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 <errno.h>
  11 #include <fcntl.h>
  12 #include <signal.h>
  13 #include <stdint.h>
  14 #include <stdlib.h>
  15 #include <unistd.h>
  16
  17 #include <rte_eth_tap.h>
  18 #include <rte_errno.h>
  19 #include <rte_interrupts.h>
  20
  21
  22 /**
  23  * Unregister Rx interrupts free the queue interrupt vector.
  24  *
  25  * @param dev
  26  *   Pointer to the tap rte_eth_dev structure.
  27  */
  28 static void
  29 tap_rx_intr_vec_uninstall(struct rte_eth_dev *dev)
  30 {
  31         struct pmd_internals *pmd = dev->data->dev_private;
  32         struct rte_intr_handle *intr_handle = pmd->intr_handle;
  33
  34         rte_intr_free_epoll_fd(intr_handle);
  35         rte_intr_vec_list_free(intr_handle);
  36         rte_intr_nb_efd_set(intr_handle, 0);
  37 }
  38
  39 /**
  40  * Allocate Rx queue interrupt vector and register Rx interrupts.
  41  *
  42  * @param dev
  43  *   Pointer to the tap rte_eth_dev device structure.
  44  *
  45  * @return
  46  *   0 on success, negative errno value otherwise and rte_errno is set.
  47  */
  48 static int
  49 tap_rx_intr_vec_install(struct rte_eth_dev *dev)
  50 {
  51         struct pmd_internals *pmd = dev->data->dev_private;
  52         struct pmd_process_private *process_private = dev->process_private;
  53         unsigned int rxqs_n = pmd->dev->data->nb_rx_queues;
  54         struct rte_intr_handle *intr_handle = pmd->intr_handle;
  55         unsigned int n = RTE_MIN(rxqs_n, (uint32_t)RTE_MAX_RXTX_INTR_VEC_ID);
  56         unsigned int i;
  57         unsigned int count = 0;
  58
  59         if (!dev->data->dev_conf.intr_conf.rxq)
  60                 return 0;
  61
  62         if (rte_intr_vec_list_alloc(intr_handle, NULL, rxqs_n)) {
  63                 rte_errno = ENOMEM;
  64                 TAP_LOG(ERR,
  65                         "failed to allocate memory for interrupt vector,"
  66                         " Rx interrupts will not be supported");
  67                 return -rte_errno;
  68         }
  69         for (i = 0; i < n; i++) {
  70                 struct rx_queue *rxq = pmd->dev->data->rx_queues[i];
  71
  72                 /* Skip queues that cannot request interrupts. */
  73                 if (!rxq || process_private->rxq_fds[i] == -1) {
  74                         /* Use invalid intr_vec[] index to disable entry. */
  75                         if (rte_intr_vec_list_index_set(intr_handle, i,
  76                         RTE_INTR_VEC_RXTX_OFFSET + RTE_MAX_RXTX_INTR_VEC_ID))
  77                                 return -rte_errno;
  78                         continue;
  79                 }
  80                 if (rte_intr_vec_list_index_set(intr_handle, i,
  81                                         RTE_INTR_VEC_RXTX_OFFSET + count))
  82                         return -rte_errno;
  83                 if (rte_intr_efds_index_set(intr_handle, count,
  84                                                    process_private->rxq_fds[i]))
  85                         return -rte_errno;
  86                 count++;
  87         }
  88         if (!count)
  89                 tap_rx_intr_vec_uninstall(dev);
  90         else if (rte_intr_nb_efd_set(intr_handle, count))
  91                 return -rte_errno;
  92         return 0;
  93 }
  94
  95 /**
  96  * Register or unregister the Rx interrupts.
  97  *
  98  * @param dev
  99  *   Pointer to the tap rte_eth_dev device structure.
 100  * @param set
 101  *   should the operation be register or unregister the interrupts.
 102  *
 103  * @return
 104  *   0 on success, negative errno value otherwise and rte_errno is set.
 105  */
 106 int
 107 tap_rx_intr_vec_set(struct rte_eth_dev *dev, int set)
 108 {
 109         tap_rx_intr_vec_uninstall(dev);
 110         if (set)
 111                 return tap_rx_intr_vec_install(dev);
 112         return 0;
 113 }