78 lines
1.5 KiB
C
78 lines
1.5 KiB
C
/* Copyright 2017 IBM Corp.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
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* implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef __CMPXCHG_H
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#define __CMPXCHG_H
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#ifndef __TEST__
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/*
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* Bare cmpxchg, no barriers.
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*/
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static inline uint32_t __cmpxchg32(uint32_t *mem, uint32_t old, uint32_t new)
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{
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uint32_t prev;
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asm volatile(
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"# __cmpxchg32 \n"
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"1: lwarx %0,0,%2 \n"
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" cmpw %0,%3 \n"
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" bne- 2f \n"
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" stwcx. %4,0,%2 \n"
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" bne- 1b \n"
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"2: \n"
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: "=&r"(prev), "+m"(*mem)
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: "r"(mem), "r"(old), "r"(new)
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: "cr0");
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return prev;
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}
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static inline uint64_t __cmpxchg64(uint64_t *mem, uint64_t old, uint64_t new)
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{
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uint64_t prev;
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asm volatile(
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"# __cmpxchg64 \n"
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"1: ldarx %0,0,%2 \n"
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" cmpd %0,%3 \n"
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" bne- 2f \n"
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" stdcx. %4,0,%2 \n"
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" bne- 1b \n"
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"2: \n"
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: "=&r"(prev), "+m"(*mem)
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: "r"(mem), "r"(old), "r"(new)
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: "cr0");
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return prev;
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}
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static inline uint32_t cmpxchg32(uint32_t *mem, uint32_t old, uint32_t new)
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{
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uint32_t prev;
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sync();
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prev = __cmpxchg32(mem, old,new);
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sync();
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return prev;
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}
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#endif /* __TEST_ */
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#endif /* __CMPXCHG_H */
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