Commit | Line | Data |
---|---|---|
1da177e4 LT |
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 | ||
16 | if (pcibios_last_bus <= 0 || pcibios_last_bus >= 0xff) | |
17 | return; | |
18 | DBG("PCI: Peer bridge fixup\n"); | |
19 | ||
20 | for (n=0; n <= pcibios_last_bus; n++) { | |
21 | u32 l; | |
22 | if (pci_find_bus(0, n)) | |
23 | continue; | |
24 | for (devfn = 0; devfn < 256; devfn += 8) { | |
25 | if (!raw_pci_ops->read(0, n, devfn, PCI_VENDOR_ID, 2, &l) && | |
26 | l != 0x0000 && l != 0xffff) { | |
27 | DBG("Found device at %02x:%02x [%04x]\n", n, devfn, l); | |
28 | printk(KERN_INFO "PCI: Discovered peer bus %02x\n", n); | |
29 | pci_scan_bus(n, &pci_root_ops, NULL); | |
30 | break; | |
31 | } | |
32 | } | |
33 | } | |
34 | } | |
35 | ||
36 | static int __init pci_legacy_init(void) | |
37 | { | |
38 | if (!raw_pci_ops) { | |
39 | printk("PCI: System does not support PCI\n"); | |
40 | return 0; | |
41 | } | |
42 | ||
43 | if (pcibios_scanned++) | |
44 | return 0; | |
45 | ||
46 | printk("PCI: Probing PCI hardware\n"); | |
47 | pci_root_bus = pcibios_scan_root(0); | |
48 | ||
49 | pcibios_fixup_peer_bridges(); | |
50 | ||
51 | return 0; | |
52 | } | |
53 | ||
54 | subsys_initcall(pci_legacy_init); |