2 * intel-bts.c: Intel Processor Trace support
3 * Copyright (c) 2013-2015, Intel Corporation.
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
17 #include <linux/kernel.h>
18 #include <linux/types.h>
19 #include <linux/bitops.h>
20 #include <linux/log2.h>
22 #include "../../util/cpumap.h"
23 #include "../../util/evsel.h"
24 #include "../../util/evlist.h"
25 #include "../../util/session.h"
26 #include "../../util/util.h"
27 #include "../../util/pmu.h"
28 #include "../../util/debug.h"
29 #include "../../util/tsc.h"
30 #include "../../util/auxtrace.h"
31 #include "../../util/intel-bts.h"
33 #define KiB(x) ((x) * 1024)
34 #define MiB(x) ((x) * 1024 * 1024)
35 #define KiB_MASK(x) (KiB(x) - 1)
36 #define MiB_MASK(x) (MiB(x) - 1)
38 struct intel_bts_snapshot_ref {
44 struct intel_bts_recording {
45 struct auxtrace_record itr;
46 struct perf_pmu *intel_bts_pmu;
47 struct perf_evlist *evlist;
51 struct intel_bts_snapshot_ref *snapshot_refs;
61 intel_bts_info_priv_size(struct auxtrace_record *itr __maybe_unused,
62 struct perf_evlist *evlist __maybe_unused)
64 return INTEL_BTS_AUXTRACE_PRIV_SIZE;
67 static int intel_bts_info_fill(struct auxtrace_record *itr,
68 struct perf_session *session,
69 struct auxtrace_info_event *auxtrace_info,
72 struct intel_bts_recording *btsr =
73 container_of(itr, struct intel_bts_recording, itr);
74 struct perf_pmu *intel_bts_pmu = btsr->intel_bts_pmu;
75 struct perf_event_mmap_page *pc;
76 struct perf_tsc_conversion tc = { .time_mult = 0, };
77 bool cap_user_time_zero = false;
80 if (priv_size != INTEL_BTS_AUXTRACE_PRIV_SIZE)
83 if (!session->evlist->nr_mmaps)
86 pc = session->evlist->mmap[0].base;
88 err = perf_read_tsc_conversion(pc, &tc);
90 if (err != -EOPNOTSUPP)
93 cap_user_time_zero = tc.time_mult != 0;
95 if (!cap_user_time_zero)
96 ui__warning("Intel BTS: TSC not available\n");
99 auxtrace_info->type = PERF_AUXTRACE_INTEL_BTS;
100 auxtrace_info->priv[INTEL_BTS_PMU_TYPE] = intel_bts_pmu->type;
101 auxtrace_info->priv[INTEL_BTS_TIME_SHIFT] = tc.time_shift;
102 auxtrace_info->priv[INTEL_BTS_TIME_MULT] = tc.time_mult;
103 auxtrace_info->priv[INTEL_BTS_TIME_ZERO] = tc.time_zero;
104 auxtrace_info->priv[INTEL_BTS_CAP_USER_TIME_ZERO] = cap_user_time_zero;
105 auxtrace_info->priv[INTEL_BTS_SNAPSHOT_MODE] = btsr->snapshot_mode;
110 static int intel_bts_recording_options(struct auxtrace_record *itr,
111 struct perf_evlist *evlist,
112 struct record_opts *opts)
114 struct intel_bts_recording *btsr =
115 container_of(itr, struct intel_bts_recording, itr);
116 struct perf_pmu *intel_bts_pmu = btsr->intel_bts_pmu;
117 struct perf_evsel *evsel, *intel_bts_evsel = NULL;
118 const struct cpu_map *cpus = evlist->cpus;
119 bool privileged = geteuid() == 0 || perf_event_paranoid() < 0;
121 btsr->evlist = evlist;
122 btsr->snapshot_mode = opts->auxtrace_snapshot_mode;
124 evlist__for_each_entry(evlist, evsel) {
125 if (evsel->attr.type == intel_bts_pmu->type) {
126 if (intel_bts_evsel) {
127 pr_err("There may be only one " INTEL_BTS_PMU_NAME " event\n");
130 evsel->attr.freq = 0;
131 evsel->attr.sample_period = 1;
132 intel_bts_evsel = evsel;
133 opts->full_auxtrace = true;
137 if (opts->auxtrace_snapshot_mode && !opts->full_auxtrace) {
138 pr_err("Snapshot mode (-S option) requires " INTEL_BTS_PMU_NAME " PMU event (-e " INTEL_BTS_PMU_NAME ")\n");
142 if (!opts->full_auxtrace)
145 if (opts->full_auxtrace && !cpu_map__empty(cpus)) {
146 pr_err(INTEL_BTS_PMU_NAME " does not support per-cpu recording\n");
150 /* Set default sizes for snapshot mode */
151 if (opts->auxtrace_snapshot_mode) {
152 if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) {
154 opts->auxtrace_mmap_pages = MiB(4) / page_size;
156 opts->auxtrace_mmap_pages = KiB(128) / page_size;
157 if (opts->mmap_pages == UINT_MAX)
158 opts->mmap_pages = KiB(256) / page_size;
160 } else if (!opts->auxtrace_mmap_pages && !privileged &&
161 opts->mmap_pages == UINT_MAX) {
162 opts->mmap_pages = KiB(256) / page_size;
164 if (!opts->auxtrace_snapshot_size)
165 opts->auxtrace_snapshot_size =
166 opts->auxtrace_mmap_pages * (size_t)page_size;
167 if (!opts->auxtrace_mmap_pages) {
168 size_t sz = opts->auxtrace_snapshot_size;
170 sz = round_up(sz, page_size) / page_size;
171 opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
173 if (opts->auxtrace_snapshot_size >
174 opts->auxtrace_mmap_pages * (size_t)page_size) {
175 pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n",
176 opts->auxtrace_snapshot_size,
177 opts->auxtrace_mmap_pages * (size_t)page_size);
180 if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages) {
181 pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n");
184 pr_debug2("Intel BTS snapshot size: %zu\n",
185 opts->auxtrace_snapshot_size);
188 /* Set default sizes for full trace mode */
189 if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
191 opts->auxtrace_mmap_pages = MiB(4) / page_size;
193 opts->auxtrace_mmap_pages = KiB(128) / page_size;
194 if (opts->mmap_pages == UINT_MAX)
195 opts->mmap_pages = KiB(256) / page_size;
199 /* Validate auxtrace_mmap_pages */
200 if (opts->auxtrace_mmap_pages) {
201 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
204 if (opts->auxtrace_snapshot_mode)
209 if (sz < min_sz || !is_power_of_2(sz)) {
210 pr_err("Invalid mmap size for Intel BTS: must be at least %zuKiB and a power of 2\n",
216 if (intel_bts_evsel) {
218 * To obtain the auxtrace buffer file descriptor, the auxtrace event
221 perf_evlist__to_front(evlist, intel_bts_evsel);
223 * In the case of per-cpu mmaps, we need the CPU on the
226 if (!cpu_map__empty(cpus))
227 perf_evsel__set_sample_bit(intel_bts_evsel, CPU);
230 /* Add dummy event to keep tracking */
231 if (opts->full_auxtrace) {
232 struct perf_evsel *tracking_evsel;
235 err = parse_events(evlist, "dummy:u", NULL);
239 tracking_evsel = perf_evlist__last(evlist);
241 perf_evlist__set_tracking_event(evlist, tracking_evsel);
243 tracking_evsel->attr.freq = 0;
244 tracking_evsel->attr.sample_period = 1;
250 static int intel_bts_parse_snapshot_options(struct auxtrace_record *itr,
251 struct record_opts *opts,
254 struct intel_bts_recording *btsr =
255 container_of(itr, struct intel_bts_recording, itr);
256 unsigned long long snapshot_size = 0;
260 snapshot_size = strtoull(str, &endptr, 0);
261 if (*endptr || snapshot_size > SIZE_MAX)
265 opts->auxtrace_snapshot_mode = true;
266 opts->auxtrace_snapshot_size = snapshot_size;
268 btsr->snapshot_size = snapshot_size;
273 static u64 intel_bts_reference(struct auxtrace_record *itr __maybe_unused)
278 static int intel_bts_alloc_snapshot_refs(struct intel_bts_recording *btsr,
281 const size_t sz = sizeof(struct intel_bts_snapshot_ref);
282 int cnt = btsr->snapshot_ref_cnt, new_cnt = cnt * 2;
283 struct intel_bts_snapshot_ref *refs;
288 while (new_cnt <= idx)
291 refs = calloc(new_cnt, sz);
295 memcpy(refs, btsr->snapshot_refs, cnt * sz);
297 btsr->snapshot_refs = refs;
298 btsr->snapshot_ref_cnt = new_cnt;
303 static void intel_bts_free_snapshot_refs(struct intel_bts_recording *btsr)
307 for (i = 0; i < btsr->snapshot_ref_cnt; i++)
308 zfree(&btsr->snapshot_refs[i].ref_buf);
309 zfree(&btsr->snapshot_refs);
312 static void intel_bts_recording_free(struct auxtrace_record *itr)
314 struct intel_bts_recording *btsr =
315 container_of(itr, struct intel_bts_recording, itr);
317 intel_bts_free_snapshot_refs(btsr);
321 static int intel_bts_snapshot_start(struct auxtrace_record *itr)
323 struct intel_bts_recording *btsr =
324 container_of(itr, struct intel_bts_recording, itr);
325 struct perf_evsel *evsel;
327 evlist__for_each_entry(btsr->evlist, evsel) {
328 if (evsel->attr.type == btsr->intel_bts_pmu->type)
329 return perf_evsel__disable(evsel);
334 static int intel_bts_snapshot_finish(struct auxtrace_record *itr)
336 struct intel_bts_recording *btsr =
337 container_of(itr, struct intel_bts_recording, itr);
338 struct perf_evsel *evsel;
340 evlist__for_each_entry(btsr->evlist, evsel) {
341 if (evsel->attr.type == btsr->intel_bts_pmu->type)
342 return perf_evsel__enable(evsel);
347 static bool intel_bts_first_wrap(u64 *data, size_t buf_size)
356 for (i = a; i < b; i++) {
364 static int intel_bts_find_snapshot(struct auxtrace_record *itr, int idx,
365 struct auxtrace_mmap *mm, unsigned char *data,
368 struct intel_bts_recording *btsr =
369 container_of(itr, struct intel_bts_recording, itr);
373 pr_debug3("%s: mmap index %d old head %zu new head %zu\n",
374 __func__, idx, (size_t)*old, (size_t)*head);
376 if (idx >= btsr->snapshot_ref_cnt) {
377 err = intel_bts_alloc_snapshot_refs(btsr, idx);
382 wrapped = btsr->snapshot_refs[idx].wrapped;
383 if (!wrapped && intel_bts_first_wrap((u64 *)data, mm->len)) {
384 btsr->snapshot_refs[idx].wrapped = true;
389 * In full trace mode 'head' continually increases. However in snapshot
390 * mode 'head' is an offset within the buffer. Here 'old' and 'head'
391 * are adjusted to match the full trace case which expects that 'old' is
392 * always less than 'head'.
406 pr_debug3("%s: wrap-around %sdetected, adjusted old head %zu adjusted new head %zu\n",
407 __func__, wrapped ? "" : "not ", (size_t)*old, (size_t)*head);
412 pr_err("%s: failed, error %d\n", __func__, err);
416 static int intel_bts_read_finish(struct auxtrace_record *itr, int idx)
418 struct intel_bts_recording *btsr =
419 container_of(itr, struct intel_bts_recording, itr);
420 struct perf_evsel *evsel;
422 evlist__for_each_entry(btsr->evlist, evsel) {
423 if (evsel->attr.type == btsr->intel_bts_pmu->type)
424 return perf_evlist__enable_event_idx(btsr->evlist,
430 struct auxtrace_record *intel_bts_recording_init(int *err)
432 struct perf_pmu *intel_bts_pmu = perf_pmu__find(INTEL_BTS_PMU_NAME);
433 struct intel_bts_recording *btsr;
438 if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) {
443 btsr = zalloc(sizeof(struct intel_bts_recording));
449 btsr->intel_bts_pmu = intel_bts_pmu;
450 btsr->itr.recording_options = intel_bts_recording_options;
451 btsr->itr.info_priv_size = intel_bts_info_priv_size;
452 btsr->itr.info_fill = intel_bts_info_fill;
453 btsr->itr.free = intel_bts_recording_free;
454 btsr->itr.snapshot_start = intel_bts_snapshot_start;
455 btsr->itr.snapshot_finish = intel_bts_snapshot_finish;
456 btsr->itr.find_snapshot = intel_bts_find_snapshot;
457 btsr->itr.parse_snapshot_options = intel_bts_parse_snapshot_options;
458 btsr->itr.reference = intel_bts_reference;
459 btsr->itr.read_finish = intel_bts_read_finish;
460 btsr->itr.alignment = sizeof(struct branch);