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Diffstat (limited to 'arch/powerpc/kernel/eeh.c')
| -rw-r--r-- | arch/powerpc/kernel/eeh.c | 1747 |
1 files changed, 1747 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c new file mode 100644 index 000000000..9ee61d156 --- /dev/null +++ b/arch/powerpc/kernel/eeh.c @@ -0,0 +1,1747 @@ +/* + * 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/debugfs.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/atomic.h> +#include <asm/debug.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> + + +/** Overview: + * EEH, or "Extended Error Handling" is a PCI bridge technology for + * dealing with PCI bus errors that can't be dealt with within the + * usual PCI framework, except by check-stopping the CPU. Systems + * that are designed for high-availability/reliability cannot afford + * to crash due to a "mere" PCI error, thus the need for EEH. + * An EEH-capable bridge operates by converting a detected error + * into a "slot freeze", taking the PCI adapter off-line, making + * the slot behave, from the OS'es point of view, as if the slot + * were "empty": all reads return 0xff's and all writes are silently + * ignored. EEH slot isolation events can be triggered by parity + * errors on the address or data busses (e.g. during posted writes), + * which in turn might be caused by low voltage on the bus, dust, + * vibration, humidity, radioactivity or plain-old failed hardware. + * + * Note, however, that one of the leading causes of EEH slot + * freeze events are buggy device drivers, buggy device microcode, + * or buggy device hardware. This is because any attempt by the + * device to bus-master data to a memory address that is not + * assigned to the device will trigger a slot freeze. (The idea + * is to prevent devices-gone-wild from corrupting system memory). + * Buggy hardware/drivers will have a miserable time co-existing + * with EEH. + * + * Ideally, a PCI device driver, when suspecting that an isolation + * event has occurred (e.g. by reading 0xff's), will then ask EEH + * whether this is the case, and then take appropriate steps to + * reset the PCI slot, the PCI device, and then resume operations. + * However, until that day, the checking is done here, with the + * eeh_check_failure() routine embedded in the MMIO macros. If + * the slot is found to be isolated, an "EEH Event" is synthesized + * and sent out for processing. + */ + +/* If a device driver keeps reading an MMIO register in an interrupt + * handler after a slot isolation event, it might be broken. + * This sets the threshold for how many read attempts we allow + * before printing an error message. + */ +#define EEH_MAX_FAILS 2100000 + +/* Time to wait for a PCI slot to report status, in milliseconds */ +#define PCI_BUS_RESET_WAIT_MSEC (5*60*1000) + +/* + * EEH probe mode support, which is part of the flags, + * is to support multiple platforms for EEH. Some platforms + * like pSeries do PCI emunation based on device tree. + * However, other platforms like powernv probe PCI devices + * from hardware. The flag is used to distinguish that. + * In addition, struct eeh_ops::probe would be invoked for + * particular OF node or PCI device so that the corresponding + * PE would be created there. + */ +int eeh_subsystem_flags; +EXPORT_SYMBOL(eeh_subsystem_flags); + +/* + * 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. + */ +int eeh_max_freezes = 5; + +/* Platform dependent EEH operations */ +struct eeh_ops *eeh_ops = NULL; + +/* Lock to avoid races due to multiple reports of an error */ +DEFINE_RAW_SPINLOCK(confirm_error_lock); + +/* Lock to protect passed flags */ +static DEFINE_MUTEX(eeh_dev_mutex); + +/* Buffer for reporting pci register dumps. Its here in BSS, and + * not dynamically alloced, so that it ends up in RMO where RTAS + * can access it. + */ +#define EEH_PCI_REGS_LOG_LEN 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; + +#define IS_BRIDGE(class_code) (((class_code)<<16) == PCI_BASE_CLASS_BRIDGE) + +static int __init eeh_setup(char *str) +{ + if (!strcmp(str, "off")) + eeh_add_flag(EEH_FORCE_DISABLED); + else if (!strcmp(str, "early_log")) + eeh_add_flag(EEH_EARLY_DUMP_LOG); + + return 1; +} +__setup("eeh=", eeh_setup); + +/* + * 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) +{ + struct pci_dn *pdn = eeh_dev_to_pdn(edev); + 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->phb->global_number, pdn->busno, + PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn)); + pr_warn("EEH: of node=%04x:%02x:%02x:%01x\n", + edev->phb->global_number, pdn->busno, + PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn)); + + eeh_ops->read_config(pdn, 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(pdn, 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(pdn, 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(pdn, 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(pdn, 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(pdn, 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(pdn, 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(pdn, 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(void *data, void *flag) +{ + struct eeh_pe *pe = data; + struct eeh_dev *edev, *tmp; + size_t *plen = flag; + + /* If the PE's config space is blocked, 0xFF's will be + * returned. It's pointless to collect the log in this + * case. + */ + if (pe->state & EEH_PE_CFG_BLOCKED) + return NULL; + + 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. + */ + if (!(pe->type & EEH_PE_PHB)) { + if (eeh_has_flag(EEH_ENABLE_IO_FOR_LOG)) + eeh_pci_enable(pe, EEH_OPT_THAW_MMIO); + eeh_ops->configure_bridge(pe); + eeh_pe_restore_bars(pe); + + pci_regs_buf[0] = 0; + eeh_pe_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) +{ + pte_t *ptep; + unsigned long pa; + int hugepage_shift; + + /* + * We won't find hugepages here(this is iomem). Hence we are not + * worried about _PAGE_SPLITTING/collapse. Also we will not hit + * page table free, because of init_mm. + */ + ptep = __find_linux_pte_or_hugepte(init_mm.pgd, token, &hugepage_shift); + if (!ptep) + return token; + WARN_ON(hugepage_shift); + pa = pte_pfn(*ptep) << PAGE_SHIFT; + + return pa | (token & (PAGE_SIZE-1)); +} + +/* + * On PowerNV platform, we might already have fenced PHB there. + * For that case, it's meaningless to recover frozen PE. Intead, + * We have to handle fenced PHB firstly. + */ +static int eeh_phb_check_failure(struct eeh_pe *pe) +{ + struct eeh_pe *phb_pe; + unsigned long flags; + int ret; + + if (!eeh_has_flag(EEH_PROBE_MODE_DEV)) + return -EPERM; + + /* Find the PHB PE */ + phb_pe = eeh_phb_pe_get(pe->phb); + if (!phb_pe) { + pr_warn("%s Can't find PE for PHB#%d\n", + __func__, pe->phb->global_number); + return -EEXIST; + } + + /* If the PHB has been in problematic state */ + eeh_serialize_lock(&flags); + if (phb_pe->state & EEH_PE_ISOLATED) { + ret = 0; + goto out; + } + + /* Check PHB state */ + ret = eeh_ops->get_state(phb_pe, NULL); + if ((ret < 0) || + (ret == EEH_STATE_NOT_SUPPORT) || + (ret & (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) == + (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) { + ret = 0; + goto out; + } + + /* Isolate the PHB and send event */ + eeh_pe_state_mark(phb_pe, EEH_PE_ISOLATED); + eeh_serialize_unlock(flags); + + pr_err("EEH: PHB#%x failure detected, location: %s\n", + phb_pe->phb->global_number, eeh_pe_loc_get(phb_pe)); + dump_stack(); + eeh_send_failure_event(phb_pe); + + return 1; +out: + eeh_serialize_unlock(flags); + return ret; +} + +/** + * eeh_dev_check_failure - Check if all 1's data is due to EEH slot freeze + * @edev: eeh device + * + * Check for an EEH failure for the given device node. Call this + * routine if the result of a read was all 0xff's and you want to + * find out if this is due to an EEH slot freeze. This routine + * will query firmware for the EEH status. + * + * Returns 0 if there has not been an EEH error; otherwise returns + * a non-zero value and queues up a slot isolation event notification. + * + * It is safe to call this routine in an interrupt context. + */ +int eeh_dev_check_failure(struct eeh_dev *edev) +{ + int ret; + int active_flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE); + unsigned long flags; + struct pci_dn *pdn; + struct pci_dev *dev; + struct eeh_pe *pe, *parent_pe, *phb_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++; + pr_debug("EEH: Ignored check for %s\n", + eeh_pci_name(dev)); + return 0; + } + + if (!pe->addr && !pe->config_addr) { + eeh_stats.no_cfg_addr++; + return 0; + } + + /* + * On PowerNV platform, we might already have fenced PHB + * there and we need take care of that firstly. + */ + ret = eeh_phb_check_failure(pe); + if (ret > 0) + return ret; + + /* + * If the PE isn't owned by us, we shouldn't check the + * state. Instead, let the owner handle it if the PE has + * been frozen. + */ + if (eeh_pe_passed(pe)) + return 0; + + /* If we already have a pending isolation event for this + * slot, we know it's bad already, we don't need to check. + * Do this checking under a lock; as multiple PCI devices + * in one slot might report errors simultaneously, and we + * only want one error recovery routine running. + */ + eeh_serialize_lock(&flags); + rc = 1; + if (pe->state & EEH_PE_ISOLATED) { + pe->check_count++; + if (pe->check_count % EEH_MAX_FAILS == 0) { + pdn = eeh_dev_to_pdn(edev); + if (pdn->node) + location = of_get_property(pdn->node, "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 ? location : "unknown", + eeh_driver_name(dev), eeh_pci_name(dev)); + printk(KERN_ERR "EEH: Might be infinite loop in %s driver\n", + eeh_driver_name(dev)); + dump_stack(); + } + goto dn_unlock; + } + + /* + * Now test for an EEH failure. This is VERY expensive. + * Note that the eeh_config_addr may be a parent device + * in the case of a device behind a bridge, or it may be + * function zero of a multi-function device. + * In any case they must share a common PHB. + */ + ret = eeh_ops->get_state(pe, NULL); + + /* Note that config-io to empty slots may fail; + * they are empty when they don't have children. + * We will punt with the following conditions: Failure to get + * PE's state, EEH not support and Permanently unavailable + * state, PE is in good state. + */ + if ((ret < 0) || + (ret == EEH_STATE_NOT_SUPPORT) || + ((ret & active_flags) == active_flags)) { + eeh_stats.false_positives++; + pe->false_positives++; + rc = 0; + goto dn_unlock; + } + + /* + * It should be corner case that the parent PE has been + * put into frozen state as well. We should take care + * that at first. + */ + parent_pe = pe->parent; + while (parent_pe) { + /* Hit the ceiling ? */ + if (parent_pe->type & EEH_PE_PHB) + break; + + /* Frozen parent PE ? */ + ret = eeh_ops->get_state(parent_pe, NULL); + if (ret > 0 && + (ret & active_flags) != active_flags) + pe = parent_pe; + + /* Next parent level */ + parent_pe = parent_pe->parent; + } + + eeh_stats.slot_resets++; + + /* Avoid repeated reports of this failure, including problems + * with other functions on this device, and functions under + * bridges. + */ + eeh_pe_state_mark(pe, EEH_PE_ISOLATED); + eeh_serialize_unlock(flags); + + /* Most EEH events are due to device driver bugs. Having + * a stack trace will help the device-driver authors figure + * out what happened. So print that out. + */ + phb_pe = eeh_phb_pe_get(pe->phb); + pr_err("EEH: Frozen PHB#%x-PE#%x detected\n", + pe->phb->global_number, pe->addr); + pr_err("EEH: PE location: %s, PHB location: %s\n", + eeh_pe_loc_get(pe), eeh_pe_loc_get(phb_pe)); + dump_stack(); + + eeh_send_failure_event(pe); + + return 1; + +dn_unlock: + eeh_serialize_unlock(flags); + return rc; +} + +EXPORT_SYMBOL_GPL(eeh_dev_check_failure); + +/** + * eeh_check_failure - Check if all 1's data is due to EEH slot freeze + * @token: I/O address + * + * Check for an EEH failure at the given I/O address. Call this + * routine if the result of a read was all 0xff's and you want to + * find out if this is due to an EEH slot freeze event. This routine + * will query firmware for the EEH status. + * + * Note this routine is safe to call in an interrupt context. + */ +int eeh_check_failure(const volatile void __iomem *token) +{ + unsigned long addr; + struct eeh_dev *edev; + + /* Finding the phys addr + pci device; this is pretty quick. */ + addr = eeh_token_to_phys((unsigned long __force) token); + edev = eeh_addr_cache_get_dev(addr); + if (!edev) { + eeh_stats.no_device++; + return 0; + } + + return eeh_dev_check_failure(edev); +} +EXPORT_SYMBOL(eeh_check_failure); + + +/** + * eeh_pci_enable - Enable MMIO or DMA transfers for this slot + * @pe: EEH PE + * + * This routine should be called to reenable frozen MMIO or DMA + * so that it would work correctly again. It's useful while doing + * recovery or log collection on the indicated device. + */ +int eeh_pci_enable(struct eeh_pe *pe, int function) +{ + int active_flag, rc; + + /* + * pHyp doesn't allow to enable IO or DMA on unfrozen PE. + * Also, it's pointless to enable them on unfrozen PE. So + * we have to check before enabling IO or DMA. + */ + switch (function) { + case EEH_OPT_THAW_MMIO: + active_flag = EEH_STATE_MMIO_ACTIVE; + break; + case EEH_OPT_THAW_DMA: + active_flag = EEH_STATE_DMA_ACTIVE; + break; + case EEH_OPT_DISABLE: + case EEH_OPT_ENABLE: + case EEH_OPT_FREEZE_PE: + active_flag = 0; + break; + default: + pr_warn("%s: Invalid function %d\n", + __func__, function); + return -EINVAL; + } + + /* + * Check if IO or DMA has been enabled before + * enabling them. + */ + if (active_flag) { + rc = eeh_ops->get_state(pe, NULL); + if (rc < 0) + return rc; + + /* Needn't enable it at all */ + if (rc == EEH_STATE_NOT_SUPPORT) + return 0; + + /* It's already enabled */ + if (rc & active_flag) + return 0; + } + + + /* Issue the request */ + rc = eeh_ops->set_option(pe, function); + if (rc) + pr_warn("%s: Unexpected state change %d on " + "PHB#%d-PE#%x, err=%d\n", + __func__, function, pe->phb->global_number, + pe->addr, rc); + + /* Check if the request is finished successfully */ + if (active_flag) { + rc = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); + if (rc <= 0) + return rc; + + if (rc & active_flag) + return 0; + + return -EIO; + } + + return rc; +} + +static void *eeh_disable_and_save_dev_state(void *data, void *userdata) +{ + struct eeh_dev *edev = data; + 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 NULL; + + /* 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); + + return NULL; +} + +static void *eeh_restore_dev_state(void *data, void *userdata) +{ + struct eeh_dev *edev = data; + struct pci_dn *pdn = eeh_dev_to_pdn(edev); + struct pci_dev *pdev = eeh_dev_to_pci_dev(edev); + struct pci_dev *dev = userdata; + + if (!pdev) + return NULL; + + /* Apply customization from firmware */ + if (pdn && eeh_ops->restore_config) + eeh_ops->restore_config(pdn); + + /* The caller should restore state for the specified device */ + if (pdev != dev) + pci_save_state(pdev); + + return NULL; +} + +/** + * pcibios_set_pcie_slot_reset - Set PCI-E reset state + * @dev: pci device struct + * @state: reset state to enter + * + * Return value: + * 0 if success + */ +int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) +{ + struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); + struct eeh_pe *pe = eeh_dev_to_pe(edev); + + if (!pe) { + pr_err("%s: No PE found on PCI device %s\n", + __func__, pci_name(dev)); + return -EINVAL; + } + + switch (state) { + case pcie_deassert_reset: + eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); + eeh_unfreeze_pe(pe, false); + eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED); + eeh_pe_dev_traverse(pe, eeh_restore_dev_state, dev); + eeh_pe_state_clear(pe, EEH_PE_ISOLATED); + break; + case pcie_hot_reset: + eeh_pe_state_mark(pe, EEH_PE_ISOLATED); + eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE); + eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev); + eeh_pe_state_mark(pe, EEH_PE_CFG_BLOCKED); + eeh_ops->reset(pe, EEH_RESET_HOT); + break; + case pcie_warm_reset: + eeh_pe_state_mark(pe, EEH_PE_ISOLATED); + eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE); + eeh_pe_dev_traverse(pe, eeh_disable_and_save_dev_state, dev); + 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); + return -EINVAL; + }; + + return 0; +} + +/** + * eeh_set_pe_freset - Check the required reset for the indicated device + * @data: EEH device + * @flag: return value + * + * Each device might have its preferred reset type: fundamental or + * hot reset. The routine is used to collected the information for + * the indicated device and its children so that the bunch of the + * devices could be reset properly. + */ +static void *eeh_set_dev_freset(void *data, void *flag) +{ + struct pci_dev *dev; + unsigned int *freset = (unsigned int *)flag; + struct eeh_dev *edev = (struct eeh_dev *)data; + + dev = eeh_dev_to_pci_dev(edev); + if (dev) + *freset |= dev->needs_freset; + + return NULL; +} + +/** + * eeh_reset_pe_once - Assert the pci #RST line for 1/4 second + * @pe: EEH PE + * + * Assert the PCI #RST line for 1/4 second. + */ +static void eeh_reset_pe_once(struct eeh_pe *pe) +{ + unsigned int freset = 0; + + /* Determine type of EEH reset required for + * Partitionable Endpoint, a hot-reset (1) + * or a fundamental reset (3). + * A fundamental reset required by any device under + * Partitionable Endpoint trumps hot-reset. + */ + eeh_pe_dev_traverse(pe, eeh_set_dev_freset, &freset); + + if (freset) + eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL); + else + eeh_ops->reset(pe, EEH_RESET_HOT); + + eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); +} + +/** + * eeh_reset_pe - Reset the indicated PE + * @pe: EEH PE + * + * This routine should be called to reset indicated device, including + * PE. A PE might include multiple PCI devices and sometimes PCI bridges + * might be involved as well. + */ +int eeh_reset_pe(struct eeh_pe *pe) +{ + int flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE); + int i, state, ret; + + /* Mark as reset and block config space */ + eeh_pe_state_mark(pe, EEH_PE_RESET | EEH_PE_CFG_BLOCKED); + + /* Take three shots at resetting the bus */ + for (i = 0; i < 3; i++) { + eeh_reset_pe_once(pe); + + /* + * EEH_PE_ISOLATED is expected to be removed after + * BAR restore. + */ + state = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); + if ((state & flags) == flags) { + ret = 0; + goto out; + } + + if (state < 0) { + pr_warn("%s: Unrecoverable slot failure on PHB#%d-PE#%x", + __func__, pe->phb->global_number, pe->addr); + ret = -ENOTRECOVERABLE; + goto out; + } + + /* We might run out of credits */ + ret = -EIO; + pr_warn("%s: Failure %d resetting PHB#%x-PE#%x\n (%d)\n", + __func__, state, pe->phb->global_number, pe->addr, (i + 1)); + } + +out: + eeh_pe_state_clear(pe, EEH_PE_RESET | EEH_PE_CFG_BLOCKED); + 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) +{ + struct pci_dn *pdn; + int i; + + pdn = eeh_dev_to_pdn(edev); + if (!pdn) + return; + + for (i = 0; i < 16; i++) + eeh_ops->read_config(pdn, i * 4, 4, &edev->config_space[i]); + + /* + * For PCI bridges including root port, we need enable bus + * master explicitly. Otherwise, it can't fetch IODA table + * entries correctly. So we cache the bit in advance so that + * we can restore it after reset, either PHB range or PE range. + */ + if (edev->mode & EEH_DEV_BRIDGE) + edev->config_space[1] |= PCI_COMMAND_MASTER; +} + +/** + * eeh_ops_register - Register platform dependent EEH operations + * @ops: platform dependent EEH operations + * + * Register the platform dependent EEH operation callback + * functions. The platform should call this function before + * any other EEH operations. + */ +int __init eeh_ops_register(struct eeh_ops *ops) +{ + if (!ops->name) { + pr_warn("%s: Invalid EEH ops name for %p\n", + __func__, ops); + return -EINVAL; + } + + if (eeh_ops && eeh_ops != ops) { + pr_warn("%s: EEH ops of platform %s already existing (%s)\n", + __func__, eeh_ops->name, ops->name); + return -EEXIST; + } + + eeh_ops = ops; + + return 0; +} + +/** + * eeh_ops_unregister - Unreigster platform dependent EEH operations + * @name: name of EEH platform operations + * + * Unregister the platform dependent EEH operation callback + * functions. + */ +int __exit eeh_ops_unregister(const char *name) +{ + if (!name || !strlen(name)) { + pr_warn("%s: Invalid EEH ops name\n", + __func__); + return -EINVAL; + } + + if (eeh_ops && !strcmp(eeh_ops->name, name)) { + eeh_ops = NULL; + return 0; + } + + return -EEXIST; +} + +static int eeh_reboot_notifier(struct notifier_block *nb, + unsigned long action, void *unused) +{ + eeh_clear_flag(EEH_ENABLED); + return NOTIFY_DONE; +} + +static struct notifier_block eeh_reboot_nb = { + .notifier_call = eeh_reboot_notifier, +}; + +/** + * eeh_init - EEH initialization + * + * Initialize EEH by trying to enable it for all of the adapters in the system. + * As a side effect we can determine here if eeh is supported at all. + * Note that we leave EEH on so failed config cycles won't cause a machine + * check. If a user turns off EEH for a particular adapter they are really + * telling Linux to ignore errors. Some hardware (e.g. POWER5) won't + * grant access to a slot if EEH isn't enabled, and so we always enable + * EEH for all slots/all devices. + * + * The eeh-force-off option disables EEH checking globally, for all slots. + * Even if force-off is set, the EEH hardware is still enabled, so that + * newer systems can boot. + */ +int eeh_init(void) +{ + struct pci_controller *hose, *tmp; + struct pci_dn *pdn; + static int cnt = 0; + int ret = 0; + + /* + * We have to delay the initialization on PowerNV after + * the PCI hierarchy tree has been built because the PEs + * are figured out based on PCI devices instead of device + * tree nodes + */ + if (machine_is(powernv) && cnt++ <= 0) + return ret; + + /* Register reboot notifier */ + ret = register_reboot_notifier(&eeh_reboot_nb); + if (ret) { + pr_warn("%s: Failed to register notifier (%d)\n", + __func__, ret); + return ret; + } + + /* call platform initialization function */ + if (!eeh_ops) { + pr_warn("%s: Platform EEH operation not found\n", + __func__); + return -EEXIST; + } else if ((ret = eeh_ops->init())) + return ret; + + /* Initialize EEH event */ + ret = eeh_event_init(); + if (ret) + return ret; + + /* Enable EEH for all adapters */ + list_for_each_entry_safe(hose, tmp, &hose_list, list_node) { + pdn = hose->pci_data; + traverse_pci_dn(pdn, eeh_ops->probe, NULL); + } + + /* + * Call platform post-initialization. Actually, It's good chance + * to inform platform that EEH is ready to supply service if the + * I/O cache stuff has been built up. + */ + if (eeh_ops->post_init) { + ret = eeh_ops->post_init(); + if (ret) + return ret; + } + + if (eeh_enabled()) + pr_info("EEH: PCI Enhanced I/O Error Handling Enabled\n"); + else + pr_warn("EEH: No capable adapters found\n"); + + return ret; +} + +core_initcall_sync(eeh_init); + +/** + * eeh_add_device_early - Enable EEH for the indicated device node + * @pdn: PCI device node for which to set up EEH + * + * This routine must be used to perform EEH initialization for PCI + * devices that were added after system boot (e.g. hotplug, dlpar). + * This routine must be called before any i/o is performed to the + * adapter (inluding any config-space i/o). + * Whether this actually enables EEH or not for this device depends + * on the CEC architecture, type of the device, on earlier boot + * command-line arguments & etc. + */ +void eeh_add_device_early(struct pci_dn *pdn) +{ + struct pci_controller *phb; + struct eeh_dev *edev = pdn_to_eeh_dev(pdn); + + if (!edev || !eeh_enabled()) + return; + + if (!eeh_has_flag(EEH_PROBE_MODE_DEVTREE)) + return; + + /* USB Bus children of PCI devices will not have BUID's */ + phb = edev->phb; + if (NULL == phb || + (eeh_has_flag(EEH_PROBE_MODE_DEVTREE) && 0 == phb->buid)) + return; + + eeh_ops->probe(pdn, NULL); +} + +/** + * eeh_add_device_tree_early - Enable EEH for the indicated device + * @pdn: PCI 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 pci_dn *pdn) +{ + struct pci_dn *n; + + if (!pdn) + return; + + list_for_each_entry(n, &pdn->child_list, list) + eeh_add_device_tree_early(n); + eeh_add_device_early(pdn); +} +EXPORT_SYMBOL_GPL(eeh_add_device_tree_early); + +/** + * eeh_add_device_late - Perform EEH initialization for the indicated pci device + * @dev: pci device for which to set up EEH + * + * This routine must be used to complete EEH initialization for PCI + * devices that were added after system boot (e.g. hotplug, dlpar). + */ +void eeh_add_device_late(struct pci_dev *dev) +{ + struct pci_dn *pdn; + struct eeh_dev *edev; + + if (!dev || !eeh_enabled()) + return; + + pr_debug("EEH: Adding device %s\n", pci_name(dev)); + + pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn); + edev = pdn_to_eeh_dev(pdn); + if (edev->pdev == dev) { + pr_debug("EEH: Already referenced !\n"); + return; + } + + if (eeh_has_flag(EEH_PROBE_MODE_DEV)) + eeh_ops->probe(pdn, NULL); + + /* + * The EEH cache might not be removed correctly because of + * unbalanced kref to the device during unplug time, which + * relies on pcibios_release_device(). So we have to remove + * that here explicitly. + */ + if (edev->pdev) { + eeh_rmv_from_parent_pe(edev); + eeh_addr_cache_rmv_dev(edev->pdev); + eeh_sysfs_remove_device(edev->pdev); + edev->mode &= ~EEH_DEV_SYSFS; + + /* + * We definitely should have the PCI device removed + * though it wasn't correctly. So we needn't call + * into error handler afterwards. + */ + edev->mode |= EEH_DEV_NO_HANDLER; + + edev->pdev = NULL; + dev->dev.archdata.edev = NULL; + } + + edev->pdev = dev; + dev->dev.archdata.edev = edev; + + eeh_addr_cache_insert_dev(dev); +} + +/** + * eeh_add_device_tree_late - Perform EEH initialization for the indicated PCI bus + * @bus: PCI bus + * + * This routine must be used to perform EEH initialization for PCI + * devices which are attached to the indicated PCI bus. The PCI bus + * is added after system boot through hotplug or dlpar. + */ +void eeh_add_device_tree_late(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + eeh_add_device_late(dev); + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { + struct pci_bus *subbus = dev->subordinate; + if (subbus) + eeh_add_device_tree_late(subbus); + } + } +} +EXPORT_SYMBOL_GPL(eeh_add_device_tree_late); + +/** + * eeh_add_sysfs_files - Add EEH sysfs files for the indicated PCI bus + * @bus: PCI bus + * + * This routine must be used to add EEH sysfs files for PCI + * devices which are attached to the indicated PCI bus. The PCI bus + * is added after system boot through hotplug or dlpar. + */ +void eeh_add_sysfs_files(struct pci_bus *bus) +{ + struct pci_dev *dev; + + list_for_each_entry(dev, &bus->devices, bus_list) { + eeh_sysfs_add_device(dev); + if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { + struct pci_bus *subbus = dev->subordinate; + if (subbus) + eeh_add_sysfs_files(subbus); + } + } +} +EXPORT_SYMBOL_GPL(eeh_add_sysfs_files); + +/** + * eeh_remove_device - Undo EEH setup for the indicated pci device + * @dev: pci device to be removed + * + * This routine should be called when a device is removed from + * a running system (e.g. by hotplug or dlpar). It unregisters + * the PCI device from the EEH subsystem. I/O errors affecting + * this device will no longer be detected after this call; thus, + * i/o errors affecting this slot may leave this device unusable. + */ +void eeh_remove_device(struct pci_dev *dev) +{ + struct eeh_dev *edev; + + if (!dev || !eeh_enabled()) + return; + edev = pci_dev_to_eeh_dev(dev); + + /* Unregister the device with the EEH/PCI address search system */ + pr_debug("EEH: Removing device %s\n", pci_name(dev)); + + if (!edev || !edev->pdev || !edev->pe) { + pr_debug("EEH: Not referenced !\n"); + return; + } + + /* + * During the hotplug for EEH error recovery, we need the EEH + * device attached to the parent PE in order for BAR restore + * a bit later. So we keep it for BAR restore and remove it + * from the parent PE during the BAR resotre. + */ + edev->pdev = NULL; + dev->dev.archdata.edev = NULL; + if (!(edev->pe->state & EEH_PE_KEEP)) + eeh_rmv_from_parent_pe(edev); + else + edev->mode |= EEH_DEV_DISCONNECTED; + + /* + * We're removing from the PCI subsystem, that means + * the PCI device driver can't support EEH or not + * well. So we rely on hotplug completely to do recovery + * for the specific PCI device. + */ + edev->mode |= EEH_DEV_NO_HANDLER; + + eeh_addr_cache_rmv_dev(dev); + eeh_sysfs_remove_device(dev); + edev->mode &= ~EEH_DEV_SYSFS; +} + +int eeh_unfreeze_pe(struct eeh_pe *pe, bool sw_state) +{ + int ret; + + ret = eeh_pci_enable(pe, EEH_OPT_THAW_MMIO); + if (ret) { + pr_warn("%s: Failure %d enabling IO on PHB#%x-PE#%x\n", + __func__, ret, pe->phb->global_number, pe->addr); + return ret; + } + + ret = eeh_pci_enable(pe, EEH_OPT_THAW_DMA); + if (ret) { + pr_warn("%s: Failure %d enabling DMA on PHB#%x-PE#%x\n", + __func__, ret, pe->phb->global_number, pe->addr); + return ret; + } + + /* Clear software isolated state */ + if (sw_state && (pe->state & EEH_PE_ISOLATED)) + eeh_pe_state_clear(pe, EEH_PE_ISOLATED); + + return ret; +} + + +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 flags, ret; + + /* Check PE state */ + flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE); + ret = eeh_ops->get_state(pe, NULL); + if (ret < 0 || ret == EEH_STATE_NOT_SUPPORT) + return 0; + + /* Unfrozen PE, nothing to do */ + if ((ret & flags) == flags) + 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; + + goto reset; + } + } + + return eeh_unfreeze_pe(pe, true); + +reset: + return eeh_pe_reset_and_recover(pe); +} + +/** + * 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 */ + atomic_dec(&edev->pe->pass_dev_cnt); + WARN_ON(atomic_read(&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; + struct iommu_table *tbl; + + if (!dev) + return 0; + + tbl = get_iommu_table_base(dev); + if (tbl && tbl->it_group) { + *ppdev = pdev; + return 1; + } + + return 0; +} + +/** + * eeh_iommu_group_to_pe - Convert IOMMU group to EEH PE + * @group: IOMMU group + * + * The routine is called to convert IOMMU group to EEH PE. + */ +struct eeh_pe *eeh_iommu_group_to_pe(struct iommu_group *group) +{ + struct pci_dev *pdev = NULL; + struct eeh_dev *edev; + int ret; + + /* No IOMMU group ? */ + if (!group) + return NULL; + + ret = iommu_group_for_each_dev(group, &pdev, dev_has_iommu_table); + if (!ret || !pdev) + return NULL; + + /* No EEH device or PE ? */ + edev = pci_dev_to_eeh_dev(pdev); + if (!edev || !edev->pe) + return NULL; + + return edev->pe; +} +EXPORT_SYMBOL_GPL(eeh_iommu_group_to_pe); + +#endif /* CONFIG_IOMMU_API */ + +/** + * eeh_pe_set_option - Set options for the indicated PE + * @pe: EEH PE + * @option: requested option + * + * The routine is called to enable or disable EEH functionality + * on the indicated PE, to enable IO or DMA for the frozen PE. + */ +int eeh_pe_set_option(struct eeh_pe *pe, int option) +{ + int ret = 0; + + /* Invalid PE ? */ + if (!pe) + return -ENODEV; + + /* + * EEH functionality could possibly be disabled, just + * return error for the case. And the EEH functinality + * isn't expected to be disabled on one specific PE. + */ + switch (option) { + case EEH_OPT_ENABLE: + if (eeh_enabled()) { + ret = eeh_pe_change_owner(pe); + break; + } + ret = -EIO; + break; + case EEH_OPT_DISABLE: + break; + case EEH_OPT_THAW_MMIO: + case EEH_OPT_THAW_DMA: + if (!eeh_ops || !eeh_ops->set_option) { + ret = -ENOENT; + break; + } + + ret = eeh_pci_enable(pe, option); + break; + default: + pr_debug("%s: Option %d out of range (%d, %d)\n", + __func__, option, EEH_OPT_DISABLE, EEH_OPT_THAW_DMA); + ret = -EINVAL; + } + + return ret; +} +EXPORT_SYMBOL_GPL(eeh_pe_set_option); + +/** + * eeh_pe_get_state - Retrieve PE's state + * @pe: EEH PE + * + * Retrieve the PE's state, which includes 3 aspects: enabled + * DMA, enabled IO and asserted reset. + */ +int eeh_pe_get_state(struct eeh_pe *pe) +{ + int result, ret = 0; + bool rst_active, dma_en, mmio_en; + + /* Existing PE ? */ + if (!pe) + return -ENODEV; + + if (!eeh_ops || !eeh_ops->get_state) + return -ENOENT; + + result = eeh_ops->get_state(pe, NULL); + rst_active = !!(result & EEH_STATE_RESET_ACTIVE); + dma_en = !!(result & EEH_STATE_DMA_ENABLED); + mmio_en = !!(result & EEH_STATE_MMIO_ENABLED); + + if (rst_active) + ret = EEH_PE_STATE_RESET; + else if (dma_en && mmio_en) + ret = EEH_PE_STATE_NORMAL; + else if (!dma_en && !mmio_en) + ret = EEH_PE_STATE_STOPPED_IO_DMA; + else if (!dma_en && mmio_en) + ret = EEH_PE_STATE_STOPPED_DMA; + else + ret = EEH_PE_STATE_UNAVAIL; + + return ret; +} +EXPORT_SYMBOL_GPL(eeh_pe_get_state); + +static int eeh_pe_reenable_devices(struct eeh_pe *pe) +{ + struct eeh_dev *edev, *tmp; + struct pci_dev *pdev; + int ret = 0; + + /* Restore config space */ + eeh_pe_restore_bars(pe); + + /* + * Reenable PCI devices as the devices passed + * through are always enabled before the reset. + */ + eeh_pe_for_each_dev(pe, edev, tmp) { + pdev = eeh_dev_to_pci_dev(edev); + if (!pdev) + continue; + + ret = pci_reenable_device(pdev); + if (ret) { + pr_warn("%s: Failure %d reenabling %s\n", + __func__, ret, pci_name(pdev)); + return ret; + } + } + + /* The PE is still in frozen state */ + return eeh_unfreeze_pe(pe, true); +} + +/** + * eeh_pe_reset - Issue PE reset according to specified type + * @pe: EEH PE + * @option: reset type + * + * The routine is called to reset the specified PE with the + * indicated type, either fundamental reset or hot reset. + * PE reset is the most important part for error recovery. + */ +int eeh_pe_reset(struct eeh_pe *pe, int option) +{ + int ret = 0; + + /* Invalid PE ? */ + if (!pe) + return -ENODEV; + + if (!eeh_ops || !eeh_ops->set_option || !eeh_ops->reset) + return -ENOENT; + + switch (option) { + case EEH_RESET_DEACTIVATE: + ret = eeh_ops->reset(pe, option); + eeh_pe_state_clear(pe, EEH_PE_CFG_BLOCKED); + if (ret) + break; + + ret = eeh_pe_reenable_devices(pe); + break; + case EEH_RESET_HOT: + case EEH_RESET_FUNDAMENTAL: + /* + * Proactively freeze the PE to drop all MMIO access + * during reset, which should be banned as it's always + * cause recursive EEH error. + */ + eeh_ops->set_option(pe, EEH_OPT_FREEZE_PE); + + 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); + +static int proc_eeh_show(struct seq_file *m, void *v) +{ + if (!eeh_enabled()) { + seq_printf(m, "EEH Subsystem is globally disabled\n"); + seq_printf(m, "eeh_total_mmio_ffs=%llu\n", eeh_stats.total_mmio_ffs); + } else { + seq_printf(m, "EEH Subsystem is enabled\n"); + seq_printf(m, + "no device=%llu\n" + "no device node=%llu\n" + "no config address=%llu\n" + "check not wanted=%llu\n" + "eeh_total_mmio_ffs=%llu\n" + "eeh_false_positives=%llu\n" + "eeh_slot_resets=%llu\n", + eeh_stats.no_device, + eeh_stats.no_dn, + eeh_stats.no_cfg_addr, + eeh_stats.ignored_check, + eeh_stats.total_mmio_ffs, + eeh_stats.false_positives, + eeh_stats.slot_resets); + } + + return 0; +} + +static int proc_eeh_open(struct inode *inode, struct file *file) +{ + return single_open(file, proc_eeh_show, NULL); +} + +static const struct file_operations proc_eeh_operations = { + .open = proc_eeh_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +#ifdef CONFIG_DEBUG_FS +static int eeh_enable_dbgfs_set(void *data, u64 val) +{ + if (val) + eeh_clear_flag(EEH_FORCE_DISABLED); + else + eeh_add_flag(EEH_FORCE_DISABLED); + + /* Notify the backend */ + if (eeh_ops->post_init) + eeh_ops->post_init(); + + return 0; +} + +static int eeh_enable_dbgfs_get(void *data, u64 *val) +{ + if (eeh_enabled()) + *val = 0x1ul; + else + *val = 0x0ul; + return 0; +} + +static int eeh_freeze_dbgfs_set(void *data, u64 val) +{ + eeh_max_freezes = val; + return 0; +} + +static int eeh_freeze_dbgfs_get(void *data, u64 *val) +{ + *val = eeh_max_freezes; + return 0; +} + +DEFINE_SIMPLE_ATTRIBUTE(eeh_enable_dbgfs_ops, eeh_enable_dbgfs_get, + eeh_enable_dbgfs_set, "0x%llx\n"); +DEFINE_SIMPLE_ATTRIBUTE(eeh_freeze_dbgfs_ops, eeh_freeze_dbgfs_get, + eeh_freeze_dbgfs_set, "0x%llx\n"); +#endif + +static int __init eeh_init_proc(void) +{ + if (machine_is(pseries) || machine_is(powernv)) { + proc_create("powerpc/eeh", 0, NULL, &proc_eeh_operations); +#ifdef CONFIG_DEBUG_FS + debugfs_create_file("eeh_enable", 0600, + powerpc_debugfs_root, NULL, + &eeh_enable_dbgfs_ops); + debugfs_create_file("eeh_max_freezes", 0600, + powerpc_debugfs_root, NULL, + &eeh_freeze_dbgfs_ops); +#endif + } + + return 0; +} +__initcall(eeh_init_proc); |