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64 lines
No EOL
1.4 KiB
C
Vendored
64 lines
No EOL
1.4 KiB
C
Vendored
/* $OpenBSD: atomic.h,v 1.4 2022/08/29 02:01:18 jsg Exp $ */
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/* Public Domain */
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#ifndef _MACHINE_ATOMIC_H_
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#define _MACHINE_ATOMIC_H_
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#define __membar(_f) do { __asm volatile(_f ::: "memory"); } while (0)
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#define membar_enter() __membar("dmb sy")
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#define membar_exit() __membar("dmb sy")
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#define membar_producer() __membar("dmb st")
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#define membar_consumer() __membar("dmb ld")
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#define membar_sync() __membar("dmb sy")
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#if defined(_KERNEL)
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/* virtio needs MP membars even on SP kernels */
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#define virtio_membar_producer() __membar("dmb st")
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#define virtio_membar_consumer() __membar("dmb ld")
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#define virtio_membar_sync() __membar("dmb sy")
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/*
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* Set bits
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* *p = *p | v
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*/
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static inline void
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atomic_setbits_int(volatile unsigned int *p, unsigned int v)
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{
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unsigned int modified, tmp;
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__asm volatile (
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"1: ldxr %w0, [%x3] \n\t"
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" orr %w0, %w0, %w2 \n\t"
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" stxr %w1, %w0, [%x3] \n\t"
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" cbnz %w1, 1b \n\t"
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: "=&r" (tmp), "=&r" (modified)
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: "r" (v), "r" (p)
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: "memory", "cc"
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);
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}
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/*
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* Clear bits
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* *p = *p & (~v)
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*/
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static inline void
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atomic_clearbits_int(volatile unsigned int *p, unsigned int v)
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{
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unsigned int modified, tmp;
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__asm volatile (
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"1: ldxr %w0, [%x3] \n\t"
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" bic %w0, %w0, %w2 \n\t"
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" stxr %w1, %w0, [%x3] \n\t"
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" cbnz %w1, 1b \n\t"
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: "=&r" (tmp), "=&r" (modified)
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: "r" (v), "r" (p)
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: "memory", "cc"
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);
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}
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#endif /* defined(_KERNEL) */
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#endif /* _MACHINE_ATOMIC_H_ */ |