/* * 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 /** 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 (60*1000) /* RTAS tokens */ static int ibm_set_eeh_option; static int ibm_set_slot_reset; static int ibm_read_slot_reset_state; static int ibm_read_slot_reset_state2; static int ibm_slot_error_detail; static int ibm_get_config_addr_info; static int ibm_get_config_addr_info2; static int ibm_configure_bridge; static int ibm_configure_pe; int eeh_subsystem_enabled; EXPORT_SYMBOL(eeh_subsystem_enabled); /* Lock to avoid races due to multiple reports of an error */ static DEFINE_RAW_SPINLOCK(confirm_error_lock); /* Buffer for reporting slot-error-detail rtas calls. Its here * in BSS, and not dynamically alloced, so that it ends up in * RMO where RTAS can access it. */ static unsigned char slot_errbuf[RTAS_ERROR_LOG_MAX]; static DEFINE_SPINLOCK(slot_errbuf_lock); static int eeh_error_buf_size; /* 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]; /* System monitoring statistics */ static unsigned long no_device; static unsigned long no_dn; static unsigned long no_cfg_addr; static unsigned long ignored_check; static unsigned long total_mmio_ffs; static unsigned long false_positives; static unsigned long slot_resets; #define IS_BRIDGE(class_code) (((class_code)<<16) == PCI_BASE_CLASS_BRIDGE) /** * eeh_rtas_slot_error_detail - Retrieve error log through RTAS call * @pdn: device node * @severity: temporary or permanent error log * @driver_log: driver log to be combined with the retrieved error log * @loglen: length of driver log * * This routine should be called to retrieve error log through the dedicated * RTAS call. */ static void eeh_rtas_slot_error_detail(struct pci_dn *pdn, int severity, char *driver_log, size_t loglen) { int config_addr; unsigned long flags; int rc; /* Log the error with the rtas logger */ spin_lock_irqsave(&slot_errbuf_lock, flags); memset(slot_errbuf, 0, eeh_error_buf_size); /* Use PE configuration address, if present */ config_addr = pdn->eeh_config_addr; if (pdn->eeh_pe_config_addr) config_addr = pdn->eeh_pe_config_addr; rc = rtas_call(ibm_slot_error_detail, 8, 1, NULL, config_addr, BUID_HI(pdn->phb->buid), BUID_LO(pdn->phb->buid), virt_to_phys(driver_log), loglen, virt_to_phys(slot_errbuf), eeh_error_buf_size, severity); if (rc == 0) log_error(slot_errbuf, ERR_TYPE_RTAS_LOG, 0); spin_unlock_irqrestore(&slot_errbuf_lock, flags); } /** * eeh_gather_pci_data - Copy assorted PCI config space registers to buff * @pdn: 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 pci_dn *pdn, char * buf, size_t len) { struct pci_dev *dev = pdn->pcidev; u32 cfg; int cap, i; int n = 0; n += scnprintf(buf+n, len-n, "%s\n", pdn->node->full_name); printk(KERN_WARNING "EEH: of node=%s\n", pdn->node->full_name); rtas_read_config(pdn, PCI_VENDOR_ID, 4, &cfg); n += scnprintf(buf+n, len-n, "dev/vend:%08x\n", cfg); printk(KERN_WARNING "EEH: PCI device/vendor: %08x\n", cfg); rtas_read_config(pdn, PCI_COMMAND, 4, &cfg); n += scnprintf(buf+n, len-n, "cmd/stat:%x\n", cfg); printk(KERN_WARNING "EEH: PCI cmd/status register: %08x\n", cfg); if (!dev) { printk(KERN_WARNING "EEH: no PCI device for this of node\n"); return n; } /* Gather bridge-specific registers */ if (dev->class >> 16 == PCI_BASE_CLASS_BRIDGE) { rtas_read_config(pdn, PCI_SEC_STATUS, 2, &cfg); n += scnprintf(buf+n, len-n, "sec stat:%x\n", cfg); printk(KERN_WARNING "EEH: Bridge secondary status: %04x\n", cfg); rtas_read_config(pdn, PCI_BRIDGE_CONTROL, 2, &cfg); n += scnprintf(buf+n, len-n, "brdg ctl:%x\n", cfg); printk(KERN_WARNING "EEH: Bridge control: %04x\n", cfg); } /* Dump out the PCI-X command and status regs */ cap = pci_find_capability(dev, PCI_CAP_ID_PCIX); if (cap) { rtas_read_config(pdn, cap, 4, &cfg); n += scnprintf(buf+n, len-n, "pcix-cmd:%x\n", cfg); printk(KERN_WARNING "EEH: PCI-X cmd: %08x\n", cfg); rtas_read_config(pdn, cap+4, 4, &cfg); n += scnprintf(buf+n, len-n, "pcix-stat:%x\n", cfg); printk(KERN_WARNING "EEH: PCI-X status: %08x\n", cfg); } /* If PCI-E capable, dump PCI-E cap 10, and the AER */ cap = pci_find_capability(dev, PCI_CAP_ID_EXP); if (cap) { n += scnprintf(buf+n, len-n, "pci-e cap10:\n"); printk(KERN_WARNING "EEH: PCI-E capabilities and status follow:\n"); for (i=0; i<=8; i++) { rtas_read_config(pdn, cap+4*i, 4, &cfg); n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg); printk(KERN_WARNING "EEH: PCI-E %02x: %08x\n", i, cfg); } cap = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR); if (cap) { n += scnprintf(buf+n, len-n, "pci-e AER:\n"); printk(KERN_WARNING "EEH: PCI-E AER capability register set follows:\n"); for (i=0; i<14; i++) { rtas_read_config(pdn, cap+4*i, 4, &cfg); n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg); printk(KERN_WARNING "EEH: PCI-E AER %02x: %08x\n", i, cfg); } } } /* Gather status on devices under the bridge */ if (dev->class >> 16 == PCI_BASE_CLASS_BRIDGE) { struct device_node *dn; for_each_child_of_node(pdn->node, dn) { pdn = PCI_DN(dn); if (pdn) n += eeh_gather_pci_data(pdn, buf+n, len-n); } } return n; } /** * eeh_slot_error_detail - Generate combined log including driver log and error log * @pdn: device node * @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 pci_dn *pdn, int severity) { size_t loglen = 0; pci_regs_buf[0] = 0; eeh_pci_enable(pdn, EEH_THAW_MMIO); eeh_configure_bridge(pdn); eeh_restore_bars(pdn); loglen = eeh_gather_pci_data(pdn, pci_regs_buf, EEH_PCI_REGS_LOG_LEN); eeh_rtas_slot_error_detail(pdn, severity, pci_regs_buf, loglen); } /** * eeh_read_slot_reset_state - Read the reset state of a device node's slot * @dn: device node to read * @rets: array to return results in * * Read the reset state of a device node's slot through platform dependent * function call. */ static int eeh_read_slot_reset_state(struct pci_dn *pdn, int rets[]) { int token, outputs; int config_addr; if (ibm_read_slot_reset_state2 != RTAS_UNKNOWN_SERVICE) { token = ibm_read_slot_reset_state2; outputs = 4; } else { token = ibm_read_slot_reset_state; rets[2] = 0; /* fake PE Unavailable info */ outputs = 3; } /* Use PE configuration address, if present */ config_addr = pdn->eeh_config_addr; if (pdn->eeh_pe_config_addr) config_addr = pdn->eeh_pe_config_addr; return rtas_call(token, 3, outputs, rets, config_addr, BUID_HI(pdn->phb->buid), BUID_LO(pdn->phb->buid)); } /** * eeh_wait_for_slot_status - Returns error status of slot * @pdn: pci device node * @max_wait_msecs: maximum number to millisecs to wait * * Return negative value if a permanent error, else return * Partition Endpoint (PE) status value. * * If @max_wait_msecs is positive, then this routine will * sleep until a valid status can be obtained, or until * the max allowed wait time is exceeded, in which case * a -2 is returned. */ int eeh_wait_for_slot_status(struct pci_dn *pdn, int max_wait_msecs) { int rc; int rets[3]; int mwait; while (1) { rc = eeh_read_slot_reset_state(pdn, rets); if (rc) return rc; if (rets[1] == 0) return -1; /* EEH is not supported */ if (rets[0] != 5) return rets[0]; /* return actual status */ if (rets[2] == 0) return -1; /* permanently unavailable */ if (max_wait_msecs <= 0) break; mwait = rets[2]; if (mwait <= 0) { printk(KERN_WARNING "EEH: Firmware returned bad wait value=%d\n", mwait); mwait = 1000; } else if (mwait > 300*1000) { printk(KERN_WARNING "EEH: Firmware is taking too long, time=%d\n", mwait); mwait = 300*1000; } max_wait_msecs -= mwait; msleep(mwait); } printk(KERN_WARNING "EEH: Timed out waiting for slot status\n"); return -2; } /** * 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; ptep = find_linux_pte(init_mm.pgd, token); if (!ptep) return token; pa = pte_pfn(*ptep) << PAGE_SHIFT; return pa | (token & (PAGE_SIZE-1)); } /** * eeh_find_device_pe - Retrieve the PE for the given device * @dn: device node * * Return the PE under which this device lies */ struct device_node *eeh_find_device_pe(struct device_node *dn) { while ((dn->parent) && PCI_DN(dn->parent) && (PCI_DN(dn->parent)->eeh_mode & EEH_MODE_SUPPORTED)) { dn = dn->parent; } return dn; } /** * __eeh_mark_slot - Mark all child devices as failed * @parent: parent device * @mode_flag: failure flag * * Mark all devices that are children of this device as failed. * Mark the device driver too, so that it can see the failure * immediately; this is critical, since some drivers poll * status registers in interrupts ... If a driver is polling, * and the slot is frozen, then the driver can deadlock in * an interrupt context, which is bad. */ static void __eeh_mark_slot(struct device_node *parent, int mode_flag) { struct device_node *dn; for_each_child_of_node(parent, dn) { if (PCI_DN(dn)) { /* Mark the pci device driver too */ struct pci_dev *dev = PCI_DN(dn)->pcidev; PCI_DN(dn)->eeh_mode |= mode_flag; if (dev && dev->driver) dev->error_state = pci_channel_io_frozen; __eeh_mark_slot(dn, mode_flag); } } } /** * eeh_mark_slot - Mark the indicated device and its children as failed * @dn: parent device * @mode_flag: failure flag * * Mark the indicated device and its child devices as failed. * The device drivers are marked as failed as well. */ void eeh_mark_slot(struct device_node *dn, int mode_flag) { struct pci_dev *dev; dn = eeh_find_device_pe(dn); /* Back up one, since config addrs might be shared */ if (!pcibios_find_pci_bus(dn) && PCI_DN(dn->parent)) dn = dn->parent; PCI_DN(dn)->eeh_mode |= mode_flag; /* Mark the pci device too */ dev = PCI_DN(dn)->pcidev; if (dev) dev->error_state = pci_channel_io_frozen; __eeh_mark_slot(dn, mode_flag); } /** * __eeh_clear_slot - Clear failure flag for the child devices * @parent: parent device * @mode_flag: flag to be cleared * * Clear failure flag for the child devices. */ static void __eeh_clear_slot(struct device_node *parent, int mode_flag) { struct device_node *dn; for_each_child_of_node(parent, dn) { if (PCI_DN(dn)) { PCI_DN(dn)->eeh_mode &= ~mode_flag; PCI_DN(dn)->eeh_check_count = 0; __eeh_clear_slot(dn, mode_flag); } } } /** * eeh_clear_slot - Clear failure flag for the indicated device and its children * @dn: parent device * @mode_flag: flag to be cleared * * Clear failure flag for the indicated device and its children. */ void eeh_clear_slot(struct device_node *dn, int mode_flag) { unsigned long flags; raw_spin_lock_irqsave(&confirm_error_lock, flags); dn = eeh_find_device_pe(dn); /* Back up one, since config addrs might be shared */ if (!pcibios_find_pci_bus(dn) && PCI_DN(dn->parent)) dn = dn->parent; PCI_DN(dn)->eeh_mode &= ~mode_flag; PCI_DN(dn)->eeh_check_count = 0; __eeh_clear_slot(dn, mode_flag); raw_spin_unlock_irqrestore(&confirm_error_lock, flags); } /** * eeh_dn_check_failure - Check if all 1's data is due to EEH slot freeze * @dn: device node * @dev: pci device, if known * * 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_dn_check_failure(struct device_node *dn, struct pci_dev *dev) { int ret; int rets[3]; unsigned long flags; struct pci_dn *pdn; int rc = 0; const char *location; total_mmio_ffs++; if (!eeh_subsystem_enabled) return 0; if (!dn) { no_dn++; return 0; } dn = eeh_find_device_pe(dn); pdn = PCI_DN(dn); /* Access to IO BARs might get this far and still not want checking. */ if (!(pdn->eeh_mode & EEH_MODE_SUPPORTED) || pdn->eeh_mode & EEH_MODE_NOCHECK) { ignored_check++; pr_debug("EEH: Ignored check (%x) for %s %s\n", pdn->eeh_mode, eeh_pci_name(dev), dn->full_name); return 0; } if (!pdn->eeh_config_addr && !pdn->eeh_pe_config_addr) { no_cfg_addr++; 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. */ raw_spin_lock_irqsave(&confirm_error_lock, flags); rc = 1; if (pdn->eeh_mode & EEH_MODE_ISOLATED) { pdn->eeh_check_count ++; if (pdn->eeh_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", pdn->eeh_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_read_slot_reset_state(pdn, rets); /* If the call to firmware failed, punt */ if (ret != 0) { printk(KERN_WARNING "EEH: eeh_read_slot_reset_state() failed; rc=%d dn=%s\n", ret, dn->full_name); false_positives++; pdn->eeh_false_positives ++; rc = 0; goto dn_unlock; } /* Note that config-io to empty slots may fail; * they are empty when they don't have children. */ if ((rets[0] == 5) && (rets[2] == 0) && (dn->child == NULL)) { false_positives++; pdn->eeh_false_positives ++; rc = 0; goto dn_unlock; } /* If EEH is not supported on this device, punt. */ if (rets[1] != 1) { printk(KERN_WARNING "EEH: event on unsupported device, rc=%d dn=%s\n", ret, dn->full_name); false_positives++; pdn->eeh_false_positives ++; rc = 0; goto dn_unlock; } /* If not the kind of error we know about, punt. */ if (rets[0] != 1 && rets[0] != 2 && rets[0] != 4 && rets[0] != 5) { false_positives++; pdn->eeh_false_positives ++; rc = 0; goto dn_unlock; } slot_resets++; /* Avoid repeated reports of this failure, including problems * with other functions on this device, and functions under * bridges. */ eeh_mark_slot(dn, EEH_MODE_ISOLATED); raw_spin_unlock_irqrestore(&confirm_error_lock, flags); eeh_send_failure_event(dn, dev); /* 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. */ dump_stack(); return 1; dn_unlock: raw_spin_unlock_irqrestore(&confirm_error_lock, flags); return rc; } EXPORT_SYMBOL_GPL(eeh_dn_check_failure); /** * eeh_check_failure - Check if all 1's data is due to EEH slot freeze * @token: I/O token, should be address in the form 0xA.... * @val: value, should be all 1's (XXX why do we need this arg??) * * Check for an EEH failure at the given token 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. */ unsigned long eeh_check_failure(const volatile void __iomem *token, unsigned long val) { unsigned long addr; struct pci_dev *dev; struct device_node *dn; /* Finding the phys addr + pci device; this is pretty quick. */ addr = eeh_token_to_phys((unsigned long __force) token); dev = pci_get_device_by_addr(addr); if (!dev) { no_device++; return val; } dn = pci_device_to_OF_node(dev); eeh_dn_check_failure(dn, dev); pci_dev_put(dev); return val; } EXPORT_SYMBOL(eeh_check_failure); /** * eeh_pci_enable - Enable MMIO or DMA transfers for this slot * @pdn pci device node * * 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 pci_dn *pdn, int function) { int config_addr; int rc; /* Use PE configuration address, if present */ config_addr = pdn->eeh_config_addr; if (pdn->eeh_pe_config_addr) config_addr = pdn->eeh_pe_config_addr; rc = rtas_call(ibm_set_eeh_option, 4, 1, NULL, config_addr, BUID_HI(pdn->phb->buid), BUID_LO(pdn->phb->buid), function); if (rc) printk(KERN_WARNING "EEH: Unexpected state change %d, err=%d dn=%s\n", function, rc, pdn->node->full_name); rc = eeh_wait_for_slot_status(pdn, PCI_BUS_RESET_WAIT_MSEC); if ((rc == 4) && (function == EEH_THAW_MMIO)) return 0; return rc; } /** * eeh_slot_reset - Raises/Lowers the pci #RST line * @pdn: pci device node * @state: 1/0 to raise/lower the #RST * * Clear the EEH-frozen condition on a slot. This routine * asserts the PCI #RST line if the 'state' argument is '1', * and drops the #RST line if 'state is '0'. This routine is * safe to call in an interrupt context. */ static void eeh_slot_reset(struct pci_dn *pdn, int state) { int config_addr; int rc; BUG_ON(pdn==NULL); if (!pdn->phb) { printk(KERN_WARNING "EEH: in slot reset, device node %s has no phb\n", pdn->node->full_name); return; } /* Use PE configuration address, if present */ config_addr = pdn->eeh_config_addr; if (pdn->eeh_pe_config_addr) config_addr = pdn->eeh_pe_config_addr; rc = rtas_call(ibm_set_slot_reset, 4, 1, NULL, config_addr, BUID_HI(pdn->phb->buid), BUID_LO(pdn->phb->buid), state); /* Fundamental-reset not supported on this PE, try hot-reset */ if (rc == -8 && state == 3) { rc = rtas_call(ibm_set_slot_reset, 4, 1, NULL, config_addr, BUID_HI(pdn->phb->buid), BUID_LO(pdn->phb->buid), 1); if (rc) printk(KERN_WARNING "EEH: Unable to reset the failed slot," " #RST=%d dn=%s\n", rc, pdn->node->full_name); } } /** * 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 device_node *dn = pci_device_to_OF_node(dev); struct pci_dn *pdn = PCI_DN(dn); switch (state) { case pcie_deassert_reset: eeh_slot_reset(pdn, 0); break; case pcie_hot_reset: eeh_slot_reset(pdn, 1); break; case pcie_warm_reset: eeh_slot_reset(pdn, 3); break; default: return -EINVAL; }; return 0; } /** * __eeh_set_pe_freset - Check the required reset for child devices * @parent: parent device * @freset: return value * * Each device might have its preferred reset type: fundamental or * hot reset. The routine is used to collect the information from * the child devices so that they could be reset accordingly. */ void __eeh_set_pe_freset(struct device_node *parent, unsigned int *freset) { struct device_node *dn; for_each_child_of_node(parent, dn) { if (PCI_DN(dn)) { struct pci_dev *dev = PCI_DN(dn)->pcidev; if (dev && dev->driver) *freset |= dev->needs_freset; __eeh_set_pe_freset(dn, freset); } } } /** * eeh_set_pe_freset - Check the required reset for the indicated device and its children * @dn: parent device * @freset: 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. */ void eeh_set_pe_freset(struct device_node *dn, unsigned int *freset) { struct pci_dev *dev; dn = eeh_find_device_pe(dn); /* Back up one, since config addrs might be shared */ if (!pcibios_find_pci_bus(dn) && PCI_DN(dn->parent)) dn = dn->parent; dev = PCI_DN(dn)->pcidev; if (dev) *freset |= dev->needs_freset; __eeh_set_pe_freset(dn, freset); } /** * eeh_reset_pe_once - Assert the pci #RST line for 1/4 second * @pdn: pci device node to be reset. * * Assert the PCI #RST line for 1/4 second. */ static void eeh_reset_pe_once(struct pci_dn *pdn) { 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_set_pe_freset(pdn->node, &freset); if (freset) eeh_slot_reset(pdn, 3); else eeh_slot_reset(pdn, 1); /* The PCI bus requires that the reset be held high for at least * a 100 milliseconds. We wait a bit longer 'just in case'. */ #define PCI_BUS_RST_HOLD_TIME_MSEC 250 msleep(PCI_BUS_RST_HOLD_TIME_MSEC); /* We might get hit with another EEH freeze as soon as the * pci slot reset line is dropped. Make sure we don't miss * these, and clear the flag now. */ eeh_clear_slot(pdn->node, EEH_MODE_ISOLATED); eeh_slot_reset(pdn, 0); /* After a PCI slot has been reset, the PCI Express spec requires * a 1.5 second idle time for the bus to stabilize, before starting * up traffic. */ #define PCI_BUS_SETTLE_TIME_MSEC 1800 msleep(PCI_BUS_SETTLE_TIME_MSEC); } /** * eeh_reset_pe - Reset the indicated PE * @pdn: PCI device node * * 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 pci_dn *pdn) { int i, rc; /* Take three shots at resetting the bus */ for (i=0; i<3; i++) { eeh_reset_pe_once(pdn); rc = eeh_wait_for_slot_status(pdn, PCI_BUS_RESET_WAIT_MSEC); if (rc == 0) return 0; if (rc < 0) { printk(KERN_ERR "EEH: unrecoverable slot failure %s\n", pdn->node->full_name); return -1; } printk(KERN_ERR "EEH: bus reset %d failed on slot %s, rc=%d\n", i+1, pdn->node->full_name, rc); } return -1; } /** Save and restore of PCI BARs * * Although firmware will set up BARs during boot, it doesn't * set up device BAR's after a device reset, although it will, * if requested, set up bridge configuration. Thus, we need to * configure the PCI devices ourselves. */ /** * eeh_restore_one_device_bars - Restore the Base Address Registers for one device * @pdn: pci device node * * Loads the PCI configuration space base address registers, * the expansion ROM base address, the latency timer, and etc. * from the saved values in the device node. */ static inline void eeh_restore_one_device_bars(struct pci_dn *pdn) { int i; u32 cmd; if (NULL==pdn->phb) return; for (i=4; i<10; i++) { rtas_write_config(pdn, i*4, 4, pdn->config_space[i]); } /* 12 == Expansion ROM Address */ rtas_write_config(pdn, 12*4, 4, pdn->config_space[12]); #define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF)) #define SAVED_BYTE(OFF) (((u8 *)(pdn->config_space))[BYTE_SWAP(OFF)]) rtas_write_config(pdn, PCI_CACHE_LINE_SIZE, 1, SAVED_BYTE(PCI_CACHE_LINE_SIZE)); rtas_write_config(pdn, PCI_LATENCY_TIMER, 1, SAVED_BYTE(PCI_LATENCY_TIMER)); /* max latency, min grant, interrupt pin and line */ rtas_write_config(pdn, 15*4, 4, pdn->config_space[15]); /* Restore PERR & SERR bits, some devices require it, * don't touch the other command bits */ rtas_read_config(pdn, PCI_COMMAND, 4, &cmd); if (pdn->config_space[1] & PCI_COMMAND_PARITY) cmd |= PCI_COMMAND_PARITY; else cmd &= ~PCI_COMMAND_PARITY; if (pdn->config_space[1] & PCI_COMMAND_SERR) cmd |= PCI_COMMAND_SERR; else cmd &= ~PCI_COMMAND_SERR; rtas_write_config(pdn, PCI_COMMAND, 4, cmd); } /** * eeh_restore_bars - Restore the PCI config space info * @pdn: PCI device node * * This routine performs a recursive walk to the children * of this device as well. */ void eeh_restore_bars(struct pci_dn *pdn) { struct device_node *dn; if (!pdn) return; if ((pdn->eeh_mode & EEH_MODE_SUPPORTED) && !IS_BRIDGE(pdn->class_code)) eeh_restore_one_device_bars(pdn); for_each_child_of_node(pdn->node, dn) eeh_restore_bars(PCI_DN(dn)); } /** * eeh_save_bars - Save device bars * @pdn: PCI device node * * 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. */ static void eeh_save_bars(struct pci_dn *pdn) { int i; if (!pdn ) return; for (i = 0; i < 16; i++) rtas_read_config(pdn, i * 4, 4, &pdn->config_space[i]); } /** * eeh_configure_bridge - Configure PCI bridges for the indicated PE * @pdn: PCI device node * * PCI bridges might be included in PE. In order to make the PE work * again. The included PCI bridges should be recovered after the PE * encounters frozen state. */ void eeh_configure_bridge(struct pci_dn *pdn) { int config_addr; int rc; int token; /* Use PE configuration address, if present */ config_addr = pdn->eeh_config_addr; if (pdn->eeh_pe_config_addr) config_addr = pdn->eeh_pe_config_addr; /* Use new configure-pe function, if supported */ if (ibm_configure_pe != RTAS_UNKNOWN_SERVICE) token = ibm_configure_pe; else token = ibm_configure_bridge; rc = rtas_call(token, 3, 1, NULL, config_addr, BUID_HI(pdn->phb->buid), BUID_LO(pdn->phb->buid)); if (rc) { printk(KERN_WARNING "EEH: Unable to configure device bridge (%d) for %s\n", rc, pdn->node->full_name); } } #define EEH_ENABLE 1 struct eeh_early_enable_info { unsigned int buid_hi; unsigned int buid_lo; }; /** * eeh_get_pe_addr - Retrieve PE address with given BDF address * @config_addr: BDF address * @info: BUID of the associated PHB * * There're 2 kinds of addresses existing in EEH core components: * BDF address and PE address. Besides, there has dedicated platform * dependent function call to retrieve the PE address according to * the given BDF address. Further more, we prefer PE address on BDF * address in EEH core components. */ static int eeh_get_pe_addr(int config_addr, struct eeh_early_enable_info *info) { unsigned int rets[3]; int ret; /* Use latest config-addr token on power6 */ if (ibm_get_config_addr_info2 != RTAS_UNKNOWN_SERVICE) { /* Make sure we have a PE in hand */ ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets, config_addr, info->buid_hi, info->buid_lo, 1); if (ret || (rets[0]==0)) return 0; ret = rtas_call(ibm_get_config_addr_info2, 4, 2, rets, config_addr, info->buid_hi, info->buid_lo, 0); if (ret) return 0; return rets[0]; } /* Use older config-addr token on power5 */ if (ibm_get_config_addr_info != RTAS_UNKNOWN_SERVICE) { ret = rtas_call(ibm_get_config_addr_info, 4, 2, rets, config_addr, info->buid_hi, info->buid_lo, 0); if (ret) return 0; return rets[0]; } return 0; } /** * eeh_early_enable - Early enable EEH on the indicated device * @dn: device node * @data: BUID * * Enable EEH functionality on the specified PCI device. The function * is expected to be called before real PCI probing is done. However, * the PHBs have been initialized at this point. */ static void *eeh_early_enable(struct device_node *dn, void *data) { unsigned int rets[3]; struct eeh_early_enable_info *info = data; int ret; const u32 *class_code = of_get_property(dn, "class-code", NULL); const u32 *vendor_id = of_get_property(dn, "vendor-id", NULL); const u32 *device_id = of_get_property(dn, "device-id", NULL); const u32 *regs; int enable; struct pci_dn *pdn = PCI_DN(dn); pdn->class_code = 0; pdn->eeh_mode = 0; pdn->eeh_check_count = 0; pdn->eeh_freeze_count = 0; pdn->eeh_false_positives = 0; if (!of_device_is_available(dn)) return NULL; /* Ignore bad nodes. */ if (!class_code || !vendor_id || !device_id) return NULL; /* There is nothing to check on PCI to ISA bridges */ if (dn->type && !strcmp(dn->type, "isa")) { pdn->eeh_mode |= EEH_MODE_NOCHECK; return NULL; } pdn->class_code = *class_code; /* Ok... see if this device supports EEH. Some do, some don't, * and the only way to find out is to check each and every one. */ regs = of_get_property(dn, "reg", NULL); if (regs) { /* First register entry is addr (00BBSS00) */ /* Try to enable eeh */ ret = rtas_call(ibm_set_eeh_option, 4, 1, NULL, regs[0], info->buid_hi, info->buid_lo, EEH_ENABLE); enable = 0; if (ret == 0) { pdn->eeh_config_addr = regs[0]; /* If the newer, better, ibm,get-config-addr-info is supported, * then use that instead. */ pdn->eeh_pe_config_addr = eeh_get_pe_addr(pdn->eeh_config_addr, info); /* Some older systems (Power4) allow the * ibm,set-eeh-option call to succeed even on nodes * where EEH is not supported. Verify support * explicitly. */ ret = eeh_read_slot_reset_state(pdn, rets); if ((ret == 0) && (rets[1] == 1)) enable = 1; } if (enable) { eeh_subsystem_enabled = 1; pdn->eeh_mode |= EEH_MODE_SUPPORTED; pr_debug("EEH: %s: eeh enabled, config=%x pe_config=%x\n", dn->full_name, pdn->eeh_config_addr, pdn->eeh_pe_config_addr); } else { /* This device doesn't support EEH, but it may have an * EEH parent, in which case we mark it as supported. */ if (dn->parent && PCI_DN(dn->parent) && (PCI_DN(dn->parent)->eeh_mode & EEH_MODE_SUPPORTED)) { /* Parent supports EEH. */ pdn->eeh_mode |= EEH_MODE_SUPPORTED; pdn->eeh_config_addr = PCI_DN(dn->parent)->eeh_config_addr; return NULL; } } } else { printk(KERN_WARNING "EEH: %s: unable to get reg property.\n", dn->full_name); } eeh_save_bars(pdn); return NULL; } /** * 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. */ void __init eeh_init(void) { struct device_node *phb, *np; struct eeh_early_enable_info info; raw_spin_lock_init(&confirm_error_lock); spin_lock_init(&slot_errbuf_lock); np = of_find_node_by_path("/rtas"); if (np == NULL) return; ibm_set_eeh_option = rtas_token("ibm,set-eeh-option"); ibm_set_slot_reset = rtas_token("ibm,set-slot-reset"); ibm_read_slot_reset_state2 = rtas_token("ibm,read-slot-reset-state2"); ibm_read_slot_reset_state = rtas_token("ibm,read-slot-reset-state"); ibm_slot_error_detail = rtas_token("ibm,slot-error-detail"); ibm_get_config_addr_info = rtas_token("ibm,get-config-addr-info"); ibm_get_config_addr_info2 = rtas_token("ibm,get-config-addr-info2"); ibm_configure_bridge = rtas_token("ibm,configure-bridge"); ibm_configure_pe = rtas_token("ibm,configure-pe"); if (ibm_set_eeh_option == RTAS_UNKNOWN_SERVICE) return; eeh_error_buf_size = rtas_token("rtas-error-log-max"); if (eeh_error_buf_size == RTAS_UNKNOWN_SERVICE) { eeh_error_buf_size = 1024; } if (eeh_error_buf_size > RTAS_ERROR_LOG_MAX) { printk(KERN_WARNING "EEH: rtas-error-log-max is bigger than allocated " "buffer ! (%d vs %d)", eeh_error_buf_size, RTAS_ERROR_LOG_MAX); eeh_error_buf_size = RTAS_ERROR_LOG_MAX; } /* Enable EEH for all adapters. Note that eeh requires buid's */ for (phb = of_find_node_by_name(NULL, "pci"); phb; phb = of_find_node_by_name(phb, "pci")) { unsigned long buid; buid = get_phb_buid(phb); if (buid == 0 || PCI_DN(phb) == NULL) continue; info.buid_lo = BUID_LO(buid); info.buid_hi = BUID_HI(buid); traverse_pci_devices(phb, eeh_early_enable, &info); } if (eeh_subsystem_enabled) printk(KERN_INFO "EEH: PCI Enhanced I/O Error Handling Enabled\n"); else printk(KERN_WARNING "EEH: No capable adapters found\n"); } /** * 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. */ static void eeh_add_device_early(struct device_node *dn) { struct pci_controller *phb; struct eeh_early_enable_info info; if (!dn || !PCI_DN(dn)) return; phb = PCI_DN(dn)->phb; /* USB Bus children of PCI devices will not have BUID's */ if (NULL == phb || 0 == phb->buid) return; info.buid_hi = BUID_HI(phb->buid); info.buid_lo = BUID_LO(phb->buid); eeh_early_enable(dn, &info); } /** * 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). */ static void eeh_add_device_late(struct pci_dev *dev) { struct device_node *dn; struct pci_dn *pdn; if (!dev || !eeh_subsystem_enabled) return; pr_debug("EEH: Adding device %s\n", pci_name(dev)); dn = pci_device_to_OF_node(dev); pdn = PCI_DN(dn); if (pdn->pcidev == dev) { pr_debug("EEH: Already referenced !\n"); return; } WARN_ON(pdn->pcidev); pci_dev_get(dev); pdn->pcidev = dev; pci_addr_cache_insert_device(dev); eeh_sysfs_add_device(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_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. */ static void eeh_remove_device(struct pci_dev *dev) { struct device_node *dn; if (!dev || !eeh_subsystem_enabled) return; /* Unregister the device with the EEH/PCI address search system */ pr_debug("EEH: Removing device %s\n", pci_name(dev)); dn = pci_device_to_OF_node(dev); if (PCI_DN(dn)->pcidev == NULL) { pr_debug("EEH: Not referenced !\n"); return; } PCI_DN(dn)->pcidev = NULL; pci_dev_put(dev); pci_addr_cache_remove_device(dev); eeh_sysfs_remove_device(dev); } /** * eeh_remove_bus_device - Undo EEH setup for the indicated PCI device * @dev: PCI device * * This routine must be called when a device is removed from the * running system through hotplug or dlpar. The corresponding * PCI address cache will be removed. */ void eeh_remove_bus_device(struct pci_dev *dev) { struct pci_bus *bus = dev->subordinate; struct pci_dev *child, *tmp; eeh_remove_device(dev); if (bus && dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { list_for_each_entry_safe(child, tmp, &bus->devices, bus_list) eeh_remove_bus_device(child); } } EXPORT_SYMBOL_GPL(eeh_remove_bus_device); static int proc_eeh_show(struct seq_file *m, void *v) { if (0 == eeh_subsystem_enabled) { seq_printf(m, "EEH Subsystem is globally disabled\n"); seq_printf(m, "eeh_total_mmio_ffs=%ld\n", total_mmio_ffs); } else { seq_printf(m, "EEH Subsystem is enabled\n"); seq_printf(m, "no device=%ld\n" "no device node=%ld\n" "no config address=%ld\n" "check not wanted=%ld\n" "eeh_total_mmio_ffs=%ld\n" "eeh_false_positives=%ld\n" "eeh_slot_resets=%ld\n", no_device, no_dn, no_cfg_addr, ignored_check, total_mmio_ffs, false_positives, 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, }; static int __init eeh_init_proc(void) { if (machine_is(pseries)) proc_create("powerpc/eeh", 0, NULL, &proc_eeh_operations); return 0; } __initcall(eeh_init_proc);