/*
* Before we decide to use direct hardware access mechanisms, we try to do some
* trivial checks to ensure it at least _seems_ to be working -- we just test
* whether bus 00 contains a host bridge (this is similar to checking
* techniques used in XFree86, but ours should be more reliable since we
* attempt to make use of direct access hints provided by the PCI BIOS).
*
* This should be close to trivial, but it isn't, because there are buggy
* chipsets (yes, you guessed it, by Intel and Compaq) that have no class ID.
*/
static int __init pci_sanity_check(struct pci_raw_ops *o)
{
u32 x = 0;
int year, devfn;
if (pci_probe & PCI_NO_CHECKS)
return 1;
/* Assume Type 1 works for newer systems.
This handles machines that don't have anything on PCI Bus 0. */
dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL);
if (year >= 2001)
return 1;
for (devfn = 0; devfn < 0x100; devfn++) {
if (o->read(0, 0, devfn, PCI_CLASS_DEVICE, 2, &x))
continue;
if (x == PCI_CLASS_BRIDGE_HOST || x == PCI_CLASS_DISPLAY_VGA)
return 1;
if (o->read(0, 0, devfn, PCI_VENDOR_ID, 2, &x))
continue;
if (x == PCI_VENDOR_ID_INTEL || x == PCI_VENDOR_ID_COMPAQ)
return 1;
}
DBG(KERN_WARNING "PCI: Sanity check failed\n");
return 0;
}
void __init pci_acpi_crs_quirks(void)
{
int year;
if (dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) && year < 2008)
pci_use_crs = false;
dmi_check_system(pci_crs_quirks);
/*
* If the user specifies "pci=use_crs" or "pci=nocrs" explicitly, that
* takes precedence over anything we figured out above.
*/
if (pci_probe & PCI_ROOT_NO_CRS)
pci_use_crs = false;
else if (pci_probe & PCI_USE__CRS)
pci_use_crs = true;
printk(KERN_INFO "PCI: %s host bridge windows from ACPI; "
"if necessary, use \"pci=%s\" and report a bug\n",
pci_use_crs ? "Using" : "Ignoring",
pci_use_crs ? "nocrs" : "use_crs");
}
static int __init acpi_mcfg_check_entry(struct acpi_table_mcfg *mcfg,
struct acpi_mcfg_allocation *cfg)
{
int year;
if (cfg->address < 0xFFFFFFFF)
return 0;
if (!strcmp(mcfg->header.oem_id, "SGI") ||
!strcmp(mcfg->header.oem_id, "SGI2"))
return 0;
if (mcfg->header.revision >= 1 &&
dmi_get_date(DMI_BIOS_DATE, &year, NULL, NULL) &&
year >= 2010)
return 0;
printk(KERN_ERR "MCFG region for %04x:%02x-%02x at %#"PRIx64
" (above 4GB) ignored\n",
cfg->pci_segment, cfg->start_bus_number, cfg->end_bus_number,
cfg->address);
return -EINVAL;
}