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 */ 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 static inline void __clear_bit(int nr, void *addr) 46 { 47 int *a = (int *)addr; 48 int mask; 49 50 a += nr >> 5; 51 mask = 1 << (nr & 0x1f); 52 *a &= ~mask; 53 } 54 55 static inline void __change_bit(int nr, void *addr) 56 { 57 int mask; 58 unsigned long *ADDR = (unsigned long *)addr; 59 60 ADDR += nr >> 5; 61 mask = 1 << (nr & 31); 62 *ADDR ^= mask; 63 } 64 65 static inline int __test_and_set_bit(int nr, void *addr) 66 { 67 int mask, retval; 68 unsigned int *a = (unsigned int *)addr; 69 70 a += nr >> 5; 71 mask = 1 << (nr & 0x1f); 72 retval = (mask & *a) != 0; 73 *a |= mask; 74 return retval; 75 } 76 77 static inline int __test_and_clear_bit(int nr, void *addr) 78 { 79 int mask, retval; 80 unsigned int *a = (unsigned int *)addr; 81 82 a += nr >> 5; 83 mask = 1 << (nr & 0x1f); 84 retval = (mask & *a) != 0; 85 *a &= ~mask; 86 return retval; 87 } 88 89 static inline int __test_and_change_bit(int nr, void *addr) 90 { 91 int mask, retval; 92 unsigned int *a = (unsigned int *)addr; 93 94 a += nr >> 5; 95 mask = 1 << (nr & 0x1f); 96 retval = (mask & *a) != 0; 97 *a ^= mask; 98 return retval; 99 } 100 101 /* 102 * This routine doesn't need to be atomic. 103 */ 104 static inline int test_bit(int nr, const void *addr) 105 { 106 return ((unsigned char *)addr)[nr >> 3] & (1U << (nr & 7)); 107 } 108 109 /* 110 * ffz = Find First Zero in word. Undefined if no zero exists, 111 * so code should check against ~0UL first.. 112 */ 113 static inline unsigned long ffz(unsigned long word) 114 { 115 int k; 116 117 word = ~word; 118 k = 31; 119 if (word & 0x0000ffff) { 120 k -= 16; word <<= 16; 121 } 122 if (word & 0x00ff0000) { 123 k -= 8; word <<= 8; 124 } 125 if (word & 0x0f000000) { 126 k -= 4; word <<= 4; 127 } 128 if (word & 0x30000000) { 129 k -= 2; word <<= 2; 130 } 131 if (word & 0x40000000) 132 k -= 1; 133 134 return k; 135 } 136 137 /* 138 * ffs: find first bit set. This is defined the same way as 139 * the libc and compiler builtin ffs routines, therefore 140 * differs in spirit from the above ffz (man ffs). 141 */ 142 143 /* 144 * redefined in include/linux/bitops.h 145 * #define ffs(x) generic_ffs(x) 146 */ 147 148 /* 149 * hweightN: returns the hamming weight (i.e. the number 150 * of bits set) of a N-bit word 151 */ 152 153 #define hweight32(x) generic_hweight32(x) 154 #define hweight16(x) generic_hweight16(x) 155 #define hweight8(x) generic_hweight8(x) 156 157 #define ext2_set_bit test_and_set_bit 158 #define ext2_clear_bit test_and_clear_bit 159 #define ext2_test_bit test_bit 160 #define ext2_find_first_zero_bit find_first_zero_bit 161 #define ext2_find_next_zero_bit find_next_zero_bit 162 163 /* Bitmap functions for the minix filesystem. */ 164 #define minix_test_and_set_bit(nr, addr) test_and_set_bit(nr, addr) 165 #define minix_set_bit(nr, addr) set_bit(nr, addr) 166 #define minix_test_and_clear_bit(nr, addr) test_and_clear_bit(nr, addr) 167 #define minix_test_bit(nr, addr) test_bit(nr, addr) 168 #define minix_find_first_zero_bit(addr, size) find_first_zero_bit(addr, size) 169 170 #endif /* __KERNEL__ */ 171 172 #endif /* __ASM_RISCV_BITOPS_H */ 173