1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Thunderbolt driver - eeprom access 4 * 5 * Copyright (c) 2014 Andreas Noever <andreas.noever@gmail.com> 6 * Copyright (C) 2018, Intel Corporation 7 */ 8 9 #include <linux/crc32.h> 10 #include <linux/delay.h> 11 #include <linux/property.h> 12 #include <linux/slab.h> 13 #include "tb.h" 14 15 /* 16 * tb_eeprom_ctl_write() - write control word 17 */ 18 static int tb_eeprom_ctl_write(struct tb_switch *sw, struct tb_eeprom_ctl *ctl) 19 { 20 return tb_sw_write(sw, ctl, TB_CFG_SWITCH, sw->cap_plug_events + 4, 1); 21 } 22 23 /* 24 * tb_eeprom_ctl_write() - read control word 25 */ 26 static int tb_eeprom_ctl_read(struct tb_switch *sw, struct tb_eeprom_ctl *ctl) 27 { 28 return tb_sw_read(sw, ctl, TB_CFG_SWITCH, sw->cap_plug_events + 4, 1); 29 } 30 31 enum tb_eeprom_transfer { 32 TB_EEPROM_IN, 33 TB_EEPROM_OUT, 34 }; 35 36 /* 37 * tb_eeprom_active - enable rom access 38 * 39 * WARNING: Always disable access after usage. Otherwise the controller will 40 * fail to reprobe. 41 */ 42 static int tb_eeprom_active(struct tb_switch *sw, bool enable) 43 { 44 struct tb_eeprom_ctl ctl; 45 int res = tb_eeprom_ctl_read(sw, &ctl); 46 if (res) 47 return res; 48 if (enable) { 49 ctl.access_high = 1; 50 res = tb_eeprom_ctl_write(sw, &ctl); 51 if (res) 52 return res; 53 ctl.access_low = 0; 54 return tb_eeprom_ctl_write(sw, &ctl); 55 } else { 56 ctl.access_low = 1; 57 res = tb_eeprom_ctl_write(sw, &ctl); 58 if (res) 59 return res; 60 ctl.access_high = 0; 61 return tb_eeprom_ctl_write(sw, &ctl); 62 } 63 } 64 65 /* 66 * tb_eeprom_transfer - transfer one bit 67 * 68 * If TB_EEPROM_IN is passed, then the bit can be retrieved from ctl->data_in. 69 * If TB_EEPROM_OUT is passed, then ctl->data_out will be written. 70 */ 71 static int tb_eeprom_transfer(struct tb_switch *sw, struct tb_eeprom_ctl *ctl, 72 enum tb_eeprom_transfer direction) 73 { 74 int res; 75 if (direction == TB_EEPROM_OUT) { 76 res = tb_eeprom_ctl_write(sw, ctl); 77 if (res) 78 return res; 79 } 80 ctl->clock = 1; 81 res = tb_eeprom_ctl_write(sw, ctl); 82 if (res) 83 return res; 84 if (direction == TB_EEPROM_IN) { 85 res = tb_eeprom_ctl_read(sw, ctl); 86 if (res) 87 return res; 88 } 89 ctl->clock = 0; 90 return tb_eeprom_ctl_write(sw, ctl); 91 } 92 93 /* 94 * tb_eeprom_out - write one byte to the bus 95 */ 96 static int tb_eeprom_out(struct tb_switch *sw, u8 val) 97 { 98 struct tb_eeprom_ctl ctl; 99 int i; 100 int res = tb_eeprom_ctl_read(sw, &ctl); 101 if (res) 102 return res; 103 for (i = 0; i < 8; i++) { 104 ctl.data_out = val & 0x80; 105 res = tb_eeprom_transfer(sw, &ctl, TB_EEPROM_OUT); 106 if (res) 107 return res; 108 val <<= 1; 109 } 110 return 0; 111 } 112 113 /* 114 * tb_eeprom_in - read one byte from the bus 115 */ 116 static int tb_eeprom_in(struct tb_switch *sw, u8 *val) 117 { 118 struct tb_eeprom_ctl ctl; 119 int i; 120 int res = tb_eeprom_ctl_read(sw, &ctl); 121 if (res) 122 return res; 123 *val = 0; 124 for (i = 0; i < 8; i++) { 125 *val <<= 1; 126 res = tb_eeprom_transfer(sw, &ctl, TB_EEPROM_IN); 127 if (res) 128 return res; 129 *val |= ctl.data_in; 130 } 131 return 0; 132 } 133 134 /* 135 * tb_eeprom_get_drom_offset - get drom offset within eeprom 136 */ 137 static int tb_eeprom_get_drom_offset(struct tb_switch *sw, u16 *offset) 138 { 139 struct tb_cap_plug_events cap; 140 int res; 141 142 if (!sw->cap_plug_events) { 143 tb_sw_warn(sw, "no TB_CAP_PLUG_EVENTS, cannot read eeprom\n"); 144 return -ENODEV; 145 } 146 res = tb_sw_read(sw, &cap, TB_CFG_SWITCH, sw->cap_plug_events, 147 sizeof(cap) / 4); 148 if (res) 149 return res; 150 151 if (!cap.eeprom_ctl.present || cap.eeprom_ctl.not_present) { 152 tb_sw_warn(sw, "no NVM\n"); 153 return -ENODEV; 154 } 155 156 if (cap.drom_offset > 0xffff) { 157 tb_sw_warn(sw, "drom offset is larger than 0xffff: %#x\n", 158 cap.drom_offset); 159 return -ENXIO; 160 } 161 *offset = cap.drom_offset; 162 return 0; 163 } 164 165 /* 166 * tb_eeprom_read_n - read count bytes from offset into val 167 */ 168 static int tb_eeprom_read_n(struct tb_switch *sw, u16 offset, u8 *val, 169 size_t count) 170 { 171 u16 drom_offset; 172 int i, res; 173 174 res = tb_eeprom_get_drom_offset(sw, &drom_offset); 175 if (res) 176 return res; 177 178 offset += drom_offset; 179 180 res = tb_eeprom_active(sw, true); 181 if (res) 182 return res; 183 res = tb_eeprom_out(sw, 3); 184 if (res) 185 return res; 186 res = tb_eeprom_out(sw, offset >> 8); 187 if (res) 188 return res; 189 res = tb_eeprom_out(sw, offset); 190 if (res) 191 return res; 192 for (i = 0; i < count; i++) { 193 res = tb_eeprom_in(sw, val + i); 194 if (res) 195 return res; 196 } 197 return tb_eeprom_active(sw, false); 198 } 199 200 static u8 tb_crc8(u8 *data, int len) 201 { 202 int i, j; 203 u8 val = 0xff; 204 for (i = 0; i < len; i++) { 205 val ^= data[i]; 206 for (j = 0; j < 8; j++) 207 val = (val << 1) ^ ((val & 0x80) ? 7 : 0); 208 } 209 return val; 210 } 211 212 static u32 tb_crc32(void *data, size_t len) 213 { 214 return ~__crc32c_le(~0, data, len); 215 } 216 217 #define TB_DROM_DATA_START 13 218 struct tb_drom_header { 219 /* BYTE 0 */ 220 u8 uid_crc8; /* checksum for uid */ 221 /* BYTES 1-8 */ 222 u64 uid; 223 /* BYTES 9-12 */ 224 u32 data_crc32; /* checksum for data_len bytes starting at byte 13 */ 225 /* BYTE 13 */ 226 u8 device_rom_revision; /* should be <= 1 */ 227 u16 data_len:10; 228 u8 __unknown1:6; 229 /* BYTES 16-21 */ 230 u16 vendor_id; 231 u16 model_id; 232 u8 model_rev; 233 u8 eeprom_rev; 234 } __packed; 235 236 enum tb_drom_entry_type { 237 /* force unsigned to prevent "one-bit signed bitfield" warning */ 238 TB_DROM_ENTRY_GENERIC = 0U, 239 TB_DROM_ENTRY_PORT, 240 }; 241 242 struct tb_drom_entry_header { 243 u8 len; 244 u8 index:6; 245 bool port_disabled:1; /* only valid if type is TB_DROM_ENTRY_PORT */ 246 enum tb_drom_entry_type type:1; 247 } __packed; 248 249 struct tb_drom_entry_generic { 250 struct tb_drom_entry_header header; 251 u8 data[]; 252 } __packed; 253 254 struct tb_drom_entry_port { 255 /* BYTES 0-1 */ 256 struct tb_drom_entry_header header; 257 /* BYTE 2 */ 258 u8 dual_link_port_rid:4; 259 u8 link_nr:1; 260 u8 unknown1:2; 261 bool has_dual_link_port:1; 262 263 /* BYTE 3 */ 264 u8 dual_link_port_nr:6; 265 u8 unknown2:2; 266 267 /* BYTES 4 - 5 TODO decode */ 268 u8 micro2:4; 269 u8 micro1:4; 270 u8 micro3; 271 272 /* BYTES 6-7, TODO: verify (find hardware that has these set) */ 273 u8 peer_port_rid:4; 274 u8 unknown3:3; 275 bool has_peer_port:1; 276 u8 peer_port_nr:6; 277 u8 unknown4:2; 278 } __packed; 279 280 281 /** 282 * tb_drom_read_uid_only() - Read UID directly from DROM 283 * @sw: Router whose UID to read 284 * @uid: UID is placed here 285 * 286 * Does not use the cached copy in sw->drom. Used during resume to check switch 287 * identity. 288 */ 289 int tb_drom_read_uid_only(struct tb_switch *sw, u64 *uid) 290 { 291 u8 data[9]; 292 u8 crc; 293 int res; 294 295 /* read uid */ 296 res = tb_eeprom_read_n(sw, 0, data, 9); 297 if (res) 298 return res; 299 300 crc = tb_crc8(data + 1, 8); 301 if (crc != data[0]) { 302 tb_sw_warn(sw, "uid crc8 mismatch (expected: %#x, got: %#x)\n", 303 data[0], crc); 304 return -EIO; 305 } 306 307 *uid = *(u64 *)(data+1); 308 return 0; 309 } 310 311 static int tb_drom_parse_entry_generic(struct tb_switch *sw, 312 struct tb_drom_entry_header *header) 313 { 314 const struct tb_drom_entry_generic *entry = 315 (const struct tb_drom_entry_generic *)header; 316 317 switch (header->index) { 318 case 1: 319 /* Length includes 2 bytes header so remove it before copy */ 320 sw->vendor_name = kstrndup(entry->data, 321 header->len - sizeof(*header), GFP_KERNEL); 322 if (!sw->vendor_name) 323 return -ENOMEM; 324 break; 325 326 case 2: 327 sw->device_name = kstrndup(entry->data, 328 header->len - sizeof(*header), GFP_KERNEL); 329 if (!sw->device_name) 330 return -ENOMEM; 331 break; 332 } 333 334 return 0; 335 } 336 337 static int tb_drom_parse_entry_port(struct tb_switch *sw, 338 struct tb_drom_entry_header *header) 339 { 340 struct tb_port *port; 341 int res; 342 enum tb_port_type type; 343 344 /* 345 * Some DROMs list more ports than the controller actually has 346 * so we skip those but allow the parser to continue. 347 */ 348 if (header->index > sw->config.max_port_number) { 349 dev_info_once(&sw->dev, "ignoring unnecessary extra entries in DROM\n"); 350 return 0; 351 } 352 353 port = &sw->ports[header->index]; 354 port->disabled = header->port_disabled; 355 if (port->disabled) 356 return 0; 357 358 res = tb_port_read(port, &type, TB_CFG_PORT, 2, 1); 359 if (res) 360 return res; 361 type &= 0xffffff; 362 363 if (type == TB_TYPE_PORT) { 364 struct tb_drom_entry_port *entry = (void *) header; 365 if (header->len != sizeof(*entry)) { 366 tb_sw_warn(sw, 367 "port entry has size %#x (expected %#zx)\n", 368 header->len, sizeof(struct tb_drom_entry_port)); 369 return -EIO; 370 } 371 port->link_nr = entry->link_nr; 372 if (entry->has_dual_link_port) 373 port->dual_link_port = 374 &port->sw->ports[entry->dual_link_port_nr]; 375 } 376 return 0; 377 } 378 379 /* 380 * tb_drom_parse_entries - parse the linked list of drom entries 381 * 382 * Drom must have been copied to sw->drom. 383 */ 384 static int tb_drom_parse_entries(struct tb_switch *sw) 385 { 386 struct tb_drom_header *header = (void *) sw->drom; 387 u16 pos = sizeof(*header); 388 u16 drom_size = header->data_len + TB_DROM_DATA_START; 389 int res; 390 391 while (pos < drom_size) { 392 struct tb_drom_entry_header *entry = (void *) (sw->drom + pos); 393 if (pos + 1 == drom_size || pos + entry->len > drom_size 394 || !entry->len) { 395 tb_sw_warn(sw, "DROM buffer overrun\n"); 396 return -EILSEQ; 397 } 398 399 switch (entry->type) { 400 case TB_DROM_ENTRY_GENERIC: 401 res = tb_drom_parse_entry_generic(sw, entry); 402 break; 403 case TB_DROM_ENTRY_PORT: 404 res = tb_drom_parse_entry_port(sw, entry); 405 break; 406 } 407 if (res) 408 return res; 409 410 pos += entry->len; 411 } 412 return 0; 413 } 414 415 /* 416 * tb_drom_copy_efi - copy drom supplied by EFI to sw->drom if present 417 */ 418 static int tb_drom_copy_efi(struct tb_switch *sw, u16 *size) 419 { 420 struct device *dev = &sw->tb->nhi->pdev->dev; 421 int len, res; 422 423 len = device_property_count_u8(dev, "ThunderboltDROM"); 424 if (len < 0 || len < sizeof(struct tb_drom_header)) 425 return -EINVAL; 426 427 sw->drom = kmalloc(len, GFP_KERNEL); 428 if (!sw->drom) 429 return -ENOMEM; 430 431 res = device_property_read_u8_array(dev, "ThunderboltDROM", sw->drom, 432 len); 433 if (res) 434 goto err; 435 436 *size = ((struct tb_drom_header *)sw->drom)->data_len + 437 TB_DROM_DATA_START; 438 if (*size > len) 439 goto err; 440 441 return 0; 442 443 err: 444 kfree(sw->drom); 445 sw->drom = NULL; 446 return -EINVAL; 447 } 448 449 static int tb_drom_copy_nvm(struct tb_switch *sw, u16 *size) 450 { 451 u32 drom_offset; 452 int ret; 453 454 if (!sw->dma_port) 455 return -ENODEV; 456 457 ret = tb_sw_read(sw, &drom_offset, TB_CFG_SWITCH, 458 sw->cap_plug_events + 12, 1); 459 if (ret) 460 return ret; 461 462 if (!drom_offset) 463 return -ENODEV; 464 465 ret = dma_port_flash_read(sw->dma_port, drom_offset + 14, size, 466 sizeof(*size)); 467 if (ret) 468 return ret; 469 470 /* Size includes CRC8 + UID + CRC32 */ 471 *size += 1 + 8 + 4; 472 sw->drom = kzalloc(*size, GFP_KERNEL); 473 if (!sw->drom) 474 return -ENOMEM; 475 476 ret = dma_port_flash_read(sw->dma_port, drom_offset, sw->drom, *size); 477 if (ret) 478 goto err_free; 479 480 /* 481 * Read UID from the minimal DROM because the one in NVM is just 482 * a placeholder. 483 */ 484 tb_drom_read_uid_only(sw, &sw->uid); 485 return 0; 486 487 err_free: 488 kfree(sw->drom); 489 sw->drom = NULL; 490 return ret; 491 } 492 493 static int usb4_copy_host_drom(struct tb_switch *sw, u16 *size) 494 { 495 int ret; 496 497 ret = usb4_switch_drom_read(sw, 14, size, sizeof(*size)); 498 if (ret) 499 return ret; 500 501 /* Size includes CRC8 + UID + CRC32 */ 502 *size += 1 + 8 + 4; 503 sw->drom = kzalloc(*size, GFP_KERNEL); 504 if (!sw->drom) 505 return -ENOMEM; 506 507 ret = usb4_switch_drom_read(sw, 0, sw->drom, *size); 508 if (ret) { 509 kfree(sw->drom); 510 sw->drom = NULL; 511 } 512 513 return ret; 514 } 515 516 static int tb_drom_read_n(struct tb_switch *sw, u16 offset, u8 *val, 517 size_t count) 518 { 519 if (tb_switch_is_usb4(sw)) 520 return usb4_switch_drom_read(sw, offset, val, count); 521 return tb_eeprom_read_n(sw, offset, val, count); 522 } 523 524 /** 525 * tb_drom_read() - Copy DROM to sw->drom and parse it 526 * @sw: Router whose DROM to read and parse 527 * 528 * This function reads router DROM and if successful parses the entries and 529 * populates the fields in @sw accordingly. Can be called for any router 530 * generation. 531 * 532 * Returns %0 in case of success and negative errno otherwise. 533 */ 534 int tb_drom_read(struct tb_switch *sw) 535 { 536 u16 size; 537 u32 crc; 538 struct tb_drom_header *header; 539 int res, retries = 1; 540 541 if (sw->drom) 542 return 0; 543 544 if (tb_route(sw) == 0) { 545 /* 546 * Apple's NHI EFI driver supplies a DROM for the root switch 547 * in a device property. Use it if available. 548 */ 549 if (tb_drom_copy_efi(sw, &size) == 0) 550 goto parse; 551 552 /* Non-Apple hardware has the DROM as part of NVM */ 553 if (tb_drom_copy_nvm(sw, &size) == 0) 554 goto parse; 555 556 /* 557 * USB4 hosts may support reading DROM through router 558 * operations. 559 */ 560 if (tb_switch_is_usb4(sw)) { 561 usb4_switch_read_uid(sw, &sw->uid); 562 if (!usb4_copy_host_drom(sw, &size)) 563 goto parse; 564 } else { 565 /* 566 * The root switch contains only a dummy drom 567 * (header only, no entries). Hardcode the 568 * configuration here. 569 */ 570 tb_drom_read_uid_only(sw, &sw->uid); 571 } 572 573 return 0; 574 } 575 576 res = tb_drom_read_n(sw, 14, (u8 *) &size, 2); 577 if (res) 578 return res; 579 size &= 0x3ff; 580 size += TB_DROM_DATA_START; 581 tb_sw_dbg(sw, "reading drom (length: %#x)\n", size); 582 if (size < sizeof(*header)) { 583 tb_sw_warn(sw, "drom too small, aborting\n"); 584 return -EIO; 585 } 586 587 sw->drom = kzalloc(size, GFP_KERNEL); 588 if (!sw->drom) 589 return -ENOMEM; 590 res = tb_drom_read_n(sw, 0, sw->drom, size); 591 if (res) 592 goto err; 593 594 parse: 595 header = (void *) sw->drom; 596 597 if (header->data_len + TB_DROM_DATA_START != size) { 598 tb_sw_warn(sw, "drom size mismatch, aborting\n"); 599 goto err; 600 } 601 602 crc = tb_crc8((u8 *) &header->uid, 8); 603 if (crc != header->uid_crc8) { 604 tb_sw_warn(sw, 605 "drom uid crc8 mismatch (expected: %#x, got: %#x), aborting\n", 606 header->uid_crc8, crc); 607 goto err; 608 } 609 if (!sw->uid) 610 sw->uid = header->uid; 611 sw->vendor = header->vendor_id; 612 sw->device = header->model_id; 613 tb_check_quirks(sw); 614 615 crc = tb_crc32(sw->drom + TB_DROM_DATA_START, header->data_len); 616 if (crc != header->data_crc32) { 617 tb_sw_warn(sw, 618 "drom data crc32 mismatch (expected: %#x, got: %#x), continuing\n", 619 header->data_crc32, crc); 620 } 621 622 if (header->device_rom_revision > 2) 623 tb_sw_warn(sw, "drom device_rom_revision %#x unknown\n", 624 header->device_rom_revision); 625 626 res = tb_drom_parse_entries(sw); 627 /* If the DROM parsing fails, wait a moment and retry once */ 628 if (res == -EILSEQ && retries--) { 629 tb_sw_warn(sw, "parsing DROM failed, retrying\n"); 630 msleep(100); 631 res = tb_drom_read_n(sw, 0, sw->drom, size); 632 if (!res) 633 goto parse; 634 } 635 636 return res; 637 err: 638 kfree(sw->drom); 639 sw->drom = NULL; 640 return -EIO; 641 642 } 643