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

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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>
This commit is contained in:
Andi Kleen 2006-02-26 04:18:31 +01:00 committed by Linus Torvalds
parent 5342fba541
commit 13a229abc2
3 changed files with 22 additions and 4 deletions
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3
arch/i386/kernel/acpi/boot.c
View File

@ -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

9
arch/x86_64/kernel/apic.c
View File

@ -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++) {

14
include/asm-x86_64/acpi.h
View File

@ -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*/