Introduce Kconfig option ARCH_STRICT_ALIGN to make -mstrict-align be configurable. Not all LoongArch cores support h/w unaligned access, we can use the -mstrict-align build parameter to prevent unaligned accesses. This option is disabled by default to optimise for performance, but you can enabled it manually if you want to run kernel on systems without h/w unaligned access support. Signed-off-by: Huacai Chen <chenhuacai@xxxxxxxxxxx> --- arch/loongarch/Kconfig | 10 ++++++++++ arch/loongarch/Makefile | 2 ++ 2 files changed, 12 insertions(+) diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 9cc8b84f7eb0..7470dcfb32f0 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -441,6 +441,16 @@ config ARCH_IOREMAP protection support. However, you can enable LoongArch DMW-based ioremap() for better performance. +config ARCH_STRICT_ALIGN + bool "Enable -mstrict-align to prevent unaligned accesses" + help + Not all LoongArch cores support h/w unaligned access, we can use + -mstrict-align build parameter to prevent unaligned accesses. + + This is disabled by default to optimise for performance, you can + enabled it manually if you want to run kernel on systems without + h/w unaligned access support. + config KEXEC bool "Kexec system call" select KEXEC_CORE diff --git a/arch/loongarch/Makefile b/arch/loongarch/Makefile index 4402387d2755..ccfb52700237 100644 --- a/arch/loongarch/Makefile +++ b/arch/loongarch/Makefile @@ -91,10 +91,12 @@ KBUILD_CPPFLAGS += -DVMLINUX_LOAD_ADDRESS=$(load-y) # instead of .eh_frame so we don't discard them. KBUILD_CFLAGS += -fno-asynchronous-unwind-tables +ifdef CONFIG_ARCH_STRICT_ALIGN # Don't emit unaligned accesses. # Not all LoongArch cores support unaligned access, and as kernel we can't # rely on others to provide emulation for these accesses. KBUILD_CFLAGS += $(call cc-option,-mstrict-align) +endif KBUILD_CFLAGS += -isystem $(shell $(CC) -print-file-name=include) -- 2.39.0
