x86/PCI: truncate _CRS windows with _LEN > _MAX - _MIN + 1
Yanko's GA-MA78GM-S2H (BIOS F11) reports the following resource in a PCI
host bridge _CRS:
[07] 32-Bit DWORD Address Space Resource
Min Relocatability : MinFixed
Max Relocatability : MaxFixed
Address Minimum : CFF00000 (_MIN)
Address Maximum : FEBFFFFF (_MAX)
Address Length : 3EE10000 (_LEN)
This is invalid per spec (ACPI 4.0, 6.4.3.5) because it's a fixed size,
fixed location descriptor, but _LEN != _MAX - _MIN + 1.
Based on https://bugzilla.kernel.org/show_bug.cgi?id=15480#c15, I think
Windows handles this by truncating the window so it fits between _MIN and
_MAX. I also verified this by modifying the SeaBIOS DSDT and booting
Windows 2008 R2 with qemu.
This patch makes Linux truncate the window, too, which fixes:
http://bugzilla.kernel.org/show_bug.cgi?id=15480
Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Tested-by: Yanko Kaneti <yaneti@declera.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 75ac3f8..e311602 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -123,7 +123,7 @@
acpi_status status;
unsigned long flags;
struct resource *root, *conflict;
- u64 start, end;
+ u64 start, end, max_len;
status = resource_to_addr(acpi_res, &addr);
if (!ACPI_SUCCESS(status))
@@ -140,6 +140,17 @@
} else
return AE_OK;
+ max_len = addr.maximum - addr.minimum + 1;
+ if (addr.address_length > max_len) {
+ dev_printk(KERN_DEBUG, &info->bridge->dev,
+ "host bridge window length %#llx doesn't fit in "
+ "%#llx-%#llx, trimming\n",
+ (unsigned long long) addr.address_length,
+ (unsigned long long) addr.minimum,
+ (unsigned long long) addr.maximum);
+ addr.address_length = max_len;
+ }
+
start = addr.minimum + addr.translation_offset;
end = start + addr.address_length - 1;