81 lines
1.6 KiB
C
81 lines
1.6 KiB
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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#ifndef SPINLOCK_H
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#define SPINLOCK_H
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#ifndef ASSEMBLER
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#include <types.h>
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/** The architecture dependent spinlock type. */
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typedef struct _spinlock {
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uint32_t head;
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uint32_t tail;
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} spinlock_t;
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/* Function prototypes */
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void spinlock_init(spinlock_t *lock);
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void spinlock_obtain(spinlock_t *lock);
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static inline void spinlock_release(spinlock_t *lock)
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{
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/* Increment tail of queue */
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asm volatile (" lock incl %[tail]\n"
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:
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: [tail] "m" (lock->tail)
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: "cc", "memory");
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}
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#else /* ASSEMBLER */
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/** The offset of the head element. */
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#define SYNC_SPINLOCK_HEAD_OFFSET 0
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/** The offset of the tail element. */
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#define SYNC_SPINLOCK_TAIL_OFFSET 4
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.macro spinlock_obtain lock
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movl $1, % eax
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lea \lock, % rbx
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lock xaddl % eax, SYNC_SPINLOCK_HEAD_OFFSET(%rbx)
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cmpl % eax, SYNC_SPINLOCK_TAIL_OFFSET(%rbx)
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jz 1f
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2 :
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pause
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cmpl % eax, SYNC_SPINLOCK_TAIL_OFFSET(%rbx)
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jnz 2b
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1 :
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.endm
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#define spinlock_obtain(x) spinlock_obtain lock = (x)
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.macro spinlock_release lock
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lea \lock, % rbx
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lock incl SYNC_SPINLOCK_TAIL_OFFSET(%rbx)
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.endm
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#define spinlock_release(x) spinlock_release lock = (x)
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#endif /* ASSEMBLER */
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#define spinlock_rflags unsigned long cpu_int_value
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#define spinlock_irqsave_obtain(l) \
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do { \
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CPU_INT_ALL_DISABLE(); \
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spinlock_obtain(l); \
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} while (0)
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#define spinlock_irqrestore_release(l) \
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do { \
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spinlock_release(l); \
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CPU_INT_ALL_RESTORE(); \
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} while (0)
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#endif /* SPINLOCK_H */
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