OpenCloudOS-Kernel/arch/loongarch/lib/memset.S

92 lines
1.4 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <asm/alternative-asm.h>
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/cpu.h>
#include <asm/export.h>
#include <asm/regdef.h>
.macro fill_to_64 r0
bstrins.d \r0, \r0, 15, 8
bstrins.d \r0, \r0, 31, 16
bstrins.d \r0, \r0, 63, 32
.endm
SYM_FUNC_START(memset)
/*
* Some CPUs support hardware unaligned access
*/
ALTERNATIVE "b __memset_generic", \
"b __memset_fast", CPU_FEATURE_UAL
SYM_FUNC_END(memset)
EXPORT_SYMBOL(memset)
/*
* void *__memset_generic(void *s, int c, size_t n)
*
* a0: s
* a1: c
* a2: n
*/
SYM_FUNC_START(__memset_generic)
move a3, a0
beqz a2, 2f
1: st.b a1, a0, 0
addi.d a0, a0, 1
addi.d a2, a2, -1
bgt a2, zero, 1b
2: move a0, a3
jr ra
SYM_FUNC_END(__memset_generic)
/*
* void *__memset_fast(void *s, int c, size_t n)
*
* a0: s
* a1: c
* a2: n
*/
SYM_FUNC_START(__memset_fast)
move a3, a0
beqz a2, 3f
ori a4, zero, 64
blt a2, a4, 2f
/* fill a1 to 64 bits */
fill_to_64 a1
/* set 64 bytes at a time */
1: st.d a1, a0, 0
st.d a1, a0, 8
st.d a1, a0, 16
st.d a1, a0, 24
st.d a1, a0, 32
st.d a1, a0, 40
st.d a1, a0, 48
st.d a1, a0, 56
addi.d a0, a0, 64
addi.d a2, a2, -64
bge a2, a4, 1b
beqz a2, 3f
/* set the remaining bytes */
2: st.b a1, a0, 0
addi.d a0, a0, 1
addi.d a2, a2, -1
bgt a2, zero, 2b
/* return */
3: move a0, a3
jr ra
SYM_FUNC_END(__memset_fast)