diff options
Diffstat (limited to 'tools/perf/arch/arm64/util/arm-spe.c')
-rw-r--r-- | tools/perf/arch/arm64/util/arm-spe.c | 523 |
1 files changed, 523 insertions, 0 deletions
diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c new file mode 100644 index 0000000000..9cc3d6dcb8 --- /dev/null +++ b/tools/perf/arch/arm64/util/arm-spe.c @@ -0,0 +1,523 @@ +// 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 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->default_config->sample_period; + 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__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__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; +} + +struct perf_event_attr +*arm_spe_pmu_default_config(struct perf_pmu *arm_spe_pmu) +{ + struct perf_event_attr *attr; + + attr = zalloc(sizeof(struct perf_event_attr)); + if (!attr) { + pr_err("arm_spe default config cannot allocate a perf_event_attr\n"); + return NULL; + } + + /* + * 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", + &attr->sample_period) != 1) { + pr_debug("arm_spe driver doesn't advertise a min. interval. Using 4096\n"); + attr->sample_period = 4096; + } + + arm_spe_pmu->selectable = true; + arm_spe_pmu->is_uncore = false; + + return attr; +} |