UAPI: Partition the header include path sets and add uapi/ header directories

Partition the header include path flags into two sets, one for kernelspace
builds and one for userspace builds.

Add the following directories to build after the ordinary include directories
so that #include will pick up the UAPI header directly if the kernel header
has been moved there.

The userspace set (represented by the USERINCLUDE make variable) contains:

	-I $(srctree)/arch/$(hdr-arch)/include/uapi
	-I arch/$(hdr-arch)/include/generated/uapi
	-I $(srctree)/include/uapi
	-I include/generated/uapi
	-include $(srctree)/include/linux/kconfig.h

and the kernelspace set (represented by the LINUXINCLUDE make variable)
contains:

	-I $(srctree)/arch/$(hdr-arch)/include
	-I arch/$(hdr-arch)/include/generated
	-I $(srctree)/include
	-I include		--- if not building in the source tree

plus everything in the USERINCLUDE set.

Then use USERINCLUDE in building the x86 boot code.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Dave Jones <davej@redhat.com>

Makefile

@@ -350,12 +350,22 @@ AFLAGS_KERNEL	=
 CFLAGS_GCOV	= -fprofile-arcs -ftest-coverage
 
 
+# Use USERINCLUDE when you must reference the UAPI directories only.
+USERINCLUDE    := \
+		-I$(srctree)/arch/$(hdr-arch)/include/uapi \
+		-Iarch/$(hdr-arch)/include/generated/uapi \
+		-I$(srctree)/include/uapi \
+		-Iinclude/generated/uapi \
+                -include $(srctree)/include/linux/kconfig.h
+
 # Use LINUXINCLUDE when you must reference the include/ directory.
 # Needed to be compatible with the O= option
-LINUXINCLUDE    := -I$(srctree)/arch/$(hdr-arch)/include \
-                   -Iarch/$(hdr-arch)/include/generated -Iinclude \
+LINUXINCLUDE    := \
+		-I$(srctree)/arch/$(hdr-arch)/include \
+		-Iarch/$(hdr-arch)/include/generated \
 		$(if $(KBUILD_SRC), -I$(srctree)/include) \
-                   -include $(srctree)/include/linux/kconfig.h
+		-Iinclude \
+		$(USERINCLUDE)
 
 KBUILD_CPPFLAGS := -D__KERNEL__
 

arch/cris/Makefile

@@ -23,7 +23,9 @@ mach-$(CONFIG_ETRAXFS) := fs
 
 ifneq ($(arch-y),)
 SARCH := arch-$(arch-y)
-inc := -Iarch/cris/include/$(SARCH)
+inc := -Iarch/cris/include/uapi/$(SARCH)
+inc += -Iarch/cris/include/$(SARCH)
+inc += -Iarch/cris/include/uapi/$(SARCH)/arch
 inc += -Iarch/cris/include/$(SARCH)/arch
 else
 SARCH :=

arch/um/Makefile

@@ -66,7 +66,9 @@ USER_CFLAGS = $(patsubst $(KERNEL_DEFINES),,$(patsubst -D__KERNEL__,,\
 include $(srctree)/$(ARCH_DIR)/Makefile-os-$(OS)
 
 KBUILD_CPPFLAGS += -I$(srctree)/$(HOST_DIR)/include \
-		   -I$(HOST_DIR)/include/generated
+		   -I$(srctree)/$(HOST_DIR)/include/uapi \
+		   -I$(HOST_DIR)/include/generated \
+		   -I$(HOST_DIR)/include/generated/uapi
 
 # -Derrno=kernel_errno - This turns all kernel references to errno into
 # kernel_errno to separate them from the libc errno.  This allows -fno-common

arch/x86/boot/Makefile

@@ -37,7 +37,7 @@ setup-y		+= video-bios.o
 targets		+= $(setup-y)
 hostprogs-y	:= mkcpustr tools/build
 
-HOST_EXTRACFLAGS += -I$(srctree)/tools/include $(LINUXINCLUDE) \
+HOST_EXTRACFLAGS += -I$(srctree)/tools/include $(USERINCLUDE) \
 	            -D__EXPORTED_HEADERS__
 
 $(obj)/cpu.o: $(obj)/cpustr.h
@@ -52,7 +52,7 @@ $(obj)/cpustr.h: $(obj)/mkcpustr FORCE
 
 # How to compile the 16-bit code.  Note we always compile for -march=i386,
 # that way we can complain to the user if the CPU is insufficient.
-KBUILD_CFLAGS	:= $(LINUXINCLUDE) -g -Os -D_SETUP -D__KERNEL__ \
+KBUILD_CFLAGS	:= $(USERINCLUDE) -g -Os -D_SETUP -D__KERNEL__ \
 		   -DDISABLE_BRANCH_PROFILING \
 		   -Wall -Wstrict-prototypes \
 		   -march=i386 -mregparm=3 \

arch/x86/boot/mkcpustr.c

@@ -15,6 +15,8 @@
 
 #include <stdio.h>
 
+#include "../include/asm/required-features.h"
+#include "../include/asm/cpufeature.h"
 #include "../kernel/cpu/capflags.c"
 
 int main(void)

arch/x86/include/asm/cpufeature.h

@@ -4,7 +4,9 @@
 #ifndef _ASM_X86_CPUFEATURE_H
 #define _ASM_X86_CPUFEATURE_H
 
+#ifndef _ASM_X86_REQUIRED_FEATURES_H
 #include <asm/required-features.h>
+#endif
 
 #define NCAPINTS	10	/* N 32-bit words worth of info */
 

arch/x86/kernel/cpu/mkcapflags.pl

@@ -8,7 +8,10 @@
 open(IN, "< $in\0")   or die "$0: cannot open: $in: $!\n";
 open(OUT, "> $out\0") or die "$0: cannot create: $out: $!\n";
 
-print OUT "#include <asm/cpufeature.h>\n\n";
+print OUT "#ifndef _ASM_X86_CPUFEATURE_H\n";
+print OUT "#include <asm/cpufeature.h>\n";
+print OUT "#endif\n";
+print OUT "\n";
 print OUT "const char * const x86_cap_flags[NCAPINTS*32] = {\n";
 
 %features = ();