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 | |
12 | void __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 | } |
31 | EXPORT_SYMBOL(__delay); |
32 | |
33 | inline 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 | } |
45 | EXPORT_SYMBOL(__const_udelay); |
46 | |
47 | void __udelay(unsigned long usecs) |
48 | { |
49 | __const_udelay(usecs * 0x000010c7); /* 2**32 / 1000000 (rounded up) */ |
50 | } |
51 | EXPORT_SYMBOL(__udelay); |
52 | |
53 | void __ndelay(unsigned long nsecs) |
54 | { |
55 | __const_udelay(nsecs * 0x00005); /* 2**32 / 1000000000 (rounded up) */ |
56 | } |
57 | EXPORT_SYMBOL(__ndelay); |
58 |