215 строки
4.6 KiB
ArmAsm
215 строки
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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