tools/perf/arch/x86/util/topdown.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include "api/fs/fs.h"
   3 #include "util/evsel.h"
   4 #include "util/evlist.h"
   5 #include "util/pmu.h"
   6 #include "util/pmus.h"
   7 #include "util/topdown.h"
   8 #include "topdown.h"
   9 #include "evsel.h"
  10
  11 /* Check whether there is a PMU which supports the perf metrics. */
  12 bool topdown_sys_has_perf_metrics(void)
  13 {
  14         static bool has_perf_metrics;
  15         static bool cached;
  16         struct perf_pmu *pmu;
  17
  18         if (cached)
  19                 return has_perf_metrics;
  20
  21         /*
  22          * The perf metrics feature is a core PMU feature.
  23          * The PERF_TYPE_RAW type is the type of a core PMU.
  24          * The slots event is only available when the core PMU
  25          * supports the perf metrics feature.
  26          */
  27         pmu = perf_pmus__find_by_type(PERF_TYPE_RAW);
  28         if (pmu && perf_pmu__have_event(pmu, "slots"))
  29                 has_perf_metrics = true;
  30
  31         cached = true;
  32         return has_perf_metrics;
  33 }
  34
  35 #define TOPDOWN_SLOTS           0x0400
  36 bool arch_is_topdown_slots(const struct evsel *evsel)
  37 {
  38         if (evsel->core.attr.config == TOPDOWN_SLOTS)
  39                 return true;
  40
  41         return false;
  42 }
  43
  44 bool arch_is_topdown_metrics(const struct evsel *evsel)
  45 {
  46         int config = evsel->core.attr.config;
  47         const char *name_from_config;
  48         struct perf_pmu *pmu;
  49
  50         /* All topdown events have an event code of 0. */
  51         if ((config & 0xFF) != 0)
  52                 return false;
  53
  54         pmu = evsel__find_pmu(evsel);
  55         if (!pmu || !pmu->is_core)
  56                 return false;
  57
  58         name_from_config = perf_pmu__name_from_config(pmu, config);
  59         return name_from_config && strcasestr(name_from_config, "topdown");
  60 }
  61
  62 /*
  63  * Check whether a topdown group supports sample-read.
  64  *
  65  * Only Topdown metric supports sample-read. The slots
  66  * event must be the leader of the topdown group.
  67  */
  68 bool arch_topdown_sample_read(struct evsel *leader)
  69 {
  70         struct evsel *evsel;
  71
  72         if (!evsel__sys_has_perf_metrics(leader))
  73                 return false;
  74
  75         if (!arch_is_topdown_slots(leader))
  76                 return false;
  77
  78         /*
  79          * If slots event as leader event but no topdown metric events
  80          * in group, slots event should still sample as leader.
  81          */
  82         evlist__for_each_entry(leader->evlist, evsel) {
  83                 if (evsel->core.leader != leader->core.leader)
  84                         return false;
  85                 if (evsel != leader && arch_is_topdown_metrics(evsel))
  86                         return true;
  87         }
  88
  89         return false;
  90 }