1#include <errno.h>
2#include <stdbool.h>
3#include <stdlib.h>
4#include <linux/kernel.h>
5#include <linux/types.h>
6#include <linux/bitops.h>
7#include <linux/log2.h>
8#include <linux/zalloc.h>
9
10#include "../../util/evlist.h"
11#include "../../util/auxtrace.h"
12#include "../../util/evsel.h"
13#include "../../util/record.h"
14
15#define PERF_EVENT_CPUM_SF 0xB0000 /* Event: Basic-sampling */
16#define PERF_EVENT_CPUM_SF_DIAG 0xBD000 /* Event: Combined-sampling */
17#define DEFAULT_AUX_PAGES 128
18#define DEFAULT_FREQ 4000
19
20static void cpumsf_free(struct auxtrace_record *itr)
21{
22 free(itr);
23}
24
25static size_t cpumsf_info_priv_size(struct auxtrace_record *itr __maybe_unused,
26 struct evlist *evlist __maybe_unused)
27{
28 return 0;
29}
30
31static int
32cpumsf_info_fill(struct auxtrace_record *itr __maybe_unused,
33 struct perf_session *session __maybe_unused,
34 struct perf_record_auxtrace_info *auxtrace_info __maybe_unused,
35 size_t priv_size __maybe_unused)
36{
37 auxtrace_info->type = PERF_AUXTRACE_S390_CPUMSF;
38 return 0;
39}
40
41static unsigned long
42cpumsf_reference(struct auxtrace_record *itr __maybe_unused)
43{
44 return 0;
45}
46
47static int
48cpumsf_recording_options(struct auxtrace_record *ar __maybe_unused,
49 struct evlist *evlist __maybe_unused,
50 struct record_opts *opts)
51{
52 unsigned int factor = 1;
53 unsigned int pages;
54
55 opts->full_auxtrace = true;
56
57 /*
58 * The AUX buffer size should be set properly to avoid
59 * overflow of samples if it is not set explicitly.
60 * DEFAULT_AUX_PAGES is an proper size when sampling frequency
61 * is DEFAULT_FREQ. It is expected to hold about 1/2 second
62 * of sampling data. The size used for AUX buffer will scale
63 * according to the specified frequency and DEFAULT_FREQ.
64 */
65 if (!opts->auxtrace_mmap_pages) {
66 if (opts->user_freq != UINT_MAX)
67 factor = (opts->user_freq + DEFAULT_FREQ
68 - 1) / DEFAULT_FREQ;
69 pages = DEFAULT_AUX_PAGES * factor;
70 opts->auxtrace_mmap_pages = roundup_pow_of_two(pages);
71 }
72
73 return 0;
74}
75
76static int
77cpumsf_parse_snapshot_options(struct auxtrace_record *itr __maybe_unused,
78 struct record_opts *opts __maybe_unused,
79 const char *str __maybe_unused)
80{
81 return 0;
82}
83
84/*
85 * auxtrace_record__init is called when perf record
86 * check if the event really need auxtrace
87 */
88struct auxtrace_record *auxtrace_record__init(struct evlist *evlist,
89 int *err)
90{
91 struct auxtrace_record *aux;
92 struct evsel *pos;
93 int diagnose = 0;
94
95 *err = 0;
96 if (evlist->core.nr_entries == 0)
97 return NULL;
98
99 evlist__for_each_entry(evlist, pos) {
100 if (pos->core.attr.config == PERF_EVENT_CPUM_SF_DIAG) {
101 diagnose = 1;
102 pos->needs_auxtrace_mmap = true;
103 break;
104 }
105 }
106
107 if (!diagnose)
108 return NULL;
109
110 /* sampling in diagnose mode. alloc aux buffer */
111 aux = zalloc(sizeof(*aux));
112 if (aux == NULL) {
113 *err = -ENOMEM;
114 return NULL;
115 }
116
117 aux->parse_snapshot_options = cpumsf_parse_snapshot_options;
118 aux->recording_options = cpumsf_recording_options;
119 aux->info_priv_size = cpumsf_info_priv_size;
120 aux->info_fill = cpumsf_info_fill;
121 aux->free = cpumsf_free;
122 aux->reference = cpumsf_reference;
123
124 return aux;
125}
126

source code of linux/tools/perf/arch/s390/util/auxtrace.c