linux/arch/ia64/include/asm/bitops.h
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   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _ASM_IA64_BITOPS_H
   3#define _ASM_IA64_BITOPS_H
   4
   5/*
   6 * Copyright (C) 1998-2003 Hewlett-Packard Co
   7 *      David Mosberger-Tang <davidm@hpl.hp.com>
   8 *
   9 * 02/06/02 find_next_bit() and find_first_bit() added from Erich Focht's ia64
  10 * O(1) scheduler patch
  11 */
  12
  13#ifndef _LINUX_BITOPS_H
  14#error only <linux/bitops.h> can be included directly
  15#endif
  16
  17#include <linux/compiler.h>
  18#include <linux/types.h>
  19#include <asm/intrinsics.h>
  20#include <asm/barrier.h>
  21
  22/**
  23 * set_bit - Atomically set a bit in memory
  24 * @nr: the bit to set
  25 * @addr: the address to start counting from
  26 *
  27 * This function is atomic and may not be reordered.  See __set_bit()
  28 * if you do not require the atomic guarantees.
  29 * Note that @nr may be almost arbitrarily large; this function is not
  30 * restricted to acting on a single-word quantity.
  31 *
  32 * The address must be (at least) "long" aligned.
  33 * Note that there are driver (e.g., eepro100) which use these operations to
  34 * operate on hw-defined data-structures, so we can't easily change these
  35 * operations to force a bigger alignment.
  36 *
  37 * bit 0 is the LSB of addr; bit 32 is the LSB of (addr+1).
  38 */
  39static __inline__ void
  40set_bit (int nr, volatile void *addr)
  41{
  42        __u32 bit, old, new;
  43        volatile __u32 *m;
  44        CMPXCHG_BUGCHECK_DECL
  45
  46        m = (volatile __u32 *) addr + (nr >> 5);
  47        bit = 1 << (nr & 31);
  48        do {
  49                CMPXCHG_BUGCHECK(m);
  50                old = *m;
  51                new = old | bit;
  52        } while (cmpxchg_acq(m, old, new) != old);
  53}
  54
  55/**
  56 * __set_bit - Set a bit in memory
  57 * @nr: the bit to set
  58 * @addr: the address to start counting from
  59 *
  60 * Unlike set_bit(), this function is non-atomic and may be reordered.
  61 * If it's called on the same region of memory simultaneously, the effect
  62 * may be that only one operation succeeds.
  63 */
  64static __inline__ void
  65__set_bit (int nr, volatile void *addr)
  66{
  67        *((__u32 *) addr + (nr >> 5)) |= (1 << (nr & 31));
  68}
  69
  70/**
  71 * clear_bit - Clears a bit in memory
  72 * @nr: Bit to clear
  73 * @addr: Address to start counting from
  74 *
  75 * clear_bit() is atomic and may not be reordered.  However, it does
  76 * not contain a memory barrier, so if it is used for locking purposes,
  77 * you should call smp_mb__before_atomic() and/or smp_mb__after_atomic()
  78 * in order to ensure changes are visible on other processors.
  79 */
  80static __inline__ void
  81clear_bit (int nr, volatile void *addr)
  82{
  83        __u32 mask, old, new;
  84        volatile __u32 *m;
  85        CMPXCHG_BUGCHECK_DECL
  86
  87        m = (volatile __u32 *) addr + (nr >> 5);
  88        mask = ~(1 << (nr & 31));
  89        do {
  90                CMPXCHG_BUGCHECK(m);
  91                old = *m;
  92                new = old & mask;
  93        } while (cmpxchg_acq(m, old, new) != old);
  94}
  95
  96/**
  97 * clear_bit_unlock - Clears a bit in memory with release
  98 * @nr: Bit to clear
  99 * @addr: Address to start counting from
 100 *
 101 * clear_bit_unlock() is atomic and may not be reordered.  It does
 102 * contain a memory barrier suitable for unlock type operations.
 103 */
 104static __inline__ void
 105clear_bit_unlock (int nr, volatile void *addr)
 106{
 107        __u32 mask, old, new;
 108        volatile __u32 *m;
 109        CMPXCHG_BUGCHECK_DECL
 110
 111        m = (volatile __u32 *) addr + (nr >> 5);
 112        mask = ~(1 << (nr & 31));
 113        do {
 114                CMPXCHG_BUGCHECK(m);
 115                old = *m;
 116                new = old & mask;
 117        } while (cmpxchg_rel(m, old, new) != old);
 118}
 119
 120/**
 121 * __clear_bit_unlock - Non-atomically clears a bit in memory with release
 122 * @nr: Bit to clear
 123 * @addr: Address to start counting from
 124 *
 125 * Similarly to clear_bit_unlock, the implementation uses a store
 126 * with release semantics. See also arch_spin_unlock().
 127 */
 128static __inline__ void
 129__clear_bit_unlock(int nr, void *addr)
 130{
 131        __u32 * const m = (__u32 *) addr + (nr >> 5);
 132        __u32 const new = *m & ~(1 << (nr & 31));
 133
 134        ia64_st4_rel_nta(m, new);
 135}
 136
 137/**
 138 * __clear_bit - Clears a bit in memory (non-atomic version)
 139 * @nr: the bit to clear
 140 * @addr: the address to start counting from
 141 *
 142 * Unlike clear_bit(), this function is non-atomic and may be reordered.
 143 * If it's called on the same region of memory simultaneously, the effect
 144 * may be that only one operation succeeds.
 145 */
 146static __inline__ void
 147__clear_bit (int nr, volatile void *addr)
 148{
 149        *((__u32 *) addr + (nr >> 5)) &= ~(1 << (nr & 31));
 150}
 151
 152/**
 153 * change_bit - Toggle a bit in memory
 154 * @nr: Bit to toggle
 155 * @addr: Address to start counting from
 156 *
 157 * change_bit() is atomic and may not be reordered.
 158 * Note that @nr may be almost arbitrarily large; this function is not
 159 * restricted to acting on a single-word quantity.
 160 */
 161static __inline__ void
 162change_bit (int nr, volatile void *addr)
 163{
 164        __u32 bit, old, new;
 165        volatile __u32 *m;
 166        CMPXCHG_BUGCHECK_DECL
 167
 168        m = (volatile __u32 *) addr + (nr >> 5);
 169        bit = (1 << (nr & 31));
 170        do {
 171                CMPXCHG_BUGCHECK(m);
 172                old = *m;
 173                new = old ^ bit;
 174        } while (cmpxchg_acq(m, old, new) != old);
 175}
 176
 177/**
 178 * __change_bit - Toggle a bit in memory
 179 * @nr: the bit to toggle
 180 * @addr: the address to start counting from
 181 *
 182 * Unlike change_bit(), this function is non-atomic and may be reordered.
 183 * If it's called on the same region of memory simultaneously, the effect
 184 * may be that only one operation succeeds.
 185 */
 186static __inline__ void
 187__change_bit (int nr, volatile void *addr)
 188{
 189        *((__u32 *) addr + (nr >> 5)) ^= (1 << (nr & 31));
 190}
 191
 192/**
 193 * test_and_set_bit - Set a bit and return its old value
 194 * @nr: Bit to set
 195 * @addr: Address to count from
 196 *
 197 * This operation is atomic and cannot be reordered.  
 198 * It also implies the acquisition side of the memory barrier.
 199 */
 200static __inline__ int
 201test_and_set_bit (int nr, volatile void *addr)
 202{
 203        __u32 bit, old, new;
 204        volatile __u32 *m;
 205        CMPXCHG_BUGCHECK_DECL
 206
 207        m = (volatile __u32 *) addr + (nr >> 5);
 208        bit = 1 << (nr & 31);
 209        do {
 210                CMPXCHG_BUGCHECK(m);
 211                old = *m;
 212                new = old | bit;
 213        } while (cmpxchg_acq(m, old, new) != old);
 214        return (old & bit) != 0;
 215}
 216
 217/**
 218 * test_and_set_bit_lock - Set a bit and return its old value for lock
 219 * @nr: Bit to set
 220 * @addr: Address to count from
 221 *
 222 * This is the same as test_and_set_bit on ia64
 223 */
 224#define test_and_set_bit_lock test_and_set_bit
 225
 226/**
 227 * __test_and_set_bit - Set a bit and return its old value
 228 * @nr: Bit to set
 229 * @addr: Address to count from
 230 *
 231 * This operation is non-atomic and can be reordered.  
 232 * If two examples of this operation race, one can appear to succeed
 233 * but actually fail.  You must protect multiple accesses with a lock.
 234 */
 235static __inline__ int
 236__test_and_set_bit (int nr, volatile void *addr)
 237{
 238        __u32 *p = (__u32 *) addr + (nr >> 5);
 239        __u32 m = 1 << (nr & 31);
 240        int oldbitset = (*p & m) != 0;
 241
 242        *p |= m;
 243        return oldbitset;
 244}
 245
 246/**
 247 * test_and_clear_bit - Clear a bit and return its old value
 248 * @nr: Bit to clear
 249 * @addr: Address to count from
 250 *
 251 * This operation is atomic and cannot be reordered.  
 252 * It also implies the acquisition side of the memory barrier.
 253 */
 254static __inline__ int
 255test_and_clear_bit (int nr, volatile void *addr)
 256{
 257        __u32 mask, old, new;
 258        volatile __u32 *m;
 259        CMPXCHG_BUGCHECK_DECL
 260
 261        m = (volatile __u32 *) addr + (nr >> 5);
 262        mask = ~(1 << (nr & 31));
 263        do {
 264                CMPXCHG_BUGCHECK(m);
 265                old = *m;
 266                new = old & mask;
 267        } while (cmpxchg_acq(m, old, new) != old);
 268        return (old & ~mask) != 0;
 269}
 270
 271/**
 272 * __test_and_clear_bit - Clear a bit and return its old value
 273 * @nr: Bit to clear
 274 * @addr: Address to count from
 275 *
 276 * This operation is non-atomic and can be reordered.  
 277 * If two examples of this operation race, one can appear to succeed
 278 * but actually fail.  You must protect multiple accesses with a lock.
 279 */
 280static __inline__ int
 281__test_and_clear_bit(int nr, volatile void * addr)
 282{
 283        __u32 *p = (__u32 *) addr + (nr >> 5);
 284        __u32 m = 1 << (nr & 31);
 285        int oldbitset = (*p & m) != 0;
 286
 287        *p &= ~m;
 288        return oldbitset;
 289}
 290
 291/**
 292 * test_and_change_bit - Change a bit and return its old value
 293 * @nr: Bit to change
 294 * @addr: Address to count from
 295 *
 296 * This operation is atomic and cannot be reordered.  
 297 * It also implies the acquisition side of the memory barrier.
 298 */
 299static __inline__ int
 300test_and_change_bit (int nr, volatile void *addr)
 301{
 302        __u32 bit, old, new;
 303        volatile __u32 *m;
 304        CMPXCHG_BUGCHECK_DECL
 305
 306        m = (volatile __u32 *) addr + (nr >> 5);
 307        bit = (1 << (nr & 31));
 308        do {
 309                CMPXCHG_BUGCHECK(m);
 310                old = *m;
 311                new = old ^ bit;
 312        } while (cmpxchg_acq(m, old, new) != old);
 313        return (old & bit) != 0;
 314}
 315
 316/**
 317 * __test_and_change_bit - Change a bit and return its old value
 318 * @nr: Bit to change
 319 * @addr: Address to count from
 320 *
 321 * This operation is non-atomic and can be reordered.
 322 */
 323static __inline__ int
 324__test_and_change_bit (int nr, void *addr)
 325{
 326        __u32 old, bit = (1 << (nr & 31));
 327        __u32 *m = (__u32 *) addr + (nr >> 5);
 328
 329        old = *m;
 330        *m = old ^ bit;
 331        return (old & bit) != 0;
 332}
 333
 334static __inline__ int
 335test_bit (int nr, const volatile void *addr)
 336{
 337        return 1 & (((const volatile __u32 *) addr)[nr >> 5] >> (nr & 31));
 338}
 339
 340/**
 341 * ffz - find the first zero bit in a long word
 342 * @x: The long word to find the bit in
 343 *
 344 * Returns the bit-number (0..63) of the first (least significant) zero bit.
 345 * Undefined if no zero exists, so code should check against ~0UL first...
 346 */
 347static inline unsigned long
 348ffz (unsigned long x)
 349{
 350        unsigned long result;
 351
 352        result = ia64_popcnt(x & (~x - 1));
 353        return result;
 354}
 355
 356/**
 357 * __ffs - find first bit in word.
 358 * @x: The word to search
 359 *
 360 * Undefined if no bit exists, so code should check against 0 first.
 361 */
 362static __inline__ unsigned long
 363__ffs (unsigned long x)
 364{
 365        unsigned long result;
 366
 367        result = ia64_popcnt((x-1) & ~x);
 368        return result;
 369}
 370
 371#ifdef __KERNEL__
 372
 373/*
 374 * Return bit number of last (most-significant) bit set.  Undefined
 375 * for x==0.  Bits are numbered from 0..63 (e.g., ia64_fls(9) == 3).
 376 */
 377static inline unsigned long
 378ia64_fls (unsigned long x)
 379{
 380        long double d = x;
 381        long exp;
 382
 383        exp = ia64_getf_exp(d);
 384        return exp - 0xffff;
 385}
 386
 387/*
 388 * Find the last (most significant) bit set.  Returns 0 for x==0 and
 389 * bits are numbered from 1..32 (e.g., fls(9) == 4).
 390 */
 391static inline int fls(unsigned int t)
 392{
 393        unsigned long x = t & 0xffffffffu;
 394
 395        if (!x)
 396                return 0;
 397        x |= x >> 1;
 398        x |= x >> 2;
 399        x |= x >> 4;
 400        x |= x >> 8;
 401        x |= x >> 16;
 402        return ia64_popcnt(x);
 403}
 404
 405/*
 406 * Find the last (most significant) bit set.  Undefined for x==0.
 407 * Bits are numbered from 0..63 (e.g., __fls(9) == 3).
 408 */
 409static inline unsigned long
 410__fls (unsigned long x)
 411{
 412        x |= x >> 1;
 413        x |= x >> 2;
 414        x |= x >> 4;
 415        x |= x >> 8;
 416        x |= x >> 16;
 417        x |= x >> 32;
 418        return ia64_popcnt(x) - 1;
 419}
 420
 421#include <asm-generic/bitops/fls64.h>
 422
 423#include <asm-generic/bitops/builtin-ffs.h>
 424
 425/*
 426 * hweightN: returns the hamming weight (i.e. the number
 427 * of bits set) of a N-bit word
 428 */
 429static __inline__ unsigned long __arch_hweight64(unsigned long x)
 430{
 431        unsigned long result;
 432        result = ia64_popcnt(x);
 433        return result;
 434}
 435
 436#define __arch_hweight32(x) ((unsigned int) __arch_hweight64((x) & 0xfffffffful))
 437#define __arch_hweight16(x) ((unsigned int) __arch_hweight64((x) & 0xfffful))
 438#define __arch_hweight8(x)  ((unsigned int) __arch_hweight64((x) & 0xfful))
 439
 440#include <asm-generic/bitops/const_hweight.h>
 441
 442#endif /* __KERNEL__ */
 443
 444#include <asm-generic/bitops/find.h>
 445
 446#ifdef __KERNEL__
 447
 448#include <asm-generic/bitops/le.h>
 449
 450#include <asm-generic/bitops/ext2-atomic-setbit.h>
 451
 452#include <asm-generic/bitops/sched.h>
 453
 454#endif /* __KERNEL__ */
 455
 456#endif /* _ASM_IA64_BITOPS_H */
 457