net/tap: support Rx interrupt

This patch adds support for registering and waiting for Rx interrupts.
This allows applications to wait for Rx events from the PMD using the
DPDK rte_epoll subsystem.

Signed-off-by: Moti Haimovsky <motih@mellanox.com>
Acked-by: Pascal Mazon <pascal.mazon@6wind.com>

diff --git a/doc/guides/nics/features/tap.ini b/doc/guides/nics/features/tap.ini
index f0e893d..8bc5187 100644 (file)
--- a/doc/guides/nics/features/tap.ini
+++ b/doc/guides/nics/features/tap.ini
@@ -7,6 +7,7 @@
 Speed capabilities   = P
 Link status          = Y
 Link status event    = Y
+Rx interrupt         = Y
 Jumbo frame          = Y
 Promiscuous mode     = Y
 Allmulticast mode    = Y

diff --git a/drivers/net/tap/Makefile b/drivers/net/tap/Makefile
index 315c6bd..ccc5c5f 100644 (file)
--- a/drivers/net/tap/Makefile
+++ b/drivers/net/tap/Makefile
@@ -36,6 +36,7 @@ SRCS-$(CONFIG_RTE_LIBRTE_PMD_TAP) += tap_flow.c
 SRCS-$(CONFIG_RTE_LIBRTE_PMD_TAP) += tap_netlink.c
 SRCS-$(CONFIG_RTE_LIBRTE_PMD_TAP) += tap_tcmsgs.c
 SRCS-$(CONFIG_RTE_LIBRTE_PMD_TAP) += tap_bpf_api.c
+SRCS-$(CONFIG_RTE_LIBRTE_PMD_TAP) += tap_intr.c
 
 include $(RTE_SDK)/mk/rte.lib.mk
 

diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
index fd42572..29d6356 100644 (file)
--- a/drivers/net/tap/rte_eth_tap.c
+++ b/drivers/net/tap/rte_eth_tap.c
@@ -1218,7 +1218,7 @@ tap_dev_intr_handler(void *cb_arg)
 }
 
 static int
-tap_intr_handle_set(struct rte_eth_dev *dev, int set)
+tap_lsc_intr_handle_set(struct rte_eth_dev *dev, int set)
 {
        struct pmd_internals *pmd = dev->data->dev_private;
 
@@ -1243,6 +1243,20 @@ tap_intr_handle_set(struct rte_eth_dev *dev, int set)
                                            tap_dev_intr_handler, dev);
 }
 
+static int
+tap_intr_handle_set(struct rte_eth_dev *dev, int set)
+{
+       int err;
+
+       err = tap_lsc_intr_handle_set(dev, set);
+       if (err)
+               return err;
+       err = tap_rx_intr_vec_set(dev, set);
+       if (err && set)
+               tap_lsc_intr_handle_set(dev, 0);
+       return err;
+}
+
 static const uint32_t*
 tap_dev_supported_ptypes_get(struct rte_eth_dev *dev __rte_unused)
 {
@@ -1375,6 +1389,7 @@ eth_dev_tap_create(struct rte_vdev_device *vdev, char *tap_name,
 
        pmd->intr_handle.type = RTE_INTR_HANDLE_EXT;
        pmd->intr_handle.fd = -1;
+       dev->intr_handle = &pmd->intr_handle;
 
        /* Presetup the fds to -1 as being not valid */
        for (i = 0; i < RTE_PMD_TAP_MAX_QUEUES; i++) {

diff --git a/drivers/net/tap/rte_eth_tap.h b/drivers/net/tap/rte_eth_tap.h
index d4f1e6c..ed85244 100644 (file)
--- a/drivers/net/tap/rte_eth_tap.h
+++ b/drivers/net/tap/rte_eth_tap.h
@@ -106,4 +106,8 @@ struct pmd_internals {
        struct rte_intr_handle intr_handle;          /* LSC interrupt handle. */
 };
 
+/* tap_intr.c */
+
+int tap_rx_intr_vec_set(struct rte_eth_dev *dev, int set);
+
 #endif /* _RTE_ETH_TAP_H_ */

diff --git a/drivers/net/tap/tap_intr.c b/drivers/net/tap/tap_intr.c
new file mode 100644 (file)
index 0000000..b0e1991
--- /dev/null
+++ b/drivers/net/tap/tap_intr.c
@@ -0,0 +1,110 @@
+/* SPDX-License-Identifier: BSD-3-Clause
+ * Copyright 2018 Mellanox Technologies, Ltd.
+ */
+
+/**
+ * @file
+ * Interrupts handling for tap driver.
+ */
+
+#include <assert.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+#include <rte_eth_tap.h>
+#include <rte_errno.h>
+#include <rte_interrupts.h>
+
+
+/**
+ * Unregister Rx interrupts free the queue interrupt vector.
+ *
+ * @param dev
+ *   Pointer to the tap rte_eth_dev structure.
+ */
+static void
+tap_rx_intr_vec_uninstall(struct rte_eth_dev *dev)
+{
+       struct pmd_internals *pmd = dev->data->dev_private;
+       struct rte_intr_handle *intr_handle = &pmd->intr_handle;
+
+       rte_intr_free_epoll_fd(intr_handle);
+       free(intr_handle->intr_vec);
+       intr_handle->intr_vec = NULL;
+       intr_handle->nb_efd = 0;
+}
+
+/**
+ * Allocate Rx queue interrupt vector and register Rx interrupts.
+ *
+ * @param dev
+ *   Pointer to the tap rte_eth_dev device structure.
+ *
+ * @return
+ *   0 on success, negative errno value otherwise and rte_errno is set.
+ */
+static int
+tap_rx_intr_vec_install(struct rte_eth_dev *dev)
+{
+       struct pmd_internals *pmd = dev->data->dev_private;
+       unsigned int rxqs_n = pmd->dev->data->nb_rx_queues;
+       struct rte_intr_handle *intr_handle = &pmd->intr_handle;
+       unsigned int n = RTE_MIN(rxqs_n, (uint32_t)RTE_MAX_RXTX_INTR_VEC_ID);
+       unsigned int i;
+       unsigned int count = 0;
+
+       if (!dev->data->dev_conf.intr_conf.rxq)
+               return 0;
+       intr_handle->intr_vec = malloc(sizeof(intr_handle->intr_vec[rxqs_n]));
+       if (intr_handle->intr_vec == NULL) {
+               rte_errno = ENOMEM;
+               RTE_LOG(ERR, PMD,
+                       "failed to allocate memory for interrupt vector,"
+                       " Rx interrupts will not be supported");
+               return -rte_errno;
+       }
+       for (i = 0; i < n; i++) {
+               struct rx_queue *rxq = pmd->dev->data->rx_queues[i];
+
+               /* Skip queues that cannot request interrupts. */
+               if (!rxq || rxq->fd <= 0) {
+                       /* Use invalid intr_vec[] index to disable entry. */
+                       intr_handle->intr_vec[i] =
+                               RTE_INTR_VEC_RXTX_OFFSET +
+                               RTE_MAX_RXTX_INTR_VEC_ID;
+                       continue;
+               }
+               intr_handle->intr_vec[i] = RTE_INTR_VEC_RXTX_OFFSET + count;
+               intr_handle->efds[count] = rxq->fd;
+               count++;
+       }
+       if (!count)
+               tap_rx_intr_vec_uninstall(dev);
+       else
+               intr_handle->nb_efd = count;
+       return 0;
+}
+
+/**
+ * Register or unregister the Rx interrupts.
+ *
+ * @param dev
+ *   Pointer to the tap rte_eth_dev device structure.
+ * @param set
+ *   should the operation be register or unregister the interrupts.
+ *
+ * @return
+ *   0 on success, negative errno value otherwise and rte_errno is set.
+ */
+int
+tap_rx_intr_vec_set(struct rte_eth_dev *dev, int set)
+{
+       tap_rx_intr_vec_uninstall(dev);
+       if (set)
+               return tap_rx_intr_vec_install(dev);
+       return 0;
+}