selftests: Add test of PMU instruction counting on powerpc

This commit adds a test of instruction counting using the PMU on powerpc.

Although the bulk of the code is architecture agnostic, the code needs to
run a precisely sized loop which is implemented in assembler.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/tools/testing/selftests/powerpc/pmu/Makefile b/tools/testing/selftests/powerpc/pmu/Makefile
new file mode 100644
index 0000000..7216f00
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/Makefile
@@ -0,0 +1,23 @@
+noarg:
+	$(MAKE) -C ../
+
+PROGS := count_instructions
+EXTRA_SOURCES := ../harness.c event.c
+
+all: $(PROGS)
+
+$(PROGS): $(EXTRA_SOURCES)
+
+# loop.S can only be built 64-bit
+count_instructions: loop.S count_instructions.c $(EXTRA_SOURCES)
+	$(CC) $(CFLAGS) -m64 -o $@ $^
+
+run_tests: all
+	@-for PROG in $(PROGS); do \
+		./$$PROG; \
+	done;
+
+clean:
+	rm -f $(PROGS) loop.o
+
+.PHONY: all run_tests clean