bus: introduce device plug/unplug

This allows the buses to plug and probe specific devices.
This is meant to be a building block for hotplug support.

Signed-off-by: Jan Blunck <jblunck@infradead.org>

diff --git a/lib/librte_eal/common/eal_common_bus.c b/lib/librte_eal/common/eal_common_bus.c
index bf2b138..87b0c6e 100644 (file)
--- a/lib/librte_eal/common/eal_common_bus.c
+++ b/lib/librte_eal/common/eal_common_bus.c
@@ -51,6 +51,8 @@ rte_bus_register(struct rte_bus *bus)
        RTE_VERIFY(bus->scan);
        RTE_VERIFY(bus->probe);
        RTE_VERIFY(bus->find_device);
+       /* Buses supporting driver plug also require unplug. */
+       RTE_VERIFY(!bus->plug || bus->unplug);
 
        TAILQ_INSERT_TAIL(&rte_bus_list, bus, next);
        RTE_LOG(DEBUG, EAL, "Registered [%s] bus.\n", bus->name);

diff --git a/lib/librte_eal/common/include/rte_bus.h b/lib/librte_eal/common/include/rte_bus.h
index 509292d..2f1c911 100644 (file)
--- a/lib/librte_eal/common/include/rte_bus.h
+++ b/lib/librte_eal/common/include/rte_bus.h
@@ -107,6 +107,36 @@ typedef struct rte_device *
 (*rte_bus_find_device_t)(const struct rte_device *start, rte_dev_cmp_t cmp,
                         const void *data);
 
+/**
+ * Implementation specific probe function which is responsible for linking
+ * devices on that bus with applicable drivers.
+ *
+ * @param dev
+ *     Device pointer that was returned by a previous call to find_device.
+ *
+ * @param devargs
+ *     Device declaration.
+ *
+ * @return
+ *     0 on success.
+ *     !0 on error.
+ */
+typedef int (*rte_bus_plug_t)(struct rte_device *dev,
+                             const char *devargs);
+
+/**
+ * Implementation specific remove function which is responsible for unlinking
+ * devices on that bus from assigned driver.
+ *
+ * @param dev
+ *     Device pointer that was returned by a previous call to find_device.
+ *
+ * @return
+ *     0 on success.
+ *     !0 on error.
+ */
+typedef int (*rte_bus_unplug_t)(struct rte_device *dev);
+
 /**
  * A structure describing a generic bus.
  */
@@ -116,6 +146,8 @@ struct rte_bus {
        rte_bus_scan_t scan;         /**< Scan for devices attached to bus */
        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 */
+       rte_bus_unplug_t unplug;     /**< Remove single device from driver */
 };
 
 /**