arch/alpha/include/asm/bitops.h

   1 #ifndef _ALPHA_BITOPS_H
   2 #define _ALPHA_BITOPS_H
   3
   4 #ifndef _LINUX_BITOPS_H
   5 #error only <linux/bitops.h> can be included directly
   6 #endif
   7
   8 #include <asm/compiler.h>
   9 #include <asm/barrier.h>
  10
  11 /*
  12  * Copyright 1994, Linus Torvalds.
  13  */
  14
  15 /*
  16  * These have to be done with inline assembly: that way the bit-setting
  17  * is guaranteed to be atomic. All bit operations return 0 if the bit
  18  * was cleared before the operation and != 0 if it was not.
  19  *
  20  * To get proper branch prediction for the main line, we must branch
  21  * forward to code at the end of this object's .text section, then
  22  * branch back to restart the operation.
  23  *
  24  * bit 0 is the LSB of addr; bit 64 is the LSB of (addr+1).
  25  */
  26
  27 static inline void
  28 set_bit(unsigned long nr, volatile void * addr)
  29 {
  30         unsigned long temp;
  31         int *m = ((int *) addr) + (nr >> 5);
  32
  33         __asm__ __volatile__(
  34         "1:     ldl_l %0,%3\n"
  35         "       bis %0,%2,%0\n"
  36         "       stl_c %0,%1\n"
  37         "       beq %0,2f\n"
  38         ".subsection 2\n"
  39         "2:     br 1b\n"
  40         ".previous"
  41         :"=&r" (temp), "=m" (*m)
  42         :"Ir" (1UL << (nr & 31)), "m" (*m));
  43 }
  44
  45 /*
  46  * WARNING: non atomic version.
  47  */
  48 static inline void
  49 __set_bit(unsigned long nr, volatile void * addr)
  50 {
  51         int *m = ((int *) addr) + (nr >> 5);
  52
  53         *m |= 1 << (nr & 31);
  54 }
  55
  56 #define smp_mb__before_clear_bit()      smp_mb()
  57 #define smp_mb__after_clear_bit()       smp_mb()
  58
  59 static inline void
  60 clear_bit(unsigned long nr, volatile void * addr)
  61 {
  62         unsigned long temp;
  63         int *m = ((int *) addr) + (nr >> 5);
  64
  65         __asm__ __volatile__(
  66         "1:     ldl_l %0,%3\n"
  67         "       bic %0,%2,%0\n"
  68         "       stl_c %0,%1\n"
  69         "       beq %0,2f\n"
  70         ".subsection 2\n"
  71         "2:     br 1b\n"
  72         ".previous"
  73         :"=&r" (temp), "=m" (*m)
  74         :"Ir" (1UL << (nr & 31)), "m" (*m));
  75 }
  76
  77 static inline void
  78 clear_bit_unlock(unsigned long nr, volatile void * addr)
  79 {
  80         smp_mb();
  81         clear_bit(nr, addr);
  82 }
  83
  84 /*
  85  * WARNING: non atomic version.
  86  */
  87 static __inline__ void
  88 __clear_bit(unsigned long nr, volatile void * addr)
  89 {
  90         int *m = ((int *) addr) + (nr >> 5);
  91
  92         *m &= ~(1 << (nr & 31));
  93 }
  94
  95 static inline void
  96 __clear_bit_unlock(unsigned long nr, volatile void * addr)
  97 {
  98         smp_mb();
  99         __clear_bit(nr, addr);
 100 }
 101
 102 static inline void
 103 change_bit(unsigned long nr, volatile void * addr)
 104 {
 105         unsigned long temp;
 106         int *m = ((int *) addr) + (nr >> 5);
 107
 108         __asm__ __volatile__(
 109         "1:     ldl_l %0,%3\n"
 110         "       xor %0,%2,%0\n"
 111         "       stl_c %0,%1\n"
 112         "       beq %0,2f\n"
 113         ".subsection 2\n"
 114         "2:     br 1b\n"
 115         ".previous"
 116         :"=&r" (temp), "=m" (*m)
 117         :"Ir" (1UL << (nr & 31)), "m" (*m));
 118 }
 119
 120 /*
 121  * WARNING: non atomic version.
 122  */
 123 static __inline__ void
 124 __change_bit(unsigned long nr, volatile void * addr)
 125 {
 126         int *m = ((int *) addr) + (nr >> 5);
 127
 128         *m ^= 1 << (nr & 31);
 129 }
 130
 131 static inline int
 132 test_and_set_bit(unsigned long nr, volatile void *addr)
 133 {
 134         unsigned long oldbit;
 135         unsigned long temp;
 136         int *m = ((int *) addr) + (nr >> 5);
 137
 138         __asm__ __volatile__(
 139 #ifdef CONFIG_SMP
 140         "       mb\n"
 141 #endif
 142         "1:     ldl_l %0,%4\n"
 143         "       and %0,%3,%2\n"
 144         "       bne %2,2f\n"
 145         "       xor %0,%3,%0\n"
 146         "       stl_c %0,%1\n"
 147         "       beq %0,3f\n"
 148         "2:\n"
 149 #ifdef CONFIG_SMP
 150         "       mb\n"
 151 #endif
 152         ".subsection 2\n"
 153         "3:     br 1b\n"
 154         ".previous"
 155         :"=&r" (temp), "=m" (*m), "=&r" (oldbit)
 156         :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory");
 157
 158         return oldbit != 0;
 159 }
 160
 161 static inline int
 162 test_and_set_bit_lock(unsigned long nr, volatile void *addr)
 163 {
 164         unsigned long oldbit;
 165         unsigned long temp;
 166         int *m = ((int *) addr) + (nr >> 5);
 167
 168         __asm__ __volatile__(
 169         "1:     ldl_l %0,%4\n"
 170         "       and %0,%3,%2\n"
 171         "       bne %2,2f\n"
 172         "       xor %0,%3,%0\n"
 173         "       stl_c %0,%1\n"
 174         "       beq %0,3f\n"
 175         "2:\n"
 176 #ifdef CONFIG_SMP
 177         "       mb\n"
 178 #endif
 179         ".subsection 2\n"
 180         "3:     br 1b\n"
 181         ".previous"
 182         :"=&r" (temp), "=m" (*m), "=&r" (oldbit)
 183         :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory");
 184
 185         return oldbit != 0;
 186 }
 187
 188 /*
 189  * WARNING: non atomic version.
 190  */
 191 static inline int
 192 __test_and_set_bit(unsigned long nr, volatile void * addr)
 193 {
 194         unsigned long mask = 1 << (nr & 0x1f);
 195         int *m = ((int *) addr) + (nr >> 5);
 196         int old = *m;
 197
 198         *m = old | mask;
 199         return (old & mask) != 0;
 200 }
 201
 202 static inline int
 203 test_and_clear_bit(unsigned long nr, volatile void * addr)
 204 {
 205         unsigned long oldbit;
 206         unsigned long temp;
 207         int *m = ((int *) addr) + (nr >> 5);
 208
 209         __asm__ __volatile__(
 210 #ifdef CONFIG_SMP
 211         "       mb\n"
 212 #endif
 213         "1:     ldl_l %0,%4\n"
 214         "       and %0,%3,%2\n"
 215         "       beq %2,2f\n"
 216         "       xor %0,%3,%0\n"
 217         "       stl_c %0,%1\n"
 218         "       beq %0,3f\n"
 219         "2:\n"
 220 #ifdef CONFIG_SMP
 221         "       mb\n"
 222 #endif
 223         ".subsection 2\n"
 224         "3:     br 1b\n"
 225         ".previous"
 226         :"=&r" (temp), "=m" (*m), "=&r" (oldbit)
 227         :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory");
 228
 229         return oldbit != 0;
 230 }
 231
 232 /*
 233  * WARNING: non atomic version.
 234  */
 235 static inline int
 236 __test_and_clear_bit(unsigned long nr, volatile void * addr)
 237 {
 238         unsigned long mask = 1 << (nr & 0x1f);
 239         int *m = ((int *) addr) + (nr >> 5);
 240         int old = *m;
 241
 242         *m = old & ~mask;
 243         return (old & mask) != 0;
 244 }
 245
 246 static inline int
 247 test_and_change_bit(unsigned long nr, volatile void * addr)
 248 {
 249         unsigned long oldbit;
 250         unsigned long temp;
 251         int *m = ((int *) addr) + (nr >> 5);
 252
 253         __asm__ __volatile__(
 254 #ifdef CONFIG_SMP
 255         "       mb\n"
 256 #endif
 257         "1:     ldl_l %0,%4\n"
 258         "       and %0,%3,%2\n"
 259         "       xor %0,%3,%0\n"
 260         "       stl_c %0,%1\n"
 261         "       beq %0,3f\n"
 262 #ifdef CONFIG_SMP
 263         "       mb\n"
 264 #endif
 265         ".subsection 2\n"
 266         "3:     br 1b\n"
 267         ".previous"
 268         :"=&r" (temp), "=m" (*m), "=&r" (oldbit)
 269         :"Ir" (1UL << (nr & 31)), "m" (*m) : "memory");
 270
 271         return oldbit != 0;
 272 }
 273
 274 /*
 275  * WARNING: non atomic version.
 276  */
 277 static __inline__ int
 278 __test_and_change_bit(unsigned long nr, volatile void * addr)
 279 {
 280         unsigned long mask = 1 << (nr & 0x1f);
 281         int *m = ((int *) addr) + (nr >> 5);
 282         int old = *m;
 283
 284         *m = old ^ mask;
 285         return (old & mask) != 0;
 286 }
 287
 288 static inline int
 289 test_bit(int nr, const volatile void * addr)
 290 {
 291         return (1UL & (((const int *) addr)[nr >> 5] >> (nr & 31))) != 0UL;
 292 }
 293
 294 /*
 295  * ffz = Find First Zero in word. Undefined if no zero exists,
 296  * so code should check against ~0UL first..
 297  *
 298  * Do a binary search on the bits.  Due to the nature of large
 299  * constants on the alpha, it is worthwhile to split the search.
 300  */
 301 static inline unsigned long ffz_b(unsigned long x)
 302 {
 303         unsigned long sum, x1, x2, x4;
 304
 305         x = ~x & -~x;           /* set first 0 bit, clear others */
 306         x1 = x & 0xAA;
 307         x2 = x & 0xCC;
 308         x4 = x & 0xF0;
 309         sum = x2 ? 2 : 0;
 310         sum += (x4 != 0) * 4;
 311         sum += (x1 != 0);
 312
 313         return sum;
 314 }
 315
 316 static inline unsigned long ffz(unsigned long word)
 317 {
 318 #if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
 319         /* Whee.  EV67 can calculate it directly.  */
 320         return __kernel_cttz(~word);
 321 #else
 322         unsigned long bits, qofs, bofs;
 323
 324         bits = __kernel_cmpbge(word, ~0UL);
 325         qofs = ffz_b(bits);
 326         bits = __kernel_extbl(word, qofs);
 327         bofs = ffz_b(bits);
 328
 329         return qofs*8 + bofs;
 330 #endif
 331 }
 332
 333 /*
 334  * __ffs = Find First set bit in word.  Undefined if no set bit exists.
 335  */
 336 static inline unsigned long __ffs(unsigned long word)
 337 {
 338 #if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
 339         /* Whee.  EV67 can calculate it directly.  */
 340         return __kernel_cttz(word);
 341 #else
 342         unsigned long bits, qofs, bofs;
 343
 344         bits = __kernel_cmpbge(0, word);
 345         qofs = ffz_b(bits);
 346         bits = __kernel_extbl(word, qofs);
 347         bofs = ffz_b(~bits);
 348
 349         return qofs*8 + bofs;
 350 #endif
 351 }
 352
 353 #ifdef __KERNEL__
 354
 355 /*
 356  * ffs: find first bit set. This is defined the same way as
 357  * the libc and compiler builtin ffs routines, therefore
 358  * differs in spirit from the above __ffs.
 359  */
 360
 361 static inline int ffs(int word)
 362 {
 363         int result = __ffs(word) + 1;
 364         return word ? result : 0;
 365 }
 366
 367 /*
 368  * fls: find last bit set.
 369  */
 370 #if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
 371 static inline int fls64(unsigned long word)
 372 {
 373         return 64 - __kernel_ctlz(word);
 374 }
 375 #else
 376 extern const unsigned char __flsm1_tab[256];
 377
 378 static inline int fls64(unsigned long x)
 379 {
 380         unsigned long t, a, r;
 381
 382         t = __kernel_cmpbge (x, 0x0101010101010101UL);
 383         a = __flsm1_tab[t];
 384         t = __kernel_extbl (x, a);
 385         r = a*8 + __flsm1_tab[t] + (x != 0);
 386
 387         return r;
 388 }
 389 #endif
 390
 391 static inline unsigned long __fls(unsigned long x)
 392 {
 393         return fls64(x) - 1;
 394 }
 395
 396 static inline int fls(int x)
 397 {
 398         return fls64((unsigned int) x);
 399 }
 400
 401 /*
 402  * hweightN: returns the hamming weight (i.e. the number
 403  * of bits set) of a N-bit word
 404  */
 405
 406 #if defined(CONFIG_ALPHA_EV6) && defined(CONFIG_ALPHA_EV67)
 407 /* Whee.  EV67 can calculate it directly.  */
 408 static inline unsigned long hweight64(unsigned long w)
 409 {
 410         return __kernel_ctpop(w);
 411 }
 412
 413 static inline unsigned int hweight32(unsigned int w)
 414 {
 415         return hweight64(w);
 416 }
 417
 418 static inline unsigned int hweight16(unsigned int w)
 419 {
 420         return hweight64(w & 0xffff);
 421 }
 422
 423 static inline unsigned int hweight8(unsigned int w)
 424 {
 425         return hweight64(w & 0xff);
 426 }
 427 #else
 428 #include <asm-generic/bitops/hweight.h>
 429 #endif
 430
 431 #endif /* __KERNEL__ */
 432
 433 #include <asm-generic/bitops/find.h>
 434
 435 #ifdef __KERNEL__
 436
 437 /*
 438  * Every architecture must define this function. It's the fastest
 439  * way of searching a 140-bit bitmap where the first 100 bits are
 440  * unlikely to be set. It's guaranteed that at least one of the 140
 441  * bits is set.
 442  */
 443 static inline unsigned long
 444 sched_find_first_bit(unsigned long b[3])
 445 {
 446         unsigned long b0 = b[0], b1 = b[1], b2 = b[2];
 447         unsigned long ofs;
 448
 449         ofs = (b1 ? 64 : 128);
 450         b1 = (b1 ? b1 : b2);
 451         ofs = (b0 ? 0 : ofs);
 452         b0 = (b0 ? b0 : b1);
 453
 454         return __ffs(b0) + ofs;
 455 }
 456
 457 #include <asm-generic/bitops/ext2-non-atomic.h>
 458
 459 #define ext2_set_bit_atomic(l,n,a)   test_and_set_bit(n,a)
 460 #define ext2_clear_bit_atomic(l,n,a) test_and_clear_bit(n,a)
 461
 462 #include <asm-generic/bitops/minix.h>
 463
 464 #endif /* __KERNEL__ */
 465
 466 #endif /* _ALPHA_BITOPS_H */