linux/arch/loongarch/lib/clear_user.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

210 lines
3.6 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/asm-extable.h>
#include <asm/cpu.h>
#include <asm/regdef.h>
#include <asm/unwind_hints.h>
SYM_FUNC_START(__clear_user)
/*
* Some CPUs support hardware unaligned access
*/
ALTERNATIVE "b __clear_user_generic", \
"b __clear_user_fast", CPU_FEATURE_UAL
SYM_FUNC_END(__clear_user)
EXPORT_SYMBOL(__clear_user)
/*
* unsigned long __clear_user_generic(void *addr, size_t size)
*
* a0: addr
* a1: size
*/
SYM_FUNC_START(__clear_user_generic)
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
_asm_extable 1b, 2b
SYM_FUNC_END(__clear_user_generic)
/*
* unsigned long __clear_user_fast(void *addr, unsigned long size)
*
* a0: addr
* a1: size
*/
SYM_FUNC_START(__clear_user_fast)
sltui t0, a1, 9
bnez t0, .Lsmall
add.d a2, a0, a1
0: st.d zero, a0, 0
/* align up address */
addi.d a0, a0, 8
bstrins.d a0, zero, 2, 0
addi.d a3, a2, -64
bgeu a0, a3, .Llt64
/* set 64 bytes at a time */
.Lloop64:
1: st.d zero, a0, 0
2: st.d zero, a0, 8
3: st.d zero, a0, 16
4: st.d zero, a0, 24
5: st.d zero, a0, 32
6: st.d zero, a0, 40
7: st.d zero, a0, 48
8: st.d zero, a0, 56
addi.d a0, a0, 64
bltu a0, a3, .Lloop64
/* set the remaining bytes */
.Llt64:
addi.d a3, a2, -32
bgeu a0, a3, .Llt32
9: st.d zero, a0, 0
10: st.d zero, a0, 8
11: st.d zero, a0, 16
12: st.d zero, a0, 24
addi.d a0, a0, 32
.Llt32:
addi.d a3, a2, -16
bgeu a0, a3, .Llt16
13: st.d zero, a0, 0
14: st.d zero, a0, 8
addi.d a0, a0, 16
.Llt16:
addi.d a3, a2, -8
bgeu a0, a3, .Llt8
15: st.d zero, a0, 0
addi.d a0, a0, 8
.Llt8:
16: st.d zero, a2, -8
/* return */
move a0, zero
jr ra
.align 4
.Lsmall:
pcaddi t0, 4
slli.d a2, a1, 4
add.d t0, t0, a2
jr t0
.align 4
move a0, zero
jr ra
.align 4
17: st.b zero, a0, 0
move a0, zero
jr ra
.align 4
18: st.h zero, a0, 0
move a0, zero
jr ra
.align 4
19: st.h zero, a0, 0
20: st.b zero, a0, 2
move a0, zero
jr ra
.align 4
21: st.w zero, a0, 0
move a0, zero
jr ra
.align 4
22: st.w zero, a0, 0
23: st.b zero, a0, 4
move a0, zero
jr ra
.align 4
24: st.w zero, a0, 0
25: st.h zero, a0, 4
move a0, zero
jr ra
.align 4
26: st.w zero, a0, 0
27: st.w zero, a0, 3
move a0, zero
jr ra
.align 4
28: st.d zero, a0, 0
move a0, zero
jr ra
/* fixup and ex_table */
.Llarge_fixup:
sub.d a1, a2, a0
.Lsmall_fixup:
29: st.b zero, a0, 0
addi.d a0, a0, 1
addi.d a1, a1, -1
bgt a1, zero, 29b
.Lexit:
move a0, a1
jr ra
_asm_extable 0b, .Lsmall_fixup
_asm_extable 1b, .Llarge_fixup
_asm_extable 2b, .Llarge_fixup
_asm_extable 3b, .Llarge_fixup
_asm_extable 4b, .Llarge_fixup
_asm_extable 5b, .Llarge_fixup
_asm_extable 6b, .Llarge_fixup
_asm_extable 7b, .Llarge_fixup
_asm_extable 8b, .Llarge_fixup
_asm_extable 9b, .Llarge_fixup
_asm_extable 10b, .Llarge_fixup
_asm_extable 11b, .Llarge_fixup
_asm_extable 12b, .Llarge_fixup
_asm_extable 13b, .Llarge_fixup
_asm_extable 14b, .Llarge_fixup
_asm_extable 15b, .Llarge_fixup
_asm_extable 16b, .Llarge_fixup
_asm_extable 17b, .Lexit
_asm_extable 18b, .Lsmall_fixup
_asm_extable 19b, .Lsmall_fixup
_asm_extable 20b, .Lsmall_fixup
_asm_extable 21b, .Lsmall_fixup
_asm_extable 22b, .Lsmall_fixup
_asm_extable 23b, .Lsmall_fixup
_asm_extable 24b, .Lsmall_fixup
_asm_extable 25b, .Lsmall_fixup
_asm_extable 26b, .Lsmall_fixup
_asm_extable 27b, .Lsmall_fixup
_asm_extable 28b, .Lsmall_fixup
_asm_extable 29b, .Lexit
SYM_FUNC_END(__clear_user_fast)
STACK_FRAME_NON_STANDARD __clear_user_fast