arch/x86/kernel/early-quirks.c

   1 /* Various workarounds for chipset bugs.
   2    This code runs very early and can't use the regular PCI subsystem
   3    The entries are keyed to PCI bridges which usually identify chipsets
   4    uniquely.
   5    This is only for whole classes of chipsets with specific problems which
   6    need early invasive action (e.g. before the timers are initialized).
   7    Most PCI device specific workarounds can be done later and should be
   8    in standard PCI quirks
   9    Mainboard specific bugs should be handled by DMI entries.
  10    CPU specific bugs in setup.c */
  11
  12 #include <linux/pci.h>
  13 #include <linux/acpi.h>
  14 #include <linux/pci_ids.h>
  15 #include <asm/pci-direct.h>
  16 #include <asm/dma.h>
  17 #include <asm/io_apic.h>
  18 #include <asm/apic.h>
  19 #include <asm/iommu.h>
  20
  21 static void __init fix_hypertransport_config(int num, int slot, int func)
  22 {
  23         u32 htcfg;
  24         /*
  25          * we found a hypertransport bus
  26          * make sure that we are broadcasting
  27          * interrupts to all cpus on the ht bus
  28          * if we're using extended apic ids
  29          */
  30         htcfg = read_pci_config(num, slot, func, 0x68);
  31         if (htcfg & (1 << 18)) {
  32                 printk(KERN_INFO "Detected use of extended apic ids "
  33                                  "on hypertransport bus\n");
  34                 if ((htcfg & (1 << 17)) == 0) {
  35                         printk(KERN_INFO "Enabling hypertransport extended "
  36                                          "apic interrupt broadcast\n");
  37                         printk(KERN_INFO "Note this is a bios bug, "
  38                                          "please contact your hw vendor\n");
  39                         htcfg |= (1 << 17);
  40                         write_pci_config(num, slot, func, 0x68, htcfg);
  41                 }
  42         }
  43
  44
  45 }
  46
  47 static void __init via_bugs(int  num, int slot, int func)
  48 {
  49 #ifdef CONFIG_GART_IOMMU
  50         if ((max_pfn > MAX_DMA32_PFN ||  force_iommu) &&
  51             !gart_iommu_aperture_allowed) {
  52                 printk(KERN_INFO
  53                        "Looks like a VIA chipset. Disabling IOMMU."
  54                        " Override with iommu=allowed\n");
  55                 gart_iommu_aperture_disabled = 1;
  56         }
  57 #endif
  58 }
  59
  60 #ifdef CONFIG_ACPI
  61 #ifdef CONFIG_X86_IO_APIC
  62
  63 static int __init nvidia_hpet_check(struct acpi_table_header *header)
  64 {
  65         return 0;
  66 }
  67 #endif /* CONFIG_X86_IO_APIC */
  68 #endif /* CONFIG_ACPI */
  69
  70 static void __init nvidia_bugs(int num, int slot, int func)
  71 {
  72 #ifdef CONFIG_ACPI
  73 #ifdef CONFIG_X86_IO_APIC
  74         /*
  75          * All timer overrides on Nvidia are
  76          * wrong unless HPET is enabled.
  77          * Unfortunately that's not true on many Asus boards.
  78          * We don't know yet how to detect this automatically, but
  79          * at least allow a command line override.
  80          */
  81         if (acpi_use_timer_override)
  82                 return;
  83
  84         if (acpi_table_parse(ACPI_SIG_HPET, nvidia_hpet_check)) {
  85                 acpi_skip_timer_override = 1;
  86                 printk(KERN_INFO "Nvidia board "
  87                        "detected. Ignoring ACPI "
  88                        "timer override.\n");
  89                 printk(KERN_INFO "If you got timer trouble "
  90                         "try acpi_use_timer_override\n");
  91         }
  92 #endif
  93 #endif
  94         /* RED-PEN skip them on mptables too? */
  95
  96 }
  97
  98 #define QFLAG_APPLY_ONCE        0x1
  99 #define QFLAG_APPLIED           0x2
 100 #define QFLAG_DONE              (QFLAG_APPLY_ONCE|QFLAG_APPLIED)
 101 struct chipset {
 102         u32 vendor;
 103         u32 device;
 104         u32 class;
 105         u32 class_mask;
 106         u32 flags;
 107         void (*f)(int num, int slot, int func);
 108 };
 109
 110 static struct chipset early_qrk[] __initdata = {
 111         { PCI_VENDOR_ID_NVIDIA, PCI_ANY_ID,
 112           PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, QFLAG_APPLY_ONCE, nvidia_bugs },
 113         { PCI_VENDOR_ID_VIA, PCI_ANY_ID,
 114           PCI_CLASS_BRIDGE_PCI, PCI_ANY_ID, QFLAG_APPLY_ONCE, via_bugs },
 115         { PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB,
 116           PCI_CLASS_BRIDGE_HOST, PCI_ANY_ID, 0, fix_hypertransport_config },
 117         {}
 118 };
 119
 120 /**
 121  * check_dev_quirk - apply early quirks to a given PCI device
 122  * @num: bus number
 123  * @slot: slot number
 124  * @func: PCI function
 125  *
 126  * Check the vendor & device ID against the early quirks table.
 127  *
 128  * If the device is single function, let early_quirks() know so we don't
 129  * poke at this device again.
 130  */
 131 static int __init check_dev_quirk(int num, int slot, int func)
 132 {
 133         u16 class;
 134         u16 vendor;
 135         u16 device;
 136         u8 type;
 137         int i;
 138
 139         class = read_pci_config_16(num, slot, func, PCI_CLASS_DEVICE);
 140
 141         if (class == 0xffff)
 142                 return -1; /* no class, treat as single function */
 143
 144         vendor = read_pci_config_16(num, slot, func, PCI_VENDOR_ID);
 145
 146         device = read_pci_config_16(num, slot, func, PCI_DEVICE_ID);
 147
 148         for (i = 0; early_qrk[i].f != NULL; i++) {
 149                 if (((early_qrk[i].vendor == PCI_ANY_ID) ||
 150                         (early_qrk[i].vendor == vendor)) &&
 151                         ((early_qrk[i].device == PCI_ANY_ID) ||
 152                         (early_qrk[i].device == device)) &&
 153                         (!((early_qrk[i].class ^ class) &
 154                             early_qrk[i].class_mask))) {
 155                                 if ((early_qrk[i].flags &
 156                                      QFLAG_DONE) != QFLAG_DONE)
 157                                         early_qrk[i].f(num, slot, func);
 158                                 early_qrk[i].flags |= QFLAG_APPLIED;
 159                         }
 160         }
 161
 162         type = read_pci_config_byte(num, slot, func,
 163                                     PCI_HEADER_TYPE);
 164         if (!(type & 0x80))
 165                 return -1;
 166
 167         return 0;
 168 }
 169
 170 void __init early_quirks(void)
 171 {
 172         int num, slot, func;
 173
 174         if (!early_pci_allowed())
 175                 return;
 176
 177         /* Poor man's PCI discovery */
 178         for (num = 0; num < 32; num++)
 179                 for (slot = 0; slot < 32; slot++)
 180                         for (func = 0; func < 8; func++) {
 181                                 /* Only probe function 0 on single fn devices */
 182                                 if (check_dev_quirk(num, slot, func))
 183                                         break;
 184                         }
 185 }