corda/sdk/tlibc/gen/spinlock.c
Angie Chinchilla 9441de4c38 Initial release of Intel SGX for Linux.
This release is used in conjunction with the linux-sgx-driver Intial release:
https://github.com/01org/linux-sgx-driver
commit-id: 0e865ce5e6b297a787bcdc12d98bada8174be6d7

Intel-id: 33399

Signed-off-by: Angie Chinchilla <angie.v.chinchilla@intel.com>
2016-06-23 18:51:53 -04:00

80 lines
2.4 KiB
C

/*
* Copyright (C) 2011-2016 Intel Corporation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*/
#include <sgx_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)
{
__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);
}