tools: Define a Makefile function to do subdir processing

Define a Makefile function that can be called with $(call ...) to wrap
the subdir make invocations in tools/Makefile.

This will allow us in the next patch to insert bits in there to honour
O= flags when called from the top-level Makefile.
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Borislav Petkov <bp@amd64.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1378.1352379110@warthog.procyon.org.ukSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/Makefile

@@ -31,44 +31,44 @@ help:
 	@echo '  clean: a summary clean target to clean _all_ folders'
 
 cpupower: FORCE
-	$(QUIET_SUBDIR0)power/$@/ $(QUIET_SUBDIR1)
+	$(call descend,power/$@)
 
 firewire lguest perf usb virtio vm: FORCE
-	$(QUIET_SUBDIR0)$@/ $(QUIET_SUBDIR1)
+	$(call descend,$@)
 
 selftests: FORCE
-	$(QUIET_SUBDIR0)testing/$@/ $(QUIET_SUBDIR1)
+	$(call descend,testing/$@)
 
 turbostat x86_energy_perf_policy: FORCE
-	$(QUIET_SUBDIR0)power/x86/$@/ $(QUIET_SUBDIR1)
+	$(call descend,power/x86/$@)
 
 cpupower_install:
-	$(QUIET_SUBDIR0)power/$(@:_install=)/ $(QUIET_SUBDIR1) install
+	$(call descend,power/$(@:_install=),install)
 
 firewire_install lguest_install perf_install usb_install virtio_install vm_install:
-	$(QUIET_SUBDIR0)$(@:_install=)/ $(QUIET_SUBDIR1) install
+	$(call descend,$(@:_install=),install)
 
 selftests_install:
-	$(QUIET_SUBDIR0)testing/$(@:_clean=)/ $(QUIET_SUBDIR1) install
+	$(call descend,testing/$(@:_clean=),install)
 
 turbostat_install x86_energy_perf_policy_install:
-	$(QUIET_SUBDIR0)power/x86/$(@:_install=)/ $(QUIET_SUBDIR1) install
+	$(call descend,power/x86/$(@:_install=),install)
 
 install: cpupower_install firewire_install lguest_install perf_install \
 		selftests_install turbostat_install usb_install virtio_install \
 		vm_install x86_energy_perf_policy_install
 
 cpupower_clean:
-	$(QUIET_SUBDIR0)power/cpupower/ $(QUIET_SUBDIR1) clean
+	$(call descend,power/cpupower,clean)
 
 firewire_clean lguest_clean perf_clean usb_clean virtio_clean vm_clean:
-	$(QUIET_SUBDIR0)$(@:_clean=)/ $(QUIET_SUBDIR1) clean
+	$(call descend,$(@:_clean=),clean)
 
 selftests_clean:
-	$(QUIET_SUBDIR0)testing/$(@:_clean=)/ $(QUIET_SUBDIR1) clean
+	$(call descend,testing/$(@:_clean=),clean)
 
 turbostat_clean x86_energy_perf_policy_clean:
-	$(QUIET_SUBDIR0)power/x86/$(@:_clean=)/ $(QUIET_SUBDIR1) clean
+	$(call descend,power/x86/$(@:_clean=),clean)
 
 clean: cpupower_clean firewire_clean lguest_clean perf_clean selftests_clean \
 		turbostat_clean usb_clean virtio_clean vm_clean \

tools/scripts/Makefile.include

@@ -41,6 +41,14 @@ else
 NO_SUBDIR = :
 endif
 
+#
+# Define a callable command for descending to a new directory
+#
+# Call by doing: $(call descend,directory[,target])
+#
+descend = \
+	$(QUIET_SUBDIR0)$(1) $(QUIET_SUBDIR1) $(2)
+
 QUIET_SUBDIR0  = +$(MAKE) -C # space to separate -C and subdir
 QUIET_SUBDIR1  =