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 #ifdef __KERNEL__
19
20 #include <asm/proc-armv/system.h>
21
22 #define smp_mb__before_clear_bit() do { } while (0)
23 #define smp_mb__after_clear_bit() do { } while (0)
24
25 /*
26 * Function prototypes to keep gcc -Wall happy.
27 */
28 extern void set_bit(int nr, volatile void * addr);
29
30 extern void clear_bit(int nr, volatile void * addr);
31
32 extern void change_bit(int nr, volatile void * addr);
33
__change_bit(int nr,volatile void * addr)34 static inline void __change_bit(int nr, volatile void *addr)
35 {
36 unsigned long mask = BIT_MASK(nr);
37 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
38
39 *p ^= mask;
40 }
41
__test_and_set_bit(int nr,volatile void * addr)42 static inline int __test_and_set_bit(int nr, volatile void *addr)
43 {
44 unsigned long mask = BIT_MASK(nr);
45 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
46 unsigned long old = *p;
47
48 *p = old | mask;
49 return (old & mask) != 0;
50 }
51
test_and_set_bit(int nr,volatile void * addr)52 static inline int test_and_set_bit(int nr, volatile void * addr)
53 {
54 unsigned long flags = 0;
55 int out;
56
57 local_irq_save(flags);
58 out = __test_and_set_bit(nr, addr);
59 local_irq_restore(flags);
60
61 return out;
62 }
63
__test_and_clear_bit(int nr,volatile void * addr)64 static inline int __test_and_clear_bit(int nr, volatile void *addr)
65 {
66 unsigned long mask = BIT_MASK(nr);
67 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
68 unsigned long old = *p;
69
70 *p = old & ~mask;
71 return (old & mask) != 0;
72 }
73
test_and_clear_bit(int nr,volatile void * addr)74 static inline int test_and_clear_bit(int nr, volatile void * addr)
75 {
76 unsigned long flags = 0;
77 int out;
78
79 local_irq_save(flags);
80 out = __test_and_clear_bit(nr, addr);
81 local_irq_restore(flags);
82
83 return out;
84 }
85
86 extern int test_and_change_bit(int nr, volatile void * addr);
87
__test_and_change_bit(int nr,volatile void * addr)88 static inline int __test_and_change_bit(int nr, volatile void *addr)
89 {
90 unsigned long mask = BIT_MASK(nr);
91 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
92 unsigned long old = *p;
93
94 *p = old ^ mask;
95 return (old & mask) != 0;
96 }
97
98 /*
99 * This routine doesn't need to be atomic.
100 */
test_bit(int nr,const void * addr)101 static inline int test_bit(int nr, const void * addr)
102 {
103 return ((unsigned char *) addr)[nr >> 3] & (1U << (nr & 7));
104 }
105
__ilog2(unsigned int x)106 static inline int __ilog2(unsigned int x)
107 {
108 return generic_fls(x) - 1;
109 }
110
111 /*
112 * ffz = Find First Zero in word. Undefined if no zero exists,
113 * so code should check against ~0UL first..
114 */
ffz(unsigned long word)115 static inline unsigned long ffz(unsigned long word)
116 {
117 int k;
118
119 word = ~word;
120 k = 31;
121 if (word & 0x0000ffff) { k -= 16; word <<= 16; }
122 if (word & 0x00ff0000) { k -= 8; word <<= 8; }
123 if (word & 0x0f000000) { k -= 4; word <<= 4; }
124 if (word & 0x30000000) { k -= 2; word <<= 2; }
125 if (word & 0x40000000) { k -= 1; }
126 return k;
127 }
128
find_next_zero_bit(void * addr,int size,int offset)129 static inline int find_next_zero_bit(void *addr, int size, int offset)
130 {
131 unsigned long *p = ((unsigned long *)addr) + (offset >> 5);
132 unsigned long result = offset & ~31UL;
133 unsigned long tmp;
134
135 if (offset >= size)
136 return size;
137 size -= result;
138 offset &= 31UL;
139 if (offset) {
140 tmp = *(p++);
141 tmp |= ~0UL >> (32-offset);
142 if (size < 32)
143 goto found_first;
144 if (~tmp)
145 goto found_middle;
146 size -= 32;
147 result += 32;
148 }
149 while (size & ~31UL) {
150 tmp = *(p++);
151 if (~tmp)
152 goto found_middle;
153 result += 32;
154 size -= 32;
155 }
156 if (!size)
157 return result;
158 tmp = *p;
159
160 found_first:
161 tmp |= ~0UL << size;
162 found_middle:
163 return result + ffz(tmp);
164 }
165
166 /*
167 * hweightN: returns the hamming weight (i.e. the number
168 * of bits set) of a N-bit word
169 */
170
171 #define hweight32(x) generic_hweight32(x)
172 #define hweight16(x) generic_hweight16(x)
173 #define hweight8(x) generic_hweight8(x)
174
175 #define find_first_zero_bit(addr, size) \
176 find_next_zero_bit((addr), (size), 0)
177
178 #define ext2_set_bit test_and_set_bit
179 #define ext2_clear_bit test_and_clear_bit
180 #define ext2_test_bit test_bit
181 #define ext2_find_first_zero_bit find_first_zero_bit
182 #define ext2_find_next_zero_bit find_next_zero_bit
183
184 /* Bitmap functions for the minix filesystem. */
185 #define minix_test_and_set_bit(nr,addr) test_and_set_bit(nr,addr)
186 #define minix_set_bit(nr,addr) set_bit(nr,addr)
187 #define minix_test_and_clear_bit(nr,addr) test_and_clear_bit(nr,addr)
188 #define minix_test_bit(nr,addr) test_bit(nr,addr)
189 #define minix_find_first_zero_bit(addr,size) find_first_zero_bit(addr,size)
190
191 #endif /* __KERNEL__ */
192
193 #include <asm-generic/bitops/__fls.h>
194 #include <asm-generic/bitops/__ffs.h>
195 #include <asm-generic/bitops/fls.h>
196 #include <asm-generic/bitops/fls64.h>
197
198 #endif /* _ARM_BITOPS_H */
199