linux/tools/perf/util/intel-pt-decoder/intel-pt-decoder.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * intel_pt_decoder.c: Intel Processor Trace support
   4 * Copyright (c) 2013-2014, Intel Corporation.
   5 */
   6
   7#ifndef _GNU_SOURCE
   8#define _GNU_SOURCE
   9#endif
  10#include <stdlib.h>
  11#include <stdbool.h>
  12#include <string.h>
  13#include <errno.h>
  14#include <stdint.h>
  15#include <inttypes.h>
  16#include <linux/compiler.h>
  17#include <linux/string.h>
  18#include <linux/zalloc.h>
  19
  20#include "../auxtrace.h"
  21
  22#include "intel-pt-insn-decoder.h"
  23#include "intel-pt-pkt-decoder.h"
  24#include "intel-pt-decoder.h"
  25#include "intel-pt-log.h"
  26
  27#define INTEL_PT_BLK_SIZE 1024
  28
  29#define BIT63 (((uint64_t)1 << 63))
  30
  31#define INTEL_PT_RETURN 1
  32
  33/* Maximum number of loops with no packets consumed i.e. stuck in a loop */
  34#define INTEL_PT_MAX_LOOPS 10000
  35
  36struct intel_pt_blk {
  37        struct intel_pt_blk *prev;
  38        uint64_t ip[INTEL_PT_BLK_SIZE];
  39};
  40
  41struct intel_pt_stack {
  42        struct intel_pt_blk *blk;
  43        struct intel_pt_blk *spare;
  44        int pos;
  45};
  46
  47enum intel_pt_pkt_state {
  48        INTEL_PT_STATE_NO_PSB,
  49        INTEL_PT_STATE_NO_IP,
  50        INTEL_PT_STATE_ERR_RESYNC,
  51        INTEL_PT_STATE_IN_SYNC,
  52        INTEL_PT_STATE_TNT_CONT,
  53        INTEL_PT_STATE_TNT,
  54        INTEL_PT_STATE_TIP,
  55        INTEL_PT_STATE_TIP_PGD,
  56        INTEL_PT_STATE_FUP,
  57        INTEL_PT_STATE_FUP_NO_TIP,
  58        INTEL_PT_STATE_RESAMPLE,
  59};
  60
  61static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state)
  62{
  63        switch (pkt_state) {
  64        case INTEL_PT_STATE_NO_PSB:
  65        case INTEL_PT_STATE_NO_IP:
  66        case INTEL_PT_STATE_ERR_RESYNC:
  67        case INTEL_PT_STATE_IN_SYNC:
  68        case INTEL_PT_STATE_TNT_CONT:
  69        case INTEL_PT_STATE_RESAMPLE:
  70                return true;
  71        case INTEL_PT_STATE_TNT:
  72        case INTEL_PT_STATE_TIP:
  73        case INTEL_PT_STATE_TIP_PGD:
  74        case INTEL_PT_STATE_FUP:
  75        case INTEL_PT_STATE_FUP_NO_TIP:
  76                return false;
  77        default:
  78                return true;
  79        };
  80}
  81
  82#ifdef INTEL_PT_STRICT
  83#define INTEL_PT_STATE_ERR1     INTEL_PT_STATE_NO_PSB
  84#define INTEL_PT_STATE_ERR2     INTEL_PT_STATE_NO_PSB
  85#define INTEL_PT_STATE_ERR3     INTEL_PT_STATE_NO_PSB
  86#define INTEL_PT_STATE_ERR4     INTEL_PT_STATE_NO_PSB
  87#else
  88#define INTEL_PT_STATE_ERR1     (decoder->pkt_state)
  89#define INTEL_PT_STATE_ERR2     INTEL_PT_STATE_NO_IP
  90#define INTEL_PT_STATE_ERR3     INTEL_PT_STATE_ERR_RESYNC
  91#define INTEL_PT_STATE_ERR4     INTEL_PT_STATE_IN_SYNC
  92#endif
  93
  94struct intel_pt_decoder {
  95        int (*get_trace)(struct intel_pt_buffer *buffer, void *data);
  96        int (*walk_insn)(struct intel_pt_insn *intel_pt_insn,
  97                         uint64_t *insn_cnt_ptr, uint64_t *ip, uint64_t to_ip,
  98                         uint64_t max_insn_cnt, void *data);
  99        bool (*pgd_ip)(uint64_t ip, void *data);
 100        int (*lookahead)(void *data, intel_pt_lookahead_cb_t cb, void *cb_data);
 101        void *data;
 102        struct intel_pt_state state;
 103        const unsigned char *buf;
 104        size_t len;
 105        bool return_compression;
 106        bool branch_enable;
 107        bool mtc_insn;
 108        bool pge;
 109        bool have_tma;
 110        bool have_cyc;
 111        bool fixup_last_mtc;
 112        bool have_last_ip;
 113        bool in_psb;
 114        bool hop;
 115        bool hop_psb_fup;
 116        bool leap;
 117        enum intel_pt_param_flags flags;
 118        uint64_t pos;
 119        uint64_t last_ip;
 120        uint64_t ip;
 121        uint64_t cr3;
 122        uint64_t timestamp;
 123        uint64_t tsc_timestamp;
 124        uint64_t ref_timestamp;
 125        uint64_t buf_timestamp;
 126        uint64_t sample_timestamp;
 127        uint64_t ret_addr;
 128        uint64_t ctc_timestamp;
 129        uint64_t ctc_delta;
 130        uint64_t cycle_cnt;
 131        uint64_t cyc_ref_timestamp;
 132        uint32_t last_mtc;
 133        uint32_t tsc_ctc_ratio_n;
 134        uint32_t tsc_ctc_ratio_d;
 135        uint32_t tsc_ctc_mult;
 136        uint32_t tsc_slip;
 137        uint32_t ctc_rem_mask;
 138        int mtc_shift;
 139        struct intel_pt_stack stack;
 140        enum intel_pt_pkt_state pkt_state;
 141        enum intel_pt_pkt_ctx pkt_ctx;
 142        enum intel_pt_pkt_ctx prev_pkt_ctx;
 143        enum intel_pt_blk_type blk_type;
 144        int blk_type_pos;
 145        struct intel_pt_pkt packet;
 146        struct intel_pt_pkt tnt;
 147        int pkt_step;
 148        int pkt_len;
 149        int last_packet_type;
 150        unsigned int cbr;
 151        unsigned int cbr_seen;
 152        unsigned int max_non_turbo_ratio;
 153        double max_non_turbo_ratio_fp;
 154        double cbr_cyc_to_tsc;
 155        double calc_cyc_to_tsc;
 156        bool have_calc_cyc_to_tsc;
 157        int exec_mode;
 158        unsigned int insn_bytes;
 159        uint64_t period;
 160        enum intel_pt_period_type period_type;
 161        uint64_t tot_insn_cnt;
 162        uint64_t period_insn_cnt;
 163        uint64_t period_mask;
 164        uint64_t period_ticks;
 165        uint64_t last_masked_timestamp;
 166        uint64_t tot_cyc_cnt;
 167        uint64_t sample_tot_cyc_cnt;
 168        uint64_t base_cyc_cnt;
 169        uint64_t cyc_cnt_timestamp;
 170        double tsc_to_cyc;
 171        bool continuous_period;
 172        bool overflow;
 173        bool set_fup_tx_flags;
 174        bool set_fup_ptw;
 175        bool set_fup_mwait;
 176        bool set_fup_pwre;
 177        bool set_fup_exstop;
 178        bool set_fup_bep;
 179        bool sample_cyc;
 180        unsigned int fup_tx_flags;
 181        unsigned int tx_flags;
 182        uint64_t fup_ptw_payload;
 183        uint64_t fup_mwait_payload;
 184        uint64_t fup_pwre_payload;
 185        uint64_t cbr_payload;
 186        uint64_t timestamp_insn_cnt;
 187        uint64_t sample_insn_cnt;
 188        uint64_t stuck_ip;
 189        int no_progress;
 190        int stuck_ip_prd;
 191        int stuck_ip_cnt;
 192        const unsigned char *next_buf;
 193        size_t next_len;
 194        unsigned char temp_buf[INTEL_PT_PKT_MAX_SZ];
 195};
 196
 197static uint64_t intel_pt_lower_power_of_2(uint64_t x)
 198{
 199        int i;
 200
 201        for (i = 0; x != 1; i++)
 202                x >>= 1;
 203
 204        return x << i;
 205}
 206
 207static void intel_pt_setup_period(struct intel_pt_decoder *decoder)
 208{
 209        if (decoder->period_type == INTEL_PT_PERIOD_TICKS) {
 210                uint64_t period;
 211
 212                period = intel_pt_lower_power_of_2(decoder->period);
 213                decoder->period_mask  = ~(period - 1);
 214                decoder->period_ticks = period;
 215        }
 216}
 217
 218static uint64_t multdiv(uint64_t t, uint32_t n, uint32_t d)
 219{
 220        if (!d)
 221                return 0;
 222        return (t / d) * n + ((t % d) * n) / d;
 223}
 224
 225struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params)
 226{
 227        struct intel_pt_decoder *decoder;
 228
 229        if (!params->get_trace || !params->walk_insn)
 230                return NULL;
 231
 232        decoder = zalloc(sizeof(struct intel_pt_decoder));
 233        if (!decoder)
 234                return NULL;
 235
 236        decoder->get_trace          = params->get_trace;
 237        decoder->walk_insn          = params->walk_insn;
 238        decoder->pgd_ip             = params->pgd_ip;
 239        decoder->lookahead          = params->lookahead;
 240        decoder->data               = params->data;
 241        decoder->return_compression = params->return_compression;
 242        decoder->branch_enable      = params->branch_enable;
 243        decoder->hop                = params->quick >= 1;
 244        decoder->leap               = params->quick >= 2;
 245
 246        decoder->flags              = params->flags;
 247
 248        decoder->period             = params->period;
 249        decoder->period_type        = params->period_type;
 250
 251        decoder->max_non_turbo_ratio    = params->max_non_turbo_ratio;
 252        decoder->max_non_turbo_ratio_fp = params->max_non_turbo_ratio;
 253
 254        intel_pt_setup_period(decoder);
 255
 256        decoder->mtc_shift = params->mtc_period;
 257        decoder->ctc_rem_mask = (1 << decoder->mtc_shift) - 1;
 258
 259        decoder->tsc_ctc_ratio_n = params->tsc_ctc_ratio_n;
 260        decoder->tsc_ctc_ratio_d = params->tsc_ctc_ratio_d;
 261
 262        if (!decoder->tsc_ctc_ratio_n)
 263                decoder->tsc_ctc_ratio_d = 0;
 264
 265        if (decoder->tsc_ctc_ratio_d) {
 266                if (!(decoder->tsc_ctc_ratio_n % decoder->tsc_ctc_ratio_d))
 267                        decoder->tsc_ctc_mult = decoder->tsc_ctc_ratio_n /
 268                                                decoder->tsc_ctc_ratio_d;
 269        }
 270
 271        /*
 272         * A TSC packet can slip past MTC packets so that the timestamp appears
 273         * to go backwards. One estimate is that can be up to about 40 CPU
 274         * cycles, which is certainly less than 0x1000 TSC ticks, but accept
 275         * slippage an order of magnitude more to be on the safe side.
 276         */
 277        decoder->tsc_slip = 0x10000;
 278
 279        intel_pt_log("timestamp: mtc_shift %u\n", decoder->mtc_shift);
 280        intel_pt_log("timestamp: tsc_ctc_ratio_n %u\n", decoder->tsc_ctc_ratio_n);
 281        intel_pt_log("timestamp: tsc_ctc_ratio_d %u\n", decoder->tsc_ctc_ratio_d);
 282        intel_pt_log("timestamp: tsc_ctc_mult %u\n", decoder->tsc_ctc_mult);
 283        intel_pt_log("timestamp: tsc_slip %#x\n", decoder->tsc_slip);
 284
 285        if (decoder->hop)
 286                intel_pt_log("Hop mode: decoding FUP and TIPs, but not TNT\n");
 287
 288        return decoder;
 289}
 290
 291static void intel_pt_pop_blk(struct intel_pt_stack *stack)
 292{
 293        struct intel_pt_blk *blk = stack->blk;
 294
 295        stack->blk = blk->prev;
 296        if (!stack->spare)
 297                stack->spare = blk;
 298        else
 299                free(blk);
 300}
 301
 302static uint64_t intel_pt_pop(struct intel_pt_stack *stack)
 303{
 304        if (!stack->pos) {
 305                if (!stack->blk)
 306                        return 0;
 307                intel_pt_pop_blk(stack);
 308                if (!stack->blk)
 309                        return 0;
 310                stack->pos = INTEL_PT_BLK_SIZE;
 311        }
 312        return stack->blk->ip[--stack->pos];
 313}
 314
 315static int intel_pt_alloc_blk(struct intel_pt_stack *stack)
 316{
 317        struct intel_pt_blk *blk;
 318
 319        if (stack->spare) {
 320                blk = stack->spare;
 321                stack->spare = NULL;
 322        } else {
 323                blk = malloc(sizeof(struct intel_pt_blk));
 324                if (!blk)
 325                        return -ENOMEM;
 326        }
 327
 328        blk->prev = stack->blk;
 329        stack->blk = blk;
 330        stack->pos = 0;
 331        return 0;
 332}
 333
 334static int intel_pt_push(struct intel_pt_stack *stack, uint64_t ip)
 335{
 336        int err;
 337
 338        if (!stack->blk || stack->pos == INTEL_PT_BLK_SIZE) {
 339                err = intel_pt_alloc_blk(stack);
 340                if (err)
 341                        return err;
 342        }
 343
 344        stack->blk->ip[stack->pos++] = ip;
 345        return 0;
 346}
 347
 348static void intel_pt_clear_stack(struct intel_pt_stack *stack)
 349{
 350        while (stack->blk)
 351                intel_pt_pop_blk(stack);
 352        stack->pos = 0;
 353}
 354
 355static void intel_pt_free_stack(struct intel_pt_stack *stack)
 356{
 357        intel_pt_clear_stack(stack);
 358        zfree(&stack->blk);
 359        zfree(&stack->spare);
 360}
 361
 362void intel_pt_decoder_free(struct intel_pt_decoder *decoder)
 363{
 364        intel_pt_free_stack(&decoder->stack);
 365        free(decoder);
 366}
 367
 368static int intel_pt_ext_err(int code)
 369{
 370        switch (code) {
 371        case -ENOMEM:
 372                return INTEL_PT_ERR_NOMEM;
 373        case -ENOSYS:
 374                return INTEL_PT_ERR_INTERN;
 375        case -EBADMSG:
 376                return INTEL_PT_ERR_BADPKT;
 377        case -ENODATA:
 378                return INTEL_PT_ERR_NODATA;
 379        case -EILSEQ:
 380                return INTEL_PT_ERR_NOINSN;
 381        case -ENOENT:
 382                return INTEL_PT_ERR_MISMAT;
 383        case -EOVERFLOW:
 384                return INTEL_PT_ERR_OVR;
 385        case -ENOSPC:
 386                return INTEL_PT_ERR_LOST;
 387        case -ELOOP:
 388                return INTEL_PT_ERR_NELOOP;
 389        default:
 390                return INTEL_PT_ERR_UNK;
 391        }
 392}
 393
 394static const char *intel_pt_err_msgs[] = {
 395        [INTEL_PT_ERR_NOMEM]  = "Memory allocation failed",
 396        [INTEL_PT_ERR_INTERN] = "Internal error",
 397        [INTEL_PT_ERR_BADPKT] = "Bad packet",
 398        [INTEL_PT_ERR_NODATA] = "No more data",
 399        [INTEL_PT_ERR_NOINSN] = "Failed to get instruction",
 400        [INTEL_PT_ERR_MISMAT] = "Trace doesn't match instruction",
 401        [INTEL_PT_ERR_OVR]    = "Overflow packet",
 402        [INTEL_PT_ERR_LOST]   = "Lost trace data",
 403        [INTEL_PT_ERR_UNK]    = "Unknown error!",
 404        [INTEL_PT_ERR_NELOOP] = "Never-ending loop",
 405};
 406
 407int intel_pt__strerror(int code, char *buf, size_t buflen)
 408{
 409        if (code < 1 || code >= INTEL_PT_ERR_MAX)
 410                code = INTEL_PT_ERR_UNK;
 411        strlcpy(buf, intel_pt_err_msgs[code], buflen);
 412        return 0;
 413}
 414
 415static uint64_t intel_pt_calc_ip(const struct intel_pt_pkt *packet,
 416                                 uint64_t last_ip)
 417{
 418        uint64_t ip;
 419
 420        switch (packet->count) {
 421        case 1:
 422                ip = (last_ip & (uint64_t)0xffffffffffff0000ULL) |
 423                     packet->payload;
 424                break;
 425        case 2:
 426                ip = (last_ip & (uint64_t)0xffffffff00000000ULL) |
 427                     packet->payload;
 428                break;
 429        case 3:
 430                ip = packet->payload;
 431                /* Sign-extend 6-byte ip */
 432                if (ip & (uint64_t)0x800000000000ULL)
 433                        ip |= (uint64_t)0xffff000000000000ULL;
 434                break;
 435        case 4:
 436                ip = (last_ip & (uint64_t)0xffff000000000000ULL) |
 437                     packet->payload;
 438                break;
 439        case 6:
 440                ip = packet->payload;
 441                break;
 442        default:
 443                return 0;
 444        }
 445
 446        return ip;
 447}
 448
 449static inline void intel_pt_set_last_ip(struct intel_pt_decoder *decoder)
 450{
 451        decoder->last_ip = intel_pt_calc_ip(&decoder->packet, decoder->last_ip);
 452        decoder->have_last_ip = true;
 453}
 454
 455static inline void intel_pt_set_ip(struct intel_pt_decoder *decoder)
 456{
 457        intel_pt_set_last_ip(decoder);
 458        decoder->ip = decoder->last_ip;
 459}
 460
 461static void intel_pt_decoder_log_packet(struct intel_pt_decoder *decoder)
 462{
 463        intel_pt_log_packet(&decoder->packet, decoder->pkt_len, decoder->pos,
 464                            decoder->buf);
 465}
 466
 467static int intel_pt_bug(struct intel_pt_decoder *decoder)
 468{
 469        intel_pt_log("ERROR: Internal error\n");
 470        decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
 471        return -ENOSYS;
 472}
 473
 474static inline void intel_pt_clear_tx_flags(struct intel_pt_decoder *decoder)
 475{
 476        decoder->tx_flags = 0;
 477}
 478
 479static inline void intel_pt_update_in_tx(struct intel_pt_decoder *decoder)
 480{
 481        decoder->tx_flags = decoder->packet.payload & INTEL_PT_IN_TX;
 482}
 483
 484static int intel_pt_bad_packet(struct intel_pt_decoder *decoder)
 485{
 486        intel_pt_clear_tx_flags(decoder);
 487        decoder->have_tma = false;
 488        decoder->pkt_len = 1;
 489        decoder->pkt_step = 1;
 490        intel_pt_decoder_log_packet(decoder);
 491        if (decoder->pkt_state != INTEL_PT_STATE_NO_PSB) {
 492                intel_pt_log("ERROR: Bad packet\n");
 493                decoder->pkt_state = INTEL_PT_STATE_ERR1;
 494        }
 495        return -EBADMSG;
 496}
 497
 498static inline void intel_pt_update_sample_time(struct intel_pt_decoder *decoder)
 499{
 500        decoder->sample_timestamp = decoder->timestamp;
 501        decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
 502}
 503
 504static void intel_pt_reposition(struct intel_pt_decoder *decoder)
 505{
 506        decoder->ip = 0;
 507        decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
 508        decoder->timestamp = 0;
 509        decoder->have_tma = false;
 510}
 511
 512static int intel_pt_get_data(struct intel_pt_decoder *decoder, bool reposition)
 513{
 514        struct intel_pt_buffer buffer = { .buf = 0, };
 515        int ret;
 516
 517        decoder->pkt_step = 0;
 518
 519        intel_pt_log("Getting more data\n");
 520        ret = decoder->get_trace(&buffer, decoder->data);
 521        if (ret)
 522                return ret;
 523        decoder->buf = buffer.buf;
 524        decoder->len = buffer.len;
 525        if (!decoder->len) {
 526                intel_pt_log("No more data\n");
 527                return -ENODATA;
 528        }
 529        decoder->buf_timestamp = buffer.ref_timestamp;
 530        if (!buffer.consecutive || reposition) {
 531                intel_pt_reposition(decoder);
 532                decoder->ref_timestamp = buffer.ref_timestamp;
 533                decoder->state.trace_nr = buffer.trace_nr;
 534                intel_pt_log("Reference timestamp 0x%" PRIx64 "\n",
 535                             decoder->ref_timestamp);
 536                return -ENOLINK;
 537        }
 538
 539        return 0;
 540}
 541
 542static int intel_pt_get_next_data(struct intel_pt_decoder *decoder,
 543                                  bool reposition)
 544{
 545        if (!decoder->next_buf)
 546                return intel_pt_get_data(decoder, reposition);
 547
 548        decoder->buf = decoder->next_buf;
 549        decoder->len = decoder->next_len;
 550        decoder->next_buf = 0;
 551        decoder->next_len = 0;
 552        return 0;
 553}
 554
 555static int intel_pt_get_split_packet(struct intel_pt_decoder *decoder)
 556{
 557        unsigned char *buf = decoder->temp_buf;
 558        size_t old_len, len, n;
 559        int ret;
 560
 561        old_len = decoder->len;
 562        len = decoder->len;
 563        memcpy(buf, decoder->buf, len);
 564
 565        ret = intel_pt_get_data(decoder, false);
 566        if (ret) {
 567                decoder->pos += old_len;
 568                return ret < 0 ? ret : -EINVAL;
 569        }
 570
 571        n = INTEL_PT_PKT_MAX_SZ - len;
 572        if (n > decoder->len)
 573                n = decoder->len;
 574        memcpy(buf + len, decoder->buf, n);
 575        len += n;
 576
 577        decoder->prev_pkt_ctx = decoder->pkt_ctx;
 578        ret = intel_pt_get_packet(buf, len, &decoder->packet, &decoder->pkt_ctx);
 579        if (ret < (int)old_len) {
 580                decoder->next_buf = decoder->buf;
 581                decoder->next_len = decoder->len;
 582                decoder->buf = buf;
 583                decoder->len = old_len;
 584                return intel_pt_bad_packet(decoder);
 585        }
 586
 587        decoder->next_buf = decoder->buf + (ret - old_len);
 588        decoder->next_len = decoder->len - (ret - old_len);
 589
 590        decoder->buf = buf;
 591        decoder->len = ret;
 592
 593        return ret;
 594}
 595
 596struct intel_pt_pkt_info {
 597        struct intel_pt_decoder   *decoder;
 598        struct intel_pt_pkt       packet;
 599        uint64_t                  pos;
 600        int                       pkt_len;
 601        int                       last_packet_type;
 602        void                      *data;
 603};
 604
 605typedef int (*intel_pt_pkt_cb_t)(struct intel_pt_pkt_info *pkt_info);
 606
 607/* Lookahead packets in current buffer */
 608static int intel_pt_pkt_lookahead(struct intel_pt_decoder *decoder,
 609                                  intel_pt_pkt_cb_t cb, void *data)
 610{
 611        struct intel_pt_pkt_info pkt_info;
 612        const unsigned char *buf = decoder->buf;
 613        enum intel_pt_pkt_ctx pkt_ctx = decoder->pkt_ctx;
 614        size_t len = decoder->len;
 615        int ret;
 616
 617        pkt_info.decoder          = decoder;
 618        pkt_info.pos              = decoder->pos;
 619        pkt_info.pkt_len          = decoder->pkt_step;
 620        pkt_info.last_packet_type = decoder->last_packet_type;
 621        pkt_info.data             = data;
 622
 623        while (1) {
 624                do {
 625                        pkt_info.pos += pkt_info.pkt_len;
 626                        buf          += pkt_info.pkt_len;
 627                        len          -= pkt_info.pkt_len;
 628
 629                        if (!len)
 630                                return INTEL_PT_NEED_MORE_BYTES;
 631
 632                        ret = intel_pt_get_packet(buf, len, &pkt_info.packet,
 633                                                  &pkt_ctx);
 634                        if (!ret)
 635                                return INTEL_PT_NEED_MORE_BYTES;
 636                        if (ret < 0)
 637                                return ret;
 638
 639                        pkt_info.pkt_len = ret;
 640                } while (pkt_info.packet.type == INTEL_PT_PAD);
 641
 642                ret = cb(&pkt_info);
 643                if (ret)
 644                        return 0;
 645
 646                pkt_info.last_packet_type = pkt_info.packet.type;
 647        }
 648}
 649
 650struct intel_pt_calc_cyc_to_tsc_info {
 651        uint64_t        cycle_cnt;
 652        unsigned int    cbr;
 653        uint32_t        last_mtc;
 654        uint64_t        ctc_timestamp;
 655        uint64_t        ctc_delta;
 656        uint64_t        tsc_timestamp;
 657        uint64_t        timestamp;
 658        bool            have_tma;
 659        bool            fixup_last_mtc;
 660        bool            from_mtc;
 661        double          cbr_cyc_to_tsc;
 662};
 663
 664/*
 665 * MTC provides a 8-bit slice of CTC but the TMA packet only provides the lower
 666 * 16 bits of CTC. If mtc_shift > 8 then some of the MTC bits are not in the CTC
 667 * provided by the TMA packet. Fix-up the last_mtc calculated from the TMA
 668 * packet by copying the missing bits from the current MTC assuming the least
 669 * difference between the two, and that the current MTC comes after last_mtc.
 670 */
 671static void intel_pt_fixup_last_mtc(uint32_t mtc, int mtc_shift,
 672                                    uint32_t *last_mtc)
 673{
 674        uint32_t first_missing_bit = 1U << (16 - mtc_shift);
 675        uint32_t mask = ~(first_missing_bit - 1);
 676
 677        *last_mtc |= mtc & mask;
 678        if (*last_mtc >= mtc) {
 679                *last_mtc -= first_missing_bit;
 680                *last_mtc &= 0xff;
 681        }
 682}
 683
 684static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
 685{
 686        struct intel_pt_decoder *decoder = pkt_info->decoder;
 687        struct intel_pt_calc_cyc_to_tsc_info *data = pkt_info->data;
 688        uint64_t timestamp;
 689        double cyc_to_tsc;
 690        unsigned int cbr;
 691        uint32_t mtc, mtc_delta, ctc, fc, ctc_rem;
 692
 693        switch (pkt_info->packet.type) {
 694        case INTEL_PT_TNT:
 695        case INTEL_PT_TIP_PGE:
 696        case INTEL_PT_TIP:
 697        case INTEL_PT_FUP:
 698        case INTEL_PT_PSB:
 699        case INTEL_PT_PIP:
 700        case INTEL_PT_MODE_EXEC:
 701        case INTEL_PT_MODE_TSX:
 702        case INTEL_PT_PSBEND:
 703        case INTEL_PT_PAD:
 704        case INTEL_PT_VMCS:
 705        case INTEL_PT_MNT:
 706        case INTEL_PT_PTWRITE:
 707        case INTEL_PT_PTWRITE_IP:
 708        case INTEL_PT_BBP:
 709        case INTEL_PT_BIP:
 710        case INTEL_PT_BEP:
 711        case INTEL_PT_BEP_IP:
 712                return 0;
 713
 714        case INTEL_PT_MTC:
 715                if (!data->have_tma)
 716                        return 0;
 717
 718                mtc = pkt_info->packet.payload;
 719                if (decoder->mtc_shift > 8 && data->fixup_last_mtc) {
 720                        data->fixup_last_mtc = false;
 721                        intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
 722                                                &data->last_mtc);
 723                }
 724                if (mtc > data->last_mtc)
 725                        mtc_delta = mtc - data->last_mtc;
 726                else
 727                        mtc_delta = mtc + 256 - data->last_mtc;
 728                data->ctc_delta += mtc_delta << decoder->mtc_shift;
 729                data->last_mtc = mtc;
 730
 731                if (decoder->tsc_ctc_mult) {
 732                        timestamp = data->ctc_timestamp +
 733                                data->ctc_delta * decoder->tsc_ctc_mult;
 734                } else {
 735                        timestamp = data->ctc_timestamp +
 736                                multdiv(data->ctc_delta,
 737                                        decoder->tsc_ctc_ratio_n,
 738                                        decoder->tsc_ctc_ratio_d);
 739                }
 740
 741                if (timestamp < data->timestamp)
 742                        return 1;
 743
 744                if (pkt_info->last_packet_type != INTEL_PT_CYC) {
 745                        data->timestamp = timestamp;
 746                        return 0;
 747                }
 748
 749                break;
 750
 751        case INTEL_PT_TSC:
 752                /*
 753                 * For now, do not support using TSC packets - refer
 754                 * intel_pt_calc_cyc_to_tsc().
 755                 */
 756                if (data->from_mtc)
 757                        return 1;
 758                timestamp = pkt_info->packet.payload |
 759                            (data->timestamp & (0xffULL << 56));
 760                if (data->from_mtc && timestamp < data->timestamp &&
 761                    data->timestamp - timestamp < decoder->tsc_slip)
 762                        return 1;
 763                if (timestamp < data->timestamp)
 764                        timestamp += (1ULL << 56);
 765                if (pkt_info->last_packet_type != INTEL_PT_CYC) {
 766                        if (data->from_mtc)
 767                                return 1;
 768                        data->tsc_timestamp = timestamp;
 769                        data->timestamp = timestamp;
 770                        return 0;
 771                }
 772                break;
 773
 774        case INTEL_PT_TMA:
 775                if (data->from_mtc)
 776                        return 1;
 777
 778                if (!decoder->tsc_ctc_ratio_d)
 779                        return 0;
 780
 781                ctc = pkt_info->packet.payload;
 782                fc = pkt_info->packet.count;
 783                ctc_rem = ctc & decoder->ctc_rem_mask;
 784
 785                data->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
 786
 787                data->ctc_timestamp = data->tsc_timestamp - fc;
 788                if (decoder->tsc_ctc_mult) {
 789                        data->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
 790                } else {
 791                        data->ctc_timestamp -=
 792                                multdiv(ctc_rem, decoder->tsc_ctc_ratio_n,
 793                                        decoder->tsc_ctc_ratio_d);
 794                }
 795
 796                data->ctc_delta = 0;
 797                data->have_tma = true;
 798                data->fixup_last_mtc = true;
 799
 800                return 0;
 801
 802        case INTEL_PT_CYC:
 803                data->cycle_cnt += pkt_info->packet.payload;
 804                return 0;
 805
 806        case INTEL_PT_CBR:
 807                cbr = pkt_info->packet.payload;
 808                if (data->cbr && data->cbr != cbr)
 809                        return 1;
 810                data->cbr = cbr;
 811                data->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
 812                return 0;
 813
 814        case INTEL_PT_TIP_PGD:
 815        case INTEL_PT_TRACESTOP:
 816        case INTEL_PT_EXSTOP:
 817        case INTEL_PT_EXSTOP_IP:
 818        case INTEL_PT_MWAIT:
 819        case INTEL_PT_PWRE:
 820        case INTEL_PT_PWRX:
 821        case INTEL_PT_OVF:
 822        case INTEL_PT_BAD: /* Does not happen */
 823        default:
 824                return 1;
 825        }
 826
 827        if (!data->cbr && decoder->cbr) {
 828                data->cbr = decoder->cbr;
 829                data->cbr_cyc_to_tsc = decoder->cbr_cyc_to_tsc;
 830        }
 831
 832        if (!data->cycle_cnt)
 833                return 1;
 834
 835        cyc_to_tsc = (double)(timestamp - decoder->timestamp) / data->cycle_cnt;
 836
 837        if (data->cbr && cyc_to_tsc > data->cbr_cyc_to_tsc &&
 838            cyc_to_tsc / data->cbr_cyc_to_tsc > 1.25) {
 839                intel_pt_log("Timestamp: calculated %g TSC ticks per cycle too big (c.f. CBR-based value %g), pos " x64_fmt "\n",
 840                             cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
 841                return 1;
 842        }
 843
 844        decoder->calc_cyc_to_tsc = cyc_to_tsc;
 845        decoder->have_calc_cyc_to_tsc = true;
 846
 847        if (data->cbr) {
 848                intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. CBR-based value %g, pos " x64_fmt "\n",
 849                             cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
 850        } else {
 851                intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. unknown CBR-based value, pos " x64_fmt "\n",
 852                             cyc_to_tsc, pkt_info->pos);
 853        }
 854
 855        return 1;
 856}
 857
 858static void intel_pt_calc_cyc_to_tsc(struct intel_pt_decoder *decoder,
 859                                     bool from_mtc)
 860{
 861        struct intel_pt_calc_cyc_to_tsc_info data = {
 862                .cycle_cnt      = 0,
 863                .cbr            = 0,
 864                .last_mtc       = decoder->last_mtc,
 865                .ctc_timestamp  = decoder->ctc_timestamp,
 866                .ctc_delta      = decoder->ctc_delta,
 867                .tsc_timestamp  = decoder->tsc_timestamp,
 868                .timestamp      = decoder->timestamp,
 869                .have_tma       = decoder->have_tma,
 870                .fixup_last_mtc = decoder->fixup_last_mtc,
 871                .from_mtc       = from_mtc,
 872                .cbr_cyc_to_tsc = 0,
 873        };
 874
 875        /*
 876         * For now, do not support using TSC packets for at least the reasons:
 877         * 1) timing might have stopped
 878         * 2) TSC packets within PSB+ can slip against CYC packets
 879         */
 880        if (!from_mtc)
 881                return;
 882
 883        intel_pt_pkt_lookahead(decoder, intel_pt_calc_cyc_cb, &data);
 884}
 885
 886static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder)
 887{
 888        int ret;
 889
 890        decoder->last_packet_type = decoder->packet.type;
 891
 892        do {
 893                decoder->pos += decoder->pkt_step;
 894                decoder->buf += decoder->pkt_step;
 895                decoder->len -= decoder->pkt_step;
 896
 897                if (!decoder->len) {
 898                        ret = intel_pt_get_next_data(decoder, false);
 899                        if (ret)
 900                                return ret;
 901                }
 902
 903                decoder->prev_pkt_ctx = decoder->pkt_ctx;
 904                ret = intel_pt_get_packet(decoder->buf, decoder->len,
 905                                          &decoder->packet, &decoder->pkt_ctx);
 906                if (ret == INTEL_PT_NEED_MORE_BYTES && BITS_PER_LONG == 32 &&
 907                    decoder->len < INTEL_PT_PKT_MAX_SZ && !decoder->next_buf) {
 908                        ret = intel_pt_get_split_packet(decoder);
 909                        if (ret < 0)
 910                                return ret;
 911                }
 912                if (ret <= 0)
 913                        return intel_pt_bad_packet(decoder);
 914
 915                decoder->pkt_len = ret;
 916                decoder->pkt_step = ret;
 917                intel_pt_decoder_log_packet(decoder);
 918        } while (decoder->packet.type == INTEL_PT_PAD);
 919
 920        return 0;
 921}
 922
 923static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder)
 924{
 925        uint64_t timestamp, masked_timestamp;
 926
 927        timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
 928        masked_timestamp = timestamp & decoder->period_mask;
 929        if (decoder->continuous_period) {
 930                if (masked_timestamp > decoder->last_masked_timestamp)
 931                        return 1;
 932        } else {
 933                timestamp += 1;
 934                masked_timestamp = timestamp & decoder->period_mask;
 935                if (masked_timestamp > decoder->last_masked_timestamp) {
 936                        decoder->last_masked_timestamp = masked_timestamp;
 937                        decoder->continuous_period = true;
 938                }
 939        }
 940
 941        if (masked_timestamp < decoder->last_masked_timestamp)
 942                return decoder->period_ticks;
 943
 944        return decoder->period_ticks - (timestamp - masked_timestamp);
 945}
 946
 947static uint64_t intel_pt_next_sample(struct intel_pt_decoder *decoder)
 948{
 949        switch (decoder->period_type) {
 950        case INTEL_PT_PERIOD_INSTRUCTIONS:
 951                return decoder->period - decoder->period_insn_cnt;
 952        case INTEL_PT_PERIOD_TICKS:
 953                return intel_pt_next_period(decoder);
 954        case INTEL_PT_PERIOD_NONE:
 955        case INTEL_PT_PERIOD_MTC:
 956        default:
 957                return 0;
 958        }
 959}
 960
 961static void intel_pt_sample_insn(struct intel_pt_decoder *decoder)
 962{
 963        uint64_t timestamp, masked_timestamp;
 964
 965        switch (decoder->period_type) {
 966        case INTEL_PT_PERIOD_INSTRUCTIONS:
 967                decoder->period_insn_cnt = 0;
 968                break;
 969        case INTEL_PT_PERIOD_TICKS:
 970                timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
 971                masked_timestamp = timestamp & decoder->period_mask;
 972                if (masked_timestamp > decoder->last_masked_timestamp)
 973                        decoder->last_masked_timestamp = masked_timestamp;
 974                else
 975                        decoder->last_masked_timestamp += decoder->period_ticks;
 976                break;
 977        case INTEL_PT_PERIOD_NONE:
 978        case INTEL_PT_PERIOD_MTC:
 979        default:
 980                break;
 981        }
 982
 983        decoder->state.type |= INTEL_PT_INSTRUCTION;
 984}
 985
 986static int intel_pt_walk_insn(struct intel_pt_decoder *decoder,
 987                              struct intel_pt_insn *intel_pt_insn, uint64_t ip)
 988{
 989        uint64_t max_insn_cnt, insn_cnt = 0;
 990        int err;
 991
 992        if (!decoder->mtc_insn)
 993                decoder->mtc_insn = true;
 994
 995        max_insn_cnt = intel_pt_next_sample(decoder);
 996
 997        err = decoder->walk_insn(intel_pt_insn, &insn_cnt, &decoder->ip, ip,
 998                                 max_insn_cnt, decoder->data);
 999
1000        decoder->tot_insn_cnt += insn_cnt;
1001        decoder->timestamp_insn_cnt += insn_cnt;
1002        decoder->sample_insn_cnt += insn_cnt;
1003        decoder->period_insn_cnt += insn_cnt;
1004
1005        if (err) {
1006                decoder->no_progress = 0;
1007                decoder->pkt_state = INTEL_PT_STATE_ERR2;
1008                intel_pt_log_at("ERROR: Failed to get instruction",
1009                                decoder->ip);
1010                if (err == -ENOENT)
1011                        return -ENOLINK;
1012                return -EILSEQ;
1013        }
1014
1015        if (ip && decoder->ip == ip) {
1016                err = -EAGAIN;
1017                goto out;
1018        }
1019
1020        if (max_insn_cnt && insn_cnt >= max_insn_cnt)
1021                intel_pt_sample_insn(decoder);
1022
1023        if (intel_pt_insn->branch == INTEL_PT_BR_NO_BRANCH) {
1024                decoder->state.type = INTEL_PT_INSTRUCTION;
1025                decoder->state.from_ip = decoder->ip;
1026                decoder->state.to_ip = 0;
1027                decoder->ip += intel_pt_insn->length;
1028                err = INTEL_PT_RETURN;
1029                goto out;
1030        }
1031
1032        if (intel_pt_insn->op == INTEL_PT_OP_CALL) {
1033                /* Zero-length calls are excluded */
1034                if (intel_pt_insn->branch != INTEL_PT_BR_UNCONDITIONAL ||
1035                    intel_pt_insn->rel) {
1036                        err = intel_pt_push(&decoder->stack, decoder->ip +
1037                                            intel_pt_insn->length);
1038                        if (err)
1039                                goto out;
1040                }
1041        } else if (intel_pt_insn->op == INTEL_PT_OP_RET) {
1042                decoder->ret_addr = intel_pt_pop(&decoder->stack);
1043        }
1044
1045        if (intel_pt_insn->branch == INTEL_PT_BR_UNCONDITIONAL) {
1046                int cnt = decoder->no_progress++;
1047
1048                decoder->state.from_ip = decoder->ip;
1049                decoder->ip += intel_pt_insn->length +
1050                                intel_pt_insn->rel;
1051                decoder->state.to_ip = decoder->ip;
1052                err = INTEL_PT_RETURN;
1053
1054                /*
1055                 * Check for being stuck in a loop.  This can happen if a
1056                 * decoder error results in the decoder erroneously setting the
1057                 * ip to an address that is itself in an infinite loop that
1058                 * consumes no packets.  When that happens, there must be an
1059                 * unconditional branch.
1060                 */
1061                if (cnt) {
1062                        if (cnt == 1) {
1063                                decoder->stuck_ip = decoder->state.to_ip;
1064                                decoder->stuck_ip_prd = 1;
1065                                decoder->stuck_ip_cnt = 1;
1066                        } else if (cnt > INTEL_PT_MAX_LOOPS ||
1067                                   decoder->state.to_ip == decoder->stuck_ip) {
1068                                intel_pt_log_at("ERROR: Never-ending loop",
1069                                                decoder->state.to_ip);
1070                                decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1071                                err = -ELOOP;
1072                                goto out;
1073                        } else if (!--decoder->stuck_ip_cnt) {
1074                                decoder->stuck_ip_prd += 1;
1075                                decoder->stuck_ip_cnt = decoder->stuck_ip_prd;
1076                                decoder->stuck_ip = decoder->state.to_ip;
1077                        }
1078                }
1079                goto out_no_progress;
1080        }
1081out:
1082        decoder->no_progress = 0;
1083out_no_progress:
1084        decoder->state.insn_op = intel_pt_insn->op;
1085        decoder->state.insn_len = intel_pt_insn->length;
1086        memcpy(decoder->state.insn, intel_pt_insn->buf,
1087               INTEL_PT_INSN_BUF_SZ);
1088
1089        if (decoder->tx_flags & INTEL_PT_IN_TX)
1090                decoder->state.flags |= INTEL_PT_IN_TX;
1091
1092        return err;
1093}
1094
1095static bool intel_pt_fup_event(struct intel_pt_decoder *decoder)
1096{
1097        bool ret = false;
1098
1099        if (decoder->set_fup_tx_flags) {
1100                decoder->set_fup_tx_flags = false;
1101                decoder->tx_flags = decoder->fup_tx_flags;
1102                decoder->state.type = INTEL_PT_TRANSACTION;
1103                decoder->state.from_ip = decoder->ip;
1104                decoder->state.to_ip = 0;
1105                decoder->state.flags = decoder->fup_tx_flags;
1106                return true;
1107        }
1108        if (decoder->set_fup_ptw) {
1109                decoder->set_fup_ptw = false;
1110                decoder->state.type = INTEL_PT_PTW;
1111                decoder->state.flags |= INTEL_PT_FUP_IP;
1112                decoder->state.from_ip = decoder->ip;
1113                decoder->state.to_ip = 0;
1114                decoder->state.ptw_payload = decoder->fup_ptw_payload;
1115                return true;
1116        }
1117        if (decoder->set_fup_mwait) {
1118                decoder->set_fup_mwait = false;
1119                decoder->state.type = INTEL_PT_MWAIT_OP;
1120                decoder->state.from_ip = decoder->ip;
1121                decoder->state.to_ip = 0;
1122                decoder->state.mwait_payload = decoder->fup_mwait_payload;
1123                ret = true;
1124        }
1125        if (decoder->set_fup_pwre) {
1126                decoder->set_fup_pwre = false;
1127                decoder->state.type |= INTEL_PT_PWR_ENTRY;
1128                decoder->state.type &= ~INTEL_PT_BRANCH;
1129                decoder->state.from_ip = decoder->ip;
1130                decoder->state.to_ip = 0;
1131                decoder->state.pwre_payload = decoder->fup_pwre_payload;
1132                ret = true;
1133        }
1134        if (decoder->set_fup_exstop) {
1135                decoder->set_fup_exstop = false;
1136                decoder->state.type |= INTEL_PT_EX_STOP;
1137                decoder->state.type &= ~INTEL_PT_BRANCH;
1138                decoder->state.flags |= INTEL_PT_FUP_IP;
1139                decoder->state.from_ip = decoder->ip;
1140                decoder->state.to_ip = 0;
1141                ret = true;
1142        }
1143        if (decoder->set_fup_bep) {
1144                decoder->set_fup_bep = false;
1145                decoder->state.type |= INTEL_PT_BLK_ITEMS;
1146                decoder->state.type &= ~INTEL_PT_BRANCH;
1147                decoder->state.from_ip = decoder->ip;
1148                decoder->state.to_ip = 0;
1149                ret = true;
1150        }
1151        return ret;
1152}
1153
1154static inline bool intel_pt_fup_with_nlip(struct intel_pt_decoder *decoder,
1155                                          struct intel_pt_insn *intel_pt_insn,
1156                                          uint64_t ip, int err)
1157{
1158        return decoder->flags & INTEL_PT_FUP_WITH_NLIP && !err &&
1159               intel_pt_insn->branch == INTEL_PT_BR_INDIRECT &&
1160               ip == decoder->ip + intel_pt_insn->length;
1161}
1162
1163static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
1164{
1165        struct intel_pt_insn intel_pt_insn;
1166        uint64_t ip;
1167        int err;
1168
1169        ip = decoder->last_ip;
1170
1171        while (1) {
1172                err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip);
1173                if (err == INTEL_PT_RETURN)
1174                        return 0;
1175                if (err == -EAGAIN ||
1176                    intel_pt_fup_with_nlip(decoder, &intel_pt_insn, ip, err)) {
1177                        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1178                        if (intel_pt_fup_event(decoder))
1179                                return 0;
1180                        return -EAGAIN;
1181                }
1182                decoder->set_fup_tx_flags = false;
1183                if (err)
1184                        return err;
1185
1186                if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1187                        intel_pt_log_at("ERROR: Unexpected indirect branch",
1188                                        decoder->ip);
1189                        decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1190                        return -ENOENT;
1191                }
1192
1193                if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1194                        intel_pt_log_at("ERROR: Unexpected conditional branch",
1195                                        decoder->ip);
1196                        decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1197                        return -ENOENT;
1198                }
1199
1200                intel_pt_bug(decoder);
1201        }
1202}
1203
1204static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
1205{
1206        struct intel_pt_insn intel_pt_insn;
1207        int err;
1208
1209        err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1210        if (err == INTEL_PT_RETURN &&
1211            decoder->pgd_ip &&
1212            decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1213            (decoder->state.type & INTEL_PT_BRANCH) &&
1214            decoder->pgd_ip(decoder->state.to_ip, decoder->data)) {
1215                /* Unconditional branch leaving filter region */
1216                decoder->no_progress = 0;
1217                decoder->pge = false;
1218                decoder->continuous_period = false;
1219                decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1220                decoder->state.type |= INTEL_PT_TRACE_END;
1221                return 0;
1222        }
1223        if (err == INTEL_PT_RETURN)
1224                return 0;
1225        if (err)
1226                return err;
1227
1228        if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1229                if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) {
1230                        decoder->pge = false;
1231                        decoder->continuous_period = false;
1232                        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1233                        decoder->state.from_ip = decoder->ip;
1234                        if (decoder->packet.count == 0) {
1235                                decoder->state.to_ip = 0;
1236                        } else {
1237                                decoder->state.to_ip = decoder->last_ip;
1238                                decoder->ip = decoder->last_ip;
1239                        }
1240                        decoder->state.type |= INTEL_PT_TRACE_END;
1241                } else {
1242                        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1243                        decoder->state.from_ip = decoder->ip;
1244                        if (decoder->packet.count == 0) {
1245                                decoder->state.to_ip = 0;
1246                        } else {
1247                                decoder->state.to_ip = decoder->last_ip;
1248                                decoder->ip = decoder->last_ip;
1249                        }
1250                }
1251                return 0;
1252        }
1253
1254        if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1255                uint64_t to_ip = decoder->ip + intel_pt_insn.length +
1256                                 intel_pt_insn.rel;
1257
1258                if (decoder->pgd_ip &&
1259                    decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
1260                    decoder->pgd_ip(to_ip, decoder->data)) {
1261                        /* Conditional branch leaving filter region */
1262                        decoder->pge = false;
1263                        decoder->continuous_period = false;
1264                        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1265                        decoder->ip = to_ip;
1266                        decoder->state.from_ip = decoder->ip;
1267                        decoder->state.to_ip = to_ip;
1268                        decoder->state.type |= INTEL_PT_TRACE_END;
1269                        return 0;
1270                }
1271                intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch",
1272                                decoder->ip);
1273                decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1274                return -ENOENT;
1275        }
1276
1277        return intel_pt_bug(decoder);
1278}
1279
1280static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
1281{
1282        struct intel_pt_insn intel_pt_insn;
1283        int err;
1284
1285        while (1) {
1286                err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
1287                if (err == INTEL_PT_RETURN)
1288                        return 0;
1289                if (err)
1290                        return err;
1291
1292                if (intel_pt_insn.op == INTEL_PT_OP_RET) {
1293                        if (!decoder->return_compression) {
1294                                intel_pt_log_at("ERROR: RET when expecting conditional branch",
1295                                                decoder->ip);
1296                                decoder->pkt_state = INTEL_PT_STATE_ERR3;
1297                                return -ENOENT;
1298                        }
1299                        if (!decoder->ret_addr) {
1300                                intel_pt_log_at("ERROR: Bad RET compression (stack empty)",
1301                                                decoder->ip);
1302                                decoder->pkt_state = INTEL_PT_STATE_ERR3;
1303                                return -ENOENT;
1304                        }
1305                        if (!(decoder->tnt.payload & BIT63)) {
1306                                intel_pt_log_at("ERROR: Bad RET compression (TNT=N)",
1307                                                decoder->ip);
1308                                decoder->pkt_state = INTEL_PT_STATE_ERR3;
1309                                return -ENOENT;
1310                        }
1311                        decoder->tnt.count -= 1;
1312                        if (decoder->tnt.count)
1313                                decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
1314                        else
1315                                decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1316                        decoder->tnt.payload <<= 1;
1317                        decoder->state.from_ip = decoder->ip;
1318                        decoder->ip = decoder->ret_addr;
1319                        decoder->state.to_ip = decoder->ip;
1320                        return 0;
1321                }
1322
1323                if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
1324                        /* Handle deferred TIPs */
1325                        err = intel_pt_get_next_packet(decoder);
1326                        if (err)
1327                                return err;
1328                        if (decoder->packet.type != INTEL_PT_TIP ||
1329                            decoder->packet.count == 0) {
1330                                intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch",
1331                                                decoder->ip);
1332                                decoder->pkt_state = INTEL_PT_STATE_ERR3;
1333                                decoder->pkt_step = 0;
1334                                return -ENOENT;
1335                        }
1336                        intel_pt_set_last_ip(decoder);
1337                        decoder->state.from_ip = decoder->ip;
1338                        decoder->state.to_ip = decoder->last_ip;
1339                        decoder->ip = decoder->last_ip;
1340                        return 0;
1341                }
1342
1343                if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
1344                        decoder->tnt.count -= 1;
1345                        if (decoder->tnt.count)
1346                                decoder->pkt_state = INTEL_PT_STATE_TNT_CONT;
1347                        else
1348                                decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1349                        if (decoder->tnt.payload & BIT63) {
1350                                decoder->tnt.payload <<= 1;
1351                                decoder->state.from_ip = decoder->ip;
1352                                decoder->ip += intel_pt_insn.length +
1353                                               intel_pt_insn.rel;
1354                                decoder->state.to_ip = decoder->ip;
1355                                return 0;
1356                        }
1357                        /* Instruction sample for a non-taken branch */
1358                        if (decoder->state.type & INTEL_PT_INSTRUCTION) {
1359                                decoder->tnt.payload <<= 1;
1360                                decoder->state.type = INTEL_PT_INSTRUCTION;
1361                                decoder->state.from_ip = decoder->ip;
1362                                decoder->state.to_ip = 0;
1363                                decoder->ip += intel_pt_insn.length;
1364                                return 0;
1365                        }
1366                        decoder->sample_cyc = false;
1367                        decoder->ip += intel_pt_insn.length;
1368                        if (!decoder->tnt.count) {
1369                                intel_pt_update_sample_time(decoder);
1370                                return -EAGAIN;
1371                        }
1372                        decoder->tnt.payload <<= 1;
1373                        continue;
1374                }
1375
1376                return intel_pt_bug(decoder);
1377        }
1378}
1379
1380static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
1381{
1382        unsigned int fup_tx_flags;
1383        int err;
1384
1385        fup_tx_flags = decoder->packet.payload &
1386                       (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX);
1387        err = intel_pt_get_next_packet(decoder);
1388        if (err)
1389                return err;
1390        if (decoder->packet.type == INTEL_PT_FUP) {
1391                decoder->fup_tx_flags = fup_tx_flags;
1392                decoder->set_fup_tx_flags = true;
1393                if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX))
1394                        *no_tip = true;
1395        } else {
1396                intel_pt_log_at("ERROR: Missing FUP after MODE.TSX",
1397                                decoder->pos);
1398                intel_pt_update_in_tx(decoder);
1399        }
1400        return 0;
1401}
1402
1403static uint64_t intel_pt_8b_tsc(uint64_t timestamp, uint64_t ref_timestamp)
1404{
1405        timestamp |= (ref_timestamp & (0xffULL << 56));
1406
1407        if (timestamp < ref_timestamp) {
1408                if (ref_timestamp - timestamp > (1ULL << 55))
1409                        timestamp += (1ULL << 56);
1410        } else {
1411                if (timestamp - ref_timestamp > (1ULL << 55))
1412                        timestamp -= (1ULL << 56);
1413        }
1414
1415        return timestamp;
1416}
1417
1418static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
1419{
1420        uint64_t timestamp;
1421
1422        decoder->have_tma = false;
1423
1424        if (decoder->ref_timestamp) {
1425                timestamp = intel_pt_8b_tsc(decoder->packet.payload,
1426                                            decoder->ref_timestamp);
1427                decoder->tsc_timestamp = timestamp;
1428                decoder->timestamp = timestamp;
1429                decoder->ref_timestamp = 0;
1430                decoder->timestamp_insn_cnt = 0;
1431        } else if (decoder->timestamp) {
1432                timestamp = decoder->packet.payload |
1433                            (decoder->timestamp & (0xffULL << 56));
1434                decoder->tsc_timestamp = timestamp;
1435                if (timestamp < decoder->timestamp &&
1436                    decoder->timestamp - timestamp < decoder->tsc_slip) {
1437                        intel_pt_log_to("Suppressing backwards timestamp",
1438                                        timestamp);
1439                        timestamp = decoder->timestamp;
1440                }
1441                if (timestamp < decoder->timestamp) {
1442                        intel_pt_log_to("Wraparound timestamp", timestamp);
1443                        timestamp += (1ULL << 56);
1444                        decoder->tsc_timestamp = timestamp;
1445                }
1446                decoder->timestamp = timestamp;
1447                decoder->timestamp_insn_cnt = 0;
1448        }
1449
1450        if (decoder->last_packet_type == INTEL_PT_CYC) {
1451                decoder->cyc_ref_timestamp = decoder->timestamp;
1452                decoder->cycle_cnt = 0;
1453                decoder->have_calc_cyc_to_tsc = false;
1454                intel_pt_calc_cyc_to_tsc(decoder, false);
1455        }
1456
1457        intel_pt_log_to("Setting timestamp", decoder->timestamp);
1458}
1459
1460static int intel_pt_overflow(struct intel_pt_decoder *decoder)
1461{
1462        intel_pt_log("ERROR: Buffer overflow\n");
1463        intel_pt_clear_tx_flags(decoder);
1464        decoder->timestamp_insn_cnt = 0;
1465        decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
1466        decoder->overflow = true;
1467        return -EOVERFLOW;
1468}
1469
1470static inline void intel_pt_mtc_cyc_cnt_pge(struct intel_pt_decoder *decoder)
1471{
1472        if (decoder->have_cyc)
1473                return;
1474
1475        decoder->cyc_cnt_timestamp = decoder->timestamp;
1476        decoder->base_cyc_cnt = decoder->tot_cyc_cnt;
1477}
1478
1479static inline void intel_pt_mtc_cyc_cnt_cbr(struct intel_pt_decoder *decoder)
1480{
1481        decoder->tsc_to_cyc = decoder->cbr / decoder->max_non_turbo_ratio_fp;
1482
1483        if (decoder->pge)
1484                intel_pt_mtc_cyc_cnt_pge(decoder);
1485}
1486
1487static inline void intel_pt_mtc_cyc_cnt_upd(struct intel_pt_decoder *decoder)
1488{
1489        uint64_t tot_cyc_cnt, tsc_delta;
1490
1491        if (decoder->have_cyc)
1492                return;
1493
1494        decoder->sample_cyc = true;
1495
1496        if (!decoder->pge || decoder->timestamp <= decoder->cyc_cnt_timestamp)
1497                return;
1498
1499        tsc_delta = decoder->timestamp - decoder->cyc_cnt_timestamp;
1500        tot_cyc_cnt = tsc_delta * decoder->tsc_to_cyc + decoder->base_cyc_cnt;
1501
1502        if (tot_cyc_cnt > decoder->tot_cyc_cnt)
1503                decoder->tot_cyc_cnt = tot_cyc_cnt;
1504}
1505
1506static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
1507{
1508        uint32_t ctc = decoder->packet.payload;
1509        uint32_t fc = decoder->packet.count;
1510        uint32_t ctc_rem = ctc & decoder->ctc_rem_mask;
1511
1512        if (!decoder->tsc_ctc_ratio_d)
1513                return;
1514
1515        if (decoder->pge && !decoder->in_psb)
1516                intel_pt_mtc_cyc_cnt_pge(decoder);
1517        else
1518                intel_pt_mtc_cyc_cnt_upd(decoder);
1519
1520        decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
1521        decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
1522        if (decoder->tsc_ctc_mult) {
1523                decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
1524        } else {
1525                decoder->ctc_timestamp -= multdiv(ctc_rem,
1526                                                  decoder->tsc_ctc_ratio_n,
1527                                                  decoder->tsc_ctc_ratio_d);
1528        }
1529        decoder->ctc_delta = 0;
1530        decoder->have_tma = true;
1531        decoder->fixup_last_mtc = true;
1532        intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x  CTC rem %#x\n",
1533                     decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
1534}
1535
1536static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
1537{
1538        uint64_t timestamp;
1539        uint32_t mtc, mtc_delta;
1540
1541        if (!decoder->have_tma)
1542                return;
1543
1544        mtc = decoder->packet.payload;
1545
1546        if (decoder->mtc_shift > 8 && decoder->fixup_last_mtc) {
1547                decoder->fixup_last_mtc = false;
1548                intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
1549                                        &decoder->last_mtc);
1550        }
1551
1552        if (mtc > decoder->last_mtc)
1553                mtc_delta = mtc - decoder->last_mtc;
1554        else
1555                mtc_delta = mtc + 256 - decoder->last_mtc;
1556
1557        decoder->ctc_delta += mtc_delta << decoder->mtc_shift;
1558
1559        if (decoder->tsc_ctc_mult) {
1560                timestamp = decoder->ctc_timestamp +
1561                            decoder->ctc_delta * decoder->tsc_ctc_mult;
1562        } else {
1563                timestamp = decoder->ctc_timestamp +
1564                            multdiv(decoder->ctc_delta,
1565                                    decoder->tsc_ctc_ratio_n,
1566                                    decoder->tsc_ctc_ratio_d);
1567        }
1568
1569        if (timestamp < decoder->timestamp)
1570                intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
1571                             timestamp, decoder->timestamp);
1572        else
1573                decoder->timestamp = timestamp;
1574
1575        intel_pt_mtc_cyc_cnt_upd(decoder);
1576
1577        decoder->timestamp_insn_cnt = 0;
1578        decoder->last_mtc = mtc;
1579
1580        if (decoder->last_packet_type == INTEL_PT_CYC) {
1581                decoder->cyc_ref_timestamp = decoder->timestamp;
1582                decoder->cycle_cnt = 0;
1583                decoder->have_calc_cyc_to_tsc = false;
1584                intel_pt_calc_cyc_to_tsc(decoder, true);
1585        }
1586
1587        intel_pt_log_to("Setting timestamp", decoder->timestamp);
1588}
1589
1590static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)
1591{
1592        unsigned int cbr = decoder->packet.payload & 0xff;
1593
1594        decoder->cbr_payload = decoder->packet.payload;
1595
1596        if (decoder->cbr == cbr)
1597                return;
1598
1599        decoder->cbr = cbr;
1600        decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
1601
1602        intel_pt_mtc_cyc_cnt_cbr(decoder);
1603}
1604
1605static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
1606{
1607        uint64_t timestamp = decoder->cyc_ref_timestamp;
1608
1609        decoder->have_cyc = true;
1610
1611        decoder->cycle_cnt += decoder->packet.payload;
1612        if (decoder->pge)
1613                decoder->tot_cyc_cnt += decoder->packet.payload;
1614        decoder->sample_cyc = true;
1615
1616        if (!decoder->cyc_ref_timestamp)
1617                return;
1618
1619        if (decoder->have_calc_cyc_to_tsc)
1620                timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc;
1621        else if (decoder->cbr)
1622                timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc;
1623        else
1624                return;
1625
1626        if (timestamp < decoder->timestamp)
1627                intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
1628                             timestamp, decoder->timestamp);
1629        else
1630                decoder->timestamp = timestamp;
1631
1632        decoder->timestamp_insn_cnt = 0;
1633
1634        intel_pt_log_to("Setting timestamp", decoder->timestamp);
1635}
1636
1637static void intel_pt_bbp(struct intel_pt_decoder *decoder)
1638{
1639        if (decoder->prev_pkt_ctx == INTEL_PT_NO_CTX) {
1640                memset(decoder->state.items.mask, 0, sizeof(decoder->state.items.mask));
1641                decoder->state.items.is_32_bit = false;
1642        }
1643        decoder->blk_type = decoder->packet.payload;
1644        decoder->blk_type_pos = intel_pt_blk_type_pos(decoder->blk_type);
1645        if (decoder->blk_type == INTEL_PT_GP_REGS)
1646                decoder->state.items.is_32_bit = decoder->packet.count;
1647        if (decoder->blk_type_pos < 0) {
1648                intel_pt_log("WARNING: Unknown block type %u\n",
1649                             decoder->blk_type);
1650        } else if (decoder->state.items.mask[decoder->blk_type_pos]) {
1651                intel_pt_log("WARNING: Duplicate block type %u\n",
1652                             decoder->blk_type);
1653        }
1654}
1655
1656static void intel_pt_bip(struct intel_pt_decoder *decoder)
1657{
1658        uint32_t id = decoder->packet.count;
1659        uint32_t bit = 1 << id;
1660        int pos = decoder->blk_type_pos;
1661
1662        if (pos < 0 || id >= INTEL_PT_BLK_ITEM_ID_CNT) {
1663                intel_pt_log("WARNING: Unknown block item %u type %d\n",
1664                             id, decoder->blk_type);
1665                return;
1666        }
1667
1668        if (decoder->state.items.mask[pos] & bit) {
1669                intel_pt_log("WARNING: Duplicate block item %u type %d\n",
1670                             id, decoder->blk_type);
1671        }
1672
1673        decoder->state.items.mask[pos] |= bit;
1674        decoder->state.items.val[pos][id] = decoder->packet.payload;
1675}
1676
1677/* Walk PSB+ packets when already in sync. */
1678static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
1679{
1680        int err;
1681
1682        decoder->in_psb = true;
1683
1684        while (1) {
1685                err = intel_pt_get_next_packet(decoder);
1686                if (err)
1687                        goto out;
1688
1689                switch (decoder->packet.type) {
1690                case INTEL_PT_PSBEND:
1691                        err = 0;
1692                        goto out;
1693
1694                case INTEL_PT_TIP_PGD:
1695                case INTEL_PT_TIP_PGE:
1696                case INTEL_PT_TIP:
1697                case INTEL_PT_TNT:
1698                case INTEL_PT_TRACESTOP:
1699                case INTEL_PT_BAD:
1700                case INTEL_PT_PSB:
1701                case INTEL_PT_PTWRITE:
1702                case INTEL_PT_PTWRITE_IP:
1703                case INTEL_PT_EXSTOP:
1704                case INTEL_PT_EXSTOP_IP:
1705                case INTEL_PT_MWAIT:
1706                case INTEL_PT_PWRE:
1707                case INTEL_PT_PWRX:
1708                case INTEL_PT_BBP:
1709                case INTEL_PT_BIP:
1710                case INTEL_PT_BEP:
1711                case INTEL_PT_BEP_IP:
1712                        decoder->have_tma = false;
1713                        intel_pt_log("ERROR: Unexpected packet\n");
1714                        err = -EAGAIN;
1715                        goto out;
1716
1717                case INTEL_PT_OVF:
1718                        err = intel_pt_overflow(decoder);
1719                        goto out;
1720
1721                case INTEL_PT_TSC:
1722                        intel_pt_calc_tsc_timestamp(decoder);
1723                        break;
1724
1725                case INTEL_PT_TMA:
1726                        intel_pt_calc_tma(decoder);
1727                        break;
1728
1729                case INTEL_PT_CBR:
1730                        intel_pt_calc_cbr(decoder);
1731                        break;
1732
1733                case INTEL_PT_MODE_EXEC:
1734                        decoder->exec_mode = decoder->packet.payload;
1735                        break;
1736
1737                case INTEL_PT_PIP:
1738                        decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1739                        break;
1740
1741                case INTEL_PT_FUP:
1742                        decoder->pge = true;
1743                        if (decoder->packet.count) {
1744                                intel_pt_set_last_ip(decoder);
1745                                if (decoder->hop) {
1746                                        /* Act on FUP at PSBEND */
1747                                        decoder->ip = decoder->last_ip;
1748                                        decoder->hop_psb_fup = true;
1749                                }
1750                        }
1751                        break;
1752
1753                case INTEL_PT_MODE_TSX:
1754                        intel_pt_update_in_tx(decoder);
1755                        break;
1756
1757                case INTEL_PT_MTC:
1758                        intel_pt_calc_mtc_timestamp(decoder);
1759                        if (decoder->period_type == INTEL_PT_PERIOD_MTC)
1760                                decoder->state.type |= INTEL_PT_INSTRUCTION;
1761                        break;
1762
1763                case INTEL_PT_CYC:
1764                case INTEL_PT_VMCS:
1765                case INTEL_PT_MNT:
1766                case INTEL_PT_PAD:
1767                default:
1768                        break;
1769                }
1770        }
1771out:
1772        decoder->in_psb = false;
1773
1774        return err;
1775}
1776
1777static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
1778{
1779        int err;
1780
1781        if (decoder->tx_flags & INTEL_PT_ABORT_TX) {
1782                decoder->tx_flags = 0;
1783                decoder->state.flags &= ~INTEL_PT_IN_TX;
1784                decoder->state.flags |= INTEL_PT_ABORT_TX;
1785        } else {
1786                decoder->state.flags |= INTEL_PT_ASYNC;
1787        }
1788
1789        while (1) {
1790                err = intel_pt_get_next_packet(decoder);
1791                if (err)
1792                        return err;
1793
1794                switch (decoder->packet.type) {
1795                case INTEL_PT_TNT:
1796                case INTEL_PT_FUP:
1797                case INTEL_PT_TRACESTOP:
1798                case INTEL_PT_PSB:
1799                case INTEL_PT_TSC:
1800                case INTEL_PT_TMA:
1801                case INTEL_PT_MODE_TSX:
1802                case INTEL_PT_BAD:
1803                case INTEL_PT_PSBEND:
1804                case INTEL_PT_PTWRITE:
1805                case INTEL_PT_PTWRITE_IP:
1806                case INTEL_PT_EXSTOP:
1807                case INTEL_PT_EXSTOP_IP:
1808                case INTEL_PT_MWAIT:
1809                case INTEL_PT_PWRE:
1810                case INTEL_PT_PWRX:
1811                case INTEL_PT_BBP:
1812                case INTEL_PT_BIP:
1813                case INTEL_PT_BEP:
1814                case INTEL_PT_BEP_IP:
1815                        intel_pt_log("ERROR: Missing TIP after FUP\n");
1816                        decoder->pkt_state = INTEL_PT_STATE_ERR3;
1817                        decoder->pkt_step = 0;
1818                        return -ENOENT;
1819
1820                case INTEL_PT_CBR:
1821                        intel_pt_calc_cbr(decoder);
1822                        break;
1823
1824                case INTEL_PT_OVF:
1825                        return intel_pt_overflow(decoder);
1826
1827                case INTEL_PT_TIP_PGD:
1828                        decoder->state.from_ip = decoder->ip;
1829                        if (decoder->packet.count == 0) {
1830                                decoder->state.to_ip = 0;
1831                        } else {
1832                                intel_pt_set_ip(decoder);
1833                                decoder->state.to_ip = decoder->ip;
1834                        }
1835                        decoder->pge = false;
1836                        decoder->continuous_period = false;
1837                        decoder->state.type |= INTEL_PT_TRACE_END;
1838                        return 0;
1839
1840                case INTEL_PT_TIP_PGE:
1841                        decoder->pge = true;
1842                        intel_pt_log("Omitting PGE ip " x64_fmt "\n",
1843                                     decoder->ip);
1844                        decoder->state.from_ip = 0;
1845                        if (decoder->packet.count == 0) {
1846                                decoder->state.to_ip = 0;
1847                        } else {
1848                                intel_pt_set_ip(decoder);
1849                                decoder->state.to_ip = decoder->ip;
1850                        }
1851                        decoder->state.type |= INTEL_PT_TRACE_BEGIN;
1852                        intel_pt_mtc_cyc_cnt_pge(decoder);
1853                        return 0;
1854
1855                case INTEL_PT_TIP:
1856                        decoder->state.from_ip = decoder->ip;
1857                        if (decoder->packet.count == 0) {
1858                                decoder->state.to_ip = 0;
1859                        } else {
1860                                intel_pt_set_ip(decoder);
1861                                decoder->state.to_ip = decoder->ip;
1862                        }
1863                        return 0;
1864
1865                case INTEL_PT_PIP:
1866                        decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
1867                        break;
1868
1869                case INTEL_PT_MTC:
1870                        intel_pt_calc_mtc_timestamp(decoder);
1871                        if (decoder->period_type == INTEL_PT_PERIOD_MTC)
1872                                decoder->state.type |= INTEL_PT_INSTRUCTION;
1873                        break;
1874
1875                case INTEL_PT_CYC:
1876                        intel_pt_calc_cyc_timestamp(decoder);
1877                        break;
1878
1879                case INTEL_PT_MODE_EXEC:
1880                        decoder->exec_mode = decoder->packet.payload;
1881                        break;
1882
1883                case INTEL_PT_VMCS:
1884                case INTEL_PT_MNT:
1885                case INTEL_PT_PAD:
1886                        break;
1887
1888                default:
1889                        return intel_pt_bug(decoder);
1890                }
1891        }
1892}
1893
1894static int intel_pt_resample(struct intel_pt_decoder *decoder)
1895{
1896        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
1897        decoder->state.type = INTEL_PT_INSTRUCTION;
1898        decoder->state.from_ip = decoder->ip;
1899        decoder->state.to_ip = 0;
1900        return 0;
1901}
1902
1903#define HOP_PROCESS     0
1904#define HOP_IGNORE      1
1905#define HOP_RETURN      2
1906#define HOP_AGAIN       3
1907
1908static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder);
1909
1910/* Hop mode: Ignore TNT, do not walk code, but get ip from FUPs and TIPs */
1911static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, int *err)
1912{
1913        /* Leap from PSB to PSB, getting ip from FUP within PSB+ */
1914        if (decoder->leap && !decoder->in_psb && decoder->packet.type != INTEL_PT_PSB) {
1915                *err = intel_pt_scan_for_psb(decoder);
1916                if (*err)
1917                        return HOP_RETURN;
1918        }
1919
1920        switch (decoder->packet.type) {
1921        case INTEL_PT_TNT:
1922                return HOP_IGNORE;
1923
1924        case INTEL_PT_TIP_PGD:
1925                if (!decoder->packet.count)
1926                        return HOP_IGNORE;
1927                intel_pt_set_ip(decoder);
1928                decoder->state.type |= INTEL_PT_TRACE_END;
1929                decoder->state.from_ip = 0;
1930                decoder->state.to_ip = decoder->ip;
1931                return HOP_RETURN;
1932
1933        case INTEL_PT_TIP:
1934                if (!decoder->packet.count)
1935                        return HOP_IGNORE;
1936                intel_pt_set_ip(decoder);
1937                decoder->state.type = INTEL_PT_INSTRUCTION;
1938                decoder->state.from_ip = decoder->ip;
1939                decoder->state.to_ip = 0;
1940                return HOP_RETURN;
1941
1942        case INTEL_PT_FUP:
1943                if (!decoder->packet.count)
1944                        return HOP_IGNORE;
1945                intel_pt_set_ip(decoder);
1946                if (intel_pt_fup_event(decoder))
1947                        return HOP_RETURN;
1948                if (!decoder->branch_enable)
1949                        *no_tip = true;
1950                if (*no_tip) {
1951                        decoder->state.type = INTEL_PT_INSTRUCTION;
1952                        decoder->state.from_ip = decoder->ip;
1953                        decoder->state.to_ip = 0;
1954                        return HOP_RETURN;
1955                }
1956                *err = intel_pt_walk_fup_tip(decoder);
1957                if (!*err)
1958                        decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
1959                return HOP_RETURN;
1960
1961        case INTEL_PT_PSB:
1962                decoder->last_ip = 0;
1963                decoder->have_last_ip = true;
1964                decoder->hop_psb_fup = false;
1965                *err = intel_pt_walk_psbend(decoder);
1966                if (*err == -EAGAIN)
1967                        return HOP_AGAIN;
1968                if (*err)
1969                        return HOP_RETURN;
1970                if (decoder->hop_psb_fup) {
1971                        decoder->hop_psb_fup = false;
1972                        decoder->state.type = INTEL_PT_INSTRUCTION;
1973                        decoder->state.from_ip = decoder->ip;
1974                        decoder->state.to_ip = 0;
1975                        return HOP_RETURN;
1976                }
1977                if (decoder->cbr != decoder->cbr_seen) {
1978                        decoder->state.type = 0;
1979                        return HOP_RETURN;
1980                }
1981                return HOP_IGNORE;
1982
1983        case INTEL_PT_BAD:
1984        case INTEL_PT_PAD:
1985        case INTEL_PT_TIP_PGE:
1986        case INTEL_PT_TSC:
1987        case INTEL_PT_TMA:
1988        case INTEL_PT_MODE_EXEC:
1989        case INTEL_PT_MODE_TSX:
1990        case INTEL_PT_MTC:
1991        case INTEL_PT_CYC:
1992        case INTEL_PT_VMCS:
1993        case INTEL_PT_PSBEND:
1994        case INTEL_PT_CBR:
1995        case INTEL_PT_TRACESTOP:
1996        case INTEL_PT_PIP:
1997        case INTEL_PT_OVF:
1998        case INTEL_PT_MNT:
1999        case INTEL_PT_PTWRITE:
2000        case INTEL_PT_PTWRITE_IP:
2001        case INTEL_PT_EXSTOP:
2002        case INTEL_PT_EXSTOP_IP:
2003        case INTEL_PT_MWAIT:
2004        case INTEL_PT_PWRE:
2005        case INTEL_PT_PWRX:
2006        case INTEL_PT_BBP:
2007        case INTEL_PT_BIP:
2008        case INTEL_PT_BEP:
2009        case INTEL_PT_BEP_IP:
2010        default:
2011                return HOP_PROCESS;
2012        }
2013}
2014
2015static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
2016{
2017        bool no_tip = false;
2018        int err;
2019
2020        while (1) {
2021                err = intel_pt_get_next_packet(decoder);
2022                if (err)
2023                        return err;
2024next:
2025                if (decoder->hop) {
2026                        switch (intel_pt_hop_trace(decoder, &no_tip, &err)) {
2027                        case HOP_IGNORE:
2028                                continue;
2029                        case HOP_RETURN:
2030                                return err;
2031                        case HOP_AGAIN:
2032                                goto next;
2033                        default:
2034                                break;
2035                        }
2036                }
2037
2038                switch (decoder->packet.type) {
2039                case INTEL_PT_TNT:
2040                        if (!decoder->packet.count)
2041                                break;
2042                        decoder->tnt = decoder->packet;
2043                        decoder->pkt_state = INTEL_PT_STATE_TNT;
2044                        err = intel_pt_walk_tnt(decoder);
2045                        if (err == -EAGAIN)
2046                                break;
2047                        return err;
2048
2049                case INTEL_PT_TIP_PGD:
2050                        if (decoder->packet.count != 0)
2051                                intel_pt_set_last_ip(decoder);
2052                        decoder->pkt_state = INTEL_PT_STATE_TIP_PGD;
2053                        return intel_pt_walk_tip(decoder);
2054
2055                case INTEL_PT_TIP_PGE: {
2056                        decoder->pge = true;
2057                        intel_pt_mtc_cyc_cnt_pge(decoder);
2058                        if (decoder->packet.count == 0) {
2059                                intel_pt_log_at("Skipping zero TIP.PGE",
2060                                                decoder->pos);
2061                                break;
2062                        }
2063                        intel_pt_set_ip(decoder);
2064                        decoder->state.from_ip = 0;
2065                        decoder->state.to_ip = decoder->ip;
2066                        decoder->state.type |= INTEL_PT_TRACE_BEGIN;
2067                        /*
2068                         * In hop mode, resample to get the to_ip as an
2069                         * "instruction" sample.
2070                         */
2071                        if (decoder->hop)
2072                                decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
2073                        return 0;
2074                }
2075
2076                case INTEL_PT_OVF:
2077                        return intel_pt_overflow(decoder);
2078
2079                case INTEL_PT_TIP:
2080                        if (decoder->packet.count != 0)
2081                                intel_pt_set_last_ip(decoder);
2082                        decoder->pkt_state = INTEL_PT_STATE_TIP;
2083                        return intel_pt_walk_tip(decoder);
2084
2085                case INTEL_PT_FUP:
2086                        if (decoder->packet.count == 0) {
2087                                intel_pt_log_at("Skipping zero FUP",
2088                                                decoder->pos);
2089                                no_tip = false;
2090                                break;
2091                        }
2092                        intel_pt_set_last_ip(decoder);
2093                        if (!decoder->branch_enable) {
2094                                decoder->ip = decoder->last_ip;
2095                                if (intel_pt_fup_event(decoder))
2096                                        return 0;
2097                                no_tip = false;
2098                                break;
2099                        }
2100                        if (decoder->set_fup_mwait)
2101                                no_tip = true;
2102                        if (no_tip)
2103                                decoder->pkt_state = INTEL_PT_STATE_FUP_NO_TIP;
2104                        else
2105                                decoder->pkt_state = INTEL_PT_STATE_FUP;
2106                        err = intel_pt_walk_fup(decoder);
2107                        if (err != -EAGAIN)
2108                                return err;
2109                        if (no_tip) {
2110                                no_tip = false;
2111                                break;
2112                        }
2113                        return intel_pt_walk_fup_tip(decoder);
2114
2115                case INTEL_PT_TRACESTOP:
2116                        decoder->pge = false;
2117                        decoder->continuous_period = false;
2118                        intel_pt_clear_tx_flags(decoder);
2119                        decoder->have_tma = false;
2120                        break;
2121
2122                case INTEL_PT_PSB:
2123                        decoder->last_ip = 0;
2124                        decoder->have_last_ip = true;
2125                        intel_pt_clear_stack(&decoder->stack);
2126                        err = intel_pt_walk_psbend(decoder);
2127                        if (err == -EAGAIN)
2128                                goto next;
2129                        if (err)
2130                                return err;
2131                        /*
2132                         * PSB+ CBR will not have changed but cater for the
2133                         * possibility of another CBR change that gets caught up
2134                         * in the PSB+.
2135                         */
2136                        if (decoder->cbr != decoder->cbr_seen) {
2137                                decoder->state.type = 0;
2138                                return 0;
2139                        }
2140                        break;
2141
2142                case INTEL_PT_PIP:
2143                        decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
2144                        break;
2145
2146                case INTEL_PT_MTC:
2147                        intel_pt_calc_mtc_timestamp(decoder);
2148                        if (decoder->period_type != INTEL_PT_PERIOD_MTC)
2149                                break;
2150                        /*
2151                         * Ensure that there has been an instruction since the
2152                         * last MTC.
2153                         */
2154                        if (!decoder->mtc_insn)
2155                                break;
2156                        decoder->mtc_insn = false;
2157                        /* Ensure that there is a timestamp */
2158                        if (!decoder->timestamp)
2159                                break;
2160                        decoder->state.type = INTEL_PT_INSTRUCTION;
2161                        decoder->state.from_ip = decoder->ip;
2162                        decoder->state.to_ip = 0;
2163                        decoder->mtc_insn = false;
2164                        return 0;
2165
2166                case INTEL_PT_TSC:
2167                        intel_pt_calc_tsc_timestamp(decoder);
2168                        break;
2169
2170                case INTEL_PT_TMA:
2171                        intel_pt_calc_tma(decoder);
2172                        break;
2173
2174                case INTEL_PT_CYC:
2175                        intel_pt_calc_cyc_timestamp(decoder);
2176                        break;
2177
2178                case INTEL_PT_CBR:
2179                        intel_pt_calc_cbr(decoder);
2180                        if (decoder->cbr != decoder->cbr_seen) {
2181                                decoder->state.type = 0;
2182                                return 0;
2183                        }
2184                        break;
2185
2186                case INTEL_PT_MODE_EXEC:
2187                        decoder->exec_mode = decoder->packet.payload;
2188                        break;
2189
2190                case INTEL_PT_MODE_TSX:
2191                        /* MODE_TSX need not be followed by FUP */
2192                        if (!decoder->pge || decoder->in_psb) {
2193                                intel_pt_update_in_tx(decoder);
2194                                break;
2195                        }
2196                        err = intel_pt_mode_tsx(decoder, &no_tip);
2197                        if (err)
2198                                return err;
2199                        goto next;
2200
2201                case INTEL_PT_BAD: /* Does not happen */
2202                        return intel_pt_bug(decoder);
2203
2204                case INTEL_PT_PSBEND:
2205                case INTEL_PT_VMCS:
2206                case INTEL_PT_MNT:
2207                case INTEL_PT_PAD:
2208                        break;
2209
2210                case INTEL_PT_PTWRITE_IP:
2211                        decoder->fup_ptw_payload = decoder->packet.payload;
2212                        err = intel_pt_get_next_packet(decoder);
2213                        if (err)
2214                                return err;
2215                        if (decoder->packet.type == INTEL_PT_FUP) {
2216                                decoder->set_fup_ptw = true;
2217                                no_tip = true;
2218                        } else {
2219                                intel_pt_log_at("ERROR: Missing FUP after PTWRITE",
2220                                                decoder->pos);
2221                        }
2222                        goto next;
2223
2224                case INTEL_PT_PTWRITE:
2225                        decoder->state.type = INTEL_PT_PTW;
2226                        decoder->state.from_ip = decoder->ip;
2227                        decoder->state.to_ip = 0;
2228                        decoder->state.ptw_payload = decoder->packet.payload;
2229                        return 0;
2230
2231                case INTEL_PT_MWAIT:
2232                        decoder->fup_mwait_payload = decoder->packet.payload;
2233                        decoder->set_fup_mwait = true;
2234                        break;
2235
2236                case INTEL_PT_PWRE:
2237                        if (decoder->set_fup_mwait) {
2238                                decoder->fup_pwre_payload =
2239                                                        decoder->packet.payload;
2240                                decoder->set_fup_pwre = true;
2241                                break;
2242                        }
2243                        decoder->state.type = INTEL_PT_PWR_ENTRY;
2244                        decoder->state.from_ip = decoder->ip;
2245                        decoder->state.to_ip = 0;
2246                        decoder->state.pwrx_payload = decoder->packet.payload;
2247                        return 0;
2248
2249                case INTEL_PT_EXSTOP_IP:
2250                        err = intel_pt_get_next_packet(decoder);
2251                        if (err)
2252                                return err;
2253                        if (decoder->packet.type == INTEL_PT_FUP) {
2254                                decoder->set_fup_exstop = true;
2255                                no_tip = true;
2256                        } else {
2257                                intel_pt_log_at("ERROR: Missing FUP after EXSTOP",
2258                                                decoder->pos);
2259                        }
2260                        goto next;
2261
2262                case INTEL_PT_EXSTOP:
2263                        decoder->state.type = INTEL_PT_EX_STOP;
2264                        decoder->state.from_ip = decoder->ip;
2265                        decoder->state.to_ip = 0;
2266                        return 0;
2267
2268                case INTEL_PT_PWRX:
2269                        decoder->state.type = INTEL_PT_PWR_EXIT;
2270                        decoder->state.from_ip = decoder->ip;
2271                        decoder->state.to_ip = 0;
2272                        decoder->state.pwrx_payload = decoder->packet.payload;
2273                        return 0;
2274
2275                case INTEL_PT_BBP:
2276                        intel_pt_bbp(decoder);
2277                        break;
2278
2279                case INTEL_PT_BIP:
2280                        intel_pt_bip(decoder);
2281                        break;
2282
2283                case INTEL_PT_BEP:
2284                        decoder->state.type = INTEL_PT_BLK_ITEMS;
2285                        decoder->state.from_ip = decoder->ip;
2286                        decoder->state.to_ip = 0;
2287                        return 0;
2288
2289                case INTEL_PT_BEP_IP:
2290                        err = intel_pt_get_next_packet(decoder);
2291                        if (err)
2292                                return err;
2293                        if (decoder->packet.type == INTEL_PT_FUP) {
2294                                decoder->set_fup_bep = true;
2295                                no_tip = true;
2296                        } else {
2297                                intel_pt_log_at("ERROR: Missing FUP after BEP",
2298                                                decoder->pos);
2299                        }
2300                        goto next;
2301
2302                default:
2303                        return intel_pt_bug(decoder);
2304                }
2305        }
2306}
2307
2308static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder)
2309{
2310        return decoder->packet.count &&
2311               (decoder->have_last_ip || decoder->packet.count == 3 ||
2312                decoder->packet.count == 6);
2313}
2314
2315/* Walk PSB+ packets to get in sync. */
2316static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
2317{
2318        int err;
2319
2320        decoder->in_psb = true;
2321
2322        while (1) {
2323                err = intel_pt_get_next_packet(decoder);
2324                if (err)
2325                        goto out;
2326
2327                switch (decoder->packet.type) {
2328                case INTEL_PT_TIP_PGD:
2329                        decoder->continuous_period = false;
2330                        __fallthrough;
2331                case INTEL_PT_TIP_PGE:
2332                case INTEL_PT_TIP:
2333                case INTEL_PT_PTWRITE:
2334                case INTEL_PT_PTWRITE_IP:
2335                case INTEL_PT_EXSTOP:
2336                case INTEL_PT_EXSTOP_IP:
2337                case INTEL_PT_MWAIT:
2338                case INTEL_PT_PWRE:
2339                case INTEL_PT_PWRX:
2340                case INTEL_PT_BBP:
2341                case INTEL_PT_BIP:
2342                case INTEL_PT_BEP:
2343                case INTEL_PT_BEP_IP:
2344                        intel_pt_log("ERROR: Unexpected packet\n");
2345                        err = -ENOENT;
2346                        goto out;
2347
2348                case INTEL_PT_FUP:
2349                        decoder->pge = true;
2350                        if (intel_pt_have_ip(decoder)) {
2351                                uint64_t current_ip = decoder->ip;
2352
2353                                intel_pt_set_ip(decoder);
2354                                if (current_ip)
2355                                        intel_pt_log_to("Setting IP",
2356                                                        decoder->ip);
2357                        }
2358                        break;
2359
2360                case INTEL_PT_MTC:
2361                        intel_pt_calc_mtc_timestamp(decoder);
2362                        break;
2363
2364                case INTEL_PT_TSC:
2365                        intel_pt_calc_tsc_timestamp(decoder);
2366                        break;
2367
2368                case INTEL_PT_TMA:
2369                        intel_pt_calc_tma(decoder);
2370                        break;
2371
2372                case INTEL_PT_CYC:
2373                        intel_pt_calc_cyc_timestamp(decoder);
2374                        break;
2375
2376                case INTEL_PT_CBR:
2377                        intel_pt_calc_cbr(decoder);
2378                        break;
2379
2380                case INTEL_PT_PIP:
2381                        decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
2382                        break;
2383
2384                case INTEL_PT_MODE_EXEC:
2385                        decoder->exec_mode = decoder->packet.payload;
2386                        break;
2387
2388                case INTEL_PT_MODE_TSX:
2389                        intel_pt_update_in_tx(decoder);
2390                        break;
2391
2392                case INTEL_PT_TRACESTOP:
2393                        decoder->pge = false;
2394                        decoder->continuous_period = false;
2395                        intel_pt_clear_tx_flags(decoder);
2396                        __fallthrough;
2397
2398                case INTEL_PT_TNT:
2399                        decoder->have_tma = false;
2400                        intel_pt_log("ERROR: Unexpected packet\n");
2401                        if (decoder->ip)
2402                                decoder->pkt_state = INTEL_PT_STATE_ERR4;
2403                        else
2404                                decoder->pkt_state = INTEL_PT_STATE_ERR3;
2405                        err = -ENOENT;
2406                        goto out;
2407
2408                case INTEL_PT_BAD: /* Does not happen */
2409                        err = intel_pt_bug(decoder);
2410                        goto out;
2411
2412                case INTEL_PT_OVF:
2413                        err = intel_pt_overflow(decoder);
2414                        goto out;
2415
2416                case INTEL_PT_PSBEND:
2417                        err = 0;
2418                        goto out;
2419
2420                case INTEL_PT_PSB:
2421                case INTEL_PT_VMCS:
2422                case INTEL_PT_MNT:
2423                case INTEL_PT_PAD:
2424                default:
2425                        break;
2426                }
2427        }
2428out:
2429        decoder->in_psb = false;
2430
2431        return err;
2432}
2433
2434static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
2435{
2436        int err;
2437
2438        while (1) {
2439                err = intel_pt_get_next_packet(decoder);
2440                if (err)
2441                        return err;
2442
2443                switch (decoder->packet.type) {
2444                case INTEL_PT_TIP_PGD:
2445                        decoder->continuous_period = false;
2446                        decoder->pge = false;
2447                        if (intel_pt_have_ip(decoder))
2448                                intel_pt_set_ip(decoder);
2449                        if (!decoder->ip)
2450                                break;
2451                        decoder->state.type |= INTEL_PT_TRACE_END;
2452                        return 0;
2453
2454                case INTEL_PT_TIP_PGE:
2455                        decoder->pge = true;
2456                        intel_pt_mtc_cyc_cnt_pge(decoder);
2457                        if (intel_pt_have_ip(decoder))
2458                                intel_pt_set_ip(decoder);
2459                        if (!decoder->ip)
2460                                break;
2461                        decoder->state.type |= INTEL_PT_TRACE_BEGIN;
2462                        return 0;
2463
2464                case INTEL_PT_TIP:
2465                        decoder->pge = true;
2466                        if (intel_pt_have_ip(decoder))
2467                                intel_pt_set_ip(decoder);
2468                        if (!decoder->ip)
2469                                break;
2470                        return 0;
2471
2472                case INTEL_PT_FUP:
2473                        if (intel_pt_have_ip(decoder))
2474                                intel_pt_set_ip(decoder);
2475                        if (decoder->ip)
2476                                return 0;
2477                        break;
2478
2479                case INTEL_PT_MTC:
2480                        intel_pt_calc_mtc_timestamp(decoder);
2481                        break;
2482
2483                case INTEL_PT_TSC:
2484                        intel_pt_calc_tsc_timestamp(decoder);
2485                        break;
2486
2487                case INTEL_PT_TMA:
2488                        intel_pt_calc_tma(decoder);
2489                        break;
2490
2491                case INTEL_PT_CYC:
2492                        intel_pt_calc_cyc_timestamp(decoder);
2493                        break;
2494
2495                case INTEL_PT_CBR:
2496                        intel_pt_calc_cbr(decoder);
2497                        break;
2498
2499                case INTEL_PT_PIP:
2500                        decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
2501                        break;
2502
2503                case INTEL_PT_MODE_EXEC:
2504                        decoder->exec_mode = decoder->packet.payload;
2505                        break;
2506
2507                case INTEL_PT_MODE_TSX:
2508                        intel_pt_update_in_tx(decoder);
2509                        break;
2510
2511                case INTEL_PT_OVF:
2512                        return intel_pt_overflow(decoder);
2513
2514                case INTEL_PT_BAD: /* Does not happen */
2515                        return intel_pt_bug(decoder);
2516
2517                case INTEL_PT_TRACESTOP:
2518                        decoder->pge = false;
2519                        decoder->continuous_period = false;
2520                        intel_pt_clear_tx_flags(decoder);
2521                        decoder->have_tma = false;
2522                        break;
2523
2524                case INTEL_PT_PSB:
2525                        decoder->last_ip = 0;
2526                        decoder->have_last_ip = true;
2527                        intel_pt_clear_stack(&decoder->stack);
2528                        err = intel_pt_walk_psb(decoder);
2529                        if (err)
2530                                return err;
2531                        if (decoder->ip) {
2532                                /* Do not have a sample */
2533                                decoder->state.type = 0;
2534                                return 0;
2535                        }
2536                        break;
2537
2538                case INTEL_PT_TNT:
2539                case INTEL_PT_PSBEND:
2540                case INTEL_PT_VMCS:
2541                case INTEL_PT_MNT:
2542                case INTEL_PT_PAD:
2543                case INTEL_PT_PTWRITE:
2544                case INTEL_PT_PTWRITE_IP:
2545                case INTEL_PT_EXSTOP:
2546                case INTEL_PT_EXSTOP_IP:
2547                case INTEL_PT_MWAIT:
2548                case INTEL_PT_PWRE:
2549                case INTEL_PT_PWRX:
2550                case INTEL_PT_BBP:
2551                case INTEL_PT_BIP:
2552                case INTEL_PT_BEP:
2553                case INTEL_PT_BEP_IP:
2554                default:
2555                        break;
2556                }
2557        }
2558}
2559
2560static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
2561{
2562        int err;
2563
2564        decoder->set_fup_tx_flags = false;
2565        decoder->set_fup_ptw = false;
2566        decoder->set_fup_mwait = false;
2567        decoder->set_fup_pwre = false;
2568        decoder->set_fup_exstop = false;
2569        decoder->set_fup_bep = false;
2570
2571        if (!decoder->branch_enable) {
2572                decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2573                decoder->overflow = false;
2574                decoder->state.type = 0; /* Do not have a sample */
2575                return 0;
2576        }
2577
2578        intel_pt_log("Scanning for full IP\n");
2579        err = intel_pt_walk_to_ip(decoder);
2580        if (err)
2581                return err;
2582
2583        /* In hop mode, resample to get the to_ip as an "instruction" sample */
2584        if (decoder->hop)
2585                decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
2586        else
2587                decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2588        decoder->overflow = false;
2589
2590        decoder->state.from_ip = 0;
2591        decoder->state.to_ip = decoder->ip;
2592        intel_pt_log_to("Setting IP", decoder->ip);
2593
2594        return 0;
2595}
2596
2597static int intel_pt_part_psb(struct intel_pt_decoder *decoder)
2598{
2599        const unsigned char *end = decoder->buf + decoder->len;
2600        size_t i;
2601
2602        for (i = INTEL_PT_PSB_LEN - 1; i; i--) {
2603                if (i > decoder->len)
2604                        continue;
2605                if (!memcmp(end - i, INTEL_PT_PSB_STR, i))
2606                        return i;
2607        }
2608        return 0;
2609}
2610
2611static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb)
2612{
2613        size_t rest_psb = INTEL_PT_PSB_LEN - part_psb;
2614        const char *psb = INTEL_PT_PSB_STR;
2615
2616        if (rest_psb > decoder->len ||
2617            memcmp(decoder->buf, psb + part_psb, rest_psb))
2618                return 0;
2619
2620        return rest_psb;
2621}
2622
2623static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder,
2624                                  int part_psb)
2625{
2626        int rest_psb, ret;
2627
2628        decoder->pos += decoder->len;
2629        decoder->len = 0;
2630
2631        ret = intel_pt_get_next_data(decoder, false);
2632        if (ret)
2633                return ret;
2634
2635        rest_psb = intel_pt_rest_psb(decoder, part_psb);
2636        if (!rest_psb)
2637                return 0;
2638
2639        decoder->pos -= part_psb;
2640        decoder->next_buf = decoder->buf + rest_psb;
2641        decoder->next_len = decoder->len - rest_psb;
2642        memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
2643        decoder->buf = decoder->temp_buf;
2644        decoder->len = INTEL_PT_PSB_LEN;
2645
2646        return 0;
2647}
2648
2649static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder)
2650{
2651        unsigned char *next;
2652        int ret;
2653
2654        intel_pt_log("Scanning for PSB\n");
2655        while (1) {
2656                if (!decoder->len) {
2657                        ret = intel_pt_get_next_data(decoder, false);
2658                        if (ret)
2659                                return ret;
2660                }
2661
2662                next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR,
2663                              INTEL_PT_PSB_LEN);
2664                if (!next) {
2665                        int part_psb;
2666
2667                        part_psb = intel_pt_part_psb(decoder);
2668                        if (part_psb) {
2669                                ret = intel_pt_get_split_psb(decoder, part_psb);
2670                                if (ret)
2671                                        return ret;
2672                        } else {
2673                                decoder->pos += decoder->len;
2674                                decoder->len = 0;
2675                        }
2676                        continue;
2677                }
2678
2679                decoder->pkt_step = next - decoder->buf;
2680                return intel_pt_get_next_packet(decoder);
2681        }
2682}
2683
2684static int intel_pt_sync(struct intel_pt_decoder *decoder)
2685{
2686        int err;
2687
2688        decoder->pge = false;
2689        decoder->continuous_period = false;
2690        decoder->have_last_ip = false;
2691        decoder->last_ip = 0;
2692        decoder->ip = 0;
2693        intel_pt_clear_stack(&decoder->stack);
2694
2695leap:
2696        err = intel_pt_scan_for_psb(decoder);
2697        if (err)
2698                return err;
2699
2700        decoder->have_last_ip = true;
2701        decoder->pkt_state = INTEL_PT_STATE_NO_IP;
2702
2703        err = intel_pt_walk_psb(decoder);
2704        if (err)
2705                return err;
2706
2707        if (decoder->ip) {
2708                decoder->state.type = 0; /* Do not have a sample */
2709                /*
2710                 * In hop mode, resample to get the PSB FUP ip as an
2711                 * "instruction" sample.
2712                 */
2713                if (decoder->hop)
2714                        decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
2715                else
2716                        decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
2717        } else if (decoder->leap) {
2718                /*
2719                 * In leap mode, only PSB+ is decoded, so keeping leaping to the
2720                 * next PSB until there is an ip.
2721                 */
2722                goto leap;
2723        } else {
2724                return intel_pt_sync_ip(decoder);
2725        }
2726
2727        return 0;
2728}
2729
2730static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
2731{
2732        uint64_t est = decoder->sample_insn_cnt << 1;
2733
2734        if (!decoder->cbr || !decoder->max_non_turbo_ratio)
2735                goto out;
2736
2737        est *= decoder->max_non_turbo_ratio;
2738        est /= decoder->cbr;
2739out:
2740        return decoder->sample_timestamp + est;
2741}
2742
2743const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
2744{
2745        int err;
2746
2747        do {
2748                decoder->state.type = INTEL_PT_BRANCH;
2749                decoder->state.flags = 0;
2750
2751                switch (decoder->pkt_state) {
2752                case INTEL_PT_STATE_NO_PSB:
2753                        err = intel_pt_sync(decoder);
2754                        break;
2755                case INTEL_PT_STATE_NO_IP:
2756                        decoder->have_last_ip = false;
2757                        decoder->last_ip = 0;
2758                        decoder->ip = 0;
2759                        __fallthrough;
2760                case INTEL_PT_STATE_ERR_RESYNC:
2761                        err = intel_pt_sync_ip(decoder);
2762                        break;
2763                case INTEL_PT_STATE_IN_SYNC:
2764                        err = intel_pt_walk_trace(decoder);
2765                        break;
2766                case INTEL_PT_STATE_TNT:
2767                case INTEL_PT_STATE_TNT_CONT:
2768                        err = intel_pt_walk_tnt(decoder);
2769                        if (err == -EAGAIN)
2770                                err = intel_pt_walk_trace(decoder);
2771                        break;
2772                case INTEL_PT_STATE_TIP:
2773                case INTEL_PT_STATE_TIP_PGD:
2774                        err = intel_pt_walk_tip(decoder);
2775                        break;
2776                case INTEL_PT_STATE_FUP:
2777                        err = intel_pt_walk_fup(decoder);
2778                        if (err == -EAGAIN)
2779                                err = intel_pt_walk_fup_tip(decoder);
2780                        break;
2781                case INTEL_PT_STATE_FUP_NO_TIP:
2782                        err = intel_pt_walk_fup(decoder);
2783                        if (err == -EAGAIN)
2784                                err = intel_pt_walk_trace(decoder);
2785                        break;
2786                case INTEL_PT_STATE_RESAMPLE:
2787                        err = intel_pt_resample(decoder);
2788                        break;
2789                default:
2790                        err = intel_pt_bug(decoder);
2791                        break;
2792                }
2793        } while (err == -ENOLINK);
2794
2795        if (err) {
2796                decoder->state.err = intel_pt_ext_err(err);
2797                decoder->state.from_ip = decoder->ip;
2798                intel_pt_update_sample_time(decoder);
2799                decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
2800        } else {
2801                decoder->state.err = 0;
2802                if (decoder->cbr != decoder->cbr_seen) {
2803                        decoder->cbr_seen = decoder->cbr;
2804                        if (!decoder->state.type) {
2805                                decoder->state.from_ip = decoder->ip;
2806                                decoder->state.to_ip = 0;
2807                        }
2808                        decoder->state.type |= INTEL_PT_CBR_CHG;
2809                        decoder->state.cbr_payload = decoder->cbr_payload;
2810                        decoder->state.cbr = decoder->cbr;
2811                }
2812                if (intel_pt_sample_time(decoder->pkt_state)) {
2813                        intel_pt_update_sample_time(decoder);
2814                        if (decoder->sample_cyc)
2815                                decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
2816                }
2817        }
2818
2819        decoder->state.timestamp = decoder->sample_timestamp;
2820        decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
2821        decoder->state.cr3 = decoder->cr3;
2822        decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
2823        decoder->state.tot_cyc_cnt = decoder->sample_tot_cyc_cnt;
2824
2825        return &decoder->state;
2826}
2827
2828/**
2829 * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet.
2830 * @buf: pointer to buffer pointer
2831 * @len: size of buffer
2832 *
2833 * Updates the buffer pointer to point to the start of the next PSB packet if
2834 * there is one, otherwise the buffer pointer is unchanged.  If @buf is updated,
2835 * @len is adjusted accordingly.
2836 *
2837 * Return: %true if a PSB packet is found, %false otherwise.
2838 */
2839static bool intel_pt_next_psb(unsigned char **buf, size_t *len)
2840{
2841        unsigned char *next;
2842
2843        next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
2844        if (next) {
2845                *len -= next - *buf;
2846                *buf = next;
2847                return true;
2848        }
2849        return false;
2850}
2851
2852/**
2853 * intel_pt_step_psb - move buffer pointer to the start of the following PSB
2854 *                     packet.
2855 * @buf: pointer to buffer pointer
2856 * @len: size of buffer
2857 *
2858 * Updates the buffer pointer to point to the start of the following PSB packet
2859 * (skipping the PSB at @buf itself) if there is one, otherwise the buffer
2860 * pointer is unchanged.  If @buf is updated, @len is adjusted accordingly.
2861 *
2862 * Return: %true if a PSB packet is found, %false otherwise.
2863 */
2864static bool intel_pt_step_psb(unsigned char **buf, size_t *len)
2865{
2866        unsigned char *next;
2867
2868        if (!*len)
2869                return false;
2870
2871        next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
2872        if (next) {
2873                *len -= next - *buf;
2874                *buf = next;
2875                return true;
2876        }
2877        return false;
2878}
2879
2880/**
2881 * intel_pt_last_psb - find the last PSB packet in a buffer.
2882 * @buf: buffer
2883 * @len: size of buffer
2884 *
2885 * This function finds the last PSB in a buffer.
2886 *
2887 * Return: A pointer to the last PSB in @buf if found, %NULL otherwise.
2888 */
2889static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
2890{
2891        const char *n = INTEL_PT_PSB_STR;
2892        unsigned char *p;
2893        size_t k;
2894
2895        if (len < INTEL_PT_PSB_LEN)
2896                return NULL;
2897
2898        k = len - INTEL_PT_PSB_LEN + 1;
2899        while (1) {
2900                p = memrchr(buf, n[0], k);
2901                if (!p)
2902                        return NULL;
2903                if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1))
2904                        return p;
2905                k = p - buf;
2906                if (!k)
2907                        return NULL;
2908        }
2909}
2910
2911/**
2912 * intel_pt_next_tsc - find and return next TSC.
2913 * @buf: buffer
2914 * @len: size of buffer
2915 * @tsc: TSC value returned
2916 * @rem: returns remaining size when TSC is found
2917 *
2918 * Find a TSC packet in @buf and return the TSC value.  This function assumes
2919 * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a
2920 * PSBEND packet is found.
2921 *
2922 * Return: %true if TSC is found, false otherwise.
2923 */
2924static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc,
2925                              size_t *rem)
2926{
2927        enum intel_pt_pkt_ctx ctx = INTEL_PT_NO_CTX;
2928        struct intel_pt_pkt packet;
2929        int ret;
2930
2931        while (len) {
2932                ret = intel_pt_get_packet(buf, len, &packet, &ctx);
2933                if (ret <= 0)
2934                        return false;
2935                if (packet.type == INTEL_PT_TSC) {
2936                        *tsc = packet.payload;
2937                        *rem = len;
2938                        return true;
2939                }
2940                if (packet.type == INTEL_PT_PSBEND)
2941                        return false;
2942                buf += ret;
2943                len -= ret;
2944        }
2945        return false;
2946}
2947
2948/**
2949 * intel_pt_tsc_cmp - compare 7-byte TSCs.
2950 * @tsc1: first TSC to compare
2951 * @tsc2: second TSC to compare
2952 *
2953 * This function compares 7-byte TSC values allowing for the possibility that
2954 * TSC wrapped around.  Generally it is not possible to know if TSC has wrapped
2955 * around so for that purpose this function assumes the absolute difference is
2956 * less than half the maximum difference.
2957 *
2958 * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is
2959 * after @tsc2.
2960 */
2961static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2)
2962{
2963        const uint64_t halfway = (1ULL << 55);
2964
2965        if (tsc1 == tsc2)
2966                return 0;
2967
2968        if (tsc1 < tsc2) {
2969                if (tsc2 - tsc1 < halfway)
2970                        return -1;
2971                else
2972                        return 1;
2973        } else {
2974                if (tsc1 - tsc2 < halfway)
2975                        return 1;
2976                else
2977                        return -1;
2978        }
2979}
2980
2981#define MAX_PADDING (PERF_AUXTRACE_RECORD_ALIGNMENT - 1)
2982
2983/**
2984 * adj_for_padding - adjust overlap to account for padding.
2985 * @buf_b: second buffer
2986 * @buf_a: first buffer
2987 * @len_a: size of first buffer
2988 *
2989 * @buf_a might have up to 7 bytes of padding appended. Adjust the overlap
2990 * accordingly.
2991 *
2992 * Return: A pointer into @buf_b from where non-overlapped data starts
2993 */
2994static unsigned char *adj_for_padding(unsigned char *buf_b,
2995                                      unsigned char *buf_a, size_t len_a)
2996{
2997        unsigned char *p = buf_b - MAX_PADDING;
2998        unsigned char *q = buf_a + len_a - MAX_PADDING;
2999        int i;
3000
3001        for (i = MAX_PADDING; i; i--, p++, q++) {
3002                if (*p != *q)
3003                        break;
3004        }
3005
3006        return p;
3007}
3008
3009/**
3010 * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data
3011 *                             using TSC.
3012 * @buf_a: first buffer
3013 * @len_a: size of first buffer
3014 * @buf_b: second buffer
3015 * @len_b: size of second buffer
3016 * @consecutive: returns true if there is data in buf_b that is consecutive
3017 *               to buf_a
3018 *
3019 * If the trace contains TSC we can look at the last TSC of @buf_a and the
3020 * first TSC of @buf_b in order to determine if the buffers overlap, and then
3021 * walk forward in @buf_b until a later TSC is found.  A precondition is that
3022 * @buf_a and @buf_b are positioned at a PSB.
3023 *
3024 * Return: A pointer into @buf_b from where non-overlapped data starts, or
3025 * @buf_b + @len_b if there is no non-overlapped data.
3026 */
3027static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,
3028                                                size_t len_a,
3029                                                unsigned char *buf_b,
3030                                                size_t len_b, bool *consecutive)
3031{
3032        uint64_t tsc_a, tsc_b;
3033        unsigned char *p;
3034        size_t len, rem_a, rem_b;
3035
3036        p = intel_pt_last_psb(buf_a, len_a);
3037        if (!p)
3038                return buf_b; /* No PSB in buf_a => no overlap */
3039
3040        len = len_a - (p - buf_a);
3041        if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a)) {
3042                /* The last PSB+ in buf_a is incomplete, so go back one more */
3043                len_a -= len;
3044                p = intel_pt_last_psb(buf_a, len_a);
3045                if (!p)
3046                        return buf_b; /* No full PSB+ => assume no overlap */
3047                len = len_a - (p - buf_a);
3048                if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a))
3049                        return buf_b; /* No TSC in buf_a => assume no overlap */
3050        }
3051
3052        while (1) {
3053                /* Ignore PSB+ with no TSC */
3054                if (intel_pt_next_tsc(buf_b, len_b, &tsc_b, &rem_b)) {
3055                        int cmp = intel_pt_tsc_cmp(tsc_a, tsc_b);
3056
3057                        /* Same TSC, so buffers are consecutive */
3058                        if (!cmp && rem_b >= rem_a) {
3059                                unsigned char *start;
3060
3061                                *consecutive = true;
3062                                start = buf_b + len_b - (rem_b - rem_a);
3063                                return adj_for_padding(start, buf_a, len_a);
3064                        }
3065                        if (cmp < 0)
3066                                return buf_b; /* tsc_a < tsc_b => no overlap */
3067                }
3068
3069                if (!intel_pt_step_psb(&buf_b, &len_b))
3070                        return buf_b + len_b; /* No PSB in buf_b => no data */
3071        }
3072}
3073
3074/**
3075 * intel_pt_find_overlap - determine start of non-overlapped trace data.
3076 * @buf_a: first buffer
3077 * @len_a: size of first buffer
3078 * @buf_b: second buffer
3079 * @len_b: size of second buffer
3080 * @have_tsc: can use TSC packets to detect overlap
3081 * @consecutive: returns true if there is data in buf_b that is consecutive
3082 *               to buf_a
3083 *
3084 * When trace samples or snapshots are recorded there is the possibility that
3085 * the data overlaps.  Note that, for the purposes of decoding, data is only
3086 * useful if it begins with a PSB packet.
3087 *
3088 * Return: A pointer into @buf_b from where non-overlapped data starts, or
3089 * @buf_b + @len_b if there is no non-overlapped data.
3090 */
3091unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a,
3092                                     unsigned char *buf_b, size_t len_b,
3093                                     bool have_tsc, bool *consecutive)
3094{
3095        unsigned char *found;
3096
3097        /* Buffer 'b' must start at PSB so throw away everything before that */
3098        if (!intel_pt_next_psb(&buf_b, &len_b))
3099                return buf_b + len_b; /* No PSB */
3100
3101        if (!intel_pt_next_psb(&buf_a, &len_a))
3102                return buf_b; /* No overlap */
3103
3104        if (have_tsc) {
3105                found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b,
3106                                                  consecutive);
3107                if (found)
3108                        return found;
3109        }
3110
3111        /*
3112         * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes,
3113         * we can ignore the first part of buffer 'a'.
3114         */
3115        while (len_b < len_a) {
3116                if (!intel_pt_step_psb(&buf_a, &len_a))
3117                        return buf_b; /* No overlap */
3118        }
3119
3120        /* Now len_b >= len_a */
3121        while (1) {
3122                /* Potential overlap so check the bytes */
3123                found = memmem(buf_a, len_a, buf_b, len_a);
3124                if (found) {
3125                        *consecutive = true;
3126                        return adj_for_padding(buf_b + len_a, buf_a, len_a);
3127                }
3128
3129                /* Try again at next PSB in buffer 'a' */
3130                if (!intel_pt_step_psb(&buf_a, &len_a))
3131                        return buf_b; /* No overlap */
3132        }
3133}
3134
3135/**
3136 * struct fast_forward_data - data used by intel_pt_ff_cb().
3137 * @timestamp: timestamp to fast forward towards
3138 * @buf_timestamp: buffer timestamp of last buffer with trace data earlier than
3139 *                 the fast forward timestamp.
3140 */
3141struct fast_forward_data {
3142        uint64_t timestamp;
3143        uint64_t buf_timestamp;
3144};
3145
3146/**
3147 * intel_pt_ff_cb - fast forward lookahead callback.
3148 * @buffer: Intel PT trace buffer
3149 * @data: opaque pointer to fast forward data (struct fast_forward_data)
3150 *
3151 * Determine if @buffer trace is past the fast forward timestamp.
3152 *
3153 * Return: 1 (stop lookahead) if @buffer trace is past the fast forward
3154 *         timestamp, and 0 otherwise.
3155 */
3156static int intel_pt_ff_cb(struct intel_pt_buffer *buffer, void *data)
3157{
3158        struct fast_forward_data *d = data;
3159        unsigned char *buf;
3160        uint64_t tsc;
3161        size_t rem;
3162        size_t len;
3163
3164        buf = (unsigned char *)buffer->buf;
3165        len = buffer->len;
3166
3167        if (!intel_pt_next_psb(&buf, &len) ||
3168            !intel_pt_next_tsc(buf, len, &tsc, &rem))
3169                return 0;
3170
3171        tsc = intel_pt_8b_tsc(tsc, buffer->ref_timestamp);
3172
3173        intel_pt_log("Buffer 1st timestamp " x64_fmt " ref timestamp " x64_fmt "\n",
3174                     tsc, buffer->ref_timestamp);
3175
3176        /*
3177         * If the buffer contains a timestamp earlier that the fast forward
3178         * timestamp, then record it, else stop.
3179         */
3180        if (tsc < d->timestamp)
3181                d->buf_timestamp = buffer->ref_timestamp;
3182        else
3183                return 1;
3184
3185        return 0;
3186}
3187
3188/**
3189 * intel_pt_fast_forward - reposition decoder forwards.
3190 * @decoder: Intel PT decoder
3191 * @timestamp: timestamp to fast forward towards
3192 *
3193 * Reposition decoder at the last PSB with a timestamp earlier than @timestamp.
3194 *
3195 * Return: 0 on success or negative error code on failure.
3196 */
3197int intel_pt_fast_forward(struct intel_pt_decoder *decoder, uint64_t timestamp)
3198{
3199        struct fast_forward_data d = { .timestamp = timestamp };
3200        unsigned char *buf;
3201        size_t len;
3202        int err;
3203
3204        intel_pt_log("Fast forward towards timestamp " x64_fmt "\n", timestamp);
3205
3206        /* Find buffer timestamp of buffer to fast forward to */
3207        err = decoder->lookahead(decoder->data, intel_pt_ff_cb, &d);
3208        if (err < 0)
3209                return err;
3210
3211        /* Walk to buffer with same buffer timestamp */
3212        if (d.buf_timestamp) {
3213                do {
3214                        decoder->pos += decoder->len;
3215                        decoder->len = 0;
3216                        err = intel_pt_get_next_data(decoder, true);
3217                        /* -ENOLINK means non-consecutive trace */
3218                        if (err && err != -ENOLINK)
3219                                return err;
3220                } while (decoder->buf_timestamp != d.buf_timestamp);
3221        }
3222
3223        if (!decoder->buf)
3224                return 0;
3225
3226        buf = (unsigned char *)decoder->buf;
3227        len = decoder->len;
3228
3229        if (!intel_pt_next_psb(&buf, &len))
3230                return 0;
3231
3232        /*
3233         * Walk PSBs while the PSB timestamp is less than the fast forward
3234         * timestamp.
3235         */
3236        do {
3237                uint64_t tsc;
3238                size_t rem;
3239
3240                if (!intel_pt_next_tsc(buf, len, &tsc, &rem))
3241                        break;
3242                tsc = intel_pt_8b_tsc(tsc, decoder->buf_timestamp);
3243                /*
3244                 * A TSC packet can slip past MTC packets but, after fast
3245                 * forward, decoding starts at the TSC timestamp. That means
3246                 * the timestamps may not be exactly the same as the timestamps
3247                 * that would have been decoded without fast forward.
3248                 */
3249                if (tsc < timestamp) {
3250                        intel_pt_log("Fast forward to next PSB timestamp " x64_fmt "\n", tsc);
3251                        decoder->pos += decoder->len - len;
3252                        decoder->buf = buf;
3253                        decoder->len = len;
3254                        intel_pt_reposition(decoder);
3255                } else {
3256                        break;
3257                }
3258        } while (intel_pt_step_psb(&buf, &len));
3259
3260        return 0;
3261}
3262