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
tap_rx_intr_vec_uninstall(struct rte_eth_dev * dev)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
tap_rx_intr_vec_install(struct rte_eth_dev * dev)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 int fd = process_private->fds[i];
72
73 /* Skip queues that cannot request interrupts. */
74 if (!rxq || fd == -1) {
75 /* Use invalid intr_vec[] index to disable entry. */
76 /* Use invalid intr_vec[] index to disable entry. */
77 if (rte_intr_vec_list_index_set(intr_handle, i,
78 RTE_INTR_VEC_RXTX_OFFSET + RTE_MAX_RXTX_INTR_VEC_ID))
79 return -rte_errno;
80 continue;
81 }
82 if (rte_intr_vec_list_index_set(intr_handle, i,
83 RTE_INTR_VEC_RXTX_OFFSET + count))
84 return -rte_errno;
85 if (rte_intr_efds_index_set(intr_handle, count, fd))
86 return -rte_errno;
87 count++;
88 }
89 if (!count)
90 tap_rx_intr_vec_uninstall(dev);
91 else if (rte_intr_nb_efd_set(intr_handle, count))
92 return -rte_errno;
93 return 0;
94 }
95
96 /**
97 * Register or unregister the Rx interrupts.
98 *
99 * @param dev
100 * Pointer to the tap rte_eth_dev device structure.
101 * @param set
102 * should the operation be register or unregister the interrupts.
103 *
104 * @return
105 * 0 on success, negative errno value otherwise and rte_errno is set.
106 */
107 int
tap_rx_intr_vec_set(struct rte_eth_dev * dev,int set)108 tap_rx_intr_vec_set(struct rte_eth_dev *dev, int set)
109 {
110 tap_rx_intr_vec_uninstall(dev);
111 if (set)
112 return tap_rx_intr_vec_install(dev);
113 return 0;
114 }
115