diff options
Diffstat (limited to 'arch/powerpc/platforms/pseries/eeh.c')
| -rw-r--r-- | arch/powerpc/platforms/pseries/eeh.c | 1217 |
1 files changed, 1217 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/eeh.c b/arch/powerpc/platforms/pseries/eeh.c new file mode 100644 index 00000000..a75e37dc --- /dev/null +++ b/arch/powerpc/platforms/pseries/eeh.c @@ -0,0 +1,1217 @@ +/* + * 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); + +/* Lock to avoid races due to multiple reports of an error */ +static 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); + } + } + } + + /* Gather status on devices under the bridge */ + if (dev->class >> 16 == PCI_BASE_CLASS_BRIDGE) { + struct device_node *child; + + for_each_child_of_node(dn, child) { + if (of_node_to_eeh_dev(child)) + n += eeh_gather_pci_data(of_node_to_eeh_dev(child), buf+n, len-n); + } + } + + return n; +} + +/** + * eeh_slot_error_detail - Generate combined log including driver log and error log + * @edev: device to report error log for + * @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_dev *edev, int severity) +{ + size_t loglen = 0; + pci_regs_buf[0] = 0; + + eeh_pci_enable(edev, EEH_OPT_THAW_MMIO); + eeh_ops->configure_bridge(eeh_dev_to_of_node(edev)); + eeh_restore_bars(edev); + loglen = eeh_gather_pci_data(edev, pci_regs_buf, EEH_PCI_REGS_LOG_LEN); + + eeh_ops->get_log(eeh_dev_to_of_node(edev), 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; + + 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 && of_node_to_eeh_dev(dn->parent) && + (of_node_to_eeh_dev(dn->parent)->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 (of_node_to_eeh_dev(dn)) { + /* Mark the pci device driver too */ + struct pci_dev *dev = of_node_to_eeh_dev(dn)->pdev; + + of_node_to_eeh_dev(dn)->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) && of_node_to_eeh_dev(dn->parent)) + dn = dn->parent; + + of_node_to_eeh_dev(dn)->mode |= mode_flag; + + /* Mark the pci device too */ + dev = of_node_to_eeh_dev(dn)->pdev; + 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 (of_node_to_eeh_dev(dn)) { + of_node_to_eeh_dev(dn)->mode &= ~mode_flag; + of_node_to_eeh_dev(dn)->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) && of_node_to_eeh_dev(dn->parent)) + dn = dn->parent; + + of_node_to_eeh_dev(dn)->mode &= ~mode_flag; + of_node_to_eeh_dev(dn)->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; + unsigned long flags; + struct eeh_dev *edev; + int rc = 0; + const char *location; + + eeh_stats.total_mmio_ffs++; + + if (!eeh_subsystem_enabled) + return 0; + + if (!dn) { + eeh_stats.no_dn++; + return 0; + } + dn = eeh_find_device_pe(dn); + edev = of_node_to_eeh_dev(dn); + + /* Access to IO BARs might get this far and still not want checking. */ + if (!(edev->mode & EEH_MODE_SUPPORTED) || + edev->mode & EEH_MODE_NOCHECK) { + eeh_stats.ignored_check++; + pr_debug("EEH: Ignored check (%x) for %s %s\n", + edev->mode, eeh_pci_name(dev), dn->full_name); + return 0; + } + + if (!edev->config_addr && !edev->pe_config_addr) { + eeh_stats.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 (edev->mode & EEH_MODE_ISOLATED) { + edev->check_count++; + if (edev->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", + edev->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(dn, 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++; + edev->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_mark_slot(dn, EEH_MODE_ISOLATED); + raw_spin_unlock_irqrestore(&confirm_error_lock, flags); + + eeh_send_failure_event(edev); + + /* 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_addr_cache_get_device(addr); + if (!dev) { + eeh_stats.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 + * @edev: 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 eeh_dev *edev, int function) +{ + int rc; + struct device_node *dn = eeh_dev_to_of_node(edev); + + rc = eeh_ops->set_option(dn, function); + if (rc) + printk(KERN_WARNING "EEH: Unexpected state change %d, err=%d dn=%s\n", + function, rc, dn->full_name); + + rc = eeh_ops->wait_state(dn, 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 device_node *dn = pci_device_to_OF_node(dev); + + switch (state) { + case pcie_deassert_reset: + eeh_ops->reset(dn, EEH_RESET_DEACTIVATE); + break; + case pcie_hot_reset: + eeh_ops->reset(dn, EEH_RESET_HOT); + break; + case pcie_warm_reset: + eeh_ops->reset(dn, EEH_RESET_FUNDAMENTAL); + 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 (of_node_to_eeh_dev(dn)) { + struct pci_dev *dev = of_node_to_eeh_dev(dn)->pdev; + + 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) && of_node_to_eeh_dev(dn->parent)) + dn = dn->parent; + + dev = of_node_to_eeh_dev(dn)->pdev; + 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 + * @edev: pci device node to be reset. + * + * Assert the PCI #RST line for 1/4 second. + */ +static void eeh_reset_pe_once(struct eeh_dev *edev) +{ + unsigned int freset = 0; + struct device_node *dn = eeh_dev_to_of_node(edev); + + /* 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(dn, &freset); + + if (freset) + eeh_ops->reset(dn, EEH_RESET_FUNDAMENTAL); + else + eeh_ops->reset(dn, 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_clear_slot(dn, EEH_MODE_ISOLATED); + + eeh_ops->reset(dn, 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 + * @edev: PCI device associated EEH device + * + * 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_dev *edev) +{ + int i, rc; + struct device_node *dn = eeh_dev_to_of_node(edev); + + /* Take three shots at resetting the bus */ + for (i=0; i<3; i++) { + eeh_reset_pe_once(edev); + + rc = eeh_ops->wait_state(dn, PCI_BUS_RESET_WAIT_MSEC); + if (rc == (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) + return 0; + + if (rc < 0) { + printk(KERN_ERR "EEH: unrecoverable slot failure %s\n", + dn->full_name); + return -1; + } + printk(KERN_ERR "EEH: bus reset %d failed on slot %s, rc=%d\n", + i+1, dn->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 + * @edev: PCI device associated EEH device + * + * 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 eeh_dev *edev) +{ + int i; + u32 cmd; + struct device_node *dn = eeh_dev_to_of_node(edev); + + if (!edev->phb) + return; + + for (i=4; i<10; i++) { + eeh_ops->write_config(dn, i*4, 4, edev->config_space[i]); + } + + /* 12 == Expansion ROM Address */ + eeh_ops->write_config(dn, 12*4, 4, edev->config_space[12]); + +#define BYTE_SWAP(OFF) (8*((OFF)/4)+3-(OFF)) +#define SAVED_BYTE(OFF) (((u8 *)(edev->config_space))[BYTE_SWAP(OFF)]) + + eeh_ops->write_config(dn, PCI_CACHE_LINE_SIZE, 1, + SAVED_BYTE(PCI_CACHE_LINE_SIZE)); + + eeh_ops->write_config(dn, PCI_LATENCY_TIMER, 1, + SAVED_BYTE(PCI_LATENCY_TIMER)); + + /* max latency, min grant, interrupt pin and line */ + eeh_ops->write_config(dn, 15*4, 4, edev->config_space[15]); + + /* Restore PERR & SERR bits, some devices require it, + * don't touch the other command bits + */ + eeh_ops->read_config(dn, PCI_COMMAND, 4, &cmd); + if (edev->config_space[1] & PCI_COMMAND_PARITY) + cmd |= PCI_COMMAND_PARITY; + else + cmd &= ~PCI_COMMAND_PARITY; + if (edev->config_space[1] & PCI_COMMAND_SERR) + cmd |= PCI_COMMAND_SERR; + else + cmd &= ~PCI_COMMAND_SERR; + eeh_ops->write_config(dn, PCI_COMMAND, 4, cmd); +} + +/** + * eeh_restore_bars - Restore the PCI config space info + * @edev: EEH device + * + * This routine performs a recursive walk to the children + * of this device as well. + */ +void eeh_restore_bars(struct eeh_dev *edev) +{ + struct device_node *dn; + if (!edev) + return; + + if ((edev->mode & EEH_MODE_SUPPORTED) && !IS_BRIDGE(edev->class_code)) + eeh_restore_one_device_bars(edev); + + for_each_child_of_node(eeh_dev_to_of_node(edev), dn) + eeh_restore_bars(of_node_to_eeh_dev(dn)); +} + +/** + * 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. + */ +static 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_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) +{ + 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 eeh_dev *edev = of_node_to_eeh_dev(dn); + + edev->class_code = 0; + edev->mode = 0; + edev->check_count = 0; + edev->freeze_count = 0; + edev->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")) { + edev->mode |= EEH_MODE_NOCHECK; + return NULL; + } + edev->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 = eeh_ops->set_option(dn, EEH_OPT_ENABLE); + + enable = 0; + if (ret == 0) { + edev->config_addr = regs[0]; + + /* If the newer, better, ibm,get-config-addr-info is supported, + * then use that instead. + */ + edev->pe_config_addr = eeh_ops->get_pe_addr(dn); + + /* 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_ops->get_state(dn, NULL); + if (ret > 0 && ret != EEH_STATE_NOT_SUPPORT) + enable = 1; + } + + if (enable) { + eeh_subsystem_enabled = 1; + edev->mode |= EEH_MODE_SUPPORTED; + + pr_debug("EEH: %s: eeh enabled, config=%x pe_config=%x\n", + dn->full_name, edev->config_addr, + edev->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 && of_node_to_eeh_dev(dn->parent) && + (of_node_to_eeh_dev(dn->parent)->mode & EEH_MODE_SUPPORTED)) { + /* Parent supports EEH. */ + edev->mode |= EEH_MODE_SUPPORTED; + edev->config_addr = of_node_to_eeh_dev(dn->parent)->config_addr; + return NULL; + } + } + } else { + printk(KERN_WARNING "EEH: %s: unable to get reg property.\n", + dn->full_name); + } + + eeh_save_bars(edev); + return NULL; +} + +/** + * 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. + */ +void __init eeh_init(void) +{ + struct pci_controller *hose, *tmp; + struct device_node *phb; + int ret; + + /* call platform initialization function */ + if (!eeh_ops) { + pr_warning("%s: Platform EEH operation not found\n", + __func__); + return; + } else if ((ret = eeh_ops->init())) { + pr_warning("%s: Failed to call platform init function (%d)\n", + __func__, ret); + return; + } + + raw_spin_lock_init(&confirm_error_lock); + + /* Enable EEH for all adapters */ + list_for_each_entry_safe(hose, tmp, &hose_list, list_node) { + phb = hose->dn; + traverse_pci_devices(phb, eeh_early_enable, NULL); + } + + 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; + + if (!dn || !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_early_enable(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; + + 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 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); + + 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=%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); |