drm_dp_mst_topology.c revision 1.4
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/i2c.h> 27#include <linux/init.h> 28#include <linux/kernel.h> 29#include <linux/random.h> 30#include <linux/sched.h> 31#include <linux/seq_file.h> 32#include <linux/iopoll.h> 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_print.h> 47#include <drm/drm_probe_helper.h> 48 49#include "drm_dp_helper_internal.h" 50#include "drm_dp_mst_topology_internal.h" 51 52/** 53 * DOC: dp mst helper 54 * 55 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport 56 * protocol. The helpers contain a topology manager and bandwidth manager. 57 * The helpers encapsulate the sending and received of sideband msgs. 58 */ 59struct drm_dp_pending_up_req { 60 struct drm_dp_sideband_msg_hdr hdr; 61 struct drm_dp_sideband_msg_req_body msg; 62 struct list_head next; 63}; 64 65static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, 66 char *buf); 67 68static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port); 69 70static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, 71 int id, u8 start_slot, u8 num_slots); 72 73static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, 74 struct drm_dp_mst_port *port, 75 int offset, int size, u8 *bytes); 76static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, 77 struct drm_dp_mst_port *port, 78 int offset, int size, u8 *bytes); 79 80static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 81 struct drm_dp_mst_branch *mstb); 82 83static void 84drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr, 85 struct drm_dp_mst_branch *mstb); 86 87static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, 88 struct drm_dp_mst_branch *mstb, 89 struct drm_dp_mst_port *port); 90static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, 91 u8 *guid); 92 93static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port); 94static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port); 95static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr); 96 97static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port, 98 struct drm_dp_mst_branch *branch); 99 100#define DBG_PREFIX "[dp_mst]" 101 102#define DP_STR(x) [DP_ ## x] = #x 103 104static const char *drm_dp_mst_req_type_str(u8 req_type) 105{ 106 static const char * const req_type_str[] = { 107 DP_STR(GET_MSG_TRANSACTION_VERSION), 108 DP_STR(LINK_ADDRESS), 109 DP_STR(CONNECTION_STATUS_NOTIFY), 110 DP_STR(ENUM_PATH_RESOURCES), 111 DP_STR(ALLOCATE_PAYLOAD), 112 DP_STR(QUERY_PAYLOAD), 113 DP_STR(RESOURCE_STATUS_NOTIFY), 114 DP_STR(CLEAR_PAYLOAD_ID_TABLE), 115 DP_STR(REMOTE_DPCD_READ), 116 DP_STR(REMOTE_DPCD_WRITE), 117 DP_STR(REMOTE_I2C_READ), 118 DP_STR(REMOTE_I2C_WRITE), 119 DP_STR(POWER_UP_PHY), 120 DP_STR(POWER_DOWN_PHY), 121 DP_STR(SINK_EVENT_NOTIFY), 122 DP_STR(QUERY_STREAM_ENC_STATUS), 123 }; 124 125 if (req_type >= ARRAY_SIZE(req_type_str) || 126 !req_type_str[req_type]) 127 return "unknown"; 128 129 return req_type_str[req_type]; 130} 131 132#undef DP_STR 133#define DP_STR(x) [DP_NAK_ ## x] = #x 134 135static const char *drm_dp_mst_nak_reason_str(u8 nak_reason) 136{ 137 static const char * const nak_reason_str[] = { 138 DP_STR(WRITE_FAILURE), 139 DP_STR(INVALID_READ), 140 DP_STR(CRC_FAILURE), 141 DP_STR(BAD_PARAM), 142 DP_STR(DEFER), 143 DP_STR(LINK_FAILURE), 144 DP_STR(NO_RESOURCES), 145 DP_STR(DPCD_FAIL), 146 DP_STR(I2C_NAK), 147 DP_STR(ALLOCATE_FAIL), 148 }; 149 150 if (nak_reason >= ARRAY_SIZE(nak_reason_str) || 151 !nak_reason_str[nak_reason]) 152 return "unknown"; 153 154 return nak_reason_str[nak_reason]; 155} 156 157#undef DP_STR 158#define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x 159 160static const char *drm_dp_mst_sideband_tx_state_str(int state) 161{ 162 static const char * const sideband_reason_str[] = { 163 DP_STR(QUEUED), 164 DP_STR(START_SEND), 165 DP_STR(SENT), 166 DP_STR(RX), 167 DP_STR(TIMEOUT), 168 }; 169 170 if (state >= ARRAY_SIZE(sideband_reason_str) || 171 !sideband_reason_str[state]) 172 return "unknown"; 173 174 return sideband_reason_str[state]; 175} 176 177static int 178drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len) 179{ 180 int i; 181 u8 unpacked_rad[16]; 182 183 for (i = 0; i < lct; i++) { 184 if (i % 2) 185 unpacked_rad[i] = rad[i / 2] >> 4; 186 else 187 unpacked_rad[i] = rad[i / 2] & BIT_MASK(4); 188 } 189 190 /* TODO: Eventually add something to printk so we can format the rad 191 * like this: 1.2.3 192 */ 193 return snprintf(out, len, "%*phC", lct, unpacked_rad); 194} 195 196/* sideband msg handling */ 197static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles) 198{ 199 u8 bitmask = 0x80; 200 u8 bitshift = 7; 201 u8 array_index = 0; 202 int number_of_bits = num_nibbles * 4; 203 u8 remainder = 0; 204 205 while (number_of_bits != 0) { 206 number_of_bits--; 207 remainder <<= 1; 208 remainder |= (data[array_index] & bitmask) >> bitshift; 209 bitmask >>= 1; 210 bitshift--; 211 if (bitmask == 0) { 212 bitmask = 0x80; 213 bitshift = 7; 214 array_index++; 215 } 216 if ((remainder & 0x10) == 0x10) 217 remainder ^= 0x13; 218 } 219 220 number_of_bits = 4; 221 while (number_of_bits != 0) { 222 number_of_bits--; 223 remainder <<= 1; 224 if ((remainder & 0x10) != 0) 225 remainder ^= 0x13; 226 } 227 228 return remainder; 229} 230 231static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes) 232{ 233 u8 bitmask = 0x80; 234 u8 bitshift = 7; 235 u8 array_index = 0; 236 int number_of_bits = number_of_bytes * 8; 237 u16 remainder = 0; 238 239 while (number_of_bits != 0) { 240 number_of_bits--; 241 remainder <<= 1; 242 remainder |= (data[array_index] & bitmask) >> bitshift; 243 bitmask >>= 1; 244 bitshift--; 245 if (bitmask == 0) { 246 bitmask = 0x80; 247 bitshift = 7; 248 array_index++; 249 } 250 if ((remainder & 0x100) == 0x100) 251 remainder ^= 0xd5; 252 } 253 254 number_of_bits = 8; 255 while (number_of_bits != 0) { 256 number_of_bits--; 257 remainder <<= 1; 258 if ((remainder & 0x100) != 0) 259 remainder ^= 0xd5; 260 } 261 262 return remainder & 0xff; 263} 264static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr) 265{ 266 u8 size = 3; 267 268 size += (hdr->lct / 2); 269 return size; 270} 271 272static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr, 273 u8 *buf, int *len) 274{ 275 int idx = 0; 276 int i; 277 u8 crc4; 278 279 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf); 280 for (i = 0; i < (hdr->lct / 2); i++) 281 buf[idx++] = hdr->rad[i]; 282 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) | 283 (hdr->msg_len & 0x3f); 284 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4); 285 286 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1); 287 buf[idx - 1] |= (crc4 & 0xf); 288 289 *len = idx; 290} 291 292static bool drm_dp_decode_sideband_msg_hdr(const struct drm_dp_mst_topology_mgr *mgr, 293 struct drm_dp_sideband_msg_hdr *hdr, 294 u8 *buf, int buflen, u8 *hdrlen) 295{ 296 u8 crc4; 297 u8 len; 298 int i; 299 u8 idx; 300 301 if (buf[0] == 0) 302 return false; 303 len = 3; 304 len += ((buf[0] & 0xf0) >> 4) / 2; 305 if (len > buflen) 306 return false; 307 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1); 308 309 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) { 310 drm_dbg_kms(mgr->dev, "crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]); 311 return false; 312 } 313 314 hdr->lct = (buf[0] & 0xf0) >> 4; 315 hdr->lcr = (buf[0] & 0xf); 316 idx = 1; 317 for (i = 0; i < (hdr->lct / 2); i++) 318 hdr->rad[i] = buf[idx++]; 319 hdr->broadcast = (buf[idx] >> 7) & 0x1; 320 hdr->path_msg = (buf[idx] >> 6) & 0x1; 321 hdr->msg_len = buf[idx] & 0x3f; 322 idx++; 323 hdr->somt = (buf[idx] >> 7) & 0x1; 324 hdr->eomt = (buf[idx] >> 6) & 0x1; 325 hdr->seqno = (buf[idx] >> 4) & 0x1; 326 idx++; 327 *hdrlen = idx; 328 return true; 329} 330 331void 332drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req, 333 struct drm_dp_sideband_msg_tx *raw) 334{ 335 int idx = 0; 336 int i; 337 u8 *buf = raw->msg; 338 339 buf[idx++] = req->req_type & 0x7f; 340 341 switch (req->req_type) { 342 case DP_ENUM_PATH_RESOURCES: 343 case DP_POWER_DOWN_PHY: 344 case DP_POWER_UP_PHY: 345 buf[idx] = (req->u.port_num.port_number & 0xf) << 4; 346 idx++; 347 break; 348 case DP_ALLOCATE_PAYLOAD: 349 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 | 350 (req->u.allocate_payload.number_sdp_streams & 0xf); 351 idx++; 352 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f); 353 idx++; 354 buf[idx] = (req->u.allocate_payload.pbn >> 8); 355 idx++; 356 buf[idx] = (req->u.allocate_payload.pbn & 0xff); 357 idx++; 358 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) { 359 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) | 360 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf); 361 idx++; 362 } 363 if (req->u.allocate_payload.number_sdp_streams & 1) { 364 i = req->u.allocate_payload.number_sdp_streams - 1; 365 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4; 366 idx++; 367 } 368 break; 369 case DP_QUERY_PAYLOAD: 370 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4; 371 idx++; 372 buf[idx] = (req->u.query_payload.vcpi & 0x7f); 373 idx++; 374 break; 375 case DP_REMOTE_DPCD_READ: 376 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4; 377 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf; 378 idx++; 379 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8; 380 idx++; 381 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff); 382 idx++; 383 buf[idx] = (req->u.dpcd_read.num_bytes); 384 idx++; 385 break; 386 387 case DP_REMOTE_DPCD_WRITE: 388 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4; 389 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf; 390 idx++; 391 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8; 392 idx++; 393 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff); 394 idx++; 395 buf[idx] = (req->u.dpcd_write.num_bytes); 396 idx++; 397 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes); 398 idx += req->u.dpcd_write.num_bytes; 399 break; 400 case DP_REMOTE_I2C_READ: 401 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4; 402 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3); 403 idx++; 404 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) { 405 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f; 406 idx++; 407 buf[idx] = req->u.i2c_read.transactions[i].num_bytes; 408 idx++; 409 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes); 410 idx += req->u.i2c_read.transactions[i].num_bytes; 411 412 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4; 413 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf); 414 idx++; 415 } 416 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f; 417 idx++; 418 buf[idx] = (req->u.i2c_read.num_bytes_read); 419 idx++; 420 break; 421 422 case DP_REMOTE_I2C_WRITE: 423 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4; 424 idx++; 425 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f; 426 idx++; 427 buf[idx] = (req->u.i2c_write.num_bytes); 428 idx++; 429 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes); 430 idx += req->u.i2c_write.num_bytes; 431 break; 432 case DP_QUERY_STREAM_ENC_STATUS: { 433 const struct drm_dp_query_stream_enc_status *msg; 434 435 msg = &req->u.enc_status; 436 buf[idx] = msg->stream_id; 437 idx++; 438 memcpy(&buf[idx], msg->client_id, sizeof(msg->client_id)); 439 idx += sizeof(msg->client_id); 440 buf[idx] = 0; 441 buf[idx] |= FIELD_PREP(GENMASK(1, 0), msg->stream_event); 442 buf[idx] |= msg->valid_stream_event ? BIT(2) : 0; 443 buf[idx] |= FIELD_PREP(GENMASK(4, 3), msg->stream_behavior); 444 buf[idx] |= msg->valid_stream_behavior ? BIT(5) : 0; 445 idx++; 446 } 447 break; 448 } 449 raw->cur_len = idx; 450} 451EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req); 452 453/* Decode a sideband request we've encoded, mainly used for debugging */ 454int 455drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw, 456 struct drm_dp_sideband_msg_req_body *req) 457{ 458 const u8 *buf = raw->msg; 459 int i, idx = 0; 460 461 req->req_type = buf[idx++] & 0x7f; 462 switch (req->req_type) { 463 case DP_ENUM_PATH_RESOURCES: 464 case DP_POWER_DOWN_PHY: 465 case DP_POWER_UP_PHY: 466 req->u.port_num.port_number = (buf[idx] >> 4) & 0xf; 467 break; 468 case DP_ALLOCATE_PAYLOAD: 469 { 470 struct drm_dp_allocate_payload *a = 471 &req->u.allocate_payload; 472 473 a->number_sdp_streams = buf[idx] & 0xf; 474 a->port_number = (buf[idx] >> 4) & 0xf; 475 476 WARN_ON(buf[++idx] & 0x80); 477 a->vcpi = buf[idx] & 0x7f; 478 479 a->pbn = buf[++idx] << 8; 480 a->pbn |= buf[++idx]; 481 482 idx++; 483 for (i = 0; i < a->number_sdp_streams; i++) { 484 a->sdp_stream_sink[i] = 485 (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf; 486 } 487 } 488 break; 489 case DP_QUERY_PAYLOAD: 490 req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf; 491 WARN_ON(buf[++idx] & 0x80); 492 req->u.query_payload.vcpi = buf[idx] & 0x7f; 493 break; 494 case DP_REMOTE_DPCD_READ: 495 { 496 struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read; 497 498 r->port_number = (buf[idx] >> 4) & 0xf; 499 500 r->dpcd_address = (buf[idx] << 16) & 0xf0000; 501 r->dpcd_address |= (buf[++idx] << 8) & 0xff00; 502 r->dpcd_address |= buf[++idx] & 0xff; 503 504 r->num_bytes = buf[++idx]; 505 } 506 break; 507 case DP_REMOTE_DPCD_WRITE: 508 { 509 struct drm_dp_remote_dpcd_write *w = 510 &req->u.dpcd_write; 511 512 w->port_number = (buf[idx] >> 4) & 0xf; 513 514 w->dpcd_address = (buf[idx] << 16) & 0xf0000; 515 w->dpcd_address |= (buf[++idx] << 8) & 0xff00; 516 w->dpcd_address |= buf[++idx] & 0xff; 517 518 w->num_bytes = buf[++idx]; 519 520 w->bytes = kmemdup(&buf[++idx], w->num_bytes, 521 GFP_KERNEL); 522 if (!w->bytes) 523 return -ENOMEM; 524 } 525 break; 526 case DP_REMOTE_I2C_READ: 527 { 528 struct drm_dp_remote_i2c_read *r = &req->u.i2c_read; 529 struct drm_dp_remote_i2c_read_tx *tx; 530 bool failed = false; 531 532 r->num_transactions = buf[idx] & 0x3; 533 r->port_number = (buf[idx] >> 4) & 0xf; 534 for (i = 0; i < r->num_transactions; i++) { 535 tx = &r->transactions[i]; 536 537 tx->i2c_dev_id = buf[++idx] & 0x7f; 538 tx->num_bytes = buf[++idx]; 539 tx->bytes = kmemdup(&buf[++idx], 540 tx->num_bytes, 541 GFP_KERNEL); 542 if (!tx->bytes) { 543 failed = true; 544 break; 545 } 546 idx += tx->num_bytes; 547 tx->no_stop_bit = (buf[idx] >> 5) & 0x1; 548 tx->i2c_transaction_delay = buf[idx] & 0xf; 549 } 550 551 if (failed) { 552 for (i = 0; i < r->num_transactions; i++) { 553 tx = &r->transactions[i]; 554 kfree(tx->bytes); 555 } 556 return -ENOMEM; 557 } 558 559 r->read_i2c_device_id = buf[++idx] & 0x7f; 560 r->num_bytes_read = buf[++idx]; 561 } 562 break; 563 case DP_REMOTE_I2C_WRITE: 564 { 565 struct drm_dp_remote_i2c_write *w = &req->u.i2c_write; 566 567 w->port_number = (buf[idx] >> 4) & 0xf; 568 w->write_i2c_device_id = buf[++idx] & 0x7f; 569 w->num_bytes = buf[++idx]; 570 w->bytes = kmemdup(&buf[++idx], w->num_bytes, 571 GFP_KERNEL); 572 if (!w->bytes) 573 return -ENOMEM; 574 } 575 break; 576 case DP_QUERY_STREAM_ENC_STATUS: 577 req->u.enc_status.stream_id = buf[idx++]; 578 for (i = 0; i < sizeof(req->u.enc_status.client_id); i++) 579 req->u.enc_status.client_id[i] = buf[idx++]; 580 581 req->u.enc_status.stream_event = FIELD_GET(GENMASK(1, 0), 582 buf[idx]); 583 req->u.enc_status.valid_stream_event = FIELD_GET(BIT(2), 584 buf[idx]); 585 req->u.enc_status.stream_behavior = FIELD_GET(GENMASK(4, 3), 586 buf[idx]); 587 req->u.enc_status.valid_stream_behavior = FIELD_GET(BIT(5), 588 buf[idx]); 589 break; 590 } 591 592 return 0; 593} 594EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req); 595 596void 597drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req, 598 int indent, struct drm_printer *printer) 599{ 600 int i; 601 602#define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__) 603 if (req->req_type == DP_LINK_ADDRESS) { 604 /* No contents to print */ 605 P("type=%s\n", drm_dp_mst_req_type_str(req->req_type)); 606 return; 607 } 608 609 P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type)); 610 indent++; 611 612 switch (req->req_type) { 613 case DP_ENUM_PATH_RESOURCES: 614 case DP_POWER_DOWN_PHY: 615 case DP_POWER_UP_PHY: 616 P("port=%d\n", req->u.port_num.port_number); 617 break; 618 case DP_ALLOCATE_PAYLOAD: 619 P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n", 620 req->u.allocate_payload.port_number, 621 req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn, 622 req->u.allocate_payload.number_sdp_streams, 623 req->u.allocate_payload.number_sdp_streams, 624 req->u.allocate_payload.sdp_stream_sink); 625 break; 626 case DP_QUERY_PAYLOAD: 627 P("port=%d vcpi=%d\n", 628 req->u.query_payload.port_number, 629 req->u.query_payload.vcpi); 630 break; 631 case DP_REMOTE_DPCD_READ: 632 P("port=%d dpcd_addr=%05x len=%d\n", 633 req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address, 634 req->u.dpcd_read.num_bytes); 635 break; 636 case DP_REMOTE_DPCD_WRITE: 637 P("port=%d addr=%05x len=%d: %*ph\n", 638 req->u.dpcd_write.port_number, 639 req->u.dpcd_write.dpcd_address, 640 req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes, 641 req->u.dpcd_write.bytes); 642 break; 643 case DP_REMOTE_I2C_READ: 644 P("port=%d num_tx=%d id=%d size=%d:\n", 645 req->u.i2c_read.port_number, 646 req->u.i2c_read.num_transactions, 647 req->u.i2c_read.read_i2c_device_id, 648 req->u.i2c_read.num_bytes_read); 649 650 indent++; 651 for (i = 0; i < req->u.i2c_read.num_transactions; i++) { 652 const struct drm_dp_remote_i2c_read_tx *rtx = 653 &req->u.i2c_read.transactions[i]; 654 655 P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n", 656 i, rtx->i2c_dev_id, rtx->num_bytes, 657 rtx->no_stop_bit, rtx->i2c_transaction_delay, 658 rtx->num_bytes, rtx->bytes); 659 } 660 break; 661 case DP_REMOTE_I2C_WRITE: 662 P("port=%d id=%d size=%d: %*ph\n", 663 req->u.i2c_write.port_number, 664 req->u.i2c_write.write_i2c_device_id, 665 req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes, 666 req->u.i2c_write.bytes); 667 break; 668 case DP_QUERY_STREAM_ENC_STATUS: 669 P("stream_id=%u client_id=%*ph stream_event=%x " 670 "valid_event=%d stream_behavior=%x valid_behavior=%d", 671 req->u.enc_status.stream_id, 672 (int)ARRAY_SIZE(req->u.enc_status.client_id), 673 req->u.enc_status.client_id, req->u.enc_status.stream_event, 674 req->u.enc_status.valid_stream_event, 675 req->u.enc_status.stream_behavior, 676 req->u.enc_status.valid_stream_behavior); 677 break; 678 default: 679 P("???\n"); 680 break; 681 } 682#undef P 683} 684EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body); 685 686static inline void 687drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p, 688 const struct drm_dp_sideband_msg_tx *txmsg) 689{ 690 struct drm_dp_sideband_msg_req_body req; 691 char buf[64]; 692 int ret; 693 int i; 694 695 drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf, 696 sizeof(buf)); 697 drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n", 698 txmsg->cur_offset, txmsg->cur_len, txmsg->seqno, 699 drm_dp_mst_sideband_tx_state_str(txmsg->state), 700 txmsg->path_msg, buf); 701 702 ret = drm_dp_decode_sideband_req(txmsg, &req); 703 if (ret) { 704 drm_printf(p, "<failed to decode sideband req: %d>\n", ret); 705 return; 706 } 707 drm_dp_dump_sideband_msg_req_body(&req, 1, p); 708 709 switch (req.req_type) { 710 case DP_REMOTE_DPCD_WRITE: 711 kfree(req.u.dpcd_write.bytes); 712 break; 713 case DP_REMOTE_I2C_READ: 714 for (i = 0; i < req.u.i2c_read.num_transactions; i++) 715 kfree(req.u.i2c_read.transactions[i].bytes); 716 break; 717 case DP_REMOTE_I2C_WRITE: 718 kfree(req.u.i2c_write.bytes); 719 break; 720 } 721} 722 723static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len) 724{ 725 u8 crc4; 726 727 crc4 = drm_dp_msg_data_crc4(msg, len); 728 msg[len] = crc4; 729} 730 731static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep, 732 struct drm_dp_sideband_msg_tx *raw) 733{ 734 int idx = 0; 735 u8 *buf = raw->msg; 736 737 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f); 738 739 raw->cur_len = idx; 740} 741 742static int drm_dp_sideband_msg_set_header(struct drm_dp_sideband_msg_rx *msg, 743 struct drm_dp_sideband_msg_hdr *hdr, 744 u8 hdrlen) 745{ 746 /* 747 * ignore out-of-order messages or messages that are part of a 748 * failed transaction 749 */ 750 if (!hdr->somt && !msg->have_somt) 751 return false; 752 753 /* get length contained in this portion */ 754 msg->curchunk_idx = 0; 755 msg->curchunk_len = hdr->msg_len; 756 msg->curchunk_hdrlen = hdrlen; 757 758 /* we have already gotten an somt - don't bother parsing */ 759 if (hdr->somt && msg->have_somt) 760 return false; 761 762 if (hdr->somt) { 763 memcpy(&msg->initial_hdr, hdr, 764 sizeof(struct drm_dp_sideband_msg_hdr)); 765 msg->have_somt = true; 766 } 767 if (hdr->eomt) 768 msg->have_eomt = true; 769 770 return true; 771} 772 773/* this adds a chunk of msg to the builder to get the final msg */ 774static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx *msg, 775 u8 *replybuf, u8 replybuflen) 776{ 777 u8 crc4; 778 779 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen); 780 msg->curchunk_idx += replybuflen; 781 782 if (msg->curchunk_idx >= msg->curchunk_len) { 783 /* do CRC */ 784 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1); 785 if (crc4 != msg->chunk[msg->curchunk_len - 1]) 786 print_hex_dump(KERN_DEBUG, "wrong crc", 787 DUMP_PREFIX_NONE, 16, 1, 788 msg->chunk, msg->curchunk_len, false); 789 /* copy chunk into bigger msg */ 790 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1); 791 msg->curlen += msg->curchunk_len - 1; 792 } 793 return true; 794} 795 796static bool drm_dp_sideband_parse_link_address(const struct drm_dp_mst_topology_mgr *mgr, 797 struct drm_dp_sideband_msg_rx *raw, 798 struct drm_dp_sideband_msg_reply_body *repmsg) 799{ 800 int idx = 1; 801 int i; 802 803 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16); 804 idx += 16; 805 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf; 806 idx++; 807 if (idx > raw->curlen) 808 goto fail_len; 809 for (i = 0; i < repmsg->u.link_addr.nports; i++) { 810 if (raw->msg[idx] & 0x80) 811 repmsg->u.link_addr.ports[i].input_port = 1; 812 813 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7; 814 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf); 815 816 idx++; 817 if (idx > raw->curlen) 818 goto fail_len; 819 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1; 820 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1; 821 if (repmsg->u.link_addr.ports[i].input_port == 0) 822 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1; 823 idx++; 824 if (idx > raw->curlen) 825 goto fail_len; 826 if (repmsg->u.link_addr.ports[i].input_port == 0) { 827 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]); 828 idx++; 829 if (idx > raw->curlen) 830 goto fail_len; 831 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16); 832 idx += 16; 833 if (idx > raw->curlen) 834 goto fail_len; 835 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf; 836 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf); 837 idx++; 838 839 } 840 if (idx > raw->curlen) 841 goto fail_len; 842 } 843 844 return true; 845fail_len: 846 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); 847 return false; 848} 849 850static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw, 851 struct drm_dp_sideband_msg_reply_body *repmsg) 852{ 853 int idx = 1; 854 855 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf; 856 idx++; 857 if (idx > raw->curlen) 858 goto fail_len; 859 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx]; 860 idx++; 861 if (idx > raw->curlen) 862 goto fail_len; 863 864 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes); 865 return true; 866fail_len: 867 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); 868 return false; 869} 870 871static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw, 872 struct drm_dp_sideband_msg_reply_body *repmsg) 873{ 874 int idx = 1; 875 876 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf; 877 idx++; 878 if (idx > raw->curlen) 879 goto fail_len; 880 return true; 881fail_len: 882 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen); 883 return false; 884} 885 886static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw, 887 struct drm_dp_sideband_msg_reply_body *repmsg) 888{ 889 int idx = 1; 890 891 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf); 892 idx++; 893 if (idx > raw->curlen) 894 goto fail_len; 895 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx]; 896 idx++; 897 /* TODO check */ 898 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes); 899 return true; 900fail_len: 901 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen); 902 return false; 903} 904 905static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw, 906 struct drm_dp_sideband_msg_reply_body *repmsg) 907{ 908 int idx = 1; 909 910 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf; 911 repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1; 912 idx++; 913 if (idx > raw->curlen) 914 goto fail_len; 915 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 916 idx += 2; 917 if (idx > raw->curlen) 918 goto fail_len; 919 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 920 idx += 2; 921 if (idx > raw->curlen) 922 goto fail_len; 923 return true; 924fail_len: 925 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen); 926 return false; 927} 928 929static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw, 930 struct drm_dp_sideband_msg_reply_body *repmsg) 931{ 932 int idx = 1; 933 934 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf; 935 idx++; 936 if (idx > raw->curlen) 937 goto fail_len; 938 repmsg->u.allocate_payload.vcpi = raw->msg[idx]; 939 idx++; 940 if (idx > raw->curlen) 941 goto fail_len; 942 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 943 idx += 2; 944 if (idx > raw->curlen) 945 goto fail_len; 946 return true; 947fail_len: 948 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen); 949 return false; 950} 951 952static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw, 953 struct drm_dp_sideband_msg_reply_body *repmsg) 954{ 955 int idx = 1; 956 957 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf; 958 idx++; 959 if (idx > raw->curlen) 960 goto fail_len; 961 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); 962 idx += 2; 963 if (idx > raw->curlen) 964 goto fail_len; 965 return true; 966fail_len: 967 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen); 968 return false; 969} 970 971static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw, 972 struct drm_dp_sideband_msg_reply_body *repmsg) 973{ 974 int idx = 1; 975 976 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf; 977 idx++; 978 if (idx > raw->curlen) { 979 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n", 980 idx, raw->curlen); 981 return false; 982 } 983 return true; 984} 985 986static bool 987drm_dp_sideband_parse_query_stream_enc_status( 988 struct drm_dp_sideband_msg_rx *raw, 989 struct drm_dp_sideband_msg_reply_body *repmsg) 990{ 991 struct drm_dp_query_stream_enc_status_ack_reply *reply; 992 993 reply = &repmsg->u.enc_status; 994 995 reply->stream_id = raw->msg[3]; 996 997 reply->reply_signed = raw->msg[2] & BIT(0); 998 999 /* 1000 * NOTE: It's my impression from reading the spec that the below parsing 1001 * is correct. However I noticed while testing with an HDCP 1.4 display 1002 * through an HDCP 2.2 hub that only bit 3 was set. In that case, I 1003 * would expect both bits to be set. So keep the parsing following the 1004 * spec, but beware reality might not match the spec (at least for some 1005 * configurations). 1006 */ 1007 reply->hdcp_1x_device_present = raw->msg[2] & BIT(4); 1008 reply->hdcp_2x_device_present = raw->msg[2] & BIT(3); 1009 1010 reply->query_capable_device_present = raw->msg[2] & BIT(5); 1011 reply->legacy_device_present = raw->msg[2] & BIT(6); 1012 reply->unauthorizable_device_present = raw->msg[2] & BIT(7); 1013 1014 reply->auth_completed = !!(raw->msg[1] & BIT(3)); 1015 reply->encryption_enabled = !!(raw->msg[1] & BIT(4)); 1016 reply->repeater_present = !!(raw->msg[1] & BIT(5)); 1017 reply->state = (raw->msg[1] & GENMASK(7, 6)) >> 6; 1018 1019 return true; 1020} 1021 1022static bool drm_dp_sideband_parse_reply(const struct drm_dp_mst_topology_mgr *mgr, 1023 struct drm_dp_sideband_msg_rx *raw, 1024 struct drm_dp_sideband_msg_reply_body *msg) 1025{ 1026 memset(msg, 0, sizeof(*msg)); 1027 msg->reply_type = (raw->msg[0] & 0x80) >> 7; 1028 msg->req_type = (raw->msg[0] & 0x7f); 1029 1030 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) { 1031 memcpy(msg->u.nak.guid, &raw->msg[1], 16); 1032 msg->u.nak.reason = raw->msg[17]; 1033 msg->u.nak.nak_data = raw->msg[18]; 1034 return false; 1035 } 1036 1037 switch (msg->req_type) { 1038 case DP_LINK_ADDRESS: 1039 return drm_dp_sideband_parse_link_address(mgr, raw, msg); 1040 case DP_QUERY_PAYLOAD: 1041 return drm_dp_sideband_parse_query_payload_ack(raw, msg); 1042 case DP_REMOTE_DPCD_READ: 1043 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg); 1044 case DP_REMOTE_DPCD_WRITE: 1045 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg); 1046 case DP_REMOTE_I2C_READ: 1047 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg); 1048 case DP_REMOTE_I2C_WRITE: 1049 return true; /* since there's nothing to parse */ 1050 case DP_ENUM_PATH_RESOURCES: 1051 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg); 1052 case DP_ALLOCATE_PAYLOAD: 1053 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg); 1054 case DP_POWER_DOWN_PHY: 1055 case DP_POWER_UP_PHY: 1056 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg); 1057 case DP_CLEAR_PAYLOAD_ID_TABLE: 1058 return true; /* since there's nothing to parse */ 1059 case DP_QUERY_STREAM_ENC_STATUS: 1060 return drm_dp_sideband_parse_query_stream_enc_status(raw, msg); 1061 default: 1062 drm_err(mgr->dev, "Got unknown reply 0x%02x (%s)\n", 1063 msg->req_type, drm_dp_mst_req_type_str(msg->req_type)); 1064 return false; 1065 } 1066} 1067 1068static bool 1069drm_dp_sideband_parse_connection_status_notify(const struct drm_dp_mst_topology_mgr *mgr, 1070 struct drm_dp_sideband_msg_rx *raw, 1071 struct drm_dp_sideband_msg_req_body *msg) 1072{ 1073 int idx = 1; 1074 1075 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; 1076 idx++; 1077 if (idx > raw->curlen) 1078 goto fail_len; 1079 1080 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16); 1081 idx += 16; 1082 if (idx > raw->curlen) 1083 goto fail_len; 1084 1085 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1; 1086 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1; 1087 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1; 1088 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1; 1089 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7); 1090 idx++; 1091 return true; 1092fail_len: 1093 drm_dbg_kms(mgr->dev, "connection status reply parse length fail %d %d\n", 1094 idx, raw->curlen); 1095 return false; 1096} 1097 1098static bool drm_dp_sideband_parse_resource_status_notify(const struct drm_dp_mst_topology_mgr *mgr, 1099 struct drm_dp_sideband_msg_rx *raw, 1100 struct drm_dp_sideband_msg_req_body *msg) 1101{ 1102 int idx = 1; 1103 1104 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; 1105 idx++; 1106 if (idx > raw->curlen) 1107 goto fail_len; 1108 1109 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16); 1110 idx += 16; 1111 if (idx > raw->curlen) 1112 goto fail_len; 1113 1114 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); 1115 idx++; 1116 return true; 1117fail_len: 1118 drm_dbg_kms(mgr->dev, "resource status reply parse length fail %d %d\n", idx, raw->curlen); 1119 return false; 1120} 1121 1122static bool drm_dp_sideband_parse_req(const struct drm_dp_mst_topology_mgr *mgr, 1123 struct drm_dp_sideband_msg_rx *raw, 1124 struct drm_dp_sideband_msg_req_body *msg) 1125{ 1126 memset(msg, 0, sizeof(*msg)); 1127 msg->req_type = (raw->msg[0] & 0x7f); 1128 1129 switch (msg->req_type) { 1130 case DP_CONNECTION_STATUS_NOTIFY: 1131 return drm_dp_sideband_parse_connection_status_notify(mgr, raw, msg); 1132 case DP_RESOURCE_STATUS_NOTIFY: 1133 return drm_dp_sideband_parse_resource_status_notify(mgr, raw, msg); 1134 default: 1135 drm_err(mgr->dev, "Got unknown request 0x%02x (%s)\n", 1136 msg->req_type, drm_dp_mst_req_type_str(msg->req_type)); 1137 return false; 1138 } 1139} 1140 1141static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, 1142 u8 port_num, u32 offset, u8 num_bytes, u8 *bytes) 1143{ 1144 struct drm_dp_sideband_msg_req_body req; 1145 1146 req.req_type = DP_REMOTE_DPCD_WRITE; 1147 req.u.dpcd_write.port_number = port_num; 1148 req.u.dpcd_write.dpcd_address = offset; 1149 req.u.dpcd_write.num_bytes = num_bytes; 1150 req.u.dpcd_write.bytes = bytes; 1151 drm_dp_encode_sideband_req(&req, msg); 1152} 1153 1154static void build_link_address(struct drm_dp_sideband_msg_tx *msg) 1155{ 1156 struct drm_dp_sideband_msg_req_body req; 1157 1158 req.req_type = DP_LINK_ADDRESS; 1159 drm_dp_encode_sideband_req(&req, msg); 1160} 1161 1162static void build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg) 1163{ 1164 struct drm_dp_sideband_msg_req_body req; 1165 1166 req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE; 1167 drm_dp_encode_sideband_req(&req, msg); 1168 msg->path_msg = true; 1169} 1170 1171static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, 1172 int port_num) 1173{ 1174 struct drm_dp_sideband_msg_req_body req; 1175 1176 req.req_type = DP_ENUM_PATH_RESOURCES; 1177 req.u.port_num.port_number = port_num; 1178 drm_dp_encode_sideband_req(&req, msg); 1179 msg->path_msg = true; 1180 return 0; 1181} 1182 1183static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, 1184 int port_num, 1185 u8 vcpi, uint16_t pbn, 1186 u8 number_sdp_streams, 1187 u8 *sdp_stream_sink) 1188{ 1189 struct drm_dp_sideband_msg_req_body req; 1190 1191 memset(&req, 0, sizeof(req)); 1192 req.req_type = DP_ALLOCATE_PAYLOAD; 1193 req.u.allocate_payload.port_number = port_num; 1194 req.u.allocate_payload.vcpi = vcpi; 1195 req.u.allocate_payload.pbn = pbn; 1196 req.u.allocate_payload.number_sdp_streams = number_sdp_streams; 1197 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink, 1198 number_sdp_streams); 1199 drm_dp_encode_sideband_req(&req, msg); 1200 msg->path_msg = true; 1201} 1202 1203static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg, 1204 int port_num, bool power_up) 1205{ 1206 struct drm_dp_sideband_msg_req_body req; 1207 1208 if (power_up) 1209 req.req_type = DP_POWER_UP_PHY; 1210 else 1211 req.req_type = DP_POWER_DOWN_PHY; 1212 1213 req.u.port_num.port_number = port_num; 1214 drm_dp_encode_sideband_req(&req, msg); 1215 msg->path_msg = true; 1216} 1217 1218static int 1219build_query_stream_enc_status(struct drm_dp_sideband_msg_tx *msg, u8 stream_id, 1220 u8 *q_id) 1221{ 1222 struct drm_dp_sideband_msg_req_body req; 1223 1224 req.req_type = DP_QUERY_STREAM_ENC_STATUS; 1225 req.u.enc_status.stream_id = stream_id; 1226 memcpy(req.u.enc_status.client_id, q_id, 1227 sizeof(req.u.enc_status.client_id)); 1228 req.u.enc_status.stream_event = 0; 1229 req.u.enc_status.valid_stream_event = false; 1230 req.u.enc_status.stream_behavior = 0; 1231 req.u.enc_status.valid_stream_behavior = false; 1232 1233 drm_dp_encode_sideband_req(&req, msg); 1234 return 0; 1235} 1236 1237static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr, 1238 struct drm_dp_sideband_msg_tx *txmsg) 1239{ 1240 unsigned int state; 1241 1242 /* 1243 * All updates to txmsg->state are protected by mgr->qlock, and the two 1244 * cases we check here are terminal states. For those the barriers 1245 * provided by the wake_up/wait_event pair are enough. 1246 */ 1247 state = READ_ONCE(txmsg->state); 1248 return (state == DRM_DP_SIDEBAND_TX_RX || 1249 state == DRM_DP_SIDEBAND_TX_TIMEOUT); 1250} 1251 1252static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb, 1253 struct drm_dp_sideband_msg_tx *txmsg) 1254{ 1255 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 1256 unsigned long wait_timeout = msecs_to_jiffies(4000); 1257 unsigned long wait_expires = jiffies + wait_timeout; 1258 int ret; 1259 1260 for (;;) { 1261 /* 1262 * If the driver provides a way for this, change to 1263 * poll-waiting for the MST reply interrupt if we didn't receive 1264 * it for 50 msec. This would cater for cases where the HPD 1265 * pulse signal got lost somewhere, even though the sink raised 1266 * the corresponding MST interrupt correctly. One example is the 1267 * Club 3D CAC-1557 TypeC -> DP adapter which for some reason 1268 * filters out short pulses with a duration less than ~540 usec. 1269 * 1270 * The poll period is 50 msec to avoid missing an interrupt 1271 * after the sink has cleared it (after a 110msec timeout 1272 * since it raised the interrupt). 1273 */ 1274 ret = wait_event_timeout(mgr->tx_waitq, 1275 check_txmsg_state(mgr, txmsg), 1276 mgr->cbs->poll_hpd_irq ? 1277 msecs_to_jiffies(50) : 1278 wait_timeout); 1279 1280 if (ret || !mgr->cbs->poll_hpd_irq || 1281 time_after(jiffies, wait_expires)) 1282 break; 1283 1284 mgr->cbs->poll_hpd_irq(mgr); 1285 } 1286 1287 mutex_lock(&mgr->qlock); 1288 if (ret > 0) { 1289 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) { 1290 ret = -EIO; 1291 goto out; 1292 } 1293 } else { 1294 drm_dbg_kms(mgr->dev, "timedout msg send %p %d %d\n", 1295 txmsg, txmsg->state, txmsg->seqno); 1296 1297 /* dump some state */ 1298 ret = -EIO; 1299 1300 /* remove from q */ 1301 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED || 1302 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND || 1303 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) 1304 list_del(&txmsg->next); 1305 } 1306out: 1307 if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) { 1308 struct drm_printer p = drm_debug_printer(DBG_PREFIX); 1309 1310 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 1311 } 1312 mutex_unlock(&mgr->qlock); 1313 1314 drm_dp_mst_kick_tx(mgr); 1315 return ret; 1316} 1317 1318static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad) 1319{ 1320 struct drm_dp_mst_branch *mstb; 1321 1322 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL); 1323 if (!mstb) 1324 return NULL; 1325 1326 mstb->lct = lct; 1327 if (lct > 1) 1328 memcpy(mstb->rad, rad, lct / 2); 1329 INIT_LIST_HEAD(&mstb->ports); 1330 kref_init(&mstb->topology_kref); 1331 kref_init(&mstb->malloc_kref); 1332 return mstb; 1333} 1334 1335static void drm_dp_free_mst_branch_device(struct kref *kref) 1336{ 1337 struct drm_dp_mst_branch *mstb = 1338 container_of(kref, struct drm_dp_mst_branch, malloc_kref); 1339 1340 if (mstb->port_parent) 1341 drm_dp_mst_put_port_malloc(mstb->port_parent); 1342 1343 kfree(mstb); 1344} 1345 1346/** 1347 * DOC: Branch device and port refcounting 1348 * 1349 * Topology refcount overview 1350 * ~~~~~~~~~~~~~~~~~~~~~~~~~~ 1351 * 1352 * The refcounting schemes for &struct drm_dp_mst_branch and &struct 1353 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have 1354 * two different kinds of refcounts: topology refcounts, and malloc refcounts. 1355 * 1356 * Topology refcounts are not exposed to drivers, and are handled internally 1357 * by the DP MST helpers. The helpers use them in order to prevent the 1358 * in-memory topology state from being changed in the middle of critical 1359 * operations like changing the internal state of payload allocations. This 1360 * means each branch and port will be considered to be connected to the rest 1361 * of the topology until its topology refcount reaches zero. Additionally, 1362 * for ports this means that their associated &struct drm_connector will stay 1363 * registered with userspace until the port's refcount reaches 0. 1364 * 1365 * Malloc refcount overview 1366 * ~~~~~~~~~~~~~~~~~~~~~~~~ 1367 * 1368 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct 1369 * drm_dp_mst_branch allocated even after all of its topology references have 1370 * been dropped, so that the driver or MST helpers can safely access each 1371 * branch's last known state before it was disconnected from the topology. 1372 * When the malloc refcount of a port or branch reaches 0, the memory 1373 * allocation containing the &struct drm_dp_mst_branch or &struct 1374 * drm_dp_mst_port respectively will be freed. 1375 * 1376 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed 1377 * to drivers. As of writing this documentation, there are no drivers that 1378 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST 1379 * helpers. Exposing this API to drivers in a race-free manner would take more 1380 * tweaking of the refcounting scheme, however patches are welcome provided 1381 * there is a legitimate driver usecase for this. 1382 * 1383 * Refcount relationships in a topology 1384 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1385 * 1386 * Let's take a look at why the relationship between topology and malloc 1387 * refcounts is designed the way it is. 1388 * 1389 * .. kernel-figure:: dp-mst/topology-figure-1.dot 1390 * 1391 * An example of topology and malloc refs in a DP MST topology with two 1392 * active payloads. Topology refcount increments are indicated by solid 1393 * lines, and malloc refcount increments are indicated by dashed lines. 1394 * Each starts from the branch which incremented the refcount, and ends at 1395 * the branch to which the refcount belongs to, i.e. the arrow points the 1396 * same way as the C pointers used to reference a structure. 1397 * 1398 * As you can see in the above figure, every branch increments the topology 1399 * refcount of its children, and increments the malloc refcount of its 1400 * parent. Additionally, every payload increments the malloc refcount of its 1401 * assigned port by 1. 1402 * 1403 * So, what would happen if MSTB #3 from the above figure was unplugged from 1404 * the system, but the driver hadn't yet removed payload #2 from port #3? The 1405 * topology would start to look like the figure below. 1406 * 1407 * .. kernel-figure:: dp-mst/topology-figure-2.dot 1408 * 1409 * Ports and branch devices which have been released from memory are 1410 * colored grey, and references which have been removed are colored red. 1411 * 1412 * Whenever a port or branch device's topology refcount reaches zero, it will 1413 * decrement the topology refcounts of all its children, the malloc refcount 1414 * of its parent, and finally its own malloc refcount. For MSTB #4 and port 1415 * #4, this means they both have been disconnected from the topology and freed 1416 * from memory. But, because payload #2 is still holding a reference to port 1417 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port 1418 * is still accessible from memory. This also means port #3 has not yet 1419 * decremented the malloc refcount of MSTB #3, so its &struct 1420 * drm_dp_mst_branch will also stay allocated in memory until port #3's 1421 * malloc refcount reaches 0. 1422 * 1423 * This relationship is necessary because in order to release payload #2, we 1424 * need to be able to figure out the last relative of port #3 that's still 1425 * connected to the topology. In this case, we would travel up the topology as 1426 * shown below. 1427 * 1428 * .. kernel-figure:: dp-mst/topology-figure-3.dot 1429 * 1430 * And finally, remove payload #2 by communicating with port #2 through 1431 * sideband transactions. 1432 */ 1433 1434/** 1435 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch 1436 * device 1437 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of 1438 * 1439 * Increments &drm_dp_mst_branch.malloc_kref. When 1440 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb 1441 * will be released and @mstb may no longer be used. 1442 * 1443 * See also: drm_dp_mst_put_mstb_malloc() 1444 */ 1445static void 1446drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb) 1447{ 1448 kref_get(&mstb->malloc_kref); 1449 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref)); 1450} 1451 1452/** 1453 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch 1454 * device 1455 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of 1456 * 1457 * Decrements &drm_dp_mst_branch.malloc_kref. When 1458 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb 1459 * will be released and @mstb may no longer be used. 1460 * 1461 * See also: drm_dp_mst_get_mstb_malloc() 1462 */ 1463static void 1464drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb) 1465{ 1466 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1); 1467 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device); 1468} 1469 1470static void drm_dp_free_mst_port(struct kref *kref) 1471{ 1472 struct drm_dp_mst_port *port = 1473 container_of(kref, struct drm_dp_mst_port, malloc_kref); 1474 1475 drm_dp_mst_put_mstb_malloc(port->parent); 1476 kfree(port); 1477} 1478 1479/** 1480 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port 1481 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of 1482 * 1483 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref 1484 * reaches 0, the memory allocation for @port will be released and @port may 1485 * no longer be used. 1486 * 1487 * Because @port could potentially be freed at any time by the DP MST helpers 1488 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this 1489 * function, drivers that which to make use of &struct drm_dp_mst_port should 1490 * ensure that they grab at least one main malloc reference to their MST ports 1491 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before 1492 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0. 1493 * 1494 * See also: drm_dp_mst_put_port_malloc() 1495 */ 1496void 1497drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port) 1498{ 1499 kref_get(&port->malloc_kref); 1500 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref)); 1501} 1502EXPORT_SYMBOL(drm_dp_mst_get_port_malloc); 1503 1504/** 1505 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port 1506 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of 1507 * 1508 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref 1509 * reaches 0, the memory allocation for @port will be released and @port may 1510 * no longer be used. 1511 * 1512 * See also: drm_dp_mst_get_port_malloc() 1513 */ 1514void 1515drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port) 1516{ 1517 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1); 1518 kref_put(&port->malloc_kref, drm_dp_free_mst_port); 1519} 1520EXPORT_SYMBOL(drm_dp_mst_put_port_malloc); 1521 1522#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 1523 1524#define STACK_DEPTH 8 1525 1526static noinline void 1527__topology_ref_save(struct drm_dp_mst_topology_mgr *mgr, 1528 struct drm_dp_mst_topology_ref_history *history, 1529 enum drm_dp_mst_topology_ref_type type) 1530{ 1531 struct drm_dp_mst_topology_ref_entry *entry = NULL; 1532 depot_stack_handle_t backtrace; 1533 ulong stack_entries[STACK_DEPTH]; 1534 uint n; 1535 int i; 1536 1537 n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1); 1538 backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL); 1539 if (!backtrace) 1540 return; 1541 1542 /* Try to find an existing entry for this backtrace */ 1543 for (i = 0; i < history->len; i++) { 1544 if (history->entries[i].backtrace == backtrace) { 1545 entry = &history->entries[i]; 1546 break; 1547 } 1548 } 1549 1550 /* Otherwise add one */ 1551 if (!entry) { 1552 struct drm_dp_mst_topology_ref_entry *new; 1553 int new_len = history->len + 1; 1554 1555 new = krealloc(history->entries, sizeof(*new) * new_len, 1556 GFP_KERNEL); 1557 if (!new) 1558 return; 1559 1560 entry = &new[history->len]; 1561 history->len = new_len; 1562 history->entries = new; 1563 1564 entry->backtrace = backtrace; 1565 entry->type = type; 1566 entry->count = 0; 1567 } 1568 entry->count++; 1569 entry->ts_nsec = ktime_get_ns(); 1570} 1571 1572static int 1573topology_ref_history_cmp(const void *a, const void *b) 1574{ 1575 const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b; 1576 1577 if (entry_a->ts_nsec > entry_b->ts_nsec) 1578 return 1; 1579 else if (entry_a->ts_nsec < entry_b->ts_nsec) 1580 return -1; 1581 else 1582 return 0; 1583} 1584 1585static inline const char * 1586topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type) 1587{ 1588 if (type == DRM_DP_MST_TOPOLOGY_REF_GET) 1589 return "get"; 1590 else 1591 return "put"; 1592} 1593 1594static void 1595__dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history, 1596 void *ptr, const char *type_str) 1597{ 1598 struct drm_printer p = drm_debug_printer(DBG_PREFIX); 1599 char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL); 1600 int i; 1601 1602 if (!buf) 1603 return; 1604 1605 if (!history->len) 1606 goto out; 1607 1608 /* First, sort the list so that it goes from oldest to newest 1609 * reference entry 1610 */ 1611 sort(history->entries, history->len, sizeof(*history->entries), 1612 topology_ref_history_cmp, NULL); 1613 1614 drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n", 1615 type_str, ptr); 1616 1617 for (i = 0; i < history->len; i++) { 1618 const struct drm_dp_mst_topology_ref_entry *entry = 1619 &history->entries[i]; 1620 u64 ts_nsec = entry->ts_nsec; 1621 u32 rem_nsec = do_div(ts_nsec, 1000000000); 1622 1623 stack_depot_snprint(entry->backtrace, buf, PAGE_SIZE, 4); 1624 1625 drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s", 1626 entry->count, 1627 topology_ref_type_to_str(entry->type), 1628 ts_nsec, rem_nsec / 1000, buf); 1629 } 1630 1631 /* Now free the history, since this is the only time we expose it */ 1632 kfree(history->entries); 1633out: 1634 kfree(buf); 1635} 1636 1637static __always_inline void 1638drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) 1639{ 1640 __dump_topology_ref_history(&mstb->topology_ref_history, mstb, 1641 "MSTB"); 1642} 1643 1644static __always_inline void 1645drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) 1646{ 1647 __dump_topology_ref_history(&port->topology_ref_history, port, 1648 "Port"); 1649} 1650 1651static __always_inline void 1652save_mstb_topology_ref(struct drm_dp_mst_branch *mstb, 1653 enum drm_dp_mst_topology_ref_type type) 1654{ 1655 __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type); 1656} 1657 1658static __always_inline void 1659save_port_topology_ref(struct drm_dp_mst_port *port, 1660 enum drm_dp_mst_topology_ref_type type) 1661{ 1662 __topology_ref_save(port->mgr, &port->topology_ref_history, type); 1663} 1664 1665static inline void 1666topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) 1667{ 1668 mutex_lock(&mgr->topology_ref_history_lock); 1669} 1670 1671static inline void 1672topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) 1673{ 1674 mutex_unlock(&mgr->topology_ref_history_lock); 1675} 1676#else 1677static inline void 1678topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {} 1679static inline void 1680topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {} 1681static inline void 1682drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {} 1683static inline void 1684drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {} 1685#define save_mstb_topology_ref(mstb, type) 1686#define save_port_topology_ref(port, type) 1687#endif 1688 1689struct drm_dp_mst_atomic_payload * 1690drm_atomic_get_mst_payload_state(struct drm_dp_mst_topology_state *state, 1691 struct drm_dp_mst_port *port) 1692{ 1693 struct drm_dp_mst_atomic_payload *payload; 1694 1695 list_for_each_entry(payload, &state->payloads, next) 1696 if (payload->port == port) 1697 return payload; 1698 1699 return NULL; 1700} 1701EXPORT_SYMBOL(drm_atomic_get_mst_payload_state); 1702 1703static void drm_dp_destroy_mst_branch_device(struct kref *kref) 1704{ 1705 struct drm_dp_mst_branch *mstb = 1706 container_of(kref, struct drm_dp_mst_branch, topology_kref); 1707 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 1708 1709 drm_dp_mst_dump_mstb_topology_history(mstb); 1710 1711 INIT_LIST_HEAD(&mstb->destroy_next); 1712 1713 /* 1714 * This can get called under mgr->mutex, so we need to perform the 1715 * actual destruction of the mstb in another worker 1716 */ 1717 mutex_lock(&mgr->delayed_destroy_lock); 1718 list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list); 1719 mutex_unlock(&mgr->delayed_destroy_lock); 1720 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work); 1721} 1722 1723/** 1724 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a 1725 * branch device unless it's zero 1726 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of 1727 * 1728 * Attempts to grab a topology reference to @mstb, if it hasn't yet been 1729 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has 1730 * reached 0). Holding a topology reference implies that a malloc reference 1731 * will be held to @mstb as long as the user holds the topology reference. 1732 * 1733 * Care should be taken to ensure that the user has at least one malloc 1734 * reference to @mstb. If you already have a topology reference to @mstb, you 1735 * should use drm_dp_mst_topology_get_mstb() instead. 1736 * 1737 * See also: 1738 * drm_dp_mst_topology_get_mstb() 1739 * drm_dp_mst_topology_put_mstb() 1740 * 1741 * Returns: 1742 * * 1: A topology reference was grabbed successfully 1743 * * 0: @port is no longer in the topology, no reference was grabbed 1744 */ 1745static int __must_check 1746drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb) 1747{ 1748 int ret; 1749 1750 topology_ref_history_lock(mstb->mgr); 1751 ret = kref_get_unless_zero(&mstb->topology_kref); 1752 if (ret) { 1753 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref)); 1754 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET); 1755 } 1756 1757 topology_ref_history_unlock(mstb->mgr); 1758 1759 return ret; 1760} 1761 1762/** 1763 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a 1764 * branch device 1765 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of 1766 * 1767 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or 1768 * not it's already reached 0. This is only valid to use in scenarios where 1769 * you are already guaranteed to have at least one active topology reference 1770 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used. 1771 * 1772 * See also: 1773 * drm_dp_mst_topology_try_get_mstb() 1774 * drm_dp_mst_topology_put_mstb() 1775 */ 1776static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb) 1777{ 1778 topology_ref_history_lock(mstb->mgr); 1779 1780 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET); 1781 WARN_ON(kref_read(&mstb->topology_kref) == 0); 1782 kref_get(&mstb->topology_kref); 1783 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref)); 1784 1785 topology_ref_history_unlock(mstb->mgr); 1786} 1787 1788/** 1789 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch 1790 * device 1791 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from 1792 * 1793 * Releases a topology reference from @mstb by decrementing 1794 * &drm_dp_mst_branch.topology_kref. 1795 * 1796 * See also: 1797 * drm_dp_mst_topology_try_get_mstb() 1798 * drm_dp_mst_topology_get_mstb() 1799 */ 1800static void 1801drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb) 1802{ 1803 topology_ref_history_lock(mstb->mgr); 1804 1805 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref) - 1); 1806 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT); 1807 1808 topology_ref_history_unlock(mstb->mgr); 1809 kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device); 1810} 1811 1812static void drm_dp_destroy_port(struct kref *kref) 1813{ 1814 struct drm_dp_mst_port *port = 1815 container_of(kref, struct drm_dp_mst_port, topology_kref); 1816 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 1817 1818 drm_dp_mst_dump_port_topology_history(port); 1819 1820 /* There's nothing that needs locking to destroy an input port yet */ 1821 if (port->input) { 1822 drm_dp_mst_put_port_malloc(port); 1823 return; 1824 } 1825 1826 kfree(port->cached_edid); 1827 1828 /* 1829 * we can't destroy the connector here, as we might be holding the 1830 * mode_config.mutex from an EDID retrieval 1831 */ 1832 mutex_lock(&mgr->delayed_destroy_lock); 1833 list_add(&port->next, &mgr->destroy_port_list); 1834 mutex_unlock(&mgr->delayed_destroy_lock); 1835 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work); 1836} 1837 1838/** 1839 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a 1840 * port unless it's zero 1841 * @port: &struct drm_dp_mst_port to increment the topology refcount of 1842 * 1843 * Attempts to grab a topology reference to @port, if it hasn't yet been 1844 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached 1845 * 0). Holding a topology reference implies that a malloc reference will be 1846 * held to @port as long as the user holds the topology reference. 1847 * 1848 * Care should be taken to ensure that the user has at least one malloc 1849 * reference to @port. If you already have a topology reference to @port, you 1850 * should use drm_dp_mst_topology_get_port() instead. 1851 * 1852 * See also: 1853 * drm_dp_mst_topology_get_port() 1854 * drm_dp_mst_topology_put_port() 1855 * 1856 * Returns: 1857 * * 1: A topology reference was grabbed successfully 1858 * * 0: @port is no longer in the topology, no reference was grabbed 1859 */ 1860static int __must_check 1861drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port) 1862{ 1863 int ret; 1864 1865 topology_ref_history_lock(port->mgr); 1866 ret = kref_get_unless_zero(&port->topology_kref); 1867 if (ret) { 1868 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref)); 1869 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET); 1870 } 1871 1872 topology_ref_history_unlock(port->mgr); 1873 return ret; 1874} 1875 1876/** 1877 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port 1878 * @port: The &struct drm_dp_mst_port to increment the topology refcount of 1879 * 1880 * Increments &drm_dp_mst_port.topology_refcount without checking whether or 1881 * not it's already reached 0. This is only valid to use in scenarios where 1882 * you are already guaranteed to have at least one active topology reference 1883 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used. 1884 * 1885 * See also: 1886 * drm_dp_mst_topology_try_get_port() 1887 * drm_dp_mst_topology_put_port() 1888 */ 1889static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port) 1890{ 1891 topology_ref_history_lock(port->mgr); 1892 1893 WARN_ON(kref_read(&port->topology_kref) == 0); 1894 kref_get(&port->topology_kref); 1895 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref)); 1896 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET); 1897 1898 topology_ref_history_unlock(port->mgr); 1899} 1900 1901/** 1902 * drm_dp_mst_topology_put_port() - release a topology reference to a port 1903 * @port: The &struct drm_dp_mst_port to release the topology reference from 1904 * 1905 * Releases a topology reference from @port by decrementing 1906 * &drm_dp_mst_port.topology_kref. 1907 * 1908 * See also: 1909 * drm_dp_mst_topology_try_get_port() 1910 * drm_dp_mst_topology_get_port() 1911 */ 1912static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port) 1913{ 1914 topology_ref_history_lock(port->mgr); 1915 1916 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref) - 1); 1917 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT); 1918 1919 topology_ref_history_unlock(port->mgr); 1920 kref_put(&port->topology_kref, drm_dp_destroy_port); 1921} 1922 1923static struct drm_dp_mst_branch * 1924drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb, 1925 struct drm_dp_mst_branch *to_find) 1926{ 1927 struct drm_dp_mst_port *port; 1928 struct drm_dp_mst_branch *rmstb; 1929 1930 if (to_find == mstb) 1931 return mstb; 1932 1933 list_for_each_entry(port, &mstb->ports, next) { 1934 if (port->mstb) { 1935 rmstb = drm_dp_mst_topology_get_mstb_validated_locked( 1936 port->mstb, to_find); 1937 if (rmstb) 1938 return rmstb; 1939 } 1940 } 1941 return NULL; 1942} 1943 1944static struct drm_dp_mst_branch * 1945drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr, 1946 struct drm_dp_mst_branch *mstb) 1947{ 1948 struct drm_dp_mst_branch *rmstb = NULL; 1949 1950 mutex_lock(&mgr->lock); 1951 if (mgr->mst_primary) { 1952 rmstb = drm_dp_mst_topology_get_mstb_validated_locked( 1953 mgr->mst_primary, mstb); 1954 1955 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb)) 1956 rmstb = NULL; 1957 } 1958 mutex_unlock(&mgr->lock); 1959 return rmstb; 1960} 1961 1962static struct drm_dp_mst_port * 1963drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb, 1964 struct drm_dp_mst_port *to_find) 1965{ 1966 struct drm_dp_mst_port *port, *mport; 1967 1968 list_for_each_entry(port, &mstb->ports, next) { 1969 if (port == to_find) 1970 return port; 1971 1972 if (port->mstb) { 1973 mport = drm_dp_mst_topology_get_port_validated_locked( 1974 port->mstb, to_find); 1975 if (mport) 1976 return mport; 1977 } 1978 } 1979 return NULL; 1980} 1981 1982static struct drm_dp_mst_port * 1983drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr, 1984 struct drm_dp_mst_port *port) 1985{ 1986 struct drm_dp_mst_port *rport = NULL; 1987 1988 mutex_lock(&mgr->lock); 1989 if (mgr->mst_primary) { 1990 rport = drm_dp_mst_topology_get_port_validated_locked( 1991 mgr->mst_primary, port); 1992 1993 if (rport && !drm_dp_mst_topology_try_get_port(rport)) 1994 rport = NULL; 1995 } 1996 mutex_unlock(&mgr->lock); 1997 return rport; 1998} 1999 2000static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num) 2001{ 2002 struct drm_dp_mst_port *port; 2003 int ret; 2004 2005 list_for_each_entry(port, &mstb->ports, next) { 2006 if (port->port_num == port_num) { 2007 ret = drm_dp_mst_topology_try_get_port(port); 2008 return ret ? port : NULL; 2009 } 2010 } 2011 2012 return NULL; 2013} 2014 2015/* 2016 * calculate a new RAD for this MST branch device 2017 * if parent has an LCT of 2 then it has 1 nibble of RAD, 2018 * if parent has an LCT of 3 then it has 2 nibbles of RAD, 2019 */ 2020static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port, 2021 u8 *rad) 2022{ 2023 int parent_lct = port->parent->lct; 2024 int shift = 4; 2025 int idx = (parent_lct - 1) / 2; 2026 2027 if (parent_lct > 1) { 2028 memcpy(rad, port->parent->rad, idx + 1); 2029 shift = (parent_lct % 2) ? 4 : 0; 2030 } else 2031 rad[0] = 0; 2032 2033 rad[idx] |= port->port_num << shift; 2034 return parent_lct + 1; 2035} 2036 2037static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs) 2038{ 2039 switch (pdt) { 2040 case DP_PEER_DEVICE_DP_LEGACY_CONV: 2041 case DP_PEER_DEVICE_SST_SINK: 2042 return true; 2043 case DP_PEER_DEVICE_MST_BRANCHING: 2044 /* For sst branch device */ 2045 if (!mcs) 2046 return true; 2047 2048 return false; 2049 } 2050 return true; 2051} 2052 2053static int 2054drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt, 2055 bool new_mcs) 2056{ 2057 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 2058 struct drm_dp_mst_branch *mstb; 2059 u8 rad[8], lct; 2060 int ret = 0; 2061 2062 if (port->pdt == new_pdt && port->mcs == new_mcs) 2063 return 0; 2064 2065 /* Teardown the old pdt, if there is one */ 2066 if (port->pdt != DP_PEER_DEVICE_NONE) { 2067 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { 2068 /* 2069 * If the new PDT would also have an i2c bus, 2070 * don't bother with reregistering it 2071 */ 2072 if (new_pdt != DP_PEER_DEVICE_NONE && 2073 drm_dp_mst_is_end_device(new_pdt, new_mcs)) { 2074 port->pdt = new_pdt; 2075 port->mcs = new_mcs; 2076 return 0; 2077 } 2078 2079 /* remove i2c over sideband */ 2080 drm_dp_mst_unregister_i2c_bus(port); 2081 } else { 2082 mutex_lock(&mgr->lock); 2083 drm_dp_mst_topology_put_mstb(port->mstb); 2084 port->mstb = NULL; 2085 mutex_unlock(&mgr->lock); 2086 } 2087 } 2088 2089 port->pdt = new_pdt; 2090 port->mcs = new_mcs; 2091 2092 if (port->pdt != DP_PEER_DEVICE_NONE) { 2093 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { 2094 /* add i2c over sideband */ 2095 ret = drm_dp_mst_register_i2c_bus(port); 2096 } else { 2097 lct = drm_dp_calculate_rad(port, rad); 2098 mstb = drm_dp_add_mst_branch_device(lct, rad); 2099 if (!mstb) { 2100 ret = -ENOMEM; 2101 drm_err(mgr->dev, "Failed to create MSTB for port %p", port); 2102 goto out; 2103 } 2104 2105 mutex_lock(&mgr->lock); 2106 port->mstb = mstb; 2107 mstb->mgr = port->mgr; 2108 mstb->port_parent = port; 2109 2110 /* 2111 * Make sure this port's memory allocation stays 2112 * around until its child MSTB releases it 2113 */ 2114 drm_dp_mst_get_port_malloc(port); 2115 mutex_unlock(&mgr->lock); 2116 2117 /* And make sure we send a link address for this */ 2118 ret = 1; 2119 } 2120 } 2121 2122out: 2123 if (ret < 0) 2124 port->pdt = DP_PEER_DEVICE_NONE; 2125 return ret; 2126} 2127 2128/** 2129 * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband 2130 * @aux: Fake sideband AUX CH 2131 * @offset: address of the (first) register to read 2132 * @buffer: buffer to store the register values 2133 * @size: number of bytes in @buffer 2134 * 2135 * Performs the same functionality for remote devices via 2136 * sideband messaging as drm_dp_dpcd_read() does for local 2137 * devices via actual AUX CH. 2138 * 2139 * Return: Number of bytes read, or negative error code on failure. 2140 */ 2141ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux, 2142 unsigned int offset, void *buffer, size_t size) 2143{ 2144 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, 2145 aux); 2146 2147 return drm_dp_send_dpcd_read(port->mgr, port, 2148 offset, size, buffer); 2149} 2150 2151/** 2152 * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband 2153 * @aux: Fake sideband AUX CH 2154 * @offset: address of the (first) register to write 2155 * @buffer: buffer containing the values to write 2156 * @size: number of bytes in @buffer 2157 * 2158 * Performs the same functionality for remote devices via 2159 * sideband messaging as drm_dp_dpcd_write() does for local 2160 * devices via actual AUX CH. 2161 * 2162 * Return: number of bytes written on success, negative error code on failure. 2163 */ 2164ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux, 2165 unsigned int offset, void *buffer, size_t size) 2166{ 2167 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, 2168 aux); 2169 2170 return drm_dp_send_dpcd_write(port->mgr, port, 2171 offset, size, buffer); 2172} 2173 2174static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid) 2175{ 2176 int ret = 0; 2177 2178 memcpy(mstb->guid, guid, 16); 2179 2180 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) { 2181 if (mstb->port_parent) { 2182 ret = drm_dp_send_dpcd_write(mstb->mgr, 2183 mstb->port_parent, 2184 DP_GUID, 16, mstb->guid); 2185 } else { 2186 ret = drm_dp_dpcd_write(mstb->mgr->aux, 2187 DP_GUID, mstb->guid, 16); 2188 } 2189 } 2190 2191 if (ret < 16 && ret > 0) 2192 return -EPROTO; 2193 2194 return ret == 16 ? 0 : ret; 2195} 2196 2197static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb, 2198 int pnum, 2199 char *proppath, 2200 size_t proppath_size) 2201{ 2202 int i; 2203 char temp[8]; 2204 2205 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id); 2206 for (i = 0; i < (mstb->lct - 1); i++) { 2207 int shift = (i % 2) ? 0 : 4; 2208 int port_num = (mstb->rad[i / 2] >> shift) & 0xf; 2209 2210 snprintf(temp, sizeof(temp), "-%d", port_num); 2211 strlcat(proppath, temp, proppath_size); 2212 } 2213 snprintf(temp, sizeof(temp), "-%d", pnum); 2214 strlcat(proppath, temp, proppath_size); 2215} 2216 2217/** 2218 * drm_dp_mst_connector_late_register() - Late MST connector registration 2219 * @connector: The MST connector 2220 * @port: The MST port for this connector 2221 * 2222 * Helper to register the remote aux device for this MST port. Drivers should 2223 * call this from their mst connector's late_register hook to enable MST aux 2224 * devices. 2225 * 2226 * Return: 0 on success, negative error code on failure. 2227 */ 2228int drm_dp_mst_connector_late_register(struct drm_connector *connector, 2229 struct drm_dp_mst_port *port) 2230{ 2231#ifdef __linux__ 2232 drm_dbg_kms(port->mgr->dev, "registering %s remote bus for %s\n", 2233 port->aux.name, connector->kdev->kobj.name); 2234#else 2235 drm_dbg_kms(port->mgr->dev, "registering %s remote bus\n", 2236 port->aux.name); 2237#endif 2238 2239 port->aux.dev = connector->kdev; 2240 return drm_dp_aux_register_devnode(&port->aux); 2241} 2242EXPORT_SYMBOL(drm_dp_mst_connector_late_register); 2243 2244/** 2245 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration 2246 * @connector: The MST connector 2247 * @port: The MST port for this connector 2248 * 2249 * Helper to unregister the remote aux device for this MST port, registered by 2250 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst 2251 * connector's early_unregister hook. 2252 */ 2253void drm_dp_mst_connector_early_unregister(struct drm_connector *connector, 2254 struct drm_dp_mst_port *port) 2255{ 2256#ifdef __linux__ 2257 drm_dbg_kms(port->mgr->dev, "unregistering %s remote bus for %s\n", 2258 port->aux.name, connector->kdev->kobj.name); 2259#else 2260 drm_dbg_kms(port->mgr->dev, "unregistering %s remote bus\n", 2261 port->aux.name); 2262#endif 2263 drm_dp_aux_unregister_devnode(&port->aux); 2264} 2265EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister); 2266 2267static void 2268drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb, 2269 struct drm_dp_mst_port *port) 2270{ 2271 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 2272 char proppath[255]; 2273 int ret; 2274 2275 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath)); 2276 port->connector = mgr->cbs->add_connector(mgr, port, proppath); 2277 if (!port->connector) { 2278 ret = -ENOMEM; 2279 goto error; 2280 } 2281 2282 if (port->pdt != DP_PEER_DEVICE_NONE && 2283 drm_dp_mst_is_end_device(port->pdt, port->mcs) && 2284 port->port_num >= DP_MST_LOGICAL_PORT_0) 2285 port->cached_edid = drm_get_edid(port->connector, 2286 &port->aux.ddc); 2287 2288 drm_connector_register(port->connector); 2289 return; 2290 2291error: 2292 drm_err(mgr->dev, "Failed to create connector for port %p: %d\n", port, ret); 2293} 2294 2295/* 2296 * Drop a topology reference, and unlink the port from the in-memory topology 2297 * layout 2298 */ 2299static void 2300drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr, 2301 struct drm_dp_mst_port *port) 2302{ 2303 mutex_lock(&mgr->lock); 2304 port->parent->num_ports--; 2305 list_del(&port->next); 2306 mutex_unlock(&mgr->lock); 2307 drm_dp_mst_topology_put_port(port); 2308} 2309 2310static struct drm_dp_mst_port * 2311drm_dp_mst_add_port(struct drm_device *dev, 2312 struct drm_dp_mst_topology_mgr *mgr, 2313 struct drm_dp_mst_branch *mstb, u8 port_number) 2314{ 2315 struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL); 2316 2317 if (!port) 2318 return NULL; 2319 2320 kref_init(&port->topology_kref); 2321 kref_init(&port->malloc_kref); 2322 port->parent = mstb; 2323 port->port_num = port_number; 2324 port->mgr = mgr; 2325 port->aux.name = "DPMST"; 2326 port->aux.dev = dev->dev; 2327 port->aux.is_remote = true; 2328 2329 /* initialize the MST downstream port's AUX crc work queue */ 2330 port->aux.drm_dev = dev; 2331 drm_dp_remote_aux_init(&port->aux); 2332 2333 /* 2334 * Make sure the memory allocation for our parent branch stays 2335 * around until our own memory allocation is released 2336 */ 2337 drm_dp_mst_get_mstb_malloc(mstb); 2338 2339 return port; 2340} 2341 2342static int 2343drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb, 2344 struct drm_device *dev, 2345 struct drm_dp_link_addr_reply_port *port_msg) 2346{ 2347 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 2348 struct drm_dp_mst_port *port; 2349 int old_ddps = 0, ret; 2350 u8 new_pdt = DP_PEER_DEVICE_NONE; 2351 bool new_mcs = 0; 2352 bool created = false, send_link_addr = false, changed = false; 2353 2354 port = drm_dp_get_port(mstb, port_msg->port_number); 2355 if (!port) { 2356 port = drm_dp_mst_add_port(dev, mgr, mstb, 2357 port_msg->port_number); 2358 if (!port) 2359 return -ENOMEM; 2360 created = true; 2361 changed = true; 2362 } else if (!port->input && port_msg->input_port && port->connector) { 2363 /* Since port->connector can't be changed here, we create a 2364 * new port if input_port changes from 0 to 1 2365 */ 2366 drm_dp_mst_topology_unlink_port(mgr, port); 2367 drm_dp_mst_topology_put_port(port); 2368 port = drm_dp_mst_add_port(dev, mgr, mstb, 2369 port_msg->port_number); 2370 if (!port) 2371 return -ENOMEM; 2372 changed = true; 2373 created = true; 2374 } else if (port->input && !port_msg->input_port) { 2375 changed = true; 2376 } else if (port->connector) { 2377 /* We're updating a port that's exposed to userspace, so do it 2378 * under lock 2379 */ 2380 drm_modeset_lock(&mgr->base.lock, NULL); 2381 2382 old_ddps = port->ddps; 2383 changed = port->ddps != port_msg->ddps || 2384 (port->ddps && 2385 (port->ldps != port_msg->legacy_device_plug_status || 2386 port->dpcd_rev != port_msg->dpcd_revision || 2387 port->mcs != port_msg->mcs || 2388 port->pdt != port_msg->peer_device_type || 2389 port->num_sdp_stream_sinks != 2390 port_msg->num_sdp_stream_sinks)); 2391 } 2392 2393 port->input = port_msg->input_port; 2394 if (!port->input) 2395 new_pdt = port_msg->peer_device_type; 2396 new_mcs = port_msg->mcs; 2397 port->ddps = port_msg->ddps; 2398 port->ldps = port_msg->legacy_device_plug_status; 2399 port->dpcd_rev = port_msg->dpcd_revision; 2400 port->num_sdp_streams = port_msg->num_sdp_streams; 2401 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks; 2402 2403 /* manage mstb port lists with mgr lock - take a reference 2404 for this list */ 2405 if (created) { 2406 mutex_lock(&mgr->lock); 2407 drm_dp_mst_topology_get_port(port); 2408 list_add(&port->next, &mstb->ports); 2409 mstb->num_ports++; 2410 mutex_unlock(&mgr->lock); 2411 } 2412 2413 /* 2414 * Reprobe PBN caps on both hotplug, and when re-probing the link 2415 * for our parent mstb 2416 */ 2417 if (old_ddps != port->ddps || !created) { 2418 if (port->ddps && !port->input) { 2419 ret = drm_dp_send_enum_path_resources(mgr, mstb, 2420 port); 2421 if (ret == 1) 2422 changed = true; 2423 } else { 2424 port->full_pbn = 0; 2425 } 2426 } 2427 2428 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs); 2429 if (ret == 1) { 2430 send_link_addr = true; 2431 } else if (ret < 0) { 2432 drm_err(dev, "Failed to change PDT on port %p: %d\n", port, ret); 2433 goto fail; 2434 } 2435 2436 /* 2437 * If this port wasn't just created, then we're reprobing because 2438 * we're coming out of suspend. In this case, always resend the link 2439 * address if there's an MSTB on this port 2440 */ 2441 if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING && 2442 port->mcs) 2443 send_link_addr = true; 2444 2445 if (port->connector) 2446 drm_modeset_unlock(&mgr->base.lock); 2447 else if (!port->input) 2448 drm_dp_mst_port_add_connector(mstb, port); 2449 2450 if (send_link_addr && port->mstb) { 2451 ret = drm_dp_send_link_address(mgr, port->mstb); 2452 if (ret == 1) /* MSTB below us changed */ 2453 changed = true; 2454 else if (ret < 0) 2455 goto fail_put; 2456 } 2457 2458 /* put reference to this port */ 2459 drm_dp_mst_topology_put_port(port); 2460 return changed; 2461 2462fail: 2463 drm_dp_mst_topology_unlink_port(mgr, port); 2464 if (port->connector) 2465 drm_modeset_unlock(&mgr->base.lock); 2466fail_put: 2467 drm_dp_mst_topology_put_port(port); 2468 return ret; 2469} 2470 2471static int 2472drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb, 2473 struct drm_dp_connection_status_notify *conn_stat) 2474{ 2475 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 2476 struct drm_dp_mst_port *port; 2477 int old_ddps, ret; 2478 u8 new_pdt; 2479 bool new_mcs; 2480 bool dowork = false, create_connector = false; 2481 2482 port = drm_dp_get_port(mstb, conn_stat->port_number); 2483 if (!port) 2484 return 0; 2485 2486 if (port->connector) { 2487 if (!port->input && conn_stat->input_port) { 2488 /* 2489 * We can't remove a connector from an already exposed 2490 * port, so just throw the port out and make sure we 2491 * reprobe the link address of it's parent MSTB 2492 */ 2493 drm_dp_mst_topology_unlink_port(mgr, port); 2494 mstb->link_address_sent = false; 2495 dowork = true; 2496 goto out; 2497 } 2498 2499 /* Locking is only needed if the port's exposed to userspace */ 2500 drm_modeset_lock(&mgr->base.lock, NULL); 2501 } else if (port->input && !conn_stat->input_port) { 2502 create_connector = true; 2503 /* Reprobe link address so we get num_sdp_streams */ 2504 mstb->link_address_sent = false; 2505 dowork = true; 2506 } 2507 2508 old_ddps = port->ddps; 2509 port->input = conn_stat->input_port; 2510 port->ldps = conn_stat->legacy_device_plug_status; 2511 port->ddps = conn_stat->displayport_device_plug_status; 2512 2513 if (old_ddps != port->ddps) { 2514 if (port->ddps && !port->input) 2515 drm_dp_send_enum_path_resources(mgr, mstb, port); 2516 else 2517 port->full_pbn = 0; 2518 } 2519 2520 new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type; 2521 new_mcs = conn_stat->message_capability_status; 2522 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs); 2523 if (ret == 1) { 2524 dowork = true; 2525 } else if (ret < 0) { 2526 drm_err(mgr->dev, "Failed to change PDT for port %p: %d\n", port, ret); 2527 dowork = false; 2528 } 2529 2530 if (port->connector) 2531 drm_modeset_unlock(&mgr->base.lock); 2532 else if (create_connector) 2533 drm_dp_mst_port_add_connector(mstb, port); 2534 2535out: 2536 drm_dp_mst_topology_put_port(port); 2537 return dowork; 2538} 2539 2540static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr, 2541 u8 lct, u8 *rad) 2542{ 2543 struct drm_dp_mst_branch *mstb; 2544 struct drm_dp_mst_port *port; 2545 int i, ret; 2546 /* find the port by iterating down */ 2547 2548 mutex_lock(&mgr->lock); 2549 mstb = mgr->mst_primary; 2550 2551 if (!mstb) 2552 goto out; 2553 2554 for (i = 0; i < lct - 1; i++) { 2555 int shift = (i % 2) ? 0 : 4; 2556 int port_num = (rad[i / 2] >> shift) & 0xf; 2557 2558 list_for_each_entry(port, &mstb->ports, next) { 2559 if (port->port_num == port_num) { 2560 mstb = port->mstb; 2561 if (!mstb) { 2562 drm_err(mgr->dev, 2563 "failed to lookup MSTB with lct %d, rad %02x\n", 2564 lct, rad[0]); 2565 goto out; 2566 } 2567 2568 break; 2569 } 2570 } 2571 } 2572 ret = drm_dp_mst_topology_try_get_mstb(mstb); 2573 if (!ret) 2574 mstb = NULL; 2575out: 2576 mutex_unlock(&mgr->lock); 2577 return mstb; 2578} 2579 2580static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper( 2581 struct drm_dp_mst_branch *mstb, 2582 const uint8_t *guid) 2583{ 2584 struct drm_dp_mst_branch *found_mstb; 2585 struct drm_dp_mst_port *port; 2586 2587 if (memcmp(mstb->guid, guid, 16) == 0) 2588 return mstb; 2589 2590 2591 list_for_each_entry(port, &mstb->ports, next) { 2592 if (!port->mstb) 2593 continue; 2594 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 uint8_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 bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, 2703 u8 *guid) 2704{ 2705 u64 salt; 2706 2707 if (memchr_inv(guid, 0, 16)) 2708 return true; 2709 2710 salt = get_jiffies_64(); 2711 2712 memcpy(&guid[0], &salt, sizeof(u64)); 2713 memcpy(&guid[8], &salt, sizeof(u64)); 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(mgr->aux, regbase + offset, 2745 &msg[offset], 2746 tosend); 2747 if (ret != tosend) { 2748 if (ret == -EIO && retries < 5) { 2749 retries++; 2750 goto retry; 2751 } 2752 drm_dbg_kms(mgr->dev, "failed to dpcd write %d %d\n", tosend, ret); 2753 2754 return -EIO; 2755 } 2756 offset += tosend; 2757 total -= tosend; 2758 } while (total > 0); 2759 return 0; 2760} 2761 2762static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr, 2763 struct drm_dp_sideband_msg_tx *txmsg) 2764{ 2765 struct drm_dp_mst_branch *mstb = txmsg->dst; 2766 u8 req_type; 2767 2768 req_type = txmsg->msg[0] & 0x7f; 2769 if (req_type == DP_CONNECTION_STATUS_NOTIFY || 2770 req_type == DP_RESOURCE_STATUS_NOTIFY || 2771 req_type == DP_CLEAR_PAYLOAD_ID_TABLE) 2772 hdr->broadcast = 1; 2773 else 2774 hdr->broadcast = 0; 2775 hdr->path_msg = txmsg->path_msg; 2776 if (hdr->broadcast) { 2777 hdr->lct = 1; 2778 hdr->lcr = 6; 2779 } else { 2780 hdr->lct = mstb->lct; 2781 hdr->lcr = mstb->lct - 1; 2782 } 2783 2784 memcpy(hdr->rad, mstb->rad, hdr->lct / 2); 2785 2786 return 0; 2787} 2788/* 2789 * process a single block of the next message in the sideband queue 2790 */ 2791static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr, 2792 struct drm_dp_sideband_msg_tx *txmsg, 2793 bool up) 2794{ 2795 u8 chunk[48]; 2796 struct drm_dp_sideband_msg_hdr hdr; 2797 int len, space, idx, tosend; 2798 int ret; 2799 2800 if (txmsg->state == DRM_DP_SIDEBAND_TX_SENT) 2801 return 0; 2802 2803 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr)); 2804 2805 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) 2806 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND; 2807 2808 /* make hdr from dst mst */ 2809 ret = set_hdr_from_dst_qlock(&hdr, txmsg); 2810 if (ret < 0) 2811 return ret; 2812 2813 /* amount left to send in this message */ 2814 len = txmsg->cur_len - txmsg->cur_offset; 2815 2816 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */ 2817 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr); 2818 2819 tosend = min(len, space); 2820 if (len == txmsg->cur_len) 2821 hdr.somt = 1; 2822 if (space >= len) 2823 hdr.eomt = 1; 2824 2825 2826 hdr.msg_len = tosend + 1; 2827 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx); 2828 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend); 2829 /* add crc at end */ 2830 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend); 2831 idx += tosend + 1; 2832 2833 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx); 2834 if (ret) { 2835 if (drm_debug_enabled(DRM_UT_DP)) { 2836 struct drm_printer p = drm_debug_printer(DBG_PREFIX); 2837 2838 drm_printf(&p, "sideband msg failed to send\n"); 2839 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 2840 } 2841 return ret; 2842 } 2843 2844 txmsg->cur_offset += tosend; 2845 if (txmsg->cur_offset == txmsg->cur_len) { 2846 txmsg->state = DRM_DP_SIDEBAND_TX_SENT; 2847 return 1; 2848 } 2849 return 0; 2850} 2851 2852static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr) 2853{ 2854 struct drm_dp_sideband_msg_tx *txmsg; 2855 int ret; 2856 2857 WARN_ON(!mutex_is_locked(&mgr->qlock)); 2858 2859 /* construct a chunk from the first msg in the tx_msg queue */ 2860 if (list_empty(&mgr->tx_msg_downq)) 2861 return; 2862 2863 txmsg = list_first_entry(&mgr->tx_msg_downq, 2864 struct drm_dp_sideband_msg_tx, next); 2865 ret = process_single_tx_qlock(mgr, txmsg, false); 2866 if (ret < 0) { 2867 drm_dbg_kms(mgr->dev, "failed to send msg in q %d\n", ret); 2868 list_del(&txmsg->next); 2869 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 2870 wake_up_all(&mgr->tx_waitq); 2871 } 2872} 2873 2874static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr, 2875 struct drm_dp_sideband_msg_tx *txmsg) 2876{ 2877 mutex_lock(&mgr->qlock); 2878 list_add_tail(&txmsg->next, &mgr->tx_msg_downq); 2879 2880 if (drm_debug_enabled(DRM_UT_DP)) { 2881 struct drm_printer p = drm_debug_printer(DBG_PREFIX); 2882 2883 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 2884 } 2885 2886 if (list_is_singular(&mgr->tx_msg_downq)) 2887 process_single_down_tx_qlock(mgr); 2888 mutex_unlock(&mgr->qlock); 2889} 2890 2891static void 2892drm_dp_dump_link_address(const struct drm_dp_mst_topology_mgr *mgr, 2893 struct drm_dp_link_address_ack_reply *reply) 2894{ 2895 struct drm_dp_link_addr_reply_port *port_reply; 2896 int i; 2897 2898 for (i = 0; i < reply->nports; i++) { 2899 port_reply = &reply->ports[i]; 2900 drm_dbg_kms(mgr->dev, 2901 "port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", 2902 i, 2903 port_reply->input_port, 2904 port_reply->peer_device_type, 2905 port_reply->port_number, 2906 port_reply->dpcd_revision, 2907 port_reply->mcs, 2908 port_reply->ddps, 2909 port_reply->legacy_device_plug_status, 2910 port_reply->num_sdp_streams, 2911 port_reply->num_sdp_stream_sinks); 2912 } 2913} 2914 2915static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 2916 struct drm_dp_mst_branch *mstb) 2917{ 2918 struct drm_dp_sideband_msg_tx *txmsg; 2919 struct drm_dp_link_address_ack_reply *reply; 2920 struct drm_dp_mst_port *port, *tmp; 2921 int i, ret, port_mask = 0; 2922 bool changed = false; 2923 2924 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 2925 if (!txmsg) 2926 return -ENOMEM; 2927 2928 txmsg->dst = mstb; 2929 build_link_address(txmsg); 2930 2931 mstb->link_address_sent = true; 2932 drm_dp_queue_down_tx(mgr, txmsg); 2933 2934 /* FIXME: Actually do some real error handling here */ 2935 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 2936 if (ret <= 0) { 2937 drm_err(mgr->dev, "Sending link address failed with %d\n", ret); 2938 goto out; 2939 } 2940 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 2941 drm_err(mgr->dev, "link address NAK received\n"); 2942 ret = -EIO; 2943 goto out; 2944 } 2945 2946 reply = &txmsg->reply.u.link_addr; 2947 drm_dbg_kms(mgr->dev, "link address reply: %d\n", reply->nports); 2948 drm_dp_dump_link_address(mgr, reply); 2949 2950 ret = drm_dp_check_mstb_guid(mstb, reply->guid); 2951 if (ret) { 2952 char buf[64]; 2953 2954 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf)); 2955 drm_err(mgr->dev, "GUID check on %s failed: %d\n", buf, ret); 2956 goto out; 2957 } 2958 2959 for (i = 0; i < reply->nports; i++) { 2960 port_mask |= BIT(reply->ports[i].port_number); 2961 ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev, 2962 &reply->ports[i]); 2963 if (ret == 1) 2964 changed = true; 2965 else if (ret < 0) 2966 goto out; 2967 } 2968 2969 /* Prune any ports that are currently a part of mstb in our in-memory 2970 * topology, but were not seen in this link address. Usually this 2971 * means that they were removed while the topology was out of sync, 2972 * e.g. during suspend/resume 2973 */ 2974 mutex_lock(&mgr->lock); 2975 list_for_each_entry_safe(port, tmp, &mstb->ports, next) { 2976 if (port_mask & BIT(port->port_num)) 2977 continue; 2978 2979 drm_dbg_kms(mgr->dev, "port %d was not in link address, removing\n", 2980 port->port_num); 2981 list_del(&port->next); 2982 drm_dp_mst_topology_put_port(port); 2983 changed = true; 2984 } 2985 mutex_unlock(&mgr->lock); 2986 2987out: 2988 if (ret <= 0) 2989 mstb->link_address_sent = false; 2990 kfree(txmsg); 2991 return ret < 0 ? ret : changed; 2992} 2993 2994static void 2995drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr, 2996 struct drm_dp_mst_branch *mstb) 2997{ 2998 struct drm_dp_sideband_msg_tx *txmsg; 2999 int ret; 3000 3001 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3002 if (!txmsg) 3003 return; 3004 3005 txmsg->dst = mstb; 3006 build_clear_payload_id_table(txmsg); 3007 3008 drm_dp_queue_down_tx(mgr, txmsg); 3009 3010 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3011 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3012 drm_dbg_kms(mgr->dev, "clear payload table id nak received\n"); 3013 3014 kfree(txmsg); 3015} 3016 3017static int 3018drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, 3019 struct drm_dp_mst_branch *mstb, 3020 struct drm_dp_mst_port *port) 3021{ 3022 struct drm_dp_enum_path_resources_ack_reply *path_res; 3023 struct drm_dp_sideband_msg_tx *txmsg; 3024 int ret; 3025 3026 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3027 if (!txmsg) 3028 return -ENOMEM; 3029 3030 txmsg->dst = mstb; 3031 build_enum_path_resources(txmsg, port->port_num); 3032 3033 drm_dp_queue_down_tx(mgr, txmsg); 3034 3035 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3036 if (ret > 0) { 3037 ret = 0; 3038 path_res = &txmsg->reply.u.path_resources; 3039 3040 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3041 drm_dbg_kms(mgr->dev, "enum path resources nak received\n"); 3042 } else { 3043 if (port->port_num != path_res->port_number) 3044 DRM_ERROR("got incorrect port in response\n"); 3045 3046 drm_dbg_kms(mgr->dev, "enum path resources %d: %d %d\n", 3047 path_res->port_number, 3048 path_res->full_payload_bw_number, 3049 path_res->avail_payload_bw_number); 3050 3051 /* 3052 * If something changed, make sure we send a 3053 * hotplug 3054 */ 3055 if (port->full_pbn != path_res->full_payload_bw_number || 3056 port->fec_capable != path_res->fec_capable) 3057 ret = 1; 3058 3059 port->full_pbn = path_res->full_payload_bw_number; 3060 port->fec_capable = path_res->fec_capable; 3061 } 3062 } 3063 3064 kfree(txmsg); 3065 return ret; 3066} 3067 3068static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb) 3069{ 3070 if (!mstb->port_parent) 3071 return NULL; 3072 3073 if (mstb->port_parent->mstb != mstb) 3074 return mstb->port_parent; 3075 3076 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent); 3077} 3078 3079/* 3080 * Searches upwards in the topology starting from mstb to try to find the 3081 * closest available parent of mstb that's still connected to the rest of the 3082 * topology. This can be used in order to perform operations like releasing 3083 * payloads, where the branch device which owned the payload may no longer be 3084 * around and thus would require that the payload on the last living relative 3085 * be freed instead. 3086 */ 3087static struct drm_dp_mst_branch * 3088drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr, 3089 struct drm_dp_mst_branch *mstb, 3090 int *port_num) 3091{ 3092 struct drm_dp_mst_branch *rmstb = NULL; 3093 struct drm_dp_mst_port *found_port; 3094 3095 mutex_lock(&mgr->lock); 3096 if (!mgr->mst_primary) 3097 goto out; 3098 3099 do { 3100 found_port = drm_dp_get_last_connected_port_to_mstb(mstb); 3101 if (!found_port) 3102 break; 3103 3104 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) { 3105 rmstb = found_port->parent; 3106 *port_num = found_port->port_num; 3107 } else { 3108 /* Search again, starting from this parent */ 3109 mstb = found_port->parent; 3110 } 3111 } while (!rmstb); 3112out: 3113 mutex_unlock(&mgr->lock); 3114 return rmstb; 3115} 3116 3117static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr, 3118 struct drm_dp_mst_port *port, 3119 int id, 3120 int pbn) 3121{ 3122 struct drm_dp_sideband_msg_tx *txmsg; 3123 struct drm_dp_mst_branch *mstb; 3124 int ret, port_num; 3125 u8 sinks[DRM_DP_MAX_SDP_STREAMS]; 3126 int i; 3127 3128 port_num = port->port_num; 3129 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 3130 if (!mstb) { 3131 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, 3132 port->parent, 3133 &port_num); 3134 3135 if (!mstb) 3136 return -EINVAL; 3137 } 3138 3139 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3140 if (!txmsg) { 3141 ret = -ENOMEM; 3142 goto fail_put; 3143 } 3144 3145 for (i = 0; i < port->num_sdp_streams; i++) 3146 sinks[i] = i; 3147 3148 txmsg->dst = mstb; 3149 build_allocate_payload(txmsg, port_num, 3150 id, 3151 pbn, port->num_sdp_streams, sinks); 3152 3153 drm_dp_queue_down_tx(mgr, txmsg); 3154 3155 /* 3156 * FIXME: there is a small chance that between getting the last 3157 * connected mstb and sending the payload message, the last connected 3158 * mstb could also be removed from the topology. In the future, this 3159 * needs to be fixed by restarting the 3160 * drm_dp_get_last_connected_port_and_mstb() search in the event of a 3161 * timeout if the topology is still connected to the system. 3162 */ 3163 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3164 if (ret > 0) { 3165 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3166 ret = -EINVAL; 3167 else 3168 ret = 0; 3169 } 3170 kfree(txmsg); 3171fail_put: 3172 drm_dp_mst_topology_put_mstb(mstb); 3173 return ret; 3174} 3175 3176int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr, 3177 struct drm_dp_mst_port *port, bool power_up) 3178{ 3179 struct drm_dp_sideband_msg_tx *txmsg; 3180 int ret; 3181 3182 port = drm_dp_mst_topology_get_port_validated(mgr, port); 3183 if (!port) 3184 return -EINVAL; 3185 3186 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3187 if (!txmsg) { 3188 drm_dp_mst_topology_put_port(port); 3189 return -ENOMEM; 3190 } 3191 3192 txmsg->dst = port->parent; 3193 build_power_updown_phy(txmsg, port->port_num, power_up); 3194 drm_dp_queue_down_tx(mgr, txmsg); 3195 3196 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg); 3197 if (ret > 0) { 3198 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3199 ret = -EINVAL; 3200 else 3201 ret = 0; 3202 } 3203 kfree(txmsg); 3204 drm_dp_mst_topology_put_port(port); 3205 3206 return ret; 3207} 3208EXPORT_SYMBOL(drm_dp_send_power_updown_phy); 3209 3210int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr, 3211 struct drm_dp_mst_port *port, 3212 struct drm_dp_query_stream_enc_status_ack_reply *status) 3213{ 3214 struct drm_dp_mst_topology_state *state; 3215 struct drm_dp_mst_atomic_payload *payload; 3216 struct drm_dp_sideband_msg_tx *txmsg; 3217 u8 nonce[7]; 3218 int ret; 3219 3220 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3221 if (!txmsg) 3222 return -ENOMEM; 3223 3224 port = drm_dp_mst_topology_get_port_validated(mgr, port); 3225 if (!port) { 3226 ret = -EINVAL; 3227 goto out_get_port; 3228 } 3229 3230 get_random_bytes(nonce, sizeof(nonce)); 3231 3232 drm_modeset_lock(&mgr->base.lock, NULL); 3233 state = to_drm_dp_mst_topology_state(mgr->base.state); 3234 payload = drm_atomic_get_mst_payload_state(state, port); 3235 3236 /* 3237 * "Source device targets the QUERY_STREAM_ENCRYPTION_STATUS message 3238 * transaction at the MST Branch device directly connected to the 3239 * Source" 3240 */ 3241 txmsg->dst = mgr->mst_primary; 3242 3243 build_query_stream_enc_status(txmsg, payload->vcpi, nonce); 3244 3245 drm_dp_queue_down_tx(mgr, txmsg); 3246 3247 ret = drm_dp_mst_wait_tx_reply(mgr->mst_primary, txmsg); 3248 if (ret < 0) { 3249 goto out; 3250 } else if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3251 drm_dbg_kms(mgr->dev, "query encryption status nak received\n"); 3252 ret = -ENXIO; 3253 goto out; 3254 } 3255 3256 ret = 0; 3257 memcpy(status, &txmsg->reply.u.enc_status, sizeof(*status)); 3258 3259out: 3260 drm_modeset_unlock(&mgr->base.lock); 3261 drm_dp_mst_topology_put_port(port); 3262out_get_port: 3263 kfree(txmsg); 3264 return ret; 3265} 3266EXPORT_SYMBOL(drm_dp_send_query_stream_enc_status); 3267 3268static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr, 3269 struct drm_dp_mst_atomic_payload *payload) 3270{ 3271 return drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot, 3272 payload->time_slots); 3273} 3274 3275static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr, 3276 struct drm_dp_mst_atomic_payload *payload) 3277{ 3278 int ret; 3279 struct drm_dp_mst_port *port = drm_dp_mst_topology_get_port_validated(mgr, payload->port); 3280 3281 if (!port) 3282 return -EIO; 3283 3284 ret = drm_dp_payload_send_msg(mgr, port, payload->vcpi, payload->pbn); 3285 drm_dp_mst_topology_put_port(port); 3286 return ret; 3287} 3288 3289static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr, 3290 struct drm_dp_mst_topology_state *mst_state, 3291 struct drm_dp_mst_atomic_payload *payload) 3292{ 3293 drm_dbg_kms(mgr->dev, "\n"); 3294 3295 /* it's okay for these to fail */ 3296 drm_dp_payload_send_msg(mgr, payload->port, payload->vcpi, 0); 3297 drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot, 0); 3298 3299 return 0; 3300} 3301 3302/** 3303 * drm_dp_add_payload_part1() - Execute payload update part 1 3304 * @mgr: Manager to use. 3305 * @mst_state: The MST atomic state 3306 * @payload: The payload to write 3307 * 3308 * Determines the starting time slot for the given payload, and programs the VCPI for this payload 3309 * into hardware. After calling this, the driver should generate ACT and payload packets. 3310 * 3311 * Returns: 0 on success, error code on failure. In the event that this fails, 3312 * @payload.vc_start_slot will also be set to -1. 3313 */ 3314int drm_dp_add_payload_part1(struct drm_dp_mst_topology_mgr *mgr, 3315 struct drm_dp_mst_topology_state *mst_state, 3316 struct drm_dp_mst_atomic_payload *payload) 3317{ 3318 struct drm_dp_mst_port *port; 3319 int ret; 3320 3321 port = drm_dp_mst_topology_get_port_validated(mgr, payload->port); 3322 if (!port) 3323 return 0; 3324 3325 if (mgr->payload_count == 0) 3326 mgr->next_start_slot = mst_state->start_slot; 3327 3328 payload->vc_start_slot = mgr->next_start_slot; 3329 3330 ret = drm_dp_create_payload_step1(mgr, payload); 3331 drm_dp_mst_topology_put_port(port); 3332 if (ret < 0) { 3333 drm_warn(mgr->dev, "Failed to create MST payload for port %p: %d\n", 3334 payload->port, ret); 3335 payload->vc_start_slot = -1; 3336 return ret; 3337 } 3338 3339 mgr->payload_count++; 3340 mgr->next_start_slot += payload->time_slots; 3341 3342 return 0; 3343} 3344EXPORT_SYMBOL(drm_dp_add_payload_part1); 3345 3346/** 3347 * drm_dp_remove_payload() - Remove an MST payload 3348 * @mgr: Manager to use. 3349 * @mst_state: The MST atomic state 3350 * @payload: The payload to write 3351 * 3352 * Removes a payload from an MST topology if it was successfully assigned a start slot. Also updates 3353 * the starting time slots of all other payloads which would have been shifted towards the start of 3354 * the VC table as a result. After calling this, the driver should generate ACT and payload packets. 3355 */ 3356void drm_dp_remove_payload(struct drm_dp_mst_topology_mgr *mgr, 3357 struct drm_dp_mst_topology_state *mst_state, 3358 struct drm_dp_mst_atomic_payload *payload) 3359{ 3360 struct drm_dp_mst_atomic_payload *pos; 3361 bool send_remove = false; 3362 3363 /* We failed to make the payload, so nothing to do */ 3364 if (payload->vc_start_slot == -1) 3365 return; 3366 3367 mutex_lock(&mgr->lock); 3368 send_remove = drm_dp_mst_port_downstream_of_branch(payload->port, mgr->mst_primary); 3369 mutex_unlock(&mgr->lock); 3370 3371 if (send_remove) 3372 drm_dp_destroy_payload_step1(mgr, mst_state, payload); 3373 else 3374 drm_dbg_kms(mgr->dev, "Payload for VCPI %d not in topology, not sending remove\n", 3375 payload->vcpi); 3376 3377 list_for_each_entry(pos, &mst_state->payloads, next) { 3378 if (pos != payload && pos->vc_start_slot > payload->vc_start_slot) 3379 pos->vc_start_slot -= payload->time_slots; 3380 } 3381 payload->vc_start_slot = -1; 3382 3383 mgr->payload_count--; 3384 mgr->next_start_slot -= payload->time_slots; 3385 3386 if (payload->delete) 3387 drm_dp_mst_put_port_malloc(payload->port); 3388} 3389EXPORT_SYMBOL(drm_dp_remove_payload); 3390 3391/** 3392 * drm_dp_add_payload_part2() - Execute payload update part 2 3393 * @mgr: Manager to use. 3394 * @state: The global atomic state 3395 * @payload: The payload to update 3396 * 3397 * If @payload was successfully assigned a starting time slot by drm_dp_add_payload_part1(), this 3398 * function will send the sideband messages to finish allocating this payload. 3399 * 3400 * Returns: 0 on success, negative error code on failure. 3401 */ 3402int drm_dp_add_payload_part2(struct drm_dp_mst_topology_mgr *mgr, 3403 struct drm_atomic_state *state, 3404 struct drm_dp_mst_atomic_payload *payload) 3405{ 3406 int ret = 0; 3407 3408 /* Skip failed payloads */ 3409 if (payload->vc_start_slot == -1) { 3410 drm_dbg_kms(state->dev, "Part 1 of payload creation for %s failed, skipping part 2\n", 3411 payload->port->connector->name); 3412 return -EIO; 3413 } 3414 3415 ret = drm_dp_create_payload_step2(mgr, payload); 3416 if (ret < 0) { 3417 if (!payload->delete) 3418 drm_err(mgr->dev, "Step 2 of creating MST payload for %p failed: %d\n", 3419 payload->port, ret); 3420 else 3421 drm_dbg_kms(mgr->dev, "Step 2 of removing MST payload for %p failed: %d\n", 3422 payload->port, ret); 3423 } 3424 3425 return ret; 3426} 3427EXPORT_SYMBOL(drm_dp_add_payload_part2); 3428 3429static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, 3430 struct drm_dp_mst_port *port, 3431 int offset, int size, u8 *bytes) 3432{ 3433 int ret = 0; 3434 struct drm_dp_sideband_msg_tx *txmsg; 3435 struct drm_dp_mst_branch *mstb; 3436 3437 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 3438 if (!mstb) 3439 return -EINVAL; 3440 3441 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3442 if (!txmsg) { 3443 ret = -ENOMEM; 3444 goto fail_put; 3445 } 3446 3447 build_dpcd_read(txmsg, port->port_num, offset, size); 3448 txmsg->dst = port->parent; 3449 3450 drm_dp_queue_down_tx(mgr, txmsg); 3451 3452 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3453 if (ret < 0) 3454 goto fail_free; 3455 3456 if (txmsg->reply.reply_type == 1) { 3457 drm_dbg_kms(mgr->dev, "mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n", 3458 mstb, port->port_num, offset, size); 3459 ret = -EIO; 3460 goto fail_free; 3461 } 3462 3463 if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) { 3464 ret = -EPROTO; 3465 goto fail_free; 3466 } 3467 3468 ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes, 3469 size); 3470 memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret); 3471 3472fail_free: 3473 kfree(txmsg); 3474fail_put: 3475 drm_dp_mst_topology_put_mstb(mstb); 3476 3477 return ret; 3478} 3479 3480static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, 3481 struct drm_dp_mst_port *port, 3482 int offset, int size, u8 *bytes) 3483{ 3484 int ret; 3485 struct drm_dp_sideband_msg_tx *txmsg; 3486 struct drm_dp_mst_branch *mstb; 3487 3488 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 3489 if (!mstb) 3490 return -EINVAL; 3491 3492 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3493 if (!txmsg) { 3494 ret = -ENOMEM; 3495 goto fail_put; 3496 } 3497 3498 build_dpcd_write(txmsg, port->port_num, offset, size, bytes); 3499 txmsg->dst = mstb; 3500 3501 drm_dp_queue_down_tx(mgr, txmsg); 3502 3503 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3504 if (ret > 0) { 3505 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3506 ret = -EIO; 3507 else 3508 ret = size; 3509 } 3510 3511 kfree(txmsg); 3512fail_put: 3513 drm_dp_mst_topology_put_mstb(mstb); 3514 return ret; 3515} 3516 3517static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type) 3518{ 3519 struct drm_dp_sideband_msg_reply_body reply; 3520 3521 reply.reply_type = DP_SIDEBAND_REPLY_ACK; 3522 reply.req_type = req_type; 3523 drm_dp_encode_sideband_reply(&reply, msg); 3524 return 0; 3525} 3526 3527static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr, 3528 struct drm_dp_mst_branch *mstb, 3529 int req_type, bool broadcast) 3530{ 3531 struct drm_dp_sideband_msg_tx *txmsg; 3532 3533 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3534 if (!txmsg) 3535 return -ENOMEM; 3536 3537 txmsg->dst = mstb; 3538 drm_dp_encode_up_ack_reply(txmsg, req_type); 3539 3540 mutex_lock(&mgr->qlock); 3541 /* construct a chunk from the first msg in the tx_msg queue */ 3542 process_single_tx_qlock(mgr, txmsg, true); 3543 mutex_unlock(&mgr->qlock); 3544 3545 kfree(txmsg); 3546 return 0; 3547} 3548 3549/** 3550 * drm_dp_get_vc_payload_bw - get the VC payload BW for an MST link 3551 * @mgr: The &drm_dp_mst_topology_mgr to use 3552 * @link_rate: link rate in 10kbits/s units 3553 * @link_lane_count: lane count 3554 * 3555 * Calculate the total bandwidth of a MultiStream Transport link. The returned 3556 * value is in units of PBNs/(timeslots/1 MTP). This value can be used to 3557 * convert the number of PBNs required for a given stream to the number of 3558 * timeslots this stream requires in each MTP. 3559 */ 3560int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr, 3561 int link_rate, int link_lane_count) 3562{ 3563 if (link_rate == 0 || link_lane_count == 0) 3564 drm_dbg_kms(mgr->dev, "invalid link rate/lane count: (%d / %d)\n", 3565 link_rate, link_lane_count); 3566 3567 /* See DP v2.0 2.6.4.2, VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */ 3568 return link_rate * link_lane_count / 54000; 3569} 3570EXPORT_SYMBOL(drm_dp_get_vc_payload_bw); 3571 3572/** 3573 * drm_dp_read_mst_cap() - check whether or not a sink supports MST 3574 * @aux: The DP AUX channel to use 3575 * @dpcd: A cached copy of the DPCD capabilities for this sink 3576 * 3577 * Returns: %True if the sink supports MST, %false otherwise 3578 */ 3579bool drm_dp_read_mst_cap(struct drm_dp_aux *aux, 3580 const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 3581{ 3582 u8 mstm_cap; 3583 3584 if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_12) 3585 return false; 3586 3587 if (drm_dp_dpcd_readb(aux, DP_MSTM_CAP, &mstm_cap) != 1) 3588 return false; 3589 3590 return mstm_cap & DP_MST_CAP; 3591} 3592EXPORT_SYMBOL(drm_dp_read_mst_cap); 3593 3594/** 3595 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager 3596 * @mgr: manager to set state for 3597 * @mst_state: true to enable MST on this connector - false to disable. 3598 * 3599 * This is called by the driver when it detects an MST capable device plugged 3600 * into a DP MST capable port, or when a DP MST capable device is unplugged. 3601 */ 3602int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state) 3603{ 3604 int ret = 0; 3605 struct drm_dp_mst_branch *mstb = NULL; 3606 3607 mutex_lock(&mgr->lock); 3608 if (mst_state == mgr->mst_state) 3609 goto out_unlock; 3610 3611 mgr->mst_state = mst_state; 3612 /* set the device into MST mode */ 3613 if (mst_state) { 3614 WARN_ON(mgr->mst_primary); 3615 3616 /* get dpcd info */ 3617 ret = drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd); 3618 if (ret < 0) { 3619 drm_dbg_kms(mgr->dev, "%s: failed to read DPCD, ret %d\n", 3620 mgr->aux->name, ret); 3621 goto out_unlock; 3622 } 3623 3624 /* add initial branch device at LCT 1 */ 3625 mstb = drm_dp_add_mst_branch_device(1, NULL); 3626 if (mstb == NULL) { 3627 ret = -ENOMEM; 3628 goto out_unlock; 3629 } 3630 mstb->mgr = mgr; 3631 3632 /* give this the main reference */ 3633 mgr->mst_primary = mstb; 3634 drm_dp_mst_topology_get_mstb(mgr->mst_primary); 3635 3636 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 3637 DP_MST_EN | 3638 DP_UP_REQ_EN | 3639 DP_UPSTREAM_IS_SRC); 3640 if (ret < 0) 3641 goto out_unlock; 3642 3643 /* Write reset payload */ 3644 drm_dp_dpcd_write_payload(mgr, 0, 0, 0x3f); 3645 3646 queue_work(system_long_wq, &mgr->work); 3647 3648 ret = 0; 3649 } else { 3650 /* disable MST on the device */ 3651 mstb = mgr->mst_primary; 3652 mgr->mst_primary = NULL; 3653 /* this can fail if the device is gone */ 3654 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0); 3655 ret = 0; 3656 mgr->payload_id_table_cleared = false; 3657 3658 memset(&mgr->down_rep_recv, 0, sizeof(mgr->down_rep_recv)); 3659 memset(&mgr->up_req_recv, 0, sizeof(mgr->up_req_recv)); 3660 } 3661 3662out_unlock: 3663 mutex_unlock(&mgr->lock); 3664 if (mstb) 3665 drm_dp_mst_topology_put_mstb(mstb); 3666 return ret; 3667 3668} 3669EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst); 3670 3671static void 3672drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb) 3673{ 3674 struct drm_dp_mst_port *port; 3675 3676 /* The link address will need to be re-sent on resume */ 3677 mstb->link_address_sent = false; 3678 3679 list_for_each_entry(port, &mstb->ports, next) 3680 if (port->mstb) 3681 drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb); 3682} 3683 3684/** 3685 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager 3686 * @mgr: manager to suspend 3687 * 3688 * This function tells the MST device that we can't handle UP messages 3689 * anymore. This should stop it from sending any since we are suspended. 3690 */ 3691void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr) 3692{ 3693 mutex_lock(&mgr->lock); 3694 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 3695 DP_MST_EN | DP_UPSTREAM_IS_SRC); 3696 mutex_unlock(&mgr->lock); 3697 flush_work(&mgr->up_req_work); 3698 flush_work(&mgr->work); 3699 flush_work(&mgr->delayed_destroy_work); 3700 3701 mutex_lock(&mgr->lock); 3702 if (mgr->mst_state && mgr->mst_primary) 3703 drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary); 3704 mutex_unlock(&mgr->lock); 3705} 3706EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend); 3707 3708/** 3709 * drm_dp_mst_topology_mgr_resume() - resume the MST manager 3710 * @mgr: manager to resume 3711 * @sync: whether or not to perform topology reprobing synchronously 3712 * 3713 * This will fetch DPCD and see if the device is still there, 3714 * if it is, it will rewrite the MSTM control bits, and return. 3715 * 3716 * If the device fails this returns -1, and the driver should do 3717 * a full MST reprobe, in case we were undocked. 3718 * 3719 * During system resume (where it is assumed that the driver will be calling 3720 * drm_atomic_helper_resume()) this function should be called beforehand with 3721 * @sync set to true. In contexts like runtime resume where the driver is not 3722 * expected to be calling drm_atomic_helper_resume(), this function should be 3723 * called with @sync set to false in order to avoid deadlocking. 3724 * 3725 * Returns: -1 if the MST topology was removed while we were suspended, 0 3726 * otherwise. 3727 */ 3728int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr, 3729 bool sync) 3730{ 3731 int ret; 3732 u8 guid[16]; 3733 3734 mutex_lock(&mgr->lock); 3735 if (!mgr->mst_primary) 3736 goto out_fail; 3737 3738 if (drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd) < 0) { 3739 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n"); 3740 goto out_fail; 3741 } 3742 3743 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 3744 DP_MST_EN | 3745 DP_UP_REQ_EN | 3746 DP_UPSTREAM_IS_SRC); 3747 if (ret < 0) { 3748 drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n"); 3749 goto out_fail; 3750 } 3751 3752 /* Some hubs forget their guids after they resume */ 3753 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16); 3754 if (ret != 16) { 3755 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n"); 3756 goto out_fail; 3757 } 3758 3759 ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid); 3760 if (ret) { 3761 drm_dbg_kms(mgr->dev, "check mstb failed - undocked during suspend?\n"); 3762 goto out_fail; 3763 } 3764 3765 /* 3766 * For the final step of resuming the topology, we need to bring the 3767 * state of our in-memory topology back into sync with reality. So, 3768 * restart the probing process as if we're probing a new hub 3769 */ 3770 queue_work(system_long_wq, &mgr->work); 3771 mutex_unlock(&mgr->lock); 3772 3773 if (sync) { 3774 drm_dbg_kms(mgr->dev, 3775 "Waiting for link probe work to finish re-syncing topology...\n"); 3776 flush_work(&mgr->work); 3777 } 3778 3779 return 0; 3780 3781out_fail: 3782 mutex_unlock(&mgr->lock); 3783 return -1; 3784} 3785EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume); 3786 3787static bool 3788drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up, 3789 struct drm_dp_mst_branch **mstb) 3790{ 3791 int len; 3792 u8 replyblock[32]; 3793 int replylen, curreply; 3794 int ret; 3795 u8 hdrlen; 3796 struct drm_dp_sideband_msg_hdr hdr; 3797 struct drm_dp_sideband_msg_rx *msg = 3798 up ? &mgr->up_req_recv : &mgr->down_rep_recv; 3799 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : 3800 DP_SIDEBAND_MSG_DOWN_REP_BASE; 3801 3802 if (!up) 3803 *mstb = NULL; 3804 3805 len = min(mgr->max_dpcd_transaction_bytes, 16); 3806 ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len); 3807 if (ret != len) { 3808 drm_dbg_kms(mgr->dev, "failed to read DPCD down rep %d %d\n", len, ret); 3809 return false; 3810 } 3811 3812 ret = drm_dp_decode_sideband_msg_hdr(mgr, &hdr, replyblock, len, &hdrlen); 3813 if (ret == false) { 3814 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 3815 1, replyblock, len, false); 3816 drm_dbg_kms(mgr->dev, "ERROR: failed header\n"); 3817 return false; 3818 } 3819 3820 if (!up) { 3821 /* Caller is responsible for giving back this reference */ 3822 *mstb = drm_dp_get_mst_branch_device(mgr, hdr.lct, hdr.rad); 3823 if (!*mstb) { 3824 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr.lct); 3825 return false; 3826 } 3827 } 3828 3829 if (!drm_dp_sideband_msg_set_header(msg, &hdr, hdrlen)) { 3830 drm_dbg_kms(mgr->dev, "sideband msg set header failed %d\n", replyblock[0]); 3831 return false; 3832 } 3833 3834 replylen = min(msg->curchunk_len, (u8)(len - hdrlen)); 3835 ret = drm_dp_sideband_append_payload(msg, replyblock + hdrlen, replylen); 3836 if (!ret) { 3837 drm_dbg_kms(mgr->dev, "sideband msg build failed %d\n", replyblock[0]); 3838 return false; 3839 } 3840 3841 replylen = msg->curchunk_len + msg->curchunk_hdrlen - len; 3842 curreply = len; 3843 while (replylen > 0) { 3844 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16); 3845 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply, 3846 replyblock, len); 3847 if (ret != len) { 3848 drm_dbg_kms(mgr->dev, "failed to read a chunk (len %d, ret %d)\n", 3849 len, ret); 3850 return false; 3851 } 3852 3853 ret = drm_dp_sideband_append_payload(msg, replyblock, len); 3854 if (!ret) { 3855 drm_dbg_kms(mgr->dev, "failed to build sideband msg\n"); 3856 return false; 3857 } 3858 3859 curreply += len; 3860 replylen -= len; 3861 } 3862 return true; 3863} 3864 3865static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr) 3866{ 3867 struct drm_dp_sideband_msg_tx *txmsg; 3868 struct drm_dp_mst_branch *mstb = NULL; 3869 struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv; 3870 3871 if (!drm_dp_get_one_sb_msg(mgr, false, &mstb)) 3872 goto out; 3873 3874 /* Multi-packet message transmission, don't clear the reply */ 3875 if (!msg->have_eomt) 3876 goto out; 3877 3878 /* find the message */ 3879 mutex_lock(&mgr->qlock); 3880 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq, 3881 struct drm_dp_sideband_msg_tx, next); 3882 mutex_unlock(&mgr->qlock); 3883 3884 /* Were we actually expecting a response, and from this mstb? */ 3885 if (!txmsg || txmsg->dst != mstb) { 3886 struct drm_dp_sideband_msg_hdr *hdr; 3887 3888 hdr = &msg->initial_hdr; 3889 drm_dbg_kms(mgr->dev, "Got MST reply with no msg %p %d %d %02x %02x\n", 3890 mstb, hdr->seqno, hdr->lct, hdr->rad[0], msg->msg[0]); 3891 goto out_clear_reply; 3892 } 3893 3894 drm_dp_sideband_parse_reply(mgr, msg, &txmsg->reply); 3895 3896 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3897 drm_dbg_kms(mgr->dev, 3898 "Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n", 3899 txmsg->reply.req_type, 3900 drm_dp_mst_req_type_str(txmsg->reply.req_type), 3901 txmsg->reply.u.nak.reason, 3902 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason), 3903 txmsg->reply.u.nak.nak_data); 3904 } 3905 3906 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx)); 3907 drm_dp_mst_topology_put_mstb(mstb); 3908 3909 mutex_lock(&mgr->qlock); 3910 txmsg->state = DRM_DP_SIDEBAND_TX_RX; 3911 list_del(&txmsg->next); 3912 mutex_unlock(&mgr->qlock); 3913 3914 wake_up_all(&mgr->tx_waitq); 3915 3916 return 0; 3917 3918out_clear_reply: 3919 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx)); 3920out: 3921 if (mstb) 3922 drm_dp_mst_topology_put_mstb(mstb); 3923 3924 return 0; 3925} 3926 3927static inline bool 3928drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr, 3929 struct drm_dp_pending_up_req *up_req) 3930{ 3931 struct drm_dp_mst_branch *mstb = NULL; 3932 struct drm_dp_sideband_msg_req_body *msg = &up_req->msg; 3933 struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr; 3934 bool hotplug = false, dowork = false; 3935 3936 if (hdr->broadcast) { 3937 const u8 *guid = NULL; 3938 3939 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) 3940 guid = msg->u.conn_stat.guid; 3941 else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY) 3942 guid = msg->u.resource_stat.guid; 3943 3944 if (guid) 3945 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid); 3946 } else { 3947 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad); 3948 } 3949 3950 if (!mstb) { 3951 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr->lct); 3952 return false; 3953 } 3954 3955 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */ 3956 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) { 3957 dowork = drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat); 3958 hotplug = true; 3959 } 3960 3961 drm_dp_mst_topology_put_mstb(mstb); 3962 3963 if (dowork) 3964 queue_work(system_long_wq, &mgr->work); 3965 return hotplug; 3966} 3967 3968static void drm_dp_mst_up_req_work(struct work_struct *work) 3969{ 3970 struct drm_dp_mst_topology_mgr *mgr = 3971 container_of(work, struct drm_dp_mst_topology_mgr, 3972 up_req_work); 3973 struct drm_dp_pending_up_req *up_req; 3974 bool send_hotplug = false; 3975 3976 mutex_lock(&mgr->probe_lock); 3977 while (true) { 3978 mutex_lock(&mgr->up_req_lock); 3979 up_req = list_first_entry_or_null(&mgr->up_req_list, 3980 struct drm_dp_pending_up_req, 3981 next); 3982 if (up_req) 3983 list_del(&up_req->next); 3984 mutex_unlock(&mgr->up_req_lock); 3985 3986 if (!up_req) 3987 break; 3988 3989 send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req); 3990 kfree(up_req); 3991 } 3992 mutex_unlock(&mgr->probe_lock); 3993 3994 if (send_hotplug) 3995 drm_kms_helper_hotplug_event(mgr->dev); 3996} 3997 3998static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr) 3999{ 4000 struct drm_dp_pending_up_req *up_req; 4001 4002 if (!drm_dp_get_one_sb_msg(mgr, true, NULL)) 4003 goto out; 4004 4005 if (!mgr->up_req_recv.have_eomt) 4006 return 0; 4007 4008 up_req = kzalloc(sizeof(*up_req), GFP_KERNEL); 4009 if (!up_req) 4010 return -ENOMEM; 4011 4012 INIT_LIST_HEAD(&up_req->next); 4013 4014 drm_dp_sideband_parse_req(mgr, &mgr->up_req_recv, &up_req->msg); 4015 4016 if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY && 4017 up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) { 4018 drm_dbg_kms(mgr->dev, "Received unknown up req type, ignoring: %x\n", 4019 up_req->msg.req_type); 4020 kfree(up_req); 4021 goto out; 4022 } 4023 4024 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type, 4025 false); 4026 4027 if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) { 4028 const struct drm_dp_connection_status_notify *conn_stat = 4029 &up_req->msg.u.conn_stat; 4030 4031 drm_dbg_kms(mgr->dev, "Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", 4032 conn_stat->port_number, 4033 conn_stat->legacy_device_plug_status, 4034 conn_stat->displayport_device_plug_status, 4035 conn_stat->message_capability_status, 4036 conn_stat->input_port, 4037 conn_stat->peer_device_type); 4038 } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) { 4039 const struct drm_dp_resource_status_notify *res_stat = 4040 &up_req->msg.u.resource_stat; 4041 4042 drm_dbg_kms(mgr->dev, "Got RSN: pn: %d avail_pbn %d\n", 4043 res_stat->port_number, 4044 res_stat->available_pbn); 4045 } 4046 4047 up_req->hdr = mgr->up_req_recv.initial_hdr; 4048 mutex_lock(&mgr->up_req_lock); 4049 list_add_tail(&up_req->next, &mgr->up_req_list); 4050 mutex_unlock(&mgr->up_req_lock); 4051 queue_work(system_long_wq, &mgr->up_req_work); 4052 4053out: 4054 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 4055 return 0; 4056} 4057 4058/** 4059 * drm_dp_mst_hpd_irq() - MST hotplug IRQ notify 4060 * @mgr: manager to notify irq for. 4061 * @esi: 4 bytes from SINK_COUNT_ESI 4062 * @handled: whether the hpd interrupt was consumed or not 4063 * 4064 * This should be called from the driver when it detects a short IRQ, 4065 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The 4066 * topology manager will process the sideband messages received as a result 4067 * of this. 4068 */ 4069int drm_dp_mst_hpd_irq(struct drm_dp_mst_topology_mgr *mgr, u8 *esi, bool *handled) 4070{ 4071 int ret = 0; 4072 int sc; 4073 *handled = false; 4074 sc = DP_GET_SINK_COUNT(esi[0]); 4075 4076 if (sc != mgr->sink_count) { 4077 mgr->sink_count = sc; 4078 *handled = true; 4079 } 4080 4081 if (esi[1] & DP_DOWN_REP_MSG_RDY) { 4082 ret = drm_dp_mst_handle_down_rep(mgr); 4083 *handled = true; 4084 } 4085 4086 if (esi[1] & DP_UP_REQ_MSG_RDY) { 4087 ret |= drm_dp_mst_handle_up_req(mgr); 4088 *handled = true; 4089 } 4090 4091 drm_dp_mst_kick_tx(mgr); 4092 return ret; 4093} 4094EXPORT_SYMBOL(drm_dp_mst_hpd_irq); 4095 4096/** 4097 * drm_dp_mst_detect_port() - get connection status for an MST port 4098 * @connector: DRM connector for this port 4099 * @ctx: The acquisition context to use for grabbing locks 4100 * @mgr: manager for this port 4101 * @port: pointer to a port 4102 * 4103 * This returns the current connection state for a port. 4104 */ 4105int 4106drm_dp_mst_detect_port(struct drm_connector *connector, 4107 struct drm_modeset_acquire_ctx *ctx, 4108 struct drm_dp_mst_topology_mgr *mgr, 4109 struct drm_dp_mst_port *port) 4110{ 4111 int ret; 4112 4113 /* we need to search for the port in the mgr in case it's gone */ 4114 port = drm_dp_mst_topology_get_port_validated(mgr, port); 4115 if (!port) 4116 return connector_status_disconnected; 4117 4118 ret = drm_modeset_lock(&mgr->base.lock, ctx); 4119 if (ret) 4120 goto out; 4121 4122 ret = connector_status_disconnected; 4123 4124 if (!port->ddps) 4125 goto out; 4126 4127 switch (port->pdt) { 4128 case DP_PEER_DEVICE_NONE: 4129 break; 4130 case DP_PEER_DEVICE_MST_BRANCHING: 4131 if (!port->mcs) 4132 ret = connector_status_connected; 4133 break; 4134 4135 case DP_PEER_DEVICE_SST_SINK: 4136 ret = connector_status_connected; 4137 /* for logical ports - cache the EDID */ 4138 if (port->port_num >= DP_MST_LOGICAL_PORT_0 && !port->cached_edid) 4139 port->cached_edid = drm_get_edid(connector, &port->aux.ddc); 4140 break; 4141 case DP_PEER_DEVICE_DP_LEGACY_CONV: 4142 if (port->ldps) 4143 ret = connector_status_connected; 4144 break; 4145 } 4146out: 4147 drm_dp_mst_topology_put_port(port); 4148 return ret; 4149} 4150EXPORT_SYMBOL(drm_dp_mst_detect_port); 4151 4152/** 4153 * drm_dp_mst_get_edid() - get EDID for an MST port 4154 * @connector: toplevel connector to get EDID for 4155 * @mgr: manager for this port 4156 * @port: unverified pointer to a port. 4157 * 4158 * This returns an EDID for the port connected to a connector, 4159 * It validates the pointer still exists so the caller doesn't require a 4160 * reference. 4161 */ 4162struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, struct drm_dp_mst_topology_mgr *mgr, struct drm_dp_mst_port *port) 4163{ 4164 struct edid *edid = NULL; 4165 4166 /* we need to search for the port in the mgr in case it's gone */ 4167 port = drm_dp_mst_topology_get_port_validated(mgr, port); 4168 if (!port) 4169 return NULL; 4170 4171 if (port->cached_edid) 4172 edid = drm_edid_duplicate(port->cached_edid); 4173 else { 4174 edid = drm_get_edid(connector, &port->aux.ddc); 4175 } 4176 port->has_audio = drm_detect_monitor_audio(edid); 4177 drm_dp_mst_topology_put_port(port); 4178 return edid; 4179} 4180EXPORT_SYMBOL(drm_dp_mst_get_edid); 4181 4182/** 4183 * drm_dp_atomic_find_time_slots() - Find and add time slots to the state 4184 * @state: global atomic state 4185 * @mgr: MST topology manager for the port 4186 * @port: port to find time slots for 4187 * @pbn: bandwidth required for the mode in PBN 4188 * 4189 * Allocates time slots to @port, replacing any previous time slot allocations it may 4190 * have had. Any atomic drivers which support MST must call this function in 4191 * their &drm_encoder_helper_funcs.atomic_check() callback unconditionally to 4192 * change the current time slot allocation for the new state, and ensure the MST 4193 * atomic state is added whenever the state of payloads in the topology changes. 4194 * 4195 * Allocations set by this function are not checked against the bandwidth 4196 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check(). 4197 * 4198 * Additionally, it is OK to call this function multiple times on the same 4199 * @port as needed. It is not OK however, to call this function and 4200 * drm_dp_atomic_release_time_slots() in the same atomic check phase. 4201 * 4202 * See also: 4203 * drm_dp_atomic_release_time_slots() 4204 * drm_dp_mst_atomic_check() 4205 * 4206 * Returns: 4207 * Total slots in the atomic state assigned for this port, or a negative error 4208 * code if the port no longer exists 4209 */ 4210int drm_dp_atomic_find_time_slots(struct drm_atomic_state *state, 4211 struct drm_dp_mst_topology_mgr *mgr, 4212 struct drm_dp_mst_port *port, int pbn) 4213{ 4214 struct drm_dp_mst_topology_state *topology_state; 4215 struct drm_dp_mst_atomic_payload *payload = NULL; 4216 struct drm_connector_state *conn_state; 4217 int prev_slots = 0, prev_bw = 0, req_slots; 4218 4219 topology_state = drm_atomic_get_mst_topology_state(state, mgr); 4220 if (IS_ERR(topology_state)) 4221 return PTR_ERR(topology_state); 4222 4223 conn_state = drm_atomic_get_new_connector_state(state, port->connector); 4224 topology_state->pending_crtc_mask |= drm_crtc_mask(conn_state->crtc); 4225 4226 /* Find the current allocation for this port, if any */ 4227 payload = drm_atomic_get_mst_payload_state(topology_state, port); 4228 if (payload) { 4229 prev_slots = payload->time_slots; 4230 prev_bw = payload->pbn; 4231 4232 /* 4233 * This should never happen, unless the driver tries 4234 * releasing and allocating the same timeslot allocation, 4235 * which is an error 4236 */ 4237 if (drm_WARN_ON(mgr->dev, payload->delete)) { 4238 drm_err(mgr->dev, 4239 "cannot allocate and release time slots on [MST PORT:%p] in the same state\n", 4240 port); 4241 return -EINVAL; 4242 } 4243 } 4244 4245 req_slots = DIV_ROUND_UP(pbn, topology_state->pbn_div); 4246 4247 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] TU %d -> %d\n", 4248 port->connector->base.id, port->connector->name, 4249 port, prev_slots, req_slots); 4250 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n", 4251 port->connector->base.id, port->connector->name, 4252 port, prev_bw, pbn); 4253 4254 /* Add the new allocation to the state, note the VCPI isn't assigned until the end */ 4255 if (!payload) { 4256 payload = kzalloc(sizeof(*payload), GFP_KERNEL); 4257 if (!payload) 4258 return -ENOMEM; 4259 4260 drm_dp_mst_get_port_malloc(port); 4261 payload->port = port; 4262 payload->vc_start_slot = -1; 4263 list_add(&payload->next, &topology_state->payloads); 4264 } 4265 payload->time_slots = req_slots; 4266 payload->pbn = pbn; 4267 4268 return req_slots; 4269} 4270EXPORT_SYMBOL(drm_dp_atomic_find_time_slots); 4271 4272/** 4273 * drm_dp_atomic_release_time_slots() - Release allocated time slots 4274 * @state: global atomic state 4275 * @mgr: MST topology manager for the port 4276 * @port: The port to release the time slots from 4277 * 4278 * Releases any time slots that have been allocated to a port in the atomic 4279 * state. Any atomic drivers which support MST must call this function 4280 * unconditionally in their &drm_connector_helper_funcs.atomic_check() callback. 4281 * This helper will check whether time slots would be released by the new state and 4282 * respond accordingly, along with ensuring the MST state is always added to the 4283 * atomic state whenever a new state would modify the state of payloads on the 4284 * topology. 4285 * 4286 * It is OK to call this even if @port has been removed from the system. 4287 * Additionally, it is OK to call this function multiple times on the same 4288 * @port as needed. It is not OK however, to call this function and 4289 * drm_dp_atomic_find_time_slots() on the same @port in a single atomic check 4290 * phase. 4291 * 4292 * See also: 4293 * drm_dp_atomic_find_time_slots() 4294 * drm_dp_mst_atomic_check() 4295 * 4296 * Returns: 4297 * 0 on success, negative error code otherwise 4298 */ 4299int drm_dp_atomic_release_time_slots(struct drm_atomic_state *state, 4300 struct drm_dp_mst_topology_mgr *mgr, 4301 struct drm_dp_mst_port *port) 4302{ 4303 struct drm_dp_mst_topology_state *topology_state; 4304 struct drm_dp_mst_atomic_payload *payload; 4305 struct drm_connector_state *old_conn_state, *new_conn_state; 4306 bool update_payload = true; 4307 4308 old_conn_state = drm_atomic_get_old_connector_state(state, port->connector); 4309 if (!old_conn_state->crtc) 4310 return 0; 4311 4312 /* If the CRTC isn't disabled by this state, don't release it's payload */ 4313 new_conn_state = drm_atomic_get_new_connector_state(state, port->connector); 4314 if (new_conn_state->crtc) { 4315 struct drm_crtc_state *crtc_state = 4316 drm_atomic_get_new_crtc_state(state, new_conn_state->crtc); 4317 4318 /* No modeset means no payload changes, so it's safe to not pull in the MST state */ 4319 if (!crtc_state || !drm_atomic_crtc_needs_modeset(crtc_state)) 4320 return 0; 4321 4322 if (!crtc_state->mode_changed && !crtc_state->connectors_changed) 4323 update_payload = false; 4324 } 4325 4326 topology_state = drm_atomic_get_mst_topology_state(state, mgr); 4327 if (IS_ERR(topology_state)) 4328 return PTR_ERR(topology_state); 4329 4330 topology_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc); 4331 if (!update_payload) 4332 return 0; 4333 4334 payload = drm_atomic_get_mst_payload_state(topology_state, port); 4335 if (WARN_ON(!payload)) { 4336 drm_err(mgr->dev, "No payload for [MST PORT:%p] found in mst state %p\n", 4337 port, &topology_state->base); 4338 return -EINVAL; 4339 } 4340 4341 if (new_conn_state->crtc) 4342 return 0; 4343 4344 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] TU %d -> 0\n", port, payload->time_slots); 4345 if (!payload->delete) { 4346 payload->pbn = 0; 4347 payload->delete = true; 4348 topology_state->payload_mask &= ~BIT(payload->vcpi - 1); 4349 } 4350 4351 return 0; 4352} 4353EXPORT_SYMBOL(drm_dp_atomic_release_time_slots); 4354 4355/** 4356 * drm_dp_mst_atomic_setup_commit() - setup_commit hook for MST helpers 4357 * @state: global atomic state 4358 * 4359 * This function saves all of the &drm_crtc_commit structs in an atomic state that touch any CRTCs 4360 * currently assigned to an MST topology. Drivers must call this hook from their 4361 * &drm_mode_config_helper_funcs.atomic_commit_setup hook. 4362 * 4363 * Returns: 4364 * 0 if all CRTC commits were retrieved successfully, negative error code otherwise 4365 */ 4366int drm_dp_mst_atomic_setup_commit(struct drm_atomic_state *state) 4367{ 4368 struct drm_dp_mst_topology_mgr *mgr; 4369 struct drm_dp_mst_topology_state *mst_state; 4370 struct drm_crtc *crtc; 4371 struct drm_crtc_state *crtc_state; 4372 int i, j, commit_idx, num_commit_deps; 4373 4374 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { 4375 if (!mst_state->pending_crtc_mask) 4376 continue; 4377 4378 num_commit_deps = hweight32(mst_state->pending_crtc_mask); 4379 mst_state->commit_deps = kmalloc_array(num_commit_deps, 4380 sizeof(*mst_state->commit_deps), GFP_KERNEL); 4381 if (!mst_state->commit_deps) 4382 return -ENOMEM; 4383 mst_state->num_commit_deps = num_commit_deps; 4384 4385 commit_idx = 0; 4386 for_each_new_crtc_in_state(state, crtc, crtc_state, j) { 4387 if (mst_state->pending_crtc_mask & drm_crtc_mask(crtc)) { 4388 mst_state->commit_deps[commit_idx++] = 4389 drm_crtc_commit_get(crtc_state->commit); 4390 } 4391 } 4392 } 4393 4394 return 0; 4395} 4396EXPORT_SYMBOL(drm_dp_mst_atomic_setup_commit); 4397 4398/** 4399 * drm_dp_mst_atomic_wait_for_dependencies() - Wait for all pending commits on MST topologies, 4400 * prepare new MST state for commit 4401 * @state: global atomic state 4402 * 4403 * Goes through any MST topologies in this atomic state, and waits for any pending commits which 4404 * touched CRTCs that were/are on an MST topology to be programmed to hardware and flipped to before 4405 * returning. This is to prevent multiple non-blocking commits affecting an MST topology from racing 4406 * with eachother by forcing them to be executed sequentially in situations where the only resources 4407 * the modeset objects in these commits share are an MST topology. 4408 * 4409 * This function also prepares the new MST state for commit by performing some state preparation 4410 * which can't be done until this point, such as reading back the final VC start slots (which are 4411 * determined at commit-time) from the previous state. 4412 * 4413 * All MST drivers must call this function after calling drm_atomic_helper_wait_for_dependencies(), 4414 * or whatever their equivalent of that is. 4415 */ 4416void drm_dp_mst_atomic_wait_for_dependencies(struct drm_atomic_state *state) 4417{ 4418 struct drm_dp_mst_topology_state *old_mst_state, *new_mst_state; 4419 struct drm_dp_mst_topology_mgr *mgr; 4420 struct drm_dp_mst_atomic_payload *old_payload, *new_payload; 4421 int i, j, ret; 4422 4423 for_each_oldnew_mst_mgr_in_state(state, mgr, old_mst_state, new_mst_state, i) { 4424 for (j = 0; j < old_mst_state->num_commit_deps; j++) { 4425 ret = drm_crtc_commit_wait(old_mst_state->commit_deps[j]); 4426 if (ret < 0) 4427 drm_err(state->dev, "Failed to wait for %s: %d\n", 4428 old_mst_state->commit_deps[j]->crtc->name, ret); 4429 } 4430 4431 /* Now that previous state is committed, it's safe to copy over the start slot 4432 * assignments 4433 */ 4434 list_for_each_entry(old_payload, &old_mst_state->payloads, next) { 4435 if (old_payload->delete) 4436 continue; 4437 4438 new_payload = drm_atomic_get_mst_payload_state(new_mst_state, 4439 old_payload->port); 4440 new_payload->vc_start_slot = old_payload->vc_start_slot; 4441 } 4442 } 4443} 4444EXPORT_SYMBOL(drm_dp_mst_atomic_wait_for_dependencies); 4445 4446/** 4447 * drm_dp_mst_root_conn_atomic_check() - Serialize CRTC commits on MST-capable connectors operating 4448 * in SST mode 4449 * @new_conn_state: The new connector state of the &drm_connector 4450 * @mgr: The MST topology manager for the &drm_connector 4451 * 4452 * Since MST uses fake &drm_encoder structs, the generic atomic modesetting code isn't able to 4453 * serialize non-blocking commits happening on the real DP connector of an MST topology switching 4454 * into/away from MST mode - as the CRTC on the real DP connector and the CRTCs on the connector's 4455 * MST topology will never share the same &drm_encoder. 4456 * 4457 * This function takes care of this serialization issue, by checking a root MST connector's atomic 4458 * state to determine if it is about to have a modeset - and then pulling in the MST topology state 4459 * if so, along with adding any relevant CRTCs to &drm_dp_mst_topology_state.pending_crtc_mask. 4460 * 4461 * Drivers implementing MST must call this function from the 4462 * &drm_connector_helper_funcs.atomic_check hook of any physical DP &drm_connector capable of 4463 * driving MST sinks. 4464 * 4465 * Returns: 4466 * 0 on success, negative error code otherwise 4467 */ 4468int drm_dp_mst_root_conn_atomic_check(struct drm_connector_state *new_conn_state, 4469 struct drm_dp_mst_topology_mgr *mgr) 4470{ 4471 struct drm_atomic_state *state = new_conn_state->state; 4472 struct drm_connector_state *old_conn_state = 4473 drm_atomic_get_old_connector_state(state, new_conn_state->connector); 4474 struct drm_crtc_state *crtc_state; 4475 struct drm_dp_mst_topology_state *mst_state = NULL; 4476 4477 if (new_conn_state->crtc) { 4478 crtc_state = drm_atomic_get_new_crtc_state(state, new_conn_state->crtc); 4479 if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) { 4480 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 4481 if (IS_ERR(mst_state)) 4482 return PTR_ERR(mst_state); 4483 4484 mst_state->pending_crtc_mask |= drm_crtc_mask(new_conn_state->crtc); 4485 } 4486 } 4487 4488 if (old_conn_state->crtc) { 4489 crtc_state = drm_atomic_get_new_crtc_state(state, old_conn_state->crtc); 4490 if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) { 4491 if (!mst_state) { 4492 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 4493 if (IS_ERR(mst_state)) 4494 return PTR_ERR(mst_state); 4495 } 4496 4497 mst_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc); 4498 } 4499 } 4500 4501 return 0; 4502} 4503EXPORT_SYMBOL(drm_dp_mst_root_conn_atomic_check); 4504 4505/** 4506 * drm_dp_mst_update_slots() - updates the slot info depending on the DP ecoding format 4507 * @mst_state: mst_state to update 4508 * @link_encoding_cap: the ecoding format on the link 4509 */ 4510void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap) 4511{ 4512 if (link_encoding_cap == DP_CAP_ANSI_128B132B) { 4513 mst_state->total_avail_slots = 64; 4514 mst_state->start_slot = 0; 4515 } else { 4516 mst_state->total_avail_slots = 63; 4517 mst_state->start_slot = 1; 4518 } 4519 4520 DRM_DEBUG_KMS("%s encoding format on mst_state 0x%p\n", 4521 (link_encoding_cap == DP_CAP_ANSI_128B132B) ? "128b/132b":"8b/10b", 4522 mst_state); 4523} 4524EXPORT_SYMBOL(drm_dp_mst_update_slots); 4525 4526static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, 4527 int id, u8 start_slot, u8 num_slots) 4528{ 4529 u8 payload_alloc[3], status; 4530 int ret; 4531 int retries = 0; 4532 4533 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, 4534 DP_PAYLOAD_TABLE_UPDATED); 4535 4536 payload_alloc[0] = id; 4537 payload_alloc[1] = start_slot; 4538 payload_alloc[2] = num_slots; 4539 4540 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3); 4541 if (ret != 3) { 4542 drm_dbg_kms(mgr->dev, "failed to write payload allocation %d\n", ret); 4543 goto fail; 4544 } 4545 4546retry: 4547 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 4548 if (ret < 0) { 4549 drm_dbg_kms(mgr->dev, "failed to read payload table status %d\n", ret); 4550 goto fail; 4551 } 4552 4553 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) { 4554 retries++; 4555 if (retries < 20) { 4556 usleep_range(10000, 20000); 4557 goto retry; 4558 } 4559 drm_dbg_kms(mgr->dev, "status not set after read payload table status %d\n", 4560 status); 4561 ret = -EINVAL; 4562 goto fail; 4563 } 4564 ret = 0; 4565fail: 4566 return ret; 4567} 4568 4569static int do_get_act_status(struct drm_dp_aux *aux) 4570{ 4571 int ret; 4572 u8 status; 4573 4574 ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 4575 if (ret < 0) 4576 return ret; 4577 4578 return status; 4579} 4580 4581/** 4582 * drm_dp_check_act_status() - Polls for ACT handled status. 4583 * @mgr: manager to use 4584 * 4585 * Tries waiting for the MST hub to finish updating it's payload table by 4586 * polling for the ACT handled bit for up to 3 seconds (yes-some hubs really 4587 * take that long). 4588 * 4589 * Returns: 4590 * 0 if the ACT was handled in time, negative error code on failure. 4591 */ 4592int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr) 4593{ 4594 /* 4595 * There doesn't seem to be any recommended retry count or timeout in 4596 * the MST specification. Since some hubs have been observed to take 4597 * over 1 second to update their payload allocations under certain 4598 * conditions, we use a rather large timeout value. 4599 */ 4600 const int timeout_ms = 3000; 4601 int ret, status; 4602 4603 ret = readx_poll_timeout(do_get_act_status, mgr->aux, status, 4604 status & DP_PAYLOAD_ACT_HANDLED || status < 0, 4605 200, timeout_ms * USEC_PER_MSEC); 4606 if (ret < 0 && status >= 0) { 4607 drm_err(mgr->dev, "Failed to get ACT after %dms, last status: %02x\n", 4608 timeout_ms, status); 4609 return -EINVAL; 4610 } else if (status < 0) { 4611 /* 4612 * Failure here isn't unexpected - the hub may have 4613 * just been unplugged 4614 */ 4615 drm_dbg_kms(mgr->dev, "Failed to read payload table status: %d\n", status); 4616 return status; 4617 } 4618 4619 return 0; 4620} 4621EXPORT_SYMBOL(drm_dp_check_act_status); 4622 4623/** 4624 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode. 4625 * @clock: dot clock for the mode 4626 * @bpp: bpp for the mode. 4627 * @dsc: DSC mode. If true, bpp has units of 1/16 of a bit per pixel 4628 * 4629 * This uses the formula in the spec to calculate the PBN value for a mode. 4630 */ 4631int drm_dp_calc_pbn_mode(int clock, int bpp, bool dsc) 4632{ 4633 /* 4634 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006 4635 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on 4636 * common multiplier to render an integer PBN for all link rate/lane 4637 * counts combinations 4638 * calculate 4639 * peak_kbps *= (1006/1000) 4640 * peak_kbps *= (64/54) 4641 * peak_kbps *= 8 convert to bytes 4642 * 4643 * If the bpp is in units of 1/16, further divide by 16. Put this 4644 * factor in the numerator rather than the denominator to avoid 4645 * integer overflow 4646 */ 4647 4648 if (dsc) 4649 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * (bpp / 16), 64 * 1006), 4650 8 * 54 * 1000 * 1000); 4651 4652 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006), 4653 8 * 54 * 1000 * 1000); 4654} 4655EXPORT_SYMBOL(drm_dp_calc_pbn_mode); 4656 4657/* we want to kick the TX after we've ack the up/down IRQs. */ 4658static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr) 4659{ 4660 queue_work(system_long_wq, &mgr->tx_work); 4661} 4662 4663/* 4664 * Helper function for parsing DP device types into convenient strings 4665 * for use with dp_mst_topology 4666 */ 4667static const char *pdt_to_string(u8 pdt) 4668{ 4669 switch (pdt) { 4670 case DP_PEER_DEVICE_NONE: 4671 return "NONE"; 4672 case DP_PEER_DEVICE_SOURCE_OR_SST: 4673 return "SOURCE OR SST"; 4674 case DP_PEER_DEVICE_MST_BRANCHING: 4675 return "MST BRANCHING"; 4676 case DP_PEER_DEVICE_SST_SINK: 4677 return "SST SINK"; 4678 case DP_PEER_DEVICE_DP_LEGACY_CONV: 4679 return "DP LEGACY CONV"; 4680 default: 4681 return "ERR"; 4682 } 4683} 4684 4685static void drm_dp_mst_dump_mstb(struct seq_file *m, 4686 struct drm_dp_mst_branch *mstb) 4687{ 4688 struct drm_dp_mst_port *port; 4689 int tabs = mstb->lct; 4690 char prefix[10]; 4691 int i; 4692 4693 for (i = 0; i < tabs; i++) 4694 prefix[i] = '\t'; 4695 prefix[i] = '\0'; 4696 4697 seq_printf(m, "%smstb - [%p]: num_ports: %d\n", prefix, mstb, mstb->num_ports); 4698 list_for_each_entry(port, &mstb->ports, next) { 4699 seq_printf(m, "%sport %d - [%p] (%s - %s): ddps: %d, ldps: %d, sdp: %d/%d, fec: %s, conn: %p\n", 4700 prefix, 4701 port->port_num, 4702 port, 4703 port->input ? "input" : "output", 4704 pdt_to_string(port->pdt), 4705 port->ddps, 4706 port->ldps, 4707 port->num_sdp_streams, 4708 port->num_sdp_stream_sinks, 4709 port->fec_capable ? "true" : "false", 4710 port->connector); 4711 if (port->mstb) 4712 drm_dp_mst_dump_mstb(m, port->mstb); 4713 } 4714} 4715 4716#define DP_PAYLOAD_TABLE_SIZE 64 4717 4718static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, 4719 char *buf) 4720{ 4721 int i; 4722 4723 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) { 4724 if (drm_dp_dpcd_read(mgr->aux, 4725 DP_PAYLOAD_TABLE_UPDATE_STATUS + i, 4726 &buf[i], 16) != 16) 4727 return false; 4728 } 4729 return true; 4730} 4731 4732static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr, 4733 struct drm_dp_mst_port *port, char *name, 4734 int namelen) 4735{ 4736 struct edid *mst_edid; 4737 4738 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port); 4739 drm_edid_get_monitor_name(mst_edid, name, namelen); 4740 kfree(mst_edid); 4741} 4742 4743/** 4744 * drm_dp_mst_dump_topology(): dump topology to seq file. 4745 * @m: seq_file to dump output to 4746 * @mgr: manager to dump current topology for. 4747 * 4748 * helper to dump MST topology to a seq file for debugfs. 4749 */ 4750void drm_dp_mst_dump_topology(struct seq_file *m, 4751 struct drm_dp_mst_topology_mgr *mgr) 4752{ 4753 struct drm_dp_mst_topology_state *state; 4754 struct drm_dp_mst_atomic_payload *payload; 4755 int i, ret; 4756 4757 mutex_lock(&mgr->lock); 4758 if (mgr->mst_primary) 4759 drm_dp_mst_dump_mstb(m, mgr->mst_primary); 4760 4761 /* dump VCPIs */ 4762 mutex_unlock(&mgr->lock); 4763 4764 ret = drm_modeset_lock_single_interruptible(&mgr->base.lock); 4765 if (ret < 0) 4766 return; 4767 4768 state = to_drm_dp_mst_topology_state(mgr->base.state); 4769 seq_printf(m, "\n*** Atomic state info ***\n"); 4770 seq_printf(m, "payload_mask: %x, max_payloads: %d, start_slot: %u, pbn_div: %d\n", 4771 state->payload_mask, mgr->max_payloads, state->start_slot, state->pbn_div); 4772 4773 seq_printf(m, "\n| idx | port | vcpi | slots | pbn | dsc | sink name |\n"); 4774 for (i = 0; i < mgr->max_payloads; i++) { 4775 list_for_each_entry(payload, &state->payloads, next) { 4776 char name[14]; 4777 4778 if (payload->vcpi != i || payload->delete) 4779 continue; 4780 4781 fetch_monitor_name(mgr, payload->port, name, sizeof(name)); 4782 seq_printf(m, " %5d %6d %6d %02d - %02d %5d %5s %19s\n", 4783 i, 4784 payload->port->port_num, 4785 payload->vcpi, 4786 payload->vc_start_slot, 4787 payload->vc_start_slot + payload->time_slots - 1, 4788 payload->pbn, 4789 payload->dsc_enabled ? "Y" : "N", 4790 (*name != 0) ? name : "Unknown"); 4791 } 4792 } 4793 4794 seq_printf(m, "\n*** DPCD Info ***\n"); 4795 mutex_lock(&mgr->lock); 4796 if (mgr->mst_primary) { 4797 u8 buf[DP_PAYLOAD_TABLE_SIZE]; 4798 int ret; 4799 4800 if (drm_dp_read_dpcd_caps(mgr->aux, buf) < 0) { 4801 seq_printf(m, "dpcd read failed\n"); 4802 goto out; 4803 } 4804 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf); 4805 4806 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2); 4807 if (ret != 2) { 4808 seq_printf(m, "faux/mst read failed\n"); 4809 goto out; 4810 } 4811 seq_printf(m, "faux/mst: %*ph\n", 2, buf); 4812 4813 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1); 4814 if (ret != 1) { 4815 seq_printf(m, "mst ctrl read failed\n"); 4816 goto out; 4817 } 4818 seq_printf(m, "mst ctrl: %*ph\n", 1, buf); 4819 4820 /* dump the standard OUI branch header */ 4821 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE); 4822 if (ret != DP_BRANCH_OUI_HEADER_SIZE) { 4823 seq_printf(m, "branch oui read failed\n"); 4824 goto out; 4825 } 4826 seq_printf(m, "branch oui: %*phN devid: ", 3, buf); 4827 4828 for (i = 0x3; i < 0x8 && buf[i]; i++) 4829 seq_printf(m, "%c", buf[i]); 4830 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n", 4831 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]); 4832 if (dump_dp_payload_table(mgr, buf)) 4833 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf); 4834 } 4835 4836out: 4837 mutex_unlock(&mgr->lock); 4838 drm_modeset_unlock(&mgr->base.lock); 4839} 4840EXPORT_SYMBOL(drm_dp_mst_dump_topology); 4841 4842static void drm_dp_tx_work(struct work_struct *work) 4843{ 4844 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work); 4845 4846 mutex_lock(&mgr->qlock); 4847 if (!list_empty(&mgr->tx_msg_downq)) 4848 process_single_down_tx_qlock(mgr); 4849 mutex_unlock(&mgr->qlock); 4850} 4851 4852static inline void 4853drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port) 4854{ 4855 drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs); 4856 4857 if (port->connector) { 4858 drm_connector_unregister(port->connector); 4859 drm_connector_put(port->connector); 4860 } 4861 4862 drm_dp_mst_put_port_malloc(port); 4863} 4864 4865static inline void 4866drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb) 4867{ 4868 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 4869 struct drm_dp_mst_port *port, *port_tmp; 4870 struct drm_dp_sideband_msg_tx *txmsg, *txmsg_tmp; 4871 bool wake_tx = false; 4872 4873 mutex_lock(&mgr->lock); 4874 list_for_each_entry_safe(port, port_tmp, &mstb->ports, next) { 4875 list_del(&port->next); 4876 drm_dp_mst_topology_put_port(port); 4877 } 4878 mutex_unlock(&mgr->lock); 4879 4880 /* drop any tx slot msg */ 4881 mutex_lock(&mstb->mgr->qlock); 4882 list_for_each_entry_safe(txmsg, txmsg_tmp, &mgr->tx_msg_downq, next) { 4883 if (txmsg->dst != mstb) 4884 continue; 4885 4886 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 4887 list_del(&txmsg->next); 4888 wake_tx = true; 4889 } 4890 mutex_unlock(&mstb->mgr->qlock); 4891 4892 if (wake_tx) 4893 wake_up_all(&mstb->mgr->tx_waitq); 4894 4895 drm_dp_mst_put_mstb_malloc(mstb); 4896} 4897 4898static void drm_dp_delayed_destroy_work(struct work_struct *work) 4899{ 4900 struct drm_dp_mst_topology_mgr *mgr = 4901 container_of(work, struct drm_dp_mst_topology_mgr, 4902 delayed_destroy_work); 4903 bool send_hotplug = false, go_again; 4904 4905 /* 4906 * Not a regular list traverse as we have to drop the destroy 4907 * connector lock before destroying the mstb/port, to avoid AB->BA 4908 * ordering between this lock and the config mutex. 4909 */ 4910 do { 4911 go_again = false; 4912 4913 for (;;) { 4914 struct drm_dp_mst_branch *mstb; 4915 4916 mutex_lock(&mgr->delayed_destroy_lock); 4917 mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list, 4918 struct drm_dp_mst_branch, 4919 destroy_next); 4920 if (mstb) 4921 list_del(&mstb->destroy_next); 4922 mutex_unlock(&mgr->delayed_destroy_lock); 4923 4924 if (!mstb) 4925 break; 4926 4927 drm_dp_delayed_destroy_mstb(mstb); 4928 go_again = true; 4929 } 4930 4931 for (;;) { 4932 struct drm_dp_mst_port *port; 4933 4934 mutex_lock(&mgr->delayed_destroy_lock); 4935 port = list_first_entry_or_null(&mgr->destroy_port_list, 4936 struct drm_dp_mst_port, 4937 next); 4938 if (port) 4939 list_del(&port->next); 4940 mutex_unlock(&mgr->delayed_destroy_lock); 4941 4942 if (!port) 4943 break; 4944 4945 drm_dp_delayed_destroy_port(port); 4946 send_hotplug = true; 4947 go_again = true; 4948 } 4949 } while (go_again); 4950 4951 if (send_hotplug) 4952 drm_kms_helper_hotplug_event(mgr->dev); 4953} 4954 4955static struct drm_private_state * 4956drm_dp_mst_duplicate_state(struct drm_private_obj *obj) 4957{ 4958 struct drm_dp_mst_topology_state *state, *old_state = 4959 to_dp_mst_topology_state(obj->state); 4960 struct drm_dp_mst_atomic_payload *pos, *payload; 4961 4962 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL); 4963 if (!state) 4964 return NULL; 4965 4966 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base); 4967 4968 INIT_LIST_HEAD(&state->payloads); 4969 state->commit_deps = NULL; 4970 state->num_commit_deps = 0; 4971 state->pending_crtc_mask = 0; 4972 4973 list_for_each_entry(pos, &old_state->payloads, next) { 4974 /* Prune leftover freed timeslot allocations */ 4975 if (pos->delete) 4976 continue; 4977 4978 payload = kmemdup(pos, sizeof(*payload), GFP_KERNEL); 4979 if (!payload) 4980 goto fail; 4981 4982 drm_dp_mst_get_port_malloc(payload->port); 4983 list_add(&payload->next, &state->payloads); 4984 } 4985 4986 return &state->base; 4987 4988fail: 4989 list_for_each_entry_safe(pos, payload, &state->payloads, next) { 4990 drm_dp_mst_put_port_malloc(pos->port); 4991 kfree(pos); 4992 } 4993 kfree(state); 4994 4995 return NULL; 4996} 4997 4998static void drm_dp_mst_destroy_state(struct drm_private_obj *obj, 4999 struct drm_private_state *state) 5000{ 5001 struct drm_dp_mst_topology_state *mst_state = 5002 to_dp_mst_topology_state(state); 5003 struct drm_dp_mst_atomic_payload *pos, *tmp; 5004 int i; 5005 5006 list_for_each_entry_safe(pos, tmp, &mst_state->payloads, next) { 5007 /* We only keep references to ports with active payloads */ 5008 if (!pos->delete) 5009 drm_dp_mst_put_port_malloc(pos->port); 5010 kfree(pos); 5011 } 5012 5013 for (i = 0; i < mst_state->num_commit_deps; i++) 5014 drm_crtc_commit_put(mst_state->commit_deps[i]); 5015 5016 kfree(mst_state->commit_deps); 5017 kfree(mst_state); 5018} 5019 5020static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port, 5021 struct drm_dp_mst_branch *branch) 5022{ 5023 while (port->parent) { 5024 if (port->parent == branch) 5025 return true; 5026 5027 if (port->parent->port_parent) 5028 port = port->parent->port_parent; 5029 else 5030 break; 5031 } 5032 return false; 5033} 5034 5035static int 5036drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, 5037 struct drm_dp_mst_topology_state *state); 5038 5039static int 5040drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb, 5041 struct drm_dp_mst_topology_state *state) 5042{ 5043 struct drm_dp_mst_atomic_payload *payload; 5044 struct drm_dp_mst_port *port; 5045 int pbn_used = 0, ret; 5046 bool found = false; 5047 5048 /* Check that we have at least one port in our state that's downstream 5049 * of this branch, otherwise we can skip this branch 5050 */ 5051 list_for_each_entry(payload, &state->payloads, next) { 5052 if (!payload->pbn || 5053 !drm_dp_mst_port_downstream_of_branch(payload->port, mstb)) 5054 continue; 5055 5056 found = true; 5057 break; 5058 } 5059 if (!found) 5060 return 0; 5061 5062 if (mstb->port_parent) 5063 drm_dbg_atomic(mstb->mgr->dev, 5064 "[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n", 5065 mstb->port_parent->parent, mstb->port_parent, mstb); 5066 else 5067 drm_dbg_atomic(mstb->mgr->dev, "[MSTB:%p] Checking bandwidth limits\n", mstb); 5068 5069 list_for_each_entry(port, &mstb->ports, next) { 5070 ret = drm_dp_mst_atomic_check_port_bw_limit(port, state); 5071 if (ret < 0) 5072 return ret; 5073 5074 pbn_used += ret; 5075 } 5076 5077 return pbn_used; 5078} 5079 5080static int 5081drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, 5082 struct drm_dp_mst_topology_state *state) 5083{ 5084 struct drm_dp_mst_atomic_payload *payload; 5085 int pbn_used = 0; 5086 5087 if (port->pdt == DP_PEER_DEVICE_NONE) 5088 return 0; 5089 5090 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { 5091 payload = drm_atomic_get_mst_payload_state(state, port); 5092 if (!payload) 5093 return 0; 5094 5095 /* 5096 * This could happen if the sink deasserted its HPD line, but 5097 * the branch device still reports it as attached (PDT != NONE). 5098 */ 5099 if (!port->full_pbn) { 5100 drm_dbg_atomic(port->mgr->dev, 5101 "[MSTB:%p] [MST PORT:%p] no BW available for the port\n", 5102 port->parent, port); 5103 return -EINVAL; 5104 } 5105 5106 pbn_used = payload->pbn; 5107 } else { 5108 pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb, 5109 state); 5110 if (pbn_used <= 0) 5111 return pbn_used; 5112 } 5113 5114 if (pbn_used > port->full_pbn) { 5115 drm_dbg_atomic(port->mgr->dev, 5116 "[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n", 5117 port->parent, port, pbn_used, port->full_pbn); 5118 return -ENOSPC; 5119 } 5120 5121 drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n", 5122 port->parent, port, pbn_used, port->full_pbn); 5123 5124 return pbn_used; 5125} 5126 5127static inline int 5128drm_dp_mst_atomic_check_payload_alloc_limits(struct drm_dp_mst_topology_mgr *mgr, 5129 struct drm_dp_mst_topology_state *mst_state) 5130{ 5131 struct drm_dp_mst_atomic_payload *payload; 5132 int avail_slots = mst_state->total_avail_slots, payload_count = 0; 5133 5134 list_for_each_entry(payload, &mst_state->payloads, next) { 5135 /* Releasing payloads is always OK-even if the port is gone */ 5136 if (payload->delete) { 5137 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] releases all time slots\n", 5138 payload->port); 5139 continue; 5140 } 5141 5142 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] requires %d time slots\n", 5143 payload->port, payload->time_slots); 5144 5145 avail_slots -= payload->time_slots; 5146 if (avail_slots < 0) { 5147 drm_dbg_atomic(mgr->dev, 5148 "[MST PORT:%p] not enough time slots in mst state %p (avail=%d)\n", 5149 payload->port, mst_state, avail_slots + payload->time_slots); 5150 return -ENOSPC; 5151 } 5152 5153 if (++payload_count > mgr->max_payloads) { 5154 drm_dbg_atomic(mgr->dev, 5155 "[MST MGR:%p] state %p has too many payloads (max=%d)\n", 5156 mgr, mst_state, mgr->max_payloads); 5157 return -EINVAL; 5158 } 5159 5160 /* Assign a VCPI */ 5161 if (!payload->vcpi) { 5162 payload->vcpi = ffz(mst_state->payload_mask) + 1; 5163 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] assigned VCPI #%d\n", 5164 payload->port, payload->vcpi); 5165 mst_state->payload_mask |= BIT(payload->vcpi - 1); 5166 } 5167 } 5168 5169 if (!payload_count) 5170 mst_state->pbn_div = 0; 5171 5172 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] mst state %p TU pbn_div=%d avail=%d used=%d\n", 5173 mgr, mst_state, mst_state->pbn_div, avail_slots, 5174 mst_state->total_avail_slots - avail_slots); 5175 5176 return 0; 5177} 5178 5179/** 5180 * drm_dp_mst_add_affected_dsc_crtcs 5181 * @state: Pointer to the new struct drm_dp_mst_topology_state 5182 * @mgr: MST topology manager 5183 * 5184 * Whenever there is a change in mst topology 5185 * DSC configuration would have to be recalculated 5186 * therefore we need to trigger modeset on all affected 5187 * CRTCs in that topology 5188 * 5189 * See also: 5190 * drm_dp_mst_atomic_enable_dsc() 5191 */ 5192int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr) 5193{ 5194 struct drm_dp_mst_topology_state *mst_state; 5195 struct drm_dp_mst_atomic_payload *pos; 5196 struct drm_connector *connector; 5197 struct drm_connector_state *conn_state; 5198 struct drm_crtc *crtc; 5199 struct drm_crtc_state *crtc_state; 5200 5201 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 5202 5203 if (IS_ERR(mst_state)) 5204 return PTR_ERR(mst_state); 5205 5206 list_for_each_entry(pos, &mst_state->payloads, next) { 5207 5208 connector = pos->port->connector; 5209 5210 if (!connector) 5211 return -EINVAL; 5212 5213 conn_state = drm_atomic_get_connector_state(state, connector); 5214 5215 if (IS_ERR(conn_state)) 5216 return PTR_ERR(conn_state); 5217 5218 crtc = conn_state->crtc; 5219 5220 if (!crtc) 5221 continue; 5222 5223 if (!drm_dp_mst_dsc_aux_for_port(pos->port)) 5224 continue; 5225 5226 crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc); 5227 5228 if (IS_ERR(crtc_state)) 5229 return PTR_ERR(crtc_state); 5230 5231 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] Setting mode_changed flag on CRTC %p\n", 5232 mgr, crtc); 5233 5234 crtc_state->mode_changed = true; 5235 } 5236 return 0; 5237} 5238EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs); 5239 5240/** 5241 * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off 5242 * @state: Pointer to the new drm_atomic_state 5243 * @port: Pointer to the affected MST Port 5244 * @pbn: Newly recalculated bw required for link with DSC enabled 5245 * @enable: Boolean flag to enable or disable DSC on the port 5246 * 5247 * This function enables DSC on the given Port 5248 * by recalculating its vcpi from pbn provided 5249 * and sets dsc_enable flag to keep track of which 5250 * ports have DSC enabled 5251 * 5252 */ 5253int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state, 5254 struct drm_dp_mst_port *port, 5255 int pbn, bool enable) 5256{ 5257 struct drm_dp_mst_topology_state *mst_state; 5258 struct drm_dp_mst_atomic_payload *payload; 5259 int time_slots = 0; 5260 5261 mst_state = drm_atomic_get_mst_topology_state(state, port->mgr); 5262 if (IS_ERR(mst_state)) 5263 return PTR_ERR(mst_state); 5264 5265 payload = drm_atomic_get_mst_payload_state(mst_state, port); 5266 if (!payload) { 5267 drm_dbg_atomic(state->dev, 5268 "[MST PORT:%p] Couldn't find payload in mst state %p\n", 5269 port, mst_state); 5270 return -EINVAL; 5271 } 5272 5273 if (payload->dsc_enabled == enable) { 5274 drm_dbg_atomic(state->dev, 5275 "[MST PORT:%p] DSC flag is already set to %d, returning %d time slots\n", 5276 port, enable, payload->time_slots); 5277 time_slots = payload->time_slots; 5278 } 5279 5280 if (enable) { 5281 time_slots = drm_dp_atomic_find_time_slots(state, port->mgr, port, pbn); 5282 drm_dbg_atomic(state->dev, 5283 "[MST PORT:%p] Enabling DSC flag, reallocating %d time slots on the port\n", 5284 port, time_slots); 5285 if (time_slots < 0) 5286 return -EINVAL; 5287 } 5288 5289 payload->dsc_enabled = enable; 5290 5291 return time_slots; 5292} 5293EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc); 5294 5295/** 5296 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an 5297 * atomic update is valid 5298 * @state: Pointer to the new &struct drm_dp_mst_topology_state 5299 * 5300 * Checks the given topology state for an atomic update to ensure that it's 5301 * valid. This includes checking whether there's enough bandwidth to support 5302 * the new timeslot allocations in the atomic update. 5303 * 5304 * Any atomic drivers supporting DP MST must make sure to call this after 5305 * checking the rest of their state in their 5306 * &drm_mode_config_funcs.atomic_check() callback. 5307 * 5308 * See also: 5309 * drm_dp_atomic_find_time_slots() 5310 * drm_dp_atomic_release_time_slots() 5311 * 5312 * Returns: 5313 * 5314 * 0 if the new state is valid, negative error code otherwise. 5315 */ 5316int drm_dp_mst_atomic_check(struct drm_atomic_state *state) 5317{ 5318 struct drm_dp_mst_topology_mgr *mgr; 5319 struct drm_dp_mst_topology_state *mst_state; 5320 int i, ret = 0; 5321 5322 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { 5323 if (!mgr->mst_state) 5324 continue; 5325 5326 ret = drm_dp_mst_atomic_check_payload_alloc_limits(mgr, mst_state); 5327 if (ret) 5328 break; 5329 5330 mutex_lock(&mgr->lock); 5331 ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary, 5332 mst_state); 5333 mutex_unlock(&mgr->lock); 5334 if (ret < 0) 5335 break; 5336 else 5337 ret = 0; 5338 } 5339 5340 return ret; 5341} 5342EXPORT_SYMBOL(drm_dp_mst_atomic_check); 5343 5344const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = { 5345 .atomic_duplicate_state = drm_dp_mst_duplicate_state, 5346 .atomic_destroy_state = drm_dp_mst_destroy_state, 5347}; 5348EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs); 5349 5350/** 5351 * drm_atomic_get_mst_topology_state: get MST topology state 5352 * @state: global atomic state 5353 * @mgr: MST topology manager, also the private object in this case 5354 * 5355 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic 5356 * state vtable so that the private object state returned is that of a MST 5357 * topology object. 5358 * 5359 * RETURNS: 5360 * 5361 * The MST topology state or error pointer. 5362 */ 5363struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state, 5364 struct drm_dp_mst_topology_mgr *mgr) 5365{ 5366 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base)); 5367} 5368EXPORT_SYMBOL(drm_atomic_get_mst_topology_state); 5369 5370/** 5371 * drm_atomic_get_old_mst_topology_state: get old MST topology state in atomic state, if any 5372 * @state: global atomic state 5373 * @mgr: MST topology manager, also the private object in this case 5374 * 5375 * This function wraps drm_atomic_get_old_private_obj_state() passing in the MST atomic 5376 * state vtable so that the private object state returned is that of a MST 5377 * topology object. 5378 * 5379 * Returns: 5380 * 5381 * The old MST topology state, or NULL if there's no topology state for this MST mgr 5382 * in the global atomic state 5383 */ 5384struct drm_dp_mst_topology_state * 5385drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state, 5386 struct drm_dp_mst_topology_mgr *mgr) 5387{ 5388 struct drm_private_state *old_priv_state = 5389 drm_atomic_get_old_private_obj_state(state, &mgr->base); 5390 5391 return old_priv_state ? to_dp_mst_topology_state(old_priv_state) : NULL; 5392} 5393EXPORT_SYMBOL(drm_atomic_get_old_mst_topology_state); 5394 5395/** 5396 * drm_atomic_get_new_mst_topology_state: get new MST topology state in atomic state, if any 5397 * @state: global atomic state 5398 * @mgr: MST topology manager, also the private object in this case 5399 * 5400 * This function wraps drm_atomic_get_new_private_obj_state() passing in the MST atomic 5401 * state vtable so that the private object state returned is that of a MST 5402 * topology object. 5403 * 5404 * Returns: 5405 * 5406 * The new MST topology state, or NULL if there's no topology state for this MST mgr 5407 * in the global atomic state 5408 */ 5409struct drm_dp_mst_topology_state * 5410drm_atomic_get_new_mst_topology_state(struct drm_atomic_state *state, 5411 struct drm_dp_mst_topology_mgr *mgr) 5412{ 5413 struct drm_private_state *new_priv_state = 5414 drm_atomic_get_new_private_obj_state(state, &mgr->base); 5415 5416 return new_priv_state ? to_dp_mst_topology_state(new_priv_state) : NULL; 5417} 5418EXPORT_SYMBOL(drm_atomic_get_new_mst_topology_state); 5419 5420/** 5421 * drm_dp_mst_topology_mgr_init - initialise a topology manager 5422 * @mgr: manager struct to initialise 5423 * @dev: device providing this structure - for i2c addition. 5424 * @aux: DP helper aux channel to talk to this device 5425 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit 5426 * @max_payloads: maximum number of payloads this GPU can source 5427 * @conn_base_id: the connector object ID the MST device is connected to. 5428 * 5429 * Return 0 for success, or negative error code on failure 5430 */ 5431int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, 5432 struct drm_device *dev, struct drm_dp_aux *aux, 5433 int max_dpcd_transaction_bytes, int max_payloads, 5434 int conn_base_id) 5435{ 5436 struct drm_dp_mst_topology_state *mst_state; 5437 5438 rw_init(&mgr->lock, "mst"); 5439 rw_init(&mgr->qlock, "mstq"); 5440 rw_init(&mgr->delayed_destroy_lock, "mstdc"); 5441 rw_init(&mgr->up_req_lock, "mstup"); 5442 rw_init(&mgr->probe_lock, "mstprb"); 5443#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 5444 rw_init(&mgr->topology_ref_history_lock, "msttr"); 5445 stack_depot_init(); 5446#endif 5447 INIT_LIST_HEAD(&mgr->tx_msg_downq); 5448 INIT_LIST_HEAD(&mgr->destroy_port_list); 5449 INIT_LIST_HEAD(&mgr->destroy_branch_device_list); 5450 INIT_LIST_HEAD(&mgr->up_req_list); 5451 5452 /* 5453 * delayed_destroy_work will be queued on a dedicated WQ, so that any 5454 * requeuing will be also flushed when deiniting the topology manager. 5455 */ 5456 mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0); 5457 if (mgr->delayed_destroy_wq == NULL) 5458 return -ENOMEM; 5459 5460 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work); 5461 INIT_WORK(&mgr->tx_work, drm_dp_tx_work); 5462 INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work); 5463 INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work); 5464 init_waitqueue_head(&mgr->tx_waitq); 5465 mgr->dev = dev; 5466 mgr->aux = aux; 5467 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes; 5468 mgr->max_payloads = max_payloads; 5469 mgr->conn_base_id = conn_base_id; 5470 5471 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL); 5472 if (mst_state == NULL) 5473 return -ENOMEM; 5474 5475 mst_state->total_avail_slots = 63; 5476 mst_state->start_slot = 1; 5477 5478 mst_state->mgr = mgr; 5479 INIT_LIST_HEAD(&mst_state->payloads); 5480 5481 drm_atomic_private_obj_init(dev, &mgr->base, 5482 &mst_state->base, 5483 &drm_dp_mst_topology_state_funcs); 5484 5485 return 0; 5486} 5487EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init); 5488 5489/** 5490 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager. 5491 * @mgr: manager to destroy 5492 */ 5493void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr) 5494{ 5495 drm_dp_mst_topology_mgr_set_mst(mgr, false); 5496 flush_work(&mgr->work); 5497 /* The following will also drain any requeued work on the WQ. */ 5498 if (mgr->delayed_destroy_wq) { 5499 destroy_workqueue(mgr->delayed_destroy_wq); 5500 mgr->delayed_destroy_wq = NULL; 5501 } 5502 mgr->dev = NULL; 5503 mgr->aux = NULL; 5504 drm_atomic_private_obj_fini(&mgr->base); 5505 mgr->funcs = NULL; 5506 5507 mutex_destroy(&mgr->delayed_destroy_lock); 5508 mutex_destroy(&mgr->qlock); 5509 mutex_destroy(&mgr->lock); 5510 mutex_destroy(&mgr->up_req_lock); 5511 mutex_destroy(&mgr->probe_lock); 5512#if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 5513 mutex_destroy(&mgr->topology_ref_history_lock); 5514#endif 5515} 5516EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy); 5517 5518static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num) 5519{ 5520 int i; 5521 5522 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS) 5523 return false; 5524 5525 for (i = 0; i < num - 1; i++) { 5526 if (msgs[i].flags & I2C_M_RD || 5527 msgs[i].len > 0xff) 5528 return false; 5529 } 5530 5531 return msgs[num - 1].flags & I2C_M_RD && 5532 msgs[num - 1].len <= 0xff; 5533} 5534 5535static bool remote_i2c_write_ok(const struct i2c_msg msgs[], int num) 5536{ 5537 int i; 5538 5539 for (i = 0; i < num - 1; i++) { 5540 if (msgs[i].flags & I2C_M_RD || !(msgs[i].flags & I2C_M_STOP) || 5541 msgs[i].len > 0xff) 5542 return false; 5543 } 5544 5545 return !(msgs[num - 1].flags & I2C_M_RD) && msgs[num - 1].len <= 0xff; 5546} 5547 5548static int drm_dp_mst_i2c_read(struct drm_dp_mst_branch *mstb, 5549 struct drm_dp_mst_port *port, 5550 struct i2c_msg *msgs, int num) 5551{ 5552 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5553 unsigned int i; 5554 struct drm_dp_sideband_msg_req_body msg; 5555 struct drm_dp_sideband_msg_tx *txmsg = NULL; 5556 int ret; 5557 5558 memset(&msg, 0, sizeof(msg)); 5559 msg.req_type = DP_REMOTE_I2C_READ; 5560 msg.u.i2c_read.num_transactions = num - 1; 5561 msg.u.i2c_read.port_number = port->port_num; 5562 for (i = 0; i < num - 1; i++) { 5563 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr; 5564 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len; 5565 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf; 5566 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP); 5567 } 5568 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr; 5569 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len; 5570 5571 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 5572 if (!txmsg) { 5573 ret = -ENOMEM; 5574 goto out; 5575 } 5576 5577 txmsg->dst = mstb; 5578 drm_dp_encode_sideband_req(&msg, txmsg); 5579 5580 drm_dp_queue_down_tx(mgr, txmsg); 5581 5582 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 5583 if (ret > 0) { 5584 5585 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 5586 ret = -EREMOTEIO; 5587 goto out; 5588 } 5589 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) { 5590 ret = -EIO; 5591 goto out; 5592 } 5593 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len); 5594 ret = num; 5595 } 5596out: 5597 kfree(txmsg); 5598 return ret; 5599} 5600 5601static int drm_dp_mst_i2c_write(struct drm_dp_mst_branch *mstb, 5602 struct drm_dp_mst_port *port, 5603 struct i2c_msg *msgs, int num) 5604{ 5605 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5606 unsigned int i; 5607 struct drm_dp_sideband_msg_req_body msg; 5608 struct drm_dp_sideband_msg_tx *txmsg = NULL; 5609 int ret; 5610 5611 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 5612 if (!txmsg) { 5613 ret = -ENOMEM; 5614 goto out; 5615 } 5616 for (i = 0; i < num; i++) { 5617 memset(&msg, 0, sizeof(msg)); 5618 msg.req_type = DP_REMOTE_I2C_WRITE; 5619 msg.u.i2c_write.port_number = port->port_num; 5620 msg.u.i2c_write.write_i2c_device_id = msgs[i].addr; 5621 msg.u.i2c_write.num_bytes = msgs[i].len; 5622 msg.u.i2c_write.bytes = msgs[i].buf; 5623 5624 memset(txmsg, 0, sizeof(*txmsg)); 5625 txmsg->dst = mstb; 5626 5627 drm_dp_encode_sideband_req(&msg, txmsg); 5628 drm_dp_queue_down_tx(mgr, txmsg); 5629 5630 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 5631 if (ret > 0) { 5632 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 5633 ret = -EREMOTEIO; 5634 goto out; 5635 } 5636 } else { 5637 goto out; 5638 } 5639 } 5640 ret = num; 5641out: 5642 kfree(txmsg); 5643 return ret; 5644} 5645 5646/* I2C device */ 5647static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, 5648 struct i2c_msg *msgs, int num) 5649{ 5650 struct drm_dp_aux *aux = adapter->algo_data; 5651 struct drm_dp_mst_port *port = 5652 container_of(aux, struct drm_dp_mst_port, aux); 5653 struct drm_dp_mst_branch *mstb; 5654 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5655 int ret; 5656 5657 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 5658 if (!mstb) 5659 return -EREMOTEIO; 5660 5661 if (remote_i2c_read_ok(msgs, num)) { 5662 ret = drm_dp_mst_i2c_read(mstb, port, msgs, num); 5663 } else if (remote_i2c_write_ok(msgs, num)) { 5664 ret = drm_dp_mst_i2c_write(mstb, port, msgs, num); 5665 } else { 5666 drm_dbg_kms(mgr->dev, "Unsupported I2C transaction for MST device\n"); 5667 ret = -EIO; 5668 } 5669 5670 drm_dp_mst_topology_put_mstb(mstb); 5671 return ret; 5672} 5673 5674static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter) 5675{ 5676 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | 5677 I2C_FUNC_SMBUS_READ_BLOCK_DATA | 5678 I2C_FUNC_SMBUS_BLOCK_PROC_CALL | 5679 I2C_FUNC_10BIT_ADDR; 5680} 5681 5682static const struct i2c_algorithm drm_dp_mst_i2c_algo = { 5683 .functionality = drm_dp_mst_i2c_functionality, 5684 .master_xfer = drm_dp_mst_i2c_xfer, 5685}; 5686 5687/** 5688 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX 5689 * @port: The port to add the I2C bus on 5690 * 5691 * Returns 0 on success or a negative error code on failure. 5692 */ 5693static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port) 5694{ 5695 struct drm_dp_aux *aux = &port->aux; 5696#ifdef __linux__ 5697 struct device *parent_dev = port->mgr->dev->dev; 5698#endif 5699 5700 aux->ddc.algo = &drm_dp_mst_i2c_algo; 5701 aux->ddc.algo_data = aux; 5702 aux->ddc.retries = 3; 5703 5704#ifdef __linux__ 5705 aux->ddc.class = I2C_CLASS_DDC; 5706 aux->ddc.owner = THIS_MODULE; 5707 /* FIXME: set the kdev of the port's connector as parent */ 5708 aux->ddc.dev.parent = parent_dev; 5709 aux->ddc.dev.of_node = parent_dev->of_node; 5710#endif 5711 5712 strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev), 5713 sizeof(aux->ddc.name)); 5714 5715 return i2c_add_adapter(&aux->ddc); 5716} 5717 5718/** 5719 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter 5720 * @port: The port to remove the I2C bus from 5721 */ 5722static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port) 5723{ 5724 i2c_del_adapter(&port->aux.ddc); 5725} 5726 5727/** 5728 * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device 5729 * @port: The port to check 5730 * 5731 * A single physical MST hub object can be represented in the topology 5732 * by multiple branches, with virtual ports between those branches. 5733 * 5734 * As of DP1.4, An MST hub with internal (virtual) ports must expose 5735 * certain DPCD registers over those ports. See sections 2.6.1.1.1 5736 * and 2.6.1.1.2 of Display Port specification v1.4 for details. 5737 * 5738 * May acquire mgr->lock 5739 * 5740 * Returns: 5741 * true if the port is a virtual DP peer device, false otherwise 5742 */ 5743static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port) 5744{ 5745 struct drm_dp_mst_port *downstream_port; 5746 5747 if (!port || port->dpcd_rev < DP_DPCD_REV_14) 5748 return false; 5749 5750 /* Virtual DP Sink (Internal Display Panel) */ 5751 if (port->port_num >= 8) 5752 return true; 5753 5754 /* DP-to-HDMI Protocol Converter */ 5755 if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV && 5756 !port->mcs && 5757 port->ldps) 5758 return true; 5759 5760 /* DP-to-DP */ 5761 mutex_lock(&port->mgr->lock); 5762 if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING && 5763 port->mstb && 5764 port->mstb->num_ports == 2) { 5765 list_for_each_entry(downstream_port, &port->mstb->ports, next) { 5766 if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK && 5767 !downstream_port->input) { 5768 mutex_unlock(&port->mgr->lock); 5769 return true; 5770 } 5771 } 5772 } 5773 mutex_unlock(&port->mgr->lock); 5774 5775 return false; 5776} 5777 5778/** 5779 * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC 5780 * @port: The port to check. A leaf of the MST tree with an attached display. 5781 * 5782 * Depending on the situation, DSC may be enabled via the endpoint aux, 5783 * the immediately upstream aux, or the connector's physical aux. 5784 * 5785 * This is both the correct aux to read DSC_CAPABILITY and the 5786 * correct aux to write DSC_ENABLED. 5787 * 5788 * This operation can be expensive (up to four aux reads), so 5789 * the caller should cache the return. 5790 * 5791 * Returns: 5792 * NULL if DSC cannot be enabled on this port, otherwise the aux device 5793 */ 5794struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port) 5795{ 5796 struct drm_dp_mst_port *immediate_upstream_port; 5797 struct drm_dp_mst_port *fec_port; 5798 struct drm_dp_desc desc = {}; 5799 u8 endpoint_fec; 5800 u8 endpoint_dsc; 5801 5802 if (!port) 5803 return NULL; 5804 5805 if (port->parent->port_parent) 5806 immediate_upstream_port = port->parent->port_parent; 5807 else 5808 immediate_upstream_port = NULL; 5809 5810 fec_port = immediate_upstream_port; 5811 while (fec_port) { 5812 /* 5813 * Each physical link (i.e. not a virtual port) between the 5814 * output and the primary device must support FEC 5815 */ 5816 if (!drm_dp_mst_is_virtual_dpcd(fec_port) && 5817 !fec_port->fec_capable) 5818 return NULL; 5819 5820 fec_port = fec_port->parent->port_parent; 5821 } 5822 5823 /* DP-to-DP peer device */ 5824 if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) { 5825 u8 upstream_dsc; 5826 5827 if (drm_dp_dpcd_read(&port->aux, 5828 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1) 5829 return NULL; 5830 if (drm_dp_dpcd_read(&port->aux, 5831 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1) 5832 return NULL; 5833 if (drm_dp_dpcd_read(&immediate_upstream_port->aux, 5834 DP_DSC_SUPPORT, &upstream_dsc, 1) != 1) 5835 return NULL; 5836 5837 /* Enpoint decompression with DP-to-DP peer device */ 5838 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) && 5839 (endpoint_fec & DP_FEC_CAPABLE) && 5840 (upstream_dsc & DP_DSC_PASSTHROUGH_IS_SUPPORTED)) { 5841 port->passthrough_aux = &immediate_upstream_port->aux; 5842 return &port->aux; 5843 } 5844 5845 /* Virtual DPCD decompression with DP-to-DP peer device */ 5846 return &immediate_upstream_port->aux; 5847 } 5848 5849 /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */ 5850 if (drm_dp_mst_is_virtual_dpcd(port)) 5851 return &port->aux; 5852 5853 /* 5854 * Synaptics quirk 5855 * Applies to ports for which: 5856 * - Physical aux has Synaptics OUI 5857 * - DPv1.4 or higher 5858 * - Port is on primary branch device 5859 * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG) 5860 */ 5861 if (drm_dp_read_desc(port->mgr->aux, &desc, true)) 5862 return NULL; 5863 5864 if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) && 5865 port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 && 5866 port->parent == port->mgr->mst_primary) { 5867 u8 dpcd_ext[DP_RECEIVER_CAP_SIZE]; 5868 5869 if (drm_dp_read_dpcd_caps(port->mgr->aux, dpcd_ext) < 0) 5870 return NULL; 5871 5872 if ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT) && 5873 ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) 5874 != DP_DWN_STRM_PORT_TYPE_ANALOG)) 5875 return port->mgr->aux; 5876 } 5877 5878 /* 5879 * The check below verifies if the MST sink 5880 * connected to the GPU is capable of DSC - 5881 * therefore the endpoint needs to be 5882 * both DSC and FEC capable. 5883 */ 5884 if (drm_dp_dpcd_read(&port->aux, 5885 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1) 5886 return NULL; 5887 if (drm_dp_dpcd_read(&port->aux, 5888 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1) 5889 return NULL; 5890 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) && 5891 (endpoint_fec & DP_FEC_CAPABLE)) 5892 return &port->aux; 5893 5894 return NULL; 5895} 5896EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port); 5897