1 /* 2 * bitops.h: Bit string operations on the ppc 3 */ 4 5 #ifndef _PPC_BITOPS_H 6 #define _PPC_BITOPS_H 7 8 #include <asm/byteorder.h> 9 #include <asm-generic/bitops/__ffs.h> 10 11 /* 12 * Arguably these bit operations don't imply any memory barrier or 13 * SMP ordering, but in fact a lot of drivers expect them to imply 14 * both, since they do on x86 cpus. 15 */ 16 #ifdef CONFIG_SMP 17 #define SMP_WMB "eieio\n" 18 #define SMP_MB "\nsync" 19 #else 20 #define SMP_WMB 21 #define SMP_MB 22 #endif /* CONFIG_SMP */ 23 24 #define __INLINE_BITOPS 1 25 26 #if __INLINE_BITOPS 27 /* 28 * These used to be if'd out here because using : "cc" as a constraint 29 * resulted in errors from egcs. Things may be OK with gcc-2.95. 30 */ 31 static __inline__ void set_bit(int nr, volatile void * addr) 32 { 33 unsigned long old; 34 unsigned long mask = 1 << (nr & 0x1f); 35 unsigned long *p = ((unsigned long *)addr) + (nr >> 5); 36 37 __asm__ __volatile__(SMP_WMB "\ 38 1: lwarx %0,0,%3\n\ 39 or %0,%0,%2\n\ 40 stwcx. %0,0,%3\n\ 41 bne 1b" 42 SMP_MB 43 : "=&r" (old), "=m" (*p) 44 : "r" (mask), "r" (p), "m" (*p) 45 : "cc" ); 46 } 47 48 static __inline__ void clear_bit(int nr, volatile void *addr) 49 { 50 unsigned long old; 51 unsigned long mask = 1 << (nr & 0x1f); 52 unsigned long *p = ((unsigned long *)addr) + (nr >> 5); 53 54 __asm__ __volatile__(SMP_WMB "\ 55 1: lwarx %0,0,%3\n\ 56 andc %0,%0,%2\n\ 57 stwcx. %0,0,%3\n\ 58 bne 1b" 59 SMP_MB 60 : "=&r" (old), "=m" (*p) 61 : "r" (mask), "r" (p), "m" (*p) 62 : "cc"); 63 } 64 65 static __inline__ void change_bit(int nr, volatile void *addr) 66 { 67 unsigned long old; 68 unsigned long mask = 1 << (nr & 0x1f); 69 unsigned long *p = ((unsigned long *)addr) + (nr >> 5); 70 71 __asm__ __volatile__(SMP_WMB "\ 72 1: lwarx %0,0,%3\n\ 73 xor %0,%0,%2\n\ 74 stwcx. %0,0,%3\n\ 75 bne 1b" 76 SMP_MB 77 : "=&r" (old), "=m" (*p) 78 : "r" (mask), "r" (p), "m" (*p) 79 : "cc"); 80 } 81 82 static __inline__ int test_and_set_bit(int nr, volatile void *addr) 83 { 84 unsigned int old, t; 85 unsigned int mask = 1 << (nr & 0x1f); 86 volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5); 87 88 __asm__ __volatile__(SMP_WMB "\ 89 1: lwarx %0,0,%4\n\ 90 or %1,%0,%3\n\ 91 stwcx. %1,0,%4\n\ 92 bne 1b" 93 SMP_MB 94 : "=&r" (old), "=&r" (t), "=m" (*p) 95 : "r" (mask), "r" (p), "m" (*p) 96 : "cc"); 97 98 return (old & mask) != 0; 99 } 100 101 static __inline__ int test_and_clear_bit(int nr, volatile void *addr) 102 { 103 unsigned int old, t; 104 unsigned int mask = 1 << (nr & 0x1f); 105 volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5); 106 107 __asm__ __volatile__(SMP_WMB "\ 108 1: lwarx %0,0,%4\n\ 109 andc %1,%0,%3\n\ 110 stwcx. %1,0,%4\n\ 111 bne 1b" 112 SMP_MB 113 : "=&r" (old), "=&r" (t), "=m" (*p) 114 : "r" (mask), "r" (p), "m" (*p) 115 : "cc"); 116 117 return (old & mask) != 0; 118 } 119 120 static __inline__ int test_and_change_bit(int nr, volatile void *addr) 121 { 122 unsigned int old, t; 123 unsigned int mask = 1 << (nr & 0x1f); 124 volatile unsigned int *p = ((volatile unsigned int *)addr) + (nr >> 5); 125 126 __asm__ __volatile__(SMP_WMB "\ 127 1: lwarx %0,0,%4\n\ 128 xor %1,%0,%3\n\ 129 stwcx. %1,0,%4\n\ 130 bne 1b" 131 SMP_MB 132 : "=&r" (old), "=&r" (t), "=m" (*p) 133 : "r" (mask), "r" (p), "m" (*p) 134 : "cc"); 135 136 return (old & mask) != 0; 137 } 138 #endif /* __INLINE_BITOPS */ 139 140 static __inline__ int test_bit(int nr, __const__ volatile void *addr) 141 { 142 __const__ unsigned int *p = (__const__ unsigned int *) addr; 143 144 return ((p[nr >> 5] >> (nr & 0x1f)) & 1) != 0; 145 } 146 147 /* Return the bit position of the most significant 1 bit in a word */ 148 /* - the result is undefined when x == 0 */ 149 static __inline__ int __ilog2(unsigned int x) 150 { 151 int lz; 152 153 asm ("cntlzw %0,%1" : "=r" (lz) : "r" (x)); 154 return 31 - lz; 155 } 156 157 static __inline__ int ffz(unsigned int x) 158 { 159 if ((x = ~x) == 0) 160 return 32; 161 return __ilog2(x & -x); 162 } 163 164 /* 165 * fls: find last (most-significant) bit set. 166 * Note fls(0) = 0, fls(1) = 1, fls(0x80000000) = 32. 167 * 168 * On powerpc, __ilog2(0) returns -1, but this is not safe in general 169 */ 170 static __inline__ int fls(unsigned int x) 171 { 172 return __ilog2(x) + 1; 173 } 174 #define PLATFORM_FLS 175 176 /** 177 * fls64 - find last set bit in a 64-bit word 178 * @x: the word to search 179 * 180 * This is defined in a similar way as the libc and compiler builtin 181 * ffsll, but returns the position of the most significant set bit. 182 * 183 * fls64(value) returns 0 if value is 0 or the position of the last 184 * set bit if value is nonzero. The last (most significant) bit is 185 * at position 64. 186 */ 187 #if BITS_PER_LONG == 32 188 static inline int fls64(__u64 x) 189 { 190 __u32 h = x >> 32; 191 if (h) 192 return fls(h) + 32; 193 return fls(x); 194 } 195 #elif BITS_PER_LONG == 64 196 static inline int fls64(__u64 x) 197 { 198 if (x == 0) 199 return 0; 200 return __ilog2(x) + 1; 201 } 202 #else 203 #error BITS_PER_LONG not 32 or 64 204 #endif 205 206 #ifdef __KERNEL__ 207 208 /* 209 * ffs: find first bit set. This is defined the same way as 210 * the libc and compiler builtin ffs routines, therefore 211 * differs in spirit from the above ffz (man ffs). 212 */ 213 static __inline__ int ffs(int x) 214 { 215 return __ilog2(x & -x) + 1; 216 } 217 #define PLATFORM_FFS 218 219 /* 220 * hweightN: returns the hamming weight (i.e. the number 221 * of bits set) of a N-bit word 222 */ 223 224 #define hweight32(x) generic_hweight32(x) 225 #define hweight16(x) generic_hweight16(x) 226 #define hweight8(x) generic_hweight8(x) 227 228 #endif /* __KERNEL__ */ 229 230 /* 231 * This implementation of find_{first,next}_zero_bit was stolen from 232 * Linus' asm-alpha/bitops.h. 233 */ 234 #define find_first_zero_bit(addr, size) \ 235 find_next_zero_bit((addr), (size), 0) 236 237 static __inline__ unsigned long find_next_zero_bit(void * addr, 238 unsigned long size, unsigned long offset) 239 { 240 unsigned int * p = ((unsigned int *) addr) + (offset >> 5); 241 unsigned int result = offset & ~31UL; 242 unsigned int tmp; 243 244 if (offset >= size) 245 return size; 246 size -= result; 247 offset &= 31UL; 248 if (offset) { 249 tmp = *p++; 250 tmp |= ~0UL >> (32-offset); 251 if (size < 32) 252 goto found_first; 253 if (tmp != ~0U) 254 goto found_middle; 255 size -= 32; 256 result += 32; 257 } 258 while (size >= 32) { 259 if ((tmp = *p++) != ~0U) 260 goto found_middle; 261 result += 32; 262 size -= 32; 263 } 264 if (!size) 265 return result; 266 tmp = *p; 267 found_first: 268 tmp |= ~0UL << size; 269 found_middle: 270 return result + ffz(tmp); 271 } 272 273 274 #define _EXT2_HAVE_ASM_BITOPS_ 275 276 #ifdef __KERNEL__ 277 /* 278 * test_and_{set,clear}_bit guarantee atomicity without 279 * disabling interrupts. 280 */ 281 #define ext2_set_bit(nr, addr) test_and_set_bit((nr) ^ 0x18, addr) 282 #define ext2_clear_bit(nr, addr) test_and_clear_bit((nr) ^ 0x18, addr) 283 284 #else 285 static __inline__ int ext2_set_bit(int nr, void * addr) 286 { 287 int mask; 288 unsigned char *ADDR = (unsigned char *) addr; 289 int oldbit; 290 291 ADDR += nr >> 3; 292 mask = 1 << (nr & 0x07); 293 oldbit = (*ADDR & mask) ? 1 : 0; 294 *ADDR |= mask; 295 return oldbit; 296 } 297 298 static __inline__ int ext2_clear_bit(int nr, void * addr) 299 { 300 int mask; 301 unsigned char *ADDR = (unsigned char *) addr; 302 int oldbit; 303 304 ADDR += nr >> 3; 305 mask = 1 << (nr & 0x07); 306 oldbit = (*ADDR & mask) ? 1 : 0; 307 *ADDR = *ADDR & ~mask; 308 return oldbit; 309 } 310 #endif /* __KERNEL__ */ 311 312 static __inline__ int ext2_test_bit(int nr, __const__ void * addr) 313 { 314 __const__ unsigned char *ADDR = (__const__ unsigned char *) addr; 315 316 return (ADDR[nr >> 3] >> (nr & 7)) & 1; 317 } 318 319 /* 320 * This implementation of ext2_find_{first,next}_zero_bit was stolen from 321 * Linus' asm-alpha/bitops.h and modified for a big-endian machine. 322 */ 323 324 #define ext2_find_first_zero_bit(addr, size) \ 325 ext2_find_next_zero_bit((addr), (size), 0) 326 327 static __inline__ unsigned long ext2_find_next_zero_bit(void *addr, 328 unsigned long size, unsigned long offset) 329 { 330 unsigned int *p = ((unsigned int *) addr) + (offset >> 5); 331 unsigned int result = offset & ~31UL; 332 unsigned int tmp; 333 334 if (offset >= size) 335 return size; 336 size -= result; 337 offset &= 31UL; 338 if (offset) { 339 tmp = cpu_to_le32p(p++); 340 tmp |= ~0UL >> (32-offset); 341 if (size < 32) 342 goto found_first; 343 if (tmp != ~0U) 344 goto found_middle; 345 size -= 32; 346 result += 32; 347 } 348 while (size >= 32) { 349 if ((tmp = cpu_to_le32p(p++)) != ~0U) 350 goto found_middle; 351 result += 32; 352 size -= 32; 353 } 354 if (!size) 355 return result; 356 tmp = cpu_to_le32p(p); 357 found_first: 358 tmp |= ~0U << size; 359 found_middle: 360 return result + ffz(tmp); 361 } 362 363 /* Bitmap functions for the minix filesystem. */ 364 #define minix_test_and_set_bit(nr,addr) ext2_set_bit(nr,addr) 365 #define minix_set_bit(nr,addr) ((void)ext2_set_bit(nr,addr)) 366 #define minix_test_and_clear_bit(nr,addr) ext2_clear_bit(nr,addr) 367 #define minix_test_bit(nr,addr) ext2_test_bit(nr,addr) 368 #define minix_find_first_zero_bit(addr,size) ext2_find_first_zero_bit(addr,size) 369 370 #endif /* _PPC_BITOPS_H */ 371
