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

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