ACPI_NUMA: fix HP IA64 simulator issue with extended memory domain

ACPI 3.0 incorporated the SRAT spec, upping the table version to 2,
and extending the size of the proximity domain from 1-byte to 4-bytes.
This extension was into a reserved field that firmware should
set to 0, but the HP simulator had non-zero values there
resulting in unexpected huge numbers.

So mask the domain down to 8-bits for now.
A more general fix will be to check the table version
supplied by firmware and get paranoid about reserved fields.

Signed-off-by: Alexey Starikovskiy <alexey.y.starikovskiy@linux.intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
index 989ffc3f7ce3..a99b0cc92881 100644
--- a/arch/ia64/kernel/acpi.c
+++ b/arch/ia64/kernel/acpi.c
@@ -422,8 +422,8 @@ static int get_memory_proximity_domain(struct acpi_srat_mem_affinity *ma)
         int pxm;
 
         pxm = ma->proximity_domain;
-        if (ia64_platform_is("sn2"))
-                pxm += ma->reserved << 8;
+        if (!ia64_platform_is("sn2"))
+                pxm &= 0xff;
 
         return pxm;
 }