x86/PCI: Ignore CPU non-addressable _CRS reserved memory resources

This assures that a _CRS reserved host bridge window or window region is
not used if it is not addressable by the CPU.  The new code either trims
the window to exclude the non-addressable portion or totally ignores the
window if the entire window is non-addressable.

The current code has been shown to be problematic with 32-bit non-PAE
kernels on systems where _CRS reserves resources above 4GB.

Signed-off-by: Gary Hade <garyhade@us.ibm.com>
Reviewed-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Thomas Renninger <trenn@novell.com>
Cc: linux-kernel@vger.kernel.org
Cc: stable@kernel.org
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

1 files changed, 16 insertions, 2 deletions

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index e662ceebd798..425500bb24e6 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -178,7 +178,7 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
 	struct acpi_resource_address64 addr;
 	acpi_status status;
 	unsigned long flags;
-	u64 start, end;
+	u64 start, orig_end, end;
 
 	status = resource_to_addr(acpi_res, &addr);
 	if (!ACPI_SUCCESS(status))
@@ -194,7 +194,21 @@ setup_resource(struct acpi_resource *acpi_res, void *data)
 		return AE_OK;
 
 	start = addr.minimum + addr.translation_offset;
-	end = addr.maximum + addr.translation_offset;
+	orig_end = end = addr.maximum + addr.translation_offset;
+
+	/* Exclude non-addressable range or non-addressable portion of range */
+	end = min(end, (u64)iomem_resource.end);
+	if (end <= start) {
+		dev_info(&info->bridge->dev,
+			"host bridge window [%#llx-%#llx] "
+			"(ignored, not CPU addressable)\n", start, orig_end);
+		return AE_OK;
+	} else if (orig_end != end) {
+		dev_info(&info->bridge->dev,
+			"host bridge window [%#llx-%#llx] "
+			"([%#llx-%#llx] ignored, not CPU addressable)\n", 
+			start, orig_end, end + 1, orig_end);
+	}
 
 	res = &info->res[info->res_num];
 	res->name = info->name;