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         return 0;
  34 }
  35
  36 static unsigned long
  37 cpumsf_reference(struct auxtrace_record *itr __maybe_unused)
  38 {
  39         return 0;
  40 }
  41
  42 static int
  43 cpumsf_recording_options(struct auxtrace_record *ar __maybe_unused,
  44                          struct perf_evlist *evlist __maybe_unused,
  45                          struct record_opts *opts)
  46 {
  47         unsigned int factor = 1;
  48         unsigned int pages;
  49
  50         opts->full_auxtrace = true;
  51
  52         /*
  53          * The AUX buffer size should be set properly to avoid
  54          * overflow of samples if it is not set explicitly.
  55          * DEFAULT_AUX_PAGES is an proper size when sampling frequency
  56          * is DEFAULT_FREQ. It is expected to hold about 1/2 second
  57          * of sampling data. The size used for AUX buffer will scale
  58          * according to the specified frequency and DEFAULT_FREQ.
  59          */
  60         if (!opts->auxtrace_mmap_pages) {
  61                 if (opts->user_freq != UINT_MAX)
  62                         factor = (opts->user_freq + DEFAULT_FREQ
  63                                   - 1) / DEFAULT_FREQ;
  64                 pages = DEFAULT_AUX_PAGES * factor;
  65                 opts->auxtrace_mmap_pages = roundup_pow_of_two(pages);
  66         }
  67
  68         return 0;
  69 }
  70
  71 static int
  72 cpumsf_parse_snapshot_options(struct auxtrace_record *itr __maybe_unused,
  73                               struct record_opts *opts __maybe_unused,
  74                               const char *str __maybe_unused)
  75 {
  76         return 0;
  77 }
  78
  79 /*
  80  * auxtrace_record__init is called when perf record
  81  * check if the event really need auxtrace
  82  */
  83 struct auxtrace_record *auxtrace_record__init(struct perf_evlist *evlist,
  84                                               int *err)
  85 {
  86         struct auxtrace_record *aux;
  87         struct perf_evsel *pos;
  88         int diagnose = 0;
  89
  90         if (evlist->nr_entries == 0)
  91                 return NULL;
  92
  93         evlist__for_each_entry(evlist, pos) {
  94                 if (pos->attr.config == PERF_EVENT_CPUM_SF_DIAG) {
  95                         diagnose = 1;
  96                         break;
  97                 }
  98         }
  99
 100         if (!diagnose)
 101                 return NULL;
 102
 103         /* sampling in diagnose mode. alloc aux buffer */
 104         aux = zalloc(sizeof(*aux));
 105         if (aux == NULL) {
 106                 *err = -ENOMEM;
 107                 return NULL;
 108         }
 109
 110         aux->parse_snapshot_options = cpumsf_parse_snapshot_options;
 111         aux->recording_options = cpumsf_recording_options;
 112         aux->info_priv_size = cpumsf_info_priv_size;
 113         aux->info_fill = cpumsf_info_fill;
 114         aux->free = cpumsf_free;
 115         aux->reference = cpumsf_reference;
 116
 117         return aux;
 118 }