acrn-kernel/arch/loongarch/lib/clear_user.S

44 lines
704 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, a1, \offset
jr ra
.previous
.endif
.section __ex_table, "a"
PTR \from\()b, \to\()b
.previous
.endm
/*
* unsigned long __clear_user(void *addr, size_t size)
*
* a0: addr
* a1: size
*/
SYM_FUNC_START(__clear_user)
beqz a1, 2f
1: st.b zero, a0, 0
addi.d a0, a0, 1
addi.d a1, a1, -1
bgtz a1, 1b
2: move a0, a1
jr ra
fixup_ex 1, 3, 0, 1
SYM_FUNC_END(__clear_user)
EXPORT_SYMBOL(__clear_user)