selftests/powerpc/pmu: Add selftest for reserved bit check for MMCRA thresh_ctl field

Testcase for reserved bits in Monitor Mode Control Register A (MMCRA)
thresh_ctl bits. For MMCRA[48:51]/[52:55]) Threshold Start/Stop,
0b11110000/0b00001111 is reserved.
Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220610134113.62991-25-atrajeev@linux.vnet.ibm.com

tools/testing/selftests/powerpc/pmu/event_code_tests/Makefile

@@ -3,7 +3,7 @@ CFLAGS += -m64
 
 TEST_GEN_PROGS := group_constraint_pmc56_test group_pmc56_exclude_constraints_test group_constraint_pmc_count_test \
 	group_constraint_repeat_test group_constraint_radix_scope_qual_test reserved_bits_mmcra_sample_elig_mode_test \
-	group_constraint_mmcra_sample_test invalid_event_code_test
+	group_constraint_mmcra_sample_test invalid_event_code_test reserved_bits_mmcra_thresh_ctl_test
 
 top_srcdir = ../../../../../..
 include ../../../lib.mk

tools/testing/selftests/powerpc/pmu/event_code_tests/reserved_bits_mmcra_thresh_ctl_test.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2022, Athira Rajeev, IBM Corp.
+ */
+
+#include <stdio.h>
+#include "../event.h"
+#include "../sampling_tests/misc.h"
+
+/*
+ * Testcase for reserved bits in Monitor Mode
+ * Control Register A (MMCRA) thresh_ctl bits.
+ * For MMCRA[48:51]/[52:55]) Threshold Start/Stop,
+ * 0b11110000/0b00001111 is reserved.
+ */
+
+static int reserved_bits_mmcra_thresh_ctl(void)
+{
+	struct event event;
+
+	/* Check for platform support for the test */
+	SKIP_IF(platform_check_for_tests());
+
+	/* Skip for Generic compat PMU */
+	SKIP_IF(check_for_generic_compat_pmu());
+
+	/*
+	 * MMCRA[48:51]/[52:55]) Threshold Start/Stop
+	 * events Selection. 0b11110000/0b00001111 is reserved.
+	 * Expected to fail when using these reserved values.
+	 */
+	event_init(&event, 0xf0340401e0);
+	FAIL_IF(!event_open(&event));
+
+	event_init(&event, 0x0f340401e0);
+	FAIL_IF(!event_open(&event));
+
+	return 0;
+}
+
+int main(void)
+{
+	return test_harness(reserved_bits_mmcra_thresh_ctl, "reserved_bits_mmcra_thresh_ctl");
+}