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 #define PLATFORM__SET_BIT 46 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 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 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 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 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 */ 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 */ 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