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 <time.h>
  12
  13 #include "../../util/cpumap.h"
  14 #include "../../util/evsel.h"
  15 #include "../../util/evlist.h"
  16 #include "../../util/session.h"
  17 #include "../../util/util.h"
  18 #include "../../util/pmu.h"
  19 #include "../../util/debug.h"
  20 #include "../../util/auxtrace.h"
  21 #include "../../util/arm-spe.h"
  22
  23 #define KiB(x) ((x) * 1024)
  24 #define MiB(x) ((x) * 1024 * 1024)
  25
  26 struct arm_spe_recording {
  27         struct auxtrace_record          itr;
  28         struct perf_pmu                 *arm_spe_pmu;
  29         struct perf_evlist              *evlist;
  30 };
  31
  32 static size_t
  33 arm_spe_info_priv_size(struct auxtrace_record *itr __maybe_unused,
  34                        struct perf_evlist *evlist __maybe_unused)
  35 {
  36         return ARM_SPE_AUXTRACE_PRIV_SIZE;
  37 }
  38
  39 static int arm_spe_info_fill(struct auxtrace_record *itr,
  40                              struct perf_session *session,
  41                              struct auxtrace_info_event *auxtrace_info,
  42                              size_t priv_size)
  43 {
  44         struct arm_spe_recording *sper =
  45                         container_of(itr, struct arm_spe_recording, itr);
  46         struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
  47
  48         if (priv_size != ARM_SPE_AUXTRACE_PRIV_SIZE)
  49                 return -EINVAL;
  50
  51         if (!session->evlist->nr_mmaps)
  52                 return -EINVAL;
  53
  54         auxtrace_info->type = PERF_AUXTRACE_ARM_SPE;
  55         auxtrace_info->priv[ARM_SPE_PMU_TYPE] = arm_spe_pmu->type;
  56
  57         return 0;
  58 }
  59
  60 static int arm_spe_recording_options(struct auxtrace_record *itr,
  61                                      struct perf_evlist *evlist,
  62                                      struct record_opts *opts)
  63 {
  64         struct arm_spe_recording *sper =
  65                         container_of(itr, struct arm_spe_recording, itr);
  66         struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
  67         struct perf_evsel *evsel, *arm_spe_evsel = NULL;
  68         bool privileged = geteuid() == 0 || perf_event_paranoid() < 0;
  69         struct perf_evsel *tracking_evsel;
  70         int err;
  71
  72         sper->evlist = evlist;
  73
  74         evlist__for_each_entry(evlist, evsel) {
  75                 if (evsel->attr.type == arm_spe_pmu->type) {
  76                         if (arm_spe_evsel) {
  77                                 pr_err("There may be only one " ARM_SPE_PMU_NAME "x event\n");
  78                                 return -EINVAL;
  79                         }
  80                         evsel->attr.freq = 0;
  81                         evsel->attr.sample_period = 1;
  82                         arm_spe_evsel = evsel;
  83                         opts->full_auxtrace = true;
  84                 }
  85         }
  86
  87         if (!opts->full_auxtrace)
  88                 return 0;
  89
  90         /* We are in full trace mode but '-m,xyz' wasn't specified */
  91         if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
  92                 if (privileged) {
  93                         opts->auxtrace_mmap_pages = MiB(4) / page_size;
  94                 } else {
  95                         opts->auxtrace_mmap_pages = KiB(128) / page_size;
  96                         if (opts->mmap_pages == UINT_MAX)
  97                                 opts->mmap_pages = KiB(256) / page_size;
  98                 }
  99         }
 100
 101         /* Validate auxtrace_mmap_pages */
 102         if (opts->auxtrace_mmap_pages) {
 103                 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
 104                 size_t min_sz = KiB(8);
 105
 106                 if (sz < min_sz || !is_power_of_2(sz)) {
 107                         pr_err("Invalid mmap size for ARM SPE: must be at least %zuKiB and a power of 2\n",
 108                                min_sz / 1024);
 109                         return -EINVAL;
 110                 }
 111         }
 112
 113
 114         /*
 115          * To obtain the auxtrace buffer file descriptor, the auxtrace event
 116          * must come first.
 117          */
 118         perf_evlist__to_front(evlist, arm_spe_evsel);
 119
 120         perf_evsel__set_sample_bit(arm_spe_evsel, CPU);
 121         perf_evsel__set_sample_bit(arm_spe_evsel, TIME);
 122         perf_evsel__set_sample_bit(arm_spe_evsel, TID);
 123
 124         /* Add dummy event to keep tracking */
 125         err = parse_events(evlist, "dummy:u", NULL);
 126         if (err)
 127                 return err;
 128
 129         tracking_evsel = perf_evlist__last(evlist);
 130         perf_evlist__set_tracking_event(evlist, tracking_evsel);
 131
 132         tracking_evsel->attr.freq = 0;
 133         tracking_evsel->attr.sample_period = 1;
 134         perf_evsel__set_sample_bit(tracking_evsel, TIME);
 135         perf_evsel__set_sample_bit(tracking_evsel, CPU);
 136         perf_evsel__reset_sample_bit(tracking_evsel, BRANCH_STACK);
 137
 138         return 0;
 139 }
 140
 141 static u64 arm_spe_reference(struct auxtrace_record *itr __maybe_unused)
 142 {
 143         struct timespec ts;
 144
 145         clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
 146
 147         return ts.tv_sec ^ ts.tv_nsec;
 148 }
 149
 150 static void arm_spe_recording_free(struct auxtrace_record *itr)
 151 {
 152         struct arm_spe_recording *sper =
 153                         container_of(itr, struct arm_spe_recording, itr);
 154
 155         free(sper);
 156 }
 157
 158 static int arm_spe_read_finish(struct auxtrace_record *itr, int idx)
 159 {
 160         struct arm_spe_recording *sper =
 161                         container_of(itr, struct arm_spe_recording, itr);
 162         struct perf_evsel *evsel;
 163
 164         evlist__for_each_entry(sper->evlist, evsel) {
 165                 if (evsel->attr.type == sper->arm_spe_pmu->type)
 166                         return perf_evlist__enable_event_idx(sper->evlist,
 167                                                              evsel, idx);
 168         }
 169         return -EINVAL;
 170 }
 171
 172 struct auxtrace_record *arm_spe_recording_init(int *err,
 173                                                struct perf_pmu *arm_spe_pmu)
 174 {
 175         struct arm_spe_recording *sper;
 176
 177         if (!arm_spe_pmu) {
 178                 *err = -ENODEV;
 179                 return NULL;
 180         }
 181
 182         sper = zalloc(sizeof(struct arm_spe_recording));
 183         if (!sper) {
 184                 *err = -ENOMEM;
 185                 return NULL;
 186         }
 187
 188         sper->arm_spe_pmu = arm_spe_pmu;
 189         sper->itr.recording_options = arm_spe_recording_options;
 190         sper->itr.info_priv_size = arm_spe_info_priv_size;
 191         sper->itr.info_fill = arm_spe_info_fill;
 192         sper->itr.free = arm_spe_recording_free;
 193         sper->itr.reference = arm_spe_reference;
 194         sper->itr.read_finish = arm_spe_read_finish;
 195         sper->itr.alignment = 0;
 196
 197         return &sper->itr;
 198 }
 199
 200 struct perf_event_attr
 201 *arm_spe_pmu_default_config(struct perf_pmu *arm_spe_pmu)
 202 {
 203         struct perf_event_attr *attr;
 204
 205         attr = zalloc(sizeof(struct perf_event_attr));
 206         if (!attr) {
 207                 pr_err("arm_spe default config cannot allocate a perf_event_attr\n");
 208                 return NULL;
 209         }
 210
 211         /*
 212          * If kernel driver doesn't advertise a minimum,
 213          * use max allowable by PMSIDR_EL1.INTERVAL
 214          */
 215         if (perf_pmu__scan_file(arm_spe_pmu, "caps/min_interval", "%llu",
 216                                   &attr->sample_period) != 1) {
 217                 pr_debug("arm_spe driver doesn't advertise a min. interval. Using 4096\n");
 218                 attr->sample_period = 4096;
 219         }
 220
 221         arm_spe_pmu->selectable = true;
 222         arm_spe_pmu->is_uncore = false;
 223
 224         return attr;
 225 }