/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2014 Intel Corporation
 */

#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 <stdbool.h>

#include <rte_common.h>
#include <rte_interrupts.h>
#include <rte_memory.h>
#include <rte_launch.h>
#include <rte_eal.h>
#include <rte_per_lcore.h>
#include <rte_lcore.h>
#include <rte_branch_prediction.h>
#include <rte_debug.h>
#include <rte_log.h>
#include <rte_errno.h>
#include <rte_spinlock.h>
#include <rte_pause.h>
#include <rte_vfio.h>
#include <rte_eal_trace.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 */
        uint8_t pending_delete;      /**< delete after callback is called */
        rte_intr_unregister_callback_fn ucb_fn; /**< fn to call before cb is deleted */
};

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(const 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(const 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_MASK;
        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 masking 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;
}

/* unmask/ack legacy (INTx) interrupts */
static int
vfio_ack_intx(const struct rte_intr_handle *intr_handle)
{
        struct vfio_irq_set irq_set;

        /* unmask INTx */
        memset(&irq_set, 0, sizeof(irq_set));
        irq_set.argsz = sizeof(irq_set);
        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;

        if (ioctl(intr_handle->vfio_dev_fd, VFIO_DEVICE_SET_IRQS, &irq_set)) {
                RTE_LOG(ERR, EAL, "Error unmasking INTx interrupts for fd %d\n",
                        intr_handle->fd);
                return -1;
        }
        return 0;
}

/* enable MSI interrupts */
static int
vfio_enable_msi(const 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(const 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(const 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;
        /* 0 < irq_set->count < RTE_MAX_RXTX_INTR_VEC_ID + 1 */
        irq_set->count = intr_handle->max_intr ?
                (intr_handle->max_intr > RTE_MAX_RXTX_INTR_VEC_ID + 1 ?
                RTE_MAX_RXTX_INTR_VEC_ID + 1 : intr_handle->max_intr) : 1;
        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(const 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;
}

#ifdef HAVE_VFIO_DEV_REQ_INTERFACE
/* enable req notifier */
static int
vfio_enable_req(const 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_REQ_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 req interrupts for fd %d\n",
                                                intr_handle->fd);
                return -1;
        }

        return 0;
}

/* disable req notifier */
static int
vfio_disable_req(const 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_REQ_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 req interrupts for fd %d\n",
                        intr_handle->fd);

        return ret;
}
#endif
#endif

static int
uio_intx_intr_disable(const 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(const 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(const 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(const 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(const 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 = calloc(1, sizeof(*callback));
        if (callback == NULL) {
                RTE_LOG(ERR, EAL, "Can not allocate memory\n");
                return -ENOMEM;
        }
        callback->cb_fn = cb;
        callback->cb_arg = cb_arg;
        callback->pending_delete = 0;
        callback->ucb_fn = NULL;

        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) {
                src = calloc(1, sizeof(*src));
                if (src == NULL) {
                        RTE_LOG(ERR, EAL, "Can not allocate memory\n");
                        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)
                        ret = -EPIPE;

        rte_eal_trace_intr_callback_register(intr_handle, cb, cb_arg, ret);
        return ret;
}

int
rte_intr_callback_unregister_pending(const struct rte_intr_handle *intr_handle,
                                rte_intr_callback_fn cb_fn, void *cb_arg,
                                rte_intr_unregister_callback_fn ucb_fn)
{
        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;

        /* only usable if the source is active */
        } else if (src->active == 0) {
                ret = -EAGAIN;

        } else {
                ret = 0;

                /* walk through the callbacks and mark 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)) {
                                cb->pending_delete = 1;
                                cb->ucb_fn = ucb_fn;
                                ret++;
                        }
                }
        }

        rte_spinlock_unlock(&intr_lock);

        return ret;
}

int
rte_intr_callback_unregister(const 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);
                                free(cb);
                                ret++;
                        }
                }

                /* all callbacks for that source are removed. */
                if (TAILQ_EMPTY(&src->callbacks)) {
                        TAILQ_REMOVE(&intr_sources, src, next);
                        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;
        }

        rte_eal_trace_intr_callback_unregister(intr_handle, cb_fn, cb_arg,
                ret);
        return ret;
}

int
rte_intr_enable(const struct rte_intr_handle *intr_handle)
{
        int rc = 0;

        if (intr_handle == NULL)
                return -1;

        if (intr_handle->type == RTE_INTR_HANDLE_VDEV) {
                rc = 0;
                goto out;
        }

        if (intr_handle->fd < 0 || intr_handle->uio_cfg_fd < 0) {
                rc = -1;
                goto out;
        }

        switch (intr_handle->type){
        /* write to the uio fd to enable the interrupt */
        case RTE_INTR_HANDLE_UIO:
                if (uio_intr_enable(intr_handle))
                        rc = -1;
                break;
        case RTE_INTR_HANDLE_UIO_INTX:
                if (uio_intx_intr_enable(intr_handle))
                        rc = -1;
                break;
        /* not used at this moment */
        case RTE_INTR_HANDLE_ALARM:
                rc = -1;
                break;
#ifdef VFIO_PRESENT
        case RTE_INTR_HANDLE_VFIO_MSIX:
                if (vfio_enable_msix(intr_handle))
                        rc = -1;
                break;
        case RTE_INTR_HANDLE_VFIO_MSI:
                if (vfio_enable_msi(intr_handle))
                        rc = -1;
                break;
        case RTE_INTR_HANDLE_VFIO_LEGACY:
                if (vfio_enable_intx(intr_handle))
                        rc = -1;
                break;
#ifdef HAVE_VFIO_DEV_REQ_INTERFACE
        case RTE_INTR_HANDLE_VFIO_REQ:
                if (vfio_enable_req(intr_handle))
                        rc = -1;
                break;
#endif
#endif
        /* not used at this moment */
        case RTE_INTR_HANDLE_DEV_EVENT:
                rc = -1;
                break;
        /* unknown handle type */
        default:
                RTE_LOG(ERR, EAL,
                        "Unknown handle type of fd %d\n",
                                        intr_handle->fd);
                rc = -1;
                break;
        }
out:
        rte_eal_trace_intr_enable(intr_handle, rc);
        return rc;
}

/**
 * PMD generally calls this function at the end of its IRQ callback.
 * Internally, it unmasks the interrupt if possible.
 *
 * For INTx, unmasking is required as the interrupt is auto-masked prior to
 * invoking callback.
 *
 * For MSI/MSI-X, unmasking is typically not needed as the interrupt is not
 * auto-masked. In fact, for interrupt handle types VFIO_MSIX and VFIO_MSI,
 * this function is no-op.
 */
int
rte_intr_ack(const struct rte_intr_handle *intr_handle)
{
        if (intr_handle && intr_handle->type == RTE_INTR_HANDLE_VDEV)
                return 0;

        if (!intr_handle || intr_handle->fd < 0 || intr_handle->uio_cfg_fd < 0)
                return -1;

        switch (intr_handle->type) {
        /* Both acking and enabling are same for UIO */
        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
        /* VFIO MSI* is implicitly acked unlike INTx, nothing to do */
        case RTE_INTR_HANDLE_VFIO_MSIX:
        case RTE_INTR_HANDLE_VFIO_MSI:
                return 0;
        case RTE_INTR_HANDLE_VFIO_LEGACY:
                if (vfio_ack_intx(intr_handle))
                        return -1;
                break;
#ifdef HAVE_VFIO_DEV_REQ_INTERFACE
        case RTE_INTR_HANDLE_VFIO_REQ:
                return -1;
#endif
#endif
        /* not used at this moment */
        case RTE_INTR_HANDLE_DEV_EVENT:
                return -1;
        /* 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(const struct rte_intr_handle *intr_handle)
{
        int rc = 0;

        if (intr_handle == NULL)
                return -1;

        if (intr_handle->type == RTE_INTR_HANDLE_VDEV) {
                rc = 0;
                goto out;
        }

        if (intr_handle->fd < 0 || intr_handle->uio_cfg_fd < 0) {
                rc = -1;
                goto out;
        }

        switch (intr_handle->type){
        /* write to the uio fd to disable the interrupt */
        case RTE_INTR_HANDLE_UIO:
                if (uio_intr_disable(intr_handle))
                        rc = -1;
                break;
        case RTE_INTR_HANDLE_UIO_INTX:
                if (uio_intx_intr_disable(intr_handle))
                        rc = -1;
                break;
        /* not used at this moment */
        case RTE_INTR_HANDLE_ALARM:
                rc = -1;
                break;
#ifdef VFIO_PRESENT
        case RTE_INTR_HANDLE_VFIO_MSIX:
                if (vfio_disable_msix(intr_handle))
                        rc = -1;
                break;
        case RTE_INTR_HANDLE_VFIO_MSI:
                if (vfio_disable_msi(intr_handle))
                        rc = -1;
                break;
        case RTE_INTR_HANDLE_VFIO_LEGACY:
                if (vfio_disable_intx(intr_handle))
                        rc = -1;
                break;
#ifdef HAVE_VFIO_DEV_REQ_INTERFACE
        case RTE_INTR_HANDLE_VFIO_REQ:
                if (vfio_disable_req(intr_handle))
                        rc = -1;
                break;
#endif
#endif
        /* not used at this moment */
        case RTE_INTR_HANDLE_DEV_EVENT:
                rc = -1;
                break;
        /* unknown handle type */
        default:
                RTE_LOG(ERR, EAL,
                        "Unknown handle type of fd %d\n",
                                        intr_handle->fd);
                rc = -1;
                break;
        }
out:
        rte_eal_trace_intr_disable(intr_handle, rc);
        return rc;
}

static int
eal_intr_process_interrupts(struct epoll_event *events, int nfds)
{
        bool call = false;
        int n, bytes_read, rv;
        struct rte_intr_source *src;
        struct rte_intr_callback *cb, *next;
        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;
#ifdef HAVE_VFIO_DEV_REQ_INTERFACE
                case RTE_INTR_HANDLE_VFIO_REQ:
                        bytes_read = 0;
                        call = true;
                        break;
#endif
#endif
                case RTE_INTR_HANDLE_VDEV:
                case RTE_INTR_HANDLE_EXT:
                        bytes_read = 0;
                        call = true;
                        break;
                case RTE_INTR_HANDLE_DEV_EVENT:
                        bytes_read = 0;
                        call = true;
                        break;
                default:
                        bytes_read = 1;
                        break;
                }

                if (bytes_read > 0) {
                        /**
                         * 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));
                                /*
                                 * The device is unplugged or buggy, remove
                                 * it as an interrupt source and return to
                                 * force the wait list to be rebuilt.
                                 */
                                rte_spinlock_lock(&intr_lock);
                                TAILQ_REMOVE(&intr_sources, src, next);
                                rte_spinlock_unlock(&intr_lock);

                                for (cb = TAILQ_FIRST(&src->callbacks); cb;
                                                        cb = next) {
                                        next = TAILQ_NEXT(cb, next);
                                        TAILQ_REMOVE(&src->callbacks, cb, next);
                                        free(cb);
                                }
                                free(src);
                                return -1;
                        } else if (bytes_read == 0)
                                RTE_LOG(ERR, EAL, "Read nothing from file "
                                        "descriptor %d\n", events[n].data.fd);
                        else
                                call = true;
                }

                /* grab a lock, again to call callbacks and update status. */
                rte_spinlock_lock(&intr_lock);

                if (call) {

                        /* 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(active_cb.cb_arg);

                                /*get the lock back. */
                                rte_spinlock_lock(&intr_lock);
                        }
                }
                /* we done with that interrupt source, release it. */
                src->active = 0;

                rv = 0;

                /* check if any callback are supposed to be removed */
                for (cb = TAILQ_FIRST(&src->callbacks); cb != NULL; cb = next) {
                        next = TAILQ_NEXT(cb, next);
                        if (cb->pending_delete) {

                                TAILQ_REMOVE(&src->callbacks, cb, next);
                                if (cb->ucb_fn)
                                        cb->ucb_fn(&src->intr_handle, cb->cb_arg);
                                free(cb);
                                rv++;
                        }
                }

                /* all callbacks for that source are removed. */
                if (TAILQ_EMPTY(&src->callbacks)) {
                        TAILQ_REMOVE(&intr_sources, src, next);
                        free(src);
                }

                /* notify the pipe fd waited by epoll_wait to rebuild the wait list */
                if (rv > 0 && write(intr_pipe.writefd, "1", 1) < 0) {
                        rte_spinlock_unlock(&intr_lock);
                        return -EPIPE;
                }

                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 __rte_noreturn void *
eal_intr_thread_main(__rte_unused void *arg)
{
        /* 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) {
                        struct epoll_event ev;

                        if (src->callbacks.tqh_first == NULL)
                                continue; /* skip those with no callbacks */
                        memset(&ev, 0, sizeof(ev));
                        ev.events = EPOLLIN | EPOLLPRI | EPOLLRDHUP | EPOLLHUP;
                        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;

        /* 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) {
                rte_errno = errno;
                return -1;
        }

        /* create the host thread to wait/handle the interrupt */
        ret = rte_ctrl_thread_create(&intr_thread, "eal-intr-thread", NULL,
                        eal_intr_thread_main, NULL);
        if (ret != 0) {
                rte_errno = -ret;
                RTE_LOG(ERR, EAL,
                        "Failed to create thread 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 = 0;
        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
        case RTE_INTR_HANDLE_VDEV:
                bytes_read = intr_handle->efd_counter_size;
                /* For vdev, number of bytes to read is set by driver */
                break;
        case RTE_INTR_HANDLE_EXT:
                return;
        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.
         */
        if (bytes_read == 0)
                return;
        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;
        uint32_t valid_status;

        for (i = 0; i < n; i++) {
                rev = evs[i].data.ptr;
                valid_status =  RTE_EPOLL_VALID;
                /* ACQUIRE memory ordering here pairs with RELEASE
                 * ordering below acting as a lock to synchronize
                 * the event data updating.
                 */
                if (!rev || !__atomic_compare_exchange_n(&rev->status,
                                    &valid_status, RTE_EPOLL_EXEC, 0,
                                    __ATOMIC_ACQUIRE, __ATOMIC_RELAXED))
                        continue;

                events[count].status        = RTE_EPOLL_VALID;
                events[count].fd            = rev->fd;
                events[count].epfd          = rev->epfd;
                events[count].epdata.event  = evs[i].events;
                events[count].epdata.data   = rev->epdata.data;
                if (rev->epdata.cb_fun)
                        rev->epdata.cb_fun(rev->fd,
                                           rev->epdata.cb_arg);

                /* the status update should be observed after
                 * the other fields change.
                 */
                __atomic_store_n(&rev->status, RTE_EPOLL_VALID,
                                __ATOMIC_RELEASE);
                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);
}

static int
eal_epoll_wait(int epfd, struct rte_epoll_event *events,
               int maxevents, int timeout, bool interruptible)
{
        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) {
                                if (interruptible)
                                        return -1;
                                else
                                        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;
}

int
rte_epoll_wait(int epfd, struct rte_epoll_event *events,
               int maxevents, int timeout)
{
        return eal_epoll_wait(epfd, events, maxevents, timeout, false);
}

int
rte_epoll_wait_interruptible(int epfd, struct rte_epoll_event *events,
                             int maxevents, int timeout)
{
        return eal_epoll_wait(epfd, events, maxevents, timeout, true);
}

static inline void
eal_epoll_data_safe_free(struct rte_epoll_event *ev)
{
        uint32_t valid_status = RTE_EPOLL_VALID;

        while (!__atomic_compare_exchange_n(&ev->status, &valid_status,
                    RTE_EPOLL_INVALID, 0, __ATOMIC_ACQUIRE, __ATOMIC_RELAXED)) {
                while (__atomic_load_n(&ev->status,
                                __ATOMIC_RELAXED) != RTE_EPOLL_VALID)
                        rte_pause();
                valid_status = RTE_EPOLL_VALID;
        }
        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) {
                __atomic_store_n(&event->status, RTE_EPOLL_VALID,
                                __ATOMIC_RELAXED);
                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 */
                        __atomic_store_n(&event->status, RTE_EPOLL_INVALID,
                                        __ATOMIC_RELAXED);
                return -1;
        }

        if (op == EPOLL_CTL_DEL && __atomic_load_n(&event->status,
                        __ATOMIC_RELAXED) != 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 (__atomic_load_n(&rev->status,
                                __ATOMIC_RELAXED) != 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 (__atomic_load_n(&rev->status,
                                __ATOMIC_RELAXED) == 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;
}

void
rte_intr_free_epoll_fd(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 (__atomic_load_n(&rev->status,
                                __ATOMIC_RELAXED) == 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);
                }
        }
}

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 -errno;
                        }
                        intr_handle->efds[i] = fd;
                }
                intr_handle->nb_efd   = n;
                intr_handle->max_intr = NB_OTHER_INTR + n;
        } else if (intr_handle->type == RTE_INTR_HANDLE_VDEV) {
                /* only check, initialization would be done in vdev driver.*/
                if (intr_handle->efd_counter_size >
                    sizeof(union rte_intr_read_buffer)) {
                        RTE_LOG(ERR, EAL, "the efd_counter_size is oversized");
                        return -EINVAL;
                }
        } 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;

        rte_intr_free_epoll_fd(intr_handle);
        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;

        if (intr_handle->type == RTE_INTR_HANDLE_VDEV)
                return 1;

        return 0;
}

int rte_thread_is_intr(void)
{
        return pthread_equal(intr_thread, pthread_self());
}