// SPDX-License-Identifier: GPL-2.0-only
/*
* intel-bts.c: Intel Processor Trace support
* Copyright (c) 2013-2015, Intel Corporation.
*/
#include <errno.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/log2.h>
#include <linux/zalloc.h>
#include "../../../util/cpumap.h"
#include "../../../util/event.h"
#include "../../../util/evsel.h"
#include "../../../util/evlist.h"
#include "../../../util/mmap.h"
#include "../../../util/session.h"
#include "../../../util/pmus.h"
#include "../../../util/debug.h"
#include "../../../util/record.h"
#include "../../../util/tsc.h"
#include "../../../util/auxtrace.h"
#include "../../../util/intel-bts.h"
#include <internal/lib.h> // page_size
#define KiB(x) ((x) * 1024)
#define MiB(x) ((x) * 1024 * 1024)
#define KiB_MASK(x) (KiB(x) - 1)
#define MiB_MASK(x) (MiB(x) - 1)
struct intel_bts_snapshot_ref {
void *ref_buf;
size_t ref_offset;
bool wrapped;
};
struct intel_bts_recording {
struct auxtrace_record itr;
struct perf_pmu *intel_bts_pmu;
struct evlist *evlist;
bool snapshot_mode;
size_t snapshot_size;
int snapshot_ref_cnt;
struct intel_bts_snapshot_ref *snapshot_refs;
};
struct branch {
u64 from;
u64 to;
u64 misc;
};
static size_t
intel_bts_info_priv_size(struct auxtrace_record *itr __maybe_unused,
struct evlist *evlist __maybe_unused)
{
return INTEL_BTS_AUXTRACE_PRIV_SIZE;
}
static int intel_bts_info_fill(struct auxtrace_record *itr,
struct perf_session *session,
struct perf_record_auxtrace_info *auxtrace_info,
size_t priv_size)
{
struct intel_bts_recording *btsr =
container_of(itr, struct intel_bts_recording, itr);
struct perf_pmu *intel_bts_pmu = btsr->intel_bts_pmu;
struct perf_event_mmap_page *pc;
struct perf_tsc_conversion tc = { .time_mult = 0, };
bool cap_user_time_zero = false;
int err;
if (priv_size != INTEL_BTS_AUXTRACE_PRIV_SIZE)
return -EINVAL;
if (!session->evlist->core.nr_mmaps)
return -EINVAL;
pc = session->evlist->mmap[0].core.base;
if (pc) {
err = perf_read_tsc_conversion(pc, &tc);
if (err) {
if (err != -EOPNOTSUPP)
return err;
} else {
cap_user_time_zero = tc.time_mult != 0;
}
if (!cap_user_time_zero)
ui__warning("Intel BTS: TSC not available\n");
}
auxtrace_info->type = PERF_AUXTRACE_INTEL_BTS;
auxtrace_info->priv[INTEL_BTS_PMU_TYPE] = intel_bts_pmu->type;
auxtrace_info->priv[INTEL_BTS_TIME_SHIFT] = tc.time_shift;
auxtrace_info->priv[INTEL_BTS_TIME_MULT] = tc.time_mult;
auxtrace_info->priv[INTEL_BTS_TIME_ZERO] = tc.time_zero;
auxtrace_info->priv[INTEL_BTS_CAP_USER_TIME_ZERO] = cap_user_time_zero;
auxtrace_info->priv[INTEL_BTS_SNAPSHOT_MODE] = btsr->snapshot_mode;
return 0;
}
static int intel_bts_recording_options(struct auxtrace_record *itr,
struct evlist *evlist,
struct record_opts *opts)
{
struct intel_bts_recording *btsr =
container_of(itr, struct intel_bts_recording, itr);
struct perf_pmu *intel_bts_pmu = btsr->intel_bts_pmu;
struct evsel *evsel, *intel_bts_evsel = NULL;
const struct perf_cpu_map *cpus = evlist->core.user_requested_cpus;
bool privileged = perf_event_paranoid_check(-1);
if (opts->auxtrace_sample_mode) {
pr_err("Intel BTS does not support AUX area sampling\n");
return -EINVAL;
}
btsr->evlist = evlist;
btsr->snapshot_mode = opts->auxtrace_snapshot_mode;
evlist__for_each_entry(evlist, evsel) {
if (evsel->core.attr.type == intel_bts_pmu->type) {
if (intel_bts_evsel) {
pr_err("There may be only one " INTEL_BTS_PMU_NAME " event\n");
return -EINVAL;
}
evsel->core.attr.freq = 0;
evsel->core.attr.sample_period = 1;
evsel->needs_auxtrace_mmap = true;
intel_bts_evsel = evsel;
opts->full_auxtrace = true;
}
}
if (opts->auxtrace_snapshot_mode && !opts->full_auxtrace) {
pr_err("Snapshot mode (-S option) requires " INTEL_BTS_PMU_NAME " PMU event (-e " INTEL_BTS_PMU_NAME ")\n");
return -EINVAL;
}
if (!opts->full_auxtrace)
return 0;
if (opts->full_auxtrace && !perf_cpu_map__is_any_cpu_or_is_empty(cpus)) {
pr_err(INTEL_BTS_PMU_NAME " does not support per-cpu recording\n");
return -EINVAL;
}
/* Set default sizes for snapshot mode */
if (opts->auxtrace_snapshot_mode) {
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;
}
if (!opts->auxtrace_snapshot_size)
opts->auxtrace_snapshot_size =
opts->auxtrace_mmap_pages * (size_t)page_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);
}
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;
}
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;
}
pr_debug2("Intel BTS snapshot size: %zu\n",
opts->auxtrace_snapshot_size);
}
/* Set default sizes for full trace mode */
if (opts->full_auxtrace && !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;
if (opts->auxtrace_snapshot_mode)
min_sz = KiB(4);
else
min_sz = KiB(8);
if (sz < min_sz || !is_power_of_2(sz)) {
pr_err("Invalid mmap size for Intel BTS: must be at least %zuKiB and a power of 2\n",
min_sz / 1024);
return -EINVAL;
}
}
if (intel_bts_evsel) {
/*
* To obtain the auxtrace buffer file descriptor, the auxtrace event
* must come first.
*/
evlist__to_front(evlist, intel_bts_evsel);
/*
* In the case of per-cpu mmaps, we need the CPU on the
* AUX event.
*/
if (!perf_cpu_map__is_any_cpu_or_is_empty(cpus))
evsel__set_sample_bit(intel_bts_evsel, CPU);
}
/* Add dummy event to keep tracking */
if (opts->full_auxtrace) {
struct evsel *tracking_evsel;
int err;
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;
}
return 0;
}
static int intel_bts_parse_snapshot_options(struct auxtrace_record *itr,
struct record_opts *opts,
const char *str)
{
struct intel_bts_recording *btsr =
container_of(itr, struct intel_bts_recording, itr);
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;
btsr->snapshot_size = snapshot_size;
return 0;
}
static u64 intel_bts_reference(struct auxtrace_record *itr __maybe_unused)
{
return rdtsc();
}
static int intel_bts_alloc_snapshot_refs(struct intel_bts_recording *btsr,
int idx)
{
const size_t sz = sizeof(struct intel_bts_snapshot_ref);
int cnt = btsr->snapshot_ref_cnt, new_cnt = cnt * 2;
struct intel_bts_snapshot_ref *refs;
if (!new_cnt)
new_cnt = 16;
while (new_cnt <= idx)
new_cnt *= 2;
refs = calloc(new_cnt, sz);
if (!refs)
return -ENOMEM;
memcpy(refs, btsr->snapshot_refs, cnt * sz);
btsr->snapshot_refs = refs;
btsr->snapshot_ref_cnt = new_cnt;
return 0;
}
static void intel_bts_free_snapshot_refs(struct intel_bts_recording *btsr)
{
int i;
for (i = 0; i < btsr->snapshot_ref_cnt; i++)
zfree(&btsr->snapshot_refs[i].ref_buf);
zfree(&btsr->snapshot_refs);
}
static void intel_bts_recording_free(struct auxtrace_record *itr)
{
struct intel_bts_recording *btsr =
container_of(itr, struct intel_bts_recording, itr);
intel_bts_free_snapshot_refs(btsr);
free(btsr);
}
static int intel_bts_snapshot_start(struct auxtrace_record *itr)
{
struct intel_bts_recording *btsr =
container_of(itr, struct intel_bts_recording, itr);
struct evsel *evsel;
evlist__for_each_entry(btsr->evlist, evsel) {
if (evsel->core.attr.type == btsr->intel_bts_pmu->type)
return evsel__disable(evsel);
}
return -EINVAL;
}
static int intel_bts_snapshot_finish(struct auxtrace_record *itr)
{
struct intel_bts_recording *btsr =
container_of(itr, struct intel_bts_recording, itr);
struct evsel *evsel;
evlist__for_each_entry(btsr->evlist, evsel) {
if (evsel->core.attr.type == btsr->intel_bts_pmu->type)
return evsel__enable(evsel);
}
return -EINVAL;
}
static bool intel_bts_first_wrap(u64 *data, size_t buf_size)
{
int i, a, b;
b = buf_size >> 3;
a = b - 512;
if (a < 0)
a = 0;
for (i = a; i < b; i++) {
if (data[i])
return true;
}
return false;
}
static int intel_bts_find_snapshot(struct auxtrace_record *itr, int idx,
struct auxtrace_mmap *mm, unsigned char *data,
u64 *head, u64 *old)
{
struct intel_bts_recording *btsr =
container_of(itr, struct intel_bts_recording, itr);
bool wrapped;
int err;
pr_debug3("%s: mmap index %d old head %zu new head %zu\n",
__func__, idx, (size_t)*old, (size_t)*head);
if (idx >= btsr->snapshot_ref_cnt) {
err = intel_bts_alloc_snapshot_refs(btsr, idx);
if (err)
goto out_err;
}
wrapped = btsr->snapshot_refs[idx].wrapped;
if (!wrapped && intel_bts_first_wrap((u64 *)data, mm->len)) {
btsr->snapshot_refs[idx].wrapped = true;
wrapped = true;
}
/*
* In full trace mode 'head' continually increases. However in snapshot
* mode 'head' is an offset within the buffer. Here 'old' and 'head'
* are adjusted to match the full trace case which expects that 'old' is
* always less than 'head'.
*/
if (wrapped) {
*old = *head;
*head += mm->len;
} else {
if (mm->mask)
*old &= mm->mask;
else
*old %= mm->len;
if (*old > *head)
*head += mm->len;
}
pr_debug3("%s: wrap-around %sdetected, adjusted old head %zu adjusted new head %zu\n",
__func__, wrapped ? "" : "not ", (size_t)*old, (size_t)*head);
return 0;
out_err:
pr_err("%s: failed, error %d\n", __func__, err);
return err;
}
struct auxtrace_record *intel_bts_recording_init(int *err)
{
struct perf_pmu *intel_bts_pmu = perf_pmus__find(INTEL_BTS_PMU_NAME);
struct intel_bts_recording *btsr;
if (!intel_bts_pmu)
return NULL;
if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) {
*err = -errno;
return NULL;
}
btsr = zalloc(sizeof(struct intel_bts_recording));
if (!btsr) {
*err = -ENOMEM;
return NULL;
}
btsr->intel_bts_pmu = intel_bts_pmu;
btsr->itr.recording_options = intel_bts_recording_options;
btsr->itr.info_priv_size = intel_bts_info_priv_size;
btsr->itr.info_fill = intel_bts_info_fill;
btsr->itr.free = intel_bts_recording_free;
btsr->itr.snapshot_start = intel_bts_snapshot_start;
btsr->itr.snapshot_finish = intel_bts_snapshot_finish;
btsr->itr.find_snapshot = intel_bts_find_snapshot;
btsr->itr.parse_snapshot_options = intel_bts_parse_snapshot_options;
btsr->itr.reference = intel_bts_reference;
btsr->itr.read_finish = auxtrace_record__read_finish;
btsr->itr.alignment = sizeof(struct branch);
return &btsr->itr;
}
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