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 <sam@xxxxxxxxxxxx> Cc: Michal Marek <michal.lkml@xxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: x86@xxxxxxxxxx Cc: linux-kbuild@xxxxxxxxxxxxxxx Acked-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Signed-off-by: Nadav Amit <namit@xxxxxxxxxx> --- 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 f03a1e062503..af5dba613533 100644 --- a/Makefile +++ b/Makefile @@ -1071,7 +1071,7 @@ scripts: scripts_basic asm-generic gcc-plugins $(autoksyms_h) # 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: @@ -1094,7 +1094,9 @@ prepare2: prepare3 outputmakefile asm-generic prepare1: prepare2 $(version_h) $(autoksyms_h) include/generated/utsrelease.h $(cmd_crmodverdir) -archprepare: archheaders archscripts prepare1 scripts_basic +macroprepare: prepare1 archmacros + +archprepare: archheaders archscripts macroprepare scripts_basic prepare0: archprepare gcc-plugins $(Q)$(MAKE) $(build)=. @@ -1162,6 +1164,9 @@ 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 8f6e7eb8ae9f..944fa3bc9376 100644 --- a/arch/x86/Makefile +++ b/arch/x86/Makefile @@ -214,8 +214,8 @@ ifdef CONFIG_X86_64 KBUILD_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 # @@ -237,6 +237,13 @@ archscripts: scripts_basic archheaders: $(Q)$(MAKE) $(build)=arch/x86/entry/syscalls all +archmacros: + $(Q)$(MAKE) $(build)=arch/x86/kernel arch/x86/kernel/macros.s + +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 ce53639a864a..8aeb60eb6ee3 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
