LXR linux/arch/sh/include/asm/bitops-op32.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef __ASM_SH_BITOPS_OP32_H
   3#define __ASM_SH_BITOPS_OP32_H
   4
   5/*
   6 * The bit modifying instructions on SH-2A are only capable of working
   7 * with a 3-bit immediate, which signifies the shift position for the bit
   8 * being worked on.
   9 */
  10#if defined(__BIG_ENDIAN)
  11#define BITOP_LE_SWIZZLE        ((BITS_PER_LONG-1) & ~0x7)
  12#define BYTE_NUMBER(nr)         ((nr ^ BITOP_LE_SWIZZLE) / BITS_PER_BYTE)
  13#define BYTE_OFFSET(nr)         ((nr ^ BITOP_LE_SWIZZLE) % BITS_PER_BYTE)
  14#else
  15#define BYTE_NUMBER(nr)         ((nr) / BITS_PER_BYTE)
  16#define BYTE_OFFSET(nr)         ((nr) % BITS_PER_BYTE)
  17#endif
  18
  19static inline void __set_bit(int nr, volatile unsigned long *addr)
  20{
  21        if (__builtin_constant_p(nr)) {
  22                __asm__ __volatile__ (
  23                        "bset.b %1, @(%O2,%0)           ! __set_bit\n\t"
  24                        : "+r" (addr)
  25                        : "i" (BYTE_OFFSET(nr)), "i" (BYTE_NUMBER(nr))
  26                        : "t", "memory"
  27                );
  28        } else {
  29                unsigned long mask = BIT_MASK(nr);
  30                unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
  31
  32                *p |= mask;
  33        }
  34}
  35
  36static inline void __clear_bit(int nr, volatile unsigned long *addr)
  37{
  38        if (__builtin_constant_p(nr)) {
  39                __asm__ __volatile__ (
  40                        "bclr.b %1, @(%O2,%0)           ! __clear_bit\n\t"
  41                        : "+r" (addr)
  42                        : "i" (BYTE_OFFSET(nr)),
  43                          "i" (BYTE_NUMBER(nr))
  44                        : "t", "memory"
  45                );
  46        } else {
  47                unsigned long mask = BIT_MASK(nr);
  48                unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
  49
  50                *p &= ~mask;
  51        }
  52}
  53
  54/**
  55 * __change_bit - Toggle a bit in memory
  56 * @nr: the bit to change
  57 * @addr: the address to start counting from
  58 *
  59 * Unlike change_bit(), this function is non-atomic and may be reordered.
  60 * If it's called on the same region of memory simultaneously, the effect
  61 * may be that only one operation succeeds.
  62 */
  63static inline void __change_bit(int nr, volatile unsigned long *addr)
  64{
  65        if (__builtin_constant_p(nr)) {
  66                __asm__ __volatile__ (
  67                        "bxor.b %1, @(%O2,%0)           ! __change_bit\n\t"
  68                        : "+r" (addr)
  69                        : "i" (BYTE_OFFSET(nr)),
  70                          "i" (BYTE_NUMBER(nr))
  71                        : "t", "memory"
  72                );
  73        } else {
  74                unsigned long mask = BIT_MASK(nr);
  75                unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
  76
  77                *p ^= mask;
  78        }
  79}
  80
  81/**
  82 * __test_and_set_bit - Set a bit and return its old value
  83 * @nr: Bit to set
  84 * @addr: Address to count from
  85 *
  86 * This operation is non-atomic and can be reordered.
  87 * If two examples of this operation race, one can appear to succeed
  88 * but actually fail.  You must protect multiple accesses with a lock.
  89 */
  90static inline int __test_and_set_bit(int nr, volatile unsigned long *addr)
  91{
  92        unsigned long mask = BIT_MASK(nr);
  93        unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
  94        unsigned long old = *p;
  95
  96        *p = old | mask;
  97        return (old & mask) != 0;
  98}
  99
 100/**
 101 * __test_and_clear_bit - Clear a bit and return its old value
 102 * @nr: Bit to clear
 103 * @addr: Address to count from
 104 *
 105 * This operation is non-atomic and can be reordered.
 106 * If two examples of this operation race, one can appear to succeed
 107 * but actually fail.  You must protect multiple accesses with a lock.
 108 */
 109static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr)
 110{
 111        unsigned long mask = BIT_MASK(nr);
 112        unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
 113        unsigned long old = *p;
 114
 115        *p = old & ~mask;
 116        return (old & mask) != 0;
 117}
 118
 119/* WARNING: non atomic and it can be reordered! */
 120static inline int __test_and_change_bit(int nr,
 121                                            volatile unsigned long *addr)
 122{
 123        unsigned long mask = BIT_MASK(nr);
 124        unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
 125        unsigned long old = *p;
 126
 127        *p = old ^ mask;
 128        return (old & mask) != 0;
 129}
 130
 131/**
 132 * test_bit - Determine whether a bit is set
 133 * @nr: bit number to test
 134 * @addr: Address to start counting from
 135 */
 136static inline int test_bit(int nr, const volatile unsigned long *addr)
 137{
 138        return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));
 139}
 140
 141#endif /* __ASM_SH_BITOPS_OP32_H */
 142