diff options
Diffstat (limited to 'fs/xfs/libxfs/xfs_bit.h')
-rw-r--r-- | fs/xfs/libxfs/xfs_bit.h | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_bit.h b/fs/xfs/libxfs/xfs_bit.h new file mode 100644 index 000000000..a04f266ae --- /dev/null +++ b/fs/xfs/libxfs/xfs_bit.h @@ -0,0 +1,75 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc. + * All Rights Reserved. + */ +#ifndef __XFS_BIT_H__ +#define __XFS_BIT_H__ + +/* + * XFS bit manipulation routines. + */ + +/* + * masks with n high/low bits set, 64-bit values + */ +static inline uint64_t xfs_mask64hi(int n) +{ + return (uint64_t)-1 << (64 - (n)); +} +static inline uint32_t xfs_mask32lo(int n) +{ + return ((uint32_t)1 << (n)) - 1; +} +static inline uint64_t xfs_mask64lo(int n) +{ + return ((uint64_t)1 << (n)) - 1; +} + +/* Get high bit set out of 32-bit argument, -1 if none set */ +static inline int xfs_highbit32(uint32_t v) +{ + return fls(v) - 1; +} + +/* Get high bit set out of 64-bit argument, -1 if none set */ +static inline int xfs_highbit64(uint64_t v) +{ + return fls64(v) - 1; +} + +/* Get low bit set out of 32-bit argument, -1 if none set */ +static inline int xfs_lowbit32(uint32_t v) +{ + return ffs(v) - 1; +} + +/* Get low bit set out of 64-bit argument, -1 if none set */ +static inline int xfs_lowbit64(uint64_t v) +{ + uint32_t w = (uint32_t)v; + int n = 0; + + if (w) { /* lower bits */ + n = ffs(w); + } else { /* upper bits */ + w = (uint32_t)(v >> 32); + if (w) { + n = ffs(w); + if (n) + n += 32; + } + } + return n - 1; +} + +/* Return whether bitmap is empty (1 == empty) */ +extern int xfs_bitmap_empty(uint *map, uint size); + +/* Count continuous one bits in map starting with start_bit */ +extern int xfs_contig_bits(uint *map, uint size, uint start_bit); + +/* Find next set bit in map */ +extern int xfs_next_bit(uint *map, uint size, uint start_bit); + +#endif /* __XFS_BIT_H__ */ |