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977c4b20b5
MISRA C required that return value should be used, missing for it should add "(void)" prefix before the function call. Some function can be declared without return value to avoid this problem. Signed-off-by: Huihuang Shi <huihuang.shi@intel.com> Acked-by: Eddie Dong <eddie.dong@intel.com>
34 lines
788 B
C
34 lines
788 B
C
/*
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* Copyright (C) 2018 Intel Corporation. All rights reserved.
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*
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* SPDX-License-Identifier: BSD-3-Clause
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*/
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#include <hv_lib.h>
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inline void spinlock_init(spinlock_t *lock)
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{
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memset(lock, 0, sizeof(spinlock_t));
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}
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void spinlock_obtain(spinlock_t *lock)
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{
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/* The lock function atomically increments and exchanges the head
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* counter of the queue. If the old head of the queue is equal to the
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* tail, we have locked the spinlock. Otherwise we have to wait.
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*/
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asm volatile (" lock xaddl %%eax,%[head]\n"
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" cmpl %%eax,%[tail]\n"
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" jz 1f\n"
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"2: pause\n"
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" cmpl %%eax,%[tail]\n"
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" jnz 2b\n"
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"1:\n"
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:
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: "a" (1),
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[head] "m"(lock->head),
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[tail] "m"(lock->tail)
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: "cc", "memory");
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}
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