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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Nathan Scott7b718762005-11-02 14:58:39 +11002 * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 *
Nathan Scott7b718762005-11-02 14:58:39 +11005 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * published by the Free Software Foundation.
8 *
Nathan Scott7b718762005-11-02 14:58:39 +11009 * 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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070013 *
Nathan Scott7b718762005-11-02 14:58:39 +110014 * 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
Linus Torvalds1da177e2005-04-16 15:20:36 -070017 */
18#ifndef __XFS_BIT_H__
19#define __XFS_BIT_H__
20
21/*
22 * XFS bit manipulation routines.
23 */
24
25/*
26 * masks with n high/low bits set, 32-bit values & 64-bit values
27 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#define XFS_MASK32HI(n) xfs_mask32hi(n)
Nathan Scotta844f452005-11-02 14:38:42 +110029static inline __uint32_t xfs_mask32hi(int n)
30{
31 return (__uint32_t)-1 << (32 - (n));
32}
Linus Torvalds1da177e2005-04-16 15:20:36 -070033#define XFS_MASK64HI(n) xfs_mask64hi(n)
Nathan Scotta844f452005-11-02 14:38:42 +110034static inline __uint64_t xfs_mask64hi(int n)
35{
36 return (__uint64_t)-1 << (64 - (n));
37}
Linus Torvalds1da177e2005-04-16 15:20:36 -070038#define XFS_MASK32LO(n) xfs_mask32lo(n)
Nathan Scotta844f452005-11-02 14:38:42 +110039static inline __uint32_t xfs_mask32lo(int n)
40{
41 return ((__uint32_t)1 << (n)) - 1;
42}
Linus Torvalds1da177e2005-04-16 15:20:36 -070043#define XFS_MASK64LO(n) xfs_mask64lo(n)
Nathan Scotta844f452005-11-02 14:38:42 +110044static inline __uint64_t xfs_mask64lo(int n)
45{
46 return ((__uint64_t)1 << (n)) - 1;
47}
Linus Torvalds1da177e2005-04-16 15:20:36 -070048
49/* Get high bit set out of 32-bit argument, -1 if none set */
David Chinner79071eb2008-08-13 15:41:12 +100050static inline int xfs_highbit32(__uint32_t v)
51{
52 return fls(v) - 1;
53}
Lachlan McIlroyef8ece52008-02-26 17:00:22 +110054
55/* Get high bit set out of 64-bit argument, -1 if none set */
David Chinner79071eb2008-08-13 15:41:12 +100056static inline int xfs_highbit64(__uint64_t v)
57{
58 return fls64(v) - 1;
59}
60
61/* Get low bit set out of 32-bit argument, -1 if none set */
62static inline int xfs_lowbit32(__uint32_t v)
63{
64 unsigned long t = v;
65 return (v) ? find_first_bit(&t, 32) : -1;
66}
67
68/* Get low bit set out of 64-bit argument, -1 if none set */
69static inline int xfs_lowbit64(__uint64_t v)
70{
71 __uint32_t w = (__uint32_t)v;
72 int n = 0;
73
74 if (w) { /* lower bits */
75 n = ffs(w);
76 } else { /* upper bits */
77 w = (__uint32_t)(v >> 32);
78 if (w && (n = ffs(w)))
79 n += 32;
80 }
81 return n - 1;
82}
Linus Torvalds1da177e2005-04-16 15:20:36 -070083
Eric Sandeen24ad33f2007-06-28 16:43:30 +100084/* Return whether bitmap is empty (1 == empty) */
85extern int xfs_bitmap_empty(uint *map, uint size);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086
87/* Count continuous one bits in map starting with start_bit */
88extern int xfs_contig_bits(uint *map, uint size, uint start_bit);
89
90/* Find next set bit in map */
91extern int xfs_next_bit(uint *map, uint size, uint start_bit);
92
93#endif /* __XFS_BIT_H__ */