46 lines
773 B
C
46 lines
773 B
C
|
/*
|
||
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
||
|
|
*
|
||
|
|
* Copyright (c) 2019 Western Digital Corporation or its affiliates.
|
||
|
|
*
|
||
|
|
* Authors:
|
||
|
|
* Anup Patel <anup.patel@wdc.com>
|
||
|
|
*/
|
||
|
|
|
||
|
|
#include <sbi/riscv_barrier.h>
|
||
|
|
#include <sbi/riscv_locks.h>
|
||
|
|
|
||
|
|
int spin_lock_check(spinlock_t *lock)
|
||
|
|
{
|
||
|
|
return (lock->lock == __RISCV_SPIN_UNLOCKED) ? 0 : 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
int spin_trylock(spinlock_t *lock)
|
||
|
|
{
|
||
|
|
int tmp = 1, busy;
|
||
|
|
|
||
|
|
__asm__ __volatile__(
|
||
|
|
" amoswap.w %0, %2, %1\n" RISCV_ACQUIRE_BARRIER
|
||
|
|
: "=r"(busy), "+A"(lock->lock)
|
||
|
|
: "r"(tmp)
|
||
|
|
: "memory");
|
||
|
|
|
||
|
|
return !busy;
|
||
|
|
}
|
||
|
|
|
||
|
|
void spin_lock(spinlock_t *lock)
|
||
|
|
{
|
||
|
|
while (1) {
|
||
|
|
if (spin_lock_check(lock))
|
||
|
|
continue;
|
||
|
|
|
||
|
|
if (spin_trylock(lock))
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
void spin_unlock(spinlock_t *lock)
|
||
|
|
{
|
||
|
|
__smp_store_release(&lock->lock, __RISCV_SPIN_UNLOCKED);
|
||
|
|
}
|