selftests/powerpc/pmu: Add selftest for checking invalid bits in event code

Some of the bits in the event code is reserved for specific platforms.
Event code bits 52-59 are reserved in power9, whereas in power10, these
are used for programming Monitor Mode Control Register 3 (MMCR3). Bit 9
in event code is reserved in power9, whereas it is used for programming
"radix_scope_qual" bit 18 in Monitor Mode Control Register 1 (MMCR1).

Testcase to ensure that using reserved bits in event code should cause
event_open to fail.

Signed-off-by: Athira Rajeev <[e-mail]>
Signed-off-by: Michael Ellerman <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

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

···
 
 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
+	group_constraint_mmcra_sample_test invalid_event_code_test
 
 top_srcdir = ../../../../../..
 include ../../../lib.mk

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

···
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2022, Athira Rajeev, IBM Corp.
+ */
+
+#include <stdio.h>
+#include <sys/prctl.h>
+#include <limits.h>
+#include "../event.h"
+#include "../sampling_tests/misc.h"
+
+/* The data cache was reloaded from local core's L3 due to a demand load */
+#define EventCode_1 0x1340000001c040
+/* PM_DATA_RADIX_PROCESS_L2_PTE_FROM_L2 */
+#define EventCode_2 0x14242
+/* Event code with IFM, EBB, BHRB bits set in event code */
+#define EventCode_3 0xf00000000000001e
+
+/*
+ * Some of the bits in the event code is
+ * reserved for specific platforms.
+ * Event code bits 52-59 are reserved in power9,
+ * whereas in power10, these are used for programming
+ * Monitor Mode Control Register 3 (MMCR3).
+ * Bit 9 in event code is reserved in power9,
+ * whereas it is used for programming "radix_scope_qual"
+ * bit 18 in Monitor Mode Control Register 1 (MMCR1).
+ *
+ * Testcase to ensure that using reserved bits in
+ * event code should cause event_open to fail.
+ */
+
+static int invalid_event_code(void)
+{
+	struct event event;
+
+	/* Check for platform support for the test */
+	SKIP_IF(platform_check_for_tests());
+
+	/*
+	 * Events using MMCR3 bits and radix scope qual bits
+	 * should fail in power9 and should succeed in power10.
+	 * Init the events and check for pass/fail in event open.
+	 */
+	if (have_hwcap2(PPC_FEATURE2_ARCH_3_1)) {
+		event_init(&event, EventCode_1);
+		FAIL_IF(event_open(&event));
+		event_close(&event);
+
+		event_init(&event, EventCode_2);
+		FAIL_IF(event_open(&event));
+		event_close(&event);
+	} else {
+		event_init(&event, EventCode_1);
+		FAIL_IF(!event_open(&event));
+
+		event_init(&event, EventCode_2);
+		FAIL_IF(!event_open(&event));
+	}
+
+	return 0;
+}
+
+int main(void)
+{
+	return test_harness(invalid_event_code, "invalid_event_code");
+}