1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) 2011 Richard Weinberger <richrd@nod.at>
4 * Mostly copied from arch/x86/lib/delay.c
5 */
6
7#include <linux/export.h>
8#include <linux/kernel.h>
9#include <linux/delay.h>
10#include <asm/param.h>
11
12void __delay(unsigned long loops)
13{
14	asm volatile(
15		"test %0,%0\n"
16		"jz 3f\n"
17		"jmp 1f\n"
18
19		".align 16\n"
20		"1: jmp 2f\n"
21
22		".align 16\n"
23		"2: dec %0\n"
24		" jnz 2b\n"
25		"3: dec %0\n"
26
27		: /* we don't need output */
28		: "a" (loops)
29	);
30}
31EXPORT_SYMBOL(__delay);
32
33inline void __const_udelay(unsigned long xloops)
34{
35	int d0;
36
37	xloops *= 4;
38	asm("mull %%edx"
39		: "=d" (xloops), "=&a" (d0)
40		: "1" (xloops), "0"
41		(loops_per_jiffy * (HZ/4)));
42
43	__delay(++xloops);
44}
45EXPORT_SYMBOL(__const_udelay);
46
47void __udelay(unsigned long usecs)
48{
49	__const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */
50}
51EXPORT_SYMBOL(__udelay);
52
53void __ndelay(unsigned long nsecs)
54{
55	__const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */
56}
57EXPORT_SYMBOL(__ndelay);
58