linux/arch/sh/lib64/udelay.c

57 lines
1.4 KiB
C
Raw Normal View History

/*
* arch/sh/lib64/udelay.c
*
* Delay routines, using a pre-computed "loops_per_jiffy" value.
*
* Copyright (C) 2000, 2001 Paolo Alberelli
* Copyright (C) 2003, 2004 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#include <linux/sched.h>
#include <asm/param.h>
/*
* Use only for very small delays (< 1 msec).
*
* The active part of our cycle counter is only 32-bits wide, and
* we're treating the difference between two marks as signed. On
* a 1GHz box, that's about 2 seconds.
*/
void __delay(int loops)
{
long long dummy;
__asm__ __volatile__("gettr tr0, %1\n\t"
"pta $+4, tr0\n\t"
"addi %0, -1, %0\n\t"
"bne %0, r63, tr0\n\t"
"ptabs %1, tr0\n\t":"=r"(loops),
"=r"(dummy)
:"0"(loops));
}
void __udelay(unsigned long long usecs, unsigned long lpj)
{
usecs *= (((unsigned long long) HZ << 32) / 1000000) * lpj;
__delay((long long) usecs >> 32);
}
void __ndelay(unsigned long long nsecs, unsigned long lpj)
{
nsecs *= (((unsigned long long) HZ << 32) / 1000000000) * lpj;
__delay((long long) nsecs >> 32);
}
void udelay(unsigned long usecs)
{
__udelay(usecs, cpu_data[raw_smp_processor_id()].loops_per_jiffy);
}
void ndelay(unsigned long nsecs)
{
__ndelay(nsecs, cpu_data[raw_smp_processor_id()].loops_per_jiffy);
}