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

PATCH Applied Gary Hade 2 participants 2 messages Nov 14, 2011 – Dec 5, 2011

Subsystems (3)
x86 ACPI PCI
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Gary Hade

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PATCH 1/1 x86/PCI: Ignore CPU non-addressable _CRS reserved memory resources

From: Gary Hade <[email protected]>

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 <[email protected]>
Reviewed-by Bjorn Helgaas <[email protected]>
Cc Jesse Barnes <[email protected]>
Cc Bjorn Helgaas <[email protected]>
Cc Thomas Renninger <[email protected]>
Cc [email protected]
Cc [email protected]

---

 arch/x86/pci/acpi.c |   18 ++++++++++++++++--
 1 files changed, 16 insertions(+), 2 deletions(-)
arch/x86/pci/acpi.c +16 -2
index 404f21a..3557af7 100644
@@ -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;
Applied
#1 lore raw
Quoted 13 lines · On Mon, 14 Nov 2011 15:42:16 -0800 Gary Hade <[email protected]> wrote:

From: Gary Hade <[email protected]>

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.

Quoted 8 lines
Signed-off-by Gary Hade <[email protected]>
Reviewed-by Bjorn Helgaas <[email protected]>
Cc Jesse Barnes <[email protected]>
Cc Bjorn Helgaas <[email protected]>
Cc Thomas Renninger <[email protected]>
Cc [email protected]
Cc [email protected]

---

Applied to linux-next (don't want to send something this fundamental to Linus at this late stage). It can land in stable if it turns out ok in -rc1.

Thanks,

Signature · 1 line
Jesse Barnes, Intel Open Source Technology Center