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linux/arch/loongarch/lib/memset.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

172 lines
2.5 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>
.macro fill_to_64 r0
bstrins.d \r0, \r0, 15, 8
bstrins.d \r0, \r0, 31, 16
bstrins.d \r0, \r0, 63, 32
.endm
.section .noinstr.text, "ax"
SYM_FUNC_START(memset)
/*
* Some CPUs support hardware unaligned access
*/
ALTERNATIVE "b __memset_generic", \
"b __memset_fast", CPU_FEATURE_UAL
SYM_FUNC_END(memset)
SYM_FUNC_ALIAS(__memset, memset)
EXPORT_SYMBOL(memset)
EXPORT_SYMBOL(__memset)
_ASM_NOKPROBE(memset)
_ASM_NOKPROBE(__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)
_ASM_NOKPROBE(__memset_generic)
/*
* void *__memset_fast(void *s, int c, size_t n)
*
* a0: s
* a1: c
* a2: n
*/
SYM_FUNC_START(__memset_fast)
/* fill a1 to 64 bits */
fill_to_64 a1
sltui t0, a2, 9
bnez t0, .Lsmall
add.d a2, a0, a2
st.d a1, a0, 0
/* align up address */
addi.d a3, a0, 8
bstrins.d a3, zero, 2, 0
addi.d a4, a2, -64
bgeu a3, a4, .Llt64
/* set 64 bytes at a time */
.Lloop64:
st.d a1, a3, 0
st.d a1, a3, 8
st.d a1, a3, 16
st.d a1, a3, 24
st.d a1, a3, 32
st.d a1, a3, 40
st.d a1, a3, 48
st.d a1, a3, 56
addi.d a3, a3, 64
bltu a3, a4, .Lloop64
/* set the remaining bytes */
.Llt64:
addi.d a4, a2, -32
bgeu a3, a4, .Llt32
st.d a1, a3, 0
st.d a1, a3, 8
st.d a1, a3, 16
st.d a1, a3, 24
addi.d a3, a3, 32
.Llt32:
addi.d a4, a2, -16
bgeu a3, a4, .Llt16
st.d a1, a3, 0
st.d a1, a3, 8
addi.d a3, a3, 16
.Llt16:
addi.d a4, a2, -8
bgeu a3, a4, .Llt8
st.d a1, a3, 0
.Llt8:
st.d a1, a2, -8
/* return */
jr ra
.align 4
.Lsmall:
pcaddi t0, 4
slli.d a2, a2, 4
add.d t0, t0, a2
jr t0
.align 4
0: jr ra
.align 4
1: st.b a1, a0, 0
jr ra
.align 4
2: st.h a1, a0, 0
jr ra
.align 4
3: st.h a1, a0, 0
st.b a1, a0, 2
jr ra
.align 4
4: st.w a1, a0, 0
jr ra
.align 4
5: st.w a1, a0, 0
st.b a1, a0, 4
jr ra
.align 4
6: st.w a1, a0, 0
st.h a1, a0, 4
jr ra
.align 4
7: st.w a1, a0, 0
st.w a1, a0, 3
jr ra
.align 4
8: st.d a1, a0, 0
jr ra
SYM_FUNC_END(__memset_fast)
_ASM_NOKPROBE(__memset_fast)
STACK_FRAME_NON_STANDARD __memset_fast