text: /*
   * intel_pt_decoder.c: Intel Processor Trace support
   * Copyright (c) 2013-2014, Intel Corporation.
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms and conditions of the GNU General Public License,
   * version 2, as published by the Free Software Foundation.
   *
   * This program is distributed in the hope it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
   * more details.
   *
   */
  
  #ifndef _GNU_SOURCE
  #define _GNU_SOURCE
  #endif
  #include <stdlib.h>
  #include <stdbool.h>
  #include <string.h>
  #include <errno.h>
  #include <stdint.h>
  #include <inttypes.h>
  #include <linux/compiler.h>
  
  #include "../cache.h"
  #include "../util.h"
  
  #include "intel-pt-insn-decoder.h"
  #include "intel-pt-pkt-decoder.h"
  #include "intel-pt-decoder.h"
  #include "intel-pt-log.h"
  
  #define INTEL_PT_BLK_SIZE 1024
  
  #define BIT63 (((uint64_t)1 << 63))
  
  #define INTEL_PT_RETURN 1
  
  /* Maximum number of loops with no packets consumed i.e. stuck in a loop */
  #define INTEL_PT_MAX_LOOPS 10000
  
  struct intel_pt_blk {
  	struct intel_pt_blk *prev;
  	uint64_t ip[INTEL_PT_BLK_SIZE];
  };
  
  struct intel_pt_stack {
  	struct intel_pt_blk *blk;
  	struct intel_pt_blk *spare;
  	int pos;
  };
  
  enum intel_pt_pkt_state {
  	INTEL_PT_STATE_NO_PSB,
  	INTEL_PT_STATE_NO_IP,
  	INTEL_PT_STATE_ERR_RESYNC,
  	INTEL_PT_STATE_IN_SYNC,
  	INTEL_PT_STATE_TNT,
  	INTEL_PT_STATE_TIP,
  	INTEL_PT_STATE_TIP_PGD,
  	INTEL_PT_STATE_FUP,
  	INTEL_PT_STATE_FUP_NO_TIP,
  };
  
  static inline bool intel_pt_sample_time(enum intel_pt_pkt_state pkt_state)
  {
  	switch (pkt_state) {
  	case INTEL_PT_STATE_NO_PSB:
  	case INTEL_PT_STATE_NO_IP:
  	case INTEL_PT_STATE_ERR_RESYNC:
  	case INTEL_PT_STATE_IN_SYNC:
  	case INTEL_PT_STATE_TNT:
  		return true;
  	case INTEL_PT_STATE_TIP:
  	case INTEL_PT_STATE_TIP_PGD:
  	case INTEL_PT_STATE_FUP:
  	case INTEL_PT_STATE_FUP_NO_TIP:
  		return false;
  	default:
  		return true;
  	};
  }
  
  #ifdef INTEL_PT_STRICT
  #define INTEL_PT_STATE_ERR1	INTEL_PT_STATE_NO_PSB
  #define INTEL_PT_STATE_ERR2	INTEL_PT_STATE_NO_PSB
  #define INTEL_PT_STATE_ERR3	INTEL_PT_STATE_NO_PSB
  #define INTEL_PT_STATE_ERR4	INTEL_PT_STATE_NO_PSB
  #else
  #define INTEL_PT_STATE_ERR1	(decoder->pkt_state)
  #define INTEL_PT_STATE_ERR2	INTEL_PT_STATE_NO_IP
  #define INTEL_PT_STATE_ERR3	INTEL_PT_STATE_ERR_RESYNC
  #define INTEL_PT_STATE_ERR4	INTEL_PT_STATE_IN_SYNC
  #endif
  
  struct intel_pt_decoder {
  	int (*get_trace)(struct intel_pt_buffer *buffer, void *data);
  	int (*walk_insn)(struct intel_pt_insn *intel_pt_insn,
  			 uint64_t *insn_cnt_ptr, uint64_t *ip, uint64_t to_ip,
  			 uint64_t max_insn_cnt, void *data);
  	bool (*pgd_ip)(uint64_t ip, void *data);
  	void *data;
  	struct intel_pt_state state;
  	const unsigned char *buf;
  	size_t len;
  	bool return_compression;
  	bool branch_enable;
  	bool mtc_insn;
  	bool pge;
  	bool have_tma;
  	bool have_cyc;
  	bool fixup_last_mtc;
  	bool have_last_ip;
  	enum intel_pt_param_flags flags;
  	uint64_t pos;
  	uint64_t last_ip;
  	uint64_t ip;
  	uint64_t cr3;
  	uint64_t timestamp;
  	uint64_t tsc_timestamp;
  	uint64_t ref_timestamp;
  	uint64_t sample_timestamp;
  	uint64_t ret_addr;
  	uint64_t ctc_timestamp;
  	uint64_t ctc_delta;
  	uint64_t cycle_cnt;
  	uint64_t cyc_ref_timestamp;
  	uint32_t last_mtc;
  	uint32_t tsc_ctc_ratio_n;
  	uint32_t tsc_ctc_ratio_d;
  	uint32_t tsc_ctc_mult;
  	uint32_t tsc_slip;
  	uint32_t ctc_rem_mask;
  	int mtc_shift;
  	struct intel_pt_stack stack;
  	enum intel_pt_pkt_state pkt_state;
  	struct intel_pt_pkt packet;
  	struct intel_pt_pkt tnt;
  	int pkt_step;
  	int pkt_len;
  	int last_packet_type;
  	unsigned int cbr;
  	unsigned int cbr_seen;
  	unsigned int max_non_turbo_ratio;
  	double max_non_turbo_ratio_fp;
  	double cbr_cyc_to_tsc;
  	double calc_cyc_to_tsc;
  	bool have_calc_cyc_to_tsc;
  	int exec_mode;
  	unsigned int insn_bytes;
  	uint64_t period;
  	enum intel_pt_period_type period_type;
  	uint64_t tot_insn_cnt;
  	uint64_t period_insn_cnt;
  	uint64_t period_mask;
  	uint64_t period_ticks;
  	uint64_t last_masked_timestamp;
  	bool continuous_period;
  	bool overflow;
  	bool set_fup_tx_flags;
  	bool set_fup_ptw;
  	bool set_fup_mwait;
  	bool set_fup_pwre;
  	bool set_fup_exstop;
  	unsigned int fup_tx_flags;
  	unsigned int tx_flags;
  	uint64_t fup_ptw_payload;
  	uint64_t fup_mwait_payload;
  	uint64_t fup_pwre_payload;
  	uint64_t cbr_payload;
  	uint64_t timestamp_insn_cnt;
  	uint64_t sample_insn_cnt;
  	uint64_t stuck_ip;
  	int no_progress;
  	int stuck_ip_prd;
  	int stuck_ip_cnt;
  	const unsigned char *next_buf;
  	size_t next_len;
  	unsigned char temp_buf[INTEL_PT_PKT_MAX_SZ];
  };
  
  static uint64_t intel_pt_lower_power_of_2(uint64_t x)
  {
  	int i;
  
  	for (i = 0; x != 1; i++)
  		x >>= 1;
  
  	return x << i;
  }
  
  static void intel_pt_setup_period(struct intel_pt_decoder *decoder)
  {
  	if (decoder->period_type == INTEL_PT_PERIOD_TICKS) {
  		uint64_t period;
  
  		period = intel_pt_lower_power_of_2(decoder->period);
  		decoder->period_mask  = ~(period - 1);
  		decoder->period_ticks = period;
  	}
  }
  
  static uint64_t multdiv(uint64_t t, uint32_t n, uint32_t d)
  {
  	if (!d)
  		return 0;
  	return (t / d) * n + ((t % d) * n) / d;
  }
  
  struct intel_pt_decoder *intel_pt_decoder_new(struct intel_pt_params *params)
  {
  	struct intel_pt_decoder *decoder;
  
  	if (!params->get_trace || !params->walk_insn)
  		return NULL;
  
  	decoder = zalloc(sizeof(struct intel_pt_decoder));
  	if (!decoder)
  		return NULL;
  
  	decoder->get_trace          = params->get_trace;
  	decoder->walk_insn          = params->walk_insn;
  	decoder->pgd_ip             = params->pgd_ip;
  	decoder->data               = params->data;
  	decoder->return_compression = params->return_compression;
  	decoder->branch_enable      = params->branch_enable;
  
  	decoder->flags              = params->flags;
  
  	decoder->period             = params->period;
  	decoder->period_type        = params->period_type;
  
  	decoder->max_non_turbo_ratio    = params->max_non_turbo_ratio;
  	decoder->max_non_turbo_ratio_fp = params->max_non_turbo_ratio;
  
  	intel_pt_setup_period(decoder);
  
  	decoder->mtc_shift = params->mtc_period;
  	decoder->ctc_rem_mask = (1 << decoder->mtc_shift) - 1;
  
  	decoder->tsc_ctc_ratio_n = params->tsc_ctc_ratio_n;
  	decoder->tsc_ctc_ratio_d = params->tsc_ctc_ratio_d;
  
  	if (!decoder->tsc_ctc_ratio_n)
  		decoder->tsc_ctc_ratio_d = 0;
  
  	if (decoder->tsc_ctc_ratio_d) {
  		if (!(decoder->tsc_ctc_ratio_n % decoder->tsc_ctc_ratio_d))
  			decoder->tsc_ctc_mult = decoder->tsc_ctc_ratio_n /
  						decoder->tsc_ctc_ratio_d;
  
  		/*
  		 * Allow for timestamps appearing to backwards because a TSC
  		 * packet has slipped past a MTC packet, so allow 2 MTC ticks
  		 * or ...
  		 */
  		decoder->tsc_slip = multdiv(2 << decoder->mtc_shift,
  					decoder->tsc_ctc_ratio_n,
  					decoder->tsc_ctc_ratio_d);
  	}
  	/* ... or 0x100 paranoia */
  	if (decoder->tsc_slip < 0x100)
  		decoder->tsc_slip = 0x100;
  
  	intel_pt_log("timestamp: mtc_shift %u\n", decoder->mtc_shift);
  	intel_pt_log("timestamp: tsc_ctc_ratio_n %u\n", decoder->tsc_ctc_ratio_n);
  	intel_pt_log("timestamp: tsc_ctc_ratio_d %u\n", decoder->tsc_ctc_ratio_d);
  	intel_pt_log("timestamp: tsc_ctc_mult %u\n", decoder->tsc_ctc_mult);
  	intel_pt_log("timestamp: tsc_slip %#x\n", decoder->tsc_slip);
  
  	return decoder;
  }
  
  static void intel_pt_pop_blk(struct intel_pt_stack *stack)
  {
  	struct intel_pt_blk *blk = stack->blk;
  
  	stack->blk = blk->prev;
  	if (!stack->spare)
  		stack->spare = blk;
  	else
  		free(blk);
  }
  
  static uint64_t intel_pt_pop(struct intel_pt_stack *stack)
  {
  	if (!stack->pos) {
  		if (!stack->blk)
  			return 0;
  		intel_pt_pop_blk(stack);
  		if (!stack->blk)
  			return 0;
  		stack->pos = INTEL_PT_BLK_SIZE;
  	}
  	return stack->blk->ip[--stack->pos];
  }
  
  static int intel_pt_alloc_blk(struct intel_pt_stack *stack)
  {
  	struct intel_pt_blk *blk;
  
  	if (stack->spare) {
  		blk = stack->spare;
  		stack->spare = NULL;
  	} else {
  		blk = malloc(sizeof(struct intel_pt_blk));
  		if (!blk)
  			return -ENOMEM;
  	}
  
  	blk->prev = stack->blk;
  	stack->blk = blk;
  	stack->pos = 0;
  	return 0;
  }
  
  static int intel_pt_push(struct intel_pt_stack *stack, uint64_t ip)
  {
  	int err;
  
  	if (!stack->blk || stack->pos == INTEL_PT_BLK_SIZE) {
  		err = intel_pt_alloc_blk(stack);
  		if (err)
  			return err;
  	}
  
  	stack->blk->ip[stack->pos++] = ip;
  	return 0;
  }
  
  static void intel_pt_clear_stack(struct intel_pt_stack *stack)
  {
  	while (stack->blk)
  		intel_pt_pop_blk(stack);
  	stack->pos = 0;
  }
  
  static void intel_pt_free_stack(struct intel_pt_stack *stack)
  {
  	intel_pt_clear_stack(stack);
  	zfree(&stack->blk);
  	zfree(&stack->spare);
  }
  
  void intel_pt_decoder_free(struct intel_pt_decoder *decoder)
  {
  	intel_pt_free_stack(&decoder->stack);
  	free(decoder);
  }
  
  static int intel_pt_ext_err(int code)
  {
  	switch (code) {
  	case -ENOMEM:
  		return INTEL_PT_ERR_NOMEM;
  	case -ENOSYS:
  		return INTEL_PT_ERR_INTERN;
  	case -EBADMSG:
  		return INTEL_PT_ERR_BADPKT;
  	case -ENODATA:
  		return INTEL_PT_ERR_NODATA;
  	case -EILSEQ:
  		return INTEL_PT_ERR_NOINSN;
  	case -ENOENT:
  		return INTEL_PT_ERR_MISMAT;
  	case -EOVERFLOW:
  		return INTEL_PT_ERR_OVR;
  	case -ENOSPC:
  		return INTEL_PT_ERR_LOST;
  	case -ELOOP:
  		return INTEL_PT_ERR_NELOOP;
  	default:
  		return INTEL_PT_ERR_UNK;
  	}
  }
  
  static const char *intel_pt_err_msgs[] = {
  	[INTEL_PT_ERR_NOMEM]  = "Memory allocation failed",
  	[INTEL_PT_ERR_INTERN] = "Internal error",
  	[INTEL_PT_ERR_BADPKT] = "Bad packet",
  	[INTEL_PT_ERR_NODATA] = "No more data",
  	[INTEL_PT_ERR_NOINSN] = "Failed to get instruction",
  	[INTEL_PT_ERR_MISMAT] = "Trace doesn't match instruction",
  	[INTEL_PT_ERR_OVR]    = "Overflow packet",
  	[INTEL_PT_ERR_LOST]   = "Lost trace data",
  	[INTEL_PT_ERR_UNK]    = "Unknown error!",
  	[INTEL_PT_ERR_NELOOP] = "Never-ending loop",
  };
  
  int intel_pt__strerror(int code, char *buf, size_t buflen)
  {
  	if (code < 1 || code >= INTEL_PT_ERR_MAX)
  		code = INTEL_PT_ERR_UNK;
  	strlcpy(buf, intel_pt_err_msgs[code], buflen);
  	return 0;
  }
  
  static uint64_t intel_pt_calc_ip(const struct intel_pt_pkt *packet,
  				 uint64_t last_ip)
  {
  	uint64_t ip;
  
  	switch (packet->count) {
  	case 1:
  		ip = (last_ip & (uint64_t)0xffffffffffff0000ULL) |
  		     packet->payload;
  		break;
  	case 2:
  		ip = (last_ip & (uint64_t)0xffffffff00000000ULL) |
  		     packet->payload;
  		break;
  	case 3:
  		ip = packet->payload;
  		/* Sign-extend 6-byte ip */
  		if (ip & (uint64_t)0x800000000000ULL)
  			ip |= (uint64_t)0xffff000000000000ULL;
  		break;
  	case 4:
  		ip = (last_ip & (uint64_t)0xffff000000000000ULL) |
  		     packet->payload;
  		break;
  	case 6:
  		ip = packet->payload;
  		break;
  	default:
  		return 0;
  	}
  
  	return ip;
  }
  
  static inline void intel_pt_set_last_ip(struct intel_pt_decoder *decoder)
  {
  	decoder->last_ip = intel_pt_calc_ip(&decoder->packet, decoder->last_ip);
  	decoder->have_last_ip = true;
  }
  
  static inline void intel_pt_set_ip(struct intel_pt_decoder *decoder)
  {
  	intel_pt_set_last_ip(decoder);
  	decoder->ip = decoder->last_ip;
  }
  
  static void intel_pt_decoder_log_packet(struct intel_pt_decoder *decoder)
  {
  	intel_pt_log_packet(&decoder->packet, decoder->pkt_len, decoder->pos,
  			    decoder->buf);
  }
  
  static int intel_pt_bug(struct intel_pt_decoder *decoder)
  {
  	intel_pt_log("ERROR: Internal error\n");
  	decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
  	return -ENOSYS;
  }
  
  static inline void intel_pt_clear_tx_flags(struct intel_pt_decoder *decoder)
  {
  	decoder->tx_flags = 0;
  }
  
  static inline void intel_pt_update_in_tx(struct intel_pt_decoder *decoder)
  {
  	decoder->tx_flags = decoder->packet.payload & INTEL_PT_IN_TX;
  }
  
  static int intel_pt_bad_packet(struct intel_pt_decoder *decoder)
  {
  	intel_pt_clear_tx_flags(decoder);
  	decoder->have_tma = false;
  	decoder->pkt_len = 1;
  	decoder->pkt_step = 1;
  	intel_pt_decoder_log_packet(decoder);
  	if (decoder->pkt_state != INTEL_PT_STATE_NO_PSB) {
  		intel_pt_log("ERROR: Bad packet\n");
  		decoder->pkt_state = INTEL_PT_STATE_ERR1;
  	}
  	return -EBADMSG;
  }
  
  static int intel_pt_get_data(struct intel_pt_decoder *decoder)
  {
  	struct intel_pt_buffer buffer = { .buf = 0, };
  	int ret;
  
  	decoder->pkt_step = 0;
  
  	intel_pt_log("Getting more data\n");
  	ret = decoder->get_trace(&buffer, decoder->data);
  	if (ret)
  		return ret;
  	decoder->buf = buffer.buf;
  	decoder->len = buffer.len;
  	if (!decoder->len) {
  		intel_pt_log("No more data\n");
  		return -ENODATA;
  	}
  	if (!buffer.consecutive) {
  		decoder->ip = 0;
  		decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
  		decoder->ref_timestamp = buffer.ref_timestamp;
  		decoder->timestamp = 0;
  		decoder->have_tma = false;
  		decoder->state.trace_nr = buffer.trace_nr;
  		intel_pt_log("Reference timestamp 0x%" PRIx64 "\n",
  			     decoder->ref_timestamp);
  		return -ENOLINK;
  	}
  
  	return 0;
  }
  
  static int intel_pt_get_next_data(struct intel_pt_decoder *decoder)
  {
  	if (!decoder->next_buf)
  		return intel_pt_get_data(decoder);
  
  	decoder->buf = decoder->next_buf;
  	decoder->len = decoder->next_len;
  	decoder->next_buf = 0;
  	decoder->next_len = 0;
  	return 0;
  }
  
  static int intel_pt_get_split_packet(struct intel_pt_decoder *decoder)
  {
  	unsigned char *buf = decoder->temp_buf;
  	size_t old_len, len, n;
  	int ret;
  
  	old_len = decoder->len;
  	len = decoder->len;
  	memcpy(buf, decoder->buf, len);
  
  	ret = intel_pt_get_data(decoder);
  	if (ret) {
  		decoder->pos += old_len;
  		return ret < 0 ? ret : -EINVAL;
  	}
  
  	n = INTEL_PT_PKT_MAX_SZ - len;
  	if (n > decoder->len)
  		n = decoder->len;
  	memcpy(buf + len, decoder->buf, n);
  	len += n;
  
  	ret = intel_pt_get_packet(buf, len, &decoder->packet);
  	if (ret < (int)old_len) {
  		decoder->next_buf = decoder->buf;
  		decoder->next_len = decoder->len;
  		decoder->buf = buf;
  		decoder->len = old_len;
  		return intel_pt_bad_packet(decoder);
  	}
  
  	decoder->next_buf = decoder->buf + (ret - old_len);
  	decoder->next_len = decoder->len - (ret - old_len);
  
  	decoder->buf = buf;
  	decoder->len = ret;
  
  	return ret;
  }
  
  struct intel_pt_pkt_info {
  	struct intel_pt_decoder	  *decoder;
  	struct intel_pt_pkt       packet;
  	uint64_t                  pos;
  	int                       pkt_len;
  	int                       last_packet_type;
  	void                      *data;
  };
  
  typedef int (*intel_pt_pkt_cb_t)(struct intel_pt_pkt_info *pkt_info);
  
  /* Lookahead packets in current buffer */
  static int intel_pt_pkt_lookahead(struct intel_pt_decoder *decoder,
  				  intel_pt_pkt_cb_t cb, void *data)
  {
  	struct intel_pt_pkt_info pkt_info;
  	const unsigned char *buf = decoder->buf;
  	size_t len = decoder->len;
  	int ret;
  
  	pkt_info.decoder          = decoder;
  	pkt_info.pos              = decoder->pos;
  	pkt_info.pkt_len          = decoder->pkt_step;
  	pkt_info.last_packet_type = decoder->last_packet_type;
  	pkt_info.data             = data;
  
  	while (1) {
  		do {
  			pkt_info.pos += pkt_info.pkt_len;
  			buf          += pkt_info.pkt_len;
  			len          -= pkt_info.pkt_len;
  
  			if (!len)
  				return INTEL_PT_NEED_MORE_BYTES;
  
  			ret = intel_pt_get_packet(buf, len, &pkt_info.packet);
  			if (!ret)
  				return INTEL_PT_NEED_MORE_BYTES;
  			if (ret < 0)
  				return ret;
  
  			pkt_info.pkt_len = ret;
  		} while (pkt_info.packet.type == INTEL_PT_PAD);
  
  		ret = cb(&pkt_info);
  		if (ret)
  			return 0;
  
  		pkt_info.last_packet_type = pkt_info.packet.type;
  	}
  }
  
  struct intel_pt_calc_cyc_to_tsc_info {
  	uint64_t        cycle_cnt;
  	unsigned int    cbr;
  	uint32_t        last_mtc;
  	uint64_t        ctc_timestamp;
  	uint64_t        ctc_delta;
  	uint64_t        tsc_timestamp;
  	uint64_t        timestamp;
  	bool            have_tma;
  	bool            fixup_last_mtc;
  	bool            from_mtc;
  	double          cbr_cyc_to_tsc;
  };
  
  /*
   * MTC provides a 8-bit slice of CTC but the TMA packet only provides the lower
   * 16 bits of CTC. If mtc_shift > 8 then some of the MTC bits are not in the CTC
   * provided by the TMA packet. Fix-up the last_mtc calculated from the TMA
   * packet by copying the missing bits from the current MTC assuming the least
   * difference between the two, and that the current MTC comes after last_mtc.
   */
  static void intel_pt_fixup_last_mtc(uint32_t mtc, int mtc_shift,
  				    uint32_t *last_mtc)
  {
  	uint32_t first_missing_bit = 1U << (16 - mtc_shift);
  	uint32_t mask = ~(first_missing_bit - 1);
  
  	*last_mtc |= mtc & mask;
  	if (*last_mtc >= mtc) {
  		*last_mtc -= first_missing_bit;
  		*last_mtc &= 0xff;
  	}
  }
  
  static int intel_pt_calc_cyc_cb(struct intel_pt_pkt_info *pkt_info)
  {
  	struct intel_pt_decoder *decoder = pkt_info->decoder;
  	struct intel_pt_calc_cyc_to_tsc_info *data = pkt_info->data;
  	uint64_t timestamp;
  	double cyc_to_tsc;
  	unsigned int cbr;
  	uint32_t mtc, mtc_delta, ctc, fc, ctc_rem;
  
  	switch (pkt_info->packet.type) {
  	case INTEL_PT_TNT:
  	case INTEL_PT_TIP_PGE:
  	case INTEL_PT_TIP:
  	case INTEL_PT_FUP:
  	case INTEL_PT_PSB:
  	case INTEL_PT_PIP:
  	case INTEL_PT_MODE_EXEC:
  	case INTEL_PT_MODE_TSX:
  	case INTEL_PT_PSBEND:
  	case INTEL_PT_PAD:
  	case INTEL_PT_VMCS:
  	case INTEL_PT_MNT:
  	case INTEL_PT_PTWRITE:
  	case INTEL_PT_PTWRITE_IP:
  		return 0;
  
  	case INTEL_PT_MTC:
  		if (!data->have_tma)
  			return 0;
  
  		mtc = pkt_info->packet.payload;
  		if (decoder->mtc_shift > 8 && data->fixup_last_mtc) {
  			data->fixup_last_mtc = false;
  			intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
  						&data->last_mtc);
  		}
  		if (mtc > data->last_mtc)
  			mtc_delta = mtc - data->last_mtc;
  		else
  			mtc_delta = mtc + 256 - data->last_mtc;
  		data->ctc_delta += mtc_delta << decoder->mtc_shift;
  		data->last_mtc = mtc;
  
  		if (decoder->tsc_ctc_mult) {
  			timestamp = data->ctc_timestamp +
  				data->ctc_delta * decoder->tsc_ctc_mult;
  		} else {
  			timestamp = data->ctc_timestamp +
  				multdiv(data->ctc_delta,
  					decoder->tsc_ctc_ratio_n,
  					decoder->tsc_ctc_ratio_d);
  		}
  
  		if (timestamp < data->timestamp)
  			return 1;
  
  		if (pkt_info->last_packet_type != INTEL_PT_CYC) {
  			data->timestamp = timestamp;
  			return 0;
  		}
  
  		break;
  
  	case INTEL_PT_TSC:
  		/*
  		 * For now, do not support using TSC packets - refer
  		 * intel_pt_calc_cyc_to_tsc().
  		 */
  		if (data->from_mtc)
  			return 1;
  		timestamp = pkt_info->packet.payload |
  			    (data->timestamp & (0xffULL << 56));
  		if (data->from_mtc && timestamp < data->timestamp &&
  		    data->timestamp - timestamp < decoder->tsc_slip)
  			return 1;
  		if (timestamp < data->timestamp)
  			timestamp += (1ULL << 56);
  		if (pkt_info->last_packet_type != INTEL_PT_CYC) {
  			if (data->from_mtc)
  				return 1;
  			data->tsc_timestamp = timestamp;
  			data->timestamp = timestamp;
  			return 0;
  		}
  		break;
  
  	case INTEL_PT_TMA:
  		if (data->from_mtc)
  			return 1;
  
  		if (!decoder->tsc_ctc_ratio_d)
  			return 0;
  
  		ctc = pkt_info->packet.payload;
  		fc = pkt_info->packet.count;
  		ctc_rem = ctc & decoder->ctc_rem_mask;
  
  		data->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
  
  		data->ctc_timestamp = data->tsc_timestamp - fc;
  		if (decoder->tsc_ctc_mult) {
  			data->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
  		} else {
  			data->ctc_timestamp -=
  				multdiv(ctc_rem, decoder->tsc_ctc_ratio_n,
  					decoder->tsc_ctc_ratio_d);
  		}
  
  		data->ctc_delta = 0;
  		data->have_tma = true;
  		data->fixup_last_mtc = true;
  
  		return 0;
  
  	case INTEL_PT_CYC:
  		data->cycle_cnt += pkt_info->packet.payload;
  		return 0;
  
  	case INTEL_PT_CBR:
  		cbr = pkt_info->packet.payload;
  		if (data->cbr && data->cbr != cbr)
  			return 1;
  		data->cbr = cbr;
  		data->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
  		return 0;
  
  	case INTEL_PT_TIP_PGD:
  	case INTEL_PT_TRACESTOP:
  	case INTEL_PT_EXSTOP:
  	case INTEL_PT_EXSTOP_IP:
  	case INTEL_PT_MWAIT:
  	case INTEL_PT_PWRE:
  	case INTEL_PT_PWRX:
  	case INTEL_PT_OVF:
  	case INTEL_PT_BAD: /* Does not happen */
  	default:
  		return 1;
  	}
  
  	if (!data->cbr && decoder->cbr) {
  		data->cbr = decoder->cbr;
  		data->cbr_cyc_to_tsc = decoder->cbr_cyc_to_tsc;
  	}
  
  	if (!data->cycle_cnt)
  		return 1;
  
  	cyc_to_tsc = (double)(timestamp - decoder->timestamp) / data->cycle_cnt;
  
  	if (data->cbr && cyc_to_tsc > data->cbr_cyc_to_tsc &&
  	    cyc_to_tsc / data->cbr_cyc_to_tsc > 1.25) {
  		intel_pt_log("Timestamp: calculated %g TSC ticks per cycle too big (c.f. CBR-based value %g), pos " x64_fmt "\n",
  			     cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
  		return 1;
  	}
  
  	decoder->calc_cyc_to_tsc = cyc_to_tsc;
  	decoder->have_calc_cyc_to_tsc = true;
  
  	if (data->cbr) {
  		intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. CBR-based value %g, pos " x64_fmt "\n",
  			     cyc_to_tsc, data->cbr_cyc_to_tsc, pkt_info->pos);
  	} else {
  		intel_pt_log("Timestamp: calculated %g TSC ticks per cycle c.f. unknown CBR-based value, pos " x64_fmt "\n",
  			     cyc_to_tsc, pkt_info->pos);
  	}
  
  	return 1;
  }
  
  static void intel_pt_calc_cyc_to_tsc(struct intel_pt_decoder *decoder,
  				     bool from_mtc)
  {
  	struct intel_pt_calc_cyc_to_tsc_info data = {
  		.cycle_cnt      = 0,
  		.cbr            = 0,
  		.last_mtc       = decoder->last_mtc,
  		.ctc_timestamp  = decoder->ctc_timestamp,
  		.ctc_delta      = decoder->ctc_delta,
  		.tsc_timestamp  = decoder->tsc_timestamp,
  		.timestamp      = decoder->timestamp,
  		.have_tma       = decoder->have_tma,
  		.fixup_last_mtc = decoder->fixup_last_mtc,
  		.from_mtc       = from_mtc,
  		.cbr_cyc_to_tsc = 0,
  	};
  
  	/*
  	 * For now, do not support using TSC packets for at least the reasons:
  	 * 1) timing might have stopped
  	 * 2) TSC packets within PSB+ can slip against CYC packets
  	 */
  	if (!from_mtc)
  		return;
  
  	intel_pt_pkt_lookahead(decoder, intel_pt_calc_cyc_cb, &data);
  }
  
  static int intel_pt_get_next_packet(struct intel_pt_decoder *decoder)
  {
  	int ret;
  
  	decoder->last_packet_type = decoder->packet.type;
  
  	do {
  		decoder->pos += decoder->pkt_step;
  		decoder->buf += decoder->pkt_step;
  		decoder->len -= decoder->pkt_step;
  
  		if (!decoder->len) {
  			ret = intel_pt_get_next_data(decoder);
  			if (ret)
  				return ret;
  		}
  
  		ret = intel_pt_get_packet(decoder->buf, decoder->len,
  					  &decoder->packet);
  		if (ret == INTEL_PT_NEED_MORE_BYTES &&
  		    decoder->len < INTEL_PT_PKT_MAX_SZ && !decoder->next_buf) {
  			ret = intel_pt_get_split_packet(decoder);
  			if (ret < 0)
  				return ret;
  		}
  		if (ret <= 0)
  			return intel_pt_bad_packet(decoder);
  
  		decoder->pkt_len = ret;
  		decoder->pkt_step = ret;
  		intel_pt_decoder_log_packet(decoder);
  	} while (decoder->packet.type == INTEL_PT_PAD);
  
  	return 0;
  }
  
  static uint64_t intel_pt_next_period(struct intel_pt_decoder *decoder)
  {
  	uint64_t timestamp, masked_timestamp;
  
  	timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
  	masked_timestamp = timestamp & decoder->period_mask;
  	if (decoder->continuous_period) {
  		if (masked_timestamp != decoder->last_masked_timestamp)
  			return 1;
  	} else {
  		timestamp += 1;
  		masked_timestamp = timestamp & decoder->period_mask;
  		if (masked_timestamp != decoder->last_masked_timestamp) {
  			decoder->last_masked_timestamp = masked_timestamp;
  			decoder->continuous_period = true;
  		}
  	}
  	return decoder->period_ticks - (timestamp - masked_timestamp);
  }
  
  static uint64_t intel_pt_next_sample(struct intel_pt_decoder *decoder)
  {
  	switch (decoder->period_type) {
  	case INTEL_PT_PERIOD_INSTRUCTIONS:
  		return decoder->period - decoder->period_insn_cnt;
  	case INTEL_PT_PERIOD_TICKS:
  		return intel_pt_next_period(decoder);
  	case INTEL_PT_PERIOD_NONE:
  	case INTEL_PT_PERIOD_MTC:
  	default:
  		return 0;
  	}
  }
  
  static void intel_pt_sample_insn(struct intel_pt_decoder *decoder)
  {
  	uint64_t timestamp, masked_timestamp;
  
  	switch (decoder->period_type) {
  	case INTEL_PT_PERIOD_INSTRUCTIONS:
  		decoder->period_insn_cnt = 0;
  		break;
  	case INTEL_PT_PERIOD_TICKS:
  		timestamp = decoder->timestamp + decoder->timestamp_insn_cnt;
  		masked_timestamp = timestamp & decoder->period_mask;
  		decoder->last_masked_timestamp = masked_timestamp;
  		break;
  	case INTEL_PT_PERIOD_NONE:
  	case INTEL_PT_PERIOD_MTC:
  	default:
  		break;
  	}
  
  	decoder->state.type |= INTEL_PT_INSTRUCTION;
  }
  
  static int intel_pt_walk_insn(struct intel_pt_decoder *decoder,
  			      struct intel_pt_insn *intel_pt_insn, uint64_t ip)
  {
  	uint64_t max_insn_cnt, insn_cnt = 0;
  	int err;
  
  	if (!decoder->mtc_insn)
  		decoder->mtc_insn = true;
  
  	max_insn_cnt = intel_pt_next_sample(decoder);
  
  	err = decoder->walk_insn(intel_pt_insn, &insn_cnt, &decoder->ip, ip,
  				 max_insn_cnt, decoder->data);
  
  	decoder->tot_insn_cnt += insn_cnt;
  	decoder->timestamp_insn_cnt += insn_cnt;
  	decoder->sample_insn_cnt += insn_cnt;
  	decoder->period_insn_cnt += insn_cnt;
  
  	if (err) {
  		decoder->no_progress = 0;
  		decoder->pkt_state = INTEL_PT_STATE_ERR2;
  		intel_pt_log_at("ERROR: Failed to get instruction",
  				decoder->ip);
  		if (err == -ENOENT)
  			return -ENOLINK;
  		return -EILSEQ;
  	}
  
  	if (ip && decoder->ip == ip) {
  		err = -EAGAIN;
  		goto out;
  	}
  
  	if (max_insn_cnt && insn_cnt >= max_insn_cnt)
  		intel_pt_sample_insn(decoder);
  
  	if (intel_pt_insn->branch == INTEL_PT_BR_NO_BRANCH) {
  		decoder->state.type = INTEL_PT_INSTRUCTION;
  		decoder->state.from_ip = decoder->ip;
  		decoder->state.to_ip = 0;
  		decoder->ip += intel_pt_insn->length;
  		err = INTEL_PT_RETURN;
  		goto out;
  	}
  
  	if (intel_pt_insn->op == INTEL_PT_OP_CALL) {
  		/* Zero-length calls are excluded */
  		if (intel_pt_insn->branch != INTEL_PT_BR_UNCONDITIONAL ||
  		    intel_pt_insn->rel) {
  			err = intel_pt_push(&decoder->stack, decoder->ip +
  					    intel_pt_insn->length);
  			if (err)
  				goto out;
  		}
  	} else if (intel_pt_insn->op == INTEL_PT_OP_RET) {
  		decoder->ret_addr = intel_pt_pop(&decoder->stack);
  	}
  
  	if (intel_pt_insn->branch == INTEL_PT_BR_UNCONDITIONAL) {
  		int cnt = decoder->no_progress++;
  
  		decoder->state.from_ip = decoder->ip;
  		decoder->ip += intel_pt_insn->length +
  				intel_pt_insn->rel;
  		decoder->state.to_ip = decoder->ip;
  		err = INTEL_PT_RETURN;
  
  		/*
  		 * Check for being stuck in a loop.  This can happen if a
  		 * decoder error results in the decoder erroneously setting the
  		 * ip to an address that is itself in an infinite loop that
  		 * consumes no packets.  When that happens, there must be an
  		 * unconditional branch.
  		 */
  		if (cnt) {
  			if (cnt == 1) {
  				decoder->stuck_ip = decoder->state.to_ip;
  				decoder->stuck_ip_prd = 1;
  				decoder->stuck_ip_cnt = 1;
  			} else if (cnt > INTEL_PT_MAX_LOOPS ||
  				   decoder->state.to_ip == decoder->stuck_ip) {
  				intel_pt_log_at("ERROR: Never-ending loop",
  						decoder->state.to_ip);
  				decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
  				err = -ELOOP;
  				goto out;
  			} else if (!--decoder->stuck_ip_cnt) {
  				decoder->stuck_ip_prd += 1;
  				decoder->stuck_ip_cnt = decoder->stuck_ip_prd;
  				decoder->stuck_ip = decoder->state.to_ip;
  			}
  		}
  		goto out_no_progress;
  	}
  out:
  	decoder->no_progress = 0;
  out_no_progress:
  	decoder->state.insn_op = intel_pt_insn->op;
  	decoder->state.insn_len = intel_pt_insn->length;
  	memcpy(decoder->state.insn, intel_pt_insn->buf,
  	       INTEL_PT_INSN_BUF_SZ);
  
  	if (decoder->tx_flags & INTEL_PT_IN_TX)
  		decoder->state.flags |= INTEL_PT_IN_TX;
  
  	return err;
  }
  
  static bool intel_pt_fup_event(struct intel_pt_decoder *decoder)
  {
  	bool ret = false;
  
  	if (decoder->set_fup_tx_flags) {
  		decoder->set_fup_tx_flags = false;
  		decoder->tx_flags = decoder->fup_tx_flags;
  		decoder->state.type = INTEL_PT_TRANSACTION;
  		decoder->state.from_ip = decoder->ip;
  		decoder->state.to_ip = 0;
  		decoder->state.flags = decoder->fup_tx_flags;
  		return true;
  	}
  	if (decoder->set_fup_ptw) {
  		decoder->set_fup_ptw = false;
  		decoder->state.type = INTEL_PT_PTW;
  		decoder->state.flags |= INTEL_PT_FUP_IP;
  		decoder->state.from_ip = decoder->ip;
  		decoder->state.to_ip = 0;
  		decoder->state.ptw_payload = decoder->fup_ptw_payload;
  		return true;
  	}
  	if (decoder->set_fup_mwait) {
  		decoder->set_fup_mwait = false;
  		decoder->state.type = INTEL_PT_MWAIT_OP;
  		decoder->state.from_ip = decoder->ip;
  		decoder->state.to_ip = 0;
  		decoder->state.mwait_payload = decoder->fup_mwait_payload;
  		ret = true;
  	}
  	if (decoder->set_fup_pwre) {
  		decoder->set_fup_pwre = false;
  		decoder->state.type |= INTEL_PT_PWR_ENTRY;
  		decoder->state.type &= ~INTEL_PT_BRANCH;
  		decoder->state.from_ip = decoder->ip;
  		decoder->state.to_ip = 0;
  		decoder->state.pwre_payload = decoder->fup_pwre_payload;
  		ret = true;
  	}
  	if (decoder->set_fup_exstop) {
  		decoder->set_fup_exstop = false;
  		decoder->state.type |= INTEL_PT_EX_STOP;
  		decoder->state.type &= ~INTEL_PT_BRANCH;
  		decoder->state.flags |= INTEL_PT_FUP_IP;
  		decoder->state.from_ip = decoder->ip;
  		decoder->state.to_ip = 0;
  		ret = true;
  	}
  	return ret;
  }
  
  static inline bool intel_pt_fup_with_nlip(struct intel_pt_decoder *decoder,
  					  struct intel_pt_insn *intel_pt_insn,
  					  uint64_t ip, int err)
  {
  	return decoder->flags & INTEL_PT_FUP_WITH_NLIP && !err &&
  	       intel_pt_insn->branch == INTEL_PT_BR_INDIRECT &&
  	       ip == decoder->ip + intel_pt_insn->length;
  }
  
  static int intel_pt_walk_fup(struct intel_pt_decoder *decoder)
  {
  	struct intel_pt_insn intel_pt_insn;
  	uint64_t ip;
  	int err;
  
  	ip = decoder->last_ip;
  
  	while (1) {
  		err = intel_pt_walk_insn(decoder, &intel_pt_insn, ip);
  		if (err == INTEL_PT_RETURN)
  			return 0;
  		if (err == -EAGAIN ||
  		    intel_pt_fup_with_nlip(decoder, &intel_pt_insn, ip, err)) {
  			if (intel_pt_fup_event(decoder))
  				return 0;
  			return -EAGAIN;
  		}
  		decoder->set_fup_tx_flags = false;
  		if (err)
  			return err;
  
  		if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
  			intel_pt_log_at("ERROR: Unexpected indirect branch",
  					decoder->ip);
  			decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
  			return -ENOENT;
  		}
  
  		if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
  			intel_pt_log_at("ERROR: Unexpected conditional branch",
  					decoder->ip);
  			decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
  			return -ENOENT;
  		}
  
  		intel_pt_bug(decoder);
  	}
  }
  
  static int intel_pt_walk_tip(struct intel_pt_decoder *decoder)
  {
  	struct intel_pt_insn intel_pt_insn;
  	int err;
  
  	err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
  	if (err == INTEL_PT_RETURN &&
  	    decoder->pgd_ip &&
  	    decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
  	    (decoder->state.type & INTEL_PT_BRANCH) &&
  	    decoder->pgd_ip(decoder->state.to_ip, decoder->data)) {
  		/* Unconditional branch leaving filter region */
  		decoder->no_progress = 0;
  		decoder->pge = false;
  		decoder->continuous_period = false;
  		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
  		decoder->state.to_ip = 0;
  		return 0;
  	}
  	if (err == INTEL_PT_RETURN)
  		return 0;
  	if (err)
  		return err;
  
  	if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
  		if (decoder->pkt_state == INTEL_PT_STATE_TIP_PGD) {
  			decoder->pge = false;
  			decoder->continuous_period = false;
  			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
  			decoder->state.from_ip = decoder->ip;
  			decoder->state.to_ip = 0;
  			if (decoder->packet.count != 0)
  				decoder->ip = decoder->last_ip;
  		} else {
  			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
  			decoder->state.from_ip = decoder->ip;
  			if (decoder->packet.count == 0) {
  				decoder->state.to_ip = 0;
  			} else {
  				decoder->state.to_ip = decoder->last_ip;
  				decoder->ip = decoder->last_ip;
  			}
  		}
  		return 0;
  	}
  
  	if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
  		uint64_t to_ip = decoder->ip + intel_pt_insn.length +
  				 intel_pt_insn.rel;
  
  		if (decoder->pgd_ip &&
  		    decoder->pkt_state == INTEL_PT_STATE_TIP_PGD &&
  		    decoder->pgd_ip(to_ip, decoder->data)) {
  			/* Conditional branch leaving filter region */
  			decoder->pge = false;
  			decoder->continuous_period = false;
  			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
  			decoder->ip = to_ip;
  			decoder->state.from_ip = decoder->ip;
  			decoder->state.to_ip = 0;
  			return 0;
  		}
  		intel_pt_log_at("ERROR: Conditional branch when expecting indirect branch",
  				decoder->ip);
  		decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
  		return -ENOENT;
  	}
  
  	return intel_pt_bug(decoder);
  }
  
  static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
  {
  	struct intel_pt_insn intel_pt_insn;
  	int err;
  
  	while (1) {
  		err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
  		if (err == INTEL_PT_RETURN)
  			return 0;
  		if (err)
  			return err;
  
  		if (intel_pt_insn.op == INTEL_PT_OP_RET) {
  			if (!decoder->return_compression) {
  				intel_pt_log_at("ERROR: RET when expecting conditional branch",
  						decoder->ip);
  				decoder->pkt_state = INTEL_PT_STATE_ERR3;
  				return -ENOENT;
  			}
  			if (!decoder->ret_addr) {
  				intel_pt_log_at("ERROR: Bad RET compression (stack empty)",
  						decoder->ip);
  				decoder->pkt_state = INTEL_PT_STATE_ERR3;
  				return -ENOENT;
  			}
  			if (!(decoder->tnt.payload & BIT63)) {
  				intel_pt_log_at("ERROR: Bad RET compression (TNT=N)",
  						decoder->ip);
  				decoder->pkt_state = INTEL_PT_STATE_ERR3;
  				return -ENOENT;
  			}
  			decoder->tnt.count -= 1;
  			if (!decoder->tnt.count)
  				decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
  			decoder->tnt.payload <<= 1;
  			decoder->state.from_ip = decoder->ip;
  			decoder->ip = decoder->ret_addr;
  			decoder->state.to_ip = decoder->ip;
  			return 0;
  		}
  
  		if (intel_pt_insn.branch == INTEL_PT_BR_INDIRECT) {
  			/* Handle deferred TIPs */
  			err = intel_pt_get_next_packet(decoder);
  			if (err)
  				return err;
  			if (decoder->packet.type != INTEL_PT_TIP ||
  			    decoder->packet.count == 0) {
  				intel_pt_log_at("ERROR: Missing deferred TIP for indirect branch",
  						decoder->ip);
  				decoder->pkt_state = INTEL_PT_STATE_ERR3;
  				decoder->pkt_step = 0;
  				return -ENOENT;
  			}
  			intel_pt_set_last_ip(decoder);
  			decoder->state.from_ip = decoder->ip;
  			decoder->state.to_ip = decoder->last_ip;
  			decoder->ip = decoder->last_ip;
  			return 0;
  		}
  
  		if (intel_pt_insn.branch == INTEL_PT_BR_CONDITIONAL) {
  			decoder->tnt.count -= 1;
  			if (!decoder->tnt.count)
  				decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
  			if (decoder->tnt.payload & BIT63) {
  				decoder->tnt.payload <<= 1;
  				decoder->state.from_ip = decoder->ip;
  				decoder->ip += intel_pt_insn.length +
  					       intel_pt_insn.rel;
  				decoder->state.to_ip = decoder->ip;
  				return 0;
  			}
  			/* Instruction sample for a non-taken branch */
  			if (decoder->state.type & INTEL_PT_INSTRUCTION) {
  				decoder->tnt.payload <<= 1;
  				decoder->state.type = INTEL_PT_INSTRUCTION;
  				decoder->state.from_ip = decoder->ip;
  				decoder->state.to_ip = 0;
  				decoder->ip += intel_pt_insn.length;
  				return 0;
  			}
  			decoder->ip += intel_pt_insn.length;
  			if (!decoder->tnt.count)
  				return -EAGAIN;
  			decoder->tnt.payload <<= 1;
  			continue;
  		}
  
  		return intel_pt_bug(decoder);
  	}
  }
  
  static int intel_pt_mode_tsx(struct intel_pt_decoder *decoder, bool *no_tip)
  {
  	unsigned int fup_tx_flags;
  	int err;
  
  	fup_tx_flags = decoder->packet.payload &
  		       (INTEL_PT_IN_TX | INTEL_PT_ABORT_TX);
  	err = intel_pt_get_next_packet(decoder);
  	if (err)
  		return err;
  	if (decoder->packet.type == INTEL_PT_FUP) {
  		decoder->fup_tx_flags = fup_tx_flags;
  		decoder->set_fup_tx_flags = true;
  		if (!(decoder->fup_tx_flags & INTEL_PT_ABORT_TX))
  			*no_tip = true;
  	} else {
  		intel_pt_log_at("ERROR: Missing FUP after MODE.TSX",
  				decoder->pos);
  		intel_pt_update_in_tx(decoder);
  	}
  	return 0;
  }
  
  static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
  {
  	uint64_t timestamp;
  
  	decoder->have_tma = false;
  
  	if (decoder->ref_timestamp) {
  		timestamp = decoder->packet.payload |
  			    (decoder->ref_timestamp & (0xffULL << 56));
  		if (timestamp < decoder->ref_timestamp) {
  			if (decoder->ref_timestamp - timestamp > (1ULL << 55))
  				timestamp += (1ULL << 56);
  		} else {
  			if (timestamp - decoder->ref_timestamp > (1ULL << 55))
  				timestamp -= (1ULL << 56);
  		}
  		decoder->tsc_timestamp = timestamp;
  		decoder->timestamp = timestamp;
  		decoder->ref_timestamp = 0;
  		decoder->timestamp_insn_cnt = 0;
  	} else if (decoder->timestamp) {
  		timestamp = decoder->packet.payload |
  			    (decoder->timestamp & (0xffULL << 56));
  		decoder->tsc_timestamp = timestamp;
  		if (timestamp < decoder->timestamp &&
  		    decoder->timestamp - timestamp < decoder->tsc_slip) {
  			intel_pt_log_to("Suppressing backwards timestamp",
  					timestamp);
  			timestamp = decoder->timestamp;
  		}
  		if (timestamp < decoder->timestamp) {
  			intel_pt_log_to("Wraparound timestamp", timestamp);
  			timestamp += (1ULL << 56);
  			decoder->tsc_timestamp = timestamp;
  		}
  		decoder->timestamp = timestamp;
  		decoder->timestamp_insn_cnt = 0;
  	}
  
  	if (decoder->last_packet_type == INTEL_PT_CYC) {
  		decoder->cyc_ref_timestamp = decoder->timestamp;
  		decoder->cycle_cnt = 0;
  		decoder->have_calc_cyc_to_tsc = false;
  		intel_pt_calc_cyc_to_tsc(decoder, false);
  	}
  
  	intel_pt_log_to("Setting timestamp", decoder->timestamp);
  }
  
  static int intel_pt_overflow(struct intel_pt_decoder *decoder)
  {
  	intel_pt_log("ERROR: Buffer overflow\n");
  	intel_pt_clear_tx_flags(decoder);
  	decoder->cbr = 0;
  	decoder->timestamp_insn_cnt = 0;
  	decoder->pkt_state = INTEL_PT_STATE_ERR_RESYNC;
  	decoder->overflow = true;
  	return -EOVERFLOW;
  }
  
  static void intel_pt_calc_tma(struct intel_pt_decoder *decoder)
  {
  	uint32_t ctc = decoder->packet.payload;
  	uint32_t fc = decoder->packet.count;
  	uint32_t ctc_rem = ctc & decoder->ctc_rem_mask;
  
  	if (!decoder->tsc_ctc_ratio_d)
  		return;
  
  	decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
  	decoder->ctc_timestamp = decoder->tsc_timestamp - fc;
  	if (decoder->tsc_ctc_mult) {
  		decoder->ctc_timestamp -= ctc_rem * decoder->tsc_ctc_mult;
  	} else {
  		decoder->ctc_timestamp -= multdiv(ctc_rem,
  						  decoder->tsc_ctc_ratio_n,
  						  decoder->tsc_ctc_ratio_d);
  	}
  	decoder->ctc_delta = 0;
  	decoder->have_tma = true;
  	decoder->fixup_last_mtc = true;
  	intel_pt_log("CTC timestamp " x64_fmt " last MTC %#x  CTC rem %#x\n",
  		     decoder->ctc_timestamp, decoder->last_mtc, ctc_rem);
  }
  
  static void intel_pt_calc_mtc_timestamp(struct intel_pt_decoder *decoder)
  {
  	uint64_t timestamp;
  	uint32_t mtc, mtc_delta;
  
  	if (!decoder->have_tma)
  		return;
  
  	mtc = decoder->packet.payload;
  
  	if (decoder->mtc_shift > 8 && decoder->fixup_last_mtc) {
  		decoder->fixup_last_mtc = false;
  		intel_pt_fixup_last_mtc(mtc, decoder->mtc_shift,
  					&decoder->last_mtc);
  	}
  
  	if (mtc > decoder->last_mtc)
  		mtc_delta = mtc - decoder->last_mtc;
  	else
  		mtc_delta = mtc + 256 - decoder->last_mtc;
  
  	decoder->ctc_delta += mtc_delta << decoder->mtc_shift;
  
  	if (decoder->tsc_ctc_mult) {
  		timestamp = decoder->ctc_timestamp +
  			    decoder->ctc_delta * decoder->tsc_ctc_mult;
  	} else {
  		timestamp = decoder->ctc_timestamp +
  			    multdiv(decoder->ctc_delta,
  				    decoder->tsc_ctc_ratio_n,
  				    decoder->tsc_ctc_ratio_d);
  	}
  
  	if (timestamp < decoder->timestamp)
  		intel_pt_log("Suppressing MTC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
  			     timestamp, decoder->timestamp);
  	else
  		decoder->timestamp = timestamp;
  
  	decoder->timestamp_insn_cnt = 0;
  	decoder->last_mtc = mtc;
  
  	if (decoder->last_packet_type == INTEL_PT_CYC) {
  		decoder->cyc_ref_timestamp = decoder->timestamp;
  		decoder->cycle_cnt = 0;
  		decoder->have_calc_cyc_to_tsc = false;
  		intel_pt_calc_cyc_to_tsc(decoder, true);
  	}
  }
  
  static void intel_pt_calc_cbr(struct intel_pt_decoder *decoder)
  {
  	unsigned int cbr = decoder->packet.payload & 0xff;
  
  	decoder->cbr_payload = decoder->packet.payload;
  
  	if (decoder->cbr == cbr)
  		return;
  
  	decoder->cbr = cbr;
  	decoder->cbr_cyc_to_tsc = decoder->max_non_turbo_ratio_fp / cbr;
  }
  
  static void intel_pt_calc_cyc_timestamp(struct intel_pt_decoder *decoder)
  {
  	uint64_t timestamp = decoder->cyc_ref_timestamp;
  
  	decoder->have_cyc = true;
  
  	decoder->cycle_cnt += decoder->packet.payload;
  
  	if (!decoder->cyc_ref_timestamp)
  		return;
  
  	if (decoder->have_calc_cyc_to_tsc)
  		timestamp += decoder->cycle_cnt * decoder->calc_cyc_to_tsc;
  	else if (decoder->cbr)
  		timestamp += decoder->cycle_cnt * decoder->cbr_cyc_to_tsc;
  	else
  		return;
  
  	if (timestamp < decoder->timestamp)
  		intel_pt_log("Suppressing CYC timestamp " x64_fmt " less than current timestamp " x64_fmt "\n",
  			     timestamp, decoder->timestamp);
  	else
  		decoder->timestamp = timestamp;
  
  	decoder->timestamp_insn_cnt = 0;
  }
  
  /* Walk PSB+ packets when already in sync. */
  static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
  {
  	int err;
  
  	while (1) {
  		err = intel_pt_get_next_packet(decoder);
  		if (err)
  			return err;
  
  		switch (decoder->packet.type) {
  		case INTEL_PT_PSBEND:
  			return 0;
  
  		case INTEL_PT_TIP_PGD:
  		case INTEL_PT_TIP_PGE:
  		case INTEL_PT_TIP:
  		case INTEL_PT_TNT:
  		case INTEL_PT_TRACESTOP:
  		case INTEL_PT_BAD:
  		case INTEL_PT_PSB:
  		case INTEL_PT_PTWRITE:
  		case INTEL_PT_PTWRITE_IP:
  		case INTEL_PT_EXSTOP:
  		case INTEL_PT_EXSTOP_IP:
  		case INTEL_PT_MWAIT:
  		case INTEL_PT_PWRE:
  		case INTEL_PT_PWRX:
  			decoder->have_tma = false;
  			intel_pt_log("ERROR: Unexpected packet\n");
  			return -EAGAIN;
  
  		case INTEL_PT_OVF:
  			return intel_pt_overflow(decoder);
  
  		case INTEL_PT_TSC:
  			intel_pt_calc_tsc_timestamp(decoder);
  			break;
  
  		case INTEL_PT_TMA:
  			intel_pt_calc_tma(decoder);
  			break;
  
  		case INTEL_PT_CBR:
  			intel_pt_calc_cbr(decoder);
  			break;
  
  		case INTEL_PT_MODE_EXEC:
  			decoder->exec_mode = decoder->packet.payload;
  			break;
  
  		case INTEL_PT_PIP:
  			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
  			break;
  
  		case INTEL_PT_FUP:
  			decoder->pge = true;
  			if (decoder->packet.count)
  				intel_pt_set_last_ip(decoder);
  			break;
  
  		case INTEL_PT_MODE_TSX:
  			intel_pt_update_in_tx(decoder);
  			break;
  
  		case INTEL_PT_MTC:
  			intel_pt_calc_mtc_timestamp(decoder);
  			if (decoder->period_type == INTEL_PT_PERIOD_MTC)
  				decoder->state.type |= INTEL_PT_INSTRUCTION;
  			break;
  
  		case INTEL_PT_CYC:
  		case INTEL_PT_VMCS:
  		case INTEL_PT_MNT:
  		case INTEL_PT_PAD:
  		default:
  			break;
  		}
  	}
  }
  
  static int intel_pt_walk_fup_tip(struct intel_pt_decoder *decoder)
  {
  	int err;
  
  	if (decoder->tx_flags & INTEL_PT_ABORT_TX) {
  		decoder->tx_flags = 0;
  		decoder->state.flags &= ~INTEL_PT_IN_TX;
  		decoder->state.flags |= INTEL_PT_ABORT_TX;
  	} else {
  		decoder->state.flags |= INTEL_PT_ASYNC;
  	}
  
  	while (1) {
  		err = intel_pt_get_next_packet(decoder);
  		if (err)
  			return err;
  
  		switch (decoder->packet.type) {
  		case INTEL_PT_TNT:
  		case INTEL_PT_FUP:
  		case INTEL_PT_TRACESTOP:
  		case INTEL_PT_PSB:
  		case INTEL_PT_TSC:
  		case INTEL_PT_TMA:
  		case INTEL_PT_MODE_TSX:
  		case INTEL_PT_BAD:
  		case INTEL_PT_PSBEND:
  		case INTEL_PT_PTWRITE:
  		case INTEL_PT_PTWRITE_IP:
  		case INTEL_PT_EXSTOP:
  		case INTEL_PT_EXSTOP_IP:
  		case INTEL_PT_MWAIT:
  		case INTEL_PT_PWRE:
  		case INTEL_PT_PWRX:
  			intel_pt_log("ERROR: Missing TIP after FUP\n");
  			decoder->pkt_state = INTEL_PT_STATE_ERR3;
  			decoder->pkt_step = 0;
  			return -ENOENT;
  
  		case INTEL_PT_CBR:
  			intel_pt_calc_cbr(decoder);
  			break;
  
  		case INTEL_PT_OVF:
  			return intel_pt_overflow(decoder);
  
  		case INTEL_PT_TIP_PGD:
  			decoder->state.from_ip = decoder->ip;
  			decoder->state.to_ip = 0;
  			if (decoder->packet.count != 0) {
  				intel_pt_set_ip(decoder);
  				intel_pt_log("Omitting PGD ip " x64_fmt "\n",
  					     decoder->ip);
  			}
  			decoder->pge = false;
  			decoder->continuous_period = false;
  			return 0;
  
  		case INTEL_PT_TIP_PGE:
  			decoder->pge = true;
  			intel_pt_log("Omitting PGE ip " x64_fmt "\n",
  				     decoder->ip);
  			decoder->state.from_ip = 0;
  			if (decoder->packet.count == 0) {
  				decoder->state.to_ip = 0;
  			} else {
  				intel_pt_set_ip(decoder);
  				decoder->state.to_ip = decoder->ip;
  			}
  			return 0;
  
  		case INTEL_PT_TIP:
  			decoder->state.from_ip = decoder->ip;
  			if (decoder->packet.count == 0) {
  				decoder->state.to_ip = 0;
  			} else {
  				intel_pt_set_ip(decoder);
  				decoder->state.to_ip = decoder->ip;
  			}
  			return 0;
  
  		case INTEL_PT_PIP:
  			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
  			break;
  
  		case INTEL_PT_MTC:
  			intel_pt_calc_mtc_timestamp(decoder);
  			if (decoder->period_type == INTEL_PT_PERIOD_MTC)
  				decoder->state.type |= INTEL_PT_INSTRUCTION;
  			break;
  
  		case INTEL_PT_CYC:
  			intel_pt_calc_cyc_timestamp(decoder);
  			break;
  
  		case INTEL_PT_MODE_EXEC:
  			decoder->exec_mode = decoder->packet.payload;
  			break;
  
  		case INTEL_PT_VMCS:
  		case INTEL_PT_MNT:
  		case INTEL_PT_PAD:
  			break;
  
  		default:
  			return intel_pt_bug(decoder);
  		}
  	}
  }
  
  static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
  {
  	bool no_tip = false;
  	int err;
  
  	while (1) {
  		err = intel_pt_get_next_packet(decoder);
  		if (err)
  			return err;
  next:
  		switch (decoder->packet.type) {
  		case INTEL_PT_TNT:
  			if (!decoder->packet.count)
  				break;
  			decoder->tnt = decoder->packet;
  			decoder->pkt_state = INTEL_PT_STATE_TNT;
  			err = intel_pt_walk_tnt(decoder);
  			if (err == -EAGAIN)
  				break;
  			return err;
  
  		case INTEL_PT_TIP_PGD:
  			if (decoder->packet.count != 0)
  				intel_pt_set_last_ip(decoder);
  			decoder->pkt_state = INTEL_PT_STATE_TIP_PGD;
  			return intel_pt_walk_tip(decoder);
  
  		case INTEL_PT_TIP_PGE: {
  			decoder->pge = true;
  			if (decoder->packet.count == 0) {
  				intel_pt_log_at("Skipping zero TIP.PGE",
  						decoder->pos);
  				break;
  			}
  			intel_pt_set_ip(decoder);
  			decoder->state.from_ip = 0;
  			decoder->state.to_ip = decoder->ip;
  			return 0;
  		}
  
  		case INTEL_PT_OVF:
  			return intel_pt_overflow(decoder);
  
  		case INTEL_PT_TIP:
  			if (decoder->packet.count != 0)
  				intel_pt_set_last_ip(decoder);
  			decoder->pkt_state = INTEL_PT_STATE_TIP;
  			return intel_pt_walk_tip(decoder);
  
  		case INTEL_PT_FUP:
  			if (decoder->packet.count == 0) {
  				intel_pt_log_at("Skipping zero FUP",
  						decoder->pos);
  				no_tip = false;
  				break;
  			}
  			intel_pt_set_last_ip(decoder);
  			if (!decoder->branch_enable) {
  				decoder->ip = decoder->last_ip;
  				if (intel_pt_fup_event(decoder))
  					return 0;
  				no_tip = false;
  				break;
  			}
  			if (decoder->set_fup_mwait)
  				no_tip = true;
  			err = intel_pt_walk_fup(decoder);
  			if (err != -EAGAIN) {
  				if (err)
  					return err;
  				if (no_tip)
  					decoder->pkt_state =
  						INTEL_PT_STATE_FUP_NO_TIP;
  				else
  					decoder->pkt_state = INTEL_PT_STATE_FUP;
  				return 0;
  			}
  			if (no_tip) {
  				no_tip = false;
  				break;
  			}
  			return intel_pt_walk_fup_tip(decoder);
  
  		case INTEL_PT_TRACESTOP:
  			decoder->pge = false;
  			decoder->continuous_period = false;
  			intel_pt_clear_tx_flags(decoder);
  			decoder->have_tma = false;
  			break;
  
  		case INTEL_PT_PSB:
  			decoder->last_ip = 0;
  			decoder->have_last_ip = true;
  			intel_pt_clear_stack(&decoder->stack);
  			err = intel_pt_walk_psbend(decoder);
  			if (err == -EAGAIN)
  				goto next;
  			if (err)
  				return err;
  			break;
  
  		case INTEL_PT_PIP:
  			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
  			break;
  
  		case INTEL_PT_MTC:
  			intel_pt_calc_mtc_timestamp(decoder);
  			if (decoder->period_type != INTEL_PT_PERIOD_MTC)
  				break;
  			/*
  			 * Ensure that there has been an instruction since the
  			 * last MTC.
  			 */
  			if (!decoder->mtc_insn)
  				break;
  			decoder->mtc_insn = false;
  			/* Ensure that there is a timestamp */
  			if (!decoder->timestamp)
  				break;
  			decoder->state.type = INTEL_PT_INSTRUCTION;
  			decoder->state.from_ip = decoder->ip;
  			decoder->state.to_ip = 0;
  			decoder->mtc_insn = false;
  			return 0;
  
  		case INTEL_PT_TSC:
  			intel_pt_calc_tsc_timestamp(decoder);
  			break;
  
  		case INTEL_PT_TMA:
  			intel_pt_calc_tma(decoder);
  			break;
  
  		case INTEL_PT_CYC:
  			intel_pt_calc_cyc_timestamp(decoder);
  			break;
  
  		case INTEL_PT_CBR:
  			intel_pt_calc_cbr(decoder);
  			if (!decoder->branch_enable &&
  			    decoder->cbr != decoder->cbr_seen) {
  				decoder->cbr_seen = decoder->cbr;
  				decoder->state.type = INTEL_PT_CBR_CHG;
  				decoder->state.from_ip = decoder->ip;
  				decoder->state.to_ip = 0;
  				decoder->state.cbr_payload =
  							decoder->packet.payload;
  				return 0;
  			}
  			break;
  
  		case INTEL_PT_MODE_EXEC:
  			decoder->exec_mode = decoder->packet.payload;
  			break;
  
  		case INTEL_PT_MODE_TSX:
  			/* MODE_TSX need not be followed by FUP */
  			if (!decoder->pge) {
  				intel_pt_update_in_tx(decoder);
  				break;
  			}
  			err = intel_pt_mode_tsx(decoder, &no_tip);
  			if (err)
  				return err;
  			goto next;
  
  		case INTEL_PT_BAD: /* Does not happen */
  			return intel_pt_bug(decoder);
  
  		case INTEL_PT_PSBEND:
  		case INTEL_PT_VMCS:
  		case INTEL_PT_MNT:
  		case INTEL_PT_PAD:
  			break;
  
  		case INTEL_PT_PTWRITE_IP:
  			decoder->fup_ptw_payload = decoder->packet.payload;
  			err = intel_pt_get_next_packet(decoder);
  			if (err)
  				return err;
  			if (decoder->packet.type == INTEL_PT_FUP) {
  				decoder->set_fup_ptw = true;
  				no_tip = true;
  			} else {
  				intel_pt_log_at("ERROR: Missing FUP after PTWRITE",
  						decoder->pos);
  			}
  			goto next;
  
  		case INTEL_PT_PTWRITE:
  			decoder->state.type = INTEL_PT_PTW;
  			decoder->state.from_ip = decoder->ip;
  			decoder->state.to_ip = 0;
  			decoder->state.ptw_payload = decoder->packet.payload;
  			return 0;
  
  		case INTEL_PT_MWAIT:
  			decoder->fup_mwait_payload = decoder->packet.payload;
  			decoder->set_fup_mwait = true;
  			break;
  
  		case INTEL_PT_PWRE:
  			if (decoder->set_fup_mwait) {
  				decoder->fup_pwre_payload =
  							decoder->packet.payload;
  				decoder->set_fup_pwre = true;
  				break;
  			}
  			decoder->state.type = INTEL_PT_PWR_ENTRY;
  			decoder->state.from_ip = decoder->ip;
  			decoder->state.to_ip = 0;
  			decoder->state.pwrx_payload = decoder->packet.payload;
  			return 0;
  
  		case INTEL_PT_EXSTOP_IP:
  			err = intel_pt_get_next_packet(decoder);
  			if (err)
  				return err;
  			if (decoder->packet.type == INTEL_PT_FUP) {
  				decoder->set_fup_exstop = true;
  				no_tip = true;
  			} else {
  				intel_pt_log_at("ERROR: Missing FUP after EXSTOP",
  						decoder->pos);
  			}
  			goto next;
  
  		case INTEL_PT_EXSTOP:
  			decoder->state.type = INTEL_PT_EX_STOP;
  			decoder->state.from_ip = decoder->ip;
  			decoder->state.to_ip = 0;
  			return 0;
  
  		case INTEL_PT_PWRX:
  			decoder->state.type = INTEL_PT_PWR_EXIT;
  			decoder->state.from_ip = decoder->ip;
  			decoder->state.to_ip = 0;
  			decoder->state.pwrx_payload = decoder->packet.payload;
  			return 0;
  
  		default:
  			return intel_pt_bug(decoder);
  		}
  	}
  }
  
  static inline bool intel_pt_have_ip(struct intel_pt_decoder *decoder)
  {
  	return decoder->packet.count &&
  	       (decoder->have_last_ip || decoder->packet.count == 3 ||
  		decoder->packet.count == 6);
  }
  
  /* Walk PSB+ packets to get in sync. */
  static int intel_pt_walk_psb(struct intel_pt_decoder *decoder)
  {
  	int err;
  
  	while (1) {
  		err = intel_pt_get_next_packet(decoder);
  		if (err)
  			return err;
  
  		switch (decoder->packet.type) {
  		case INTEL_PT_TIP_PGD:
  			decoder->continuous_period = false;
  			__fallthrough;
  		case INTEL_PT_TIP_PGE:
  		case INTEL_PT_TIP:
  		case INTEL_PT_PTWRITE:
  		case INTEL_PT_PTWRITE_IP:
  		case INTEL_PT_EXSTOP:
  		case INTEL_PT_EXSTOP_IP:
  		case INTEL_PT_MWAIT:
  		case INTEL_PT_PWRE:
  		case INTEL_PT_PWRX:
  			intel_pt_log("ERROR: Unexpected packet\n");
  			return -ENOENT;
  
  		case INTEL_PT_FUP:
  			decoder->pge = true;
  			if (intel_pt_have_ip(decoder)) {
  				uint64_t current_ip = decoder->ip;
  
  				intel_pt_set_ip(decoder);
  				if (current_ip)
  					intel_pt_log_to("Setting IP",
  							decoder->ip);
  			}
  			break;
  
  		case INTEL_PT_MTC:
  			intel_pt_calc_mtc_timestamp(decoder);
  			break;
  
  		case INTEL_PT_TSC:
  			intel_pt_calc_tsc_timestamp(decoder);
  			break;
  
  		case INTEL_PT_TMA:
  			intel_pt_calc_tma(decoder);
  			break;
  
  		case INTEL_PT_CYC:
  			intel_pt_calc_cyc_timestamp(decoder);
  			break;
  
  		case INTEL_PT_CBR:
  			intel_pt_calc_cbr(decoder);
  			break;
  
  		case INTEL_PT_PIP:
  			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
  			break;
  
  		case INTEL_PT_MODE_EXEC:
  			decoder->exec_mode = decoder->packet.payload;
  			break;
  
  		case INTEL_PT_MODE_TSX:
  			intel_pt_update_in_tx(decoder);
  			break;
  
  		case INTEL_PT_TRACESTOP:
  			decoder->pge = false;
  			decoder->continuous_period = false;
  			intel_pt_clear_tx_flags(decoder);
  			__fallthrough;
  
  		case INTEL_PT_TNT:
  			decoder->have_tma = false;
  			intel_pt_log("ERROR: Unexpected packet\n");
  			if (decoder->ip)
  				decoder->pkt_state = INTEL_PT_STATE_ERR4;
  			else
  				decoder->pkt_state = INTEL_PT_STATE_ERR3;
  			return -ENOENT;
  
  		case INTEL_PT_BAD: /* Does not happen */
  			return intel_pt_bug(decoder);
  
  		case INTEL_PT_OVF:
  			return intel_pt_overflow(decoder);
  
  		case INTEL_PT_PSBEND:
  			return 0;
  
  		case INTEL_PT_PSB:
  		case INTEL_PT_VMCS:
  		case INTEL_PT_MNT:
  		case INTEL_PT_PAD:
  		default:
  			break;
  		}
  	}
  }
  
  static int intel_pt_walk_to_ip(struct intel_pt_decoder *decoder)
  {
  	int err;
  
  	while (1) {
  		err = intel_pt_get_next_packet(decoder);
  		if (err)
  			return err;
  
  		switch (decoder->packet.type) {
  		case INTEL_PT_TIP_PGD:
  			decoder->continuous_period = false;
  			__fallthrough;
  		case INTEL_PT_TIP_PGE:
  		case INTEL_PT_TIP:
  			decoder->pge = decoder->packet.type != INTEL_PT_TIP_PGD;
  			if (intel_pt_have_ip(decoder))
  				intel_pt_set_ip(decoder);
  			if (decoder->ip)
  				return 0;
  			break;
  
  		case INTEL_PT_FUP:
  			if (intel_pt_have_ip(decoder))
  				intel_pt_set_ip(decoder);
  			if (decoder->ip)
  				return 0;
  			break;
  
  		case INTEL_PT_MTC:
  			intel_pt_calc_mtc_timestamp(decoder);
  			break;
  
  		case INTEL_PT_TSC:
  			intel_pt_calc_tsc_timestamp(decoder);
  			break;
  
  		case INTEL_PT_TMA:
  			intel_pt_calc_tma(decoder);
  			break;
  
  		case INTEL_PT_CYC:
  			intel_pt_calc_cyc_timestamp(decoder);
  			break;
  
  		case INTEL_PT_CBR:
  			intel_pt_calc_cbr(decoder);
  			break;
  
  		case INTEL_PT_PIP:
  			decoder->cr3 = decoder->packet.payload & (BIT63 - 1);
  			break;
  
  		case INTEL_PT_MODE_EXEC:
  			decoder->exec_mode = decoder->packet.payload;
  			break;
  
  		case INTEL_PT_MODE_TSX:
  			intel_pt_update_in_tx(decoder);
  			break;
  
  		case INTEL_PT_OVF:
  			return intel_pt_overflow(decoder);
  
  		case INTEL_PT_BAD: /* Does not happen */
  			return intel_pt_bug(decoder);
  
  		case INTEL_PT_TRACESTOP:
  			decoder->pge = false;
  			decoder->continuous_period = false;
  			intel_pt_clear_tx_flags(decoder);
  			decoder->have_tma = false;
  			break;
  
  		case INTEL_PT_PSB:
  			decoder->last_ip = 0;
  			decoder->have_last_ip = true;
  			intel_pt_clear_stack(&decoder->stack);
  			err = intel_pt_walk_psb(decoder);
  			if (err)
  				return err;
  			if (decoder->ip) {
  				/* Do not have a sample */
  				decoder->state.type = 0;
  				return 0;
  			}
  			break;
  
  		case INTEL_PT_TNT:
  		case INTEL_PT_PSBEND:
  		case INTEL_PT_VMCS:
  		case INTEL_PT_MNT:
  		case INTEL_PT_PAD:
  		case INTEL_PT_PTWRITE:
  		case INTEL_PT_PTWRITE_IP:
  		case INTEL_PT_EXSTOP:
  		case INTEL_PT_EXSTOP_IP:
  		case INTEL_PT_MWAIT:
  		case INTEL_PT_PWRE:
  		case INTEL_PT_PWRX:
  		default:
  			break;
  		}
  	}
  }
  
  static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
  {
  	int err;
  
  	decoder->set_fup_tx_flags = false;
  	decoder->set_fup_ptw = false;
  	decoder->set_fup_mwait = false;
  	decoder->set_fup_pwre = false;
  	decoder->set_fup_exstop = false;
  
  	if (!decoder->branch_enable) {
  		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
  		decoder->overflow = false;
  		decoder->state.type = 0; /* Do not have a sample */
  		return 0;
  	}
  
  	intel_pt_log("Scanning for full IP\n");
  	err = intel_pt_walk_to_ip(decoder);
  	if (err)
  		return err;
  
  	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
  	decoder->overflow = false;
  
  	decoder->state.from_ip = 0;
  	decoder->state.to_ip = decoder->ip;
  	intel_pt_log_to("Setting IP", decoder->ip);
  
  	return 0;
  }
  
  static int intel_pt_part_psb(struct intel_pt_decoder *decoder)
  {
  	const unsigned char *end = decoder->buf + decoder->len;
  	size_t i;
  
  	for (i = INTEL_PT_PSB_LEN - 1; i; i--) {
  		if (i > decoder->len)
  			continue;
  		if (!memcmp(end - i, INTEL_PT_PSB_STR, i))
  			return i;
  	}
  	return 0;
  }
  
  static int intel_pt_rest_psb(struct intel_pt_decoder *decoder, int part_psb)
  {
  	size_t rest_psb = INTEL_PT_PSB_LEN - part_psb;
  	const char *psb = INTEL_PT_PSB_STR;
  
  	if (rest_psb > decoder->len ||
  	    memcmp(decoder->buf, psb + part_psb, rest_psb))
  		return 0;
  
  	return rest_psb;
  }
  
  static int intel_pt_get_split_psb(struct intel_pt_decoder *decoder,
  				  int part_psb)
  {
  	int rest_psb, ret;
  
  	decoder->pos += decoder->len;
  	decoder->len = 0;
  
  	ret = intel_pt_get_next_data(decoder);
  	if (ret)
  		return ret;
  
  	rest_psb = intel_pt_rest_psb(decoder, part_psb);
  	if (!rest_psb)
  		return 0;
  
  	decoder->pos -= part_psb;
  	decoder->next_buf = decoder->buf + rest_psb;
  	decoder->next_len = decoder->len - rest_psb;
  	memcpy(decoder->temp_buf, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
  	decoder->buf = decoder->temp_buf;
  	decoder->len = INTEL_PT_PSB_LEN;
  
  	return 0;
  }
  
  static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder)
  {
  	unsigned char *next;
  	int ret;
  
  	intel_pt_log("Scanning for PSB\n");
  	while (1) {
  		if (!decoder->len) {
  			ret = intel_pt_get_next_data(decoder);
  			if (ret)
  				return ret;
  		}
  
  		next = memmem(decoder->buf, decoder->len, INTEL_PT_PSB_STR,
  			      INTEL_PT_PSB_LEN);
  		if (!next) {
  			int part_psb;
  
  			part_psb = intel_pt_part_psb(decoder);
  			if (part_psb) {
  				ret = intel_pt_get_split_psb(decoder, part_psb);
  				if (ret)
  					return ret;
  			} else {
  				decoder->pos += decoder->len;
  				decoder->len = 0;
  			}
  			continue;
  		}
  
  		decoder->pkt_step = next - decoder->buf;
  		return intel_pt_get_next_packet(decoder);
  	}
  }
  
  static int intel_pt_sync(struct intel_pt_decoder *decoder)
  {
  	int err;
  
  	decoder->pge = false;
  	decoder->continuous_period = false;
  	decoder->have_last_ip = false;
  	decoder->last_ip = 0;
  	decoder->ip = 0;
  	intel_pt_clear_stack(&decoder->stack);
  
  	err = intel_pt_scan_for_psb(decoder);
  	if (err)
  		return err;
  
  	decoder->have_last_ip = true;
  	decoder->pkt_state = INTEL_PT_STATE_NO_IP;
  
  	err = intel_pt_walk_psb(decoder);
  	if (err)
  		return err;
  
  	if (decoder->ip) {
  		decoder->state.type = 0; /* Do not have a sample */
  		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
  	} else {
  		return intel_pt_sync_ip(decoder);
  	}
  
  	return 0;
  }
  
  static uint64_t intel_pt_est_timestamp(struct intel_pt_decoder *decoder)
  {
  	uint64_t est = decoder->sample_insn_cnt << 1;
  
  	if (!decoder->cbr || !decoder->max_non_turbo_ratio)
  		goto out;
  
  	est *= decoder->max_non_turbo_ratio;
  	est /= decoder->cbr;
  out:
  	return decoder->sample_timestamp + est;
  }
  
  const struct intel_pt_state *intel_pt_decode(struct intel_pt_decoder *decoder)
  {
  	int err;
  
  	do {
  		decoder->state.type = INTEL_PT_BRANCH;
  		decoder->state.flags = 0;
  
  		switch (decoder->pkt_state) {
  		case INTEL_PT_STATE_NO_PSB:
  			err = intel_pt_sync(decoder);
  			break;
  		case INTEL_PT_STATE_NO_IP:
  			decoder->have_last_ip = false;
  			decoder->last_ip = 0;
  			decoder->ip = 0;
  			__fallthrough;
  		case INTEL_PT_STATE_ERR_RESYNC:
  			err = intel_pt_sync_ip(decoder);
  			break;
  		case INTEL_PT_STATE_IN_SYNC:
  			err = intel_pt_walk_trace(decoder);
  			break;
  		case INTEL_PT_STATE_TNT:
  			err = intel_pt_walk_tnt(decoder);
  			if (err == -EAGAIN)
  				err = intel_pt_walk_trace(decoder);
  			break;
  		case INTEL_PT_STATE_TIP:
  		case INTEL_PT_STATE_TIP_PGD:
  			err = intel_pt_walk_tip(decoder);
  			break;
  		case INTEL_PT_STATE_FUP:
  			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
  			err = intel_pt_walk_fup(decoder);
  			if (err == -EAGAIN)
  				err = intel_pt_walk_fup_tip(decoder);
  			else if (!err)
  				decoder->pkt_state = INTEL_PT_STATE_FUP;
  			break;
  		case INTEL_PT_STATE_FUP_NO_TIP:
  			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
  			err = intel_pt_walk_fup(decoder);
  			if (err == -EAGAIN)
  				err = intel_pt_walk_trace(decoder);
  			break;
  		default:
  			err = intel_pt_bug(decoder);
  			break;
  		}
  	} while (err == -ENOLINK);
  
  	if (err) {
  		decoder->state.err = intel_pt_ext_err(err);
  		decoder->state.from_ip = decoder->ip;
  		decoder->sample_timestamp = decoder->timestamp;
  		decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
  	} else {
  		decoder->state.err = 0;
  		if (decoder->cbr != decoder->cbr_seen && decoder->state.type) {
  			decoder->cbr_seen = decoder->cbr;
  			decoder->state.type |= INTEL_PT_CBR_CHG;
  			decoder->state.cbr_payload = decoder->cbr_payload;
  		}
  		if (intel_pt_sample_time(decoder->pkt_state)) {
  			decoder->sample_timestamp = decoder->timestamp;
  			decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
  		}
  	}
  
  	decoder->state.timestamp = decoder->sample_timestamp;
  	decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
  	decoder->state.cr3 = decoder->cr3;
  	decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
  
  	return &decoder->state;
  }
  
  /**
   * intel_pt_next_psb - move buffer pointer to the start of the next PSB packet.
   * @buf: pointer to buffer pointer
   * @len: size of buffer
   *
   * Updates the buffer pointer to point to the start of the next PSB packet if
   * there is one, otherwise the buffer pointer is unchanged.  If @buf is updated,
   * @len is adjusted accordingly.
   *
   * Return: %true if a PSB packet is found, %false otherwise.
   */
  static bool intel_pt_next_psb(unsigned char **buf, size_t *len)
  {
  	unsigned char *next;
  
  	next = memmem(*buf, *len, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
  	if (next) {
  		*len -= next - *buf;
  		*buf = next;
  		return true;
  	}
  	return false;
  }
  
  /**
   * intel_pt_step_psb - move buffer pointer to the start of the following PSB
   *                     packet.
   * @buf: pointer to buffer pointer
   * @len: size of buffer
   *
   * Updates the buffer pointer to point to the start of the following PSB packet
   * (skipping the PSB at @buf itself) if there is one, otherwise the buffer
   * pointer is unchanged.  If @buf is updated, @len is adjusted accordingly.
   *
   * Return: %true if a PSB packet is found, %false otherwise.
   */
  static bool intel_pt_step_psb(unsigned char **buf, size_t *len)
  {
  	unsigned char *next;
  
  	if (!*len)
  		return false;
  
  	next = memmem(*buf + 1, *len - 1, INTEL_PT_PSB_STR, INTEL_PT_PSB_LEN);
  	if (next) {
  		*len -= next - *buf;
  		*buf = next;
  		return true;
  	}
  	return false;
  }
  
  /**
   * intel_pt_last_psb - find the last PSB packet in a buffer.
   * @buf: buffer
   * @len: size of buffer
   *
   * This function finds the last PSB in a buffer.
   *
   * Return: A pointer to the last PSB in @buf if found, %NULL otherwise.
   */
  static unsigned char *intel_pt_last_psb(unsigned char *buf, size_t len)
  {
  	const char *n = INTEL_PT_PSB_STR;
  	unsigned char *p;
  	size_t k;
  
  	if (len < INTEL_PT_PSB_LEN)
  		return NULL;
  
  	k = len - INTEL_PT_PSB_LEN + 1;
  	while (1) {
  		p = memrchr(buf, n[0], k);
  		if (!p)
  			return NULL;
  		if (!memcmp(p + 1, n + 1, INTEL_PT_PSB_LEN - 1))
  			return p;
  		k = p - buf;
  		if (!k)
  			return NULL;
  	}
  }
  
  /**
   * intel_pt_next_tsc - find and return next TSC.
   * @buf: buffer
   * @len: size of buffer
   * @tsc: TSC value returned
   * @rem: returns remaining size when TSC is found
   *
   * Find a TSC packet in @buf and return the TSC value.  This function assumes
   * that @buf starts at a PSB and that PSB+ will contain TSC and so stops if a
   * PSBEND packet is found.
   *
   * Return: %true if TSC is found, false otherwise.
   */
  static bool intel_pt_next_tsc(unsigned char *buf, size_t len, uint64_t *tsc,
  			      size_t *rem)
  {
  	struct intel_pt_pkt packet;
  	int ret;
  
  	while (len) {
  		ret = intel_pt_get_packet(buf, len, &packet);
  		if (ret <= 0)
  			return false;
  		if (packet.type == INTEL_PT_TSC) {
  			*tsc = packet.payload;
  			*rem = len;
  			return true;
  		}
  		if (packet.type == INTEL_PT_PSBEND)
  			return false;
  		buf += ret;
  		len -= ret;
  	}
  	return false;
  }
  
  /**
   * intel_pt_tsc_cmp - compare 7-byte TSCs.
   * @tsc1: first TSC to compare
   * @tsc2: second TSC to compare
   *
   * This function compares 7-byte TSC values allowing for the possibility that
   * TSC wrapped around.  Generally it is not possible to know if TSC has wrapped
   * around so for that purpose this function assumes the absolute difference is
   * less than half the maximum difference.
   *
   * Return: %-1 if @tsc1 is before @tsc2, %0 if @tsc1 == @tsc2, %1 if @tsc1 is
   * after @tsc2.
   */
  static int intel_pt_tsc_cmp(uint64_t tsc1, uint64_t tsc2)
  {
  	const uint64_t halfway = (1ULL << 55);
  
  	if (tsc1 == tsc2)
  		return 0;
  
  	if (tsc1 < tsc2) {
  		if (tsc2 - tsc1 < halfway)
  			return -1;
  		else
  			return 1;
  	} else {
  		if (tsc1 - tsc2 < halfway)
  			return 1;
  		else
  			return -1;
  	}
  }
  
  /**
   * intel_pt_find_overlap_tsc - determine start of non-overlapped trace data
   *                             using TSC.
   * @buf_a: first buffer
   * @len_a: size of first buffer
   * @buf_b: second buffer
   * @len_b: size of second buffer
   * @consecutive: returns true if there is data in buf_b that is consecutive
   *               to buf_a
   *
   * If the trace contains TSC we can look at the last TSC of @buf_a and the
   * first TSC of @buf_b in order to determine if the buffers overlap, and then
   * walk forward in @buf_b until a later TSC is found.  A precondition is that
   * @buf_a and @buf_b are positioned at a PSB.
   *
   * Return: A pointer into @buf_b from where non-overlapped data starts, or
   * @buf_b + @len_b if there is no non-overlapped data.
   */
  static unsigned char *intel_pt_find_overlap_tsc(unsigned char *buf_a,
  						size_t len_a,
  						unsigned char *buf_b,
  						size_t len_b, bool *consecutive)
  {
  	uint64_t tsc_a, tsc_b;
  	unsigned char *p;
  	size_t len, rem_a, rem_b;
  
  	p = intel_pt_last_psb(buf_a, len_a);
  	if (!p)
  		return buf_b; /* No PSB in buf_a => no overlap */
  
  	len = len_a - (p - buf_a);
  	if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a)) {
  		/* The last PSB+ in buf_a is incomplete, so go back one more */
  		len_a -= len;
  		p = intel_pt_last_psb(buf_a, len_a);
  		if (!p)
  			return buf_b; /* No full PSB+ => assume no overlap */
  		len = len_a - (p - buf_a);
  		if (!intel_pt_next_tsc(p, len, &tsc_a, &rem_a))
  			return buf_b; /* No TSC in buf_a => assume no overlap */
  	}
  
  	while (1) {
  		/* Ignore PSB+ with no TSC */
  		if (intel_pt_next_tsc(buf_b, len_b, &tsc_b, &rem_b)) {
  			int cmp = intel_pt_tsc_cmp(tsc_a, tsc_b);
  
  			/* Same TSC, so buffers are consecutive */
  			if (!cmp && rem_b >= rem_a) {
  				*consecutive = true;
  				return buf_b + len_b - (rem_b - rem_a);
  			}
  			if (cmp < 0)
  				return buf_b; /* tsc_a < tsc_b => no overlap */
  		}
  
  		if (!intel_pt_step_psb(&buf_b, &len_b))
  			return buf_b + len_b; /* No PSB in buf_b => no data */
  	}
  }
  
  /**
   * intel_pt_find_overlap - determine start of non-overlapped trace data.
   * @buf_a: first buffer
   * @len_a: size of first buffer
   * @buf_b: second buffer
   * @len_b: size of second buffer
   * @have_tsc: can use TSC packets to detect overlap
   * @consecutive: returns true if there is data in buf_b that is consecutive
   *               to buf_a
   *
   * When trace samples or snapshots are recorded there is the possibility that
   * the data overlaps.  Note that, for the purposes of decoding, data is only
   * useful if it begins with a PSB packet.
   *
   * Return: A pointer into @buf_b from where non-overlapped data starts, or
   * @buf_b + @len_b if there is no non-overlapped data.
   */
  unsigned char *intel_pt_find_overlap(unsigned char *buf_a, size_t len_a,
  				     unsigned char *buf_b, size_t len_b,
  				     bool have_tsc, bool *consecutive)
  {
  	unsigned char *found;
  
  	/* Buffer 'b' must start at PSB so throw away everything before that */
  	if (!intel_pt_next_psb(&buf_b, &len_b))
  		return buf_b + len_b; /* No PSB */
  
  	if (!intel_pt_next_psb(&buf_a, &len_a))
  		return buf_b; /* No overlap */
  
  	if (have_tsc) {
  		found = intel_pt_find_overlap_tsc(buf_a, len_a, buf_b, len_b,
  						  consecutive);
  		if (found)
  			return found;
  	}
  
  	/*
  	 * Buffer 'b' cannot end within buffer 'a' so, for comparison purposes,
  	 * we can ignore the first part of buffer 'a'.
  	 */
  	while (len_b < len_a) {
  		if (!intel_pt_step_psb(&buf_a, &len_a))
  			return buf_b; /* No overlap */
  	}
  
  	/* Now len_b >= len_a */
  	while (1) {
  		/* Potential overlap so check the bytes */
  		found = memmem(buf_a, len_a, buf_b, len_a);
  		if (found) {
  			*consecutive = true;
  			return buf_b + len_a;
  		}
  
  		/* Try again at next PSB in buffer 'a' */
  		if (!intel_pt_step_psb(&buf_a, &len_a))
  			return buf_b; /* No overlap */
  	}
  }
  