x86/PCI: Ignore CPU non-addressable _CRS reserved memory resources
Gary Hade [Mon, 14 Nov 2011 23:42:16 +0000 (15:42 -0800)]
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>

arch/x86/pci/acpi.c

index e662cee..425500b 100644 (file)
@@ -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;