| /* |
| * 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/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/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); |
| |
| /* 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); |
| |
| /* Buffer for reporting pci register dumps. Its here in BSS, and |
| * not dynamically alloced, so that it ends up in RMO where RTAS |
| * can access it. |
| */ |
| #define EEH_PCI_REGS_LOG_LEN 4096 |
| static unsigned char pci_regs_buf[EEH_PCI_REGS_LOG_LEN]; |
| |
| /* |
| * The struct is used to maintain the EEH global statistic |
| * information. Besides, the EEH global statistics will be |
| * exported to user space through procfs |
| */ |
| struct eeh_stats { |
| u64 no_device; /* PCI device not found */ |
| u64 no_dn; /* OF node not found */ |
| u64 no_cfg_addr; /* Config address not found */ |
| u64 ignored_check; /* EEH check skipped */ |
| u64 total_mmio_ffs; /* Total EEH checks */ |
| u64 false_positives; /* Unnecessary EEH checks */ |
| u64 slot_resets; /* PE reset */ |
| }; |
| |
| static struct eeh_stats eeh_stats; |
| |
| #define IS_BRIDGE(class_code) (((class_code)<<16) == PCI_BASE_CLASS_BRIDGE) |
| |
| static int __init eeh_setup(char *str) |
| { |
| if (!strcmp(str, "off")) |
| eeh_subsystem_flags |= EEH_FORCE_DISABLED; |
| |
| return 1; |
| } |
| __setup("eeh=", eeh_setup); |
| |
| /** |
| * eeh_gather_pci_data - Copy assorted PCI config space registers to buff |
| * @edev: device to report data for |
| * @buf: point to buffer in which to log |
| * @len: amount of room in buffer |
| * |
| * This routine captures assorted PCI configuration space data, |
| * and puts them into a buffer for RTAS error logging. |
| */ |
| static size_t eeh_gather_pci_data(struct eeh_dev *edev, char * buf, size_t len) |
| { |
| struct device_node *dn = eeh_dev_to_of_node(edev); |
| u32 cfg; |
| int cap, i; |
| int n = 0; |
| |
| n += scnprintf(buf+n, len-n, "%s\n", dn->full_name); |
| pr_warn("EEH: of node=%s\n", dn->full_name); |
| |
| eeh_ops->read_config(dn, PCI_VENDOR_ID, 4, &cfg); |
| n += scnprintf(buf+n, len-n, "dev/vend:%08x\n", cfg); |
| pr_warn("EEH: PCI device/vendor: %08x\n", cfg); |
| |
| eeh_ops->read_config(dn, PCI_COMMAND, 4, &cfg); |
| n += scnprintf(buf+n, len-n, "cmd/stat:%x\n", cfg); |
| pr_warn("EEH: PCI cmd/status register: %08x\n", cfg); |
| |
| /* Gather bridge-specific registers */ |
| if (edev->mode & EEH_DEV_BRIDGE) { |
| eeh_ops->read_config(dn, 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(dn, 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(dn, 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(dn, 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(dn, cap+4*i, 4, &cfg); |
| n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg); |
| pr_warn("EEH: PCI-E %02x: %08x\n", i, cfg); |
| } |
| } |
| |
| /* 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<14; i++) { |
| eeh_ops->read_config(dn, cap+4*i, 4, &cfg); |
| n += scnprintf(buf+n, len-n, "%02x:%x\n", 4*i, cfg); |
| pr_warn("EEH: PCI-E AER %02x: %08x\n", i, cfg); |
| } |
| } |
| |
| return n; |
| } |
| |
| /** |
| * eeh_slot_error_detail - Generate combined log including driver log and error log |
| * @pe: EEH PE |
| * @severity: temporary or permanent error log |
| * |
| * This routine should be called to generate the combined log, which |
| * is comprised of driver log and error log. The driver log is figured |
| * out from the config space of the corresponding PCI device, while |
| * the error log is fetched through platform dependent function call. |
| */ |
| void eeh_slot_error_detail(struct eeh_pe *pe, int severity) |
| { |
| size_t loglen = 0; |
| struct eeh_dev *edev, *tmp; |
| |
| /* |
| * 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_probe_mode_devtree()) |
| eeh_pci_enable(pe, EEH_OPT_THAW_MMIO); |
| eeh_ops->configure_bridge(pe); |
| eeh_pe_restore_bars(pe); |
| |
| pci_regs_buf[0] = 0; |
| eeh_pe_for_each_dev(pe, edev, tmp) { |
| loglen += eeh_gather_pci_data(edev, pci_regs_buf + loglen, |
| EEH_PCI_REGS_LOG_LEN - loglen); |
| } |
| } |
| |
| eeh_ops->get_log(pe, severity, pci_regs_buf, loglen); |
| } |
| |
| /** |
| * eeh_token_to_phys - Convert EEH address token to phys address |
| * @token: I/O token, should be address in the form 0xA.... |
| * |
| * This routine should be called to convert virtual I/O address |
| * to physical one. |
| */ |
| static inline unsigned long eeh_token_to_phys(unsigned long token) |
| { |
| pte_t *ptep; |
| unsigned long pa; |
| int hugepage_shift; |
| |
| /* |
| * We won't find hugepages here, iomem |
| */ |
| ptep = find_linux_pte_or_hugepte(init_mm.pgd, token, &hugepage_shift); |
| if (!ptep) |
| return token; |
| WARN_ON(hugepage_shift); |
| pa = pte_pfn(*ptep) << PAGE_SHIFT; |
| |
| return pa | (token & (PAGE_SIZE-1)); |
| } |
| |
| /* |
| * On PowerNV platform, we might already have fenced PHB there. |
| * For that case, it's meaningless to recover frozen PE. Intead, |
| * We have to handle fenced PHB firstly. |
| */ |
| static int eeh_phb_check_failure(struct eeh_pe *pe) |
| { |
| struct eeh_pe *phb_pe; |
| unsigned long flags; |
| int ret; |
| |
| if (!eeh_probe_mode_dev()) |
| return -EPERM; |
| |
| /* Find the PHB PE */ |
| phb_pe = eeh_phb_pe_get(pe->phb); |
| if (!phb_pe) { |
| pr_warning("%s Can't find PE for PHB#%d\n", |
| __func__, pe->phb->global_number); |
| return -EEXIST; |
| } |
| |
| /* If the PHB has been in problematic state */ |
| eeh_serialize_lock(&flags); |
| if (phb_pe->state & EEH_PE_ISOLATED) { |
| 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\n", |
| phb_pe->phb->global_number); |
| 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; |
| unsigned long flags; |
| struct device_node *dn; |
| struct pci_dev *dev; |
| struct eeh_pe *pe; |
| int rc = 0; |
| const char *location; |
| |
| eeh_stats.total_mmio_ffs++; |
| |
| if (!eeh_enabled()) |
| return 0; |
| |
| if (!edev) { |
| eeh_stats.no_dn++; |
| return 0; |
| } |
| dn = eeh_dev_to_of_node(edev); |
| dev = eeh_dev_to_pci_dev(edev); |
| pe = edev->pe; |
| |
| /* Access to IO BARs might get this far and still not want checking. */ |
| if (!pe) { |
| eeh_stats.ignored_check++; |
| pr_debug("EEH: Ignored check for %s %s\n", |
| eeh_pci_name(dev), dn->full_name); |
| return 0; |
| } |
| |
| if (!pe->addr && !pe->config_addr) { |
| eeh_stats.no_cfg_addr++; |
| return 0; |
| } |
| |
| /* |
| * On PowerNV platform, we might already have fenced PHB |
| * there and we need take care of that firstly. |
| */ |
| ret = eeh_phb_check_failure(pe); |
| if (ret > 0) |
| return ret; |
| |
| /* If we already have a pending isolation event for this |
| * slot, we know it's bad already, we don't need to check. |
| * Do this checking under a lock; as multiple PCI devices |
| * in one slot might report errors simultaneously, and we |
| * only want one error recovery routine running. |
| */ |
| eeh_serialize_lock(&flags); |
| rc = 1; |
| if (pe->state & EEH_PE_ISOLATED) { |
| pe->check_count++; |
| if (pe->check_count % EEH_MAX_FAILS == 0) { |
| location = of_get_property(dn, "ibm,loc-code", NULL); |
| printk(KERN_ERR "EEH: %d reads ignored for recovering device at " |
| "location=%s driver=%s pci addr=%s\n", |
| pe->check_count, location, |
| eeh_driver_name(dev), eeh_pci_name(dev)); |
| printk(KERN_ERR "EEH: Might be infinite loop in %s driver\n", |
| eeh_driver_name(dev)); |
| dump_stack(); |
| } |
| goto dn_unlock; |
| } |
| |
| /* |
| * Now test for an EEH failure. This is VERY expensive. |
| * Note that the eeh_config_addr may be a parent device |
| * in the case of a device behind a bridge, or it may be |
| * function zero of a multi-function device. |
| * In any case they must share a common PHB. |
| */ |
| ret = eeh_ops->get_state(pe, NULL); |
| |
| /* Note that config-io to empty slots may fail; |
| * they are empty when they don't have children. |
| * We will punt with the following conditions: Failure to get |
| * PE's state, EEH not support and Permanently unavailable |
| * state, PE is in good state. |
| */ |
| if ((ret < 0) || |
| (ret == EEH_STATE_NOT_SUPPORT) || |
| (ret & (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) == |
| (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE)) { |
| eeh_stats.false_positives++; |
| pe->false_positives++; |
| rc = 0; |
| goto dn_unlock; |
| } |
| |
| eeh_stats.slot_resets++; |
| |
| /* Avoid repeated reports of this failure, including problems |
| * with other functions on this device, and functions under |
| * bridges. |
| */ |
| eeh_pe_state_mark(pe, EEH_PE_ISOLATED); |
| eeh_serialize_unlock(flags); |
| |
| /* Most EEH events are due to device driver bugs. Having |
| * a stack trace will help the device-driver authors figure |
| * out what happened. So print that out. |
| */ |
| pr_err("EEH: Frozen PE#%x detected on PHB#%x\n", |
| pe->addr, pe->phb->global_number); |
| dump_stack(); |
| |
| 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 token, should be address in the form 0xA.... |
| * @val: value, should be all 1's (XXX why do we need this arg??) |
| * |
| * Check for an EEH failure at the given token address. Call this |
| * routine if the result of a read was all 0xff's and you want to |
| * find out if this is due to an EEH slot freeze event. This routine |
| * will query firmware for the EEH status. |
| * |
| * Note this routine is safe to call in an interrupt context. |
| */ |
| unsigned long eeh_check_failure(const volatile void __iomem *token, unsigned long val) |
| { |
| unsigned long addr; |
| struct eeh_dev *edev; |
| |
| /* Finding the phys addr + pci device; this is pretty quick. */ |
| addr = eeh_token_to_phys((unsigned long __force) token); |
| edev = eeh_addr_cache_get_dev(addr); |
| if (!edev) { |
| eeh_stats.no_device++; |
| return val; |
| } |
| |
| eeh_dev_check_failure(edev); |
| return val; |
| } |
| |
| EXPORT_SYMBOL(eeh_check_failure); |
| |
| |
| /** |
| * eeh_pci_enable - Enable MMIO or DMA transfers for this slot |
| * @pe: EEH PE |
| * |
| * This routine should be called to reenable frozen MMIO or DMA |
| * so that it would work correctly again. It's useful while doing |
| * recovery or log collection on the indicated device. |
| */ |
| int eeh_pci_enable(struct eeh_pe *pe, int function) |
| { |
| int rc, flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE); |
| |
| /* |
| * 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 the check here. |
| */ |
| if (function == EEH_OPT_THAW_MMIO || |
| function == EEH_OPT_THAW_DMA) { |
| rc = eeh_ops->get_state(pe, NULL); |
| if (rc < 0) |
| return rc; |
| |
| /* Needn't to enable or already enabled */ |
| if ((rc == EEH_STATE_NOT_SUPPORT) || |
| ((rc & flags) == flags)) |
| return 0; |
| } |
| |
| 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); |
| |
| rc = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); |
| if (rc <= 0) |
| return rc; |
| |
| if ((function == EEH_OPT_THAW_MMIO) && |
| (rc & EEH_STATE_MMIO_ENABLED)) |
| return 0; |
| |
| if ((function == EEH_OPT_THAW_DMA) && |
| (rc & EEH_STATE_DMA_ENABLED)) |
| return 0; |
| |
| return rc; |
| } |
| |
| /** |
| * pcibios_set_pcie_slot_reset - Set PCI-E reset state |
| * @dev: pci device struct |
| * @state: reset state to enter |
| * |
| * Return value: |
| * 0 if success |
| */ |
| int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state) |
| { |
| struct eeh_dev *edev = pci_dev_to_eeh_dev(dev); |
| struct eeh_pe *pe = edev->pe; |
| |
| if (!pe) { |
| pr_err("%s: No PE found on PCI device %s\n", |
| __func__, pci_name(dev)); |
| return -EINVAL; |
| } |
| |
| switch (state) { |
| case pcie_deassert_reset: |
| eeh_ops->reset(pe, EEH_RESET_DEACTIVATE); |
| break; |
| case pcie_hot_reset: |
| eeh_ops->reset(pe, EEH_RESET_HOT); |
| break; |
| case pcie_warm_reset: |
| eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL); |
| break; |
| default: |
| return -EINVAL; |
| }; |
| |
| return 0; |
| } |
| |
| /** |
| * eeh_set_pe_freset - Check the required reset for the indicated device |
| * @data: EEH device |
| * @flag: return value |
| * |
| * Each device might have its preferred reset type: fundamental or |
| * hot reset. The routine is used to collected the information for |
| * the indicated device and its children so that the bunch of the |
| * devices could be reset properly. |
| */ |
| static void *eeh_set_dev_freset(void *data, void *flag) |
| { |
| struct pci_dev *dev; |
| unsigned int *freset = (unsigned int *)flag; |
| struct eeh_dev *edev = (struct eeh_dev *)data; |
| |
| dev = eeh_dev_to_pci_dev(edev); |
| if (dev) |
| *freset |= dev->needs_freset; |
| |
| return NULL; |
| } |
| |
| /** |
| * eeh_reset_pe_once - Assert the pci #RST line for 1/4 second |
| * @pe: EEH PE |
| * |
| * Assert the PCI #RST line for 1/4 second. |
| */ |
| static void eeh_reset_pe_once(struct eeh_pe *pe) |
| { |
| unsigned int freset = 0; |
| |
| /* Determine type of EEH reset required for |
| * Partitionable Endpoint, a hot-reset (1) |
| * or a fundamental reset (3). |
| * A fundamental reset required by any device under |
| * Partitionable Endpoint trumps hot-reset. |
| */ |
| eeh_pe_dev_traverse(pe, eeh_set_dev_freset, &freset); |
| |
| if (freset) |
| eeh_ops->reset(pe, EEH_RESET_FUNDAMENTAL); |
| else |
| eeh_ops->reset(pe, EEH_RESET_HOT); |
| |
| 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, rc; |
| |
| /* 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. |
| */ |
| rc = eeh_ops->wait_state(pe, PCI_BUS_RESET_WAIT_MSEC); |
| if ((rc & flags) == flags) |
| return 0; |
| |
| if (rc < 0) { |
| pr_err("%s: Unrecoverable slot failure on PHB#%d-PE#%x", |
| __func__, pe->phb->global_number, pe->addr); |
| return -1; |
| } |
| pr_err("EEH: bus reset %d failed on PHB#%d-PE#%x, rc=%d\n", |
| i+1, pe->phb->global_number, pe->addr, rc); |
| } |
| |
| return -1; |
| } |
| |
| /** |
| * eeh_save_bars - Save device bars |
| * @edev: PCI device associated EEH device |
| * |
| * Save the values of the device bars. Unlike the restore |
| * routine, this routine is *not* recursive. This is because |
| * PCI devices are added individually; but, for the restore, |
| * an entire slot is reset at a time. |
| */ |
| void eeh_save_bars(struct eeh_dev *edev) |
| { |
| int i; |
| struct device_node *dn; |
| |
| if (!edev) |
| return; |
| dn = eeh_dev_to_of_node(edev); |
| |
| for (i = 0; i < 16; i++) |
| eeh_ops->read_config(dn, i * 4, 4, &edev->config_space[i]); |
| |
| /* |
| * 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_warning("%s: Invalid EEH ops name for %p\n", |
| __func__, ops); |
| return -EINVAL; |
| } |
| |
| if (eeh_ops && eeh_ops != ops) { |
| pr_warning("%s: EEH ops of platform %s already existing (%s)\n", |
| __func__, eeh_ops->name, ops->name); |
| return -EEXIST; |
| } |
| |
| eeh_ops = ops; |
| |
| return 0; |
| } |
| |
| /** |
| * eeh_ops_unregister - Unreigster platform dependent EEH operations |
| * @name: name of EEH platform operations |
| * |
| * Unregister the platform dependent EEH operation callback |
| * functions. |
| */ |
| int __exit eeh_ops_unregister(const char *name) |
| { |
| if (!name || !strlen(name)) { |
| pr_warning("%s: Invalid EEH ops name\n", |
| __func__); |
| return -EINVAL; |
| } |
| |
| if (eeh_ops && !strcmp(eeh_ops->name, name)) { |
| eeh_ops = NULL; |
| return 0; |
| } |
| |
| return -EEXIST; |
| } |
| |
| static int eeh_reboot_notifier(struct notifier_block *nb, |
| unsigned long action, void *unused) |
| { |
| eeh_set_enable(false); |
| 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 device_node *phb; |
| static int cnt = 0; |
| int ret = 0; |
| |
| /* |
| * We have to delay the initialization on PowerNV after |
| * the PCI hierarchy tree has been built because the PEs |
| * are figured out based on PCI devices instead of device |
| * tree nodes |
| */ |
| if (machine_is(powernv) && cnt++ <= 0) |
| return ret; |
| |
| /* 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_warning("%s: Platform EEH operation not found\n", |
| __func__); |
| return -EEXIST; |
| } else if ((ret = eeh_ops->init())) { |
| pr_warning("%s: Failed to call platform init function (%d)\n", |
| __func__, ret); |
| return ret; |
| } |
| |
| /* Initialize EEH event */ |
| ret = eeh_event_init(); |
| if (ret) |
| return ret; |
| |
| /* Enable EEH for all adapters */ |
| if (eeh_probe_mode_devtree()) { |
| list_for_each_entry_safe(hose, tmp, |
| &hose_list, list_node) { |
| phb = hose->dn; |
| traverse_pci_devices(phb, eeh_ops->of_probe, NULL); |
| } |
| } else if (eeh_probe_mode_dev()) { |
| list_for_each_entry_safe(hose, tmp, |
| &hose_list, list_node) |
| pci_walk_bus(hose->bus, eeh_ops->dev_probe, NULL); |
| } else { |
| pr_warn("%s: Invalid probe mode %x", |
| __func__, eeh_subsystem_flags); |
| return -EINVAL; |
| } |
| |
| /* |
| * Call platform post-initialization. Actually, It's good chance |
| * to inform platform that EEH is ready to supply service if the |
| * I/O cache stuff has been built up. |
| */ |
| if (eeh_ops->post_init) { |
| ret = eeh_ops->post_init(); |
| if (ret) |
| return ret; |
| } |
| |
| if (eeh_enabled()) |
| pr_info("EEH: PCI Enhanced I/O Error Handling Enabled\n"); |
| else |
| pr_warning("EEH: No capable adapters found\n"); |
| |
| return ret; |
| } |
| |
| core_initcall_sync(eeh_init); |
| |
| /** |
| * eeh_add_device_early - Enable EEH for the indicated device_node |
| * @dn: device node for which to set up EEH |
| * |
| * This routine must be used to perform EEH initialization for PCI |
| * devices that were added after system boot (e.g. hotplug, dlpar). |
| * This routine must be called before any i/o is performed to the |
| * adapter (inluding any config-space i/o). |
| * Whether this actually enables EEH or not for this device depends |
| * on the CEC architecture, type of the device, on earlier boot |
| * command-line arguments & etc. |
| */ |
| void eeh_add_device_early(struct device_node *dn) |
| { |
| struct pci_controller *phb; |
| |
| /* |
| * If we're doing EEH probe based on PCI device, we |
| * would delay the probe until late stage because |
| * the PCI device isn't available this moment. |
| */ |
| if (!eeh_probe_mode_devtree()) |
| return; |
| |
| if (!of_node_to_eeh_dev(dn)) |
| return; |
| phb = of_node_to_eeh_dev(dn)->phb; |
| |
| /* USB Bus children of PCI devices will not have BUID's */ |
| if (NULL == phb || 0 == phb->buid) |
| return; |
| |
| eeh_ops->of_probe(dn, NULL); |
| } |
| |
| /** |
| * eeh_add_device_tree_early - Enable EEH for the indicated device |
| * @dn: device node |
| * |
| * This routine must be used to perform EEH initialization for the |
| * indicated PCI device that was added after system boot (e.g. |
| * hotplug, dlpar). |
| */ |
| void eeh_add_device_tree_early(struct device_node *dn) |
| { |
| struct device_node *sib; |
| |
| for_each_child_of_node(dn, sib) |
| eeh_add_device_tree_early(sib); |
| eeh_add_device_early(dn); |
| } |
| EXPORT_SYMBOL_GPL(eeh_add_device_tree_early); |
| |
| /** |
| * eeh_add_device_late - Perform EEH initialization for the indicated pci device |
| * @dev: pci device for which to set up EEH |
| * |
| * This routine must be used to complete EEH initialization for PCI |
| * devices that were added after system boot (e.g. hotplug, dlpar). |
| */ |
| void eeh_add_device_late(struct pci_dev *dev) |
| { |
| struct device_node *dn; |
| struct eeh_dev *edev; |
| |
| if (!dev || !eeh_enabled()) |
| return; |
| |
| pr_debug("EEH: Adding device %s\n", pci_name(dev)); |
| |
| dn = pci_device_to_OF_node(dev); |
| edev = of_node_to_eeh_dev(dn); |
| if (edev->pdev == dev) { |
| pr_debug("EEH: Already referenced !\n"); |
| return; |
| } |
| |
| /* |
| * 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; |
| |
| /* |
| * We have to do the EEH probe here because the PCI device |
| * hasn't been created yet in the early stage. |
| */ |
| if (eeh_probe_mode_dev()) |
| eeh_ops->dev_probe(dev, NULL); |
| |
| eeh_addr_cache_insert_dev(dev); |
| } |
| |
| /** |
| * eeh_add_device_tree_late - Perform EEH initialization for the indicated PCI bus |
| * @bus: PCI bus |
| * |
| * This routine must be used to perform EEH initialization for PCI |
| * devices which are attached to the indicated PCI bus. The PCI bus |
| * is added after system boot through hotplug or dlpar. |
| */ |
| void eeh_add_device_tree_late(struct pci_bus *bus) |
| { |
| struct pci_dev *dev; |
| |
| list_for_each_entry(dev, &bus->devices, bus_list) { |
| eeh_add_device_late(dev); |
| if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { |
| struct pci_bus *subbus = dev->subordinate; |
| if (subbus) |
| eeh_add_device_tree_late(subbus); |
| } |
| } |
| } |
| EXPORT_SYMBOL_GPL(eeh_add_device_tree_late); |
| |
| /** |
| * eeh_add_sysfs_files - Add EEH sysfs files for the indicated PCI bus |
| * @bus: PCI bus |
| * |
| * This routine must be used to add EEH sysfs files for PCI |
| * devices which are attached to the indicated PCI bus. The PCI bus |
| * is added after system boot through hotplug or dlpar. |
| */ |
| void eeh_add_sysfs_files(struct pci_bus *bus) |
| { |
| struct pci_dev *dev; |
| |
| list_for_each_entry(dev, &bus->devices, bus_list) { |
| eeh_sysfs_add_device(dev); |
| if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE) { |
| struct pci_bus *subbus = dev->subordinate; |
| if (subbus) |
| eeh_add_sysfs_files(subbus); |
| } |
| } |
| } |
| EXPORT_SYMBOL_GPL(eeh_add_sysfs_files); |
| |
| /** |
| * eeh_remove_device - Undo EEH setup for the indicated pci device |
| * @dev: pci device to be removed |
| * |
| * 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; |
| } |
| |
| 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_subsystem_flags &= ~EEH_FORCE_DISABLED; |
| else |
| eeh_subsystem_flags |= 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; |
| } |
| |
| DEFINE_SIMPLE_ATTRIBUTE(eeh_enable_dbgfs_ops, eeh_enable_dbgfs_get, |
| eeh_enable_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); |
| #endif |
| } |
| |
| return 0; |
| } |
| __initcall(eeh_init_proc); |