tools/perf/util/intel-pt-decoder/intel-pt-decoder.c

   1 /*
   2  * intel_pt_decoder.c: Intel Processor Trace support
   3  * Copyright (c) 2013-2014, Intel Corporation.
   4  *
   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.
   8  *
   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
  12  * more details.
  13  *
  14  */
  15
  16 #ifndef _GNU_SOURCE
  17 #define _GNU_SOURCE
  18 #endif
  19 #include <stdlib.h>
  20 #include <stdbool.h>
  21 #include <string.h>
  22 #include <errno.h>
  23 #include <stdint.h>
  24 #include <inttypes.h>
  25
  26 #include "../cache.h"
  27 #include "../util.h"
  28
  29 #include "intel-pt-insn-decoder.h"
  30 #include "intel-pt-pkt-decoder.h"
  31 #include "intel-pt-decoder.h"
  32 #include "intel-pt-log.h"
  33
  34 #define INTEL_PT_BLK_SIZE 1024
  35
  36 #define BIT63 (((uint64_t)1 << 63))
  37
  38 #define INTEL_PT_RETURN 1
  39
  40 /* Maximum number of loops with no packets consumed i.e. stuck in a loop */
  41 #define INTEL_PT_MAX_LOOPS 10000
  42
  43 struct intel_pt_blk {
  44         struct intel_pt_blk *prev;
  45         uint64_t ip[INTEL_PT_BLK_SIZE];
  46 };
  47
  48 struct intel_pt_stack {
  49         struct intel_pt_blk *blk;
  50         struct intel_pt_blk *spare;
  51         int pos;
  52 };
  53
  54 enum intel_pt_pkt_state {
  55         INTEL_PT_STATE_NO_PSB,
  56         INTEL_PT_STATE_NO_IP,
  57         INTEL_PT_STATE_ERR_RESYNC,
  58         INTEL_PT_STATE_IN_SYNC,
  59         INTEL_PT_STATE_TNT,
  60         INTEL_PT_STATE_TIP,
  61         INTEL_PT_STATE_TIP_PGD,
  62         INTEL_PT_STATE_FUP,
  63         INTEL_PT_STATE_FUP_NO_TIP,
  64 };
  65
  66 #ifdef INTEL_PT_STRICT
  67 #define INTEL_PT_STATE_ERR1     INTEL_PT_STATE_NO_PSB
  68 #define INTEL_PT_STATE_ERR2     INTEL_PT_STATE_NO_PSB
  69 #define INTEL_PT_STATE_ERR3     INTEL_PT_STATE_NO_PSB
  70 #define INTEL_PT_STATE_ERR4     INTEL_PT_STATE_NO_PSB
  71 #else
  72 #define INTEL_PT_STATE_ERR1     (decoder->pkt_state)
  73 #define INTEL_PT_STATE_ERR2     INTEL_PT_STATE_NO_IP
  74 #define INTEL_PT_STATE_ERR3     INTEL_PT_STATE_ERR_RESYNC
  75 #define INTEL_PT_STATE_ERR4     INTEL_PT_STATE_IN_SYNC
  76 #endif
  77
  78 struct intel_pt_decoder {
  79         int (*get_trace)(struct intel_pt_buffer *buffer, void *data);
  80         int (*walk_insn)(struct intel_pt_insn *intel_pt_insn,
  81                          uint64_t *insn_cnt_ptr, uint64_t *ip, uint64_t to_ip,
  82                          uint64_t max_insn_cnt, void *data);
  83         void *data;
  84         struct intel_pt_state state;
  85         const unsigned char *buf;
  86         size_t len;
  87         bool return_compression;
  88         bool mtc_insn;
  89         bool pge;
  90         bool have_tma;
  91         bool have_cyc;
  92         uint64_t pos;
  93         uint64_t last_ip;
  94         uint64_t ip;
  95         uint64_t cr3;
  96         uint64_t timestamp;
  97         uint64_t tsc_timestamp;
  98         uint64_t ref_timestamp;
  99         uint64_t ret_addr;
 100         uint64_t ctc_timestamp;
 101         uint64_t ctc_delta;
 102         uint64_t cycle_cnt;
 103         uint64_t cyc_ref_timestamp;
 104         uint32_t last_mtc;
 105         uint32_t tsc_ctc_ratio_n;
 106         uint32_t tsc_ctc_ratio_d;
 107         uint32_t tsc_ctc_mult;
 108         uint32_t tsc_slip;
 109         uint32_t ctc_rem_mask;
 110         int mtc_shift;
 111         struct intel_pt_stack stack;
 112         enum intel_pt_pkt_state pkt_state;
 113         struct intel_pt_pkt packet;
 114         struct intel_pt_pkt tnt;
 115         int pkt_step;
 116         int pkt_len;
 117         int last_packet_type;
 118         unsigned int cbr;
 119         unsigned int max_non_turbo_ratio;
 120         double max_non_turbo_ratio_fp;
 121         double cbr_cyc_to_tsc;
 122         double calc_cyc_to_tsc;
 123         bool have_calc_cyc_to_tsc;
 124         int exec_mode;
 125         unsigned int insn_bytes;
 126         uint64_t period;
 127         enum intel_pt_period_type period_type;
 128         uint64_t tot_insn_cnt;
 129         uint64_t period_insn_cnt;
 130         uint64_t period_mask;
 131         uint64_t period_ticks;
 132         uint64_t last_masked_timestamp;
 133         bool continuous_period;
 134         bool overflow;
 135         bool set_fup_tx_flags;
 136         unsigned int fup_tx_flags;
 137         unsigned int tx_flags;
 138         uint64_t timestamp_insn_cnt;
 139         uint64_t stuck_ip;
 140         int no_progress;
 141         int stuck_ip_prd;
 142         int stuck_ip_cnt;
 143         const unsigned char *next_buf;
 144         size_t next_len;
 145         unsigned char temp_buf[INTEL_PT_PKT_MAX_SZ];
 146 };
 147
 148 static uint64_t intel_pt_lower_power_of_2(uint64_t x)
 149 {
 150         int i;
 151
 152         for (i = 0; x != 1; i++)
 153                 x >>= 1;
 154
 155         return x << i;
 156 }
 157
 158 static void intel_pt_setup_period(struct intel_pt_decoder *decoder)
 159 {
 160         if (decoder->period_type == INTEL_PT_PERIOD_TICKS) {
 161                 uint64_t period;
 162
 163                 period = intel_pt_lower_power_of_2(decoder->period);
 164                 decoder->period_mask  = ~(period - 1);
 165                 decoder->period_ticks = period;
 166         }
 167 }
 168
 169 static uint64_t multdiv(uint64_t t, uint32_t n, uint32_t d)
 170 {
 171         if (!d)
 172                 return 0;
 173         return (t / d) * n + ((t % d) * n) / d;
 174 }
 175
 176 struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params)
 177 {
 178         struct intel_pt_decoder *decoder;
 179
 180         if (!params->get_trace || !params->walk_insn)
 181                 return NULL;
 182
 183         decoder = zalloc(sizeof(struct intel_pt_decoder));
 184         if (!decoder)
 185                 return NULL;
 186
 187         decoder->get_trace          = params->get_trace;
 188         decoder->walk_insn          = params->walk_insn;
 189         decoder->data               = params->data;
 190         decoder->return_compression = params->return_compression;
 191
 192         decoder->period             = params->period;
 193         decoder->period_type        = params->period_type;
 194
 195         decoder->max_non_turbo_ratio    = params->max_non_turbo_ratio;
 196         decoder->max_non_turbo_ratio_fp = params->max_non_turbo_ratio;
 197
 198         intel_pt_setup_period(decoder);
 199
 200         decoder->mtc_shift = params->mtc_period;
 201         decoder->ctc_rem_mask = (1 << decoder->mtc_shift) - 1;
 202
 203         decoder->tsc_ctc_ratio_n = params->tsc_ctc_ratio_n;
 204         decoder->tsc_ctc_ratio_d = params->tsc_ctc_ratio_d;
 205
 206         if (!decoder->tsc_ctc_ratio_n)
 207                 decoder->tsc_ctc_ratio_d = 0;
 208
 209         if (decoder->tsc_ctc_ratio_d) {
 210                 if (!(decoder->tsc_ctc_ratio_n % decoder->tsc_ctc_ratio_d))
 211                         decoder->tsc_ctc_mult = decoder->tsc_ctc_ratio_n /
 212                                                 decoder->tsc_ctc_ratio_d;
 213
 214                 /*
 215                  * Allow for timestamps appearing to backwards because a TSC
 216                  * packet has slipped past a MTC packet, so allow 2 MTC ticks
 217                  * or ...
 218                  */
 219                 decoder->tsc_slip = multdiv(2 << decoder->mtc_shift,
 220                                         decoder->tsc_ctc_ratio_n,
 221                                         decoder->tsc_ctc_ratio_d);
 222         }
 223         /* ... or 0x100 paranoia */
 224         if (decoder->tsc_slip < 0x100)
 225                 decoder->tsc_slip = 0x100;
 226
 227         intel_pt_log("timestamp: mtc_shift %u\n", decoder->mtc_shift);
 228         intel_pt_log("timestamp: tsc_ctc_ratio_n %u\n", decoder->tsc_ctc_ratio_n);
 229         intel_pt_log("timestamp: tsc_ctc_ratio_d %u\n", decoder->tsc_ctc_ratio_d);
 230         intel_pt_log("timestamp: tsc_ctc_mult %u\n", decoder->tsc_ctc_mult);
 231         intel_pt_log("timestamp: tsc_slip %#x\n", decoder->tsc_slip);
 232
 233         return decoder;
 234 }
 235
 236 static void intel_pt_pop_blk(struct intel_pt_stack *stack)
 237 {
 238         struct intel_pt_blk *blk = stack->blk;
 239
 240         stack->blk = blk->prev;
 241         if (!stack->spare)
 242                 stack->spare = blk;
 243         else
 244                 free(blk);
 245 }
 246
 247 static uint64_t intel_pt_pop(struct intel_pt_stack *stack)
 248 {
 249         if (!stack->pos) {
 250                 if (!stack->blk)
 251                         return 0;
 252                 intel_pt_pop_blk(stack);
 253                 if (!stack->blk)
 254                         return 0;
 255                 stack->pos = INTEL_PT_BLK_SIZE;
 256         }
 257         return stack->blk->ip[--stack->pos];
 258 }
 259
 260 static int intel_pt_alloc_blk(struct intel_pt_stack *stack)
 261 {
 262         struct intel_pt_blk *blk;
 263
 264         if (stack->spare) {
 265                 blk = stack->spare;
 266                 stack->spare = NULL;
 267         } else {
 268                 blk = malloc(sizeof(struct intel_pt_blk));
 269                 if (!blk)
 270                         return -ENOMEM;
 271         }
 272
 273         blk->prev = stack->blk;
 274         stack->blk = blk;
 275         stack->pos = 0;
 276         return 0;
 277 }
 278
 279 static int intel_pt_push(struct intel_pt_stack *stack, uint64_t ip)
 280 {
 281         int err;
 282
 283         if (!stack->blk || stack->pos == INTEL_PT_BLK_SIZE) {
 284                 err = intel_pt_alloc_blk(stack);
 285                 if (err)
 286                         return err;
 287         }
 288
 289         stack->blk->ip[stack->pos++] = ip;
 290         return 0;
 291 }
 292
 293 static void intel_pt_clear_stack(struct intel_pt_stack *stack)
 294 {
 295         while (stack->blk)
 296                 intel_pt_pop_blk(stack);
 297         stack->pos = 0;
 298 }
 299
 300 static void intel_pt_free_stack(struct intel_pt_stack *stack)
 301 {
 302         intel_pt_clear_stack(stack);
 303         zfree(&stack->blk);
 304         zfree(&stack->spare);
 305 }
 306
 307 void intel_pt_decoder_free(struct intel_pt_decoder *decoder)
 308 {
 309         intel_pt_free_stack(&decoder->stack);
 310         free(decoder);
 311 }
 312
 313 static int intel_pt_ext_err(int code)
 314 {
 315         switch (code) {
 316         case -ENOMEM:
 317                 return INTEL_PT_ERR_NOMEM;
 318         case -ENOSYS:
 319                 return INTEL_PT_ERR_INTERN;
 320         case -EBADMSG:
 321                 return INTEL_PT_ERR_BADPKT;
 322         case -ENODATA:
 323                 return INTEL_PT_ERR_NODATA;
 324         case -EILSEQ:
 325                 return INTEL_PT_ERR_NOINSN;
 326         case -ENOENT:
 327                 return INTEL_PT_ERR_MISMAT;
 328         case -EOVERFLOW:
 329                 return INTEL_PT_ERR_OVR;
 330         case -ENOSPC:
 331                 return INTEL_PT_ERR_LOST;
 332         case -ELOOP:
 333                 return INTEL_PT_ERR_NELOOP;
 334         default:
 335                 return INTEL_PT_ERR_UNK;
 336         }
 337 }
 338
 339 static const char *intel_pt_err_msgs[] = {
 340         [INTEL_PT_ERR_NOMEM]  = "Memory allocation failed",
 341         [INTEL_PT_ERR_INTERN] = "Internal error",
 342         [INTEL_PT_ERR_BADPKT] = "Bad packet",
 343         [INTEL_PT_ERR_NODATA] = "No more data",
 344         [INTEL_PT_ERR_NOINSN] = "Failed to get instruction",
 345         [INTEL_PT_ERR_MISMAT] = "Trace doesn't match instruction",
 346         [INTEL_PT_ERR_OVR]    = "Overflow packet",
 347         [INTEL_PT_ERR_LOST]   = "Lost trace data",
 348         [INTEL_PT_ERR_UNK]    = "Unknown error!",
 349         [INTEL_PT_ERR_NELOOP] = "Never-ending loop",
 350 };
 351
 352 int intel_pt__strerror(int code, char *buf, size_t buflen)
 353 {
 354         if (code < 1 || code >= INTEL_PT_ERR_MAX)
 355                 code = INTEL_PT_ERR_UNK;
 356         strlcpy(buf, intel_pt_err_msgs[code], buflen);
 357         return 0;
 358 }
 359
 360 static uint64_t intel_pt_calc_ip(const struct intel_pt_pkt *packet,
 361                                  uint64_t last_ip)
 362 {
 363         uint64_t ip;
 364
 365         switch (packet->count) {
 366         case 1:
 367                 ip = (last_ip & (uint64_t)0xffffffffffff0000ULL) |
 368                      packet->payload;
 369                 break;
 370         case 2:
 371                 ip = (last_ip & (uint64_t)0xffffffff00000000ULL) |
 372                      packet->payload;
 373                 break;
 374         case 3:
 375                 ip = packet->payload;
 376                 /* Sign-extend 6-byte ip */
 377                 if (ip & (uint64_t)0x800000000000ULL)
 378                         ip |= (uint64_t)0xffff000000000000ULL;
 379                 break;
 380         case 4:
 381                 ip = (last_ip & (uint64_t)0xffff000000000000ULL) |
 382                      packet->payload;
 383                 break;
 384         case 6:
 385                 ip = packet->payload;
 386                 break;
 387         default:
 388                 return 0;
 389         }
 390
 391         return ip;
 392 }
 393
 394 static inline void intel_pt_set_last_ip(struct intel_pt_decoder *decoder)
 395 {
 396         decoder->last_ip = intel_pt_calc_ip(&decoder->packet, decoder->last_ip);
 397 }
 398
 399 static inline void intel_pt_set_ip(struct intel_pt_decoder *decoder)
 400 {
 401         intel_pt_set_last_ip(decoder);
 402         decoder->ip = decoder->last_ip;
 403 }
 404
 405 static void intel_pt_decoder_log_packet(struct intel_pt_decoder *decoder)
 406 {
 407         intel_pt_log_packet(&decoder->packet, decoder->pkt_len, decoder->pos,
 408                             decoder->buf);
 409 }
 410
 411 static int intel_pt_bug(struct intel_pt_decoder *decoder)
 412 {
 413         intel_pt_log("ERROR: Internal error\n");
 414         decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
 415         return -ENOSYS;
 416 }
 417
 418 static inline void intel_pt_clear_tx_flags(struct intel_pt_decoder *decoder)
 419 {
 420         decoder->tx_flags = 0;
 421 }
 422
 423 static inline void intel_pt_update_in_tx(struct intel_pt_decoder *decoder)
 424 {
 425         decoder->tx_flags = decoder->packet.payload & INTEL_PT_IN_TX;
 426 }
 427
 428 static int intel_pt_bad_packet(struct intel_pt_decoder *decoder)
 429 {
 430         intel_pt_clear_tx_flags(decoder);
 431         decoder->have_tma = false;
 432         decoder->pkt_len = 1;
 433         decoder->pkt_step = 1;
 434         intel_pt_decoder_log_packet(decoder);
 435         if (decoder->pkt_state != INTEL_PT_STATE_NO_PSB) {
 436                 intel_pt_log("ERROR: Bad packet\n");
 437                 decoder->pkt_state = INTEL_PT_STATE_ERR1;
 438         }
 439         return -EBADMSG;
 440 }
 441
 442 static int intel_pt_get_data(struct intel_pt_decoder *decoder)
 443 {
 444         struct intel_pt_buffer buffer = { .buf = 0, };
 445         int ret;
 446
 447         decoder->pkt_step = 0;
 448
 449         intel_pt_log("Getting more data\n");
 450         ret = decoder->get_trace(&buffer, decoder->data);
 451         if (ret)
 452                 return ret;
 453         decoder->buf = buffer.buf;
 454         decoder->len = buffer.len;
 455         if (!decoder->len) {
 456                 intel_pt_log("No more data\n");
 457                 return -ENODATA;
 458         }
 459         if (!buffer.consecutive) {
 460                 decoder->ip = 0;
 461                 decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
 462                 decoder->ref_timestamp = buffer.ref_timestamp;
 463                 decoder->timestamp = 0;
 464                 decoder->have_tma = false;
 465                 decoder->state.trace_nr = buffer.trace_nr;
 466                 intel_pt_log("Reference timestamp 0x%" PRIx64 "\n",
 467                              decoder->ref_timestamp);
 468                 return -ENOLINK;
 469         }
 470
 471         return 0;
 472 }
 473
 474 static int intel_pt_get_next_data(struct intel_pt_decoder *decoder)
 475 {
 476         if (!decoder->next_buf)
 477                 return intel_pt_get_data(decoder);
 478
 479         decoder->buf = decoder->next_buf;
 480         decoder->len = decoder->next_len;
 481         decoder->next_buf = 0;
 482         decoder->next_len = 0;
 483         return 0;
 484 }
 485
 486 static int intel_pt_get_split_packet(struct intel_pt_decoder *decoder)
 487 {
 488         unsigned char *buf = decoder->temp_buf;
 489         size_t old_len, len, n;
 490         int ret;
 491
 492         old_len = decoder->len;
 493         len = decoder->len;
 494         memcpy(buf, decoder->buf, len);
 495
 496         ret = intel_pt_get_data(decoder);
 497         if (ret) {
 498                 decoder->pos += old_len;
 499                 return ret < 0 ? ret : -EINVAL;
 500         }
 501
 502         n = INTEL_PT_PKT_MAX_SZ - len;
 503         if (n > decoder->len)
 504                 n = decoder->len;
 505         memcpy(buf + len, decoder->buf, n);
 506         len += n;
 507
 508         ret = intel_pt_get_packet(buf, len, &decoder->packet);
 509         if (ret < (int)old_len) {
 510                 decoder->next_buf = decoder->buf;
 511                 decoder->next_len = decoder->len;
 512                 decoder->buf = buf;
 513                 decoder->len = old_len;
 514                 return intel_pt_bad_packet(decoder);
 515         }
 516
 517         decoder->next_buf = decoder->buf + (ret - old_len);
 518         decoder->next_len = decoder->len - (ret - old_len);
 519
 520         decoder->buf = buf;
 521         decoder->len = ret;
 522
 523         return ret;
 524 }
 525
 526 struct intel_pt_pkt_info {
 527         struct intel_pt_decoder   *decoder;
 528         struct intel_pt_pkt       packet;
 529         uint64_t                  pos;
 530         int                       pkt_len;
 531         int                       last_packet_type;
 532         void                      *data;
 533 };
 534
 535 typedef int (*intel_pt_pkt_cb_t)(struct intel_pt_pkt_info *pkt_info);
 536
 537 /* Lookahead packets in current buffer */
 538 static int intel_pt_pkt_lookahead(struct intel_pt_decoder *decoder,
 539                                   intel_pt_pkt_cb_t cb, void *data)
 540 {
 541         struct intel_pt_pkt_info pkt_info;
 542         const unsigned char *buf = decoder->buf;
 543         size_t len = decoder->len;
 544         int ret;
 545
 546         pkt_info.decoder          = decoder;
 547         pkt_info.pos              = decoder->pos;
 548         pkt_info.pkt_len          = decoder->pkt_step;
 549         pkt_info.last_packet_type = decoder->last_packet_type;
 550         pkt_info.data             = data;
 551
 552         while (1) {
 553                 do {
 554                         pkt_info.pos += pkt_info.pkt_len;
 555                         buf          += pkt_info.pkt_len;
 556                         len          -= pkt_info.pkt_len;
 557
 558                         if (!len)
 559                                 return INTEL_PT_NEED_MORE_BYTES;
 560
 561                         ret = intel_pt_get_packet(buf, len, &pkt_info.packet);
 562                         if (!ret)
 563                                 return INTEL_PT_NEED_MORE_BYTES;
 564                         if (ret < 0)
 565                                 return ret;
 566
 567                         pkt_info.pkt_len = ret;
 568                 } while (pkt_info.packet.type == INTEL_PT_PAD);
 569
 570                 ret = cb(&pkt_info);
 571                 if (ret)
 572                         return 0;
 573
 574                 pkt_info.last_packet_type = pkt_info.packet.type;
 575         }
 576 }
 577
 578 struct intel_pt_calc_cyc_to_tsc_info {
 579         uint64_t        cycle_cnt;
 580         unsigned int    cbr;
 581         uint32_t        last_mtc;
 582         uint64_t        ctc_timestamp;
 583         uint64_t        ctc_delta;
 584         uint64_t        tsc_timestamp;
 585         uint64_t        timestamp;
 586         bool            have_tma;
 587         bool            from_mtc;
 588         double          cbr_cyc_to_tsc;
 589 };
 590
 591 static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
 592 {
 593         struct intel_pt_decoder *decoder = pkt_info->decoder;
 594         struct intel_pt_calc_cyc_to_tsc_info *data = pkt_info->data;
 595         uint64_t timestamp;
 596         double cyc_to_tsc;
 597         unsigned int cbr;
 598         uint32_t mtc, mtc_delta, ctc, fc, ctc_rem;
 599
 600         switch (pkt_info->packet.type) {
 601         case INTEL_PT_TNT:
 602         case INTEL_PT_TIP_PGE:
 603         case INTEL_PT_TIP:
 604         case INTEL_PT_FUP:
 605         case INTEL_PT_PSB:
 606         case INTEL_PT_PIP:
 607         case INTEL_PT_MODE_EXEC:
 608         case INTEL_PT_MODE_TSX:
 609         case INTEL_PT_PSBEND:
 610         case INTEL_PT_PAD:
 611         case INTEL_PT_VMCS:
 612         case INTEL_PT_MNT:
 613                 return 0;
 614
 615         case INTEL_PT_MTC:
 616                 if (!data->have_tma)
 617                         return 0;
 618
 619                 mtc = pkt_info->packet.payload;
 620                 if (mtc > data->last_mtc)
 621                         mtc_delta = mtc - data->last_mtc;
 622                 else
 623                         mtc_delta = mtc + 256 - data->last_mtc;
 624                 data->ctc_delta += mtc_delta << decoder->mtc_shift;
 625                 data->last_mtc = mtc;
 626
 627                 if (decoder->tsc_ctc_mult) {
 628                         timestamp = data->ctc_timestamp +
 629                                 data->ctc_delta * decoder->tsc_ctc_mult;
 630                 } else {
 631                         timestamp = data->ctc_timestamp +
 632                                 multdiv(data->ctc_delta,
 633                                         decoder->tsc_ctc_ratio_n,
 634                                         decoder->tsc_ctc_ratio_d);
 635                 }
 636
 637                 if (timestamp < data->timestamp)
 638                         return 1;
 639
 640                 if (pkt_info->last_packet_type != INTEL_PT_CYC) {
 641                         data->timestamp = timestamp;
 642                         return 0;
 643                 }
 644
 645                 break;
 646
 647         case INTEL_PT_TSC:
 648                 timestamp = pkt_info->packet.payload |
 649                             (data->timestamp & (0xffULL << 56));
 650                 if (data->from_mtc && timestamp < data->timestamp &&
 651                     data->timestamp - timestamp < decoder->tsc_slip)
 652                         return 1;
 653                 if (timestamp < data->timestamp)
 654                         timestamp += (1ULL << 56);
 655                 if (pkt_info->last_packet_type != INTEL_PT_CYC) {
 656                         if (data->from_mtc)
 657                                 return 1;
 658                         data->tsc_timestamp = timestamp;
 659                         data->timestamp = timestamp;
 660                         return 0;
 661                 }
 662                 break;
 663
 664         case INTEL_PT_TMA:
 665                 if (data->from_mtc)
 666                         return 1;
 667
 668                 if (!decoder->tsc_ctc_ratio_d)
 669                         return 0;
 670
 671                 ctc = pkt_info->packet.payload;
 672                 fc = pkt_info->packet.count;
 673                 ctc_rem = ctc & decoder->ctc_rem_mask;
 674
 675                 data->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
 676
 677                 data->ctc_timestamp = data->tsc_timestamp - fc;
 678                 if (decoder->tsc_ctc_mult) {
 679                         data->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
 680                 } else {
 681                         data->ctc_timestamp -=
 682                                 multdiv(ctc_rem, decoder->tsc_ctc_ratio_n,
 683                                         decoder->tsc_ctc_ratio_d);
 684                 }
 685
 686                 data->ctc_delta = 0;
 687                 data->have_tma = true;
 688
 689                 return 0;
 690
 691         case INTEL_PT_CYC:
 692                 data->cycle_cnt += pkt_info->packet.payload;
 693                 return 0;
 694
 695         case INTEL_PT_CBR:
 696                 cbr = pkt_info->packet.payload;
 697                 if (data->cbr && data->cbr != cbr)
 698                         return 1;
 699                 data->cbr = cbr;
 700                 data->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
 701                 return 0;
 702
 703         case INTEL_PT_TIP_PGD:
 704         case INTEL_PT_TRACESTOP:
 705         case INTEL_PT_OVF:
 706         case INTEL_PT_BAD: /* Does not happen */
 707         default:
 708                 return 1;
 709         }
 710
 711         if (!data->cbr && decoder->cbr) {
 712                 data->cbr = decoder->cbr;
 713                 data->cbr_cyc_to_tsc = decoder->cbr_cyc_to_tsc;
 714         }
 715
 716         if (!data->cycle_cnt)
 717                 return 1;
 718
 719         cyc_to_tsc = (double)(timestamp - decoder->timestamp) / data->cycle_cnt;
 720
 721         if (data->cbr && cyc_to_tsc > data->cbr_cyc_to_tsc &&
 722             cyc_to_tsc / data->cbr_cyc_to_tsc > 1.25) {
 723                 intel_pt_log("Timestamp: calculated %g TSC ticks per cycle too big (c.f. CBR-based value %g), pos " x64_fmt "\n",
 724                              cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
 725                 return 1;
 726         }
 727
 728         decoder->calc_cyc_to_tsc = cyc_to_tsc;
 729         decoder->have_calc_cyc_to_tsc = true;
 730
 731         if (data->cbr) {
 732                 intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. CBR-based value %g, pos " x64_fmt "\n",
 733                              cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
 734         } else {
 735                 intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. unknown CBR-based value, pos " x64_fmt "\n",
 736                              cyc_to_tsc, pkt_info->pos);
 737         }
 738
 739         return 1;
 740 }
 741
 742 static void intel_pt_calc_cyc_to_tsc(struct intel_pt_decoder *decoder,
 743                                      bool from_mtc)
 744 {
 745         struct intel_pt_calc_cyc_to_tsc_info data = {
 746                 .cycle_cnt      = 0,
 747                 .cbr            = 0,
 748                 .last_mtc       = decoder->last_mtc,
 749                 .ctc_timestamp  = decoder->ctc_timestamp,
 750                 .ctc_delta      = decoder->ctc_delta,
 751                 .tsc_timestamp  = decoder->tsc_timestamp,
 752                 .timestamp      = decoder->timestamp,
 753                 .have_tma       = decoder->have_tma,
 754                 .from_mtc       = from_mtc,
 755                 .cbr_cyc_to_tsc = 0,
 756         };
 757
 758         intel_pt_pkt_lookahead(decoder, intel_pt_calc_cyc_cb, &data);
 759 }
 760
 761 static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder)
 762 {
 763         int ret;
 764
 765         decoder->last_packet_type = decoder->packet.type;
 766
 767         do {
 768                 decoder->pos += decoder->pkt_step;
 769                 decoder->buf += decoder->pkt_step;
 770                 decoder->len -= decoder->pkt_step;
 771
 772                 if (!decoder->len) {
 773                         ret = intel_pt_get_next_data(decoder);
 774                         if (ret)
 775                                 return ret;
 776                 }
 777
 778                 ret = intel_pt_get_packet(decoder->buf, decoder->len,
 779                                           &decoder->packet);
 780                 if (ret == INTEL_PT_NEED_MORE_BYTES &&
 781                     decoder->len < INTEL_PT_PKT_MAX_SZ && !decoder->next_buf) {
 782                         ret = intel_pt_get_split_packet(decoder);
 783                         if (ret < 0)
 784                                 return ret;
 785                 }
 786                 if (ret <= 0)
 787                         return intel_pt_bad_packet(decoder);
 788
 789                 decoder->pkt_len = ret;
 790                 decoder->pkt_step = ret;
 791                 intel_pt_decoder_log_packet(decoder);
 792         } while (decoder->packet.type == INTEL_PT_PAD);
 793
 794         return 0;
 795 }
 796
 797 static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder)
 798 {
 799         uint64_t timestamp, masked_timestamp;
 800
 801         timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
 802         masked_timestamp = timestamp & decoder->period_mask;
 803         if (decoder->continuous_period) {
 804                 if (masked_timestamp != decoder->last_masked_timestamp)
 805                         return 1;
 806         } else {
 807                 timestamp += 1;
 808                 masked_timestamp = timestamp & decoder->period_mask;
 809                 if (masked_timestamp != decoder->last_masked_timestamp) {
 810                         decoder->last_masked_timestamp = masked_timestamp;
 811                         decoder->continuous_period = true;
 812                 }
 813         }
 814         return decoder->period_ticks - (timestamp - masked_timestamp);
 815 }
 816
 817 static uint64_t intel_pt_next_sample(struct intel_pt_decoder *decoder)
 818 {
 819         switch (decoder->period_type) {
 820         case INTEL_PT_PERIOD_INSTRUCTIONS:
 821                 return decoder->period - decoder->period_insn_cnt;
 822         case INTEL_PT_PERIOD_TICKS:
 823                 return intel_pt_next_period(decoder);
 824         case INTEL_PT_PERIOD_NONE:
 825         case INTEL_PT_PERIOD_MTC:
 826         default:
 827                 return 0;
 828         }
 829 }
 830
 831 static void intel_pt_sample_insn(struct intel_pt_decoder *decoder)
 832 {
 833         uint64_t timestamp, masked_timestamp;
 834
 835         switch (decoder->period_type) {
 836         case INTEL_PT_PERIOD_INSTRUCTIONS:
 837                 decoder->period_insn_cnt = 0;
 838                 break;
 839         case INTEL_PT_PERIOD_TICKS:
 840                 timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
 841                 masked_timestamp = timestamp & decoder->period_mask;
 842                 decoder->last_masked_timestamp = masked_timestamp;
 843                 break;
 844         case INTEL_PT_PERIOD_NONE:
 845         case INTEL_PT_PERIOD_MTC:
 846         default:
 847                 break;
 848         }
 849
 850         decoder->state.type |= INTEL_PT_INSTRUCTION;
 851 }
 852
 853 static int intel_pt_walk_insn(struct intel_pt_decoder *decoder,
 854                               struct intel_pt_insn *intel_pt_insn, uint64_t ip)
 855 {
 856         uint64_t max_insn_cnt, insn_cnt = 0;
 857         int err;
 858
 859         if (!decoder->mtc_insn)
 860                 decoder->mtc_insn = true;
 861
 862         max_insn_cnt = intel_pt_next_sample(decoder);
 863
 864         err = decoder->walk_insn(intel_pt_insn, &insn_cnt, &decoder->ip, ip,
 865                                  max_insn_cnt, decoder->data);
 866
 867         decoder->tot_insn_cnt += insn_cnt;
 868         decoder->timestamp_insn_cnt += insn_cnt;
 869         decoder->period_insn_cnt += insn_cnt;
 870
 871         if (err) {
 872                 decoder->no_progress = 0;
 873                 decoder->pkt_state = INTEL_PT_STATE_ERR2;
 874                 intel_pt_log_at("ERROR: Failed to get instruction",
 875                                 decoder->ip);
 876                 if (err == -ENOENT)
 877                         return -ENOLINK;
 878                 return -EILSEQ;
 879         }
 880
 881         if (ip && decoder->ip == ip) {
 882                 err = -EAGAIN;
 883                 goto out;
 884         }
 885
 886         if (max_insn_cnt && insn_cnt >= max_insn_cnt)
 887                 intel_pt_sample_insn(decoder);
 888
 889         if (intel_pt_insn->branch == INTEL_PT_BR_NO_BRANCH) {
 890                 decoder->state.type = INTEL_PT_INSTRUCTION;
 891                 decoder->state.from_ip = decoder->ip;
 892                 decoder->state.to_ip = 0;
 893                 decoder->ip += intel_pt_insn->length;
 894                 err = INTEL_PT_RETURN;
 895                 goto out;
 896         }
 897
 898         if (intel_pt_insn->op == INTEL_PT_OP_CALL) {
 899                 /* Zero-length calls are excluded */
 900                 if (intel_pt_insn->branch != INTEL_PT_BR_UNCONDITIONAL ||
 901                     intel_pt_insn->rel) {
 902                         err = intel_pt_push(&decoder->stack, decoder->ip +
 903                                             intel_pt_insn->length);
 904                         if (err)
 905                                 goto out;
 906                 }
 907         } else if (intel_pt_insn->op == INTEL_PT_OP_RET) {
 908                 decoder->ret_addr = intel_pt_pop(&decoder->stack);
 909         }
 910
 911         if (intel_pt_insn->branch == INTEL_PT_BR_UNCONDITIONAL) {
 912                 int cnt = decoder->no_progress++;
 913
 914                 decoder->state.from_ip = decoder->ip;
 915                 decoder->ip += intel_pt_insn->length +
 916                                 intel_pt_insn->rel;
 917                 decoder->state.to_ip = decoder->ip;
 918                 err = INTEL_PT_RETURN;
 919
 920                 /*
 921                  * Check for being stuck in a loop.  This can happen if a
 922                  * decoder error results in the decoder erroneously setting the
 923                  * ip to an address that is itself in an infinite loop that
 924                  * consumes no packets.  When that happens, there must be an
 925                  * unconditional branch.
 926                  */
 927                 if (cnt) {
 928                         if (cnt == 1) {
 929                                 decoder->stuck_ip = decoder->state.to_ip;
 930                                 decoder->stuck_ip_prd = 1;
 931                                 decoder->stuck_ip_cnt = 1;
 932                         } else if (cnt > INTEL_PT_MAX_LOOPS ||
 933                                    decoder->state.to_ip == decoder->stuck_ip) {
 934                                 intel_pt_log_at("ERROR: Never-ending loop",
 935                                                 decoder->state.to_ip);
 936                                 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
 937                                 err = -ELOOP;
 938                                 goto out;
 939                         } else if (!--decoder->stuck_ip_cnt) {
 940                                 decoder->stuck_ip_prd += 1;
 941                                 decoder->stuck_ip_cnt = decoder->stuck_ip_prd;
 942                                 decoder->stuck_ip = decoder->state.to_ip;
 943                         }
 944                 }
 945                 goto out_no_progress;
 946         }
 947 out:
 948         decoder->no_progress = 0;
 949 out_no_progress:
 950         decoder->state.insn_op = intel_pt_insn->op;
 951         decoder->state.insn_len = intel_pt_insn->length;
 952
 953         if (decoder->tx_flags & INTEL_PT_IN_TX)
 954                 decoder->state.flags |= INTEL_PT_IN_TX;
 955
 956         return err;
 957 }
 958
 959 static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
 960 {
 961         struct intel_pt_insn intel_pt_insn;
 962         uint64_t ip;
 963         int err;
 964
 965         ip = decoder->last_ip;
 966
 967         while (1) {
 968                 err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip);
 969                 if (err == INTEL_PT_RETURN)
 970                         return 0;
 971                 if (err == -EAGAIN) {
 972                         if (decoder->set_fup_tx_flags) {
 973                                 decoder->set_fup_tx_flags = false;
 974                                 decoder->tx_flags = decoder->fup_tx_flags;
 975                                 decoder->state.type = INTEL_PT_TRANSACTION;
 976                                 decoder->state.from_ip = decoder->ip;
 977                                 decoder->state.to_ip = 0;
 978                                 decoder->state.flags = decoder->fup_tx_flags;
 979                                 return 0;
 980                         }
 981                         return err;
 982                 }
 983                 decoder->set_fup_tx_flags = false;
 984                 if (err)
 985                         return err;
 986
 987                 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
 988                         intel_pt_log_at("ERROR: Unexpected indirect branch",
 989                                         decoder->ip);
 990                         decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
 991                         return -ENOENT;
 992                 }
 993
 994                 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
 995                         intel_pt_log_at("ERROR: Unexpected conditional branch",
 996                                         decoder->ip);
 997                         decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
 998                         return -ENOENT;
 999                 }
1000
1001                 intel_pt_bug(decoder);
1002         }
1003 }
1004
1005 static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
1006 {
1007         struct intel_pt_insn intel_pt_insn;
1008         int err;
1009
1010         err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1011         if (err == INTEL_PT_RETURN)
1012                 return 0;
1013         if (err)
1014                 return err;
1015
1016         if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1017                 if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) {
1018                         decoder->pge = false;
1019                         decoder->continuous_period = false;
1020                         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1021                         decoder->state.from_ip = decoder->ip;
1022                         decoder->state.to_ip = 0;
1023                         if (decoder->packet.count != 0)
1024                                 decoder->ip = decoder->last_ip;
1025                 } else {
1026                         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1027                         decoder->state.from_ip = decoder->ip;
1028                         if (decoder->packet.count == 0) {
1029                                 decoder->state.to_ip = 0;
1030                         } else {
1031                                 decoder->state.to_ip = decoder->last_ip;
1032                                 decoder->ip = decoder->last_ip;
1033                         }
1034                 }
1035                 return 0;
1036         }
1037
1038         if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1039                 intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch",
1040                                 decoder->ip);
1041                 decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1042                 return -ENOENT;
1043         }
1044
1045         return intel_pt_bug(decoder);
1046 }
1047
1048 static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
1049 {
1050         struct intel_pt_insn intel_pt_insn;
1051         int err;
1052
1053         while (1) {
1054                 err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1055                 if (err == INTEL_PT_RETURN)
1056                         return 0;
1057                 if (err)
1058                         return err;
1059
1060                 if (intel_pt_insn.op == INTEL_PT_OP_RET) {
1061                         if (!decoder->return_compression) {
1062                                 intel_pt_log_at("ERROR: RET when expecting conditional branch",
1063                                                 decoder->ip);
1064                                 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1065                                 return -ENOENT;
1066                         }
1067                         if (!decoder->ret_addr) {
1068                                 intel_pt_log_at("ERROR: Bad RET compression (stack empty)",
1069                                                 decoder->ip);
1070                                 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1071                                 return -ENOENT;
1072                         }
1073                         if (!(decoder->tnt.payload & BIT63)) {
1074                                 intel_pt_log_at("ERROR: Bad RET compression (TNT=N)",
1075                                                 decoder->ip);
1076                                 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1077                                 return -ENOENT;
1078                         }
1079                         decoder->tnt.count -= 1;
1080                         if (!decoder->tnt.count)
1081                                 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1082                         decoder->tnt.payload <<= 1;
1083                         decoder->state.from_ip = decoder->ip;
1084                         decoder->ip = decoder->ret_addr;
1085                         decoder->state.to_ip = decoder->ip;
1086                         return 0;
1087                 }
1088
1089                 if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1090                         /* Handle deferred TIPs */
1091                         err = intel_pt_get_next_packet(decoder);
1092                         if (err)
1093                                 return err;
1094                         if (decoder->packet.type != INTEL_PT_TIP ||
1095                             decoder->packet.count == 0) {
1096                                 intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch",
1097                                                 decoder->ip);
1098                                 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1099                                 decoder->pkt_step = 0;
1100                                 return -ENOENT;
1101                         }
1102                         intel_pt_set_last_ip(decoder);
1103                         decoder->state.from_ip = decoder->ip;
1104                         decoder->state.to_ip = decoder->last_ip;
1105                         decoder->ip = decoder->last_ip;
1106                         return 0;
1107                 }
1108
1109                 if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1110                         decoder->tnt.count -= 1;
1111                         if (!decoder->tnt.count)
1112                                 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1113                         if (decoder->tnt.payload & BIT63) {
1114                                 decoder->tnt.payload <<= 1;
1115                                 decoder->state.from_ip = decoder->ip;
1116                                 decoder->ip += intel_pt_insn.length +
1117                                                intel_pt_insn.rel;
1118                                 decoder->state.to_ip = decoder->ip;
1119                                 return 0;
1120                         }
1121                         /* Instruction sample for a non-taken branch */
1122                         if (decoder->state.type & INTEL_PT_INSTRUCTION) {
1123                                 decoder->tnt.payload <<= 1;
1124                                 decoder->state.type = INTEL_PT_INSTRUCTION;
1125                                 decoder->state.from_ip = decoder->ip;
1126                                 decoder->state.to_ip = 0;
1127                                 decoder->ip += intel_pt_insn.length;
1128                                 return 0;
1129                         }
1130                         decoder->ip += intel_pt_insn.length;
1131                         if (!decoder->tnt.count)
1132                                 return -EAGAIN;
1133                         decoder->tnt.payload <<= 1;
1134                         continue;
1135                 }
1136
1137                 return intel_pt_bug(decoder);
1138         }
1139 }
1140
1141 static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
1142 {
1143         unsigned int fup_tx_flags;
1144         int err;
1145
1146         fup_tx_flags = decoder->packet.payload &
1147                        (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX);
1148         err = intel_pt_get_next_packet(decoder);
1149         if (err)
1150                 return err;
1151         if (decoder->packet.type == INTEL_PT_FUP) {
1152                 decoder->fup_tx_flags = fup_tx_flags;
1153                 decoder->set_fup_tx_flags = true;
1154                 if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX))
1155                         *no_tip = true;
1156         } else {
1157                 intel_pt_log_at("ERROR: Missing FUP after MODE.TSX",
1158                                 decoder->pos);
1159                 intel_pt_update_in_tx(decoder);
1160         }
1161         return 0;
1162 }
1163
1164 static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
1165 {
1166         uint64_t timestamp;
1167
1168         decoder->have_tma = false;
1169
1170         if (decoder->ref_timestamp) {
1171                 timestamp = decoder->packet.payload |
1172                             (decoder->ref_timestamp & (0xffULL << 56));
1173                 if (timestamp < decoder->ref_timestamp) {
1174                         if (decoder->ref_timestamp - timestamp > (1ULL << 55))
1175                                 timestamp += (1ULL << 56);
1176                 } else {
1177                         if (timestamp - decoder->ref_timestamp > (1ULL << 55))
1178                                 timestamp -= (1ULL << 56);
1179                 }
1180                 decoder->tsc_timestamp = timestamp;
1181                 decoder->timestamp = timestamp;
1182                 decoder->ref_timestamp = 0;
1183                 decoder->timestamp_insn_cnt = 0;
1184         } else if (decoder->timestamp) {
1185                 timestamp = decoder->packet.payload |
1186                             (decoder->timestamp & (0xffULL << 56));
1187                 decoder->tsc_timestamp = timestamp;
1188                 if (timestamp < decoder->timestamp &&
1189                     decoder->timestamp - timestamp < decoder->tsc_slip) {
1190                         intel_pt_log_to("Suppressing backwards timestamp",
1191                                         timestamp);
1192                         timestamp = decoder->timestamp;
1193                 }
1194                 if (timestamp < decoder->timestamp) {
1195                         intel_pt_log_to("Wraparound timestamp", timestamp);
1196                         timestamp += (1ULL << 56);
1197                         decoder->tsc_timestamp = timestamp;
1198                 }
1199                 decoder->timestamp = timestamp;
1200                 decoder->timestamp_insn_cnt = 0;
1201         }
1202
1203         if (decoder->last_packet_type == INTEL_PT_CYC) {
1204                 decoder->cyc_ref_timestamp = decoder->timestamp;
1205                 decoder->cycle_cnt = 0;
1206                 decoder->have_calc_cyc_to_tsc = false;
1207                 intel_pt_calc_cyc_to_tsc(decoder, false);
1208         }
1209
1210         intel_pt_log_to("Setting timestamp", decoder->timestamp);
1211 }
1212
1213 static int intel_pt_overflow(struct intel_pt_decoder *decoder)
1214 {
1215         intel_pt_log("ERROR: Buffer overflow\n");
1216         intel_pt_clear_tx_flags(decoder);
1217         decoder->have_tma = false;
1218         decoder->cbr = 0;
1219         decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1220         decoder->overflow = true;
1221         return -EOVERFLOW;
1222 }
1223
1224 static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
1225 {
1226         uint32_t ctc = decoder->packet.payload;
1227         uint32_t fc = decoder->packet.count;
1228         uint32_t ctc_rem = ctc & decoder->ctc_rem_mask;
1229
1230         if (!decoder->tsc_ctc_ratio_d)
1231                 return;
1232
1233         decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
1234         decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
1235         if (decoder->tsc_ctc_mult) {
1236                 decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
1237         } else {
1238                 decoder->ctc_timestamp -= multdiv(ctc_rem,
1239                                                   decoder->tsc_ctc_ratio_n,
1240                                                   decoder->tsc_ctc_ratio_d);
1241         }
1242         decoder->ctc_delta = 0;
1243         decoder->have_tma = true;
1244         intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x  CTC rem %#x\n",
1245                      decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
1246 }
1247
1248 static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
1249 {
1250         uint64_t timestamp;
1251         uint32_t mtc, mtc_delta;
1252
1253         if (!decoder->have_tma)
1254                 return;
1255
1256         mtc = decoder->packet.payload;
1257
1258         if (mtc > decoder->last_mtc)
1259                 mtc_delta = mtc - decoder->last_mtc;
1260         else
1261                 mtc_delta = mtc + 256 - decoder->last_mtc;
1262
1263         decoder->ctc_delta += mtc_delta << decoder->mtc_shift;
1264
1265         if (decoder->tsc_ctc_mult) {
1266                 timestamp = decoder->ctc_timestamp +
1267                             decoder->ctc_delta * decoder->tsc_ctc_mult;
1268         } else {
1269                 timestamp = decoder->ctc_timestamp +
1270                             multdiv(decoder->ctc_delta,
1271                                     decoder->tsc_ctc_ratio_n,
1272                                     decoder->tsc_ctc_ratio_d);
1273         }
1274
1275         if (timestamp < decoder->timestamp)
1276                 intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
1277                              timestamp, decoder->timestamp);
1278         else
1279                 decoder->timestamp = timestamp;
1280
1281         decoder->timestamp_insn_cnt = 0;
1282         decoder->last_mtc = mtc;
1283
1284         if (decoder->last_packet_type == INTEL_PT_CYC) {
1285                 decoder->cyc_ref_timestamp = decoder->timestamp;
1286                 decoder->cycle_cnt = 0;
1287                 decoder->have_calc_cyc_to_tsc = false;
1288                 intel_pt_calc_cyc_to_tsc(decoder, true);
1289         }
1290 }
1291
1292 static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)
1293 {
1294         unsigned int cbr = decoder->packet.payload;
1295
1296         if (decoder->cbr == cbr)
1297                 return;
1298
1299         decoder->cbr = cbr;
1300         decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
1301 }
1302
1303 static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
1304 {
1305         uint64_t timestamp = decoder->cyc_ref_timestamp;
1306
1307         decoder->have_cyc = true;
1308
1309         decoder->cycle_cnt += decoder->packet.payload;
1310
1311         if (!decoder->cyc_ref_timestamp)
1312                 return;
1313
1314         if (decoder->have_calc_cyc_to_tsc)
1315                 timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc;
1316         else if (decoder->cbr)
1317                 timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc;
1318         else
1319                 return;
1320
1321         if (timestamp < decoder->timestamp)
1322                 intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
1323                              timestamp, decoder->timestamp);
1324         else
1325                 decoder->timestamp = timestamp;
1326 }
1327
1328 /* Walk PSB+ packets when already in sync. */
1329 static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
1330 {
1331         int err;
1332
1333         while (1) {
1334                 err = intel_pt_get_next_packet(decoder);
1335                 if (err)
1336                         return err;
1337
1338                 switch (decoder->packet.type) {
1339                 case INTEL_PT_PSBEND:
1340                         return 0;
1341
1342                 case INTEL_PT_TIP_PGD:
1343                 case INTEL_PT_TIP_PGE:
1344                 case INTEL_PT_TIP:
1345                 case INTEL_PT_TNT:
1346                 case INTEL_PT_TRACESTOP:
1347                 case INTEL_PT_BAD:
1348                 case INTEL_PT_PSB:
1349                         decoder->have_tma = false;
1350                         intel_pt_log("ERROR: Unexpected packet\n");
1351                         return -EAGAIN;
1352
1353                 case INTEL_PT_OVF:
1354                         return intel_pt_overflow(decoder);
1355
1356                 case INTEL_PT_TSC:
1357                         intel_pt_calc_tsc_timestamp(decoder);
1358                         break;
1359
1360                 case INTEL_PT_TMA:
1361                         intel_pt_calc_tma(decoder);
1362                         break;
1363
1364                 case INTEL_PT_CBR:
1365                         intel_pt_calc_cbr(decoder);
1366                         break;
1367
1368                 case INTEL_PT_MODE_EXEC:
1369                         decoder->exec_mode = decoder->packet.payload;
1370                         break;
1371
1372                 case INTEL_PT_PIP:
1373                         decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1374                         break;
1375
1376                 case INTEL_PT_FUP:
1377                         decoder->pge = true;
1378                         intel_pt_set_last_ip(decoder);
1379                         break;
1380
1381                 case INTEL_PT_MODE_TSX:
1382                         intel_pt_update_in_tx(decoder);
1383                         break;
1384
1385                 case INTEL_PT_MTC:
1386                         intel_pt_calc_mtc_timestamp(decoder);
1387                         if (decoder->period_type == INTEL_PT_PERIOD_MTC)
1388                                 decoder->state.type |= INTEL_PT_INSTRUCTION;
1389                         break;
1390
1391                 case INTEL_PT_CYC:
1392                 case INTEL_PT_VMCS:
1393                 case INTEL_PT_MNT:
1394                 case INTEL_PT_PAD:
1395                 default:
1396                         break;
1397                 }
1398         }
1399 }
1400
1401 static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
1402 {
1403         int err;
1404
1405         if (decoder->tx_flags & INTEL_PT_ABORT_TX) {
1406                 decoder->tx_flags = 0;
1407                 decoder->state.flags &= ~INTEL_PT_IN_TX;
1408                 decoder->state.flags |= INTEL_PT_ABORT_TX;
1409         } else {
1410                 decoder->state.flags |= INTEL_PT_ASYNC;
1411         }
1412
1413         while (1) {
1414                 err = intel_pt_get_next_packet(decoder);
1415                 if (err)
1416                         return err;
1417
1418                 switch (decoder->packet.type) {
1419                 case INTEL_PT_TNT:
1420                 case INTEL_PT_FUP:
1421                 case INTEL_PT_TRACESTOP:
1422                 case INTEL_PT_PSB:
1423                 case INTEL_PT_TSC:
1424                 case INTEL_PT_TMA:
1425                 case INTEL_PT_CBR:
1426                 case INTEL_PT_MODE_TSX:
1427                 case INTEL_PT_BAD:
1428                 case INTEL_PT_PSBEND:
1429                         intel_pt_log("ERROR: Missing TIP after FUP\n");
1430                         decoder->pkt_state = INTEL_PT_STATE_ERR3;
1431                         return -ENOENT;
1432
1433                 case INTEL_PT_OVF:
1434                         return intel_pt_overflow(decoder);
1435
1436                 case INTEL_PT_TIP_PGD:
1437                         decoder->state.from_ip = decoder->ip;
1438                         decoder->state.to_ip = 0;
1439                         if (decoder->packet.count != 0) {
1440                                 intel_pt_set_ip(decoder);
1441                                 intel_pt_log("Omitting PGD ip " x64_fmt "\n",
1442                                              decoder->ip);
1443                         }
1444                         decoder->pge = false;
1445                         decoder->continuous_period = false;
1446                         return 0;
1447
1448                 case INTEL_PT_TIP_PGE:
1449                         decoder->pge = true;
1450                         intel_pt_log("Omitting PGE ip " x64_fmt "\n",
1451                                      decoder->ip);
1452                         decoder->state.from_ip = 0;
1453                         if (decoder->packet.count == 0) {
1454                                 decoder->state.to_ip = 0;
1455                         } else {
1456                                 intel_pt_set_ip(decoder);
1457                                 decoder->state.to_ip = decoder->ip;
1458                         }
1459                         return 0;
1460
1461                 case INTEL_PT_TIP:
1462                         decoder->state.from_ip = decoder->ip;
1463                         if (decoder->packet.count == 0) {
1464                                 decoder->state.to_ip = 0;
1465                         } else {
1466                                 intel_pt_set_ip(decoder);
1467                                 decoder->state.to_ip = decoder->ip;
1468                         }
1469                         return 0;
1470
1471                 case INTEL_PT_PIP:
1472                         decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1473                         break;
1474
1475                 case INTEL_PT_MTC:
1476                         intel_pt_calc_mtc_timestamp(decoder);
1477                         if (decoder->period_type == INTEL_PT_PERIOD_MTC)
1478                                 decoder->state.type |= INTEL_PT_INSTRUCTION;
1479                         break;
1480
1481                 case INTEL_PT_CYC:
1482                         intel_pt_calc_cyc_timestamp(decoder);
1483                         break;
1484
1485                 case INTEL_PT_MODE_EXEC:
1486                         decoder->exec_mode = decoder->packet.payload;
1487                         break;
1488
1489                 case INTEL_PT_VMCS:
1490                 case INTEL_PT_MNT:
1491                 case INTEL_PT_PAD:
1492                         break;
1493
1494                 default:
1495                         return intel_pt_bug(decoder);
1496                 }
1497         }
1498 }
1499
1500 static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
1501 {
1502         bool no_tip = false;
1503         int err;
1504
1505         while (1) {
1506                 err = intel_pt_get_next_packet(decoder);
1507                 if (err)
1508                         return err;
1509 next:
1510                 switch (decoder->packet.type) {
1511                 case INTEL_PT_TNT:
1512                         if (!decoder->packet.count)
1513                                 break;
1514                         decoder->tnt = decoder->packet;
1515                         decoder->pkt_state = INTEL_PT_STATE_TNT;
1516                         err = intel_pt_walk_tnt(decoder);
1517                         if (err == -EAGAIN)
1518                                 break;
1519                         return err;
1520
1521                 case INTEL_PT_TIP_PGD:
1522                         if (decoder->packet.count != 0)
1523                                 intel_pt_set_last_ip(decoder);
1524                         decoder->pkt_state = INTEL_PT_STATE_TIP_PGD;
1525                         return intel_pt_walk_tip(decoder);
1526
1527                 case INTEL_PT_TIP_PGE: {
1528                         decoder->pge = true;
1529                         if (decoder->packet.count == 0) {
1530                                 intel_pt_log_at("Skipping zero TIP.PGE",
1531                                                 decoder->pos);
1532                                 break;
1533                         }
1534                         intel_pt_set_ip(decoder);
1535                         decoder->state.from_ip = 0;
1536                         decoder->state.to_ip = decoder->ip;
1537                         return 0;
1538                 }
1539
1540                 case INTEL_PT_OVF:
1541                         return intel_pt_overflow(decoder);
1542
1543                 case INTEL_PT_TIP:
1544                         if (decoder->packet.count != 0)
1545                                 intel_pt_set_last_ip(decoder);
1546                         decoder->pkt_state = INTEL_PT_STATE_TIP;
1547                         return intel_pt_walk_tip(decoder);
1548
1549                 case INTEL_PT_FUP:
1550                         if (decoder->packet.count == 0) {
1551                                 intel_pt_log_at("Skipping zero FUP",
1552                                                 decoder->pos);
1553                                 no_tip = false;
1554                                 break;
1555                         }
1556                         intel_pt_set_last_ip(decoder);
1557                         err = intel_pt_walk_fup(decoder);
1558                         if (err != -EAGAIN) {
1559                                 if (err)
1560                                         return err;
1561                                 if (no_tip)
1562                                         decoder->pkt_state =
1563                                                 INTEL_PT_STATE_FUP_NO_TIP;
1564                                 else
1565                                         decoder->pkt_state = INTEL_PT_STATE_FUP;
1566                                 return 0;
1567                         }
1568                         if (no_tip) {
1569                                 no_tip = false;
1570                                 break;
1571                         }
1572                         return intel_pt_walk_fup_tip(decoder);
1573
1574                 case INTEL_PT_TRACESTOP:
1575                         decoder->pge = false;
1576                         decoder->continuous_period = false;
1577                         intel_pt_clear_tx_flags(decoder);
1578                         decoder->have_tma = false;
1579                         break;
1580
1581                 case INTEL_PT_PSB:
1582                         intel_pt_clear_stack(&decoder->stack);
1583                         err = intel_pt_walk_psbend(decoder);
1584                         if (err == -EAGAIN)
1585                                 goto next;
1586                         if (err)
1587                                 return err;
1588                         break;
1589
1590                 case INTEL_PT_PIP:
1591                         decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1592                         break;
1593
1594                 case INTEL_PT_MTC:
1595                         intel_pt_calc_mtc_timestamp(decoder);
1596                         if (decoder->period_type != INTEL_PT_PERIOD_MTC)
1597                                 break;
1598                         /*
1599                          * Ensure that there has been an instruction since the
1600                          * last MTC.
1601                          */
1602                         if (!decoder->mtc_insn)
1603                                 break;
1604                         decoder->mtc_insn = false;
1605                         /* Ensure that there is a timestamp */
1606                         if (!decoder->timestamp)
1607                                 break;
1608                         decoder->state.type = INTEL_PT_INSTRUCTION;
1609                         decoder->state.from_ip = decoder->ip;
1610                         decoder->state.to_ip = 0;
1611                         decoder->mtc_insn = false;
1612                         return 0;
1613
1614                 case INTEL_PT_TSC:
1615                         intel_pt_calc_tsc_timestamp(decoder);
1616                         break;
1617
1618                 case INTEL_PT_TMA:
1619                         intel_pt_calc_tma(decoder);
1620                         break;
1621
1622                 case INTEL_PT_CYC:
1623                         intel_pt_calc_cyc_timestamp(decoder);
1624                         break;
1625
1626                 case INTEL_PT_CBR:
1627                         intel_pt_calc_cbr(decoder);
1628                         break;
1629
1630                 case INTEL_PT_MODE_EXEC:
1631                         decoder->exec_mode = decoder->packet.payload;
1632                         break;
1633
1634                 case INTEL_PT_MODE_TSX:
1635                         /* MODE_TSX need not be followed by FUP */
1636                         if (!decoder->pge) {
1637                                 intel_pt_update_in_tx(decoder);
1638                                 break;
1639                         }
1640                         err = intel_pt_mode_tsx(decoder, &no_tip);
1641                         if (err)
1642                                 return err;
1643                         goto next;
1644
1645                 case INTEL_PT_BAD: /* Does not happen */
1646                         return intel_pt_bug(decoder);
1647
1648                 case INTEL_PT_PSBEND:
1649                 case INTEL_PT_VMCS:
1650                 case INTEL_PT_MNT:
1651                 case INTEL_PT_PAD:
1652                         break;
1653
1654                 default:
1655                         return intel_pt_bug(decoder);
1656                 }
1657         }
1658 }
1659
1660 static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder)
1661 {
1662         return decoder->last_ip || decoder->packet.count == 0 ||
1663                decoder->packet.count == 3 || decoder->packet.count == 6;
1664 }
1665
1666 /* Walk PSB+ packets to get in sync. */
1667 static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
1668 {
1669         int err;
1670
1671         while (1) {
1672                 err = intel_pt_get_next_packet(decoder);
1673                 if (err)
1674                         return err;
1675
1676                 switch (decoder->packet.type) {
1677                 case INTEL_PT_TIP_PGD:
1678                         decoder->continuous_period = false;
1679                 case INTEL_PT_TIP_PGE:
1680                 case INTEL_PT_TIP:
1681                         intel_pt_log("ERROR: Unexpected packet\n");
1682                         return -ENOENT;
1683
1684                 case INTEL_PT_FUP:
1685                         decoder->pge = true;
1686                         if (intel_pt_have_ip(decoder)) {
1687                                 uint64_t current_ip = decoder->ip;
1688
1689                                 intel_pt_set_ip(decoder);
1690                                 if (current_ip)
1691                                         intel_pt_log_to("Setting IP",
1692                                                         decoder->ip);
1693                         }
1694                         break;
1695
1696                 case INTEL_PT_MTC:
1697                         intel_pt_calc_mtc_timestamp(decoder);
1698                         break;
1699
1700                 case INTEL_PT_TSC:
1701                         intel_pt_calc_tsc_timestamp(decoder);
1702                         break;
1703
1704                 case INTEL_PT_TMA:
1705                         intel_pt_calc_tma(decoder);
1706                         break;
1707
1708                 case INTEL_PT_CYC:
1709                         intel_pt_calc_cyc_timestamp(decoder);
1710                         break;
1711
1712                 case INTEL_PT_CBR:
1713                         intel_pt_calc_cbr(decoder);
1714                         break;
1715
1716                 case INTEL_PT_PIP:
1717                         decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1718                         break;
1719
1720                 case INTEL_PT_MODE_EXEC:
1721                         decoder->exec_mode = decoder->packet.payload;
1722                         break;
1723
1724                 case INTEL_PT_MODE_TSX:
1725                         intel_pt_update_in_tx(decoder);
1726                         break;
1727
1728                 case INTEL_PT_TRACESTOP:
1729                         decoder->pge = false;
1730                         decoder->continuous_period = false;
1731                         intel_pt_clear_tx_flags(decoder);
1732                 case INTEL_PT_TNT:
1733                         decoder->have_tma = false;
1734                         intel_pt_log("ERROR: Unexpected packet\n");
1735                         if (decoder->ip)
1736                                 decoder->pkt_state = INTEL_PT_STATE_ERR4;
1737                         else
1738                                 decoder->pkt_state = INTEL_PT_STATE_ERR3;
1739                         return -ENOENT;
1740
1741                 case INTEL_PT_BAD: /* Does not happen */
1742                         return intel_pt_bug(decoder);
1743
1744                 case INTEL_PT_OVF:
1745                         return intel_pt_overflow(decoder);
1746
1747                 case INTEL_PT_PSBEND:
1748                         return 0;
1749
1750                 case INTEL_PT_PSB:
1751                 case INTEL_PT_VMCS:
1752                 case INTEL_PT_MNT:
1753                 case INTEL_PT_PAD:
1754                 default:
1755                         break;
1756                 }
1757         }
1758 }
1759
1760 static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
1761 {
1762         int err;
1763
1764         while (1) {
1765                 err = intel_pt_get_next_packet(decoder);
1766                 if (err)
1767                         return err;
1768
1769                 switch (decoder->packet.type) {
1770                 case INTEL_PT_TIP_PGD:
1771                         decoder->continuous_period = false;
1772                 case INTEL_PT_TIP_PGE:
1773                 case INTEL_PT_TIP:
1774                         decoder->pge = decoder->packet.type != INTEL_PT_TIP_PGD;
1775                         if (intel_pt_have_ip(decoder))
1776                                 intel_pt_set_ip(decoder);
1777                         if (decoder->ip)
1778                                 return 0;
1779                         break;
1780
1781                 case INTEL_PT_FUP:
1782                         if (decoder->overflow) {
1783                                 if (intel_pt_have_ip(decoder))
1784                                         intel_pt_set_ip(decoder);
1785                                 if (decoder->ip)
1786                                         return 0;
1787                         }
1788                         if (decoder->packet.count)
1789                                 intel_pt_set_last_ip(decoder);
1790                         break;
1791
1792                 case INTEL_PT_MTC:
1793                         intel_pt_calc_mtc_timestamp(decoder);
1794                         break;
1795
1796                 case INTEL_PT_TSC:
1797                         intel_pt_calc_tsc_timestamp(decoder);
1798                         break;
1799
1800                 case INTEL_PT_TMA:
1801                         intel_pt_calc_tma(decoder);
1802                         break;
1803
1804                 case INTEL_PT_CYC:
1805                         intel_pt_calc_cyc_timestamp(decoder);
1806                         break;
1807
1808                 case INTEL_PT_CBR:
1809                         intel_pt_calc_cbr(decoder);
1810                         break;
1811
1812                 case INTEL_PT_PIP:
1813                         decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1814                         break;
1815
1816                 case INTEL_PT_MODE_EXEC:
1817                         decoder->exec_mode = decoder->packet.payload;
1818                         break;
1819
1820                 case INTEL_PT_MODE_TSX:
1821                         intel_pt_update_in_tx(decoder);
1822                         break;
1823
1824                 case INTEL_PT_OVF:
1825                         return intel_pt_overflow(decoder);
1826
1827                 case INTEL_PT_BAD: /* Does not happen */
1828                         return intel_pt_bug(decoder);
1829
1830                 case INTEL_PT_TRACESTOP:
1831                         decoder->pge = false;
1832                         decoder->continuous_period = false;
1833                         intel_pt_clear_tx_flags(decoder);
1834                         decoder->have_tma = false;
1835                         break;
1836
1837                 case INTEL_PT_PSB:
1838                         err = intel_pt_walk_psb(decoder);
1839                         if (err)
1840                                 return err;
1841                         if (decoder->ip) {
1842                                 /* Do not have a sample */
1843                                 decoder->state.type = 0;
1844                                 return 0;
1845                         }
1846                         break;
1847
1848                 case INTEL_PT_TNT:
1849                 case INTEL_PT_PSBEND:
1850                 case INTEL_PT_VMCS:
1851                 case INTEL_PT_MNT:
1852                 case INTEL_PT_PAD:
1853                 default:
1854                         break;
1855                 }
1856         }
1857 }
1858
1859 static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
1860 {
1861         int err;
1862
1863         intel_pt_log("Scanning for full IP\n");
1864         err = intel_pt_walk_to_ip(decoder);
1865         if (err)
1866                 return err;
1867
1868         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1869         decoder->overflow = false;
1870
1871         decoder->state.from_ip = 0;
1872         decoder->state.to_ip = decoder->ip;
1873         intel_pt_log_to("Setting IP", decoder->ip);
1874
1875         return 0;
1876 }
1877
1878 static int intel_pt_part_psb(struct intel_pt_decoder *decoder)
1879 {
1880         const unsigned char *end = decoder->buf + decoder->len;
1881         size_t i;
1882
1883         for (i = INTEL_PT_PSB_LEN - 1; i; i--) {
1884                 if (i > decoder->len)
1885                         continue;
1886                 if (!memcmp(end - i, INTEL_PT_PSB_STR, i))
1887                         return i;
1888         }
1889         return 0;
1890 }
1891
1892 static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb)
1893 {
1894         size_t rest_psb = INTEL_PT_PSB_LEN - part_psb;
1895         const char *psb = INTEL_PT_PSB_STR;
1896
1897         if (rest_psb > decoder->len ||
1898             memcmp(decoder->buf, psb + part_psb, rest_psb))
1899                 return 0;
1900
1901         return rest_psb;
1902 }
1903
1904 static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder,
1905                                   int part_psb)
1906 {
1907         int rest_psb, ret;
1908
1909         decoder->pos += decoder->len;
1910         decoder->len = 0;
1911
1912         ret = intel_pt_get_next_data(decoder);
1913         if (ret)
1914                 return ret;
1915
1916         rest_psb = intel_pt_rest_psb(decoder, part_psb);
1917         if (!rest_psb)
1918                 return 0;
1919
1920         decoder->pos -= part_psb;
1921         decoder->next_buf = decoder->buf + rest_psb;
1922         decoder->next_len = decoder->len - rest_psb;
1923         memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
1924         decoder->buf = decoder->temp_buf;
1925         decoder->len = INTEL_PT_PSB_LEN;
1926
1927         return 0;
1928 }
1929
1930 static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder)
1931 {
1932         unsigned char *next;
1933         int ret;
1934
1935         intel_pt_log("Scanning for PSB\n");
1936         while (1) {
1937                 if (!decoder->len) {
1938                         ret = intel_pt_get_next_data(decoder);
1939                         if (ret)
1940                                 return ret;
1941                 }
1942
1943                 next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR,
1944                               INTEL_PT_PSB_LEN);
1945                 if (!next) {
1946                         int part_psb;
1947
1948                         part_psb = intel_pt_part_psb(decoder);
1949                         if (part_psb) {
1950                                 ret = intel_pt_get_split_psb(decoder, part_psb);
1951                                 if (ret)
1952                                         return ret;
1953                         } else {
1954                                 decoder->pos += decoder->len;
1955                                 decoder->len = 0;
1956                         }
1957                         continue;
1958                 }
1959
1960                 decoder->pkt_step = next - decoder->buf;
1961                 return intel_pt_get_next_packet(decoder);
1962         }
1963 }
1964
1965 static int intel_pt_sync(struct intel_pt_decoder *decoder)
1966 {
1967         int err;
1968
1969         decoder->pge = false;
1970         decoder->continuous_period = false;
1971         decoder->last_ip = 0;
1972         decoder->ip = 0;
1973         intel_pt_clear_stack(&decoder->stack);
1974
1975         err = intel_pt_scan_for_psb(decoder);
1976         if (err)
1977                 return err;
1978
1979         decoder->pkt_state = INTEL_PT_STATE_NO_IP;
1980
1981         err = intel_pt_walk_psb(decoder);
1982         if (err)
1983                 return err;
1984
1985         if (decoder->ip) {
1986                 decoder->state.type = 0; /* Do not have a sample */
1987                 decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1988         } else {
1989                 return intel_pt_sync_ip(decoder);
1990         }
1991
1992         return 0;
1993 }
1994
1995 static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
1996 {
1997         uint64_t est = decoder->timestamp_insn_cnt << 1;
1998
1999         if (!decoder->cbr || !decoder->max_non_turbo_ratio)
2000                 goto out;
2001
2002         est *= decoder->max_non_turbo_ratio;
2003         est /= decoder->cbr;
2004 out:
2005         return decoder->timestamp + est;
2006 }
2007
2008 const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
2009 {
2010         int err;
2011
2012         do {
2013                 decoder->state.type = INTEL_PT_BRANCH;
2014                 decoder->state.flags = 0;
2015
2016                 switch (decoder->pkt_state) {
2017                 case INTEL_PT_STATE_NO_PSB:
2018                         err = intel_pt_sync(decoder);
2019                         break;
2020                 case INTEL_PT_STATE_NO_IP:
2021                         decoder->last_ip = 0;
2022                         /* Fall through */
2023                 case INTEL_PT_STATE_ERR_RESYNC:
2024                         err = intel_pt_sync_ip(decoder);
2025                         break;
2026                 case INTEL_PT_STATE_IN_SYNC:
2027                         err = intel_pt_walk_trace(decoder);
2028                         break;
2029                 case INTEL_PT_STATE_TNT:
2030                         err = intel_pt_walk_tnt(decoder);
2031                         if (err == -EAGAIN)
2032                                 err = intel_pt_walk_trace(decoder);
2033                         break;
2034                 case INTEL_PT_STATE_TIP:
2035                 case INTEL_PT_STATE_TIP_PGD:
2036                         err = intel_pt_walk_tip(decoder);
2037                         break;
2038                 case INTEL_PT_STATE_FUP:
2039                         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2040                         err = intel_pt_walk_fup(decoder);
2041                         if (err == -EAGAIN)
2042                                 err = intel_pt_walk_fup_tip(decoder);
2043                         else if (!err)
2044                                 decoder->pkt_state = INTEL_PT_STATE_FUP;
2045                         break;
2046                 case INTEL_PT_STATE_FUP_NO_TIP:
2047                         decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2048                         err = intel_pt_walk_fup(decoder);
2049                         if (err == -EAGAIN)
2050                                 err = intel_pt_walk_trace(decoder);
2051                         break;
2052                 default:
2053                         err = intel_pt_bug(decoder);
2054                         break;
2055                 }
2056         } while (err == -ENOLINK);
2057
2058         decoder->state.err = err ? intel_pt_ext_err(err) : 0;
2059         decoder->state.timestamp = decoder->timestamp;
2060         decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
2061         decoder->state.cr3 = decoder->cr3;
2062         decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
2063
2064         if (err)
2065                 decoder->state.from_ip = decoder->ip;
2066
2067         return &decoder->state;
2068 }
2069
2070 static bool intel_pt_at_psb(unsigned char *buf, size_t len)
2071 {
2072         if (len < INTEL_PT_PSB_LEN)
2073                 return false;
2074         return memmem(buf, INTEL_PT_PSB_LEN, INTEL_PT_PSB_STR,
2075                       INTEL_PT_PSB_LEN);
2076 }
2077
2078 /**
2079  * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet.
2080  * @buf: pointer to buffer pointer
2081  * @len: size of buffer
2082  *
2083  * Updates the buffer pointer to point to the start of the next PSB packet if
2084  * there is one, otherwise the buffer pointer is unchanged.  If @buf is updated,
2085  * @len is adjusted accordingly.
2086  *
2087  * Return: %true if a PSB packet is found, %false otherwise.
2088  */
2089 static bool intel_pt_next_psb(unsigned char **buf, size_t *len)
2090 {
2091         unsigned char *next;
2092
2093         next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
2094         if (next) {
2095                 *len -= next - *buf;
2096                 *buf = next;
2097                 return true;
2098         }
2099         return false;
2100 }
2101
2102 /**
2103  * intel_pt_step_psb - move buffer pointer to the start of the following PSB
2104  *                     packet.
2105  * @buf: pointer to buffer pointer
2106  * @len: size of buffer
2107  *
2108  * Updates the buffer pointer to point to the start of the following PSB packet
2109  * (skipping the PSB at @buf itself) if there is one, otherwise the buffer
2110  * pointer is unchanged.  If @buf is updated, @len is adjusted accordingly.
2111  *
2112  * Return: %true if a PSB packet is found, %false otherwise.
2113  */
2114 static bool intel_pt_step_psb(unsigned char **buf, size_t *len)
2115 {
2116         unsigned char *next;
2117
2118         if (!*len)
2119                 return false;
2120
2121         next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
2122         if (next) {
2123                 *len -= next - *buf;
2124                 *buf = next;
2125                 return true;
2126         }
2127         return false;
2128 }
2129
2130 /**
2131  * intel_pt_last_psb - find the last PSB packet in a buffer.
2132  * @buf: buffer
2133  * @len: size of buffer
2134  *
2135  * This function finds the last PSB in a buffer.
2136  *
2137  * Return: A pointer to the last PSB in @buf if found, %NULL otherwise.
2138  */
2139 static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
2140 {
2141         const char *n = INTEL_PT_PSB_STR;
2142         unsigned char *p;
2143         size_t k;
2144
2145         if (len < INTEL_PT_PSB_LEN)
2146                 return NULL;
2147
2148         k = len - INTEL_PT_PSB_LEN + 1;
2149         while (1) {
2150                 p = memrchr(buf, n[0], k);
2151                 if (!p)
2152                         return NULL;
2153                 if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1))
2154                         return p;
2155                 k = p - buf;
2156                 if (!k)
2157                         return NULL;
2158         }
2159 }
2160
2161 /**
2162  * intel_pt_next_tsc - find and return next TSC.
2163  * @buf: buffer
2164  * @len: size of buffer
2165  * @tsc: TSC value returned
2166  *
2167  * Find a TSC packet in @buf and return the TSC value.  This function assumes
2168  * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a
2169  * PSBEND packet is found.
2170  *
2171  * Return: %true if TSC is found, false otherwise.
2172  */
2173 static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc)
2174 {
2175         struct intel_pt_pkt packet;
2176         int ret;
2177
2178         while (len) {
2179                 ret = intel_pt_get_packet(buf, len, &packet);
2180                 if (ret <= 0)
2181                         return false;
2182                 if (packet.type == INTEL_PT_TSC) {
2183                         *tsc = packet.payload;
2184                         return true;
2185                 }
2186                 if (packet.type == INTEL_PT_PSBEND)
2187                         return false;
2188                 buf += ret;
2189                 len -= ret;
2190         }
2191         return false;
2192 }
2193
2194 /**
2195  * intel_pt_tsc_cmp - compare 7-byte TSCs.
2196  * @tsc1: first TSC to compare
2197  * @tsc2: second TSC to compare
2198  *
2199  * This function compares 7-byte TSC values allowing for the possibility that
2200  * TSC wrapped around.  Generally it is not possible to know if TSC has wrapped
2201  * around so for that purpose this function assumes the absolute difference is
2202  * less than half the maximum difference.
2203  *
2204  * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is
2205  * after @tsc2.
2206  */
2207 static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2)
2208 {
2209         const uint64_t halfway = (1ULL << 55);
2210
2211         if (tsc1 == tsc2)
2212                 return 0;
2213
2214         if (tsc1 < tsc2) {
2215                 if (tsc2 - tsc1 < halfway)
2216                         return -1;
2217                 else
2218                         return 1;
2219         } else {
2220                 if (tsc1 - tsc2 < halfway)
2221                         return 1;
2222                 else
2223                         return -1;
2224         }
2225 }
2226
2227 /**
2228  * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data
2229  *                             using TSC.
2230  * @buf_a: first buffer
2231  * @len_a: size of first buffer
2232  * @buf_b: second buffer
2233  * @len_b: size of second buffer
2234  *
2235  * If the trace contains TSC we can look at the last TSC of @buf_a and the
2236  * first TSC of @buf_b in order to determine if the buffers overlap, and then
2237  * walk forward in @buf_b until a later TSC is found.  A precondition is that
2238  * @buf_a and @buf_b are positioned at a PSB.
2239  *
2240  * Return: A pointer into @buf_b from where non-overlapped data starts, or
2241  * @buf_b + @len_b if there is no non-overlapped data.
2242  */
2243 static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,
2244                                                 size_t len_a,
2245                                                 unsigned char *buf_b,
2246                                                 size_t len_b)
2247 {
2248         uint64_t tsc_a, tsc_b;
2249         unsigned char *p;
2250         size_t len;
2251
2252         p = intel_pt_last_psb(buf_a, len_a);
2253         if (!p)
2254                 return buf_b; /* No PSB in buf_a => no overlap */
2255
2256         len = len_a - (p - buf_a);
2257         if (!intel_pt_next_tsc(p, len, &tsc_a)) {
2258                 /* The last PSB+ in buf_a is incomplete, so go back one more */
2259                 len_a -= len;
2260                 p = intel_pt_last_psb(buf_a, len_a);
2261                 if (!p)
2262                         return buf_b; /* No full PSB+ => assume no overlap */
2263                 len = len_a - (p - buf_a);
2264                 if (!intel_pt_next_tsc(p, len, &tsc_a))
2265                         return buf_b; /* No TSC in buf_a => assume no overlap */
2266         }
2267
2268         while (1) {
2269                 /* Ignore PSB+ with no TSC */
2270                 if (intel_pt_next_tsc(buf_b, len_b, &tsc_b) &&
2271                     intel_pt_tsc_cmp(tsc_a, tsc_b) < 0)
2272                         return buf_b; /* tsc_a < tsc_b => no overlap */
2273
2274                 if (!intel_pt_step_psb(&buf_b, &len_b))
2275                         return buf_b + len_b; /* No PSB in buf_b => no data */
2276         }
2277 }
2278
2279 /**
2280  * intel_pt_find_overlap - determine start of non-overlapped trace data.
2281  * @buf_a: first buffer
2282  * @len_a: size of first buffer
2283  * @buf_b: second buffer
2284  * @len_b: size of second buffer
2285  * @have_tsc: can use TSC packets to detect overlap
2286  *
2287  * When trace samples or snapshots are recorded there is the possibility that
2288  * the data overlaps.  Note that, for the purposes of decoding, data is only
2289  * useful if it begins with a PSB packet.
2290  *
2291  * Return: A pointer into @buf_b from where non-overlapped data starts, or
2292  * @buf_b + @len_b if there is no non-overlapped data.
2293  */
2294 unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a,
2295                                      unsigned char *buf_b, size_t len_b,
2296                                      bool have_tsc)
2297 {
2298         unsigned char *found;
2299
2300         /* Buffer 'b' must start at PSB so throw away everything before that */
2301         if (!intel_pt_next_psb(&buf_b, &len_b))
2302                 return buf_b + len_b; /* No PSB */
2303
2304         if (!intel_pt_next_psb(&buf_a, &len_a))
2305                 return buf_b; /* No overlap */
2306
2307         if (have_tsc) {
2308                 found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b);
2309                 if (found)
2310                         return found;
2311         }
2312
2313         /*
2314          * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes,
2315          * we can ignore the first part of buffer 'a'.
2316          */
2317         while (len_b < len_a) {
2318                 if (!intel_pt_step_psb(&buf_a, &len_a))
2319                         return buf_b; /* No overlap */
2320         }
2321
2322         /* Now len_b >= len_a */
2323         if (len_b > len_a) {
2324                 /* The leftover buffer 'b' must start at a PSB */
2325                 while (!intel_pt_at_psb(buf_b + len_a, len_b - len_a)) {
2326                         if (!intel_pt_step_psb(&buf_a, &len_a))
2327                                 return buf_b; /* No overlap */
2328                 }
2329         }
2330
2331         while (1) {
2332                 /* Potential overlap so check the bytes */
2333                 found = memmem(buf_a, len_a, buf_b, len_a);
2334                 if (found)
2335                         return buf_b + len_a;
2336
2337                 /* Try again at next PSB in buffer 'a' */
2338                 if (!intel_pt_step_psb(&buf_a, &len_a))
2339                         return buf_b; /* No overlap */
2340
2341                 /* The leftover buffer 'b' must start at a PSB */
2342                 while (!intel_pt_at_psb(buf_b + len_a, len_b - len_a)) {
2343                         if (!intel_pt_step_psb(&buf_a, &len_a))
2344                                 return buf_b; /* No overlap */
2345                 }
2346         }
2347 }