arch/arm64/include/asm/jump_label.h

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (C) 2013 Huawei Ltd.
 * Author: Jiang Liu <liuj97@gmail.com>
 *
 * Based on arch/arm/include/asm/jump_label.h
 */
#ifndef __ASM_JUMP_LABEL_H
#define __ASM_JUMP_LABEL_H

#ifndef __ASSEMBLY__

#include <linux/types.h>
#include <asm/insn.h>

#define JUMP_LABEL_NOP_SIZE		AARCH64_INSN_SIZE

/*
 * Prefer the constraint "S" to support PIC with GCC. Clang before 19 does not
 * support "S" on a symbol with a constant offset, so we use "i" as a fallback.
 */
static __always_inline bool arch_static_branch(struct static_key * const key,
					       const bool branch)
{
	asm goto(
		"1:	nop					\n\t"
		 "	.pushsection	__jump_table, \"aw\"	\n\t"
		 "	.align		3			\n\t"
		 "	.long		1b - ., %l[l_yes] - .	\n\t"
		 "	.quad		(%[key] - .) + %[bit0]  \n\t"
		 "	.popsection				\n\t"
		 :  :  [key]"Si"(key), [bit0]"i"(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 goto(
		"1:	b		%l[l_yes]		\n\t"
		 "	.pushsection	__jump_table, \"aw\"	\n\t"
		 "	.align		3			\n\t"
		 "	.long		1b - ., %l[l_yes] - .	\n\t"
		 "	.quad		(%[key] - .) + %[bit0]  \n\t"
		 "	.popsection				\n\t"
		 :  :  [key]"Si"(key), [bit0]"i"(branch) :  : l_yes);

	return false;
l_yes:
	return true;
}

#endif  /* __ASSEMBLY__ */
#endif	/* __ASM_JUMP_LABEL_H */