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 static inline void __change_bit(int nr, void *addr) 58 { 59 int mask; 60 unsigned long *ADDR = (unsigned long *)addr; 61 62 ADDR += nr >> 5; 63 mask = 1 << (nr & 31); 64 *ADDR ^= mask; 65 } 66 67 static inline int __test_and_set_bit(int nr, void *addr) 68 { 69 int mask, retval; 70 unsigned int *a = (unsigned int *)addr; 71 72 a += nr >> 5; 73 mask = 1 << (nr & 0x1f); 74 retval = (mask & *a) != 0; 75 *a |= mask; 76 return retval; 77 } 78 79 static inline int __test_and_clear_bit(int nr, void *addr) 80 { 81 int mask, retval; 82 unsigned int *a = (unsigned int *)addr; 83 84 a += nr >> 5; 85 mask = 1 << (nr & 0x1f); 86 retval = (mask & *a) != 0; 87 *a &= ~mask; 88 return retval; 89 } 90 91 static inline int __test_and_change_bit(int nr, void *addr) 92 { 93 int mask, retval; 94 unsigned int *a = (unsigned int *)addr; 95 96 a += nr >> 5; 97 mask = 1 << (nr & 0x1f); 98 retval = (mask & *a) != 0; 99 *a ^= mask; 100 return retval; 101 } 102 103 /* 104 * This routine doesn't need to be atomic. 105 */ 106 static inline int test_bit(int nr, const void *addr) 107 { 108 return ((unsigned char *)addr)[nr >> 3] & (1U << (nr & 7)); 109 } 110 111 /* 112 * ffz = Find First Zero in word. Undefined if no zero exists, 113 * so code should check against ~0UL first.. 114 */ 115 static inline unsigned long ffz(unsigned long word) 116 { 117 int k; 118 119 word = ~word; 120 k = 31; 121 if (word & 0x0000ffff) { 122 k -= 16; word <<= 16; 123 } 124 if (word & 0x00ff0000) { 125 k -= 8; word <<= 8; 126 } 127 if (word & 0x0f000000) { 128 k -= 4; word <<= 4; 129 } 130 if (word & 0x30000000) { 131 k -= 2; word <<= 2; 132 } 133 if (word & 0x40000000) 134 k -= 1; 135 136 return k; 137 } 138 139 /* 140 * ffs: find first bit set. This is defined the same way as 141 * the libc and compiler builtin ffs routines, therefore 142 * differs in spirit from the above ffz (man ffs). 143 */ 144 145 /* 146 * redefined in include/linux/bitops.h 147 * #define ffs(x) generic_ffs(x) 148 */ 149 150 /* 151 * hweightN: returns the hamming weight (i.e. the number 152 * of bits set) of a N-bit word 153 */ 154 155 #define hweight32(x) generic_hweight32(x) 156 #define hweight16(x) generic_hweight16(x) 157 #define hweight8(x) generic_hweight8(x) 158 159 #define ext2_set_bit test_and_set_bit 160 #define ext2_clear_bit test_and_clear_bit 161 #define ext2_test_bit test_bit 162 #define ext2_find_first_zero_bit find_first_zero_bit 163 #define ext2_find_next_zero_bit find_next_zero_bit 164 165 /* Bitmap functions for the minix filesystem. */ 166 #define minix_test_and_set_bit(nr, addr) test_and_set_bit(nr, addr) 167 #define minix_set_bit(nr, addr) set_bit(nr, addr) 168 #define minix_test_and_clear_bit(nr, addr) test_and_clear_bit(nr, addr) 169 #define minix_test_bit(nr, addr) test_bit(nr, addr) 170 #define minix_find_first_zero_bit(addr, size) find_first_zero_bit(addr, size) 171 172 #endif /* __KERNEL__ */ 173 174 #endif /* __ASM_RISCV_BITOPS_H */ 175