/* SPDX-License-Identifier: GPL-2.0-only */ /* * Originally based on the Linux kernel (drivers/pci/pci.c). * PCI Bus Services, see include/linux/pci.h for further explanation. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include u8 pci_moving_config8(struct device *dev, unsigned int reg) { u8 value, ones, zeroes; value = pci_read_config8(dev, reg); pci_write_config8(dev, reg, 0xff); ones = pci_read_config8(dev, reg); pci_write_config8(dev, reg, 0x00); zeroes = pci_read_config8(dev, reg); pci_write_config8(dev, reg, value); return ones ^ zeroes; } u16 pci_moving_config16(struct device *dev, unsigned int reg) { u16 value, ones, zeroes; value = pci_read_config16(dev, reg); pci_write_config16(dev, reg, 0xffff); ones = pci_read_config16(dev, reg); pci_write_config16(dev, reg, 0x0000); zeroes = pci_read_config16(dev, reg); pci_write_config16(dev, reg, value); return ones ^ zeroes; } u32 pci_moving_config32(struct device *dev, unsigned int reg) { u32 value, ones, zeroes; value = pci_read_config32(dev, reg); pci_write_config32(dev, reg, 0xffffffff); ones = pci_read_config32(dev, reg); pci_write_config32(dev, reg, 0x00000000); zeroes = pci_read_config32(dev, reg); pci_write_config32(dev, reg, value); return ones ^ zeroes; } /** * Given a device and register, read the size of the BAR for that register. * * @param dev Pointer to the device structure. * @param index Address of the PCI configuration register. * @return TODO */ struct resource *pci_get_resource(struct device *dev, unsigned long index) { struct resource *resource; unsigned long value, attr; resource_t moving, limit; /* Initialize the resources to nothing. */ resource = new_resource(dev, index); /* Get the initial value. */ value = pci_read_config32(dev, index); /* See which bits move. */ moving = pci_moving_config32(dev, index); /* Initialize attr to the bits that do not move. */ attr = value & ~moving; /* If it is a 64bit resource look at the high half as well. */ if (((attr & PCI_BASE_ADDRESS_SPACE_IO) == 0) && ((attr & PCI_BASE_ADDRESS_MEM_LIMIT_MASK) == PCI_BASE_ADDRESS_MEM_LIMIT_64)) { /* Find the high bits that move. */ moving |= ((resource_t)pci_moving_config32(dev, index + 4)) << 32; } /* Find the resource constraints. * Start by finding the bits that move. From there: * - Size is the least significant bit of the bits that move. * - Limit is all of the bits that move plus all of the lower bits. * See PCI Spec 6.2.5.1. */ limit = 0; if (moving) { resource->size = 1; resource->align = resource->gran = 0; while (!(moving & resource->size)) { resource->size <<= 1; resource->align += 1; resource->gran += 1; } resource->limit = limit = moving | (resource->size - 1); if (pci_base_address_is_memory_space(attr)) { /* Page-align to allow individual mapping of devices. */ if (resource->align < 12) resource->align = 12; } } /* * Some broken hardware has read-only registers that do not * really size correctly. * * Example: the Acer M7229 has BARs 1-4 normally read-only, * so BAR1 at offset 0x10 reads 0x1f1. If you size that register * by writing 0xffffffff to it, it will read back as 0x1f1 -- which * is a violation of the spec. * * We catch this case and ignore it by observing which bits move. * * This also catches the common case of unimplemented registers * that always read back as 0. */ if (moving == 0) { if (value != 0) { printk(BIOS_DEBUG, "%s register %02lx(%08lx), read-only ignoring it\n", dev_path(dev), index, value); } resource->flags = 0; } else if (attr & PCI_BASE_ADDRESS_SPACE_IO) { /* An I/O mapped base address. */ resource->flags |= IORESOURCE_IO; /* I don't want to deal with 32bit I/O resources. */ resource->limit = 0xffff; } else { /* A Memory mapped base address. */ attr &= PCI_BASE_ADDRESS_MEM_ATTR_MASK; resource->flags |= IORESOURCE_MEM; if (attr & PCI_BASE_ADDRESS_MEM_PREFETCH) { resource->flags |= IORESOURCE_PREFETCH; if (CONFIG(PCIEXP_HOTPLUG_PREFETCH_MEM_ABOVE_4G) && dev_path_hotplug(dev)) resource->flags |= IORESOURCE_ABOVE_4G; } attr &= PCI_BASE_ADDRESS_MEM_LIMIT_MASK; if (attr == PCI_BASE_ADDRESS_MEM_LIMIT_32) { /* 32bit limit. */ resource->limit = 0xffffffffUL; } else if (attr == PCI_BASE_ADDRESS_MEM_LIMIT_1M) { /* 1MB limit. */ resource->limit = 0x000fffffUL; } else if (attr == PCI_BASE_ADDRESS_MEM_LIMIT_64) { /* 64bit limit. */ resource->limit = 0xffffffffffffffffULL; resource->flags |= IORESOURCE_PCI64; } else { /* Invalid value. */ printk(BIOS_ERR, "Broken BAR with value %lx\n", attr); printk(BIOS_ERR, " on dev %s at index %02lx\n", dev_path(dev), index); resource->flags = 0; } } /* Don't let the limit exceed which bits can move. */ if (resource->limit > limit) resource->limit = limit; return resource; } /** * Given a device and an index, read the size of the BAR for that register. * * @param dev Pointer to the device structure. * @param index Address of the PCI configuration register. */ static void pci_get_rom_resource(struct device *dev, unsigned long index) { struct resource *resource; unsigned long value; resource_t moving; /* Initialize the resources to nothing. */ resource = new_resource(dev, index); /* Get the initial value. */ value = pci_read_config32(dev, index); /* See which bits move. */ moving = pci_moving_config32(dev, index); /* Clear the Enable bit. */ moving = moving & ~PCI_ROM_ADDRESS_ENABLE; /* Find the resource constraints. * Start by finding the bits that move. From there: * - Size is the least significant bit of the bits that move. * - Limit is all of the bits that move plus all of the lower bits. * See PCI Spec 6.2.5.1. */ if (moving) { resource->size = 1; resource->align = resource->gran = 0; while (!(moving & resource->size)) { resource->size <<= 1; resource->align += 1; resource->gran += 1; } resource->limit = moving | (resource->size - 1); resource->flags |= IORESOURCE_MEM | IORESOURCE_READONLY; } else { if (value != 0) { printk(BIOS_DEBUG, "%s register %02lx(%08lx), read-only ignoring it\n", dev_path(dev), index, value); } resource->flags = 0; } compact_resources(dev); } /** * Given a device, read the size of the MSI-X table. * * @param dev Pointer to the device structure. * @return MSI-X table size or 0 if not MSI-X capable device */ size_t pci_msix_table_size(struct device *dev) { const size_t pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); if (!pos) return 0; const u16 control = pci_read_config16(dev, pos + PCI_MSIX_FLAGS); return (control & PCI_MSIX_FLAGS_QSIZE) + 1; } /** * Given a device, return the table offset and bar the MSI-X tables resides in. * * @param dev Pointer to the device structure. * @param offset Returned value gives the offset in bytes inside the PCI BAR. * @param idx The returned value is the index of the PCI_BASE_ADDRESS register * the MSI-X table is located in. * @return Zero on success */ int pci_msix_table_bar(struct device *dev, u32 *offset, u8 *idx) { const size_t pos = pci_find_capability(dev, PCI_CAP_ID_MSIX); if (!pos || !offset || !idx) return 1; *offset = pci_read_config32(dev, pos + PCI_MSIX_TABLE); *idx = (u8)(*offset & PCI_MSIX_PBA_BIR); *offset &= PCI_MSIX_PBA_OFFSET; return 0; } /** * Given a device, return a msix_entry pointer or NULL if no table was found. * * @param dev Pointer to the device structure. * * @return NULL on error */ struct msix_entry *pci_msix_get_table(struct device *dev) { struct resource *res; u32 offset; u8 idx; if (pci_msix_table_bar(dev, &offset, &idx)) return NULL; if (idx > 5) return NULL; res = probe_resource(dev, idx * 4 + PCI_BASE_ADDRESS_0); if (!res || !res->base || offset >= res->size) return NULL; if ((res->flags & IORESOURCE_PCI64) && (uintptr_t)res->base != res->base) return NULL; return (struct msix_entry *)((uintptr_t)res->base + offset); } static unsigned int get_rebar_offset(const struct device *dev, unsigned long index) { uint32_t offset = pciexp_find_extended_cap(dev, PCIE_EXT_CAP_RESIZABLE_BAR, 0); if (!offset) return 0; /* Convert PCI_BASE_ADDRESS_0, ..._1, ..._2 into 0, 1, 2... */ const unsigned int find_bar_idx = (index - PCI_BASE_ADDRESS_0) / sizeof(uint32_t); /* Although all of the Resizable BAR Control Registers contain an "NBARs" field, it is only valid in the Control Register for BAR 0 */ const uint32_t rebar_ctrl0 = pci_read_config32(dev, offset + PCI_REBAR_CTRL_OFFSET); const unsigned int nbars = (rebar_ctrl0 & PCI_REBAR_CTRL_NBARS_MASK) >> PCI_REBAR_CTRL_NBARS_SHIFT; for (unsigned int i = 0; i < nbars; i++, offset += sizeof(uint64_t)) { const uint32_t rebar_ctrl = pci_read_config32( dev, offset + PCI_REBAR_CTRL_OFFSET); const uint32_t bar_idx = rebar_ctrl & PCI_REBAR_CTRL_IDX_MASK; if (bar_idx == find_bar_idx) return offset; } return 0; } /* Bit 20 = 1 MiB, bit 21 = 2 MiB, bit 22 = 4 MiB, ... bit 63 = 8 EiB */ static uint64_t get_rebar_sizes_mask(const struct device *dev, unsigned long index) { uint64_t size_mask = 0ULL; const uint32_t offset = get_rebar_offset(dev, index); if (!offset) return 0; /* Get 1 MB - 128 TB support from CAP register */ const uint32_t cap = pci_read_config32(dev, offset + PCI_REBAR_CAP_OFFSET); /* Shift the bits from 4-31 to 0-27 (i.e., down by 4 bits) */ size_mask |= ((cap & PCI_REBAR_CAP_SIZE_MASK) >> 4); /* Get 256 TB - 8 EB support from CTRL register and store it in bits 28-43 */ const uint64_t ctrl = pci_read_config32(dev, offset + PCI_REBAR_CTRL_OFFSET); /* Shift ctrl mask from bit 16 to bit 28, so that the two masks (fom cap and ctrl) form a contiguous bitmask when concatenated (i.e., up by 12 bits). */ size_mask |= ((ctrl & PCI_REBAR_CTRL_SIZE_MASK) << 12); /* Now that the mask occupies bits 0-43, shift it up to 20-63, so they represent the actual powers of 2. */ return size_mask << 20; } static void pci_store_rebar_size(const struct device *dev, const struct resource *resource) { const unsigned int num_bits = __fls64(resource->size); const uint32_t offset = get_rebar_offset(dev, resource->index); if (!offset) return; pci_update_config32(dev, offset + PCI_REBAR_CTRL_OFFSET, ~PCI_REBAR_CTRL_SIZE_MASK, num_bits << PCI_REBAR_CTRL_SIZE_SHIFT); } static void configure_adjustable_base(const struct device *dev, unsigned long index, struct resource *res) { /* * Excerpt from an implementation note from the PCIe spec: * * System software uses this capability in place of the above mentioned * method of determining the resource size[0], and prior to assigning * the base address to the BAR. Potential usable resource sizes are * reported by the Function via its Resizable BAR Capability and Control * registers. It is intended that the software allocate the largest of * the reported sizes that it can, since allocating less address space * than the largest reported size can result in lower * performance. Software then writes the size to the Resizable BAR * Control register for the appropriate BAR for the Function. Following * this, the base address is written to the BAR. * * [0] Referring to using the moving bits in the BAR to determine the * requested size of the MMIO region */ const uint64_t size_mask = get_rebar_sizes_mask(dev, index); if (!size_mask) return; int max_requested_bits = __fls64(size_mask); if (max_requested_bits > CONFIG_PCIEXP_DEFAULT_MAX_RESIZABLE_BAR_BITS) { printk(BIOS_WARNING, "Device %s requests a BAR with" " %u bits of address space, which coreboot is not" " configured to hand out, truncating to %u bits\n", dev_path(dev), max_requested_bits, CONFIG_PCIEXP_DEFAULT_MAX_RESIZABLE_BAR_BITS); max_requested_bits = CONFIG_PCIEXP_DEFAULT_MAX_RESIZABLE_BAR_BITS; } if (!(res->flags & IORESOURCE_PCI64) && max_requested_bits > 32) { printk(BIOS_ERR, "Resizable BAR requested" " above 32 bits, but PCI function reported a" " 32-bit BAR."); return; } /* Configure the resource parameters for the adjustable BAR */ res->size = 1ULL << max_requested_bits; res->align = max_requested_bits; res->gran = max_requested_bits; res->limit = (res->flags & IORESOURCE_PCI64) ? UINT64_MAX : UINT32_MAX; res->flags |= (res->flags & IORESOURCE_PCI64) ? IORESOURCE_PCIE_RESIZABLE_BAR | IORESOURCE_ABOVE_4G : IORESOURCE_PCIE_RESIZABLE_BAR; printk(BIOS_INFO, "%s: Adjusting resource index %lu: base: %llx size: %llx " "align: %d gran: %d limit: %llx\n", dev_path(dev), res->index, res->base, res->size, res->align, res->gran, res->limit); } /** * Read the base address registers for a given device. * * @param dev Pointer to the dev structure. * @param howmany How many registers to read (6 for device, 2 for bridge). */ static void pci_read_bases(struct device *dev, unsigned int howmany) { unsigned long index; for (index = PCI_BASE_ADDRESS_0; (index < PCI_BASE_ADDRESS_0 + (howmany << 2));) { struct resource *resource; resource = pci_get_resource(dev, index); const bool is_pcie = pci_find_capability(dev, PCI_CAP_ID_PCIE) != 0; if (CONFIG(PCIEXP_SUPPORT_RESIZABLE_BARS) && is_pcie) configure_adjustable_base(dev, index, resource); index += (resource->flags & IORESOURCE_PCI64) ? 8 : 4; } compact_resources(dev); } static void pci_record_bridge_resource(struct device *dev, resource_t moving, unsigned int index, unsigned long type) { struct resource *resource; unsigned long gran; resource_t step; resource = NULL; if (!moving) return; /* Initialize the constraints on the current bus. */ resource = new_resource(dev, index); resource->size = 0; gran = 0; step = 1; while ((moving & step) == 0) { gran += 1; step <<= 1; } resource->gran = gran; resource->align = gran; resource->limit = moving | (step - 1); resource->flags = type | IORESOURCE_PCI_BRIDGE | IORESOURCE_BRIDGE; } static void pci_bridge_read_bases(struct device *dev) { resource_t moving_base, moving_limit, moving; /* See if the bridge I/O resources are implemented. */ moving_base = ((u32)pci_moving_config8(dev, PCI_IO_BASE)) << 8; moving_base |= ((u32)pci_moving_config16(dev, PCI_IO_BASE_UPPER16)) << 16; moving_limit = ((u32)pci_moving_config8(dev, PCI_IO_LIMIT)) << 8; moving_limit |= ((u32)pci_moving_config16(dev, PCI_IO_LIMIT_UPPER16)) << 16; moving = moving_base & moving_limit; /* Initialize the I/O space constraints on the current bus. */ pci_record_bridge_resource(dev, moving, PCI_IO_BASE, IORESOURCE_IO); /* See if the bridge prefmem resources are implemented. */ moving_base = ((resource_t)pci_moving_config16(dev, PCI_PREF_MEMORY_BASE)) << 16; moving_base |= ((resource_t)pci_moving_config32(dev, PCI_PREF_BASE_UPPER32)) << 32; moving_limit = ((resource_t)pci_moving_config16(dev, PCI_PREF_MEMORY_LIMIT)) << 16; moving_limit |= ((resource_t)pci_moving_config32(dev, PCI_PREF_LIMIT_UPPER32)) << 32; moving = moving_base & moving_limit; /* Initialize the prefetchable memory constraints on the current bus. */ pci_record_bridge_resource(dev, moving, PCI_PREF_MEMORY_BASE, IORESOURCE_MEM | IORESOURCE_PREFETCH); /* See if the bridge mem resources are implemented. */ moving_base = ((u32)pci_moving_config16(dev, PCI_MEMORY_BASE)) << 16; moving_limit = ((u32)pci_moving_config16(dev, PCI_MEMORY_LIMIT)) << 16; moving = moving_base & moving_limit; /* Initialize the memory resources on the current bus. */ pci_record_bridge_resource(dev, moving, PCI_MEMORY_BASE, IORESOURCE_MEM); compact_resources(dev); } void pci_dev_read_resources(struct device *dev) { pci_read_bases(dev, 6); pci_get_rom_resource(dev, PCI_ROM_ADDRESS); } void pci_bus_read_resources(struct device *dev) { pci_bridge_read_bases(dev); pci_read_bases(dev, 2); pci_get_rom_resource(dev, PCI_ROM_ADDRESS1); } void pci_domain_read_resources(struct device *dev) { struct resource *res; /* Initialize the system-wide I/O space constraints. */ res = new_resource(dev, IOINDEX_SUBTRACTIVE(0, 0)); res->limit = 0xffffUL; res->flags = IORESOURCE_IO | IORESOURCE_SUBTRACTIVE | IORESOURCE_ASSIGNED; /* * Initialize 32-bit memory resource constraints. * * There are often undeclared chipset resources in lower memory * and memory right below the 4G barrier. Hence, only allow * one big range from cbmem_top to the configured limit. */ res = new_resource(dev, IOINDEX_SUBTRACTIVE(1, 0)); res->base = (uintptr_t)cbmem_top(); res->limit = CONFIG_DOMAIN_RESOURCE_32BIT_LIMIT - 1; res->flags = IORESOURCE_MEM | IORESOURCE_SUBTRACTIVE | IORESOURCE_ASSIGNED; /* Initialize 64-bit memory resource constraints above 4G. */ res = new_resource(dev, IOINDEX_SUBTRACTIVE(2, 0)); res->base = 4ULL * GiB; res->limit = (1ULL << soc_phys_address_size()) - 1; res->flags = IORESOURCE_MEM | IORESOURCE_SUBTRACTIVE | IORESOURCE_ASSIGNED; } void pci_domain_set_resources(struct device *dev) { assign_resources(dev->downstream); } static void pci_store_resource(const struct device *const dev, const struct resource *const resource) { unsigned long base_lo, base_hi; base_lo = resource->base & 0xffffffff; base_hi = (resource->base >> 32) & 0xffffffff; /* * Some chipsets allow us to set/clear the I/O bit * (e.g. VIA 82C686A). So set it to be safe. */ if (resource->flags & IORESOURCE_IO) base_lo |= PCI_BASE_ADDRESS_SPACE_IO; pci_write_config32(dev, resource->index, base_lo); if (resource->flags & IORESOURCE_PCI64) pci_write_config32(dev, resource->index + 4, base_hi); } static void pci_store_bridge_resource(const struct device *const dev, struct resource *const resource) { resource_t base, end; /* * PCI bridges have no enable bit. They are disabled if the base of * the range is greater than the limit. If the size is zero, disable * by setting the base = limit and end = limit - 2^gran. */ if (resource->size == 0) { base = resource->limit; end = resource->limit - (1 << resource->gran); resource->base = base; } else { base = resource->base; end = resource_end(resource); } if (resource->index == PCI_IO_BASE) { /* Set the I/O ranges. */ pci_write_config8(dev, PCI_IO_BASE, base >> 8); pci_write_config16(dev, PCI_IO_BASE_UPPER16, base >> 16); pci_write_config8(dev, PCI_IO_LIMIT, end >> 8); pci_write_config16(dev, PCI_IO_LIMIT_UPPER16, end >> 16); } else if (resource->index == PCI_MEMORY_BASE) { /* Set the memory range. */ pci_write_config16(dev, PCI_MEMORY_BASE, base >> 16); pci_write_config16(dev, PCI_MEMORY_LIMIT, end >> 16); } else if (resource->index == PCI_PREF_MEMORY_BASE) { /* Set the prefetchable memory range. */ pci_write_config16(dev, PCI_PREF_MEMORY_BASE, base >> 16); pci_write_config32(dev, PCI_PREF_BASE_UPPER32, base >> 32); pci_write_config16(dev, PCI_PREF_MEMORY_LIMIT, end >> 16); pci_write_config32(dev, PCI_PREF_LIMIT_UPPER32, end >> 32); } else { /* Don't let me think I stored the resource. */ resource->flags &= ~IORESOURCE_STORED; printk(BIOS_ERR, "invalid resource->index %lx\n", resource->index); } } static void pci_set_resource(struct device *dev, struct resource *resource) { /* Make certain the resource has actually been assigned a value. */ if (!(resource->flags & IORESOURCE_ASSIGNED)) { if (resource->flags & IORESOURCE_BRIDGE) { /* If a bridge resource has no value assigned, we can treat it like an empty resource. */ resource->size = 0; } else { printk(BIOS_ERR, "%s %02lx %s size: 0x%010llx not assigned\n", dev_path(dev), resource->index, resource_type(resource), resource->size); return; } } /* If this resource is fixed don't worry about it. */ if (resource->flags & IORESOURCE_FIXED) return; /* If I have already stored this resource don't worry about it. */ if (resource->flags & IORESOURCE_STORED) return; /* If the resource is subtractive don't worry about it. */ if (resource->flags & IORESOURCE_SUBTRACTIVE) return; /* Only handle PCI memory and I/O resources for now. */ if (!(resource->flags & (IORESOURCE_MEM | IORESOURCE_IO))) return; /* Enable the resources in the command register. */ if (resource->size) { if (resource->flags & IORESOURCE_MEM) dev->command |= PCI_COMMAND_MEMORY; if (resource->flags & IORESOURCE_IO) dev->command |= PCI_COMMAND_IO; if (resource->flags & IORESOURCE_PCI_BRIDGE && CONFIG(PCI_SET_BUS_MASTER_PCI_BRIDGES)) dev->command |= PCI_COMMAND_MASTER; } /* Now store the resource. */ resource->flags |= IORESOURCE_STORED; if (!(resource->flags & IORESOURCE_PCI_BRIDGE)) { if (CONFIG(PCIEXP_SUPPORT_RESIZABLE_BARS) && (resource->flags & IORESOURCE_PCIE_RESIZABLE_BAR)) pci_store_rebar_size(dev, resource); pci_store_resource(dev, resource); } else { pci_store_bridge_resource(dev, resource); } report_resource_stored(dev, resource, ""); } void pci_dev_set_resources(struct device *dev) { struct resource *res; u8 line; for (res = dev->resource_list; res; res = res->next) pci_set_resource(dev, res); if (dev->downstream && dev->downstream->children) assign_resources(dev->downstream); /* Set a default latency timer. */ pci_write_config8(dev, PCI_LATENCY_TIMER, 0x40); /* Set a default secondary latency timer. */ if ((dev->hdr_type & 0x7f) == PCI_HEADER_TYPE_BRIDGE) pci_write_config8(dev, PCI_SEC_LATENCY_TIMER, 0x40); /* Zero the IRQ settings. */ line = pci_read_config8(dev, PCI_INTERRUPT_PIN); if (line) pci_write_config8(dev, PCI_INTERRUPT_LINE, 0); /* Set the cache line size, so far 64 bytes is good for everyone. */ pci_write_config8(dev, PCI_CACHE_LINE_SIZE, 64 >> 2); } void pci_dev_enable_resources(struct device *dev) { const struct pci_operations *ops = NULL; u16 command; /* Set the subsystem vendor and device ID for mainboard devices. */ if (dev->ops) ops = dev->ops->ops_pci; if (dev->on_mainboard && ops && ops->set_subsystem) { if (CONFIG_SUBSYSTEM_VENDOR_ID) dev->subsystem_vendor = CONFIG_SUBSYSTEM_VENDOR_ID; else if (!dev->subsystem_vendor) dev->subsystem_vendor = pci_read_config16(dev, PCI_VENDOR_ID); if (CONFIG_SUBSYSTEM_DEVICE_ID) dev->subsystem_device = CONFIG_SUBSYSTEM_DEVICE_ID; else if (!dev->subsystem_device) dev->subsystem_device = pci_read_config16(dev, PCI_DEVICE_ID); printk(BIOS_DEBUG, "%s subsystem <- %04x/%04x\n", dev_path(dev), dev->subsystem_vendor, dev->subsystem_device); ops->set_subsystem(dev, dev->subsystem_vendor, dev->subsystem_device); } command = pci_read_config16(dev, PCI_COMMAND); command |= dev->command; /* v3 has * command |= (PCI_COMMAND_PARITY + PCI_COMMAND_SERR); // Error check. */ printk(BIOS_DEBUG, "%s cmd <- %02x\n", dev_path(dev), command); pci_write_config16(dev, PCI_COMMAND, command); } void pci_bus_enable_resources(struct device *dev) { u16 ctrl; /* * Enable I/O in command register if there is VGA card * connected with (even it does not claim I/O resource). */ if (dev->downstream->bridge_ctrl & PCI_BRIDGE_CTL_VGA) dev->command |= PCI_COMMAND_IO; ctrl = pci_read_config16(dev, PCI_BRIDGE_CONTROL); ctrl |= dev->downstream->bridge_ctrl; ctrl |= (PCI_BRIDGE_CTL_PARITY | PCI_BRIDGE_CTL_SERR); /* Error check. */ printk(BIOS_DEBUG, "%s bridge ctrl <- %04x\n", dev_path(dev), ctrl); pci_write_config16(dev, PCI_BRIDGE_CONTROL, ctrl); pci_dev_enable_resources(dev); } void pci_bus_reset(struct bus *bus) { u16 ctl; ctl = pci_read_config16(bus->dev, PCI_BRIDGE_CONTROL); ctl |= PCI_BRIDGE_CTL_BUS_RESET; pci_write_config16(bus->dev, PCI_BRIDGE_CONTROL, ctl); mdelay(10); ctl &= ~PCI_BRIDGE_CTL_BUS_RESET; pci_write_config16(bus->dev, PCI_BRIDGE_CONTROL, ctl); delay(1); } void pci_dev_set_subsystem(struct device *dev, unsigned int vendor, unsigned int device) { uint8_t offset; /* Header type */ switch (dev->hdr_type & 0x7f) { case PCI_HEADER_TYPE_NORMAL: offset = PCI_SUBSYSTEM_VENDOR_ID; break; case PCI_HEADER_TYPE_BRIDGE: offset = pci_find_capability(dev, PCI_CAP_ID_SSVID); if (!offset) return; offset += 4; /* Vendor ID at offset 4 */ break; case PCI_HEADER_TYPE_CARDBUS: offset = PCI_CB_SUBSYSTEM_VENDOR_ID; break; default: return; } if (!vendor || !device) { pci_write_config32(dev, offset, pci_read_config32(dev, PCI_VENDOR_ID)); } else { pci_write_config32(dev, offset, ((device & 0xffff) << 16) | (vendor & 0xffff)); } } static int should_run_oprom(struct device *dev, struct rom_header *rom) { static int should_run = -1; if (dev->upstream->segment_group) { printk(BIOS_ERR, "Only option ROMs of devices in first PCI segment group can " "be run.\n"); return 0; } if (CONFIG(VENDORCODE_ELTAN_VBOOT)) if (rom != NULL) if (!verified_boot_should_run_oprom(rom)) return 0; if (should_run >= 0) return should_run; if (CONFIG(ALWAYS_RUN_OPROM)) { should_run = 1; return should_run; } /* Don't run VGA option ROMs, unless we have to print * something on the screen before the kernel is loaded. */ should_run = display_init_required(); if (!should_run) printk(BIOS_DEBUG, "Not running VGA Option ROM\n"); return should_run; } static int should_load_oprom(struct device *dev) { /* If S3_VGA_ROM_RUN is disabled, skip running VGA option * ROMs when coming out of an S3 resume. */ if (!CONFIG(S3_VGA_ROM_RUN) && acpi_is_wakeup_s3() && ((dev->class >> 8) == PCI_CLASS_DISPLAY_VGA)) return 0; if (CONFIG(ALWAYS_LOAD_OPROM)) return 1; if (should_run_oprom(dev, NULL)) return 1; return 0; } static void oprom_pre_graphics_stall(void) { if (CONFIG_PRE_GRAPHICS_DELAY_MS) mdelay(CONFIG_PRE_GRAPHICS_DELAY_MS); } /** Default handler: only runs the relevant PCI BIOS. */ void pci_dev_init(struct device *dev) { struct rom_header *rom, *ram; if (!CONFIG(VGA_ROM_RUN)) return; /* Only execute VGA ROMs. */ if (((dev->class >> 8) != PCI_CLASS_DISPLAY_VGA)) return; if (!should_load_oprom(dev)) return; timestamp_add_now(TS_OPROM_INITIALIZE); rom = pci_rom_probe(dev); if (rom == NULL) return; ram = pci_rom_load(dev, rom); if (ram == NULL) return; timestamp_add_now(TS_OPROM_COPY_END); if (!should_run_oprom(dev, rom)) return; /* Wait for any configured pre-graphics delay */ oprom_pre_graphics_stall(); run_bios(dev, (unsigned long)ram); gfx_set_init_done(1); printk(BIOS_DEBUG, "VGA Option ROM was run\n"); timestamp_add_now(TS_OPROM_END); } /** Default device operation for PCI devices */ struct pci_operations pci_dev_ops_pci = { .set_subsystem = pci_dev_set_subsystem, }; struct device_operations default_pci_ops_dev = { .read_resources = pci_dev_read_resources, .set_resources = pci_dev_set_resources, .enable_resources = pci_dev_enable_resources, #if CONFIG(HAVE_ACPI_TABLES) .write_acpi_tables = pci_rom_write_acpi_tables, .acpi_fill_ssdt = pci_rom_ssdt, #endif .init = pci_dev_init, .ops_pci = &pci_dev_ops_pci, }; /** Default device operations for PCI bridges */ struct device_operations default_pci_ops_bus = { .read_resources = pci_bus_read_resources, .set_resources = pci_dev_set_resources, .enable_resources = pci_bus_enable_resources, .scan_bus = pci_scan_bridge, .reset_bus = pci_bus_reset, }; /** Default device operations for PCI devices marked 'hidden' */ static struct device_operations default_hidden_pci_ops_dev = { .read_resources = noop_read_resources, .set_resources = noop_set_resources, .scan_bus = scan_static_bus, }; /** * Check for compatibility to route legacy VGA cycles through a bridge. * * Originally, when decoding i/o ports for legacy VGA cycles, bridges * should only consider the 10 least significant bits of the port address. * This means all VGA registers were aliased every 1024 ports! * e.g. 0x3b0 was also decoded as 0x7b0, 0xbb0 etc. * * To avoid this mess, a bridge control bit (VGA16) was introduced in * 2003 to enable decoding of 16-bit port addresses. As we don't want * to make this any more complex for now, we use this bit if possible * and only warn if it's not supported (in set_vga_bridge_bits()). */ static void pci_bridge_vga_compat(struct bus *const bus) { uint16_t bridge_ctrl; bridge_ctrl = pci_read_config16(bus->dev, PCI_BRIDGE_CONTROL); /* Ensure VGA decoding is disabled during probing (it should be by default, but we run blobs nowadays) */ bridge_ctrl &= ~PCI_BRIDGE_CTL_VGA; pci_write_config16(bus->dev, PCI_BRIDGE_CONTROL, bridge_ctrl); /* If the upstream bridge doesn't support VGA16, we don't have to check */ bus->no_vga16 |= bus->dev->upstream->no_vga16; if (bus->no_vga16) return; /* Test if we can enable 16-bit decoding */ bridge_ctrl |= PCI_BRIDGE_CTL_VGA16; pci_write_config16(bus->dev, PCI_BRIDGE_CONTROL, bridge_ctrl); bridge_ctrl = pci_read_config16(bus->dev, PCI_BRIDGE_CONTROL); bus->no_vga16 = !(bridge_ctrl & PCI_BRIDGE_CTL_VGA16); } /** * Detect the type of downstream bridge. * * This function is a heuristic to detect which type of bus is downstream * of a PCI-to-PCI bridge. This functions by looking for various capability * blocks to figure out the type of downstream bridge. PCI-X, PCI-E, and * Hypertransport all seem to have appropriate capabilities. * * When only a PCI-Express capability is found the type is examined to see * which type of bridge we have. * * @param dev Pointer to the device structure of the bridge. * @return Appropriate bridge operations. */ static struct device_operations *get_pci_bridge_ops(struct device *dev) { #if CONFIG(PCIX_PLUGIN_SUPPORT) unsigned int pcixpos; pcixpos = pci_find_capability(dev, PCI_CAP_ID_PCIX); if (pcixpos) { printk(BIOS_DEBUG, "%s subordinate bus PCI-X\n", dev_path(dev)); return &default_pcix_ops_bus; } #endif #if CONFIG(PCIEXP_PLUGIN_SUPPORT) unsigned int pciexpos; pciexpos = pci_find_capability(dev, PCI_CAP_ID_PCIE); if (pciexpos) { u16 flags; flags = pci_read_config16(dev, pciexpos + PCI_EXP_FLAGS); switch ((flags & PCI_EXP_FLAGS_TYPE) >> 4) { case PCI_EXP_TYPE_ROOT_PORT: case PCI_EXP_TYPE_UPSTREAM: case PCI_EXP_TYPE_DOWNSTREAM: printk(BIOS_DEBUG, "%s subordinate bus PCI Express\n", dev_path(dev)); if (CONFIG(PCIEXP_HOTPLUG)) { u16 sltcap; sltcap = pci_read_config16(dev, pciexpos + PCI_EXP_SLTCAP); if (sltcap & PCI_EXP_SLTCAP_HPC) { printk(BIOS_DEBUG, "%s hot-plug capable\n", dev_path(dev)); return &default_pciexp_hotplug_ops_bus; } } return &default_pciexp_ops_bus; case PCI_EXP_TYPE_PCI_BRIDGE: printk(BIOS_DEBUG, "%s subordinate PCI\n", dev_path(dev)); return &default_pci_ops_bus; default: break; } } #endif return &default_pci_ops_bus; } /** * Check if a device id matches a PCI driver entry. * * The driver entry can either point at a zero terminated array of acceptable * device IDs, or include a single device ID. * * @param driver pointer to the PCI driver entry being checked * @param device_id PCI device ID of the device being matched */ static int device_id_match(struct pci_driver *driver, unsigned short device_id) { if (driver->devices) { unsigned short check_id; const unsigned short *device_list = driver->devices; while ((check_id = *device_list++) != 0) if (check_id == device_id) return 1; } return (driver->device == device_id); } /** * Set up PCI device operation. * * Check if it already has a driver. If not, use find_device_operations(), * or set to a default based on type. * * @param dev Pointer to the device whose pci_ops you want to set. * @see pci_drivers */ static void set_pci_ops(struct device *dev) { struct pci_driver *driver; if (dev->ops) return; /* * Look through the list of setup drivers and find one for * this PCI device. */ for (driver = &_pci_drivers[0]; driver != &_epci_drivers[0]; driver++) { if ((driver->vendor == dev->vendor) && device_id_match(driver, dev->device)) { dev->ops = (struct device_operations *)driver->ops; break; } } if (dev->ops) { printk(BIOS_SPEW, "%s [%04x/%04x] %sops\n", dev_path(dev), driver->vendor, driver->device, (driver->ops->scan_bus ? "bus " : "")); return; } /* If I don't have a specific driver use the default operations. */ switch (dev->hdr_type & 0x7f) { /* Header type */ case PCI_HEADER_TYPE_NORMAL: if ((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) goto bad; dev->ops = &default_pci_ops_dev; break; case PCI_HEADER_TYPE_BRIDGE: if ((dev->class >> 8) != PCI_CLASS_BRIDGE_PCI) goto bad; dev->ops = get_pci_bridge_ops(dev); break; #if CONFIG(CARDBUS_PLUGIN_SUPPORT) case PCI_HEADER_TYPE_CARDBUS: dev->ops = &default_cardbus_ops_bus; break; #endif default: bad: if (dev->enabled) { printk(BIOS_ERR, "%s [%04x/%04x/%06x] has unknown header type %02x, ignoring.\n", dev_path(dev), dev->vendor, dev->device, dev->class >> 8, dev->hdr_type); } } } /** * See if we have already allocated a device structure for a given devfn. * * Given a PCI bus structure and a devfn number, find the device structure * corresponding to the devfn, if present. Then move the device structure * as the last child on the bus. * * @param bus Pointer to the bus structure. * @param devfn A device/function number. * @return Pointer to the device structure found or NULL if we have not * allocated a device for this devfn yet. */ static struct device *pci_scan_get_dev(struct bus *bus, unsigned int devfn) { struct device *dev, **prev; prev = &bus->children; for (dev = bus->children; dev; dev = dev->sibling) { if (dev->path.type == DEVICE_PATH_PCI && dev->path.pci.devfn == devfn) { /* Unlink from the list. */ *prev = dev->sibling; dev->sibling = NULL; break; } prev = &dev->sibling; } /* * Just like alloc_dev() add the device to the list of devices on the * bus. When the list of devices was formed we removed all of the * parents children, and now we are interleaving static and dynamic * devices in order on the bus. */ if (dev) { struct device *child; /* Find the last child on the bus. */ for (child = bus->children; child && child->sibling;) child = child->sibling; /* Place the device as last on the bus. */ if (child) child->sibling = dev; else bus->children = dev; } return dev; } /** * Scan a PCI bus. * * Determine the existence of a given PCI device. Allocate a new struct device * if dev==NULL was passed in and the device exists in hardware. * * @param dev Pointer to the dev structure. * @param bus Pointer to the bus structure. * @param devfn A device/function number to look at. * @return The device structure for the device (if found), NULL otherwise. */ struct device *pci_probe_dev(struct device *dev, struct bus *bus, unsigned int devfn) { u32 id, class; u8 hdr_type; /* Detect if a device is present. */ if (!dev) { struct device dummy; dummy.upstream = bus; dummy.path.type = DEVICE_PATH_PCI; dummy.path.pci.devfn = devfn; id = pci_read_config32(&dummy, PCI_VENDOR_ID); /* * Have we found something? Some broken boards return 0 if a * slot is empty, but the expected answer is 0xffffffff. */ if (id == 0xffffffff) return NULL; if ((id == 0x00000000) || (id == 0x0000ffff) || (id == 0xffff0000)) { printk(BIOS_SPEW, "%s, bad id 0x%x\n", dev_path(&dummy), id); return NULL; } dev = alloc_dev(bus, &dummy.path); } else { /* * Enable/disable the device. Once we have found the device- * specific operations this operations we will disable the * device with those as well. * * This is geared toward devices that have subfunctions * that do not show up by default. * * If a device is a stuff option on the motherboard * it may be absent and enable_dev() must cope. */ /* Run the magic enable sequence for the device. */ if (dev->chip_ops && dev->chip_ops->enable_dev) dev->chip_ops->enable_dev(dev); /* Now read the vendor and device ID. */ id = pci_read_config32(dev, PCI_VENDOR_ID); /* * If the device does not have a PCI ID disable it. Possibly * this is because we have already disabled the device. But * this also handles optional devices that may not always * show up. */ /* If the chain is fully enumerated quit */ if ((id == 0xffffffff) || (id == 0x00000000) || (id == 0x0000ffff) || (id == 0xffff0000)) { if (dev->enabled) { printk(BIOS_INFO, "PCI: Static device %s not found, disabling it.\n", dev_path(dev)); dev->enabled = 0; } return dev; } } /* Read the rest of the PCI configuration information. */ hdr_type = pci_read_config8(dev, PCI_HEADER_TYPE); class = pci_read_config32(dev, PCI_CLASS_REVISION); /* Store the interesting information in the device structure. */ dev->vendor = id & 0xffff; dev->device = (id >> 16) & 0xffff; dev->hdr_type = hdr_type; /* Class code, the upper 3 bytes of PCI_CLASS_REVISION. */ dev->class = class >> 8; /* Architectural/System devices always need to be bus masters. */ if ((dev->class >> 16) == PCI_BASE_CLASS_SYSTEM && CONFIG(PCI_ALLOW_BUS_MASTER_ANY_DEVICE)) dev->command |= PCI_COMMAND_MASTER; /* * Look at the vendor and device ID, or at least the header type and * class and figure out which set of configuration methods to use. * Unless we already have some PCI ops. */ set_pci_ops(dev); /* Now run the magic enable/disable sequence for the device. */ if (dev->ops && dev->ops->enable) dev->ops->enable(dev); /* Display the device. */ printk(BIOS_DEBUG, "%s [%04x/%04x] %s%s\n", dev_path(dev), dev->vendor, dev->device, dev->enabled ? "enabled" : "disabled", dev->ops ? "" : " No operations"); return dev; } /** * Test for match between romstage and ramstage device instance. * * @param dev Pointer to the device structure. * @param sdev Simple device model identifier, created with PCI_DEV(). * @return Non-zero if bus:dev.fn of device matches. */ unsigned int pci_match_simple_dev(struct device *dev, pci_devfn_t sdev) { return dev->upstream->secondary == PCI_DEV2BUS(sdev) && dev->upstream->segment_group == PCI_DEV2SEG(sdev) && dev->path.pci.devfn == PCI_DEV2DEVFN(sdev); } /** * Test whether a capability is available along the whole path from the given * device to the host bridge. * * @param dev Pointer to the device structure. * @param cap PCI_CAP_LIST_ID of the PCI capability we're looking for. * @return The next matching capability of the given device, if it is available * along the whole path, or zero if not. */ uint16_t pci_find_cap_recursive(const struct device *dev, uint16_t cap) { assert(dev->upstream); uint16_t pos = pci_find_capability(dev, cap); const struct device *bridge = dev->upstream->dev; while (bridge && (bridge->path.type == DEVICE_PATH_PCI)) { assert(bridge->upstream); if (!pci_find_capability(bridge, cap)) return 0; bridge = bridge->upstream->dev; } return pos; } /** * PCI devices that are marked as "hidden" do not get probed. However, the same * initialization logic is still performed as if it were. This is useful when * devices would like to be described in the devicetree.cb file, and/or present * static PCI resources to the allocator, but the platform firmware hides the * device (makes the device invisible to PCI enumeration) before PCI enumeration * takes place. * * The expected semantics of PCI devices marked as 'hidden': * 1) The device is actually present under the specified BDF * 2) The device config space can still be accessed somehow, but the Vendor ID * indicates there is no device there (it reads as 0xffffffff). * 3) The device may still consume PCI resources. Typically, these would have * been hardcoded elsewhere. * * @param dev Pointer to the device structure. */ static void pci_scan_hidden_device(struct device *dev) { if (dev->chip_ops && dev->chip_ops->enable_dev) dev->chip_ops->enable_dev(dev); /* * If chip_ops->enable_dev did not set dev->ops, then set to a default * .ops, because PCI enumeration is effectively being skipped, therefore * no PCI driver will bind to this device. However, children may want to * be enumerated, so this provides scan_static_bus for the .scan_bus * callback. */ if (dev->ops == NULL) dev->ops = &default_hidden_pci_ops_dev; if (dev->ops->enable) dev->ops->enable(dev); /* Display the device almost as if it were probed normally */ printk(BIOS_DEBUG, "%s [0000/%04x] hidden%s\n", dev_path(dev), dev->device, dev->ops ? "" : " No operations"); } /** * A PCIe Downstream Port normally leads to a Link with only Device 0 on it * (PCIe spec r5.0, sec 7.3.1). As an optimization, scan only for Device 0 in * that situation. * * @param bus Pointer to the bus structure. */ static bool pci_bus_only_one_child(struct bus *bus) { struct device *bridge = bus->dev; u16 pcie_pos, pcie_flags_reg; int pcie_type; if (!bridge) return false; if (bridge->path.type != DEVICE_PATH_PCI) return false; pcie_pos = pci_find_capability(bridge, PCI_CAP_ID_PCIE); if (!pcie_pos) return false; pcie_flags_reg = pci_read_config16(bridge, pcie_pos + PCI_EXP_FLAGS); pcie_type = (pcie_flags_reg & PCI_EXP_FLAGS_TYPE) >> 4; return pciexp_is_downstream_port(pcie_type); } /** * Scan a PCI bus. * * Determine the existence of devices and bridges on a PCI bus. If there are * bridges on the bus, recursively scan the buses behind the bridges. * * @param bus Pointer to the bus structure. * @param min_devfn Minimum devfn to look at in the scan, usually 0x00. * @param max_devfn Maximum devfn to look at in the scan, usually 0xff. */ void pci_scan_bus(struct bus *bus, unsigned int min_devfn, unsigned int max_devfn) { unsigned int devfn; struct device *dev, **prev; int once = 0; printk(BIOS_DEBUG, "PCI: %s for segment group %02x bus %02x\n", __func__, bus->segment_group, bus->secondary); /* Maximum sane devfn is 0xFF. */ if (max_devfn > 0xff) { printk(BIOS_ERR, "PCI: %s limits devfn %x - devfn %x\n", __func__, min_devfn, max_devfn); printk(BIOS_ERR, "PCI: %s upper limit too big. Using 0xff.\n", __func__); max_devfn=0xff; } post_code(POSTCODE_ENTER_PCI_SCAN_BUS); if (pci_bus_only_one_child(bus)) max_devfn = MIN(max_devfn, 0x07); /* * Probe all devices/functions on this bus with some optimization for * non-existence and single function devices. */ for (devfn = min_devfn; devfn <= max_devfn; devfn++) { if (CONFIG(MINIMAL_PCI_SCANNING)) { dev = pcidev_path_behind(bus, devfn); if (!dev || !dev->mandatory) continue; } /* First thing setup the device structure. */ dev = pci_scan_get_dev(bus, devfn); /* Devices marked 'hidden' do not get probed */ if (dev && dev->hidden) { pci_scan_hidden_device(dev); /* Skip pci_probe_dev, go to next devfn */ continue; } /* See if a device is present and setup the device structure. */ dev = pci_probe_dev(dev, bus, devfn); /* * If this is not a multi function device, or the device is * not present don't waste time probing another function. * Skip to next device. */ if ((PCI_FUNC(devfn) == 0x00) && (!dev || (dev->enabled && ((dev->hdr_type & 0x80) != 0x80)))) { devfn += 0x07; } } /* * Warn if any leftover static devices are found. * There's probably a problem in devicetree.cb. */ prev = &bus->children; for (dev = bus->children; dev; dev = dev->sibling) { /* * If static device is not PCI then enable it here and don't * treat it as a leftover device. */ if (dev->path.type != DEVICE_PATH_PCI) { enable_static_device(dev); continue; } /* * The device is only considered leftover if it is not hidden * and it has a Vendor ID of 0 (the default for a device that * could not be probed). */ if (dev->vendor != 0 || dev->hidden) { prev = &dev->sibling; continue; } /* Unlink it from list. */ *prev = dev->sibling; if (!once++) printk(BIOS_WARNING, "PCI: Leftover static devices:\n"); printk(BIOS_WARNING, "%s\n", dev_path(dev)); } if (once) printk(BIOS_WARNING, "PCI: Check your devicetree.cb.\n"); /* * For all children that implement scan_bus() (i.e. bridges) * scan the bus behind that child. */ scan_bridges(bus); /* * 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. */ post_code(POSTCODE_EXIT_PCI_SCAN_BUS); } typedef enum { PCI_ROUTE_CLOSE, PCI_ROUTE_SCAN, PCI_ROUTE_FINAL, } scan_state; static void pci_bridge_route(struct bus *link, scan_state state) { struct device *dev = link->dev; struct bus *parent = dev->upstream; uint8_t primary, secondary, subordinate; if (state == PCI_ROUTE_SCAN) { link->secondary = parent->subordinate + 1; link->subordinate = link->secondary + dev->hotplug_buses; link->max_subordinate = parent->max_subordinate ? parent->max_subordinate : (PCI_BUSES_PER_SEGMENT_GROUP - 1); link->segment_group = parent->segment_group; } if (link->secondary > link->max_subordinate) die("%s: No more busses available!\n", __func__); /* This ought to only happen with hotplug buses. */ if (link->subordinate > link->max_subordinate) { printk(BIOS_WARNING, "%s: Limiting subordinate busses\n", __func__); link->subordinate = link->max_subordinate; } if (state == PCI_ROUTE_CLOSE) { primary = 0; secondary = 0xff; subordinate = 0xfe; } else if (state == PCI_ROUTE_SCAN) { primary = parent->secondary; secondary = link->secondary; subordinate = link->max_subordinate; } else if (state == PCI_ROUTE_FINAL) { primary = parent->secondary; secondary = link->secondary; subordinate = link->subordinate; } else { return; } if (state == PCI_ROUTE_SCAN) { /* Clear all status bits and turn off memory, I/O and master enables. */ link->bridge_cmd = pci_read_config16(dev, PCI_COMMAND); pci_write_config16(dev, PCI_COMMAND, 0x0000); pci_write_config16(dev, PCI_STATUS, 0xffff); } /* * Configure the bus numbers for this bridge: the configuration * transactions will not be propagated by the bridge if it is not * correctly configured. */ pci_write_config8(dev, PCI_PRIMARY_BUS, primary); pci_write_config8(dev, PCI_SECONDARY_BUS, secondary); pci_write_config8(dev, PCI_SUBORDINATE_BUS, subordinate); if (state == PCI_ROUTE_FINAL) { pci_write_config16(dev, PCI_COMMAND, link->bridge_cmd); parent->subordinate = link->subordinate; } } /** * Scan a PCI bridge and the buses behind the bridge. * * Determine the existence of buses behind the bridge. Set up the bridge * according to the result of the scan. * * This function is the default scan_bus() method for PCI bridge devices. * * @param dev Pointer to the bridge device. * @param do_scan_bus TODO */ void do_pci_scan_bridge(struct device *dev, void (*do_scan_bus) (struct bus * bus, unsigned int min_devfn, unsigned int max_devfn)) { struct bus *bus; printk(BIOS_SPEW, "%s for %s\n", __func__, dev_path(dev)); if (dev->downstream == NULL) { struct bus *link; link = malloc(sizeof(*link)); if (link == NULL) die("Couldn't allocate a link!\n"); memset(link, 0, sizeof(*link)); link->dev = dev; dev->downstream = link; } bus = dev->downstream; pci_bridge_vga_compat(bus); pci_bridge_route(bus, PCI_ROUTE_SCAN); do_scan_bus(bus, 0x00, 0xff); pci_bridge_route(bus, PCI_ROUTE_FINAL); } /** * Scan a PCI bridge and the buses behind the bridge. * * Determine the existence of buses behind the bridge. Set up the bridge * according to the result of the scan. * * This function is the default scan_bus() method for PCI bridge devices. * * @param dev Pointer to the bridge device. */ void pci_scan_bridge(struct device *dev) { do_pci_scan_bridge(dev, pci_scan_bus); } /** * Scan a PCI domain. * * This function is the default scan_bus() method for PCI domains. * * @param dev Pointer to the domain. */ void pci_host_bridge_scan_bus(struct device *dev) { struct bus *link = dev->downstream; pci_scan_bus(link, PCI_DEVFN(0, 0), 0xff); } void pci_dev_disable_bus_master(const struct device *dev) { pci_update_config16(dev, PCI_COMMAND, ~PCI_COMMAND_MASTER, 0x0); } /** * Take an INT_PIN number (0, 1 - 4) and convert * it to a string ("NO PIN", "PIN A" - "PIN D") * * @param pin PCI Interrupt Pin number (0, 1 - 4) * @return A string corresponding to the pin number or "Invalid" */ const char *pin_to_str(int pin) { const char *str[5] = { "NO PIN", "PIN A", "PIN B", "PIN C", "PIN D", }; if (pin >= 0 && pin <= 4) return str[pin]; else return "Invalid PIN, not 0 - 4"; } /** * Get the PCI INT_PIN swizzle for a device defined as: * pin_parent = (pin_child + devn_child) % 4 + 1 * where PIN A = 1 ... PIN_D = 4 * * Given a PCI device structure 'dev', find the interrupt pin * that will be triggered on its parent bridge device when * generating an interrupt. For example: Device 1:3.2 may * use INT_PIN A but will trigger PIN D on its parent bridge * device. In this case, this function will return 4 (PIN D). * * @param dev A PCI device structure to swizzle interrupt pins for * @param *parent_bridge The PCI device structure for the bridge * device 'dev' is attached to * @return The interrupt pin number (1 - 4) that 'dev' will * trigger when generating an interrupt */ static int swizzle_irq_pins(struct device *dev, struct device **parent_bridge) { struct device *parent; /* Our current device's parent device */ struct device *child; /* The child device of the parent */ uint8_t parent_bus = 0; /* Parent Bus number */ uint16_t parent_devfn = 0; /* Parent Device and Function number */ uint16_t child_devfn = 0; /* Child Device and Function number */ uint8_t swizzled_pin = 0; /* Pin swizzled across a bridge */ /* Start with PIN A = 0 ... D = 3 */ swizzled_pin = pci_read_config8(dev, PCI_INTERRUPT_PIN) - 1; /* While our current device has parent devices */ child = dev; for (parent = child->upstream->dev; parent; parent = parent->upstream->dev) { parent_bus = parent->upstream->secondary; parent_devfn = parent->path.pci.devfn; child_devfn = child->path.pci.devfn; /* Swizzle the INT_PIN for any bridges not on root bus */ swizzled_pin = (PCI_SLOT(child_devfn) + swizzled_pin) % 4; printk(BIOS_SPEW, "\tWith INT_PIN swizzled to %s\n" "\tAttached to bridge device %01X:%02Xh.%02Xh\n", pin_to_str(swizzled_pin + 1), parent_bus, PCI_SLOT(parent_devfn), PCI_FUNC(parent_devfn)); /* Continue until we find the root bus */ if (parent_bus > 0) { /* * We will go on to the next parent so this parent * becomes the child */ child = parent; continue; } else { /* * Found the root bridge device, * fill in the structure and exit */ *parent_bridge = parent; break; } } /* End with PIN A = 1 ... D = 4 */ return swizzled_pin + 1; } /** * Given a device structure 'dev', find its interrupt pin * and its parent bridge 'parent_bdg' device structure. * If it is behind a bridge, it will return the interrupt * pin number (1 - 4) of the parent bridge that the device * interrupt pin has been swizzled to, otherwise it will * return the interrupt pin that is programmed into the * PCI config space of the target device. If 'dev' is * behind a bridge, it will fill in 'parent_bdg' with the * device structure of the bridge it is behind, otherwise * it will copy 'dev' into 'parent_bdg'. * * @param dev A PCI device structure to get interrupt pins for. * @param *parent_bdg The PCI device structure for the bridge * device 'dev' is attached to. * @return The interrupt pin number (1 - 4) that 'dev' will * trigger when generating an interrupt. * Errors: -1 is returned if the device is not enabled * -2 is returned if a parent bridge could not be found. */ int get_pci_irq_pins(struct device *dev, struct device **parent_bdg) { uint8_t bus = 0; /* The bus this device is on */ uint16_t devfn = 0; /* This device's device and function numbers */ uint8_t int_pin = 0; /* Interrupt pin used by the device */ uint8_t target_pin = 0; /* Interrupt pin we want to assign an IRQ to */ /* Make sure this device is enabled */ if (!(dev->enabled && (dev->path.type == DEVICE_PATH_PCI))) return -1; bus = dev->upstream->secondary; devfn = dev->path.pci.devfn; /* Get and validate the interrupt pin used. Only 1-4 are allowed */ int_pin = pci_read_config8(dev, PCI_INTERRUPT_PIN); if (int_pin < 1 || int_pin > 4) return -1; printk(BIOS_SPEW, "PCI IRQ: Found device %01X:%02X.%02X using %s\n", bus, PCI_SLOT(devfn), PCI_FUNC(devfn), pin_to_str(int_pin)); /* If this device is on a bridge, swizzle its INT_PIN */ if (bus) { /* Swizzle its INT_PINs */ target_pin = swizzle_irq_pins(dev, parent_bdg); /* Make sure the swizzle returned valid structures */ if (parent_bdg == NULL) { printk(BIOS_WARNING, "Could not find parent bridge for this device!\n"); return -2; } } else { /* Device is not behind a bridge */ target_pin = int_pin; /* Return its own interrupt pin */ *parent_bdg = dev; /* Return its own structure */ } /* Target pin is the interrupt pin we want to assign an IRQ to */ return target_pin; } #if CONFIG(PC80_SYSTEM) /** * Assign IRQ numbers. * * This function assigns IRQs for all functions contained within the indicated * device address. If the device does not exist or does not require interrupts * then this function has no effect. * * This function should be called for each PCI slot in your system. * * @param dev Pointer to dev structure. * @param pIntAtoD An array of IRQ #s that are assigned to PINTA through PINTD * of this slot. The particular IRQ #s that are passed in depend on the * routing inside your southbridge and on your board. */ void pci_assign_irqs(struct device *dev, const unsigned char pIntAtoD[4]) { u8 slot, line, irq; /* Each device may contain up to eight functions. */ slot = dev->path.pci.devfn >> 3; for (; dev ; dev = dev->sibling) { if (dev->path.pci.devfn >> 3 != slot) break; line = pci_read_config8(dev, PCI_INTERRUPT_PIN); /* PCI spec says all values except 1..4 are reserved. */ if ((line < 1) || (line > 4)) continue; irq = pIntAtoD[line - 1]; printk(BIOS_DEBUG, "Assigning IRQ %d to %s\n", irq, dev_path(dev)); pci_write_config8(dev, PCI_INTERRUPT_LINE, irq); /* Change to level triggered. */ i8259_configure_irq_trigger(irq, IRQ_LEVEL_TRIGGERED); } } #endif