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34 * libcfs/include/libcfs/user-bitops.h
36 * Author: Nikita Danilov <nikita@clusterfs.com>
39 #ifndef __LIBCFS_USER_BITOPS_H__
40 #define __LIBCFS_USER_BITOPS_H__
42 /* test if bit nr is set in bitmap addr; returns previous value of bit nr */
43 static inline int test_and_set_bit(int nr, unsigned long *addr)
47 addr += nr / BITS_PER_LONG;
48 mask = 1UL << (nr & (BITS_PER_LONG - 1));
49 nr = (mask & *addr) != 0;
54 #define set_bit(n, a) test_and_set_bit(n, a)
56 /* clear bit nr in bitmap addr; returns previous value of bit nr*/
57 static inline int test_and_clear_bit(int nr, unsigned long *addr)
61 addr += nr / BITS_PER_LONG;
62 mask = 1UL << (nr & (BITS_PER_LONG - 1));
63 nr = (mask & *addr) != 0;
68 #define clear_bit(n, a) test_and_clear_bit(n, a)
70 static inline int test_bit(int nr, const unsigned long *addr)
72 return ((1UL << (nr & (BITS_PER_LONG - 1))) &
73 ((addr)[nr / BITS_PER_LONG])) != 0;
76 /* using binary seach */
77 static __inline__ unsigned long __cfs_fls(long data)
84 #if BITS_PER_LONG == 64
85 /* If any bit of the high 32 bits are set, shift the high
86 * 32 bits down and pretend like it is a 32-bit value. */
87 if ((data & 0xFFFFFFFF00000000llu)) {
93 if (!(data & 0xFFFF0000u)) {
97 if (!(data & 0xFF000000u)) {
101 if (!(data & 0xF0000000u)) {
105 if (!(data & 0xC0000000u)) {
109 if (!(data & 0x80000000u)) {
116 static __inline__ unsigned long __cfs_ffs(long data)
120 #if BITS_PER_LONG == 64
121 if ((data & 0xFFFFFFFF) == 0) {
126 if ((data & 0xFFFF) == 0) {
130 if ((data & 0xFF) == 0) {
134 if ((data & 0xF) == 0) {
138 if ((data & 0x3) == 0) {
142 if ((data & 0x1) == 0)
148 #define __cfs_ffz(x) __cfs_ffs(~(x))
149 #define __cfs_flz(x) __cfs_fls(~(x))
151 unsigned long find_next_bit(unsigned long *addr,
152 unsigned long size, unsigned long offset);
154 unsigned long find_next_zero_bit(unsigned long *addr,
155 unsigned long size, unsigned long offset);
157 #define find_first_bit(addr, size) find_next_bit((addr), (size),0)
158 #define find_first_zero_bit(addr, size) find_next_zero_bit((addr), (size),0)