intel_pps_driver.h revision 7ec681f3 
1/*
2 * Copyright © 2020-2021 Collabora, Ltd.
3 * Author: Antonio Caggiano <antonio.caggiano@collabora.com>
4 *
5 * SPDX-License-Identifier: MIT
6 */
7
8#pragma once
9
10#include <pps/pps_driver.h>
11
12#include "intel_pps_perf.h"
13
14namespace pps
15{
16/// Timestamp correlation between CPU/GPU.
17struct TimestampCorrelation {
18   /// In CLOCK_MONOTONIC
19   uint64_t cpu_timestamp;
20
21   /// Engine timestamp associated with the OA unit
22   uint64_t gpu_timestamp;
23};
24
25/// @brief Variable length sequence of bytes generated by Intel Obstervation Architecture (OA)
26using PerfRecord = std::vector<uint8_t>;
27
28/// @brief PPS Driver implementation for Intel graphics devices.
29/// When sampling it may collect multiple perf-records at once. Each perf-record holds multiple
30/// counter values. Those values are continuously incremented by the GPU. In order to get a delta,
31/// the driver computes an _accumulation_ (`last_perf_record - previous_perf_record`).
32/// For optimization purposes, it might ignore some perf-records, considering only those
33/// perf-records close to the boundary of the sampling period range.
34class IntelDriver : public Driver
35{
36   public:
37   std::optional<TimestampCorrelation> query_correlation_timestamps() const;
38   void get_new_correlation();
39
40   /// @brief OA reports only have the lower 32 bits of the timestamp
41   /// register, while correlation data has the whole 36 bits.
42   /// @param gpu_ts a 32 bit OA report GPU timestamp
43   /// @return The CPU timestamp relative to the argument
44   uint64_t correlate_gpu_timestamp(uint32_t gpu_ts);
45
46   uint64_t get_min_sampling_period_ns() override;
47   bool init_perfcnt() override;
48   void enable_counter(uint32_t counter_id) override;
49   void enable_all_counters() override;
50   void enable_perfcnt(uint64_t sampling_period_ns) override;
51   void disable_perfcnt() override;
52   bool dump_perfcnt() override;
53   uint64_t next() override;
54
55   /// @brief Requests the next perf sample
56   /// @return The sample GPU timestamp
57   uint32_t gpu_next();
58
59   /// @brief Requests the next perf sample accumulating those which
60   /// which duration is shorter than the requested sampling period
61   /// @return The sample CPU timestamp
62   uint64_t cpu_next();
63
64   /// @param data Buffer of bytes to parse
65   /// @param byte_count Number of bytes to parse
66   /// @return A list of perf records parsed from raw data passed as input
67   std::vector<PerfRecord> parse_perf_records(const std::vector<uint8_t> &data, size_t byte_count);
68
69   /// @brief Reads data from the GPU metric set
70   void read_data_from_metric_set();
71
72   /// Sampling period in nanoseconds requested by the datasource
73   uint64_t sampling_period_ns = 0;
74
75   /// Keep track of the timestamp of the last sample generated
76   uint64_t last_cpu_timestamp = 0;
77
78   /// This is used to correlate CPU and GPU timestamps
79   std::array<TimestampCorrelation, 64> correlations;
80
81   /// Data buffer used to store data read from the metric set
82   std::vector<uint8_t> metric_buffer = std::vector<uint8_t>(1024, 0);
83   /// Number of bytes read so far still un-parsed.
84   /// Reset once bytes from the metric buffer are parsed to perf records
85   size_t total_bytes_read = 0;
86
87   /// List of OA perf records read so far
88   std::vector<PerfRecord> records;
89
90   std::unique_ptr<IntelPerf> perf;
91
92   // Accumulations are stored here
93   struct intel_perf_query_result result = {};
94};
95
96} // namespace pps
97