[PATCH] x86/PCI: Ignore CPU non-addressable _CRS reserved memoryresources

From: Gary Hade
Date: Mon Nov 14 2011 - 18:42:27 EST



From: Gary Hade <garyhade@xxxxxxxxxx>

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@xxxxxxxxxx>
Reviewed-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Jesse Barnes <jbarnes@xxxxxxxxxxxxxxxx>
Cc: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Cc: Thomas Renninger <trenn@xxxxxxxxxx>
Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: stable@xxxxxxxxxx
---

arch/x86/pci/acpi.c | 18 ++++++++++++++++--
1 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index 404f21a..3557af7 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -149,7 +149,7 @@ 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))
@@ -165,7 +165,21 @@ 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;

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