1 /*
2 * Copyright 1995, Russell King.
3 * Various bits and pieces copyrights include:
4 * Linus Torvalds (test_bit).
5 *
6 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
7 *
8 * Please note that the code in this file should never be included
9 * from user space. Many of these are not implemented in assembler
10 * since they would be too costly. Also, they require priviledged
11 * instructions (which are not available from user mode) to ensure
12 * that they are atomic.
13 */
14
15 #ifndef __ASM_ARM_BITOPS_H
16 #define __ASM_ARM_BITOPS_H
17
18 #include <asm-generic/bitops/__ffs.h>
19
20 #ifdef __KERNEL__
21
22 #include <asm/proc-armv/system.h>
23
24 #define smp_mb__before_clear_bit() do { } while (0)
25 #define smp_mb__after_clear_bit() do { } while (0)
26
27 /*
28 * Function prototypes to keep gcc -Wall happy.
29 */
30 extern void set_bit(int nr, volatile void * addr);
31
32 extern void clear_bit(int nr, volatile void * addr);
33
34 extern void change_bit(int nr, volatile void * addr);
35
__change_bit(int nr,volatile void * addr)36 static inline void __change_bit(int nr, volatile void *addr)
37 {
38 unsigned long mask = BIT_MASK(nr);
39 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
40
41 *p ^= mask;
42 }
43
__test_and_set_bit(int nr,volatile void * addr)44 static inline int __test_and_set_bit(int nr, volatile void *addr)
45 {
46 unsigned long mask = BIT_MASK(nr);
47 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
48 unsigned long old = *p;
49
50 *p = old | mask;
51 return (old & mask) != 0;
52 }
53
test_and_set_bit(int nr,volatile void * addr)54 static inline int test_and_set_bit(int nr, volatile void * addr)
55 {
56 unsigned long flags = 0;
57 int out;
58
59 local_irq_save(flags);
60 out = __test_and_set_bit(nr, addr);
61 local_irq_restore(flags);
62
63 return out;
64 }
65
__test_and_clear_bit(int nr,volatile void * addr)66 static inline int __test_and_clear_bit(int nr, volatile void *addr)
67 {
68 unsigned long mask = BIT_MASK(nr);
69 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
70 unsigned long old = *p;
71
72 *p = old & ~mask;
73 return (old & mask) != 0;
74 }
75
test_and_clear_bit(int nr,volatile void * addr)76 static inline int test_and_clear_bit(int nr, volatile void * addr)
77 {
78 unsigned long flags = 0;
79 int out;
80
81 local_irq_save(flags);
82 out = __test_and_clear_bit(nr, addr);
83 local_irq_restore(flags);
84
85 return out;
86 }
87
88 extern int test_and_change_bit(int nr, volatile void * addr);
89
__test_and_change_bit(int nr,volatile void * addr)90 static inline int __test_and_change_bit(int nr, volatile void *addr)
91 {
92 unsigned long mask = BIT_MASK(nr);
93 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
94 unsigned long old = *p;
95
96 *p = old ^ mask;
97 return (old & mask) != 0;
98 }
99
100 /*
101 * This routine doesn't need to be atomic.
102 */
test_bit(int nr,const void * addr)103 static inline int test_bit(int nr, const void * addr)
104 {
105 return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7));
106 }
107
__ilog2(unsigned int x)108 static inline int __ilog2(unsigned int x)
109 {
110 return generic_fls(x) - 1;
111 }
112
113 #define ffz(x) __ffs(~(x))
114
find_next_zero_bit(void * addr,int size,int offset)115 static inline int find_next_zero_bit(void *addr, int size, int offset)
116 {
117 unsigned long *p = ((unsigned long *)addr) + (offset / BITS_PER_LONG);
118 unsigned long result = offset & ~(BITS_PER_LONG - 1);
119 unsigned long tmp;
120
121 if (offset >= size)
122 return size;
123 size -= result;
124 offset &= (BITS_PER_LONG - 1);
125 if (offset) {
126 tmp = *(p++);
127 tmp |= ~0UL >> (BITS_PER_LONG - offset);
128 if (size < BITS_PER_LONG)
129 goto found_first;
130 if (~tmp)
131 goto found_middle;
132 size -= BITS_PER_LONG;
133 result += BITS_PER_LONG;
134 }
135 while (size & ~(BITS_PER_LONG - 1)) {
136 tmp = *(p++);
137 if (~tmp)
138 goto found_middle;
139 result += BITS_PER_LONG;
140 size -= BITS_PER_LONG;
141 }
142 if (!size)
143 return result;
144 tmp = *p;
145
146 found_first:
147 tmp |= ~0UL << size;
148 found_middle:
149 return result + ffz(tmp);
150 }
151
152 /*
153 * hweightN: returns the hamming weight (i.e. the number
154 * of bits set) of a N-bit word
155 */
156
157 #define hweight32(x) generic_hweight32(x)
158 #define hweight16(x) generic_hweight16(x)
159 #define hweight8(x) generic_hweight8(x)
160
161 #define find_first_zero_bit(addr, size) \
162 find_next_zero_bit((addr), (size), 0)
163
164 #define ext2_set_bit test_and_set_bit
165 #define ext2_clear_bit test_and_clear_bit
166 #define ext2_test_bit test_bit
167 #define ext2_find_first_zero_bit find_first_zero_bit
168 #define ext2_find_next_zero_bit find_next_zero_bit
169
170 /* Bitmap functions for the minix filesystem. */
171 #define minix_test_and_set_bit(nr,addr) test_and_set_bit(nr,addr)
172 #define minix_set_bit(nr,addr) set_bit(nr,addr)
173 #define minix_test_and_clear_bit(nr,addr) test_and_clear_bit(nr,addr)
174 #define minix_test_bit(nr,addr) test_bit(nr,addr)
175 #define minix_find_first_zero_bit(addr,size) find_first_zero_bit(addr,size)
176
177 #endif /* __KERNEL__ */
178
179 #include <asm-generic/bitops/__fls.h>
180 #include <asm-generic/bitops/fls.h>
181 #include <asm-generic/bitops/fls64.h>
182
183 #endif /* _ARM_BITOPS_H */
184