mirror of https://gitee.com/openkylin/linux.git
58 lines
1.1 KiB
ArmAsm
58 lines
1.1 KiB
ArmAsm
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/*
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* linux/arch/arm26/lib/delay.S
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*
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* Copyright (C) 1995, 1996 Russell King
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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.text
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LC0: .word loops_per_jiffy
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/*
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* 0 <= r0 <= 2000
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*/
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ENTRY(udelay)
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mov r2, #0x6800
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orr r2, r2, #0x00db
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mul r1, r0, r2
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ldr r2, LC0
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ldr r2, [r2]
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mov r1, r1, lsr #11
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mov r2, r2, lsr #11
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mul r0, r1, r2
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movs r0, r0, lsr #6
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RETINSTR(moveq,pc,lr)
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/*
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* loops = (r0 * 0x10c6 * 100 * loops_per_jiffy) / 2^32
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*
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* Oh, if only we had a cycle counter...
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*/
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@ Delay routine
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ENTRY(__delay)
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subs r0, r0, #1
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#if 0
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RETINSTR(movls,pc,lr)
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subs r0, r0, #1
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RETINSTR(movls,pc,lr)
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subs r0, r0, #1
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RETINSTR(movls,pc,lr)
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subs r0, r0, #1
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RETINSTR(movls,pc,lr)
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subs r0, r0, #1
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RETINSTR(movls,pc,lr)
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subs r0, r0, #1
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RETINSTR(movls,pc,lr)
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subs r0, r0, #1
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RETINSTR(movls,pc,lr)
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subs r0, r0, #1
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#endif
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bhi __delay
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RETINSTR(mov,pc,lr)
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