1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * PCI VPD support 4 * 5 * Copyright (C) 2010 Broadcom Corporation. 6 */ 7 8 #include <linux/pci.h> 9 #include <linux/delay.h> 10 #include <linux/export.h> 11 #include <linux/sched/signal.h> 12 #include <asm/unaligned.h> 13 #include "pci.h" 14 15 #define PCI_VPD_LRDT_TAG_SIZE 3 16 #define PCI_VPD_SRDT_LEN_MASK 0x07 17 #define PCI_VPD_SRDT_TAG_SIZE 1 18 #define PCI_VPD_STIN_END 0x0f 19 #define PCI_VPD_INFO_FLD_HDR_SIZE 3 20 21 static u16 pci_vpd_lrdt_size(const u8 *lrdt) 22 { 23 return get_unaligned_le16(lrdt + 1); 24 } 25 26 static u8 pci_vpd_srdt_tag(const u8 *srdt) 27 { 28 return *srdt >> 3; 29 } 30 31 static u8 pci_vpd_srdt_size(const u8 *srdt) 32 { 33 return *srdt & PCI_VPD_SRDT_LEN_MASK; 34 } 35 36 static u8 pci_vpd_info_field_size(const u8 *info_field) 37 { 38 return info_field[2]; 39 } 40 41 /* VPD access through PCI 2.2+ VPD capability */ 42 43 static struct pci_dev *pci_get_func0_dev(struct pci_dev *dev) 44 { 45 return pci_get_slot(dev->bus, PCI_DEVFN(PCI_SLOT(dev->devfn), 0)); 46 } 47 48 #define PCI_VPD_MAX_SIZE (PCI_VPD_ADDR_MASK + 1) 49 #define PCI_VPD_SZ_INVALID UINT_MAX 50 51 /** 52 * pci_vpd_size - determine actual size of Vital Product Data 53 * @dev: pci device struct 54 */ 55 static size_t pci_vpd_size(struct pci_dev *dev) 56 { 57 size_t off = 0, size; 58 unsigned char tag, header[1+2]; /* 1 byte tag, 2 bytes length */ 59 60 while (pci_read_vpd_any(dev, off, 1, header) == 1) { 61 size = 0; 62 63 if (off == 0 && (header[0] == 0x00 || header[0] == 0xff)) 64 goto error; 65 66 if (header[0] & PCI_VPD_LRDT) { 67 /* Large Resource Data Type Tag */ 68 if (pci_read_vpd_any(dev, off + 1, 2, &header[1]) != 2) { 69 pci_warn(dev, "failed VPD read at offset %zu\n", 70 off + 1); 71 return off ?: PCI_VPD_SZ_INVALID; 72 } 73 size = pci_vpd_lrdt_size(header); 74 if (off + size > PCI_VPD_MAX_SIZE) 75 goto error; 76 77 off += PCI_VPD_LRDT_TAG_SIZE + size; 78 } else { 79 /* Short Resource Data Type Tag */ 80 tag = pci_vpd_srdt_tag(header); 81 size = pci_vpd_srdt_size(header); 82 if (off + size > PCI_VPD_MAX_SIZE) 83 goto error; 84 85 off += PCI_VPD_SRDT_TAG_SIZE + size; 86 if (tag == PCI_VPD_STIN_END) /* End tag descriptor */ 87 return off; 88 } 89 } 90 return off; 91 92 error: 93 pci_info(dev, "invalid VPD tag %#04x (size %zu) at offset %zu%s\n", 94 header[0], size, off, off == 0 ? 95 "; assume missing optional EEPROM" : ""); 96 return off ?: PCI_VPD_SZ_INVALID; 97 } 98 99 static bool pci_vpd_available(struct pci_dev *dev, bool check_size) 100 { 101 struct pci_vpd *vpd = &dev->vpd; 102 103 if (!vpd->cap) 104 return false; 105 106 if (vpd->len == 0 && check_size) { 107 vpd->len = pci_vpd_size(dev); 108 if (vpd->len == PCI_VPD_SZ_INVALID) { 109 vpd->cap = 0; 110 return false; 111 } 112 } 113 114 return true; 115 } 116 117 /* 118 * Wait for last operation to complete. 119 * This code has to spin since there is no other notification from the PCI 120 * hardware. Since the VPD is often implemented by serial attachment to an 121 * EEPROM, it may take many milliseconds to complete. 122 * @set: if true wait for flag to be set, else wait for it to be cleared 123 * 124 * Returns 0 on success, negative values indicate error. 125 */ 126 static int pci_vpd_wait(struct pci_dev *dev, bool set) 127 { 128 struct pci_vpd *vpd = &dev->vpd; 129 unsigned long timeout = jiffies + msecs_to_jiffies(125); 130 unsigned long max_sleep = 16; 131 u16 status; 132 int ret; 133 134 do { 135 ret = pci_user_read_config_word(dev, vpd->cap + PCI_VPD_ADDR, 136 &status); 137 if (ret < 0) 138 return ret; 139 140 if (!!(status & PCI_VPD_ADDR_F) == set) 141 return 0; 142 143 if (time_after(jiffies, timeout)) 144 break; 145 146 usleep_range(10, max_sleep); 147 if (max_sleep < 1024) 148 max_sleep *= 2; 149 } while (true); 150 151 pci_warn(dev, "VPD access failed. This is likely a firmware bug on this device. Contact the card vendor for a firmware update\n"); 152 return -ETIMEDOUT; 153 } 154 155 static ssize_t pci_vpd_read(struct pci_dev *dev, loff_t pos, size_t count, 156 void *arg, bool check_size) 157 { 158 struct pci_vpd *vpd = &dev->vpd; 159 unsigned int max_len; 160 int ret = 0; 161 loff_t end = pos + count; 162 u8 *buf = arg; 163 164 if (!pci_vpd_available(dev, check_size)) 165 return -ENODEV; 166 167 if (pos < 0) 168 return -EINVAL; 169 170 max_len = check_size ? vpd->len : PCI_VPD_MAX_SIZE; 171 172 if (pos >= max_len) 173 return 0; 174 175 if (end > max_len) { 176 end = max_len; 177 count = end - pos; 178 } 179 180 if (mutex_lock_killable(&vpd->lock)) 181 return -EINTR; 182 183 while (pos < end) { 184 u32 val; 185 unsigned int i, skip; 186 187 if (fatal_signal_pending(current)) { 188 ret = -EINTR; 189 break; 190 } 191 192 ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR, 193 pos & ~3); 194 if (ret < 0) 195 break; 196 ret = pci_vpd_wait(dev, true); 197 if (ret < 0) 198 break; 199 200 ret = pci_user_read_config_dword(dev, vpd->cap + PCI_VPD_DATA, &val); 201 if (ret < 0) 202 break; 203 204 skip = pos & 3; 205 for (i = 0; i < sizeof(u32); i++) { 206 if (i >= skip) { 207 *buf++ = val; 208 if (++pos == end) 209 break; 210 } 211 val >>= 8; 212 } 213 } 214 215 mutex_unlock(&vpd->lock); 216 return ret ? ret : count; 217 } 218 219 static ssize_t pci_vpd_write(struct pci_dev *dev, loff_t pos, size_t count, 220 const void *arg, bool check_size) 221 { 222 struct pci_vpd *vpd = &dev->vpd; 223 unsigned int max_len; 224 const u8 *buf = arg; 225 loff_t end = pos + count; 226 int ret = 0; 227 228 if (!pci_vpd_available(dev, check_size)) 229 return -ENODEV; 230 231 if (pos < 0 || (pos & 3) || (count & 3)) 232 return -EINVAL; 233 234 max_len = check_size ? vpd->len : PCI_VPD_MAX_SIZE; 235 236 if (end > max_len) 237 return -EINVAL; 238 239 if (mutex_lock_killable(&vpd->lock)) 240 return -EINTR; 241 242 while (pos < end) { 243 ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA, 244 get_unaligned_le32(buf)); 245 if (ret < 0) 246 break; 247 ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR, 248 pos | PCI_VPD_ADDR_F); 249 if (ret < 0) 250 break; 251 252 ret = pci_vpd_wait(dev, false); 253 if (ret < 0) 254 break; 255 256 buf += sizeof(u32); 257 pos += sizeof(u32); 258 } 259 260 mutex_unlock(&vpd->lock); 261 return ret ? ret : count; 262 } 263 264 void pci_vpd_init(struct pci_dev *dev) 265 { 266 if (dev->vpd.len == PCI_VPD_SZ_INVALID) 267 return; 268 269 dev->vpd.cap = pci_find_capability(dev, PCI_CAP_ID_VPD); 270 mutex_init(&dev->vpd.lock); 271 } 272 273 static ssize_t vpd_read(struct file *filp, struct kobject *kobj, 274 struct bin_attribute *bin_attr, char *buf, loff_t off, 275 size_t count) 276 { 277 struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj)); 278 struct pci_dev *vpd_dev = dev; 279 ssize_t ret; 280 281 if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) { 282 vpd_dev = pci_get_func0_dev(dev); 283 if (!vpd_dev) 284 return -ENODEV; 285 } 286 287 pci_config_pm_runtime_get(vpd_dev); 288 ret = pci_read_vpd(vpd_dev, off, count, buf); 289 pci_config_pm_runtime_put(vpd_dev); 290 291 if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) 292 pci_dev_put(vpd_dev); 293 294 return ret; 295 } 296 297 static ssize_t vpd_write(struct file *filp, struct kobject *kobj, 298 struct bin_attribute *bin_attr, char *buf, loff_t off, 299 size_t count) 300 { 301 struct pci_dev *dev = to_pci_dev(kobj_to_dev(kobj)); 302 struct pci_dev *vpd_dev = dev; 303 ssize_t ret; 304 305 if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) { 306 vpd_dev = pci_get_func0_dev(dev); 307 if (!vpd_dev) 308 return -ENODEV; 309 } 310 311 pci_config_pm_runtime_get(vpd_dev); 312 ret = pci_write_vpd(vpd_dev, off, count, buf); 313 pci_config_pm_runtime_put(vpd_dev); 314 315 if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) 316 pci_dev_put(vpd_dev); 317 318 return ret; 319 } 320 static BIN_ATTR(vpd, 0600, vpd_read, vpd_write, 0); 321 322 static struct bin_attribute *vpd_attrs[] = { 323 &bin_attr_vpd, 324 NULL, 325 }; 326 327 static umode_t vpd_attr_is_visible(struct kobject *kobj, 328 struct bin_attribute *a, int n) 329 { 330 struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj)); 331 332 if (!pdev->vpd.cap) 333 return 0; 334 335 return a->attr.mode; 336 } 337 338 const struct attribute_group pci_dev_vpd_attr_group = { 339 .bin_attrs = vpd_attrs, 340 .is_bin_visible = vpd_attr_is_visible, 341 }; 342 343 void *pci_vpd_alloc(struct pci_dev *dev, unsigned int *size) 344 { 345 unsigned int len; 346 void *buf; 347 int cnt; 348 349 if (!pci_vpd_available(dev, true)) 350 return ERR_PTR(-ENODEV); 351 352 len = dev->vpd.len; 353 buf = kmalloc(len, GFP_KERNEL); 354 if (!buf) 355 return ERR_PTR(-ENOMEM); 356 357 cnt = pci_read_vpd(dev, 0, len, buf); 358 if (cnt != len) { 359 kfree(buf); 360 return ERR_PTR(-EIO); 361 } 362 363 if (size) 364 *size = len; 365 366 return buf; 367 } 368 EXPORT_SYMBOL_GPL(pci_vpd_alloc); 369 370 static int pci_vpd_find_tag(const u8 *buf, unsigned int len, u8 rdt, unsigned int *size) 371 { 372 int i = 0; 373 374 /* look for LRDT tags only, end tag is the only SRDT tag */ 375 while (i + PCI_VPD_LRDT_TAG_SIZE <= len && buf[i] & PCI_VPD_LRDT) { 376 unsigned int lrdt_len = pci_vpd_lrdt_size(buf + i); 377 u8 tag = buf[i]; 378 379 i += PCI_VPD_LRDT_TAG_SIZE; 380 if (tag == rdt) { 381 if (i + lrdt_len > len) 382 lrdt_len = len - i; 383 if (size) 384 *size = lrdt_len; 385 return i; 386 } 387 388 i += lrdt_len; 389 } 390 391 return -ENOENT; 392 } 393 394 int pci_vpd_find_id_string(const u8 *buf, unsigned int len, unsigned int *size) 395 { 396 return pci_vpd_find_tag(buf, len, PCI_VPD_LRDT_ID_STRING, size); 397 } 398 EXPORT_SYMBOL_GPL(pci_vpd_find_id_string); 399 400 static int pci_vpd_find_info_keyword(const u8 *buf, unsigned int off, 401 unsigned int len, const char *kw) 402 { 403 int i; 404 405 for (i = off; i + PCI_VPD_INFO_FLD_HDR_SIZE <= off + len;) { 406 if (buf[i + 0] == kw[0] && 407 buf[i + 1] == kw[1]) 408 return i; 409 410 i += PCI_VPD_INFO_FLD_HDR_SIZE + 411 pci_vpd_info_field_size(&buf[i]); 412 } 413 414 return -ENOENT; 415 } 416 417 static ssize_t __pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf, 418 bool check_size) 419 { 420 ssize_t ret; 421 422 if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) { 423 dev = pci_get_func0_dev(dev); 424 if (!dev) 425 return -ENODEV; 426 427 ret = pci_vpd_read(dev, pos, count, buf, check_size); 428 pci_dev_put(dev); 429 return ret; 430 } 431 432 return pci_vpd_read(dev, pos, count, buf, check_size); 433 } 434 435 /** 436 * pci_read_vpd - Read one entry from Vital Product Data 437 * @dev: PCI device struct 438 * @pos: offset in VPD space 439 * @count: number of bytes to read 440 * @buf: pointer to where to store result 441 */ 442 ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf) 443 { 444 return __pci_read_vpd(dev, pos, count, buf, true); 445 } 446 EXPORT_SYMBOL(pci_read_vpd); 447 448 /* Same, but allow to access any address */ 449 ssize_t pci_read_vpd_any(struct pci_dev *dev, loff_t pos, size_t count, void *buf) 450 { 451 return __pci_read_vpd(dev, pos, count, buf, false); 452 } 453 EXPORT_SYMBOL(pci_read_vpd_any); 454 455 static ssize_t __pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, 456 const void *buf, bool check_size) 457 { 458 ssize_t ret; 459 460 if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) { 461 dev = pci_get_func0_dev(dev); 462 if (!dev) 463 return -ENODEV; 464 465 ret = pci_vpd_write(dev, pos, count, buf, check_size); 466 pci_dev_put(dev); 467 return ret; 468 } 469 470 return pci_vpd_write(dev, pos, count, buf, check_size); 471 } 472 473 /** 474 * pci_write_vpd - Write entry to Vital Product Data 475 * @dev: PCI device struct 476 * @pos: offset in VPD space 477 * @count: number of bytes to write 478 * @buf: buffer containing write data 479 */ 480 ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void *buf) 481 { 482 return __pci_write_vpd(dev, pos, count, buf, true); 483 } 484 EXPORT_SYMBOL(pci_write_vpd); 485 486 /* Same, but allow to access any address */ 487 ssize_t pci_write_vpd_any(struct pci_dev *dev, loff_t pos, size_t count, const void *buf) 488 { 489 return __pci_write_vpd(dev, pos, count, buf, false); 490 } 491 EXPORT_SYMBOL(pci_write_vpd_any); 492 493 int pci_vpd_find_ro_info_keyword(const void *buf, unsigned int len, 494 const char *kw, unsigned int *size) 495 { 496 int ro_start, infokw_start; 497 unsigned int ro_len, infokw_size; 498 499 ro_start = pci_vpd_find_tag(buf, len, PCI_VPD_LRDT_RO_DATA, &ro_len); 500 if (ro_start < 0) 501 return ro_start; 502 503 infokw_start = pci_vpd_find_info_keyword(buf, ro_start, ro_len, kw); 504 if (infokw_start < 0) 505 return infokw_start; 506 507 infokw_size = pci_vpd_info_field_size(buf + infokw_start); 508 infokw_start += PCI_VPD_INFO_FLD_HDR_SIZE; 509 510 if (infokw_start + infokw_size > len) 511 return -EINVAL; 512 513 if (size) 514 *size = infokw_size; 515 516 return infokw_start; 517 } 518 EXPORT_SYMBOL_GPL(pci_vpd_find_ro_info_keyword); 519 520 int pci_vpd_check_csum(const void *buf, unsigned int len) 521 { 522 const u8 *vpd = buf; 523 unsigned int size; 524 u8 csum = 0; 525 int rv_start; 526 527 rv_start = pci_vpd_find_ro_info_keyword(buf, len, PCI_VPD_RO_KEYWORD_CHKSUM, &size); 528 if (rv_start == -ENOENT) /* no checksum in VPD */ 529 return 1; 530 else if (rv_start < 0) 531 return rv_start; 532 533 if (!size) 534 return -EINVAL; 535 536 while (rv_start >= 0) 537 csum += vpd[rv_start--]; 538 539 return csum ? -EILSEQ : 0; 540 } 541 EXPORT_SYMBOL_GPL(pci_vpd_check_csum); 542 543 #ifdef CONFIG_PCI_QUIRKS 544 /* 545 * Quirk non-zero PCI functions to route VPD access through function 0 for 546 * devices that share VPD resources between functions. The functions are 547 * expected to be identical devices. 548 */ 549 static void quirk_f0_vpd_link(struct pci_dev *dev) 550 { 551 struct pci_dev *f0; 552 553 if (!PCI_FUNC(dev->devfn)) 554 return; 555 556 f0 = pci_get_func0_dev(dev); 557 if (!f0) 558 return; 559 560 if (f0->vpd.cap && dev->class == f0->class && 561 dev->vendor == f0->vendor && dev->device == f0->device) 562 dev->dev_flags |= PCI_DEV_FLAGS_VPD_REF_F0; 563 564 pci_dev_put(f0); 565 } 566 DECLARE_PCI_FIXUP_CLASS_EARLY(PCI_VENDOR_ID_INTEL, PCI_ANY_ID, 567 PCI_CLASS_NETWORK_ETHERNET, 8, quirk_f0_vpd_link); 568 569 /* 570 * If a device follows the VPD format spec, the PCI core will not read or 571 * write past the VPD End Tag. But some vendors do not follow the VPD 572 * format spec, so we can't tell how much data is safe to access. Devices 573 * may behave unpredictably if we access too much. Blacklist these devices 574 * so we don't touch VPD at all. 575 */ 576 static void quirk_blacklist_vpd(struct pci_dev *dev) 577 { 578 dev->vpd.len = PCI_VPD_SZ_INVALID; 579 pci_warn(dev, FW_BUG "disabling VPD access (can't determine size of non-standard VPD format)\n"); 580 } 581 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0060, quirk_blacklist_vpd); 582 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x007c, quirk_blacklist_vpd); 583 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0413, quirk_blacklist_vpd); 584 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0078, quirk_blacklist_vpd); 585 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0079, quirk_blacklist_vpd); 586 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0073, quirk_blacklist_vpd); 587 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x0071, quirk_blacklist_vpd); 588 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x005b, quirk_blacklist_vpd); 589 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x002f, quirk_blacklist_vpd); 590 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x005d, quirk_blacklist_vpd); 591 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_LSI_LOGIC, 0x005f, quirk_blacklist_vpd); 592 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_ATTANSIC, PCI_ANY_ID, quirk_blacklist_vpd); 593 /* 594 * The Amazon Annapurna Labs 0x0031 device id is reused for other non Root Port 595 * device types, so the quirk is registered for the PCI_CLASS_BRIDGE_PCI class. 596 */ 597 DECLARE_PCI_FIXUP_CLASS_HEADER(PCI_VENDOR_ID_AMAZON_ANNAPURNA_LABS, 0x0031, 598 PCI_CLASS_BRIDGE_PCI, 8, quirk_blacklist_vpd); 599 600 static void quirk_chelsio_extend_vpd(struct pci_dev *dev) 601 { 602 int chip = (dev->device & 0xf000) >> 12; 603 int func = (dev->device & 0x0f00) >> 8; 604 int prod = (dev->device & 0x00ff) >> 0; 605 606 /* 607 * If this is a T3-based adapter, there's a 1KB VPD area at offset 608 * 0xc00 which contains the preferred VPD values. If this is a T4 or 609 * later based adapter, the special VPD is at offset 0x400 for the 610 * Physical Functions (the SR-IOV Virtual Functions have no VPD 611 * Capabilities). The PCI VPD Access core routines will normally 612 * compute the size of the VPD by parsing the VPD Data Structure at 613 * offset 0x000. This will result in silent failures when attempting 614 * to accesses these other VPD areas which are beyond those computed 615 * limits. 616 */ 617 if (chip == 0x0 && prod >= 0x20) 618 dev->vpd.len = 8192; 619 else if (chip >= 0x4 && func < 0x8) 620 dev->vpd.len = 2048; 621 } 622 623 DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_CHELSIO, PCI_ANY_ID, 624 quirk_chelsio_extend_vpd); 625 626 #endif 627