From 81615b624a45621b758380ec45d750483eae281d Mon Sep 17 00:00:00 2001
From: Ingo Molnar <mingo@elte.hu>
Date: Mon, 26 Jun 2006 00:24:32 -0700
Subject: [PATCH] [PATCH] Convert kernel/cpu.c to mutexes

Convert kernel/cpu.c from semaphore to mutex.

I've reviewed all lock_cpu_hotplug() critical sections, and they all seem to
fit mutex semantics.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
---
 kernel/cpu.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/kernel/cpu.c b/kernel/cpu.c
index fe2b8d0bfe4c..03dcd981846a 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -13,10 +13,10 @@
 #include <linux/module.h>
 #include <linux/kthread.h>
 #include <linux/stop_machine.h>
-#include <asm/semaphore.h>
+#include <linux/mutex.h>
 
 /* This protects CPUs going up and down... */
-static DECLARE_MUTEX(cpucontrol);
+static DEFINE_MUTEX(cpucontrol);
 
 static BLOCKING_NOTIFIER_HEAD(cpu_chain);
 
@@ -30,9 +30,9 @@ static int __lock_cpu_hotplug(int interruptible)
 
 	if (lock_cpu_hotplug_owner != current) {
 		if (interruptible)
-			ret = down_interruptible(&cpucontrol);
+			ret = mutex_lock_interruptible(&cpucontrol);
 		else
-			down(&cpucontrol);
+			mutex_lock(&cpucontrol);
 	}
 
 	/*
@@ -56,7 +56,7 @@ void unlock_cpu_hotplug(void)
 {
 	if (--lock_cpu_hotplug_depth == 0) {
 		lock_cpu_hotplug_owner = NULL;
-		up(&cpucontrol);
+		mutex_unlock(&cpucontrol);
 	}
 }
 EXPORT_SYMBOL_GPL(unlock_cpu_hotplug);