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OpenCloudOS-Kernel/tools/perf/arch/x86/util/intel-pt.c

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/*
* intel_pt.c: Intel Processor Trace support
* Copyright (c) 2013-2015, Intel Corporation.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
*/
#include <stdbool.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/log2.h>
#include <cpuid.h>
#include "../../perf.h"
#include "../../util/session.h"
#include "../../util/event.h"
#include "../../util/evlist.h"
#include "../../util/evsel.h"
#include "../../util/cpumap.h"
#include <subcmd/parse-options.h>
#include "../../util/parse-events.h"
#include "../../util/pmu.h"
#include "../../util/debug.h"
#include "../../util/auxtrace.h"
#include "../../util/tsc.h"
#include "../../util/intel-pt.h"
#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)
#define INTEL_PT_DEFAULT_SAMPLE_SIZE KiB(4)
#define INTEL_PT_MAX_SAMPLE_SIZE KiB(60)
#define INTEL_PT_PSB_PERIOD_NEAR 256
struct intel_pt_snapshot_ref {
void *ref_buf;
size_t ref_offset;
bool wrapped;
};
struct intel_pt_recording {
struct auxtrace_record itr;
struct perf_pmu *intel_pt_pmu;
int have_sched_switch;
struct perf_evlist *evlist;
bool snapshot_mode;
bool snapshot_init_done;
size_t snapshot_size;
size_t snapshot_ref_buf_size;
int snapshot_ref_cnt;
struct intel_pt_snapshot_ref *snapshot_refs;
};
static int intel_pt_parse_terms_with_default(struct list_head *formats,
const char *str,
u64 *config)
{
struct list_head *terms;
struct perf_event_attr attr = { .size = 0, };
int err;
terms = malloc(sizeof(struct list_head));
if (!terms)
return -ENOMEM;
INIT_LIST_HEAD(terms);
err = parse_events_terms(terms, str);
if (err)
goto out_free;
attr.config = *config;
err = perf_pmu__config_terms(formats, &attr, terms, true, NULL);
if (err)
goto out_free;
*config = attr.config;
out_free:
parse_events_terms__delete(terms);
return err;
}
static int intel_pt_parse_terms(struct list_head *formats, const char *str,
u64 *config)
{
*config = 0;
return intel_pt_parse_terms_with_default(formats, str, config);
}
static u64 intel_pt_masked_bits(u64 mask, u64 bits)
{
const u64 top_bit = 1ULL << 63;
u64 res = 0;
int i;
for (i = 0; i < 64; i++) {
if (mask & top_bit) {
res <<= 1;
if (bits & top_bit)
res |= 1;
}
mask <<= 1;
bits <<= 1;
}
return res;
}
static int intel_pt_read_config(struct perf_pmu *intel_pt_pmu, const char *str,
struct perf_evlist *evlist, u64 *res)
{
struct perf_evsel *evsel;
u64 mask;
*res = 0;
mask = perf_pmu__format_bits(&intel_pt_pmu->format, str);
if (!mask)
return -EINVAL;
evlist__for_each(evlist, evsel) {
if (evsel->attr.type == intel_pt_pmu->type) {
*res = intel_pt_masked_bits(mask, evsel->attr.config);
return 0;
}
}
return -EINVAL;
}
static size_t intel_pt_psb_period(struct perf_pmu *intel_pt_pmu,
struct perf_evlist *evlist)
{
u64 val;
int err, topa_multiple_entries;
size_t psb_period;
if (perf_pmu__scan_file(intel_pt_pmu, "caps/topa_multiple_entries",
"%d", &topa_multiple_entries) != 1)
topa_multiple_entries = 0;
/*
* Use caps/topa_multiple_entries to indicate early hardware that had
* extra frequent PSBs.
*/
if (!topa_multiple_entries) {
psb_period = 256;
goto out;
}
err = intel_pt_read_config(intel_pt_pmu, "psb_period", evlist, &val);
if (err)
val = 0;
psb_period = 1 << (val + 11);
out:
pr_debug2("%s psb_period %zu\n", intel_pt_pmu->name, psb_period);
return psb_period;
}
static int intel_pt_pick_bit(int bits, int target)
{
int pos, pick = -1;
for (pos = 0; bits; bits >>= 1, pos++) {
if (bits & 1) {
if (pos <= target || pick < 0)
pick = pos;
if (pos >= target)
break;
}
}
return pick;
}
static u64 intel_pt_default_config(struct perf_pmu *intel_pt_pmu)
{
char buf[256];
int mtc, mtc_periods = 0, mtc_period;
int psb_cyc, psb_periods, psb_period;
int pos = 0;
u64 config;
pos += scnprintf(buf + pos, sizeof(buf) - pos, "tsc");
if (perf_pmu__scan_file(intel_pt_pmu, "caps/mtc", "%d",
&mtc) != 1)
mtc = 1;
if (mtc) {
if (perf_pmu__scan_file(intel_pt_pmu, "caps/mtc_periods", "%x",
&mtc_periods) != 1)
mtc_periods = 0;
if (mtc_periods) {
mtc_period = intel_pt_pick_bit(mtc_periods, 3);
pos += scnprintf(buf + pos, sizeof(buf) - pos,
",mtc,mtc_period=%d", mtc_period);
}
}
if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_cyc", "%d",
&psb_cyc) != 1)
psb_cyc = 1;
if (psb_cyc && mtc_periods) {
if (perf_pmu__scan_file(intel_pt_pmu, "caps/psb_periods", "%x",
&psb_periods) != 1)
psb_periods = 0;
if (psb_periods) {
psb_period = intel_pt_pick_bit(psb_periods, 3);
pos += scnprintf(buf + pos, sizeof(buf) - pos,
",psb_period=%d", psb_period);
}
}
pr_debug2("%s default config: %s\n", intel_pt_pmu->name, buf);
intel_pt_parse_terms(&intel_pt_pmu->format, buf, &config);
return config;
}
static int intel_pt_parse_snapshot_options(struct auxtrace_record *itr,
struct record_opts *opts,
const char *str)
{
struct intel_pt_recording *ptr =
container_of(itr, struct intel_pt_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;
ptr->snapshot_size = snapshot_size;
return 0;
}
struct perf_event_attr *
intel_pt_pmu_default_config(struct perf_pmu *intel_pt_pmu)
{
struct perf_event_attr *attr;
attr = zalloc(sizeof(struct perf_event_attr));
if (!attr)
return NULL;
attr->config = intel_pt_default_config(intel_pt_pmu);
intel_pt_pmu->selectable = true;
return attr;
}
static size_t
intel_pt_info_priv_size(struct auxtrace_record *itr __maybe_unused,
struct perf_evlist *evlist __maybe_unused)
{
return INTEL_PT_AUXTRACE_PRIV_SIZE;
}
static void intel_pt_tsc_ctc_ratio(u32 *n, u32 *d)
{
unsigned int eax = 0, ebx = 0, ecx = 0, edx = 0;
__get_cpuid(0x15, &eax, &ebx, &ecx, &edx);
*n = ebx;
*d = eax;
}
static int intel_pt_info_fill(struct auxtrace_record *itr,
struct perf_session *session,
struct auxtrace_info_event *auxtrace_info,
size_t priv_size)
{
struct intel_pt_recording *ptr =
container_of(itr, struct intel_pt_recording, itr);
struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
struct perf_event_mmap_page *pc;
struct perf_tsc_conversion tc = { .time_mult = 0, };
bool cap_user_time_zero = false, per_cpu_mmaps;
u64 tsc_bit, mtc_bit, mtc_freq_bits, cyc_bit, noretcomp_bit;
u32 tsc_ctc_ratio_n, tsc_ctc_ratio_d;
int err;
if (priv_size != INTEL_PT_AUXTRACE_PRIV_SIZE)
return -EINVAL;
intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &tsc_bit);
intel_pt_parse_terms(&intel_pt_pmu->format, "noretcomp",
&noretcomp_bit);
intel_pt_parse_terms(&intel_pt_pmu->format, "mtc", &mtc_bit);
mtc_freq_bits = perf_pmu__format_bits(&intel_pt_pmu->format,
"mtc_period");
intel_pt_parse_terms(&intel_pt_pmu->format, "cyc", &cyc_bit);
intel_pt_tsc_ctc_ratio(&tsc_ctc_ratio_n, &tsc_ctc_ratio_d);
if (!session->evlist->nr_mmaps)
return -EINVAL;
pc = session->evlist->mmap[0].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 Processor Trace: TSC not available\n");
}
per_cpu_mmaps = !cpu_map__empty(session->evlist->cpus);
auxtrace_info->type = PERF_AUXTRACE_INTEL_PT;
auxtrace_info->priv[INTEL_PT_PMU_TYPE] = intel_pt_pmu->type;
auxtrace_info->priv[INTEL_PT_TIME_SHIFT] = tc.time_shift;
auxtrace_info->priv[INTEL_PT_TIME_MULT] = tc.time_mult;
auxtrace_info->priv[INTEL_PT_TIME_ZERO] = tc.time_zero;
auxtrace_info->priv[INTEL_PT_CAP_USER_TIME_ZERO] = cap_user_time_zero;
auxtrace_info->priv[INTEL_PT_TSC_BIT] = tsc_bit;
auxtrace_info->priv[INTEL_PT_NORETCOMP_BIT] = noretcomp_bit;
auxtrace_info->priv[INTEL_PT_HAVE_SCHED_SWITCH] = ptr->have_sched_switch;
auxtrace_info->priv[INTEL_PT_SNAPSHOT_MODE] = ptr->snapshot_mode;
auxtrace_info->priv[INTEL_PT_PER_CPU_MMAPS] = per_cpu_mmaps;
auxtrace_info->priv[INTEL_PT_MTC_BIT] = mtc_bit;
auxtrace_info->priv[INTEL_PT_MTC_FREQ_BITS] = mtc_freq_bits;
auxtrace_info->priv[INTEL_PT_TSC_CTC_N] = tsc_ctc_ratio_n;
auxtrace_info->priv[INTEL_PT_TSC_CTC_D] = tsc_ctc_ratio_d;
auxtrace_info->priv[INTEL_PT_CYC_BIT] = cyc_bit;
return 0;
}
static int intel_pt_track_switches(struct perf_evlist *evlist)
{
const char *sched_switch = "sched:sched_switch";
struct perf_evsel *evsel;
int err;
if (!perf_evlist__can_select_event(evlist, sched_switch))
return -EPERM;
err = parse_events(evlist, sched_switch, NULL);
if (err) {
pr_debug2("%s: failed to parse %s, error %d\n",
__func__, sched_switch, err);
return err;
}
evsel = perf_evlist__last(evlist);
perf_evsel__set_sample_bit(evsel, CPU);
perf_evsel__set_sample_bit(evsel, TIME);
evsel->system_wide = true;
evsel->no_aux_samples = true;
evsel->immediate = true;
return 0;
}
static void intel_pt_valid_str(char *str, size_t len, u64 valid)
{
unsigned int val, last = 0, state = 1;
int p = 0;
str[0] = '\0';
for (val = 0; val <= 64; val++, valid >>= 1) {
if (valid & 1) {
last = val;
switch (state) {
case 0:
p += scnprintf(str + p, len - p, ",");
/* Fall through */
case 1:
p += scnprintf(str + p, len - p, "%u", val);
state = 2;
break;
case 2:
state = 3;
break;
case 3:
state = 4;
break;
default:
break;
}
} else {
switch (state) {
case 3:
p += scnprintf(str + p, len - p, ",%u", last);
state = 0;
break;
case 4:
p += scnprintf(str + p, len - p, "-%u", last);
state = 0;
break;
default:
break;
}
if (state != 1)
state = 0;
}
}
}
static int intel_pt_val_config_term(struct perf_pmu *intel_pt_pmu,
const char *caps, const char *name,
const char *supported, u64 config)
{
char valid_str[256];
unsigned int shift;
unsigned long long valid;
u64 bits;
int ok;
if (perf_pmu__scan_file(intel_pt_pmu, caps, "%llx", &valid) != 1)
valid = 0;
if (supported &&
perf_pmu__scan_file(intel_pt_pmu, supported, "%d", &ok) == 1 && !ok)
valid = 0;
valid |= 1;
bits = perf_pmu__format_bits(&intel_pt_pmu->format, name);
config &= bits;
for (shift = 0; bits && !(bits & 1); shift++)
bits >>= 1;
config >>= shift;
if (config > 63)
goto out_err;
if (valid & (1 << config))
return 0;
out_err:
intel_pt_valid_str(valid_str, sizeof(valid_str), valid);
pr_err("Invalid %s for %s. Valid values are: %s\n",
name, INTEL_PT_PMU_NAME, valid_str);
return -EINVAL;
}
static int intel_pt_validate_config(struct perf_pmu *intel_pt_pmu,
struct perf_evsel *evsel)
{
int err;
if (!evsel)
return 0;
err = intel_pt_val_config_term(intel_pt_pmu, "caps/cycle_thresholds",
"cyc_thresh", "caps/psb_cyc",
evsel->attr.config);
if (err)
return err;
err = intel_pt_val_config_term(intel_pt_pmu, "caps/mtc_periods",
"mtc_period", "caps/mtc",
evsel->attr.config);
if (err)
return err;
return intel_pt_val_config_term(intel_pt_pmu, "caps/psb_periods",
"psb_period", "caps/psb_cyc",
evsel->attr.config);
}
static int intel_pt_recording_options(struct auxtrace_record *itr,
struct perf_evlist *evlist,
struct record_opts *opts)
{
struct intel_pt_recording *ptr =
container_of(itr, struct intel_pt_recording, itr);
struct perf_pmu *intel_pt_pmu = ptr->intel_pt_pmu;
bool have_timing_info;
struct perf_evsel *evsel, *intel_pt_evsel = NULL;
const struct cpu_map *cpus = evlist->cpus;
bool privileged = geteuid() == 0 || perf_event_paranoid() < 0;
u64 tsc_bit;
int err;
ptr->evlist = evlist;
ptr->snapshot_mode = opts->auxtrace_snapshot_mode;
evlist__for_each(evlist, evsel) {
if (evsel->attr.type == intel_pt_pmu->type) {
if (intel_pt_evsel) {
pr_err("There may be only one " INTEL_PT_PMU_NAME " event\n");
return -EINVAL;
}
evsel->attr.freq = 0;
evsel->attr.sample_period = 1;
intel_pt_evsel = evsel;
opts->full_auxtrace = true;
}
}
if (opts->auxtrace_snapshot_mode && !opts->full_auxtrace) {
pr_err("Snapshot mode (-S option) requires " INTEL_PT_PMU_NAME " PMU event (-e " INTEL_PT_PMU_NAME ")\n");
return -EINVAL;
}
if (opts->use_clockid) {
pr_err("Cannot use clockid (-k option) with " INTEL_PT_PMU_NAME "\n");
return -EINVAL;
}
if (!opts->full_auxtrace)
return 0;
err = intel_pt_validate_config(intel_pt_pmu, intel_pt_evsel);
if (err)
return err;
/* Set default sizes for snapshot mode */
if (opts->auxtrace_snapshot_mode) {
size_t psb_period = intel_pt_psb_period(intel_pt_pmu, evlist);
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 PT snapshot size: %zu\n",
opts->auxtrace_snapshot_size);
if (psb_period &&
opts->auxtrace_snapshot_size <= psb_period +
INTEL_PT_PSB_PERIOD_NEAR)
ui__warning("Intel PT snapshot size (%zu) may be too small for PSB period (%zu)\n",
opts->auxtrace_snapshot_size, psb_period);
}
/* 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 Processor Trace: must be at least %zuKiB and a power of 2\n",
min_sz / 1024);
return -EINVAL;
}
}
intel_pt_parse_terms(&intel_pt_pmu->format, "tsc", &tsc_bit);
if (opts->full_auxtrace && (intel_pt_evsel->attr.config & tsc_bit))
have_timing_info = true;
else
have_timing_info = false;
/*
* Per-cpu recording needs sched_switch events to distinguish different
* threads.
*/
if (have_timing_info && !cpu_map__empty(cpus)) {
if (perf_can_record_switch_events()) {
bool cpu_wide = !target__none(&opts->target) &&
!target__has_task(&opts->target);
if (!cpu_wide && perf_can_record_cpu_wide()) {
struct perf_evsel *switch_evsel;
err = parse_events(evlist, "dummy:u", NULL);
if (err)
return err;
switch_evsel = perf_evlist__last(evlist);
switch_evsel->attr.freq = 0;
switch_evsel->attr.sample_period = 1;
switch_evsel->attr.context_switch = 1;
switch_evsel->system_wide = true;
switch_evsel->no_aux_samples = true;
switch_evsel->immediate = true;
perf_evsel__set_sample_bit(switch_evsel, TID);
perf_evsel__set_sample_bit(switch_evsel, TIME);
perf_evsel__set_sample_bit(switch_evsel, CPU);
opts->record_switch_events = false;
ptr->have_sched_switch = 3;
} else {
opts->record_switch_events = true;
if (cpu_wide)
ptr->have_sched_switch = 3;
else
ptr->have_sched_switch = 2;
}
} else {
err = intel_pt_track_switches(evlist);
if (err == -EPERM)
pr_debug2("Unable to select sched:sched_switch\n");
else if (err)
return err;
else
ptr->have_sched_switch = 1;
}
}
if (intel_pt_evsel) {
/*
* To obtain the auxtrace buffer file descriptor, the auxtrace
* event must come first.
*/
perf_evlist__to_front(evlist, intel_pt_evsel);
/*
* In the case of per-cpu mmaps, we need the CPU on the
* AUX event.
*/
if (!cpu_map__empty(cpus))
perf_evsel__set_sample_bit(intel_pt_evsel, CPU);
}
/* Add dummy event to keep tracking */
if (opts->full_auxtrace) {
struct perf_evsel *tracking_evsel;
err = parse_events(evlist, "dummy:u", NULL);
if (err)
return err;
tracking_evsel = perf_evlist__last(evlist);
perf_evlist__set_tracking_event(evlist, tracking_evsel);
tracking_evsel->attr.freq = 0;
tracking_evsel->attr.sample_period = 1;
/* In per-cpu case, always need the time of mmap events etc */
if (!cpu_map__empty(cpus)) {
perf_evsel__set_sample_bit(tracking_evsel, TIME);
/* And the CPU for switch events */
perf_evsel__set_sample_bit(tracking_evsel, CPU);
}
}
/*
* Warn the user when we do not have enough information to decode i.e.
* per-cpu with no sched_switch (except workload-only).
*/
if (!ptr->have_sched_switch && !cpu_map__empty(cpus) &&
!target__none(&opts->target))
ui__warning("Intel Processor Trace decoding will not be possible except for kernel tracing!\n");
return 0;
}
static int intel_pt_snapshot_start(struct auxtrace_record *itr)
{
struct intel_pt_recording *ptr =
container_of(itr, struct intel_pt_recording, itr);
struct perf_evsel *evsel;
evlist__for_each(ptr->evlist, evsel) {
if (evsel->attr.type == ptr->intel_pt_pmu->type)
return perf_evsel__disable(evsel);
}
return -EINVAL;
}
static int intel_pt_snapshot_finish(struct auxtrace_record *itr)
{
struct intel_pt_recording *ptr =
container_of(itr, struct intel_pt_recording, itr);
struct perf_evsel *evsel;
evlist__for_each(ptr->evlist, evsel) {
if (evsel->attr.type == ptr->intel_pt_pmu->type)
return perf_evsel__enable(evsel);
}
return -EINVAL;
}
static int intel_pt_alloc_snapshot_refs(struct intel_pt_recording *ptr, int idx)
{
const size_t sz = sizeof(struct intel_pt_snapshot_ref);
int cnt = ptr->snapshot_ref_cnt, new_cnt = cnt * 2;
struct intel_pt_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, ptr->snapshot_refs, cnt * sz);
ptr->snapshot_refs = refs;
ptr->snapshot_ref_cnt = new_cnt;
return 0;
}
static void intel_pt_free_snapshot_refs(struct intel_pt_recording *ptr)
{
int i;
for (i = 0; i < ptr->snapshot_ref_cnt; i++)
zfree(&ptr->snapshot_refs[i].ref_buf);
zfree(&ptr->snapshot_refs);
}
static void intel_pt_recording_free(struct auxtrace_record *itr)
{
struct intel_pt_recording *ptr =
container_of(itr, struct intel_pt_recording, itr);
intel_pt_free_snapshot_refs(ptr);
free(ptr);
}
static int intel_pt_alloc_snapshot_ref(struct intel_pt_recording *ptr, int idx,
size_t snapshot_buf_size)
{
size_t ref_buf_size = ptr->snapshot_ref_buf_size;
void *ref_buf;
ref_buf = zalloc(ref_buf_size);
if (!ref_buf)
return -ENOMEM;
ptr->snapshot_refs[idx].ref_buf = ref_buf;
ptr->snapshot_refs[idx].ref_offset = snapshot_buf_size - ref_buf_size;
return 0;
}
static size_t intel_pt_snapshot_ref_buf_size(struct intel_pt_recording *ptr,
size_t snapshot_buf_size)
{
const size_t max_size = 256 * 1024;
size_t buf_size = 0, psb_period;
if (ptr->snapshot_size <= 64 * 1024)
return 0;
psb_period = intel_pt_psb_period(ptr->intel_pt_pmu, ptr->evlist);
if (psb_period)
buf_size = psb_period * 2;
if (!buf_size || buf_size > max_size)
buf_size = max_size;
if (buf_size >= snapshot_buf_size)
return 0;
if (buf_size >= ptr->snapshot_size / 2)
return 0;
return buf_size;
}
static int intel_pt_snapshot_init(struct intel_pt_recording *ptr,
size_t snapshot_buf_size)
{
if (ptr->snapshot_init_done)
return 0;
ptr->snapshot_init_done = true;
ptr->snapshot_ref_buf_size = intel_pt_snapshot_ref_buf_size(ptr,
snapshot_buf_size);
return 0;
}
/**
* intel_pt_compare_buffers - compare bytes in a buffer to a circular buffer.
* @buf1: first buffer
* @compare_size: number of bytes to compare
* @buf2: second buffer (a circular buffer)
* @offs2: offset in second buffer
* @buf2_size: size of second buffer
*
* The comparison allows for the possibility that the bytes to compare in the
* circular buffer are not contiguous. It is assumed that @compare_size <=
* @buf2_size. This function returns %false if the bytes are identical, %true
* otherwise.
*/
static bool intel_pt_compare_buffers(void *buf1, size_t compare_size,
void *buf2, size_t offs2, size_t buf2_size)
{
size_t end2 = offs2 + compare_size, part_size;
if (end2 <= buf2_size)
return memcmp(buf1, buf2 + offs2, compare_size);
part_size = end2 - buf2_size;
if (memcmp(buf1, buf2 + offs2, part_size))
return true;
compare_size -= part_size;
return memcmp(buf1 + part_size, buf2, compare_size);
}
static bool intel_pt_compare_ref(void *ref_buf, size_t ref_offset,
size_t ref_size, size_t buf_size,
void *data, size_t head)
{
size_t ref_end = ref_offset + ref_size;
if (ref_end > buf_size) {
if (head > ref_offset || head < ref_end - buf_size)
return true;
} else if (head > ref_offset && head < ref_end) {
return true;
}
return intel_pt_compare_buffers(ref_buf, ref_size, data, ref_offset,
buf_size);
}
static void intel_pt_copy_ref(void *ref_buf, size_t ref_size, size_t buf_size,
void *data, size_t head)
{
if (head >= ref_size) {
memcpy(ref_buf, data + head - ref_size, ref_size);
} else {
memcpy(ref_buf, data, head);
ref_size -= head;
memcpy(ref_buf + head, data + buf_size - ref_size, ref_size);
}
}
static bool intel_pt_wrapped(struct intel_pt_recording *ptr, int idx,
struct auxtrace_mmap *mm, unsigned char *data,
u64 head)
{
struct intel_pt_snapshot_ref *ref = &ptr->snapshot_refs[idx];
bool wrapped;
wrapped = intel_pt_compare_ref(ref->ref_buf, ref->ref_offset,
ptr->snapshot_ref_buf_size, mm->len,
data, head);
intel_pt_copy_ref(ref->ref_buf, ptr->snapshot_ref_buf_size, mm->len,
data, head);
return wrapped;
}
static bool intel_pt_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_pt_find_snapshot(struct auxtrace_record *itr, int idx,
struct auxtrace_mmap *mm, unsigned char *data,
u64 *head, u64 *old)
{
struct intel_pt_recording *ptr =
container_of(itr, struct intel_pt_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);
err = intel_pt_snapshot_init(ptr, mm->len);
if (err)
goto out_err;
if (idx >= ptr->snapshot_ref_cnt) {
err = intel_pt_alloc_snapshot_refs(ptr, idx);
if (err)
goto out_err;
}
if (ptr->snapshot_ref_buf_size) {
if (!ptr->snapshot_refs[idx].ref_buf) {
err = intel_pt_alloc_snapshot_ref(ptr, idx, mm->len);
if (err)
goto out_err;
}
wrapped = intel_pt_wrapped(ptr, idx, mm, data, *head);
} else {
wrapped = ptr->snapshot_refs[idx].wrapped;
if (!wrapped && intel_pt_first_wrap((u64 *)data, mm->len)) {
ptr->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;
}
static u64 intel_pt_reference(struct auxtrace_record *itr __maybe_unused)
{
return rdtsc();
}
static int intel_pt_read_finish(struct auxtrace_record *itr, int idx)
{
struct intel_pt_recording *ptr =
container_of(itr, struct intel_pt_recording, itr);
struct perf_evsel *evsel;
evlist__for_each(ptr->evlist, evsel) {
if (evsel->attr.type == ptr->intel_pt_pmu->type)
return perf_evlist__enable_event_idx(ptr->evlist, evsel,
idx);
}
return -EINVAL;
}
struct auxtrace_record *intel_pt_recording_init(int *err)
{
struct perf_pmu *intel_pt_pmu = perf_pmu__find(INTEL_PT_PMU_NAME);
struct intel_pt_recording *ptr;
if (!intel_pt_pmu)
return NULL;
if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) {
*err = -errno;
return NULL;
}
ptr = zalloc(sizeof(struct intel_pt_recording));
if (!ptr) {
*err = -ENOMEM;
return NULL;
}
ptr->intel_pt_pmu = intel_pt_pmu;
ptr->itr.recording_options = intel_pt_recording_options;
ptr->itr.info_priv_size = intel_pt_info_priv_size;
ptr->itr.info_fill = intel_pt_info_fill;
ptr->itr.free = intel_pt_recording_free;
ptr->itr.snapshot_start = intel_pt_snapshot_start;
ptr->itr.snapshot_finish = intel_pt_snapshot_finish;
ptr->itr.find_snapshot = intel_pt_find_snapshot;
ptr->itr.parse_snapshot_options = intel_pt_parse_snapshot_options;
ptr->itr.reference = intel_pt_reference;
ptr->itr.read_finish = intel_pt_read_finish;
return &ptr->itr;
}
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