1 #ifndef _LINUX_BITOPS_H 2 #define _LINUX_BITOPS_H 3 4 #include <asm/types.h> 5 #include <asm-generic/bitsperlong.h> 6 #include <linux/compiler.h> 7 8 #ifdef __KERNEL__ 9 #define BIT(nr) (1UL << (nr)) 10 #define BIT_ULL(nr) (1ULL << (nr)) 11 #define BIT_MASK(nr) (1UL << ((nr) % BITS_PER_LONG)) 12 #define BIT_WORD(nr) ((nr) / BITS_PER_LONG) 13 #define BIT_ULL_MASK(nr) (1ULL << ((nr) % BITS_PER_LONG_LONG)) 14 #define BIT_ULL_WORD(nr) ((nr) / BITS_PER_LONG_LONG) 15 #define BITS_PER_BYTE 8 16 #define BITS_TO_LONGS(nr) DIV_ROUND_UP(nr, BITS_PER_BYTE * sizeof(long)) 17 #endif 18 19 /* 20 * Create a contiguous bitmask starting at bit position @l and ending at 21 * position @h. For example 22 * GENMASK_ULL(39, 21) gives us the 64bit vector 0x000000ffffe00000. 23 */ 24 #define GENMASK(h, l) \ 25 (((~0UL) << (l)) & (~0UL >> (BITS_PER_LONG - 1 - (h)))) 26 27 #define GENMASK_ULL(h, l) \ 28 (((~0ULL) << (l)) & (~0ULL >> (BITS_PER_LONG_LONG - 1 - (h)))) 29 30 /* 31 * ffs: find first bit set. This is defined the same way as 32 * the libc and compiler builtin ffs routines, therefore 33 * differs in spirit from the above ffz (man ffs). 34 */ 35 36 static inline int generic_ffs(int x) 37 { 38 int r = 1; 39 40 if (!x) 41 return 0; 42 if (!(x & 0xffff)) { 43 x >>= 16; 44 r += 16; 45 } 46 if (!(x & 0xff)) { 47 x >>= 8; 48 r += 8; 49 } 50 if (!(x & 0xf)) { 51 x >>= 4; 52 r += 4; 53 } 54 if (!(x & 3)) { 55 x >>= 2; 56 r += 2; 57 } 58 if (!(x & 1)) { 59 x >>= 1; 60 r += 1; 61 } 62 return r; 63 } 64 65 /** 66 * fls - find last (most-significant) bit set 67 * @x: the word to search 68 * 69 * This is defined the same way as ffs. 70 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. 71 */ 72 static inline int generic_fls(int x) 73 { 74 int r = 32; 75 76 if (!x) 77 return 0; 78 if (!(x & 0xffff0000u)) { 79 x <<= 16; 80 r -= 16; 81 } 82 if (!(x & 0xff000000u)) { 83 x <<= 8; 84 r -= 8; 85 } 86 if (!(x & 0xf0000000u)) { 87 x <<= 4; 88 r -= 4; 89 } 90 if (!(x & 0xc0000000u)) { 91 x <<= 2; 92 r -= 2; 93 } 94 if (!(x & 0x80000000u)) { 95 x <<= 1; 96 r -= 1; 97 } 98 return r; 99 } 100 101 102 /* 103 * hweightN: returns the hamming weight (i.e. the number 104 * of bits set) of a N-bit word 105 */ 106 107 static inline unsigned int generic_hweight32(unsigned int w) 108 { 109 unsigned int res = (w & 0x55555555) + ((w >> 1) & 0x55555555); 110 res = (res & 0x33333333) + ((res >> 2) & 0x33333333); 111 res = (res & 0x0F0F0F0F) + ((res >> 4) & 0x0F0F0F0F); 112 res = (res & 0x00FF00FF) + ((res >> 8) & 0x00FF00FF); 113 return (res & 0x0000FFFF) + ((res >> 16) & 0x0000FFFF); 114 } 115 116 static inline unsigned int generic_hweight16(unsigned int w) 117 { 118 unsigned int res = (w & 0x5555) + ((w >> 1) & 0x5555); 119 res = (res & 0x3333) + ((res >> 2) & 0x3333); 120 res = (res & 0x0F0F) + ((res >> 4) & 0x0F0F); 121 return (res & 0x00FF) + ((res >> 8) & 0x00FF); 122 } 123 124 static inline unsigned int generic_hweight8(unsigned int w) 125 { 126 unsigned int res = (w & 0x55) + ((w >> 1) & 0x55); 127 res = (res & 0x33) + ((res >> 2) & 0x33); 128 return (res & 0x0F) + ((res >> 4) & 0x0F); 129 } 130 131 #include <asm/bitops.h> 132 133 /* linux/include/asm-generic/bitops/non-atomic.h */ 134 135 #ifndef PLATFORM__SET_BIT 136 # define __set_bit generic_set_bit 137 #endif 138 139 #ifndef PLATFORM__CLEAR_BIT 140 # define __clear_bit generic_clear_bit 141 #endif 142 143 #ifndef PLATFORM_FFS 144 # define ffs generic_ffs 145 #endif 146 147 #ifndef PLATFORM_FLS 148 # define fls generic_fls 149 #endif 150 151 static inline unsigned fls_long(unsigned long l) 152 { 153 if (sizeof(l) == 4) 154 return fls(l); 155 return fls64(l); 156 } 157 158 /** 159 * __ffs64 - find first set bit in a 64 bit word 160 * @word: The 64 bit word 161 * 162 * On 64 bit arches this is a synomyn for __ffs 163 * The result is not defined if no bits are set, so check that @word 164 * is non-zero before calling this. 165 */ 166 static inline unsigned long __ffs64(u64 word) 167 { 168 #if BITS_PER_LONG == 32 169 if (((u32)word) == 0UL) 170 return __ffs((u32)(word >> 32)) + 32; 171 #elif BITS_PER_LONG != 64 172 #error BITS_PER_LONG not 32 or 64 173 #endif 174 return __ffs((unsigned long)word); 175 } 176 177 /** 178 * __set_bit - Set a bit in memory 179 * @nr: the bit to set 180 * @addr: the address to start counting from 181 * 182 * Unlike set_bit(), this function is non-atomic and may be reordered. 183 * If it's called on the same region of memory simultaneously, the effect 184 * may be that only one operation succeeds. 185 */ 186 static inline void generic_set_bit(int nr, volatile unsigned long *addr) 187 { 188 unsigned long mask = BIT_MASK(nr); 189 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 190 191 *p |= mask; 192 } 193 194 static inline void generic_clear_bit(int nr, volatile unsigned long *addr) 195 { 196 unsigned long mask = BIT_MASK(nr); 197 unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr); 198 199 *p &= ~mask; 200 } 201 202 #endif 203
