diff --git a/.gitignore b/.gitignore
index 869e1a3b64b..51bd99d6a26 100644
--- a/.gitignore
+++ b/.gitignore
@@ -49,6 +49,7 @@ include/linux/compile.h
 include/linux/version.h
 include/linux/utsrelease.h
 include/linux/bounds.h
+include/generated
 
 # stgit generated dirs
 patches-*
diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt
index d4b05672f9f..d76cfd8712e 100644
--- a/Documentation/kbuild/makefiles.txt
+++ b/Documentation/kbuild/makefiles.txt
@@ -316,6 +316,16 @@ more details, with real examples.
 		#arch/m68k/fpsp040/Makefile
 		ldflags-y := -x
 
+    subdir-ccflags-y, subdir-asflags-y
+	The two flags listed above are similar to ccflags-y and as-falgs-y.
+	The difference is that the subdir- variants has effect for the kbuild
+	file where tey are present and all subdirectories.
+	Options specified using subdir-* are added to the commandline before
+	the options specified using the non-subdir variants.
+
+	Example:
+		subdir-ccflags-y := -Werror
+
     CFLAGS_$@, AFLAGS_$@
 
 	CFLAGS_$@ and AFLAGS_$@ only apply to commands in current
diff --git a/Makefile b/Makefile
index bfdef56add3..6f4208ff2d1 100644
--- a/Makefile
+++ b/Makefile
@@ -1200,7 +1200,7 @@ CLEAN_FILES +=	vmlinux System.map \
                 .tmp_kallsyms* .tmp_version .tmp_vmlinux* .tmp_System.map
 
 # Directories & files removed with 'make mrproper'
-MRPROPER_DIRS  += include/config include2 usr/include
+MRPROPER_DIRS  += include/config include2 usr/include include/generated
 MRPROPER_FILES += .config .config.old include/asm .version .old_version \
                   include/linux/autoconf.h include/linux/version.h      \
                   include/linux/utsrelease.h                            \
diff --git a/scripts/Makefile.build b/scripts/Makefile.build
index 39a9642927d..5c4b7a400c1 100644
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -27,6 +27,9 @@ ccflags-y  :=
 cppflags-y :=
 ldflags-y  :=
 
+subdir-asflags-y :=
+subdir-ccflags-y :=
+
 # Read auto.conf if it exists, otherwise ignore
 -include include/config/auto.conf
 
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 979619574f7..cba61ca403c 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -4,6 +4,11 @@ ccflags-y  += $(EXTRA_CFLAGS)
 cppflags-y += $(EXTRA_CPPFLAGS)
 ldflags-y  += $(EXTRA_LDFLAGS)
 
+#
+# flags that take effect in sub directories
+export KBUILD_SUBDIR_ASFLAGS := $(KBUILD_SUBDIR_ASFLAGS) $(subdir-asflags-y)
+export KBUILD_SUBDIR_CCFLAGS := $(KBUILD_SUBDIR_CCFLAGS) $(subdir-ccflags-y)
+
 # Figure out what we need to build from the various variables
 # ===========================================================================
 
@@ -104,10 +109,10 @@ else
 debug_flags =
 endif
 
-orig_c_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)                     \
+orig_c_flags   = $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(KBUILD_SUBDIR_CCFLAGS) \
                  $(ccflags-y) $(CFLAGS_$(basetarget).o)
 _c_flags       = $(filter-out $(CFLAGS_REMOVE_$(basetarget).o), $(orig_c_flags))
-_a_flags       = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS)                     \
+_a_flags       = $(KBUILD_CPPFLAGS) $(KBUILD_AFLAGS) $(KBUILD_SUBDIR_ASFLAGS) \
                  $(asflags-y) $(AFLAGS_$(basetarget).o)
 _cpp_flags     = $(KBUILD_CPPFLAGS) $(cppflags-y) $(CPPFLAGS_$(@F))