Imported upstream release 16.04

* gbp import-orig ../dpdk-16.04.tar.xz

Change-Id: Iac2196db782ba322f6974d8a752acc34ce5024c3
Signed-off-by: C.J. Collier <cjcollier@linuxfoundation.org>

1 files changed, 1224 insertions, 0 deletions

diff --git a/lib/librte_eal/linuxapp/eal/eal_interrupts.c b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
new file mode 100644
index 00000000..06b26a9e
--- /dev/null
+++ b/lib/librte_eal/linuxapp/eal/eal_interrupts.c
@@ -0,0 +1,1224 @@
+/*-
+ *   BSD LICENSE
+ *
+ *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ *   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 copyright
+ *       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.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <sys/queue.h>
+#include <stdarg.h>
+#include <unistd.h>
+#include <string.h>
+#include <errno.h>
+#include <inttypes.h>
+#include <sys/epoll.h>
+#include <sys/signalfd.h>
+#include <sys/ioctl.h>
+#include <sys/eventfd.h>
+#include <assert.h>
+
+#include <rte_common.h>
+#include <rte_interrupts.h>
+#include <rte_memory.h>
+#include <rte_memzone.h>
+#include <rte_launch.h>
+#include <rte_eal.h>
+#include <rte_per_lcore.h>
+#include <rte_lcore.h>
+#include <rte_atomic.h>
+#include <rte_branch_prediction.h>
+#include <rte_ring.h>
+#include <rte_debug.h>
+#include <rte_log.h>
+#include <rte_mempool.h>
+#include <rte_pci.h>
+#include <rte_malloc.h>
+#include <rte_errno.h>
+#include <rte_spinlock.h>
+
+#include "eal_private.h"
+#include "eal_vfio.h"
+#include "eal_thread.h"
+
+#define EAL_INTR_EPOLL_WAIT_FOREVER (-1)
+#define NB_OTHER_INTR               1
+
+static RTE_DEFINE_PER_LCORE(int, _epfd) = -1; /**< epoll fd per thread */
+
+/**
+ * union for pipe fds.
+ */
+union intr_pipefds{
+	struct {
+		int pipefd[2];
+	};
+	struct {
+		int readfd;
+		int writefd;
+	};
+};
+
+/**
+ * union buffer for reading on different devices
+ */
+union rte_intr_read_buffer {
+	int uio_intr_count;              /* for uio device */
+#ifdef VFIO_PRESENT
+	uint64_t vfio_intr_count;        /* for vfio device */
+#endif
+	uint64_t timerfd_num;            /* for timerfd */
+	char charbuf[16];                /* for others */
+};
+
+TAILQ_HEAD(rte_intr_cb_list, rte_intr_callback);
+TAILQ_HEAD(rte_intr_source_list, rte_intr_source);
+
+struct rte_intr_callback {
+	TAILQ_ENTRY(rte_intr_callback) next;
+	rte_intr_callback_fn cb_fn;  /**< callback address */
+	void *cb_arg;                /**< parameter for callback */
+};
+
+struct rte_intr_source {
+	TAILQ_ENTRY(rte_intr_source) next;
+	struct rte_intr_handle intr_handle; /**< interrupt handle */
+	struct rte_intr_cb_list callbacks;  /**< user callbacks */
+	uint32_t active;
+};
+
+/* global spinlock for interrupt data operation */
+static rte_spinlock_t intr_lock = RTE_SPINLOCK_INITIALIZER;
+
+/* union buffer for pipe read/write */
+static union intr_pipefds intr_pipe;
+
+/* interrupt sources list */
+static struct rte_intr_source_list intr_sources;
+
+/* interrupt handling thread */
+static pthread_t intr_thread;
+
+/* VFIO interrupts */
+#ifdef VFIO_PRESENT
+
+#define IRQ_SET_BUF_LEN  (sizeof(struct vfio_irq_set) + sizeof(int))
+/* irq set buffer length for queue interrupts and LSC interrupt */
+#define MSIX_IRQ_SET_BUF_LEN (sizeof(struct vfio_irq_set) + \
+			      sizeof(int) * (RTE_MAX_RXTX_INTR_VEC_ID + 1))
+
+/* enable legacy (INTx) interrupts */
+static int
+vfio_enable_intx(struct rte_intr_handle *intr_handle) {
+	struct vfio_irq_set *irq_set;
+	char irq_set_buf[IRQ_SET_BUF_LEN];
+	int len, ret;
+	int *fd_ptr;
+
+	len = sizeof(irq_set_buf);
+
+	/* enable INTx */
+	irq_set = (struct vfio_irq_set *) irq_set_buf;
+	irq_set->argsz = len;
+	irq_set->count = 1;
+	irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER;
+	irq_set->index = VFIO_PCI_INTX_IRQ_INDEX;
+	irq_set->start = 0;
+	fd_ptr = (int *) &irq_set->data;
+	*fd_ptr = intr_handle->fd;
+
+	ret = ioctl(intr_handle->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, irq_set);
+
+	if (ret) {
+		RTE_LOG(ERR, EAL, "Error enabling INTx interrupts for fd %d\n",
+						intr_handle->fd);
+		return -1;
+	}
+
+	/* unmask INTx after enabling */
+	memset(irq_set, 0, len);
+	len = sizeof(struct vfio_irq_set);
+	irq_set->argsz = len;
+	irq_set->count = 1;
+	irq_set->flags = VFIO_IRQ_SET_DATA_NONE | VFIO_IRQ_SET_ACTION_UNMASK;
+	irq_set->index = VFIO_PCI_INTX_IRQ_INDEX;
+	irq_set->start = 0;
+
+	ret = ioctl(intr_handle->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, irq_set);
+
+	if (ret) {
+		RTE_LOG(ERR, EAL, "Error unmasking INTx interrupts for fd %d\n",
+						intr_handle->fd);
+		return -1;
+	}
+	return 0;
+}
+
+/* disable legacy (INTx) interrupts */
+static int
+vfio_disable_intx(struct rte_intr_handle *intr_handle) {
+	struct vfio_irq_set *irq_set;
+	char irq_set_buf[IRQ_SET_BUF_LEN];
+	int len, ret;
+
+	len = sizeof(struct vfio_irq_set);
+
+	/* mask interrupts before disabling */
+	irq_set = (struct vfio_irq_set *) irq_set_buf;
+	irq_set->argsz = len;
+	irq_set->count = 1;
+	irq_set->flags = VFIO_IRQ_SET_DATA_NONE | VFIO_IRQ_SET_ACTION_UNMASK;
+	irq_set->index = VFIO_PCI_INTX_IRQ_INDEX;
+	irq_set->start = 0;
+
+	ret = ioctl(intr_handle->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, irq_set);
+
+	if (ret) {
+		RTE_LOG(ERR, EAL, "Error unmasking INTx interrupts for fd %d\n",
+						intr_handle->fd);
+		return -1;
+	}
+
+	/* disable INTx*/
+	memset(irq_set, 0, len);
+	irq_set->argsz = len;
+	irq_set->count = 0;
+	irq_set->flags = VFIO_IRQ_SET_DATA_NONE | VFIO_IRQ_SET_ACTION_TRIGGER;
+	irq_set->index = VFIO_PCI_INTX_IRQ_INDEX;
+	irq_set->start = 0;
+
+	ret = ioctl(intr_handle->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, irq_set);
+
+	if (ret) {
+		RTE_LOG(ERR, EAL,
+			"Error disabling INTx interrupts for fd %d\n", intr_handle->fd);
+		return -1;
+	}
+	return 0;
+}
+
+/* enable MSI interrupts */
+static int
+vfio_enable_msi(struct rte_intr_handle *intr_handle) {
+	int len, ret;
+	char irq_set_buf[IRQ_SET_BUF_LEN];
+	struct vfio_irq_set *irq_set;
+	int *fd_ptr;
+
+	len = sizeof(irq_set_buf);
+
+	irq_set = (struct vfio_irq_set *) irq_set_buf;
+	irq_set->argsz = len;
+	irq_set->count = 1;
+	irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER;
+	irq_set->index = VFIO_PCI_MSI_IRQ_INDEX;
+	irq_set->start = 0;
+	fd_ptr = (int *) &irq_set->data;
+	*fd_ptr = intr_handle->fd;
+
+	ret = ioctl(intr_handle->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, irq_set);
+
+	if (ret) {
+		RTE_LOG(ERR, EAL, "Error enabling MSI interrupts for fd %d\n",
+						intr_handle->fd);
+		return -1;
+	}
+	return 0;
+}
+
+/* disable MSI interrupts */
+static int
+vfio_disable_msi(struct rte_intr_handle *intr_handle) {
+	struct vfio_irq_set *irq_set;
+	char irq_set_buf[IRQ_SET_BUF_LEN];
+	int len, ret;
+
+	len = sizeof(struct vfio_irq_set);
+
+	irq_set = (struct vfio_irq_set *) irq_set_buf;
+	irq_set->argsz = len;
+	irq_set->count = 0;
+	irq_set->flags = VFIO_IRQ_SET_DATA_NONE | VFIO_IRQ_SET_ACTION_TRIGGER;
+	irq_set->index = VFIO_PCI_MSI_IRQ_INDEX;
+	irq_set->start = 0;
+
+	ret = ioctl(intr_handle->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, irq_set);
+
+	if (ret)
+		RTE_LOG(ERR, EAL,
+			"Error disabling MSI interrupts for fd %d\n", intr_handle->fd);
+
+	return ret;
+}
+
+/* enable MSI-X interrupts */
+static int
+vfio_enable_msix(struct rte_intr_handle *intr_handle) {
+	int len, ret;
+	char irq_set_buf[MSIX_IRQ_SET_BUF_LEN];
+	struct vfio_irq_set *irq_set;
+	int *fd_ptr;
+
+	len = sizeof(irq_set_buf);
+
+	irq_set = (struct vfio_irq_set *) irq_set_buf;
+	irq_set->argsz = len;
+	if (!intr_handle->max_intr)
+		intr_handle->max_intr = 1;
+	else if (intr_handle->max_intr > RTE_MAX_RXTX_INTR_VEC_ID)
+		intr_handle->max_intr = RTE_MAX_RXTX_INTR_VEC_ID + 1;
+
+	irq_set->count = intr_handle->max_intr;
+	irq_set->flags = VFIO_IRQ_SET_DATA_EVENTFD | VFIO_IRQ_SET_ACTION_TRIGGER;
+	irq_set->index = VFIO_PCI_MSIX_IRQ_INDEX;
+	irq_set->start = 0;
+	fd_ptr = (int *) &irq_set->data;
+	/* INTR vector offset 0 reserve for non-efds mapping */
+	fd_ptr[RTE_INTR_VEC_ZERO_OFFSET] = intr_handle->fd;
+	memcpy(&fd_ptr[RTE_INTR_VEC_RXTX_OFFSET], intr_handle->efds,
+		sizeof(*intr_handle->efds) * intr_handle->nb_efd);
+
+	ret = ioctl(intr_handle->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, irq_set);
+
+	if (ret) {
+		RTE_LOG(ERR, EAL, "Error enabling MSI-X interrupts for fd %d\n",
+						intr_handle->fd);
+		return -1;
+	}
+
+	return 0;
+}
+
+/* disable MSI-X interrupts */
+static int
+vfio_disable_msix(struct rte_intr_handle *intr_handle) {
+	struct vfio_irq_set *irq_set;
+	char irq_set_buf[MSIX_IRQ_SET_BUF_LEN];
+	int len, ret;
+
+	len = sizeof(struct vfio_irq_set);
+
+	irq_set = (struct vfio_irq_set *) irq_set_buf;
+	irq_set->argsz = len;
+	irq_set->count = 0;
+	irq_set->flags = VFIO_IRQ_SET_DATA_NONE | VFIO_IRQ_SET_ACTION_TRIGGER;
+	irq_set->index = VFIO_PCI_MSIX_IRQ_INDEX;
+	irq_set->start = 0;
+
+	ret = ioctl(intr_handle->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, irq_set);
+
+	if (ret)
+		RTE_LOG(ERR, EAL,
+			"Error disabling MSI-X interrupts for fd %d\n", intr_handle->fd);
+
+	return ret;
+}
+#endif
+
+static int
+uio_intx_intr_disable(struct rte_intr_handle *intr_handle)
+{
+	unsigned char command_high;
+
+	/* use UIO config file descriptor for uio_pci_generic */
+	if (pread(intr_handle->uio_cfg_fd, &command_high, 1, 5) != 1) {
+		RTE_LOG(ERR, EAL,
+			"Error reading interrupts status for fd %d\n",
+			intr_handle->uio_cfg_fd);
+		return -1;
+	}
+	/* disable interrupts */
+	command_high |= 0x4;
+	if (pwrite(intr_handle->uio_cfg_fd, &command_high, 1, 5) != 1) {
+		RTE_LOG(ERR, EAL,
+			"Error disabling interrupts for fd %d\n",
+			intr_handle->uio_cfg_fd);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int
+uio_intx_intr_enable(struct rte_intr_handle *intr_handle)
+{
+	unsigned char command_high;
+
+	/* use UIO config file descriptor for uio_pci_generic */
+	if (pread(intr_handle->uio_cfg_fd, &command_high, 1, 5) != 1) {
+		RTE_LOG(ERR, EAL,
+			"Error reading interrupts status for fd %d\n",
+			intr_handle->uio_cfg_fd);
+		return -1;
+	}
+	/* enable interrupts */
+	command_high &= ~0x4;
+	if (pwrite(intr_handle->uio_cfg_fd, &command_high, 1, 5) != 1) {
+		RTE_LOG(ERR, EAL,
+			"Error enabling interrupts for fd %d\n",
+			intr_handle->uio_cfg_fd);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int
+uio_intr_disable(struct rte_intr_handle *intr_handle)
+{
+	const int value = 0;
+
+	if (write(intr_handle->fd, &value, sizeof(value)) < 0) {
+		RTE_LOG(ERR, EAL,
+			"Error disabling interrupts for fd %d (%s)\n",
+			intr_handle->fd, strerror(errno));
+		return -1;
+	}
+	return 0;
+}
+
+static int
+uio_intr_enable(struct rte_intr_handle *intr_handle)
+{
+	const int value = 1;
+
+	if (write(intr_handle->fd, &value, sizeof(value)) < 0) {
+		RTE_LOG(ERR, EAL,
+			"Error enabling interrupts for fd %d (%s)\n",
+			intr_handle->fd, strerror(errno));
+		return -1;
+	}
+	return 0;
+}
+
+int
+rte_intr_callback_register(struct rte_intr_handle *intr_handle,
+			rte_intr_callback_fn cb, void *cb_arg)
+{
+	int ret, wake_thread;
+	struct rte_intr_source *src;
+	struct rte_intr_callback *callback;
+
+	wake_thread = 0;
+
+	/* first do parameter checking */
+	if (intr_handle == NULL || intr_handle->fd < 0 || cb == NULL) {
+		RTE_LOG(ERR, EAL,
+			"Registering with invalid input parameter\n");
+		return -EINVAL;
+	}
+
+	/* allocate a new interrupt callback entity */
+	callback = rte_zmalloc("interrupt callback list",
+				sizeof(*callback), 0);
+	if (callback == NULL) {
+		RTE_LOG(ERR, EAL, "Can not allocate memory\n");
+		return -ENOMEM;
+	}
+	callback->cb_fn = cb;
+	callback->cb_arg = cb_arg;
+
+	rte_spinlock_lock(&intr_lock);
+
+	/* check if there is at least one callback registered for the fd */
+	TAILQ_FOREACH(src, &intr_sources, next) {
+		if (src->intr_handle.fd == intr_handle->fd) {
+			/* we had no interrupts for this */
+			if TAILQ_EMPTY(&src->callbacks)
+				wake_thread = 1;
+
+			TAILQ_INSERT_TAIL(&(src->callbacks), callback, next);
+			ret = 0;
+			break;
+		}
+	}
+
+	/* no existing callbacks for this - add new source */
+	if (src == NULL) {
+		if ((src = rte_zmalloc("interrupt source list",
+				sizeof(*src), 0)) == NULL) {
+			RTE_LOG(ERR, EAL, "Can not allocate memory\n");
+			rte_free(callback);
+			ret = -ENOMEM;
+		} else {
+			src->intr_handle = *intr_handle;
+			TAILQ_INIT(&src->callbacks);
+			TAILQ_INSERT_TAIL(&(src->callbacks), callback, next);
+			TAILQ_INSERT_TAIL(&intr_sources, src, next);
+			wake_thread = 1;
+			ret = 0;
+		}
+	}
+
+	rte_spinlock_unlock(&intr_lock);
+
+	/**
+	 * check if need to notify the pipe fd waited by epoll_wait to
+	 * rebuild the wait list.
+	 */
+	if (wake_thread)
+		if (write(intr_pipe.writefd, "1", 1) < 0)
+			return -EPIPE;
+
+	return ret;
+}
+
+int
+rte_intr_callback_unregister(struct rte_intr_handle *intr_handle,
+			rte_intr_callback_fn cb_fn, void *cb_arg)
+{
+	int ret;
+	struct rte_intr_source *src;
+	struct rte_intr_callback *cb, *next;
+
+	/* do parameter checking first */
+	if (intr_handle == NULL || intr_handle->fd < 0) {
+		RTE_LOG(ERR, EAL,
+		"Unregistering with invalid input parameter\n");
+		return -EINVAL;
+	}
+
+	rte_spinlock_lock(&intr_lock);
+
+	/* check if the insterrupt source for the fd is existent */
+	TAILQ_FOREACH(src, &intr_sources, next)
+		if (src->intr_handle.fd == intr_handle->fd)
+			break;
+
+	/* No interrupt source registered for the fd */
+	if (src == NULL) {
+		ret = -ENOENT;
+
+	/* interrupt source has some active callbacks right now. */
+	} else if (src->active != 0) {
+		ret = -EAGAIN;
+
+	/* ok to remove. */
+	} else {
+		ret = 0;
+
+		/*walk through the callbacks and remove all that match. */
+		for (cb = TAILQ_FIRST(&src->callbacks); cb != NULL; cb = next) {
+
+			next = TAILQ_NEXT(cb, next);
+
+			if (cb->cb_fn == cb_fn && (cb_arg == (void *)-1 ||
+					cb->cb_arg == cb_arg)) {
+				TAILQ_REMOVE(&src->callbacks, cb, next);
+				rte_free(cb);
+				ret++;
+			}
+		}
+
+		/* all callbacks for that source are removed. */
+		if (TAILQ_EMPTY(&src->callbacks)) {
+			TAILQ_REMOVE(&intr_sources, src, next);
+			rte_free(src);
+		}
+	}
+
+	rte_spinlock_unlock(&intr_lock);
+
+	/* notify the pipe fd waited by epoll_wait to rebuild the wait list */
+	if (ret >= 0 && write(intr_pipe.writefd, "1", 1) < 0) {
+		ret = -EPIPE;
+	}
+
+	return ret;
+}
+
+int
+rte_intr_enable(struct rte_intr_handle *intr_handle)
+{
+	if (!intr_handle || intr_handle->fd < 0 || intr_handle->uio_cfg_fd < 0)
+		return -1;
+
+	switch (intr_handle->type){
+	/* write to the uio fd to enable the interrupt */
+	case RTE_INTR_HANDLE_UIO:
+		if (uio_intr_enable(intr_handle))
+			return -1;
+		break;
+	case RTE_INTR_HANDLE_UIO_INTX:
+		if (uio_intx_intr_enable(intr_handle))
+			return -1;
+		break;
+	/* not used at this moment */
+	case RTE_INTR_HANDLE_ALARM:
+		return -1;
+#ifdef VFIO_PRESENT
+	case RTE_INTR_HANDLE_VFIO_MSIX:
+		if (vfio_enable_msix(intr_handle))
+			return -1;
+		break;
+	case RTE_INTR_HANDLE_VFIO_MSI:
+		if (vfio_enable_msi(intr_handle))
+			return -1;
+		break;
+	case RTE_INTR_HANDLE_VFIO_LEGACY:
+		if (vfio_enable_intx(intr_handle))
+			return -1;
+		break;
+#endif
+	/* unknown handle type */
+	default:
+		RTE_LOG(ERR, EAL,
+			"Unknown handle type of fd %d\n",
+					intr_handle->fd);
+		return -1;
+	}
+
+	return 0;
+}
+
+int
+rte_intr_disable(struct rte_intr_handle *intr_handle)
+{
+	if (!intr_handle || intr_handle->fd < 0 || intr_handle->uio_cfg_fd < 0)
+		return -1;
+
+	switch (intr_handle->type){
+	/* write to the uio fd to disable the interrupt */
+	case RTE_INTR_HANDLE_UIO:
+		if (uio_intr_disable(intr_handle))
+			return -1;
+		break;
+	case RTE_INTR_HANDLE_UIO_INTX:
+		if (uio_intx_intr_disable(intr_handle))
+			return -1;
+		break;
+	/* not used at this moment */
+	case RTE_INTR_HANDLE_ALARM:
+		return -1;
+#ifdef VFIO_PRESENT
+	case RTE_INTR_HANDLE_VFIO_MSIX:
+		if (vfio_disable_msix(intr_handle))
+			return -1;
+		break;
+	case RTE_INTR_HANDLE_VFIO_MSI:
+		if (vfio_disable_msi(intr_handle))
+			return -1;
+		break;
+	case RTE_INTR_HANDLE_VFIO_LEGACY:
+		if (vfio_disable_intx(intr_handle))
+			return -1;
+		break;
+#endif
+	/* unknown handle type */
+	default:
+		RTE_LOG(ERR, EAL,
+			"Unknown handle type of fd %d\n",
+					intr_handle->fd);
+		return -1;
+	}
+
+	return 0;
+}
+
+static int
+eal_intr_process_interrupts(struct epoll_event *events, int nfds)
+{
+	int n, bytes_read;
+	struct rte_intr_source *src;
+	struct rte_intr_callback *cb;
+	union rte_intr_read_buffer buf;
+	struct rte_intr_callback active_cb;
+
+	for (n = 0; n < nfds; n++) {
+
+		/**
+		 * if the pipe fd is ready to read, return out to
+		 * rebuild the wait list.
+		 */
+		if (events[n].data.fd == intr_pipe.readfd){
+			int r = read(intr_pipe.readfd, buf.charbuf,
+					sizeof(buf.charbuf));
+			RTE_SET_USED(r);
+			return -1;
+		}
+		rte_spinlock_lock(&intr_lock);
+		TAILQ_FOREACH(src, &intr_sources, next)
+			if (src->intr_handle.fd ==
+					events[n].data.fd)
+				break;
+		if (src == NULL){
+			rte_spinlock_unlock(&intr_lock);
+			continue;
+		}
+
+		/* mark this interrupt source as active and release the lock. */
+		src->active = 1;
+		rte_spinlock_unlock(&intr_lock);
+
+		/* set the length to be read dor different handle type */
+		switch (src->intr_handle.type) {
+		case RTE_INTR_HANDLE_UIO:
+		case RTE_INTR_HANDLE_UIO_INTX:
+			bytes_read = sizeof(buf.uio_intr_count);
+			break;
+		case RTE_INTR_HANDLE_ALARM:
+			bytes_read = sizeof(buf.timerfd_num);
+			break;
+#ifdef VFIO_PRESENT
+		case RTE_INTR_HANDLE_VFIO_MSIX:
+		case RTE_INTR_HANDLE_VFIO_MSI:
+		case RTE_INTR_HANDLE_VFIO_LEGACY:
+			bytes_read = sizeof(buf.vfio_intr_count);
+			break;
+#endif
+		case RTE_INTR_HANDLE_EXT:
+		default:
+			bytes_read = 1;
+			break;
+		}
+
+		if (src->intr_handle.type != RTE_INTR_HANDLE_EXT) {
+			/**
+			 * read out to clear the ready-to-be-read flag
+			 * for epoll_wait.
+			 */
+			bytes_read = read(events[n].data.fd, &buf, bytes_read);
+			if (bytes_read < 0) {
+				if (errno == EINTR || errno == EWOULDBLOCK)
+					continue;
+
+				RTE_LOG(ERR, EAL, "Error reading from file "
+					"descriptor %d: %s\n",
+					events[n].data.fd,
+					strerror(errno));
+			} else if (bytes_read == 0)
+				RTE_LOG(ERR, EAL, "Read nothing from file "
+					"descriptor %d\n", events[n].data.fd);
+		}
+
+		/* grab a lock, again to call callbacks and update status. */
+		rte_spinlock_lock(&intr_lock);
+
+		if (bytes_read > 0) {
+
+			/* Finally, call all callbacks. */
+			TAILQ_FOREACH(cb, &src->callbacks, next) {
+
+				/* make a copy and unlock. */
+				active_cb = *cb;
+				rte_spinlock_unlock(&intr_lock);
+
+				/* call the actual callback */
+				active_cb.cb_fn(&src->intr_handle,
+					active_cb.cb_arg);
+
+				/*get the lock back. */
+				rte_spinlock_lock(&intr_lock);
+			}
+		}
+
+		/* we done with that interrupt source, release it. */
+		src->active = 0;
+		rte_spinlock_unlock(&intr_lock);
+	}
+
+	return 0;
+}
+
+/**
+ * It handles all the interrupts.
+ *
+ * @param pfd
+ *  epoll file descriptor.
+ * @param totalfds
+ *  The number of file descriptors added in epoll.
+ *
+ * @return
+ *  void
+ */
+static void
+eal_intr_handle_interrupts(int pfd, unsigned totalfds)
+{
+	struct epoll_event events[totalfds];
+	int nfds = 0;
+
+	for(;;) {
+		nfds = epoll_wait(pfd, events, totalfds,
+			EAL_INTR_EPOLL_WAIT_FOREVER);
+		/* epoll_wait fail */
+		if (nfds < 0) {
+			if (errno == EINTR)
+				continue;
+			RTE_LOG(ERR, EAL,
+				"epoll_wait returns with fail\n");
+			return;
+		}
+		/* epoll_wait timeout, will never happens here */
+		else if (nfds == 0)
+			continue;
+		/* epoll_wait has at least one fd ready to read */
+		if (eal_intr_process_interrupts(events, nfds) < 0)
+			return;
+	}
+}
+
+/**
+ * It builds/rebuilds up the epoll file descriptor with all the
+ * file descriptors being waited on. Then handles the interrupts.
+ *
+ * @param arg
+ *  pointer. (unused)
+ *
+ * @return
+ *  never return;
+ */
+static __attribute__((noreturn)) void *
+eal_intr_thread_main(__rte_unused void *arg)
+{
+	struct epoll_event ev;
+
+	/* host thread, never break out */
+	for (;;) {
+		/* build up the epoll fd with all descriptors we are to
+		 * wait on then pass it to the handle_interrupts function
+		 */
+		static struct epoll_event pipe_event = {
+			.events = EPOLLIN | EPOLLPRI,
+		};
+		struct rte_intr_source *src;
+		unsigned numfds = 0;
+
+		/* create epoll fd */
+		int pfd = epoll_create(1);
+		if (pfd < 0)
+			rte_panic("Cannot create epoll instance\n");
+
+		pipe_event.data.fd = intr_pipe.readfd;
+		/**
+		 * add pipe fd into wait list, this pipe is used to
+		 * rebuild the wait list.
+		 */
+		if (epoll_ctl(pfd, EPOLL_CTL_ADD, intr_pipe.readfd,
+						&pipe_event) < 0) {
+			rte_panic("Error adding fd to %d epoll_ctl, %s\n",
+					intr_pipe.readfd, strerror(errno));
+		}
+		numfds++;
+
+		rte_spinlock_lock(&intr_lock);
+
+		TAILQ_FOREACH(src, &intr_sources, next) {
+			if (src->callbacks.tqh_first == NULL)
+				continue; /* skip those with no callbacks */
+			ev.events = EPOLLIN | EPOLLPRI;
+			ev.data.fd = src->intr_handle.fd;
+
+			/**
+			 * add all the uio device file descriptor
+			 * into wait list.
+			 */
+			if (epoll_ctl(pfd, EPOLL_CTL_ADD,
+					src->intr_handle.fd, &ev) < 0){
+				rte_panic("Error adding fd %d epoll_ctl, %s\n",
+					src->intr_handle.fd, strerror(errno));
+			}
+			else
+				numfds++;
+		}
+		rte_spinlock_unlock(&intr_lock);
+		/* serve the interrupt */
+		eal_intr_handle_interrupts(pfd, numfds);
+
+		/**
+		 * when we return, we need to rebuild the
+		 * list of fds to monitor.
+		 */
+		close(pfd);
+	}
+}
+
+int
+rte_eal_intr_init(void)
+{
+	int ret = 0, ret_1 = 0;
+	char thread_name[RTE_MAX_THREAD_NAME_LEN];
+
+	/* init the global interrupt source head */
+	TAILQ_INIT(&intr_sources);
+
+	/**
+	 * create a pipe which will be waited by epoll and notified to
+	 * rebuild the wait list of epoll.
+	 */
+	if (pipe(intr_pipe.pipefd) < 0)
+		return -1;
+
+	/* create the host thread to wait/handle the interrupt */
+	ret = pthread_create(&intr_thread, NULL,
+			eal_intr_thread_main, NULL);
+	if (ret != 0) {
+		RTE_LOG(ERR, EAL,
+			"Failed to create thread for interrupt handling\n");
+	} else {
+		/* Set thread_name for aid in debugging. */
+		snprintf(thread_name, RTE_MAX_THREAD_NAME_LEN,
+			"eal-intr-thread");
+		ret_1 = rte_thread_setname(intr_thread, thread_name);
+		if (ret_1 != 0)
+			RTE_LOG(ERR, EAL,
+			"Failed to set thread name for interrupt handling\n");
+	}
+
+	return -ret;
+}
+
+static void
+eal_intr_proc_rxtx_intr(int fd, const struct rte_intr_handle *intr_handle)
+{
+	union rte_intr_read_buffer buf;
+	int bytes_read = 1;
+	int nbytes;
+
+	switch (intr_handle->type) {
+	case RTE_INTR_HANDLE_UIO:
+	case RTE_INTR_HANDLE_UIO_INTX:
+		bytes_read = sizeof(buf.uio_intr_count);
+		break;
+#ifdef VFIO_PRESENT
+	case RTE_INTR_HANDLE_VFIO_MSIX:
+	case RTE_INTR_HANDLE_VFIO_MSI:
+	case RTE_INTR_HANDLE_VFIO_LEGACY:
+		bytes_read = sizeof(buf.vfio_intr_count);
+		break;
+#endif
+	default:
+		bytes_read = 1;
+		RTE_LOG(INFO, EAL, "unexpected intr type\n");
+		break;
+	}
+
+	/**
+	 * read out to clear the ready-to-be-read flag
+	 * for epoll_wait.
+	 */
+	do {
+		nbytes = read(fd, &buf, bytes_read);
+		if (nbytes < 0) {
+			if (errno == EINTR || errno == EWOULDBLOCK ||
+			    errno == EAGAIN)
+				continue;
+			RTE_LOG(ERR, EAL,
+				"Error reading from fd %d: %s\n",
+				fd, strerror(errno));
+		} else if (nbytes == 0)
+			RTE_LOG(ERR, EAL, "Read nothing from fd %d\n", fd);
+		return;
+	} while (1);
+}
+
+static int
+eal_epoll_process_event(struct epoll_event *evs, unsigned int n,
+			struct rte_epoll_event *events)
+{
+	unsigned int i, count = 0;
+	struct rte_epoll_event *rev;
+
+	for (i = 0; i < n; i++) {
+		rev = evs[i].data.ptr;
+		if (!rev || !rte_atomic32_cmpset(&rev->status, RTE_EPOLL_VALID,
+						 RTE_EPOLL_EXEC))
+			continue;
+
+		events[count].status        = RTE_EPOLL_VALID;
+		events[count].fd            = rev->fd;
+		events[count].epfd          = rev->epfd;
+		events[count].epdata.event  = rev->epdata.event;
+		events[count].epdata.data   = rev->epdata.data;
+		if (rev->epdata.cb_fun)
+			rev->epdata.cb_fun(rev->fd,
+					   rev->epdata.cb_arg);
+
+		rte_compiler_barrier();
+		rev->status = RTE_EPOLL_VALID;
+		count++;
+	}
+	return count;
+}
+
+static inline int
+eal_init_tls_epfd(void)
+{
+	int pfd = epoll_create(255);
+
+	if (pfd < 0) {
+		RTE_LOG(ERR, EAL,
+			"Cannot create epoll instance\n");
+		return -1;
+	}
+	return pfd;
+}
+
+int
+rte_intr_tls_epfd(void)
+{
+	if (RTE_PER_LCORE(_epfd) == -1)
+		RTE_PER_LCORE(_epfd) = eal_init_tls_epfd();
+
+	return RTE_PER_LCORE(_epfd);
+}
+
+int
+rte_epoll_wait(int epfd, struct rte_epoll_event *events,
+	       int maxevents, int timeout)
+{
+	struct epoll_event evs[maxevents];
+	int rc;
+
+	if (!events) {
+		RTE_LOG(ERR, EAL, "rte_epoll_event can't be NULL\n");
+		return -1;
+	}
+
+	/* using per thread epoll fd */
+	if (epfd == RTE_EPOLL_PER_THREAD)
+		epfd = rte_intr_tls_epfd();
+
+	while (1) {
+		rc = epoll_wait(epfd, evs, maxevents, timeout);
+		if (likely(rc > 0)) {
+			/* epoll_wait has at least one fd ready to read */
+			rc = eal_epoll_process_event(evs, rc, events);
+			break;
+		} else if (rc < 0) {
+			if (errno == EINTR)
+				continue;
+			/* epoll_wait fail */
+			RTE_LOG(ERR, EAL, "epoll_wait returns with fail %s\n",
+				strerror(errno));
+			rc = -1;
+			break;
+		} else {
+			/* rc == 0, epoll_wait timed out */
+			break;
+		}
+	}
+
+	return rc;
+}
+
+static inline void
+eal_epoll_data_safe_free(struct rte_epoll_event *ev)
+{
+	while (!rte_atomic32_cmpset(&ev->status, RTE_EPOLL_VALID,
+				    RTE_EPOLL_INVALID))
+		while (ev->status != RTE_EPOLL_VALID)
+			rte_pause();
+	memset(&ev->epdata, 0, sizeof(ev->epdata));
+	ev->fd = -1;
+	ev->epfd = -1;
+}
+
+int
+rte_epoll_ctl(int epfd, int op, int fd,
+	      struct rte_epoll_event *event)
+{
+	struct epoll_event ev;
+
+	if (!event) {
+		RTE_LOG(ERR, EAL, "rte_epoll_event can't be NULL\n");
+		return -1;
+	}
+
+	/* using per thread epoll fd */
+	if (epfd == RTE_EPOLL_PER_THREAD)
+		epfd = rte_intr_tls_epfd();
+
+	if (op == EPOLL_CTL_ADD) {
+		event->status = RTE_EPOLL_VALID;
+		event->fd = fd;  /* ignore fd in event */
+		event->epfd = epfd;
+		ev.data.ptr = (void *)event;
+	}
+
+	ev.events = event->epdata.event;
+	if (epoll_ctl(epfd, op, fd, &ev) < 0) {
+		RTE_LOG(ERR, EAL, "Error op %d fd %d epoll_ctl, %s\n",
+			op, fd, strerror(errno));
+		if (op == EPOLL_CTL_ADD)
+			/* rollback status when CTL_ADD fail */
+			event->status = RTE_EPOLL_INVALID;
+		return -1;
+	}
+
+	if (op == EPOLL_CTL_DEL && event->status != RTE_EPOLL_INVALID)
+		eal_epoll_data_safe_free(event);
+
+	return 0;
+}
+
+int
+rte_intr_rx_ctl(struct rte_intr_handle *intr_handle, int epfd,
+		int op, unsigned int vec, void *data)
+{
+	struct rte_epoll_event *rev;
+	struct rte_epoll_data *epdata;
+	int epfd_op;
+	unsigned int efd_idx;
+	int rc = 0;
+
+	efd_idx = (vec >= RTE_INTR_VEC_RXTX_OFFSET) ?
+		(vec - RTE_INTR_VEC_RXTX_OFFSET) : vec;
+
+	if (!intr_handle || intr_handle->nb_efd == 0 ||
+	    efd_idx >= intr_handle->nb_efd) {
+		RTE_LOG(ERR, EAL, "Wrong intr vector number.\n");
+		return -EPERM;
+	}
+
+	switch (op) {
+	case RTE_INTR_EVENT_ADD:
+		epfd_op = EPOLL_CTL_ADD;
+		rev = &intr_handle->elist[efd_idx];
+		if (rev->status != RTE_EPOLL_INVALID) {
+			RTE_LOG(INFO, EAL, "Event already been added.\n");
+			return -EEXIST;
+		}
+
+		/* attach to intr vector fd */
+		epdata = &rev->epdata;
+		epdata->event  = EPOLLIN | EPOLLPRI | EPOLLET;
+		epdata->data   = data;
+		epdata->cb_fun = (rte_intr_event_cb_t)eal_intr_proc_rxtx_intr;
+		epdata->cb_arg = (void *)intr_handle;
+		rc = rte_epoll_ctl(epfd, epfd_op,
+				   intr_handle->efds[efd_idx], rev);
+		if (!rc)
+			RTE_LOG(DEBUG, EAL,
+				"efd %d associated with vec %d added on epfd %d"
+				"\n", rev->fd, vec, epfd);
+		else
+			rc = -EPERM;
+		break;
+	case RTE_INTR_EVENT_DEL:
+		epfd_op = EPOLL_CTL_DEL;
+		rev = &intr_handle->elist[efd_idx];
+		if (rev->status == RTE_EPOLL_INVALID) {
+			RTE_LOG(INFO, EAL, "Event does not exist.\n");
+			return -EPERM;
+		}
+
+		rc = rte_epoll_ctl(rev->epfd, epfd_op, rev->fd, rev);
+		if (rc)
+			rc = -EPERM;
+		break;
+	default:
+		RTE_LOG(ERR, EAL, "event op type mismatch\n");
+		rc = -EPERM;
+	}
+
+	return rc;
+}
+
+int
+rte_intr_efd_enable(struct rte_intr_handle *intr_handle, uint32_t nb_efd)
+{
+	uint32_t i;
+	int fd;
+	uint32_t n = RTE_MIN(nb_efd, (uint32_t)RTE_MAX_RXTX_INTR_VEC_ID);
+
+	assert(nb_efd != 0);
+
+	if (intr_handle->type == RTE_INTR_HANDLE_VFIO_MSIX) {
+		for (i = 0; i < n; i++) {
+			fd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
+			if (fd < 0) {
+				RTE_LOG(ERR, EAL,
+					"can't setup eventfd, error %i (%s)\n",
+					errno, strerror(errno));
+				return -1;
+			}
+			intr_handle->efds[i] = fd;
+		}
+		intr_handle->nb_efd   = n;
+		intr_handle->max_intr = NB_OTHER_INTR + n;
+	} else {
+		intr_handle->efds[0]  = intr_handle->fd;
+		intr_handle->nb_efd   = RTE_MIN(nb_efd, 1U);
+		intr_handle->max_intr = NB_OTHER_INTR;
+	}
+
+	return 0;
+}
+
+void
+rte_intr_efd_disable(struct rte_intr_handle *intr_handle)
+{
+	uint32_t i;
+	struct rte_epoll_event *rev;
+
+	for (i = 0; i < intr_handle->nb_efd; i++) {
+		rev = &intr_handle->elist[i];
+		if (rev->status == RTE_EPOLL_INVALID)
+			continue;
+		if (rte_epoll_ctl(rev->epfd, EPOLL_CTL_DEL, rev->fd, rev)) {
+			/* force free if the entry valid */
+			eal_epoll_data_safe_free(rev);
+			rev->status = RTE_EPOLL_INVALID;
+		}
+	}
+
+	if (intr_handle->max_intr > intr_handle->nb_efd) {
+		for (i = 0; i < intr_handle->nb_efd; i++)
+			close(intr_handle->efds[i]);
+	}
+	intr_handle->nb_efd = 0;
+	intr_handle->max_intr = 0;
+}
+
+int
+rte_intr_dp_is_en(struct rte_intr_handle *intr_handle)
+{
+	return !(!intr_handle->nb_efd);
+}
+
+int
+rte_intr_allow_others(struct rte_intr_handle *intr_handle)
+{
+	if (!rte_intr_dp_is_en(intr_handle))
+		return 1;
+	else
+		return !!(intr_handle->max_intr - intr_handle->nb_efd);
+}
+
+int
+rte_intr_cap_multiple(struct rte_intr_handle *intr_handle)
+{
+	if (intr_handle->type == RTE_INTR_HANDLE_VFIO_MSIX)
+		return 1;
+
+	return 0;
+}