[igt-dev] [PATCH i-g-t] tests/perf: Add test to verify non-power-of-2 OA reports

[Umesh Nerlige Ramappa]

Add test to verify perf report size that is not a power of 2. Verify
that the report that spans the boundary of the OA buffer is read
correctly.

v2: (Lionel)
- Call sanity_check_reports to verify report contents.
- Move format definition to the end of the enum to avoid breaking API

Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa at intel.com>
---
 include/drm-uapi/i915_drm.h |   1 +
 tests/perf.c                | 115 ++++++++++++++++++++++++++++++++++++
 2 files changed, 116 insertions(+)

diff --git a/include/drm-uapi/i915_drm.h b/include/drm-uapi/i915_drm.h
index 761517f1..befede6f 100644
--- a/include/drm-uapi/i915_drm.h
+++ b/include/drm-uapi/i915_drm.h
@@ -1834,6 +1834,7 @@ enum drm_i915_oa_format {
 	I915_OA_FORMAT_A12,
 	I915_OA_FORMAT_A12_B8_C8,
 	I915_OA_FORMAT_A32u40_A4u32_B8_C8,
+	I915_OA_FORMAT_A29_B8_C8,
 
 	I915_OA_FORMAT_MAX	    /* non-ABI */
 };
diff --git a/tests/perf.c b/tests/perf.c
index 5ad8b2db..00c81b6d 100644
--- a/tests/perf.c
+++ b/tests/perf.c
@@ -136,6 +136,11 @@ static struct oa_format hsw_oa_formats[I915_OA_FORMAT_MAX] = {
 		"C4_B8", .size = 64,
 		.c_off = 16, .n_c = 4,
 		.b_off = 28, .n_b = 8 },
+	[I915_OA_FORMAT_A29_B8_C8] = { /* HSW only */
+		"A29_B8_C8", .size = 192,
+		.a_off = 12,  .n_a = 29,
+		.b_off = 128, .n_b = 8,
+		.c_off = 160, .n_c = 8, },
 };
 
 static struct oa_format gen8_oa_formats[I915_OA_FORMAT_MAX] = {
@@ -1191,6 +1196,70 @@ test_missing_sample_flags(void)
 	do_ioctl_err(drm_fd, DRM_IOCTL_I915_PERF_OPEN, &param, EINVAL);
 }
 
+static void
+read_oa_reports(int format_id,
+		int exponent,
+		int max_reports)
+{
+	size_t format_size = get_oa_format(format_id).size;
+	size_t sample_size = (sizeof(struct drm_i915_perf_record_header) +
+			      format_size);
+	const struct drm_i915_perf_record_header *header;
+	uint32_t exponent_mask = (1 << (exponent + 1)) - 1;
+
+	/* Allocate twice max buffer size to verify odd report size support and
+	 * wrap around
+	 */
+	int buf_size = sample_size * max_reports * 1.5;
+	uint8_t *buf = malloc(buf_size);
+	uint8_t *rbuf = buf;
+	int num_reports = 0;
+	uint32_t *oa_report0;
+	ssize_t len = 0;
+
+	while (num_reports < max_reports) {
+		buf += len;
+		while ((len = read(stream_fd, buf, buf_size)) < 0 &&
+		       errno == EINTR)
+			;
+
+		igt_assert(len > 0);
+		igt_debug("read %d bytes\n", (int)len);
+
+		for (size_t offset = 0; (offset < len) && (num_reports < max_reports); offset += header->size) {
+			uint32_t *oa_report1;
+
+			header = (void *)(buf + offset);
+			igt_debug("header = %p\n", header);
+
+			igt_assert_eq(header->pad, 0);
+			igt_assert_neq(header->type, DRM_I915_PERF_RECORD_OA_BUFFER_LOST);
+			if (header->type == DRM_I915_PERF_RECORD_OA_REPORT_LOST) {
+				igt_debug("read restart: OA trigger collision / report lost\n");
+				num_reports = 0;
+				break;
+			}
+
+			igt_assert_eq(header->type, DRM_I915_PERF_RECORD_SAMPLE);
+			igt_assert_eq(header->size, sample_size);
+			oa_report1 = (void *)(header + 1);
+			igt_debug("read report: reason = %x, timestamp = %x, exponent mask=%x\n",
+				  oa_report1[0], oa_report1[1], exponent_mask);
+			igt_assert_neq(oa_report1[1], 0);
+
+			num_reports++;
+			if (num_reports >= 2) {
+				sanity_check_reports(oa_report0, oa_report1,
+						     format_id);
+			}
+			oa_report0 = oa_report1;
+		}
+	}
+
+	igt_debug("num_reports %d\n", num_reports);
+	free(rbuf);
+}
+
 static void
 read_2_oa_reports(int format_id,
 		  int exponent,
@@ -1304,6 +1373,34 @@ read_2_oa_reports(int format_id,
 	igt_assert(!"reached");
 }
 
+static void
+open_and_read_oa_reports(int format_id,
+			 int exponent,
+			 int num_reports)
+{
+	uint64_t properties[] = {
+		/* Include OA reports in samples */
+		DRM_I915_PERF_PROP_SAMPLE_OA, true,
+
+		/* OA unit configuration */
+		DRM_I915_PERF_PROP_OA_METRICS_SET, test_metric_set_id,
+		DRM_I915_PERF_PROP_OA_FORMAT, format_id,
+		DRM_I915_PERF_PROP_OA_EXPONENT, exponent,
+
+	};
+	struct drm_i915_perf_open_param param = {
+		.flags = I915_PERF_FLAG_FD_CLOEXEC,
+		.num_properties = sizeof(properties) / 16,
+		.properties_ptr = to_user_pointer(properties),
+	};
+
+	stream_fd = __perf_open(drm_fd, &param, false);
+
+	read_oa_reports(format_id, exponent, num_reports);
+
+	__perf_close(stream_fd);
+}
+
 static void
 open_and_read_2_oa_reports(int format_id,
 			   int exponent,
@@ -1493,6 +1590,19 @@ print_report(uint32_t *report, int fmt)
 }
 #endif
 
+static void
+test_non_power_of_2_oa_formats(void)
+{
+	struct oa_format format = get_oa_format(I915_OA_FORMAT_A29_B8_C8);
+	int num_reports = ((MAX_OA_BUF_SIZE / format.size) << 1) + 100;
+
+	igt_assert(format.name);
+	igt_debug("Reading %d reports for OA format %s\n", num_reports, format.name);
+	open_and_read_oa_reports(I915_OA_FORMAT_A29_B8_C8,
+				 oa_exp_1_millisec,
+				 num_reports);
+}
+
 static void
 test_oa_formats(void)
 {
@@ -4124,6 +4234,11 @@ igt_main
 	igt_subtest("oa-formats")
 		test_oa_formats();
 
+	igt_subtest("non-power-of-2-oa-formats") {
+		igt_require(IS_HASWELL(devid));
+		test_non_power_of_2_oa_formats();
+	}
+
 	igt_subtest("invalid-oa-exponent")
 		test_invalid_oa_exponent();
 	igt_subtest("low-oa-exponent-permissions")
-- 
2.20.1