NTB: Add support for AMD PCI-Express Non-Transparent Bridge

This adds support for AMD's PCI-Express Non-Transparent Bridge
(NTB) device on the Zeppelin platform. The driver connnects to the
standard NTB sub-system interface, with modification to add hooks
for power management in a separate patch. The AMD NTB device has 3
memory windows, 16 doorbell, 16 scratch-pad registers, and supports
up to 16 PCIe lanes running a Gen3 speeds.

Signed-off-by: Xiangliang Yu <Xiangliang.Yu@amd.com>
Reviewed-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

7 files changed, 1376 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 233f83464814..3485ebf92c8e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7586,6 +7586,12 @@ W:	https://github.com/jonmason/ntb/wiki
 T:	git git://github.com/jonmason/ntb.git
 F:	drivers/ntb/hw/intel/
 
+NTB AMD DRIVER
+M:	Xiangliang Yu <Xiangliang.Yu@amd.com>
+L:	linux-ntb@googlegroups.com
+S:	Supported
+F:	drivers/ntb/hw/amd/
+
 NTFS FILESYSTEM
 M:	Anton Altaparmakov <anton@tuxera.com>
 L:	linux-ntfs-dev@lists.sourceforge.net
diff --git a/drivers/ntb/hw/Kconfig b/drivers/ntb/hw/Kconfig
index 4d5535c4cddf..7116472b4625 100644
--- a/drivers/ntb/hw/Kconfig
+++ b/drivers/ntb/hw/Kconfig
@@ -1 +1,2 @@
+source "drivers/ntb/hw/amd/Kconfig"
 source "drivers/ntb/hw/intel/Kconfig"
diff --git a/drivers/ntb/hw/Makefile b/drivers/ntb/hw/Makefile
index 175d7c92a569..532e0859b4a1 100644
--- a/drivers/ntb/hw/Makefile
+++ b/drivers/ntb/hw/Makefile
@@ -1 +1,2 @@
+obj-$(CONFIG_NTB_AMD)	+= amd/
 obj-$(CONFIG_NTB_INTEL)	+= intel/
diff --git a/drivers/ntb/hw/amd/Kconfig b/drivers/ntb/hw/amd/Kconfig
new file mode 100644
index 000000000000..cfe903cd9514
--- /dev/null
+++ b/drivers/ntb/hw/amd/Kconfig
@@ -0,0 +1,7 @@
+config NTB_AMD
+	tristate "AMD Non-Transparent Bridge support"
+	depends on X86_64
+	help
+	 This driver supports AMD NTB on capable Zeppelin hardware.
+
+	 If unsure, say N.
diff --git a/drivers/ntb/hw/amd/Makefile b/drivers/ntb/hw/amd/Makefile
new file mode 100644
index 000000000000..ad54da917563
--- /dev/null
+++ b/drivers/ntb/hw/amd/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_NTB_AMD) += ntb_hw_amd.o
diff --git a/drivers/ntb/hw/amd/ntb_hw_amd.c b/drivers/ntb/hw/amd/ntb_hw_amd.c
new file mode 100644
index 000000000000..588803ad6847
--- /dev/null
+++ b/drivers/ntb/hw/amd/ntb_hw_amd.c
@@ -0,0 +1,1143 @@
+/*
+ * 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) 2016 Advanced Micro Devices, Inc. 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) 2016 Advanced Micro Devices, Inc. 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 AMD 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.
+ *
+ * AMD PCIe NTB Linux driver
+ *
+ * Contact Information:
+ * Xiangliang Yu <Xiangliang.Yu@amd.com>
+ */
+
+#include <linux/debugfs.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/module.h>
+#include <linux/acpi.h>
+#include <linux/pci.h>
+#include <linux/random.h>
+#include <linux/slab.h>
+#include <linux/ntb.h>
+
+#include "ntb_hw_amd.h"
+
+#define NTB_NAME	"ntb_hw_amd"
+#define NTB_DESC	"AMD(R) PCI-E Non-Transparent Bridge Driver"
+#define NTB_VER		"1.0"
+
+MODULE_DESCRIPTION(NTB_DESC);
+MODULE_VERSION(NTB_VER);
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_AUTHOR("AMD Inc.");
+
+static const struct file_operations amd_ntb_debugfs_info;
+static struct dentry *debugfs_dir;
+
+static int ndev_mw_to_bar(struct amd_ntb_dev *ndev, int idx)
+{
+	if (idx < 0 || idx > ndev->mw_count)
+		return -EINVAL;
+
+	return 1 << idx;
+}
+
+static int amd_ntb_mw_count(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->mw_count;
+}
+
+static int amd_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 amd_ntb_dev *ndev = ntb_ndev(ntb);
+	int bar;
+
+	bar = ndev_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	if (base)
+		*base = pci_resource_start(ndev->ntb.pdev, bar);
+
+	if (size)
+		*size = pci_resource_len(ndev->ntb.pdev, bar);
+
+	if (align)
+		*align = SZ_4K;
+
+	if (align_size)
+		*align_size = 1;
+
+	return 0;
+}
+
+static int amd_ntb_mw_set_trans(struct ntb_dev *ntb, int idx,
+				dma_addr_t addr, resource_size_t size)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	unsigned long xlat_reg, limit_reg = 0;
+	resource_size_t mw_size;
+	void __iomem *mmio, *peer_mmio;
+	u64 base_addr, limit, reg_val;
+	int bar;
+
+	bar = ndev_mw_to_bar(ndev, idx);
+	if (bar < 0)
+		return bar;
+
+	mw_size = pci_resource_len(ndev->ntb.pdev, bar);
+
+	/* make sure the range fits in the usable mw size */
+	if (size > mw_size)
+		return -EINVAL;
+
+	mmio = ndev->self_mmio;
+	peer_mmio = ndev->peer_mmio;
+
+	base_addr = pci_resource_start(ndev->ntb.pdev, bar);
+
+	if (bar != 1) {
+		xlat_reg = AMD_BAR23XLAT_OFFSET + ((bar - 2) << 3);
+		limit_reg = AMD_BAR23LMT_OFFSET + ((bar - 2) << 3);
+
+		/* Set the limit if supported */
+		limit = base_addr + size;
+
+		/* set and verify setting the translation address */
+		write64(addr, peer_mmio + xlat_reg);
+		reg_val = read64(peer_mmio + xlat_reg);
+		if (reg_val != addr) {
+			write64(0, peer_mmio + xlat_reg);
+			return -EIO;
+		}
+
+		/* set and verify setting the limit */
+		write64(limit, mmio + limit_reg);
+		reg_val = read64(mmio + limit_reg);
+		if (reg_val != limit) {
+			write64(base_addr, mmio + limit_reg);
+			write64(0, peer_mmio + xlat_reg);
+			return -EIO;
+		}
+	} else {
+		xlat_reg = AMD_BAR1XLAT_OFFSET;
+		limit_reg = AMD_BAR1LMT_OFFSET;
+
+		/* split bar addr range must all be 32 bit */
+		if (addr & (~0ull << 32))
+			return -EINVAL;
+		if ((addr + size) & (~0ull << 32))
+			return -EINVAL;
+
+		/* Set the limit if supported */
+		limit = base_addr + size;
+
+		/* set and verify setting the translation address */
+		write64(addr, peer_mmio + xlat_reg);
+		reg_val = read64(peer_mmio + xlat_reg);
+		if (reg_val != addr) {
+			write64(0, peer_mmio + xlat_reg);
+			return -EIO;
+		}
+
+		/* set and verify setting the limit */
+		writel(limit, mmio + limit_reg);
+		reg_val = readl(mmio + limit_reg);
+		if (reg_val != limit) {
+			writel(base_addr, mmio + limit_reg);
+			writel(0, peer_mmio + xlat_reg);
+			return -EIO;
+		}
+	}
+
+	return 0;
+}
+
+static int amd_link_is_up(struct amd_ntb_dev *ndev)
+{
+	if (!ndev->peer_sta)
+		return NTB_LNK_STA_ACTIVE(ndev->cntl_sta);
+
+	/* If peer_sta is reset or D0 event, the ISR has
+	 * started a timer to check link status of hardware.
+	 * So here just clear status bit. And if peer_sta is
+	 * D3 or PME_TO, D0/reset event will be happened when
+	 * system wakeup/poweron, so do nothing here.
+	 */
+	if (ndev->peer_sta & AMD_PEER_RESET_EVENT)
+		ndev->peer_sta &= ~AMD_PEER_RESET_EVENT;
+	else if (ndev->peer_sta & AMD_PEER_D0_EVENT)
+		ndev->peer_sta = 0;
+
+	return 0;
+}
+
+static int amd_ntb_link_is_up(struct ntb_dev *ntb,
+			      enum ntb_speed *speed,
+			      enum ntb_width *width)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	int ret = 0;
+
+	if (amd_link_is_up(ndev)) {
+		if (speed)
+			*speed = NTB_LNK_STA_SPEED(ndev->lnk_sta);
+		if (width)
+			*width = NTB_LNK_STA_WIDTH(ndev->lnk_sta);
+
+		dev_dbg(ndev_dev(ndev), "link is up.\n");
+
+		ret = 1;
+	} else {
+		if (speed)
+			*speed = NTB_SPEED_NONE;
+		if (width)
+			*width = NTB_WIDTH_NONE;
+
+		dev_dbg(ndev_dev(ndev), "link is down.\n");
+	}
+
+	return ret;
+}
+
+static int amd_ntb_link_enable(struct ntb_dev *ntb,
+			       enum ntb_speed max_speed,
+			       enum ntb_width max_width)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	u32 ntb_ctl;
+
+	/* Enable event interrupt */
+	ndev->int_mask &= ~AMD_EVENT_INTMASK;
+	writel(ndev->int_mask, mmio + AMD_INTMASK_OFFSET);
+
+	if (ndev->ntb.topo == NTB_TOPO_SEC)
+		return -EINVAL;
+	dev_dbg(ndev_dev(ndev), "Enabling Link.\n");
+
+	ntb_ctl = readl(mmio + AMD_CNTL_OFFSET);
+	ntb_ctl |= (PMM_REG_CTL | SMM_REG_CTL);
+	writel(ntb_ctl, mmio + AMD_CNTL_OFFSET);
+
+	return 0;
+}
+
+static int amd_ntb_link_disable(struct ntb_dev *ntb)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	u32 ntb_ctl;
+
+	/* Disable event interrupt */
+	ndev->int_mask |= AMD_EVENT_INTMASK;
+	writel(ndev->int_mask, mmio + AMD_INTMASK_OFFSET);
+
+	if (ndev->ntb.topo == NTB_TOPO_SEC)
+		return -EINVAL;
+	dev_dbg(ndev_dev(ndev), "Enabling Link.\n");
+
+	ntb_ctl = readl(mmio + AMD_CNTL_OFFSET);
+	ntb_ctl &= ~(PMM_REG_CTL | SMM_REG_CTL);
+	writel(ntb_ctl, mmio + AMD_CNTL_OFFSET);
+
+	return 0;
+}
+
+static u64 amd_ntb_db_valid_mask(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->db_valid_mask;
+}
+
+static int amd_ntb_db_vector_count(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->db_count;
+}
+
+static u64 amd_ntb_db_vector_mask(struct ntb_dev *ntb, int db_vector)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+
+	if (db_vector < 0 || db_vector > ndev->db_count)
+		return 0;
+
+	return ntb_ndev(ntb)->db_valid_mask & (1 << db_vector);
+}
+
+static u64 amd_ntb_db_read(struct ntb_dev *ntb)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+
+	return (u64)readw(mmio + AMD_DBSTAT_OFFSET);
+}
+
+static int amd_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+
+	writew((u16)db_bits, mmio + AMD_DBSTAT_OFFSET);
+
+	return 0;
+}
+
+static int amd_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	unsigned long flags;
+
+	if (db_bits & ~ndev->db_valid_mask)
+		return -EINVAL;
+
+	spin_lock_irqsave(&ndev->db_mask_lock, flags);
+	ndev->db_mask |= db_bits;
+	writew((u16)ndev->db_mask, mmio + AMD_DBMASK_OFFSET);
+	spin_unlock_irqrestore(&ndev->db_mask_lock, flags);
+
+	return 0;
+}
+
+static int amd_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	unsigned long flags;
+
+	if (db_bits & ~ndev->db_valid_mask)
+		return -EINVAL;
+
+	spin_lock_irqsave(&ndev->db_mask_lock, flags);
+	ndev->db_mask &= ~db_bits;
+	writew((u16)ndev->db_mask, mmio + AMD_DBMASK_OFFSET);
+	spin_unlock_irqrestore(&ndev->db_mask_lock, flags);
+
+	return 0;
+}
+
+static int amd_ntb_peer_db_addr(struct ntb_dev *ntb,
+				phys_addr_t *db_addr,
+				resource_size_t *db_size)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+
+	if (db_addr)
+		*db_addr = (phys_addr_t)(ndev->peer_mmio + AMD_DBREQ_OFFSET);
+	if (db_size)
+		*db_size = sizeof(u32);
+
+	return 0;
+}
+
+static int amd_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+
+	writew((u16)db_bits, mmio + AMD_DBREQ_OFFSET);
+
+	return 0;
+}
+
+static int amd_ntb_spad_count(struct ntb_dev *ntb)
+{
+	return ntb_ndev(ntb)->spad_count;
+}
+
+static u32 amd_ntb_spad_read(struct ntb_dev *ntb, int idx)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	u32 offset;
+
+	if (idx < 0 || idx >= ndev->spad_count)
+		return 0;
+
+	offset = ndev->self_spad + (idx << 2);
+	return readl(mmio + AMD_SPAD_OFFSET + offset);
+}
+
+static int amd_ntb_spad_write(struct ntb_dev *ntb,
+			      int idx, u32 val)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	u32 offset;
+
+	if (idx < 0 || idx >= ndev->spad_count)
+		return -EINVAL;
+
+	offset = ndev->self_spad + (idx << 2);
+	writel(val, mmio + AMD_SPAD_OFFSET + offset);
+
+	return 0;
+}
+
+static int amd_ntb_peer_spad_addr(struct ntb_dev *ntb, int idx,
+				  phys_addr_t *spad_addr)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+
+	if (idx < 0 || idx >= ndev->spad_count)
+		return -EINVAL;
+
+	if (spad_addr)
+		*spad_addr = (phys_addr_t)(ndev->self_mmio + AMD_SPAD_OFFSET +
+					   ndev->peer_spad + (idx << 2));
+	return 0;
+}
+
+static u32 amd_ntb_peer_spad_read(struct ntb_dev *ntb, int idx)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	u32 offset;
+
+	if (idx < 0 || idx >= ndev->spad_count)
+		return -EINVAL;
+
+	offset = ndev->peer_spad + (idx << 2);
+	return readl(mmio + AMD_SPAD_OFFSET + offset);
+}
+
+static int amd_ntb_peer_spad_write(struct ntb_dev *ntb,
+				   int idx, u32 val)
+{
+	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
+	void __iomem *mmio = ndev->self_mmio;
+	u32 offset;
+
+	if (idx < 0 || idx >= ndev->spad_count)
+		return -EINVAL;
+
+	offset = ndev->peer_spad + (idx << 2);
+	writel(val, mmio + AMD_SPAD_OFFSET + offset);
+
+	return 0;
+}
+
+static const struct ntb_dev_ops amd_ntb_ops = {
+	.mw_count		= amd_ntb_mw_count,
+	.mw_get_range		= amd_ntb_mw_get_range,
+	.mw_set_trans		= amd_ntb_mw_set_trans,
+	.link_is_up		= amd_ntb_link_is_up,
+	.link_enable		= amd_ntb_link_enable,
+	.link_disable		= amd_ntb_link_disable,
+	.db_valid_mask		= amd_ntb_db_valid_mask,
+	.db_vector_count	= amd_ntb_db_vector_count,
+	.db_vector_mask		= amd_ntb_db_vector_mask,
+	.db_read		= amd_ntb_db_read,
+	.db_clear		= amd_ntb_db_clear,
+	.db_set_mask		= amd_ntb_db_set_mask,
+	.db_clear_mask		= amd_ntb_db_clear_mask,
+	.peer_db_addr		= amd_ntb_peer_db_addr,
+	.peer_db_set		= amd_ntb_peer_db_set,
+	.spad_count		= amd_ntb_spad_count,
+	.spad_read		= amd_ntb_spad_read,
+	.spad_write		= amd_ntb_spad_write,
+	.peer_spad_addr		= amd_ntb_peer_spad_addr,
+	.peer_spad_read		= amd_ntb_peer_spad_read,
+	.peer_spad_write	= amd_ntb_peer_spad_write,
+};
+
+static void amd_ack_smu(struct amd_ntb_dev *ndev, u32 bit)
+{
+	void __iomem *mmio = ndev->self_mmio;
+	int reg;
+
+	reg = readl(mmio + AMD_SMUACK_OFFSET);
+	reg |= bit;
+	writel(reg, mmio + AMD_SMUACK_OFFSET);
+
+	ndev->peer_sta |= bit;
+}
+
+static void amd_handle_event(struct amd_ntb_dev *ndev, int vec)
+{
+	void __iomem *mmio = ndev->self_mmio;
+	u32 status;
+
+	status = readl(mmio + AMD_INTSTAT_OFFSET);
+	if (!(status & AMD_EVENT_INTMASK))
+		return;
+
+	dev_dbg(ndev_dev(ndev), "status = 0x%x and vec = %d\n", status, vec);
+
+	status &= AMD_EVENT_INTMASK;
+	switch (status) {
+	case AMD_PEER_FLUSH_EVENT:
+		dev_info(ndev_dev(ndev), "Flush is done.\n");
+		break;
+	case AMD_PEER_RESET_EVENT:
+		amd_ack_smu(ndev, AMD_PEER_RESET_EVENT);
+
+		/* link down first */
+		ntb_link_event(&ndev->ntb);
+		/* polling peer status */
+		schedule_delayed_work(&ndev->hb_timer, AMD_LINK_HB_TIMEOUT);
+
+		break;
+	case AMD_PEER_D3_EVENT:
+	case AMD_PEER_PMETO_EVENT:
+		amd_ack_smu(ndev, status);
+
+		/* link down */
+		ntb_link_event(&ndev->ntb);
+
+		break;
+	case AMD_PEER_D0_EVENT:
+		mmio = ndev->peer_mmio;
+		status = readl(mmio + AMD_PMESTAT_OFFSET);
+		/* check if this is WAKEUP event */
+		if (status & 0x1)
+			dev_info(ndev_dev(ndev), "Wakeup is done.\n");
+
+		amd_ack_smu(ndev, AMD_PEER_D0_EVENT);
+
+		/* start a timer to poll link status */
+		schedule_delayed_work(&ndev->hb_timer,
+				      AMD_LINK_HB_TIMEOUT);
+		break;
+	default:
+		dev_info(ndev_dev(ndev), "event status = 0x%x.\n", status);
+		break;
+	}
+}
+
+static irqreturn_t ndev_interrupt(struct amd_ntb_dev *ndev, int vec)
+{
+	dev_dbg(ndev_dev(ndev), "vec %d\n", vec);
+
+	if (vec > (AMD_DB_CNT - 1) || (ndev->msix_vec_count == 1))
+		amd_handle_event(ndev, vec);
+
+	if (vec < AMD_DB_CNT)
+		ntb_db_event(&ndev->ntb, vec);
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t ndev_vec_isr(int irq, void *dev)
+{
+	struct amd_ntb_vec *nvec = dev;
+
+	return ndev_interrupt(nvec->ndev, nvec->num);
+}
+
+static irqreturn_t ndev_irq_isr(int irq, void *dev)
+{
+	struct amd_ntb_dev *ndev = dev;
+
+	return ndev_interrupt(ndev, irq - ndev_pdev(ndev)->irq);
+}
+
+static int ndev_init_isr(struct amd_ntb_dev *ndev,
+			 int msix_min, int msix_max)
+{
+	struct pci_dev *pdev;
+	int rc, i, msix_count, node;
+
+	pdev = ndev_pdev(ndev);
+
+	node = dev_to_node(&pdev->dev);
+
+	ndev->db_mask = ndev->db_valid_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;
+
+	/* NOTE: Disable MSIX if msix count is less than 16 because of
+	 * hardware limitation.
+	 */
+	if (msix_count < msix_min) {
+		pci_disable_msix(pdev);
+		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 msix interrupts\n");
+	ndev->db_count = msix_min;
+	ndev->msix_vec_count = msix_max;
+	return 0;
+
+err_msix_request:
+	while (i-- > 0)
+		free_irq(ndev->msix[i].vector, ndev);
+	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_count = 1;
+	ndev->msix_vec_count = 1;
+	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_count = 1;
+	ndev->msix_vec_count = 1;
+	return 0;
+
+err_intx_request:
+	return rc;
+}
+
+static void ndev_deinit_isr(struct amd_ntb_dev *ndev)
+{
+	struct pci_dev *pdev;
+	void __iomem *mmio = ndev->self_mmio;
+	int i;
+
+	pdev = ndev_pdev(ndev);
+
+	/* Mask all doorbell interrupts */
+	ndev->db_mask = ndev->db_valid_mask;
+	writel(ndev->db_mask, mmio + AMD_DBMASK_OFFSET);
+
+	if (ndev->msix) {
+		i = ndev->msix_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);
+		else
+			pci_intx(pdev, 0);
+	}
+}
+
+static ssize_t ndev_debugfs_read(struct file *filp, char __user *ubuf,
+				 size_t count, loff_t *offp)
+{
+	struct amd_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,
+			 "LNK STA -\t\t%#06x\n", ndev->lnk_sta);
+
+	if (!amd_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,
+			 "MSIX Vector Count -\t%u\n", ndev->msix_vec_count);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Valid Mask -\t%#llx\n", ndev->db_valid_mask);
+
+	u.v32 = readl(ndev->self_mmio + AMD_DBMASK_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Mask -\t\t\t%#06x\n", u.v32);
+
+	u.v32 = readl(mmio + AMD_DBSTAT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "Doorbell Bell -\t\t\t%#06x\n", u.v32);
+
+	off += scnprintf(buf + off, buf_size - off,
+			 "\nNTB Incoming XLAT:\n");
+
+	u.v64 = read64(mmio + AMD_BAR1XLAT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "XLAT1 -\t\t%#018llx\n", u.v64);
+
+	u.v64 = read64(ndev->self_mmio + AMD_BAR23XLAT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "XLAT23 -\t\t%#018llx\n", u.v64);
+
+	u.v64 = read64(ndev->self_mmio + AMD_BAR45XLAT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "XLAT45 -\t\t%#018llx\n", u.v64);
+
+	u.v32 = readl(mmio + AMD_BAR1LMT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "LMT1 -\t\t\t%#06x\n", u.v32);
+
+	u.v64 = read64(ndev->self_mmio + AMD_BAR23LMT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "LMT23 -\t\t\t%#018llx\n", u.v64);
+
+	u.v64 = read64(ndev->self_mmio + AMD_BAR45LMT_OFFSET);
+	off += scnprintf(buf + off, buf_size - off,
+			 "LMT45 -\t\t\t%#018llx\n", u.v64);
+
+	ret = simple_read_from_buffer(ubuf, count, offp, buf, off);
+	kfree(buf);
+	return ret;
+}
+
+static void ndev_init_debugfs(struct amd_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,
+						    &amd_ntb_debugfs_info);
+	}
+}
+
+static void ndev_deinit_debugfs(struct amd_ntb_dev *ndev)
+{
+	debugfs_remove_recursive(ndev->debugfs_dir);
+}
+
+static inline void ndev_init_struct(struct amd_ntb_dev *ndev,
+				    struct pci_dev *pdev)
+{
+	ndev->ntb.pdev = pdev;
+	ndev->ntb.topo = NTB_TOPO_NONE;
+	ndev->ntb.ops = &amd_ntb_ops;
+	ndev->int_mask = AMD_EVENT_INTMASK;
+	spin_lock_init(&ndev->db_mask_lock);
+}
+
+static int amd_poll_link(struct amd_ntb_dev *ndev)
+{
+	void __iomem *mmio = ndev->peer_mmio;
+	u32 reg, stat;
+	int rc;
+
+	reg = readl(mmio + AMD_SIDEINFO_OFFSET);
+	reg &= NTB_LIN_STA_ACTIVE_BIT;
+
+	dev_dbg(ndev_dev(ndev), "%s: reg_val = 0x%x.\n", __func__, reg);
+
+	if (reg == ndev->cntl_sta)
+		return 0;
+
+	ndev->cntl_sta = reg;
+
+	rc = pci_read_config_dword(ndev->ntb.pdev,
+				   AMD_LINK_STATUS_OFFSET, &stat);
+	if (rc)
+		return 0;
+	ndev->lnk_sta = stat;
+
+	return 1;
+}
+
+static void amd_link_hb(struct work_struct *work)
+{
+	struct amd_ntb_dev *ndev = hb_ndev(work);
+
+	if (amd_poll_link(ndev))
+		ntb_link_event(&ndev->ntb);
+
+	if (!amd_link_is_up(ndev))
+		schedule_delayed_work(&ndev->hb_timer, AMD_LINK_HB_TIMEOUT);
+}
+
+static int amd_init_isr(struct amd_ntb_dev *ndev)
+{
+	return ndev_init_isr(ndev, AMD_DB_CNT, AMD_MSIX_VECTOR_CNT);
+}
+
+static void amd_init_side_info(struct amd_ntb_dev *ndev)
+{
+	void __iomem *mmio = ndev->self_mmio;
+	unsigned int reg;
+
+	reg = readl(mmio + AMD_SIDEINFO_OFFSET);
+	if (!(reg & AMD_SIDE_READY)) {
+		reg |= AMD_SIDE_READY;
+		writel(reg, mmio + AMD_SIDEINFO_OFFSET);
+	}
+}
+
+static void amd_deinit_side_info(struct amd_ntb_dev *ndev)
+{
+	void __iomem *mmio = ndev->self_mmio;
+	unsigned int reg;
+
+	reg = readl(mmio + AMD_SIDEINFO_OFFSET);
+	if (reg & AMD_SIDE_READY) {
+		reg &= ~AMD_SIDE_READY;
+		writel(reg, mmio + AMD_SIDEINFO_OFFSET);
+		readl(mmio + AMD_SIDEINFO_OFFSET);
+	}
+}
+
+static int amd_init_ntb(struct amd_ntb_dev *ndev)
+{
+	void __iomem *mmio = ndev->self_mmio;
+
+	ndev->mw_count = AMD_MW_CNT;
+	ndev->spad_count = AMD_SPADS_CNT;
+	ndev->db_count = AMD_DB_CNT;
+
+	switch (ndev->ntb.topo) {
+	case NTB_TOPO_PRI:
+	case NTB_TOPO_SEC:
+		ndev->spad_count >>= 1;
+		if (ndev->ntb.topo == NTB_TOPO_PRI) {
+			ndev->self_spad = 0;
+			ndev->peer_spad = 0x20;
+		} else {
+			ndev->self_spad = 0x20;
+			ndev->peer_spad = 0;
+		}
+
+		INIT_DELAYED_WORK(&ndev->hb_timer, amd_link_hb);
+		schedule_delayed_work(&ndev->hb_timer, AMD_LINK_HB_TIMEOUT);
+
+		break;
+	default:
+		dev_err(ndev_dev(ndev), "AMD NTB does not support B2B mode.\n");
+		return -EINVAL;
+	}
+
+	ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
+
+	/* Mask event interrupts */
+	writel(ndev->int_mask, mmio + AMD_INTMASK_OFFSET);
+
+	return 0;
+}
+
+static enum ntb_topo amd_get_topo(struct amd_ntb_dev *ndev)
+{
+	void __iomem *mmio = ndev->self_mmio;
+	u32 info;
+
+	info = readl(mmio + AMD_SIDEINFO_OFFSET);
+	if (info & AMD_SIDE_MASK)
+		return NTB_TOPO_SEC;
+	else
+		return NTB_TOPO_PRI;
+}
+
+static int amd_init_dev(struct amd_ntb_dev *ndev)
+{
+	struct pci_dev *pdev;
+	int rc = 0;
+
+	pdev = ndev_pdev(ndev);
+
+	ndev->ntb.topo = amd_get_topo(ndev);
+	dev_dbg(ndev_dev(ndev), "AMD NTB topo is %s\n",
+		ntb_topo_string(ndev->ntb.topo));
+
+	rc = amd_init_ntb(ndev);
+	if (rc)
+		return rc;
+
+	rc = amd_init_isr(ndev);
+	if (rc) {
+		dev_err(ndev_dev(ndev), "fail to init isr.\n");
+		return rc;
+	}
+
+	ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
+
+	return 0;
+}
+
+static void amd_deinit_dev(struct amd_ntb_dev *ndev)
+{
+	cancel_delayed_work_sync(&ndev->hb_timer);
+
+	ndev_deinit_isr(ndev);
+}
+
+static int amd_ntb_init_pci(struct amd_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_dma_mask;
+	}
+	ndev->peer_mmio = ndev->self_mmio + AMD_PEER_OFFSET;
+
+	return 0;
+
+err_dma_mask:
+	pci_clear_master(pdev);
+err_pci_regions:
+	pci_disable_device(pdev);
+err_pci_enable:
+	pci_set_drvdata(pdev, NULL);
+	return rc;
+}
+
+static void amd_ntb_deinit_pci(struct amd_ntb_dev *ndev)
+{
+	struct pci_dev *pdev = ndev_pdev(ndev);
+
+	pci_iounmap(pdev, ndev->self_mmio);
+
+	pci_clear_master(pdev);
+	pci_release_regions(pdev);
+	pci_disable_device(pdev);
+	pci_set_drvdata(pdev, NULL);
+}
+
+static int amd_ntb_pci_probe(struct pci_dev *pdev,
+			     const struct pci_device_id *id)
+{
+	struct amd_ntb_dev *ndev;
+	int rc, node;
+
+	node = dev_to_node(&pdev->dev);
+
+	ndev = kzalloc_node(sizeof(*ndev), GFP_KERNEL, node);
+	if (!ndev) {
+		rc = -ENOMEM;
+		goto err_ndev;
+	}
+
+	ndev_init_struct(ndev, pdev);
+
+	rc = amd_ntb_init_pci(ndev, pdev);
+	if (rc)
+		goto err_init_pci;
+
+	rc = amd_init_dev(ndev);
+	if (rc)
+		goto err_init_dev;
+
+	/* write side info */
+	amd_init_side_info(ndev);
+
+	amd_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);
+	amd_deinit_dev(ndev);
+err_init_dev:
+	amd_ntb_deinit_pci(ndev);
+err_init_pci:
+	kfree(ndev);
+err_ndev:
+	return rc;
+}
+
+static void amd_ntb_pci_remove(struct pci_dev *pdev)
+{
+	struct amd_ntb_dev *ndev = pci_get_drvdata(pdev);
+
+	ntb_unregister_device(&ndev->ntb);
+	ndev_deinit_debugfs(ndev);
+	amd_deinit_side_info(ndev);
+	amd_deinit_dev(ndev);
+	amd_ntb_deinit_pci(ndev);
+	kfree(ndev);
+}
+
+static const struct file_operations amd_ntb_debugfs_info = {
+	.owner = THIS_MODULE,
+	.open = simple_open,
+	.read = ndev_debugfs_read,
+};
+
+static const struct pci_device_id amd_ntb_pci_tbl[] = {
+	{PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_NTB)},
+	{0}
+};
+MODULE_DEVICE_TABLE(pci, amd_ntb_pci_tbl);
+
+static struct pci_driver amd_ntb_pci_driver = {
+	.name		= KBUILD_MODNAME,
+	.id_table	= amd_ntb_pci_tbl,
+	.probe		= amd_ntb_pci_probe,
+	.remove		= amd_ntb_pci_remove,
+};
+
+static int __init amd_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(&amd_ntb_pci_driver);
+}
+module_init(amd_ntb_pci_driver_init);
+
+static void __exit amd_ntb_pci_driver_exit(void)
+{
+	pci_unregister_driver(&amd_ntb_pci_driver);
+	debugfs_remove_recursive(debugfs_dir);
+}
+module_exit(amd_ntb_pci_driver_exit);
diff --git a/drivers/ntb/hw/amd/ntb_hw_amd.h b/drivers/ntb/hw/amd/ntb_hw_amd.h
new file mode 100644
index 000000000000..2eac3cd3e646
--- /dev/null
+++ b/drivers/ntb/hw/amd/ntb_hw_amd.h
@@ -0,0 +1,217 @@
+/*
+ * 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) 2016 Advanced Micro Devices, Inc. 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) 2016 Advanced Micro Devices, Inc. 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 AMD 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.
+ *
+ * AMD PCIe NTB Linux driver
+ *
+ * Contact Information:
+ * Xiangliang Yu <Xiangliang.Yu@amd.com>
+ */
+
+#ifndef NTB_HW_AMD_H
+#define NTB_HW_AMD_H
+
+#include <linux/ntb.h>
+#include <linux/pci.h>
+
+#define PCI_DEVICE_ID_AMD_NTB	0x145B
+#define AMD_LINK_HB_TIMEOUT	msecs_to_jiffies(1000)
+#define AMD_LINK_STATUS_OFFSET	0x68
+#define NTB_LIN_STA_ACTIVE_BIT	0x00000002
+#define NTB_LNK_STA_SPEED_MASK	0x000F0000
+#define NTB_LNK_STA_WIDTH_MASK	0x03F00000
+#define NTB_LNK_STA_ACTIVE(x)	(!!((x) & NTB_LIN_STA_ACTIVE_BIT))
+#define NTB_LNK_STA_SPEED(x)	(((x) & NTB_LNK_STA_SPEED_MASK) >> 16)
+#define NTB_LNK_STA_WIDTH(x)	(((x) & NTB_LNK_STA_WIDTH_MASK) >> 20)
+
+#ifndef read64
+#ifdef readq
+#define read64 readq
+#else
+#define read64 _read64
+static inline u64 _read64(void __iomem *mmio)
+{
+	u64 low, high;
+
+	low = readl(mmio);
+	high = readl(mmio + sizeof(u32));
+	return low | (high << 32);
+}
+#endif
+#endif
+
+#ifndef write64
+#ifdef writeq
+#define write64 writeq
+#else
+#define write64 _write64
+static inline void _write64(u64 val, void __iomem *mmio)
+{
+	writel(val, mmio);
+	writel(val >> 32, mmio + sizeof(u32));
+}
+#endif
+#endif
+
+enum {
+	/* AMD NTB Capability */
+	AMD_MW_CNT		= 3,
+	AMD_DB_CNT		= 16,
+	AMD_MSIX_VECTOR_CNT	= 24,
+	AMD_SPADS_CNT		= 16,
+
+	/*  AMD NTB register offset */
+	AMD_CNTL_OFFSET		= 0x200,
+
+	/* NTB control register bits */
+	PMM_REG_CTL		= BIT(21),
+	SMM_REG_CTL		= BIT(20),
+	SMM_REG_ACC_PATH	= BIT(18),
+	PMM_REG_ACC_PATH	= BIT(17),
+	NTB_CLK_EN		= BIT(16),
+
+	AMD_STA_OFFSET		= 0x204,
+	AMD_PGSLV_OFFSET	= 0x208,
+	AMD_SPAD_MUX_OFFSET	= 0x20C,
+	AMD_SPAD_OFFSET		= 0x210,
+	AMD_RSMU_HCID		= 0x250,
+	AMD_RSMU_SIID		= 0x254,
+	AMD_PSION_OFFSET	= 0x300,
+	AMD_SSION_OFFSET	= 0x330,
+	AMD_MMINDEX_OFFSET	= 0x400,
+	AMD_MMDATA_OFFSET	= 0x404,
+	AMD_SIDEINFO_OFFSET	= 0x408,
+
+	AMD_SIDE_MASK		= BIT(0),
+	AMD_SIDE_READY		= BIT(1),
+
+	/* limit register */
+	AMD_ROMBARLMT_OFFSET	= 0x410,
+	AMD_BAR1LMT_OFFSET	= 0x414,
+	AMD_BAR23LMT_OFFSET	= 0x418,
+	AMD_BAR45LMT_OFFSET	= 0x420,
+	/* xlat address */
+	AMD_POMBARXLAT_OFFSET	= 0x428,
+	AMD_BAR1XLAT_OFFSET	= 0x430,
+	AMD_BAR23XLAT_OFFSET	= 0x438,
+	AMD_BAR45XLAT_OFFSET	= 0x440,
+	/* doorbell and interrupt */
+	AMD_DBFM_OFFSET		= 0x450,
+	AMD_DBREQ_OFFSET	= 0x454,
+	AMD_MIRRDBSTAT_OFFSET	= 0x458,
+	AMD_DBMASK_OFFSET	= 0x45C,
+	AMD_DBSTAT_OFFSET	= 0x460,
+	AMD_INTMASK_OFFSET	= 0x470,
+	AMD_INTSTAT_OFFSET	= 0x474,
+
+	/* event type */
+	AMD_PEER_FLUSH_EVENT	= BIT(0),
+	AMD_PEER_RESET_EVENT	= BIT(1),
+	AMD_PEER_D3_EVENT	= BIT(2),
+	AMD_PEER_PMETO_EVENT	= BIT(3),
+	AMD_PEER_D0_EVENT	= BIT(4),
+	AMD_EVENT_INTMASK	= (AMD_PEER_FLUSH_EVENT |
+				AMD_PEER_RESET_EVENT | AMD_PEER_D3_EVENT |
+				AMD_PEER_PMETO_EVENT | AMD_PEER_D0_EVENT),
+
+	AMD_PMESTAT_OFFSET	= 0x480,
+	AMD_PMSGTRIG_OFFSET	= 0x490,
+	AMD_LTRLATENCY_OFFSET	= 0x494,
+	AMD_FLUSHTRIG_OFFSET	= 0x498,
+
+	/* SMU register*/
+	AMD_SMUACK_OFFSET	= 0x4A0,
+	AMD_SINRST_OFFSET	= 0x4A4,
+	AMD_RSPNUM_OFFSET	= 0x4A8,
+	AMD_SMU_SPADMUTEX	= 0x4B0,
+	AMD_SMU_SPADOFFSET	= 0x4B4,
+
+	AMD_PEER_OFFSET		= 0x400,
+};
+
+struct amd_ntb_dev;
+
+struct amd_ntb_vec {
+	struct amd_ntb_dev	*ndev;
+	int			num;
+};
+
+struct amd_ntb_dev {
+	struct ntb_dev ntb;
+
+	u32 ntb_side;
+	u32 lnk_sta;
+	u32 cntl_sta;
+	u32 peer_sta;
+
+	unsigned char mw_count;
+	unsigned char spad_count;
+	unsigned char db_count;
+	unsigned char msix_vec_count;
+
+	u64 db_valid_mask;
+	u64 db_mask;
+	u32 int_mask;
+
+	struct msix_entry *msix;
+	struct amd_ntb_vec *vec;
+
+	/* synchronize rmw access of db_mask and hw reg */
+	spinlock_t db_mask_lock;
+
+	void __iomem *self_mmio;
+	void __iomem *peer_mmio;
+	unsigned int self_spad;
+	unsigned int peer_spad;
+
+	struct delayed_work hb_timer;
+
+	struct dentry *debugfs_dir;
+	struct dentry *debugfs_info;
+};
+
+#define ndev_pdev(ndev) ((ndev)->ntb.pdev)
+#define ndev_name(ndev) pci_name(ndev_pdev(ndev))
+#define ndev_dev(ndev) (&ndev_pdev(ndev)->dev)
+#define ntb_ndev(__ntb) container_of(__ntb, struct amd_ntb_dev, ntb)
+#define hb_ndev(__work) container_of(__work, struct amd_ntb_dev, hb_timer.work)
+
+#endif