[PATCH v3 2/4] ethdev: add get restore flags driver callback

[Dariusz Sosnowski <dsosnowski@nvidia.com>]

Before this patch, ethdev layer assumed that all drivers require that
it has to forcefully restore:

- MAC addresses
- promiscuous mode setting
- all multicast mode setting

upon rte_eth_dev_start().

This patch introduces a new callback to eth_dev_ops -
get_restore_flags().
Drivers implementing this callback can explicitly enable/disable
certain parts of config restore procedure.

In order to minimize the changes to all the drivers and
preserve the current behavior, it is assumed that
if this callback is not defined, all configuration should be restored.

Signed-off-by: Dariusz Sosnowski <dsosnowski@nvidia.com>
---
 lib/ethdev/ethdev_driver.c |  9 ++++++
 lib/ethdev/ethdev_driver.h | 66 ++++++++++++++++++++++++++++++++++++++
 lib/ethdev/version.map     |  1 +
 3 files changed, 76 insertions(+)

diff --git a/lib/ethdev/ethdev_driver.c b/lib/ethdev/ethdev_driver.c
index c335a25a82..9afef06431 100644
--- a/lib/ethdev/ethdev_driver.c
+++ b/lib/ethdev/ethdev_driver.c
@@ -958,3 +958,12 @@ rte_eth_switch_domain_free(uint16_t domain_id)
 
 	return 0;
 }
+
+uint64_t
+rte_eth_get_restore_flags(struct rte_eth_dev *dev, enum rte_eth_dev_operation op)
+{
+	if (dev->dev_ops->get_restore_flags != NULL)
+		return dev->dev_ops->get_restore_flags(dev, op);
+	else
+		return RTE_ETH_RESTORE_ALL;
+}
diff --git a/lib/ethdev/ethdev_driver.h b/lib/ethdev/ethdev_driver.h
index ae00ead865..3974512a5c 100644
--- a/lib/ethdev/ethdev_driver.h
+++ b/lib/ethdev/ethdev_driver.h
@@ -1235,6 +1235,48 @@ typedef int (*eth_count_aggr_ports_t)(struct rte_eth_dev *dev);
 typedef int (*eth_map_aggr_tx_affinity_t)(struct rte_eth_dev *dev, uint16_t tx_queue_id,
 					  uint8_t affinity);
 
+/**
+ * @internal
+ * Defines types of operations which can be executed by the application.
+ */
+enum rte_eth_dev_operation {
+	RTE_ETH_START,
+};
+
+/**@{@name Restore flags
+ * Flags returned by get_restore_flags() callback.
+ * They indicate to ethdev layer which configuration is required to be restored.
+ */
+/** If set, ethdev layer will forcefully restore default and any other added MAC addresses. */
+#define RTE_ETH_RESTORE_MAC_ADDR RTE_BIT64(0)
+/** If set, ethdev layer will forcefully restore current promiscuous mode setting. */
+#define RTE_ETH_RESTORE_PROMISC  RTE_BIT64(1)
+/** If set, ethdev layer will forcefully restore current all multicast mode setting. */
+#define RTE_ETH_RESTORE_ALLMULTI RTE_BIT64(2)
+/**@}*/
+
+/** All configuration which can be restored by ethdev layer. */
+#define RTE_ETH_RESTORE_ALL (RTE_ETH_RESTORE_MAC_ADDR | \
+			     RTE_ETH_RESTORE_PROMISC | \
+			     RTE_ETH_RESTORE_ALLMULTI)
+
+/**
+ * @internal
+ * Fetch from the driver what kind of configuration must be restored by ethdev layer,
+ * after certain operations are performed by the application (such as rte_eth_dev_start()).
+ *
+ * @param dev
+ *   Port (ethdev) handle.
+ * @param op
+ *   Type of operation executed by the application.
+ *
+ * @return
+ *   ORed restore flags indicating which configuration should be restored by ethdev.
+ *   0 if no restore is required by the driver.
+ */
+typedef uint64_t (*eth_get_restore_flags_t)(struct rte_eth_dev *dev,
+					    enum rte_eth_dev_operation op);
+
 /**
  * @internal A structure containing the functions exported by an Ethernet driver.
  */
@@ -1474,6 +1516,9 @@ struct eth_dev_ops {
 	eth_count_aggr_ports_t count_aggr_ports;
 	/** Map a Tx queue with an aggregated port of the DPDK port */
 	eth_map_aggr_tx_affinity_t map_aggr_tx_affinity;
+
+	/** Get configuration which ethdev should restore */
+	eth_get_restore_flags_t get_restore_flags;
 };
 
 /**
@@ -2131,6 +2176,27 @@ struct rte_eth_fdir_conf {
 	struct rte_eth_fdir_flex_conf flex_conf;
 };
 
+/**
+ * @internal
+ * Fetch from the driver what kind of configuration must be restored by ethdev layer,
+ * using get_restore_flags() callback.
+ *
+ * If callback is not defined, it is assumed that all supported configuration must be restored.
+ *
+ * @param dev
+ *   Port (ethdev) handle.
+ * @param op
+ *   Type of operation executed by the application.
+ *
+ * @return
+ *   ORed restore flags indicating which configuration should be restored by ethdev.
+ *   0 if no restore is required by the driver.
+ */
+__rte_internal
+uint64_t
+rte_eth_get_restore_flags(struct rte_eth_dev *dev,
+			  enum rte_eth_dev_operation op);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/lib/ethdev/version.map b/lib/ethdev/version.map
index 1669055ca5..fa0469e602 100644
--- a/lib/ethdev/version.map
+++ b/lib/ethdev/version.map
@@ -358,4 +358,5 @@ INTERNAL {
 	rte_eth_switch_domain_alloc;
 	rte_eth_switch_domain_free;
 	rte_flow_fp_default_ops;
+	rte_eth_get_restore_flags;
 };
-- 
2.39.5