From b46793510b200c4120f03963252f7f54d23f6f8b Mon Sep 17 00:00:00 2001
From: Changsheng Wu <wuchangsheng2@huawei.com>
Date: Sat, 18 Dec 2021 19:07:58 +0800
Subject: [PATCH] add igb_uio

---
 kernel/linux/igb_uio/Kbuild      |   2 +
 kernel/linux/igb_uio/compat.h    | 154 +++++++
 kernel/linux/igb_uio/igb_uio.c   | 674 +++++++++++++++++++++++++++++++
 kernel/linux/igb_uio/meson.build |  27 ++
 kernel/linux/meson.build         |   2 +-
 meson_options.txt                |   2 +-
 6 files changed, 859 insertions(+), 2 deletions(-)
 create mode 100644 kernel/linux/igb_uio/Kbuild
 create mode 100644 kernel/linux/igb_uio/compat.h
 create mode 100644 kernel/linux/igb_uio/igb_uio.c
 create mode 100644 kernel/linux/igb_uio/meson.build

diff --git a/kernel/linux/igb_uio/Kbuild b/kernel/linux/igb_uio/Kbuild
new file mode 100644
index 0000000000..3ab85c4116
--- /dev/null
+++ b/kernel/linux/igb_uio/Kbuild
@@ -0,0 +1,2 @@
+ccflags-y := $(MODULE_CFLAGS)
+obj-m := igb_uio.o
diff --git a/kernel/linux/igb_uio/compat.h b/kernel/linux/igb_uio/compat.h
new file mode 100644
index 0000000000..8dbb896ae1
--- /dev/null
+++ b/kernel/linux/igb_uio/compat.h
@@ -0,0 +1,154 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Minimal wrappers to allow compiling igb_uio on older kernels.
+ */
+
+#ifndef RHEL_RELEASE_VERSION
+#define RHEL_RELEASE_VERSION(a, b) (((a) << 8) + (b))
+#endif
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 3, 0)
+#define pci_cfg_access_lock   pci_block_user_cfg_access
+#define pci_cfg_access_unlock pci_unblock_user_cfg_access
+#endif
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 18, 0)
+#define HAVE_PTE_MASK_PAGE_IOMAP
+#endif
+
+#ifndef PCI_MSIX_ENTRY_SIZE
+#define PCI_MSIX_ENTRY_SIZE            16
+#define PCI_MSIX_ENTRY_VECTOR_CTRL     12
+#define PCI_MSIX_ENTRY_CTRL_MASKBIT    1
+#endif
+
+/*
+ * for kernels < 2.6.38 and backported patch that moves MSI-X entry definition
+ * to pci_regs.h Those kernels has PCI_MSIX_ENTRY_SIZE defined but not
+ * PCI_MSIX_ENTRY_CTRL_MASKBIT
+ */
+#ifndef PCI_MSIX_ENTRY_CTRL_MASKBIT
+#define PCI_MSIX_ENTRY_CTRL_MASKBIT    1
+#endif
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 34) && \
+	(!(defined(RHEL_RELEASE_CODE) && \
+	 RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(5, 9)))
+
+static int pci_num_vf(struct pci_dev *dev)
+{
+	struct iov {
+		int pos;
+		int nres;
+		u32 cap;
+		u16 ctrl;
+		u16 total;
+		u16 initial;
+		u16 nr_virtfn;
+	} *iov = (struct iov *)dev->sriov;
+
+	if (!dev->is_physfn)
+		return 0;
+
+	return iov->nr_virtfn;
+}
+
+#endif /* < 2.6.34 */
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 39) && \
+	(!(defined(RHEL_RELEASE_CODE) && \
+	   RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(6, 4)))
+
+#define kstrtoul strict_strtoul
+
+#endif /* < 2.6.39 */
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 3, 0) && \
+	(!(defined(RHEL_RELEASE_CODE) && \
+	   RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(6, 3)))
+
+/* Check if INTX works to control irq's.
+ * Set's INTX_DISABLE flag and reads it back
+ */
+static bool pci_intx_mask_supported(struct pci_dev *pdev)
+{
+	bool mask_supported = false;
+	uint16_t orig, new;
+
+	pci_block_user_cfg_access(pdev);
+	pci_read_config_word(pdev, PCI_COMMAND, &orig);
+	pci_write_config_word(pdev, PCI_COMMAND,
+			      orig ^ PCI_COMMAND_INTX_DISABLE);
+	pci_read_config_word(pdev, PCI_COMMAND, &new);
+
+	if ((new ^ orig) & ~PCI_COMMAND_INTX_DISABLE) {
+		dev_err(&pdev->dev, "Command register changed from "
+			"0x%x to 0x%x: driver or hardware bug?\n", orig, new);
+	} else if ((new ^ orig) & PCI_COMMAND_INTX_DISABLE) {
+		mask_supported = true;
+		pci_write_config_word(pdev, PCI_COMMAND, orig);
+	}
+	pci_unblock_user_cfg_access(pdev);
+
+	return mask_supported;
+}
+
+static bool pci_check_and_mask_intx(struct pci_dev *pdev)
+{
+	bool pending;
+	uint32_t status;
+
+	pci_block_user_cfg_access(pdev);
+	pci_read_config_dword(pdev, PCI_COMMAND, &status);
+
+	/* interrupt is not ours, goes to out */
+	pending = (((status >> 16) & PCI_STATUS_INTERRUPT) != 0);
+	if (pending) {
+		uint16_t old, new;
+
+		old = status;
+		if (status != 0)
+			new = old & (~PCI_COMMAND_INTX_DISABLE);
+		else
+			new = old | PCI_COMMAND_INTX_DISABLE;
+
+		if (old != new)
+			pci_write_config_word(pdev, PCI_COMMAND, new);
+	}
+	pci_unblock_user_cfg_access(pdev);
+
+	return pending;
+}
+
+#endif /* < 3.3.0 */
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 16, 0)
+#define HAVE_PCI_IS_BRIDGE_API 1
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 3, 0)
+#define HAVE_MSI_LIST_IN_GENERIC_DEVICE 1
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 5, 0)
+#define HAVE_PCI_MSI_MASK_IRQ 1
+#endif
+
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 8, 0)
+#define HAVE_ALLOC_IRQ_VECTORS 1
+#endif
+
+static inline bool igbuio_kernel_is_locked_down(void)
+{
+#ifdef CONFIG_LOCK_DOWN_KERNEL
+#ifdef CONFIG_LOCK_DOWN_IN_EFI_SECURE_BOOT
+	return kernel_is_locked_down(NULL);
+#elif defined(CONFIG_EFI_SECURE_BOOT_LOCK_DOWN)
+	return kernel_is_locked_down();
+#else
+	return false;
+#endif
+#else
+	return false;
+#endif
+}
diff --git a/kernel/linux/igb_uio/igb_uio.c b/kernel/linux/igb_uio/igb_uio.c
new file mode 100644
index 0000000000..ea439d131d
--- /dev/null
+++ b/kernel/linux/igb_uio/igb_uio.c
@@ -0,0 +1,674 @@
+// SPDX-License-Identifier: GPL-2.0
+/*-
+ * Copyright(c) 2010-2017 Intel Corporation. All rights reserved.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/uio_driver.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/msi.h>
+#include <linux/version.h>
+#include <linux/slab.h>
+
+/**
+ * These enum and macro definitions are copied from the
+ * file rte_pci_dev_features.h
+ */
+enum rte_intr_mode {
+	RTE_INTR_MODE_NONE = 0,
+	RTE_INTR_MODE_LEGACY,
+	RTE_INTR_MODE_MSI,
+	RTE_INTR_MODE_MSIX
+};
+#define RTE_INTR_MODE_NONE_NAME "none"
+#define RTE_INTR_MODE_LEGACY_NAME "legacy"
+#define RTE_INTR_MODE_MSI_NAME "msi"
+#define RTE_INTR_MODE_MSIX_NAME "msix"
+
+
+#include "compat.h"
+
+/**
+ * A structure describing the private information for a uio device.
+ */
+struct rte_uio_pci_dev {
+	struct uio_info info;
+	struct pci_dev *pdev;
+	enum rte_intr_mode mode;
+	atomic_t refcnt;
+};
+
+static int wc_activate;
+static char *intr_mode;
+static enum rte_intr_mode igbuio_intr_mode_preferred = RTE_INTR_MODE_MSIX;
+/* sriov sysfs */
+static ssize_t
+show_max_vfs(struct device *dev, struct device_attribute *attr,
+	     char *buf)
+{
+	return snprintf(buf, 10, "%u\n", dev_num_vf(dev));
+}
+
+static ssize_t
+store_max_vfs(struct device *dev, struct device_attribute *attr,
+	      const char *buf, size_t count)
+{
+	int err = 0;
+	unsigned long max_vfs;
+	struct pci_dev *pdev = to_pci_dev(dev);
+
+	if (0 != kstrtoul(buf, 0, &max_vfs))
+		return -EINVAL;
+
+	if (0 == max_vfs)
+		pci_disable_sriov(pdev);
+	else if (0 == pci_num_vf(pdev))
+		err = pci_enable_sriov(pdev, max_vfs);
+	else /* do nothing if change max_vfs number */
+		err = -EINVAL;
+
+	return err ? err : count;
+}
+
+static DEVICE_ATTR(max_vfs, S_IRUGO | S_IWUSR, show_max_vfs, store_max_vfs);
+
+static struct attribute *dev_attrs[] = {
+	&dev_attr_max_vfs.attr,
+	NULL,
+};
+
+static const struct attribute_group dev_attr_grp = {
+	.attrs = dev_attrs,
+};
+
+#ifndef HAVE_PCI_MSI_MASK_IRQ
+/*
+ * It masks the msix on/off of generating MSI-X messages.
+ */
+static void
+igbuio_msix_mask_irq(struct msi_desc *desc, s32 state)
+{
+	u32 mask_bits = desc->masked;
+	unsigned int offset = desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE +
+						PCI_MSIX_ENTRY_VECTOR_CTRL;
+
+	if (state != 0)
+		mask_bits &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
+	else
+		mask_bits |= PCI_MSIX_ENTRY_CTRL_MASKBIT;
+
+	if (mask_bits != desc->masked) {
+		writel(mask_bits, desc->mask_base + offset);
+		readl(desc->mask_base);
+		desc->masked = mask_bits;
+	}
+}
+
+/*
+ * It masks the msi on/off of generating MSI messages.
+ */
+static void
+igbuio_msi_mask_irq(struct pci_dev *pdev, struct msi_desc *desc, int32_t state)
+{
+	u32 mask_bits = desc->masked;
+	u32 offset = desc->irq - pdev->irq;
+	u32 mask = 1 << offset;
+
+	if (!desc->msi_attrib.maskbit)
+		return;
+
+	if (state != 0)
+		mask_bits &= ~mask;
+	else
+		mask_bits |= mask;
+
+	if (mask_bits != desc->masked) {
+		pci_write_config_dword(pdev, desc->mask_pos, mask_bits);
+		desc->masked = mask_bits;
+	}
+}
+
+static void
+igbuio_mask_irq(struct pci_dev *pdev, enum rte_intr_mode mode, s32 irq_state)
+{
+	struct msi_desc *desc;
+	struct list_head *msi_list;
+
+#ifdef HAVE_MSI_LIST_IN_GENERIC_DEVICE
+	msi_list = &pdev->dev.msi_list;
+#else
+	msi_list = &pdev->msi_list;
+#endif
+
+	if (mode == RTE_INTR_MODE_MSIX) {
+		list_for_each_entry(desc, msi_list, list)
+			igbuio_msix_mask_irq(desc, irq_state);
+	} else if (mode == RTE_INTR_MODE_MSI) {
+		list_for_each_entry(desc, msi_list, list)
+			igbuio_msi_mask_irq(pdev, desc, irq_state);
+	}
+}
+#endif
+
+/**
+ * This is the irqcontrol callback to be registered to uio_info.
+ * It can be used to disable/enable interrupt from user space processes.
+ *
+ * @param info
+ *  pointer to uio_info.
+ * @param irq_state
+ *  state value. 1 to enable interrupt, 0 to disable interrupt.
+ *
+ * @return
+ *  - On success, 0.
+ *  - On failure, a negative value.
+ */
+static int
+igbuio_pci_irqcontrol(struct uio_info *info, s32 irq_state)
+{
+	struct rte_uio_pci_dev *udev = info->priv;
+	struct pci_dev *pdev = udev->pdev;
+
+#ifdef HAVE_PCI_MSI_MASK_IRQ
+	struct irq_data *irq = irq_get_irq_data(udev->info.irq);
+#endif
+
+	pci_cfg_access_lock(pdev);
+
+	if (udev->mode == RTE_INTR_MODE_MSIX || udev->mode == RTE_INTR_MODE_MSI) {
+#ifdef HAVE_PCI_MSI_MASK_IRQ
+		if (irq_state == 1)
+			pci_msi_unmask_irq(irq);
+		else
+			pci_msi_mask_irq(irq);
+#else
+		igbuio_mask_irq(pdev, udev->mode, irq_state);
+#endif
+	}
+
+	if (udev->mode == RTE_INTR_MODE_LEGACY)
+		pci_intx(pdev, !!irq_state);
+
+	pci_cfg_access_unlock(pdev);
+
+	return 0;
+}
+
+/**
+ * This is interrupt handler which will check if the interrupt is for the right device.
+ * If yes, disable it here and will be enable later.
+ */
+static irqreturn_t
+igbuio_pci_irqhandler(int irq, void *dev_id)
+{
+	struct rte_uio_pci_dev *udev = (struct rte_uio_pci_dev *)dev_id;
+	struct uio_info *info = &udev->info;
+
+	/* Legacy mode need to mask in hardware */
+	if (udev->mode == RTE_INTR_MODE_LEGACY &&
+	    !pci_check_and_mask_intx(udev->pdev))
+		return IRQ_NONE;
+
+	uio_event_notify(info);
+
+	/* Message signal mode, no share IRQ and automasked */
+	return IRQ_HANDLED;
+}
+
+static int
+igbuio_pci_enable_interrupts(struct rte_uio_pci_dev *udev)
+{
+	int err = 0;
+#ifndef HAVE_ALLOC_IRQ_VECTORS
+	struct msix_entry msix_entry;
+#endif
+
+	switch (igbuio_intr_mode_preferred) {
+	case RTE_INTR_MODE_MSIX:
+		/* Only 1 msi-x vector needed */
+#ifndef HAVE_ALLOC_IRQ_VECTORS
+		msix_entry.entry = 0;
+		if (pci_enable_msix(udev->pdev, &msix_entry, 1) == 0) {
+			dev_dbg(&udev->pdev->dev, "using MSI-X");
+			udev->info.irq_flags = IRQF_NO_THREAD;
+			udev->info.irq = msix_entry.vector;
+			udev->mode = RTE_INTR_MODE_MSIX;
+			break;
+		}
+#else
+		if (pci_alloc_irq_vectors(udev->pdev, 1, 1, PCI_IRQ_MSIX) == 1) {
+			dev_dbg(&udev->pdev->dev, "using MSI-X");
+			udev->info.irq_flags = IRQF_NO_THREAD;
+			udev->info.irq = pci_irq_vector(udev->pdev, 0);
+			udev->mode = RTE_INTR_MODE_MSIX;
+			break;
+		}
+#endif
+
+	/* falls through - to MSI */
+	case RTE_INTR_MODE_MSI:
+#ifndef HAVE_ALLOC_IRQ_VECTORS
+		if (pci_enable_msi(udev->pdev) == 0) {
+			dev_dbg(&udev->pdev->dev, "using MSI");
+			udev->info.irq_flags = IRQF_NO_THREAD;
+			udev->info.irq = udev->pdev->irq;
+			udev->mode = RTE_INTR_MODE_MSI;
+			break;
+		}
+#else
+		if (pci_alloc_irq_vectors(udev->pdev, 1, 1, PCI_IRQ_MSI) == 1) {
+			dev_dbg(&udev->pdev->dev, "using MSI");
+			udev->info.irq_flags = IRQF_NO_THREAD;
+			udev->info.irq = pci_irq_vector(udev->pdev, 0);
+			udev->mode = RTE_INTR_MODE_MSI;
+			break;
+		}
+#endif
+	/* falls through - to INTX */
+	case RTE_INTR_MODE_LEGACY:
+		if (pci_intx_mask_supported(udev->pdev)) {
+			dev_dbg(&udev->pdev->dev, "using INTX");
+			udev->info.irq_flags = IRQF_SHARED | IRQF_NO_THREAD;
+			udev->info.irq = udev->pdev->irq;
+			udev->mode = RTE_INTR_MODE_LEGACY;
+			break;
+		}
+		dev_notice(&udev->pdev->dev, "PCI INTX mask not supported\n");
+	/* falls through - to no IRQ */
+	case RTE_INTR_MODE_NONE:
+		udev->mode = RTE_INTR_MODE_NONE;
+		udev->info.irq = UIO_IRQ_NONE;
+		break;
+
+	default:
+		dev_err(&udev->pdev->dev, "invalid IRQ mode %u",
+			igbuio_intr_mode_preferred);
+		udev->info.irq = UIO_IRQ_NONE;
+		err = -EINVAL;
+	}
+
+	if (udev->info.irq != UIO_IRQ_NONE)
+		err = request_irq(udev->info.irq, igbuio_pci_irqhandler,
+				  udev->info.irq_flags, udev->info.name,
+				  udev);
+	dev_info(&udev->pdev->dev, "uio device registered with irq %ld\n",
+		 udev->info.irq);
+
+	return err;
+}
+
+static void
+igbuio_pci_disable_interrupts(struct rte_uio_pci_dev *udev)
+{
+	if (udev->info.irq) {
+		free_irq(udev->info.irq, udev);
+		udev->info.irq = 0;
+	}
+
+#ifndef HAVE_ALLOC_IRQ_VECTORS
+	if (udev->mode == RTE_INTR_MODE_MSIX)
+		pci_disable_msix(udev->pdev);
+	if (udev->mode == RTE_INTR_MODE_MSI)
+		pci_disable_msi(udev->pdev);
+#else
+	if (udev->mode == RTE_INTR_MODE_MSIX ||
+	    udev->mode == RTE_INTR_MODE_MSI)
+		pci_free_irq_vectors(udev->pdev);
+#endif
+}
+
+
+/**
+ * This gets called while opening uio device file.
+ */
+static int
+igbuio_pci_open(struct uio_info *info, struct inode *inode)
+{
+	struct rte_uio_pci_dev *udev = info->priv;
+	struct pci_dev *dev = udev->pdev;
+	int err;
+
+	if (atomic_inc_return(&udev->refcnt) != 1)
+		return 0;
+
+	/* set bus master, which was cleared by the reset function */
+	pci_set_master(dev);
+
+	/* enable interrupts */
+	err = igbuio_pci_enable_interrupts(udev);
+	if (err) {
+		atomic_dec(&udev->refcnt);
+		dev_err(&dev->dev, "Enable interrupt fails\n");
+	}
+	return err;
+}
+
+static int
+igbuio_pci_release(struct uio_info *info, struct inode *inode)
+{
+	struct rte_uio_pci_dev *udev = info->priv;
+	struct pci_dev *dev = udev->pdev;
+
+	if (atomic_dec_and_test(&udev->refcnt)) {
+		/* disable interrupts */
+		igbuio_pci_disable_interrupts(udev);
+
+		/* stop the device from further DMA */
+		pci_clear_master(dev);
+	}
+
+	return 0;
+}
+
+/* Remap pci resources described by bar #pci_bar in uio resource n. */
+static int
+igbuio_pci_setup_iomem(struct pci_dev *dev, struct uio_info *info,
+		       int n, int pci_bar, const char *name)
+{
+	unsigned long addr, len;
+	void *internal_addr;
+
+	if (n >= ARRAY_SIZE(info->mem))
+		return -EINVAL;
+
+	addr = pci_resource_start(dev, pci_bar);
+	len = pci_resource_len(dev, pci_bar);
+	if (addr == 0 || len == 0)
+		return -1;
+	if (wc_activate == 0) {
+		internal_addr = ioremap(addr, len);
+		if (internal_addr == NULL)
+			return -1;
+	} else {
+		internal_addr = NULL;
+	}
+	info->mem[n].name = name;
+	info->mem[n].addr = addr;
+	info->mem[n].internal_addr = internal_addr;
+	info->mem[n].size = len;
+	info->mem[n].memtype = UIO_MEM_PHYS;
+	return 0;
+}
+
+/* Get pci port io resources described by bar #pci_bar in uio resource n. */
+static int
+igbuio_pci_setup_ioport(struct pci_dev *dev, struct uio_info *info,
+		int n, int pci_bar, const char *name)
+{
+	unsigned long addr, len;
+
+	if (n >= ARRAY_SIZE(info->port))
+		return -EINVAL;
+
+	addr = pci_resource_start(dev, pci_bar);
+	len = pci_resource_len(dev, pci_bar);
+	if (addr == 0 || len == 0)
+		return -EINVAL;
+
+	info->port[n].name = name;
+	info->port[n].start = addr;
+	info->port[n].size = len;
+	info->port[n].porttype = UIO_PORT_X86;
+
+	return 0;
+}
+
+/* Unmap previously ioremap'd resources */
+static void
+igbuio_pci_release_iomem(struct uio_info *info)
+{
+	int i;
+
+	for (i = 0; i < MAX_UIO_MAPS; i++) {
+		if (info->mem[i].internal_addr)
+			iounmap(info->mem[i].internal_addr);
+	}
+}
+
+static int
+igbuio_setup_bars(struct pci_dev *dev, struct uio_info *info)
+{
+	int i, iom, iop, ret;
+	unsigned long flags;
+	static const char *bar_names[PCI_STD_RESOURCE_END + 1]  = {
+		"BAR0",
+		"BAR1",
+		"BAR2",
+		"BAR3",
+		"BAR4",
+		"BAR5",
+	};
+
+	iom = 0;
+	iop = 0;
+
+	for (i = 0; i < ARRAY_SIZE(bar_names); i++) {
+		if (pci_resource_len(dev, i) != 0 &&
+				pci_resource_start(dev, i) != 0) {
+			flags = pci_resource_flags(dev, i);
+			if (flags & IORESOURCE_MEM) {
+				ret = igbuio_pci_setup_iomem(dev, info, iom,
+							     i, bar_names[i]);
+				if (ret != 0)
+					return ret;
+				iom++;
+			} else if (flags & IORESOURCE_IO) {
+				ret = igbuio_pci_setup_ioport(dev, info, iop,
+							      i, bar_names[i]);
+				if (ret != 0)
+					return ret;
+				iop++;
+			}
+		}
+	}
+
+	return (iom != 0 || iop != 0) ? ret : -ENOENT;
+}
+
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 8, 0)
+static int __devinit
+#else
+static int
+#endif
+igbuio_pci_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+	struct rte_uio_pci_dev *udev;
+	dma_addr_t map_dma_addr;
+	void *map_addr;
+	int err;
+
+#ifdef HAVE_PCI_IS_BRIDGE_API
+	if (pci_is_bridge(dev)) {
+		dev_warn(&dev->dev, "Ignoring PCI bridge device\n");
+		return -ENODEV;
+	}
+#endif
+
+	udev = kzalloc(sizeof(struct rte_uio_pci_dev), GFP_KERNEL);
+	if (!udev)
+		return -ENOMEM;
+
+	/*
+	 * enable device: ask low-level code to enable I/O and
+	 * memory
+	 */
+	err = pci_enable_device(dev);
+	if (err != 0) {
+		dev_err(&dev->dev, "Cannot enable PCI device\n");
+		goto fail_free;
+	}
+
+	/* enable bus mastering on the device */
+	pci_set_master(dev);
+
+	/* remap IO memory */
+	err = igbuio_setup_bars(dev, &udev->info);
+	if (err != 0)
+		goto fail_release_iomem;
+
+	/* set 64-bit DMA mask */
+	err = pci_set_dma_mask(dev,  DMA_BIT_MASK(64));
+	if (err != 0) {
+		dev_err(&dev->dev, "Cannot set DMA mask\n");
+		goto fail_release_iomem;
+	}
+
+	err = pci_set_consistent_dma_mask(dev, DMA_BIT_MASK(64));
+	if (err != 0) {
+		dev_err(&dev->dev, "Cannot set consistent DMA mask\n");
+		goto fail_release_iomem;
+	}
+
+	/* fill uio infos */
+	udev->info.name = "igb_uio";
+	udev->info.version = "0.1";
+	udev->info.irqcontrol = igbuio_pci_irqcontrol;
+	udev->info.open = igbuio_pci_open;
+	udev->info.release = igbuio_pci_release;
+	udev->info.priv = udev;
+	udev->pdev = dev;
+	atomic_set(&udev->refcnt, 0);
+
+	err = sysfs_create_group(&dev->dev.kobj, &dev_attr_grp);
+	if (err != 0)
+		goto fail_release_iomem;
+
+	/* register uio driver */
+	err = uio_register_device(&dev->dev, &udev->info);
+	if (err != 0)
+		goto fail_remove_group;
+
+	pci_set_drvdata(dev, udev);
+
+	/*
+	 * Doing a harmless dma mapping for attaching the device to
+	 * the iommu identity mapping if kernel boots with iommu=pt.
+	 * Note this is not a problem if no IOMMU at all.
+	 */
+	map_addr = dma_alloc_coherent(&dev->dev, 1024, &map_dma_addr,
+			GFP_KERNEL);
+	if (map_addr)
+		memset(map_addr, 0, 1024);
+
+	if (!map_addr)
+		dev_info(&dev->dev, "dma mapping failed\n");
+	else {
+		dev_info(&dev->dev, "mapping 1K dma=%#llx host=%p\n",
+			 (unsigned long long)map_dma_addr, map_addr);
+
+		dma_free_coherent(&dev->dev, 1024, map_addr, map_dma_addr);
+		dev_info(&dev->dev, "unmapping 1K dma=%#llx host=%p\n",
+			 (unsigned long long)map_dma_addr, map_addr);
+	}
+
+	return 0;
+
+fail_remove_group:
+	sysfs_remove_group(&dev->dev.kobj, &dev_attr_grp);
+fail_release_iomem:
+	igbuio_pci_release_iomem(&udev->info);
+	pci_disable_device(dev);
+fail_free:
+	kfree(udev);
+
+	return err;
+}
+
+static void
+igbuio_pci_remove(struct pci_dev *dev)
+{
+	struct rte_uio_pci_dev *udev = pci_get_drvdata(dev);
+
+	igbuio_pci_release(&udev->info, NULL);
+
+	sysfs_remove_group(&dev->dev.kobj, &dev_attr_grp);
+	uio_unregister_device(&udev->info);
+	igbuio_pci_release_iomem(&udev->info);
+	pci_disable_device(dev);
+	pci_set_drvdata(dev, NULL);
+	kfree(udev);
+}
+
+static int
+igbuio_config_intr_mode(char *intr_str)
+{
+	if (!intr_str) {
+		pr_info("Use MSIX interrupt by default\n");
+		return 0;
+	}
+
+	if (!strcmp(intr_str, RTE_INTR_MODE_MSIX_NAME)) {
+		igbuio_intr_mode_preferred = RTE_INTR_MODE_MSIX;
+		pr_info("Use MSIX interrupt\n");
+	} else if (!strcmp(intr_str, RTE_INTR_MODE_MSI_NAME)) {
+		igbuio_intr_mode_preferred = RTE_INTR_MODE_MSI;
+		pr_info("Use MSI interrupt\n");
+	} else if (!strcmp(intr_str, RTE_INTR_MODE_LEGACY_NAME)) {
+		igbuio_intr_mode_preferred = RTE_INTR_MODE_LEGACY;
+		pr_info("Use legacy interrupt\n");
+	} else {
+		pr_info("Error: bad parameter - %s\n", intr_str);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static struct pci_driver igbuio_pci_driver = {
+	.name = "igb_uio",
+	.id_table = NULL,
+	.probe = igbuio_pci_probe,
+	.remove = igbuio_pci_remove,
+};
+
+static int __init
+igbuio_pci_init_module(void)
+{
+	int ret;
+
+	if (igbuio_kernel_is_locked_down()) {
+		pr_err("Not able to use module, kernel lock down is enabled\n");
+		return -EINVAL;
+	}
+
+	if (wc_activate != 0)
+		pr_info("wc_activate is set\n");
+
+	ret = igbuio_config_intr_mode(intr_mode);
+	if (ret < 0)
+		return ret;
+
+	return pci_register_driver(&igbuio_pci_driver);
+}
+
+static void __exit
+igbuio_pci_exit_module(void)
+{
+	pci_unregister_driver(&igbuio_pci_driver);
+}
+
+module_init(igbuio_pci_init_module);
+module_exit(igbuio_pci_exit_module);
+
+module_param(intr_mode, charp, S_IRUGO);
+MODULE_PARM_DESC(intr_mode,
+"igb_uio interrupt mode (default=msix):\n"
+"    " RTE_INTR_MODE_MSIX_NAME "       Use MSIX interrupt\n"
+"    " RTE_INTR_MODE_MSI_NAME "        Use MSI interrupt\n"
+"    " RTE_INTR_MODE_LEGACY_NAME "     Use Legacy interrupt\n"
+"\n");
+
+module_param(wc_activate, int, 0);
+MODULE_PARM_DESC(wc_activate,
+"Activate support for write combining (WC) (default=0)\n"
+"    0 - disable\n"
+"    other - enable\n");
+
+MODULE_DESCRIPTION("UIO driver for Intel IGB PCI cards");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Intel Corporation");
diff --git a/kernel/linux/igb_uio/meson.build b/kernel/linux/igb_uio/meson.build
new file mode 100644
index 0000000000..ff8f97ca23
--- /dev/null
+++ b/kernel/linux/igb_uio/meson.build
@@ -0,0 +1,27 @@
+# SPDX-License-Identifier: BSD-3-Clause
+# Copyright(c) 2018 Luca Boccassi <bluca@debian.org>
+
+# For SUSE build check function arguments of ndo_tx_timeout API
+# Ref: https://jira.devtools.intel.com/browse/DPDK-29263
+kmod_cflags = ''
+
+igb_uio_mkfile = custom_target('igb_uio_makefile',
+        output: 'Makefile',
+        command: ['touch', '@OUTPUT@'])
+
+igb_uio_sources = files(
+        'igb_uio.c',
+        'Kbuild',
+)
+
+custom_target('igb_uio',
+        input: igb_uio_sources,
+        output: 'igb_uio.ko',
+        command: ['make', '-j4', '-C', kernel_build_dir,
+            'M=' + meson.current_build_dir(),
+            'src=' + meson.current_source_dir(),
+            'modules'] + cross_args,
+        depends: igb_uio_mkfile,
+        install: install,
+        install_dir: kernel_install_dir,
+        build_by_default: get_option('enable_kmods'))
diff --git a/kernel/linux/meson.build b/kernel/linux/meson.build
index 0637452e95..3230368f14 100644
--- a/kernel/linux/meson.build
+++ b/kernel/linux/meson.build
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: BSD-3-Clause
 # Copyright(c) 2018 Intel Corporation
 
-subdirs = ['kni']
+subdirs = ['kni', 'igb_uio']
 
 kernel_build_dir = get_option('kernel_dir')
 kernel_source_dir = get_option('kernel_dir')
diff --git a/meson_options.txt b/meson_options.txt
index 7c220ad68d..d2e172facd 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -18,7 +18,7 @@ option('enable_drivers', type: 'string', value: '', description:
        'Comma-separated list of drivers to build. If unspecified, build all drivers.')
 option('enable_driver_sdk', type: 'boolean', value: false, description:
        'Install headers to build drivers.')
-option('enable_kmods', type: 'boolean', value: false, description:
+option('enable_kmods', type: 'boolean', value: true, description:
        'build kernel modules')
 option('examples', type: 'string', value: '', description:
        'Comma-separated list of examples to build by default')
-- 
2.27.0