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Diffstat (limited to '')
| -rw-r--r-- | arch/powerpc/kernel/eeh.c | 1941 |
1 files changed, 1941 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c new file mode 100644 index 000000000..ab316e155 --- /dev/null +++ b/arch/powerpc/kernel/eeh.c @@ -0,0 +1,1941 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Copyright IBM Corporation 2001, 2005, 2006 + * Copyright Dave Engebretsen & Todd Inglett 2001 + * Copyright Linas Vepstas 2005, 2006 + * Copyright 2001-2012 IBM Corporation. + * + * Please address comments and feedback to Linas Vepstas <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/iommu.h> +#include <linux/proc_fs.h> +#include <linux/rbtree.h> +#include <linux/reboot.h> +#include <linux/seq_file.h> +#include <linux/spinlock.h> +#include <linux/export.h> +#include <linux/of.h> +#include <linux/debugfs.h> + +#include <linux/atomic.h> +#include <asm/eeh.h> +#include <asm/eeh_event.h> +#include <asm/io.h> +#include <asm/iommu.h> +#include <asm/machdep.h> +#include <asm/ppc-pci.h> +#include <asm/rtas.h> +#include <asm/pte-walk.h> + + +/** Overview: + * EEH, or "Enhanced Error Handling" is a PCI bridge technology for + * dealing with PCI bus errors that can't be dealt with within the + * usual PCI framework, except by check-stopping the CPU. Systems + * that are designed for high-availability/reliability cannot afford + * to crash due to a "mere" PCI error, thus the need for EEH. + * An EEH-capable bridge operates by converting a detected error + * into a "slot freeze", taking the PCI adapter off-line, making + * the slot behave, from the OS'es point of view, as if the slot + * were "empty": all reads return 0xff's and all writes are silently + * ignored. EEH slot isolation events can be triggered by parity + * errors on the address or data busses (e.g. during posted writes), + * which in turn might be caused by low voltage on the bus, dust, + * vibration, humidity, radioactivity or plain-old failed hardware. + * + * Note, however, that one of the leading causes of EEH slot + * freeze events are buggy device drivers, buggy device microcode, + * or buggy device hardware. This is because any attempt by the + * device to bus-master data to a memory address that is not + * assigned to the device will trigger a slot freeze. (The idea + * is to prevent devices-gone-wild from corrupting system memory). + * Buggy hardware/drivers will have a miserable time co-existing + * with EEH. + * + * Ideally, a PCI device driver, when suspecting that an isolation + * event has occurred (e.g. by reading 0xff's), will then ask EEH + * whether this is the case, and then take appropriate steps to + * reset the PCI slot, the PCI device, and then resume operations. + * However, until that day, the checking is done here, with the + * eeh_check_failure() routine embedded in the MMIO macros. If + * the slot is found to be isolated, an "EEH Event" is synthesized + * and sent out for processing. + */ + +/* If a device driver keeps reading an MMIO register in an interrupt + * handler after a slot isolation event, it might be broken. + * This sets the threshold for how many read attempts we allow + * before printing an error message. + */ +#define EEH_MAX_FAILS 2100000 + +/* Time to wait for a PCI slot to report status, in milliseconds */ +#define PCI_BUS_RESET_WAIT_MSEC (5*60*1000) + +/* + * EEH probe mode support, which is part of the flags, + * is to support multiple platforms for EEH. Some platforms + * like pSeries do PCI emunation based on device tree. + * However, other platforms like powernv probe PCI devices + * from hardware. The flag is used to distinguish that. + * In addition, struct eeh_ops::probe would be invoked for + * particular OF node or PCI device so that the corresponding + * PE would be created there. + */ +int eeh_subsystem_flags; +EXPORT_SYMBOL(eeh_subsystem_flags); + +/* + * EEH allowed maximal frozen times. If one particular PE's + * frozen count in last hour exceeds this limit, the PE will + * be forced to be offline permanently. + */ +u32 eeh_max_freezes = 5; + +/* + * Controls whether a recovery event should be scheduled when an + * isolated device is discovered. This is only really useful for + * debugging problems with the EEH core. + */ +bool eeh_debugfs_no_recover; + +/* Platform dependent EEH operations */ +struct eeh_ops *eeh_ops = NULL; + +/* Lock to avoid races due to multiple reports of an error */ +DEFINE_RAW_SPINLOCK(confirm_error_lock); +EXPORT_SYMBOL_GPL(confirm_error_lock); + +/* Lock to protect passed flags */ +static DEFINE_MUTEX(eeh_dev_mutex); + +/* Buffer for reporting pci register dumps. Its here in BSS, and + * not dynamically alloced, so that it ends up in RMO where RTAS + * can access it. + */ +#define EEH_PCI_REGS_LOG_LEN 8192 +static unsigned char pci_regs_buf[EEH_PCI_REGS_LOG_LEN]; + +/* + * The struct is used to maintain the EEH global statistic + * information. Besides, the EEH global statistics will be + * exported to user space through procfs + */ +struct eeh_stats { + u64 no_device; /* PCI device not found */ + u64 no_dn; /* OF node not found */ + u64 no_cfg_addr; /* Config address not found */ + u64 ignored_check; /* EEH check skipped */ + u64 total_mmio_ffs; /* Total EEH checks */ + u64 false_positives; /* Unnecessary EEH checks */ + u64 slot_resets; /* PE reset */ +}; + +static struct eeh_stats eeh_stats; + +static int __init eeh_setup(char *str) +{ + if (!strcmp(str, "off")) + eeh_add_flag(EEH_FORCE_DISABLED); + else if (!strcmp(str, "early_log")) + eeh_add_flag(EEH_EARLY_DUMP_LOG); + + return 1; +} +__setup("eeh=", eeh_setup); + +void eeh_show_enabled(void) +{ + if (eeh_has_flag(EEH_FORCE_DISABLED)) + pr_info("EEH: Recovery disabled by kernel parameter.\n"); + else if (eeh_has_flag(EEH_ENABLED)) + pr_info("EEH: Capable adapter found: recovery enabled.\n"); + else + pr_info("EEH: No capable adapters found: recovery disabled.\n"); +} + +/* + * This routine captures assorted PCI configuration space data + * for the indicated PCI device, and puts them into a buffer + * for RTAS error logging. + */ +static size_t eeh_dump_dev_log(struct eeh_dev *edev, char *buf, size_t len) +{ + u32 cfg; + int cap, i; + int n = 0, l = 0; + char buffer[128]; + + n += scnprintf(buf+n, len-n, "%04x:%02x:%02x.%01x\n", + edev->pe->phb->global_number, edev->bdfn >> 8, + PCI_SLOT(edev->bdfn), PCI_FUNC(edev->bdfn)); + pr_warn("EEH: of node=%04x:%02x:%02x.%01x\n", + edev->pe->phb->global_number, edev->bdfn >> 8, + PCI_SLOT(edev->bdfn), PCI_FUNC(edev->bdfn)); + + eeh_ops->read_config(edev, PCI_VENDOR_ID, 4, &cfg); + n += scnprintf(buf+n, len-n, "dev/vend:%08x\n", cfg); + pr_warn("EEH: PCI device/vendor: %08x\n", cfg); + + eeh_ops->read_config(edev, PCI_COMMAND, 4, &cfg); + n += scnprintf(buf+n, len-n, "cmd/stat:%x\n", cfg); + pr_warn("EEH: PCI cmd/status register: %08x\n", cfg); + + /* Gather bridge-specific registers */ + if (edev->mode & EEH_DEV_BRIDGE) { + eeh_ops->read_config(edev, PCI_SEC_STATUS, 2, &cfg); + n += scnprintf(buf+n, len-n, "sec stat:%x\n", cfg); + pr_warn("EEH: Bridge secondary status: %04x\n", cfg); + + eeh_ops->read_config(edev, PCI_BRIDGE_CONTROL, 2, &cfg); + n += scnprintf(buf+n, len-n, "brdg ctl:%x\n", cfg); + pr_warn("EEH: Bridge control: %04x\n", cfg); + } + + /* Dump out the PCI-X command and status regs */ + cap = edev->pcix_cap; + if (cap) { + eeh_ops->read_config(edev, cap, 4, &cfg); + n += scnprintf(buf+n, len-n, "pcix-cmd:%x\n", cfg); + pr_warn("EEH: PCI-X cmd: %08x\n", cfg); + + eeh_ops->read_config(edev, cap+4, 4, &cfg); + n += scnprintf(buf+n, len-n, "pcix-stat:%x\n", cfg); + pr_warn("EEH: PCI-X status: %08x\n", cfg); + } + + /* If PCI-E capable, dump PCI-E cap 10 */ + cap = edev->pcie_cap; + if (cap) { + n += scnprintf(buf+n, len-n, "pci-e cap10:\n"); + pr_warn("EEH: PCI-E capabilities and status follow:\n"); + + for (i=0; i<=8; i++) { + eeh_ops->read_config(edev, cap+4*i, 4, &cfg); + n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg); + + if ((i % 4) == 0) { + if (i != 0) + pr_warn("%s\n", buffer); + + l = scnprintf(buffer, sizeof(buffer), + "EEH: PCI-E %02x: %08x ", + 4*i, cfg); + } else { + l += scnprintf(buffer+l, sizeof(buffer)-l, + "%08x ", cfg); + } + + } + + pr_warn("%s\n", buffer); + } + + /* If AER capable, dump it */ + cap = edev->aer_cap; + if (cap) { + n += scnprintf(buf+n, len-n, "pci-e AER:\n"); + pr_warn("EEH: PCI-E AER capability register set follows:\n"); + + for (i=0; i<=13; i++) { + eeh_ops->read_config(edev, cap+4*i, 4, &cfg); + n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg); + + if ((i % 4) == 0) { + if (i != 0) + pr_warn("%s\n", buffer); + + l = scnprintf(buffer, sizeof(buffer), + "EEH: PCI-E AER %02x: %08x ", + 4*i, cfg); + } else { + l += scnprintf(buffer+l, sizeof(buffer)-l, + "%08x ", cfg); + } + } + + pr_warn("%s\n", buffer); + } + + return n; +} + +static void *eeh_dump_pe_log(struct eeh_pe *pe, void *flag) +{ + struct eeh_dev *edev, *tmp; + size_t *plen = flag; + + eeh_pe_for_each_dev(pe, edev, tmp) + *plen += eeh_dump_dev_log(edev, pci_regs_buf + *plen, + EEH_PCI_REGS_LOG_LEN - *plen); + + return NULL; +} + +/** + * eeh_slot_error_detail - Generate combined log including driver log and error log + * @pe: EEH PE + * @severity: temporary or permanent error log + * + * This routine should be called to generate the combined log, which + * is comprised of driver log and error log. The driver log is figured + * out from the config space of the corresponding PCI device, while + * the error log is fetched through platform dependent function call. + */ +void eeh_slot_error_detail(struct eeh_pe *pe, int severity) +{ + size_t loglen = 0; + + /* + * When the PHB is fenced or dead, it's pointless to collect + * the data from PCI config space because it should return + * 0xFF's. For ER, we still retrieve the data from the PCI + * config space. + * + * For pHyp, we have to enable IO for log retrieval. Otherwise, + * 0xFF's is always returned from PCI config space. + * + * When the @severity is EEH_LOG_PERM, the PE is going to be + * removed. Prior to that, the drivers for devices included in + * the PE will be closed. The drivers rely on working IO path + * to bring the devices to quiet state. Otherwise, PCI traffic + * from those devices after they are removed is like to cause + * another unexpected EEH error. + */ + if (!(pe->type & EEH_PE_PHB)) { + if (eeh_has_flag(EEH_ENABLE_IO_FOR_LOG) || + severity == EEH_LOG_PERM) + eeh_pci_enable(pe, EEH_OPT_THAW_MMIO); + + /* + * The config space of some PCI devices can't be accessed + * when their PEs are in frozen state. Otherwise, fenced + * PHB might be seen. Those PEs are identified with flag + * EEH_PE_CFG_RESTRICTED, indicating EEH_PE_CFG_BLOCKED + * is set automatically when the PE is put to EEH_PE_ISOLATED. + * + * Restoring BARs possibly triggers PCI config access in + * (OPAL) firmware and then causes fenced PHB. If the + * PCI config is blocked with flag EEH_PE_CFG_BLOCKED, it's + * pointless to restore BARs and dump config space. + */ + eeh_ops->configure_bridge(pe); + if (!(pe->state & EEH_PE_CFG_BLOCKED)) { + eeh_pe_restore_bars(pe); + + pci_regs_buf[0] = 0; + eeh_pe_traverse(pe, eeh_dump_pe_log, &loglen); + } + } + + eeh_ops->get_log(pe, severity, pci_regs_buf, loglen); +} + +/** + * eeh_token_to_phys - Convert EEH address token to phys address + * @token: I/O token, should be address in the form 0xA.... + * + * This routine should be called to convert virtual I/O address + * to physical one. + */ +static inline unsigned long eeh_token_to_phys(unsigned long token) +{ + return ppc_find_vmap_phys(token); +} + +/* + * On PowerNV platform, we might already have fenced PHB there. + * For that case, it's meaningless to recover frozen PE. Intead, + * We have to handle fenced PHB firstly. + */ +static int eeh_phb_check_failure(struct eeh_pe *pe) +{ + struct eeh_pe *phb_pe; + unsigned long flags; + int ret; + + if (!eeh_has_flag(EEH_PROBE_MODE_DEV)) + return -EPERM; + + /* Find the PHB PE */ + phb_pe = eeh_phb_pe_get(pe->phb); + if (!phb_pe) { + pr_warn("%s Can't find PE for PHB#%x\n", + __func__, pe->phb->global_number); + return -EEXIST; + } + + /* If the PHB has been in problematic state */ + eeh_serialize_lock(&flags); + if (phb_pe->state & EEH_PE_ISOLATED) { + ret = 0; + goto out; + } + + /* Check PHB state */ + ret = eeh_ops->get_state(phb_pe, NULL); + if ((ret < 0) || + (ret == EEH_STATE_NOT_SUPPORT) || eeh_state_active(ret)) { + ret = 0; + goto out; + } + + /* Isolate the PHB and send event */ + eeh_pe_mark_isolated(phb_pe); + eeh_serialize_unlock(flags); + + pr_debug("EEH: PHB#%x failure detected, location: %s\n", + phb_pe->phb->global_number, eeh_pe_loc_get(phb_pe)); + eeh_send_failure_event(phb_pe); + return 1; +out: + eeh_serialize_unlock(flags); + return ret; +} + +static inline const char *eeh_driver_name(struct pci_dev *pdev) +{ + if (pdev) + return dev_driver_string(&pdev->dev); + + return "<null>"; +} + +/** + * eeh_dev_check_failure - Check if all 1's data is due to EEH slot freeze + * @edev: eeh device + * + * Check for an EEH failure for the given device node. Call this + * routine if the result of a read was all 0xff's and you want to + * find out if this is due to an EEH slot freeze. This routine + * will query firmware for the EEH status. + * + * Returns 0 if there has not been an EEH error; otherwise returns + * a non-zero value and queues up a slot isolation event notification. + * + * It is safe to call this routine in an interrupt context. + */ +int eeh_dev_check_failure(struct eeh_dev *edev) +{ + int ret; + unsigned long flags; + struct device_node *dn; + struct pci_dev *dev; + struct eeh_pe *pe, *parent_pe; + int rc = 0; + const char *location = NULL; + + eeh_stats.total_mmio_ffs++; + + if (!eeh_enabled()) + return 0; + + if (!edev) { + eeh_stats.no_dn++; + return 0; + } + dev = eeh_dev_to_pci_dev(edev); + pe = eeh_dev_to_pe(edev); + + /* Access to IO BARs might get this far and still not want checking. */ + if (!pe) { + eeh_stats.ignored_check++; + eeh_edev_dbg(edev, "Ignored check\n"); + return 0; + } + + /* + * On PowerNV platform, we might already have fenced PHB + * there and we need take care of that firstly. + */ + ret = eeh_phb_check_failure(pe); + if (ret > 0) + return ret; + + /* + * If the PE isn't owned by us, we shouldn't check the + * state. Instead, let the owner handle it if the PE has + * been frozen. + */ + if (eeh_pe_passed(pe)) + return 0; + + /* If we already have a pending isolation event for this + * slot, we know it's bad already, we don't need to check. + * Do this checking under a lock; as multiple PCI devices + * in one slot might report errors simultaneously, and we + * only want one error recovery routine running. + */ + eeh_serialize_lock(&flags); + rc = 1; + if (pe->state & EEH_PE_ISOLATED) { + pe->check_count++; + if (pe->check_count == EEH_MAX_FAILS) { + dn = pci_device_to_OF_node(dev); + if (dn) + location = of_get_property(dn, "ibm,loc-code", + NULL); + eeh_edev_err(edev, "%d reads ignored for recovering device at location=%s driver=%s\n", + pe->check_count, + location ? location : "unknown", + eeh_driver_name(dev)); + eeh_edev_err(edev, "Might be infinite loop in %s driver\n", + eeh_driver_name(dev)); + dump_stack(); + } + goto dn_unlock; + } + + /* + * Now test for an EEH failure. This is VERY expensive. + * Note that the eeh_config_addr may be a parent device + * in the case of a device behind a bridge, or it may be + * function zero of a multi-function device. + * In any case they must share a common PHB. + */ + ret = eeh_ops->get_state(pe, NULL); + + /* Note that config-io to empty slots may fail; + * they are empty when they don't have children. + * We will punt with the following conditions: Failure to get + * PE's state, EEH not support and Permanently unavailable + * state, PE is in good state. + */ + if ((ret < 0) || + (ret == EEH_STATE_NOT_SUPPORT) || eeh_state_active(ret)) { + eeh_stats.false_positives++; + pe->false_positives++; + rc = 0; + goto dn_unlock; + } + + /* + * It should be corner case that the parent PE has been + * put into frozen state as well. We should take care + * that at first. + */ + parent_pe = pe->parent; + while (parent_pe) { + /* Hit the ceiling ? */ + if (parent_pe->type & EEH_PE_PHB) + break; + + /* Frozen parent PE ? */ + ret = eeh_ops->get_state(parent_pe, NULL); + if (ret > 0 && !eeh_state_active(ret)) { + pe = parent_pe; + pr_err("EEH: Failure of PHB#%x-PE#%x will be handled at parent PHB#%x-PE#%x.\n", + pe->phb->global_number, pe->addr, + pe->phb->global_number, parent_pe->addr); + } + + /* Next parent level */ + parent_pe = parent_pe->parent; + } + + eeh_stats.slot_resets++; + + /* Avoid repeated reports of this failure, including problems + * with other functions on this device, and functions under + * bridges. + */ + eeh_pe_mark_isolated(pe); + eeh_serialize_unlock(flags); + + /* Most EEH events are due to device driver bugs. Having + * a stack trace will help the device-driver authors figure + * out what happened. So print that out. + */ + pr_debug("EEH: %s: Frozen PHB#%x-PE#%x detected\n", + __func__, pe->phb->global_number, pe->addr); + eeh_send_failure_event(pe); + + return 1; + +dn_unlock: + eeh_serialize_unlock(flags); + return rc; +} + +EXPORT_SYMBOL_GPL(eeh_dev_check_failure); + +/** + * eeh_check_failure - Check if all 1's data is due to EEH slot freeze + * @token: I/O address + * + * Check for an EEH failure at the given I/O address. Call this + * routine if the result of a read was all 0xff's and you want to + * find out if this is due to an EEH slot freeze event. This routine + * will query firmware for the EEH status. + * + * Note this routine is safe to call in an interrupt context. + */ +int eeh_check_failure(const volatile void __iomem *token) +{ + unsigned long addr; + struct eeh_dev *edev; + + /* Finding the phys addr + pci device; this is pretty quick. */ + addr = eeh_token_to_phys((unsigned long __force) token); + edev = eeh_addr_cache_get_dev(addr); + if (!edev) { + eeh_stats.no_device++; + return 0; + } + + return eeh_dev_check_failure(edev); +} +EXPORT_SYMBOL(eeh_check_failure); + + +/** + * eeh_pci_enable - Enable MMIO or DMA transfers for this slot + * @pe: EEH PE + * @function: EEH option + * + * This routine should be called to reenable frozen MMIO or DMA + * so that it would work correctly again. It's useful while doing + * recovery or log collection on the indicated device. + */ +int eeh_pci_enable(struct eeh_pe *pe, int function) +{ + int active_flag, rc; + + /* + * pHyp doesn't allow to enable IO or DMA on unfrozen PE. + * Also, it's pointless to enable them on unfrozen PE. So + * we have to check before enabling IO or DMA. + */ + switch (function) { + case EEH_OPT_THAW_MMIO: + active_flag = EEH_STATE_MMIO_ACTIVE | EEH_STATE_MMIO_ENABLED; + break; + case EEH_OPT_THAW_DMA: + active_flag = EEH_STATE_DMA_ACTIVE; + break; + case EEH_OPT_DISABLE: + case EEH_OPT_ENABLE: + case EEH_OPT_FREEZE_PE: + active_flag = 0; + break; + default: + pr_warn("%s: Invalid function %d\n", + __func__, function); + return -EINVAL; + } + + /* + * Check if IO or DMA has been enabled before + * enabling them. + */ + if (active_flag) { + rc = eeh_ops->get_state(pe, NULL); + if (rc < 0) + return rc; + + /* Needn't enable it at all */ + if (rc == EEH_STATE_NOT_SUPPORT) + return 0; + + /* It's already enabled */ + if (rc & active_flag) + return 0; + } + + + /* Issue the request */ + rc = eeh_ops->set_option(pe, function); + if (rc) + pr_warn("%s: Unexpected state change %d on " + "PHB#%x-PE#%x, err=%d\n", + __func__, function, pe->phb->global_number, + pe->addr, rc); + + /* Check if the request is finished successfully */ + if (active_flag) { + rc = eeh_wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); + if (rc < 0) + return rc; + + if (rc & active_flag) + return 0; + + return -EIO; + } + + return rc; +} + +static void eeh_disable_and_save_dev_state(struct eeh_dev *edev, + void *userdata) +{ + struct pci_dev *pdev = eeh_dev_to_pci_dev(edev); + struct pci_dev *dev = userdata; + + /* + * The caller should have disabled and saved the + * state for the specified device + */ + if (!pdev || pdev == dev) + return; + + /* Ensure we have D0 power state */ + pci_set_power_state(pdev, PCI_D0); + + /* Save device state */ + pci_save_state(pdev); + + /* + * Disable device to avoid any DMA traffic and + * interrupt from the device + */ + pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE); +} + +static void eeh_restore_dev_state(struct eeh_dev *edev, void *userdata) +{ + struct pci_dev *pdev = eeh_dev_to_pci_dev(edev); + struct pci_dev *dev = userdata; + + if (!pdev) + return; + + /* Apply customization from firmware */ + if (eeh_ops->restore_config) + eeh_ops->restore_config(edev); + + /* The caller should restore state for the specified device */ + if (pdev != dev) + pci_restore_state(pdev); +} + +/** + * pcibios_set_pcie_reset_state - Set PCI-E reset state + * @dev: pci device struct + * @state: reset state to enter + * + * Return value: + * 0 if success + */ +int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) +{ + struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); + struct eeh_pe *pe = eeh_dev_to_pe(edev); + + if (!pe) { + pr_err("%s: No PE found on PCI device %s\n", + __func__, pci_name(dev)); + return -EINVAL; + } + + switch (state) { + case pcie_deassert_reset: + eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); + eeh_unfreeze_pe(pe); + if (!(pe->type & EEH_PE_VF)) + eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, true); + eeh_pe_dev_traverse(pe, eeh_restore_dev_state, dev); + eeh_pe_state_clear(pe, EEH_PE_ISOLATED, true); + break; + case pcie_hot_reset: + eeh_pe_mark_isolated(pe); + eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, true); + eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE); + eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev); + if (!(pe->type & EEH_PE_VF)) + eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED); + eeh_ops->reset(pe, EEH_RESET_HOT); + break; + case pcie_warm_reset: + eeh_pe_mark_isolated(pe); + eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, true); + eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE); + eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev); + if (!(pe->type & EEH_PE_VF)) + eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED); + eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL); + break; + default: + eeh_pe_state_clear(pe, EEH_PE_ISOLATED | EEH_PE_CFG_BLOCKED, true); + return -EINVAL; + } + + return 0; +} + +/** + * eeh_set_dev_freset - Check the required reset for the indicated device + * @edev: EEH device + * @flag: return value + * + * Each device might have its preferred reset type: fundamental or + * hot reset. The routine is used to collected the information for + * the indicated device and its children so that the bunch of the + * devices could be reset properly. + */ +static void eeh_set_dev_freset(struct eeh_dev *edev, void *flag) +{ + struct pci_dev *dev; + unsigned int *freset = (unsigned int *)flag; + + dev = eeh_dev_to_pci_dev(edev); + if (dev) + *freset |= dev->needs_freset; +} + +static void eeh_pe_refreeze_passed(struct eeh_pe *root) +{ + struct eeh_pe *pe; + int state; + + eeh_for_each_pe(root, pe) { + if (eeh_pe_passed(pe)) { + state = eeh_ops->get_state(pe, NULL); + if (state & + (EEH_STATE_MMIO_ACTIVE | EEH_STATE_MMIO_ENABLED)) { + pr_info("EEH: Passed-through PE PHB#%x-PE#%x was thawed by reset, re-freezing for safety.\n", + pe->phb->global_number, pe->addr); + eeh_pe_set_option(pe, EEH_OPT_FREEZE_PE); + } + } + } +} + +/** + * eeh_pe_reset_full - Complete a full reset process on the indicated PE + * @pe: EEH PE + * @include_passed: include passed-through devices? + * + * This function executes a full reset procedure on a PE, including setting + * the appropriate flags, performing a fundamental or hot reset, and then + * deactivating the reset status. It is designed to be used within the EEH + * subsystem, as opposed to eeh_pe_reset which is exported to drivers and + * only performs a single operation at a time. + * + * This function will attempt to reset a PE three times before failing. + */ +int eeh_pe_reset_full(struct eeh_pe *pe, bool include_passed) +{ + int reset_state = (EEH_PE_RESET | EEH_PE_CFG_BLOCKED); + int type = EEH_RESET_HOT; + unsigned int freset = 0; + int i, state = 0, ret; + + /* + * Determine the type of reset to perform - hot or fundamental. + * Hot reset is the default operation, unless any device under the + * PE requires a fundamental reset. + */ + eeh_pe_dev_traverse(pe, eeh_set_dev_freset, &freset); + + if (freset) + type = EEH_RESET_FUNDAMENTAL; + + /* Mark the PE as in reset state and block config space accesses */ + eeh_pe_state_mark(pe, reset_state); + + /* Make three attempts at resetting the bus */ + for (i = 0; i < 3; i++) { + ret = eeh_pe_reset(pe, type, include_passed); + if (!ret) + ret = eeh_pe_reset(pe, EEH_RESET_DEACTIVATE, + include_passed); + if (ret) { + ret = -EIO; + pr_warn("EEH: Failure %d resetting PHB#%x-PE#%x (attempt %d)\n\n", + state, pe->phb->global_number, pe->addr, i + 1); + continue; + } + if (i) + pr_warn("EEH: PHB#%x-PE#%x: Successful reset (attempt %d)\n", + pe->phb->global_number, pe->addr, i + 1); + + /* Wait until the PE is in a functioning state */ + state = eeh_wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); + if (state < 0) { + pr_warn("EEH: Unrecoverable slot failure on PHB#%x-PE#%x", + pe->phb->global_number, pe->addr); + ret = -ENOTRECOVERABLE; + break; + } + if (eeh_state_active(state)) + break; + else + pr_warn("EEH: PHB#%x-PE#%x: Slot inactive after reset: 0x%x (attempt %d)\n", + pe->phb->global_number, pe->addr, state, i + 1); + } + + /* Resetting the PE may have unfrozen child PEs. If those PEs have been + * (potentially) passed through to a guest, re-freeze them: + */ + if (!include_passed) + eeh_pe_refreeze_passed(pe); + + eeh_pe_state_clear(pe, reset_state, true); + return ret; +} + +/** + * eeh_save_bars - Save device bars + * @edev: PCI device associated EEH device + * + * Save the values of the device bars. Unlike the restore + * routine, this routine is *not* recursive. This is because + * PCI devices are added individually; but, for the restore, + * an entire slot is reset at a time. + */ +void eeh_save_bars(struct eeh_dev *edev) +{ + int i; + + if (!edev) + return; + + for (i = 0; i < 16; i++) + eeh_ops->read_config(edev, i * 4, 4, &edev->config_space[i]); + + /* + * For PCI bridges including root port, we need enable bus + * master explicitly. Otherwise, it can't fetch IODA table + * entries correctly. So we cache the bit in advance so that + * we can restore it after reset, either PHB range or PE range. + */ + if (edev->mode & EEH_DEV_BRIDGE) + edev->config_space[1] |= PCI_COMMAND_MASTER; +} + +static int eeh_reboot_notifier(struct notifier_block *nb, + unsigned long action, void *unused) +{ + eeh_clear_flag(EEH_ENABLED); + return NOTIFY_DONE; +} + +static struct notifier_block eeh_reboot_nb = { + .notifier_call = eeh_reboot_notifier, +}; + +static int eeh_device_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *dev = data; + + switch (action) { + /* + * Note: It's not possible to perform EEH device addition (i.e. + * {pseries,pnv}_pcibios_bus_add_device()) here because it depends on + * the device's resources, which have not yet been set up. + */ + case BUS_NOTIFY_DEL_DEVICE: + eeh_remove_device(to_pci_dev(dev)); + break; + default: + break; + } + return NOTIFY_DONE; +} + +static struct notifier_block eeh_device_nb = { + .notifier_call = eeh_device_notifier, +}; + +/** + * eeh_init - System wide EEH initialization + * @ops: struct to trace EEH operation callback functions + * + * It's the platform's job to call this from an arch_initcall(). + */ +int eeh_init(struct eeh_ops *ops) +{ + struct pci_controller *hose, *tmp; + int ret = 0; + + /* the platform should only initialise EEH once */ + if (WARN_ON(eeh_ops)) + return -EEXIST; + if (WARN_ON(!ops)) + return -ENOENT; + eeh_ops = ops; + + /* Register reboot notifier */ + ret = register_reboot_notifier(&eeh_reboot_nb); + if (ret) { + pr_warn("%s: Failed to register reboot notifier (%d)\n", + __func__, ret); + return ret; + } + + ret = bus_register_notifier(&pci_bus_type, &eeh_device_nb); + if (ret) { + pr_warn("%s: Failed to register bus notifier (%d)\n", + __func__, ret); + return ret; + } + + /* Initialize PHB PEs */ + list_for_each_entry_safe(hose, tmp, &hose_list, list_node) + eeh_phb_pe_create(hose); + + eeh_addr_cache_init(); + + /* Initialize EEH event */ + return eeh_event_init(); +} + +/** + * eeh_probe_device() - Perform EEH initialization for the indicated pci device + * @dev: pci device for which to set up EEH + * + * This routine must be used to complete EEH initialization for PCI + * devices that were added after system boot (e.g. hotplug, dlpar). + */ +void eeh_probe_device(struct pci_dev *dev) +{ + struct eeh_dev *edev; + + pr_debug("EEH: Adding device %s\n", pci_name(dev)); + + /* + * pci_dev_to_eeh_dev() can only work if eeh_probe_dev() was + * already called for this device. + */ + if (WARN_ON_ONCE(pci_dev_to_eeh_dev(dev))) { + pci_dbg(dev, "Already bound to an eeh_dev!\n"); + return; + } + + edev = eeh_ops->probe(dev); + if (!edev) { + pr_debug("EEH: Adding device failed\n"); + return; + } + + /* + * FIXME: We rely on pcibios_release_device() to remove the + * existing EEH state. The release function is only called if + * the pci_dev's refcount drops to zero so if something is + * keeping a ref to a device (e.g. a filesystem) we need to + * remove the old EEH state. + * + * FIXME: HEY MA, LOOK AT ME, NO LOCKING! + */ + if (edev->pdev && edev->pdev != dev) { + eeh_pe_tree_remove(edev); + eeh_addr_cache_rmv_dev(edev->pdev); + eeh_sysfs_remove_device(edev->pdev); + + /* + * We definitely should have the PCI device removed + * though it wasn't correctly. So we needn't call + * into error handler afterwards. + */ + edev->mode |= EEH_DEV_NO_HANDLER; + } + + /* bind the pdev and the edev together */ + edev->pdev = dev; + dev->dev.archdata.edev = edev; + eeh_addr_cache_insert_dev(dev); + eeh_sysfs_add_device(dev); +} + +/** + * eeh_remove_device - Undo EEH setup for the indicated pci device + * @dev: pci device to be removed + * + * This routine should be called when a device is removed from + * a running system (e.g. by hotplug or dlpar). It unregisters + * the PCI device from the EEH subsystem. I/O errors affecting + * this device will no longer be detected after this call; thus, + * i/o errors affecting this slot may leave this device unusable. + */ +void eeh_remove_device(struct pci_dev *dev) +{ + struct eeh_dev *edev; + + if (!dev || !eeh_enabled()) + return; + edev = pci_dev_to_eeh_dev(dev); + + /* Unregister the device with the EEH/PCI address search system */ + dev_dbg(&dev->dev, "EEH: Removing device\n"); + + if (!edev || !edev->pdev || !edev->pe) { + dev_dbg(&dev->dev, "EEH: Device not referenced!\n"); + return; + } + + /* + * During the hotplug for EEH error recovery, we need the EEH + * device attached to the parent PE in order for BAR restore + * a bit later. So we keep it for BAR restore and remove it + * from the parent PE during the BAR resotre. + */ + edev->pdev = NULL; + + /* + * eeh_sysfs_remove_device() uses pci_dev_to_eeh_dev() so we need to + * remove the sysfs files before clearing dev.archdata.edev + */ + if (edev->mode & EEH_DEV_SYSFS) + eeh_sysfs_remove_device(dev); + + /* + * We're removing from the PCI subsystem, that means + * the PCI device driver can't support EEH or not + * well. So we rely on hotplug completely to do recovery + * for the specific PCI device. + */ + edev->mode |= EEH_DEV_NO_HANDLER; + + eeh_addr_cache_rmv_dev(dev); + + /* + * The flag "in_error" is used to trace EEH devices for VFs + * in error state or not. It's set in eeh_report_error(). If + * it's not set, eeh_report_{reset,resume}() won't be called + * for the VF EEH device. + */ + edev->in_error = false; + dev->dev.archdata.edev = NULL; + if (!(edev->pe->state & EEH_PE_KEEP)) + eeh_pe_tree_remove(edev); + else + edev->mode |= EEH_DEV_DISCONNECTED; +} + +int eeh_unfreeze_pe(struct eeh_pe *pe) +{ + int ret; + + ret = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO); + if (ret) { + pr_warn("%s: Failure %d enabling IO on PHB#%x-PE#%x\n", + __func__, ret, pe->phb->global_number, pe->addr); + return ret; + } + + ret = eeh_pci_enable(pe, EEH_OPT_THAW_DMA); + if (ret) { + pr_warn("%s: Failure %d enabling DMA on PHB#%x-PE#%x\n", + __func__, ret, pe->phb->global_number, pe->addr); + return ret; + } + + return ret; +} + + +static struct pci_device_id eeh_reset_ids[] = { + { PCI_DEVICE(0x19a2, 0x0710) }, /* Emulex, BE */ + { PCI_DEVICE(0x10df, 0xe220) }, /* Emulex, Lancer */ + { PCI_DEVICE(0x14e4, 0x1657) }, /* Broadcom BCM5719 */ + { 0 } +}; + +static int eeh_pe_change_owner(struct eeh_pe *pe) +{ + struct eeh_dev *edev, *tmp; + struct pci_dev *pdev; + struct pci_device_id *id; + int ret; + + /* Check PE state */ + ret = eeh_ops->get_state(pe, NULL); + if (ret < 0 || ret == EEH_STATE_NOT_SUPPORT) + return 0; + + /* Unfrozen PE, nothing to do */ + if (eeh_state_active(ret)) + return 0; + + /* Frozen PE, check if it needs PE level reset */ + eeh_pe_for_each_dev(pe, edev, tmp) { + pdev = eeh_dev_to_pci_dev(edev); + if (!pdev) + continue; + + for (id = &eeh_reset_ids[0]; id->vendor != 0; id++) { + if (id->vendor != PCI_ANY_ID && + id->vendor != pdev->vendor) + continue; + if (id->device != PCI_ANY_ID && + id->device != pdev->device) + continue; + if (id->subvendor != PCI_ANY_ID && + id->subvendor != pdev->subsystem_vendor) + continue; + if (id->subdevice != PCI_ANY_ID && + id->subdevice != pdev->subsystem_device) + continue; + + return eeh_pe_reset_and_recover(pe); + } + } + + ret = eeh_unfreeze_pe(pe); + if (!ret) + eeh_pe_state_clear(pe, EEH_PE_ISOLATED, true); + return ret; +} + +/** + * eeh_dev_open - Increase count of pass through devices for PE + * @pdev: PCI device + * + * Increase count of passed through devices for the indicated + * PE. In the result, the EEH errors detected on the PE won't be + * reported. The PE owner will be responsible for detection + * and recovery. + */ +int eeh_dev_open(struct pci_dev *pdev) +{ + struct eeh_dev *edev; + int ret = -ENODEV; + + mutex_lock(&eeh_dev_mutex); + + /* No PCI device ? */ + if (!pdev) + goto out; + + /* No EEH device or PE ? */ + edev = pci_dev_to_eeh_dev(pdev); + if (!edev || !edev->pe) + goto out; + + /* + * The PE might have been put into frozen state, but we + * didn't detect that yet. The passed through PCI devices + * in frozen PE won't work properly. Clear the frozen state + * in advance. + */ + ret = eeh_pe_change_owner(edev->pe); + if (ret) + goto out; + + /* Increase PE's pass through count */ + atomic_inc(&edev->pe->pass_dev_cnt); + mutex_unlock(&eeh_dev_mutex); + + return 0; +out: + mutex_unlock(&eeh_dev_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(eeh_dev_open); + +/** + * eeh_dev_release - Decrease count of pass through devices for PE + * @pdev: PCI device + * + * Decrease count of pass through devices for the indicated PE. If + * there is no passed through device in PE, the EEH errors detected + * on the PE will be reported and handled as usual. + */ +void eeh_dev_release(struct pci_dev *pdev) +{ + struct eeh_dev *edev; + + mutex_lock(&eeh_dev_mutex); + + /* No PCI device ? */ + if (!pdev) + goto out; + + /* No EEH device ? */ + edev = pci_dev_to_eeh_dev(pdev); + if (!edev || !edev->pe || !eeh_pe_passed(edev->pe)) + goto out; + + /* Decrease PE's pass through count */ + WARN_ON(atomic_dec_if_positive(&edev->pe->pass_dev_cnt) < 0); + eeh_pe_change_owner(edev->pe); +out: + mutex_unlock(&eeh_dev_mutex); +} +EXPORT_SYMBOL(eeh_dev_release); + +#ifdef CONFIG_IOMMU_API + +static int dev_has_iommu_table(struct device *dev, void *data) +{ + struct pci_dev *pdev = to_pci_dev(dev); + struct pci_dev **ppdev = data; + + if (!dev) + return 0; + + if (device_iommu_mapped(dev)) { + *ppdev = pdev; + return 1; + } + + return 0; +} + +/** + * eeh_iommu_group_to_pe - Convert IOMMU group to EEH PE + * @group: IOMMU group + * + * The routine is called to convert IOMMU group to EEH PE. + */ +struct eeh_pe *eeh_iommu_group_to_pe(struct iommu_group *group) +{ + struct pci_dev *pdev = NULL; + struct eeh_dev *edev; + int ret; + + /* No IOMMU group ? */ + if (!group) + return NULL; + + ret = iommu_group_for_each_dev(group, &pdev, dev_has_iommu_table); + if (!ret || !pdev) + return NULL; + + /* No EEH device or PE ? */ + edev = pci_dev_to_eeh_dev(pdev); + if (!edev || !edev->pe) + return NULL; + + return edev->pe; +} +EXPORT_SYMBOL_GPL(eeh_iommu_group_to_pe); + +#endif /* CONFIG_IOMMU_API */ + +/** + * eeh_pe_set_option - Set options for the indicated PE + * @pe: EEH PE + * @option: requested option + * + * The routine is called to enable or disable EEH functionality + * on the indicated PE, to enable IO or DMA for the frozen PE. + */ +int eeh_pe_set_option(struct eeh_pe *pe, int option) +{ + int ret = 0; + + /* Invalid PE ? */ + if (!pe) + return -ENODEV; + + /* + * EEH functionality could possibly be disabled, just + * return error for the case. And the EEH functionality + * isn't expected to be disabled on one specific PE. + */ + switch (option) { + case EEH_OPT_ENABLE: + if (eeh_enabled()) { + ret = eeh_pe_change_owner(pe); + break; + } + ret = -EIO; + break; + case EEH_OPT_DISABLE: + break; + case EEH_OPT_THAW_MMIO: + case EEH_OPT_THAW_DMA: + case EEH_OPT_FREEZE_PE: + if (!eeh_ops || !eeh_ops->set_option) { + ret = -ENOENT; + break; + } + + ret = eeh_pci_enable(pe, option); + break; + default: + pr_debug("%s: Option %d out of range (%d, %d)\n", + __func__, option, EEH_OPT_DISABLE, EEH_OPT_THAW_DMA); + ret = -EINVAL; + } + + return ret; +} +EXPORT_SYMBOL_GPL(eeh_pe_set_option); + +/** + * eeh_pe_get_state - Retrieve PE's state + * @pe: EEH PE + * + * Retrieve the PE's state, which includes 3 aspects: enabled + * DMA, enabled IO and asserted reset. + */ +int eeh_pe_get_state(struct eeh_pe *pe) +{ + int result, ret = 0; + bool rst_active, dma_en, mmio_en; + + /* Existing PE ? */ + if (!pe) + return -ENODEV; + + if (!eeh_ops || !eeh_ops->get_state) + return -ENOENT; + + /* + * If the parent PE is owned by the host kernel and is undergoing + * error recovery, we should return the PE state as temporarily + * unavailable so that the error recovery on the guest is suspended + * until the recovery completes on the host. + */ + if (pe->parent && + !(pe->state & EEH_PE_REMOVED) && + (pe->parent->state & (EEH_PE_ISOLATED | EEH_PE_RECOVERING))) + return EEH_PE_STATE_UNAVAIL; + + result = eeh_ops->get_state(pe, NULL); + rst_active = !!(result & EEH_STATE_RESET_ACTIVE); + dma_en = !!(result & EEH_STATE_DMA_ENABLED); + mmio_en = !!(result & EEH_STATE_MMIO_ENABLED); + + if (rst_active) + ret = EEH_PE_STATE_RESET; + else if (dma_en && mmio_en) + ret = EEH_PE_STATE_NORMAL; + else if (!dma_en && !mmio_en) + ret = EEH_PE_STATE_STOPPED_IO_DMA; + else if (!dma_en && mmio_en) + ret = EEH_PE_STATE_STOPPED_DMA; + else + ret = EEH_PE_STATE_UNAVAIL; + + return ret; +} +EXPORT_SYMBOL_GPL(eeh_pe_get_state); + +static int eeh_pe_reenable_devices(struct eeh_pe *pe, bool include_passed) +{ + struct eeh_dev *edev, *tmp; + struct pci_dev *pdev; + int ret = 0; + + eeh_pe_restore_bars(pe); + + /* + * Reenable PCI devices as the devices passed + * through are always enabled before the reset. + */ + eeh_pe_for_each_dev(pe, edev, tmp) { + pdev = eeh_dev_to_pci_dev(edev); + if (!pdev) + continue; + + ret = pci_reenable_device(pdev); + if (ret) { + pr_warn("%s: Failure %d reenabling %s\n", + __func__, ret, pci_name(pdev)); + return ret; + } + } + + /* The PE is still in frozen state */ + if (include_passed || !eeh_pe_passed(pe)) { + ret = eeh_unfreeze_pe(pe); + } else + pr_info("EEH: Note: Leaving passthrough PHB#%x-PE#%x frozen.\n", + pe->phb->global_number, pe->addr); + if (!ret) + eeh_pe_state_clear(pe, EEH_PE_ISOLATED, include_passed); + return ret; +} + + +/** + * eeh_pe_reset - Issue PE reset according to specified type + * @pe: EEH PE + * @option: reset type + * @include_passed: include passed-through devices? + * + * The routine is called to reset the specified PE with the + * indicated type, either fundamental reset or hot reset. + * PE reset is the most important part for error recovery. + */ +int eeh_pe_reset(struct eeh_pe *pe, int option, bool include_passed) +{ + int ret = 0; + + /* Invalid PE ? */ + if (!pe) + return -ENODEV; + + if (!eeh_ops || !eeh_ops->set_option || !eeh_ops->reset) + return -ENOENT; + + switch (option) { + case EEH_RESET_DEACTIVATE: + ret = eeh_ops->reset(pe, option); + eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED, include_passed); + if (ret) + break; + + ret = eeh_pe_reenable_devices(pe, include_passed); + break; + case EEH_RESET_HOT: + case EEH_RESET_FUNDAMENTAL: + /* + * Proactively freeze the PE to drop all MMIO access + * during reset, which should be banned as it's always + * cause recursive EEH error. + */ + eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE); + + eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED); + ret = eeh_ops->reset(pe, option); + break; + default: + pr_debug("%s: Unsupported option %d\n", + __func__, option); + ret = -EINVAL; + } + + return ret; +} +EXPORT_SYMBOL_GPL(eeh_pe_reset); + +/** + * eeh_pe_configure - Configure PCI bridges after PE reset + * @pe: EEH PE + * + * The routine is called to restore the PCI config space for + * those PCI devices, especially PCI bridges affected by PE + * reset issued previously. + */ +int eeh_pe_configure(struct eeh_pe *pe) +{ + int ret = 0; + + /* Invalid PE ? */ + if (!pe) + return -ENODEV; + + return ret; +} +EXPORT_SYMBOL_GPL(eeh_pe_configure); + +/** + * eeh_pe_inject_err - Injecting the specified PCI error to the indicated PE + * @pe: the indicated PE + * @type: error type + * @func: error function + * @addr: address + * @mask: address mask + * + * The routine is called to inject the specified PCI error, which + * is determined by @type and @func, to the indicated PE for + * testing purpose. + */ +int eeh_pe_inject_err(struct eeh_pe *pe, int type, int func, + unsigned long addr, unsigned long mask) +{ + /* Invalid PE ? */ + if (!pe) + return -ENODEV; + + /* Unsupported operation ? */ + if (!eeh_ops || !eeh_ops->err_inject) + return -ENOENT; + + /* Check on PCI error type */ + if (type != EEH_ERR_TYPE_32 && type != EEH_ERR_TYPE_64) + return -EINVAL; + + /* Check on PCI error function */ + if (func < EEH_ERR_FUNC_MIN || func > EEH_ERR_FUNC_MAX) + return -EINVAL; + + return eeh_ops->err_inject(pe, type, func, addr, mask); +} +EXPORT_SYMBOL_GPL(eeh_pe_inject_err); + +#ifdef CONFIG_PROC_FS +static int proc_eeh_show(struct seq_file *m, void *v) +{ + if (!eeh_enabled()) { + seq_printf(m, "EEH Subsystem is globally disabled\n"); + seq_printf(m, "eeh_total_mmio_ffs=%llu\n", eeh_stats.total_mmio_ffs); + } else { + seq_printf(m, "EEH Subsystem is enabled\n"); + seq_printf(m, + "no device=%llu\n" + "no device node=%llu\n" + "no config address=%llu\n" + "check not wanted=%llu\n" + "eeh_total_mmio_ffs=%llu\n" + "eeh_false_positives=%llu\n" + "eeh_slot_resets=%llu\n", + eeh_stats.no_device, + eeh_stats.no_dn, + eeh_stats.no_cfg_addr, + eeh_stats.ignored_check, + eeh_stats.total_mmio_ffs, + eeh_stats.false_positives, + eeh_stats.slot_resets); + } + + return 0; +} +#endif /* CONFIG_PROC_FS */ + +#ifdef CONFIG_DEBUG_FS + + +static struct pci_dev *eeh_debug_lookup_pdev(struct file *filp, + const char __user *user_buf, + size_t count, loff_t *ppos) +{ + uint32_t domain, bus, dev, fn; + struct pci_dev *pdev; + char buf[20]; + int ret; + + memset(buf, 0, sizeof(buf)); + ret = simple_write_to_buffer(buf, sizeof(buf)-1, ppos, user_buf, count); + if (!ret) + return ERR_PTR(-EFAULT); + + ret = sscanf(buf, "%x:%x:%x.%x", &domain, &bus, &dev, &fn); + if (ret != 4) { + pr_err("%s: expected 4 args, got %d\n", __func__, ret); + return ERR_PTR(-EINVAL); + } + + pdev = pci_get_domain_bus_and_slot(domain, bus, (dev << 3) | fn); + if (!pdev) + return ERR_PTR(-ENODEV); + + return pdev; +} + +static int eeh_enable_dbgfs_set(void *data, u64 val) +{ + if (val) + eeh_clear_flag(EEH_FORCE_DISABLED); + else + eeh_add_flag(EEH_FORCE_DISABLED); + + return 0; +} + +static int eeh_enable_dbgfs_get(void *data, u64 *val) +{ + if (eeh_enabled()) + *val = 0x1ul; + else + *val = 0x0ul; + return 0; +} + +DEFINE_DEBUGFS_ATTRIBUTE(eeh_enable_dbgfs_ops, eeh_enable_dbgfs_get, + eeh_enable_dbgfs_set, "0x%llx\n"); + +static ssize_t eeh_force_recover_write(struct file *filp, + const char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct pci_controller *hose; + uint32_t phbid, pe_no; + struct eeh_pe *pe; + char buf[20]; + int ret; + + ret = simple_write_to_buffer(buf, sizeof(buf), ppos, user_buf, count); + if (!ret) + return -EFAULT; + + /* + * When PE is NULL the event is a "special" event. Rather than + * recovering a specific PE it forces the EEH core to scan for failed + * PHBs and recovers each. This needs to be done before any device + * recoveries can occur. + */ + if (!strncmp(buf, "hwcheck", 7)) { + __eeh_send_failure_event(NULL); + return count; + } + + ret = sscanf(buf, "%x:%x", &phbid, &pe_no); + if (ret != 2) + return -EINVAL; + + hose = pci_find_controller_for_domain(phbid); + if (!hose) + return -ENODEV; + + /* Retrieve PE */ + pe = eeh_pe_get(hose, pe_no); + if (!pe) + return -ENODEV; + + /* + * We don't do any state checking here since the detection + * process is async to the recovery process. The recovery + * thread *should* not break even if we schedule a recovery + * from an odd state (e.g. PE removed, or recovery of a + * non-isolated PE) + */ + __eeh_send_failure_event(pe); + + return ret < 0 ? ret : count; +} + +static const struct file_operations eeh_force_recover_fops = { + .open = simple_open, + .llseek = no_llseek, + .write = eeh_force_recover_write, +}; + +static ssize_t eeh_debugfs_dev_usage(struct file *filp, + char __user *user_buf, + size_t count, loff_t *ppos) +{ + static const char usage[] = "input format: <domain>:<bus>:<dev>.<fn>\n"; + + return simple_read_from_buffer(user_buf, count, ppos, + usage, sizeof(usage) - 1); +} + +static ssize_t eeh_dev_check_write(struct file *filp, + const char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct pci_dev *pdev; + struct eeh_dev *edev; + int ret; + + pdev = eeh_debug_lookup_pdev(filp, user_buf, count, ppos); + if (IS_ERR(pdev)) + return PTR_ERR(pdev); + + edev = pci_dev_to_eeh_dev(pdev); + if (!edev) { + pci_err(pdev, "No eeh_dev for this device!\n"); + pci_dev_put(pdev); + return -ENODEV; + } + + ret = eeh_dev_check_failure(edev); + pci_info(pdev, "eeh_dev_check_failure(%s) = %d\n", + pci_name(pdev), ret); + + pci_dev_put(pdev); + + return count; +} + +static const struct file_operations eeh_dev_check_fops = { + .open = simple_open, + .llseek = no_llseek, + .write = eeh_dev_check_write, + .read = eeh_debugfs_dev_usage, +}; + +static int eeh_debugfs_break_device(struct pci_dev *pdev) +{ + struct resource *bar = NULL; + void __iomem *mapped; + u16 old, bit; + int i, pos; + + /* Do we have an MMIO BAR to disable? */ + for (i = 0; i <= PCI_STD_RESOURCE_END; i++) { + struct resource *r = &pdev->resource[i]; + + if (!r->flags || !r->start) + continue; + if (r->flags & IORESOURCE_IO) + continue; + if (r->flags & IORESOURCE_UNSET) + continue; + + bar = r; + break; + } + + if (!bar) { + pci_err(pdev, "Unable to find Memory BAR to cause EEH with\n"); + return -ENXIO; + } + + pci_err(pdev, "Going to break: %pR\n", bar); + + if (pdev->is_virtfn) { +#ifndef CONFIG_PCI_IOV + return -ENXIO; +#else + /* + * VFs don't have a per-function COMMAND register, so the best + * we can do is clear the Memory Space Enable bit in the PF's + * SRIOV control reg. + * + * Unfortunately, this requires that we have a PF (i.e doesn't + * work for a passed-through VF) and it has the potential side + * effect of also causing an EEH on every other VF under the + * PF. Oh well. + */ + pdev = pdev->physfn; + if (!pdev) + return -ENXIO; /* passed through VFs have no PF */ + + pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_SRIOV); + pos += PCI_SRIOV_CTRL; + bit = PCI_SRIOV_CTRL_MSE; +#endif /* !CONFIG_PCI_IOV */ + } else { + bit = PCI_COMMAND_MEMORY; + pos = PCI_COMMAND; + } + + /* + * Process here is: + * + * 1. Disable Memory space. + * + * 2. Perform an MMIO to the device. This should result in an error + * (CA / UR) being raised by the device which results in an EEH + * PE freeze. Using the in_8() accessor skips the eeh detection hook + * so the freeze hook so the EEH Detection machinery won't be + * triggered here. This is to match the usual behaviour of EEH + * where the HW will asynchronously freeze a PE and it's up to + * the kernel to notice and deal with it. + * + * 3. Turn Memory space back on. This is more important for VFs + * since recovery will probably fail if we don't. For normal + * the COMMAND register is reset as a part of re-initialising + * the device. + * + * Breaking stuff is the point so who cares if it's racy ;) + */ + pci_read_config_word(pdev, pos, &old); + + mapped = ioremap(bar->start, PAGE_SIZE); + if (!mapped) { + pci_err(pdev, "Unable to map MMIO BAR %pR\n", bar); + return -ENXIO; + } + + pci_write_config_word(pdev, pos, old & ~bit); + in_8(mapped); + pci_write_config_word(pdev, pos, old); + + iounmap(mapped); + + return 0; +} + +static ssize_t eeh_dev_break_write(struct file *filp, + const char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct pci_dev *pdev; + int ret; + + pdev = eeh_debug_lookup_pdev(filp, user_buf, count, ppos); + if (IS_ERR(pdev)) + return PTR_ERR(pdev); + + ret = eeh_debugfs_break_device(pdev); + pci_dev_put(pdev); + + if (ret < 0) + return ret; + + return count; +} + +static const struct file_operations eeh_dev_break_fops = { + .open = simple_open, + .llseek = no_llseek, + .write = eeh_dev_break_write, + .read = eeh_debugfs_dev_usage, +}; + +static ssize_t eeh_dev_can_recover(struct file *filp, + const char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct pci_driver *drv; + struct pci_dev *pdev; + size_t ret; + + pdev = eeh_debug_lookup_pdev(filp, user_buf, count, ppos); + if (IS_ERR(pdev)) + return PTR_ERR(pdev); + + /* + * In order for error recovery to work the driver needs to implement + * .error_detected(), so it can quiesce IO to the device, and + * .slot_reset() so it can re-initialise the device after a reset. + * + * Ideally they'd implement .resume() too, but some drivers which + * we need to support (notably IPR) don't so I guess we can tolerate + * that. + * + * .mmio_enabled() is mostly there as a work-around for devices which + * take forever to re-init after a hot reset. Implementing that is + * strictly optional. + */ + drv = pci_dev_driver(pdev); + if (drv && + drv->err_handler && + drv->err_handler->error_detected && + drv->err_handler->slot_reset) { + ret = count; + } else { + ret = -EOPNOTSUPP; + } + + pci_dev_put(pdev); + + return ret; +} + +static const struct file_operations eeh_dev_can_recover_fops = { + .open = simple_open, + .llseek = no_llseek, + .write = eeh_dev_can_recover, + .read = eeh_debugfs_dev_usage, +}; + +#endif + +static int __init eeh_init_proc(void) +{ + if (machine_is(pseries) || machine_is(powernv)) { + proc_create_single("powerpc/eeh", 0, NULL, proc_eeh_show); +#ifdef CONFIG_DEBUG_FS + debugfs_create_file_unsafe("eeh_enable", 0600, + arch_debugfs_dir, NULL, + &eeh_enable_dbgfs_ops); + debugfs_create_u32("eeh_max_freezes", 0600, + arch_debugfs_dir, &eeh_max_freezes); + debugfs_create_bool("eeh_disable_recovery", 0600, + arch_debugfs_dir, + &eeh_debugfs_no_recover); + debugfs_create_file_unsafe("eeh_dev_check", 0600, + arch_debugfs_dir, NULL, + &eeh_dev_check_fops); + debugfs_create_file_unsafe("eeh_dev_break", 0600, + arch_debugfs_dir, NULL, + &eeh_dev_break_fops); + debugfs_create_file_unsafe("eeh_force_recover", 0600, + arch_debugfs_dir, NULL, + &eeh_force_recover_fops); + debugfs_create_file_unsafe("eeh_dev_can_recover", 0600, + arch_debugfs_dir, NULL, + &eeh_dev_can_recover_fops); + eeh_cache_debugfs_init(); +#endif + } + + return 0; +} +__initcall(eeh_init_proc); |