1/*
   2 * Copyright © 2014 Red Hat
   3 *
   4 * Permission to use, copy, modify, distribute, and sell this software and its
   5 * documentation for any purpose is hereby granted without fee, provided that
   6 * the above copyright notice appear in all copies and that both that copyright
   7 * notice and this permission notice appear in supporting documentation, and
   8 * that the name of the copyright holders not be used in advertising or
   9 * publicity pertaining to distribution of the software without specific,
  10 * written prior permission.  The copyright holders make no representations
  11 * about the suitability of this software for any purpose.  It is provided "as
  12 * is" without express or implied warranty.
  13 *
  14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
  15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
  16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
  17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
  18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
  19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  20 * OF THIS SOFTWARE.
  21 */
  22
  23#include <linux/kernel.h>
  24#include <linux/delay.h>
  25#include <linux/init.h>
  26#include <linux/errno.h>
  27#include <linux/sched.h>
  28#include <linux/seq_file.h>
  29#include <linux/i2c.h>
  30#include <drm/drm_dp_mst_helper.h>
  31#include <drm/drmP.h>
  32
  33#include <drm/drm_fixed.h>
  34#include <drm/drm_atomic.h>
  35#include <drm/drm_atomic_helper.h>
  36
  37/**
  38 * DOC: dp mst helper
  39 *
  40 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport
  41 * protocol. The helpers contain a topology manager and bandwidth manager.
  42 * The helpers encapsulate the sending and received of sideband msgs.
  43 */
  44static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
  45				  char *buf);
  46static int test_calc_pbn_mode(void);
  47
  48static void drm_dp_put_port(struct drm_dp_mst_port *port);
  49
  50static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
  51				     int id,
  52				     struct drm_dp_payload *payload);
  53
  54static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
  55				  struct drm_dp_mst_port *port,
  56				  int offset, int size, u8 *bytes);
  57
  58static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
  59				     struct drm_dp_mst_branch *mstb);
  60static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
  61					   struct drm_dp_mst_branch *mstb,
  62					   struct drm_dp_mst_port *port);
  63static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
  64				 u8 *guid);
  65
  66static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux);
  67static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux);
  68static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr);
  69/* sideband msg handling */
  70static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles)
  71{
  72	u8 bitmask = 0x80;
  73	u8 bitshift = 7;
  74	u8 array_index = 0;
  75	int number_of_bits = num_nibbles * 4;
  76	u8 remainder = 0;
  77
  78	while (number_of_bits != 0) {
  79		number_of_bits--;
  80		remainder <<= 1;
  81		remainder |= (data[array_index] & bitmask) >> bitshift;
  82		bitmask >>= 1;
  83		bitshift--;
  84		if (bitmask == 0) {
  85			bitmask = 0x80;
  86			bitshift = 7;
  87			array_index++;
  88		}
  89		if ((remainder & 0x10) == 0x10)
  90			remainder ^= 0x13;
  91	}
  92
  93	number_of_bits = 4;
  94	while (number_of_bits != 0) {
  95		number_of_bits--;
  96		remainder <<= 1;
  97		if ((remainder & 0x10) != 0)
  98			remainder ^= 0x13;
  99	}
 100
 101	return remainder;
 102}
 103
 104static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes)
 105{
 106	u8 bitmask = 0x80;
 107	u8 bitshift = 7;
 108	u8 array_index = 0;
 109	int number_of_bits = number_of_bytes * 8;
 110	u16 remainder = 0;
 111
 112	while (number_of_bits != 0) {
 113		number_of_bits--;
 114		remainder <<= 1;
 115		remainder |= (data[array_index] & bitmask) >> bitshift;
 116		bitmask >>= 1;
 117		bitshift--;
 118		if (bitmask == 0) {
 119			bitmask = 0x80;
 120			bitshift = 7;
 121			array_index++;
 122		}
 123		if ((remainder & 0x100) == 0x100)
 124			remainder ^= 0xd5;
 125	}
 126
 127	number_of_bits = 8;
 128	while (number_of_bits != 0) {
 129		number_of_bits--;
 130		remainder <<= 1;
 131		if ((remainder & 0x100) != 0)
 132			remainder ^= 0xd5;
 133	}
 134
 135	return remainder & 0xff;
 136}
 137static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr)
 138{
 139	u8 size = 3;
 140	size += (hdr->lct / 2);
 141	return size;
 142}
 143
 144static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
 145					   u8 *buf, int *len)
 146{
 147	int idx = 0;
 148	int i;
 149	u8 crc4;
 150	buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf);
 151	for (i = 0; i < (hdr->lct / 2); i++)
 152		buf[idx++] = hdr->rad[i];
 153	buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) |
 154		(hdr->msg_len & 0x3f);
 155	buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4);
 156
 157	crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1);
 158	buf[idx - 1] |= (crc4 & 0xf);
 159
 160	*len = idx;
 161}
 162
 163static bool drm_dp_decode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr,
 164					   u8 *buf, int buflen, u8 *hdrlen)
 165{
 166	u8 crc4;
 167	u8 len;
 168	int i;
 169	u8 idx;
 170	if (buf[0] == 0)
 171		return false;
 172	len = 3;
 173	len += ((buf[0] & 0xf0) >> 4) / 2;
 174	if (len > buflen)
 175		return false;
 176	crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1);
 177
 178	if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) {
 179		DRM_DEBUG_KMS("crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]);
 180		return false;
 181	}
 182
 183	hdr->lct = (buf[0] & 0xf0) >> 4;
 184	hdr->lcr = (buf[0] & 0xf);
 185	idx = 1;
 186	for (i = 0; i < (hdr->lct / 2); i++)
 187		hdr->rad[i] = buf[idx++];
 188	hdr->broadcast = (buf[idx] >> 7) & 0x1;
 189	hdr->path_msg = (buf[idx] >> 6) & 0x1;
 190	hdr->msg_len = buf[idx] & 0x3f;
 191	idx++;
 192	hdr->somt = (buf[idx] >> 7) & 0x1;
 193	hdr->eomt = (buf[idx] >> 6) & 0x1;
 194	hdr->seqno = (buf[idx] >> 4) & 0x1;
 195	idx++;
 196	*hdrlen = idx;
 197	return true;
 198}
 199
 200static void drm_dp_encode_sideband_req(struct drm_dp_sideband_msg_req_body *req,
 201				       struct drm_dp_sideband_msg_tx *raw)
 202{
 203	int idx = 0;
 204	int i;
 205	u8 *buf = raw->msg;
 206	buf[idx++] = req->req_type & 0x7f;
 207
 208	switch (req->req_type) {
 209	case DP_ENUM_PATH_RESOURCES:
 210		buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
 211		idx++;
 212		break;
 213	case DP_ALLOCATE_PAYLOAD:
 214		buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 |
 215			(req->u.allocate_payload.number_sdp_streams & 0xf);
 216		idx++;
 217		buf[idx] = (req->u.allocate_payload.vcpi & 0x7f);
 218		idx++;
 219		buf[idx] = (req->u.allocate_payload.pbn >> 8);
 220		idx++;
 221		buf[idx] = (req->u.allocate_payload.pbn & 0xff);
 222		idx++;
 223		for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) {
 224			buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) |
 225				(req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf);
 226			idx++;
 227		}
 228		if (req->u.allocate_payload.number_sdp_streams & 1) {
 229			i = req->u.allocate_payload.number_sdp_streams - 1;
 230			buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4;
 231			idx++;
 232		}
 233		break;
 234	case DP_QUERY_PAYLOAD:
 235		buf[idx] = (req->u.query_payload.port_number & 0xf) << 4;
 236		idx++;
 237		buf[idx] = (req->u.query_payload.vcpi & 0x7f);
 238		idx++;
 239		break;
 240	case DP_REMOTE_DPCD_READ:
 241		buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4;
 242		buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf;
 243		idx++;
 244		buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8;
 245		idx++;
 246		buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff);
 247		idx++;
 248		buf[idx] = (req->u.dpcd_read.num_bytes);
 249		idx++;
 250		break;
 251
 252	case DP_REMOTE_DPCD_WRITE:
 253		buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4;
 254		buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf;
 255		idx++;
 256		buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8;
 257		idx++;
 258		buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff);
 259		idx++;
 260		buf[idx] = (req->u.dpcd_write.num_bytes);
 261		idx++;
 262		memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes);
 263		idx += req->u.dpcd_write.num_bytes;
 264		break;
 265	case DP_REMOTE_I2C_READ:
 266		buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4;
 267		buf[idx] |= (req->u.i2c_read.num_transactions & 0x3);
 268		idx++;
 269		for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) {
 270			buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f;
 271			idx++;
 272			buf[idx] = req->u.i2c_read.transactions[i].num_bytes;
 273			idx++;
 274			memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes);
 275			idx += req->u.i2c_read.transactions[i].num_bytes;
 276
 277			buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 5;
 278			buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf);
 279			idx++;
 280		}
 281		buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f;
 282		idx++;
 283		buf[idx] = (req->u.i2c_read.num_bytes_read);
 284		idx++;
 285		break;
 286
 287	case DP_REMOTE_I2C_WRITE:
 288		buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4;
 289		idx++;
 290		buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f;
 291		idx++;
 292		buf[idx] = (req->u.i2c_write.num_bytes);
 293		idx++;
 294		memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes);
 295		idx += req->u.i2c_write.num_bytes;
 296		break;
 297
 298	case DP_POWER_DOWN_PHY:
 299	case DP_POWER_UP_PHY:
 300		buf[idx] = (req->u.port_num.port_number & 0xf) << 4;
 301		idx++;
 302		break;
 303	}
 304	raw->cur_len = idx;
 305}
 306
 307static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len)
 308{
 309	u8 crc4;
 310	crc4 = drm_dp_msg_data_crc4(msg, len);
 311	msg[len] = crc4;
 312}
 313
 314static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep,
 315					 struct drm_dp_sideband_msg_tx *raw)
 316{
 317	int idx = 0;
 318	u8 *buf = raw->msg;
 319
 320	buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f);
 321
 322	raw->cur_len = idx;
 323}
 324
 325/* this adds a chunk of msg to the builder to get the final msg */
 326static bool drm_dp_sideband_msg_build(struct drm_dp_sideband_msg_rx *msg,
 327				      u8 *replybuf, u8 replybuflen, bool hdr)
 328{
 329	int ret;
 330	u8 crc4;
 331
 332	if (hdr) {
 333		u8 hdrlen;
 334		struct drm_dp_sideband_msg_hdr recv_hdr;
 335		ret = drm_dp_decode_sideband_msg_hdr(&recv_hdr, replybuf, replybuflen, &hdrlen);
 336		if (ret == false) {
 337			print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 1, replybuf, replybuflen, false);
 338			return false;
 339		}
 340
 341		/*
 342		 * ignore out-of-order messages or messages that are part of a
 343		 * failed transaction
 344		 */
 345		if (!recv_hdr.somt && !msg->have_somt)
 346			return false;
 347
 348		/* get length contained in this portion */
 349		msg->curchunk_len = recv_hdr.msg_len;
 350		msg->curchunk_hdrlen = hdrlen;
 351
 352		/* we have already gotten an somt - don't bother parsing */
 353		if (recv_hdr.somt && msg->have_somt)
 354			return false;
 355
 356		if (recv_hdr.somt) {
 357			memcpy(&msg->initial_hdr, &recv_hdr, sizeof(struct drm_dp_sideband_msg_hdr));
 358			msg->have_somt = true;
 359		}
 360		if (recv_hdr.eomt)
 361			msg->have_eomt = true;
 362
 363		/* copy the bytes for the remainder of this header chunk */
 364		msg->curchunk_idx = min(msg->curchunk_len, (u8)(replybuflen - hdrlen));
 365		memcpy(&msg->chunk[0], replybuf + hdrlen, msg->curchunk_idx);
 366	} else {
 367		memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen);
 368		msg->curchunk_idx += replybuflen;
 369	}
 370
 371	if (msg->curchunk_idx >= msg->curchunk_len) {
 372		/* do CRC */
 373		crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1);
 374		/* copy chunk into bigger msg */
 375		memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1);
 376		msg->curlen += msg->curchunk_len - 1;
 377	}
 378	return true;
 379}
 380
 381static bool drm_dp_sideband_parse_link_address(struct drm_dp_sideband_msg_rx *raw,
 382					       struct drm_dp_sideband_msg_reply_body *repmsg)
 383{
 384	int idx = 1;
 385	int i;
 386	memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16);
 387	idx += 16;
 388	repmsg->u.link_addr.nports = raw->msg[idx] & 0xf;
 389	idx++;
 390	if (idx > raw->curlen)
 391		goto fail_len;
 392	for (i = 0; i < repmsg->u.link_addr.nports; i++) {
 393		if (raw->msg[idx] & 0x80)
 394			repmsg->u.link_addr.ports[i].input_port = 1;
 395
 396		repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7;
 397		repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf);
 398
 399		idx++;
 400		if (idx > raw->curlen)
 401			goto fail_len;
 402		repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1;
 403		repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1;
 404		if (repmsg->u.link_addr.ports[i].input_port == 0)
 405			repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
 406		idx++;
 407		if (idx > raw->curlen)
 408			goto fail_len;
 409		if (repmsg->u.link_addr.ports[i].input_port == 0) {
 410			repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]);
 411			idx++;
 412			if (idx > raw->curlen)
 413				goto fail_len;
 414			memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16);
 415			idx += 16;
 416			if (idx > raw->curlen)
 417				goto fail_len;
 418			repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf;
 419			repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf);
 420			idx++;
 421
 422		}
 423		if (idx > raw->curlen)
 424			goto fail_len;
 425	}
 426
 427	return true;
 428fail_len:
 429	DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
 430	return false;
 431}
 432
 433static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw,
 434						   struct drm_dp_sideband_msg_reply_body *repmsg)
 435{
 436	int idx = 1;
 437	repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf;
 438	idx++;
 439	if (idx > raw->curlen)
 440		goto fail_len;
 441	repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx];
 442	if (idx > raw->curlen)
 443		goto fail_len;
 444
 445	memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes);
 446	return true;
 447fail_len:
 448	DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen);
 449	return false;
 450}
 451
 452static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw,
 453						      struct drm_dp_sideband_msg_reply_body *repmsg)
 454{
 455	int idx = 1;
 456	repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf;
 457	idx++;
 458	if (idx > raw->curlen)
 459		goto fail_len;
 460	return true;
 461fail_len:
 462	DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen);
 463	return false;
 464}
 465
 466static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw,
 467						      struct drm_dp_sideband_msg_reply_body *repmsg)
 468{
 469	int idx = 1;
 470
 471	repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf);
 472	idx++;
 473	if (idx > raw->curlen)
 474		goto fail_len;
 475	repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx];
 476	idx++;
 477	/* TODO check */
 478	memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes);
 479	return true;
 480fail_len:
 481	DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen);
 482	return false;
 483}
 484
 485static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw,
 486							  struct drm_dp_sideband_msg_reply_body *repmsg)
 487{
 488	int idx = 1;
 489	repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf;
 490	idx++;
 491	if (idx > raw->curlen)
 492		goto fail_len;
 493	repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 494	idx += 2;
 495	if (idx > raw->curlen)
 496		goto fail_len;
 497	repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 498	idx += 2;
 499	if (idx > raw->curlen)
 500		goto fail_len;
 501	return true;
 502fail_len:
 503	DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen);
 504	return false;
 505}
 506
 507static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw,
 508							  struct drm_dp_sideband_msg_reply_body *repmsg)
 509{
 510	int idx = 1;
 511	repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
 512	idx++;
 513	if (idx > raw->curlen)
 514		goto fail_len;
 515	repmsg->u.allocate_payload.vcpi = raw->msg[idx];
 516	idx++;
 517	if (idx > raw->curlen)
 518		goto fail_len;
 519	repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]);
 520	idx += 2;
 521	if (idx > raw->curlen)
 522		goto fail_len;
 523	return true;
 524fail_len:
 525	DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen);
 526	return false;
 527}
 528
 529static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw,
 530						    struct drm_dp_sideband_msg_reply_body *repmsg)
 531{
 532	int idx = 1;
 533	repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf;
 534	idx++;
 535	if (idx > raw->curlen)
 536		goto fail_len;
 537	repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
 538	idx += 2;
 539	if (idx > raw->curlen)
 540		goto fail_len;
 541	return true;
 542fail_len:
 543	DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen);
 544	return false;
 545}
 546
 547static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw,
 548						       struct drm_dp_sideband_msg_reply_body *repmsg)
 549{
 550	int idx = 1;
 551
 552	repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf;
 553	idx++;
 554	if (idx > raw->curlen) {
 555		DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n",
 556			      idx, raw->curlen);
 557		return false;
 558	}
 559	return true;
 560}
 561
 562static bool drm_dp_sideband_parse_reply(struct drm_dp_sideband_msg_rx *raw,
 563					struct drm_dp_sideband_msg_reply_body *msg)
 564{
 565	memset(msg, 0, sizeof(*msg));
 566	msg->reply_type = (raw->msg[0] & 0x80) >> 7;
 567	msg->req_type = (raw->msg[0] & 0x7f);
 568
 569	if (msg->reply_type) {
 570		memcpy(msg->u.nak.guid, &raw->msg[1], 16);
 571		msg->u.nak.reason = raw->msg[17];
 572		msg->u.nak.nak_data = raw->msg[18];
 573		return false;
 574	}
 575
 576	switch (msg->req_type) {
 577	case DP_LINK_ADDRESS:
 578		return drm_dp_sideband_parse_link_address(raw, msg);
 579	case DP_QUERY_PAYLOAD:
 580		return drm_dp_sideband_parse_query_payload_ack(raw, msg);
 581	case DP_REMOTE_DPCD_READ:
 582		return drm_dp_sideband_parse_remote_dpcd_read(raw, msg);
 583	case DP_REMOTE_DPCD_WRITE:
 584		return drm_dp_sideband_parse_remote_dpcd_write(raw, msg);
 585	case DP_REMOTE_I2C_READ:
 586		return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg);
 587	case DP_ENUM_PATH_RESOURCES:
 588		return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg);
 589	case DP_ALLOCATE_PAYLOAD:
 590		return drm_dp_sideband_parse_allocate_payload_ack(raw, msg);
 591	case DP_POWER_DOWN_PHY:
 592	case DP_POWER_UP_PHY:
 593		return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg);
 594	default:
 595		DRM_ERROR("Got unknown reply 0x%02x\n", msg->req_type);
 596		return false;
 597	}
 598}
 599
 600static bool drm_dp_sideband_parse_connection_status_notify(struct drm_dp_sideband_msg_rx *raw,
 601							   struct drm_dp_sideband_msg_req_body *msg)
 602{
 603	int idx = 1;
 604
 605	msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
 606	idx++;
 607	if (idx > raw->curlen)
 608		goto fail_len;
 609
 610	memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16);
 611	idx += 16;
 612	if (idx > raw->curlen)
 613		goto fail_len;
 614
 615	msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1;
 616	msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1;
 617	msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1;
 618	msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1;
 619	msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7);
 620	idx++;
 621	return true;
 622fail_len:
 623	DRM_DEBUG_KMS("connection status reply parse length fail %d %d\n", idx, raw->curlen);
 624	return false;
 625}
 626
 627static bool drm_dp_sideband_parse_resource_status_notify(struct drm_dp_sideband_msg_rx *raw,
 628							   struct drm_dp_sideband_msg_req_body *msg)
 629{
 630	int idx = 1;
 631
 632	msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4;
 633	idx++;
 634	if (idx > raw->curlen)
 635		goto fail_len;
 636
 637	memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16);
 638	idx += 16;
 639	if (idx > raw->curlen)
 640		goto fail_len;
 641
 642	msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]);
 643	idx++;
 644	return true;
 645fail_len:
 646	DRM_DEBUG_KMS("resource status reply parse length fail %d %d\n", idx, raw->curlen);
 647	return false;
 648}
 649
 650static bool drm_dp_sideband_parse_req(struct drm_dp_sideband_msg_rx *raw,
 651				      struct drm_dp_sideband_msg_req_body *msg)
 652{
 653	memset(msg, 0, sizeof(*msg));
 654	msg->req_type = (raw->msg[0] & 0x7f);
 655
 656	switch (msg->req_type) {
 657	case DP_CONNECTION_STATUS_NOTIFY:
 658		return drm_dp_sideband_parse_connection_status_notify(raw, msg);
 659	case DP_RESOURCE_STATUS_NOTIFY:
 660		return drm_dp_sideband_parse_resource_status_notify(raw, msg);
 661	default:
 662		DRM_ERROR("Got unknown request 0x%02x\n", msg->req_type);
 663		return false;
 664	}
 665}
 666
 667static int build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes, u8 *bytes)
 668{
 669	struct drm_dp_sideband_msg_req_body req;
 670
 671	req.req_type = DP_REMOTE_DPCD_WRITE;
 672	req.u.dpcd_write.port_number = port_num;
 673	req.u.dpcd_write.dpcd_address = offset;
 674	req.u.dpcd_write.num_bytes = num_bytes;
 675	req.u.dpcd_write.bytes = bytes;
 676	drm_dp_encode_sideband_req(&req, msg);
 677
 678	return 0;
 679}
 680
 681static int build_link_address(struct drm_dp_sideband_msg_tx *msg)
 682{
 683	struct drm_dp_sideband_msg_req_body req;
 684
 685	req.req_type = DP_LINK_ADDRESS;
 686	drm_dp_encode_sideband_req(&req, msg);
 687	return 0;
 688}
 689
 690static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, int port_num)
 691{
 692	struct drm_dp_sideband_msg_req_body req;
 693
 694	req.req_type = DP_ENUM_PATH_RESOURCES;
 695	req.u.port_num.port_number = port_num;
 696	drm_dp_encode_sideband_req(&req, msg);
 697	msg->path_msg = true;
 698	return 0;
 699}
 700
 701static int build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, int port_num,
 702				  u8 vcpi, uint16_t pbn,
 703				  u8 number_sdp_streams,
 704				  u8 *sdp_stream_sink)
 705{
 706	struct drm_dp_sideband_msg_req_body req;
 707	memset(&req, 0, sizeof(req));
 708	req.req_type = DP_ALLOCATE_PAYLOAD;
 709	req.u.allocate_payload.port_number = port_num;
 710	req.u.allocate_payload.vcpi = vcpi;
 711	req.u.allocate_payload.pbn = pbn;
 712	req.u.allocate_payload.number_sdp_streams = number_sdp_streams;
 713	memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink,
 714		   number_sdp_streams);
 715	drm_dp_encode_sideband_req(&req, msg);
 716	msg->path_msg = true;
 717	return 0;
 718}
 719
 720static int build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg,
 721				  int port_num, bool power_up)
 722{
 723	struct drm_dp_sideband_msg_req_body req;
 724
 725	if (power_up)
 726		req.req_type = DP_POWER_UP_PHY;
 727	else
 728		req.req_type = DP_POWER_DOWN_PHY;
 729
 730	req.u.port_num.port_number = port_num;
 731	drm_dp_encode_sideband_req(&req, msg);
 732	msg->path_msg = true;
 733	return 0;
 734}
 735
 736static int drm_dp_mst_assign_payload_id(struct drm_dp_mst_topology_mgr *mgr,
 737					struct drm_dp_vcpi *vcpi)
 738{
 739	int ret, vcpi_ret;
 740
 741	mutex_lock(&mgr->payload_lock);
 742	ret = find_first_zero_bit(&mgr->payload_mask, mgr->max_payloads + 1);
 743	if (ret > mgr->max_payloads) {
 744		ret = -EINVAL;
 745		DRM_DEBUG_KMS("out of payload ids %d\n", ret);
 746		goto out_unlock;
 747	}
 748
 749	vcpi_ret = find_first_zero_bit(&mgr->vcpi_mask, mgr->max_payloads + 1);
 750	if (vcpi_ret > mgr->max_payloads) {
 751		ret = -EINVAL;
 752		DRM_DEBUG_KMS("out of vcpi ids %d\n", ret);
 753		goto out_unlock;
 754	}
 755
 756	set_bit(ret, &mgr->payload_mask);
 757	set_bit(vcpi_ret, &mgr->vcpi_mask);
 758	vcpi->vcpi = vcpi_ret + 1;
 759	mgr->proposed_vcpis[ret - 1] = vcpi;
 760out_unlock:
 761	mutex_unlock(&mgr->payload_lock);
 762	return ret;
 763}
 764
 765static void drm_dp_mst_put_payload_id(struct drm_dp_mst_topology_mgr *mgr,
 766				      int vcpi)
 767{
 768	int i;
 769	if (vcpi == 0)
 770		return;
 771
 772	mutex_lock(&mgr->payload_lock);
 773	DRM_DEBUG_KMS("putting payload %d\n", vcpi);
 774	clear_bit(vcpi - 1, &mgr->vcpi_mask);
 775
 776	for (i = 0; i < mgr->max_payloads; i++) {
 777		if (mgr->proposed_vcpis[i])
 778			if (mgr->proposed_vcpis[i]->vcpi == vcpi) {
 779				mgr->proposed_vcpis[i] = NULL;
 780				clear_bit(i + 1, &mgr->payload_mask);
 781			}
 782	}
 783	mutex_unlock(&mgr->payload_lock);
 784}
 785
 786static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr,
 787			      struct drm_dp_sideband_msg_tx *txmsg)
 788{
 789	unsigned int state;
 790
 791	/*
 792	 * All updates to txmsg->state are protected by mgr->qlock, and the two
 793	 * cases we check here are terminal states. For those the barriers
 794	 * provided by the wake_up/wait_event pair are enough.
 795	 */
 796	state = READ_ONCE(txmsg->state);
 797	return (state == DRM_DP_SIDEBAND_TX_RX ||
 798		state == DRM_DP_SIDEBAND_TX_TIMEOUT);
 799}
 800
 801static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb,
 802				    struct drm_dp_sideband_msg_tx *txmsg)
 803{
 804	struct drm_dp_mst_topology_mgr *mgr = mstb->mgr;
 805	int ret;
 806
 807	ret = wait_event_timeout(mgr->tx_waitq,
 808				 check_txmsg_state(mgr, txmsg),
 809				 (4 * HZ));
 810	mutex_lock(&mstb->mgr->qlock);
 811	if (ret > 0) {
 812		if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) {
 813			ret = -EIO;
 814			goto out;
 815		}
 816	} else {
 817		DRM_DEBUG_KMS("timedout msg send %p %d %d\n", txmsg, txmsg->state, txmsg->seqno);
 818
 819		/* dump some state */
 820		ret = -EIO;
 821
 822		/* remove from q */
 823		if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED ||
 824		    txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) {
 825			list_del(&txmsg->next);
 826		}
 827
 828		if (txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND ||
 829		    txmsg->state == DRM_DP_SIDEBAND_TX_SENT) {
 830			mstb->tx_slots[txmsg->seqno] = NULL;
 831		}
 832	}
 833out:
 834	mutex_unlock(&mgr->qlock);
 835
 836	return ret;
 837}
 838
 839static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad)
 840{
 841	struct drm_dp_mst_branch *mstb;
 842
 843	mstb = kzalloc(sizeof(*mstb), GFP_KERNEL);
 844	if (!mstb)
 845		return NULL;
 846
 847	mstb->lct = lct;
 848	if (lct > 1)
 849		memcpy(mstb->rad, rad, lct / 2);
 850	INIT_LIST_HEAD(&mstb->ports);
 851	kref_init(&mstb->kref);
 852	return mstb;
 853}
 854
 855static void drm_dp_free_mst_port(struct kref *kref);
 856
 857static void drm_dp_free_mst_branch_device(struct kref *kref)
 858{
 859	struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
 860	if (mstb->port_parent) {
 861		if (list_empty(&mstb->port_parent->next))
 862			kref_put(&mstb->port_parent->kref, drm_dp_free_mst_port);
 863	}
 864	kfree(mstb);
 865}
 866
 867static void drm_dp_destroy_mst_branch_device(struct kref *kref)
 868{
 869	struct drm_dp_mst_branch *mstb = container_of(kref, struct drm_dp_mst_branch, kref);
 870	struct drm_dp_mst_port *port, *tmp;
 871	bool wake_tx = false;
 872
 873	/*
 874	 * init kref again to be used by ports to remove mst branch when it is
 875	 * not needed anymore
 876	 */
 877	kref_init(kref);
 878
 879	if (mstb->port_parent && list_empty(&mstb->port_parent->next))
 880		kref_get(&mstb->port_parent->kref);
 881
 882	/*
 883	 * destroy all ports - don't need lock
 884	 * as there are no more references to the mst branch
 885	 * device at this point.
 886	 */
 887	list_for_each_entry_safe(port, tmp, &mstb->ports, next) {
 888		list_del(&port->next);
 889		drm_dp_put_port(port);
 890	}
 891
 892	/* drop any tx slots msg */
 893	mutex_lock(&mstb->mgr->qlock);
 894	if (mstb->tx_slots[0]) {
 895		mstb->tx_slots[0]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 896		mstb->tx_slots[0] = NULL;
 897		wake_tx = true;
 898	}
 899	if (mstb->tx_slots[1]) {
 900		mstb->tx_slots[1]->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
 901		mstb->tx_slots[1] = NULL;
 902		wake_tx = true;
 903	}
 904	mutex_unlock(&mstb->mgr->qlock);
 905
 906	if (wake_tx)
 907		wake_up_all(&mstb->mgr->tx_waitq);
 908
 909	kref_put(kref, drm_dp_free_mst_branch_device);
 910}
 911
 912static void drm_dp_put_mst_branch_device(struct drm_dp_mst_branch *mstb)
 913{
 914	kref_put(&mstb->kref, drm_dp_destroy_mst_branch_device);
 915}
 916
 917
 918static void drm_dp_port_teardown_pdt(struct drm_dp_mst_port *port, int old_pdt)
 919{
 920	struct drm_dp_mst_branch *mstb;
 921
 922	switch (old_pdt) {
 923	case DP_PEER_DEVICE_DP_LEGACY_CONV:
 924	case DP_PEER_DEVICE_SST_SINK:
 925		/* remove i2c over sideband */
 926		drm_dp_mst_unregister_i2c_bus(&port->aux);
 927		break;
 928	case DP_PEER_DEVICE_MST_BRANCHING:
 929		mstb = port->mstb;
 930		port->mstb = NULL;
 931		drm_dp_put_mst_branch_device(mstb);
 932		break;
 933	}
 934}
 935
 936static void drm_dp_destroy_port(struct kref *kref)
 937{
 938	struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
 939	struct drm_dp_mst_topology_mgr *mgr = port->mgr;
 940
 941	if (!port->input) {
 942		port->vcpi.num_slots = 0;
 943
 944		kfree(port->cached_edid);
 945
 946		/*
 947		 * The only time we don't have a connector
 948		 * on an output port is if the connector init
 949		 * fails.
 950		 */
 951		if (port->connector) {
 952			/* we can't destroy the connector here, as
 953			 * we might be holding the mode_config.mutex
 954			 * from an EDID retrieval */
 955
 956			mutex_lock(&mgr->destroy_connector_lock);
 957			kref_get(&port->parent->kref);
 958			list_add(&port->next, &mgr->destroy_connector_list);
 959			mutex_unlock(&mgr->destroy_connector_lock);
 960			schedule_work(&mgr->destroy_connector_work);
 961			return;
 962		}
 963		/* no need to clean up vcpi
 964		 * as if we have no connector we never setup a vcpi */
 965		drm_dp_port_teardown_pdt(port, port->pdt);
 966		port->pdt = DP_PEER_DEVICE_NONE;
 967	}
 968	kfree(port);
 969}
 970
 971static void drm_dp_put_port(struct drm_dp_mst_port *port)
 972{
 973	kref_put(&port->kref, drm_dp_destroy_port);
 974}
 975
 976static struct drm_dp_mst_branch *drm_dp_mst_get_validated_mstb_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_branch *to_find)
 977{
 978	struct drm_dp_mst_port *port;
 979	struct drm_dp_mst_branch *rmstb;
 980	if (to_find == mstb) {
 981		kref_get(&mstb->kref);
 982		return mstb;
 983	}
 984	list_for_each_entry(port, &mstb->ports, next) {
 985		if (port->mstb) {
 986			rmstb = drm_dp_mst_get_validated_mstb_ref_locked(port->mstb, to_find);
 987			if (rmstb)
 988				return rmstb;
 989		}
 990	}
 991	return NULL;
 992}
 993
 994static struct drm_dp_mst_branch *drm_dp_get_validated_mstb_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_branch *mstb)
 995{
 996	struct drm_dp_mst_branch *rmstb = NULL;
 997	mutex_lock(&mgr->lock);
 998	if (mgr->mst_primary)
 999		rmstb = drm_dp_mst_get_validated_mstb_ref_locked(mgr->mst_primary, mstb);
1000	mutex_unlock(&mgr->lock);
1001	return rmstb;
1002}
1003
1004static struct drm_dp_mst_port *drm_dp_mst_get_port_ref_locked(struct drm_dp_mst_branch *mstb, struct drm_dp_mst_port *to_find)
1005{
1006	struct drm_dp_mst_port *port, *mport;
1007
1008	list_for_each_entry(port, &mstb->ports, next) {
1009		if (port == to_find) {
1010			kref_get(&port->kref);
1011			return port;
1012		}
1013		if (port->mstb) {
1014			mport = drm_dp_mst_get_port_ref_locked(port->mstb, to_find);
1015			if (mport)
1016				return mport;
1017		}
1018	}
1019	return NULL;
1020}
1021
1022static struct drm_dp_mst_port *drm_dp_get_validated_port_ref(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
1023{
1024	struct drm_dp_mst_port *rport = NULL;
1025	mutex_lock(&mgr->lock);
1026	if (mgr->mst_primary)
1027		rport = drm_dp_mst_get_port_ref_locked(mgr->mst_primary, port);
1028	mutex_unlock(&mgr->lock);
1029	return rport;
1030}
1031
1032static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num)
1033{
1034	struct drm_dp_mst_port *port;
1035
1036	list_for_each_entry(port, &mstb->ports, next) {
1037		if (port->port_num == port_num) {
1038			kref_get(&port->kref);
1039			return port;
1040		}
1041	}
1042
1043	return NULL;
1044}
1045
1046/*
1047 * calculate a new RAD for this MST branch device
1048 * if parent has an LCT of 2 then it has 1 nibble of RAD,
1049 * if parent has an LCT of 3 then it has 2 nibbles of RAD,
1050 */
1051static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port,
1052				 u8 *rad)
1053{
1054	int parent_lct = port->parent->lct;
1055	int shift = 4;
1056	int idx = (parent_lct - 1) / 2;
1057	if (parent_lct > 1) {
1058		memcpy(rad, port->parent->rad, idx + 1);
1059		shift = (parent_lct % 2) ? 4 : 0;
1060	} else
1061		rad[0] = 0;
1062
1063	rad[idx] |= port->port_num << shift;
1064	return parent_lct + 1;
1065}
1066
1067/*
1068 * return sends link address for new mstb
1069 */
1070static bool drm_dp_port_setup_pdt(struct drm_dp_mst_port *port)
1071{
1072	int ret;
1073	u8 rad[6], lct;
1074	bool send_link = false;
1075	switch (port->pdt) {
1076	case DP_PEER_DEVICE_DP_LEGACY_CONV:
1077	case DP_PEER_DEVICE_SST_SINK:
1078		/* add i2c over sideband */
1079		ret = drm_dp_mst_register_i2c_bus(&port->aux);
1080		break;
1081	case DP_PEER_DEVICE_MST_BRANCHING:
1082		lct = drm_dp_calculate_rad(port, rad);
1083
1084		port->mstb = drm_dp_add_mst_branch_device(lct, rad);
1085		if (port->mstb) {
1086			port->mstb->mgr = port->mgr;
1087			port->mstb->port_parent = port;
1088
1089			send_link = true;
1090		}
1091		break;
1092	}
1093	return send_link;
1094}
1095
1096static void drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid)
1097{
1098	int ret;
1099
1100	memcpy(mstb->guid, guid, 16);
1101
1102	if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) {
1103		if (mstb->port_parent) {
1104			ret = drm_dp_send_dpcd_write(
1105					mstb->mgr,
1106					mstb->port_parent,
1107					DP_GUID,
1108					16,
1109					mstb->guid);
1110		} else {
1111
1112			ret = drm_dp_dpcd_write(
1113					mstb->mgr->aux,
1114					DP_GUID,
1115					mstb->guid,
1116					16);
1117		}
1118	}
1119}
1120
1121static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb,
1122				int pnum,
1123				char *proppath,
1124				size_t proppath_size)
1125{
1126	int i;
1127	char temp[8];
1128	snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id);
1129	for (i = 0; i < (mstb->lct - 1); i++) {
1130		int shift = (i % 2) ? 0 : 4;
1131		int port_num = (mstb->rad[i / 2] >> shift) & 0xf;
1132		snprintf(temp, sizeof(temp), "-%d", port_num);
1133		strlcat(proppath, temp, proppath_size);
1134	}
1135	snprintf(temp, sizeof(temp), "-%d", pnum);
1136	strlcat(proppath, temp, proppath_size);
1137}
1138
1139static void drm_dp_add_port(struct drm_dp_mst_branch *mstb,
1140			    struct drm_device *dev,
1141			    struct drm_dp_link_addr_reply_port *port_msg)
1142{
1143	struct drm_dp_mst_port *port;
1144	bool ret;
1145	bool created = false;
1146	int old_pdt = 0;
1147	int old_ddps = 0;
1148	port = drm_dp_get_port(mstb, port_msg->port_number);
1149	if (!port) {
1150		port = kzalloc(sizeof(*port), GFP_KERNEL);
1151		if (!port)
1152			return;
1153		kref_init(&port->kref);
1154		port->parent = mstb;
1155		port->port_num = port_msg->port_number;
1156		port->mgr = mstb->mgr;
1157		port->aux.name = "DPMST";
1158		port->aux.dev = dev->dev;
1159		created = true;
1160	} else {
1161		old_pdt = port->pdt;
1162		old_ddps = port->ddps;
1163	}
1164
1165	port->pdt = port_msg->peer_device_type;
1166	port->input = port_msg->input_port;
1167	port->mcs = port_msg->mcs;
1168	port->ddps = port_msg->ddps;
1169	port->ldps = port_msg->legacy_device_plug_status;
1170	port->dpcd_rev = port_msg->dpcd_revision;
1171	port->num_sdp_streams = port_msg->num_sdp_streams;
1172	port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks;
1173
1174	/* manage mstb port lists with mgr lock - take a reference
1175	   for this list */
1176	if (created) {
1177		mutex_lock(&mstb->mgr->lock);
1178		kref_get(&port->kref);
1179		list_add(&port->next, &mstb->ports);
1180		mutex_unlock(&mstb->mgr->lock);
1181	}
1182
1183	if (old_ddps != port->ddps) {
1184		if (port->ddps) {
1185			if (!port->input)
1186				drm_dp_send_enum_path_resources(mstb->mgr, mstb, port);
1187		} else {
1188			port->available_pbn = 0;
1189			}
1190	}
1191
1192	if (old_pdt != port->pdt && !port->input) {
1193		drm_dp_port_teardown_pdt(port, old_pdt);
1194
1195		ret = drm_dp_port_setup_pdt(port);
1196		if (ret == true)
1197			drm_dp_send_link_address(mstb->mgr, port->mstb);
1198	}
1199
1200	if (created && !port->input) {
1201		char proppath[255];
1202
1203		build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath));
1204		port->connector = (*mstb->mgr->cbs->add_connector)(mstb->mgr, port, proppath);
1205		if (!port->connector) {
1206			/* remove it from the port list */
1207			mutex_lock(&mstb->mgr->lock);
1208			list_del(&port->next);
1209			mutex_unlock(&mstb->mgr->lock);
1210			/* drop port list reference */
1211			drm_dp_put_port(port);
1212			goto out;
1213		}
1214		if ((port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV ||
1215		     port->pdt == DP_PEER_DEVICE_SST_SINK) &&
1216		    port->port_num >= DP_MST_LOGICAL_PORT_0) {
1217			port->cached_edid = drm_get_edid(port->connector, &port->aux.ddc);
1218			drm_mode_connector_set_tile_property(port->connector);
1219		}
1220		(*mstb->mgr->cbs->register_connector)(port->connector);
1221	}
1222
1223out:
1224	/* put reference to this port */
1225	drm_dp_put_port(port);
1226}
1227
1228static void drm_dp_update_port(struct drm_dp_mst_branch *mstb,
1229			       struct drm_dp_connection_status_notify *conn_stat)
1230{
1231	struct drm_dp_mst_port *port;
1232	int old_pdt;
1233	int old_ddps;
1234	bool dowork = false;
1235	port = drm_dp_get_port(mstb, conn_stat->port_number);
1236	if (!port)
1237		return;
1238
1239	old_ddps = port->ddps;
1240	old_pdt = port->pdt;
1241	port->pdt = conn_stat->peer_device_type;
1242	port->mcs = conn_stat->message_capability_status;
1243	port->ldps = conn_stat->legacy_device_plug_status;
1244	port->ddps = conn_stat->displayport_device_plug_status;
1245
1246	if (old_ddps != port->ddps) {
1247		if (port->ddps) {
1248			dowork = true;
1249		} else {
1250			port->available_pbn = 0;
1251		}
1252	}
1253	if (old_pdt != port->pdt && !port->input) {
1254		drm_dp_port_teardown_pdt(port, old_pdt);
1255
1256		if (drm_dp_port_setup_pdt(port))
1257			dowork = true;
1258	}
1259
1260	drm_dp_put_port(port);
1261	if (dowork)
1262		queue_work(system_long_wq, &mstb->mgr->work);
1263
1264}
1265
1266static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr,
1267							       u8 lct, u8 *rad)
1268{
1269	struct drm_dp_mst_branch *mstb;
1270	struct drm_dp_mst_port *port;
1271	int i;
1272	/* find the port by iterating down */
1273
1274	mutex_lock(&mgr->lock);
1275	mstb = mgr->mst_primary;
1276
1277	for (i = 0; i < lct - 1; i++) {
1278		int shift = (i % 2) ? 0 : 4;
1279		int port_num = (rad[i / 2] >> shift) & 0xf;
1280
1281		list_for_each_entry(port, &mstb->ports, next) {
1282			if (port->port_num == port_num) {
1283				mstb = port->mstb;
1284				if (!mstb) {
1285					DRM_ERROR("failed to lookup MSTB with lct %d, rad %02x\n", lct, rad[0]);
1286					goto out;
1287				}
1288
1289				break;
1290			}
1291		}
1292	}
1293	kref_get(&mstb->kref);
1294out:
1295	mutex_unlock(&mgr->lock);
1296	return mstb;
1297}
1298
1299static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper(
1300	struct drm_dp_mst_branch *mstb,
1301	uint8_t *guid)
1302{
1303	struct drm_dp_mst_branch *found_mstb;
1304	struct drm_dp_mst_port *port;
1305
1306	if (memcmp(mstb->guid, guid, 16) == 0)
1307		return mstb;
1308
1309
1310	list_for_each_entry(port, &mstb->ports, next) {
1311		if (!port->mstb)
1312			continue;
1313
1314		found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid);
1315
1316		if (found_mstb)
1317			return found_mstb;
1318	}
1319
1320	return NULL;
1321}
1322
1323static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device_by_guid(
1324	struct drm_dp_mst_topology_mgr *mgr,
1325	uint8_t *guid)
1326{
1327	struct drm_dp_mst_branch *mstb;
1328
1329	/* find the port by iterating down */
1330	mutex_lock(&mgr->lock);
1331
1332	mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid);
1333
1334	if (mstb)
1335		kref_get(&mstb->kref);
1336
1337	mutex_unlock(&mgr->lock);
1338	return mstb;
1339}
1340
1341static void drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1342					       struct drm_dp_mst_branch *mstb)
1343{
1344	struct drm_dp_mst_port *port;
1345	struct drm_dp_mst_branch *mstb_child;
1346	if (!mstb->link_address_sent)
1347		drm_dp_send_link_address(mgr, mstb);
1348
1349	list_for_each_entry(port, &mstb->ports, next) {
1350		if (port->input)
1351			continue;
1352
1353		if (!port->ddps)
1354			continue;
1355
1356		if (!port->available_pbn)
1357			drm_dp_send_enum_path_resources(mgr, mstb, port);
1358
1359		if (port->mstb) {
1360			mstb_child = drm_dp_get_validated_mstb_ref(mgr, port->mstb);
1361			if (mstb_child) {
1362				drm_dp_check_and_send_link_address(mgr, mstb_child);
1363				drm_dp_put_mst_branch_device(mstb_child);
1364			}
1365		}
1366	}
1367}
1368
1369static void drm_dp_mst_link_probe_work(struct work_struct *work)
1370{
1371	struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, work);
1372	struct drm_dp_mst_branch *mstb;
1373
1374	mutex_lock(&mgr->lock);
1375	mstb = mgr->mst_primary;
1376	if (mstb) {
1377		kref_get(&mstb->kref);
1378	}
1379	mutex_unlock(&mgr->lock);
1380	if (mstb) {
1381		drm_dp_check_and_send_link_address(mgr, mstb);
1382		drm_dp_put_mst_branch_device(mstb);
1383	}
1384}
1385
1386static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr,
1387				 u8 *guid)
1388{
1389	u64 salt;
1390
1391	if (memchr_inv(guid, 0, 16))
1392		return true;
1393
1394	salt = get_jiffies_64();
1395
1396	memcpy(&guid[0], &salt, sizeof(u64));
1397	memcpy(&guid[8], &salt, sizeof(u64));
1398
1399	return false;
1400}
1401
1402#if 0
1403static int build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, u8 port_num, u32 offset, u8 num_bytes)
1404{
1405	struct drm_dp_sideband_msg_req_body req;
1406
1407	req.req_type = DP_REMOTE_DPCD_READ;
1408	req.u.dpcd_read.port_number = port_num;
1409	req.u.dpcd_read.dpcd_address = offset;
1410	req.u.dpcd_read.num_bytes = num_bytes;
1411	drm_dp_encode_sideband_req(&req, msg);
1412
1413	return 0;
1414}
1415#endif
1416
1417static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr,
1418				    bool up, u8 *msg, int len)
1419{
1420	int ret;
1421	int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE;
1422	int tosend, total, offset;
1423	int retries = 0;
1424
1425retry:
1426	total = len;
1427	offset = 0;
1428	do {
1429		tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total);
1430
1431		ret = drm_dp_dpcd_write(mgr->aux, regbase + offset,
1432					&msg[offset],
1433					tosend);
1434		if (ret != tosend) {
1435			if (ret == -EIO && retries < 5) {
1436				retries++;
1437				goto retry;
1438			}
1439			DRM_DEBUG_KMS("failed to dpcd write %d %d\n", tosend, ret);
1440
1441			return -EIO;
1442		}
1443		offset += tosend;
1444		total -= tosend;
1445	} while (total > 0);
1446	return 0;
1447}
1448
1449static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr,
1450				  struct drm_dp_sideband_msg_tx *txmsg)
1451{
1452	struct drm_dp_mst_branch *mstb = txmsg->dst;
1453	u8 req_type;
1454
1455	/* both msg slots are full */
1456	if (txmsg->seqno == -1) {
1457		if (mstb->tx_slots[0] && mstb->tx_slots[1]) {
1458			DRM_DEBUG_KMS("%s: failed to find slot\n", __func__);
1459			return -EAGAIN;
1460		}
1461		if (mstb->tx_slots[0] == NULL && mstb->tx_slots[1] == NULL) {
1462			txmsg->seqno = mstb->last_seqno;
1463			mstb->last_seqno ^= 1;
1464		} else if (mstb->tx_slots[0] == NULL)
1465			txmsg->seqno = 0;
1466		else
1467			txmsg->seqno = 1;
1468		mstb->tx_slots[txmsg->seqno] = txmsg;
1469	}
1470
1471	req_type = txmsg->msg[0] & 0x7f;
1472	if (req_type == DP_CONNECTION_STATUS_NOTIFY ||
1473		req_type == DP_RESOURCE_STATUS_NOTIFY)
1474		hdr->broadcast = 1;
1475	else
1476		hdr->broadcast = 0;
1477	hdr->path_msg = txmsg->path_msg;
1478	hdr->lct = mstb->lct;
1479	hdr->lcr = mstb->lct - 1;
1480	if (mstb->lct > 1)
1481		memcpy(hdr->rad, mstb->rad, mstb->lct / 2);
1482	hdr->seqno = txmsg->seqno;
1483	return 0;
1484}
1485/*
1486 * process a single block of the next message in the sideband queue
1487 */
1488static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1489				   struct drm_dp_sideband_msg_tx *txmsg,
1490				   bool up)
1491{
1492	u8 chunk[48];
1493	struct drm_dp_sideband_msg_hdr hdr;
1494	int len, space, idx, tosend;
1495	int ret;
1496
1497	memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr));
1498
1499	if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) {
1500		txmsg->seqno = -1;
1501		txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND;
1502	}
1503
1504	/* make hdr from dst mst - for replies use seqno
1505	   otherwise assign one */
1506	ret = set_hdr_from_dst_qlock(&hdr, txmsg);
1507	if (ret < 0)
1508		return ret;
1509
1510	/* amount left to send in this message */
1511	len = txmsg->cur_len - txmsg->cur_offset;
1512
1513	/* 48 - sideband msg size - 1 byte for data CRC, x header bytes */
1514	space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr);
1515
1516	tosend = min(len, space);
1517	if (len == txmsg->cur_len)
1518		hdr.somt = 1;
1519	if (space >= len)
1520		hdr.eomt = 1;
1521
1522
1523	hdr.msg_len = tosend + 1;
1524	drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx);
1525	memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend);
1526	/* add crc at end */
1527	drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend);
1528	idx += tosend + 1;
1529
1530	ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx);
1531	if (ret) {
1532		DRM_DEBUG_KMS("sideband msg failed to send\n");
1533		return ret;
1534	}
1535
1536	txmsg->cur_offset += tosend;
1537	if (txmsg->cur_offset == txmsg->cur_len) {
1538		txmsg->state = DRM_DP_SIDEBAND_TX_SENT;
1539		return 1;
1540	}
1541	return 0;
1542}
1543
1544static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr)
1545{
1546	struct drm_dp_sideband_msg_tx *txmsg;
1547	int ret;
1548
1549	WARN_ON(!mutex_is_locked(&mgr->qlock));
1550
1551	/* construct a chunk from the first msg in the tx_msg queue */
1552	if (list_empty(&mgr->tx_msg_downq))
1553		return;
1554
1555	txmsg = list_first_entry(&mgr->tx_msg_downq, struct drm_dp_sideband_msg_tx, next);
1556	ret = process_single_tx_qlock(mgr, txmsg, false);
1557	if (ret == 1) {
1558		/* txmsg is sent it should be in the slots now */
1559		list_del(&txmsg->next);
1560	} else if (ret) {
1561		DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1562		list_del(&txmsg->next);
1563		if (txmsg->seqno != -1)
1564			txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1565		txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT;
1566		wake_up_all(&mgr->tx_waitq);
1567	}
1568}
1569
1570/* called holding qlock */
1571static void process_single_up_tx_qlock(struct drm_dp_mst_topology_mgr *mgr,
1572				       struct drm_dp_sideband_msg_tx *txmsg)
1573{
1574	int ret;
1575
1576	/* construct a chunk from the first msg in the tx_msg queue */
1577	ret = process_single_tx_qlock(mgr, txmsg, true);
1578
1579	if (ret != 1)
1580		DRM_DEBUG_KMS("failed to send msg in q %d\n", ret);
1581
1582	txmsg->dst->tx_slots[txmsg->seqno] = NULL;
1583}
1584
1585static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr,
1586				 struct drm_dp_sideband_msg_tx *txmsg)
1587{
1588	mutex_lock(&mgr->qlock);
1589	list_add_tail(&txmsg->next, &mgr->tx_msg_downq);
1590	if (list_is_singular(&mgr->tx_msg_downq))
1591		process_single_down_tx_qlock(mgr);
1592	mutex_unlock(&mgr->qlock);
1593}
1594
1595static void drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr,
1596				     struct drm_dp_mst_branch *mstb)
1597{
1598	int len;
1599	struct drm_dp_sideband_msg_tx *txmsg;
1600	int ret;
1601
1602	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1603	if (!txmsg)
1604		return;
1605
1606	txmsg->dst = mstb;
1607	len = build_link_address(txmsg);
1608
1609	mstb->link_address_sent = true;
1610	drm_dp_queue_down_tx(mgr, txmsg);
1611
1612	ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1613	if (ret > 0) {
1614		int i;
1615
1616		if (txmsg->reply.reply_type == 1)
1617			DRM_DEBUG_KMS("link address nak received\n");
1618		else {
1619			DRM_DEBUG_KMS("link address reply: %d\n", txmsg->reply.u.link_addr.nports);
1620			for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1621				DRM_DEBUG_KMS("port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", i,
1622				       txmsg->reply.u.link_addr.ports[i].input_port,
1623				       txmsg->reply.u.link_addr.ports[i].peer_device_type,
1624				       txmsg->reply.u.link_addr.ports[i].port_number,
1625				       txmsg->reply.u.link_addr.ports[i].dpcd_revision,
1626				       txmsg->reply.u.link_addr.ports[i].mcs,
1627				       txmsg->reply.u.link_addr.ports[i].ddps,
1628				       txmsg->reply.u.link_addr.ports[i].legacy_device_plug_status,
1629				       txmsg->reply.u.link_addr.ports[i].num_sdp_streams,
1630				       txmsg->reply.u.link_addr.ports[i].num_sdp_stream_sinks);
1631			}
1632
1633			drm_dp_check_mstb_guid(mstb, txmsg->reply.u.link_addr.guid);
1634
1635			for (i = 0; i < txmsg->reply.u.link_addr.nports; i++) {
1636				drm_dp_add_port(mstb, mgr->dev, &txmsg->reply.u.link_addr.ports[i]);
1637			}
1638			(*mgr->cbs->hotplug)(mgr);
1639		}
1640	} else {
1641		mstb->link_address_sent = false;
1642		DRM_DEBUG_KMS("link address failed %d\n", ret);
1643	}
1644
1645	kfree(txmsg);
1646}
1647
1648static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr,
1649					   struct drm_dp_mst_branch *mstb,
1650					   struct drm_dp_mst_port *port)
1651{
1652	int len;
1653	struct drm_dp_sideband_msg_tx *txmsg;
1654	int ret;
1655
1656	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1657	if (!txmsg)
1658		return -ENOMEM;
1659
1660	txmsg->dst = mstb;
1661	len = build_enum_path_resources(txmsg, port->port_num);
1662
1663	drm_dp_queue_down_tx(mgr, txmsg);
1664
1665	ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1666	if (ret > 0) {
1667		if (txmsg->reply.reply_type == 1)
1668			DRM_DEBUG_KMS("enum path resources nak received\n");
1669		else {
1670			if (port->port_num != txmsg->reply.u.path_resources.port_number)
1671				DRM_ERROR("got incorrect port in response\n");
1672			DRM_DEBUG_KMS("enum path resources %d: %d %d\n", txmsg->reply.u.path_resources.port_number, txmsg->reply.u.path_resources.full_payload_bw_number,
1673			       txmsg->reply.u.path_resources.avail_payload_bw_number);
1674			port->available_pbn = txmsg->reply.u.path_resources.avail_payload_bw_number;
1675		}
1676	}
1677
1678	kfree(txmsg);
1679	return 0;
1680}
1681
1682static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb)
1683{
1684	if (!mstb->port_parent)
1685		return NULL;
1686
1687	if (mstb->port_parent->mstb != mstb)
1688		return mstb->port_parent;
1689
1690	return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent);
1691}
1692
1693static struct drm_dp_mst_branch *drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr,
1694									 struct drm_dp_mst_branch *mstb,
1695									 int *port_num)
1696{
1697	struct drm_dp_mst_branch *rmstb = NULL;
1698	struct drm_dp_mst_port *found_port;
1699	mutex_lock(&mgr->lock);
1700	if (mgr->mst_primary) {
1701		found_port = drm_dp_get_last_connected_port_to_mstb(mstb);
1702
1703		if (found_port) {
1704			rmstb = found_port->parent;
1705			kref_get(&rmstb->kref);
1706			*port_num = found_port->port_num;
1707		}
1708	}
1709	mutex_unlock(&mgr->lock);
1710	return rmstb;
1711}
1712
1713static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr,
1714				   struct drm_dp_mst_port *port,
1715				   int id,
1716				   int pbn)
1717{
1718	struct drm_dp_sideband_msg_tx *txmsg;
1719	struct drm_dp_mst_branch *mstb;
1720	int len, ret, port_num;
1721	u8 sinks[DRM_DP_MAX_SDP_STREAMS];
1722	int i;
1723
1724	port = drm_dp_get_validated_port_ref(mgr, port);
1725	if (!port)
1726		return -EINVAL;
1727
1728	port_num = port->port_num;
1729	mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
1730	if (!mstb) {
1731		mstb = drm_dp_get_last_connected_port_and_mstb(mgr, port->parent, &port_num);
1732
1733		if (!mstb) {
1734			drm_dp_put_port(port);
1735			return -EINVAL;
1736		}
1737	}
1738
1739	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1740	if (!txmsg) {
1741		ret = -ENOMEM;
1742		goto fail_put;
1743	}
1744
1745	for (i = 0; i < port->num_sdp_streams; i++)
1746		sinks[i] = i;
1747
1748	txmsg->dst = mstb;
1749	len = build_allocate_payload(txmsg, port_num,
1750				     id,
1751				     pbn, port->num_sdp_streams, sinks);
1752
1753	drm_dp_queue_down_tx(mgr, txmsg);
1754
1755	ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
1756	if (ret > 0) {
1757		if (txmsg->reply.reply_type == 1) {
1758			ret = -EINVAL;
1759		} else
1760			ret = 0;
1761	}
1762	kfree(txmsg);
1763fail_put:
1764	drm_dp_put_mst_branch_device(mstb);
1765	drm_dp_put_port(port);
1766	return ret;
1767}
1768
1769int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr,
1770				 struct drm_dp_mst_port *port, bool power_up)
1771{
1772	struct drm_dp_sideband_msg_tx *txmsg;
1773	int len, ret;
1774
1775	port = drm_dp_get_validated_port_ref(mgr, port);
1776	if (!port)
1777		return -EINVAL;
1778
1779	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1780	if (!txmsg) {
1781		drm_dp_put_port(port);
1782		return -ENOMEM;
1783	}
1784
1785	txmsg->dst = port->parent;
1786	len = build_power_updown_phy(txmsg, port->port_num, power_up);
1787	drm_dp_queue_down_tx(mgr, txmsg);
1788
1789	ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg);
1790	if (ret > 0) {
1791		if (txmsg->reply.reply_type == 1)
1792			ret = -EINVAL;
1793		else
1794			ret = 0;
1795	}
1796	kfree(txmsg);
1797	drm_dp_put_port(port);
1798
1799	return ret;
1800}
1801EXPORT_SYMBOL(drm_dp_send_power_updown_phy);
1802
1803static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1804				       int id,
1805				       struct drm_dp_payload *payload)
1806{
1807	int ret;
1808
1809	ret = drm_dp_dpcd_write_payload(mgr, id, payload);
1810	if (ret < 0) {
1811		payload->payload_state = 0;
1812		return ret;
1813	}
1814	payload->payload_state = DP_PAYLOAD_LOCAL;
1815	return 0;
1816}
1817
1818static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1819				       struct drm_dp_mst_port *port,
1820				       int id,
1821				       struct drm_dp_payload *payload)
1822{
1823	int ret;
1824	ret = drm_dp_payload_send_msg(mgr, port, id, port->vcpi.pbn);
1825	if (ret < 0)
1826		return ret;
1827	payload->payload_state = DP_PAYLOAD_REMOTE;
1828	return ret;
1829}
1830
1831static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr,
1832					struct drm_dp_mst_port *port,
1833					int id,
1834					struct drm_dp_payload *payload)
1835{
1836	DRM_DEBUG_KMS("\n");
1837	/* its okay for these to fail */
1838	if (port) {
1839		drm_dp_payload_send_msg(mgr, port, id, 0);
1840	}
1841
1842	drm_dp_dpcd_write_payload(mgr, id, payload);
1843	payload->payload_state = DP_PAYLOAD_DELETE_LOCAL;
1844	return 0;
1845}
1846
1847static int drm_dp_destroy_payload_step2(struct drm_dp_mst_topology_mgr *mgr,
1848					int id,
1849					struct drm_dp_payload *payload)
1850{
1851	payload->payload_state = 0;
1852	return 0;
1853}
1854
1855/**
1856 * drm_dp_update_payload_part1() - Execute payload update part 1
1857 * @mgr: manager to use.
1858 *
1859 * This iterates over all proposed virtual channels, and tries to
1860 * allocate space in the link for them. For 0->slots transitions,
1861 * this step just writes the VCPI to the MST device. For slots->0
1862 * transitions, this writes the updated VCPIs and removes the
1863 * remote VC payloads.
1864 *
1865 * after calling this the driver should generate ACT and payload
1866 * packets.
1867 */
1868int drm_dp_update_payload_part1(struct drm_dp_mst_topology_mgr *mgr)
1869{
1870	int i, j;
1871	int cur_slots = 1;
1872	struct drm_dp_payload req_payload;
1873	struct drm_dp_mst_port *port;
1874
1875	mutex_lock(&mgr->payload_lock);
1876	for (i = 0; i < mgr->max_payloads; i++) {
1877		/* solve the current payloads - compare to the hw ones
1878		   - update the hw view */
1879		req_payload.start_slot = cur_slots;
1880		if (mgr->proposed_vcpis[i]) {
1881			port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1882			port = drm_dp_get_validated_port_ref(mgr, port);
1883			if (!port) {
1884				mutex_unlock(&mgr->payload_lock);
1885				return -EINVAL;
1886			}
1887			req_payload.num_slots = mgr->proposed_vcpis[i]->num_slots;
1888			req_payload.vcpi = mgr->proposed_vcpis[i]->vcpi;
1889		} else {
1890			port = NULL;
1891			req_payload.num_slots = 0;
1892		}
1893
1894		if (mgr->payloads[i].start_slot != req_payload.start_slot) {
1895			mgr->payloads[i].start_slot = req_payload.start_slot;
1896		}
1897		/* work out what is required to happen with this payload */
1898		if (mgr->payloads[i].num_slots != req_payload.num_slots) {
1899
1900			/* need to push an update for this payload */
1901			if (req_payload.num_slots) {
1902				drm_dp_create_payload_step1(mgr, mgr->proposed_vcpis[i]->vcpi, &req_payload);
1903				mgr->payloads[i].num_slots = req_payload.num_slots;
1904				mgr->payloads[i].vcpi = req_payload.vcpi;
1905			} else if (mgr->payloads[i].num_slots) {
1906				mgr->payloads[i].num_slots = 0;
1907				drm_dp_destroy_payload_step1(mgr, port, mgr->payloads[i].vcpi, &mgr->payloads[i]);
1908				req_payload.payload_state = mgr->payloads[i].payload_state;
1909				mgr->payloads[i].start_slot = 0;
1910			}
1911			mgr->payloads[i].payload_state = req_payload.payload_state;
1912		}
1913		cur_slots += req_payload.num_slots;
1914
1915		if (port)
1916			drm_dp_put_port(port);
1917	}
1918
1919	for (i = 0; i < mgr->max_payloads; i++) {
1920		if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1921			DRM_DEBUG_KMS("removing payload %d\n", i);
1922			for (j = i; j < mgr->max_payloads - 1; j++) {
1923				memcpy(&mgr->payloads[j], &mgr->payloads[j + 1], sizeof(struct drm_dp_payload));
1924				mgr->proposed_vcpis[j] = mgr->proposed_vcpis[j + 1];
1925				if (mgr->proposed_vcpis[j] && mgr->proposed_vcpis[j]->num_slots) {
1926					set_bit(j + 1, &mgr->payload_mask);
1927				} else {
1928					clear_bit(j + 1, &mgr->payload_mask);
1929				}
1930			}
1931			memset(&mgr->payloads[mgr->max_payloads - 1], 0, sizeof(struct drm_dp_payload));
1932			mgr->proposed_vcpis[mgr->max_payloads - 1] = NULL;
1933			clear_bit(mgr->max_payloads, &mgr->payload_mask);
1934
1935		}
1936	}
1937	mutex_unlock(&mgr->payload_lock);
1938
1939	return 0;
1940}
1941EXPORT_SYMBOL(drm_dp_update_payload_part1);
1942
1943/**
1944 * drm_dp_update_payload_part2() - Execute payload update part 2
1945 * @mgr: manager to use.
1946 *
1947 * This iterates over all proposed virtual channels, and tries to
1948 * allocate space in the link for them. For 0->slots transitions,
1949 * this step writes the remote VC payload commands. For slots->0
1950 * this just resets some internal state.
1951 */
1952int drm_dp_update_payload_part2(struct drm_dp_mst_topology_mgr *mgr)
1953{
1954	struct drm_dp_mst_port *port;
1955	int i;
1956	int ret = 0;
1957	mutex_lock(&mgr->payload_lock);
1958	for (i = 0; i < mgr->max_payloads; i++) {
1959
1960		if (!mgr->proposed_vcpis[i])
1961			continue;
1962
1963		port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
1964
1965		DRM_DEBUG_KMS("payload %d %d\n", i, mgr->payloads[i].payload_state);
1966		if (mgr->payloads[i].payload_state == DP_PAYLOAD_LOCAL) {
1967			ret = drm_dp_create_payload_step2(mgr, port, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1968		} else if (mgr->payloads[i].payload_state == DP_PAYLOAD_DELETE_LOCAL) {
1969			ret = drm_dp_destroy_payload_step2(mgr, mgr->proposed_vcpis[i]->vcpi, &mgr->payloads[i]);
1970		}
1971		if (ret) {
1972			mutex_unlock(&mgr->payload_lock);
1973			return ret;
1974		}
1975	}
1976	mutex_unlock(&mgr->payload_lock);
1977	return 0;
1978}
1979EXPORT_SYMBOL(drm_dp_update_payload_part2);
1980
1981#if 0 /* unused as of yet */
1982static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr,
1983				 struct drm_dp_mst_port *port,
1984				 int offset, int size)
1985{
1986	int len;
1987	struct drm_dp_sideband_msg_tx *txmsg;
1988
1989	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
1990	if (!txmsg)
1991		return -ENOMEM;
1992
1993	len = build_dpcd_read(txmsg, port->port_num, 0, 8);
1994	txmsg->dst = port->parent;
1995
1996	drm_dp_queue_down_tx(mgr, txmsg);
1997
1998	return 0;
1999}
2000#endif
2001
2002static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr,
2003				  struct drm_dp_mst_port *port,
2004				  int offset, int size, u8 *bytes)
2005{
2006	int len;
2007	int ret;
2008	struct drm_dp_sideband_msg_tx *txmsg;
2009	struct drm_dp_mst_branch *mstb;
2010
2011	mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
2012	if (!mstb)
2013		return -EINVAL;
2014
2015	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2016	if (!txmsg) {
2017		ret = -ENOMEM;
2018		goto fail_put;
2019	}
2020
2021	len = build_dpcd_write(txmsg, port->port_num, offset, size, bytes);
2022	txmsg->dst = mstb;
2023
2024	drm_dp_queue_down_tx(mgr, txmsg);
2025
2026	ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
2027	if (ret > 0) {
2028		if (txmsg->reply.reply_type == 1) {
2029			ret = -EINVAL;
2030		} else
2031			ret = 0;
2032	}
2033	kfree(txmsg);
2034fail_put:
2035	drm_dp_put_mst_branch_device(mstb);
2036	return ret;
2037}
2038
2039static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type)
2040{
2041	struct drm_dp_sideband_msg_reply_body reply;
2042
2043	reply.reply_type = 0;
2044	reply.req_type = req_type;
2045	drm_dp_encode_sideband_reply(&reply, msg);
2046	return 0;
2047}
2048
2049static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr,
2050				    struct drm_dp_mst_branch *mstb,
2051				    int req_type, int seqno, bool broadcast)
2052{
2053	struct drm_dp_sideband_msg_tx *txmsg;
2054
2055	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
2056	if (!txmsg)
2057		return -ENOMEM;
2058
2059	txmsg->dst = mstb;
2060	txmsg->seqno = seqno;
2061	drm_dp_encode_up_ack_reply(txmsg, req_type);
2062
2063	mutex_lock(&mgr->qlock);
2064
2065	process_single_up_tx_qlock(mgr, txmsg);
2066
2067	mutex_unlock(&mgr->qlock);
2068
2069	kfree(txmsg);
2070	return 0;
2071}
2072
2073static bool drm_dp_get_vc_payload_bw(int dp_link_bw,
2074				     int dp_link_count,
2075				     int *out)
2076{
2077	switch (dp_link_bw) {
2078	default:
2079		DRM_DEBUG_KMS("invalid link bandwidth in DPCD: %x (link count: %d)\n",
2080			      dp_link_bw, dp_link_count);
2081		return false;
2082
2083	case DP_LINK_BW_1_62:
2084		*out = 3 * dp_link_count;
2085		break;
2086	case DP_LINK_BW_2_7:
2087		*out = 5 * dp_link_count;
2088		break;
2089	case DP_LINK_BW_5_4:
2090		*out = 10 * dp_link_count;
2091		break;
2092	case DP_LINK_BW_8_1:
2093		*out = 15 * dp_link_count;
2094		break;
2095	}
2096	return true;
2097}
2098
2099/**
2100 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager
2101 * @mgr: manager to set state for
2102 * @mst_state: true to enable MST on this connector - false to disable.
2103 *
2104 * This is called by the driver when it detects an MST capable device plugged
2105 * into a DP MST capable port, or when a DP MST capable device is unplugged.
2106 */
2107int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state)
2108{
2109	int ret = 0;
2110	struct drm_dp_mst_branch *mstb = NULL;
2111
2112	mutex_lock(&mgr->lock);
2113	if (mst_state == mgr->mst_state)
2114		goto out_unlock;
2115
2116	mgr->mst_state = mst_state;
2117	/* set the device into MST mode */
2118	if (mst_state) {
2119		WARN_ON(mgr->mst_primary);
2120
2121		/* get dpcd info */
2122		ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2123		if (ret != DP_RECEIVER_CAP_SIZE) {
2124			DRM_DEBUG_KMS("failed to read DPCD\n");
2125			goto out_unlock;
2126		}
2127
2128		if (!drm_dp_get_vc_payload_bw(mgr->dpcd[1],
2129					      mgr->dpcd[2] & DP_MAX_LANE_COUNT_MASK,
2130					      &mgr->pbn_div)) {
2131			ret = -EINVAL;
2132			goto out_unlock;
2133		}
2134
2135		/* add initial branch device at LCT 1 */
2136		mstb = drm_dp_add_mst_branch_device(1, NULL);
2137		if (mstb == NULL) {
2138			ret = -ENOMEM;
2139			goto out_unlock;
2140		}
2141		mstb->mgr = mgr;
2142
2143		/* give this the main reference */
2144		mgr->mst_primary = mstb;
2145		kref_get(&mgr->mst_primary->kref);
2146
2147		ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2148							 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2149		if (ret < 0) {
2150			goto out_unlock;
2151		}
2152
2153		{
2154			struct drm_dp_payload reset_pay;
2155			reset_pay.start_slot = 0;
2156			reset_pay.num_slots = 0x3f;
2157			drm_dp_dpcd_write_payload(mgr, 0, &reset_pay);
2158		}
2159
2160		queue_work(system_long_wq, &mgr->work);
2161
2162		ret = 0;
2163	} else {
2164		/* disable MST on the device */
2165		mstb = mgr->mst_primary;
2166		mgr->mst_primary = NULL;
2167		/* this can fail if the device is gone */
2168		drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0);
2169		ret = 0;
2170		memset(mgr->payloads, 0, mgr->max_payloads * sizeof(struct drm_dp_payload));
2171		mgr->payload_mask = 0;
2172		set_bit(0, &mgr->payload_mask);
2173		mgr->vcpi_mask = 0;
2174	}
2175
2176out_unlock:
2177	mutex_unlock(&mgr->lock);
2178	if (mstb)
2179		drm_dp_put_mst_branch_device(mstb);
2180	return ret;
2181
2182}
2183EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst);
2184
2185/**
2186 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager
2187 * @mgr: manager to suspend
2188 *
2189 * This function tells the MST device that we can't handle UP messages
2190 * anymore. This should stop it from sending any since we are suspended.
2191 */
2192void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr)
2193{
2194	mutex_lock(&mgr->lock);
2195	drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2196			   DP_MST_EN | DP_UPSTREAM_IS_SRC);
2197	mutex_unlock(&mgr->lock);
2198	flush_work(&mgr->work);
2199	flush_work(&mgr->destroy_connector_work);
2200}
2201EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend);
2202
2203/**
2204 * drm_dp_mst_topology_mgr_resume() - resume the MST manager
2205 * @mgr: manager to resume
2206 *
2207 * This will fetch DPCD and see if the device is still there,
2208 * if it is, it will rewrite the MSTM control bits, and return.
2209 *
2210 * if the device fails this returns -1, and the driver should do
2211 * a full MST reprobe, in case we were undocked.
2212 */
2213int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr)
2214{
2215	int ret = 0;
2216
2217	mutex_lock(&mgr->lock);
2218
2219	if (mgr->mst_primary) {
2220		int sret;
2221		u8 guid[16];
2222
2223		sret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, mgr->dpcd, DP_RECEIVER_CAP_SIZE);
2224		if (sret != DP_RECEIVER_CAP_SIZE) {
2225			DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2226			ret = -1;
2227			goto out_unlock;
2228		}
2229
2230		ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL,
2231					 DP_MST_EN | DP_UP_REQ_EN | DP_UPSTREAM_IS_SRC);
2232		if (ret < 0) {
2233			DRM_DEBUG_KMS("mst write failed - undocked during suspend?\n");
2234			ret = -1;
2235			goto out_unlock;
2236		}
2237
2238		/* Some hubs forget their guids after they resume */
2239		sret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16);
2240		if (sret != 16) {
2241			DRM_DEBUG_KMS("dpcd read failed - undocked during suspend?\n");
2242			ret = -1;
2243			goto out_unlock;
2244		}
2245		drm_dp_check_mstb_guid(mgr->mst_primary, guid);
2246
2247		ret = 0;
2248	} else
2249		ret = -1;
2250
2251out_unlock:
2252	mutex_unlock(&mgr->lock);
2253	return ret;
2254}
2255EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume);
2256
2257static bool drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up)
2258{
2259	int len;
2260	u8 replyblock[32];
2261	int replylen, origlen, curreply;
2262	int ret;
2263	struct drm_dp_sideband_msg_rx *msg;
2264	int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : DP_SIDEBAND_MSG_DOWN_REP_BASE;
2265	msg = up ? &mgr->up_req_recv : &mgr->down_rep_recv;
2266
2267	len = min(mgr->max_dpcd_transaction_bytes, 16);
2268	ret = drm_dp_dpcd_read(mgr->aux, basereg,
2269			       replyblock, len);
2270	if (ret != len) {
2271		DRM_DEBUG_KMS("failed to read DPCD down rep %d %d\n", len, ret);
2272		return false;
2273	}
2274	ret = drm_dp_sideband_msg_build(msg, replyblock, len, true);
2275	if (!ret) {
2276		DRM_DEBUG_KMS("sideband msg build failed %d\n", replyblock[0]);
2277		return false;
2278	}
2279	replylen = msg->curchunk_len + msg->curchunk_hdrlen;
2280
2281	origlen = replylen;
2282	replylen -= len;
2283	curreply = len;
2284	while (replylen > 0) {
2285		len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16);
2286		ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply,
2287				    replyblock, len);
2288		if (ret != len) {
2289			DRM_DEBUG_KMS("failed to read a chunk (len %d, ret %d)\n",
2290				      len, ret);
2291			return false;
2292		}
2293
2294		ret = drm_dp_sideband_msg_build(msg, replyblock, len, false);
2295		if (!ret) {
2296			DRM_DEBUG_KMS("failed to build sideband msg\n");
2297			return false;
2298		}
2299
2300		curreply += len;
2301		replylen -= len;
2302	}
2303	return true;
2304}
2305
2306static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr)
2307{
2308	int ret = 0;
2309
2310	if (!drm_dp_get_one_sb_msg(mgr, false)) {
2311		memset(&mgr->down_rep_recv, 0,
2312		       sizeof(struct drm_dp_sideband_msg_rx));
2313		return 0;
2314	}
2315
2316	if (mgr->down_rep_recv.have_eomt) {
2317		struct drm_dp_sideband_msg_tx *txmsg;
2318		struct drm_dp_mst_branch *mstb;
2319		int slot = -1;
2320		mstb = drm_dp_get_mst_branch_device(mgr,
2321						    mgr->down_rep_recv.initial_hdr.lct,
2322						    mgr->down_rep_recv.initial_hdr.rad);
2323
2324		if (!mstb) {
2325			DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->down_rep_recv.initial_hdr.lct);
2326			memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2327			return 0;
2328		}
2329
2330		/* find the message */
2331		slot = mgr->down_rep_recv.initial_hdr.seqno;
2332		mutex_lock(&mgr->qlock);
2333		txmsg = mstb->tx_slots[slot];
2334		/* remove from slots */
2335		mutex_unlock(&mgr->qlock);
2336
2337		if (!txmsg) {
2338			DRM_DEBUG_KMS("Got MST reply with no msg %p %d %d %02x %02x\n",
2339			       mstb,
2340			       mgr->down_rep_recv.initial_hdr.seqno,
2341			       mgr->down_rep_recv.initial_hdr.lct,
2342				      mgr->down_rep_recv.initial_hdr.rad[0],
2343				      mgr->down_rep_recv.msg[0]);
2344			drm_dp_put_mst_branch_device(mstb);
2345			memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2346			return 0;
2347		}
2348
2349		drm_dp_sideband_parse_reply(&mgr->down_rep_recv, &txmsg->reply);
2350		if (txmsg->reply.reply_type == 1) {
2351			DRM_DEBUG_KMS("Got NAK reply: req 0x%02x, reason 0x%02x, nak data 0x%02x\n", txmsg->reply.req_type, txmsg->reply.u.nak.reason, txmsg->reply.u.nak.nak_data);
2352		}
2353
2354		memset(&mgr->down_rep_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2355		drm_dp_put_mst_branch_device(mstb);
2356
2357		mutex_lock(&mgr->qlock);
2358		txmsg->state = DRM_DP_SIDEBAND_TX_RX;
2359		mstb->tx_slots[slot] = NULL;
2360		mutex_unlock(&mgr->qlock);
2361
2362		wake_up_all(&mgr->tx_waitq);
2363	}
2364	return ret;
2365}
2366
2367static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr)
2368{
2369	int ret = 0;
2370
2371	if (!drm_dp_get_one_sb_msg(mgr, true)) {
2372		memset(&mgr->up_req_recv, 0,
2373		       sizeof(struct drm_dp_sideband_msg_rx));
2374		return 0;
2375	}
2376
2377	if (mgr->up_req_recv.have_eomt) {
2378		struct drm_dp_sideband_msg_req_body msg;
2379		struct drm_dp_mst_branch *mstb = NULL;
2380		bool seqno;
2381
2382		if (!mgr->up_req_recv.initial_hdr.broadcast) {
2383			mstb = drm_dp_get_mst_branch_device(mgr,
2384							    mgr->up_req_recv.initial_hdr.lct,
2385							    mgr->up_req_recv.initial_hdr.rad);
2386			if (!mstb) {
2387				DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2388				memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2389				return 0;
2390			}
2391		}
2392
2393		seqno = mgr->up_req_recv.initial_hdr.seqno;
2394		drm_dp_sideband_parse_req(&mgr->up_req_recv, &msg);
2395
2396		if (msg.req_type == DP_CONNECTION_STATUS_NOTIFY) {
2397			drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2398
2399			if (!mstb)
2400				mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.conn_stat.guid);
2401
2402			if (!mstb) {
2403				DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2404				memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2405				return 0;
2406			}
2407
2408			drm_dp_update_port(mstb, &msg.u.conn_stat);
2409
2410			DRM_DEBUG_KMS("Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", msg.u.conn_stat.port_number, msg.u.conn_stat.legacy_device_plug_status, msg.u.conn_stat.displayport_device_plug_status, msg.u.conn_stat.message_capability_status, msg.u.conn_stat.input_port, msg.u.conn_stat.peer_device_type);
2411			(*mgr->cbs->hotplug)(mgr);
2412
2413		} else if (msg.req_type == DP_RESOURCE_STATUS_NOTIFY) {
2414			drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, msg.req_type, seqno, false);
2415			if (!mstb)
2416				mstb = drm_dp_get_mst_branch_device_by_guid(mgr, msg.u.resource_stat.guid);
2417
2418			if (!mstb) {
2419				DRM_DEBUG_KMS("Got MST reply from unknown device %d\n", mgr->up_req_recv.initial_hdr.lct);
2420				memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2421				return 0;
2422			}
2423
2424			DRM_DEBUG_KMS("Got RSN: pn: %d avail_pbn %d\n", msg.u.resource_stat.port_number, msg.u.resource_stat.available_pbn);
2425		}
2426
2427		if (mstb)
2428			drm_dp_put_mst_branch_device(mstb);
2429
2430		memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx));
2431	}
2432	return ret;
2433}
2434
2435/**
2436 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify
2437 * @mgr: manager to notify irq for.
2438 * @esi: 4 bytes from SINK_COUNT_ESI
2439 * @handled: whether the hpd interrupt was consumed or not
2440 *
2441 * This should be called from the driver when it detects a short IRQ,
2442 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The
2443 * topology manager will process the sideband messages received as a result
2444 * of this.
2445 */
2446int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled)
2447{
2448	int ret = 0;
2449	int sc;
2450	*handled = false;
2451	sc = esi[0] & 0x3f;
2452
2453	if (sc != mgr->sink_count) {
2454		mgr->sink_count = sc;
2455		*handled = true;
2456	}
2457
2458	if (esi[1] & DP_DOWN_REP_MSG_RDY) {
2459		ret = drm_dp_mst_handle_down_rep(mgr);
2460		*handled = true;
2461	}
2462
2463	if (esi[1] & DP_UP_REQ_MSG_RDY) {
2464		ret |= drm_dp_mst_handle_up_req(mgr);
2465		*handled = true;
2466	}
2467
2468	drm_dp_mst_kick_tx(mgr);
2469	return ret;
2470}
2471EXPORT_SYMBOL(drm_dp_mst_hpd_irq);
2472
2473/**
2474 * drm_dp_mst_detect_port() - get connection status for an MST port
2475 * @connector: DRM connector for this port
2476 * @mgr: manager for this port
2477 * @port: unverified pointer to a port
2478 *
2479 * This returns the current connection state for a port. It validates the
2480 * port pointer still exists so the caller doesn't require a reference
2481 */
2482enum drm_connector_status drm_dp_mst_detect_port(struct drm_connector *connector,
2483						 struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2484{
2485	enum drm_connector_status status = connector_status_disconnected;
2486
2487	/* we need to search for the port in the mgr in case its gone */
2488	port = drm_dp_get_validated_port_ref(mgr, port);
2489	if (!port)
2490		return connector_status_disconnected;
2491
2492	if (!port->ddps)
2493		goto out;
2494
2495	switch (port->pdt) {
2496	case DP_PEER_DEVICE_NONE:
2497	case DP_PEER_DEVICE_MST_BRANCHING:
2498		break;
2499
2500	case DP_PEER_DEVICE_SST_SINK:
2501		status = connector_status_connected;
2502		/* for logical ports - cache the EDID */
2503		if (port->port_num >= 8 && !port->cached_edid) {
2504			port->cached_edid = drm_get_edid(connector, &port->aux.ddc);
2505		}
2506		break;
2507	case DP_PEER_DEVICE_DP_LEGACY_CONV:
2508		if (port->ldps)
2509			status = connector_status_connected;
2510		break;
2511	}
2512out:
2513	drm_dp_put_port(port);
2514	return status;
2515}
2516EXPORT_SYMBOL(drm_dp_mst_detect_port);
2517
2518/**
2519 * drm_dp_mst_port_has_audio() - Check whether port has audio capability or not
2520 * @mgr: manager for this port
2521 * @port: unverified pointer to a port.
2522 *
2523 * This returns whether the port supports audio or not.
2524 */
2525bool drm_dp_mst_port_has_audio(struct drm_dp_mst_topology_mgr *mgr,
2526					struct drm_dp_mst_port *port)
2527{
2528	bool ret = false;
2529
2530	port = drm_dp_get_validated_port_ref(mgr, port);
2531	if (!port)
2532		return ret;
2533	ret = port->has_audio;
2534	drm_dp_put_port(port);
2535	return ret;
2536}
2537EXPORT_SYMBOL(drm_dp_mst_port_has_audio);
2538
2539/**
2540 * drm_dp_mst_get_edid() - get EDID for an MST port
2541 * @connector: toplevel connector to get EDID for
2542 * @mgr: manager for this port
2543 * @port: unverified pointer to a port.
2544 *
2545 * This returns an EDID for the port connected to a connector,
2546 * It validates the pointer still exists so the caller doesn't require a
2547 * reference.
2548 */
2549struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2550{
2551	struct edid *edid = NULL;
2552
2553	/* we need to search for the port in the mgr in case its gone */
2554	port = drm_dp_get_validated_port_ref(mgr, port);
2555	if (!port)
2556		return NULL;
2557
2558	if (port->cached_edid)
2559		edid = drm_edid_duplicate(port->cached_edid);
2560	else {
2561		edid = drm_get_edid(connector, &port->aux.ddc);
2562		drm_mode_connector_set_tile_property(connector);
2563	}
2564	port->has_audio = drm_detect_monitor_audio(edid);
2565	drm_dp_put_port(port);
2566	return edid;
2567}
2568EXPORT_SYMBOL(drm_dp_mst_get_edid);
2569
2570/**
2571 * drm_dp_find_vcpi_slots() - find slots for this PBN value
2572 * @mgr: manager to use
2573 * @pbn: payload bandwidth to convert into slots.
2574 */
2575int drm_dp_find_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr,
2576			   int pbn)
2577{
2578	int num_slots;
2579
2580	num_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2581
2582	/* max. time slots - one slot for MTP header */
2583	if (num_slots > 63)
2584		return -ENOSPC;
2585	return num_slots;
2586}
2587EXPORT_SYMBOL(drm_dp_find_vcpi_slots);
2588
2589static int drm_dp_init_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2590			    struct drm_dp_vcpi *vcpi, int pbn, int slots)
2591{
2592	int ret;
2593
2594	/* max. time slots - one slot for MTP header */
2595	if (slots > 63)
2596		return -ENOSPC;
2597
2598	vcpi->pbn = pbn;
2599	vcpi->aligned_pbn = slots * mgr->pbn_div;
2600	vcpi->num_slots = slots;
2601
2602	ret = drm_dp_mst_assign_payload_id(mgr, vcpi);
2603	if (ret < 0)
2604		return ret;
2605	return 0;
2606}
2607
2608/**
2609 * drm_dp_atomic_find_vcpi_slots() - Find and add vcpi slots to the state
2610 * @state: global atomic state
2611 * @mgr: MST topology manager for the port
2612 * @port: port to find vcpi slots for
2613 * @pbn: bandwidth required for the mode in PBN
2614 *
2615 * RETURNS:
2616 * Total slots in the atomic state assigned for this port or error
2617 */
2618int drm_dp_atomic_find_vcpi_slots(struct drm_atomic_state *state,
2619				  struct drm_dp_mst_topology_mgr *mgr,
2620				  struct drm_dp_mst_port *port, int pbn)
2621{
2622	struct drm_dp_mst_topology_state *topology_state;
2623	int req_slots;
2624
2625	topology_state = drm_atomic_get_mst_topology_state(state, mgr);
2626	if (IS_ERR(topology_state))
2627		return PTR_ERR(topology_state);
2628
2629	port = drm_dp_get_validated_port_ref(mgr, port);
2630	if (port == NULL)
2631		return -EINVAL;
2632	req_slots = DIV_ROUND_UP(pbn, mgr->pbn_div);
2633	DRM_DEBUG_KMS("vcpi slots req=%d, avail=%d\n",
2634			req_slots, topology_state->avail_slots);
2635
2636	if (req_slots > topology_state->avail_slots) {
2637		drm_dp_put_port(port);
2638		return -ENOSPC;
2639	}
2640
2641	topology_state->avail_slots -= req_slots;
2642	DRM_DEBUG_KMS("vcpi slots avail=%d", topology_state->avail_slots);
2643
2644	drm_dp_put_port(port);
2645	return req_slots;
2646}
2647EXPORT_SYMBOL(drm_dp_atomic_find_vcpi_slots);
2648
2649/**
2650 * drm_dp_atomic_release_vcpi_slots() - Release allocated vcpi slots
2651 * @state: global atomic state
2652 * @mgr: MST topology manager for the port
2653 * @slots: number of vcpi slots to release
2654 *
2655 * RETURNS:
2656 * 0 if @slots were added back to &drm_dp_mst_topology_state->avail_slots or
2657 * negative error code
2658 */
2659int drm_dp_atomic_release_vcpi_slots(struct drm_atomic_state *state,
2660				     struct drm_dp_mst_topology_mgr *mgr,
2661				     int slots)
2662{
2663	struct drm_dp_mst_topology_state *topology_state;
2664
2665	topology_state = drm_atomic_get_mst_topology_state(state, mgr);
2666	if (IS_ERR(topology_state))
2667		return PTR_ERR(topology_state);
2668
2669	/* We cannot rely on port->vcpi.num_slots to update
2670	 * topology_state->avail_slots as the port may not exist if the parent
2671	 * branch device was unplugged. This should be fixed by tracking
2672	 * per-port slot allocation in drm_dp_mst_topology_state instead of
2673	 * depending on the caller to tell us how many slots to release.
2674	 */
2675	topology_state->avail_slots += slots;
2676	DRM_DEBUG_KMS("vcpi slots released=%d, avail=%d\n",
2677			slots, topology_state->avail_slots);
2678
2679	return 0;
2680}
2681EXPORT_SYMBOL(drm_dp_atomic_release_vcpi_slots);
2682
2683/**
2684 * drm_dp_mst_allocate_vcpi() - Allocate a virtual channel
2685 * @mgr: manager for this port
2686 * @port: port to allocate a virtual channel for.
2687 * @pbn: payload bandwidth number to request
2688 * @slots: returned number of slots for this PBN.
2689 */
2690bool drm_dp_mst_allocate_vcpi(struct drm_dp_mst_topology_mgr *mgr,
2691			      struct drm_dp_mst_port *port, int pbn, int slots)
2692{
2693	int ret;
2694
2695	port = drm_dp_get_validated_port_ref(mgr, port);
2696	if (!port)
2697		return false;
2698
2699	if (slots < 0)
2700		return false;
2701
2702	if (port->vcpi.vcpi > 0) {
2703		DRM_DEBUG_KMS("payload: vcpi %d already allocated for pbn %d - requested pbn %d\n", port->vcpi.vcpi, port->vcpi.pbn, pbn);
2704		if (pbn == port->vcpi.pbn) {
2705			drm_dp_put_port(port);
2706			return true;
2707		}
2708	}
2709
2710	ret = drm_dp_init_vcpi(mgr, &port->vcpi, pbn, slots);
2711	if (ret) {
2712		DRM_DEBUG_KMS("failed to init vcpi slots=%d max=63 ret=%d\n",
2713				DIV_ROUND_UP(pbn, mgr->pbn_div), ret);
2714		goto out;
2715	}
2716	DRM_DEBUG_KMS("initing vcpi for pbn=%d slots=%d\n",
2717			pbn, port->vcpi.num_slots);
2718
2719	drm_dp_put_port(port);
2720	return true;
2721out:
2722	return false;
2723}
2724EXPORT_SYMBOL(drm_dp_mst_allocate_vcpi);
2725
2726int drm_dp_mst_get_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2727{
2728	int slots = 0;
2729	port = drm_dp_get_validated_port_ref(mgr, port);
2730	if (!port)
2731		return slots;
2732
2733	slots = port->vcpi.num_slots;
2734	drm_dp_put_port(port);
2735	return slots;
2736}
2737EXPORT_SYMBOL(drm_dp_mst_get_vcpi_slots);
2738
2739/**
2740 * drm_dp_mst_reset_vcpi_slots() - Reset number of slots to 0 for VCPI
2741 * @mgr: manager for this port
2742 * @port: unverified pointer to a port.
2743 *
2744 * This just resets the number of slots for the ports VCPI for later programming.
2745 */
2746void drm_dp_mst_reset_vcpi_slots(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2747{
2748	port = drm_dp_get_validated_port_ref(mgr, port);
2749	if (!port)
2750		return;
2751	port->vcpi.num_slots = 0;
2752	drm_dp_put_port(port);
2753}
2754EXPORT_SYMBOL(drm_dp_mst_reset_vcpi_slots);
2755
2756/**
2757 * drm_dp_mst_deallocate_vcpi() - deallocate a VCPI
2758 * @mgr: manager for this port
2759 * @port: unverified port to deallocate vcpi for
2760 */
2761void drm_dp_mst_deallocate_vcpi(struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port)
2762{
2763	port = drm_dp_get_validated_port_ref(mgr, port);
2764	if (!port)
2765		return;
2766
2767	drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
2768	port->vcpi.num_slots = 0;
2769	port->vcpi.pbn = 0;
2770	port->vcpi.aligned_pbn = 0;
2771	port->vcpi.vcpi = 0;
2772	drm_dp_put_port(port);
2773}
2774EXPORT_SYMBOL(drm_dp_mst_deallocate_vcpi);
2775
2776static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr,
2777				     int id, struct drm_dp_payload *payload)
2778{
2779	u8 payload_alloc[3], status;
2780	int ret;
2781	int retries = 0;
2782
2783	drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS,
2784			   DP_PAYLOAD_TABLE_UPDATED);
2785
2786	payload_alloc[0] = id;
2787	payload_alloc[1] = payload->start_slot;
2788	payload_alloc[2] = payload->num_slots;
2789
2790	ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3);
2791	if (ret != 3) {
2792		DRM_DEBUG_KMS("failed to write payload allocation %d\n", ret);
2793		goto fail;
2794	}
2795
2796retry:
2797	ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2798	if (ret < 0) {
2799		DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2800		goto fail;
2801	}
2802
2803	if (!(status & DP_PAYLOAD_TABLE_UPDATED)) {
2804		retries++;
2805		if (retries < 20) {
2806			usleep_range(10000, 20000);
2807			goto retry;
2808		}
2809		DRM_DEBUG_KMS("status not set after read payload table status %d\n", status);
2810		ret = -EINVAL;
2811		goto fail;
2812	}
2813	ret = 0;
2814fail:
2815	return ret;
2816}
2817
2818
2819/**
2820 * drm_dp_check_act_status() - Check ACT handled status.
2821 * @mgr: manager to use
2822 *
2823 * Check the payload status bits in the DPCD for ACT handled completion.
2824 */
2825int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr)
2826{
2827	u8 status;
2828	int ret;
2829	int count = 0;
2830
2831	do {
2832		ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status);
2833
2834		if (ret < 0) {
2835			DRM_DEBUG_KMS("failed to read payload table status %d\n", ret);
2836			goto fail;
2837		}
2838
2839		if (status & DP_PAYLOAD_ACT_HANDLED)
2840			break;
2841		count++;
2842		udelay(100);
2843
2844	} while (count < 30);
2845
2846	if (!(status & DP_PAYLOAD_ACT_HANDLED)) {
2847		DRM_DEBUG_KMS("failed to get ACT bit %d after %d retries\n", status, count);
2848		ret = -EINVAL;
2849		goto fail;
2850	}
2851	return 0;
2852fail:
2853	return ret;
2854}
2855EXPORT_SYMBOL(drm_dp_check_act_status);
2856
2857/**
2858 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode.
2859 * @clock: dot clock for the mode
2860 * @bpp: bpp for the mode.
2861 *
2862 * This uses the formula in the spec to calculate the PBN value for a mode.
2863 */
2864int drm_dp_calc_pbn_mode(int clock, int bpp)
2865{
2866	u64 kbps;
2867	s64 peak_kbps;
2868	u32 numerator;
2869	u32 denominator;
2870
2871	kbps = clock * bpp;
2872
2873	/*
2874	 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006
2875	 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on
2876	 * common multiplier to render an integer PBN for all link rate/lane
2877	 * counts combinations
2878	 * calculate
2879	 * peak_kbps *= (1006/1000)
2880	 * peak_kbps *= (64/54)
2881	 * peak_kbps *= 8    convert to bytes
2882	 */
2883
2884	numerator = 64 * 1006;
2885	denominator = 54 * 8 * 1000 * 1000;
2886
2887	kbps *= numerator;
2888	peak_kbps = drm_fixp_from_fraction(kbps, denominator);
2889
2890	return drm_fixp2int_ceil(peak_kbps);
2891}
2892EXPORT_SYMBOL(drm_dp_calc_pbn_mode);
2893
2894static int test_calc_pbn_mode(void)
2895{
2896	int ret;
2897	ret = drm_dp_calc_pbn_mode(154000, 30);
2898	if (ret != 689) {
2899		DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2900				154000, 30, 689, ret);
2901		return -EINVAL;
2902	}
2903	ret = drm_dp_calc_pbn_mode(234000, 30);
2904	if (ret != 1047) {
2905		DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2906				234000, 30, 1047, ret);
2907		return -EINVAL;
2908	}
2909	ret = drm_dp_calc_pbn_mode(297000, 24);
2910	if (ret != 1063) {
2911		DRM_ERROR("PBN calculation test failed - clock %d, bpp %d, expected PBN %d, actual PBN %d.\n",
2912				297000, 24, 1063, ret);
2913		return -EINVAL;
2914	}
2915	return 0;
2916}
2917
2918/* we want to kick the TX after we've ack the up/down IRQs. */
2919static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr)
2920{
2921	queue_work(system_long_wq, &mgr->tx_work);
2922}
2923
2924static void drm_dp_mst_dump_mstb(struct seq_file *m,
2925				 struct drm_dp_mst_branch *mstb)
2926{
2927	struct drm_dp_mst_port *port;
2928	int tabs = mstb->lct;
2929	char prefix[10];
2930	int i;
2931
2932	for (i = 0; i < tabs; i++)
2933		prefix[i] = '\t';
2934	prefix[i] = '\0';
2935
2936	seq_printf(m, "%smst: %p, %d\n", prefix, mstb, mstb->num_ports);
2937	list_for_each_entry(port, &mstb->ports, next) {
2938		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);
2939		if (port->mstb)
2940			drm_dp_mst_dump_mstb(m, port->mstb);
2941	}
2942}
2943
2944static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr,
2945				  char *buf)
2946{
2947	int i;
2948
2949	for (i = 0; i < 64; i += 16) {
2950		if (drm_dp_dpcd_read(mgr->aux,
2951				     DP_PAYLOAD_TABLE_UPDATE_STATUS + i,
2952				     &buf[i], 16) != 16)
2953			return false;
2954	}
2955	return true;
2956}
2957
2958static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr,
2959			       struct drm_dp_mst_port *port, char *name,
2960			       int namelen)
2961{
2962	struct edid *mst_edid;
2963
2964	mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port);
2965	drm_edid_get_monitor_name(mst_edid, name, namelen);
2966}
2967
2968/**
2969 * drm_dp_mst_dump_topology(): dump topology to seq file.
2970 * @m: seq_file to dump output to
2971 * @mgr: manager to dump current topology for.
2972 *
2973 * helper to dump MST topology to a seq file for debugfs.
2974 */
2975void drm_dp_mst_dump_topology(struct seq_file *m,
2976			      struct drm_dp_mst_topology_mgr *mgr)
2977{
2978	int i;
2979	struct drm_dp_mst_port *port;
2980
2981	mutex_lock(&mgr->lock);
2982	if (mgr->mst_primary)
2983		drm_dp_mst_dump_mstb(m, mgr->mst_primary);
2984
2985	/* dump VCPIs */
2986	mutex_unlock(&mgr->lock);
2987
2988	mutex_lock(&mgr->payload_lock);
2989	seq_printf(m, "vcpi: %lx %lx %d\n", mgr->payload_mask, mgr->vcpi_mask,
2990		mgr->max_payloads);
2991
2992	for (i = 0; i < mgr->max_payloads; i++) {
2993		if (mgr->proposed_vcpis[i]) {
2994			char name[14];
2995
2996			port = container_of(mgr->proposed_vcpis[i], struct drm_dp_mst_port, vcpi);
2997			fetch_monitor_name(mgr, port, name, sizeof(name));
2998			seq_printf(m, "vcpi %d: %d %d %d sink name: %s\n", i,
2999				   port->port_num, port->vcpi.vcpi,
3000				   port->vcpi.num_slots,
3001				   (*name != 0) ? name :  "Unknown");
3002		} else
3003			seq_printf(m, "vcpi %d:unused\n", i);
3004	}
3005	for (i = 0; i < mgr->max_payloads; i++) {
3006		seq_printf(m, "payload %d: %d, %d, %d\n",
3007			   i,
3008			   mgr->payloads[i].payload_state,
3009			   mgr->payloads[i].start_slot,
3010			   mgr->payloads[i].num_slots);
3011
3012
3013	}
3014	mutex_unlock(&mgr->payload_lock);
3015
3016	mutex_lock(&mgr->lock);
3017	if (mgr->mst_primary) {
3018		u8 buf[64];
3019		int ret;
3020
3021		ret = drm_dp_dpcd_read(mgr->aux, DP_DPCD_REV, buf, DP_RECEIVER_CAP_SIZE);
3022		seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf);
3023		ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2);
3024		seq_printf(m, "faux/mst: %*ph\n", 2, buf);
3025		ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1);
3026		seq_printf(m, "mst ctrl: %*ph\n", 1, buf);
3027
3028		/* dump the standard OUI branch header */
3029		ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE);
3030		seq_printf(m, "branch oui: %*phN devid: ", 3, buf);
3031		for (i = 0x3; i < 0x8 && buf[i]; i++)
3032			seq_printf(m, "%c", buf[i]);
3033		seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n",
3034			   buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]);
3035		if (dump_dp_payload_table(mgr, buf))
3036			seq_printf(m, "payload table: %*ph\n", 63, buf);
3037
3038	}
3039
3040	mutex_unlock(&mgr->lock);
3041
3042}
3043EXPORT_SYMBOL(drm_dp_mst_dump_topology);
3044
3045static void drm_dp_tx_work(struct work_struct *work)
3046{
3047	struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work);
3048
3049	mutex_lock(&mgr->qlock);
3050	if (!list_empty(&mgr->tx_msg_downq))
3051		process_single_down_tx_qlock(mgr);
3052	mutex_unlock(&mgr->qlock);
3053}
3054
3055static void drm_dp_free_mst_port(struct kref *kref)
3056{
3057	struct drm_dp_mst_port *port = container_of(kref, struct drm_dp_mst_port, kref);
3058	kref_put(&port->parent->kref, drm_dp_free_mst_branch_device);
3059	kfree(port);
3060}
3061
3062static void drm_dp_destroy_connector_work(struct work_struct *work)
3063{
3064	struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, destroy_connector_work);
3065	struct drm_dp_mst_port *port;
3066	bool send_hotplug = false;
3067	/*
3068	 * Not a regular list traverse as we have to drop the destroy
3069	 * connector lock before destroying the connector, to avoid AB->BA
3070	 * ordering between this lock and the config mutex.
3071	 */
3072	for (;;) {
3073		mutex_lock(&mgr->destroy_connector_lock);
3074		port = list_first_entry_or_null(&mgr->destroy_connector_list, struct drm_dp_mst_port, next);
3075		if (!port) {
3076			mutex_unlock(&mgr->destroy_connector_lock);
3077			break;
3078		}
3079		list_del(&port->next);
3080		mutex_unlock(&mgr->destroy_connector_lock);
3081
3082		kref_init(&port->kref);
3083		INIT_LIST_HEAD(&port->next);
3084
3085		mgr->cbs->destroy_connector(mgr, port->connector);
3086
3087		drm_dp_port_teardown_pdt(port, port->pdt);
3088		port->pdt = DP_PEER_DEVICE_NONE;
3089
3090		if (!port->input && port->vcpi.vcpi > 0) {
3091			drm_dp_mst_reset_vcpi_slots(mgr, port);
3092			drm_dp_update_payload_part1(mgr);
3093			drm_dp_mst_put_payload_id(mgr, port->vcpi.vcpi);
3094		}
3095
3096		kref_put(&port->kref, drm_dp_free_mst_port);
3097		send_hotplug = true;
3098	}
3099	if (send_hotplug)
3100		(*mgr->cbs->hotplug)(mgr);
3101}
3102
3103static struct drm_private_state *
3104drm_dp_mst_duplicate_state(struct drm_private_obj *obj)
3105{
3106	struct drm_dp_mst_topology_state *state;
3107
3108	state = kmemdup(obj->state, sizeof(*state), GFP_KERNEL);
3109	if (!state)
3110		return NULL;
3111
3112	__drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
3113
3114	return &state->base;
3115}
3116
3117static void drm_dp_mst_destroy_state(struct drm_private_obj *obj,
3118				     struct drm_private_state *state)
3119{
3120	struct drm_dp_mst_topology_state *mst_state =
3121		to_dp_mst_topology_state(state);
3122
3123	kfree(mst_state);
3124}
3125
3126static const struct drm_private_state_funcs mst_state_funcs = {
3127	.atomic_duplicate_state = drm_dp_mst_duplicate_state,
3128	.atomic_destroy_state = drm_dp_mst_destroy_state,
3129};
3130
3131/**
3132 * drm_atomic_get_mst_topology_state: get MST topology state
3133 *
3134 * @state: global atomic state
3135 * @mgr: MST topology manager, also the private object in this case
3136 *
3137 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic
3138 * state vtable so that the private object state returned is that of a MST
3139 * topology object. Also, drm_atomic_get_private_obj_state() expects the caller
3140 * to care of the locking, so warn if don't hold the connection_mutex.
3141 *
3142 * RETURNS:
3143 *
3144 * The MST topology state or error pointer.
3145 */
3146struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state,
3147								    struct drm_dp_mst_topology_mgr *mgr)
3148{
3149	struct drm_device *dev = mgr->dev;
3150
3151	WARN_ON(!drm_modeset_is_locked(&dev->mode_config.connection_mutex));
3152	return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base));
3153}
3154EXPORT_SYMBOL(drm_atomic_get_mst_topology_state);
3155
3156/**
3157 * drm_dp_mst_topology_mgr_init - initialise a topology manager
3158 * @mgr: manager struct to initialise
3159 * @dev: device providing this structure - for i2c addition.
3160 * @aux: DP helper aux channel to talk to this device
3161 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit
3162 * @max_payloads: maximum number of payloads this GPU can source
3163 * @conn_base_id: the connector object ID the MST device is connected to.
3164 *
3165 * Return 0 for success, or negative error code on failure
3166 */
3167int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr,
3168				 struct drm_device *dev, struct drm_dp_aux *aux,
3169				 int max_dpcd_transaction_bytes,
3170				 int max_payloads, int conn_base_id)
3171{
3172	struct drm_dp_mst_topology_state *mst_state;
3173
3174	mutex_init(&mgr->lock);
3175	mutex_init(&mgr->qlock);
3176	mutex_init(&mgr->payload_lock);
3177	mutex_init(&mgr->destroy_connector_lock);
3178	INIT_LIST_HEAD(&mgr->tx_msg_downq);
3179	INIT_LIST_HEAD(&mgr->destroy_connector_list);
3180	INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work);
3181	INIT_WORK(&mgr->tx_work, drm_dp_tx_work);
3182	INIT_WORK(&mgr->destroy_connector_work, drm_dp_destroy_connector_work);
3183	init_waitqueue_head(&mgr->tx_waitq);
3184	mgr->dev = dev;
3185	mgr->aux = aux;
3186	mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes;
3187	mgr->max_payloads = max_payloads;
3188	mgr->conn_base_id = conn_base_id;
3189	if (max_payloads + 1 > sizeof(mgr->payload_mask) * 8 ||
3190	    max_payloads + 1 > sizeof(mgr->vcpi_mask) * 8)
3191		return -EINVAL;
3192	mgr->payloads = kcalloc(max_payloads, sizeof(struct drm_dp_payload), GFP_KERNEL);
3193	if (!mgr->payloads)
3194		return -ENOMEM;
3195	mgr->proposed_vcpis = kcalloc(max_payloads, sizeof(struct drm_dp_vcpi *), GFP_KERNEL);
3196	if (!mgr->proposed_vcpis)
3197		return -ENOMEM;
3198	set_bit(0, &mgr->payload_mask);
3199	if (test_calc_pbn_mode() < 0)
3200		DRM_ERROR("MST PBN self-test failed\n");
3201
3202	mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL);
3203	if (mst_state == NULL)
3204		return -ENOMEM;
3205
3206	mst_state->mgr = mgr;
3207
3208	/* max. time slots - one slot for MTP header */
3209	mst_state->avail_slots = 63;
3210
3211	drm_atomic_private_obj_init(&mgr->base,
3212				    &mst_state->base,
3213				    &mst_state_funcs);
3214
3215	return 0;
3216}
3217EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init);
3218
3219/**
3220 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager.
3221 * @mgr: manager to destroy
3222 */
3223void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr)
3224{
3225	flush_work(&mgr->work);
3226	flush_work(&mgr->destroy_connector_work);
3227	mutex_lock(&mgr->payload_lock);
3228	kfree(mgr->payloads);
3229	mgr->payloads = NULL;
3230	kfree(mgr->proposed_vcpis);
3231	mgr->proposed_vcpis = NULL;
3232	mutex_unlock(&mgr->payload_lock);
3233	mgr->dev = NULL;
3234	mgr->aux = NULL;
3235	drm_atomic_private_obj_fini(&mgr->base);
3236	mgr->funcs = NULL;
3237}
3238EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy);
3239
3240/* I2C device */
3241static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs,
3242			       int num)
3243{
3244	struct drm_dp_aux *aux = adapter->algo_data;
3245	struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, aux);
3246	struct drm_dp_mst_branch *mstb;
3247	struct drm_dp_mst_topology_mgr *mgr = port->mgr;
3248	unsigned int i;
3249	bool reading = false;
3250	struct drm_dp_sideband_msg_req_body msg;
3251	struct drm_dp_sideband_msg_tx *txmsg = NULL;
3252	int ret;
3253
3254	mstb = drm_dp_get_validated_mstb_ref(mgr, port->parent);
3255	if (!mstb)
3256		return -EREMOTEIO;
3257
3258	/* construct i2c msg */
3259	/* see if last msg is a read */
3260	if (msgs[num - 1].flags & I2C_M_RD)
3261		reading = true;
3262
3263	if (!reading || (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS)) {
3264		DRM_DEBUG_KMS("Unsupported I2C transaction for MST device\n");
3265		ret = -EIO;
3266		goto out;
3267	}
3268
3269	memset(&msg, 0, sizeof(msg));
3270	msg.req_type = DP_REMOTE_I2C_READ;
3271	msg.u.i2c_read.num_transactions = num - 1;
3272	msg.u.i2c_read.port_number = port->port_num;
3273	for (i = 0; i < num - 1; i++) {
3274		msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr;
3275		msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len;
3276		msg.u.i2c_read.transactions[i].bytes = msgs[i].buf;
3277	}
3278	msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr;
3279	msg.u.i2c_read.num_bytes_read = msgs[num - 1].len;
3280
3281	txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL);
3282	if (!txmsg) {
3283		ret = -ENOMEM;
3284		goto out;
3285	}
3286
3287	txmsg->dst = mstb;
3288	drm_dp_encode_sideband_req(&msg, txmsg);
3289
3290	drm_dp_queue_down_tx(mgr, txmsg);
3291
3292	ret = drm_dp_mst_wait_tx_reply(mstb, txmsg);
3293	if (ret > 0) {
3294
3295		if (txmsg->reply.reply_type == 1) { /* got a NAK back */
3296			ret = -EREMOTEIO;
3297			goto out;
3298		}
3299		if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) {
3300			ret = -EIO;
3301			goto out;
3302		}
3303		memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len);
3304		ret = num;
3305	}
3306out:
3307	kfree(txmsg);
3308	drm_dp_put_mst_branch_device(mstb);
3309	return ret;
3310}
3311
3312static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter)
3313{
3314	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
3315	       I2C_FUNC_SMBUS_READ_BLOCK_DATA |
3316	       I2C_FUNC_SMBUS_BLOCK_PROC_CALL |
3317	       I2C_FUNC_10BIT_ADDR;
3318}
3319
3320static const struct i2c_algorithm drm_dp_mst_i2c_algo = {
3321	.functionality = drm_dp_mst_i2c_functionality,
3322	.master_xfer = drm_dp_mst_i2c_xfer,
3323};
3324
3325/**
3326 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX
3327 * @aux: DisplayPort AUX channel
3328 *
3329 * Returns 0 on success or a negative error code on failure.
3330 */
3331static int drm_dp_mst_register_i2c_bus(struct drm_dp_aux *aux)
3332{
3333	aux->ddc.algo = &drm_dp_mst_i2c_algo;
3334	aux->ddc.algo_data = aux;
3335	aux->ddc.retries = 3;
3336
3337	aux->ddc.class = I2C_CLASS_DDC;
3338	aux->ddc.owner = THIS_MODULE;
3339	aux->ddc.dev.parent = aux->dev;
3340	aux->ddc.dev.of_node = aux->dev->of_node;
3341
3342	strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev),
3343		sizeof(aux->ddc.name));
3344
3345	return i2c_add_adapter(&aux->ddc);
3346}
3347
3348/**
3349 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter
3350 * @aux: DisplayPort AUX channel
3351 */
3352static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_aux *aux)
3353{
3354	i2c_del_adapter(&aux->ddc);
3355}