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x86/PCI: use host bridge _CRS info by default on 2008 and newer machines

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The main benefit of using ACPI host bridge window information is that
we can do better resource allocation in systems with multiple host bridges,
e.g., http://bugzilla.kernel.org/show_bug.cgi?id=14183

Sometimes we need _CRS information even if we only have one host bridge,
e.g., https://bugs.launchpad.net/ubuntu/+source/linux/+bug/341681

Most of these systems are relatively new, so this patch turns on
"pci=use_crs" only on machines with a BIOS date of 2008 or newer.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
This commit is contained in:
Bjorn Helgaas
2010-02-23 10:24:41 -07:00
committed by Jesse Barnes
parent 2fe2abf896
commit 7bc5e3f2be
7 changed files with 60 additions and 8 deletions
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53
arch/x86/pci/acpi.c
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@@ -15,6 +15,51 @@ struct pci_root_info {
int busnum;
};
static bool pci_use_crs = true;
static int __init set_use_crs(const struct dmi_system_id *id)
{
pci_use_crs = true;
return 0;
}
static const struct dmi_system_id pci_use_crs_table[] __initconst = {
/* http://bugzilla.kernel.org/show_bug.cgi?id=14183 */
{
.callback = set_use_crs,
.ident = "IBM System x3800",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
DMI_MATCH(DMI_PRODUCT_NAME, "x3800"),
},
},
{}
};
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_use_crs_table);
/*
* 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 acpi_status
resource_to_addr(struct acpi_resource *resource,
struct acpi_resource_address64 *addr)
@@ -106,7 +151,7 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
res->child = NULL;
align_resource(info->bridge, res);
if (!(pci_probe & PCI_USE__CRS)) {
if (!pci_use_crs) {
dev_printk(KERN_DEBUG, &info->bridge->dev,
"host bridge window %pR (ignored)\n", res);
return AE_OK;
@@ -137,12 +182,8 @@ get_current_resources(struct acpi_device *device, int busnum,
struct pci_root_info info;
size_t size;
if (pci_probe & PCI_USE__CRS)
if (pci_use_crs)
pci_bus_remove_resources(bus);
else
dev_info(&device->dev,
"ignoring host bridge windows from ACPI; "
"boot with \"pci=use_crs\" to use them\n");
info.bridge = device;
info.bus = bus;