[dpdk-dev] [PATCH v3 01/23] eal: introduce one device scan

Qi Zhang qi.z.zhang at intel.com
Mon Jun 25 09:17:23 CEST 2018


When hot plug a new device, it is not necessary to scan everything
on the bus since the devname and devargs are already there. So new
rte_bus ops "scan_one" is introduced, bus driver can implement this
function to simplify the hotplug process.

Signed-off-by: Qi Zhang <qi.z.zhang at intel.com>
---
 lib/librte_eal/common/eal_common_dev.c  | 17 +++++++++++++----
 lib/librte_eal/common/include/rte_bus.h | 16 ++++++++++++++++
 2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/lib/librte_eal/common/eal_common_dev.c b/lib/librte_eal/common/eal_common_dev.c
index 61cb3b162..1ad033536 100644
--- a/lib/librte_eal/common/eal_common_dev.c
+++ b/lib/librte_eal/common/eal_common_dev.c
@@ -147,11 +147,20 @@ int __rte_experimental rte_eal_hotplug_add(const char *busname, const char *devn
 	if (ret)
 		goto err_devarg;
 
-	ret = bus->scan();
-	if (ret)
-		goto err_devarg;
+	/**
+	 * if bus support to scan specific device by devargs,
+	 * we don't need to scan all devices on the bus.
+	 */
+	if (bus->scan_one) {
+		dev = bus->scan_one(da);
+	} else {
+		ret = bus->scan();
+		if (ret)
+			goto err_devarg;
+
+		dev = bus->find_device(NULL, cmp_detached_dev_name, devname);
+	}
 
-	dev = bus->find_device(NULL, cmp_detached_dev_name, devname);
 	if (dev == NULL) {
 		RTE_LOG(ERR, EAL, "Cannot find unplugged device (%s)\n",
 			devname);
diff --git a/lib/librte_eal/common/include/rte_bus.h b/lib/librte_eal/common/include/rte_bus.h
index eb9eded4e..3269ef78b 100644
--- a/lib/librte_eal/common/include/rte_bus.h
+++ b/lib/librte_eal/common/include/rte_bus.h
@@ -84,6 +84,21 @@ enum rte_iova_mode {
 typedef int (*rte_bus_scan_t)(void);
 
 /**
+ * Bus specific scan for one specific device attached on the bus.
+ * For each bus object, the scan would be responsible for finding the specific
+ * device and adding it to its private device list, and the device object will
+ * be return also.
+ *
+ * @param devargs
+ *	Device arguments be used to identify the device.
+ *
+ * @return
+ *	!NULL for successful scan
+ *	NULL for unsuccessful scan
+ */
+typedef struct rte_device *(*rte_bus_scan_one_t)(struct rte_devargs *devargs);
+
+/**
  * Implementation specific probe function which is responsible for linking
  * devices on that bus with applicable drivers.
  *
@@ -204,6 +219,7 @@ struct rte_bus {
 	TAILQ_ENTRY(rte_bus) next;   /**< Next bus object in linked list */
 	const char *name;            /**< Name of the bus */
 	rte_bus_scan_t scan;         /**< Scan for devices attached to bus */
+	rte_bus_scan_one_t scan_one; /**< Scan one device using devargs */
 	rte_bus_probe_t probe;       /**< Probe devices on bus */
 	rte_bus_find_device_t find_device; /**< Find a device on the bus */
 	rte_bus_plug_t plug;         /**< Probe single device for drivers */
-- 
2.13.6



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