down_read(&lists_rwsem);
device = __ib_device_get_by_index(index);
if (device) {
- /* Do not return a device if unregistration has started. */
- if (!refcount_inc_not_zero(&device->refcount))
+ if (!ib_device_try_get(device))
device = NULL;
}
up_read(&lists_rwsem);
return device;
}
+/**
+ * ib_device_put - Release IB device reference
+ * @device: device whose reference to be released
+ *
+ * ib_device_put() releases reference to the IB device to allow it to be
+ * unregistered and eventually free.
+ */
void ib_device_put(struct ib_device *device)
{
if (refcount_dec_and_test(&device->refcount))
complete(&device->unreg_completion);
}
+EXPORT_SYMBOL(ib_device_put);
static struct ib_device *__ib_device_get_by_name(const char *name)
{
rwlock_init(&device->client_data_lock);
INIT_LIST_HEAD(&device->client_data_list);
INIT_LIST_HEAD(&device->port_list);
- refcount_set(&device->refcount, 1);
init_completion(&device->unreg_completion);
return device;
goto cg_cleanup;
}
+ refcount_set(&device->refcount, 1);
device->reg_state = IB_DEV_REGISTERED;
list_for_each_entry(client, &client_list, list)
const struct uapi_definition *driver_def;
enum rdma_driver_id driver_id;
+
/*
- * Provides synchronization between device unregistration and netlink
- * commands on a device. To be used only by core.
+ * Positive refcount indicates that the device is currently
+ * registered and cannot be unregistered.
*/
refcount_t refcount;
struct completion unreg_completion;
int ib_check_mr_status(struct ib_mr *mr, u32 check_mask,
struct ib_mr_status *mr_status);
+/**
+ * ib_device_try_get: Hold a registration lock
+ * device: The device to lock
+ *
+ * A device under an active registration lock cannot become unregistered. It
+ * is only possible to obtain a registration lock on a device that is fully
+ * registered, otherwise this function returns false.
+ *
+ * The registration lock is only necessary for actions which require the
+ * device to still be registered. Uses that only require the device pointer to
+ * be valid should use get_device(&ibdev->dev) to hold the memory.
+ *
+ */
+static inline bool ib_device_try_get(struct ib_device *dev)
+{
+ return refcount_inc_not_zero(&dev->refcount);
+}
+
+void ib_device_put(struct ib_device *device);
struct net_device *ib_get_net_dev_by_params(struct ib_device *dev, u8 port,
u16 pkey, const union ib_gid *gid,
const struct sockaddr *addr);