pci-common.c

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/*
 * Contains common pci routines for ALL ppc platform
 * (based on pci_32.c and pci_64.c)
 *
 * Port for PPC64 David Engebretsen, IBM Corp.
 * Contains common pci routines for ppc64 platform, pSeries and iSeries brands.
 *
 * Copyright (C) 2003 Anton Blanchard <[email protected]>, IBM
 *   Rework, based on alpha PCI code.
 *
 * Common pmac/prep/chrp pci routines. -- Cort
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/mm.h>
#include <linux/list.h>
#include <linux/syscalls.h>
#include <linux/irq.h>
#include <linux/vmalloc.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/export.h>

#include <asm/processor.h>
#include <asm/io.h>
#include <asm/pci-bridge.h>
#include <asm/byteorder.h>

static DEFINE_SPINLOCK(hose_spinlock);
LIST_HEAD(hose_list);

/* XXX kill that some day ... */
static int global_phb_number;       /* Global phb counter */

/* ISA Memory physical address */
resource_size_t isa_mem_base;

static struct dma_map_ops *pci_dma_ops = &dma_direct_ops;

unsigned long isa_io_base;
unsigned long pci_dram_offset;
static int pci_bus_count;


void set_pci_dma_ops(struct dma_map_ops *dma_ops)
{
    pci_dma_ops = dma_ops;
}

struct dma_map_ops *get_pci_dma_ops(void)
{
    return pci_dma_ops;
}
EXPORT_SYMBOL(get_pci_dma_ops);

struct pci_controller *pcibios_alloc_controller(struct device_node *dev)
{
    struct pci_controller *phb;

    phb = zalloc_maybe_bootmem(sizeof(struct pci_controller), GFP_KERNEL);
    if (!phb)
        return NULL;
    spin_lock(&hose_spinlock);
    phb->global_number = global_phb_number++;
    list_add_tail(&phb->list_node, &hose_list);
    spin_unlock(&hose_spinlock);
    phb->dn = dev;
    phb->is_dynamic = mem_init_done;
    return phb;
}

void pcibios_free_controller(struct pci_controller *phb)
{
    spin_lock(&hose_spinlock);
    list_del(&phb->list_node);
    spin_unlock(&hose_spinlock);

    if (phb->is_dynamic)
        kfree(phb);
}

static resource_size_t pcibios_io_size(const struct pci_controller *hose)
{
    return resource_size(&hose->io_resource);
}

int pcibios_vaddr_is_ioport(void __iomem *address)
{
    int ret = 0;
    struct pci_controller *hose;
    resource_size_t size;

    spin_lock(&hose_spinlock);
    list_for_each_entry(hose, &hose_list, list_node) {
        size = pcibios_io_size(hose);
        if (address >= hose->io_base_virt &&
            address < (hose->io_base_virt + size)) {
            ret = 1;
            break;
        }
    }
    spin_unlock(&hose_spinlock);
    return ret;
}

unsigned long pci_address_to_pio(phys_addr_t address)
{
    struct pci_controller *hose;
    resource_size_t size;
    unsigned long ret = ~0;

    spin_lock(&hose_spinlock);
    list_for_each_entry(hose, &hose_list, list_node) {
        size = pcibios_io_size(hose);
        if (address >= hose->io_base_phys &&
            address < (hose->io_base_phys + size)) {
            unsigned long base =
                (unsigned long)hose->io_base_virt - _IO_BASE;
            ret = base + (address - hose->io_base_phys);
            break;
        }
    }
    spin_unlock(&hose_spinlock);

    return ret;
}
EXPORT_SYMBOL_GPL(pci_address_to_pio);

/*
 * Return the domain number for this bus.
 */
int pci_domain_nr(struct pci_bus *bus)
{
    struct pci_controller *hose = pci_bus_to_host(bus);

    return hose->global_number;
}
EXPORT_SYMBOL(pci_domain_nr);

/* This routine is meant to be used early during boot, when the
 * PCI bus numbers have not yet been assigned, and you need to
 * issue PCI config cycles to an OF device.
 * It could also be used to "fix" RTAS config cycles if you want
 * to set pci_assign_all_buses to 1 and still use RTAS for PCI
 * config cycles.
 */
struct pci_controller *pci_find_hose_for_OF_device(struct device_node *node)
{
    while (node) {
        struct pci_controller *hose, *tmp;
        list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
            if (hose->dn == node)
                return hose;
        node = node->parent;
    }
    return NULL;
}

static ssize_t pci_show_devspec(struct device *dev,
        struct device_attribute *attr, char *buf)
{
    struct pci_dev *pdev;
    struct device_node *np;

    pdev = to_pci_dev(dev);
    np = pci_device_to_OF_node(pdev);
    if (np == NULL || np->full_name == NULL)
        return 0;
    return sprintf(buf, "%s", np->full_name);
}
static DEVICE_ATTR(devspec, S_IRUGO, pci_show_devspec, NULL);

/* Add sysfs properties */
int pcibios_add_platform_entries(struct pci_dev *pdev)
{
    return device_create_file(&pdev->dev, &dev_attr_devspec);
}

void pcibios_set_master(struct pci_dev *dev)
{
    /* No special bus mastering setup handling */
}

/*
 * Reads the interrupt pin to determine if interrupt is use by card.
 * If the interrupt is used, then gets the interrupt line from the
 * openfirmware and sets it in the pci_dev and pci_config line.
 */
int pci_read_irq_line(struct pci_dev *pci_dev)
{
    struct of_irq oirq;
    unsigned int virq;

    /* The current device-tree that iSeries generates from the HV
     * PCI informations doesn't contain proper interrupt routing,
     * and all the fallback would do is print out crap, so we
     * don't attempt to resolve the interrupts here at all, some
     * iSeries specific fixup does it.
     *
     * In the long run, we will hopefully fix the generated device-tree
     * instead.
     */
    pr_debug("PCI: Try to map irq for %s...\n", pci_name(pci_dev));

#ifdef DEBUG
    memset(&oirq, 0xff, sizeof(oirq));
#endif
    /* Try to get a mapping from the device-tree */
    if (of_irq_map_pci(pci_dev, &oirq)) {
        u8 line, pin;

        /* If that fails, lets fallback to what is in the config
         * space and map that through the default controller. We
         * also set the type to level low since that's what PCI
         * interrupts are. If your platform does differently, then
         * either provide a proper interrupt tree or don't use this
         * function.
         */
        if (pci_read_config_byte(pci_dev, PCI_INTERRUPT_PIN, &pin))
            return -1;
        if (pin == 0)
            return -1;
        if (pci_read_config_byte(pci_dev, PCI_INTERRUPT_LINE, &line) ||
            line == 0xff || line == 0) {
            return -1;
        }
        pr_debug(" No map ! Using line %d (pin %d) from PCI config\n",
             line, pin);

        virq = irq_create_mapping(NULL, line);
        if (virq)
            irq_set_irq_type(virq, IRQ_TYPE_LEVEL_LOW);
    } else {
        pr_debug(" Got one, spec %d cells (0x%08x 0x%08x...) on %s\n",
             oirq.size, oirq.specifier[0], oirq.specifier[1],
             of_node_full_name(oirq.controller));

        virq = irq_create_of_mapping(oirq.controller, oirq.specifier,
                         oirq.size);
    }
    if (!virq) {
        pr_debug(" Failed to map !\n");
        return -1;
    }

    pr_debug(" Mapped to linux irq %d\n", virq);

    pci_dev->irq = virq;

    return 0;
}
EXPORT_SYMBOL(pci_read_irq_line);

/*
 * Platform support for /proc/bus/pci/X/Y mmap()s,
 * modelled on the sparc64 implementation by Dave Miller.
 *  -- paulus.
 */

/*
 * Adjust vm_pgoff of VMA such that it is the physical page offset
 * corresponding to the 32-bit pci bus offset for DEV requested by the user.
 *
 * Basically, the user finds the base address for his device which he wishes
 * to mmap.  They read the 32-bit value from the config space base register,
 * add whatever PAGE_SIZE multiple offset they wish, and feed this into the
 * offset parameter of mmap on /proc/bus/pci/XXX for that device.
 *
 * Returns negative error code on failure, zero on success.
 */
static struct resource *__pci_mmap_make_offset(struct pci_dev *dev,
                           resource_size_t *offset,
                           enum pci_mmap_state mmap_state)
{
    struct pci_controller *hose = pci_bus_to_host(dev->bus);
    unsigned long io_offset = 0;
    int i, res_bit;

    if (hose == 0)
        return NULL;        /* should never happen */

    /* If memory, add on the PCI bridge address offset */
    if (mmap_state == pci_mmap_mem) {
#if 0 /* See comment in pci_resource_to_user() for why this is disabled */
        *offset += hose->pci_mem_offset;
#endif
        res_bit = IORESOURCE_MEM;
    } else {
        io_offset = (unsigned long)hose->io_base_virt - _IO_BASE;
        *offset += io_offset;
        res_bit = IORESOURCE_IO;
    }

    /*
     * Check that the offset requested corresponds to one of the
     * resources of the device.
     */
    for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
        struct resource *rp = &dev->resource[i];
        int flags = rp->flags;

        /* treat ROM as memory (should be already) */
        if (i == PCI_ROM_RESOURCE)
            flags |= IORESOURCE_MEM;

        /* Active and same type? */
        if ((flags & res_bit) == 0)
            continue;

        /* In the range of this resource? */
        if (*offset < (rp->start & PAGE_MASK) || *offset > rp->end)
            continue;

        /* found it! construct the final physical address */
        if (mmap_state == pci_mmap_io)
            *offset += hose->io_base_phys - io_offset;
        return rp;
    }

    return NULL;
}

/*
 * Set vm_page_prot of VMA, as appropriate for this architecture, for a pci
 * device mapping.
 */
static pgprot_t __pci_mmap_set_pgprot(struct pci_dev *dev, struct resource *rp,
                      pgprot_t protection,
                      enum pci_mmap_state mmap_state,
                      int write_combine)
{
    pgprot_t prot = protection;

    /* Write combine is always 0 on non-memory space mappings. On
     * memory space, if the user didn't pass 1, we check for a
     * "prefetchable" resource. This is a bit hackish, but we use
     * this to workaround the inability of /sysfs to provide a write
     * combine bit
     */
    if (mmap_state != pci_mmap_mem)
        write_combine = 0;
    else if (write_combine == 0) {
        if (rp->flags & IORESOURCE_PREFETCH)
            write_combine = 1;
    }

    return pgprot_noncached(prot);
}

/*
 * This one is used by /dev/mem and fbdev who have no clue about the
 * PCI device, it tries to find the PCI device first and calls the
 * above routine
 */
pgprot_t pci_phys_mem_access_prot(struct file *file,
                  unsigned long pfn,
                  unsigned long size,
                  pgprot_t prot)
{
    struct pci_dev *pdev = NULL;
    struct resource *found = NULL;
    resource_size_t offset = ((resource_size_t)pfn) << PAGE_SHIFT;
    int i;

    if (page_is_ram(pfn))
        return prot;

    prot = pgprot_noncached(prot);
    for_each_pci_dev(pdev) {
        for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
            struct resource *rp = &pdev->resource[i];
            int flags = rp->flags;

            /* Active and same type? */
            if ((flags & IORESOURCE_MEM) == 0)
                continue;
            /* In the range of this resource? */
            if (offset < (rp->start & PAGE_MASK) ||
                offset > rp->end)
                continue;
            found = rp;
            break;
        }
        if (found)
            break;
    }
    if (found) {
        if (found->flags & IORESOURCE_PREFETCH)
            prot = pgprot_noncached_wc(prot);
        pci_dev_put(pdev);
    }

    pr_debug("PCI: Non-PCI map for %llx, prot: %lx\n",
         (unsigned long long)offset, pgprot_val(prot));

    return prot;
}

/*
 * Perform the actual remap of the pages for a PCI device mapping, as
 * appropriate for this architecture.  The region in the process to map
 * is described by vm_start and vm_end members of VMA, the base physical
 * address is found in vm_pgoff.
 * The pci device structure is provided so that architectures may make mapping
 * decisions on a per-device or per-bus basis.
 *
 * Returns a negative error code on failure, zero on success.
 */
int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
            enum pci_mmap_state mmap_state, int write_combine)
{
    resource_size_t offset =
        ((resource_size_t)vma->vm_pgoff) << PAGE_SHIFT;
    struct resource *rp;
    int ret;

    rp = __pci_mmap_make_offset(dev, &offset, mmap_state);
    if (rp == NULL)
        return -EINVAL;

    vma->vm_pgoff = offset >> PAGE_SHIFT;
    vma->vm_page_prot = __pci_mmap_set_pgprot(dev, rp,
                          vma->vm_page_prot,
                          mmap_state, write_combine);

    ret = remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
                   vma->vm_end - vma->vm_start, vma->vm_page_prot);

    return ret;
}

/* This provides legacy IO read access on a bus */
int pci_legacy_read(struct pci_bus *bus, loff_t port, u32 *val, size_t size)
{
    unsigned long offset;
    struct pci_controller *hose = pci_bus_to_host(bus);
    struct resource *rp = &hose->io_resource;
    void __iomem *addr;

    /* Check if port can be supported by that bus. We only check
     * the ranges of the PHB though, not the bus itself as the rules
     * for forwarding legacy cycles down bridges are not our problem
     * here. So if the host bridge supports it, we do it.
     */
    offset = (unsigned long)hose->io_base_virt - _IO_BASE;
    offset += port;

    if (!(rp->flags & IORESOURCE_IO))
        return -ENXIO;
    if (offset < rp->start || (offset + size) > rp->end)
        return -ENXIO;
    addr = hose->io_base_virt + port;

    switch (size) {
    case 1:
        *((u8 *)val) = in_8(addr);
        return 1;
    case 2:
        if (port & 1)
            return -EINVAL;
        *((u16 *)val) = in_le16(addr);
        return 2;
    case 4:
        if (port & 3)
            return -EINVAL;
        *((u32 *)val) = in_le32(addr);
        return 4;
    }
    return -EINVAL;
}

/* This provides legacy IO write access on a bus */
int pci_legacy_write(struct pci_bus *bus, loff_t port, u32 val, size_t size)
{
    unsigned long offset;
    struct pci_controller *hose = pci_bus_to_host(bus);
    struct resource *rp = &hose->io_resource;
    void __iomem *addr;

    /* Check if port can be supported by that bus. We only check
     * the ranges of the PHB though, not the bus itself as the rules
     * for forwarding legacy cycles down bridges are not our problem
     * here. So if the host bridge supports it, we do it.
     */
    offset = (unsigned long)hose->io_base_virt - _IO_BASE;
    offset += port;

    if (!(rp->flags & IORESOURCE_IO))
        return -ENXIO;
    if (offset < rp->start || (offset + size) > rp->end)
        return -ENXIO;
    addr = hose->io_base_virt + port;

    /* WARNING: The generic code is idiotic. It gets passed a pointer
     * to what can be a 1, 2 or 4 byte quantity and always reads that
     * as a u32, which means that we have to correct the location of
     * the data read within those 32 bits for size 1 and 2
     */
    switch (size) {
    case 1:
        out_8(addr, val >> 24);
        return 1;
    case 2:
        if (port & 1)
            return -EINVAL;
        out_le16(addr, val >> 16);
        return 2;
    case 4:
        if (port & 3)
            return -EINVAL;
        out_le32(addr, val);
        return 4;
    }
    return -EINVAL;
}

/* This provides legacy IO or memory mmap access on a bus */
int pci_mmap_legacy_page_range(struct pci_bus *bus,
                   struct vm_area_struct *vma,
                   enum pci_mmap_state mmap_state)
{
    struct pci_controller *hose = pci_bus_to_host(bus);
    resource_size_t offset =
        ((resource_size_t)vma->vm_pgoff) << PAGE_SHIFT;
    resource_size_t size = vma->vm_end - vma->vm_start;
    struct resource *rp;

    pr_debug("pci_mmap_legacy_page_range(%04x:%02x, %s @%llx..%llx)\n",
         pci_domain_nr(bus), bus->number,
         mmap_state == pci_mmap_mem ? "MEM" : "IO",
         (unsigned long long)offset,
         (unsigned long long)(offset + size - 1));

    if (mmap_state == pci_mmap_mem) {
        /* Hack alert !
         *
         * Because X is lame and can fail starting if it gets an error
         * trying to mmap legacy_mem (instead of just moving on without
         * legacy memory access) we fake it here by giving it anonymous
         * memory, effectively behaving just like /dev/zero
         */
        if ((offset + size) > hose->isa_mem_size) {
#ifdef CONFIG_MMU
            printk(KERN_DEBUG
                "Process %s (pid:%d) mapped non-existing PCI"
                "legacy memory for 0%04x:%02x\n",
                current->comm, current->pid, pci_domain_nr(bus),
                                bus->number);
#endif
            if (vma->vm_flags & VM_SHARED)
                return shmem_zero_setup(vma);
            return 0;
        }
        offset += hose->isa_mem_phys;
    } else {
        unsigned long io_offset = (unsigned long)hose->io_base_virt - \
                                _IO_BASE;
        unsigned long roffset = offset + io_offset;
        rp = &hose->io_resource;
        if (!(rp->flags & IORESOURCE_IO))
            return -ENXIO;
        if (roffset < rp->start || (roffset + size) > rp->end)
            return -ENXIO;
        offset += hose->io_base_phys;
    }
    pr_debug(" -> mapping phys %llx\n", (unsigned long long)offset);

    vma->vm_pgoff = offset >> PAGE_SHIFT;
    vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
    return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
                   vma->vm_end - vma->vm_start,
                   vma->vm_page_prot);
}

void pci_resource_to_user(const struct pci_dev *dev, int bar,
              const struct resource *rsrc,
              resource_size_t *start, resource_size_t *end)
{
    struct pci_controller *hose = pci_bus_to_host(dev->bus);
    resource_size_t offset = 0;

    if (hose == NULL)
        return;

    if (rsrc->flags & IORESOURCE_IO)
        offset = (unsigned long)hose->io_base_virt - _IO_BASE;

    /* We pass a fully fixed up address to userland for MMIO instead of
     * a BAR value because X is lame and expects to be able to use that
     * to pass to /dev/mem !
     *
     * That means that we'll have potentially 64 bits values where some
     * userland apps only expect 32 (like X itself since it thinks only
     * Sparc has 64 bits MMIO) but if we don't do that, we break it on
     * 32 bits CHRPs :-(
     *
     * Hopefully, the sysfs insterface is immune to that gunk. Once X
     * has been fixed (and the fix spread enough), we can re-enable the
     * 2 lines below and pass down a BAR value to userland. In that case
     * we'll also have to re-enable the matching code in
     * __pci_mmap_make_offset().
     *
     * BenH.
     */
#if 0
    else if (rsrc->flags & IORESOURCE_MEM)
        offset = hose->pci_mem_offset;
#endif

    *start = rsrc->start - offset;
    *end = rsrc->end - offset;
}

void __devinit pci_process_bridge_OF_ranges(struct pci_controller *hose,
                        struct device_node *dev,
                        int primary)
{
    const u32 *ranges;
    int rlen;
    int pna = of_n_addr_cells(dev);
    int np = pna + 5;
    int memno = 0, isa_hole = -1;
    u32 pci_space;
    unsigned long long pci_addr, cpu_addr, pci_next, cpu_next, size;
    unsigned long long isa_mb = 0;
    struct resource *res;

    printk(KERN_INFO "PCI host bridge %s %s ranges:\n",
           dev->full_name, primary ? "(primary)" : "");

    /* Get ranges property */
    ranges = of_get_property(dev, "ranges", &rlen);
    if (ranges == NULL)
        return;

    /* Parse it */
    pr_debug("Parsing ranges property...\n");
    while ((rlen -= np * 4) >= 0) {
        /* Read next ranges element */
        pci_space = ranges[0];
        pci_addr = of_read_number(ranges + 1, 2);
        cpu_addr = of_translate_address(dev, ranges + 3);
        size = of_read_number(ranges + pna + 3, 2);

        pr_debug("pci_space: 0x%08x pci_addr:0x%016llx "
                "cpu_addr:0x%016llx size:0x%016llx\n",
                    pci_space, pci_addr, cpu_addr, size);

        ranges += np;

        /* If we failed translation or got a zero-sized region
         * (some FW try to feed us with non sensical zero sized regions
         * such as power3 which look like some kind of attempt
         * at exposing the VGA memory hole)
         */
        if (cpu_addr == OF_BAD_ADDR || size == 0)
            continue;

        /* Now consume following elements while they are contiguous */
        for (; rlen >= np * sizeof(u32);
             ranges += np, rlen -= np * 4) {
            if (ranges[0] != pci_space)
                break;
            pci_next = of_read_number(ranges + 1, 2);
            cpu_next = of_translate_address(dev, ranges + 3);
            if (pci_next != pci_addr + size ||
                cpu_next != cpu_addr + size)
                break;
            size += of_read_number(ranges + pna + 3, 2);
        }

        /* Act based on address space type */
        res = NULL;
        switch ((pci_space >> 24) & 0x3) {
        case 1:     /* PCI IO space */
            printk(KERN_INFO
                   "  IO 0x%016llx..0x%016llx -> 0x%016llx\n",
                   cpu_addr, cpu_addr + size - 1, pci_addr);

            /* We support only one IO range */
            if (hose->pci_io_size) {
                printk(KERN_INFO
                       " \\--> Skipped (too many) !\n");
                continue;
            }
            /* On 32 bits, limit I/O space to 16MB */
            if (size > 0x01000000)
                size = 0x01000000;

            /* 32 bits needs to map IOs here */
            hose->io_base_virt = ioremap(cpu_addr, size);

            /* Expect trouble if pci_addr is not 0 */
            if (primary)
                isa_io_base =
                    (unsigned long)hose->io_base_virt;
            /* pci_io_size and io_base_phys always represent IO
             * space starting at 0 so we factor in pci_addr
             */
            hose->pci_io_size = pci_addr + size;
            hose->io_base_phys = cpu_addr - pci_addr;

            /* Build resource */
            res = &hose->io_resource;
            res->flags = IORESOURCE_IO;
            res->start = pci_addr;
            break;
        case 2:     /* PCI Memory space */
        case 3:     /* PCI 64 bits Memory space */
            printk(KERN_INFO
                   " MEM 0x%016llx..0x%016llx -> 0x%016llx %s\n",
                   cpu_addr, cpu_addr + size - 1, pci_addr,
                   (pci_space & 0x40000000) ? "Prefetch" : "");

            /* We support only 3 memory ranges */
            if (memno >= 3) {
                printk(KERN_INFO
                       " \\--> Skipped (too many) !\n");
                continue;
            }
            /* Handles ISA memory hole space here */
            if (pci_addr == 0) {
                isa_mb = cpu_addr;
                isa_hole = memno;
                if (primary || isa_mem_base == 0)
                    isa_mem_base = cpu_addr;
                hose->isa_mem_phys = cpu_addr;
                hose->isa_mem_size = size;
            }

            /* We get the PCI/Mem offset from the first range or
             * the, current one if the offset came from an ISA
             * hole. If they don't match, bugger.
             */
            if (memno == 0 ||
                (isa_hole >= 0 && pci_addr != 0 &&
                 hose->pci_mem_offset == isa_mb))
                hose->pci_mem_offset = cpu_addr - pci_addr;
            else if (pci_addr != 0 &&
                 hose->pci_mem_offset != cpu_addr - pci_addr) {
                printk(KERN_INFO
                       " \\--> Skipped (offset mismatch) !\n");
                continue;
            }

            /* Build resource */
            res = &hose->mem_resources[memno++];
            res->flags = IORESOURCE_MEM;
            if (pci_space & 0x40000000)
                res->flags |= IORESOURCE_PREFETCH;
            res->start = cpu_addr;
            break;
        }
        if (res != NULL) {
            res->name = dev->full_name;
            res->end = res->start + size - 1;
            res->parent = NULL;
            res->sibling = NULL;
            res->child = NULL;
        }
    }

    /* If there's an ISA hole and the pci_mem_offset is -not- matching
     * the ISA hole offset, then we need to remove the ISA hole from
     * the resource list for that brige
     */
    if (isa_hole >= 0 && hose->pci_mem_offset != isa_mb) {
        unsigned int next = isa_hole + 1;
        printk(KERN_INFO " Removing ISA hole at 0x%016llx\n", isa_mb);
        if (next < memno)
            memmove(&hose->mem_resources[isa_hole],
                &hose->mem_resources[next],
                sizeof(struct resource) * (memno - next));
        hose->mem_resources[--memno].flags = 0;
    }
}

/* Decide whether to display the domain number in /proc */
int pci_proc_domain(struct pci_bus *bus)
{
    struct pci_controller *hose = pci_bus_to_host(bus);

    return 0;
}

/* This header fixup will do the resource fixup for all devices as they are
 * probed, but not for bridge ranges
 */
static void __devinit pcibios_fixup_resources(struct pci_dev *dev)
{
    struct pci_controller *hose = pci_bus_to_host(dev->bus);
    int i;

    if (!hose) {
        printk(KERN_ERR "No host bridge for PCI dev %s !\n",
               pci_name(dev));
        return;
    }
    for (i = 0; i < DEVICE_COUNT_RESOURCE; i++) {
        struct resource *res = dev->resource + i;
        if (!res->flags)
            continue;
        if (res->start == 0) {
            pr_debug("PCI:%s Resource %d %016llx-%016llx [%x]" \
                            "is unassigned\n",
                 pci_name(dev), i,
                 (unsigned long long)res->start,
                 (unsigned long long)res->end,
                 (unsigned int)res->flags);
            res->end -= res->start;
            res->start = 0;
            res->flags |= IORESOURCE_UNSET;
            continue;
        }

        pr_debug("PCI:%s Resource %d %016llx-%016llx [%x]\n",
             pci_name(dev), i,
             (unsigned long long)res->start,\
             (unsigned long long)res->end,
             (unsigned int)res->flags);
    }
}
DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, pcibios_fixup_resources);

/* This function tries to figure out if a bridge resource has been initialized
 * by the firmware or not. It doesn't have to be absolutely bullet proof, but
 * things go more smoothly when it gets it right. It should covers cases such
 * as Apple "closed" bridge resources and bare-metal pSeries unassigned bridges
 */
static int __devinit pcibios_uninitialized_bridge_resource(struct pci_bus *bus,
                               struct resource *res)
{
    struct pci_controller *hose = pci_bus_to_host(bus);
    struct pci_dev *dev = bus->self;
    resource_size_t offset;
    u16 command;
    int i;

    /* Job is a bit different between memory and IO */
    if (res->flags & IORESOURCE_MEM) {
        /* If the BAR is non-0 (res != pci_mem_offset) then it's
         * probably been initialized by somebody
         */
        if (res->start != hose->pci_mem_offset)
            return 0;

        /* The BAR is 0, let's check if memory decoding is enabled on
         * the bridge. If not, we consider it unassigned
         */
        pci_read_config_word(dev, PCI_COMMAND, &command);
        if ((command & PCI_COMMAND_MEMORY) == 0)
            return 1;

        /* Memory decoding is enabled and the BAR is 0. If any of
         * the bridge resources covers that starting address (0 then
         * it's good enough for us for memory
         */
        for (i = 0; i < 3; i++) {
            if ((hose->mem_resources[i].flags & IORESOURCE_MEM) &&
               hose->mem_resources[i].start == hose->pci_mem_offset)
                return 0;
        }

        /* Well, it starts at 0 and we know it will collide so we may as
         * well consider it as unassigned. That covers the Apple case.
         */
        return 1;
    } else {
        /* If the BAR is non-0, then we consider it assigned */
        offset = (unsigned long)hose->io_base_virt - _IO_BASE;
        if (((res->start - offset) & 0xfffffffful) != 0)
            return 0;

        /* Here, we are a bit different than memory as typically IO
         * space starting at low addresses -is- valid. What we do
         * instead if that we consider as unassigned anything that
         * doesn't have IO enabled in the PCI command register,
         * and that's it.
         */
        pci_read_config_word(dev, PCI_COMMAND, &command);
        if (command & PCI_COMMAND_IO)
            return 0;

        /* It's starting at 0 and IO is disabled in the bridge, consider
         * it unassigned
         */
        return 1;
    }
}

/* Fixup resources of a PCI<->PCI bridge */
static void __devinit pcibios_fixup_bridge(struct pci_bus *bus)
{
    struct resource *res;
    int i;

    struct pci_dev *dev = bus->self;

    pci_bus_for_each_resource(bus, res, i) {
        if (!res)
            continue;
        if (!res->flags)
            continue;
        if (i >= 3 && bus->self->transparent)
            continue;

        pr_debug("PCI:%s Bus rsrc %d %016llx-%016llx [%x] fixup...\n",
             pci_name(dev), i,
             (unsigned long long)res->start,\
             (unsigned long long)res->end,
             (unsigned int)res->flags);

        /* Try to detect uninitialized P2P bridge resources,
         * and clear them out so they get re-assigned later
         */
        if (pcibios_uninitialized_bridge_resource(bus, res)) {
            res->flags = 0;
            pr_debug("PCI:%s            (unassigned)\n",
                                pci_name(dev));
        } else {
            pr_debug("PCI:%s            %016llx-%016llx\n",
                 pci_name(dev),
                 (unsigned long long)res->start,
                 (unsigned long long)res->end);
        }
    }
}

void __devinit pcibios_setup_bus_self(struct pci_bus *bus)
{
    /* Fix up the bus resources for P2P bridges */
    if (bus->self != NULL)
        pcibios_fixup_bridge(bus);
}

void __devinit pcibios_setup_bus_devices(struct pci_bus *bus)
{
    struct pci_dev *dev;

    pr_debug("PCI: Fixup bus devices %d (%s)\n",
         bus->number, bus->self ? pci_name(bus->self) : "PHB");

    list_for_each_entry(dev, &bus->devices, bus_list) {
        /* Setup OF node pointer in archdata */
        dev->dev.of_node = pci_device_to_OF_node(dev);

        /* Fixup NUMA node as it may not be setup yet by the generic
         * code and is needed by the DMA init
         */
        set_dev_node(&dev->dev, pcibus_to_node(dev->bus));

        /* Hook up default DMA ops */
        set_dma_ops(&dev->dev, pci_dma_ops);
        dev->dev.archdata.dma_data = (void *)PCI_DRAM_OFFSET;

        /* Read default IRQs and fixup if necessary */
        pci_read_irq_line(dev);
    }
}

void __devinit pcibios_fixup_bus(struct pci_bus *bus)
{
    /* When called from the generic PCI probe, read PCI<->PCI bridge
     * bases. This is -not- called when generating the PCI tree from
     * the OF device-tree.
     */
    if (bus->self != NULL)
        pci_read_bridge_bases(bus);

    /* Now fixup the bus bus */
    pcibios_setup_bus_self(bus);

    /* Now fixup devices on that bus */
    pcibios_setup_bus_devices(bus);
}
EXPORT_SYMBOL(pcibios_fixup_bus);

static int skip_isa_ioresource_align(struct pci_dev *dev)
{
    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);

/*
 * Reparent resource children of pr that conflict with res
 * under res, and make res replace those children.
 */
static int __init reparent_resources(struct resource *parent,
                     struct resource *res)
{
    struct resource *p, **pp;
    struct resource **firstpp = NULL;

    for (pp = &parent->child; (p = *pp) != NULL; pp = &p->sibling) {
        if (p->end < res->start)
            continue;
        if (res->end < p->start)
            break;
        if (p->start < res->start || p->end > res->end)
            return -1;  /* not completely contained */
        if (firstpp == NULL)
            firstpp = pp;
    }
    if (firstpp == NULL)
        return -1;  /* didn't find any conflicting entries? */
    res->parent = parent;
    res->child = *firstpp;
    res->sibling = *pp;
    *firstpp = res;
    *pp = NULL;
    for (p = res->child; p != NULL; p = p->sibling) {
        p->parent = res;
        pr_debug("PCI: Reparented %s [%llx..%llx] under %s\n",
             p->name,
             (unsigned long long)p->start,
             (unsigned long long)p->end, res->name);
    }
    return 0;
}

/*
 *  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)
 *
 *  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.
 */

void pcibios_allocate_bus_resources(struct pci_bus *bus)
{
    struct pci_bus *b;
    int i;
    struct resource *res, *pr;

    pr_debug("PCI: Allocating bus resources for %04x:%02x...\n",
         pci_domain_nr(bus), bus->number);

    pci_bus_for_each_resource(bus, res, i) {
        if (!res || !res->flags
            || res->start > res->end || res->parent)
            continue;
        if (bus->parent == NULL)
            pr = (res->flags & IORESOURCE_IO) ?
                &ioport_resource : &iomem_resource;
        else {
            /* Don't bother with non-root busses when
             * re-assigning all resources. We clear the
             * resource flags as if they were colliding
             * and as such ensure proper re-allocation
             * later.
             */
            pr = pci_find_parent_resource(bus->self, res);
            if (pr == res) {
                /* this happens when the generic PCI
                 * code (wrongly) decides that this
                 * bridge is transparent  -- paulus
                 */
                continue;
            }
        }

        pr_debug("PCI: %s (bus %d) bridge rsrc %d: %016llx-%016llx "
             "[0x%x], parent %p (%s)\n",
             bus->self ? pci_name(bus->self) : "PHB",
             bus->number, i,
             (unsigned long long)res->start,
             (unsigned long long)res->end,
             (unsigned int)res->flags,
             pr, (pr && pr->name) ? pr->name : "nil");

        if (pr && !(pr->flags & IORESOURCE_UNSET)) {
            if (request_resource(pr, res) == 0)
                continue;
            /*
             * Must be a conflict with an existing entry.
             * Move that entry (or entries) under the
             * bridge resource and try again.
             */
            if (reparent_resources(pr, res) == 0)
                continue;
        }
        printk(KERN_WARNING "PCI: Cannot allocate resource region "
               "%d of PCI bridge %d, will remap\n", i, bus->number);
clear_resource:
        res->start = res->end = 0;
        res->flags = 0;
    }

    list_for_each_entry(b, &bus->children, node)
        pcibios_allocate_bus_resources(b);
}

static inline void __devinit alloc_resource(struct pci_dev *dev, int idx)
{
    struct resource *pr, *r = &dev->resource[idx];

    pr_debug("PCI: Allocating %s: Resource %d: %016llx..%016llx [%x]\n",
         pci_name(dev), idx,
         (unsigned long long)r->start,
         (unsigned long long)r->end,
         (unsigned int)r->flags);

    pr = pci_find_parent_resource(dev, r);
    if (!pr || (pr->flags & IORESOURCE_UNSET) ||
        request_resource(pr, r) < 0) {
        printk(KERN_WARNING "PCI: Cannot allocate resource region %d"
               " of device %s, will remap\n", idx, pci_name(dev));
        if (pr)
            pr_debug("PCI:  parent is %p: %016llx-%016llx [%x]\n",
                 pr,
                 (unsigned long long)pr->start,
                 (unsigned long long)pr->end,
                 (unsigned int)pr->flags);
        /* We'll assign a new address later */
        r->flags |= IORESOURCE_UNSET;
        r->end -= r->start;
        r->start = 0;
    }
}

static void __init pcibios_allocate_resources(int pass)
{
    struct pci_dev *dev = NULL;
    int idx, disabled;
    u16 command;
    struct resource *r;

    for_each_pci_dev(dev) {
        pci_read_config_word(dev, PCI_COMMAND, &command);
        for (idx = 0; idx <= PCI_ROM_RESOURCE; idx++) {
            r = &dev->resource[idx];
            if (r->parent)      /* Already allocated */
                continue;
            if (!r->flags || (r->flags & IORESOURCE_UNSET))
                continue;   /* Not assigned at all */
            /* We only allocate ROMs on pass 1 just in case they
             * have been screwed up by firmware
             */
            if (idx == PCI_ROM_RESOURCE)
                disabled = 1;
            if (r->flags & IORESOURCE_IO)
                disabled = !(command & PCI_COMMAND_IO);
            else
                disabled = !(command & PCI_COMMAND_MEMORY);
            if (pass == disabled)
                alloc_resource(dev, idx);
        }
        if (pass)
            continue;
        r = &dev->resource[PCI_ROM_RESOURCE];
        if (r->flags) {
            /* Turn the ROM off, leave the resource region,
             * but keep it unregistered.
             */
            u32 reg;
            pci_read_config_dword(dev, dev->rom_base_reg, &reg);
            if (reg & PCI_ROM_ADDRESS_ENABLE) {
                pr_debug("PCI: Switching off ROM of %s\n",
                     pci_name(dev));
                r->flags &= ~IORESOURCE_ROM_ENABLE;
                pci_write_config_dword(dev, dev->rom_base_reg,
                        reg & ~PCI_ROM_ADDRESS_ENABLE);
            }
        }
    }
}

static void __init pcibios_reserve_legacy_regions(struct pci_bus *bus)
{
    struct pci_controller *hose = pci_bus_to_host(bus);
    resource_size_t offset;
    struct resource *res, *pres;
    int i;

    pr_debug("Reserving legacy ranges for domain %04x\n",
                            pci_domain_nr(bus));

    /* Check for IO */
    if (!(hose->io_resource.flags & IORESOURCE_IO))
        goto no_io;
    offset = (unsigned long)hose->io_base_virt - _IO_BASE;
    res = kzalloc(sizeof(struct resource), GFP_KERNEL);
    BUG_ON(res == NULL);
    res->name = "Legacy IO";
    res->flags = IORESOURCE_IO;
    res->start = offset;
    res->end = (offset + 0xfff) & 0xfffffffful;
    pr_debug("Candidate legacy IO: %pR\n", res);
    if (request_resource(&hose->io_resource, res)) {
        printk(KERN_DEBUG
               "PCI %04x:%02x Cannot reserve Legacy IO %pR\n",
               pci_domain_nr(bus), bus->number, res);
        kfree(res);
    }

 no_io:
    /* Check for memory */
    offset = hose->pci_mem_offset;
    pr_debug("hose mem offset: %016llx\n", (unsigned long long)offset);
    for (i = 0; i < 3; i++) {
        pres = &hose->mem_resources[i];
        if (!(pres->flags & IORESOURCE_MEM))
            continue;
        pr_debug("hose mem res: %pR\n", pres);
        if ((pres->start - offset) <= 0xa0000 &&
            (pres->end - offset) >= 0xbffff)
            break;
    }
    if (i >= 3)
        return;
    res = kzalloc(sizeof(struct resource), GFP_KERNEL);
    BUG_ON(res == NULL);
    res->name = "Legacy VGA memory";
    res->flags = IORESOURCE_MEM;
    res->start = 0xa0000 + offset;
    res->end = 0xbffff + offset;
    pr_debug("Candidate VGA memory: %pR\n", res);
    if (request_resource(pres, res)) {
        printk(KERN_DEBUG
               "PCI %04x:%02x Cannot reserve VGA memory %pR\n",
               pci_domain_nr(bus), bus->number, res);
        kfree(res);
    }
}

void __init pcibios_resource_survey(void)
{
    struct pci_bus *b;

    /* Allocate and assign resources. If we re-assign everything, then
     * we skip the allocate phase
     */
    list_for_each_entry(b, &pci_root_buses, node)
        pcibios_allocate_bus_resources(b);

    pcibios_allocate_resources(0);
    pcibios_allocate_resources(1);

    /* Before we start assigning unassigned resource, we try to reserve
     * the low IO area and the VGA memory area if they intersect the
     * bus available resources to avoid allocating things on top of them
     */
    list_for_each_entry(b, &pci_root_buses, node)
        pcibios_reserve_legacy_regions(b);

    /* Now proceed to assigning things that were left unassigned */
    pr_debug("PCI: Assigning unassigned resources...\n");
    pci_assign_unassigned_resources();
}

#ifdef CONFIG_HOTPLUG

/* This is used by the PCI hotplug driver to allocate resource
 * of newly plugged busses. We can try to consolidate with the
 * rest of the code later, for now, keep it as-is as our main
 * resource allocation function doesn't deal with sub-trees yet.
 */
void __devinit pcibios_claim_one_bus(struct pci_bus *bus)
{
    struct pci_dev *dev;
    struct pci_bus *child_bus;

    list_for_each_entry(dev, &bus->devices, bus_list) {
        int i;

        for (i = 0; i < PCI_NUM_RESOURCES; i++) {
            struct resource *r = &dev->resource[i];

            if (r->parent || !r->start || !r->flags)
                continue;

            pr_debug("PCI: Claiming %s: "
                 "Resource %d: %016llx..%016llx [%x]\n",
                 pci_name(dev), i,
                 (unsigned long long)r->start,
                 (unsigned long long)r->end,
                 (unsigned int)r->flags);

            pci_claim_resource(dev, i);
        }
    }

    list_for_each_entry(child_bus, &bus->children, node)
        pcibios_claim_one_bus(child_bus);
}
EXPORT_SYMBOL_GPL(pcibios_claim_one_bus);


/* pcibios_finish_adding_to_bus
 *
 * This is to be called by the hotplug code after devices have been
 * added to a bus, this include calling it for a PHB that is just
 * being added
 */
void pcibios_finish_adding_to_bus(struct pci_bus *bus)
{
    pr_debug("PCI: Finishing adding to hotplug bus %04x:%02x\n",
         pci_domain_nr(bus), bus->number);

    /* Allocate bus and devices resources */
    pcibios_allocate_bus_resources(bus);
    pcibios_claim_one_bus(bus);

    /* Add new devices to global lists.  Register in proc, sysfs. */
    pci_bus_add_devices(bus);

    /* Fixup EEH */
    /* eeh_add_device_tree_late(bus); */
}
EXPORT_SYMBOL_GPL(pcibios_finish_adding_to_bus);

#endif /* CONFIG_HOTPLUG */

int pcibios_enable_device(struct pci_dev *dev, int mask)
{
    return pci_enable_resources(dev, mask);
}

static void __devinit pcibios_setup_phb_resources(struct pci_controller *hose, struct list_head *resources)
{
    unsigned long io_offset;
    struct resource *res;
    int i;

    /* Hookup PHB IO resource */
    res = &hose->io_resource;

    /* Fixup IO space offset */
    io_offset = (unsigned long)hose->io_base_virt - isa_io_base;
    res->start = (res->start + io_offset) & 0xffffffffu;
    res->end = (res->end + io_offset) & 0xffffffffu;

    if (!res->flags) {
        printk(KERN_WARNING "PCI: I/O resource not set for host"
               " bridge %s (domain %d)\n",
               hose->dn->full_name, hose->global_number);
        /* Workaround for lack of IO resource only on 32-bit */
        res->start = (unsigned long)hose->io_base_virt - isa_io_base;
        res->end = res->start + IO_SPACE_LIMIT;
        res->flags = IORESOURCE_IO;
    }
    pci_add_resource_offset(resources, res, hose->io_base_virt - _IO_BASE);

    pr_debug("PCI: PHB IO resource    = %016llx-%016llx [%lx]\n",
         (unsigned long long)res->start,
         (unsigned long long)res->end,
         (unsigned long)res->flags);

    /* Hookup PHB Memory resources */
    for (i = 0; i < 3; ++i) {
        res = &hose->mem_resources[i];
        if (!res->flags) {
            if (i > 0)
                continue;
            printk(KERN_ERR "PCI: Memory resource 0 not set for "
                   "host bridge %s (domain %d)\n",
                   hose->dn->full_name, hose->global_number);

            /* Workaround for lack of MEM resource only on 32-bit */
            res->start = hose->pci_mem_offset;
            res->end = (resource_size_t)-1LL;
            res->flags = IORESOURCE_MEM;

        }
        pci_add_resource_offset(resources, res, hose->pci_mem_offset);

        pr_debug("PCI: PHB MEM resource %d = %016llx-%016llx [%lx]\n",
            i, (unsigned long long)res->start,
            (unsigned long long)res->end,
            (unsigned long)res->flags);
    }

    pr_debug("PCI: PHB MEM offset     = %016llx\n",
         (unsigned long long)hose->pci_mem_offset);
    pr_debug("PCI: PHB IO  offset     = %08lx\n",
         (unsigned long)hose->io_base_virt - _IO_BASE);
}

struct device_node *pcibios_get_phb_of_node(struct pci_bus *bus)
{
    struct pci_controller *hose = bus->sysdata;

    return of_node_get(hose->dn);
}

static void __devinit pcibios_scan_phb(struct pci_controller *hose)
{
    LIST_HEAD(resources);
    struct pci_bus *bus;
    struct device_node *node = hose->dn;

    pr_debug("PCI: Scanning PHB %s\n", of_node_full_name(node));

    pcibios_setup_phb_resources(hose, &resources);

    bus = pci_scan_root_bus(hose->parent, hose->first_busno,
                hose->ops, hose, &resources);
    if (bus == NULL) {
        printk(KERN_ERR "Failed to create bus for PCI domain %04x\n",
               hose->global_number);
        pci_free_resource_list(&resources);
        return;
    }
    bus->busn_res.start = hose->first_busno;
    hose->bus = bus;

    hose->last_busno = bus->busn_res.end;
}

static int __init pcibios_init(void)
{
    struct pci_controller *hose, *tmp;
    int next_busno = 0;

    printk(KERN_INFO "PCI: Probing PCI hardware\n");

    /* Scan all of the recorded PCI controllers.  */
    list_for_each_entry_safe(hose, tmp, &hose_list, list_node) {
        hose->last_busno = 0xff;
        pcibios_scan_phb(hose);
        if (next_busno <= hose->last_busno)
            next_busno = hose->last_busno + 1;
    }
    pci_bus_count = next_busno;

    /* Call common code to handle resource allocation */
    pcibios_resource_survey();

    return 0;
}

subsys_initcall(pcibios_init);

static struct pci_controller *pci_bus_to_hose(int bus)
{
    struct pci_controller *hose, *tmp;

    list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
        if (bus >= hose->first_busno && bus <= hose->last_busno)
            return hose;
    return NULL;
}

/* Provide information on locations of various I/O regions in physical
 * memory.  Do this on a per-card basis so that we choose the right
 * root bridge.
 * Note that the returned IO or memory base is a physical address
 */

long sys_pciconfig_iobase(long which, unsigned long bus, unsigned long devfn)
{
    struct pci_controller *hose;
    long result = -EOPNOTSUPP;

    hose = pci_bus_to_hose(bus);
    if (!hose)
        return -ENODEV;

    switch (which) {
    case IOBASE_BRIDGE_NUMBER:
        return (long)hose->first_busno;
    case IOBASE_MEMORY:
        return (long)hose->pci_mem_offset;
    case IOBASE_IO:
        return (long)hose->io_base_phys;
    case IOBASE_ISA_IO:
        return (long)isa_io_base;
    case IOBASE_ISA_MEM:
        return (long)isa_mem_base;
    }

    return result;
}

/*
 * Null PCI config access functions, for the case when we can't
 * find a hose.
 */
#define NULL_PCI_OP(rw, size, type)                 \
static int                              \
null_##rw##_config_##size(struct pci_dev *dev, int offset, type val)    \
{                                   \
    return PCIBIOS_DEVICE_NOT_FOUND;                \
}

static int
null_read_config(struct pci_bus *bus, unsigned int devfn, int offset,
         int len, u32 *val)
{
    return PCIBIOS_DEVICE_NOT_FOUND;
}

static int
null_write_config(struct pci_bus *bus, unsigned int devfn, int offset,
          int len, u32 val)
{
    return PCIBIOS_DEVICE_NOT_FOUND;
}

static struct pci_ops null_pci_ops = {
    .read = null_read_config,
    .write = null_write_config,
};

/*
 * These functions are used early on before PCI scanning is done
 * and all of the pci_dev and pci_bus structures have been created.
 */
static struct pci_bus *
fake_pci_bus(struct pci_controller *hose, int busnr)
{
    static struct pci_bus bus;

    if (!hose)
        printk(KERN_ERR "Can't find hose for PCI bus %d!\n", busnr);

    bus.number = busnr;
    bus.sysdata = hose;
    bus.ops = hose ? hose->ops : &null_pci_ops;
    return &bus;
}

#define EARLY_PCI_OP(rw, size, type)                    \
int early_##rw##_config_##size(struct pci_controller *hose, int bus,    \
                   int devfn, int offset, type value)   \
{                                   \
    return pci_bus_##rw##_config_##size(fake_pci_bus(hose, bus),    \
                        devfn, offset, value);  \
}

EARLY_PCI_OP(read, byte, u8 *)
EARLY_PCI_OP(read, word, u16 *)
EARLY_PCI_OP(read, dword, u32 *)
EARLY_PCI_OP(write, byte, u8)
EARLY_PCI_OP(write, word, u16)
EARLY_PCI_OP(write, dword, u32)

int early_find_capability(struct pci_controller *hose, int bus, int devfn,
              int cap)
{
    return pci_bus_find_capability(fake_pci_bus(hose, bus), devfn, cap);
}