1 #include <linux/delay.h> 2 #include <linux/pci.h> 3 #include <linux/module.h> 4 #include <linux/sched.h> 5 #include <linux/slab.h> 6 #include <linux/ioport.h> 7 #include <linux/wait.h> 8 9 #include "pci.h" 10 11 /* 12 * This interrupt-safe spinlock protects all accesses to PCI 13 * configuration space. 14 */ 15 16 DEFINE_RAW_SPINLOCK(pci_lock); 17 18 /* 19 * Wrappers for all PCI configuration access functions. They just check 20 * alignment, do locking and call the low-level functions pointed to 21 * by pci_dev->ops. 22 */ 23 24 #define PCI_byte_BAD 0 25 #define PCI_word_BAD (pos & 1) 26 #define PCI_dword_BAD (pos & 3) 27 28 #define PCI_OP_READ(size, type, len) \ 29 int pci_bus_read_config_##size \ 30 (struct pci_bus *bus, unsigned int devfn, int pos, type *value) \ 31 { \ 32 int res; \ 33 unsigned long flags; \ 34 u32 data = 0; \ 35 if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \ 36 raw_spin_lock_irqsave(&pci_lock, flags); \ 37 res = bus->ops->read(bus, devfn, pos, len, &data); \ 38 *value = (type)data; \ 39 raw_spin_unlock_irqrestore(&pci_lock, flags); \ 40 return res; \ 41 } 42 43 #define PCI_OP_WRITE(size, type, len) \ 44 int pci_bus_write_config_##size \ 45 (struct pci_bus *bus, unsigned int devfn, int pos, type value) \ 46 { \ 47 int res; \ 48 unsigned long flags; \ 49 if (PCI_##size##_BAD) return PCIBIOS_BAD_REGISTER_NUMBER; \ 50 raw_spin_lock_irqsave(&pci_lock, flags); \ 51 res = bus->ops->write(bus, devfn, pos, len, value); \ 52 raw_spin_unlock_irqrestore(&pci_lock, flags); \ 53 return res; \ 54 } 55 56 PCI_OP_READ(byte, u8, 1) 57 PCI_OP_READ(word, u16, 2) 58 PCI_OP_READ(dword, u32, 4) 59 PCI_OP_WRITE(byte, u8, 1) 60 PCI_OP_WRITE(word, u16, 2) 61 PCI_OP_WRITE(dword, u32, 4) 62 63 EXPORT_SYMBOL(pci_bus_read_config_byte); 64 EXPORT_SYMBOL(pci_bus_read_config_word); 65 EXPORT_SYMBOL(pci_bus_read_config_dword); 66 EXPORT_SYMBOL(pci_bus_write_config_byte); 67 EXPORT_SYMBOL(pci_bus_write_config_word); 68 EXPORT_SYMBOL(pci_bus_write_config_dword); 69 70 int pci_generic_config_read(struct pci_bus *bus, unsigned int devfn, 71 int where, int size, u32 *val) 72 { 73 void __iomem *addr; 74 75 addr = bus->ops->map_bus(bus, devfn, where); 76 if (!addr) { 77 *val = ~0; 78 return PCIBIOS_DEVICE_NOT_FOUND; 79 } 80 81 if (size == 1) 82 *val = readb(addr); 83 else if (size == 2) 84 *val = readw(addr); 85 else 86 *val = readl(addr); 87 88 return PCIBIOS_SUCCESSFUL; 89 } 90 EXPORT_SYMBOL_GPL(pci_generic_config_read); 91 92 int pci_generic_config_write(struct pci_bus *bus, unsigned int devfn, 93 int where, int size, u32 val) 94 { 95 void __iomem *addr; 96 97 addr = bus->ops->map_bus(bus, devfn, where); 98 if (!addr) 99 return PCIBIOS_DEVICE_NOT_FOUND; 100 101 if (size == 1) 102 writeb(val, addr); 103 else if (size == 2) 104 writew(val, addr); 105 else 106 writel(val, addr); 107 108 return PCIBIOS_SUCCESSFUL; 109 } 110 EXPORT_SYMBOL_GPL(pci_generic_config_write); 111 112 int pci_generic_config_read32(struct pci_bus *bus, unsigned int devfn, 113 int where, int size, u32 *val) 114 { 115 void __iomem *addr; 116 117 addr = bus->ops->map_bus(bus, devfn, where & ~0x3); 118 if (!addr) { 119 *val = ~0; 120 return PCIBIOS_DEVICE_NOT_FOUND; 121 } 122 123 *val = readl(addr); 124 125 if (size <= 2) 126 *val = (*val >> (8 * (where & 3))) & ((1 << (size * 8)) - 1); 127 128 return PCIBIOS_SUCCESSFUL; 129 } 130 EXPORT_SYMBOL_GPL(pci_generic_config_read32); 131 132 int pci_generic_config_write32(struct pci_bus *bus, unsigned int devfn, 133 int where, int size, u32 val) 134 { 135 void __iomem *addr; 136 u32 mask, tmp; 137 138 addr = bus->ops->map_bus(bus, devfn, where & ~0x3); 139 if (!addr) 140 return PCIBIOS_DEVICE_NOT_FOUND; 141 142 if (size == 4) { 143 writel(val, addr); 144 return PCIBIOS_SUCCESSFUL; 145 } else { 146 mask = ~(((1 << (size * 8)) - 1) << ((where & 0x3) * 8)); 147 } 148 149 tmp = readl(addr) & mask; 150 tmp |= val << ((where & 0x3) * 8); 151 writel(tmp, addr); 152 153 return PCIBIOS_SUCCESSFUL; 154 } 155 EXPORT_SYMBOL_GPL(pci_generic_config_write32); 156 157 /** 158 * pci_bus_set_ops - Set raw operations of pci bus 159 * @bus: pci bus struct 160 * @ops: new raw operations 161 * 162 * Return previous raw operations 163 */ 164 struct pci_ops *pci_bus_set_ops(struct pci_bus *bus, struct pci_ops *ops) 165 { 166 struct pci_ops *old_ops; 167 unsigned long flags; 168 169 raw_spin_lock_irqsave(&pci_lock, flags); 170 old_ops = bus->ops; 171 bus->ops = ops; 172 raw_spin_unlock_irqrestore(&pci_lock, flags); 173 return old_ops; 174 } 175 EXPORT_SYMBOL(pci_bus_set_ops); 176 177 /** 178 * pci_read_vpd - Read one entry from Vital Product Data 179 * @dev: pci device struct 180 * @pos: offset in vpd space 181 * @count: number of bytes to read 182 * @buf: pointer to where to store result 183 * 184 */ 185 ssize_t pci_read_vpd(struct pci_dev *dev, loff_t pos, size_t count, void *buf) 186 { 187 if (!dev->vpd || !dev->vpd->ops) 188 return -ENODEV; 189 return dev->vpd->ops->read(dev, pos, count, buf); 190 } 191 EXPORT_SYMBOL(pci_read_vpd); 192 193 /** 194 * pci_write_vpd - Write entry to Vital Product Data 195 * @dev: pci device struct 196 * @pos: offset in vpd space 197 * @count: number of bytes to write 198 * @buf: buffer containing write data 199 * 200 */ 201 ssize_t pci_write_vpd(struct pci_dev *dev, loff_t pos, size_t count, const void *buf) 202 { 203 if (!dev->vpd || !dev->vpd->ops) 204 return -ENODEV; 205 return dev->vpd->ops->write(dev, pos, count, buf); 206 } 207 EXPORT_SYMBOL(pci_write_vpd); 208 209 /* 210 * The following routines are to prevent the user from accessing PCI config 211 * space when it's unsafe to do so. Some devices require this during BIST and 212 * we're required to prevent it during D-state transitions. 213 * 214 * We have a bit per device to indicate it's blocked and a global wait queue 215 * for callers to sleep on until devices are unblocked. 216 */ 217 static DECLARE_WAIT_QUEUE_HEAD(pci_cfg_wait); 218 219 static noinline void pci_wait_cfg(struct pci_dev *dev) 220 { 221 DECLARE_WAITQUEUE(wait, current); 222 223 __add_wait_queue(&pci_cfg_wait, &wait); 224 do { 225 set_current_state(TASK_UNINTERRUPTIBLE); 226 raw_spin_unlock_irq(&pci_lock); 227 schedule(); 228 raw_spin_lock_irq(&pci_lock); 229 } while (dev->block_cfg_access); 230 __remove_wait_queue(&pci_cfg_wait, &wait); 231 } 232 233 /* Returns 0 on success, negative values indicate error. */ 234 #define PCI_USER_READ_CONFIG(size, type) \ 235 int pci_user_read_config_##size \ 236 (struct pci_dev *dev, int pos, type *val) \ 237 { \ 238 int ret = PCIBIOS_SUCCESSFUL; \ 239 u32 data = -1; \ 240 if (PCI_##size##_BAD) \ 241 return -EINVAL; \ 242 raw_spin_lock_irq(&pci_lock); \ 243 if (unlikely(dev->block_cfg_access)) \ 244 pci_wait_cfg(dev); \ 245 ret = dev->bus->ops->read(dev->bus, dev->devfn, \ 246 pos, sizeof(type), &data); \ 247 raw_spin_unlock_irq(&pci_lock); \ 248 *val = (type)data; \ 249 return pcibios_err_to_errno(ret); \ 250 } \ 251 EXPORT_SYMBOL_GPL(pci_user_read_config_##size); 252 253 /* Returns 0 on success, negative values indicate error. */ 254 #define PCI_USER_WRITE_CONFIG(size, type) \ 255 int pci_user_write_config_##size \ 256 (struct pci_dev *dev, int pos, type val) \ 257 { \ 258 int ret = PCIBIOS_SUCCESSFUL; \ 259 if (PCI_##size##_BAD) \ 260 return -EINVAL; \ 261 raw_spin_lock_irq(&pci_lock); \ 262 if (unlikely(dev->block_cfg_access)) \ 263 pci_wait_cfg(dev); \ 264 ret = dev->bus->ops->write(dev->bus, dev->devfn, \ 265 pos, sizeof(type), val); \ 266 raw_spin_unlock_irq(&pci_lock); \ 267 return pcibios_err_to_errno(ret); \ 268 } \ 269 EXPORT_SYMBOL_GPL(pci_user_write_config_##size); 270 271 PCI_USER_READ_CONFIG(byte, u8) 272 PCI_USER_READ_CONFIG(word, u16) 273 PCI_USER_READ_CONFIG(dword, u32) 274 PCI_USER_WRITE_CONFIG(byte, u8) 275 PCI_USER_WRITE_CONFIG(word, u16) 276 PCI_USER_WRITE_CONFIG(dword, u32) 277 278 /* VPD access through PCI 2.2+ VPD capability */ 279 280 #define PCI_VPD_PCI22_SIZE (PCI_VPD_ADDR_MASK + 1) 281 282 struct pci_vpd_pci22 { 283 struct pci_vpd base; 284 struct mutex lock; 285 u16 flag; 286 bool busy; 287 u8 cap; 288 }; 289 290 /* 291 * Wait for last operation to complete. 292 * This code has to spin since there is no other notification from the PCI 293 * hardware. Since the VPD is often implemented by serial attachment to an 294 * EEPROM, it may take many milliseconds to complete. 295 * 296 * Returns 0 on success, negative values indicate error. 297 */ 298 static int pci_vpd_pci22_wait(struct pci_dev *dev) 299 { 300 struct pci_vpd_pci22 *vpd = 301 container_of(dev->vpd, struct pci_vpd_pci22, base); 302 unsigned long timeout = jiffies + HZ/20 + 2; 303 u16 status; 304 int ret; 305 306 if (!vpd->busy) 307 return 0; 308 309 for (;;) { 310 ret = pci_user_read_config_word(dev, vpd->cap + PCI_VPD_ADDR, 311 &status); 312 if (ret < 0) 313 return ret; 314 315 if ((status & PCI_VPD_ADDR_F) == vpd->flag) { 316 vpd->busy = false; 317 return 0; 318 } 319 320 if (time_after(jiffies, timeout)) { 321 dev_printk(KERN_DEBUG, &dev->dev, "vpd r/w failed. This is likely a firmware bug on this device. Contact the card vendor for a firmware update\n"); 322 return -ETIMEDOUT; 323 } 324 if (fatal_signal_pending(current)) 325 return -EINTR; 326 if (!cond_resched()) 327 udelay(10); 328 } 329 } 330 331 static ssize_t pci_vpd_pci22_read(struct pci_dev *dev, loff_t pos, size_t count, 332 void *arg) 333 { 334 struct pci_vpd_pci22 *vpd = 335 container_of(dev->vpd, struct pci_vpd_pci22, base); 336 int ret; 337 loff_t end = pos + count; 338 u8 *buf = arg; 339 340 if (pos < 0 || pos > vpd->base.len || end > vpd->base.len) 341 return -EINVAL; 342 343 if (mutex_lock_killable(&vpd->lock)) 344 return -EINTR; 345 346 ret = pci_vpd_pci22_wait(dev); 347 if (ret < 0) 348 goto out; 349 350 while (pos < end) { 351 u32 val; 352 unsigned int i, skip; 353 354 ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR, 355 pos & ~3); 356 if (ret < 0) 357 break; 358 vpd->busy = true; 359 vpd->flag = PCI_VPD_ADDR_F; 360 ret = pci_vpd_pci22_wait(dev); 361 if (ret < 0) 362 break; 363 364 ret = pci_user_read_config_dword(dev, vpd->cap + PCI_VPD_DATA, &val); 365 if (ret < 0) 366 break; 367 368 skip = pos & 3; 369 for (i = 0; i < sizeof(u32); i++) { 370 if (i >= skip) { 371 *buf++ = val; 372 if (++pos == end) 373 break; 374 } 375 val >>= 8; 376 } 377 } 378 out: 379 mutex_unlock(&vpd->lock); 380 return ret ? ret : count; 381 } 382 383 static ssize_t pci_vpd_pci22_write(struct pci_dev *dev, loff_t pos, size_t count, 384 const void *arg) 385 { 386 struct pci_vpd_pci22 *vpd = 387 container_of(dev->vpd, struct pci_vpd_pci22, base); 388 const u8 *buf = arg; 389 loff_t end = pos + count; 390 int ret = 0; 391 392 if (pos < 0 || (pos & 3) || (count & 3) || end > vpd->base.len) 393 return -EINVAL; 394 395 if (mutex_lock_killable(&vpd->lock)) 396 return -EINTR; 397 398 ret = pci_vpd_pci22_wait(dev); 399 if (ret < 0) 400 goto out; 401 402 while (pos < end) { 403 u32 val; 404 405 val = *buf++; 406 val |= *buf++ << 8; 407 val |= *buf++ << 16; 408 val |= *buf++ << 24; 409 410 ret = pci_user_write_config_dword(dev, vpd->cap + PCI_VPD_DATA, val); 411 if (ret < 0) 412 break; 413 ret = pci_user_write_config_word(dev, vpd->cap + PCI_VPD_ADDR, 414 pos | PCI_VPD_ADDR_F); 415 if (ret < 0) 416 break; 417 418 vpd->busy = true; 419 vpd->flag = 0; 420 ret = pci_vpd_pci22_wait(dev); 421 if (ret < 0) 422 break; 423 424 pos += sizeof(u32); 425 } 426 out: 427 mutex_unlock(&vpd->lock); 428 return ret ? ret : count; 429 } 430 431 static void pci_vpd_pci22_release(struct pci_dev *dev) 432 { 433 kfree(container_of(dev->vpd, struct pci_vpd_pci22, base)); 434 } 435 436 static const struct pci_vpd_ops pci_vpd_pci22_ops = { 437 .read = pci_vpd_pci22_read, 438 .write = pci_vpd_pci22_write, 439 .release = pci_vpd_pci22_release, 440 }; 441 442 static ssize_t pci_vpd_f0_read(struct pci_dev *dev, loff_t pos, size_t count, 443 void *arg) 444 { 445 struct pci_dev *tdev = pci_get_slot(dev->bus, 446 PCI_DEVFN(PCI_SLOT(dev->devfn), 0)); 447 ssize_t ret; 448 449 if (!tdev) 450 return -ENODEV; 451 452 ret = pci_read_vpd(tdev, pos, count, arg); 453 pci_dev_put(tdev); 454 return ret; 455 } 456 457 static ssize_t pci_vpd_f0_write(struct pci_dev *dev, loff_t pos, size_t count, 458 const void *arg) 459 { 460 struct pci_dev *tdev = pci_get_slot(dev->bus, 461 PCI_DEVFN(PCI_SLOT(dev->devfn), 0)); 462 ssize_t ret; 463 464 if (!tdev) 465 return -ENODEV; 466 467 ret = pci_write_vpd(tdev, pos, count, arg); 468 pci_dev_put(tdev); 469 return ret; 470 } 471 472 static const struct pci_vpd_ops pci_vpd_f0_ops = { 473 .read = pci_vpd_f0_read, 474 .write = pci_vpd_f0_write, 475 .release = pci_vpd_pci22_release, 476 }; 477 478 int pci_vpd_pci22_init(struct pci_dev *dev) 479 { 480 struct pci_vpd_pci22 *vpd; 481 u8 cap; 482 483 cap = pci_find_capability(dev, PCI_CAP_ID_VPD); 484 if (!cap) 485 return -ENODEV; 486 487 vpd = kzalloc(sizeof(*vpd), GFP_ATOMIC); 488 if (!vpd) 489 return -ENOMEM; 490 491 vpd->base.len = PCI_VPD_PCI22_SIZE; 492 if (dev->dev_flags & PCI_DEV_FLAGS_VPD_REF_F0) 493 vpd->base.ops = &pci_vpd_f0_ops; 494 else 495 vpd->base.ops = &pci_vpd_pci22_ops; 496 mutex_init(&vpd->lock); 497 vpd->cap = cap; 498 vpd->busy = false; 499 dev->vpd = &vpd->base; 500 return 0; 501 } 502 503 /** 504 * pci_cfg_access_lock - Lock PCI config reads/writes 505 * @dev: pci device struct 506 * 507 * When access is locked, any userspace reads or writes to config 508 * space and concurrent lock requests will sleep until access is 509 * allowed via pci_cfg_access_unlocked again. 510 */ 511 void pci_cfg_access_lock(struct pci_dev *dev) 512 { 513 might_sleep(); 514 515 raw_spin_lock_irq(&pci_lock); 516 if (dev->block_cfg_access) 517 pci_wait_cfg(dev); 518 dev->block_cfg_access = 1; 519 raw_spin_unlock_irq(&pci_lock); 520 } 521 EXPORT_SYMBOL_GPL(pci_cfg_access_lock); 522 523 /** 524 * pci_cfg_access_trylock - try to lock PCI config reads/writes 525 * @dev: pci device struct 526 * 527 * Same as pci_cfg_access_lock, but will return 0 if access is 528 * already locked, 1 otherwise. This function can be used from 529 * atomic contexts. 530 */ 531 bool pci_cfg_access_trylock(struct pci_dev *dev) 532 { 533 unsigned long flags; 534 bool locked = true; 535 536 raw_spin_lock_irqsave(&pci_lock, flags); 537 if (dev->block_cfg_access) 538 locked = false; 539 else 540 dev->block_cfg_access = 1; 541 raw_spin_unlock_irqrestore(&pci_lock, flags); 542 543 return locked; 544 } 545 EXPORT_SYMBOL_GPL(pci_cfg_access_trylock); 546 547 /** 548 * pci_cfg_access_unlock - Unlock PCI config reads/writes 549 * @dev: pci device struct 550 * 551 * This function allows PCI config accesses to resume. 552 */ 553 void pci_cfg_access_unlock(struct pci_dev *dev) 554 { 555 unsigned long flags; 556 557 raw_spin_lock_irqsave(&pci_lock, flags); 558 559 /* This indicates a problem in the caller, but we don't need 560 * to kill them, unlike a double-block above. */ 561 WARN_ON(!dev->block_cfg_access); 562 563 dev->block_cfg_access = 0; 564 wake_up_all(&pci_cfg_wait); 565 raw_spin_unlock_irqrestore(&pci_lock, flags); 566 } 567 EXPORT_SYMBOL_GPL(pci_cfg_access_unlock); 568 569 static inline int pcie_cap_version(const struct pci_dev *dev) 570 { 571 return pcie_caps_reg(dev) & PCI_EXP_FLAGS_VERS; 572 } 573 574 static bool pcie_downstream_port(const struct pci_dev *dev) 575 { 576 int type = pci_pcie_type(dev); 577 578 return type == PCI_EXP_TYPE_ROOT_PORT || 579 type == PCI_EXP_TYPE_DOWNSTREAM; 580 } 581 582 bool pcie_cap_has_lnkctl(const struct pci_dev *dev) 583 { 584 int type = pci_pcie_type(dev); 585 586 return type == PCI_EXP_TYPE_ENDPOINT || 587 type == PCI_EXP_TYPE_LEG_END || 588 type == PCI_EXP_TYPE_ROOT_PORT || 589 type == PCI_EXP_TYPE_UPSTREAM || 590 type == PCI_EXP_TYPE_DOWNSTREAM || 591 type == PCI_EXP_TYPE_PCI_BRIDGE || 592 type == PCI_EXP_TYPE_PCIE_BRIDGE; 593 } 594 595 static inline bool pcie_cap_has_sltctl(const struct pci_dev *dev) 596 { 597 return pcie_downstream_port(dev) && 598 pcie_caps_reg(dev) & PCI_EXP_FLAGS_SLOT; 599 } 600 601 static inline bool pcie_cap_has_rtctl(const struct pci_dev *dev) 602 { 603 int type = pci_pcie_type(dev); 604 605 return type == PCI_EXP_TYPE_ROOT_PORT || 606 type == PCI_EXP_TYPE_RC_EC; 607 } 608 609 static bool pcie_capability_reg_implemented(struct pci_dev *dev, int pos) 610 { 611 if (!pci_is_pcie(dev)) 612 return false; 613 614 switch (pos) { 615 case PCI_EXP_FLAGS: 616 return true; 617 case PCI_EXP_DEVCAP: 618 case PCI_EXP_DEVCTL: 619 case PCI_EXP_DEVSTA: 620 return true; 621 case PCI_EXP_LNKCAP: 622 case PCI_EXP_LNKCTL: 623 case PCI_EXP_LNKSTA: 624 return pcie_cap_has_lnkctl(dev); 625 case PCI_EXP_SLTCAP: 626 case PCI_EXP_SLTCTL: 627 case PCI_EXP_SLTSTA: 628 return pcie_cap_has_sltctl(dev); 629 case PCI_EXP_RTCTL: 630 case PCI_EXP_RTCAP: 631 case PCI_EXP_RTSTA: 632 return pcie_cap_has_rtctl(dev); 633 case PCI_EXP_DEVCAP2: 634 case PCI_EXP_DEVCTL2: 635 case PCI_EXP_LNKCAP2: 636 case PCI_EXP_LNKCTL2: 637 case PCI_EXP_LNKSTA2: 638 return pcie_cap_version(dev) > 1; 639 default: 640 return false; 641 } 642 } 643 644 /* 645 * Note that these accessor functions are only for the "PCI Express 646 * Capability" (see PCIe spec r3.0, sec 7.8). They do not apply to the 647 * other "PCI Express Extended Capabilities" (AER, VC, ACS, MFVC, etc.) 648 */ 649 int pcie_capability_read_word(struct pci_dev *dev, int pos, u16 *val) 650 { 651 int ret; 652 653 *val = 0; 654 if (pos & 1) 655 return -EINVAL; 656 657 if (pcie_capability_reg_implemented(dev, pos)) { 658 ret = pci_read_config_word(dev, pci_pcie_cap(dev) + pos, val); 659 /* 660 * Reset *val to 0 if pci_read_config_word() fails, it may 661 * have been written as 0xFFFF if hardware error happens 662 * during pci_read_config_word(). 663 */ 664 if (ret) 665 *val = 0; 666 return ret; 667 } 668 669 /* 670 * For Functions that do not implement the Slot Capabilities, 671 * Slot Status, and Slot Control registers, these spaces must 672 * be hardwired to 0b, with the exception of the Presence Detect 673 * State bit in the Slot Status register of Downstream Ports, 674 * which must be hardwired to 1b. (PCIe Base Spec 3.0, sec 7.8) 675 */ 676 if (pci_is_pcie(dev) && pcie_downstream_port(dev) && 677 pos == PCI_EXP_SLTSTA) 678 *val = PCI_EXP_SLTSTA_PDS; 679 680 return 0; 681 } 682 EXPORT_SYMBOL(pcie_capability_read_word); 683 684 int pcie_capability_read_dword(struct pci_dev *dev, int pos, u32 *val) 685 { 686 int ret; 687 688 *val = 0; 689 if (pos & 3) 690 return -EINVAL; 691 692 if (pcie_capability_reg_implemented(dev, pos)) { 693 ret = pci_read_config_dword(dev, pci_pcie_cap(dev) + pos, val); 694 /* 695 * Reset *val to 0 if pci_read_config_dword() fails, it may 696 * have been written as 0xFFFFFFFF if hardware error happens 697 * during pci_read_config_dword(). 698 */ 699 if (ret) 700 *val = 0; 701 return ret; 702 } 703 704 if (pci_is_pcie(dev) && pcie_downstream_port(dev) && 705 pos == PCI_EXP_SLTSTA) 706 *val = PCI_EXP_SLTSTA_PDS; 707 708 return 0; 709 } 710 EXPORT_SYMBOL(pcie_capability_read_dword); 711 712 int pcie_capability_write_word(struct pci_dev *dev, int pos, u16 val) 713 { 714 if (pos & 1) 715 return -EINVAL; 716 717 if (!pcie_capability_reg_implemented(dev, pos)) 718 return 0; 719 720 return pci_write_config_word(dev, pci_pcie_cap(dev) + pos, val); 721 } 722 EXPORT_SYMBOL(pcie_capability_write_word); 723 724 int pcie_capability_write_dword(struct pci_dev *dev, int pos, u32 val) 725 { 726 if (pos & 3) 727 return -EINVAL; 728 729 if (!pcie_capability_reg_implemented(dev, pos)) 730 return 0; 731 732 return pci_write_config_dword(dev, pci_pcie_cap(dev) + pos, val); 733 } 734 EXPORT_SYMBOL(pcie_capability_write_dword); 735 736 int pcie_capability_clear_and_set_word(struct pci_dev *dev, int pos, 737 u16 clear, u16 set) 738 { 739 int ret; 740 u16 val; 741 742 ret = pcie_capability_read_word(dev, pos, &val); 743 if (!ret) { 744 val &= ~clear; 745 val |= set; 746 ret = pcie_capability_write_word(dev, pos, val); 747 } 748 749 return ret; 750 } 751 EXPORT_SYMBOL(pcie_capability_clear_and_set_word); 752 753 int pcie_capability_clear_and_set_dword(struct pci_dev *dev, int pos, 754 u32 clear, u32 set) 755 { 756 int ret; 757 u32 val; 758 759 ret = pcie_capability_read_dword(dev, pos, &val); 760 if (!ret) { 761 val &= ~clear; 762 val |= set; 763 ret = pcie_capability_write_dword(dev, pos, val); 764 } 765 766 return ret; 767 } 768 EXPORT_SYMBOL(pcie_capability_clear_and_set_dword); 769