linux-stable/arch/x86/pci/legacy.c
Bjorn Helgaas 46fbade05c x86/PCI: use pci_scan_bus() instead of pci_scan_bus_parented()
This doesn't change any functionality, but it makes a subsequent patch
slightly simpler.

pci_scan_bus(NULL, ...) and pci_scan_bus_parented() are identical except
that pci_scan_bus() also calls pci_bus_add_devices():

  pci_scan_bus_parented
    pci_create_bus
    pci_scan_child_bus

  pci_scan_bus
    pci_create_bus
    pci_scan_child_bus
    pci_bus_add_devices

All callers of pcibios_scan_root() call pci_bus_add_devices() explicitly,
and we don't pass a parent device, so we might as well use pci_scan_bus().

Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
2012-01-06 12:11:13 -08:00

74 lines
1.6 KiB
C

/*
* 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);