev, "no VCPI for [MST PORT:%p] found in mst state %p\n",
4488 port, &topology_state->base);
4492 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi);
4494 drm_dp_mst_put_port_malloc(port);
4501 EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
4504 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
4505 * @mgr: manager for this port
4506 * @port: port to allocate a virtual channel for.
4507 * @pbn: payload bandwidth number to request
4508 * @slots: returned number of slots for this PBN.
4510 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4511 struct drm_dp_mst_port *port, int pbn, int slots)
4518 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4522 if (port->vcpi.vcpi > 0) {
4523 drm_dbg_kms(mgr->dev,
4524 "payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
4525 port->vcpi.vcpi, port->vcpi.pbn, pbn);
4526 if (pbn == port->vcpi.pbn) {
4527 drm_dp_mst_topology_put_port(port);
4532 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
4534 drm_dbg_kms(mgr->dev, "failed to init vcpi slots=%d max=63 ret=%d\n",
4535 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
4536 drm_dp_mst_topology_put_port(port);
4539 drm_dbg_kms(mgr->dev, "initing vcpi for pbn=%d slots=%d\n", pbn, port->vcpi.num_slots);
4541 /* Keep port allocated until its payload has been removed */
4542 drm_dp_mst_get_port_malloc(port);
4543 drm_dp_mst_topology_put_port(port);
4548 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
4550 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4554 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4558 slots = port->vcpi.num_slots;
4559 drm_dp_mst_topology_put_port(port);
4562 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
4565 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
4566 * @mgr: manager for this port
4567 * @port: unverified pointer to a port.
4569 * This just resets the number of slots for the ports VCPI for later programming.
4571 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4574 * A port with VCPI will remain allocated until its VCPI is
4575 * released, no verified ref needed
4578 port->vcpi.num_slots = 0;
4580 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
4583 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
4584 * @mgr: manager for this port
4585 * @port: port to deallocate vcpi for
4587 * This can be called unconditionally, regardless of whether
4588 * drm_dp_mst_allocate_vcpi() succeeded or not.
4590 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4591 struct drm_dp_mst_port *port)
4593 if (!port->vcpi.vcpi)
4596 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
4597 port->vcpi.num_slots = 0;
4599 port->vcpi.aligned_pbn = 0;
4600 port->vcpi.vcpi = 0;
4601 drm_dp_mst_put_port_malloc(port);
4603 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
4605 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
4606 int id, struct drm_dp_payload *payload)
4608 u8 payload_alloc[3], status;
4612 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
4613 DP_PAYLOAD_TABLE_UPDATED);
4615 payload_alloc[0] = id;
4616 payload_alloc[1] = payload->start_slot;
4617 payload_alloc[2] = payload->num_slots;
4619 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
4621 drm_dbg_kms(mgr->dev, "failed to write payload allocation %d\n", ret);
4626 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4628 drm_dbg_kms(mgr->dev, "failed to read payload table status %d\n", ret);
4632 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
4635 usleep_range(10000, 20000);
4638 drm_dbg_kms(mgr->dev, "status not set after read payload table status %d\n",
4648 static int do_get_act_status(struct drm_dp_aux *aux)
4653 ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4661 * drm_dp_check_act_status() - Polls for ACT handled status.
4662 * @mgr: manager to use
4664 * Tries waiting for the MST hub to finish updating it's payload table by
4665 * polling for the ACT handled bit for up to 3 seconds (yes-some hubs really
4669 * 0 if the ACT was handled in time, negative error code on failure.
4671 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
4674 * There doesn't seem to be any recommended retry count or timeout in
4675 * the MST specification. Since some hubs have been observed to take
4676 * over 1 second to update their payload allocations under certain
4677 * conditions, we use a rather large timeout value.
4679 const int timeout_ms = 3000;
4682 ret = readx_poll_timeout(do_get_act_status, mgr->aux, status,
4683 status & DP_PAYLOAD_ACT_HANDLED || status < 0,
4684 200, timeout_ms * USEC_PER_MSEC);
4685 if (ret < 0 && status >= 0) {
4686 drm_err(mgr->dev, "Failed to get ACT after %dms, last status: %02x\n",
4687 timeout_ms, status);
4689 } else if (status < 0) {
4691 * Failure here isn't unexpected - the hub may have
4692 * just been unplugged
4694 drm_dbg_kms(mgr->dev, "Failed to read payload table status: %d\n", status);
4700 EXPORT_SYMBOL(drm_dp_check_act_status);
4703 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
4704 * @clock: dot clock for the mode
4705 * @bpp: bpp for the mode.
4706 * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel
4708 * This uses the formula in the spec to calculate the PBN value for a mode.
4710 int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc)
4713 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
4714 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
4715 * common multiplier to render an integer PBN for all link rate/lane
4716 * counts combinations
4718 * peak_kbps *= (1006/1000)
4719 * peak_kbps *= (64/54)
4720 * peak_kbps *= 8 convert to bytes
4722 * If the bpp is in units of 1/16, further divide by 16. Put this
4723 * factor in the numerator rather than the denominator to avoid
4728 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006),
4729 8 * 54 * 1000 * 1000);
4731 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
4732 8 * 54 * 1000 * 1000);
4734 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
4736 /* we want to kick the TX after we've ack the up/down IRQs. */
4737 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
4739 queue_work(system_long_wq, &mgr->tx_work);
4743 * Helper function for parsing DP device types into convenient strings
4744 * for use with dp_mst_topology
4746 static const char *pdt_to_string(u8 pdt)
4749 case DP_PEER_DEVICE_NONE:
4751 case DP_PEER_DEVICE_SOURCE_OR_SST:
4752 return "SOURCE OR SST";
4753 case DP_PEER_DEVICE_MST_BRANCHING:
4754 return "MST BRANCHING";
4755 case DP_PEER_DEVICE_SST_SINK:
4757 case DP_PEER_DEVICE_DP_LEGACY_CONV:
4758 return "DP LEGACY CONV";
4764 static void drm_dp_mst_dump_mstb(struct seq_file *m,
4765 struct drm_dp_mst_branch *mstb)
4767 struct drm_dp_mst_port *port;
4768 int tabs = mstb->lct;
4772 for (i = 0; i < tabs; i++)
4776 seq_printf(m, "%smstb - [%p]: num_ports: %d\n", prefix, mstb, mstb->num_ports);
4777 list_for_each_entry(port, &mstb->ports, next) {
4778 seq_printf(m, "%sport %d - [%p] (%s - %s): ddps: %d, ldps: %d, sdp: %d/%d, fec: %s, conn: %p\n",
4782 port->input ? "input" : "output",
4783 pdt_to_string(port->pdt),
4786 port->num_sdp_streams,
4787 port->num_sdp_stream_sinks,
4788 port->fec_capable ? "true" : "false",
4791 drm_dp_mst_dump_mstb(m, port->mstb);
4795 #define DP_PAYLOAD_TABLE_SIZE 64
4797 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
4802 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
4803 if (drm_dp_dpcd_read(mgr->aux,
4804 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
4811 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
4812 struct drm_dp_mst_port *port, char *name,
4815 struct edid *mst_edid;
4817 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
4818 drm_edid_get_monitor_name(mst_edid, name, namelen);
4822 * drm_dp_mst_dump_topology(): dump topology to seq file.
4823 * @m: seq_file to dump output to
4824 * @mgr: manager to dump current topology for.
4826 * helper to dump MST topology to a seq file for debugfs.
4828 void drm_dp_mst_dump_topology(struct seq_file *m,
4829 struct drm_dp_mst_topology_mgr *mgr)
4832 struct drm_dp_mst_port *port;
4834 mutex_lock(&mgr->lock);
4835 if (mgr->mst_primary)
4836 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
4839 mutex_unlock(&mgr->lock);
4841 mutex_lock(&mgr->payload_lock);
4842 seq_printf(m, "\n*** VCPI Info ***\n");
4843 seq_printf(m, "payload_mask: %lx, vcpi_mask: %lx, max_payloads: %d\n", mgr->payload_mask, mgr->vcpi_mask, mgr->max_payloads);
4845 seq_printf(m, "\n| idx | port # | vcp_id | # slots | sink name |\n");
4846 for (i = 0; i < mgr->max_payloads; i++) {
4847 if (mgr->proposed_vcpis[i]) {
4850 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
4851 fetch_monitor_name(mgr, port, name, sizeof(name));
4852 seq_printf(m, "%10d%10d%10d%10d%20s\n",
4856 port->vcpi.num_slots,
4857 (*name != 0) ? name : "Unknown");
4859 seq_printf(m, "%6d - Unused\n", i);
4861 seq_printf(m, "\n*** Payload Info ***\n");
4862 seq_printf(m, "| idx | state | start slot | # slots |\n");
4863 for (i = 0; i < mgr->max_payloads; i++) {
4864 seq_printf(m, "%10d%10d%15d%10d\n",
4866 mgr->payloads[i].payload_state,
4867 mgr->payloads[i].start_slot,
4868 mgr->payloads[i].num_slots);
4870 mutex_unlock(&mgr->payload_lock);
4872 seq_printf(m, "\n*** DPCD Info ***\n");
4873 mutex_lock(&mgr->lock);
4874 if (mgr->mst_primary) {
4875 u8 buf[DP_PAYLOAD_TABLE_SIZE];
4878 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
4880 seq_printf(m, "dpcd read failed\n");
4883 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
4885 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
4887 seq_printf(m, "faux/mst read failed\n");
4890 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
4892 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
4894 seq_printf(m, "mst ctrl read failed\n");
4897 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
4899 /* dump the standard OUI branch header */
4900 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
4902 seq_printf(m, "branch oui read failed\n");
4905 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
4907 for (i = 0x3; i < 0x8 && buf[i]; i++)
4908 seq_printf(m, "%c", buf[i]);
4909 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
4910 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
4911 if (dump_dp_payload_table(mgr, buf))
4912 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
4916 mutex_unlock(&mgr->lock);
4919 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
4921 static void drm_dp_tx_work(struct work_struct *work)
4923 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
4925 mutex_lock(&mgr->qlock);
4926 if (!list_empty(&mgr->tx_msg_downq))
4927 process_single_down_tx_qlock(mgr);
4928 mutex_unlock(&mgr->qlock);
4932 drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port)
4934 drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs);
4936 if (port->connector) {
4937 drm_connector_unregister(port->connector);
4938 drm_connector_put(port->connector);
4941 drm_dp_mst_put_port_malloc(port);
4945 drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb)
4947 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
4948 struct drm_dp_mst_port *port, *port_tmp;
4949 struct drm_dp_sideband_msg_tx *txmsg, *txmsg_tmp;
4950 bool wake_tx = false;
4952 mutex_lock(&mgr->lock);
4953 list_for_each_entry_safe(port, port_tmp, &mstb->ports, next) {
4954 list_del(&port->next);
4955 drm_dp_mst_topology_put_port(port);
4957 mutex_unlock(&mgr->lock);
4959 /* drop any tx slot msg */
4960 mutex_lock(&mstb->mgr->qlock);
4961 list_for_each_entry_safe(txmsg, txmsg_tmp, &mgr->tx_msg_downq, next) {
4962 if (txmsg->dst != mstb)
4965 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
4966 list_del(&txmsg->next);
4969 mutex_unlock(&mstb->mgr->qlock);
4972 wake_up_all(&mstb->mgr->tx_waitq);
4974 drm_dp_mst_put_mstb_malloc(mstb);
4977 static void drm_dp_delayed_destroy_work(struct work_struct *work)
4979 struct drm_dp_mst_topology_mgr *mgr =
4980 container_of(work, struct drm_dp_mst_topology_mgr,
4981 delayed_destroy_work);
4982 bool send_hotplug = false, go_again;
4985 * Not a regular list traverse as we have to drop the destroy
4986 * connector lock before destroying the mstb/port, to avoid AB->BA
4987 * ordering between this lock and the config mutex.
4993 struct drm_dp_mst_branch *mstb;
4995 mutex_lock(&mgr->delayed_destroy_lock);
4996 mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list,
4997 struct drm_dp_mst_branch,
5000 list_del(&mstb->destroy_next);
5001 mutex_unlock(&mgr->delayed_destroy_lock);
5006 drm_dp_delayed_destroy_mstb(mstb);
5011 struct drm_dp_mst_port *port;
5013 mutex_lock(&mgr->delayed_destroy_lock);
5014 port = list_first_entry_or_null(&mgr->destroy_port_list,
5015 struct drm_dp_mst_port,
5018 list_del(&port->next);
5019 mutex_unlock(&mgr->delayed_destroy_lock);
5024 drm_dp_delayed_destroy_port(port);
5025 send_hotplug = true;
5031 drm_kms_helper_hotplug_event(mgr->dev);
5034 static struct drm_private_state *
5035 drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
5037 struct drm_dp_mst_topology_state *state, *old_state =
5038 to_dp_mst_topology_state(obj->state);
5039 struct drm_dp_vcpi_allocation *pos, *vcpi;
5041 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
5045 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
5047 INIT_LIST_HEAD(&state->vcpis);
5049 list_for_each_entry(pos, &old_state->vcpis, next) {
5050 /* Prune leftover freed VCPI allocations */
5054 vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL);
5058 drm_dp_mst_get_port_malloc(vcpi->port);
5059 list_add(&vcpi->next, &state->vcpis);
5062 return &state->base;
5065 list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) {
5066 drm_dp_mst_put_port_malloc(pos->port);
5074 static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
5075 struct drm_private_state *state)
5077 struct drm_dp_mst_topology_state *mst_state =
5078 to_dp_mst_topology_state(state);
5079 struct drm_dp_vcpi_allocation *pos, *tmp;
5081 list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) {
5082 /* We only keep references to ports with non-zero VCPIs */
5084 drm_dp_mst_put_port_malloc(pos->port);
5091 static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port,
5092 struct drm_dp_mst_branch *branch)
5094 while (port->parent) {
5095 if (port->parent == branch)
5098 if (port->parent->port_parent)
5099 port = port->parent->port_parent;
5107 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
5108 struct drm_dp_mst_topology_state *state);
5111 drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb,
5112 struct drm_dp_mst_topology_state *state)
5114 struct drm_dp_vcpi_allocation *vcpi;
5115 struct drm_dp_mst_port *port;
5116 int pbn_used = 0, ret;
5119 /* Check that we have at least one port in our state that's downstream
5120 * of this branch, otherwise we can skip this branch
5122 list_for_each_entry(vcpi, &state->vcpis, next) {
5124 !drm_dp_mst_port_downstream_of_branch(vcpi->port, mstb))
5133 if (mstb->port_parent)
5134 drm_dbg_atomic(mstb->mgr->dev,
5135 "[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n",
5136 mstb->port_parent->parent, mstb->port_parent, mstb);
5138 drm_dbg_atomic(mstb->mgr->dev, "[MSTB:%p] Checking bandwidth limits\n", mstb);
5140 list_for_each_entry(port, &mstb->ports, next) {
5141 ret = drm_dp_mst_atomic_check_port_bw_limit(port, state);
5152 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port,
5153 struct drm_dp_mst_topology_state *state)
5155 struct drm_dp_vcpi_allocation *vcpi;
5158 if (port->pdt == DP_PEER_DEVICE_NONE)
5161 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) {
5164 list_for_each_entry(vcpi, &state->vcpis, next) {
5165 if (vcpi->port != port)
5177 * This could happen if the sink deasserted its HPD line, but
5178 * the branch device still reports it as attached (PDT != NONE).
5180 if (!port->full_pbn) {
5181 drm_dbg_atomic(port->mgr->dev,
5182 "[MSTB:%p] [MST PORT:%p] no BW available for the port\n",
5183 port->parent, port);
5187 pbn_used = vcpi->pbn;
5189 pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb,
5195 if (pbn_used > port->full_pbn) {
5196 drm_dbg_atomic(port->mgr->dev,
5197 "[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n",
5198 port->parent, port, pbn_used, port->full_pbn);
5202 drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n",
5203 port->parent, port, pbn_used, port->full_pbn);
5209 drm_dp_mst_atomic_check_vcpi_alloc_limit(struct drm_dp_mst_topology_mgr *mgr,
5210 struct drm_dp_mst_topology_state *mst_state)
5212 struct drm_dp_vcpi_allocation *vcpi;
5213 int avail_slots = 63, payload_count = 0;
5215 list_for_each_entry(vcpi, &mst_state->vcpis, next) {
5216 /* Releasing VCPI is always OK-even if the port is gone */
5218 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] releases all VCPI slots\n",
5223 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] requires %d vcpi slots\n",
5224 vcpi->port, vcpi->vcpi);
5226 avail_slots -= vcpi->vcpi;
5227 if (avail_slots < 0) {
5228 drm_dbg_atomic(mgr->dev,
5229 "[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n",
5230 vcpi->port, mst_state, avail_slots + vcpi->vcpi);
5234 if (++payload_count > mgr->max_payloads) {
5235 drm_dbg_atomic(mgr->dev,
5236 "[MST MGR:%p] state %p has too many payloads (max=%d)\n",
5237 mgr, mst_state, mgr->max_payloads);
5241 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
5242 mgr, mst_state, avail_slots, 63 - avail_slots);
5248 * drm_dp_mst_add_affected_dsc_crtcs
5249 * @state: Pointer to the new struct drm_dp_mst_topology_state
5250 * @mgr: MST topology manager
5252 * Whenever there is a change in mst topology
5253 * DSC configuration would have to be recalculated
5254 * therefore we need to trigger modeset on all affected
5255 * CRTCs in that topology
5258 * drm_dp_mst_atomic_enable_dsc()
5260 int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr)
5262 struct drm_dp_mst_topology_state *mst_state;
5263 struct drm_dp_vcpi_allocation *pos;
5264 struct drm_connector *connector;
5265 struct drm_connector_state *conn_state;
5266 struct drm_crtc *crtc;
5267 struct drm_crtc_state *crtc_state;
5269 mst_state = drm_atomic_get_mst_topology_state(state, mgr);
5271 if (IS_ERR(mst_state))
5274 list_for_each_entry(pos, &mst_state->vcpis, next) {
5276 connector = pos->port->connector;
5281 conn_state = drm_atomic_get_connector_state(state, connector);
5283 if (IS_ERR(conn_state))
5284 return PTR_ERR(conn_state);
5286 crtc = conn_state->crtc;
5291 if (!drm_dp_mst_dsc_aux_for_port(pos->port))
5294 crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc);
5296 if (IS_ERR(crtc_state))
5297 return PTR_ERR(crtc_state);
5299 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] Setting mode_changed flag on CRTC %p\n",
5302 crtc_state->mode_changed = true;
5306 EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs);
5309 * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off
5310 * @state: Pointer to the new drm_atomic_state
5311 * @port: Pointer to the affected MST Port
5312 * @pbn: Newly recalculated bw required for link with DSC enabled
5313 * @pbn_div: Divider to calculate correct number of pbn per slot
5314 * @enable: Boolean flag to enable or disable DSC on the port
5316 * This function enables DSC on the given Port
5317 * by recalculating its vcpi from pbn provided
5318 * and sets dsc_enable flag to keep track of which
5319 * ports have DSC enabled
5322 int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state,
5323 struct drm_dp_mst_port *port,
5324 int pbn, int pbn_div,
5327 struct drm_dp_mst_topology_state *mst_state;
5328 struct drm_dp_vcpi_allocation *pos;
5332 mst_state = drm_atomic_get_mst_topology_state(state, port->mgr);
5334 if (IS_ERR(mst_state))
5335 return PTR_ERR(mst_state);
5337 list_for_each_entry(pos, &mst_state->vcpis, next) {
5338 if (pos->port == port) {
5345 drm_dbg_atomic(state->dev,
5346 "[MST PORT:%p] Couldn't find VCPI allocation in mst state %p\n",
5351 if (pos->dsc_enabled == enable) {
5352 drm_dbg_atomic(state->dev,
5353 "[MST PORT:%p] DSC flag is already set to %d, returning %d VCPI slots\n",
5354 port, enable, pos->vcpi);
5359 vcpi = drm_dp_atomic_find_vcpi_slots(state, port->mgr, port, pbn, pbn_div);
5360 drm_dbg_atomic(state->dev,
5361 "[MST PORT:%p] Enabling DSC flag, reallocating %d VCPI slots on the port\n",
5367 pos->dsc_enabled = enable;
5371 EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc);
5373 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
5374 * atomic update is valid
5375 * @state: Pointer to the new &struct drm_dp_mst_topology_state
5377 * Checks the given topology state for an atomic update to ensure that it's
5378 * valid. This includes checking whether there's enough bandwidth to support
5379 * the new VCPI allocations in the atomic update.
5381 * Any atomic drivers supporting DP MST must make sure to call this after
5382 * checking the rest of their state in their
5383 * &drm_mode_config_funcs.atomic_check() callback.
5386 * drm_dp_atomic_find_vcpi_slots()
5387 * drm_dp_atomic_release_vcpi_slots()
5391 * 0 if the new state is valid, negative error code otherwise.
5393 int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
5395 struct drm_dp_mst_topology_mgr *mgr;
5396 struct drm_dp_mst_topology_state *mst_state;
5399 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
5400 if (!mgr->mst_state)
5403 ret = drm_dp_mst_atomic_check_vcpi_alloc_limit(mgr, mst_state);
5407 mutex_lock(&mgr->lock);
5408 ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary,
5410 mutex_unlock(&mgr->lock);
5419 EXPORT_SYMBOL(drm_dp_mst_atomic_check);
5421 const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
5422 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
5423 .atomic_destroy_state = drm_dp_mst_destroy_state,
5425 EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
5428 * drm_atomic_get_mst_topology_state: get MST topology state
5430 * @state: global atomic state
5431 * @mgr: MST topology manager, also the private object in this case
5433 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
5434 * state vtable so that the private object state returned is that of a MST
5435 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
5436 * to care of the locking, so warn if don't hold the connection_mutex.
5440 * The MST topology state or error pointer.
5442 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
5443 struct drm_dp_mst_topology_mgr *mgr)
5445 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
5447 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
5450 * drm_dp_mst_topology_mgr_init - initialise a topology manager
5451 * @mgr: manager struct to initialise
5452 * @dev: device providing this structure - for i2c addition.
5453 * @aux: DP helper aux channel to talk to this device
5454 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
5455 * @max_payloads: maximum number of payloads this GPU can source
5456 * @max_lane_count: maximum number of lanes this GPU supports
5457 * @max_link_rate: maximum link rate this GPU supports, units as in DPCD
5458 * @conn_base_id: the connector object ID the MST device is connected to.
5460 * Return 0 for success, or negative error code on failure
5462 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
5463 struct drm_device *dev, struct drm_dp_aux *aux,
5464 int max_dpcd_transaction_bytes, int max_payloads,
5465 u8 max_lane_count, u8 max_link_rate,
5468 struct drm_dp_mst_topology_state *mst_state;
5470 mutex_init(&mgr->lock);
5471 mutex_init(&mgr->qlock);
5472 mutex_init(&mgr->payload_lock);
5473 mutex_init(&mgr->delayed_destroy_lock);
5474 mutex_init(&mgr->up_req_lock);
5475 mutex_init(&mgr->probe_lock);
5476 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5477 mutex_init(&mgr->topology_ref_history_lock);
5479 INIT_LIST_HEAD(&mgr->tx_msg_downq);
5480 INIT_LIST_HEAD(&mgr->destroy_port_list);
5481 INIT_LIST_HEAD(&mgr->destroy_branch_device_list);
5482 INIT_LIST_HEAD(&mgr->up_req_list);
5485 * delayed_destroy_work will be queued on a dedicated WQ, so that any
5486 * requeuing will be also flushed when deiniting the topology manager.
5488 mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0);
5489 if (mgr->delayed_destroy_wq == NULL)
5492 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
5493 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
5494 INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work);
5495 INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work);
5496 init_waitqueue_head(&mgr->tx_waitq);
5499 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
5500 mgr->max_payloads = max_payloads;
5501 mgr->max_lane_count = max_lane_count;
5502 mgr->max_link_rate = max_link_rate;
5503 mgr->conn_base_id = conn_base_id;
5504 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
5505 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
5507 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
5510 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
5511 if (!mgr->proposed_vcpis)
5513 set_bit(0, &mgr->payload_mask);
5515 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
5516 if (mst_state == NULL)
5519 mst_state->mgr = mgr;
5520 INIT_LIST_HEAD(&mst_state->vcpis);
5522 drm_atomic_private_obj_init(dev, &mgr->base,
5524 &drm_dp_mst_topology_state_funcs);
5528 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
5531 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
5532 * @mgr: manager to destroy
5534 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
5536 drm_dp_mst_topology_mgr_set_mst(mgr, false);
5537 flush_work(&mgr->work);
5538 /* The following will also drain any requeued work on the WQ. */
5539 if (mgr->delayed_destroy_wq) {
5540 destroy_workqueue(mgr->delayed_destroy_wq);
5541 mgr->delayed_destroy_wq = NULL;
5543 mutex_lock(&mgr->payload_lock);
5544 kfree(mgr->payloads);
5545 mgr->payloads = NULL;
5546 kfree(mgr->proposed_vcpis);
5547 mgr->proposed_vcpis = NULL;
5548 mutex_unlock(&mgr->payload_lock);
5551 drm_atomic_private_obj_fini(&mgr->base);
5554 mutex_destroy(&mgr->delayed_destroy_lock);
5555 mutex_destroy(&mgr->payload_lock);
5556 mutex_destroy(&mgr->qlock);
5557 mutex_destroy(&mgr->lock);
5558 mutex_destroy(&mgr->up_req_lock);
5559 mutex_destroy(&mgr->probe_lock);
5560 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
5561 mutex_destroy(&mgr->topology_ref_history_lock);
5564 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
5566 static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
5570 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
5573 for (i = 0; i < num - 1; i++) {
5574 if (msgs[i].flags & I2C_M_RD ||
5579 return msgs[num - 1].flags & I2C_M_RD &&
5580 msgs[num - 1].len <= 0xff;
5583 static bool remote_i2c_write_ok(const struct i2c_msg msgs[], int num)
5587 for (i = 0; i < num - 1; i++) {
5588 if (msgs[i].flags & I2C_M_RD || !(msgs[i].flags & I2C_M_STOP) ||
5593 return !(msgs[num - 1].flags & I2C_M_RD) && msgs[num - 1].len <= 0xff;
5596 static int drm_dp_mst_i2c_read(struct drm_dp_mst_branch *mstb,
5597 struct drm_dp_mst_port *port,
5598 struct i2c_msg *msgs, int num)
5600 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5602 struct drm_dp_sideband_msg_req_body msg;
5603 struct drm_dp_sideband_msg_tx *txmsg = NULL;
5606 memset(&msg, 0, sizeof(msg));
5607 msg.req_type = DP_REMOTE_I2C_READ;
5608 msg.u.i2c_read.num_transactions = num - 1;
5609 msg.u.i2c_read.port_number = port->port_num;
5610 for (i = 0; i < num - 1; i++) {
5611 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
5612 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
5613 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
5614 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
5616 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
5617 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
5619 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5626 drm_dp_encode_sideband_req(&msg, txmsg);
5628 drm_dp_queue_down_tx(mgr, txmsg);
5630 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5633 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5637 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
5641 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
5649 static int drm_dp_mst_i2c_write(struct drm_dp_mst_branch *mstb,
5650 struct drm_dp_mst_port *port,
5651 struct i2c_msg *msgs, int num)
5653 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5655 struct drm_dp_sideband_msg_req_body msg;
5656 struct drm_dp_sideband_msg_tx *txmsg = NULL;
5659 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
5664 for (i = 0; i < num; i++) {
5665 memset(&msg, 0, sizeof(msg));
5666 msg.req_type = DP_REMOTE_I2C_WRITE;
5667 msg.u.i2c_write.port_number = port->port_num;
5668 msg.u.i2c_write.write_i2c_device_id = msgs[i].addr;
5669 msg.u.i2c_write.num_bytes = msgs[i].len;
5670 msg.u.i2c_write.bytes = msgs[i].buf;
5672 memset(txmsg, 0, sizeof(*txmsg));
5675 drm_dp_encode_sideband_req(&msg, txmsg);
5676 drm_dp_queue_down_tx(mgr, txmsg);
5678 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5680 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5695 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter,
5696 struct i2c_msg *msgs, int num)
5698 struct drm_dp_aux *aux = adapter->algo_data;
5699 struct drm_dp_mst_port *port =
5700 container_of(aux, struct drm_dp_mst_port, aux);
5701 struct drm_dp_mst_branch *mstb;
5702 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
5705 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
5709 if (remote_i2c_read_ok(msgs, num)) {
5710 ret = drm_dp_mst_i2c_read(mstb, port, msgs, num);
5711 } else if (remote_i2c_write_ok(msgs, num)) {
5712 ret = drm_dp_mst_i2c_write(mstb, port, msgs, num);
5714 drm_dbg_kms(mgr->dev, "Unsupported I2C transaction for MST device\n");
5718 drm_dp_mst_topology_put_mstb(mstb);
5722 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
5724 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
5725 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
5726 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
5727 I2C_FUNC_10BIT_ADDR;
5730 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
5731 .functionality = drm_dp_mst_i2c_functionality,
5732 .master_xfer = drm_dp_mst_i2c_xfer,
5736 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
5737 * @port: The port to add the I2C bus on
5739 * Returns 0 on success or a negative error code on failure.
5741 static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port)
5743 struct drm_dp_aux *aux = &port->aux;
5744 struct device *parent_dev = port->mgr->dev->dev;
5746 aux->ddc.algo = &drm_dp_mst_i2c_algo;
5747 aux->ddc.algo_data = aux;
5748 aux->ddc.retries = 3;
5750 aux->ddc.class = I2C_CLASS_DDC;
5751 aux->ddc.owner = THIS_MODULE;
5752 /* FIXME: set the kdev of the port's connector as parent */
5753 aux->ddc.dev.parent = parent_dev;
5754 aux->ddc.dev.of_node = parent_dev->of_node;
5756 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev),
5757 sizeof(aux->ddc.name));
5759 return i2c_add_adapter(&aux->ddc);
5763 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
5764 * @port: The port to remove the I2C bus from
5766 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port)
5768 i2c_del_adapter(&port->aux.ddc);
5772 * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device
5773 * @port: The port to check
5775 * A single physical MST hub object can be represented in the topology
5776 * by multiple branches, with virtual ports between those branches.
5778 * As of DP1.4, An MST hub with internal (virtual) ports must expose
5779 * certain DPCD registers over those ports. See sections 2.6.1.1.1
5780 * and 2.6.1.1.2 of Display Port specification v1.4 for details.
5782 * May acquire mgr->lock
5785 * true if the port is a virtual DP peer device, false otherwise
5787 static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port)
5789 struct drm_dp_mst_port *downstream_port;
5791 if (!port || port->dpcd_rev < DP_DPCD_REV_14)
5794 /* Virtual DP Sink (Internal Display Panel) */
5795 if (port->port_num >= 8)
5798 /* DP-to-HDMI Protocol Converter */
5799 if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV &&
5805 mutex_lock(&port->mgr->lock);
5806 if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING &&
5808 port->mstb->num_ports == 2) {
5809 list_for_each_entry(downstream_port, &port->mstb->ports, next) {
5810 if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK &&
5811 !downstream_port->input) {
5812 mutex_unlock(&port->mgr->lock);
5817 mutex_unlock(&port->mgr->lock);
5823 * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC
5824 * @port: The port to check. A leaf of the MST tree with an attached display.
5826 * Depending on the situation, DSC may be enabled via the endpoint aux,
5827 * the immediately upstream aux, or the connector's physical aux.
5829 * This is both the correct aux to read DSC_CAPABILITY and the
5830 * correct aux to write DSC_ENABLED.
5832 * This operation can be expensive (up to four aux reads), so
5833 * the caller should cache the return.
5836 * NULL if DSC cannot be enabled on this port, otherwise the aux device
5838 struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port)
5840 struct drm_dp_mst_port *immediate_upstream_port;
5841 struct drm_dp_mst_port *fec_port;
5842 struct drm_dp_desc desc = {};
5849 if (port->parent->port_parent)
5850 immediate_upstream_port = port->parent->port_parent;
5852 immediate_upstream_port = NULL;
5854 fec_port = immediate_upstream_port;
5857 * Each physical link (i.e. not a virtual port) between the
5858 * output and the primary device must support FEC
5860 if (!drm_dp_mst_is_virtual_dpcd(fec_port) &&
5861 !fec_port->fec_capable)
5864 fec_port = fec_port->parent->port_parent;
5867 /* DP-to-DP peer device */
5868 if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) {
5871 if (drm_dp_dpcd_read(&port->aux,
5872 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5874 if (drm_dp_dpcd_read(&port->aux,
5875 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5877 if (drm_dp_dpcd_read(&immediate_upstream_port->aux,
5878 DP_DSC_SUPPORT, &upstream_dsc, 1) != 1)
5881 /* Enpoint decompression with DP-to-DP peer device */
5882 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5883 (endpoint_fec & DP_FEC_CAPABLE) &&
5884 (upstream_dsc & 0x2) /* DSC passthrough */)
5887 /* Virtual DPCD decompression with DP-to-DP peer device */
5888 return &immediate_upstream_port->aux;
5891 /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */
5892 if (drm_dp_mst_is_virtual_dpcd(port))
5897 * Applies to ports for which:
5898 * - Physical aux has Synaptics OUI
5899 * - DPv1.4 or higher
5900 * - Port is on primary branch device
5901 * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG)
5903 if (drm_dp_read_desc(port->mgr->aux, &desc, true))
5906 if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) &&
5907 port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 &&
5908 port->parent == port->mgr->mst_primary) {
5909 u8 dpcd_ext[DP_RECEIVER_CAP_SIZE];
5911 if (drm_dp_read_dpcd_caps(port->mgr->aux, dpcd_ext) < 0)
5914 if ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT) &&
5915 ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK)
5916 != DP_DWN_STRM_PORT_TYPE_ANALOG))
5917 return port->mgr->aux;
5921 * The check below verifies if the MST sink
5922 * connected to the GPU is capable of DSC -
5923 * therefore the endpoint needs to be
5924 * both DSC and FEC capable.
5926 if (drm_dp_dpcd_read(&port->aux,
5927 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1)
5929 if (drm_dp_dpcd_read(&port->aux,
5930 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1)
5932 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) &&
5933 (endpoint_fec & DP_FEC_CAPABLE))
5938 EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);