1 /*
2 * Do early PCI probing for bug detection when the main PCI subsystem is
3 * not up yet.
4 */
5 #include <linux/init.h>
6 #include <linux/kernel.h>
7 #include <linux/pci.h>
8 #include <asm/pci-direct.h>
9 #include <asm/acpi.h>
10
11 #ifdef CONFIG_ACPI_BOOT
check_bridge(int vendor,int device)12 static int __init check_bridge(int vendor, int device)
13 {
14 /* According to Nvidia all timer overrides are bogus. Just ignore
15 them all. */
16 if (vendor == PCI_VENDOR_ID_NVIDIA) {
17 acpi_skip_timer_override = 1;
18 }
19 return 0;
20 }
21
check_acpi_pci(void)22 void __init check_acpi_pci(void)
23 {
24 int num,slot,func;
25
26 /* Assume the machine supports type 1. If not it will
27 always read ffffffff and should not have any side effect. */
28
29 /* Poor man's PCI discovery */
30 for (num = 0; num < 32; num++) {
31 for (slot = 0; slot < 32; slot++) {
32 for (func = 0; func < 8; func++) {
33 u32 class;
34 u32 vendor;
35 class = read_pci_config(num,slot,func,
36 PCI_CLASS_REVISION);
37 if (class == 0xffffffff)
38 break;
39
40 if ((class >> 16) != PCI_CLASS_BRIDGE_PCI)
41 continue;
42
43 vendor = read_pci_config(num, slot, func,
44 PCI_VENDOR_ID);
45
46 if (check_bridge(vendor&0xffff, vendor >> 16))
47 return;
48 }
49
50 }
51 }
52 }
53 #endif /* CONFIG_ACPI */
54