linux/arch/loongarch/lib/memcpy.S
Tiezhu Yang cb8a2ef084 LoongArch: Add ORC stack unwinder support
The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is
similar in concept to a DWARF unwinder. The difference is that the format
of the ORC data is much simpler than DWARF, which in turn allows the ORC
unwinder to be much simpler and faster.

The ORC data consists of unwind tables which are generated by objtool.
After analyzing all the code paths of a .o file, it determines information
about the stack state at each instruction address in the file and outputs
that information to the .orc_unwind and .orc_unwind_ip sections.

The per-object ORC sections are combined at link time and are sorted and
post-processed at boot time. The unwinder uses the resulting data to
correlate instruction addresses with their stack states at run time.

Most of the logic are similar with x86, in order to get ra info before ra
is saved into stack, add ra_reg and ra_offset into orc_entry. At the same
time, modify some arch-specific code to silence the objtool warnings.

Co-developed-by: Jinyang He <hejinyang@loongson.cn>
Signed-off-by: Jinyang He <hejinyang@loongson.cn>
Co-developed-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2024-03-11 22:23:47 +08:00

203 lines
3.1 KiB
ArmAsm

/* SPDX-License-Identifier: GPL-2.0 */
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*/
#include <linux/export.h>
#include <asm/alternative-asm.h>
#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/cpu.h>
#include <asm/regdef.h>
#include <asm/unwind_hints.h>
.section .noinstr.text, "ax"
SYM_FUNC_START(memcpy)
/*
* Some CPUs support hardware unaligned access
*/
ALTERNATIVE "b __memcpy_generic", \
"b __memcpy_fast", CPU_FEATURE_UAL
SYM_FUNC_END(memcpy)
SYM_FUNC_ALIAS(__memcpy, memcpy)
EXPORT_SYMBOL(memcpy)
EXPORT_SYMBOL(__memcpy)
_ASM_NOKPROBE(memcpy)
_ASM_NOKPROBE(__memcpy)
/*
* void *__memcpy_generic(void *dst, const void *src, size_t n)
*
* a0: dst
* a1: src
* a2: n
*/
SYM_FUNC_START(__memcpy_generic)
move a3, a0
beqz a2, 2f
1: ld.b t0, a1, 0
st.b t0, a0, 0
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(__memcpy_generic)
_ASM_NOKPROBE(__memcpy_generic)
.align 5
SYM_FUNC_START_NOALIGN(__memcpy_small)
pcaddi t0, 8
slli.d a2, a2, 5
add.d t0, t0, a2
jr t0
.align 5
0: jr ra
.align 5
1: ld.b t0, a1, 0
st.b t0, a0, 0
jr ra
.align 5
2: ld.h t0, a1, 0
st.h t0, a0, 0
jr ra
.align 5
3: ld.h t0, a1, 0
ld.b t1, a1, 2
st.h t0, a0, 0
st.b t1, a0, 2
jr ra
.align 5
4: ld.w t0, a1, 0
st.w t0, a0, 0
jr ra
.align 5
5: ld.w t0, a1, 0
ld.b t1, a1, 4
st.w t0, a0, 0
st.b t1, a0, 4
jr ra
.align 5
6: ld.w t0, a1, 0
ld.h t1, a1, 4
st.w t0, a0, 0
st.h t1, a0, 4
jr ra
.align 5
7: ld.w t0, a1, 0
ld.w t1, a1, 3
st.w t0, a0, 0
st.w t1, a0, 3
jr ra
.align 5
8: ld.d t0, a1, 0
st.d t0, a0, 0
jr ra
SYM_FUNC_END(__memcpy_small)
_ASM_NOKPROBE(__memcpy_small)
/*
* void *__memcpy_fast(void *dst, const void *src, size_t n)
*
* a0: dst
* a1: src
* a2: n
*/
SYM_FUNC_START(__memcpy_fast)
sltui t0, a2, 9
bnez t0, __memcpy_small
add.d a3, a1, a2
add.d a2, a0, a2
ld.d a6, a1, 0
ld.d a7, a3, -8
/* align up destination address */
andi t1, a0, 7
sub.d t0, zero, t1
addi.d t0, t0, 8
add.d a1, a1, t0
add.d a5, a0, t0
addi.d a4, a3, -64
bgeu a1, a4, .Llt64
/* copy 64 bytes at a time */
.Lloop64:
ld.d t0, a1, 0
ld.d t1, a1, 8
ld.d t2, a1, 16
ld.d t3, a1, 24
ld.d t4, a1, 32
ld.d t5, a1, 40
ld.d t6, a1, 48
ld.d t7, a1, 56
addi.d a1, a1, 64
st.d t0, a5, 0
st.d t1, a5, 8
st.d t2, a5, 16
st.d t3, a5, 24
st.d t4, a5, 32
st.d t5, a5, 40
st.d t6, a5, 48
st.d t7, a5, 56
addi.d a5, a5, 64
bltu a1, a4, .Lloop64
/* copy the remaining bytes */
.Llt64:
addi.d a4, a3, -32
bgeu a1, a4, .Llt32
ld.d t0, a1, 0
ld.d t1, a1, 8
ld.d t2, a1, 16
ld.d t3, a1, 24
addi.d a1, a1, 32
st.d t0, a5, 0
st.d t1, a5, 8
st.d t2, a5, 16
st.d t3, a5, 24
addi.d a5, a5, 32
.Llt32:
addi.d a4, a3, -16
bgeu a1, a4, .Llt16
ld.d t0, a1, 0
ld.d t1, a1, 8
addi.d a1, a1, 16
st.d t0, a5, 0
st.d t1, a5, 8
addi.d a5, a5, 16
.Llt16:
addi.d a4, a3, -8
bgeu a1, a4, .Llt8
ld.d t0, a1, 0
st.d t0, a5, 0
.Llt8:
st.d a6, a0, 0
st.d a7, a2, -8
/* return */
jr ra
SYM_FUNC_END(__memcpy_fast)
_ASM_NOKPROBE(__memcpy_fast)
STACK_FRAME_NON_STANDARD __memcpy_small