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