[dpdk-dev] [PATCH v4 1/4] ethdev: Add API to enable device event handler

[Jeff Guo <jia.guo@intel.com>]

Implement a couple of eal device event handler install/uninstall APIs
in ethdev, it could let PMDs have chance to manage the eal device event,
such as register device event callback, then monitor and process the
hotplug event.

Signed-off-by: Jeff Guo <jia.guo@intel.com>
---
v4->v3:
change to use eal device event handler install api
---
 doc/guides/rel_notes/release_18_08.rst | 12 +++++++
 lib/librte_ethdev/rte_ethdev.c         | 59 ++++++++++++++++++++++++++++++++++
 lib/librte_ethdev/rte_ethdev_driver.h  | 32 ++++++++++++++++++
 3 files changed, 103 insertions(+)

diff --git a/doc/guides/rel_notes/release_18_08.rst b/doc/guides/rel_notes/release_18_08.rst
index bc01242..b6482ce 100644
--- a/doc/guides/rel_notes/release_18_08.rst
+++ b/doc/guides/rel_notes/release_18_08.rst
@@ -46,6 +46,18 @@ New Features
   Flow API support has been added to CXGBE Poll Mode Driver to offload
   flows to Chelsio T5/T6 NICs.
 
+* **Added eal device event process helper in ethdev.**
+
+  Implement a couple of eal device event handler install/uninstall APIs in
+  ethdev, these helper could let PMDs have chance to manage the eal device
+  event, such as register device event callback, then monitor and process
+  hotplug event.
+
+  * ``rte_eth_dev_event_handler_install`` for PMDs use to install the device
+    event handler.
+  * ``rte_eth_dev_event_handler_uninstall`` for PMDs use to uninstall the device
+    event handler.
+
 
 API Changes
 -----------
diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c
index a9977df..09ea02d 100644
--- a/lib/librte_ethdev/rte_ethdev.c
+++ b/lib/librte_ethdev/rte_ethdev.c
@@ -4518,6 +4518,65 @@ rte_eth_devargs_parse(const char *dargs, struct rte_eth_devargs *eth_da)
 	return result;
 }
 
+static void __rte_experimental
+eth_dev_event_callback(char *device_name, enum rte_dev_event_type type,
+			     void *arg)
+{
+	struct rte_eth_dev *eth_dev = (struct rte_eth_dev *)arg;
+
+	switch (type) {
+	case RTE_DEV_EVENT_REMOVE:
+		ethdev_log(INFO, "The device: %s has been removed!\n",
+			    device_name);
+
+		if (!device_name || !eth_dev)
+			return;
+
+		if (!(eth_dev->data->dev_flags & RTE_ETH_EVENT_INTR_RMV))
+			return;
+
+		if (!strcmp(device_name, eth_dev->device->name))
+			_rte_eth_dev_callback_process(eth_dev,
+						      RTE_ETH_EVENT_INTR_RMV,
+						      NULL);
+		break;
+	case RTE_DEV_EVENT_ADD:
+		ethdev_log(INFO, "The device: %s has been added!\n",
+			device_name);
+		break;
+	default:
+		break;
+	}
+}
+
+int __rte_experimental
+rte_eth_dev_event_handler_install(struct rte_eth_dev *eth_dev)
+{
+	int result = 0;
+
+	result = rte_dev_event_callback_register(eth_dev->device->name,
+					eth_dev_event_callback, eth_dev);
+	if (result)
+		RTE_LOG(ERR, EAL, "device event callback register failed for "
+			"device:%s!\n", eth_dev->device->name);
+
+	return result;
+}
+
+int __rte_experimental
+rte_eth_dev_event_handler_uninstall(struct rte_eth_dev *eth_dev)
+{
+	int result = 0;
+
+	result = rte_dev_event_callback_unregister(eth_dev->device->name,
+					eth_dev_event_callback, eth_dev);
+	if (result)
+		RTE_LOG(ERR, EAL, "device event callback unregister failed for"
+			" device:%s!\n", eth_dev->device->name);
+
+	return result;
+}
+
 RTE_INIT(ethdev_init_log);
 static void
 ethdev_init_log(void)
diff --git a/lib/librte_ethdev/rte_ethdev_driver.h b/lib/librte_ethdev/rte_ethdev_driver.h
index c9c825e..3de1cd4 100644
--- a/lib/librte_ethdev/rte_ethdev_driver.h
+++ b/lib/librte_ethdev/rte_ethdev_driver.h
@@ -82,6 +82,38 @@ int rte_eth_dev_release_port(struct rte_eth_dev *eth_dev);
 void _rte_eth_dev_reset(struct rte_eth_dev *dev);
 
 /**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Implement a helper to install the device event handler for the specific
+ * ether device.
+ *
+ * @param dev
+ *  Pointer to struct rte_eth_dev.
+ *
+ * @return
+ *   - 0 on success, negative on error
+ */
+int __rte_experimental
+rte_eth_dev_event_handler_install(struct rte_eth_dev *dev);
+
+/**
+ * @warning
+ * @b EXPERIMENTAL: this API may change without prior notice.
+ *
+ * Implement a helper to uninstall the device event handler for the specific
+ * ether device.
+ *
+ * @param dev
+ *  Pointer to struct rte_eth_dev.
+ *
+ * @return
+ *   - 0 on success, negative on error
+ */
+int __rte_experimental
+rte_eth_dev_event_handler_uninstall(struct rte_eth_dev *dev);
+
+/**
  * @internal Executes all the user application registered callbacks for
  * the specific device. It is for DPDK internal user only. User
  * application should not call it directly.
-- 
2.7.4