[PATCH 1/2] kbuild: asm-generic support
From: Sam Ravnborg
Date: Sun Jan 09 2011 - 13:45:40 EST
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 is used a different method.
The patch includes several improvements from Arnd Bergmann.
Signed-off-by: Sam Ravnborg <sam@xxxxxxxxxxxx>
Cc: Guan Xuetao <guanxuetao@xxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
---
.gitignore | 1 +
Documentation/kbuild/makefiles.txt | 36 ++++++++++++++++++++++++++++++++++++
Makefile | 15 +++++++++++----
scripts/Makefile.headersinst | 18 +++++++++++++++---
scripts/asm-generic.sh | 33 +++++++++++++++++++++++++++++++++
5 files changed, 96 insertions(+), 7 deletions(-)
create mode 100644 scripts/asm-generic.sh
diff --git a/.gitignore b/.gitignore
index 8faa6c0..e3cfd57 100644
--- a/.gitignore
+++ b/.gitignore
@@ -56,6 +56,7 @@ modules.builtin
include/config
include/linux/version.h
include/generated
+arch/*/include/generated
# stgit generated dirs
patches-*
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index 0ef00bd..bc79a3d 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -40,11 +40,13 @@ This document describes the Linux kernel Makefiles.
--- 6.6 Commands useful for building a boot image
--- 6.7 Custom kbuild commands
--- 6.8 Preprocessing linker scripts
+ --- 6.9 Generic header files
=== 7 Kbuild syntax for exported headers
--- 7.1 header-y
--- 7.2 objhdr-y
--- 7.3 destination-y
+ --- 7.4 generic-y
=== 8 Kbuild Variables
=== 9 Makefile language
@@ -1194,6 +1196,14 @@ When kbuild executes, the following steps are followed (roughly):
The kbuild infrastructure for *lds file are used in several
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
The kernel include a set of headers that is exported to userspace.
@@ -1250,6 +1260,32 @@ See subsequent chapter for the syntax of the Kbuild file.
In the example above all exported headers in the Kbuild file
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
diff --git a/Makefile b/Makefile
index 74b2555..263eb65 100644
--- a/Makefile
+++ b/Makefile
@@ -344,7 +344,8 @@ CFLAGS_GCOV = -fprofile-arcs -ftest-coverage
# Use LINUXINCLUDE when you must reference the include/ directory.
# 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) \
-include include/generated/autoconf.h
@@ -411,6 +412,11 @@ ifneq ($(KBUILD_SRC),)
$(srctree) $(objtree) $(VERSION) $(PATCHLEVEL)
endif
+# Support for using generic headers in asm-generic
+PHONY += asm-generic
+asm-generic:
+ $(Q)$(CONFIG_SHELL) $(srctree)/scripts/asm-generic.sh $(SRCARCH)
+
# To make sure we do not include .config for any of the *config targets
# catch them early, and hand them over to scripts/kconfig/Makefile
# It is allowed to specify more targets when calling make, including
@@ -942,7 +948,7 @@ ifneq ($(KBUILD_SRC),)
endif
# 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 \
include/config/auto.conf
@@ -1016,7 +1022,7 @@ hdr-inst := -rR -f $(srctree)/scripts/Makefile.headersinst obj
hdr-dst = $(if $(KBUILD_HEADERS), dst=include/asm-$(hdr-arch), dst=include/asm)
PHONY += __headers
-__headers: include/linux/version.h scripts_basic FORCE
+__headers: include/linux/version.h scripts_basic asm-generic FORCE
$(Q)$(MAKE) $(build)=scripts scripts/unifdef
PHONY += headers_install_all
@@ -1131,7 +1137,8 @@ CLEAN_FILES += vmlinux System.map \
.tmp_kallsyms* .tmp_version .tmp_vmlinux* .tmp_System.map
# 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 \
include/linux/version.h \
Module.symvers tags TAGS cscope*
diff --git a/scripts/Makefile.headersinst b/scripts/Makefile.headersinst
index f89cb87..7960b19 100644
--- a/scripts/Makefile.headersinst
+++ b/scripts/Makefile.headersinst
@@ -14,6 +14,7 @@ kbuild-file := $(srctree)/$(obj)/Kbuild
include $(kbuild-file)
_dst := $(if $(destination-y),$(destination-y),$(_dst))
+_src := $(srctree)/$(obj)
include scripts/Kbuild.include
@@ -27,10 +28,16 @@ header-y := $(filter-out %/, $(header-y))
install-file := $(install)/.install
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-files := $(header-y) $(objhdr-y)
-input-files := $(addprefix $(srctree)/$(obj)/,$(header-y)) \
+header-y := $(filter-out $(generic-y), $(header-y))
+all-files := $(header-y) $(objhdr-y) $(wrapper-files)
+input-files := $(addprefix $(_src)/,$(header-y)) \
$(addprefix $(objtree)/$(obj)/,$(objhdr-y))
+
output-files := $(addprefix $(install)/, $(all-files))
# Work out what needs to be removed
@@ -47,8 +54,12 @@ quiet_cmd_install = INSTALL $(printdir) ($(words $(all-files))\
cmd_install = \
$(PERL) $< $(srctree)/$(obj) $(install) $(SRCARCH) $(header-y); \
$(PERL) $< $(objtree)/$(obj) $(install) $(SRCARCH) $(objhdr-y); \
+ for F in $(wrapper-files); do \
+ echo "\#include <asm-generic/$$F>" > $(install)/$$F; \
+ done; \
touch $@
+
quiet_cmd_remove = REMOVE $(unwanted)
cmd_remove = rm -f $(unwanted-file)
@@ -69,7 +80,8 @@ __headersinst: $(subdirs) $(install-file)
@:
targets += $(install-file)
-$(install-file): scripts/headers_install.pl $(input-files) FORCE
+$(install-file): scripts/headers_install.pl \
+ $(input-files) FORCE
$(if $(unwanted),$(call cmd,remove),)
$(if $(wildcard $(dir $@)),,$(shell mkdir -p $(dir $@)))
$(call if_changed,install)
diff --git a/scripts/asm-generic.sh b/scripts/asm-generic.sh
new file mode 100644
index 0000000..d28127f
--- /dev/null
+++ b/scripts/asm-generic.sh
@@ -0,0 +1,33 @@
+#!/bin/sh
+#
+# include/asm-generic contains a lot of files that are used
+# verbatim by several architectures.
+#
+# This scripts read the file arch/$(ARCH)/include/asm/Kbuild
+# and for each file listed in this file with generic-y create
+# a small wrapper file in arch/$(ARCH)/include/generated/
+
+# read list of header files form Kbuild
+# The file has make syntax which looks like this:
+#
+# generic-y += <filename>
+
+srcdir=${srctree}/arch/$1/include/asm
+gendir=arch/$1/include/generated/asm
+
+# Read the list of files (note that the list uses make syntax)
+files=$( cat ${srcdir}/Kbuild | \
+ grep -v ^# | grep generic-y | cut -d '=' -f 2)
+
+mkdir -p ${gendir}
+
+# create include files for each file used form asm-generic
+for F in ${files}; do
+ if [ -f ${srcdir}/$F ]; then
+ echo "ERROR: ${srcdir}/$F exists"
+ echo "$F is also listed as generic-y in ${srcdir}/Kbuild"
+ echo "Did you forget to remove the file?"
+ exit 1
+ fi
+ echo "#include <asm-generic/$F>" > ${gendir}/$F
+done
--
1.6.0.6
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