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7#include <errno.h>
8#include <linux/kernel.h>
9#include <linux/types.h>
10#include <linux/bitops.h>
11#include <linux/log2.h>
12#include <linux/zalloc.h>
13
14#include "../../util/cpumap.h"
15#include "../../util/evsel.h"
16#include "../../util/evlist.h"
17#include "../../util/session.h"
18#include "../../util/pmu.h"
19#include "../../util/debug.h"
20#include "../../util/tsc.h"
21#include "../../util/auxtrace.h"
22#include "../../util/intel-bts.h"
23
24#define KiB(x) ((x) * 1024)
25#define MiB(x) ((x) * 1024 * 1024)
26#define KiB_MASK(x) (KiB(x) - 1)
27#define MiB_MASK(x) (MiB(x) - 1)
28
29struct intel_bts_snapshot_ref {
30 void *ref_buf;
31 size_t ref_offset;
32 bool wrapped;
33};
34
35struct intel_bts_recording {
36 struct auxtrace_record itr;
37 struct perf_pmu *intel_bts_pmu;
38 struct perf_evlist *evlist;
39 bool snapshot_mode;
40 size_t snapshot_size;
41 int snapshot_ref_cnt;
42 struct intel_bts_snapshot_ref *snapshot_refs;
43};
44
45struct branch {
46 u64 from;
47 u64 to;
48 u64 misc;
49};
50
51static size_t
52intel_bts_info_priv_size(struct auxtrace_record *itr __maybe_unused,
53 struct perf_evlist *evlist __maybe_unused)
54{
55 return INTEL_BTS_AUXTRACE_PRIV_SIZE;
56}
57
58static int intel_bts_info_fill(struct auxtrace_record *itr,
59 struct perf_session *session,
60 struct auxtrace_info_event *auxtrace_info,
61 size_t priv_size)
62{
63 struct intel_bts_recording *btsr =
64 container_of(itr, struct intel_bts_recording, itr);
65 struct perf_pmu *intel_bts_pmu = btsr->intel_bts_pmu;
66 struct perf_event_mmap_page *pc;
67 struct perf_tsc_conversion tc = { .time_mult = 0, };
68 bool cap_user_time_zero = false;
69 int err;
70
71 if (priv_size != INTEL_BTS_AUXTRACE_PRIV_SIZE)
72 return -EINVAL;
73
74 if (!session->evlist->nr_mmaps)
75 return -EINVAL;
76
77 pc = session->evlist->mmap[0].base;
78 if (pc) {
79 err = perf_read_tsc_conversion(pc, &tc);
80 if (err) {
81 if (err != -EOPNOTSUPP)
82 return err;
83 } else {
84 cap_user_time_zero = tc.time_mult != 0;
85 }
86 if (!cap_user_time_zero)
87 ui__warning("Intel BTS: TSC not available\n");
88 }
89
90 auxtrace_info->type = PERF_AUXTRACE_INTEL_BTS;
91 auxtrace_info->priv[INTEL_BTS_PMU_TYPE] = intel_bts_pmu->type;
92 auxtrace_info->priv[INTEL_BTS_TIME_SHIFT] = tc.time_shift;
93 auxtrace_info->priv[INTEL_BTS_TIME_MULT] = tc.time_mult;
94 auxtrace_info->priv[INTEL_BTS_TIME_ZERO] = tc.time_zero;
95 auxtrace_info->priv[INTEL_BTS_CAP_USER_TIME_ZERO] = cap_user_time_zero;
96 auxtrace_info->priv[INTEL_BTS_SNAPSHOT_MODE] = btsr->snapshot_mode;
97
98 return 0;
99}
100
101static int intel_bts_recording_options(struct auxtrace_record *itr,
102 struct perf_evlist *evlist,
103 struct record_opts *opts)
104{
105 struct intel_bts_recording *btsr =
106 container_of(itr, struct intel_bts_recording, itr);
107 struct perf_pmu *intel_bts_pmu = btsr->intel_bts_pmu;
108 struct perf_evsel *evsel, *intel_bts_evsel = NULL;
109 const struct cpu_map *cpus = evlist->cpus;
110 bool privileged = geteuid() == 0 || perf_event_paranoid() < 0;
111
112 btsr->evlist = evlist;
113 btsr->snapshot_mode = opts->auxtrace_snapshot_mode;
114
115 evlist__for_each_entry(evlist, evsel) {
116 if (evsel->attr.type == intel_bts_pmu->type) {
117 if (intel_bts_evsel) {
118 pr_err("There may be only one " INTEL_BTS_PMU_NAME " event\n");
119 return -EINVAL;
120 }
121 evsel->attr.freq = 0;
122 evsel->attr.sample_period = 1;
123 intel_bts_evsel = evsel;
124 opts->full_auxtrace = true;
125 }
126 }
127
128 if (opts->auxtrace_snapshot_mode && !opts->full_auxtrace) {
129 pr_err("Snapshot mode (-S option) requires " INTEL_BTS_PMU_NAME " PMU event (-e " INTEL_BTS_PMU_NAME ")\n");
130 return -EINVAL;
131 }
132
133 if (!opts->full_auxtrace)
134 return 0;
135
136 if (opts->full_auxtrace && !cpu_map__empty(cpus)) {
137 pr_err(INTEL_BTS_PMU_NAME " does not support per-cpu recording\n");
138 return -EINVAL;
139 }
140
141
142 if (opts->auxtrace_snapshot_mode) {
143 if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) {
144 if (privileged) {
145 opts->auxtrace_mmap_pages = MiB(4) / page_size;
146 } else {
147 opts->auxtrace_mmap_pages = KiB(128) / page_size;
148 if (opts->mmap_pages == UINT_MAX)
149 opts->mmap_pages = KiB(256) / page_size;
150 }
151 } else if (!opts->auxtrace_mmap_pages && !privileged &&
152 opts->mmap_pages == UINT_MAX) {
153 opts->mmap_pages = KiB(256) / page_size;
154 }
155 if (!opts->auxtrace_snapshot_size)
156 opts->auxtrace_snapshot_size =
157 opts->auxtrace_mmap_pages * (size_t)page_size;
158 if (!opts->auxtrace_mmap_pages) {
159 size_t sz = opts->auxtrace_snapshot_size;
160
161 sz = round_up(sz, page_size) / page_size;
162 opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
163 }
164 if (opts->auxtrace_snapshot_size >
165 opts->auxtrace_mmap_pages * (size_t)page_size) {
166 pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n",
167 opts->auxtrace_snapshot_size,
168 opts->auxtrace_mmap_pages * (size_t)page_size);
169 return -EINVAL;
170 }
171 if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages) {
172 pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n");
173 return -EINVAL;
174 }
175 pr_debug2("Intel BTS snapshot size: %zu\n",
176 opts->auxtrace_snapshot_size);
177 }
178
179
180 if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
181 if (privileged) {
182 opts->auxtrace_mmap_pages = MiB(4) / page_size;
183 } else {
184 opts->auxtrace_mmap_pages = KiB(128) / page_size;
185 if (opts->mmap_pages == UINT_MAX)
186 opts->mmap_pages = KiB(256) / page_size;
187 }
188 }
189
190
191 if (opts->auxtrace_mmap_pages) {
192 size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
193 size_t min_sz;
194
195 if (opts->auxtrace_snapshot_mode)
196 min_sz = KiB(4);
197 else
198 min_sz = KiB(8);
199
200 if (sz < min_sz || !is_power_of_2(sz)) {
201 pr_err("Invalid mmap size for Intel BTS: must be at least %zuKiB and a power of 2\n",
202 min_sz / 1024);
203 return -EINVAL;
204 }
205 }
206
207 if (intel_bts_evsel) {
208
209
210
211
212 perf_evlist__to_front(evlist, intel_bts_evsel);
213
214
215
216
217 if (!cpu_map__empty(cpus))
218 perf_evsel__set_sample_bit(intel_bts_evsel, CPU);
219 }
220
221
222 if (opts->full_auxtrace) {
223 struct perf_evsel *tracking_evsel;
224 int err;
225
226 err = parse_events(evlist, "dummy:u", NULL);
227 if (err)
228 return err;
229
230 tracking_evsel = perf_evlist__last(evlist);
231
232 perf_evlist__set_tracking_event(evlist, tracking_evsel);
233
234 tracking_evsel->attr.freq = 0;
235 tracking_evsel->attr.sample_period = 1;
236 }
237
238 return 0;
239}
240
241static int intel_bts_parse_snapshot_options(struct auxtrace_record *itr,
242 struct record_opts *opts,
243 const char *str)
244{
245 struct intel_bts_recording *btsr =
246 container_of(itr, struct intel_bts_recording, itr);
247 unsigned long long snapshot_size = 0;
248 char *endptr;
249
250 if (str) {
251 snapshot_size = strtoull(str, &endptr, 0);
252 if (*endptr || snapshot_size > SIZE_MAX)
253 return -1;
254 }
255
256 opts->auxtrace_snapshot_mode = true;
257 opts->auxtrace_snapshot_size = snapshot_size;
258
259 btsr->snapshot_size = snapshot_size;
260
261 return 0;
262}
263
264static u64 intel_bts_reference(struct auxtrace_record *itr __maybe_unused)
265{
266 return rdtsc();
267}
268
269static int intel_bts_alloc_snapshot_refs(struct intel_bts_recording *btsr,
270 int idx)
271{
272 const size_t sz = sizeof(struct intel_bts_snapshot_ref);
273 int cnt = btsr->snapshot_ref_cnt, new_cnt = cnt * 2;
274 struct intel_bts_snapshot_ref *refs;
275
276 if (!new_cnt)
277 new_cnt = 16;
278
279 while (new_cnt <= idx)
280 new_cnt *= 2;
281
282 refs = calloc(new_cnt, sz);
283 if (!refs)
284 return -ENOMEM;
285
286 memcpy(refs, btsr->snapshot_refs, cnt * sz);
287
288 btsr->snapshot_refs = refs;
289 btsr->snapshot_ref_cnt = new_cnt;
290
291 return 0;
292}
293
294static void intel_bts_free_snapshot_refs(struct intel_bts_recording *btsr)
295{
296 int i;
297
298 for (i = 0; i < btsr->snapshot_ref_cnt; i++)
299 zfree(&btsr->snapshot_refs[i].ref_buf);
300 zfree(&btsr->snapshot_refs);
301}
302
303static void intel_bts_recording_free(struct auxtrace_record *itr)
304{
305 struct intel_bts_recording *btsr =
306 container_of(itr, struct intel_bts_recording, itr);
307
308 intel_bts_free_snapshot_refs(btsr);
309 free(btsr);
310}
311
312static int intel_bts_snapshot_start(struct auxtrace_record *itr)
313{
314 struct intel_bts_recording *btsr =
315 container_of(itr, struct intel_bts_recording, itr);
316 struct perf_evsel *evsel;
317
318 evlist__for_each_entry(btsr->evlist, evsel) {
319 if (evsel->attr.type == btsr->intel_bts_pmu->type)
320 return perf_evsel__disable(evsel);
321 }
322 return -EINVAL;
323}
324
325static int intel_bts_snapshot_finish(struct auxtrace_record *itr)
326{
327 struct intel_bts_recording *btsr =
328 container_of(itr, struct intel_bts_recording, itr);
329 struct perf_evsel *evsel;
330
331 evlist__for_each_entry(btsr->evlist, evsel) {
332 if (evsel->attr.type == btsr->intel_bts_pmu->type)
333 return perf_evsel__enable(evsel);
334 }
335 return -EINVAL;
336}
337
338static bool intel_bts_first_wrap(u64 *data, size_t buf_size)
339{
340 int i, a, b;
341
342 b = buf_size >> 3;
343 a = b - 512;
344 if (a < 0)
345 a = 0;
346
347 for (i = a; i < b; i++) {
348 if (data[i])
349 return true;
350 }
351
352 return false;
353}
354
355static int intel_bts_find_snapshot(struct auxtrace_record *itr, int idx,
356 struct auxtrace_mmap *mm, unsigned char *data,
357 u64 *head, u64 *old)
358{
359 struct intel_bts_recording *btsr =
360 container_of(itr, struct intel_bts_recording, itr);
361 bool wrapped;
362 int err;
363
364 pr_debug3("%s: mmap index %d old head %zu new head %zu\n",
365 __func__, idx, (size_t)*old, (size_t)*head);
366
367 if (idx >= btsr->snapshot_ref_cnt) {
368 err = intel_bts_alloc_snapshot_refs(btsr, idx);
369 if (err)
370 goto out_err;
371 }
372
373 wrapped = btsr->snapshot_refs[idx].wrapped;
374 if (!wrapped && intel_bts_first_wrap((u64 *)data, mm->len)) {
375 btsr->snapshot_refs[idx].wrapped = true;
376 wrapped = true;
377 }
378
379
380
381
382
383
384
385 if (wrapped) {
386 *old = *head;
387 *head += mm->len;
388 } else {
389 if (mm->mask)
390 *old &= mm->mask;
391 else
392 *old %= mm->len;
393 if (*old > *head)
394 *head += mm->len;
395 }
396
397 pr_debug3("%s: wrap-around %sdetected, adjusted old head %zu adjusted new head %zu\n",
398 __func__, wrapped ? "" : "not ", (size_t)*old, (size_t)*head);
399
400 return 0;
401
402out_err:
403 pr_err("%s: failed, error %d\n", __func__, err);
404 return err;
405}
406
407static int intel_bts_read_finish(struct auxtrace_record *itr, int idx)
408{
409 struct intel_bts_recording *btsr =
410 container_of(itr, struct intel_bts_recording, itr);
411 struct perf_evsel *evsel;
412
413 evlist__for_each_entry(btsr->evlist, evsel) {
414 if (evsel->attr.type == btsr->intel_bts_pmu->type)
415 return perf_evlist__enable_event_idx(btsr->evlist,
416 evsel, idx);
417 }
418 return -EINVAL;
419}
420
421struct auxtrace_record *intel_bts_recording_init(int *err)
422{
423 struct perf_pmu *intel_bts_pmu = perf_pmu__find(INTEL_BTS_PMU_NAME);
424 struct intel_bts_recording *btsr;
425
426 if (!intel_bts_pmu)
427 return NULL;
428
429 if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) {
430 *err = -errno;
431 return NULL;
432 }
433
434 btsr = zalloc(sizeof(struct intel_bts_recording));
435 if (!btsr) {
436 *err = -ENOMEM;
437 return NULL;
438 }
439
440 btsr->intel_bts_pmu = intel_bts_pmu;
441 btsr->itr.recording_options = intel_bts_recording_options;
442 btsr->itr.info_priv_size = intel_bts_info_priv_size;
443 btsr->itr.info_fill = intel_bts_info_fill;
444 btsr->itr.free = intel_bts_recording_free;
445 btsr->itr.snapshot_start = intel_bts_snapshot_start;
446 btsr->itr.snapshot_finish = intel_bts_snapshot_finish;
447 btsr->itr.find_snapshot = intel_bts_find_snapshot;
448 btsr->itr.parse_snapshot_options = intel_bts_parse_snapshot_options;
449 btsr->itr.reference = intel_bts_reference;
450 btsr->itr.read_finish = intel_bts_read_finish;
451 btsr->itr.alignment = sizeof(struct branch);
452 return &btsr->itr;
453}
454
