Commit | Line | Data |
---|---|---|
6faa26ca | 1 | /* |
9d16b343 | 2 | * Copyright (C) 2016 Julien Desfossez <jdesfossez@efficios.com> |
6faa26ca | 3 | * |
9d16b343 | 4 | * SPDX-License-Identifier: GPL-2.0-only |
6faa26ca | 5 | * |
6faa26ca JD |
6 | */ |
7 | ||
65702b8f | 8 | #include <errno.h> |
65702b8f JR |
9 | #include <linux/perf_event.h> |
10 | #include <perfmon/perf_event.h> | |
11 | #include <perfmon/pfmlib_perf_event.h> | |
28f23191 JG |
12 | #include <stdio.h> |
13 | #include <string.h> | |
65702b8f | 14 | |
6faa26ca JD |
15 | int main(int argc, char **argv) |
16 | { | |
65702b8f JR |
17 | int ret, fd; |
18 | ||
19 | /* pfm query objects */ | |
20 | pfm_perf_encode_arg_t pencoder; | |
21 | pfm_event_info_t info; | |
22 | ||
23 | /* Perf event object to be populated by libpfm */ | |
24 | struct perf_event_attr attr; | |
6faa26ca JD |
25 | |
26 | if (argc != 2) { | |
28f23191 JG |
27 | fprintf(stderr, |
28 | "Usage: %s <pmu counter to find>\n" | |
29 | "ex: %s UNHALTED_REFERENCE_CYCLES\n" | |
30 | "Returns the event raw number if found and actionable with" | |
31 | "return code 0.\n" | |
32 | "If not found returns 1," | |
33 | "If not actionable return 2," | |
34 | "on error returns 255\n", | |
35 | argv[0], | |
36 | argv[0]); | |
6faa26ca JD |
37 | ret = -1; |
38 | goto end; | |
39 | } | |
40 | ||
65702b8f JR |
41 | /* Initialize perf_event_attr. */ |
42 | memset(&attr, 0, sizeof(struct perf_event_attr)); | |
43 | ||
44 | /* Initialize libpfm encoder structure. */ | |
45 | memset(&pencoder, 0, sizeof(pencoder)); | |
46 | pencoder.size = sizeof(pfm_perf_encode_arg_t); | |
47 | ||
48 | /* Initialize libpfm event info structure. */ | |
49 | memset(&info, 0, sizeof(info)); | |
50 | info.size = sizeof(info); | |
51 | ||
52 | /* Prepare the encoder for query. */ | |
53 | pencoder.attr = &attr; /* Set the perf_event_attr pointer. */ | |
54 | pencoder.fstr = NULL; /* Not interested by the fully qualified event string. */ | |
6faa26ca JD |
55 | |
56 | ret = pfm_initialize(); | |
57 | if (ret != PFM_SUCCESS) { | |
28f23191 | 58 | fprintf(stderr, "Failed to initialise libpfm: %s", pfm_strerror(ret)); |
65702b8f JR |
59 | ret = 255; |
60 | goto end; | |
61 | } | |
62 | ||
28f23191 JG |
63 | ret = pfm_get_os_event_encoding( |
64 | argv[1], PFM_PLM0 | PFM_PLM1 | PFM_PLM2 | PFM_PLM3, PFM_OS_PERF_EVENT, &pencoder); | |
65702b8f | 65 | if (ret != PFM_SUCCESS) { |
28f23191 | 66 | fprintf(stderr, "libpfm: error pfm_get_os_event_encoding: %s\n", pfm_strerror(ret)); |
65702b8f JR |
67 | ret = 1; |
68 | goto end; | |
69 | } | |
70 | ||
71 | /* | |
72 | * Query the raw code for later use. Do it now to simplify error | |
73 | * management. | |
74 | */ | |
75 | ret = pfm_get_event_info(pencoder.idx, PFM_OS_NONE, &info); | |
76 | if (ret != PFM_SUCCESS) { | |
77 | fprintf(stderr, "libpfm: error pfm_get_event_info: %s\n", pfm_strerror(ret)); | |
78 | ret = 1; | |
6faa26ca JD |
79 | goto end; |
80 | } | |
81 | ||
65702b8f JR |
82 | /* |
83 | * Now that the event is found, try to use it to validate that | |
84 | * the current user has access to it and that it can be used on that | |
85 | * host. | |
86 | */ | |
87 | ||
88 | /* Set the event to disabled to prevent unnecessary side effects. */ | |
89 | pencoder.attr->disabled = 1; | |
90 | ||
91 | /* perf_event_open is provided by perfmon/perf_event.h. */ | |
92 | fd = perf_event_open(pencoder.attr, 0, -1, -1, 0); | |
93 | if (fd == -1) { | |
28f23191 | 94 | fprintf(stderr, "perf: error perf_event_open: %d: %s\n", errno, strerror(errno)); |
65702b8f JR |
95 | ret = 2; |
96 | goto end; | |
6faa26ca JD |
97 | } |
98 | ||
65702b8f JR |
99 | /* We close the fd immediately since the event is actionable. */ |
100 | close(fd); | |
101 | ||
102 | /* Output the raw code for the event */ | |
103 | fprintf(stdout, "r%" PRIx64 "\n", info.code); | |
104 | ret = 0; | |
6faa26ca JD |
105 | |
106 | end: | |
107 | return ret; | |
108 | } |