49 lines
1.2 KiB
C
49 lines
1.2 KiB
C
/*
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* arch/sh/lib64/udelay.c
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*
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* Delay routines, using a pre-computed "loops_per_jiffy" value.
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*
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* Copyright (C) 2000, 2001 Paolo Alberelli
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* Copyright (C) 2003, 2004 Paul Mundt
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/sched.h>
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#include <asm/param.h>
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/*
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* Use only for very small delays (< 1 msec).
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*
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* The active part of our cycle counter is only 32-bits wide, and
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* we're treating the difference between two marks as signed. On
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* a 1GHz box, that's about 2 seconds.
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*/
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void __delay(unsigned long loops)
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{
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long long dummy;
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__asm__ __volatile__("gettr tr0, %1\n\t"
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"pta $+4, tr0\n\t"
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"addi %0, -1, %0\n\t"
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"bne %0, r63, tr0\n\t"
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"ptabs %1, tr0\n\t":"=r"(loops),
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"=r"(dummy)
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:"0"(loops));
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}
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inline void __const_udelay(unsigned long xloops)
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{
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__delay(xloops * (HZ * cpu_data[raw_smp_processor_id()].loops_per_jiffy));
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}
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void __udelay(unsigned long usecs)
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{
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__const_udelay(usecs * 0x000010c6); /* 2**32 / 1000000 */
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}
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void __ndelay(unsigned long nsecs)
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{
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__const_udelay(nsecs * 0x00000005);
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}
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