xref: /linux/tools/perf/arch/x86/util/topdown.c (revision 9e906a9dead17d81d6c2687f65e159231d0e3286)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <errno.h>
3 #include "util/evlist.h"
4 #include "util/pmu.h"
5 #include "util/pmus.h"
6 #include "util/topdown.h"
7 #include "topdown.h"
8 #include "evsel.h"
9 
10 // cmask=0, inv=0, pc=0, edge=0, umask=4, event=0
11 #define TOPDOWN_SLOTS		0x0400
12 
13 /* Check whether there is a PMU which supports the perf metrics. */
topdown_sys_has_perf_metrics(void)14 bool topdown_sys_has_perf_metrics(void)
15 {
16 	static bool has_perf_metrics;
17 	static bool cached;
18 	struct perf_pmu *pmu;
19 
20 	if (cached)
21 		return has_perf_metrics;
22 
23 	/*
24 	 * The perf metrics feature is a core PMU feature.
25 	 * The PERF_TYPE_RAW type is the type of a core PMU.
26 	 * The slots event is only available when the core PMU
27 	 * supports the perf metrics feature.
28 	 */
29 	pmu = perf_pmus__find_by_type(PERF_TYPE_RAW);
30 	if (pmu && perf_pmu__have_event(pmu, "slots"))
31 		has_perf_metrics = true;
32 
33 	cached = true;
34 	return has_perf_metrics;
35 }
36 
arch_is_topdown_slots(const struct evsel * evsel)37 bool arch_is_topdown_slots(const struct evsel *evsel)
38 {
39 	return evsel->core.attr.type == PERF_TYPE_RAW &&
40 	       evsel->core.attr.config == TOPDOWN_SLOTS &&
41 	       evsel->core.attr.config1 == 0;
42 }
43 
arch_is_topdown_metrics(const struct evsel * evsel)44 bool arch_is_topdown_metrics(const struct evsel *evsel)
45 {
46 	// cmask=0, inv=0, pc=0, edge=0, umask=0x80-0x87, event=0
47 	return evsel->core.attr.type == PERF_TYPE_RAW &&
48 		(evsel->core.attr.config & 0xFFFFF8FF) == 0x8000 &&
49 		evsel->core.attr.config1 == 0;
50 }
51 
52 /*
53  * Check whether a topdown group supports sample-read.
54  *
55  * Only Topdown metric supports sample-read. The slots
56  * event must be the leader of the topdown group.
57  */
arch_topdown_sample_read(struct evsel * leader)58 bool arch_topdown_sample_read(struct evsel *leader)
59 {
60 	struct evsel *evsel;
61 
62 	if (!evsel__sys_has_perf_metrics(leader))
63 		return false;
64 
65 	if (!arch_is_topdown_slots(leader))
66 		return false;
67 
68 	/*
69 	 * If slots event as leader event but no topdown metric events
70 	 * in group, slots event should still sample as leader.
71 	 */
72 	evlist__for_each_entry(leader->evlist, evsel) {
73 		if (evsel->core.leader != leader->core.leader)
74 			continue;
75 		if (evsel != leader && arch_is_topdown_metrics(evsel))
76 			return true;
77 	}
78 
79 	return false;
80 }
81 
82 /*
83  * Make a copy of the topdown metric event metric_event with the given index but
84  * change its configuration to be a topdown slots event. Copying from
85  * metric_event ensures modifiers are the same.
86  */
topdown_insert_slots_event(struct list_head * list,int idx,struct evsel * metric_event)87 int topdown_insert_slots_event(struct list_head *list, int idx, struct evsel *metric_event)
88 {
89 	struct evsel *evsel = evsel__new_idx(&metric_event->core.attr, idx);
90 
91 	if (!evsel)
92 		return -ENOMEM;
93 
94 	evsel->core.attr.config = TOPDOWN_SLOTS;
95 	evsel->core.cpus = perf_cpu_map__get(metric_event->core.cpus);
96 	evsel->core.pmu_cpus = perf_cpu_map__get(metric_event->core.pmu_cpus);
97 	evsel->core.is_pmu_core = true;
98 	evsel->pmu = metric_event->pmu;
99 	evsel->name = strdup("slots");
100 	evsel->precise_max = metric_event->precise_max;
101 	evsel->sample_read = metric_event->sample_read;
102 	evsel->weak_group = metric_event->weak_group;
103 	evsel->bpf_counter = metric_event->bpf_counter;
104 	evsel->retire_lat = metric_event->retire_lat;
105 	evsel__set_leader(evsel, evsel__leader(metric_event));
106 	list_add_tail(&evsel->core.node, list);
107 	return 0;
108 }
109