linux/arch/loongarch/lib/copy_user.S
WANG Xuerui 1fdb9a9249 LoongArch: Simplify "BGT foo, zero" with BGTZ
Support for the syntactic sugar is present in upstream binutils port
from the beginning. Use it for shorter lines and better consistency.
Generated code should be identical.

Signed-off-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2022-07-29 18:22:32 +08:00

48 lines
775 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
bgtz a2, 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)