// SPDX-License-Identifier: GPL-2.0 /* * PCI detection and setup code */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "pci.h" #define CARDBUS_LATENCY_TIMER 176 /* secondary latency timer */ #define CARDBUS_RESERVE_BUSNR 3 static struct resource busn_resource = { .name = "PCI busn", .start = 0, .end = 255, .flags = IORESOURCE_BUS, }; /* Ugh. Need to stop exporting this to modules. */ LIST_HEAD(pci_root_buses); EXPORT_SYMBOL(pci_root_buses); static LIST_HEAD(pci_domain_busn_res_list); struct pci_domain_busn_res { struct list_head list; struct resource res; int domain_nr; }; static struct resource *get_pci_domain_busn_res(int domain_nr) { struct pci_domain_busn_res *r; list_for_each_entry(r, &pci_domain_busn_res_list, list) if (r->domain_nr == domain_nr) return &r->res; r = kzalloc(sizeof(*r), GFP_KERNEL); if (!r) return NULL; r->domain_nr = domain_nr; r->res.start = 0; r->res.end = 0xff; r->res.flags = IORESOURCE_BUS | IORESOURCE_PCI_FIXED; list_add_tail(&r->list, &pci_domain_busn_res_list); return &r->res; } /* * Some device drivers need know if PCI is initiated. * Basically, we think PCI is not initiated when there * is no device to be found on the pci_bus_type. */ int no_pci_devices(void) { struct device *dev; int no_devices; dev = bus_find_next_device(&pci_bus_type, NULL); no_devices = (dev == NULL); put_device(dev); return no_devices; } EXPORT_SYMBOL(no_pci_devices); /* * PCI Bus Class */ static void release_pcibus_dev(struct device *dev) { struct pci_bus *pci_bus = to_pci_bus(dev); put_device(pci_bus->bridge); pci_bus_remove_resources(pci_bus); pci_release_bus_of_node(pci_bus); kfree(pci_bus); } static struct class pcibus_class = { .name = "pci_bus", .dev_release = &release_pcibus_dev, .dev_groups = pcibus_groups, }; static int __init pcibus_class_init(void) { return class_register(&pcibus_class); } postcore_initcall(pcibus_class_init); static u64 pci_size(u64 base, u64 maxbase, u64 mask) { u64 size = mask & maxbase; /* Find the significant bits */ if (!size) return 0; /* * Get the lowest of them to find the decode size, and from that * the extent. */ size = size & ~(size-1); /* * base == maxbase can be valid only if the BAR has already been * programmed with all 1s. */ if (base == maxbase && ((base | (size - 1)) & mask) != mask) return 0; return size; } static inline unsigned long decode_bar(struct pci_dev *dev, u32 bar) { u32 mem_type; unsigned long flags; if ((bar & PCI_BASE_ADDRESS_SPACE) == PCI_BASE_ADDRESS_SPACE_IO) { flags = bar & ~PCI_BASE_ADDRESS_IO_MASK; flags |= IORESOURCE_IO; return flags; } flags = bar & ~PCI_BASE_ADDRESS_MEM_MASK; flags |= IORESOURCE_MEM; if (flags & PCI_BASE_ADDRESS_MEM_PREFETCH) flags |= IORESOURCE_PREFETCH; mem_type = bar & PCI_BASE_ADDRESS_MEM_TYPE_MASK; switch (mem_type) { case PCI_BASE_ADDRESS_MEM_TYPE_32: break; case PCI_BASE_ADDRESS_MEM_TYPE_1M: /* 1M mem BAR treated as 32-bit BAR */ break; case PCI_BASE_ADDRESS_MEM_TYPE_64: flags |= IORESOURCE_MEM_64; break; default: /* mem unknown type treated as 32-bit BAR */ break; } return flags; } #define PCI_COMMAND_DECODE_ENABLE (PCI_COMMAND_MEMORY | PCI_COMMAND_IO) /** * __pci_read_base - Read a PCI BAR * @dev: the PCI device * @type: type of the BAR * @res: resource buffer to be filled in * @pos: BAR position in the config space * * Returns 1 if the BAR is 64-bit, or 0 if 32-bit. */ int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type, struct resource *res, unsigned int pos) { u32 l = 0, sz = 0, mask; u64 l64, sz64, mask64; u16 orig_cmd; struct pci_bus_region region, inverted_region; mask = type ? PCI_ROM_ADDRESS_MASK : ~0; /* No printks while decoding is disabled! */ if (!dev->mmio_always_on) { pci_read_config_word(dev, PCI_COMMAND, &orig_cmd); if (orig_cmd & PCI_COMMAND_DECODE_ENABLE) { pci_write_config_word(dev, PCI_COMMAND, orig_cmd & ~PCI_COMMAND_DECODE_ENABLE); } } res->name = pci_name(dev); pci_read_config_dword(dev, pos, &l); pci_write_config_dword(dev, pos, l | mask); pci_read_config_dword(dev, pos, &sz); pci_write_config_dword(dev, pos, l); /* * All bits set in sz means the device isn't working properly. * If the BAR isn't implemented, all bits must be 0. If it's a * memory BAR or a ROM, bit 0 must be clear; if it's an io BAR, bit * 1 must be clear. */ if (PCI_POSSIBLE_ERROR(sz)) sz = 0; /* * I don't know how l can have all bits set. Copied from old code. * Maybe it fixes a bug on some ancient platform. */ if (PCI_POSSIBLE_ERROR(l)) l = 0; if (type == pci_bar_unknown) { res->flags = decode_bar(dev, l); res->flags |= IORESOURCE_SIZEALIGN; if (res->flags & IORESOURCE_IO) { l64 = l & PCI_BASE_ADDRESS_IO_MASK; sz64 = sz & PCI_BASE_ADDRESS_IO_MASK; mask64 = PCI_BASE_ADDRESS_IO_MASK & (u32)IO_SPACE_LIMIT; } else { l64 = l & PCI_BASE_ADDRESS_MEM_MASK; sz64 = sz & PCI_BASE_ADDRESS_MEM_MASK; mask64 = (u32)PCI_BASE_ADDRESS_MEM_MASK; } } else { if (l & PCI_ROM_ADDRESS_ENABLE) res->flags |= IORESOURCE_ROM_ENABLE; l64 = l & PCI_ROM_ADDRESS_MASK; sz64 = sz & PCI_ROM_ADDRESS_MASK; mask64 = PCI_ROM_ADDRESS_MASK; } if (res->flags & IORESOURCE_MEM_64) { pci_read_config_dword(dev, pos + 4, &l); pci_write_config_dword(dev, pos + 4, ~0); pci_read_config_dword(dev, pos + 4, &sz); pci_write_config_dword(dev, pos + 4, l); l64 |= ((u64)l << 32); sz64 |= ((u64)sz << 32); mask64 |= ((u64)~0 << 32); } if (!dev->mmio_always_on && (orig_cmd & PCI_COMMAND_DECODE_ENABLE)) pci_write_config_word(dev, PCI_COMMAND, orig_cmd); if (!sz64) goto fail; sz64 = pci_size(l64, sz64, mask64); if (!sz64) { pci_info(dev, FW_BUG "reg 0x%x: invalid BAR (can't size)\n", pos); goto fail; } if (res->flags & IORESOURCE_MEM_64) { if ((sizeof(pci_bus_addr_t) < 8 || sizeof(resource_size_t) < 8) && sz64 > 0x100000000ULL) { res->flags |= IORESOURCE_UNSET | IORESOURCE_DISABLED; res->start = 0; res->end = 0; pci_err(dev, "reg 0x%x: can't handle BAR larger than 4GB (size %#010llx)\n", pos, (unsigned long long)sz64); goto out; } if ((sizeof(pci_bus_addr_t) < 8) && l) { /* Above 32-bit boundary; try to reallocate */ res->flags |= IORESOURCE_UNSET; res->start = 0; res->end = sz64 - 1; pci_info(dev, "reg 0x%x: can't handle BAR above 4GB (bus address %#010llx)\n", pos, (unsigned long long)l64); goto out; } } region.start = l64; region.end = l64 + sz64 - 1; pcibios_bus_to_resource(dev->bus, res, ®ion); pcibios_resource_to_bus(dev->bus, &inverted_region, res); /* * If "A" is a BAR value (a bus address), "bus_to_resource(A)" is * the corresponding resource address (the physical address used by * the CPU. Converting that resource address back to a bus address * should yield the original BAR value: * * resource_to_bus(bus_to_resource(A)) == A * * If it doesn't, CPU accesses to "bus_to_resource(A)" will not * be claimed by the device. */ if (inverted_region.start != region.start) { res->flags |= IORESOURCE_UNSET; res->start = 0; res->end = region.end - region.start; pci_info(dev, "reg 0x%x: initial BAR value %#010llx invalid\n", pos, (unsigned long long)region.start); } goto out; fail: res->flags = 0; out: if (res->flags) pci_info(dev, "reg 0x%x: %pR\n", pos, res); return (res->flags & IORESOURCE_MEM_64) ? 1 : 0; } static void pci_read_bases(struct pci_dev *dev, unsigned int howmany, int rom) { unsigned int pos, reg; if (dev->non_compliant_bars) return; /* Per PCIe r4.0, sec 9.3.4.1.11, the VF BARs are all RO Zero */ if (dev->is_virtfn) return; for (pos = 0; pos < howmany; pos++) { struct resource *res = &dev->resource[pos]; reg = PCI_BASE_ADDRESS_0 + (pos << 2); pos += __pci_read_base(dev, pci_bar_unknown, res, reg); } if (rom) { struct resource *res = &dev->resource[PCI_ROM_RESOURCE]; dev->rom_base_reg = rom; res->flags = IORESOURCE_MEM | IORESOURCE_PREFETCH | IORESOURCE_READONLY | IORESOURCE_SIZEALIGN; __pci_read_base(dev, pci_bar_mem32, res, rom); } } static void pci_read_bridge_windows(struct pci_dev *bridge) { u16 io; u32 pmem, tmp; pci_read_config_word(bridge, PCI_IO_BASE, &io); if (!io) { pci_write_config_word(bridge, PCI_IO_BASE, 0xe0f0); pci_read_config_word(bridge, PCI_IO_BASE, &io); pci_write_config_word(bridge, PCI_IO_BASE, 0x0); } if (io) bridge->io_window = 1; /* * DECchip 21050 pass 2 errata: the bridge may miss an address * disconnect boundary by one PCI data phase. Workaround: do not * use prefetching on this device. */ if (bridge->vendor == PCI_VENDOR_ID_DEC && bridge->device == 0x0001) return; pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem); if (!pmem) { pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0xffe0fff0); pci_read_config_dword(bridge, PCI_PREF_MEMORY_BASE, &pmem); pci_write_config_dword(bridge, PCI_PREF_MEMORY_BASE, 0x0); } if (!pmem) return; bridge->pref_window = 1; if ((pmem & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) { /* * Bridge claims to have a 64-bit prefetchable memory * window; verify that the upper bits are actually * writable. */ pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &pmem); pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, 0xffffffff); pci_read_config_dword(bridge, PCI_PREF_BASE_UPPER32, &tmp); pci_write_config_dword(bridge, PCI_PREF_BASE_UPPER32, pmem); if (tmp) bridge->pref_64_window = 1; } } static void pci_read_bridge_io(struct pci_bus *child) { struct pci_dev *dev = child->self; u8 io_base_lo, io_limit_lo; unsigned long io_mask, io_granularity, base, limit; struct pci_bus_region region; struct resource *res; io_mask = PCI_IO_RANGE_MASK; io_granularity = 0x1000; if (dev->io_window_1k) { /* Support 1K I/O space granularity */ io_mask = PCI_IO_1K_RANGE_MASK; io_granularity = 0x400; } res = child->resource[0]; pci_read_config_byte(dev, PCI_IO_BASE, &io_base_lo); pci_read_config_byte(dev, PCI_IO_LIMIT, &io_limit_lo); base = (io_base_lo & io_mask) << 8; limit = (io_limit_lo & io_mask) << 8; if ((io_base_lo & PCI_IO_RANGE_TYPE_MASK) == PCI_IO_RANGE_TYPE_32) { u16 io_base_hi, io_limit_hi; pci_read_config_word(dev, PCI_IO_BASE_UPPER16, &io_base_hi); pci_read_config_word(dev, PCI_IO_LIMIT_UPPER16, &io_limit_hi); base |= ((unsigned long) io_base_hi << 16); limit |= ((unsigned long) io_limit_hi << 16); } if (base <= limit) { res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO; region.start = base; region.end = limit + io_granularity - 1; pcibios_bus_to_resource(dev->bus, res, ®ion); pci_info(dev, " bridge window %pR\n", res); } } static void pci_read_bridge_mmio(struct pci_bus *child) { struct pci_dev *dev = child->self; u16 mem_base_lo, mem_limit_lo; unsigned long base, limit; struct pci_bus_region region; struct resource *res; res = child->resource[1]; pci_read_config_word(dev, PCI_MEMORY_BASE, &mem_base_lo); pci_read_config_word(dev, PCI_MEMORY_LIMIT, &mem_limit_lo); base = ((unsigned long) mem_base_lo & PCI_MEMORY_RANGE_MASK) << 16; limit = ((unsigned long) mem_limit_lo & PCI_MEMORY_RANGE_MASK) << 16; if (base <= limit) { res->flags = (mem_base_lo & PCI_MEMORY_RANGE_TYPE_MASK) | IORESOURCE_MEM; region.start = base; region.end = limit + 0xfffff; pcibios_bus_to_resource(dev->bus, res, ®ion); pci_info(dev, " bridge window %pR\n", res); } } static void pci_read_bridge_mmio_pref(struct pci_bus *child) { struct pci_dev *dev = child->self; u16 mem_base_lo, mem_limit_lo; u64 base64, limit64; pci_bus_addr_t base, limit; struct pci_bus_region region; struct resource *res; res = child->resource[2]; pci_read_config_word(dev, PCI_PREF_MEMORY_BASE, &mem_base_lo); pci_read_config_word(dev, PCI_PREF_MEMORY_LIMIT, &mem_limit_lo); base64 = (mem_base_lo & PCI_PREF_RANGE_MASK) << 16; limit64 = (mem_limit_lo & PCI_PREF_RANGE_MASK) << 16; if ((mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) == PCI_PREF_RANGE_TYPE_64) { u32 mem_base_hi, mem_limit_hi; pci_read_config_dword(dev, PCI_PREF_BASE_UPPER32, &mem_base_hi); pci_read_config_dword(dev, PCI_PREF_LIMIT_UPPER32, &mem_limit_hi); /* * Some bridges set the base > limit by default, and some * (broken) BIOSes do not initialize them. If we find * this, just assume they are not being used. */ if (mem_base_hi <= mem_limit_hi) { base64 |= (u64) mem_base_hi << 32; limit64 |= (u64) mem_limit_hi << 32; } } base = (pci_bus_addr_t) base64; limit = (pci_bus_addr_t) limit64; if (base != base64) { pci_err(dev, "can't handle bridge window above 4GB (bus address %#010llx)\n", (unsigned long long) base64); return; } if (base <= limit) { res->flags = (mem_base_lo & PCI_PREF_RANGE_TYPE_MASK) | IORESOURCE_MEM | IORESOURCE_PREFETCH; if (res->flags & PCI_PREF_RANGE_TYPE_64) res->flags |= IORESOURCE_MEM_64; region.start = base; region.end = limit + 0xfffff; pcibios_bus_to_resource(dev->bus, res, ®ion); pci_info(dev, " bridge window %pR\n", res); } } void pci_read_bridge_bases(struct pci_bus *child) { struct pci_dev *dev = child->self; struct resource *res; int i; if (pci_is_root_bus(child)) /* It's a host bus, nothing to read */ return; pci_info(dev, "PCI bridge to %pR%s\n", &child->busn_res, dev->transparent ? " (subtractive decode)" : ""); pci_bus_remove_resources(child); for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) child->resource[i] = &dev->resource[PCI_BRIDGE_RESOURCES+i]; pci_read_bridge_io(child); pci_read_bridge_mmio(child); pci_read_bridge_mmio_pref(child); if (dev->transparent) { pci_bus_for_each_resource(child->parent, res, i) { if (res && res->flags) { pci_bus_add_resource(child, res, PCI_SUBTRACTIVE_DECODE); pci_info(dev, " bridge window %pR (subtractive decode)\n", res); } } } } static struct pci_bus *pci_alloc_bus(struct pci_bus *parent) { struct pci_bus *b; b = kzalloc(sizeof(*b), GFP_KERNEL); if (!b) return NULL; INIT_LIST_HEAD(&b->node); INIT_LIST_HEAD(&b->children); INIT_LIST_HEAD(&b->devices); INIT_LIST_HEAD(&b->slots); INIT_LIST_HEAD(&b->resources); b->max_bus_speed = PCI_SPEED_UNKNOWN; b->cur_bus_speed = PCI_SPEED_UNKNOWN; #ifdef CONFIG_PCI_DOMAINS_GENERIC if (parent) b->domain_nr = parent->domain_nr; #endif return b; } static void pci_release_host_bridge_dev(struct device *dev) { struct pci_host_bridge *bridge = to_pci_host_bridge(dev); if (bridge->release_fn) bridge->release_fn(bridge); pci_free_resource_list(&bridge->windows); pci_free_resource_list(&bridge->dma_ranges); kfree(bridge); } static void pci_init_host_bridge(struct pci_host_bridge *bridge) { INIT_LIST_HEAD(&bridge->windows); INIT_LIST_HEAD(&bridge->dma_ranges); /* * We assume we can manage these PCIe features. Some systems may * reserve these for use by the platform itself, e.g., an ACPI BIOS * may implement its own AER handling and use _OSC to prevent the * OS from interfering. */ bridge->native_aer = 1; bridge->native_pcie_hotplug = 1; bridge->native_shpc_hotplug = 1; bridge->native_pme = 1; bridge->native_ltr = 1; bridge->native_dpc = 1; bridge->domain_nr = PCI_DOMAIN_NR_NOT_SET; device_initialize(&bridge->dev); } struct pci_host_bridge *pci_alloc_host_bridge(size_t priv) { struct pci_host_bridge *bridge; bridge = kzalloc(sizeof(*bridge) + priv, GFP_KERNEL); if (!bridge) return NULL; pci_init_host_bridge(bridge); bridge->dev.release = pci_release_host_bridge_dev; return bridge; } EXPORT_SYMBOL(pci_alloc_host_bridge); static void devm_pci_alloc_host_bridge_release(void *data) { pci_free_host_bridge(data); } struct pci_host_bridge *devm_pci_alloc_host_bridge(struct device *dev, size_t priv) { int ret; struct pci_host_bridge *bridge; bridge = pci_alloc_host_bridge(priv); if (!bridge) return NULL; bridge->dev.parent = dev; ret = devm_add_action_or_reset(dev, devm_pci_alloc_host_bridge_release, bridge); if (ret) return NULL; ret = devm_of_pci_bridge_init(dev, bridge); if (ret) return NULL; return bridge; } EXPORT_SYMBOL(devm_pci_alloc_host_bridge); void pci_free_host_bridge(struct pci_host_bridge *bridge) { put_device(&bridge->dev); } EXPORT_SYMBOL(pci_free_host_bridge); /* Indexed by PCI_X_SSTATUS_FREQ (secondary bus mode and frequency) */ static const unsigned char pcix_bus_speed[] = { PCI_SPEED_UNKNOWN, /* 0 */ PCI_SPEED_66MHz_PCIX, /* 1 */ PCI_SPEED_100MHz_PCIX, /* 2 */ PCI_SPEED_133MHz_PCIX, /* 3 */ PCI_SPEED_UNKNOWN, /* 4 */ PCI_SPEED_66MHz_PCIX_ECC, /* 5 */ PCI_SPEED_100MHz_PCIX_ECC, /* 6 */ PCI_SPEED_133MHz_PCIX_ECC, /* 7 */ PCI_SPEED_UNKNOWN, /* 8 */ PCI_SPEED_66MHz_PCIX_266, /* 9 */ PCI_SPEED_100MHz_PCIX_266, /* A */ PCI_SPEED_133MHz_PCIX_266, /* B */ PCI_SPEED_UNKNOWN, /* C */ PCI_SPEED_66MHz_PCIX_533, /* D */ PCI_SPEED_100MHz_PCIX_533, /* E */ PCI_SPEED_133MHz_PCIX_533 /* F */ }; /* Indexed by PCI_EXP_LNKCAP_SLS, PCI_EXP_LNKSTA_CLS */ const unsigned char pcie_link_speed[] = { PCI_SPEED_UNKNOWN, /* 0 */ PCIE_SPEED_2_5GT, /* 1 */ PCIE_SPEED_5_0GT, /* 2 */ PCIE_SPEED_8_0GT, /* 3 */ PCIE_SPEED_16_0GT, /* 4 */ PCIE_SPEED_32_0GT, /* 5 */ PCIE_SPEED_64_0GT, /* 6 */ PCI_SPEED_UNKNOWN, /* 7 */ PCI_SPEED_UNKNOWN, /* 8 */ PCI_SPEED_UNKNOWN, /* 9 */ PCI_SPEED_UNKNOWN, /* A */ PCI_SPEED_UNKNOWN, /* B */ PCI_SPEED_UNKNOWN, /* C */ PCI_SPEED_UNKNOWN, /* D */ PCI_SPEED_UNKNOWN, /* E */ PCI_SPEED_UNKNOWN /* F */ }; EXPORT_SYMBOL_GPL(pcie_link_speed); const char *pci_speed_string(enum pci_bus_speed speed) { /* Indexed by the pci_bus_speed enum */ static const char *speed_strings[] = { "33 MHz PCI", /* 0x00 */ "66 MHz PCI", /* 0x01 */ "66 MHz PCI-X", /* 0x02 */ "100 MHz PCI-X", /* 0x03 */ "133 MHz PCI-X", /* 0x04 */ NULL, /* 0x05 */ NULL, /* 0x06 */ NULL, /* 0x07 */ NULL, /* 0x08 */ "66 MHz PCI-X 266", /* 0x09 */ "100 MHz PCI-X 266", /* 0x0a */ "133 MHz PCI-X 266", /* 0x0b */ "Unknown AGP", /* 0x0c */ "1x AGP", /* 0x0d */ "2x AGP", /* 0x0e */ "4x AGP", /* 0x0f */ "8x AGP", /* 0x10 */ "66 MHz PCI-X 533", /* 0x11 */ "100 MHz PCI-X 533", /* 0x12 */ "133 MHz PCI-X 533", /* 0x13 */ "2.5 GT/s PCIe", /* 0x14 */ "5.0 GT/s PCIe", /* 0x15 */ "8.0 GT/s PCIe", /* 0x16 */ "16.0 GT/s PCIe", /* 0x17 */ "32.0 GT/s PCIe", /* 0x18 */ "64.0 GT/s PCIe", /* 0x19 */ }; if (speed < ARRAY_SIZE(speed_strings)) return speed_strings[speed]; return "Unknown"; } EXPORT_SYMBOL_GPL(pci_speed_string); void pcie_update_link_speed(struct pci_bus *bus, u16 linksta) { bus->cur_bus_speed = pcie_link_speed[linksta & PCI_EXP_LNKSTA_CLS]; } EXPORT_SYMBOL_GPL(pcie_update_link_speed); static unsigned char agp_speeds[] = { AGP_UNKNOWN, AGP_1X, AGP_2X, AGP_4X, AGP_8X }; static enum pci_bus_speed agp_speed(int agp3, int agpstat) { int index = 0; if (agpstat & 4) index = 3; else if (agpstat & 2) index = 2; else if (agpstat & 1) index = 1; else goto out; if (agp3) { index += 2; if (index == 5) index = 0; } out: return agp_speeds[index]; } static void pci_set_bus_speed(struct pci_bus *bus) { struct pci_dev *bridge = bus->self; int pos; pos = pci_find_capability(bridge, PCI_CAP_ID_AGP); if (!pos) pos = pci_find_capability(bridge, PCI_CAP_ID_AGP3); if (pos) { u32 agpstat, agpcmd; pci_read_config_dword(bridge, pos + PCI_AGP_STATUS, &agpstat); bus->max_bus_speed = agp_speed(agpstat & 8, agpstat & 7); pci_read_config_dword(bridge, pos + PCI_AGP_COMMAND, &agpcmd); bus->cur_bus_speed = agp_speed(agpstat & 8, agpcmd & 7); } pos = pci_find_capability(bridge, PCI_CAP_ID_PCIX); if (pos) { u16 status; enum pci_bus_speed max; pci_read_config_word(bridge, pos + PCI_X_BRIDGE_SSTATUS, &status); if (status & PCI_X_SSTATUS_533MHZ) { max = PCI_SPEED_133MHz_PCIX_533; } else if (status & PCI_X_SSTATUS_266MHZ) { max = PCI_SPEED_133MHz_PCIX_266; } else if (status & PCI_X_SSTATUS_133MHZ) { if ((status & PCI_X_SSTATUS_VERS) == PCI_X_SSTATUS_V2) max = PCI_SPEED_133MHz_PCIX_ECC; else max = PCI_SPEED_133MHz_PCIX; } else { max = PCI_SPEED_66MHz_PCIX; } bus->max_bus_speed = max; bus->cur_bus_speed = pcix_bus_speed[ (status & PCI_X_SSTATUS_FREQ) >> 6]; return; } if (pci_is_pcie(bridge)) { u32 linkcap; u16 linksta; pcie_capability_read_dword(bridge, PCI_EXP_LNKCAP, &linkcap); bus->max_bus_speed = pcie_link_speed[linkcap & PCI_EXP_LNKCAP_SLS]; bridge->link_active_reporting = !!(linkcap & PCI_EXP_LNKCAP_DLLLARC); pcie_capability_read_word(bridge, PCI_EXP_LNKSTA, &linksta); pcie_update_link_speed(bus, linksta); } } static struct irq_domain *pci_host_bridge_msi_domain(struct pci_bus *bus) { struct irq_domain *d; /* If the host bridge driver sets a MSI domain of the bridge, use it */ d = dev_get_msi_domain(bus->bridge); /* * Any firmware interface that can resolve the msi_domain * should be called from here. */ if (!d) d = pci_host_bridge_of_msi_domain(bus); if (!d) d = pci_host_bridge_acpi_msi_domain(bus); #ifdef CONFIG_PCI_MSI_IRQ_DOMAIN /* * If no IRQ domain was found via the OF tree, try looking it up * directly through the fwnode_handle. */ if (!d) { struct fwnode_handle *fwnode = pci_root_bus_fwnode(bus); if (fwnode) d = irq_find_matching_fwnode(fwnode, DOMAIN_BUS_PCI_MSI); } #endif return d; } static void pci_set_bus_msi_domain(struct pci_bus *bus) { struct irq_domain *d; struct pci_bus *b; /* * The bus can be a root bus, a subordinate bus, or a virtual bus * created by an SR-IOV device. Walk up to the first bridge device * found or derive the domain from the host bridge. */ for (b = bus, d = NULL; !d && !pci_is_root_bus(b); b = b->parent) { if (b->self) d = dev_get_msi_domain(&b->self->dev); } if (!d) d = pci_host_bridge_msi_domain(b); dev_set_msi_domain(&bus->dev, d); } static int pci_register_host_bridge(struct pci_host_bridge *bridge) { struct device *parent = bridge->dev.parent; struct resource_entry *window, *next, *n; struct pci_bus *bus, *b; resource_size_t offset, next_offset; LIST_HEAD(resources); struct resource *res, *next_res; char addr[64], *fmt; const char *name; int err; bus = pci_alloc_bus(NULL); if (!bus) return -ENOMEM; bridge->bus = bus; bus->sysdata = bridge->sysdata; bus->ops = bridge->ops; bus->number = bus->busn_res.start = bridge->busnr; #ifdef CONFIG_PCI_DOMAINS_GENERIC if (bridge->domain_nr == PCI_DOMAIN_NR_NOT_SET) bus->domain_nr = pci_bus_find_domain_nr(bus, parent); else bus->domain_nr = bridge->domain_nr; #endif b = pci_find_bus(pci_domain_nr(bus), bridge->busnr); if (b) { /* Ignore it if we already got here via a different bridge */ dev_dbg(&b->dev, "bus already known\n"); err = -EEXIST; goto free; } dev_set_name(&bridge->dev, "pci%04x:%02x", pci_domain_nr(bus), bridge->busnr); err = pcibios_root_bridge_prepare(bridge); if (err) goto free; /* Temporarily move resources off the list */ list_splice_init(&bridge->windows, &resources); err = device_add(&bridge->dev); if (err) { put_device(&bridge->dev); goto free; } bus->bridge = get_device(&bridge->dev); device_enable_async_suspend(bus->bridge); pci_set_bus_of_node(bus); pci_set_bus_msi_domain(bus); if (bridge->msi_domain && !dev_get_msi_domain(&bus->dev) && !pci_host_of_has_msi_map(parent)) bus->bus_flags |= PCI_BUS_FLAGS_NO_MSI; if (!parent) set_dev_node(bus->bridge, pcibus_to_node(bus)); bus->dev.class = &pcibus_class; bus->dev.parent = bus->bridge; dev_set_name(&bus->dev, "%04x:%02x", pci_domain_nr(bus), bus->number); name = dev_name(&bus->dev); err = device_register(&bus->dev); if (err) goto unregister; pcibios_add_bus(bus); if (bus->ops->add_bus) { err = bus->ops->add_bus(bus); if (WARN_ON(err < 0)) dev_err(&bus->dev, "failed to add bus: %d\n", err); } /* Create legacy_io and legacy_mem files for this bus */ pci_create_legacy_files(bus); if (parent) dev_info(parent, "PCI host bridge to bus %s\n", name); else pr_info("PCI host bridge to bus %s\n", name); if (nr_node_ids > 1 && pcibus_to_node(bus) == NUMA_NO_NODE) dev_warn(&bus->dev, "Unknown NUMA node; performance will be reduced\n"); /* Coalesce contiguous windows */ resource_list_for_each_entry_safe(window, n, &resources) { if (list_is_last(&window->node, &resources)) break; next = list_next_entry(window, node); offset = window->offset; res = window->res; next_offset = next->offset; next_res = next->res; if (res->flags != next_res->flags || offset != next_offset) continue; if (res->end + 1 == next_res->start) { next_res->start = res->start; res->flags = res->start = res->end = 0; } } /* Add initial resources to the bus */ resource_list_for_each_entry_safe(window, n, &resources) { offset = window->offset; res = window->res; if (!res->flags && !res->start && !res->end) { release_resource(res); resource_list_destroy_entry(window); continue; } list_move_tail(&window->node, &bridge->windows); if (res->flags & IORESOURCE_BUS) pci_bus_insert_busn_res(bus, bus->number, res->end); else pci_bus_add_resource(bus, res, 0); if (offset) { if (resource_type(res) == IORESOURCE_IO) fmt = " (bus address [%#06llx-%#06llx])"; else fmt = " (bus address [%#010llx-%#010llx])"; snprintf(addr, sizeof(addr), fmt, (unsigned long long)(res->start - offset), (unsigned long long)(res->end - offset)); } else addr[0] = '\0'; dev_info(&bus->dev, "root bus resource %pR%s\n", res, addr); } down_write(&pci_bus_sem); list_add_tail(&bus->node, &pci_root_buses); up_write(&pci_bus_sem); return 0; unregister: put_device(&bridge->dev); device_del(&bridge->dev); free: kfree(bus); return err; } static bool pci_bridge_child_ext_cfg_accessible(struct pci_dev *bridge) { int pos; u32 status; /* * If extended config space isn't accessible on a bridge's primary * bus, we certainly can't access it on the secondary bus. */ if (bridge->bus->bus_flags & PCI_BUS_FLAGS_NO_EXTCFG) return false; /* * PCIe Root Ports and switch ports are PCIe on both sides, so if * extended config space is accessible on the primary, it's also * accessible on the secondary. */ if (pci_is_pcie(bridge) && (pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT || pci_pcie_type(bridge) == PCI_EXP_TYPE_UPSTREAM || pci_pcie_type(bridge) == PCI_EXP_TYPE_DOWNSTREAM)) return true; /* * For the other bridge types: * - PCI-to-PCI bridges * - PCIe-to-PCI/PCI-X forward bridges * - PCI/PCI-X-to-PCIe reverse bridges * extended config space on the secondary side is only accessible * if the bridge supports PCI-X Mode 2. */ pos = pci_find_capability(bridge, PCI_CAP_ID_PCIX); if (!pos) return false; pci_read_config_dword(bridge, pos + PCI_X_STATUS, &status); return status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ); } static struct pci_bus *pci_alloc_child_bus(struct pci_bus *parent, struct pci_dev *bridge, int busnr) { struct pci_bus *child; struct pci_host_bridge *host; int i; int ret; /* Allocate a new bus and inherit stuff from the parent */ child = pci_alloc_bus(parent); if (!child) return NULL; child->parent = parent; child->sysdata = parent->sysdata; child->bus_flags = parent->bus_flags; host = pci_find_host_bridge(parent); if (host->child_ops) child->ops = host->child_ops; else child->ops = parent->ops; /* * Initialize some portions of the bus device, but don't register * it now as the parent is not properly set up yet. */ child->dev.class = &pcibus_class; dev_set_name(&child->dev, "%04x:%02x", pci_domain_nr(child), busnr); /* Set up the primary, secondary and subordinate bus numbers */ child->number = child->busn_res.start = busnr; child->primary = parent->busn_res.start; child->busn_res.end = 0xff; if (!bridge) { child->dev.parent = parent->bridge; goto add_dev; } child->self = bridge; child->bridge = get_device(&bridge->dev); child->dev.parent = child->bridge; pci_set_bus_of_node(child); pci_set_bus_speed(child); /* * Check whether extended config space is accessible on the child * bus. Note that we currently assume it is always accessible on * the root bus. */ if (!pci_bridge_child_ext_cfg_accessible(bridge)) { child->bus_flags |= PCI_BUS_FLAGS_NO_EXTCFG; pci_info(child, "extended config space not accessible\n"); } /* Set up default resource pointers and names */ for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++) { child->resource[i] = &bridge->resource[PCI_BRIDGE_RESOURCES+i]; child->resource[i]->name = child->name; } bridge->subordinate = child; add_dev: pci_set_bus_msi_domain(child); ret = device_register(&child->dev); WARN_ON(ret < 0); pcibios_add_bus(child); if (child->ops->add_bus) { ret = child->ops->add_bus(child); if (WARN_ON(ret < 0)) dev_err(&child->dev, "failed to add bus: %d\n", ret); } /* Create legacy_io and legacy_mem files for this bus */ pci_create_legacy_files(child); return child; } struct pci_bus *pci_add_new_bus(struct pci_bus *parent, struct pci_dev *dev, int busnr) { struct pci_bus *child; child = pci_alloc_child_bus(parent, dev, busnr); if (child) { down_write(&pci_bus_sem); list_add_tail(&child->node, &parent->children); up_write(&pci_bus_sem); } return child; } EXPORT_SYMBOL(pci_add_new_bus); static void pci_enable_crs(struct pci_dev *pdev) { u16 root_cap = 0; /* Enable CRS Software Visibility if supported */ pcie_capability_read_word(pdev, PCI_EXP_RTCAP, &root_cap); if (root_cap & PCI_EXP_RTCAP_CRSVIS) pcie_capability_set_word(pdev, PCI_EXP_RTCTL, PCI_EXP_RTCTL_CRSSVE); } static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus, unsigned int available_buses); /** * pci_ea_fixed_busnrs() - Read fixed Secondary and Subordinate bus * numbers from EA capability. * @dev: Bridge * @sec: updated with secondary bus number from EA * @sub: updated with subordinate bus number from EA * * If @dev is a bridge with EA capability that specifies valid secondary * and subordinate bus numbers, return true with the bus numbers in @sec * and @sub. Otherwise return false. */ static bool pci_ea_fixed_busnrs(struct pci_dev *dev, u8 *sec, u8 *sub) { int ea, offset; u32 dw; u8 ea_sec, ea_sub; if (dev->hdr_type != PCI_HEADER_TYPE_BRIDGE) return false; /* find PCI EA capability in list */ ea = pci_find_capability(dev, PCI_CAP_ID_EA); if (!ea) return false; offset = ea + PCI_EA_FIRST_ENT; pci_read_config_dword(dev, offset, &dw); ea_sec = dw & PCI_EA_SEC_BUS_MASK; ea_sub = (dw & PCI_EA_SUB_BUS_MASK) >> PCI_EA_SUB_BUS_SHIFT; if (ea_sec == 0 || ea_sub < ea_sec) return false; *sec = ea_sec; *sub = ea_sub; return true; } /* * pci_scan_bridge_extend() - Scan buses behind a bridge * @bus: Parent bus the bridge is on * @dev: Bridge itself * @max: Starting subordinate number of buses behind this bridge * @available_buses: Total number of buses available for this bridge and * the devices below. After the minimal bus space has * been allocated the remaining buses will be * distributed equally between hotplug-capable bridges. * @pass: Either %0 (scan already configured bridges) or %1 (scan bridges * that need to be reconfigured. * * If it's a bridge, configure it and scan the bus behind it. * For CardBus bridges, we don't scan behind as the devices will * be handled by the bridge driver itself. * * We need to process bridges in two passes -- first we scan those * already configured by the BIOS and after we are done with all of * them, we proceed to assigning numbers to the remaining buses in * order to avoid overlaps between old and new bus numbers. * * Return: New subordinate number covering all buses behind this bridge. */ static int pci_scan_bridge_extend(struct pci_bus *bus, struct pci_dev *dev, int max, unsigned int available_buses, int pass) { struct pci_bus *child; int is_cardbus = (dev->hdr_type == PCI_HEADER_TYPE_CARDBUS); u32 buses, i, j = 0; u16 bctl; u8 primary, secondary, subordinate; int broken = 0; bool fixed_buses; u8 fixed_sec, fixed_sub; int next_busnr; /* * Make sure the bridge is powered on to be able to access config * space of devices below it. */ pm_runtime_get_sync(&dev->dev); pci_read_config_dword(dev, PCI_PRIMARY_BUS, &buses); primary = buses & 0xFF; secondary = (buses >> 8) & 0xFF; subordinate = (buses >> 16) & 0xFF; pci_dbg(dev, "scanning [bus %02x-%02x] behind bridge, pass %d\n", secondary, subordinate, pass); if (!primary && (primary != bus->number) && secondary && subordinate) { pci_warn(dev, "Primary bus is hard wired to 0\n"); primary = bus->number; } /* Check if setup is sensible at all */ if (!pass && (primary != bus->number || secondary <= bus->number || secondary > subordinate)) { pci_info(dev, "bridge configuration invalid ([bus %02x-%02x]), reconfiguring\n", secondary, subordinate); broken = 1; } /* * Disable Master-Abort Mode during probing to avoid reporting of * bus errors in some architectures. */ pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &bctl); pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl & ~PCI_BRIDGE_CTL_MASTER_ABORT); pci_enable_crs(dev); if ((secondary || subordinate) && !pcibios_assign_all_busses() && !is_cardbus && !broken) { unsigned int cmax, buses; /* * Bus already configured by firmware, process it in the * first pass and just note the configuration. */ if (pass) goto out; /* * The bus might already exist for two reasons: Either we * are rescanning the bus or the bus is reachable through * more than one bridge. The second case can happen with * the i450NX chipset. */ child = pci_find_bus(pci_domain_nr(bus), secondary); if (!child) { child = pci_add_new_bus(bus, dev, secondary); if (!child) goto out; child->primary = primary; pci_bus_insert_busn_res(child, secondary, subordinate); child->bridge_ctl = bctl; } buses = subordinate - secondary; cmax = pci_scan_child_bus_extend(child, buses); if (cmax > subordinate) pci_warn(dev, "bridge has subordinate %02x but max busn %02x\n", subordinate, cmax); /* Subordinate should equal child->busn_res.end */ if (subordinate > max) max = subordinate; } else { /* * We need to assign a number to this bus which we always * do in the second pass. */ if (!pass) { if (pcibios_assign_all_busses() || broken || is_cardbus) /* * Temporarily disable forwarding of the * configuration cycles on all bridges in * this bus segment to avoid possible * conflicts in the second pass between two * bridges programmed with overlapping bus * ranges. */ pci_write_config_dword(dev, PCI_PRIMARY_BUS, buses & ~0xffffff); goto out; } /* Clear errors */ pci_write_config_word(dev, PCI_STATUS, 0xffff); /* Read bus numbers from EA Capability (if present) */ fixed_buses = pci_ea_fixed_busnrs(dev, &fixed_sec, &fixed_sub); if (fixed_buses) next_busnr = fixed_sec; else next_busnr = max + 1; /* * Prevent assigning a bus number that already exists. * This can happen when a bridge is hot-plugged, so in this * case we only re-scan this bus. */ child = pci_find_bus(pci_domain_nr(bus), next_busnr); if (!child) { child = pci_add_new_bus(bus, dev, next_busnr); if (!child) goto out; pci_bus_insert_busn_res(child, next_busnr, bus->busn_res.end); } max++; if (available_buses) available_buses--; buses = (buses & 0xff000000) | ((unsigned int)(child->primary) << 0) | ((unsigned int)(child->busn_res.start) << 8) | ((unsigned int)(child->busn_res.end) << 16); /* * yenta.c forces a secondary latency timer of 176. * Copy that behaviour here. */ if (is_cardbus) { buses &= ~0xff000000; buses |= CARDBUS_LATENCY_TIMER << 24; } /* We need to blast all three values with a single write */ pci_write_config_dword(dev, PCI_PRIMARY_BUS, buses); if (!is_cardbus) { child->bridge_ctl = bctl; max = pci_scan_child_bus_extend(child, available_buses); } else { /* * For CardBus bridges, we leave 4 bus numbers as * cards with a PCI-to-PCI bridge can be inserted * later. */ for (i = 0; i < CARDBUS_RESERVE_BUSNR; i++) { struct pci_bus *parent = bus; if (pci_find_bus(pci_domain_nr(bus), max+i+1)) break; while (parent->parent) { if ((!pcibios_assign_all_busses()) && (parent->busn_res.end > max) && (parent->busn_res.end <= max+i)) { j = 1; } parent = parent->parent; } if (j) { /* * Often, there are two CardBus * bridges -- try to leave one * valid bus number for each one. */ i /= 2; break; } } max += i; } /* * Set subordinate bus number to its real value. * If fixed subordinate bus number exists from EA * capability then use it. */ if (fixed_buses) max = fixed_sub; pci_bus_update_busn_res_end(child, max); pci_write_config_byte(dev, PCI_SUBORDINATE_BUS, max); } sprintf(child->name, (is_cardbus ? "PCI CardBus %04x:%02x" : "PCI Bus %04x:%02x"), pci_domain_nr(bus), child->number); /* Check that all devices are accessible */ while (bus->parent) { if ((child->busn_res.end > bus->busn_res.end) || (child->number > bus->busn_res.end) || (child->number < bus->number) || (child->busn_res.end < bus->number)) { dev_info(&dev->dev, "devices behind bridge are unusable because %pR cannot be assigned for them\n", &child->busn_res); break; } bus = bus->parent; } out: pci_write_config_word(dev, PCI_BRIDGE_CONTROL, bctl); pm_runtime_put(&dev->dev); return max; } /* * pci_scan_bridge() - Scan buses behind a bridge * @bus: Parent bus the bridge is on * @dev: Bridge itself * @max: Starting subordinate number of buses behind this bridge * @pass: Either %0 (scan already configured bridges) or %1 (scan bridges * that need to be reconfigured. * * If it's a bridge, configure it and scan the bus behind it. * For CardBus bridges, we don't scan behind as the devices will * be handled by the bridge driver itself. * * We need to process bridges in two passes -- first we scan those * already configured by the BIOS and after we are done with all of * them, we proceed to assigning numbers to the remaining buses in * order to avoid overlaps between old and new bus numbers. * * Return: New subordinate number covering all buses behind this bridge. */ int pci_scan_bridge(struct pci_bus *bus, struct pci_dev *dev, int max, int pass) { return pci_scan_bridge_extend(bus, dev, max, 0, pass); } EXPORT_SYMBOL(pci_scan_bridge); /* * Read interrupt line and base address registers. * The architecture-dependent code can tweak these, of course. */ static void pci_read_irq(struct pci_dev *dev) { unsigned char irq; /* VFs are not allowed to use INTx, so skip the config reads */ if (dev->is_virtfn) { dev->pin = 0; dev->irq = 0; return; } pci_read_config_byte(dev, PCI_INTERRUPT_PIN, &irq); dev->pin = irq; if (irq) pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq); dev->irq = irq; } void set_pcie_port_type(struct pci_dev *pdev) { int pos; u16 reg16; int type; struct pci_dev *parent; pos = pci_find_capability(pdev, PCI_CAP_ID_EXP); if (!pos) return; pdev->pcie_cap = pos; pci_read_config_word(pdev, pos + PCI_EXP_FLAGS, ®16); pdev->pcie_flags_reg = reg16; pci_read_config_dword(pdev, pos + PCI_EXP_DEVCAP, &pdev->devcap); pdev->pcie_mpss = FIELD_GET(PCI_EXP_DEVCAP_PAYLOAD, pdev->devcap); parent = pci_upstream_bridge(pdev); if (!parent) return; /* * Some systems do not identify their upstream/downstream ports * correctly so detect impossible configurations here and correct * the port type accordingly. */ type = pci_pcie_type(pdev); if (type == PCI_EXP_TYPE_DOWNSTREAM) { /* * If pdev claims to be downstream port but the parent * device is also downstream port assume pdev is actually * upstream port. */ if (pcie_downstream_port(parent)) { pci_info(pdev, "claims to be downstream port but is acting as upstream port, correcting type\n"); pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE; pdev->pcie_flags_reg |= PCI_EXP_TYPE_UPSTREAM; } } else if (type == PCI_EXP_TYPE_UPSTREAM) { /* * If pdev claims to be upstream port but the parent * device is also upstream port assume pdev is actually * downstream port. */ if (pci_pcie_type(parent) == PCI_EXP_TYPE_UPSTREAM) { pci_info(pdev, "claims to be upstream port but is acting as downstream port, correcting type\n"); pdev->pcie_flags_reg &= ~PCI_EXP_FLAGS_TYPE; pdev->pcie_flags_reg |= PCI_EXP_TYPE_DOWNSTREAM; } } } void set_pcie_hotplug_bridge(struct pci_dev *pdev) { u32 reg32; pcie_capability_read_dword(pdev, PCI_EXP_SLTCAP, ®32); if (reg32 & PCI_EXP_SLTCAP_HPC) pdev->is_hotplug_bridge = 1; } static void set_pcie_thunderbolt(struct pci_dev *dev) { u16 vsec; /* Is the device part of a Thunderbolt controller? */ vsec = pci_find_vsec_capability(dev, PCI_VENDOR_ID_INTEL, PCI_VSEC_ID_INTEL_TBT); if (vsec) dev->is_thunderbolt = 1; } static void set_pcie_untrusted(struct pci_dev *dev) { struct pci_dev *parent; /* * If the upstream bridge is untrusted we treat this device * untrusted as well. */ parent = pci_upstream_bridge(dev); if (parent && (parent->untrusted || parent->external_facing)) dev->untrusted = true; } static void pci_set_removable(struct pci_dev *dev) { struct pci_dev *parent = pci_upstream_bridge(dev); /* * We (only) consider everything downstream from an external_facing * device to be removable by the user. We're mainly concerned with * consumer platforms with user accessible thunderbolt ports that are * vulnerable to DMA attacks, and we expect those ports to be marked by * the firmware as external_facing. Devices in traditional hotplug * slots can technically be removed, but the expectation is that unless * the port is marked with external_facing, such devices are less * accessible to user / may not be removed by end user, and thus not * exposed as "removable" to userspace. */ if (parent && (parent->external_facing || dev_is_removable(&parent->dev))) dev_set_removable(&dev->dev, DEVICE_REMOVABLE); } /** * pci_ext_cfg_is_aliased - Is ext config space just an alias of std config? * @dev: PCI device * * PCI Express to PCI/PCI-X Bridge Specification, rev 1.0, 4.1.4 says that * when forwarding a type1 configuration request the bridge must check that * the extended register address field is zero. The bridge is not permitted * to forward the transactions and must handle it as an Unsupported Request. * Some bridges do not follow this rule and simply drop the extended register * bits, resulting in the standard config space being aliased, every 256 * bytes across the entire configuration space. Test for this condition by * comparing the first dword of each potential alias to the vendor/device ID. * Known offenders: * ASM1083/1085 PCIe-to-PCI Reversible Bridge (1b21:1080, rev 01 & 03) * AMD/ATI SBx00 PCI to PCI Bridge (1002:4384, rev 40) */ static bool pci_ext_cfg_is_aliased(struct pci_dev *dev) { #ifdef CONFIG_PCI_QUIRKS int pos; u32 header, tmp; pci_read_config_dword(dev, PCI_VENDOR_ID, &header); for (pos = PCI_CFG_SPACE_SIZE; pos < PCI_CFG_SPACE_EXP_SIZE; pos += PCI_CFG_SPACE_SIZE) { if (pci_read_config_dword(dev, pos, &tmp) != PCIBIOS_SUCCESSFUL || header != tmp) return false; } return true; #else return false; #endif } /** * pci_cfg_space_size_ext - Get the configuration space size of the PCI device * @dev: PCI device * * Regular PCI devices have 256 bytes, but PCI-X 2 and PCI Express devices * have 4096 bytes. Even if the device is capable, that doesn't mean we can * access it. Maybe we don't have a way to generate extended config space * accesses, or the device is behind a reverse Express bridge. So we try * reading the dword at 0x100 which must either be 0 or a valid extended * capability header. */ static int pci_cfg_space_size_ext(struct pci_dev *dev) { u32 status; int pos = PCI_CFG_SPACE_SIZE; if (pci_read_config_dword(dev, pos, &status) != PCIBIOS_SUCCESSFUL) return PCI_CFG_SPACE_SIZE; if (PCI_POSSIBLE_ERROR(status) || pci_ext_cfg_is_aliased(dev)) return PCI_CFG_SPACE_SIZE; return PCI_CFG_SPACE_EXP_SIZE; } int pci_cfg_space_size(struct pci_dev *dev) { int pos; u32 status; u16 class; #ifdef CONFIG_PCI_IOV /* * Per the SR-IOV specification (rev 1.1, sec 3.5), VFs are required to * implement a PCIe capability and therefore must implement extended * config space. We can skip the NO_EXTCFG test below and the * reachability/aliasing test in pci_cfg_space_size_ext() by virtue of * the fact that the SR-IOV capability on the PF resides in extended * config space and must be accessible and non-aliased to have enabled * support for this VF. This is a micro performance optimization for * systems supporting many VFs. */ if (dev->is_virtfn) return PCI_CFG_SPACE_EXP_SIZE; #endif if (dev->bus->bus_flags & PCI_BUS_FLAGS_NO_EXTCFG) return PCI_CFG_SPACE_SIZE; class = dev->class >> 8; if (class == PCI_CLASS_BRIDGE_HOST) return pci_cfg_space_size_ext(dev); if (pci_is_pcie(dev)) return pci_cfg_space_size_ext(dev); pos = pci_find_capability(dev, PCI_CAP_ID_PCIX); if (!pos) return PCI_CFG_SPACE_SIZE; pci_read_config_dword(dev, pos + PCI_X_STATUS, &status); if (status & (PCI_X_STATUS_266MHZ | PCI_X_STATUS_533MHZ)) return pci_cfg_space_size_ext(dev); return PCI_CFG_SPACE_SIZE; } static u32 pci_class(struct pci_dev *dev) { u32 class; #ifdef CONFIG_PCI_IOV if (dev->is_virtfn) return dev->physfn->sriov->class; #endif pci_read_config_dword(dev, PCI_CLASS_REVISION, &class); return class; } static void pci_subsystem_ids(struct pci_dev *dev, u16 *vendor, u16 *device) { #ifdef CONFIG_PCI_IOV if (dev->is_virtfn) { *vendor = dev->physfn->sriov->subsystem_vendor; *device = dev->physfn->sriov->subsystem_device; return; } #endif pci_read_config_word(dev, PCI_SUBSYSTEM_VENDOR_ID, vendor); pci_read_config_word(dev, PCI_SUBSYSTEM_ID, device); } static u8 pci_hdr_type(struct pci_dev *dev) { u8 hdr_type; #ifdef CONFIG_PCI_IOV if (dev->is_virtfn) return dev->physfn->sriov->hdr_type; #endif pci_read_config_byte(dev, PCI_HEADER_TYPE, &hdr_type); return hdr_type; } #define LEGACY_IO_RESOURCE (IORESOURCE_IO | IORESOURCE_PCI_FIXED) /** * pci_intx_mask_broken - Test PCI_COMMAND_INTX_DISABLE writability * @dev: PCI device * * Test whether PCI_COMMAND_INTX_DISABLE is writable for @dev. Check this * at enumeration-time to avoid modifying PCI_COMMAND at run-time. */ static int pci_intx_mask_broken(struct pci_dev *dev) { u16 orig, toggle, new; pci_read_config_word(dev, PCI_COMMAND, &orig); toggle = orig ^ PCI_COMMAND_INTX_DISABLE; pci_write_config_word(dev, PCI_COMMAND, toggle); pci_read_config_word(dev, PCI_COMMAND, &new); pci_write_config_word(dev, PCI_COMMAND, orig); /* * PCI_COMMAND_INTX_DISABLE was reserved and read-only prior to PCI * r2.3, so strictly speaking, a device is not *broken* if it's not * writable. But we'll live with the misnomer for now. */ if (new != toggle) return 1; return 0; } static void early_dump_pci_device(struct pci_dev *pdev) { u32 value[256 / 4]; int i; pci_info(pdev, "config space:\n"); for (i = 0; i < 256; i += 4) pci_read_config_dword(pdev, i, &value[i / 4]); print_hex_dump(KERN_INFO, "", DUMP_PREFIX_OFFSET, 16, 1, value, 256, false); } /** * pci_setup_device - Fill in class and map information of a device * @dev: the device structure to fill * * Initialize the device structure with information about the device's * vendor,class,memory and IO-space addresses, IRQ lines etc. * Called at initialisation of the PCI subsystem and by CardBus services. * Returns 0 on success and negative if unknown type of device (not normal, * bridge or CardBus). */ int pci_setup_device(struct pci_dev *dev) { u32 class; u16 cmd; u8 hdr_type; int pos = 0; struct pci_bus_region region; struct resource *res; hdr_type = pci_hdr_type(dev); dev->sysdata = dev->bus->sysdata; dev->dev.parent = dev->bus->bridge; dev->dev.bus = &pci_bus_type; dev->hdr_type = hdr_type & 0x7f; dev->multifunction = !!(hdr_type & 0x80); dev->error_state = pci_channel_io_normal; set_pcie_port_type(dev); pci_set_of_node(dev); pci_set_acpi_fwnode(dev); pci_dev_assign_slot(dev); /* * Assume 32-bit PCI; let 64-bit PCI cards (which are far rarer) * set this higher, assuming the system even supports it. */ dev->dma_mask = 0xffffffff; dev_set_name(&dev->dev, "%04x:%02x:%02x.%d", pci_domain_nr(dev->bus), dev->bus->number, PCI_SLOT(dev->devfn), PCI_FUNC(dev->devfn)); class = pci_class(dev); dev->revision = class & 0xff; dev->class = class >> 8; /* upper 3 bytes */ if (pci_early_dump) early_dump_pci_device(dev); /* Need to have dev->class ready */ dev->cfg_size = pci_cfg_space_size(dev); /* Need to have dev->cfg_size ready */ set_pcie_thunderbolt(dev); set_pcie_untrusted(dev); /* "Unknown power state" */ dev->current_state = PCI_UNKNOWN; /* Early fixups, before probing the BARs */ pci_fixup_device(pci_fixup_early, dev); pci_set_removable(dev); pci_info(dev, "[%04x:%04x] type %02x class %#08x\n", dev->vendor, dev->device, dev->hdr_type, dev->class); /* Device class may be changed after fixup */ class = dev->class >> 8; if (dev->non_compliant_bars && !dev->mmio_always_on) { pci_read_config_word(dev, PCI_COMMAND, &cmd); if (cmd & (PCI_COMMAND_IO | PCI_COMMAND_MEMORY)) { pci_info(dev, "device has non-compliant BARs; disabling IO/MEM decoding\n"); cmd &= ~PCI_COMMAND_IO; cmd &= ~PCI_COMMAND_MEMORY; pci_write_config_word(dev, PCI_COMMAND, cmd); } } dev->broken_intx_masking = pci_intx_mask_broken(dev); switch (dev->hdr_type) { /* header type */ case PCI_HEADER_TYPE_NORMAL: /* standard header */ if (class == PCI_CLASS_BRIDGE_PCI) goto bad; pci_read_irq(dev); pci_read_bases(dev, 6, PCI_ROM_ADDRESS); pci_subsystem_ids(dev, &dev->subsystem_vendor, &dev->subsystem_device); /* * Do the ugly legacy mode stuff here rather than broken chip * quirk code. Legacy mode ATA controllers have fixed * addresses. These are not always echoed in BAR0-3, and * BAR0-3 in a few cases contain junk! */ if (class == PCI_CLASS_STORAGE_IDE) { u8 progif; pci_read_config_byte(dev, PCI_CLASS_PROG, &progif); if ((progif & 1) == 0) { region.start = 0x1F0; region.end = 0x1F7; res = &dev->resource[0]; res->flags = LEGACY_IO_RESOURCE; pcibios_bus_to_resource(dev->bus, res, ®ion); pci_info(dev, "legacy IDE quirk: reg 0x10: %pR\n", res); region.start = 0x3F6; region.end = 0x3F6; res = &dev->resource[1]; res->flags = LEGACY_IO_RESOURCE; pcibios_bus_to_resource(dev->bus, res, ®ion); pci_info(dev, "legacy IDE quirk: reg 0x14: %pR\n", res); } if ((progif & 4) == 0) { region.start = 0x170; region.end = 0x177; res = &dev->resource[2]; res->flags = LEGACY_IO_RESOURCE; pcibios_bus_to_resource(dev->bus, res, ®ion); pci_info(dev, "legacy IDE quirk: reg 0x18: %pR\n", res); region.start = 0x376; region.end = 0x376; res = &dev->resource[3]; res->flags = LEGACY_IO_RESOURCE; pcibios_bus_to_resource(dev->bus, res, ®ion); pci_info(dev, "legacy IDE quirk: reg 0x1c: %pR\n", res); } } break; case PCI_HEADER_TYPE_BRIDGE: /* bridge header */ /* * The PCI-to-PCI bridge spec requires that subtractive * decoding (i.e. transparent) bridge must have programming * interface code of 0x01. */ pci_read_irq(dev); dev->transparent = ((dev->class & 0xff) == 1); pci_read_bases(dev, 2, PCI_ROM_ADDRESS1); pci_read_bridge_windows(dev); set_pcie_hotplug_bridge(dev); pos = pci_find_capability(dev, PCI_CAP_ID_SSVID); if (pos) { pci_read_config_word(dev, pos + PCI_SSVID_VENDOR_ID, &dev->subsystem_vendor); pci_read_config_word(dev, pos + PCI_SSVID_DEVICE_ID, &dev->subsystem_device); } break; case PCI_HEADER_TYPE_CARDBUS: /* CardBus bridge header */ if (class != PCI_CLASS_BRIDGE_CARDBUS) goto bad; pci_read_irq(dev); pci_read_bases(dev, 1, 0); pci_read_config_word(dev, PCI_CB_SUBSYSTEM_VENDOR_ID, &dev->subsystem_vendor); pci_read_config_word(dev, PCI_CB_SUBSYSTEM_ID, &dev->subsystem_device); break; default: /* unknown header */ pci_err(dev, "unknown header type %02x, ignoring device\n", dev->hdr_type); pci_release_of_node(dev); return -EIO; bad: pci_err(dev, "ignoring class %#08x (doesn't match header type %02x)\n", dev->class, dev->hdr_type); dev->class = PCI_CLASS_NOT_DEFINED << 8; } /* We found a fine healthy device, go go go... */ return 0; } static void pci_configure_mps(struct pci_dev *dev) { struct pci_dev *bridge = pci_upstream_bridge(dev); int mps, mpss, p_mps, rc; if (!pci_is_pcie(dev)) return; /* MPS and MRRS fields are of type 'RsvdP' for VFs, short-circuit out */ if (dev->is_virtfn) return; /* * For Root Complex Integrated Endpoints, program the maximum * supported value unless limited by the PCIE_BUS_PEER2PEER case. */ if (pci_pcie_type(dev) == PCI_EXP_TYPE_RC_END) { if (pcie_bus_config == PCIE_BUS_PEER2PEER) mps = 128; else mps = 128 << dev->pcie_mpss; rc = pcie_set_mps(dev, mps); if (rc) { pci_warn(dev, "can't set Max Payload Size to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n", mps); } return; } if (!bridge || !pci_is_pcie(bridge)) return; mps = pcie_get_mps(dev); p_mps = pcie_get_mps(bridge); if (mps == p_mps) return; if (pcie_bus_config == PCIE_BUS_TUNE_OFF) { pci_warn(dev, "Max Payload Size %d, but upstream %s set to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n", mps, pci_name(bridge), p_mps); return; } /* * Fancier MPS configuration is done later by * pcie_bus_configure_settings() */ if (pcie_bus_config != PCIE_BUS_DEFAULT) return; mpss = 128 << dev->pcie_mpss; if (mpss < p_mps && pci_pcie_type(bridge) == PCI_EXP_TYPE_ROOT_PORT) { pcie_set_mps(bridge, mpss); pci_info(dev, "Upstream bridge's Max Payload Size set to %d (was %d, max %d)\n", mpss, p_mps, 128 << bridge->pcie_mpss); p_mps = pcie_get_mps(bridge); } rc = pcie_set_mps(dev, p_mps); if (rc) { pci_warn(dev, "can't set Max Payload Size to %d; if necessary, use \"pci=pcie_bus_safe\" and report a bug\n", p_mps); return; } pci_info(dev, "Max Payload Size set to %d (was %d, max %d)\n", p_mps, mps, mpss); } int pci_configure_extended_tags(struct pci_dev *dev, void *ign) { struct pci_host_bridge *host; u32 cap; u16 ctl; int ret; if (!pci_is_pcie(dev)) return 0; ret = pcie_capability_read_dword(dev, PCI_EXP_DEVCAP, &cap); if (ret) return 0; if (!(cap & PCI_EXP_DEVCAP_EXT_TAG)) return 0; ret = pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &ctl); if (ret) return 0; host = pci_find_host_bridge(dev->bus); if (!host) return 0; /* * If some device in the hierarchy doesn't handle Extended Tags * correctly, make sure they're disabled. */ if (host->no_ext_tags) { if (ctl & PCI_EXP_DEVCTL_EXT_TAG) { pci_info(dev, "disabling Extended Tags\n"); pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_EXT_TAG); } return 0; } if (!(ctl & PCI_EXP_DEVCTL_EXT_TAG)) { pci_info(dev, "enabling Extended Tags\n"); pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_EXT_TAG); } return 0; } /** * pcie_relaxed_ordering_enabled - Probe for PCIe relaxed ordering enable * @dev: PCI device to query * * Returns true if the device has enabled relaxed ordering attribute. */ bool pcie_relaxed_ordering_enabled(struct pci_dev *dev) { u16 v; pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &v); return !!(v & PCI_EXP_DEVCTL_RELAX_EN); } EXPORT_SYMBOL(pcie_relaxed_ordering_enabled); static void pci_configure_relaxed_ordering(struct pci_dev *dev) { struct pci_dev *root; /* PCI_EXP_DEVICE_RELAX_EN is RsvdP in VFs */ if (dev->is_virtfn) return; if (!pcie_relaxed_ordering_enabled(dev)) return; /* * For now, we only deal with Relaxed Ordering issues with Root * Ports. Peer-to-Peer DMA is another can of worms. */ root = pcie_find_root_port(dev); if (!root) return; if (root->dev_flags & PCI_DEV_FLAGS_NO_RELAXED_ORDERING) { pcie_capability_clear_word(dev, PCI_EXP_DEVCTL, PCI_EXP_DEVCTL_RELAX_EN); pci_info(dev, "Relaxed Ordering disabled because the Root Port didn't support it\n"); } } static void pci_configure_ltr(struct pci_dev *dev) { #ifdef CONFIG_PCIEASPM struct pci_host_bridge *host = pci_find_host_bridge(dev->bus); struct pci_dev *bridge; u32 cap, ctl; if (!pci_is_pcie(dev)) return; /* Read L1 PM substate capabilities */ dev->l1ss = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_L1SS); pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap); if (!(cap & PCI_EXP_DEVCAP2_LTR)) return; pcie_capability_read_dword(dev, PCI_EXP_DEVCTL2, &ctl); if (ctl & PCI_EXP_DEVCTL2_LTR_EN) { if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) { dev->ltr_path = 1; return; } bridge = pci_upstream_bridge(dev); if (bridge && bridge->ltr_path) dev->ltr_path = 1; return; } if (!host->native_ltr) return; /* * Software must not enable LTR in an Endpoint unless the Root * Complex and all intermediate Switches indicate support for LTR. * PCIe r4.0, sec 6.18. */ if (pci_pcie_type(dev) == PCI_EXP_TYPE_ROOT_PORT) { pcie_capability_set_word(dev, PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_LTR_EN); dev->ltr_path = 1; return; } /* * If we're configuring a hot-added device, LTR was likely * disabled in the upstream bridge, so re-enable it before enabling * it in the new device. */ bridge = pci_upstream_bridge(dev); if (bridge && bridge->ltr_path) { pci_bridge_reconfigure_ltr(dev); pcie_capability_set_word(dev, PCI_EXP_DEVCTL2, PCI_EXP_DEVCTL2_LTR_EN); dev->ltr_path = 1; } #endif } static void pci_configure_eetlp_prefix(struct pci_dev *dev) { #ifdef CONFIG_PCI_PASID struct pci_dev *bridge; int pcie_type; u32 cap; if (!pci_is_pcie(dev)) return; pcie_capability_read_dword(dev, PCI_EXP_DEVCAP2, &cap); if (!(cap & PCI_EXP_DEVCAP2_EE_PREFIX)) return; pcie_type = pci_pcie_type(dev); if (pcie_type == PCI_EXP_TYPE_ROOT_PORT || pcie_type == PCI_EXP_TYPE_RC_END) dev->eetlp_prefix_path = 1; else { bridge = pci_upstream_bridge(dev); if (bridge && bridge->eetlp_prefix_path) dev->eetlp_prefix_path = 1; } #endif } static void pci_configure_serr(struct pci_dev *dev) { u16 control; if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { /* * A bridge will not forward ERR_ messages coming from an * endpoint unless SERR# forwarding is enabled. */ pci_read_config_word(dev, PCI_BRIDGE_CONTROL, &control); if (!(control & PCI_BRIDGE_CTL_SERR)) { control |= PCI_BRIDGE_CTL_SERR; pci_write_config_word(dev, PCI_BRIDGE_CONTROL, control); } } } static void pci_configure_device(struct pci_dev *dev) { pci_configure_mps(dev); pci_configure_extended_tags(dev, NULL); pci_configure_relaxed_ordering(dev); pci_configure_ltr(dev); pci_configure_eetlp_prefix(dev); pci_configure_serr(dev); pci_acpi_program_hp_params(dev); } static void pci_release_capabilities(struct pci_dev *dev) { pci_aer_exit(dev); pci_rcec_exit(dev); pci_iov_release(dev); pci_free_cap_save_buffers(dev); } /** * pci_release_dev - Free a PCI device structure when all users of it are * finished * @dev: device that's been disconnected * * Will be called only by the device core when all users of this PCI device are * done. */ static void pci_release_dev(struct device *dev) { struct pci_dev *pci_dev; pci_dev = to_pci_dev(dev); pci_release_capabilities(pci_dev); pci_release_of_node(pci_dev); pcibios_release_device(pci_dev); pci_bus_put(pci_dev->bus); kfree(pci_dev->driver_override); bitmap_free(pci_dev->dma_alias_mask); dev_dbg(dev, "device released\n"); kfree(pci_dev); } struct pci_dev *pci_alloc_dev(struct pci_bus *bus) { struct pci_dev *dev; dev = kzalloc(sizeof(struct pci_dev), GFP_KERNEL); if (!dev) return NULL; INIT_LIST_HEAD(&dev->bus_list); dev->dev.type = &pci_dev_type; dev->bus = pci_bus_get(bus); dev->driver_exclusive_resource = (struct resource) { .name = "PCI Exclusive", .start = 0, .end = -1, }; spin_lock_init(&dev->pcie_cap_lock); #ifdef CONFIG_PCI_MSI raw_spin_lock_init(&dev->msi_lock); #endif return dev; } EXPORT_SYMBOL(pci_alloc_dev); static bool pci_bus_crs_vendor_id(u32 l) { return (l & 0xffff) == PCI_VENDOR_ID_PCI_SIG; } static bool pci_bus_wait_crs(struct pci_bus *bus, int devfn, u32 *l, int timeout) { int delay = 1; if (!pci_bus_crs_vendor_id(*l)) return true; /* not a CRS completion */ if (!timeout) return false; /* CRS, but caller doesn't want to wait */ /* * We got the reserved Vendor ID that indicates a completion with * Configuration Request Retry Status (CRS). Retry until we get a * valid Vendor ID or we time out. */ while (pci_bus_crs_vendor_id(*l)) { if (delay > timeout) { pr_warn("pci %04x:%02x:%02x.%d: not ready after %dms; giving up\n", pci_domain_nr(bus), bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1); return false; } if (delay >= 1000) pr_info("pci %04x:%02x:%02x.%d: not ready after %dms; waiting\n", pci_domain_nr(bus), bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1); msleep(delay); delay *= 2; if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l)) return false; } if (delay >= 1000) pr_info("pci %04x:%02x:%02x.%d: ready after %dms\n", pci_domain_nr(bus), bus->number, PCI_SLOT(devfn), PCI_FUNC(devfn), delay - 1); return true; } bool pci_bus_generic_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, int timeout) { if (pci_bus_read_config_dword(bus, devfn, PCI_VENDOR_ID, l)) return false; /* Some broken boards return 0 or ~0 (PCI_ERROR_RESPONSE) if a slot is empty: */ if (PCI_POSSIBLE_ERROR(*l) || *l == 0x00000000 || *l == 0x0000ffff || *l == 0xffff0000) return false; if (pci_bus_crs_vendor_id(*l)) return pci_bus_wait_crs(bus, devfn, l, timeout); return true; } bool pci_bus_read_dev_vendor_id(struct pci_bus *bus, int devfn, u32 *l, int timeout) { #ifdef CONFIG_PCI_QUIRKS struct pci_dev *bridge = bus->self; /* * Certain IDT switches have an issue where they improperly trigger * ACS Source Validation errors on completions for config reads. */ if (bridge && bridge->vendor == PCI_VENDOR_ID_IDT && bridge->device == 0x80b5) return pci_idt_bus_quirk(bus, devfn, l, timeout); #endif return pci_bus_generic_read_dev_vendor_id(bus, devfn, l, timeout); } EXPORT_SYMBOL(pci_bus_read_dev_vendor_id); /* * Read the config data for a PCI device, sanity-check it, * and fill in the dev structure. */ static struct pci_dev *pci_scan_device(struct pci_bus *bus, int devfn) { struct pci_dev *dev; u32 l; if (!pci_bus_read_dev_vendor_id(bus, devfn, &l, 60*1000)) return NULL; dev = pci_alloc_dev(bus); if (!dev) return NULL; dev->devfn = devfn; dev->vendor = l & 0xffff; dev->device = (l >> 16) & 0xffff; if (pci_setup_device(dev)) { pci_bus_put(dev->bus); kfree(dev); return NULL; } return dev; } void pcie_report_downtraining(struct pci_dev *dev) { if (!pci_is_pcie(dev)) return; /* Look from the device up to avoid downstream ports with no devices */ if ((pci_pcie_type(dev) != PCI_EXP_TYPE_ENDPOINT) && (pci_pcie_type(dev) != PCI_EXP_TYPE_LEG_END) && (pci_pcie_type(dev) != PCI_EXP_TYPE_UPSTREAM)) return; /* Multi-function PCIe devices share the same link/status */ if (PCI_FUNC(dev->devfn) != 0 || dev->is_virtfn) return; /* Print link status only if the device is constrained by the fabric */ __pcie_print_link_status(dev, false); } static void pci_init_capabilities(struct pci_dev *dev) { pci_ea_init(dev); /* Enhanced Allocation */ pci_msi_init(dev); /* Disable MSI */ pci_msix_init(dev); /* Disable MSI-X */ /* Buffers for saving PCIe and PCI-X capabilities */ pci_allocate_cap_save_buffers(dev); pci_pm_init(dev); /* Power Management */ pci_vpd_init(dev); /* Vital Product Data */ pci_configure_ari(dev); /* Alternative Routing-ID Forwarding */ pci_iov_init(dev); /* Single Root I/O Virtualization */ pci_ats_init(dev); /* Address Translation Services */ pci_pri_init(dev); /* Page Request Interface */ pci_pasid_init(dev); /* Process Address Space ID */ pci_acs_init(dev); /* Access Control Services */ pci_ptm_init(dev); /* Precision Time Measurement */ pci_aer_init(dev); /* Advanced Error Reporting */ pci_dpc_init(dev); /* Downstream Port Containment */ pci_rcec_init(dev); /* Root Complex Event Collector */ pcie_report_downtraining(dev); pci_init_reset_methods(dev); } /* * This is the equivalent of pci_host_bridge_msi_domain() that acts on * devices. Firmware interfaces that can select the MSI domain on a * per-device basis should be called from here. */ static struct irq_domain *pci_dev_msi_domain(struct pci_dev *dev) { struct irq_domain *d; /* * If a domain has been set through the pcibios_device_add() * callback, then this is the one (platform code knows best). */ d = dev_get_msi_domain(&dev->dev); if (d) return d; /* * Let's see if we have a firmware interface able to provide * the domain. */ d = pci_msi_get_device_domain(dev); if (d) return d; return NULL; } static void pci_set_msi_domain(struct pci_dev *dev) { struct irq_domain *d; /* * If the platform or firmware interfaces cannot supply a * device-specific MSI domain, then inherit the default domain * from the host bridge itself. */ d = pci_dev_msi_domain(dev); if (!d) d = dev_get_msi_domain(&dev->bus->dev); dev_set_msi_domain(&dev->dev, d); } void pci_device_add(struct pci_dev *dev, struct pci_bus *bus) { int ret; pci_configure_device(dev); device_initialize(&dev->dev); dev->dev.release = pci_release_dev; set_dev_node(&dev->dev, pcibus_to_node(bus)); dev->dev.dma_mask = &dev->dma_mask; dev->dev.dma_parms = &dev->dma_parms; dev->dev.coherent_dma_mask = 0xffffffffull; dma_set_max_seg_size(&dev->dev, 65536); dma_set_seg_boundary(&dev->dev, 0xffffffff); /* Fix up broken headers */ pci_fixup_device(pci_fixup_header, dev); pci_reassigndev_resource_alignment(dev); dev->state_saved = false; pci_init_capabilities(dev); /* * Add the device to our list of discovered devices * and the bus list for fixup functions, etc. */ down_write(&pci_bus_sem); list_add_tail(&dev->bus_list, &bus->devices); up_write(&pci_bus_sem); ret = pcibios_device_add(dev); WARN_ON(ret < 0); /* Set up MSI IRQ domain */ pci_set_msi_domain(dev); /* Notifier could use PCI capabilities */ dev->match_driver = false; ret = device_add(&dev->dev); WARN_ON(ret < 0); } struct pci_dev *pci_scan_single_device(struct pci_bus *bus, int devfn) { struct pci_dev *dev; dev = pci_get_slot(bus, devfn); if (dev) { pci_dev_put(dev); return dev; } dev = pci_scan_device(bus, devfn); if (!dev) return NULL; pci_device_add(dev, bus); return dev; } EXPORT_SYMBOL(pci_scan_single_device); static int next_ari_fn(struct pci_bus *bus, struct pci_dev *dev, int fn) { int pos; u16 cap = 0; unsigned int next_fn; if (!dev) return -ENODEV; pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ARI); if (!pos) return -ENODEV; pci_read_config_word(dev, pos + PCI_ARI_CAP, &cap); next_fn = PCI_ARI_CAP_NFN(cap); if (next_fn <= fn) return -ENODEV; /* protect against malformed list */ return next_fn; } static int next_fn(struct pci_bus *bus, struct pci_dev *dev, int fn) { if (pci_ari_enabled(bus)) return next_ari_fn(bus, dev, fn); if (fn >= 7) return -ENODEV; /* only multifunction devices may have more functions */ if (dev && !dev->multifunction) return -ENODEV; return fn + 1; } static int only_one_child(struct pci_bus *bus) { struct pci_dev *bridge = bus->self; /* * Systems with unusual topologies set PCI_SCAN_ALL_PCIE_DEVS so * we scan for all possible devices, not just Device 0. */ if (pci_has_flag(PCI_SCAN_ALL_PCIE_DEVS)) return 0; /* * A PCIe Downstream Port normally leads to a Link with only Device * 0 on it (PCIe spec r3.1, sec 7.3.1). As an optimization, scan * only for Device 0 in that situation. */ if (bridge && pci_is_pcie(bridge) && pcie_downstream_port(bridge)) return 1; return 0; } /** * pci_scan_slot - Scan a PCI slot on a bus for devices * @bus: PCI bus to scan * @devfn: slot number to scan (must have zero function) * * Scan a PCI slot on the specified PCI bus for devices, adding * discovered devices to the @bus->devices list. New devices * will not have is_added set. * * Returns the number of new devices found. */ int pci_scan_slot(struct pci_bus *bus, int devfn) { struct pci_dev *dev; int fn = 0, nr = 0; if (only_one_child(bus) && (devfn > 0)) return 0; /* Already scanned the entire slot */ do { dev = pci_scan_single_device(bus, devfn + fn); if (dev) { if (!pci_dev_is_added(dev)) nr++; if (fn > 0) dev->multifunction = 1; } else if (fn == 0) { /* * Function 0 is required unless we are running on * a hypervisor that passes through individual PCI * functions. */ if (!hypervisor_isolated_pci_functions()) break; } fn = next_fn(bus, dev, fn); } while (fn >= 0); /* Only one slot has PCIe device */ if (bus->self && nr) pcie_aspm_init_link_state(bus->self); return nr; } EXPORT_SYMBOL(pci_scan_slot); static int pcie_find_smpss(struct pci_dev *dev, void *data) { u8 *smpss = data; if (!pci_is_pcie(dev)) return 0; /* * We don't have a way to change MPS settings on devices that have * drivers attached. A hot-added device might support only the minimum * MPS setting (MPS=128). Therefore, if the fabric contains a bridge * where devices may be hot-added, we limit the fabric MPS to 128 so * hot-added devices will work correctly. * * However, if we hot-add a device to a slot directly below a Root * Port, it's impossible for there to be other existing devices below * the port. We don't limit the MPS in this case because we can * reconfigure MPS on both the Root Port and the hot-added device, * and there are no other devices involved. * * Note that this PCIE_BUS_SAFE path assumes no peer-to-peer DMA. */ if (dev->is_hotplug_bridge && pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT) *smpss = 0; if (*smpss > dev->pcie_mpss) *smpss = dev->pcie_mpss; return 0; } static void pcie_write_mps(struct pci_dev *dev, int mps) { int rc; if (pcie_bus_config == PCIE_BUS_PERFORMANCE) { mps = 128 << dev->pcie_mpss; if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT && dev->bus->self) /* * For "Performance", the assumption is made that * downstream communication will never be larger than * the MRRS. So, the MPS only needs to be configured * for the upstream communication. This being the case, * walk from the top down and set the MPS of the child * to that of the parent bus. * * Configure the device MPS with the smaller of the * device MPSS or the bridge MPS (which is assumed to be * properly configured at this point to the largest * allowable MPS based on its parent bus). */ mps = min(mps, pcie_get_mps(dev->bus->self)); } rc = pcie_set_mps(dev, mps); if (rc) pci_err(dev, "Failed attempting to set the MPS\n"); } static void pcie_write_mrrs(struct pci_dev *dev) { int rc, mrrs; /* * In the "safe" case, do not configure the MRRS. There appear to be * issues with setting MRRS to 0 on a number of devices. */ if (pcie_bus_config != PCIE_BUS_PERFORMANCE) return; /* * For max performance, the MRRS must be set to the largest supported * value. However, it cannot be configured larger than the MPS the * device or the bus can support. This should already be properly * configured by a prior call to pcie_write_mps(). */ mrrs = pcie_get_mps(dev); /* * MRRS is a R/W register. Invalid values can be written, but a * subsequent read will verify if the value is acceptable or not. * If the MRRS value provided is not acceptable (e.g., too large), * shrink the value until it is acceptable to the HW. */ while (mrrs != pcie_get_readrq(dev) && mrrs >= 128) { rc = pcie_set_readrq(dev, mrrs); if (!rc) break; pci_warn(dev, "Failed attempting to set the MRRS\n"); mrrs /= 2; } if (mrrs < 128) pci_err(dev, "MRRS was unable to be configured with a safe value. If problems are experienced, try running with pci=pcie_bus_safe\n"); } static int pcie_bus_configure_set(struct pci_dev *dev, void *data) { int mps, orig_mps; if (!pci_is_pcie(dev)) return 0; if (pcie_bus_config == PCIE_BUS_TUNE_OFF || pcie_bus_config == PCIE_BUS_DEFAULT) return 0; mps = 128 << *(u8 *)data; orig_mps = pcie_get_mps(dev); pcie_write_mps(dev, mps); pcie_write_mrrs(dev); pci_info(dev, "Max Payload Size set to %4d/%4d (was %4d), Max Read Rq %4d\n", pcie_get_mps(dev), 128 << dev->pcie_mpss, orig_mps, pcie_get_readrq(dev)); return 0; } /* * pcie_bus_configure_settings() requires that pci_walk_bus work in a top-down, * parents then children fashion. If this changes, then this code will not * work as designed. */ void pcie_bus_configure_settings(struct pci_bus *bus) { u8 smpss = 0; if (!bus->self) return; if (!pci_is_pcie(bus->self)) return; /* * FIXME - Peer to peer DMA is possible, though the endpoint would need * to be aware of the MPS of the destination. To work around this, * simply force the MPS of the entire system to the smallest possible. */ if (pcie_bus_config == PCIE_BUS_PEER2PEER) smpss = 0; if (pcie_bus_config == PCIE_BUS_SAFE) { smpss = bus->self->pcie_mpss; pcie_find_smpss(bus->self, &smpss); pci_walk_bus(bus, pcie_find_smpss, &smpss); } pcie_bus_configure_set(bus->self, &smpss); pci_walk_bus(bus, pcie_bus_configure_set, &smpss); } EXPORT_SYMBOL_GPL(pcie_bus_configure_settings); /* * Called after each bus is probed, but before its children are examined. This * is marked as __weak because multiple architectures define it. */ void __weak pcibios_fixup_bus(struct pci_bus *bus) { /* nothing to do, expected to be removed in the future */ } /** * pci_scan_child_bus_extend() - Scan devices below a bus * @bus: Bus to scan for devices * @available_buses: Total number of buses available (%0 does not try to * extend beyond the minimal) * * Scans devices below @bus including subordinate buses. Returns new * subordinate number including all the found devices. Passing * @available_buses causes the remaining bus space to be distributed * equally between hotplug-capable bridges to allow future extension of the * hierarchy. */ static unsigned int pci_scan_child_bus_extend(struct pci_bus *bus, unsigned int available_buses) { unsigned int used_buses, normal_bridges = 0, hotplug_bridges = 0; unsigned int start = bus->busn_res.start; unsigned int devfn, cmax, max = start; struct pci_dev *dev; dev_dbg(&bus->dev, "scanning bus\n"); /* Go find them, Rover! */ for (devfn = 0; devfn < 256; devfn += 8) pci_scan_slot(bus, devfn); /* Reserve buses for SR-IOV capability */ used_buses = pci_iov_bus_range(bus); max += used_buses; /* * After performing arch-dependent fixup of the bus, look behind * all PCI-to-PCI bridges on this bus. */ if (!bus->is_added) { dev_dbg(&bus->dev, "fixups for bus\n"); pcibios_fixup_bus(bus); bus->is_added = 1; } /* * Calculate how many hotplug bridges and normal bridges there * are on this bus. We will distribute the additional available * buses between hotplug bridges. */ for_each_pci_bridge(dev, bus) { if (dev->is_hotplug_bridge) hotplug_bridges++; else normal_bridges++; } /* * Scan bridges that are already configured. We don't touch them * unless they are misconfigured (which will be done in the second * scan below). */ for_each_pci_bridge(dev, bus) { cmax = max; max = pci_scan_bridge_extend(bus, dev, max, 0, 0); /* * Reserve one bus for each bridge now to avoid extending * hotplug bridges too much during the second scan below. */ used_buses++; if (max - cmax > 1) used_buses += max - cmax - 1; } /* Scan bridges that need to be reconfigured */ for_each_pci_bridge(dev, bus) { unsigned int buses = 0; if (!hotplug_bridges && normal_bridges == 1) { /* * There is only one bridge on the bus (upstream * port) so it gets all available buses which it * can then distribute to the possible hotplug * bridges below. */ buses = available_buses; } else if (dev->is_hotplug_bridge) { /* * Distribute the extra buses between hotplug * bridges if any. */ buses = available_buses / hotplug_bridges; buses = min(buses, available_buses - used_buses + 1); } cmax = max; max = pci_scan_bridge_extend(bus, dev, cmax, buses, 1); /* One bus is already accounted so don't add it again */ if (max - cmax > 1) used_buses += max - cmax - 1; } /* * Make sure a hotplug bridge has at least the minimum requested * number of buses but allow it to grow up to the maximum available * bus number if there is room. */ if (bus->self && bus->self->is_hotplug_bridge) { used_buses = max_t(unsigned int, available_buses, pci_hotplug_bus_size - 1); if (max - start < used_buses) { max = start + used_buses; /* Do not allocate more buses than we have room left */ if (max > bus->busn_res.end) max = bus->busn_res.end; dev_dbg(&bus->dev, "%pR extended by %#02x\n", &bus->busn_res, max - start); } } /* * We've scanned the bus and so we know all about what's on * the other side of any bridges that may be on this bus plus * any devices. * * Return how far we've got finding sub-buses. */ dev_dbg(&bus->dev, "bus scan returning with max=%02x\n", max); return max; } /** * pci_scan_child_bus() - Scan devices below a bus * @bus: Bus to scan for devices * * Scans devices below @bus including subordinate buses. Returns new * subordinate number including all the found devices. */ unsigned int pci_scan_child_bus(struct pci_bus *bus) { return pci_scan_child_bus_extend(bus, 0); } EXPORT_SYMBOL_GPL(pci_scan_child_bus); /** * pcibios_root_bridge_prepare - Platform-specific host bridge setup * @bridge: Host bridge to set up * * Default empty implementation. Replace with an architecture-specific setup * routine, if necessary. */ int __weak pcibios_root_bridge_prepare(struct pci_host_bridge *bridge) { return 0; } void __weak pcibios_add_bus(struct pci_bus *bus) { } void __weak pcibios_remove_bus(struct pci_bus *bus) { } struct pci_bus *pci_create_root_bus(struct device *parent, int bus, struct pci_ops *ops, void *sysdata, struct list_head *resources) { int error; struct pci_host_bridge *bridge; bridge = pci_alloc_host_bridge(0); if (!bridge) return NULL; bridge->dev.parent = parent; list_splice_init(resources, &bridge->windows); bridge->sysdata = sysdata; bridge->busnr = bus; bridge->ops = ops; error = pci_register_host_bridge(bridge); if (error < 0) goto err_out; return bridge->bus; err_out: put_device(&bridge->dev); return NULL; } EXPORT_SYMBOL_GPL(pci_create_root_bus); int pci_host_probe(struct pci_host_bridge *bridge) { struct pci_bus *bus, *child; int ret; ret = pci_scan_root_bus_bridge(bridge); if (ret < 0) { dev_err(bridge->dev.parent, "Scanning root bridge failed"); return ret; } bus = bridge->bus; /* * We insert PCI resources into the iomem_resource and * ioport_resource trees in either pci_bus_claim_resources() * or pci_bus_assign_resources(). */ if (pci_has_flag(PCI_PROBE_ONLY)) { pci_bus_claim_resources(bus); } else { pci_bus_size_bridges(bus); pci_bus_assign_resources(bus); list_for_each_entry(child, &bus->children, node) pcie_bus_configure_settings(child); } pci_bus_add_devices(bus); return 0; } EXPORT_SYMBOL_GPL(pci_host_probe); int pci_bus_insert_busn_res(struct pci_bus *b, int bus, int bus_max) { struct resource *res = &b->busn_res; struct resource *parent_res, *conflict; res->start = bus; res->end = bus_max; res->flags = IORESOURCE_BUS; if (!pci_is_root_bus(b)) parent_res = &b->parent->busn_res; else { parent_res = get_pci_domain_busn_res(pci_domain_nr(b)); res->flags |= IORESOURCE_PCI_FIXED; } conflict = request_resource_conflict(parent_res, res); if (conflict) dev_info(&b->dev, "busn_res: can not insert %pR under %s%pR (conflicts with %s %pR)\n", res, pci_is_root_bus(b) ? "domain " : "", parent_res, conflict->name, conflict); return conflict == NULL; } int pci_bus_update_busn_res_end(struct pci_bus *b, int bus_max) { struct resource *res = &b->busn_res; struct resource old_res = *res; resource_size_t size; int ret; if (res->start > bus_max) return -EINVAL; size = bus_max - res->start + 1; ret = adjust_resource(res, res->start, size); dev_info(&b->dev, "busn_res: %pR end %s updated to %02x\n", &old_res, ret ? "can not be" : "is", bus_max); if (!ret && !res->parent) pci_bus_insert_busn_res(b, res->start, res->end); return ret; } void pci_bus_release_busn_res(struct pci_bus *b) { struct resource *res = &b->busn_res; int ret; if (!res->flags || !res->parent) return; ret = release_resource(res); dev_info(&b->dev, "busn_res: %pR %s released\n", res, ret ? "can not be" : "is"); } int pci_scan_root_bus_bridge(struct pci_host_bridge *bridge) { struct resource_entry *window; bool found = false; struct pci_bus *b; int max, bus, ret; if (!bridge) return -EINVAL; resource_list_for_each_entry(window, &bridge->windows) if (window->res->flags & IORESOURCE_BUS) { bridge->busnr = window->res->start; found = true; break; } ret = pci_register_host_bridge(bridge); if (ret < 0) return ret; b = bridge->bus; bus = bridge->busnr; if (!found) { dev_info(&b->dev, "No busn resource found for root bus, will use [bus %02x-ff]\n", bus); pci_bus_insert_busn_res(b, bus, 255); } max = pci_scan_child_bus(b); if (!found) pci_bus_update_busn_res_end(b, max); return 0; } EXPORT_SYMBOL(pci_scan_root_bus_bridge); struct pci_bus *pci_scan_root_bus(struct device *parent, int bus, struct pci_ops *ops, void *sysdata, struct list_head *resources) { struct resource_entry *window; bool found = false; struct pci_bus *b; int max; resource_list_for_each_entry(window, resources) if (window->res->flags & IORESOURCE_BUS) { found = true; break; } b = pci_create_root_bus(parent, bus, ops, sysdata, resources); if (!b) return NULL; if (!found) { dev_info(&b->dev, "No busn resource found for root bus, will use [bus %02x-ff]\n", bus); pci_bus_insert_busn_res(b, bus, 255); } max = pci_scan_child_bus(b); if (!found) pci_bus_update_busn_res_end(b, max); return b; } EXPORT_SYMBOL(pci_scan_root_bus); struct pci_bus *pci_scan_bus(int bus, struct pci_ops *ops, void *sysdata) { LIST_HEAD(resources); struct pci_bus *b; pci_add_resource(&resources, &ioport_resource); pci_add_resource(&resources, &iomem_resource); pci_add_resource(&resources, &busn_resource); b = pci_create_root_bus(NULL, bus, ops, sysdata, &resources); if (b) { pci_scan_child_bus(b); } else { pci_free_resource_list(&resources); } return b; } EXPORT_SYMBOL(pci_scan_bus); /** * pci_rescan_bus_bridge_resize - Scan a PCI bus for devices * @bridge: PCI bridge for the bus to scan * * Scan a PCI bus and child buses for new devices, add them, * and enable them, resizing bridge mmio/io resource if necessary * and possible. The caller must ensure the child devices are already * removed for resizing to occur. * * Returns the max number of subordinate bus discovered. */ unsigned int pci_rescan_bus_bridge_resize(struct pci_dev *bridge) { unsigned int max; struct pci_bus *bus = bridge->subordinate; max = pci_scan_child_bus(bus); pci_assign_unassigned_bridge_resources(bridge); pci_bus_add_devices(bus); return max; } /** * pci_rescan_bus - Scan a PCI bus for devices * @bus: PCI bus to scan * * Scan a PCI bus and child buses for new devices, add them, * and enable them. * * Returns the max number of subordinate bus discovered. */ unsigned int pci_rescan_bus(struct pci_bus *bus) { unsigned int max; max = pci_scan_child_bus(bus); pci_assign_unassigned_bus_resources(bus); pci_bus_add_devices(bus); return max; } EXPORT_SYMBOL_GPL(pci_rescan_bus); /* * pci_rescan_bus(), pci_rescan_bus_bridge_resize() and PCI device removal * routines should always be executed under this mutex. */ static DEFINE_MUTEX(pci_rescan_remove_lock); void pci_lock_rescan_remove(void) { mutex_lock(&pci_rescan_remove_lock); } EXPORT_SYMBOL_GPL(pci_lock_rescan_remove); void pci_unlock_rescan_remove(void) { mutex_unlock(&pci_rescan_remove_lock); } EXPORT_SYMBOL_GPL(pci_unlock_rescan_remove); static int __init pci_sort_bf_cmp(const struct device *d_a, const struct device *d_b) { const struct pci_dev *a = to_pci_dev(d_a); const struct pci_dev *b = to_pci_dev(d_b); if (pci_domain_nr(a->bus) < pci_domain_nr(b->bus)) return -1; else if (pci_domain_nr(a->bus) > pci_domain_nr(b->bus)) return 1; if (a->bus->number < b->bus->number) return -1; else if (a->bus->number > b->bus->number) return 1; if (a->devfn < b->devfn) return -1; else if (a->devfn > b->devfn) return 1; return 0; } void __init pci_sort_breadthfirst(void) { bus_sort_breadthfirst(&pci_bus_type, &pci_sort_bf_cmp); } int pci_hp_add_bridge(struct pci_dev *dev) { struct pci_bus *parent = dev->bus; int busnr, start = parent->busn_res.start; unsigned int available_buses = 0; int end = parent->busn_res.end; for (busnr = start; busnr <= end; busnr++) { if (!pci_find_bus(pci_domain_nr(parent), busnr)) break; } if (busnr-- > end) { pci_err(dev, "No bus number available for hot-added bridge\n"); return -1; } /* Scan bridges that are already configured */ busnr = pci_scan_bridge(parent, dev, busnr, 0); /* * Distribute the available bus numbers between hotplug-capable * bridges to make extending the chain later possible. */ available_buses = end - busnr; /* Scan bridges that need to be reconfigured */ pci_scan_bridge_extend(parent, dev, busnr, available_buses, 1); if (!dev->subordinate) return -1; return 0; } EXPORT_SYMBOL_GPL(pci_hp_add_bridge);