43 lines
1019 B
C
43 lines
1019 B
C
|
// SPDX-License-Identifier: GPL-2.0
|
||
|
|
/*
|
||
|
|
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
|
||
|
|
*/
|
||
|
|
#include <linux/delay.h>
|
||
|
|
#include <linux/export.h>
|
||
|
|
#include <linux/smp.h>
|
||
|
|
#include <linux/timex.h>
|
||
|
|
|
||
|
|
#include <asm/processor.h>
|
||
|
|
|
||
|
|
void __delay(unsigned long cycles)
|
||
|
|
{
|
||
|
|
u64 t0 = get_cycles();
|
||
|
|
|
||
|
|
while ((unsigned long)(get_cycles() - t0) < cycles)
|
||
|
|
cpu_relax();
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL(__delay);
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Division by multiplication: you don't have to worry about
|
||
|
|
* loss of precision.
|
||
|
|
*
|
||
|
|
* Use only for very small delays ( < 1 msec). Should probably use a
|
||
|
|
* lookup table, really, as the multiplications take much too long with
|
||
|
|
* short delays. This is a "reasonable" implementation, though (and the
|
||
|
|
* first constant multiplications gets optimized away if the delay is
|
||
|
|
* a constant)
|
||
|
|
*/
|
||
|
|
|
||
|
|
void __udelay(unsigned long us)
|
||
|
|
{
|
||
|
|
__delay((us * 0x000010c7ull * HZ * lpj_fine) >> 32);
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL(__udelay);
|
||
|
|
|
||
|
|
void __ndelay(unsigned long ns)
|
||
|
|
{
|
||
|
|
__delay((ns * 0x00000005ull * HZ * lpj_fine) >> 32);
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL(__ndelay);
|