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author | Fabio Estevam <fabio.estevam@freescale.com> | 2015-11-05 14:43:23 (GMT) |
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committer | Tom Rini <trini@konsulko.com> | 2015-11-05 15:51:57 (GMT) |
commit | 77c8554e4d7db8d04f03ee92d186bd87f74e3773 (patch) | |
tree | 709b900ed22641760b41ca9880679eab2b36c2eb /include/asm-generic/bitops/fls.h | |
parent | f598e7a99eda286d4c0883e440b5f81c8ac050f3 (diff) | |
download | u-boot-77c8554e4d7db8d04f03ee92d186bd87f74e3773.tar.xz |
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 <fabio.estevam@freescale.com>
Diffstat (limited to 'include/asm-generic/bitops/fls.h')
-rw-r--r-- | include/asm-generic/bitops/fls.h | 41 |
1 files changed, 41 insertions, 0 deletions
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_ */ |