[ Upstream commit 0708967e2d56e370231fd07defa0d69f9ad125e8 ]

Building the kernel with ARCH=s390 creates a weird arch/arch/ directory.

  $ find arch/arch
  arch/arch
  arch/arch/s390
  arch/arch/s390/include
  arch/arch/s390/include/generated
  arch/arch/s390/include/generated/asm
  arch/arch/s390/include/generated/uapi
  arch/arch/s390/include/generated/uapi/asm

The root cause is 'targets' in arch/s390/kernel/syscalls/Makefile,
where the relative path is incorrect.

Strictly speaking, 'targets' was not necessary in the first place
because this Makefile uses 'filechk' instead of 'if_changed'.

However, this commit keeps it, as it will be useful when converting
'filechk' to 'if_changed' later.

Fixes: 5c75824d915e ("s390/syscalls: add Makefile to generate system call header files")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20241111134603.2063226-1-masahiroy@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

You do not have to use define ... endef for filechk_* rules.

For simple cases, the use of assignment looks cleaner, IMHO.

I updated the usage for scripts/Kbuild.include in case somebody
misunderstands the 'define ... endif' is the requirement.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>

Currently, filechk unconditionally opens the first prerequisite and
redirects it as the stdin of a filechk_* rule.  Hence, every target
using $(call filechk,...) must list something as the first prerequisite
even if it is unneeded.

'< $<' is actually unneeded in most cases.  Each rule can explicitly
adds it if necessary.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Generate the system call specific files from the archheaders
and archprepare make targets.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>