diff options
| author | Atish Patra <atish.patra@wdc.com> | 2019-06-18 14:54:01 -0700 |
|---|---|---|
| committer | Anup Patel <anup.patel@wdc.com> | 2019-06-19 09:48:51 +0530 |
| commit | 749b0b093242a4c27f7c4f66121afd7852b2de48 (patch) | |
| tree | 90c46fe6e750ddf08dd57347ddd498571792353a /lib/sbi/riscv_locks.c | |
| parent | a5b37bd7d275fc65d8fd0b19bd3a08edfe4e6096 (diff) | |
lib: Move sbi core library to lib/sbi
Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Anup Patel <anup.patel@wdc.com>
Diffstat (limited to 'lib/sbi/riscv_locks.c')
| -rw-r--r-- | lib/sbi/riscv_locks.c | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/lib/sbi/riscv_locks.c b/lib/sbi/riscv_locks.c new file mode 100644 index 0000000..4d1d9c0 --- /dev/null +++ b/lib/sbi/riscv_locks.c @@ -0,0 +1,45 @@ +/* + * 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); +} |