From ad4f99e888192e53d463cab75075e88e65ad7d50 Mon Sep 17 00:00:00 2001
From: Dominik Dingel <dingel@linux.vnet.ibm.com>
Date: Fri, 17 Jul 2015 16:23:31 -0700
Subject: revert "s390/mm: change HPAGE_SHIFT type to int"

Heiko noticed that the current check for hugepage support on s390 is a
little bit too harsh as systems which do not support will crash.

The reason is that pageblock_order can now get negative when we set
HPAGE_SHIFT to 0.  To avoid all this and to avoid opening another can of
worms with enabling HUGETLB_PAGE_SIZE_VARIABLE I think it would be best
to simply allow architectures to define their own hugepages_supported().

This patch (of 4): revert commit cf54e2fce51c ("s390/mm: change
HPAGE_SHIFT type to int") in preparation.

Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h
index dd34523..0844b78 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -20,7 +20,7 @@
 #include <asm/setup.h>
 #ifndef __ASSEMBLY__
 
-extern int HPAGE_SHIFT;
+extern unsigned int HPAGE_SHIFT;
 #define HPAGE_SIZE	(1UL << HPAGE_SHIFT)
 #define HPAGE_MASK	(~(HPAGE_SIZE - 1))
 #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 33082d0..16154720 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -31,7 +31,7 @@
 #define ALLOC_ORDER	2
 #define FRAG_MASK	0x03
 
-int HPAGE_SHIFT;
+unsigned int HPAGE_SHIFT;
 
 unsigned long *crst_table_alloc(struct mm_struct *mm)
 {
-- 
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