--- /dev/null
+From 52c9f93a9c482251cb0d224faa602ba26d462be8 Mon Sep 17 00:00:00 2001
+From: Nathan Chancellor <nathan@kernel.org>
+Date: Wed, 9 Mar 2022 12:16:34 -0700
+Subject: arm64: Do not include __READ_ONCE() block in assembly files
+
+From: Nathan Chancellor <nathan@kernel.org>
+
+commit 52c9f93a9c482251cb0d224faa602ba26d462be8 upstream.
+
+When building arm64 defconfig + CONFIG_LTO_CLANG_{FULL,THIN}=y after
+commit 558c303c9734 ("arm64: Mitigate spectre style branch history side
+channels"), the following error occurs:
+
+ <instantiation>:4:2: error: invalid fixup for movz/movk instruction
+ mov w0, #ARM_SMCCC_ARCH_WORKAROUND_3
+ ^
+
+Marc figured out that moving "#include <linux/init.h>" in
+include/linux/arm-smccc.h into a !__ASSEMBLY__ block resolves it. The
+full include chain with CONFIG_LTO=y from include/linux/arm-smccc.h:
+
+include/linux/init.h
+include/linux/compiler.h
+arch/arm64/include/asm/rwonce.h
+arch/arm64/include/asm/alternative-macros.h
+arch/arm64/include/asm/assembler.h
+
+The asm/alternative-macros.h include in asm/rwonce.h only happens when
+CONFIG_LTO is set, which ultimately casues asm/assembler.h to be
+included before the definition of ARM_SMCCC_ARCH_WORKAROUND_3. As a
+result, the preprocessor does not expand ARM_SMCCC_ARCH_WORKAROUND_3 in
+__mitigate_spectre_bhb_fw, which results in the error above.
+
+Avoid this problem by just avoiding the CONFIG_LTO=y __READ_ONCE() block
+in asm/rwonce.h with assembly files, as nothing in that block is useful
+to assembly files, which allows ARM_SMCCC_ARCH_WORKAROUND_3 to be
+properly expanded with CONFIG_LTO=y builds.
+
+Fixes: e35123d83ee3 ("arm64: lto: Strengthen READ_ONCE() to acquire when CONFIG_LTO=y")
+Cc: <stable@vger.kernel.org> # 5.11.x
+Link: https://lore.kernel.org/r/20220309155716.3988480-1-maz@kernel.org/
+Reported-by: Marc Zyngier <maz@kernel.org>
+Acked-by: James Morse <james.morse@arm.com>
+Signed-off-by: Nathan Chancellor <nathan@kernel.org>
+Link: https://lore.kernel.org/r/20220309191633.2307110-1-nathan@kernel.org
+Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ arch/arm64/include/asm/rwonce.h | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+--- a/arch/arm64/include/asm/rwonce.h
++++ b/arch/arm64/include/asm/rwonce.h
+@@ -5,7 +5,7 @@
+ #ifndef __ASM_RWONCE_H
+ #define __ASM_RWONCE_H
+
+-#ifdef CONFIG_LTO
++#if defined(CONFIG_LTO) && !defined(__ASSEMBLY__)
+
+ #include <linux/compiler_types.h>
+ #include <asm/alternative-macros.h>
+@@ -66,7 +66,7 @@
+ })
+
+ #endif /* !BUILD_VDSO */
+-#endif /* CONFIG_LTO */
++#endif /* CONFIG_LTO && !__ASSEMBLY__ */
+
+ #include <asm-generic/rwonce.h>
+