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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 | /* * $Id: bitops.h,v 1.11 1999/01/03 20:16:48 cort Exp $ * bitops.h: Bit string operations on the ppc */ #ifndef _PPC_BITOPS_H #define _PPC_BITOPS_H #include <asm/system.h> #include <asm/byteorder.h> extern void set_bit(int nr, volatile void *addr); extern void clear_bit(int nr, volatile void *addr); extern void change_bit(int nr, volatile void *addr); extern int test_and_set_bit(int nr, volatile void *addr); extern int test_and_clear_bit(int nr, volatile void *addr); extern int test_and_change_bit(int nr, volatile void *addr); /* Returns the number of 0's to the left of the most significant 1 bit */ extern __inline__ int cntlzw(int bits) { int lz; asm ("cntlzw %0,%1" : "=r" (lz) : "r" (bits)); return lz; } /* * These are if'd out here because using : "cc" as a constraint * results in errors from gcc. -- Cort * Besides, they need to be changed so we have both set_bit * and test_and_set_bit, etc. */ #if 0 extern __inline__ int set_bit(int nr, void * addr) { unsigned long old, t; unsigned long mask = 1 << (nr & 0x1f); unsigned long *p = ((unsigned long *)addr) + (nr >> 5); __asm__ __volatile__( "1:lwarx %0,0,%3 \n\t" "or %1,%0,%2 \n\t" "stwcx. %1,0,%3 \n\t" "bne 1b \n\t" : "=&r" (old), "=&r" (t) /*, "=m" (*p)*/ : "r" (mask), "r" (p) /*: "cc" */); return (old & mask) != 0; } extern __inline__ unsigned long clear_bit(unsigned long nr, void *addr) { unsigned long old, t; unsigned long mask = 1 << (nr & 0x1f); unsigned long *p = ((unsigned long *)addr) + (nr >> 5); __asm__ __volatile__("\n\ 1: lwarx %0,0,%3 andc %1,%0,%2 stwcx. %1,0,%3 bne 1b" : "=&r" (old), "=&r" (t) /*, "=m" (*p)*/ : "r" (mask), "r" (p) /*: "cc"*/); return (old & mask) != 0; } extern __inline__ unsigned long change_bit(unsigned long nr, void *addr) { unsigned long old, t; unsigned long mask = 1 << (nr & 0x1f); unsigned long *p = ((unsigned long *)addr) + (nr >> 5); __asm__ __volatile__("\n\ 1: lwarx %0,0,%3 xor %1,%0,%2 stwcx. %1,0,%3 bne 1b" : "=&r" (old), "=&r" (t) /*, "=m" (*p)*/ : "r" (mask), "r" (p) /*: "cc"*/); return (old & mask) != 0; } #endif extern __inline__ unsigned long test_bit(int nr, __const__ volatile void *addr) { __const__ unsigned int *p = (__const__ unsigned int *) addr; return (p[nr >> 5] >> (nr & 0x1f)) & 1UL; } extern __inline__ int ffz(unsigned int x) { int n; if (x == ~0) return 32; x = ~x & (x+1); /* set LS zero to 1, other bits to 0 */ __asm__ ("cntlzw %0,%1" : "=r" (n) : "r" (x)); return 31 - n; } #ifdef __KERNEL__ /* * ffs: find first bit set. This is defined the same way as * the libc and compiler builtin ffs routines, therefore * differs in spirit from the above ffz (man ffs). */ #define ffs(x) generic_ffs(x) #if 0 /* untested, someone with PPC knowledge? */ /* From Alexander Kjeldaas <astor@guardian.no> */ extern __inline__ int ffs(int x) { int result; asm ("cntlzw %0,%1" : "=r" (result) : "r" (x)); return 32 - result; /* IBM backwards ordering of bits */ } #endif /* * hweightN: returns the hamming weight (i.e. the number * of bits set) of a N-bit word */ #define hweight32(x) generic_hweight32(x) #define hweight16(x) generic_hweight16(x) #define hweight8(x) generic_hweight8(x) #endif /* __KERNEL__ */ /* * This implementation of find_{first,next}_zero_bit was stolen from * Linus' asm-alpha/bitops.h. */ #define find_first_zero_bit(addr, size) \ find_next_zero_bit((addr), (size), 0) extern __inline__ unsigned long find_next_zero_bit(void * addr, unsigned long size, unsigned long offset) { unsigned int * p = ((unsigned int *) addr) + (offset >> 5); unsigned int result = offset & ~31UL; unsigned int tmp; if (offset >= size) return size; size -= result; offset &= 31UL; if (offset) { tmp = *p++; tmp |= ~0UL >> (32-offset); if (size < 32) goto found_first; if (tmp != ~0U) goto found_middle; size -= 32; result += 32; } while (size >= 32) { if ((tmp = *p++) != ~0U) goto found_middle; result += 32; size -= 32; } if (!size) return result; tmp = *p; found_first: tmp |= ~0UL << size; found_middle: return result + ffz(tmp); } #define _EXT2_HAVE_ASM_BITOPS_ #ifdef __KERNEL__ /* * test_and_{set,clear}_bit guarantee atomicity without * disabling interrupts. */ #define ext2_set_bit(nr, addr) test_and_set_bit((nr) ^ 0x18, addr) #define ext2_clear_bit(nr, addr) test_and_clear_bit((nr) ^ 0x18, addr) #else extern __inline__ int ext2_set_bit(int nr, void * addr) { int mask; unsigned char *ADDR = (unsigned char *) addr; int oldbit; ADDR += nr >> 3; mask = 1 << (nr & 0x07); oldbit = (*ADDR & mask) ? 1 : 0; *ADDR |= mask; return oldbit; } extern __inline__ int ext2_clear_bit(int nr, void * addr) { int mask; unsigned char *ADDR = (unsigned char *) addr; int oldbit; ADDR += nr >> 3; mask = 1 << (nr & 0x07); oldbit = (*ADDR & mask) ? 1 : 0; *ADDR = *ADDR & ~mask; return oldbit; } #endif /* __KERNEL__ */ extern __inline__ int ext2_test_bit(int nr, __const__ void * addr) { __const__ unsigned char *ADDR = (__const__ unsigned char *) addr; return (ADDR[nr >> 3] >> (nr & 7)) & 1; } /* * This implementation of ext2_find_{first,next}_zero_bit was stolen from * Linus' asm-alpha/bitops.h and modified for a big-endian machine. */ #define ext2_find_first_zero_bit(addr, size) \ ext2_find_next_zero_bit((addr), (size), 0) extern __inline__ unsigned long ext2_find_next_zero_bit(void *addr, unsigned long size, unsigned long offset) { unsigned int *p = ((unsigned int *) addr) + (offset >> 5); unsigned int result = offset & ~31UL; unsigned int tmp; if (offset >= size) return size; size -= result; offset &= 31UL; if (offset) { tmp = cpu_to_le32p(p++); tmp |= ~0UL >> (32-offset); if (size < 32) goto found_first; if (tmp != ~0U) goto found_middle; size -= 32; result += 32; } while (size >= 32) { if ((tmp = cpu_to_le32p(p++)) != ~0U) goto found_middle; result += 32; size -= 32; } if (!size) return result; tmp = cpu_to_le32p(p); found_first: tmp |= ~0U << size; found_middle: return result + ffz(tmp); } /* Bitmap functions for the minix filesystem. */ #define minix_set_bit(nr,addr) ext2_set_bit(nr,addr) #define minix_clear_bit(nr,addr) ext2_clear_bit(nr,addr) #define minix_test_bit(nr,addr) ext2_test_bit(nr,addr) #define minix_find_first_zero_bit(addr,size) ext2_find_first_zero_bit(addr,size) #endif /* _PPC_BITOPS_H */ |