[igt-dev] [PATCH i-g-t] test/perf: Add test to verify OA TLB invalidation

[Umesh Nerlige Ramappa]

Run 2 blocking tests back to back and compare the number of OA reports
captured. Make sure the number of reports are within an acceptable range
of the expected number of reports.

v2: Drop poll and use blocking IO (Lionel)
v3: Verify number of expected reports for both tests (Lionel)

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
---
 tests/perf.c | 92 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)

diff --git a/tests/perf.c b/tests/perf.c
index 5e818030..b757e307 100644
--- a/tests/perf.c
+++ b/tests/perf.c
@@ -2265,6 +2265,92 @@ test_polling(void)
 	__perf_close(stream_fd);
 }
 
+static int
+num_valid_reports_captured(struct drm_i915_perf_open_param *param,
+			   int64_t *duration_ns)
+{
+	uint8_t buf[1024 * 1024];
+	int64_t start, end;
+	int num_reports = 0;
+
+	igt_debug("Expected duration = %lu\n", *duration_ns);
+
+	stream_fd = __perf_open(drm_fd, param, true);
+
+	start = get_time();
+	do_ioctl(stream_fd, I915_PERF_IOCTL_ENABLE, 0);
+	for (/* nop */; ((end = get_time()) - start) < *duration_ns; /* nop */) {
+		struct drm_i915_perf_record_header *header;
+		int ret;
+
+		while ((ret = read(stream_fd, buf, sizeof(buf))) < 0 &&
+		       errno == EINTR)
+			;
+
+		igt_assert(ret > 0);
+
+		for (int offset = 0; offset < ret; offset += header->size) {
+			header = (void *)(buf + offset);
+
+			if (header->type == DRM_I915_PERF_RECORD_SAMPLE) {
+				uint32_t *report = (void *)(header + 1);
+
+				if ((report[0] >> OAREPORT_REASON_SHIFT) &
+				    OAREPORT_REASON_TIMER)
+					num_reports++;
+			}
+		}
+	}
+	__perf_close(stream_fd);
+
+	*duration_ns = end - start;
+
+	igt_debug("Actual duration = %lu\n", *duration_ns);
+
+	return num_reports;
+}
+
+static void
+gen12_test_oa_tlb_invalidate(void)
+{
+	int oa_exponent = max_oa_exponent_for_period_lte(30000000);
+	uint64_t properties[] = {
+		DRM_I915_PERF_PROP_SAMPLE_OA, true,
+
+		DRM_I915_PERF_PROP_OA_METRICS_SET, test_set->perf_oa_metrics_set,
+		DRM_I915_PERF_PROP_OA_FORMAT, test_set->perf_oa_format,
+		DRM_I915_PERF_PROP_OA_EXPONENT, oa_exponent,
+	};
+	struct drm_i915_perf_open_param param = {
+		.flags = I915_PERF_FLAG_FD_CLOEXEC |
+			I915_PERF_FLAG_DISABLED,
+		.num_properties = sizeof(properties) / 16,
+		.properties_ptr = to_user_pointer(properties),
+	};
+	int num_reports1, num_reports2, num_expected_reports;
+	int64_t duration;
+	
+	/* Capture reports for 5 seconds twice and then make sure you get around
+	 * the same number of reports. In the case of failure, the number of
+	 * reports will vary largely since the beginning of the OA buffer
+	 * will have invalid entries.
+	 */
+	duration = 5LL * NSEC_PER_SEC;
+	num_reports1 = num_valid_reports_captured(&param, &duration);
+	num_expected_reports = duration / oa_exponent_to_ns(oa_exponent);
+	igt_debug("expected num reports = %d\n", num_expected_reports);
+	igt_debug("actual num reports = %d\n", num_reports1);
+	igt_assert(num_reports1 > 0.95 * num_expected_reports);
+
+	duration = 5LL * NSEC_PER_SEC;
+	num_reports2 = num_valid_reports_captured(&param, &duration);
+	num_expected_reports = duration / oa_exponent_to_ns(oa_exponent);
+	igt_debug("expected num reports = %d\n", num_expected_reports);
+	igt_debug("actual num reports = %d\n", num_reports2);
+	igt_assert(num_reports2 > 0.95 * num_expected_reports);
+}
+
+
 static void
 test_buffer_fill(void)
 {
@@ -4622,6 +4708,12 @@ igt_main
 		gen8_test_single_ctx_render_target_writes_a_counter();
 	}
 
+	igt_describe("Test OA TLB invalidate");
+	igt_subtest("gen12-oa-tlb-invalidate") {
+		igt_require(intel_gen(devid) >= 12);
+		gen12_test_oa_tlb_invalidate();
+	}
+
 	igt_describe("Measure performance for a specific context using OAR in Gen 12");
 	igt_subtest("gen12-unprivileged-single-ctx-counters") {
 		igt_require(intel_gen(devid) >= 12);
-- 
2.17.1