Using macros for inline assembly improves both readability and compilation decisions that are distorted by big assembly blocks that use alternative sections. Compile macros.S and use it to assemble all C files. Currently, only x86 will use it.
Cc: Sam Ravnborg <s...@ravnborg.org> Cc: Masahiro Yamada <yamada.masah...@socionext.com> Cc: Michal Marek <michal.l...@markovi.net> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Ingo Molnar <mi...@redhat.com> Cc: "H. Peter Anvin" <h...@zytor.com> Cc: x...@kernel.org Cc: linux-kbu...@vger.kernel.org Acked-by: Peter Zijlstra (Intel) <pet...@infradead.org> Signed-off-by: Nadav Amit <na...@vmware.com> --- Makefile | 9 +++++++-- arch/x86/Makefile | 11 +++++++++-- arch/x86/kernel/macros.S | 7 +++++++ scripts/Kbuild.include | 4 +++- scripts/mod/Makefile | 2 ++ 5 files changed, 28 insertions(+), 5 deletions(-) create mode 100644 arch/x86/kernel/macros.S diff --git a/Makefile b/Makefile index ca2af1ab91eb..66c1da72c156 100644 --- a/Makefile +++ b/Makefile @@ -1056,7 +1056,7 @@ scripts: scripts_basic include/config/auto.conf include/config/tristate.conf \ # version.h and scripts_basic is processed / created. # Listed in dependency order -PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3 +PHONY += prepare archprepare macroprepare prepare0 prepare1 prepare2 prepare3 # prepare3 is used to check if we are building in a separate output directory, # and if so do: @@ -1080,7 +1080,9 @@ prepare1: prepare2 $(version_h) $(autoksyms_h) include/generated/utsrelease.h \ include/config/auto.conf $(cmd_crmodverdir) -archprepare: archheaders archscripts prepare1 scripts_basic +macroprepare: prepare1 archmacros + +archprepare: archheaders archscripts macroprepare scripts_basic prepare0: archprepare gcc-plugins $(Q)$(MAKE) $(build)=. @@ -1148,6 +1150,9 @@ archheaders: PHONY += archscripts archscripts: +PHONY += archmacros +archmacros: + PHONY += __headers __headers: $(version_h) scripts_basic uapi-asm-generic archheaders archscripts $(Q)$(MAKE) $(build)=scripts build_unifdef diff --git a/arch/x86/Makefile b/arch/x86/Makefile index f0a6ea22429d..363c3d8ed964 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -235,8 +235,8 @@ ifdef CONFIG_X86_64 LDFLAGS += $(call ld-option, -z max-page-size=0x200000) endif -# Speed up the build -KBUILD_CFLAGS += -pipe +# We cannot use -pipe flag since we give an additional .s file to the compiler +#KBUILD_CFLAGS += -pipe # Workaround for a gcc prelease that unfortunately was shipped in a suse release KBUILD_CFLAGS += -Wno-sign-compare # @@ -258,11 +258,18 @@ archscripts: scripts_basic archheaders: $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all +archmacros: + $(Q)$(MAKE) $(build)=arch/x86/kernel arch/x86/kernel/macros.s + archprepare: ifeq ($(CONFIG_KEXEC_FILE),y) $(Q)$(MAKE) $(build)=arch/x86/purgatory arch/x86/purgatory/kexec-purgatory.c endif +ASM_MACRO_FLAGS = -Wa,arch/x86/kernel/macros.s +export ASM_MACRO_FLAGS +KBUILD_CFLAGS += $(ASM_MACRO_FLAGS) + ### # Kernel objects diff --git a/arch/x86/kernel/macros.S b/arch/x86/kernel/macros.S new file mode 100644 index 000000000000..cfc1c7d1a6eb --- /dev/null +++ b/arch/x86/kernel/macros.S @@ -0,0 +1,7 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +/* + * This file includes headers whose assembly part includes macros which are + * commonly used. The macros are precompiled into assmebly file which is later + * assembled together with each compiled file. + */ diff --git a/scripts/Kbuild.include b/scripts/Kbuild.include index c8156d61678c..8eeb5636a2a7 100644 --- a/scripts/Kbuild.include +++ b/scripts/Kbuild.include @@ -115,7 +115,9 @@ __cc-option = $(call try-run,\ # Do not attempt to build with gcc plugins during cc-option tests. # (And this uses delayed resolution so the flags will be up to date.) -CC_OPTION_CFLAGS = $(filter-out $(GCC_PLUGINS_CFLAGS),$(KBUILD_CFLAGS)) +# In addition, do not include the asm macros which are built later. +CC_OPTION_FILTERED = $(GCC_PLUGINS_CFLAGS) $(ASM_MACRO_FLAGS) +CC_OPTION_CFLAGS = $(filter-out $(CC_OPTION_FILTERED),$(KBUILD_CFLAGS)) # cc-option # Usage: cflags-y += $(call cc-option,-march=winchip-c6,-march=i586) diff --git a/scripts/mod/Makefile b/scripts/mod/Makefile index 42c5d50f2bcc..a5b4af47987a 100644 --- a/scripts/mod/Makefile +++ b/scripts/mod/Makefile @@ -4,6 +4,8 @@ OBJECT_FILES_NON_STANDARD := y hostprogs-y := modpost mk_elfconfig always := $(hostprogs-y) empty.o +CFLAGS_REMOVE_empty.o := $(ASM_MACRO_FLAGS) + modpost-objs := modpost.o file2alias.o sumversion.o devicetable-offsets-file := devicetable-offsets.h -- 2.17.1