1 /*
2 * Copyright 1995, Russell King.
3 * Various bits and pieces copyrights include:
4 * Linus Torvalds (test_bit).
5 *
6 * Copyright (C) 2017 Andes Technology Corporation
7 * Rick Chen, Andes Technology Corporation <rick@andestech.com>
8 *
9 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
10 *
11 * Please note that the code in this file should never be included
12 * from user space. Many of these are not implemented in assembler
13 * since they would be too costly. Also, they require priviledged
14 * instructions (which are not available from user mode) to ensure
15 * that they are atomic.
16 */
17
18 #ifndef __ASM_RISCV_BITOPS_H
19 #define __ASM_RISCV_BITOPS_H
20
21 #ifdef __KERNEL__
22
23 #include <asm/system.h>
24 #include <asm-generic/bitops/fls.h>
25 #include <asm-generic/bitops/__fls.h>
26 #include <asm-generic/bitops/fls64.h>
27 #include <asm-generic/bitops/__ffs.h>
28
29 #define smp_mb__before_clear_bit() do { } while (0)
30 #define smp_mb__after_clear_bit() do { } while (0)
31
32 /*
33 * Function prototypes to keep gcc -Wall happy.
34 */
__set_bit(int nr,void * addr)35 static inline void __set_bit(int nr, void *addr)
36 {
37 int *a = (int *)addr;
38 int mask;
39
40 a += nr >> 5;
41 mask = 1 << (nr & 0x1f);
42 *a |= mask;
43 }
44
45 #define PLATFORM__SET_BIT
46
__clear_bit(int nr,void * addr)47 static inline void __clear_bit(int nr, void *addr)
48 {
49 int *a = (int *)addr;
50 int mask;
51
52 a += nr >> 5;
53 mask = 1 << (nr & 0x1f);
54 *a &= ~mask;
55 }
56
57 #define PLATFORM__CLEAR_BIT
58
__change_bit(int nr,void * addr)59 static inline void __change_bit(int nr, void *addr)
60 {
61 int mask;
62 unsigned long *ADDR = (unsigned long *)addr;
63
64 ADDR += nr >> 5;
65 mask = 1 << (nr & 31);
66 *ADDR ^= mask;
67 }
68
__test_and_set_bit(int nr,void * addr)69 static inline int __test_and_set_bit(int nr, void *addr)
70 {
71 int mask, retval;
72 unsigned int *a = (unsigned int *)addr;
73
74 a += nr >> 5;
75 mask = 1 << (nr & 0x1f);
76 retval = (mask & *a) != 0;
77 *a |= mask;
78 return retval;
79 }
80
__test_and_clear_bit(int nr,void * addr)81 static inline int __test_and_clear_bit(int nr, void *addr)
82 {
83 int mask, retval;
84 unsigned int *a = (unsigned int *)addr;
85
86 a += nr >> 5;
87 mask = 1 << (nr & 0x1f);
88 retval = (mask & *a) != 0;
89 *a &= ~mask;
90 return retval;
91 }
92
__test_and_change_bit(int nr,void * addr)93 static inline int __test_and_change_bit(int nr, void *addr)
94 {
95 int mask, retval;
96 unsigned int *a = (unsigned int *)addr;
97
98 a += nr >> 5;
99 mask = 1 << (nr & 0x1f);
100 retval = (mask & *a) != 0;
101 *a ^= mask;
102 return retval;
103 }
104
105 /*
106 * This routine doesn't need to be atomic.
107 */
test_bit(int nr,const void * addr)108 static inline int test_bit(int nr, const void *addr)
109 {
110 return ((unsigned char *)addr)[nr >> 3] & (1U << (nr & 7));
111 }
112
113 /*
114 * ffz = Find First Zero in word. Undefined if no zero exists,
115 * so code should check against ~0UL first..
116 */
ffz(unsigned long word)117 static inline unsigned long ffz(unsigned long word)
118 {
119 int k;
120
121 word = ~word;
122 k = 31;
123 if (word & 0x0000ffff) {
124 k -= 16; word <<= 16;
125 }
126 if (word & 0x00ff0000) {
127 k -= 8; word <<= 8;
128 }
129 if (word & 0x0f000000) {
130 k -= 4; word <<= 4;
131 }
132 if (word & 0x30000000) {
133 k -= 2; word <<= 2;
134 }
135 if (word & 0x40000000)
136 k -= 1;
137
138 return k;
139 }
140
141 /*
142 * ffs: find first bit set. This is defined the same way as
143 * the libc and compiler builtin ffs routines, therefore
144 * differs in spirit from the above ffz (man ffs).
145 */
146
147 /*
148 * redefined in include/linux/bitops.h
149 * #define ffs(x) generic_ffs(x)
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 ext2_set_bit test_and_set_bit
162 #define ext2_clear_bit test_and_clear_bit
163 #define ext2_test_bit test_bit
164 #define ext2_find_first_zero_bit find_first_zero_bit
165 #define ext2_find_next_zero_bit find_next_zero_bit
166
167 /* Bitmap functions for the minix filesystem. */
168 #define minix_test_and_set_bit(nr, addr) test_and_set_bit(nr, addr)
169 #define minix_set_bit(nr, addr) set_bit(nr, addr)
170 #define minix_test_and_clear_bit(nr, addr) test_and_clear_bit(nr, addr)
171 #define minix_test_bit(nr, addr) test_bit(nr, addr)
172 #define minix_find_first_zero_bit(addr, size) find_first_zero_bit(addr, size)
173
174 #endif /* __KERNEL__ */
175
176 #endif /* __ASM_RISCV_BITOPS_H */
177