root/arch/sh/include/asm/bitops-op32.h

INCLUDED FROM

DEFINITIONS

1. __set_bit
2. __clear_bit
3. __change_bit
4. __test_and_set_bit
5. __test_and_clear_bit
6. __test_and_change_bit
7. test_bit

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