44 строки
1.0 KiB
C
44 строки
1.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
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*/
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#include <linux/delay.h>
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#include <linux/export.h>
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#include <linux/smp.h>
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#include <linux/timex.h>
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#include <asm/compiler.h>
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#include <asm/processor.h>
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void __delay(unsigned long cycles)
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{
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u64 t0 = get_cycles();
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while ((unsigned long)(get_cycles() - t0) < cycles)
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cpu_relax();
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}
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EXPORT_SYMBOL(__delay);
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/*
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* Division by multiplication: you don't have to worry about
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* loss of precision.
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*
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* Use only for very small delays ( < 1 msec). Should probably use a
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* lookup table, really, as the multiplications take much too long with
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* short delays. This is a "reasonable" implementation, though (and the
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* first constant multiplications gets optimized away if the delay is
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* a constant)
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*/
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void __udelay(unsigned long us)
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{
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__delay((us * 0x000010c7ull * HZ * lpj_fine) >> 32);
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}
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EXPORT_SYMBOL(__udelay);
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void __ndelay(unsigned long ns)
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{
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__delay((ns * 0x00000005ull * HZ * lpj_fine) >> 32);
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}
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EXPORT_SYMBOL(__ndelay);
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