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- /*
- * 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);
- }
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