selftests/powerpc/pmu: Add selftest for checking valid and invalid bhrb filter maps

For PERF_SAMPLE_BRANCH_STACK sample type, different branch_sample_type,
ie branch filters are supported. All the branch filters are not
supported in powerpc. Example, power10 platform supports any, ind_call
and cond branch filters. Whereas, it is different in power9. Testcase
checks event open for invalid and valid branch sample types. The branch
types for testcase are picked from "perf_branch_sample_type" in
perf_event.h
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/20220610134113.62991-13-atrajeev@linux.vnet.ibm.com

tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile

@@ -6,7 +6,8 @@ TEST_GEN_PROGS := mmcr0_exceptionbits_test mmcr0_cc56run_test mmcr0_pmccext_test
 		   mmcr1_comb_test mmcr2_l2l3_test mmcr2_fcs_fch_test \
 		   mmcr3_src_test mmcra_thresh_marked_sample_test mmcra_thresh_cmp_test \
 		   mmcra_bhrb_ind_call_test mmcra_bhrb_any_test mmcra_bhrb_cond_test \
-		   mmcra_bhrb_disable_test bhrb_no_crash_wo_pmu_test intr_regs_no_crash_wo_pmu_test
+		   mmcra_bhrb_disable_test bhrb_no_crash_wo_pmu_test intr_regs_no_crash_wo_pmu_test \
+		   bhrb_filter_map_test
 
 top_srcdir = ../../../../../..
 include ../../../lib.mk

tools/testing/selftests/powerpc/pmu/sampling_tests/bhrb_filter_map_test.c

+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2022, Athira Rajeev, IBM Corp.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "../event.h"
+#include "misc.h"
+#include "utils.h"
+
+/*
+ * A perf sampling test to check bhrb filter
+ * map. All the branch filters are not supported
+ * in powerpc. Supported filters in:
+ * power10: any, any_call, ind_call, cond
+ * power9: any, any_call
+ *
+ * Testcase checks event open for invalid bhrb filter
+ * types should fail and valid filter types should pass.
+ * Testcase does validity check for these branch
+ * sample types.
+ */
+
+/* Invalid types for powerpc */
+/* Valid bhrb filters in power9/power10 */
+int bhrb_filter_map_valid_common[] = {
+	PERF_SAMPLE_BRANCH_ANY,
+	PERF_SAMPLE_BRANCH_ANY_CALL,
+};
+
+/* Valid bhrb filters in power10 */
+int bhrb_filter_map_valid_p10[] = {
+	PERF_SAMPLE_BRANCH_IND_CALL,
+	PERF_SAMPLE_BRANCH_COND,
+};
+
+#define EventCode 0x1001e
+
+static int bhrb_filter_map_test(void)
+{
+	struct event event;
+	int i;
+
+	/* Check for platform support for the test */
+	SKIP_IF(platform_check_for_tests());
+
+	/*
+	 * Skip for Generic compat PMU since
+	 * bhrb filters is not supported
+	 */
+	SKIP_IF(check_for_generic_compat_pmu());
+
+	/* Init the event for the sampling test */
+	event_init(&event, EventCode);
+
+	event.attr.sample_period = 1000;
+	event.attr.sample_type = PERF_SAMPLE_BRANCH_STACK;
+	event.attr.disabled = 1;
+
+	/* Invalid filter maps which are expected to fail in event_open */
+	for (i = PERF_SAMPLE_BRANCH_USER_SHIFT; i < PERF_SAMPLE_BRANCH_MAX_SHIFT; i++) {
+		/* Skip the valid branch sample type */
+		if (i == PERF_SAMPLE_BRANCH_ANY_SHIFT || i == PERF_SAMPLE_BRANCH_ANY_CALL_SHIFT \
+			|| i == PERF_SAMPLE_BRANCH_IND_CALL_SHIFT || i == PERF_SAMPLE_BRANCH_COND_SHIFT)
+			continue;
+		event.attr.branch_sample_type = 1U << i;
+		FAIL_IF(!event_open(&event));
+	}
+
+	/* valid filter maps for power9/power10 which are expected to pass in event_open */
+	for (i = 0; i < ARRAY_SIZE(bhrb_filter_map_valid_common); i++) {
+		event.attr.branch_sample_type = bhrb_filter_map_valid_common[i];
+		FAIL_IF(event_open(&event));
+		event_close(&event);
+	}
+
+	/*
+	 * filter maps which are valid in power10 and invalid in power9.
+	 * PVR check is used here since PMU specific data like bhrb filter
+	 * alternative tests is handled by respective PMU driver code and
+	 * using PVR will work correctly for all cases including generic
+	 * compat mode.
+	 */
+	if (PVR_VER(mfspr(SPRN_PVR)) == POWER10) {
+		for (i = 0; i < ARRAY_SIZE(bhrb_filter_map_valid_p10); i++) {
+			event.attr.branch_sample_type = bhrb_filter_map_valid_p10[i];
+			FAIL_IF(event_open(&event));
+			event_close(&event);
+		}
+	} else {
+		for (i = 0; i < ARRAY_SIZE(bhrb_filter_map_valid_p10); i++) {
+			event.attr.branch_sample_type = bhrb_filter_map_valid_p10[i];
+			FAIL_IF(!event_open(&event));
+		}
+	}
+
+	return 0;
+}
+
+int main(void)
+{
+	return test_harness(bhrb_filter_map_test, "bhrb_filter_map_test");
+}