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// SPDX-License-Identifier: Apache-2.0
/* Copyright 2017 IBM Corp. */
#ifndef __CMPXCHG_H
#define __CMPXCHG_H
#ifndef __TEST__
/*
* Bare cmpxchg, no barriers.
*/
static inline uint32_t __cmpxchg32(uint32_t *mem, uint32_t old, uint32_t new)
{
uint32_t prev;
asm volatile(
"# __cmpxchg32 \n"
"1: lwarx %0,0,%2 \n"
" cmpw %0,%3 \n"
" bne- 2f \n"
" stwcx. %4,0,%2 \n"
" bne- 1b \n"
"2: \n"
: "=&r"(prev), "+m"(*mem)
: "r"(mem), "r"(old), "r"(new)
: "cr0");
return prev;
}
static inline uint64_t __cmpxchg64(uint64_t *mem, uint64_t old, uint64_t new)
{
uint64_t prev;
asm volatile(
"# __cmpxchg64 \n"
"1: ldarx %0,0,%2 \n"
" cmpd %0,%3 \n"
" bne- 2f \n"
" stdcx. %4,0,%2 \n"
" bne- 1b \n"
"2: \n"
: "=&r"(prev), "+m"(*mem)
: "r"(mem), "r"(old), "r"(new)
: "cr0");
return prev;
}
static inline uint32_t cmpxchg32(uint32_t *mem, uint32_t old, uint32_t new)
{
uint32_t prev;
sync();
prev = __cmpxchg32(mem, old,new);
sync();
return prev;
}
#endif /* __TEST_ */
#endif /* __CMPXCHG_H */
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