On most architectures[*], gcc turns __builtin_ffsll() into a call to
__ffsdi2(), which is not provided by any architecture, leading to
failures like:
rcar-gen3-cpg.c:(.text+0x289): undefined reference to `__ffsdi2'
To fix this, use __ffs64() instead, which is available on all
architectures.
[*] Known exceptions are some 64-bit architectures like amd64, arm64,
ia64, powerpc64, and tilegx.
Reported-by: kbuild test robot <[email protected]>
Fixes: 3e9b3112ec74f192 ("add basic register-field manipulation macros")
Signed-off-by: Geert Uytterhoeven <[email protected]>
---
include/linux/bitfield.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/bitfield.h b/include/linux/bitfield.h
index 8b9d6fff002db113..0a827677372756fa 100644
--- a/include/linux/bitfield.h
+++ b/include/linux/bitfield.h
@@ -15,6 +15,7 @@
#ifndef _LINUX_BITFIELD_H
#define _LINUX_BITFIELD_H
+#include <linux/bitops.h>
#include <linux/bug.h>
/*
@@ -46,7 +47,7 @@
* reg |= FIELD_PREP(REG_FIELD_C, c);
*/
-#define __bf_shf(x) (__builtin_ffsll(x) - 1)
+#define __bf_shf(x) __ffs64(x)
#define __BF_FIELD_CHECK(_mask, _reg, _val, _pfx) \
({ \
--
2.7.4
