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Diffstat (limited to 'arch/powerpc/kernel/eeh.c')
| -rw-r--r-- | arch/powerpc/kernel/eeh.c | 1070 |
1 files changed, 1070 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c new file mode 100644 index 00000000000..39954fe941b --- /dev/null +++ b/arch/powerpc/kernel/eeh.c @@ -0,0 +1,1070 @@ +/* + * 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 <linas@austin.ibm.com> + */ + +#include <linux/delay.h> +#include <linux/sched.h> +#include <linux/init.h> +#include <linux/list.h> +#include <linux/pci.h> +#include <linux/proc_fs.h> +#include <linux/rbtree.h> +#include <linux/seq_file.h> +#include <linux/spinlock.h> +#include <linux/export.h> +#include <linux/of.h> + +#include <linux/atomic.h> +#include <asm/eeh.h> +#include <asm/eeh_event.h> +#include <asm/io.h> +#include <asm/machdep.h> +#include <asm/ppc-pci.h> +#include <asm/rtas.h> + + +/** 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) + +/* Platform dependent EEH operations */ +struct eeh_ops *eeh_ops = NULL; + +int eeh_subsystem_enabled; +EXPORT_SYMBOL(eeh_subsystem_enabled); + +/* + * EEH probe mode support. The intention 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_probe_mode; + +/* Lock to avoid races due to multiple reports of an error */ +DEFINE_RAW_SPINLOCK(confirm_error_lock); + +/* 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) + +/** + * 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); + struct pci_dev *dev = eeh_dev_to_pci_dev(edev); + u32 cfg; + int cap, i; + int n = 0; + + n += scnprintf(buf+n, len-n, "%s\n", dn->full_name); + printk(KERN_WARNING "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); + printk(KERN_WARNING "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); + 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) { + eeh_ops->read_config(dn, 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); + + eeh_ops->read_config(dn, 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) { + eeh_ops->read_config(dn, cap, 4, &cfg); + n += scnprintf(buf+n, len-n, "pcix-cmd:%x\n", cfg); + printk(KERN_WARNING "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); + 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++) { + eeh_ops->read_config(dn, 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++) { + eeh_ops->read_config(dn, 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); + } + } + } + + 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; + bool valid_cfg_log = true; + + /* + * 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. + */ + if (eeh_probe_mode_dev() && + (pe->type & EEH_PE_PHB) && + (pe->state & (EEH_PE_ISOLATED | EEH_PE_PHB_DEAD))) + valid_cfg_log = false; + + if (valid_cfg_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) { + 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_probe_mode_dev()) + return -EPERM; + + /* Find the PHB PE */ + phb_pe = eeh_phb_pe_get(pe->phb); + if (!phb_pe) { + pr_warning("%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 | EEH_PE_PHB_DEAD)) { + 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); + eeh_send_failure_event(phb_pe); + + pr_err("EEH: PHB#%x failure detected\n", + phb_pe->phb->global_number); + dump_stack(); + + 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; + unsigned long flags; + struct device_node *dn; + struct pci_dev *dev; + struct eeh_pe *pe; + int rc = 0; + const char *location; + + eeh_stats.total_mmio_ffs++; + + if (!eeh_subsystem_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 = edev->pe; + + /* 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 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 & (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) == + (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) { + eeh_stats.false_positives++; + pe->false_positives++; + rc = 0; + goto dn_unlock; + } + + 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); + + eeh_send_failure_event(pe); + + /* 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_err("EEH: Frozen PE#%x detected on PHB#%x\n", + pe->addr, pe->phb->global_number); + dump_stack(); + + 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 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 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 val; + } + + eeh_dev_check_failure(edev); + + pci_dev_put(eeh_dev_to_pci_dev(edev)); + return val; +} + +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 rc; + + rc = eeh_ops->set_option(pe, function); + if (rc) + pr_warning("%s: Unexpected state change %d on PHB#%d-PE#%x, err=%d\n", + __func__, function, pe->phb->global_number, pe->addr, rc); + + rc = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); + if (rc > 0 && (rc & EEH_STATE_MMIO_ENABLED) && + (function == EEH_OPT_THAW_MMIO)) + return 0; + + 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 = edev->pe; + + 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); + break; + case pcie_hot_reset: + eeh_ops->reset(pe, EEH_RESET_HOT); + break; + case pcie_warm_reset: + eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL); + break; + default: + 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); + + /* 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_pe_state_clear(pe, EEH_PE_ISOLATED); + + eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); + + /* 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 + * @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); + + 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]); +} + +/** + * 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_warning("%s: Invalid EEH ops name for %p\n", + __func__, ops); + return -EINVAL; + } + + if (eeh_ops && eeh_ops != ops) { + pr_warning("%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_warning("%s: Invalid EEH ops name\n", + __func__); + return -EINVAL; + } + + if (eeh_ops && !strcmp(eeh_ops->name, name)) { + eeh_ops = NULL; + return 0; + } + + return -EEXIST; +} + +/** + * 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; + + /* call platform initialization function */ + if (!eeh_ops) { + pr_warning("%s: Platform EEH operation not found\n", + __func__); + return -EEXIST; + } else if ((ret = eeh_ops->init())) { + pr_warning("%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_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_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_warning("%s: Invalid probe mode %d\n", + __func__, eeh_probe_mode); + 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_subsystem_enabled) + pr_info("EEH: PCI Enhanced I/O Error Handling Enabled\n"); + else + pr_warning("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. + */ +static 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_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). + */ +static void eeh_add_device_late(struct pci_dev *dev) +{ + struct device_node *dn; + struct eeh_dev *edev; + + if (!dev || !eeh_subsystem_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; + } + WARN_ON(edev->pdev); + + pci_dev_get(dev); + 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_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 + * @purge_pe: remove the PE or not + * + * 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, int purge_pe) +{ + struct eeh_dev *edev; + + if (!dev || !eeh_subsystem_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) { + pr_debug("EEH: Not referenced !\n"); + return; + } + edev->pdev = NULL; + dev->dev.archdata.edev = NULL; + pci_dev_put(dev); + + eeh_rmv_from_parent_pe(edev, purge_pe); + eeh_addr_cache_rmv_dev(dev); + eeh_sysfs_remove_device(dev); +} + +/** + * eeh_remove_bus_device - Undo EEH setup for the indicated PCI device + * @dev: PCI device + * @purge_pe: remove the corresponding PE or not + * + * 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, int purge_pe) +{ + struct pci_bus *bus = dev->subordinate; + struct pci_dev *child, *tmp; + + eeh_remove_device(dev, purge_pe); + + 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, purge_pe); + } +} +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=%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, +}; + +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); |