Contributors: 6
Author Tokens Token Proportion Commits Commit Proportion
Adrian Hunter 18809 99.87% 84 93.33%
Andi Kleen 11 0.06% 1 1.11%
Arnaldo Carvalho de Melo 7 0.04% 2 2.22%
Liam R. Howlett 3 0.02% 1 1.11%
Colin Ian King 2 0.01% 1 1.11%
Thomas Gleixner 2 0.01% 1 1.11%
Total 18834 90

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976977978979980981982983984985986987988989990991992993994995996997998999100010011002100310041005100610071008100910101011101210131014101510161017101810191020102110221023102410251026102710281029103010311032103310341035103610371038103910401041104210431044104510461047104810491050105110521053105410551056105710581059106010611062106310641065106610671068106910701071107210731074107510761077107810791080108110821083108410851086108710881089109010911092109310941095109610971098109911001101110211031104110511061107110811091110111111121113111411151116111711181119112011211122112311241125112611271128112911301131113211331134113511361137113811391140114111421143114411451146114711481149115011511152115311541155115611571158115911601161116211631164116511661167116811691170117111721173117411751176117711781179118011811182118311841185118611871188118911901191119211931194119511961197119811991200120112021203120412051206120712081209121012111212121312141215121612171218121912201221122212231224122512261227122812291230123112321233123412351236123712381239124012411242124312441245124612471248124912501251125212531254125512561257125812591260126112621263126412651266126712681269127012711272127312741275127612771278127912801281128212831284128512861287128812891290129112921293129412951296129712981299130013011302130313041305130613071308130913101311131213131314131513161317131813191320132113221323132413251326132713281329133013311332133313341335133613371338133913401341134213431344134513461347134813491350135113521353135413551356135713581359136013611362136313641365136613671368136913701371137213731374137513761377137813791380138113821383138413851386138713881389139013911392139313941395139613971398139914001401140214031404140514061407140814091410141114121413141414151416141714181419142014211422142314241425142614271428142914301431143214331434143514361437143814391440144114421443144414451446144714481449145014511452145314541455145614571458145914601461146214631464146514661467146814691470147114721473147414751476147714781479148014811482148314841485148614871488148914901491149214931494149514961497149814991500150115021503150415051506150715081509151015111512151315141515151615171518151915201521152215231524152515261527152815291530153115321533153415351536153715381539154015411542154315441545154615471548154915501551155215531554155515561557155815591560156115621563156415651566156715681569157015711572157315741575157615771578157915801581158215831584158515861587158815891590159115921593159415951596159715981599160016011602160316041605160616071608160916101611161216131614161516161617161816191620162116221623162416251626162716281629163016311632163316341635163616371638163916401641164216431644164516461647164816491650165116521653165416551656165716581659166016611662166316641665166616671668166916701671167216731674167516761677167816791680168116821683168416851686168716881689169016911692169316941695169616971698169917001701170217031704170517061707170817091710171117121713171417151716171717181719172017211722172317241725172617271728172917301731173217331734173517361737173817391740174117421743174417451746174717481749175017511752175317541755175617571758175917601761176217631764176517661767176817691770177117721773177417751776177717781779178017811782178317841785178617871788178917901791179217931794179517961797179817991800180118021803180418051806180718081809181018111812181318141815181618171818181918201821182218231824182518261827182818291830183118321833183418351836183718381839184018411842184318441845184618471848184918501851185218531854185518561857185818591860186118621863186418651866186718681869187018711872187318741875187618771878187918801881188218831884188518861887188818891890189118921893189418951896189718981899190019011902190319041905190619071908190919101911191219131914191519161917191819191920192119221923192419251926192719281929193019311932193319341935193619371938193919401941194219431944194519461947194819491950195119521953195419551956195719581959196019611962196319641965196619671968196919701971197219731974197519761977197819791980198119821983198419851986198719881989199019911992199319941995199619971998199920002001200220032004200520062007200820092010201120122013201420152016201720182019202020212022202320242025202620272028202920302031203220332034203520362037203820392040204120422043204420452046204720482049205020512052205320542055205620572058205920602061206220632064206520662067206820692070207120722073207420752076207720782079208020812082208320842085208620872088208920902091209220932094209520962097209820992100210121022103210421052106210721082109211021112112211321142115211621172118211921202121212221232124212521262127212821292130213121322133213421352136213721382139214021412142214321442145214621472148214921502151215221532154215521562157215821592160216121622163216421652166216721682169217021712172217321742175217621772178217921802181218221832184218521862187218821892190219121922193219421952196219721982199220022012202220322042205220622072208220922102211221222132214221522162217221822192220222122222223222422252226222722282229223022312232223322342235223622372238223922402241224222432244224522462247224822492250225122522253225422552256225722582259226022612262226322642265226622672268226922702271227222732274227522762277227822792280228122822283228422852286228722882289229022912292229322942295229622972298229923002301230223032304230523062307230823092310231123122313231423152316231723182319232023212322232323242325232623272328232923302331233223332334233523362337233823392340234123422343234423452346234723482349235023512352235323542355235623572358235923602361236223632364236523662367236823692370237123722373237423752376237723782379238023812382238323842385238623872388238923902391239223932394239523962397239823992400240124022403240424052406240724082409241024112412241324142415241624172418241924202421242224232424242524262427242824292430243124322433243424352436243724382439244024412442244324442445244624472448244924502451245224532454245524562457245824592460246124622463246424652466246724682469247024712472247324742475247624772478247924802481248224832484248524862487248824892490249124922493249424952496249724982499250025012502250325042505250625072508250925102511251225132514251525162517251825192520252125222523252425252526252725282529253025312532253325342535253625372538253925402541254225432544254525462547254825492550255125522553255425552556255725582559256025612562256325642565256625672568256925702571257225732574257525762577257825792580258125822583258425852586258725882589259025912592259325942595259625972598259926002601260226032604260526062607260826092610261126122613261426152616261726182619262026212622262326242625262626272628262926302631263226332634263526362637263826392640264126422643264426452646264726482649265026512652265326542655265626572658265926602661266226632664266526662667266826692670267126722673267426752676267726782679268026812682268326842685268626872688268926902691269226932694269526962697269826992700270127022703270427052706270727082709271027112712271327142715271627172718271927202721272227232724272527262727272827292730273127322733273427352736273727382739274027412742274327442745274627472748274927502751275227532754275527562757275827592760276127622763276427652766276727682769277027712772277327742775277627772778277927802781278227832784278527862787278827892790279127922793279427952796279727982799280028012802280328042805280628072808280928102811281228132814281528162817281828192820282128222823282428252826282728282829283028312832283328342835283628372838283928402841284228432844284528462847284828492850285128522853285428552856285728582859286028612862286328642865286628672868286928702871287228732874287528762877287828792880288128822883288428852886288728882889289028912892289328942895289628972898289929002901290229032904290529062907290829092910291129122913291429152916291729182919292029212922292329242925292629272928292929302931293229332934293529362937293829392940294129422943294429452946294729482949295029512952295329542955295629572958295929602961296229632964296529662967296829692970297129722973297429752976297729782979298029812982298329842985298629872988298929902991299229932994299529962997299829993000300130023003300430053006300730083009301030113012301330143015301630173018301930203021302230233024302530263027302830293030303130323033303430353036303730383039304030413042304330443045304630473048304930503051305230533054305530563057305830593060306130623063306430653066306730683069307030713072307330743075307630773078307930803081308230833084308530863087308830893090309130923093309430953096309730983099310031013102310331043105310631073108310931103111311231133114311531163117311831193120312131223123312431253126312731283129313031313132313331343135313631373138313931403141314231433144314531463147314831493150315131523153315431553156315731583159316031613162316331643165316631673168316931703171317231733174317531763177317831793180318131823183318431853186318731883189319031913192319331943195319631973198319932003201320232033204320532063207320832093210321132123213321432153216321732183219322032213222322332243225322632273228322932303231323232333234323532363237323832393240324132423243324432453246324732483249325032513252325332543255325632573258325932603261326232633264326532663267326832693270327132723273327432753276327732783279328032813282328332843285328632873288328932903291329232933294329532963297329832993300330133023303330433053306330733083309331033113312331333143315331633173318331933203321332233233324332533263327332833293330333133323333333433353336333733383339334033413342334333443345334633473348334933503351335233533354335533563357335833593360336133623363336433653366336733683369337033713372337333743375337633773378337933803381338233833384338533863387338833893390339133923393339433953396339733983399340034013402340334043405340634073408340934103411341234133414341534163417341834193420342134223423342434253426342734283429343034313432343334343435343634373438343934403441344234433444344534463447344834493450345134523453345434553456345734583459346034613462346334643465346634673468346934703471347234733474347534763477347834793480348134823483348434853486348734883489349034913492349334943495349634973498349935003501350235033504350535063507350835093510351135123513351435153516351735183519352035213522352335243525352635273528352935303531353235333534353535363537353835393540354135423543354435453546354735483549355035513552355335543555355635573558355935603561356235633564356535663567356835693570357135723573357435753576357735783579358035813582358335843585358635873588358935903591359235933594359535963597359835993600360136023603360436053606360736083609361036113612361336143615361636173618361936203621362236233624362536263627362836293630363136323633363436353636363736383639364036413642364336443645364636473648364936503651365236533654365536563657365836593660366136623663366436653666366736683669367036713672367336743675367636773678367936803681368236833684368536863687368836893690369136923693369436953696369736983699370037013702370337043705370637073708370937103711371237133714371537163717371837193720372137223723372437253726372737283729373037313732373337343735373637373738373937403741374237433744374537463747374837493750375137523753375437553756375737583759376037613762376337643765376637673768376937703771377237733774377537763777377837793780378137823783378437853786378737883789379037913792379337943795379637973798379938003801380238033804380538063807380838093810381138123813381438153816381738183819382038213822382338243825382638273828382938303831383238333834383538363837383838393840384138423843384438453846384738483849385038513852385338543855385638573858385938603861386238633864386538663867386838693870387138723873387438753876387738783879388038813882388338843885388638873888388938903891389238933894389538963897389838993900390139023903390439053906390739083909391039113912391339143915391639173918391939203921392239233924392539263927392839293930393139323933393439353936393739383939394039413942394339443945394639473948394939503951395239533954395539563957395839593960396139623963396439653966396739683969397039713972397339743975397639773978397939803981398239833984398539863987398839893990399139923993399439953996399739983999400040014002400340044005400640074008400940104011401240134014401540164017401840194020402140224023402440254026402740284029403040314032403340344035403640374038403940404041404240434044404540464047404840494050405140524053405440554056405740584059406040614062406340644065406640674068406940704071407240734074407540764077407840794080408140824083408440854086408740884089409040914092409340944095409640974098409941004101410241034104410541064107410841094110411141124113411441154116411741184119412041214122412341244125412641274128412941304131413241334134413541364137413841394140414141424143414441454146414741484149415041514152415341544155415641574158415941604161416241634164416541664167416841694170417141724173417441754176417741784179418041814182418341844185418641874188418941904191419241934194419541964197419841994200420142024203420442054206420742084209421042114212421342144215421642174218421942204221422242234224422542264227422842294230423142324233423442354236423742384239424042414242424342444245424642474248424942504251425242534254425542564257425842594260426142624263426442654266426742684269427042714272427342744275427642774278427942804281428242834284428542864287428842894290429142924293429442954296429742984299430043014302430343044305430643074308430943104311431243134314431543164317431843194320432143224323432443254326432743284329433043314332433343344335433643374338433943404341434243434344434543464347434843494350435143524353435443554356435743584359436043614362436343644365436643674368436943704371437243734374437543764377437843794380438143824383438443854386438743884389439043914392439343944395439643974398439944004401440244034404440544064407440844094410441144124413441444154416441744184419442044214422442344244425442644274428442944304431443244334434443544364437443844394440444144424443444444454446444744484449445044514452445344544455445644574458445944604461446244634464446544664467446844694470447144724473447444754476447744784479448044814482448344844485448644874488448944904491449244934494449544964497449844994500450145024503450445054506450745084509451045114512451345144515
// SPDX-License-Identifier: GPL-2.0-only
/*
 * intel_pt_decoder.c: Intel Processor Trace support
 * Copyright (c) 2013-2014, Intel Corporation.
 */

#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 <linux/string.h>
#include <linux/zalloc.h>

#include "../auxtrace.h"

#include "intel-pt-insn-decoder.h"
#include "intel-pt-pkt-decoder.h"
#include "intel-pt-decoder.h"
#include "intel-pt-log.h"

#define BITULL(x) (1ULL << (x))

/* IA32_RTIT_CTL MSR bits */
#define INTEL_PT_CYC_ENABLE		BITULL(1)
#define INTEL_PT_CYC_THRESHOLD		(BITULL(22) | BITULL(21) | BITULL(20) | BITULL(19))
#define INTEL_PT_CYC_THRESHOLD_SHIFT	19

#define INTEL_PT_BLK_SIZE 1024

#define BIT63 (((uint64_t)1 << 63))

#define SEVEN_BYTES 0xffffffffffffffULL

#define NO_VMCS 0xffffffffffULL

#define INTEL_PT_RETURN 1

/*
 * Default maximum number of loops with no packets consumed i.e. stuck in a
 * loop.
 */
#define INTEL_PT_MAX_LOOPS 100000

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_p_once {
	INTEL_PT_PRT_ONCE_UNK_VMCS,
	INTEL_PT_PRT_ONCE_ERANGE,
};

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_CONT,
	INTEL_PT_STATE_TNT,
	INTEL_PT_STATE_TIP,
	INTEL_PT_STATE_TIP_PGD,
	INTEL_PT_STATE_FUP,
	INTEL_PT_STATE_FUP_NO_TIP,
	INTEL_PT_STATE_FUP_IN_PSB,
	INTEL_PT_STATE_RESAMPLE,
	INTEL_PT_STATE_VM_TIME_CORRELATION,
};

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_CONT:
	case INTEL_PT_STATE_RESAMPLE:
	case INTEL_PT_STATE_VM_TIME_CORRELATION:
		return true;
	case INTEL_PT_STATE_TNT:
	case INTEL_PT_STATE_TIP:
	case INTEL_PT_STATE_TIP_PGD:
	case INTEL_PT_STATE_FUP:
	case INTEL_PT_STATE_FUP_NO_TIP:
	case INTEL_PT_STATE_FUP_IN_PSB:
		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);
	int (*lookahead)(void *data, intel_pt_lookahead_cb_t cb, void *cb_data);
	struct intel_pt_vmcs_info *(*findnew_vmcs_info)(void *data, uint64_t vmcs);
	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;
	bool in_psb;
	bool hop;
	bool leap;
	bool emulated_ptwrite;
	bool vm_time_correlation;
	bool vm_tm_corr_dry_run;
	bool vm_tm_corr_reliable;
	bool vm_tm_corr_same_buf;
	bool vm_tm_corr_continuous;
	bool nr;
	bool next_nr;
	bool iflag;
	bool next_iflag;
	enum intel_pt_param_flags flags;
	uint64_t pos;
	uint64_t last_ip;
	uint64_t ip;
	uint64_t pip_payload;
	uint64_t timestamp;
	uint64_t tsc_timestamp;
	uint64_t ref_timestamp;
	uint64_t buf_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;
	uint64_t first_timestamp;
	uint64_t last_reliable_timestamp;
	uint64_t vmcs;
	uint64_t print_once;
	uint64_t last_ctc;
	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;
	enum intel_pt_pkt_ctx pkt_ctx;
	enum intel_pt_pkt_ctx prev_pkt_ctx;
	enum intel_pt_blk_type blk_type;
	int blk_type_pos;
	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;
	uint64_t tot_cyc_cnt;
	uint64_t sample_tot_cyc_cnt;
	uint64_t base_cyc_cnt;
	uint64_t cyc_cnt_timestamp;
	uint64_t ctl;
	uint64_t cyc_threshold;
	double tsc_to_cyc;
	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;
	bool set_fup_bep;
	bool set_fup_cfe_ip;
	bool set_fup_cfe;
	bool set_fup_mode_exec;
	bool sample_cyc;
	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;
	struct intel_pt_pkt fup_cfe_pkt;
	int max_loops;
	int no_progress;
	int stuck_ip_prd;
	int stuck_ip_cnt;
	uint64_t psb_ip;
	const unsigned char *next_buf;
	size_t next_len;
	unsigned char temp_buf[INTEL_PT_PKT_MAX_SZ];
	int evd_cnt;
	struct intel_pt_evd evd[INTEL_PT_MAX_EVDS];
};

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;
}

__printf(1, 2)
static void p_log(const char *fmt, ...)
{
	char buf[512];
	va_list args;

	va_start(args, fmt);
	vsnprintf(buf, sizeof(buf), fmt, args);
	va_end(args);

	fprintf(stderr, "%s\n", buf);
	intel_pt_log("%s\n", buf);
}

static bool intel_pt_print_once(struct intel_pt_decoder *decoder,
				enum intel_pt_p_once id)
{
	uint64_t bit = 1ULL << id;

	if (decoder->print_once & bit)
		return false;
	decoder->print_once |= bit;
	return true;
}

static uint64_t intel_pt_cyc_threshold(uint64_t ctl)
{
	if (!(ctl & INTEL_PT_CYC_ENABLE))
		return 0;

	return (ctl & INTEL_PT_CYC_THRESHOLD) >> INTEL_PT_CYC_THRESHOLD_SHIFT;
}

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->lookahead          = params->lookahead;
	decoder->findnew_vmcs_info  = params->findnew_vmcs_info;
	decoder->data               = params->data;
	decoder->return_compression = params->return_compression;
	decoder->branch_enable      = params->branch_enable;
	decoder->hop                = params->quick >= 1;
	decoder->leap               = params->quick >= 2;
	decoder->vm_time_correlation = params->vm_time_correlation;
	decoder->vm_tm_corr_dry_run = params->vm_tm_corr_dry_run;
	decoder->first_timestamp    = params->first_timestamp;
	decoder->last_reliable_timestamp = params->first_timestamp;
	decoder->max_loops          = params->max_loops ? params->max_loops : INTEL_PT_MAX_LOOPS;

	decoder->flags              = params->flags;

	decoder->ctl                = params->ctl;
	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;

	decoder->cyc_threshold = intel_pt_cyc_threshold(decoder->ctl);

	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;
	}

	/*
	 * A TSC packet can slip past MTC packets so that the timestamp appears
	 * to go backwards. One estimate is that can be up to about 40 CPU
	 * cycles, which is certainly less than 0x1000 TSC ticks, but accept
	 * slippage an order of magnitude more to be on the safe side.
	 */
	decoder->tsc_slip = 0x10000;

	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);

	if (decoder->hop)
		intel_pt_log("Hop mode: decoding FUP and TIPs, but not TNT\n");

	return decoder;
}

void intel_pt_set_first_timestamp(struct intel_pt_decoder *decoder,
				  uint64_t first_timestamp)
{
	decoder->first_timestamp = first_timestamp;
}

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;
	case -ECONNRESET:
		return INTEL_PT_ERR_EPTW;
	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 (refer perf config intel-pt.max-loops)",
	[INTEL_PT_ERR_EPTW]   = "Broken emulated ptwrite",
};

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 inline void intel_pt_update_pip(struct intel_pt_decoder *decoder)
{
	decoder->pip_payload = decoder->packet.payload;
}

static inline void intel_pt_update_nr(struct intel_pt_decoder *decoder)
{
	decoder->next_nr = decoder->pip_payload & 1;
}

static inline void intel_pt_set_nr(struct intel_pt_decoder *decoder)
{
	decoder->nr = decoder->pip_payload & 1;
	decoder->next_nr = decoder->nr;
}

static inline void intel_pt_set_pip(struct intel_pt_decoder *decoder)
{
	intel_pt_update_pip(decoder);
	intel_pt_set_nr(decoder);
}

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 inline void intel_pt_update_sample_time(struct intel_pt_decoder *decoder)
{
	decoder->sample_timestamp = decoder->timestamp;
	decoder->sample_insn_cnt = decoder->timestamp_insn_cnt;
	decoder->state.cycles = decoder->tot_cyc_cnt;
}

static void intel_pt_reposition(struct intel_pt_decoder *decoder)
{
	decoder->ip = 0;
	decoder->pkt_state = INTEL_PT_STATE_NO_PSB;
	decoder->timestamp = 0;
	decoder->have_tma = false;
}

static int intel_pt_get_data(struct intel_pt_decoder *decoder, bool reposition)
{
	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;
	}
	decoder->buf_timestamp = buffer.ref_timestamp;
	if (!buffer.consecutive || reposition) {
		intel_pt_reposition(decoder);
		decoder->ref_timestamp = buffer.ref_timestamp;
		decoder->state.trace_nr = buffer.trace_nr;
		decoder->vm_tm_corr_same_buf = false;
		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,
				  bool reposition)
{
	if (!decoder->next_buf)
		return intel_pt_get_data(decoder, reposition);

	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, false);
	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;

	decoder->prev_pkt_ctx = decoder->pkt_ctx;
	ret = intel_pt_get_packet(buf, len, &decoder->packet, &decoder->pkt_ctx);
	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;
	enum intel_pt_pkt_ctx pkt_ctx = decoder->pkt_ctx;
	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,
						  &pkt_ctx);
			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:
	case INTEL_PT_BBP:
	case INTEL_PT_BIP:
	case INTEL_PT_BEP:
	case INTEL_PT_BEP_IP:
	case INTEL_PT_CFE:
	case INTEL_PT_CFE_IP:
	case INTEL_PT_EVD:
		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, false);
			if (ret)
				return ret;
		}

		decoder->prev_pkt_ctx = decoder->pkt_ctx;
		ret = intel_pt_get_packet(decoder->buf, decoder->len,
					  &decoder->packet, &decoder->pkt_ctx);
		if (ret == INTEL_PT_NEED_MORE_BYTES && BITS_PER_LONG == 32 &&
		    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;
		}
	}

	if (masked_timestamp < decoder->last_masked_timestamp)
		return decoder->period_ticks;

	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;
		if (masked_timestamp > decoder->last_masked_timestamp)
			decoder->last_masked_timestamp = masked_timestamp;
		else
			decoder->last_masked_timestamp += decoder->period_ticks;
		break;
	case INTEL_PT_PERIOD_NONE:
	case INTEL_PT_PERIOD_MTC:
	default:
		break;
	}

	decoder->state.type |= INTEL_PT_INSTRUCTION;
}

/*
 * Sample FUP instruction at the same time as reporting the FUP event, so the
 * instruction sample gets the same flags as the FUP event.
 */
static void intel_pt_sample_fup_insn(struct intel_pt_decoder *decoder)
{
	struct intel_pt_insn intel_pt_insn;
	uint64_t max_insn_cnt, insn_cnt = 0;
	int err;

	decoder->state.insn_op = INTEL_PT_OP_OTHER;
	decoder->state.insn_len = 0;

	if (!decoder->branch_enable || !decoder->pge || decoder->hop ||
	    decoder->ip != decoder->last_ip)
		return;

	if (!decoder->mtc_insn)
		decoder->mtc_insn = true;

	max_insn_cnt = intel_pt_next_sample(decoder);
	if (max_insn_cnt != 1)
		return;

	err = decoder->walk_insn(&intel_pt_insn, &insn_cnt, &decoder->ip,
				 0, max_insn_cnt, decoder->data);
	/* Ignore error, it will be reported next walk anyway */
	if (err)
		return;

	if (intel_pt_insn.branch != INTEL_PT_BR_NO_BRANCH) {
		intel_pt_log_at("ERROR: Unexpected branch at FUP instruction", decoder->ip);
		return;
	}

	decoder->tot_insn_cnt += insn_cnt;
	decoder->timestamp_insn_cnt += insn_cnt;
	decoder->sample_insn_cnt += insn_cnt;
	decoder->period_insn_cnt += insn_cnt;

	intel_pt_sample_insn(decoder);

	decoder->state.type |= INTEL_PT_INSTRUCTION;
	decoder->ip += intel_pt_insn.length;
}

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 > decoder->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 void intel_pt_mode_exec_status(struct intel_pt_decoder *decoder)
{
	bool iflag = decoder->packet.count & INTEL_PT_IFLAG;

	decoder->exec_mode = decoder->packet.payload;
	decoder->iflag = iflag;
	decoder->next_iflag = iflag;
	decoder->state.from_iflag = iflag;
	decoder->state.to_iflag = iflag;
}

static void intel_pt_mode_exec(struct intel_pt_decoder *decoder)
{
	bool iflag = decoder->packet.count & INTEL_PT_IFLAG;

	decoder->exec_mode = decoder->packet.payload;
	decoder->next_iflag = iflag;
}

static void intel_pt_sample_iflag(struct intel_pt_decoder *decoder)
{
	decoder->state.type |= INTEL_PT_IFLAG_CHG;
	decoder->state.from_iflag = decoder->iflag;
	decoder->state.to_iflag = decoder->next_iflag;
	decoder->iflag = decoder->next_iflag;
}

static void intel_pt_sample_iflag_chg(struct intel_pt_decoder *decoder)
{
	if (decoder->iflag != decoder->next_iflag)
		intel_pt_sample_iflag(decoder);
}

static void intel_pt_clear_fup_event(struct intel_pt_decoder *decoder)
{
	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;
	decoder->set_fup_bep = false;
	decoder->set_fup_cfe_ip = false;
	decoder->set_fup_cfe = false;
	decoder->evd_cnt = 0;
	decoder->set_fup_mode_exec = false;
	decoder->iflag = decoder->next_iflag;
}

static bool intel_pt_fup_event(struct intel_pt_decoder *decoder, bool no_tip)
{
	enum intel_pt_sample_type type = decoder->state.type;
	bool sample_fup_insn = false;
	bool ret = false;

	decoder->state.type &= ~INTEL_PT_BRANCH;
	decoder->state.insn_op = INTEL_PT_OP_OTHER;
	decoder->state.insn_len = 0;

	if (decoder->set_fup_cfe_ip || decoder->set_fup_cfe) {
		bool ip = decoder->set_fup_cfe_ip;

		decoder->set_fup_cfe_ip = false;
		decoder->set_fup_cfe = false;
		decoder->state.type |= INTEL_PT_EVT;
		if (!ip && decoder->pge)
			decoder->state.type |= INTEL_PT_BRANCH;
		decoder->state.cfe_type = decoder->fup_cfe_pkt.count;
		decoder->state.cfe_vector = decoder->fup_cfe_pkt.payload;
		decoder->state.evd_cnt = decoder->evd_cnt;
		decoder->state.evd = decoder->evd;
		decoder->evd_cnt = 0;
		if (ip || decoder->pge)
			decoder->state.flags |= INTEL_PT_FUP_IP;
		ret = true;
	}
	if (decoder->set_fup_mode_exec) {
		decoder->set_fup_mode_exec = false;
		intel_pt_sample_iflag(decoder);
		sample_fup_insn = no_tip;
		ret = true;
	}
	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;
		if (decoder->fup_tx_flags & INTEL_PT_ABORT_TX)
			decoder->state.type |= INTEL_PT_BRANCH;
		decoder->state.flags = decoder->fup_tx_flags;
		ret = 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.ptw_payload = decoder->fup_ptw_payload;
		ret = true;
	}
	if (decoder->set_fup_mwait) {
		decoder->set_fup_mwait = false;
		decoder->state.type |= INTEL_PT_MWAIT_OP;
		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.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.flags |= INTEL_PT_FUP_IP;
		ret = true;
	}
	if (decoder->set_fup_bep) {
		decoder->set_fup_bep = false;
		decoder->state.type |= INTEL_PT_BLK_ITEMS;
		ret = true;
	}
	if (decoder->overflow) {
		decoder->overflow = false;
		if (!ret && !decoder->pge) {
			if (decoder->hop) {
				decoder->state.type = 0;
				decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
			}
			decoder->pge = true;
			decoder->state.type |= INTEL_PT_BRANCH | INTEL_PT_TRACE_BEGIN;
			decoder->state.from_ip = 0;
			decoder->state.to_ip = decoder->ip;
			return true;
		}
	}
	if (ret) {
		decoder->state.from_ip = decoder->ip;
		decoder->state.to_ip = 0;
		if (sample_fup_insn)
			intel_pt_sample_fup_insn(decoder);
	} else {
		decoder->state.type = type;
	}
	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)) {
			bool no_tip = decoder->pkt_state != INTEL_PT_STATE_FUP;

			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
			if (intel_pt_fup_event(decoder, no_tip) && no_tip)
				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.type |= INTEL_PT_TRACE_END;
		intel_pt_update_nr(decoder);
		return 0;
	}
	if (err == INTEL_PT_RETURN)
		return 0;
	if (err)
		return err;

	intel_pt_update_nr(decoder);
	intel_pt_sample_iflag_chg(decoder);

	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;
			if (decoder->packet.count == 0) {
				decoder->state.to_ip = 0;
			} else {
				decoder->state.to_ip = decoder->last_ip;
				decoder->ip = decoder->last_ip;
			}
			decoder->state.type |= INTEL_PT_TRACE_END;
		} 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 = to_ip;
			decoder->state.type |= INTEL_PT_TRACE_END;
			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);
}

struct eptw_data {
	int bit_countdown;
	uint64_t payload;
};

static int intel_pt_eptw_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
{
	struct eptw_data *data = pkt_info->data;
	int nr_bits;

	switch (pkt_info->packet.type) {
	case INTEL_PT_PAD:
	case INTEL_PT_MNT:
	case INTEL_PT_MODE_EXEC:
	case INTEL_PT_MODE_TSX:
	case INTEL_PT_MTC:
	case INTEL_PT_FUP:
	case INTEL_PT_CYC:
	case INTEL_PT_CBR:
	case INTEL_PT_TSC:
	case INTEL_PT_TMA:
	case INTEL_PT_PIP:
	case INTEL_PT_VMCS:
	case INTEL_PT_PSB:
	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:
	case INTEL_PT_BBP:
	case INTEL_PT_BIP:
	case INTEL_PT_BEP:
	case INTEL_PT_BEP_IP:
	case INTEL_PT_CFE:
	case INTEL_PT_CFE_IP:
	case INTEL_PT_EVD:
		break;

	case INTEL_PT_TNT:
		nr_bits = data->bit_countdown;
		if (nr_bits > pkt_info->packet.count)
			nr_bits = pkt_info->packet.count;
		data->payload <<= nr_bits;
		data->payload |= pkt_info->packet.payload >> (64 - nr_bits);
		data->bit_countdown -= nr_bits;
		return !data->bit_countdown;

	case INTEL_PT_TIP_PGE:
	case INTEL_PT_TIP_PGD:
	case INTEL_PT_TIP:
	case INTEL_PT_BAD:
	case INTEL_PT_OVF:
	case INTEL_PT_TRACESTOP:
	default:
		return 1;
	}

	return 0;
}

static int intel_pt_emulated_ptwrite(struct intel_pt_decoder *decoder)
{
	int n = 64 - decoder->tnt.count;
	struct eptw_data data = {
		.bit_countdown = n,
		.payload = decoder->tnt.payload >> n,
	};

	decoder->emulated_ptwrite = false;
	intel_pt_log("Emulated ptwrite detected\n");

	intel_pt_pkt_lookahead(decoder, intel_pt_eptw_lookahead_cb, &data);
	if (data.bit_countdown)
		return -ECONNRESET;

	decoder->state.type = INTEL_PT_PTW;
	decoder->state.from_ip = decoder->ip;
	decoder->state.to_ip = 0;
	decoder->state.ptw_payload = data.payload;
	return 0;
}

static int intel_pt_walk_tnt(struct intel_pt_decoder *decoder)
{
	struct intel_pt_insn intel_pt_insn;
	int err;

	while (1) {
		if (decoder->emulated_ptwrite)
			return intel_pt_emulated_ptwrite(decoder);
		err = intel_pt_walk_insn(decoder, &intel_pt_insn, 0);
		if (err == INTEL_PT_RETURN) {
			decoder->emulated_ptwrite = intel_pt_insn.emulated_ptwrite;
			return 0;
		}
		if (err) {
			decoder->emulated_ptwrite = false;
			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_TNT_CONT;
			else
				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;
			intel_pt_update_nr(decoder);
			intel_pt_sample_iflag_chg(decoder);
			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_TNT_CONT;
			else
				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->sample_cyc = false;
			decoder->ip += intel_pt_insn.length;
			if (!decoder->tnt.count) {
				intel_pt_update_sample_time(decoder);
				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 int intel_pt_evd(struct intel_pt_decoder *decoder)
{
	if (decoder->evd_cnt >= INTEL_PT_MAX_EVDS) {
		intel_pt_log_at("ERROR: Too many EVD packets", decoder->pos);
		return -ENOSYS;
	}
	decoder->evd[decoder->evd_cnt++] = (struct intel_pt_evd){
		.type = decoder->packet.count,
		.payload = decoder->packet.payload,
	};
	return 0;
}

static uint64_t intel_pt_8b_tsc(uint64_t timestamp, uint64_t ref_timestamp)
{
	timestamp |= (ref_timestamp & (0xffULL << 56));

	if (timestamp < ref_timestamp) {
		if (ref_timestamp - timestamp > (1ULL << 55))
			timestamp += (1ULL << 56);
	} else {
		if (timestamp - ref_timestamp > (1ULL << 55))
			timestamp -= (1ULL << 56);
	}

	return timestamp;
}

/* For use only when decoder->vm_time_correlation is true */
static bool intel_pt_time_in_range(struct intel_pt_decoder *decoder,
				   uint64_t timestamp)
{
	uint64_t max_timestamp = decoder->buf_timestamp;

	if (!max_timestamp) {
		max_timestamp = decoder->last_reliable_timestamp +
				0x400000000ULL;
	}
	return timestamp >= decoder->last_reliable_timestamp &&
	       timestamp < decoder->buf_timestamp;
}

static void intel_pt_calc_tsc_timestamp(struct intel_pt_decoder *decoder)
{
	uint64_t timestamp;
	bool bad = false;

	decoder->have_tma = false;

	if (decoder->ref_timestamp) {
		timestamp = intel_pt_8b_tsc(decoder->packet.payload,
					    decoder->ref_timestamp);
		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) {
			if (!decoder->buf_timestamp ||
			    (timestamp + (1ULL << 56) < decoder->buf_timestamp)) {
				intel_pt_log_to("Wraparound timestamp", timestamp);
				timestamp += (1ULL << 56);
				decoder->tsc_timestamp = timestamp;
			} else {
				intel_pt_log_to("Suppressing bad timestamp", timestamp);
				timestamp = decoder->timestamp;
				bad = true;
			}
		}
		if (decoder->vm_time_correlation &&
		    (bad || !intel_pt_time_in_range(decoder, timestamp)) &&
		    intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
			p_log("Timestamp out of range");
		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);
	intel_pt_set_nr(decoder);
	decoder->timestamp_insn_cnt = 0;
	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
	decoder->state.from_ip = decoder->ip;
	decoder->ip = 0;
	decoder->pge = false;
	intel_pt_clear_fup_event(decoder);
	decoder->overflow = true;
	return -EOVERFLOW;
}

static inline void intel_pt_mtc_cyc_cnt_pge(struct intel_pt_decoder *decoder)
{
	if (decoder->have_cyc)
		return;

	decoder->cyc_cnt_timestamp = decoder->timestamp;
	decoder->base_cyc_cnt = decoder->tot_cyc_cnt;
}

static inline void intel_pt_mtc_cyc_cnt_cbr(struct intel_pt_decoder *decoder)
{
	decoder->tsc_to_cyc = decoder->cbr / decoder->max_non_turbo_ratio_fp;

	if (decoder->pge)
		intel_pt_mtc_cyc_cnt_pge(decoder);
}

static inline void intel_pt_mtc_cyc_cnt_upd(struct intel_pt_decoder *decoder)
{
	uint64_t tot_cyc_cnt, tsc_delta;

	if (decoder->have_cyc)
		return;

	decoder->sample_cyc = true;

	if (!decoder->pge || decoder->timestamp <= decoder->cyc_cnt_timestamp)
		return;

	tsc_delta = decoder->timestamp - decoder->cyc_cnt_timestamp;
	tot_cyc_cnt = tsc_delta * decoder->tsc_to_cyc + decoder->base_cyc_cnt;

	if (tot_cyc_cnt > decoder->tot_cyc_cnt)
		decoder->tot_cyc_cnt = tot_cyc_cnt;
}

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;

	if (decoder->pge && !decoder->in_psb)
		intel_pt_mtc_cyc_cnt_pge(decoder);
	else
		intel_pt_mtc_cyc_cnt_upd(decoder);

	decoder->last_mtc = (ctc >> decoder->mtc_shift) & 0xff;
	decoder->last_ctc = ctc - ctc_rem;
	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;

	intel_pt_mtc_cyc_cnt_upd(decoder);

	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);
	}

	intel_pt_log_to("Setting timestamp", decoder->timestamp);
}

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;
	decoder->cyc_ref_timestamp = decoder->timestamp;
	decoder->cycle_cnt = 0;

	intel_pt_mtc_cyc_cnt_cbr(decoder);
}

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->pge)
		decoder->tot_cyc_cnt += decoder->packet.payload;
	decoder->sample_cyc = true;

	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;

	intel_pt_log_to("Setting timestamp", decoder->timestamp);
}

static void intel_pt_bbp(struct intel_pt_decoder *decoder)
{
	if (decoder->prev_pkt_ctx == INTEL_PT_NO_CTX) {
		memset(decoder->state.items.mask, 0, sizeof(decoder->state.items.mask));
		decoder->state.items.is_32_bit = false;
	}
	decoder->blk_type = decoder->packet.payload;
	decoder->blk_type_pos = intel_pt_blk_type_pos(decoder->blk_type);
	if (decoder->blk_type == INTEL_PT_GP_REGS)
		decoder->state.items.is_32_bit = decoder->packet.count;
	if (decoder->blk_type_pos < 0) {
		intel_pt_log("WARNING: Unknown block type %u\n",
			     decoder->blk_type);
	} else if (decoder->state.items.mask[decoder->blk_type_pos]) {
		intel_pt_log("WARNING: Duplicate block type %u\n",
			     decoder->blk_type);
	}
}

static void intel_pt_bip(struct intel_pt_decoder *decoder)
{
	uint32_t id = decoder->packet.count;
	uint32_t bit = 1 << id;
	int pos = decoder->blk_type_pos;

	if (pos < 0 || id >= INTEL_PT_BLK_ITEM_ID_CNT) {
		intel_pt_log("WARNING: Unknown block item %u type %d\n",
			     id, decoder->blk_type);
		return;
	}

	if (decoder->state.items.mask[pos] & bit) {
		intel_pt_log("WARNING: Duplicate block item %u type %d\n",
			     id, decoder->blk_type);
	}

	decoder->state.items.mask[pos] |= bit;
	decoder->state.items.val[pos][id] = decoder->packet.payload;
}

/* Walk PSB+ packets when already in sync. */
static int intel_pt_walk_psbend(struct intel_pt_decoder *decoder)
{
	int err;

	decoder->in_psb = true;

	while (1) {
		err = intel_pt_get_next_packet(decoder);
		if (err)
			goto out;

		switch (decoder->packet.type) {
		case INTEL_PT_PSBEND:
			err = 0;
			goto out;

		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:
		case INTEL_PT_BBP:
		case INTEL_PT_BIP:
		case INTEL_PT_BEP:
		case INTEL_PT_BEP_IP:
		case INTEL_PT_CFE:
		case INTEL_PT_CFE_IP:
		case INTEL_PT_EVD:
			decoder->have_tma = false;
			intel_pt_log("ERROR: Unexpected packet\n");
			err = -EAGAIN;
			goto out;

		case INTEL_PT_OVF:
			err = intel_pt_overflow(decoder);
			goto out;

		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:
			intel_pt_mode_exec_status(decoder);
			break;

		case INTEL_PT_PIP:
			intel_pt_set_pip(decoder);
			break;

		case INTEL_PT_FUP:
			decoder->pge = true;
			if (decoder->packet.count) {
				intel_pt_set_last_ip(decoder);
				decoder->psb_ip = decoder->last_ip;
			}
			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:
			intel_pt_calc_cyc_timestamp(decoder);
			break;

		case INTEL_PT_VMCS:
		case INTEL_PT_MNT:
		case INTEL_PT_PAD:
		default:
			break;
		}
	}
out:
	decoder->in_psb = false;

	return err;
}

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:
		case INTEL_PT_BBP:
		case INTEL_PT_BIP:
		case INTEL_PT_BEP:
		case INTEL_PT_BEP_IP:
		case INTEL_PT_CFE:
		case INTEL_PT_CFE_IP:
		case INTEL_PT_EVD:
			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;
			if (decoder->packet.count == 0) {
				decoder->state.to_ip = 0;
			} else {
				intel_pt_set_ip(decoder);
				decoder->state.to_ip = decoder->ip;
			}
			decoder->pge = false;
			decoder->continuous_period = false;
			decoder->state.type |= INTEL_PT_TRACE_END;
			intel_pt_update_nr(decoder);
			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;
			}
			decoder->state.type |= INTEL_PT_TRACE_BEGIN;
			intel_pt_mtc_cyc_cnt_pge(decoder);
			intel_pt_set_nr(decoder);
			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;
			}
			intel_pt_update_nr(decoder);
			intel_pt_sample_iflag_chg(decoder);
			return 0;

		case INTEL_PT_PIP:
			intel_pt_update_pip(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:
			intel_pt_calc_cyc_timestamp(decoder);
			break;

		case INTEL_PT_MODE_EXEC:
			intel_pt_mode_exec(decoder);
			break;

		case INTEL_PT_VMCS:
		case INTEL_PT_MNT:
		case INTEL_PT_PAD:
			break;

		default:
			return intel_pt_bug(decoder);
		}
	}
}

static int intel_pt_resample(struct intel_pt_decoder *decoder)
{
	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
	decoder->state.type = INTEL_PT_INSTRUCTION;
	decoder->state.from_ip = decoder->ip;
	decoder->state.to_ip = 0;
	return 0;
}

struct intel_pt_vm_tsc_info {
	struct intel_pt_pkt pip_packet;
	struct intel_pt_pkt vmcs_packet;
	struct intel_pt_pkt tma_packet;
	bool tsc, pip, vmcs, tma, psbend;
	uint64_t ctc_delta;
	uint64_t last_ctc;
	int max_lookahead;
};

/* Lookahead and get the PIP, VMCS and TMA packets from PSB+ */
static int intel_pt_vm_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
{
	struct intel_pt_vm_tsc_info *data = pkt_info->data;

	switch (pkt_info->packet.type) {
	case INTEL_PT_PAD:
	case INTEL_PT_MNT:
	case INTEL_PT_MODE_EXEC:
	case INTEL_PT_MODE_TSX:
	case INTEL_PT_MTC:
	case INTEL_PT_FUP:
	case INTEL_PT_CYC:
	case INTEL_PT_CBR:
		break;

	case INTEL_PT_TSC:
		data->tsc = true;
		break;

	case INTEL_PT_TMA:
		data->tma_packet = pkt_info->packet;
		data->tma = true;
		break;

	case INTEL_PT_PIP:
		data->pip_packet = pkt_info->packet;
		data->pip = true;
		break;

	case INTEL_PT_VMCS:
		data->vmcs_packet = pkt_info->packet;
		data->vmcs = true;
		break;

	case INTEL_PT_PSBEND:
		data->psbend = true;
		return 1;

	case INTEL_PT_TIP_PGE:
	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:
	case INTEL_PT_BBP:
	case INTEL_PT_BIP:
	case INTEL_PT_BEP:
	case INTEL_PT_BEP_IP:
	case INTEL_PT_OVF:
	case INTEL_PT_BAD:
	case INTEL_PT_TNT:
	case INTEL_PT_TIP_PGD:
	case INTEL_PT_TIP:
	case INTEL_PT_PSB:
	case INTEL_PT_TRACESTOP:
	case INTEL_PT_CFE:
	case INTEL_PT_CFE_IP:
	case INTEL_PT_EVD:
	default:
		return 1;
	}

	return 0;
}

struct intel_pt_ovf_fup_info {
	int max_lookahead;
	bool found;
};

/* Lookahead to detect a FUP packet after OVF */
static int intel_pt_ovf_fup_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
{
	struct intel_pt_ovf_fup_info *data = pkt_info->data;

	if (pkt_info->packet.type == INTEL_PT_CYC ||
	    pkt_info->packet.type == INTEL_PT_MTC ||
	    pkt_info->packet.type == INTEL_PT_TSC)
		return !--(data->max_lookahead);
	data->found = pkt_info->packet.type == INTEL_PT_FUP;
	return 1;
}

static bool intel_pt_ovf_fup_lookahead(struct intel_pt_decoder *decoder)
{
	struct intel_pt_ovf_fup_info data = {
		.max_lookahead = 16,
		.found = false,
	};

	intel_pt_pkt_lookahead(decoder, intel_pt_ovf_fup_lookahead_cb, &data);
	return data.found;
}

/* Lookahead and get the TMA packet after TSC */
static int intel_pt_tma_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
{
	struct intel_pt_vm_tsc_info *data = pkt_info->data;

	if (pkt_info->packet.type == INTEL_PT_CYC ||
	    pkt_info->packet.type == INTEL_PT_MTC)
		return !--(data->max_lookahead);

	if (pkt_info->packet.type == INTEL_PT_TMA) {
		data->tma_packet = pkt_info->packet;
		data->tma = true;
	}
	return 1;
}

static uint64_t intel_pt_ctc_to_tsc(struct intel_pt_decoder *decoder, uint64_t ctc)
{
	if (decoder->tsc_ctc_mult)
		return ctc * decoder->tsc_ctc_mult;
	else
		return multdiv(ctc, decoder->tsc_ctc_ratio_n, decoder->tsc_ctc_ratio_d);
}

static uint64_t intel_pt_calc_expected_tsc(struct intel_pt_decoder *decoder,
					   uint32_t ctc,
					   uint32_t fc,
					   uint64_t last_ctc_timestamp,
					   uint64_t ctc_delta,
					   uint32_t last_ctc)
{
	/* Number of CTC ticks from last_ctc_timestamp to last_mtc */
	uint64_t last_mtc_ctc = last_ctc + ctc_delta;
	/*
	 * Number of CTC ticks from there until current TMA packet. We would
	 * expect last_mtc_ctc to be before ctc, but the TSC packet can slip
	 * past an MTC, so a sign-extended value is used.
	 */
	uint64_t delta = (int16_t)((uint16_t)ctc - (uint16_t)last_mtc_ctc);
	/* Total CTC ticks from last_ctc_timestamp to current TMA packet */
	uint64_t new_ctc_delta = ctc_delta + delta;
	uint64_t expected_tsc;

	/*
	 * Convert CTC ticks to TSC ticks, add the starting point
	 * (last_ctc_timestamp) and the fast counter from the TMA packet.
	 */
	expected_tsc = last_ctc_timestamp + intel_pt_ctc_to_tsc(decoder, new_ctc_delta) + fc;

	if (intel_pt_enable_logging) {
		intel_pt_log_x64(last_mtc_ctc);
		intel_pt_log_x32(last_ctc);
		intel_pt_log_x64(ctc_delta);
		intel_pt_log_x64(delta);
		intel_pt_log_x32(ctc);
		intel_pt_log_x64(new_ctc_delta);
		intel_pt_log_x64(last_ctc_timestamp);
		intel_pt_log_x32(fc);
		intel_pt_log_x64(intel_pt_ctc_to_tsc(decoder, new_ctc_delta));
		intel_pt_log_x64(expected_tsc);
	}

	return expected_tsc;
}

static uint64_t intel_pt_expected_tsc(struct intel_pt_decoder *decoder,
				      struct intel_pt_vm_tsc_info *data)
{
	uint32_t ctc = data->tma_packet.payload;
	uint32_t fc = data->tma_packet.count;

	return intel_pt_calc_expected_tsc(decoder, ctc, fc,
					  decoder->ctc_timestamp,
					  data->ctc_delta, data->last_ctc);
}

static void intel_pt_translate_vm_tsc(struct intel_pt_decoder *decoder,
				      struct intel_pt_vmcs_info *vmcs_info)
{
	uint64_t payload = decoder->packet.payload;

	/* VMX adds the TSC Offset, so subtract to get host TSC */
	decoder->packet.payload -= vmcs_info->tsc_offset;
	/* TSC packet has only 7 bytes */
	decoder->packet.payload &= SEVEN_BYTES;

	/*
	 * The buffer is mmapped from the data file, so this also updates the
	 * data file.
	 */
	if (!decoder->vm_tm_corr_dry_run)
		memcpy((void *)decoder->buf + 1, &decoder->packet.payload, 7);

	intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
		     "    VMCS %#" PRIx64 "    TSC Offset %#" PRIx64 "\n",
		     payload, decoder->packet.payload, vmcs_info->vmcs,
		     vmcs_info->tsc_offset);
}

static void intel_pt_translate_vm_tsc_offset(struct intel_pt_decoder *decoder,
					     uint64_t tsc_offset)
{
	struct intel_pt_vmcs_info vmcs_info = {
		.vmcs = NO_VMCS,
		.tsc_offset = tsc_offset
	};

	intel_pt_translate_vm_tsc(decoder, &vmcs_info);
}

static inline bool in_vm(uint64_t pip_payload)
{
	return pip_payload & 1;
}

static inline bool pip_in_vm(struct intel_pt_pkt *pip_packet)
{
	return pip_packet->payload & 1;
}

static void intel_pt_print_vmcs_info(struct intel_pt_vmcs_info *vmcs_info)
{
	p_log("VMCS: %#" PRIx64 "  TSC Offset %#" PRIx64,
	      vmcs_info->vmcs, vmcs_info->tsc_offset);
}

static void intel_pt_vm_tm_corr_psb(struct intel_pt_decoder *decoder,
				    struct intel_pt_vm_tsc_info *data)
{
	memset(data, 0, sizeof(*data));
	data->ctc_delta = decoder->ctc_delta;
	data->last_ctc = decoder->last_ctc;
	intel_pt_pkt_lookahead(decoder, intel_pt_vm_psb_lookahead_cb, data);
	if (data->tsc && !data->psbend)
		p_log("ERROR: PSB without PSBEND");
	decoder->in_psb = data->psbend;
}

static void intel_pt_vm_tm_corr_first_tsc(struct intel_pt_decoder *decoder,
					  struct intel_pt_vm_tsc_info *data,
					  struct intel_pt_vmcs_info *vmcs_info,
					  uint64_t host_tsc)
{
	if (!decoder->in_psb) {
		/* Can't happen */
		p_log("ERROR: First TSC is not in PSB+");
	}

	if (data->pip) {
		if (pip_in_vm(&data->pip_packet)) { /* Guest */
			if (vmcs_info && vmcs_info->tsc_offset) {
				intel_pt_translate_vm_tsc(decoder, vmcs_info);
				decoder->vm_tm_corr_reliable = true;
			} else {
				p_log("ERROR: First TSC, unknown TSC Offset");
			}
		} else { /* Host */
			decoder->vm_tm_corr_reliable = true;
		}
	} else { /* Host or Guest */
		decoder->vm_tm_corr_reliable = false;
		if (intel_pt_time_in_range(decoder, host_tsc)) {
			/* Assume Host */
		} else {
			/* Assume Guest */
			if (vmcs_info && vmcs_info->tsc_offset)
				intel_pt_translate_vm_tsc(decoder, vmcs_info);
			else
				p_log("ERROR: First TSC, no PIP, unknown TSC Offset");
		}
	}
}

static void intel_pt_vm_tm_corr_tsc(struct intel_pt_decoder *decoder,
				    struct intel_pt_vm_tsc_info *data)
{
	struct intel_pt_vmcs_info *vmcs_info;
	uint64_t tsc_offset = 0;
	uint64_t vmcs;
	bool reliable = true;
	uint64_t expected_tsc;
	uint64_t host_tsc;
	uint64_t ref_timestamp;

	bool assign = false;
	bool assign_reliable = false;

	/* Already have 'data' for the in_psb case */
	if (!decoder->in_psb) {
		memset(data, 0, sizeof(*data));
		data->ctc_delta = decoder->ctc_delta;
		data->last_ctc = decoder->last_ctc;
		data->max_lookahead = 16;
		intel_pt_pkt_lookahead(decoder, intel_pt_tma_lookahead_cb, data);
		if (decoder->pge) {
			data->pip = true;
			data->pip_packet.payload = decoder->pip_payload;
		}
	}

	/* Calculations depend on having TMA packets */
	if (!data->tma) {
		p_log("ERROR: TSC without TMA");
		return;
	}

	vmcs = data->vmcs ? data->vmcs_packet.payload : decoder->vmcs;
	if (vmcs == NO_VMCS)
		vmcs = 0;

	vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);

	ref_timestamp = decoder->timestamp ? decoder->timestamp : decoder->buf_timestamp;
	host_tsc = intel_pt_8b_tsc(decoder->packet.payload, ref_timestamp);

	if (!decoder->ctc_timestamp) {
		intel_pt_vm_tm_corr_first_tsc(decoder, data, vmcs_info, host_tsc);
		return;
	}

	expected_tsc = intel_pt_expected_tsc(decoder, data);

	tsc_offset = host_tsc - expected_tsc;

	/* Determine if TSC is from Host or Guest */
	if (data->pip) {
		if (pip_in_vm(&data->pip_packet)) { /* Guest */
			if (!vmcs_info) {
				/* PIP NR=1 without VMCS cannot happen */
				p_log("ERROR: Missing VMCS");
				intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
				decoder->vm_tm_corr_reliable = false;
				return;
			}
		} else { /* Host */
			decoder->last_reliable_timestamp = host_tsc;
			decoder->vm_tm_corr_reliable = true;
			return;
		}
	} else { /* Host or Guest */
		reliable = false; /* Host/Guest is a guess, so not reliable */
		if (decoder->in_psb) {
			if (!tsc_offset)
				return; /* Zero TSC Offset, assume Host */
			/*
			 * TSC packet has only 7 bytes of TSC. We have no
			 * information about the Guest's 8th byte, but it
			 * doesn't matter because we only need 7 bytes.
			 * Here, since the 8th byte is unreliable and
			 * irrelevant, compare only 7 byes.
			 */
			if (vmcs_info &&
			    (tsc_offset & SEVEN_BYTES) ==
			    (vmcs_info->tsc_offset & SEVEN_BYTES)) {
				/* Same TSC Offset as last VMCS, assume Guest */
				goto guest;
			}
		}
		/*
		 * Check if the host_tsc is within the expected range.
		 * Note, we could narrow the range more by looking ahead for
		 * the next host TSC in the same buffer, but we don't bother to
		 * do that because this is probably good enough.
		 */
		if (host_tsc >= expected_tsc && intel_pt_time_in_range(decoder, host_tsc)) {
			/* Within expected range for Host TSC, assume Host */
			decoder->vm_tm_corr_reliable = false;
			return;
		}
	}

guest: /* Assuming Guest */

	/* Determine whether to assign TSC Offset */
	if (vmcs_info && vmcs_info->vmcs) {
		if (vmcs_info->tsc_offset && vmcs_info->reliable) {
			assign = false;
		} else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_reliable &&
			   decoder->vm_tm_corr_continuous && decoder->vm_tm_corr_same_buf) {
			/* Continuous tracing, TSC in a PSB is not a time loss */
			assign = true;
			assign_reliable = true;
		} else if (decoder->in_psb && data->pip && decoder->vm_tm_corr_same_buf) {
			/*
			 * Unlikely to be a time loss TSC in a PSB which is not
			 * at the start of a buffer.
			 */
			assign = true;
			assign_reliable = false;
		}
	}

	/* Record VMCS TSC Offset */
	if (assign && (vmcs_info->tsc_offset != tsc_offset ||
		       vmcs_info->reliable != assign_reliable)) {
		bool print = vmcs_info->tsc_offset != tsc_offset;

		vmcs_info->tsc_offset = tsc_offset;
		vmcs_info->reliable = assign_reliable;
		if (print)
			intel_pt_print_vmcs_info(vmcs_info);
	}

	/* Determine what TSC Offset to use */
	if (vmcs_info && vmcs_info->tsc_offset) {
		if (!vmcs_info->reliable)
			reliable = false;
		intel_pt_translate_vm_tsc(decoder, vmcs_info);
	} else {
		reliable = false;
		if (vmcs_info) {
			if (!vmcs_info->error_printed) {
				p_log("ERROR: Unknown TSC Offset for VMCS %#" PRIx64,
				      vmcs_info->vmcs);
				vmcs_info->error_printed = true;
			}
		} else {
			if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
				p_log("ERROR: Unknown VMCS");
		}
		intel_pt_translate_vm_tsc_offset(decoder, tsc_offset);
	}

	decoder->vm_tm_corr_reliable = reliable;
}

static void intel_pt_vm_tm_corr_pebs_tsc(struct intel_pt_decoder *decoder)
{
	uint64_t host_tsc = decoder->packet.payload;
	uint64_t guest_tsc = decoder->packet.payload;
	struct intel_pt_vmcs_info *vmcs_info;
	uint64_t vmcs;

	vmcs = decoder->vmcs;
	if (vmcs == NO_VMCS)
		vmcs = 0;

	vmcs_info = decoder->findnew_vmcs_info(decoder->data, vmcs);

	if (decoder->pge) {
		if (in_vm(decoder->pip_payload)) { /* Guest */
			if (!vmcs_info) {
				/* PIP NR=1 without VMCS cannot happen */
				p_log("ERROR: Missing VMCS");
			}
		} else { /* Host */
			return;
		}
	} else { /* Host or Guest */
		if (intel_pt_time_in_range(decoder, host_tsc)) {
			/* Within expected range for Host TSC, assume Host */
			return;
		}
	}

	if (vmcs_info) {
		/* Translate Guest TSC to Host TSC */
		host_tsc = ((guest_tsc & SEVEN_BYTES) - vmcs_info->tsc_offset) & SEVEN_BYTES;
		host_tsc = intel_pt_8b_tsc(host_tsc, decoder->timestamp);
		intel_pt_log("Translated VM TSC %#" PRIx64 " -> %#" PRIx64
			     "    VMCS %#" PRIx64 "    TSC Offset %#" PRIx64 "\n",
			     guest_tsc, host_tsc, vmcs_info->vmcs,
			     vmcs_info->tsc_offset);
		if (!intel_pt_time_in_range(decoder, host_tsc) &&
		    intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_ERANGE))
			p_log("Timestamp out of range");
	} else {
		if (intel_pt_print_once(decoder, INTEL_PT_PRT_ONCE_UNK_VMCS))
			p_log("ERROR: Unknown VMCS");
		host_tsc = decoder->timestamp;
	}

	decoder->packet.payload = host_tsc;

	if (!decoder->vm_tm_corr_dry_run)
		memcpy((void *)decoder->buf + 1, &host_tsc, 8);
}

static int intel_pt_vm_time_correlation(struct intel_pt_decoder *decoder)
{
	struct intel_pt_vm_tsc_info data = { .psbend = false };
	bool pge;
	int err;

	if (decoder->in_psb)
		intel_pt_vm_tm_corr_psb(decoder, &data);

	while (1) {
		err = intel_pt_get_next_packet(decoder);
		if (err == -ENOLINK)
			continue;
		if (err)
			break;

		switch (decoder->packet.type) {
		case INTEL_PT_TIP_PGD:
			decoder->pge = false;
			decoder->vm_tm_corr_continuous = false;
			break;

		case INTEL_PT_TNT:
		case INTEL_PT_TIP:
		case INTEL_PT_TIP_PGE:
			decoder->pge = true;
			break;

		case INTEL_PT_OVF:
			decoder->in_psb = false;
			pge = decoder->pge;
			decoder->pge = intel_pt_ovf_fup_lookahead(decoder);
			if (pge != decoder->pge)
				intel_pt_log("Surprising PGE change in OVF!");
			if (!decoder->pge)
				decoder->vm_tm_corr_continuous = false;
			break;

		case INTEL_PT_FUP:
			if (decoder->in_psb)
				decoder->pge = true;
			break;

		case INTEL_PT_TRACESTOP:
			decoder->pge = false;
			decoder->vm_tm_corr_continuous = false;
			decoder->have_tma = false;
			break;

		case INTEL_PT_PSB:
			intel_pt_vm_tm_corr_psb(decoder, &data);
			break;

		case INTEL_PT_PIP:
			decoder->pip_payload = decoder->packet.payload;
			break;

		case INTEL_PT_MTC:
			intel_pt_calc_mtc_timestamp(decoder);
			break;

		case INTEL_PT_TSC:
			intel_pt_vm_tm_corr_tsc(decoder, &data);
			intel_pt_calc_tsc_timestamp(decoder);
			decoder->vm_tm_corr_same_buf = true;
			decoder->vm_tm_corr_continuous = decoder->pge;
			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_PSBEND:
			decoder->in_psb = false;
			data.psbend = false;
			break;

		case INTEL_PT_VMCS:
			if (decoder->packet.payload != NO_VMCS)
				decoder->vmcs = decoder->packet.payload;
			break;

		case INTEL_PT_BBP:
			decoder->blk_type = decoder->packet.payload;
			break;

		case INTEL_PT_BIP:
			if (decoder->blk_type == INTEL_PT_PEBS_BASIC &&
			    decoder->packet.count == 2)
				intel_pt_vm_tm_corr_pebs_tsc(decoder);
			break;

		case INTEL_PT_BEP:
		case INTEL_PT_BEP_IP:
			decoder->blk_type = 0;
			break;

		case INTEL_PT_CFE:
		case INTEL_PT_CFE_IP:
		case INTEL_PT_EVD:
		case INTEL_PT_MODE_EXEC:
		case INTEL_PT_MODE_TSX:
		case INTEL_PT_MNT:
		case INTEL_PT_PAD:
		case INTEL_PT_PTWRITE_IP:
		case INTEL_PT_PTWRITE:
		case INTEL_PT_MWAIT:
		case INTEL_PT_PWRE:
		case INTEL_PT_EXSTOP_IP:
		case INTEL_PT_EXSTOP:
		case INTEL_PT_PWRX:
		case INTEL_PT_BAD: /* Does not happen */
		default:
			break;
		}
	}

	return err;
}

#define HOP_PROCESS	0
#define HOP_IGNORE	1
#define HOP_RETURN	2
#define HOP_AGAIN	3

static int intel_pt_scan_for_psb(struct intel_pt_decoder *decoder);

/* Hop mode: Ignore TNT, do not walk code, but get ip from FUPs and TIPs */
static int intel_pt_hop_trace(struct intel_pt_decoder *decoder, bool *no_tip, int *err)
{
	*err = 0;

	/* Leap from PSB to PSB, getting ip from FUP within PSB+ */
	if (decoder->leap && !decoder->in_psb && decoder->packet.type != INTEL_PT_PSB) {
		*err = intel_pt_scan_for_psb(decoder);
		if (*err)
			return HOP_RETURN;
	}

	switch (decoder->packet.type) {
	case INTEL_PT_TNT:
		return HOP_IGNORE;

	case INTEL_PT_TIP_PGD:
		decoder->pge = false;
		if (!decoder->packet.count) {
			intel_pt_set_nr(decoder);
			return HOP_IGNORE;
		}
		intel_pt_set_ip(decoder);
		decoder->state.type |= INTEL_PT_TRACE_END;
		decoder->state.from_ip = 0;
		decoder->state.to_ip = decoder->ip;
		intel_pt_update_nr(decoder);
		return HOP_RETURN;

	case INTEL_PT_TIP:
		if (!decoder->packet.count) {
			intel_pt_set_nr(decoder);
			return HOP_IGNORE;
		}
		intel_pt_set_ip(decoder);
		decoder->state.type = INTEL_PT_INSTRUCTION;
		decoder->state.from_ip = decoder->ip;
		decoder->state.to_ip = 0;
		intel_pt_update_nr(decoder);
		intel_pt_sample_iflag_chg(decoder);
		return HOP_RETURN;

	case INTEL_PT_FUP:
		if (!decoder->packet.count)
			return HOP_IGNORE;
		intel_pt_set_ip(decoder);
		if (decoder->set_fup_mwait || decoder->set_fup_pwre)
			*no_tip = true;
		if (!decoder->branch_enable || !decoder->pge)
			*no_tip = true;
		if (*no_tip) {
			decoder->state.type = INTEL_PT_INSTRUCTION;
			decoder->state.from_ip = decoder->ip;
			decoder->state.to_ip = 0;
			intel_pt_fup_event(decoder, *no_tip);
			return HOP_RETURN;
		}
		intel_pt_fup_event(decoder, *no_tip);
		decoder->state.type |= INTEL_PT_INSTRUCTION | INTEL_PT_BRANCH;
		*err = intel_pt_walk_fup_tip(decoder);
		if (!*err && decoder->state.to_ip)
			decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
		return HOP_RETURN;

	case INTEL_PT_PSB:
		decoder->state.psb_offset = decoder->pos;
		decoder->psb_ip = 0;
		decoder->last_ip = 0;
		decoder->have_last_ip = true;
		*err = intel_pt_walk_psbend(decoder);
		if (*err == -EAGAIN)
			return HOP_AGAIN;
		if (*err)
			return HOP_RETURN;
		decoder->state.type = INTEL_PT_PSB_EVT;
		if (decoder->psb_ip) {
			decoder->state.type |= INTEL_PT_INSTRUCTION;
			decoder->ip = decoder->psb_ip;
		}
		decoder->state.from_ip = decoder->psb_ip;
		decoder->state.to_ip = 0;
		return HOP_RETURN;

	case INTEL_PT_BAD:
	case INTEL_PT_PAD:
	case INTEL_PT_TIP_PGE:
	case INTEL_PT_TSC:
	case INTEL_PT_TMA:
	case INTEL_PT_MODE_EXEC:
	case INTEL_PT_MODE_TSX:
	case INTEL_PT_MTC:
	case INTEL_PT_CYC:
	case INTEL_PT_VMCS:
	case INTEL_PT_PSBEND:
	case INTEL_PT_CBR:
	case INTEL_PT_TRACESTOP:
	case INTEL_PT_PIP:
	case INTEL_PT_OVF:
	case INTEL_PT_MNT:
	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:
	case INTEL_PT_BBP:
	case INTEL_PT_BIP:
	case INTEL_PT_BEP:
	case INTEL_PT_BEP_IP:
	case INTEL_PT_CFE:
	case INTEL_PT_CFE_IP:
	case INTEL_PT_EVD:
	default:
		return HOP_PROCESS;
	}
}

struct intel_pt_psb_info {
	struct intel_pt_pkt fup_packet;
	bool fup;
	int after_psbend;
};

/* Lookahead and get the FUP packet from PSB+ */
static int intel_pt_psb_lookahead_cb(struct intel_pt_pkt_info *pkt_info)
{
	struct intel_pt_psb_info *data = pkt_info->data;

	switch (pkt_info->packet.type) {
	case INTEL_PT_PAD:
	case INTEL_PT_MNT:
	case INTEL_PT_TSC:
	case INTEL_PT_TMA:
	case INTEL_PT_MODE_EXEC:
	case INTEL_PT_MODE_TSX:
	case INTEL_PT_MTC:
	case INTEL_PT_CYC:
	case INTEL_PT_VMCS:
	case INTEL_PT_CBR:
	case INTEL_PT_PIP:
		if (data->after_psbend) {
			data->after_psbend -= 1;
			if (!data->after_psbend)
				return 1;
		}
		break;

	case INTEL_PT_FUP:
		if (data->after_psbend)
			return 1;
		if (data->fup || pkt_info->packet.count == 0)
			return 1;
		data->fup_packet = pkt_info->packet;
		data->fup = true;
		break;

	case INTEL_PT_PSBEND:
		if (!data->fup)
			return 1;
		/* Keep going to check for a TIP.PGE */
		data->after_psbend = 6;
		break;

	case INTEL_PT_TIP_PGE:
		/* Ignore FUP in PSB+ if followed by TIP.PGE */
		if (data->after_psbend)
			data->fup = false;
		return 1;

	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:
	case INTEL_PT_BBP:
	case INTEL_PT_BIP:
	case INTEL_PT_BEP:
	case INTEL_PT_BEP_IP:
	case INTEL_PT_CFE:
	case INTEL_PT_CFE_IP:
	case INTEL_PT_EVD:
		if (data->after_psbend) {
			data->after_psbend -= 1;
			if (!data->after_psbend)
				return 1;
			break;
		}
		return 1;

	case INTEL_PT_OVF:
	case INTEL_PT_BAD:
	case INTEL_PT_TNT:
	case INTEL_PT_TIP_PGD:
	case INTEL_PT_TIP:
	case INTEL_PT_PSB:
	case INTEL_PT_TRACESTOP:
	default:
		return 1;
	}

	return 0;
}

static int intel_pt_psb(struct intel_pt_decoder *decoder)
{
	int err;

	decoder->last_ip = 0;
	decoder->psb_ip = 0;
	decoder->have_last_ip = true;
	intel_pt_clear_stack(&decoder->stack);
	err = intel_pt_walk_psbend(decoder);
	if (err)
		return err;
	decoder->state.type = INTEL_PT_PSB_EVT;
	decoder->state.from_ip = decoder->psb_ip;
	decoder->state.to_ip = 0;
	return 0;
}

static int intel_pt_fup_in_psb(struct intel_pt_decoder *decoder)
{
	int err;

	if (decoder->ip != decoder->last_ip) {
		err = intel_pt_walk_fup(decoder);
		if (!err || err != -EAGAIN)
			return err;
	}

	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
	err = intel_pt_psb(decoder);
	if (err) {
		decoder->pkt_state = INTEL_PT_STATE_ERR3;
		return -ENOENT;
	}

	return 0;
}

static bool intel_pt_psb_with_fup(struct intel_pt_decoder *decoder, int *err)
{
	struct intel_pt_psb_info data = { .fup = false };

	if (!decoder->branch_enable)
		return false;

	intel_pt_pkt_lookahead(decoder, intel_pt_psb_lookahead_cb, &data);
	if (!data.fup)
		return false;

	decoder->packet = data.fup_packet;
	intel_pt_set_last_ip(decoder);
	decoder->pkt_state = INTEL_PT_STATE_FUP_IN_PSB;

	*err = intel_pt_fup_in_psb(decoder);

	return true;
}

static int intel_pt_walk_trace(struct intel_pt_decoder *decoder)
{
	int last_packet_type = INTEL_PT_PAD;
	bool no_tip = false;
	int err;

	while (1) {
		err = intel_pt_get_next_packet(decoder);
		if (err)
			return err;
next:
		err = 0;
		if (decoder->cyc_threshold) {
			if (decoder->sample_cyc && last_packet_type != INTEL_PT_CYC)
				decoder->sample_cyc = false;
			last_packet_type = decoder->packet.type;
		}

		if (decoder->hop) {
			switch (intel_pt_hop_trace(decoder, &no_tip, &err)) {
			case HOP_IGNORE:
				continue;
			case HOP_RETURN:
				return err;
			case HOP_AGAIN:
				goto next;
			default:
				break;
			}
		}

		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;
			decoder->overflow = false;
			intel_pt_mtc_cyc_cnt_pge(decoder);
			intel_pt_set_nr(decoder);
			if (decoder->packet.count == 0) {
				intel_pt_log_at("Skipping zero TIP.PGE",
						decoder->pos);
				break;
			}
			intel_pt_sample_iflag_chg(decoder);
			intel_pt_set_ip(decoder);
			decoder->state.from_ip = 0;
			decoder->state.to_ip = decoder->ip;
			decoder->state.type |= INTEL_PT_TRACE_BEGIN;
			/*
			 * In hop mode, resample to get the to_ip as an
			 * "instruction" sample.
			 */
			if (decoder->hop)
				decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
			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->pge) {
				decoder->ip = decoder->last_ip;
				if (intel_pt_fup_event(decoder, no_tip))
					return 0;
				no_tip = false;
				break;
			}
			if (decoder->set_fup_mwait)
				no_tip = true;
			if (no_tip)
				decoder->pkt_state = INTEL_PT_STATE_FUP_NO_TIP;
			else
				decoder->pkt_state = INTEL_PT_STATE_FUP;
			err = intel_pt_walk_fup(decoder);
			if (err != -EAGAIN)
				return err;
			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->state.psb_offset = decoder->pos;
			decoder->psb_ip = 0;
			if (intel_pt_psb_with_fup(decoder, &err))
				return err;
			err = intel_pt_psb(decoder);
			if (err == -EAGAIN)
				goto next;
			return err;

		case INTEL_PT_PIP:
			intel_pt_update_pip(decoder);
			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->cbr != decoder->cbr_seen) {
				decoder->state.type = 0;
				return 0;
			}
			break;

		case INTEL_PT_MODE_EXEC:
			intel_pt_mode_exec(decoder);
			err = intel_pt_get_next_packet(decoder);
			if (err)
				return err;
			if (decoder->packet.type == INTEL_PT_FUP) {
				decoder->set_fup_mode_exec = true;
				no_tip = true;
			}
			goto next;

		case INTEL_PT_MODE_TSX:
			/* MODE_TSX need not be followed by FUP */
			if (!decoder->pge || decoder->in_psb) {
				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;

		case INTEL_PT_BBP:
			intel_pt_bbp(decoder);
			break;

		case INTEL_PT_BIP:
			intel_pt_bip(decoder);
			break;

		case INTEL_PT_BEP:
			decoder->state.type = INTEL_PT_BLK_ITEMS;
			decoder->state.from_ip = decoder->ip;
			decoder->state.to_ip = 0;
			return 0;

		case INTEL_PT_BEP_IP:
			err = intel_pt_get_next_packet(decoder);
			if (err)
				return err;
			if (decoder->packet.type == INTEL_PT_FUP) {
				decoder->set_fup_bep = true;
				no_tip = true;
			} else {
				intel_pt_log_at("ERROR: Missing FUP after BEP",
						decoder->pos);
			}
			goto next;

		case INTEL_PT_CFE:
			decoder->fup_cfe_pkt = decoder->packet;
			decoder->set_fup_cfe = true;
			if (!decoder->pge) {
				intel_pt_fup_event(decoder, true);
				return 0;
			}
			break;

		case INTEL_PT_CFE_IP:
			decoder->fup_cfe_pkt = decoder->packet;
			err = intel_pt_get_next_packet(decoder);
			if (err)
				return err;
			if (decoder->packet.type == INTEL_PT_FUP) {
				decoder->set_fup_cfe_ip = true;
				no_tip = true;
			} else {
				intel_pt_log_at("ERROR: Missing FUP after CFE",
						decoder->pos);
			}
			goto next;

		case INTEL_PT_EVD:
			err = intel_pt_evd(decoder);
			if (err)
				return err;
			break;

		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;

	decoder->in_psb = true;

	while (1) {
		err = intel_pt_get_next_packet(decoder);
		if (err)
			goto out;

		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:
		case INTEL_PT_BBP:
		case INTEL_PT_BIP:
		case INTEL_PT_BEP:
		case INTEL_PT_BEP_IP:
		case INTEL_PT_CFE:
		case INTEL_PT_CFE_IP:
		case INTEL_PT_EVD:
			intel_pt_log("ERROR: Unexpected packet\n");
			err = -ENOENT;
			goto out;

		case INTEL_PT_FUP:
			decoder->pge = true;
			if (intel_pt_have_ip(decoder)) {
				uint64_t current_ip = decoder->ip;

				intel_pt_set_ip(decoder);
				decoder->psb_ip = decoder->ip;
				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:
			intel_pt_set_pip(decoder);
			break;

		case INTEL_PT_MODE_EXEC:
			intel_pt_mode_exec_status(decoder);
			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;
			err = -ENOENT;
			goto out;

		case INTEL_PT_BAD: /* Does not happen */
			err = intel_pt_bug(decoder);
			goto out;

		case INTEL_PT_OVF:
			err = intel_pt_overflow(decoder);
			goto out;

		case INTEL_PT_PSBEND:
			err = 0;
			goto out;

		case INTEL_PT_PSB:
		case INTEL_PT_VMCS:
		case INTEL_PT_MNT:
		case INTEL_PT_PAD:
		default:
			break;
		}
	}
out:
	decoder->in_psb = false;

	return err;
}

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;
			decoder->pge = false;
			if (intel_pt_have_ip(decoder))
				intel_pt_set_ip(decoder);
			if (!decoder->ip)
				break;
			decoder->state.type |= INTEL_PT_TRACE_END;
			return 0;

		case INTEL_PT_TIP_PGE:
			decoder->pge = true;
			intel_pt_mtc_cyc_cnt_pge(decoder);
			if (intel_pt_have_ip(decoder))
				intel_pt_set_ip(decoder);
			if (!decoder->ip)
				break;
			decoder->state.type |= INTEL_PT_TRACE_BEGIN;
			return 0;

		case INTEL_PT_TIP:
			decoder->pge = true;
			if (intel_pt_have_ip(decoder))
				intel_pt_set_ip(decoder);
			if (!decoder->ip)
				break;
			return 0;

		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:
			intel_pt_set_pip(decoder);
			break;

		case INTEL_PT_MODE_EXEC:
			intel_pt_mode_exec_status(decoder);
			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->state.psb_offset = decoder->pos;
			decoder->psb_ip = 0;
			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;
			decoder->state.type = INTEL_PT_PSB_EVT;
			decoder->state.from_ip = decoder->psb_ip;
			decoder->state.to_ip = 0;
			return 0;

		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:
		case INTEL_PT_BBP:
		case INTEL_PT_BIP:
		case INTEL_PT_BEP:
		case INTEL_PT_BEP_IP:
		case INTEL_PT_CFE:
		case INTEL_PT_CFE_IP:
		case INTEL_PT_EVD:
		default:
			break;
		}
	}
}

static int intel_pt_sync_ip(struct intel_pt_decoder *decoder)
{
	int err;

	intel_pt_clear_fup_event(decoder);
	decoder->overflow = false;

	if (!decoder->branch_enable) {
		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
		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 || ((decoder->state.type & INTEL_PT_PSB_EVT) && !decoder->ip))
		return err;

	/* In hop mode, resample to get the to_ip as an "instruction" sample */
	if (decoder->hop)
		decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
	else
		decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;

	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, false);
	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, false);
			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->psb_ip = 0;
	decoder->ip = 0;
	intel_pt_clear_stack(&decoder->stack);

	err = intel_pt_scan_for_psb(decoder);
	if (err)
		return err;

	if (decoder->vm_time_correlation) {
		decoder->in_psb = true;
		if (!decoder->timestamp)
			decoder->timestamp = 1;
		decoder->state.type = 0;
		decoder->pkt_state = INTEL_PT_STATE_VM_TIME_CORRELATION;
		return 0;
	}

	decoder->have_last_ip = true;
	decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;

	err = intel_pt_walk_psb(decoder);
	if (err)
		return err;

	decoder->state.type = INTEL_PT_PSB_EVT; /* Only PSB sample */
	decoder->state.from_ip = decoder->psb_ip;
	decoder->state.to_ip = 0;

	if (decoder->ip) {
		/*
		 * In hop mode, resample to get the PSB FUP ip as an
		 * "instruction" sample.
		 */
		if (decoder->hop)
			decoder->pkt_state = INTEL_PT_STATE_RESAMPLE;
		else
			decoder->pkt_state = INTEL_PT_STATE_IN_SYNC;
	}

	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:
		case INTEL_PT_STATE_TNT_CONT:
			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:
			err = intel_pt_walk_fup(decoder);
			if (err == -EAGAIN)
				err = intel_pt_walk_fup_tip(decoder);
			break;
		case INTEL_PT_STATE_FUP_NO_TIP:
			err = intel_pt_walk_fup(decoder);
			if (err == -EAGAIN)
				err = intel_pt_walk_trace(decoder);
			break;
		case INTEL_PT_STATE_FUP_IN_PSB:
			err = intel_pt_fup_in_psb(decoder);
			break;
		case INTEL_PT_STATE_RESAMPLE:
			err = intel_pt_resample(decoder);
			break;
		case INTEL_PT_STATE_VM_TIME_CORRELATION:
			err = intel_pt_vm_time_correlation(decoder);
			break;
		default:
			err = intel_pt_bug(decoder);
			break;
		}
	} while (err == -ENOLINK);

	if (err) {
		decoder->state.err = intel_pt_ext_err(err);
		if (err != -EOVERFLOW)
			decoder->state.from_ip = decoder->ip;
		intel_pt_update_sample_time(decoder);
		decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
		intel_pt_set_nr(decoder);
	} else {
		decoder->state.err = 0;
		if (decoder->cbr != decoder->cbr_seen) {
			decoder->cbr_seen = decoder->cbr;
			if (!decoder->state.type) {
				decoder->state.from_ip = decoder->ip;
				decoder->state.to_ip = 0;
			}
			decoder->state.type |= INTEL_PT_CBR_CHG;
			decoder->state.cbr_payload = decoder->cbr_payload;
			decoder->state.cbr = decoder->cbr;
		}
		if (intel_pt_sample_time(decoder->pkt_state)) {
			intel_pt_update_sample_time(decoder);
			if (decoder->sample_cyc) {
				decoder->sample_tot_cyc_cnt = decoder->tot_cyc_cnt;
				decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
				decoder->sample_cyc = false;
			}
		}
		/*
		 * When using only TSC/MTC to compute cycles, IPC can be
		 * sampled as soon as the cycle count changes.
		 */
		if (!decoder->have_cyc)
			decoder->state.flags |= INTEL_PT_SAMPLE_IPC;
	}

	 /* Let PSB event always have TSC timestamp */
	if ((decoder->state.type & INTEL_PT_PSB_EVT) && decoder->tsc_timestamp)
		decoder->sample_timestamp = decoder->tsc_timestamp;

	decoder->state.from_nr = decoder->nr;
	decoder->state.to_nr = decoder->next_nr;
	decoder->nr = decoder->next_nr;

	decoder->state.timestamp = decoder->sample_timestamp;
	decoder->state.est_timestamp = intel_pt_est_timestamp(decoder);
	decoder->state.tot_insn_cnt = decoder->tot_insn_cnt;
	decoder->state.tot_cyc_cnt = decoder->sample_tot_cyc_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)
{
	enum intel_pt_pkt_ctx ctx = INTEL_PT_NO_CTX;
	struct intel_pt_pkt packet;
	int ret;

	while (len) {
		ret = intel_pt_get_packet(buf, len, &packet, &ctx);
		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;
	}
}

#define MAX_PADDING (PERF_AUXTRACE_RECORD_ALIGNMENT - 1)

/**
 * adj_for_padding - adjust overlap to account for padding.
 * @buf_b: second buffer
 * @buf_a: first buffer
 * @len_a: size of first buffer
 *
 * @buf_a might have up to 7 bytes of padding appended. Adjust the overlap
 * accordingly.
 *
 * Return: A pointer into @buf_b from where non-overlapped data starts
 */
static unsigned char *adj_for_padding(unsigned char *buf_b,
				      unsigned char *buf_a, size_t len_a)
{
	unsigned char *p = buf_b - MAX_PADDING;
	unsigned char *q = buf_a + len_a - MAX_PADDING;
	int i;

	for (i = MAX_PADDING; i; i--, p++, q++) {
		if (*p != *q)
			break;
	}

	return p;
}

/**
 * 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
 * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
 *
 * 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,
						bool ooo_tsc)
{
	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) {
				unsigned char *start;

				*consecutive = true;
				start = buf_b + len_b - (rem_b - rem_a);
				return adj_for_padding(start, buf_a, len_a);
			}
			if (cmp < 0 && !ooo_tsc)
				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
 * @ooo_tsc: out-of-order TSC due to VM TSC offset / scaling
 *
 * 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,
				     bool ooo_tsc)
{
	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, ooo_tsc);
		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 adj_for_padding(buf_b + len_a, buf_a, len_a);
		}

		/* Try again at next PSB in buffer 'a' */
		if (!intel_pt_step_psb(&buf_a, &len_a))
			return buf_b; /* No overlap */
	}
}

/**
 * struct fast_forward_data - data used by intel_pt_ff_cb().
 * @timestamp: timestamp to fast forward towards
 * @buf_timestamp: buffer timestamp of last buffer with trace data earlier than
 *                 the fast forward timestamp.
 */
struct fast_forward_data {
	uint64_t timestamp;
	uint64_t buf_timestamp;
};

/**
 * intel_pt_ff_cb - fast forward lookahead callback.
 * @buffer: Intel PT trace buffer
 * @data: opaque pointer to fast forward data (struct fast_forward_data)
 *
 * Determine if @buffer trace is past the fast forward timestamp.
 *
 * Return: 1 (stop lookahead) if @buffer trace is past the fast forward
 *         timestamp, and 0 otherwise.
 */
static int intel_pt_ff_cb(struct intel_pt_buffer *buffer, void *data)
{
	struct fast_forward_data *d = data;
	unsigned char *buf;
	uint64_t tsc;
	size_t rem;
	size_t len;

	buf = (unsigned char *)buffer->buf;
	len = buffer->len;

	if (!intel_pt_next_psb(&buf, &len) ||
	    !intel_pt_next_tsc(buf, len, &tsc, &rem))
		return 0;

	tsc = intel_pt_8b_tsc(tsc, buffer->ref_timestamp);

	intel_pt_log("Buffer 1st timestamp " x64_fmt " ref timestamp " x64_fmt "\n",
		     tsc, buffer->ref_timestamp);

	/*
	 * If the buffer contains a timestamp earlier that the fast forward
	 * timestamp, then record it, else stop.
	 */
	if (tsc < d->timestamp)
		d->buf_timestamp = buffer->ref_timestamp;
	else
		return 1;

	return 0;
}

/**
 * intel_pt_fast_forward - reposition decoder forwards.
 * @decoder: Intel PT decoder
 * @timestamp: timestamp to fast forward towards
 *
 * Reposition decoder at the last PSB with a timestamp earlier than @timestamp.
 *
 * Return: 0 on success or negative error code on failure.
 */
int intel_pt_fast_forward(struct intel_pt_decoder *decoder, uint64_t timestamp)
{
	struct fast_forward_data d = { .timestamp = timestamp };
	unsigned char *buf;
	size_t len;
	int err;

	intel_pt_log("Fast forward towards timestamp " x64_fmt "\n", timestamp);

	/* Find buffer timestamp of buffer to fast forward to */
	err = decoder->lookahead(decoder->data, intel_pt_ff_cb, &d);
	if (err < 0)
		return err;

	/* Walk to buffer with same buffer timestamp */
	if (d.buf_timestamp) {
		do {
			decoder->pos += decoder->len;
			decoder->len = 0;
			err = intel_pt_get_next_data(decoder, true);
			/* -ENOLINK means non-consecutive trace */
			if (err && err != -ENOLINK)
				return err;
		} while (decoder->buf_timestamp != d.buf_timestamp);
	}

	if (!decoder->buf)
		return 0;

	buf = (unsigned char *)decoder->buf;
	len = decoder->len;

	if (!intel_pt_next_psb(&buf, &len))
		return 0;

	/*
	 * Walk PSBs while the PSB timestamp is less than the fast forward
	 * timestamp.
	 */
	do {
		uint64_t tsc;
		size_t rem;

		if (!intel_pt_next_tsc(buf, len, &tsc, &rem))
			break;
		tsc = intel_pt_8b_tsc(tsc, decoder->buf_timestamp);
		/*
		 * A TSC packet can slip past MTC packets but, after fast
		 * forward, decoding starts at the TSC timestamp. That means
		 * the timestamps may not be exactly the same as the timestamps
		 * that would have been decoded without fast forward.
		 */
		if (tsc < timestamp) {
			intel_pt_log("Fast forward to next PSB timestamp " x64_fmt "\n", tsc);
			decoder->pos += decoder->len - len;
			decoder->buf = buf;
			decoder->len = len;
			intel_pt_reposition(decoder);
		} else {
			break;
		}
	} while (intel_pt_step_psb(&buf, &len));

	return 0;
}