selftests/powerpc: Don't run DSCR tests on old systems

The DSCR tests fail on systems that don't have DSCR, so check for the
DSCR in hwcap and skip if it's not present.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200819015727.1977134-5-mpe@ellerman.id.au

tools/testing/selftests/powerpc/dscr/Makefile

@@ -10,4 +10,4 @@ include ../../lib.mk
 
 $(OUTPUT)/dscr_default_test: LDLIBS += -lpthread
 
-$(TEST_GEN_PROGS): ../harness.c
+$(TEST_GEN_PROGS): ../harness.c ../utils.c

tools/testing/selftests/powerpc/dscr/dscr_default_test.c

@@ -63,6 +63,8 @@ int dscr_default(void)
 	unsigned long i, *status[THREADS];
 	unsigned long orig_dscr_default;
 
+	SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
+
 	orig_dscr_default = get_default_dscr();
 
 	/* Initial DSCR default */

tools/testing/selftests/powerpc/dscr/dscr_explicit_test.c

@@ -21,6 +21,8 @@ int dscr_explicit(void)
 {
 	unsigned long i, dscr = 0;
 
+	SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
+
 	srand(getpid());
 	set_dscr(dscr);
 

tools/testing/selftests/powerpc/dscr/dscr_inherit_exec_test.c

@@ -44,6 +44,8 @@ int dscr_inherit_exec(void)
 	unsigned long i, dscr = 0;
 	pid_t pid;
 
+	SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
+
 	for (i = 0; i < COUNT; i++) {
 		dscr++;
 		if (dscr > DSCR_MAX)

tools/testing/selftests/powerpc/dscr/dscr_inherit_test.c

@@ -22,6 +22,8 @@ int dscr_inherit(void)
 	unsigned long i, dscr = 0;
 	pid_t pid;
 
+	SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
+
 	srand(getpid());
 	set_dscr(dscr);
 

tools/testing/selftests/powerpc/dscr/dscr_sysfs_test.c

@@ -77,6 +77,8 @@ int dscr_sysfs(void)
 	unsigned long orig_dscr_default;
 	int i, j;
 
+	SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
+
 	orig_dscr_default = get_default_dscr();
 	for (i = 0; i < COUNT; i++) {
 		for (j = 0; j < DSCR_MAX; j++) {

tools/testing/selftests/powerpc/dscr/dscr_sysfs_thread_test.c

@@ -56,6 +56,8 @@ int dscr_sysfs_thread(void)
 	unsigned long orig_dscr_default;
 	int i, j;
 
+	SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
+
 	orig_dscr_default = get_default_dscr();
 	for (i = 0; i < COUNT; i++) {
 		for (j = 0; j < DSCR_MAX; j++) {

tools/testing/selftests/powerpc/dscr/dscr_user_test.c

@@ -36,6 +36,8 @@ int dscr_user(void)
 {
 	int i;
 
+	SKIP_IF(!have_hwcap2(PPC_FEATURE2_DSCR));
+
 	check_dscr("");
 
 	for (i = 0; i < COUNT; i++) {