mirror of https://gitee.com/openkylin/linux.git
52 lines
1.1 KiB
ArmAsm
52 lines
1.1 KiB
ArmAsm
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/*
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* linux/arch/unicore32/lib/delay.S
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*
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* Code specific to PKUnity SoC and UniCore ISA
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*
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* Copyright (C) 2001-2010 GUAN Xue-tao
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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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#include <asm/param.h>
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.text
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.LC0: .word loops_per_jiffy
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.LC1: .word (2199023*HZ)>>11
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/*
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* r0 <= 2000
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* lpj <= 0x01ffffff (max. 3355 bogomips)
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* HZ <= 1000
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*/
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ENTRY(__udelay)
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ldw r2, .LC1
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mul r0, r2, r0
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ENTRY(__const_udelay) @ 0 <= r0 <= 0x7fffff06
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ldw r2, .LC0
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ldw r2, [r2] @ max = 0x01ffffff
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mov r0, r0 >> #14 @ max = 0x0001ffff
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mov r2, r2 >> #10 @ max = 0x00007fff
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mul r0, r2, r0 @ max = 2^32-1
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mov.a r0, r0 >> #6
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cmoveq pc, lr
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/*
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* loops = r0 * HZ * loops_per_jiffy / 1000000
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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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sub.a r0, r0, #2
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bua __delay
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mov pc, lr
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ENDPROC(__udelay)
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ENDPROC(__const_udelay)
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ENDPROC(__delay)
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