1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef _ATOMIC_H_ 18 #define _ATOMIC_H_ 19 20 #ifdef __cplusplus 21 extern "C" { 22 #endif 23 24 #include <stdint.h> 25 #include <stdbool.h> 26 27 /* almost all platforms support byte and 32-bit operations of this sort. please do not add other sizes here */ 28 uint32_t atomicXchgByte(volatile uint8_t *byte, uint32_t newVal); 29 uint32_t atomicXchg32bits(volatile uint32_t *word, uint32_t newVal); 30 bool atomicCmpXchgByte(volatile uint8_t *byte, uint32_t prevVal, uint32_t newVal); 31 bool atomicCmpXchg32bits(volatile uint32_t *word, uint32_t prevVal, uint32_t newVal); 32 33 //returns old value 34 uint32_t atomicAddByte(volatile uint8_t *byte, uint32_t addend); 35 uint32_t atomicAdd32bits(volatile uint32_t *word, uint32_t addend); 36 37 // pull in inline cpu-specific implementations, if any 38 #include <cpu/atomic.h> 39 #include <cpu/barrier.h> 40 41 //writes with barriers 42 static inline uint32_t atomicReadByte(volatile uint8_t *byte) 43 { 44 mem_reorder_barrier(); 45 return *byte; 46 } 47 48 static inline uint32_t atomicRead32bits(volatile uint32_t *word) 49 { 50 mem_reorder_barrier(); 51 return *word; 52 } 53 54 static inline void atomicWriteByte(volatile uint8_t *byte, uint32_t val) 55 { 56 *byte = val; 57 mem_reorder_barrier(); 58 } 59 60 static inline void atomicWrite32bits(volatile uint32_t *word, uint32_t val) 61 { 62 *word = val; 63 mem_reorder_barrier(); 64 } 65 66 #ifdef __cplusplus 67 } 68 #endif 69 70 #endif 71
