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um: clean up delay functions

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Both sys-i386 and sys-x86_64 support now ndelay().  The delay functions
are based on arch/x86/lib/delay.c.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Richard Weinberger 2011-07-25 17:12:46 -07:00 committed by Linus Torvalds
parent c0ce5b6734
commit 22e9b917ab
3 changed files with 93 additions and 34 deletions
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10
arch/um/include/asm/delay.h
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@ -1,20 +1,18 @@
#ifndef __UM_DELAY_H
#define __UM_DELAY_H
#define MILLION 1000000
/* Undefined on purpose */
extern void __bad_udelay(void);
extern void __bad_ndelay(void);
extern void __udelay(unsigned long usecs);
extern void __ndelay(unsigned long usecs);
extern void __delay(unsigned long loops);
#define udelay(n) ((__builtin_constant_p(n) && (n) > 20000) ? \
__bad_udelay() : __udelay(n))
/* It appears that ndelay is not used at all for UML, and has never been
* implemented. */
extern void __unimplemented_ndelay(void);
#define ndelay(n) __unimplemented_ndelay()
#define ndelay(n) ((__builtin_constant_p(n) && (n) > 20000) ? \
__bad_ndelay() : __ndelay(n))
#endif

61
arch/um/sys-i386/delay.c
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@ -1,29 +1,60 @@
/*
* Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
* Mostly copied from arch/x86/lib/delay.c
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <asm/param.h>
void __delay(unsigned long time)
void __delay(unsigned long loops)
{
/* Stolen from the i386 __loop_delay */
int d0;
__asm__ __volatile__(
"\tjmp 1f\n"
asm volatile(
"test %0,%0\n"
"jz 3f\n"
"jmp 1f\n"
".align 16\n"
"1:\tjmp 2f\n"
"1: jmp 2f\n"
".align 16\n"
"2:\tdecl %0\n\tjns 2b"
:"=&a" (d0)
:"0" (time));
"2: dec %0\n"
" jnz 2b\n"
"3: dec %0\n"
: /* we don't need output */
: "a" (loops)
);
}
EXPORT_SYMBOL(__delay);
inline void __const_udelay(unsigned long xloops)
{
int d0;
xloops *= 4;
asm("mull %%edx"
: "=d" (xloops), "=&a" (d0)
: "1" (xloops), "0"
(loops_per_jiffy * (HZ/4)));
__delay(++xloops);
}
EXPORT_SYMBOL(__const_udelay);
void __udelay(unsigned long usecs)
{
int i, n;
n = (loops_per_jiffy * HZ * usecs) / MILLION;
for(i=0;i<n;i++)
cpu_relax();
__const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
}
EXPORT_SYMBOL(__udelay);
void __ndelay(unsigned long nsecs)
{
__const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
}
EXPORT_SYMBOL(__ndelay);

56
arch/um/sys-x86_64/delay.c
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@ -1,30 +1,60 @@
/*
* Copyright 2003 PathScale, Inc.
* Copied from arch/x86_64
* Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
* Mostly copied from arch/x86/lib/delay.c
*
* Licensed under the GPL
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/delay.h>
#include <asm/processor.h>
#include <asm/param.h>
void __delay(unsigned long loops)
{
unsigned long i;
asm volatile(
"test %0,%0\n"
"jz 3f\n"
"jmp 1f\n"
for(i = 0; i < loops; i++)
cpu_relax();
".align 16\n"
"1: jmp 2f\n"
".align 16\n"
"2: dec %0\n"
" jnz 2b\n"
"3: dec %0\n"
: /* we don't need output */
: "a" (loops)
);
}
EXPORT_SYMBOL(__delay);
inline void __const_udelay(unsigned long xloops)
{
int d0;
xloops *= 4;
asm("mull %%edx"
: "=d" (xloops), "=&a" (d0)
: "1" (xloops), "0"
(loops_per_jiffy * (HZ/4)));
__delay(++xloops);
}
EXPORT_SYMBOL(__const_udelay);
void __udelay(unsigned long usecs)
{
unsigned long i, n;
n = (loops_per_jiffy * HZ * usecs) / MILLION;
for(i=0;i<n;i++)
cpu_relax();
__const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
}
EXPORT_SYMBOL(__udelay);
void __ndelay(unsigned long nsecs)
{
__const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
}
EXPORT_SYMBOL(__ndelay);