123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867868869870871872873874875876877878879880881882883884885886887888889890891892893894895896897898899900901902903904905906907908909910911912913914915916917918919920921922923924925926927928929930931932933934935936937938939940941942943944945946947948949950951952953954955956957958959960961962963964965966967968969970971972973974975976977978979980981982983984985986987988989990991992993994995996997998999100010011002100310041005100610071008100910101011101210131014101510161017101810191020102110221023102410251026102710281029103010311032103310341035103610371038103910401041104210431044104510461047104810491050105110521053105410551056105710581059106010611062106310641065106610671068106910701071107210731074107510761077107810791080108110821083108410851086108710881089109010911092109310941095109610971098109911001101110211031104110511061107110811091110111111121113111411151116111711181119112011211122112311241125112611271128112911301131113211331134113511361137113811391140114111421143114411451146114711481149115011511152115311541155115611571158115911601161116211631164116511661167116811691170117111721173117411751176117711781179118011811182118311841185118611871188118911901191119211931194119511961197119811991200120112021203120412051206120712081209121012111212121312141215121612171218121912201221122212231224122512261227122812291230123112321233123412351236123712381239124012411242124312441245124612471248124912501251125212531254125512561257125812591260126112621263126412651266126712681269127012711272127312741275127612771278127912801281128212831284128512861287128812891290129112921293129412951296129712981299130013011302130313041305130613071308130913101311131213131314131513161317131813191320132113221323132413251326132713281329133013311332133313341335133613371338133913401341134213431344134513461347134813491350135113521353135413551356135713581359136013611362136313641365136613671368136913701371137213731374137513761377137813791380138113821383138413851386138713881389139013911392139313941395139613971398139914001401140214031404140514061407140814091410141114121413141414151416141714181419142014211422142314241425142614271428142914301431143214331434143514361437143814391440144114421443144414451446144714481449145014511452145314541455145614571458145914601461146214631464146514661467146814691470147114721473147414751476147714781479148014811482148314841485148614871488148914901491149214931494149514961497149814991500150115021503150415051506150715081509151015111512151315141515151615171518151915201521152215231524152515261527152815291530153115321533153415351536153715381539154015411542154315441545154615471548154915501551155215531554155515561557155815591560156115621563156415651566156715681569157015711572157315741575157615771578157915801581158215831584158515861587158815891590159115921593159415951596159715981599160016011602160316041605160616071608160916101611161216131614161516161617161816191620162116221623162416251626162716281629163016311632163316341635163616371638163916401641164216431644164516461647164816491650165116521653165416551656165716581659166016611662166316641665166616671668166916701671167216731674167516761677167816791680168116821683168416851686168716881689169016911692169316941695169616971698169917001701170217031704170517061707170817091710171117121713171417151716171717181719172017211722172317241725172617271728172917301731173217331734173517361737173817391740174117421743174417451746174717481749175017511752175317541755175617571758175917601761176217631764176517661767176817691770177117721773177417751776177717781779178017811782178317841785178617871788178917901791179217931794179517961797179817991800180118021803180418051806180718081809181018111812181318141815181618171818181918201821182218231824182518261827182818291830183118321833183418351836183718381839184018411842184318441845184618471848184918501851185218531854185518561857185818591860186118621863186418651866186718681869187018711872187318741875187618771878187918801881188218831884188518861887188818891890189118921893189418951896189718981899190019011902190319041905190619071908190919101911191219131914191519161917191819191920192119221923192419251926192719281929193019311932193319341935193619371938193919401941 |
- // SPDX-License-Identifier: GPL-2.0-or-later
- /*
- * Copyright IBM Corporation 2001, 2005, 2006
- * Copyright Dave Engebretsen & Todd Inglett 2001
- * Copyright Linas Vepstas 2005, 2006
- * Copyright 2001-2012 IBM Corporation.
- *
- * Please address comments and feedback to Linas Vepstas <[email protected]>
- */
- #include <linux/delay.h>
- #include <linux/sched.h>
- #include <linux/init.h>
- #include <linux/list.h>
- #include <linux/pci.h>
- #include <linux/iommu.h>
- #include <linux/proc_fs.h>
- #include <linux/rbtree.h>
- #include <linux/reboot.h>
- #include <linux/seq_file.h>
- #include <linux/spinlock.h>
- #include <linux/export.h>
- #include <linux/of.h>
- #include <linux/debugfs.h>
- #include <linux/atomic.h>
- #include <asm/eeh.h>
- #include <asm/eeh_event.h>
- #include <asm/io.h>
- #include <asm/iommu.h>
- #include <asm/machdep.h>
- #include <asm/ppc-pci.h>
- #include <asm/rtas.h>
- #include <asm/pte-walk.h>
- /** Overview:
- * EEH, or "Enhanced Error Handling" is a PCI bridge technology for
- * dealing with PCI bus errors that can't be dealt with within the
- * usual PCI framework, except by check-stopping the CPU. Systems
- * that are designed for high-availability/reliability cannot afford
- * to crash due to a "mere" PCI error, thus the need for EEH.
- * An EEH-capable bridge operates by converting a detected error
- * into a "slot freeze", taking the PCI adapter off-line, making
- * the slot behave, from the OS'es point of view, as if the slot
- * were "empty": all reads return 0xff's and all writes are silently
- * ignored. EEH slot isolation events can be triggered by parity
- * errors on the address or data busses (e.g. during posted writes),
- * which in turn might be caused by low voltage on the bus, dust,
- * vibration, humidity, radioactivity or plain-old failed hardware.
- *
- * Note, however, that one of the leading causes of EEH slot
- * freeze events are buggy device drivers, buggy device microcode,
- * or buggy device hardware. This is because any attempt by the
- * device to bus-master data to a memory address that is not
- * assigned to the device will trigger a slot freeze. (The idea
- * is to prevent devices-gone-wild from corrupting system memory).
- * Buggy hardware/drivers will have a miserable time co-existing
- * with EEH.
- *
- * Ideally, a PCI device driver, when suspecting that an isolation
- * event has occurred (e.g. by reading 0xff's), will then ask EEH
- * whether this is the case, and then take appropriate steps to
- * reset the PCI slot, the PCI device, and then resume operations.
- * However, until that day, the checking is done here, with the
- * eeh_check_failure() routine embedded in the MMIO macros. If
- * the slot is found to be isolated, an "EEH Event" is synthesized
- * and sent out for processing.
- */
- /* If a device driver keeps reading an MMIO register in an interrupt
- * handler after a slot isolation event, it might be broken.
- * This sets the threshold for how many read attempts we allow
- * before printing an error message.
- */
- #define EEH_MAX_FAILS 2100000
- /* Time to wait for a PCI slot to report status, in milliseconds */
- #define PCI_BUS_RESET_WAIT_MSEC (5*60*1000)
- /*
- * EEH probe mode support, which is part of the flags,
- * is to support multiple platforms for EEH. Some platforms
- * like pSeries do PCI emunation based on device tree.
- * However, other platforms like powernv probe PCI devices
- * from hardware. The flag is used to distinguish that.
- * In addition, struct eeh_ops::probe would be invoked for
- * particular OF node or PCI device so that the corresponding
- * PE would be created there.
- */
- int eeh_subsystem_flags;
- EXPORT_SYMBOL(eeh_subsystem_flags);
- /*
- * EEH allowed maximal frozen times. If one particular PE's
- * frozen count in last hour exceeds this limit, the PE will
- * be forced to be offline permanently.
- */
- u32 eeh_max_freezes = 5;
- /*
- * Controls whether a recovery event should be scheduled when an
- * isolated device is discovered. This is only really useful for
- * debugging problems with the EEH core.
- */
- bool eeh_debugfs_no_recover;
- /* Platform dependent EEH operations */
- struct eeh_ops *eeh_ops = NULL;
- /* Lock to avoid races due to multiple reports of an error */
- DEFINE_RAW_SPINLOCK(confirm_error_lock);
- EXPORT_SYMBOL_GPL(confirm_error_lock);
- /* Lock to protect passed flags */
- static DEFINE_MUTEX(eeh_dev_mutex);
- /* Buffer for reporting pci register dumps. Its here in BSS, and
- * not dynamically alloced, so that it ends up in RMO where RTAS
- * can access it.
- */
- #define EEH_PCI_REGS_LOG_LEN 8192
- static unsigned char pci_regs_buf[EEH_PCI_REGS_LOG_LEN];
- /*
- * The struct is used to maintain the EEH global statistic
- * information. Besides, the EEH global statistics will be
- * exported to user space through procfs
- */
- struct eeh_stats {
- u64 no_device; /* PCI device not found */
- u64 no_dn; /* OF node not found */
- u64 no_cfg_addr; /* Config address not found */
- u64 ignored_check; /* EEH check skipped */
- u64 total_mmio_ffs; /* Total EEH checks */
- u64 false_positives; /* Unnecessary EEH checks */
- u64 slot_resets; /* PE reset */
- };
- static struct eeh_stats eeh_stats;
- static int __init eeh_setup(char *str)
- {
- if (!strcmp(str, "off"))
- eeh_add_flag(EEH_FORCE_DISABLED);
- else if (!strcmp(str, "early_log"))
- eeh_add_flag(EEH_EARLY_DUMP_LOG);
- return 1;
- }
- __setup("eeh=", eeh_setup);
- void eeh_show_enabled(void)
- {
- if (eeh_has_flag(EEH_FORCE_DISABLED))
- pr_info("EEH: Recovery disabled by kernel parameter.\n");
- else if (eeh_has_flag(EEH_ENABLED))
- pr_info("EEH: Capable adapter found: recovery enabled.\n");
- else
- pr_info("EEH: No capable adapters found: recovery disabled.\n");
- }
- /*
- * This routine captures assorted PCI configuration space data
- * for the indicated PCI device, and puts them into a buffer
- * for RTAS error logging.
- */
- static size_t eeh_dump_dev_log(struct eeh_dev *edev, char *buf, size_t len)
- {
- u32 cfg;
- int cap, i;
- int n = 0, l = 0;
- char buffer[128];
- n += scnprintf(buf+n, len-n, "%04x:%02x:%02x.%01x\n",
- edev->pe->phb->global_number, edev->bdfn >> 8,
- PCI_SLOT(edev->bdfn), PCI_FUNC(edev->bdfn));
- pr_warn("EEH: of node=%04x:%02x:%02x.%01x\n",
- edev->pe->phb->global_number, edev->bdfn >> 8,
- PCI_SLOT(edev->bdfn), PCI_FUNC(edev->bdfn));
- eeh_ops->read_config(edev, PCI_VENDOR_ID, 4, &cfg);
- n += scnprintf(buf+n, len-n, "dev/vend:%08x\n", cfg);
- pr_warn("EEH: PCI device/vendor: %08x\n", cfg);
- eeh_ops->read_config(edev, PCI_COMMAND, 4, &cfg);
- n += scnprintf(buf+n, len-n, "cmd/stat:%x\n", cfg);
- pr_warn("EEH: PCI cmd/status register: %08x\n", cfg);
- /* Gather bridge-specific registers */
- if (edev->mode & EEH_DEV_BRIDGE) {
- eeh_ops->read_config(edev, PCI_SEC_STATUS, 2, &cfg);
- n += scnprintf(buf+n, len-n, "sec stat:%x\n", cfg);
- pr_warn("EEH: Bridge secondary status: %04x\n", cfg);
- eeh_ops->read_config(edev, PCI_BRIDGE_CONTROL, 2, &cfg);
- n += scnprintf(buf+n, len-n, "brdg ctl:%x\n", cfg);
- pr_warn("EEH: Bridge control: %04x\n", cfg);
- }
- /* Dump out the PCI-X command and status regs */
- cap = edev->pcix_cap;
- if (cap) {
- eeh_ops->read_config(edev, cap, 4, &cfg);
- n += scnprintf(buf+n, len-n, "pcix-cmd:%x\n", cfg);
- pr_warn("EEH: PCI-X cmd: %08x\n", cfg);
- eeh_ops->read_config(edev, cap+4, 4, &cfg);
- n += scnprintf(buf+n, len-n, "pcix-stat:%x\n", cfg);
- pr_warn("EEH: PCI-X status: %08x\n", cfg);
- }
- /* If PCI-E capable, dump PCI-E cap 10 */
- cap = edev->pcie_cap;
- if (cap) {
- n += scnprintf(buf+n, len-n, "pci-e cap10:\n");
- pr_warn("EEH: PCI-E capabilities and status follow:\n");
- for (i=0; i<=8; i++) {
- eeh_ops->read_config(edev, cap+4*i, 4, &cfg);
- n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg);
- if ((i % 4) == 0) {
- if (i != 0)
- pr_warn("%s\n", buffer);
- l = scnprintf(buffer, sizeof(buffer),
- "EEH: PCI-E %02x: %08x ",
- 4*i, cfg);
- } else {
- l += scnprintf(buffer+l, sizeof(buffer)-l,
- "%08x ", cfg);
- }
- }
- pr_warn("%s\n", buffer);
- }
- /* If AER capable, dump it */
- cap = edev->aer_cap;
- if (cap) {
- n += scnprintf(buf+n, len-n, "pci-e AER:\n");
- pr_warn("EEH: PCI-E AER capability register set follows:\n");
- for (i=0; i<=13; i++) {
- eeh_ops->read_config(edev, cap+4*i, 4, &cfg);
- n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg);
- if ((i % 4) == 0) {
- if (i != 0)
- pr_warn("%s\n", buffer);
- l = scnprintf(buffer, sizeof(buffer),
- "EEH: PCI-E AER %02x: %08x ",
- 4*i, cfg);
- } else {
- l += scnprintf(buffer+l, sizeof(buffer)-l,
- "%08x ", cfg);
- }
- }
- pr_warn("%s\n", buffer);
- }
- return n;
- }
- static void *eeh_dump_pe_log(struct eeh_pe *pe, void *flag)
- {
- struct eeh_dev *edev, *tmp;
- size_t *plen = flag;
- eeh_pe_for_each_dev(pe, edev, tmp)
- *plen += eeh_dump_dev_log(edev, pci_regs_buf + *plen,
- EEH_PCI_REGS_LOG_LEN - *plen);
- return NULL;
- }
- /**
- * eeh_slot_error_detail - Generate combined log including driver log and error log
- * @pe: EEH PE
- * @severity: temporary or permanent error log
- *
- * This routine should be called to generate the combined log, which
- * is comprised of driver log and error log. The driver log is figured
- * out from the config space of the corresponding PCI device, while
- * the error log is fetched through platform dependent function call.
- */
- void eeh_slot_error_detail(struct eeh_pe *pe, int severity)
- {
- size_t loglen = 0;
- /*
- * When the PHB is fenced or dead, it's pointless to collect
- * the data from PCI config space because it should return
- * 0xFF's. For ER, we still retrieve the data from the PCI
- * config space.
- *
- * For pHyp, we have to enable IO for log retrieval. Otherwise,
- * 0xFF's is always returned from PCI config space.
- *
- * When the @severity is EEH_LOG_PERM, the PE is going to be
- * removed. Prior to that, the drivers for devices included in
- * the PE will be closed. The drivers rely on working IO path
- * to bring the devices to quiet state. Otherwise, PCI traffic
- * from those devices after they are removed is like to cause
- * another unexpected EEH error.
- */
- if (!(pe->type & EEH_PE_PHB)) {
- if (eeh_has_flag(EEH_ENABLE_IO_FOR_LOG) ||
- severity == EEH_LOG_PERM)
- eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
- /*
- * The config space of some PCI devices can't be accessed
- * when their PEs are in frozen state. Otherwise, fenced
- * PHB might be seen. Those PEs are identified with flag
- * EEH_PE_CFG_RESTRICTED, indicating EEH_PE_CFG_BLOCKED
- * is set automatically when the PE is put to EEH_PE_ISOLATED.
- *
- * Restoring BARs possibly triggers PCI config access in
- * (OPAL) firmware and then causes fenced PHB. If the
- * PCI config is blocked with flag EEH_PE_CFG_BLOCKED, it's
- * pointless to restore BARs and dump config space.
- */
- eeh_ops->configure_bridge(pe);
- if (!(pe->state & EEH_PE_CFG_BLOCKED)) {
- eeh_pe_restore_bars(pe);
- pci_regs_buf[0] = 0;
- eeh_pe_traverse(pe, eeh_dump_pe_log, &loglen);
- }
- }
- eeh_ops->get_log(pe, severity, pci_regs_buf, loglen);
- }
- /**
- * eeh_token_to_phys - Convert EEH address token to phys address
- * @token: I/O token, should be address in the form 0xA....
- *
- * This routine should be called to convert virtual I/O address
- * to physical one.
- */
- static inline unsigned long eeh_token_to_phys(unsigned long token)
- {
- return ppc_find_vmap_phys(token);
- }
- /*
- * On PowerNV platform, we might already have fenced PHB there.
- * For that case, it's meaningless to recover frozen PE. Intead,
- * We have to handle fenced PHB firstly.
- */
- static int eeh_phb_check_failure(struct eeh_pe *pe)
- {
- struct eeh_pe *phb_pe;
- unsigned long flags;
- int ret;
- if (!eeh_has_flag(EEH_PROBE_MODE_DEV))
- return -EPERM;
- /* Find the PHB PE */
- phb_pe = eeh_phb_pe_get(pe->phb);
- if (!phb_pe) {
- pr_warn("%s Can't find PE for PHB#%x\n",
- __func__, pe->phb->global_number);
- return -EEXIST;
- }
- /* If the PHB has been in problematic state */
- eeh_serialize_lock(&flags);
- if (phb_pe->state & EEH_PE_ISOLATED) {
- ret = 0;
- goto out;
- }
- /* Check PHB state */
- ret = eeh_ops->get_state(phb_pe, NULL);
- if ((ret < 0) ||
- (ret == EEH_STATE_NOT_SUPPORT) || eeh_state_active(ret)) {
- ret = 0;
- goto out;
- }
- /* Isolate the PHB and send event */
- eeh_pe_mark_isolated(phb_pe);
- eeh_serialize_unlock(flags);
- pr_debug("EEH: PHB#%x failure detected, location: %s\n",
- phb_pe->phb->global_number, eeh_pe_loc_get(phb_pe));
- eeh_send_failure_event(phb_pe);
- return 1;
- out:
- eeh_serialize_unlock(flags);
- return ret;
- }
- static inline const char *eeh_driver_name(struct pci_dev *pdev)
- {
- if (pdev)
- return dev_driver_string(&pdev->dev);
- return "<null>";
- }
- /**
- * eeh_dev_check_failure - Check if all 1's data is due to EEH slot freeze
- * @edev: eeh device
- *
- * Check for an EEH failure for the given device node. Call this
- * routine if the result of a read was all 0xff's and you want to
- * find out if this is due to an EEH slot freeze. This routine
- * will query firmware for the EEH status.
- *
- * Returns 0 if there has not been an EEH error; otherwise returns
- * a non-zero value and queues up a slot isolation event notification.
- *
- * It is safe to call this routine in an interrupt context.
- */
- int eeh_dev_check_failure(struct eeh_dev *edev)
- {
- int ret;
- unsigned long flags;
- struct device_node *dn;
- struct pci_dev *dev;
- struct eeh_pe *pe, *parent_pe;
- int rc = 0;
- const char *location = NULL;
- eeh_stats.total_mmio_ffs++;
- if (!eeh_enabled())
- return 0;
- if (!edev) {
- eeh_stats.no_dn++;
- return 0;
- }
- dev = eeh_dev_to_pci_dev(edev);
- pe = eeh_dev_to_pe(edev);
- /* Access to IO BARs might get this far and still not want checking. */
- if (!pe) {
- eeh_stats.ignored_check++;
- eeh_edev_dbg(edev, "Ignored check\n");
- return 0;
- }
- /*
- * On PowerNV platform, we might already have fenced PHB
- * there and we need take care of that firstly.
- */
- ret = eeh_phb_check_failure(pe);
- if (ret > 0)
- return ret;
- /*
- * If the PE isn't owned by us, we shouldn't check the
- * state. Instead, let the owner handle it if the PE has
- * been frozen.
- */
- if (eeh_pe_passed(pe))
- return 0;
- /* If we already have a pending isolation event for this
- * slot, we know it's bad already, we don't need to check.
- * Do this checking under a lock; as multiple PCI devices
- * in one slot might report errors simultaneously, and we
- * only want one error recovery routine running.
- */
- eeh_serialize_lock(&flags);
- rc = 1;
- if (pe->state & EEH_PE_ISOLATED) {
- pe->check_count++;
- if (pe->check_count == EEH_MAX_FAILS) {
- dn = pci_device_to_OF_node(dev);
- if (dn)
- location = of_get_property(dn, "ibm,loc-code",
- NULL);
- eeh_edev_err(edev, "%d reads ignored for recovering device at location=%s driver=%s\n",
- pe->check_count,
- location ? location : "unknown",
- eeh_driver_name(dev));
- eeh_edev_err(edev, "Might be infinite loop in %s driver\n",
- eeh_driver_name(dev));
- dump_stack();
- }
- goto dn_unlock;
- }
- /*
- * Now test for an EEH failure. This is VERY expensive.
- * Note that the eeh_config_addr may be a parent device
- * in the case of a device behind a bridge, or it may be
- * function zero of a multi-function device.
- * In any case they must share a common PHB.
- */
- ret = eeh_ops->get_state(pe, NULL);
- /* Note that config-io to empty slots may fail;
- * they are empty when they don't have children.
- * We will punt with the following conditions: Failure to get
- * PE's state, EEH not support and Permanently unavailable
- * state, PE is in good state.
- */
- if ((ret < 0) ||
- (ret == EEH_STATE_NOT_SUPPORT) || eeh_state_active(ret)) {
- eeh_stats.false_positives++;
- pe->false_positives++;
- rc = 0;
- goto dn_unlock;
- }
- /*
- * It should be corner case that the parent PE has been
- * put into frozen state as well. We should take care
- * that at first.
- */
- parent_pe = pe->parent;
- while (parent_pe) {
- /* Hit the ceiling ? */
- if (parent_pe->type & EEH_PE_PHB)
- break;
- /* Frozen parent PE ? */
- ret = eeh_ops->get_state(parent_pe, NULL);
- if (ret > 0 && !eeh_state_active(ret)) {
- pe = parent_pe;
- pr_err("EEH: Failure of PHB#%x-PE#%x will be handled at parent PHB#%x-PE#%x.\n",
- pe->phb->global_number, pe->addr,
- pe->phb->global_number, parent_pe->addr);
- }
- /* Next parent level */
- parent_pe = parent_pe->parent;
- }
- eeh_stats.slot_resets++;
- /* Avoid repeated reports of this failure, including problems
- * with other functions on this device, and functions under
- * bridges.
- */
- eeh_pe_mark_isolated(pe);
- eeh_serialize_unlock(flags);
- /* Most EEH events are due to device driver bugs. Having
- * a stack trace will help the device-driver authors figure
- * out what happened. So print that out.
- */
- pr_debug("EEH: %s: Frozen PHB#%x-PE#%x detected\n",
- __func__, pe->phb->global_number, pe->addr);
- eeh_send_failure_event(pe);
- return 1;
- dn_unlock:
- eeh_serialize_unlock(flags);
- return rc;
- }
- EXPORT_SYMBOL_GPL(eeh_dev_check_failure);
- /**
- * eeh_check_failure - Check if all 1's data is due to EEH slot freeze
- * @token: I/O address
- *
- * Check for an EEH failure at the given I/O address. Call this
- * routine if the result of a read was all 0xff's and you want to
- * find out if this is due to an EEH slot freeze event. This routine
- * will query firmware for the EEH status.
- *
- * Note this routine is safe to call in an interrupt context.
- */
- int eeh_check_failure(const volatile void __iomem *token)
- {
- unsigned long addr;
- struct eeh_dev *edev;
- /* Finding the phys addr + pci device; this is pretty quick. */
- addr = eeh_token_to_phys((unsigned long __force) token);
- edev = eeh_addr_cache_get_dev(addr);
- if (!edev) {
- eeh_stats.no_device++;
- return 0;
- }
- return eeh_dev_check_failure(edev);
- }
- EXPORT_SYMBOL(eeh_check_failure);
- /**
- * eeh_pci_enable - Enable MMIO or DMA transfers for this slot
- * @pe: EEH PE
- * @function: EEH option
- *
- * This routine should be called to reenable frozen MMIO or DMA
- * so that it would work correctly again. It's useful while doing
- * recovery or log collection on the indicated device.
- */
- int eeh_pci_enable(struct eeh_pe *pe, int function)
- {
- int active_flag, rc;
- /*
- * pHyp doesn't allow to enable IO or DMA on unfrozen PE.
- * Also, it's pointless to enable them on unfrozen PE. So
- * we have to check before enabling IO or DMA.
- */
- switch (function) {
- case EEH_OPT_THAW_MMIO:
- active_flag = EEH_STATE_MMIO_ACTIVE | EEH_STATE_MMIO_ENABLED;
- break;
- case EEH_OPT_THAW_DMA:
- active_flag = EEH_STATE_DMA_ACTIVE;
- break;
- case EEH_OPT_DISABLE:
- case EEH_OPT_ENABLE:
- case EEH_OPT_FREEZE_PE:
- active_flag = 0;
- break;
- default:
- pr_warn("%s: Invalid function %d\n",
- __func__, function);
- return -EINVAL;
- }
- /*
- * Check if IO or DMA has been enabled before
- * enabling them.
- */
- if (active_flag) {
- rc = eeh_ops->get_state(pe, NULL);
- if (rc < 0)
- return rc;
- /* Needn't enable it at all */
- if (rc == EEH_STATE_NOT_SUPPORT)
- return 0;
- /* It's already enabled */
- if (rc & active_flag)
- return 0;
- }
- /* Issue the request */
- rc = eeh_ops->set_option(pe, function);
- if (rc)
- pr_warn("%s: Unexpected state change %d on "
- "PHB#%x-PE#%x, err=%d\n",
- __func__, function, pe->phb->global_number,
- pe->addr, rc);
- /* Check if the request is finished successfully */
- if (active_flag) {
- rc = eeh_wait_state(pe, PCI_BUS_RESET_WAIT_MSEC);
- if (rc < 0)
- return rc;
- if (rc & active_flag)
- return 0;
- return -EIO;
- }
- return rc;
- }
- static void eeh_disable_and_save_dev_state(struct eeh_dev *edev,
- void *userdata)
- {
- struct pci_dev *pdev = eeh_dev_to_pci_dev(edev);
- struct pci_dev *dev = userdata;
- /*
- * The caller should have disabled and saved the
- * state for the specified device
- */
- if (!pdev || pdev == dev)
- return;
- /* Ensure we have D0 power state */
- pci_set_power_state(pdev, PCI_D0);
- /* Save device state */
- pci_save_state(pdev);
- /*
- * Disable device to avoid any DMA traffic and
- * interrupt from the device
- */
- pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
- }
- static void eeh_restore_dev_state(struct eeh_dev *edev, void *userdata)
- {
- struct pci_dev *pdev = eeh_dev_to_pci_dev(edev);
- struct pci_dev *dev = userdata;
- if (!pdev)
- return;
- /* Apply customization from firmware */
- if (eeh_ops->restore_config)
- eeh_ops->restore_config(edev);
- /* The caller should restore state for the specified device */
- if (pdev != dev)
- pci_restore_state(pdev);
- }
- /**
- * pcibios_set_pcie_reset_state - Set PCI-E reset state
- * @dev: pci device struct
- * @state: reset state to enter
- *
- * Return value:
- * 0 if success
- */
- int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
- {
- struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
- struct eeh_pe *pe = eeh_dev_to_pe(edev);
- if (!pe) {
- pr_err("%s: No PE found on PCI device %s\n",
- __func__, pci_name(dev));
- return -EINVAL;
- }
- switch (state) {
- case pcie_deassert_reset:
- eeh_ops->reset(pe, EEH_RESET_DEACTIVATE);
- eeh_unfreeze_pe(pe);
- if (!(pe->type & EEH_PE_VF))
- eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, true);
- eeh_pe_dev_traverse(pe, eeh_restore_dev_state, dev);
- eeh_pe_state_clear(pe, EEH_PE_ISOLATED, true);
- break;
- case pcie_hot_reset:
- eeh_pe_mark_isolated(pe);
- eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, true);
- eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE);
- eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev);
- if (!(pe->type & EEH_PE_VF))
- eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED);
- eeh_ops->reset(pe, EEH_RESET_HOT);
- break;
- case pcie_warm_reset:
- eeh_pe_mark_isolated(pe);
- eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, true);
- eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE);
- eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev);
- if (!(pe->type & EEH_PE_VF))
- eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED);
- eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL);
- break;
- default:
- eeh_pe_state_clear(pe, EEH_PE_ISOLATED | EEH_PE_CFG_BLOCKED, true);
- return -EINVAL;
- }
- return 0;
- }
- /**
- * eeh_set_dev_freset - Check the required reset for the indicated device
- * @edev: EEH device
- * @flag: return value
- *
- * Each device might have its preferred reset type: fundamental or
- * hot reset. The routine is used to collected the information for
- * the indicated device and its children so that the bunch of the
- * devices could be reset properly.
- */
- static void eeh_set_dev_freset(struct eeh_dev *edev, void *flag)
- {
- struct pci_dev *dev;
- unsigned int *freset = (unsigned int *)flag;
- dev = eeh_dev_to_pci_dev(edev);
- if (dev)
- *freset |= dev->needs_freset;
- }
- static void eeh_pe_refreeze_passed(struct eeh_pe *root)
- {
- struct eeh_pe *pe;
- int state;
- eeh_for_each_pe(root, pe) {
- if (eeh_pe_passed(pe)) {
- state = eeh_ops->get_state(pe, NULL);
- if (state &
- (EEH_STATE_MMIO_ACTIVE | EEH_STATE_MMIO_ENABLED)) {
- pr_info("EEH: Passed-through PE PHB#%x-PE#%x was thawed by reset, re-freezing for safety.\n",
- pe->phb->global_number, pe->addr);
- eeh_pe_set_option(pe, EEH_OPT_FREEZE_PE);
- }
- }
- }
- }
- /**
- * eeh_pe_reset_full - Complete a full reset process on the indicated PE
- * @pe: EEH PE
- * @include_passed: include passed-through devices?
- *
- * This function executes a full reset procedure on a PE, including setting
- * the appropriate flags, performing a fundamental or hot reset, and then
- * deactivating the reset status. It is designed to be used within the EEH
- * subsystem, as opposed to eeh_pe_reset which is exported to drivers and
- * only performs a single operation at a time.
- *
- * This function will attempt to reset a PE three times before failing.
- */
- int eeh_pe_reset_full(struct eeh_pe *pe, bool include_passed)
- {
- int reset_state = (EEH_PE_RESET | EEH_PE_CFG_BLOCKED);
- int type = EEH_RESET_HOT;
- unsigned int freset = 0;
- int i, state = 0, ret;
- /*
- * Determine the type of reset to perform - hot or fundamental.
- * Hot reset is the default operation, unless any device under the
- * PE requires a fundamental reset.
- */
- eeh_pe_dev_traverse(pe, eeh_set_dev_freset, &freset);
- if (freset)
- type = EEH_RESET_FUNDAMENTAL;
- /* Mark the PE as in reset state and block config space accesses */
- eeh_pe_state_mark(pe, reset_state);
- /* Make three attempts at resetting the bus */
- for (i = 0; i < 3; i++) {
- ret = eeh_pe_reset(pe, type, include_passed);
- if (!ret)
- ret = eeh_pe_reset(pe, EEH_RESET_DEACTIVATE,
- include_passed);
- if (ret) {
- ret = -EIO;
- pr_warn("EEH: Failure %d resetting PHB#%x-PE#%x (attempt %d)\n\n",
- state, pe->phb->global_number, pe->addr, i + 1);
- continue;
- }
- if (i)
- pr_warn("EEH: PHB#%x-PE#%x: Successful reset (attempt %d)\n",
- pe->phb->global_number, pe->addr, i + 1);
- /* Wait until the PE is in a functioning state */
- state = eeh_wait_state(pe, PCI_BUS_RESET_WAIT_MSEC);
- if (state < 0) {
- pr_warn("EEH: Unrecoverable slot failure on PHB#%x-PE#%x",
- pe->phb->global_number, pe->addr);
- ret = -ENOTRECOVERABLE;
- break;
- }
- if (eeh_state_active(state))
- break;
- else
- pr_warn("EEH: PHB#%x-PE#%x: Slot inactive after reset: 0x%x (attempt %d)\n",
- pe->phb->global_number, pe->addr, state, i + 1);
- }
- /* Resetting the PE may have unfrozen child PEs. If those PEs have been
- * (potentially) passed through to a guest, re-freeze them:
- */
- if (!include_passed)
- eeh_pe_refreeze_passed(pe);
- eeh_pe_state_clear(pe, reset_state, true);
- return ret;
- }
- /**
- * eeh_save_bars - Save device bars
- * @edev: PCI device associated EEH device
- *
- * Save the values of the device bars. Unlike the restore
- * routine, this routine is *not* recursive. This is because
- * PCI devices are added individually; but, for the restore,
- * an entire slot is reset at a time.
- */
- void eeh_save_bars(struct eeh_dev *edev)
- {
- int i;
- if (!edev)
- return;
- for (i = 0; i < 16; i++)
- eeh_ops->read_config(edev, i * 4, 4, &edev->config_space[i]);
- /*
- * For PCI bridges including root port, we need enable bus
- * master explicitly. Otherwise, it can't fetch IODA table
- * entries correctly. So we cache the bit in advance so that
- * we can restore it after reset, either PHB range or PE range.
- */
- if (edev->mode & EEH_DEV_BRIDGE)
- edev->config_space[1] |= PCI_COMMAND_MASTER;
- }
- static int eeh_reboot_notifier(struct notifier_block *nb,
- unsigned long action, void *unused)
- {
- eeh_clear_flag(EEH_ENABLED);
- return NOTIFY_DONE;
- }
- static struct notifier_block eeh_reboot_nb = {
- .notifier_call = eeh_reboot_notifier,
- };
- static int eeh_device_notifier(struct notifier_block *nb,
- unsigned long action, void *data)
- {
- struct device *dev = data;
- switch (action) {
- /*
- * Note: It's not possible to perform EEH device addition (i.e.
- * {pseries,pnv}_pcibios_bus_add_device()) here because it depends on
- * the device's resources, which have not yet been set up.
- */
- case BUS_NOTIFY_DEL_DEVICE:
- eeh_remove_device(to_pci_dev(dev));
- break;
- default:
- break;
- }
- return NOTIFY_DONE;
- }
- static struct notifier_block eeh_device_nb = {
- .notifier_call = eeh_device_notifier,
- };
- /**
- * eeh_init - System wide EEH initialization
- * @ops: struct to trace EEH operation callback functions
- *
- * It's the platform's job to call this from an arch_initcall().
- */
- int eeh_init(struct eeh_ops *ops)
- {
- struct pci_controller *hose, *tmp;
- int ret = 0;
- /* the platform should only initialise EEH once */
- if (WARN_ON(eeh_ops))
- return -EEXIST;
- if (WARN_ON(!ops))
- return -ENOENT;
- eeh_ops = ops;
- /* Register reboot notifier */
- ret = register_reboot_notifier(&eeh_reboot_nb);
- if (ret) {
- pr_warn("%s: Failed to register reboot notifier (%d)\n",
- __func__, ret);
- return ret;
- }
- ret = bus_register_notifier(&pci_bus_type, &eeh_device_nb);
- if (ret) {
- pr_warn("%s: Failed to register bus notifier (%d)\n",
- __func__, ret);
- return ret;
- }
- /* Initialize PHB PEs */
- list_for_each_entry_safe(hose, tmp, &hose_list, list_node)
- eeh_phb_pe_create(hose);
- eeh_addr_cache_init();
- /* Initialize EEH event */
- return eeh_event_init();
- }
- /**
- * eeh_probe_device() - Perform EEH initialization for the indicated pci device
- * @dev: pci device for which to set up EEH
- *
- * This routine must be used to complete EEH initialization for PCI
- * devices that were added after system boot (e.g. hotplug, dlpar).
- */
- void eeh_probe_device(struct pci_dev *dev)
- {
- struct eeh_dev *edev;
- pr_debug("EEH: Adding device %s\n", pci_name(dev));
- /*
- * pci_dev_to_eeh_dev() can only work if eeh_probe_dev() was
- * already called for this device.
- */
- if (WARN_ON_ONCE(pci_dev_to_eeh_dev(dev))) {
- pci_dbg(dev, "Already bound to an eeh_dev!\n");
- return;
- }
- edev = eeh_ops->probe(dev);
- if (!edev) {
- pr_debug("EEH: Adding device failed\n");
- return;
- }
- /*
- * FIXME: We rely on pcibios_release_device() to remove the
- * existing EEH state. The release function is only called if
- * the pci_dev's refcount drops to zero so if something is
- * keeping a ref to a device (e.g. a filesystem) we need to
- * remove the old EEH state.
- *
- * FIXME: HEY MA, LOOK AT ME, NO LOCKING!
- */
- if (edev->pdev && edev->pdev != dev) {
- eeh_pe_tree_remove(edev);
- eeh_addr_cache_rmv_dev(edev->pdev);
- eeh_sysfs_remove_device(edev->pdev);
- /*
- * We definitely should have the PCI device removed
- * though it wasn't correctly. So we needn't call
- * into error handler afterwards.
- */
- edev->mode |= EEH_DEV_NO_HANDLER;
- }
- /* bind the pdev and the edev together */
- edev->pdev = dev;
- dev->dev.archdata.edev = edev;
- eeh_addr_cache_insert_dev(dev);
- eeh_sysfs_add_device(dev);
- }
- /**
- * eeh_remove_device - Undo EEH setup for the indicated pci device
- * @dev: pci device to be removed
- *
- * This routine should be called when a device is removed from
- * a running system (e.g. by hotplug or dlpar). It unregisters
- * the PCI device from the EEH subsystem. I/O errors affecting
- * this device will no longer be detected after this call; thus,
- * i/o errors affecting this slot may leave this device unusable.
- */
- void eeh_remove_device(struct pci_dev *dev)
- {
- struct eeh_dev *edev;
- if (!dev || !eeh_enabled())
- return;
- edev = pci_dev_to_eeh_dev(dev);
- /* Unregister the device with the EEH/PCI address search system */
- dev_dbg(&dev->dev, "EEH: Removing device\n");
- if (!edev || !edev->pdev || !edev->pe) {
- dev_dbg(&dev->dev, "EEH: Device not referenced!\n");
- return;
- }
- /*
- * During the hotplug for EEH error recovery, we need the EEH
- * device attached to the parent PE in order for BAR restore
- * a bit later. So we keep it for BAR restore and remove it
- * from the parent PE during the BAR resotre.
- */
- edev->pdev = NULL;
- /*
- * eeh_sysfs_remove_device() uses pci_dev_to_eeh_dev() so we need to
- * remove the sysfs files before clearing dev.archdata.edev
- */
- if (edev->mode & EEH_DEV_SYSFS)
- eeh_sysfs_remove_device(dev);
- /*
- * We're removing from the PCI subsystem, that means
- * the PCI device driver can't support EEH or not
- * well. So we rely on hotplug completely to do recovery
- * for the specific PCI device.
- */
- edev->mode |= EEH_DEV_NO_HANDLER;
- eeh_addr_cache_rmv_dev(dev);
- /*
- * The flag "in_error" is used to trace EEH devices for VFs
- * in error state or not. It's set in eeh_report_error(). If
- * it's not set, eeh_report_{reset,resume}() won't be called
- * for the VF EEH device.
- */
- edev->in_error = false;
- dev->dev.archdata.edev = NULL;
- if (!(edev->pe->state & EEH_PE_KEEP))
- eeh_pe_tree_remove(edev);
- else
- edev->mode |= EEH_DEV_DISCONNECTED;
- }
- int eeh_unfreeze_pe(struct eeh_pe *pe)
- {
- int ret;
- ret = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO);
- if (ret) {
- pr_warn("%s: Failure %d enabling IO on PHB#%x-PE#%x\n",
- __func__, ret, pe->phb->global_number, pe->addr);
- return ret;
- }
- ret = eeh_pci_enable(pe, EEH_OPT_THAW_DMA);
- if (ret) {
- pr_warn("%s: Failure %d enabling DMA on PHB#%x-PE#%x\n",
- __func__, ret, pe->phb->global_number, pe->addr);
- return ret;
- }
- return ret;
- }
- static struct pci_device_id eeh_reset_ids[] = {
- { PCI_DEVICE(0x19a2, 0x0710) }, /* Emulex, BE */
- { PCI_DEVICE(0x10df, 0xe220) }, /* Emulex, Lancer */
- { PCI_DEVICE(0x14e4, 0x1657) }, /* Broadcom BCM5719 */
- { 0 }
- };
- static int eeh_pe_change_owner(struct eeh_pe *pe)
- {
- struct eeh_dev *edev, *tmp;
- struct pci_dev *pdev;
- struct pci_device_id *id;
- int ret;
- /* Check PE state */
- ret = eeh_ops->get_state(pe, NULL);
- if (ret < 0 || ret == EEH_STATE_NOT_SUPPORT)
- return 0;
- /* Unfrozen PE, nothing to do */
- if (eeh_state_active(ret))
- return 0;
- /* Frozen PE, check if it needs PE level reset */
- eeh_pe_for_each_dev(pe, edev, tmp) {
- pdev = eeh_dev_to_pci_dev(edev);
- if (!pdev)
- continue;
- for (id = &eeh_reset_ids[0]; id->vendor != 0; id++) {
- if (id->vendor != PCI_ANY_ID &&
- id->vendor != pdev->vendor)
- continue;
- if (id->device != PCI_ANY_ID &&
- id->device != pdev->device)
- continue;
- if (id->subvendor != PCI_ANY_ID &&
- id->subvendor != pdev->subsystem_vendor)
- continue;
- if (id->subdevice != PCI_ANY_ID &&
- id->subdevice != pdev->subsystem_device)
- continue;
- return eeh_pe_reset_and_recover(pe);
- }
- }
- ret = eeh_unfreeze_pe(pe);
- if (!ret)
- eeh_pe_state_clear(pe, EEH_PE_ISOLATED, true);
- return ret;
- }
- /**
- * eeh_dev_open - Increase count of pass through devices for PE
- * @pdev: PCI device
- *
- * Increase count of passed through devices for the indicated
- * PE. In the result, the EEH errors detected on the PE won't be
- * reported. The PE owner will be responsible for detection
- * and recovery.
- */
- int eeh_dev_open(struct pci_dev *pdev)
- {
- struct eeh_dev *edev;
- int ret = -ENODEV;
- mutex_lock(&eeh_dev_mutex);
- /* No PCI device ? */
- if (!pdev)
- goto out;
- /* No EEH device or PE ? */
- edev = pci_dev_to_eeh_dev(pdev);
- if (!edev || !edev->pe)
- goto out;
- /*
- * The PE might have been put into frozen state, but we
- * didn't detect that yet. The passed through PCI devices
- * in frozen PE won't work properly. Clear the frozen state
- * in advance.
- */
- ret = eeh_pe_change_owner(edev->pe);
- if (ret)
- goto out;
- /* Increase PE's pass through count */
- atomic_inc(&edev->pe->pass_dev_cnt);
- mutex_unlock(&eeh_dev_mutex);
- return 0;
- out:
- mutex_unlock(&eeh_dev_mutex);
- return ret;
- }
- EXPORT_SYMBOL_GPL(eeh_dev_open);
- /**
- * eeh_dev_release - Decrease count of pass through devices for PE
- * @pdev: PCI device
- *
- * Decrease count of pass through devices for the indicated PE. If
- * there is no passed through device in PE, the EEH errors detected
- * on the PE will be reported and handled as usual.
- */
- void eeh_dev_release(struct pci_dev *pdev)
- {
- struct eeh_dev *edev;
- mutex_lock(&eeh_dev_mutex);
- /* No PCI device ? */
- if (!pdev)
- goto out;
- /* No EEH device ? */
- edev = pci_dev_to_eeh_dev(pdev);
- if (!edev || !edev->pe || !eeh_pe_passed(edev->pe))
- goto out;
- /* Decrease PE's pass through count */
- WARN_ON(atomic_dec_if_positive(&edev->pe->pass_dev_cnt) < 0);
- eeh_pe_change_owner(edev->pe);
- out:
- mutex_unlock(&eeh_dev_mutex);
- }
- EXPORT_SYMBOL(eeh_dev_release);
- #ifdef CONFIG_IOMMU_API
- static int dev_has_iommu_table(struct device *dev, void *data)
- {
- struct pci_dev *pdev = to_pci_dev(dev);
- struct pci_dev **ppdev = data;
- if (!dev)
- return 0;
- if (device_iommu_mapped(dev)) {
- *ppdev = pdev;
- return 1;
- }
- return 0;
- }
- /**
- * eeh_iommu_group_to_pe - Convert IOMMU group to EEH PE
- * @group: IOMMU group
- *
- * The routine is called to convert IOMMU group to EEH PE.
- */
- struct eeh_pe *eeh_iommu_group_to_pe(struct iommu_group *group)
- {
- struct pci_dev *pdev = NULL;
- struct eeh_dev *edev;
- int ret;
- /* No IOMMU group ? */
- if (!group)
- return NULL;
- ret = iommu_group_for_each_dev(group, &pdev, dev_has_iommu_table);
- if (!ret || !pdev)
- return NULL;
- /* No EEH device or PE ? */
- edev = pci_dev_to_eeh_dev(pdev);
- if (!edev || !edev->pe)
- return NULL;
- return edev->pe;
- }
- EXPORT_SYMBOL_GPL(eeh_iommu_group_to_pe);
- #endif /* CONFIG_IOMMU_API */
- /**
- * eeh_pe_set_option - Set options for the indicated PE
- * @pe: EEH PE
- * @option: requested option
- *
- * The routine is called to enable or disable EEH functionality
- * on the indicated PE, to enable IO or DMA for the frozen PE.
- */
- int eeh_pe_set_option(struct eeh_pe *pe, int option)
- {
- int ret = 0;
- /* Invalid PE ? */
- if (!pe)
- return -ENODEV;
- /*
- * EEH functionality could possibly be disabled, just
- * return error for the case. And the EEH functionality
- * isn't expected to be disabled on one specific PE.
- */
- switch (option) {
- case EEH_OPT_ENABLE:
- if (eeh_enabled()) {
- ret = eeh_pe_change_owner(pe);
- break;
- }
- ret = -EIO;
- break;
- case EEH_OPT_DISABLE:
- break;
- case EEH_OPT_THAW_MMIO:
- case EEH_OPT_THAW_DMA:
- case EEH_OPT_FREEZE_PE:
- if (!eeh_ops || !eeh_ops->set_option) {
- ret = -ENOENT;
- break;
- }
- ret = eeh_pci_enable(pe, option);
- break;
- default:
- pr_debug("%s: Option %d out of range (%d, %d)\n",
- __func__, option, EEH_OPT_DISABLE, EEH_OPT_THAW_DMA);
- ret = -EINVAL;
- }
- return ret;
- }
- EXPORT_SYMBOL_GPL(eeh_pe_set_option);
- /**
- * eeh_pe_get_state - Retrieve PE's state
- * @pe: EEH PE
- *
- * Retrieve the PE's state, which includes 3 aspects: enabled
- * DMA, enabled IO and asserted reset.
- */
- int eeh_pe_get_state(struct eeh_pe *pe)
- {
- int result, ret = 0;
- bool rst_active, dma_en, mmio_en;
- /* Existing PE ? */
- if (!pe)
- return -ENODEV;
- if (!eeh_ops || !eeh_ops->get_state)
- return -ENOENT;
- /*
- * If the parent PE is owned by the host kernel and is undergoing
- * error recovery, we should return the PE state as temporarily
- * unavailable so that the error recovery on the guest is suspended
- * until the recovery completes on the host.
- */
- if (pe->parent &&
- !(pe->state & EEH_PE_REMOVED) &&
- (pe->parent->state & (EEH_PE_ISOLATED | EEH_PE_RECOVERING)))
- return EEH_PE_STATE_UNAVAIL;
- result = eeh_ops->get_state(pe, NULL);
- rst_active = !!(result & EEH_STATE_RESET_ACTIVE);
- dma_en = !!(result & EEH_STATE_DMA_ENABLED);
- mmio_en = !!(result & EEH_STATE_MMIO_ENABLED);
- if (rst_active)
- ret = EEH_PE_STATE_RESET;
- else if (dma_en && mmio_en)
- ret = EEH_PE_STATE_NORMAL;
- else if (!dma_en && !mmio_en)
- ret = EEH_PE_STATE_STOPPED_IO_DMA;
- else if (!dma_en && mmio_en)
- ret = EEH_PE_STATE_STOPPED_DMA;
- else
- ret = EEH_PE_STATE_UNAVAIL;
- return ret;
- }
- EXPORT_SYMBOL_GPL(eeh_pe_get_state);
- static int eeh_pe_reenable_devices(struct eeh_pe *pe, bool include_passed)
- {
- struct eeh_dev *edev, *tmp;
- struct pci_dev *pdev;
- int ret = 0;
- eeh_pe_restore_bars(pe);
- /*
- * Reenable PCI devices as the devices passed
- * through are always enabled before the reset.
- */
- eeh_pe_for_each_dev(pe, edev, tmp) {
- pdev = eeh_dev_to_pci_dev(edev);
- if (!pdev)
- continue;
- ret = pci_reenable_device(pdev);
- if (ret) {
- pr_warn("%s: Failure %d reenabling %s\n",
- __func__, ret, pci_name(pdev));
- return ret;
- }
- }
- /* The PE is still in frozen state */
- if (include_passed || !eeh_pe_passed(pe)) {
- ret = eeh_unfreeze_pe(pe);
- } else
- pr_info("EEH: Note: Leaving passthrough PHB#%x-PE#%x frozen.\n",
- pe->phb->global_number, pe->addr);
- if (!ret)
- eeh_pe_state_clear(pe, EEH_PE_ISOLATED, include_passed);
- return ret;
- }
- /**
- * eeh_pe_reset - Issue PE reset according to specified type
- * @pe: EEH PE
- * @option: reset type
- * @include_passed: include passed-through devices?
- *
- * The routine is called to reset the specified PE with the
- * indicated type, either fundamental reset or hot reset.
- * PE reset is the most important part for error recovery.
- */
- int eeh_pe_reset(struct eeh_pe *pe, int option, bool include_passed)
- {
- int ret = 0;
- /* Invalid PE ? */
- if (!pe)
- return -ENODEV;
- if (!eeh_ops || !eeh_ops->set_option || !eeh_ops->reset)
- return -ENOENT;
- switch (option) {
- case EEH_RESET_DEACTIVATE:
- ret = eeh_ops->reset(pe, option);
- eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, include_passed);
- if (ret)
- break;
- ret = eeh_pe_reenable_devices(pe, include_passed);
- break;
- case EEH_RESET_HOT:
- case EEH_RESET_FUNDAMENTAL:
- /*
- * Proactively freeze the PE to drop all MMIO access
- * during reset, which should be banned as it's always
- * cause recursive EEH error.
- */
- eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE);
- eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED);
- ret = eeh_ops->reset(pe, option);
- break;
- default:
- pr_debug("%s: Unsupported option %d\n",
- __func__, option);
- ret = -EINVAL;
- }
- return ret;
- }
- EXPORT_SYMBOL_GPL(eeh_pe_reset);
- /**
- * eeh_pe_configure - Configure PCI bridges after PE reset
- * @pe: EEH PE
- *
- * The routine is called to restore the PCI config space for
- * those PCI devices, especially PCI bridges affected by PE
- * reset issued previously.
- */
- int eeh_pe_configure(struct eeh_pe *pe)
- {
- int ret = 0;
- /* Invalid PE ? */
- if (!pe)
- return -ENODEV;
- return ret;
- }
- EXPORT_SYMBOL_GPL(eeh_pe_configure);
- /**
- * eeh_pe_inject_err - Injecting the specified PCI error to the indicated PE
- * @pe: the indicated PE
- * @type: error type
- * @func: error function
- * @addr: address
- * @mask: address mask
- *
- * The routine is called to inject the specified PCI error, which
- * is determined by @type and @func, to the indicated PE for
- * testing purpose.
- */
- int eeh_pe_inject_err(struct eeh_pe *pe, int type, int func,
- unsigned long addr, unsigned long mask)
- {
- /* Invalid PE ? */
- if (!pe)
- return -ENODEV;
- /* Unsupported operation ? */
- if (!eeh_ops || !eeh_ops->err_inject)
- return -ENOENT;
- /* Check on PCI error type */
- if (type != EEH_ERR_TYPE_32 && type != EEH_ERR_TYPE_64)
- return -EINVAL;
- /* Check on PCI error function */
- if (func < EEH_ERR_FUNC_MIN || func > EEH_ERR_FUNC_MAX)
- return -EINVAL;
- return eeh_ops->err_inject(pe, type, func, addr, mask);
- }
- EXPORT_SYMBOL_GPL(eeh_pe_inject_err);
- #ifdef CONFIG_PROC_FS
- static int proc_eeh_show(struct seq_file *m, void *v)
- {
- if (!eeh_enabled()) {
- seq_printf(m, "EEH Subsystem is globally disabled\n");
- seq_printf(m, "eeh_total_mmio_ffs=%llu\n", eeh_stats.total_mmio_ffs);
- } else {
- seq_printf(m, "EEH Subsystem is enabled\n");
- seq_printf(m,
- "no device=%llu\n"
- "no device node=%llu\n"
- "no config address=%llu\n"
- "check not wanted=%llu\n"
- "eeh_total_mmio_ffs=%llu\n"
- "eeh_false_positives=%llu\n"
- "eeh_slot_resets=%llu\n",
- eeh_stats.no_device,
- eeh_stats.no_dn,
- eeh_stats.no_cfg_addr,
- eeh_stats.ignored_check,
- eeh_stats.total_mmio_ffs,
- eeh_stats.false_positives,
- eeh_stats.slot_resets);
- }
- return 0;
- }
- #endif /* CONFIG_PROC_FS */
- #ifdef CONFIG_DEBUG_FS
- static struct pci_dev *eeh_debug_lookup_pdev(struct file *filp,
- const char __user *user_buf,
- size_t count, loff_t *ppos)
- {
- uint32_t domain, bus, dev, fn;
- struct pci_dev *pdev;
- char buf[20];
- int ret;
- memset(buf, 0, sizeof(buf));
- ret = simple_write_to_buffer(buf, sizeof(buf)-1, ppos, user_buf, count);
- if (!ret)
- return ERR_PTR(-EFAULT);
- ret = sscanf(buf, "%x:%x:%x.%x", &domain, &bus, &dev, &fn);
- if (ret != 4) {
- pr_err("%s: expected 4 args, got %d\n", __func__, ret);
- return ERR_PTR(-EINVAL);
- }
- pdev = pci_get_domain_bus_and_slot(domain, bus, (dev << 3) | fn);
- if (!pdev)
- return ERR_PTR(-ENODEV);
- return pdev;
- }
- static int eeh_enable_dbgfs_set(void *data, u64 val)
- {
- if (val)
- eeh_clear_flag(EEH_FORCE_DISABLED);
- else
- eeh_add_flag(EEH_FORCE_DISABLED);
- return 0;
- }
- static int eeh_enable_dbgfs_get(void *data, u64 *val)
- {
- if (eeh_enabled())
- *val = 0x1ul;
- else
- *val = 0x0ul;
- return 0;
- }
- DEFINE_DEBUGFS_ATTRIBUTE(eeh_enable_dbgfs_ops, eeh_enable_dbgfs_get,
- eeh_enable_dbgfs_set, "0x%llx\n");
- static ssize_t eeh_force_recover_write(struct file *filp,
- const char __user *user_buf,
- size_t count, loff_t *ppos)
- {
- struct pci_controller *hose;
- uint32_t phbid, pe_no;
- struct eeh_pe *pe;
- char buf[20];
- int ret;
- ret = simple_write_to_buffer(buf, sizeof(buf), ppos, user_buf, count);
- if (!ret)
- return -EFAULT;
- /*
- * When PE is NULL the event is a "special" event. Rather than
- * recovering a specific PE it forces the EEH core to scan for failed
- * PHBs and recovers each. This needs to be done before any device
- * recoveries can occur.
- */
- if (!strncmp(buf, "hwcheck", 7)) {
- __eeh_send_failure_event(NULL);
- return count;
- }
- ret = sscanf(buf, "%x:%x", &phbid, &pe_no);
- if (ret != 2)
- return -EINVAL;
- hose = pci_find_controller_for_domain(phbid);
- if (!hose)
- return -ENODEV;
- /* Retrieve PE */
- pe = eeh_pe_get(hose, pe_no);
- if (!pe)
- return -ENODEV;
- /*
- * We don't do any state checking here since the detection
- * process is async to the recovery process. The recovery
- * thread *should* not break even if we schedule a recovery
- * from an odd state (e.g. PE removed, or recovery of a
- * non-isolated PE)
- */
- __eeh_send_failure_event(pe);
- return ret < 0 ? ret : count;
- }
- static const struct file_operations eeh_force_recover_fops = {
- .open = simple_open,
- .llseek = no_llseek,
- .write = eeh_force_recover_write,
- };
- static ssize_t eeh_debugfs_dev_usage(struct file *filp,
- char __user *user_buf,
- size_t count, loff_t *ppos)
- {
- static const char usage[] = "input format: <domain>:<bus>:<dev>.<fn>\n";
- return simple_read_from_buffer(user_buf, count, ppos,
- usage, sizeof(usage) - 1);
- }
- static ssize_t eeh_dev_check_write(struct file *filp,
- const char __user *user_buf,
- size_t count, loff_t *ppos)
- {
- struct pci_dev *pdev;
- struct eeh_dev *edev;
- int ret;
- pdev = eeh_debug_lookup_pdev(filp, user_buf, count, ppos);
- if (IS_ERR(pdev))
- return PTR_ERR(pdev);
- edev = pci_dev_to_eeh_dev(pdev);
- if (!edev) {
- pci_err(pdev, "No eeh_dev for this device!\n");
- pci_dev_put(pdev);
- return -ENODEV;
- }
- ret = eeh_dev_check_failure(edev);
- pci_info(pdev, "eeh_dev_check_failure(%s) = %d\n",
- pci_name(pdev), ret);
- pci_dev_put(pdev);
- return count;
- }
- static const struct file_operations eeh_dev_check_fops = {
- .open = simple_open,
- .llseek = no_llseek,
- .write = eeh_dev_check_write,
- .read = eeh_debugfs_dev_usage,
- };
- static int eeh_debugfs_break_device(struct pci_dev *pdev)
- {
- struct resource *bar = NULL;
- void __iomem *mapped;
- u16 old, bit;
- int i, pos;
- /* Do we have an MMIO BAR to disable? */
- for (i = 0; i <= PCI_STD_RESOURCE_END; i++) {
- struct resource *r = &pdev->resource[i];
- if (!r->flags || !r->start)
- continue;
- if (r->flags & IORESOURCE_IO)
- continue;
- if (r->flags & IORESOURCE_UNSET)
- continue;
- bar = r;
- break;
- }
- if (!bar) {
- pci_err(pdev, "Unable to find Memory BAR to cause EEH with\n");
- return -ENXIO;
- }
- pci_err(pdev, "Going to break: %pR\n", bar);
- if (pdev->is_virtfn) {
- #ifndef CONFIG_PCI_IOV
- return -ENXIO;
- #else
- /*
- * VFs don't have a per-function COMMAND register, so the best
- * we can do is clear the Memory Space Enable bit in the PF's
- * SRIOV control reg.
- *
- * Unfortunately, this requires that we have a PF (i.e doesn't
- * work for a passed-through VF) and it has the potential side
- * effect of also causing an EEH on every other VF under the
- * PF. Oh well.
- */
- pdev = pdev->physfn;
- if (!pdev)
- return -ENXIO; /* passed through VFs have no PF */
- pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_SRIOV);
- pos += PCI_SRIOV_CTRL;
- bit = PCI_SRIOV_CTRL_MSE;
- #endif /* !CONFIG_PCI_IOV */
- } else {
- bit = PCI_COMMAND_MEMORY;
- pos = PCI_COMMAND;
- }
- /*
- * Process here is:
- *
- * 1. Disable Memory space.
- *
- * 2. Perform an MMIO to the device. This should result in an error
- * (CA / UR) being raised by the device which results in an EEH
- * PE freeze. Using the in_8() accessor skips the eeh detection hook
- * so the freeze hook so the EEH Detection machinery won't be
- * triggered here. This is to match the usual behaviour of EEH
- * where the HW will asynchronously freeze a PE and it's up to
- * the kernel to notice and deal with it.
- *
- * 3. Turn Memory space back on. This is more important for VFs
- * since recovery will probably fail if we don't. For normal
- * the COMMAND register is reset as a part of re-initialising
- * the device.
- *
- * Breaking stuff is the point so who cares if it's racy ;)
- */
- pci_read_config_word(pdev, pos, &old);
- mapped = ioremap(bar->start, PAGE_SIZE);
- if (!mapped) {
- pci_err(pdev, "Unable to map MMIO BAR %pR\n", bar);
- return -ENXIO;
- }
- pci_write_config_word(pdev, pos, old & ~bit);
- in_8(mapped);
- pci_write_config_word(pdev, pos, old);
- iounmap(mapped);
- return 0;
- }
- static ssize_t eeh_dev_break_write(struct file *filp,
- const char __user *user_buf,
- size_t count, loff_t *ppos)
- {
- struct pci_dev *pdev;
- int ret;
- pdev = eeh_debug_lookup_pdev(filp, user_buf, count, ppos);
- if (IS_ERR(pdev))
- return PTR_ERR(pdev);
- ret = eeh_debugfs_break_device(pdev);
- pci_dev_put(pdev);
- if (ret < 0)
- return ret;
- return count;
- }
- static const struct file_operations eeh_dev_break_fops = {
- .open = simple_open,
- .llseek = no_llseek,
- .write = eeh_dev_break_write,
- .read = eeh_debugfs_dev_usage,
- };
- static ssize_t eeh_dev_can_recover(struct file *filp,
- const char __user *user_buf,
- size_t count, loff_t *ppos)
- {
- struct pci_driver *drv;
- struct pci_dev *pdev;
- size_t ret;
- pdev = eeh_debug_lookup_pdev(filp, user_buf, count, ppos);
- if (IS_ERR(pdev))
- return PTR_ERR(pdev);
- /*
- * In order for error recovery to work the driver needs to implement
- * .error_detected(), so it can quiesce IO to the device, and
- * .slot_reset() so it can re-initialise the device after a reset.
- *
- * Ideally they'd implement .resume() too, but some drivers which
- * we need to support (notably IPR) don't so I guess we can tolerate
- * that.
- *
- * .mmio_enabled() is mostly there as a work-around for devices which
- * take forever to re-init after a hot reset. Implementing that is
- * strictly optional.
- */
- drv = pci_dev_driver(pdev);
- if (drv &&
- drv->err_handler &&
- drv->err_handler->error_detected &&
- drv->err_handler->slot_reset) {
- ret = count;
- } else {
- ret = -EOPNOTSUPP;
- }
- pci_dev_put(pdev);
- return ret;
- }
- static const struct file_operations eeh_dev_can_recover_fops = {
- .open = simple_open,
- .llseek = no_llseek,
- .write = eeh_dev_can_recover,
- .read = eeh_debugfs_dev_usage,
- };
- #endif
- static int __init eeh_init_proc(void)
- {
- if (machine_is(pseries) || machine_is(powernv)) {
- proc_create_single("powerpc/eeh", 0, NULL, proc_eeh_show);
- #ifdef CONFIG_DEBUG_FS
- debugfs_create_file_unsafe("eeh_enable", 0600,
- arch_debugfs_dir, NULL,
- &eeh_enable_dbgfs_ops);
- debugfs_create_u32("eeh_max_freezes", 0600,
- arch_debugfs_dir, &eeh_max_freezes);
- debugfs_create_bool("eeh_disable_recovery", 0600,
- arch_debugfs_dir,
- &eeh_debugfs_no_recover);
- debugfs_create_file_unsafe("eeh_dev_check", 0600,
- arch_debugfs_dir, NULL,
- &eeh_dev_check_fops);
- debugfs_create_file_unsafe("eeh_dev_break", 0600,
- arch_debugfs_dir, NULL,
- &eeh_dev_break_fops);
- debugfs_create_file_unsafe("eeh_force_recover", 0600,
- arch_debugfs_dir, NULL,
- &eeh_force_recover_fops);
- debugfs_create_file_unsafe("eeh_dev_can_recover", 0600,
- arch_debugfs_dir, NULL,
- &eeh_dev_can_recover_fops);
- eeh_cache_debugfs_init();
- #endif
- }
- return 0;
- }
- __initcall(eeh_init_proc);
|