| // Licensed to the Apache Software Foundation (ASF) under one |
| // or more contributor license agreements. See the NOTICE file |
| // distributed with this work for additional information |
| // regarding copyright ownership. The ASF licenses this file |
| // to you 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.. |
| |
| #include "spinlock.h" |
| |
| static inline void _mm_pause(void) __attribute__((always_inline)); |
| static inline int _InterlockedExchange(int volatile *dst, int val) __attribute__((always_inline)); |
| |
| static inline void _mm_pause(void) /* definition requires -ffreestanding */ |
| { |
| __asm __volatile( |
| "pause" |
| ); |
| } |
| |
| static inline int _InterlockedExchange(int volatile *dst, int val) |
| { |
| int res; |
| __asm __volatile( |
| "lock xchg %2, %1;" |
| "mov %2, %0" |
| : "=m" (res) |
| : "m" (*dst), |
| "r" (val) |
| : "memory" |
| ); |
| return (res); |
| |
| } |
| |
| uint32_t sgx_spin_lock(sgx_spinlock_t *lock) |
| { |
| while(_InterlockedExchange((volatile int *)lock, 1) != 0) { |
| while (*lock) { |
| /* tell cpu we are spinning */ |
| _mm_pause(); |
| } |
| } |
| return (0); |
| } |
| |
| uint32_t sgx_spin_unlock(sgx_spinlock_t *lock) |
| { |
| *lock = 0; |
| return (0); |
| } |
| |