59 строки
1.2 KiB
C
59 строки
1.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* OpenRISC Linux
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*
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* Linux architectural port borrowing liberally from similar works of
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* others. All original copyrights apply as per the original source
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* declaration.
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*
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* Modifications for the OpenRISC architecture:
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* Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
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*
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* Precise Delay Loops
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*/
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#include <linux/kernel.h>
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#include <linux/export.h>
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#include <linux/init.h>
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#include <asm/param.h>
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#include <asm/delay.h>
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#include <asm/timex.h>
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#include <asm/processor.h>
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int read_current_timer(unsigned long *timer_value)
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{
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*timer_value = get_cycles();
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return 0;
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}
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void __delay(unsigned long cycles)
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{
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cycles_t start = get_cycles();
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while ((get_cycles() - start) < cycles)
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cpu_relax();
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}
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EXPORT_SYMBOL(__delay);
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inline void __const_udelay(unsigned long xloops)
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{
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unsigned long long loops;
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loops = (unsigned long long)xloops * loops_per_jiffy * HZ;
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__delay(loops >> 32);
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}
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EXPORT_SYMBOL(__const_udelay);
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void __udelay(unsigned long usecs)
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{
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__const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */
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}
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EXPORT_SYMBOL(__udelay);
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void __ndelay(unsigned long nsecs)
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{
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__const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */
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}
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EXPORT_SYMBOL(__ndelay);
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