/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 *   redistributing this file, you may do so under either license.
 *
 *   GPL LICENSE SUMMARY
 *
 *   Copyright(c) 2012 Intel Corporation. All rights reserved.
 *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of version 2 of the GNU General Public License as
 *   published by the Free Software Foundation.
 *
 *   BSD LICENSE
 *
 *   Copyright(c) 2012 Intel Corporation. All rights reserved.
 *   Copyright (C) 2015 EMC Corporation. All Rights Reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copy
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Intel Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Intel PCIe NTB Linux driver
 *
 * Contact Information:
 * Jon Mason <jon.mason@intel.com>
 */

#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/ntb.h>

#include "ntb_hw_intel.h"

#define NTB_NAME        "ntb_hw_intel"
#define NTB_DESC        "Intel(R) PCI-E Non-Transparent Bridge Driver"
#define NTB_VER         "2.0"

MODULE_DESCRIPTION(NTB_DESC);
MODULE_VERSION(NTB_VER);
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Intel Corporation");

#define bar0_off(base, bar) ((base) + ((bar) << 2))
#define bar2_off(base, bar) bar0_off(base, (bar) - 2)

static const struct intel_ntb_reg atom_reg;
static const struct intel_ntb_alt_reg atom_pri_reg;
static const struct intel_ntb_alt_reg atom_sec_reg;
static const struct intel_ntb_alt_reg atom_b2b_reg;
static const struct intel_ntb_xlat_reg atom_pri_xlat;
static const struct intel_ntb_xlat_reg atom_sec_xlat;
static const struct intel_ntb_reg xeon_reg;
static const struct intel_ntb_alt_reg xeon_pri_reg;
static const struct intel_ntb_alt_reg xeon_sec_reg;
static const struct intel_ntb_alt_reg xeon_b2b_reg;
static const struct intel_ntb_xlat_reg xeon_pri_xlat;
static const struct intel_ntb_xlat_reg xeon_sec_xlat;
static struct intel_b2b_addr xeon_b2b_usd_addr;
static struct intel_b2b_addr xeon_b2b_dsd_addr;
static const struct intel_ntb_reg skx_reg;
static const struct intel_ntb_alt_reg skx_pri_reg;
static const struct intel_ntb_alt_reg skx_b2b_reg;
static const struct intel_ntb_xlat_reg skx_sec_xlat;
static const struct ntb_dev_ops intel_ntb_ops;
static const struct ntb_dev_ops intel_ntb3_ops;

static const struct file_operations intel_ntb_debugfs_info;
static struct dentry *debugfs_dir;

static int b2b_mw_idx = -1;
module_param(b2b_mw_idx, int, 0644);
MODULE_PARM_DESC(b2b_mw_idx, "Use this mw idx to access the peer ntb.  A "
                 "value of zero or positive starts from first mw idx, and a "
                 "negative value starts from last mw idx.  Both sides MUST "
                 "set the same value here!");

static unsigned int b2b_mw_share;
module_param(b2b_mw_share, uint, 0644);
MODULE_PARM_DESC(b2b_mw_share, "If the b2b mw is large enough, configure the "
                 "ntb so that the peer ntb only occupies the first half of "
                 "the mw, so the second half can still be used as a mw.  Both "
                 "sides MUST set the same value here!");

module_param_named(xeon_b2b_usd_bar2_addr64,
                   xeon_b2b_usd_addr.bar2_addr64, ullong, 0644);
MODULE_PARM_DESC(xeon_b2b_usd_bar2_addr64,
                 "XEON B2B USD BAR 2 64-bit address");

module_param_named(xeon_b2b_usd_bar4_addr64,
                   xeon_b2b_usd_addr.bar4_addr64, ullong, 0644);
MODULE_PARM_DESC(xeon_b2b_usd_bar4_addr64,
                 "XEON B2B USD BAR 4 64-bit address");

module_param_named(xeon_b2b_usd_bar4_addr32,
                   xeon_b2b_usd_addr.bar4_addr32, ullong, 0644);
MODULE_PARM_DESC(xeon_b2b_usd_bar4_addr32,
                 "XEON B2B USD split-BAR 4 32-bit address");

module_param_named(xeon_b2b_usd_bar5_addr32,
                   xeon_b2b_usd_addr.bar5_addr32, ullong, 0644);
MODULE_PARM_DESC(xeon_b2b_usd_bar5_addr32,
                 "XEON B2B USD split-BAR 5 32-bit address");

module_param_named(xeon_b2b_dsd_bar2_addr64,
                   xeon_b2b_dsd_addr.bar2_addr64, ullong, 0644);
MODULE_PARM_DESC(xeon_b2b_dsd_bar2_addr64,
                 "XEON B2B DSD BAR 2 64-bit address");

module_param_named(xeon_b2b_dsd_bar4_addr64,
                   xeon_b2b_dsd_addr.bar4_addr64, ullong, 0644);
MODULE_PARM_DESC(xeon_b2b_dsd_bar4_addr64,
                 "XEON B2B DSD BAR 4 64-bit address");

module_param_named(xeon_b2b_dsd_bar4_addr32,
                   xeon_b2b_dsd_addr.bar4_addr32, ullong, 0644);
MODULE_PARM_DESC(xeon_b2b_dsd_bar4_addr32,
                 "XEON B2B DSD split-BAR 4 32-bit address");

module_param_named(xeon_b2b_dsd_bar5_addr32,
                   xeon_b2b_dsd_addr.bar5_addr32, ullong, 0644);
MODULE_PARM_DESC(xeon_b2b_dsd_bar5_addr32,
                 "XEON B2B DSD split-BAR 5 32-bit address");

static inline enum ntb_topo xeon_ppd_topo(struct intel_ntb_dev *ndev, u8 ppd);
static int xeon_init_isr(struct intel_ntb_dev *ndev);

#ifndef ioread64
#ifdef readq
#define ioread64 readq
#else
#define ioread64 _ioread64
static inline u64 _ioread64(void __iomem *mmio)
{
        u64 low, high;

        low = ioread32(mmio);
        high = ioread32(mmio + sizeof(u32));
        return low | (high << 32);
}
#endif
#endif

#ifndef iowrite64
#ifdef writeq
#define iowrite64 writeq
#else
#define iowrite64 _iowrite64
static inline void _iowrite64(u64 val, void __iomem *mmio)
{
        iowrite32(val, mmio);
        iowrite32(val >> 32, mmio + sizeof(u32));
}
#endif
#endif

static inline int pdev_is_atom(struct pci_dev *pdev)
{
        switch (pdev->device) {
        case PCI_DEVICE_ID_INTEL_NTB_B2B_BWD:
                return 1;
        }
        return 0;
}

static inline int pdev_is_xeon(struct pci_dev *pdev)
{
        switch (pdev->device) {
        case PCI_DEVICE_ID_INTEL_NTB_SS_JSF:
        case PCI_DEVICE_ID_INTEL_NTB_SS_SNB:
        case PCI_DEVICE_ID_INTEL_NTB_SS_IVT:
        case PCI_DEVICE_ID_INTEL_NTB_SS_HSX:
        case PCI_DEVICE_ID_INTEL_NTB_SS_BDX:
        case PCI_DEVICE_ID_INTEL_NTB_PS_JSF:
        case PCI_DEVICE_ID_INTEL_NTB_PS_SNB:
        case PCI_DEVICE_ID_INTEL_NTB_PS_IVT:
        case PCI_DEVICE_ID_INTEL_NTB_PS_HSX:
        case PCI_DEVICE_ID_INTEL_NTB_PS_BDX:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_JSF:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_SNB:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_IVT:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_HSX:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_BDX:
                return 1;
        }
        return 0;
}

static inline int pdev_is_skx_xeon(struct pci_dev *pdev)
{
        if (pdev->device == PCI_DEVICE_ID_INTEL_NTB_B2B_SKX)
                return 1;

        return 0;
}

static inline void ndev_reset_unsafe_flags(struct intel_ntb_dev *ndev)
{
        ndev->unsafe_flags = 0;
        ndev->unsafe_flags_ignore = 0;

        /* Only B2B has a workaround to avoid SDOORBELL */
        if (ndev->hwerr_flags & NTB_HWERR_SDOORBELL_LOCKUP)
                if (!ntb_topo_is_b2b(ndev->ntb.topo))
                        ndev->unsafe_flags |= NTB_UNSAFE_DB;

        /* No low level workaround to avoid SB01BASE */
        if (ndev->hwerr_flags & NTB_HWERR_SB01BASE_LOCKUP) {
                ndev->unsafe_flags |= NTB_UNSAFE_DB;
                ndev->unsafe_flags |= NTB_UNSAFE_SPAD;
        }
}

static inline int ndev_is_unsafe(struct intel_ntb_dev *ndev,
                                 unsigned long flag)
{
        return !!(flag & ndev->unsafe_flags & ~ndev->unsafe_flags_ignore);
}

static inline int ndev_ignore_unsafe(struct intel_ntb_dev *ndev,
                                     unsigned long flag)
{
        flag &= ndev->unsafe_flags;
        ndev->unsafe_flags_ignore |= flag;

        return !!flag;
}

static int ndev_mw_to_bar(struct intel_ntb_dev *ndev, int idx)
{
        if (idx < 0 || idx >= ndev->mw_count)
                return -EINVAL;
        return ndev->reg->mw_bar[idx];
}

static inline int ndev_db_addr(struct intel_ntb_dev *ndev,
                               phys_addr_t *db_addr, resource_size_t *db_size,
                               phys_addr_t reg_addr, unsigned long reg)
{
        if (ndev_is_unsafe(ndev, NTB_UNSAFE_DB))
                pr_warn_once("%s: NTB unsafe doorbell access", __func__);

        if (db_addr) {
                *db_addr = reg_addr + reg;
                dev_dbg(ndev_dev(ndev), "Peer db addr %llx\n", *db_addr);
        }

        if (db_size) {
                *db_size = ndev->reg->db_size;
                dev_dbg(ndev_dev(ndev), "Peer db size %llx\n", *db_size);
        }

        return 0;
}

static inline u64 ndev_db_read(struct intel_ntb_dev *ndev,
                               void __iomem *mmio)
{
        if (ndev_is_unsafe(ndev, NTB_UNSAFE_DB))
                pr_warn_once("%s: NTB unsafe doorbell access", __func__);

        return ndev->reg->db_ioread(mmio);
}

static inline int ndev_db_write(struct intel_ntb_dev *ndev, u64 db_bits,
                                void __iomem *mmio)
{
        if (ndev_is_unsafe(ndev, NTB_UNSAFE_DB))
                pr_warn_once("%s: NTB unsafe doorbell access", __func__);

        if (db_bits & ~ndev->db_valid_mask)
                return -EINVAL;

        ndev->reg->db_iowrite(db_bits, mmio);

        return 0;
}

static inline int ndev_db_set_mask(struct intel_ntb_dev *ndev, u64 db_bits,
                                   void __iomem *mmio)
{
        unsigned long irqflags;

        if (ndev_is_unsafe(ndev, NTB_UNSAFE_DB))
                pr_warn_once("%s: NTB unsafe doorbell access", __func__);

        if (db_bits & ~ndev->db_valid_mask)
                return -EINVAL;

        spin_lock_irqsave(&ndev->db_mask_lock, irqflags);
        {
                ndev->db_mask |= db_bits;
                ndev->reg->db_iowrite(ndev->db_mask, mmio);
        }
        spin_unlock_irqrestore(&ndev->db_mask_lock, irqflags);

        return 0;
}

static inline int ndev_db_clear_mask(struct intel_ntb_dev *ndev, u64 db_bits,
                                     void __iomem *mmio)
{
        unsigned long irqflags;

        if (ndev_is_unsafe(ndev, NTB_UNSAFE_DB))
                pr_warn_once("%s: NTB unsafe doorbell access", __func__);

        if (db_bits & ~ndev->db_valid_mask)
                return -EINVAL;

        spin_lock_irqsave(&ndev->db_mask_lock, irqflags);
        {
                ndev->db_mask &= ~db_bits;
                ndev->reg->db_iowrite(ndev->db_mask, mmio);
        }
        spin_unlock_irqrestore(&ndev->db_mask_lock, irqflags);

        return 0;
}

static inline int ndev_vec_mask(struct intel_ntb_dev *ndev, int db_vector)
{
        u64 shift, mask;

        shift = ndev->db_vec_shift;
        mask = BIT_ULL(shift) - 1;

        return mask << (shift * db_vector);
}

static inline int ndev_spad_addr(struct intel_ntb_dev *ndev, int idx,
                                 phys_addr_t *spad_addr, phys_addr_t reg_addr,
                                 unsigned long reg)
{
        if (ndev_is_unsafe(ndev, NTB_UNSAFE_SPAD))
                pr_warn_once("%s: NTB unsafe scratchpad access", __func__);

        if (idx < 0 || idx >= ndev->spad_count)
                return -EINVAL;

        if (spad_addr) {
                *spad_addr = reg_addr + reg + (idx << 2);
                dev_dbg(ndev_dev(ndev), "Peer spad addr %llx\n", *spad_addr);
        }

        return 0;
}

static inline u32 ndev_spad_read(struct intel_ntb_dev *ndev, int idx,
                                 void __iomem *mmio)
{
        if (ndev_is_unsafe(ndev, NTB_UNSAFE_SPAD))
                pr_warn_once("%s: NTB unsafe scratchpad access", __func__);

        if (idx < 0 || idx >= ndev->spad_count)
                return 0;

        return ioread32(mmio + (idx << 2));
}

static inline int ndev_spad_write(struct intel_ntb_dev *ndev, int idx, u32 val,
                                  void __iomem *mmio)
{
        if (ndev_is_unsafe(ndev, NTB_UNSAFE_SPAD))
                pr_warn_once("%s: NTB unsafe scratchpad access", __func__);

        if (idx < 0 || idx >= ndev->spad_count)
                return -EINVAL;

        iowrite32(val, mmio + (idx << 2));

        return 0;
}

static irqreturn_t ndev_interrupt(struct intel_ntb_dev *ndev, int vec)
{
        u64 vec_mask;

        vec_mask = ndev_vec_mask(ndev, vec);

        if ((ndev->hwerr_flags & NTB_HWERR_MSIX_VECTOR32_BAD) && (vec == 31))
                vec_mask |= ndev->db_link_mask;

        dev_dbg(ndev_dev(ndev), "vec %d vec_mask %llx\n", vec, vec_mask);

        ndev->last_ts = jiffies;

        if (vec_mask & ndev->db_link_mask) {
                if (ndev->reg->poll_link(ndev))
                        ntb_link_event(&ndev->ntb);
        }

        if (vec_mask & ndev->db_valid_mask)
                ntb_db_event(&ndev->ntb, vec);

        return IRQ_HANDLED;
}

static irqreturn_t ndev_vec_isr(int irq, void *dev)
{
        struct intel_ntb_vec *nvec = dev;

        dev_dbg(ndev_dev(nvec->ndev), "irq: %d  nvec->num: %d\n",
                irq, nvec->num);

        return ndev_interrupt(nvec->ndev, nvec->num);
}

static irqreturn_t ndev_irq_isr(int irq, void *dev)
{
        struct intel_ntb_dev *ndev = dev;

        return ndev_interrupt(ndev, irq - ndev_pdev(ndev)->irq);
}

static int ndev_init_isr(struct intel_ntb_dev *ndev,
                         int msix_min, int msix_max,
                         int msix_shift, int total_shift)
{
        struct pci_dev *pdev;
        int rc, i, msix_count, node;

        pdev = ndev_pdev(ndev);

        node = dev_to_node(&pdev->dev);

        /* Mask all doorbell interrupts */
        ndev->db_mask = ndev->db_valid_mask;
        ndev->reg->db_iowrite(ndev->db_mask,
                              ndev->self_mmio +
                              ndev->self_reg->db_mask);

        /* Try to set up msix irq */

        ndev->vec = kzalloc_node(msix_max * sizeof(*ndev->vec),
                                 GFP_KERNEL, node);
        if (!ndev->vec)
                goto err_msix_vec_alloc;

        ndev->msix = kzalloc_node(msix_max * sizeof(*ndev->msix),
                                  GFP_KERNEL, node);
        if (!ndev->msix)
                goto err_msix_alloc;

        for (i = 0; i < msix_max; ++i)
                ndev->msix[i].entry = i;

        msix_count = pci_enable_msix_range(pdev, ndev->msix,
                                           msix_min, msix_max);
        if (msix_count < 0)
                goto err_msix_enable;

        for (i = 0; i < msix_count; ++i) {
                ndev->vec[i].ndev = ndev;
                ndev->vec[i].num = i;
                rc = request_irq(ndev->msix[i].vector, ndev_vec_isr, 0,
                                 "ndev_vec_isr", &ndev->vec[i]);
                if (rc)
                        goto err_msix_request;
        }

        dev_dbg(ndev_dev(ndev), "Using %d msix interrupts\n", msix_count);
        ndev->db_vec_count = msix_count;
        ndev->db_vec_shift = msix_shift;
        return 0;

err_msix_request:
        while (i-- > 0)
                free_irq(ndev->msix[i].vector, &ndev->vec[i]);
        pci_disable_msix(pdev);
err_msix_enable:
        kfree(ndev->msix);
err_msix_alloc:
        kfree(ndev->vec);
err_msix_vec_alloc:
        ndev->msix = NULL;
        ndev->vec = NULL;

        /* Try to set up msi irq */

        rc = pci_enable_msi(pdev);
        if (rc)
                goto err_msi_enable;

        rc = request_irq(pdev->irq, ndev_irq_isr, 0,
                         "ndev_irq_isr", ndev);
        if (rc)
                goto err_msi_request;

        dev_dbg(ndev_dev(ndev), "Using msi interrupts\n");
        ndev->db_vec_count = 1;
        ndev->db_vec_shift = total_shift;
        return 0;

err_msi_request:
        pci_disable_msi(pdev);
err_msi_enable:

        /* Try to set up intx irq */

        pci_intx(pdev, 1);

        rc = request_irq(pdev->irq, ndev_irq_isr, IRQF_SHARED,
                         "ndev_irq_isr", ndev);
        if (rc)
                goto err_intx_request;

        dev_dbg(ndev_dev(ndev), "Using intx interrupts\n");
        ndev->db_vec_count = 1;
        ndev->db_vec_shift = total_shift;
        return 0;

err_intx_request:
        return rc;
}

static void ndev_deinit_isr(struct intel_ntb_dev *ndev)
{
        struct pci_dev *pdev;
        int i;

        pdev = ndev_pdev(ndev);

        /* Mask all doorbell interrupts */
        ndev->db_mask = ndev->db_valid_mask;
        ndev->reg->db_iowrite(ndev->db_mask,
                              ndev->self_mmio +
                              ndev->self_reg->db_mask);

        if (ndev->msix) {
                i = ndev->db_vec_count;
                while (i--)
                        free_irq(ndev->msix[i].vector, &ndev->vec[i]);
                pci_disable_msix(pdev);
                kfree(ndev->msix);
                kfree(ndev->vec);
        } else {
                free_irq(pdev->irq, ndev);
                if (pci_dev_msi_enabled(pdev))
                        pci_disable_msi(pdev);
        }
}

static ssize_t ndev_ntb3_debugfs_read(struct file *filp, char __user *ubuf,
                                      size_t count, loff_t *offp)
{
        struct intel_ntb_dev *ndev;
        void __iomem *mmio;
        char *buf;
        size_t buf_size;
        ssize_t ret, off;
        union { u64 v64; u32 v32; u16 v16; } u;

        ndev = filp->private_data;
        mmio = ndev->self_mmio;

        buf_size = min(count, 0x800ul);

        buf = kmalloc(buf_size, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        off = 0;

        off += scnprintf(buf + off, buf_size - off,
                         "NTB Device Information:\n");

        off += scnprintf(buf + off, buf_size - off,
                         "Connection Topology -\t%s\n",
                         ntb_topo_string(ndev->ntb.topo));

        off += scnprintf(buf + off, buf_size - off,
                         "NTB CTL -\t\t%#06x\n", ndev->ntb_ctl);
        off += scnprintf(buf + off, buf_size - off,
                         "LNK STA -\t\t%#06x\n", ndev->lnk_sta);

        if (!ndev->reg->link_is_up(ndev))
                off += scnprintf(buf + off, buf_size - off,
                                 "Link Status -\t\tDown\n");
        else {
                off += scnprintf(buf + off, buf_size - off,
                                 "Link Status -\t\tUp\n");
                off += scnprintf(buf + off, buf_size - off,
                                 "Link Speed -\t\tPCI-E Gen %u\n",
                                 NTB_LNK_STA_SPEED(ndev->lnk_sta));
                off += scnprintf(buf + off, buf_size - off,
                                 "Link Width -\t\tx%u\n",
                                 NTB_LNK_STA_WIDTH(ndev->lnk_sta));
        }

        off += scnprintf(buf + off, buf_size - off,
                         "Memory Window Count -\t%u\n", ndev->mw_count);
        off += scnprintf(buf + off, buf_size - off,
                         "Scratchpad Count -\t%u\n", ndev->spad_count);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Count -\t%u\n", ndev->db_count);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Vector Count -\t%u\n", ndev->db_vec_count);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Vector Shift -\t%u\n", ndev->db_vec_shift);

        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Valid Mask -\t%#llx\n", ndev->db_valid_mask);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Link Mask -\t%#llx\n", ndev->db_link_mask);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Mask Cached -\t%#llx\n", ndev->db_mask);

        u.v64 = ndev_db_read(ndev, mmio + ndev->self_reg->db_mask);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Mask -\t\t%#llx\n", u.v64);

        u.v64 = ndev_db_read(ndev, mmio + ndev->self_reg->db_bell);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Bell -\t\t%#llx\n", u.v64);

        off += scnprintf(buf + off, buf_size - off,
                         "\nNTB Incoming XLAT:\n");

        u.v64 = ioread64(mmio + SKX_IMBAR1XBASE_OFFSET);
        off += scnprintf(buf + off, buf_size - off,
                         "IMBAR1XBASE -\t\t%#018llx\n", u.v64);

        u.v64 = ioread64(mmio + SKX_IMBAR2XBASE_OFFSET);
        off += scnprintf(buf + off, buf_size - off,
                         "IMBAR2XBASE -\t\t%#018llx\n", u.v64);

        u.v64 = ioread64(mmio + SKX_IMBAR1XLMT_OFFSET);
        off += scnprintf(buf + off, buf_size - off,
                         "IMBAR1XLMT -\t\t\t%#018llx\n", u.v64);

        u.v64 = ioread64(mmio + SKX_IMBAR2XLMT_OFFSET);
        off += scnprintf(buf + off, buf_size - off,
                         "IMBAR2XLMT -\t\t\t%#018llx\n", u.v64);

        if (ntb_topo_is_b2b(ndev->ntb.topo)) {
                off += scnprintf(buf + off, buf_size - off,
                                 "\nNTB Outgoing B2B XLAT:\n");

                u.v64 = ioread64(mmio + SKX_EMBAR1XBASE_OFFSET);
                off += scnprintf(buf + off, buf_size - off,
                                 "EMBAR1XBASE -\t\t%#018llx\n", u.v64);

                u.v64 = ioread64(mmio + SKX_EMBAR2XBASE_OFFSET);
                off += scnprintf(buf + off, buf_size - off,
                                 "EMBAR2XBASE -\t\t%#018llx\n", u.v64);

                u.v64 = ioread64(mmio + SKX_EMBAR1XLMT_OFFSET);
                off += scnprintf(buf + off, buf_size - off,
                                 "EMBAR1XLMT -\t\t%#018llx\n", u.v64);

                u.v64 = ioread64(mmio + SKX_EMBAR2XLMT_OFFSET);
                off += scnprintf(buf + off, buf_size - off,
                                 "EMBAR2XLMT -\t\t%#018llx\n", u.v64);

                off += scnprintf(buf + off, buf_size - off,
                                 "\nNTB Secondary BAR:\n");

                u.v64 = ioread64(mmio + SKX_EMBAR0_OFFSET);
                off += scnprintf(buf + off, buf_size - off,
                                 "EMBAR0 -\t\t%#018llx\n", u.v64);

                u.v64 = ioread64(mmio + SKX_EMBAR1_OFFSET);
                off += scnprintf(buf + off, buf_size - off,
                                 "EMBAR1 -\t\t%#018llx\n", u.v64);

                u.v64 = ioread64(mmio + SKX_EMBAR2_OFFSET);
                off += scnprintf(buf + off, buf_size - off,
                                 "EMBAR2 -\t\t%#018llx\n", u.v64);
        }

        off += scnprintf(buf + off, buf_size - off,
                         "\nNTB Statistics:\n");

        u.v16 = ioread16(mmio + SKX_USMEMMISS_OFFSET);
        off += scnprintf(buf + off, buf_size - off,
                         "Upstream Memory Miss -\t%u\n", u.v16);

        off += scnprintf(buf + off, buf_size - off,
                         "\nNTB Hardware Errors:\n");

        if (!pci_read_config_word(ndev->ntb.pdev,
                                  SKX_DEVSTS_OFFSET, &u.v16))
                off += scnprintf(buf + off, buf_size - off,
                                 "DEVSTS -\t\t%#06x\n", u.v16);

        if (!pci_read_config_word(ndev->ntb.pdev,
                                  SKX_LINK_STATUS_OFFSET, &u.v16))
                off += scnprintf(buf + off, buf_size - off,
                                 "LNKSTS -\t\t%#06x\n", u.v16);

        if (!pci_read_config_dword(ndev->ntb.pdev,
                                   SKX_UNCERRSTS_OFFSET, &u.v32))
                off += scnprintf(buf + off, buf_size - off,
                                 "UNCERRSTS -\t\t%#06x\n", u.v32);

        if (!pci_read_config_dword(ndev->ntb.pdev,
                                   SKX_CORERRSTS_OFFSET, &u.v32))
                off += scnprintf(buf + off, buf_size - off,
                                 "CORERRSTS -\t\t%#06x\n", u.v32);

        ret = simple_read_from_buffer(ubuf, count, offp, buf, off);
        kfree(buf);
        return ret;
}

static ssize_t ndev_ntb_debugfs_read(struct file *filp, char __user *ubuf,
                                     size_t count, loff_t *offp)
{
        struct intel_ntb_dev *ndev;
        struct pci_dev *pdev;
        void __iomem *mmio;
        char *buf;
        size_t buf_size;
        ssize_t ret, off;
        union { u64 v64; u32 v32; u16 v16; u8 v8; } u;

        ndev = filp->private_data;
        pdev = ndev_pdev(ndev);
        mmio = ndev->self_mmio;

        buf_size = min(count, 0x800ul);

        buf = kmalloc(buf_size, GFP_KERNEL);
        if (!buf)
                return -ENOMEM;

        off = 0;

        off += scnprintf(buf + off, buf_size - off,
                         "NTB Device Information:\n");

        off += scnprintf(buf + off, buf_size - off,
                         "Connection Topology -\t%s\n",
                         ntb_topo_string(ndev->ntb.topo));

        if (ndev->b2b_idx != UINT_MAX) {
                off += scnprintf(buf + off, buf_size - off,
                                 "B2B MW Idx -\t\t%u\n", ndev->b2b_idx);
                off += scnprintf(buf + off, buf_size - off,
                                 "B2B Offset -\t\t%#lx\n", ndev->b2b_off);
        }

        off += scnprintf(buf + off, buf_size - off,
                         "BAR4 Split -\t\t%s\n",
                         ndev->bar4_split ? "yes" : "no");

        off += scnprintf(buf + off, buf_size - off,
                         "NTB CTL -\t\t%#06x\n", ndev->ntb_ctl);
        off += scnprintf(buf + off, buf_size - off,
                         "LNK STA -\t\t%#06x\n", ndev->lnk_sta);

        if (!ndev->reg->link_is_up(ndev)) {
                off += scnprintf(buf + off, buf_size - off,
                                 "Link Status -\t\tDown\n");
        } else {
                off += scnprintf(buf + off, buf_size - off,
                                 "Link Status -\t\tUp\n");
                off += scnprintf(buf + off, buf_size - off,
                                 "Link Speed -\t\tPCI-E Gen %u\n",
                                 NTB_LNK_STA_SPEED(ndev->lnk_sta));
                off += scnprintf(buf + off, buf_size - off,
                                 "Link Width -\t\tx%u\n",
                                 NTB_LNK_STA_WIDTH(ndev->lnk_sta));
        }

        off += scnprintf(buf + off, buf_size - off,
                         "Memory Window Count -\t%u\n", ndev->mw_count);
        off += scnprintf(buf + off, buf_size - off,
                         "Scratchpad Count -\t%u\n", ndev->spad_count);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Count -\t%u\n", ndev->db_count);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Vector Count -\t%u\n", ndev->db_vec_count);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Vector Shift -\t%u\n", ndev->db_vec_shift);

        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Valid Mask -\t%#llx\n", ndev->db_valid_mask);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Link Mask -\t%#llx\n", ndev->db_link_mask);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Mask Cached -\t%#llx\n", ndev->db_mask);

        u.v64 = ndev_db_read(ndev, mmio + ndev->self_reg->db_mask);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Mask -\t\t%#llx\n", u.v64);

        u.v64 = ndev_db_read(ndev, mmio + ndev->self_reg->db_bell);
        off += scnprintf(buf + off, buf_size - off,
                         "Doorbell Bell -\t\t%#llx\n", u.v64);

        off += scnprintf(buf + off, buf_size - off,
                         "\nNTB Window Size:\n");

        pci_read_config_byte(pdev, XEON_PBAR23SZ_OFFSET, &u.v8);
        off += scnprintf(buf + off, buf_size - off,
                         "PBAR23SZ %hhu\n", u.v8);
        if (!ndev->bar4_split) {
                pci_read_config_byte(pdev, XEON_PBAR45SZ_OFFSET, &u.v8);
                off += scnprintf(buf + off, buf_size - off,
                                 "PBAR45SZ %hhu\n", u.v8);
        } else {
                pci_read_config_byte(pdev, XEON_PBAR4SZ_OFFSET, &u.v8);
                off += scnprintf(buf + off, buf_size - off,
                                 "PBAR4SZ %hhu\n", u.v8);
                pci_read_config_byte(pdev, XEON_PBAR5SZ_OFFSET, &u.v8);
                off += scnprintf(buf + off, buf_size - off,
                                 "PBAR5SZ %hhu\n", u.v8);
        }

        pci_read_config_byte(pdev, XEON_SBAR23SZ_OFFSET, &u.v8);
        off += scnprintf(buf + off, buf_size - off,
                         "SBAR23SZ %hhu\n", u.v8);
        if (!ndev->bar4_split) {
                pci_read_config_byte(pdev, XEON_SBAR45SZ_OFFSET, &u.v8);
                off += scnprintf(buf + off, buf_size - off,
                                 "SBAR45SZ %hhu\n", u.v8);
        } else {
                pci_read_config_byte(pdev, XEON_SBAR4SZ_OFFSET, &u.v8);
                off += scnprintf(buf + off, buf_size - off,
                                 "SBAR4SZ %hhu\n", u.v8);
                pci_read_config_byte(pdev, XEON_SBAR5SZ_OFFSET, &u.v8);
                off += scnprintf(buf + off, buf_size - off,
                                 "SBAR5SZ %hhu\n", u.v8);
        }

        off += scnprintf(buf + off, buf_size - off,
                         "\nNTB Incoming XLAT:\n");

        u.v64 = ioread64(mmio + bar2_off(ndev->xlat_reg->bar2_xlat, 2));
        off += scnprintf(buf + off, buf_size - off,
                         "XLAT23 -\t\t%#018llx\n", u.v64);

        if (ndev->bar4_split) {
                u.v32 = ioread32(mmio + bar2_off(ndev->xlat_reg->bar2_xlat, 4));
                off += scnprintf(buf + off, buf_size - off,
                                 "XLAT4 -\t\t\t%#06x\n", u.v32);

                u.v32 = ioread32(mmio + bar2_off(ndev->xlat_reg->bar2_xlat, 5));
                off += scnprintf(buf + off, buf_size - off,
                                 "XLAT5 -\t\t\t%#06x\n", u.v32);
        } else {
                u.v64 = ioread64(mmio + bar2_off(ndev->xlat_reg->bar2_xlat, 4));
                off += scnprintf(buf + off, buf_size - off,
                                 "XLAT45 -\t\t%#018llx\n", u.v64);
        }

        u.v64 = ioread64(mmio + bar2_off(ndev->xlat_reg->bar2_limit, 2));
        off += scnprintf(buf + off, buf_size - off,
                         "LMT23 -\t\t\t%#018llx\n", u.v64);

        if (ndev->bar4_split) {
                u.v32 = ioread32(mmio + bar2_off(ndev->xlat_reg->bar2_limit, 4));
                off += scnprintf(buf + off, buf_size - off,
                                 "LMT4 -\t\t\t%#06x\n", u.v32);
                u.v32 = ioread32(mmio + bar2_off(ndev->xlat_reg->bar2_limit, 5));
                off += scnprintf(buf + off, buf_size - off,
                                 "LMT5 -\t\t\t%#06x\n", u.v32);
        } else {
                u.v64 = ioread64(mmio + bar2_off(ndev->xlat_reg->bar2_limit, 4));
                off += scnprintf(buf + off, buf_size - off,
                                 "LMT45 -\t\t\t%#018llx\n", u.v64);
        }

        if (pdev_is_xeon(pdev)) {
                if (ntb_topo_is_b2b(ndev->ntb.topo)) {
                        off += scnprintf(buf + off, buf_size - off,
                                         "\nNTB Outgoing B2B XLAT:\n");

                        u.v64 = ioread64(mmio + XEON_PBAR23XLAT_OFFSET);
                        off += scnprintf(buf + off, buf_size - off,
                                         "B2B XLAT23 -\t\t%#018llx\n", u.v64);

                        if (ndev->bar4_split) {
                                u.v32 = ioread32(mmio + XEON_PBAR4XLAT_OFFSET);
                                off += scnprintf(buf + off, buf_size - off,
                                                 "B2B XLAT4 -\t\t%#06x\n",
                                                 u.v32);
                                u.v32 = ioread32(mmio + XEON_PBAR5XLAT_OFFSET);
                                off += scnprintf(buf + off, buf_size - off,
                                                 "B2B XLAT5 -\t\t%#06x\n",
                                                 u.v32);
                        } else {
                                u.v64 = ioread64(mmio + XEON_PBAR45XLAT_OFFSET);
                                off += scnprintf(buf + off, buf_size - off,
                                                 "B2B XLAT45 -\t\t%#018llx\n",
                                                 u.v64);
                        }

                        u.v64 = ioread64(mmio + XEON_PBAR23LMT_OFFSET);
                        off += scnprintf(buf + off, buf_size - off,
                                         "B2B LMT23 -\t\t%#018llx\n", u.v64);

                        if (ndev->bar4_split) {
                                u.v32 = ioread32(mmio + XEON_PBAR4LMT_OFFSET);
                                off += scnprintf(buf + off, buf_size - off,
                                                 "B2B LMT4 -\t\t%#06x\n",
                                                 u.v32);
                                u.v32 = ioread32(mmio + XEON_PBAR5LMT_OFFSET);
                                off += scnprintf(buf + off, buf_size - off,
                                                 "B2B LMT5 -\t\t%#06x\n",
                                                 u.v32);
                        } else {
                                u.v64 = ioread64(mmio + XEON_PBAR45LMT_OFFSET);
                                off += scnprintf(buf + off, buf_size - off,
                                                 "B2B LMT45 -\t\t%#018llx\n",
                                                 u.v64);
                        }

                        off += scnprintf(buf + off, buf_size - off,
                                         "\nNTB Secondary BAR:\n");

                        u.v64 = ioread64(mmio + XEON_SBAR0BASE_OFFSET);
                        off += scnprintf(buf + off, buf_size - off,
                                         "SBAR01 -\t\t%#018llx\n", u.v64);

                        u.v64 = ioread64(mmio + XEON_SBAR23BASE_OFFSET);
                        off += scnprintf(buf + off, buf_size - off,
                                         "SBAR23 -\t\t%#018llx\n", u.v64);

                        if (ndev->bar4_split) {
                                u.v32 = ioread32(mmio + XEON_SBAR4BASE_OFFSET);
                                off += scnprintf(buf + off, buf_size - off,
                                                 "SBAR4 -\t\t\t%#06x\n", u.v32);
                                u.v32 = ioread32(mmio + XEON_SBAR5BASE_OFFSET);
                                off += scnprintf(buf + off, buf_size - off,
                                                 "SBAR5 -\t\t\t%#06x\n", u.v32);
                        } else {
                                u.v64 = ioread64(mmio + XEON_SBAR45BASE_OFFSET);
                                off += scnprintf(buf + off, buf_size - off,
                                                 "SBAR45 -\t\t%#018llx\n",
                                                 u.v64);
                        }
                }

                off += scnprintf(buf + off, buf_size - off,
                                 "\nXEON NTB Statistics:\n");

                u.v16 = ioread16(mmio + XEON_USMEMMISS_OFFSET);
                off += scnprintf(buf + off, buf_size - off,
                                 "Upstream Memory Miss -\t%u\n", u.v16);

                off += scnprintf(buf + off, buf_size - off,
                                 "\nXEON NTB Hardware Errors:\n");

                if (!pci_read_config_word(pdev,
                                          XEON_DEVSTS_OFFSET, &u.v16))
                        off += scnprintf(buf + off, buf_size - off,
                                         "DEVSTS -\t\t%#06x\n", u.v16);

                if (!pci_read_config_word(pdev,
                                          XEON_LINK_STATUS_OFFSET, &u.v16))
                        off += scnprintf(buf + off, buf_size - off,
                                         "LNKSTS -\t\t%#06x\n", u.v16);

                if (!pci_read_config_dword(pdev,
                                           XEON_UNCERRSTS_OFFSET, &u.v32))
                        off += scnprintf(buf + off, buf_size - off,
                                         "UNCERRSTS -\t\t%#06x\n", u.v32);

                if (!pci_read_config_dword(pdev,
                                           XEON_CORERRSTS_OFFSET, &u.v32))
                        off += scnprintf(buf + off, buf_size - off,
                                         "CORERRSTS -\t\t%#06x\n", u.v32);
        }

        ret = simple_read_from_buffer(ubuf, count, offp, buf, off);
        kfree(buf);
        return ret;
}

static ssize_t ndev_debugfs_read(struct file *filp, char __user *ubuf,
                                 size_t count, loff_t *offp)
{
        struct intel_ntb_dev *ndev = filp->private_data;

        if (pdev_is_xeon(ndev->ntb.pdev) ||
            pdev_is_atom(ndev->ntb.pdev))
                return ndev_ntb_debugfs_read(filp, ubuf, count, offp);
        else if (pdev_is_skx_xeon(ndev->ntb.pdev))
                return ndev_ntb3_debugfs_read(filp, ubuf, count, offp);

        return -ENXIO;
}

static void ndev_init_debugfs(struct intel_ntb_dev *ndev)
{
        if (!debugfs_dir) {
                ndev->debugfs_dir = NULL;
                ndev->debugfs_info = NULL;
        } else {
                ndev->debugfs_dir =
                        debugfs_create_dir(ndev_name(ndev), debugfs_dir);
                if (!ndev->debugfs_dir)
                        ndev->debugfs_info = NULL;
                else
                        ndev->debugfs_info =
                                debugfs_create_file("info", S_IRUSR,
                                                    ndev->debugfs_dir, ndev,
                                                    &intel_ntb_debugfs_info);
        }
}

static void ndev_deinit_debugfs(struct intel_ntb_dev *ndev)
{
        debugfs_remove_recursive(ndev->debugfs_dir);
}

static int intel_ntb_mw_count(struct ntb_dev *ntb)
{
        return ntb_ndev(ntb)->mw_count;
}

static int intel_ntb_mw_get_range(struct ntb_dev *ntb, int idx,
                                  phys_addr_t *base,
                                  resource_size_t *size,
                                  resource_size_t *align,
                                  resource_size_t *align_size)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);
        int bar;

        if (idx >= ndev->b2b_idx && !ndev->b2b_off)
                idx += 1;

        bar = ndev_mw_to_bar(ndev, idx);
        if (bar < 0)
                return bar;

        if (base)
                *base = pci_resource_start(ndev->ntb.pdev, bar) +
                        (idx == ndev->b2b_idx ? ndev->b2b_off : 0);

        if (size)
                *size = pci_resource_len(ndev->ntb.pdev, bar) -
                        (idx == ndev->b2b_idx ? ndev->b2b_off : 0);

        if (align)
                *align = pci_resource_len(ndev->ntb.pdev, bar);

        if (align_size)
                *align_size = 1;

        return 0;
}

static int intel_ntb_mw_set_trans(struct ntb_dev *ntb, int idx,
                                  dma_addr_t addr, resource_size_t size)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);
        unsigned long base_reg, xlat_reg, limit_reg;
        resource_size_t bar_size, mw_size;
        void __iomem *mmio;
        u64 base, limit, reg_val;
        int bar;

        if (idx >= ndev->b2b_idx && !ndev->b2b_off)
                idx += 1;

        bar = ndev_mw_to_bar(ndev, idx);
        if (bar < 0)
                return bar;

        bar_size = pci_resource_len(ndev->ntb.pdev, bar);

        if (idx == ndev->b2b_idx)
                mw_size = bar_size - ndev->b2b_off;
        else
                mw_size = bar_size;

        /* hardware requires that addr is aligned to bar size */
        if (addr & (bar_size - 1))
                return -EINVAL;

        /* make sure the range fits in the usable mw size */
        if (size > mw_size)
                return -EINVAL;

        mmio = ndev->self_mmio;
        base_reg = bar0_off(ndev->xlat_reg->bar0_base, bar);
        xlat_reg = bar2_off(ndev->xlat_reg->bar2_xlat, bar);
        limit_reg = bar2_off(ndev->xlat_reg->bar2_limit, bar);

        if (bar < 4 || !ndev->bar4_split) {
                base = ioread64(mmio + base_reg) & NTB_BAR_MASK_64;

                /* Set the limit if supported, if size is not mw_size */
                if (limit_reg && size != mw_size)
                        limit = base + size;
                else
                        limit = 0;

                /* set and verify setting the translation address */
                iowrite64(addr, mmio + xlat_reg);
                reg_val = ioread64(mmio + xlat_reg);
                if (reg_val != addr) {
                        iowrite64(0, mmio + xlat_reg);
                        return -EIO;
                }

                /* set and verify setting the limit */
                iowrite64(limit, mmio + limit_reg);
                reg_val = ioread64(mmio + limit_reg);
                if (reg_val != limit) {
                        iowrite64(base, mmio + limit_reg);
                        iowrite64(0, mmio + xlat_reg);
                        return -EIO;
                }
        } else {
                /* split bar addr range must all be 32 bit */
                if (addr & (~0ull << 32))
                        return -EINVAL;
                if ((addr + size) & (~0ull << 32))
                        return -EINVAL;

                base = ioread32(mmio + base_reg) & NTB_BAR_MASK_32;

                /* Set the limit if supported, if size is not mw_size */
                if (limit_reg && size != mw_size)
                        limit = base + size;
                else
                        limit = 0;

                /* set and verify setting the translation address */
                iowrite32(addr, mmio + xlat_reg);
                reg_val = ioread32(mmio + xlat_reg);
                if (reg_val != addr) {
                        iowrite32(0, mmio + xlat_reg);
                        return -EIO;
                }

                /* set and verify setting the limit */
                iowrite32(limit, mmio + limit_reg);
                reg_val = ioread32(mmio + limit_reg);
                if (reg_val != limit) {
                        iowrite32(base, mmio + limit_reg);
                        iowrite32(0, mmio + xlat_reg);
                        return -EIO;
                }
        }

        return 0;
}

static int intel_ntb_link_is_up(struct ntb_dev *ntb,
                                enum ntb_speed *speed,
                                enum ntb_width *width)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        if (ndev->reg->link_is_up(ndev)) {
                if (speed)
                        *speed = NTB_LNK_STA_SPEED(ndev->lnk_sta);
                if (width)
                        *width = NTB_LNK_STA_WIDTH(ndev->lnk_sta);
                return 1;
        } else {
                /* TODO MAYBE: is it possible to observe the link speed and
                 * width while link is training? */
                if (speed)
                        *speed = NTB_SPEED_NONE;
                if (width)
                        *width = NTB_WIDTH_NONE;
                return 0;
        }
}

static int intel_ntb_link_enable(struct ntb_dev *ntb,
                                 enum ntb_speed max_speed,
                                 enum ntb_width max_width)
{
        struct intel_ntb_dev *ndev;
        u32 ntb_ctl;

        ndev = container_of(ntb, struct intel_ntb_dev, ntb);

        if (ndev->ntb.topo == NTB_TOPO_SEC)
                return -EINVAL;

        dev_dbg(ndev_dev(ndev),
                "Enabling link with max_speed %d max_width %d\n",
                max_speed, max_width);
        if (max_speed != NTB_SPEED_AUTO)
                dev_dbg(ndev_dev(ndev), "ignoring max_speed %d\n", max_speed);
        if (max_width != NTB_WIDTH_AUTO)
                dev_dbg(ndev_dev(ndev), "ignoring max_width %d\n", max_width);

        ntb_ctl = ioread32(ndev->self_mmio + ndev->reg->ntb_ctl);
        ntb_ctl &= ~(NTB_CTL_DISABLE | NTB_CTL_CFG_LOCK);
        ntb_ctl |= NTB_CTL_P2S_BAR2_SNOOP | NTB_CTL_S2P_BAR2_SNOOP;
        ntb_ctl |= NTB_CTL_P2S_BAR4_SNOOP | NTB_CTL_S2P_BAR4_SNOOP;
        if (ndev->bar4_split)
                ntb_ctl |= NTB_CTL_P2S_BAR5_SNOOP | NTB_CTL_S2P_BAR5_SNOOP;
        iowrite32(ntb_ctl, ndev->self_mmio + ndev->reg->ntb_ctl);

        return 0;
}

static int intel_ntb_link_disable(struct ntb_dev *ntb)
{
        struct intel_ntb_dev *ndev;
        u32 ntb_cntl;

        ndev = container_of(ntb, struct intel_ntb_dev, ntb);

        if (ndev->ntb.topo == NTB_TOPO_SEC)
                return -EINVAL;

        dev_dbg(ndev_dev(ndev), "Disabling link\n");

        /* Bring NTB link down */
        ntb_cntl = ioread32(ndev->self_mmio + ndev->reg->ntb_ctl);
        ntb_cntl &= ~(NTB_CTL_P2S_BAR2_SNOOP | NTB_CTL_S2P_BAR2_SNOOP);
        ntb_cntl &= ~(NTB_CTL_P2S_BAR4_SNOOP | NTB_CTL_S2P_BAR4_SNOOP);
        if (ndev->bar4_split)
                ntb_cntl &= ~(NTB_CTL_P2S_BAR5_SNOOP | NTB_CTL_S2P_BAR5_SNOOP);
        ntb_cntl |= NTB_CTL_DISABLE | NTB_CTL_CFG_LOCK;
        iowrite32(ntb_cntl, ndev->self_mmio + ndev->reg->ntb_ctl);

        return 0;
}

static int intel_ntb_db_is_unsafe(struct ntb_dev *ntb)
{
        return ndev_ignore_unsafe(ntb_ndev(ntb), NTB_UNSAFE_DB);
}

static u64 intel_ntb_db_valid_mask(struct ntb_dev *ntb)
{
        return ntb_ndev(ntb)->db_valid_mask;
}

static int intel_ntb_db_vector_count(struct ntb_dev *ntb)
{
        struct intel_ntb_dev *ndev;

        ndev = container_of(ntb, struct intel_ntb_dev, ntb);

        return ndev->db_vec_count;
}

static u64 intel_ntb_db_vector_mask(struct ntb_dev *ntb, int db_vector)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        if (db_vector < 0 || db_vector > ndev->db_vec_count)
                return 0;

        return ndev->db_valid_mask & ndev_vec_mask(ndev, db_vector);
}

static u64 intel_ntb_db_read(struct ntb_dev *ntb)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        return ndev_db_read(ndev,
                            ndev->self_mmio +
                            ndev->self_reg->db_bell);
}

static int intel_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        return ndev_db_write(ndev, db_bits,
                             ndev->self_mmio +
                             ndev->self_reg->db_bell);
}

static int intel_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        return ndev_db_set_mask(ndev, db_bits,
                                ndev->self_mmio +
                                ndev->self_reg->db_mask);
}

static int intel_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        return ndev_db_clear_mask(ndev, db_bits,
                                  ndev->self_mmio +
                                  ndev->self_reg->db_mask);
}

static int intel_ntb_peer_db_addr(struct ntb_dev *ntb,
                                  phys_addr_t *db_addr,
                                  resource_size_t *db_size)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        return ndev_db_addr(ndev, db_addr, db_size, ndev->peer_addr,
                            ndev->peer_reg->db_bell);
}

static int intel_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        return ndev_db_write(ndev, db_bits,
                             ndev->peer_mmio +
                             ndev->peer_reg->db_bell);
}

static int intel_ntb_spad_is_unsafe(struct ntb_dev *ntb)
{
        return ndev_ignore_unsafe(ntb_ndev(ntb), NTB_UNSAFE_SPAD);
}

static int intel_ntb_spad_count(struct ntb_dev *ntb)
{
        struct intel_ntb_dev *ndev;

        ndev = container_of(ntb, struct intel_ntb_dev, ntb);

        return ndev->spad_count;
}

static u32 intel_ntb_spad_read(struct ntb_dev *ntb, int idx)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        return ndev_spad_read(ndev, idx,
                              ndev->self_mmio +
                              ndev->self_reg->spad);
}

static int intel_ntb_spad_write(struct ntb_dev *ntb,
                                int idx, u32 val)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        return ndev_spad_write(ndev, idx, val,
                               ndev->self_mmio +
                               ndev->self_reg->spad);
}

static int intel_ntb_peer_spad_addr(struct ntb_dev *ntb, int idx,
                                    phys_addr_t *spad_addr)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        return ndev_spad_addr(ndev, idx, spad_addr, ndev->peer_addr,
                              ndev->peer_reg->spad);
}

static u32 intel_ntb_peer_spad_read(struct ntb_dev *ntb, int idx)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        return ndev_spad_read(ndev, idx,
                              ndev->peer_mmio +
                              ndev->peer_reg->spad);
}

static int intel_ntb_peer_spad_write(struct ntb_dev *ntb,
                                     int idx, u32 val)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        return ndev_spad_write(ndev, idx, val,
                               ndev->peer_mmio +
                               ndev->peer_reg->spad);
}

/* ATOM */

static u64 atom_db_ioread(void __iomem *mmio)
{
        return ioread64(mmio);
}

static void atom_db_iowrite(u64 bits, void __iomem *mmio)
{
        iowrite64(bits, mmio);
}

static int atom_poll_link(struct intel_ntb_dev *ndev)
{
        u32 ntb_ctl;

        ntb_ctl = ioread32(ndev->self_mmio + ATOM_NTBCNTL_OFFSET);

        if (ntb_ctl == ndev->ntb_ctl)
                return 0;

        ndev->ntb_ctl = ntb_ctl;

        ndev->lnk_sta = ioread32(ndev->self_mmio + ATOM_LINK_STATUS_OFFSET);

        return 1;
}

static int atom_link_is_up(struct intel_ntb_dev *ndev)
{
        return ATOM_NTB_CTL_ACTIVE(ndev->ntb_ctl);
}

static int atom_link_is_err(struct intel_ntb_dev *ndev)
{
        if (ioread32(ndev->self_mmio + ATOM_LTSSMSTATEJMP_OFFSET)
            & ATOM_LTSSMSTATEJMP_FORCEDETECT)
                return 1;

        if (ioread32(ndev->self_mmio + ATOM_IBSTERRRCRVSTS0_OFFSET)
            & ATOM_IBIST_ERR_OFLOW)
                return 1;

        return 0;
}

static inline enum ntb_topo atom_ppd_topo(struct intel_ntb_dev *ndev, u32 ppd)
{
        switch (ppd & ATOM_PPD_TOPO_MASK) {
        case ATOM_PPD_TOPO_B2B_USD:
                dev_dbg(ndev_dev(ndev), "PPD %d B2B USD\n", ppd);
                return NTB_TOPO_B2B_USD;

        case ATOM_PPD_TOPO_B2B_DSD:
                dev_dbg(ndev_dev(ndev), "PPD %d B2B DSD\n", ppd);
                return NTB_TOPO_B2B_DSD;

        case ATOM_PPD_TOPO_PRI_USD:
        case ATOM_PPD_TOPO_PRI_DSD: /* accept bogus PRI_DSD */
        case ATOM_PPD_TOPO_SEC_USD:
        case ATOM_PPD_TOPO_SEC_DSD: /* accept bogus SEC_DSD */
                dev_dbg(ndev_dev(ndev), "PPD %d non B2B disabled\n", ppd);
                return NTB_TOPO_NONE;
        }

        dev_dbg(ndev_dev(ndev), "PPD %d invalid\n", ppd);
        return NTB_TOPO_NONE;
}

static void atom_link_hb(struct work_struct *work)
{
        struct intel_ntb_dev *ndev = hb_ndev(work);
        unsigned long poll_ts;
        void __iomem *mmio;
        u32 status32;

        poll_ts = ndev->last_ts + ATOM_LINK_HB_TIMEOUT;

        /* Delay polling the link status if an interrupt was received,
         * unless the cached link status says the link is down.
         */
        if (time_after(poll_ts, jiffies) && atom_link_is_up(ndev)) {
                schedule_delayed_work(&ndev->hb_timer, poll_ts - jiffies);
                return;
        }

        if (atom_poll_link(ndev))
                ntb_link_event(&ndev->ntb);

        if (atom_link_is_up(ndev) || !atom_link_is_err(ndev)) {
                schedule_delayed_work(&ndev->hb_timer, ATOM_LINK_HB_TIMEOUT);
                return;
        }

        /* Link is down with error: recover the link! */

        mmio = ndev->self_mmio;

        /* Driver resets the NTB ModPhy lanes - magic! */
        iowrite8(0xe0, mmio + ATOM_MODPHY_PCSREG6);
        iowrite8(0x40, mmio + ATOM_MODPHY_PCSREG4);
        iowrite8(0x60, mmio + ATOM_MODPHY_PCSREG4);
        iowrite8(0x60, mmio + ATOM_MODPHY_PCSREG6);

        /* Driver waits 100ms to allow the NTB ModPhy to settle */
        msleep(100);

        /* Clear AER Errors, write to clear */
        status32 = ioread32(mmio + ATOM_ERRCORSTS_OFFSET);
        dev_dbg(ndev_dev(ndev), "ERRCORSTS = %x\n", status32);
        status32 &= PCI_ERR_COR_REP_ROLL;
        iowrite32(status32, mmio + ATOM_ERRCORSTS_OFFSET);

        /* Clear unexpected electrical idle event in LTSSM, write to clear */
        status32 = ioread32(mmio + ATOM_LTSSMERRSTS0_OFFSET);
        dev_dbg(ndev_dev(ndev), "LTSSMERRSTS0 = %x\n", status32);
        status32 |= ATOM_LTSSMERRSTS0_UNEXPECTEDEI;
        iowrite32(status32, mmio + ATOM_LTSSMERRSTS0_OFFSET);

        /* Clear DeSkew Buffer error, write to clear */
        status32 = ioread32(mmio + ATOM_DESKEWSTS_OFFSET);
        dev_dbg(ndev_dev(ndev), "DESKEWSTS = %x\n", status32);
        status32 |= ATOM_DESKEWSTS_DBERR;
        iowrite32(status32, mmio + ATOM_DESKEWSTS_OFFSET);

        status32 = ioread32(mmio + ATOM_IBSTERRRCRVSTS0_OFFSET);
        dev_dbg(ndev_dev(ndev), "IBSTERRRCRVSTS0 = %x\n", status32);
        status32 &= ATOM_IBIST_ERR_OFLOW;
        iowrite32(status32, mmio + ATOM_IBSTERRRCRVSTS0_OFFSET);

        /* Releases the NTB state machine to allow the link to retrain */
        status32 = ioread32(mmio + ATOM_LTSSMSTATEJMP_OFFSET);
        dev_dbg(ndev_dev(ndev), "LTSSMSTATEJMP = %x\n", status32);
        status32 &= ~ATOM_LTSSMSTATEJMP_FORCEDETECT;
        iowrite32(status32, mmio + ATOM_LTSSMSTATEJMP_OFFSET);

        /* There is a potential race between the 2 NTB devices recovering at the
         * same time.  If the times are the same, the link will not recover and
         * the driver will be stuck in this loop forever.  Add a random interval
         * to the recovery time to prevent this race.
         */
        schedule_delayed_work(&ndev->hb_timer, ATOM_LINK_RECOVERY_TIME
                              + prandom_u32() % ATOM_LINK_RECOVERY_TIME);
}

static int atom_init_isr(struct intel_ntb_dev *ndev)
{
        int rc;

        rc = ndev_init_isr(ndev, 1, ATOM_DB_MSIX_VECTOR_COUNT,
                           ATOM_DB_MSIX_VECTOR_SHIFT, ATOM_DB_TOTAL_SHIFT);
        if (rc)
                return rc;

        /* ATOM doesn't have link status interrupt, poll on that platform */
        ndev->last_ts = jiffies;
        INIT_DELAYED_WORK(&ndev->hb_timer, atom_link_hb);
        schedule_delayed_work(&ndev->hb_timer, ATOM_LINK_HB_TIMEOUT);

        return 0;
}

static void atom_deinit_isr(struct intel_ntb_dev *ndev)
{
        cancel_delayed_work_sync(&ndev->hb_timer);
        ndev_deinit_isr(ndev);
}

static int atom_init_ntb(struct intel_ntb_dev *ndev)
{
        ndev->mw_count = ATOM_MW_COUNT;
        ndev->spad_count = ATOM_SPAD_COUNT;
        ndev->db_count = ATOM_DB_COUNT;

        switch (ndev->ntb.topo) {
        case NTB_TOPO_B2B_USD:
        case NTB_TOPO_B2B_DSD:
                ndev->self_reg = &atom_pri_reg;
                ndev->peer_reg = &atom_b2b_reg;
                ndev->xlat_reg = &atom_sec_xlat;

                /* Enable Bus Master and Memory Space on the secondary side */
                iowrite16(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER,
                          ndev->self_mmio + ATOM_SPCICMD_OFFSET);

                break;

        default:
                return -EINVAL;
        }

        ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;

        return 0;
}

static int atom_init_dev(struct intel_ntb_dev *ndev)
{
        u32 ppd;
        int rc;

        rc = pci_read_config_dword(ndev->ntb.pdev, ATOM_PPD_OFFSET, &ppd);
        if (rc)
                return -EIO;

        ndev->ntb.topo = atom_ppd_topo(ndev, ppd);
        if (ndev->ntb.topo == NTB_TOPO_NONE)
                return -EINVAL;

        rc = atom_init_ntb(ndev);
        if (rc)
                return rc;

        rc = atom_init_isr(ndev);
        if (rc)
                return rc;

        if (ndev->ntb.topo != NTB_TOPO_SEC) {
                /* Initiate PCI-E link training */
                rc = pci_write_config_dword(ndev->ntb.pdev, ATOM_PPD_OFFSET,
                                            ppd | ATOM_PPD_INIT_LINK);
                if (rc)
                        return rc;
        }

        return 0;
}

static void atom_deinit_dev(struct intel_ntb_dev *ndev)
{
        atom_deinit_isr(ndev);
}

/* Skylake Xeon NTB */

static int skx_poll_link(struct intel_ntb_dev *ndev)
{
        u16 reg_val;
        int rc;

        ndev->reg->db_iowrite(ndev->db_link_mask,
                              ndev->self_mmio +
                              ndev->self_reg->db_clear);

        rc = pci_read_config_word(ndev->ntb.pdev,
                                  SKX_LINK_STATUS_OFFSET, &reg_val);
        if (rc)
                return 0;

        if (reg_val == ndev->lnk_sta)
                return 0;

        ndev->lnk_sta = reg_val;

        return 1;
}

static u64 skx_db_ioread(void __iomem *mmio)
{
        return ioread64(mmio);
}

static void skx_db_iowrite(u64 bits, void __iomem *mmio)
{
        iowrite64(bits, mmio);
}

static int skx_init_isr(struct intel_ntb_dev *ndev)
{
        int i;

        /*
         * The MSIX vectors and the interrupt status bits are not lined up
         * on Skylake. By default the link status bit is bit 32, however it
         * is by default MSIX vector0. We need to fixup to line them up.
         * The vectors at reset is 1-32,0. We need to reprogram to 0-32.
         */

        for (i = 0; i < SKX_DB_MSIX_VECTOR_COUNT; i++)
                iowrite8(i, ndev->self_mmio + SKX_INTVEC_OFFSET + i);

        /* move link status down one as workaround */
        if (ndev->hwerr_flags & NTB_HWERR_MSIX_VECTOR32_BAD) {
                iowrite8(SKX_DB_MSIX_VECTOR_COUNT - 2,
                         ndev->self_mmio + SKX_INTVEC_OFFSET +
                         (SKX_DB_MSIX_VECTOR_COUNT - 1));
        }

        return ndev_init_isr(ndev, SKX_DB_MSIX_VECTOR_COUNT,
                             SKX_DB_MSIX_VECTOR_COUNT,
                             SKX_DB_MSIX_VECTOR_SHIFT,
                             SKX_DB_TOTAL_SHIFT);
}

static int skx_setup_b2b_mw(struct intel_ntb_dev *ndev,
                            const struct intel_b2b_addr *addr,
                            const struct intel_b2b_addr *peer_addr)
{
        struct pci_dev *pdev;
        void __iomem *mmio;
        resource_size_t bar_size;
        phys_addr_t bar_addr;
        int b2b_bar;
        u8 bar_sz;

        pdev = ndev_pdev(ndev);
        mmio = ndev->self_mmio;

        if (ndev->b2b_idx == UINT_MAX) {
                dev_dbg(ndev_dev(ndev), "not using b2b mw\n");
                b2b_bar = 0;
                ndev->b2b_off = 0;
        } else {
                b2b_bar = ndev_mw_to_bar(ndev, ndev->b2b_idx);
                if (b2b_bar < 0)
                        return -EIO;

                dev_dbg(ndev_dev(ndev), "using b2b mw bar %d\n", b2b_bar);

                bar_size = pci_resource_len(ndev->ntb.pdev, b2b_bar);

                dev_dbg(ndev_dev(ndev), "b2b bar size %#llx\n", bar_size);

                if (b2b_mw_share && ((bar_size >> 1) >= XEON_B2B_MIN_SIZE)) {
                        dev_dbg(ndev_dev(ndev),
                                "b2b using first half of bar\n");
                        ndev->b2b_off = bar_size >> 1;
                } else if (bar_size >= XEON_B2B_MIN_SIZE) {
                        dev_dbg(ndev_dev(ndev),
                                "b2b using whole bar\n");
                        ndev->b2b_off = 0;
                        --ndev->mw_count;
                } else {
                        dev_dbg(ndev_dev(ndev),
                                "b2b bar size is too small\n");
                        return -EIO;
                }
        }

        /*
         * Reset the secondary bar sizes to match the primary bar sizes,
         * except disable or halve the size of the b2b secondary bar.
         */
        pci_read_config_byte(pdev, SKX_IMBAR1SZ_OFFSET, &bar_sz);
        dev_dbg(ndev_dev(ndev), "IMBAR1SZ %#x\n", bar_sz);
        if (b2b_bar == 1) {
                if (ndev->b2b_off)
                        bar_sz -= 1;
                else
                        bar_sz = 0;
        }

        pci_write_config_byte(pdev, SKX_EMBAR1SZ_OFFSET, bar_sz);
        pci_read_config_byte(pdev, SKX_EMBAR1SZ_OFFSET, &bar_sz);
        dev_dbg(ndev_dev(ndev), "EMBAR1SZ %#x\n", bar_sz);

        pci_read_config_byte(pdev, SKX_IMBAR2SZ_OFFSET, &bar_sz);
        dev_dbg(ndev_dev(ndev), "IMBAR2SZ %#x\n", bar_sz);
        if (b2b_bar == 2) {
                if (ndev->b2b_off)
                        bar_sz -= 1;
                else
                        bar_sz = 0;
        }

        pci_write_config_byte(pdev, SKX_EMBAR2SZ_OFFSET, bar_sz);
        pci_read_config_byte(pdev, SKX_EMBAR2SZ_OFFSET, &bar_sz);
        dev_dbg(ndev_dev(ndev), "EMBAR2SZ %#x\n", bar_sz);

        /* SBAR01 hit by first part of the b2b bar */
        if (b2b_bar == 0)
                bar_addr = addr->bar0_addr;
        else if (b2b_bar == 1)
                bar_addr = addr->bar2_addr64;
        else if (b2b_bar == 2)
                bar_addr = addr->bar4_addr64;
        else
                return -EIO;

        /* setup incoming bar limits == base addrs (zero length windows) */
        bar_addr = addr->bar2_addr64 + (b2b_bar == 1 ? ndev->b2b_off : 0);
        iowrite64(bar_addr, mmio + SKX_IMBAR1XLMT_OFFSET);
        bar_addr = ioread64(mmio + SKX_IMBAR1XLMT_OFFSET);
        dev_dbg(ndev_dev(ndev), "IMBAR1XLMT %#018llx\n", bar_addr);

        bar_addr = addr->bar4_addr64 + (b2b_bar == 2 ? ndev->b2b_off : 0);
        iowrite64(bar_addr, mmio + SKX_IMBAR2XLMT_OFFSET);
        bar_addr = ioread64(mmio + SKX_IMBAR2XLMT_OFFSET);
        dev_dbg(ndev_dev(ndev), "IMBAR2XLMT %#018llx\n", bar_addr);

        /* zero incoming translation addrs */
        iowrite64(0, mmio + SKX_IMBAR1XBASE_OFFSET);
        iowrite64(0, mmio + SKX_IMBAR2XBASE_OFFSET);

        ndev->peer_mmio = ndev->self_mmio;

        return 0;
}

static int skx_init_ntb(struct intel_ntb_dev *ndev)
{
        int rc;


        ndev->mw_count = XEON_MW_COUNT;
        ndev->spad_count = SKX_SPAD_COUNT;
        ndev->db_count = SKX_DB_COUNT;
        ndev->db_link_mask = SKX_DB_LINK_BIT;

        /* DB fixup for using 31 right now */
        if (ndev->hwerr_flags & NTB_HWERR_MSIX_VECTOR32_BAD)
                ndev->db_link_mask |= BIT_ULL(31);

        switch (ndev->ntb.topo) {
        case NTB_TOPO_B2B_USD:
        case NTB_TOPO_B2B_DSD:
                ndev->self_reg = &skx_pri_reg;
                ndev->peer_reg = &skx_b2b_reg;
                ndev->xlat_reg = &skx_sec_xlat;

                if (ndev->ntb.topo == NTB_TOPO_B2B_USD) {
                        rc = skx_setup_b2b_mw(ndev,
                                              &xeon_b2b_dsd_addr,
                                              &xeon_b2b_usd_addr);
                } else {
                        rc = skx_setup_b2b_mw(ndev,
                                              &xeon_b2b_usd_addr,
                                              &xeon_b2b_dsd_addr);
                }

                if (rc)
                        return rc;

                /* Enable Bus Master and Memory Space on the secondary side */
                iowrite16(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER,
                          ndev->self_mmio + SKX_SPCICMD_OFFSET);

                break;

        default:
                return -EINVAL;
        }

        ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;

        ndev->reg->db_iowrite(ndev->db_valid_mask,
                              ndev->self_mmio +
                              ndev->self_reg->db_mask);

        return 0;
}

static int skx_init_dev(struct intel_ntb_dev *ndev)
{
        struct pci_dev *pdev;
        u8 ppd;
        int rc;

        pdev = ndev_pdev(ndev);

        ndev->reg = &skx_reg;

        rc = pci_read_config_byte(pdev, XEON_PPD_OFFSET, &ppd);
        if (rc)
                return -EIO;

        ndev->ntb.topo = xeon_ppd_topo(ndev, ppd);
        dev_dbg(ndev_dev(ndev), "ppd %#x topo %s\n", ppd,
                ntb_topo_string(ndev->ntb.topo));
        if (ndev->ntb.topo == NTB_TOPO_NONE)
                return -EINVAL;

        if (pdev_is_skx_xeon(pdev))
                ndev->hwerr_flags |= NTB_HWERR_MSIX_VECTOR32_BAD;

        rc = skx_init_ntb(ndev);
        if (rc)
                return rc;

        return skx_init_isr(ndev);
}

static int intel_ntb3_link_enable(struct ntb_dev *ntb,
                                  enum ntb_speed max_speed,
                                  enum ntb_width max_width)
{
        struct intel_ntb_dev *ndev;
        u32 ntb_ctl;

        ndev = container_of(ntb, struct intel_ntb_dev, ntb);

        dev_dbg(ndev_dev(ndev),
                "Enabling link with max_speed %d max_width %d\n",
                max_speed, max_width);

        if (max_speed != NTB_SPEED_AUTO)
                dev_dbg(ndev_dev(ndev), "ignoring max_speed %d\n", max_speed);
        if (max_width != NTB_WIDTH_AUTO)
                dev_dbg(ndev_dev(ndev), "ignoring max_width %d\n", max_width);

        ntb_ctl = ioread32(ndev->self_mmio + ndev->reg->ntb_ctl);
        ntb_ctl &= ~(NTB_CTL_DISABLE | NTB_CTL_CFG_LOCK);
        ntb_ctl |= NTB_CTL_P2S_BAR2_SNOOP | NTB_CTL_S2P_BAR2_SNOOP;
        ntb_ctl |= NTB_CTL_P2S_BAR4_SNOOP | NTB_CTL_S2P_BAR4_SNOOP;
        iowrite32(ntb_ctl, ndev->self_mmio + ndev->reg->ntb_ctl);

        return 0;
}
static int intel_ntb3_mw_set_trans(struct ntb_dev *ntb, int idx,
                                   dma_addr_t addr, resource_size_t size)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);
        unsigned long xlat_reg, limit_reg;
        resource_size_t bar_size, mw_size;
        void __iomem *mmio;
        u64 base, limit, reg_val;
        int bar;

        if (idx >= ndev->b2b_idx && !ndev->b2b_off)
                idx += 1;

        bar = ndev_mw_to_bar(ndev, idx);
        if (bar < 0)
                return bar;

        bar_size = pci_resource_len(ndev->ntb.pdev, bar);

        if (idx == ndev->b2b_idx)
                mw_size = bar_size - ndev->b2b_off;
        else
                mw_size = bar_size;

        /* hardware requires that addr is aligned to bar size */
        if (addr & (bar_size - 1))
                return -EINVAL;

        /* make sure the range fits in the usable mw size */
        if (size > mw_size)
                return -EINVAL;

        mmio = ndev->self_mmio;
        xlat_reg = ndev->xlat_reg->bar2_xlat + (idx * 0x10);
        limit_reg = ndev->xlat_reg->bar2_limit + (idx * 0x10);
        base = pci_resource_start(ndev->ntb.pdev, bar);

        /* Set the limit if supported, if size is not mw_size */
        if (limit_reg && size != mw_size)
                limit = base + size;
        else
                limit = base + mw_size;

        /* set and verify setting the translation address */
        iowrite64(addr, mmio + xlat_reg);
        reg_val = ioread64(mmio + xlat_reg);
        if (reg_val != addr) {
                iowrite64(0, mmio + xlat_reg);
                return -EIO;
        }

        dev_dbg(ndev_dev(ndev), "BAR %d IMBARXBASE: %#Lx\n", bar, reg_val);

        /* set and verify setting the limit */
        iowrite64(limit, mmio + limit_reg);
        reg_val = ioread64(mmio + limit_reg);
        if (reg_val != limit) {
                iowrite64(base, mmio + limit_reg);
                iowrite64(0, mmio + xlat_reg);
                return -EIO;
        }

        dev_dbg(ndev_dev(ndev), "BAR %d IMBARXLMT: %#Lx\n", bar, reg_val);

        /* setup the EP */
        limit_reg = ndev->xlat_reg->bar2_limit + (idx * 0x10) + 0x4000;
        base = ioread64(mmio + SKX_EMBAR1_OFFSET + (8 * idx));
        base &= ~0xf;

        if (limit_reg && size != mw_size)
                limit = base + size;
        else
                limit = base + mw_size;

        /* set and verify setting the limit */
        iowrite64(limit, mmio + limit_reg);
        reg_val = ioread64(mmio + limit_reg);
        if (reg_val != limit) {
                iowrite64(base, mmio + limit_reg);
                iowrite64(0, mmio + xlat_reg);
                return -EIO;
        }

        dev_dbg(ndev_dev(ndev), "BAR %d EMBARXLMT: %#Lx\n", bar, reg_val);

        return 0;
}

static int intel_ntb3_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);
        int bit;

        if (db_bits & ~ndev->db_valid_mask)
                return -EINVAL;

        while (db_bits) {
                bit = __ffs(db_bits);
                iowrite32(1, ndev->peer_mmio +
                                ndev->peer_reg->db_bell + (bit * 4));
                db_bits &= db_bits - 1;
        }

        return 0;
}

static u64 intel_ntb3_db_read(struct ntb_dev *ntb)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        return ndev_db_read(ndev,
                            ndev->self_mmio +
                            ndev->self_reg->db_clear);
}

static int intel_ntb3_db_clear(struct ntb_dev *ntb, u64 db_bits)
{
        struct intel_ntb_dev *ndev = ntb_ndev(ntb);

        return ndev_db_write(ndev, db_bits,
                             ndev->self_mmio +
                             ndev->self_reg->db_clear);
}

/* XEON */

static u64 xeon_db_ioread(void __iomem *mmio)
{
        return (u64)ioread16(mmio);
}

static void xeon_db_iowrite(u64 bits, void __iomem *mmio)
{
        iowrite16((u16)bits, mmio);
}

static int xeon_poll_link(struct intel_ntb_dev *ndev)
{
        u16 reg_val;
        int rc;

        ndev->reg->db_iowrite(ndev->db_link_mask,
                              ndev->self_mmio +
                              ndev->self_reg->db_bell);

        rc = pci_read_config_word(ndev->ntb.pdev,
                                  XEON_LINK_STATUS_OFFSET, &reg_val);
        if (rc)
                return 0;

        if (reg_val == ndev->lnk_sta)
                return 0;

        ndev->lnk_sta = reg_val;

        return 1;
}

static int xeon_link_is_up(struct intel_ntb_dev *ndev)
{
        if (ndev->ntb.topo == NTB_TOPO_SEC)
                return 1;

        return NTB_LNK_STA_ACTIVE(ndev->lnk_sta);
}

static inline enum ntb_topo xeon_ppd_topo(struct intel_ntb_dev *ndev, u8 ppd)
{
        switch (ppd & XEON_PPD_TOPO_MASK) {
        case XEON_PPD_TOPO_B2B_USD:
                return NTB_TOPO_B2B_USD;

        case XEON_PPD_TOPO_B2B_DSD:
                return NTB_TOPO_B2B_DSD;

        case XEON_PPD_TOPO_PRI_USD:
        case XEON_PPD_TOPO_PRI_DSD: /* accept bogus PRI_DSD */
                return NTB_TOPO_PRI;

        case XEON_PPD_TOPO_SEC_USD:
        case XEON_PPD_TOPO_SEC_DSD: /* accept bogus SEC_DSD */
                return NTB_TOPO_SEC;
        }

        return NTB_TOPO_NONE;
}

static inline int xeon_ppd_bar4_split(struct intel_ntb_dev *ndev, u8 ppd)
{
        if (ppd & XEON_PPD_SPLIT_BAR_MASK) {
                dev_dbg(ndev_dev(ndev), "PPD %d split bar\n", ppd);
                return 1;
        }
        return 0;
}

static int xeon_init_isr(struct intel_ntb_dev *ndev)
{
        return ndev_init_isr(ndev, XEON_DB_MSIX_VECTOR_COUNT,
                             XEON_DB_MSIX_VECTOR_COUNT,
                             XEON_DB_MSIX_VECTOR_SHIFT,
                             XEON_DB_TOTAL_SHIFT);
}

static void xeon_deinit_isr(struct intel_ntb_dev *ndev)
{
        ndev_deinit_isr(ndev);
}

static int xeon_setup_b2b_mw(struct intel_ntb_dev *ndev,
                             const struct intel_b2b_addr *addr,
                             const struct intel_b2b_addr *peer_addr)
{
        struct pci_dev *pdev;
        void __iomem *mmio;
        resource_size_t bar_size;
        phys_addr_t bar_addr;
        int b2b_bar;
        u8 bar_sz;

        pdev = ndev_pdev(ndev);
        mmio = ndev->self_mmio;

        if (ndev->b2b_idx == UINT_MAX) {
                dev_dbg(ndev_dev(ndev), "not using b2b mw\n");
                b2b_bar = 0;
                ndev->b2b_off = 0;
        } else {
                b2b_bar = ndev_mw_to_bar(ndev, ndev->b2b_idx);
                if (b2b_bar < 0)
                        return -EIO;

                dev_dbg(ndev_dev(ndev), "using b2b mw bar %d\n", b2b_bar);

                bar_size = pci_resource_len(ndev->ntb.pdev, b2b_bar);

                dev_dbg(ndev_dev(ndev), "b2b bar size %#llx\n", bar_size);

                if (b2b_mw_share && XEON_B2B_MIN_SIZE <= bar_size >> 1) {
                        dev_dbg(ndev_dev(ndev),
                                "b2b using first half of bar\n");
                        ndev->b2b_off = bar_size >> 1;
                } else if (XEON_B2B_MIN_SIZE <= bar_size) {
                        dev_dbg(ndev_dev(ndev),
                                "b2b using whole bar\n");
                        ndev->b2b_off = 0;
                        --ndev->mw_count;
                } else {
                        dev_dbg(ndev_dev(ndev),
                                "b2b bar size is too small\n");
                        return -EIO;
                }
        }

        /* Reset the secondary bar sizes to match the primary bar sizes,
         * except disable or halve the size of the b2b secondary bar.
         *
         * Note: code for each specific bar size register, because the register
         * offsets are not in a consistent order (bar5sz comes after ppd, odd).
         */
        pci_read_config_byte(pdev, XEON_PBAR23SZ_OFFSET, &bar_sz);
        dev_dbg(ndev_dev(ndev), "PBAR23SZ %#x\n", bar_sz);
        if (b2b_bar == 2) {
                if (ndev->b2b_off)
                        bar_sz -= 1;
                else
                        bar_sz = 0;
        }
        pci_write_config_byte(pdev, XEON_SBAR23SZ_OFFSET, bar_sz);
        pci_read_config_byte(pdev, XEON_SBAR23SZ_OFFSET, &bar_sz);
        dev_dbg(ndev_dev(ndev), "SBAR23SZ %#x\n", bar_sz);

        if (!ndev->bar4_split) {
                pci_read_config_byte(pdev, XEON_PBAR45SZ_OFFSET, &bar_sz);
                dev_dbg(ndev_dev(ndev), "PBAR45SZ %#x\n", bar_sz);
                if (b2b_bar == 4) {
                        if (ndev->b2b_off)
                                bar_sz -= 1;
                        else
                                bar_sz = 0;
                }
                pci_write_config_byte(pdev, XEON_SBAR45SZ_OFFSET, bar_sz);
                pci_read_config_byte(pdev, XEON_SBAR45SZ_OFFSET, &bar_sz);
                dev_dbg(ndev_dev(ndev), "SBAR45SZ %#x\n", bar_sz);
        } else {
                pci_read_config_byte(pdev, XEON_PBAR4SZ_OFFSET, &bar_sz);
                dev_dbg(ndev_dev(ndev), "PBAR4SZ %#x\n", bar_sz);
                if (b2b_bar == 4) {
                        if (ndev->b2b_off)
                                bar_sz -= 1;
                        else
                                bar_sz = 0;
                }
                pci_write_config_byte(pdev, XEON_SBAR4SZ_OFFSET, bar_sz);
                pci_read_config_byte(pdev, XEON_SBAR4SZ_OFFSET, &bar_sz);
                dev_dbg(ndev_dev(ndev), "SBAR4SZ %#x\n", bar_sz);

                pci_read_config_byte(pdev, XEON_PBAR5SZ_OFFSET, &bar_sz);
                dev_dbg(ndev_dev(ndev), "PBAR5SZ %#x\n", bar_sz);
                if (b2b_bar == 5) {
                        if (ndev->b2b_off)
                                bar_sz -= 1;
                        else
                                bar_sz = 0;
                }
                pci_write_config_byte(pdev, XEON_SBAR5SZ_OFFSET, bar_sz);
                pci_read_config_byte(pdev, XEON_SBAR5SZ_OFFSET, &bar_sz);
                dev_dbg(ndev_dev(ndev), "SBAR5SZ %#x\n", bar_sz);
        }

        /* SBAR01 hit by first part of the b2b bar */
        if (b2b_bar == 0)
                bar_addr = addr->bar0_addr;
        else if (b2b_bar == 2)
                bar_addr = addr->bar2_addr64;
        else if (b2b_bar == 4 && !ndev->bar4_split)
                bar_addr = addr->bar4_addr64;
        else if (b2b_bar == 4)
                bar_addr = addr->bar4_addr32;
        else if (b2b_bar == 5)
                bar_addr = addr->bar5_addr32;
        else
                return -EIO;

        dev_dbg(ndev_dev(ndev), "SBAR01 %#018llx\n", bar_addr);
        iowrite64(bar_addr, mmio + XEON_SBAR0BASE_OFFSET);

        /* Other SBAR are normally hit by the PBAR xlat, except for b2b bar.
         * The b2b bar is either disabled above, or configured half-size, and
         * it starts at the PBAR xlat + offset.
         */

        bar_addr = addr->bar2_addr64 + (b2b_bar == 2 ? ndev->b2b_off : 0);
        iowrite64(bar_addr, mmio + XEON_SBAR23BASE_OFFSET);
        bar_addr = ioread64(mmio + XEON_SBAR23BASE_OFFSET);
        dev_dbg(ndev_dev(ndev), "SBAR23 %#018llx\n", bar_addr);

        if (!ndev->bar4_split) {
                bar_addr = addr->bar4_addr64 +
                        (b2b_bar == 4 ? ndev->b2b_off : 0);
                iowrite64(bar_addr, mmio + XEON_SBAR45BASE_OFFSET);
                bar_addr = ioread64(mmio + XEON_SBAR45BASE_OFFSET);
                dev_dbg(ndev_dev(ndev), "SBAR45 %#018llx\n", bar_addr);
        } else {
                bar_addr = addr->bar4_addr32 +
                        (b2b_bar == 4 ? ndev->b2b_off : 0);
                iowrite32(bar_addr, mmio + XEON_SBAR4BASE_OFFSET);
                bar_addr = ioread32(mmio + XEON_SBAR4BASE_OFFSET);
                dev_dbg(ndev_dev(ndev), "SBAR4 %#010llx\n", bar_addr);

                bar_addr = addr->bar5_addr32 +
                        (b2b_bar == 5 ? ndev->b2b_off : 0);
                iowrite32(bar_addr, mmio + XEON_SBAR5BASE_OFFSET);
                bar_addr = ioread32(mmio + XEON_SBAR5BASE_OFFSET);
                dev_dbg(ndev_dev(ndev), "SBAR5 %#010llx\n", bar_addr);
        }

        /* setup incoming bar limits == base addrs (zero length windows) */

        bar_addr = addr->bar2_addr64 + (b2b_bar == 2 ? ndev->b2b_off : 0);
        iowrite64(bar_addr, mmio + XEON_SBAR23LMT_OFFSET);
        bar_addr = ioread64(mmio + XEON_SBAR23LMT_OFFSET);
        dev_dbg(ndev_dev(ndev), "SBAR23LMT %#018llx\n", bar_addr);

        if (!ndev->bar4_split) {
                bar_addr = addr->bar4_addr64 +
                        (b2b_bar == 4 ? ndev->b2b_off : 0);
                iowrite64(bar_addr, mmio + XEON_SBAR45LMT_OFFSET);
                bar_addr = ioread64(mmio + XEON_SBAR45LMT_OFFSET);
                dev_dbg(ndev_dev(ndev), "SBAR45LMT %#018llx\n", bar_addr);
        } else {
                bar_addr = addr->bar4_addr32 +
                        (b2b_bar == 4 ? ndev->b2b_off : 0);
                iowrite32(bar_addr, mmio + XEON_SBAR4LMT_OFFSET);
                bar_addr = ioread32(mmio + XEON_SBAR4LMT_OFFSET);
                dev_dbg(ndev_dev(ndev), "SBAR4LMT %#010llx\n", bar_addr);

                bar_addr = addr->bar5_addr32 +
                        (b2b_bar == 5 ? ndev->b2b_off : 0);
                iowrite32(bar_addr, mmio + XEON_SBAR5LMT_OFFSET);
                bar_addr = ioread32(mmio + XEON_SBAR5LMT_OFFSET);
                dev_dbg(ndev_dev(ndev), "SBAR5LMT %#05llx\n", bar_addr);
        }

        /* zero incoming translation addrs */
        iowrite64(0, mmio + XEON_SBAR23XLAT_OFFSET);

        if (!ndev->bar4_split) {
                iowrite64(0, mmio + XEON_SBAR45XLAT_OFFSET);
        } else {
                iowrite32(0, mmio + XEON_SBAR4XLAT_OFFSET);
                iowrite32(0, mmio + XEON_SBAR5XLAT_OFFSET);
        }

        /* zero outgoing translation limits (whole bar size windows) */
        iowrite64(0, mmio + XEON_PBAR23LMT_OFFSET);
        if (!ndev->bar4_split) {
                iowrite64(0, mmio + XEON_PBAR45LMT_OFFSET);
        } else {
                iowrite32(0, mmio + XEON_PBAR4LMT_OFFSET);
                iowrite32(0, mmio + XEON_PBAR5LMT_OFFSET);
        }

        /* set outgoing translation offsets */
        bar_addr = peer_addr->bar2_addr64;
        iowrite64(bar_addr, mmio + XEON_PBAR23XLAT_OFFSET);
        bar_addr = ioread64(mmio + XEON_PBAR23XLAT_OFFSET);
        dev_dbg(ndev_dev(ndev), "PBAR23XLAT %#018llx\n", bar_addr);

        if (!ndev->bar4_split) {
                bar_addr = peer_addr->bar4_addr64;
                iowrite64(bar_addr, mmio + XEON_PBAR45XLAT_OFFSET);
                bar_addr = ioread64(mmio + XEON_PBAR45XLAT_OFFSET);
                dev_dbg(ndev_dev(ndev), "PBAR45XLAT %#018llx\n", bar_addr);
        } else {
                bar_addr = peer_addr->bar4_addr32;
                iowrite32(bar_addr, mmio + XEON_PBAR4XLAT_OFFSET);
                bar_addr = ioread32(mmio + XEON_PBAR4XLAT_OFFSET);
                dev_dbg(ndev_dev(ndev), "PBAR4XLAT %#010llx\n", bar_addr);

                bar_addr = peer_addr->bar5_addr32;
                iowrite32(bar_addr, mmio + XEON_PBAR5XLAT_OFFSET);
                bar_addr = ioread32(mmio + XEON_PBAR5XLAT_OFFSET);
                dev_dbg(ndev_dev(ndev), "PBAR5XLAT %#010llx\n", bar_addr);
        }

        /* set the translation offset for b2b registers */
        if (b2b_bar == 0)
                bar_addr = peer_addr->bar0_addr;
        else if (b2b_bar == 2)
                bar_addr = peer_addr->bar2_addr64;
        else if (b2b_bar == 4 && !ndev->bar4_split)
                bar_addr = peer_addr->bar4_addr64;
        else if (b2b_bar == 4)
                bar_addr = peer_addr->bar4_addr32;
        else if (b2b_bar == 5)
                bar_addr = peer_addr->bar5_addr32;
        else
                return -EIO;

        /* B2B_XLAT_OFFSET is 64bit, but can only take 32bit writes */
        dev_dbg(ndev_dev(ndev), "B2BXLAT %#018llx\n", bar_addr);
        iowrite32(bar_addr, mmio + XEON_B2B_XLAT_OFFSETL);
        iowrite32(bar_addr >> 32, mmio + XEON_B2B_XLAT_OFFSETU);

        if (b2b_bar) {
                /* map peer ntb mmio config space registers */
                ndev->peer_mmio = pci_iomap(pdev, b2b_bar,
                                            XEON_B2B_MIN_SIZE);
                if (!ndev->peer_mmio)
                        return -EIO;

                ndev->peer_addr = pci_resource_start(pdev, b2b_bar);
        }

        return 0;
}

static int xeon_init_ntb(struct intel_ntb_dev *ndev)
{
        int rc;
        u32 ntb_ctl;

        if (ndev->bar4_split)
                ndev->mw_count = HSX_SPLIT_BAR_MW_COUNT;
        else
                ndev->mw_count = XEON_MW_COUNT;

        ndev->spad_count = XEON_SPAD_COUNT;
        ndev->db_count = XEON_DB_COUNT;
        ndev->db_link_mask = XEON_DB_LINK_BIT;

        switch (ndev->ntb.topo) {
        case NTB_TOPO_PRI:
                if (ndev->hwerr_flags & NTB_HWERR_SDOORBELL_LOCKUP) {
                        dev_err(ndev_dev(ndev), "NTB Primary config disabled\n");
                        return -EINVAL;
                }

                /* enable link to allow secondary side device to appear */
                ntb_ctl = ioread32(ndev->self_mmio + ndev->reg->ntb_ctl);
                ntb_ctl &= ~NTB_CTL_DISABLE;
                iowrite32(ntb_ctl, ndev->self_mmio + ndev->reg->ntb_ctl);

                /* use half the spads for the peer */
                ndev->spad_count >>= 1;
                ndev->self_reg = &xeon_pri_reg;
                ndev->peer_reg = &xeon_sec_reg;
                ndev->xlat_reg = &xeon_sec_xlat;
                break;

        case NTB_TOPO_SEC:
                if (ndev->hwerr_flags & NTB_HWERR_SDOORBELL_LOCKUP) {
                        dev_err(ndev_dev(ndev), "NTB Secondary config disabled\n");
                        return -EINVAL;
                }
                /* use half the spads for the peer */
                ndev->spad_count >>= 1;
                ndev->self_reg = &xeon_sec_reg;
                ndev->peer_reg = &xeon_pri_reg;
                ndev->xlat_reg = &xeon_pri_xlat;
                break;

        case NTB_TOPO_B2B_USD:
        case NTB_TOPO_B2B_DSD:
                ndev->self_reg = &xeon_pri_reg;
                ndev->peer_reg = &xeon_b2b_reg;
                ndev->xlat_reg = &xeon_sec_xlat;

                if (ndev->hwerr_flags & NTB_HWERR_SDOORBELL_LOCKUP) {
                        ndev->peer_reg = &xeon_pri_reg;

                        if (b2b_mw_idx < 0)
                                ndev->b2b_idx = b2b_mw_idx + ndev->mw_count;
                        else
                                ndev->b2b_idx = b2b_mw_idx;

                        if (ndev->b2b_idx >= ndev->mw_count) {
                                dev_dbg(ndev_dev(ndev),
                                        "b2b_mw_idx %d invalid for mw_count %u\n",
                                        b2b_mw_idx, ndev->mw_count);
                                return -EINVAL;
                        }

                        dev_dbg(ndev_dev(ndev),
                                "setting up b2b mw idx %d means %d\n",
                                b2b_mw_idx, ndev->b2b_idx);

                } else if (ndev->hwerr_flags & NTB_HWERR_B2BDOORBELL_BIT14) {
                        dev_warn(ndev_dev(ndev), "Reduce doorbell count by 1\n");
                        ndev->db_count -= 1;
                }

                if (ndev->ntb.topo == NTB_TOPO_B2B_USD) {
                        rc = xeon_setup_b2b_mw(ndev,
                                               &xeon_b2b_dsd_addr,
                                               &xeon_b2b_usd_addr);
                } else {
                        rc = xeon_setup_b2b_mw(ndev,
                                               &xeon_b2b_usd_addr,
                                               &xeon_b2b_dsd_addr);
                }
                if (rc)
                        return rc;

                /* Enable Bus Master and Memory Space on the secondary side */
                iowrite16(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER,
                          ndev->self_mmio + XEON_SPCICMD_OFFSET);

                break;

        default:
                return -EINVAL;
        }

        ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;

        ndev->reg->db_iowrite(ndev->db_valid_mask,
                              ndev->self_mmio +
                              ndev->self_reg->db_mask);

        return 0;
}

static int xeon_init_dev(struct intel_ntb_dev *ndev)
{
        struct pci_dev *pdev;
        u8 ppd;
        int rc, mem;

        pdev = ndev_pdev(ndev);

        switch (pdev->device) {
        /* There is a Xeon hardware errata related to writes to SDOORBELL or
         * B2BDOORBELL in conjunction with inbound access to NTB MMIO Space,
         * which may hang the system.  To workaround this use the second memory
         * window to access the interrupt and scratch pad registers on the
         * remote system.
         */
        case PCI_DEVICE_ID_INTEL_NTB_SS_JSF:
        case PCI_DEVICE_ID_INTEL_NTB_PS_JSF:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_JSF:
        case PCI_DEVICE_ID_INTEL_NTB_SS_SNB:
        case PCI_DEVICE_ID_INTEL_NTB_PS_SNB:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_SNB:
        case PCI_DEVICE_ID_INTEL_NTB_SS_IVT:
        case PCI_DEVICE_ID_INTEL_NTB_PS_IVT:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_IVT:
        case PCI_DEVICE_ID_INTEL_NTB_SS_HSX:
        case PCI_DEVICE_ID_INTEL_NTB_PS_HSX:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_HSX:
        case PCI_DEVICE_ID_INTEL_NTB_SS_BDX:
        case PCI_DEVICE_ID_INTEL_NTB_PS_BDX:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_BDX:
                ndev->hwerr_flags |= NTB_HWERR_SDOORBELL_LOCKUP;
                break;
        }

        switch (pdev->device) {
        /* There is a hardware errata related to accessing any register in
         * SB01BASE in the presence of bidirectional traffic crossing the NTB.
         */
        case PCI_DEVICE_ID_INTEL_NTB_SS_IVT:
        case PCI_DEVICE_ID_INTEL_NTB_PS_IVT:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_IVT:
        case PCI_DEVICE_ID_INTEL_NTB_SS_HSX:
        case PCI_DEVICE_ID_INTEL_NTB_PS_HSX:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_HSX:
        case PCI_DEVICE_ID_INTEL_NTB_SS_BDX:
        case PCI_DEVICE_ID_INTEL_NTB_PS_BDX:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_BDX:
                ndev->hwerr_flags |= NTB_HWERR_SB01BASE_LOCKUP;
                break;
        }

        switch (pdev->device) {
        /* HW Errata on bit 14 of b2bdoorbell register.  Writes will not be
         * mirrored to the remote system.  Shrink the number of bits by one,
         * since bit 14 is the last bit.
         */
        case PCI_DEVICE_ID_INTEL_NTB_SS_JSF:
        case PCI_DEVICE_ID_INTEL_NTB_PS_JSF:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_JSF:
        case PCI_DEVICE_ID_INTEL_NTB_SS_SNB:
        case PCI_DEVICE_ID_INTEL_NTB_PS_SNB:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_SNB:
        case PCI_DEVICE_ID_INTEL_NTB_SS_IVT:
        case PCI_DEVICE_ID_INTEL_NTB_PS_IVT:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_IVT:
        case PCI_DEVICE_ID_INTEL_NTB_SS_HSX:
        case PCI_DEVICE_ID_INTEL_NTB_PS_HSX:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_HSX:
        case PCI_DEVICE_ID_INTEL_NTB_SS_BDX:
        case PCI_DEVICE_ID_INTEL_NTB_PS_BDX:
        case PCI_DEVICE_ID_INTEL_NTB_B2B_BDX:
                ndev->hwerr_flags |= NTB_HWERR_B2BDOORBELL_BIT14;
                break;
        }

        ndev->reg = &xeon_reg;

        rc = pci_read_config_byte(pdev, XEON_PPD_OFFSET, &ppd);
        if (rc)
                return -EIO;

        ndev->ntb.topo = xeon_ppd_topo(ndev, ppd);
        dev_dbg(ndev_dev(ndev), "ppd %#x topo %s\n", ppd,
                ntb_topo_string(ndev->ntb.topo));
        if (ndev->ntb.topo == NTB_TOPO_NONE)
                return -EINVAL;

        if (ndev->ntb.topo != NTB_TOPO_SEC) {
                ndev->bar4_split = xeon_ppd_bar4_split(ndev, ppd);
                dev_dbg(ndev_dev(ndev), "ppd %#x bar4_split %d\n",
                        ppd, ndev->bar4_split);
        } else {
                /* This is a way for transparent BAR to figure out if we are
                 * doing split BAR or not. There is no way for the hw on the
                 * transparent side to know and set the PPD.
                 */
                mem = pci_select_bars(pdev, IORESOURCE_MEM);
                ndev->bar4_split = hweight32(mem) ==
                        HSX_SPLIT_BAR_MW_COUNT + 1;
                dev_dbg(ndev_dev(ndev), "mem %#x bar4_split %d\n",
                        mem, ndev->bar4_split);
        }

        rc = xeon_init_ntb(ndev);
        if (rc)
                return rc;

        return xeon_init_isr(ndev);
}

static void xeon_deinit_dev(struct intel_ntb_dev *ndev)
{
        xeon_deinit_isr(ndev);
}

static int intel_ntb_init_pci(struct intel_ntb_dev *ndev, struct pci_dev *pdev)
{
        int rc;

        pci_set_drvdata(pdev, ndev);

        rc = pci_enable_device(pdev);
        if (rc)
                goto err_pci_enable;

        rc = pci_request_regions(pdev, NTB_NAME);
        if (rc)
                goto err_pci_regions;

        pci_set_master(pdev);

        rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
        if (rc) {
                rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
                if (rc)
                        goto err_dma_mask;
                dev_warn(ndev_dev(ndev), "Cannot DMA highmem\n");
        }

        rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
        if (rc) {
                rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32));
                if (rc)
                        goto err_dma_mask;
                dev_warn(ndev_dev(ndev), "Cannot DMA consistent highmem\n");
        }

        ndev->self_mmio = pci_iomap(pdev, 0, 0);
        if (!ndev->self_mmio) {
                rc = -EIO;
                goto err_mmio;
        }
        ndev->peer_mmio = ndev->self_mmio;
        ndev->peer_addr = pci_resource_start(pdev, 0);

        return 0;

err_mmio:
err_dma_mask:
        pci_clear_master(pdev);
        pci_release_regions(pdev);
err_pci_regions:
        pci_disable_device(pdev);
err_pci_enable:
        pci_set_drvdata(pdev, NULL);
        return rc;
}

static void intel_ntb_deinit_pci(struct intel_ntb_dev *ndev)
{
        struct pci_dev *pdev = ndev_pdev(ndev);

        if (ndev->peer_mmio && ndev->peer_mmio != ndev->self_mmio)
                pci_iounmap(pdev, ndev->peer_mmio);
        pci_iounmap(pdev, ndev->self_mmio);

        pci_clear_master(pdev);
        pci_release_regions(pdev);
        pci_disable_device(pdev);
        pci_set_drvdata(pdev, NULL);
}

static inline void ndev_init_struct(struct intel_ntb_dev *ndev,
                                    struct pci_dev *pdev)
{
        ndev->ntb.pdev = pdev;
        ndev->ntb.topo = NTB_TOPO_NONE;
        ndev->ntb.ops = &intel_ntb_ops;

        ndev->b2b_off = 0;
        ndev->b2b_idx = UINT_MAX;

        ndev->bar4_split = 0;

        ndev->mw_count = 0;
        ndev->spad_count = 0;
        ndev->db_count = 0;
        ndev->db_vec_count = 0;
        ndev->db_vec_shift = 0;

        ndev->ntb_ctl = 0;
        ndev->lnk_sta = 0;

        ndev->db_valid_mask = 0;
        ndev->db_link_mask = 0;
        ndev->db_mask = 0;

        spin_lock_init(&ndev->db_mask_lock);
}

static int intel_ntb_pci_probe(struct pci_dev *pdev,
                               const struct pci_device_id *id)
{
        struct intel_ntb_dev *ndev;
        int rc, node;

        node = dev_to_node(&pdev->dev);

        if (pdev_is_atom(pdev)) {
                ndev = kzalloc_node(sizeof(*ndev), GFP_KERNEL, node);
                if (!ndev) {
                        rc = -ENOMEM;
                        goto err_ndev;
                }

                ndev_init_struct(ndev, pdev);

                rc = intel_ntb_init_pci(ndev, pdev);
                if (rc)
                        goto err_init_pci;

                rc = atom_init_dev(ndev);
                if (rc)
                        goto err_init_dev;

        } else if (pdev_is_xeon(pdev)) {
                ndev = kzalloc_node(sizeof(*ndev), GFP_KERNEL, node);
                if (!ndev) {
                        rc = -ENOMEM;
                        goto err_ndev;
                }

                ndev_init_struct(ndev, pdev);

                rc = intel_ntb_init_pci(ndev, pdev);
                if (rc)
                        goto err_init_pci;

                rc = xeon_init_dev(ndev);
                if (rc)
                        goto err_init_dev;

        } else if (pdev_is_skx_xeon(pdev)) {
                ndev = kzalloc_node(sizeof(*ndev), GFP_KERNEL, node);
                if (!ndev) {
                        rc = -ENOMEM;
                        goto err_ndev;
                }

                ndev_init_struct(ndev, pdev);
                ndev->ntb.ops = &intel_ntb3_ops;

                rc = intel_ntb_init_pci(ndev, pdev);
                if (rc)
                        goto err_init_pci;

                rc = skx_init_dev(ndev);
                if (rc)
                        goto err_init_dev;

        } else {
                rc = -EINVAL;
                goto err_ndev;
        }

        ndev_reset_unsafe_flags(ndev);

        ndev->reg->poll_link(ndev);

        ndev_init_debugfs(ndev);

        rc = ntb_register_device(&ndev->ntb);
        if (rc)
                goto err_register;

        dev_info(&pdev->dev, "NTB device registered.\n");

        return 0;

err_register:
        ndev_deinit_debugfs(ndev);
        if (pdev_is_atom(pdev))
                atom_deinit_dev(ndev);
        else if (pdev_is_xeon(pdev) || pdev_is_skx_xeon(pdev))
                xeon_deinit_dev(ndev);
err_init_dev:
        intel_ntb_deinit_pci(ndev);
err_init_pci:
        kfree(ndev);
err_ndev:
        return rc;
}

static void intel_ntb_pci_remove(struct pci_dev *pdev)
{
        struct intel_ntb_dev *ndev = pci_get_drvdata(pdev);

        ntb_unregister_device(&ndev->ntb);
        ndev_deinit_debugfs(ndev);
        if (pdev_is_atom(pdev))
                atom_deinit_dev(ndev);
        else if (pdev_is_xeon(pdev) || pdev_is_skx_xeon(pdev))
                xeon_deinit_dev(ndev);
        intel_ntb_deinit_pci(ndev);
        kfree(ndev);
}

static const struct intel_ntb_reg atom_reg = {
        .poll_link              = atom_poll_link,
        .link_is_up             = atom_link_is_up,
        .db_ioread              = atom_db_ioread,
        .db_iowrite             = atom_db_iowrite,
        .db_size                = sizeof(u64),
        .ntb_ctl                = ATOM_NTBCNTL_OFFSET,
        .mw_bar                 = {2, 4},
};

static const struct intel_ntb_alt_reg atom_pri_reg = {
        .db_bell                = ATOM_PDOORBELL_OFFSET,
        .db_mask                = ATOM_PDBMSK_OFFSET,
        .spad                   = ATOM_SPAD_OFFSET,
};

static const struct intel_ntb_alt_reg atom_b2b_reg = {
        .db_bell                = ATOM_B2B_DOORBELL_OFFSET,
        .spad                   = ATOM_B2B_SPAD_OFFSET,
};

static const struct intel_ntb_xlat_reg atom_sec_xlat = {
        /* FIXME : .bar0_base   = ATOM_SBAR0BASE_OFFSET, */
        /* FIXME : .bar2_limit  = ATOM_SBAR2LMT_OFFSET, */
        .bar2_xlat              = ATOM_SBAR2XLAT_OFFSET,
};

static const struct intel_ntb_reg xeon_reg = {
        .poll_link              = xeon_poll_link,
        .link_is_up             = xeon_link_is_up,
        .db_ioread              = xeon_db_ioread,
        .db_iowrite             = xeon_db_iowrite,
        .db_size                = sizeof(u32),
        .ntb_ctl                = XEON_NTBCNTL_OFFSET,
        .mw_bar                 = {2, 4, 5},
};

static const struct intel_ntb_alt_reg xeon_pri_reg = {
        .db_bell                = XEON_PDOORBELL_OFFSET,
        .db_mask                = XEON_PDBMSK_OFFSET,
        .spad                   = XEON_SPAD_OFFSET,
};

static const struct intel_ntb_alt_reg xeon_sec_reg = {
        .db_bell                = XEON_SDOORBELL_OFFSET,
        .db_mask                = XEON_SDBMSK_OFFSET,
        /* second half of the scratchpads */
        .spad                   = XEON_SPAD_OFFSET + (XEON_SPAD_COUNT << 1),
};

static const struct intel_ntb_alt_reg xeon_b2b_reg = {
        .db_bell                = XEON_B2B_DOORBELL_OFFSET,
        .spad                   = XEON_B2B_SPAD_OFFSET,
};

static const struct intel_ntb_xlat_reg xeon_pri_xlat = {
        /* Note: no primary .bar0_base visible to the secondary side.
         *
         * The secondary side cannot get the base address stored in primary
         * bars.  The base address is necessary to set the limit register to
         * any value other than zero, or unlimited.
         *
         * WITHOUT THE BASE ADDRESS, THE SECONDARY SIDE CANNOT DISABLE the
         * window by setting the limit equal to base, nor can it limit the size
         * of the memory window by setting the limit to base + size.
         */
        .bar2_limit             = XEON_PBAR23LMT_OFFSET,
        .bar2_xlat              = XEON_PBAR23XLAT_OFFSET,
};

static const struct intel_ntb_xlat_reg xeon_sec_xlat = {
        .bar0_base              = XEON_SBAR0BASE_OFFSET,
        .bar2_limit             = XEON_SBAR23LMT_OFFSET,
        .bar2_xlat              = XEON_SBAR23XLAT_OFFSET,
};

static struct intel_b2b_addr xeon_b2b_usd_addr = {
        .bar2_addr64            = XEON_B2B_BAR2_ADDR64,
        .bar4_addr64            = XEON_B2B_BAR4_ADDR64,
        .bar4_addr32            = XEON_B2B_BAR4_ADDR32,
        .bar5_addr32            = XEON_B2B_BAR5_ADDR32,
};

static struct intel_b2b_addr xeon_b2b_dsd_addr = {
        .bar2_addr64            = XEON_B2B_BAR2_ADDR64,
        .bar4_addr64            = XEON_B2B_BAR4_ADDR64,
        .bar4_addr32            = XEON_B2B_BAR4_ADDR32,
        .bar5_addr32            = XEON_B2B_BAR5_ADDR32,
};

static const struct intel_ntb_reg skx_reg = {
        .poll_link              = skx_poll_link,
        .link_is_up             = xeon_link_is_up,
        .db_ioread              = skx_db_ioread,
        .db_iowrite             = skx_db_iowrite,
        .db_size                = sizeof(u32),
        .ntb_ctl                = SKX_NTBCNTL_OFFSET,
        .mw_bar                 = {2, 4},
};

static const struct intel_ntb_alt_reg skx_pri_reg = {
        .db_bell                = SKX_EM_DOORBELL_OFFSET,
        .db_clear               = SKX_IM_INT_STATUS_OFFSET,
        .db_mask                = SKX_IM_INT_DISABLE_OFFSET,
        .spad                   = SKX_IM_SPAD_OFFSET,
};

static const struct intel_ntb_alt_reg skx_b2b_reg = {
        .db_bell                = SKX_IM_DOORBELL_OFFSET,
        .db_clear               = SKX_EM_INT_STATUS_OFFSET,
        .db_mask                = SKX_EM_INT_DISABLE_OFFSET,
        .spad                   = SKX_B2B_SPAD_OFFSET,
};

static const struct intel_ntb_xlat_reg skx_sec_xlat = {
/*      .bar0_base              = SKX_EMBAR0_OFFSET, */
        .bar2_limit             = SKX_IMBAR1XLMT_OFFSET,
        .bar2_xlat              = SKX_IMBAR1XBASE_OFFSET,
};

/* operations for primary side of local ntb */
static const struct ntb_dev_ops intel_ntb_ops = {
        .mw_count               = intel_ntb_mw_count,
        .mw_get_range           = intel_ntb_mw_get_range,
        .mw_set_trans           = intel_ntb_mw_set_trans,
        .link_is_up             = intel_ntb_link_is_up,
        .link_enable            = intel_ntb_link_enable,
        .link_disable           = intel_ntb_link_disable,
        .db_is_unsafe           = intel_ntb_db_is_unsafe,
        .db_valid_mask          = intel_ntb_db_valid_mask,
        .db_vector_count        = intel_ntb_db_vector_count,
        .db_vector_mask         = intel_ntb_db_vector_mask,
        .db_read                = intel_ntb_db_read,
        .db_clear               = intel_ntb_db_clear,
        .db_set_mask            = intel_ntb_db_set_mask,
        .db_clear_mask          = intel_ntb_db_clear_mask,
        .peer_db_addr           = intel_ntb_peer_db_addr,
        .peer_db_set            = intel_ntb_peer_db_set,
        .spad_is_unsafe         = intel_ntb_spad_is_unsafe,
        .spad_count             = intel_ntb_spad_count,
        .spad_read              = intel_ntb_spad_read,
        .spad_write             = intel_ntb_spad_write,
        .peer_spad_addr         = intel_ntb_peer_spad_addr,
        .peer_spad_read         = intel_ntb_peer_spad_read,
        .peer_spad_write        = intel_ntb_peer_spad_write,
};

static const struct ntb_dev_ops intel_ntb3_ops = {
        .mw_count               = intel_ntb_mw_count,
        .mw_get_range           = intel_ntb_mw_get_range,
        .mw_set_trans           = intel_ntb3_mw_set_trans,
        .link_is_up             = intel_ntb_link_is_up,
        .link_enable            = intel_ntb3_link_enable,
        .link_disable           = intel_ntb_link_disable,
        .db_valid_mask          = intel_ntb_db_valid_mask,
        .db_vector_count        = intel_ntb_db_vector_count,
        .db_vector_mask         = intel_ntb_db_vector_mask,
        .db_read                = intel_ntb3_db_read,
        .db_clear               = intel_ntb3_db_clear,
        .db_set_mask            = intel_ntb_db_set_mask,
        .db_clear_mask          = intel_ntb_db_clear_mask,
        .peer_db_addr           = intel_ntb_peer_db_addr,
        .peer_db_set            = intel_ntb3_peer_db_set,
        .spad_is_unsafe         = intel_ntb_spad_is_unsafe,
        .spad_count             = intel_ntb_spad_count,
        .spad_read              = intel_ntb_spad_read,
        .spad_write             = intel_ntb_spad_write,
        .peer_spad_addr         = intel_ntb_peer_spad_addr,
        .peer_spad_read         = intel_ntb_peer_spad_read,
        .peer_spad_write        = intel_ntb_peer_spad_write,
};

static const struct file_operations intel_ntb_debugfs_info = {
        .owner = THIS_MODULE,
        .open = simple_open,
        .read = ndev_debugfs_read,
};

static const struct pci_device_id intel_ntb_pci_tbl[] = {
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_BWD)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_JSF)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_SNB)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_IVT)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_HSX)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_BDX)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_JSF)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_SNB)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_IVT)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_HSX)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_PS_BDX)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_JSF)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_SNB)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_IVT)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_HSX)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_SS_BDX)},
        {PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_NTB_B2B_SKX)},
        {0}
};
MODULE_DEVICE_TABLE(pci, intel_ntb_pci_tbl);

static struct pci_driver intel_ntb_pci_driver = {
        .name = KBUILD_MODNAME,
        .id_table = intel_ntb_pci_tbl,
        .probe = intel_ntb_pci_probe,
        .remove = intel_ntb_pci_remove,
};

static int __init intel_ntb_pci_driver_init(void)
{
        pr_info("%s %s\n", NTB_DESC, NTB_VER);

        if (debugfs_initialized())
                debugfs_dir = debugfs_create_dir(KBUILD_MODNAME, NULL);

        return pci_register_driver(&intel_ntb_pci_driver);