[PATCH] mm/ARM: fix ARMs __ffs() to conform to avoid warning with NO_BOOTMEM

From: Santosh Shilimkar
Date: Fri Dec 13 2013 - 19:38:53 EST


Building ARM with NO_BOOTMEM generates below warning.

mm/nobootmem.c: In function _____free_pages_memory___:
mm/nobootmem.c:88:11: warning: comparison of distinct pointer types lacks a cast

order = min(MAX_ORDER - 1UL, __ffs(start));

ARM's __ffs() differs from other architectures in that it ends up being
an int, whereas almost everyone else is unsigned long.

So fix ARMs __ffs() to conform to other architectures. Suggested by
Russell King <linux@xxxxxxxxxxxxxxxx>

Some more details in below thread -
https://lkml.org/lkml/2013/12/9/807

Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
---
arch/arm/include/asm/bitops.h | 23 +++++++++++++++++++----
1 file changed, 19 insertions(+), 4 deletions(-)

diff --git a/arch/arm/include/asm/bitops.h b/arch/arm/include/asm/bitops.h
index e691ec9..5f41d81 100644
--- a/arch/arm/include/asm/bitops.h
+++ b/arch/arm/include/asm/bitops.h
@@ -270,10 +270,25 @@ static inline int fls(int x)
return ret;
}

-#define __fls(x) (fls(x) - 1)
-#define ffs(x) ({ unsigned long __t = (x); fls(__t & -__t); })
-#define __ffs(x) (ffs(x) - 1)
-#define ffz(x) __ffs( ~(x) )
+static inline unsigned long __fls(unsigned long x)
+{
+ return fls(x) - 1;
+}
+
+static inline int ffs(int x)
+{
+ return fls(x & -x);
+}
+
+static inline unsigned long __ffs(unsigned long x)
+{
+ return ffs(x) - 1;
+}
+
+static inline unsigned long ffz(unsigned long x)
+{
+ return __ffs(~x);
+}

#endif

--
1.7.9.5

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