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 */ 59 struct 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 65 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, 66 char *buf); 67 68 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port); 69 70 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, 71 int id, u8 start_slot, u8 num_slots); 72 73 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, 74 struct drm_dp_mst_port *port, 75 int offset, int size, u8 *bytes); 76 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, 77 struct drm_dp_mst_port *port, 78 int offset, int size, u8 *bytes); 79 80 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 81 struct drm_dp_mst_branch *mstb); 82 83 static void 84 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr, 85 struct drm_dp_mst_branch *mstb); 86 87 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, 88 struct drm_dp_mst_branch *mstb, 89 struct drm_dp_mst_port *port); 90 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, 91 u8 *guid); 92 93 static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port); 94 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port); 95 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr); 96 97 static 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 103 104 static 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 134 135 static 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 159 160 static 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 } 176 177 static int 178 drm_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 */ 197 static 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 } 230 231 static 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 } 264 static 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 } 271 272 static 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 } 291 292 static 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 if (hdr->msg_len < 1) /* min space for body CRC */ 323 return false; 324 325 idx++; 326 hdr->somt = (buf[idx] >> 7) & 0x1; 327 hdr->eomt = (buf[idx] >> 6) & 0x1; 328 hdr->seqno = (buf[idx] >> 4) & 0x1; 329 idx++; 330 *hdrlen = idx; 331 return true; 332 } 333 334 void 335 drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req, 336 struct drm_dp_sideband_msg_tx *raw) 337 { 338 int idx = 0; 339 int i; 340 u8 *buf = raw->msg; 341 342 buf[idx++] = req->req_type & 0x7f; 343 344 switch (req->req_type) { 345 case DP_ENUM_PATH_RESOURCES: 346 case DP_POWER_DOWN_PHY: 347 case DP_POWER_UP_PHY: 348 buf[idx] = (req->u.port_num.port_number & 0xf) << 4; 349 idx++; 350 break; 351 case DP_ALLOCATE_PAYLOAD: 352 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 | 353 (req->u.allocate_payload.number_sdp_streams & 0xf); 354 idx++; 355 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f); 356 idx++; 357 buf[idx] = (req->u.allocate_payload.pbn >> 8); 358 idx++; 359 buf[idx] = (req->u.allocate_payload.pbn & 0xff); 360 idx++; 361 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) { 362 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) | 363 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf); 364 idx++; 365 } 366 if (req->u.allocate_payload.number_sdp_streams & 1) { 367 i = req->u.allocate_payload.number_sdp_streams - 1; 368 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4; 369 idx++; 370 } 371 break; 372 case DP_QUERY_PAYLOAD: 373 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4; 374 idx++; 375 buf[idx] = (req->u.query_payload.vcpi & 0x7f); 376 idx++; 377 break; 378 case DP_REMOTE_DPCD_READ: 379 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4; 380 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf; 381 idx++; 382 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8; 383 idx++; 384 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff); 385 idx++; 386 buf[idx] = (req->u.dpcd_read.num_bytes); 387 idx++; 388 break; 389 390 case DP_REMOTE_DPCD_WRITE: 391 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4; 392 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf; 393 idx++; 394 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8; 395 idx++; 396 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff); 397 idx++; 398 buf[idx] = (req->u.dpcd_write.num_bytes); 399 idx++; 400 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes); 401 idx += req->u.dpcd_write.num_bytes; 402 break; 403 case DP_REMOTE_I2C_READ: 404 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4; 405 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3); 406 idx++; 407 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) { 408 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f; 409 idx++; 410 buf[idx] = req->u.i2c_read.transactions[i].num_bytes; 411 idx++; 412 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes); 413 idx += req->u.i2c_read.transactions[i].num_bytes; 414 415 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4; 416 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf); 417 idx++; 418 } 419 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f; 420 idx++; 421 buf[idx] = (req->u.i2c_read.num_bytes_read); 422 idx++; 423 break; 424 425 case DP_REMOTE_I2C_WRITE: 426 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4; 427 idx++; 428 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f; 429 idx++; 430 buf[idx] = (req->u.i2c_write.num_bytes); 431 idx++; 432 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes); 433 idx += req->u.i2c_write.num_bytes; 434 break; 435 case DP_QUERY_STREAM_ENC_STATUS: { 436 const struct drm_dp_query_stream_enc_status *msg; 437 438 msg = &req->u.enc_status; 439 buf[idx] = msg->stream_id; 440 idx++; 441 memcpy(&buf[idx], msg->client_id, sizeof(msg->client_id)); 442 idx += sizeof(msg->client_id); 443 buf[idx] = 0; 444 buf[idx] |= FIELD_PREP(GENMASK(1, 0), msg->stream_event); 445 buf[idx] |= msg->valid_stream_event ? BIT(2) : 0; 446 buf[idx] |= FIELD_PREP(GENMASK(4, 3), msg->stream_behavior); 447 buf[idx] |= msg->valid_stream_behavior ? BIT(5) : 0; 448 idx++; 449 } 450 break; 451 } 452 raw->cur_len = idx; 453 } 454 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req); 455 456 /* Decode a sideband request we've encoded, mainly used for debugging */ 457 int 458 drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw, 459 struct drm_dp_sideband_msg_req_body *req) 460 { 461 const u8 *buf = raw->msg; 462 int i, idx = 0; 463 464 req->req_type = buf[idx++] & 0x7f; 465 switch (req->req_type) { 466 case DP_ENUM_PATH_RESOURCES: 467 case DP_POWER_DOWN_PHY: 468 case DP_POWER_UP_PHY: 469 req->u.port_num.port_number = (buf[idx] >> 4) & 0xf; 470 break; 471 case DP_ALLOCATE_PAYLOAD: 472 { 473 struct drm_dp_allocate_payload *a = 474 &req->u.allocate_payload; 475 476 a->number_sdp_streams = buf[idx] & 0xf; 477 a->port_number = (buf[idx] >> 4) & 0xf; 478 479 WARN_ON(buf[++idx] & 0x80); 480 a->vcpi = buf[idx] & 0x7f; 481 482 a->pbn = buf[++idx] << 8; 483 a->pbn |= buf[++idx]; 484 485 idx++; 486 for (i = 0; i < a->number_sdp_streams; i++) { 487 a->sdp_stream_sink[i] = 488 (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf; 489 } 490 } 491 break; 492 case DP_QUERY_PAYLOAD: 493 req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf; 494 WARN_ON(buf[++idx] & 0x80); 495 req->u.query_payload.vcpi = buf[idx] & 0x7f; 496 break; 497 case DP_REMOTE_DPCD_READ: 498 { 499 struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read; 500 501 r->port_number = (buf[idx] >> 4) & 0xf; 502 503 r->dpcd_address = (buf[idx] << 16) & 0xf0000; 504 r->dpcd_address |= (buf[++idx] << 8) & 0xff00; 505 r->dpcd_address |= buf[++idx] & 0xff; 506 507 r->num_bytes = buf[++idx]; 508 } 509 break; 510 case DP_REMOTE_DPCD_WRITE: 511 { 512 struct drm_dp_remote_dpcd_write *w = 513 &req->u.dpcd_write; 514 515 w->port_number = (buf[idx] >> 4) & 0xf; 516 517 w->dpcd_address = (buf[idx] << 16) & 0xf0000; 518 w->dpcd_address |= (buf[++idx] << 8) & 0xff00; 519 w->dpcd_address |= buf[++idx] & 0xff; 520 521 w->num_bytes = buf[++idx]; 522 523 w->bytes = kmemdup(&buf[++idx], w->num_bytes, 524 GFP_KERNEL); 525 if (!w->bytes) 526 return -ENOMEM; 527 } 528 break; 529 case DP_REMOTE_I2C_READ: 530 { 531 struct drm_dp_remote_i2c_read *r = &req->u.i2c_read; 532 struct drm_dp_remote_i2c_read_tx *tx; 533 bool failed = false; 534 535 r->num_transactions = buf[idx] & 0x3; 536 r->port_number = (buf[idx] >> 4) & 0xf; 537 for (i = 0; i < r->num_transactions; i++) { 538 tx = &r->transactions[i]; 539 540 tx->i2c_dev_id = buf[++idx] & 0x7f; 541 tx->num_bytes = buf[++idx]; 542 tx->bytes = kmemdup(&buf[++idx], 543 tx->num_bytes, 544 GFP_KERNEL); 545 if (!tx->bytes) { 546 failed = true; 547 break; 548 } 549 idx += tx->num_bytes; 550 tx->no_stop_bit = (buf[idx] >> 5) & 0x1; 551 tx->i2c_transaction_delay = buf[idx] & 0xf; 552 } 553 554 if (failed) { 555 for (i = 0; i < r->num_transactions; i++) { 556 tx = &r->transactions[i]; 557 kfree(tx->bytes); 558 } 559 return -ENOMEM; 560 } 561 562 r->read_i2c_device_id = buf[++idx] & 0x7f; 563 r->num_bytes_read = buf[++idx]; 564 } 565 break; 566 case DP_REMOTE_I2C_WRITE: 567 { 568 struct drm_dp_remote_i2c_write *w = &req->u.i2c_write; 569 570 w->port_number = (buf[idx] >> 4) & 0xf; 571 w->write_i2c_device_id = buf[++idx] & 0x7f; 572 w->num_bytes = buf[++idx]; 573 w->bytes = kmemdup(&buf[++idx], w->num_bytes, 574 GFP_KERNEL); 575 if (!w->bytes) 576 return -ENOMEM; 577 } 578 break; 579 case DP_QUERY_STREAM_ENC_STATUS: 580 req->u.enc_status.stream_id = buf[idx++]; 581 for (i = 0; i < sizeof(req->u.enc_status.client_id); i++) 582 req->u.enc_status.client_id[i] = buf[idx++]; 583 584 req->u.enc_status.stream_event = FIELD_GET(GENMASK(1, 0), 585 buf[idx]); 586 req->u.enc_status.valid_stream_event = FIELD_GET(BIT(2), 587 buf[idx]); 588 req->u.enc_status.stream_behavior = FIELD_GET(GENMASK(4, 3), 589 buf[idx]); 590 req->u.enc_status.valid_stream_behavior = FIELD_GET(BIT(5), 591 buf[idx]); 592 break; 593 } 594 595 return 0; 596 } 597 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req); 598 599 void 600 drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req, 601 int indent, struct drm_printer *printer) 602 { 603 int i; 604 605 #define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__) 606 if (req->req_type == DP_LINK_ADDRESS) { 607 /* No contents to print */ 608 P("type=%s\n", drm_dp_mst_req_type_str(req->req_type)); 609 return; 610 } 611 612 P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type)); 613 indent++; 614 615 switch (req->req_type) { 616 case DP_ENUM_PATH_RESOURCES: 617 case DP_POWER_DOWN_PHY: 618 case DP_POWER_UP_PHY: 619 P("port=%d\n", req->u.port_num.port_number); 620 break; 621 case DP_ALLOCATE_PAYLOAD: 622 P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n", 623 req->u.allocate_payload.port_number, 624 req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn, 625 req->u.allocate_payload.number_sdp_streams, 626 req->u.allocate_payload.number_sdp_streams, 627 req->u.allocate_payload.sdp_stream_sink); 628 break; 629 case DP_QUERY_PAYLOAD: 630 P("port=%d vcpi=%d\n", 631 req->u.query_payload.port_number, 632 req->u.query_payload.vcpi); 633 break; 634 case DP_REMOTE_DPCD_READ: 635 P("port=%d dpcd_addr=%05x len=%d\n", 636 req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address, 637 req->u.dpcd_read.num_bytes); 638 break; 639 case DP_REMOTE_DPCD_WRITE: 640 P("port=%d addr=%05x len=%d: %*ph\n", 641 req->u.dpcd_write.port_number, 642 req->u.dpcd_write.dpcd_address, 643 req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes, 644 req->u.dpcd_write.bytes); 645 break; 646 case DP_REMOTE_I2C_READ: 647 P("port=%d num_tx=%d id=%d size=%d:\n", 648 req->u.i2c_read.port_number, 649 req->u.i2c_read.num_transactions, 650 req->u.i2c_read.read_i2c_device_id, 651 req->u.i2c_read.num_bytes_read); 652 653 indent++; 654 for (i = 0; i < req->u.i2c_read.num_transactions; i++) { 655 const struct drm_dp_remote_i2c_read_tx *rtx = 656 &req->u.i2c_read.transactions[i]; 657 658 P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n", 659 i, rtx->i2c_dev_id, rtx->num_bytes, 660 rtx->no_stop_bit, rtx->i2c_transaction_delay, 661 rtx->num_bytes, rtx->bytes); 662 } 663 break; 664 case DP_REMOTE_I2C_WRITE: 665 P("port=%d id=%d size=%d: %*ph\n", 666 req->u.i2c_write.port_number, 667 req->u.i2c_write.write_i2c_device_id, 668 req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes, 669 req->u.i2c_write.bytes); 670 break; 671 case DP_QUERY_STREAM_ENC_STATUS: 672 P("stream_id=%u client_id=%*ph stream_event=%x " 673 "valid_event=%d stream_behavior=%x valid_behavior=%d", 674 req->u.enc_status.stream_id, 675 (int)ARRAY_SIZE(req->u.enc_status.client_id), 676 req->u.enc_status.client_id, req->u.enc_status.stream_event, 677 req->u.enc_status.valid_stream_event, 678 req->u.enc_status.stream_behavior, 679 req->u.enc_status.valid_stream_behavior); 680 break; 681 default: 682 P("???\n"); 683 break; 684 } 685 #undef P 686 } 687 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body); 688 689 static inline void 690 drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p, 691 const struct drm_dp_sideband_msg_tx *txmsg) 692 { 693 struct drm_dp_sideband_msg_req_body req; 694 char buf[64]; 695 int ret; 696 int i; 697 698 drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf, 699 sizeof(buf)); 700 drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n", 701 txmsg->cur_offset, txmsg->cur_len, txmsg->seqno, 702 drm_dp_mst_sideband_tx_state_str(txmsg->state), 703 txmsg->path_msg, buf); 704 705 ret = drm_dp_decode_sideband_req(txmsg, &req); 706 if (ret) { 707 drm_printf(p, "<failed to decode sideband req: %d>\n", ret); 708 return; 709 } 710 drm_dp_dump_sideband_msg_req_body(&req, 1, p); 711 712 switch (req.req_type) { 713 case DP_REMOTE_DPCD_WRITE: 714 kfree(req.u.dpcd_write.bytes); 715 break; 716 case DP_REMOTE_I2C_READ: 717 for (i = 0; i < req.u.i2c_read.num_transactions; i++) 718 kfree(req.u.i2c_read.transactions[i].bytes); 719 break; 720 case DP_REMOTE_I2C_WRITE: 721 kfree(req.u.i2c_write.bytes); 722 break; 723 } 724 } 725 726 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len) 727 { 728 u8 crc4; 729 730 crc4 = drm_dp_msg_data_crc4(msg, len); 731 msg[len] = crc4; 732 } 733 734 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep, 735 struct drm_dp_sideband_msg_tx *raw) 736 { 737 int idx = 0; 738 u8 *buf = raw->msg; 739 740 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f); 741 742 raw->cur_len = idx; 743 } 744 745 static int drm_dp_sideband_msg_set_header(struct drm_dp_sideband_msg_rx *msg, 746 struct drm_dp_sideband_msg_hdr *hdr, 747 u8 hdrlen) 748 { 749 /* 750 * ignore out-of-order messages or messages that are part of a 751 * failed transaction 752 */ 753 if (!hdr->somt && !msg->have_somt) 754 return false; 755 756 /* get length contained in this portion */ 757 msg->curchunk_idx = 0; 758 msg->curchunk_len = hdr->msg_len; 759 msg->curchunk_hdrlen = hdrlen; 760 761 /* we have already gotten an somt - don't bother parsing */ 762 if (hdr->somt && msg->have_somt) 763 return false; 764 765 if (hdr->somt) { 766 memcpy(&msg->initial_hdr, hdr, 767 sizeof(struct drm_dp_sideband_msg_hdr)); 768 msg->have_somt = true; 769 } 770 if (hdr->eomt) 771 msg->have_eomt = true; 772 773 return true; 774 } 775 776 /* this adds a chunk of msg to the builder to get the final msg */ 777 static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx *msg, 778 u8 *replybuf, u8 replybuflen) 779 { 780 u8 crc4; 781 782 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen); 783 msg->curchunk_idx += replybuflen; 784 785 if (msg->curchunk_idx >= msg->curchunk_len) { 786 /* do CRC */ 787 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1); 788 if (crc4 != msg->chunk[msg->curchunk_len - 1]) 789 print_hex_dump(KERN_DEBUG, "wrong crc", 790 DUMP_PREFIX_NONE, 16, 1, 791 msg->chunk, msg->curchunk_len, false); 792 /* copy chunk into bigger msg */ 793 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1); 794 msg->curlen += msg->curchunk_len - 1; 795 } 796 return true; 797 } 798 799 static bool drm_dp_sideband_parse_link_address(const struct drm_dp_mst_topology_mgr *mgr, 800 struct drm_dp_sideband_msg_rx *raw, 801 struct drm_dp_sideband_msg_reply_body *repmsg) 802 { 803 int idx = 1; 804 int i; 805 806 memcpy(repmsg->u.link_addr.guid, &raw->msg[idx], 16); 807 idx += 16; 808 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf; 809 idx++; 810 if (idx > raw->curlen) 811 goto fail_len; 812 for (i = 0; i < repmsg->u.link_addr.nports; i++) { 813 if (raw->msg[idx] & 0x80) 814 repmsg->u.link_addr.ports[i].input_port = 1; 815 816 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7; 817 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf); 818 819 idx++; 820 if (idx > raw->curlen) 821 goto fail_len; 822 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1; 823 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1; 824 if (repmsg->u.link_addr.ports[i].input_port == 0) 825 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1; 826 idx++; 827 if (idx > raw->curlen) 828 goto fail_len; 829 if (repmsg->u.link_addr.ports[i].input_port == 0) { 830 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]); 831 idx++; 832 if (idx > raw->curlen) 833 goto fail_len; 834 memcpy(repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx], 16); 835 idx += 16; 836 if (idx > raw->curlen) 837 goto fail_len; 838 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf; 839 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf); 840 idx++; 841 842 } 843 if (idx > raw->curlen) 844 goto fail_len; 845 } 846 847 return true; 848 fail_len: 849 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); 850 return false; 851 } 852 853 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw, 854 struct drm_dp_sideband_msg_reply_body *repmsg) 855 { 856 int idx = 1; 857 858 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf; 859 idx++; 860 if (idx > raw->curlen) 861 goto fail_len; 862 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx]; 863 idx++; 864 if (idx > raw->curlen) 865 goto fail_len; 866 867 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes); 868 return true; 869 fail_len: 870 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); 871 return false; 872 } 873 874 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw, 875 struct drm_dp_sideband_msg_reply_body *repmsg) 876 { 877 int idx = 1; 878 879 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf; 880 idx++; 881 if (idx > raw->curlen) 882 goto fail_len; 883 return true; 884 fail_len: 885 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen); 886 return false; 887 } 888 889 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw, 890 struct drm_dp_sideband_msg_reply_body *repmsg) 891 { 892 int idx = 1; 893 894 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf); 895 idx++; 896 if (idx > raw->curlen) 897 goto fail_len; 898 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx]; 899 idx++; 900 /* TODO check */ 901 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes); 902 return true; 903 fail_len: 904 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen); 905 return false; 906 } 907 908 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw, 909 struct drm_dp_sideband_msg_reply_body *repmsg) 910 { 911 int idx = 1; 912 913 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf; 914 repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1; 915 idx++; 916 if (idx > raw->curlen) 917 goto fail_len; 918 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 919 idx += 2; 920 if (idx > raw->curlen) 921 goto fail_len; 922 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 923 idx += 2; 924 if (idx > raw->curlen) 925 goto fail_len; 926 return true; 927 fail_len: 928 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen); 929 return false; 930 } 931 932 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw, 933 struct drm_dp_sideband_msg_reply_body *repmsg) 934 { 935 int idx = 1; 936 937 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf; 938 idx++; 939 if (idx > raw->curlen) 940 goto fail_len; 941 repmsg->u.allocate_payload.vcpi = raw->msg[idx]; 942 idx++; 943 if (idx > raw->curlen) 944 goto fail_len; 945 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 946 idx += 2; 947 if (idx > raw->curlen) 948 goto fail_len; 949 return true; 950 fail_len: 951 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen); 952 return false; 953 } 954 955 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw, 956 struct drm_dp_sideband_msg_reply_body *repmsg) 957 { 958 int idx = 1; 959 960 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf; 961 idx++; 962 if (idx > raw->curlen) 963 goto fail_len; 964 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); 965 idx += 2; 966 if (idx > raw->curlen) 967 goto fail_len; 968 return true; 969 fail_len: 970 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen); 971 return false; 972 } 973 974 static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw, 975 struct drm_dp_sideband_msg_reply_body *repmsg) 976 { 977 int idx = 1; 978 979 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf; 980 idx++; 981 if (idx > raw->curlen) { 982 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n", 983 idx, raw->curlen); 984 return false; 985 } 986 return true; 987 } 988 989 static bool 990 drm_dp_sideband_parse_query_stream_enc_status( 991 struct drm_dp_sideband_msg_rx *raw, 992 struct drm_dp_sideband_msg_reply_body *repmsg) 993 { 994 struct drm_dp_query_stream_enc_status_ack_reply *reply; 995 996 reply = &repmsg->u.enc_status; 997 998 reply->stream_id = raw->msg[3]; 999 1000 reply->reply_signed = raw->msg[2] & BIT(0); 1001 1002 /* 1003 * NOTE: It's my impression from reading the spec that the below parsing 1004 * is correct. However I noticed while testing with an HDCP 1.4 display 1005 * through an HDCP 2.2 hub that only bit 3 was set. In that case, I 1006 * would expect both bits to be set. So keep the parsing following the 1007 * spec, but beware reality might not match the spec (at least for some 1008 * configurations). 1009 */ 1010 reply->hdcp_1x_device_present = raw->msg[2] & BIT(4); 1011 reply->hdcp_2x_device_present = raw->msg[2] & BIT(3); 1012 1013 reply->query_capable_device_present = raw->msg[2] & BIT(5); 1014 reply->legacy_device_present = raw->msg[2] & BIT(6); 1015 reply->unauthorizable_device_present = raw->msg[2] & BIT(7); 1016 1017 reply->auth_completed = !!(raw->msg[1] & BIT(3)); 1018 reply->encryption_enabled = !!(raw->msg[1] & BIT(4)); 1019 reply->repeater_present = !!(raw->msg[1] & BIT(5)); 1020 reply->state = (raw->msg[1] & GENMASK(7, 6)) >> 6; 1021 1022 return true; 1023 } 1024 1025 static bool drm_dp_sideband_parse_reply(const struct drm_dp_mst_topology_mgr *mgr, 1026 struct drm_dp_sideband_msg_rx *raw, 1027 struct drm_dp_sideband_msg_reply_body *msg) 1028 { 1029 memset(msg, 0, sizeof(*msg)); 1030 msg->reply_type = (raw->msg[0] & 0x80) >> 7; 1031 msg->req_type = (raw->msg[0] & 0x7f); 1032 1033 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) { 1034 memcpy(msg->u.nak.guid, &raw->msg[1], 16); 1035 msg->u.nak.reason = raw->msg[17]; 1036 msg->u.nak.nak_data = raw->msg[18]; 1037 return false; 1038 } 1039 1040 switch (msg->req_type) { 1041 case DP_LINK_ADDRESS: 1042 return drm_dp_sideband_parse_link_address(mgr, raw, msg); 1043 case DP_QUERY_PAYLOAD: 1044 return drm_dp_sideband_parse_query_payload_ack(raw, msg); 1045 case DP_REMOTE_DPCD_READ: 1046 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg); 1047 case DP_REMOTE_DPCD_WRITE: 1048 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg); 1049 case DP_REMOTE_I2C_READ: 1050 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg); 1051 case DP_REMOTE_I2C_WRITE: 1052 return true; /* since there's nothing to parse */ 1053 case DP_ENUM_PATH_RESOURCES: 1054 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg); 1055 case DP_ALLOCATE_PAYLOAD: 1056 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg); 1057 case DP_POWER_DOWN_PHY: 1058 case DP_POWER_UP_PHY: 1059 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg); 1060 case DP_CLEAR_PAYLOAD_ID_TABLE: 1061 return true; /* since there's nothing to parse */ 1062 case DP_QUERY_STREAM_ENC_STATUS: 1063 return drm_dp_sideband_parse_query_stream_enc_status(raw, msg); 1064 default: 1065 drm_err(mgr->dev, "Got unknown reply 0x%02x (%s)\n", 1066 msg->req_type, drm_dp_mst_req_type_str(msg->req_type)); 1067 return false; 1068 } 1069 } 1070 1071 static bool 1072 drm_dp_sideband_parse_connection_status_notify(const struct drm_dp_mst_topology_mgr *mgr, 1073 struct drm_dp_sideband_msg_rx *raw, 1074 struct drm_dp_sideband_msg_req_body *msg) 1075 { 1076 int idx = 1; 1077 1078 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; 1079 idx++; 1080 if (idx > raw->curlen) 1081 goto fail_len; 1082 1083 memcpy(msg->u.conn_stat.guid, &raw->msg[idx], 16); 1084 idx += 16; 1085 if (idx > raw->curlen) 1086 goto fail_len; 1087 1088 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1; 1089 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1; 1090 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1; 1091 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1; 1092 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7); 1093 idx++; 1094 return true; 1095 fail_len: 1096 drm_dbg_kms(mgr->dev, "connection status reply parse length fail %d %d\n", 1097 idx, raw->curlen); 1098 return false; 1099 } 1100 1101 static bool drm_dp_sideband_parse_resource_status_notify(const struct drm_dp_mst_topology_mgr *mgr, 1102 struct drm_dp_sideband_msg_rx *raw, 1103 struct drm_dp_sideband_msg_req_body *msg) 1104 { 1105 int idx = 1; 1106 1107 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; 1108 idx++; 1109 if (idx > raw->curlen) 1110 goto fail_len; 1111 1112 memcpy(msg->u.resource_stat.guid, &raw->msg[idx], 16); 1113 idx += 16; 1114 if (idx > raw->curlen) 1115 goto fail_len; 1116 1117 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); 1118 idx++; 1119 return true; 1120 fail_len: 1121 drm_dbg_kms(mgr->dev, "resource status reply parse length fail %d %d\n", idx, raw->curlen); 1122 return false; 1123 } 1124 1125 static bool drm_dp_sideband_parse_req(const struct drm_dp_mst_topology_mgr *mgr, 1126 struct drm_dp_sideband_msg_rx *raw, 1127 struct drm_dp_sideband_msg_req_body *msg) 1128 { 1129 memset(msg, 0, sizeof(*msg)); 1130 msg->req_type = (raw->msg[0] & 0x7f); 1131 1132 switch (msg->req_type) { 1133 case DP_CONNECTION_STATUS_NOTIFY: 1134 return drm_dp_sideband_parse_connection_status_notify(mgr, raw, msg); 1135 case DP_RESOURCE_STATUS_NOTIFY: 1136 return drm_dp_sideband_parse_resource_status_notify(mgr, raw, msg); 1137 default: 1138 drm_err(mgr->dev, "Got unknown request 0x%02x (%s)\n", 1139 msg->req_type, drm_dp_mst_req_type_str(msg->req_type)); 1140 return false; 1141 } 1142 } 1143 1144 static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, 1145 u8 port_num, u32 offset, u8 num_bytes, u8 *bytes) 1146 { 1147 struct drm_dp_sideband_msg_req_body req; 1148 1149 req.req_type = DP_REMOTE_DPCD_WRITE; 1150 req.u.dpcd_write.port_number = port_num; 1151 req.u.dpcd_write.dpcd_address = offset; 1152 req.u.dpcd_write.num_bytes = num_bytes; 1153 req.u.dpcd_write.bytes = bytes; 1154 drm_dp_encode_sideband_req(&req, msg); 1155 } 1156 1157 static void build_link_address(struct drm_dp_sideband_msg_tx *msg) 1158 { 1159 struct drm_dp_sideband_msg_req_body req; 1160 1161 req.req_type = DP_LINK_ADDRESS; 1162 drm_dp_encode_sideband_req(&req, msg); 1163 } 1164 1165 static void build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg) 1166 { 1167 struct drm_dp_sideband_msg_req_body req; 1168 1169 req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE; 1170 drm_dp_encode_sideband_req(&req, msg); 1171 msg->path_msg = true; 1172 } 1173 1174 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, 1175 int port_num) 1176 { 1177 struct drm_dp_sideband_msg_req_body req; 1178 1179 req.req_type = DP_ENUM_PATH_RESOURCES; 1180 req.u.port_num.port_number = port_num; 1181 drm_dp_encode_sideband_req(&req, msg); 1182 msg->path_msg = true; 1183 return 0; 1184 } 1185 1186 static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, 1187 int port_num, 1188 u8 vcpi, uint16_t pbn, 1189 u8 number_sdp_streams, 1190 u8 *sdp_stream_sink) 1191 { 1192 struct drm_dp_sideband_msg_req_body req; 1193 1194 memset(&req, 0, sizeof(req)); 1195 req.req_type = DP_ALLOCATE_PAYLOAD; 1196 req.u.allocate_payload.port_number = port_num; 1197 req.u.allocate_payload.vcpi = vcpi; 1198 req.u.allocate_payload.pbn = pbn; 1199 req.u.allocate_payload.number_sdp_streams = number_sdp_streams; 1200 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink, 1201 number_sdp_streams); 1202 drm_dp_encode_sideband_req(&req, msg); 1203 msg->path_msg = true; 1204 } 1205 1206 static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg, 1207 int port_num, bool power_up) 1208 { 1209 struct drm_dp_sideband_msg_req_body req; 1210 1211 if (power_up) 1212 req.req_type = DP_POWER_UP_PHY; 1213 else 1214 req.req_type = DP_POWER_DOWN_PHY; 1215 1216 req.u.port_num.port_number = port_num; 1217 drm_dp_encode_sideband_req(&req, msg); 1218 msg->path_msg = true; 1219 } 1220 1221 static int 1222 build_query_stream_enc_status(struct drm_dp_sideband_msg_tx *msg, u8 stream_id, 1223 u8 *q_id) 1224 { 1225 struct drm_dp_sideband_msg_req_body req; 1226 1227 req.req_type = DP_QUERY_STREAM_ENC_STATUS; 1228 req.u.enc_status.stream_id = stream_id; 1229 memcpy(req.u.enc_status.client_id, q_id, 1230 sizeof(req.u.enc_status.client_id)); 1231 req.u.enc_status.stream_event = 0; 1232 req.u.enc_status.valid_stream_event = false; 1233 req.u.enc_status.stream_behavior = 0; 1234 req.u.enc_status.valid_stream_behavior = false; 1235 1236 drm_dp_encode_sideband_req(&req, msg); 1237 return 0; 1238 } 1239 1240 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr, 1241 struct drm_dp_sideband_msg_tx *txmsg) 1242 { 1243 unsigned int state; 1244 1245 /* 1246 * All updates to txmsg->state are protected by mgr->qlock, and the two 1247 * cases we check here are terminal states. For those the barriers 1248 * provided by the wake_up/wait_event pair are enough. 1249 */ 1250 state = READ_ONCE(txmsg->state); 1251 return (state == DRM_DP_SIDEBAND_TX_RX || 1252 state == DRM_DP_SIDEBAND_TX_TIMEOUT); 1253 } 1254 1255 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb, 1256 struct drm_dp_sideband_msg_tx *txmsg) 1257 { 1258 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 1259 unsigned long wait_timeout = msecs_to_jiffies(4000); 1260 unsigned long wait_expires = jiffies + wait_timeout; 1261 int ret; 1262 1263 for (;;) { 1264 /* 1265 * If the driver provides a way for this, change to 1266 * poll-waiting for the MST reply interrupt if we didn't receive 1267 * it for 50 msec. This would cater for cases where the HPD 1268 * pulse signal got lost somewhere, even though the sink raised 1269 * the corresponding MST interrupt correctly. One example is the 1270 * Club 3D CAC-1557 TypeC -> DP adapter which for some reason 1271 * filters out short pulses with a duration less than ~540 usec. 1272 * 1273 * The poll period is 50 msec to avoid missing an interrupt 1274 * after the sink has cleared it (after a 110msec timeout 1275 * since it raised the interrupt). 1276 */ 1277 ret = wait_event_timeout(mgr->tx_waitq, 1278 check_txmsg_state(mgr, txmsg), 1279 mgr->cbs->poll_hpd_irq ? 1280 msecs_to_jiffies(50) : 1281 wait_timeout); 1282 1283 if (ret || !mgr->cbs->poll_hpd_irq || 1284 time_after(jiffies, wait_expires)) 1285 break; 1286 1287 mgr->cbs->poll_hpd_irq(mgr); 1288 } 1289 1290 mutex_lock(&mgr->qlock); 1291 if (ret > 0) { 1292 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) { 1293 ret = -EIO; 1294 goto out; 1295 } 1296 } else { 1297 drm_dbg_kms(mgr->dev, "timedout msg send %p %d %d\n", 1298 txmsg, txmsg->state, txmsg->seqno); 1299 1300 /* dump some state */ 1301 ret = -EIO; 1302 1303 /* remove from q */ 1304 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED || 1305 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND || 1306 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) 1307 list_del(&txmsg->next); 1308 } 1309 out: 1310 if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) { 1311 struct drm_printer p = drm_debug_printer(DBG_PREFIX); 1312 1313 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 1314 } 1315 mutex_unlock(&mgr->qlock); 1316 1317 drm_dp_mst_kick_tx(mgr); 1318 return ret; 1319 } 1320 1321 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad) 1322 { 1323 struct drm_dp_mst_branch *mstb; 1324 1325 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL); 1326 if (!mstb) 1327 return NULL; 1328 1329 mstb->lct = lct; 1330 if (lct > 1) 1331 memcpy(mstb->rad, rad, lct / 2); 1332 INIT_LIST_HEAD(&mstb->ports); 1333 kref_init(&mstb->topology_kref); 1334 kref_init(&mstb->malloc_kref); 1335 return mstb; 1336 } 1337 1338 static void drm_dp_free_mst_branch_device(struct kref *kref) 1339 { 1340 struct drm_dp_mst_branch *mstb = 1341 container_of(kref, struct drm_dp_mst_branch, malloc_kref); 1342 1343 if (mstb->port_parent) 1344 drm_dp_mst_put_port_malloc(mstb->port_parent); 1345 1346 kfree(mstb); 1347 } 1348 1349 /** 1350 * DOC: Branch device and port refcounting 1351 * 1352 * Topology refcount overview 1353 * ~~~~~~~~~~~~~~~~~~~~~~~~~~ 1354 * 1355 * The refcounting schemes for &struct drm_dp_mst_branch and &struct 1356 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have 1357 * two different kinds of refcounts: topology refcounts, and malloc refcounts. 1358 * 1359 * Topology refcounts are not exposed to drivers, and are handled internally 1360 * by the DP MST helpers. The helpers use them in order to prevent the 1361 * in-memory topology state from being changed in the middle of critical 1362 * operations like changing the internal state of payload allocations. This 1363 * means each branch and port will be considered to be connected to the rest 1364 * of the topology until its topology refcount reaches zero. Additionally, 1365 * for ports this means that their associated &struct drm_connector will stay 1366 * registered with userspace until the port's refcount reaches 0. 1367 * 1368 * Malloc refcount overview 1369 * ~~~~~~~~~~~~~~~~~~~~~~~~ 1370 * 1371 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct 1372 * drm_dp_mst_branch allocated even after all of its topology references have 1373 * been dropped, so that the driver or MST helpers can safely access each 1374 * branch's last known state before it was disconnected from the topology. 1375 * When the malloc refcount of a port or branch reaches 0, the memory 1376 * allocation containing the &struct drm_dp_mst_branch or &struct 1377 * drm_dp_mst_port respectively will be freed. 1378 * 1379 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed 1380 * to drivers. As of writing this documentation, there are no drivers that 1381 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST 1382 * helpers. Exposing this API to drivers in a race-free manner would take more 1383 * tweaking of the refcounting scheme, however patches are welcome provided 1384 * there is a legitimate driver usecase for this. 1385 * 1386 * Refcount relationships in a topology 1387 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1388 * 1389 * Let's take a look at why the relationship between topology and malloc 1390 * refcounts is designed the way it is. 1391 * 1392 * .. kernel-figure:: dp-mst/topology-figure-1.dot 1393 * 1394 * An example of topology and malloc refs in a DP MST topology with two 1395 * active payloads. Topology refcount increments are indicated by solid 1396 * lines, and malloc refcount increments are indicated by dashed lines. 1397 * Each starts from the branch which incremented the refcount, and ends at 1398 * the branch to which the refcount belongs to, i.e. the arrow points the 1399 * same way as the C pointers used to reference a structure. 1400 * 1401 * As you can see in the above figure, every branch increments the topology 1402 * refcount of its children, and increments the malloc refcount of its 1403 * parent. Additionally, every payload increments the malloc refcount of its 1404 * assigned port by 1. 1405 * 1406 * So, what would happen if MSTB #3 from the above figure was unplugged from 1407 * the system, but the driver hadn't yet removed payload #2 from port #3? The 1408 * topology would start to look like the figure below. 1409 * 1410 * .. kernel-figure:: dp-mst/topology-figure-2.dot 1411 * 1412 * Ports and branch devices which have been released from memory are 1413 * colored grey, and references which have been removed are colored red. 1414 * 1415 * Whenever a port or branch device's topology refcount reaches zero, it will 1416 * decrement the topology refcounts of all its children, the malloc refcount 1417 * of its parent, and finally its own malloc refcount. For MSTB #4 and port 1418 * #4, this means they both have been disconnected from the topology and freed 1419 * from memory. But, because payload #2 is still holding a reference to port 1420 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port 1421 * is still accessible from memory. This also means port #3 has not yet 1422 * decremented the malloc refcount of MSTB #3, so its &struct 1423 * drm_dp_mst_branch will also stay allocated in memory until port #3's 1424 * malloc refcount reaches 0. 1425 * 1426 * This relationship is necessary because in order to release payload #2, we 1427 * need to be able to figure out the last relative of port #3 that's still 1428 * connected to the topology. In this case, we would travel up the topology as 1429 * shown below. 1430 * 1431 * .. kernel-figure:: dp-mst/topology-figure-3.dot 1432 * 1433 * And finally, remove payload #2 by communicating with port #2 through 1434 * sideband transactions. 1435 */ 1436 1437 /** 1438 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch 1439 * device 1440 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of 1441 * 1442 * Increments &drm_dp_mst_branch.malloc_kref. When 1443 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb 1444 * will be released and @mstb may no longer be used. 1445 * 1446 * See also: drm_dp_mst_put_mstb_malloc() 1447 */ 1448 static void 1449 drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb) 1450 { 1451 kref_get(&mstb->malloc_kref); 1452 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref)); 1453 } 1454 1455 /** 1456 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch 1457 * device 1458 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of 1459 * 1460 * Decrements &drm_dp_mst_branch.malloc_kref. When 1461 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb 1462 * will be released and @mstb may no longer be used. 1463 * 1464 * See also: drm_dp_mst_get_mstb_malloc() 1465 */ 1466 static void 1467 drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb) 1468 { 1469 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1); 1470 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device); 1471 } 1472 1473 static void drm_dp_free_mst_port(struct kref *kref) 1474 { 1475 struct drm_dp_mst_port *port = 1476 container_of(kref, struct drm_dp_mst_port, malloc_kref); 1477 1478 drm_dp_mst_put_mstb_malloc(port->parent); 1479 kfree(port); 1480 } 1481 1482 /** 1483 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port 1484 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of 1485 * 1486 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref 1487 * reaches 0, the memory allocation for @port will be released and @port may 1488 * no longer be used. 1489 * 1490 * Because @port could potentially be freed at any time by the DP MST helpers 1491 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this 1492 * function, drivers that which to make use of &struct drm_dp_mst_port should 1493 * ensure that they grab at least one main malloc reference to their MST ports 1494 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before 1495 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0. 1496 * 1497 * See also: drm_dp_mst_put_port_malloc() 1498 */ 1499 void 1500 drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port) 1501 { 1502 kref_get(&port->malloc_kref); 1503 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref)); 1504 } 1505 EXPORT_SYMBOL(drm_dp_mst_get_port_malloc); 1506 1507 /** 1508 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port 1509 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of 1510 * 1511 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref 1512 * reaches 0, the memory allocation for @port will be released and @port may 1513 * no longer be used. 1514 * 1515 * See also: drm_dp_mst_get_port_malloc() 1516 */ 1517 void 1518 drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port) 1519 { 1520 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1); 1521 kref_put(&port->malloc_kref, drm_dp_free_mst_port); 1522 } 1523 EXPORT_SYMBOL(drm_dp_mst_put_port_malloc); 1524 1525 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 1526 1527 #define STACK_DEPTH 8 1528 1529 static noinline void 1530 __topology_ref_save(struct drm_dp_mst_topology_mgr *mgr, 1531 struct drm_dp_mst_topology_ref_history *history, 1532 enum drm_dp_mst_topology_ref_type type) 1533 { 1534 struct drm_dp_mst_topology_ref_entry *entry = NULL; 1535 depot_stack_handle_t backtrace; 1536 ulong stack_entries[STACK_DEPTH]; 1537 uint n; 1538 int i; 1539 1540 n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1); 1541 backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL); 1542 if (!backtrace) 1543 return; 1544 1545 /* Try to find an existing entry for this backtrace */ 1546 for (i = 0; i < history->len; i++) { 1547 if (history->entries[i].backtrace == backtrace) { 1548 entry = &history->entries[i]; 1549 break; 1550 } 1551 } 1552 1553 /* Otherwise add one */ 1554 if (!entry) { 1555 struct drm_dp_mst_topology_ref_entry *new; 1556 int new_len = history->len + 1; 1557 1558 new = krealloc(history->entries, sizeof(*new) * new_len, 1559 GFP_KERNEL); 1560 if (!new) 1561 return; 1562 1563 entry = &new[history->len]; 1564 history->len = new_len; 1565 history->entries = new; 1566 1567 entry->backtrace = backtrace; 1568 entry->type = type; 1569 entry->count = 0; 1570 } 1571 entry->count++; 1572 entry->ts_nsec = ktime_get_ns(); 1573 } 1574 1575 static int 1576 topology_ref_history_cmp(const void *a, const void *b) 1577 { 1578 const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b; 1579 1580 if (entry_a->ts_nsec > entry_b->ts_nsec) 1581 return 1; 1582 else if (entry_a->ts_nsec < entry_b->ts_nsec) 1583 return -1; 1584 else 1585 return 0; 1586 } 1587 1588 static inline const char * 1589 topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type) 1590 { 1591 if (type == DRM_DP_MST_TOPOLOGY_REF_GET) 1592 return "get"; 1593 else 1594 return "put"; 1595 } 1596 1597 static void 1598 __dump_topology_ref_history(struct drm_dp_mst_topology_ref_history *history, 1599 void *ptr, const char *type_str) 1600 { 1601 struct drm_printer p = drm_debug_printer(DBG_PREFIX); 1602 char *buf = kzalloc(PAGE_SIZE, GFP_KERNEL); 1603 int i; 1604 1605 if (!buf) 1606 return; 1607 1608 if (!history->len) 1609 goto out; 1610 1611 /* First, sort the list so that it goes from oldest to newest 1612 * reference entry 1613 */ 1614 sort(history->entries, history->len, sizeof(*history->entries), 1615 topology_ref_history_cmp, NULL); 1616 1617 drm_printf(&p, "%s (%p) topology count reached 0, dumping history:\n", 1618 type_str, ptr); 1619 1620 for (i = 0; i < history->len; i++) { 1621 const struct drm_dp_mst_topology_ref_entry *entry = 1622 &history->entries[i]; 1623 u64 ts_nsec = entry->ts_nsec; 1624 u32 rem_nsec = do_div(ts_nsec, 1000000000); 1625 1626 stack_depot_snprint(entry->backtrace, buf, PAGE_SIZE, 4); 1627 1628 drm_printf(&p, " %d %ss (last at %5llu.%06u):\n%s", 1629 entry->count, 1630 topology_ref_type_to_str(entry->type), 1631 ts_nsec, rem_nsec / 1000, buf); 1632 } 1633 1634 /* Now free the history, since this is the only time we expose it */ 1635 kfree(history->entries); 1636 out: 1637 kfree(buf); 1638 } 1639 1640 static __always_inline void 1641 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) 1642 { 1643 __dump_topology_ref_history(&mstb->topology_ref_history, mstb, 1644 "MSTB"); 1645 } 1646 1647 static __always_inline void 1648 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) 1649 { 1650 __dump_topology_ref_history(&port->topology_ref_history, port, 1651 "Port"); 1652 } 1653 1654 static __always_inline void 1655 save_mstb_topology_ref(struct drm_dp_mst_branch *mstb, 1656 enum drm_dp_mst_topology_ref_type type) 1657 { 1658 __topology_ref_save(mstb->mgr, &mstb->topology_ref_history, type); 1659 } 1660 1661 static __always_inline void 1662 save_port_topology_ref(struct drm_dp_mst_port *port, 1663 enum drm_dp_mst_topology_ref_type type) 1664 { 1665 __topology_ref_save(port->mgr, &port->topology_ref_history, type); 1666 } 1667 1668 static inline void 1669 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) 1670 { 1671 mutex_lock(&mgr->topology_ref_history_lock); 1672 } 1673 1674 static inline void 1675 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) 1676 { 1677 mutex_unlock(&mgr->topology_ref_history_lock); 1678 } 1679 #else 1680 static inline void 1681 topology_ref_history_lock(struct drm_dp_mst_topology_mgr *mgr) {} 1682 static inline void 1683 topology_ref_history_unlock(struct drm_dp_mst_topology_mgr *mgr) {} 1684 static inline void 1685 drm_dp_mst_dump_mstb_topology_history(struct drm_dp_mst_branch *mstb) {} 1686 static inline void 1687 drm_dp_mst_dump_port_topology_history(struct drm_dp_mst_port *port) {} 1688 #define save_mstb_topology_ref(mstb, type) 1689 #define save_port_topology_ref(port, type) 1690 #endif 1691 1692 struct drm_dp_mst_atomic_payload * 1693 drm_atomic_get_mst_payload_state(struct drm_dp_mst_topology_state *state, 1694 struct drm_dp_mst_port *port) 1695 { 1696 struct drm_dp_mst_atomic_payload *payload; 1697 1698 list_for_each_entry(payload, &state->payloads, next) 1699 if (payload->port == port) 1700 return payload; 1701 1702 return NULL; 1703 } 1704 EXPORT_SYMBOL(drm_atomic_get_mst_payload_state); 1705 1706 static void drm_dp_destroy_mst_branch_device(struct kref *kref) 1707 { 1708 struct drm_dp_mst_branch *mstb = 1709 container_of(kref, struct drm_dp_mst_branch, topology_kref); 1710 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 1711 1712 drm_dp_mst_dump_mstb_topology_history(mstb); 1713 1714 INIT_LIST_HEAD(&mstb->destroy_next); 1715 1716 /* 1717 * This can get called under mgr->mutex, so we need to perform the 1718 * actual destruction of the mstb in another worker 1719 */ 1720 mutex_lock(&mgr->delayed_destroy_lock); 1721 list_add(&mstb->destroy_next, &mgr->destroy_branch_device_list); 1722 mutex_unlock(&mgr->delayed_destroy_lock); 1723 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work); 1724 } 1725 1726 /** 1727 * drm_dp_mst_topology_try_get_mstb() - Increment the topology refcount of a 1728 * branch device unless it's zero 1729 * @mstb: &struct drm_dp_mst_branch to increment the topology refcount of 1730 * 1731 * Attempts to grab a topology reference to @mstb, if it hasn't yet been 1732 * removed from the topology (e.g. &drm_dp_mst_branch.topology_kref has 1733 * reached 0). Holding a topology reference implies that a malloc reference 1734 * will be held to @mstb as long as the user holds the topology reference. 1735 * 1736 * Care should be taken to ensure that the user has at least one malloc 1737 * reference to @mstb. If you already have a topology reference to @mstb, you 1738 * should use drm_dp_mst_topology_get_mstb() instead. 1739 * 1740 * See also: 1741 * drm_dp_mst_topology_get_mstb() 1742 * drm_dp_mst_topology_put_mstb() 1743 * 1744 * Returns: 1745 * * 1: A topology reference was grabbed successfully 1746 * * 0: @port is no longer in the topology, no reference was grabbed 1747 */ 1748 static int __must_check 1749 drm_dp_mst_topology_try_get_mstb(struct drm_dp_mst_branch *mstb) 1750 { 1751 int ret; 1752 1753 topology_ref_history_lock(mstb->mgr); 1754 ret = kref_get_unless_zero(&mstb->topology_kref); 1755 if (ret) { 1756 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref)); 1757 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET); 1758 } 1759 1760 topology_ref_history_unlock(mstb->mgr); 1761 1762 return ret; 1763 } 1764 1765 /** 1766 * drm_dp_mst_topology_get_mstb() - Increment the topology refcount of a 1767 * branch device 1768 * @mstb: The &struct drm_dp_mst_branch to increment the topology refcount of 1769 * 1770 * Increments &drm_dp_mst_branch.topology_refcount without checking whether or 1771 * not it's already reached 0. This is only valid to use in scenarios where 1772 * you are already guaranteed to have at least one active topology reference 1773 * to @mstb. Otherwise, drm_dp_mst_topology_try_get_mstb() must be used. 1774 * 1775 * See also: 1776 * drm_dp_mst_topology_try_get_mstb() 1777 * drm_dp_mst_topology_put_mstb() 1778 */ 1779 static void drm_dp_mst_topology_get_mstb(struct drm_dp_mst_branch *mstb) 1780 { 1781 topology_ref_history_lock(mstb->mgr); 1782 1783 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_GET); 1784 WARN_ON(kref_read(&mstb->topology_kref) == 0); 1785 kref_get(&mstb->topology_kref); 1786 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref)); 1787 1788 topology_ref_history_unlock(mstb->mgr); 1789 } 1790 1791 /** 1792 * drm_dp_mst_topology_put_mstb() - release a topology reference to a branch 1793 * device 1794 * @mstb: The &struct drm_dp_mst_branch to release the topology reference from 1795 * 1796 * Releases a topology reference from @mstb by decrementing 1797 * &drm_dp_mst_branch.topology_kref. 1798 * 1799 * See also: 1800 * drm_dp_mst_topology_try_get_mstb() 1801 * drm_dp_mst_topology_get_mstb() 1802 */ 1803 static void 1804 drm_dp_mst_topology_put_mstb(struct drm_dp_mst_branch *mstb) 1805 { 1806 topology_ref_history_lock(mstb->mgr); 1807 1808 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->topology_kref) - 1); 1809 save_mstb_topology_ref(mstb, DRM_DP_MST_TOPOLOGY_REF_PUT); 1810 1811 topology_ref_history_unlock(mstb->mgr); 1812 kref_put(&mstb->topology_kref, drm_dp_destroy_mst_branch_device); 1813 } 1814 1815 static void drm_dp_destroy_port(struct kref *kref) 1816 { 1817 struct drm_dp_mst_port *port = 1818 container_of(kref, struct drm_dp_mst_port, topology_kref); 1819 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 1820 1821 drm_dp_mst_dump_port_topology_history(port); 1822 1823 /* There's nothing that needs locking to destroy an input port yet */ 1824 if (port->input) { 1825 drm_dp_mst_put_port_malloc(port); 1826 return; 1827 } 1828 1829 drm_edid_free(port->cached_edid); 1830 1831 /* 1832 * we can't destroy the connector here, as we might be holding the 1833 * mode_config.mutex from an EDID retrieval 1834 */ 1835 mutex_lock(&mgr->delayed_destroy_lock); 1836 list_add(&port->next, &mgr->destroy_port_list); 1837 mutex_unlock(&mgr->delayed_destroy_lock); 1838 queue_work(mgr->delayed_destroy_wq, &mgr->delayed_destroy_work); 1839 } 1840 1841 /** 1842 * drm_dp_mst_topology_try_get_port() - Increment the topology refcount of a 1843 * port unless it's zero 1844 * @port: &struct drm_dp_mst_port to increment the topology refcount of 1845 * 1846 * Attempts to grab a topology reference to @port, if it hasn't yet been 1847 * removed from the topology (e.g. &drm_dp_mst_port.topology_kref has reached 1848 * 0). Holding a topology reference implies that a malloc reference will be 1849 * held to @port as long as the user holds the topology reference. 1850 * 1851 * Care should be taken to ensure that the user has at least one malloc 1852 * reference to @port. If you already have a topology reference to @port, you 1853 * should use drm_dp_mst_topology_get_port() instead. 1854 * 1855 * See also: 1856 * drm_dp_mst_topology_get_port() 1857 * drm_dp_mst_topology_put_port() 1858 * 1859 * Returns: 1860 * * 1: A topology reference was grabbed successfully 1861 * * 0: @port is no longer in the topology, no reference was grabbed 1862 */ 1863 static int __must_check 1864 drm_dp_mst_topology_try_get_port(struct drm_dp_mst_port *port) 1865 { 1866 int ret; 1867 1868 topology_ref_history_lock(port->mgr); 1869 ret = kref_get_unless_zero(&port->topology_kref); 1870 if (ret) { 1871 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref)); 1872 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET); 1873 } 1874 1875 topology_ref_history_unlock(port->mgr); 1876 return ret; 1877 } 1878 1879 /** 1880 * drm_dp_mst_topology_get_port() - Increment the topology refcount of a port 1881 * @port: The &struct drm_dp_mst_port to increment the topology refcount of 1882 * 1883 * Increments &drm_dp_mst_port.topology_refcount without checking whether or 1884 * not it's already reached 0. This is only valid to use in scenarios where 1885 * you are already guaranteed to have at least one active topology reference 1886 * to @port. Otherwise, drm_dp_mst_topology_try_get_port() must be used. 1887 * 1888 * See also: 1889 * drm_dp_mst_topology_try_get_port() 1890 * drm_dp_mst_topology_put_port() 1891 */ 1892 static void drm_dp_mst_topology_get_port(struct drm_dp_mst_port *port) 1893 { 1894 topology_ref_history_lock(port->mgr); 1895 1896 WARN_ON(kref_read(&port->topology_kref) == 0); 1897 kref_get(&port->topology_kref); 1898 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref)); 1899 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_GET); 1900 1901 topology_ref_history_unlock(port->mgr); 1902 } 1903 1904 /** 1905 * drm_dp_mst_topology_put_port() - release a topology reference to a port 1906 * @port: The &struct drm_dp_mst_port to release the topology reference from 1907 * 1908 * Releases a topology reference from @port by decrementing 1909 * &drm_dp_mst_port.topology_kref. 1910 * 1911 * See also: 1912 * drm_dp_mst_topology_try_get_port() 1913 * drm_dp_mst_topology_get_port() 1914 */ 1915 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port) 1916 { 1917 topology_ref_history_lock(port->mgr); 1918 1919 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->topology_kref) - 1); 1920 save_port_topology_ref(port, DRM_DP_MST_TOPOLOGY_REF_PUT); 1921 1922 topology_ref_history_unlock(port->mgr); 1923 kref_put(&port->topology_kref, drm_dp_destroy_port); 1924 } 1925 1926 static struct drm_dp_mst_branch * 1927 drm_dp_mst_topology_get_mstb_validated_locked(struct drm_dp_mst_branch *mstb, 1928 struct drm_dp_mst_branch *to_find) 1929 { 1930 struct drm_dp_mst_port *port; 1931 struct drm_dp_mst_branch *rmstb; 1932 1933 if (to_find == mstb) 1934 return mstb; 1935 1936 list_for_each_entry(port, &mstb->ports, next) { 1937 if (port->mstb) { 1938 rmstb = drm_dp_mst_topology_get_mstb_validated_locked( 1939 port->mstb, to_find); 1940 if (rmstb) 1941 return rmstb; 1942 } 1943 } 1944 return NULL; 1945 } 1946 1947 static struct drm_dp_mst_branch * 1948 drm_dp_mst_topology_get_mstb_validated(struct drm_dp_mst_topology_mgr *mgr, 1949 struct drm_dp_mst_branch *mstb) 1950 { 1951 struct drm_dp_mst_branch *rmstb = NULL; 1952 1953 mutex_lock(&mgr->lock); 1954 if (mgr->mst_primary) { 1955 rmstb = drm_dp_mst_topology_get_mstb_validated_locked( 1956 mgr->mst_primary, mstb); 1957 1958 if (rmstb && !drm_dp_mst_topology_try_get_mstb(rmstb)) 1959 rmstb = NULL; 1960 } 1961 mutex_unlock(&mgr->lock); 1962 return rmstb; 1963 } 1964 1965 static struct drm_dp_mst_port * 1966 drm_dp_mst_topology_get_port_validated_locked(struct drm_dp_mst_branch *mstb, 1967 struct drm_dp_mst_port *to_find) 1968 { 1969 struct drm_dp_mst_port *port, *mport; 1970 1971 list_for_each_entry(port, &mstb->ports, next) { 1972 if (port == to_find) 1973 return port; 1974 1975 if (port->mstb) { 1976 mport = drm_dp_mst_topology_get_port_validated_locked( 1977 port->mstb, to_find); 1978 if (mport) 1979 return mport; 1980 } 1981 } 1982 return NULL; 1983 } 1984 1985 static struct drm_dp_mst_port * 1986 drm_dp_mst_topology_get_port_validated(struct drm_dp_mst_topology_mgr *mgr, 1987 struct drm_dp_mst_port *port) 1988 { 1989 struct drm_dp_mst_port *rport = NULL; 1990 1991 mutex_lock(&mgr->lock); 1992 if (mgr->mst_primary) { 1993 rport = drm_dp_mst_topology_get_port_validated_locked( 1994 mgr->mst_primary, port); 1995 1996 if (rport && !drm_dp_mst_topology_try_get_port(rport)) 1997 rport = NULL; 1998 } 1999 mutex_unlock(&mgr->lock); 2000 return rport; 2001 } 2002 2003 static struct drm_dp_mst_port *drm_dp_get_port(struct drm_dp_mst_branch *mstb, u8 port_num) 2004 { 2005 struct drm_dp_mst_port *port; 2006 int ret; 2007 2008 list_for_each_entry(port, &mstb->ports, next) { 2009 if (port->port_num == port_num) { 2010 ret = drm_dp_mst_topology_try_get_port(port); 2011 return ret ? port : NULL; 2012 } 2013 } 2014 2015 return NULL; 2016 } 2017 2018 /* 2019 * calculate a new RAD for this MST branch device 2020 * if parent has an LCT of 2 then it has 1 nibble of RAD, 2021 * if parent has an LCT of 3 then it has 2 nibbles of RAD, 2022 */ 2023 static u8 drm_dp_calculate_rad(struct drm_dp_mst_port *port, 2024 u8 *rad) 2025 { 2026 int parent_lct = port->parent->lct; 2027 int shift = 4; 2028 int idx = (parent_lct - 1) / 2; 2029 2030 if (parent_lct > 1) { 2031 memcpy(rad, port->parent->rad, idx + 1); 2032 shift = (parent_lct % 2) ? 4 : 0; 2033 } else 2034 rad[0] = 0; 2035 2036 rad[idx] |= port->port_num << shift; 2037 return parent_lct + 1; 2038 } 2039 2040 static bool drm_dp_mst_is_end_device(u8 pdt, bool mcs) 2041 { 2042 switch (pdt) { 2043 case DP_PEER_DEVICE_DP_LEGACY_CONV: 2044 case DP_PEER_DEVICE_SST_SINK: 2045 return true; 2046 case DP_PEER_DEVICE_MST_BRANCHING: 2047 /* For sst branch device */ 2048 if (!mcs) 2049 return true; 2050 2051 return false; 2052 } 2053 return true; 2054 } 2055 2056 static int 2057 drm_dp_port_set_pdt(struct drm_dp_mst_port *port, u8 new_pdt, 2058 bool new_mcs) 2059 { 2060 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 2061 struct drm_dp_mst_branch *mstb; 2062 u8 rad[8], lct; 2063 int ret = 0; 2064 2065 if (port->pdt == new_pdt && port->mcs == new_mcs) 2066 return 0; 2067 2068 /* Teardown the old pdt, if there is one */ 2069 if (port->pdt != DP_PEER_DEVICE_NONE) { 2070 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { 2071 /* 2072 * If the new PDT would also have an i2c bus, 2073 * don't bother with reregistering it 2074 */ 2075 if (new_pdt != DP_PEER_DEVICE_NONE && 2076 drm_dp_mst_is_end_device(new_pdt, new_mcs)) { 2077 port->pdt = new_pdt; 2078 port->mcs = new_mcs; 2079 return 0; 2080 } 2081 2082 /* remove i2c over sideband */ 2083 drm_dp_mst_unregister_i2c_bus(port); 2084 } else { 2085 mutex_lock(&mgr->lock); 2086 drm_dp_mst_topology_put_mstb(port->mstb); 2087 port->mstb = NULL; 2088 mutex_unlock(&mgr->lock); 2089 } 2090 } 2091 2092 port->pdt = new_pdt; 2093 port->mcs = new_mcs; 2094 2095 if (port->pdt != DP_PEER_DEVICE_NONE) { 2096 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { 2097 /* add i2c over sideband */ 2098 ret = drm_dp_mst_register_i2c_bus(port); 2099 } else { 2100 lct = drm_dp_calculate_rad(port, rad); 2101 mstb = drm_dp_add_mst_branch_device(lct, rad); 2102 if (!mstb) { 2103 ret = -ENOMEM; 2104 drm_err(mgr->dev, "Failed to create MSTB for port %p", port); 2105 goto out; 2106 } 2107 2108 mutex_lock(&mgr->lock); 2109 port->mstb = mstb; 2110 mstb->mgr = port->mgr; 2111 mstb->port_parent = port; 2112 2113 /* 2114 * Make sure this port's memory allocation stays 2115 * around until its child MSTB releases it 2116 */ 2117 drm_dp_mst_get_port_malloc(port); 2118 mutex_unlock(&mgr->lock); 2119 2120 /* And make sure we send a link address for this */ 2121 ret = 1; 2122 } 2123 } 2124 2125 out: 2126 if (ret < 0) 2127 port->pdt = DP_PEER_DEVICE_NONE; 2128 return ret; 2129 } 2130 2131 /** 2132 * drm_dp_mst_dpcd_read() - read a series of bytes from the DPCD via sideband 2133 * @aux: Fake sideband AUX CH 2134 * @offset: address of the (first) register to read 2135 * @buffer: buffer to store the register values 2136 * @size: number of bytes in @buffer 2137 * 2138 * Performs the same functionality for remote devices via 2139 * sideband messaging as drm_dp_dpcd_read() does for local 2140 * devices via actual AUX CH. 2141 * 2142 * Return: Number of bytes read, or negative error code on failure. 2143 */ 2144 ssize_t drm_dp_mst_dpcd_read(struct drm_dp_aux *aux, 2145 unsigned int offset, void *buffer, size_t size) 2146 { 2147 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, 2148 aux); 2149 2150 return drm_dp_send_dpcd_read(port->mgr, port, 2151 offset, size, buffer); 2152 } 2153 2154 /** 2155 * drm_dp_mst_dpcd_write() - write a series of bytes to the DPCD via sideband 2156 * @aux: Fake sideband AUX CH 2157 * @offset: address of the (first) register to write 2158 * @buffer: buffer containing the values to write 2159 * @size: number of bytes in @buffer 2160 * 2161 * Performs the same functionality for remote devices via 2162 * sideband messaging as drm_dp_dpcd_write() does for local 2163 * devices via actual AUX CH. 2164 * 2165 * Return: number of bytes written on success, negative error code on failure. 2166 */ 2167 ssize_t drm_dp_mst_dpcd_write(struct drm_dp_aux *aux, 2168 unsigned int offset, void *buffer, size_t size) 2169 { 2170 struct drm_dp_mst_port *port = container_of(aux, struct drm_dp_mst_port, 2171 aux); 2172 2173 return drm_dp_send_dpcd_write(port->mgr, port, 2174 offset, size, buffer); 2175 } 2176 2177 static int drm_dp_check_mstb_guid(struct drm_dp_mst_branch *mstb, u8 *guid) 2178 { 2179 int ret = 0; 2180 2181 memcpy(mstb->guid, guid, 16); 2182 2183 if (!drm_dp_validate_guid(mstb->mgr, mstb->guid)) { 2184 if (mstb->port_parent) { 2185 ret = drm_dp_send_dpcd_write(mstb->mgr, 2186 mstb->port_parent, 2187 DP_GUID, 16, mstb->guid); 2188 } else { 2189 ret = drm_dp_dpcd_write(mstb->mgr->aux, 2190 DP_GUID, mstb->guid, 16); 2191 } 2192 } 2193 2194 if (ret < 16 && ret > 0) 2195 return -EPROTO; 2196 2197 return ret == 16 ? 0 : ret; 2198 } 2199 2200 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb, 2201 int pnum, 2202 char *proppath, 2203 size_t proppath_size) 2204 { 2205 int i; 2206 char temp[8]; 2207 2208 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id); 2209 for (i = 0; i < (mstb->lct - 1); i++) { 2210 int shift = (i % 2) ? 0 : 4; 2211 int port_num = (mstb->rad[i / 2] >> shift) & 0xf; 2212 2213 snprintf(temp, sizeof(temp), "-%d", port_num); 2214 strlcat(proppath, temp, proppath_size); 2215 } 2216 snprintf(temp, sizeof(temp), "-%d", pnum); 2217 strlcat(proppath, temp, proppath_size); 2218 } 2219 2220 /** 2221 * drm_dp_mst_connector_late_register() - Late MST connector registration 2222 * @connector: The MST connector 2223 * @port: The MST port for this connector 2224 * 2225 * Helper to register the remote aux device for this MST port. Drivers should 2226 * call this from their mst connector's late_register hook to enable MST aux 2227 * devices. 2228 * 2229 * Return: 0 on success, negative error code on failure. 2230 */ 2231 int drm_dp_mst_connector_late_register(struct drm_connector *connector, 2232 struct drm_dp_mst_port *port) 2233 { 2234 drm_dbg_kms(port->mgr->dev, "registering %s remote bus for %s\n", 2235 port->aux.name, connector->kdev->kobj.name); 2236 2237 port->aux.dev = connector->kdev; 2238 return drm_dp_aux_register_devnode(&port->aux); 2239 } 2240 EXPORT_SYMBOL(drm_dp_mst_connector_late_register); 2241 2242 /** 2243 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration 2244 * @connector: The MST connector 2245 * @port: The MST port for this connector 2246 * 2247 * Helper to unregister the remote aux device for this MST port, registered by 2248 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst 2249 * connector's early_unregister hook. 2250 */ 2251 void drm_dp_mst_connector_early_unregister(struct drm_connector *connector, 2252 struct drm_dp_mst_port *port) 2253 { 2254 drm_dbg_kms(port->mgr->dev, "unregistering %s remote bus for %s\n", 2255 port->aux.name, connector->kdev->kobj.name); 2256 drm_dp_aux_unregister_devnode(&port->aux); 2257 } 2258 EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister); 2259 2260 static void 2261 drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb, 2262 struct drm_dp_mst_port *port) 2263 { 2264 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 2265 char proppath[255]; 2266 int ret; 2267 2268 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath)); 2269 port->connector = mgr->cbs->add_connector(mgr, port, proppath); 2270 if (!port->connector) { 2271 ret = -ENOMEM; 2272 goto error; 2273 } 2274 2275 if (port->pdt != DP_PEER_DEVICE_NONE && 2276 drm_dp_mst_is_end_device(port->pdt, port->mcs) && 2277 port->port_num >= DP_MST_LOGICAL_PORT_0) 2278 port->cached_edid = drm_edid_read_ddc(port->connector, 2279 &port->aux.ddc); 2280 2281 drm_connector_register(port->connector); 2282 return; 2283 2284 error: 2285 drm_err(mgr->dev, "Failed to create connector for port %p: %d\n", port, ret); 2286 } 2287 2288 /* 2289 * Drop a topology reference, and unlink the port from the in-memory topology 2290 * layout 2291 */ 2292 static void 2293 drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr, 2294 struct drm_dp_mst_port *port) 2295 { 2296 mutex_lock(&mgr->lock); 2297 port->parent->num_ports--; 2298 list_del(&port->next); 2299 mutex_unlock(&mgr->lock); 2300 drm_dp_mst_topology_put_port(port); 2301 } 2302 2303 static struct drm_dp_mst_port * 2304 drm_dp_mst_add_port(struct drm_device *dev, 2305 struct drm_dp_mst_topology_mgr *mgr, 2306 struct drm_dp_mst_branch *mstb, u8 port_number) 2307 { 2308 struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL); 2309 2310 if (!port) 2311 return NULL; 2312 2313 kref_init(&port->topology_kref); 2314 kref_init(&port->malloc_kref); 2315 port->parent = mstb; 2316 port->port_num = port_number; 2317 port->mgr = mgr; 2318 port->aux.name = "DPMST"; 2319 port->aux.dev = dev->dev; 2320 port->aux.is_remote = true; 2321 2322 /* initialize the MST downstream port's AUX crc work queue */ 2323 port->aux.drm_dev = dev; 2324 drm_dp_remote_aux_init(&port->aux); 2325 2326 /* 2327 * Make sure the memory allocation for our parent branch stays 2328 * around until our own memory allocation is released 2329 */ 2330 drm_dp_mst_get_mstb_malloc(mstb); 2331 2332 return port; 2333 } 2334 2335 static int 2336 drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb, 2337 struct drm_device *dev, 2338 struct drm_dp_link_addr_reply_port *port_msg) 2339 { 2340 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 2341 struct drm_dp_mst_port *port; 2342 int old_ddps = 0, ret; 2343 u8 new_pdt = DP_PEER_DEVICE_NONE; 2344 bool new_mcs = 0; 2345 bool created = false, send_link_addr = false, changed = false; 2346 2347 port = drm_dp_get_port(mstb, port_msg->port_number); 2348 if (!port) { 2349 port = drm_dp_mst_add_port(dev, mgr, mstb, 2350 port_msg->port_number); 2351 if (!port) 2352 return -ENOMEM; 2353 created = true; 2354 changed = true; 2355 } else if (!port->input && port_msg->input_port && port->connector) { 2356 /* Since port->connector can't be changed here, we create a 2357 * new port if input_port changes from 0 to 1 2358 */ 2359 drm_dp_mst_topology_unlink_port(mgr, port); 2360 drm_dp_mst_topology_put_port(port); 2361 port = drm_dp_mst_add_port(dev, mgr, mstb, 2362 port_msg->port_number); 2363 if (!port) 2364 return -ENOMEM; 2365 changed = true; 2366 created = true; 2367 } else if (port->input && !port_msg->input_port) { 2368 changed = true; 2369 } else if (port->connector) { 2370 /* We're updating a port that's exposed to userspace, so do it 2371 * under lock 2372 */ 2373 drm_modeset_lock(&mgr->base.lock, NULL); 2374 2375 old_ddps = port->ddps; 2376 changed = port->ddps != port_msg->ddps || 2377 (port->ddps && 2378 (port->ldps != port_msg->legacy_device_plug_status || 2379 port->dpcd_rev != port_msg->dpcd_revision || 2380 port->mcs != port_msg->mcs || 2381 port->pdt != port_msg->peer_device_type || 2382 port->num_sdp_stream_sinks != 2383 port_msg->num_sdp_stream_sinks)); 2384 } 2385 2386 port->input = port_msg->input_port; 2387 if (!port->input) 2388 new_pdt = port_msg->peer_device_type; 2389 new_mcs = port_msg->mcs; 2390 port->ddps = port_msg->ddps; 2391 port->ldps = port_msg->legacy_device_plug_status; 2392 port->dpcd_rev = port_msg->dpcd_revision; 2393 port->num_sdp_streams = port_msg->num_sdp_streams; 2394 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks; 2395 2396 /* manage mstb port lists with mgr lock - take a reference 2397 for this list */ 2398 if (created) { 2399 mutex_lock(&mgr->lock); 2400 drm_dp_mst_topology_get_port(port); 2401 list_add(&port->next, &mstb->ports); 2402 mstb->num_ports++; 2403 mutex_unlock(&mgr->lock); 2404 } 2405 2406 /* 2407 * Reprobe PBN caps on both hotplug, and when re-probing the link 2408 * for our parent mstb 2409 */ 2410 if (old_ddps != port->ddps || !created) { 2411 if (port->ddps && !port->input) { 2412 ret = drm_dp_send_enum_path_resources(mgr, mstb, 2413 port); 2414 if (ret == 1) 2415 changed = true; 2416 } else { 2417 port->full_pbn = 0; 2418 } 2419 } 2420 2421 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs); 2422 if (ret == 1) { 2423 send_link_addr = true; 2424 } else if (ret < 0) { 2425 drm_err(dev, "Failed to change PDT on port %p: %d\n", port, ret); 2426 goto fail; 2427 } 2428 2429 /* 2430 * If this port wasn't just created, then we're reprobing because 2431 * we're coming out of suspend. In this case, always resend the link 2432 * address if there's an MSTB on this port 2433 */ 2434 if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING && 2435 port->mcs) 2436 send_link_addr = true; 2437 2438 if (port->connector) 2439 drm_modeset_unlock(&mgr->base.lock); 2440 else if (!port->input) 2441 drm_dp_mst_port_add_connector(mstb, port); 2442 2443 if (send_link_addr && port->mstb) { 2444 ret = drm_dp_send_link_address(mgr, port->mstb); 2445 if (ret == 1) /* MSTB below us changed */ 2446 changed = true; 2447 else if (ret < 0) 2448 goto fail_put; 2449 } 2450 2451 /* put reference to this port */ 2452 drm_dp_mst_topology_put_port(port); 2453 return changed; 2454 2455 fail: 2456 drm_dp_mst_topology_unlink_port(mgr, port); 2457 if (port->connector) 2458 drm_modeset_unlock(&mgr->base.lock); 2459 fail_put: 2460 drm_dp_mst_topology_put_port(port); 2461 return ret; 2462 } 2463 2464 static int 2465 drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb, 2466 struct drm_dp_connection_status_notify *conn_stat) 2467 { 2468 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 2469 struct drm_dp_mst_port *port; 2470 int old_ddps, ret; 2471 u8 new_pdt; 2472 bool new_mcs; 2473 bool dowork = false, create_connector = false; 2474 2475 port = drm_dp_get_port(mstb, conn_stat->port_number); 2476 if (!port) 2477 return 0; 2478 2479 if (port->connector) { 2480 if (!port->input && conn_stat->input_port) { 2481 /* 2482 * We can't remove a connector from an already exposed 2483 * port, so just throw the port out and make sure we 2484 * reprobe the link address of it's parent MSTB 2485 */ 2486 drm_dp_mst_topology_unlink_port(mgr, port); 2487 mstb->link_address_sent = false; 2488 dowork = true; 2489 goto out; 2490 } 2491 2492 /* Locking is only needed if the port's exposed to userspace */ 2493 drm_modeset_lock(&mgr->base.lock, NULL); 2494 } else if (port->input && !conn_stat->input_port) { 2495 create_connector = true; 2496 /* Reprobe link address so we get num_sdp_streams */ 2497 mstb->link_address_sent = false; 2498 dowork = true; 2499 } 2500 2501 old_ddps = port->ddps; 2502 port->input = conn_stat->input_port; 2503 port->ldps = conn_stat->legacy_device_plug_status; 2504 port->ddps = conn_stat->displayport_device_plug_status; 2505 2506 if (old_ddps != port->ddps) { 2507 if (port->ddps && !port->input) 2508 drm_dp_send_enum_path_resources(mgr, mstb, port); 2509 else 2510 port->full_pbn = 0; 2511 } 2512 2513 new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type; 2514 new_mcs = conn_stat->message_capability_status; 2515 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs); 2516 if (ret == 1) { 2517 dowork = true; 2518 } else if (ret < 0) { 2519 drm_err(mgr->dev, "Failed to change PDT for port %p: %d\n", port, ret); 2520 dowork = false; 2521 } 2522 2523 if (port->connector) 2524 drm_modeset_unlock(&mgr->base.lock); 2525 else if (create_connector) 2526 drm_dp_mst_port_add_connector(mstb, port); 2527 2528 out: 2529 drm_dp_mst_topology_put_port(port); 2530 return dowork; 2531 } 2532 2533 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr, 2534 u8 lct, u8 *rad) 2535 { 2536 struct drm_dp_mst_branch *mstb; 2537 struct drm_dp_mst_port *port; 2538 int i, ret; 2539 /* find the port by iterating down */ 2540 2541 mutex_lock(&mgr->lock); 2542 mstb = mgr->mst_primary; 2543 2544 if (!mstb) 2545 goto out; 2546 2547 for (i = 0; i < lct - 1; i++) { 2548 int shift = (i % 2) ? 0 : 4; 2549 int port_num = (rad[i / 2] >> shift) & 0xf; 2550 2551 list_for_each_entry(port, &mstb->ports, next) { 2552 if (port->port_num == port_num) { 2553 mstb = port->mstb; 2554 if (!mstb) { 2555 drm_err(mgr->dev, 2556 "failed to lookup MSTB with lct %d, rad %02x\n", 2557 lct, rad[0]); 2558 goto out; 2559 } 2560 2561 break; 2562 } 2563 } 2564 } 2565 ret = drm_dp_mst_topology_try_get_mstb(mstb); 2566 if (!ret) 2567 mstb = NULL; 2568 out: 2569 mutex_unlock(&mgr->lock); 2570 return mstb; 2571 } 2572 2573 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper( 2574 struct drm_dp_mst_branch *mstb, 2575 const uint8_t *guid) 2576 { 2577 struct drm_dp_mst_branch *found_mstb; 2578 struct drm_dp_mst_port *port; 2579 2580 if (!mstb) 2581 return NULL; 2582 2583 if (memcmp(mstb->guid, guid, 16) == 0) 2584 return mstb; 2585 2586 2587 list_for_each_entry(port, &mstb->ports, next) { 2588 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid); 2589 2590 if (found_mstb) 2591 return found_mstb; 2592 } 2593 2594 return NULL; 2595 } 2596 2597 static struct drm_dp_mst_branch * 2598 drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr, 2599 const uint8_t *guid) 2600 { 2601 struct drm_dp_mst_branch *mstb; 2602 int ret; 2603 2604 /* find the port by iterating down */ 2605 mutex_lock(&mgr->lock); 2606 2607 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid); 2608 if (mstb) { 2609 ret = drm_dp_mst_topology_try_get_mstb(mstb); 2610 if (!ret) 2611 mstb = NULL; 2612 } 2613 2614 mutex_unlock(&mgr->lock); 2615 return mstb; 2616 } 2617 2618 static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 2619 struct drm_dp_mst_branch *mstb) 2620 { 2621 struct drm_dp_mst_port *port; 2622 int ret; 2623 bool changed = false; 2624 2625 if (!mstb->link_address_sent) { 2626 ret = drm_dp_send_link_address(mgr, mstb); 2627 if (ret == 1) 2628 changed = true; 2629 else if (ret < 0) 2630 return ret; 2631 } 2632 2633 list_for_each_entry(port, &mstb->ports, next) { 2634 if (port->input || !port->ddps || !port->mstb) 2635 continue; 2636 2637 ret = drm_dp_check_and_send_link_address(mgr, port->mstb); 2638 if (ret == 1) 2639 changed = true; 2640 else if (ret < 0) 2641 return ret; 2642 } 2643 2644 return changed; 2645 } 2646 2647 static void drm_dp_mst_link_probe_work(struct work_struct *work) 2648 { 2649 struct drm_dp_mst_topology_mgr *mgr = 2650 container_of(work, struct drm_dp_mst_topology_mgr, work); 2651 struct drm_device *dev = mgr->dev; 2652 struct drm_dp_mst_branch *mstb; 2653 int ret; 2654 bool clear_payload_id_table; 2655 2656 mutex_lock(&mgr->probe_lock); 2657 2658 mutex_lock(&mgr->lock); 2659 clear_payload_id_table = !mgr->payload_id_table_cleared; 2660 mgr->payload_id_table_cleared = true; 2661 2662 mstb = mgr->mst_primary; 2663 if (mstb) { 2664 ret = drm_dp_mst_topology_try_get_mstb(mstb); 2665 if (!ret) 2666 mstb = NULL; 2667 } 2668 mutex_unlock(&mgr->lock); 2669 if (!mstb) { 2670 mutex_unlock(&mgr->probe_lock); 2671 return; 2672 } 2673 2674 /* 2675 * Certain branch devices seem to incorrectly report an available_pbn 2676 * of 0 on downstream sinks, even after clearing the 2677 * DP_PAYLOAD_ALLOCATE_* registers in 2678 * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C 2679 * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make 2680 * things work again. 2681 */ 2682 if (clear_payload_id_table) { 2683 drm_dbg_kms(dev, "Clearing payload ID table\n"); 2684 drm_dp_send_clear_payload_id_table(mgr, mstb); 2685 } 2686 2687 ret = drm_dp_check_and_send_link_address(mgr, mstb); 2688 drm_dp_mst_topology_put_mstb(mstb); 2689 2690 mutex_unlock(&mgr->probe_lock); 2691 if (ret > 0) 2692 drm_kms_helper_hotplug_event(dev); 2693 } 2694 2695 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, 2696 u8 *guid) 2697 { 2698 u64 salt; 2699 2700 if (memchr_inv(guid, 0, 16)) 2701 return true; 2702 2703 salt = get_jiffies_64(); 2704 2705 memcpy(&guid[0], &salt, sizeof(u64)); 2706 memcpy(&guid[8], &salt, sizeof(u64)); 2707 2708 return false; 2709 } 2710 2711 static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, 2712 u8 port_num, u32 offset, u8 num_bytes) 2713 { 2714 struct drm_dp_sideband_msg_req_body req; 2715 2716 req.req_type = DP_REMOTE_DPCD_READ; 2717 req.u.dpcd_read.port_number = port_num; 2718 req.u.dpcd_read.dpcd_address = offset; 2719 req.u.dpcd_read.num_bytes = num_bytes; 2720 drm_dp_encode_sideband_req(&req, msg); 2721 } 2722 2723 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr, 2724 bool up, u8 *msg, int len) 2725 { 2726 int ret; 2727 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE; 2728 int tosend, total, offset; 2729 int retries = 0; 2730 2731 retry: 2732 total = len; 2733 offset = 0; 2734 do { 2735 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total); 2736 2737 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset, 2738 &msg[offset], 2739 tosend); 2740 if (ret != tosend) { 2741 if (ret == -EIO && retries < 5) { 2742 retries++; 2743 goto retry; 2744 } 2745 drm_dbg_kms(mgr->dev, "failed to dpcd write %d %d\n", tosend, ret); 2746 2747 return -EIO; 2748 } 2749 offset += tosend; 2750 total -= tosend; 2751 } while (total > 0); 2752 return 0; 2753 } 2754 2755 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr, 2756 struct drm_dp_sideband_msg_tx *txmsg) 2757 { 2758 struct drm_dp_mst_branch *mstb = txmsg->dst; 2759 u8 req_type; 2760 2761 req_type = txmsg->msg[0] & 0x7f; 2762 if (req_type == DP_CONNECTION_STATUS_NOTIFY || 2763 req_type == DP_RESOURCE_STATUS_NOTIFY || 2764 req_type == DP_CLEAR_PAYLOAD_ID_TABLE) 2765 hdr->broadcast = 1; 2766 else 2767 hdr->broadcast = 0; 2768 hdr->path_msg = txmsg->path_msg; 2769 if (hdr->broadcast) { 2770 hdr->lct = 1; 2771 hdr->lcr = 6; 2772 } else { 2773 hdr->lct = mstb->lct; 2774 hdr->lcr = mstb->lct - 1; 2775 } 2776 2777 memcpy(hdr->rad, mstb->rad, hdr->lct / 2); 2778 2779 return 0; 2780 } 2781 /* 2782 * process a single block of the next message in the sideband queue 2783 */ 2784 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr, 2785 struct drm_dp_sideband_msg_tx *txmsg, 2786 bool up) 2787 { 2788 u8 chunk[48]; 2789 struct drm_dp_sideband_msg_hdr hdr; 2790 int len, space, idx, tosend; 2791 int ret; 2792 2793 if (txmsg->state == DRM_DP_SIDEBAND_TX_SENT) 2794 return 0; 2795 2796 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr)); 2797 2798 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) 2799 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND; 2800 2801 /* make hdr from dst mst */ 2802 ret = set_hdr_from_dst_qlock(&hdr, txmsg); 2803 if (ret < 0) 2804 return ret; 2805 2806 /* amount left to send in this message */ 2807 len = txmsg->cur_len - txmsg->cur_offset; 2808 2809 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */ 2810 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr); 2811 2812 tosend = min(len, space); 2813 if (len == txmsg->cur_len) 2814 hdr.somt = 1; 2815 if (space >= len) 2816 hdr.eomt = 1; 2817 2818 2819 hdr.msg_len = tosend + 1; 2820 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx); 2821 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend); 2822 /* add crc at end */ 2823 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend); 2824 idx += tosend + 1; 2825 2826 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx); 2827 if (ret) { 2828 if (drm_debug_enabled(DRM_UT_DP)) { 2829 struct drm_printer p = drm_debug_printer(DBG_PREFIX); 2830 2831 drm_printf(&p, "sideband msg failed to send\n"); 2832 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 2833 } 2834 return ret; 2835 } 2836 2837 txmsg->cur_offset += tosend; 2838 if (txmsg->cur_offset == txmsg->cur_len) { 2839 txmsg->state = DRM_DP_SIDEBAND_TX_SENT; 2840 return 1; 2841 } 2842 return 0; 2843 } 2844 2845 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr) 2846 { 2847 struct drm_dp_sideband_msg_tx *txmsg; 2848 int ret; 2849 2850 WARN_ON(!mutex_is_locked(&mgr->qlock)); 2851 2852 /* construct a chunk from the first msg in the tx_msg queue */ 2853 if (list_empty(&mgr->tx_msg_downq)) 2854 return; 2855 2856 txmsg = list_first_entry(&mgr->tx_msg_downq, 2857 struct drm_dp_sideband_msg_tx, next); 2858 ret = process_single_tx_qlock(mgr, txmsg, false); 2859 if (ret < 0) { 2860 drm_dbg_kms(mgr->dev, "failed to send msg in q %d\n", ret); 2861 list_del(&txmsg->next); 2862 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 2863 wake_up_all(&mgr->tx_waitq); 2864 } 2865 } 2866 2867 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr, 2868 struct drm_dp_sideband_msg_tx *txmsg) 2869 { 2870 mutex_lock(&mgr->qlock); 2871 list_add_tail(&txmsg->next, &mgr->tx_msg_downq); 2872 2873 if (drm_debug_enabled(DRM_UT_DP)) { 2874 struct drm_printer p = drm_debug_printer(DBG_PREFIX); 2875 2876 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 2877 } 2878 2879 if (list_is_singular(&mgr->tx_msg_downq)) 2880 process_single_down_tx_qlock(mgr); 2881 mutex_unlock(&mgr->qlock); 2882 } 2883 2884 static void 2885 drm_dp_dump_link_address(const struct drm_dp_mst_topology_mgr *mgr, 2886 struct drm_dp_link_address_ack_reply *reply) 2887 { 2888 struct drm_dp_link_addr_reply_port *port_reply; 2889 int i; 2890 2891 for (i = 0; i < reply->nports; i++) { 2892 port_reply = &reply->ports[i]; 2893 drm_dbg_kms(mgr->dev, 2894 "port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", 2895 i, 2896 port_reply->input_port, 2897 port_reply->peer_device_type, 2898 port_reply->port_number, 2899 port_reply->dpcd_revision, 2900 port_reply->mcs, 2901 port_reply->ddps, 2902 port_reply->legacy_device_plug_status, 2903 port_reply->num_sdp_streams, 2904 port_reply->num_sdp_stream_sinks); 2905 } 2906 } 2907 2908 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 2909 struct drm_dp_mst_branch *mstb) 2910 { 2911 struct drm_dp_sideband_msg_tx *txmsg; 2912 struct drm_dp_link_address_ack_reply *reply; 2913 struct drm_dp_mst_port *port, *tmp; 2914 int i, ret, port_mask = 0; 2915 bool changed = false; 2916 2917 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 2918 if (!txmsg) 2919 return -ENOMEM; 2920 2921 txmsg->dst = mstb; 2922 build_link_address(txmsg); 2923 2924 mstb->link_address_sent = true; 2925 drm_dp_queue_down_tx(mgr, txmsg); 2926 2927 /* FIXME: Actually do some real error handling here */ 2928 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 2929 if (ret < 0) { 2930 drm_err(mgr->dev, "Sending link address failed with %d\n", ret); 2931 goto out; 2932 } 2933 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 2934 drm_err(mgr->dev, "link address NAK received\n"); 2935 ret = -EIO; 2936 goto out; 2937 } 2938 2939 reply = &txmsg->reply.u.link_addr; 2940 drm_dbg_kms(mgr->dev, "link address reply: %d\n", reply->nports); 2941 drm_dp_dump_link_address(mgr, reply); 2942 2943 ret = drm_dp_check_mstb_guid(mstb, reply->guid); 2944 if (ret) { 2945 char buf[64]; 2946 2947 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf)); 2948 drm_err(mgr->dev, "GUID check on %s failed: %d\n", buf, ret); 2949 goto out; 2950 } 2951 2952 for (i = 0; i < reply->nports; i++) { 2953 port_mask |= BIT(reply->ports[i].port_number); 2954 ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev, 2955 &reply->ports[i]); 2956 if (ret == 1) 2957 changed = true; 2958 else if (ret < 0) 2959 goto out; 2960 } 2961 2962 /* Prune any ports that are currently a part of mstb in our in-memory 2963 * topology, but were not seen in this link address. Usually this 2964 * means that they were removed while the topology was out of sync, 2965 * e.g. during suspend/resume 2966 */ 2967 mutex_lock(&mgr->lock); 2968 list_for_each_entry_safe(port, tmp, &mstb->ports, next) { 2969 if (port_mask & BIT(port->port_num)) 2970 continue; 2971 2972 drm_dbg_kms(mgr->dev, "port %d was not in link address, removing\n", 2973 port->port_num); 2974 list_del(&port->next); 2975 drm_dp_mst_topology_put_port(port); 2976 changed = true; 2977 } 2978 mutex_unlock(&mgr->lock); 2979 2980 out: 2981 if (ret < 0) 2982 mstb->link_address_sent = false; 2983 kfree(txmsg); 2984 return ret < 0 ? ret : changed; 2985 } 2986 2987 static void 2988 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr, 2989 struct drm_dp_mst_branch *mstb) 2990 { 2991 struct drm_dp_sideband_msg_tx *txmsg; 2992 int ret; 2993 2994 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 2995 if (!txmsg) 2996 return; 2997 2998 txmsg->dst = mstb; 2999 build_clear_payload_id_table(txmsg); 3000 3001 drm_dp_queue_down_tx(mgr, txmsg); 3002 3003 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3004 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3005 drm_dbg_kms(mgr->dev, "clear payload table id nak received\n"); 3006 3007 kfree(txmsg); 3008 } 3009 3010 static int 3011 drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, 3012 struct drm_dp_mst_branch *mstb, 3013 struct drm_dp_mst_port *port) 3014 { 3015 struct drm_dp_enum_path_resources_ack_reply *path_res; 3016 struct drm_dp_sideband_msg_tx *txmsg; 3017 int ret; 3018 3019 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3020 if (!txmsg) 3021 return -ENOMEM; 3022 3023 txmsg->dst = mstb; 3024 build_enum_path_resources(txmsg, port->port_num); 3025 3026 drm_dp_queue_down_tx(mgr, txmsg); 3027 3028 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3029 if (ret > 0) { 3030 ret = 0; 3031 path_res = &txmsg->reply.u.path_resources; 3032 3033 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3034 drm_dbg_kms(mgr->dev, "enum path resources nak received\n"); 3035 } else { 3036 if (port->port_num != path_res->port_number) 3037 DRM_ERROR("got incorrect port in response\n"); 3038 3039 drm_dbg_kms(mgr->dev, "enum path resources %d: %d %d\n", 3040 path_res->port_number, 3041 path_res->full_payload_bw_number, 3042 path_res->avail_payload_bw_number); 3043 3044 /* 3045 * If something changed, make sure we send a 3046 * hotplug 3047 */ 3048 if (port->full_pbn != path_res->full_payload_bw_number || 3049 port->fec_capable != path_res->fec_capable) 3050 ret = 1; 3051 3052 port->full_pbn = path_res->full_payload_bw_number; 3053 port->fec_capable = path_res->fec_capable; 3054 } 3055 } 3056 3057 kfree(txmsg); 3058 return ret; 3059 } 3060 3061 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb) 3062 { 3063 if (!mstb->port_parent) 3064 return NULL; 3065 3066 if (mstb->port_parent->mstb != mstb) 3067 return mstb->port_parent; 3068 3069 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent); 3070 } 3071 3072 /* 3073 * Searches upwards in the topology starting from mstb to try to find the 3074 * closest available parent of mstb that's still connected to the rest of the 3075 * topology. This can be used in order to perform operations like releasing 3076 * payloads, where the branch device which owned the payload may no longer be 3077 * around and thus would require that the payload on the last living relative 3078 * be freed instead. 3079 */ 3080 static struct drm_dp_mst_branch * 3081 drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr, 3082 struct drm_dp_mst_branch *mstb, 3083 int *port_num) 3084 { 3085 struct drm_dp_mst_branch *rmstb = NULL; 3086 struct drm_dp_mst_port *found_port; 3087 3088 mutex_lock(&mgr->lock); 3089 if (!mgr->mst_primary) 3090 goto out; 3091 3092 do { 3093 found_port = drm_dp_get_last_connected_port_to_mstb(mstb); 3094 if (!found_port) 3095 break; 3096 3097 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) { 3098 rmstb = found_port->parent; 3099 *port_num = found_port->port_num; 3100 } else { 3101 /* Search again, starting from this parent */ 3102 mstb = found_port->parent; 3103 } 3104 } while (!rmstb); 3105 out: 3106 mutex_unlock(&mgr->lock); 3107 return rmstb; 3108 } 3109 3110 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr, 3111 struct drm_dp_mst_port *port, 3112 int id, 3113 int pbn) 3114 { 3115 struct drm_dp_sideband_msg_tx *txmsg; 3116 struct drm_dp_mst_branch *mstb; 3117 int ret, port_num; 3118 u8 sinks[DRM_DP_MAX_SDP_STREAMS]; 3119 int i; 3120 3121 port_num = port->port_num; 3122 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 3123 if (!mstb) { 3124 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, 3125 port->parent, 3126 &port_num); 3127 3128 if (!mstb) 3129 return -EINVAL; 3130 } 3131 3132 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3133 if (!txmsg) { 3134 ret = -ENOMEM; 3135 goto fail_put; 3136 } 3137 3138 for (i = 0; i < port->num_sdp_streams; i++) 3139 sinks[i] = i; 3140 3141 txmsg->dst = mstb; 3142 build_allocate_payload(txmsg, port_num, 3143 id, 3144 pbn, port->num_sdp_streams, sinks); 3145 3146 drm_dp_queue_down_tx(mgr, txmsg); 3147 3148 /* 3149 * FIXME: there is a small chance that between getting the last 3150 * connected mstb and sending the payload message, the last connected 3151 * mstb could also be removed from the topology. In the future, this 3152 * needs to be fixed by restarting the 3153 * drm_dp_get_last_connected_port_and_mstb() search in the event of a 3154 * timeout if the topology is still connected to the system. 3155 */ 3156 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3157 if (ret > 0) { 3158 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3159 ret = -EINVAL; 3160 else 3161 ret = 0; 3162 } 3163 kfree(txmsg); 3164 fail_put: 3165 drm_dp_mst_topology_put_mstb(mstb); 3166 return ret; 3167 } 3168 3169 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr, 3170 struct drm_dp_mst_port *port, bool power_up) 3171 { 3172 struct drm_dp_sideband_msg_tx *txmsg; 3173 int ret; 3174 3175 port = drm_dp_mst_topology_get_port_validated(mgr, port); 3176 if (!port) 3177 return -EINVAL; 3178 3179 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3180 if (!txmsg) { 3181 drm_dp_mst_topology_put_port(port); 3182 return -ENOMEM; 3183 } 3184 3185 txmsg->dst = port->parent; 3186 build_power_updown_phy(txmsg, port->port_num, power_up); 3187 drm_dp_queue_down_tx(mgr, txmsg); 3188 3189 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg); 3190 if (ret > 0) { 3191 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3192 ret = -EINVAL; 3193 else 3194 ret = 0; 3195 } 3196 kfree(txmsg); 3197 drm_dp_mst_topology_put_port(port); 3198 3199 return ret; 3200 } 3201 EXPORT_SYMBOL(drm_dp_send_power_updown_phy); 3202 3203 int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr, 3204 struct drm_dp_mst_port *port, 3205 struct drm_dp_query_stream_enc_status_ack_reply *status) 3206 { 3207 struct drm_dp_mst_topology_state *state; 3208 struct drm_dp_mst_atomic_payload *payload; 3209 struct drm_dp_sideband_msg_tx *txmsg; 3210 u8 nonce[7]; 3211 int ret; 3212 3213 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3214 if (!txmsg) 3215 return -ENOMEM; 3216 3217 port = drm_dp_mst_topology_get_port_validated(mgr, port); 3218 if (!port) { 3219 ret = -EINVAL; 3220 goto out_get_port; 3221 } 3222 3223 get_random_bytes(nonce, sizeof(nonce)); 3224 3225 drm_modeset_lock(&mgr->base.lock, NULL); 3226 state = to_drm_dp_mst_topology_state(mgr->base.state); 3227 payload = drm_atomic_get_mst_payload_state(state, port); 3228 3229 /* 3230 * "Source device targets the QUERY_STREAM_ENCRYPTION_STATUS message 3231 * transaction at the MST Branch device directly connected to the 3232 * Source" 3233 */ 3234 txmsg->dst = mgr->mst_primary; 3235 3236 build_query_stream_enc_status(txmsg, payload->vcpi, nonce); 3237 3238 drm_dp_queue_down_tx(mgr, txmsg); 3239 3240 ret = drm_dp_mst_wait_tx_reply(mgr->mst_primary, txmsg); 3241 if (ret < 0) { 3242 goto out; 3243 } else if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3244 drm_dbg_kms(mgr->dev, "query encryption status nak received\n"); 3245 ret = -ENXIO; 3246 goto out; 3247 } 3248 3249 ret = 0; 3250 memcpy(status, &txmsg->reply.u.enc_status, sizeof(*status)); 3251 3252 out: 3253 drm_modeset_unlock(&mgr->base.lock); 3254 drm_dp_mst_topology_put_port(port); 3255 out_get_port: 3256 kfree(txmsg); 3257 return ret; 3258 } 3259 EXPORT_SYMBOL(drm_dp_send_query_stream_enc_status); 3260 3261 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr, 3262 struct drm_dp_mst_atomic_payload *payload) 3263 { 3264 return drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot, 3265 payload->time_slots); 3266 } 3267 3268 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr, 3269 struct drm_dp_mst_atomic_payload *payload) 3270 { 3271 int ret; 3272 struct drm_dp_mst_port *port = drm_dp_mst_topology_get_port_validated(mgr, payload->port); 3273 3274 if (!port) 3275 return -EIO; 3276 3277 ret = drm_dp_payload_send_msg(mgr, port, payload->vcpi, payload->pbn); 3278 drm_dp_mst_topology_put_port(port); 3279 return ret; 3280 } 3281 3282 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr, 3283 struct drm_dp_mst_topology_state *mst_state, 3284 struct drm_dp_mst_atomic_payload *payload) 3285 { 3286 drm_dbg_kms(mgr->dev, "\n"); 3287 3288 /* it's okay for these to fail */ 3289 drm_dp_payload_send_msg(mgr, payload->port, payload->vcpi, 0); 3290 drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot, 0); 3291 3292 return 0; 3293 } 3294 3295 /** 3296 * drm_dp_add_payload_part1() - Execute payload update part 1 3297 * @mgr: Manager to use. 3298 * @mst_state: The MST atomic state 3299 * @payload: The payload to write 3300 * 3301 * Determines the starting time slot for the given payload, and programs the VCPI for this payload 3302 * into hardware. After calling this, the driver should generate ACT and payload packets. 3303 * 3304 * Returns: 0 on success, error code on failure. In the event that this fails, 3305 * @payload.vc_start_slot will also be set to -1. 3306 */ 3307 int drm_dp_add_payload_part1(struct drm_dp_mst_topology_mgr *mgr, 3308 struct drm_dp_mst_topology_state *mst_state, 3309 struct drm_dp_mst_atomic_payload *payload) 3310 { 3311 struct drm_dp_mst_port *port; 3312 int ret; 3313 3314 port = drm_dp_mst_topology_get_port_validated(mgr, payload->port); 3315 if (!port) { 3316 drm_dbg_kms(mgr->dev, 3317 "VCPI %d for port %p not in topology, not creating a payload\n", 3318 payload->vcpi, payload->port); 3319 payload->vc_start_slot = -1; 3320 return 0; 3321 } 3322 3323 if (mgr->payload_count == 0) 3324 mgr->next_start_slot = mst_state->start_slot; 3325 3326 payload->vc_start_slot = mgr->next_start_slot; 3327 3328 ret = drm_dp_create_payload_step1(mgr, payload); 3329 drm_dp_mst_topology_put_port(port); 3330 if (ret < 0) { 3331 drm_warn(mgr->dev, "Failed to create MST payload for port %p: %d\n", 3332 payload->port, ret); 3333 payload->vc_start_slot = -1; 3334 return ret; 3335 } 3336 3337 mgr->payload_count++; 3338 mgr->next_start_slot += payload->time_slots; 3339 3340 return 0; 3341 } 3342 EXPORT_SYMBOL(drm_dp_add_payload_part1); 3343 3344 /** 3345 * drm_dp_remove_payload() - Remove an MST payload 3346 * @mgr: Manager to use. 3347 * @mst_state: The MST atomic state 3348 * @old_payload: The payload with its old state 3349 * @new_payload: The payload to write 3350 * 3351 * Removes a payload from an MST topology if it was successfully assigned a start slot. Also updates 3352 * the starting time slots of all other payloads which would have been shifted towards the start of 3353 * the VC table as a result. After calling this, the driver should generate ACT and payload packets. 3354 */ 3355 void drm_dp_remove_payload(struct drm_dp_mst_topology_mgr *mgr, 3356 struct drm_dp_mst_topology_state *mst_state, 3357 const struct drm_dp_mst_atomic_payload *old_payload, 3358 struct drm_dp_mst_atomic_payload *new_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 (new_payload->vc_start_slot == -1) 3365 return; 3366 3367 mutex_lock(&mgr->lock); 3368 send_remove = drm_dp_mst_port_downstream_of_branch(new_payload->port, mgr->mst_primary); 3369 mutex_unlock(&mgr->lock); 3370 3371 if (send_remove) 3372 drm_dp_destroy_payload_step1(mgr, mst_state, new_payload); 3373 else 3374 drm_dbg_kms(mgr->dev, "Payload for VCPI %d not in topology, not sending remove\n", 3375 new_payload->vcpi); 3376 3377 list_for_each_entry(pos, &mst_state->payloads, next) { 3378 if (pos != new_payload && pos->vc_start_slot > new_payload->vc_start_slot) 3379 pos->vc_start_slot -= old_payload->time_slots; 3380 } 3381 new_payload->vc_start_slot = -1; 3382 3383 mgr->payload_count--; 3384 mgr->next_start_slot -= old_payload->time_slots; 3385 3386 if (new_payload->delete) 3387 drm_dp_mst_put_port_malloc(new_payload->port); 3388 } 3389 EXPORT_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 */ 3402 int 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(mgr->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 } 3427 EXPORT_SYMBOL(drm_dp_add_payload_part2); 3428 3429 static 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 3472 fail_free: 3473 kfree(txmsg); 3474 fail_put: 3475 drm_dp_mst_topology_put_mstb(mstb); 3476 3477 return ret; 3478 } 3479 3480 static 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); 3512 fail_put: 3513 drm_dp_mst_topology_put_mstb(mstb); 3514 return ret; 3515 } 3516 3517 static 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 3527 static 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 */ 3560 int 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 } 3570 EXPORT_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 */ 3579 bool 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 } 3592 EXPORT_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 */ 3602 int 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 mgr->reset_rx_state = true; 3659 } 3660 3661 out_unlock: 3662 mutex_unlock(&mgr->lock); 3663 if (mstb) 3664 drm_dp_mst_topology_put_mstb(mstb); 3665 return ret; 3666 3667 } 3668 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst); 3669 3670 static void 3671 drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb) 3672 { 3673 struct drm_dp_mst_port *port; 3674 3675 /* The link address will need to be re-sent on resume */ 3676 mstb->link_address_sent = false; 3677 3678 list_for_each_entry(port, &mstb->ports, next) 3679 if (port->mstb) 3680 drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb); 3681 } 3682 3683 /** 3684 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager 3685 * @mgr: manager to suspend 3686 * 3687 * This function tells the MST device that we can't handle UP messages 3688 * anymore. This should stop it from sending any since we are suspended. 3689 */ 3690 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr) 3691 { 3692 mutex_lock(&mgr->lock); 3693 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 3694 DP_MST_EN | DP_UPSTREAM_IS_SRC); 3695 mutex_unlock(&mgr->lock); 3696 flush_work(&mgr->up_req_work); 3697 flush_work(&mgr->work); 3698 flush_work(&mgr->delayed_destroy_work); 3699 3700 mutex_lock(&mgr->lock); 3701 if (mgr->mst_state && mgr->mst_primary) 3702 drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary); 3703 mutex_unlock(&mgr->lock); 3704 } 3705 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend); 3706 3707 /** 3708 * drm_dp_mst_topology_mgr_resume() - resume the MST manager 3709 * @mgr: manager to resume 3710 * @sync: whether or not to perform topology reprobing synchronously 3711 * 3712 * This will fetch DPCD and see if the device is still there, 3713 * if it is, it will rewrite the MSTM control bits, and return. 3714 * 3715 * If the device fails this returns -1, and the driver should do 3716 * a full MST reprobe, in case we were undocked. 3717 * 3718 * During system resume (where it is assumed that the driver will be calling 3719 * drm_atomic_helper_resume()) this function should be called beforehand with 3720 * @sync set to true. In contexts like runtime resume where the driver is not 3721 * expected to be calling drm_atomic_helper_resume(), this function should be 3722 * called with @sync set to false in order to avoid deadlocking. 3723 * 3724 * Returns: -1 if the MST topology was removed while we were suspended, 0 3725 * otherwise. 3726 */ 3727 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr, 3728 bool sync) 3729 { 3730 int ret; 3731 u8 guid[16]; 3732 3733 mutex_lock(&mgr->lock); 3734 if (!mgr->mst_primary) 3735 goto out_fail; 3736 3737 if (drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd) < 0) { 3738 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n"); 3739 goto out_fail; 3740 } 3741 3742 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 3743 DP_MST_EN | 3744 DP_UP_REQ_EN | 3745 DP_UPSTREAM_IS_SRC); 3746 if (ret < 0) { 3747 drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n"); 3748 goto out_fail; 3749 } 3750 3751 /* Some hubs forget their guids after they resume */ 3752 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16); 3753 if (ret != 16) { 3754 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n"); 3755 goto out_fail; 3756 } 3757 3758 ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid); 3759 if (ret) { 3760 drm_dbg_kms(mgr->dev, "check mstb failed - undocked during suspend?\n"); 3761 goto out_fail; 3762 } 3763 3764 /* 3765 * For the final step of resuming the topology, we need to bring the 3766 * state of our in-memory topology back into sync with reality. So, 3767 * restart the probing process as if we're probing a new hub 3768 */ 3769 queue_work(system_long_wq, &mgr->work); 3770 mutex_unlock(&mgr->lock); 3771 3772 if (sync) { 3773 drm_dbg_kms(mgr->dev, 3774 "Waiting for link probe work to finish re-syncing topology...\n"); 3775 flush_work(&mgr->work); 3776 } 3777 3778 return 0; 3779 3780 out_fail: 3781 mutex_unlock(&mgr->lock); 3782 return -1; 3783 } 3784 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume); 3785 3786 static void reset_msg_rx_state(struct drm_dp_sideband_msg_rx *msg) 3787 { 3788 memset(msg, 0, sizeof(*msg)); 3789 } 3790 3791 static bool 3792 drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up, 3793 struct drm_dp_mst_branch **mstb) 3794 { 3795 int len; 3796 u8 replyblock[32]; 3797 int replylen, curreply; 3798 int ret; 3799 u8 hdrlen; 3800 struct drm_dp_sideband_msg_hdr hdr; 3801 struct drm_dp_sideband_msg_rx *msg = 3802 up ? &mgr->up_req_recv : &mgr->down_rep_recv; 3803 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : 3804 DP_SIDEBAND_MSG_DOWN_REP_BASE; 3805 3806 if (!up) 3807 *mstb = NULL; 3808 3809 len = min(mgr->max_dpcd_transaction_bytes, 16); 3810 ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len); 3811 if (ret != len) { 3812 drm_dbg_kms(mgr->dev, "failed to read DPCD down rep %d %d\n", len, ret); 3813 return false; 3814 } 3815 3816 ret = drm_dp_decode_sideband_msg_hdr(mgr, &hdr, replyblock, len, &hdrlen); 3817 if (ret == false) { 3818 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 3819 1, replyblock, len, false); 3820 drm_dbg_kms(mgr->dev, "ERROR: failed header\n"); 3821 return false; 3822 } 3823 3824 if (!up) { 3825 /* Caller is responsible for giving back this reference */ 3826 *mstb = drm_dp_get_mst_branch_device(mgr, hdr.lct, hdr.rad); 3827 if (!*mstb) { 3828 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr.lct); 3829 return false; 3830 } 3831 } 3832 3833 if (!drm_dp_sideband_msg_set_header(msg, &hdr, hdrlen)) { 3834 drm_dbg_kms(mgr->dev, "sideband msg set header failed %d\n", replyblock[0]); 3835 return false; 3836 } 3837 3838 replylen = min(msg->curchunk_len, (u8)(len - hdrlen)); 3839 ret = drm_dp_sideband_append_payload(msg, replyblock + hdrlen, replylen); 3840 if (!ret) { 3841 drm_dbg_kms(mgr->dev, "sideband msg build failed %d\n", replyblock[0]); 3842 return false; 3843 } 3844 3845 replylen = msg->curchunk_len + msg->curchunk_hdrlen - len; 3846 curreply = len; 3847 while (replylen > 0) { 3848 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16); 3849 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply, 3850 replyblock, len); 3851 if (ret != len) { 3852 drm_dbg_kms(mgr->dev, "failed to read a chunk (len %d, ret %d)\n", 3853 len, ret); 3854 return false; 3855 } 3856 3857 ret = drm_dp_sideband_append_payload(msg, replyblock, len); 3858 if (!ret) { 3859 drm_dbg_kms(mgr->dev, "failed to build sideband msg\n"); 3860 return false; 3861 } 3862 3863 curreply += len; 3864 replylen -= len; 3865 } 3866 return true; 3867 } 3868 3869 static int get_msg_request_type(u8 data) 3870 { 3871 return data & 0x7f; 3872 } 3873 3874 static bool verify_rx_request_type(struct drm_dp_mst_topology_mgr *mgr, 3875 const struct drm_dp_sideband_msg_tx *txmsg, 3876 const struct drm_dp_sideband_msg_rx *rxmsg) 3877 { 3878 const struct drm_dp_sideband_msg_hdr *hdr = &rxmsg->initial_hdr; 3879 const struct drm_dp_mst_branch *mstb = txmsg->dst; 3880 int tx_req_type = get_msg_request_type(txmsg->msg[0]); 3881 int rx_req_type = get_msg_request_type(rxmsg->msg[0]); 3882 char rad_str[64]; 3883 3884 if (tx_req_type == rx_req_type) 3885 return true; 3886 3887 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, rad_str, sizeof(rad_str)); 3888 drm_dbg_kms(mgr->dev, 3889 "Got unexpected MST reply, mstb: %p seqno: %d lct: %d rad: %s rx_req_type: %s (%02x) != tx_req_type: %s (%02x)\n", 3890 mstb, hdr->seqno, mstb->lct, rad_str, 3891 drm_dp_mst_req_type_str(rx_req_type), rx_req_type, 3892 drm_dp_mst_req_type_str(tx_req_type), tx_req_type); 3893 3894 return false; 3895 } 3896 3897 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr) 3898 { 3899 struct drm_dp_sideband_msg_tx *txmsg; 3900 struct drm_dp_mst_branch *mstb = NULL; 3901 struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv; 3902 3903 if (!drm_dp_get_one_sb_msg(mgr, false, &mstb)) 3904 goto out_clear_reply; 3905 3906 /* Multi-packet message transmission, don't clear the reply */ 3907 if (!msg->have_eomt) 3908 goto out; 3909 3910 /* find the message */ 3911 mutex_lock(&mgr->qlock); 3912 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq, 3913 struct drm_dp_sideband_msg_tx, next); 3914 mutex_unlock(&mgr->qlock); 3915 3916 /* Were we actually expecting a response, and from this mstb? */ 3917 if (!txmsg || txmsg->dst != mstb) { 3918 struct drm_dp_sideband_msg_hdr *hdr; 3919 3920 hdr = &msg->initial_hdr; 3921 drm_dbg_kms(mgr->dev, "Got MST reply with no msg %p %d %d %02x %02x\n", 3922 mstb, hdr->seqno, hdr->lct, hdr->rad[0], msg->msg[0]); 3923 goto out_clear_reply; 3924 } 3925 3926 if (!verify_rx_request_type(mgr, txmsg, msg)) 3927 goto out_clear_reply; 3928 3929 drm_dp_sideband_parse_reply(mgr, msg, &txmsg->reply); 3930 3931 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3932 drm_dbg_kms(mgr->dev, 3933 "Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n", 3934 txmsg->reply.req_type, 3935 drm_dp_mst_req_type_str(txmsg->reply.req_type), 3936 txmsg->reply.u.nak.reason, 3937 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason), 3938 txmsg->reply.u.nak.nak_data); 3939 } 3940 3941 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx)); 3942 drm_dp_mst_topology_put_mstb(mstb); 3943 3944 mutex_lock(&mgr->qlock); 3945 txmsg->state = DRM_DP_SIDEBAND_TX_RX; 3946 list_del(&txmsg->next); 3947 mutex_unlock(&mgr->qlock); 3948 3949 wake_up_all(&mgr->tx_waitq); 3950 3951 return 0; 3952 3953 out_clear_reply: 3954 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx)); 3955 out: 3956 if (mstb) 3957 drm_dp_mst_topology_put_mstb(mstb); 3958 3959 return 0; 3960 } 3961 3962 static inline bool 3963 drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr, 3964 struct drm_dp_pending_up_req *up_req) 3965 { 3966 struct drm_dp_mst_branch *mstb = NULL; 3967 struct drm_dp_sideband_msg_req_body *msg = &up_req->msg; 3968 struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr; 3969 bool hotplug = false, dowork = false; 3970 3971 if (hdr->broadcast) { 3972 const u8 *guid = NULL; 3973 3974 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) 3975 guid = msg->u.conn_stat.guid; 3976 else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY) 3977 guid = msg->u.resource_stat.guid; 3978 3979 if (guid) 3980 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid); 3981 } else { 3982 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad); 3983 } 3984 3985 if (!mstb) { 3986 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr->lct); 3987 return false; 3988 } 3989 3990 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */ 3991 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) { 3992 dowork = drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat); 3993 hotplug = true; 3994 } 3995 3996 drm_dp_mst_topology_put_mstb(mstb); 3997 3998 if (dowork) 3999 queue_work(system_long_wq, &mgr->work); 4000 return hotplug; 4001 } 4002 4003 static void drm_dp_mst_up_req_work(struct work_struct *work) 4004 { 4005 struct drm_dp_mst_topology_mgr *mgr = 4006 container_of(work, struct drm_dp_mst_topology_mgr, 4007 up_req_work); 4008 struct drm_dp_pending_up_req *up_req; 4009 bool send_hotplug = false; 4010 4011 mutex_lock(&mgr->probe_lock); 4012 while (true) { 4013 mutex_lock(&mgr->up_req_lock); 4014 up_req = list_first_entry_or_null(&mgr->up_req_list, 4015 struct drm_dp_pending_up_req, 4016 next); 4017 if (up_req) 4018 list_del(&up_req->next); 4019 mutex_unlock(&mgr->up_req_lock); 4020 4021 if (!up_req) 4022 break; 4023 4024 send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req); 4025 kfree(up_req); 4026 } 4027 mutex_unlock(&mgr->probe_lock); 4028 4029 if (send_hotplug) 4030 drm_kms_helper_hotplug_event(mgr->dev); 4031 } 4032 4033 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr) 4034 { 4035 struct drm_dp_pending_up_req *up_req; 4036 4037 if (!drm_dp_get_one_sb_msg(mgr, true, NULL)) 4038 goto out; 4039 4040 if (!mgr->up_req_recv.have_eomt) 4041 return 0; 4042 4043 up_req = kzalloc(sizeof(*up_req), GFP_KERNEL); 4044 if (!up_req) 4045 return -ENOMEM; 4046 4047 INIT_LIST_HEAD(&up_req->next); 4048 4049 drm_dp_sideband_parse_req(mgr, &mgr->up_req_recv, &up_req->msg); 4050 4051 if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY && 4052 up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) { 4053 drm_dbg_kms(mgr->dev, "Received unknown up req type, ignoring: %x\n", 4054 up_req->msg.req_type); 4055 kfree(up_req); 4056 goto out; 4057 } 4058 4059 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type, 4060 false); 4061 4062 if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) { 4063 const struct drm_dp_connection_status_notify *conn_stat = 4064 &up_req->msg.u.conn_stat; 4065 bool handle_csn; 4066 4067 drm_dbg_kms(mgr->dev, "Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", 4068 conn_stat->port_number, 4069 conn_stat->legacy_device_plug_status, 4070 conn_stat->displayport_device_plug_status, 4071 conn_stat->message_capability_status, 4072 conn_stat->input_port, 4073 conn_stat->peer_device_type); 4074 4075 mutex_lock(&mgr->probe_lock); 4076 handle_csn = mgr->mst_primary->link_address_sent; 4077 mutex_unlock(&mgr->probe_lock); 4078 4079 if (!handle_csn) { 4080 drm_dbg_kms(mgr->dev, "Got CSN before finish topology probing. Skip it."); 4081 kfree(up_req); 4082 goto out; 4083 } 4084 } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) { 4085 const struct drm_dp_resource_status_notify *res_stat = 4086 &up_req->msg.u.resource_stat; 4087 4088 drm_dbg_kms(mgr->dev, "Got RSN: pn: %d avail_pbn %d\n", 4089 res_stat->port_number, 4090 res_stat->available_pbn); 4091 } 4092 4093 up_req->hdr = mgr->up_req_recv.initial_hdr; 4094 mutex_lock(&mgr->up_req_lock); 4095 list_add_tail(&up_req->next, &mgr->up_req_list); 4096 mutex_unlock(&mgr->up_req_lock); 4097 queue_work(system_long_wq, &mgr->up_req_work); 4098 4099 out: 4100 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 4101 return 0; 4102 } 4103 4104 static void update_msg_rx_state(struct drm_dp_mst_topology_mgr *mgr) 4105 { 4106 mutex_lock(&mgr->lock); 4107 if (mgr->reset_rx_state) { 4108 mgr->reset_rx_state = false; 4109 reset_msg_rx_state(&mgr->down_rep_recv); 4110 reset_msg_rx_state(&mgr->up_req_recv); 4111 } 4112 mutex_unlock(&mgr->lock); 4113 } 4114 4115 /** 4116 * drm_dp_mst_hpd_irq_handle_event() - MST hotplug IRQ handle MST event 4117 * @mgr: manager to notify irq for. 4118 * @esi: 4 bytes from SINK_COUNT_ESI 4119 * @ack: 4 bytes used to ack events starting from SINK_COUNT_ESI 4120 * @handled: whether the hpd interrupt was consumed or not 4121 * 4122 * This should be called from the driver when it detects a HPD IRQ, 4123 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The 4124 * topology manager will process the sideband messages received 4125 * as indicated in the DEVICE_SERVICE_IRQ_VECTOR_ESI0 and set the 4126 * corresponding flags that Driver has to ack the DP receiver later. 4127 * 4128 * Note that driver shall also call 4129 * drm_dp_mst_hpd_irq_send_new_request() if the 'handled' is set 4130 * after calling this function, to try to kick off a new request in 4131 * the queue if the previous message transaction is completed. 4132 * 4133 * See also: 4134 * drm_dp_mst_hpd_irq_send_new_request() 4135 */ 4136 int drm_dp_mst_hpd_irq_handle_event(struct drm_dp_mst_topology_mgr *mgr, const u8 *esi, 4137 u8 *ack, bool *handled) 4138 { 4139 int ret = 0; 4140 int sc; 4141 *handled = false; 4142 sc = DP_GET_SINK_COUNT(esi[0]); 4143 4144 if (sc != mgr->sink_count) { 4145 mgr->sink_count = sc; 4146 *handled = true; 4147 } 4148 4149 update_msg_rx_state(mgr); 4150 4151 if (esi[1] & DP_DOWN_REP_MSG_RDY) { 4152 ret = drm_dp_mst_handle_down_rep(mgr); 4153 *handled = true; 4154 ack[1] |= DP_DOWN_REP_MSG_RDY; 4155 } 4156 4157 if (esi[1] & DP_UP_REQ_MSG_RDY) { 4158 ret |= drm_dp_mst_handle_up_req(mgr); 4159 *handled = true; 4160 ack[1] |= DP_UP_REQ_MSG_RDY; 4161 } 4162 4163 return ret; 4164 } 4165 EXPORT_SYMBOL(drm_dp_mst_hpd_irq_handle_event); 4166 4167 /** 4168 * drm_dp_mst_hpd_irq_send_new_request() - MST hotplug IRQ kick off new request 4169 * @mgr: manager to notify irq for. 4170 * 4171 * This should be called from the driver when mst irq event is handled 4172 * and acked. Note that new down request should only be sent when 4173 * previous message transaction is completed. Source is not supposed to generate 4174 * interleaved message transactions. 4175 */ 4176 void drm_dp_mst_hpd_irq_send_new_request(struct drm_dp_mst_topology_mgr *mgr) 4177 { 4178 struct drm_dp_sideband_msg_tx *txmsg; 4179 bool kick = true; 4180 4181 mutex_lock(&mgr->qlock); 4182 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq, 4183 struct drm_dp_sideband_msg_tx, next); 4184 /* If last transaction is not completed yet*/ 4185 if (!txmsg || 4186 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND || 4187 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) 4188 kick = false; 4189 mutex_unlock(&mgr->qlock); 4190 4191 if (kick) 4192 drm_dp_mst_kick_tx(mgr); 4193 } 4194 EXPORT_SYMBOL(drm_dp_mst_hpd_irq_send_new_request); 4195 /** 4196 * drm_dp_mst_detect_port() - get connection status for an MST port 4197 * @connector: DRM connector for this port 4198 * @ctx: The acquisition context to use for grabbing locks 4199 * @mgr: manager for this port 4200 * @port: pointer to a port 4201 * 4202 * This returns the current connection state for a port. 4203 */ 4204 int 4205 drm_dp_mst_detect_port(struct drm_connector *connector, 4206 struct drm_modeset_acquire_ctx *ctx, 4207 struct drm_dp_mst_topology_mgr *mgr, 4208 struct drm_dp_mst_port *port) 4209 { 4210 int ret; 4211 4212 /* we need to search for the port in the mgr in case it's gone */ 4213 port = drm_dp_mst_topology_get_port_validated(mgr, port); 4214 if (!port) 4215 return connector_status_disconnected; 4216 4217 ret = drm_modeset_lock(&mgr->base.lock, ctx); 4218 if (ret) 4219 goto out; 4220 4221 ret = connector_status_disconnected; 4222 4223 if (!port->ddps) 4224 goto out; 4225 4226 switch (port->pdt) { 4227 case DP_PEER_DEVICE_NONE: 4228 break; 4229 case DP_PEER_DEVICE_MST_BRANCHING: 4230 if (!port->mcs) 4231 ret = connector_status_connected; 4232 break; 4233 4234 case DP_PEER_DEVICE_SST_SINK: 4235 ret = connector_status_connected; 4236 /* for logical ports - cache the EDID */ 4237 if (port->port_num >= DP_MST_LOGICAL_PORT_0 && !port->cached_edid) 4238 port->cached_edid = drm_edid_read_ddc(connector, &port->aux.ddc); 4239 break; 4240 case DP_PEER_DEVICE_DP_LEGACY_CONV: 4241 if (port->ldps) 4242 ret = connector_status_connected; 4243 break; 4244 } 4245 out: 4246 drm_dp_mst_topology_put_port(port); 4247 return ret; 4248 } 4249 EXPORT_SYMBOL(drm_dp_mst_detect_port); 4250 4251 /** 4252 * drm_dp_mst_edid_read() - get EDID for an MST port 4253 * @connector: toplevel connector to get EDID for 4254 * @mgr: manager for this port 4255 * @port: unverified pointer to a port. 4256 * 4257 * This returns an EDID for the port connected to a connector, 4258 * It validates the pointer still exists so the caller doesn't require a 4259 * reference. 4260 */ 4261 const struct drm_edid *drm_dp_mst_edid_read(struct drm_connector *connector, 4262 struct drm_dp_mst_topology_mgr *mgr, 4263 struct drm_dp_mst_port *port) 4264 { 4265 const struct drm_edid *drm_edid; 4266 4267 /* we need to search for the port in the mgr in case it's gone */ 4268 port = drm_dp_mst_topology_get_port_validated(mgr, port); 4269 if (!port) 4270 return NULL; 4271 4272 if (port->cached_edid) 4273 drm_edid = drm_edid_dup(port->cached_edid); 4274 else 4275 drm_edid = drm_edid_read_ddc(connector, &port->aux.ddc); 4276 4277 drm_dp_mst_topology_put_port(port); 4278 4279 return drm_edid; 4280 } 4281 EXPORT_SYMBOL(drm_dp_mst_edid_read); 4282 4283 /** 4284 * drm_dp_mst_get_edid() - get EDID for an MST port 4285 * @connector: toplevel connector to get EDID for 4286 * @mgr: manager for this port 4287 * @port: unverified pointer to a port. 4288 * 4289 * This function is deprecated; please use drm_dp_mst_edid_read() instead. 4290 * 4291 * This returns an EDID for the port connected to a connector, 4292 * It validates the pointer still exists so the caller doesn't require a 4293 * reference. 4294 */ 4295 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, 4296 struct drm_dp_mst_topology_mgr *mgr, 4297 struct drm_dp_mst_port *port) 4298 { 4299 const struct drm_edid *drm_edid; 4300 struct edid *edid; 4301 4302 drm_edid = drm_dp_mst_edid_read(connector, mgr, port); 4303 4304 edid = drm_edid_duplicate(drm_edid_raw(drm_edid)); 4305 4306 drm_edid_free(drm_edid); 4307 4308 return edid; 4309 } 4310 EXPORT_SYMBOL(drm_dp_mst_get_edid); 4311 4312 /** 4313 * drm_dp_atomic_find_time_slots() - Find and add time slots to the state 4314 * @state: global atomic state 4315 * @mgr: MST topology manager for the port 4316 * @port: port to find time slots for 4317 * @pbn: bandwidth required for the mode in PBN 4318 * 4319 * Allocates time slots to @port, replacing any previous time slot allocations it may 4320 * have had. Any atomic drivers which support MST must call this function in 4321 * their &drm_encoder_helper_funcs.atomic_check() callback unconditionally to 4322 * change the current time slot allocation for the new state, and ensure the MST 4323 * atomic state is added whenever the state of payloads in the topology changes. 4324 * 4325 * Allocations set by this function are not checked against the bandwidth 4326 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check(). 4327 * 4328 * Additionally, it is OK to call this function multiple times on the same 4329 * @port as needed. It is not OK however, to call this function and 4330 * drm_dp_atomic_release_time_slots() in the same atomic check phase. 4331 * 4332 * See also: 4333 * drm_dp_atomic_release_time_slots() 4334 * drm_dp_mst_atomic_check() 4335 * 4336 * Returns: 4337 * Total slots in the atomic state assigned for this port, or a negative error 4338 * code if the port no longer exists 4339 */ 4340 int drm_dp_atomic_find_time_slots(struct drm_atomic_state *state, 4341 struct drm_dp_mst_topology_mgr *mgr, 4342 struct drm_dp_mst_port *port, int pbn) 4343 { 4344 struct drm_dp_mst_topology_state *topology_state; 4345 struct drm_dp_mst_atomic_payload *payload = NULL; 4346 struct drm_connector_state *conn_state; 4347 int prev_slots = 0, prev_bw = 0, req_slots; 4348 4349 topology_state = drm_atomic_get_mst_topology_state(state, mgr); 4350 if (IS_ERR(topology_state)) 4351 return PTR_ERR(topology_state); 4352 4353 conn_state = drm_atomic_get_new_connector_state(state, port->connector); 4354 topology_state->pending_crtc_mask |= drm_crtc_mask(conn_state->crtc); 4355 4356 /* Find the current allocation for this port, if any */ 4357 payload = drm_atomic_get_mst_payload_state(topology_state, port); 4358 if (payload) { 4359 prev_slots = payload->time_slots; 4360 prev_bw = payload->pbn; 4361 4362 /* 4363 * This should never happen, unless the driver tries 4364 * releasing and allocating the same timeslot allocation, 4365 * which is an error 4366 */ 4367 if (drm_WARN_ON(mgr->dev, payload->delete)) { 4368 drm_err(mgr->dev, 4369 "cannot allocate and release time slots on [MST PORT:%p] in the same state\n", 4370 port); 4371 return -EINVAL; 4372 } 4373 } 4374 4375 req_slots = DIV_ROUND_UP(pbn, topology_state->pbn_div); 4376 4377 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] TU %d -> %d\n", 4378 port->connector->base.id, port->connector->name, 4379 port, prev_slots, req_slots); 4380 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n", 4381 port->connector->base.id, port->connector->name, 4382 port, prev_bw, pbn); 4383 4384 /* Add the new allocation to the state, note the VCPI isn't assigned until the end */ 4385 if (!payload) { 4386 payload = kzalloc(sizeof(*payload), GFP_KERNEL); 4387 if (!payload) 4388 return -ENOMEM; 4389 4390 drm_dp_mst_get_port_malloc(port); 4391 payload->port = port; 4392 payload->vc_start_slot = -1; 4393 list_add(&payload->next, &topology_state->payloads); 4394 } 4395 payload->time_slots = req_slots; 4396 payload->pbn = pbn; 4397 4398 return req_slots; 4399 } 4400 EXPORT_SYMBOL(drm_dp_atomic_find_time_slots); 4401 4402 /** 4403 * drm_dp_atomic_release_time_slots() - Release allocated time slots 4404 * @state: global atomic state 4405 * @mgr: MST topology manager for the port 4406 * @port: The port to release the time slots from 4407 * 4408 * Releases any time slots that have been allocated to a port in the atomic 4409 * state. Any atomic drivers which support MST must call this function 4410 * unconditionally in their &drm_connector_helper_funcs.atomic_check() callback. 4411 * This helper will check whether time slots would be released by the new state and 4412 * respond accordingly, along with ensuring the MST state is always added to the 4413 * atomic state whenever a new state would modify the state of payloads on the 4414 * topology. 4415 * 4416 * It is OK to call this even if @port has been removed from the system. 4417 * Additionally, it is OK to call this function multiple times on the same 4418 * @port as needed. It is not OK however, to call this function and 4419 * drm_dp_atomic_find_time_slots() on the same @port in a single atomic check 4420 * phase. 4421 * 4422 * See also: 4423 * drm_dp_atomic_find_time_slots() 4424 * drm_dp_mst_atomic_check() 4425 * 4426 * Returns: 4427 * 0 on success, negative error code otherwise 4428 */ 4429 int drm_dp_atomic_release_time_slots(struct drm_atomic_state *state, 4430 struct drm_dp_mst_topology_mgr *mgr, 4431 struct drm_dp_mst_port *port) 4432 { 4433 struct drm_dp_mst_topology_state *topology_state; 4434 struct drm_dp_mst_atomic_payload *payload; 4435 struct drm_connector_state *old_conn_state, *new_conn_state; 4436 bool update_payload = true; 4437 4438 old_conn_state = drm_atomic_get_old_connector_state(state, port->connector); 4439 if (!old_conn_state->crtc) 4440 return 0; 4441 4442 /* If the CRTC isn't disabled by this state, don't release it's payload */ 4443 new_conn_state = drm_atomic_get_new_connector_state(state, port->connector); 4444 if (new_conn_state->crtc) { 4445 struct drm_crtc_state *crtc_state = 4446 drm_atomic_get_new_crtc_state(state, new_conn_state->crtc); 4447 4448 /* No modeset means no payload changes, so it's safe to not pull in the MST state */ 4449 if (!crtc_state || !drm_atomic_crtc_needs_modeset(crtc_state)) 4450 return 0; 4451 4452 if (!crtc_state->mode_changed && !crtc_state->connectors_changed) 4453 update_payload = false; 4454 } 4455 4456 topology_state = drm_atomic_get_mst_topology_state(state, mgr); 4457 if (IS_ERR(topology_state)) 4458 return PTR_ERR(topology_state); 4459 4460 topology_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc); 4461 if (!update_payload) 4462 return 0; 4463 4464 payload = drm_atomic_get_mst_payload_state(topology_state, port); 4465 if (WARN_ON(!payload)) { 4466 drm_err(mgr->dev, "No payload for [MST PORT:%p] found in mst state %p\n", 4467 port, &topology_state->base); 4468 return -EINVAL; 4469 } 4470 4471 if (new_conn_state->crtc) 4472 return 0; 4473 4474 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] TU %d -> 0\n", port, payload->time_slots); 4475 if (!payload->delete) { 4476 payload->pbn = 0; 4477 payload->delete = true; 4478 topology_state->payload_mask &= ~BIT(payload->vcpi - 1); 4479 } 4480 4481 return 0; 4482 } 4483 EXPORT_SYMBOL(drm_dp_atomic_release_time_slots); 4484 4485 /** 4486 * drm_dp_mst_atomic_setup_commit() - setup_commit hook for MST helpers 4487 * @state: global atomic state 4488 * 4489 * This function saves all of the &drm_crtc_commit structs in an atomic state that touch any CRTCs 4490 * currently assigned to an MST topology. Drivers must call this hook from their 4491 * &drm_mode_config_helper_funcs.atomic_commit_setup hook. 4492 * 4493 * Returns: 4494 * 0 if all CRTC commits were retrieved successfully, negative error code otherwise 4495 */ 4496 int drm_dp_mst_atomic_setup_commit(struct drm_atomic_state *state) 4497 { 4498 struct drm_dp_mst_topology_mgr *mgr; 4499 struct drm_dp_mst_topology_state *mst_state; 4500 struct drm_crtc *crtc; 4501 struct drm_crtc_state *crtc_state; 4502 int i, j, commit_idx, num_commit_deps; 4503 4504 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { 4505 if (!mst_state->pending_crtc_mask) 4506 continue; 4507 4508 num_commit_deps = hweight32(mst_state->pending_crtc_mask); 4509 mst_state->commit_deps = kmalloc_array(num_commit_deps, 4510 sizeof(*mst_state->commit_deps), GFP_KERNEL); 4511 if (!mst_state->commit_deps) 4512 return -ENOMEM; 4513 mst_state->num_commit_deps = num_commit_deps; 4514 4515 commit_idx = 0; 4516 for_each_new_crtc_in_state(state, crtc, crtc_state, j) { 4517 if (mst_state->pending_crtc_mask & drm_crtc_mask(crtc)) { 4518 mst_state->commit_deps[commit_idx++] = 4519 drm_crtc_commit_get(crtc_state->commit); 4520 } 4521 } 4522 } 4523 4524 return 0; 4525 } 4526 EXPORT_SYMBOL(drm_dp_mst_atomic_setup_commit); 4527 4528 /** 4529 * drm_dp_mst_atomic_wait_for_dependencies() - Wait for all pending commits on MST topologies, 4530 * prepare new MST state for commit 4531 * @state: global atomic state 4532 * 4533 * Goes through any MST topologies in this atomic state, and waits for any pending commits which 4534 * touched CRTCs that were/are on an MST topology to be programmed to hardware and flipped to before 4535 * returning. This is to prevent multiple non-blocking commits affecting an MST topology from racing 4536 * with eachother by forcing them to be executed sequentially in situations where the only resources 4537 * the modeset objects in these commits share are an MST topology. 4538 * 4539 * This function also prepares the new MST state for commit by performing some state preparation 4540 * which can't be done until this point, such as reading back the final VC start slots (which are 4541 * determined at commit-time) from the previous state. 4542 * 4543 * All MST drivers must call this function after calling drm_atomic_helper_wait_for_dependencies(), 4544 * or whatever their equivalent of that is. 4545 */ 4546 void drm_dp_mst_atomic_wait_for_dependencies(struct drm_atomic_state *state) 4547 { 4548 struct drm_dp_mst_topology_state *old_mst_state, *new_mst_state; 4549 struct drm_dp_mst_topology_mgr *mgr; 4550 struct drm_dp_mst_atomic_payload *old_payload, *new_payload; 4551 int i, j, ret; 4552 4553 for_each_oldnew_mst_mgr_in_state(state, mgr, old_mst_state, new_mst_state, i) { 4554 for (j = 0; j < old_mst_state->num_commit_deps; j++) { 4555 ret = drm_crtc_commit_wait(old_mst_state->commit_deps[j]); 4556 if (ret < 0) 4557 drm_err(state->dev, "Failed to wait for %s: %d\n", 4558 old_mst_state->commit_deps[j]->crtc->name, ret); 4559 } 4560 4561 /* Now that previous state is committed, it's safe to copy over the start slot 4562 * assignments 4563 */ 4564 list_for_each_entry(old_payload, &old_mst_state->payloads, next) { 4565 if (old_payload->delete) 4566 continue; 4567 4568 new_payload = drm_atomic_get_mst_payload_state(new_mst_state, 4569 old_payload->port); 4570 new_payload->vc_start_slot = old_payload->vc_start_slot; 4571 } 4572 } 4573 } 4574 EXPORT_SYMBOL(drm_dp_mst_atomic_wait_for_dependencies); 4575 4576 /** 4577 * drm_dp_mst_root_conn_atomic_check() - Serialize CRTC commits on MST-capable connectors operating 4578 * in SST mode 4579 * @new_conn_state: The new connector state of the &drm_connector 4580 * @mgr: The MST topology manager for the &drm_connector 4581 * 4582 * Since MST uses fake &drm_encoder structs, the generic atomic modesetting code isn't able to 4583 * serialize non-blocking commits happening on the real DP connector of an MST topology switching 4584 * into/away from MST mode - as the CRTC on the real DP connector and the CRTCs on the connector's 4585 * MST topology will never share the same &drm_encoder. 4586 * 4587 * This function takes care of this serialization issue, by checking a root MST connector's atomic 4588 * state to determine if it is about to have a modeset - and then pulling in the MST topology state 4589 * if so, along with adding any relevant CRTCs to &drm_dp_mst_topology_state.pending_crtc_mask. 4590 * 4591 * Drivers implementing MST must call this function from the 4592 * &drm_connector_helper_funcs.atomic_check hook of any physical DP &drm_connector capable of 4593 * driving MST sinks. 4594 * 4595 * Returns: 4596 * 0 on success, negative error code otherwise 4597 */ 4598 int drm_dp_mst_root_conn_atomic_check(struct drm_connector_state *new_conn_state, 4599 struct drm_dp_mst_topology_mgr *mgr) 4600 { 4601 struct drm_atomic_state *state = new_conn_state->state; 4602 struct drm_connector_state *old_conn_state = 4603 drm_atomic_get_old_connector_state(state, new_conn_state->connector); 4604 struct drm_crtc_state *crtc_state; 4605 struct drm_dp_mst_topology_state *mst_state = NULL; 4606 4607 if (new_conn_state->crtc) { 4608 crtc_state = drm_atomic_get_new_crtc_state(state, new_conn_state->crtc); 4609 if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) { 4610 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 4611 if (IS_ERR(mst_state)) 4612 return PTR_ERR(mst_state); 4613 4614 mst_state->pending_crtc_mask |= drm_crtc_mask(new_conn_state->crtc); 4615 } 4616 } 4617 4618 if (old_conn_state->crtc) { 4619 crtc_state = drm_atomic_get_new_crtc_state(state, old_conn_state->crtc); 4620 if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) { 4621 if (!mst_state) { 4622 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 4623 if (IS_ERR(mst_state)) 4624 return PTR_ERR(mst_state); 4625 } 4626 4627 mst_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc); 4628 } 4629 } 4630 4631 return 0; 4632 } 4633 EXPORT_SYMBOL(drm_dp_mst_root_conn_atomic_check); 4634 4635 /** 4636 * drm_dp_mst_update_slots() - updates the slot info depending on the DP ecoding format 4637 * @mst_state: mst_state to update 4638 * @link_encoding_cap: the ecoding format on the link 4639 */ 4640 void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap) 4641 { 4642 if (link_encoding_cap == DP_CAP_ANSI_128B132B) { 4643 mst_state->total_avail_slots = 64; 4644 mst_state->start_slot = 0; 4645 } else { 4646 mst_state->total_avail_slots = 63; 4647 mst_state->start_slot = 1; 4648 } 4649 4650 DRM_DEBUG_KMS("%s encoding format on mst_state 0x%p\n", 4651 (link_encoding_cap == DP_CAP_ANSI_128B132B) ? "128b/132b":"8b/10b", 4652 mst_state); 4653 } 4654 EXPORT_SYMBOL(drm_dp_mst_update_slots); 4655 4656 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, 4657 int id, u8 start_slot, u8 num_slots) 4658 { 4659 u8 payload_alloc[3], status; 4660 int ret; 4661 int retries = 0; 4662 4663 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, 4664 DP_PAYLOAD_TABLE_UPDATED); 4665 4666 payload_alloc[0] = id; 4667 payload_alloc[1] = start_slot; 4668 payload_alloc[2] = num_slots; 4669 4670 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3); 4671 if (ret != 3) { 4672 drm_dbg_kms(mgr->dev, "failed to write payload allocation %d\n", ret); 4673 goto fail; 4674 } 4675 4676 retry: 4677 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 4678 if (ret < 0) { 4679 drm_dbg_kms(mgr->dev, "failed to read payload table status %d\n", ret); 4680 goto fail; 4681 } 4682 4683 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) { 4684 retries++; 4685 if (retries < 20) { 4686 usleep_range(10000, 20000); 4687 goto retry; 4688 } 4689 drm_dbg_kms(mgr->dev, "status not set after read payload table status %d\n", 4690 status); 4691 ret = -EINVAL; 4692 goto fail; 4693 } 4694 ret = 0; 4695 fail: 4696 return ret; 4697 } 4698 4699 static int do_get_act_status(struct drm_dp_aux *aux) 4700 { 4701 int ret; 4702 u8 status; 4703 4704 ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 4705 if (ret < 0) 4706 return ret; 4707 4708 return status; 4709 } 4710 4711 /** 4712 * drm_dp_check_act_status() - Polls for ACT handled status. 4713 * @mgr: manager to use 4714 * 4715 * Tries waiting for the MST hub to finish updating it's payload table by 4716 * polling for the ACT handled bit for up to 3 seconds (yes-some hubs really 4717 * take that long). 4718 * 4719 * Returns: 4720 * 0 if the ACT was handled in time, negative error code on failure. 4721 */ 4722 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr) 4723 { 4724 /* 4725 * There doesn't seem to be any recommended retry count or timeout in 4726 * the MST specification. Since some hubs have been observed to take 4727 * over 1 second to update their payload allocations under certain 4728 * conditions, we use a rather large timeout value. 4729 */ 4730 const int timeout_ms = 3000; 4731 int ret, status; 4732 4733 ret = readx_poll_timeout(do_get_act_status, mgr->aux, status, 4734 status & DP_PAYLOAD_ACT_HANDLED || status < 0, 4735 200, timeout_ms * USEC_PER_MSEC); 4736 if (ret < 0 && status >= 0) { 4737 drm_err(mgr->dev, "Failed to get ACT after %dms, last status: %02x\n", 4738 timeout_ms, status); 4739 return -EINVAL; 4740 } else if (status < 0) { 4741 /* 4742 * Failure here isn't unexpected - the hub may have 4743 * just been unplugged 4744 */ 4745 drm_dbg_kms(mgr->dev, "Failed to read payload table status: %d\n", status); 4746 return status; 4747 } 4748 4749 return 0; 4750 } 4751 EXPORT_SYMBOL(drm_dp_check_act_status); 4752 4753 /** 4754 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode. 4755 * @clock: dot clock 4756 * @bpp: bpp as .4 binary fixed point 4757 * 4758 * This uses the formula in the spec to calculate the PBN value for a mode. 4759 */ 4760 int drm_dp_calc_pbn_mode(int clock, int bpp) 4761 { 4762 /* 4763 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006 4764 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on 4765 * common multiplier to render an integer PBN for all link rate/lane 4766 * counts combinations 4767 * calculate 4768 * peak_kbps *= (1006/1000) 4769 * peak_kbps *= (64/54) 4770 * peak_kbps *= 8 convert to bytes 4771 */ 4772 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006 >> 4), 4773 1000 * 8 * 54 * 1000); 4774 } 4775 EXPORT_SYMBOL(drm_dp_calc_pbn_mode); 4776 4777 /* we want to kick the TX after we've ack the up/down IRQs. */ 4778 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr) 4779 { 4780 queue_work(system_long_wq, &mgr->tx_work); 4781 } 4782 4783 /* 4784 * Helper function for parsing DP device types into convenient strings 4785 * for use with dp_mst_topology 4786 */ 4787 static const char *pdt_to_string(u8 pdt) 4788 { 4789 switch (pdt) { 4790 case DP_PEER_DEVICE_NONE: 4791 return "NONE"; 4792 case DP_PEER_DEVICE_SOURCE_OR_SST: 4793 return "SOURCE OR SST"; 4794 case DP_PEER_DEVICE_MST_BRANCHING: 4795 return "MST BRANCHING"; 4796 case DP_PEER_DEVICE_SST_SINK: 4797 return "SST SINK"; 4798 case DP_PEER_DEVICE_DP_LEGACY_CONV: 4799 return "DP LEGACY CONV"; 4800 default: 4801 return "ERR"; 4802 } 4803 } 4804 4805 static void drm_dp_mst_dump_mstb(struct seq_file *m, 4806 struct drm_dp_mst_branch *mstb) 4807 { 4808 struct drm_dp_mst_port *port; 4809 int tabs = mstb->lct; 4810 char prefix[10]; 4811 int i; 4812 4813 for (i = 0; i < tabs; i++) 4814 prefix[i] = '\t'; 4815 prefix[i] = '\0'; 4816 4817 seq_printf(m, "%smstb - [%p]: num_ports: %d\n", prefix, mstb, mstb->num_ports); 4818 list_for_each_entry(port, &mstb->ports, next) { 4819 seq_printf(m, "%sport %d - [%p] (%s - %s): ddps: %d, ldps: %d, sdp: %d/%d, fec: %s, conn: %p\n", 4820 prefix, 4821 port->port_num, 4822 port, 4823 port->input ? "input" : "output", 4824 pdt_to_string(port->pdt), 4825 port->ddps, 4826 port->ldps, 4827 port->num_sdp_streams, 4828 port->num_sdp_stream_sinks, 4829 port->fec_capable ? "true" : "false", 4830 port->connector); 4831 if (port->mstb) 4832 drm_dp_mst_dump_mstb(m, port->mstb); 4833 } 4834 } 4835 4836 #define DP_PAYLOAD_TABLE_SIZE 64 4837 4838 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, 4839 char *buf) 4840 { 4841 int i; 4842 4843 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) { 4844 if (drm_dp_dpcd_read(mgr->aux, 4845 DP_PAYLOAD_TABLE_UPDATE_STATUS + i, 4846 &buf[i], 16) != 16) 4847 return false; 4848 } 4849 return true; 4850 } 4851 4852 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr, 4853 struct drm_dp_mst_port *port, char *name, 4854 int namelen) 4855 { 4856 struct edid *mst_edid; 4857 4858 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port); 4859 drm_edid_get_monitor_name(mst_edid, name, namelen); 4860 kfree(mst_edid); 4861 } 4862 4863 /** 4864 * drm_dp_mst_dump_topology(): dump topology to seq file. 4865 * @m: seq_file to dump output to 4866 * @mgr: manager to dump current topology for. 4867 * 4868 * helper to dump MST topology to a seq file for debugfs. 4869 */ 4870 void drm_dp_mst_dump_topology(struct seq_file *m, 4871 struct drm_dp_mst_topology_mgr *mgr) 4872 { 4873 struct drm_dp_mst_topology_state *state; 4874 struct drm_dp_mst_atomic_payload *payload; 4875 int i, ret; 4876 4877 mutex_lock(&mgr->lock); 4878 if (mgr->mst_primary) 4879 drm_dp_mst_dump_mstb(m, mgr->mst_primary); 4880 4881 /* dump VCPIs */ 4882 mutex_unlock(&mgr->lock); 4883 4884 ret = drm_modeset_lock_single_interruptible(&mgr->base.lock); 4885 if (ret < 0) 4886 return; 4887 4888 state = to_drm_dp_mst_topology_state(mgr->base.state); 4889 seq_printf(m, "\n*** Atomic state info ***\n"); 4890 seq_printf(m, "payload_mask: %x, max_payloads: %d, start_slot: %u, pbn_div: %d\n", 4891 state->payload_mask, mgr->max_payloads, state->start_slot, state->pbn_div); 4892 4893 seq_printf(m, "\n| idx | port | vcpi | slots | pbn | dsc | sink name |\n"); 4894 for (i = 0; i < mgr->max_payloads; i++) { 4895 list_for_each_entry(payload, &state->payloads, next) { 4896 char name[14]; 4897 4898 if (payload->vcpi != i || payload->delete) 4899 continue; 4900 4901 fetch_monitor_name(mgr, payload->port, name, sizeof(name)); 4902 seq_printf(m, " %5d %6d %6d %02d - %02d %5d %5s %19s\n", 4903 i, 4904 payload->port->port_num, 4905 payload->vcpi, 4906 payload->vc_start_slot, 4907 payload->vc_start_slot + payload->time_slots - 1, 4908 payload->pbn, 4909 payload->dsc_enabled ? "Y" : "N", 4910 (*name != 0) ? name : "Unknown"); 4911 } 4912 } 4913 4914 seq_printf(m, "\n*** DPCD Info ***\n"); 4915 mutex_lock(&mgr->lock); 4916 if (mgr->mst_primary) { 4917 u8 buf[DP_PAYLOAD_TABLE_SIZE]; 4918 int ret; 4919 4920 if (drm_dp_read_dpcd_caps(mgr->aux, buf) < 0) { 4921 seq_printf(m, "dpcd read failed\n"); 4922 goto out; 4923 } 4924 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf); 4925 4926 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2); 4927 if (ret != 2) { 4928 seq_printf(m, "faux/mst read failed\n"); 4929 goto out; 4930 } 4931 seq_printf(m, "faux/mst: %*ph\n", 2, buf); 4932 4933 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1); 4934 if (ret != 1) { 4935 seq_printf(m, "mst ctrl read failed\n"); 4936 goto out; 4937 } 4938 seq_printf(m, "mst ctrl: %*ph\n", 1, buf); 4939 4940 /* dump the standard OUI branch header */ 4941 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE); 4942 if (ret != DP_BRANCH_OUI_HEADER_SIZE) { 4943 seq_printf(m, "branch oui read failed\n"); 4944 goto out; 4945 } 4946 seq_printf(m, "branch oui: %*phN devid: ", 3, buf); 4947 4948 for (i = 0x3; i < 0x8 && buf[i]; i++) 4949 seq_printf(m, "%c", buf[i]); 4950 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n", 4951 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]); 4952 if (dump_dp_payload_table(mgr, buf)) 4953 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf); 4954 } 4955 4956 out: 4957 mutex_unlock(&mgr->lock); 4958 drm_modeset_unlock(&mgr->base.lock); 4959 } 4960 EXPORT_SYMBOL(drm_dp_mst_dump_topology); 4961 4962 static void drm_dp_tx_work(struct work_struct *work) 4963 { 4964 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work); 4965 4966 mutex_lock(&mgr->qlock); 4967 if (!list_empty(&mgr->tx_msg_downq)) 4968 process_single_down_tx_qlock(mgr); 4969 mutex_unlock(&mgr->qlock); 4970 } 4971 4972 static inline void 4973 drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port) 4974 { 4975 drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs); 4976 4977 if (port->connector) { 4978 drm_connector_unregister(port->connector); 4979 drm_connector_put(port->connector); 4980 } 4981 4982 drm_dp_mst_put_port_malloc(port); 4983 } 4984 4985 static inline void 4986 drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb) 4987 { 4988 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 4989 struct drm_dp_mst_port *port, *port_tmp; 4990 struct drm_dp_sideband_msg_tx *txmsg, *txmsg_tmp; 4991 bool wake_tx = false; 4992 4993 mutex_lock(&mgr->lock); 4994 list_for_each_entry_safe(port, port_tmp, &mstb->ports, next) { 4995 list_del(&port->next); 4996 drm_dp_mst_topology_put_port(port); 4997 } 4998 mutex_unlock(&mgr->lock); 4999 5000 /* drop any tx slot msg */ 5001 mutex_lock(&mstb->mgr->qlock); 5002 list_for_each_entry_safe(txmsg, txmsg_tmp, &mgr->tx_msg_downq, next) { 5003 if (txmsg->dst != mstb) 5004 continue; 5005 5006 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 5007 list_del(&txmsg->next); 5008 wake_tx = true; 5009 } 5010 mutex_unlock(&mstb->mgr->qlock); 5011 5012 if (wake_tx) 5013 wake_up_all(&mstb->mgr->tx_waitq); 5014 5015 drm_dp_mst_put_mstb_malloc(mstb); 5016 } 5017 5018 static void drm_dp_delayed_destroy_work(struct work_struct *work) 5019 { 5020 struct drm_dp_mst_topology_mgr *mgr = 5021 container_of(work, struct drm_dp_mst_topology_mgr, 5022 delayed_destroy_work); 5023 bool send_hotplug = false, go_again; 5024 5025 /* 5026 * Not a regular list traverse as we have to drop the destroy 5027 * connector lock before destroying the mstb/port, to avoid AB->BA 5028 * ordering between this lock and the config mutex. 5029 */ 5030 do { 5031 go_again = false; 5032 5033 for (;;) { 5034 struct drm_dp_mst_branch *mstb; 5035 5036 mutex_lock(&mgr->delayed_destroy_lock); 5037 mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list, 5038 struct drm_dp_mst_branch, 5039 destroy_next); 5040 if (mstb) 5041 list_del(&mstb->destroy_next); 5042 mutex_unlock(&mgr->delayed_destroy_lock); 5043 5044 if (!mstb) 5045 break; 5046 5047 drm_dp_delayed_destroy_mstb(mstb); 5048 go_again = true; 5049 } 5050 5051 for (;;) { 5052 struct drm_dp_mst_port *port; 5053 5054 mutex_lock(&mgr->delayed_destroy_lock); 5055 port = list_first_entry_or_null(&mgr->destroy_port_list, 5056 struct drm_dp_mst_port, 5057 next); 5058 if (port) 5059 list_del(&port->next); 5060 mutex_unlock(&mgr->delayed_destroy_lock); 5061 5062 if (!port) 5063 break; 5064 5065 drm_dp_delayed_destroy_port(port); 5066 send_hotplug = true; 5067 go_again = true; 5068 } 5069 } while (go_again); 5070 5071 if (send_hotplug) 5072 drm_kms_helper_hotplug_event(mgr->dev); 5073 } 5074 5075 static struct drm_private_state * 5076 drm_dp_mst_duplicate_state(struct drm_private_obj *obj) 5077 { 5078 struct drm_dp_mst_topology_state *state, *old_state = 5079 to_dp_mst_topology_state(obj->state); 5080 struct drm_dp_mst_atomic_payload *pos, *payload; 5081 5082 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL); 5083 if (!state) 5084 return NULL; 5085 5086 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base); 5087 5088 INIT_LIST_HEAD(&state->payloads); 5089 state->commit_deps = NULL; 5090 state->num_commit_deps = 0; 5091 state->pending_crtc_mask = 0; 5092 5093 list_for_each_entry(pos, &old_state->payloads, next) { 5094 /* Prune leftover freed timeslot allocations */ 5095 if (pos->delete) 5096 continue; 5097 5098 payload = kmemdup(pos, sizeof(*payload), GFP_KERNEL); 5099 if (!payload) 5100 goto fail; 5101 5102 drm_dp_mst_get_port_malloc(payload->port); 5103 list_add(&payload->next, &state->payloads); 5104 } 5105 5106 return &state->base; 5107 5108 fail: 5109 list_for_each_entry_safe(pos, payload, &state->payloads, next) { 5110 drm_dp_mst_put_port_malloc(pos->port); 5111 kfree(pos); 5112 } 5113 kfree(state); 5114 5115 return NULL; 5116 } 5117 5118 static void drm_dp_mst_destroy_state(struct drm_private_obj *obj, 5119 struct drm_private_state *state) 5120 { 5121 struct drm_dp_mst_topology_state *mst_state = 5122 to_dp_mst_topology_state(state); 5123 struct drm_dp_mst_atomic_payload *pos, *tmp; 5124 int i; 5125 5126 list_for_each_entry_safe(pos, tmp, &mst_state->payloads, next) { 5127 /* We only keep references to ports with active payloads */ 5128 if (!pos->delete) 5129 drm_dp_mst_put_port_malloc(pos->port); 5130 kfree(pos); 5131 } 5132 5133 for (i = 0; i < mst_state->num_commit_deps; i++) 5134 drm_crtc_commit_put(mst_state->commit_deps[i]); 5135 5136 kfree(mst_state->commit_deps); 5137 kfree(mst_state); 5138 } 5139 5140 static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port, 5141 struct drm_dp_mst_branch *branch) 5142 { 5143 while (port->parent) { 5144 if (port->parent == branch) 5145 return true; 5146 5147 if (port->parent->port_parent) 5148 port = port->parent->port_parent; 5149 else 5150 break; 5151 } 5152 return false; 5153 } 5154 5155 static int 5156 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, 5157 struct drm_dp_mst_topology_state *state); 5158 5159 static int 5160 drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb, 5161 struct drm_dp_mst_topology_state *state) 5162 { 5163 struct drm_dp_mst_atomic_payload *payload; 5164 struct drm_dp_mst_port *port; 5165 int pbn_used = 0, ret; 5166 bool found = false; 5167 5168 /* Check that we have at least one port in our state that's downstream 5169 * of this branch, otherwise we can skip this branch 5170 */ 5171 list_for_each_entry(payload, &state->payloads, next) { 5172 if (!payload->pbn || 5173 !drm_dp_mst_port_downstream_of_branch(payload->port, mstb)) 5174 continue; 5175 5176 found = true; 5177 break; 5178 } 5179 if (!found) 5180 return 0; 5181 5182 if (mstb->port_parent) 5183 drm_dbg_atomic(mstb->mgr->dev, 5184 "[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n", 5185 mstb->port_parent->parent, mstb->port_parent, mstb); 5186 else 5187 drm_dbg_atomic(mstb->mgr->dev, "[MSTB:%p] Checking bandwidth limits\n", mstb); 5188 5189 list_for_each_entry(port, &mstb->ports, next) { 5190 ret = drm_dp_mst_atomic_check_port_bw_limit(port, state); 5191 if (ret < 0) 5192 return ret; 5193 5194 pbn_used += ret; 5195 } 5196 5197 return pbn_used; 5198 } 5199 5200 static int 5201 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, 5202 struct drm_dp_mst_topology_state *state) 5203 { 5204 struct drm_dp_mst_atomic_payload *payload; 5205 int pbn_used = 0; 5206 5207 if (port->pdt == DP_PEER_DEVICE_NONE) 5208 return 0; 5209 5210 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { 5211 payload = drm_atomic_get_mst_payload_state(state, port); 5212 if (!payload) 5213 return 0; 5214 5215 /* 5216 * This could happen if the sink deasserted its HPD line, but 5217 * the branch device still reports it as attached (PDT != NONE). 5218 */ 5219 if (!port->full_pbn) { 5220 drm_dbg_atomic(port->mgr->dev, 5221 "[MSTB:%p] [MST PORT:%p] no BW available for the port\n", 5222 port->parent, port); 5223 return -EINVAL; 5224 } 5225 5226 pbn_used = payload->pbn; 5227 } else { 5228 pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb, 5229 state); 5230 if (pbn_used <= 0) 5231 return pbn_used; 5232 } 5233 5234 if (pbn_used > port->full_pbn) { 5235 drm_dbg_atomic(port->mgr->dev, 5236 "[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n", 5237 port->parent, port, pbn_used, port->full_pbn); 5238 return -ENOSPC; 5239 } 5240 5241 drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n", 5242 port->parent, port, pbn_used, port->full_pbn); 5243 5244 return pbn_used; 5245 } 5246 5247 static inline int 5248 drm_dp_mst_atomic_check_payload_alloc_limits(struct drm_dp_mst_topology_mgr *mgr, 5249 struct drm_dp_mst_topology_state *mst_state) 5250 { 5251 struct drm_dp_mst_atomic_payload *payload; 5252 int avail_slots = mst_state->total_avail_slots, payload_count = 0; 5253 5254 list_for_each_entry(payload, &mst_state->payloads, next) { 5255 /* Releasing payloads is always OK-even if the port is gone */ 5256 if (payload->delete) { 5257 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] releases all time slots\n", 5258 payload->port); 5259 continue; 5260 } 5261 5262 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] requires %d time slots\n", 5263 payload->port, payload->time_slots); 5264 5265 avail_slots -= payload->time_slots; 5266 if (avail_slots < 0) { 5267 drm_dbg_atomic(mgr->dev, 5268 "[MST PORT:%p] not enough time slots in mst state %p (avail=%d)\n", 5269 payload->port, mst_state, avail_slots + payload->time_slots); 5270 return -ENOSPC; 5271 } 5272 5273 if (++payload_count > mgr->max_payloads) { 5274 drm_dbg_atomic(mgr->dev, 5275 "[MST MGR:%p] state %p has too many payloads (max=%d)\n", 5276 mgr, mst_state, mgr->max_payloads); 5277 return -EINVAL; 5278 } 5279 5280 /* Assign a VCPI */ 5281 if (!payload->vcpi) { 5282 payload->vcpi = ffz(mst_state->payload_mask) + 1; 5283 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] assigned VCPI #%d\n", 5284 payload->port, payload->vcpi); 5285 mst_state->payload_mask |= BIT(payload->vcpi - 1); 5286 } 5287 } 5288 5289 if (!payload_count) 5290 mst_state->pbn_div = 0; 5291 5292 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] mst state %p TU pbn_div=%d avail=%d used=%d\n", 5293 mgr, mst_state, mst_state->pbn_div, avail_slots, 5294 mst_state->total_avail_slots - avail_slots); 5295 5296 return 0; 5297 } 5298 5299 /** 5300 * drm_dp_mst_add_affected_dsc_crtcs 5301 * @state: Pointer to the new struct drm_dp_mst_topology_state 5302 * @mgr: MST topology manager 5303 * 5304 * Whenever there is a change in mst topology 5305 * DSC configuration would have to be recalculated 5306 * therefore we need to trigger modeset on all affected 5307 * CRTCs in that topology 5308 * 5309 * See also: 5310 * drm_dp_mst_atomic_enable_dsc() 5311 */ 5312 int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr) 5313 { 5314 struct drm_dp_mst_topology_state *mst_state; 5315 struct drm_dp_mst_atomic_payload *pos; 5316 struct drm_connector *connector; 5317 struct drm_connector_state *conn_state; 5318 struct drm_crtc *crtc; 5319 struct drm_crtc_state *crtc_state; 5320 5321 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 5322 5323 if (IS_ERR(mst_state)) 5324 return PTR_ERR(mst_state); 5325 5326 list_for_each_entry(pos, &mst_state->payloads, next) { 5327 5328 connector = pos->port->connector; 5329 5330 if (!connector) 5331 return -EINVAL; 5332 5333 conn_state = drm_atomic_get_connector_state(state, connector); 5334 5335 if (IS_ERR(conn_state)) 5336 return PTR_ERR(conn_state); 5337 5338 crtc = conn_state->crtc; 5339 5340 if (!crtc) 5341 continue; 5342 5343 if (!drm_dp_mst_dsc_aux_for_port(pos->port)) 5344 continue; 5345 5346 crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc); 5347 5348 if (IS_ERR(crtc_state)) 5349 return PTR_ERR(crtc_state); 5350 5351 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] Setting mode_changed flag on CRTC %p\n", 5352 mgr, crtc); 5353 5354 crtc_state->mode_changed = true; 5355 } 5356 return 0; 5357 } 5358 EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs); 5359 5360 /** 5361 * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off 5362 * @state: Pointer to the new drm_atomic_state 5363 * @port: Pointer to the affected MST Port 5364 * @pbn: Newly recalculated bw required for link with DSC enabled 5365 * @enable: Boolean flag to enable or disable DSC on the port 5366 * 5367 * This function enables DSC on the given Port 5368 * by recalculating its vcpi from pbn provided 5369 * and sets dsc_enable flag to keep track of which 5370 * ports have DSC enabled 5371 * 5372 */ 5373 int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state, 5374 struct drm_dp_mst_port *port, 5375 int pbn, bool enable) 5376 { 5377 struct drm_dp_mst_topology_state *mst_state; 5378 struct drm_dp_mst_atomic_payload *payload; 5379 int time_slots = 0; 5380 5381 mst_state = drm_atomic_get_mst_topology_state(state, port->mgr); 5382 if (IS_ERR(mst_state)) 5383 return PTR_ERR(mst_state); 5384 5385 payload = drm_atomic_get_mst_payload_state(mst_state, port); 5386 if (!payload) { 5387 drm_dbg_atomic(state->dev, 5388 "[MST PORT:%p] Couldn't find payload in mst state %p\n", 5389 port, mst_state); 5390 return -EINVAL; 5391 } 5392 5393 if (payload->dsc_enabled == enable) { 5394 drm_dbg_atomic(state->dev, 5395 "[MST PORT:%p] DSC flag is already set to %d, returning %d time slots\n", 5396 port, enable, payload->time_slots); 5397 time_slots = payload->time_slots; 5398 } 5399 5400 if (enable) { 5401 time_slots = drm_dp_atomic_find_time_slots(state, port->mgr, port, pbn); 5402 drm_dbg_atomic(state->dev, 5403 "[MST PORT:%p] Enabling DSC flag, reallocating %d time slots on the port\n", 5404 port, time_slots); 5405 if (time_slots < 0) 5406 return -EINVAL; 5407 } 5408 5409 payload->dsc_enabled = enable; 5410 5411 return time_slots; 5412 } 5413 EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc); 5414 5415 /** 5416 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an 5417 * atomic update is valid 5418 * @state: Pointer to the new &struct drm_dp_mst_topology_state 5419 * 5420 * Checks the given topology state for an atomic update to ensure that it's 5421 * valid. This includes checking whether there's enough bandwidth to support 5422 * the new timeslot allocations in the atomic update. 5423 * 5424 * Any atomic drivers supporting DP MST must make sure to call this after 5425 * checking the rest of their state in their 5426 * &drm_mode_config_funcs.atomic_check() callback. 5427 * 5428 * See also: 5429 * drm_dp_atomic_find_time_slots() 5430 * drm_dp_atomic_release_time_slots() 5431 * 5432 * Returns: 5433 * 5434 * 0 if the new state is valid, negative error code otherwise. 5435 */ 5436 int drm_dp_mst_atomic_check(struct drm_atomic_state *state) 5437 { 5438 struct drm_dp_mst_topology_mgr *mgr; 5439 struct drm_dp_mst_topology_state *mst_state; 5440 int i, ret = 0; 5441 5442 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { 5443 if (!mgr->mst_state) 5444 continue; 5445 5446 ret = drm_dp_mst_atomic_check_payload_alloc_limits(mgr, mst_state); 5447 if (ret) 5448 break; 5449 5450 mutex_lock(&mgr->lock); 5451 ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary, 5452 mst_state); 5453 mutex_unlock(&mgr->lock); 5454 if (ret < 0) 5455 break; 5456 else 5457 ret = 0; 5458 } 5459 5460 return ret; 5461 } 5462 EXPORT_SYMBOL(drm_dp_mst_atomic_check); 5463 5464 const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = { 5465 .atomic_duplicate_state = drm_dp_mst_duplicate_state, 5466 .atomic_destroy_state = drm_dp_mst_destroy_state, 5467 }; 5468 EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs); 5469 5470 /** 5471 * drm_atomic_get_mst_topology_state: get MST topology state 5472 * @state: global atomic state 5473 * @mgr: MST topology manager, also the private object in this case 5474 * 5475 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic 5476 * state vtable so that the private object state returned is that of a MST 5477 * topology object. 5478 * 5479 * RETURNS: 5480 * 5481 * The MST topology state or error pointer. 5482 */ 5483 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state, 5484 struct drm_dp_mst_topology_mgr *mgr) 5485 { 5486 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base)); 5487 } 5488 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state); 5489 5490 /** 5491 * drm_atomic_get_old_mst_topology_state: get old MST topology state in atomic state, if any 5492 * @state: global atomic state 5493 * @mgr: MST topology manager, also the private object in this case 5494 * 5495 * This function wraps drm_atomic_get_old_private_obj_state() passing in the MST atomic 5496 * state vtable so that the private object state returned is that of a MST 5497 * topology object. 5498 * 5499 * Returns: 5500 * 5501 * The old MST topology state, or NULL if there's no topology state for this MST mgr 5502 * in the global atomic state 5503 */ 5504 struct drm_dp_mst_topology_state * 5505 drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state, 5506 struct drm_dp_mst_topology_mgr *mgr) 5507 { 5508 struct drm_private_state *old_priv_state = 5509 drm_atomic_get_old_private_obj_state(state, &mgr->base); 5510 5511 return old_priv_state ? to_dp_mst_topology_state(old_priv_state) : NULL; 5512 } 5513 EXPORT_SYMBOL(drm_atomic_get_old_mst_topology_state); 5514 5515 /** 5516 * drm_atomic_get_new_mst_topology_state: get new MST topology state in atomic state, if any 5517 * @state: global atomic state 5518 * @mgr: MST topology manager, also the private object in this case 5519 * 5520 * This function wraps drm_atomic_get_new_private_obj_state() passing in the MST atomic 5521 * state vtable so that the private object state returned is that of a MST 5522 * topology object. 5523 * 5524 * Returns: 5525 * 5526 * The new MST topology state, or NULL if there's no topology state for this MST mgr 5527 * in the global atomic state 5528 */ 5529 struct drm_dp_mst_topology_state * 5530 drm_atomic_get_new_mst_topology_state(struct drm_atomic_state *state, 5531 struct drm_dp_mst_topology_mgr *mgr) 5532 { 5533 struct drm_private_state *new_priv_state = 5534 drm_atomic_get_new_private_obj_state(state, &mgr->base); 5535 5536 return new_priv_state ? to_dp_mst_topology_state(new_priv_state) : NULL; 5537 } 5538 EXPORT_SYMBOL(drm_atomic_get_new_mst_topology_state); 5539 5540 /** 5541 * drm_dp_mst_topology_mgr_init - initialise a topology manager 5542 * @mgr: manager struct to initialise 5543 * @dev: device providing this structure - for i2c addition. 5544 * @aux: DP helper aux channel to talk to this device 5545 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit 5546 * @max_payloads: maximum number of payloads this GPU can source 5547 * @conn_base_id: the connector object ID the MST device is connected to. 5548 * 5549 * Return 0 for success, or negative error code on failure 5550 */ 5551 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, 5552 struct drm_device *dev, struct drm_dp_aux *aux, 5553 int max_dpcd_transaction_bytes, int max_payloads, 5554 int conn_base_id) 5555 { 5556 struct drm_dp_mst_topology_state *mst_state; 5557 5558 mutex_init(&mgr->lock); 5559 mutex_init(&mgr->qlock); 5560 mutex_init(&mgr->delayed_destroy_lock); 5561 mutex_init(&mgr->up_req_lock); 5562 mutex_init(&mgr->probe_lock); 5563 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 5564 mutex_init(&mgr->topology_ref_history_lock); 5565 stack_depot_init(); 5566 #endif 5567 INIT_LIST_HEAD(&mgr->tx_msg_downq); 5568 INIT_LIST_HEAD(&mgr->destroy_port_list); 5569 INIT_LIST_HEAD(&mgr->destroy_branch_device_list); 5570 INIT_LIST_HEAD(&mgr->up_req_list); 5571 5572 /* 5573 * delayed_destroy_work will be queued on a dedicated WQ, so that any 5574 * requeuing will be also flushed when deiniting the topology manager. 5575 */ 5576 mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0); 5577 if (mgr->delayed_destroy_wq == NULL) 5578 return -ENOMEM; 5579 5580 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work); 5581 INIT_WORK(&mgr->tx_work, drm_dp_tx_work); 5582 INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work); 5583 INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work); 5584 init_waitqueue_head(&mgr->tx_waitq); 5585 mgr->dev = dev; 5586 mgr->aux = aux; 5587 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes; 5588 mgr->max_payloads = max_payloads; 5589 mgr->conn_base_id = conn_base_id; 5590 5591 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL); 5592 if (mst_state == NULL) 5593 return -ENOMEM; 5594 5595 mst_state->total_avail_slots = 63; 5596 mst_state->start_slot = 1; 5597 5598 mst_state->mgr = mgr; 5599 INIT_LIST_HEAD(&mst_state->payloads); 5600 5601 drm_atomic_private_obj_init(dev, &mgr->base, 5602 &mst_state->base, 5603 &drm_dp_mst_topology_state_funcs); 5604 5605 return 0; 5606 } 5607 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init); 5608 5609 /** 5610 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager. 5611 * @mgr: manager to destroy 5612 */ 5613 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr) 5614 { 5615 drm_dp_mst_topology_mgr_set_mst(mgr, false); 5616 flush_work(&mgr->work); 5617 /* The following will also drain any requeued work on the WQ. */ 5618 if (mgr->delayed_destroy_wq) { 5619 destroy_workqueue(mgr->delayed_destroy_wq); 5620 mgr->delayed_destroy_wq = NULL; 5621 } 5622 mgr->dev = NULL; 5623 mgr->aux = NULL; 5624 drm_atomic_private_obj_fini(&mgr->base); 5625 mgr->funcs = NULL; 5626 5627 mutex_destroy(&mgr->delayed_destroy_lock); 5628 mutex_destroy(&mgr->qlock); 5629 mutex_destroy(&mgr->lock); 5630 mutex_destroy(&mgr->up_req_lock); 5631 mutex_destroy(&mgr->probe_lock); 5632 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 5633 mutex_destroy(&mgr->topology_ref_history_lock); 5634 #endif 5635 } 5636 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy); 5637 5638 static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num) 5639 { 5640 int i; 5641 5642 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS) 5643 return false; 5644 5645 for (i = 0; i < num - 1; i++) { 5646 if (msgs[i].flags & I2C_M_RD || 5647 msgs[i].len > 0xff) 5648 return false; 5649 } 5650 5651 return msgs[num - 1].flags & I2C_M_RD && 5652 msgs[num - 1].len <= 0xff; 5653 } 5654 5655 static bool remote_i2c_write_ok(const struct i2c_msg msgs[], int num) 5656 { 5657 int i; 5658 5659 for (i = 0; i < num - 1; i++) { 5660 if (msgs[i].flags & I2C_M_RD || !(msgs[i].flags & I2C_M_STOP) || 5661 msgs[i].len > 0xff) 5662 return false; 5663 } 5664 5665 return !(msgs[num - 1].flags & I2C_M_RD) && msgs[num - 1].len <= 0xff; 5666 } 5667 5668 static int drm_dp_mst_i2c_read(struct drm_dp_mst_branch *mstb, 5669 struct drm_dp_mst_port *port, 5670 struct i2c_msg *msgs, int num) 5671 { 5672 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5673 unsigned int i; 5674 struct drm_dp_sideband_msg_req_body msg; 5675 struct drm_dp_sideband_msg_tx *txmsg = NULL; 5676 int ret; 5677 5678 memset(&msg, 0, sizeof(msg)); 5679 msg.req_type = DP_REMOTE_I2C_READ; 5680 msg.u.i2c_read.num_transactions = num - 1; 5681 msg.u.i2c_read.port_number = port->port_num; 5682 for (i = 0; i < num - 1; i++) { 5683 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr; 5684 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len; 5685 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf; 5686 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP); 5687 } 5688 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr; 5689 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len; 5690 5691 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 5692 if (!txmsg) { 5693 ret = -ENOMEM; 5694 goto out; 5695 } 5696 5697 txmsg->dst = mstb; 5698 drm_dp_encode_sideband_req(&msg, txmsg); 5699 5700 drm_dp_queue_down_tx(mgr, txmsg); 5701 5702 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 5703 if (ret > 0) { 5704 5705 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 5706 ret = -EREMOTEIO; 5707 goto out; 5708 } 5709 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) { 5710 ret = -EIO; 5711 goto out; 5712 } 5713 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len); 5714 ret = num; 5715 } 5716 out: 5717 kfree(txmsg); 5718 return ret; 5719 } 5720 5721 static int drm_dp_mst_i2c_write(struct drm_dp_mst_branch *mstb, 5722 struct drm_dp_mst_port *port, 5723 struct i2c_msg *msgs, int num) 5724 { 5725 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5726 unsigned int i; 5727 struct drm_dp_sideband_msg_req_body msg; 5728 struct drm_dp_sideband_msg_tx *txmsg = NULL; 5729 int ret; 5730 5731 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 5732 if (!txmsg) { 5733 ret = -ENOMEM; 5734 goto out; 5735 } 5736 for (i = 0; i < num; i++) { 5737 memset(&msg, 0, sizeof(msg)); 5738 msg.req_type = DP_REMOTE_I2C_WRITE; 5739 msg.u.i2c_write.port_number = port->port_num; 5740 msg.u.i2c_write.write_i2c_device_id = msgs[i].addr; 5741 msg.u.i2c_write.num_bytes = msgs[i].len; 5742 msg.u.i2c_write.bytes = msgs[i].buf; 5743 5744 memset(txmsg, 0, sizeof(*txmsg)); 5745 txmsg->dst = mstb; 5746 5747 drm_dp_encode_sideband_req(&msg, txmsg); 5748 drm_dp_queue_down_tx(mgr, txmsg); 5749 5750 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 5751 if (ret > 0) { 5752 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 5753 ret = -EREMOTEIO; 5754 goto out; 5755 } 5756 } else { 5757 goto out; 5758 } 5759 } 5760 ret = num; 5761 out: 5762 kfree(txmsg); 5763 return ret; 5764 } 5765 5766 /* I2C device */ 5767 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, 5768 struct i2c_msg *msgs, int num) 5769 { 5770 struct drm_dp_aux *aux = adapter->algo_data; 5771 struct drm_dp_mst_port *port = 5772 container_of(aux, struct drm_dp_mst_port, aux); 5773 struct drm_dp_mst_branch *mstb; 5774 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5775 int ret; 5776 5777 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 5778 if (!mstb) 5779 return -EREMOTEIO; 5780 5781 if (remote_i2c_read_ok(msgs, num)) { 5782 ret = drm_dp_mst_i2c_read(mstb, port, msgs, num); 5783 } else if (remote_i2c_write_ok(msgs, num)) { 5784 ret = drm_dp_mst_i2c_write(mstb, port, msgs, num); 5785 } else { 5786 drm_dbg_kms(mgr->dev, "Unsupported I2C transaction for MST device\n"); 5787 ret = -EIO; 5788 } 5789 5790 drm_dp_mst_topology_put_mstb(mstb); 5791 return ret; 5792 } 5793 5794 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter) 5795 { 5796 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | 5797 I2C_FUNC_SMBUS_READ_BLOCK_DATA | 5798 I2C_FUNC_SMBUS_BLOCK_PROC_CALL | 5799 I2C_FUNC_10BIT_ADDR; 5800 } 5801 5802 static const struct i2c_algorithm drm_dp_mst_i2c_algo = { 5803 .functionality = drm_dp_mst_i2c_functionality, 5804 .master_xfer = drm_dp_mst_i2c_xfer, 5805 }; 5806 5807 /** 5808 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX 5809 * @port: The port to add the I2C bus on 5810 * 5811 * Returns 0 on success or a negative error code on failure. 5812 */ 5813 static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port) 5814 { 5815 struct drm_dp_aux *aux = &port->aux; 5816 struct device *parent_dev = port->mgr->dev->dev; 5817 5818 aux->ddc.algo = &drm_dp_mst_i2c_algo; 5819 aux->ddc.algo_data = aux; 5820 aux->ddc.retries = 3; 5821 5822 aux->ddc.class = I2C_CLASS_DDC; 5823 aux->ddc.owner = THIS_MODULE; 5824 /* FIXME: set the kdev of the port's connector as parent */ 5825 aux->ddc.dev.parent = parent_dev; 5826 aux->ddc.dev.of_node = parent_dev->of_node; 5827 5828 strscpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev), 5829 sizeof(aux->ddc.name)); 5830 5831 return i2c_add_adapter(&aux->ddc); 5832 } 5833 5834 /** 5835 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter 5836 * @port: The port to remove the I2C bus from 5837 */ 5838 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port) 5839 { 5840 i2c_del_adapter(&port->aux.ddc); 5841 } 5842 5843 /** 5844 * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device 5845 * @port: The port to check 5846 * 5847 * A single physical MST hub object can be represented in the topology 5848 * by multiple branches, with virtual ports between those branches. 5849 * 5850 * As of DP1.4, An MST hub with internal (virtual) ports must expose 5851 * certain DPCD registers over those ports. See sections 2.6.1.1.1 5852 * and 2.6.1.1.2 of Display Port specification v1.4 for details. 5853 * 5854 * May acquire mgr->lock 5855 * 5856 * Returns: 5857 * true if the port is a virtual DP peer device, false otherwise 5858 */ 5859 static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port) 5860 { 5861 struct drm_dp_mst_port *downstream_port; 5862 5863 if (!port || port->dpcd_rev < DP_DPCD_REV_14) 5864 return false; 5865 5866 /* Virtual DP Sink (Internal Display Panel) */ 5867 if (port->port_num >= 8) 5868 return true; 5869 5870 /* DP-to-HDMI Protocol Converter */ 5871 if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV && 5872 !port->mcs && 5873 port->ldps) 5874 return true; 5875 5876 /* DP-to-DP */ 5877 mutex_lock(&port->mgr->lock); 5878 if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING && 5879 port->mstb && 5880 port->mstb->num_ports == 2) { 5881 list_for_each_entry(downstream_port, &port->mstb->ports, next) { 5882 if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK && 5883 !downstream_port->input) { 5884 mutex_unlock(&port->mgr->lock); 5885 return true; 5886 } 5887 } 5888 } 5889 mutex_unlock(&port->mgr->lock); 5890 5891 return false; 5892 } 5893 5894 /** 5895 * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC 5896 * @port: The port to check. A leaf of the MST tree with an attached display. 5897 * 5898 * Depending on the situation, DSC may be enabled via the endpoint aux, 5899 * the immediately upstream aux, or the connector's physical aux. 5900 * 5901 * This is both the correct aux to read DSC_CAPABILITY and the 5902 * correct aux to write DSC_ENABLED. 5903 * 5904 * This operation can be expensive (up to four aux reads), so 5905 * the caller should cache the return. 5906 * 5907 * Returns: 5908 * NULL if DSC cannot be enabled on this port, otherwise the aux device 5909 */ 5910 struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port) 5911 { 5912 struct drm_dp_mst_port *immediate_upstream_port; 5913 struct drm_dp_mst_port *fec_port; 5914 struct drm_dp_desc desc = {}; 5915 u8 endpoint_fec; 5916 u8 endpoint_dsc; 5917 5918 if (!port) 5919 return NULL; 5920 5921 if (port->parent->port_parent) 5922 immediate_upstream_port = port->parent->port_parent; 5923 else 5924 immediate_upstream_port = NULL; 5925 5926 fec_port = immediate_upstream_port; 5927 while (fec_port) { 5928 /* 5929 * Each physical link (i.e. not a virtual port) between the 5930 * output and the primary device must support FEC 5931 */ 5932 if (!drm_dp_mst_is_virtual_dpcd(fec_port) && 5933 !fec_port->fec_capable) 5934 return NULL; 5935 5936 fec_port = fec_port->parent->port_parent; 5937 } 5938 5939 /* DP-to-DP peer device */ 5940 if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) { 5941 u8 upstream_dsc; 5942 5943 if (drm_dp_dpcd_read(&port->aux, 5944 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1) 5945 return NULL; 5946 if (drm_dp_dpcd_read(&port->aux, 5947 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1) 5948 return NULL; 5949 if (drm_dp_dpcd_read(&immediate_upstream_port->aux, 5950 DP_DSC_SUPPORT, &upstream_dsc, 1) != 1) 5951 return NULL; 5952 5953 /* Enpoint decompression with DP-to-DP peer device */ 5954 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) && 5955 (endpoint_fec & DP_FEC_CAPABLE) && 5956 (upstream_dsc & DP_DSC_PASSTHROUGH_IS_SUPPORTED)) { 5957 port->passthrough_aux = &immediate_upstream_port->aux; 5958 return &port->aux; 5959 } 5960 5961 /* Virtual DPCD decompression with DP-to-DP peer device */ 5962 return &immediate_upstream_port->aux; 5963 } 5964 5965 /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */ 5966 if (drm_dp_mst_is_virtual_dpcd(port)) 5967 return &port->aux; 5968 5969 /* 5970 * Synaptics quirk 5971 * Applies to ports for which: 5972 * - Physical aux has Synaptics OUI 5973 * - DPv1.4 or higher 5974 * - Port is on primary branch device 5975 * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG) 5976 */ 5977 if (drm_dp_read_desc(port->mgr->aux, &desc, true)) 5978 return NULL; 5979 5980 if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) && 5981 port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 && 5982 port->parent == port->mgr->mst_primary) { 5983 u8 dpcd_ext[DP_RECEIVER_CAP_SIZE]; 5984 5985 if (drm_dp_read_dpcd_caps(port->mgr->aux, dpcd_ext) < 0) 5986 return NULL; 5987 5988 if ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT) && 5989 ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) 5990 != DP_DWN_STRM_PORT_TYPE_ANALOG)) 5991 return port->mgr->aux; 5992 } 5993 5994 /* 5995 * The check below verifies if the MST sink 5996 * connected to the GPU is capable of DSC - 5997 * therefore the endpoint needs to be 5998 * both DSC and FEC capable. 5999 */ 6000 if (drm_dp_dpcd_read(&port->aux, 6001 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1) 6002 return NULL; 6003 if (drm_dp_dpcd_read(&port->aux, 6004 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1) 6005 return NULL; 6006 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) && 6007 (endpoint_fec & DP_FEC_CAPABLE)) 6008 return &port->aux; 6009 6010 return NULL; 6011 } 6012 EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port); 6013