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       1                 :            : /* SPDX-License-Identifier: GPL-2.0 */
       2                 :            : #ifndef _ASM_GENERIC_BITOPS_NON_ATOMIC_H_
       3                 :            : #define _ASM_GENERIC_BITOPS_NON_ATOMIC_H_
       4                 :            : 
       5                 :            : #include <asm/types.h>
       6                 :            : 
       7                 :            : /**
       8                 :            :  * __set_bit - Set a bit in memory
       9                 :            :  * @nr: the bit to set
      10                 :            :  * @addr: the address to start counting from
      11                 :            :  *
      12                 :            :  * Unlike set_bit(), this function is non-atomic and may be reordered.
      13                 :            :  * If it's called on the same region of memory simultaneously, the effect
      14                 :            :  * may be that only one operation succeeds.
      15                 :            :  */
      16                 :          3 : static inline void __set_bit(int nr, volatile unsigned long *addr)
      17                 :            : {
      18                 :          3 :         unsigned long mask = BIT_MASK(nr);
      19                 :          3 :         unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
      20                 :            : 
      21                 :          3 :         *p  |= mask;
      22                 :          3 : }
      23                 :            : 
      24                 :          3 : static inline void __clear_bit(int nr, volatile unsigned long *addr)
      25                 :            : {
      26                 :          3 :         unsigned long mask = BIT_MASK(nr);
      27                 :          3 :         unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
      28                 :            : 
      29                 :          3 :         *p &= ~mask;
      30                 :          3 : }
      31                 :            : 
      32                 :            : /**
      33                 :            :  * __change_bit - Toggle a bit in memory
      34                 :            :  * @nr: the bit to change
      35                 :            :  * @addr: the address to start counting from
      36                 :            :  *
      37                 :            :  * Unlike change_bit(), this function is non-atomic and may be reordered.
      38                 :            :  * If it's called on the same region of memory simultaneously, the effect
      39                 :            :  * may be that only one operation succeeds.
      40                 :            :  */
      41                 :            : static inline void __change_bit(int nr, volatile unsigned long *addr)
      42                 :            : {
      43                 :          3 :         unsigned long mask = BIT_MASK(nr);
      44                 :          0 :         unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
      45                 :            : 
      46                 :          3 :         *p ^= mask;
      47                 :            : }
      48                 :            : 
      49                 :            : /**
      50                 :            :  * __test_and_set_bit - Set a bit and return its old value
      51                 :            :  * @nr: Bit to set
      52                 :            :  * @addr: Address to count from
      53                 :            :  *
      54                 :            :  * This operation is non-atomic and can be reordered.
      55                 :            :  * If two examples of this operation race, one can appear to succeed
      56                 :            :  * but actually fail.  You must protect multiple accesses with a lock.
      57                 :            :  */
      58                 :            : static inline int __test_and_set_bit(int nr, volatile unsigned long *addr)
      59                 :            : {
      60                 :          3 :         unsigned long mask = BIT_MASK(nr);
      61                 :          3 :         unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
      62                 :          3 :         unsigned long old = *p;
      63                 :            : 
      64                 :          3 :         *p = old | mask;
      65                 :          3 :         return (old & mask) != 0;
      66                 :            : }
      67                 :            : 
      68                 :            : /**
      69                 :            :  * __test_and_clear_bit - Clear a bit and return its old value
      70                 :            :  * @nr: Bit to clear
      71                 :            :  * @addr: Address to count from
      72                 :            :  *
      73                 :            :  * This operation is non-atomic and can be reordered.
      74                 :            :  * If two examples of this operation race, one can appear to succeed
      75                 :            :  * but actually fail.  You must protect multiple accesses with a lock.
      76                 :            :  */
      77                 :            : static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr)
      78                 :            : {
      79                 :          3 :         unsigned long mask = BIT_MASK(nr);
      80                 :          3 :         unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
      81                 :          3 :         unsigned long old = *p;
      82                 :            : 
      83                 :          3 :         *p = old & ~mask;
      84                 :          3 :         return (old & mask) != 0;
      85                 :            : }
      86                 :            : 
      87                 :            : /* WARNING: non atomic and it can be reordered! */
      88                 :            : static inline int __test_and_change_bit(int nr,
      89                 :            :                                             volatile unsigned long *addr)
      90                 :            : {
      91                 :            :         unsigned long mask = BIT_MASK(nr);
      92                 :            :         unsigned long *p = ((unsigned long *)addr) + BIT_WORD(nr);
      93                 :            :         unsigned long old = *p;
      94                 :            : 
      95                 :            :         *p = old ^ mask;
      96                 :            :         return (old & mask) != 0;
      97                 :            : }
      98                 :            : 
      99                 :            : /**
     100                 :            :  * test_bit - Determine whether a bit is set
     101                 :            :  * @nr: bit number to test
     102                 :            :  * @addr: Address to start counting from
     103                 :            :  */
     104                 :          3 : static inline int test_bit(int nr, const volatile unsigned long *addr)
     105                 :            : {
     106                 :          3 :         return 1UL & (addr[BIT_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));
     107                 :            : }
     108                 :            : 
     109                 :            : #endif /* _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ */