drivers/net/tap/tap_intr.c

   1 /* SPDX-License-Identifier: BSD-3-Clause
   2  * Copyright 2018 Mellanox Technologies, Ltd
   3  */
   4
   5 /**
   6  * @file
   7  * Interrupts handling for tap driver.
   8  */
   9
  10 #include <assert.h>
  11 #include <errno.h>
  12 #include <fcntl.h>
  13 #include <signal.h>
  14 #include <stdint.h>
  15 #include <stdlib.h>
  16 #include <unistd.h>
  17
  18 #include <rte_eth_tap.h>
  19 #include <rte_errno.h>
  20 #include <rte_interrupts.h>
  21
  22
  23 /**
  24  * Unregister Rx interrupts free the queue interrupt vector.
  25  *
  26  * @param dev
  27  *   Pointer to the tap rte_eth_dev structure.
  28  */
  29 static void
  30 tap_rx_intr_vec_uninstall(struct rte_eth_dev *dev)
  31 {
  32         struct pmd_internals *pmd = dev->data->dev_private;
  33         struct rte_intr_handle *intr_handle = &pmd->intr_handle;
  34
  35         rte_intr_free_epoll_fd(intr_handle);
  36         free(intr_handle->intr_vec);
  37         intr_handle->intr_vec = NULL;
  38         intr_handle->nb_efd = 0;
  39 }
  40
  41 /**
  42  * Allocate Rx queue interrupt vector and register Rx interrupts.
  43  *
  44  * @param dev
  45  *   Pointer to the tap rte_eth_dev device structure.
  46  *
  47  * @return
  48  *   0 on success, negative errno value otherwise and rte_errno is set.
  49  */
  50 static int
  51 tap_rx_intr_vec_install(struct rte_eth_dev *dev)
  52 {
  53         struct pmd_internals *pmd = dev->data->dev_private;
  54         unsigned int rxqs_n = pmd->dev->data->nb_rx_queues;
  55         struct rte_intr_handle *intr_handle = &pmd->intr_handle;
  56         unsigned int n = RTE_MIN(rxqs_n, (uint32_t)RTE_MAX_RXTX_INTR_VEC_ID);
  57         unsigned int i;
  58         unsigned int count = 0;
  59
  60         if (!dev->data->dev_conf.intr_conf.rxq)
  61                 return 0;
  62         intr_handle->intr_vec = malloc(sizeof(intr_handle->intr_vec[rxqs_n]));
  63         if (intr_handle->intr_vec == NULL) {
  64                 rte_errno = ENOMEM;
  65                 TAP_LOG(ERR,
  66                         "failed to allocate memory for interrupt vector,"
  67                         " Rx interrupts will not be supported");
  68                 return -rte_errno;
  69         }
  70         for (i = 0; i < n; i++) {
  71                 struct rx_queue *rxq = pmd->dev->data->rx_queues[i];
  72
  73                 /* Skip queues that cannot request interrupts. */
  74                 if (!rxq || rxq->fd <= 0) {
  75                         /* Use invalid intr_vec[] index to disable entry. */
  76                         intr_handle->intr_vec[i] =
  77                                 RTE_INTR_VEC_RXTX_OFFSET +
  78                                 RTE_MAX_RXTX_INTR_VEC_ID;
  79                         continue;
  80                 }
  81                 intr_handle->intr_vec[i] = RTE_INTR_VEC_RXTX_OFFSET + count;
  82                 intr_handle->efds[count] = rxq->fd;
  83                 count++;
  84         }
  85         if (!count)
  86                 tap_rx_intr_vec_uninstall(dev);
  87         else
  88                 intr_handle->nb_efd = count;
  89         return 0;
  90 }
  91
  92 /**
  93  * Register or unregister the Rx interrupts.
  94  *
  95  * @param dev
  96  *   Pointer to the tap rte_eth_dev device structure.
  97  * @param set
  98  *   should the operation be register or unregister the interrupts.
  99  *
 100  * @return
 101  *   0 on success, negative errno value otherwise and rte_errno is set.
 102  */
 103 int
 104 tap_rx_intr_vec_set(struct rte_eth_dev *dev, int set)
 105 {
 106         tap_rx_intr_vec_uninstall(dev);
 107         if (set)
 108                 return tap_rx_intr_vec_install(dev);
 109         return 0;
 110 }