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/evsel.h"
  16 #include "../../util/evlist.h"
  17 #include "../../util/session.h"
  18 #include "../../util/util.h"
  19 #include "../../util/pmu.h"
  20 #include "../../util/debug.h"
  21 #include "../../util/auxtrace.h"
  22 #include "../../util/arm-spe.h"
  23
  24 #define KiB(x) ((x) * 1024)
  25 #define MiB(x) ((x) * 1024 * 1024)
  26
  27 struct arm_spe_recording {
  28         struct auxtrace_record          itr;
  29         struct perf_pmu                 *arm_spe_pmu;
  30         struct perf_evlist              *evlist;
  31 };
  32
  33 static size_t
  34 arm_spe_info_priv_size(struct auxtrace_record *itr __maybe_unused,
  35                        struct perf_evlist *evlist __maybe_unused)
  36 {
  37         return ARM_SPE_AUXTRACE_PRIV_SIZE;
  38 }
  39
  40 static int arm_spe_info_fill(struct auxtrace_record *itr,
  41                              struct perf_session *session,
  42                              struct auxtrace_info_event *auxtrace_info,
  43                              size_t priv_size)
  44 {
  45         struct arm_spe_recording *sper =
  46                         container_of(itr, struct arm_spe_recording, itr);
  47         struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
  48
  49         if (priv_size != ARM_SPE_AUXTRACE_PRIV_SIZE)
  50                 return -EINVAL;
  51
  52         if (!session->evlist->nr_mmaps)
  53                 return -EINVAL;
  54
  55         auxtrace_info->type = PERF_AUXTRACE_ARM_SPE;
  56         auxtrace_info->priv[ARM_SPE_PMU_TYPE] = arm_spe_pmu->type;
  57
  58         return 0;
  59 }
  60
  61 static int arm_spe_recording_options(struct auxtrace_record *itr,
  62                                      struct perf_evlist *evlist,
  63                                      struct record_opts *opts)
  64 {
  65         struct arm_spe_recording *sper =
  66                         container_of(itr, struct arm_spe_recording, itr);
  67         struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
  68         struct perf_evsel *evsel, *arm_spe_evsel = NULL;
  69         bool privileged = geteuid() == 0 || perf_event_paranoid() < 0;
  70         struct perf_evsel *tracking_evsel;
  71         int err;
  72
  73         sper->evlist = evlist;
  74
  75         evlist__for_each_entry(evlist, evsel) {
  76                 if (evsel->attr.type == arm_spe_pmu->type) {
  77                         if (arm_spe_evsel) {
  78                                 pr_err("There may be only one " ARM_SPE_PMU_NAME "x event\n");
  79                                 return -EINVAL;
  80                         }
  81                         evsel->attr.freq = 0;
  82                         evsel->attr.sample_period = 1;
  83                         arm_spe_evsel = evsel;
  84                         opts->full_auxtrace = true;
  85                 }
  86         }
  87
  88         if (!opts->full_auxtrace)
  89                 return 0;
  90
  91         /* We are in full trace mode but '-m,xyz' wasn't specified */
  92         if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
  93                 if (privileged) {
  94                         opts->auxtrace_mmap_pages = MiB(4) / page_size;
  95                 } else {
  96                         opts->auxtrace_mmap_pages = KiB(128) / page_size;
  97                         if (opts->mmap_pages == UINT_MAX)
  98                                 opts->mmap_pages = KiB(256) / page_size;
  99                 }
 100         }
 101
 102         /* Validate auxtrace_mmap_pages */
 103         if (opts->auxtrace_mmap_pages) {
 104                 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
 105                 size_t min_sz = KiB(8);
 106
 107                 if (sz < min_sz || !is_power_of_2(sz)) {
 108                         pr_err("Invalid mmap size for ARM SPE: must be at least %zuKiB and a power of 2\n",
 109                                min_sz / 1024);
 110                         return -EINVAL;
 111                 }
 112         }
 113
 114
 115         /*
 116          * To obtain the auxtrace buffer file descriptor, the auxtrace event
 117          * must come first.
 118          */
 119         perf_evlist__to_front(evlist, arm_spe_evsel);
 120
 121         perf_evsel__set_sample_bit(arm_spe_evsel, CPU);
 122         perf_evsel__set_sample_bit(arm_spe_evsel, TIME);
 123         perf_evsel__set_sample_bit(arm_spe_evsel, TID);
 124
 125         /* Add dummy event to keep tracking */
 126         err = parse_events(evlist, "dummy:u", NULL);
 127         if (err)
 128                 return err;
 129
 130         tracking_evsel = perf_evlist__last(evlist);
 131         perf_evlist__set_tracking_event(evlist, tracking_evsel);
 132
 133         tracking_evsel->attr.freq = 0;
 134         tracking_evsel->attr.sample_period = 1;
 135         perf_evsel__set_sample_bit(tracking_evsel, TIME);
 136         perf_evsel__set_sample_bit(tracking_evsel, CPU);
 137         perf_evsel__reset_sample_bit(tracking_evsel, BRANCH_STACK);
 138
 139         return 0;
 140 }
 141
 142 static u64 arm_spe_reference(struct auxtrace_record *itr __maybe_unused)
 143 {
 144         struct timespec ts;
 145
 146         clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
 147
 148         return ts.tv_sec ^ ts.tv_nsec;
 149 }
 150
 151 static void arm_spe_recording_free(struct auxtrace_record *itr)
 152 {
 153         struct arm_spe_recording *sper =
 154                         container_of(itr, struct arm_spe_recording, itr);
 155
 156         free(sper);
 157 }
 158
 159 static int arm_spe_read_finish(struct auxtrace_record *itr, int idx)
 160 {
 161         struct arm_spe_recording *sper =
 162                         container_of(itr, struct arm_spe_recording, itr);
 163         struct perf_evsel *evsel;
 164
 165         evlist__for_each_entry(sper->evlist, evsel) {
 166                 if (evsel->attr.type == sper->arm_spe_pmu->type)
 167                         return perf_evlist__enable_event_idx(sper->evlist,
 168                                                              evsel, idx);
 169         }
 170         return -EINVAL;
 171 }
 172
 173 struct auxtrace_record *arm_spe_recording_init(int *err,
 174                                                struct perf_pmu *arm_spe_pmu)
 175 {
 176         struct arm_spe_recording *sper;
 177
 178         if (!arm_spe_pmu) {
 179                 *err = -ENODEV;
 180                 return NULL;
 181         }
 182
 183         sper = zalloc(sizeof(struct arm_spe_recording));
 184         if (!sper) {
 185                 *err = -ENOMEM;
 186                 return NULL;
 187         }
 188
 189         sper->arm_spe_pmu = arm_spe_pmu;
 190         sper->itr.recording_options = arm_spe_recording_options;
 191         sper->itr.info_priv_size = arm_spe_info_priv_size;
 192         sper->itr.info_fill = arm_spe_info_fill;
 193         sper->itr.free = arm_spe_recording_free;
 194         sper->itr.reference = arm_spe_reference;
 195         sper->itr.read_finish = arm_spe_read_finish;
 196         sper->itr.alignment = 0;
 197
 198         *err = 0;
 199         return &sper->itr;
 200 }
 201
 202 struct perf_event_attr
 203 *arm_spe_pmu_default_config(struct perf_pmu *arm_spe_pmu)
 204 {
 205         struct perf_event_attr *attr;
 206
 207         attr = zalloc(sizeof(struct perf_event_attr));
 208         if (!attr) {
 209                 pr_err("arm_spe default config cannot allocate a perf_event_attr\n");
 210                 return NULL;
 211         }
 212
 213         /*
 214          * If kernel driver doesn't advertise a minimum,
 215          * use max allowable by PMSIDR_EL1.INTERVAL
 216          */
 217         if (perf_pmu__scan_file(arm_spe_pmu, "caps/min_interval", "%llu",
 218                                   &attr->sample_period) != 1) {
 219                 pr_debug("arm_spe driver doesn't advertise a min. interval. Using 4096\n");
 220                 attr->sample_period = 4096;
 221         }
 222
 223         arm_spe_pmu->selectable = true;
 224         arm_spe_pmu->is_uncore = false;
 225
 226         return attr;
 227 }