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authorAndi Kleen <ak@suse.de>2006-02-26 04:18:31 +0100
committerLinus Torvalds <torvalds@g5.osdl.org>2006-02-26 09:53:30 -0800
commit13a229abc25640813f1480c0478dfc6bdbc1c19e (patch)
treebdb9da6ba327bd4f6ee64aa3ca1548670be395f2
parent5342fba5412cead88b61ead07168615dbeba1ee3 (diff)
[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>
-rw-r--r--arch/i386/kernel/acpi/boot.c3
-rw-r--r--arch/x86_64/kernel/apic.c9
-rw-r--r--include/asm-x86_64/acpi.h14
3 files changed, 22 insertions, 4 deletions
diff --git a/arch/i386/kernel/acpi/boot.c b/arch/i386/kernel/acpi/boot.c
index 79577f0ace98..8309a7b2cd63 100644
--- a/arch/i386/kernel/acpi/boot.c
+++ b/arch/i386/kernel/acpi/boot.c
@@ -44,9 +44,6 @@ extern void __init clustered_apic_check(void);
extern int gsi_irq_sharing(int gsi);
#include <asm/proto.h>
-static inline int acpi_madt_oem_check(char *oem_id, char *oem_table_id) { return 0; }
-
-
#else /* X86 */
#ifdef CONFIG_X86_LOCAL_APIC
diff --git a/arch/x86_64/kernel/apic.c b/arch/x86_64/kernel/apic.c
index e5b14c57eaa0..d70605eda333 100644
--- a/arch/x86_64/kernel/apic.c
+++ b/arch/x86_64/kernel/apic.c
@@ -962,12 +962,14 @@ void smp_apic_timer_interrupt(struct pt_regs *regs)
irq_exit();
}
+int __initdata unsync_tsc_on_multicluster;
+
/*
* oem_force_hpet_timer -- force HPET mode for some boxes.
*
* Thus far, the major user of this is IBM's Summit2 series:
*
- * Clustered boxes may have unsynced TSC problems if they are
+ * Some clustered boxes may have unsynced TSC problems if they are
* multi-chassis. Use available data to take a good guess.
* If in doubt, go HPET.
*/
@@ -977,6 +979,11 @@ __cpuinit int oem_force_hpet_timer(void)
unsigned id;
DECLARE_BITMAP(clustermap, NUM_APIC_CLUSTERS);
+ /* Only do this check on IBM machines - big Unisys systems
+ use multiple clusters too, but have synchronized TSC */
+ if (!unsync_tsc_on_multicluster)
+ return 0;
+
bitmap_zero(clustermap, NUM_APIC_CLUSTERS);
for (i = 0; i < NR_CPUS; i++) {
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*/