xref: /openbmc/linux/tools/perf/arch/x86/util/topdown.c (revision d7955ce4)
1 // SPDX-License-Identifier: GPL-2.0
2 #include "api/fs/fs.h"
3 #include "util/evsel.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 /* Check whether there is a PMU which supports the perf metrics. */
11 bool topdown_sys_has_perf_metrics(void)
12 {
13 	static bool has_perf_metrics;
14 	static bool cached;
15 	struct perf_pmu *pmu;
16 
17 	if (cached)
18 		return has_perf_metrics;
19 
20 	/*
21 	 * The perf metrics feature is a core PMU feature.
22 	 * The PERF_TYPE_RAW type is the type of a core PMU.
23 	 * The slots event is only available when the core PMU
24 	 * supports the perf metrics feature.
25 	 */
26 	pmu = perf_pmus__find_by_type(PERF_TYPE_RAW);
27 	if (pmu && perf_pmu__have_event(pmu, "slots"))
28 		has_perf_metrics = true;
29 
30 	cached = true;
31 	return has_perf_metrics;
32 }
33 
34 #define TOPDOWN_SLOTS		0x0400
35 
36 /*
37  * Check whether a topdown group supports sample-read.
38  *
39  * Only Topdown metric supports sample-read. The slots
40  * event must be the leader of the topdown group.
41  */
42 bool arch_topdown_sample_read(struct evsel *leader)
43 {
44 	if (!evsel__sys_has_perf_metrics(leader))
45 		return false;
46 
47 	if (leader->core.attr.config == TOPDOWN_SLOTS)
48 		return true;
49 
50 	return false;
51 }
52