You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
111 lines
3.1 KiB
111 lines
3.1 KiB
#ifndef _ASM_GENERIC_BITOPS_NON_ATOMIC_H_
|
|
#define _ASM_GENERIC_BITOPS_NON_ATOMIC_H_
|
|
|
|
#include <asm/types.h>
|
|
|
|
#define BITOP_MASK(nr) (1UL << ((nr) % BITS_PER_LONG))
|
|
#define BITOP_WORD(nr) ((nr) / BITS_PER_LONG)
|
|
|
|
/**
|
|
* __set_bit - Set a bit in memory
|
|
* @nr: the bit to set
|
|
* @addr: the address to start counting from
|
|
*
|
|
* Unlike set_bit(), this function is non-atomic and may be reordered.
|
|
* If it's called on the same region of memory simultaneously, the effect
|
|
* may be that only one operation succeeds.
|
|
*/
|
|
static inline void __set_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
unsigned long mask = BITOP_MASK(nr);
|
|
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
|
|
|
|
*p |= mask;
|
|
}
|
|
|
|
static inline void __clear_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
unsigned long mask = BITOP_MASK(nr);
|
|
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
|
|
|
|
*p &= ~mask;
|
|
}
|
|
|
|
/**
|
|
* __change_bit - Toggle a bit in memory
|
|
* @nr: the bit to change
|
|
* @addr: the address to start counting from
|
|
*
|
|
* Unlike change_bit(), this function is non-atomic and may be reordered.
|
|
* If it's called on the same region of memory simultaneously, the effect
|
|
* may be that only one operation succeeds.
|
|
*/
|
|
static inline void __change_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
unsigned long mask = BITOP_MASK(nr);
|
|
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
|
|
|
|
*p ^= mask;
|
|
}
|
|
|
|
/**
|
|
* __test_and_set_bit - Set a bit and return its old value
|
|
* @nr: Bit to set
|
|
* @addr: Address to count from
|
|
*
|
|
* This operation is non-atomic and can be reordered.
|
|
* If two examples of this operation race, one can appear to succeed
|
|
* but actually fail. You must protect multiple accesses with a lock.
|
|
*/
|
|
static inline int __test_and_set_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
unsigned long mask = BITOP_MASK(nr);
|
|
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
|
|
unsigned long old = *p;
|
|
|
|
*p = old | mask;
|
|
return (old & mask) != 0;
|
|
}
|
|
|
|
/**
|
|
* __test_and_clear_bit - Clear a bit and return its old value
|
|
* @nr: Bit to clear
|
|
* @addr: Address to count from
|
|
*
|
|
* This operation is non-atomic and can be reordered.
|
|
* If two examples of this operation race, one can appear to succeed
|
|
* but actually fail. You must protect multiple accesses with a lock.
|
|
*/
|
|
static inline int __test_and_clear_bit(int nr, volatile unsigned long *addr)
|
|
{
|
|
unsigned long mask = BITOP_MASK(nr);
|
|
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
|
|
unsigned long old = *p;
|
|
|
|
*p = old & ~mask;
|
|
return (old & mask) != 0;
|
|
}
|
|
|
|
/* WARNING: non atomic and it can be reordered! */
|
|
static inline int __test_and_change_bit(int nr,
|
|
volatile unsigned long *addr)
|
|
{
|
|
unsigned long mask = BITOP_MASK(nr);
|
|
unsigned long *p = ((unsigned long *)addr) + BITOP_WORD(nr);
|
|
unsigned long old = *p;
|
|
|
|
*p = old ^ mask;
|
|
return (old & mask) != 0;
|
|
}
|
|
|
|
/**
|
|
* test_bit - Determine whether a bit is set
|
|
* @nr: bit number to test
|
|
* @addr: Address to start counting from
|
|
*/
|
|
static inline int test_bit(int nr, const volatile unsigned long *addr)
|
|
{
|
|
return 1UL & (addr[BITOP_WORD(nr)] >> (nr & (BITS_PER_LONG-1)));
|
|
}
|
|
|
|
#endif /* _ASM_GENERIC_BITOPS_NON_ATOMIC_H_ */
|
|
|