tools/perf/arch/arm64/util/arm-spe.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Arm Statistical Profiling Extensions (SPE) support
   4  * Copyright (c) 2017-2018, Arm Ltd.
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/types.h>
   9 #include <linux/bitops.h>
  10 #include <linux/log2.h>
  11 #include <linux/zalloc.h>
  12 #include <time.h>
  13
  14 #include "../../../util/cpumap.h"
  15 #include "../../../util/event.h"
  16 #include "../../../util/evsel.h"
  17 #include "../../../util/evlist.h"
  18 #include "../../../util/session.h"
  19 #include <internal/lib.h> // page_size
  20 #include "../../../util/pmu.h"
  21 #include "../../../util/debug.h"
  22 #include "../../../util/auxtrace.h"
  23 #include "../../../util/record.h"
  24 #include "../../../util/arm-spe.h"
  25
  26 #define KiB(x) ((x) * 1024)
  27 #define MiB(x) ((x) * 1024 * 1024)
  28
  29 struct arm_spe_recording {
  30         struct auxtrace_record          itr;
  31         struct perf_pmu                 *arm_spe_pmu;
  32         struct evlist           *evlist;
  33 };
  34
  35 static size_t
  36 arm_spe_info_priv_size(struct auxtrace_record *itr __maybe_unused,
  37                        struct evlist *evlist __maybe_unused)
  38 {
  39         return ARM_SPE_AUXTRACE_PRIV_SIZE;
  40 }
  41
  42 static int arm_spe_info_fill(struct auxtrace_record *itr,
  43                              struct perf_session *session,
  44                              struct perf_record_auxtrace_info *auxtrace_info,
  45                              size_t priv_size)
  46 {
  47         struct arm_spe_recording *sper =
  48                         container_of(itr, struct arm_spe_recording, itr);
  49         struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
  50
  51         if (priv_size != ARM_SPE_AUXTRACE_PRIV_SIZE)
  52                 return -EINVAL;
  53
  54         if (!session->evlist->core.nr_mmaps)
  55                 return -EINVAL;
  56
  57         auxtrace_info->type = PERF_AUXTRACE_ARM_SPE;
  58         auxtrace_info->priv[ARM_SPE_PMU_TYPE] = arm_spe_pmu->type;
  59
  60         return 0;
  61 }
  62
  63 static int arm_spe_recording_options(struct auxtrace_record *itr,
  64                                      struct evlist *evlist,
  65                                      struct record_opts *opts)
  66 {
  67         struct arm_spe_recording *sper =
  68                         container_of(itr, struct arm_spe_recording, itr);
  69         struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
  70         struct evsel *evsel, *arm_spe_evsel = NULL;
  71         bool privileged = perf_event_paranoid_check(-1);
  72         struct evsel *tracking_evsel;
  73         int err;
  74
  75         sper->evlist = evlist;
  76
  77         evlist__for_each_entry(evlist, evsel) {
  78                 if (evsel->core.attr.type == arm_spe_pmu->type) {
  79                         if (arm_spe_evsel) {
  80                                 pr_err("There may be only one " ARM_SPE_PMU_NAME "x event\n");
  81                                 return -EINVAL;
  82                         }
  83                         evsel->core.attr.freq = 0;
  84                         evsel->core.attr.sample_period = 1;
  85                         arm_spe_evsel = evsel;
  86                         opts->full_auxtrace = true;
  87                 }
  88         }
  89
  90         if (!opts->full_auxtrace)
  91                 return 0;
  92
  93         /* We are in full trace mode but '-m,xyz' wasn't specified */
  94         if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
  95                 if (privileged) {
  96                         opts->auxtrace_mmap_pages = MiB(4) / page_size;
  97                 } else {
  98                         opts->auxtrace_mmap_pages = KiB(128) / page_size;
  99                         if (opts->mmap_pages == UINT_MAX)
 100                                 opts->mmap_pages = KiB(256) / page_size;
 101                 }
 102         }
 103
 104         /* Validate auxtrace_mmap_pages */
 105         if (opts->auxtrace_mmap_pages) {
 106                 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
 107                 size_t min_sz = KiB(8);
 108
 109                 if (sz < min_sz || !is_power_of_2(sz)) {
 110                         pr_err("Invalid mmap size for ARM SPE: must be at least %zuKiB and a power of 2\n",
 111                                min_sz / 1024);
 112                         return -EINVAL;
 113                 }
 114         }
 115
 116
 117         /*
 118          * To obtain the auxtrace buffer file descriptor, the auxtrace event
 119          * must come first.
 120          */
 121         evlist__to_front(evlist, arm_spe_evsel);
 122
 123         evsel__set_sample_bit(arm_spe_evsel, CPU);
 124         evsel__set_sample_bit(arm_spe_evsel, TIME);
 125         evsel__set_sample_bit(arm_spe_evsel, TID);
 126
 127         /* Add dummy event to keep tracking */
 128         err = parse_events(evlist, "dummy:u", NULL);
 129         if (err)
 130                 return err;
 131
 132         tracking_evsel = evlist__last(evlist);
 133         evlist__set_tracking_event(evlist, tracking_evsel);
 134
 135         tracking_evsel->core.attr.freq = 0;
 136         tracking_evsel->core.attr.sample_period = 1;
 137         evsel__set_sample_bit(tracking_evsel, TIME);
 138         evsel__set_sample_bit(tracking_evsel, CPU);
 139         evsel__reset_sample_bit(tracking_evsel, BRANCH_STACK);
 140
 141         return 0;
 142 }
 143
 144 static u64 arm_spe_reference(struct auxtrace_record *itr __maybe_unused)
 145 {
 146         struct timespec ts;
 147
 148         clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
 149
 150         return ts.tv_sec ^ ts.tv_nsec;
 151 }
 152
 153 static void arm_spe_recording_free(struct auxtrace_record *itr)
 154 {
 155         struct arm_spe_recording *sper =
 156                         container_of(itr, struct arm_spe_recording, itr);
 157
 158         free(sper);
 159 }
 160
 161 struct auxtrace_record *arm_spe_recording_init(int *err,
 162                                                struct perf_pmu *arm_spe_pmu)
 163 {
 164         struct arm_spe_recording *sper;
 165
 166         if (!arm_spe_pmu) {
 167                 *err = -ENODEV;
 168                 return NULL;
 169         }
 170
 171         sper = zalloc(sizeof(struct arm_spe_recording));
 172         if (!sper) {
 173                 *err = -ENOMEM;
 174                 return NULL;
 175         }
 176
 177         sper->arm_spe_pmu = arm_spe_pmu;
 178         sper->itr.pmu = arm_spe_pmu;
 179         sper->itr.recording_options = arm_spe_recording_options;
 180         sper->itr.info_priv_size = arm_spe_info_priv_size;
 181         sper->itr.info_fill = arm_spe_info_fill;
 182         sper->itr.free = arm_spe_recording_free;
 183         sper->itr.reference = arm_spe_reference;
 184         sper->itr.read_finish = auxtrace_record__read_finish;
 185         sper->itr.alignment = 0;
 186
 187         *err = 0;
 188         return &sper->itr;
 189 }
 190
 191 struct perf_event_attr
 192 *arm_spe_pmu_default_config(struct perf_pmu *arm_spe_pmu)
 193 {
 194         struct perf_event_attr *attr;
 195
 196         attr = zalloc(sizeof(struct perf_event_attr));
 197         if (!attr) {
 198                 pr_err("arm_spe default config cannot allocate a perf_event_attr\n");
 199                 return NULL;
 200         }
 201
 202         /*
 203          * If kernel driver doesn't advertise a minimum,
 204          * use max allowable by PMSIDR_EL1.INTERVAL
 205          */
 206         if (perf_pmu__scan_file(arm_spe_pmu, "caps/min_interval", "%llu",
 207                                   &attr->sample_period) != 1) {
 208                 pr_debug("arm_spe driver doesn't advertise a min. interval. Using 4096\n");
 209                 attr->sample_period = 4096;
 210         }
 211
 212         arm_spe_pmu->selectable = true;
 213         arm_spe_pmu->is_uncore = false;
 214
 215         return attr;
 216 }