[dpdk-dev] [PATCH V3] ethdev: add dev configured flag

[Huisong Li]

Currently, if dev_configure is not called or fails to be called, users
can still call dev_start successfully. So it is necessary to have a flag
which indicates whether the device is configured, to control whether
dev_start can be called and eliminate dependency on user invocation order.

The flag stored in "struct rte_eth_dev_data" is more reasonable than
 "enum rte_eth_dev_state". "enum rte_eth_dev_state" is private to the
primary and secondary processes, and can be independently controlled.
However, the secondary process does not make resource allocations and
does not call dev_configure(). These are done by the primary process
and can be obtained or used by the secondary process. So this patch
adds a "dev_configured" flag in "rte_eth_dev_data", like "dev_started".

Signed-off-by: Huisong Li <lihuisong at huawei.com>
Reviewed-by: Andrew Rybchenko <andrew.rybchenko at oktetlabs.ru>
Acked-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
---
v2 -> v3:
 - move "dev->data->dev_configured = 1" to the front of the trace.
v1 -> v2:                                                                  
 - adjusting the description of patch.
---
 lib/ethdev/rte_ethdev.c      | 15 +++++++++++++++
 lib/ethdev/rte_ethdev_core.h |  6 +++++-
 2 files changed, 20 insertions(+), 1 deletion(-)

diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
index c607eab..6ebf52b 100644
--- a/lib/ethdev/rte_ethdev.c
+++ b/lib/ethdev/rte_ethdev.c
@@ -1356,6 +1356,13 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 		return -EBUSY;
 	}
 
+	/*
+	 * Ensure that "dev_configured" is always 0 each time prepare to do
+	 * dev_configure() to avoid any non-anticipated behaviour.
+	 * And set to 1 when dev_configure() is executed successfully.
+	 */
+	dev->data->dev_configured = 0;
+
 	 /* Store original config, as rollback required on failure */
 	memcpy(&orig_conf, &dev->data->dev_conf, sizeof(dev->data->dev_conf));
 
@@ -1605,6 +1612,7 @@ rte_eth_dev_configure(uint16_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 		goto reset_queues;
 	}
 
+	dev->data->dev_configured = 1;
 	rte_ethdev_trace_configure(port_id, nb_rx_q, nb_tx_q, dev_conf, 0);
 	return 0;
 reset_queues:
@@ -1751,6 +1759,13 @@ rte_eth_dev_start(uint16_t port_id)
 
 	RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->dev_start, -ENOTSUP);
 
+	if (dev->data->dev_configured == 0) {
+		RTE_ETHDEV_LOG(INFO,
+			"Device with port_id=%"PRIu16" is not configured.\n",
+			port_id);
+		return -EINVAL;
+	}
+
 	if (dev->data->dev_started != 0) {
 		RTE_ETHDEV_LOG(INFO,
 			"Device with port_id=%"PRIu16" already started\n",
diff --git a/lib/ethdev/rte_ethdev_core.h b/lib/ethdev/rte_ethdev_core.h
index 4679d94..edf96de 100644
--- a/lib/ethdev/rte_ethdev_core.h
+++ b/lib/ethdev/rte_ethdev_core.h
@@ -167,7 +167,11 @@ struct rte_eth_dev_data {
 		scattered_rx : 1,  /**< RX of scattered packets is ON(1) / OFF(0) */
 		all_multicast : 1, /**< RX all multicast mode ON(1) / OFF(0). */
 		dev_started : 1,   /**< Device state: STARTED(1) / STOPPED(0). */
-		lro         : 1;   /**< RX LRO is ON(1) / OFF(0) */
+		lro         : 1,   /**< RX LRO is ON(1) / OFF(0) */
+		dev_configured : 1;
+		/**< Indicates whether the device is configured.
+		 *   CONFIGURED(1) / NOT CONFIGURED(0).
+		 */
 	uint8_t rx_queue_state[RTE_MAX_QUEUES_PER_PORT];
 		/**< Queues state: HAIRPIN(2) / STARTED(1) / STOPPED(0). */
 	uint8_t tx_queue_state[RTE_MAX_QUEUES_PER_PORT];
-- 
2.7.4