mirror of https://gitee.com/openkylin/linux.git
76 lines
1.5 KiB
C
76 lines
1.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
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* All Rights Reserved.
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*/
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#ifndef __XFS_BIT_H__
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#define __XFS_BIT_H__
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/*
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* XFS bit manipulation routines.
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*/
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/*
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* masks with n high/low bits set, 64-bit values
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*/
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static inline uint64_t xfs_mask64hi(int n)
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{
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return (uint64_t)-1 << (64 - (n));
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}
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static inline uint32_t xfs_mask32lo(int n)
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{
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return ((uint32_t)1 << (n)) - 1;
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}
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static inline uint64_t xfs_mask64lo(int n)
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{
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return ((uint64_t)1 << (n)) - 1;
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}
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/* Get high bit set out of 32-bit argument, -1 if none set */
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static inline int xfs_highbit32(uint32_t v)
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{
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return fls(v) - 1;
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}
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/* Get high bit set out of 64-bit argument, -1 if none set */
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static inline int xfs_highbit64(uint64_t v)
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{
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return fls64(v) - 1;
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}
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/* Get low bit set out of 32-bit argument, -1 if none set */
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static inline int xfs_lowbit32(uint32_t v)
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{
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return ffs(v) - 1;
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}
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/* Get low bit set out of 64-bit argument, -1 if none set */
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static inline int xfs_lowbit64(uint64_t v)
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{
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uint32_t w = (uint32_t)v;
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int n = 0;
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if (w) { /* lower bits */
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n = ffs(w);
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} else { /* upper bits */
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w = (uint32_t)(v >> 32);
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if (w) {
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n = ffs(w);
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if (n)
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n += 32;
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}
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}
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return n - 1;
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}
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/* Return whether bitmap is empty (1 == empty) */
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extern int xfs_bitmap_empty(uint *map, uint size);
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/* Count continuous one bits in map starting with start_bit */
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extern int xfs_contig_bits(uint *map, uint size, uint start_bit);
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/* Find next set bit in map */
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extern int xfs_next_bit(uint *map, uint size, uint start_bit);
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#endif /* __XFS_BIT_H__ */
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