s390/syscalls: Convert filechk to if_changed

The filechk macro always executes the syscalltbl script (and discards
the output if there are no changes).

Using if_changed is more efficient because it

s390/syscalls: Convert filechk to if_changed

The filechk macro always executes the syscalltbl script (and discards
the output if there are no changes).

Using if_changed is more efficient because it avoids running the script
when the target is up-to-date and the command remains unchanged.

All other architectures use if_changed for generating syscall headers.

Signed-off-by: Masahiro Yamada <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Heiko Carstens <[email protected]>

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s390/syscalls: Remove unnecessary argument of filechk_syshdr

The filechk_syshdr macro receives $@ in both cases, making the argument
redundant.

Signed-off-by: Masahiro Yamada <[email protected]>

s390/syscalls: Remove unnecessary argument of filechk_syshdr

The filechk_syshdr macro receives $@ in both cases, making the argument
redundant.

Signed-off-by: Masahiro Yamada <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Heiko Carstens <[email protected]>

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s390/syscalls: Avoid creation of arch/arch/ directory

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

$ find arch/arch
arch/arch
arch/arch/s390
arch/arch/s390/inclu

s390/syscalls: Avoid creation of arch/arch/ directory

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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Heiko Carstens <[email protected]>

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kbuild: use $(src) instead of $(srctree)/$(src) for source directory

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention withou

kbuild: use $(src) instead of $(srctree)/$(src) for source directory

Kbuild conventionally uses $(obj)/ for generated files, and $(src)/ for
checked-in source files. It is merely a convention without any functional
difference. In fact, $(obj) and $(src) are exactly the same, as defined
in scripts/Makefile.build:

src := $(obj)

When the kernel is built in a separate output directory, $(src) does
not accurately reflect the source directory location. While Kbuild
resolves this discrepancy by specifying VPATH=$(srctree) to search for
source files, it does not cover all cases. For example, when adding a
header search path for local headers, -I$(srctree)/$(src) is typically
passed to the compiler.

This introduces inconsistency between upstream and downstream Makefiles
because $(src) is used instead of $(srctree)/$(src) for the latter.

To address this inconsistency, this commit changes the semantics of
$(src) so that it always points to the directory in the source tree.

Going forward, the variables used in Makefiles will have the following
meanings:

$(obj) - directory in the object tree
$(src) - directory in the source tree (changed by this commit)
$(objtree) - the top of the kernel object tree
$(srctree) - the top of the kernel source tree

Consequently, $(srctree)/$(src) in upstream Makefiles need to be replaced
with $(src).

Signed-off-by: Masahiro Yamada <[email protected]>
Reviewed-by: Nicolas Schier <[email protected]>

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arch: syscalls: simplify uapi/kapi directory creation

$(shell ...) expands to empty. There is no need to assign it to _dummy.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Geert U

arch: syscalls: simplify uapi/kapi directory creation

$(shell ...) expands to empty. There is no need to assign it to _dummy.

Signed-off-by: Masahiro Yamada <[email protected]>
Acked-by: Geert Uytterhoeven <[email protected]>

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kbuild: use assignment instead of define ... endef for filechk_* rules

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

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

I u

kbuild: use assignment instead of define ... endef for filechk_* rules

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 <[email protected]>
Acked-by: Heiko Carstens <[email protected]>

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kbuild: do not redirect the first prerequisite for filechk

Currently, filechk unconditionally opens the first prerequisite and
redirects it as the stdin of a filechk_* rule. Hence, every target
usi

kbuild: do not redirect the first prerequisite for filechk

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 <[email protected]>

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s390/syscalls: add Makefile to generate system call header files

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

Signed-off-by: Hendrik Brueckner <brueckn

s390/syscalls: add Makefile to generate system call header files

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

Signed-off-by: Hendrik Brueckner <[email protected]>
Acked-by: Heiko Carstens <[email protected]>
Signed-off-by: Martin Schwidefsky <[email protected]>

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