[PATCH v5 3/7] ethdev: introduce Rx queue based available descriptor threshold

[Spike Du <spiked@nvidia.com>]

available descriptor threshold describes the availability of a Rx queue
for hardware.
If the availability is below the threshold, the device will trigger the
event RTE_ETH_EVENT_RX_AVAIL_THRESH.
available descriptor threshold is defined as a percentage of Rx queue
size with valid value of [0,99].
Setting available descriptor threshold to 0 means disable it, which is
the default.
Add available descriptor threshold configuration and query driver
callbacks in eth_dev_ops.
Add command line options to support avail_thresh per-rxq configure.
- Command syntax:
  set port <port_id> rxq <rxq_id> avail_thresh <avail_thresh_num>

- Example commands:
To configure avail_thresh as 30% of rxq size on port 1 rxq 0:
testpmd> set port 1 rxq 0 avail_thresh 30

To disable avail_thresh on port 1 rxq 0:
testpmd> set port 1 rxq 0 avail_thresh 0

Signed-off-by: Spike Du <spiked@nvidia.com>
---
 app/test-pmd/cmdline.c     | 68 ++++++++++++++++++++++++++++++++++++++++++
 app/test-pmd/config.c      | 20 +++++++++++++
 app/test-pmd/testpmd.c     | 14 +++++++++
 app/test-pmd/testpmd.h     |  2 ++
 lib/ethdev/ethdev_driver.h | 22 ++++++++++++++
 lib/ethdev/rte_ethdev.c    | 44 ++++++++++++++++++++++++++++
 lib/ethdev/rte_ethdev.h    | 73 ++++++++++++++++++++++++++++++++++++++++++++++
 lib/ethdev/version.map     |  2 ++
 8 files changed, 245 insertions(+)

diff --git a/app/test-pmd/cmdline.c b/app/test-pmd/cmdline.c
index 0410bad..bbf5835 100644
--- a/app/test-pmd/cmdline.c
+++ b/app/test-pmd/cmdline.c
@@ -17823,6 +17823,73 @@ struct cmd_show_port_flow_transfer_proxy_result {
 	}
 };
 
+/* *** SET AVAIL THRESHOLD FOR A RXQ OF A PORT *** */
+struct cmd_rxq_avail_thresh_result {
+	cmdline_fixed_string_t set;
+	cmdline_fixed_string_t port;
+	uint16_t port_num;
+	cmdline_fixed_string_t rxq;
+	uint16_t rxq_num;
+	cmdline_fixed_string_t avail_thresh;
+	uint8_t avail_thresh_num;
+};
+
+static void cmd_rxq_avail_thresh_parsed(void *parsed_result,
+		__rte_unused struct cmdline *cl,
+		__rte_unused void *data)
+{
+	struct cmd_rxq_avail_thresh_result *res = parsed_result;
+	int ret = 0;
+
+	if ((strcmp(res->set, "set") == 0) && (strcmp(res->port, "port") == 0)
+	    && (strcmp(res->rxq, "rxq") == 0)
+	    && (strcmp(res->avail_thresh, "avail_thresh") == 0))
+		ret = set_rxq_avail_thresh(res->port_num, res->rxq_num,
+				  res->avail_thresh_num);
+	if (ret < 0)
+		printf("rxq_avail_thresh_cmd error: (%s)\n", strerror(-ret));
+
+}
+
+static cmdline_parse_token_string_t cmd_rxq_avail_thresh_set =
+	TOKEN_STRING_INITIALIZER(struct cmd_rxq_avail_thresh_result,
+				set, "set");
+static cmdline_parse_token_string_t cmd_rxq_avail_thresh_port =
+	TOKEN_STRING_INITIALIZER(struct cmd_rxq_avail_thresh_result,
+				port, "port");
+static cmdline_parse_token_num_t cmd_rxq_avail_thresh_portnum =
+	TOKEN_NUM_INITIALIZER(struct cmd_rxq_avail_thresh_result,
+				port_num, RTE_UINT16);
+static cmdline_parse_token_string_t cmd_rxq_avail_thresh_rxq =
+	TOKEN_STRING_INITIALIZER(struct cmd_rxq_avail_thresh_result,
+				rxq, "rxq");
+static cmdline_parse_token_num_t cmd_rxq_avail_thresh_rxqnum =
+	TOKEN_NUM_INITIALIZER(struct cmd_rxq_avail_thresh_result,
+				rxq_num, RTE_UINT16);
+static cmdline_parse_token_string_t cmd_rxq_avail_thresh_avail_thresh =
+	TOKEN_STRING_INITIALIZER(struct cmd_rxq_avail_thresh_result,
+				avail_thresh, "avail_thresh");
+static cmdline_parse_token_num_t cmd_rxq_avail_thresh_avail_threshnum =
+	TOKEN_NUM_INITIALIZER(struct cmd_rxq_avail_thresh_result,
+				avail_thresh_num, RTE_UINT8);
+
+static cmdline_parse_inst_t cmd_rxq_avail_thresh = {
+	.f = cmd_rxq_avail_thresh_parsed,
+	.data = (void *)0,
+	.help_str = "set port <port_id> rxq <rxq_id> avail_thresh <avail_thresh_num>"
+		"Set avail_thresh for rxq on port_id",
+	.tokens = {
+		(void *)&cmd_rxq_avail_thresh_set,
+		(void *)&cmd_rxq_avail_thresh_port,
+		(void *)&cmd_rxq_avail_thresh_portnum,
+		(void *)&cmd_rxq_avail_thresh_rxq,
+		(void *)&cmd_rxq_avail_thresh_rxqnum,
+		(void *)&cmd_rxq_avail_thresh_avail_thresh,
+		(void *)&cmd_rxq_avail_thresh_avail_threshnum,
+		NULL,
+	},
+};
+
 /* ******************************************************************************** */
 
 /* list of instructions */
@@ -18110,6 +18177,7 @@ struct cmd_show_port_flow_transfer_proxy_result {
 	(cmdline_parse_inst_t *)&cmd_show_capability,
 	(cmdline_parse_inst_t *)&cmd_set_flex_is_pattern,
 	(cmdline_parse_inst_t *)&cmd_set_flex_spec_pattern,
+	(cmdline_parse_inst_t *)&cmd_rxq_avail_thresh,
 	NULL,
 };
 
diff --git a/app/test-pmd/config.c b/app/test-pmd/config.c
index 1b1e738..b754091 100644
--- a/app/test-pmd/config.c
+++ b/app/test-pmd/config.c
@@ -6342,3 +6342,23 @@ struct igb_ring_desc_16_bytes {
 		printf("  %s\n", buf);
 	}
 }
+
+int
+set_rxq_avail_thresh(portid_t port_id, uint16_t queue_id, uint8_t avail_thresh)
+{
+	struct rte_eth_link link;
+	int ret;
+
+	if (port_id_is_invalid(port_id, ENABLED_WARN))
+		return -EINVAL;
+	ret = eth_link_get_nowait_print_err(port_id, &link);
+	if (ret < 0)
+		return -EINVAL;
+	if (avail_thresh > 99)
+		return -EINVAL;
+	ret = rte_eth_rx_avail_thresh_set(port_id, queue_id, avail_thresh);
+	if (ret != 0)
+		return ret;
+	return 0;
+}
+
diff --git a/app/test-pmd/testpmd.c b/app/test-pmd/testpmd.c
index 767765d..33d9b85 100644
--- a/app/test-pmd/testpmd.c
+++ b/app/test-pmd/testpmd.c
@@ -420,6 +420,7 @@ struct fwd_engine * fwd_engines[] = {
 	[RTE_ETH_EVENT_NEW] = "device probed",
 	[RTE_ETH_EVENT_DESTROY] = "device released",
 	[RTE_ETH_EVENT_FLOW_AGED] = "flow aged",
+	[RTE_ETH_EVENT_RX_AVAIL_THRESH] = "rxq available threshold reached",
 	[RTE_ETH_EVENT_MAX] = NULL,
 };
 
@@ -3616,6 +3617,9 @@ struct pmd_test_command {
 eth_event_callback(portid_t port_id, enum rte_eth_event_type type, void *param,
 		  void *ret_param)
 {
+	uint16_t rxq_id;
+	uint8_t avail_thresh;
+	int ret;
 	RTE_SET_USED(param);
 	RTE_SET_USED(ret_param);
 
@@ -3647,6 +3651,16 @@ struct pmd_test_command {
 		ports[port_id].port_status = RTE_PORT_CLOSED;
 		printf("Port %u is closed\n", port_id);
 		break;
+	case RTE_ETH_EVENT_RX_AVAIL_THRESH:
+		/* avail_thresh query API rewinds rxq_id, no need to check max rxq num. */
+		for (rxq_id = 0; ; rxq_id++) {
+			ret = rte_eth_rx_avail_thresh_query(port_id, &rxq_id, &avail_thresh);
+			if (ret <= 0)
+				break;
+			printf("Received avail_thresh event, port:%d rxq_id:%d\n",
+			       port_id, rxq_id);
+		}
+		break;
 	default:
 		break;
 	}
diff --git a/app/test-pmd/testpmd.h b/app/test-pmd/testpmd.h
index 78a5f4e..5b268f4 100644
--- a/app/test-pmd/testpmd.h
+++ b/app/test-pmd/testpmd.h
@@ -1173,6 +1173,8 @@ uint16_t tx_pkt_set_dynf(uint16_t port_id, __rte_unused uint16_t queue,
 void flex_item_create(portid_t port_id, uint16_t flex_id, const char *filename);
 void flex_item_destroy(portid_t port_id, uint16_t flex_id);
 void port_flex_item_flush(portid_t port_id);
+int set_rxq_avail_thresh(portid_t port_id, uint16_t queue_id,
+			 uint8_t avail_thresh);
 
 extern int flow_parse(const char *src, void *result, unsigned int size,
 		      struct rte_flow_attr **attr,
diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h
index 69d9dc2..847f86a 100644
--- a/lib/ethdev/ethdev_driver.h
+++ b/lib/ethdev/ethdev_driver.h
@@ -1074,6 +1074,23 @@ typedef int (*eth_ip_reassembly_conf_set_t)(struct rte_eth_dev *dev,
 typedef int (*eth_dev_priv_dump_t)(struct rte_eth_dev *dev, FILE *file);
 
 /**
+ * @internal Set Rx queue available descriptor threshold.
+ * @see rte_eth_rx_avail_thresh_set()
+ */
+typedef int (*eth_rx_queue_avail_thresh_set_t)(struct rte_eth_dev *dev,
+				      uint16_t rx_queue_id,
+				      uint8_t avail_thresh);
+
+/**
+ * @internal Query queue available descriptor threshold event.
+ * @see rte_eth_rx_avail_thresh_query()
+ */
+
+typedef int (*eth_rx_queue_avail_thresh_query_t)(struct rte_eth_dev *dev,
+					uint16_t *rx_queue_id,
+					uint8_t *avail_thresh);
+
+/**
  * @internal A structure containing the functions exported by an Ethernet driver.
  */
 struct eth_dev_ops {
@@ -1283,6 +1300,11 @@ struct eth_dev_ops {
 
 	/** Dump private info from device */
 	eth_dev_priv_dump_t eth_dev_priv_dump;
+
+	/** Set Rx queue available descriptor threshold. */
+	eth_rx_queue_avail_thresh_set_t rx_queue_avail_thresh_set;
+	/** Query Rx queue available descriptor threshold event. */
+	eth_rx_queue_avail_thresh_query_t rx_queue_avail_thresh_query;
 };
 
 /**
diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
index a175867..92fb282 100644
--- a/lib/ethdev/rte_ethdev.c
+++ b/lib/ethdev/rte_ethdev.c
@@ -4424,6 +4424,50 @@ int rte_eth_set_queue_rate_limit(uint16_t port_id, uint16_t queue_idx,
 							queue_idx, tx_rate));
 }
 
+int rte_eth_rx_avail_thresh_set(uint16_t port_id, uint16_t queue_id,
+			       uint8_t avail_thresh)
+{
+	struct rte_eth_dev *dev;
+
+	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
+	dev = &rte_eth_devices[port_id];
+
+	if (queue_id > dev->data->nb_rx_queues) {
+		RTE_ETHDEV_LOG(ERR,
+			"Set queue avail thresh: port %u: invalid queue ID=%u.\n",
+			port_id, queue_id);
+		return -EINVAL;
+	}
+
+	if (avail_thresh > 99) {
+		RTE_ETHDEV_LOG(ERR,
+			"Set queue avail thresh: port %u: threshold should be <= 99.\n",
+			port_id);
+		return -EINVAL;
+	}
+	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->rx_queue_avail_thresh_set, -ENOTSUP);
+	return eth_err(port_id, (*dev->dev_ops->rx_queue_avail_thresh_set)(dev,
+							     queue_id, avail_thresh));
+}
+
+int rte_eth_rx_avail_thresh_query(uint16_t port_id, uint16_t *queue_id,
+				 uint8_t *avail_thresh)
+{
+	struct rte_eth_dev *dev;
+
+	RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV);
+	dev = &rte_eth_devices[port_id];
+
+	if (queue_id == NULL)
+		return -EINVAL;
+	if (*queue_id >= dev->data->nb_rx_queues)
+		*queue_id = 0;
+
+	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->rx_queue_avail_thresh_query, -ENOTSUP);
+	return eth_err(port_id, (*dev->dev_ops->rx_queue_avail_thresh_query)(dev,
+							     queue_id, avail_thresh));
+}
+
 RTE_INIT(eth_dev_init_fp_ops)
 {
 	uint32_t i;
diff --git a/lib/ethdev/rte_ethdev.h b/lib/ethdev/rte_ethdev.h
index 04225bb..d01bfe4 100644
--- a/lib/ethdev/rte_ethdev.h
+++ b/lib/ethdev/rte_ethdev.h
@@ -1931,6 +1931,14 @@ struct rte_eth_rxq_info {
 	uint8_t queue_state;        /**< one of RTE_ETH_QUEUE_STATE_*. */
 	uint16_t nb_desc;           /**< configured number of RXDs. */
 	uint16_t rx_buf_size;       /**< hardware receive buffer size. */
+	/**
+	 * Per-queue Rx available descriptor threshold defined as percentage
+	 * of Rx queue size. If Rx queue available descriptor is lower than
+	 * this percentage, the event RTE_ETH_EVENT_RX_AVAIL_THESH is triggered.
+	 * Value 0 means threshold monitoring is disabled, no event is
+	 * triggered.
+	 */
+	uint8_t avail_thresh;
 } __rte_cache_min_aligned;
 
 /**
@@ -3672,6 +3680,66 @@ int rte_eth_dev_set_vlan_ether_type(uint16_t port_id,
  */
 int rte_eth_dev_set_vlan_pvid(uint16_t port_id, uint16_t pvid, int on);
 
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Set Rx queue based available descriptor threshold.
+ *
+ * @param port_id
+ *  The port identifier of the Ethernet device.
+ * @param queue_id
+ *  The index of the receive queue.
+ * @param avail_thresh
+ *  The available descriptor threshold is percentage of Rx queue size which
+ *  describes the availability of Rx queue for hardware. If the Rx queue
+ *  availability is below it, the device will trigger the event
+ *  RTE_ETH_EVENT_RX_AVAIL_THRESH.
+ *  [1-99] to set a new available descriptor threshold.
+ *  0 to disable thresold monitoring.
+ *
+ * @return
+ *   - 0 if successful.
+ *   - negative if failed.
+ */
+__rte_experimental
+int rte_eth_rx_avail_thresh_set(uint16_t port_id, uint16_t queue_id,
+			       uint8_t avail_thresh);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Query Rx queue based available descriptor threshold event.
+ * The function queries all queues in the port circularly until one
+ * pending avail_thresh event is found or no pending avail_thresh event is found.
+ *
+ * @param port_id
+ *  The port identifier of the Ethernet device.
+ * @param queue_id
+ *  The API caller sets the starting Rx queue id in the pointer.
+ *  If the queue_id is bigger than maximum queue id of the port,
+ *  it's rewinded to 0 so that application can keep calling
+ *  this function to handle all pending avail_thresh events in the queues
+ *  with a simple increment between calls.
+ *  If a Rx queue has pending avail_thresh event, the pointer is updated
+ *  with this Rx queue id; otherwise this pointer's content is
+ *  unchanged.
+ * @param avail_thresh
+ *  The pointer to the available descriptor threshold percentage of Rx queue.
+ *  If Rx queue with pending avail_thresh event is found, the queue's avail_thresh
+ *  percentage is stored in this pointer, otherwise the pointer's
+ *  content is unchanged.
+ *
+ * @return
+ *   - 1 if a Rx queue with pending avail_thresh event is found.
+ *   - 0 if no Rx queue with pending avail_thresh event is found.
+ *   - -EINVAL if queue_id is NULL.
+ */
+__rte_experimental
+int rte_eth_rx_avail_thresh_query(uint16_t port_id, uint16_t *queue_id,
+				 uint8_t *avail_thresh);
+
 typedef void (*buffer_tx_error_fn)(struct rte_mbuf **unsent, uint16_t count,
 		void *userdata);
 
@@ -3877,6 +3945,11 @@ enum rte_eth_event_type {
 	RTE_ETH_EVENT_DESTROY,  /**< port is released */
 	RTE_ETH_EVENT_IPSEC,    /**< IPsec offload related event */
 	RTE_ETH_EVENT_FLOW_AGED,/**< New aged-out flows is detected */
+	/**
+	 *  Available threshold value is exceeded in a queue.
+	 *  @see rte_eth_rx_avail_thresh_set()
+	 */
+	RTE_ETH_EVENT_RX_AVAIL_THRESH,
 	RTE_ETH_EVENT_MAX       /**< max value of this enum */
 };
 
diff --git a/lib/ethdev/version.map b/lib/ethdev/version.map
index daca785..2fd928f 100644
--- a/lib/ethdev/version.map
+++ b/lib/ethdev/version.map
@@ -285,6 +285,8 @@ EXPERIMENTAL {
 	rte_mtr_color_in_protocol_priority_get;
 	rte_mtr_color_in_protocol_set;
 	rte_mtr_meter_vlan_table_update;
+	rte_eth_rx_avail_thresh_set;
+	rte_eth_rx_avail_thresh_query;
 };
 
 INTERNAL {
-- 
1.8.3.1