From: Thomas Gleixner <tglx@linutronix.de>

PIT clock events work already and the PIT handling is the same for i386 and
x86_64.  x86_64 does not support PIT as a clock source, so disable the PIT
clocksource for x86_64.

Use the i386 i8253.h include file for x86_64 as well to share the
exports and the PIT constants.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 arch/x86_64/kernel/time.c  |    4 ----
 include/asm-x86_64/i8253.h |    8 ++------
 2 files changed, 2 insertions(+), 10 deletions(-)

diff -puN arch/x86_64/kernel/time.c~x86_64-use-i386-i8253-h arch/x86_64/kernel/time.c
--- a/arch/x86_64/kernel/time.c~x86_64-use-i386-i8253-h
+++ a/arch/x86_64/kernel/time.c
@@ -32,7 +32,6 @@
 #include <acpi/achware.h>	/* for PM timer frequency */
 #include <acpi/acpi_bus.h>
 #endif
-#include <asm/8253pit.h>
 #include <asm/i8253.h>
 #include <asm/pgtable.h>
 #include <asm/vsyscall.h>
@@ -292,9 +291,6 @@ static unsigned int __init tsc_calibrate
 	return pmc_now * tsc_khz / (tsc_now - tsc_start);
 }
 
-#define PIT_MODE 0x43
-#define PIT_CH0  0x40
-
 static void __pit_init(int val, u8 mode)
 {
 	unsigned long flags;
diff -puN include/asm-x86_64/i8253.h~x86_64-use-i386-i8253-h include/asm-x86_64/i8253.h
--- a/include/asm-x86_64/i8253.h~x86_64-use-i386-i8253-h
+++ a/include/asm-x86_64/i8253.h
@@ -1,6 +1,2 @@
-#ifndef __ASM_I8253_H__
-#define __ASM_I8253_H__
-
-extern spinlock_t i8253_lock;
-
-#endif	/* __ASM_I8253_H__ */
+#include <asm-i386/i8253.h>
+#include <asm/8253pit.h>
_