ARM: outer cache: add WARN_ON() to outer_disable()

Add WARN_ON() conditions to outer_disable() to ensure that its
requirements aren't violated.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/outercache.h

@@ -96,11 +96,7 @@ static inline void outer_flush_all(void)
  * cache is pushed out to lower levels of system memory.  The note and
  * conditions above concerning outer_flush_all() applies here.
  */
-static inline void outer_disable(void)
-{
-	if (outer_cache.disable)
-		outer_cache.disable();
-}
+extern void outer_disable(void);
 
 /**
  * outer_resume - restore the cache configuration and re-enable outer cache

arch/arm/mm/Makefile

@@ -95,6 +95,7 @@ obj-$(CONFIG_CPU_V7M)		+= proc-v7m.o
 AFLAGS_proc-v6.o	:=-Wa,-march=armv6
 AFLAGS_proc-v7.o	:=-Wa,-march=armv7-a
 
+obj-$(CONFIG_OUTER_CACHE)	+= l2c-common.o
 obj-$(CONFIG_CACHE_FEROCEON_L2)	+= cache-feroceon-l2.o
 obj-$(CONFIG_CACHE_L2X0)	+= cache-l2x0.o
 obj-$(CONFIG_CACHE_XSC3L2)	+= cache-xsc3l2.o

arch/arm/mm/l2c-common.c

@@ -0,0 +1,20 @@
+/*
+ * Copyright (C) 2010 ARM Ltd.
+ * Written by Catalin Marinas <catalin.marinas@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/bug.h>
+#include <linux/smp.h>
+#include <asm/outercache.h>
+
+void outer_disable(void)
+{
+	WARN_ON(!irqs_disabled());
+	WARN_ON(num_online_cpus() > 1);
+
+	if (outer_cache.disable)
+		outer_cache.disable();
+}