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 <linux/acpi.h>
   9
  10 #include <asm/pci-direct.h>
  11 #include <asm/acpi.h>
  12 #include <asm/apic.h>
  13
  14 #ifdef CONFIG_ACPI
  15
  16 static int nvidia_hpet_detected __initdata;
  17
  18 static int __init nvidia_hpet_check(unsigned long phys, unsigned long size)
  19 {
  20         nvidia_hpet_detected = 1;
  21         return 0;
  22 }
  23 #endif
  24
  25 static int __init check_bridge(int vendor, int device)
  26 {
  27 #ifdef CONFIG_ACPI
  28         /* According to Nvidia all timer overrides are bogus unless HPET
  29            is enabled. */
  30         if (vendor == PCI_VENDOR_ID_NVIDIA) {
  31                 nvidia_hpet_detected = 0;
  32                 acpi_table_parse(ACPI_HPET, nvidia_hpet_check);
  33                 if (nvidia_hpet_detected == 0) {
  34                         acpi_skip_timer_override = 1;
  35                 }
  36         }
  37 #endif
  38         if (vendor == PCI_VENDOR_ID_ATI && timer_over_8254 == 1) {
  39                 timer_over_8254 = 0;
  40                 printk(KERN_INFO "ATI board detected. Disabling timer routing "
  41                                 "over 8254.\n");
  42         }
  43         return 0;
  44 }
  45
  46 void __init check_acpi_pci(void)
  47 {
  48         int num, slot, func;
  49
  50         /* Assume the machine supports type 1. If not it will
  51            always read ffffffff and should not have any side effect.
  52            Actually a few buggy systems can machine check. Allow the user
  53            to disable it by command line option at least -AK */
  54         if (!early_pci_allowed())
  55                 return;
  56
  57         /* Poor man's PCI discovery */
  58         for (num = 0; num < 32; num++) {
  59                 for (slot = 0; slot < 32; slot++) {
  60                         for (func = 0; func < 8; func++) {
  61                                 u32 class;
  62                                 u32 vendor;
  63                                 class = read_pci_config(num, slot, func,
  64                                                         PCI_CLASS_REVISION);
  65                                 if (class == 0xffffffff)
  66                                         break;
  67
  68                                 if ((class >> 16) != PCI_CLASS_BRIDGE_PCI)
  69                                         continue;
  70
  71                                 vendor = read_pci_config(num, slot, func,
  72                                                          PCI_VENDOR_ID);
  73
  74                                 if (check_bridge(vendor & 0xffff, vendor >> 16))
  75                                         return;
  76                         }
  77
  78                 }
  79         }
  80 }