arch/i386/kernel/acpi/earlyquirk.c

   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 #include <asm/apic.h>
  11
  12 static int __init check_bridge(int vendor, int device)
  13 {
  14 #ifdef CONFIG_ACPI
  15         /* According to Nvidia all timer overrides are bogus. Just ignore
  16            them all. */
  17         if (vendor == PCI_VENDOR_ID_NVIDIA) {
  18                 acpi_skip_timer_override = 1;
  19         }
  20 #endif
  21         if (vendor == PCI_VENDOR_ID_ATI && timer_over_8254 == 1) {
  22                 timer_over_8254 = 0;
  23                 printk(KERN_INFO "ATI board detected. Disabling timer routing "
  24                                 "over 8254.\n");
  25         }
  26         return 0;
  27 }
  28
  29 void __init check_acpi_pci(void)
  30 {
  31         int num, slot, func;
  32
  33         /* Assume the machine supports type 1. If not it will
  34            always read ffffffff and should not have any side effect. */
  35
  36         /* Poor man's PCI discovery */
  37         for (num = 0; num < 32; num++) {
  38                 for (slot = 0; slot < 32; slot++) {
  39                         for (func = 0; func < 8; func++) {
  40                                 u32 class;
  41                                 u32 vendor;
  42                                 class = read_pci_config(num, slot, func,
  43                                                         PCI_CLASS_REVISION);
  44                                 if (class == 0xffffffff)
  45                                         break;
  46
  47                                 if ((class >> 16) != PCI_CLASS_BRIDGE_PCI)
  48                                         continue;
  49
  50                                 vendor = read_pci_config(num, slot, func,
  51                                                          PCI_VENDOR_ID);
  52
  53                                 if (check_bridge(vendor & 0xffff, vendor >> 16))
  54                                         return;
  55                         }
  56
  57                 }
  58         }
  59 }