From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/x86/pci/legacy.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) create mode 100644 arch/x86/pci/legacy.c (limited to 'arch/x86/pci/legacy.c') diff --git a/arch/x86/pci/legacy.c b/arch/x86/pci/legacy.c new file mode 100644 index 000000000..5b662c0fa --- /dev/null +++ b/arch/x86/pci/legacy.c @@ -0,0 +1,72 @@ +/* + * legacy.c - traditional, old school PCI bus probing + */ +#include +#include +#include +#include + +/* + * 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 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"); + pcibios_scan_root(0); + return 0; +} + +void pcibios_scan_specific_bus(int busn) +{ + int devfn; + u32 l; + + if (pci_find_bus(0, busn)) + return; + + 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); + pcibios_scan_root(busn); + 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); -- cgit v1.2.3-54-g00ecf