diff options
Diffstat (limited to 'arch/x86/pci/i386.c')
-rw-r--r-- | arch/x86/pci/i386.c | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c new file mode 100644 index 00000000..831971e7 --- /dev/null +++ b/arch/x86/pci/i386.c @@ -0,0 +1,387 @@ +/* + * Low-Level PCI Access for i386 machines + * + * Copyright 1993, 1994 Drew Eckhardt + * Visionary Computing + * (Unix and Linux consulting and custom programming) + * Drew@Colorado.EDU + * +1 (303) 786-7975 + * + * Drew's work was sponsored by: + * iX Multiuser Multitasking Magazine + * Hannover, Germany + * hm@ix.de + * + * Copyright 1997--2000 Martin Mares <mj@ucw.cz> + * + * For more information, please consult the following manuals (look at + * http://www.pcisig.com/ for how to get them): + * + * PCI BIOS Specification + * PCI Local Bus Specification + * PCI to PCI Bridge Specification + * PCI System Design Guide + * + */ + +#include <linux/types.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/pci.h> +#include <linux/init.h> +#include <linux/ioport.h> +#include <linux/errno.h> +#include <linux/bootmem.h> + +#include <asm/pat.h> +#include <asm/e820.h> +#include <asm/pci_x86.h> +#include <asm/io_apic.h> + + +/* + * This list of dynamic mappings is for temporarily maintaining + * original BIOS BAR addresses for possible reinstatement. + */ +struct pcibios_fwaddrmap { + struct list_head list; + struct pci_dev *dev; + resource_size_t fw_addr[DEVICE_COUNT_RESOURCE]; +}; + +static LIST_HEAD(pcibios_fwaddrmappings); +static DEFINE_SPINLOCK(pcibios_fwaddrmap_lock); + +/* Must be called with 'pcibios_fwaddrmap_lock' lock held. */ +static struct pcibios_fwaddrmap *pcibios_fwaddrmap_lookup(struct pci_dev *dev) +{ + struct pcibios_fwaddrmap *map; + + WARN_ON(!spin_is_locked(&pcibios_fwaddrmap_lock)); + + list_for_each_entry(map, &pcibios_fwaddrmappings, list) + if (map->dev == dev) + return map; + + return NULL; +} + +static void +pcibios_save_fw_addr(struct pci_dev *dev, int idx, resource_size_t fw_addr) +{ + unsigned long flags; + struct pcibios_fwaddrmap *map; + + spin_lock_irqsave(&pcibios_fwaddrmap_lock, flags); + map = pcibios_fwaddrmap_lookup(dev); + if (!map) { + spin_unlock_irqrestore(&pcibios_fwaddrmap_lock, flags); + map = kzalloc(sizeof(*map), GFP_KERNEL); + if (!map) + return; + + map->dev = pci_dev_get(dev); + map->fw_addr[idx] = fw_addr; + INIT_LIST_HEAD(&map->list); + + spin_lock_irqsave(&pcibios_fwaddrmap_lock, flags); + list_add_tail(&map->list, &pcibios_fwaddrmappings); + } else + map->fw_addr[idx] = fw_addr; + spin_unlock_irqrestore(&pcibios_fwaddrmap_lock, flags); +} + +resource_size_t pcibios_retrieve_fw_addr(struct pci_dev *dev, int idx) +{ + unsigned long flags; + struct pcibios_fwaddrmap *map; + resource_size_t fw_addr = 0; + + spin_lock_irqsave(&pcibios_fwaddrmap_lock, flags); + map = pcibios_fwaddrmap_lookup(dev); + if (map) + fw_addr = map->fw_addr[idx]; + spin_unlock_irqrestore(&pcibios_fwaddrmap_lock, flags); + + return fw_addr; +} + +static void pcibios_fw_addr_list_del(void) +{ + unsigned long flags; + struct pcibios_fwaddrmap *entry, *next; + + spin_lock_irqsave(&pcibios_fwaddrmap_lock, flags); + list_for_each_entry_safe(entry, next, &pcibios_fwaddrmappings, list) { + list_del(&entry->list); + pci_dev_put(entry->dev); + kfree(entry); + } + spin_unlock_irqrestore(&pcibios_fwaddrmap_lock, flags); +} + +static int +skip_isa_ioresource_align(struct pci_dev *dev) { + + if ((pci_probe & PCI_CAN_SKIP_ISA_ALIGN) && + !(dev->bus->bridge_ctl & PCI_BRIDGE_CTL_ISA)) + return 1; + return 0; +} + +/* + * We need to avoid collisions with `mirrored' VGA ports + * and other strange ISA hardware, so we always want the + * addresses to be allocated in the 0x000-0x0ff region + * modulo 0x400. + * + * Why? Because some silly external IO cards only decode + * the low 10 bits of the IO address. The 0x00-0xff region + * is reserved for motherboard devices that decode all 16 + * bits, so it's ok to allocate at, say, 0x2800-0x28ff, + * but we want to try to avoid allocating at 0x2900-0x2bff + * which might have be mirrored at 0x0100-0x03ff.. + */ +resource_size_t +pcibios_align_resource(void *data, const struct resource *res, + resource_size_t size, resource_size_t align) +{ + struct pci_dev *dev = data; + resource_size_t start = res->start; + + if (res->flags & IORESOURCE_IO) { + if (skip_isa_ioresource_align(dev)) + return start; + if (start & 0x300) + start = (start + 0x3ff) & ~0x3ff; + } + return start; +} +EXPORT_SYMBOL(pcibios_align_resource); + +/* + * Handle resources of PCI devices. If the world were perfect, we could + * just allocate all the resource regions and do nothing more. It isn't. + * On the other hand, we cannot just re-allocate all devices, as it would + * require us to know lots of host bridge internals. So we attempt to + * keep as much of the original configuration as possible, but tweak it + * when it's found to be wrong. + * + * Known BIOS problems we have to work around: + * - I/O or memory regions not configured + * - regions configured, but not enabled in the command register + * - bogus I/O addresses above 64K used + * - expansion ROMs left enabled (this may sound harmless, but given + * the fact the PCI specs explicitly allow address decoders to be + * shared between expansion ROMs and other resource regions, it's + * at least dangerous) + * - bad resource sizes or overlaps with other regions + * + * Our solution: + * (1) Allocate resources for all buses behind PCI-to-PCI bridges. + * This gives us fixed barriers on where we can allocate. + * (2) Allocate resources for all enabled devices. If there is + * a collision, just mark the resource as unallocated. Also + * disable expansion ROMs during this step. + * (3) Try to allocate resources for disabled devices. If the + * resources were assigned correctly, everything goes well, + * if they weren't, they won't disturb allocation of other + * resources. + * (4) Assign new addresses to resources which were either + * not configured at all or misconfigured. If explicitly + * requested by the user, configure expansion ROM address + * as well. + */ + +static void __init pcibios_allocate_bus_resources(struct list_head *bus_list) +{ + struct pci_bus *bus; + struct pci_dev *dev; + int idx; + struct resource *r; + + /* Depth-First Search on bus tree */ + list_for_each_entry(bus, bus_list, node) { + if ((dev = bus->self)) { + for (idx = PCI_BRIDGE_RESOURCES; + idx < PCI_NUM_RESOURCES; idx++) { + r = &dev->resource[idx]; + if (!r->flags) + continue; + if (!r->start || + pci_claim_resource(dev, idx) < 0) { + /* + * Something is wrong with the region. + * Invalidate the resource to prevent + * child resource allocations in this + * range. + */ + r->start = r->end = 0; + r->flags = 0; + } + } + } + pcibios_allocate_bus_resources(&bus->children); + } +} + +struct pci_check_idx_range { + int start; + int end; +}; + +static void __init pcibios_allocate_resources(int pass) +{ + struct pci_dev *dev = NULL; + int idx, disabled, i; + u16 command; + struct resource *r; + + struct pci_check_idx_range idx_range[] = { + { PCI_STD_RESOURCES, PCI_STD_RESOURCE_END }, +#ifdef CONFIG_PCI_IOV + { PCI_IOV_RESOURCES, PCI_IOV_RESOURCE_END }, +#endif + }; + + for_each_pci_dev(dev) { + pci_read_config_word(dev, PCI_COMMAND, &command); + for (i = 0; i < ARRAY_SIZE(idx_range); i++) + for (idx = idx_range[i].start; idx <= idx_range[i].end; idx++) { + r = &dev->resource[idx]; + if (r->parent) /* Already allocated */ + continue; + if (!r->start) /* Address not assigned at all */ + continue; + if (r->flags & IORESOURCE_IO) + disabled = !(command & PCI_COMMAND_IO); + else + disabled = !(command & PCI_COMMAND_MEMORY); + if (pass == disabled) { + dev_dbg(&dev->dev, + "BAR %d: reserving %pr (d=%d, p=%d)\n", + idx, r, disabled, pass); + if (pci_claim_resource(dev, idx) < 0) { + /* We'll assign a new address later */ + pcibios_save_fw_addr(dev, + idx, r->start); + r->end -= r->start; + r->start = 0; + } + } + } + if (!pass) { + r = &dev->resource[PCI_ROM_RESOURCE]; + if (r->flags & IORESOURCE_ROM_ENABLE) { + /* Turn the ROM off, leave the resource region, + * but keep it unregistered. */ + u32 reg; + dev_dbg(&dev->dev, "disabling ROM %pR\n", r); + r->flags &= ~IORESOURCE_ROM_ENABLE; + pci_read_config_dword(dev, + dev->rom_base_reg, ®); + pci_write_config_dword(dev, dev->rom_base_reg, + reg & ~PCI_ROM_ADDRESS_ENABLE); + } + } + } +} + +static int __init pcibios_assign_resources(void) +{ + struct pci_dev *dev = NULL; + struct resource *r; + + if (!(pci_probe & PCI_ASSIGN_ROMS)) { + /* + * Try to use BIOS settings for ROMs, otherwise let + * pci_assign_unassigned_resources() allocate the new + * addresses. + */ + for_each_pci_dev(dev) { + r = &dev->resource[PCI_ROM_RESOURCE]; + if (!r->flags || !r->start) + continue; + if (pci_claim_resource(dev, PCI_ROM_RESOURCE) < 0) { + r->end -= r->start; + r->start = 0; + } + } + } + + pci_assign_unassigned_resources(); + pcibios_fw_addr_list_del(); + + return 0; +} + +void __init pcibios_resource_survey(void) +{ + DBG("PCI: Allocating resources\n"); + pcibios_allocate_bus_resources(&pci_root_buses); + pcibios_allocate_resources(0); + pcibios_allocate_resources(1); + + e820_reserve_resources_late(); + /* + * Insert the IO APIC resources after PCI initialization has + * occurred to handle IO APICS that are mapped in on a BAR in + * PCI space, but before trying to assign unassigned pci res. + */ + ioapic_insert_resources(); +} + +/** + * called in fs_initcall (one below subsys_initcall), + * give a chance for motherboard reserve resources + */ +fs_initcall(pcibios_assign_resources); + +static const struct vm_operations_struct pci_mmap_ops = { + .access = generic_access_phys, +}; + +int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma, + enum pci_mmap_state mmap_state, int write_combine) +{ + unsigned long prot; + + /* I/O space cannot be accessed via normal processor loads and + * stores on this platform. + */ + if (mmap_state == pci_mmap_io) + return -EINVAL; + + prot = pgprot_val(vma->vm_page_prot); + + /* + * Return error if pat is not enabled and write_combine is requested. + * Caller can followup with UC MINUS request and add a WC mtrr if there + * is a free mtrr slot. + */ + if (!pat_enabled && write_combine) + return -EINVAL; + + if (pat_enabled && write_combine) + prot |= _PAGE_CACHE_WC; + else if (pat_enabled || boot_cpu_data.x86 > 3) + /* + * ioremap() and ioremap_nocache() defaults to UC MINUS for now. + * To avoid attribute conflicts, request UC MINUS here + * as well. + */ + prot |= _PAGE_CACHE_UC_MINUS; + + prot |= _PAGE_IOMAP; /* creating a mapping for IO */ + + vma->vm_page_prot = __pgprot(prot); + + if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, + vma->vm_end - vma->vm_start, + vma->vm_page_prot)) + return -EAGAIN; + + vma->vm_ops = &pci_mmap_ops; + + return 0; +} |