From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Mon, 28 Oct 2013 12:19:57 +0100
Subject: wait.h: include atomic.h
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.6/older/patches-4.6.2-rt5.tar.xz

|  CC      init/main.o
|In file included from include/linux/mmzone.h:9:0,
|                 from include/linux/gfp.h:4,
|                 from include/linux/kmod.h:22,
|                 from include/linux/module.h:13,
|                 from init/main.c:15:
|include/linux/wait.h: In function ‘wait_on_atomic_t’:
|include/linux/wait.h:982:2: error: implicit declaration of function ‘atomic_read’ [-Werror=implicit-function-declaration]
|  if (atomic_read(val) == 0)
|  ^

This pops up on ARM. Non-RT gets its atomic.h include from spinlock.h

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 include/linux/wait.h |    1 +
 1 file changed, 1 insertion(+)

--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -8,6 +8,7 @@
 #include <linux/spinlock.h>
 #include <asm/current.h>
 #include <uapi/linux/wait.h>
+#include <linux/atomic.h>
 
 typedef struct __wait_queue wait_queue_t;
 typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key);
