[PATCH 18/20] selftest/powerpc/pmu/: Add interface test for mmcr2_fcs_fch fields

[Kajol Jain]

From: Madhavan Srinivasan <maddy at linux.ibm.com>

The testcases uses cycles event to verify the freeze counter
settings in Monitor Mode Control Register 2 (MMCR2). Event
modifier (exclude_kernel) setting is used for the event attribute
to check the FCxS and FCxH ( Freeze counter in privileged and
hypervisor state ) settings via perf interface.

Signed-off-by: Madhavan Srinivasan <maddy at linux.ibm.com>
---
 .../powerpc/pmu/sampling_tests/Makefile       |  6 +-
 .../pmu/sampling_tests/mmcr2_fcs_fch_test.c   | 67 +++++++++++++++++++
 2 files changed, 71 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/powerpc/pmu/sampling_tests/mmcr2_fcs_fch_test.c

diff --git a/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile b/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile
index f01666d7f2e0..1deaab5a4ebf 100644
--- a/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile
+++ b/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile
@@ -3,7 +3,8 @@ include ../../../../../../scripts/Kbuild.include
 
 all: $(TEST_GEN_PROGS) mmcr0_exceptionbits_test.c mmcr0_cc56run_test.c mmcr0_pmccext_test.c \
 			mmcr0_pmcjce_test.c mmcr0_fc56_pmc1ce_test.c mmcr0_fc56_pmc56_test.c \
-			mmcr1_comb_test.c mmcr1_sel_unit_cache_test.c mmcr2_l2l3_test.c
+			mmcr1_comb_test.c mmcr1_sel_unit_cache_test.c mmcr2_l2l3_test.c \
+			mmcr2_fcs_fch_test.c
 
 noarg:
 	$(MAKE) -C ../../
@@ -16,7 +17,8 @@ no-pie-option := $(call try-run, echo 'int main() { return 0; }' | \
 
 TEST_GEN_PROGS := mmcr0_exceptionbits_test mmcr0_cc56run_test mmcr0_pmccext_test \
 		   mmcr0_pmcjce_test mmcr0_fc56_pmc1ce_test mmcr0_fc56_pmc56_test \
-		   mmcr1_comb_test mmcr1_sel_unit_cache_test mmcr2_l2l3_test
+		   mmcr1_comb_test mmcr1_sel_unit_cache_test mmcr2_l2l3_test \
+		   mmcr2_fcs_fch_test
 
 LDFLAGS += $(no-pie-option)
 
diff --git a/tools/testing/selftests/powerpc/pmu/sampling_tests/mmcr2_fcs_fch_test.c b/tools/testing/selftests/powerpc/pmu/sampling_tests/mmcr2_fcs_fch_test.c
new file mode 100644
index 000000000000..1c1c48ca7d4c
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/sampling_tests/mmcr2_fcs_fch_test.c
@@ -0,0 +1,67 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2022, Madhavan Srinivasan, IBM Corp.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "../event.h"
+#include "misc.h"
+#include "utils.h"
+
+extern void thirty_two_instruction_loop(int loops);
+
+/*
+ * A perf sampling test for mmcr2
+ * fields : fcs, fch.
+ */
+static int mmcr2_fcs_fch(void)
+{
+	struct event event;
+	u64 *intr_regs;
+
+	/* Check for platform support for the test */
+	SKIP_IF(check_pvr_for_sampling_tests());
+
+	/* Init the event for the sampling test */
+	event_init_sampling(&event, 0x1001e);
+	event.attr.sample_regs_intr = platform_extended_mask;
+	event.attr.exclude_kernel = 1;
+	FAIL_IF(event_open(&event));
+	event.mmap_buffer = event_sample_buf_mmap(event.fd, 1);
+
+	event_enable(&event);
+
+	/* workload to make the event overflow */
+	thirty_two_instruction_loop(10000);
+
+	event_disable(&event);
+
+	/* Check for sample count */
+	FAIL_IF(!collect_samples(event.mmap_buffer));
+
+	intr_regs = get_intr_regs(&event, event.mmap_buffer);
+
+	/* Check for intr_regs */
+	FAIL_IF(!intr_regs);
+
+	/*
+	 * Verify that fcs and fch field of MMCR2 match
+	 * with corresponding modifier fields.
+	 */
+	if (is_pSeries())
+		FAIL_IF(GET_ATTR_FIELD(&event, exclude_kernel) !=
+			GET_MMCR_FIELD(2, get_reg_value(intr_regs, "MMCR2"), 1, fcs));
+	else
+		FAIL_IF(GET_ATTR_FIELD(&event, exclude_kernel) !=
+			GET_MMCR_FIELD(2, get_reg_value(intr_regs, "MMCR2"), 1, fch));
+
+	event_close(&event);
+	return 0;
+}
+
+int main(void)
+{
+	FAIL_IF(test_harness(mmcr2_fcs_fch, "mmcr2_fcs_fch"));
+}
-- 
2.27.0