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LoongArch: Add jump-label implementation

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Add support for jump labels based on the ARM64 version.

Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
This commit is contained in:
Youling Tang 2023-06-29 20:58:44 +08:00 committed by Huacai Chen
parent 5d55377040
commit f02644e32c
5 changed files with 77 additions and 1 deletions
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2
Documentation/features/core/jump-labels/arch-support.txt
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@ -13,7 +13,7 @@
| csky: | ok |
| hexagon: | TODO |
| ia64: | TODO |
| loongarch: | TODO |
| loongarch: | ok |
| m68k: | TODO |
| microblaze: | TODO |
| mips: | ok |

2
arch/loongarch/Kconfig
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@ -87,6 +87,8 @@ config LOONGARCH
select GPIOLIB
select HAS_IOPORT
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_JUMP_LABEL_RELATIVE
select HAVE_ARCH_MMAP_RND_BITS if MMU
select HAVE_ARCH_SECCOMP_FILTER
select HAVE_ARCH_TRACEHOOK

50
arch/loongarch/include/asm/jump_label.h Normal file
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@ -0,0 +1,50 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2023 Loongson Technology Corporation Limited
*
* Based on arch/arm64/include/asm/jump_label.h
*/
#ifndef __ASM_JUMP_LABEL_H
#define __ASM_JUMP_LABEL_H
#ifndef __ASSEMBLY__
#include <linux/types.h>
#define JUMP_LABEL_NOP_SIZE 4
#define JUMP_TABLE_ENTRY \
".pushsection __jump_table, \"aw\" \n\t" \
".align 3 \n\t" \
".long 1b - ., %l[l_yes] - . \n\t" \
".quad %0 - . \n\t" \
".popsection \n\t"
static __always_inline bool arch_static_branch(struct static_key * const key, const bool branch)
{
asm_volatile_goto(
"1: nop \n\t"
JUMP_TABLE_ENTRY
: : "i"(&((char *)key)[branch]) : : l_yes);
return false;
l_yes:
return true;
}
static __always_inline bool arch_static_branch_jump(struct static_key * const key, const bool branch)
{
asm_volatile_goto(
"1: b %l[l_yes] \n\t"
JUMP_TABLE_ENTRY
: : "i"(&((char *)key)[branch]) : : l_yes);
return false;
l_yes:
return true;
}
#endif /* __ASSEMBLY__ */
#endif /* __ASM_JUMP_LABEL_H */

2
arch/loongarch/kernel/Makefile
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@ -54,4 +54,6 @@ obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
obj-$(CONFIG_KPROBES) += kprobes.o kprobes_trampoline.o
obj-$(CONFIG_JUMP_LABEL) += jump_label.o
CPPFLAGS_vmlinux.lds := $(KBUILD_CFLAGS)

22
arch/loongarch/kernel/jump_label.c Normal file
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@ -0,0 +1,22 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2023 Loongson Technology Corporation Limited
*
* Based on arch/arm64/kernel/jump_label.c
*/
#include <linux/kernel.h>
#include <linux/jump_label.h>
#include <asm/inst.h>
void arch_jump_label_transform(struct jump_entry *entry, enum jump_label_type type)
{
u32 insn;
void *addr = (void *)jump_entry_code(entry);
if (type == JUMP_LABEL_JMP)
insn = larch_insn_gen_b(jump_entry_code(entry), jump_entry_target(entry));
else
insn = larch_insn_gen_nop();
larch_insn_patch_text(addr, insn);
}