49 lines
967 B
C
49 lines
967 B
C
/*
|
|
* Precise Delay Loops for x86-64
|
|
*
|
|
* Copyright (C) 1993 Linus Torvalds
|
|
* Copyright (C) 1997 Martin Mares <mj@atrey.karlin.mff.cuni.cz>
|
|
*
|
|
* The __delay function must _NOT_ be inlined as its execution time
|
|
* depends wildly on alignment on many x86 processors.
|
|
*/
|
|
|
|
#include <linux/config.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/delay.h>
|
|
#include <asm/delay.h>
|
|
|
|
#ifdef CONFIG_SMP
|
|
#include <asm/smp.h>
|
|
#endif
|
|
|
|
int x86_udelay_tsc = 0; /* Delay via TSC */
|
|
|
|
void __delay(unsigned long loops)
|
|
{
|
|
unsigned bclock, now;
|
|
|
|
rdtscl(bclock);
|
|
do
|
|
{
|
|
rep_nop();
|
|
rdtscl(now);
|
|
}
|
|
while((now-bclock) < loops);
|
|
}
|
|
|
|
inline void __const_udelay(unsigned long xloops)
|
|
{
|
|
__delay(((xloops * cpu_data[raw_smp_processor_id()].loops_per_jiffy) >> 32) * HZ);
|
|
}
|
|
|
|
void __udelay(unsigned long usecs)
|
|
{
|
|
__const_udelay(usecs * 0x000010c6); /* 2**32 / 1000000 */
|
|
}
|
|
|
|
void __ndelay(unsigned long nsecs)
|
|
{
|
|
__const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
|
|
}
|