[PATCH] x86_64: Only do the clustered systems have unsynchronized TSC assumption on IBM systems

Big Unisys systems have multiple clusters too, but they have an
synchronized TSC.

I'm using the SMBIOS to check for vendor == IBM.

Cc: Chris McDermott <lcm@us.ibm.com>
Cc: "Protasevich, Natalie" <Natalie.Protasevich@unisys.com>

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 14 insertions, 0 deletions

diff --git a/include/asm-x86_64/acpi.h b/include/asm-x86_64/acpi.h
index aa1c7b2e438c..e2b9923189a0 100644
--- a/include/asm-x86_64/acpi.h
+++ b/include/asm-x86_64/acpi.h
@@ -164,6 +164,20 @@ extern u8 x86_acpiid_to_apicid[];
 
 extern int acpi_skip_timer_override;
 
+extern int unsync_tsc_on_multicluster;
+
+static inline int acpi_madt_oem_check(char *oem, char *productid) 
+{ 
+        /* Copied from i386. Probably has too many entries. */
+        if (!strncmp(oem, "IBM ENSW", 8) && 
+                (!strncmp(productid, "VIGIL SMP", 9) 
+                        || !strncmp(productid, "EXA", 3)
+                        || !strncmp(productid, "RUTHLESS SMP", 12))) {
+                unsync_tsc_on_multicluster = 1;
+        }
+        return 0;
+}
+
 #endif /*__KERNEL__*/
 
 #endif /*_ASM_ACPI_H*/