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drm_dp_mst_topology.c
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linux-6.19.14/drivers/gpu/drm/display/drm_dp_mst_topology.c
1/* 2 * Copyright © 2014 Red Hat 3 * 4 * Permission to use, copy, modify, distribute, and sell this software and its 5 * documentation for any purpose is hereby granted without fee, provided that 6 * the above copyright notice appear in all copies and that both that copyright 7 * notice and this permission notice appear in supporting documentation, and 8 * that the name of the copyright holders not be used in advertising or 9 * publicity pertaining to distribution of the software without specific, 10 * written prior permission. The copyright holders make no representations 11 * about the suitability of this software for any purpose. It is provided "as 12 * is" without express or implied warranty. 13 * 14 * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, 15 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO 16 * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR 17 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, 18 * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER 19 * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE 20 * OF THIS SOFTWARE. 21 */ 22 23#include <linux/bitfield.h> 24#include <linux/delay.h> 25#include <linux/errno.h> 26#include <linux/export.h> 27#include <linux/i2c.h> 28#include <linux/init.h> 29#include <linux/kernel.h> 30#include <linux/random.h> 31#include <linux/sched.h> 32#include <linux/seq_file.h> 33 34#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 35#include <linux/stacktrace.h> 36#include <linux/sort.h> 37#include <linux/timekeeping.h> 38#include <linux/math64.h> 39#endif 40 41#include <drm/display/drm_dp_mst_helper.h> 42#include <drm/drm_atomic.h> 43#include <drm/drm_atomic_helper.h> 44#include <drm/drm_drv.h> 45#include <drm/drm_edid.h> 46#include <drm/drm_fixed.h> 47#include <drm/drm_print.h> 48#include <drm/drm_probe_helper.h> 49 50#include "drm_dp_helper_internal.h" 51#include "drm_dp_mst_topology_internal.h" 52 53/** 54 * DOC: dp mst helper 55 * 56 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport 57 * protocol. The helpers contain a topology manager and bandwidth manager. 58 * The helpers encapsulate the sending and received of sideband msgs. 59 */ 60struct drm_dp_pending_up_req { 61 struct drm_dp_sideband_msg_hdr hdr; 62 struct drm_dp_sideband_msg_req_body msg; 63 struct list_head next; 64}; 65 66static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, 67 char *buf); 68 69static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port); 70 71static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, 72 struct drm_dp_mst_port *port, 73 int offset, int size, u8 *bytes); 74static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, 75 struct drm_dp_mst_port *port, 76 int offset, int size, u8 *bytes); 77 78static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 79 struct drm_dp_mst_branch *mstb); 80 81static void 82drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr, 83 struct drm_dp_mst_branch *mstb); 84 85static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, 86 struct drm_dp_mst_branch *mstb, 87 struct drm_dp_mst_port *port); 88static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, 89 guid_t *guid); 90 91static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port); 92static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port); 93static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr); 94 95static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port, 96 struct drm_dp_mst_branch *branch); 97 98#define DBG_PREFIX "[dp_mst]" 99 100#define DP_STR(x) [DP_ ## x] = #x 101 102static const char *drm_dp_mst_req_type_str(u8 req_type) 103{ 104 static const char * const req_type_str[] = { 105 DP_STR(GET_MSG_TRANSACTION_VERSION), 106 DP_STR(LINK_ADDRESS), 107 DP_STR(CONNECTION_STATUS_NOTIFY), 108 DP_STR(ENUM_PATH_RESOURCES), 109 DP_STR(ALLOCATE_PAYLOAD), 110 DP_STR(QUERY_PAYLOAD), 111 DP_STR(RESOURCE_STATUS_NOTIFY), 112 DP_STR(CLEAR_PAYLOAD_ID_TABLE), 113 DP_STR(REMOTE_DPCD_READ), 114 DP_STR(REMOTE_DPCD_WRITE), 115 DP_STR(REMOTE_I2C_READ), 116 DP_STR(REMOTE_I2C_WRITE), 117 DP_STR(POWER_UP_PHY), 118 DP_STR(POWER_DOWN_PHY), 119 DP_STR(SINK_EVENT_NOTIFY), 120 DP_STR(QUERY_STREAM_ENC_STATUS), 121 }; 122 123 if (req_type >= ARRAY_SIZE(req_type_str) || 124 !req_type_str[req_type]) 125 return "unknown"; 126 127 return req_type_str[req_type]; 128} 129 130#undef DP_STR 131#define DP_STR(x) [DP_NAK_ ## x] = #x 132 133static const char *drm_dp_mst_nak_reason_str(u8 nak_reason) 134{ 135 static const char * const nak_reason_str[] = { 136 DP_STR(WRITE_FAILURE), 137 DP_STR(INVALID_READ), 138 DP_STR(CRC_FAILURE), 139 DP_STR(BAD_PARAM), 140 DP_STR(DEFER), 141 DP_STR(LINK_FAILURE), 142 DP_STR(NO_RESOURCES), 143 DP_STR(DPCD_FAIL), 144 DP_STR(I2C_NAK), 145 DP_STR(ALLOCATE_FAIL), 146 }; 147 148 if (nak_reason >= ARRAY_SIZE(nak_reason_str) || 149 !nak_reason_str[nak_reason]) 150 return "unknown"; 151 152 return nak_reason_str[nak_reason]; 153} 154 155#undef DP_STR 156#define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x 157 158static const char *drm_dp_mst_sideband_tx_state_str(int state) 159{ 160 static const char * const sideband_reason_str[] = { 161 DP_STR(QUEUED), 162 DP_STR(START_SEND), 163 DP_STR(SENT), 164 DP_STR(RX), 165 DP_STR(TIMEOUT), 166 }; 167 168 if (state >= ARRAY_SIZE(sideband_reason_str) || 169 !sideband_reason_str[state]) 170 return "unknown"; 171 172 return sideband_reason_str[state]; 173} 174 175static inline u8 176drm_dp_mst_get_ufp_num_at_lct_from_rad(u8 lct, const u8 *rad) 177{ 178 int idx = (lct / 2) - 1; 179 int shift = (lct % 2) ? 0 : 4; 180 u8 ufp_num; 181 182 /* mst_primary, it's rad is unset*/ 183 if (lct == 1) 184 return 0; 185 186 ufp_num = (rad[idx] >> shift) & 0xf; 187 188 return ufp_num; 189} 190 191static int 192drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len) 193{ 194 int i; 195 u8 unpacked_rad[16] = {}; 196 197 for (i = 0; i < lct; i++) 198 unpacked_rad[i] = drm_dp_mst_get_ufp_num_at_lct_from_rad(i + 1, rad); 199 200 /* TODO: Eventually add something to printk so we can format the rad 201 * like this: 1.2.3 202 */ 203 return snprintf(out, len, "%*phC", lct, unpacked_rad); 204} 205 206/* sideband msg handling */ 207static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles) 208{ 209 u8 bitmask = 0x80; 210 u8 bitshift = 7; 211 u8 array_index = 0; 212 int number_of_bits = num_nibbles * 4; 213 u8 remainder = 0; 214 215 while (number_of_bits != 0) { 216 number_of_bits--; 217 remainder <<= 1; 218 remainder |= (data[array_index] & bitmask) >> bitshift; 219 bitmask >>= 1; 220 bitshift--; 221 if (bitmask == 0) { 222 bitmask = 0x80; 223 bitshift = 7; 224 array_index++; 225 } 226 if ((remainder & 0x10) == 0x10) 227 remainder ^= 0x13; 228 } 229 230 number_of_bits = 4; 231 while (number_of_bits != 0) { 232 number_of_bits--; 233 remainder <<= 1; 234 if ((remainder & 0x10) != 0) 235 remainder ^= 0x13; 236 } 237 238 return remainder; 239} 240 241static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes) 242{ 243 u8 bitmask = 0x80; 244 u8 bitshift = 7; 245 u8 array_index = 0; 246 int number_of_bits = number_of_bytes * 8; 247 u16 remainder = 0; 248 249 while (number_of_bits != 0) { 250 number_of_bits--; 251 remainder <<= 1; 252 remainder |= (data[array_index] & bitmask) >> bitshift; 253 bitmask >>= 1; 254 bitshift--; 255 if (bitmask == 0) { 256 bitmask = 0x80; 257 bitshift = 7; 258 array_index++; 259 } 260 if ((remainder & 0x100) == 0x100) 261 remainder ^= 0xd5; 262 } 263 264 number_of_bits = 8; 265 while (number_of_bits != 0) { 266 number_of_bits--; 267 remainder <<= 1; 268 if ((remainder & 0x100) != 0) 269 remainder ^= 0xd5; 270 } 271 272 return remainder & 0xff; 273} 274static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr) 275{ 276 u8 size = 3; 277 278 size += (hdr->lct / 2); 279 return size; 280} 281 282static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr, 283 u8 *buf, int *len) 284{ 285 int idx = 0; 286 int i; 287 u8 crc4; 288 289 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf); 290 for (i = 0; i < (hdr->lct / 2); i++) 291 buf[idx++] = hdr->rad[i]; 292 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) | 293 (hdr->msg_len & 0x3f); 294 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4); 295 296 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1); 297 buf[idx - 1] |= (crc4 & 0xf); 298 299 *len = idx; 300} 301 302static bool drm_dp_decode_sideband_msg_hdr(const struct drm_dp_mst_topology_mgr *mgr, 303 struct drm_dp_sideband_msg_hdr *hdr, 304 u8 *buf, int buflen, u8 *hdrlen) 305{ 306 u8 crc4; 307 u8 len; 308 int i; 309 u8 idx; 310 311 if (buf[0] == 0) 312 return false; 313 len = 3; 314 len += ((buf[0] & 0xf0) >> 4) / 2; 315 if (len > buflen) 316 return false; 317 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1); 318 319 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) { 320 drm_dbg_kms(mgr->dev, "crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]); 321 return false; 322 } 323 324 hdr->lct = (buf[0] & 0xf0) >> 4; 325 hdr->lcr = (buf[0] & 0xf); 326 idx = 1; 327 for (i = 0; i < (hdr->lct / 2); i++) 328 hdr->rad[i] = buf[idx++]; 329 hdr->broadcast = (buf[idx] >> 7) & 0x1; 330 hdr->path_msg = (buf[idx] >> 6) & 0x1; 331 hdr->msg_len = buf[idx] & 0x3f; 332 if (hdr->msg_len < 1) /* min space for body CRC */ 333 return false; 334 335 idx++; 336 hdr->somt = (buf[idx] >> 7) & 0x1; 337 hdr->eomt = (buf[idx] >> 6) & 0x1; 338 hdr->seqno = (buf[idx] >> 4) & 0x1; 339 idx++; 340 *hdrlen = idx; 341 return true; 342} 343 344void 345drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req, 346 struct drm_dp_sideband_msg_tx *raw) 347{ 348 int idx = 0; 349 int i; 350 u8 *buf = raw->msg; 351 352 buf[idx++] = req->req_type & 0x7f; 353 354 switch (req->req_type) { 355 case DP_ENUM_PATH_RESOURCES: 356 case DP_POWER_DOWN_PHY: 357 case DP_POWER_UP_PHY: 358 buf[idx] = (req->u.port_num.port_number & 0xf) << 4; 359 idx++; 360 break; 361 case DP_ALLOCATE_PAYLOAD: 362 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 | 363 (req->u.allocate_payload.number_sdp_streams & 0xf); 364 idx++; 365 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f); 366 idx++; 367 buf[idx] = (req->u.allocate_payload.pbn >> 8); 368 idx++; 369 buf[idx] = (req->u.allocate_payload.pbn & 0xff); 370 idx++; 371 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) { 372 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) | 373 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf); 374 idx++; 375 } 376 if (req->u.allocate_payload.number_sdp_streams & 1) { 377 i = req->u.allocate_payload.number_sdp_streams - 1; 378 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4; 379 idx++; 380 } 381 break; 382 case DP_QUERY_PAYLOAD: 383 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4; 384 idx++; 385 buf[idx] = (req->u.query_payload.vcpi & 0x7f); 386 idx++; 387 break; 388 case DP_REMOTE_DPCD_READ: 389 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4; 390 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf; 391 idx++; 392 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8; 393 idx++; 394 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff); 395 idx++; 396 buf[idx] = (req->u.dpcd_read.num_bytes); 397 idx++; 398 break; 399 400 case DP_REMOTE_DPCD_WRITE: 401 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4; 402 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf; 403 idx++; 404 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8; 405 idx++; 406 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff); 407 idx++; 408 buf[idx] = (req->u.dpcd_write.num_bytes); 409 idx++; 410 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes); 411 idx += req->u.dpcd_write.num_bytes; 412 break; 413 case DP_REMOTE_I2C_READ: 414 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4; 415 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3); 416 idx++; 417 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) { 418 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f; 419 idx++; 420 buf[idx] = req->u.i2c_read.transactions[i].num_bytes; 421 idx++; 422 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes); 423 idx += req->u.i2c_read.transactions[i].num_bytes; 424 425 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4; 426 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf); 427 idx++; 428 } 429 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f; 430 idx++; 431 buf[idx] = (req->u.i2c_read.num_bytes_read); 432 idx++; 433 break; 434 435 case DP_REMOTE_I2C_WRITE: 436 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4; 437 idx++; 438 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f; 439 idx++; 440 buf[idx] = (req->u.i2c_write.num_bytes); 441 idx++; 442 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes); 443 idx += req->u.i2c_write.num_bytes; 444 break; 445 case DP_QUERY_STREAM_ENC_STATUS: { 446 const struct drm_dp_query_stream_enc_status *msg; 447 448 msg = &req->u.enc_status; 449 buf[idx] = msg->stream_id; 450 idx++; 451 memcpy(&buf[idx], msg->client_id, sizeof(msg->client_id)); 452 idx += sizeof(msg->client_id); 453 buf[idx] = 0; 454 buf[idx] |= FIELD_PREP(GENMASK(1, 0), msg->stream_event); 455 buf[idx] |= msg->valid_stream_event ? BIT(2) : 0; 456 buf[idx] |= FIELD_PREP(GENMASK(4, 3), msg->stream_behavior); 457 buf[idx] |= msg->valid_stream_behavior ? BIT(5) : 0; 458 idx++; 459 } 460 break; 461 } 462 raw->cur_len = idx; 463} 464EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req); 465 466/* Decode a sideband request we've encoded, mainly used for debugging */ 467int 468drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw, 469 struct drm_dp_sideband_msg_req_body *req) 470{ 471 const u8 *buf = raw->msg; 472 int i, idx = 0; 473 474 req->req_type = buf[idx++] & 0x7f; 475 switch (req->req_type) { 476 case DP_ENUM_PATH_RESOURCES: 477 case DP_POWER_DOWN_PHY: 478 case DP_POWER_UP_PHY: 479 req->u.port_num.port_number = (buf[idx] >> 4) & 0xf; 480 break; 481 case DP_ALLOCATE_PAYLOAD: 482 { 483 struct drm_dp_allocate_payload *a = 484 &req->u.allocate_payload; 485 486 a->number_sdp_streams = buf[idx] & 0xf; 487 a->port_number = (buf[idx] >> 4) & 0xf; 488 489 WARN_ON(buf[++idx] & 0x80); 490 a->vcpi = buf[idx] & 0x7f; 491 492 a->pbn = buf[++idx] << 8; 493 a->pbn |= buf[++idx]; 494 495 idx++; 496 for (i = 0; i < a->number_sdp_streams; i++) { 497 a->sdp_stream_sink[i] = 498 (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf; 499 } 500 } 501 break; 502 case DP_QUERY_PAYLOAD: 503 req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf; 504 WARN_ON(buf[++idx] & 0x80); 505 req->u.query_payload.vcpi = buf[idx] & 0x7f; 506 break; 507 case DP_REMOTE_DPCD_READ: 508 { 509 struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read; 510 511 r->port_number = (buf[idx] >> 4) & 0xf; 512 513 r->dpcd_address = (buf[idx] << 16) & 0xf0000; 514 r->dpcd_address |= (buf[++idx] << 8) & 0xff00; 515 r->dpcd_address |= buf[++idx] & 0xff; 516 517 r->num_bytes = buf[++idx]; 518 } 519 break; 520 case DP_REMOTE_DPCD_WRITE: 521 { 522 struct drm_dp_remote_dpcd_write *w = 523 &req->u.dpcd_write; 524 525 w->port_number = (buf[idx] >> 4) & 0xf; 526 527 w->dpcd_address = (buf[idx] << 16) & 0xf0000; 528 w->dpcd_address |= (buf[++idx] << 8) & 0xff00; 529 w->dpcd_address |= buf[++idx] & 0xff; 530 531 w->num_bytes = buf[++idx]; 532 533 w->bytes = kmemdup(&buf[++idx], w->num_bytes, 534 GFP_KERNEL); 535 if (!w->bytes) 536 return -ENOMEM; 537 } 538 break; 539 case DP_REMOTE_I2C_READ: 540 { 541 struct drm_dp_remote_i2c_read *r = &req->u.i2c_read; 542 struct drm_dp_remote_i2c_read_tx *tx; 543 bool failed = false; 544 545 r->num_transactions = buf[idx] & 0x3; 546 r->port_number = (buf[idx] >> 4) & 0xf; 547 for (i = 0; i < r->num_transactions; i++) { 548 tx = &r->transactions[i]; 549 550 tx->i2c_dev_id = buf[++idx] & 0x7f; 551 tx->num_bytes = buf[++idx]; 552 tx->bytes = kmemdup(&buf[++idx], 553 tx->num_bytes, 554 GFP_KERNEL); 555 if (!tx->bytes) { 556 failed = true; 557 break; 558 } 559 idx += tx->num_bytes; 560 tx->no_stop_bit = (buf[idx] >> 5) & 0x1; 561 tx->i2c_transaction_delay = buf[idx] & 0xf; 562 } 563 564 if (failed) { 565 for (i = 0; i < r->num_transactions; i++) { 566 tx = &r->transactions[i]; 567 kfree(tx->bytes); 568 } 569 return -ENOMEM; 570 } 571 572 r->read_i2c_device_id = buf[++idx] & 0x7f; 573 r->num_bytes_read = buf[++idx]; 574 } 575 break; 576 case DP_REMOTE_I2C_WRITE: 577 { 578 struct drm_dp_remote_i2c_write *w = &req->u.i2c_write; 579 580 w->port_number = (buf[idx] >> 4) & 0xf; 581 w->write_i2c_device_id = buf[++idx] & 0x7f; 582 w->num_bytes = buf[++idx]; 583 w->bytes = kmemdup(&buf[++idx], w->num_bytes, 584 GFP_KERNEL); 585 if (!w->bytes) 586 return -ENOMEM; 587 } 588 break; 589 case DP_QUERY_STREAM_ENC_STATUS: 590 req->u.enc_status.stream_id = buf[idx++]; 591 for (i = 0; i < sizeof(req->u.enc_status.client_id); i++) 592 req->u.enc_status.client_id[i] = buf[idx++]; 593 594 req->u.enc_status.stream_event = FIELD_GET(GENMASK(1, 0), 595 buf[idx]); 596 req->u.enc_status.valid_stream_event = FIELD_GET(BIT(2), 597 buf[idx]); 598 req->u.enc_status.stream_behavior = FIELD_GET(GENMASK(4, 3), 599 buf[idx]); 600 req->u.enc_status.valid_stream_behavior = FIELD_GET(BIT(5), 601 buf[idx]); 602 break; 603 } 604 605 return 0; 606} 607EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req); 608 609void 610drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req, 611 int indent, struct drm_printer *printer) 612{ 613 int i; 614 615#define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__) 616 if (req->req_type == DP_LINK_ADDRESS) { 617 /* No contents to print */ 618 P("type=%s\n", drm_dp_mst_req_type_str(req->req_type)); 619 return; 620 } 621 622 P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type)); 623 indent++; 624 625 switch (req->req_type) { 626 case DP_ENUM_PATH_RESOURCES: 627 case DP_POWER_DOWN_PHY: 628 case DP_POWER_UP_PHY: 629 P("port=%d\n", req->u.port_num.port_number); 630 break; 631 case DP_ALLOCATE_PAYLOAD: 632 P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n", 633 req->u.allocate_payload.port_number, 634 req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn, 635 req->u.allocate_payload.number_sdp_streams, 636 req->u.allocate_payload.number_sdp_streams, 637 req->u.allocate_payload.sdp_stream_sink); 638 break; 639 case DP_QUERY_PAYLOAD: 640 P("port=%d vcpi=%d\n", 641 req->u.query_payload.port_number, 642 req->u.query_payload.vcpi); 643 break; 644 case DP_REMOTE_DPCD_READ: 645 P("port=%d dpcd_addr=%05x len=%d\n", 646 req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address, 647 req->u.dpcd_read.num_bytes); 648 break; 649 case DP_REMOTE_DPCD_WRITE: 650 P("port=%d addr=%05x len=%d: %*ph\n", 651 req->u.dpcd_write.port_number, 652 req->u.dpcd_write.dpcd_address, 653 req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes, 654 req->u.dpcd_write.bytes); 655 break; 656 case DP_REMOTE_I2C_READ: 657 P("port=%d num_tx=%d id=%d size=%d:\n", 658 req->u.i2c_read.port_number, 659 req->u.i2c_read.num_transactions, 660 req->u.i2c_read.read_i2c_device_id, 661 req->u.i2c_read.num_bytes_read); 662 663 indent++; 664 for (i = 0; i < req->u.i2c_read.num_transactions; i++) { 665 const struct drm_dp_remote_i2c_read_tx *rtx = 666 &req->u.i2c_read.transactions[i]; 667 668 P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n", 669 i, rtx->i2c_dev_id, rtx->num_bytes, 670 rtx->no_stop_bit, rtx->i2c_transaction_delay, 671 rtx->num_bytes, rtx->bytes); 672 } 673 break; 674 case DP_REMOTE_I2C_WRITE: 675 P("port=%d id=%d size=%d: %*ph\n", 676 req->u.i2c_write.port_number, 677 req->u.i2c_write.write_i2c_device_id, 678 req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes, 679 req->u.i2c_write.bytes); 680 break; 681 case DP_QUERY_STREAM_ENC_STATUS: 682 P("stream_id=%u client_id=%*ph stream_event=%x " 683 "valid_event=%d stream_behavior=%x valid_behavior=%d", 684 req->u.enc_status.stream_id, 685 (int)ARRAY_SIZE(req->u.enc_status.client_id), 686 req->u.enc_status.client_id, req->u.enc_status.stream_event, 687 req->u.enc_status.valid_stream_event, 688 req->u.enc_status.stream_behavior, 689 req->u.enc_status.valid_stream_behavior); 690 break; 691 default: 692 P("???\n"); 693 break; 694 } 695#undef P 696} 697EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body); 698 699static inline void 700drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p, 701 const struct drm_dp_sideband_msg_tx *txmsg) 702{ 703 struct drm_dp_sideband_msg_req_body req; 704 char buf[64]; 705 int ret; 706 int i; 707 708 drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf, 709 sizeof(buf)); 710 drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n", 711 txmsg->cur_offset, txmsg->cur_len, txmsg->seqno, 712 drm_dp_mst_sideband_tx_state_str(txmsg->state), 713 txmsg->path_msg, buf); 714 715 ret = drm_dp_decode_sideband_req(txmsg, &req); 716 if (ret) { 717 drm_printf(p, "<failed to decode sideband req: %d>\n", ret); 718 return; 719 } 720 drm_dp_dump_sideband_msg_req_body(&req, 1, p); 721 722 switch (req.req_type) { 723 case DP_REMOTE_DPCD_WRITE: 724 kfree(req.u.dpcd_write.bytes); 725 break; 726 case DP_REMOTE_I2C_READ: 727 for (i = 0; i < req.u.i2c_read.num_transactions; i++) 728 kfree(req.u.i2c_read.transactions[i].bytes); 729 break; 730 case DP_REMOTE_I2C_WRITE: 731 kfree(req.u.i2c_write.bytes); 732 break; 733 } 734} 735 736static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len) 737{ 738 u8 crc4; 739 740 crc4 = drm_dp_msg_data_crc4(msg, len); 741 msg[len] = crc4; 742} 743 744static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep, 745 struct drm_dp_sideband_msg_tx *raw) 746{ 747 int idx = 0; 748 u8 *buf = raw->msg; 749 750 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f); 751 752 raw->cur_len = idx; 753} 754 755static int drm_dp_sideband_msg_set_header(struct drm_dp_sideband_msg_rx *msg, 756 struct drm_dp_sideband_msg_hdr *hdr, 757 u8 hdrlen) 758{ 759 /* 760 * ignore out-of-order messages or messages that are part of a 761 * failed transaction 762 */ 763 if (!hdr->somt && !msg->have_somt) 764 return false; 765 766 /* get length contained in this portion */ 767 msg->curchunk_idx = 0; 768 msg->curchunk_len = hdr->msg_len; 769 msg->curchunk_hdrlen = hdrlen; 770 771 /* we have already gotten an somt - don't bother parsing */ 772 if (hdr->somt && msg->have_somt) 773 return false; 774 775 if (hdr->somt) { 776 memcpy(&msg->initial_hdr, hdr, 777 sizeof(struct drm_dp_sideband_msg_hdr)); 778 msg->have_somt = true; 779 } 780 if (hdr->eomt) 781 msg->have_eomt = true; 782 783 return true; 784} 785 786/* this adds a chunk of msg to the builder to get the final msg */ 787static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx *msg, 788 u8 *replybuf, u8 replybuflen) 789{ 790 u8 crc4; 791 792 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen); 793 msg->curchunk_idx += replybuflen; 794 795 if (msg->curchunk_idx >= msg->curchunk_len) { 796 /* do CRC */ 797 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1); 798 if (crc4 != msg->chunk[msg->curchunk_len - 1]) 799 print_hex_dump(KERN_DEBUG, "wrong crc", 800 DUMP_PREFIX_NONE, 16, 1, 801 msg->chunk, msg->curchunk_len, false); 802 /* copy chunk into bigger msg */ 803 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1); 804 msg->curlen += msg->curchunk_len - 1; 805 } 806 return true; 807} 808 809static bool drm_dp_sideband_parse_link_address(const struct drm_dp_mst_topology_mgr *mgr, 810 struct drm_dp_sideband_msg_rx *raw, 811 struct drm_dp_sideband_msg_reply_body *repmsg) 812{ 813 int idx = 1; 814 int i; 815 816 import_guid(&repmsg->u.link_addr.guid, &raw->msg[idx]); 817 idx += 16; 818 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf; 819 idx++; 820 if (idx > raw->curlen) 821 goto fail_len; 822 for (i = 0; i < repmsg->u.link_addr.nports; i++) { 823 if (raw->msg[idx] & 0x80) 824 repmsg->u.link_addr.ports[i].input_port = 1; 825 826 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7; 827 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf); 828 829 idx++; 830 if (idx > raw->curlen) 831 goto fail_len; 832 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1; 833 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1; 834 if (repmsg->u.link_addr.ports[i].input_port == 0) 835 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1; 836 idx++; 837 if (idx > raw->curlen) 838 goto fail_len; 839 if (repmsg->u.link_addr.ports[i].input_port == 0) { 840 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]); 841 idx++; 842 if (idx > raw->curlen) 843 goto fail_len; 844 import_guid(&repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx]); 845 idx += 16; 846 if (idx > raw->curlen) 847 goto fail_len; 848 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf; 849 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf); 850 idx++; 851 852 } 853 if (idx > raw->curlen) 854 goto fail_len; 855 } 856 857 return true; 858fail_len: 859 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); 860 return false; 861} 862 863static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw, 864 struct drm_dp_sideband_msg_reply_body *repmsg) 865{ 866 int idx = 1; 867 868 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf; 869 idx++; 870 if (idx > raw->curlen) 871 goto fail_len; 872 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx]; 873 idx++; 874 if (idx > raw->curlen) 875 goto fail_len; 876 877 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes); 878 return true; 879fail_len: 880 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); 881 return false; 882} 883 884static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw, 885 struct drm_dp_sideband_msg_reply_body *repmsg) 886{ 887 int idx = 1; 888 889 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf; 890 idx++; 891 if (idx > raw->curlen) 892 goto fail_len; 893 return true; 894fail_len: 895 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen); 896 return false; 897} 898 899static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw, 900 struct drm_dp_sideband_msg_reply_body *repmsg) 901{ 902 int idx = 1; 903 904 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf); 905 idx++; 906 if (idx > raw->curlen) 907 goto fail_len; 908 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx]; 909 idx++; 910 /* TODO check */ 911 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes); 912 return true; 913fail_len: 914 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen); 915 return false; 916} 917 918static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw, 919 struct drm_dp_sideband_msg_reply_body *repmsg) 920{ 921 int idx = 1; 922 923 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf; 924 repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1; 925 idx++; 926 if (idx > raw->curlen) 927 goto fail_len; 928 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 929 idx += 2; 930 if (idx > raw->curlen) 931 goto fail_len; 932 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 933 idx += 2; 934 if (idx > raw->curlen) 935 goto fail_len; 936 return true; 937fail_len: 938 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen); 939 return false; 940} 941 942static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw, 943 struct drm_dp_sideband_msg_reply_body *repmsg) 944{ 945 int idx = 1; 946 947 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf; 948 idx++; 949 if (idx > raw->curlen) 950 goto fail_len; 951 repmsg->u.allocate_payload.vcpi = raw->msg[idx]; 952 idx++; 953 if (idx > raw->curlen) 954 goto fail_len; 955 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 956 idx += 2; 957 if (idx > raw->curlen) 958 goto fail_len; 959 return true; 960fail_len: 961 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen); 962 return false; 963} 964 965static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw, 966 struct drm_dp_sideband_msg_reply_body *repmsg) 967{ 968 int idx = 1; 969 970 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf; 971 idx++; 972 if (idx > raw->curlen) 973 goto fail_len; 974 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); 975 idx += 2; 976 if (idx > raw->curlen) 977 goto fail_len; 978 return true; 979fail_len: 980 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen); 981 return false; 982} 983 984static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw, 985 struct drm_dp_sideband_msg_reply_body *repmsg) 986{ 987 int idx = 1; 988 989 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf; 990 idx++; 991 if (idx > raw->curlen) { 992 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n", 993 idx, raw->curlen); 994 return false; 995 } 996 return true; 997} 998 999static bool 1000drm_dp_sideband_parse_query_stream_enc_status( 1001 struct drm_dp_sideband_msg_rx *raw, 1002 struct drm_dp_sideband_msg_reply_body *repmsg) 1003{ 1004 struct drm_dp_query_stream_enc_status_ack_reply *reply; 1005 1006 reply = &repmsg->u.enc_status; 1007 1008 reply->stream_id = raw->msg[3]; 1009 1010 reply->reply_signed = raw->msg[2] & BIT(0); 1011 1012 /* 1013 * NOTE: It's my impression from reading the spec that the below parsing 1014 * is correct. However I noticed while testing with an HDCP 1.4 display 1015 * through an HDCP 2.2 hub that only bit 3 was set. In that case, I 1016 * would expect both bits to be set. So keep the parsing following the 1017 * spec, but beware reality might not match the spec (at least for some 1018 * configurations). 1019 */ 1020 reply->hdcp_1x_device_present = raw->msg[2] & BIT(4); 1021 reply->hdcp_2x_device_present = raw->msg[2] & BIT(3); 1022 1023 reply->query_capable_device_present = raw->msg[2] & BIT(5); 1024 reply->legacy_device_present = raw->msg[2] & BIT(6); 1025 reply->unauthorizable_device_present = raw->msg[2] & BIT(7); 1026 1027 reply->auth_completed = !!(raw->msg[1] & BIT(3)); 1028 reply->encryption_enabled = !!(raw->msg[1] & BIT(4)); 1029 reply->repeater_present = !!(raw->msg[1] & BIT(5)); 1030 reply->state = (raw->msg[1] & GENMASK(7, 6)) >> 6; 1031 1032 return true; 1033} 1034 1035static bool drm_dp_sideband_parse_reply(const struct drm_dp_mst_topology_mgr *mgr, 1036 struct drm_dp_sideband_msg_rx *raw, 1037 struct drm_dp_sideband_msg_reply_body *msg) 1038{ 1039 memset(msg, 0, sizeof(*msg)); 1040 msg->reply_type = (raw->msg[0] & 0x80) >> 7; 1041 msg->req_type = (raw->msg[0] & 0x7f); 1042 1043 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) { 1044 import_guid(&msg->u.nak.guid, &raw->msg[1]); 1045 msg->u.nak.reason = raw->msg[17]; 1046 msg->u.nak.nak_data = raw->msg[18]; 1047 return false; 1048 } 1049 1050 switch (msg->req_type) { 1051 case DP_LINK_ADDRESS: 1052 return drm_dp_sideband_parse_link_address(mgr, raw, msg); 1053 case DP_QUERY_PAYLOAD: 1054 return drm_dp_sideband_parse_query_payload_ack(raw, msg); 1055 case DP_REMOTE_DPCD_READ: 1056 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg); 1057 case DP_REMOTE_DPCD_WRITE: 1058 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg); 1059 case DP_REMOTE_I2C_READ: 1060 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg); 1061 case DP_REMOTE_I2C_WRITE: 1062 return true; /* since there's nothing to parse */ 1063 case DP_ENUM_PATH_RESOURCES: 1064 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg); 1065 case DP_ALLOCATE_PAYLOAD: 1066 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg); 1067 case DP_POWER_DOWN_PHY: 1068 case DP_POWER_UP_PHY: 1069 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg); 1070 case DP_CLEAR_PAYLOAD_ID_TABLE: 1071 return true; /* since there's nothing to parse */ 1072 case DP_QUERY_STREAM_ENC_STATUS: 1073 return drm_dp_sideband_parse_query_stream_enc_status(raw, msg); 1074 default: 1075 drm_err(mgr->dev, "Got unknown reply 0x%02x (%s)\n", 1076 msg->req_type, drm_dp_mst_req_type_str(msg->req_type)); 1077 return false; 1078 } 1079} 1080 1081static bool 1082drm_dp_sideband_parse_connection_status_notify(const struct drm_dp_mst_topology_mgr *mgr, 1083 struct drm_dp_sideband_msg_rx *raw, 1084 struct drm_dp_sideband_msg_req_body *msg) 1085{ 1086 int idx = 1; 1087 1088 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; 1089 idx++; 1090 if (idx > raw->curlen) 1091 goto fail_len; 1092 1093 import_guid(&msg->u.conn_stat.guid, &raw->msg[idx]); 1094 idx += 16; 1095 if (idx > raw->curlen) 1096 goto fail_len; 1097 1098 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1; 1099 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1; 1100 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1; 1101 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1; 1102 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7); 1103 idx++; 1104 return true; 1105fail_len: 1106 drm_dbg_kms(mgr->dev, "connection status reply parse length fail %d %d\n", 1107 idx, raw->curlen); 1108 return false; 1109} 1110 1111static bool drm_dp_sideband_parse_resource_status_notify(const struct drm_dp_mst_topology_mgr *mgr, 1112 struct drm_dp_sideband_msg_rx *raw, 1113 struct drm_dp_sideband_msg_req_body *msg) 1114{ 1115 int idx = 1; 1116 1117 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; 1118 idx++; 1119 if (idx > raw->curlen) 1120 goto fail_len; 1121 1122 import_guid(&msg->u.resource_stat.guid, &raw->msg[idx]); 1123 idx += 16; 1124 if (idx > raw->curlen) 1125 goto fail_len; 1126 1127 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); 1128 idx++; 1129 return true; 1130fail_len: 1131 drm_dbg_kms(mgr->dev, "resource status reply parse length fail %d %d\n", idx, raw->curlen); 1132 return false; 1133} 1134 1135static bool drm_dp_sideband_parse_req(const struct drm_dp_mst_topology_mgr *mgr, 1136 struct drm_dp_sideband_msg_rx *raw, 1137 struct drm_dp_sideband_msg_req_body *msg) 1138{ 1139 memset(msg, 0, sizeof(*msg)); 1140 msg->req_type = (raw->msg[0] & 0x7f); 1141 1142 switch (msg->req_type) { 1143 case DP_CONNECTION_STATUS_NOTIFY: 1144 return drm_dp_sideband_parse_connection_status_notify(mgr, raw, msg); 1145 case DP_RESOURCE_STATUS_NOTIFY: 1146 return drm_dp_sideband_parse_resource_status_notify(mgr, raw, msg); 1147 default: 1148 drm_err(mgr->dev, "Got unknown request 0x%02x (%s)\n", 1149 msg->req_type, drm_dp_mst_req_type_str(msg->req_type)); 1150 return false; 1151 } 1152} 1153 1154static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, 1155 u8 port_num, u32 offset, u8 num_bytes, u8 *bytes) 1156{ 1157 struct drm_dp_sideband_msg_req_body req; 1158 1159 req.req_type = DP_REMOTE_DPCD_WRITE; 1160 req.u.dpcd_write.port_number = port_num; 1161 req.u.dpcd_write.dpcd_address = offset; 1162 req.u.dpcd_write.num_bytes = num_bytes; 1163 req.u.dpcd_write.bytes = bytes; 1164 drm_dp_encode_sideband_req(&req, msg); 1165} 1166 1167static void build_link_address(struct drm_dp_sideband_msg_tx *msg) 1168{ 1169 struct drm_dp_sideband_msg_req_body req; 1170 1171 req.req_type = DP_LINK_ADDRESS; 1172 drm_dp_encode_sideband_req(&req, msg); 1173} 1174 1175static void build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg) 1176{ 1177 struct drm_dp_sideband_msg_req_body req; 1178 1179 req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE; 1180 drm_dp_encode_sideband_req(&req, msg); 1181 msg->path_msg = true; 1182} 1183 1184static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, 1185 int port_num) 1186{ 1187 struct drm_dp_sideband_msg_req_body req; 1188 1189 req.req_type = DP_ENUM_PATH_RESOURCES; 1190 req.u.port_num.port_number = port_num; 1191 drm_dp_encode_sideband_req(&req, msg); 1192 msg->path_msg = true; 1193 return 0; 1194} 1195 1196static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, 1197 int port_num, 1198 u8 vcpi, uint16_t pbn, 1199 u8 number_sdp_streams, 1200 u8 *sdp_stream_sink) 1201{ 1202 struct drm_dp_sideband_msg_req_body req; 1203 1204 memset(&req, 0, sizeof(req)); 1205 req.req_type = DP_ALLOCATE_PAYLOAD; 1206 req.u.allocate_payload.port_number = port_num; 1207 req.u.allocate_payload.vcpi = vcpi; 1208 req.u.allocate_payload.pbn = pbn; 1209 req.u.allocate_payload.number_sdp_streams = number_sdp_streams; 1210 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink, 1211 number_sdp_streams); 1212 drm_dp_encode_sideband_req(&req, msg); 1213 msg->path_msg = true; 1214} 1215 1216static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg, 1217 int port_num, bool power_up) 1218{ 1219 struct drm_dp_sideband_msg_req_body req; 1220 1221 if (power_up) 1222 req.req_type = DP_POWER_UP_PHY; 1223 else 1224 req.req_type = DP_POWER_DOWN_PHY; 1225 1226 req.u.port_num.port_number = port_num; 1227 drm_dp_encode_sideband_req(&req, msg); 1228 msg->path_msg = true; 1229} 1230 1231static int 1232build_query_stream_enc_status(struct drm_dp_sideband_msg_tx *msg, u8 stream_id, 1233 u8 *q_id) 1234{ 1235 struct drm_dp_sideband_msg_req_body req; 1236 1237 req.req_type = DP_QUERY_STREAM_ENC_STATUS; 1238 req.u.enc_status.stream_id = stream_id; 1239 memcpy(req.u.enc_status.client_id, q_id, 1240 sizeof(req.u.enc_status.client_id)); 1241 req.u.enc_status.stream_event = 0; 1242 req.u.enc_status.valid_stream_event = false; 1243 req.u.enc_status.stream_behavior = 0; 1244 req.u.enc_status.valid_stream_behavior = false; 1245 1246 drm_dp_encode_sideband_req(&req, msg); 1247 return 0; 1248} 1249 1250static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr, 1251 struct drm_dp_sideband_msg_tx *txmsg) 1252{ 1253 unsigned int state; 1254 1255 /* 1256 * All updates to txmsg->state are protected by mgr->qlock, and the two 1257 * cases we check here are terminal states. For those the barriers 1258 * provided by the wake_up/wait_event pair are enough. 1259 */ 1260 state = READ_ONCE(txmsg->state); 1261 return (state == DRM_DP_SIDEBAND_TX_RX || 1262 state == DRM_DP_SIDEBAND_TX_TIMEOUT); 1263} 1264 1265static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb, 1266 struct drm_dp_sideband_msg_tx *txmsg) 1267{ 1268 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 1269 unsigned long wait_timeout = msecs_to_jiffies(4000); 1270 unsigned long wait_expires = jiffies + wait_timeout; 1271 int ret; 1272 1273 for (;;) { 1274 /* 1275 * If the driver provides a way for this, change to 1276 * poll-waiting for the MST reply interrupt if we didn't receive 1277 * it for 50 msec. This would cater for cases where the HPD 1278 * pulse signal got lost somewhere, even though the sink raised 1279 * the corresponding MST interrupt correctly. One example is the 1280 * Club 3D CAC-1557 TypeC -> DP adapter which for some reason 1281 * filters out short pulses with a duration less than ~540 usec. 1282 * 1283 * The poll period is 50 msec to avoid missing an interrupt 1284 * after the sink has cleared it (after a 110msec timeout 1285 * since it raised the interrupt). 1286 */ 1287 ret = wait_event_timeout(mgr->tx_waitq, 1288 check_txmsg_state(mgr, txmsg), 1289 mgr->cbs->poll_hpd_irq ? 1290 msecs_to_jiffies(50) : 1291 wait_timeout); 1292 1293 if (ret || !mgr->cbs->poll_hpd_irq || 1294 time_after(jiffies, wait_expires)) 1295 break; 1296 1297 mgr->cbs->poll_hpd_irq(mgr); 1298 } 1299 1300 mutex_lock(&mgr->qlock); 1301 if (ret > 0) { 1302 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) { 1303 ret = -EIO; 1304 goto out; 1305 } 1306 } else { 1307 drm_dbg_kms(mgr->dev, "timedout msg send %p %d %d\n", 1308 txmsg, txmsg->state, txmsg->seqno); 1309 1310 /* dump some state */ 1311 ret = -EIO; 1312 1313 /* remove from q */ 1314 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED || 1315 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND || 1316 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) 1317 list_del(&txmsg->next); 1318 } 1319out: 1320 if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) { 1321 struct drm_printer p = drm_dbg_printer(mgr->dev, DRM_UT_DP, 1322 DBG_PREFIX); 1323 1324 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 1325 } 1326 mutex_unlock(&mgr->qlock); 1327 1328 drm_dp_mst_kick_tx(mgr); 1329 return ret; 1330} 1331 1332static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad) 1333{ 1334 struct drm_dp_mst_branch *mstb; 1335 1336 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL); 1337 if (!mstb) 1338 return NULL; 1339 1340 mstb->lct = lct; 1341 if (lct > 1) 1342 memcpy(mstb->rad, rad, lct / 2); 1343 INIT_LIST_HEAD(&mstb->ports); 1344 kref_init(&mstb->topology_kref); 1345 kref_init(&mstb->malloc_kref); 1346 return mstb; 1347} 1348 1349static void drm_dp_free_mst_branch_device(struct kref *kref) 1350{ 1351 struct drm_dp_mst_branch *mstb = 1352 container_of(kref, struct drm_dp_mst_branch, malloc_kref); 1353 1354 if (mstb->port_parent) 1355 drm_dp_mst_put_port_malloc(mstb->port_parent); 1356 1357 kfree(mstb); 1358} 1359 1360/** 1361 * DOC: Branch device and port refcounting 1362 * 1363 * Topology refcount overview 1364 * ~~~~~~~~~~~~~~~~~~~~~~~~~~ 1365 * 1366 * The refcounting schemes for &struct drm_dp_mst_branch and &struct 1367 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have 1368 * two different kinds of refcounts: topology refcounts, and malloc refcounts. 1369 * 1370 * Topology refcounts are not exposed to drivers, and are handled internally 1371 * by the DP MST helpers. The helpers use them in order to prevent the 1372 * in-memory topology state from being changed in the middle of critical 1373 * operations like changing the internal state of payload allocations. This 1374 * means each branch and port will be considered to be connected to the rest 1375 * of the topology until its topology refcount reaches zero. Additionally, 1376 * for ports this means that their associated &struct drm_connector will stay 1377 * registered with userspace until the port's refcount reaches 0. 1378 * 1379 * Malloc refcount overview 1380 * ~~~~~~~~~~~~~~~~~~~~~~~~ 1381 * 1382 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct 1383 * drm_dp_mst_branch allocated even after all of its topology references have 1384 * been dropped, so that the driver or MST helpers can safely access each 1385 * branch's last known state before it was disconnected from the topology. 1386 * When the malloc refcount of a port or branch reaches 0, the memory 1387 * allocation containing the &struct drm_dp_mst_branch or &struct 1388 * drm_dp_mst_port respectively will be freed. 1389 * 1390 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed 1391 * to drivers. As of writing this documentation, there are no drivers that 1392 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST 1393 * helpers. Exposing this API to drivers in a race-free manner would take more 1394 * tweaking of the refcounting scheme, however patches are welcome provided 1395 * there is a legitimate driver usecase for this. 1396 * 1397 * Refcount relationships in a topology 1398 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1399 * 1400 * Let's take a look at why the relationship between topology and malloc 1401 * refcounts is designed the way it is. 1402 * 1403 * .. kernel-figure:: dp-mst/topology-figure-1.dot 1404 * 1405 * An example of topology and malloc refs in a DP MST topology with two 1406 * active payloads. Topology refcount increments are indicated by solid 1407 * lines, and malloc refcount increments are indicated by dashed lines. 1408 * Each starts from the branch which incremented the refcount, and ends at 1409 * the branch to which the refcount belongs to, i.e. the arrow points the 1410 * same way as the C pointers used to reference a structure. 1411 * 1412 * As you can see in the above figure, every branch increments the topology 1413 * refcount of its children, and increments the malloc refcount of its 1414 * parent. Additionally, every payload increments the malloc refcount of its 1415 * assigned port by 1. 1416 * 1417 * So, what would happen if MSTB #3 from the above figure was unplugged from 1418 * the system, but the driver hadn't yet removed payload #2 from port #3? The 1419 * topology would start to look like the figure below. 1420 * 1421 * .. kernel-figure:: dp-mst/topology-figure-2.dot 1422 * 1423 * Ports and branch devices which have been released from memory are 1424 * colored grey, and references which have been removed are colored red. 1425 * 1426 * Whenever a port or branch device's topology refcount reaches zero, it will 1427 * decrement the topology refcounts of all its children, the malloc refcount 1428 * of its parent, and finally its own malloc refcount. For MSTB #4 and port 1429 * #4, this means they both have been disconnected from the topology and freed 1430 * from memory. But, because payload #2 is still holding a reference to port 1431 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port 1432 * is still accessible from memory. This also means port #3 has not yet 1433 * decremented the malloc refcount of MSTB #3, so its &struct 1434 * drm_dp_mst_branch will also stay allocated in memory until port #3's 1435 * malloc refcount reaches 0. 1436 * 1437 * This relationship is necessary because in order to release payload #2, we 1438 * need to be able to figure out the last relative of port #3 that's still 1439 * connected to the topology. In this case, we would travel up the topology as 1440 * shown below. 1441 * 1442 * .. kernel-figure:: dp-mst/topology-figure-3.dot 1443 * 1444 * And finally, remove payload #2 by communicating with port #2 through 1445 * sideband transactions. 1446 */ 1447 1448/** 1449 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch 1450 * device 1451 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of 1452 * 1453 * Increments &drm_dp_mst_branch.malloc_kref. When 1454 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb 1455 * will be released and @mstb may no longer be used. 1456 * 1457 * See also: drm_dp_mst_put_mstb_malloc() 1458 */ 1459static void 1460drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb) 1461{ 1462 kref_get(&mstb->malloc_kref); 1463 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref)); 1464} 1465 1466/** 1467 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch 1468 * device 1469 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of 1470 * 1471 * Decrements &drm_dp_mst_branch.malloc_kref. When 1472 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb 1473 * will be released and @mstb may no longer be used. 1474 * 1475 * See also: drm_dp_mst_get_mstb_malloc() 1476 */ 1477static void 1478drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb) 1479{ 1480 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1); 1481 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device); 1482} 1483 1484static void drm_dp_free_mst_port(struct kref *kref) 1485{ 1486 struct drm_dp_mst_port *port = 1487 container_of(kref, struct drm_dp_mst_port, malloc_kref); 1488 1489 drm_dp_mst_put_mstb_malloc(port->parent); 1490 kfree(port); 1491} 1492 1493/** 1494 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port 1495 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of 1496 * 1497 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref 1498 * reaches 0, the memory allocation for @port will be released and @port may 1499 * no longer be used. 1500 * 1501 * Because @port could potentially be freed at any time by the DP MST helpers 1502 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this 1503 * function, drivers that which to make use of &struct drm_dp_mst_port should 1504 * ensure that they grab at least one main malloc reference to their MST ports 1505 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before 1506 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0. 1507 * 1508 * See also: drm_dp_mst_put_port_malloc() 1509 */ 1510void 1511drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port) 1512{ 1513 kref_get(&port->malloc_kref); 1514 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref)); 1515} 1516EXPORT_SYMBOL(drm_dp_mst_get_port_malloc); 1517 1518/** 1519 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port 1520 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of 1521 * 1522 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref 1523 * reaches 0, the memory allocation for @port will be released and @port may 1524 * no longer be used. 1525 * 1526 * See also: drm_dp_mst_get_port_malloc() 1527 */ 1528void 1529drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port) 1530{ 1531 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1); 1532 kref_put(&port->malloc_kref, drm_dp_free_mst_port); 1533} 1534EXPORT_SYMBOL(drm_dp_mst_put_port_malloc); 1535 1536#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 1537 1538#define STACK_DEPTH 8 1539 1540static noinline void 1541__topology_ref_save(struct drm_dp_mst_topology_mgr *mgr, 1542 struct drm_dp_mst_topology_ref_history *history, 1543 enum drm_dp_mst_topology_ref_type type) 1544{ 1545 struct drm_dp_mst_topology_ref_entry *entry = NULL; 1546 depot_stack_handle_t backtrace; 1547 ulong stack_entries[STACK_DEPTH]; 1548 uint n; 1549 int i; 1550 1551 n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1); 1552 backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL); 1553 if (!backtrace) 1554 return; 1555 1556 /* Try to find an existing entry for this backtrace */ 1557 for (i = 0; i < history->len; i++) { 1558 if (history->entries[i].backtrace == backtrace) { 1559 entry = &history->entries[i]; 1560 break; 1561 } 1562 } 1563 1564 /* Otherwise add one */ 1565 if (!entry) { 1566 struct drm_dp_mst_topology_ref_entry *new; 1567 int new_len = history->len + 1; 1568 1569 new = krealloc(history->entries, sizeof(*new) * new_len, 1570 GFP_KERNEL); 1571 if (!new) 1572 return; 1573 1574 entry = &new[history->len]; 1575 history->len = new_len; 1576 history->entries = new; 1577 1578 entry->backtrace = backtrace; 1579 entry->type = type; 1580 entry->count = 0; 1581 } 1582 entry->count++; 1583 entry->ts_nsec = ktime_get_ns(); 1584} 1585 1586static int 1587topology_ref_history_cmp(const void *a, const void *b) 1588{ 1589 const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b; 1590 1591 if (entry_a->ts_nsec > entry_b->ts_nsec) 1592 return 1; 1593 else if (entry_a->ts_nsec < entry_b->ts_nsec) 1594 return -1; 1595 else 1596 return 0; 1597} 1598 1599static inline const char * 1600topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type) 1601{ 1602 if (type == DRM_DP_MST_TOPOLOGY_REF_GET) 1603 return "get"; 1604 else 1605 return "put"; 1606} 1607 1608static void 1609__dump_topology_ref_history(struct drm_device *drm, 1610 struct drm_dp_mst_topology_ref_history *history, 1611 void *ptr, const char *type_str) 1612{ 1613 struct drm_printer p = drm_dbg_printer(drm, DRM_UT_DP, DBG_PREFIX); 1614 char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL); 1615 int i; 1616 1617 if (!buf) 1618 return; 1619 1620 if (!history->len) 1621 goto out; 1622 1623 /* First, sort the list so that it goes from oldest to newest 1624 * reference entry 1625 */ 1626 sort(history->entries, history->len, sizeof(*history->entries), 1627 topology_ref_history_cmp, NULL); 1628 1629 drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n", 1630 type_str, ptr); 1631 1632 for (i = 0; i < history->len; i++) { 1633 const struct drm_dp_mst_topology_ref_entry *entry = 1634 &history->entries[i]; 1635 u64 ts_nsec = entry->ts_nsec; 1636 u32 rem_nsec = do_div(ts_nsec, 1000000000); 1637 1638 stack_depot_snprint(entry->backtrace, buf, PAGE_SIZE, 4); 1639 1640 drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s", 1641 entry->count, 1642 topology_ref_type_to_str(entry->type), 1643 ts_nsec, rem_nsec / 1000, buf); 1644 } 1645 1646 /* Now free the history, since this is the only time we expose it */ 1647 kfree(history->entries); 1648out: 1649 kfree(buf); 1650} 1651 1652static __always_inline void 1653drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) 1654{ 1655 __dump_topology_ref_history(mstb->mgr->dev, &mstb->topology_ref_history, 1656 mstb, "MSTB"); 1657} 1658 1659static __always_inline void 1660drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) 1661{ 1662 __dump_topology_ref_history(port->mgr->dev, &port->topology_ref_history, 1663 port, "Port"); 1664} 1665 1666static __always_inline void 1667save_mstb_topology_ref(struct drm_dp_mst_branch *mstb, 1668 enum drm_dp_mst_topology_ref_type type) 1669{ 1670 __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type); 1671} 1672 1673static __always_inline void 1674save_port_topology_ref(struct drm_dp_mst_port *port, 1675 enum drm_dp_mst_topology_ref_type type) 1676{ 1677 __topology_ref_save(port->mgr, &port->topology_ref_history, type); 1678} 1679 1680static inline void 1681topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) 1682{ 1683 mutex_lock(&mgr->topology_ref_history_lock); 1684} 1685 1686static inline void 1687topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) 1688{ 1689 mutex_unlock(&mgr->topology_ref_history_lock); 1690} 1691#else 1692static inline void 1693topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {} 1694static inline void 1695topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {} 1696static inline void 1697drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {} 1698static inline void 1699drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {} 1700#define save_mstb_topology_ref(mstb, type) 1701#define save_port_topology_ref(port, type) 1702#endif 1703 1704struct drm_dp_mst_atomic_payload * 1705drm_atomic_get_mst_payload_state(struct drm_dp_mst_topology_state *state, 1706 struct drm_dp_mst_port *port) 1707{ 1708 struct drm_dp_mst_atomic_payload *payload; 1709 1710 list_for_each_entry(payload, &state->payloads, next) 1711 if (payload->port == port) 1712 return payload; 1713 1714 return NULL; 1715} 1716EXPORT_SYMBOL(drm_atomic_get_mst_payload_state); 1717 1718static void drm_dp_destroy_mst_branch_device(struct kref *kref) 1719{ 1720 struct drm_dp_mst_branch *mstb = 1721 container_of(kref, struct drm_dp_mst_branch, topology_kref); 1722 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 1723 1724 drm_dp_mst_dump_mstb_topology_history(mstb); 1725 1726 INIT_LIST_HEAD(&mstb->destroy_next); 1727 1728 /* 1729 * This can get called under mgr->mutex, so we need to perform the 1730 * actual destruction of the mstb in another worker 1731 */ 1732 mutex_lock(&mgr->delayed_destroy_lock); 1733 list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list); 1734 mutex_unlock(&mgr->delayed_destroy_lock); 1735 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work); 1736} 1737 1738/** 1739 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a 1740 * branch device unless it's zero 1741 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of 1742 * 1743 * Attempts to grab a topology reference to @mstb, if it hasn't yet been 1744 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has 1745 * reached 0). Holding a topology reference implies that a malloc reference 1746 * will be held to @mstb as long as the user holds the topology reference. 1747 * 1748 * Care should be taken to ensure that the user has at least one malloc 1749 * reference to @mstb. If you already have a topology reference to @mstb, you 1750 * should use drm_dp_mst_topology_get_mstb() instead. 1751 * 1752 * See also: 1753 * drm_dp_mst_topology_get_mstb() 1754 * drm_dp_mst_topology_put_mstb() 1755 * 1756 * Returns: 1757 * * 1: A topology reference was grabbed successfully 1758 * * 0: @port is no longer in the topology, no reference was grabbed 1759 */ 1760static int __must_check 1761drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb) 1762{ 1763 int ret; 1764 1765 topology_ref_history_lock(mstb->mgr); 1766 ret = kref_get_unless_zero(&mstb->topology_kref); 1767 if (ret) { 1768 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref)); 1769 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET); 1770 } 1771 1772 topology_ref_history_unlock(mstb->mgr); 1773 1774 return ret; 1775} 1776 1777/** 1778 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a 1779 * branch device 1780 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of 1781 * 1782 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or 1783 * not it's already reached 0. This is only valid to use in scenarios where 1784 * you are already guaranteed to have at least one active topology reference 1785 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used. 1786 * 1787 * See also: 1788 * drm_dp_mst_topology_try_get_mstb() 1789 * drm_dp_mst_topology_put_mstb() 1790 */ 1791static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb) 1792{ 1793 topology_ref_history_lock(mstb->mgr); 1794 1795 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET); 1796 WARN_ON(kref_read(&mstb->topology_kref) == 0); 1797 kref_get(&mstb->topology_kref); 1798 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref)); 1799 1800 topology_ref_history_unlock(mstb->mgr); 1801} 1802 1803/** 1804 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch 1805 * device 1806 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from 1807 * 1808 * Releases a topology reference from @mstb by decrementing 1809 * &drm_dp_mst_branch.topology_kref. 1810 * 1811 * See also: 1812 * drm_dp_mst_topology_try_get_mstb() 1813 * drm_dp_mst_topology_get_mstb() 1814 */ 1815static void 1816drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb) 1817{ 1818 topology_ref_history_lock(mstb->mgr); 1819 1820 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref) - 1); 1821 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT); 1822 1823 topology_ref_history_unlock(mstb->mgr); 1824 kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device); 1825} 1826 1827static void drm_dp_destroy_port(struct kref *kref) 1828{ 1829 struct drm_dp_mst_port *port = 1830 container_of(kref, struct drm_dp_mst_port, topology_kref); 1831 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 1832 1833 drm_dp_mst_dump_port_topology_history(port); 1834 1835 /* There's nothing that needs locking to destroy an input port yet */ 1836 if (port->input) { 1837 drm_dp_mst_put_port_malloc(port); 1838 return; 1839 } 1840 1841 drm_edid_free(port->cached_edid); 1842 1843 /* 1844 * we can't destroy the connector here, as we might be holding the 1845 * mode_config.mutex from an EDID retrieval 1846 */ 1847 mutex_lock(&mgr->delayed_destroy_lock); 1848 list_add(&port->next, &mgr->destroy_port_list); 1849 mutex_unlock(&mgr->delayed_destroy_lock); 1850 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work); 1851} 1852 1853/** 1854 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a 1855 * port unless it's zero 1856 * @port: &struct drm_dp_mst_port to increment the topology refcount of 1857 * 1858 * Attempts to grab a topology reference to @port, if it hasn't yet been 1859 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached 1860 * 0). Holding a topology reference implies that a malloc reference will be 1861 * held to @port as long as the user holds the topology reference. 1862 * 1863 * Care should be taken to ensure that the user has at least one malloc 1864 * reference to @port. If you already have a topology reference to @port, you 1865 * should use drm_dp_mst_topology_get_port() instead. 1866 * 1867 * See also: 1868 * drm_dp_mst_topology_get_port() 1869 * drm_dp_mst_topology_put_port() 1870 * 1871 * Returns: 1872 * * 1: A topology reference was grabbed successfully 1873 * * 0: @port is no longer in the topology, no reference was grabbed 1874 */ 1875static int __must_check 1876drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port) 1877{ 1878 int ret; 1879 1880 topology_ref_history_lock(port->mgr); 1881 ret = kref_get_unless_zero(&port->topology_kref); 1882 if (ret) { 1883 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref)); 1884 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET); 1885 } 1886 1887 topology_ref_history_unlock(port->mgr); 1888 return ret; 1889} 1890 1891/** 1892 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port 1893 * @port: The &struct drm_dp_mst_port to increment the topology refcount of 1894 * 1895 * Increments &drm_dp_mst_port.topology_refcount without checking whether or 1896 * not it's already reached 0. This is only valid to use in scenarios where 1897 * you are already guaranteed to have at least one active topology reference 1898 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used. 1899 * 1900 * See also: 1901 * drm_dp_mst_topology_try_get_port() 1902 * drm_dp_mst_topology_put_port() 1903 */ 1904static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port) 1905{ 1906 topology_ref_history_lock(port->mgr); 1907 1908 WARN_ON(kref_read(&port->topology_kref) == 0); 1909 kref_get(&port->topology_kref); 1910 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref)); 1911 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET); 1912 1913 topology_ref_history_unlock(port->mgr); 1914} 1915 1916/** 1917 * drm_dp_mst_topology_put_port() - release a topology reference to a port 1918 * @port: The &struct drm_dp_mst_port to release the topology reference from 1919 * 1920 * Releases a topology reference from @port by decrementing 1921 * &drm_dp_mst_port.topology_kref. 1922 * 1923 * See also: 1924 * drm_dp_mst_topology_try_get_port() 1925 * drm_dp_mst_topology_get_port() 1926 */ 1927static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port) 1928{ 1929 topology_ref_history_lock(port->mgr); 1930 1931 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref) - 1); 1932 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT); 1933 1934 topology_ref_history_unlock(port->mgr); 1935 kref_put(&port->topology_kref, drm_dp_destroy_port); 1936} 1937 1938static struct drm_dp_mst_branch * 1939drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb, 1940 struct drm_dp_mst_branch *to_find) 1941{ 1942 struct drm_dp_mst_port *port; 1943 struct drm_dp_mst_branch *rmstb; 1944 1945 if (to_find == mstb) 1946 return mstb; 1947 1948 list_for_each_entry(port, &mstb->ports, next) { 1949 if (port->mstb) { 1950 rmstb = drm_dp_mst_topology_get_mstb_validated_locked( 1951 port->mstb, to_find); 1952 if (rmstb) 1953 return rmstb; 1954 } 1955 } 1956 return NULL; 1957} 1958 1959static struct drm_dp_mst_branch * 1960drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr, 1961 struct drm_dp_mst_branch *mstb) 1962{ 1963 struct drm_dp_mst_branch *rmstb = NULL; 1964 1965 mutex_lock(&mgr->lock); 1966 if (mgr->mst_primary) { 1967 rmstb = drm_dp_mst_topology_get_mstb_validated_locked( 1968 mgr->mst_primary, mstb); 1969 1970 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb)) 1971 rmstb = NULL; 1972 } 1973 mutex_unlock(&mgr->lock); 1974 return rmstb; 1975} 1976 1977static struct drm_dp_mst_port * 1978drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb, 1979 struct drm_dp_mst_port *to_find) 1980{ 1981 struct drm_dp_mst_port *port, *mport; 1982 1983 list_for_each_entry(port, &mstb->ports, next) { 1984 if (port == to_find) 1985 return port; 1986 1987 if (port->mstb) { 1988 mport = drm_dp_mst_topology_get_port_validated_locked( 1989 port->mstb, to_find); 1990 if (mport) 1991 return mport; 1992 } 1993 } 1994 return NULL; 1995} 1996 1997static struct drm_dp_mst_port * 1998drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr, 1999 struct drm_dp_mst_port *port) 2000{ 2001 struct drm_dp_mst_port *rport = NULL; 2002 2003 mutex_lock(&mgr->lock); 2004 if (mgr->mst_primary) { 2005 rport = drm_dp_mst_topology_get_port_validated_locked( 2006 mgr->mst_primary, port); 2007 2008 if (rport && !drm_dp_mst_topology_try_get_port(rport)) 2009 rport = NULL; 2010 } 2011 mutex_unlock(&mgr->lock); 2012 return rport; 2013} 2014 2015static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num) 2016{ 2017 struct drm_dp_mst_port *port; 2018 int ret; 2019 2020 list_for_each_entry(port, &mstb->ports, next) { 2021 if (port->port_num == port_num) { 2022 ret = drm_dp_mst_topology_try_get_port(port); 2023 return ret ? port : NULL; 2024 } 2025 } 2026 2027 return NULL; 2028} 2029 2030/* 2031 * calculate a new RAD for this MST branch device 2032 * if parent has an LCT of 2 then it has 1 nibble of RAD, 2033 * if parent has an LCT of 3 then it has 2 nibbles of RAD, 2034 */ 2035static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port, 2036 u8 *rad) 2037{ 2038 int parent_lct = port->parent->lct; 2039 int shift = 4; 2040 int idx = (parent_lct - 1) / 2; 2041 2042 if (parent_lct > 1) { 2043 memcpy(rad, port->parent->rad, idx + 1); 2044 shift = (parent_lct % 2) ? 4 : 0; 2045 } else 2046 rad[0] = 0; 2047 2048 rad[idx] |= port->port_num << shift; 2049 return parent_lct + 1; 2050} 2051 2052static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs) 2053{ 2054 switch (pdt) { 2055 case DP_PEER_DEVICE_DP_LEGACY_CONV: 2056 case DP_PEER_DEVICE_SST_SINK: 2057 return true; 2058 case DP_PEER_DEVICE_MST_BRANCHING: 2059 /* For sst branch device */ 2060 if (!mcs) 2061 return true; 2062 2063 return false; 2064 } 2065 return true; 2066} 2067 2068static int 2069drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt, 2070 bool new_mcs) 2071{ 2072 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 2073 struct drm_dp_mst_branch *mstb; 2074 u8 rad[8], lct; 2075 int ret = 0; 2076 2077 if (port->pdt == new_pdt && port->mcs == new_mcs) 2078 return 0; 2079 2080 /* Teardown the old pdt, if there is one */ 2081 if (port->pdt != DP_PEER_DEVICE_NONE) { 2082 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { 2083 /* 2084 * If the new PDT would also have an i2c bus, 2085 * don't bother with reregistering it 2086 */ 2087 if (new_pdt != DP_PEER_DEVICE_NONE && 2088 drm_dp_mst_is_end_device(new_pdt, new_mcs)) { 2089 port->pdt = new_pdt; 2090 port->mcs = new_mcs; 2091 return 0; 2092 } 2093 2094 /* remove i2c over sideband */ 2095 drm_dp_mst_unregister_i2c_bus(port); 2096 } else { 2097 mutex_lock(&mgr->lock); 2098 drm_dp_mst_topology_put_mstb(port->mstb); 2099 port->mstb = NULL; 2100 mutex_unlock(&mgr->lock); 2101 } 2102 } 2103 2104 port->pdt = new_pdt; 2105 port->mcs = new_mcs; 2106 2107 if (port->pdt != DP_PEER_DEVICE_NONE) { 2108 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { 2109 /* add i2c over sideband */ 2110 ret = drm_dp_mst_register_i2c_bus(port); 2111 } else { 2112 lct = drm_dp_calculate_rad(port, rad); 2113 mstb = drm_dp_add_mst_branch_device(lct, rad); 2114 if (!mstb) { 2115 ret = -ENOMEM; 2116 drm_err(mgr->dev, "Failed to create MSTB for port %p", port); 2117 goto out; 2118 } 2119 2120 mutex_lock(&mgr->lock); 2121 port->mstb = mstb; 2122 mstb->mgr = port->mgr; 2123 mstb->port_parent = port; 2124 2125 /* 2126 * Make sure this port's memory allocation stays 2127 * around until its child MSTB releases it 2128 */ 2129 drm_dp_mst_get_port_malloc(port); 2130 mutex_unlock(&mgr->lock); 2131 2132 /* And make sure we send a link address for this */ 2133 ret = 1; 2134 } 2135 } 2136 2137out: 2138 if (ret < 0) 2139 port->pdt = DP_PEER_DEVICE_NONE; 2140 return ret; 2141} 2142 2143/** 2144 * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband 2145 * @aux: Fake sideband AUX CH 2146 * @offset: address of the (first) register to read 2147 * @buffer: buffer to store the register values 2148 * @size: number of bytes in @buffer 2149 * 2150 * Performs the same functionality for remote devices via 2151 * sideband messaging as drm_dp_dpcd_read() does for local 2152 * devices via actual AUX CH. 2153 * 2154 * Return: Number of bytes read, or negative error code on failure. 2155 */ 2156ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux, 2157 unsigned int offset, void *buffer, size_t size) 2158{ 2159 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, 2160 aux); 2161 2162 return drm_dp_send_dpcd_read(port->mgr, port, 2163 offset, size, buffer); 2164} 2165 2166/** 2167 * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband 2168 * @aux: Fake sideband AUX CH 2169 * @offset: address of the (first) register to write 2170 * @buffer: buffer containing the values to write 2171 * @size: number of bytes in @buffer 2172 * 2173 * Performs the same functionality for remote devices via 2174 * sideband messaging as drm_dp_dpcd_write() does for local 2175 * devices via actual AUX CH. 2176 * 2177 * Return: number of bytes written on success, negative error code on failure. 2178 */ 2179ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux, 2180 unsigned int offset, void *buffer, size_t size) 2181{ 2182 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, 2183 aux); 2184 2185 return drm_dp_send_dpcd_write(port->mgr, port, 2186 offset, size, buffer); 2187} 2188 2189static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, guid_t *guid) 2190{ 2191 int ret = 0; 2192 2193 guid_copy(&mstb->guid, guid); 2194 2195 if (!drm_dp_validate_guid(mstb->mgr, &mstb->guid)) { 2196 struct drm_dp_aux *aux; 2197 u8 buf[UUID_SIZE]; 2198 2199 export_guid(buf, &mstb->guid); 2200 2201 if (mstb->port_parent) 2202 aux = &mstb->port_parent->aux; 2203 else 2204 aux = mstb->mgr->aux; 2205 2206 ret = drm_dp_dpcd_write_data(aux, DP_GUID, buf, sizeof(buf)); 2207 } 2208 2209 return ret; 2210} 2211 2212static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb, 2213 int pnum, 2214 char *proppath, 2215 size_t proppath_size) 2216{ 2217 int i; 2218 char temp[8]; 2219 2220 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id); 2221 for (i = 0; i < (mstb->lct - 1); i++) { 2222 int shift = (i % 2) ? 0 : 4; 2223 int port_num = (mstb->rad[i / 2] >> shift) & 0xf; 2224 2225 snprintf(temp, sizeof(temp), "-%d", port_num); 2226 strlcat(proppath, temp, proppath_size); 2227 } 2228 snprintf(temp, sizeof(temp), "-%d", pnum); 2229 strlcat(proppath, temp, proppath_size); 2230} 2231 2232/** 2233 * drm_dp_mst_connector_late_register() - Late MST connector registration 2234 * @connector: The MST connector 2235 * @port: The MST port for this connector 2236 * 2237 * Helper to register the remote aux device for this MST port. Drivers should 2238 * call this from their mst connector's late_register hook to enable MST aux 2239 * devices. 2240 * 2241 * Return: 0 on success, negative error code on failure. 2242 */ 2243int drm_dp_mst_connector_late_register(struct drm_connector *connector, 2244 struct drm_dp_mst_port *port) 2245{ 2246 drm_dbg_kms(port->mgr->dev, "registering %s remote bus for %s\n", 2247 port->aux.name, connector->kdev->kobj.name); 2248 2249 port->aux.dev = connector->kdev; 2250 return drm_dp_aux_register_devnode(&port->aux); 2251} 2252EXPORT_SYMBOL(drm_dp_mst_connector_late_register); 2253 2254/** 2255 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration 2256 * @connector: The MST connector 2257 * @port: The MST port for this connector 2258 * 2259 * Helper to unregister the remote aux device for this MST port, registered by 2260 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst 2261 * connector's early_unregister hook. 2262 */ 2263void drm_dp_mst_connector_early_unregister(struct drm_connector *connector, 2264 struct drm_dp_mst_port *port) 2265{ 2266 drm_dbg_kms(port->mgr->dev, "unregistering %s remote bus for %s\n", 2267 port->aux.name, connector->kdev->kobj.name); 2268 drm_dp_aux_unregister_devnode(&port->aux); 2269} 2270EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister); 2271 2272static void 2273drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb, 2274 struct drm_dp_mst_port *port) 2275{ 2276 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 2277 char proppath[255]; 2278 int ret; 2279 2280 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath)); 2281 port->connector = mgr->cbs->add_connector(mgr, port, proppath); 2282 if (!port->connector) { 2283 ret = -ENOMEM; 2284 goto error; 2285 } 2286 2287 if (port->pdt != DP_PEER_DEVICE_NONE && 2288 drm_dp_mst_is_end_device(port->pdt, port->mcs) && 2289 drm_dp_mst_port_is_logical(port)) 2290 port->cached_edid = drm_edid_read_ddc(port->connector, 2291 &port->aux.ddc); 2292 2293 drm_connector_dynamic_register(port->connector); 2294 return; 2295 2296error: 2297 drm_err(mgr->dev, "Failed to create connector for port %p: %d\n", port, ret); 2298} 2299 2300/* 2301 * Drop a topology reference, and unlink the port from the in-memory topology 2302 * layout 2303 */ 2304static void 2305drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr, 2306 struct drm_dp_mst_port *port) 2307{ 2308 mutex_lock(&mgr->lock); 2309 port->parent->num_ports--; 2310 list_del(&port->next); 2311 mutex_unlock(&mgr->lock); 2312 drm_dp_mst_topology_put_port(port); 2313} 2314 2315static struct drm_dp_mst_port * 2316drm_dp_mst_add_port(struct drm_device *dev, 2317 struct drm_dp_mst_topology_mgr *mgr, 2318 struct drm_dp_mst_branch *mstb, u8 port_number) 2319{ 2320 struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL); 2321 2322 if (!port) 2323 return NULL; 2324 2325 kref_init(&port->topology_kref); 2326 kref_init(&port->malloc_kref); 2327 port->parent = mstb; 2328 port->port_num = port_number; 2329 port->mgr = mgr; 2330 port->aux.name = "DPMST"; 2331 port->aux.dev = dev->dev; 2332 port->aux.is_remote = true; 2333 2334 /* initialize the MST downstream port's AUX crc work queue */ 2335 port->aux.drm_dev = dev; 2336 drm_dp_remote_aux_init(&port->aux); 2337 2338 /* 2339 * Make sure the memory allocation for our parent branch stays 2340 * around until our own memory allocation is released 2341 */ 2342 drm_dp_mst_get_mstb_malloc(mstb); 2343 2344 return port; 2345} 2346 2347static int 2348drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb, 2349 struct drm_device *dev, 2350 struct drm_dp_link_addr_reply_port *port_msg) 2351{ 2352 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 2353 struct drm_dp_mst_port *port; 2354 int ret; 2355 u8 new_pdt = DP_PEER_DEVICE_NONE; 2356 bool new_mcs = 0; 2357 bool created = false, send_link_addr = false, changed = false; 2358 2359 port = drm_dp_get_port(mstb, port_msg->port_number); 2360 if (!port) { 2361 port = drm_dp_mst_add_port(dev, mgr, mstb, 2362 port_msg->port_number); 2363 if (!port) 2364 return -ENOMEM; 2365 created = true; 2366 changed = true; 2367 } else if (!port->input && port_msg->input_port && port->connector) { 2368 /* Since port->connector can't be changed here, we create a 2369 * new port if input_port changes from 0 to 1 2370 */ 2371 drm_dp_mst_topology_unlink_port(mgr, port); 2372 drm_dp_mst_topology_put_port(port); 2373 port = drm_dp_mst_add_port(dev, mgr, mstb, 2374 port_msg->port_number); 2375 if (!port) 2376 return -ENOMEM; 2377 changed = true; 2378 created = true; 2379 } else if (port->input && !port_msg->input_port) { 2380 changed = true; 2381 } else if (port->connector) { 2382 /* We're updating a port that's exposed to userspace, so do it 2383 * under lock 2384 */ 2385 drm_modeset_lock(&mgr->base.lock, NULL); 2386 2387 changed = port->ddps != port_msg->ddps || 2388 (port->ddps && 2389 (port->ldps != port_msg->legacy_device_plug_status || 2390 port->dpcd_rev != port_msg->dpcd_revision || 2391 port->mcs != port_msg->mcs || 2392 port->pdt != port_msg->peer_device_type || 2393 port->num_sdp_stream_sinks != 2394 port_msg->num_sdp_stream_sinks)); 2395 } 2396 2397 port->input = port_msg->input_port; 2398 if (!port->input) 2399 new_pdt = port_msg->peer_device_type; 2400 new_mcs = port_msg->mcs; 2401 port->ddps = port_msg->ddps; 2402 port->ldps = port_msg->legacy_device_plug_status; 2403 port->dpcd_rev = port_msg->dpcd_revision; 2404 port->num_sdp_streams = port_msg->num_sdp_streams; 2405 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks; 2406 2407 /* manage mstb port lists with mgr lock - take a reference 2408 for this list */ 2409 if (created) { 2410 mutex_lock(&mgr->lock); 2411 drm_dp_mst_topology_get_port(port); 2412 list_add(&port->next, &mstb->ports); 2413 mstb->num_ports++; 2414 mutex_unlock(&mgr->lock); 2415 } 2416 2417 /* 2418 * Reprobe PBN caps on both hotplug, and when re-probing the link 2419 * for our parent mstb 2420 */ 2421 if (port->ddps && !port->input) { 2422 ret = drm_dp_send_enum_path_resources(mgr, mstb, 2423 port); 2424 if (ret == 1) 2425 changed = true; 2426 } else { 2427 port->full_pbn = 0; 2428 } 2429 2430 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs); 2431 if (ret == 1) { 2432 send_link_addr = true; 2433 } else if (ret < 0) { 2434 drm_err(dev, "Failed to change PDT on port %p: %d\n", port, ret); 2435 goto fail; 2436 } 2437 2438 /* 2439 * If this port wasn't just created, then we're reprobing because 2440 * we're coming out of suspend. In this case, always resend the link 2441 * address if there's an MSTB on this port 2442 */ 2443 if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING && 2444 port->mcs) 2445 send_link_addr = true; 2446 2447 if (port->connector) 2448 drm_modeset_unlock(&mgr->base.lock); 2449 else if (!port->input) 2450 drm_dp_mst_port_add_connector(mstb, port); 2451 2452 if (send_link_addr && port->mstb) { 2453 ret = drm_dp_send_link_address(mgr, port->mstb); 2454 if (ret == 1) /* MSTB below us changed */ 2455 changed = true; 2456 else if (ret < 0) 2457 goto fail_put; 2458 } 2459 2460 /* put reference to this port */ 2461 drm_dp_mst_topology_put_port(port); 2462 return changed; 2463 2464fail: 2465 drm_dp_mst_topology_unlink_port(mgr, port); 2466 if (port->connector) 2467 drm_modeset_unlock(&mgr->base.lock); 2468fail_put: 2469 drm_dp_mst_topology_put_port(port); 2470 return ret; 2471} 2472 2473static int 2474drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb, 2475 struct drm_dp_connection_status_notify *conn_stat) 2476{ 2477 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 2478 struct drm_dp_mst_port *port; 2479 int old_ddps, ret; 2480 u8 new_pdt; 2481 bool new_mcs; 2482 bool dowork = false, create_connector = false; 2483 2484 port = drm_dp_get_port(mstb, conn_stat->port_number); 2485 if (!port) 2486 return 0; 2487 2488 if (port->connector) { 2489 if (!port->input && conn_stat->input_port) { 2490 /* 2491 * We can't remove a connector from an already exposed 2492 * port, so just throw the port out and make sure we 2493 * reprobe the link address of it's parent MSTB 2494 */ 2495 drm_dp_mst_topology_unlink_port(mgr, port); 2496 mstb->link_address_sent = false; 2497 dowork = true; 2498 goto out; 2499 } 2500 2501 /* Locking is only needed if the port's exposed to userspace */ 2502 drm_modeset_lock(&mgr->base.lock, NULL); 2503 } else if (port->input && !conn_stat->input_port) { 2504 create_connector = true; 2505 /* Reprobe link address so we get num_sdp_streams */ 2506 mstb->link_address_sent = false; 2507 dowork = true; 2508 } 2509 2510 old_ddps = port->ddps; 2511 port->input = conn_stat->input_port; 2512 port->ldps = conn_stat->legacy_device_plug_status; 2513 port->ddps = conn_stat->displayport_device_plug_status; 2514 2515 if (old_ddps != port->ddps) { 2516 if (port->ddps && !port->input) 2517 drm_dp_send_enum_path_resources(mgr, mstb, port); 2518 else 2519 port->full_pbn = 0; 2520 } 2521 2522 new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type; 2523 new_mcs = conn_stat->message_capability_status; 2524 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs); 2525 if (ret == 1) { 2526 dowork = true; 2527 } else if (ret < 0) { 2528 drm_err(mgr->dev, "Failed to change PDT for port %p: %d\n", port, ret); 2529 dowork = false; 2530 } 2531 2532 if (port->connector) 2533 drm_modeset_unlock(&mgr->base.lock); 2534 else if (create_connector) 2535 drm_dp_mst_port_add_connector(mstb, port); 2536 2537out: 2538 drm_dp_mst_topology_put_port(port); 2539 return dowork; 2540} 2541 2542static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr, 2543 u8 lct, u8 *rad) 2544{ 2545 struct drm_dp_mst_branch *mstb; 2546 struct drm_dp_mst_port *port; 2547 int i, ret; 2548 /* find the port by iterating down */ 2549 2550 mutex_lock(&mgr->lock); 2551 mstb = mgr->mst_primary; 2552 2553 if (!mstb) 2554 goto out; 2555 2556 for (i = 1; i < lct; i++) { 2557 int port_num = drm_dp_mst_get_ufp_num_at_lct_from_rad(i + 1, rad); 2558 2559 list_for_each_entry(port, &mstb->ports, next) { 2560 if (port->port_num == port_num) { 2561 mstb = port->mstb; 2562 if (!mstb) { 2563 drm_err(mgr->dev, 2564 "failed to lookup MSTB with lct %d, rad %02x\n", 2565 lct, rad[0]); 2566 goto out; 2567 } 2568 2569 break; 2570 } 2571 } 2572 } 2573 ret = drm_dp_mst_topology_try_get_mstb(mstb); 2574 if (!ret) 2575 mstb = NULL; 2576out: 2577 mutex_unlock(&mgr->lock); 2578 return mstb; 2579} 2580 2581static struct drm_dp_mst_branch * 2582get_mst_branch_device_by_guid_helper(struct drm_dp_mst_branch *mstb, 2583 const guid_t *guid) 2584{ 2585 struct drm_dp_mst_branch *found_mstb; 2586 struct drm_dp_mst_port *port; 2587 2588 if (!mstb) 2589 return NULL; 2590 2591 if (guid_equal(&mstb->guid, guid)) 2592 return mstb; 2593 2594 list_for_each_entry(port, &mstb->ports, next) { 2595 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid); 2596 2597 if (found_mstb) 2598 return found_mstb; 2599 } 2600 2601 return NULL; 2602} 2603 2604static struct drm_dp_mst_branch * 2605drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr, 2606 const guid_t *guid) 2607{ 2608 struct drm_dp_mst_branch *mstb; 2609 int ret; 2610 2611 /* find the port by iterating down */ 2612 mutex_lock(&mgr->lock); 2613 2614 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid); 2615 if (mstb) { 2616 ret = drm_dp_mst_topology_try_get_mstb(mstb); 2617 if (!ret) 2618 mstb = NULL; 2619 } 2620 2621 mutex_unlock(&mgr->lock); 2622 return mstb; 2623} 2624 2625static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 2626 struct drm_dp_mst_branch *mstb) 2627{ 2628 struct drm_dp_mst_port *port; 2629 int ret; 2630 bool changed = false; 2631 2632 if (!mstb->link_address_sent) { 2633 ret = drm_dp_send_link_address(mgr, mstb); 2634 if (ret == 1) 2635 changed = true; 2636 else if (ret < 0) 2637 return ret; 2638 } 2639 2640 list_for_each_entry(port, &mstb->ports, next) { 2641 if (port->input || !port->ddps || !port->mstb) 2642 continue; 2643 2644 ret = drm_dp_check_and_send_link_address(mgr, port->mstb); 2645 if (ret == 1) 2646 changed = true; 2647 else if (ret < 0) 2648 return ret; 2649 } 2650 2651 return changed; 2652} 2653 2654static void drm_dp_mst_link_probe_work(struct work_struct *work) 2655{ 2656 struct drm_dp_mst_topology_mgr *mgr = 2657 container_of(work, struct drm_dp_mst_topology_mgr, work); 2658 struct drm_device *dev = mgr->dev; 2659 struct drm_dp_mst_branch *mstb; 2660 int ret; 2661 bool clear_payload_id_table; 2662 2663 mutex_lock(&mgr->probe_lock); 2664 2665 mutex_lock(&mgr->lock); 2666 clear_payload_id_table = !mgr->payload_id_table_cleared; 2667 mgr->payload_id_table_cleared = true; 2668 2669 mstb = mgr->mst_primary; 2670 if (mstb) { 2671 ret = drm_dp_mst_topology_try_get_mstb(mstb); 2672 if (!ret) 2673 mstb = NULL; 2674 } 2675 mutex_unlock(&mgr->lock); 2676 if (!mstb) { 2677 mutex_unlock(&mgr->probe_lock); 2678 return; 2679 } 2680 2681 /* 2682 * Certain branch devices seem to incorrectly report an available_pbn 2683 * of 0 on downstream sinks, even after clearing the 2684 * DP_PAYLOAD_ALLOCATE_* registers in 2685 * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C 2686 * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make 2687 * things work again. 2688 */ 2689 if (clear_payload_id_table) { 2690 drm_dbg_kms(dev, "Clearing payload ID table\n"); 2691 drm_dp_send_clear_payload_id_table(mgr, mstb); 2692 } 2693 2694 ret = drm_dp_check_and_send_link_address(mgr, mstb); 2695 drm_dp_mst_topology_put_mstb(mstb); 2696 2697 mutex_unlock(&mgr->probe_lock); 2698 if (ret > 0) 2699 drm_kms_helper_hotplug_event(dev); 2700} 2701 2702static void drm_dp_mst_queue_probe_work(struct drm_dp_mst_topology_mgr *mgr) 2703{ 2704 queue_work(system_long_wq, &mgr->work); 2705} 2706 2707static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, 2708 guid_t *guid) 2709{ 2710 if (!guid_is_null(guid)) 2711 return true; 2712 2713 guid_gen(guid); 2714 2715 return false; 2716} 2717 2718static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, 2719 u8 port_num, u32 offset, u8 num_bytes) 2720{ 2721 struct drm_dp_sideband_msg_req_body req; 2722 2723 req.req_type = DP_REMOTE_DPCD_READ; 2724 req.u.dpcd_read.port_number = port_num; 2725 req.u.dpcd_read.dpcd_address = offset; 2726 req.u.dpcd_read.num_bytes = num_bytes; 2727 drm_dp_encode_sideband_req(&req, msg); 2728} 2729 2730static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr, 2731 bool up, u8 *msg, int len) 2732{ 2733 int ret; 2734 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE; 2735 int tosend, total, offset; 2736 int retries = 0; 2737 2738retry: 2739 total = len; 2740 offset = 0; 2741 do { 2742 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total); 2743 2744 ret = drm_dp_dpcd_write_data(mgr->aux, regbase + offset, 2745 &msg[offset], 2746 tosend); 2747 if (ret == -EIO && retries < 5) { 2748 retries++; 2749 goto retry; 2750 } else if (ret < 0) { 2751 drm_dbg_kms(mgr->dev, "failed to dpcd write %d %d\n", tosend, ret); 2752 2753 return -EIO; 2754 } 2755 offset += tosend; 2756 total -= tosend; 2757 } while (total > 0); 2758 return 0; 2759} 2760 2761static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr, 2762 struct drm_dp_sideband_msg_tx *txmsg) 2763{ 2764 struct drm_dp_mst_branch *mstb = txmsg->dst; 2765 u8 req_type; 2766 2767 req_type = txmsg->msg[0] & 0x7f; 2768 if (req_type == DP_CONNECTION_STATUS_NOTIFY || 2769 req_type == DP_RESOURCE_STATUS_NOTIFY || 2770 req_type == DP_CLEAR_PAYLOAD_ID_TABLE) 2771 hdr->broadcast = 1; 2772 else 2773 hdr->broadcast = 0; 2774 hdr->path_msg = txmsg->path_msg; 2775 if (hdr->broadcast) { 2776 hdr->lct = 1; 2777 hdr->lcr = 6; 2778 } else { 2779 hdr->lct = mstb->lct; 2780 hdr->lcr = mstb->lct - 1; 2781 } 2782 2783 memcpy(hdr->rad, mstb->rad, hdr->lct / 2); 2784 2785 return 0; 2786} 2787/* 2788 * process a single block of the next message in the sideband queue 2789 */ 2790static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr, 2791 struct drm_dp_sideband_msg_tx *txmsg, 2792 bool up) 2793{ 2794 u8 chunk[48]; 2795 struct drm_dp_sideband_msg_hdr hdr; 2796 int len, space, idx, tosend; 2797 int ret; 2798 2799 if (txmsg->state == DRM_DP_SIDEBAND_TX_SENT) 2800 return 0; 2801 2802 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr)); 2803 2804 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) 2805 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND; 2806 2807 /* make hdr from dst mst */ 2808 ret = set_hdr_from_dst_qlock(&hdr, txmsg); 2809 if (ret < 0) 2810 return ret; 2811 2812 /* amount left to send in this message */ 2813 len = txmsg->cur_len - txmsg->cur_offset; 2814 2815 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */ 2816 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr); 2817 2818 tosend = min(len, space); 2819 if (len == txmsg->cur_len) 2820 hdr.somt = 1; 2821 if (space >= len) 2822 hdr.eomt = 1; 2823 2824 2825 hdr.msg_len = tosend + 1; 2826 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx); 2827 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend); 2828 /* add crc at end */ 2829 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend); 2830 idx += tosend + 1; 2831 2832 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx); 2833 if (ret) { 2834 if (drm_debug_enabled(DRM_UT_DP)) { 2835 struct drm_printer p = drm_dbg_printer(mgr->dev, 2836 DRM_UT_DP, 2837 DBG_PREFIX); 2838 2839 drm_printf(&p, "sideband msg failed to send\n"); 2840 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 2841 } 2842 return ret; 2843 } 2844 2845 txmsg->cur_offset += tosend; 2846 if (txmsg->cur_offset == txmsg->cur_len) { 2847 txmsg->state = DRM_DP_SIDEBAND_TX_SENT; 2848 return 1; 2849 } 2850 return 0; 2851} 2852 2853static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr) 2854{ 2855 struct drm_dp_sideband_msg_tx *txmsg; 2856 int ret; 2857 2858 WARN_ON(!mutex_is_locked(&mgr->qlock)); 2859 2860 /* construct a chunk from the first msg in the tx_msg queue */ 2861 if (list_empty(&mgr->tx_msg_downq)) 2862 return; 2863 2864 txmsg = list_first_entry(&mgr->tx_msg_downq, 2865 struct drm_dp_sideband_msg_tx, next); 2866 ret = process_single_tx_qlock(mgr, txmsg, false); 2867 if (ret < 0) { 2868 drm_dbg_kms(mgr->dev, "failed to send msg in q %d\n", ret); 2869 list_del(&txmsg->next); 2870 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 2871 wake_up_all(&mgr->tx_waitq); 2872 } 2873} 2874 2875static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr, 2876 struct drm_dp_sideband_msg_tx *txmsg) 2877{ 2878 mutex_lock(&mgr->qlock); 2879 list_add_tail(&txmsg->next, &mgr->tx_msg_downq); 2880 2881 if (drm_debug_enabled(DRM_UT_DP)) { 2882 struct drm_printer p = drm_dbg_printer(mgr->dev, DRM_UT_DP, 2883 DBG_PREFIX); 2884 2885 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 2886 } 2887 2888 if (list_is_singular(&mgr->tx_msg_downq)) 2889 process_single_down_tx_qlock(mgr); 2890 mutex_unlock(&mgr->qlock); 2891} 2892 2893static void 2894drm_dp_dump_link_address(const struct drm_dp_mst_topology_mgr *mgr, 2895 struct drm_dp_link_address_ack_reply *reply) 2896{ 2897 struct drm_dp_link_addr_reply_port *port_reply; 2898 int i; 2899 2900 for (i = 0; i < reply->nports; i++) { 2901 port_reply = &reply->ports[i]; 2902 drm_dbg_kms(mgr->dev, 2903 "port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", 2904 i, 2905 port_reply->input_port, 2906 port_reply->peer_device_type, 2907 port_reply->port_number, 2908 port_reply->dpcd_revision, 2909 port_reply->mcs, 2910 port_reply->ddps, 2911 port_reply->legacy_device_plug_status, 2912 port_reply->num_sdp_streams, 2913 port_reply->num_sdp_stream_sinks); 2914 } 2915} 2916 2917static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 2918 struct drm_dp_mst_branch *mstb) 2919{ 2920 struct drm_dp_sideband_msg_tx *txmsg; 2921 struct drm_dp_link_address_ack_reply *reply; 2922 struct drm_dp_mst_port *port, *tmp; 2923 int i, ret, port_mask = 0; 2924 bool changed = false; 2925 2926 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 2927 if (!txmsg) 2928 return -ENOMEM; 2929 2930 txmsg->dst = mstb; 2931 build_link_address(txmsg); 2932 2933 mstb->link_address_sent = true; 2934 drm_dp_queue_down_tx(mgr, txmsg); 2935 2936 /* FIXME: Actually do some real error handling here */ 2937 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 2938 if (ret < 0) { 2939 drm_err(mgr->dev, "Sending link address failed with %d\n", ret); 2940 goto out; 2941 } 2942 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 2943 drm_err(mgr->dev, "link address NAK received\n"); 2944 ret = -EIO; 2945 goto out; 2946 } 2947 2948 reply = &txmsg->reply.u.link_addr; 2949 drm_dbg_kms(mgr->dev, "link address reply: %d\n", reply->nports); 2950 drm_dp_dump_link_address(mgr, reply); 2951 2952 ret = drm_dp_check_mstb_guid(mstb, &reply->guid); 2953 if (ret) { 2954 char buf[64]; 2955 2956 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf)); 2957 drm_err(mgr->dev, "GUID check on %s failed: %d\n", buf, ret); 2958 goto out; 2959 } 2960 2961 for (i = 0; i < reply->nports; i++) { 2962 port_mask |= BIT(reply->ports[i].port_number); 2963 ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev, 2964 &reply->ports[i]); 2965 if (ret == 1) 2966 changed = true; 2967 else if (ret < 0) 2968 goto out; 2969 } 2970 2971 /* Prune any ports that are currently a part of mstb in our in-memory 2972 * topology, but were not seen in this link address. Usually this 2973 * means that they were removed while the topology was out of sync, 2974 * e.g. during suspend/resume 2975 */ 2976 mutex_lock(&mgr->lock); 2977 list_for_each_entry_safe(port, tmp, &mstb->ports, next) { 2978 if (port_mask & BIT(port->port_num)) 2979 continue; 2980 2981 drm_dbg_kms(mgr->dev, "port %d was not in link address, removing\n", 2982 port->port_num); 2983 list_del(&port->next); 2984 drm_dp_mst_topology_put_port(port); 2985 changed = true; 2986 } 2987 mutex_unlock(&mgr->lock); 2988 2989out: 2990 if (ret < 0) 2991 mstb->link_address_sent = false; 2992 kfree(txmsg); 2993 return ret < 0 ? ret : changed; 2994} 2995 2996static void 2997drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr, 2998 struct drm_dp_mst_branch *mstb) 2999{ 3000 struct drm_dp_sideband_msg_tx *txmsg; 3001 int ret; 3002 3003 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3004 if (!txmsg) 3005 return; 3006 3007 txmsg->dst = mstb; 3008 build_clear_payload_id_table(txmsg); 3009 3010 drm_dp_queue_down_tx(mgr, txmsg); 3011 3012 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3013 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3014 drm_dbg_kms(mgr->dev, "clear payload table id nak received\n"); 3015 3016 kfree(txmsg); 3017} 3018 3019static int 3020drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, 3021 struct drm_dp_mst_branch *mstb, 3022 struct drm_dp_mst_port *port) 3023{ 3024 struct drm_dp_enum_path_resources_ack_reply *path_res; 3025 struct drm_dp_sideband_msg_tx *txmsg; 3026 int ret; 3027 3028 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3029 if (!txmsg) 3030 return -ENOMEM; 3031 3032 txmsg->dst = mstb; 3033 build_enum_path_resources(txmsg, port->port_num); 3034 3035 drm_dp_queue_down_tx(mgr, txmsg); 3036 3037 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3038 if (ret > 0) { 3039 ret = 0; 3040 path_res = &txmsg->reply.u.path_resources; 3041 3042 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3043 drm_dbg_kms(mgr->dev, "enum path resources nak received\n"); 3044 } else { 3045 if (port->port_num != path_res->port_number) 3046 DRM_ERROR("got incorrect port in response\n"); 3047 3048 drm_dbg_kms(mgr->dev, "enum path resources %d: %d %d\n", 3049 path_res->port_number, 3050 path_res->full_payload_bw_number, 3051 path_res->avail_payload_bw_number); 3052 3053 /* 3054 * If something changed, make sure we send a 3055 * hotplug 3056 */ 3057 if (port->full_pbn != path_res->full_payload_bw_number || 3058 port->fec_capable != path_res->fec_capable) 3059 ret = 1; 3060 3061 port->full_pbn = path_res->full_payload_bw_number; 3062 port->fec_capable = path_res->fec_capable; 3063 } 3064 } 3065 3066 kfree(txmsg); 3067 return ret; 3068} 3069 3070static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb) 3071{ 3072 if (!mstb->port_parent) 3073 return NULL; 3074 3075 if (mstb->port_parent->mstb != mstb) 3076 return mstb->port_parent; 3077 3078 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent); 3079} 3080 3081/* 3082 * Searches upwards in the topology starting from mstb to try to find the 3083 * closest available parent of mstb that's still connected to the rest of the 3084 * topology. This can be used in order to perform operations like releasing 3085 * payloads, where the branch device which owned the payload may no longer be 3086 * around and thus would require that the payload on the last living relative 3087 * be freed instead. 3088 */ 3089static struct drm_dp_mst_branch * 3090drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr, 3091 struct drm_dp_mst_branch *mstb, 3092 int *port_num) 3093{ 3094 struct drm_dp_mst_branch *rmstb = NULL; 3095 struct drm_dp_mst_port *found_port; 3096 3097 mutex_lock(&mgr->lock); 3098 if (!mgr->mst_primary) 3099 goto out; 3100 3101 do { 3102 found_port = drm_dp_get_last_connected_port_to_mstb(mstb); 3103 if (!found_port) 3104 break; 3105 3106 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) { 3107 rmstb = found_port->parent; 3108 *port_num = found_port->port_num; 3109 } else { 3110 /* Search again, starting from this parent */ 3111 mstb = found_port->parent; 3112 } 3113 } while (!rmstb); 3114out: 3115 mutex_unlock(&mgr->lock); 3116 return rmstb; 3117} 3118 3119static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr, 3120 struct drm_dp_mst_port *port, 3121 int id, 3122 int pbn) 3123{ 3124 struct drm_dp_sideband_msg_tx *txmsg; 3125 struct drm_dp_mst_branch *mstb; 3126 int ret, port_num; 3127 u8 sinks[DRM_DP_MAX_SDP_STREAMS]; 3128 int i; 3129 3130 port_num = port->port_num; 3131 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 3132 if (!mstb) { 3133 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, 3134 port->parent, 3135 &port_num); 3136 3137 if (!mstb) 3138 return -EINVAL; 3139 } 3140 3141 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3142 if (!txmsg) { 3143 ret = -ENOMEM; 3144 goto fail_put; 3145 } 3146 3147 for (i = 0; i < port->num_sdp_streams; i++) 3148 sinks[i] = i; 3149 3150 txmsg->dst = mstb; 3151 build_allocate_payload(txmsg, port_num, 3152 id, 3153 pbn, port->num_sdp_streams, sinks); 3154 3155 drm_dp_queue_down_tx(mgr, txmsg); 3156 3157 /* 3158 * FIXME: there is a small chance that between getting the last 3159 * connected mstb and sending the payload message, the last connected 3160 * mstb could also be removed from the topology. In the future, this 3161 * needs to be fixed by restarting the 3162 * drm_dp_get_last_connected_port_and_mstb() search in the event of a 3163 * timeout if the topology is still connected to the system. 3164 */ 3165 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3166 if (ret > 0) { 3167 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3168 ret = -EINVAL; 3169 else 3170 ret = 0; 3171 } 3172 kfree(txmsg); 3173fail_put: 3174 drm_dp_mst_topology_put_mstb(mstb); 3175 return ret; 3176} 3177 3178int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr, 3179 struct drm_dp_mst_port *port, bool power_up) 3180{ 3181 struct drm_dp_sideband_msg_tx *txmsg; 3182 int ret; 3183 3184 port = drm_dp_mst_topology_get_port_validated(mgr, port); 3185 if (!port) 3186 return -EINVAL; 3187 3188 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3189 if (!txmsg) { 3190 drm_dp_mst_topology_put_port(port); 3191 return -ENOMEM; 3192 } 3193 3194 txmsg->dst = port->parent; 3195 build_power_updown_phy(txmsg, port->port_num, power_up); 3196 drm_dp_queue_down_tx(mgr, txmsg); 3197 3198 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg); 3199 if (ret > 0) { 3200 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3201 ret = -EINVAL; 3202 else 3203 ret = 0; 3204 } 3205 kfree(txmsg); 3206 drm_dp_mst_topology_put_port(port); 3207 3208 return ret; 3209} 3210EXPORT_SYMBOL(drm_dp_send_power_updown_phy); 3211 3212int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr, 3213 struct drm_dp_mst_port *port, 3214 struct drm_dp_query_stream_enc_status_ack_reply *status) 3215{ 3216 struct drm_dp_mst_topology_state *state; 3217 struct drm_dp_mst_atomic_payload *payload; 3218 struct drm_dp_sideband_msg_tx *txmsg; 3219 u8 nonce[7]; 3220 int ret; 3221 3222 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3223 if (!txmsg) 3224 return -ENOMEM; 3225 3226 port = drm_dp_mst_topology_get_port_validated(mgr, port); 3227 if (!port) { 3228 ret = -EINVAL; 3229 goto out_get_port; 3230 } 3231 3232 get_random_bytes(nonce, sizeof(nonce)); 3233 3234 drm_modeset_lock(&mgr->base.lock, NULL); 3235 state = to_drm_dp_mst_topology_state(mgr->base.state); 3236 payload = drm_atomic_get_mst_payload_state(state, port); 3237 3238 /* 3239 * "Source device targets the QUERY_STREAM_ENCRYPTION_STATUS message 3240 * transaction at the MST Branch device directly connected to the 3241 * Source" 3242 */ 3243 txmsg->dst = mgr->mst_primary; 3244 3245 build_query_stream_enc_status(txmsg, payload->vcpi, nonce); 3246 3247 drm_dp_queue_down_tx(mgr, txmsg); 3248 3249 ret = drm_dp_mst_wait_tx_reply(mgr->mst_primary, txmsg); 3250 if (ret < 0) { 3251 goto out; 3252 } else if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3253 drm_dbg_kms(mgr->dev, "query encryption status nak received\n"); 3254 ret = -ENXIO; 3255 goto out; 3256 } 3257 3258 ret = 0; 3259 memcpy(status, &txmsg->reply.u.enc_status, sizeof(*status)); 3260 3261out: 3262 drm_modeset_unlock(&mgr->base.lock); 3263 drm_dp_mst_topology_put_port(port); 3264out_get_port: 3265 kfree(txmsg); 3266 return ret; 3267} 3268EXPORT_SYMBOL(drm_dp_send_query_stream_enc_status); 3269 3270static int drm_dp_create_payload_at_dfp(struct drm_dp_mst_topology_mgr *mgr, 3271 struct drm_dp_mst_atomic_payload *payload) 3272{ 3273 return drm_dp_dpcd_write_payload(mgr->aux, payload->vcpi, payload->vc_start_slot, 3274 payload->time_slots); 3275} 3276 3277static int drm_dp_create_payload_to_remote(struct drm_dp_mst_topology_mgr *mgr, 3278 struct drm_dp_mst_atomic_payload *payload) 3279{ 3280 int ret; 3281 struct drm_dp_mst_port *port = drm_dp_mst_topology_get_port_validated(mgr, payload->port); 3282 3283 if (!port) 3284 return -EIO; 3285 3286 ret = drm_dp_payload_send_msg(mgr, port, payload->vcpi, payload->pbn); 3287 drm_dp_mst_topology_put_port(port); 3288 return ret; 3289} 3290 3291static void drm_dp_destroy_payload_at_remote_and_dfp(struct drm_dp_mst_topology_mgr *mgr, 3292 struct drm_dp_mst_topology_state *mst_state, 3293 struct drm_dp_mst_atomic_payload *payload) 3294{ 3295 drm_dbg_kms(mgr->dev, "\n"); 3296 3297 /* it's okay for these to fail */ 3298 if (payload->payload_allocation_status == DRM_DP_MST_PAYLOAD_ALLOCATION_REMOTE) { 3299 drm_dp_payload_send_msg(mgr, payload->port, payload->vcpi, 0); 3300 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_DFP; 3301 } 3302 3303 if (payload->payload_allocation_status == DRM_DP_MST_PAYLOAD_ALLOCATION_DFP) 3304 drm_dp_dpcd_write_payload(mgr->aux, payload->vcpi, payload->vc_start_slot, 0); 3305} 3306 3307/** 3308 * drm_dp_add_payload_part1() - Execute payload update part 1 3309 * @mgr: Manager to use. 3310 * @mst_state: The MST atomic state 3311 * @payload: The payload to write 3312 * 3313 * Determines the starting time slot for the given payload, and programs the VCPI for this payload 3314 * into the DPCD of DPRX. After calling this, the driver should generate ACT and payload packets. 3315 * 3316 * Returns: 0 on success, error code on failure. 3317 */ 3318int drm_dp_add_payload_part1(struct drm_dp_mst_topology_mgr *mgr, 3319 struct drm_dp_mst_topology_state *mst_state, 3320 struct drm_dp_mst_atomic_payload *payload) 3321{ 3322 struct drm_dp_mst_port *port; 3323 int ret; 3324 3325 /* Update mst mgr info */ 3326 if (mgr->payload_count == 0) 3327 mgr->next_start_slot = mst_state->start_slot; 3328 3329 payload->vc_start_slot = mgr->next_start_slot; 3330 3331 mgr->payload_count++; 3332 mgr->next_start_slot += payload->time_slots; 3333 3334 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_LOCAL; 3335 3336 /* Allocate payload to immediate downstream facing port */ 3337 port = drm_dp_mst_topology_get_port_validated(mgr, payload->port); 3338 if (!port) { 3339 drm_dbg_kms(mgr->dev, 3340 "VCPI %d for port %p not in topology, not creating a payload to remote\n", 3341 payload->vcpi, payload->port); 3342 return -EIO; 3343 } 3344 3345 ret = drm_dp_create_payload_at_dfp(mgr, payload); 3346 if (ret < 0) { 3347 drm_dbg_kms(mgr->dev, "Failed to create MST payload for port %p: %d\n", 3348 payload->port, ret); 3349 goto put_port; 3350 } 3351 3352 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_DFP; 3353 3354put_port: 3355 drm_dp_mst_topology_put_port(port); 3356 3357 return ret; 3358} 3359EXPORT_SYMBOL(drm_dp_add_payload_part1); 3360 3361/** 3362 * drm_dp_remove_payload_part1() - Remove an MST payload along the virtual channel 3363 * @mgr: Manager to use. 3364 * @mst_state: The MST atomic state 3365 * @payload: The payload to remove 3366 * 3367 * Removes a payload along the virtual channel if it was successfully allocated. 3368 * After calling this, the driver should set HW to generate ACT and then switch to new 3369 * payload allocation state. 3370 */ 3371void drm_dp_remove_payload_part1(struct drm_dp_mst_topology_mgr *mgr, 3372 struct drm_dp_mst_topology_state *mst_state, 3373 struct drm_dp_mst_atomic_payload *payload) 3374{ 3375 /* Remove remote payload allocation */ 3376 bool send_remove = false; 3377 3378 mutex_lock(&mgr->lock); 3379 send_remove = drm_dp_mst_port_downstream_of_branch(payload->port, mgr->mst_primary); 3380 mutex_unlock(&mgr->lock); 3381 3382 if (send_remove) 3383 drm_dp_destroy_payload_at_remote_and_dfp(mgr, mst_state, payload); 3384 else 3385 drm_dbg_kms(mgr->dev, "Payload for VCPI %d not in topology, not sending remove\n", 3386 payload->vcpi); 3387 3388 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_LOCAL; 3389} 3390EXPORT_SYMBOL(drm_dp_remove_payload_part1); 3391 3392/** 3393 * drm_dp_remove_payload_part2() - Remove an MST payload locally 3394 * @mgr: Manager to use. 3395 * @mst_state: The MST atomic state 3396 * @old_payload: The payload with its old state 3397 * @new_payload: The payload with its latest state 3398 * 3399 * Updates the starting time slots of all other payloads which would have been shifted towards 3400 * the start of the payload ID table as a result of removing a payload. Driver should call this 3401 * function whenever it removes a payload in its HW. It's independent to the result of payload 3402 * allocation/deallocation at branch devices along the virtual channel. 3403 */ 3404void drm_dp_remove_payload_part2(struct drm_dp_mst_topology_mgr *mgr, 3405 struct drm_dp_mst_topology_state *mst_state, 3406 const struct drm_dp_mst_atomic_payload *old_payload, 3407 struct drm_dp_mst_atomic_payload *new_payload) 3408{ 3409 struct drm_dp_mst_atomic_payload *pos; 3410 3411 /* Remove local payload allocation */ 3412 list_for_each_entry(pos, &mst_state->payloads, next) { 3413 if (pos != new_payload && pos->vc_start_slot > new_payload->vc_start_slot) 3414 pos->vc_start_slot -= old_payload->time_slots; 3415 } 3416 new_payload->vc_start_slot = -1; 3417 3418 mgr->payload_count--; 3419 mgr->next_start_slot -= old_payload->time_slots; 3420 3421 if (new_payload->delete) 3422 drm_dp_mst_put_port_malloc(new_payload->port); 3423 3424 new_payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_NONE; 3425} 3426EXPORT_SYMBOL(drm_dp_remove_payload_part2); 3427/** 3428 * drm_dp_add_payload_part2() - Execute payload update part 2 3429 * @mgr: Manager to use. 3430 * @payload: The payload to update 3431 * 3432 * If @payload was successfully assigned a starting time slot by drm_dp_add_payload_part1(), this 3433 * function will send the sideband messages to finish allocating this payload. 3434 * 3435 * Returns: 0 on success, negative error code on failure. 3436 */ 3437int drm_dp_add_payload_part2(struct drm_dp_mst_topology_mgr *mgr, 3438 struct drm_dp_mst_atomic_payload *payload) 3439{ 3440 int ret = 0; 3441 3442 /* Skip failed payloads */ 3443 if (payload->payload_allocation_status != DRM_DP_MST_PAYLOAD_ALLOCATION_DFP) { 3444 drm_dbg_kms(mgr->dev, "Part 1 of payload creation for %s failed, skipping part 2\n", 3445 payload->port->connector->name); 3446 return -EIO; 3447 } 3448 3449 /* Allocate payload to remote end */ 3450 ret = drm_dp_create_payload_to_remote(mgr, payload); 3451 if (ret < 0) 3452 drm_err(mgr->dev, "Step 2 of creating MST payload for %p failed: %d\n", 3453 payload->port, ret); 3454 else 3455 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_REMOTE; 3456 3457 return ret; 3458} 3459EXPORT_SYMBOL(drm_dp_add_payload_part2); 3460 3461static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, 3462 struct drm_dp_mst_port *port, 3463 int offset, int size, u8 *bytes) 3464{ 3465 int ret = 0; 3466 struct drm_dp_sideband_msg_tx *txmsg; 3467 struct drm_dp_mst_branch *mstb; 3468 3469 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 3470 if (!mstb) 3471 return -EINVAL; 3472 3473 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3474 if (!txmsg) { 3475 ret = -ENOMEM; 3476 goto fail_put; 3477 } 3478 3479 build_dpcd_read(txmsg, port->port_num, offset, size); 3480 txmsg->dst = port->parent; 3481 3482 drm_dp_queue_down_tx(mgr, txmsg); 3483 3484 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3485 if (ret < 0) 3486 goto fail_free; 3487 3488 if (txmsg->reply.reply_type == 1) { 3489 drm_dbg_kms(mgr->dev, "mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n", 3490 mstb, port->port_num, offset, size); 3491 ret = -EIO; 3492 goto fail_free; 3493 } 3494 3495 if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) { 3496 ret = -EPROTO; 3497 goto fail_free; 3498 } 3499 3500 ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes, 3501 size); 3502 memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret); 3503 3504fail_free: 3505 kfree(txmsg); 3506fail_put: 3507 drm_dp_mst_topology_put_mstb(mstb); 3508 3509 return ret; 3510} 3511 3512static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, 3513 struct drm_dp_mst_port *port, 3514 int offset, int size, u8 *bytes) 3515{ 3516 int ret; 3517 struct drm_dp_sideband_msg_tx *txmsg; 3518 struct drm_dp_mst_branch *mstb; 3519 3520 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 3521 if (!mstb) 3522 return -EINVAL; 3523 3524 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3525 if (!txmsg) { 3526 ret = -ENOMEM; 3527 goto fail_put; 3528 } 3529 3530 build_dpcd_write(txmsg, port->port_num, offset, size, bytes); 3531 txmsg->dst = mstb; 3532 3533 drm_dp_queue_down_tx(mgr, txmsg); 3534 3535 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3536 if (ret > 0) { 3537 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3538 ret = -EIO; 3539 else 3540 ret = size; 3541 } 3542 3543 kfree(txmsg); 3544fail_put: 3545 drm_dp_mst_topology_put_mstb(mstb); 3546 return ret; 3547} 3548 3549static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type) 3550{ 3551 struct drm_dp_sideband_msg_reply_body reply; 3552 3553 reply.reply_type = DP_SIDEBAND_REPLY_ACK; 3554 reply.req_type = req_type; 3555 drm_dp_encode_sideband_reply(&reply, msg); 3556 return 0; 3557} 3558 3559static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr, 3560 struct drm_dp_mst_branch *mstb, 3561 int req_type, bool broadcast) 3562{ 3563 struct drm_dp_sideband_msg_tx *txmsg; 3564 3565 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3566 if (!txmsg) 3567 return -ENOMEM; 3568 3569 txmsg->dst = mstb; 3570 drm_dp_encode_up_ack_reply(txmsg, req_type); 3571 3572 mutex_lock(&mgr->qlock); 3573 /* construct a chunk from the first msg in the tx_msg queue */ 3574 process_single_tx_qlock(mgr, txmsg, true); 3575 mutex_unlock(&mgr->qlock); 3576 3577 kfree(txmsg); 3578 return 0; 3579} 3580 3581/** 3582 * drm_dp_get_vc_payload_bw - get the VC payload BW for an MTP link 3583 * @link_rate: link rate in 10kbits/s units 3584 * @link_lane_count: lane count 3585 * 3586 * Calculate the total bandwidth of a MultiStream Transport link. The returned 3587 * value is in units of PBNs/(timeslots/1 MTP). This value can be used to 3588 * convert the number of PBNs required for a given stream to the number of 3589 * timeslots this stream requires in each MTP. 3590 * 3591 * Returns the BW / timeslot value in 20.12 fixed point format. 3592 */ 3593fixed20_12 drm_dp_get_vc_payload_bw(int link_rate, int link_lane_count) 3594{ 3595 int ch_coding_efficiency = 3596 drm_dp_bw_channel_coding_efficiency(drm_dp_is_uhbr_rate(link_rate)); 3597 fixed20_12 ret; 3598 3599 /* See DP v2.0 2.6.4.2, 2.7.6.3 VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */ 3600 ret.full = DIV_ROUND_DOWN_ULL(mul_u32_u32(link_rate * link_lane_count, 3601 ch_coding_efficiency), 3602 (1000000ULL * 8 * 5400) >> 12); 3603 3604 return ret; 3605} 3606EXPORT_SYMBOL(drm_dp_get_vc_payload_bw); 3607 3608/** 3609 * drm_dp_read_mst_cap() - Read the sink's MST mode capability 3610 * @aux: The DP AUX channel to use 3611 * @dpcd: A cached copy of the DPCD capabilities for this sink 3612 * 3613 * Returns: enum drm_dp_mst_mode to indicate MST mode capability 3614 */ 3615enum drm_dp_mst_mode drm_dp_read_mst_cap(struct drm_dp_aux *aux, 3616 const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 3617{ 3618 u8 mstm_cap; 3619 3620 if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_12) 3621 return DRM_DP_SST; 3622 3623 if (drm_dp_dpcd_read_byte(aux, DP_MSTM_CAP, &mstm_cap) < 0) 3624 return DRM_DP_SST; 3625 3626 if (mstm_cap & DP_MST_CAP) 3627 return DRM_DP_MST; 3628 3629 if (mstm_cap & DP_SINGLE_STREAM_SIDEBAND_MSG) 3630 return DRM_DP_SST_SIDEBAND_MSG; 3631 3632 return DRM_DP_SST; 3633} 3634EXPORT_SYMBOL(drm_dp_read_mst_cap); 3635 3636/** 3637 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager 3638 * @mgr: manager to set state for 3639 * @mst_state: true to enable MST on this connector - false to disable. 3640 * 3641 * This is called by the driver when it detects an MST capable device plugged 3642 * into a DP MST capable port, or when a DP MST capable device is unplugged. 3643 */ 3644int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state) 3645{ 3646 int ret = 0; 3647 struct drm_dp_mst_branch *mstb = NULL; 3648 3649 mutex_lock(&mgr->lock); 3650 if (mst_state == mgr->mst_state) 3651 goto out_unlock; 3652 3653 mgr->mst_state = mst_state; 3654 /* set the device into MST mode */ 3655 if (mst_state) { 3656 WARN_ON(mgr->mst_primary); 3657 3658 /* get dpcd info */ 3659 ret = drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd); 3660 if (ret < 0) { 3661 drm_dbg_kms(mgr->dev, "%s: failed to read DPCD, ret %d\n", 3662 mgr->aux->name, ret); 3663 goto out_unlock; 3664 } 3665 3666 /* add initial branch device at LCT 1 */ 3667 mstb = drm_dp_add_mst_branch_device(1, NULL); 3668 if (mstb == NULL) { 3669 ret = -ENOMEM; 3670 goto out_unlock; 3671 } 3672 mstb->mgr = mgr; 3673 3674 /* give this the main reference */ 3675 mgr->mst_primary = mstb; 3676 drm_dp_mst_topology_get_mstb(mgr->mst_primary); 3677 3678 ret = drm_dp_dpcd_write_byte(mgr->aux, DP_MSTM_CTRL, 3679 DP_MST_EN | 3680 DP_UP_REQ_EN | 3681 DP_UPSTREAM_IS_SRC); 3682 if (ret < 0) 3683 goto out_unlock; 3684 3685 /* Write reset payload */ 3686 drm_dp_dpcd_clear_payload(mgr->aux); 3687 3688 drm_dp_mst_queue_probe_work(mgr); 3689 3690 ret = 0; 3691 } else { 3692 /* disable MST on the device */ 3693 mstb = mgr->mst_primary; 3694 mgr->mst_primary = NULL; 3695 /* this can fail if the device is gone */ 3696 drm_dp_dpcd_write_byte(mgr->aux, DP_MSTM_CTRL, 0); 3697 ret = 0; 3698 mgr->payload_id_table_cleared = false; 3699 3700 mgr->reset_rx_state = true; 3701 } 3702 3703out_unlock: 3704 mutex_unlock(&mgr->lock); 3705 if (mstb) 3706 drm_dp_mst_topology_put_mstb(mstb); 3707 return ret; 3708 3709} 3710EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst); 3711 3712static void 3713drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb) 3714{ 3715 struct drm_dp_mst_port *port; 3716 3717 /* The link address will need to be re-sent on resume */ 3718 mstb->link_address_sent = false; 3719 3720 list_for_each_entry(port, &mstb->ports, next) 3721 if (port->mstb) 3722 drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb); 3723} 3724 3725/** 3726 * drm_dp_mst_topology_queue_probe - Queue a topology probe 3727 * @mgr: manager to probe 3728 * 3729 * Queue a work to probe the MST topology. Driver's should call this only to 3730 * sync the topology's HW->SW state after the MST link's parameters have 3731 * changed in a way the state could've become out-of-sync. This is the case 3732 * for instance when the link rate between the source and first downstream 3733 * branch device has switched between UHBR and non-UHBR rates. Except of those 3734 * cases - for instance when a sink gets plugged/unplugged to a port - the SW 3735 * state will get updated automatically via MST UP message notifications. 3736 */ 3737void drm_dp_mst_topology_queue_probe(struct drm_dp_mst_topology_mgr *mgr) 3738{ 3739 mutex_lock(&mgr->lock); 3740 3741 if (drm_WARN_ON(mgr->dev, !mgr->mst_state || !mgr->mst_primary)) 3742 goto out_unlock; 3743 3744 drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary); 3745 drm_dp_mst_queue_probe_work(mgr); 3746 3747out_unlock: 3748 mutex_unlock(&mgr->lock); 3749} 3750EXPORT_SYMBOL(drm_dp_mst_topology_queue_probe); 3751 3752/** 3753 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager 3754 * @mgr: manager to suspend 3755 * 3756 * This function tells the MST device that we can't handle UP messages 3757 * anymore. This should stop it from sending any since we are suspended. 3758 */ 3759void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr) 3760{ 3761 mutex_lock(&mgr->lock); 3762 drm_dp_dpcd_write_byte(mgr->aux, DP_MSTM_CTRL, 3763 DP_MST_EN | DP_UPSTREAM_IS_SRC); 3764 mutex_unlock(&mgr->lock); 3765 flush_work(&mgr->up_req_work); 3766 flush_work(&mgr->work); 3767 flush_work(&mgr->delayed_destroy_work); 3768 3769 mutex_lock(&mgr->lock); 3770 if (mgr->mst_state && mgr->mst_primary) 3771 drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary); 3772 mutex_unlock(&mgr->lock); 3773} 3774EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend); 3775 3776/** 3777 * drm_dp_mst_topology_mgr_resume() - resume the MST manager 3778 * @mgr: manager to resume 3779 * @sync: whether or not to perform topology reprobing synchronously 3780 * 3781 * This will fetch DPCD and see if the device is still there, 3782 * if it is, it will rewrite the MSTM control bits, and return. 3783 * 3784 * If the device fails this returns -1, and the driver should do 3785 * a full MST reprobe, in case we were undocked. 3786 * 3787 * During system resume (where it is assumed that the driver will be calling 3788 * drm_atomic_helper_resume()) this function should be called beforehand with 3789 * @sync set to true. In contexts like runtime resume where the driver is not 3790 * expected to be calling drm_atomic_helper_resume(), this function should be 3791 * called with @sync set to false in order to avoid deadlocking. 3792 * 3793 * Returns: -1 if the MST topology was removed while we were suspended, 0 3794 * otherwise. 3795 */ 3796int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr, 3797 bool sync) 3798{ 3799 u8 buf[UUID_SIZE]; 3800 guid_t guid; 3801 int ret; 3802 3803 mutex_lock(&mgr->lock); 3804 if (!mgr->mst_primary) 3805 goto out_fail; 3806 3807 if (drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd) < 0) { 3808 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n"); 3809 goto out_fail; 3810 } 3811 3812 ret = drm_dp_dpcd_write_byte(mgr->aux, DP_MSTM_CTRL, 3813 DP_MST_EN | 3814 DP_UP_REQ_EN | 3815 DP_UPSTREAM_IS_SRC); 3816 if (ret < 0) { 3817 drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n"); 3818 goto out_fail; 3819 } 3820 3821 /* Some hubs forget their guids after they resume */ 3822 ret = drm_dp_dpcd_read_data(mgr->aux, DP_GUID, buf, sizeof(buf)); 3823 if (ret < 0) { 3824 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n"); 3825 goto out_fail; 3826 } 3827 3828 import_guid(&guid, buf); 3829 3830 ret = drm_dp_check_mstb_guid(mgr->mst_primary, &guid); 3831 if (ret) { 3832 drm_dbg_kms(mgr->dev, "check mstb failed - undocked during suspend?\n"); 3833 goto out_fail; 3834 } 3835 3836 /* 3837 * For the final step of resuming the topology, we need to bring the 3838 * state of our in-memory topology back into sync with reality. So, 3839 * restart the probing process as if we're probing a new hub 3840 */ 3841 drm_dp_mst_queue_probe_work(mgr); 3842 mutex_unlock(&mgr->lock); 3843 3844 if (sync) { 3845 drm_dbg_kms(mgr->dev, 3846 "Waiting for link probe work to finish re-syncing topology...\n"); 3847 flush_work(&mgr->work); 3848 } 3849 3850 return 0; 3851 3852out_fail: 3853 mutex_unlock(&mgr->lock); 3854 return -1; 3855} 3856EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume); 3857 3858static void reset_msg_rx_state(struct drm_dp_sideband_msg_rx *msg) 3859{ 3860 memset(msg, 0, sizeof(*msg)); 3861} 3862 3863static bool 3864drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up, 3865 struct drm_dp_mst_branch **mstb) 3866{ 3867 int len; 3868 u8 replyblock[32]; 3869 int replylen, curreply; 3870 int ret; 3871 u8 hdrlen; 3872 struct drm_dp_sideband_msg_hdr hdr; 3873 struct drm_dp_sideband_msg_rx *msg = 3874 up ? &mgr->up_req_recv : &mgr->down_rep_recv; 3875 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : 3876 DP_SIDEBAND_MSG_DOWN_REP_BASE; 3877 3878 if (!up) 3879 *mstb = NULL; 3880 3881 len = min(mgr->max_dpcd_transaction_bytes, 16); 3882 ret = drm_dp_dpcd_read_data(mgr->aux, basereg, replyblock, len); 3883 if (ret < 0) { 3884 drm_dbg_kms(mgr->dev, "failed to read DPCD down rep %d %d\n", len, ret); 3885 return false; 3886 } 3887 3888 ret = drm_dp_decode_sideband_msg_hdr(mgr, &hdr, replyblock, len, &hdrlen); 3889 if (ret == false) { 3890 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 3891 1, replyblock, len, false); 3892 drm_dbg_kms(mgr->dev, "ERROR: failed header\n"); 3893 return false; 3894 } 3895 3896 if (!up) { 3897 /* Caller is responsible for giving back this reference */ 3898 *mstb = drm_dp_get_mst_branch_device(mgr, hdr.lct, hdr.rad); 3899 if (!*mstb) { 3900 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr.lct); 3901 return false; 3902 } 3903 } 3904 3905 if (!drm_dp_sideband_msg_set_header(msg, &hdr, hdrlen)) { 3906 drm_dbg_kms(mgr->dev, "sideband msg set header failed %d\n", replyblock[0]); 3907 return false; 3908 } 3909 3910 replylen = min(msg->curchunk_len, (u8)(len - hdrlen)); 3911 ret = drm_dp_sideband_append_payload(msg, replyblock + hdrlen, replylen); 3912 if (!ret) { 3913 drm_dbg_kms(mgr->dev, "sideband msg build failed %d\n", replyblock[0]); 3914 return false; 3915 } 3916 3917 replylen = msg->curchunk_len + msg->curchunk_hdrlen - len; 3918 curreply = len; 3919 while (replylen > 0) { 3920 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16); 3921 ret = drm_dp_dpcd_read_data(mgr->aux, basereg + curreply, 3922 replyblock, len); 3923 if (ret < 0) { 3924 drm_dbg_kms(mgr->dev, "failed to read a chunk (len %d, ret %d)\n", 3925 len, ret); 3926 return false; 3927 } 3928 3929 ret = drm_dp_sideband_append_payload(msg, replyblock, len); 3930 if (!ret) { 3931 drm_dbg_kms(mgr->dev, "failed to build sideband msg\n"); 3932 return false; 3933 } 3934 3935 curreply += len; 3936 replylen -= len; 3937 } 3938 return true; 3939} 3940 3941static int get_msg_request_type(u8 data) 3942{ 3943 return data & 0x7f; 3944} 3945 3946static bool verify_rx_request_type(struct drm_dp_mst_topology_mgr *mgr, 3947 const struct drm_dp_sideband_msg_tx *txmsg, 3948 const struct drm_dp_sideband_msg_rx *rxmsg) 3949{ 3950 const struct drm_dp_sideband_msg_hdr *hdr = &rxmsg->initial_hdr; 3951 const struct drm_dp_mst_branch *mstb = txmsg->dst; 3952 int tx_req_type = get_msg_request_type(txmsg->msg[0]); 3953 int rx_req_type = get_msg_request_type(rxmsg->msg[0]); 3954 char rad_str[64]; 3955 3956 if (tx_req_type == rx_req_type) 3957 return true; 3958 3959 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, rad_str, sizeof(rad_str)); 3960 drm_dbg_kms(mgr->dev, 3961 "Got unexpected MST reply, mstb: %p seqno: %d lct: %d rad: %s rx_req_type: %s (%02x) != tx_req_type: %s (%02x)\n", 3962 mstb, hdr->seqno, mstb->lct, rad_str, 3963 drm_dp_mst_req_type_str(rx_req_type), rx_req_type, 3964 drm_dp_mst_req_type_str(tx_req_type), tx_req_type); 3965 3966 return false; 3967} 3968 3969static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr) 3970{ 3971 struct drm_dp_sideband_msg_tx *txmsg; 3972 struct drm_dp_mst_branch *mstb = NULL; 3973 struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv; 3974 3975 if (!drm_dp_get_one_sb_msg(mgr, false, &mstb)) 3976 goto out_clear_reply; 3977 3978 /* Multi-packet message transmission, don't clear the reply */ 3979 if (!msg->have_eomt) 3980 goto out; 3981 3982 /* find the message */ 3983 mutex_lock(&mgr->qlock); 3984 3985 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq, 3986 struct drm_dp_sideband_msg_tx, next); 3987 3988 /* Were we actually expecting a response, and from this mstb? */ 3989 if (!txmsg || txmsg->dst != mstb) { 3990 struct drm_dp_sideband_msg_hdr *hdr; 3991 3992 hdr = &msg->initial_hdr; 3993 drm_dbg_kms(mgr->dev, "Got MST reply with no msg %p %d %d %02x %02x\n", 3994 mstb, hdr->seqno, hdr->lct, hdr->rad[0], msg->msg[0]); 3995 3996 mutex_unlock(&mgr->qlock); 3997 3998 goto out_clear_reply; 3999 } 4000 4001 if (!verify_rx_request_type(mgr, txmsg, msg)) { 4002 mutex_unlock(&mgr->qlock); 4003 4004 goto out_clear_reply; 4005 } 4006 4007 drm_dp_sideband_parse_reply(mgr, msg, &txmsg->reply); 4008 4009 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 4010 drm_dbg_kms(mgr->dev, 4011 "Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n", 4012 txmsg->reply.req_type, 4013 drm_dp_mst_req_type_str(txmsg->reply.req_type), 4014 txmsg->reply.u.nak.reason, 4015 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason), 4016 txmsg->reply.u.nak.nak_data); 4017 } 4018 4019 txmsg->state = DRM_DP_SIDEBAND_TX_RX; 4020 list_del(&txmsg->next); 4021 4022 mutex_unlock(&mgr->qlock); 4023 4024 wake_up_all(&mgr->tx_waitq); 4025 4026out_clear_reply: 4027 reset_msg_rx_state(msg); 4028out: 4029 if (mstb) 4030 drm_dp_mst_topology_put_mstb(mstb); 4031 4032 return 0; 4033} 4034 4035static bool primary_mstb_probing_is_done(struct drm_dp_mst_topology_mgr *mgr) 4036{ 4037 bool probing_done = false; 4038 4039 mutex_lock(&mgr->lock); 4040 4041 if (mgr->mst_primary && drm_dp_mst_topology_try_get_mstb(mgr->mst_primary)) { 4042 probing_done = mgr->mst_primary->link_address_sent; 4043 drm_dp_mst_topology_put_mstb(mgr->mst_primary); 4044 } 4045 4046 mutex_unlock(&mgr->lock); 4047 4048 return probing_done; 4049} 4050 4051static inline bool 4052drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr, 4053 struct drm_dp_pending_up_req *up_req) 4054{ 4055 struct drm_dp_mst_branch *mstb = NULL; 4056 struct drm_dp_sideband_msg_req_body *msg = &up_req->msg; 4057 struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr; 4058 bool hotplug = false, dowork = false; 4059 4060 if (hdr->broadcast) { 4061 const guid_t *guid = NULL; 4062 4063 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) 4064 guid = &msg->u.conn_stat.guid; 4065 else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY) 4066 guid = &msg->u.resource_stat.guid; 4067 4068 if (guid) 4069 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid); 4070 } else { 4071 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad); 4072 } 4073 4074 if (!mstb) { 4075 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr->lct); 4076 return false; 4077 } 4078 4079 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */ 4080 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) { 4081 if (!primary_mstb_probing_is_done(mgr)) { 4082 drm_dbg_kms(mgr->dev, "Got CSN before finish topology probing. Skip it.\n"); 4083 } else { 4084 dowork = drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat); 4085 hotplug = true; 4086 } 4087 } 4088 4089 drm_dp_mst_topology_put_mstb(mstb); 4090 4091 if (dowork) 4092 queue_work(system_long_wq, &mgr->work); 4093 return hotplug; 4094} 4095 4096static void drm_dp_mst_up_req_work(struct work_struct *work) 4097{ 4098 struct drm_dp_mst_topology_mgr *mgr = 4099 container_of(work, struct drm_dp_mst_topology_mgr, 4100 up_req_work); 4101 struct drm_dp_pending_up_req *up_req; 4102 bool send_hotplug = false; 4103 4104 mutex_lock(&mgr->probe_lock); 4105 while (true) { 4106 mutex_lock(&mgr->up_req_lock); 4107 up_req = list_first_entry_or_null(&mgr->up_req_list, 4108 struct drm_dp_pending_up_req, 4109 next); 4110 if (up_req) 4111 list_del(&up_req->next); 4112 mutex_unlock(&mgr->up_req_lock); 4113 4114 if (!up_req) 4115 break; 4116 4117 send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req); 4118 kfree(up_req); 4119 } 4120 mutex_unlock(&mgr->probe_lock); 4121 4122 if (send_hotplug) 4123 drm_kms_helper_hotplug_event(mgr->dev); 4124} 4125 4126static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr) 4127{ 4128 struct drm_dp_pending_up_req *up_req; 4129 struct drm_dp_mst_branch *mst_primary; 4130 int ret = 0; 4131 4132 if (!drm_dp_get_one_sb_msg(mgr, true, NULL)) 4133 goto out_clear_reply; 4134 4135 if (!mgr->up_req_recv.have_eomt) 4136 return 0; 4137 4138 up_req = kzalloc(sizeof(*up_req), GFP_KERNEL); 4139 if (!up_req) { 4140 ret = -ENOMEM; 4141 goto out_clear_reply; 4142 } 4143 4144 INIT_LIST_HEAD(&up_req->next); 4145 4146 drm_dp_sideband_parse_req(mgr, &mgr->up_req_recv, &up_req->msg); 4147 4148 if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY && 4149 up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) { 4150 drm_dbg_kms(mgr->dev, "Received unknown up req type, ignoring: %x\n", 4151 up_req->msg.req_type); 4152 kfree(up_req); 4153 goto out_clear_reply; 4154 } 4155 4156 mutex_lock(&mgr->lock); 4157 mst_primary = mgr->mst_primary; 4158 if (!mst_primary || !drm_dp_mst_topology_try_get_mstb(mst_primary)) { 4159 mutex_unlock(&mgr->lock); 4160 kfree(up_req); 4161 goto out_clear_reply; 4162 } 4163 mutex_unlock(&mgr->lock); 4164 4165 drm_dp_send_up_ack_reply(mgr, mst_primary, up_req->msg.req_type, 4166 false); 4167 4168 drm_dp_mst_topology_put_mstb(mst_primary); 4169 4170 if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) { 4171 const struct drm_dp_connection_status_notify *conn_stat = 4172 &up_req->msg.u.conn_stat; 4173 4174 drm_dbg_kms(mgr->dev, "Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", 4175 conn_stat->port_number, 4176 conn_stat->legacy_device_plug_status, 4177 conn_stat->displayport_device_plug_status, 4178 conn_stat->message_capability_status, 4179 conn_stat->input_port, 4180 conn_stat->peer_device_type); 4181 } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) { 4182 const struct drm_dp_resource_status_notify *res_stat = 4183 &up_req->msg.u.resource_stat; 4184 4185 drm_dbg_kms(mgr->dev, "Got RSN: pn: %d avail_pbn %d\n", 4186 res_stat->port_number, 4187 res_stat->available_pbn); 4188 } 4189 4190 up_req->hdr = mgr->up_req_recv.initial_hdr; 4191 mutex_lock(&mgr->up_req_lock); 4192 list_add_tail(&up_req->next, &mgr->up_req_list); 4193 mutex_unlock(&mgr->up_req_lock); 4194 queue_work(system_long_wq, &mgr->up_req_work); 4195out_clear_reply: 4196 reset_msg_rx_state(&mgr->up_req_recv); 4197 return ret; 4198} 4199 4200static void update_msg_rx_state(struct drm_dp_mst_topology_mgr *mgr) 4201{ 4202 mutex_lock(&mgr->lock); 4203 if (mgr->reset_rx_state) { 4204 mgr->reset_rx_state = false; 4205 reset_msg_rx_state(&mgr->down_rep_recv); 4206 reset_msg_rx_state(&mgr->up_req_recv); 4207 } 4208 mutex_unlock(&mgr->lock); 4209} 4210 4211/** 4212 * drm_dp_mst_hpd_irq_handle_event() - MST hotplug IRQ handle MST event 4213 * @mgr: manager to notify irq for. 4214 * @esi: 4 bytes from SINK_COUNT_ESI 4215 * @ack: 4 bytes used to ack events starting from SINK_COUNT_ESI 4216 * @handled: whether the hpd interrupt was consumed or not 4217 * 4218 * This should be called from the driver when it detects a HPD IRQ, 4219 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The 4220 * topology manager will process the sideband messages received 4221 * as indicated in the DEVICE_SERVICE_IRQ_VECTOR_ESI0 and set the 4222 * corresponding flags that Driver has to ack the DP receiver later. 4223 * 4224 * Note that driver shall also call 4225 * drm_dp_mst_hpd_irq_send_new_request() if the 'handled' is set 4226 * after calling this function, to try to kick off a new request in 4227 * the queue if the previous message transaction is completed. 4228 * 4229 * See also: 4230 * drm_dp_mst_hpd_irq_send_new_request() 4231 */ 4232int drm_dp_mst_hpd_irq_handle_event(struct drm_dp_mst_topology_mgr *mgr, const u8 *esi, 4233 u8 *ack, bool *handled) 4234{ 4235 int ret = 0; 4236 int sc; 4237 *handled = false; 4238 sc = DP_GET_SINK_COUNT(esi[0]); 4239 4240 if (sc != mgr->sink_count) { 4241 mgr->sink_count = sc; 4242 *handled = true; 4243 } 4244 4245 update_msg_rx_state(mgr); 4246 4247 if (esi[1] & DP_DOWN_REP_MSG_RDY) { 4248 ret = drm_dp_mst_handle_down_rep(mgr); 4249 *handled = true; 4250 ack[1] |= DP_DOWN_REP_MSG_RDY; 4251 } 4252 4253 if (esi[1] & DP_UP_REQ_MSG_RDY) { 4254 ret |= drm_dp_mst_handle_up_req(mgr); 4255 *handled = true; 4256 ack[1] |= DP_UP_REQ_MSG_RDY; 4257 } 4258 4259 return ret; 4260} 4261EXPORT_SYMBOL(drm_dp_mst_hpd_irq_handle_event); 4262 4263/** 4264 * drm_dp_mst_hpd_irq_send_new_request() - MST hotplug IRQ kick off new request 4265 * @mgr: manager to notify irq for. 4266 * 4267 * This should be called from the driver when mst irq event is handled 4268 * and acked. Note that new down request should only be sent when 4269 * previous message transaction is completed. Source is not supposed to generate 4270 * interleaved message transactions. 4271 */ 4272void drm_dp_mst_hpd_irq_send_new_request(struct drm_dp_mst_topology_mgr *mgr) 4273{ 4274 struct drm_dp_sideband_msg_tx *txmsg; 4275 bool kick = true; 4276 4277 mutex_lock(&mgr->qlock); 4278 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq, 4279 struct drm_dp_sideband_msg_tx, next); 4280 /* If last transaction is not completed yet*/ 4281 if (!txmsg || 4282 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND || 4283 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) 4284 kick = false; 4285 mutex_unlock(&mgr->qlock); 4286 4287 if (kick) 4288 drm_dp_mst_kick_tx(mgr); 4289} 4290EXPORT_SYMBOL(drm_dp_mst_hpd_irq_send_new_request); 4291/** 4292 * drm_dp_mst_detect_port() - get connection status for an MST port 4293 * @connector: DRM connector for this port 4294 * @ctx: The acquisition context to use for grabbing locks 4295 * @mgr: manager for this port 4296 * @port: pointer to a port 4297 * 4298 * This returns the current connection state for a port. 4299 */ 4300int 4301drm_dp_mst_detect_port(struct drm_connector *connector, 4302 struct drm_modeset_acquire_ctx *ctx, 4303 struct drm_dp_mst_topology_mgr *mgr, 4304 struct drm_dp_mst_port *port) 4305{ 4306 int ret; 4307 4308 /* we need to search for the port in the mgr in case it's gone */ 4309 port = drm_dp_mst_topology_get_port_validated(mgr, port); 4310 if (!port) 4311 return connector_status_disconnected; 4312 4313 ret = drm_modeset_lock(&mgr->base.lock, ctx); 4314 if (ret) 4315 goto out; 4316 4317 ret = connector_status_disconnected; 4318 4319 if (!port->ddps) 4320 goto out; 4321 4322 switch (port->pdt) { 4323 case DP_PEER_DEVICE_NONE: 4324 break; 4325 case DP_PEER_DEVICE_MST_BRANCHING: 4326 if (!port->mcs) 4327 ret = connector_status_connected; 4328 break; 4329 4330 case DP_PEER_DEVICE_SST_SINK: 4331 ret = connector_status_connected; 4332 /* for logical ports - cache the EDID */ 4333 if (drm_dp_mst_port_is_logical(port) && !port->cached_edid) 4334 port->cached_edid = drm_edid_read_ddc(connector, &port->aux.ddc); 4335 break; 4336 case DP_PEER_DEVICE_DP_LEGACY_CONV: 4337 if (port->ldps) 4338 ret = connector_status_connected; 4339 break; 4340 } 4341out: 4342 drm_dp_mst_topology_put_port(port); 4343 return ret; 4344} 4345EXPORT_SYMBOL(drm_dp_mst_detect_port); 4346 4347/** 4348 * drm_dp_mst_edid_read() - get EDID for an MST port 4349 * @connector: toplevel connector to get EDID for 4350 * @mgr: manager for this port 4351 * @port: unverified pointer to a port. 4352 * 4353 * This returns an EDID for the port connected to a connector, 4354 * It validates the pointer still exists so the caller doesn't require a 4355 * reference. 4356 */ 4357const struct drm_edid *drm_dp_mst_edid_read(struct drm_connector *connector, 4358 struct drm_dp_mst_topology_mgr *mgr, 4359 struct drm_dp_mst_port *port) 4360{ 4361 const struct drm_edid *drm_edid; 4362 4363 /* we need to search for the port in the mgr in case it's gone */ 4364 port = drm_dp_mst_topology_get_port_validated(mgr, port); 4365 if (!port) 4366 return NULL; 4367 4368 if (port->cached_edid) 4369 drm_edid = drm_edid_dup(port->cached_edid); 4370 else 4371 drm_edid = drm_edid_read_ddc(connector, &port->aux.ddc); 4372 4373 drm_dp_mst_topology_put_port(port); 4374 4375 return drm_edid; 4376} 4377EXPORT_SYMBOL(drm_dp_mst_edid_read); 4378 4379/** 4380 * drm_dp_mst_get_edid() - get EDID for an MST port 4381 * @connector: toplevel connector to get EDID for 4382 * @mgr: manager for this port 4383 * @port: unverified pointer to a port. 4384 * 4385 * This function is deprecated; please use drm_dp_mst_edid_read() instead. 4386 * 4387 * This returns an EDID for the port connected to a connector, 4388 * It validates the pointer still exists so the caller doesn't require a 4389 * reference. 4390 */ 4391struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, 4392 struct drm_dp_mst_topology_mgr *mgr, 4393 struct drm_dp_mst_port *port) 4394{ 4395 const struct drm_edid *drm_edid; 4396 struct edid *edid; 4397 4398 drm_edid = drm_dp_mst_edid_read(connector, mgr, port); 4399 4400 edid = drm_edid_duplicate(drm_edid_raw(drm_edid)); 4401 4402 drm_edid_free(drm_edid); 4403 4404 return edid; 4405} 4406EXPORT_SYMBOL(drm_dp_mst_get_edid); 4407 4408/** 4409 * drm_dp_atomic_find_time_slots() - Find and add time slots to the state 4410 * @state: global atomic state 4411 * @mgr: MST topology manager for the port 4412 * @port: port to find time slots for 4413 * @pbn: bandwidth required for the mode in PBN 4414 * 4415 * Allocates time slots to @port, replacing any previous time slot allocations it may 4416 * have had. Any atomic drivers which support MST must call this function in 4417 * their &drm_encoder_helper_funcs.atomic_check() callback unconditionally to 4418 * change the current time slot allocation for the new state, and ensure the MST 4419 * atomic state is added whenever the state of payloads in the topology changes. 4420 * 4421 * Allocations set by this function are not checked against the bandwidth 4422 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check(). 4423 * 4424 * Additionally, it is OK to call this function multiple times on the same 4425 * @port as needed. It is not OK however, to call this function and 4426 * drm_dp_atomic_release_time_slots() in the same atomic check phase. 4427 * 4428 * See also: 4429 * drm_dp_atomic_release_time_slots() 4430 * drm_dp_mst_atomic_check() 4431 * 4432 * Returns: 4433 * Total slots in the atomic state assigned for this port, or a negative error 4434 * code if the port no longer exists 4435 */ 4436int drm_dp_atomic_find_time_slots(struct drm_atomic_state *state, 4437 struct drm_dp_mst_topology_mgr *mgr, 4438 struct drm_dp_mst_port *port, int pbn) 4439{ 4440 struct drm_dp_mst_topology_state *topology_state; 4441 struct drm_dp_mst_atomic_payload *payload = NULL; 4442 struct drm_connector_state *conn_state; 4443 int prev_slots = 0, prev_bw = 0, req_slots; 4444 4445 topology_state = drm_atomic_get_mst_topology_state(state, mgr); 4446 if (IS_ERR(topology_state)) 4447 return PTR_ERR(topology_state); 4448 4449 conn_state = drm_atomic_get_new_connector_state(state, port->connector); 4450 topology_state->pending_crtc_mask |= drm_crtc_mask(conn_state->crtc); 4451 4452 /* Find the current allocation for this port, if any */ 4453 payload = drm_atomic_get_mst_payload_state(topology_state, port); 4454 if (payload) { 4455 prev_slots = payload->time_slots; 4456 prev_bw = payload->pbn; 4457 4458 /* 4459 * This should never happen, unless the driver tries 4460 * releasing and allocating the same timeslot allocation, 4461 * which is an error 4462 */ 4463 if (drm_WARN_ON(mgr->dev, payload->delete)) { 4464 drm_err(mgr->dev, 4465 "cannot allocate and release time slots on [MST PORT:%p] in the same state\n", 4466 port); 4467 return -EINVAL; 4468 } 4469 } 4470 4471 req_slots = DIV_ROUND_UP(dfixed_const(pbn), topology_state->pbn_div.full); 4472 4473 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] TU %d -> %d\n", 4474 port->connector->base.id, port->connector->name, 4475 port, prev_slots, req_slots); 4476 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n", 4477 port->connector->base.id, port->connector->name, 4478 port, prev_bw, pbn); 4479 4480 /* Add the new allocation to the state, note the VCPI isn't assigned until the end */ 4481 if (!payload) { 4482 payload = kzalloc(sizeof(*payload), GFP_KERNEL); 4483 if (!payload) 4484 return -ENOMEM; 4485 4486 drm_dp_mst_get_port_malloc(port); 4487 payload->port = port; 4488 payload->vc_start_slot = -1; 4489 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_NONE; 4490 list_add(&payload->next, &topology_state->payloads); 4491 } 4492 payload->time_slots = req_slots; 4493 payload->pbn = pbn; 4494 4495 return req_slots; 4496} 4497EXPORT_SYMBOL(drm_dp_atomic_find_time_slots); 4498 4499/** 4500 * drm_dp_atomic_release_time_slots() - Release allocated time slots 4501 * @state: global atomic state 4502 * @mgr: MST topology manager for the port 4503 * @port: The port to release the time slots from 4504 * 4505 * Releases any time slots that have been allocated to a port in the atomic 4506 * state. Any atomic drivers which support MST must call this function 4507 * unconditionally in their &drm_connector_helper_funcs.atomic_check() callback. 4508 * This helper will check whether time slots would be released by the new state and 4509 * respond accordingly, along with ensuring the MST state is always added to the 4510 * atomic state whenever a new state would modify the state of payloads on the 4511 * topology. 4512 * 4513 * It is OK to call this even if @port has been removed from the system. 4514 * Additionally, it is OK to call this function multiple times on the same 4515 * @port as needed. It is not OK however, to call this function and 4516 * drm_dp_atomic_find_time_slots() on the same @port in a single atomic check 4517 * phase. 4518 * 4519 * See also: 4520 * drm_dp_atomic_find_time_slots() 4521 * drm_dp_mst_atomic_check() 4522 * 4523 * Returns: 4524 * 0 on success, negative error code otherwise 4525 */ 4526int drm_dp_atomic_release_time_slots(struct drm_atomic_state *state, 4527 struct drm_dp_mst_topology_mgr *mgr, 4528 struct drm_dp_mst_port *port) 4529{ 4530 struct drm_dp_mst_topology_state *topology_state; 4531 struct drm_dp_mst_atomic_payload *payload; 4532 struct drm_connector_state *old_conn_state, *new_conn_state; 4533 bool update_payload = true; 4534 4535 old_conn_state = drm_atomic_get_old_connector_state(state, port->connector); 4536 if (!old_conn_state->crtc) 4537 return 0; 4538 4539 /* If the CRTC isn't disabled by this state, don't release it's payload */ 4540 new_conn_state = drm_atomic_get_new_connector_state(state, port->connector); 4541 if (new_conn_state->crtc) { 4542 struct drm_crtc_state *crtc_state = 4543 drm_atomic_get_new_crtc_state(state, new_conn_state->crtc); 4544 4545 /* No modeset means no payload changes, so it's safe to not pull in the MST state */ 4546 if (!crtc_state || !drm_atomic_crtc_needs_modeset(crtc_state)) 4547 return 0; 4548 4549 if (!crtc_state->mode_changed && !crtc_state->connectors_changed) 4550 update_payload = false; 4551 } 4552 4553 topology_state = drm_atomic_get_mst_topology_state(state, mgr); 4554 if (IS_ERR(topology_state)) 4555 return PTR_ERR(topology_state); 4556 4557 topology_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc); 4558 if (!update_payload) 4559 return 0; 4560 4561 payload = drm_atomic_get_mst_payload_state(topology_state, port); 4562 if (WARN_ON(!payload)) { 4563 drm_err(mgr->dev, "No payload for [MST PORT:%p] found in mst state %p\n", 4564 port, &topology_state->base); 4565 return -EINVAL; 4566 } 4567 4568 if (new_conn_state->crtc) 4569 return 0; 4570 4571 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] TU %d -> 0\n", port, payload->time_slots); 4572 if (!payload->delete) { 4573 payload->pbn = 0; 4574 payload->delete = true; 4575 if (payload->vcpi > 0) 4576 topology_state->payload_mask &= ~BIT(payload->vcpi - 1); 4577 } 4578 4579 return 0; 4580} 4581EXPORT_SYMBOL(drm_dp_atomic_release_time_slots); 4582 4583/** 4584 * drm_dp_mst_atomic_setup_commit() - setup_commit hook for MST helpers 4585 * @state: global atomic state 4586 * 4587 * This function saves all of the &drm_crtc_commit structs in an atomic state that touch any CRTCs 4588 * currently assigned to an MST topology. Drivers must call this hook from their 4589 * &drm_mode_config_helper_funcs.atomic_commit_setup hook. 4590 * 4591 * Returns: 4592 * 0 if all CRTC commits were retrieved successfully, negative error code otherwise 4593 */ 4594int drm_dp_mst_atomic_setup_commit(struct drm_atomic_state *state) 4595{ 4596 struct drm_dp_mst_topology_mgr *mgr; 4597 struct drm_dp_mst_topology_state *mst_state; 4598 struct drm_crtc *crtc; 4599 struct drm_crtc_state *crtc_state; 4600 int i, j, commit_idx, num_commit_deps; 4601 4602 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { 4603 if (!mst_state->pending_crtc_mask) 4604 continue; 4605 4606 num_commit_deps = hweight32(mst_state->pending_crtc_mask); 4607 mst_state->commit_deps = kmalloc_array(num_commit_deps, 4608 sizeof(*mst_state->commit_deps), GFP_KERNEL); 4609 if (!mst_state->commit_deps) 4610 return -ENOMEM; 4611 mst_state->num_commit_deps = num_commit_deps; 4612 4613 commit_idx = 0; 4614 for_each_new_crtc_in_state(state, crtc, crtc_state, j) { 4615 if (mst_state->pending_crtc_mask & drm_crtc_mask(crtc)) { 4616 mst_state->commit_deps[commit_idx++] = 4617 drm_crtc_commit_get(crtc_state->commit); 4618 } 4619 } 4620 } 4621 4622 return 0; 4623} 4624EXPORT_SYMBOL(drm_dp_mst_atomic_setup_commit); 4625 4626/** 4627 * drm_dp_mst_atomic_wait_for_dependencies() - Wait for all pending commits on MST topologies, 4628 * prepare new MST state for commit 4629 * @state: global atomic state 4630 * 4631 * Goes through any MST topologies in this atomic state, and waits for any pending commits which 4632 * touched CRTCs that were/are on an MST topology to be programmed to hardware and flipped to before 4633 * returning. This is to prevent multiple non-blocking commits affecting an MST topology from racing 4634 * with eachother by forcing them to be executed sequentially in situations where the only resources 4635 * the modeset objects in these commits share are an MST topology. 4636 * 4637 * This function also prepares the new MST state for commit by performing some state preparation 4638 * which can't be done until this point, such as reading back the final VC start slots (which are 4639 * determined at commit-time) from the previous state. 4640 * 4641 * All MST drivers must call this function after calling drm_atomic_helper_wait_for_dependencies(), 4642 * or whatever their equivalent of that is. 4643 */ 4644void drm_dp_mst_atomic_wait_for_dependencies(struct drm_atomic_state *state) 4645{ 4646 struct drm_dp_mst_topology_state *old_mst_state, *new_mst_state; 4647 struct drm_dp_mst_topology_mgr *mgr; 4648 struct drm_dp_mst_atomic_payload *old_payload, *new_payload; 4649 int i, j, ret; 4650 4651 for_each_oldnew_mst_mgr_in_state(state, mgr, old_mst_state, new_mst_state, i) { 4652 for (j = 0; j < old_mst_state->num_commit_deps; j++) { 4653 ret = drm_crtc_commit_wait(old_mst_state->commit_deps[j]); 4654 if (ret < 0) 4655 drm_err(state->dev, "Failed to wait for %s: %d\n", 4656 old_mst_state->commit_deps[j]->crtc->name, ret); 4657 } 4658 4659 /* Now that previous state is committed, it's safe to copy over the start slot 4660 * and allocation status assignments 4661 */ 4662 list_for_each_entry(old_payload, &old_mst_state->payloads, next) { 4663 if (old_payload->delete) 4664 continue; 4665 4666 new_payload = drm_atomic_get_mst_payload_state(new_mst_state, 4667 old_payload->port); 4668 new_payload->vc_start_slot = old_payload->vc_start_slot; 4669 new_payload->payload_allocation_status = 4670 old_payload->payload_allocation_status; 4671 } 4672 } 4673} 4674EXPORT_SYMBOL(drm_dp_mst_atomic_wait_for_dependencies); 4675 4676/** 4677 * drm_dp_mst_root_conn_atomic_check() - Serialize CRTC commits on MST-capable connectors operating 4678 * in SST mode 4679 * @new_conn_state: The new connector state of the &drm_connector 4680 * @mgr: The MST topology manager for the &drm_connector 4681 * 4682 * Since MST uses fake &drm_encoder structs, the generic atomic modesetting code isn't able to 4683 * serialize non-blocking commits happening on the real DP connector of an MST topology switching 4684 * into/away from MST mode - as the CRTC on the real DP connector and the CRTCs on the connector's 4685 * MST topology will never share the same &drm_encoder. 4686 * 4687 * This function takes care of this serialization issue, by checking a root MST connector's atomic 4688 * state to determine if it is about to have a modeset - and then pulling in the MST topology state 4689 * if so, along with adding any relevant CRTCs to &drm_dp_mst_topology_state.pending_crtc_mask. 4690 * 4691 * Drivers implementing MST must call this function from the 4692 * &drm_connector_helper_funcs.atomic_check hook of any physical DP &drm_connector capable of 4693 * driving MST sinks. 4694 * 4695 * Returns: 4696 * 0 on success, negative error code otherwise 4697 */ 4698int drm_dp_mst_root_conn_atomic_check(struct drm_connector_state *new_conn_state, 4699 struct drm_dp_mst_topology_mgr *mgr) 4700{ 4701 struct drm_atomic_state *state = new_conn_state->state; 4702 struct drm_connector_state *old_conn_state = 4703 drm_atomic_get_old_connector_state(state, new_conn_state->connector); 4704 struct drm_crtc_state *crtc_state; 4705 struct drm_dp_mst_topology_state *mst_state = NULL; 4706 4707 if (new_conn_state->crtc) { 4708 crtc_state = drm_atomic_get_new_crtc_state(state, new_conn_state->crtc); 4709 if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) { 4710 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 4711 if (IS_ERR(mst_state)) 4712 return PTR_ERR(mst_state); 4713 4714 mst_state->pending_crtc_mask |= drm_crtc_mask(new_conn_state->crtc); 4715 } 4716 } 4717 4718 if (old_conn_state->crtc) { 4719 crtc_state = drm_atomic_get_new_crtc_state(state, old_conn_state->crtc); 4720 if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) { 4721 if (!mst_state) { 4722 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 4723 if (IS_ERR(mst_state)) 4724 return PTR_ERR(mst_state); 4725 } 4726 4727 mst_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc); 4728 } 4729 } 4730 4731 return 0; 4732} 4733EXPORT_SYMBOL(drm_dp_mst_root_conn_atomic_check); 4734 4735/** 4736 * drm_dp_mst_update_slots() - updates the slot info depending on the DP ecoding format 4737 * @mst_state: mst_state to update 4738 * @link_encoding_cap: the ecoding format on the link 4739 */ 4740void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap) 4741{ 4742 if (link_encoding_cap == DP_CAP_ANSI_128B132B) { 4743 mst_state->total_avail_slots = 64; 4744 mst_state->start_slot = 0; 4745 } else { 4746 mst_state->total_avail_slots = 63; 4747 mst_state->start_slot = 1; 4748 } 4749 4750 DRM_DEBUG_KMS("%s encoding format on mst_state 0x%p\n", 4751 (link_encoding_cap == DP_CAP_ANSI_128B132B) ? "128b/132b":"8b/10b", 4752 mst_state); 4753} 4754EXPORT_SYMBOL(drm_dp_mst_update_slots); 4755 4756/** 4757 * drm_dp_check_act_status() - Polls for ACT handled status. 4758 * @mgr: manager to use 4759 * 4760 * Tries waiting for the MST hub to finish updating it's payload table by 4761 * polling for the ACT handled bit for up to 3 seconds (yes-some hubs really 4762 * take that long). 4763 * 4764 * Returns: 4765 * 0 if the ACT was handled in time, negative error code on failure. 4766 */ 4767int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr) 4768{ 4769 /* 4770 * There doesn't seem to be any recommended retry count or timeout in 4771 * the MST specification. Since some hubs have been observed to take 4772 * over 1 second to update their payload allocations under certain 4773 * conditions, we use a rather large timeout value of 3 seconds. 4774 */ 4775 return drm_dp_dpcd_poll_act_handled(mgr->aux, 3000); 4776} 4777EXPORT_SYMBOL(drm_dp_check_act_status); 4778 4779/** 4780 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode. 4781 * @clock: dot clock 4782 * @bpp: bpp as .4 binary fixed point 4783 * 4784 * This uses the formula in the spec to calculate the PBN value for a mode. 4785 */ 4786int drm_dp_calc_pbn_mode(int clock, int bpp) 4787{ 4788 /* 4789 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on 4790 * common multiplier to render an integer PBN for all link rate/lane 4791 * counts combinations 4792 * calculate 4793 * peak_kbps = clock * bpp / 16 4794 * peak_kbps *= SSC overhead / 1000000 4795 * peak_kbps /= 8 convert to Kbytes 4796 * peak_kBps *= (64/54) / 1000 convert to PBN 4797 */ 4798 /* 4799 * TODO: Use the actual link and mode parameters to calculate 4800 * the overhead. For now it's assumed that these are 4801 * 4 link lanes, 4096 hactive pixels, which don't add any 4802 * significant data padding overhead and that there is no DSC 4803 * or FEC overhead. 4804 */ 4805 int overhead = drm_dp_bw_overhead(4, 4096, 0, bpp, 4806 DRM_DP_BW_OVERHEAD_MST | 4807 DRM_DP_BW_OVERHEAD_SSC_REF_CLK); 4808 4809 return DIV64_U64_ROUND_UP(mul_u32_u32(clock * bpp, 64 * overhead >> 4), 4810 1000000ULL * 8 * 54 * 1000); 4811} 4812EXPORT_SYMBOL(drm_dp_calc_pbn_mode); 4813 4814/* we want to kick the TX after we've ack the up/down IRQs. */ 4815static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr) 4816{ 4817 queue_work(system_long_wq, &mgr->tx_work); 4818} 4819 4820/* 4821 * Helper function for parsing DP device types into convenient strings 4822 * for use with dp_mst_topology 4823 */ 4824static const char *pdt_to_string(u8 pdt) 4825{ 4826 switch (pdt) { 4827 case DP_PEER_DEVICE_NONE: 4828 return "NONE"; 4829 case DP_PEER_DEVICE_SOURCE_OR_SST: 4830 return "SOURCE OR SST"; 4831 case DP_PEER_DEVICE_MST_BRANCHING: 4832 return "MST BRANCHING"; 4833 case DP_PEER_DEVICE_SST_SINK: 4834 return "SST SINK"; 4835 case DP_PEER_DEVICE_DP_LEGACY_CONV: 4836 return "DP LEGACY CONV"; 4837 default: 4838 return "ERR"; 4839 } 4840} 4841 4842static void drm_dp_mst_dump_mstb(struct seq_file *m, 4843 struct drm_dp_mst_branch *mstb) 4844{ 4845 struct drm_dp_mst_port *port; 4846 int tabs = mstb->lct; 4847 char prefix[10]; 4848 int i; 4849 4850 for (i = 0; i < tabs; i++) 4851 prefix[i] = '\t'; 4852 prefix[i] = '\0'; 4853 4854 seq_printf(m, "%smstb - [%p]: num_ports: %d\n", prefix, mstb, mstb->num_ports); 4855 list_for_each_entry(port, &mstb->ports, next) { 4856 seq_printf(m, "%sport %d - [%p] (%s - %s): ddps: %d, ldps: %d, sdp: %d/%d, fec: %s, conn: %p\n", 4857 prefix, 4858 port->port_num, 4859 port, 4860 port->input ? "input" : "output", 4861 pdt_to_string(port->pdt), 4862 port->ddps, 4863 port->ldps, 4864 port->num_sdp_streams, 4865 port->num_sdp_stream_sinks, 4866 port->fec_capable ? "true" : "false", 4867 port->connector); 4868 if (port->mstb) 4869 drm_dp_mst_dump_mstb(m, port->mstb); 4870 } 4871} 4872 4873#define DP_PAYLOAD_TABLE_SIZE 64 4874 4875static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, 4876 char *buf) 4877{ 4878 int i; 4879 4880 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) { 4881 if (drm_dp_dpcd_read_data(mgr->aux, 4882 DP_PAYLOAD_TABLE_UPDATE_STATUS + i, 4883 &buf[i], 16) < 0) 4884 return false; 4885 } 4886 return true; 4887} 4888 4889static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr, 4890 struct drm_dp_mst_port *port, char *name, 4891 int namelen) 4892{ 4893 struct edid *mst_edid; 4894 4895 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port); 4896 drm_edid_get_monitor_name(mst_edid, name, namelen); 4897 kfree(mst_edid); 4898} 4899 4900/** 4901 * drm_dp_mst_dump_topology(): dump topology to seq file. 4902 * @m: seq_file to dump output to 4903 * @mgr: manager to dump current topology for. 4904 * 4905 * helper to dump MST topology to a seq file for debugfs. 4906 */ 4907void drm_dp_mst_dump_topology(struct seq_file *m, 4908 struct drm_dp_mst_topology_mgr *mgr) 4909{ 4910 struct drm_dp_mst_topology_state *state; 4911 struct drm_dp_mst_atomic_payload *payload; 4912 int i, ret; 4913 4914 static const char *const status[] = { 4915 "None", 4916 "Local", 4917 "DFP", 4918 "Remote", 4919 }; 4920 4921 mutex_lock(&mgr->lock); 4922 if (mgr->mst_primary) 4923 drm_dp_mst_dump_mstb(m, mgr->mst_primary); 4924 4925 /* dump VCPIs */ 4926 mutex_unlock(&mgr->lock); 4927 4928 ret = drm_modeset_lock_single_interruptible(&mgr->base.lock); 4929 if (ret < 0) 4930 return; 4931 4932 state = to_drm_dp_mst_topology_state(mgr->base.state); 4933 seq_printf(m, "\n*** Atomic state info ***\n"); 4934 seq_printf(m, "payload_mask: %x, max_payloads: %d, start_slot: %u, pbn_div: %d\n", 4935 state->payload_mask, mgr->max_payloads, state->start_slot, 4936 dfixed_trunc(state->pbn_div)); 4937 4938 seq_printf(m, "\n| idx | port | vcpi | slots | pbn | dsc | status | sink name |\n"); 4939 for (i = 0; i < mgr->max_payloads; i++) { 4940 list_for_each_entry(payload, &state->payloads, next) { 4941 char name[14]; 4942 4943 if (payload->vcpi != i || payload->delete) 4944 continue; 4945 4946 fetch_monitor_name(mgr, payload->port, name, sizeof(name)); 4947 seq_printf(m, " %5d %6d %6d %02d - %02d %5d %5s %8s %19s\n", 4948 i, 4949 payload->port->port_num, 4950 payload->vcpi, 4951 payload->vc_start_slot, 4952 payload->vc_start_slot + payload->time_slots - 1, 4953 payload->pbn, 4954 payload->dsc_enabled ? "Y" : "N", 4955 status[payload->payload_allocation_status], 4956 (*name != 0) ? name : "Unknown"); 4957 } 4958 } 4959 4960 seq_printf(m, "\n*** DPCD Info ***\n"); 4961 mutex_lock(&mgr->lock); 4962 if (mgr->mst_primary) { 4963 u8 buf[DP_PAYLOAD_TABLE_SIZE]; 4964 int ret; 4965 4966 if (drm_dp_read_dpcd_caps(mgr->aux, buf) < 0) { 4967 seq_printf(m, "dpcd read failed\n"); 4968 goto out; 4969 } 4970 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf); 4971 4972 ret = drm_dp_dpcd_read_data(mgr->aux, DP_FAUX_CAP, buf, 2); 4973 if (ret < 0) { 4974 seq_printf(m, "faux/mst read failed\n"); 4975 goto out; 4976 } 4977 seq_printf(m, "faux/mst: %*ph\n", 2, buf); 4978 4979 ret = drm_dp_dpcd_read_data(mgr->aux, DP_MSTM_CTRL, buf, 1); 4980 if (ret < 0) { 4981 seq_printf(m, "mst ctrl read failed\n"); 4982 goto out; 4983 } 4984 seq_printf(m, "mst ctrl: %*ph\n", 1, buf); 4985 4986 /* dump the standard OUI branch header */ 4987 ret = drm_dp_dpcd_read_data(mgr->aux, DP_BRANCH_OUI, buf, 4988 DP_BRANCH_OUI_HEADER_SIZE); 4989 if (ret < 0) { 4990 seq_printf(m, "branch oui read failed\n"); 4991 goto out; 4992 } 4993 seq_printf(m, "branch oui: %*phN devid: ", 3, buf); 4994 4995 for (i = 0x3; i < 0x8 && buf[i]; i++) 4996 seq_putc(m, buf[i]); 4997 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n", 4998 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]); 4999 if (dump_dp_payload_table(mgr, buf)) 5000 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf); 5001 } 5002 5003out: 5004 mutex_unlock(&mgr->lock); 5005 drm_modeset_unlock(&mgr->base.lock); 5006} 5007EXPORT_SYMBOL(drm_dp_mst_dump_topology); 5008 5009static void drm_dp_tx_work(struct work_struct *work) 5010{ 5011 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work); 5012 5013 mutex_lock(&mgr->qlock); 5014 if (!list_empty(&mgr->tx_msg_downq)) 5015 process_single_down_tx_qlock(mgr); 5016 mutex_unlock(&mgr->qlock); 5017} 5018 5019static inline void 5020drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port) 5021{ 5022 drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs); 5023 5024 if (port->connector) { 5025 drm_connector_unregister(port->connector); 5026 drm_connector_put(port->connector); 5027 } 5028 5029 drm_dp_mst_put_port_malloc(port); 5030} 5031 5032static inline void 5033drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb) 5034{ 5035 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 5036 struct drm_dp_mst_port *port, *port_tmp; 5037 struct drm_dp_sideband_msg_tx *txmsg, *txmsg_tmp; 5038 bool wake_tx = false; 5039 5040 mutex_lock(&mgr->lock); 5041 list_for_each_entry_safe(port, port_tmp, &mstb->ports, next) { 5042 list_del(&port->next); 5043 drm_dp_mst_topology_put_port(port); 5044 } 5045 mutex_unlock(&mgr->lock); 5046 5047 /* drop any tx slot msg */ 5048 mutex_lock(&mstb->mgr->qlock); 5049 list_for_each_entry_safe(txmsg, txmsg_tmp, &mgr->tx_msg_downq, next) { 5050 if (txmsg->dst != mstb) 5051 continue; 5052 5053 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 5054 list_del(&txmsg->next); 5055 wake_tx = true; 5056 } 5057 mutex_unlock(&mstb->mgr->qlock); 5058 5059 if (wake_tx) 5060 wake_up_all(&mstb->mgr->tx_waitq); 5061 5062 drm_dp_mst_put_mstb_malloc(mstb); 5063} 5064 5065static void drm_dp_delayed_destroy_work(struct work_struct *work) 5066{ 5067 struct drm_dp_mst_topology_mgr *mgr = 5068 container_of(work, struct drm_dp_mst_topology_mgr, 5069 delayed_destroy_work); 5070 bool send_hotplug = false, go_again; 5071 5072 /* 5073 * Not a regular list traverse as we have to drop the destroy 5074 * connector lock before destroying the mstb/port, to avoid AB->BA 5075 * ordering between this lock and the config mutex. 5076 */ 5077 do { 5078 go_again = false; 5079 5080 for (;;) { 5081 struct drm_dp_mst_branch *mstb; 5082 5083 mutex_lock(&mgr->delayed_destroy_lock); 5084 mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list, 5085 struct drm_dp_mst_branch, 5086 destroy_next); 5087 if (mstb) 5088 list_del(&mstb->destroy_next); 5089 mutex_unlock(&mgr->delayed_destroy_lock); 5090 5091 if (!mstb) 5092 break; 5093 5094 drm_dp_delayed_destroy_mstb(mstb); 5095 go_again = true; 5096 } 5097 5098 for (;;) { 5099 struct drm_dp_mst_port *port; 5100 5101 mutex_lock(&mgr->delayed_destroy_lock); 5102 port = list_first_entry_or_null(&mgr->destroy_port_list, 5103 struct drm_dp_mst_port, 5104 next); 5105 if (port) 5106 list_del(&port->next); 5107 mutex_unlock(&mgr->delayed_destroy_lock); 5108 5109 if (!port) 5110 break; 5111 5112 drm_dp_delayed_destroy_port(port); 5113 send_hotplug = true; 5114 go_again = true; 5115 } 5116 } while (go_again); 5117 5118 if (send_hotplug) 5119 drm_kms_helper_hotplug_event(mgr->dev); 5120} 5121 5122static struct drm_private_state * 5123drm_dp_mst_duplicate_state(struct drm_private_obj *obj) 5124{ 5125 struct drm_dp_mst_topology_state *state, *old_state = 5126 to_dp_mst_topology_state(obj->state); 5127 struct drm_dp_mst_atomic_payload *pos, *payload; 5128 5129 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL); 5130 if (!state) 5131 return NULL; 5132 5133 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base); 5134 5135 INIT_LIST_HEAD(&state->payloads); 5136 state->commit_deps = NULL; 5137 state->num_commit_deps = 0; 5138 state->pending_crtc_mask = 0; 5139 5140 list_for_each_entry(pos, &old_state->payloads, next) { 5141 /* Prune leftover freed timeslot allocations */ 5142 if (pos->delete) 5143 continue; 5144 5145 payload = kmemdup(pos, sizeof(*payload), GFP_KERNEL); 5146 if (!payload) 5147 goto fail; 5148 5149 drm_dp_mst_get_port_malloc(payload->port); 5150 list_add(&payload->next, &state->payloads); 5151 } 5152 5153 return &state->base; 5154 5155fail: 5156 list_for_each_entry_safe(pos, payload, &state->payloads, next) { 5157 drm_dp_mst_put_port_malloc(pos->port); 5158 kfree(pos); 5159 } 5160 kfree(state); 5161 5162 return NULL; 5163} 5164 5165static void drm_dp_mst_destroy_state(struct drm_private_obj *obj, 5166 struct drm_private_state *state) 5167{ 5168 struct drm_dp_mst_topology_state *mst_state = 5169 to_dp_mst_topology_state(state); 5170 struct drm_dp_mst_atomic_payload *pos, *tmp; 5171 int i; 5172 5173 list_for_each_entry_safe(pos, tmp, &mst_state->payloads, next) { 5174 /* We only keep references to ports with active payloads */ 5175 if (!pos->delete) 5176 drm_dp_mst_put_port_malloc(pos->port); 5177 kfree(pos); 5178 } 5179 5180 for (i = 0; i < mst_state->num_commit_deps; i++) 5181 drm_crtc_commit_put(mst_state->commit_deps[i]); 5182 5183 kfree(mst_state->commit_deps); 5184 kfree(mst_state); 5185} 5186 5187static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port, 5188 struct drm_dp_mst_branch *branch) 5189{ 5190 while (port->parent) { 5191 if (port->parent == branch) 5192 return true; 5193 5194 if (port->parent->port_parent) 5195 port = port->parent->port_parent; 5196 else 5197 break; 5198 } 5199 return false; 5200} 5201 5202static bool 5203drm_dp_mst_port_downstream_of_parent_locked(struct drm_dp_mst_topology_mgr *mgr, 5204 struct drm_dp_mst_port *port, 5205 struct drm_dp_mst_port *parent) 5206{ 5207 if (!mgr->mst_primary) 5208 return false; 5209 5210 port = drm_dp_mst_topology_get_port_validated_locked(mgr->mst_primary, 5211 port); 5212 if (!port) 5213 return false; 5214 5215 if (!parent) 5216 return true; 5217 5218 parent = drm_dp_mst_topology_get_port_validated_locked(mgr->mst_primary, 5219 parent); 5220 if (!parent) 5221 return false; 5222 5223 if (!parent->mstb) 5224 return false; 5225 5226 return drm_dp_mst_port_downstream_of_branch(port, parent->mstb); 5227} 5228 5229/** 5230 * drm_dp_mst_port_downstream_of_parent - check if a port is downstream of a parent port 5231 * @mgr: MST topology manager 5232 * @port: the port being looked up 5233 * @parent: the parent port 5234 * 5235 * The function returns %true if @port is downstream of @parent. If @parent is 5236 * %NULL - denoting the root port - the function returns %true if @port is in 5237 * @mgr's topology. 5238 */ 5239bool 5240drm_dp_mst_port_downstream_of_parent(struct drm_dp_mst_topology_mgr *mgr, 5241 struct drm_dp_mst_port *port, 5242 struct drm_dp_mst_port *parent) 5243{ 5244 bool ret; 5245 5246 mutex_lock(&mgr->lock); 5247 ret = drm_dp_mst_port_downstream_of_parent_locked(mgr, port, parent); 5248 mutex_unlock(&mgr->lock); 5249 5250 return ret; 5251} 5252EXPORT_SYMBOL(drm_dp_mst_port_downstream_of_parent); 5253 5254static int 5255drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, 5256 struct drm_dp_mst_topology_state *state, 5257 struct drm_dp_mst_port **failing_port); 5258 5259static int 5260drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb, 5261 struct drm_dp_mst_topology_state *state, 5262 struct drm_dp_mst_port **failing_port) 5263{ 5264 struct drm_dp_mst_atomic_payload *payload; 5265 struct drm_dp_mst_port *port; 5266 int pbn_used = 0, ret; 5267 bool found = false; 5268 5269 /* Check that we have at least one port in our state that's downstream 5270 * of this branch, otherwise we can skip this branch 5271 */ 5272 list_for_each_entry(payload, &state->payloads, next) { 5273 if (!payload->pbn || 5274 !drm_dp_mst_port_downstream_of_branch(payload->port, mstb)) 5275 continue; 5276 5277 found = true; 5278 break; 5279 } 5280 if (!found) 5281 return 0; 5282 5283 if (mstb->port_parent) 5284 drm_dbg_atomic(mstb->mgr->dev, 5285 "[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n", 5286 mstb->port_parent->parent, mstb->port_parent, mstb); 5287 else 5288 drm_dbg_atomic(mstb->mgr->dev, "[MSTB:%p] Checking bandwidth limits\n", mstb); 5289 5290 list_for_each_entry(port, &mstb->ports, next) { 5291 ret = drm_dp_mst_atomic_check_port_bw_limit(port, state, failing_port); 5292 if (ret < 0) 5293 return ret; 5294 5295 pbn_used += ret; 5296 } 5297 5298 return pbn_used; 5299} 5300 5301static int 5302drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, 5303 struct drm_dp_mst_topology_state *state, 5304 struct drm_dp_mst_port **failing_port) 5305{ 5306 struct drm_dp_mst_atomic_payload *payload; 5307 int pbn_used = 0; 5308 5309 if (port->pdt == DP_PEER_DEVICE_NONE) 5310 return 0; 5311 5312 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { 5313 payload = drm_atomic_get_mst_payload_state(state, port); 5314 if (!payload) 5315 return 0; 5316 5317 /* 5318 * This could happen if the sink deasserted its HPD line, but 5319 * the branch device still reports it as attached (PDT != NONE). 5320 */ 5321 if (!port->full_pbn) { 5322 drm_dbg_atomic(port->mgr->dev, 5323 "[MSTB:%p] [MST PORT:%p] no BW available for the port\n", 5324 port->parent, port); 5325 *failing_port = port; 5326 return -EINVAL; 5327 } 5328 5329 pbn_used = payload->pbn; 5330 } else { 5331 pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb, 5332 state, 5333 failing_port); 5334 if (pbn_used <= 0) 5335 return pbn_used; 5336 } 5337 5338 if (pbn_used > port->full_pbn) { 5339 drm_dbg_atomic(port->mgr->dev, 5340 "[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n", 5341 port->parent, port, pbn_used, port->full_pbn); 5342 *failing_port = port; 5343 return -ENOSPC; 5344 } 5345 5346 drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n", 5347 port->parent, port, pbn_used, port->full_pbn); 5348 5349 return pbn_used; 5350} 5351 5352static inline int 5353drm_dp_mst_atomic_check_payload_alloc_limits(struct drm_dp_mst_topology_mgr *mgr, 5354 struct drm_dp_mst_topology_state *mst_state) 5355{ 5356 struct drm_dp_mst_atomic_payload *payload; 5357 int avail_slots = mst_state->total_avail_slots, payload_count = 0; 5358 5359 list_for_each_entry(payload, &mst_state->payloads, next) { 5360 /* Releasing payloads is always OK-even if the port is gone */ 5361 if (payload->delete) { 5362 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] releases all time slots\n", 5363 payload->port); 5364 continue; 5365 } 5366 5367 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] requires %d time slots\n", 5368 payload->port, payload->time_slots); 5369 5370 avail_slots -= payload->time_slots; 5371 if (avail_slots < 0) { 5372 drm_dbg_atomic(mgr->dev, 5373 "[MST PORT:%p] not enough time slots in mst state %p (avail=%d)\n", 5374 payload->port, mst_state, avail_slots + payload->time_slots); 5375 return -ENOSPC; 5376 } 5377 5378 if (++payload_count > mgr->max_payloads) { 5379 drm_dbg_atomic(mgr->dev, 5380 "[MST MGR:%p] state %p has too many payloads (max=%d)\n", 5381 mgr, mst_state, mgr->max_payloads); 5382 return -EINVAL; 5383 } 5384 5385 /* Assign a VCPI */ 5386 if (!payload->vcpi) { 5387 payload->vcpi = ffz(mst_state->payload_mask) + 1; 5388 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] assigned VCPI #%d\n", 5389 payload->port, payload->vcpi); 5390 mst_state->payload_mask |= BIT(payload->vcpi - 1); 5391 } 5392 } 5393 5394 if (!payload_count) 5395 mst_state->pbn_div.full = dfixed_const(0); 5396 5397 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] mst state %p TU pbn_div=%d avail=%d used=%d\n", 5398 mgr, mst_state, dfixed_trunc(mst_state->pbn_div), avail_slots, 5399 mst_state->total_avail_slots - avail_slots); 5400 5401 return 0; 5402} 5403 5404/** 5405 * drm_dp_mst_add_affected_dsc_crtcs 5406 * @state: Pointer to the new struct drm_dp_mst_topology_state 5407 * @mgr: MST topology manager 5408 * 5409 * Whenever there is a change in mst topology 5410 * DSC configuration would have to be recalculated 5411 * therefore we need to trigger modeset on all affected 5412 * CRTCs in that topology 5413 * 5414 * See also: 5415 * drm_dp_mst_atomic_enable_dsc() 5416 */ 5417int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr) 5418{ 5419 struct drm_dp_mst_topology_state *mst_state; 5420 struct drm_dp_mst_atomic_payload *pos; 5421 struct drm_connector *connector; 5422 struct drm_connector_state *conn_state; 5423 struct drm_crtc *crtc; 5424 struct drm_crtc_state *crtc_state; 5425 5426 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 5427 5428 if (IS_ERR(mst_state)) 5429 return PTR_ERR(mst_state); 5430 5431 list_for_each_entry(pos, &mst_state->payloads, next) { 5432 5433 connector = pos->port->connector; 5434 5435 if (!connector) 5436 return -EINVAL; 5437 5438 conn_state = drm_atomic_get_connector_state(state, connector); 5439 5440 if (IS_ERR(conn_state)) 5441 return PTR_ERR(conn_state); 5442 5443 crtc = conn_state->crtc; 5444 5445 if (!crtc) 5446 continue; 5447 5448 if (!drm_dp_mst_dsc_aux_for_port(pos->port)) 5449 continue; 5450 5451 crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc); 5452 5453 if (IS_ERR(crtc_state)) 5454 return PTR_ERR(crtc_state); 5455 5456 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] Setting mode_changed flag on CRTC %p\n", 5457 mgr, crtc); 5458 5459 crtc_state->mode_changed = true; 5460 } 5461 return 0; 5462} 5463EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs); 5464 5465/** 5466 * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off 5467 * @state: Pointer to the new drm_atomic_state 5468 * @port: Pointer to the affected MST Port 5469 * @pbn: Newly recalculated bw required for link with DSC enabled 5470 * @enable: Boolean flag to enable or disable DSC on the port 5471 * 5472 * This function enables DSC on the given Port 5473 * by recalculating its vcpi from pbn provided 5474 * and sets dsc_enable flag to keep track of which 5475 * ports have DSC enabled 5476 * 5477 */ 5478int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state, 5479 struct drm_dp_mst_port *port, 5480 int pbn, bool enable) 5481{ 5482 struct drm_dp_mst_topology_state *mst_state; 5483 struct drm_dp_mst_atomic_payload *payload; 5484 int time_slots = 0; 5485 5486 mst_state = drm_atomic_get_mst_topology_state(state, port->mgr); 5487 if (IS_ERR(mst_state)) 5488 return PTR_ERR(mst_state); 5489 5490 payload = drm_atomic_get_mst_payload_state(mst_state, port); 5491 if (!payload) { 5492 drm_dbg_atomic(state->dev, 5493 "[MST PORT:%p] Couldn't find payload in mst state %p\n", 5494 port, mst_state); 5495 return -EINVAL; 5496 } 5497 5498 if (payload->dsc_enabled == enable) { 5499 drm_dbg_atomic(state->dev, 5500 "[MST PORT:%p] DSC flag is already set to %d, returning %d time slots\n", 5501 port, enable, payload->time_slots); 5502 time_slots = payload->time_slots; 5503 } 5504 5505 if (enable) { 5506 time_slots = drm_dp_atomic_find_time_slots(state, port->mgr, port, pbn); 5507 drm_dbg_atomic(state->dev, 5508 "[MST PORT:%p] Enabling DSC flag, reallocating %d time slots on the port\n", 5509 port, time_slots); 5510 if (time_slots < 0) 5511 return -EINVAL; 5512 } 5513 5514 payload->dsc_enabled = enable; 5515 5516 return time_slots; 5517} 5518EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc); 5519 5520/** 5521 * drm_dp_mst_atomic_check_mgr - Check the atomic state of an MST topology manager 5522 * @state: The global atomic state 5523 * @mgr: Manager to check 5524 * @mst_state: The MST atomic state for @mgr 5525 * @failing_port: Returns the port with a BW limitation 5526 * 5527 * Checks the given MST manager's topology state for an atomic update to ensure 5528 * that it's valid. This includes checking whether there's enough bandwidth to 5529 * support the new timeslot allocations in the atomic update. 5530 * 5531 * Any atomic drivers supporting DP MST must make sure to call this or 5532 * the drm_dp_mst_atomic_check() function after checking the rest of their state 5533 * in their &drm_mode_config_funcs.atomic_check() callback. 5534 * 5535 * See also: 5536 * drm_dp_mst_atomic_check() 5537 * drm_dp_atomic_find_time_slots() 5538 * drm_dp_atomic_release_time_slots() 5539 * 5540 * Returns: 5541 * - 0 if the new state is valid 5542 * - %-ENOSPC, if the new state is invalid, because of BW limitation 5543 * @failing_port is set to: 5544 * 5545 * - The non-root port where a BW limit check failed 5546 * with all the ports downstream of @failing_port passing 5547 * the BW limit check. 5548 * The returned port pointer is valid until at least 5549 * one payload downstream of it exists. 5550 * - %NULL if the BW limit check failed at the root port 5551 * with all the ports downstream of the root port passing 5552 * the BW limit check. 5553 * 5554 * - %-EINVAL, if the new state is invalid, because the root port has 5555 * too many payloads. 5556 */ 5557int drm_dp_mst_atomic_check_mgr(struct drm_atomic_state *state, 5558 struct drm_dp_mst_topology_mgr *mgr, 5559 struct drm_dp_mst_topology_state *mst_state, 5560 struct drm_dp_mst_port **failing_port) 5561{ 5562 int ret; 5563 5564 *failing_port = NULL; 5565 5566 if (!mgr->mst_state) 5567 return 0; 5568 5569 mutex_lock(&mgr->lock); 5570 ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary, 5571 mst_state, 5572 failing_port); 5573 mutex_unlock(&mgr->lock); 5574 5575 if (ret < 0) 5576 return ret; 5577 5578 return drm_dp_mst_atomic_check_payload_alloc_limits(mgr, mst_state); 5579} 5580EXPORT_SYMBOL(drm_dp_mst_atomic_check_mgr); 5581 5582/** 5583 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an 5584 * atomic update is valid 5585 * @state: Pointer to the new &struct drm_dp_mst_topology_state 5586 * 5587 * Checks the given topology state for an atomic update to ensure that it's 5588 * valid, calling drm_dp_mst_atomic_check_mgr() for all MST manager in the 5589 * atomic state. This includes checking whether there's enough bandwidth to 5590 * support the new timeslot allocations in the atomic update. 5591 * 5592 * Any atomic drivers supporting DP MST must make sure to call this after 5593 * checking the rest of their state in their 5594 * &drm_mode_config_funcs.atomic_check() callback. 5595 * 5596 * See also: 5597 * drm_dp_mst_atomic_check_mgr() 5598 * drm_dp_atomic_find_time_slots() 5599 * drm_dp_atomic_release_time_slots() 5600 * 5601 * Returns: 5602 * 0 if the new state is valid, negative error code otherwise. 5603 */ 5604int drm_dp_mst_atomic_check(struct drm_atomic_state *state) 5605{ 5606 struct drm_dp_mst_topology_mgr *mgr; 5607 struct drm_dp_mst_topology_state *mst_state; 5608 int i, ret = 0; 5609 5610 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { 5611 struct drm_dp_mst_port *tmp_port; 5612 5613 ret = drm_dp_mst_atomic_check_mgr(state, mgr, mst_state, &tmp_port); 5614 if (ret) 5615 break; 5616 } 5617 5618 return ret; 5619} 5620EXPORT_SYMBOL(drm_dp_mst_atomic_check); 5621 5622const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = { 5623 .atomic_duplicate_state = drm_dp_mst_duplicate_state, 5624 .atomic_destroy_state = drm_dp_mst_destroy_state, 5625}; 5626EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs); 5627 5628/** 5629 * drm_atomic_get_mst_topology_state: get MST topology state 5630 * @state: global atomic state 5631 * @mgr: MST topology manager, also the private object in this case 5632 * 5633 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic 5634 * state vtable so that the private object state returned is that of a MST 5635 * topology object. 5636 * 5637 * RETURNS: 5638 * The MST topology state or error pointer. 5639 */ 5640struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state, 5641 struct drm_dp_mst_topology_mgr *mgr) 5642{ 5643 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base)); 5644} 5645EXPORT_SYMBOL(drm_atomic_get_mst_topology_state); 5646 5647/** 5648 * drm_atomic_get_old_mst_topology_state: get old MST topology state in atomic state, if any 5649 * @state: global atomic state 5650 * @mgr: MST topology manager, also the private object in this case 5651 * 5652 * This function wraps drm_atomic_get_old_private_obj_state() passing in the MST atomic 5653 * state vtable so that the private object state returned is that of a MST 5654 * topology object. 5655 * 5656 * Returns: 5657 * The old MST topology state, or NULL if there's no topology state for this MST mgr 5658 * in the global atomic state 5659 */ 5660struct drm_dp_mst_topology_state * 5661drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state, 5662 struct drm_dp_mst_topology_mgr *mgr) 5663{ 5664 struct drm_private_state *old_priv_state = 5665 drm_atomic_get_old_private_obj_state(state, &mgr->base); 5666 5667 return old_priv_state ? to_dp_mst_topology_state(old_priv_state) : NULL; 5668} 5669EXPORT_SYMBOL(drm_atomic_get_old_mst_topology_state); 5670 5671/** 5672 * drm_atomic_get_new_mst_topology_state: get new MST topology state in atomic state, if any 5673 * @state: global atomic state 5674 * @mgr: MST topology manager, also the private object in this case 5675 * 5676 * This function wraps drm_atomic_get_new_private_obj_state() passing in the MST atomic 5677 * state vtable so that the private object state returned is that of a MST 5678 * topology object. 5679 * 5680 * Returns: 5681 * The new MST topology state, or NULL if there's no topology state for this MST mgr 5682 * in the global atomic state 5683 */ 5684struct drm_dp_mst_topology_state * 5685drm_atomic_get_new_mst_topology_state(struct drm_atomic_state *state, 5686 struct drm_dp_mst_topology_mgr *mgr) 5687{ 5688 struct drm_private_state *new_priv_state = 5689 drm_atomic_get_new_private_obj_state(state, &mgr->base); 5690 5691 return new_priv_state ? to_dp_mst_topology_state(new_priv_state) : NULL; 5692} 5693EXPORT_SYMBOL(drm_atomic_get_new_mst_topology_state); 5694 5695/** 5696 * drm_dp_mst_topology_mgr_init - initialise a topology manager 5697 * @mgr: manager struct to initialise 5698 * @dev: device providing this structure - for i2c addition. 5699 * @aux: DP helper aux channel to talk to this device 5700 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit 5701 * @max_payloads: maximum number of payloads this GPU can source 5702 * @conn_base_id: the connector object ID the MST device is connected to. 5703 * 5704 * Return 0 for success, or negative error code on failure 5705 */ 5706int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, 5707 struct drm_device *dev, struct drm_dp_aux *aux, 5708 int max_dpcd_transaction_bytes, int max_payloads, 5709 int conn_base_id) 5710{ 5711 struct drm_dp_mst_topology_state *mst_state; 5712 5713 mutex_init(&mgr->lock); 5714 mutex_init(&mgr->qlock); 5715 mutex_init(&mgr->delayed_destroy_lock); 5716 mutex_init(&mgr->up_req_lock); 5717 mutex_init(&mgr->probe_lock); 5718#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 5719 mutex_init(&mgr->topology_ref_history_lock); 5720 stack_depot_init(); 5721#endif 5722 INIT_LIST_HEAD(&mgr->tx_msg_downq); 5723 INIT_LIST_HEAD(&mgr->destroy_port_list); 5724 INIT_LIST_HEAD(&mgr->destroy_branch_device_list); 5725 INIT_LIST_HEAD(&mgr->up_req_list); 5726 5727 /* 5728 * delayed_destroy_work will be queued on a dedicated WQ, so that any 5729 * requeuing will be also flushed when deiniting the topology manager. 5730 */ 5731 mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0); 5732 if (mgr->delayed_destroy_wq == NULL) 5733 return -ENOMEM; 5734 5735 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work); 5736 INIT_WORK(&mgr->tx_work, drm_dp_tx_work); 5737 INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work); 5738 INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work); 5739 init_waitqueue_head(&mgr->tx_waitq); 5740 mgr->dev = dev; 5741 mgr->aux = aux; 5742 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes; 5743 mgr->max_payloads = max_payloads; 5744 mgr->conn_base_id = conn_base_id; 5745 5746 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL); 5747 if (mst_state == NULL) 5748 return -ENOMEM; 5749 5750 mst_state->total_avail_slots = 63; 5751 mst_state->start_slot = 1; 5752 5753 mst_state->mgr = mgr; 5754 INIT_LIST_HEAD(&mst_state->payloads); 5755 5756 drm_atomic_private_obj_init(dev, &mgr->base, 5757 &mst_state->base, 5758 &drm_dp_mst_topology_state_funcs); 5759 5760 return 0; 5761} 5762EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init); 5763 5764/** 5765 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager. 5766 * @mgr: manager to destroy 5767 */ 5768void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr) 5769{ 5770 drm_dp_mst_topology_mgr_set_mst(mgr, false); 5771 flush_work(&mgr->work); 5772 /* The following will also drain any requeued work on the WQ. */ 5773 if (mgr->delayed_destroy_wq) { 5774 destroy_workqueue(mgr->delayed_destroy_wq); 5775 mgr->delayed_destroy_wq = NULL; 5776 } 5777 mgr->dev = NULL; 5778 mgr->aux = NULL; 5779 drm_atomic_private_obj_fini(&mgr->base); 5780 mgr->funcs = NULL; 5781 5782 mutex_destroy(&mgr->delayed_destroy_lock); 5783 mutex_destroy(&mgr->qlock); 5784 mutex_destroy(&mgr->lock); 5785 mutex_destroy(&mgr->up_req_lock); 5786 mutex_destroy(&mgr->probe_lock); 5787#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 5788 mutex_destroy(&mgr->topology_ref_history_lock); 5789#endif 5790} 5791EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy); 5792 5793static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num) 5794{ 5795 int i; 5796 5797 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS) 5798 return false; 5799 5800 for (i = 0; i < num - 1; i++) { 5801 if (msgs[i].flags & I2C_M_RD || 5802 msgs[i].len > 0xff) 5803 return false; 5804 } 5805 5806 return msgs[num - 1].flags & I2C_M_RD && 5807 msgs[num - 1].len <= 0xff; 5808} 5809 5810static bool remote_i2c_write_ok(const struct i2c_msg msgs[], int num) 5811{ 5812 int i; 5813 5814 for (i = 0; i < num - 1; i++) { 5815 if (msgs[i].flags & I2C_M_RD || !(msgs[i].flags & I2C_M_STOP) || 5816 msgs[i].len > 0xff) 5817 return false; 5818 } 5819 5820 return !(msgs[num - 1].flags & I2C_M_RD) && msgs[num - 1].len <= 0xff; 5821} 5822 5823static int drm_dp_mst_i2c_read(struct drm_dp_mst_branch *mstb, 5824 struct drm_dp_mst_port *port, 5825 struct i2c_msg *msgs, int num) 5826{ 5827 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5828 unsigned int i; 5829 struct drm_dp_sideband_msg_req_body msg; 5830 struct drm_dp_sideband_msg_tx *txmsg = NULL; 5831 int ret; 5832 5833 memset(&msg, 0, sizeof(msg)); 5834 msg.req_type = DP_REMOTE_I2C_READ; 5835 msg.u.i2c_read.num_transactions = num - 1; 5836 msg.u.i2c_read.port_number = port->port_num; 5837 for (i = 0; i < num - 1; i++) { 5838 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr; 5839 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len; 5840 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf; 5841 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP); 5842 } 5843 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr; 5844 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len; 5845 5846 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 5847 if (!txmsg) { 5848 ret = -ENOMEM; 5849 goto out; 5850 } 5851 5852 txmsg->dst = mstb; 5853 drm_dp_encode_sideband_req(&msg, txmsg); 5854 5855 drm_dp_queue_down_tx(mgr, txmsg); 5856 5857 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 5858 if (ret > 0) { 5859 5860 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 5861 ret = -EREMOTEIO; 5862 goto out; 5863 } 5864 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) { 5865 ret = -EIO; 5866 goto out; 5867 } 5868 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len); 5869 ret = num; 5870 } 5871out: 5872 kfree(txmsg); 5873 return ret; 5874} 5875 5876static int drm_dp_mst_i2c_write(struct drm_dp_mst_branch *mstb, 5877 struct drm_dp_mst_port *port, 5878 struct i2c_msg *msgs, int num) 5879{ 5880 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5881 unsigned int i; 5882 struct drm_dp_sideband_msg_req_body msg; 5883 struct drm_dp_sideband_msg_tx *txmsg = NULL; 5884 int ret; 5885 5886 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 5887 if (!txmsg) { 5888 ret = -ENOMEM; 5889 goto out; 5890 } 5891 for (i = 0; i < num; i++) { 5892 memset(&msg, 0, sizeof(msg)); 5893 msg.req_type = DP_REMOTE_I2C_WRITE; 5894 msg.u.i2c_write.port_number = port->port_num; 5895 msg.u.i2c_write.write_i2c_device_id = msgs[i].addr; 5896 msg.u.i2c_write.num_bytes = msgs[i].len; 5897 msg.u.i2c_write.bytes = msgs[i].buf; 5898 5899 memset(txmsg, 0, sizeof(*txmsg)); 5900 txmsg->dst = mstb; 5901 5902 drm_dp_encode_sideband_req(&msg, txmsg); 5903 drm_dp_queue_down_tx(mgr, txmsg); 5904 5905 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 5906 if (ret > 0) { 5907 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 5908 ret = -EREMOTEIO; 5909 goto out; 5910 } 5911 } else { 5912 goto out; 5913 } 5914 } 5915 ret = num; 5916out: 5917 kfree(txmsg); 5918 return ret; 5919} 5920 5921/* I2C device */ 5922static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, 5923 struct i2c_msg *msgs, int num) 5924{ 5925 struct drm_dp_aux *aux = adapter->algo_data; 5926 struct drm_dp_mst_port *port = 5927 container_of(aux, struct drm_dp_mst_port, aux); 5928 struct drm_dp_mst_branch *mstb; 5929 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5930 int ret; 5931 5932 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 5933 if (!mstb) 5934 return -EREMOTEIO; 5935 5936 if (remote_i2c_read_ok(msgs, num)) { 5937 ret = drm_dp_mst_i2c_read(mstb, port, msgs, num); 5938 } else if (remote_i2c_write_ok(msgs, num)) { 5939 ret = drm_dp_mst_i2c_write(mstb, port, msgs, num); 5940 } else { 5941 drm_dbg_kms(mgr->dev, "Unsupported I2C transaction for MST device\n"); 5942 ret = -EIO; 5943 } 5944 5945 drm_dp_mst_topology_put_mstb(mstb); 5946 return ret; 5947} 5948 5949static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter) 5950{ 5951 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | 5952 I2C_FUNC_SMBUS_READ_BLOCK_DATA | 5953 I2C_FUNC_SMBUS_BLOCK_PROC_CALL | 5954 I2C_FUNC_10BIT_ADDR; 5955} 5956 5957static const struct i2c_algorithm drm_dp_mst_i2c_algo = { 5958 .functionality = drm_dp_mst_i2c_functionality, 5959 .master_xfer = drm_dp_mst_i2c_xfer, 5960}; 5961 5962/** 5963 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX 5964 * @port: The port to add the I2C bus on 5965 * 5966 * Returns 0 on success or a negative error code on failure. 5967 */ 5968static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port) 5969{ 5970 struct drm_dp_aux *aux = &port->aux; 5971 struct device *parent_dev = port->mgr->dev->dev; 5972 5973 aux->ddc.algo = &drm_dp_mst_i2c_algo; 5974 aux->ddc.algo_data = aux; 5975 aux->ddc.retries = 3; 5976 5977 aux->ddc.owner = THIS_MODULE; 5978 /* FIXME: set the kdev of the port's connector as parent */ 5979 aux->ddc.dev.parent = parent_dev; 5980 aux->ddc.dev.of_node = parent_dev->of_node; 5981 5982 strscpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev), 5983 sizeof(aux->ddc.name)); 5984 5985 return i2c_add_adapter(&aux->ddc); 5986} 5987 5988/** 5989 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter 5990 * @port: The port to remove the I2C bus from 5991 */ 5992static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port) 5993{ 5994 i2c_del_adapter(&port->aux.ddc); 5995} 5996 5997/** 5998 * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device 5999 * @port: The port to check 6000 * 6001 * A single physical MST hub object can be represented in the topology 6002 * by multiple branches, with virtual ports between those branches. 6003 * 6004 * As of DP1.4, An MST hub with internal (virtual) ports must expose 6005 * certain DPCD registers over those ports. See sections 2.6.1.1.1 6006 * and 2.6.1.1.2 of Display Port specification v1.4 for details. 6007 * 6008 * May acquire mgr->lock 6009 * 6010 * Returns: 6011 * true if the port is a virtual DP peer device, false otherwise 6012 */ 6013static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port) 6014{ 6015 struct drm_dp_mst_port *downstream_port; 6016 6017 if (!port || port->dpcd_rev < DP_DPCD_REV_14) 6018 return false; 6019 6020 /* Virtual DP Sink (Internal Display Panel) */ 6021 if (drm_dp_mst_port_is_logical(port)) 6022 return true; 6023 6024 /* DP-to-HDMI Protocol Converter */ 6025 if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV && 6026 !port->mcs && 6027 port->ldps) 6028 return true; 6029 6030 /* DP-to-DP */ 6031 mutex_lock(&port->mgr->lock); 6032 if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING && 6033 port->mstb && 6034 port->mstb->num_ports == 2) { 6035 list_for_each_entry(downstream_port, &port->mstb->ports, next) { 6036 if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK && 6037 !downstream_port->input) { 6038 mutex_unlock(&port->mgr->lock); 6039 return true; 6040 } 6041 } 6042 } 6043 mutex_unlock(&port->mgr->lock); 6044 6045 return false; 6046} 6047 6048/** 6049 * drm_dp_mst_aux_for_parent() - Get the AUX device for an MST port's parent 6050 * @port: MST port whose parent's AUX device is returned 6051 * 6052 * Return the AUX device for @port's parent or NULL if port's parent is the 6053 * root port. 6054 */ 6055struct drm_dp_aux *drm_dp_mst_aux_for_parent(struct drm_dp_mst_port *port) 6056{ 6057 if (!port->parent || !port->parent->port_parent) 6058 return NULL; 6059 6060 return &port->parent->port_parent->aux; 6061} 6062EXPORT_SYMBOL(drm_dp_mst_aux_for_parent); 6063 6064/** 6065 * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC 6066 * @port: The port to check. A leaf of the MST tree with an attached display. 6067 * 6068 * Depending on the situation, DSC may be enabled via the endpoint aux, 6069 * the immediately upstream aux, or the connector's physical aux. 6070 * 6071 * This is both the correct aux to read DSC_CAPABILITY and the 6072 * correct aux to write DSC_ENABLED. 6073 * 6074 * This operation can be expensive (up to four aux reads), so 6075 * the caller should cache the return. 6076 * 6077 * Returns: 6078 * NULL if DSC cannot be enabled on this port, otherwise the aux device 6079 */ 6080struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port) 6081{ 6082 struct drm_dp_mst_port *immediate_upstream_port; 6083 struct drm_dp_aux *immediate_upstream_aux; 6084 struct drm_dp_mst_port *fec_port; 6085 struct drm_dp_desc desc = {}; 6086 u8 upstream_dsc; 6087 u8 endpoint_fec; 6088 u8 endpoint_dsc; 6089 6090 if (!port) 6091 return NULL; 6092 6093 if (port->parent->port_parent) 6094 immediate_upstream_port = port->parent->port_parent; 6095 else 6096 immediate_upstream_port = NULL; 6097 6098 fec_port = immediate_upstream_port; 6099 while (fec_port) { 6100 /* 6101 * Each physical link (i.e. not a virtual port) between the 6102 * output and the primary device must support FEC 6103 */ 6104 if (!drm_dp_mst_is_virtual_dpcd(fec_port) && 6105 !fec_port->fec_capable) 6106 return NULL; 6107 6108 fec_port = fec_port->parent->port_parent; 6109 } 6110 6111 /* DP-to-DP peer device */ 6112 if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) { 6113 if (drm_dp_dpcd_read_data(&port->aux, 6114 DP_DSC_SUPPORT, &endpoint_dsc, 1) < 0) 6115 return NULL; 6116 if (drm_dp_dpcd_read_data(&port->aux, 6117 DP_FEC_CAPABILITY, &endpoint_fec, 1) < 0) 6118 return NULL; 6119 if (drm_dp_dpcd_read_data(&immediate_upstream_port->aux, 6120 DP_DSC_SUPPORT, &upstream_dsc, 1) < 0) 6121 return NULL; 6122 6123 /* Enpoint decompression with DP-to-DP peer device */ 6124 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) && 6125 (endpoint_fec & DP_FEC_CAPABLE) && 6126 (upstream_dsc & DP_DSC_PASSTHROUGH_IS_SUPPORTED)) { 6127 port->passthrough_aux = &immediate_upstream_port->aux; 6128 return &port->aux; 6129 } 6130 6131 /* Virtual DPCD decompression with DP-to-DP peer device */ 6132 return &immediate_upstream_port->aux; 6133 } 6134 6135 /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */ 6136 if (drm_dp_mst_is_virtual_dpcd(port)) 6137 return &port->aux; 6138 6139 /* 6140 * Synaptics quirk 6141 * Applies to ports for which: 6142 * - Physical aux has Synaptics OUI 6143 * - DPv1.4 or higher 6144 * - Port is on primary branch device 6145 * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG) 6146 */ 6147 if (immediate_upstream_port) 6148 immediate_upstream_aux = &immediate_upstream_port->aux; 6149 else 6150 immediate_upstream_aux = port->mgr->aux; 6151 6152 if (drm_dp_read_desc(immediate_upstream_aux, &desc, true)) 6153 return NULL; 6154 6155 if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD)) { 6156 u8 dpcd_ext[DP_RECEIVER_CAP_SIZE]; 6157 6158 if (drm_dp_dpcd_read_data(immediate_upstream_aux, 6159 DP_DSC_SUPPORT, &upstream_dsc, 1) < 0) 6160 return NULL; 6161 6162 if (!(upstream_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED)) 6163 return NULL; 6164 6165 if (drm_dp_read_dpcd_caps(immediate_upstream_aux, dpcd_ext) < 0) 6166 return NULL; 6167 6168 if (dpcd_ext[DP_DPCD_REV] >= DP_DPCD_REV_14 && 6169 ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT) && 6170 ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) 6171 != DP_DWN_STRM_PORT_TYPE_ANALOG))) 6172 return immediate_upstream_aux; 6173 } 6174 6175 /* 6176 * The check below verifies if the MST sink 6177 * connected to the GPU is capable of DSC - 6178 * therefore the endpoint needs to be 6179 * both DSC and FEC capable. 6180 */ 6181 if (drm_dp_dpcd_read_data(&port->aux, 6182 DP_DSC_SUPPORT, &endpoint_dsc, 1) < 0) 6183 return NULL; 6184 if (drm_dp_dpcd_read_data(&port->aux, 6185 DP_FEC_CAPABILITY, &endpoint_fec, 1) < 0) 6186 return NULL; 6187 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) && 6188 (endpoint_fec & DP_FEC_CAPABLE)) 6189 return &port->aux; 6190 6191 return NULL; 6192} 6193EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port);
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