/* * Copyright IBM Corporation 2001, 2005, 2006 * Copyright Dave Engebretsen & Todd Inglett 2001 * Copyright Linas Vepstas 2005, 2006 * Copyright 2001-2012 IBM Corporation. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * Please address comments and feedback to Linas Vepstas */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /** Overview: * EEH, or "Extended 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); /* 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); /* 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 4096 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; #define IS_BRIDGE(class_code) (((class_code)<<16) == PCI_BASE_CLASS_BRIDGE) static int __init eeh_setup(char *str) { if (!strcmp(str, "off")) eeh_add_flag(EEH_FORCE_DISABLED); return 1; } __setup("eeh=", eeh_setup); /** * eeh_gather_pci_data - Copy assorted PCI config space registers to buff * @edev: device to report data for * @buf: point to buffer in which to log * @len: amount of room in buffer * * This routine captures assorted PCI configuration space data, * and puts them into a buffer for RTAS error logging. */ static size_t eeh_gather_pci_data(struct eeh_dev *edev, char *buf, size_t len) { struct device_node *dn = eeh_dev_to_of_node(edev); u32 cfg; int cap, i; int n = 0, l = 0; char buffer[128]; n += scnprintf(buf+n, len-n, "%s\n", dn->full_name); pr_warn("EEH: of node=%s\n", dn->full_name); eeh_ops->read_config(dn, 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(dn, 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(dn, 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(dn, 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(dn, 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(dn, 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(dn, 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(dn, 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; } /** * 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; struct eeh_dev *edev, *tmp; /* * 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. */ if (!(pe->type & EEH_PE_PHB)) { if (eeh_has_flag(EEH_ENABLE_IO_FOR_LOG)) eeh_pci_enable(pe, EEH_OPT_THAW_MMIO); eeh_ops->configure_bridge(pe); eeh_pe_restore_bars(pe); pci_regs_buf[0] = 0; eeh_pe_for_each_dev(pe, edev, tmp) { loglen += eeh_gather_pci_data(edev, pci_regs_buf + loglen, EEH_PCI_REGS_LOG_LEN - 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) { pte_t *ptep; unsigned long pa; int hugepage_shift; /* * We won't find hugepages here, iomem */ ptep = find_linux_pte_or_hugepte(init_mm.pgd, token, &hugepage_shift); if (!ptep) return token; WARN_ON(hugepage_shift); pa = pte_pfn(*ptep) << PAGE_SHIFT; return pa | (token & (PAGE_SIZE-1)); } /* * 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#%d\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) || (ret & (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) == (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) { ret = 0; goto out; } /* Isolate the PHB and send event */ eeh_pe_state_mark(phb_pe, EEH_PE_ISOLATED); eeh_serialize_unlock(flags); pr_err("EEH: PHB#%x failure detected, location: %s\n", phb_pe->phb->global_number, eeh_pe_loc_get(phb_pe)); dump_stack(); eeh_send_failure_event(phb_pe); return 1; out: eeh_serialize_unlock(flags); return ret; } /** * 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; int active_flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE); unsigned long flags; struct device_node *dn; struct pci_dev *dev; struct eeh_pe *pe, *parent_pe, *phb_pe; int rc = 0; const char *location; eeh_stats.total_mmio_ffs++; if (!eeh_enabled()) return 0; if (!edev) { eeh_stats.no_dn++; return 0; } dn = eeh_dev_to_of_node(edev); 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++; pr_debug("EEH: Ignored check for %s %s\n", eeh_pci_name(dev), dn->full_name); return 0; } if (!pe->addr && !pe->config_addr) { eeh_stats.no_cfg_addr++; 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 == 0) { location = of_get_property(dn, "ibm,loc-code", NULL); printk(KERN_ERR "EEH: %d reads ignored for recovering device at " "location=%s driver=%s pci addr=%s\n", pe->check_count, location, eeh_driver_name(dev), eeh_pci_name(dev)); printk(KERN_ERR "EEH: 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) || ((ret & active_flags) == active_flags)) { 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 && (ret & active_flags) != active_flags) pe = parent_pe; /* 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_state_mark(pe, EEH_PE_ISOLATED); 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. */ phb_pe = eeh_phb_pe_get(pe->phb); pr_err("EEH: Frozen PHB#%x-PE#%x detected\n", pe->phb->global_number, pe->addr); pr_err("EEH: PE location: %s, PHB location: %s\n", eeh_pe_loc_get(pe), eeh_pe_loc_get(phb_pe)); dump_stack(); 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 * * 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; 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#%d-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_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); if (rc <= 0) return rc; if (rc & active_flag) return 0; return -EIO; } return rc; } /** * pcibios_set_pcie_slot_reset - 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_pe_state_clear(pe, EEH_PE_RESET); break; case pcie_hot_reset: eeh_pe_state_mark(pe, EEH_PE_RESET); eeh_ops->reset(pe, EEH_RESET_HOT); break; case pcie_warm_reset: eeh_pe_state_mark(pe, EEH_PE_RESET); eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL); break; default: eeh_pe_state_clear(pe, EEH_PE_RESET); return -EINVAL; }; return 0; } /** * eeh_set_pe_freset - Check the required reset for the indicated device * @data: 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(void *data, void *flag) { struct pci_dev *dev; unsigned int *freset = (unsigned int *)flag; struct eeh_dev *edev = (struct eeh_dev *)data; dev = eeh_dev_to_pci_dev(edev); if (dev) *freset |= dev->needs_freset; return NULL; } /** * eeh_reset_pe_once - Assert the pci #RST line for 1/4 second * @pe: EEH PE * * Assert the PCI #RST line for 1/4 second. */ static void eeh_reset_pe_once(struct eeh_pe *pe) { unsigned int freset = 0; /* Determine type of EEH reset required for * Partitionable Endpoint, a hot-reset (1) * or a fundamental reset (3). * A fundamental reset required by any device under * Partitionable Endpoint trumps hot-reset. */ eeh_pe_dev_traverse(pe, eeh_set_dev_freset, &freset); if (freset) eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL); else eeh_ops->reset(pe, EEH_RESET_HOT); eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); } /** * eeh_reset_pe - Reset the indicated PE * @pe: EEH PE * * This routine should be called to reset indicated device, including * PE. A PE might include multiple PCI devices and sometimes PCI bridges * might be involved as well. */ int eeh_reset_pe(struct eeh_pe *pe) { int flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE); int i, rc; /* Take three shots at resetting the bus */ for (i=0; i<3; i++) { eeh_reset_pe_once(pe); /* * EEH_PE_ISOLATED is expected to be removed after * BAR restore. */ rc = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); if ((rc & flags) == flags) return 0; if (rc < 0) { pr_err("%s: Unrecoverable slot failure on PHB#%d-PE#%x", __func__, pe->phb->global_number, pe->addr); return -1; } pr_err("EEH: bus reset %d failed on PHB#%d-PE#%x, rc=%d\n", i+1, pe->phb->global_number, pe->addr, rc); } return -1; } /** * 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; struct device_node *dn; if (!edev) return; dn = eeh_dev_to_of_node(edev); for (i = 0; i < 16; i++) eeh_ops->read_config(dn, 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; } /** * eeh_ops_register - Register platform dependent EEH operations * @ops: platform dependent EEH operations * * Register the platform dependent EEH operation callback * functions. The platform should call this function before * any other EEH operations. */ int __init eeh_ops_register(struct eeh_ops *ops) { if (!ops->name) { pr_warn("%s: Invalid EEH ops name for %p\n", __func__, ops); return -EINVAL; } if (eeh_ops && eeh_ops != ops) { pr_warn("%s: EEH ops of platform %s already existing (%s)\n", __func__, eeh_ops->name, ops->name); return -EEXIST; } eeh_ops = ops; return 0; } /** * eeh_ops_unregister - Unreigster platform dependent EEH operations * @name: name of EEH platform operations * * Unregister the platform dependent EEH operation callback * functions. */ int __exit eeh_ops_unregister(const char *name) { if (!name || !strlen(name)) { pr_warn("%s: Invalid EEH ops name\n", __func__); return -EINVAL; } if (eeh_ops && !strcmp(eeh_ops->name, name)) { eeh_ops = NULL; return 0; } return -EEXIST; } 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, }; /** * eeh_init - EEH initialization * * Initialize EEH by trying to enable it for all of the adapters in the system. * As a side effect we can determine here if eeh is supported at all. * Note that we leave EEH on so failed config cycles won't cause a machine * check. If a user turns off EEH for a particular adapter they are really * telling Linux to ignore errors. Some hardware (e.g. POWER5) won't * grant access to a slot if EEH isn't enabled, and so we always enable * EEH for all slots/all devices. * * The eeh-force-off option disables EEH checking globally, for all slots. * Even if force-off is set, the EEH hardware is still enabled, so that * newer systems can boot. */ int eeh_init(void) { struct pci_controller *hose, *tmp; struct device_node *phb; static int cnt = 0; int ret = 0; /* * We have to delay the initialization on PowerNV after * the PCI hierarchy tree has been built because the PEs * are figured out based on PCI devices instead of device * tree nodes */ if (machine_is(powernv) && cnt++ <= 0) return ret; /* Register reboot notifier */ ret = register_reboot_notifier(&eeh_reboot_nb); if (ret) { pr_warn("%s: Failed to register notifier (%d)\n", __func__, ret); return ret; } /* call platform initialization function */ if (!eeh_ops) { pr_warn("%s: Platform EEH operation not found\n", __func__); return -EEXIST; } else if ((ret = eeh_ops->init())) { pr_warn("%s: Failed to call platform init function (%d)\n", __func__, ret); return ret; } /* Initialize EEH event */ ret = eeh_event_init(); if (ret) return ret; /* Enable EEH for all adapters */ if (eeh_has_flag(EEH_PROBE_MODE_DEVTREE)) { list_for_each_entry_safe(hose, tmp, &hose_list, list_node) { phb = hose->dn; traverse_pci_devices(phb, eeh_ops->of_probe, NULL); } } else if (eeh_has_flag(EEH_PROBE_MODE_DEV)) { list_for_each_entry_safe(hose, tmp, &hose_list, list_node) pci_walk_bus(hose->bus, eeh_ops->dev_probe, NULL); } else { pr_warn("%s: Invalid probe mode %x", __func__, eeh_subsystem_flags); return -EINVAL; } /* * Call platform post-initialization. Actually, It's good chance * to inform platform that EEH is ready to supply service if the * I/O cache stuff has been built up. */ if (eeh_ops->post_init) { ret = eeh_ops->post_init(); if (ret) return ret; } if (eeh_enabled()) pr_info("EEH: PCI Enhanced I/O Error Handling Enabled\n"); else pr_warn("EEH: No capable adapters found\n"); return ret; } core_initcall_sync(eeh_init); /** * eeh_add_device_early - Enable EEH for the indicated device_node * @dn: device node for which to set up EEH * * This routine must be used to perform EEH initialization for PCI * devices that were added after system boot (e.g. hotplug, dlpar). * This routine must be called before any i/o is performed to the * adapter (inluding any config-space i/o). * Whether this actually enables EEH or not for this device depends * on the CEC architecture, type of the device, on earlier boot * command-line arguments & etc. */ void eeh_add_device_early(struct device_node *dn) { struct pci_controller *phb; /* * If we're doing EEH probe based on PCI device, we * would delay the probe until late stage because * the PCI device isn't available this moment. */ if (!eeh_has_flag(EEH_PROBE_MODE_DEVTREE)) return; if (!of_node_to_eeh_dev(dn)) return; phb = of_node_to_eeh_dev(dn)->phb; /* USB Bus children of PCI devices will not have BUID's */ if (NULL == phb || 0 == phb->buid) return; eeh_ops->of_probe(dn, NULL); } /** * eeh_add_device_tree_early - Enable EEH for the indicated device * @dn: device node * * This routine must be used to perform EEH initialization for the * indicated PCI device that was added after system boot (e.g. * hotplug, dlpar). */ void eeh_add_device_tree_early(struct device_node *dn) { struct device_node *sib; for_each_child_of_node(dn, sib) eeh_add_device_tree_early(sib); eeh_add_device_early(dn); } EXPORT_SYMBOL_GPL(eeh_add_device_tree_early); /** * eeh_add_device_late - 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_add_device_late(struct pci_dev *dev) { struct device_node *dn; struct eeh_dev *edev; if (!dev || !eeh_enabled()) return; pr_debug("EEH: Adding device %s\n", pci_name(dev)); dn = pci_device_to_OF_node(dev); edev = of_node_to_eeh_dev(dn); if (edev->pdev == dev) { pr_debug("EEH: Already referenced !\n"); return; } /* * The EEH cache might not be removed correctly because of * unbalanced kref to the device during unplug time, which * relies on pcibios_release_device(). So we have to remove * that here explicitly. */ if (edev->pdev) { eeh_rmv_from_parent_pe(edev); eeh_addr_cache_rmv_dev(edev->pdev); eeh_sysfs_remove_device(edev->pdev); edev->mode &= ~EEH_DEV_SYSFS; /* * 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; edev->pdev = NULL; dev->dev.archdata.edev = NULL; } edev->pdev = dev; dev->dev.archdata.edev = edev; /* * We have to do the EEH probe here because the PCI device * hasn't been created yet in the early stage. */ if (eeh_has_flag(EEH_PROBE_MODE_DEV)) eeh_ops->dev_probe(dev, NULL); eeh_addr_cache_insert_dev(dev); } /** * eeh_add_device_tree_late - Perform EEH initialization for the indicated PCI bus * @bus: PCI bus * * This routine must be used to perform EEH initialization for PCI * devices which are attached to the indicated PCI bus. The PCI bus * is added after system boot through hotplug or dlpar. */ void eeh_add_device_tree_late(struct pci_bus *bus) { struct pci_dev *dev; list_for_each_entry(dev, &bus->devices, bus_list) { eeh_add_device_late(dev); if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { struct pci_bus *subbus = dev->subordinate; if (subbus) eeh_add_device_tree_late(subbus); } } } EXPORT_SYMBOL_GPL(eeh_add_device_tree_late); /** * eeh_add_sysfs_files - Add EEH sysfs files for the indicated PCI bus * @bus: PCI bus * * This routine must be used to add EEH sysfs files for PCI * devices which are attached to the indicated PCI bus. The PCI bus * is added after system boot through hotplug or dlpar. */ void eeh_add_sysfs_files(struct pci_bus *bus) { struct pci_dev *dev; list_for_each_entry(dev, &bus->devices, bus_list) { eeh_sysfs_add_device(dev); if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { struct pci_bus *subbus = dev->subordinate; if (subbus) eeh_add_sysfs_files(subbus); } } } EXPORT_SYMBOL_GPL(eeh_add_sysfs_files); /** * 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 */ pr_debug("EEH: Removing device %s\n", pci_name(dev)); if (!edev || !edev->pdev || !edev->pe) { pr_debug("EEH: 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; dev->dev.archdata.edev = NULL; if (!(edev->pe->state & EEH_PE_KEEP)) eeh_rmv_from_parent_pe(edev); else edev->mode |= EEH_DEV_DISCONNECTED; /* * 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); eeh_sysfs_remove_device(dev); edev->mode &= ~EEH_DEV_SYSFS; } int eeh_unfreeze_pe(struct eeh_pe *pe, bool sw_state) { 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; } /* Clear software isolated state */ if (sw_state && (pe->state & EEH_PE_ISOLATED)) eeh_pe_state_clear(pe, EEH_PE_ISOLATED); 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_unfreeze_pe(edev->pe, true); 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 */ atomic_dec(&edev->pe->pass_dev_cnt); WARN_ON(atomic_read(&edev->pe->pass_dev_cnt) < 0); 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; struct iommu_table *tbl; if (!dev) return 0; tbl = get_iommu_table_base(dev); if (tbl && tbl->it_group) { *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 functinality * isn't expected to be disabled on one specific PE. */ switch (option) { case EEH_OPT_ENABLE: if (eeh_enabled()) { ret = eeh_unfreeze_pe(pe, true); break; } ret = -EIO; break; case EEH_OPT_DISABLE: break; case EEH_OPT_THAW_MMIO: case EEH_OPT_THAW_DMA: 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; 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) { struct eeh_dev *edev, *tmp; struct pci_dev *pdev; int ret = 0; /* Restore config space */ 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 */ return eeh_unfreeze_pe(pe, true); } /** * eeh_pe_reset - Issue PE reset according to specified type * @pe: EEH PE * @option: reset type * * 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) { 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); if (ret) break; ret = eeh_pe_reenable_devices(pe); 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); 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); 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; } static int proc_eeh_open(struct inode *inode, struct file *file) { return single_open(file, proc_eeh_show, NULL); } static const struct file_operations proc_eeh_operations = { .open = proc_eeh_open, .read = seq_read, .llseek = seq_lseek, .release = single_release, }; #ifdef CONFIG_DEBUG_FS 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); /* Notify the backend */ if (eeh_ops->post_init) eeh_ops->post_init(); return 0; } static int eeh_enable_dbgfs_get(void *data, u64 *val) { if (eeh_enabled()) *val = 0x1ul; else *val = 0x0ul; return 0; } DEFINE_SIMPLE_ATTRIBUTE(eeh_enable_dbgfs_ops, eeh_enable_dbgfs_get, eeh_enable_dbgfs_set, "0x%llx\n"); #endif static int __init eeh_init_proc(void) { if (machine_is(pseries) || machine_is(powernv)) { proc_create("powerpc/eeh", 0, NULL, &proc_eeh_operations); #ifdef CONFIG_DEBUG_FS debugfs_create_file("eeh_enable", 0600, powerpc_debugfs_root, NULL, &eeh_enable_dbgfs_ops); #endif } return 0; } __initcall(eeh_init_proc);