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16#include <errno.h>
17#include <linux/kernel.h>
18#include <linux/types.h>
19#include <linux/bitops.h>
20#include <linux/log2.h>
21
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"
32
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)
37
38struct intel_bts_snapshot_ref {
39 void *ref_buf;
40 size_t ref_offset;
41 bool wrapped;
42};
43
44struct intel_bts_recording {
45 struct auxtrace_record itr;
46 struct perf_pmu *intel_bts_pmu;
47 struct perf_evlist *evlist;
48 bool snapshot_mode;
49 size_t snapshot_size;
50 int snapshot_ref_cnt;
51 struct intel_bts_snapshot_ref *snapshot_refs;
52};
53
54struct branch {
55 u64 from;
56 u64 to;
57 u64 misc;
58};
59
60static size_t
61intel_bts_info_priv_size(struct auxtrace_record *itr __maybe_unused,
62 struct perf_evlist *evlist __maybe_unused)
63{
64 return INTEL_BTS_AUXTRACE_PRIV_SIZE;
65}
66
67static int intel_bts_info_fill(struct auxtrace_record *itr,
68 struct perf_session *session,
69 struct auxtrace_info_event *auxtrace_info,
70 size_t priv_size)
71{
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;
78 int err;
79
80 if (priv_size != INTEL_BTS_AUXTRACE_PRIV_SIZE)
81 return -EINVAL;
82
83 if (!session->evlist->nr_mmaps)
84 return -EINVAL;
85
86 pc = session->evlist->mmap[0].base;
87 if (pc) {
88 err = perf_read_tsc_conversion(pc, &tc);
89 if (err) {
90 if (err != -EOPNOTSUPP)
91 return err;
92 } else {
93 cap_user_time_zero = tc.time_mult != 0;
94 }
95 if (!cap_user_time_zero)
96 ui__warning("Intel BTS: TSC not available\n");
97 }
98
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;
106
107 return 0;
108}
109
110static int intel_bts_recording_options(struct auxtrace_record *itr,
111 struct perf_evlist *evlist,
112 struct record_opts *opts)
113{
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;
120
121 btsr->evlist = evlist;
122 btsr->snapshot_mode = opts->auxtrace_snapshot_mode;
123
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");
128 return -EINVAL;
129 }
130 evsel->attr.freq = 0;
131 evsel->attr.sample_period = 1;
132 intel_bts_evsel = evsel;
133 opts->full_auxtrace = true;
134 }
135 }
136
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");
139 return -EINVAL;
140 }
141
142 if (!opts->full_auxtrace)
143 return 0;
144
145 if (opts->full_auxtrace && !cpu_map__empty(cpus)) {
146 pr_err(INTEL_BTS_PMU_NAME " does not support per-cpu recording\n");
147 return -EINVAL;
148 }
149
150
151 if (opts->auxtrace_snapshot_mode) {
152 if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) {
153 if (privileged) {
154 opts->auxtrace_mmap_pages = MiB(4) / page_size;
155 } else {
156 opts->auxtrace_mmap_pages = KiB(128) / page_size;
157 if (opts->mmap_pages == UINT_MAX)
158 opts->mmap_pages = KiB(256) / page_size;
159 }
160 } else if (!opts->auxtrace_mmap_pages && !privileged &&
161 opts->mmap_pages == UINT_MAX) {
162 opts->mmap_pages = KiB(256) / page_size;
163 }
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;
169
170 sz = round_up(sz, page_size) / page_size;
171 opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
172 }
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);
178 return -EINVAL;
179 }
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");
182 return -EINVAL;
183 }
184 pr_debug2("Intel BTS snapshot size: %zu\n",
185 opts->auxtrace_snapshot_size);
186 }
187
188
189 if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
190 if (privileged) {
191 opts->auxtrace_mmap_pages = MiB(4) / page_size;
192 } else {
193 opts->auxtrace_mmap_pages = KiB(128) / page_size;
194 if (opts->mmap_pages == UINT_MAX)
195 opts->mmap_pages = KiB(256) / page_size;
196 }
197 }
198
199
200 if (opts->auxtrace_mmap_pages) {
201 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
202 size_t min_sz;
203
204 if (opts->auxtrace_snapshot_mode)
205 min_sz = KiB(4);
206 else
207 min_sz = KiB(8);
208
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",
211 min_sz / 1024);
212 return -EINVAL;
213 }
214 }
215
216 if (intel_bts_evsel) {
217
218
219
220
221 perf_evlist__to_front(evlist, intel_bts_evsel);
222
223
224
225
226 if (!cpu_map__empty(cpus))
227 perf_evsel__set_sample_bit(intel_bts_evsel, CPU);
228 }
229
230
231 if (opts->full_auxtrace) {
232 struct perf_evsel *tracking_evsel;
233 int err;
234
235 err = parse_events(evlist, "dummy:u", NULL);
236 if (err)
237 return err;
238
239 tracking_evsel = perf_evlist__last(evlist);
240
241 perf_evlist__set_tracking_event(evlist, tracking_evsel);
242
243 tracking_evsel->attr.freq = 0;
244 tracking_evsel->attr.sample_period = 1;
245 }
246
247 return 0;
248}
249
250static int intel_bts_parse_snapshot_options(struct auxtrace_record *itr,
251 struct record_opts *opts,
252 const char *str)
253{
254 struct intel_bts_recording *btsr =
255 container_of(itr, struct intel_bts_recording, itr);
256 unsigned long long snapshot_size = 0;
257 char *endptr;
258
259 if (str) {
260 snapshot_size = strtoull(str, &endptr, 0);
261 if (*endptr || snapshot_size > SIZE_MAX)
262 return -1;
263 }
264
265 opts->auxtrace_snapshot_mode = true;
266 opts->auxtrace_snapshot_size = snapshot_size;
267
268 btsr->snapshot_size = snapshot_size;
269
270 return 0;
271}
272
273static u64 intel_bts_reference(struct auxtrace_record *itr __maybe_unused)
274{
275 return rdtsc();
276}
277
278static int intel_bts_alloc_snapshot_refs(struct intel_bts_recording *btsr,
279 int idx)
280{
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;
284
285 if (!new_cnt)
286 new_cnt = 16;
287
288 while (new_cnt <= idx)
289 new_cnt *= 2;
290
291 refs = calloc(new_cnt, sz);
292 if (!refs)
293 return -ENOMEM;
294
295 memcpy(refs, btsr->snapshot_refs, cnt * sz);
296
297 btsr->snapshot_refs = refs;
298 btsr->snapshot_ref_cnt = new_cnt;
299
300 return 0;
301}
302
303static void intel_bts_free_snapshot_refs(struct intel_bts_recording *btsr)
304{
305 int i;
306
307 for (i = 0; i < btsr->snapshot_ref_cnt; i++)
308 zfree(&btsr->snapshot_refs[i].ref_buf);
309 zfree(&btsr->snapshot_refs);
310}
311
312static void intel_bts_recording_free(struct auxtrace_record *itr)
313{
314 struct intel_bts_recording *btsr =
315 container_of(itr, struct intel_bts_recording, itr);
316
317 intel_bts_free_snapshot_refs(btsr);
318 free(btsr);
319}
320
321static int intel_bts_snapshot_start(struct auxtrace_record *itr)
322{
323 struct intel_bts_recording *btsr =
324 container_of(itr, struct intel_bts_recording, itr);
325 struct perf_evsel *evsel;
326
327 evlist__for_each_entry(btsr->evlist, evsel) {
328 if (evsel->attr.type == btsr->intel_bts_pmu->type)
329 return perf_evsel__disable(evsel);
330 }
331 return -EINVAL;
332}
333
334static int intel_bts_snapshot_finish(struct auxtrace_record *itr)
335{
336 struct intel_bts_recording *btsr =
337 container_of(itr, struct intel_bts_recording, itr);
338 struct perf_evsel *evsel;
339
340 evlist__for_each_entry(btsr->evlist, evsel) {
341 if (evsel->attr.type == btsr->intel_bts_pmu->type)
342 return perf_evsel__enable(evsel);
343 }
344 return -EINVAL;
345}
346
347static bool intel_bts_first_wrap(u64 *data, size_t buf_size)
348{
349 int i, a, b;
350
351 b = buf_size >> 3;
352 a = b - 512;
353 if (a < 0)
354 a = 0;
355
356 for (i = a; i < b; i++) {
357 if (data[i])
358 return true;
359 }
360
361 return false;
362}
363
364static int intel_bts_find_snapshot(struct auxtrace_record *itr, int idx,
365 struct auxtrace_mmap *mm, unsigned char *data,
366 u64 *head, u64 *old)
367{
368 struct intel_bts_recording *btsr =
369 container_of(itr, struct intel_bts_recording, itr);
370 bool wrapped;
371 int err;
372
373 pr_debug3("%s: mmap index %d old head %zu new head %zu\n",
374 __func__, idx, (size_t)*old, (size_t)*head);
375
376 if (idx >= btsr->snapshot_ref_cnt) {
377 err = intel_bts_alloc_snapshot_refs(btsr, idx);
378 if (err)
379 goto out_err;
380 }
381
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;
385 wrapped = true;
386 }
387
388
389
390
391
392
393
394 if (wrapped) {
395 *old = *head;
396 *head += mm->len;
397 } else {
398 if (mm->mask)
399 *old &= mm->mask;
400 else
401 *old %= mm->len;
402 if (*old > *head)
403 *head += mm->len;
404 }
405
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);
408
409 return 0;
410
411out_err:
412 pr_err("%s: failed, error %d\n", __func__, err);
413 return err;
414}
415
416static int intel_bts_read_finish(struct auxtrace_record *itr, int idx)
417{
418 struct intel_bts_recording *btsr =
419 container_of(itr, struct intel_bts_recording, itr);
420 struct perf_evsel *evsel;
421
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,
425 evsel, idx);
426 }
427 return -EINVAL;
428}
429
430struct auxtrace_record *intel_bts_recording_init(int *err)
431{
432 struct perf_pmu *intel_bts_pmu = perf_pmu__find(INTEL_BTS_PMU_NAME);
433 struct intel_bts_recording *btsr;
434
435 if (!intel_bts_pmu)
436 return NULL;
437
438 if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) {
439 *err = -errno;
440 return NULL;
441 }
442
443 btsr = zalloc(sizeof(struct intel_bts_recording));
444 if (!btsr) {
445 *err = -ENOMEM;
446 return NULL;
447 }
448
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);
461 return &btsr->itr;
462}
463
