tools/perf/arch/s390/util/auxtrace.c

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