summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/eeh.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/kernel/eeh.c')
-rw-r--r--arch/powerpc/kernel/eeh.c1747
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);