2 * legacy.c - traditional, old school PCI bus probing
4 #include <linux/init.h>
5 #include <linux/export.h>
7 #include <asm/pci_x86.h>
10 * Discover remaining PCI buses in case there are peer host bridges.
11 * We use the number of last PCI bus provided by the PCI BIOS.
13 static void pcibios_fixup_peer_bridges(void)
17 if (pcibios_last_bus <= 0 || pcibios_last_bus > 0xff)
19 DBG("PCI: Peer bridge fixup\n");
21 for (n=0; n <= pcibios_last_bus; n++)
22 pcibios_scan_specific_bus(n);
25 int __init pci_legacy_init(void)
28 printk("PCI: System does not support PCI\n");
32 printk("PCI: Probing PCI hardware\n");
37 void pcibios_scan_specific_bus(int busn)
43 if (pci_find_bus(0, busn))
46 node = get_mp_bus_to_node(busn);
47 for (devfn = 0; devfn < 256; devfn += 8) {
48 if (!raw_pci_read(0, busn, devfn, PCI_VENDOR_ID, 2, &l) &&
49 l != 0x0000 && l != 0xffff) {
50 DBG("Found device at %02x:%02x [%04x]\n", busn, devfn, l);
51 printk(KERN_INFO "PCI: Discovered peer bus %02x\n", busn);
52 pci_scan_bus_on_node(busn, &pci_root_ops, node);
57 EXPORT_SYMBOL_GPL(pcibios_scan_specific_bus);
59 int __init pci_subsys_init(void)
62 * The init function returns an non zero value when
63 * pci_legacy_init should be invoked.
65 if (x86_init.pci.init())
68 pcibios_fixup_peer_bridges();
69 x86_init.pci.init_irq();
74 subsys_initcall(pci_subsys_init);