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_fixed.h> 47 #include <drm/drm_print.h> 48 #include <drm/drm_probe_helper.h> 49 50 #include "drm_dp_helper_internal.h" 51 #include "drm_dp_mst_topology_internal.h" 52 53 /** 54 * DOC: dp mst helper 55 * 56 * These functions contain parts of the DisplayPort 1.2a MultiStream Transport 57 * protocol. The helpers contain a topology manager and bandwidth manager. 58 * The helpers encapsulate the sending and received of sideband msgs. 59 */ 60 struct drm_dp_pending_up_req { 61 struct drm_dp_sideband_msg_hdr hdr; 62 struct drm_dp_sideband_msg_req_body msg; 63 struct list_head next; 64 }; 65 66 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, 67 char *buf); 68 69 static void drm_dp_mst_topology_put_port(struct drm_dp_mst_port *port); 70 71 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, 72 int id, u8 start_slot, u8 num_slots); 73 74 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, 75 struct drm_dp_mst_port *port, 76 int offset, int size, u8 *bytes); 77 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, 78 struct drm_dp_mst_port *port, 79 int offset, int size, u8 *bytes); 80 81 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 82 struct drm_dp_mst_branch *mstb); 83 84 static void 85 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr, 86 struct drm_dp_mst_branch *mstb); 87 88 static int drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, 89 struct drm_dp_mst_branch *mstb, 90 struct drm_dp_mst_port *port); 91 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, 92 guid_t *guid); 93 94 static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port); 95 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port); 96 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr); 97 98 static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port, 99 struct drm_dp_mst_branch *branch); 100 101 #define DBG_PREFIX "[dp_mst]" 102 103 #define DP_STR(x) [DP_ ## x] = #x 104 105 static const char *drm_dp_mst_req_type_str(u8 req_type) 106 { 107 static const char * const req_type_str[] = { 108 DP_STR(GET_MSG_TRANSACTION_VERSION), 109 DP_STR(LINK_ADDRESS), 110 DP_STR(CONNECTION_STATUS_NOTIFY), 111 DP_STR(ENUM_PATH_RESOURCES), 112 DP_STR(ALLOCATE_PAYLOAD), 113 DP_STR(QUERY_PAYLOAD), 114 DP_STR(RESOURCE_STATUS_NOTIFY), 115 DP_STR(CLEAR_PAYLOAD_ID_TABLE), 116 DP_STR(REMOTE_DPCD_READ), 117 DP_STR(REMOTE_DPCD_WRITE), 118 DP_STR(REMOTE_I2C_READ), 119 DP_STR(REMOTE_I2C_WRITE), 120 DP_STR(POWER_UP_PHY), 121 DP_STR(POWER_DOWN_PHY), 122 DP_STR(SINK_EVENT_NOTIFY), 123 DP_STR(QUERY_STREAM_ENC_STATUS), 124 }; 125 126 if (req_type >= ARRAY_SIZE(req_type_str) || 127 !req_type_str[req_type]) 128 return "unknown"; 129 130 return req_type_str[req_type]; 131 } 132 133 #undef DP_STR 134 #define DP_STR(x) [DP_NAK_ ## x] = #x 135 136 static const char *drm_dp_mst_nak_reason_str(u8 nak_reason) 137 { 138 static const char * const nak_reason_str[] = { 139 DP_STR(WRITE_FAILURE), 140 DP_STR(INVALID_READ), 141 DP_STR(CRC_FAILURE), 142 DP_STR(BAD_PARAM), 143 DP_STR(DEFER), 144 DP_STR(LINK_FAILURE), 145 DP_STR(NO_RESOURCES), 146 DP_STR(DPCD_FAIL), 147 DP_STR(I2C_NAK), 148 DP_STR(ALLOCATE_FAIL), 149 }; 150 151 if (nak_reason >= ARRAY_SIZE(nak_reason_str) || 152 !nak_reason_str[nak_reason]) 153 return "unknown"; 154 155 return nak_reason_str[nak_reason]; 156 } 157 158 #undef DP_STR 159 #define DP_STR(x) [DRM_DP_SIDEBAND_TX_ ## x] = #x 160 161 static const char *drm_dp_mst_sideband_tx_state_str(int state) 162 { 163 static const char * const sideband_reason_str[] = { 164 DP_STR(QUEUED), 165 DP_STR(START_SEND), 166 DP_STR(SENT), 167 DP_STR(RX), 168 DP_STR(TIMEOUT), 169 }; 170 171 if (state >= ARRAY_SIZE(sideband_reason_str) || 172 !sideband_reason_str[state]) 173 return "unknown"; 174 175 return sideband_reason_str[state]; 176 } 177 178 static int 179 drm_dp_mst_rad_to_str(const u8 rad[8], u8 lct, char *out, size_t len) 180 { 181 int i; 182 u8 unpacked_rad[16]; 183 184 for (i = 0; i < lct; i++) { 185 if (i % 2) 186 unpacked_rad[i] = rad[i / 2] >> 4; 187 else 188 unpacked_rad[i] = rad[i / 2] & BIT_MASK(4); 189 } 190 191 /* TODO: Eventually add something to printk so we can format the rad 192 * like this: 1.2.3 193 */ 194 return snprintf(out, len, "%*phC", lct, unpacked_rad); 195 } 196 197 /* sideband msg handling */ 198 static u8 drm_dp_msg_header_crc4(const uint8_t *data, size_t num_nibbles) 199 { 200 u8 bitmask = 0x80; 201 u8 bitshift = 7; 202 u8 array_index = 0; 203 int number_of_bits = num_nibbles * 4; 204 u8 remainder = 0; 205 206 while (number_of_bits != 0) { 207 number_of_bits--; 208 remainder <<= 1; 209 remainder |= (data[array_index] & bitmask) >> bitshift; 210 bitmask >>= 1; 211 bitshift--; 212 if (bitmask == 0) { 213 bitmask = 0x80; 214 bitshift = 7; 215 array_index++; 216 } 217 if ((remainder & 0x10) == 0x10) 218 remainder ^= 0x13; 219 } 220 221 number_of_bits = 4; 222 while (number_of_bits != 0) { 223 number_of_bits--; 224 remainder <<= 1; 225 if ((remainder & 0x10) != 0) 226 remainder ^= 0x13; 227 } 228 229 return remainder; 230 } 231 232 static u8 drm_dp_msg_data_crc4(const uint8_t *data, u8 number_of_bytes) 233 { 234 u8 bitmask = 0x80; 235 u8 bitshift = 7; 236 u8 array_index = 0; 237 int number_of_bits = number_of_bytes * 8; 238 u16 remainder = 0; 239 240 while (number_of_bits != 0) { 241 number_of_bits--; 242 remainder <<= 1; 243 remainder |= (data[array_index] & bitmask) >> bitshift; 244 bitmask >>= 1; 245 bitshift--; 246 if (bitmask == 0) { 247 bitmask = 0x80; 248 bitshift = 7; 249 array_index++; 250 } 251 if ((remainder & 0x100) == 0x100) 252 remainder ^= 0xd5; 253 } 254 255 number_of_bits = 8; 256 while (number_of_bits != 0) { 257 number_of_bits--; 258 remainder <<= 1; 259 if ((remainder & 0x100) != 0) 260 remainder ^= 0xd5; 261 } 262 263 return remainder & 0xff; 264 } 265 static inline u8 drm_dp_calc_sb_hdr_size(struct drm_dp_sideband_msg_hdr *hdr) 266 { 267 u8 size = 3; 268 269 size += (hdr->lct / 2); 270 return size; 271 } 272 273 static void drm_dp_encode_sideband_msg_hdr(struct drm_dp_sideband_msg_hdr *hdr, 274 u8 *buf, int *len) 275 { 276 int idx = 0; 277 int i; 278 u8 crc4; 279 280 buf[idx++] = ((hdr->lct & 0xf) << 4) | (hdr->lcr & 0xf); 281 for (i = 0; i < (hdr->lct / 2); i++) 282 buf[idx++] = hdr->rad[i]; 283 buf[idx++] = (hdr->broadcast << 7) | (hdr->path_msg << 6) | 284 (hdr->msg_len & 0x3f); 285 buf[idx++] = (hdr->somt << 7) | (hdr->eomt << 6) | (hdr->seqno << 4); 286 287 crc4 = drm_dp_msg_header_crc4(buf, (idx * 2) - 1); 288 buf[idx - 1] |= (crc4 & 0xf); 289 290 *len = idx; 291 } 292 293 static bool drm_dp_decode_sideband_msg_hdr(const struct drm_dp_mst_topology_mgr *mgr, 294 struct drm_dp_sideband_msg_hdr *hdr, 295 u8 *buf, int buflen, u8 *hdrlen) 296 { 297 u8 crc4; 298 u8 len; 299 int i; 300 u8 idx; 301 302 if (buf[0] == 0) 303 return false; 304 len = 3; 305 len += ((buf[0] & 0xf0) >> 4) / 2; 306 if (len > buflen) 307 return false; 308 crc4 = drm_dp_msg_header_crc4(buf, (len * 2) - 1); 309 310 if ((crc4 & 0xf) != (buf[len - 1] & 0xf)) { 311 drm_dbg_kms(mgr->dev, "crc4 mismatch 0x%x 0x%x\n", crc4, buf[len - 1]); 312 return false; 313 } 314 315 hdr->lct = (buf[0] & 0xf0) >> 4; 316 hdr->lcr = (buf[0] & 0xf); 317 idx = 1; 318 for (i = 0; i < (hdr->lct / 2); i++) 319 hdr->rad[i] = buf[idx++]; 320 hdr->broadcast = (buf[idx] >> 7) & 0x1; 321 hdr->path_msg = (buf[idx] >> 6) & 0x1; 322 hdr->msg_len = buf[idx] & 0x3f; 323 idx++; 324 hdr->somt = (buf[idx] >> 7) & 0x1; 325 hdr->eomt = (buf[idx] >> 6) & 0x1; 326 hdr->seqno = (buf[idx] >> 4) & 0x1; 327 idx++; 328 *hdrlen = idx; 329 return true; 330 } 331 332 void 333 drm_dp_encode_sideband_req(const struct drm_dp_sideband_msg_req_body *req, 334 struct drm_dp_sideband_msg_tx *raw) 335 { 336 int idx = 0; 337 int i; 338 u8 *buf = raw->msg; 339 340 buf[idx++] = req->req_type & 0x7f; 341 342 switch (req->req_type) { 343 case DP_ENUM_PATH_RESOURCES: 344 case DP_POWER_DOWN_PHY: 345 case DP_POWER_UP_PHY: 346 buf[idx] = (req->u.port_num.port_number & 0xf) << 4; 347 idx++; 348 break; 349 case DP_ALLOCATE_PAYLOAD: 350 buf[idx] = (req->u.allocate_payload.port_number & 0xf) << 4 | 351 (req->u.allocate_payload.number_sdp_streams & 0xf); 352 idx++; 353 buf[idx] = (req->u.allocate_payload.vcpi & 0x7f); 354 idx++; 355 buf[idx] = (req->u.allocate_payload.pbn >> 8); 356 idx++; 357 buf[idx] = (req->u.allocate_payload.pbn & 0xff); 358 idx++; 359 for (i = 0; i < req->u.allocate_payload.number_sdp_streams / 2; i++) { 360 buf[idx] = ((req->u.allocate_payload.sdp_stream_sink[i * 2] & 0xf) << 4) | 361 (req->u.allocate_payload.sdp_stream_sink[i * 2 + 1] & 0xf); 362 idx++; 363 } 364 if (req->u.allocate_payload.number_sdp_streams & 1) { 365 i = req->u.allocate_payload.number_sdp_streams - 1; 366 buf[idx] = (req->u.allocate_payload.sdp_stream_sink[i] & 0xf) << 4; 367 idx++; 368 } 369 break; 370 case DP_QUERY_PAYLOAD: 371 buf[idx] = (req->u.query_payload.port_number & 0xf) << 4; 372 idx++; 373 buf[idx] = (req->u.query_payload.vcpi & 0x7f); 374 idx++; 375 break; 376 case DP_REMOTE_DPCD_READ: 377 buf[idx] = (req->u.dpcd_read.port_number & 0xf) << 4; 378 buf[idx] |= ((req->u.dpcd_read.dpcd_address & 0xf0000) >> 16) & 0xf; 379 idx++; 380 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff00) >> 8; 381 idx++; 382 buf[idx] = (req->u.dpcd_read.dpcd_address & 0xff); 383 idx++; 384 buf[idx] = (req->u.dpcd_read.num_bytes); 385 idx++; 386 break; 387 388 case DP_REMOTE_DPCD_WRITE: 389 buf[idx] = (req->u.dpcd_write.port_number & 0xf) << 4; 390 buf[idx] |= ((req->u.dpcd_write.dpcd_address & 0xf0000) >> 16) & 0xf; 391 idx++; 392 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff00) >> 8; 393 idx++; 394 buf[idx] = (req->u.dpcd_write.dpcd_address & 0xff); 395 idx++; 396 buf[idx] = (req->u.dpcd_write.num_bytes); 397 idx++; 398 memcpy(&buf[idx], req->u.dpcd_write.bytes, req->u.dpcd_write.num_bytes); 399 idx += req->u.dpcd_write.num_bytes; 400 break; 401 case DP_REMOTE_I2C_READ: 402 buf[idx] = (req->u.i2c_read.port_number & 0xf) << 4; 403 buf[idx] |= (req->u.i2c_read.num_transactions & 0x3); 404 idx++; 405 for (i = 0; i < (req->u.i2c_read.num_transactions & 0x3); i++) { 406 buf[idx] = req->u.i2c_read.transactions[i].i2c_dev_id & 0x7f; 407 idx++; 408 buf[idx] = req->u.i2c_read.transactions[i].num_bytes; 409 idx++; 410 memcpy(&buf[idx], req->u.i2c_read.transactions[i].bytes, req->u.i2c_read.transactions[i].num_bytes); 411 idx += req->u.i2c_read.transactions[i].num_bytes; 412 413 buf[idx] = (req->u.i2c_read.transactions[i].no_stop_bit & 0x1) << 4; 414 buf[idx] |= (req->u.i2c_read.transactions[i].i2c_transaction_delay & 0xf); 415 idx++; 416 } 417 buf[idx] = (req->u.i2c_read.read_i2c_device_id) & 0x7f; 418 idx++; 419 buf[idx] = (req->u.i2c_read.num_bytes_read); 420 idx++; 421 break; 422 423 case DP_REMOTE_I2C_WRITE: 424 buf[idx] = (req->u.i2c_write.port_number & 0xf) << 4; 425 idx++; 426 buf[idx] = (req->u.i2c_write.write_i2c_device_id) & 0x7f; 427 idx++; 428 buf[idx] = (req->u.i2c_write.num_bytes); 429 idx++; 430 memcpy(&buf[idx], req->u.i2c_write.bytes, req->u.i2c_write.num_bytes); 431 idx += req->u.i2c_write.num_bytes; 432 break; 433 case DP_QUERY_STREAM_ENC_STATUS: { 434 const struct drm_dp_query_stream_enc_status *msg; 435 436 msg = &req->u.enc_status; 437 buf[idx] = msg->stream_id; 438 idx++; 439 memcpy(&buf[idx], msg->client_id, sizeof(msg->client_id)); 440 idx += sizeof(msg->client_id); 441 buf[idx] = 0; 442 buf[idx] |= FIELD_PREP(GENMASK(1, 0), msg->stream_event); 443 buf[idx] |= msg->valid_stream_event ? BIT(2) : 0; 444 buf[idx] |= FIELD_PREP(GENMASK(4, 3), msg->stream_behavior); 445 buf[idx] |= msg->valid_stream_behavior ? BIT(5) : 0; 446 idx++; 447 } 448 break; 449 } 450 raw->cur_len = idx; 451 } 452 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_encode_sideband_req); 453 454 /* Decode a sideband request we've encoded, mainly used for debugging */ 455 int 456 drm_dp_decode_sideband_req(const struct drm_dp_sideband_msg_tx *raw, 457 struct drm_dp_sideband_msg_req_body *req) 458 { 459 const u8 *buf = raw->msg; 460 int i, idx = 0; 461 462 req->req_type = buf[idx++] & 0x7f; 463 switch (req->req_type) { 464 case DP_ENUM_PATH_RESOURCES: 465 case DP_POWER_DOWN_PHY: 466 case DP_POWER_UP_PHY: 467 req->u.port_num.port_number = (buf[idx] >> 4) & 0xf; 468 break; 469 case DP_ALLOCATE_PAYLOAD: 470 { 471 struct drm_dp_allocate_payload *a = 472 &req->u.allocate_payload; 473 474 a->number_sdp_streams = buf[idx] & 0xf; 475 a->port_number = (buf[idx] >> 4) & 0xf; 476 477 WARN_ON(buf[++idx] & 0x80); 478 a->vcpi = buf[idx] & 0x7f; 479 480 a->pbn = buf[++idx] << 8; 481 a->pbn |= buf[++idx]; 482 483 idx++; 484 for (i = 0; i < a->number_sdp_streams; i++) { 485 a->sdp_stream_sink[i] = 486 (buf[idx + (i / 2)] >> ((i % 2) ? 0 : 4)) & 0xf; 487 } 488 } 489 break; 490 case DP_QUERY_PAYLOAD: 491 req->u.query_payload.port_number = (buf[idx] >> 4) & 0xf; 492 WARN_ON(buf[++idx] & 0x80); 493 req->u.query_payload.vcpi = buf[idx] & 0x7f; 494 break; 495 case DP_REMOTE_DPCD_READ: 496 { 497 struct drm_dp_remote_dpcd_read *r = &req->u.dpcd_read; 498 499 r->port_number = (buf[idx] >> 4) & 0xf; 500 501 r->dpcd_address = (buf[idx] << 16) & 0xf0000; 502 r->dpcd_address |= (buf[++idx] << 8) & 0xff00; 503 r->dpcd_address |= buf[++idx] & 0xff; 504 505 r->num_bytes = buf[++idx]; 506 } 507 break; 508 case DP_REMOTE_DPCD_WRITE: 509 { 510 struct drm_dp_remote_dpcd_write *w = 511 &req->u.dpcd_write; 512 513 w->port_number = (buf[idx] >> 4) & 0xf; 514 515 w->dpcd_address = (buf[idx] << 16) & 0xf0000; 516 w->dpcd_address |= (buf[++idx] << 8) & 0xff00; 517 w->dpcd_address |= buf[++idx] & 0xff; 518 519 w->num_bytes = buf[++idx]; 520 521 w->bytes = kmemdup(&buf[++idx], w->num_bytes, 522 GFP_KERNEL); 523 if (!w->bytes) 524 return -ENOMEM; 525 } 526 break; 527 case DP_REMOTE_I2C_READ: 528 { 529 struct drm_dp_remote_i2c_read *r = &req->u.i2c_read; 530 struct drm_dp_remote_i2c_read_tx *tx; 531 bool failed = false; 532 533 r->num_transactions = buf[idx] & 0x3; 534 r->port_number = (buf[idx] >> 4) & 0xf; 535 for (i = 0; i < r->num_transactions; i++) { 536 tx = &r->transactions[i]; 537 538 tx->i2c_dev_id = buf[++idx] & 0x7f; 539 tx->num_bytes = buf[++idx]; 540 tx->bytes = kmemdup(&buf[++idx], 541 tx->num_bytes, 542 GFP_KERNEL); 543 if (!tx->bytes) { 544 failed = true; 545 break; 546 } 547 idx += tx->num_bytes; 548 tx->no_stop_bit = (buf[idx] >> 5) & 0x1; 549 tx->i2c_transaction_delay = buf[idx] & 0xf; 550 } 551 552 if (failed) { 553 for (i = 0; i < r->num_transactions; i++) { 554 tx = &r->transactions[i]; 555 kfree(tx->bytes); 556 } 557 return -ENOMEM; 558 } 559 560 r->read_i2c_device_id = buf[++idx] & 0x7f; 561 r->num_bytes_read = buf[++idx]; 562 } 563 break; 564 case DP_REMOTE_I2C_WRITE: 565 { 566 struct drm_dp_remote_i2c_write *w = &req->u.i2c_write; 567 568 w->port_number = (buf[idx] >> 4) & 0xf; 569 w->write_i2c_device_id = buf[++idx] & 0x7f; 570 w->num_bytes = buf[++idx]; 571 w->bytes = kmemdup(&buf[++idx], w->num_bytes, 572 GFP_KERNEL); 573 if (!w->bytes) 574 return -ENOMEM; 575 } 576 break; 577 case DP_QUERY_STREAM_ENC_STATUS: 578 req->u.enc_status.stream_id = buf[idx++]; 579 for (i = 0; i < sizeof(req->u.enc_status.client_id); i++) 580 req->u.enc_status.client_id[i] = buf[idx++]; 581 582 req->u.enc_status.stream_event = FIELD_GET(GENMASK(1, 0), 583 buf[idx]); 584 req->u.enc_status.valid_stream_event = FIELD_GET(BIT(2), 585 buf[idx]); 586 req->u.enc_status.stream_behavior = FIELD_GET(GENMASK(4, 3), 587 buf[idx]); 588 req->u.enc_status.valid_stream_behavior = FIELD_GET(BIT(5), 589 buf[idx]); 590 break; 591 } 592 593 return 0; 594 } 595 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_decode_sideband_req); 596 597 void 598 drm_dp_dump_sideband_msg_req_body(const struct drm_dp_sideband_msg_req_body *req, 599 int indent, struct drm_printer *printer) 600 { 601 int i; 602 603 #define P(f, ...) drm_printf_indent(printer, indent, f, ##__VA_ARGS__) 604 if (req->req_type == DP_LINK_ADDRESS) { 605 /* No contents to print */ 606 P("type=%s\n", drm_dp_mst_req_type_str(req->req_type)); 607 return; 608 } 609 610 P("type=%s contents:\n", drm_dp_mst_req_type_str(req->req_type)); 611 indent++; 612 613 switch (req->req_type) { 614 case DP_ENUM_PATH_RESOURCES: 615 case DP_POWER_DOWN_PHY: 616 case DP_POWER_UP_PHY: 617 P("port=%d\n", req->u.port_num.port_number); 618 break; 619 case DP_ALLOCATE_PAYLOAD: 620 P("port=%d vcpi=%d pbn=%d sdp_streams=%d %*ph\n", 621 req->u.allocate_payload.port_number, 622 req->u.allocate_payload.vcpi, req->u.allocate_payload.pbn, 623 req->u.allocate_payload.number_sdp_streams, 624 req->u.allocate_payload.number_sdp_streams, 625 req->u.allocate_payload.sdp_stream_sink); 626 break; 627 case DP_QUERY_PAYLOAD: 628 P("port=%d vcpi=%d\n", 629 req->u.query_payload.port_number, 630 req->u.query_payload.vcpi); 631 break; 632 case DP_REMOTE_DPCD_READ: 633 P("port=%d dpcd_addr=%05x len=%d\n", 634 req->u.dpcd_read.port_number, req->u.dpcd_read.dpcd_address, 635 req->u.dpcd_read.num_bytes); 636 break; 637 case DP_REMOTE_DPCD_WRITE: 638 P("port=%d addr=%05x len=%d: %*ph\n", 639 req->u.dpcd_write.port_number, 640 req->u.dpcd_write.dpcd_address, 641 req->u.dpcd_write.num_bytes, req->u.dpcd_write.num_bytes, 642 req->u.dpcd_write.bytes); 643 break; 644 case DP_REMOTE_I2C_READ: 645 P("port=%d num_tx=%d id=%d size=%d:\n", 646 req->u.i2c_read.port_number, 647 req->u.i2c_read.num_transactions, 648 req->u.i2c_read.read_i2c_device_id, 649 req->u.i2c_read.num_bytes_read); 650 651 indent++; 652 for (i = 0; i < req->u.i2c_read.num_transactions; i++) { 653 const struct drm_dp_remote_i2c_read_tx *rtx = 654 &req->u.i2c_read.transactions[i]; 655 656 P("%d: id=%03d size=%03d no_stop_bit=%d tx_delay=%03d: %*ph\n", 657 i, rtx->i2c_dev_id, rtx->num_bytes, 658 rtx->no_stop_bit, rtx->i2c_transaction_delay, 659 rtx->num_bytes, rtx->bytes); 660 } 661 break; 662 case DP_REMOTE_I2C_WRITE: 663 P("port=%d id=%d size=%d: %*ph\n", 664 req->u.i2c_write.port_number, 665 req->u.i2c_write.write_i2c_device_id, 666 req->u.i2c_write.num_bytes, req->u.i2c_write.num_bytes, 667 req->u.i2c_write.bytes); 668 break; 669 case DP_QUERY_STREAM_ENC_STATUS: 670 P("stream_id=%u client_id=%*ph stream_event=%x " 671 "valid_event=%d stream_behavior=%x valid_behavior=%d", 672 req->u.enc_status.stream_id, 673 (int)ARRAY_SIZE(req->u.enc_status.client_id), 674 req->u.enc_status.client_id, req->u.enc_status.stream_event, 675 req->u.enc_status.valid_stream_event, 676 req->u.enc_status.stream_behavior, 677 req->u.enc_status.valid_stream_behavior); 678 break; 679 default: 680 P("???\n"); 681 break; 682 } 683 #undef P 684 } 685 EXPORT_SYMBOL_FOR_TESTS_ONLY(drm_dp_dump_sideband_msg_req_body); 686 687 static inline void 688 drm_dp_mst_dump_sideband_msg_tx(struct drm_printer *p, 689 const struct drm_dp_sideband_msg_tx *txmsg) 690 { 691 struct drm_dp_sideband_msg_req_body req; 692 char buf[64]; 693 int ret; 694 int i; 695 696 drm_dp_mst_rad_to_str(txmsg->dst->rad, txmsg->dst->lct, buf, 697 sizeof(buf)); 698 drm_printf(p, "txmsg cur_offset=%x cur_len=%x seqno=%x state=%s path_msg=%d dst=%s\n", 699 txmsg->cur_offset, txmsg->cur_len, txmsg->seqno, 700 drm_dp_mst_sideband_tx_state_str(txmsg->state), 701 txmsg->path_msg, buf); 702 703 ret = drm_dp_decode_sideband_req(txmsg, &req); 704 if (ret) { 705 drm_printf(p, "<failed to decode sideband req: %d>\n", ret); 706 return; 707 } 708 drm_dp_dump_sideband_msg_req_body(&req, 1, p); 709 710 switch (req.req_type) { 711 case DP_REMOTE_DPCD_WRITE: 712 kfree(req.u.dpcd_write.bytes); 713 break; 714 case DP_REMOTE_I2C_READ: 715 for (i = 0; i < req.u.i2c_read.num_transactions; i++) 716 kfree(req.u.i2c_read.transactions[i].bytes); 717 break; 718 case DP_REMOTE_I2C_WRITE: 719 kfree(req.u.i2c_write.bytes); 720 break; 721 } 722 } 723 724 static void drm_dp_crc_sideband_chunk_req(u8 *msg, u8 len) 725 { 726 u8 crc4; 727 728 crc4 = drm_dp_msg_data_crc4(msg, len); 729 msg[len] = crc4; 730 } 731 732 static void drm_dp_encode_sideband_reply(struct drm_dp_sideband_msg_reply_body *rep, 733 struct drm_dp_sideband_msg_tx *raw) 734 { 735 int idx = 0; 736 u8 *buf = raw->msg; 737 738 buf[idx++] = (rep->reply_type & 0x1) << 7 | (rep->req_type & 0x7f); 739 740 raw->cur_len = idx; 741 } 742 743 static int drm_dp_sideband_msg_set_header(struct drm_dp_sideband_msg_rx *msg, 744 struct drm_dp_sideband_msg_hdr *hdr, 745 u8 hdrlen) 746 { 747 /* 748 * ignore out-of-order messages or messages that are part of a 749 * failed transaction 750 */ 751 if (!hdr->somt && !msg->have_somt) 752 return false; 753 754 /* get length contained in this portion */ 755 msg->curchunk_idx = 0; 756 msg->curchunk_len = hdr->msg_len; 757 msg->curchunk_hdrlen = hdrlen; 758 759 /* we have already gotten an somt - don't bother parsing */ 760 if (hdr->somt && msg->have_somt) 761 return false; 762 763 if (hdr->somt) { 764 memcpy(&msg->initial_hdr, hdr, 765 sizeof(struct drm_dp_sideband_msg_hdr)); 766 msg->have_somt = true; 767 } 768 if (hdr->eomt) 769 msg->have_eomt = true; 770 771 return true; 772 } 773 774 /* this adds a chunk of msg to the builder to get the final msg */ 775 static bool drm_dp_sideband_append_payload(struct drm_dp_sideband_msg_rx *msg, 776 u8 *replybuf, u8 replybuflen) 777 { 778 u8 crc4; 779 780 memcpy(&msg->chunk[msg->curchunk_idx], replybuf, replybuflen); 781 msg->curchunk_idx += replybuflen; 782 783 if (msg->curchunk_idx >= msg->curchunk_len) { 784 /* do CRC */ 785 crc4 = drm_dp_msg_data_crc4(msg->chunk, msg->curchunk_len - 1); 786 if (crc4 != msg->chunk[msg->curchunk_len - 1]) 787 print_hex_dump(KERN_DEBUG, "wrong crc", 788 DUMP_PREFIX_NONE, 16, 1, 789 msg->chunk, msg->curchunk_len, false); 790 /* copy chunk into bigger msg */ 791 memcpy(&msg->msg[msg->curlen], msg->chunk, msg->curchunk_len - 1); 792 msg->curlen += msg->curchunk_len - 1; 793 } 794 return true; 795 } 796 797 static bool drm_dp_sideband_parse_link_address(const struct drm_dp_mst_topology_mgr *mgr, 798 struct drm_dp_sideband_msg_rx *raw, 799 struct drm_dp_sideband_msg_reply_body *repmsg) 800 { 801 int idx = 1; 802 int i; 803 804 import_guid(&repmsg->u.link_addr.guid, &raw->msg[idx]); 805 idx += 16; 806 repmsg->u.link_addr.nports = raw->msg[idx] & 0xf; 807 idx++; 808 if (idx > raw->curlen) 809 goto fail_len; 810 for (i = 0; i < repmsg->u.link_addr.nports; i++) { 811 if (raw->msg[idx] & 0x80) 812 repmsg->u.link_addr.ports[i].input_port = 1; 813 814 repmsg->u.link_addr.ports[i].peer_device_type = (raw->msg[idx] >> 4) & 0x7; 815 repmsg->u.link_addr.ports[i].port_number = (raw->msg[idx] & 0xf); 816 817 idx++; 818 if (idx > raw->curlen) 819 goto fail_len; 820 repmsg->u.link_addr.ports[i].mcs = (raw->msg[idx] >> 7) & 0x1; 821 repmsg->u.link_addr.ports[i].ddps = (raw->msg[idx] >> 6) & 0x1; 822 if (repmsg->u.link_addr.ports[i].input_port == 0) 823 repmsg->u.link_addr.ports[i].legacy_device_plug_status = (raw->msg[idx] >> 5) & 0x1; 824 idx++; 825 if (idx > raw->curlen) 826 goto fail_len; 827 if (repmsg->u.link_addr.ports[i].input_port == 0) { 828 repmsg->u.link_addr.ports[i].dpcd_revision = (raw->msg[idx]); 829 idx++; 830 if (idx > raw->curlen) 831 goto fail_len; 832 import_guid(&repmsg->u.link_addr.ports[i].peer_guid, &raw->msg[idx]); 833 idx += 16; 834 if (idx > raw->curlen) 835 goto fail_len; 836 repmsg->u.link_addr.ports[i].num_sdp_streams = (raw->msg[idx] >> 4) & 0xf; 837 repmsg->u.link_addr.ports[i].num_sdp_stream_sinks = (raw->msg[idx] & 0xf); 838 idx++; 839 840 } 841 if (idx > raw->curlen) 842 goto fail_len; 843 } 844 845 return true; 846 fail_len: 847 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); 848 return false; 849 } 850 851 static bool drm_dp_sideband_parse_remote_dpcd_read(struct drm_dp_sideband_msg_rx *raw, 852 struct drm_dp_sideband_msg_reply_body *repmsg) 853 { 854 int idx = 1; 855 856 repmsg->u.remote_dpcd_read_ack.port_number = raw->msg[idx] & 0xf; 857 idx++; 858 if (idx > raw->curlen) 859 goto fail_len; 860 repmsg->u.remote_dpcd_read_ack.num_bytes = raw->msg[idx]; 861 idx++; 862 if (idx > raw->curlen) 863 goto fail_len; 864 865 memcpy(repmsg->u.remote_dpcd_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_dpcd_read_ack.num_bytes); 866 return true; 867 fail_len: 868 DRM_DEBUG_KMS("link address reply parse length fail %d %d\n", idx, raw->curlen); 869 return false; 870 } 871 872 static bool drm_dp_sideband_parse_remote_dpcd_write(struct drm_dp_sideband_msg_rx *raw, 873 struct drm_dp_sideband_msg_reply_body *repmsg) 874 { 875 int idx = 1; 876 877 repmsg->u.remote_dpcd_write_ack.port_number = raw->msg[idx] & 0xf; 878 idx++; 879 if (idx > raw->curlen) 880 goto fail_len; 881 return true; 882 fail_len: 883 DRM_DEBUG_KMS("parse length fail %d %d\n", idx, raw->curlen); 884 return false; 885 } 886 887 static bool drm_dp_sideband_parse_remote_i2c_read_ack(struct drm_dp_sideband_msg_rx *raw, 888 struct drm_dp_sideband_msg_reply_body *repmsg) 889 { 890 int idx = 1; 891 892 repmsg->u.remote_i2c_read_ack.port_number = (raw->msg[idx] & 0xf); 893 idx++; 894 if (idx > raw->curlen) 895 goto fail_len; 896 repmsg->u.remote_i2c_read_ack.num_bytes = raw->msg[idx]; 897 idx++; 898 /* TODO check */ 899 memcpy(repmsg->u.remote_i2c_read_ack.bytes, &raw->msg[idx], repmsg->u.remote_i2c_read_ack.num_bytes); 900 return true; 901 fail_len: 902 DRM_DEBUG_KMS("remote i2c reply parse length fail %d %d\n", idx, raw->curlen); 903 return false; 904 } 905 906 static bool drm_dp_sideband_parse_enum_path_resources_ack(struct drm_dp_sideband_msg_rx *raw, 907 struct drm_dp_sideband_msg_reply_body *repmsg) 908 { 909 int idx = 1; 910 911 repmsg->u.path_resources.port_number = (raw->msg[idx] >> 4) & 0xf; 912 repmsg->u.path_resources.fec_capable = raw->msg[idx] & 0x1; 913 idx++; 914 if (idx > raw->curlen) 915 goto fail_len; 916 repmsg->u.path_resources.full_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 917 idx += 2; 918 if (idx > raw->curlen) 919 goto fail_len; 920 repmsg->u.path_resources.avail_payload_bw_number = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 921 idx += 2; 922 if (idx > raw->curlen) 923 goto fail_len; 924 return true; 925 fail_len: 926 DRM_DEBUG_KMS("enum resource parse length fail %d %d\n", idx, raw->curlen); 927 return false; 928 } 929 930 static bool drm_dp_sideband_parse_allocate_payload_ack(struct drm_dp_sideband_msg_rx *raw, 931 struct drm_dp_sideband_msg_reply_body *repmsg) 932 { 933 int idx = 1; 934 935 repmsg->u.allocate_payload.port_number = (raw->msg[idx] >> 4) & 0xf; 936 idx++; 937 if (idx > raw->curlen) 938 goto fail_len; 939 repmsg->u.allocate_payload.vcpi = raw->msg[idx]; 940 idx++; 941 if (idx > raw->curlen) 942 goto fail_len; 943 repmsg->u.allocate_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx+1]); 944 idx += 2; 945 if (idx > raw->curlen) 946 goto fail_len; 947 return true; 948 fail_len: 949 DRM_DEBUG_KMS("allocate payload parse length fail %d %d\n", idx, raw->curlen); 950 return false; 951 } 952 953 static bool drm_dp_sideband_parse_query_payload_ack(struct drm_dp_sideband_msg_rx *raw, 954 struct drm_dp_sideband_msg_reply_body *repmsg) 955 { 956 int idx = 1; 957 958 repmsg->u.query_payload.port_number = (raw->msg[idx] >> 4) & 0xf; 959 idx++; 960 if (idx > raw->curlen) 961 goto fail_len; 962 repmsg->u.query_payload.allocated_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); 963 idx += 2; 964 if (idx > raw->curlen) 965 goto fail_len; 966 return true; 967 fail_len: 968 DRM_DEBUG_KMS("query payload parse length fail %d %d\n", idx, raw->curlen); 969 return false; 970 } 971 972 static bool drm_dp_sideband_parse_power_updown_phy_ack(struct drm_dp_sideband_msg_rx *raw, 973 struct drm_dp_sideband_msg_reply_body *repmsg) 974 { 975 int idx = 1; 976 977 repmsg->u.port_number.port_number = (raw->msg[idx] >> 4) & 0xf; 978 idx++; 979 if (idx > raw->curlen) { 980 DRM_DEBUG_KMS("power up/down phy parse length fail %d %d\n", 981 idx, raw->curlen); 982 return false; 983 } 984 return true; 985 } 986 987 static bool 988 drm_dp_sideband_parse_query_stream_enc_status( 989 struct drm_dp_sideband_msg_rx *raw, 990 struct drm_dp_sideband_msg_reply_body *repmsg) 991 { 992 struct drm_dp_query_stream_enc_status_ack_reply *reply; 993 994 reply = &repmsg->u.enc_status; 995 996 reply->stream_id = raw->msg[3]; 997 998 reply->reply_signed = raw->msg[2] & BIT(0); 999 1000 /* 1001 * NOTE: It's my impression from reading the spec that the below parsing 1002 * is correct. However I noticed while testing with an HDCP 1.4 display 1003 * through an HDCP 2.2 hub that only bit 3 was set. In that case, I 1004 * would expect both bits to be set. So keep the parsing following the 1005 * spec, but beware reality might not match the spec (at least for some 1006 * configurations). 1007 */ 1008 reply->hdcp_1x_device_present = raw->msg[2] & BIT(4); 1009 reply->hdcp_2x_device_present = raw->msg[2] & BIT(3); 1010 1011 reply->query_capable_device_present = raw->msg[2] & BIT(5); 1012 reply->legacy_device_present = raw->msg[2] & BIT(6); 1013 reply->unauthorizable_device_present = raw->msg[2] & BIT(7); 1014 1015 reply->auth_completed = !!(raw->msg[1] & BIT(3)); 1016 reply->encryption_enabled = !!(raw->msg[1] & BIT(4)); 1017 reply->repeater_present = !!(raw->msg[1] & BIT(5)); 1018 reply->state = (raw->msg[1] & GENMASK(7, 6)) >> 6; 1019 1020 return true; 1021 } 1022 1023 static bool drm_dp_sideband_parse_reply(const struct drm_dp_mst_topology_mgr *mgr, 1024 struct drm_dp_sideband_msg_rx *raw, 1025 struct drm_dp_sideband_msg_reply_body *msg) 1026 { 1027 memset(msg, 0, sizeof(*msg)); 1028 msg->reply_type = (raw->msg[0] & 0x80) >> 7; 1029 msg->req_type = (raw->msg[0] & 0x7f); 1030 1031 if (msg->reply_type == DP_SIDEBAND_REPLY_NAK) { 1032 import_guid(&msg->u.nak.guid, &raw->msg[1]); 1033 msg->u.nak.reason = raw->msg[17]; 1034 msg->u.nak.nak_data = raw->msg[18]; 1035 return false; 1036 } 1037 1038 switch (msg->req_type) { 1039 case DP_LINK_ADDRESS: 1040 return drm_dp_sideband_parse_link_address(mgr, raw, msg); 1041 case DP_QUERY_PAYLOAD: 1042 return drm_dp_sideband_parse_query_payload_ack(raw, msg); 1043 case DP_REMOTE_DPCD_READ: 1044 return drm_dp_sideband_parse_remote_dpcd_read(raw, msg); 1045 case DP_REMOTE_DPCD_WRITE: 1046 return drm_dp_sideband_parse_remote_dpcd_write(raw, msg); 1047 case DP_REMOTE_I2C_READ: 1048 return drm_dp_sideband_parse_remote_i2c_read_ack(raw, msg); 1049 case DP_REMOTE_I2C_WRITE: 1050 return true; /* since there's nothing to parse */ 1051 case DP_ENUM_PATH_RESOURCES: 1052 return drm_dp_sideband_parse_enum_path_resources_ack(raw, msg); 1053 case DP_ALLOCATE_PAYLOAD: 1054 return drm_dp_sideband_parse_allocate_payload_ack(raw, msg); 1055 case DP_POWER_DOWN_PHY: 1056 case DP_POWER_UP_PHY: 1057 return drm_dp_sideband_parse_power_updown_phy_ack(raw, msg); 1058 case DP_CLEAR_PAYLOAD_ID_TABLE: 1059 return true; /* since there's nothing to parse */ 1060 case DP_QUERY_STREAM_ENC_STATUS: 1061 return drm_dp_sideband_parse_query_stream_enc_status(raw, msg); 1062 default: 1063 drm_err(mgr->dev, "Got unknown reply 0x%02x (%s)\n", 1064 msg->req_type, drm_dp_mst_req_type_str(msg->req_type)); 1065 return false; 1066 } 1067 } 1068 1069 static bool 1070 drm_dp_sideband_parse_connection_status_notify(const struct drm_dp_mst_topology_mgr *mgr, 1071 struct drm_dp_sideband_msg_rx *raw, 1072 struct drm_dp_sideband_msg_req_body *msg) 1073 { 1074 int idx = 1; 1075 1076 msg->u.conn_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; 1077 idx++; 1078 if (idx > raw->curlen) 1079 goto fail_len; 1080 1081 import_guid(&msg->u.conn_stat.guid, &raw->msg[idx]); 1082 idx += 16; 1083 if (idx > raw->curlen) 1084 goto fail_len; 1085 1086 msg->u.conn_stat.legacy_device_plug_status = (raw->msg[idx] >> 6) & 0x1; 1087 msg->u.conn_stat.displayport_device_plug_status = (raw->msg[idx] >> 5) & 0x1; 1088 msg->u.conn_stat.message_capability_status = (raw->msg[idx] >> 4) & 0x1; 1089 msg->u.conn_stat.input_port = (raw->msg[idx] >> 3) & 0x1; 1090 msg->u.conn_stat.peer_device_type = (raw->msg[idx] & 0x7); 1091 idx++; 1092 return true; 1093 fail_len: 1094 drm_dbg_kms(mgr->dev, "connection status reply parse length fail %d %d\n", 1095 idx, raw->curlen); 1096 return false; 1097 } 1098 1099 static bool drm_dp_sideband_parse_resource_status_notify(const struct drm_dp_mst_topology_mgr *mgr, 1100 struct drm_dp_sideband_msg_rx *raw, 1101 struct drm_dp_sideband_msg_req_body *msg) 1102 { 1103 int idx = 1; 1104 1105 msg->u.resource_stat.port_number = (raw->msg[idx] & 0xf0) >> 4; 1106 idx++; 1107 if (idx > raw->curlen) 1108 goto fail_len; 1109 1110 import_guid(&msg->u.resource_stat.guid, &raw->msg[idx]); 1111 idx += 16; 1112 if (idx > raw->curlen) 1113 goto fail_len; 1114 1115 msg->u.resource_stat.available_pbn = (raw->msg[idx] << 8) | (raw->msg[idx + 1]); 1116 idx++; 1117 return true; 1118 fail_len: 1119 drm_dbg_kms(mgr->dev, "resource status reply parse length fail %d %d\n", idx, raw->curlen); 1120 return false; 1121 } 1122 1123 static bool drm_dp_sideband_parse_req(const struct drm_dp_mst_topology_mgr *mgr, 1124 struct drm_dp_sideband_msg_rx *raw, 1125 struct drm_dp_sideband_msg_req_body *msg) 1126 { 1127 memset(msg, 0, sizeof(*msg)); 1128 msg->req_type = (raw->msg[0] & 0x7f); 1129 1130 switch (msg->req_type) { 1131 case DP_CONNECTION_STATUS_NOTIFY: 1132 return drm_dp_sideband_parse_connection_status_notify(mgr, raw, msg); 1133 case DP_RESOURCE_STATUS_NOTIFY: 1134 return drm_dp_sideband_parse_resource_status_notify(mgr, raw, msg); 1135 default: 1136 drm_err(mgr->dev, "Got unknown request 0x%02x (%s)\n", 1137 msg->req_type, drm_dp_mst_req_type_str(msg->req_type)); 1138 return false; 1139 } 1140 } 1141 1142 static void build_dpcd_write(struct drm_dp_sideband_msg_tx *msg, 1143 u8 port_num, u32 offset, u8 num_bytes, u8 *bytes) 1144 { 1145 struct drm_dp_sideband_msg_req_body req; 1146 1147 req.req_type = DP_REMOTE_DPCD_WRITE; 1148 req.u.dpcd_write.port_number = port_num; 1149 req.u.dpcd_write.dpcd_address = offset; 1150 req.u.dpcd_write.num_bytes = num_bytes; 1151 req.u.dpcd_write.bytes = bytes; 1152 drm_dp_encode_sideband_req(&req, msg); 1153 } 1154 1155 static void build_link_address(struct drm_dp_sideband_msg_tx *msg) 1156 { 1157 struct drm_dp_sideband_msg_req_body req; 1158 1159 req.req_type = DP_LINK_ADDRESS; 1160 drm_dp_encode_sideband_req(&req, msg); 1161 } 1162 1163 static void build_clear_payload_id_table(struct drm_dp_sideband_msg_tx *msg) 1164 { 1165 struct drm_dp_sideband_msg_req_body req; 1166 1167 req.req_type = DP_CLEAR_PAYLOAD_ID_TABLE; 1168 drm_dp_encode_sideband_req(&req, msg); 1169 msg->path_msg = true; 1170 } 1171 1172 static int build_enum_path_resources(struct drm_dp_sideband_msg_tx *msg, 1173 int port_num) 1174 { 1175 struct drm_dp_sideband_msg_req_body req; 1176 1177 req.req_type = DP_ENUM_PATH_RESOURCES; 1178 req.u.port_num.port_number = port_num; 1179 drm_dp_encode_sideband_req(&req, msg); 1180 msg->path_msg = true; 1181 return 0; 1182 } 1183 1184 static void build_allocate_payload(struct drm_dp_sideband_msg_tx *msg, 1185 int port_num, 1186 u8 vcpi, uint16_t pbn, 1187 u8 number_sdp_streams, 1188 u8 *sdp_stream_sink) 1189 { 1190 struct drm_dp_sideband_msg_req_body req; 1191 1192 memset(&req, 0, sizeof(req)); 1193 req.req_type = DP_ALLOCATE_PAYLOAD; 1194 req.u.allocate_payload.port_number = port_num; 1195 req.u.allocate_payload.vcpi = vcpi; 1196 req.u.allocate_payload.pbn = pbn; 1197 req.u.allocate_payload.number_sdp_streams = number_sdp_streams; 1198 memcpy(req.u.allocate_payload.sdp_stream_sink, sdp_stream_sink, 1199 number_sdp_streams); 1200 drm_dp_encode_sideband_req(&req, msg); 1201 msg->path_msg = true; 1202 } 1203 1204 static void build_power_updown_phy(struct drm_dp_sideband_msg_tx *msg, 1205 int port_num, bool power_up) 1206 { 1207 struct drm_dp_sideband_msg_req_body req; 1208 1209 if (power_up) 1210 req.req_type = DP_POWER_UP_PHY; 1211 else 1212 req.req_type = DP_POWER_DOWN_PHY; 1213 1214 req.u.port_num.port_number = port_num; 1215 drm_dp_encode_sideband_req(&req, msg); 1216 msg->path_msg = true; 1217 } 1218 1219 static int 1220 build_query_stream_enc_status(struct drm_dp_sideband_msg_tx *msg, u8 stream_id, 1221 u8 *q_id) 1222 { 1223 struct drm_dp_sideband_msg_req_body req; 1224 1225 req.req_type = DP_QUERY_STREAM_ENC_STATUS; 1226 req.u.enc_status.stream_id = stream_id; 1227 memcpy(req.u.enc_status.client_id, q_id, 1228 sizeof(req.u.enc_status.client_id)); 1229 req.u.enc_status.stream_event = 0; 1230 req.u.enc_status.valid_stream_event = false; 1231 req.u.enc_status.stream_behavior = 0; 1232 req.u.enc_status.valid_stream_behavior = false; 1233 1234 drm_dp_encode_sideband_req(&req, msg); 1235 return 0; 1236 } 1237 1238 static bool check_txmsg_state(struct drm_dp_mst_topology_mgr *mgr, 1239 struct drm_dp_sideband_msg_tx *txmsg) 1240 { 1241 unsigned int state; 1242 1243 /* 1244 * All updates to txmsg->state are protected by mgr->qlock, and the two 1245 * cases we check here are terminal states. For those the barriers 1246 * provided by the wake_up/wait_event pair are enough. 1247 */ 1248 state = READ_ONCE(txmsg->state); 1249 return (state == DRM_DP_SIDEBAND_TX_RX || 1250 state == DRM_DP_SIDEBAND_TX_TIMEOUT); 1251 } 1252 1253 static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb, 1254 struct drm_dp_sideband_msg_tx *txmsg) 1255 { 1256 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 1257 unsigned long wait_timeout = msecs_to_jiffies(4000); 1258 unsigned long wait_expires = jiffies + wait_timeout; 1259 int ret; 1260 1261 for (;;) { 1262 /* 1263 * If the driver provides a way for this, change to 1264 * poll-waiting for the MST reply interrupt if we didn't receive 1265 * it for 50 msec. This would cater for cases where the HPD 1266 * pulse signal got lost somewhere, even though the sink raised 1267 * the corresponding MST interrupt correctly. One example is the 1268 * Club 3D CAC-1557 TypeC -> DP adapter which for some reason 1269 * filters out short pulses with a duration less than ~540 usec. 1270 * 1271 * The poll period is 50 msec to avoid missing an interrupt 1272 * after the sink has cleared it (after a 110msec timeout 1273 * since it raised the interrupt). 1274 */ 1275 ret = wait_event_timeout(mgr->tx_waitq, 1276 check_txmsg_state(mgr, txmsg), 1277 mgr->cbs->poll_hpd_irq ? 1278 msecs_to_jiffies(50) : 1279 wait_timeout); 1280 1281 if (ret || !mgr->cbs->poll_hpd_irq || 1282 time_after(jiffies, wait_expires)) 1283 break; 1284 1285 mgr->cbs->poll_hpd_irq(mgr); 1286 } 1287 1288 mutex_lock(&mgr->qlock); 1289 if (ret > 0) { 1290 if (txmsg->state == DRM_DP_SIDEBAND_TX_TIMEOUT) { 1291 ret = -EIO; 1292 goto out; 1293 } 1294 } else { 1295 drm_dbg_kms(mgr->dev, "timedout msg send %p %d %d\n", 1296 txmsg, txmsg->state, txmsg->seqno); 1297 1298 /* dump some state */ 1299 ret = -EIO; 1300 1301 /* remove from q */ 1302 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED || 1303 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND || 1304 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) 1305 list_del(&txmsg->next); 1306 } 1307 out: 1308 if (unlikely(ret == -EIO) && drm_debug_enabled(DRM_UT_DP)) { 1309 struct drm_printer p = drm_dbg_printer(mgr->dev, DRM_UT_DP, 1310 DBG_PREFIX); 1311 1312 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 1313 } 1314 mutex_unlock(&mgr->qlock); 1315 1316 drm_dp_mst_kick_tx(mgr); 1317 return ret; 1318 } 1319 1320 static struct drm_dp_mst_branch *drm_dp_add_mst_branch_device(u8 lct, u8 *rad) 1321 { 1322 struct drm_dp_mst_branch *mstb; 1323 1324 mstb = kzalloc(sizeof(*mstb), GFP_KERNEL); 1325 if (!mstb) 1326 return NULL; 1327 1328 mstb->lct = lct; 1329 if (lct > 1) 1330 memcpy(mstb->rad, rad, lct / 2); 1331 INIT_LIST_HEAD(&mstb->ports); 1332 kref_init(&mstb->topology_kref); 1333 kref_init(&mstb->malloc_kref); 1334 return mstb; 1335 } 1336 1337 static void drm_dp_free_mst_branch_device(struct kref *kref) 1338 { 1339 struct drm_dp_mst_branch *mstb = 1340 container_of(kref, struct drm_dp_mst_branch, malloc_kref); 1341 1342 if (mstb->port_parent) 1343 drm_dp_mst_put_port_malloc(mstb->port_parent); 1344 1345 kfree(mstb); 1346 } 1347 1348 /** 1349 * DOC: Branch device and port refcounting 1350 * 1351 * Topology refcount overview 1352 * ~~~~~~~~~~~~~~~~~~~~~~~~~~ 1353 * 1354 * The refcounting schemes for &struct drm_dp_mst_branch and &struct 1355 * drm_dp_mst_port are somewhat unusual. Both ports and branch devices have 1356 * two different kinds of refcounts: topology refcounts, and malloc refcounts. 1357 * 1358 * Topology refcounts are not exposed to drivers, and are handled internally 1359 * by the DP MST helpers. The helpers use them in order to prevent the 1360 * in-memory topology state from being changed in the middle of critical 1361 * operations like changing the internal state of payload allocations. This 1362 * means each branch and port will be considered to be connected to the rest 1363 * of the topology until its topology refcount reaches zero. Additionally, 1364 * for ports this means that their associated &struct drm_connector will stay 1365 * registered with userspace until the port's refcount reaches 0. 1366 * 1367 * Malloc refcount overview 1368 * ~~~~~~~~~~~~~~~~~~~~~~~~ 1369 * 1370 * Malloc references are used to keep a &struct drm_dp_mst_port or &struct 1371 * drm_dp_mst_branch allocated even after all of its topology references have 1372 * been dropped, so that the driver or MST helpers can safely access each 1373 * branch's last known state before it was disconnected from the topology. 1374 * When the malloc refcount of a port or branch reaches 0, the memory 1375 * allocation containing the &struct drm_dp_mst_branch or &struct 1376 * drm_dp_mst_port respectively will be freed. 1377 * 1378 * For &struct drm_dp_mst_branch, malloc refcounts are not currently exposed 1379 * to drivers. As of writing this documentation, there are no drivers that 1380 * have a usecase for accessing &struct drm_dp_mst_branch outside of the MST 1381 * helpers. Exposing this API to drivers in a race-free manner would take more 1382 * tweaking of the refcounting scheme, however patches are welcome provided 1383 * there is a legitimate driver usecase for this. 1384 * 1385 * Refcount relationships in a topology 1386 * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1387 * 1388 * Let's take a look at why the relationship between topology and malloc 1389 * refcounts is designed the way it is. 1390 * 1391 * .. kernel-figure:: dp-mst/topology-figure-1.dot 1392 * 1393 * An example of topology and malloc refs in a DP MST topology with two 1394 * active payloads. Topology refcount increments are indicated by solid 1395 * lines, and malloc refcount increments are indicated by dashed lines. 1396 * Each starts from the branch which incremented the refcount, and ends at 1397 * the branch to which the refcount belongs to, i.e. the arrow points the 1398 * same way as the C pointers used to reference a structure. 1399 * 1400 * As you can see in the above figure, every branch increments the topology 1401 * refcount of its children, and increments the malloc refcount of its 1402 * parent. Additionally, every payload increments the malloc refcount of its 1403 * assigned port by 1. 1404 * 1405 * So, what would happen if MSTB #3 from the above figure was unplugged from 1406 * the system, but the driver hadn't yet removed payload #2 from port #3? The 1407 * topology would start to look like the figure below. 1408 * 1409 * .. kernel-figure:: dp-mst/topology-figure-2.dot 1410 * 1411 * Ports and branch devices which have been released from memory are 1412 * colored grey, and references which have been removed are colored red. 1413 * 1414 * Whenever a port or branch device's topology refcount reaches zero, it will 1415 * decrement the topology refcounts of all its children, the malloc refcount 1416 * of its parent, and finally its own malloc refcount. For MSTB #4 and port 1417 * #4, this means they both have been disconnected from the topology and freed 1418 * from memory. But, because payload #2 is still holding a reference to port 1419 * #3, port #3 is removed from the topology but its &struct drm_dp_mst_port 1420 * is still accessible from memory. This also means port #3 has not yet 1421 * decremented the malloc refcount of MSTB #3, so its &struct 1422 * drm_dp_mst_branch will also stay allocated in memory until port #3's 1423 * malloc refcount reaches 0. 1424 * 1425 * This relationship is necessary because in order to release payload #2, we 1426 * need to be able to figure out the last relative of port #3 that's still 1427 * connected to the topology. In this case, we would travel up the topology as 1428 * shown below. 1429 * 1430 * .. kernel-figure:: dp-mst/topology-figure-3.dot 1431 * 1432 * And finally, remove payload #2 by communicating with port #2 through 1433 * sideband transactions. 1434 */ 1435 1436 /** 1437 * drm_dp_mst_get_mstb_malloc() - Increment the malloc refcount of a branch 1438 * device 1439 * @mstb: The &struct drm_dp_mst_branch to increment the malloc refcount of 1440 * 1441 * Increments &drm_dp_mst_branch.malloc_kref. When 1442 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb 1443 * will be released and @mstb may no longer be used. 1444 * 1445 * See also: drm_dp_mst_put_mstb_malloc() 1446 */ 1447 static void 1448 drm_dp_mst_get_mstb_malloc(struct drm_dp_mst_branch *mstb) 1449 { 1450 kref_get(&mstb->malloc_kref); 1451 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref)); 1452 } 1453 1454 /** 1455 * drm_dp_mst_put_mstb_malloc() - Decrement the malloc refcount of a branch 1456 * device 1457 * @mstb: The &struct drm_dp_mst_branch to decrement the malloc refcount of 1458 * 1459 * Decrements &drm_dp_mst_branch.malloc_kref. When 1460 * &drm_dp_mst_branch.malloc_kref reaches 0, the memory allocation for @mstb 1461 * will be released and @mstb may no longer be used. 1462 * 1463 * See also: drm_dp_mst_get_mstb_malloc() 1464 */ 1465 static void 1466 drm_dp_mst_put_mstb_malloc(struct drm_dp_mst_branch *mstb) 1467 { 1468 drm_dbg(mstb->mgr->dev, "mstb %p (%d)\n", mstb, kref_read(&mstb->malloc_kref) - 1); 1469 kref_put(&mstb->malloc_kref, drm_dp_free_mst_branch_device); 1470 } 1471 1472 static void drm_dp_free_mst_port(struct kref *kref) 1473 { 1474 struct drm_dp_mst_port *port = 1475 container_of(kref, struct drm_dp_mst_port, malloc_kref); 1476 1477 drm_dp_mst_put_mstb_malloc(port->parent); 1478 kfree(port); 1479 } 1480 1481 /** 1482 * drm_dp_mst_get_port_malloc() - Increment the malloc refcount of an MST port 1483 * @port: The &struct drm_dp_mst_port to increment the malloc refcount of 1484 * 1485 * Increments &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref 1486 * reaches 0, the memory allocation for @port will be released and @port may 1487 * no longer be used. 1488 * 1489 * Because @port could potentially be freed at any time by the DP MST helpers 1490 * if &drm_dp_mst_port.malloc_kref reaches 0, including during a call to this 1491 * function, drivers that which to make use of &struct drm_dp_mst_port should 1492 * ensure that they grab at least one main malloc reference to their MST ports 1493 * in &drm_dp_mst_topology_cbs.add_connector. This callback is called before 1494 * there is any chance for &drm_dp_mst_port.malloc_kref to reach 0. 1495 * 1496 * See also: drm_dp_mst_put_port_malloc() 1497 */ 1498 void 1499 drm_dp_mst_get_port_malloc(struct drm_dp_mst_port *port) 1500 { 1501 kref_get(&port->malloc_kref); 1502 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref)); 1503 } 1504 EXPORT_SYMBOL(drm_dp_mst_get_port_malloc); 1505 1506 /** 1507 * drm_dp_mst_put_port_malloc() - Decrement the malloc refcount of an MST port 1508 * @port: The &struct drm_dp_mst_port to decrement the malloc refcount of 1509 * 1510 * Decrements &drm_dp_mst_port.malloc_kref. When &drm_dp_mst_port.malloc_kref 1511 * reaches 0, the memory allocation for @port will be released and @port may 1512 * no longer be used. 1513 * 1514 * See also: drm_dp_mst_get_port_malloc() 1515 */ 1516 void 1517 drm_dp_mst_put_port_malloc(struct drm_dp_mst_port *port) 1518 { 1519 drm_dbg(port->mgr->dev, "port %p (%d)\n", port, kref_read(&port->malloc_kref) - 1); 1520 kref_put(&port->malloc_kref, drm_dp_free_mst_port); 1521 } 1522 EXPORT_SYMBOL(drm_dp_mst_put_port_malloc); 1523 1524 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 1525 1526 #define STACK_DEPTH 8 1527 1528 static noinline void 1529 __topology_ref_save(struct drm_dp_mst_topology_mgr *mgr, 1530 struct drm_dp_mst_topology_ref_history *history, 1531 enum drm_dp_mst_topology_ref_type type) 1532 { 1533 struct drm_dp_mst_topology_ref_entry *entry = NULL; 1534 depot_stack_handle_t backtrace; 1535 ulong stack_entries[STACK_DEPTH]; 1536 uint n; 1537 int i; 1538 1539 n = stack_trace_save(stack_entries, ARRAY_SIZE(stack_entries), 1); 1540 backtrace = stack_depot_save(stack_entries, n, GFP_KERNEL); 1541 if (!backtrace) 1542 return; 1543 1544 /* Try to find an existing entry for this backtrace */ 1545 for (i = 0; i < history->len; i++) { 1546 if (history->entries[i].backtrace == backtrace) { 1547 entry = &history->entries[i]; 1548 break; 1549 } 1550 } 1551 1552 /* Otherwise add one */ 1553 if (!entry) { 1554 struct drm_dp_mst_topology_ref_entry *new; 1555 int new_len = history->len + 1; 1556 1557 new = krealloc(history->entries, sizeof(*new) * new_len, 1558 GFP_KERNEL); 1559 if (!new) 1560 return; 1561 1562 entry = &new[history->len]; 1563 history->len = new_len; 1564 history->entries = new; 1565 1566 entry->backtrace = backtrace; 1567 entry->type = type; 1568 entry->count = 0; 1569 } 1570 entry->count++; 1571 entry->ts_nsec = ktime_get_ns(); 1572 } 1573 1574 static int 1575 topology_ref_history_cmp(const void *a, const void *b) 1576 { 1577 const struct drm_dp_mst_topology_ref_entry *entry_a = a, *entry_b = b; 1578 1579 if (entry_a->ts_nsec > entry_b->ts_nsec) 1580 return 1; 1581 else if (entry_a->ts_nsec < entry_b->ts_nsec) 1582 return -1; 1583 else 1584 return 0; 1585 } 1586 1587 static inline const char * 1588 topology_ref_type_to_str(enum drm_dp_mst_topology_ref_type type) 1589 { 1590 if (type == DRM_DP_MST_TOPOLOGY_REF_GET) 1591 return "get"; 1592 else 1593 return "put"; 1594 } 1595 1596 static void 1597 __dump_topology_ref_history(struct drm_device *drm, 1598 struct drm_dp_mst_topology_ref_history *history, 1599 void *ptr, const char *type_str) 1600 { 1601 struct drm_printer p = drm_dbg_printer(drm, DRM_UT_DP, 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->mgr->dev, &mstb->topology_ref_history, 1644 mstb, "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->mgr->dev, &port->topology_ref_history, 1651 port, "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, guid_t *guid) 2178 { 2179 int ret = 0; 2180 2181 guid_copy(&mstb->guid, guid); 2182 2183 if (!drm_dp_validate_guid(mstb->mgr, &mstb->guid)) { 2184 u8 buf[UUID_SIZE]; 2185 2186 export_guid(buf, &mstb->guid); 2187 2188 if (mstb->port_parent) { 2189 ret = drm_dp_send_dpcd_write(mstb->mgr, 2190 mstb->port_parent, 2191 DP_GUID, sizeof(buf), buf); 2192 } else { 2193 ret = drm_dp_dpcd_write(mstb->mgr->aux, 2194 DP_GUID, buf, sizeof(buf)); 2195 } 2196 } 2197 2198 if (ret < 16 && ret > 0) 2199 return -EPROTO; 2200 2201 return ret == 16 ? 0 : ret; 2202 } 2203 2204 static void build_mst_prop_path(const struct drm_dp_mst_branch *mstb, 2205 int pnum, 2206 char *proppath, 2207 size_t proppath_size) 2208 { 2209 int i; 2210 char temp[8]; 2211 2212 snprintf(proppath, proppath_size, "mst:%d", mstb->mgr->conn_base_id); 2213 for (i = 0; i < (mstb->lct - 1); i++) { 2214 int shift = (i % 2) ? 0 : 4; 2215 int port_num = (mstb->rad[i / 2] >> shift) & 0xf; 2216 2217 snprintf(temp, sizeof(temp), "-%d", port_num); 2218 strlcat(proppath, temp, proppath_size); 2219 } 2220 snprintf(temp, sizeof(temp), "-%d", pnum); 2221 strlcat(proppath, temp, proppath_size); 2222 } 2223 2224 /** 2225 * drm_dp_mst_connector_late_register() - Late MST connector registration 2226 * @connector: The MST connector 2227 * @port: The MST port for this connector 2228 * 2229 * Helper to register the remote aux device for this MST port. Drivers should 2230 * call this from their mst connector's late_register hook to enable MST aux 2231 * devices. 2232 * 2233 * Return: 0 on success, negative error code on failure. 2234 */ 2235 int drm_dp_mst_connector_late_register(struct drm_connector *connector, 2236 struct drm_dp_mst_port *port) 2237 { 2238 drm_dbg_kms(port->mgr->dev, "registering %s remote bus for %s\n", 2239 port->aux.name, connector->kdev->kobj.name); 2240 2241 port->aux.dev = connector->kdev; 2242 return drm_dp_aux_register_devnode(&port->aux); 2243 } 2244 EXPORT_SYMBOL(drm_dp_mst_connector_late_register); 2245 2246 /** 2247 * drm_dp_mst_connector_early_unregister() - Early MST connector unregistration 2248 * @connector: The MST connector 2249 * @port: The MST port for this connector 2250 * 2251 * Helper to unregister the remote aux device for this MST port, registered by 2252 * drm_dp_mst_connector_late_register(). Drivers should call this from their mst 2253 * connector's early_unregister hook. 2254 */ 2255 void drm_dp_mst_connector_early_unregister(struct drm_connector *connector, 2256 struct drm_dp_mst_port *port) 2257 { 2258 drm_dbg_kms(port->mgr->dev, "unregistering %s remote bus for %s\n", 2259 port->aux.name, connector->kdev->kobj.name); 2260 drm_dp_aux_unregister_devnode(&port->aux); 2261 } 2262 EXPORT_SYMBOL(drm_dp_mst_connector_early_unregister); 2263 2264 static void 2265 drm_dp_mst_port_add_connector(struct drm_dp_mst_branch *mstb, 2266 struct drm_dp_mst_port *port) 2267 { 2268 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 2269 char proppath[255]; 2270 int ret; 2271 2272 build_mst_prop_path(mstb, port->port_num, proppath, sizeof(proppath)); 2273 port->connector = mgr->cbs->add_connector(mgr, port, proppath); 2274 if (!port->connector) { 2275 ret = -ENOMEM; 2276 goto error; 2277 } 2278 2279 if (port->pdt != DP_PEER_DEVICE_NONE && 2280 drm_dp_mst_is_end_device(port->pdt, port->mcs) && 2281 drm_dp_mst_port_is_logical(port)) 2282 port->cached_edid = drm_edid_read_ddc(port->connector, 2283 &port->aux.ddc); 2284 2285 drm_connector_register(port->connector); 2286 return; 2287 2288 error: 2289 drm_err(mgr->dev, "Failed to create connector for port %p: %d\n", port, ret); 2290 } 2291 2292 /* 2293 * Drop a topology reference, and unlink the port from the in-memory topology 2294 * layout 2295 */ 2296 static void 2297 drm_dp_mst_topology_unlink_port(struct drm_dp_mst_topology_mgr *mgr, 2298 struct drm_dp_mst_port *port) 2299 { 2300 mutex_lock(&mgr->lock); 2301 port->parent->num_ports--; 2302 list_del(&port->next); 2303 mutex_unlock(&mgr->lock); 2304 drm_dp_mst_topology_put_port(port); 2305 } 2306 2307 static struct drm_dp_mst_port * 2308 drm_dp_mst_add_port(struct drm_device *dev, 2309 struct drm_dp_mst_topology_mgr *mgr, 2310 struct drm_dp_mst_branch *mstb, u8 port_number) 2311 { 2312 struct drm_dp_mst_port *port = kzalloc(sizeof(*port), GFP_KERNEL); 2313 2314 if (!port) 2315 return NULL; 2316 2317 kref_init(&port->topology_kref); 2318 kref_init(&port->malloc_kref); 2319 port->parent = mstb; 2320 port->port_num = port_number; 2321 port->mgr = mgr; 2322 port->aux.name = "DPMST"; 2323 port->aux.dev = dev->dev; 2324 port->aux.is_remote = true; 2325 2326 /* initialize the MST downstream port's AUX crc work queue */ 2327 port->aux.drm_dev = dev; 2328 drm_dp_remote_aux_init(&port->aux); 2329 2330 /* 2331 * Make sure the memory allocation for our parent branch stays 2332 * around until our own memory allocation is released 2333 */ 2334 drm_dp_mst_get_mstb_malloc(mstb); 2335 2336 return port; 2337 } 2338 2339 static int 2340 drm_dp_mst_handle_link_address_port(struct drm_dp_mst_branch *mstb, 2341 struct drm_device *dev, 2342 struct drm_dp_link_addr_reply_port *port_msg) 2343 { 2344 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 2345 struct drm_dp_mst_port *port; 2346 int old_ddps = 0, ret; 2347 u8 new_pdt = DP_PEER_DEVICE_NONE; 2348 bool new_mcs = 0; 2349 bool created = false, send_link_addr = false, changed = false; 2350 2351 port = drm_dp_get_port(mstb, port_msg->port_number); 2352 if (!port) { 2353 port = drm_dp_mst_add_port(dev, mgr, mstb, 2354 port_msg->port_number); 2355 if (!port) 2356 return -ENOMEM; 2357 created = true; 2358 changed = true; 2359 } else if (!port->input && port_msg->input_port && port->connector) { 2360 /* Since port->connector can't be changed here, we create a 2361 * new port if input_port changes from 0 to 1 2362 */ 2363 drm_dp_mst_topology_unlink_port(mgr, port); 2364 drm_dp_mst_topology_put_port(port); 2365 port = drm_dp_mst_add_port(dev, mgr, mstb, 2366 port_msg->port_number); 2367 if (!port) 2368 return -ENOMEM; 2369 changed = true; 2370 created = true; 2371 } else if (port->input && !port_msg->input_port) { 2372 changed = true; 2373 } else if (port->connector) { 2374 /* We're updating a port that's exposed to userspace, so do it 2375 * under lock 2376 */ 2377 drm_modeset_lock(&mgr->base.lock, NULL); 2378 2379 old_ddps = port->ddps; 2380 changed = port->ddps != port_msg->ddps || 2381 (port->ddps && 2382 (port->ldps != port_msg->legacy_device_plug_status || 2383 port->dpcd_rev != port_msg->dpcd_revision || 2384 port->mcs != port_msg->mcs || 2385 port->pdt != port_msg->peer_device_type || 2386 port->num_sdp_stream_sinks != 2387 port_msg->num_sdp_stream_sinks)); 2388 } 2389 2390 port->input = port_msg->input_port; 2391 if (!port->input) 2392 new_pdt = port_msg->peer_device_type; 2393 new_mcs = port_msg->mcs; 2394 port->ddps = port_msg->ddps; 2395 port->ldps = port_msg->legacy_device_plug_status; 2396 port->dpcd_rev = port_msg->dpcd_revision; 2397 port->num_sdp_streams = port_msg->num_sdp_streams; 2398 port->num_sdp_stream_sinks = port_msg->num_sdp_stream_sinks; 2399 2400 /* manage mstb port lists with mgr lock - take a reference 2401 for this list */ 2402 if (created) { 2403 mutex_lock(&mgr->lock); 2404 drm_dp_mst_topology_get_port(port); 2405 list_add(&port->next, &mstb->ports); 2406 mstb->num_ports++; 2407 mutex_unlock(&mgr->lock); 2408 } 2409 2410 /* 2411 * Reprobe PBN caps on both hotplug, and when re-probing the link 2412 * for our parent mstb 2413 */ 2414 if (old_ddps != port->ddps || !created) { 2415 if (port->ddps && !port->input) { 2416 ret = drm_dp_send_enum_path_resources(mgr, mstb, 2417 port); 2418 if (ret == 1) 2419 changed = true; 2420 } else { 2421 port->full_pbn = 0; 2422 } 2423 } 2424 2425 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs); 2426 if (ret == 1) { 2427 send_link_addr = true; 2428 } else if (ret < 0) { 2429 drm_err(dev, "Failed to change PDT on port %p: %d\n", port, ret); 2430 goto fail; 2431 } 2432 2433 /* 2434 * If this port wasn't just created, then we're reprobing because 2435 * we're coming out of suspend. In this case, always resend the link 2436 * address if there's an MSTB on this port 2437 */ 2438 if (!created && port->pdt == DP_PEER_DEVICE_MST_BRANCHING && 2439 port->mcs) 2440 send_link_addr = true; 2441 2442 if (port->connector) 2443 drm_modeset_unlock(&mgr->base.lock); 2444 else if (!port->input) 2445 drm_dp_mst_port_add_connector(mstb, port); 2446 2447 if (send_link_addr && port->mstb) { 2448 ret = drm_dp_send_link_address(mgr, port->mstb); 2449 if (ret == 1) /* MSTB below us changed */ 2450 changed = true; 2451 else if (ret < 0) 2452 goto fail_put; 2453 } 2454 2455 /* put reference to this port */ 2456 drm_dp_mst_topology_put_port(port); 2457 return changed; 2458 2459 fail: 2460 drm_dp_mst_topology_unlink_port(mgr, port); 2461 if (port->connector) 2462 drm_modeset_unlock(&mgr->base.lock); 2463 fail_put: 2464 drm_dp_mst_topology_put_port(port); 2465 return ret; 2466 } 2467 2468 static int 2469 drm_dp_mst_handle_conn_stat(struct drm_dp_mst_branch *mstb, 2470 struct drm_dp_connection_status_notify *conn_stat) 2471 { 2472 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 2473 struct drm_dp_mst_port *port; 2474 int old_ddps, ret; 2475 u8 new_pdt; 2476 bool new_mcs; 2477 bool dowork = false, create_connector = false; 2478 2479 port = drm_dp_get_port(mstb, conn_stat->port_number); 2480 if (!port) 2481 return 0; 2482 2483 if (port->connector) { 2484 if (!port->input && conn_stat->input_port) { 2485 /* 2486 * We can't remove a connector from an already exposed 2487 * port, so just throw the port out and make sure we 2488 * reprobe the link address of it's parent MSTB 2489 */ 2490 drm_dp_mst_topology_unlink_port(mgr, port); 2491 mstb->link_address_sent = false; 2492 dowork = true; 2493 goto out; 2494 } 2495 2496 /* Locking is only needed if the port's exposed to userspace */ 2497 drm_modeset_lock(&mgr->base.lock, NULL); 2498 } else if (port->input && !conn_stat->input_port) { 2499 create_connector = true; 2500 /* Reprobe link address so we get num_sdp_streams */ 2501 mstb->link_address_sent = false; 2502 dowork = true; 2503 } 2504 2505 old_ddps = port->ddps; 2506 port->input = conn_stat->input_port; 2507 port->ldps = conn_stat->legacy_device_plug_status; 2508 port->ddps = conn_stat->displayport_device_plug_status; 2509 2510 if (old_ddps != port->ddps) { 2511 if (port->ddps && !port->input) 2512 drm_dp_send_enum_path_resources(mgr, mstb, port); 2513 else 2514 port->full_pbn = 0; 2515 } 2516 2517 new_pdt = port->input ? DP_PEER_DEVICE_NONE : conn_stat->peer_device_type; 2518 new_mcs = conn_stat->message_capability_status; 2519 ret = drm_dp_port_set_pdt(port, new_pdt, new_mcs); 2520 if (ret == 1) { 2521 dowork = true; 2522 } else if (ret < 0) { 2523 drm_err(mgr->dev, "Failed to change PDT for port %p: %d\n", port, ret); 2524 dowork = false; 2525 } 2526 2527 if (port->connector) 2528 drm_modeset_unlock(&mgr->base.lock); 2529 else if (create_connector) 2530 drm_dp_mst_port_add_connector(mstb, port); 2531 2532 out: 2533 drm_dp_mst_topology_put_port(port); 2534 return dowork; 2535 } 2536 2537 static struct drm_dp_mst_branch *drm_dp_get_mst_branch_device(struct drm_dp_mst_topology_mgr *mgr, 2538 u8 lct, u8 *rad) 2539 { 2540 struct drm_dp_mst_branch *mstb; 2541 struct drm_dp_mst_port *port; 2542 int i, ret; 2543 /* find the port by iterating down */ 2544 2545 mutex_lock(&mgr->lock); 2546 mstb = mgr->mst_primary; 2547 2548 if (!mstb) 2549 goto out; 2550 2551 for (i = 0; i < lct - 1; i++) { 2552 int shift = (i % 2) ? 0 : 4; 2553 int port_num = (rad[i / 2] >> shift) & 0xf; 2554 2555 list_for_each_entry(port, &mstb->ports, next) { 2556 if (port->port_num == port_num) { 2557 mstb = port->mstb; 2558 if (!mstb) { 2559 drm_err(mgr->dev, 2560 "failed to lookup MSTB with lct %d, rad %02x\n", 2561 lct, rad[0]); 2562 goto out; 2563 } 2564 2565 break; 2566 } 2567 } 2568 } 2569 ret = drm_dp_mst_topology_try_get_mstb(mstb); 2570 if (!ret) 2571 mstb = NULL; 2572 out: 2573 mutex_unlock(&mgr->lock); 2574 return mstb; 2575 } 2576 2577 static struct drm_dp_mst_branch * 2578 get_mst_branch_device_by_guid_helper(struct drm_dp_mst_branch *mstb, 2579 const guid_t *guid) 2580 { 2581 struct drm_dp_mst_branch *found_mstb; 2582 struct drm_dp_mst_port *port; 2583 2584 if (!mstb) 2585 return NULL; 2586 2587 if (guid_equal(&mstb->guid, guid)) 2588 return mstb; 2589 2590 list_for_each_entry(port, &mstb->ports, next) { 2591 found_mstb = get_mst_branch_device_by_guid_helper(port->mstb, guid); 2592 2593 if (found_mstb) 2594 return found_mstb; 2595 } 2596 2597 return NULL; 2598 } 2599 2600 static struct drm_dp_mst_branch * 2601 drm_dp_get_mst_branch_device_by_guid(struct drm_dp_mst_topology_mgr *mgr, 2602 const guid_t *guid) 2603 { 2604 struct drm_dp_mst_branch *mstb; 2605 int ret; 2606 2607 /* find the port by iterating down */ 2608 mutex_lock(&mgr->lock); 2609 2610 mstb = get_mst_branch_device_by_guid_helper(mgr->mst_primary, guid); 2611 if (mstb) { 2612 ret = drm_dp_mst_topology_try_get_mstb(mstb); 2613 if (!ret) 2614 mstb = NULL; 2615 } 2616 2617 mutex_unlock(&mgr->lock); 2618 return mstb; 2619 } 2620 2621 static int drm_dp_check_and_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 2622 struct drm_dp_mst_branch *mstb) 2623 { 2624 struct drm_dp_mst_port *port; 2625 int ret; 2626 bool changed = false; 2627 2628 if (!mstb->link_address_sent) { 2629 ret = drm_dp_send_link_address(mgr, mstb); 2630 if (ret == 1) 2631 changed = true; 2632 else if (ret < 0) 2633 return ret; 2634 } 2635 2636 list_for_each_entry(port, &mstb->ports, next) { 2637 if (port->input || !port->ddps || !port->mstb) 2638 continue; 2639 2640 ret = drm_dp_check_and_send_link_address(mgr, port->mstb); 2641 if (ret == 1) 2642 changed = true; 2643 else if (ret < 0) 2644 return ret; 2645 } 2646 2647 return changed; 2648 } 2649 2650 static void drm_dp_mst_link_probe_work(struct work_struct *work) 2651 { 2652 struct drm_dp_mst_topology_mgr *mgr = 2653 container_of(work, struct drm_dp_mst_topology_mgr, work); 2654 struct drm_device *dev = mgr->dev; 2655 struct drm_dp_mst_branch *mstb; 2656 int ret; 2657 bool clear_payload_id_table; 2658 2659 mutex_lock(&mgr->probe_lock); 2660 2661 mutex_lock(&mgr->lock); 2662 clear_payload_id_table = !mgr->payload_id_table_cleared; 2663 mgr->payload_id_table_cleared = true; 2664 2665 mstb = mgr->mst_primary; 2666 if (mstb) { 2667 ret = drm_dp_mst_topology_try_get_mstb(mstb); 2668 if (!ret) 2669 mstb = NULL; 2670 } 2671 mutex_unlock(&mgr->lock); 2672 if (!mstb) { 2673 mutex_unlock(&mgr->probe_lock); 2674 return; 2675 } 2676 2677 /* 2678 * Certain branch devices seem to incorrectly report an available_pbn 2679 * of 0 on downstream sinks, even after clearing the 2680 * DP_PAYLOAD_ALLOCATE_* registers in 2681 * drm_dp_mst_topology_mgr_set_mst(). Namely, the CableMatters USB-C 2682 * 2x DP hub. Sending a CLEAR_PAYLOAD_ID_TABLE message seems to make 2683 * things work again. 2684 */ 2685 if (clear_payload_id_table) { 2686 drm_dbg_kms(dev, "Clearing payload ID table\n"); 2687 drm_dp_send_clear_payload_id_table(mgr, mstb); 2688 } 2689 2690 ret = drm_dp_check_and_send_link_address(mgr, mstb); 2691 drm_dp_mst_topology_put_mstb(mstb); 2692 2693 mutex_unlock(&mgr->probe_lock); 2694 if (ret > 0) 2695 drm_kms_helper_hotplug_event(dev); 2696 } 2697 2698 static bool drm_dp_validate_guid(struct drm_dp_mst_topology_mgr *mgr, 2699 guid_t *guid) 2700 { 2701 if (!guid_is_null(guid)) 2702 return true; 2703 2704 guid_gen(guid); 2705 2706 return false; 2707 } 2708 2709 static void build_dpcd_read(struct drm_dp_sideband_msg_tx *msg, 2710 u8 port_num, u32 offset, u8 num_bytes) 2711 { 2712 struct drm_dp_sideband_msg_req_body req; 2713 2714 req.req_type = DP_REMOTE_DPCD_READ; 2715 req.u.dpcd_read.port_number = port_num; 2716 req.u.dpcd_read.dpcd_address = offset; 2717 req.u.dpcd_read.num_bytes = num_bytes; 2718 drm_dp_encode_sideband_req(&req, msg); 2719 } 2720 2721 static int drm_dp_send_sideband_msg(struct drm_dp_mst_topology_mgr *mgr, 2722 bool up, u8 *msg, int len) 2723 { 2724 int ret; 2725 int regbase = up ? DP_SIDEBAND_MSG_UP_REP_BASE : DP_SIDEBAND_MSG_DOWN_REQ_BASE; 2726 int tosend, total, offset; 2727 int retries = 0; 2728 2729 retry: 2730 total = len; 2731 offset = 0; 2732 do { 2733 tosend = min3(mgr->max_dpcd_transaction_bytes, 16, total); 2734 2735 ret = drm_dp_dpcd_write(mgr->aux, regbase + offset, 2736 &msg[offset], 2737 tosend); 2738 if (ret != tosend) { 2739 if (ret == -EIO && retries < 5) { 2740 retries++; 2741 goto retry; 2742 } 2743 drm_dbg_kms(mgr->dev, "failed to dpcd write %d %d\n", tosend, ret); 2744 2745 return -EIO; 2746 } 2747 offset += tosend; 2748 total -= tosend; 2749 } while (total > 0); 2750 return 0; 2751 } 2752 2753 static int set_hdr_from_dst_qlock(struct drm_dp_sideband_msg_hdr *hdr, 2754 struct drm_dp_sideband_msg_tx *txmsg) 2755 { 2756 struct drm_dp_mst_branch *mstb = txmsg->dst; 2757 u8 req_type; 2758 2759 req_type = txmsg->msg[0] & 0x7f; 2760 if (req_type == DP_CONNECTION_STATUS_NOTIFY || 2761 req_type == DP_RESOURCE_STATUS_NOTIFY || 2762 req_type == DP_CLEAR_PAYLOAD_ID_TABLE) 2763 hdr->broadcast = 1; 2764 else 2765 hdr->broadcast = 0; 2766 hdr->path_msg = txmsg->path_msg; 2767 if (hdr->broadcast) { 2768 hdr->lct = 1; 2769 hdr->lcr = 6; 2770 } else { 2771 hdr->lct = mstb->lct; 2772 hdr->lcr = mstb->lct - 1; 2773 } 2774 2775 memcpy(hdr->rad, mstb->rad, hdr->lct / 2); 2776 2777 return 0; 2778 } 2779 /* 2780 * process a single block of the next message in the sideband queue 2781 */ 2782 static int process_single_tx_qlock(struct drm_dp_mst_topology_mgr *mgr, 2783 struct drm_dp_sideband_msg_tx *txmsg, 2784 bool up) 2785 { 2786 u8 chunk[48]; 2787 struct drm_dp_sideband_msg_hdr hdr; 2788 int len, space, idx, tosend; 2789 int ret; 2790 2791 if (txmsg->state == DRM_DP_SIDEBAND_TX_SENT) 2792 return 0; 2793 2794 memset(&hdr, 0, sizeof(struct drm_dp_sideband_msg_hdr)); 2795 2796 if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED) 2797 txmsg->state = DRM_DP_SIDEBAND_TX_START_SEND; 2798 2799 /* make hdr from dst mst */ 2800 ret = set_hdr_from_dst_qlock(&hdr, txmsg); 2801 if (ret < 0) 2802 return ret; 2803 2804 /* amount left to send in this message */ 2805 len = txmsg->cur_len - txmsg->cur_offset; 2806 2807 /* 48 - sideband msg size - 1 byte for data CRC, x header bytes */ 2808 space = 48 - 1 - drm_dp_calc_sb_hdr_size(&hdr); 2809 2810 tosend = min(len, space); 2811 if (len == txmsg->cur_len) 2812 hdr.somt = 1; 2813 if (space >= len) 2814 hdr.eomt = 1; 2815 2816 2817 hdr.msg_len = tosend + 1; 2818 drm_dp_encode_sideband_msg_hdr(&hdr, chunk, &idx); 2819 memcpy(&chunk[idx], &txmsg->msg[txmsg->cur_offset], tosend); 2820 /* add crc at end */ 2821 drm_dp_crc_sideband_chunk_req(&chunk[idx], tosend); 2822 idx += tosend + 1; 2823 2824 ret = drm_dp_send_sideband_msg(mgr, up, chunk, idx); 2825 if (ret) { 2826 if (drm_debug_enabled(DRM_UT_DP)) { 2827 struct drm_printer p = drm_dbg_printer(mgr->dev, 2828 DRM_UT_DP, 2829 DBG_PREFIX); 2830 2831 drm_printf(&p, "sideband msg failed to send\n"); 2832 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 2833 } 2834 return ret; 2835 } 2836 2837 txmsg->cur_offset += tosend; 2838 if (txmsg->cur_offset == txmsg->cur_len) { 2839 txmsg->state = DRM_DP_SIDEBAND_TX_SENT; 2840 return 1; 2841 } 2842 return 0; 2843 } 2844 2845 static void process_single_down_tx_qlock(struct drm_dp_mst_topology_mgr *mgr) 2846 { 2847 struct drm_dp_sideband_msg_tx *txmsg; 2848 int ret; 2849 2850 WARN_ON(!mutex_is_locked(&mgr->qlock)); 2851 2852 /* construct a chunk from the first msg in the tx_msg queue */ 2853 if (list_empty(&mgr->tx_msg_downq)) 2854 return; 2855 2856 txmsg = list_first_entry(&mgr->tx_msg_downq, 2857 struct drm_dp_sideband_msg_tx, next); 2858 ret = process_single_tx_qlock(mgr, txmsg, false); 2859 if (ret < 0) { 2860 drm_dbg_kms(mgr->dev, "failed to send msg in q %d\n", ret); 2861 list_del(&txmsg->next); 2862 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 2863 wake_up_all(&mgr->tx_waitq); 2864 } 2865 } 2866 2867 static void drm_dp_queue_down_tx(struct drm_dp_mst_topology_mgr *mgr, 2868 struct drm_dp_sideband_msg_tx *txmsg) 2869 { 2870 mutex_lock(&mgr->qlock); 2871 list_add_tail(&txmsg->next, &mgr->tx_msg_downq); 2872 2873 if (drm_debug_enabled(DRM_UT_DP)) { 2874 struct drm_printer p = drm_dbg_printer(mgr->dev, DRM_UT_DP, 2875 DBG_PREFIX); 2876 2877 drm_dp_mst_dump_sideband_msg_tx(&p, txmsg); 2878 } 2879 2880 if (list_is_singular(&mgr->tx_msg_downq)) 2881 process_single_down_tx_qlock(mgr); 2882 mutex_unlock(&mgr->qlock); 2883 } 2884 2885 static void 2886 drm_dp_dump_link_address(const struct drm_dp_mst_topology_mgr *mgr, 2887 struct drm_dp_link_address_ack_reply *reply) 2888 { 2889 struct drm_dp_link_addr_reply_port *port_reply; 2890 int i; 2891 2892 for (i = 0; i < reply->nports; i++) { 2893 port_reply = &reply->ports[i]; 2894 drm_dbg_kms(mgr->dev, 2895 "port %d: input %d, pdt: %d, pn: %d, dpcd_rev: %02x, mcs: %d, ddps: %d, ldps %d, sdp %d/%d\n", 2896 i, 2897 port_reply->input_port, 2898 port_reply->peer_device_type, 2899 port_reply->port_number, 2900 port_reply->dpcd_revision, 2901 port_reply->mcs, 2902 port_reply->ddps, 2903 port_reply->legacy_device_plug_status, 2904 port_reply->num_sdp_streams, 2905 port_reply->num_sdp_stream_sinks); 2906 } 2907 } 2908 2909 static int drm_dp_send_link_address(struct drm_dp_mst_topology_mgr *mgr, 2910 struct drm_dp_mst_branch *mstb) 2911 { 2912 struct drm_dp_sideband_msg_tx *txmsg; 2913 struct drm_dp_link_address_ack_reply *reply; 2914 struct drm_dp_mst_port *port, *tmp; 2915 int i, ret, port_mask = 0; 2916 bool changed = false; 2917 2918 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 2919 if (!txmsg) 2920 return -ENOMEM; 2921 2922 txmsg->dst = mstb; 2923 build_link_address(txmsg); 2924 2925 mstb->link_address_sent = true; 2926 drm_dp_queue_down_tx(mgr, txmsg); 2927 2928 /* FIXME: Actually do some real error handling here */ 2929 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 2930 if (ret < 0) { 2931 drm_err(mgr->dev, "Sending link address failed with %d\n", ret); 2932 goto out; 2933 } 2934 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 2935 drm_err(mgr->dev, "link address NAK received\n"); 2936 ret = -EIO; 2937 goto out; 2938 } 2939 2940 reply = &txmsg->reply.u.link_addr; 2941 drm_dbg_kms(mgr->dev, "link address reply: %d\n", reply->nports); 2942 drm_dp_dump_link_address(mgr, reply); 2943 2944 ret = drm_dp_check_mstb_guid(mstb, &reply->guid); 2945 if (ret) { 2946 char buf[64]; 2947 2948 drm_dp_mst_rad_to_str(mstb->rad, mstb->lct, buf, sizeof(buf)); 2949 drm_err(mgr->dev, "GUID check on %s failed: %d\n", buf, ret); 2950 goto out; 2951 } 2952 2953 for (i = 0; i < reply->nports; i++) { 2954 port_mask |= BIT(reply->ports[i].port_number); 2955 ret = drm_dp_mst_handle_link_address_port(mstb, mgr->dev, 2956 &reply->ports[i]); 2957 if (ret == 1) 2958 changed = true; 2959 else if (ret < 0) 2960 goto out; 2961 } 2962 2963 /* Prune any ports that are currently a part of mstb in our in-memory 2964 * topology, but were not seen in this link address. Usually this 2965 * means that they were removed while the topology was out of sync, 2966 * e.g. during suspend/resume 2967 */ 2968 mutex_lock(&mgr->lock); 2969 list_for_each_entry_safe(port, tmp, &mstb->ports, next) { 2970 if (port_mask & BIT(port->port_num)) 2971 continue; 2972 2973 drm_dbg_kms(mgr->dev, "port %d was not in link address, removing\n", 2974 port->port_num); 2975 list_del(&port->next); 2976 drm_dp_mst_topology_put_port(port); 2977 changed = true; 2978 } 2979 mutex_unlock(&mgr->lock); 2980 2981 out: 2982 if (ret < 0) 2983 mstb->link_address_sent = false; 2984 kfree(txmsg); 2985 return ret < 0 ? ret : changed; 2986 } 2987 2988 static void 2989 drm_dp_send_clear_payload_id_table(struct drm_dp_mst_topology_mgr *mgr, 2990 struct drm_dp_mst_branch *mstb) 2991 { 2992 struct drm_dp_sideband_msg_tx *txmsg; 2993 int ret; 2994 2995 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 2996 if (!txmsg) 2997 return; 2998 2999 txmsg->dst = mstb; 3000 build_clear_payload_id_table(txmsg); 3001 3002 drm_dp_queue_down_tx(mgr, txmsg); 3003 3004 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3005 if (ret > 0 && txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3006 drm_dbg_kms(mgr->dev, "clear payload table id nak received\n"); 3007 3008 kfree(txmsg); 3009 } 3010 3011 static int 3012 drm_dp_send_enum_path_resources(struct drm_dp_mst_topology_mgr *mgr, 3013 struct drm_dp_mst_branch *mstb, 3014 struct drm_dp_mst_port *port) 3015 { 3016 struct drm_dp_enum_path_resources_ack_reply *path_res; 3017 struct drm_dp_sideband_msg_tx *txmsg; 3018 int ret; 3019 3020 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3021 if (!txmsg) 3022 return -ENOMEM; 3023 3024 txmsg->dst = mstb; 3025 build_enum_path_resources(txmsg, port->port_num); 3026 3027 drm_dp_queue_down_tx(mgr, txmsg); 3028 3029 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3030 if (ret > 0) { 3031 ret = 0; 3032 path_res = &txmsg->reply.u.path_resources; 3033 3034 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3035 drm_dbg_kms(mgr->dev, "enum path resources nak received\n"); 3036 } else { 3037 if (port->port_num != path_res->port_number) 3038 DRM_ERROR("got incorrect port in response\n"); 3039 3040 drm_dbg_kms(mgr->dev, "enum path resources %d: %d %d\n", 3041 path_res->port_number, 3042 path_res->full_payload_bw_number, 3043 path_res->avail_payload_bw_number); 3044 3045 /* 3046 * If something changed, make sure we send a 3047 * hotplug 3048 */ 3049 if (port->full_pbn != path_res->full_payload_bw_number || 3050 port->fec_capable != path_res->fec_capable) 3051 ret = 1; 3052 3053 port->full_pbn = path_res->full_payload_bw_number; 3054 port->fec_capable = path_res->fec_capable; 3055 } 3056 } 3057 3058 kfree(txmsg); 3059 return ret; 3060 } 3061 3062 static struct drm_dp_mst_port *drm_dp_get_last_connected_port_to_mstb(struct drm_dp_mst_branch *mstb) 3063 { 3064 if (!mstb->port_parent) 3065 return NULL; 3066 3067 if (mstb->port_parent->mstb != mstb) 3068 return mstb->port_parent; 3069 3070 return drm_dp_get_last_connected_port_to_mstb(mstb->port_parent->parent); 3071 } 3072 3073 /* 3074 * Searches upwards in the topology starting from mstb to try to find the 3075 * closest available parent of mstb that's still connected to the rest of the 3076 * topology. This can be used in order to perform operations like releasing 3077 * payloads, where the branch device which owned the payload may no longer be 3078 * around and thus would require that the payload on the last living relative 3079 * be freed instead. 3080 */ 3081 static struct drm_dp_mst_branch * 3082 drm_dp_get_last_connected_port_and_mstb(struct drm_dp_mst_topology_mgr *mgr, 3083 struct drm_dp_mst_branch *mstb, 3084 int *port_num) 3085 { 3086 struct drm_dp_mst_branch *rmstb = NULL; 3087 struct drm_dp_mst_port *found_port; 3088 3089 mutex_lock(&mgr->lock); 3090 if (!mgr->mst_primary) 3091 goto out; 3092 3093 do { 3094 found_port = drm_dp_get_last_connected_port_to_mstb(mstb); 3095 if (!found_port) 3096 break; 3097 3098 if (drm_dp_mst_topology_try_get_mstb(found_port->parent)) { 3099 rmstb = found_port->parent; 3100 *port_num = found_port->port_num; 3101 } else { 3102 /* Search again, starting from this parent */ 3103 mstb = found_port->parent; 3104 } 3105 } while (!rmstb); 3106 out: 3107 mutex_unlock(&mgr->lock); 3108 return rmstb; 3109 } 3110 3111 static int drm_dp_payload_send_msg(struct drm_dp_mst_topology_mgr *mgr, 3112 struct drm_dp_mst_port *port, 3113 int id, 3114 int pbn) 3115 { 3116 struct drm_dp_sideband_msg_tx *txmsg; 3117 struct drm_dp_mst_branch *mstb; 3118 int ret, port_num; 3119 u8 sinks[DRM_DP_MAX_SDP_STREAMS]; 3120 int i; 3121 3122 port_num = port->port_num; 3123 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 3124 if (!mstb) { 3125 mstb = drm_dp_get_last_connected_port_and_mstb(mgr, 3126 port->parent, 3127 &port_num); 3128 3129 if (!mstb) 3130 return -EINVAL; 3131 } 3132 3133 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3134 if (!txmsg) { 3135 ret = -ENOMEM; 3136 goto fail_put; 3137 } 3138 3139 for (i = 0; i < port->num_sdp_streams; i++) 3140 sinks[i] = i; 3141 3142 txmsg->dst = mstb; 3143 build_allocate_payload(txmsg, port_num, 3144 id, 3145 pbn, port->num_sdp_streams, sinks); 3146 3147 drm_dp_queue_down_tx(mgr, txmsg); 3148 3149 /* 3150 * FIXME: there is a small chance that between getting the last 3151 * connected mstb and sending the payload message, the last connected 3152 * mstb could also be removed from the topology. In the future, this 3153 * needs to be fixed by restarting the 3154 * drm_dp_get_last_connected_port_and_mstb() search in the event of a 3155 * timeout if the topology is still connected to the system. 3156 */ 3157 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3158 if (ret > 0) { 3159 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3160 ret = -EINVAL; 3161 else 3162 ret = 0; 3163 } 3164 kfree(txmsg); 3165 fail_put: 3166 drm_dp_mst_topology_put_mstb(mstb); 3167 return ret; 3168 } 3169 3170 int drm_dp_send_power_updown_phy(struct drm_dp_mst_topology_mgr *mgr, 3171 struct drm_dp_mst_port *port, bool power_up) 3172 { 3173 struct drm_dp_sideband_msg_tx *txmsg; 3174 int ret; 3175 3176 port = drm_dp_mst_topology_get_port_validated(mgr, port); 3177 if (!port) 3178 return -EINVAL; 3179 3180 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3181 if (!txmsg) { 3182 drm_dp_mst_topology_put_port(port); 3183 return -ENOMEM; 3184 } 3185 3186 txmsg->dst = port->parent; 3187 build_power_updown_phy(txmsg, port->port_num, power_up); 3188 drm_dp_queue_down_tx(mgr, txmsg); 3189 3190 ret = drm_dp_mst_wait_tx_reply(port->parent, txmsg); 3191 if (ret > 0) { 3192 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3193 ret = -EINVAL; 3194 else 3195 ret = 0; 3196 } 3197 kfree(txmsg); 3198 drm_dp_mst_topology_put_port(port); 3199 3200 return ret; 3201 } 3202 EXPORT_SYMBOL(drm_dp_send_power_updown_phy); 3203 3204 int drm_dp_send_query_stream_enc_status(struct drm_dp_mst_topology_mgr *mgr, 3205 struct drm_dp_mst_port *port, 3206 struct drm_dp_query_stream_enc_status_ack_reply *status) 3207 { 3208 struct drm_dp_mst_topology_state *state; 3209 struct drm_dp_mst_atomic_payload *payload; 3210 struct drm_dp_sideband_msg_tx *txmsg; 3211 u8 nonce[7]; 3212 int ret; 3213 3214 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3215 if (!txmsg) 3216 return -ENOMEM; 3217 3218 port = drm_dp_mst_topology_get_port_validated(mgr, port); 3219 if (!port) { 3220 ret = -EINVAL; 3221 goto out_get_port; 3222 } 3223 3224 get_random_bytes(nonce, sizeof(nonce)); 3225 3226 drm_modeset_lock(&mgr->base.lock, NULL); 3227 state = to_drm_dp_mst_topology_state(mgr->base.state); 3228 payload = drm_atomic_get_mst_payload_state(state, port); 3229 3230 /* 3231 * "Source device targets the QUERY_STREAM_ENCRYPTION_STATUS message 3232 * transaction at the MST Branch device directly connected to the 3233 * Source" 3234 */ 3235 txmsg->dst = mgr->mst_primary; 3236 3237 build_query_stream_enc_status(txmsg, payload->vcpi, nonce); 3238 3239 drm_dp_queue_down_tx(mgr, txmsg); 3240 3241 ret = drm_dp_mst_wait_tx_reply(mgr->mst_primary, txmsg); 3242 if (ret < 0) { 3243 goto out; 3244 } else if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3245 drm_dbg_kms(mgr->dev, "query encryption status nak received\n"); 3246 ret = -ENXIO; 3247 goto out; 3248 } 3249 3250 ret = 0; 3251 memcpy(status, &txmsg->reply.u.enc_status, sizeof(*status)); 3252 3253 out: 3254 drm_modeset_unlock(&mgr->base.lock); 3255 drm_dp_mst_topology_put_port(port); 3256 out_get_port: 3257 kfree(txmsg); 3258 return ret; 3259 } 3260 EXPORT_SYMBOL(drm_dp_send_query_stream_enc_status); 3261 3262 static int drm_dp_create_payload_at_dfp(struct drm_dp_mst_topology_mgr *mgr, 3263 struct drm_dp_mst_atomic_payload *payload) 3264 { 3265 return drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot, 3266 payload->time_slots); 3267 } 3268 3269 static int drm_dp_create_payload_to_remote(struct drm_dp_mst_topology_mgr *mgr, 3270 struct drm_dp_mst_atomic_payload *payload) 3271 { 3272 int ret; 3273 struct drm_dp_mst_port *port = drm_dp_mst_topology_get_port_validated(mgr, payload->port); 3274 3275 if (!port) 3276 return -EIO; 3277 3278 ret = drm_dp_payload_send_msg(mgr, port, payload->vcpi, payload->pbn); 3279 drm_dp_mst_topology_put_port(port); 3280 return ret; 3281 } 3282 3283 static void drm_dp_destroy_payload_at_remote_and_dfp(struct drm_dp_mst_topology_mgr *mgr, 3284 struct drm_dp_mst_topology_state *mst_state, 3285 struct drm_dp_mst_atomic_payload *payload) 3286 { 3287 drm_dbg_kms(mgr->dev, "\n"); 3288 3289 /* it's okay for these to fail */ 3290 if (payload->payload_allocation_status == DRM_DP_MST_PAYLOAD_ALLOCATION_REMOTE) { 3291 drm_dp_payload_send_msg(mgr, payload->port, payload->vcpi, 0); 3292 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_DFP; 3293 } 3294 3295 if (payload->payload_allocation_status == DRM_DP_MST_PAYLOAD_ALLOCATION_DFP) 3296 drm_dp_dpcd_write_payload(mgr, payload->vcpi, payload->vc_start_slot, 0); 3297 } 3298 3299 /** 3300 * drm_dp_add_payload_part1() - Execute payload update part 1 3301 * @mgr: Manager to use. 3302 * @mst_state: The MST atomic state 3303 * @payload: The payload to write 3304 * 3305 * Determines the starting time slot for the given payload, and programs the VCPI for this payload 3306 * into the DPCD of DPRX. After calling this, the driver should generate ACT and payload packets. 3307 * 3308 * Returns: 0 on success, error code on failure. 3309 */ 3310 int drm_dp_add_payload_part1(struct drm_dp_mst_topology_mgr *mgr, 3311 struct drm_dp_mst_topology_state *mst_state, 3312 struct drm_dp_mst_atomic_payload *payload) 3313 { 3314 struct drm_dp_mst_port *port; 3315 int ret; 3316 3317 /* Update mst mgr info */ 3318 if (mgr->payload_count == 0) 3319 mgr->next_start_slot = mst_state->start_slot; 3320 3321 payload->vc_start_slot = mgr->next_start_slot; 3322 3323 mgr->payload_count++; 3324 mgr->next_start_slot += payload->time_slots; 3325 3326 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_LOCAL; 3327 3328 /* Allocate payload to immediate downstream facing port */ 3329 port = drm_dp_mst_topology_get_port_validated(mgr, payload->port); 3330 if (!port) { 3331 drm_dbg_kms(mgr->dev, 3332 "VCPI %d for port %p not in topology, not creating a payload to remote\n", 3333 payload->vcpi, payload->port); 3334 return -EIO; 3335 } 3336 3337 ret = drm_dp_create_payload_at_dfp(mgr, payload); 3338 if (ret < 0) { 3339 drm_dbg_kms(mgr->dev, "Failed to create MST payload for port %p: %d\n", 3340 payload->port, ret); 3341 goto put_port; 3342 } 3343 3344 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_DFP; 3345 3346 put_port: 3347 drm_dp_mst_topology_put_port(port); 3348 3349 return ret; 3350 } 3351 EXPORT_SYMBOL(drm_dp_add_payload_part1); 3352 3353 /** 3354 * drm_dp_remove_payload_part1() - Remove an MST payload along the virtual channel 3355 * @mgr: Manager to use. 3356 * @mst_state: The MST atomic state 3357 * @payload: The payload to remove 3358 * 3359 * Removes a payload along the virtual channel if it was successfully allocated. 3360 * After calling this, the driver should set HW to generate ACT and then switch to new 3361 * payload allocation state. 3362 */ 3363 void drm_dp_remove_payload_part1(struct drm_dp_mst_topology_mgr *mgr, 3364 struct drm_dp_mst_topology_state *mst_state, 3365 struct drm_dp_mst_atomic_payload *payload) 3366 { 3367 /* Remove remote payload allocation */ 3368 bool send_remove = false; 3369 3370 mutex_lock(&mgr->lock); 3371 send_remove = drm_dp_mst_port_downstream_of_branch(payload->port, mgr->mst_primary); 3372 mutex_unlock(&mgr->lock); 3373 3374 if (send_remove) 3375 drm_dp_destroy_payload_at_remote_and_dfp(mgr, mst_state, payload); 3376 else 3377 drm_dbg_kms(mgr->dev, "Payload for VCPI %d not in topology, not sending remove\n", 3378 payload->vcpi); 3379 3380 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_LOCAL; 3381 } 3382 EXPORT_SYMBOL(drm_dp_remove_payload_part1); 3383 3384 /** 3385 * drm_dp_remove_payload_part2() - Remove an MST payload locally 3386 * @mgr: Manager to use. 3387 * @mst_state: The MST atomic state 3388 * @old_payload: The payload with its old state 3389 * @new_payload: The payload with its latest state 3390 * 3391 * Updates the starting time slots of all other payloads which would have been shifted towards 3392 * the start of the payload ID table as a result of removing a payload. Driver should call this 3393 * function whenever it removes a payload in its HW. It's independent to the result of payload 3394 * allocation/deallocation at branch devices along the virtual channel. 3395 */ 3396 void drm_dp_remove_payload_part2(struct drm_dp_mst_topology_mgr *mgr, 3397 struct drm_dp_mst_topology_state *mst_state, 3398 const struct drm_dp_mst_atomic_payload *old_payload, 3399 struct drm_dp_mst_atomic_payload *new_payload) 3400 { 3401 struct drm_dp_mst_atomic_payload *pos; 3402 3403 /* Remove local payload allocation */ 3404 list_for_each_entry(pos, &mst_state->payloads, next) { 3405 if (pos != new_payload && pos->vc_start_slot > new_payload->vc_start_slot) 3406 pos->vc_start_slot -= old_payload->time_slots; 3407 } 3408 new_payload->vc_start_slot = -1; 3409 3410 mgr->payload_count--; 3411 mgr->next_start_slot -= old_payload->time_slots; 3412 3413 if (new_payload->delete) 3414 drm_dp_mst_put_port_malloc(new_payload->port); 3415 3416 new_payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_NONE; 3417 } 3418 EXPORT_SYMBOL(drm_dp_remove_payload_part2); 3419 /** 3420 * drm_dp_add_payload_part2() - Execute payload update part 2 3421 * @mgr: Manager to use. 3422 * @payload: The payload to update 3423 * 3424 * If @payload was successfully assigned a starting time slot by drm_dp_add_payload_part1(), this 3425 * function will send the sideband messages to finish allocating this payload. 3426 * 3427 * Returns: 0 on success, negative error code on failure. 3428 */ 3429 int drm_dp_add_payload_part2(struct drm_dp_mst_topology_mgr *mgr, 3430 struct drm_dp_mst_atomic_payload *payload) 3431 { 3432 int ret = 0; 3433 3434 /* Skip failed payloads */ 3435 if (payload->payload_allocation_status != DRM_DP_MST_PAYLOAD_ALLOCATION_DFP) { 3436 drm_dbg_kms(mgr->dev, "Part 1 of payload creation for %s failed, skipping part 2\n", 3437 payload->port->connector->name); 3438 return -EIO; 3439 } 3440 3441 /* Allocate payload to remote end */ 3442 ret = drm_dp_create_payload_to_remote(mgr, payload); 3443 if (ret < 0) 3444 drm_err(mgr->dev, "Step 2 of creating MST payload for %p failed: %d\n", 3445 payload->port, ret); 3446 else 3447 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_REMOTE; 3448 3449 return ret; 3450 } 3451 EXPORT_SYMBOL(drm_dp_add_payload_part2); 3452 3453 static int drm_dp_send_dpcd_read(struct drm_dp_mst_topology_mgr *mgr, 3454 struct drm_dp_mst_port *port, 3455 int offset, int size, u8 *bytes) 3456 { 3457 int ret = 0; 3458 struct drm_dp_sideband_msg_tx *txmsg; 3459 struct drm_dp_mst_branch *mstb; 3460 3461 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 3462 if (!mstb) 3463 return -EINVAL; 3464 3465 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3466 if (!txmsg) { 3467 ret = -ENOMEM; 3468 goto fail_put; 3469 } 3470 3471 build_dpcd_read(txmsg, port->port_num, offset, size); 3472 txmsg->dst = port->parent; 3473 3474 drm_dp_queue_down_tx(mgr, txmsg); 3475 3476 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3477 if (ret < 0) 3478 goto fail_free; 3479 3480 if (txmsg->reply.reply_type == 1) { 3481 drm_dbg_kms(mgr->dev, "mstb %p port %d: DPCD read on addr 0x%x for %d bytes NAKed\n", 3482 mstb, port->port_num, offset, size); 3483 ret = -EIO; 3484 goto fail_free; 3485 } 3486 3487 if (txmsg->reply.u.remote_dpcd_read_ack.num_bytes != size) { 3488 ret = -EPROTO; 3489 goto fail_free; 3490 } 3491 3492 ret = min_t(size_t, txmsg->reply.u.remote_dpcd_read_ack.num_bytes, 3493 size); 3494 memcpy(bytes, txmsg->reply.u.remote_dpcd_read_ack.bytes, ret); 3495 3496 fail_free: 3497 kfree(txmsg); 3498 fail_put: 3499 drm_dp_mst_topology_put_mstb(mstb); 3500 3501 return ret; 3502 } 3503 3504 static int drm_dp_send_dpcd_write(struct drm_dp_mst_topology_mgr *mgr, 3505 struct drm_dp_mst_port *port, 3506 int offset, int size, u8 *bytes) 3507 { 3508 int ret; 3509 struct drm_dp_sideband_msg_tx *txmsg; 3510 struct drm_dp_mst_branch *mstb; 3511 3512 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 3513 if (!mstb) 3514 return -EINVAL; 3515 3516 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3517 if (!txmsg) { 3518 ret = -ENOMEM; 3519 goto fail_put; 3520 } 3521 3522 build_dpcd_write(txmsg, port->port_num, offset, size, bytes); 3523 txmsg->dst = mstb; 3524 3525 drm_dp_queue_down_tx(mgr, txmsg); 3526 3527 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 3528 if (ret > 0) { 3529 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) 3530 ret = -EIO; 3531 else 3532 ret = size; 3533 } 3534 3535 kfree(txmsg); 3536 fail_put: 3537 drm_dp_mst_topology_put_mstb(mstb); 3538 return ret; 3539 } 3540 3541 static int drm_dp_encode_up_ack_reply(struct drm_dp_sideband_msg_tx *msg, u8 req_type) 3542 { 3543 struct drm_dp_sideband_msg_reply_body reply; 3544 3545 reply.reply_type = DP_SIDEBAND_REPLY_ACK; 3546 reply.req_type = req_type; 3547 drm_dp_encode_sideband_reply(&reply, msg); 3548 return 0; 3549 } 3550 3551 static int drm_dp_send_up_ack_reply(struct drm_dp_mst_topology_mgr *mgr, 3552 struct drm_dp_mst_branch *mstb, 3553 int req_type, bool broadcast) 3554 { 3555 struct drm_dp_sideband_msg_tx *txmsg; 3556 3557 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 3558 if (!txmsg) 3559 return -ENOMEM; 3560 3561 txmsg->dst = mstb; 3562 drm_dp_encode_up_ack_reply(txmsg, req_type); 3563 3564 mutex_lock(&mgr->qlock); 3565 /* construct a chunk from the first msg in the tx_msg queue */ 3566 process_single_tx_qlock(mgr, txmsg, true); 3567 mutex_unlock(&mgr->qlock); 3568 3569 kfree(txmsg); 3570 return 0; 3571 } 3572 3573 /** 3574 * drm_dp_get_vc_payload_bw - get the VC payload BW for an MST link 3575 * @mgr: The &drm_dp_mst_topology_mgr to use 3576 * @link_rate: link rate in 10kbits/s units 3577 * @link_lane_count: lane count 3578 * 3579 * Calculate the total bandwidth of a MultiStream Transport link. The returned 3580 * value is in units of PBNs/(timeslots/1 MTP). This value can be used to 3581 * convert the number of PBNs required for a given stream to the number of 3582 * timeslots this stream requires in each MTP. 3583 * 3584 * Returns the BW / timeslot value in 20.12 fixed point format. 3585 */ 3586 fixed20_12 drm_dp_get_vc_payload_bw(const struct drm_dp_mst_topology_mgr *mgr, 3587 int link_rate, int link_lane_count) 3588 { 3589 int ch_coding_efficiency = 3590 drm_dp_bw_channel_coding_efficiency(drm_dp_is_uhbr_rate(link_rate)); 3591 fixed20_12 ret; 3592 3593 if (link_rate == 0 || link_lane_count == 0) 3594 drm_dbg_kms(mgr->dev, "invalid link rate/lane count: (%d / %d)\n", 3595 link_rate, link_lane_count); 3596 3597 /* See DP v2.0 2.6.4.2, 2.7.6.3 VCPayload_Bandwidth_for_OneTimeSlotPer_MTP_Allocation */ 3598 ret.full = DIV_ROUND_DOWN_ULL(mul_u32_u32(link_rate * link_lane_count, 3599 ch_coding_efficiency), 3600 (1000000ULL * 8 * 5400) >> 12); 3601 3602 return ret; 3603 } 3604 EXPORT_SYMBOL(drm_dp_get_vc_payload_bw); 3605 3606 /** 3607 * drm_dp_read_mst_cap() - Read the sink's MST mode capability 3608 * @aux: The DP AUX channel to use 3609 * @dpcd: A cached copy of the DPCD capabilities for this sink 3610 * 3611 * Returns: enum drm_dp_mst_mode to indicate MST mode capability 3612 */ 3613 enum drm_dp_mst_mode drm_dp_read_mst_cap(struct drm_dp_aux *aux, 3614 const u8 dpcd[DP_RECEIVER_CAP_SIZE]) 3615 { 3616 u8 mstm_cap; 3617 3618 if (dpcd[DP_DPCD_REV] < DP_DPCD_REV_12) 3619 return DRM_DP_SST; 3620 3621 if (drm_dp_dpcd_readb(aux, DP_MSTM_CAP, &mstm_cap) != 1) 3622 return DRM_DP_SST; 3623 3624 if (mstm_cap & DP_MST_CAP) 3625 return DRM_DP_MST; 3626 3627 if (mstm_cap & DP_SINGLE_STREAM_SIDEBAND_MSG) 3628 return DRM_DP_SST_SIDEBAND_MSG; 3629 3630 return DRM_DP_SST; 3631 } 3632 EXPORT_SYMBOL(drm_dp_read_mst_cap); 3633 3634 /** 3635 * drm_dp_mst_topology_mgr_set_mst() - Set the MST state for a topology manager 3636 * @mgr: manager to set state for 3637 * @mst_state: true to enable MST on this connector - false to disable. 3638 * 3639 * This is called by the driver when it detects an MST capable device plugged 3640 * into a DP MST capable port, or when a DP MST capable device is unplugged. 3641 */ 3642 int drm_dp_mst_topology_mgr_set_mst(struct drm_dp_mst_topology_mgr *mgr, bool mst_state) 3643 { 3644 int ret = 0; 3645 struct drm_dp_mst_branch *mstb = NULL; 3646 3647 mutex_lock(&mgr->lock); 3648 if (mst_state == mgr->mst_state) 3649 goto out_unlock; 3650 3651 mgr->mst_state = mst_state; 3652 /* set the device into MST mode */ 3653 if (mst_state) { 3654 WARN_ON(mgr->mst_primary); 3655 3656 /* get dpcd info */ 3657 ret = drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd); 3658 if (ret < 0) { 3659 drm_dbg_kms(mgr->dev, "%s: failed to read DPCD, ret %d\n", 3660 mgr->aux->name, ret); 3661 goto out_unlock; 3662 } 3663 3664 /* add initial branch device at LCT 1 */ 3665 mstb = drm_dp_add_mst_branch_device(1, NULL); 3666 if (mstb == NULL) { 3667 ret = -ENOMEM; 3668 goto out_unlock; 3669 } 3670 mstb->mgr = mgr; 3671 3672 /* give this the main reference */ 3673 mgr->mst_primary = mstb; 3674 drm_dp_mst_topology_get_mstb(mgr->mst_primary); 3675 3676 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 3677 DP_MST_EN | 3678 DP_UP_REQ_EN | 3679 DP_UPSTREAM_IS_SRC); 3680 if (ret < 0) 3681 goto out_unlock; 3682 3683 /* Write reset payload */ 3684 drm_dp_dpcd_write_payload(mgr, 0, 0, 0x3f); 3685 3686 queue_work(system_long_wq, &mgr->work); 3687 3688 ret = 0; 3689 } else { 3690 /* disable MST on the device */ 3691 mstb = mgr->mst_primary; 3692 mgr->mst_primary = NULL; 3693 /* this can fail if the device is gone */ 3694 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 0); 3695 ret = 0; 3696 mgr->payload_id_table_cleared = false; 3697 3698 memset(&mgr->down_rep_recv, 0, sizeof(mgr->down_rep_recv)); 3699 memset(&mgr->up_req_recv, 0, sizeof(mgr->up_req_recv)); 3700 } 3701 3702 out_unlock: 3703 mutex_unlock(&mgr->lock); 3704 if (mstb) 3705 drm_dp_mst_topology_put_mstb(mstb); 3706 return ret; 3707 3708 } 3709 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_set_mst); 3710 3711 static void 3712 drm_dp_mst_topology_mgr_invalidate_mstb(struct drm_dp_mst_branch *mstb) 3713 { 3714 struct drm_dp_mst_port *port; 3715 3716 /* The link address will need to be re-sent on resume */ 3717 mstb->link_address_sent = false; 3718 3719 list_for_each_entry(port, &mstb->ports, next) 3720 if (port->mstb) 3721 drm_dp_mst_topology_mgr_invalidate_mstb(port->mstb); 3722 } 3723 3724 /** 3725 * drm_dp_mst_topology_mgr_suspend() - suspend the MST manager 3726 * @mgr: manager to suspend 3727 * 3728 * This function tells the MST device that we can't handle UP messages 3729 * anymore. This should stop it from sending any since we are suspended. 3730 */ 3731 void drm_dp_mst_topology_mgr_suspend(struct drm_dp_mst_topology_mgr *mgr) 3732 { 3733 mutex_lock(&mgr->lock); 3734 drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 3735 DP_MST_EN | DP_UPSTREAM_IS_SRC); 3736 mutex_unlock(&mgr->lock); 3737 flush_work(&mgr->up_req_work); 3738 flush_work(&mgr->work); 3739 flush_work(&mgr->delayed_destroy_work); 3740 3741 mutex_lock(&mgr->lock); 3742 if (mgr->mst_state && mgr->mst_primary) 3743 drm_dp_mst_topology_mgr_invalidate_mstb(mgr->mst_primary); 3744 mutex_unlock(&mgr->lock); 3745 } 3746 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_suspend); 3747 3748 /** 3749 * drm_dp_mst_topology_mgr_resume() - resume the MST manager 3750 * @mgr: manager to resume 3751 * @sync: whether or not to perform topology reprobing synchronously 3752 * 3753 * This will fetch DPCD and see if the device is still there, 3754 * if it is, it will rewrite the MSTM control bits, and return. 3755 * 3756 * If the device fails this returns -1, and the driver should do 3757 * a full MST reprobe, in case we were undocked. 3758 * 3759 * During system resume (where it is assumed that the driver will be calling 3760 * drm_atomic_helper_resume()) this function should be called beforehand with 3761 * @sync set to true. In contexts like runtime resume where the driver is not 3762 * expected to be calling drm_atomic_helper_resume(), this function should be 3763 * called with @sync set to false in order to avoid deadlocking. 3764 * 3765 * Returns: -1 if the MST topology was removed while we were suspended, 0 3766 * otherwise. 3767 */ 3768 int drm_dp_mst_topology_mgr_resume(struct drm_dp_mst_topology_mgr *mgr, 3769 bool sync) 3770 { 3771 u8 buf[UUID_SIZE]; 3772 guid_t guid; 3773 int ret; 3774 3775 mutex_lock(&mgr->lock); 3776 if (!mgr->mst_primary) 3777 goto out_fail; 3778 3779 if (drm_dp_read_dpcd_caps(mgr->aux, mgr->dpcd) < 0) { 3780 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n"); 3781 goto out_fail; 3782 } 3783 3784 ret = drm_dp_dpcd_writeb(mgr->aux, DP_MSTM_CTRL, 3785 DP_MST_EN | 3786 DP_UP_REQ_EN | 3787 DP_UPSTREAM_IS_SRC); 3788 if (ret < 0) { 3789 drm_dbg_kms(mgr->dev, "mst write failed - undocked during suspend?\n"); 3790 goto out_fail; 3791 } 3792 3793 /* Some hubs forget their guids after they resume */ 3794 ret = drm_dp_dpcd_read(mgr->aux, DP_GUID, buf, sizeof(buf)); 3795 if (ret != sizeof(buf)) { 3796 drm_dbg_kms(mgr->dev, "dpcd read failed - undocked during suspend?\n"); 3797 goto out_fail; 3798 } 3799 3800 import_guid(&guid, buf); 3801 3802 ret = drm_dp_check_mstb_guid(mgr->mst_primary, &guid); 3803 if (ret) { 3804 drm_dbg_kms(mgr->dev, "check mstb failed - undocked during suspend?\n"); 3805 goto out_fail; 3806 } 3807 3808 /* 3809 * For the final step of resuming the topology, we need to bring the 3810 * state of our in-memory topology back into sync with reality. So, 3811 * restart the probing process as if we're probing a new hub 3812 */ 3813 queue_work(system_long_wq, &mgr->work); 3814 mutex_unlock(&mgr->lock); 3815 3816 if (sync) { 3817 drm_dbg_kms(mgr->dev, 3818 "Waiting for link probe work to finish re-syncing topology...\n"); 3819 flush_work(&mgr->work); 3820 } 3821 3822 return 0; 3823 3824 out_fail: 3825 mutex_unlock(&mgr->lock); 3826 return -1; 3827 } 3828 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_resume); 3829 3830 static bool 3831 drm_dp_get_one_sb_msg(struct drm_dp_mst_topology_mgr *mgr, bool up, 3832 struct drm_dp_mst_branch **mstb) 3833 { 3834 int len; 3835 u8 replyblock[32]; 3836 int replylen, curreply; 3837 int ret; 3838 u8 hdrlen; 3839 struct drm_dp_sideband_msg_hdr hdr; 3840 struct drm_dp_sideband_msg_rx *msg = 3841 up ? &mgr->up_req_recv : &mgr->down_rep_recv; 3842 int basereg = up ? DP_SIDEBAND_MSG_UP_REQ_BASE : 3843 DP_SIDEBAND_MSG_DOWN_REP_BASE; 3844 3845 if (!up) 3846 *mstb = NULL; 3847 3848 len = min(mgr->max_dpcd_transaction_bytes, 16); 3849 ret = drm_dp_dpcd_read(mgr->aux, basereg, replyblock, len); 3850 if (ret != len) { 3851 drm_dbg_kms(mgr->dev, "failed to read DPCD down rep %d %d\n", len, ret); 3852 return false; 3853 } 3854 3855 ret = drm_dp_decode_sideband_msg_hdr(mgr, &hdr, replyblock, len, &hdrlen); 3856 if (ret == false) { 3857 print_hex_dump(KERN_DEBUG, "failed hdr", DUMP_PREFIX_NONE, 16, 3858 1, replyblock, len, false); 3859 drm_dbg_kms(mgr->dev, "ERROR: failed header\n"); 3860 return false; 3861 } 3862 3863 if (!up) { 3864 /* Caller is responsible for giving back this reference */ 3865 *mstb = drm_dp_get_mst_branch_device(mgr, hdr.lct, hdr.rad); 3866 if (!*mstb) { 3867 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr.lct); 3868 return false; 3869 } 3870 } 3871 3872 if (!drm_dp_sideband_msg_set_header(msg, &hdr, hdrlen)) { 3873 drm_dbg_kms(mgr->dev, "sideband msg set header failed %d\n", replyblock[0]); 3874 return false; 3875 } 3876 3877 replylen = min(msg->curchunk_len, (u8)(len - hdrlen)); 3878 ret = drm_dp_sideband_append_payload(msg, replyblock + hdrlen, replylen); 3879 if (!ret) { 3880 drm_dbg_kms(mgr->dev, "sideband msg build failed %d\n", replyblock[0]); 3881 return false; 3882 } 3883 3884 replylen = msg->curchunk_len + msg->curchunk_hdrlen - len; 3885 curreply = len; 3886 while (replylen > 0) { 3887 len = min3(replylen, mgr->max_dpcd_transaction_bytes, 16); 3888 ret = drm_dp_dpcd_read(mgr->aux, basereg + curreply, 3889 replyblock, len); 3890 if (ret != len) { 3891 drm_dbg_kms(mgr->dev, "failed to read a chunk (len %d, ret %d)\n", 3892 len, ret); 3893 return false; 3894 } 3895 3896 ret = drm_dp_sideband_append_payload(msg, replyblock, len); 3897 if (!ret) { 3898 drm_dbg_kms(mgr->dev, "failed to build sideband msg\n"); 3899 return false; 3900 } 3901 3902 curreply += len; 3903 replylen -= len; 3904 } 3905 return true; 3906 } 3907 3908 static int drm_dp_mst_handle_down_rep(struct drm_dp_mst_topology_mgr *mgr) 3909 { 3910 struct drm_dp_sideband_msg_tx *txmsg; 3911 struct drm_dp_mst_branch *mstb = NULL; 3912 struct drm_dp_sideband_msg_rx *msg = &mgr->down_rep_recv; 3913 3914 if (!drm_dp_get_one_sb_msg(mgr, false, &mstb)) 3915 goto out_clear_reply; 3916 3917 /* Multi-packet message transmission, don't clear the reply */ 3918 if (!msg->have_eomt) 3919 goto out; 3920 3921 /* find the message */ 3922 mutex_lock(&mgr->qlock); 3923 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq, 3924 struct drm_dp_sideband_msg_tx, next); 3925 mutex_unlock(&mgr->qlock); 3926 3927 /* Were we actually expecting a response, and from this mstb? */ 3928 if (!txmsg || txmsg->dst != mstb) { 3929 struct drm_dp_sideband_msg_hdr *hdr; 3930 3931 hdr = &msg->initial_hdr; 3932 drm_dbg_kms(mgr->dev, "Got MST reply with no msg %p %d %d %02x %02x\n", 3933 mstb, hdr->seqno, hdr->lct, hdr->rad[0], msg->msg[0]); 3934 goto out_clear_reply; 3935 } 3936 3937 drm_dp_sideband_parse_reply(mgr, msg, &txmsg->reply); 3938 3939 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 3940 drm_dbg_kms(mgr->dev, 3941 "Got NAK reply: req 0x%02x (%s), reason 0x%02x (%s), nak data 0x%02x\n", 3942 txmsg->reply.req_type, 3943 drm_dp_mst_req_type_str(txmsg->reply.req_type), 3944 txmsg->reply.u.nak.reason, 3945 drm_dp_mst_nak_reason_str(txmsg->reply.u.nak.reason), 3946 txmsg->reply.u.nak.nak_data); 3947 } 3948 3949 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx)); 3950 drm_dp_mst_topology_put_mstb(mstb); 3951 3952 mutex_lock(&mgr->qlock); 3953 txmsg->state = DRM_DP_SIDEBAND_TX_RX; 3954 list_del(&txmsg->next); 3955 mutex_unlock(&mgr->qlock); 3956 3957 wake_up_all(&mgr->tx_waitq); 3958 3959 return 0; 3960 3961 out_clear_reply: 3962 memset(msg, 0, sizeof(struct drm_dp_sideband_msg_rx)); 3963 out: 3964 if (mstb) 3965 drm_dp_mst_topology_put_mstb(mstb); 3966 3967 return 0; 3968 } 3969 3970 static inline bool 3971 drm_dp_mst_process_up_req(struct drm_dp_mst_topology_mgr *mgr, 3972 struct drm_dp_pending_up_req *up_req) 3973 { 3974 struct drm_dp_mst_branch *mstb = NULL; 3975 struct drm_dp_sideband_msg_req_body *msg = &up_req->msg; 3976 struct drm_dp_sideband_msg_hdr *hdr = &up_req->hdr; 3977 bool hotplug = false, dowork = false; 3978 3979 if (hdr->broadcast) { 3980 const guid_t *guid = NULL; 3981 3982 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) 3983 guid = &msg->u.conn_stat.guid; 3984 else if (msg->req_type == DP_RESOURCE_STATUS_NOTIFY) 3985 guid = &msg->u.resource_stat.guid; 3986 3987 if (guid) 3988 mstb = drm_dp_get_mst_branch_device_by_guid(mgr, guid); 3989 } else { 3990 mstb = drm_dp_get_mst_branch_device(mgr, hdr->lct, hdr->rad); 3991 } 3992 3993 if (!mstb) { 3994 drm_dbg_kms(mgr->dev, "Got MST reply from unknown device %d\n", hdr->lct); 3995 return false; 3996 } 3997 3998 /* TODO: Add missing handler for DP_RESOURCE_STATUS_NOTIFY events */ 3999 if (msg->req_type == DP_CONNECTION_STATUS_NOTIFY) { 4000 dowork = drm_dp_mst_handle_conn_stat(mstb, &msg->u.conn_stat); 4001 hotplug = true; 4002 } 4003 4004 drm_dp_mst_topology_put_mstb(mstb); 4005 4006 if (dowork) 4007 queue_work(system_long_wq, &mgr->work); 4008 return hotplug; 4009 } 4010 4011 static void drm_dp_mst_up_req_work(struct work_struct *work) 4012 { 4013 struct drm_dp_mst_topology_mgr *mgr = 4014 container_of(work, struct drm_dp_mst_topology_mgr, 4015 up_req_work); 4016 struct drm_dp_pending_up_req *up_req; 4017 bool send_hotplug = false; 4018 4019 mutex_lock(&mgr->probe_lock); 4020 while (true) { 4021 mutex_lock(&mgr->up_req_lock); 4022 up_req = list_first_entry_or_null(&mgr->up_req_list, 4023 struct drm_dp_pending_up_req, 4024 next); 4025 if (up_req) 4026 list_del(&up_req->next); 4027 mutex_unlock(&mgr->up_req_lock); 4028 4029 if (!up_req) 4030 break; 4031 4032 send_hotplug |= drm_dp_mst_process_up_req(mgr, up_req); 4033 kfree(up_req); 4034 } 4035 mutex_unlock(&mgr->probe_lock); 4036 4037 if (send_hotplug) 4038 drm_kms_helper_hotplug_event(mgr->dev); 4039 } 4040 4041 static int drm_dp_mst_handle_up_req(struct drm_dp_mst_topology_mgr *mgr) 4042 { 4043 struct drm_dp_pending_up_req *up_req; 4044 4045 if (!drm_dp_get_one_sb_msg(mgr, true, NULL)) 4046 goto out; 4047 4048 if (!mgr->up_req_recv.have_eomt) 4049 return 0; 4050 4051 up_req = kzalloc(sizeof(*up_req), GFP_KERNEL); 4052 if (!up_req) 4053 return -ENOMEM; 4054 4055 INIT_LIST_HEAD(&up_req->next); 4056 4057 drm_dp_sideband_parse_req(mgr, &mgr->up_req_recv, &up_req->msg); 4058 4059 if (up_req->msg.req_type != DP_CONNECTION_STATUS_NOTIFY && 4060 up_req->msg.req_type != DP_RESOURCE_STATUS_NOTIFY) { 4061 drm_dbg_kms(mgr->dev, "Received unknown up req type, ignoring: %x\n", 4062 up_req->msg.req_type); 4063 kfree(up_req); 4064 goto out; 4065 } 4066 4067 drm_dp_send_up_ack_reply(mgr, mgr->mst_primary, up_req->msg.req_type, 4068 false); 4069 4070 if (up_req->msg.req_type == DP_CONNECTION_STATUS_NOTIFY) { 4071 const struct drm_dp_connection_status_notify *conn_stat = 4072 &up_req->msg.u.conn_stat; 4073 bool handle_csn; 4074 4075 drm_dbg_kms(mgr->dev, "Got CSN: pn: %d ldps:%d ddps: %d mcs: %d ip: %d pdt: %d\n", 4076 conn_stat->port_number, 4077 conn_stat->legacy_device_plug_status, 4078 conn_stat->displayport_device_plug_status, 4079 conn_stat->message_capability_status, 4080 conn_stat->input_port, 4081 conn_stat->peer_device_type); 4082 4083 mutex_lock(&mgr->probe_lock); 4084 handle_csn = mgr->mst_primary->link_address_sent; 4085 mutex_unlock(&mgr->probe_lock); 4086 4087 if (!handle_csn) { 4088 drm_dbg_kms(mgr->dev, "Got CSN before finish topology probing. Skip it."); 4089 kfree(up_req); 4090 goto out; 4091 } 4092 } else if (up_req->msg.req_type == DP_RESOURCE_STATUS_NOTIFY) { 4093 const struct drm_dp_resource_status_notify *res_stat = 4094 &up_req->msg.u.resource_stat; 4095 4096 drm_dbg_kms(mgr->dev, "Got RSN: pn: %d avail_pbn %d\n", 4097 res_stat->port_number, 4098 res_stat->available_pbn); 4099 } 4100 4101 up_req->hdr = mgr->up_req_recv.initial_hdr; 4102 mutex_lock(&mgr->up_req_lock); 4103 list_add_tail(&up_req->next, &mgr->up_req_list); 4104 mutex_unlock(&mgr->up_req_lock); 4105 queue_work(system_long_wq, &mgr->up_req_work); 4106 4107 out: 4108 memset(&mgr->up_req_recv, 0, sizeof(struct drm_dp_sideband_msg_rx)); 4109 return 0; 4110 } 4111 4112 /** 4113 * drm_dp_mst_hpd_irq_handle_event() - MST hotplug IRQ handle MST event 4114 * @mgr: manager to notify irq for. 4115 * @esi: 4 bytes from SINK_COUNT_ESI 4116 * @ack: 4 bytes used to ack events starting from SINK_COUNT_ESI 4117 * @handled: whether the hpd interrupt was consumed or not 4118 * 4119 * This should be called from the driver when it detects a HPD IRQ, 4120 * along with the value of the DEVICE_SERVICE_IRQ_VECTOR_ESI0. The 4121 * topology manager will process the sideband messages received 4122 * as indicated in the DEVICE_SERVICE_IRQ_VECTOR_ESI0 and set the 4123 * corresponding flags that Driver has to ack the DP receiver later. 4124 * 4125 * Note that driver shall also call 4126 * drm_dp_mst_hpd_irq_send_new_request() if the 'handled' is set 4127 * after calling this function, to try to kick off a new request in 4128 * the queue if the previous message transaction is completed. 4129 * 4130 * See also: 4131 * drm_dp_mst_hpd_irq_send_new_request() 4132 */ 4133 int drm_dp_mst_hpd_irq_handle_event(struct drm_dp_mst_topology_mgr *mgr, const u8 *esi, 4134 u8 *ack, bool *handled) 4135 { 4136 int ret = 0; 4137 int sc; 4138 *handled = false; 4139 sc = DP_GET_SINK_COUNT(esi[0]); 4140 4141 if (sc != mgr->sink_count) { 4142 mgr->sink_count = sc; 4143 *handled = true; 4144 } 4145 4146 if (esi[1] & DP_DOWN_REP_MSG_RDY) { 4147 ret = drm_dp_mst_handle_down_rep(mgr); 4148 *handled = true; 4149 ack[1] |= DP_DOWN_REP_MSG_RDY; 4150 } 4151 4152 if (esi[1] & DP_UP_REQ_MSG_RDY) { 4153 ret |= drm_dp_mst_handle_up_req(mgr); 4154 *handled = true; 4155 ack[1] |= DP_UP_REQ_MSG_RDY; 4156 } 4157 4158 return ret; 4159 } 4160 EXPORT_SYMBOL(drm_dp_mst_hpd_irq_handle_event); 4161 4162 /** 4163 * drm_dp_mst_hpd_irq_send_new_request() - MST hotplug IRQ kick off new request 4164 * @mgr: manager to notify irq for. 4165 * 4166 * This should be called from the driver when mst irq event is handled 4167 * and acked. Note that new down request should only be sent when 4168 * previous message transaction is completed. Source is not supposed to generate 4169 * interleaved message transactions. 4170 */ 4171 void drm_dp_mst_hpd_irq_send_new_request(struct drm_dp_mst_topology_mgr *mgr) 4172 { 4173 struct drm_dp_sideband_msg_tx *txmsg; 4174 bool kick = true; 4175 4176 mutex_lock(&mgr->qlock); 4177 txmsg = list_first_entry_or_null(&mgr->tx_msg_downq, 4178 struct drm_dp_sideband_msg_tx, next); 4179 /* If last transaction is not completed yet*/ 4180 if (!txmsg || 4181 txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND || 4182 txmsg->state == DRM_DP_SIDEBAND_TX_SENT) 4183 kick = false; 4184 mutex_unlock(&mgr->qlock); 4185 4186 if (kick) 4187 drm_dp_mst_kick_tx(mgr); 4188 } 4189 EXPORT_SYMBOL(drm_dp_mst_hpd_irq_send_new_request); 4190 /** 4191 * drm_dp_mst_detect_port() - get connection status for an MST port 4192 * @connector: DRM connector for this port 4193 * @ctx: The acquisition context to use for grabbing locks 4194 * @mgr: manager for this port 4195 * @port: pointer to a port 4196 * 4197 * This returns the current connection state for a port. 4198 */ 4199 int 4200 drm_dp_mst_detect_port(struct drm_connector *connector, 4201 struct drm_modeset_acquire_ctx *ctx, 4202 struct drm_dp_mst_topology_mgr *mgr, 4203 struct drm_dp_mst_port *port) 4204 { 4205 int ret; 4206 4207 /* we need to search for the port in the mgr in case it's gone */ 4208 port = drm_dp_mst_topology_get_port_validated(mgr, port); 4209 if (!port) 4210 return connector_status_disconnected; 4211 4212 ret = drm_modeset_lock(&mgr->base.lock, ctx); 4213 if (ret) 4214 goto out; 4215 4216 ret = connector_status_disconnected; 4217 4218 if (!port->ddps) 4219 goto out; 4220 4221 switch (port->pdt) { 4222 case DP_PEER_DEVICE_NONE: 4223 break; 4224 case DP_PEER_DEVICE_MST_BRANCHING: 4225 if (!port->mcs) 4226 ret = connector_status_connected; 4227 break; 4228 4229 case DP_PEER_DEVICE_SST_SINK: 4230 ret = connector_status_connected; 4231 /* for logical ports - cache the EDID */ 4232 if (drm_dp_mst_port_is_logical(port) && !port->cached_edid) 4233 port->cached_edid = drm_edid_read_ddc(connector, &port->aux.ddc); 4234 break; 4235 case DP_PEER_DEVICE_DP_LEGACY_CONV: 4236 if (port->ldps) 4237 ret = connector_status_connected; 4238 break; 4239 } 4240 out: 4241 drm_dp_mst_topology_put_port(port); 4242 return ret; 4243 } 4244 EXPORT_SYMBOL(drm_dp_mst_detect_port); 4245 4246 /** 4247 * drm_dp_mst_edid_read() - get EDID for an MST port 4248 * @connector: toplevel connector to get EDID for 4249 * @mgr: manager for this port 4250 * @port: unverified pointer to a port. 4251 * 4252 * This returns an EDID for the port connected to a connector, 4253 * It validates the pointer still exists so the caller doesn't require a 4254 * reference. 4255 */ 4256 const struct drm_edid *drm_dp_mst_edid_read(struct drm_connector *connector, 4257 struct drm_dp_mst_topology_mgr *mgr, 4258 struct drm_dp_mst_port *port) 4259 { 4260 const struct drm_edid *drm_edid; 4261 4262 /* we need to search for the port in the mgr in case it's gone */ 4263 port = drm_dp_mst_topology_get_port_validated(mgr, port); 4264 if (!port) 4265 return NULL; 4266 4267 if (port->cached_edid) 4268 drm_edid = drm_edid_dup(port->cached_edid); 4269 else 4270 drm_edid = drm_edid_read_ddc(connector, &port->aux.ddc); 4271 4272 drm_dp_mst_topology_put_port(port); 4273 4274 return drm_edid; 4275 } 4276 EXPORT_SYMBOL(drm_dp_mst_edid_read); 4277 4278 /** 4279 * drm_dp_mst_get_edid() - get EDID for an MST port 4280 * @connector: toplevel connector to get EDID for 4281 * @mgr: manager for this port 4282 * @port: unverified pointer to a port. 4283 * 4284 * This function is deprecated; please use drm_dp_mst_edid_read() instead. 4285 * 4286 * This returns an EDID for the port connected to a connector, 4287 * It validates the pointer still exists so the caller doesn't require a 4288 * reference. 4289 */ 4290 struct edid *drm_dp_mst_get_edid(struct drm_connector *connector, 4291 struct drm_dp_mst_topology_mgr *mgr, 4292 struct drm_dp_mst_port *port) 4293 { 4294 const struct drm_edid *drm_edid; 4295 struct edid *edid; 4296 4297 drm_edid = drm_dp_mst_edid_read(connector, mgr, port); 4298 4299 edid = drm_edid_duplicate(drm_edid_raw(drm_edid)); 4300 4301 drm_edid_free(drm_edid); 4302 4303 return edid; 4304 } 4305 EXPORT_SYMBOL(drm_dp_mst_get_edid); 4306 4307 /** 4308 * drm_dp_atomic_find_time_slots() - Find and add time slots to the state 4309 * @state: global atomic state 4310 * @mgr: MST topology manager for the port 4311 * @port: port to find time slots for 4312 * @pbn: bandwidth required for the mode in PBN 4313 * 4314 * Allocates time slots to @port, replacing any previous time slot allocations it may 4315 * have had. Any atomic drivers which support MST must call this function in 4316 * their &drm_encoder_helper_funcs.atomic_check() callback unconditionally to 4317 * change the current time slot allocation for the new state, and ensure the MST 4318 * atomic state is added whenever the state of payloads in the topology changes. 4319 * 4320 * Allocations set by this function are not checked against the bandwidth 4321 * restraints of @mgr until the driver calls drm_dp_mst_atomic_check(). 4322 * 4323 * Additionally, it is OK to call this function multiple times on the same 4324 * @port as needed. It is not OK however, to call this function and 4325 * drm_dp_atomic_release_time_slots() in the same atomic check phase. 4326 * 4327 * See also: 4328 * drm_dp_atomic_release_time_slots() 4329 * drm_dp_mst_atomic_check() 4330 * 4331 * Returns: 4332 * Total slots in the atomic state assigned for this port, or a negative error 4333 * code if the port no longer exists 4334 */ 4335 int drm_dp_atomic_find_time_slots(struct drm_atomic_state *state, 4336 struct drm_dp_mst_topology_mgr *mgr, 4337 struct drm_dp_mst_port *port, int pbn) 4338 { 4339 struct drm_dp_mst_topology_state *topology_state; 4340 struct drm_dp_mst_atomic_payload *payload = NULL; 4341 struct drm_connector_state *conn_state; 4342 int prev_slots = 0, prev_bw = 0, req_slots; 4343 4344 topology_state = drm_atomic_get_mst_topology_state(state, mgr); 4345 if (IS_ERR(topology_state)) 4346 return PTR_ERR(topology_state); 4347 4348 conn_state = drm_atomic_get_new_connector_state(state, port->connector); 4349 topology_state->pending_crtc_mask |= drm_crtc_mask(conn_state->crtc); 4350 4351 /* Find the current allocation for this port, if any */ 4352 payload = drm_atomic_get_mst_payload_state(topology_state, port); 4353 if (payload) { 4354 prev_slots = payload->time_slots; 4355 prev_bw = payload->pbn; 4356 4357 /* 4358 * This should never happen, unless the driver tries 4359 * releasing and allocating the same timeslot allocation, 4360 * which is an error 4361 */ 4362 if (drm_WARN_ON(mgr->dev, payload->delete)) { 4363 drm_err(mgr->dev, 4364 "cannot allocate and release time slots on [MST PORT:%p] in the same state\n", 4365 port); 4366 return -EINVAL; 4367 } 4368 } 4369 4370 req_slots = DIV_ROUND_UP(dfixed_const(pbn), topology_state->pbn_div.full); 4371 4372 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] TU %d -> %d\n", 4373 port->connector->base.id, port->connector->name, 4374 port, prev_slots, req_slots); 4375 drm_dbg_atomic(mgr->dev, "[CONNECTOR:%d:%s] [MST PORT:%p] PBN %d -> %d\n", 4376 port->connector->base.id, port->connector->name, 4377 port, prev_bw, pbn); 4378 4379 /* Add the new allocation to the state, note the VCPI isn't assigned until the end */ 4380 if (!payload) { 4381 payload = kzalloc(sizeof(*payload), GFP_KERNEL); 4382 if (!payload) 4383 return -ENOMEM; 4384 4385 drm_dp_mst_get_port_malloc(port); 4386 payload->port = port; 4387 payload->vc_start_slot = -1; 4388 payload->payload_allocation_status = DRM_DP_MST_PAYLOAD_ALLOCATION_NONE; 4389 list_add(&payload->next, &topology_state->payloads); 4390 } 4391 payload->time_slots = req_slots; 4392 payload->pbn = pbn; 4393 4394 return req_slots; 4395 } 4396 EXPORT_SYMBOL(drm_dp_atomic_find_time_slots); 4397 4398 /** 4399 * drm_dp_atomic_release_time_slots() - Release allocated time slots 4400 * @state: global atomic state 4401 * @mgr: MST topology manager for the port 4402 * @port: The port to release the time slots from 4403 * 4404 * Releases any time slots that have been allocated to a port in the atomic 4405 * state. Any atomic drivers which support MST must call this function 4406 * unconditionally in their &drm_connector_helper_funcs.atomic_check() callback. 4407 * This helper will check whether time slots would be released by the new state and 4408 * respond accordingly, along with ensuring the MST state is always added to the 4409 * atomic state whenever a new state would modify the state of payloads on the 4410 * topology. 4411 * 4412 * It is OK to call this even if @port has been removed from the system. 4413 * Additionally, it is OK to call this function multiple times on the same 4414 * @port as needed. It is not OK however, to call this function and 4415 * drm_dp_atomic_find_time_slots() on the same @port in a single atomic check 4416 * phase. 4417 * 4418 * See also: 4419 * drm_dp_atomic_find_time_slots() 4420 * drm_dp_mst_atomic_check() 4421 * 4422 * Returns: 4423 * 0 on success, negative error code otherwise 4424 */ 4425 int drm_dp_atomic_release_time_slots(struct drm_atomic_state *state, 4426 struct drm_dp_mst_topology_mgr *mgr, 4427 struct drm_dp_mst_port *port) 4428 { 4429 struct drm_dp_mst_topology_state *topology_state; 4430 struct drm_dp_mst_atomic_payload *payload; 4431 struct drm_connector_state *old_conn_state, *new_conn_state; 4432 bool update_payload = true; 4433 4434 old_conn_state = drm_atomic_get_old_connector_state(state, port->connector); 4435 if (!old_conn_state->crtc) 4436 return 0; 4437 4438 /* If the CRTC isn't disabled by this state, don't release it's payload */ 4439 new_conn_state = drm_atomic_get_new_connector_state(state, port->connector); 4440 if (new_conn_state->crtc) { 4441 struct drm_crtc_state *crtc_state = 4442 drm_atomic_get_new_crtc_state(state, new_conn_state->crtc); 4443 4444 /* No modeset means no payload changes, so it's safe to not pull in the MST state */ 4445 if (!crtc_state || !drm_atomic_crtc_needs_modeset(crtc_state)) 4446 return 0; 4447 4448 if (!crtc_state->mode_changed && !crtc_state->connectors_changed) 4449 update_payload = false; 4450 } 4451 4452 topology_state = drm_atomic_get_mst_topology_state(state, mgr); 4453 if (IS_ERR(topology_state)) 4454 return PTR_ERR(topology_state); 4455 4456 topology_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc); 4457 if (!update_payload) 4458 return 0; 4459 4460 payload = drm_atomic_get_mst_payload_state(topology_state, port); 4461 if (WARN_ON(!payload)) { 4462 drm_err(mgr->dev, "No payload for [MST PORT:%p] found in mst state %p\n", 4463 port, &topology_state->base); 4464 return -EINVAL; 4465 } 4466 4467 if (new_conn_state->crtc) 4468 return 0; 4469 4470 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] TU %d -> 0\n", port, payload->time_slots); 4471 if (!payload->delete) { 4472 payload->pbn = 0; 4473 payload->delete = true; 4474 topology_state->payload_mask &= ~BIT(payload->vcpi - 1); 4475 } 4476 4477 return 0; 4478 } 4479 EXPORT_SYMBOL(drm_dp_atomic_release_time_slots); 4480 4481 /** 4482 * drm_dp_mst_atomic_setup_commit() - setup_commit hook for MST helpers 4483 * @state: global atomic state 4484 * 4485 * This function saves all of the &drm_crtc_commit structs in an atomic state that touch any CRTCs 4486 * currently assigned to an MST topology. Drivers must call this hook from their 4487 * &drm_mode_config_helper_funcs.atomic_commit_setup hook. 4488 * 4489 * Returns: 4490 * 0 if all CRTC commits were retrieved successfully, negative error code otherwise 4491 */ 4492 int drm_dp_mst_atomic_setup_commit(struct drm_atomic_state *state) 4493 { 4494 struct drm_dp_mst_topology_mgr *mgr; 4495 struct drm_dp_mst_topology_state *mst_state; 4496 struct drm_crtc *crtc; 4497 struct drm_crtc_state *crtc_state; 4498 int i, j, commit_idx, num_commit_deps; 4499 4500 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { 4501 if (!mst_state->pending_crtc_mask) 4502 continue; 4503 4504 num_commit_deps = hweight32(mst_state->pending_crtc_mask); 4505 mst_state->commit_deps = kmalloc_array(num_commit_deps, 4506 sizeof(*mst_state->commit_deps), GFP_KERNEL); 4507 if (!mst_state->commit_deps) 4508 return -ENOMEM; 4509 mst_state->num_commit_deps = num_commit_deps; 4510 4511 commit_idx = 0; 4512 for_each_new_crtc_in_state(state, crtc, crtc_state, j) { 4513 if (mst_state->pending_crtc_mask & drm_crtc_mask(crtc)) { 4514 mst_state->commit_deps[commit_idx++] = 4515 drm_crtc_commit_get(crtc_state->commit); 4516 } 4517 } 4518 } 4519 4520 return 0; 4521 } 4522 EXPORT_SYMBOL(drm_dp_mst_atomic_setup_commit); 4523 4524 /** 4525 * drm_dp_mst_atomic_wait_for_dependencies() - Wait for all pending commits on MST topologies, 4526 * prepare new MST state for commit 4527 * @state: global atomic state 4528 * 4529 * Goes through any MST topologies in this atomic state, and waits for any pending commits which 4530 * touched CRTCs that were/are on an MST topology to be programmed to hardware and flipped to before 4531 * returning. This is to prevent multiple non-blocking commits affecting an MST topology from racing 4532 * with eachother by forcing them to be executed sequentially in situations where the only resources 4533 * the modeset objects in these commits share are an MST topology. 4534 * 4535 * This function also prepares the new MST state for commit by performing some state preparation 4536 * which can't be done until this point, such as reading back the final VC start slots (which are 4537 * determined at commit-time) from the previous state. 4538 * 4539 * All MST drivers must call this function after calling drm_atomic_helper_wait_for_dependencies(), 4540 * or whatever their equivalent of that is. 4541 */ 4542 void drm_dp_mst_atomic_wait_for_dependencies(struct drm_atomic_state *state) 4543 { 4544 struct drm_dp_mst_topology_state *old_mst_state, *new_mst_state; 4545 struct drm_dp_mst_topology_mgr *mgr; 4546 struct drm_dp_mst_atomic_payload *old_payload, *new_payload; 4547 int i, j, ret; 4548 4549 for_each_oldnew_mst_mgr_in_state(state, mgr, old_mst_state, new_mst_state, i) { 4550 for (j = 0; j < old_mst_state->num_commit_deps; j++) { 4551 ret = drm_crtc_commit_wait(old_mst_state->commit_deps[j]); 4552 if (ret < 0) 4553 drm_err(state->dev, "Failed to wait for %s: %d\n", 4554 old_mst_state->commit_deps[j]->crtc->name, ret); 4555 } 4556 4557 /* Now that previous state is committed, it's safe to copy over the start slot 4558 * and allocation status assignments 4559 */ 4560 list_for_each_entry(old_payload, &old_mst_state->payloads, next) { 4561 if (old_payload->delete) 4562 continue; 4563 4564 new_payload = drm_atomic_get_mst_payload_state(new_mst_state, 4565 old_payload->port); 4566 new_payload->vc_start_slot = old_payload->vc_start_slot; 4567 new_payload->payload_allocation_status = 4568 old_payload->payload_allocation_status; 4569 } 4570 } 4571 } 4572 EXPORT_SYMBOL(drm_dp_mst_atomic_wait_for_dependencies); 4573 4574 /** 4575 * drm_dp_mst_root_conn_atomic_check() - Serialize CRTC commits on MST-capable connectors operating 4576 * in SST mode 4577 * @new_conn_state: The new connector state of the &drm_connector 4578 * @mgr: The MST topology manager for the &drm_connector 4579 * 4580 * Since MST uses fake &drm_encoder structs, the generic atomic modesetting code isn't able to 4581 * serialize non-blocking commits happening on the real DP connector of an MST topology switching 4582 * into/away from MST mode - as the CRTC on the real DP connector and the CRTCs on the connector's 4583 * MST topology will never share the same &drm_encoder. 4584 * 4585 * This function takes care of this serialization issue, by checking a root MST connector's atomic 4586 * state to determine if it is about to have a modeset - and then pulling in the MST topology state 4587 * if so, along with adding any relevant CRTCs to &drm_dp_mst_topology_state.pending_crtc_mask. 4588 * 4589 * Drivers implementing MST must call this function from the 4590 * &drm_connector_helper_funcs.atomic_check hook of any physical DP &drm_connector capable of 4591 * driving MST sinks. 4592 * 4593 * Returns: 4594 * 0 on success, negative error code otherwise 4595 */ 4596 int drm_dp_mst_root_conn_atomic_check(struct drm_connector_state *new_conn_state, 4597 struct drm_dp_mst_topology_mgr *mgr) 4598 { 4599 struct drm_atomic_state *state = new_conn_state->state; 4600 struct drm_connector_state *old_conn_state = 4601 drm_atomic_get_old_connector_state(state, new_conn_state->connector); 4602 struct drm_crtc_state *crtc_state; 4603 struct drm_dp_mst_topology_state *mst_state = NULL; 4604 4605 if (new_conn_state->crtc) { 4606 crtc_state = drm_atomic_get_new_crtc_state(state, new_conn_state->crtc); 4607 if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) { 4608 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 4609 if (IS_ERR(mst_state)) 4610 return PTR_ERR(mst_state); 4611 4612 mst_state->pending_crtc_mask |= drm_crtc_mask(new_conn_state->crtc); 4613 } 4614 } 4615 4616 if (old_conn_state->crtc) { 4617 crtc_state = drm_atomic_get_new_crtc_state(state, old_conn_state->crtc); 4618 if (crtc_state && drm_atomic_crtc_needs_modeset(crtc_state)) { 4619 if (!mst_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 4625 mst_state->pending_crtc_mask |= drm_crtc_mask(old_conn_state->crtc); 4626 } 4627 } 4628 4629 return 0; 4630 } 4631 EXPORT_SYMBOL(drm_dp_mst_root_conn_atomic_check); 4632 4633 /** 4634 * drm_dp_mst_update_slots() - updates the slot info depending on the DP ecoding format 4635 * @mst_state: mst_state to update 4636 * @link_encoding_cap: the ecoding format on the link 4637 */ 4638 void drm_dp_mst_update_slots(struct drm_dp_mst_topology_state *mst_state, uint8_t link_encoding_cap) 4639 { 4640 if (link_encoding_cap == DP_CAP_ANSI_128B132B) { 4641 mst_state->total_avail_slots = 64; 4642 mst_state->start_slot = 0; 4643 } else { 4644 mst_state->total_avail_slots = 63; 4645 mst_state->start_slot = 1; 4646 } 4647 4648 DRM_DEBUG_KMS("%s encoding format on mst_state 0x%p\n", 4649 (link_encoding_cap == DP_CAP_ANSI_128B132B) ? "128b/132b":"8b/10b", 4650 mst_state); 4651 } 4652 EXPORT_SYMBOL(drm_dp_mst_update_slots); 4653 4654 static int drm_dp_dpcd_write_payload(struct drm_dp_mst_topology_mgr *mgr, 4655 int id, u8 start_slot, u8 num_slots) 4656 { 4657 u8 payload_alloc[3], status; 4658 int ret; 4659 int retries = 0; 4660 4661 drm_dp_dpcd_writeb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, 4662 DP_PAYLOAD_TABLE_UPDATED); 4663 4664 payload_alloc[0] = id; 4665 payload_alloc[1] = start_slot; 4666 payload_alloc[2] = num_slots; 4667 4668 ret = drm_dp_dpcd_write(mgr->aux, DP_PAYLOAD_ALLOCATE_SET, payload_alloc, 3); 4669 if (ret != 3) { 4670 drm_dbg_kms(mgr->dev, "failed to write payload allocation %d\n", ret); 4671 goto fail; 4672 } 4673 4674 retry: 4675 ret = drm_dp_dpcd_readb(mgr->aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 4676 if (ret < 0) { 4677 drm_dbg_kms(mgr->dev, "failed to read payload table status %d\n", ret); 4678 goto fail; 4679 } 4680 4681 if (!(status & DP_PAYLOAD_TABLE_UPDATED)) { 4682 retries++; 4683 if (retries < 20) { 4684 usleep_range(10000, 20000); 4685 goto retry; 4686 } 4687 drm_dbg_kms(mgr->dev, "status not set after read payload table status %d\n", 4688 status); 4689 ret = -EINVAL; 4690 goto fail; 4691 } 4692 ret = 0; 4693 fail: 4694 return ret; 4695 } 4696 4697 static int do_get_act_status(struct drm_dp_aux *aux) 4698 { 4699 int ret; 4700 u8 status; 4701 4702 ret = drm_dp_dpcd_readb(aux, DP_PAYLOAD_TABLE_UPDATE_STATUS, &status); 4703 if (ret < 0) 4704 return ret; 4705 4706 return status; 4707 } 4708 4709 /** 4710 * drm_dp_check_act_status() - Polls for ACT handled status. 4711 * @mgr: manager to use 4712 * 4713 * Tries waiting for the MST hub to finish updating it's payload table by 4714 * polling for the ACT handled bit for up to 3 seconds (yes-some hubs really 4715 * take that long). 4716 * 4717 * Returns: 4718 * 0 if the ACT was handled in time, negative error code on failure. 4719 */ 4720 int drm_dp_check_act_status(struct drm_dp_mst_topology_mgr *mgr) 4721 { 4722 /* 4723 * There doesn't seem to be any recommended retry count or timeout in 4724 * the MST specification. Since some hubs have been observed to take 4725 * over 1 second to update their payload allocations under certain 4726 * conditions, we use a rather large timeout value. 4727 */ 4728 const int timeout_ms = 3000; 4729 int ret, status; 4730 4731 ret = readx_poll_timeout(do_get_act_status, mgr->aux, status, 4732 status & DP_PAYLOAD_ACT_HANDLED || status < 0, 4733 200, timeout_ms * USEC_PER_MSEC); 4734 if (ret < 0 && status >= 0) { 4735 drm_err(mgr->dev, "Failed to get ACT after %dms, last status: %02x\n", 4736 timeout_ms, status); 4737 return -EINVAL; 4738 } else if (status < 0) { 4739 /* 4740 * Failure here isn't unexpected - the hub may have 4741 * just been unplugged 4742 */ 4743 drm_dbg_kms(mgr->dev, "Failed to read payload table status: %d\n", status); 4744 return status; 4745 } 4746 4747 return 0; 4748 } 4749 EXPORT_SYMBOL(drm_dp_check_act_status); 4750 4751 /** 4752 * drm_dp_calc_pbn_mode() - Calculate the PBN for a mode. 4753 * @clock: dot clock 4754 * @bpp: bpp as .4 binary fixed point 4755 * 4756 * This uses the formula in the spec to calculate the PBN value for a mode. 4757 */ 4758 int drm_dp_calc_pbn_mode(int clock, int bpp) 4759 { 4760 /* 4761 * The unit of 54/64Mbytes/sec is an arbitrary unit chosen based on 4762 * common multiplier to render an integer PBN for all link rate/lane 4763 * counts combinations 4764 * calculate 4765 * peak_kbps = clock * bpp / 16 4766 * peak_kbps *= SSC overhead / 1000000 4767 * peak_kbps /= 8 convert to Kbytes 4768 * peak_kBps *= (64/54) / 1000 convert to PBN 4769 */ 4770 /* 4771 * TODO: Use the actual link and mode parameters to calculate 4772 * the overhead. For now it's assumed that these are 4773 * 4 link lanes, 4096 hactive pixels, which don't add any 4774 * significant data padding overhead and that there is no DSC 4775 * or FEC overhead. 4776 */ 4777 int overhead = drm_dp_bw_overhead(4, 4096, 0, bpp, 4778 DRM_DP_BW_OVERHEAD_MST | 4779 DRM_DP_BW_OVERHEAD_SSC_REF_CLK); 4780 4781 return DIV64_U64_ROUND_UP(mul_u32_u32(clock * bpp, 64 * overhead >> 4), 4782 1000000ULL * 8 * 54 * 1000); 4783 } 4784 EXPORT_SYMBOL(drm_dp_calc_pbn_mode); 4785 4786 /* we want to kick the TX after we've ack the up/down IRQs. */ 4787 static void drm_dp_mst_kick_tx(struct drm_dp_mst_topology_mgr *mgr) 4788 { 4789 queue_work(system_long_wq, &mgr->tx_work); 4790 } 4791 4792 /* 4793 * Helper function for parsing DP device types into convenient strings 4794 * for use with dp_mst_topology 4795 */ 4796 static const char *pdt_to_string(u8 pdt) 4797 { 4798 switch (pdt) { 4799 case DP_PEER_DEVICE_NONE: 4800 return "NONE"; 4801 case DP_PEER_DEVICE_SOURCE_OR_SST: 4802 return "SOURCE OR SST"; 4803 case DP_PEER_DEVICE_MST_BRANCHING: 4804 return "MST BRANCHING"; 4805 case DP_PEER_DEVICE_SST_SINK: 4806 return "SST SINK"; 4807 case DP_PEER_DEVICE_DP_LEGACY_CONV: 4808 return "DP LEGACY CONV"; 4809 default: 4810 return "ERR"; 4811 } 4812 } 4813 4814 static void drm_dp_mst_dump_mstb(struct seq_file *m, 4815 struct drm_dp_mst_branch *mstb) 4816 { 4817 struct drm_dp_mst_port *port; 4818 int tabs = mstb->lct; 4819 char prefix[10]; 4820 int i; 4821 4822 for (i = 0; i < tabs; i++) 4823 prefix[i] = '\t'; 4824 prefix[i] = '\0'; 4825 4826 seq_printf(m, "%smstb - [%p]: num_ports: %d\n", prefix, mstb, mstb->num_ports); 4827 list_for_each_entry(port, &mstb->ports, next) { 4828 seq_printf(m, "%sport %d - [%p] (%s - %s): ddps: %d, ldps: %d, sdp: %d/%d, fec: %s, conn: %p\n", 4829 prefix, 4830 port->port_num, 4831 port, 4832 port->input ? "input" : "output", 4833 pdt_to_string(port->pdt), 4834 port->ddps, 4835 port->ldps, 4836 port->num_sdp_streams, 4837 port->num_sdp_stream_sinks, 4838 port->fec_capable ? "true" : "false", 4839 port->connector); 4840 if (port->mstb) 4841 drm_dp_mst_dump_mstb(m, port->mstb); 4842 } 4843 } 4844 4845 #define DP_PAYLOAD_TABLE_SIZE 64 4846 4847 static bool dump_dp_payload_table(struct drm_dp_mst_topology_mgr *mgr, 4848 char *buf) 4849 { 4850 int i; 4851 4852 for (i = 0; i < DP_PAYLOAD_TABLE_SIZE; i += 16) { 4853 if (drm_dp_dpcd_read(mgr->aux, 4854 DP_PAYLOAD_TABLE_UPDATE_STATUS + i, 4855 &buf[i], 16) != 16) 4856 return false; 4857 } 4858 return true; 4859 } 4860 4861 static void fetch_monitor_name(struct drm_dp_mst_topology_mgr *mgr, 4862 struct drm_dp_mst_port *port, char *name, 4863 int namelen) 4864 { 4865 struct edid *mst_edid; 4866 4867 mst_edid = drm_dp_mst_get_edid(port->connector, mgr, port); 4868 drm_edid_get_monitor_name(mst_edid, name, namelen); 4869 kfree(mst_edid); 4870 } 4871 4872 /** 4873 * drm_dp_mst_dump_topology(): dump topology to seq file. 4874 * @m: seq_file to dump output to 4875 * @mgr: manager to dump current topology for. 4876 * 4877 * helper to dump MST topology to a seq file for debugfs. 4878 */ 4879 void drm_dp_mst_dump_topology(struct seq_file *m, 4880 struct drm_dp_mst_topology_mgr *mgr) 4881 { 4882 struct drm_dp_mst_topology_state *state; 4883 struct drm_dp_mst_atomic_payload *payload; 4884 int i, ret; 4885 4886 static const char *const status[] = { 4887 "None", 4888 "Local", 4889 "DFP", 4890 "Remote", 4891 }; 4892 4893 mutex_lock(&mgr->lock); 4894 if (mgr->mst_primary) 4895 drm_dp_mst_dump_mstb(m, mgr->mst_primary); 4896 4897 /* dump VCPIs */ 4898 mutex_unlock(&mgr->lock); 4899 4900 ret = drm_modeset_lock_single_interruptible(&mgr->base.lock); 4901 if (ret < 0) 4902 return; 4903 4904 state = to_drm_dp_mst_topology_state(mgr->base.state); 4905 seq_printf(m, "\n*** Atomic state info ***\n"); 4906 seq_printf(m, "payload_mask: %x, max_payloads: %d, start_slot: %u, pbn_div: %d\n", 4907 state->payload_mask, mgr->max_payloads, state->start_slot, 4908 dfixed_trunc(state->pbn_div)); 4909 4910 seq_printf(m, "\n| idx | port | vcpi | slots | pbn | dsc | status | sink name |\n"); 4911 for (i = 0; i < mgr->max_payloads; i++) { 4912 list_for_each_entry(payload, &state->payloads, next) { 4913 char name[14]; 4914 4915 if (payload->vcpi != i || payload->delete) 4916 continue; 4917 4918 fetch_monitor_name(mgr, payload->port, name, sizeof(name)); 4919 seq_printf(m, " %5d %6d %6d %02d - %02d %5d %5s %8s %19s\n", 4920 i, 4921 payload->port->port_num, 4922 payload->vcpi, 4923 payload->vc_start_slot, 4924 payload->vc_start_slot + payload->time_slots - 1, 4925 payload->pbn, 4926 payload->dsc_enabled ? "Y" : "N", 4927 status[payload->payload_allocation_status], 4928 (*name != 0) ? name : "Unknown"); 4929 } 4930 } 4931 4932 seq_printf(m, "\n*** DPCD Info ***\n"); 4933 mutex_lock(&mgr->lock); 4934 if (mgr->mst_primary) { 4935 u8 buf[DP_PAYLOAD_TABLE_SIZE]; 4936 int ret; 4937 4938 if (drm_dp_read_dpcd_caps(mgr->aux, buf) < 0) { 4939 seq_printf(m, "dpcd read failed\n"); 4940 goto out; 4941 } 4942 seq_printf(m, "dpcd: %*ph\n", DP_RECEIVER_CAP_SIZE, buf); 4943 4944 ret = drm_dp_dpcd_read(mgr->aux, DP_FAUX_CAP, buf, 2); 4945 if (ret != 2) { 4946 seq_printf(m, "faux/mst read failed\n"); 4947 goto out; 4948 } 4949 seq_printf(m, "faux/mst: %*ph\n", 2, buf); 4950 4951 ret = drm_dp_dpcd_read(mgr->aux, DP_MSTM_CTRL, buf, 1); 4952 if (ret != 1) { 4953 seq_printf(m, "mst ctrl read failed\n"); 4954 goto out; 4955 } 4956 seq_printf(m, "mst ctrl: %*ph\n", 1, buf); 4957 4958 /* dump the standard OUI branch header */ 4959 ret = drm_dp_dpcd_read(mgr->aux, DP_BRANCH_OUI, buf, DP_BRANCH_OUI_HEADER_SIZE); 4960 if (ret != DP_BRANCH_OUI_HEADER_SIZE) { 4961 seq_printf(m, "branch oui read failed\n"); 4962 goto out; 4963 } 4964 seq_printf(m, "branch oui: %*phN devid: ", 3, buf); 4965 4966 for (i = 0x3; i < 0x8 && buf[i]; i++) 4967 seq_putc(m, buf[i]); 4968 seq_printf(m, " revision: hw: %x.%x sw: %x.%x\n", 4969 buf[0x9] >> 4, buf[0x9] & 0xf, buf[0xa], buf[0xb]); 4970 if (dump_dp_payload_table(mgr, buf)) 4971 seq_printf(m, "payload table: %*ph\n", DP_PAYLOAD_TABLE_SIZE, buf); 4972 } 4973 4974 out: 4975 mutex_unlock(&mgr->lock); 4976 drm_modeset_unlock(&mgr->base.lock); 4977 } 4978 EXPORT_SYMBOL(drm_dp_mst_dump_topology); 4979 4980 static void drm_dp_tx_work(struct work_struct *work) 4981 { 4982 struct drm_dp_mst_topology_mgr *mgr = container_of(work, struct drm_dp_mst_topology_mgr, tx_work); 4983 4984 mutex_lock(&mgr->qlock); 4985 if (!list_empty(&mgr->tx_msg_downq)) 4986 process_single_down_tx_qlock(mgr); 4987 mutex_unlock(&mgr->qlock); 4988 } 4989 4990 static inline void 4991 drm_dp_delayed_destroy_port(struct drm_dp_mst_port *port) 4992 { 4993 drm_dp_port_set_pdt(port, DP_PEER_DEVICE_NONE, port->mcs); 4994 4995 if (port->connector) { 4996 drm_connector_unregister(port->connector); 4997 drm_connector_put(port->connector); 4998 } 4999 5000 drm_dp_mst_put_port_malloc(port); 5001 } 5002 5003 static inline void 5004 drm_dp_delayed_destroy_mstb(struct drm_dp_mst_branch *mstb) 5005 { 5006 struct drm_dp_mst_topology_mgr *mgr = mstb->mgr; 5007 struct drm_dp_mst_port *port, *port_tmp; 5008 struct drm_dp_sideband_msg_tx *txmsg, *txmsg_tmp; 5009 bool wake_tx = false; 5010 5011 mutex_lock(&mgr->lock); 5012 list_for_each_entry_safe(port, port_tmp, &mstb->ports, next) { 5013 list_del(&port->next); 5014 drm_dp_mst_topology_put_port(port); 5015 } 5016 mutex_unlock(&mgr->lock); 5017 5018 /* drop any tx slot msg */ 5019 mutex_lock(&mstb->mgr->qlock); 5020 list_for_each_entry_safe(txmsg, txmsg_tmp, &mgr->tx_msg_downq, next) { 5021 if (txmsg->dst != mstb) 5022 continue; 5023 5024 txmsg->state = DRM_DP_SIDEBAND_TX_TIMEOUT; 5025 list_del(&txmsg->next); 5026 wake_tx = true; 5027 } 5028 mutex_unlock(&mstb->mgr->qlock); 5029 5030 if (wake_tx) 5031 wake_up_all(&mstb->mgr->tx_waitq); 5032 5033 drm_dp_mst_put_mstb_malloc(mstb); 5034 } 5035 5036 static void drm_dp_delayed_destroy_work(struct work_struct *work) 5037 { 5038 struct drm_dp_mst_topology_mgr *mgr = 5039 container_of(work, struct drm_dp_mst_topology_mgr, 5040 delayed_destroy_work); 5041 bool send_hotplug = false, go_again; 5042 5043 /* 5044 * Not a regular list traverse as we have to drop the destroy 5045 * connector lock before destroying the mstb/port, to avoid AB->BA 5046 * ordering between this lock and the config mutex. 5047 */ 5048 do { 5049 go_again = false; 5050 5051 for (;;) { 5052 struct drm_dp_mst_branch *mstb; 5053 5054 mutex_lock(&mgr->delayed_destroy_lock); 5055 mstb = list_first_entry_or_null(&mgr->destroy_branch_device_list, 5056 struct drm_dp_mst_branch, 5057 destroy_next); 5058 if (mstb) 5059 list_del(&mstb->destroy_next); 5060 mutex_unlock(&mgr->delayed_destroy_lock); 5061 5062 if (!mstb) 5063 break; 5064 5065 drm_dp_delayed_destroy_mstb(mstb); 5066 go_again = true; 5067 } 5068 5069 for (;;) { 5070 struct drm_dp_mst_port *port; 5071 5072 mutex_lock(&mgr->delayed_destroy_lock); 5073 port = list_first_entry_or_null(&mgr->destroy_port_list, 5074 struct drm_dp_mst_port, 5075 next); 5076 if (port) 5077 list_del(&port->next); 5078 mutex_unlock(&mgr->delayed_destroy_lock); 5079 5080 if (!port) 5081 break; 5082 5083 drm_dp_delayed_destroy_port(port); 5084 send_hotplug = true; 5085 go_again = true; 5086 } 5087 } while (go_again); 5088 5089 if (send_hotplug) 5090 drm_kms_helper_hotplug_event(mgr->dev); 5091 } 5092 5093 static struct drm_private_state * 5094 drm_dp_mst_duplicate_state(struct drm_private_obj *obj) 5095 { 5096 struct drm_dp_mst_topology_state *state, *old_state = 5097 to_dp_mst_topology_state(obj->state); 5098 struct drm_dp_mst_atomic_payload *pos, *payload; 5099 5100 state = kmemdup(old_state, sizeof(*state), GFP_KERNEL); 5101 if (!state) 5102 return NULL; 5103 5104 __drm_atomic_helper_private_obj_duplicate_state(obj, &state->base); 5105 5106 INIT_LIST_HEAD(&state->payloads); 5107 state->commit_deps = NULL; 5108 state->num_commit_deps = 0; 5109 state->pending_crtc_mask = 0; 5110 5111 list_for_each_entry(pos, &old_state->payloads, next) { 5112 /* Prune leftover freed timeslot allocations */ 5113 if (pos->delete) 5114 continue; 5115 5116 payload = kmemdup(pos, sizeof(*payload), GFP_KERNEL); 5117 if (!payload) 5118 goto fail; 5119 5120 drm_dp_mst_get_port_malloc(payload->port); 5121 list_add(&payload->next, &state->payloads); 5122 } 5123 5124 return &state->base; 5125 5126 fail: 5127 list_for_each_entry_safe(pos, payload, &state->payloads, next) { 5128 drm_dp_mst_put_port_malloc(pos->port); 5129 kfree(pos); 5130 } 5131 kfree(state); 5132 5133 return NULL; 5134 } 5135 5136 static void drm_dp_mst_destroy_state(struct drm_private_obj *obj, 5137 struct drm_private_state *state) 5138 { 5139 struct drm_dp_mst_topology_state *mst_state = 5140 to_dp_mst_topology_state(state); 5141 struct drm_dp_mst_atomic_payload *pos, *tmp; 5142 int i; 5143 5144 list_for_each_entry_safe(pos, tmp, &mst_state->payloads, next) { 5145 /* We only keep references to ports with active payloads */ 5146 if (!pos->delete) 5147 drm_dp_mst_put_port_malloc(pos->port); 5148 kfree(pos); 5149 } 5150 5151 for (i = 0; i < mst_state->num_commit_deps; i++) 5152 drm_crtc_commit_put(mst_state->commit_deps[i]); 5153 5154 kfree(mst_state->commit_deps); 5155 kfree(mst_state); 5156 } 5157 5158 static bool drm_dp_mst_port_downstream_of_branch(struct drm_dp_mst_port *port, 5159 struct drm_dp_mst_branch *branch) 5160 { 5161 while (port->parent) { 5162 if (port->parent == branch) 5163 return true; 5164 5165 if (port->parent->port_parent) 5166 port = port->parent->port_parent; 5167 else 5168 break; 5169 } 5170 return false; 5171 } 5172 5173 static bool 5174 drm_dp_mst_port_downstream_of_parent_locked(struct drm_dp_mst_topology_mgr *mgr, 5175 struct drm_dp_mst_port *port, 5176 struct drm_dp_mst_port *parent) 5177 { 5178 if (!mgr->mst_primary) 5179 return false; 5180 5181 port = drm_dp_mst_topology_get_port_validated_locked(mgr->mst_primary, 5182 port); 5183 if (!port) 5184 return false; 5185 5186 if (!parent) 5187 return true; 5188 5189 parent = drm_dp_mst_topology_get_port_validated_locked(mgr->mst_primary, 5190 parent); 5191 if (!parent) 5192 return false; 5193 5194 if (!parent->mstb) 5195 return false; 5196 5197 return drm_dp_mst_port_downstream_of_branch(port, parent->mstb); 5198 } 5199 5200 /** 5201 * drm_dp_mst_port_downstream_of_parent - check if a port is downstream of a parent port 5202 * @mgr: MST topology manager 5203 * @port: the port being looked up 5204 * @parent: the parent port 5205 * 5206 * The function returns %true if @port is downstream of @parent. If @parent is 5207 * %NULL - denoting the root port - the function returns %true if @port is in 5208 * @mgr's topology. 5209 */ 5210 bool 5211 drm_dp_mst_port_downstream_of_parent(struct drm_dp_mst_topology_mgr *mgr, 5212 struct drm_dp_mst_port *port, 5213 struct drm_dp_mst_port *parent) 5214 { 5215 bool ret; 5216 5217 mutex_lock(&mgr->lock); 5218 ret = drm_dp_mst_port_downstream_of_parent_locked(mgr, port, parent); 5219 mutex_unlock(&mgr->lock); 5220 5221 return ret; 5222 } 5223 EXPORT_SYMBOL(drm_dp_mst_port_downstream_of_parent); 5224 5225 static int 5226 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, 5227 struct drm_dp_mst_topology_state *state, 5228 struct drm_dp_mst_port **failing_port); 5229 5230 static int 5231 drm_dp_mst_atomic_check_mstb_bw_limit(struct drm_dp_mst_branch *mstb, 5232 struct drm_dp_mst_topology_state *state, 5233 struct drm_dp_mst_port **failing_port) 5234 { 5235 struct drm_dp_mst_atomic_payload *payload; 5236 struct drm_dp_mst_port *port; 5237 int pbn_used = 0, ret; 5238 bool found = false; 5239 5240 /* Check that we have at least one port in our state that's downstream 5241 * of this branch, otherwise we can skip this branch 5242 */ 5243 list_for_each_entry(payload, &state->payloads, next) { 5244 if (!payload->pbn || 5245 !drm_dp_mst_port_downstream_of_branch(payload->port, mstb)) 5246 continue; 5247 5248 found = true; 5249 break; 5250 } 5251 if (!found) 5252 return 0; 5253 5254 if (mstb->port_parent) 5255 drm_dbg_atomic(mstb->mgr->dev, 5256 "[MSTB:%p] [MST PORT:%p] Checking bandwidth limits on [MSTB:%p]\n", 5257 mstb->port_parent->parent, mstb->port_parent, mstb); 5258 else 5259 drm_dbg_atomic(mstb->mgr->dev, "[MSTB:%p] Checking bandwidth limits\n", mstb); 5260 5261 list_for_each_entry(port, &mstb->ports, next) { 5262 ret = drm_dp_mst_atomic_check_port_bw_limit(port, state, failing_port); 5263 if (ret < 0) 5264 return ret; 5265 5266 pbn_used += ret; 5267 } 5268 5269 return pbn_used; 5270 } 5271 5272 static int 5273 drm_dp_mst_atomic_check_port_bw_limit(struct drm_dp_mst_port *port, 5274 struct drm_dp_mst_topology_state *state, 5275 struct drm_dp_mst_port **failing_port) 5276 { 5277 struct drm_dp_mst_atomic_payload *payload; 5278 int pbn_used = 0; 5279 5280 if (port->pdt == DP_PEER_DEVICE_NONE) 5281 return 0; 5282 5283 if (drm_dp_mst_is_end_device(port->pdt, port->mcs)) { 5284 payload = drm_atomic_get_mst_payload_state(state, port); 5285 if (!payload) 5286 return 0; 5287 5288 /* 5289 * This could happen if the sink deasserted its HPD line, but 5290 * the branch device still reports it as attached (PDT != NONE). 5291 */ 5292 if (!port->full_pbn) { 5293 drm_dbg_atomic(port->mgr->dev, 5294 "[MSTB:%p] [MST PORT:%p] no BW available for the port\n", 5295 port->parent, port); 5296 *failing_port = port; 5297 return -EINVAL; 5298 } 5299 5300 pbn_used = payload->pbn; 5301 } else { 5302 pbn_used = drm_dp_mst_atomic_check_mstb_bw_limit(port->mstb, 5303 state, 5304 failing_port); 5305 if (pbn_used <= 0) 5306 return pbn_used; 5307 } 5308 5309 if (pbn_used > port->full_pbn) { 5310 drm_dbg_atomic(port->mgr->dev, 5311 "[MSTB:%p] [MST PORT:%p] required PBN of %d exceeds port limit of %d\n", 5312 port->parent, port, pbn_used, port->full_pbn); 5313 *failing_port = port; 5314 return -ENOSPC; 5315 } 5316 5317 drm_dbg_atomic(port->mgr->dev, "[MSTB:%p] [MST PORT:%p] uses %d out of %d PBN\n", 5318 port->parent, port, pbn_used, port->full_pbn); 5319 5320 return pbn_used; 5321 } 5322 5323 static inline int 5324 drm_dp_mst_atomic_check_payload_alloc_limits(struct drm_dp_mst_topology_mgr *mgr, 5325 struct drm_dp_mst_topology_state *mst_state) 5326 { 5327 struct drm_dp_mst_atomic_payload *payload; 5328 int avail_slots = mst_state->total_avail_slots, payload_count = 0; 5329 5330 list_for_each_entry(payload, &mst_state->payloads, next) { 5331 /* Releasing payloads is always OK-even if the port is gone */ 5332 if (payload->delete) { 5333 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] releases all time slots\n", 5334 payload->port); 5335 continue; 5336 } 5337 5338 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] requires %d time slots\n", 5339 payload->port, payload->time_slots); 5340 5341 avail_slots -= payload->time_slots; 5342 if (avail_slots < 0) { 5343 drm_dbg_atomic(mgr->dev, 5344 "[MST PORT:%p] not enough time slots in mst state %p (avail=%d)\n", 5345 payload->port, mst_state, avail_slots + payload->time_slots); 5346 return -ENOSPC; 5347 } 5348 5349 if (++payload_count > mgr->max_payloads) { 5350 drm_dbg_atomic(mgr->dev, 5351 "[MST MGR:%p] state %p has too many payloads (max=%d)\n", 5352 mgr, mst_state, mgr->max_payloads); 5353 return -EINVAL; 5354 } 5355 5356 /* Assign a VCPI */ 5357 if (!payload->vcpi) { 5358 payload->vcpi = ffz(mst_state->payload_mask) + 1; 5359 drm_dbg_atomic(mgr->dev, "[MST PORT:%p] assigned VCPI #%d\n", 5360 payload->port, payload->vcpi); 5361 mst_state->payload_mask |= BIT(payload->vcpi - 1); 5362 } 5363 } 5364 5365 if (!payload_count) 5366 mst_state->pbn_div.full = dfixed_const(0); 5367 5368 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] mst state %p TU pbn_div=%d avail=%d used=%d\n", 5369 mgr, mst_state, dfixed_trunc(mst_state->pbn_div), avail_slots, 5370 mst_state->total_avail_slots - avail_slots); 5371 5372 return 0; 5373 } 5374 5375 /** 5376 * drm_dp_mst_add_affected_dsc_crtcs 5377 * @state: Pointer to the new struct drm_dp_mst_topology_state 5378 * @mgr: MST topology manager 5379 * 5380 * Whenever there is a change in mst topology 5381 * DSC configuration would have to be recalculated 5382 * therefore we need to trigger modeset on all affected 5383 * CRTCs in that topology 5384 * 5385 * See also: 5386 * drm_dp_mst_atomic_enable_dsc() 5387 */ 5388 int drm_dp_mst_add_affected_dsc_crtcs(struct drm_atomic_state *state, struct drm_dp_mst_topology_mgr *mgr) 5389 { 5390 struct drm_dp_mst_topology_state *mst_state; 5391 struct drm_dp_mst_atomic_payload *pos; 5392 struct drm_connector *connector; 5393 struct drm_connector_state *conn_state; 5394 struct drm_crtc *crtc; 5395 struct drm_crtc_state *crtc_state; 5396 5397 mst_state = drm_atomic_get_mst_topology_state(state, mgr); 5398 5399 if (IS_ERR(mst_state)) 5400 return PTR_ERR(mst_state); 5401 5402 list_for_each_entry(pos, &mst_state->payloads, next) { 5403 5404 connector = pos->port->connector; 5405 5406 if (!connector) 5407 return -EINVAL; 5408 5409 conn_state = drm_atomic_get_connector_state(state, connector); 5410 5411 if (IS_ERR(conn_state)) 5412 return PTR_ERR(conn_state); 5413 5414 crtc = conn_state->crtc; 5415 5416 if (!crtc) 5417 continue; 5418 5419 if (!drm_dp_mst_dsc_aux_for_port(pos->port)) 5420 continue; 5421 5422 crtc_state = drm_atomic_get_crtc_state(mst_state->base.state, crtc); 5423 5424 if (IS_ERR(crtc_state)) 5425 return PTR_ERR(crtc_state); 5426 5427 drm_dbg_atomic(mgr->dev, "[MST MGR:%p] Setting mode_changed flag on CRTC %p\n", 5428 mgr, crtc); 5429 5430 crtc_state->mode_changed = true; 5431 } 5432 return 0; 5433 } 5434 EXPORT_SYMBOL(drm_dp_mst_add_affected_dsc_crtcs); 5435 5436 /** 5437 * drm_dp_mst_atomic_enable_dsc - Set DSC Enable Flag to On/Off 5438 * @state: Pointer to the new drm_atomic_state 5439 * @port: Pointer to the affected MST Port 5440 * @pbn: Newly recalculated bw required for link with DSC enabled 5441 * @enable: Boolean flag to enable or disable DSC on the port 5442 * 5443 * This function enables DSC on the given Port 5444 * by recalculating its vcpi from pbn provided 5445 * and sets dsc_enable flag to keep track of which 5446 * ports have DSC enabled 5447 * 5448 */ 5449 int drm_dp_mst_atomic_enable_dsc(struct drm_atomic_state *state, 5450 struct drm_dp_mst_port *port, 5451 int pbn, bool enable) 5452 { 5453 struct drm_dp_mst_topology_state *mst_state; 5454 struct drm_dp_mst_atomic_payload *payload; 5455 int time_slots = 0; 5456 5457 mst_state = drm_atomic_get_mst_topology_state(state, port->mgr); 5458 if (IS_ERR(mst_state)) 5459 return PTR_ERR(mst_state); 5460 5461 payload = drm_atomic_get_mst_payload_state(mst_state, port); 5462 if (!payload) { 5463 drm_dbg_atomic(state->dev, 5464 "[MST PORT:%p] Couldn't find payload in mst state %p\n", 5465 port, mst_state); 5466 return -EINVAL; 5467 } 5468 5469 if (payload->dsc_enabled == enable) { 5470 drm_dbg_atomic(state->dev, 5471 "[MST PORT:%p] DSC flag is already set to %d, returning %d time slots\n", 5472 port, enable, payload->time_slots); 5473 time_slots = payload->time_slots; 5474 } 5475 5476 if (enable) { 5477 time_slots = drm_dp_atomic_find_time_slots(state, port->mgr, port, pbn); 5478 drm_dbg_atomic(state->dev, 5479 "[MST PORT:%p] Enabling DSC flag, reallocating %d time slots on the port\n", 5480 port, time_slots); 5481 if (time_slots < 0) 5482 return -EINVAL; 5483 } 5484 5485 payload->dsc_enabled = enable; 5486 5487 return time_slots; 5488 } 5489 EXPORT_SYMBOL(drm_dp_mst_atomic_enable_dsc); 5490 5491 /** 5492 * drm_dp_mst_atomic_check_mgr - Check the atomic state of an MST topology manager 5493 * @state: The global atomic state 5494 * @mgr: Manager to check 5495 * @mst_state: The MST atomic state for @mgr 5496 * @failing_port: Returns the port with a BW limitation 5497 * 5498 * Checks the given MST manager's topology state for an atomic update to ensure 5499 * that it's valid. This includes checking whether there's enough bandwidth to 5500 * support the new timeslot allocations in the atomic update. 5501 * 5502 * Any atomic drivers supporting DP MST must make sure to call this or 5503 * the drm_dp_mst_atomic_check() function after checking the rest of their state 5504 * in their &drm_mode_config_funcs.atomic_check() callback. 5505 * 5506 * See also: 5507 * drm_dp_mst_atomic_check() 5508 * drm_dp_atomic_find_time_slots() 5509 * drm_dp_atomic_release_time_slots() 5510 * 5511 * Returns: 5512 * - 0 if the new state is valid 5513 * - %-ENOSPC, if the new state is invalid, because of BW limitation 5514 * @failing_port is set to: 5515 * 5516 * - The non-root port where a BW limit check failed 5517 * with all the ports downstream of @failing_port passing 5518 * the BW limit check. 5519 * The returned port pointer is valid until at least 5520 * one payload downstream of it exists. 5521 * - %NULL if the BW limit check failed at the root port 5522 * with all the ports downstream of the root port passing 5523 * the BW limit check. 5524 * 5525 * - %-EINVAL, if the new state is invalid, because the root port has 5526 * too many payloads. 5527 */ 5528 int drm_dp_mst_atomic_check_mgr(struct drm_atomic_state *state, 5529 struct drm_dp_mst_topology_mgr *mgr, 5530 struct drm_dp_mst_topology_state *mst_state, 5531 struct drm_dp_mst_port **failing_port) 5532 { 5533 int ret; 5534 5535 *failing_port = NULL; 5536 5537 if (!mgr->mst_state) 5538 return 0; 5539 5540 mutex_lock(&mgr->lock); 5541 ret = drm_dp_mst_atomic_check_mstb_bw_limit(mgr->mst_primary, 5542 mst_state, 5543 failing_port); 5544 mutex_unlock(&mgr->lock); 5545 5546 if (ret < 0) 5547 return ret; 5548 5549 return drm_dp_mst_atomic_check_payload_alloc_limits(mgr, mst_state); 5550 } 5551 EXPORT_SYMBOL(drm_dp_mst_atomic_check_mgr); 5552 5553 /** 5554 * drm_dp_mst_atomic_check - Check that the new state of an MST topology in an 5555 * atomic update is valid 5556 * @state: Pointer to the new &struct drm_dp_mst_topology_state 5557 * 5558 * Checks the given topology state for an atomic update to ensure that it's 5559 * valid, calling drm_dp_mst_atomic_check_mgr() for all MST manager in the 5560 * atomic state. This includes checking whether there's enough bandwidth to 5561 * support the new timeslot allocations in the atomic update. 5562 * 5563 * Any atomic drivers supporting DP MST must make sure to call this after 5564 * checking the rest of their state in their 5565 * &drm_mode_config_funcs.atomic_check() callback. 5566 * 5567 * See also: 5568 * drm_dp_mst_atomic_check_mgr() 5569 * drm_dp_atomic_find_time_slots() 5570 * drm_dp_atomic_release_time_slots() 5571 * 5572 * Returns: 5573 * 0 if the new state is valid, negative error code otherwise. 5574 */ 5575 int drm_dp_mst_atomic_check(struct drm_atomic_state *state) 5576 { 5577 struct drm_dp_mst_topology_mgr *mgr; 5578 struct drm_dp_mst_topology_state *mst_state; 5579 int i, ret = 0; 5580 5581 for_each_new_mst_mgr_in_state(state, mgr, mst_state, i) { 5582 struct drm_dp_mst_port *tmp_port; 5583 5584 ret = drm_dp_mst_atomic_check_mgr(state, mgr, mst_state, &tmp_port); 5585 if (ret) 5586 break; 5587 } 5588 5589 return ret; 5590 } 5591 EXPORT_SYMBOL(drm_dp_mst_atomic_check); 5592 5593 const struct drm_private_state_funcs drm_dp_mst_topology_state_funcs = { 5594 .atomic_duplicate_state = drm_dp_mst_duplicate_state, 5595 .atomic_destroy_state = drm_dp_mst_destroy_state, 5596 }; 5597 EXPORT_SYMBOL(drm_dp_mst_topology_state_funcs); 5598 5599 /** 5600 * drm_atomic_get_mst_topology_state: get MST topology state 5601 * @state: global atomic state 5602 * @mgr: MST topology manager, also the private object in this case 5603 * 5604 * This function wraps drm_atomic_get_priv_obj_state() passing in the MST atomic 5605 * state vtable so that the private object state returned is that of a MST 5606 * topology object. 5607 * 5608 * RETURNS: 5609 * The MST topology state or error pointer. 5610 */ 5611 struct drm_dp_mst_topology_state *drm_atomic_get_mst_topology_state(struct drm_atomic_state *state, 5612 struct drm_dp_mst_topology_mgr *mgr) 5613 { 5614 return to_dp_mst_topology_state(drm_atomic_get_private_obj_state(state, &mgr->base)); 5615 } 5616 EXPORT_SYMBOL(drm_atomic_get_mst_topology_state); 5617 5618 /** 5619 * drm_atomic_get_old_mst_topology_state: get old MST topology state in atomic state, if any 5620 * @state: global atomic state 5621 * @mgr: MST topology manager, also the private object in this case 5622 * 5623 * This function wraps drm_atomic_get_old_private_obj_state() passing in the MST atomic 5624 * state vtable so that the private object state returned is that of a MST 5625 * topology object. 5626 * 5627 * Returns: 5628 * The old MST topology state, or NULL if there's no topology state for this MST mgr 5629 * in the global atomic state 5630 */ 5631 struct drm_dp_mst_topology_state * 5632 drm_atomic_get_old_mst_topology_state(struct drm_atomic_state *state, 5633 struct drm_dp_mst_topology_mgr *mgr) 5634 { 5635 struct drm_private_state *old_priv_state = 5636 drm_atomic_get_old_private_obj_state(state, &mgr->base); 5637 5638 return old_priv_state ? to_dp_mst_topology_state(old_priv_state) : NULL; 5639 } 5640 EXPORT_SYMBOL(drm_atomic_get_old_mst_topology_state); 5641 5642 /** 5643 * drm_atomic_get_new_mst_topology_state: get new MST topology state in atomic state, if any 5644 * @state: global atomic state 5645 * @mgr: MST topology manager, also the private object in this case 5646 * 5647 * This function wraps drm_atomic_get_new_private_obj_state() passing in the MST atomic 5648 * state vtable so that the private object state returned is that of a MST 5649 * topology object. 5650 * 5651 * Returns: 5652 * The new MST topology state, or NULL if there's no topology state for this MST mgr 5653 * in the global atomic state 5654 */ 5655 struct drm_dp_mst_topology_state * 5656 drm_atomic_get_new_mst_topology_state(struct drm_atomic_state *state, 5657 struct drm_dp_mst_topology_mgr *mgr) 5658 { 5659 struct drm_private_state *new_priv_state = 5660 drm_atomic_get_new_private_obj_state(state, &mgr->base); 5661 5662 return new_priv_state ? to_dp_mst_topology_state(new_priv_state) : NULL; 5663 } 5664 EXPORT_SYMBOL(drm_atomic_get_new_mst_topology_state); 5665 5666 /** 5667 * drm_dp_mst_topology_mgr_init - initialise a topology manager 5668 * @mgr: manager struct to initialise 5669 * @dev: device providing this structure - for i2c addition. 5670 * @aux: DP helper aux channel to talk to this device 5671 * @max_dpcd_transaction_bytes: hw specific DPCD transaction limit 5672 * @max_payloads: maximum number of payloads this GPU can source 5673 * @conn_base_id: the connector object ID the MST device is connected to. 5674 * 5675 * Return 0 for success, or negative error code on failure 5676 */ 5677 int drm_dp_mst_topology_mgr_init(struct drm_dp_mst_topology_mgr *mgr, 5678 struct drm_device *dev, struct drm_dp_aux *aux, 5679 int max_dpcd_transaction_bytes, int max_payloads, 5680 int conn_base_id) 5681 { 5682 struct drm_dp_mst_topology_state *mst_state; 5683 5684 mutex_init(&mgr->lock); 5685 mutex_init(&mgr->qlock); 5686 mutex_init(&mgr->delayed_destroy_lock); 5687 mutex_init(&mgr->up_req_lock); 5688 mutex_init(&mgr->probe_lock); 5689 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 5690 mutex_init(&mgr->topology_ref_history_lock); 5691 stack_depot_init(); 5692 #endif 5693 INIT_LIST_HEAD(&mgr->tx_msg_downq); 5694 INIT_LIST_HEAD(&mgr->destroy_port_list); 5695 INIT_LIST_HEAD(&mgr->destroy_branch_device_list); 5696 INIT_LIST_HEAD(&mgr->up_req_list); 5697 5698 /* 5699 * delayed_destroy_work will be queued on a dedicated WQ, so that any 5700 * requeuing will be also flushed when deiniting the topology manager. 5701 */ 5702 mgr->delayed_destroy_wq = alloc_ordered_workqueue("drm_dp_mst_wq", 0); 5703 if (mgr->delayed_destroy_wq == NULL) 5704 return -ENOMEM; 5705 5706 INIT_WORK(&mgr->work, drm_dp_mst_link_probe_work); 5707 INIT_WORK(&mgr->tx_work, drm_dp_tx_work); 5708 INIT_WORK(&mgr->delayed_destroy_work, drm_dp_delayed_destroy_work); 5709 INIT_WORK(&mgr->up_req_work, drm_dp_mst_up_req_work); 5710 init_waitqueue_head(&mgr->tx_waitq); 5711 mgr->dev = dev; 5712 mgr->aux = aux; 5713 mgr->max_dpcd_transaction_bytes = max_dpcd_transaction_bytes; 5714 mgr->max_payloads = max_payloads; 5715 mgr->conn_base_id = conn_base_id; 5716 5717 mst_state = kzalloc(sizeof(*mst_state), GFP_KERNEL); 5718 if (mst_state == NULL) 5719 return -ENOMEM; 5720 5721 mst_state->total_avail_slots = 63; 5722 mst_state->start_slot = 1; 5723 5724 mst_state->mgr = mgr; 5725 INIT_LIST_HEAD(&mst_state->payloads); 5726 5727 drm_atomic_private_obj_init(dev, &mgr->base, 5728 &mst_state->base, 5729 &drm_dp_mst_topology_state_funcs); 5730 5731 return 0; 5732 } 5733 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_init); 5734 5735 /** 5736 * drm_dp_mst_topology_mgr_destroy() - destroy topology manager. 5737 * @mgr: manager to destroy 5738 */ 5739 void drm_dp_mst_topology_mgr_destroy(struct drm_dp_mst_topology_mgr *mgr) 5740 { 5741 drm_dp_mst_topology_mgr_set_mst(mgr, false); 5742 flush_work(&mgr->work); 5743 /* The following will also drain any requeued work on the WQ. */ 5744 if (mgr->delayed_destroy_wq) { 5745 destroy_workqueue(mgr->delayed_destroy_wq); 5746 mgr->delayed_destroy_wq = NULL; 5747 } 5748 mgr->dev = NULL; 5749 mgr->aux = NULL; 5750 drm_atomic_private_obj_fini(&mgr->base); 5751 mgr->funcs = NULL; 5752 5753 mutex_destroy(&mgr->delayed_destroy_lock); 5754 mutex_destroy(&mgr->qlock); 5755 mutex_destroy(&mgr->lock); 5756 mutex_destroy(&mgr->up_req_lock); 5757 mutex_destroy(&mgr->probe_lock); 5758 #if IS_ENABLED(CONFIG_DRM_DEBUG_DP_MST_TOPOLOGY_REFS) 5759 mutex_destroy(&mgr->topology_ref_history_lock); 5760 #endif 5761 } 5762 EXPORT_SYMBOL(drm_dp_mst_topology_mgr_destroy); 5763 5764 static bool remote_i2c_read_ok(const struct i2c_msg msgs[], int num) 5765 { 5766 int i; 5767 5768 if (num - 1 > DP_REMOTE_I2C_READ_MAX_TRANSACTIONS) 5769 return false; 5770 5771 for (i = 0; i < num - 1; i++) { 5772 if (msgs[i].flags & I2C_M_RD || 5773 msgs[i].len > 0xff) 5774 return false; 5775 } 5776 5777 return msgs[num - 1].flags & I2C_M_RD && 5778 msgs[num - 1].len <= 0xff; 5779 } 5780 5781 static bool remote_i2c_write_ok(const struct i2c_msg msgs[], int num) 5782 { 5783 int i; 5784 5785 for (i = 0; i < num - 1; i++) { 5786 if (msgs[i].flags & I2C_M_RD || !(msgs[i].flags & I2C_M_STOP) || 5787 msgs[i].len > 0xff) 5788 return false; 5789 } 5790 5791 return !(msgs[num - 1].flags & I2C_M_RD) && msgs[num - 1].len <= 0xff; 5792 } 5793 5794 static int drm_dp_mst_i2c_read(struct drm_dp_mst_branch *mstb, 5795 struct drm_dp_mst_port *port, 5796 struct i2c_msg *msgs, int num) 5797 { 5798 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5799 unsigned int i; 5800 struct drm_dp_sideband_msg_req_body msg; 5801 struct drm_dp_sideband_msg_tx *txmsg = NULL; 5802 int ret; 5803 5804 memset(&msg, 0, sizeof(msg)); 5805 msg.req_type = DP_REMOTE_I2C_READ; 5806 msg.u.i2c_read.num_transactions = num - 1; 5807 msg.u.i2c_read.port_number = port->port_num; 5808 for (i = 0; i < num - 1; i++) { 5809 msg.u.i2c_read.transactions[i].i2c_dev_id = msgs[i].addr; 5810 msg.u.i2c_read.transactions[i].num_bytes = msgs[i].len; 5811 msg.u.i2c_read.transactions[i].bytes = msgs[i].buf; 5812 msg.u.i2c_read.transactions[i].no_stop_bit = !(msgs[i].flags & I2C_M_STOP); 5813 } 5814 msg.u.i2c_read.read_i2c_device_id = msgs[num - 1].addr; 5815 msg.u.i2c_read.num_bytes_read = msgs[num - 1].len; 5816 5817 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 5818 if (!txmsg) { 5819 ret = -ENOMEM; 5820 goto out; 5821 } 5822 5823 txmsg->dst = mstb; 5824 drm_dp_encode_sideband_req(&msg, txmsg); 5825 5826 drm_dp_queue_down_tx(mgr, txmsg); 5827 5828 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 5829 if (ret > 0) { 5830 5831 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 5832 ret = -EREMOTEIO; 5833 goto out; 5834 } 5835 if (txmsg->reply.u.remote_i2c_read_ack.num_bytes != msgs[num - 1].len) { 5836 ret = -EIO; 5837 goto out; 5838 } 5839 memcpy(msgs[num - 1].buf, txmsg->reply.u.remote_i2c_read_ack.bytes, msgs[num - 1].len); 5840 ret = num; 5841 } 5842 out: 5843 kfree(txmsg); 5844 return ret; 5845 } 5846 5847 static int drm_dp_mst_i2c_write(struct drm_dp_mst_branch *mstb, 5848 struct drm_dp_mst_port *port, 5849 struct i2c_msg *msgs, int num) 5850 { 5851 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5852 unsigned int i; 5853 struct drm_dp_sideband_msg_req_body msg; 5854 struct drm_dp_sideband_msg_tx *txmsg = NULL; 5855 int ret; 5856 5857 txmsg = kzalloc(sizeof(*txmsg), GFP_KERNEL); 5858 if (!txmsg) { 5859 ret = -ENOMEM; 5860 goto out; 5861 } 5862 for (i = 0; i < num; i++) { 5863 memset(&msg, 0, sizeof(msg)); 5864 msg.req_type = DP_REMOTE_I2C_WRITE; 5865 msg.u.i2c_write.port_number = port->port_num; 5866 msg.u.i2c_write.write_i2c_device_id = msgs[i].addr; 5867 msg.u.i2c_write.num_bytes = msgs[i].len; 5868 msg.u.i2c_write.bytes = msgs[i].buf; 5869 5870 memset(txmsg, 0, sizeof(*txmsg)); 5871 txmsg->dst = mstb; 5872 5873 drm_dp_encode_sideband_req(&msg, txmsg); 5874 drm_dp_queue_down_tx(mgr, txmsg); 5875 5876 ret = drm_dp_mst_wait_tx_reply(mstb, txmsg); 5877 if (ret > 0) { 5878 if (txmsg->reply.reply_type == DP_SIDEBAND_REPLY_NAK) { 5879 ret = -EREMOTEIO; 5880 goto out; 5881 } 5882 } else { 5883 goto out; 5884 } 5885 } 5886 ret = num; 5887 out: 5888 kfree(txmsg); 5889 return ret; 5890 } 5891 5892 /* I2C device */ 5893 static int drm_dp_mst_i2c_xfer(struct i2c_adapter *adapter, 5894 struct i2c_msg *msgs, int num) 5895 { 5896 struct drm_dp_aux *aux = adapter->algo_data; 5897 struct drm_dp_mst_port *port = 5898 container_of(aux, struct drm_dp_mst_port, aux); 5899 struct drm_dp_mst_branch *mstb; 5900 struct drm_dp_mst_topology_mgr *mgr = port->mgr; 5901 int ret; 5902 5903 mstb = drm_dp_mst_topology_get_mstb_validated(mgr, port->parent); 5904 if (!mstb) 5905 return -EREMOTEIO; 5906 5907 if (remote_i2c_read_ok(msgs, num)) { 5908 ret = drm_dp_mst_i2c_read(mstb, port, msgs, num); 5909 } else if (remote_i2c_write_ok(msgs, num)) { 5910 ret = drm_dp_mst_i2c_write(mstb, port, msgs, num); 5911 } else { 5912 drm_dbg_kms(mgr->dev, "Unsupported I2C transaction for MST device\n"); 5913 ret = -EIO; 5914 } 5915 5916 drm_dp_mst_topology_put_mstb(mstb); 5917 return ret; 5918 } 5919 5920 static u32 drm_dp_mst_i2c_functionality(struct i2c_adapter *adapter) 5921 { 5922 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | 5923 I2C_FUNC_SMBUS_READ_BLOCK_DATA | 5924 I2C_FUNC_SMBUS_BLOCK_PROC_CALL | 5925 I2C_FUNC_10BIT_ADDR; 5926 } 5927 5928 static const struct i2c_algorithm drm_dp_mst_i2c_algo = { 5929 .functionality = drm_dp_mst_i2c_functionality, 5930 .master_xfer = drm_dp_mst_i2c_xfer, 5931 }; 5932 5933 /** 5934 * drm_dp_mst_register_i2c_bus() - register an I2C adapter for I2C-over-AUX 5935 * @port: The port to add the I2C bus on 5936 * 5937 * Returns 0 on success or a negative error code on failure. 5938 */ 5939 static int drm_dp_mst_register_i2c_bus(struct drm_dp_mst_port *port) 5940 { 5941 struct drm_dp_aux *aux = &port->aux; 5942 struct device *parent_dev = port->mgr->dev->dev; 5943 5944 aux->ddc.algo = &drm_dp_mst_i2c_algo; 5945 aux->ddc.algo_data = aux; 5946 aux->ddc.retries = 3; 5947 5948 aux->ddc.owner = THIS_MODULE; 5949 /* FIXME: set the kdev of the port's connector as parent */ 5950 aux->ddc.dev.parent = parent_dev; 5951 aux->ddc.dev.of_node = parent_dev->of_node; 5952 5953 strscpy(aux->ddc.name, aux->name ? aux->name : dev_name(parent_dev), 5954 sizeof(aux->ddc.name)); 5955 5956 return i2c_add_adapter(&aux->ddc); 5957 } 5958 5959 /** 5960 * drm_dp_mst_unregister_i2c_bus() - unregister an I2C-over-AUX adapter 5961 * @port: The port to remove the I2C bus from 5962 */ 5963 static void drm_dp_mst_unregister_i2c_bus(struct drm_dp_mst_port *port) 5964 { 5965 i2c_del_adapter(&port->aux.ddc); 5966 } 5967 5968 /** 5969 * drm_dp_mst_is_virtual_dpcd() - Is the given port a virtual DP Peer Device 5970 * @port: The port to check 5971 * 5972 * A single physical MST hub object can be represented in the topology 5973 * by multiple branches, with virtual ports between those branches. 5974 * 5975 * As of DP1.4, An MST hub with internal (virtual) ports must expose 5976 * certain DPCD registers over those ports. See sections 2.6.1.1.1 5977 * and 2.6.1.1.2 of Display Port specification v1.4 for details. 5978 * 5979 * May acquire mgr->lock 5980 * 5981 * Returns: 5982 * true if the port is a virtual DP peer device, false otherwise 5983 */ 5984 static bool drm_dp_mst_is_virtual_dpcd(struct drm_dp_mst_port *port) 5985 { 5986 struct drm_dp_mst_port *downstream_port; 5987 5988 if (!port || port->dpcd_rev < DP_DPCD_REV_14) 5989 return false; 5990 5991 /* Virtual DP Sink (Internal Display Panel) */ 5992 if (drm_dp_mst_port_is_logical(port)) 5993 return true; 5994 5995 /* DP-to-HDMI Protocol Converter */ 5996 if (port->pdt == DP_PEER_DEVICE_DP_LEGACY_CONV && 5997 !port->mcs && 5998 port->ldps) 5999 return true; 6000 6001 /* DP-to-DP */ 6002 mutex_lock(&port->mgr->lock); 6003 if (port->pdt == DP_PEER_DEVICE_MST_BRANCHING && 6004 port->mstb && 6005 port->mstb->num_ports == 2) { 6006 list_for_each_entry(downstream_port, &port->mstb->ports, next) { 6007 if (downstream_port->pdt == DP_PEER_DEVICE_SST_SINK && 6008 !downstream_port->input) { 6009 mutex_unlock(&port->mgr->lock); 6010 return true; 6011 } 6012 } 6013 } 6014 mutex_unlock(&port->mgr->lock); 6015 6016 return false; 6017 } 6018 6019 /** 6020 * drm_dp_mst_aux_for_parent() - Get the AUX device for an MST port's parent 6021 * @port: MST port whose parent's AUX device is returned 6022 * 6023 * Return the AUX device for @port's parent or NULL if port's parent is the 6024 * root port. 6025 */ 6026 struct drm_dp_aux *drm_dp_mst_aux_for_parent(struct drm_dp_mst_port *port) 6027 { 6028 if (!port->parent || !port->parent->port_parent) 6029 return NULL; 6030 6031 return &port->parent->port_parent->aux; 6032 } 6033 EXPORT_SYMBOL(drm_dp_mst_aux_for_parent); 6034 6035 /** 6036 * drm_dp_mst_dsc_aux_for_port() - Find the correct aux for DSC 6037 * @port: The port to check. A leaf of the MST tree with an attached display. 6038 * 6039 * Depending on the situation, DSC may be enabled via the endpoint aux, 6040 * the immediately upstream aux, or the connector's physical aux. 6041 * 6042 * This is both the correct aux to read DSC_CAPABILITY and the 6043 * correct aux to write DSC_ENABLED. 6044 * 6045 * This operation can be expensive (up to four aux reads), so 6046 * the caller should cache the return. 6047 * 6048 * Returns: 6049 * NULL if DSC cannot be enabled on this port, otherwise the aux device 6050 */ 6051 struct drm_dp_aux *drm_dp_mst_dsc_aux_for_port(struct drm_dp_mst_port *port) 6052 { 6053 struct drm_dp_mst_port *immediate_upstream_port; 6054 struct drm_dp_aux *immediate_upstream_aux; 6055 struct drm_dp_mst_port *fec_port; 6056 struct drm_dp_desc desc = {}; 6057 u8 endpoint_fec; 6058 u8 endpoint_dsc; 6059 6060 if (!port) 6061 return NULL; 6062 6063 if (port->parent->port_parent) 6064 immediate_upstream_port = port->parent->port_parent; 6065 else 6066 immediate_upstream_port = NULL; 6067 6068 fec_port = immediate_upstream_port; 6069 while (fec_port) { 6070 /* 6071 * Each physical link (i.e. not a virtual port) between the 6072 * output and the primary device must support FEC 6073 */ 6074 if (!drm_dp_mst_is_virtual_dpcd(fec_port) && 6075 !fec_port->fec_capable) 6076 return NULL; 6077 6078 fec_port = fec_port->parent->port_parent; 6079 } 6080 6081 /* DP-to-DP peer device */ 6082 if (drm_dp_mst_is_virtual_dpcd(immediate_upstream_port)) { 6083 u8 upstream_dsc; 6084 6085 if (drm_dp_dpcd_read(&port->aux, 6086 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1) 6087 return NULL; 6088 if (drm_dp_dpcd_read(&port->aux, 6089 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1) 6090 return NULL; 6091 if (drm_dp_dpcd_read(&immediate_upstream_port->aux, 6092 DP_DSC_SUPPORT, &upstream_dsc, 1) != 1) 6093 return NULL; 6094 6095 /* Enpoint decompression with DP-to-DP peer device */ 6096 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) && 6097 (endpoint_fec & DP_FEC_CAPABLE) && 6098 (upstream_dsc & DP_DSC_PASSTHROUGH_IS_SUPPORTED)) { 6099 port->passthrough_aux = &immediate_upstream_port->aux; 6100 return &port->aux; 6101 } 6102 6103 /* Virtual DPCD decompression with DP-to-DP peer device */ 6104 return &immediate_upstream_port->aux; 6105 } 6106 6107 /* Virtual DPCD decompression with DP-to-HDMI or Virtual DP Sink */ 6108 if (drm_dp_mst_is_virtual_dpcd(port)) 6109 return &port->aux; 6110 6111 /* 6112 * Synaptics quirk 6113 * Applies to ports for which: 6114 * - Physical aux has Synaptics OUI 6115 * - DPv1.4 or higher 6116 * - Port is on primary branch device 6117 * - Not a VGA adapter (DP_DWN_STRM_PORT_TYPE_ANALOG) 6118 */ 6119 if (immediate_upstream_port) 6120 immediate_upstream_aux = &immediate_upstream_port->aux; 6121 else 6122 immediate_upstream_aux = port->mgr->aux; 6123 6124 if (drm_dp_read_desc(immediate_upstream_aux, &desc, true)) 6125 return NULL; 6126 6127 if (drm_dp_has_quirk(&desc, DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD)) { 6128 u8 dpcd_ext[DP_RECEIVER_CAP_SIZE]; 6129 6130 if (drm_dp_read_dpcd_caps(immediate_upstream_aux, dpcd_ext) < 0) 6131 return NULL; 6132 6133 if (dpcd_ext[DP_DPCD_REV] >= DP_DPCD_REV_14 && 6134 ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_PRESENT) && 6135 ((dpcd_ext[DP_DOWNSTREAMPORT_PRESENT] & DP_DWN_STRM_PORT_TYPE_MASK) 6136 != DP_DWN_STRM_PORT_TYPE_ANALOG))) 6137 return immediate_upstream_aux; 6138 } 6139 6140 /* 6141 * The check below verifies if the MST sink 6142 * connected to the GPU is capable of DSC - 6143 * therefore the endpoint needs to be 6144 * both DSC and FEC capable. 6145 */ 6146 if (drm_dp_dpcd_read(&port->aux, 6147 DP_DSC_SUPPORT, &endpoint_dsc, 1) != 1) 6148 return NULL; 6149 if (drm_dp_dpcd_read(&port->aux, 6150 DP_FEC_CAPABILITY, &endpoint_fec, 1) != 1) 6151 return NULL; 6152 if ((endpoint_dsc & DP_DSC_DECOMPRESSION_IS_SUPPORTED) && 6153 (endpoint_fec & DP_FEC_CAPABLE)) 6154 return &port->aux; 6155 6156 return NULL; 6157 } 6158 EXPORT_SYMBOL(drm_dp_mst_dsc_aux_for_port); 6159