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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