projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 | 1 | /* |
| 7b718769 NS |
2 | * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc. |
| 3 | * All Rights Reserved. | |
| 1da177e4 | 4 | * |
| 7b718769 NS |
5 | * This program is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU General Public License as | |
| 1da177e4 LT |
7 | * published by the Free Software Foundation. |
| 8 | * | |
| 7b718769 NS |
9 | * This program is distributed in the hope that it would be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 12 | * GNU General Public License for more details. | |
| 1da177e4 | 13 | * |
| 7b718769 NS |
14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write the Free Software Foundation, | |
| 16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
| 1da177e4 LT |
17 | */ |
| 18 | #ifndef __XFS_BIT_H__ | |
| 19 | #define __XFS_BIT_H__ | |
| 20 | ||
| 21 | /* | |
| 22 | * XFS bit manipulation routines. | |
| 23 | */ | |
| 24 | ||
| 25 | /* | |
| fb82557f | 26 | * masks with n high/low bits set, 64-bit values |
| 1da177e4 | 27 | */ |
| a844f451 NS |
28 | static inline __uint64_t xfs_mask64hi(int n) |
| 29 | { | |
| 30 | return (__uint64_t)-1 << (64 - (n)); | |
| 31 | } | |
| a844f451 NS |
32 | static inline __uint32_t xfs_mask32lo(int n) |
| 33 | { | |
| 34 | return ((__uint32_t)1 << (n)) - 1; | |
| 35 | } | |
| a844f451 NS |
36 | static inline __uint64_t xfs_mask64lo(int n) |
| 37 | { | |
| 38 | return ((__uint64_t)1 << (n)) - 1; | |
| 39 | } | |
| 1da177e4 LT |
40 | |
| 41 | /* Get high bit set out of 32-bit argument, -1 if none set */ | |
| 79071eb0 DC |
42 | static inline int xfs_highbit32(__uint32_t v) |
| 43 | { | |
| 44 | return fls(v) - 1; | |
| 45 | } | |
| 46 | ||
| 47 | /* Get high bit set out of 64-bit argument, -1 if none set */ | |
| 48 | static inline int xfs_highbit64(__uint64_t v) | |
| 49 | { | |
| 50 | return fls64(v) - 1; | |
| 51 | } | |
| 52 | ||
| 53 | /* Get low bit set out of 32-bit argument, -1 if none set */ | |
| 54 | static inline int xfs_lowbit32(__uint32_t v) | |
| 55 | { | |
| 847fff5c | 56 | return ffs(v) - 1; |
| 79071eb0 | 57 | } |
| a69b176d DC |
58 | |
| 59 | /* Get low bit set out of 64-bit argument, -1 if none set */ | |
| 79071eb0 DC |
60 | static inline int xfs_lowbit64(__uint64_t v) |
| 61 | { | |
| 62 | __uint32_t w = (__uint32_t)v; | |
| 63 | int n = 0; | |
| ef8ece55 | 64 | |
| 79071eb0 DC |
65 | if (w) { /* lower bits */ |
| 66 | n = ffs(w); | |
| 67 | } else { /* upper bits */ | |
| 68 | w = (__uint32_t)(v >> 32); | |
| 69 | if (w && (n = ffs(w))) | |
| 70 | n += 32; | |
| 71 | } | |
| 72 | return n - 1; | |
| 73 | } | |
| 1da177e4 | 74 | |
| 24ad33ff ES |
75 | /* Return whether bitmap is empty (1 == empty) */ |
| 76 | extern int xfs_bitmap_empty(uint *map, uint size); | |
| 1da177e4 LT |
77 | |
| 78 | /* Count continuous one bits in map starting with start_bit */ | |
| 79 | extern int xfs_contig_bits(uint *map, uint size, uint start_bit); | |
| 80 | ||
| 81 | /* Find next set bit in map */ | |
| 82 | extern int xfs_next_bit(uint *map, uint size, uint start_bit); | |
| 83 | ||
| 84 | #endif /* __XFS_BIT_H__ */ |