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 #ifdef __linux__ 2235 drm_dbg_kms(port->mgr->dev, "registering %s remote bus for %s\n", 2236 port->aux.name, connector->kdev->kobj.name); 2237 #else 2238 drm_dbg_kms(port->mgr->dev, "registering %s remote bus\n", 2239 port->aux.name); 2240 #endif 2241 2242 port->aux.dev = connector->kdev; 2243 return drm_dp_aux_register_devnode(&port->aux); 2244 } 2245 EXPORT_SYMBOL(drm_dp_mst_connector_late_register); 2246 2247 /** 2248 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration 2249 * @connector: The MST connector 2250 * @port: The MST port for this connector 2251 * 2252 * Helper to unregister the remote aux device for this MST port, registered by 2253 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst 2254 * connector's early_unregister hook. 2255 */ 2256 void drm_dp_mst_connector_early_unregister(struct drm_connector *connector, 2257 struct drm_dp_mst_port *port) 2258 { 2259 #ifdef __linux__ 2260 drm_dbg_kms(port->mgr->dev, "unregistering %s remote bus for %s\n", 2261 port->aux.name, connector->kdev->kobj.name); 2262 #else 2263 drm_dbg_kms(port->mgr->dev, "unregistering %s remote bus\n", 2264 port->aux.name); 2265 #endif 2266 drm_dp_aux_unregister_devnode(&port->aux); 2267 } 2268 EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister); 2269 2270 static void 2271 drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb, 2272 struct drm_dp_mst_port *port) 2273 { 2274 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 2275 char proppath[255]; 2276 int ret; 2277 2278 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath)); 2279 port->connector = mgr->cbs->add_connector(mgr, port, proppath); 2280 if (!port->connector) { 2281 ret = -ENOMEM; 2282 goto error; 2283 } 2284 2285 if (port->pdt != DP_PEER_DEVICE_NONE && 2286 drm_dp_mst_is_end_device(port->pdt, port->mcs) && 2287 port->port_num >= DP_MST_LOGICAL_PORT_0) 2288 port->cached_edid = drm_edid_read_ddc(port->connector, 2289 &port->aux.ddc); 2290 2291 drm_connector_register(port->connector); 2292 return; 2293 2294 error: 2295 drm_err(mgr->dev, "Failed to create connector for port %p: %d\n", port, ret); 2296 } 2297 2298 /* 2299 * Drop a topology reference, and unlink the port from the in-memory topology 2300 * layout 2301 */ 2302 static void 2303 drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr, 2304 struct drm_dp_mst_port *port) 2305 { 2306 mutex_lock(&mgr->lock); 2307 port->parent->num_ports--; 2308 list_del(&port->next); 2309 mutex_unlock(&mgr->lock); 2310 drm_dp_mst_topology_put_port(port); 2311 } 2312 2313 static struct drm_dp_mst_port * 2314 drm_dp_mst_add_port(struct drm_device *dev, 2315 struct drm_dp_mst_topology_mgr *mgr, 2316 struct drm_dp_mst_branch *mstb, u8 port_number) 2317 { 2318 struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL); 2319 2320 if (!port) 2321 return NULL; 2322 2323 kref_init(&port->topology_kref); 2324 kref_init(&port->malloc_kref); 2325 port->parent = mstb; 2326 port->port_num = port_number; 2327 port->mgr = mgr; 2328 port->aux.name = "DPMST"; 2329 port->aux.dev = dev->dev; 2330 port->aux.is_remote = true; 2331 2332 /* initialize the MST downstream port's AUX crc work queue */ 2333 port->aux.drm_dev = dev; 2334 drm_dp_remote_aux_init(&port->aux); 2335 2336 /* 2337 * Make sure the memory allocation for our parent branch stays 2338 * around until our own memory allocation is released 2339 */ 2340 drm_dp_mst_get_mstb_malloc(mstb); 2341 2342 return port; 2343 } 2344 2345 static int 2346 drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb, 2347 struct drm_device *dev, 2348 struct drm_dp_link_addr_reply_port *port_msg) 2349 { 2350 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 2351 struct drm_dp_mst_port *port; 2352 int old_ddps = 0, ret; 2353 u8 new_pdt = DP_PEER_DEVICE_NONE; 2354 bool new_mcs = 0; 2355 bool created = false, send_link_addr = false, changed = false; 2356 2357 port = drm_dp_get_port(mstb, port_msg->port_number); 2358 if (!port) { 2359 port = drm_dp_mst_add_port(dev, mgr, mstb, 2360 port_msg->port_number); 2361 if (!port) 2362 return -ENOMEM; 2363 created = true; 2364 changed = true; 2365 } else if (!port->input && port_msg->input_port && port->connector) { 2366 /* Since port->connector can't be changed here, we create a 2367 * new port if input_port changes from 0 to 1 2368 */ 2369 drm_dp_mst_topology_unlink_port(mgr, port); 2370 drm_dp_mst_topology_put_port(port); 2371 port = drm_dp_mst_add_port(dev, mgr, mstb, 2372 port_msg->port_number); 2373 if (!port) 2374 return -ENOMEM; 2375 changed = true; 2376 created = true; 2377 } else if (port->input && !port_msg->input_port) { 2378 changed = true; 2379 } else if (port->connector) { 2380 /* We're updating a port that's exposed to userspace, so do it 2381 * under lock 2382 */ 2383 drm_modeset_lock(&mgr->base.lock, NULL); 2384 2385 old_ddps = port->ddps; 2386 changed = port->ddps != port_msg->ddps || 2387 (port->ddps && 2388 (port->ldps != port_msg->legacy_device_plug_status || 2389 port->dpcd_rev != port_msg->dpcd_revision || 2390 port->mcs != port_msg->mcs || 2391 port->pdt != port_msg->peer_device_type || 2392 port->num_sdp_stream_sinks != 2393 port_msg->num_sdp_stream_sinks)); 2394 } 2395 2396 port->input = port_msg->input_port; 2397 if (!port->input) 2398 new_pdt = port_msg->peer_device_type; 2399 new_mcs = port_msg->mcs; 2400 port->ddps = port_msg->ddps; 2401 port->ldps = port_msg->legacy_device_plug_status; 2402 port->dpcd_rev = port_msg->dpcd_revision; 2403 port->num_sdp_streams = port_msg->num_sdp_streams; 2404 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks; 2405 2406 /* manage mstb port lists with mgr lock - take a reference 2407 for this list */ 2408 if (created) { 2409 mutex_lock(&mgr->lock); 2410 drm_dp_mst_topology_get_port(port); 2411 list_add(&port->next, &mstb->ports); 2412 mstb->num_ports++; 2413 mutex_unlock(&mgr->lock); 2414 } 2415 2416 /* 2417 * Reprobe PBN caps on both hotplug, and when re-probing the link 2418 * for our parent mstb 2419 */ 2420 if (old_ddps != port->ddps || !created) { 2421 if (port->ddps && !port->input) { 2422 ret = drm_dp_send_enum_path_resources(mgr, mstb, 2423 port); 2424 if (ret == 1) 2425 changed = true; 2426 } else { 2427 port->full_pbn = 0; 2428 } 2429 } 2430 2431 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs); 2432 if (ret == 1) { 2433 send_link_addr = true; 2434 } else if (ret < 0) { 2435 drm_err(dev, "Failed to change PDT on port %p: %d\n", port, ret); 2436 goto fail; 2437 } 2438 2439 /* 2440 * If this port wasn't just created, then we're reprobing because 2441 * we're coming out of suspend. In this case, always resend the link 2442 * address if there's an MSTB on this port 2443 */ 2444 if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING && 2445 port->mcs) 2446 send_link_addr = true; 2447 2448 if (port->connector) 2449 drm_modeset_unlock(&mgr->base.lock); 2450 else if (!port->input) 2451 drm_dp_mst_port_add_connector(mstb, port); 2452 2453 if (send_link_addr && port->mstb) { 2454 ret = drm_dp_send_link_address(mgr, port->mstb); 2455 if (ret == 1) /* MSTB below us changed */ 2456 changed = true; 2457 else if (ret < 0) 2458 goto fail_put; 2459 } 2460 2461 /* put reference to this port */ 2462 drm_dp_mst_topology_put_port(port); 2463 return changed; 2464 2465 fail: 2466 drm_dp_mst_topology_unlink_port(mgr, port); 2467 if (port->connector) 2468 drm_modeset_unlock(&mgr->base.lock); 2469 fail_put: 2470 drm_dp_mst_topology_put_port(port); 2471 return ret; 2472 } 2473 2474 static int 2475 drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb, 2476 struct drm_dp_connection_status_notify *conn_stat) 2477 { 2478 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 2479 struct drm_dp_mst_port *port; 2480 int old_ddps, ret; 2481 u8 new_pdt; 2482 bool new_mcs; 2483 bool dowork = false, create_connector = false; 2484 2485 port = drm_dp_get_port(mstb, conn_stat->port_number); 2486 if (!port) 2487 return 0; 2488 2489 if (port->connector) { 2490 if (!port->input && conn_stat->input_port) { 2491 /* 2492 * We can't remove a connector from an already exposed 2493 * port, so just throw the port out and make sure we 2494 * reprobe the link address of it's parent MSTB 2495 */ 2496 drm_dp_mst_topology_unlink_port(mgr, port); 2497 mstb->link_address_sent = false; 2498 dowork = true; 2499 goto out; 2500 } 2501 2502 /* Locking is only needed if the port's exposed to userspace */ 2503 drm_modeset_lock(&mgr->base.lock, NULL); 2504 } else if (port->input && !conn_stat->input_port) { 2505 create_connector = true; 2506 /* Reprobe link address so we get num_sdp_streams */ 2507 mstb->link_address_sent = false; 2508 dowork = true; 2509 } 2510 2511 old_ddps = port->ddps; 2512 port->input = conn_stat->input_port; 2513 port->ldps = conn_stat->legacy_device_plug_status; 2514 port->ddps = conn_stat->displayport_device_plug_status; 2515 2516 if (old_ddps != port->ddps) { 2517 if (port->ddps && !port->input) 2518 drm_dp_send_enum_path_resources(mgr, mstb, port); 2519 else 2520 port->full_pbn = 0; 2521 } 2522 2523 new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type; 2524 new_mcs = conn_stat->message_capability_status; 2525 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs); 2526 if (ret == 1) { 2527 dowork = true; 2528 } else if (ret < 0) { 2529 drm_err(mgr->dev, "Failed to change PDT for port %p: %d\n", port, ret); 2530 dowork = false; 2531 } 2532 2533 if (port->connector) 2534 drm_modeset_unlock(&mgr->base.lock); 2535 else if (create_connector) 2536 drm_dp_mst_port_add_connector(mstb, port); 2537 2538 out: 2539 drm_dp_mst_topology_put_port(port); 2540 return dowork; 2541 } 2542 2543 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr, 2544 u8 lct, u8 *rad) 2545 { 2546 struct drm_dp_mst_branch *mstb; 2547 struct drm_dp_mst_port *port; 2548 int i, ret; 2549 /* find the port by iterating down */ 2550 2551 mutex_lock(&mgr->lock); 2552 mstb = mgr->mst_primary; 2553 2554 if (!mstb) 2555 goto out; 2556 2557 for (i = 0; i < lct - 1; i++) { 2558 int shift = (i % 2) ? 0 : 4; 2559 int port_num = (rad[i / 2] >> shift) & 0xf; 2560 2561 list_for_each_entry(port, &mstb->ports, next) { 2562 if (port->port_num == port_num) { 2563 mstb = port->mstb; 2564 if (!mstb) { 2565 drm_err(mgr->dev, 2566 "failed to lookup MSTB with lct %d, rad %02x\n", 2567 lct, rad[0]); 2568 goto out; 2569 } 2570 2571 break; 2572 } 2573 } 2574 } 2575 ret = drm_dp_mst_topology_try_get_mstb(mstb); 2576 if (!ret) 2577 mstb = NULL; 2578 out: 2579 mutex_unlock(&mgr->lock); 2580 return mstb; 2581 } 2582 2583 static struct drm_dp_mst_branch *get_mst_branch_device_by_guid_helper( 2584 struct drm_dp_mst_branch *mstb, 2585 const uint8_t *guid) 2586 { 2587 struct drm_dp_mst_branch *found_mstb; 2588 struct drm_dp_mst_port *port; 2589 2590 if (!mstb) 2591 return NULL; 2592 2593 if (memcmp(mstb->guid, guid, 16) == 0) 2594 return mstb; 2595 2596 2597 list_for_each_entry(port, &mstb->ports, next) { 2598 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid); 2599 2600 if (found_mstb) 2601 return found_mstb; 2602 } 2603 2604 return NULL; 2605 } 2606 2607 static struct drm_dp_mst_branch * 2608 drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr, 2609 const uint8_t *guid) 2610 { 2611 struct drm_dp_mst_branch *mstb; 2612 int ret; 2613 2614 /* find the port by iterating down */ 2615 mutex_lock(&mgr->lock); 2616 2617 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid); 2618 if (mstb) { 2619 ret = drm_dp_mst_topology_try_get_mstb(mstb); 2620 if (!ret) 2621 mstb = NULL; 2622 } 2623 2624 mutex_unlock(&mgr->lock); 2625 return mstb; 2626 } 2627 2628 static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 2629 struct drm_dp_mst_branch *mstb) 2630 { 2631 struct drm_dp_mst_port *port; 2632 int ret; 2633 bool changed = false; 2634 2635 if (!mstb->link_address_sent) { 2636 ret = drm_dp_send_link_address(mgr, mstb); 2637 if (ret == 1) 2638 changed = true; 2639 else if (ret < 0) 2640 return ret; 2641 } 2642 2643 list_for_each_entry(port, &mstb->ports, next) { 2644 if (port->input || !port->ddps || !port->mstb) 2645 continue; 2646 2647 ret = drm_dp_check_and_send_link_address(mgr, port->mstb); 2648 if (ret == 1) 2649 changed = true; 2650 else if (ret < 0) 2651 return ret; 2652 } 2653 2654 return changed; 2655 } 2656 2657 static void drm_dp_mst_link_probe_work(struct work_struct *work) 2658 { 2659 struct drm_dp_mst_topology_mgr *mgr = 2660 container_of(work, struct drm_dp_mst_topology_mgr, work); 2661 struct drm_device *dev = mgr->dev; 2662 struct drm_dp_mst_branch *mstb; 2663 int ret; 2664 bool clear_payload_id_table; 2665 2666 mutex_lock(&mgr->probe_lock); 2667 2668 mutex_lock(&mgr->lock); 2669 clear_payload_id_table = !mgr->payload_id_table_cleared; 2670 mgr->payload_id_table_cleared = true; 2671 2672 mstb = mgr->mst_primary; 2673 if (mstb) { 2674 ret = drm_dp_mst_topology_try_get_mstb(mstb); 2675 if (!ret) 2676 mstb = NULL; 2677 } 2678 mutex_unlock(&mgr->lock); 2679 if (!mstb) { 2680 mutex_unlock(&mgr->probe_lock); 2681 return; 2682 } 2683 2684 /* 2685 * Certain branch devices seem to incorrectly report an available_pbn 2686 * of 0 on downstream sinks, even after clearing the 2687 * DP_PAYLOAD_ALLOCATE_* registers in 2688 * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C 2689 * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make 2690 * things work again. 2691 */ 2692 if (clear_payload_id_table) { 2693 drm_dbg_kms(dev, "Clearing payload ID table\n"); 2694 drm_dp_send_clear_payload_id_table(mgr, mstb); 2695 } 2696 2697 ret = drm_dp_check_and_send_link_address(mgr, mstb); 2698 drm_dp_mst_topology_put_mstb(mstb); 2699 2700 mutex_unlock(&mgr->probe_lock); 2701 if (ret > 0) 2702 drm_kms_helper_hotplug_event(dev); 2703 } 2704 2705 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, 2706 u8 *guid) 2707 { 2708 u64 salt; 2709 2710 if (memchr_inv(guid, 0, 16)) 2711 return true; 2712 2713 salt = get_jiffies_64(); 2714 2715 memcpy(&guid[0], &salt, sizeof(u64)); 2716 memcpy(&guid[8], &salt, sizeof(u64)); 2717 2718 return false; 2719 } 2720 2721 static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, 2722 u8 port_num, u32 offset, u8 num_bytes) 2723 { 2724 struct drm_dp_sideband_msg_req_body req; 2725 2726 req.req_type = DP_REMOTE_DPCD_READ; 2727 req.u.dpcd_read.port_number = port_num; 2728 req.u.dpcd_read.dpcd_address = offset; 2729 req.u.dpcd_read.num_bytes = num_bytes; 2730 drm_dp_encode_sideband_req(&req, msg); 2731 } 2732 2733 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr, 2734 bool up, u8 *msg, int len) 2735 { 2736 int ret; 2737 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE; 2738 int tosend, total, offset; 2739 int retries = 0; 2740 2741 retry: 2742 total = len; 2743 offset = 0; 2744 do { 2745 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total); 2746 2747 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset, 2748 &msg[offset], 2749 tosend); 2750 if (ret != tosend) { 2751 if (ret == -EIO && retries < 5) { 2752 retries++; 2753 goto retry; 2754 } 2755 drm_dbg_kms(mgr->dev, "failed to dpcd write %d %d\n", tosend, ret); 2756 2757 return -EIO; 2758 } 2759 offset += tosend; 2760 total -= tosend; 2761 } while (total > 0); 2762 return 0; 2763 } 2764 2765 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr, 2766 struct drm_dp_sideband_msg_tx *txmsg) 2767 { 2768 struct drm_dp_mst_branch *mstb = txmsg->dst; 2769 u8 req_type; 2770 2771 req_type = txmsg->msg[0] & 0x7f; 2772 if (req_type == DP_CONNECTION_STATUS_NOTIFY || 2773 req_type == DP_RESOURCE_STATUS_NOTIFY || 2774 req_type == DP_CLEAR_PAYLOAD_ID_TABLE) 2775 hdr->broadcast = 1; 2776 else 2777 hdr->broadcast = 0; 2778 hdr->path_msg = txmsg->path_msg; 2779 if (hdr->broadcast) { 2780 hdr->lct = 1; 2781 hdr->lcr = 6; 2782 } else { 2783 hdr->lct = mstb->lct; 2784 hdr->lcr = mstb->lct - 1; 2785 } 2786 2787 memcpy(hdr->rad, mstb->rad, hdr->lct / 2); 2788 2789 return 0; 2790 } 2791 /* 2792 * process a single block of the next message in the sideband queue 2793 */ 2794 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr, 2795 struct drm_dp_sideband_msg_tx *txmsg, 2796 bool up) 2797 { 2798 u8 chunk[48]; 2799 struct drm_dp_sideband_msg_hdr hdr; 2800 int len, space, idx, tosend; 2801 int ret; 2802 2803 if (txmsg->state == DRM_DP_SIDEBAND_TX_SENT) 2804 return 0; 2805 2806 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr)); 2807 2808 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) 2809 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND; 2810 2811 /* make hdr from dst mst */ 2812 ret = set_hdr_from_dst_qlock(&hdr, txmsg); 2813 if (ret < 0) 2814 return ret; 2815 2816 /* amount left to send in this message */ 2817 len = txmsg->cur_len - txmsg->cur_offset; 2818 2819 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */ 2820 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr); 2821 2822 tosend = min(len, space); 2823 if (len == txmsg->cur_len) 2824 hdr.somt = 1; 2825 if (space >= len) 2826 hdr.eomt = 1; 2827 2828 2829 hdr.msg_len = tosend + 1; 2830 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx); 2831 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend); 2832 /* add crc at end */ 2833 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend); 2834 idx += tosend + 1; 2835 2836 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx); 2837 if (ret) { 2838 if (drm_debug_enabled(DRM_UT_DP)) { 2839 struct drm_printer p = drm_debug_printer(DBG_PREFIX); 2840 2841 drm_printf(&p, "sideband msg failed to send\n"); 2842 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 2843 } 2844 return ret; 2845 } 2846 2847 txmsg->cur_offset += tosend; 2848 if (txmsg->cur_offset == txmsg->cur_len) { 2849 txmsg->state = DRM_DP_SIDEBAND_TX_SENT; 2850 return 1; 2851 } 2852 return 0; 2853 } 2854 2855 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr) 2856 { 2857 struct drm_dp_sideband_msg_tx *txmsg; 2858 int ret; 2859 2860 WARN_ON(!mutex_is_locked(&mgr->qlock)); 2861 2862 /* construct a chunk from the first msg in the tx_msg queue */ 2863 if (list_empty(&mgr->tx_msg_downq)) 2864 return; 2865 2866 txmsg = list_first_entry(&mgr->tx_msg_downq, 2867 struct drm_dp_sideband_msg_tx, next); 2868 ret = process_single_tx_qlock(mgr, txmsg, false); 2869 if (ret < 0) { 2870 drm_dbg_kms(mgr->dev, "failed to send msg in q %d\n", ret); 2871 list_del(&txmsg->next); 2872 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 2873 wake_up_all(&mgr->tx_waitq); 2874 } 2875 } 2876 2877 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr, 2878 struct drm_dp_sideband_msg_tx *txmsg) 2879 { 2880 mutex_lock(&mgr->qlock); 2881 list_add_tail(&txmsg->next, &mgr->tx_msg_downq); 2882 2883 if (drm_debug_enabled(DRM_UT_DP)) { 2884 struct drm_printer p = drm_debug_printer(DBG_PREFIX); 2885 2886 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 2887 } 2888 2889 if (list_is_singular(&mgr->tx_msg_downq)) 2890 process_single_down_tx_qlock(mgr); 2891 mutex_unlock(&mgr->qlock); 2892 } 2893 2894 static void 2895 drm_dp_dump_link_address(const struct drm_dp_mst_topology_mgr *mgr, 2896 struct drm_dp_link_address_ack_reply *reply) 2897 { 2898 struct drm_dp_link_addr_reply_port *port_reply; 2899 int i; 2900 2901 for (i = 0; i < reply->nports; i++) { 2902 port_reply = &reply->ports[i]; 2903 drm_dbg_kms(mgr->dev, 2904 "port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", 2905 i, 2906 port_reply->input_port, 2907 port_reply->peer_device_type, 2908 port_reply->port_number, 2909 port_reply->dpcd_revision, 2910 port_reply->mcs, 2911 port_reply->ddps, 2912 port_reply->legacy_device_plug_status, 2913 port_reply->num_sdp_streams, 2914 port_reply->num_sdp_stream_sinks); 2915 } 2916 } 2917 2918 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 2919 struct drm_dp_mst_branch *mstb) 2920 { 2921 struct drm_dp_sideband_msg_tx *txmsg; 2922 struct drm_dp_link_address_ack_reply *reply; 2923 struct drm_dp_mst_port *port, *tmp; 2924 int i, ret, port_mask = 0; 2925 bool changed = false; 2926 2927 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 2928 if (!txmsg) 2929 return -ENOMEM; 2930 2931 txmsg->dst = mstb; 2932 build_link_address(txmsg); 2933 2934 mstb->link_address_sent = true; 2935 drm_dp_queue_down_tx(mgr, txmsg); 2936 2937 /* FIXME: Actually do some real error handling here */ 2938 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 2939 if (ret < 0) { 2940 drm_err(mgr->dev, "Sending link address failed with %d\n", ret); 2941 goto out; 2942 } 2943 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 2944 drm_err(mgr->dev, "link address NAK received\n"); 2945 ret = -EIO; 2946 goto out; 2947 } 2948 2949 reply = &txmsg->reply.u.link_addr; 2950 drm_dbg_kms(mgr->dev, "link address reply: %d\n", reply->nports); 2951 drm_dp_dump_link_address(mgr, reply); 2952 2953 ret = drm_dp_check_mstb_guid(mstb, reply->guid); 2954 if (ret) { 2955 char buf[64]; 2956 2957 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf)); 2958 drm_err(mgr->dev, "GUID check on %s failed: %d\n", buf, ret); 2959 goto out; 2960 } 2961 2962 for (i = 0; i < reply->nports; i++) { 2963 port_mask |= BIT(reply->ports[i].port_number); 2964 ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev, 2965 &reply->ports[i]); 2966 if (ret == 1) 2967 changed = true; 2968 else if (ret < 0) 2969 goto out; 2970 } 2971 2972 /* Prune any ports that are currently a part of mstb in our in-memory 2973 * topology, but were not seen in this link address. Usually this 2974 * means that they were removed while the topology was out of sync, 2975 * e.g. during suspend/resume 2976 */ 2977 mutex_lock(&mgr->lock); 2978 list_for_each_entry_safe(port, tmp, &mstb->ports, next) { 2979 if (port_mask & BIT(port->port_num)) 2980 continue; 2981 2982 drm_dbg_kms(mgr->dev, "port %d was not in link address, removing\n", 2983 port->port_num); 2984 list_del(&port->next); 2985 drm_dp_mst_topology_put_port(port); 2986 changed = true; 2987 } 2988 mutex_unlock(&mgr->lock); 2989 2990 out: 2991 if (ret < 0) 2992 mstb->link_address_sent = false; 2993 kfree(txmsg); 2994 return ret < 0 ? ret : changed; 2995 } 2996 2997 static void 2998 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr, 2999 struct drm_dp_mst_branch *mstb) 3000 { 3001 struct drm_dp_sideband_msg_tx *txmsg; 3002 int ret; 3003 3004 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3005 if (!txmsg) 3006 return; 3007 3008 txmsg->dst = mstb; 3009 build_clear_payload_id_table(txmsg); 3010 3011 drm_dp_queue_down_tx(mgr, txmsg); 3012 3013 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3014 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3015 drm_dbg_kms(mgr->dev, "clear payload table id nak received\n"); 3016 3017 kfree(txmsg); 3018 } 3019 3020 static int 3021 drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, 3022 struct drm_dp_mst_branch *mstb, 3023 struct drm_dp_mst_port *port) 3024 { 3025 struct drm_dp_enum_path_resources_ack_reply *path_res; 3026 struct drm_dp_sideband_msg_tx *txmsg; 3027 int ret; 3028 3029 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3030 if (!txmsg) 3031 return -ENOMEM; 3032 3033 txmsg->dst = mstb; 3034 build_enum_path_resources(txmsg, port->port_num); 3035 3036 drm_dp_queue_down_tx(mgr, txmsg); 3037 3038 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3039 if (ret > 0) { 3040 ret = 0; 3041 path_res = &txmsg->reply.u.path_resources; 3042 3043 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3044 drm_dbg_kms(mgr->dev, "enum path resources nak received\n"); 3045 } else { 3046 if (port->port_num != path_res->port_number) 3047 DRM_ERROR("got incorrect port in response\n"); 3048 3049 drm_dbg_kms(mgr->dev, "enum path resources %d: %d %d\n", 3050 path_res->port_number, 3051 path_res->full_payload_bw_number, 3052 path_res->avail_payload_bw_number); 3053 3054 /* 3055 * If something changed, make sure we send a 3056 * hotplug 3057 */ 3058 if (port->full_pbn != path_res->full_payload_bw_number || 3059 port->fec_capable != path_res->fec_capable) 3060 ret = 1; 3061 3062 port->full_pbn = path_res->full_payload_bw_number; 3063 port->fec_capable = path_res->fec_capable; 3064 } 3065 } 3066 3067 kfree(txmsg); 3068 return ret; 3069 } 3070 3071 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb) 3072 { 3073 if (!mstb->port_parent) 3074 return NULL; 3075 3076 if (mstb->port_parent->mstb != mstb) 3077 return mstb->port_parent; 3078 3079 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent); 3080 } 3081 3082 /* 3083 * Searches upwards in the topology starting from mstb to try to find the 3084 * closest available parent of mstb that's still connected to the rest of the 3085 * topology. This can be used in order to perform operations like releasing 3086 * payloads, where the branch device which owned the payload may no longer be 3087 * around and thus would require that the payload on the last living relative 3088 * be freed instead. 3089 */ 3090 static struct drm_dp_mst_branch * 3091 drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr, 3092 struct drm_dp_mst_branch *mstb, 3093 int *port_num) 3094 { 3095 struct drm_dp_mst_branch *rmstb = NULL; 3096 struct drm_dp_mst_port *found_port; 3097 3098 mutex_lock(&mgr->lock); 3099 if (!mgr->mst_primary) 3100 goto out; 3101 3102 do { 3103 found_port = drm_dp_get_last_connected_port_to_mstb(mstb); 3104 if (!found_port) 3105 break; 3106 3107 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) { 3108 rmstb = found_port->parent; 3109 *port_num = found_port->port_num; 3110 } else { 3111 /* Search again, starting from this parent */ 3112 mstb = found_port->parent; 3113 } 3114 } while (!rmstb); 3115 out: 3116 mutex_unlock(&mgr->lock); 3117 return rmstb; 3118 } 3119 3120 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr, 3121 struct drm_dp_mst_port *port, 3122 int id, 3123 int pbn) 3124 { 3125 struct drm_dp_sideband_msg_tx *txmsg; 3126 struct drm_dp_mst_branch *mstb; 3127 int ret, port_num; 3128 u8 sinks[DRM_DP_MAX_SDP_STREAMS]; 3129 int i; 3130 3131 port_num = port->port_num; 3132 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 3133 if (!mstb) { 3134 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, 3135 port->parent, 3136 &port_num); 3137 3138 if (!mstb) 3139 return -EINVAL; 3140 } 3141 3142 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3143 if (!txmsg) { 3144 ret = -ENOMEM; 3145 goto fail_put; 3146 } 3147 3148 for (i = 0; i < port->num_sdp_streams; i++) 3149 sinks[i] = i; 3150 3151 txmsg->dst = mstb; 3152 build_allocate_payload(txmsg, port_num, 3153 id, 3154 pbn, port->num_sdp_streams, sinks); 3155 3156 drm_dp_queue_down_tx(mgr, txmsg); 3157 3158 /* 3159 * FIXME: there is a small chance that between getting the last 3160 * connected mstb and sending the payload message, the last connected 3161 * mstb could also be removed from the topology. In the future, this 3162 * needs to be fixed by restarting the 3163 * drm_dp_get_last_connected_port_and_mstb() search in the event of a 3164 * timeout if the topology is still connected to the system. 3165 */ 3166 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3167 if (ret > 0) { 3168 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3169 ret = -EINVAL; 3170 else 3171 ret = 0; 3172 } 3173 kfree(txmsg); 3174 fail_put: 3175 drm_dp_mst_topology_put_mstb(mstb); 3176 return ret; 3177 } 3178 3179 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr, 3180 struct drm_dp_mst_port *port, bool power_up) 3181 { 3182 struct drm_dp_sideband_msg_tx *txmsg; 3183 int ret; 3184 3185 port = drm_dp_mst_topology_get_port_validated(mgr, port); 3186 if (!port) 3187 return -EINVAL; 3188 3189 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3190 if (!txmsg) { 3191 drm_dp_mst_topology_put_port(port); 3192 return -ENOMEM; 3193 } 3194 3195 txmsg->dst = port->parent; 3196 build_power_updown_phy(txmsg, port->port_num, power_up); 3197 drm_dp_queue_down_tx(mgr, txmsg); 3198 3199 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg); 3200 if (ret > 0) { 3201 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3202 ret = -EINVAL; 3203 else 3204 ret = 0; 3205 } 3206 kfree(txmsg); 3207 drm_dp_mst_topology_put_port(port); 3208 3209 return ret; 3210 } 3211 EXPORT_SYMBOL(drm_dp_send_power_updown_phy); 3212 3213 int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr, 3214 struct drm_dp_mst_port *port, 3215 struct drm_dp_query_stream_enc_status_ack_reply *status) 3216 { 3217 struct drm_dp_mst_topology_state *state; 3218 struct drm_dp_mst_atomic_payload *payload; 3219 struct drm_dp_sideband_msg_tx *txmsg; 3220 u8 nonce[7]; 3221 int ret; 3222 3223 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3224 if (!txmsg) 3225 return -ENOMEM; 3226 3227 port = drm_dp_mst_topology_get_port_validated(mgr, port); 3228 if (!port) { 3229 ret = -EINVAL; 3230 goto out_get_port; 3231 } 3232 3233 get_random_bytes(nonce, sizeof(nonce)); 3234 3235 drm_modeset_lock(&mgr->base.lock, NULL); 3236 state = to_drm_dp_mst_topology_state(mgr->base.state); 3237 payload = drm_atomic_get_mst_payload_state(state, port); 3238 3239 /* 3240 * "Source device targets the QUERY_STREAM_ENCRYPTION_STATUS message 3241 * transaction at the MST Branch device directly connected to the 3242 * Source" 3243 */ 3244 txmsg->dst = mgr->mst_primary; 3245 3246 build_query_stream_enc_status(txmsg, payload->vcpi, nonce); 3247 3248 drm_dp_queue_down_tx(mgr, txmsg); 3249 3250 ret = drm_dp_mst_wait_tx_reply(mgr->mst_primary, txmsg); 3251 if (ret < 0) { 3252 goto out; 3253 } else if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3254 drm_dbg_kms(mgr->dev, "query encryption status nak received\n"); 3255 ret = -ENXIO; 3256 goto out; 3257 } 3258 3259 ret = 0; 3260 memcpy(status, &txmsg->reply.u.enc_status, sizeof(*status)); 3261 3262 out: 3263 drm_modeset_unlock(&mgr->base.lock); 3264 drm_dp_mst_topology_put_port(port); 3265 out_get_port: 3266 kfree(txmsg); 3267 return ret; 3268 } 3269 EXPORT_SYMBOL(drm_dp_send_query_stream_enc_status); 3270 3271 static int drm_dp_create_payload_step1(struct drm_dp_mst_topology_mgr *mgr, 3272 struct drm_dp_mst_atomic_payload *payload) 3273 { 3274 return drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot, 3275 payload->time_slots); 3276 } 3277 3278 static int drm_dp_create_payload_step2(struct drm_dp_mst_topology_mgr *mgr, 3279 struct drm_dp_mst_atomic_payload *payload) 3280 { 3281 int ret; 3282 struct drm_dp_mst_port *port = drm_dp_mst_topology_get_port_validated(mgr, payload->port); 3283 3284 if (!port) 3285 return -EIO; 3286 3287 ret = drm_dp_payload_send_msg(mgr, port, payload->vcpi, payload->pbn); 3288 drm_dp_mst_topology_put_port(port); 3289 return ret; 3290 } 3291 3292 static int drm_dp_destroy_payload_step1(struct drm_dp_mst_topology_mgr *mgr, 3293 struct drm_dp_mst_topology_state *mst_state, 3294 struct drm_dp_mst_atomic_payload *payload) 3295 { 3296 drm_dbg_kms(mgr->dev, "\n"); 3297 3298 /* it's okay for these to fail */ 3299 drm_dp_payload_send_msg(mgr, payload->port, payload->vcpi, 0); 3300 drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot, 0); 3301 3302 return 0; 3303 } 3304 3305 /** 3306 * drm_dp_add_payload_part1() - Execute payload update part 1 3307 * @mgr: Manager to use. 3308 * @mst_state: The MST atomic state 3309 * @payload: The payload to write 3310 * 3311 * Determines the starting time slot for the given payload, and programs the VCPI for this payload 3312 * into hardware. After calling this, the driver should generate ACT and payload packets. 3313 * 3314 * Returns: 0 on success, error code on failure. In the event that this fails, 3315 * @payload.vc_start_slot will also be set to -1. 3316 */ 3317 int drm_dp_add_payload_part1(struct drm_dp_mst_topology_mgr *mgr, 3318 struct drm_dp_mst_topology_state *mst_state, 3319 struct drm_dp_mst_atomic_payload *payload) 3320 { 3321 struct drm_dp_mst_port *port; 3322 int ret; 3323 3324 port = drm_dp_mst_topology_get_port_validated(mgr, payload->port); 3325 if (!port) { 3326 drm_dbg_kms(mgr->dev, 3327 "VCPI %d for port %p not in topology, not creating a payload\n", 3328 payload->vcpi, payload->port); 3329 payload->vc_start_slot = -1; 3330 return 0; 3331 } 3332 3333 if (mgr->payload_count == 0) 3334 mgr->next_start_slot = mst_state->start_slot; 3335 3336 payload->vc_start_slot = mgr->next_start_slot; 3337 3338 ret = drm_dp_create_payload_step1(mgr, payload); 3339 drm_dp_mst_topology_put_port(port); 3340 if (ret < 0) { 3341 drm_warn(mgr->dev, "Failed to create MST payload for port %p: %d\n", 3342 payload->port, ret); 3343 payload->vc_start_slot = -1; 3344 return ret; 3345 } 3346 3347 mgr->payload_count++; 3348 mgr->next_start_slot += payload->time_slots; 3349 3350 return 0; 3351 } 3352 EXPORT_SYMBOL(drm_dp_add_payload_part1); 3353 3354 /** 3355 * drm_dp_remove_payload() - Remove an MST payload 3356 * @mgr: Manager to use. 3357 * @mst_state: The MST atomic state 3358 * @old_payload: The payload with its old state 3359 * @new_payload: The payload to write 3360 * 3361 * Removes a payload from an MST topology if it was successfully assigned a start slot. Also updates 3362 * the starting time slots of all other payloads which would have been shifted towards the start of 3363 * the VC table as a result. After calling this, the driver should generate ACT and payload packets. 3364 */ 3365 void drm_dp_remove_payload(struct drm_dp_mst_topology_mgr *mgr, 3366 struct drm_dp_mst_topology_state *mst_state, 3367 const struct drm_dp_mst_atomic_payload *old_payload, 3368 struct drm_dp_mst_atomic_payload *new_payload) 3369 { 3370 struct drm_dp_mst_atomic_payload *pos; 3371 bool send_remove = false; 3372 3373 /* We failed to make the payload, so nothing to do */ 3374 if (new_payload->vc_start_slot == -1) 3375 return; 3376 3377 mutex_lock(&mgr->lock); 3378 send_remove = drm_dp_mst_port_downstream_of_branch(new_payload->port, mgr->mst_primary); 3379 mutex_unlock(&mgr->lock); 3380 3381 if (send_remove) 3382 drm_dp_destroy_payload_step1(mgr, mst_state, new_payload); 3383 else 3384 drm_dbg_kms(mgr->dev, "Payload for VCPI %d not in topology, not sending remove\n", 3385 new_payload->vcpi); 3386 3387 list_for_each_entry(pos, &mst_state->payloads, next) { 3388 if (pos != new_payload && pos->vc_start_slot > new_payload->vc_start_slot) 3389 pos->vc_start_slot -= old_payload->time_slots; 3390 } 3391 new_payload->vc_start_slot = -1; 3392 3393 mgr->payload_count--; 3394 mgr->next_start_slot -= old_payload->time_slots; 3395 3396 if (new_payload->delete) 3397 drm_dp_mst_put_port_malloc(new_payload->port); 3398 } 3399 EXPORT_SYMBOL(drm_dp_remove_payload); 3400 3401 /** 3402 * drm_dp_add_payload_part2() - Execute payload update part 2 3403 * @mgr: Manager to use. 3404 * @state: The global atomic state 3405 * @payload: The payload to update 3406 * 3407 * If @payload was successfully assigned a starting time slot by drm_dp_add_payload_part1(), this 3408 * function will send the sideband messages to finish allocating this payload. 3409 * 3410 * Returns: 0 on success, negative error code on failure. 3411 */ 3412 int drm_dp_add_payload_part2(struct drm_dp_mst_topology_mgr *mgr, 3413 struct drm_atomic_state *state, 3414 struct drm_dp_mst_atomic_payload *payload) 3415 { 3416 int ret = 0; 3417 3418 /* Skip failed payloads */ 3419 if (payload->vc_start_slot == -1) { 3420 drm_dbg_kms(mgr->dev, "Part 1 of payload creation for %s failed, skipping part 2\n", 3421 payload->port->connector->name); 3422 return -EIO; 3423 } 3424 3425 ret = drm_dp_create_payload_step2(mgr, payload); 3426 if (ret < 0) { 3427 if (!payload->delete) 3428 drm_err(mgr->dev, "Step 2 of creating MST payload for %p failed: %d\n", 3429 payload->port, ret); 3430 else 3431 drm_dbg_kms(mgr->dev, "Step 2 of removing MST payload for %p failed: %d\n", 3432 payload->port, ret); 3433 } 3434 3435 return ret; 3436 } 3437 EXPORT_SYMBOL(drm_dp_add_payload_part2); 3438 3439 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, 3440 struct drm_dp_mst_port *port, 3441 int offset, int size, u8 *bytes) 3442 { 3443 int ret = 0; 3444 struct drm_dp_sideband_msg_tx *txmsg; 3445 struct drm_dp_mst_branch *mstb; 3446 3447 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 3448 if (!mstb) 3449 return -EINVAL; 3450 3451 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3452 if (!txmsg) { 3453 ret = -ENOMEM; 3454 goto fail_put; 3455 } 3456 3457 build_dpcd_read(txmsg, port->port_num, offset, size); 3458 txmsg->dst = port->parent; 3459 3460 drm_dp_queue_down_tx(mgr, txmsg); 3461 3462 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3463 if (ret < 0) 3464 goto fail_free; 3465 3466 if (txmsg->reply.reply_type == 1) { 3467 drm_dbg_kms(mgr->dev, "mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n", 3468 mstb, port->port_num, offset, size); 3469 ret = -EIO; 3470 goto fail_free; 3471 } 3472 3473 if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) { 3474 ret = -EPROTO; 3475 goto fail_free; 3476 } 3477 3478 ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes, 3479 size); 3480 memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret); 3481 3482 fail_free: 3483 kfree(txmsg); 3484 fail_put: 3485 drm_dp_mst_topology_put_mstb(mstb); 3486 3487 return ret; 3488 } 3489 3490 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, 3491 struct drm_dp_mst_port *port, 3492 int offset, int size, u8 *bytes) 3493 { 3494 int ret; 3495 struct drm_dp_sideband_msg_tx *txmsg; 3496 struct drm_dp_mst_branch *mstb; 3497 3498 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 3499 if (!mstb) 3500 return -EINVAL; 3501 3502 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3503 if (!txmsg) { 3504 ret = -ENOMEM; 3505 goto fail_put; 3506 } 3507 3508 build_dpcd_write(txmsg, port->port_num, offset, size, bytes); 3509 txmsg->dst = mstb; 3510 3511 drm_dp_queue_down_tx(mgr, txmsg); 3512 3513 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3514 if (ret > 0) { 3515 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3516 ret = -EIO; 3517 else 3518 ret = size; 3519 } 3520 3521 kfree(txmsg); 3522 fail_put: 3523 drm_dp_mst_topology_put_mstb(mstb); 3524 return ret; 3525 } 3526 3527 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type) 3528 { 3529 struct drm_dp_sideband_msg_reply_body reply; 3530 3531 reply.reply_type = DP_SIDEBAND_REPLY_ACK; 3532 reply.req_type = req_type; 3533 drm_dp_encode_sideband_reply(&reply, msg); 3534 return 0; 3535 } 3536 3537 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr, 3538 struct drm_dp_mst_branch *mstb, 3539 int req_type, bool broadcast) 3540 { 3541 struct drm_dp_sideband_msg_tx *txmsg; 3542 3543 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3544 if (!txmsg) 3545 return -ENOMEM; 3546 3547 txmsg->dst = mstb; 3548 drm_dp_encode_up_ack_reply(txmsg, req_type); 3549 3550 mutex_lock(&mgr->qlock); 3551 /* construct a chunk from the first msg in the tx_msg queue */ 3552 process_single_tx_qlock(mgr, txmsg, true); 3553 mutex_unlock(&mgr->qlock); 3554 3555 kfree(txmsg); 3556 return 0; 3557 } 3558 3559 /** 3560 * drm_dp_get_vc_payload_bw - get the VC payload BW for an MST link 3561 * @mgr: The &drm_dp_mst_topology_mgr to use 3562 * @link_rate: link rate in 10kbits/s units 3563 * @link_lane_count: lane count 3564 * 3565 * Calculate the total bandwidth of a MultiStream Transport link. The returned 3566 * value is in units of PBNs/(timeslots/1 MTP). This value can be used to 3567 * convert the number of PBNs required for a given stream to the number of 3568 * timeslots this stream requires in each MTP. 3569 */ 3570 int drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr, 3571 int link_rate, int link_lane_count) 3572 { 3573 if (link_rate == 0 || link_lane_count == 0) 3574 drm_dbg_kms(mgr->dev, "invalid link rate/lane count: (%d / %d)\n", 3575 link_rate, link_lane_count); 3576 3577 /* See DP v2.0 2.6.4.2, VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */ 3578 return link_rate * link_lane_count / 54000; 3579 } 3580 EXPORT_SYMBOL(drm_dp_get_vc_payload_bw); 3581 3582 /** 3583 * drm_dp_read_mst_cap() - check whether or not a sink supports MST 3584 * @aux: The DP AUX channel to use 3585 * @dpcd: A cached copy of the DPCD capabilities for this sink 3586 * 3587 * Returns: %True if the sink supports MST, %false otherwise 3588 */ 3589 bool drm_dp_read_mst_cap(struct drm_dp_aux *aux, 3590 const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 3591 { 3592 u8 mstm_cap; 3593 3594 if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_12) 3595 return false; 3596 3597 if (drm_dp_dpcd_readb(aux, DP_MSTM_CAP, &mstm_cap) != 1) 3598 return false; 3599 3600 return mstm_cap & DP_MST_CAP; 3601 } 3602 EXPORT_SYMBOL(drm_dp_read_mst_cap); 3603 3604 /** 3605 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager 3606 * @mgr: manager to set state for 3607 * @mst_state: true to enable MST on this connector - false to disable. 3608 * 3609 * This is called by the driver when it detects an MST capable device plugged 3610 * into a DP MST capable port, or when a DP MST capable device is unplugged. 3611 */ 3612 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state) 3613 { 3614 int ret = 0; 3615 struct drm_dp_mst_branch *mstb = NULL; 3616 3617 mutex_lock(&mgr->lock); 3618 if (mst_state == mgr->mst_state) 3619 goto out_unlock; 3620 3621 mgr->mst_state = mst_state; 3622 /* set the device into MST mode */ 3623 if (mst_state) { 3624 WARN_ON(mgr->mst_primary); 3625 3626 /* get dpcd info */ 3627 ret = drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd); 3628 if (ret < 0) { 3629 drm_dbg_kms(mgr->dev, "%s: failed to read DPCD, ret %d\n", 3630 mgr->aux->name, ret); 3631 goto out_unlock; 3632 } 3633 3634 /* add initial branch device at LCT 1 */ 3635 mstb = drm_dp_add_mst_branch_device(1, NULL); 3636 if (mstb == NULL) { 3637 ret = -ENOMEM; 3638 goto out_unlock; 3639 } 3640 mstb->mgr = mgr; 3641 3642 /* give this the main reference */ 3643 mgr->mst_primary = mstb; 3644 drm_dp_mst_topology_get_mstb(mgr->mst_primary); 3645 3646 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 3647 DP_MST_EN | 3648 DP_UP_REQ_EN | 3649 DP_UPSTREAM_IS_SRC); 3650 if (ret < 0) 3651 goto out_unlock; 3652 3653 /* Write reset payload */ 3654 drm_dp_dpcd_write_payload(mgr, 0, 0, 0x3f); 3655 3656 queue_work(system_long_wq, &mgr->work); 3657 3658 ret = 0; 3659 } else { 3660 /* disable MST on the device */ 3661 mstb = mgr->mst_primary; 3662 mgr->mst_primary = NULL; 3663 /* this can fail if the device is gone */ 3664 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0); 3665 ret = 0; 3666 mgr->payload_id_table_cleared = false; 3667 3668 mgr->reset_rx_state = true; 3669 } 3670 3671 out_unlock: 3672 mutex_unlock(&mgr->lock); 3673 if (mstb) 3674 drm_dp_mst_topology_put_mstb(mstb); 3675 return ret; 3676 3677 } 3678 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst); 3679 3680 static void 3681 drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb) 3682 { 3683 struct drm_dp_mst_port *port; 3684 3685 /* The link address will need to be re-sent on resume */ 3686 mstb->link_address_sent = false; 3687 3688 list_for_each_entry(port, &mstb->ports, next) 3689 if (port->mstb) 3690 drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb); 3691 } 3692 3693 /** 3694 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager 3695 * @mgr: manager to suspend 3696 * 3697 * This function tells the MST device that we can't handle UP messages 3698 * anymore. This should stop it from sending any since we are suspended. 3699 */ 3700 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr) 3701 { 3702 mutex_lock(&mgr->lock); 3703 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 3704 DP_MST_EN | DP_UPSTREAM_IS_SRC); 3705 mutex_unlock(&mgr->lock); 3706 flush_work(&mgr->up_req_work); 3707 flush_work(&mgr->work); 3708 flush_work(&mgr->delayed_destroy_work); 3709 3710 mutex_lock(&mgr->lock); 3711 if (mgr->mst_state && mgr->mst_primary) 3712 drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary); 3713 mutex_unlock(&mgr->lock); 3714 } 3715 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend); 3716 3717 /** 3718 * drm_dp_mst_topology_mgr_resume() - resume the MST manager 3719 * @mgr: manager to resume 3720 * @sync: whether or not to perform topology reprobing synchronously 3721 * 3722 * This will fetch DPCD and see if the device is still there, 3723 * if it is, it will rewrite the MSTM control bits, and return. 3724 * 3725 * If the device fails this returns -1, and the driver should do 3726 * a full MST reprobe, in case we were undocked. 3727 * 3728 * During system resume (where it is assumed that the driver will be calling 3729 * drm_atomic_helper_resume()) this function should be called beforehand with 3730 * @sync set to true. In contexts like runtime resume where the driver is not 3731 * expected to be calling drm_atomic_helper_resume(), this function should be 3732 * called with @sync set to false in order to avoid deadlocking. 3733 * 3734 * Returns: -1 if the MST topology was removed while we were suspended, 0 3735 * otherwise. 3736 */ 3737 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr, 3738 bool sync) 3739 { 3740 int ret; 3741 u8 guid[16]; 3742 3743 mutex_lock(&mgr->lock); 3744 if (!mgr->mst_primary) 3745 goto out_fail; 3746 3747 if (drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd) < 0) { 3748 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n"); 3749 goto out_fail; 3750 } 3751 3752 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 3753 DP_MST_EN | 3754 DP_UP_REQ_EN | 3755 DP_UPSTREAM_IS_SRC); 3756 if (ret < 0) { 3757 drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n"); 3758 goto out_fail; 3759 } 3760 3761 /* Some hubs forget their guids after they resume */ 3762 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, guid, 16); 3763 if (ret != 16) { 3764 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n"); 3765 goto out_fail; 3766 } 3767 3768 ret = drm_dp_check_mstb_guid(mgr->mst_primary, guid); 3769 if (ret) { 3770 drm_dbg_kms(mgr->dev, "check mstb failed - undocked during suspend?\n"); 3771 goto out_fail; 3772 } 3773 3774 /* 3775 * For the final step of resuming the topology, we need to bring the 3776 * state of our in-memory topology back into sync with reality. So, 3777 * restart the probing process as if we're probing a new hub 3778 */ 3779 queue_work(system_long_wq, &mgr->work); 3780 mutex_unlock(&mgr->lock); 3781 3782 if (sync) { 3783 drm_dbg_kms(mgr->dev, 3784 "Waiting for link probe work to finish re-syncing topology...\n"); 3785 flush_work(&mgr->work); 3786 } 3787 3788 return 0; 3789 3790 out_fail: 3791 mutex_unlock(&mgr->lock); 3792 return -1; 3793 } 3794 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume); 3795 3796 static void reset_msg_rx_state(struct drm_dp_sideband_msg_rx *msg) 3797 { 3798 memset(msg, 0, sizeof(*msg)); 3799 } 3800 3801 static bool 3802 drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up, 3803 struct drm_dp_mst_branch **mstb) 3804 { 3805 int len; 3806 u8 replyblock[32]; 3807 int replylen, curreply; 3808 int ret; 3809 u8 hdrlen; 3810 struct drm_dp_sideband_msg_hdr hdr; 3811 struct drm_dp_sideband_msg_rx *msg = 3812 up ? &mgr->up_req_recv : &mgr->down_rep_recv; 3813 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : 3814 DP_SIDEBAND_MSG_DOWN_REP_BASE; 3815 3816 if (!up) 3817 *mstb = NULL; 3818 3819 len = min(mgr->max_dpcd_transaction_bytes, 16); 3820 ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len); 3821 if (ret != len) { 3822 drm_dbg_kms(mgr->dev, "failed to read DPCD down rep %d %d\n", len, ret); 3823 return false; 3824 } 3825 3826 ret = drm_dp_decode_sideband_msg_hdr(mgr, &hdr, replyblock, len, &hdrlen); 3827 if (ret == false) { 3828 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 3829 1, replyblock, len, false); 3830 drm_dbg_kms(mgr->dev, "ERROR: failed header\n"); 3831 return false; 3832 } 3833 3834 if (!up) { 3835 /* Caller is responsible for giving back this reference */ 3836 *mstb = drm_dp_get_mst_branch_device(mgr, hdr.lct, hdr.rad); 3837 if (!*mstb) { 3838 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr.lct); 3839 return false; 3840 } 3841 } 3842 3843 if (!drm_dp_sideband_msg_set_header(msg, &hdr, hdrlen)) { 3844 drm_dbg_kms(mgr->dev, "sideband msg set header failed %d\n", replyblock[0]); 3845 return false; 3846 } 3847 3848 replylen = min(msg->curchunk_len, (u8)(len - hdrlen)); 3849 ret = drm_dp_sideband_append_payload(msg, replyblock + hdrlen, replylen); 3850 if (!ret) { 3851 drm_dbg_kms(mgr->dev, "sideband msg build failed %d\n", replyblock[0]); 3852 return false; 3853 } 3854 3855 replylen = msg->curchunk_len + msg->curchunk_hdrlen - len; 3856 curreply = len; 3857 while (replylen > 0) { 3858 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16); 3859 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply, 3860 replyblock, len); 3861 if (ret != len) { 3862 drm_dbg_kms(mgr->dev, "failed to read a chunk (len %d, ret %d)\n", 3863 len, ret); 3864 return false; 3865 } 3866 3867 ret = drm_dp_sideband_append_payload(msg, replyblock, len); 3868 if (!ret) { 3869 drm_dbg_kms(mgr->dev, "failed to build sideband msg\n"); 3870 return false; 3871 } 3872 3873 curreply += len; 3874 replylen -= len; 3875 } 3876 return true; 3877 } 3878 3879 static int get_msg_request_type(u8 data) 3880 { 3881 return data & 0x7f; 3882 } 3883 3884 static bool verify_rx_request_type(struct drm_dp_mst_topology_mgr *mgr, 3885 const struct drm_dp_sideband_msg_tx *txmsg, 3886 const struct drm_dp_sideband_msg_rx *rxmsg) 3887 { 3888 const struct drm_dp_sideband_msg_hdr *hdr = &rxmsg->initial_hdr; 3889 const struct drm_dp_mst_branch *mstb = txmsg->dst; 3890 int tx_req_type = get_msg_request_type(txmsg->msg[0]); 3891 int rx_req_type = get_msg_request_type(rxmsg->msg[0]); 3892 char rad_str[64]; 3893 3894 if (tx_req_type == rx_req_type) 3895 return true; 3896 3897 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, rad_str, sizeof(rad_str)); 3898 drm_dbg_kms(mgr->dev, 3899 "Got unexpected MST reply, mstb: %p seqno: %d lct: %d rad: %s rx_req_type: %s (%02x) != tx_req_type: %s (%02x)\n", 3900 mstb, hdr->seqno, mstb->lct, rad_str, 3901 drm_dp_mst_req_type_str(rx_req_type), rx_req_type, 3902 drm_dp_mst_req_type_str(tx_req_type), tx_req_type); 3903 3904 return false; 3905 } 3906 3907 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr) 3908 { 3909 struct drm_dp_sideband_msg_tx *txmsg; 3910 struct drm_dp_mst_branch *mstb = NULL; 3911 struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv; 3912 3913 if (!drm_dp_get_one_sb_msg(mgr, false, &mstb)) 3914 goto out_clear_reply; 3915 3916 /* Multi-packet message transmission, don't clear the reply */ 3917 if (!msg->have_eomt) 3918 goto out; 3919 3920 /* find the message */ 3921 mutex_lock(&mgr->qlock); 3922 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq, 3923 struct drm_dp_sideband_msg_tx, next); 3924 mutex_unlock(&mgr->qlock); 3925 3926 /* Were we actually expecting a response, and from this mstb? */ 3927 if (!txmsg || txmsg->dst != mstb) { 3928 struct drm_dp_sideband_msg_hdr *hdr; 3929 3930 hdr = &msg->initial_hdr; 3931 drm_dbg_kms(mgr->dev, "Got MST reply with no msg %p %d %d %02x %02x\n", 3932 mstb, hdr->seqno, hdr->lct, hdr->rad[0], msg->msg[0]); 3933 goto out_clear_reply; 3934 } 3935 3936 if (!verify_rx_request_type(mgr, txmsg, msg)) 3937 goto out_clear_reply; 3938 3939 drm_dp_sideband_parse_reply(mgr, msg, &txmsg->reply); 3940 3941 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3942 drm_dbg_kms(mgr->dev, 3943 "Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n", 3944 txmsg->reply.req_type, 3945 drm_dp_mst_req_type_str(txmsg->reply.req_type), 3946 txmsg->reply.u.nak.reason, 3947 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason), 3948 txmsg->reply.u.nak.nak_data); 3949 } 3950 3951 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx)); 3952 drm_dp_mst_topology_put_mstb(mstb); 3953 3954 mutex_lock(&mgr->qlock); 3955 txmsg->state = DRM_DP_SIDEBAND_TX_RX; 3956 list_del(&txmsg->next); 3957 mutex_unlock(&mgr->qlock); 3958 3959 wake_up_all(&mgr->tx_waitq); 3960 3961 return 0; 3962 3963 out_clear_reply: 3964 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx)); 3965 out: 3966 if (mstb) 3967 drm_dp_mst_topology_put_mstb(mstb); 3968 3969 return 0; 3970 } 3971 3972 static inline bool 3973 drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr, 3974 struct drm_dp_pending_up_req *up_req) 3975 { 3976 struct drm_dp_mst_branch *mstb = NULL; 3977 struct drm_dp_sideband_msg_req_body *msg = &up_req->msg; 3978 struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr; 3979 bool hotplug = false, dowork = false; 3980 3981 if (hdr->broadcast) { 3982 const u8 *guid = NULL; 3983 3984 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) 3985 guid = msg->u.conn_stat.guid; 3986 else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY) 3987 guid = msg->u.resource_stat.guid; 3988 3989 if (guid) 3990 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid); 3991 } else { 3992 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad); 3993 } 3994 3995 if (!mstb) { 3996 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr->lct); 3997 return false; 3998 } 3999 4000 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */ 4001 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) { 4002 dowork = drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat); 4003 hotplug = true; 4004 } 4005 4006 drm_dp_mst_topology_put_mstb(mstb); 4007 4008 if (dowork) 4009 queue_work(system_long_wq, &mgr->work); 4010 return hotplug; 4011 } 4012 4013 static void drm_dp_mst_up_req_work(struct work_struct *work) 4014 { 4015 struct drm_dp_mst_topology_mgr *mgr = 4016 container_of(work, struct drm_dp_mst_topology_mgr, 4017 up_req_work); 4018 struct drm_dp_pending_up_req *up_req; 4019 bool send_hotplug = false; 4020 4021 mutex_lock(&mgr->probe_lock); 4022 while (true) { 4023 mutex_lock(&mgr->up_req_lock); 4024 up_req = list_first_entry_or_null(&mgr->up_req_list, 4025 struct drm_dp_pending_up_req, 4026 next); 4027 if (up_req) 4028 list_del(&up_req->next); 4029 mutex_unlock(&mgr->up_req_lock); 4030 4031 if (!up_req) 4032 break; 4033 4034 send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req); 4035 kfree(up_req); 4036 } 4037 mutex_unlock(&mgr->probe_lock); 4038 4039 if (send_hotplug) 4040 drm_kms_helper_hotplug_event(mgr->dev); 4041 } 4042 4043 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr) 4044 { 4045 struct drm_dp_pending_up_req *up_req; 4046 4047 if (!drm_dp_get_one_sb_msg(mgr, true, NULL)) 4048 goto out; 4049 4050 if (!mgr->up_req_recv.have_eomt) 4051 return 0; 4052 4053 up_req = kzalloc(sizeof(*up_req), GFP_KERNEL); 4054 if (!up_req) 4055 return -ENOMEM; 4056 4057 INIT_LIST_HEAD(&up_req->next); 4058 4059 drm_dp_sideband_parse_req(mgr, &mgr->up_req_recv, &up_req->msg); 4060 4061 if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY && 4062 up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) { 4063 drm_dbg_kms(mgr->dev, "Received unknown up req type, ignoring: %x\n", 4064 up_req->msg.req_type); 4065 kfree(up_req); 4066 goto out; 4067 } 4068 4069 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type, 4070 false); 4071 4072 if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) { 4073 const struct drm_dp_connection_status_notify *conn_stat = 4074 &up_req->msg.u.conn_stat; 4075 bool handle_csn; 4076 4077 drm_dbg_kms(mgr->dev, "Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", 4078 conn_stat->port_number, 4079 conn_stat->legacy_device_plug_status, 4080 conn_stat->displayport_device_plug_status, 4081 conn_stat->message_capability_status, 4082 conn_stat->input_port, 4083 conn_stat->peer_device_type); 4084 4085 mutex_lock(&mgr->probe_lock); 4086 handle_csn = mgr->mst_primary->link_address_sent; 4087 mutex_unlock(&mgr->probe_lock); 4088 4089 if (!handle_csn) { 4090 drm_dbg_kms(mgr->dev, "Got CSN before finish topology probing. Skip it."); 4091 kfree(up_req); 4092 goto out; 4093 } 4094 } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) { 4095 const struct drm_dp_resource_status_notify *res_stat = 4096 &up_req->msg.u.resource_stat; 4097 4098 drm_dbg_kms(mgr->dev, "Got RSN: pn: %d avail_pbn %d\n", 4099 res_stat->port_number, 4100 res_stat->available_pbn); 4101 } 4102 4103 up_req->hdr = mgr->up_req_recv.initial_hdr; 4104 mutex_lock(&mgr->up_req_lock); 4105 list_add_tail(&up_req->next, &mgr->up_req_list); 4106 mutex_unlock(&mgr->up_req_lock); 4107 queue_work(system_long_wq, &mgr->up_req_work); 4108 4109 out: 4110 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 4111 return 0; 4112 } 4113 4114 static void update_msg_rx_state(struct drm_dp_mst_topology_mgr *mgr) 4115 { 4116 mutex_lock(&mgr->lock); 4117 if (mgr->reset_rx_state) { 4118 mgr->reset_rx_state = false; 4119 reset_msg_rx_state(&mgr->down_rep_recv); 4120 reset_msg_rx_state(&mgr->up_req_recv); 4121 } 4122 mutex_unlock(&mgr->lock); 4123 } 4124 4125 /** 4126 * drm_dp_mst_hpd_irq_handle_event() - MST hotplug IRQ handle MST event 4127 * @mgr: manager to notify irq for. 4128 * @esi: 4 bytes from SINK_COUNT_ESI 4129 * @ack: 4 bytes used to ack events starting from SINK_COUNT_ESI 4130 * @handled: whether the hpd interrupt was consumed or not 4131 * 4132 * This should be called from the driver when it detects a HPD IRQ, 4133 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The 4134 * topology manager will process the sideband messages received 4135 * as indicated in the DEVICE_SERVICE_IRQ_VECTOR_ESI0 and set the 4136 * corresponding flags that Driver has to ack the DP receiver later. 4137 * 4138 * Note that driver shall also call 4139 * drm_dp_mst_hpd_irq_send_new_request() if the 'handled' is set 4140 * after calling this function, to try to kick off a new request in 4141 * the queue if the previous message transaction is completed. 4142 * 4143 * See also: 4144 * drm_dp_mst_hpd_irq_send_new_request() 4145 */ 4146 int drm_dp_mst_hpd_irq_handle_event(struct drm_dp_mst_topology_mgr *mgr, const u8 *esi, 4147 u8 *ack, bool *handled) 4148 { 4149 int ret = 0; 4150 int sc; 4151 *handled = false; 4152 sc = DP_GET_SINK_COUNT(esi[0]); 4153 4154 if (sc != mgr->sink_count) { 4155 mgr->sink_count = sc; 4156 *handled = true; 4157 } 4158 4159 update_msg_rx_state(mgr); 4160 4161 if (esi[1] & DP_DOWN_REP_MSG_RDY) { 4162 ret = drm_dp_mst_handle_down_rep(mgr); 4163 *handled = true; 4164 ack[1] |= DP_DOWN_REP_MSG_RDY; 4165 } 4166 4167 if (esi[1] & DP_UP_REQ_MSG_RDY) { 4168 ret |= drm_dp_mst_handle_up_req(mgr); 4169 *handled = true; 4170 ack[1] |= DP_UP_REQ_MSG_RDY; 4171 } 4172 4173 return ret; 4174 } 4175 EXPORT_SYMBOL(drm_dp_mst_hpd_irq_handle_event); 4176 4177 /** 4178 * drm_dp_mst_hpd_irq_send_new_request() - MST hotplug IRQ kick off new request 4179 * @mgr: manager to notify irq for. 4180 * 4181 * This should be called from the driver when mst irq event is handled 4182 * and acked. Note that new down request should only be sent when 4183 * previous message transaction is completed. Source is not supposed to generate 4184 * interleaved message transactions. 4185 */ 4186 void drm_dp_mst_hpd_irq_send_new_request(struct drm_dp_mst_topology_mgr *mgr) 4187 { 4188 struct drm_dp_sideband_msg_tx *txmsg; 4189 bool kick = true; 4190 4191 mutex_lock(&mgr->qlock); 4192 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq, 4193 struct drm_dp_sideband_msg_tx, next); 4194 /* If last transaction is not completed yet*/ 4195 if (!txmsg || 4196 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND || 4197 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) 4198 kick = false; 4199 mutex_unlock(&mgr->qlock); 4200 4201 if (kick) 4202 drm_dp_mst_kick_tx(mgr); 4203 } 4204 EXPORT_SYMBOL(drm_dp_mst_hpd_irq_send_new_request); 4205 /** 4206 * drm_dp_mst_detect_port() - get connection status for an MST port 4207 * @connector: DRM connector for this port 4208 * @ctx: The acquisition context to use for grabbing locks 4209 * @mgr: manager for this port 4210 * @port: pointer to a port 4211 * 4212 * This returns the current connection state for a port. 4213 */ 4214 int 4215 drm_dp_mst_detect_port(struct drm_connector *connector, 4216 struct drm_modeset_acquire_ctx *ctx, 4217 struct drm_dp_mst_topology_mgr *mgr, 4218 struct drm_dp_mst_port *port) 4219 { 4220 int ret; 4221 4222 /* we need to search for the port in the mgr in case it's gone */ 4223 port = drm_dp_mst_topology_get_port_validated(mgr, port); 4224 if (!port) 4225 return connector_status_disconnected; 4226 4227 ret = drm_modeset_lock(&mgr->base.lock, ctx); 4228 if (ret) 4229 goto out; 4230 4231 ret = connector_status_disconnected; 4232 4233 if (!port->ddps) 4234 goto out; 4235 4236 switch (port->pdt) { 4237 case DP_PEER_DEVICE_NONE: 4238 break; 4239 case DP_PEER_DEVICE_MST_BRANCHING: 4240 if (!port->mcs) 4241 ret = connector_status_connected; 4242 break; 4243 4244 case DP_PEER_DEVICE_SST_SINK: 4245 ret = connector_status_connected; 4246 /* for logical ports - cache the EDID */ 4247 if (port->port_num >= DP_MST_LOGICAL_PORT_0 && !port->cached_edid) 4248 port->cached_edid = drm_edid_read_ddc(connector, &port->aux.ddc); 4249 break; 4250 case DP_PEER_DEVICE_DP_LEGACY_CONV: 4251 if (port->ldps) 4252 ret = connector_status_connected; 4253 break; 4254 } 4255 out: 4256 drm_dp_mst_topology_put_port(port); 4257 return ret; 4258 } 4259 EXPORT_SYMBOL(drm_dp_mst_detect_port); 4260 4261 /** 4262 * drm_dp_mst_edid_read() - get EDID for an MST port 4263 * @connector: toplevel connector to get EDID for 4264 * @mgr: manager for this port 4265 * @port: unverified pointer to a port. 4266 * 4267 * This returns an EDID for the port connected to a connector, 4268 * It validates the pointer still exists so the caller doesn't require a 4269 * reference. 4270 */ 4271 const struct drm_edid *drm_dp_mst_edid_read(struct drm_connector *connector, 4272 struct drm_dp_mst_topology_mgr *mgr, 4273 struct drm_dp_mst_port *port) 4274 { 4275 const struct drm_edid *drm_edid; 4276 4277 /* we need to search for the port in the mgr in case it's gone */ 4278 port = drm_dp_mst_topology_get_port_validated(mgr, port); 4279 if (!port) 4280 return NULL; 4281 4282 if (port->cached_edid) 4283 drm_edid = drm_edid_dup(port->cached_edid); 4284 else 4285 drm_edid = drm_edid_read_ddc(connector, &port->aux.ddc); 4286 4287 drm_dp_mst_topology_put_port(port); 4288 4289 return drm_edid; 4290 } 4291 EXPORT_SYMBOL(drm_dp_mst_edid_read); 4292 4293 /** 4294 * drm_dp_mst_get_edid() - get EDID for an MST port 4295 * @connector: toplevel connector to get EDID for 4296 * @mgr: manager for this port 4297 * @port: unverified pointer to a port. 4298 * 4299 * This function is deprecated; please use drm_dp_mst_edid_read() instead. 4300 * 4301 * This returns an EDID for the port connected to a connector, 4302 * It validates the pointer still exists so the caller doesn't require a 4303 * reference. 4304 */ 4305 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, 4306 struct drm_dp_mst_topology_mgr *mgr, 4307 struct drm_dp_mst_port *port) 4308 { 4309 const struct drm_edid *drm_edid; 4310 struct edid *edid; 4311 4312 drm_edid = drm_dp_mst_edid_read(connector, mgr, port); 4313 4314 edid = drm_edid_duplicate(drm_edid_raw(drm_edid)); 4315 4316 drm_edid_free(drm_edid); 4317 4318 return edid; 4319 } 4320 EXPORT_SYMBOL(drm_dp_mst_get_edid); 4321 4322 /** 4323 * drm_dp_atomic_find_time_slots() - Find and add time slots to the state 4324 * @state: global atomic state 4325 * @mgr: MST topology manager for the port 4326 * @port: port to find time slots for 4327 * @pbn: bandwidth required for the mode in PBN 4328 * 4329 * Allocates time slots to @port, replacing any previous time slot allocations it may 4330 * have had. Any atomic drivers which support MST must call this function in 4331 * their &drm_encoder_helper_funcs.atomic_check() callback unconditionally to 4332 * change the current time slot allocation for the new state, and ensure the MST 4333 * atomic state is added whenever the state of payloads in the topology changes. 4334 * 4335 * Allocations set by this function are not checked against the bandwidth 4336 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check(). 4337 * 4338 * Additionally, it is OK to call this function multiple times on the same 4339 * @port as needed. It is not OK however, to call this function and 4340 * drm_dp_atomic_release_time_slots() in the same atomic check phase. 4341 * 4342 * See also: 4343 * drm_dp_atomic_release_time_slots() 4344 * drm_dp_mst_atomic_check() 4345 * 4346 * Returns: 4347 * Total slots in the atomic state assigned for this port, or a negative error 4348 * code if the port no longer exists 4349 */ 4350 int drm_dp_atomic_find_time_slots(struct drm_atomic_state *state, 4351 struct drm_dp_mst_topology_mgr *mgr, 4352 struct drm_dp_mst_port *port, int pbn) 4353 { 4354 struct drm_dp_mst_topology_state *topology_state; 4355 struct drm_dp_mst_atomic_payload *payload = NULL; 4356 struct drm_connector_state *conn_state; 4357 int prev_slots = 0, prev_bw = 0, req_slots; 4358 4359 topology_state = drm_atomic_get_mst_topology_state(state, mgr); 4360 if (IS_ERR(topology_state)) 4361 return PTR_ERR(topology_state); 4362 4363 conn_state = drm_atomic_get_new_connector_state(state, port->connector); 4364 topology_state->pending_crtc_mask |= drm_crtc_mask(conn_state->crtc); 4365 4366 /* Find the current allocation for this port, if any */ 4367 payload = drm_atomic_get_mst_payload_state(topology_state, port); 4368 if (payload) { 4369 prev_slots = payload->time_slots; 4370 prev_bw = payload->pbn; 4371 4372 /* 4373 * This should never happen, unless the driver tries 4374 * releasing and allocating the same timeslot allocation, 4375 * which is an error 4376 */ 4377 if (drm_WARN_ON(mgr->dev, payload->delete)) { 4378 drm_err(mgr->dev, 4379 "cannot allocate and release time slots on [MST PORT:%p] in the same state\n", 4380 port); 4381 return -EINVAL; 4382 } 4383 } 4384 4385 req_slots = DIV_ROUND_UP(pbn, topology_state->pbn_div); 4386 4387 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] TU %d -> %d\n", 4388 port->connector->base.id, port->connector->name, 4389 port, prev_slots, req_slots); 4390 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n", 4391 port->connector->base.id, port->connector->name, 4392 port, prev_bw, pbn); 4393 4394 /* Add the new allocation to the state, note the VCPI isn't assigned until the end */ 4395 if (!payload) { 4396 payload = kzalloc(sizeof(*payload), GFP_KERNEL); 4397 if (!payload) 4398 return -ENOMEM; 4399 4400 drm_dp_mst_get_port_malloc(port); 4401 payload->port = port; 4402 payload->vc_start_slot = -1; 4403 list_add(&payload->next, &topology_state->payloads); 4404 } 4405 payload->time_slots = req_slots; 4406 payload->pbn = pbn; 4407 4408 return req_slots; 4409 } 4410 EXPORT_SYMBOL(drm_dp_atomic_find_time_slots); 4411 4412 /** 4413 * drm_dp_atomic_release_time_slots() - Release allocated time slots 4414 * @state: global atomic state 4415 * @mgr: MST topology manager for the port 4416 * @port: The port to release the time slots from 4417 * 4418 * Releases any time slots that have been allocated to a port in the atomic 4419 * state. Any atomic drivers which support MST must call this function 4420 * unconditionally in their &drm_connector_helper_funcs.atomic_check() callback. 4421 * This helper will check whether time slots would be released by the new state and 4422 * respond accordingly, along with ensuring the MST state is always added to the 4423 * atomic state whenever a new state would modify the state of payloads on the 4424 * topology. 4425 * 4426 * It is OK to call this even if @port has been removed from the system. 4427 * Additionally, it is OK to call this function multiple times on the same 4428 * @port as needed. It is not OK however, to call this function and 4429 * drm_dp_atomic_find_time_slots() on the same @port in a single atomic check 4430 * phase. 4431 * 4432 * See also: 4433 * drm_dp_atomic_find_time_slots() 4434 * drm_dp_mst_atomic_check() 4435 * 4436 * Returns: 4437 * 0 on success, negative error code otherwise 4438 */ 4439 int drm_dp_atomic_release_time_slots(struct drm_atomic_state *state, 4440 struct drm_dp_mst_topology_mgr *mgr, 4441 struct drm_dp_mst_port *port) 4442 { 4443 struct drm_dp_mst_topology_state *topology_state; 4444 struct drm_dp_mst_atomic_payload *payload; 4445 struct drm_connector_state *old_conn_state, *new_conn_state; 4446 bool update_payload = true; 4447 4448 old_conn_state = drm_atomic_get_old_connector_state(state, port->connector); 4449 if (!old_conn_state->crtc) 4450 return 0; 4451 4452 /* If the CRTC isn't disabled by this state, don't release it's payload */ 4453 new_conn_state = drm_atomic_get_new_connector_state(state, port->connector); 4454 if (new_conn_state->crtc) { 4455 struct drm_crtc_state *crtc_state = 4456 drm_atomic_get_new_crtc_state(state, new_conn_state->crtc); 4457 4458 /* No modeset means no payload changes, so it's safe to not pull in the MST state */ 4459 if (!crtc_state || !drm_atomic_crtc_needs_modeset(crtc_state)) 4460 return 0; 4461 4462 if (!crtc_state->mode_changed && !crtc_state->connectors_changed) 4463 update_payload = false; 4464 } 4465 4466 topology_state = drm_atomic_get_mst_topology_state(state, mgr); 4467 if (IS_ERR(topology_state)) 4468 return PTR_ERR(topology_state); 4469 4470 topology_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc); 4471 if (!update_payload) 4472 return 0; 4473 4474 payload = drm_atomic_get_mst_payload_state(topology_state, port); 4475 if (WARN_ON(!payload)) { 4476 drm_err(mgr->dev, "No payload for [MST PORT:%p] found in mst state %p\n", 4477 port, &topology_state->base); 4478 return -EINVAL; 4479 } 4480 4481 if (new_conn_state->crtc) 4482 return 0; 4483 4484 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] TU %d -> 0\n", port, payload->time_slots); 4485 if (!payload->delete) { 4486 payload->pbn = 0; 4487 payload->delete = true; 4488 topology_state->payload_mask &= ~BIT(payload->vcpi - 1); 4489 } 4490 4491 return 0; 4492 } 4493 EXPORT_SYMBOL(drm_dp_atomic_release_time_slots); 4494 4495 /** 4496 * drm_dp_mst_atomic_setup_commit() - setup_commit hook for MST helpers 4497 * @state: global atomic state 4498 * 4499 * This function saves all of the &drm_crtc_commit structs in an atomic state that touch any CRTCs 4500 * currently assigned to an MST topology. Drivers must call this hook from their 4501 * &drm_mode_config_helper_funcs.atomic_commit_setup hook. 4502 * 4503 * Returns: 4504 * 0 if all CRTC commits were retrieved successfully, negative error code otherwise 4505 */ 4506 int drm_dp_mst_atomic_setup_commit(struct drm_atomic_state *state) 4507 { 4508 struct drm_dp_mst_topology_mgr *mgr; 4509 struct drm_dp_mst_topology_state *mst_state; 4510 struct drm_crtc *crtc; 4511 struct drm_crtc_state *crtc_state; 4512 int i, j, commit_idx, num_commit_deps; 4513 4514 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { 4515 if (!mst_state->pending_crtc_mask) 4516 continue; 4517 4518 num_commit_deps = hweight32(mst_state->pending_crtc_mask); 4519 mst_state->commit_deps = kmalloc_array(num_commit_deps, 4520 sizeof(*mst_state->commit_deps), GFP_KERNEL); 4521 if (!mst_state->commit_deps) 4522 return -ENOMEM; 4523 mst_state->num_commit_deps = num_commit_deps; 4524 4525 commit_idx = 0; 4526 for_each_new_crtc_in_state(state, crtc, crtc_state, j) { 4527 if (mst_state->pending_crtc_mask & drm_crtc_mask(crtc)) { 4528 mst_state->commit_deps[commit_idx++] = 4529 drm_crtc_commit_get(crtc_state->commit); 4530 } 4531 } 4532 } 4533 4534 return 0; 4535 } 4536 EXPORT_SYMBOL(drm_dp_mst_atomic_setup_commit); 4537 4538 /** 4539 * drm_dp_mst_atomic_wait_for_dependencies() - Wait for all pending commits on MST topologies, 4540 * prepare new MST state for commit 4541 * @state: global atomic state 4542 * 4543 * Goes through any MST topologies in this atomic state, and waits for any pending commits which 4544 * touched CRTCs that were/are on an MST topology to be programmed to hardware and flipped to before 4545 * returning. This is to prevent multiple non-blocking commits affecting an MST topology from racing 4546 * with eachother by forcing them to be executed sequentially in situations where the only resources 4547 * the modeset objects in these commits share are an MST topology. 4548 * 4549 * This function also prepares the new MST state for commit by performing some state preparation 4550 * which can't be done until this point, such as reading back the final VC start slots (which are 4551 * determined at commit-time) from the previous state. 4552 * 4553 * All MST drivers must call this function after calling drm_atomic_helper_wait_for_dependencies(), 4554 * or whatever their equivalent of that is. 4555 */ 4556 void drm_dp_mst_atomic_wait_for_dependencies(struct drm_atomic_state *state) 4557 { 4558 struct drm_dp_mst_topology_state *old_mst_state, *new_mst_state; 4559 struct drm_dp_mst_topology_mgr *mgr; 4560 struct drm_dp_mst_atomic_payload *old_payload, *new_payload; 4561 int i, j, ret; 4562 4563 for_each_oldnew_mst_mgr_in_state(state, mgr, old_mst_state, new_mst_state, i) { 4564 for (j = 0; j < old_mst_state->num_commit_deps; j++) { 4565 ret = drm_crtc_commit_wait(old_mst_state->commit_deps[j]); 4566 if (ret < 0) 4567 drm_err(state->dev, "Failed to wait for %s: %d\n", 4568 old_mst_state->commit_deps[j]->crtc->name, ret); 4569 } 4570 4571 /* Now that previous state is committed, it's safe to copy over the start slot 4572 * assignments 4573 */ 4574 list_for_each_entry(old_payload, &old_mst_state->payloads, next) { 4575 if (old_payload->delete) 4576 continue; 4577 4578 new_payload = drm_atomic_get_mst_payload_state(new_mst_state, 4579 old_payload->port); 4580 new_payload->vc_start_slot = old_payload->vc_start_slot; 4581 } 4582 } 4583 } 4584 EXPORT_SYMBOL(drm_dp_mst_atomic_wait_for_dependencies); 4585 4586 /** 4587 * drm_dp_mst_root_conn_atomic_check() - Serialize CRTC commits on MST-capable connectors operating 4588 * in SST mode 4589 * @new_conn_state: The new connector state of the &drm_connector 4590 * @mgr: The MST topology manager for the &drm_connector 4591 * 4592 * Since MST uses fake &drm_encoder structs, the generic atomic modesetting code isn't able to 4593 * serialize non-blocking commits happening on the real DP connector of an MST topology switching 4594 * into/away from MST mode - as the CRTC on the real DP connector and the CRTCs on the connector's 4595 * MST topology will never share the same &drm_encoder. 4596 * 4597 * This function takes care of this serialization issue, by checking a root MST connector's atomic 4598 * state to determine if it is about to have a modeset - and then pulling in the MST topology state 4599 * if so, along with adding any relevant CRTCs to &drm_dp_mst_topology_state.pending_crtc_mask. 4600 * 4601 * Drivers implementing MST must call this function from the 4602 * &drm_connector_helper_funcs.atomic_check hook of any physical DP &drm_connector capable of 4603 * driving MST sinks. 4604 * 4605 * Returns: 4606 * 0 on success, negative error code otherwise 4607 */ 4608 int drm_dp_mst_root_conn_atomic_check(struct drm_connector_state *new_conn_state, 4609 struct drm_dp_mst_topology_mgr *mgr) 4610 { 4611 struct drm_atomic_state *state = new_conn_state->state; 4612 struct drm_connector_state *old_conn_state = 4613 drm_atomic_get_old_connector_state(state, new_conn_state->connector); 4614 struct drm_crtc_state *crtc_state; 4615 struct drm_dp_mst_topology_state *mst_state = NULL; 4616 4617 if (new_conn_state->crtc) { 4618 crtc_state = drm_atomic_get_new_crtc_state(state, new_conn_state->crtc); 4619 if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) { 4620 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 4621 if (IS_ERR(mst_state)) 4622 return PTR_ERR(mst_state); 4623 4624 mst_state->pending_crtc_mask |= drm_crtc_mask(new_conn_state->crtc); 4625 } 4626 } 4627 4628 if (old_conn_state->crtc) { 4629 crtc_state = drm_atomic_get_new_crtc_state(state, old_conn_state->crtc); 4630 if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) { 4631 if (!mst_state) { 4632 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 4633 if (IS_ERR(mst_state)) 4634 return PTR_ERR(mst_state); 4635 } 4636 4637 mst_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc); 4638 } 4639 } 4640 4641 return 0; 4642 } 4643 EXPORT_SYMBOL(drm_dp_mst_root_conn_atomic_check); 4644 4645 /** 4646 * drm_dp_mst_update_slots() - updates the slot info depending on the DP ecoding format 4647 * @mst_state: mst_state to update 4648 * @link_encoding_cap: the ecoding format on the link 4649 */ 4650 void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap) 4651 { 4652 if (link_encoding_cap == DP_CAP_ANSI_128B132B) { 4653 mst_state->total_avail_slots = 64; 4654 mst_state->start_slot = 0; 4655 } else { 4656 mst_state->total_avail_slots = 63; 4657 mst_state->start_slot = 1; 4658 } 4659 4660 DRM_DEBUG_KMS("%s encoding format on mst_state 0x%p\n", 4661 (link_encoding_cap == DP_CAP_ANSI_128B132B) ? "128b/132b":"8b/10b", 4662 mst_state); 4663 } 4664 EXPORT_SYMBOL(drm_dp_mst_update_slots); 4665 4666 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, 4667 int id, u8 start_slot, u8 num_slots) 4668 { 4669 u8 payload_alloc[3], status; 4670 int ret; 4671 int retries = 0; 4672 4673 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, 4674 DP_PAYLOAD_TABLE_UPDATED); 4675 4676 payload_alloc[0] = id; 4677 payload_alloc[1] = start_slot; 4678 payload_alloc[2] = num_slots; 4679 4680 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3); 4681 if (ret != 3) { 4682 drm_dbg_kms(mgr->dev, "failed to write payload allocation %d\n", ret); 4683 goto fail; 4684 } 4685 4686 retry: 4687 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 4688 if (ret < 0) { 4689 drm_dbg_kms(mgr->dev, "failed to read payload table status %d\n", ret); 4690 goto fail; 4691 } 4692 4693 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) { 4694 retries++; 4695 if (retries < 20) { 4696 usleep_range(10000, 20000); 4697 goto retry; 4698 } 4699 drm_dbg_kms(mgr->dev, "status not set after read payload table status %d\n", 4700 status); 4701 ret = -EINVAL; 4702 goto fail; 4703 } 4704 ret = 0; 4705 fail: 4706 return ret; 4707 } 4708 4709 static int do_get_act_status(struct drm_dp_aux *aux) 4710 { 4711 int ret; 4712 u8 status; 4713 4714 ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 4715 if (ret < 0) 4716 return ret; 4717 4718 return status; 4719 } 4720 4721 /** 4722 * drm_dp_check_act_status() - Polls for ACT handled status. 4723 * @mgr: manager to use 4724 * 4725 * Tries waiting for the MST hub to finish updating it's payload table by 4726 * polling for the ACT handled bit for up to 3 seconds (yes-some hubs really 4727 * take that long). 4728 * 4729 * Returns: 4730 * 0 if the ACT was handled in time, negative error code on failure. 4731 */ 4732 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr) 4733 { 4734 /* 4735 * There doesn't seem to be any recommended retry count or timeout in 4736 * the MST specification. Since some hubs have been observed to take 4737 * over 1 second to update their payload allocations under certain 4738 * conditions, we use a rather large timeout value. 4739 */ 4740 const int timeout_ms = 3000; 4741 int ret, status; 4742 4743 ret = readx_poll_timeout(do_get_act_status, mgr->aux, status, 4744 status & DP_PAYLOAD_ACT_HANDLED || status < 0, 4745 200, timeout_ms * USEC_PER_MSEC); 4746 if (ret < 0 && status >= 0) { 4747 drm_err(mgr->dev, "Failed to get ACT after %dms, last status: %02x\n", 4748 timeout_ms, status); 4749 return -EINVAL; 4750 } else if (status < 0) { 4751 /* 4752 * Failure here isn't unexpected - the hub may have 4753 * just been unplugged 4754 */ 4755 drm_dbg_kms(mgr->dev, "Failed to read payload table status: %d\n", status); 4756 return status; 4757 } 4758 4759 return 0; 4760 } 4761 EXPORT_SYMBOL(drm_dp_check_act_status); 4762 4763 /** 4764 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode. 4765 * @clock: dot clock 4766 * @bpp: bpp as .4 binary fixed point 4767 * 4768 * This uses the formula in the spec to calculate the PBN value for a mode. 4769 */ 4770 int drm_dp_calc_pbn_mode(int clock, int bpp) 4771 { 4772 /* 4773 * margin 5300ppm + 300ppm ~ 0.6% as per spec, factor is 1.006 4774 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on 4775 * common multiplier to render an integer PBN for all link rate/lane 4776 * counts combinations 4777 * calculate 4778 * peak_kbps *= (1006/1000) 4779 * peak_kbps *= (64/54) 4780 * peak_kbps *= 8 convert to bytes 4781 */ 4782 return DIV_ROUND_UP_ULL(mul_u32_u32(clock * bpp, 64 * 1006 >> 4), 4783 1000 * 8 * 54 * 1000); 4784 } 4785 EXPORT_SYMBOL(drm_dp_calc_pbn_mode); 4786 4787 /* we want to kick the TX after we've ack the up/down IRQs. */ 4788 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr) 4789 { 4790 queue_work(system_long_wq, &mgr->tx_work); 4791 } 4792 4793 /* 4794 * Helper function for parsing DP device types into convenient strings 4795 * for use with dp_mst_topology 4796 */ 4797 static const char *pdt_to_string(u8 pdt) 4798 { 4799 switch (pdt) { 4800 case DP_PEER_DEVICE_NONE: 4801 return "NONE"; 4802 case DP_PEER_DEVICE_SOURCE_OR_SST: 4803 return "SOURCE OR SST"; 4804 case DP_PEER_DEVICE_MST_BRANCHING: 4805 return "MST BRANCHING"; 4806 case DP_PEER_DEVICE_SST_SINK: 4807 return "SST SINK"; 4808 case DP_PEER_DEVICE_DP_LEGACY_CONV: 4809 return "DP LEGACY CONV"; 4810 default: 4811 return "ERR"; 4812 } 4813 } 4814 4815 static void drm_dp_mst_dump_mstb(struct seq_file *m, 4816 struct drm_dp_mst_branch *mstb) 4817 { 4818 struct drm_dp_mst_port *port; 4819 int tabs = mstb->lct; 4820 char prefix[10]; 4821 int i; 4822 4823 for (i = 0; i < tabs; i++) 4824 prefix[i] = '\t'; 4825 prefix[i] = '\0'; 4826 4827 seq_printf(m, "%smstb - [%p]: num_ports: %d\n", prefix, mstb, mstb->num_ports); 4828 list_for_each_entry(port, &mstb->ports, next) { 4829 seq_printf(m, "%sport %d - [%p] (%s - %s): ddps: %d, ldps: %d, sdp: %d/%d, fec: %s, conn: %p\n", 4830 prefix, 4831 port->port_num, 4832 port, 4833 port->input ? "input" : "output", 4834 pdt_to_string(port->pdt), 4835 port->ddps, 4836 port->ldps, 4837 port->num_sdp_streams, 4838 port->num_sdp_stream_sinks, 4839 port->fec_capable ? "true" : "false", 4840 port->connector); 4841 if (port->mstb) 4842 drm_dp_mst_dump_mstb(m, port->mstb); 4843 } 4844 } 4845 4846 #define DP_PAYLOAD_TABLE_SIZE 64 4847 4848 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, 4849 char *buf) 4850 { 4851 int i; 4852 4853 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) { 4854 if (drm_dp_dpcd_read(mgr->aux, 4855 DP_PAYLOAD_TABLE_UPDATE_STATUS + i, 4856 &buf[i], 16) != 16) 4857 return false; 4858 } 4859 return true; 4860 } 4861 4862 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr, 4863 struct drm_dp_mst_port *port, char *name, 4864 int namelen) 4865 { 4866 struct edid *mst_edid; 4867 4868 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port); 4869 drm_edid_get_monitor_name(mst_edid, name, namelen); 4870 kfree(mst_edid); 4871 } 4872 4873 /** 4874 * drm_dp_mst_dump_topology(): dump topology to seq file. 4875 * @m: seq_file to dump output to 4876 * @mgr: manager to dump current topology for. 4877 * 4878 * helper to dump MST topology to a seq file for debugfs. 4879 */ 4880 void drm_dp_mst_dump_topology(struct seq_file *m, 4881 struct drm_dp_mst_topology_mgr *mgr) 4882 { 4883 struct drm_dp_mst_topology_state *state; 4884 struct drm_dp_mst_atomic_payload *payload; 4885 int i, ret; 4886 4887 mutex_lock(&mgr->lock); 4888 if (mgr->mst_primary) 4889 drm_dp_mst_dump_mstb(m, mgr->mst_primary); 4890 4891 /* dump VCPIs */ 4892 mutex_unlock(&mgr->lock); 4893 4894 ret = drm_modeset_lock_single_interruptible(&mgr->base.lock); 4895 if (ret < 0) 4896 return; 4897 4898 state = to_drm_dp_mst_topology_state(mgr->base.state); 4899 seq_printf(m, "\n*** Atomic state info ***\n"); 4900 seq_printf(m, "payload_mask: %x, max_payloads: %d, start_slot: %u, pbn_div: %d\n", 4901 state->payload_mask, mgr->max_payloads, state->start_slot, state->pbn_div); 4902 4903 seq_printf(m, "\n| idx | port | vcpi | slots | pbn | dsc | sink name |\n"); 4904 for (i = 0; i < mgr->max_payloads; i++) { 4905 list_for_each_entry(payload, &state->payloads, next) { 4906 char name[14]; 4907 4908 if (payload->vcpi != i || payload->delete) 4909 continue; 4910 4911 fetch_monitor_name(mgr, payload->port, name, sizeof(name)); 4912 seq_printf(m, " %5d %6d %6d %02d - %02d %5d %5s %19s\n", 4913 i, 4914 payload->port->port_num, 4915 payload->vcpi, 4916 payload->vc_start_slot, 4917 payload->vc_start_slot + payload->time_slots - 1, 4918 payload->pbn, 4919 payload->dsc_enabled ? "Y" : "N", 4920 (*name != 0) ? name : "Unknown"); 4921 } 4922 } 4923 4924 seq_printf(m, "\n*** DPCD Info ***\n"); 4925 mutex_lock(&mgr->lock); 4926 if (mgr->mst_primary) { 4927 u8 buf[DP_PAYLOAD_TABLE_SIZE]; 4928 int ret; 4929 4930 if (drm_dp_read_dpcd_caps(mgr->aux, buf) < 0) { 4931 seq_printf(m, "dpcd read failed\n"); 4932 goto out; 4933 } 4934 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf); 4935 4936 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2); 4937 if (ret != 2) { 4938 seq_printf(m, "faux/mst read failed\n"); 4939 goto out; 4940 } 4941 seq_printf(m, "faux/mst: %*ph\n", 2, buf); 4942 4943 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1); 4944 if (ret != 1) { 4945 seq_printf(m, "mst ctrl read failed\n"); 4946 goto out; 4947 } 4948 seq_printf(m, "mst ctrl: %*ph\n", 1, buf); 4949 4950 /* dump the standard OUI branch header */ 4951 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE); 4952 if (ret != DP_BRANCH_OUI_HEADER_SIZE) { 4953 seq_printf(m, "branch oui read failed\n"); 4954 goto out; 4955 } 4956 seq_printf(m, "branch oui: %*phN devid: ", 3, buf); 4957 4958 for (i = 0x3; i < 0x8 && buf[i]; i++) 4959 seq_printf(m, "%c", buf[i]); 4960 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n", 4961 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]); 4962 if (dump_dp_payload_table(mgr, buf)) 4963 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf); 4964 } 4965 4966 out: 4967 mutex_unlock(&mgr->lock); 4968 drm_modeset_unlock(&mgr->base.lock); 4969 } 4970 EXPORT_SYMBOL(drm_dp_mst_dump_topology); 4971 4972 static void drm_dp_tx_work(struct work_struct *work) 4973 { 4974 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work); 4975 4976 mutex_lock(&mgr->qlock); 4977 if (!list_empty(&mgr->tx_msg_downq)) 4978 process_single_down_tx_qlock(mgr); 4979 mutex_unlock(&mgr->qlock); 4980 } 4981 4982 static inline void 4983 drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port) 4984 { 4985 drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs); 4986 4987 if (port->connector) { 4988 drm_connector_unregister(port->connector); 4989 drm_connector_put(port->connector); 4990 } 4991 4992 drm_dp_mst_put_port_malloc(port); 4993 } 4994 4995 static inline void 4996 drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb) 4997 { 4998 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 4999 struct drm_dp_mst_port *port, *port_tmp; 5000 struct drm_dp_sideband_msg_tx *txmsg, *txmsg_tmp; 5001 bool wake_tx = false; 5002 5003 mutex_lock(&mgr->lock); 5004 list_for_each_entry_safe(port, port_tmp, &mstb->ports, next) { 5005 list_del(&port->next); 5006 drm_dp_mst_topology_put_port(port); 5007 } 5008 mutex_unlock(&mgr->lock); 5009 5010 /* drop any tx slot msg */ 5011 mutex_lock(&mstb->mgr->qlock); 5012 list_for_each_entry_safe(txmsg, txmsg_tmp, &mgr->tx_msg_downq, next) { 5013 if (txmsg->dst != mstb) 5014 continue; 5015 5016 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 5017 list_del(&txmsg->next); 5018 wake_tx = true; 5019 } 5020 mutex_unlock(&mstb->mgr->qlock); 5021 5022 if (wake_tx) 5023 wake_up_all(&mstb->mgr->tx_waitq); 5024 5025 drm_dp_mst_put_mstb_malloc(mstb); 5026 } 5027 5028 static void drm_dp_delayed_destroy_work(struct work_struct *work) 5029 { 5030 struct drm_dp_mst_topology_mgr *mgr = 5031 container_of(work, struct drm_dp_mst_topology_mgr, 5032 delayed_destroy_work); 5033 bool send_hotplug = false, go_again; 5034 5035 /* 5036 * Not a regular list traverse as we have to drop the destroy 5037 * connector lock before destroying the mstb/port, to avoid AB->BA 5038 * ordering between this lock and the config mutex. 5039 */ 5040 do { 5041 go_again = false; 5042 5043 for (;;) { 5044 struct drm_dp_mst_branch *mstb; 5045 5046 mutex_lock(&mgr->delayed_destroy_lock); 5047 mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list, 5048 struct drm_dp_mst_branch, 5049 destroy_next); 5050 if (mstb) 5051 list_del(&mstb->destroy_next); 5052 mutex_unlock(&mgr->delayed_destroy_lock); 5053 5054 if (!mstb) 5055 break; 5056 5057 drm_dp_delayed_destroy_mstb(mstb); 5058 go_again = true; 5059 } 5060 5061 for (;;) { 5062 struct drm_dp_mst_port *port; 5063 5064 mutex_lock(&mgr->delayed_destroy_lock); 5065 port = list_first_entry_or_null(&mgr->destroy_port_list, 5066 struct drm_dp_mst_port, 5067 next); 5068 if (port) 5069 list_del(&port->next); 5070 mutex_unlock(&mgr->delayed_destroy_lock); 5071 5072 if (!port) 5073 break; 5074 5075 drm_dp_delayed_destroy_port(port); 5076 send_hotplug = true; 5077 go_again = true; 5078 } 5079 } while (go_again); 5080 5081 if (send_hotplug) 5082 drm_kms_helper_hotplug_event(mgr->dev); 5083 } 5084 5085 static struct drm_private_state * 5086 drm_dp_mst_duplicate_state(struct drm_private_obj *obj) 5087 { 5088 struct drm_dp_mst_topology_state *state, *old_state = 5089 to_dp_mst_topology_state(obj->state); 5090 struct drm_dp_mst_atomic_payload *pos, *payload; 5091 5092 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL); 5093 if (!state) 5094 return NULL; 5095 5096 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base); 5097 5098 INIT_LIST_HEAD(&state->payloads); 5099 state->commit_deps = NULL; 5100 state->num_commit_deps = 0; 5101 state->pending_crtc_mask = 0; 5102 5103 list_for_each_entry(pos, &old_state->payloads, next) { 5104 /* Prune leftover freed timeslot allocations */ 5105 if (pos->delete) 5106 continue; 5107 5108 payload = kmemdup(pos, sizeof(*payload), GFP_KERNEL); 5109 if (!payload) 5110 goto fail; 5111 5112 drm_dp_mst_get_port_malloc(payload->port); 5113 list_add(&payload->next, &state->payloads); 5114 } 5115 5116 return &state->base; 5117 5118 fail: 5119 list_for_each_entry_safe(pos, payload, &state->payloads, next) { 5120 drm_dp_mst_put_port_malloc(pos->port); 5121 kfree(pos); 5122 } 5123 kfree(state); 5124 5125 return NULL; 5126 } 5127 5128 static void drm_dp_mst_destroy_state(struct drm_private_obj *obj, 5129 struct drm_private_state *state) 5130 { 5131 struct drm_dp_mst_topology_state *mst_state = 5132 to_dp_mst_topology_state(state); 5133 struct drm_dp_mst_atomic_payload *pos, *tmp; 5134 int i; 5135 5136 list_for_each_entry_safe(pos, tmp, &mst_state->payloads, next) { 5137 /* We only keep references to ports with active payloads */ 5138 if (!pos->delete) 5139 drm_dp_mst_put_port_malloc(pos->port); 5140 kfree(pos); 5141 } 5142 5143 for (i = 0; i < mst_state->num_commit_deps; i++) 5144 drm_crtc_commit_put(mst_state->commit_deps[i]); 5145 5146 kfree(mst_state->commit_deps); 5147 kfree(mst_state); 5148 } 5149 5150 static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port, 5151 struct drm_dp_mst_branch *branch) 5152 { 5153 while (port->parent) { 5154 if (port->parent == branch) 5155 return true; 5156 5157 if (port->parent->port_parent) 5158 port = port->parent->port_parent; 5159 else 5160 break; 5161 } 5162 return false; 5163 } 5164 5165 static int 5166 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, 5167 struct drm_dp_mst_topology_state *state); 5168 5169 static int 5170 drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb, 5171 struct drm_dp_mst_topology_state *state) 5172 { 5173 struct drm_dp_mst_atomic_payload *payload; 5174 struct drm_dp_mst_port *port; 5175 int pbn_used = 0, ret; 5176 bool found = false; 5177 5178 /* Check that we have at least one port in our state that's downstream 5179 * of this branch, otherwise we can skip this branch 5180 */ 5181 list_for_each_entry(payload, &state->payloads, next) { 5182 if (!payload->pbn || 5183 !drm_dp_mst_port_downstream_of_branch(payload->port, mstb)) 5184 continue; 5185 5186 found = true; 5187 break; 5188 } 5189 if (!found) 5190 return 0; 5191 5192 if (mstb->port_parent) 5193 drm_dbg_atomic(mstb->mgr->dev, 5194 "[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n", 5195 mstb->port_parent->parent, mstb->port_parent, mstb); 5196 else 5197 drm_dbg_atomic(mstb->mgr->dev, "[MSTB:%p] Checking bandwidth limits\n", mstb); 5198 5199 list_for_each_entry(port, &mstb->ports, next) { 5200 ret = drm_dp_mst_atomic_check_port_bw_limit(port, state); 5201 if (ret < 0) 5202 return ret; 5203 5204 pbn_used += ret; 5205 } 5206 5207 return pbn_used; 5208 } 5209 5210 static int 5211 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, 5212 struct drm_dp_mst_topology_state *state) 5213 { 5214 struct drm_dp_mst_atomic_payload *payload; 5215 int pbn_used = 0; 5216 5217 if (port->pdt == DP_PEER_DEVICE_NONE) 5218 return 0; 5219 5220 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { 5221 payload = drm_atomic_get_mst_payload_state(state, port); 5222 if (!payload) 5223 return 0; 5224 5225 /* 5226 * This could happen if the sink deasserted its HPD line, but 5227 * the branch device still reports it as attached (PDT != NONE). 5228 */ 5229 if (!port->full_pbn) { 5230 drm_dbg_atomic(port->mgr->dev, 5231 "[MSTB:%p] [MST PORT:%p] no BW available for the port\n", 5232 port->parent, port); 5233 return -EINVAL; 5234 } 5235 5236 pbn_used = payload->pbn; 5237 } else { 5238 pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb, 5239 state); 5240 if (pbn_used <= 0) 5241 return pbn_used; 5242 } 5243 5244 if (pbn_used > port->full_pbn) { 5245 drm_dbg_atomic(port->mgr->dev, 5246 "[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n", 5247 port->parent, port, pbn_used, port->full_pbn); 5248 return -ENOSPC; 5249 } 5250 5251 drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n", 5252 port->parent, port, pbn_used, port->full_pbn); 5253 5254 return pbn_used; 5255 } 5256 5257 static inline int 5258 drm_dp_mst_atomic_check_payload_alloc_limits(struct drm_dp_mst_topology_mgr *mgr, 5259 struct drm_dp_mst_topology_state *mst_state) 5260 { 5261 struct drm_dp_mst_atomic_payload *payload; 5262 int avail_slots = mst_state->total_avail_slots, payload_count = 0; 5263 5264 list_for_each_entry(payload, &mst_state->payloads, next) { 5265 /* Releasing payloads is always OK-even if the port is gone */ 5266 if (payload->delete) { 5267 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] releases all time slots\n", 5268 payload->port); 5269 continue; 5270 } 5271 5272 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] requires %d time slots\n", 5273 payload->port, payload->time_slots); 5274 5275 avail_slots -= payload->time_slots; 5276 if (avail_slots < 0) { 5277 drm_dbg_atomic(mgr->dev, 5278 "[MST PORT:%p] not enough time slots in mst state %p (avail=%d)\n", 5279 payload->port, mst_state, avail_slots + payload->time_slots); 5280 return -ENOSPC; 5281 } 5282 5283 if (++payload_count > mgr->max_payloads) { 5284 drm_dbg_atomic(mgr->dev, 5285 "[MST MGR:%p] state %p has too many payloads (max=%d)\n", 5286 mgr, mst_state, mgr->max_payloads); 5287 return -EINVAL; 5288 } 5289 5290 /* Assign a VCPI */ 5291 if (!payload->vcpi) { 5292 payload->vcpi = ffz(mst_state->payload_mask) + 1; 5293 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] assigned VCPI #%d\n", 5294 payload->port, payload->vcpi); 5295 mst_state->payload_mask |= BIT(payload->vcpi - 1); 5296 } 5297 } 5298 5299 if (!payload_count) 5300 mst_state->pbn_div = 0; 5301 5302 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] mst state %p TU pbn_div=%d avail=%d used=%d\n", 5303 mgr, mst_state, mst_state->pbn_div, avail_slots, 5304 mst_state->total_avail_slots - avail_slots); 5305 5306 return 0; 5307 } 5308 5309 /** 5310 * drm_dp_mst_add_affected_dsc_crtcs 5311 * @state: Pointer to the new struct drm_dp_mst_topology_state 5312 * @mgr: MST topology manager 5313 * 5314 * Whenever there is a change in mst topology 5315 * DSC configuration would have to be recalculated 5316 * therefore we need to trigger modeset on all affected 5317 * CRTCs in that topology 5318 * 5319 * See also: 5320 * drm_dp_mst_atomic_enable_dsc() 5321 */ 5322 int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr) 5323 { 5324 struct drm_dp_mst_topology_state *mst_state; 5325 struct drm_dp_mst_atomic_payload *pos; 5326 struct drm_connector *connector; 5327 struct drm_connector_state *conn_state; 5328 struct drm_crtc *crtc; 5329 struct drm_crtc_state *crtc_state; 5330 5331 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 5332 5333 if (IS_ERR(mst_state)) 5334 return PTR_ERR(mst_state); 5335 5336 list_for_each_entry(pos, &mst_state->payloads, next) { 5337 5338 connector = pos->port->connector; 5339 5340 if (!connector) 5341 return -EINVAL; 5342 5343 conn_state = drm_atomic_get_connector_state(state, connector); 5344 5345 if (IS_ERR(conn_state)) 5346 return PTR_ERR(conn_state); 5347 5348 crtc = conn_state->crtc; 5349 5350 if (!crtc) 5351 continue; 5352 5353 if (!drm_dp_mst_dsc_aux_for_port(pos->port)) 5354 continue; 5355 5356 crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc); 5357 5358 if (IS_ERR(crtc_state)) 5359 return PTR_ERR(crtc_state); 5360 5361 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] Setting mode_changed flag on CRTC %p\n", 5362 mgr, crtc); 5363 5364 crtc_state->mode_changed = true; 5365 } 5366 return 0; 5367 } 5368 EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs); 5369 5370 /** 5371 * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off 5372 * @state: Pointer to the new drm_atomic_state 5373 * @port: Pointer to the affected MST Port 5374 * @pbn: Newly recalculated bw required for link with DSC enabled 5375 * @enable: Boolean flag to enable or disable DSC on the port 5376 * 5377 * This function enables DSC on the given Port 5378 * by recalculating its vcpi from pbn provided 5379 * and sets dsc_enable flag to keep track of which 5380 * ports have DSC enabled 5381 * 5382 */ 5383 int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state, 5384 struct drm_dp_mst_port *port, 5385 int pbn, bool enable) 5386 { 5387 struct drm_dp_mst_topology_state *mst_state; 5388 struct drm_dp_mst_atomic_payload *payload; 5389 int time_slots = 0; 5390 5391 mst_state = drm_atomic_get_mst_topology_state(state, port->mgr); 5392 if (IS_ERR(mst_state)) 5393 return PTR_ERR(mst_state); 5394 5395 payload = drm_atomic_get_mst_payload_state(mst_state, port); 5396 if (!payload) { 5397 drm_dbg_atomic(state->dev, 5398 "[MST PORT:%p] Couldn't find payload in mst state %p\n", 5399 port, mst_state); 5400 return -EINVAL; 5401 } 5402 5403 if (payload->dsc_enabled == enable) { 5404 drm_dbg_atomic(state->dev, 5405 "[MST PORT:%p] DSC flag is already set to %d, returning %d time slots\n", 5406 port, enable, payload->time_slots); 5407 time_slots = payload->time_slots; 5408 } 5409 5410 if (enable) { 5411 time_slots = drm_dp_atomic_find_time_slots(state, port->mgr, port, pbn); 5412 drm_dbg_atomic(state->dev, 5413 "[MST PORT:%p] Enabling DSC flag, reallocating %d time slots on the port\n", 5414 port, time_slots); 5415 if (time_slots < 0) 5416 return -EINVAL; 5417 } 5418 5419 payload->dsc_enabled = enable; 5420 5421 return time_slots; 5422 } 5423 EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc); 5424 5425 /** 5426 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an 5427 * atomic update is valid 5428 * @state: Pointer to the new &struct drm_dp_mst_topology_state 5429 * 5430 * Checks the given topology state for an atomic update to ensure that it's 5431 * valid. This includes checking whether there's enough bandwidth to support 5432 * the new timeslot allocations in the atomic update. 5433 * 5434 * Any atomic drivers supporting DP MST must make sure to call this after 5435 * checking the rest of their state in their 5436 * &drm_mode_config_funcs.atomic_check() callback. 5437 * 5438 * See also: 5439 * drm_dp_atomic_find_time_slots() 5440 * drm_dp_atomic_release_time_slots() 5441 * 5442 * Returns: 5443 * 5444 * 0 if the new state is valid, negative error code otherwise. 5445 */ 5446 int drm_dp_mst_atomic_check(struct drm_atomic_state *state) 5447 { 5448 struct drm_dp_mst_topology_mgr *mgr; 5449 struct drm_dp_mst_topology_state *mst_state; 5450 int i, ret = 0; 5451 5452 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { 5453 if (!mgr->mst_state) 5454 continue; 5455 5456 ret = drm_dp_mst_atomic_check_payload_alloc_limits(mgr, mst_state); 5457 if (ret) 5458 break; 5459 5460 mutex_lock(&mgr->lock); 5461 ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary, 5462 mst_state); 5463 mutex_unlock(&mgr->lock); 5464 if (ret < 0) 5465 break; 5466 else 5467 ret = 0; 5468 } 5469 5470 return ret; 5471 } 5472 EXPORT_SYMBOL(drm_dp_mst_atomic_check); 5473 5474 const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = { 5475 .atomic_duplicate_state = drm_dp_mst_duplicate_state, 5476 .atomic_destroy_state = drm_dp_mst_destroy_state, 5477 }; 5478 EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs); 5479 5480 /** 5481 * drm_atomic_get_mst_topology_state: get MST topology state 5482 * @state: global atomic state 5483 * @mgr: MST topology manager, also the private object in this case 5484 * 5485 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic 5486 * state vtable so that the private object state returned is that of a MST 5487 * topology object. 5488 * 5489 * RETURNS: 5490 * 5491 * The MST topology state or error pointer. 5492 */ 5493 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state, 5494 struct drm_dp_mst_topology_mgr *mgr) 5495 { 5496 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base)); 5497 } 5498 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state); 5499 5500 /** 5501 * drm_atomic_get_old_mst_topology_state: get old MST topology state in atomic state, if any 5502 * @state: global atomic state 5503 * @mgr: MST topology manager, also the private object in this case 5504 * 5505 * This function wraps drm_atomic_get_old_private_obj_state() passing in the MST atomic 5506 * state vtable so that the private object state returned is that of a MST 5507 * topology object. 5508 * 5509 * Returns: 5510 * 5511 * The old MST topology state, or NULL if there's no topology state for this MST mgr 5512 * in the global atomic state 5513 */ 5514 struct drm_dp_mst_topology_state * 5515 drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state, 5516 struct drm_dp_mst_topology_mgr *mgr) 5517 { 5518 struct drm_private_state *old_priv_state = 5519 drm_atomic_get_old_private_obj_state(state, &mgr->base); 5520 5521 return old_priv_state ? to_dp_mst_topology_state(old_priv_state) : NULL; 5522 } 5523 EXPORT_SYMBOL(drm_atomic_get_old_mst_topology_state); 5524 5525 /** 5526 * drm_atomic_get_new_mst_topology_state: get new MST topology state in atomic state, if any 5527 * @state: global atomic state 5528 * @mgr: MST topology manager, also the private object in this case 5529 * 5530 * This function wraps drm_atomic_get_new_private_obj_state() passing in the MST atomic 5531 * state vtable so that the private object state returned is that of a MST 5532 * topology object. 5533 * 5534 * Returns: 5535 * 5536 * The new MST topology state, or NULL if there's no topology state for this MST mgr 5537 * in the global atomic state 5538 */ 5539 struct drm_dp_mst_topology_state * 5540 drm_atomic_get_new_mst_topology_state(struct drm_atomic_state *state, 5541 struct drm_dp_mst_topology_mgr *mgr) 5542 { 5543 struct drm_private_state *new_priv_state = 5544 drm_atomic_get_new_private_obj_state(state, &mgr->base); 5545 5546 return new_priv_state ? to_dp_mst_topology_state(new_priv_state) : NULL; 5547 } 5548 EXPORT_SYMBOL(drm_atomic_get_new_mst_topology_state); 5549 5550 /** 5551 * drm_dp_mst_topology_mgr_init - initialise a topology manager 5552 * @mgr: manager struct to initialise 5553 * @dev: device providing this structure - for i2c addition. 5554 * @aux: DP helper aux channel to talk to this device 5555 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit 5556 * @max_payloads: maximum number of payloads this GPU can source 5557 * @conn_base_id: the connector object ID the MST device is connected to. 5558 * 5559 * Return 0 for success, or negative error code on failure 5560 */ 5561 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, 5562 struct drm_device *dev, struct drm_dp_aux *aux, 5563 int max_dpcd_transaction_bytes, int max_payloads, 5564 int conn_base_id) 5565 { 5566 struct drm_dp_mst_topology_state *mst_state; 5567 5568 rw_init(&mgr->lock, "mst"); 5569 rw_init(&mgr->qlock, "mstq"); 5570 rw_init(&mgr->delayed_destroy_lock, "mstdc"); 5571 rw_init(&mgr->up_req_lock, "mstup"); 5572 rw_init(&mgr->probe_lock, "mstprb"); 5573 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 5574 rw_init(&mgr->topology_ref_history_lock, "msttr"); 5575 stack_depot_init(); 5576 #endif 5577 INIT_LIST_HEAD(&mgr->tx_msg_downq); 5578 INIT_LIST_HEAD(&mgr->destroy_port_list); 5579 INIT_LIST_HEAD(&mgr->destroy_branch_device_list); 5580 INIT_LIST_HEAD(&mgr->up_req_list); 5581 5582 /* 5583 * delayed_destroy_work will be queued on a dedicated WQ, so that any 5584 * requeuing will be also flushed when deiniting the topology manager. 5585 */ 5586 mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0); 5587 if (mgr->delayed_destroy_wq == NULL) 5588 return -ENOMEM; 5589 5590 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work); 5591 INIT_WORK(&mgr->tx_work, drm_dp_tx_work); 5592 INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work); 5593 INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work); 5594 init_waitqueue_head(&mgr->tx_waitq); 5595 mgr->dev = dev; 5596 mgr->aux = aux; 5597 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes; 5598 mgr->max_payloads = max_payloads; 5599 mgr->conn_base_id = conn_base_id; 5600 5601 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL); 5602 if (mst_state == NULL) 5603 return -ENOMEM; 5604 5605 mst_state->total_avail_slots = 63; 5606 mst_state->start_slot = 1; 5607 5608 mst_state->mgr = mgr; 5609 INIT_LIST_HEAD(&mst_state->payloads); 5610 5611 drm_atomic_private_obj_init(dev, &mgr->base, 5612 &mst_state->base, 5613 &drm_dp_mst_topology_state_funcs); 5614 5615 return 0; 5616 } 5617 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init); 5618 5619 /** 5620 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager. 5621 * @mgr: manager to destroy 5622 */ 5623 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr) 5624 { 5625 drm_dp_mst_topology_mgr_set_mst(mgr, false); 5626 flush_work(&mgr->work); 5627 /* The following will also drain any requeued work on the WQ. */ 5628 if (mgr->delayed_destroy_wq) { 5629 destroy_workqueue(mgr->delayed_destroy_wq); 5630 mgr->delayed_destroy_wq = NULL; 5631 } 5632 mgr->dev = NULL; 5633 mgr->aux = NULL; 5634 drm_atomic_private_obj_fini(&mgr->base); 5635 mgr->funcs = NULL; 5636 5637 mutex_destroy(&mgr->delayed_destroy_lock); 5638 mutex_destroy(&mgr->qlock); 5639 mutex_destroy(&mgr->lock); 5640 mutex_destroy(&mgr->up_req_lock); 5641 mutex_destroy(&mgr->probe_lock); 5642 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 5643 mutex_destroy(&mgr->topology_ref_history_lock); 5644 #endif 5645 } 5646 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy); 5647 5648 static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num) 5649 { 5650 int i; 5651 5652 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS) 5653 return false; 5654 5655 for (i = 0; i < num - 1; i++) { 5656 if (msgs[i].flags & I2C_M_RD || 5657 msgs[i].len > 0xff) 5658 return false; 5659 } 5660 5661 return msgs[num - 1].flags & I2C_M_RD && 5662 msgs[num - 1].len <= 0xff; 5663 } 5664 5665 static bool remote_i2c_write_ok(const struct i2c_msg msgs[], int num) 5666 { 5667 int i; 5668 5669 for (i = 0; i < num - 1; i++) { 5670 if (msgs[i].flags & I2C_M_RD || !(msgs[i].flags & I2C_M_STOP) || 5671 msgs[i].len > 0xff) 5672 return false; 5673 } 5674 5675 return !(msgs[num - 1].flags & I2C_M_RD) && msgs[num - 1].len <= 0xff; 5676 } 5677 5678 static int drm_dp_mst_i2c_read(struct drm_dp_mst_branch *mstb, 5679 struct drm_dp_mst_port *port, 5680 struct i2c_msg *msgs, int num) 5681 { 5682 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5683 unsigned int i; 5684 struct drm_dp_sideband_msg_req_body msg; 5685 struct drm_dp_sideband_msg_tx *txmsg = NULL; 5686 int ret; 5687 5688 memset(&msg, 0, sizeof(msg)); 5689 msg.req_type = DP_REMOTE_I2C_READ; 5690 msg.u.i2c_read.num_transactions = num - 1; 5691 msg.u.i2c_read.port_number = port->port_num; 5692 for (i = 0; i < num - 1; i++) { 5693 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr; 5694 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len; 5695 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf; 5696 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP); 5697 } 5698 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr; 5699 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len; 5700 5701 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 5702 if (!txmsg) { 5703 ret = -ENOMEM; 5704 goto out; 5705 } 5706 5707 txmsg->dst = mstb; 5708 drm_dp_encode_sideband_req(&msg, txmsg); 5709 5710 drm_dp_queue_down_tx(mgr, txmsg); 5711 5712 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 5713 if (ret > 0) { 5714 5715 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 5716 ret = -EREMOTEIO; 5717 goto out; 5718 } 5719 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) { 5720 ret = -EIO; 5721 goto out; 5722 } 5723 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len); 5724 ret = num; 5725 } 5726 out: 5727 kfree(txmsg); 5728 return ret; 5729 } 5730 5731 static int drm_dp_mst_i2c_write(struct drm_dp_mst_branch *mstb, 5732 struct drm_dp_mst_port *port, 5733 struct i2c_msg *msgs, int num) 5734 { 5735 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5736 unsigned int i; 5737 struct drm_dp_sideband_msg_req_body msg; 5738 struct drm_dp_sideband_msg_tx *txmsg = NULL; 5739 int ret; 5740 5741 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 5742 if (!txmsg) { 5743 ret = -ENOMEM; 5744 goto out; 5745 } 5746 for (i = 0; i < num; i++) { 5747 memset(&msg, 0, sizeof(msg)); 5748 msg.req_type = DP_REMOTE_I2C_WRITE; 5749 msg.u.i2c_write.port_number = port->port_num; 5750 msg.u.i2c_write.write_i2c_device_id = msgs[i].addr; 5751 msg.u.i2c_write.num_bytes = msgs[i].len; 5752 msg.u.i2c_write.bytes = msgs[i].buf; 5753 5754 memset(txmsg, 0, sizeof(*txmsg)); 5755 txmsg->dst = mstb; 5756 5757 drm_dp_encode_sideband_req(&msg, txmsg); 5758 drm_dp_queue_down_tx(mgr, txmsg); 5759 5760 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 5761 if (ret > 0) { 5762 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 5763 ret = -EREMOTEIO; 5764 goto out; 5765 } 5766 } else { 5767 goto out; 5768 } 5769 } 5770 ret = num; 5771 out: 5772 kfree(txmsg); 5773 return ret; 5774 } 5775 5776 /* I2C device */ 5777 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, 5778 struct i2c_msg *msgs, int num) 5779 { 5780 struct drm_dp_aux *aux = adapter->algo_data; 5781 struct drm_dp_mst_port *port = 5782 container_of(aux, struct drm_dp_mst_port, aux); 5783 struct drm_dp_mst_branch *mstb; 5784 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5785 int ret; 5786 5787 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 5788 if (!mstb) 5789 return -EREMOTEIO; 5790 5791 if (remote_i2c_read_ok(msgs, num)) { 5792 ret = drm_dp_mst_i2c_read(mstb, port, msgs, num); 5793 } else if (remote_i2c_write_ok(msgs, num)) { 5794 ret = drm_dp_mst_i2c_write(mstb, port, msgs, num); 5795 } else { 5796 drm_dbg_kms(mgr->dev, "Unsupported I2C transaction for MST device\n"); 5797 ret = -EIO; 5798 } 5799 5800 drm_dp_mst_topology_put_mstb(mstb); 5801 return ret; 5802 } 5803 5804 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter) 5805 { 5806 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | 5807 I2C_FUNC_SMBUS_READ_BLOCK_DATA | 5808 I2C_FUNC_SMBUS_BLOCK_PROC_CALL | 5809 I2C_FUNC_10BIT_ADDR; 5810 } 5811 5812 static const struct i2c_algorithm drm_dp_mst_i2c_algo = { 5813 .functionality = drm_dp_mst_i2c_functionality, 5814 .master_xfer = drm_dp_mst_i2c_xfer, 5815 }; 5816 5817 /** 5818 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX 5819 * @port: The port to add the I2C bus on 5820 * 5821 * Returns 0 on success or a negative error code on failure. 5822 */ 5823 static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port) 5824 { 5825 struct drm_dp_aux *aux = &port->aux; 5826 #ifdef __linux__ 5827 struct device *parent_dev = port->mgr->dev->dev; 5828 #endif 5829 5830 aux->ddc.algo = &drm_dp_mst_i2c_algo; 5831 aux->ddc.algo_data = aux; 5832 aux->ddc.retries = 3; 5833 5834 #ifdef __linux__ 5835 aux->ddc.class = I2C_CLASS_DDC; 5836 aux->ddc.owner = THIS_MODULE; 5837 /* FIXME: set the kdev of the port's connector as parent */ 5838 aux->ddc.dev.parent = parent_dev; 5839 aux->ddc.dev.of_node = parent_dev->of_node; 5840 #endif 5841 5842 strscpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev), 5843 sizeof(aux->ddc.name)); 5844 5845 return i2c_add_adapter(&aux->ddc); 5846 } 5847 5848 /** 5849 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter 5850 * @port: The port to remove the I2C bus from 5851 */ 5852 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port) 5853 { 5854 i2c_del_adapter(&port->aux.ddc); 5855 } 5856 5857 /** 5858 * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device 5859 * @port: The port to check 5860 * 5861 * A single physical MST hub object can be represented in the topology 5862 * by multiple branches, with virtual ports between those branches. 5863 * 5864 * As of DP1.4, An MST hub with internal (virtual) ports must expose 5865 * certain DPCD registers over those ports. See sections 2.6.1.1.1 5866 * and 2.6.1.1.2 of Display Port specification v1.4 for details. 5867 * 5868 * May acquire mgr->lock 5869 * 5870 * Returns: 5871 * true if the port is a virtual DP peer device, false otherwise 5872 */ 5873 static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port) 5874 { 5875 struct drm_dp_mst_port *downstream_port; 5876 5877 if (!port || port->dpcd_rev < DP_DPCD_REV_14) 5878 return false; 5879 5880 /* Virtual DP Sink (Internal Display Panel) */ 5881 if (port->port_num >= 8) 5882 return true; 5883 5884 /* DP-to-HDMI Protocol Converter */ 5885 if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV && 5886 !port->mcs && 5887 port->ldps) 5888 return true; 5889 5890 /* DP-to-DP */ 5891 mutex_lock(&port->mgr->lock); 5892 if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING && 5893 port->mstb && 5894 port->mstb->num_ports == 2) { 5895 list_for_each_entry(downstream_port, &port->mstb->ports, next) { 5896 if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK && 5897 !downstream_port->input) { 5898 mutex_unlock(&port->mgr->lock); 5899 return true; 5900 } 5901 } 5902 } 5903 mutex_unlock(&port->mgr->lock); 5904 5905 return false; 5906 } 5907 5908 /** 5909 * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC 5910 * @port: The port to check. A leaf of the MST tree with an attached display. 5911 * 5912 * Depending on the situation, DSC may be enabled via the endpoint aux, 5913 * the immediately upstream aux, or the connector's physical aux. 5914 * 5915 * This is both the correct aux to read DSC_CAPABILITY and the 5916 * correct aux to write DSC_ENABLED. 5917 * 5918 * This operation can be expensive (up to four aux reads), so 5919 * the caller should cache the return. 5920 * 5921 * Returns: 5922 * NULL if DSC cannot be enabled on this port, otherwise the aux device 5923 */ 5924 struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port) 5925 { 5926 struct drm_dp_mst_port *immediate_upstream_port; 5927 struct drm_dp_mst_port *fec_port; 5928 struct drm_dp_desc desc = {}; 5929 u8 endpoint_fec; 5930 u8 endpoint_dsc; 5931 5932 if (!port) 5933 return NULL; 5934 5935 if (port->parent->port_parent) 5936 immediate_upstream_port = port->parent->port_parent; 5937 else 5938 immediate_upstream_port = NULL; 5939 5940 fec_port = immediate_upstream_port; 5941 while (fec_port) { 5942 /* 5943 * Each physical link (i.e. not a virtual port) between the 5944 * output and the primary device must support FEC 5945 */ 5946 if (!drm_dp_mst_is_virtual_dpcd(fec_port) && 5947 !fec_port->fec_capable) 5948 return NULL; 5949 5950 fec_port = fec_port->parent->port_parent; 5951 } 5952 5953 /* DP-to-DP peer device */ 5954 if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) { 5955 u8 upstream_dsc; 5956 5957 if (drm_dp_dpcd_read(&port->aux, 5958 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1) 5959 return NULL; 5960 if (drm_dp_dpcd_read(&port->aux, 5961 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1) 5962 return NULL; 5963 if (drm_dp_dpcd_read(&immediate_upstream_port->aux, 5964 DP_DSC_SUPPORT, &upstream_dsc, 1) != 1) 5965 return NULL; 5966 5967 /* Enpoint decompression with DP-to-DP peer device */ 5968 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) && 5969 (endpoint_fec & DP_FEC_CAPABLE) && 5970 (upstream_dsc & DP_DSC_PASSTHROUGH_IS_SUPPORTED)) { 5971 port->passthrough_aux = &immediate_upstream_port->aux; 5972 return &port->aux; 5973 } 5974 5975 /* Virtual DPCD decompression with DP-to-DP peer device */ 5976 return &immediate_upstream_port->aux; 5977 } 5978 5979 /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */ 5980 if (drm_dp_mst_is_virtual_dpcd(port)) 5981 return &port->aux; 5982 5983 /* 5984 * Synaptics quirk 5985 * Applies to ports for which: 5986 * - Physical aux has Synaptics OUI 5987 * - DPv1.4 or higher 5988 * - Port is on primary branch device 5989 * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG) 5990 */ 5991 if (drm_dp_read_desc(port->mgr->aux, &desc, true)) 5992 return NULL; 5993 5994 if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) && 5995 port->mgr->dpcd[DP_DPCD_REV] >= DP_DPCD_REV_14 && 5996 port->parent == port->mgr->mst_primary) { 5997 u8 dpcd_ext[DP_RECEIVER_CAP_SIZE]; 5998 5999 if (drm_dp_read_dpcd_caps(port->mgr->aux, dpcd_ext) < 0) 6000 return NULL; 6001 6002 if ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT) && 6003 ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) 6004 != DP_DWN_STRM_PORT_TYPE_ANALOG)) 6005 return port->mgr->aux; 6006 } 6007 6008 /* 6009 * The check below verifies if the MST sink 6010 * connected to the GPU is capable of DSC - 6011 * therefore the endpoint needs to be 6012 * both DSC and FEC capable. 6013 */ 6014 if (drm_dp_dpcd_read(&port->aux, 6015 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1) 6016 return NULL; 6017 if (drm_dp_dpcd_read(&port->aux, 6018 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1) 6019 return NULL; 6020 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) && 6021 (endpoint_fec & DP_FEC_CAPABLE)) 6022 return &port->aux; 6023 6024 return NULL; 6025 } 6026 EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port); 6027