include/asm-ia64/bitops.h

   1 #ifndef _ASM_IA64_BITOPS_H
   2 #define _ASM_IA64_BITOPS_H
   3
   4 /*
   5  * Copyright (C) 1998-2003 Hewlett-Packard Co
   6  *      David Mosberger-Tang <davidm@hpl.hp.com>
   7  *
   8  * 02/06/02 find_next_bit() and find_first_bit() added from Erich Focht's ia64
   9  * O(1) scheduler patch
  10  */
  11
  12 #ifndef _LINUX_BITOPS_H
  13 #error only <linux/bitops.h> can be included directly
  14 #endif
  15
  16 #include <linux/compiler.h>
  17 #include <linux/types.h>
  18 #include <asm/intrinsics.h>
  19
  20 /**
  21  * set_bit - Atomically set a bit in memory
  22  * @nr: the bit to set
  23  * @addr: the address to start counting from
  24  *
  25  * This function is atomic and may not be reordered.  See __set_bit()
  26  * if you do not require the atomic guarantees.
  27  * Note that @nr may be almost arbitrarily large; this function is not
  28  * restricted to acting on a single-word quantity.
  29  *
  30  * The address must be (at least) "long" aligned.
  31  * Note that there are driver (e.g., eepro100) which use these operations to
  32  * operate on hw-defined data-structures, so we can't easily change these
  33  * operations to force a bigger alignment.
  34  *
  35  * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
  36  */
  37 static __inline__ void
  38 set_bit (int nr, volatile void *addr)
  39 {
  40         __u32 bit, old, new;
  41         volatile __u32 *m;
  42         CMPXCHG_BUGCHECK_DECL
  43
  44         m = (volatile __u32 *) addr + (nr >> 5);
  45         bit = 1 << (nr & 31);
  46         do {
  47                 CMPXCHG_BUGCHECK(m);
  48                 old = *m;
  49                 new = old | bit;
  50         } while (cmpxchg_acq(m, old, new) != old);
  51 }
  52
  53 /**
  54  * __set_bit - Set a bit in memory
  55  * @nr: the bit to set
  56  * @addr: the address to start counting from
  57  *
  58  * Unlike set_bit(), this function is non-atomic and may be reordered.
  59  * If it's called on the same region of memory simultaneously, the effect
  60  * may be that only one operation succeeds.
  61  */
  62 static __inline__ void
  63 __set_bit (int nr, volatile void *addr)
  64 {
  65         *((__u32 *) addr + (nr >> 5)) |= (1 << (nr & 31));
  66 }
  67
  68 /*
  69  * clear_bit() has "acquire" semantics.
  70  */
  71 #define smp_mb__before_clear_bit()      smp_mb()
  72 #define smp_mb__after_clear_bit()       do { /* skip */; } while (0)
  73
  74 /**
  75  * clear_bit - Clears a bit in memory
  76  * @nr: Bit to clear
  77  * @addr: Address to start counting from
  78  *
  79  * clear_bit() is atomic and may not be reordered.  However, it does
  80  * not contain a memory barrier, so if it is used for locking purposes,
  81  * you should call smp_mb__before_clear_bit() and/or smp_mb__after_clear_bit()
  82  * in order to ensure changes are visible on other processors.
  83  */
  84 static __inline__ void
  85 clear_bit (int nr, volatile void *addr)
  86 {
  87         __u32 mask, old, new;
  88         volatile __u32 *m;
  89         CMPXCHG_BUGCHECK_DECL
  90
  91         m = (volatile __u32 *) addr + (nr >> 5);
  92         mask = ~(1 << (nr & 31));
  93         do {
  94                 CMPXCHG_BUGCHECK(m);
  95                 old = *m;
  96                 new = old & mask;
  97         } while (cmpxchg_acq(m, old, new) != old);
  98 }
  99
 100 /**
 101  * clear_bit_unlock - Clears a bit in memory with release
 102  * @nr: Bit to clear
 103  * @addr: Address to start counting from
 104  *
 105  * clear_bit_unlock() is atomic and may not be reordered.  It does
 106  * contain a memory barrier suitable for unlock type operations.
 107  */
 108 static __inline__ void
 109 clear_bit_unlock (int nr, volatile void *addr)
 110 {
 111         __u32 mask, old, new;
 112         volatile __u32 *m;
 113         CMPXCHG_BUGCHECK_DECL
 114
 115         m = (volatile __u32 *) addr + (nr >> 5);
 116         mask = ~(1 << (nr & 31));
 117         do {
 118                 CMPXCHG_BUGCHECK(m);
 119                 old = *m;
 120                 new = old & mask;
 121         } while (cmpxchg_rel(m, old, new) != old);
 122 }
 123
 124 /**
 125  * __clear_bit_unlock - Non-atomically clears a bit in memory with release
 126  * @nr: Bit to clear
 127  * @addr: Address to start counting from
 128  *
 129  * Similarly to clear_bit_unlock, the implementation uses a store
 130  * with release semantics. See also __raw_spin_unlock().
 131  */
 132 static __inline__ void
 133 __clear_bit_unlock(int nr, void *addr)
 134 {
 135         __u32 * const m = (__u32 *) addr + (nr >> 5);
 136         __u32 const new = *m & ~(1 << (nr & 31));
 137
 138         ia64_st4_rel_nta(m, new);
 139 }
 140
 141 /**
 142  * __clear_bit - Clears a bit in memory (non-atomic version)
 143  * @nr: the bit to clear
 144  * @addr: the address to start counting from
 145  *
 146  * Unlike clear_bit(), this function is non-atomic and may be reordered.
 147  * If it's called on the same region of memory simultaneously, the effect
 148  * may be that only one operation succeeds.
 149  */
 150 static __inline__ void
 151 __clear_bit (int nr, volatile void *addr)
 152 {
 153         *((__u32 *) addr + (nr >> 5)) &= ~(1 << (nr & 31));
 154 }
 155
 156 /**
 157  * change_bit - Toggle a bit in memory
 158  * @nr: Bit to toggle
 159  * @addr: Address to start counting from
 160  *
 161  * change_bit() is atomic and may not be reordered.
 162  * Note that @nr may be almost arbitrarily large; this function is not
 163  * restricted to acting on a single-word quantity.
 164  */
 165 static __inline__ void
 166 change_bit (int nr, volatile void *addr)
 167 {
 168         __u32 bit, old, new;
 169         volatile __u32 *m;
 170         CMPXCHG_BUGCHECK_DECL
 171
 172         m = (volatile __u32 *) addr + (nr >> 5);
 173         bit = (1 << (nr & 31));
 174         do {
 175                 CMPXCHG_BUGCHECK(m);
 176                 old = *m;
 177                 new = old ^ bit;
 178         } while (cmpxchg_acq(m, old, new) != old);
 179 }
 180
 181 /**
 182  * __change_bit - Toggle a bit in memory
 183  * @nr: the bit to toggle
 184  * @addr: the address to start counting from
 185  *
 186  * Unlike change_bit(), this function is non-atomic and may be reordered.
 187  * If it's called on the same region of memory simultaneously, the effect
 188  * may be that only one operation succeeds.
 189  */
 190 static __inline__ void
 191 __change_bit (int nr, volatile void *addr)
 192 {
 193         *((__u32 *) addr + (nr >> 5)) ^= (1 << (nr & 31));
 194 }
 195
 196 /**
 197  * test_and_set_bit - Set a bit and return its old value
 198  * @nr: Bit to set
 199  * @addr: Address to count from
 200  *
 201  * This operation is atomic and cannot be reordered.
 202  * It also implies the acquisition side of the memory barrier.
 203  */
 204 static __inline__ int
 205 test_and_set_bit (int nr, volatile void *addr)
 206 {
 207         __u32 bit, old, new;
 208         volatile __u32 *m;
 209         CMPXCHG_BUGCHECK_DECL
 210
 211         m = (volatile __u32 *) addr + (nr >> 5);
 212         bit = 1 << (nr & 31);
 213         do {
 214                 CMPXCHG_BUGCHECK(m);
 215                 old = *m;
 216                 new = old | bit;
 217         } while (cmpxchg_acq(m, old, new) != old);
 218         return (old & bit) != 0;
 219 }
 220
 221 /**
 222  * test_and_set_bit_lock - Set a bit and return its old value for lock
 223  * @nr: Bit to set
 224  * @addr: Address to count from
 225  *
 226  * This is the same as test_and_set_bit on ia64
 227  */
 228 #define test_and_set_bit_lock test_and_set_bit
 229
 230 /**
 231  * __test_and_set_bit - Set a bit and return its old value
 232  * @nr: Bit to set
 233  * @addr: Address to count from
 234  *
 235  * This operation is non-atomic and can be reordered.
 236  * If two examples of this operation race, one can appear to succeed
 237  * but actually fail.  You must protect multiple accesses with a lock.
 238  */
 239 static __inline__ int
 240 __test_and_set_bit (int nr, volatile void *addr)
 241 {
 242         __u32 *p = (__u32 *) addr + (nr >> 5);
 243         __u32 m = 1 << (nr & 31);
 244         int oldbitset = (*p & m) != 0;
 245
 246         *p |= m;
 247         return oldbitset;
 248 }
 249
 250 /**
 251  * test_and_clear_bit - Clear a bit and return its old value
 252  * @nr: Bit to clear
 253  * @addr: Address to count from
 254  *
 255  * This operation is atomic and cannot be reordered.
 256  * It also implies the acquisition side of the memory barrier.
 257  */
 258 static __inline__ int
 259 test_and_clear_bit (int nr, volatile void *addr)
 260 {
 261         __u32 mask, old, new;
 262         volatile __u32 *m;
 263         CMPXCHG_BUGCHECK_DECL
 264
 265         m = (volatile __u32 *) addr + (nr >> 5);
 266         mask = ~(1 << (nr & 31));
 267         do {
 268                 CMPXCHG_BUGCHECK(m);
 269                 old = *m;
 270                 new = old & mask;
 271         } while (cmpxchg_acq(m, old, new) != old);
 272         return (old & ~mask) != 0;
 273 }
 274
 275 /**
 276  * __test_and_clear_bit - Clear a bit and return its old value
 277  * @nr: Bit to clear
 278  * @addr: Address to count from
 279  *
 280  * This operation is non-atomic and can be reordered.
 281  * If two examples of this operation race, one can appear to succeed
 282  * but actually fail.  You must protect multiple accesses with a lock.
 283  */
 284 static __inline__ int
 285 __test_and_clear_bit(int nr, volatile void * addr)
 286 {
 287         __u32 *p = (__u32 *) addr + (nr >> 5);
 288         __u32 m = 1 << (nr & 31);
 289         int oldbitset = *p & m;
 290
 291         *p &= ~m;
 292         return oldbitset;
 293 }
 294
 295 /**
 296  * test_and_change_bit - Change a bit and return its old value
 297  * @nr: Bit to change
 298  * @addr: Address to count from
 299  *
 300  * This operation is atomic and cannot be reordered.
 301  * It also implies the acquisition side of the memory barrier.
 302  */
 303 static __inline__ int
 304 test_and_change_bit (int nr, volatile void *addr)
 305 {
 306         __u32 bit, old, new;
 307         volatile __u32 *m;
 308         CMPXCHG_BUGCHECK_DECL
 309
 310         m = (volatile __u32 *) addr + (nr >> 5);
 311         bit = (1 << (nr & 31));
 312         do {
 313                 CMPXCHG_BUGCHECK(m);
 314                 old = *m;
 315                 new = old ^ bit;
 316         } while (cmpxchg_acq(m, old, new) != old);
 317         return (old & bit) != 0;
 318 }
 319
 320 /**
 321  * __test_and_change_bit - Change a bit and return its old value
 322  * @nr: Bit to change
 323  * @addr: Address to count from
 324  *
 325  * This operation is non-atomic and can be reordered.
 326  */
 327 static __inline__ int
 328 __test_and_change_bit (int nr, void *addr)
 329 {
 330         __u32 old, bit = (1 << (nr & 31));
 331         __u32 *m = (__u32 *) addr + (nr >> 5);
 332
 333         old = *m;
 334         *m = old ^ bit;
 335         return (old & bit) != 0;
 336 }
 337
 338 static __inline__ int
 339 test_bit (int nr, const volatile void *addr)
 340 {
 341         return 1 & (((const volatile __u32 *) addr)[nr >> 5] >> (nr & 31));
 342 }
 343
 344 /**
 345  * ffz - find the first zero bit in a long word
 346  * @x: The long word to find the bit in
 347  *
 348  * Returns the bit-number (0..63) of the first (least significant) zero bit.
 349  * Undefined if no zero exists, so code should check against ~0UL first...
 350  */
 351 static inline unsigned long
 352 ffz (unsigned long x)
 353 {
 354         unsigned long result;
 355
 356         result = ia64_popcnt(x & (~x - 1));
 357         return result;
 358 }
 359
 360 /**
 361  * __ffs - find first bit in word.
 362  * @x: The word to search
 363  *
 364  * Undefined if no bit exists, so code should check against 0 first.
 365  */
 366 static __inline__ unsigned long
 367 __ffs (unsigned long x)
 368 {
 369         unsigned long result;
 370
 371         result = ia64_popcnt((x-1) & ~x);
 372         return result;
 373 }
 374
 375 #ifdef __KERNEL__
 376
 377 /*
 378  * Return bit number of last (most-significant) bit set.  Undefined
 379  * for x==0.  Bits are numbered from 0..63 (e.g., ia64_fls(9) == 3).
 380  */
 381 static inline unsigned long
 382 ia64_fls (unsigned long x)
 383 {
 384         long double d = x;
 385         long exp;
 386
 387         exp = ia64_getf_exp(d);
 388         return exp - 0xffff;
 389 }
 390
 391 /*
 392  * Find the last (most significant) bit set.  Returns 0 for x==0 and
 393  * bits are numbered from 1..32 (e.g., fls(9) == 4).
 394  */
 395 static inline int
 396 fls (int t)
 397 {
 398         unsigned long x = t & 0xffffffffu;
 399
 400         if (!x)
 401                 return 0;
 402         x |= x >> 1;
 403         x |= x >> 2;
 404         x |= x >> 4;
 405         x |= x >> 8;
 406         x |= x >> 16;
 407         return ia64_popcnt(x);
 408 }
 409
 410 /*
 411  * Find the last (most significant) bit set.  Undefined for x==0.
 412  * Bits are numbered from 0..63 (e.g., __fls(9) == 3).
 413  */
 414 static inline unsigned long
 415 __fls (unsigned long x)
 416 {
 417         x |= x >> 1;
 418         x |= x >> 2;
 419         x |= x >> 4;
 420         x |= x >> 8;
 421         x |= x >> 16;
 422         x |= x >> 32;
 423         return ia64_popcnt(x) - 1;
 424 }
 425
 426 #include <asm-generic/bitops/fls64.h>
 427
 428 /*
 429  * ffs: find first bit set. This is defined the same way as the libc and
 430  * compiler builtin ffs routines, therefore differs in spirit from the above
 431  * ffz (man ffs): it operates on "int" values only and the result value is the
 432  * bit number + 1.  ffs(0) is defined to return zero.
 433  */
 434 #define ffs(x)  __builtin_ffs(x)
 435
 436 /*
 437  * hweightN: returns the hamming weight (i.e. the number
 438  * of bits set) of a N-bit word
 439  */
 440 static __inline__ unsigned long
 441 hweight64 (unsigned long x)
 442 {
 443         unsigned long result;
 444         result = ia64_popcnt(x);
 445         return result;
 446 }
 447
 448 #define hweight32(x)    (unsigned int) hweight64((x) & 0xfffffffful)
 449 #define hweight16(x)    (unsigned int) hweight64((x) & 0xfffful)
 450 #define hweight8(x)     (unsigned int) hweight64((x) & 0xfful)
 451
 452 #endif /* __KERNEL__ */
 453
 454 #include <asm-generic/bitops/find.h>
 455
 456 #ifdef __KERNEL__
 457
 458 #include <asm-generic/bitops/ext2-non-atomic.h>
 459
 460 #define ext2_set_bit_atomic(l,n,a)      test_and_set_bit(n,a)
 461 #define ext2_clear_bit_atomic(l,n,a)    test_and_clear_bit(n,a)
 462
 463 #include <asm-generic/bitops/minix.h>
 464 #include <asm-generic/bitops/sched.h>
 465
 466 #endif /* __KERNEL__ */
 467
 468 #endif /* _ASM_IA64_BITOPS_H */