ARM: 7957/1: add DSB after icache flush in __flush_icache_all()

commit 39544ac9 upstream.

Add DSB after icache flush to complete the cache maintenance operation.
Signed-off-by: Vinayak Kale <vkale@apm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/arm/include/asm/cacheflush.h

@@ -202,6 +202,7 @@ extern void copy_to_user_page(struct vm_area_struct *, struct page *,
 static inline void __flush_icache_all(void)
 {
 	__flush_icache_preferred();
+	dsb();
 }
 
 #define flush_cache_all()		__cpuc_flush_kern_all()