/*
 * The file intends to implement the functions needed by EEH, which is
 * built on IODA compliant chip. Actually, lots of functions related
 * to EEH would be built based on the OPAL APIs.
 *
 * Copyright Benjamin Herrenschmidt & Gavin Shan, IBM Corporation 2013.
 *
 * 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.
 */

#include <linux/bootmem.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/msi.h>
#include <linux/notifier.h>
#include <linux/pci.h>
#include <linux/string.h>

#include <asm/eeh.h>
#include <asm/eeh_event.h>
#include <asm/io.h>
#include <asm/iommu.h>
#include <asm/msi_bitmap.h>
#include <asm/opal.h>
#include <asm/pci-bridge.h>
#include <asm/ppc-pci.h>
#include <asm/tce.h>

#include "powernv.h"
#include "pci.h"

static int ioda_eeh_nb_init = 0;

static int ioda_eeh_event(struct notifier_block *nb,
			  unsigned long events, void *change)
{
	uint64_t changed_evts = (uint64_t)change;

	/*
	 * We simply send special EEH event if EEH has
	 * been enabled, or clear pending events in
	 * case that we enable EEH soon
	 */
	if (!(changed_evts & OPAL_EVENT_PCI_ERROR) ||
	    !(events & OPAL_EVENT_PCI_ERROR))
		return 0;

	if (eeh_enabled())
		eeh_send_failure_event(NULL);
	else
		opal_notifier_update_evt(OPAL_EVENT_PCI_ERROR, 0x0ul);

	return 0;
}

static struct notifier_block ioda_eeh_nb = {
	.notifier_call	= ioda_eeh_event,
	.next		= NULL,
	.priority	= 0
};

#ifdef CONFIG_DEBUG_FS
static ssize_t ioda_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 pnv_phb *phb = hose->private_data;
	struct eeh_dev *edev;
	struct eeh_pe *pe;
	int pe_no, type, func;
	unsigned long addr, mask;
	char buf[50];
	int ret;

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

	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 */
	edev = kzalloc(sizeof(*edev), GFP_KERNEL);
	if (!edev)
		return -ENOMEM;
	edev->phb = hose;
	edev->pe_config_addr = pe_no;
	pe = eeh_pe_get(edev);
	kfree(edev);
	if (!pe)
		return -ENODEV;

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

static const struct file_operations ioda_eeh_ei_fops = {
	.open   = simple_open,
	.llseek = no_llseek,
	.write  = ioda_eeh_ei_write,
};

static int ioda_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 ioda_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;
}

static int ioda_eeh_outb_dbgfs_set(void *data, u64 val)
{
	return ioda_eeh_dbgfs_set(data, 0xD10, val);
}

static int ioda_eeh_outb_dbgfs_get(void *data, u64 *val)
{
	return ioda_eeh_dbgfs_get(data, 0xD10, val);
}

static int ioda_eeh_inbA_dbgfs_set(void *data, u64 val)
{
	return ioda_eeh_dbgfs_set(data, 0xD90, val);
}

static int ioda_eeh_inbA_dbgfs_get(void *data, u64 *val)
{
	return ioda_eeh_dbgfs_get(data, 0xD90, val);
}

static int ioda_eeh_inbB_dbgfs_set(void *data, u64 val)
{
	return ioda_eeh_dbgfs_set(data, 0xE10, val);
}

static int ioda_eeh_inbB_dbgfs_get(void *data, u64 *val)
{
	return ioda_eeh_dbgfs_get(data, 0xE10, val);
}

DEFINE_SIMPLE_ATTRIBUTE(ioda_eeh_outb_dbgfs_ops, ioda_eeh_outb_dbgfs_get,
			ioda_eeh_outb_dbgfs_set, "0x%llx\n");
DEFINE_SIMPLE_ATTRIBUTE(ioda_eeh_inbA_dbgfs_ops, ioda_eeh_inbA_dbgfs_get,
			ioda_eeh_inbA_dbgfs_set, "0x%llx\n");
DEFINE_SIMPLE_ATTRIBUTE(ioda_eeh_inbB_dbgfs_ops, ioda_eeh_inbB_dbgfs_get,
			ioda_eeh_inbB_dbgfs_set, "0x%llx\n");
#endif /* CONFIG_DEBUG_FS */


/**
 * ioda_eeh_post_init - Chip dependent post initialization
 * @hose: PCI controller
 *
 * The function will be called after eeh PEs and devices
 * have been built. That means the EEH is ready to supply
 * service with I/O cache.
 */
static int ioda_eeh_post_init(struct pci_controller *hose)
{
	struct pnv_phb *phb = hose->private_data;
	int ret;

	/* Register OPAL event notifier */
	if (!ioda_eeh_nb_init) {
		ret = opal_notifier_register(&ioda_eeh_nb);
		if (ret) {
			pr_err("%s: Can't register OPAL event notifier (%d)\n",
			       __func__, ret);
			return ret;
		}

		ioda_eeh_nb_init = 1;
	}

#ifdef CONFIG_DEBUG_FS
	if (!phb->has_dbgfs && phb->dbgfs) {
		phb->has_dbgfs = 1;

		debugfs_create_file("err_injct", 0200,
				    phb->dbgfs, hose,
				    &ioda_eeh_ei_fops);

		debugfs_create_file("err_injct_outbound", 0600,
				    phb->dbgfs, hose,
				    &ioda_eeh_outb_dbgfs_ops);
		debugfs_create_file("err_injct_inboundA", 0600,
				    phb->dbgfs, hose,
				    &ioda_eeh_inbA_dbgfs_ops);
		debugfs_create_file("err_injct_inboundB", 0600,
				    phb->dbgfs, hose,
				    &ioda_eeh_inbB_dbgfs_ops);
	}
#endif

	/* 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;

	return 0;
}

/**
 * ioda_eeh_set_option - Set EEH operation or I/O setting
 * @pe: EEH PE
 * @option: options
 *
 * Enable or disable EEH option for the indicated PE. The
 * function also can be used to enable I/O or DMA for the
 * PE.
 */
static int ioda_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 enable, ret = 0;
	s64 rc;

	/* Check on PE number */
	if (pe->addr < 0 || pe->addr >= phb->ioda.total_pe) {
		pr_err("%s: PE address %x out of range [0, %x] "
		       "on PHB#%x\n",
			__func__, pe->addr, phb->ioda.total_pe,
			hose->global_number);
		return -EINVAL;
	}

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

	/* If PHB supports compound PE, to handle it */
	if (freeze_pe) {
		if (phb->freeze_pe) {
			phb->freeze_pe(phb, pe->addr);
		} else {
			rc = opal_pci_eeh_freeze_set(phb->opal_id,
						     pe->addr,
						     enable);
			if (rc != OPAL_SUCCESS) {
				pr_warn("%s: Failure %lld freezing "
					"PHB#%x-PE#%x\n",
					__func__, rc,
					phb->hose->global_number, pe->addr);
				ret = -EIO;
			}
		}
	} else {
		if (phb->unfreeze_pe) {
			ret = phb->unfreeze_pe(phb, pe->addr, enable);
		} else {
			rc = opal_pci_eeh_freeze_clear(phb->opal_id,
						       pe->addr,
						       enable);
			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);
				ret = -EIO;
			}
		}
	}

	return ret;
}

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

	rc = opal_pci_get_phb_diag_data2(phb->opal_id, pe->data,
					 PNV_PCI_DIAG_BUF_SIZE);
	if (rc != OPAL_SUCCESS)
		pr_warn("%s: Failed to get diag-data for PHB#%x (%ld)\n",
			__func__, pe->phb->global_number, rc);
}

static int ioda_eeh_get_phb_state(struct eeh_pe *pe)
{
	struct pnv_phb *phb = pe->phb->private_data;
	u8 fstate;
	__be16 pcierr;
	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_state_mark(pe, EEH_PE_ISOLATED);
		ioda_eeh_phb_diag(pe);
	}

	return result;
}

static int ioda_eeh_get_pe_state(struct eeh_pe *pe)
{
	struct pnv_phb *phb = pe->phb->private_data;
	u8 fstate;
	__be16 pcierr;
	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_CFG_BLOCKED) {
		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_state_mark(pe, EEH_PE_ISOLATED);
		ioda_eeh_phb_diag(pe);
	}

	return result;
}

/**
 * ioda_eeh_get_state - Retrieve the state of PE
 * @pe: EEH PE
 *
 * The PE's state should be retrieved from the PEEV, PEST
 * IODA tables. Since the OPAL has exported the function
 * to do it, it'd better to use that.
 */
static int ioda_eeh_get_state(struct eeh_pe *pe)
{
	struct pnv_phb *phb = pe->phb->private_data;

	/* Sanity check on PE number. PHB PE should have 0 */
	if (pe->addr < 0 ||
	    pe->addr >= phb->ioda.total_pe) {
		pr_warn("%s: PHB#%x-PE#%x out of range [0, %x]\n",
			__func__, phb->hose->global_number,
			pe->addr, phb->ioda.total_pe);
		return EEH_STATE_NOT_SUPPORT;
	}

	if (pe->type & EEH_PE_PHB)
		return ioda_eeh_get_phb_state(pe);

	return ioda_eeh_get_pe_state(pe);
}

static s64 ioda_eeh_phb_poll(struct pnv_phb *phb)
{
	s64 rc = OPAL_HARDWARE;

	while (1) {
		rc = opal_pci_poll(phb->opal_id);
		if (rc <= 0)
			break;

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

	return rc;
}

int ioda_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.
	 */
	rc = ioda_eeh_phb_poll(phb);
	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 ioda_eeh_root_reset(struct pci_controller *hose, int option)
{
	struct pnv_phb *phb = hose->private_data;
	s64 rc = OPAL_SUCCESS;

	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 */
	rc = ioda_eeh_phb_poll(phb);
	if (option == EEH_RESET_DEACTIVATE)
		msleep(EEH_PE_RST_SETTLE_TIME);
out:
	if (rc != OPAL_SUCCESS)
		return -EIO;

	return 0;
}

static int ioda_eeh_bridge_reset(struct pci_dev *dev, int option)

{
	struct device_node *dn = pci_device_to_OF_node(dev);
	struct eeh_dev *edev = of_node_to_eeh_dev(dn);
	int aer = edev ? edev->aer_cap : 0;
	u32 ctrl;

	pr_debug("%s: 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(dn, aer + PCI_ERR_UNCOR_MASK,
					     4, &ctrl);
			ctrl |= PCI_ERR_UNC_SURPDN;
                        eeh_ops->write_config(dn, aer + PCI_ERR_UNCOR_MASK,
					      4, ctrl);
                }

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

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

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

		break;
	}

	return 0;
}

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);
		ioda_eeh_root_reset(hose, EEH_RESET_HOT);
		ioda_eeh_root_reset(hose, EEH_RESET_DEACTIVATE);
	} else {
		ioda_eeh_bridge_reset(dev, EEH_RESET_HOT);
		ioda_eeh_bridge_reset(dev, EEH_RESET_DEACTIVATE);
	}
}

/**
 * ioda_eeh_reset - Reset the indicated 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 ioda_eeh_reset(struct eeh_pe *pe, int option)
{
	struct pci_controller *hose = pe->phb;
	struct pci_bus *bus;
	int ret;

	/*
	 * 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 recrusive 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) {
		ret = ioda_eeh_phb_reset(hose, option);
	} else {
		struct pnv_phb *phb;
		s64 rc;

		/*
		 * 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;
			}
		}

		bus = eeh_pe_bus_get(pe);
		if (pci_is_root_bus(bus) ||
		    pci_is_root_bus(bus->parent))
			ret = ioda_eeh_root_reset(hose, option);
		else
			ret = ioda_eeh_bridge_reset(bus->self, option);
	}

	return ret;
}

/**
 * ioda_eeh_get_log - Retrieve error log
 * @pe: frozen PE
 * @severity: permanent or temporary error
 * @drv_log: device driver log
 * @len: length of device driver log
 *
 * Retrieve error log, which contains log from device driver
 * and firmware.
 */
static int ioda_eeh_get_log(struct eeh_pe *pe, int severity,
			    char *drv_log, unsigned long len)
{
	pnv_pci_dump_phb_diag_data(pe->phb, pe->data);

	return 0;
}

/**
 * ioda_eeh_configure_bridge - Configure the PCI bridges for the indicated PE
 * @pe: EEH PE
 *
 * For particular PE, it might have included PCI bridges. In order
 * to make the PE work properly, those PCI bridges should be configured
 * correctly. However, we need do nothing on P7IOC since the reset
 * function will do everything that should be covered by the function.
 */
static int ioda_eeh_configure_bridge(struct eeh_pe *pe)
{
	return 0;
}

static int ioda_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 ret;

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

	return 0;
}

static void ioda_eeh_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 ioda_eeh_hub_diag(struct pci_controller *hose)
{
	struct pnv_phb *phb = hose->private_data;
	struct OpalIoP7IOCErrorData *data = &phb->diag.hub_diag;
	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 (data->type) {
	case OPAL_P7IOC_DIAG_TYPE_RGC:
		pr_info("P7IOC diag-data for RGC\n\n");
		ioda_eeh_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");
		ioda_eeh_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);
		ioda_eeh_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");
		ioda_eeh_hub_diag_common(data);
		break;
	case OPAL_P7IOC_DIAG_TYPE_I2C:
		pr_info("P7IOC diag-data for I2C\n\n");
		ioda_eeh_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 ioda_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;
	struct eeh_dev edev;

	/*
	 * 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# */
	memset(&edev, 0, sizeof(struct eeh_dev));
	edev.phb = hose;
	edev.pe_config_addr = pe_no;
	dev_pe = eeh_pe_get(&edev);
	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;
		int active_flags = (EEH_STATE_MMIO_ACTIVE |
				    EEH_STATE_DMA_ACTIVE);

		ret = eeh_ops->get_state(dev_pe, NULL);
		if (ret <= 0 || (ret & active_flags) == active_flags) {
			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;
}

/**
 * ioda_eeh_next_error - Retrieve next error for EEH core to handle
 * @pe: The 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 ioda_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;
	int active_flags = (EEH_STATE_MMIO_ACTIVE | EEH_STATE_DMA_ACTIVE);
	long rc;
	int state, ret = EEH_NEXT_ERR_NONE;

	/*
	 * While running here, it's safe to purge the event queue.
	 * And we should keep the cached OPAL notifier event sychronized
	 * between the kernel and firmware.
	 */
	eeh_remove_event(NULL, false);
	opal_notifier_update_evt(OPAL_EVENT_PCI_ERROR, 0x0ul);

	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 OPAL API returns error, we needn't proceed */
		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");
				ioda_eeh_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));
				ioda_eeh_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 (ioda_eeh_get_pe(hose,
					    be64_to_cpu(frozen_pe_no), pe)) {
				/* Try best to clear it */
				pr_info("EEH: Clear non-existing PHB#%x-PE#%llx\n",
					hose->global_number, frozen_pe_no);
				pr_info("EEH: PHB location: %s\n",
					eeh_pe_loc_get(phb_pe));
				opal_pci_eeh_freeze_clear(phb->opal_id, 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_state_mark(*pe, EEH_PE_ISOLATED);
			ioda_eeh_phb_diag(*pe);
		}

		/*
		 * 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 = ioda_eeh_get_state(parent_pe);
				if (state > 0 &&
				    (state & active_flags) != active_flags)
					*pe = parent_pe;

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

			/* We possibly migrate to another PE */
			eeh_pe_state_mark(*pe, EEH_PE_ISOLATED);
		}

		/*
		 * 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;
	}

	return ret;
}

struct pnv_eeh_ops ioda_eeh_ops = {
	.post_init		= ioda_eeh_post_init,
	.set_option		= ioda_eeh_set_option,
	.get_state		= ioda_eeh_get_state,
	.reset			= ioda_eeh_reset,
	.get_log		= ioda_eeh_get_log,
	.configure_bridge	= ioda_eeh_configure_bridge,
	.err_inject		= ioda_eeh_err_inject,
	.next_error		= ioda_eeh_next_error
};