Commit f02644e3 authored by Youling Tang's avatar Youling Tang Committed by Huacai Chen
Browse files

LoongArch: Add jump-label implementation 



Add support for jump labels based on the ARM64 version.

Acked-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: default avatarYouling Tang <tangyouling@loongson.cn>
Signed-off-by: default avatarHuacai Chen <chenhuacai@loongson.cn>
parent 5d553770

Documentation/features/core/jump-labels/arch-support.txt

+1 −1
Original line number Original line Diff line number Diff line
@@ -13,7 +13,7 @@ 
    |        csky: |  ok  |

    |        csky: |  ok  |

    |     hexagon: | TODO |

    |     hexagon: | TODO |

    |        ia64: | TODO |

    |        ia64: | TODO |

    |   loongarch: | TODO |

    |   loongarch: |  ok  |

    |        m68k: | TODO |

    |        m68k: | TODO |

    |  microblaze: | TODO |

    |  microblaze: | TODO |

    |        mips: |  ok  |

    |        mips: |  ok  |

arch/loongarch/Kconfig

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@@ -87,6 +87,8 @@ config LOONGARCH 
	select GPIOLIB

	select GPIOLIB

	select HAS_IOPORT

	select HAS_IOPORT

	select HAVE_ARCH_AUDITSYSCALL

	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_MMAP_RND_BITS if MMU

	select HAVE_ARCH_SECCOMP_FILTER

	select HAVE_ARCH_SECCOMP_FILTER

	select HAVE_ARCH_TRACEHOOK

	select HAVE_ARCH_TRACEHOOK

arch/loongarch/include/asm/jump_label.h

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/* 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 */

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_KPROBES)		+= kprobes.o kprobes_trampoline.o





obj-$(CONFIG_JUMP_LABEL)	+= jump_label.o



CPPFLAGS_vmlinux.lds		:= $(KBUILD_CFLAGS)
 
CPPFLAGS_vmlinux.lds		:= $(KBUILD_CFLAGS)

arch/loongarch/kernel/jump_label.c

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// 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);

}