[PATCH 3/3] s390/syscalls: convert filechk to if_changed

[Masahiro Yamada <masahiroy@kernel.org>]

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 <masahiroy@kernel.org>
---

 arch/s390/kernel/syscalls/Makefile | 25 ++++++++++++++-----------
 1 file changed, 14 insertions(+), 11 deletions(-)

diff --git a/arch/s390/kernel/syscalls/Makefile b/arch/s390/kernel/syscalls/Makefile
index 3725dd88428c..c5d958a09ff4 100644
--- a/arch/s390/kernel/syscalls/Makefile
+++ b/arch/s390/kernel/syscalls/Makefile
@@ -23,23 +23,26 @@ uapi:	$(uapi-hdrs-y)
 # Create output directory if not already present
 $(shell mkdir -p $(uapi) $(kapi))
 
-filechk_syshdr = $(CONFIG_SHELL) '$(systbl)' -H -a $(syshdr_abi_$(basetarget)) -f "$@" < $<
+quiet_cmd_syshdr = SYSHDR  $@
+      cmd_syshdr = $(CONFIG_SHELL) '$(systbl)' -H -a $(syshdr_abi_$(basetarget)) -f "$@" < $< > $@
 
-filechk_sysnr = $(CONFIG_SHELL) '$(systbl)' -N -a $(sysnr_abi_$(basetarget)) < $<
+quiet_cmd_sysnr = SYSNR   $@
+      cmd_sysnr = $(CONFIG_SHELL) '$(systbl)' -N -a $(sysnr_abi_$(basetarget)) < $< > $@
 
-filechk_syscalls = $(CONFIG_SHELL) '$(systbl)' -S < $<
+quiet_cmd_syscalls = SYSTBL  $@
+      cmd_syscalls = $(CONFIG_SHELL) '$(systbl)' -S < $< > $@
 
 syshdr_abi_unistd_32 := common,32
-$(uapi)/unistd_32.h: $(syscall) FORCE
-	$(call filechk,syshdr)
+$(uapi)/unistd_32.h: $(syscall) $(systbl) FORCE
+	$(call if_changed,syshdr)
 
 syshdr_abi_unistd_64 := common,64
-$(uapi)/unistd_64.h: $(syscall) FORCE
-	$(call filechk,syshdr)
+$(uapi)/unistd_64.h: $(syscall) $(systbl) FORCE
+	$(call if_changed,syshdr)
 
-$(kapi)/syscall_table.h: $(syscall) FORCE
-	$(call filechk,syscalls)
+$(kapi)/syscall_table.h: $(syscall) $(systbl) FORCE
+	$(call if_changed,syscalls)
 
 sysnr_abi_unistd_nr := common,32,64
-$(kapi)/unistd_nr.h: $(syscall) FORCE
-	$(call filechk,sysnr)
+$(kapi)/unistd_nr.h: $(syscall) $(systbl) FORCE
+	$(call if_changed,sysnr)
-- 
2.43.0