selftests: Add infrastructure for powerpc selftests

This commit adds a powerpc subdirectory to tools/testing/selftests,
for tests that are powerpc specific.

On other architectures nothing is built. The makefile supports cross
compilation if the user sets ARCH and CROSS_COMPILE.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

tools/testing/selftests/Makefile

@@ -8,6 +8,7 @@ TARGETS += net
 TARGETS += ptrace
 TARGETS += timers
 TARGETS += vm
+TARGETS += powerpc
 
 all:
 	for TARGET in $(TARGETS); do \

tools/testing/selftests/powerpc/Makefile

@@ -0,0 +1,39 @@
+# Makefile for powerpc selftests
+
+# ARCH can be overridden by the user for cross compiling
+ARCH ?= $(shell uname -m)
+ARCH := $(shell echo $(ARCH) | sed -e s/ppc.*/powerpc/)
+
+ifeq ($(ARCH),powerpc)
+
+GIT_VERSION = $(shell git describe --always --long --dirty || echo "unknown")
+
+CC := $(CROSS_COMPILE)$(CC)
+CFLAGS := -Wall -O2 -flto -Wall -Werror -DGIT_VERSION='"$(GIT_VERSION)"' -I$(CURDIR) $(CFLAGS)
+
+export CC CFLAGS
+
+TARGETS =
+
+endif
+
+all:
+	@for TARGET in $(TARGETS); do \
+		$(MAKE) -C $$TARGET all; \
+	done;
+
+run_tests: all
+	@for TARGET in $(TARGETS); do \
+		$(MAKE) -C $$TARGET run_tests; \
+	done;
+
+clean:
+	@for TARGET in $(TARGETS); do \
+		$(MAKE) -C $$TARGET clean; \
+	done;
+	rm -f tags
+
+tags:
+	find . -name '*.c' -o -name '*.h' | xargs ctags
+
+.PHONY: all run_tests clean tags