[PATCH v2 2/2] net/mlx5: support user space rxq interrupt event

[Shahaf Shuler <shahafs@mellanox.com>]

Implement rxq interrupt callbacks

Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
---
 doc/guides/nics/features/mlx5.ini      |   1 +
 doc/guides/rel_notes/release_17_05.rst |   6 ++
 drivers/net/mlx5/Makefile              |   5 ++
 drivers/net/mlx5/mlx5.c                |   2 +
 drivers/net/mlx5/mlx5_rxq.c            | 126 ++++++++++++++++++++++++++++++++-
 drivers/net/mlx5/mlx5_rxtx.c           |  73 +++++++++++++++++++
 drivers/net/mlx5/mlx5_rxtx.h           |   7 ++
 drivers/net/mlx5/mlx5_trigger.c        |   9 +++
 8 files changed, 228 insertions(+), 1 deletion(-)

diff --git a/doc/guides/nics/features/mlx5.ini b/doc/guides/nics/features/mlx5.ini
index 1814f82..532c0ef 100644
--- a/doc/guides/nics/features/mlx5.ini
+++ b/doc/guides/nics/features/mlx5.ini
@@ -7,6 +7,7 @@
 Speed capabilities   = Y
 Link status          = Y
 Link status event    = Y
+Rx interrupt         = Y
 Queue start/stop     = Y
 MTU update           = Y
 Jumbo frame          = Y
diff --git a/doc/guides/rel_notes/release_17_05.rst b/doc/guides/rel_notes/release_17_05.rst
index 49e9640..f9f79c2 100644
--- a/doc/guides/rel_notes/release_17_05.rst
+++ b/doc/guides/rel_notes/release_17_05.rst
@@ -62,6 +62,11 @@ New Features
   Added support for Hardware TSO for tunneled and non-tunneled packets.
   Tunneling protocols supported are GRE and VXLAN.
 
+* **Added support for Rx interrupts on mlx5 driver.**
+
+  Rx queues can be armed with an interrupt which will trigger on the
+  next packet arrival.
+
 * **Added vmxnet3 version 3 support.**
 
   Added support for vmxnet3 version 3 which includes several
@@ -73,6 +78,7 @@ New Features
   * Generic flow API support for Ethernet, VLAN, IPv4, IPv6, UDP and TCP
     pattern items with QUEUE action for ingress traffic.
 
+
 Resolved Issues
 ---------------
 
diff --git a/drivers/net/mlx5/Makefile b/drivers/net/mlx5/Makefile
index 671089c..084044a 100644
--- a/drivers/net/mlx5/Makefile
+++ b/drivers/net/mlx5/Makefile
@@ -137,6 +137,11 @@ mlx5_autoconf.h.new: $(RTE_SDK)/buildtools/auto-config-h.sh
 		/usr/include/linux/ethtool.h \
 		enum ETHTOOL_LINK_MODE_100000baseKR4_Full_BIT \
 		$(AUTOCONF_OUTPUT)
+	$Q sh -- '$<' '$@' \
+		HAVE_UPDATE_CQ_CI \
+		infiniband/mlx5_hw.h \
+		func ibv_mlx5_exp_update_cq_ci \
+		$(AUTOCONF_OUTPUT)
 
 # Create mlx5_autoconf.h or update it in case it differs from the new one.
 
diff --git a/drivers/net/mlx5/mlx5.c b/drivers/net/mlx5/mlx5.c
index 6f42948..ebc7984 100644
--- a/drivers/net/mlx5/mlx5.c
+++ b/drivers/net/mlx5/mlx5.c
@@ -225,6 +225,8 @@
 	.rss_hash_update = mlx5_rss_hash_update,
 	.rss_hash_conf_get = mlx5_rss_hash_conf_get,
 	.filter_ctrl = mlx5_dev_filter_ctrl,
+	.rx_queue_intr_enable = mlx5_rx_intr_enable,
+	.rx_queue_intr_disable = mlx5_rx_intr_disable,
 };
 
 static struct {
diff --git a/drivers/net/mlx5/mlx5_rxq.c b/drivers/net/mlx5/mlx5_rxq.c
index 28e93d3..e6070a0 100644
--- a/drivers/net/mlx5/mlx5_rxq.c
+++ b/drivers/net/mlx5/mlx5_rxq.c
@@ -36,6 +36,7 @@
 #include <errno.h>
 #include <string.h>
 #include <stdint.h>
+#include <fcntl.h>
 
 /* Verbs header. */
 /* ISO C doesn't support unnamed structs/unions, disabling -pedantic. */
@@ -57,6 +58,7 @@
 #include <rte_malloc.h>
 #include <rte_ethdev.h>
 #include <rte_common.h>
+#include <rte_interrupts.h>
 #ifdef PEDANTIC
 #pragma GCC diagnostic error "-Wpedantic"
 #endif
@@ -773,6 +775,8 @@
 		claim_zero(ibv_exp_destroy_wq(rxq_ctrl->wq));
 	if (rxq_ctrl->cq != NULL)
 		claim_zero(ibv_destroy_cq(rxq_ctrl->cq));
+	if (rxq_ctrl->channel != NULL)
+		claim_zero(ibv_destroy_comp_channel(rxq_ctrl->channel));
 	if (rxq_ctrl->rd != NULL) {
 		struct ibv_exp_destroy_res_domain_attr attr = {
 			.comp_mask = 0,
@@ -1014,6 +1018,16 @@
 		      (void *)dev, strerror(ret));
 		goto error;
 	}
+	if (dev->data->dev_conf.intr_conf.rxq) {
+		tmpl.channel = ibv_create_comp_channel(priv->ctx);
+		if (tmpl.channel == NULL) {
+			dev->data->dev_conf.intr_conf.rxq = 0;
+			ret = ENOMEM;
+			ERROR("%p: Comp Channel creation failure: %s",
+			(void *)dev, strerror(ret));
+			goto error;
+		}
+	}
 	attr.cq = (struct ibv_exp_cq_init_attr){
 		.comp_mask = IBV_EXP_CQ_INIT_ATTR_RES_DOMAIN,
 		.res_domain = tmpl.rd,
@@ -1023,7 +1037,7 @@
 		attr.cq.flags |= IBV_EXP_CQ_COMPRESSED_CQE;
 		cqe_n = (desc * 2) - 1; /* Double the number of CQEs. */
 	}
-	tmpl.cq = ibv_exp_create_cq(priv->ctx, cqe_n, NULL, NULL, 0,
+	tmpl.cq = ibv_exp_create_cq(priv->ctx, cqe_n, NULL, tmpl.channel, 0,
 				    &attr.cq);
 	if (tmpl.cq == NULL) {
 		ret = ENOMEM;
@@ -1347,3 +1361,113 @@
 	rxq = (*priv->rxqs)[index];
 	return priv->dev->rx_pkt_burst(rxq, pkts, pkts_n);
 }
+
+/**
+ * Fill epoll fd list for rxq interrupts.
+ *
+ * @param priv
+ *   Private structure.
+ *
+ * @return
+ *   0 on success, negative on failure.
+ */
+int
+priv_intr_efd_enable(struct priv *priv)
+{
+	unsigned int i;
+	unsigned int rxqs_n = priv->rxqs_n;
+	unsigned int n = RTE_MIN(rxqs_n, (uint32_t)RTE_MAX_RXTX_INTR_VEC_ID);
+	struct rte_intr_handle *intr_handle = priv->dev->intr_handle;
+
+	if (n == 0)
+		return 0;
+	if (n < rxqs_n) {
+		WARN("rxqs num is larger than EAL max interrupt vector "
+		     "%u > %u unable to supprt rxq interrupts",
+		     rxqs_n, (uint32_t)RTE_MAX_RXTX_INTR_VEC_ID);
+		return -EINVAL;
+	}
+	intr_handle->type = RTE_INTR_HANDLE_EXT;
+	for (i = 0; i != n; ++i) {
+		struct rxq *rxq = (*priv->rxqs)[i];
+		struct rxq_ctrl *rxq_ctrl =
+			container_of(rxq, struct rxq_ctrl, rxq);
+		int fd = rxq_ctrl->channel->fd;
+		int flags;
+		int rc;
+
+		flags = fcntl(fd, F_GETFL);
+		rc = fcntl(fd, F_SETFL, flags | O_NONBLOCK);
+		if (rc < 0) {
+			WARN("failed to change rxq interrupt file "
+			     "descriptor %d for queue index %d", fd, i);
+			return -1;
+		}
+		intr_handle->efds[i] = fd;
+	}
+	intr_handle->nb_efd = n;
+	return 0;
+}
+
+/**
+ * Clean epoll fd list for rxq interrupts.
+ *
+ * @param priv
+ *   Private structure.
+ */
+void
+priv_intr_efd_disable(struct priv *priv)
+{
+	struct rte_intr_handle *intr_handle = priv->dev->intr_handle;
+
+	rte_intr_free_epoll_fd(intr_handle);
+}
+
+/**
+ * Create and init interrupt vector array.
+ *
+ * @param priv
+ *   Private structure.
+ *
+ * @return
+ *   0 on success, negative on failure.
+ */
+int
+priv_create_intr_vec(struct priv *priv)
+{
+	unsigned int rxqs_n = priv->rxqs_n;
+	unsigned int i;
+	struct rte_intr_handle *intr_handle = priv->dev->intr_handle;
+
+	if (rxqs_n == 0)
+		return 0;
+	intr_handle->intr_vec = (int *)
+		rte_malloc("intr_vec", rxqs_n * sizeof(int), 0);
+	if (intr_handle->intr_vec == NULL) {
+		WARN("Failed to allocate memory for intr_vec "
+		     "rxq interrupt will not be supported");
+		return -ENOMEM;
+	}
+	for (i = 0; i != rxqs_n; ++i) {
+		/* 1:1 mapping between rxq and interrupt. */
+		intr_handle->intr_vec[i] = RTE_INTR_VEC_RXTX_OFFSET + i;
+	}
+	return 0;
+}
+
+/**
+ * Destroy init interrupt vector array.
+ *
+ * @param priv
+ *   Private structure.
+ *
+ * @return
+ *   0 on success, negative on failure.
+ */
+void
+priv_destroy_intr_vec(struct priv *priv)
+{
+	struct rte_intr_handle *intr_handle = priv->dev->intr_handle;
+
+	rte_free(intr_handle->intr_vec);
+}
diff --git a/drivers/net/mlx5/mlx5_rxtx.c b/drivers/net/mlx5/mlx5_rxtx.c
index 2d33f2d..cf3abd3 100644
--- a/drivers/net/mlx5/mlx5_rxtx.c
+++ b/drivers/net/mlx5/mlx5_rxtx.c
@@ -1671,3 +1671,76 @@
 	(void)pkts_n;
 	return 0;
 }
+
+/**
+ * DPDK callback for rx queue interrupt enable.
+ *
+ * @param dev
+ *   Pointer to Ethernet device structure.
+ * @param rx_queue_id
+ *   RX queue number
+ *
+ * @return
+ *   0 on success, negative on failure.
+ */
+int
+mlx5_rx_intr_enable(struct rte_eth_dev *dev, uint16_t rx_queue_id)
+{
+#ifdef HAVE_UPDATE_CQ_CI
+	struct priv *priv = mlx5_get_priv(dev);
+	struct rxq *rxq = (*priv->rxqs)[rx_queue_id];
+	struct rxq_ctrl *rxq_ctrl = container_of(rxq, struct rxq_ctrl, rxq);
+	struct ibv_cq *cq = rxq_ctrl->cq;
+	uint16_t ci = rxq->cq_ci;
+	int ret = 0;
+
+	ibv_mlx5_exp_update_cq_ci(cq, ci);
+	ret = ibv_req_notify_cq(cq, 0);
+#else
+	int ret = -1;
+	(void)dev;
+	(void)rx_queue_id;
+#endif
+	if (ret)
+		WARN("unable to arm interrupt on rx queue %d", rx_queue_id);
+	return ret;
+}
+
+/**
+ * DPDK callback for rx queue interrupt disable.
+ *
+ * @param dev
+ *   Pointer to Ethernet device structure.
+ * @param rx_queue_id
+ *   RX queue number
+ *
+ * @return
+ *   0 on success, negative on failure.
+ */
+int
+mlx5_rx_intr_disable(struct rte_eth_dev *dev, uint16_t rx_queue_id)
+{
+#ifdef HAVE_UPDATE_CQ_CI
+	struct priv *priv = mlx5_get_priv(dev);
+	struct rxq *rxq = (*priv->rxqs)[rx_queue_id];
+	struct rxq_ctrl *rxq_ctrl = container_of(rxq, struct rxq_ctrl, rxq);
+	struct ibv_cq *cq = rxq_ctrl->cq;
+	struct ibv_cq *ev_cq;
+	void *ev_ctx;
+	int ret = 0;
+
+	ret = ibv_get_cq_event(cq->channel, &ev_cq, &ev_ctx);
+	if (ret || ev_cq != cq)
+		ret = -1;
+	else
+		ibv_ack_cq_events(cq, 1);
+#else
+	int ret = -1;
+	(void)dev;
+	(void)rx_queue_id;
+#endif
+	if (ret)
+		WARN("unable to disable interrupt on rx queue %d",
+		     rx_queue_id);
+	return ret;
+}
diff --git a/drivers/net/mlx5/mlx5_rxtx.h b/drivers/net/mlx5/mlx5_rxtx.h
index 9669564..0db810c 100644
--- a/drivers/net/mlx5/mlx5_rxtx.h
+++ b/drivers/net/mlx5/mlx5_rxtx.h
@@ -138,6 +138,7 @@ struct rxq_ctrl {
 	struct ibv_mr *mr; /* Memory Region (for mp). */
 	struct ibv_exp_wq_family *if_wq; /* WQ burst interface. */
 	struct ibv_exp_cq_family_v1 *if_cq; /* CQ interface. */
+	struct ibv_comp_channel *channel;
 	unsigned int socket; /* CPU socket ID for allocations. */
 	struct rxq rxq; /* Data path structure. */
 };
@@ -299,6 +300,10 @@ size_t priv_flow_attr(struct priv *, struct ibv_exp_flow_attr *,
 void priv_destroy_hash_rxqs(struct priv *);
 int priv_allow_flow_type(struct priv *, enum hash_rxq_flow_type);
 int priv_rehash_flows(struct priv *);
+int priv_intr_efd_enable(struct priv *priv);
+void priv_intr_efd_disable(struct priv *priv);
+int priv_create_intr_vec(struct priv *priv);
+void priv_destroy_intr_vec(struct priv *priv);
 void rxq_cleanup(struct rxq_ctrl *);
 int rxq_rehash(struct rte_eth_dev *, struct rxq_ctrl *);
 int rxq_ctrl_setup(struct rte_eth_dev *, struct rxq_ctrl *, uint16_t,
@@ -327,6 +332,8 @@ int mlx5_tx_queue_setup(struct rte_eth_dev *, uint16_t, uint16_t, unsigned int,
 uint16_t mlx5_rx_burst(void *, struct rte_mbuf **, uint16_t);
 uint16_t removed_tx_burst(void *, struct rte_mbuf **, uint16_t);
 uint16_t removed_rx_burst(void *, struct rte_mbuf **, uint16_t);
+int mlx5_rx_intr_enable(struct rte_eth_dev *dev, uint16_t rx_queue_id);
+int mlx5_rx_intr_disable(struct rte_eth_dev *dev, uint16_t rx_queue_id);
 
 /* mlx5_mr.c */
 
diff --git a/drivers/net/mlx5/mlx5_trigger.c b/drivers/net/mlx5/mlx5_trigger.c
index 0acbf28..229b05e 100644
--- a/drivers/net/mlx5/mlx5_trigger.c
+++ b/drivers/net/mlx5/mlx5_trigger.c
@@ -95,6 +95,11 @@
 		goto error;
 	}
 	priv_dev_interrupt_handler_install(priv, dev);
+	if (dev->data->dev_conf.intr_conf.rxq) {
+		err = priv_intr_efd_enable(priv);
+		if (!err)
+			err = priv_create_intr_vec(priv);
+	}
 	priv_xstats_init(priv);
 	priv_unlock(priv);
 	return 0;
@@ -135,6 +140,10 @@
 	priv_fdir_disable(priv);
 	priv_flow_stop(priv);
 	priv_dev_interrupt_handler_uninstall(priv, dev);
+	if (priv->dev->data->dev_conf.intr_conf.rxq) {
+		priv_destroy_intr_vec(priv);
+		priv_intr_efd_disable(priv);
+	}
 	priv->started = 0;
 	priv_unlock(priv);
 }
-- 
1.8.3.1