Commit d8ecc5cd authored by Sam Ravnborg's avatar Sam Ravnborg Committed by Michal Marek

kbuild: asm-generic support

There is an increasing amount of header files
shared between individual architectures in asm-generic.
To avoid a lot of dummy wrapper files that just
include the corresponding file in asm-generic provide
some basic support in kbuild for this.

With the following patch an architecture can maintain
a list of files in the file arch/$(ARCH)/include/asm/Kbuild

To use a generic file just add:

        generic-y += <name-of-header-file.h>

For each file listed kbuild will generate the necessary
wrapper in arch/$(ARCH)/include/generated/asm.

When installing userspace headers a wrapper is likewise created.

The original inspiration for this came from the unicore32
patchset - although a different method is used.

The patch includes several improvements from Arnd Bergmann.
Michael Marek contributed Makefile.asm-generic.

Remis Baima did an intial implementation along to achive
the same - see https://patchwork.kernel.org/patch/13352/Signed-off-by: default avatarSam Ravnborg <sam@ravnborg.org>
Acked-by: default avatarGuan Xuetao <guanxuetao@mprc.pku.edu.cn>
Tested-by: default avatarGuan Xuetao <guanxuetao@mprc.pku.edu.cn>
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Cc: Remis Lima Baima <remis.developer@googlemail.com>
Signed-off-by: default avatarMichal Marek <mmarek@suse.cz>
parent 28bc20dc
...@@ -57,6 +57,7 @@ modules.builtin ...@@ -57,6 +57,7 @@ modules.builtin
include/config include/config
include/linux/version.h include/linux/version.h
include/generated include/generated
arch/*/include/generated
# stgit generated dirs # stgit generated dirs
patches-* patches-*
......
...@@ -40,11 +40,13 @@ This document describes the Linux kernel Makefiles. ...@@ -40,11 +40,13 @@ This document describes the Linux kernel Makefiles.
--- 6.6 Commands useful for building a boot image --- 6.6 Commands useful for building a boot image
--- 6.7 Custom kbuild commands --- 6.7 Custom kbuild commands
--- 6.8 Preprocessing linker scripts --- 6.8 Preprocessing linker scripts
--- 6.9 Generic header files
=== 7 Kbuild syntax for exported headers === 7 Kbuild syntax for exported headers
--- 7.1 header-y --- 7.1 header-y
--- 7.2 objhdr-y --- 7.2 objhdr-y
--- 7.3 destination-y --- 7.3 destination-y
--- 7.4 generic-y
=== 8 Kbuild Variables === 8 Kbuild Variables
=== 9 Makefile language === 9 Makefile language
...@@ -1214,6 +1216,14 @@ When kbuild executes, the following steps are followed (roughly): ...@@ -1214,6 +1216,14 @@ When kbuild executes, the following steps are followed (roughly):
The kbuild infrastructure for *lds file are used in several The kbuild infrastructure for *lds file are used in several
architecture-specific files. architecture-specific files.
--- 6.9 Generic header files
The directory include/asm-generic contains the header files
that may be shared between individual architectures.
The recommended approach how to use a generic header file is
to list the file in the Kbuild file.
See "7.4 generic-y" for further info on syntax etc.
=== 7 Kbuild syntax for exported headers === 7 Kbuild syntax for exported headers
The kernel include a set of headers that is exported to userspace. The kernel include a set of headers that is exported to userspace.
...@@ -1270,6 +1280,32 @@ See subsequent chapter for the syntax of the Kbuild file. ...@@ -1270,6 +1280,32 @@ See subsequent chapter for the syntax of the Kbuild file.
In the example above all exported headers in the Kbuild file In the example above all exported headers in the Kbuild file
will be located in the directory "include/linux" when exported. will be located in the directory "include/linux" when exported.
--- 7.4 generic-y
If an architecture uses a verbatim copy of a header from
include/asm-generic then this is listed in the file
arch/$(ARCH)/include/asm/Kbuild like this:
Example:
#arch/x86/include/asm/Kbuild
generic-y += termios.h
generic-y += rtc.h
During the prepare phase of the build a wrapper include
file is generated in the directory:
arch/$(ARCH)/include/generated/asm
When a header is exported where the architecture uses
the generic header a similar wrapper is generated as part
of the set of exported headers in the directory:
usr/include/asm
The generated wrapper will in both cases look like the following:
Example: termios.h
#include <asm-generic/termios.h>
=== 8 Kbuild Variables === 8 Kbuild Variables
......
...@@ -349,7 +349,8 @@ CFLAGS_GCOV = -fprofile-arcs -ftest-coverage ...@@ -349,7 +349,8 @@ CFLAGS_GCOV = -fprofile-arcs -ftest-coverage
# Use LINUXINCLUDE when you must reference the include/ directory. # Use LINUXINCLUDE when you must reference the include/ directory.
# Needed to be compatible with the O= option # Needed to be compatible with the O= option
LINUXINCLUDE := -I$(srctree)/arch/$(hdr-arch)/include -Iinclude \ LINUXINCLUDE := -I$(srctree)/arch/$(hdr-arch)/include \
-Iarch/$(hdr-arch)/include/generated -Iinclude \
$(if $(KBUILD_SRC), -I$(srctree)/include) \ $(if $(KBUILD_SRC), -I$(srctree)/include) \
-include include/generated/autoconf.h -include include/generated/autoconf.h
...@@ -417,6 +418,12 @@ ifneq ($(KBUILD_SRC),) ...@@ -417,6 +418,12 @@ ifneq ($(KBUILD_SRC),)
$(srctree) $(objtree) $(VERSION) $(PATCHLEVEL) $(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
endif endif
# Support for using generic headers in asm-generic
PHONY += asm-generic
asm-generic:
$(Q)$(MAKE) -f $(srctree)/scripts/Makefile.asm-generic \
obj=arch/$(SRCARCH)/include/generated/asm
# To make sure we do not include .config for any of the *config targets # To make sure we do not include .config for any of the *config targets
# catch them early, and hand them over to scripts/kconfig/Makefile # catch them early, and hand them over to scripts/kconfig/Makefile
# It is allowed to specify more targets when calling make, including # It is allowed to specify more targets when calling make, including
...@@ -954,7 +961,7 @@ ifneq ($(KBUILD_SRC),) ...@@ -954,7 +961,7 @@ ifneq ($(KBUILD_SRC),)
endif endif
# prepare2 creates a makefile if using a separate output directory # prepare2 creates a makefile if using a separate output directory
prepare2: prepare3 outputmakefile prepare2: prepare3 outputmakefile asm-generic
prepare1: prepare2 include/linux/version.h include/generated/utsrelease.h \ prepare1: prepare2 include/linux/version.h include/generated/utsrelease.h \
include/config/auto.conf include/config/auto.conf
...@@ -1028,7 +1035,7 @@ hdr-inst := -rR -f $(srctree)/scripts/Makefile.headersinst obj ...@@ -1028,7 +1035,7 @@ hdr-inst := -rR -f $(srctree)/scripts/Makefile.headersinst obj
hdr-dst = $(if $(KBUILD_HEADERS), dst=include/asm-$(hdr-arch), dst=include/asm) hdr-dst = $(if $(KBUILD_HEADERS), dst=include/asm-$(hdr-arch), dst=include/asm)
PHONY += __headers PHONY += __headers
__headers: include/linux/version.h scripts_basic FORCE __headers: include/linux/version.h scripts_basic asm-generic FORCE
$(Q)$(MAKE) $(build)=scripts build_unifdef $(Q)$(MAKE) $(build)=scripts build_unifdef
PHONY += headers_install_all PHONY += headers_install_all
...@@ -1143,7 +1150,8 @@ CLEAN_FILES += vmlinux System.map \ ...@@ -1143,7 +1150,8 @@ CLEAN_FILES += vmlinux System.map \
.tmp_kallsyms* .tmp_version .tmp_vmlinux* .tmp_System.map .tmp_kallsyms* .tmp_version .tmp_vmlinux* .tmp_System.map
# Directories & files removed with 'make mrproper' # Directories & files removed with 'make mrproper'
MRPROPER_DIRS += include/config usr/include include/generated MRPROPER_DIRS += include/config usr/include include/generated \
arch/*/include/generated
MRPROPER_FILES += .config .config.old .version .old_version \ MRPROPER_FILES += .config .config.old .version .old_version \
include/linux/version.h \ include/linux/version.h \
Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS Module.symvers tags TAGS cscope* GPATH GTAGS GRTAGS GSYMS
......
# include/asm-generic contains a lot of files that are used
# verbatim by several architectures.
#
# This Makefile reads the file arch/$(SRCARCH)/include/asm/Kbuild
# and for each file listed in this file with generic-y creates
# a small wrapper file in $(obj) (arch/$(SRCARCH)/include/generated/asm)
kbuild-file := $(srctree)/arch/$(SRCARCH)/include/asm/Kbuild
include $(kbuild-file)
include scripts/Kbuild.include
# Create output directory if not already present
_dummy := $(shell [ -d $(obj) ] || mkdir -p $(obj))
quiet_cmd_wrap = WRAP $@
cmd_wrap = echo "\#include <asm-generic/$*.h>" >$@
all: $(patsubst %, $(obj)/%, $(generic-y))
$(obj)/%.h:
$(call cmd,wrap)
...@@ -27,8 +27,13 @@ header-y := $(filter-out %/, $(header-y)) ...@@ -27,8 +27,13 @@ header-y := $(filter-out %/, $(header-y))
install-file := $(install)/.install install-file := $(install)/.install
check-file := $(install)/.check check-file := $(install)/.check
# generic-y list all files an architecture uses from asm-generic
# Use this to build a list of headers which require a wrapper
wrapper-files := $(filter $(header-y), $(generic-y))
# all headers files for this dir # all headers files for this dir
all-files := $(header-y) $(objhdr-y) header-y := $(filter-out $(generic-y), $(header-y))
all-files := $(header-y) $(objhdr-y) $(wrapper-files)
input-files := $(addprefix $(srctree)/$(obj)/,$(header-y)) \ input-files := $(addprefix $(srctree)/$(obj)/,$(header-y)) \
$(addprefix $(objtree)/$(obj)/,$(objhdr-y)) $(addprefix $(objtree)/$(obj)/,$(objhdr-y))
output-files := $(addprefix $(install)/, $(all-files)) output-files := $(addprefix $(install)/, $(all-files))
...@@ -47,6 +52,9 @@ quiet_cmd_install = INSTALL $(printdir) ($(words $(all-files))\ ...@@ -47,6 +52,9 @@ quiet_cmd_install = INSTALL $(printdir) ($(words $(all-files))\
cmd_install = \ cmd_install = \
$(PERL) $< $(srctree)/$(obj) $(install) $(SRCARCH) $(header-y); \ $(PERL) $< $(srctree)/$(obj) $(install) $(SRCARCH) $(header-y); \
$(PERL) $< $(objtree)/$(obj) $(install) $(SRCARCH) $(objhdr-y); \ $(PERL) $< $(objtree)/$(obj) $(install) $(SRCARCH) $(objhdr-y); \
for F in $(wrapper-files); do \
echo "\#include <asm-generic/$$F>" > $(install)/$$F; \
done; \
touch $@ touch $@
quiet_cmd_remove = REMOVE $(unwanted) quiet_cmd_remove = REMOVE $(unwanted)
......
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