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36 * libcfs/include/libcfs/user-bitops.h
38 * Author: Nikita Danilov <nikita@clusterfs.com>
41 #ifndef __LIBCFS_USER_BITOPS_H__
42 #define __LIBCFS_USER_BITOPS_H__
44 /* test if bit nr is set in bitmap addr; returns previous value of bit nr */
45 static inline int test_and_set_bit(int nr, unsigned long *addr)
49 addr += nr / BITS_PER_LONG;
50 mask = 1UL << (nr & (BITS_PER_LONG - 1));
51 nr = (mask & *addr) != 0;
56 #define set_bit(n, a) test_and_set_bit(n, a)
58 /* clear bit nr in bitmap addr; returns previous value of bit nr*/
59 static inline int test_and_clear_bit(int nr, unsigned long *addr)
63 addr += nr / BITS_PER_LONG;
64 mask = 1UL << (nr & (BITS_PER_LONG - 1));
65 nr = (mask & *addr) != 0;
70 #define clear_bit(n, a) test_and_clear_bit(n, a)
72 static inline int test_bit(int nr, const unsigned long *addr)
74 return ((1UL << (nr & (BITS_PER_LONG - 1))) &
75 ((addr)[nr / BITS_PER_LONG])) != 0;
78 /* using binary seach */
79 static __inline__ unsigned long __cfs_fls(long data)
86 #if BITS_PER_LONG == 64
87 /* If any bit of the high 32 bits are set, shift the high
88 * 32 bits down and pretend like it is a 32-bit value. */
89 if ((data & 0xFFFFFFFF00000000llu)) {
95 if (!(data & 0xFFFF0000u)) {
99 if (!(data & 0xFF000000u)) {
103 if (!(data & 0xF0000000u)) {
107 if (!(data & 0xC0000000u)) {
111 if (!(data & 0x80000000u)) {
118 static __inline__ unsigned long __cfs_ffs(long data)
122 #if BITS_PER_LONG == 64
123 if ((data & 0xFFFFFFFF) == 0) {
128 if ((data & 0xFFFF) == 0) {
132 if ((data & 0xFF) == 0) {
136 if ((data & 0xF) == 0) {
140 if ((data & 0x3) == 0) {
144 if ((data & 0x1) == 0)
150 #define __cfs_ffz(x) __cfs_ffs(~(x))
151 #define __cfs_flz(x) __cfs_fls(~(x))
153 unsigned long find_next_bit(unsigned long *addr,
154 unsigned long size, unsigned long offset);
156 unsigned long find_next_zero_bit(unsigned long *addr,
157 unsigned long size, unsigned long offset);
159 #define find_first_bit(addr, size) find_next_bit((addr), (size),0)
160 #define find_first_zero_bit(addr, size) find_next_zero_bit((addr), (size),0)