linux-zen-server/arch/loongarch/lib/memmove.S

126 lines
2.2 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>
SYM_FUNC_START(memmove)
blt a0, a1, 1f /* dst < src, memcpy */
blt a1, a0, 3f /* src < dst, rmemcpy */
jr ra /* dst == src, return */
/* if (src - dst) < 64, copy 1 byte at a time */
1: ori a3, zero, 64
sub.d t0, a1, a0
blt t0, a3, 2f
b memcpy
2: b __memcpy_generic
/* if (dst - src) < 64, copy 1 byte at a time */
3: ori a3, zero, 64
sub.d t0, a0, a1
blt t0, a3, 4f
b rmemcpy
4: b __rmemcpy_generic
SYM_FUNC_END(memmove)
_ASM_NOKPROBE(memmove)
EXPORT_SYMBOL(memmove)
SYM_FUNC_START(rmemcpy)
/*
* Some CPUs support hardware unaligned access
*/
ALTERNATIVE "b __rmemcpy_generic", \
"b __rmemcpy_fast", CPU_FEATURE_UAL
SYM_FUNC_END(rmemcpy)
_ASM_NOKPROBE(rmemcpy)
/*
* void *__rmemcpy_generic(void *dst, const void *src, size_t n)
*
* a0: dst
* a1: src
* a2: n
*/
SYM_FUNC_START(__rmemcpy_generic)
move a3, a0
beqz a2, 2f
add.d a0, a0, a2
add.d a1, a1, a2
1: ld.b t0, a1, -1
st.b t0, a0, -1
addi.d a0, a0, -1
addi.d a1, a1, -1
addi.d a2, a2, -1
bgt a2, zero, 1b
2: move a0, a3
jr ra
SYM_FUNC_END(__rmemcpy_generic)
_ASM_NOKPROBE(__rmemcpy_generic)
/*
* void *__rmemcpy_fast(void *dst, const void *src, size_t n)
*
* a0: dst
* a1: src
* a2: n
*/
SYM_FUNC_START(__rmemcpy_fast)
move a3, a0
beqz a2, 3f
add.d a0, a0, a2
add.d a1, a1, a2
ori a4, zero, 64
blt a2, a4, 2f
/* copy 64 bytes at a time */
1: ld.d t0, a1, -8
ld.d t1, a1, -16
ld.d t2, a1, -24
ld.d t3, a1, -32
ld.d t4, a1, -40
ld.d t5, a1, -48
ld.d t6, a1, -56
ld.d t7, a1, -64
st.d t0, a0, -8
st.d t1, a0, -16
st.d t2, a0, -24
st.d t3, a0, -32
st.d t4, a0, -40
st.d t5, a0, -48
st.d t6, a0, -56
st.d t7, a0, -64
addi.d a0, a0, -64
addi.d a1, a1, -64
addi.d a2, a2, -64
bge a2, a4, 1b
beqz a2, 3f
/* copy the remaining bytes */
2: ld.b t0, a1, -1
st.b t0, a0, -1
addi.d a0, a0, -1
addi.d a1, a1, -1
addi.d a2, a2, -1
bgt a2, zero, 2b
/* return */
3: move a0, a3
jr ra
SYM_FUNC_END(__rmemcpy_fast)
_ASM_NOKPROBE(__rmemcpy_fast)