74 строки
1.4 KiB
ArmAsm
74 строки
1.4 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Copyright (C) 2012 ARM Ltd.
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*/
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#include <linux/linkage.h>
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#include <asm/asm-uaccess.h>
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#include <asm/assembler.h>
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#include <asm/cache.h>
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/*
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* Copy to user space from a kernel buffer (alignment handled by the hardware)
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*
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* Parameters:
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* x0 - to
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* x1 - from
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* x2 - n
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* Returns:
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* x0 - bytes not copied
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*/
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.macro ldrb1 reg, ptr, val
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ldrb \reg, [\ptr], \val
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.endm
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.macro strb1 reg, ptr, val
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user_ldst 9998f, sttrb, \reg, \ptr, \val
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.endm
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.macro ldrh1 reg, ptr, val
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ldrh \reg, [\ptr], \val
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.endm
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.macro strh1 reg, ptr, val
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user_ldst 9997f, sttrh, \reg, \ptr, \val
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.endm
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.macro ldr1 reg, ptr, val
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ldr \reg, [\ptr], \val
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.endm
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.macro str1 reg, ptr, val
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user_ldst 9997f, sttr, \reg, \ptr, \val
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.endm
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.macro ldp1 reg1, reg2, ptr, val
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ldp \reg1, \reg2, [\ptr], \val
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.endm
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.macro stp1 reg1, reg2, ptr, val
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user_stp 9997f, \reg1, \reg2, \ptr, \val
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.endm
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end .req x5
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srcin .req x15
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SYM_FUNC_START(__arch_copy_to_user)
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add end, x0, x2
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mov srcin, x1
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#include "copy_template.S"
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mov x0, #0
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ret
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// Exception fixups
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9997: cmp dst, dstin
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b.ne 9998f
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// Before being absolutely sure we couldn't copy anything, try harder
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ldrb tmp1w, [srcin]
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USER(9998f, sttrb tmp1w, [dst])
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add dst, dst, #1
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9998: sub x0, end, dst // bytes not copied
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ret
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SYM_FUNC_END(__arch_copy_to_user)
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EXPORT_SYMBOL(__arch_copy_to_user)
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