LXR linux/arch/tile/include/asm/bitops

   1/*
   2 * Copyright 2011 Tilera Corporation. All Rights Reserved.
   3 *
   4 *   This program is free software; you can redistribute it and/or
   5 *   modify it under the terms of the GNU General Public License
   6 *   as published by the Free Software Foundation, version 2.
   7 *
   8 *   This program is distributed in the hope that it will be useful, but
   9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11 *   NON INFRINGEMENT.  See the GNU General Public License for
  12 *   more details.
  13 */
  14
  15#ifndef _ASM_TILE_BITOPS_64_H
  16#define _ASM_TILE_BITOPS_64_H
  17
  18#include <linux/compiler.h>
  19#include <asm/cmpxchg.h>
  20
  21/* See <asm/bitops.h> for API comments. */
  22
  23static inline void set_bit(unsigned nr, volatile unsigned long *addr)
  24{
  25        unsigned long mask = (1UL << (nr % BITS_PER_LONG));
  26        __insn_fetchor((void *)(addr + nr / BITS_PER_LONG), mask);
  27}
  28
  29static inline void clear_bit(unsigned nr, volatile unsigned long *addr)
  30{
  31        unsigned long mask = (1UL << (nr % BITS_PER_LONG));
  32        __insn_fetchand((void *)(addr + nr / BITS_PER_LONG), ~mask);
  33}
  34
  35#define smp_mb__before_clear_bit()      smp_mb()
  36#define smp_mb__after_clear_bit()       smp_mb()
  37
  38
  39static inline void change_bit(unsigned nr, volatile unsigned long *addr)
  40{
  41        unsigned long mask = (1UL << (nr % BITS_PER_LONG));
  42        unsigned long guess, oldval;
  43        addr += nr / BITS_PER_LONG;
  44        oldval = *addr;
  45        do {
  46                guess = oldval;
  47                oldval = cmpxchg(addr, guess, guess ^ mask);
  48        } while (guess != oldval);
  49}
  50
  51
  52/*
  53 * The test_and_xxx_bit() routines require a memory fence before we
  54 * start the operation, and after the operation completes.  We use
  55 * smp_mb() before, and rely on the "!= 0" comparison, plus a compiler
  56 * barrier(), to block until the atomic op is complete.
  57 */
  58
  59static inline int test_and_set_bit(unsigned nr, volatile unsigned long *addr)
  60{
  61        int val;
  62        unsigned long mask = (1UL << (nr % BITS_PER_LONG));
  63        smp_mb();  /* barrier for proper semantics */
  64        val = (__insn_fetchor((void *)(addr + nr / BITS_PER_LONG), mask)
  65               & mask) != 0;
  66        barrier();
  67        return val;
  68}
  69
  70
  71static inline int test_and_clear_bit(unsigned nr, volatile unsigned long *addr)
  72{
  73        int val;
  74        unsigned long mask = (1UL << (nr % BITS_PER_LONG));
  75        smp_mb();  /* barrier for proper semantics */
  76        val = (__insn_fetchand((void *)(addr + nr / BITS_PER_LONG), ~mask)
  77               & mask) != 0;
  78        barrier();
  79        return val;
  80}
  81
  82
  83static inline int test_and_change_bit(unsigned nr,
  84                                      volatile unsigned long *addr)
  85{
  86        unsigned long mask = (1UL << (nr % BITS_PER_LONG));
  87        unsigned long guess, oldval;
  88        addr += nr / BITS_PER_LONG;
  89        oldval = *addr;
  90        do {
  91                guess = oldval;
  92                oldval = cmpxchg(addr, guess, guess ^ mask);
  93        } while (guess != oldval);
  94        return (oldval & mask) != 0;
  95}
  96
  97#include <asm-generic/bitops/ext2-atomic-setbit.h>
  98
  99#endif /* _ASM_TILE_BITOPS_64_H */
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