blob: 51ccbfd3d246d484400c9a83220efaa8833f9f95 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Arm Statistical Profiling Extensions (SPE) support
* Copyright (c) 2017-2018, Arm Ltd.
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/log2.h>
#include <linux/zalloc.h>
#include <time.h>
#include "../../../util/cpumap.h"
#include "../../../util/event.h"
#include "../../../util/evsel.h"
#include "../../../util/evsel_config.h"
#include "../../../util/evlist.h"
#include "../../../util/session.h"
#include <internal/lib.h> // page_size
#include "../../../util/pmu.h"
#include "../../../util/debug.h"
#include "../../../util/auxtrace.h"
#include "../../../util/record.h"
#include "../../../util/arm-spe.h"
#include <tools/libc_compat.h> // reallocarray
#define KiB(x) ((x) * 1024)
#define MiB(x) ((x) * 1024 * 1024)
struct arm_spe_recording {
struct auxtrace_record itr;
struct perf_pmu *arm_spe_pmu;
struct evlist *evlist;
int wrapped_cnt;
bool *wrapped;
};
static size_t
arm_spe_info_priv_size(struct auxtrace_record *itr __maybe_unused,
struct evlist *evlist __maybe_unused)
{
return ARM_SPE_AUXTRACE_PRIV_SIZE;
}
static int arm_spe_info_fill(struct auxtrace_record *itr,
struct perf_session *session,
struct perf_record_auxtrace_info *auxtrace_info,
size_t priv_size)
{
struct arm_spe_recording *sper =
container_of(itr, struct arm_spe_recording, itr);
struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
if (priv_size != ARM_SPE_AUXTRACE_PRIV_SIZE)
return -EINVAL;
if (!session->evlist->core.nr_mmaps)
return -EINVAL;
auxtrace_info->type = PERF_AUXTRACE_ARM_SPE;
auxtrace_info->priv[ARM_SPE_PMU_TYPE] = arm_spe_pmu->type;
return 0;
}
static void
arm_spe_snapshot_resolve_auxtrace_defaults(struct record_opts *opts,
bool privileged)
{
/*
* The default snapshot size is the auxtrace mmap size. If neither auxtrace mmap size nor
* snapshot size is specified, then the default is 4MiB for privileged users, 128KiB for
* unprivileged users.
*
* The default auxtrace mmap size is 4MiB/page_size for privileged users, 128KiB for
* unprivileged users. If an unprivileged user does not specify mmap pages, the mmap pages
* will be reduced from the default 512KiB/page_size to 256KiB/page_size, otherwise the
* user is likely to get an error as they exceed their mlock limmit.
*/
/*
* No size were given to '-S' or '-m,', so go with the default
*/
if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) {
if (privileged) {
opts->auxtrace_mmap_pages = MiB(4) / page_size;
} else {
opts->auxtrace_mmap_pages = KiB(128) / page_size;
if (opts->mmap_pages == UINT_MAX)
opts->mmap_pages = KiB(256) / page_size;
}
} else if (!opts->auxtrace_mmap_pages && !privileged && opts->mmap_pages == UINT_MAX) {
opts->mmap_pages = KiB(256) / page_size;
}
/*
* '-m,xyz' was specified but no snapshot size, so make the snapshot size as big as the
* auxtrace mmap area.
*/
if (!opts->auxtrace_snapshot_size)
opts->auxtrace_snapshot_size = opts->auxtrace_mmap_pages * (size_t)page_size;
/*
* '-Sxyz' was specified but no auxtrace mmap area, so make the auxtrace mmap area big
* enough to fit the requested snapshot size.
*/
if (!opts->auxtrace_mmap_pages) {
size_t sz = opts->auxtrace_snapshot_size;
sz = round_up(sz, page_size) / page_size;
opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
}
}
static __u64 arm_spe_pmu__sample_period(const struct perf_pmu *arm_spe_pmu)
{
static __u64 sample_period;
if (sample_period)
return sample_period;
/*
* If kernel driver doesn't advertise a minimum,
* use max allowable by PMSIDR_EL1.INTERVAL
*/
if (perf_pmu__scan_file(arm_spe_pmu, "caps/min_interval", "%llu",
&sample_period) != 1) {
pr_debug("arm_spe driver doesn't advertise a min. interval. Using 4096\n");
sample_period = 4096;
}
return sample_period;
}
static int arm_spe_recording_options(struct auxtrace_record *itr,
struct evlist *evlist,
struct record_opts *opts)
{
struct arm_spe_recording *sper =
container_of(itr, struct arm_spe_recording, itr);
struct perf_pmu *arm_spe_pmu = sper->arm_spe_pmu;
struct evsel *evsel, *arm_spe_evsel = NULL;
struct perf_cpu_map *cpus = evlist->core.user_requested_cpus;
bool privileged = perf_event_paranoid_check(-1);
struct evsel *tracking_evsel;
int err;
u64 bit;
sper->evlist = evlist;
evlist__for_each_entry(evlist, evsel) {
if (evsel->core.attr.type == arm_spe_pmu->type) {
if (arm_spe_evsel) {
pr_err("There may be only one " ARM_SPE_PMU_NAME "x event\n");
return -EINVAL;
}
evsel->core.attr.freq = 0;
evsel->core.attr.sample_period = arm_spe_pmu__sample_period(arm_spe_pmu);
evsel->needs_auxtrace_mmap = true;
arm_spe_evsel = evsel;
opts->full_auxtrace = true;
}
}
if (!opts->full_auxtrace)
return 0;
/*
* we are in snapshot mode.
*/
if (opts->auxtrace_snapshot_mode) {
/*
* Command arguments '-Sxyz' and/or '-m,xyz' are missing, so fill those in with
* default values.
*/
if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages)
arm_spe_snapshot_resolve_auxtrace_defaults(opts, privileged);
/*
* Snapshot size can't be bigger than the auxtrace area.
*/
if (opts->auxtrace_snapshot_size > opts->auxtrace_mmap_pages * (size_t)page_size) {
pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n",
opts->auxtrace_snapshot_size,
opts->auxtrace_mmap_pages * (size_t)page_size);
return -EINVAL;
}
/*
* Something went wrong somewhere - this shouldn't happen.
*/
if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages) {
pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n");
return -EINVAL;
}
}
/* We are in full trace mode but '-m,xyz' wasn't specified */
if (!opts->auxtrace_mmap_pages) {
if (privileged) {
opts->auxtrace_mmap_pages = MiB(4) / page_size;
} else {
opts->auxtrace_mmap_pages = KiB(128) / page_size;
if (opts->mmap_pages == UINT_MAX)
opts->mmap_pages = KiB(256) / page_size;
}
}
/* Validate auxtrace_mmap_pages */
if (opts->auxtrace_mmap_pages) {
size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
size_t min_sz = KiB(8);
if (sz < min_sz || !is_power_of_2(sz)) {
pr_err("Invalid mmap size for ARM SPE: must be at least %zuKiB and a power of 2\n",
min_sz / 1024);
return -EINVAL;
}
}
if (opts->auxtrace_snapshot_mode)
pr_debug2("%sx snapshot size: %zu\n", ARM_SPE_PMU_NAME,
opts->auxtrace_snapshot_size);
/*
* To obtain the auxtrace buffer file descriptor, the auxtrace event
* must come first.
*/
evlist__to_front(evlist, arm_spe_evsel);
/*
* In the case of per-cpu mmaps, sample CPU for AUX event;
* also enable the timestamp tracing for samples correlation.
*/
if (!perf_cpu_map__has_any_cpu_or_is_empty(cpus)) {
evsel__set_sample_bit(arm_spe_evsel, CPU);
evsel__set_config_if_unset(arm_spe_pmu, arm_spe_evsel,
"ts_enable", 1);
}
/*
* Set this only so that perf report knows that SPE generates memory info. It has no effect
* on the opening of the event or the SPE data produced.
*/
evsel__set_sample_bit(arm_spe_evsel, DATA_SRC);
/*
* The PHYS_ADDR flag does not affect the driver behaviour, it is used to
* inform that the resulting output's SPE samples contain physical addresses
* where applicable.
*/
bit = perf_pmu__format_bits(arm_spe_pmu, "pa_enable");
if (arm_spe_evsel->core.attr.config & bit)
evsel__set_sample_bit(arm_spe_evsel, PHYS_ADDR);
/* Add dummy event to keep tracking */
err = parse_event(evlist, "dummy:u");
if (err)
return err;
tracking_evsel = evlist__last(evlist);
evlist__set_tracking_event(evlist, tracking_evsel);
tracking_evsel->core.attr.freq = 0;
tracking_evsel->core.attr.sample_period = 1;
/* In per-cpu case, always need the time of mmap events etc */
if (!perf_cpu_map__has_any_cpu_or_is_empty(cpus)) {
evsel__set_sample_bit(tracking_evsel, TIME);
evsel__set_sample_bit(tracking_evsel, CPU);
/* also track task context switch */
if (!record_opts__no_switch_events(opts))
tracking_evsel->core.attr.context_switch = 1;
}
return 0;
}
static int arm_spe_parse_snapshot_options(struct auxtrace_record *itr __maybe_unused,
struct record_opts *opts,
const char *str)
{
unsigned long long snapshot_size = 0;
char *endptr;
if (str) {
snapshot_size = strtoull(str, &endptr, 0);
if (*endptr || snapshot_size > SIZE_MAX)
return -1;
}
opts->auxtrace_snapshot_mode = true;
opts->auxtrace_snapshot_size = snapshot_size;
return 0;
}
static int arm_spe_snapshot_start(struct auxtrace_record *itr)
{
struct arm_spe_recording *ptr =
container_of(itr, struct arm_spe_recording, itr);
struct evsel *evsel;
evlist__for_each_entry(ptr->evlist, evsel) {
if (evsel->core.attr.type == ptr->arm_spe_pmu->type)
return evsel__disable(evsel);
}
return -EINVAL;
}
static int arm_spe_snapshot_finish(struct auxtrace_record *itr)
{
struct arm_spe_recording *ptr =
container_of(itr, struct arm_spe_recording, itr);
struct evsel *evsel;
evlist__for_each_entry(ptr->evlist, evsel) {
if (evsel->core.attr.type == ptr->arm_spe_pmu->type)
return evsel__enable(evsel);
}
return -EINVAL;
}
static int arm_spe_alloc_wrapped_array(struct arm_spe_recording *ptr, int idx)
{
bool *wrapped;
int cnt = ptr->wrapped_cnt, new_cnt, i;
/*
* No need to allocate, so return early.
*/
if (idx < cnt)
return 0;
/*
* Make ptr->wrapped as big as idx.
*/
new_cnt = idx + 1;
/*
* Free'ed in arm_spe_recording_free().
*/
wrapped = reallocarray(ptr->wrapped, new_cnt, sizeof(bool));
if (!wrapped)
return -ENOMEM;
/*
* init new allocated values.
*/
for (i = cnt; i < new_cnt; i++)
wrapped[i] = false;
ptr->wrapped_cnt = new_cnt;
ptr->wrapped = wrapped;
return 0;
}
static bool arm_spe_buffer_has_wrapped(unsigned char *buffer,
size_t buffer_size, u64 head)
{
u64 i, watermark;
u64 *buf = (u64 *)buffer;
size_t buf_size = buffer_size;
/*
* Defensively handle the case where head might be continually increasing - if its value is
* equal or greater than the size of the ring buffer, then we can safely determine it has
* wrapped around. Otherwise, continue to detect if head might have wrapped.
*/
if (head >= buffer_size)
return true;
/*
* We want to look the very last 512 byte (chosen arbitrarily) in the ring buffer.
*/
watermark = buf_size - 512;
/*
* The value of head is somewhere within the size of the ring buffer. This can be that there
* hasn't been enough data to fill the ring buffer yet or the trace time was so long that
* head has numerically wrapped around. To find we need to check if we have data at the
* very end of the ring buffer. We can reliably do this because mmap'ed pages are zeroed
* out and there is a fresh mapping with every new session.
*/
/*
* head is less than 512 byte from the end of the ring buffer.
*/
if (head > watermark)
watermark = head;
/*
* Speed things up by using 64 bit transactions (see "u64 *buf" above)
*/
watermark /= sizeof(u64);
buf_size /= sizeof(u64);
/*
* If we find trace data at the end of the ring buffer, head has been there and has
* numerically wrapped around at least once.
*/
for (i = watermark; i < buf_size; i++)
if (buf[i])
return true;
return false;
}
static int arm_spe_find_snapshot(struct auxtrace_record *itr, int idx,
struct auxtrace_mmap *mm, unsigned char *data,
u64 *head, u64 *old)
{
int err;
bool wrapped;
struct arm_spe_recording *ptr =
container_of(itr, struct arm_spe_recording, itr);
/*
* Allocate memory to keep track of wrapping if this is the first
* time we deal with this *mm.
*/
if (idx >= ptr->wrapped_cnt) {
err = arm_spe_alloc_wrapped_array(ptr, idx);
if (err)
return err;
}
/*
* Check to see if *head has wrapped around. If it hasn't only the
* amount of data between *head and *old is snapshot'ed to avoid
* bloating the perf.data file with zeros. But as soon as *head has
* wrapped around the entire size of the AUX ring buffer it taken.
*/
wrapped = ptr->wrapped[idx];
if (!wrapped && arm_spe_buffer_has_wrapped(data, mm->len, *head)) {
wrapped = true;
ptr->wrapped[idx] = true;
}
pr_debug3("%s: mmap index %d old head %zu new head %zu size %zu\n",
__func__, idx, (size_t)*old, (size_t)*head, mm->len);
/*
* No wrap has occurred, we can just use *head and *old.
*/
if (!wrapped)
return 0;
/*
* *head has wrapped around - adjust *head and *old to pickup the
* entire content of the AUX buffer.
*/
if (*head >= mm->len) {
*old = *head - mm->len;
} else {
*head += mm->len;
*old = *head - mm->len;
}
return 0;
}
static u64 arm_spe_reference(struct auxtrace_record *itr __maybe_unused)
{
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC_RAW, &ts);
return ts.tv_sec ^ ts.tv_nsec;
}
static void arm_spe_recording_free(struct auxtrace_record *itr)
{
struct arm_spe_recording *sper =
container_of(itr, struct arm_spe_recording, itr);
zfree(&sper->wrapped);
free(sper);
}
struct auxtrace_record *arm_spe_recording_init(int *err,
struct perf_pmu *arm_spe_pmu)
{
struct arm_spe_recording *sper;
if (!arm_spe_pmu) {
*err = -ENODEV;
return NULL;
}
sper = zalloc(sizeof(struct arm_spe_recording));
if (!sper) {
*err = -ENOMEM;
return NULL;
}
sper->arm_spe_pmu = arm_spe_pmu;
sper->itr.pmu = arm_spe_pmu;
sper->itr.snapshot_start = arm_spe_snapshot_start;
sper->itr.snapshot_finish = arm_spe_snapshot_finish;
sper->itr.find_snapshot = arm_spe_find_snapshot;
sper->itr.parse_snapshot_options = arm_spe_parse_snapshot_options;
sper->itr.recording_options = arm_spe_recording_options;
sper->itr.info_priv_size = arm_spe_info_priv_size;
sper->itr.info_fill = arm_spe_info_fill;
sper->itr.free = arm_spe_recording_free;
sper->itr.reference = arm_spe_reference;
sper->itr.read_finish = auxtrace_record__read_finish;
sper->itr.alignment = 0;
*err = 0;
return &sper->itr;
}
void
arm_spe_pmu_default_config(const struct perf_pmu *arm_spe_pmu, struct perf_event_attr *attr)
{
attr->sample_period = arm_spe_pmu__sample_period(arm_spe_pmu);
}