1 /* 2 * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved. 3 * Copyright (c) 2014, 2019, Red Hat Inc. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #ifndef OS_CPU_LINUX_AARCH64_ATOMIC_LINUX_AARCH64_HPP 27 #define OS_CPU_LINUX_AARCH64_ATOMIC_LINUX_AARCH64_HPP 28 29 #include "runtime/vm_version.hpp" 30 31 // Implementation of class atomic 32 // Note that memory_order_conservative requires a full barrier after atomic stores. 33 // See https://patchwork.kernel.org/patch/3575821/ 34 35 #define FULL_MEM_BARRIER __sync_synchronize() 36 #define READ_MEM_BARRIER __atomic_thread_fence(__ATOMIC_ACQUIRE); 37 #define WRITE_MEM_BARRIER __atomic_thread_fence(__ATOMIC_RELEASE); 38 39 template<size_t byte_size> 40 struct Atomic::PlatformAdd 41 : Atomic::AddAndFetch<Atomic::PlatformAdd<byte_size> > 42 { 43 template<typename I, typename D> 44 D add_and_fetch(I add_value, D volatile* dest, atomic_memory_order order) const { 45 D res = __atomic_add_fetch(dest, add_value, __ATOMIC_RELEASE); 46 FULL_MEM_BARRIER; 47 return res; 48 } 49 }; 50 51 template<size_t byte_size> 52 template<typename T> 53 inline T Atomic::PlatformXchg<byte_size>::operator()(T exchange_value, 54 T volatile* dest, 55 atomic_memory_order order) const { 56 STATIC_ASSERT(byte_size == sizeof(T)); 57 T res = __atomic_exchange_n(dest, exchange_value, __ATOMIC_RELEASE); 58 FULL_MEM_BARRIER; 59 return res; 60 } 61 62 template<size_t byte_size> 63 template<typename T> 64 inline T Atomic::PlatformCmpxchg<byte_size>::operator()(T exchange_value, 65 T volatile* dest, 66 T compare_value, 67 atomic_memory_order order) const { 68 STATIC_ASSERT(byte_size == sizeof(T)); 69 if (order == memory_order_relaxed) { 70 T value = compare_value; 71 __atomic_compare_exchange(dest, &value, &exchange_value, /*weak*/false, 72 __ATOMIC_RELAXED, __ATOMIC_RELAXED); 73 return value; 74 } else { 75 T value = compare_value; 76 FULL_MEM_BARRIER; 77 __atomic_compare_exchange(dest, &value, &exchange_value, /*weak*/false, 78 __ATOMIC_RELAXED, __ATOMIC_RELAXED); 79 FULL_MEM_BARRIER; 80 return value; 81 } 82 } 83 84 #endif // OS_CPU_LINUX_AARCH64_ATOMIC_LINUX_AARCH64_HPP