mirror of
https://github.com/torvalds/linux.git
synced 2024-11-15 08:31:55 +00:00
1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
59 lines
1.2 KiB
ArmAsm
59 lines
1.2 KiB
ArmAsm
/*
|
|
* linux/arch/arm/lib/delay.S
|
|
*
|
|
* Copyright (C) 1995, 1996 Russell King
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License version 2 as
|
|
* published by the Free Software Foundation.
|
|
*/
|
|
#include <linux/linkage.h>
|
|
#include <asm/assembler.h>
|
|
.text
|
|
|
|
LC0: .word loops_per_jiffy
|
|
|
|
/*
|
|
* 0 <= r0 <= 2000
|
|
*/
|
|
ENTRY(__udelay)
|
|
mov r2, #0x6800
|
|
orr r2, r2, #0x00db
|
|
mul r0, r2, r0
|
|
ENTRY(__const_udelay) @ 0 <= r0 <= 0x01ffffff
|
|
ldr r2, LC0
|
|
ldr r2, [r2] @ max = 0x0fffffff
|
|
mov r0, r0, lsr #11 @ max = 0x00003fff
|
|
mov r2, r2, lsr #11 @ max = 0x0003ffff
|
|
mul r0, r2, r0 @ max = 2^32-1
|
|
movs r0, r0, lsr #6
|
|
RETINSTR(moveq,pc,lr)
|
|
|
|
/*
|
|
* loops = (r0 * 0x10c6 * 100 * loops_per_jiffy) / 2^32
|
|
*
|
|
* Oh, if only we had a cycle counter...
|
|
*/
|
|
|
|
@ Delay routine
|
|
ENTRY(__delay)
|
|
subs r0, r0, #1
|
|
#if 0
|
|
RETINSTR(movls,pc,lr)
|
|
subs r0, r0, #1
|
|
RETINSTR(movls,pc,lr)
|
|
subs r0, r0, #1
|
|
RETINSTR(movls,pc,lr)
|
|
subs r0, r0, #1
|
|
RETINSTR(movls,pc,lr)
|
|
subs r0, r0, #1
|
|
RETINSTR(movls,pc,lr)
|
|
subs r0, r0, #1
|
|
RETINSTR(movls,pc,lr)
|
|
subs r0, r0, #1
|
|
RETINSTR(movls,pc,lr)
|
|
subs r0, r0, #1
|
|
#endif
|
|
bhi __delay
|
|
RETINSTR(mov,pc,lr)
|