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