[PATCH 20/20] selftest/powerpc/pmu: Add interface test for mmcra register fields

[Kajol Jain]

The testcase uses event code 0x35340401e0 to verify
the settings for different fields in Monitor Mode Control
Register A (MMCRA). The fields include thresh_start, thresh_stop
thresh_select, sdar mode, sample and marked bit. Checks if
these fields are translated correctly via perf interface to MMCRA.

Signed-off-by: Kajol Jain <kjain at linux.ibm.com>
---
 .../powerpc/pmu/sampling_tests/Makefile       |  4 +-
 .../mmcra_thresh_marked_sample_test.c         | 80 +++++++++++++++++++
 2 files changed, 82 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/powerpc/pmu/sampling_tests/mmcra_thresh_marked_sample_test.c

diff --git a/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile b/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile
index 58d3ddf779d2..a9bf343df911 100644
--- a/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile
+++ b/tools/testing/selftests/powerpc/pmu/sampling_tests/Makefile
@@ -4,7 +4,7 @@ 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 \
-			mmcr2_fcs_fch_test.c mmcr3_src_test.c
+			mmcr2_fcs_fch_test.c mmcr3_src_test.c mmcra_thresh_marked_sample_test.c
 
 noarg:
 	$(MAKE) -C ../../
@@ -18,7 +18,7 @@ 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 \
-		   mmcr2_fcs_fch_test mmcr3_src_test
+		   mmcr2_fcs_fch_test mmcr3_src_test mmcra_thresh_marked_sample_test
 
 LDFLAGS += $(no-pie-option)
 
diff --git a/tools/testing/selftests/powerpc/pmu/sampling_tests/mmcra_thresh_marked_sample_test.c b/tools/testing/selftests/powerpc/pmu/sampling_tests/mmcra_thresh_marked_sample_test.c
new file mode 100644
index 000000000000..ca6bdb335fa5
--- /dev/null
+++ b/tools/testing/selftests/powerpc/pmu/sampling_tests/mmcra_thresh_marked_sample_test.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2022, Kajol Jain, IBM Corp.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "../event.h"
+#include "misc.h"
+#include "utils.h"
+
+/*
+ * Primary PMU event used here is PM_MRK_INST_CMPL (0x401e0)
+ * Threshold event selection used is issue to complete for cycles
+ * Sampling criteria is Load only sampling
+ */
+#define EventCode 0x35340401e0
+
+extern void thirty_two_instruction_loop_with_ll_sc(u64 loops, u64 *ll_sc_target);
+
+/* A perf sampling test to test mmcra fields */
+static int mmcra_thresh_marked_sample(void)
+{
+	struct event event;
+	u64 *intr_regs;
+	u64 dummy;
+
+	/* 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, EventCode);
+	event.attr.sample_regs_intr = platform_extended_mask;
+	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_with_ll_sc(1000000, &dummy);
+
+	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 thresh sel/start/stop, marked, random sample
+	 * eligibility, sdar mode and sample mode fields match with
+	 * the corresponding event code fields
+	 */
+	FAIL_IF(EV_CODE_EXTRACT(event.attr.config, thd_sel) !=
+			GET_MMCR_FIELD(A, get_reg_value(intr_regs, "MMCRA"), 4, thd_sel));
+	FAIL_IF(EV_CODE_EXTRACT(event.attr.config, thd_start) !=
+			GET_MMCR_FIELD(A, get_reg_value(intr_regs, "MMCRA"), 4, thd_start));
+	FAIL_IF(EV_CODE_EXTRACT(event.attr.config, thd_stop) !=
+			GET_MMCR_FIELD(A, get_reg_value(intr_regs, "MMCRA"), 4, thd_stop));
+	FAIL_IF(EV_CODE_EXTRACT(event.attr.config, marked) !=
+			GET_MMCR_FIELD(A, get_reg_value(intr_regs, "MMCRA"), 4, marked));
+	FAIL_IF(EV_CODE_EXTRACT(event.attr.config, sample >> 2) !=
+			GET_MMCR_FIELD(A, get_reg_value(intr_regs, "MMCRA"), 4, rand_samp_elig));
+	FAIL_IF(EV_CODE_EXTRACT(event.attr.config, sample & 0x3) !=
+			GET_MMCR_FIELD(A, get_reg_value(intr_regs, "MMCRA"), 4, sample_mode));
+	FAIL_IF(EV_CODE_EXTRACT(event.attr.config, sm) !=
+			GET_MMCR_FIELD(A, get_reg_value(intr_regs, "MMCRA"), 4, sm));
+
+	event_close(&event);
+	return 0;
+}
+
+int main(void)
+{
+	FAIL_IF(test_harness(mmcra_thresh_marked_sample, "mmcra_thresh_marked_sample"));
+}
-- 
2.27.0