From 77c8554e4d7db8d04f03ee92d186bd87f74e3773 Mon Sep 17 00:00:00 2001 From: Fabio Estevam Date: Thu, 5 Nov 2015 12:43:23 -0200 Subject: include: Add generic bitops headers Use the generic bitops header files from the kernel. Imported from kernel 4.2.3. Signed-off-by: Fabio Estevam --- include/asm-generic/bitops/fls.h | 41 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 include/asm-generic/bitops/fls.h (limited to 'include/asm-generic/bitops/fls.h') diff --git a/include/asm-generic/bitops/fls.h b/include/asm-generic/bitops/fls.h new file mode 100644 index 0000000..0576d1f --- /dev/null +++ b/include/asm-generic/bitops/fls.h @@ -0,0 +1,41 @@ +#ifndef _ASM_GENERIC_BITOPS_FLS_H_ +#define _ASM_GENERIC_BITOPS_FLS_H_ + +/** + * fls - find last (most-significant) bit set + * @x: the word to search + * + * This is defined the same way as ffs. + * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. + */ + +static __always_inline int fls(int x) +{ + int r = 32; + + if (!x) + return 0; + if (!(x & 0xffff0000u)) { + x <<= 16; + r -= 16; + } + if (!(x & 0xff000000u)) { + x <<= 8; + r -= 8; + } + if (!(x & 0xf0000000u)) { + x <<= 4; + r -= 4; + } + if (!(x & 0xc0000000u)) { + x <<= 2; + r -= 2; + } + if (!(x & 0x80000000u)) { + x <<= 1; + r -= 1; + } + return r; +} + +#endif /* _ASM_GENERIC_BITOPS_FLS_H_ */ -- cgit v1.1