WSL2-Linux-Kernel/arch/loongarch/lib/copy_user.S

48 строки
780 B
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/export.h>
#include <asm/regdef.h>
.macro fixup_ex from, to, offset, fix
.if \fix
.section .fixup, "ax"
\to: addi.d a0, a2, \offset
jr ra
.previous
.endif
.section __ex_table, "a"
PTR \from\()b, \to\()b
.previous
.endm
/*
* unsigned long __copy_user(void *to, const void *from, size_t n)
*
* a0: to
* a1: from
* a2: n
*/
SYM_FUNC_START(__copy_user)
beqz a2, 3f
1: ld.b t0, a1, 0
2: st.b t0, a0, 0
addi.d a0, a0, 1
addi.d a1, a1, 1
addi.d a2, a2, -1
bgt a2, zero, 1b
3: move a0, a2
jr ra
fixup_ex 1, 4, 0, 1
fixup_ex 2, 4, 0, 0
SYM_FUNC_END(__copy_user)
EXPORT_SYMBOL(__copy_user)