root/arch/x86/pci/legacy.c

DEFINITIONS

1. pcibios_fixup_peer_bridges
2. pci_legacy_init
3. pci_subsys_init

/*
 * legacy.c - traditional, old school PCI bus probing
 */
#include <linux/init.h>
#include <linux/pci.h>
#include "pci.h"

/*
 * Discover remaining PCI buses in case there are peer host bridges.
 * We use the number of last PCI bus provided by the PCI BIOS.
 */
static void __devinit pcibios_fixup_peer_bridges(void)
{
        int n, devfn;
        long node;

        if (pcibios_last_bus <= 0 || pcibios_last_bus > 0xff)
                return;
        DBG("PCI: Peer bridge fixup\n");

        for (n=0; n <= pcibios_last_bus; n++) {
                u32 l;
                if (pci_find_bus(0, n))
                        continue;
                node = get_mp_bus_to_node(n);
                for (devfn = 0; devfn < 256; devfn += 8) {
                        if (!raw_pci_read(0, n, devfn, PCI_VENDOR_ID, 2, &l) &&
                            l != 0x0000 && l != 0xffff) {
                                DBG("Found device at %02x:%02x [%04x]\n", n, devfn, l);
                                printk(KERN_INFO "PCI: Discovered peer bus %02x\n", n);
                                pci_scan_bus_on_node(n, &pci_root_ops, node);
                                break;
                        }
                }
        }
}

static int __init pci_legacy_init(void)
{
        if (!raw_pci_ops) {
                printk("PCI: System does not support PCI\n");
                return 0;
        }

        if (pcibios_scanned++)
                return 0;

        printk("PCI: Probing PCI hardware\n");
        pci_root_bus = pcibios_scan_root(0);
        if (pci_root_bus)
                pci_bus_add_devices(pci_root_bus);

        pcibios_fixup_peer_bridges();

        return 0;
}

int __init pci_subsys_init(void)
{
#ifdef CONFIG_X86_NUMAQ
        pci_numaq_init();
#endif
#ifdef CONFIG_ACPI
        pci_acpi_init();
#endif
#ifdef CONFIG_X86_VISWS
        pci_visws_init();
#endif
        pci_legacy_init();
        pcibios_irq_init();
        pcibios_init();

        return 0;
}
subsys_initcall(pci_subsys_init);