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