1 /* 2 * legacy.c - traditional, old school PCI bus probing 3 */ 4 #include <linux/init.h> 5 #include <linux/pci.h> 6 #include "pci.h" 7 8 /* 9 * Discover remaining PCI buses in case there are peer host bridges. 10 * We use the number of last PCI bus provided by the PCI BIOS. 11 */ 12 static void __devinit pcibios_fixup_peer_bridges(void) 13 { 14 int n, devfn; 15 long node; 16 17 if (pcibios_last_bus <= 0 || pcibios_last_bus >= 0xff) 18 return; 19 DBG("PCI: Peer bridge fixup\n"); 20 21 for (n=0; n <= pcibios_last_bus; n++) { 22 u32 l; 23 if (pci_find_bus(0, n)) 24 continue; 25 node = get_mp_bus_to_node(n); 26 for (devfn = 0; devfn < 256; devfn += 8) { 27 if (!raw_pci_read(0, n, devfn, PCI_VENDOR_ID, 2, &l) && 28 l != 0x0000 && l != 0xffff) { 29 DBG("Found device at %02x:%02x [%04x]\n", n, devfn, l); 30 printk(KERN_INFO "PCI: Discovered peer bus %02x\n", n); 31 pci_scan_bus_on_node(n, &pci_root_ops, node); 32 break; 33 } 34 } 35 } 36 } 37 38 static int __init pci_legacy_init(void) 39 { 40 if (!raw_pci_ops) { 41 printk("PCI: System does not support PCI\n"); 42 return 0; 43 } 44 45 if (pcibios_scanned++) 46 return 0; 47 48 printk("PCI: Probing PCI hardware\n"); 49 pci_root_bus = pcibios_scan_root(0); 50 if (pci_root_bus) 51 pci_bus_add_devices(pci_root_bus); 52 53 pcibios_fixup_peer_bridges(); 54 55 return 0; 56 } 57 58 int __init pci_subsys_init(void) 59 { 60 #ifdef CONFIG_X86_NUMAQ 61 pci_numaq_init(); 62 #endif 63 #ifdef CONFIG_ACPI 64 pci_acpi_init(); 65 #endif 66 #ifdef CONFIG_X86_VISWS 67 pci_visws_init(); 68 #endif 69 pci_legacy_init(); 70 pcibios_irq_init(); 71 pcibios_init(); 72 73 return 0; 74 } 75 subsys_initcall(pci_subsys_init); 76