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-rw-r--r--arch/i386/lib/delay.c49
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/i386/lib/delay.c b/arch/i386/lib/delay.c
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1/*
2 * Precise Delay Loops for i386
3 *
4 * Copyright (C) 1993 Linus Torvalds
5 * Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
6 *
7 * The __delay function must _NOT_ be inlined as its execution time
8 * depends wildly on alignment on many x86 processors. The additional
9 * jump magic is needed to get the timing stable on all the CPU's
10 * we have to worry about.
11 */
12
13#include <linux/config.h>
14#include <linux/sched.h>
15#include <linux/delay.h>
16#include <asm/processor.h>
17#include <asm/delay.h>
18#include <asm/timer.h>
19
20#ifdef CONFIG_SMP
21#include <asm/smp.h>
22#endif
23
24extern struct timer_opts* timer;
25
26void __delay(unsigned long loops)
27{
28 cur_timer->delay(loops);
29}
30
31inline void __const_udelay(unsigned long xloops)
32{
33 int d0;
34 xloops *= 4;
35 __asm__("mull %0"
36 :"=d" (xloops), "=&a" (d0)
37 :"1" (xloops),"0" (cpu_data[_smp_processor_id()].loops_per_jiffy * (HZ/4)));
38 __delay(++xloops);
39}
40
41void __udelay(unsigned long usecs)
42{
43 __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
44}
45
46void __ndelay(unsigned long nsecs)
47{
48 __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
49}