[dpdk-dev] [PATCH v3] ethdev: get rxq interrupt fd

[Xiaoyun Li <xiaoyun.li@intel.com>]

Some users want to use their own epoll instances to control both
DPDK rxq interrupt fds and their own other fds. So added a function
to get rxq interrupt fd based on port id and queue id.

Signed-off-by: Xiaoyun Li <xiaoyun.li@intel.com>
---
v3:
 * Since the API only wants to return fd, return fd or -1.
v2:
 * Added missing API doxygen comments.
 * Set the new API to be experimental and added it in .map file.
---
 lib/librte_ethdev/rte_ethdev.c           | 37 ++++++++++++++++++++++++
 lib/librte_ethdev/rte_ethdev.h           | 20 +++++++++++++
 lib/librte_ethdev/rte_ethdev_version.map |  1 +
 3 files changed, 58 insertions(+)

diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index ef99f7068..4930eb6ff 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -3433,6 +3433,43 @@ rte_eth_dev_rx_intr_ctl(uint16_t port_id, int epfd, int op, void *data)
 	return 0;
 }
 
+int __rte_experimental
+rte_eth_dev_rx_intr_ctl_q_get_fd(uint16_t port_id, uint16_t queue_id)
+{
+	struct rte_intr_handle *intr_handle;
+	struct rte_eth_dev *dev;
+	unsigned int efd_idx;
+	uint32_t vec;
+	int fd;
+
+	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -1);
+
+	dev = &rte_eth_devices[port_id];
+
+	if (queue_id >= dev->data->nb_rx_queues) {
+		RTE_ETHDEV_LOG(ERR, "Invalid RX queue_id=%u\n", queue_id);
+		return -1;
+	}
+
+	if (!dev->intr_handle) {
+		RTE_ETHDEV_LOG(ERR, "RX Intr handle unset\n");
+		return -1;
+	}
+
+	intr_handle = dev->intr_handle;
+	if (!intr_handle->intr_vec) {
+		RTE_ETHDEV_LOG(ERR, "RX Intr vector unset\n");
+		return -1;
+	}
+
+	vec = intr_handle->intr_vec[queue_id];
+	efd_idx = (vec >= RTE_INTR_VEC_RXTX_OFFSET) ?
+		(vec - RTE_INTR_VEC_RXTX_OFFSET) : vec;
+	fd = intr_handle->efds[efd_idx];
+
+	return fd;
+}
+
 const struct rte_memzone *
 rte_eth_dma_zone_reserve(const struct rte_eth_dev *dev, const char *ring_name,
 			 uint16_t queue_id, size_t size, unsigned align,
diff --git a/lib/librte_ethdev/rte_ethdev.h b/lib/librte_ethdev/rte_ethdev.h
index 012577b0a..f9366f3f0 100644
--- a/lib/librte_ethdev/rte_ethdev.h
+++ b/lib/librte_ethdev/rte_ethdev.h
@@ -2719,6 +2719,26 @@ int rte_eth_dev_rx_intr_ctl(uint16_t port_id, int epfd, int op, void *data);
 int rte_eth_dev_rx_intr_ctl_q(uint16_t port_id, uint16_t queue_id,
 			      int epfd, int op, void *data);
 
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Get interrupt fd per Rx queue.
+ *
+ * @param port_id
+ *   The port identifier of the Ethernet device.
+ * @param queue_id
+ *   The index of the receive queue from which to retrieve input packets.
+ *   The value must be in the range [0, nb_rx_queue - 1] previously supplied
+ *   to rte_eth_dev_configure().
+ * @return
+ *   - (>=0) the interrupt fd associated to the requested Rx queue if
+ *           successful.
+ *   - (-1) on error.
+ */
+int __rte_experimental
+rte_eth_dev_rx_intr_ctl_q_get_fd(uint16_t port_id, uint16_t queue_id);
+
 /**
  * Turn on the LED on the Ethernet device.
  * This function turns on the LED on the Ethernet device.
diff --git a/lib/librte_ethdev/rte_ethdev_version.map b/lib/librte_ethdev/rte_ethdev_version.map
index 38f117f01..c98f9fa4a 100644
--- a/lib/librte_ethdev/rte_ethdev_version.map
+++ b/lib/librte_ethdev/rte_ethdev_version.map
@@ -235,6 +235,7 @@ EXPERIMENTAL {
 	rte_eth_dev_owner_new;
 	rte_eth_dev_owner_set;
 	rte_eth_dev_owner_unset;
+	rte_eth_dev_rx_intr_ctl_q_get_fd;
 	rte_eth_dev_rx_offload_name;
 	rte_eth_dev_tx_offload_name;
 	rte_eth_switch_domain_alloc;
-- 
2.17.1