/* * legacy.c - traditional, old school PCI bus probing */ #include <linux/init.h> #include <linux/export.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; if (pcibios_last_bus <= 0 || pcibios_last_bus > 0xff) return; DBG("PCI: Peer bridge fixup\n"); for (n=0; n <= pcibios_last_bus; n++) pcibios_scan_specific_bus(n); } 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); return 0; } void __devinit pcibios_scan_specific_bus(int busn) { int devfn; long node; u32 l; if (pci_find_bus(0, busn)) return; node = get_mp_bus_to_node(busn); for (devfn = 0; devfn < 256; devfn += 8) { if (!raw_pci_read(0, busn, devfn, PCI_VENDOR_ID, 2, &l) && l != 0x0000 && l != 0xffff) { DBG("Found device at %02x:%02x [%04x]\n", busn, devfn, l); printk(KERN_INFO "PCI: Discovered peer bus %02x\n", busn); pci_scan_bus_on_node(busn, &pci_root_ops, node); return; } } } EXPORT_SYMBOL_GPL(pcibios_scan_specific_bus); 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(); x86_init.pci.init_irq(); pcibios_init(); return 0; } subsys_initcall(pci_subsys_init);