[PATCH for review] [12/48] x86_64: use the global PIT lock

From: Andi Kleen
Date: Thu Jul 19 2007 - 09:54:29 EST



From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

Replace the pcspkr private PIT lock by the global PIT lock to serialize the
PIT access all over the place.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andi Kleen <ak@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Dmitry Torokhov <dtor@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

arch/x86_64/kernel/time.c | 2 ++
drivers/input/misc/pcspkr.c | 11 ++++++++---
include/asm-x86_64/i8253.h | 6 ++++++
3 files changed, 16 insertions(+), 3 deletions(-)

Index: linux/arch/x86_64/kernel/time.c
===================================================================
--- linux.orig/arch/x86_64/kernel/time.c
+++ linux/arch/x86_64/kernel/time.c
@@ -33,6 +33,7 @@
#include <acpi/acpi_bus.h>
#endif
#include <asm/8253pit.h>
+#include <asm/i8253.h>
#include <asm/pgtable.h>
#include <asm/vsyscall.h>
#include <asm/timex.h>
@@ -51,6 +52,7 @@ static char *timename = NULL;
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);
DEFINE_SPINLOCK(i8253_lock);
+EXPORT_SYMBOL(i8253_lock);

volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES;

Index: linux/drivers/input/misc/pcspkr.c
===================================================================
--- linux.orig/drivers/input/misc/pcspkr.c
+++ linux/drivers/input/misc/pcspkr.c
@@ -24,7 +24,12 @@ MODULE_AUTHOR("Vojtech Pavlik <vojtech@u
MODULE_DESCRIPTION("PC Speaker beeper driver");
MODULE_LICENSE("GPL");

-static DEFINE_SPINLOCK(i8253_beep_lock);
+#ifdef CONFIG_X86
+/* Use the global PIT lock ! */
+#include <asm/i8253.h>
+#else
+static DEFINE_SPINLOCK(i8253_lock);
+#endif

static int pcspkr_event(struct input_dev *dev, unsigned int type, unsigned int code, int value)
{
@@ -43,7 +48,7 @@ static int pcspkr_event(struct input_dev
if (value > 20 && value < 32767)
count = PIT_TICK_RATE / value;

- spin_lock_irqsave(&i8253_beep_lock, flags);
+ spin_lock_irqsave(&i8253_lock, flags);

if (count) {
/* enable counter 2 */
@@ -58,7 +63,7 @@ static int pcspkr_event(struct input_dev
outb(inb_p(0x61) & 0xFC, 0x61);
}

- spin_unlock_irqrestore(&i8253_beep_lock, flags);
+ spin_unlock_irqrestore(&i8253_lock, flags);

return 0;
}
Index: linux/include/asm-x86_64/i8253.h
===================================================================
--- /dev/null
+++ linux/include/asm-x86_64/i8253.h
@@ -0,0 +1,6 @@
+#ifndef __ASM_I8253_H__
+#define __ASM_I8253_H__
+
+extern spinlock_t i8253_lock;
+
+#endif /* __ASM_I8253_H__ */
-
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