This patch implements low-level uaccess libraries. Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn> Acked-by: Arnd Bergmann <arnd@arndb.de>
		
			
				
	
	
		
			214 lines
		
	
	
	
		
			4.6 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			214 lines
		
	
	
	
		
			4.6 KiB
			
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
/*
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 * linux/arch/unicore32/lib/copy_template.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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/*
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 * Theory of operation
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 * -------------------
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 *
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 * This file provides the core code for a forward memory copy used in
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 * the implementation of memcopy(), copy_to_user() and copy_from_user().
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 *
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 * The including file must define the following accessor macros
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 * according to the need of the given function:
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 *
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 * ldr1w ptr reg abort
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 *
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 *	This loads one word from 'ptr', stores it in 'reg' and increments
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 *	'ptr' to the next word. The 'abort' argument is used for fixup tables.
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 *
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 * ldr4w ptr reg1 reg2 reg3 reg4 abort
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 * ldr8w ptr, reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
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 *
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 *	This loads four or eight words starting from 'ptr', stores them
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 *	in provided registers and increments 'ptr' past those words.
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 *	The'abort' argument is used for fixup tables.
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 *
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 * ldr1b ptr reg cond abort
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 *
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 *	Similar to ldr1w, but it loads a byte and increments 'ptr' one byte.
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 *	It also must apply the condition code if provided, otherwise the
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 *	"al" condition is assumed by default.
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 *
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 * str1w ptr reg abort
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 * str8w ptr reg1 reg2 reg3 reg4 reg5 reg6 reg7 reg8 abort
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 * str1b ptr reg cond abort
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 *
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 *	Same as their ldr* counterparts, but data is stored to 'ptr' location
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 *	rather than being loaded.
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 *
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 * enter
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 *
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 *	Preserve the provided registers on the stack plus any additional
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 *	data as needed by the implementation including this code. Called
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 *	upon code entry.
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 *
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 * exit
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 *
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 *	Restore registers with the values previously saved with the
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 *	'preserv' macro. Called upon code termination.
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 */
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		enter
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		sub.a	r2, r2, #4
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		bsl	8f
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		and.a	ip, r0, #3
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		bne	9f
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		and.a	ip, r1, #3
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		bne	10f
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1:		sub.a	r2, r2, #(28)
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		stm.w	(r5 - r8), [sp-]
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		bsl	5f
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3:
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4:		ldr8w	r1, r3, r4, r5, r6, r7, r8, r10, r11, abort=20f
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		sub.a	r2, r2, #32
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		str8w	r0, r3, r4, r5, r6, r7, r8, r10, r11, abort=20f
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		beg	3b
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5:		and.a	ip, r2, #28
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		rsub	ip, ip, #32
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		beq	7f
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		add	pc, pc, ip		@ C is always clear here
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		nop
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		ldr1w	r1, r3, abort=20f
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		ldr1w	r1, r4, abort=20f
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		ldr1w	r1, r5, abort=20f
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		ldr1w	r1, r6, abort=20f
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		ldr1w	r1, r7, abort=20f
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		ldr1w	r1, r8, abort=20f
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		ldr1w	r1, r11, abort=20f
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		add	pc, pc, ip
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		nop
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		str1w	r0, r3, abort=20f
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		str1w	r0, r4, abort=20f
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		str1w	r0, r5, abort=20f
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		str1w	r0, r6, abort=20f
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		str1w	r0, r7, abort=20f
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		str1w	r0, r8, abort=20f
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		str1w	r0, r11, abort=20f
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7:		ldm.w	(r5 - r8), [sp]+
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8:		mov.a	r2, r2 << #31
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		ldr1b	r1, r3, ne, abort=21f
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		ldr1b	r1, r4, ea, abort=21f
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		ldr1b	r1, r10, ea, abort=21f
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		str1b	r0, r3, ne, abort=21f
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		str1b	r0, r4, ea, abort=21f
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		str1b	r0, r10, ea, abort=21f
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		exit
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9:		rsub	ip, ip, #4
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		csub.a	ip, #2
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		ldr1b	r1, r3, sg, abort=21f
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		ldr1b	r1, r4, eg, abort=21f
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		ldr1b	r1, r11, abort=21f
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		str1b	r0, r3, sg, abort=21f
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		str1b	r0, r4, eg, abort=21f
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		sub.a	r2, r2, ip
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		str1b	r0, r11, abort=21f
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		bsl	8b
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		and.a	ip, r1, #3
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		beq	1b
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10:		andn	r1, r1, #3
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		csub.a	ip, #2
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		ldr1w	r1, r11, abort=21f
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		beq	17f
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		bsg	18f
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		.macro	forward_copy_shift a b
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		sub.a	r2, r2, #28
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		bsl	14f
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11:		stm.w	(r5 - r9), [sp-]
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12:
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		ldr4w	r1, r4, r5, r6, r7, abort=19f
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		mov	r3, r11 pull #\a
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		sub.a	r2, r2, #32
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		ldr4w	r1, r8, r9, r10, r11, abort=19f
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		or	r3, r3, r4 push #\b
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		mov	r4, r4 pull #\a
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		or	r4, r4, r5 push #\b
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		mov	r5, r5 pull #\a
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		or	r5, r5, r6 push #\b
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		mov	r6, r6 pull #\a
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		or	r6, r6, r7 push #\b
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		mov	r7, r7 pull #\a
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		or	r7, r7, r8 push #\b
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		mov	r8, r8 pull #\a
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		or	r8, r8, r9 push #\b
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		mov	r9, r9 pull #\a
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		or	r9, r9, r10 push #\b
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		mov	r10, r10 pull #\a
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		or	r10, r10, r11 push #\b
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		str8w	r0, r3, r4, r5, r6, r7, r8, r9, r10, , abort=19f
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		beg	12b
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		ldm.w	(r5 - r9), [sp]+
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14:		and.a	ip, r2, #28
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		beq	16f
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15:		mov	r3, r11 pull #\a
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		ldr1w	r1, r11, abort=21f
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		sub.a	ip, ip, #4
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		or	r3, r3, r11 push #\b
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		str1w	r0, r3, abort=21f
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		bsg	15b
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16:		sub	r1, r1, #(\b / 8)
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		b	8b
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		.endm
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		forward_copy_shift	a=8	b=24
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17:		forward_copy_shift	a=16	b=16
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18:		forward_copy_shift	a=24	b=8
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/*
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 * Abort preamble and completion macros.
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 * If a fixup handler is required then those macros must surround it.
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 * It is assumed that the fixup code will handle the private part of
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 * the exit macro.
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 */
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	.macro	copy_abort_preamble
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19:	ldm.w	(r5 - r9), [sp]+
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	b	21f
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299:	.word	0			@ store lr
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					@ to avoid function call in fixup
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20:	ldm.w	(r5 - r8), [sp]+
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21:
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	adr	r1, 299b
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	stw	lr, [r1]
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	.endm
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	.macro	copy_abort_end
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	adr	lr, 299b
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	ldw	pc, [lr]
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	.endm
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