| /* |
| * Do early PCI probing for bug detection when the main PCI subsystem is |
| * not up yet. |
| */ |
| #include <linux/init.h> |
| #include <linux/kernel.h> |
| #include <linux/pci.h> |
| #include <asm/pci-direct.h> |
| #include <asm/acpi.h> |
| |
| static int __init check_bridge(int vendor, int device) |
| { |
| /* According to Nvidia all timer overrides are bogus. Just ignore |
| them all. */ |
| if (vendor == PCI_VENDOR_ID_NVIDIA) { |
| acpi_skip_timer_override = 1; |
| } |
| return 0; |
| } |
| |
| void __init check_acpi_pci(void) |
| { |
| int num, slot, func; |
| |
| /* Assume the machine supports type 1. If not it will |
| always read ffffffff and should not have any side effect. */ |
| |
| /* Poor man's PCI discovery */ |
| for (num = 0; num < 32; num++) { |
| for (slot = 0; slot < 32; slot++) { |
| for (func = 0; func < 8; func++) { |
| u32 class; |
| u32 vendor; |
| class = read_pci_config(num, slot, func, |
| PCI_CLASS_REVISION); |
| if (class == 0xffffffff) |
| break; |
| |
| if ((class >> 16) != PCI_CLASS_BRIDGE_PCI) |
| continue; |
| |
| vendor = read_pci_config(num, slot, func, |
| PCI_VENDOR_ID); |
| |
| if (check_bridge(vendor & 0xffff, vendor >> 16)) |
| return; |
| } |
| |
| } |
| } |
| } |