arch/x86/kernel/acpi/earlyquirk_32.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 __init nvidia_hpet_check(struct acpi_table_header *header)
  17 {
  18         return 0;
  19 }
  20 #endif
  21
  22 static int __init check_bridge(int vendor, int device)
  23 {
  24 #ifdef CONFIG_ACPI
  25         static int warned;
  26         /* According to Nvidia all timer overrides are bogus unless HPET
  27            is enabled. */
  28         if (!acpi_use_timer_override && vendor == PCI_VENDOR_ID_NVIDIA) {
  29                 if (!warned && acpi_table_parse(ACPI_SIG_HPET,
  30                                                 nvidia_hpet_check)) {
  31                         warned = 1;
  32                         acpi_skip_timer_override = 1;
  33                           printk(KERN_INFO "Nvidia board "
  34                        "detected. Ignoring ACPI "
  35                        "timer override.\n");
  36                 printk(KERN_INFO "If you got timer trouble "
  37                                  "try acpi_use_timer_override\n");
  38
  39                 }
  40         }
  41 #endif
  42         if (vendor == PCI_VENDOR_ID_ATI && timer_over_8254 == 1) {
  43                 timer_over_8254 = 0;
  44                 printk(KERN_INFO "ATI board detected. Disabling timer routing "
  45                                 "over 8254.\n");
  46         }
  47         return 0;
  48 }
  49
  50 void __init check_acpi_pci(void)
  51 {
  52         int num, slot, func;
  53
  54         /* Assume the machine supports type 1. If not it will
  55            always read ffffffff and should not have any side effect.
  56            Actually a few buggy systems can machine check. Allow the user
  57            to disable it by command line option at least -AK */
  58         if (!early_pci_allowed())
  59                 return;
  60
  61         /* Poor man's PCI discovery */
  62         for (num = 0; num < 32; num++) {
  63                 for (slot = 0; slot < 32; slot++) {
  64                         for (func = 0; func < 8; func++) {
  65                                 u32 class;
  66                                 u32 vendor;
  67                                 class = read_pci_config(num, slot, func,
  68                                                         PCI_CLASS_REVISION);
  69                                 if (class == 0xffffffff)
  70                                         break;
  71
  72                                 if ((class >> 16) != PCI_CLASS_BRIDGE_PCI)
  73                                         continue;
  74
  75                                 vendor = read_pci_config(num, slot, func,
  76                                                          PCI_VENDOR_ID);
  77
  78                                 if (check_bridge(vendor & 0xffff, vendor >> 16))
  79                                         return;
  80                         }
  81
  82                 }
  83         }
  84 }