// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * PowerNV Platform dependent EEH operations
 *
 * Copyright Benjamin Herrenschmidt & Gavin Shan, IBM Corporation 2013.
 */

#include <linux/atomic.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/irqdomain.h>
#include <linux/list.h>
#include <linux/msi.h>
#include <linux/of.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/rbtree.h>
#include <linux/sched.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>

#include <asm/eeh.h>
#include <asm/eeh_event.h>
#include <asm/firmware.h>
#include <asm/io.h>
#include <asm/iommu.h>
#include <asm/machdep.h>
#include <asm/msi_bitmap.h>
#include <asm/opal.h>
#include <asm/ppc-pci.h>
#include <asm/pnv-pci.h>

#include "powernv.h"
#include "pci.h"
#include "../../../../drivers/pci/pci.h"

static int eeh_event_irq = -EINVAL;

static void pnv_pcibios_bus_add_device(struct pci_dev *pdev)
{
        dev_dbg(&pdev->dev, "EEH: Setting up device\n");
        eeh_probe_device(pdev);
}

static irqreturn_t pnv_eeh_event(int irq, void *data)
{
        /*
         * We simply send a special EEH event if EEH has been
         * enabled. We don't care about EEH events until we've
         * finished processing the outstanding ones. Event processing
         * gets unmasked in next_error() if EEH is enabled.
         */
        disable_irq_nosync(irq);

        if (eeh_enabled())
                eeh_send_failure_event(NULL);

        return IRQ_HANDLED;
}

#ifdef CONFIG_DEBUG_FS
static ssize_t pnv_eeh_ei_write(struct file *filp,
                                const char __user *user_buf,
                                size_t count, loff_t *ppos)
{
        struct pci_controller *hose = filp->private_data;
        struct eeh_pe *pe;
        int pe_no, type, func;
        unsigned long addr, mask;
        char buf[50];
        int ret;

        if (!eeh_ops || !eeh_ops->err_inject)
                return -ENXIO;

        /* Copy over argument buffer */
        ret = simple_write_to_buffer(buf, sizeof(buf), ppos, user_buf, count);
        if (!ret)
                return -EFAULT;

        /* Retrieve parameters */
        ret = sscanf(buf, "%x:%x:%x:%lx:%lx",
                     &pe_no, &type, &func, &addr, &mask);
        if (ret != 5)
                return -EINVAL;

        /* Retrieve PE */
        pe = eeh_pe_get(hose, pe_no);
        if (!pe)
                return -ENODEV;

        /* Do error injection */
        ret = eeh_ops->err_inject(pe, type, func, addr, mask);
        return ret < 0 ? ret : count;
}

static const struct file_operations pnv_eeh_ei_fops = {
        .open   = simple_open,
        .write  = pnv_eeh_ei_write,
};

static int pnv_eeh_dbgfs_set(void *data, int offset, u64 val)
{
        struct pci_controller *hose = data;
        struct pnv_phb *phb = hose->private_data;

        out_be64(phb->regs + offset, val);
        return 0;
}

static int pnv_eeh_dbgfs_get(void *data, int offset, u64 *val)
{
        struct pci_controller *hose = data;
        struct pnv_phb *phb = hose->private_data;

        *val = in_be64(phb->regs + offset);
        return 0;
}

#define PNV_EEH_DBGFS_ENTRY(name, reg)                          \
static int pnv_eeh_dbgfs_set_##name(void *data, u64 val)        \
{                                                               \
        return pnv_eeh_dbgfs_set(data, reg, val);               \
}                                                               \
                                                                \
static int pnv_eeh_dbgfs_get_##name(void *data, u64 *val)       \
{                                                               \
        return pnv_eeh_dbgfs_get(data, reg, val);               \
}                                                               \
                                                                \
DEFINE_SIMPLE_ATTRIBUTE(pnv_eeh_dbgfs_ops_##name,               \
                        pnv_eeh_dbgfs_get_##name,               \
                        pnv_eeh_dbgfs_set_##name,               \
                        "0x%llx\n")

PNV_EEH_DBGFS_ENTRY(outb, 0xD10);
PNV_EEH_DBGFS_ENTRY(inbA, 0xD90);
PNV_EEH_DBGFS_ENTRY(inbB, 0xE10);

#endif /* CONFIG_DEBUG_FS */

static void pnv_eeh_enable_phbs(void)
{
        struct pci_controller *hose;
        struct pnv_phb *phb;

        list_for_each_entry(hose, &hose_list, list_node) {
                phb = hose->private_data;
                /*
                 * If EEH is enabled, we're going to rely on that.
                 * Otherwise, we restore to conventional mechanism
                 * to clear frozen PE during PCI config access.
                 */
                if (eeh_enabled())
                        phb->flags |= PNV_PHB_FLAG_EEH;
                else
                        phb->flags &= ~PNV_PHB_FLAG_EEH;
        }
}

/**
 * pnv_eeh_post_init - EEH platform dependent post initialization
 *
 * EEH platform dependent post initialization on powernv. When
 * the function is called, the EEH PEs and devices should have
 * been built. If the I/O cache staff has been built, EEH is
 * ready to supply service.
 */
int pnv_eeh_post_init(void)
{
        struct pci_controller *hose;
        struct pnv_phb *phb;
        int ret = 0;

        eeh_show_enabled();

        /* Register OPAL event notifier */
        eeh_event_irq = opal_event_request(ilog2(OPAL_EVENT_PCI_ERROR));
        if (eeh_event_irq < 0) {
                pr_err("%s: Can't register OPAL event interrupt (%d)\n",
                       __func__, eeh_event_irq);
                return eeh_event_irq;
        }

        ret = request_irq(eeh_event_irq, pnv_eeh_event,
                          IRQ_TYPE_LEVEL_HIGH, "opal-eeh", NULL);
        if (ret < 0) {
                irq_dispose_mapping(eeh_event_irq);
                pr_err("%s: Can't request OPAL event interrupt (%d)\n",
                       __func__, eeh_event_irq);
                return ret;
        }

        if (!eeh_enabled())
                disable_irq(eeh_event_irq);

        pnv_eeh_enable_phbs();

        list_for_each_entry(hose, &hose_list, list_node) {
                phb = hose->private_data;

                /* Create debugfs entries */
#ifdef CONFIG_DEBUG_FS
                if (phb->has_dbgfs || !phb->dbgfs)
                        continue;

                phb->has_dbgfs = 1;
                debugfs_create_file("err_injct", 0200,
                                    phb->dbgfs, hose,
                                    &pnv_eeh_ei_fops);

                debugfs_create_file("err_injct_outbound", 0600,
                                    phb->dbgfs, hose,
                                    &pnv_eeh_dbgfs_ops_outb);
                debugfs_create_file("err_injct_inboundA", 0600,
                                    phb->dbgfs, hose,
                                    &pnv_eeh_dbgfs_ops_inbA);
                debugfs_create_file("err_injct_inboundB", 0600,
                                    phb->dbgfs, hose,
                                    &pnv_eeh_dbgfs_ops_inbB);
#endif /* CONFIG_DEBUG_FS */
        }

        return ret;
}

static int pnv_eeh_find_cap(struct pci_dn *pdn, int cap)
{
        int pos = PCI_CAPABILITY_LIST;
        int cnt = 48;   /* Maximal number of capabilities */
        u32 status, id;

        if (!pdn)
                return 0;

        /* Check if the device supports capabilities */
        pnv_pci_cfg_read(pdn, PCI_STATUS, 2, &status);
        if (!(status & PCI_STATUS_CAP_LIST))
                return 0;

        while (cnt--) {
                pnv_pci_cfg_read(pdn, pos, 1, &pos);
                if (pos < 0x40)
                        break;

                pos &= ~3;
                pnv_pci_cfg_read(pdn, pos + PCI_CAP_LIST_ID, 1, &id);
                if (id == 0xff)
                        break;

                /* Found */
                if (id == cap)
                        return pos;

                /* Next one */
                pos += PCI_CAP_LIST_NEXT;
        }

        return 0;
}

static int pnv_eeh_find_ecap(struct pci_dn *pdn, int cap)
{
        struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
        u32 header;
        int pos = 256, ttl = (4096 - 256) / 8;

        if (!edev || !edev->pcie_cap)
                return 0;
        if (pnv_pci_cfg_read(pdn, pos, 4, &header) != PCIBIOS_SUCCESSFUL)
                return 0;
        else if (!header)
                return 0;

        while (ttl-- > 0) {
                if (PCI_EXT_CAP_ID(header) == cap && pos)
                        return pos;

                pos = PCI_EXT_CAP_NEXT(header);
                if (pos < 256)
                        break;

                if (pnv_pci_cfg_read(pdn, pos, 4, &header) != PCIBIOS_SUCCESSFUL)
                        break;
        }

        return 0;
}

static struct eeh_pe *pnv_eeh_get_upstream_pe(struct pci_dev *pdev)
{
        struct pci_controller *hose = pdev->bus->sysdata;
        struct pnv_phb *phb = hose->private_data;
        struct pci_dev *parent = pdev->bus->self;

#ifdef CONFIG_PCI_IOV
        /* for VFs we use the PF's PE as the upstream PE */
        if (pdev->is_virtfn)
                parent = pdev->physfn;
#endif

        /* otherwise use the PE of our parent bridge */
        if (parent) {
                struct pnv_ioda_pe *ioda_pe = pnv_ioda_get_pe(parent);

                return eeh_pe_get(phb->hose, ioda_pe->pe_number);
        }

        return NULL;
}

/**
 * pnv_eeh_probe - Do probe on PCI device
 * @pdev: pci_dev to probe
 *
 * Create, or find the existing, eeh_dev for this pci_dev.
 */
static struct eeh_dev *pnv_eeh_probe(struct pci_dev *pdev)
{
        struct pci_dn *pdn = pci_get_pdn(pdev);
        struct pci_controller *hose = pdn->phb;
        struct pnv_phb *phb = hose->private_data;
        struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
        struct eeh_pe *upstream_pe;
        uint32_t pcie_flags;
        int ret;
        int config_addr = (pdn->busno << 8) | (pdn->devfn);

        /*
         * When probing the root bridge, which doesn't have any
         * subordinate PCI devices. We don't have OF node for
         * the root bridge. So it's not reasonable to continue
         * the probing.
         */
        if (!edev || edev->pe)
                return NULL;

        /* already configured? */
        if (edev->pdev) {
                pr_debug("%s: found existing edev for %04x:%02x:%02x.%01x\n",
                        __func__, hose->global_number, config_addr >> 8,
                        PCI_SLOT(config_addr), PCI_FUNC(config_addr));
                return edev;
        }

        /* Skip for PCI-ISA bridge */
        if ((pdev->class >> 8) == PCI_CLASS_BRIDGE_ISA)
                return NULL;

        eeh_edev_dbg(edev, "Probing device\n");

        /* Initialize eeh device */
        edev->mode      &= 0xFFFFFF00;
        edev->pcix_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_PCIX);
        edev->pcie_cap = pnv_eeh_find_cap(pdn, PCI_CAP_ID_EXP);
        edev->af_cap   = pnv_eeh_find_cap(pdn, PCI_CAP_ID_AF);
        edev->aer_cap  = pnv_eeh_find_ecap(pdn, PCI_EXT_CAP_ID_ERR);
        if ((pdev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
                edev->mode |= EEH_DEV_BRIDGE;
                if (edev->pcie_cap) {
                        pnv_pci_cfg_read(pdn, edev->pcie_cap + PCI_EXP_FLAGS,
                                         2, &pcie_flags);
                        pcie_flags = (pcie_flags & PCI_EXP_FLAGS_TYPE) >> 4;
                        if (pcie_flags == PCI_EXP_TYPE_ROOT_PORT)
                                edev->mode |= EEH_DEV_ROOT_PORT;
                        else if (pcie_flags == PCI_EXP_TYPE_DOWNSTREAM)
                                edev->mode |= EEH_DEV_DS_PORT;
                }
        }

        edev->pe_config_addr = phb->ioda.pe_rmap[config_addr];

        upstream_pe = pnv_eeh_get_upstream_pe(pdev);

        /* Create PE */
        ret = eeh_pe_tree_insert(edev, upstream_pe);
        if (ret) {
                eeh_edev_warn(edev, "Failed to add device to PE (code %d)\n", ret);
                return NULL;
        }

        /*
         * If the PE contains any one of following adapters, the
         * PCI config space can't be accessed when dumping EEH log.
         * Otherwise, we will run into fenced PHB caused by shortage
         * of outbound credits in the adapter. The PCI config access
         * should be blocked until PE reset. MMIO access is dropped
         * by hardware certainly. In order to drop PCI config requests,
         * one more flag (EEH_PE_CFG_RESTRICTED) is introduced, which
         * will be checked in the backend for PE state retrieval. If
         * the PE becomes frozen for the first time and the flag has
         * been set for the PE, we will set EEH_PE_CFG_BLOCKED for
         * that PE to block its config space.
         *
         * Broadcom BCM5718 2-ports NICs (14e4:1656)
         * Broadcom Austin 4-ports NICs (14e4:1657)
         * Broadcom Shiner 4-ports 1G NICs (14e4:168a)
         * Broadcom Shiner 2-ports 10G NICs (14e4:168e)
         */
        if ((pdn->vendor_id == PCI_VENDOR_ID_BROADCOM &&
             pdn->device_id == 0x1656) ||
            (pdn->vendor_id == PCI_VENDOR_ID_BROADCOM &&
             pdn->device_id == 0x1657) ||
            (pdn->vendor_id == PCI_VENDOR_ID_BROADCOM &&
             pdn->device_id == 0x168a) ||
            (pdn->vendor_id == PCI_VENDOR_ID_BROADCOM &&
             pdn->device_id == 0x168e))
                edev->pe->state |= EEH_PE_CFG_RESTRICTED;

        /*
         * Cache the PE primary bus, which can't be fetched when
         * full hotplug is in progress. In that case, all child
         * PCI devices of the PE are expected to be removed prior
         * to PE reset.
         */
        if (!(edev->pe->state & EEH_PE_PRI_BUS)) {
                edev->pe->bus = pci_find_bus(hose->global_number,
                                             pdn->busno);
                if (edev->pe->bus)
                        edev->pe->state |= EEH_PE_PRI_BUS;
        }

        /*
         * Enable EEH explicitly so that we will do EEH check
         * while accessing I/O stuff
         */
        if (!eeh_has_flag(EEH_ENABLED)) {
                enable_irq(eeh_event_irq);
                pnv_eeh_enable_phbs();
                eeh_add_flag(EEH_ENABLED);
        }

        /* Save memory bars */
        eeh_save_bars(edev);

        eeh_edev_dbg(edev, "EEH enabled on device\n");

        return edev;
}

/**
 * pnv_eeh_set_option - Initialize EEH or MMIO/DMA reenable
 * @pe: EEH PE
 * @option: operation to be issued
 *
 * The function is used to control the EEH functionality globally.
 * Currently, following options are support according to PAPR:
 * Enable EEH, Disable EEH, Enable MMIO and Enable DMA
 */
static int pnv_eeh_set_option(struct eeh_pe *pe, int option)
{
        struct pci_controller *hose = pe->phb;
        struct pnv_phb *phb = hose->private_data;
        bool freeze_pe = false;
        int opt;
        s64 rc;

        switch (option) {
        case EEH_OPT_DISABLE:
                return -EPERM;
        case EEH_OPT_ENABLE:
                return 0;
        case EEH_OPT_THAW_MMIO:
                opt = OPAL_EEH_ACTION_CLEAR_FREEZE_MMIO;
                break;
        case EEH_OPT_THAW_DMA:
                opt = OPAL_EEH_ACTION_CLEAR_FREEZE_DMA;
                break;
        case EEH_OPT_FREEZE_PE:
                freeze_pe = true;
                opt = OPAL_EEH_ACTION_SET_FREEZE_ALL;
                break;
        default:
                pr_warn("%s: Invalid option %d\n", __func__, option);
                return -EINVAL;
        }

        /* Freeze master and slave PEs if PHB supports compound PEs */
        if (freeze_pe) {
                if (phb->freeze_pe) {
                        phb->freeze_pe(phb, pe->addr);
                        return 0;
                }

                rc = opal_pci_eeh_freeze_set(phb->opal_id, pe->addr, opt);
                if (rc != OPAL_SUCCESS) {
                        pr_warn("%s: Failure %lld freezing PHB#%x-PE#%x\n",
                                __func__, rc, phb->hose->global_number,
                                pe->addr);
                        return -EIO;
                }

                return 0;
        }

        /* Unfreeze master and slave PEs if PHB supports */
        if (phb->unfreeze_pe)
                return phb->unfreeze_pe(phb, pe->addr, opt);

        rc = opal_pci_eeh_freeze_clear(phb->opal_id, pe->addr, opt);
        if (rc != OPAL_SUCCESS) {
                pr_warn("%s: Failure %lld enable %d for PHB#%x-PE#%x\n",
                        __func__, rc, option, phb->hose->global_number,
                        pe->addr);
                return -EIO;
        }

        return 0;
}

static void pnv_eeh_get_phb_diag(struct eeh_pe *pe)
{
        struct pnv_phb *phb = pe->phb->private_data;
        s64 rc;

        rc = opal_pci_get_phb_diag_data2(phb->opal_id, pe->data,
                                         phb->diag_data_size);
        if (rc != OPAL_SUCCESS)
                pr_warn("%s: Failure %lld getting PHB#%x diag-data\n",
                        __func__, rc, pe->phb->global_number);
}

static int pnv_eeh_get_phb_state(struct eeh_pe *pe)
{
        struct pnv_phb *phb = pe->phb->private_data;
        u8 fstate = 0;
        __be16 pcierr = 0;
        s64 rc;
        int result = 0;

        rc = opal_pci_eeh_freeze_status(phb->opal_id,
                                        pe->addr,
                                        &fstate,
                                        &pcierr,
                                        NULL);
        if (rc != OPAL_SUCCESS) {
                pr_warn("%s: Failure %lld getting PHB#%x state\n",
                        __func__, rc, phb->hose->global_number);
                return EEH_STATE_NOT_SUPPORT;
        }

        /*
         * Check PHB state. If the PHB is frozen for the
         * first time, to dump the PHB diag-data.
         */
        if (be16_to_cpu(pcierr) != OPAL_EEH_PHB_ERROR) {
                result = (EEH_STATE_MMIO_ACTIVE  |
                          EEH_STATE_DMA_ACTIVE   |
                          EEH_STATE_MMIO_ENABLED |
                          EEH_STATE_DMA_ENABLED);
        } else if (!(pe->state & EEH_PE_ISOLATED)) {
                eeh_pe_mark_isolated(pe);
                pnv_eeh_get_phb_diag(pe);

                if (eeh_has_flag(EEH_EARLY_DUMP_LOG))
                        pnv_pci_dump_phb_diag_data(pe->phb, pe->data);
        }

        return result;
}

static int pnv_eeh_get_pe_state(struct eeh_pe *pe)
{
        struct pnv_phb *phb = pe->phb->private_data;
        u8 fstate = 0;
        __be16 pcierr = 0;
        s64 rc;
        int result;

        /*
         * We don't clobber hardware frozen state until PE
         * reset is completed. In order to keep EEH core
         * moving forward, we have to return operational
         * state during PE reset.
         */
        if (pe->state & EEH_PE_RESET) {
                result = (EEH_STATE_MMIO_ACTIVE  |
                          EEH_STATE_DMA_ACTIVE   |
                          EEH_STATE_MMIO_ENABLED |
                          EEH_STATE_DMA_ENABLED);
                return result;
        }

        /*
         * Fetch PE state from hardware. If the PHB
         * supports compound PE, let it handle that.
         */
        if (phb->get_pe_state) {
                fstate = phb->get_pe_state(phb, pe->addr);
        } else {
                rc = opal_pci_eeh_freeze_status(phb->opal_id,
                                                pe->addr,
                                                &fstate,
                                                &pcierr,
                                                NULL);
                if (rc != OPAL_SUCCESS) {
                        pr_warn("%s: Failure %lld getting PHB#%x-PE%x state\n",
                                __func__, rc, phb->hose->global_number,
                                pe->addr);
                        return EEH_STATE_NOT_SUPPORT;
                }
        }

        /* Figure out state */
        switch (fstate) {
        case OPAL_EEH_STOPPED_NOT_FROZEN:
                result = (EEH_STATE_MMIO_ACTIVE  |
                          EEH_STATE_DMA_ACTIVE   |
                          EEH_STATE_MMIO_ENABLED |
                          EEH_STATE_DMA_ENABLED);
                break;
        case OPAL_EEH_STOPPED_MMIO_FREEZE:
                result = (EEH_STATE_DMA_ACTIVE |
                          EEH_STATE_DMA_ENABLED);
                break;
        case OPAL_EEH_STOPPED_DMA_FREEZE:
                result = (EEH_STATE_MMIO_ACTIVE |
                          EEH_STATE_MMIO_ENABLED);
                break;
        case OPAL_EEH_STOPPED_MMIO_DMA_FREEZE:
                result = 0;
                break;
        case OPAL_EEH_STOPPED_RESET:
                result = EEH_STATE_RESET_ACTIVE;
                break;
        case OPAL_EEH_STOPPED_TEMP_UNAVAIL:
                result = EEH_STATE_UNAVAILABLE;
                break;
        case OPAL_EEH_STOPPED_PERM_UNAVAIL:
                result = EEH_STATE_NOT_SUPPORT;
                break;
        default:
                result = EEH_STATE_NOT_SUPPORT;
                pr_warn("%s: Invalid PHB#%x-PE#%x state %x\n",
                        __func__, phb->hose->global_number,
                        pe->addr, fstate);
        }

        /*
         * If PHB supports compound PE, to freeze all
         * slave PEs for consistency.
         *
         * If the PE is switching to frozen state for the
         * first time, to dump the PHB diag-data.
         */
        if (!(result & EEH_STATE_NOT_SUPPORT) &&
            !(result & EEH_STATE_UNAVAILABLE) &&
            !(result & EEH_STATE_MMIO_ACTIVE) &&
            !(result & EEH_STATE_DMA_ACTIVE)  &&
            !(pe->state & EEH_PE_ISOLATED)) {
                if (phb->freeze_pe)
                        phb->freeze_pe(phb, pe->addr);

                eeh_pe_mark_isolated(pe);
                pnv_eeh_get_phb_diag(pe);

                if (eeh_has_flag(EEH_EARLY_DUMP_LOG))
                        pnv_pci_dump_phb_diag_data(pe->phb, pe->data);
        }

        return result;
}

/**
 * pnv_eeh_get_state - Retrieve PE state
 * @pe: EEH PE
 * @delay: delay while PE state is temporarily unavailable
 *
 * Retrieve the state of the specified PE. For IODA-compitable
 * platform, it should be retrieved from IODA table. Therefore,
 * we prefer passing down to hardware implementation to handle
 * it.
 */
static int pnv_eeh_get_state(struct eeh_pe *pe, int *delay)
{
        int ret;

        if (pe->type & EEH_PE_PHB)
                ret = pnv_eeh_get_phb_state(pe);
        else
                ret = pnv_eeh_get_pe_state(pe);

        if (!delay)
                return ret;

        /*
         * If the PE state is temporarily unavailable,
         * to inform the EEH core delay for default
         * period (1 second)
         */
        *delay = 0;
        if (ret & EEH_STATE_UNAVAILABLE)
                *delay = 1000;

        return ret;
}

static s64 pnv_eeh_poll(unsigned long id)
{
        s64 rc = OPAL_HARDWARE;

        while (1) {
                rc = opal_pci_poll(id);
                if (rc <= 0)
                        break;

                if (system_state < SYSTEM_RUNNING)
                        udelay(1000 * rc);
                else
                        msleep(rc);
        }

        return rc;
}

int pnv_eeh_phb_reset(struct pci_controller *hose, int option)
{
        struct pnv_phb *phb = hose->private_data;
        s64 rc = OPAL_HARDWARE;

        pr_debug("%s: Reset PHB#%x, option=%d\n",
                 __func__, hose->global_number, option);

        /* Issue PHB complete reset request */
        if (option == EEH_RESET_FUNDAMENTAL ||
            option == EEH_RESET_HOT)
                rc = opal_pci_reset(phb->opal_id,
                                    OPAL_RESET_PHB_COMPLETE,
                                    OPAL_ASSERT_RESET);
        else if (option == EEH_RESET_DEACTIVATE)
                rc = opal_pci_reset(phb->opal_id,
                                    OPAL_RESET_PHB_COMPLETE,
                                    OPAL_DEASSERT_RESET);
        if (rc < 0)
                goto out;

        /*
         * Poll state of the PHB until the request is done
         * successfully. The PHB reset is usually PHB complete
         * reset followed by hot reset on root bus. So we also
         * need the PCI bus settlement delay.
         */
        if (rc > 0)
                rc = pnv_eeh_poll(phb->opal_id);
        if (option == EEH_RESET_DEACTIVATE) {
                if (system_state < SYSTEM_RUNNING)
                        udelay(1000 * EEH_PE_RST_SETTLE_TIME);
                else
                        msleep(EEH_PE_RST_SETTLE_TIME);
        }
out:
        if (rc != OPAL_SUCCESS)
                return -EIO;

        return 0;
}

static int pnv_eeh_root_reset(struct pci_controller *hose, int option)
{
        struct pnv_phb *phb = hose->private_data;
        s64 rc = OPAL_HARDWARE;

        pr_debug("%s: Reset PHB#%x, option=%d\n",
                 __func__, hose->global_number, option);

        /*
         * During the reset deassert time, we needn't care
         * the reset scope because the firmware does nothing
         * for fundamental or hot reset during deassert phase.
         */
        if (option == EEH_RESET_FUNDAMENTAL)
                rc = opal_pci_reset(phb->opal_id,
                                    OPAL_RESET_PCI_FUNDAMENTAL,
                                    OPAL_ASSERT_RESET);
        else if (option == EEH_RESET_HOT)
                rc = opal_pci_reset(phb->opal_id,
                                    OPAL_RESET_PCI_HOT,
                                    OPAL_ASSERT_RESET);
        else if (option == EEH_RESET_DEACTIVATE)
                rc = opal_pci_reset(phb->opal_id,
                                    OPAL_RESET_PCI_HOT,
                                    OPAL_DEASSERT_RESET);
        if (rc < 0)
                goto out;

        /* Poll state of the PHB until the request is done */
        if (rc > 0)
                rc = pnv_eeh_poll(phb->opal_id);
        if (option == EEH_RESET_DEACTIVATE)
                msleep(EEH_PE_RST_SETTLE_TIME);
out:
        if (rc != OPAL_SUCCESS)
                return -EIO;

        return 0;
}

static int __pnv_eeh_bridge_reset(struct pci_dev *dev, int option)
{
        struct pci_dn *pdn = pci_get_pdn_by_devfn(dev->bus, dev->devfn);
        struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
        int aer = edev ? edev->aer_cap : 0;
        u32 ctrl;

        pr_debug("%s: Secondary Reset PCI bus %04x:%02x with option %d\n",
                 __func__, pci_domain_nr(dev->bus),
                 dev->bus->number, option);

        switch (option) {
        case EEH_RESET_FUNDAMENTAL:
        case EEH_RESET_HOT:
                /* Don't report linkDown event */
                if (aer) {
                        eeh_ops->read_config(edev, aer + PCI_ERR_UNCOR_MASK,
                                             4, &ctrl);
                        ctrl |= PCI_ERR_UNC_SURPDN;
                        eeh_ops->write_config(edev, aer + PCI_ERR_UNCOR_MASK,
                                              4, ctrl);
                }

                eeh_ops->read_config(edev, PCI_BRIDGE_CONTROL, 2, &ctrl);
                ctrl |= PCI_BRIDGE_CTL_BUS_RESET;
                eeh_ops->write_config(edev, PCI_BRIDGE_CONTROL, 2, ctrl);

                msleep(EEH_PE_RST_HOLD_TIME);
                break;
        case EEH_RESET_DEACTIVATE:
                eeh_ops->read_config(edev, PCI_BRIDGE_CONTROL, 2, &ctrl);
                ctrl &= ~PCI_BRIDGE_CTL_BUS_RESET;
                eeh_ops->write_config(edev, PCI_BRIDGE_CONTROL, 2, ctrl);

                msleep(EEH_PE_RST_SETTLE_TIME);

                /* Continue reporting linkDown event */
                if (aer) {
                        eeh_ops->read_config(edev, aer + PCI_ERR_UNCOR_MASK,
                                             4, &ctrl);
                        ctrl &= ~PCI_ERR_UNC_SURPDN;
                        eeh_ops->write_config(edev, aer + PCI_ERR_UNCOR_MASK,
                                              4, ctrl);
                }

                break;
        }

        return 0;
}

static int pnv_eeh_bridge_reset(struct pci_dev *pdev, int option)
{
        struct pci_controller *hose = pci_bus_to_host(pdev->bus);
        struct pnv_phb *phb = hose->private_data;
        struct device_node *dn = pci_device_to_OF_node(pdev);
        uint64_t id = PCI_SLOT_ID(phb->opal_id, pci_dev_id(pdev));
        uint8_t scope;
        int64_t rc;

        /* Hot reset to the bus if firmware cannot handle */
        if (!dn || !of_property_present(dn, "ibm,reset-by-firmware"))
                return __pnv_eeh_bridge_reset(pdev, option);

        pr_debug("%s: FW reset PCI bus %04x:%02x with option %d\n",
                 __func__, pci_domain_nr(pdev->bus),
                 pdev->bus->number, option);

        switch (option) {
        case EEH_RESET_FUNDAMENTAL:
                scope = OPAL_RESET_PCI_FUNDAMENTAL;
                break;
        case EEH_RESET_HOT:
                scope = OPAL_RESET_PCI_HOT;
                break;
        case EEH_RESET_DEACTIVATE:
                return 0;
        default:
                dev_dbg(&pdev->dev, "%s: Unsupported reset %d\n",
                        __func__, option);
                return -EINVAL;
        }

        rc = opal_pci_reset(id, scope, OPAL_ASSERT_RESET);
        if (rc <= OPAL_SUCCESS)
                goto out;

        rc = pnv_eeh_poll(id);
out:
        return (rc == OPAL_SUCCESS) ? 0 : -EIO;
}

void pnv_pci_reset_secondary_bus(struct pci_dev *dev)
{
        struct pci_controller *hose;

        if (pci_is_root_bus(dev->bus)) {
                hose = pci_bus_to_host(dev->bus);
                pnv_eeh_root_reset(hose, EEH_RESET_HOT);
                pnv_eeh_root_reset(hose, EEH_RESET_DEACTIVATE);
        } else {
                pnv_eeh_bridge_reset(dev, EEH_RESET_HOT);
                pnv_eeh_bridge_reset(dev, EEH_RESET_DEACTIVATE);
        }
}

static void pnv_eeh_wait_for_pending(struct pci_dn *pdn, const char *type,
                                     int pos, u16 mask)
{
        struct eeh_dev *edev = pdn->edev;
        int i, status = 0;

        /* Wait for Transaction Pending bit to be cleared */
        for (i = 0; i < 4; i++) {
                eeh_ops->read_config(edev, pos, 2, &status);
                if (!(status & mask))
                        return;

                msleep((1 << i) * 100);
        }

        pr_warn("%s: Pending transaction while issuing %sFLR to %04x:%02x:%02x.%01x\n",
                __func__, type,
                pdn->phb->global_number, pdn->busno,
                PCI_SLOT(pdn->devfn), PCI_FUNC(pdn->devfn));
}

static int pnv_eeh_do_flr(struct pci_dn *pdn, int option)
{
        struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
        u32 reg = 0;

        if (WARN_ON(!edev->pcie_cap))
                return -ENOTTY;

        eeh_ops->read_config(edev, edev->pcie_cap + PCI_EXP_DEVCAP, 4, &reg);
        if (!(reg & PCI_EXP_DEVCAP_FLR))
                return -ENOTTY;

        switch (option) {
        case EEH_RESET_HOT:
        case EEH_RESET_FUNDAMENTAL:
                pnv_eeh_wait_for_pending(pdn, "",
                                         edev->pcie_cap + PCI_EXP_DEVSTA,
                                         PCI_EXP_DEVSTA_TRPND);
                eeh_ops->read_config(edev, edev->pcie_cap + PCI_EXP_DEVCTL,
                                     4, &reg);
                reg |= PCI_EXP_DEVCTL_BCR_FLR;
                eeh_ops->write_config(edev, edev->pcie_cap + PCI_EXP_DEVCTL,
                                      4, reg);
                msleep(EEH_PE_RST_HOLD_TIME);
                break;
        case EEH_RESET_DEACTIVATE:
                eeh_ops->read_config(edev, edev->pcie_cap + PCI_EXP_DEVCTL,
                                     4, &reg);
                reg &= ~PCI_EXP_DEVCTL_BCR_FLR;
                eeh_ops->write_config(edev, edev->pcie_cap + PCI_EXP_DEVCTL,
                                      4, reg);
                msleep(EEH_PE_RST_SETTLE_TIME);
                break;
        }

        return 0;
}

static int pnv_eeh_do_af_flr(struct pci_dn *pdn, int option)
{
        struct eeh_dev *edev = pdn_to_eeh_dev(pdn);
        u32 cap = 0;

        if (WARN_ON(!edev->af_cap))
                return -ENOTTY;

        eeh_ops->read_config(edev, edev->af_cap + PCI_AF_CAP, 1, &cap);
        if (!(cap & PCI_AF_CAP_TP) || !(cap & PCI_AF_CAP_FLR))
                return -ENOTTY;

        switch (option) {
        case EEH_RESET_HOT:
        case EEH_RESET_FUNDAMENTAL:
                /*
                 * Wait for Transaction Pending bit to clear. A word-aligned
                 * test is used, so we use the control offset rather than status
                 * and shift the test bit to match.
                 */
                pnv_eeh_wait_for_pending(pdn, "AF",
                                         edev->af_cap + PCI_AF_CTRL,
                                         PCI_AF_STATUS_TP << 8);
                eeh_ops->write_config(edev, edev->af_cap + PCI_AF_CTRL,
                                      1, PCI_AF_CTRL_FLR);
                msleep(EEH_PE_RST_HOLD_TIME);
                break;
        case EEH_RESET_DEACTIVATE:
                eeh_ops->write_config(edev, edev->af_cap + PCI_AF_CTRL, 1, 0);
                msleep(EEH_PE_RST_SETTLE_TIME);
                break;
        }

        return 0;
}

static int pnv_eeh_reset_vf_pe(struct eeh_pe *pe, int option)
{
        struct eeh_dev *edev;
        struct pci_dn *pdn;
        int ret;

        /* The VF PE should have only one child device */
        edev = list_first_entry_or_null(&pe->edevs, struct eeh_dev, entry);
        pdn = eeh_dev_to_pdn(edev);
        if (!pdn)
                return -ENXIO;

        ret = pnv_eeh_do_flr(pdn, option);
        if (!ret)
                return ret;

        return pnv_eeh_do_af_flr(pdn, option);
}

/**
 * pnv_eeh_reset - Reset the specified PE
 * @pe: EEH PE
 * @option: reset option
 *
 * Do reset on the indicated PE. For PCI bus sensitive PE,
 * we need to reset the parent p2p bridge. The PHB has to
 * be reinitialized if the p2p bridge is root bridge. For
 * PCI device sensitive PE, we will try to reset the device
 * through FLR. For now, we don't have OPAL APIs to do HARD
 * reset yet, so all reset would be SOFT (HOT) reset.
 */
static int pnv_eeh_reset(struct eeh_pe *pe, int option)
{
        struct pci_controller *hose = pe->phb;
        struct pnv_phb *phb;
        struct pci_bus *bus;
        int64_t rc;

        /*
         * For PHB reset, we always have complete reset. For those PEs whose
         * primary bus derived from root complex (root bus) or root port
         * (usually bus#1), we apply hot or fundamental reset on the root port.
         * For other PEs, we always have hot reset on the PE primary bus.
         *
         * Here, we have different design to pHyp, which always clear the
         * frozen state during PE reset. However, the good idea here from
         * benh is to keep frozen state before we get PE reset done completely
         * (until BAR restore). With the frozen state, HW drops illegal IO
         * or MMIO access, which can incur recursive frozen PE during PE
         * reset. The side effect is that EEH core has to clear the frozen
         * state explicitly after BAR restore.
         */
        if (pe->type & EEH_PE_PHB)
                return pnv_eeh_phb_reset(hose, option);

        /*
         * The frozen PE might be caused by PAPR error injection
         * registers, which are expected to be cleared after hitting
         * frozen PE as stated in the hardware spec. Unfortunately,
         * that's not true on P7IOC. So we have to clear it manually
         * to avoid recursive EEH errors during recovery.
         */
        phb = hose->private_data;
        if (phb->model == PNV_PHB_MODEL_P7IOC &&
            (option == EEH_RESET_HOT ||
             option == EEH_RESET_FUNDAMENTAL)) {
                rc = opal_pci_reset(phb->opal_id,
                                    OPAL_RESET_PHB_ERROR,
                                    OPAL_ASSERT_RESET);
                if (rc != OPAL_SUCCESS) {
                        pr_warn("%s: Failure %lld clearing error injection registers\n",
                                __func__, rc);
                        return -EIO;
                }
        }

        if (pe->type & EEH_PE_VF)
                return pnv_eeh_reset_vf_pe(pe, option);

        bus = eeh_pe_bus_get(pe);
        if (!bus) {
                pr_err("%s: Cannot find PCI bus for PHB#%x-PE#%x\n",
                        __func__, pe->phb->global_number, pe->addr);
                return -EIO;
        }

        if (pci_is_root_bus(bus))
                return pnv_eeh_root_reset(hose, option);

        /*
         * For hot resets try use the generic PCI error recovery reset
         * functions. These correctly handles the case where the secondary
         * bus is behind a hotplug slot and it will use the slot provided
         * reset methods to prevent spurious hotplug events during the reset.
         *
         * Fundamental resets need to be handled internally to EEH since the
         * PCI core doesn't really have a concept of a fundamental reset,
         * mainly because there's no standard way to generate one. Only a
         * few devices require an FRESET so it should be fine.
         */
        if (option != EEH_RESET_FUNDAMENTAL) {
                /*
                 * NB: Skiboot and pnv_eeh_bridge_reset() also no-op the
                 *     de-assert step. It's like the OPAL reset API was
                 *     poorly designed or something...
                 */
                if (option == EEH_RESET_DEACTIVATE)
                        return 0;

                rc = pci_bus_error_reset(bus->self);
                if (!rc)
                        return 0;
        }

        /* otherwise, use the generic bridge reset. this might call into FW */
        if (pci_is_root_bus(bus->parent))
                return pnv_eeh_root_reset(hose, option);
        return pnv_eeh_bridge_reset(bus->self, option);
}

/**
 * pnv_eeh_get_log - Retrieve error log
 * @pe: EEH PE
 * @severity: temporary or permanent error log
 * @drv_log: driver log to be combined with retrieved error log
 * @len: length of driver log
 *
 * Retrieve the temporary or permanent error from the PE.
 */
static int pnv_eeh_get_log(struct eeh_pe *pe, int severity,
                           char *drv_log, unsigned long len)
{
        if (!eeh_has_flag(EEH_EARLY_DUMP_LOG))
                pnv_pci_dump_phb_diag_data(pe->phb, pe->data);

        return 0;
}

/**
 * pnv_eeh_configure_bridge - Configure PCI bridges in the indicated PE
 * @pe: EEH PE
 *
 * The function will be called to reconfigure the bridges included
 * in the specified PE so that the mulfunctional PE would be recovered
 * again.
 */
static int pnv_eeh_configure_bridge(struct eeh_pe *pe)
{
        return 0;
}

/**
 * pnv_pe_err_inject - Inject specified error to the indicated PE
 * @pe: the indicated PE
 * @type: error type
 * @func: specific error type
 * @addr: address
 * @mask: address mask
 *
 * The routine is called to inject specified error, which is
 * determined by @type and @func, to the indicated PE for
 * testing purpose.
 */
static int pnv_eeh_err_inject(struct eeh_pe *pe, int type, int func,
                              unsigned long addr, unsigned long mask)
{
        struct pci_controller *hose = pe->phb;
        struct pnv_phb *phb = hose->private_data;
        s64 rc;

        if (type != OPAL_ERR_INJECT_TYPE_IOA_BUS_ERR &&
            type != OPAL_ERR_INJECT_TYPE_IOA_BUS_ERR64) {
                pr_warn("%s: Invalid error type %d\n",
                        __func__, type);
                return -ERANGE;
        }

        if (func < OPAL_ERR_INJECT_FUNC_IOA_LD_MEM_ADDR ||
            func > OPAL_ERR_INJECT_FUNC_IOA_DMA_WR_TARGET) {
                pr_warn("%s: Invalid error function %d\n",
                        __func__, func);
                return -ERANGE;
        }

        /* Firmware supports error injection ? */
        if (!opal_check_token(OPAL_PCI_ERR_INJECT)) {
                pr_warn("%s: Firmware doesn't support error injection\n",
                        __func__);
                return -ENXIO;
        }

        /* Do error injection */
        rc = opal_pci_err_inject(phb->opal_id, pe->addr,
                                 type, func, addr, mask);
        if (rc != OPAL_SUCCESS) {
                pr_warn("%s: Failure %lld injecting error "
                        "%d-%d to PHB#%x-PE#%x\n",
                        __func__, rc, type, func,
                        hose->global_number, pe->addr);
                return -EIO;
        }

        return 0;
}

static inline bool pnv_eeh_cfg_blocked(struct pci_dn *pdn)
{
        struct eeh_dev *edev = pdn_to_eeh_dev(pdn);

        if (!edev || !edev->pe)
                return false;

        /*
         * We will issue FLR or AF FLR to all VFs, which are contained
         * in VF PE. It relies on the EEH PCI config accessors. So we
         * can't block them during the window.
         */
        if (edev->physfn && (edev->pe->state & EEH_PE_RESET))
                return false;

        if (edev->pe->state & EEH_PE_CFG_BLOCKED)
                return true;

        return false;
}

static int pnv_eeh_read_config(struct eeh_dev *edev,
                               int where, int size, u32 *val)
{
        struct pci_dn *pdn = eeh_dev_to_pdn(edev);

        if (!pdn)
                return PCIBIOS_DEVICE_NOT_FOUND;

        if (pnv_eeh_cfg_blocked(pdn)) {
                *val = 0xFFFFFFFF;
                return PCIBIOS_SET_FAILED;
        }

        return pnv_pci_cfg_read(pdn, where, size, val);
}

static int pnv_eeh_write_config(struct eeh_dev *edev,
                                int where, int size, u32 val)
{
        struct pci_dn *pdn = eeh_dev_to_pdn(edev);

        if (!pdn)
                return PCIBIOS_DEVICE_NOT_FOUND;

        if (pnv_eeh_cfg_blocked(pdn))
                return PCIBIOS_SET_FAILED;

        return pnv_pci_cfg_write(pdn, where, size, val);
}

static void pnv_eeh_dump_hub_diag_common(struct OpalIoP7IOCErrorData *data)
{
        /* GEM */
        if (data->gemXfir || data->gemRfir ||
            data->gemRirqfir || data->gemMask || data->gemRwof)
                pr_info("  GEM: %016llx %016llx %016llx %016llx %016llx\n",
                        be64_to_cpu(data->gemXfir),
                        be64_to_cpu(data->gemRfir),
                        be64_to_cpu(data->gemRirqfir),
                        be64_to_cpu(data->gemMask),
                        be64_to_cpu(data->gemRwof));

        /* LEM */
        if (data->lemFir || data->lemErrMask ||
            data->lemAction0 || data->lemAction1 || data->lemWof)
                pr_info("  LEM: %016llx %016llx %016llx %016llx %016llx\n",
                        be64_to_cpu(data->lemFir),
                        be64_to_cpu(data->lemErrMask),
                        be64_to_cpu(data->lemAction0),
                        be64_to_cpu(data->lemAction1),
                        be64_to_cpu(data->lemWof));
}

static void pnv_eeh_get_and_dump_hub_diag(struct pci_controller *hose)
{
        struct pnv_phb *phb = hose->private_data;
        struct OpalIoP7IOCErrorData *data =
                (struct OpalIoP7IOCErrorData*)phb->diag_data;
        long rc;

        rc = opal_pci_get_hub_diag_data(phb->hub_id, data, sizeof(*data));
        if (rc != OPAL_SUCCESS) {
                pr_warn("%s: Failed to get HUB#%llx diag-data (%ld)\n",
                        __func__, phb->hub_id, rc);
                return;
        }

        switch (be16_to_cpu(data->type)) {
        case OPAL_P7IOC_DIAG_TYPE_RGC:
                pr_info("P7IOC diag-data for RGC\n\n");
                pnv_eeh_dump_hub_diag_common(data);
                if (data->rgc.rgcStatus || data->rgc.rgcLdcp)
                        pr_info("  RGC: %016llx %016llx\n",
                                be64_to_cpu(data->rgc.rgcStatus),
                                be64_to_cpu(data->rgc.rgcLdcp));
                break;
        case OPAL_P7IOC_DIAG_TYPE_BI:
                pr_info("P7IOC diag-data for BI %s\n\n",
                        data->bi.biDownbound ? "Downbound" : "Upbound");
                pnv_eeh_dump_hub_diag_common(data);
                if (data->bi.biLdcp0 || data->bi.biLdcp1 ||
                    data->bi.biLdcp2 || data->bi.biFenceStatus)
                        pr_info("  BI:  %016llx %016llx %016llx %016llx\n",
                                be64_to_cpu(data->bi.biLdcp0),
                                be64_to_cpu(data->bi.biLdcp1),
                                be64_to_cpu(data->bi.biLdcp2),
                                be64_to_cpu(data->bi.biFenceStatus));
                break;
        case OPAL_P7IOC_DIAG_TYPE_CI:
                pr_info("P7IOC diag-data for CI Port %d\n\n",
                        data->ci.ciPort);
                pnv_eeh_dump_hub_diag_common(data);
                if (data->ci.ciPortStatus || data->ci.ciPortLdcp)
                        pr_info("  CI:  %016llx %016llx\n",
                                be64_to_cpu(data->ci.ciPortStatus),
                                be64_to_cpu(data->ci.ciPortLdcp));
                break;
        case OPAL_P7IOC_DIAG_TYPE_MISC:
                pr_info("P7IOC diag-data for MISC\n\n");
                pnv_eeh_dump_hub_diag_common(data);
                break;
        case OPAL_P7IOC_DIAG_TYPE_I2C:
                pr_info("P7IOC diag-data for I2C\n\n");
                pnv_eeh_dump_hub_diag_common(data);
                break;
        default:
                pr_warn("%s: Invalid type of HUB#%llx diag-data (%d)\n",
                        __func__, phb->hub_id, data->type);
        }
}

static int pnv_eeh_get_pe(struct pci_controller *hose,
                          u16 pe_no, struct eeh_pe **pe)
{
        struct pnv_phb *phb = hose->private_data;
        struct pnv_ioda_pe *pnv_pe;
        struct eeh_pe *dev_pe;

        /*
         * If PHB supports compound PE, to fetch
         * the master PE because slave PE is invisible
         * to EEH core.
         */
        pnv_pe = &phb->ioda.pe_array[pe_no];
        if (pnv_pe->flags & PNV_IODA_PE_SLAVE) {
                pnv_pe = pnv_pe->master;
                WARN_ON(!pnv_pe ||
                        !(pnv_pe->flags & PNV_IODA_PE_MASTER));
                pe_no = pnv_pe->pe_number;
        }

        /* Find the PE according to PE# */
        dev_pe = eeh_pe_get(hose, pe_no);
        if (!dev_pe)
                return -EEXIST;

        /* Freeze the (compound) PE */
        *pe = dev_pe;
        if (!(dev_pe->state & EEH_PE_ISOLATED))
                phb->freeze_pe(phb, pe_no);

        /*
         * At this point, we're sure the (compound) PE should
         * have been frozen. However, we still need poke until
         * hitting the frozen PE on top level.
         */
        dev_pe = dev_pe->parent;
        while (dev_pe && !(dev_pe->type & EEH_PE_PHB)) {
                int ret;
                ret = eeh_ops->get_state(dev_pe, NULL);
                if (ret <= 0 || eeh_state_active(ret)) {
                        dev_pe = dev_pe->parent;
                        continue;
                }

                /* Frozen parent PE */
                *pe = dev_pe;
                if (!(dev_pe->state & EEH_PE_ISOLATED))
                        phb->freeze_pe(phb, dev_pe->addr);

                /* Next one */
                dev_pe = dev_pe->parent;
        }

        return 0;
}

/**
 * pnv_eeh_next_error - Retrieve next EEH error to handle
 * @pe: Affected PE
 *
 * The function is expected to be called by EEH core while it gets
 * special EEH event (without binding PE). The function calls to
 * OPAL APIs for next error to handle. The informational error is
 * handled internally by platform. However, the dead IOC, dead PHB,
 * fenced PHB and frozen PE should be handled by EEH core eventually.
 */
static int pnv_eeh_next_error(struct eeh_pe **pe)
{
        struct pci_controller *hose;
        struct pnv_phb *phb;
        struct eeh_pe *phb_pe, *parent_pe;
        __be64 frozen_pe_no;
        __be16 err_type, severity;
        long rc;
        int state, ret = EEH_NEXT_ERR_NONE;

        /*
         * While running here, it's safe to purge the event queue. The
         * event should still be masked.
         */
        eeh_remove_event(NULL, false);

        list_for_each_entry(hose, &hose_list, list_node) {
                /*
                 * If the subordinate PCI buses of the PHB has been
                 * removed or is exactly under error recovery, we
                 * needn't take care of it any more.
                 */
                phb = hose->private_data;
                phb_pe = eeh_phb_pe_get(hose);
                if (!phb_pe || (phb_pe->state & EEH_PE_ISOLATED))
                        continue;

                rc = opal_pci_next_error(phb->opal_id,
                                         &frozen_pe_no, &err_type, &severity);
                if (rc != OPAL_SUCCESS) {
                        pr_devel("%s: Invalid return value on "
                                 "PHB#%x (0x%lx) from opal_pci_next_error",
                                 __func__, hose->global_number, rc);
                        continue;
                }

                /* If the PHB doesn't have error, stop processing */
                if (be16_to_cpu(err_type) == OPAL_EEH_NO_ERROR ||
                    be16_to_cpu(severity) == OPAL_EEH_SEV_NO_ERROR) {
                        pr_devel("%s: No error found on PHB#%x\n",
                                 __func__, hose->global_number);
                        continue;
                }

                /*
                 * Processing the error. We're expecting the error with
                 * highest priority reported upon multiple errors on the
                 * specific PHB.
                 */
                pr_devel("%s: Error (%d, %d, %llu) on PHB#%x\n",
                        __func__, be16_to_cpu(err_type),
                        be16_to_cpu(severity), be64_to_cpu(frozen_pe_no),
                        hose->global_number);
                switch (be16_to_cpu(err_type)) {
                case OPAL_EEH_IOC_ERROR:
                        if (be16_to_cpu(severity) == OPAL_EEH_SEV_IOC_DEAD) {
                                pr_err("EEH: dead IOC detected\n");
                                ret = EEH_NEXT_ERR_DEAD_IOC;
                        } else if (be16_to_cpu(severity) == OPAL_EEH_SEV_INF) {
                                pr_info("EEH: IOC informative error "
                                        "detected\n");
                                pnv_eeh_get_and_dump_hub_diag(hose);
                                ret = EEH_NEXT_ERR_NONE;
                        }

                        break;
                case OPAL_EEH_PHB_ERROR:
                        if (be16_to_cpu(severity) == OPAL_EEH_SEV_PHB_DEAD) {
                                *pe = phb_pe;
                                pr_err("EEH: dead PHB#%x detected, "
                                       "location: %s\n",
                                        hose->global_number,
                                        eeh_pe_loc_get(phb_pe));
                                ret = EEH_NEXT_ERR_DEAD_PHB;
                        } else if (be16_to_cpu(severity) ==
                                   OPAL_EEH_SEV_PHB_FENCED) {
                                *pe = phb_pe;
                                pr_err("EEH: Fenced PHB#%x detected, "
                                       "location: %s\n",
                                        hose->global_number,
                                        eeh_pe_loc_get(phb_pe));
                                ret = EEH_NEXT_ERR_FENCED_PHB;
                        } else if (be16_to_cpu(severity) == OPAL_EEH_SEV_INF) {
                                pr_info("EEH: PHB#%x informative error "
                                        "detected, location: %s\n",
                                        hose->global_number,
                                        eeh_pe_loc_get(phb_pe));
                                pnv_eeh_get_phb_diag(phb_pe);
                                pnv_pci_dump_phb_diag_data(hose, phb_pe->data);
                                ret = EEH_NEXT_ERR_NONE;
                        }

                        break;
                case OPAL_EEH_PE_ERROR:
                        /*
                         * If we can't find the corresponding PE, we
                         * just try to unfreeze.
                         */
                        if (pnv_eeh_get_pe(hose,
                                be64_to_cpu(frozen_pe_no), pe)) {
                                pr_info("EEH: Clear non-existing PHB#%x-PE#%llx\n",
                                        hose->global_number, be64_to_cpu(frozen_pe_no));
                                pr_info("EEH: PHB location: %s\n",
                                        eeh_pe_loc_get(phb_pe));

                                /* Dump PHB diag-data */
                                rc = opal_pci_get_phb_diag_data2(phb->opal_id,
                                        phb->diag_data, phb->diag_data_size);
                                if (rc == OPAL_SUCCESS)
                                        pnv_pci_dump_phb_diag_data(hose,
                                                        phb->diag_data);

                                /* Try best to clear it */
                                opal_pci_eeh_freeze_clear(phb->opal_id,
                                        be64_to_cpu(frozen_pe_no),
                                        OPAL_EEH_ACTION_CLEAR_FREEZE_ALL);
                                ret = EEH_NEXT_ERR_NONE;
                        } else if ((*pe)->state & EEH_PE_ISOLATED ||
                                   eeh_pe_passed(*pe)) {
                                ret = EEH_NEXT_ERR_NONE;
                        } else {
                                pr_err("EEH: Frozen PE#%x "
                                       "on PHB#%x detected\n",
                                       (*pe)->addr,
                                        (*pe)->phb->global_number);
                                pr_err("EEH: PE location: %s, "
                                       "PHB location: %s\n",
                                       eeh_pe_loc_get(*pe),
                                       eeh_pe_loc_get(phb_pe));
                                ret = EEH_NEXT_ERR_FROZEN_PE;
                        }

                        break;
                default:
                        pr_warn("%s: Unexpected error type %d\n",
                                __func__, be16_to_cpu(err_type));
                }

                /*
                 * EEH core will try recover from fenced PHB or
                 * frozen PE. In the time for frozen PE, EEH core
                 * enable IO path for that before collecting logs,
                 * but it ruins the site. So we have to dump the
                 * log in advance here.
                 */
                if ((ret == EEH_NEXT_ERR_FROZEN_PE  ||
                    ret == EEH_NEXT_ERR_FENCED_PHB) &&
                    !((*pe)->state & EEH_PE_ISOLATED)) {
                        eeh_pe_mark_isolated(*pe);
                        pnv_eeh_get_phb_diag(*pe);

                        if (eeh_has_flag(EEH_EARLY_DUMP_LOG))
                                pnv_pci_dump_phb_diag_data((*pe)->phb,
                                                           (*pe)->data);
                }

                /*
                 * We probably have the frozen parent PE out there and
                 * we need have to handle frozen parent PE firstly.
                 */
                if (ret == EEH_NEXT_ERR_FROZEN_PE) {
                        parent_pe = (*pe)->parent;
                        while (parent_pe) {
                                /* Hit the ceiling ? */
                                if (parent_pe->type & EEH_PE_PHB)
                                        break;

                                /* Frozen parent PE ? */
                                state = eeh_ops->get_state(parent_pe, NULL);
                                if (state > 0 && !eeh_state_active(state))
                                        *pe = parent_pe;

                                /* Next parent level */
                                parent_pe = parent_pe->parent;
                        }

                        /* We possibly migrate to another PE */
                        eeh_pe_mark_isolated(*pe);
                }

                /*
                 * If we have no errors on the specific PHB or only
                 * informative error there, we continue poking it.
                 * Otherwise, we need actions to be taken by upper
                 * layer.
                 */
                if (ret > EEH_NEXT_ERR_INF)
                        break;
        }

        /* Unmask the event */
        if (ret == EEH_NEXT_ERR_NONE && eeh_enabled())
                enable_irq(eeh_event_irq);

        return ret;
}

static int pnv_eeh_restore_config(struct eeh_dev *edev)
{
        struct pnv_phb *phb;
        s64 ret = 0;

        if (!edev)
                return -EEXIST;

        if (edev->physfn)
                return 0;

        phb = edev->controller->private_data;
        ret = opal_pci_reinit(phb->opal_id,
                              OPAL_REINIT_PCI_DEV, edev->bdfn);

        if (ret) {
                pr_warn("%s: Can't reinit PCI dev 0x%x (%lld)\n",
                        __func__, edev->bdfn, ret);
                return -EIO;
        }

        return ret;
}

static struct eeh_ops pnv_eeh_ops = {
        .name                   = "powernv",
        .probe                  = pnv_eeh_probe,
        .set_option             = pnv_eeh_set_option,
        .get_state              = pnv_eeh_get_state,
        .reset                  = pnv_eeh_reset,
        .get_log                = pnv_eeh_get_log,
        .configure_bridge       = pnv_eeh_configure_bridge,
        .err_inject             = pnv_eeh_err_inject,
        .read_config            = pnv_eeh_read_config,
        .write_config           = pnv_eeh_write_config,
        .next_error             = pnv_eeh_next_error,
        .restore_config         = pnv_eeh_restore_config,
        .notify_resume          = NULL
};

/**
 * eeh_powernv_init - Register platform dependent EEH operations
 *
 * EEH initialization on powernv platform. This function should be
 * called before any EEH related functions.
 */
static int __init eeh_powernv_init(void)
{
        int max_diag_size = PNV_PCI_DIAG_BUF_SIZE;
        struct pci_controller *hose;
        struct pnv_phb *phb;
        int ret = -EINVAL;

        if (!firmware_has_feature(FW_FEATURE_OPAL)) {
                pr_warn("%s: OPAL is required !\n", __func__);
                return -EINVAL;
        }

        /* Set probe mode */
        eeh_add_flag(EEH_PROBE_MODE_DEV);

        /*
         * P7IOC blocks PCI config access to frozen PE, but PHB3
         * doesn't do that. So we have to selectively enable I/O
         * prior to collecting error log.
         */
        list_for_each_entry(hose, &hose_list, list_node) {
                phb = hose->private_data;

                if (phb->model == PNV_PHB_MODEL_P7IOC)
                        eeh_add_flag(EEH_ENABLE_IO_FOR_LOG);

                if (phb->diag_data_size > max_diag_size)
                        max_diag_size = phb->diag_data_size;

                break;
        }

        /*
         * eeh_init() allocates the eeh_pe and its aux data buf so the
         * size needs to be set before calling eeh_init().
         */
        eeh_set_pe_aux_size(max_diag_size);
        ppc_md.pcibios_bus_add_device = pnv_pcibios_bus_add_device;

        ret = eeh_init(&pnv_eeh_ops);
        if (!ret)
                pr_info("EEH: PowerNV platform initialized\n");
        else
                pr_info("EEH: Failed to initialize PowerNV platform (%d)\n", ret);

        return ret;
}
machine_arch_initcall(powernv, eeh_powernv_init);