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/* Copyright 2017 IBM Corp.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#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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