From c725c69d77fba9466cada018db8673136c6868e9 Mon Sep 17 00:00:00 2001
From: Leah Neukirchen <leah@vuxu.org>
Date: Fri, 9 Feb 2018 22:21:46 +0100
Subject: [PATCH] include/linux/log2.h: define PAGE_SHIFT when needed

---
 include/linux/log2.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/log2.h b/include/linux/log2.h
index 1f977d60..96f62458 100644
--- a/include/linux/log2.h
+++ b/include/linux/log2.h
@@ -12,7 +12,13 @@
 #ifndef _TOOLS_LINUX_LOG2_H
 #define _TOOLS_LINUX_LOG2_H
 
+#include <limits.h>
+#ifndef PAGE_SHIFT
+#define PAGE_SHIFT ilog2(PAGE_SIZE)
+#endif
+
 #include <linux/bitops.h>
+#include <linux/compiler.h>
 
 /*
  * deal with unrepresentable constant logarithms