From f8582257a0b6d6592f8276bdbd33bb611b139ca3 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@fb.com>
Date: Wed, 23 Dec 2015 09:09:23 -0700
Subject: [PATCH] arch: add ffs64 and ffz64

These just use the normal C software version, extended to 64-bit
even on 32-bit archs. The fast variant is still machine word native.

Signed-off-by: Jens Axboe <axboe@fb.com>
---
 arch/arch.h |  4 ----
 lib/ffz.h   | 19 +++++++++++++++----
 2 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/arch/arch.h b/arch/arch.h
index 5671b9a0..043e2838 100644
--- a/arch/arch.h
+++ b/arch/arch.h
@@ -63,11 +63,7 @@ extern unsigned long arch_flags;
 #include "arch-generic.h"
 #endif
 
-#ifdef ARCH_HAVE_FFZ
-#define ffz(bitmask)	arch_ffz(bitmask)
-#else
 #include "../lib/ffz.h"
-#endif
 
 #ifndef ARCH_HAVE_INIT
 static inline int arch_init(char *envp[])
diff --git a/lib/ffz.h b/lib/ffz.h
index eef612d1..e2c1b8e9 100644
--- a/lib/ffz.h
+++ b/lib/ffz.h
@@ -1,16 +1,16 @@
 #ifndef FIO_FFZ_H
 #define FIO_FFZ_H
 
-static inline int __ffs(unsigned long word)
+#include <inttypes.h>
+
+static inline int ffs64(uint64_t word)
 {
 	int r = 0;
 
-#if BITS_PER_LONG == 64
 	if ((word & 0xffffffff) == 0) {
 		r += 32;
 		word >>= 32;
 	}
-#endif
 	if (!(word & 0xffff)) {
 		word >>= 16;
 		r += 16;
@@ -35,9 +35,20 @@ static inline int __ffs(unsigned long word)
 	return r;
 }
 
+#ifndef ARCH_HAVE_FFZ
+
 static inline int ffz(unsigned long bitmask)
 {
-	return __ffs(~bitmask);
+	return ffs64(~bitmask);
+}
+
+#else
+#define ffz(bitmask)	arch_ffz(bitmask)
+#endif
+
+static inline int ffz64(uint64_t bitmask)
+{
+	return ffs64(~bitmask);
 }
 
 #endif
-- 
2.25.1