From 919987318a129b4d0c2203a3c6fd2d804be77100 Mon Sep 17 00:00:00 2001 From: Masahiro Yamada Date: Thu, 3 Jan 2019 10:10:38 +0900 Subject: kbuild: generate asm-generic wrappers if mandatory headers are missing Some time ago, Sam pointed out a certain degree of overwrap between generic-y and mandatory-y. (https://lkml.org/lkml/2017/7/10/121) I tweaked the meaning of mandatory-y a little bit; now it defines the minimum set of ASM headers that all architectures must have. If arch does not have specific implementation of a mandatory header, Kbuild will let it fallback to the asm-generic one by automatically generating a wrapper. This will allow to drop lots of redundant generic-y defines. Previously, "mandatory" was used in the context of UAPI, but I guess this can be extended to kernel space ASM headers. Suggested-by: Sam Ravnborg Signed-off-by: Masahiro Yamada Acked-by: Sam Ravnborg --- Documentation/kbuild/makefiles.txt | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'Documentation') diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index 8da26c6dd886..bf28c47bfd72 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt @@ -1296,9 +1296,12 @@ See subsequent chapter for the syntax of the Kbuild file. --- 7.4 mandatory-y - mandatory-y is essentially used by include/uapi/asm-generic/Kbuild.asm - to define the minimum set of headers that must be exported in - include/asm. + mandatory-y is essentially used by include/(uapi/)asm-generic/Kbuild.asm + to define the minimum set of ASM headers that all architectures must have. + + This works like optional generic-y. If a mandatory header is missing + in arch/$(ARCH)/include/(uapi/)/asm, Kbuild will automatically generate + a wrapper of the asm-generic one. The convention is to list one subdir per line and preferably in alphabetic order. -- cgit v1.2.3-59-g8ed1b