[patch-mm 17/33] i386: prepare sharing the PIT code

From: Thomas Gleixner
Date: Sun Jul 15 2007 - 12:12:27 EST


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.

Prepare i8253.h to be shared with x8664

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>

---
arch/i386/kernel/i8253.c | 3 +++
include/asm-i386/i8253.h | 6 ++++--
2 files changed, 7 insertions(+), 2 deletions(-)

Index: linux-2.6.22-rc6-mm/arch/i386/kernel/i8253.c
===================================================================
--- linux-2.6.22-rc6-mm.orig/arch/i386/kernel/i8253.c 2007-07-15 17:26:45.000000000 +0200
+++ linux-2.6.22-rc6-mm/arch/i386/kernel/i8253.c 2007-07-15 17:39:21.000000000 +0200
@@ -120,6 +120,7 @@ void __init setup_pit_timer(void)
global_clock_event = &pit_clockevent;
}

+#ifndef CONFIG_X86_64
/*
* Since the PIT overflows every tick, its not very useful
* to just read by itself. So use jiffies to emulate a free
@@ -204,3 +205,5 @@ static int __init init_pit_clocksource(v
return clocksource_register(&clocksource_pit);
}
arch_initcall(init_pit_clocksource);
+
+#endif
Index: linux-2.6.22-rc6-mm/include/asm-i386/i8253.h
===================================================================
--- linux-2.6.22-rc6-mm.orig/include/asm-i386/i8253.h 2007-07-15 17:26:45.000000000 +0200
+++ linux-2.6.22-rc6-mm/include/asm-i386/i8253.h 2007-07-15 17:48:50.000000000 +0200
@@ -1,8 +1,6 @@
#ifndef __ASM_I8253_H__
#define __ASM_I8253_H__

-#include <linux/clockchips.h>
-
/* i8253A PIT registers */
#define PIT_MODE 0x43
#define PIT_CH0 0x40
@@ -10,8 +8,12 @@

extern spinlock_t i8253_lock;

+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+
extern struct clock_event_device *global_clock_event;

extern void setup_pit_timer(void);

+#endif
+
#endif /* __ASM_I8253_H__ */

--

-
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