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/delay.h>
24 #include <linux/errno.h>
25 #include <linux/i2c.h>
26 #include <linux/init.h>
27 #include <linux/kernel.h>
28 #include <linux/sched.h>
29 #include <linux/seq_file.h>
31 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
32 #include <linux/stacktrace.h>
33 #include <linux/sort.h>
34 #include <linux/timekeeping.h>
35 #include <linux/math64.h>
38 #include <drm/drm_atomic.h>
39 #include <drm/drm_atomic_helper.h>
40 #include <drm/drm_dp_mst_helper.h>
41 #include <drm/drm_drv.h>
42 #include <drm/drm_print.h>
43 #include <drm/drm_probe_helper.h>
45 #include "drm_crtc_helper_internal.h"
46 #include "drm_dp_mst_topology_internal.h"
51 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
52 * protocol. The helpers contain a topology manager and bandwidth manager.
53 * The helpers encapsulate the sending and received of sideband msgs.
55 struct drm_dp_pending_up_req {
56 struct drm_dp_sideband_msg_hdr hdr;
57 struct drm_dp_sideband_msg_req_body msg;
58 struct list_head next;
61 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
64 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port);
66 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
68 struct drm_dp_payload *payload);
70 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
71 struct drm_dp_mst_port *port,
72 int offset, int size, u8 *bytes);
73 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
74 struct drm_dp_mst_port *port,
75 int offset, int size, u8 *bytes);
77 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
78 struct drm_dp_mst_branch *mstb);
81 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
82 struct drm_dp_mst_branch *mstb);
84 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
85 struct drm_dp_mst_branch *mstb,
86 struct drm_dp_mst_port *port);
87 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
90 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
91 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
92 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
94 #define DBG_PREFIX "[dp_mst]"
96 #define DP_STR(x) [DP_ ## x] = #x
98 static const char *drm_dp_mst_req_type_str(u8 req_type)
100 static const char * const req_type_str[] = {
101 DP_STR(GET_MSG_TRANSACTION_VERSION),
102 DP_STR(LINK_ADDRESS),
103 DP_STR(CONNECTION_STATUS_NOTIFY),
104 DP_STR(ENUM_PATH_RESOURCES),
105 DP_STR(ALLOCATE_PAYLOAD),
106 DP_STR(QUERY_PAYLOAD),
107 DP_STR(RESOURCE_STATUS_NOTIFY),
108 DP_STR(CLEAR_PAYLOAD_ID_TABLE),
109 DP_STR(REMOTE_DPCD_READ),
110 DP_STR(REMOTE_DPCD_WRITE),
111 DP_STR(REMOTE_I2C_READ),
112 DP_STR(REMOTE_I2C_WRITE),
113 DP_STR(POWER_UP_PHY),
114 DP_STR(POWER_DOWN_PHY),
115 DP_STR(SINK_EVENT_NOTIFY),
116 DP_STR(QUERY_STREAM_ENC_STATUS),
119 if (req_type >= ARRAY_SIZE(req_type_str) ||
120 !req_type_str[req_type])
123 return req_type_str[req_type];
127 #define DP_STR(x) [DP_NAK_ ## x] = #x
129 static const char *drm_dp_mst_nak_reason_str(u8 nak_reason)
131 static const char * const nak_reason_str[] = {
132 DP_STR(WRITE_FAILURE),
133 DP_STR(INVALID_READ),
137 DP_STR(LINK_FAILURE),
138 DP_STR(NO_RESOURCES),
141 DP_STR(ALLOCATE_FAIL),
144 if (nak_reason >= ARRAY_SIZE(nak_reason_str) ||
145 !nak_reason_str[nak_reason])
148 return nak_reason_str[nak_reason];
152 #define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x
154 static const char *drm_dp_mst_sideband_tx_state_str(int state)
156 static const char * const sideband_reason_str[] = {
164 if (state >= ARRAY_SIZE(sideband_reason_str) ||
165 !sideband_reason_str[state])
168 return sideband_reason_str[state];
172 drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len)
177 for (i = 0; i < lct; i++) {
179 unpacked_rad[i] = rad[i / 2] >> 4;
181 unpacked_rad[i] = rad[i / 2] & BIT_MASK(4);
184 /* TODO: Eventually add something to printk so we can format the rad
187 return snprintf(out, len, "%*phC", lct, unpacked_rad);
190 /* sideband msg handling */
191 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
196 int number_of_bits = num_nibbles * 4;
199 while (number_of_bits != 0) {
202 remainder |= (data[array_index] & bitmask) >> bitshift;
210 if ((remainder & 0x10) == 0x10)
215 while (number_of_bits != 0) {
218 if ((remainder & 0x10) != 0)
225 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
230 int number_of_bits = number_of_bytes * 8;
233 while (number_of_bits != 0) {
236 remainder |= (data[array_index] & bitmask) >> bitshift;
244 if ((remainder & 0x100) == 0x100)
249 while (number_of_bits != 0) {
252 if ((remainder & 0x100) != 0)
256 return remainder & 0xff;
258 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
261 size += (hdr->lct / 2);
265 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
271 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
272 for (i = 0; i < (hdr->lct / 2); i++)
273 buf[idx++] = hdr->rad[i];
274 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
275 (hdr->msg_len & 0x3f);
276 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
278 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
279 buf[idx - 1] |= (crc4 & 0xf);
284 static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
285 u8 *buf, int buflen, u8 *hdrlen)
294 len += ((buf[0] & 0xf0) >> 4) / 2;
297 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
299 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
300 DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
304 hdr->lct = (buf[0] & 0xf0) >> 4;
305 hdr->lcr = (buf[0] & 0xf);
307 for (i = 0; i < (hdr->lct / 2); i++)
308 hdr->rad[i] = buf[idx++];
309 hdr->broadcast = (buf[idx] >> 7) & 0x1;
310 hdr->path_msg = (buf[idx] >> 6) & 0x1;
311 hdr->msg_len = buf[idx] & 0x3f;
313 hdr->somt = (buf[idx] >> 7) & 0x1;
314 hdr->eomt = (buf[idx] >> 6) & 0x1;
315 hdr->seqno = (buf[idx] >> 4) & 0x1;
322 drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req,
323 struct drm_dp_sideband_msg_tx *raw)
328 buf[idx++] = req->req_type & 0x7f;
330 switch (req->req_type) {
331 case DP_ENUM_PATH_RESOURCES:
332 case DP_POWER_DOWN_PHY:
333 case DP_POWER_UP_PHY:
334 buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
337 case DP_ALLOCATE_PAYLOAD:
338 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
339 (req->u.allocate_payload.number_sdp_streams & 0xf);
341 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
343 buf[idx] = (req->u.allocate_payload.pbn >> 8);
345 buf[idx] = (req->u.allocate_payload.pbn & 0xff);
347 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
348 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
349 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
352 if (req->u.allocate_payload.number_sdp_streams & 1) {
353 i = req->u.allocate_payload.number_sdp_streams - 1;
354 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
358 case DP_QUERY_PAYLOAD:
359 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
361 buf[idx] = (req->u.query_payload.vcpi & 0x7f);
364 case DP_REMOTE_DPCD_READ:
365 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
366 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
368 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
370 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
372 buf[idx] = (req->u.dpcd_read.num_bytes);
376 case DP_REMOTE_DPCD_WRITE:
377 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
378 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
380 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
382 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
384 buf[idx] = (req->u.dpcd_write.num_bytes);
386 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
387 idx += req->u.dpcd_write.num_bytes;
389 case DP_REMOTE_I2C_READ:
390 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
391 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
393 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
394 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
396 buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
398 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
399 idx += req->u.i2c_read.transactions[i].num_bytes;
401 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
402 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
405 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
407 buf[idx] = (req->u.i2c_read.num_bytes_read);
411 case DP_REMOTE_I2C_WRITE:
412 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
414 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
416 buf[idx] = (req->u.i2c_write.num_bytes);
418 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
419 idx += req->u.i2c_write.num_bytes;
424 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req);
426 /* Decode a sideband request we've encoded, mainly used for debugging */
428 drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw,
429 struct drm_dp_sideband_msg_req_body *req)
431 const u8 *buf = raw->msg;
434 req->req_type = buf[idx++] & 0x7f;
435 switch (req->req_type) {
436 case DP_ENUM_PATH_RESOURCES:
437 case DP_POWER_DOWN_PHY:
438 case DP_POWER_UP_PHY:
439 req->u.port_num.port_number = (buf[idx] >> 4) & 0xf;
441 case DP_ALLOCATE_PAYLOAD:
443 struct drm_dp_allocate_payload *a =
444 &req->u.allocate_payload;
446 a->number_sdp_streams = buf[idx] & 0xf;
447 a->port_number = (buf[idx] >> 4) & 0xf;
449 WARN_ON(buf[++idx] & 0x80);
450 a->vcpi = buf[idx] & 0x7f;
452 a->pbn = buf[++idx] << 8;
453 a->pbn |= buf[++idx];
456 for (i = 0; i < a->number_sdp_streams; i++) {
457 a->sdp_stream_sink[i] =
458 (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf;
462 case DP_QUERY_PAYLOAD:
463 req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf;
464 WARN_ON(buf[++idx] & 0x80);
465 req->u.query_payload.vcpi = buf[idx] & 0x7f;
467 case DP_REMOTE_DPCD_READ:
469 struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read;
471 r->port_number = (buf[idx] >> 4) & 0xf;
473 r->dpcd_address = (buf[idx] << 16) & 0xf0000;
474 r->dpcd_address |= (buf[++idx] << 8) & 0xff00;
475 r->dpcd_address |= buf[++idx] & 0xff;
477 r->num_bytes = buf[++idx];
480 case DP_REMOTE_DPCD_WRITE:
482 struct drm_dp_remote_dpcd_write *w =
485 w->port_number = (buf[idx] >> 4) & 0xf;
487 w->dpcd_address = (buf[idx] << 16) & 0xf0000;
488 w->dpcd_address |= (buf[++idx] << 8) & 0xff00;
489 w->dpcd_address |= buf[++idx] & 0xff;
491 w->num_bytes = buf[++idx];
493 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
499 case DP_REMOTE_I2C_READ:
501 struct drm_dp_remote_i2c_read *r = &req->u.i2c_read;
502 struct drm_dp_remote_i2c_read_tx *tx;
505 r->num_transactions = buf[idx] & 0x3;
506 r->port_number = (buf[idx] >> 4) & 0xf;
507 for (i = 0; i < r->num_transactions; i++) {
508 tx = &r->transactions[i];
510 tx->i2c_dev_id = buf[++idx] & 0x7f;
511 tx->num_bytes = buf[++idx];
512 tx->bytes = kmemdup(&buf[++idx],
519 idx += tx->num_bytes;
520 tx->no_stop_bit = (buf[idx] >> 5) & 0x1;
521 tx->i2c_transaction_delay = buf[idx] & 0xf;
525 for (i = 0; i < r->num_transactions; i++) {
526 tx = &r->transactions[i];
532 r->read_i2c_device_id = buf[++idx] & 0x7f;
533 r->num_bytes_read = buf[++idx];
536 case DP_REMOTE_I2C_WRITE:
538 struct drm_dp_remote_i2c_write *w = &req->u.i2c_write;
540 w->port_number = (buf[idx] >> 4) & 0xf;
541 w->write_i2c_device_id = buf[++idx] & 0x7f;
542 w->num_bytes = buf[++idx];
543 w->bytes = kmemdup(&buf[++idx], w->num_bytes,
553 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req);
556 drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req,
557 int indent, struct drm_printer *printer)
561 #define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__)
562 if (req->req_type == DP_LINK_ADDRESS) {
563 /* No contents to print */
564 P("type=%s\n", drm_dp_mst_req_type_str(req->req_type));
568 P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type));
571 switch (req->req_type) {
572 case DP_ENUM_PATH_RESOURCES:
573 case DP_POWER_DOWN_PHY:
574 case DP_POWER_UP_PHY:
575 P("port=%d\n", req->u.port_num.port_number);
577 case DP_ALLOCATE_PAYLOAD:
578 P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n",
579 req->u.allocate_payload.port_number,
580 req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn,
581 req->u.allocate_payload.number_sdp_streams,
582 req->u.allocate_payload.number_sdp_streams,
583 req->u.allocate_payload.sdp_stream_sink);
585 case DP_QUERY_PAYLOAD:
586 P("port=%d vcpi=%d\n",
587 req->u.query_payload.port_number,
588 req->u.query_payload.vcpi);
590 case DP_REMOTE_DPCD_READ:
591 P("port=%d dpcd_addr=%05x len=%d\n",
592 req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address,
593 req->u.dpcd_read.num_bytes);
595 case DP_REMOTE_DPCD_WRITE:
596 P("port=%d addr=%05x len=%d: %*ph\n",
597 req->u.dpcd_write.port_number,
598 req->u.dpcd_write.dpcd_address,
599 req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes,
600 req->u.dpcd_write.bytes);
602 case DP_REMOTE_I2C_READ:
603 P("port=%d num_tx=%d id=%d size=%d:\n",
604 req->u.i2c_read.port_number,
605 req->u.i2c_read.num_transactions,
606 req->u.i2c_read.read_i2c_device_id,
607 req->u.i2c_read.num_bytes_read);
610 for (i = 0; i < req->u.i2c_read.num_transactions; i++) {
611 const struct drm_dp_remote_i2c_read_tx *rtx =
612 &req->u.i2c_read.transactions[i];
614 P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n",
615 i, rtx->i2c_dev_id, rtx->num_bytes,
616 rtx->no_stop_bit, rtx->i2c_transaction_delay,
617 rtx->num_bytes, rtx->bytes);
620 case DP_REMOTE_I2C_WRITE:
621 P("port=%d id=%d size=%d: %*ph\n",
622 req->u.i2c_write.port_number,
623 req->u.i2c_write.write_i2c_device_id,
624 req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes,
625 req->u.i2c_write.bytes);
633 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body);
636 drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p,
637 const struct drm_dp_sideband_msg_tx *txmsg)
639 struct drm_dp_sideband_msg_req_body req;
644 drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf,
646 drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n",
647 txmsg->cur_offset, txmsg->cur_len, txmsg->seqno,
648 drm_dp_mst_sideband_tx_state_str(txmsg->state),
649 txmsg->path_msg, buf);
651 ret = drm_dp_decode_sideband_req(txmsg, &req);
653 drm_printf(p, "<failed to decode sideband req: %d>\n", ret);
656 drm_dp_dump_sideband_msg_req_body(&req, 1, p);
658 switch (req.req_type) {
659 case DP_REMOTE_DPCD_WRITE:
660 kfree(req.u.dpcd_write.bytes);
662 case DP_REMOTE_I2C_READ:
663 for (i = 0; i < req.u.i2c_read.num_transactions; i++)
664 kfree(req.u.i2c_read.transactions[i].bytes);
666 case DP_REMOTE_I2C_WRITE:
667 kfree(req.u.i2c_write.bytes);
672 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
675 crc4 = drm_dp_msg_data_crc4(msg, len);
679 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
680 struct drm_dp_sideband_msg_tx *raw)
685 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
690 /* this adds a chunk of msg to the builder to get the final msg */
691 static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
692 u8 *replybuf, u8 replybuflen, bool hdr)
699 struct drm_dp_sideband_msg_hdr recv_hdr;
700 ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
702 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
707 * ignore out-of-order messages or messages that are part of a
710 if (!recv_hdr.somt && !msg->have_somt)
713 /* get length contained in this portion */
714 msg->curchunk_len = recv_hdr.msg_len;
715 msg->curchunk_hdrlen = hdrlen;
717 /* we have already gotten an somt - don't bother parsing */
718 if (recv_hdr.somt && msg->have_somt)
722 memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
723 msg->have_somt = true;
726 msg->have_eomt = true;
728 /* copy the bytes for the remainder of this header chunk */
729 msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
730 memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
732 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
733 msg->curchunk_idx += replybuflen;
736 if (msg->curchunk_idx >= msg->curchunk_len) {
738 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
739 /* copy chunk into bigger msg */
740 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
741 msg->curlen += msg->curchunk_len - 1;
746 static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
747 struct drm_dp_sideband_msg_reply_body *repmsg)
751 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
753 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
755 if (idx > raw->curlen)
757 for (i = 0; i < repmsg->u.link_addr.nports; i++) {
758 if (raw->msg[idx] & 0x80)
759 repmsg->u.link_addr.ports[i].input_port = 1;
761 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
762 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
765 if (idx > raw->curlen)
767 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
768 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
769 if (repmsg->u.link_addr.ports[i].input_port == 0)
770 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
772 if (idx > raw->curlen)
774 if (repmsg->u.link_addr.ports[i].input_port == 0) {
775 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
777 if (idx > raw->curlen)
779 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
781 if (idx > raw->curlen)
783 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
784 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
788 if (idx > raw->curlen)
794 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
798 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
799 struct drm_dp_sideband_msg_reply_body *repmsg)
802 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
804 if (idx > raw->curlen)
806 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
808 if (idx > raw->curlen)
811 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
814 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
818 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
819 struct drm_dp_sideband_msg_reply_body *repmsg)
822 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
824 if (idx > raw->curlen)
828 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
832 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
833 struct drm_dp_sideband_msg_reply_body *repmsg)
837 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
839 if (idx > raw->curlen)
841 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
844 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
847 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
851 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
852 struct drm_dp_sideband_msg_reply_body *repmsg)
855 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
857 if (idx > raw->curlen)
859 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
861 if (idx > raw->curlen)
863 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
865 if (idx > raw->curlen)
869 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
873 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
874 struct drm_dp_sideband_msg_reply_body *repmsg)
877 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
879 if (idx > raw->curlen)
881 repmsg->u.allocate_payload.vcpi = raw->msg[idx];
883 if (idx > raw->curlen)
885 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
887 if (idx > raw->curlen)
891 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
895 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
896 struct drm_dp_sideband_msg_reply_body *repmsg)
899 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
901 if (idx > raw->curlen)
903 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
905 if (idx > raw->curlen)
909 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
913 static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
914 struct drm_dp_sideband_msg_reply_body *repmsg)
918 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
920 if (idx > raw->curlen) {
921 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
928 static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
929 struct drm_dp_sideband_msg_reply_body *msg)
931 memset(msg, 0, sizeof(*msg));
932 msg->reply_type = (raw->msg[0] & 0x80) >> 7;
933 msg->req_type = (raw->msg[0] & 0x7f);
935 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) {
936 memcpy(msg->u.nak.guid, &raw->msg[1], 16);
937 msg->u.nak.reason = raw->msg[17];
938 msg->u.nak.nak_data = raw->msg[18];
942 switch (msg->req_type) {
943 case DP_LINK_ADDRESS:
944 return drm_dp_sideband_parse_link_address(raw, msg);
945 case DP_QUERY_PAYLOAD:
946 return drm_dp_sideband_parse_query_payload_ack(raw, msg);
947 case DP_REMOTE_DPCD_READ:
948 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
949 case DP_REMOTE_DPCD_WRITE:
950 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
951 case DP_REMOTE_I2C_READ:
952 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
953 case DP_ENUM_PATH_RESOURCES:
954 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
955 case DP_ALLOCATE_PAYLOAD:
956 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
957 case DP_POWER_DOWN_PHY:
958 case DP_POWER_UP_PHY:
959 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
960 case DP_CLEAR_PAYLOAD_ID_TABLE:
961 return true; /* since there's nothing to parse */
963 DRM_ERROR("Got unknown reply 0x%02x (%s)\n", msg->req_type,
964 drm_dp_mst_req_type_str(msg->req_type));
969 static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
970 struct drm_dp_sideband_msg_req_body *msg)
974 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
976 if (idx > raw->curlen)
979 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
981 if (idx > raw->curlen)
984 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
985 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
986 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
987 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
988 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
992 DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
996 static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
997 struct drm_dp_sideband_msg_req_body *msg)
1001 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
1003 if (idx > raw->curlen)
1006 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
1008 if (idx > raw->curlen)
1011 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
1015 DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
1019 static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
1020 struct drm_dp_sideband_msg_req_body *msg)
1022 memset(msg, 0, sizeof(*msg));
1023 msg->req_type = (raw->msg[0] & 0x7f);
1025 switch (msg->req_type) {
1026 case DP_CONNECTION_STATUS_NOTIFY:
1027 return drm_dp_sideband_parse_connection_status_notify(raw, msg);
1028 case DP_RESOURCE_STATUS_NOTIFY:
1029 return drm_dp_sideband_parse_resource_status_notify(raw, msg);
1031 DRM_ERROR("Got unknown request 0x%02x (%s)\n", msg->req_type,
1032 drm_dp_mst_req_type_str(msg->req_type));
1037 static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
1039 struct drm_dp_sideband_msg_req_body req;
1041 req.req_type = DP_REMOTE_DPCD_WRITE;
1042 req.u.dpcd_write.port_number = port_num;
1043 req.u.dpcd_write.dpcd_address = offset;
1044 req.u.dpcd_write.num_bytes = num_bytes;
1045 req.u.dpcd_write.bytes = bytes;
1046 drm_dp_encode_sideband_req(&req, msg);
1051 static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
1053 struct drm_dp_sideband_msg_req_body req;
1055 req.req_type = DP_LINK_ADDRESS;
1056 drm_dp_encode_sideband_req(&req, msg);
1060 static int build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg)
1062 struct drm_dp_sideband_msg_req_body req;
1064 req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE;
1065 drm_dp_encode_sideband_req(&req, msg);
1069 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
1071 struct drm_dp_sideband_msg_req_body req;
1073 req.req_type = DP_ENUM_PATH_RESOURCES;
1074 req.u.port_num.port_number = port_num;
1075 drm_dp_encode_sideband_req(&req, msg);
1076 msg->path_msg = true;
1080 static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
1081 u8 vcpi, uint16_t pbn,
1082 u8 number_sdp_streams,
1083 u8 *sdp_stream_sink)
1085 struct drm_dp_sideband_msg_req_body req;
1086 memset(&req, 0, sizeof(req));
1087 req.req_type = DP_ALLOCATE_PAYLOAD;
1088 req.u.allocate_payload.port_number = port_num;
1089 req.u.allocate_payload.vcpi = vcpi;
1090 req.u.allocate_payload.pbn = pbn;
1091 req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
1092 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
1093 number_sdp_streams);
1094 drm_dp_encode_sideband_req(&req, msg);
1095 msg->path_msg = true;
1099 static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
1100 int port_num, bool power_up)
1102 struct drm_dp_sideband_msg_req_body req;
1105 req.req_type = DP_POWER_UP_PHY;
1107 req.req_type = DP_POWER_DOWN_PHY;
1109 req.u.port_num.port_number = port_num;
1110 drm_dp_encode_sideband_req(&req, msg);
1111 msg->path_msg = true;
1115 static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1116 struct drm_dp_vcpi *vcpi)
1120 mutex_lock(&mgr->payload_lock);
1121 ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
1122 if (ret > mgr->max_payloads) {
1124 DRM_DEBUG_KMS("out of payload ids %d\n", ret);
1128 vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
1129 if (vcpi_ret > mgr->max_payloads) {
1131 DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
1135 set_bit(ret, &mgr->payload_mask);
1136 set_bit(vcpi_ret, &mgr->vcpi_mask);
1137 vcpi->vcpi = vcpi_ret + 1;
1138 mgr->proposed_vcpis[ret - 1] = vcpi;
1140 mutex_unlock(&mgr->payload_lock);
1144 static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
1151 mutex_lock(&mgr->payload_lock);
1152 DRM_DEBUG_KMS("putting payload %d\n", vcpi);
1153 clear_bit(vcpi - 1, &mgr->vcpi_mask);
1155 for (i = 0; i < mgr->max_payloads; i++) {
1156 if (mgr->proposed_vcpis[i] &&
1157 mgr->proposed_vcpis[i]->vcpi == vcpi) {
1158 mgr->proposed_vcpis[i] = NULL;
1159 clear_bit(i + 1, &mgr->payload_mask);
1162 mutex_unlock(&mgr->payload_lock);
1165 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
1166 struct drm_dp_sideband_msg_tx *txmsg)
1171 * All updates to txmsg->state are protected by mgr->qlock, and the two
1172 * cases we check here are terminal states. For those the barriers
1173 * provided by the wake_up/wait_event pair are enough.
1175 state = READ_ONCE(txmsg->state);
1176 return (state == DRM_DP_SIDEBAND_TX_RX ||
1177 state == DRM_DP_SIDEBAND_TX_TIMEOUT);
1180 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
1181 struct drm_dp_sideband_msg_tx *txmsg)
1183 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1186 ret = wait_event_timeout(mgr->tx_waitq,
1187 check_txmsg_state(mgr, txmsg),
1189 mutex_lock(&mstb->mgr->qlock);
1191 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
1196 DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
1198 /* dump some state */
1202 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
1203 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
1204 list_del(&txmsg->next);
1207 if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
1208 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
1209 mstb->tx_slots[txmsg->seqno] = NULL;
1213 if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) {
1214 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1216 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
1218 mutex_unlock(&mgr->qlock);
1223 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
1225 struct drm_dp_mst_branch *mstb;
1227 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
1233 memcpy(mstb->rad, rad, lct / 2);
1234 INIT_LIST_HEAD(&mstb->ports);
1235 kref_init(&mstb->topology_kref);
1236 kref_init(&mstb->malloc_kref);
1240 static void drm_dp_free_mst_branch_device(struct kref *kref)
1242 struct drm_dp_mst_branch *mstb =
1243 container_of(kref, struct drm_dp_mst_branch, malloc_kref);
1245 if (mstb->port_parent)
1246 drm_dp_mst_put_port_malloc(mstb->port_parent);
1252 * DOC: Branch device and port refcounting
1254 * Topology refcount overview
1255 * ~~~~~~~~~~~~~~~~~~~~~~~~~~
1257 * The refcounting schemes for &struct drm_dp_mst_branch and &struct
1258 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have
1259 * two different kinds of refcounts: topology refcounts, and malloc refcounts.
1261 * Topology refcounts are not exposed to drivers, and are handled internally
1262 * by the DP MST helpers. The helpers use them in order to prevent the
1263 * in-memory topology state from being changed in the middle of critical
1264 * operations like changing the internal state of payload allocations. This
1265 * means each branch and port will be considered to be connected to the rest
1266 * of the topology until its topology refcount reaches zero. Additionally,
1267 * for ports this means that their associated &struct drm_connector will stay
1268 * registered with userspace until the port's refcount reaches 0.
1270 * Malloc refcount overview
1271 * ~~~~~~~~~~~~~~~~~~~~~~~~
1273 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct
1274 * drm_dp_mst_branch allocated even after all of its topology references have
1275 * been dropped, so that the driver or MST helpers can safely access each
1276 * branch's last known state before it was disconnected from the topology.
1277 * When the malloc refcount of a port or branch reaches 0, the memory
1278 * allocation containing the &struct drm_dp_mst_branch or &struct
1279 * drm_dp_mst_port respectively will be freed.
1281 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed
1282 * to drivers. As of writing this documentation, there are no drivers that
1283 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST
1284 * helpers. Exposing this API to drivers in a race-free manner would take more
1285 * tweaking of the refcounting scheme, however patches are welcome provided
1286 * there is a legitimate driver usecase for this.
1288 * Refcount relationships in a topology
1289 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1291 * Let's take a look at why the relationship between topology and malloc
1292 * refcounts is designed the way it is.
1294 * .. kernel-figure:: dp-mst/topology-figure-1.dot
1296 * An example of topology and malloc refs in a DP MST topology with two
1297 * active payloads. Topology refcount increments are indicated by solid
1298 * lines, and malloc refcount increments are indicated by dashed lines.
1299 * Each starts from the branch which incremented the refcount, and ends at
1300 * the branch to which the refcount belongs to, i.e. the arrow points the
1301 * same way as the C pointers used to reference a structure.
1303 * As you can see in the above figure, every branch increments the topology
1304 * refcount of its children, and increments the malloc refcount of its
1305 * parent. Additionally, every payload increments the malloc refcount of its
1306 * assigned port by 1.
1308 * So, what would happen if MSTB #3 from the above figure was unplugged from
1309 * the system, but the driver hadn't yet removed payload #2 from port #3? The
1310 * topology would start to look like the figure below.
1312 * .. kernel-figure:: dp-mst/topology-figure-2.dot
1314 * Ports and branch devices which have been released from memory are
1315 * colored grey, and references which have been removed are colored red.
1317 * Whenever a port or branch device's topology refcount reaches zero, it will
1318 * decrement the topology refcounts of all its children, the malloc refcount
1319 * of its parent, and finally its own malloc refcount. For MSTB #4 and port
1320 * #4, this means they both have been disconnected from the topology and freed
1321 * from memory. But, because payload #2 is still holding a reference to port
1322 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port
1323 * is still accessible from memory. This also means port #3 has not yet
1324 * decremented the malloc refcount of MSTB #3, so its &struct
1325 * drm_dp_mst_branch will also stay allocated in memory until port #3's
1326 * malloc refcount reaches 0.
1328 * This relationship is necessary because in order to release payload #2, we
1329 * need to be able to figure out the last relative of port #3 that's still
1330 * connected to the topology. In this case, we would travel up the topology as
1333 * .. kernel-figure:: dp-mst/topology-figure-3.dot
1335 * And finally, remove payload #2 by communicating with port #2 through
1336 * sideband transactions.
1340 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch
1342 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of
1344 * Increments &drm_dp_mst_branch.malloc_kref. When
1345 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1346 * will be released and @mstb may no longer be used.
1348 * See also: drm_dp_mst_put_mstb_malloc()
1351 drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb)
1353 kref_get(&mstb->malloc_kref);
1354 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref));
1358 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch
1360 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of
1362 * Decrements &drm_dp_mst_branch.malloc_kref. When
1363 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb
1364 * will be released and @mstb may no longer be used.
1366 * See also: drm_dp_mst_get_mstb_malloc()
1369 drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb)
1371 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1);
1372 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device);
1375 static void drm_dp_free_mst_port(struct kref *kref)
1377 struct drm_dp_mst_port *port =
1378 container_of(kref, struct drm_dp_mst_port, malloc_kref);
1380 drm_dp_mst_put_mstb_malloc(port->parent);
1385 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port
1386 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of
1388 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1389 * reaches 0, the memory allocation for @port will be released and @port may
1390 * no longer be used.
1392 * Because @port could potentially be freed at any time by the DP MST helpers
1393 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this
1394 * function, drivers that which to make use of &struct drm_dp_mst_port should
1395 * ensure that they grab at least one main malloc reference to their MST ports
1396 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before
1397 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0.
1399 * See also: drm_dp_mst_put_port_malloc()
1402 drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port)
1404 kref_get(&port->malloc_kref);
1405 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref));
1407 EXPORT_SYMBOL(drm_dp_mst_get_port_malloc);
1410 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port
1411 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of
1413 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref
1414 * reaches 0, the memory allocation for @port will be released and @port may
1415 * no longer be used.
1417 * See also: drm_dp_mst_get_port_malloc()
1420 drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port)
1422 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1);
1423 kref_put(&port->malloc_kref, drm_dp_free_mst_port);
1425 EXPORT_SYMBOL(drm_dp_mst_put_port_malloc);
1427 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
1429 #define STACK_DEPTH 8
1431 static noinline void
1432 __topology_ref_save(struct drm_dp_mst_topology_mgr *mgr,
1433 struct drm_dp_mst_topology_ref_history *history,
1434 enum drm_dp_mst_topology_ref_type type)
1436 struct drm_dp_mst_topology_ref_entry *entry = NULL;
1437 depot_stack_handle_t backtrace;
1438 ulong stack_entries[STACK_DEPTH];
1442 n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1);
1443 backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL);
1447 /* Try to find an existing entry for this backtrace */
1448 for (i = 0; i < history->len; i++) {
1449 if (history->entries[i].backtrace == backtrace) {
1450 entry = &history->entries[i];
1455 /* Otherwise add one */
1457 struct drm_dp_mst_topology_ref_entry *new;
1458 int new_len = history->len + 1;
1460 new = krealloc(history->entries, sizeof(*new) * new_len,
1465 entry = &new[history->len];
1466 history->len = new_len;
1467 history->entries = new;
1469 entry->backtrace = backtrace;
1474 entry->ts_nsec = ktime_get_ns();
1478 topology_ref_history_cmp(const void *a, const void *b)
1480 const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b;
1482 if (entry_a->ts_nsec > entry_b->ts_nsec)
1484 else if (entry_a->ts_nsec < entry_b->ts_nsec)
1490 static inline const char *
1491 topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type)
1493 if (type == DRM_DP_MST_TOPOLOGY_REF_GET)
1500 __dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history,
1501 void *ptr, const char *type_str)
1503 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
1504 char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL);
1513 /* First, sort the list so that it goes from oldest to newest
1516 sort(history->entries, history->len, sizeof(*history->entries),
1517 topology_ref_history_cmp, NULL);
1519 drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n",
1522 for (i = 0; i < history->len; i++) {
1523 const struct drm_dp_mst_topology_ref_entry *entry =
1524 &history->entries[i];
1527 u64 ts_nsec = entry->ts_nsec;
1528 u32 rem_nsec = do_div(ts_nsec, 1000000000);
1530 nr_entries = stack_depot_fetch(entry->backtrace, &entries);
1531 stack_trace_snprint(buf, PAGE_SIZE, entries, nr_entries, 4);
1533 drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s",
1535 topology_ref_type_to_str(entry->type),
1536 ts_nsec, rem_nsec / 1000, buf);
1539 /* Now free the history, since this is the only time we expose it */
1540 kfree(history->entries);
1545 static __always_inline void
1546 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb)
1548 __dump_topology_ref_history(&mstb->topology_ref_history, mstb,
1552 static __always_inline void
1553 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port)
1555 __dump_topology_ref_history(&port->topology_ref_history, port,
1559 static __always_inline void
1560 save_mstb_topology_ref(struct drm_dp_mst_branch *mstb,
1561 enum drm_dp_mst_topology_ref_type type)
1563 __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type);
1566 static __always_inline void
1567 save_port_topology_ref(struct drm_dp_mst_port *port,
1568 enum drm_dp_mst_topology_ref_type type)
1570 __topology_ref_save(port->mgr, &port->topology_ref_history, type);
1574 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr)
1576 mutex_lock(&mgr->topology_ref_history_lock);
1580 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr)
1582 mutex_unlock(&mgr->topology_ref_history_lock);
1586 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {}
1588 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {}
1590 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {}
1592 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {}
1593 #define save_mstb_topology_ref(mstb, type)
1594 #define save_port_topology_ref(port, type)
1597 static void drm_dp_destroy_mst_branch_device(struct kref *kref)
1599 struct drm_dp_mst_branch *mstb =
1600 container_of(kref, struct drm_dp_mst_branch, topology_kref);
1601 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
1603 drm_dp_mst_dump_mstb_topology_history(mstb);
1605 INIT_LIST_HEAD(&mstb->destroy_next);
1608 * This can get called under mgr->mutex, so we need to perform the
1609 * actual destruction of the mstb in another worker
1611 mutex_lock(&mgr->delayed_destroy_lock);
1612 list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list);
1613 mutex_unlock(&mgr->delayed_destroy_lock);
1614 schedule_work(&mgr->delayed_destroy_work);
1618 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a
1619 * branch device unless it's zero
1620 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of
1622 * Attempts to grab a topology reference to @mstb, if it hasn't yet been
1623 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has
1624 * reached 0). Holding a topology reference implies that a malloc reference
1625 * will be held to @mstb as long as the user holds the topology reference.
1627 * Care should be taken to ensure that the user has at least one malloc
1628 * reference to @mstb. If you already have a topology reference to @mstb, you
1629 * should use drm_dp_mst_topology_get_mstb() instead.
1632 * drm_dp_mst_topology_get_mstb()
1633 * drm_dp_mst_topology_put_mstb()
1636 * * 1: A topology reference was grabbed successfully
1637 * * 0: @port is no longer in the topology, no reference was grabbed
1639 static int __must_check
1640 drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb)
1644 topology_ref_history_lock(mstb->mgr);
1645 ret = kref_get_unless_zero(&mstb->topology_kref);
1647 DRM_DEBUG("mstb %p (%d)\n",
1648 mstb, kref_read(&mstb->topology_kref));
1649 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1652 topology_ref_history_unlock(mstb->mgr);
1658 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a
1660 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of
1662 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or
1663 * not it's already reached 0. This is only valid to use in scenarios where
1664 * you are already guaranteed to have at least one active topology reference
1665 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used.
1668 * drm_dp_mst_topology_try_get_mstb()
1669 * drm_dp_mst_topology_put_mstb()
1671 static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb)
1673 topology_ref_history_lock(mstb->mgr);
1675 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET);
1676 WARN_ON(kref_read(&mstb->topology_kref) == 0);
1677 kref_get(&mstb->topology_kref);
1678 DRM_DEBUG("mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref));
1680 topology_ref_history_unlock(mstb->mgr);
1684 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch
1686 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from
1688 * Releases a topology reference from @mstb by decrementing
1689 * &drm_dp_mst_branch.topology_kref.
1692 * drm_dp_mst_topology_try_get_mstb()
1693 * drm_dp_mst_topology_get_mstb()
1696 drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb)
1698 topology_ref_history_lock(mstb->mgr);
1700 DRM_DEBUG("mstb %p (%d)\n",
1701 mstb, kref_read(&mstb->topology_kref) - 1);
1702 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT);
1704 topology_ref_history_unlock(mstb->mgr);
1705 kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device);
1708 static void drm_dp_destroy_port(struct kref *kref)
1710 struct drm_dp_mst_port *port =
1711 container_of(kref, struct drm_dp_mst_port, topology_kref);
1712 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1714 drm_dp_mst_dump_port_topology_history(port);
1716 /* There's nothing that needs locking to destroy an input port yet */
1718 drm_dp_mst_put_port_malloc(port);
1722 kfree(port->cached_edid);
1725 * we can't destroy the connector here, as we might be holding the
1726 * mode_config.mutex from an EDID retrieval
1728 mutex_lock(&mgr->delayed_destroy_lock);
1729 list_add(&port->next, &mgr->destroy_port_list);
1730 mutex_unlock(&mgr->delayed_destroy_lock);
1731 schedule_work(&mgr->delayed_destroy_work);
1735 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a
1736 * port unless it's zero
1737 * @port: &struct drm_dp_mst_port to increment the topology refcount of
1739 * Attempts to grab a topology reference to @port, if it hasn't yet been
1740 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached
1741 * 0). Holding a topology reference implies that a malloc reference will be
1742 * held to @port as long as the user holds the topology reference.
1744 * Care should be taken to ensure that the user has at least one malloc
1745 * reference to @port. If you already have a topology reference to @port, you
1746 * should use drm_dp_mst_topology_get_port() instead.
1749 * drm_dp_mst_topology_get_port()
1750 * drm_dp_mst_topology_put_port()
1753 * * 1: A topology reference was grabbed successfully
1754 * * 0: @port is no longer in the topology, no reference was grabbed
1756 static int __must_check
1757 drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port)
1761 topology_ref_history_lock(port->mgr);
1762 ret = kref_get_unless_zero(&port->topology_kref);
1764 DRM_DEBUG("port %p (%d)\n",
1765 port, kref_read(&port->topology_kref));
1766 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1769 topology_ref_history_unlock(port->mgr);
1774 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port
1775 * @port: The &struct drm_dp_mst_port to increment the topology refcount of
1777 * Increments &drm_dp_mst_port.topology_refcount without checking whether or
1778 * not it's already reached 0. This is only valid to use in scenarios where
1779 * you are already guaranteed to have at least one active topology reference
1780 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used.
1783 * drm_dp_mst_topology_try_get_port()
1784 * drm_dp_mst_topology_put_port()
1786 static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port)
1788 topology_ref_history_lock(port->mgr);
1790 WARN_ON(kref_read(&port->topology_kref) == 0);
1791 kref_get(&port->topology_kref);
1792 DRM_DEBUG("port %p (%d)\n", port, kref_read(&port->topology_kref));
1793 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET);
1795 topology_ref_history_unlock(port->mgr);
1799 * drm_dp_mst_topology_put_port() - release a topology reference to a port
1800 * @port: The &struct drm_dp_mst_port to release the topology reference from
1802 * Releases a topology reference from @port by decrementing
1803 * &drm_dp_mst_port.topology_kref.
1806 * drm_dp_mst_topology_try_get_port()
1807 * drm_dp_mst_topology_get_port()
1809 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port)
1811 topology_ref_history_lock(port->mgr);
1813 DRM_DEBUG("port %p (%d)\n",
1814 port, kref_read(&port->topology_kref) - 1);
1815 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT);
1817 topology_ref_history_unlock(port->mgr);
1818 kref_put(&port->topology_kref, drm_dp_destroy_port);
1821 static struct drm_dp_mst_branch *
1822 drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb,
1823 struct drm_dp_mst_branch *to_find)
1825 struct drm_dp_mst_port *port;
1826 struct drm_dp_mst_branch *rmstb;
1828 if (to_find == mstb)
1831 list_for_each_entry(port, &mstb->ports, next) {
1833 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1834 port->mstb, to_find);
1842 static struct drm_dp_mst_branch *
1843 drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr,
1844 struct drm_dp_mst_branch *mstb)
1846 struct drm_dp_mst_branch *rmstb = NULL;
1848 mutex_lock(&mgr->lock);
1849 if (mgr->mst_primary) {
1850 rmstb = drm_dp_mst_topology_get_mstb_validated_locked(
1851 mgr->mst_primary, mstb);
1853 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb))
1856 mutex_unlock(&mgr->lock);
1860 static struct drm_dp_mst_port *
1861 drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb,
1862 struct drm_dp_mst_port *to_find)
1864 struct drm_dp_mst_port *port, *mport;
1866 list_for_each_entry(port, &mstb->ports, next) {
1867 if (port == to_find)
1871 mport = drm_dp_mst_topology_get_port_validated_locked(
1872 port->mstb, to_find);
1880 static struct drm_dp_mst_port *
1881 drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr,
1882 struct drm_dp_mst_port *port)
1884 struct drm_dp_mst_port *rport = NULL;
1886 mutex_lock(&mgr->lock);
1887 if (mgr->mst_primary) {
1888 rport = drm_dp_mst_topology_get_port_validated_locked(
1889 mgr->mst_primary, port);
1891 if (rport && !drm_dp_mst_topology_try_get_port(rport))
1894 mutex_unlock(&mgr->lock);
1898 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
1900 struct drm_dp_mst_port *port;
1903 list_for_each_entry(port, &mstb->ports, next) {
1904 if (port->port_num == port_num) {
1905 ret = drm_dp_mst_topology_try_get_port(port);
1906 return ret ? port : NULL;
1914 * calculate a new RAD for this MST branch device
1915 * if parent has an LCT of 2 then it has 1 nibble of RAD,
1916 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1918 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1921 int parent_lct = port->parent->lct;
1923 int idx = (parent_lct - 1) / 2;
1924 if (parent_lct > 1) {
1925 memcpy(rad, port->parent->rad, idx + 1);
1926 shift = (parent_lct % 2) ? 4 : 0;
1930 rad[idx] |= port->port_num << shift;
1931 return parent_lct + 1;
1934 static int drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt)
1936 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
1937 struct drm_dp_mst_branch *mstb;
1941 if (port->pdt == new_pdt)
1944 /* Teardown the old pdt, if there is one */
1945 switch (port->pdt) {
1946 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1947 case DP_PEER_DEVICE_SST_SINK:
1949 * If the new PDT would also have an i2c bus, don't bother
1950 * with reregistering it
1952 if (new_pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
1953 new_pdt == DP_PEER_DEVICE_SST_SINK) {
1954 port->pdt = new_pdt;
1958 /* remove i2c over sideband */
1959 drm_dp_mst_unregister_i2c_bus(&port->aux);
1961 case DP_PEER_DEVICE_MST_BRANCHING:
1962 mutex_lock(&mgr->lock);
1963 drm_dp_mst_topology_put_mstb(port->mstb);
1965 mutex_unlock(&mgr->lock);
1969 port->pdt = new_pdt;
1970 switch (port->pdt) {
1971 case DP_PEER_DEVICE_DP_LEGACY_CONV:
1972 case DP_PEER_DEVICE_SST_SINK:
1973 /* add i2c over sideband */
1974 ret = drm_dp_mst_register_i2c_bus(&port->aux);
1977 case DP_PEER_DEVICE_MST_BRANCHING:
1978 lct = drm_dp_calculate_rad(port, rad);
1979 mstb = drm_dp_add_mst_branch_device(lct, rad);
1982 DRM_ERROR("Failed to create MSTB for port %p", port);
1986 mutex_lock(&mgr->lock);
1988 mstb->mgr = port->mgr;
1989 mstb->port_parent = port;
1992 * Make sure this port's memory allocation stays
1993 * around until its child MSTB releases it
1995 drm_dp_mst_get_port_malloc(port);
1996 mutex_unlock(&mgr->lock);
1998 /* And make sure we send a link address for this */
2005 port->pdt = DP_PEER_DEVICE_NONE;
2010 * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband
2011 * @aux: Fake sideband AUX CH
2012 * @offset: address of the (first) register to read
2013 * @buffer: buffer to store the register values
2014 * @size: number of bytes in @buffer
2016 * Performs the same functionality for remote devices via
2017 * sideband messaging as drm_dp_dpcd_read() does for local
2018 * devices via actual AUX CH.
2020 * Return: Number of bytes read, or negative error code on failure.
2022 ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux,
2023 unsigned int offset, void *buffer, size_t size)
2025 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2028 return drm_dp_send_dpcd_read(port->mgr, port,
2029 offset, size, buffer);
2033 * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband
2034 * @aux: Fake sideband AUX CH
2035 * @offset: address of the (first) register to write
2036 * @buffer: buffer containing the values to write
2037 * @size: number of bytes in @buffer
2039 * Performs the same functionality for remote devices via
2040 * sideband messaging as drm_dp_dpcd_write() does for local
2041 * devices via actual AUX CH.
2043 * Return: 0 on success, negative error code on failure.
2045 ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux,
2046 unsigned int offset, void *buffer, size_t size)
2048 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port,
2051 return drm_dp_send_dpcd_write(port->mgr, port,
2052 offset, size, buffer);
2055 static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
2059 memcpy(mstb->guid, guid, 16);
2061 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
2062 if (mstb->port_parent) {
2063 ret = drm_dp_send_dpcd_write(
2071 ret = drm_dp_dpcd_write(
2080 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
2083 size_t proppath_size)
2087 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
2088 for (i = 0; i < (mstb->lct - 1); i++) {
2089 int shift = (i % 2) ? 0 : 4;
2090 int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
2091 snprintf(temp, sizeof(temp), "-%d", port_num);
2092 strlcat(proppath, temp, proppath_size);
2094 snprintf(temp, sizeof(temp), "-%d", pnum);
2095 strlcat(proppath, temp, proppath_size);
2099 * drm_dp_mst_connector_late_register() - Late MST connector registration
2100 * @connector: The MST connector
2101 * @port: The MST port for this connector
2103 * Helper to register the remote aux device for this MST port. Drivers should
2104 * call this from their mst connector's late_register hook to enable MST aux
2107 * Return: 0 on success, negative error code on failure.
2109 int drm_dp_mst_connector_late_register(struct drm_connector *connector,
2110 struct drm_dp_mst_port *port)
2112 DRM_DEBUG_KMS("registering %s remote bus for %s\n",
2113 port->aux.name, connector->kdev->kobj.name);
2115 port->aux.dev = connector->kdev;
2116 return drm_dp_aux_register_devnode(&port->aux);
2118 EXPORT_SYMBOL(drm_dp_mst_connector_late_register);
2121 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration
2122 * @connector: The MST connector
2123 * @port: The MST port for this connector
2125 * Helper to unregister the remote aux device for this MST port, registered by
2126 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst
2127 * connector's early_unregister hook.
2129 void drm_dp_mst_connector_early_unregister(struct drm_connector *connector,
2130 struct drm_dp_mst_port *port)
2132 DRM_DEBUG_KMS("unregistering %s remote bus for %s\n",
2133 port->aux.name, connector->kdev->kobj.name);
2134 drm_dp_aux_unregister_devnode(&port->aux);
2136 EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister);
2139 drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb,
2140 struct drm_dp_mst_port *port)
2142 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
2146 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
2147 port->connector = mgr->cbs->add_connector(mgr, port, proppath);
2148 if (!port->connector) {
2153 if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
2154 port->pdt == DP_PEER_DEVICE_SST_SINK) &&
2155 port->port_num >= DP_MST_LOGICAL_PORT_0) {
2156 port->cached_edid = drm_get_edid(port->connector,
2158 drm_connector_set_tile_property(port->connector);
2161 mgr->cbs->register_connector(port->connector);
2165 DRM_ERROR("Failed to create connector for port %p: %d\n", port, ret);
2169 * Drop a topology reference, and unlink the port from the in-memory topology
2173 drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr,
2174 struct drm_dp_mst_port *port)
2176 mutex_lock(&mgr->lock);
2177 list_del(&port->next);
2178 mutex_unlock(&mgr->lock);
2179 drm_dp_mst_topology_put_port(port);
2182 static struct drm_dp_mst_port *
2183 drm_dp_mst_add_port(struct drm_device *dev,
2184 struct drm_dp_mst_topology_mgr *mgr,
2185 struct drm_dp_mst_branch *mstb, u8 port_number)
2187 struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL);
2192 kref_init(&port->topology_kref);
2193 kref_init(&port->malloc_kref);
2194 port->parent = mstb;
2195 port->port_num = port_number;
2197 port->aux.name = "DPMST";
2198 port->aux.dev = dev->dev;
2199 port->aux.is_remote = true;
2202 * Make sure the memory allocation for our parent branch stays
2203 * around until our own memory allocation is released
2205 drm_dp_mst_get_mstb_malloc(mstb);
2211 drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb,
2212 struct drm_device *dev,
2213 struct drm_dp_link_addr_reply_port *port_msg)
2215 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2216 struct drm_dp_mst_port *port;
2217 int old_ddps = 0, ret;
2218 u8 new_pdt = DP_PEER_DEVICE_NONE;
2219 bool created = false, send_link_addr = false, changed = false;
2221 port = drm_dp_get_port(mstb, port_msg->port_number);
2223 port = drm_dp_mst_add_port(dev, mgr, mstb,
2224 port_msg->port_number);
2229 } else if (!port->input && port_msg->input_port && port->connector) {
2230 /* Since port->connector can't be changed here, we create a
2231 * new port if input_port changes from 0 to 1
2233 drm_dp_mst_topology_unlink_port(mgr, port);
2234 drm_dp_mst_topology_put_port(port);
2235 port = drm_dp_mst_add_port(dev, mgr, mstb,
2236 port_msg->port_number);
2241 } else if (port->input && !port_msg->input_port) {
2243 } else if (port->connector) {
2244 /* We're updating a port that's exposed to userspace, so do it
2247 drm_modeset_lock(&mgr->base.lock, NULL);
2249 old_ddps = port->ddps;
2250 changed = port->ddps != port_msg->ddps ||
2252 (port->ldps != port_msg->legacy_device_plug_status ||
2253 port->dpcd_rev != port_msg->dpcd_revision ||
2254 port->mcs != port_msg->mcs ||
2255 port->pdt != port_msg->peer_device_type ||
2256 port->num_sdp_stream_sinks !=
2257 port_msg->num_sdp_stream_sinks));
2260 port->input = port_msg->input_port;
2262 new_pdt = port_msg->peer_device_type;
2263 port->mcs = port_msg->mcs;
2264 port->ddps = port_msg->ddps;
2265 port->ldps = port_msg->legacy_device_plug_status;
2266 port->dpcd_rev = port_msg->dpcd_revision;
2267 port->num_sdp_streams = port_msg->num_sdp_streams;
2268 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
2270 /* manage mstb port lists with mgr lock - take a reference
2273 mutex_lock(&mgr->lock);
2274 drm_dp_mst_topology_get_port(port);
2275 list_add(&port->next, &mstb->ports);
2276 mutex_unlock(&mgr->lock);
2279 if (old_ddps != port->ddps) {
2282 drm_dp_send_enum_path_resources(mgr, mstb,
2286 port->available_pbn = 0;
2290 ret = drm_dp_port_set_pdt(port, new_pdt);
2292 send_link_addr = true;
2293 } else if (ret < 0) {
2294 DRM_ERROR("Failed to change PDT on port %p: %d\n",
2300 * If this port wasn't just created, then we're reprobing because
2301 * we're coming out of suspend. In this case, always resend the link
2302 * address if there's an MSTB on this port
2304 if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING)
2305 send_link_addr = true;
2307 if (port->connector)
2308 drm_modeset_unlock(&mgr->base.lock);
2309 else if (!port->input)
2310 drm_dp_mst_port_add_connector(mstb, port);
2312 if (send_link_addr && port->mstb) {
2313 ret = drm_dp_send_link_address(mgr, port->mstb);
2314 if (ret == 1) /* MSTB below us changed */
2320 /* put reference to this port */
2321 drm_dp_mst_topology_put_port(port);
2325 drm_dp_mst_topology_unlink_port(mgr, port);
2326 if (port->connector)
2327 drm_modeset_unlock(&mgr->base.lock);
2329 drm_dp_mst_topology_put_port(port);
2334 drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb,
2335 struct drm_dp_connection_status_notify *conn_stat)
2337 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
2338 struct drm_dp_mst_port *port;
2341 bool dowork = false, create_connector = false;
2343 port = drm_dp_get_port(mstb, conn_stat->port_number);
2347 if (port->connector) {
2348 if (!port->input && conn_stat->input_port) {
2350 * We can't remove a connector from an already exposed
2351 * port, so just throw the port out and make sure we
2352 * reprobe the link address of it's parent MSTB
2354 drm_dp_mst_topology_unlink_port(mgr, port);
2355 mstb->link_address_sent = false;
2360 /* Locking is only needed if the port's exposed to userspace */
2361 drm_modeset_lock(&mgr->base.lock, NULL);
2362 } else if (port->input && !conn_stat->input_port) {
2363 create_connector = true;
2364 /* Reprobe link address so we get num_sdp_streams */
2365 mstb->link_address_sent = false;
2369 old_ddps = port->ddps;
2370 port->input = conn_stat->input_port;
2371 port->mcs = conn_stat->message_capability_status;
2372 port->ldps = conn_stat->legacy_device_plug_status;
2373 port->ddps = conn_stat->displayport_device_plug_status;
2375 if (old_ddps != port->ddps) {
2379 port->available_pbn = 0;
2383 new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type;
2385 ret = drm_dp_port_set_pdt(port, new_pdt);
2388 } else if (ret < 0) {
2389 DRM_ERROR("Failed to change PDT for port %p: %d\n",
2394 if (port->connector)
2395 drm_modeset_unlock(&mgr->base.lock);
2396 else if (create_connector)
2397 drm_dp_mst_port_add_connector(mstb, port);
2400 drm_dp_mst_topology_put_port(port);
2402 queue_work(system_long_wq, &mstb->mgr->work);
2405 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
2408 struct drm_dp_mst_branch *mstb;
2409 struct drm_dp_mst_port *port;
2411 /* find the port by iterating down */
2413 mutex_lock(&mgr->lock);
2414 mstb = mgr->mst_primary;
2419 for (i = 0; i < lct - 1; i++) {
2420 int shift = (i % 2) ? 0 : 4;
2421 int port_num = (rad[i / 2] >> shift) & 0xf;
2423 list_for_each_entry(port, &mstb->ports, next) {
2424 if (port->port_num == port_num) {
2427 DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
2435 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2439 mutex_unlock(&mgr->lock);
2443 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
2444 struct drm_dp_mst_branch *mstb,
2445 const uint8_t *guid)
2447 struct drm_dp_mst_branch *found_mstb;
2448 struct drm_dp_mst_port *port;
2450 if (memcmp(mstb->guid, guid, 16) == 0)
2454 list_for_each_entry(port, &mstb->ports, next) {
2458 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
2467 static struct drm_dp_mst_branch *
2468 drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr,
2469 const uint8_t *guid)
2471 struct drm_dp_mst_branch *mstb;
2474 /* find the port by iterating down */
2475 mutex_lock(&mgr->lock);
2477 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
2479 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2484 mutex_unlock(&mgr->lock);
2488 static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2489 struct drm_dp_mst_branch *mstb)
2491 struct drm_dp_mst_port *port;
2493 bool changed = false;
2495 if (!mstb->link_address_sent) {
2496 ret = drm_dp_send_link_address(mgr, mstb);
2503 list_for_each_entry(port, &mstb->ports, next) {
2504 struct drm_dp_mst_branch *mstb_child = NULL;
2506 if (port->input || !port->ddps)
2509 if (!port->available_pbn) {
2510 drm_modeset_lock(&mgr->base.lock, NULL);
2511 drm_dp_send_enum_path_resources(mgr, mstb, port);
2512 drm_modeset_unlock(&mgr->base.lock);
2517 mstb_child = drm_dp_mst_topology_get_mstb_validated(
2521 ret = drm_dp_check_and_send_link_address(mgr,
2523 drm_dp_mst_topology_put_mstb(mstb_child);
2534 static void drm_dp_mst_link_probe_work(struct work_struct *work)
2536 struct drm_dp_mst_topology_mgr *mgr =
2537 container_of(work, struct drm_dp_mst_topology_mgr, work);
2538 struct drm_device *dev = mgr->dev;
2539 struct drm_dp_mst_branch *mstb;
2541 bool clear_payload_id_table;
2543 mutex_lock(&mgr->probe_lock);
2545 mutex_lock(&mgr->lock);
2546 clear_payload_id_table = !mgr->payload_id_table_cleared;
2547 mgr->payload_id_table_cleared = true;
2549 mstb = mgr->mst_primary;
2551 ret = drm_dp_mst_topology_try_get_mstb(mstb);
2555 mutex_unlock(&mgr->lock);
2557 mutex_unlock(&mgr->probe_lock);
2562 * Certain branch devices seem to incorrectly report an available_pbn
2563 * of 0 on downstream sinks, even after clearing the
2564 * DP_PAYLOAD_ALLOCATE_* registers in
2565 * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C
2566 * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make
2567 * things work again.
2569 if (clear_payload_id_table) {
2570 DRM_DEBUG_KMS("Clearing payload ID table\n");
2571 drm_dp_send_clear_payload_id_table(mgr, mstb);
2574 ret = drm_dp_check_and_send_link_address(mgr, mstb);
2575 drm_dp_mst_topology_put_mstb(mstb);
2577 mutex_unlock(&mgr->probe_lock);
2579 drm_kms_helper_hotplug_event(dev);
2582 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
2587 if (memchr_inv(guid, 0, 16))
2590 salt = get_jiffies_64();
2592 memcpy(&guid[0], &salt, sizeof(u64));
2593 memcpy(&guid[8], &salt, sizeof(u64));
2598 static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
2600 struct drm_dp_sideband_msg_req_body req;
2602 req.req_type = DP_REMOTE_DPCD_READ;
2603 req.u.dpcd_read.port_number = port_num;
2604 req.u.dpcd_read.dpcd_address = offset;
2605 req.u.dpcd_read.num_bytes = num_bytes;
2606 drm_dp_encode_sideband_req(&req, msg);
2611 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
2612 bool up, u8 *msg, int len)
2615 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
2616 int tosend, total, offset;
2623 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
2625 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
2628 if (ret != tosend) {
2629 if (ret == -EIO && retries < 5) {
2633 DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
2639 } while (total > 0);
2643 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
2644 struct drm_dp_sideband_msg_tx *txmsg)
2646 struct drm_dp_mst_branch *mstb = txmsg->dst;
2649 /* both msg slots are full */
2650 if (txmsg->seqno == -1) {
2651 if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
2652 DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
2655 if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
2656 txmsg->seqno = mstb->last_seqno;
2657 mstb->last_seqno ^= 1;
2658 } else if (mstb->tx_slots[0] == NULL)
2662 mstb->tx_slots[txmsg->seqno] = txmsg;
2665 req_type = txmsg->msg[0] & 0x7f;
2666 if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
2667 req_type == DP_RESOURCE_STATUS_NOTIFY)
2671 hdr->path_msg = txmsg->path_msg;
2672 hdr->lct = mstb->lct;
2673 hdr->lcr = mstb->lct - 1;
2675 memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
2676 hdr->seqno = txmsg->seqno;
2680 * process a single block of the next message in the sideband queue
2682 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2683 struct drm_dp_sideband_msg_tx *txmsg,
2687 struct drm_dp_sideband_msg_hdr hdr;
2688 int len, space, idx, tosend;
2691 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
2693 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
2695 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
2698 /* make hdr from dst mst - for replies use seqno
2699 otherwise assign one */
2700 ret = set_hdr_from_dst_qlock(&hdr, txmsg);
2704 /* amount left to send in this message */
2705 len = txmsg->cur_len - txmsg->cur_offset;
2707 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
2708 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
2710 tosend = min(len, space);
2711 if (len == txmsg->cur_len)
2717 hdr.msg_len = tosend + 1;
2718 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
2719 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
2720 /* add crc at end */
2721 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
2724 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
2725 if (unlikely(ret) && drm_debug_enabled(DRM_UT_DP)) {
2726 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2728 drm_printf(&p, "sideband msg failed to send\n");
2729 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2733 txmsg->cur_offset += tosend;
2734 if (txmsg->cur_offset == txmsg->cur_len) {
2735 txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
2741 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
2743 struct drm_dp_sideband_msg_tx *txmsg;
2746 WARN_ON(!mutex_is_locked(&mgr->qlock));
2748 /* construct a chunk from the first msg in the tx_msg queue */
2749 if (list_empty(&mgr->tx_msg_downq))
2752 txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
2753 ret = process_single_tx_qlock(mgr, txmsg, false);
2755 /* txmsg is sent it should be in the slots now */
2756 list_del(&txmsg->next);
2758 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
2759 list_del(&txmsg->next);
2760 if (txmsg->seqno != -1)
2761 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
2762 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
2763 wake_up_all(&mgr->tx_waitq);
2767 /* called holding qlock */
2768 static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
2769 struct drm_dp_sideband_msg_tx *txmsg)
2773 /* construct a chunk from the first msg in the tx_msg queue */
2774 ret = process_single_tx_qlock(mgr, txmsg, true);
2777 DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
2779 if (txmsg->seqno != -1) {
2780 WARN_ON((unsigned int)txmsg->seqno >
2781 ARRAY_SIZE(txmsg->dst->tx_slots));
2782 txmsg->dst->tx_slots[txmsg->seqno] = NULL;
2786 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
2787 struct drm_dp_sideband_msg_tx *txmsg)
2789 mutex_lock(&mgr->qlock);
2790 list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
2792 if (drm_debug_enabled(DRM_UT_DP)) {
2793 struct drm_printer p = drm_debug_printer(DBG_PREFIX);
2795 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg);
2798 if (list_is_singular(&mgr->tx_msg_downq))
2799 process_single_down_tx_qlock(mgr);
2800 mutex_unlock(&mgr->qlock);
2804 drm_dp_dump_link_address(struct drm_dp_link_address_ack_reply *reply)
2806 struct drm_dp_link_addr_reply_port *port_reply;
2809 for (i = 0; i < reply->nports; i++) {
2810 port_reply = &reply->ports[i];
2811 DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n",
2813 port_reply->input_port,
2814 port_reply->peer_device_type,
2815 port_reply->port_number,
2816 port_reply->dpcd_revision,
2819 port_reply->legacy_device_plug_status,
2820 port_reply->num_sdp_streams,
2821 port_reply->num_sdp_stream_sinks);
2825 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
2826 struct drm_dp_mst_branch *mstb)
2828 struct drm_dp_sideband_msg_tx *txmsg;
2829 struct drm_dp_link_address_ack_reply *reply;
2830 struct drm_dp_mst_port *port, *tmp;
2831 int i, len, ret, port_mask = 0;
2832 bool changed = false;
2834 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2839 len = build_link_address(txmsg);
2841 mstb->link_address_sent = true;
2842 drm_dp_queue_down_tx(mgr, txmsg);
2844 /* FIXME: Actually do some real error handling here */
2845 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2847 DRM_ERROR("Sending link address failed with %d\n", ret);
2850 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2851 DRM_ERROR("link address NAK received\n");
2856 reply = &txmsg->reply.u.link_addr;
2857 DRM_DEBUG_KMS("link address reply: %d\n", reply->nports);
2858 drm_dp_dump_link_address(reply);
2860 drm_dp_check_mstb_guid(mstb, reply->guid);
2862 for (i = 0; i < reply->nports; i++) {
2863 port_mask |= BIT(reply->ports[i].port_number);
2864 ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev,
2872 /* Prune any ports that are currently a part of mstb in our in-memory
2873 * topology, but were not seen in this link address. Usually this
2874 * means that they were removed while the topology was out of sync,
2875 * e.g. during suspend/resume
2877 mutex_lock(&mgr->lock);
2878 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
2879 if (port_mask & BIT(port->port_num))
2882 DRM_DEBUG_KMS("port %d was not in link address, removing\n",
2884 list_del(&port->next);
2885 drm_dp_mst_topology_put_port(port);
2888 mutex_unlock(&mgr->lock);
2892 mstb->link_address_sent = false;
2894 return ret < 0 ? ret : changed;
2897 void drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr,
2898 struct drm_dp_mst_branch *mstb)
2900 struct drm_dp_sideband_msg_tx *txmsg;
2903 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2908 len = build_clear_payload_id_table(txmsg);
2910 drm_dp_queue_down_tx(mgr, txmsg);
2912 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2913 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
2914 DRM_DEBUG_KMS("clear payload table id nak received\n");
2920 drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
2921 struct drm_dp_mst_branch *mstb,
2922 struct drm_dp_mst_port *port)
2924 struct drm_dp_enum_path_resources_ack_reply *path_res;
2925 struct drm_dp_sideband_msg_tx *txmsg;
2929 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2934 len = build_enum_path_resources(txmsg, port->port_num);
2936 drm_dp_queue_down_tx(mgr, txmsg);
2938 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2940 path_res = &txmsg->reply.u.path_resources;
2942 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
2943 DRM_DEBUG_KMS("enum path resources nak received\n");
2945 if (port->port_num != path_res->port_number)
2946 DRM_ERROR("got incorrect port in response\n");
2948 DRM_DEBUG_KMS("enum path resources %d: %d %d\n",
2949 path_res->port_number,
2950 path_res->full_payload_bw_number,
2951 path_res->avail_payload_bw_number);
2952 port->available_pbn =
2953 path_res->avail_payload_bw_number;
2961 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
2963 if (!mstb->port_parent)
2966 if (mstb->port_parent->mstb != mstb)
2967 return mstb->port_parent;
2969 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
2973 * Searches upwards in the topology starting from mstb to try to find the
2974 * closest available parent of mstb that's still connected to the rest of the
2975 * topology. This can be used in order to perform operations like releasing
2976 * payloads, where the branch device which owned the payload may no longer be
2977 * around and thus would require that the payload on the last living relative
2980 static struct drm_dp_mst_branch *
2981 drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
2982 struct drm_dp_mst_branch *mstb,
2985 struct drm_dp_mst_branch *rmstb = NULL;
2986 struct drm_dp_mst_port *found_port;
2988 mutex_lock(&mgr->lock);
2989 if (!mgr->mst_primary)
2993 found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
2997 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) {
2998 rmstb = found_port->parent;
2999 *port_num = found_port->port_num;
3001 /* Search again, starting from this parent */
3002 mstb = found_port->parent;
3006 mutex_unlock(&mgr->lock);
3010 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
3011 struct drm_dp_mst_port *port,
3015 struct drm_dp_sideband_msg_tx *txmsg;
3016 struct drm_dp_mst_branch *mstb;
3017 int len, ret, port_num;
3018 u8 sinks[DRM_DP_MAX_SDP_STREAMS];
3021 port_num = port->port_num;
3022 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3024 mstb = drm_dp_get_last_connected_port_and_mstb(mgr,
3032 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3038 for (i = 0; i < port->num_sdp_streams; i++)
3042 len = build_allocate_payload(txmsg, port_num,
3044 pbn, port->num_sdp_streams, sinks);
3046 drm_dp_queue_down_tx(mgr, txmsg);
3049 * FIXME: there is a small chance that between getting the last
3050 * connected mstb and sending the payload message, the last connected
3051 * mstb could also be removed from the topology. In the future, this
3052 * needs to be fixed by restarting the
3053 * drm_dp_get_last_connected_port_and_mstb() search in the event of a
3054 * timeout if the topology is still connected to the system.
3056 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3058 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3065 drm_dp_mst_topology_put_mstb(mstb);
3069 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
3070 struct drm_dp_mst_port *port, bool power_up)
3072 struct drm_dp_sideband_msg_tx *txmsg;
3075 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3079 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3081 drm_dp_mst_topology_put_port(port);
3085 txmsg->dst = port->parent;
3086 len = build_power_updown_phy(txmsg, port->port_num, power_up);
3087 drm_dp_queue_down_tx(mgr, txmsg);
3089 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
3091 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3097 drm_dp_mst_topology_put_port(port);
3101 EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
3103 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3105 struct drm_dp_payload *payload)
3109 ret = drm_dp_dpcd_write_payload(mgr, id, payload);
3111 payload->payload_state = 0;
3114 payload->payload_state = DP_PAYLOAD_LOCAL;
3118 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3119 struct drm_dp_mst_port *port,
3121 struct drm_dp_payload *payload)
3124 ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
3127 payload->payload_state = DP_PAYLOAD_REMOTE;
3131 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
3132 struct drm_dp_mst_port *port,
3134 struct drm_dp_payload *payload)
3136 DRM_DEBUG_KMS("\n");
3137 /* it's okay for these to fail */
3139 drm_dp_payload_send_msg(mgr, port, id, 0);
3142 drm_dp_dpcd_write_payload(mgr, id, payload);
3143 payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
3147 static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
3149 struct drm_dp_payload *payload)
3151 payload->payload_state = 0;
3156 * drm_dp_update_payload_part1() - Execute payload update part 1
3157 * @mgr: manager to use.
3159 * This iterates over all proposed virtual channels, and tries to
3160 * allocate space in the link for them. For 0->slots transitions,
3161 * this step just writes the VCPI to the MST device. For slots->0
3162 * transitions, this writes the updated VCPIs and removes the
3163 * remote VC payloads.
3165 * after calling this the driver should generate ACT and payload
3168 int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
3170 struct drm_dp_payload req_payload;
3171 struct drm_dp_mst_port *port;
3175 mutex_lock(&mgr->payload_lock);
3176 for (i = 0; i < mgr->max_payloads; i++) {
3177 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
3178 struct drm_dp_payload *payload = &mgr->payloads[i];
3179 bool put_port = false;
3181 /* solve the current payloads - compare to the hw ones
3182 - update the hw view */
3183 req_payload.start_slot = cur_slots;
3185 port = container_of(vcpi, struct drm_dp_mst_port,
3188 /* Validated ports don't matter if we're releasing
3191 if (vcpi->num_slots) {
3192 port = drm_dp_mst_topology_get_port_validated(
3195 mutex_unlock(&mgr->payload_lock);
3201 req_payload.num_slots = vcpi->num_slots;
3202 req_payload.vcpi = vcpi->vcpi;
3205 req_payload.num_slots = 0;
3208 payload->start_slot = req_payload.start_slot;
3209 /* work out what is required to happen with this payload */
3210 if (payload->num_slots != req_payload.num_slots) {
3212 /* need to push an update for this payload */
3213 if (req_payload.num_slots) {
3214 drm_dp_create_payload_step1(mgr, vcpi->vcpi,
3216 payload->num_slots = req_payload.num_slots;
3217 payload->vcpi = req_payload.vcpi;
3219 } else if (payload->num_slots) {
3220 payload->num_slots = 0;
3221 drm_dp_destroy_payload_step1(mgr, port,
3224 req_payload.payload_state =
3225 payload->payload_state;
3226 payload->start_slot = 0;
3228 payload->payload_state = req_payload.payload_state;
3230 cur_slots += req_payload.num_slots;
3233 drm_dp_mst_topology_put_port(port);
3236 for (i = 0; i < mgr->max_payloads; /* do nothing */) {
3237 if (mgr->payloads[i].payload_state != DP_PAYLOAD_DELETE_LOCAL) {
3242 DRM_DEBUG_KMS("removing payload %d\n", i);
3243 for (j = i; j < mgr->max_payloads - 1; j++) {
3244 mgr->payloads[j] = mgr->payloads[j + 1];
3245 mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
3247 if (mgr->proposed_vcpis[j] &&
3248 mgr->proposed_vcpis[j]->num_slots) {
3249 set_bit(j + 1, &mgr->payload_mask);
3251 clear_bit(j + 1, &mgr->payload_mask);
3255 memset(&mgr->payloads[mgr->max_payloads - 1], 0,
3256 sizeof(struct drm_dp_payload));
3257 mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
3258 clear_bit(mgr->max_payloads, &mgr->payload_mask);
3260 mutex_unlock(&mgr->payload_lock);
3264 EXPORT_SYMBOL(drm_dp_update_payload_part1);
3267 * drm_dp_update_payload_part2() - Execute payload update part 2
3268 * @mgr: manager to use.
3270 * This iterates over all proposed virtual channels, and tries to
3271 * allocate space in the link for them. For 0->slots transitions,
3272 * this step writes the remote VC payload commands. For slots->0
3273 * this just resets some internal state.
3275 int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
3277 struct drm_dp_mst_port *port;
3280 mutex_lock(&mgr->payload_lock);
3281 for (i = 0; i < mgr->max_payloads; i++) {
3283 if (!mgr->proposed_vcpis[i])
3286 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
3288 DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
3289 if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
3290 ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3291 } else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
3292 ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
3295 mutex_unlock(&mgr->payload_lock);
3299 mutex_unlock(&mgr->payload_lock);
3302 EXPORT_SYMBOL(drm_dp_update_payload_part2);
3304 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
3305 struct drm_dp_mst_port *port,
3306 int offset, int size, u8 *bytes)
3310 struct drm_dp_sideband_msg_tx *txmsg;
3311 struct drm_dp_mst_branch *mstb;
3313 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3317 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3323 len = build_dpcd_read(txmsg, port->port_num, offset, size);
3324 txmsg->dst = port->parent;
3326 drm_dp_queue_down_tx(mgr, txmsg);
3328 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3332 /* DPCD read should never be NACKed */
3333 if (txmsg->reply.reply_type == 1) {
3334 DRM_ERROR("mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n",
3335 mstb, port->port_num, offset, size);
3340 if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) {
3345 ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes,
3347 memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret);
3352 drm_dp_mst_topology_put_mstb(mstb);
3357 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
3358 struct drm_dp_mst_port *port,
3359 int offset, int size, u8 *bytes)
3363 struct drm_dp_sideband_msg_tx *txmsg;
3364 struct drm_dp_mst_branch *mstb;
3366 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
3370 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3376 len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
3379 drm_dp_queue_down_tx(mgr, txmsg);
3381 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3383 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3390 drm_dp_mst_topology_put_mstb(mstb);
3394 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
3396 struct drm_dp_sideband_msg_reply_body reply;
3398 reply.reply_type = DP_SIDEBAND_REPLY_ACK;
3399 reply.req_type = req_type;
3400 drm_dp_encode_sideband_reply(&reply, msg);
3404 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
3405 struct drm_dp_mst_branch *mstb,
3406 int req_type, int seqno, bool broadcast)
3408 struct drm_dp_sideband_msg_tx *txmsg;
3410 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3415 txmsg->seqno = seqno;
3416 drm_dp_encode_up_ack_reply(txmsg, req_type);
3418 mutex_lock(&mgr->qlock);
3420 process_single_up_tx_qlock(mgr, txmsg);
3422 mutex_unlock(&mgr->qlock);
3428 static int drm_dp_get_vc_payload_bw(u8 dp_link_bw, u8 dp_link_count)
3430 if (dp_link_bw == 0 || dp_link_count == 0)
3431 DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
3432 dp_link_bw, dp_link_count);
3434 return dp_link_bw * dp_link_count / 2;
3438 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
3439 * @mgr: manager to set state for
3440 * @mst_state: true to enable MST on this connector - false to disable.
3442 * This is called by the driver when it detects an MST capable device plugged
3443 * into a DP MST capable port, or when a DP MST capable device is unplugged.
3445 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
3449 struct drm_dp_mst_branch *mstb = NULL;
3451 mutex_lock(&mgr->lock);
3452 if (mst_state == mgr->mst_state)
3455 mgr->mst_state = mst_state;
3456 /* set the device into MST mode */
3458 WARN_ON(mgr->mst_primary);
3461 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
3462 if (ret != DP_RECEIVER_CAP_SIZE) {
3463 DRM_DEBUG_KMS("failed to read DPCD\n");
3467 mgr->pbn_div = drm_dp_get_vc_payload_bw(mgr->dpcd[1],
3468 mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK);
3469 if (mgr->pbn_div == 0) {
3474 /* add initial branch device at LCT 1 */
3475 mstb = drm_dp_add_mst_branch_device(1, NULL);
3482 /* give this the main reference */
3483 mgr->mst_primary = mstb;
3484 drm_dp_mst_topology_get_mstb(mgr->mst_primary);
3486 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3487 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
3493 struct drm_dp_payload reset_pay;
3494 reset_pay.start_slot = 0;
3495 reset_pay.num_slots = 0x3f;
3496 drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
3499 queue_work(system_long_wq, &mgr->work);
3503 /* disable MST on the device */
3504 mstb = mgr->mst_primary;
3505 mgr->mst_primary = NULL;
3506 /* this can fail if the device is gone */
3507 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
3509 mutex_lock(&mgr->payload_lock);
3510 memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
3511 mgr->payload_mask = 0;
3512 set_bit(0, &mgr->payload_mask);
3513 for (i = 0; i < mgr->max_payloads; i++) {
3514 struct drm_dp_vcpi *vcpi = mgr->proposed_vcpis[i];
3518 vcpi->num_slots = 0;
3520 mgr->proposed_vcpis[i] = NULL;
3523 mutex_unlock(&mgr->payload_lock);
3525 mgr->payload_id_table_cleared = false;
3529 mutex_unlock(&mgr->lock);
3531 drm_dp_mst_topology_put_mstb(mstb);
3535 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
3538 drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb)
3540 struct drm_dp_mst_port *port;
3542 /* The link address will need to be re-sent on resume */
3543 mstb->link_address_sent = false;
3545 list_for_each_entry(port, &mstb->ports, next) {
3546 /* The PBN for each port will also need to be re-probed */
3547 port->available_pbn = 0;
3550 drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb);
3555 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
3556 * @mgr: manager to suspend
3558 * This function tells the MST device that we can't handle UP messages
3559 * anymore. This should stop it from sending any since we are suspended.
3561 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
3563 mutex_lock(&mgr->lock);
3564 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3565 DP_MST_EN | DP_UPSTREAM_IS_SRC);
3566 mutex_unlock(&mgr->lock);
3567 flush_work(&mgr->up_req_work);
3568 flush_work(&mgr->work);
3569 flush_work(&mgr->delayed_destroy_work);
3571 mutex_lock(&mgr->lock);
3572 if (mgr->mst_state && mgr->mst_primary)
3573 drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary);
3574 mutex_unlock(&mgr->lock);
3576 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
3579 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
3580 * @mgr: manager to resume
3581 * @sync: whether or not to perform topology reprobing synchronously
3583 * This will fetch DPCD and see if the device is still there,
3584 * if it is, it will rewrite the MSTM control bits, and return.
3586 * If the device fails this returns -1, and the driver should do
3587 * a full MST reprobe, in case we were undocked.
3589 * During system resume (where it is assumed that the driver will be calling
3590 * drm_atomic_helper_resume()) this function should be called beforehand with
3591 * @sync set to true. In contexts like runtime resume where the driver is not
3592 * expected to be calling drm_atomic_helper_resume(), this function should be
3593 * called with @sync set to false in order to avoid deadlocking.
3595 * Returns: -1 if the MST topology was removed while we were suspended, 0
3598 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr,
3604 mutex_lock(&mgr->lock);
3605 if (!mgr->mst_primary)
3608 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd,
3609 DP_RECEIVER_CAP_SIZE);
3610 if (ret != DP_RECEIVER_CAP_SIZE) {
3611 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
3615 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
3618 DP_UPSTREAM_IS_SRC);
3620 DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
3624 /* Some hubs forget their guids after they resume */
3625 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
3627 DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
3630 drm_dp_check_mstb_guid(mgr->mst_primary, guid);
3633 * For the final step of resuming the topology, we need to bring the
3634 * state of our in-memory topology back into sync with reality. So,
3635 * restart the probing process as if we're probing a new hub
3637 queue_work(system_long_wq, &mgr->work);
3638 mutex_unlock(&mgr->lock);
3641 DRM_DEBUG_KMS("Waiting for link probe work to finish re-syncing topology...\n");
3642 flush_work(&mgr->work);
3648 mutex_unlock(&mgr->lock);
3651 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
3653 static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
3657 int replylen, origlen, curreply;
3659 struct drm_dp_sideband_msg_rx *msg;
3660 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
3661 msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
3663 len = min(mgr->max_dpcd_transaction_bytes, 16);
3664 ret = drm_dp_dpcd_read(mgr->aux, basereg,
3667 DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
3670 ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
3672 DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
3675 replylen = msg->curchunk_len + msg->curchunk_hdrlen;
3680 while (replylen > 0) {
3681 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
3682 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
3685 DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
3690 ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
3692 DRM_DEBUG_KMS("failed to build sideband msg\n");
3702 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
3704 struct drm_dp_sideband_msg_tx *txmsg;
3705 struct drm_dp_mst_branch *mstb;
3706 struct drm_dp_sideband_msg_hdr *hdr = &mgr->down_rep_recv.initial_hdr;
3709 if (!drm_dp_get_one_sb_msg(mgr, false))
3710 goto clear_down_rep_recv;
3712 if (!mgr->down_rep_recv.have_eomt)
3715 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
3717 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
3719 goto clear_down_rep_recv;
3722 /* find the message */
3724 mutex_lock(&mgr->qlock);
3725 txmsg = mstb->tx_slots[slot];
3726 /* remove from slots */
3727 mutex_unlock(&mgr->qlock);
3730 DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
3731 mstb, hdr->seqno, hdr->lct, hdr->rad[0],
3732 mgr->down_rep_recv.msg[0]);
3736 drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
3738 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK)
3739 DRM_DEBUG_KMS("Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n",
3740 txmsg->reply.req_type,
3741 drm_dp_mst_req_type_str(txmsg->reply.req_type),
3742 txmsg->reply.u.nak.reason,
3743 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason),
3744 txmsg->reply.u.nak.nak_data);
3746 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
3747 drm_dp_mst_topology_put_mstb(mstb);
3749 mutex_lock(&mgr->qlock);
3750 txmsg->state = DRM_DP_SIDEBAND_TX_RX;
3751 mstb->tx_slots[slot] = NULL;
3752 mutex_unlock(&mgr->qlock);
3754 wake_up_all(&mgr->tx_waitq);
3759 drm_dp_mst_topology_put_mstb(mstb);
3760 clear_down_rep_recv:
3761 memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
3767 drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr,
3768 struct drm_dp_pending_up_req *up_req)
3770 struct drm_dp_mst_branch *mstb = NULL;
3771 struct drm_dp_sideband_msg_req_body *msg = &up_req->msg;
3772 struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr;
3773 bool hotplug = false;
3775 if (hdr->broadcast) {
3776 const u8 *guid = NULL;
3778 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY)
3779 guid = msg->u.conn_stat.guid;
3780 else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY)
3781 guid = msg->u.resource_stat.guid;
3783 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid);
3785 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad);
3789 DRM_DEBUG_KMS("Got MST reply from unknown device %d\n",
3794 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */
3795 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) {
3796 drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat);
3800 drm_dp_mst_topology_put_mstb(mstb);
3804 static void drm_dp_mst_up_req_work(struct work_struct *work)
3806 struct drm_dp_mst_topology_mgr *mgr =
3807 container_of(work, struct drm_dp_mst_topology_mgr,
3809 struct drm_dp_pending_up_req *up_req;
3810 bool send_hotplug = false;
3812 mutex_lock(&mgr->probe_lock);
3814 mutex_lock(&mgr->up_req_lock);
3815 up_req = list_first_entry_or_null(&mgr->up_req_list,
3816 struct drm_dp_pending_up_req,
3819 list_del(&up_req->next);
3820 mutex_unlock(&mgr->up_req_lock);
3825 send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req);
3828 mutex_unlock(&mgr->probe_lock);
3831 drm_kms_helper_hotplug_event(mgr->dev);
3834 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
3836 struct drm_dp_sideband_msg_hdr *hdr = &mgr->up_req_recv.initial_hdr;
3837 struct drm_dp_pending_up_req *up_req;
3840 if (!drm_dp_get_one_sb_msg(mgr, true))
3843 if (!mgr->up_req_recv.have_eomt)
3846 up_req = kzalloc(sizeof(*up_req), GFP_KERNEL);
3848 DRM_ERROR("Not enough memory to process MST up req\n");
3851 INIT_LIST_HEAD(&up_req->next);
3854 drm_dp_sideband_parse_req(&mgr->up_req_recv, &up_req->msg);
3856 if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY &&
3857 up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) {
3858 DRM_DEBUG_KMS("Received unknown up req type, ignoring: %x\n",
3859 up_req->msg.req_type);
3864 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type,
3867 if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
3868 const struct drm_dp_connection_status_notify *conn_stat =
3869 &up_req->msg.u.conn_stat;
3871 DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n",
3872 conn_stat->port_number,
3873 conn_stat->legacy_device_plug_status,
3874 conn_stat->displayport_device_plug_status,
3875 conn_stat->message_capability_status,
3876 conn_stat->input_port,
3877 conn_stat->peer_device_type);
3878 } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
3879 const struct drm_dp_resource_status_notify *res_stat =
3880 &up_req->msg.u.resource_stat;
3882 DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n",
3883 res_stat->port_number,
3884 res_stat->available_pbn);
3888 mutex_lock(&mgr->up_req_lock);
3889 list_add_tail(&up_req->next, &mgr->up_req_list);
3890 mutex_unlock(&mgr->up_req_lock);
3891 queue_work(system_long_wq, &mgr->up_req_work);
3894 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
3899 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
3900 * @mgr: manager to notify irq for.
3901 * @esi: 4 bytes from SINK_COUNT_ESI
3902 * @handled: whether the hpd interrupt was consumed or not
3904 * This should be called from the driver when it detects a short IRQ,
3905 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
3906 * topology manager will process the sideband messages received as a result
3909 int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
3916 if (sc != mgr->sink_count) {
3917 mgr->sink_count = sc;
3921 if (esi[1] & DP_DOWN_REP_MSG_RDY) {
3922 ret = drm_dp_mst_handle_down_rep(mgr);
3926 if (esi[1] & DP_UP_REQ_MSG_RDY) {
3927 ret |= drm_dp_mst_handle_up_req(mgr);
3931 drm_dp_mst_kick_tx(mgr);
3934 EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
3937 * drm_dp_mst_detect_port() - get connection status for an MST port
3938 * @connector: DRM connector for this port
3939 * @ctx: The acquisition context to use for grabbing locks
3940 * @mgr: manager for this port
3941 * @port: pointer to a port
3943 * This returns the current connection state for a port.
3946 drm_dp_mst_detect_port(struct drm_connector *connector,
3947 struct drm_modeset_acquire_ctx *ctx,
3948 struct drm_dp_mst_topology_mgr *mgr,
3949 struct drm_dp_mst_port *port)
3953 /* we need to search for the port in the mgr in case it's gone */
3954 port = drm_dp_mst_topology_get_port_validated(mgr, port);
3956 return connector_status_disconnected;
3958 ret = drm_modeset_lock(&mgr->base.lock, ctx);
3962 ret = connector_status_disconnected;
3967 switch (port->pdt) {
3968 case DP_PEER_DEVICE_NONE:
3969 case DP_PEER_DEVICE_MST_BRANCHING:
3972 case DP_PEER_DEVICE_SST_SINK:
3973 ret = connector_status_connected;
3974 /* for logical ports - cache the EDID */
3975 if (port->port_num >= 8 && !port->cached_edid) {
3976 port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
3979 case DP_PEER_DEVICE_DP_LEGACY_CONV:
3981 ret = connector_status_connected;
3985 drm_dp_mst_topology_put_port(port);
3988 EXPORT_SYMBOL(drm_dp_mst_detect_port);
3991 * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
3992 * @mgr: manager for this port
3993 * @port: unverified pointer to a port.
3995 * This returns whether the port supports audio or not.
3997 bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
3998 struct drm_dp_mst_port *port)
4002 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4005 ret = port->has_audio;
4006 drm_dp_mst_topology_put_port(port);
4009 EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
4012 * drm_dp_mst_get_edid() - get EDID for an MST port
4013 * @connector: toplevel connector to get EDID for
4014 * @mgr: manager for this port
4015 * @port: unverified pointer to a port.
4017 * This returns an EDID for the port connected to a connector,
4018 * It validates the pointer still exists so the caller doesn't require a
4021 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4023 struct edid *edid = NULL;
4025 /* we need to search for the port in the mgr in case it's gone */
4026 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4030 if (port->cached_edid)
4031 edid = drm_edid_duplicate(port->cached_edid);
4033 edid = drm_get_edid(connector, &port->aux.ddc);
4035 port->has_audio = drm_detect_monitor_audio(edid);
4036 drm_dp_mst_topology_put_port(port);
4039 EXPORT_SYMBOL(drm_dp_mst_get_edid);
4042 * drm_dp_find_vcpi_slots() - Find VCPI slots for this PBN value
4043 * @mgr: manager to use
4044 * @pbn: payload bandwidth to convert into slots.
4046 * Calculate the number of VCPI slots that will be required for the given PBN
4047 * value. This function is deprecated, and should not be used in atomic
4051 * The total slots required for this port, or error.
4053 int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
4058 num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
4060 /* max. time slots - one slot for MTP header */
4065 EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
4067 static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4068 struct drm_dp_vcpi *vcpi, int pbn, int slots)
4072 /* max. time slots - one slot for MTP header */
4077 vcpi->aligned_pbn = slots * mgr->pbn_div;
4078 vcpi->num_slots = slots;
4080 ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
4087 * drm_dp_atomic_find_vcpi_slots() - Find and add VCPI slots to the state
4088 * @state: global atomic state
4089 * @mgr: MST topology manager for the port
4090 * @port: port to find vcpi slots for
4091 * @pbn: bandwidth required for the mode in PBN
4093 * Allocates VCPI slots to @port, replacing any previous VCPI allocations it
4094 * may have had. Any atomic drivers which support MST must call this function
4095 * in their &drm_encoder_helper_funcs.atomic_check() callback to change the
4096 * current VCPI allocation for the new state, but only when
4097 * &drm_crtc_state.mode_changed or &drm_crtc_state.connectors_changed is set
4098 * to ensure compatibility with userspace applications that still use the
4099 * legacy modesetting UAPI.
4101 * Allocations set by this function are not checked against the bandwidth
4102 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check().
4104 * Additionally, it is OK to call this function multiple times on the same
4105 * @port as needed. It is not OK however, to call this function and
4106 * drm_dp_atomic_release_vcpi_slots() in the same atomic check phase.
4109 * drm_dp_atomic_release_vcpi_slots()
4110 * drm_dp_mst_atomic_check()
4113 * Total slots in the atomic state assigned for this port, or a negative error
4114 * code if the port no longer exists
4116 int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
4117 struct drm_dp_mst_topology_mgr *mgr,
4118 struct drm_dp_mst_port *port, int pbn)
4120 struct drm_dp_mst_topology_state *topology_state;
4121 struct drm_dp_vcpi_allocation *pos, *vcpi = NULL;
4122 int prev_slots, req_slots;
4124 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4125 if (IS_ERR(topology_state))
4126 return PTR_ERR(topology_state);
4128 /* Find the current allocation for this port, if any */
4129 list_for_each_entry(pos, &topology_state->vcpis, next) {
4130 if (pos->port == port) {
4132 prev_slots = vcpi->vcpi;
4135 * This should never happen, unless the driver tries
4136 * releasing and allocating the same VCPI allocation,
4139 if (WARN_ON(!prev_slots)) {
4140 DRM_ERROR("cannot allocate and release VCPI on [MST PORT:%p] in the same state\n",
4151 req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
4153 DRM_DEBUG_ATOMIC("[CONNECTOR:%d:%s] [MST PORT:%p] VCPI %d -> %d\n",
4154 port->connector->base.id, port->connector->name,
4155 port, prev_slots, req_slots);
4157 /* Add the new allocation to the state */
4159 vcpi = kzalloc(sizeof(*vcpi), GFP_KERNEL);
4163 drm_dp_mst_get_port_malloc(port);
4165 list_add(&vcpi->next, &topology_state->vcpis);
4167 vcpi->vcpi = req_slots;
4171 EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
4174 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
4175 * @state: global atomic state
4176 * @mgr: MST topology manager for the port
4177 * @port: The port to release the VCPI slots from
4179 * Releases any VCPI slots that have been allocated to a port in the atomic
4180 * state. Any atomic drivers which support MST must call this function in
4181 * their &drm_connector_helper_funcs.atomic_check() callback when the
4182 * connector will no longer have VCPI allocated (e.g. because its CRTC was
4183 * removed) when it had VCPI allocated in the previous atomic state.
4185 * It is OK to call this even if @port has been removed from the system.
4186 * Additionally, it is OK to call this function multiple times on the same
4187 * @port as needed. It is not OK however, to call this function and
4188 * drm_dp_atomic_find_vcpi_slots() on the same @port in a single atomic check
4192 * drm_dp_atomic_find_vcpi_slots()
4193 * drm_dp_mst_atomic_check()
4196 * 0 if all slots for this port were added back to
4197 * &drm_dp_mst_topology_state.avail_slots or negative error code
4199 int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
4200 struct drm_dp_mst_topology_mgr *mgr,
4201 struct drm_dp_mst_port *port)
4203 struct drm_dp_mst_topology_state *topology_state;
4204 struct drm_dp_vcpi_allocation *pos;
4207 topology_state = drm_atomic_get_mst_topology_state(state, mgr);
4208 if (IS_ERR(topology_state))
4209 return PTR_ERR(topology_state);
4211 list_for_each_entry(pos, &topology_state->vcpis, next) {
4212 if (pos->port == port) {
4217 if (WARN_ON(!found)) {
4218 DRM_ERROR("no VCPI for [MST PORT:%p] found in mst state %p\n",
4219 port, &topology_state->base);
4223 DRM_DEBUG_ATOMIC("[MST PORT:%p] VCPI %d -> 0\n", port, pos->vcpi);
4225 drm_dp_mst_put_port_malloc(port);
4231 EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
4234 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
4235 * @mgr: manager for this port
4236 * @port: port to allocate a virtual channel for.
4237 * @pbn: payload bandwidth number to request
4238 * @slots: returned number of slots for this PBN.
4240 bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4241 struct drm_dp_mst_port *port, int pbn, int slots)
4245 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4252 if (port->vcpi.vcpi > 0) {
4253 DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n",
4254 port->vcpi.vcpi, port->vcpi.pbn, pbn);
4255 if (pbn == port->vcpi.pbn) {
4256 drm_dp_mst_topology_put_port(port);
4261 ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
4263 DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
4264 DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
4267 DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
4268 pbn, port->vcpi.num_slots);
4270 /* Keep port allocated until its payload has been removed */
4271 drm_dp_mst_get_port_malloc(port);
4272 drm_dp_mst_topology_put_port(port);
4277 EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
4279 int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4282 port = drm_dp_mst_topology_get_port_validated(mgr, port);
4286 slots = port->vcpi.num_slots;
4287 drm_dp_mst_topology_put_port(port);
4290 EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
4293 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
4294 * @mgr: manager for this port
4295 * @port: unverified pointer to a port.
4297 * This just resets the number of slots for the ports VCPI for later programming.
4299 void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
4302 * A port with VCPI will remain allocated until its VCPI is
4303 * released, no verified ref needed
4306 port->vcpi.num_slots = 0;
4308 EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
4311 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
4312 * @mgr: manager for this port
4313 * @port: port to deallocate vcpi for
4315 * This can be called unconditionally, regardless of whether
4316 * drm_dp_mst_allocate_vcpi() succeeded or not.
4318 void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
4319 struct drm_dp_mst_port *port)
4321 if (!port->vcpi.vcpi)
4324 drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
4325 port->vcpi.num_slots = 0;
4327 port->vcpi.aligned_pbn = 0;
4328 port->vcpi.vcpi = 0;
4329 drm_dp_mst_put_port_malloc(port);
4331 EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
4333 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
4334 int id, struct drm_dp_payload *payload)
4336 u8 payload_alloc[3], status;
4340 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
4341 DP_PAYLOAD_TABLE_UPDATED);
4343 payload_alloc[0] = id;
4344 payload_alloc[1] = payload->start_slot;
4345 payload_alloc[2] = payload->num_slots;
4347 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
4349 DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
4354 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4356 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
4360 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
4363 usleep_range(10000, 20000);
4366 DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
4377 * drm_dp_check_act_status() - Check ACT handled status.
4378 * @mgr: manager to use
4380 * Check the payload status bits in the DPCD for ACT handled completion.
4382 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
4389 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
4392 DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
4396 if (status & DP_PAYLOAD_ACT_HANDLED)
4401 } while (count < 30);
4403 if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
4404 DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
4412 EXPORT_SYMBOL(drm_dp_check_act_status);
4415 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
4416 * @clock: dot clock for the mode
4417 * @bpp: bpp for the mode.
4419 * This uses the formula in the spec to calculate the PBN value for a mode.
4421 int drm_dp_calc_pbn_mode(int clock, int bpp)
4424 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
4425 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
4426 * common multiplier to render an integer PBN for all link rate/lane
4427 * counts combinations
4429 * peak_kbps *= (1006/1000)
4430 * peak_kbps *= (64/54)
4431 * peak_kbps *= 8 convert to bytes
4433 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006),
4434 8 * 54 * 1000 * 1000);
4436 EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
4438 /* we want to kick the TX after we've ack the up/down IRQs. */
4439 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
4441 queue_work(system_long_wq, &mgr->tx_work);
4444 static void drm_dp_mst_dump_mstb(struct seq_file *m,
4445 struct drm_dp_mst_branch *mstb)
4447 struct drm_dp_mst_port *port;
4448 int tabs = mstb->lct;
4452 for (i = 0; i < tabs; i++)
4456 seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
4457 list_for_each_entry(port, &mstb->ports, next) {
4458 seq_printf(m, "%sport: %d: input: %d: pdt: %d, ddps: %d ldps: %d, sdp: %d/%d, %p, conn: %p\n", prefix, port->port_num, port->input, port->pdt, port->ddps, port->ldps, port->num_sdp_streams, port->num_sdp_stream_sinks, port, port->connector);
4460 drm_dp_mst_dump_mstb(m, port->mstb);
4464 #define DP_PAYLOAD_TABLE_SIZE 64
4466 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
4471 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) {
4472 if (drm_dp_dpcd_read(mgr->aux,
4473 DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
4480 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
4481 struct drm_dp_mst_port *port, char *name,
4484 struct edid *mst_edid;
4486 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
4487 drm_edid_get_monitor_name(mst_edid, name, namelen);
4491 * drm_dp_mst_dump_topology(): dump topology to seq file.
4492 * @m: seq_file to dump output to
4493 * @mgr: manager to dump current topology for.
4495 * helper to dump MST topology to a seq file for debugfs.
4497 void drm_dp_mst_dump_topology(struct seq_file *m,
4498 struct drm_dp_mst_topology_mgr *mgr)
4501 struct drm_dp_mst_port *port;
4503 mutex_lock(&mgr->lock);
4504 if (mgr->mst_primary)
4505 drm_dp_mst_dump_mstb(m, mgr->mst_primary);
4508 mutex_unlock(&mgr->lock);
4510 mutex_lock(&mgr->payload_lock);
4511 seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
4514 for (i = 0; i < mgr->max_payloads; i++) {
4515 if (mgr->proposed_vcpis[i]) {
4518 port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
4519 fetch_monitor_name(mgr, port, name, sizeof(name));
4520 seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
4521 port->port_num, port->vcpi.vcpi,
4522 port->vcpi.num_slots,
4523 (*name != 0) ? name : "Unknown");
4525 seq_printf(m, "vcpi %d:unused\n", i);
4527 for (i = 0; i < mgr->max_payloads; i++) {
4528 seq_printf(m, "payload %d: %d, %d, %d\n",
4530 mgr->payloads[i].payload_state,
4531 mgr->payloads[i].start_slot,
4532 mgr->payloads[i].num_slots);
4536 mutex_unlock(&mgr->payload_lock);
4538 mutex_lock(&mgr->lock);
4539 if (mgr->mst_primary) {
4540 u8 buf[DP_PAYLOAD_TABLE_SIZE];
4543 ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
4544 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
4545 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
4546 seq_printf(m, "faux/mst: %*ph\n", 2, buf);
4547 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
4548 seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
4550 /* dump the standard OUI branch header */
4551 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
4552 seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
4553 for (i = 0x3; i < 0x8 && buf[i]; i++)
4554 seq_printf(m, "%c", buf[i]);
4555 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
4556 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
4557 if (dump_dp_payload_table(mgr, buf))
4558 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf);
4561 mutex_unlock(&mgr->lock);
4564 EXPORT_SYMBOL(drm_dp_mst_dump_topology);
4566 static void drm_dp_tx_work(struct work_struct *work)
4568 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
4570 mutex_lock(&mgr->qlock);
4571 if (!list_empty(&mgr->tx_msg_downq))
4572 process_single_down_tx_qlock(mgr);
4573 mutex_unlock(&mgr->qlock);
4577 drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port)
4579 if (port->connector)
4580 port->mgr->cbs->destroy_connector(port->mgr, port->connector);
4582 drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE);
4583 drm_dp_mst_put_port_malloc(port);
4587 drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb)
4589 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
4590 struct drm_dp_mst_port *port, *tmp;
4591 bool wake_tx = false;
4593 mutex_lock(&mgr->lock);
4594 list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
4595 list_del(&port->next);
4596 drm_dp_mst_topology_put_port(port);
4598 mutex_unlock(&mgr->lock);
4600 /* drop any tx slots msg */
4601 mutex_lock(&mstb->mgr->qlock);
4602 if (mstb->tx_slots[0]) {
4603 mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
4604 mstb->tx_slots[0] = NULL;
4607 if (mstb->tx_slots[1]) {
4608 mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
4609 mstb->tx_slots[1] = NULL;
4612 mutex_unlock(&mstb->mgr->qlock);
4615 wake_up_all(&mstb->mgr->tx_waitq);
4617 drm_dp_mst_put_mstb_malloc(mstb);
4620 static void drm_dp_delayed_destroy_work(struct work_struct *work)
4622 struct drm_dp_mst_topology_mgr *mgr =
4623 container_of(work, struct drm_dp_mst_topology_mgr,
4624 delayed_destroy_work);
4625 bool send_hotplug = false, go_again;
4628 * Not a regular list traverse as we have to drop the destroy
4629 * connector lock before destroying the mstb/port, to avoid AB->BA
4630 * ordering between this lock and the config mutex.
4636 struct drm_dp_mst_branch *mstb;
4638 mutex_lock(&mgr->delayed_destroy_lock);
4639 mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list,
4640 struct drm_dp_mst_branch,
4643 list_del(&mstb->destroy_next);
4644 mutex_unlock(&mgr->delayed_destroy_lock);
4649 drm_dp_delayed_destroy_mstb(mstb);
4654 struct drm_dp_mst_port *port;
4656 mutex_lock(&mgr->delayed_destroy_lock);
4657 port = list_first_entry_or_null(&mgr->destroy_port_list,
4658 struct drm_dp_mst_port,
4661 list_del(&port->next);
4662 mutex_unlock(&mgr->delayed_destroy_lock);
4667 drm_dp_delayed_destroy_port(port);
4668 send_hotplug = true;
4674 drm_kms_helper_hotplug_event(mgr->dev);
4677 static struct drm_private_state *
4678 drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
4680 struct drm_dp_mst_topology_state *state, *old_state =
4681 to_dp_mst_topology_state(obj->state);
4682 struct drm_dp_vcpi_allocation *pos, *vcpi;
4684 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL);
4688 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
4690 INIT_LIST_HEAD(&state->vcpis);
4692 list_for_each_entry(pos, &old_state->vcpis, next) {
4693 /* Prune leftover freed VCPI allocations */
4697 vcpi = kmemdup(pos, sizeof(*vcpi), GFP_KERNEL);
4701 drm_dp_mst_get_port_malloc(vcpi->port);
4702 list_add(&vcpi->next, &state->vcpis);
4705 return &state->base;
4708 list_for_each_entry_safe(pos, vcpi, &state->vcpis, next) {
4709 drm_dp_mst_put_port_malloc(pos->port);
4717 static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
4718 struct drm_private_state *state)
4720 struct drm_dp_mst_topology_state *mst_state =
4721 to_dp_mst_topology_state(state);
4722 struct drm_dp_vcpi_allocation *pos, *tmp;
4724 list_for_each_entry_safe(pos, tmp, &mst_state->vcpis, next) {
4725 /* We only keep references to ports with non-zero VCPIs */
4727 drm_dp_mst_put_port_malloc(pos->port);
4735 drm_dp_mst_atomic_check_topology_state(struct drm_dp_mst_topology_mgr *mgr,
4736 struct drm_dp_mst_topology_state *mst_state)
4738 struct drm_dp_vcpi_allocation *vcpi;
4739 int avail_slots = 63, payload_count = 0;
4741 list_for_each_entry(vcpi, &mst_state->vcpis, next) {
4742 /* Releasing VCPI is always OK-even if the port is gone */
4744 DRM_DEBUG_ATOMIC("[MST PORT:%p] releases all VCPI slots\n",
4749 DRM_DEBUG_ATOMIC("[MST PORT:%p] requires %d vcpi slots\n",
4750 vcpi->port, vcpi->vcpi);
4752 avail_slots -= vcpi->vcpi;
4753 if (avail_slots < 0) {
4754 DRM_DEBUG_ATOMIC("[MST PORT:%p] not enough VCPI slots in mst state %p (avail=%d)\n",
4755 vcpi->port, mst_state,
4756 avail_slots + vcpi->vcpi);
4760 if (++payload_count > mgr->max_payloads) {
4761 DRM_DEBUG_ATOMIC("[MST MGR:%p] state %p has too many payloads (max=%d)\n",
4762 mgr, mst_state, mgr->max_payloads);
4766 DRM_DEBUG_ATOMIC("[MST MGR:%p] mst state %p VCPI avail=%d used=%d\n",
4767 mgr, mst_state, avail_slots,
4774 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an
4775 * atomic update is valid
4776 * @state: Pointer to the new &struct drm_dp_mst_topology_state
4778 * Checks the given topology state for an atomic update to ensure that it's
4779 * valid. This includes checking whether there's enough bandwidth to support
4780 * the new VCPI allocations in the atomic update.
4782 * Any atomic drivers supporting DP MST must make sure to call this after
4783 * checking the rest of their state in their
4784 * &drm_mode_config_funcs.atomic_check() callback.
4787 * drm_dp_atomic_find_vcpi_slots()
4788 * drm_dp_atomic_release_vcpi_slots()
4792 * 0 if the new state is valid, negative error code otherwise.
4794 int drm_dp_mst_atomic_check(struct drm_atomic_state *state)
4796 struct drm_dp_mst_topology_mgr *mgr;
4797 struct drm_dp_mst_topology_state *mst_state;
4800 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) {
4801 ret = drm_dp_mst_atomic_check_topology_state(mgr, mst_state);
4808 EXPORT_SYMBOL(drm_dp_mst_atomic_check);
4810 const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = {
4811 .atomic_duplicate_state = drm_dp_mst_duplicate_state,
4812 .atomic_destroy_state = drm_dp_mst_destroy_state,
4814 EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs);
4817 * drm_atomic_get_mst_topology_state: get MST topology state
4819 * @state: global atomic state
4820 * @mgr: MST topology manager, also the private object in this case
4822 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
4823 * state vtable so that the private object state returned is that of a MST
4824 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
4825 * to care of the locking, so warn if don't hold the connection_mutex.
4829 * The MST topology state or error pointer.
4831 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
4832 struct drm_dp_mst_topology_mgr *mgr)
4834 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
4836 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
4839 * drm_dp_mst_topology_mgr_init - initialise a topology manager
4840 * @mgr: manager struct to initialise
4841 * @dev: device providing this structure - for i2c addition.
4842 * @aux: DP helper aux channel to talk to this device
4843 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
4844 * @max_payloads: maximum number of payloads this GPU can source
4845 * @conn_base_id: the connector object ID the MST device is connected to.
4847 * Return 0 for success, or negative error code on failure
4849 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
4850 struct drm_device *dev, struct drm_dp_aux *aux,
4851 int max_dpcd_transaction_bytes,
4852 int max_payloads, int conn_base_id)
4854 struct drm_dp_mst_topology_state *mst_state;
4856 mutex_init(&mgr->lock);
4857 mutex_init(&mgr->qlock);
4858 mutex_init(&mgr->payload_lock);
4859 mutex_init(&mgr->delayed_destroy_lock);
4860 mutex_init(&mgr->up_req_lock);
4861 mutex_init(&mgr->probe_lock);
4862 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
4863 mutex_init(&mgr->topology_ref_history_lock);
4865 INIT_LIST_HEAD(&mgr->tx_msg_downq);
4866 INIT_LIST_HEAD(&mgr->destroy_port_list);
4867 INIT_LIST_HEAD(&mgr->destroy_branch_device_list);
4868 INIT_LIST_HEAD(&mgr->up_req_list);
4869 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
4870 INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
4871 INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work);
4872 INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work);
4873 init_waitqueue_head(&mgr->tx_waitq);
4876 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
4877 mgr->max_payloads = max_payloads;
4878 mgr->conn_base_id = conn_base_id;
4879 if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
4880 max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
4882 mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
4885 mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
4886 if (!mgr->proposed_vcpis)
4888 set_bit(0, &mgr->payload_mask);
4890 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
4891 if (mst_state == NULL)
4894 mst_state->mgr = mgr;
4895 INIT_LIST_HEAD(&mst_state->vcpis);
4897 drm_atomic_private_obj_init(dev, &mgr->base,
4899 &drm_dp_mst_topology_state_funcs);
4903 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
4906 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
4907 * @mgr: manager to destroy
4909 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
4911 drm_dp_mst_topology_mgr_set_mst(mgr, false);
4912 flush_work(&mgr->work);
4913 cancel_work_sync(&mgr->delayed_destroy_work);
4914 mutex_lock(&mgr->payload_lock);
4915 kfree(mgr->payloads);
4916 mgr->payloads = NULL;
4917 kfree(mgr->proposed_vcpis);
4918 mgr->proposed_vcpis = NULL;
4919 mutex_unlock(&mgr->payload_lock);
4922 drm_atomic_private_obj_fini(&mgr->base);
4925 mutex_destroy(&mgr->delayed_destroy_lock);
4926 mutex_destroy(&mgr->payload_lock);
4927 mutex_destroy(&mgr->qlock);
4928 mutex_destroy(&mgr->lock);
4929 mutex_destroy(&mgr->up_req_lock);
4930 mutex_destroy(&mgr->probe_lock);
4931 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS)
4932 mutex_destroy(&mgr->topology_ref_history_lock);
4935 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
4937 static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num)
4941 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)
4944 for (i = 0; i < num - 1; i++) {
4945 if (msgs[i].flags & I2C_M_RD ||
4950 return msgs[num - 1].flags & I2C_M_RD &&
4951 msgs[num - 1].len <= 0xff;
4955 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
4958 struct drm_dp_aux *aux = adapter->algo_data;
4959 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
4960 struct drm_dp_mst_branch *mstb;
4961 struct drm_dp_mst_topology_mgr *mgr = port->mgr;
4963 struct drm_dp_sideband_msg_req_body msg;
4964 struct drm_dp_sideband_msg_tx *txmsg = NULL;
4967 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent);
4971 if (!remote_i2c_read_ok(msgs, num)) {
4972 DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
4977 memset(&msg, 0, sizeof(msg));
4978 msg.req_type = DP_REMOTE_I2C_READ;
4979 msg.u.i2c_read.num_transactions = num - 1;
4980 msg.u.i2c_read.port_number = port->port_num;
4981 for (i = 0; i < num - 1; i++) {
4982 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
4983 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
4984 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
4985 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP);
4987 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
4988 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
4990 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
4997 drm_dp_encode_sideband_req(&msg, txmsg);
4999 drm_dp_queue_down_tx(mgr, txmsg);
5001 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
5004 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) {
5008 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
5012 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
5017 drm_dp_mst_topology_put_mstb(mstb);
5021 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
5023 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
5024 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
5025 I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
5026 I2C_FUNC_10BIT_ADDR;
5029 static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
5030 .functionality = drm_dp_mst_i2c_functionality,
5031 .master_xfer = drm_dp_mst_i2c_xfer,
5035 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
5036 * @aux: DisplayPort AUX channel
5038 * Returns 0 on success or a negative error code on failure.
5040 static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
5042 aux->ddc.algo = &drm_dp_mst_i2c_algo;
5043 aux->ddc.algo_data = aux;
5044 aux->ddc.retries = 3;
5046 aux->ddc.class = I2C_CLASS_DDC;
5047 aux->ddc.owner = THIS_MODULE;
5048 aux->ddc.dev.parent = aux->dev;
5049 aux->ddc.dev.of_node = aux->dev->of_node;
5051 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
5052 sizeof(aux->ddc.name));
5054 return i2c_add_adapter(&aux->ddc);
5058 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
5059 * @aux: DisplayPort AUX channel
5061 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
5063 i2c_del_adapter(&aux->ddc);