arch/s390/include/asm/jump_label.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_S390_JUMP_LABEL_H
#define _ASM_S390_JUMP_LABEL_H

#define HAVE_JUMP_LABEL_BATCH

#ifndef __ASSEMBLER__

#include <linux/types.h>
#include <linux/stringify.h>

#define JUMP_LABEL_NOP_SIZE 6

#ifdef CONFIG_CC_IS_CLANG
#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "i"
#elif __GNUC__ < 9
#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "X"
#else
#define JUMP_LABEL_STATIC_KEY_CONSTRAINT "jdd"
#endif

#define ARCH_JUMP_TABLE_ENTRY(key, label, local_label)	\
	".pushsection __jump_table,\"aw\"\n"		\
	".balign	8\n"				\
	".long	" local_label "-.," label "-.\n"	\
	".quad	" key "-.\n"				\
	".popsection\n"

/*
 * We use a brcl 0,<offset> instruction for jump labels so it
 * can be easily distinguished from a hotpatch generated instruction.
 */
#define ARCH_STATIC_BRANCH_ASM(key, label)	\
	"0:	brcl 0," label "\n"		\
	ARCH_JUMP_TABLE_ENTRY(key, label, "0b")

#define ARCH_STATIC_BRANCH_JUMP_ASM(key, label)	\
	"0:	brcl 15," label "\n"		\
	ARCH_JUMP_TABLE_ENTRY(key, label, "0b")

static __always_inline bool arch_static_branch(struct static_key *key, bool branch)
{
	asm goto(ARCH_STATIC_BRANCH_ASM("%0+%1", "%l[label]")
		: : JUMP_LABEL_STATIC_KEY_CONSTRAINT (key), "i" (branch) : : label);
	return false;
label:
	return true;
}

static __always_inline bool arch_static_branch_jump(struct static_key *key, bool branch)
{
	asm goto(ARCH_STATIC_BRANCH_JUMP_ASM("%0+%1", "%l[label]")
		: : JUMP_LABEL_STATIC_KEY_CONSTRAINT (key), "i" (branch) : : label);
	return false;
label:
	return true;
}

#endif  /* __ASSEMBLER__ */
#endif