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/*
* legacy.c - traditional, old school PCI bus probing
*/
#include <linux/init.h>
#include <linux/pci.h>
#include <asm/pci_x86.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;
}
}
}
}
int __init pci_legacy_init(void)
{
if (!raw_pci_ops) {
printk("PCI: System does not support PCI\n");
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);
return 0;
}
int __init pci_subsys_init(void)
{
/*
* The init function returns an non zero value when
* pci_legacy_init should be invoked.
*/
if (x86_init.pci.init())
pci_legacy_init();
pcibios_fixup_peer_bridges();
pcibios_irq_init();
pcibios_init();
return 0;
}
subsys_initcall(pci_subsys_init);
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