[igt-dev] [PATCH 19/29] lib/i915/perf: store bit shifting required for OA timestamps

[Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>]

From: Lionel Landwerlin <lionel.g.landwerlin@intel.com>

Some new platforms have the OA timestamps shifted to the right by a
number of bits. This is configurable but since i915 appears to leave
the default values, let's just hardcode this in the device info.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
---
 lib/i915/perf.c                    | 31 +++++++++++++++++++++++++-----
 lib/i915/perf.h                    | 18 ++++++++++++++++-
 lib/i915/perf_data_reader.c        |  2 +-
 lib/meson.build                    |  4 ++--
 tools/i915-perf/i915_perf_reader.c |  3 ++-
 5 files changed, 48 insertions(+), 10 deletions(-)

diff --git a/lib/i915/perf.c b/lib/i915/perf.c
index f7aff13a..4c1b75ad 100644
--- a/lib/i915/perf.c
+++ b/lib/i915/perf.c
@@ -299,6 +299,10 @@ intel_perf_for_devinfo(uint32_t device_id,
 	/* Valid on most generations except Gen9LP. */
 	perf->devinfo.eu_threads_count = 7;
 
+	/* Most platforms have full 32bit timestamps. */
+	perf->devinfo.oa_timestamp_mask = 0xffffffff;
+	perf->devinfo.oa_timestamp_shift = 0;
+
 	if (devinfo->is_haswell) {
 		intel_perf_load_metrics_hsw(perf);
 	} else if (devinfo->is_broadwell) {
@@ -765,7 +769,8 @@ accumulate_uint40(int a_index,
 }
 
 void intel_perf_accumulate_reports(struct intel_perf_accumulator *acc,
-				   int oa_format,
+				   const struct intel_perf *perf,
+				   const struct intel_perf_metric_set *metric_set,
 				   const struct drm_i915_perf_record_header *record0,
 				   const struct drm_i915_perf_record_header *record1)
 {
@@ -777,9 +782,13 @@ void intel_perf_accumulate_reports(struct intel_perf_accumulator *acc,
 
 	memset(acc, 0, sizeof(*acc));
 
-	switch (oa_format) {
+	switch (metric_set->perf_oa_format) {
 	case I915_OA_FORMAT_A24u40_A14u32_B8_C8:
-		accumulate_uint32(start + 1, end + 1, deltas + idx++); /* timestamp */
+		/* timestamp */
+		if (perf->devinfo.oa_timestamp_shift >= 0)
+			deltas[idx++] += (end[1] - start[1]) << perf->devinfo.oa_timestamp_shift;
+		else
+			deltas[idx++] += (end[1] - start[1]) >> (-perf->devinfo.oa_timestamp_shift);
 		accumulate_uint32(start + 3, end + 3, deltas + idx++); /* clock */
 
 		/* 4x 32bit A0-3 counters... */
@@ -812,7 +821,10 @@ void intel_perf_accumulate_reports(struct intel_perf_accumulator *acc,
 
 	case I915_OAR_FORMAT_A32u40_A4u32_B8_C8:
 	case I915_OA_FORMAT_A32u40_A4u32_B8_C8:
-		accumulate_uint32(start + 1, end + 1, deltas + idx++); /* timestamp */
+		if (perf->devinfo.oa_timestamp_shift >= 0)
+			deltas[idx++] += (end[1] - start[1]) << perf->devinfo.oa_timestamp_shift;
+		else
+			deltas[idx++] += (end[1] - start[1]) >> (-perf->devinfo.oa_timestamp_shift);
 		accumulate_uint32(start + 3, end + 3, deltas + idx++); /* clock */
 
 		/* 32x 40bit A counters... */
@@ -829,7 +841,11 @@ void intel_perf_accumulate_reports(struct intel_perf_accumulator *acc,
 		break;
 
 	case I915_OA_FORMAT_A45_B8_C8:
-		accumulate_uint32(start + 1, end + 1, deltas); /* timestamp */
+		/* timestamp */
+		if (perf->devinfo.oa_timestamp_shift >= 0)
+			deltas[0] += (end[1] - start[1]) << perf->devinfo.oa_timestamp_shift;
+		else
+			deltas[0] += (end[1] - start[1]) >> (-perf->devinfo.oa_timestamp_shift);
 
 		for (i = 0; i < 61; i++)
 			accumulate_uint32(start + 3 + i, end + 3 + i, deltas + 1 + i);
@@ -858,5 +874,10 @@ uint64_t intel_perf_read_record_timestamp(const struct intel_perf *perf,
                assert(0);
        }
 
+       if (perf->devinfo.oa_timestamp_shift >= 0)
+	       ts <<= perf->devinfo.oa_timestamp_shift;
+       else
+	       ts >>= -perf->devinfo.oa_timestamp_shift;
+
        return ts;
 }
diff --git a/lib/i915/perf.h b/lib/i915/perf.h
index 88a36ebe..a0dba342 100644
--- a/lib/i915/perf.h
+++ b/lib/i915/perf.h
@@ -56,6 +56,21 @@ struct intel_perf_devinfo {
 	uint32_t devid;
 	uint32_t graphics_ver;
 	uint32_t revision;
+	/**
+	 * Bit shifting required to put OA report timestamps into
+	 * timestamp_frequency (some HW generations can shift
+	 * timestamp values to the right by a number of bits).
+	 */
+	int32_t  oa_timestamp_shift;
+	/**
+	 * On some platforms only part of the timestamp bits are valid
+	 * (on previous platforms we would get full 32bits, newer
+	 * platforms can have fewer). It's important to know when
+	 * correlating the full 36bits timestamps to the OA report
+	 * timestamps.
+	 */
+	uint64_t  oa_timestamp_mask;
+	/* Frequency of the timestamps in Hz */
 	uint64_t timestamp_frequency;
 	uint64_t gt_min_freq;
 	uint64_t gt_max_freq;
@@ -320,7 +335,8 @@ void intel_perf_add_metric_set(struct intel_perf *perf,
 void intel_perf_load_perf_configs(struct intel_perf *perf, int drm_fd);
 
 void intel_perf_accumulate_reports(struct intel_perf_accumulator *acc,
-				   int oa_format,
+				   const struct intel_perf *perf,
+				   const struct intel_perf_metric_set *metric_set,
 				   const struct drm_i915_perf_record_header *record0,
 				   const struct drm_i915_perf_record_header *record1);
 
diff --git a/lib/i915/perf_data_reader.c b/lib/i915/perf_data_reader.c
index 4d1efe92..fcdd5ed1 100644
--- a/lib/i915/perf_data_reader.c
+++ b/lib/i915/perf_data_reader.c
@@ -209,7 +209,7 @@ correlate_gpu_timestamp(struct intel_perf_data_reader *reader,
 	 * Try to figure what portion of the correlation data the
 	 * 32bit timestamp belongs to.
 	 */
-	uint64_t mask = 0xffffffff;
+	uint64_t mask = reader->perf->devinfo.oa_timestamp_mask;
 	int corr_idx = -1;
 
 	for (uint32_t i = 0; i < reader->n_correlation_chunks; i++) {
diff --git a/lib/meson.build b/lib/meson.build
index 747889b9..6b5b9e04 100644
--- a/lib/meson.build
+++ b/lib/meson.build
@@ -321,7 +321,7 @@ lib_igt_i915_perf_build = shared_library(
   dependencies: lib_igt_chipset,
   include_directories : inc,
   install: true,
-  soversion: '1.4')
+  soversion: '1.5')
 
 lib_igt_i915_perf = declare_dependency(
   link_with : lib_igt_i915_perf_build,
@@ -342,7 +342,7 @@ pkgconf.set('prefix', get_option('prefix'))
 pkgconf.set('exec_prefix', '${prefix}')
 pkgconf.set('libdir', '${prefix}/@0@'.format(get_option('libdir')))
 pkgconf.set('includedir', '${prefix}/@0@'.format(get_option('includedir')))
-pkgconf.set('i915_perf_version', '1.4.0')
+pkgconf.set('i915_perf_version', '1.5.0')
 
 configure_file(
   input : 'i915-perf.pc.in',
diff --git a/tools/i915-perf/i915_perf_reader.c b/tools/i915-perf/i915_perf_reader.c
index afd8c39c..4a2e3df4 100644
--- a/tools/i915-perf/i915_perf_reader.c
+++ b/tools/i915-perf/i915_perf_reader.c
@@ -271,7 +271,8 @@ main(int argc, char *argv[])
 		fprintf(stdout, "hw_id=0x%x %s\n",
 			item->hw_id, item->hw_id == 0xffffffff ? "(idle)" : "");
 
-		intel_perf_accumulate_reports(&accu, reader.metric_set->perf_oa_format,
+		intel_perf_accumulate_reports(&accu,
+					      reader.perf, reader.metric_set,
 					      i915_report0, i915_report1);
 
 		for (uint32_t c = 0; c < n_counters; c++) {
-- 
2.25.1