linux/arch/arm64/include/asm/insn-def.h

/* SPDX-License-Identifier: GPL-2.0-only */

#ifndef __ASM_INSN_DEF_H
#define __ASM_INSN_DEF_H

/* A64 instructions are always 32 bits. */
#define	AARCH64_INSN_SIZE		4

#endif /* __ASM_INSN_DEF_H */
arm64: insn: avoid circular include dependency Nathan reports that when building with CONFIG_LTO_CLANG_THIN=y, the build fails due to BUILD_BUG_ON() not being defined before its uss in <asm/insn.h>. The problem is that with LTO, we patch READ_ONCE(), and <asm/rwonce.h> includes <asm/insn.h>, creating a circular include chain: <linux/build_bug.h> <linux/compiler.h> <asm/rwonce.h> <asm/alternative-macros.h> <asm/insn.h> <linux/build-bug.h> ... and so when <asm/insn.h> includes <linux/build_bug.h>, none of the BUILD_BUG* definitions have happened yet. To avoid this, let's move AARCH64_INSN_SIZE into a header without any dependencies, such that it can always be safely included. At the same time, avoid including <asm/alternative.h> in <asm/insn.h>, which should no longer be necessary (and doesn't make sense when insn.h is consumed by userspace). Reported-by: Nathan Chancellor <nathan@kernel.org> Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Link: https://lore.kernel.org/r/20210621080830.GA37068@C02TD0UTHF1T.local Fixes: 3e00e39d9dad ("arm64: insn: move AARCH64_INSN_SIZE into <asm/insn.h>") Signed-off-by: Will Deacon <will@kernel.org> 2021-06-18 15:11:22 +00:00			`/* SPDX-License-Identifier: GPL-2.0-only */`

			`#ifndef __ASM_INSN_DEF_H`
			`#define __ASM_INSN_DEF_H`

			`/* A64 instructions are always 32 bits. */`
			`#define AARCH64_INSN_SIZE 4`

			`#endif /* __ASM_INSN_DEF_H */`