xref: /linux/tools/perf/arch/x86/util/topdown.c (revision f4f346c3465949ebba80c6cc52cd8d2eeaa545fd)
1 // SPDX-License-Identifier: GPL-2.0
2 #include "util/evlist.h"
3 #include "util/pmu.h"
4 #include "util/pmus.h"
5 #include "util/topdown.h"
6 #include "topdown.h"
7 #include "evsel.h"
8 
9 // cmask=0, inv=0, pc=0, edge=0, umask=4, event=0
10 #define TOPDOWN_SLOTS		0x0400
11 
12 /* Check whether there is a PMU which supports the perf metrics. */
topdown_sys_has_perf_metrics(void)13 bool topdown_sys_has_perf_metrics(void)
14 {
15 	static bool has_perf_metrics;
16 	static bool cached;
17 	struct perf_pmu *pmu;
18 
19 	if (cached)
20 		return has_perf_metrics;
21 
22 	/*
23 	 * The perf metrics feature is a core PMU feature.
24 	 * The PERF_TYPE_RAW type is the type of a core PMU.
25 	 * The slots event is only available when the core PMU
26 	 * supports the perf metrics feature.
27 	 */
28 	pmu = perf_pmus__find_by_type(PERF_TYPE_RAW);
29 	if (pmu && perf_pmu__have_event(pmu, "slots"))
30 		has_perf_metrics = true;
31 
32 	cached = true;
33 	return has_perf_metrics;
34 }
35 
arch_is_topdown_slots(const struct evsel * evsel)36 bool arch_is_topdown_slots(const struct evsel *evsel)
37 {
38 	return evsel->core.attr.type == PERF_TYPE_RAW &&
39 	       evsel->core.attr.config == TOPDOWN_SLOTS &&
40 	       evsel->core.attr.config1 == 0;
41 }
42 
arch_is_topdown_metrics(const struct evsel * evsel)43 bool arch_is_topdown_metrics(const struct evsel *evsel)
44 {
45 	// cmask=0, inv=0, pc=0, edge=0, umask=0x80-0x87, event=0
46 	return evsel->core.attr.type == PERF_TYPE_RAW &&
47 		(evsel->core.attr.config & 0xFFFFF8FF) == 0x8000 &&
48 		evsel->core.attr.config1 == 0;
49 }
50 
51 /*
52  * Check whether a topdown group supports sample-read.
53  *
54  * Only Topdown metric supports sample-read. The slots
55  * event must be the leader of the topdown group.
56  */
arch_topdown_sample_read(struct evsel * leader)57 bool arch_topdown_sample_read(struct evsel *leader)
58 {
59 	struct evsel *evsel;
60 
61 	if (!evsel__sys_has_perf_metrics(leader))
62 		return false;
63 
64 	if (!arch_is_topdown_slots(leader))
65 		return false;
66 
67 	/*
68 	 * If slots event as leader event but no topdown metric events
69 	 * in group, slots event should still sample as leader.
70 	 */
71 	evlist__for_each_entry(leader->evlist, evsel) {
72 		if (evsel->core.leader != leader->core.leader)
73 			continue;
74 		if (evsel != leader && arch_is_topdown_metrics(evsel))
75 			return true;
76 	}
77 
78 	return false;
79 }
80 
81 /*
82  * Make a copy of the topdown metric event metric_event with the given index but
83  * change its configuration to be a topdown slots event. Copying from
84  * metric_event ensures modifiers are the same.
85  */
topdown_insert_slots_event(struct list_head * list,int idx,struct evsel * metric_event)86 int topdown_insert_slots_event(struct list_head *list, int idx, struct evsel *metric_event)
87 {
88 	struct evsel *evsel = evsel__new_idx(&metric_event->core.attr, idx);
89 
90 	if (!evsel)
91 		return -ENOMEM;
92 
93 	evsel->core.attr.config = TOPDOWN_SLOTS;
94 	evsel->core.cpus = perf_cpu_map__get(metric_event->core.cpus);
95 	evsel->core.pmu_cpus = perf_cpu_map__get(metric_event->core.pmu_cpus);
96 	evsel->core.is_pmu_core = true;
97 	evsel->pmu = metric_event->pmu;
98 	evsel->name = strdup("slots");
99 	evsel->precise_max = metric_event->precise_max;
100 	evsel->sample_read = metric_event->sample_read;
101 	evsel->weak_group = metric_event->weak_group;
102 	evsel->bpf_counter = metric_event->bpf_counter;
103 	evsel->retire_lat = metric_event->retire_lat;
104 	evsel__set_leader(evsel, evsel__leader(metric_event));
105 	list_add_tail(&evsel->core.node, list);
106 	return 0;
107 }
108