Xen: consolidate and simplify struct xenbus_driver instantiation

The 'name', 'owner', and 'mod_name' members are redundant with the
identically named fields in the 'driver' sub-structure. Rather than
switching each instance to specify these fields explicitly, introduce
a macro to simplify this.

Eliminate further redundancy by allowing the drvname argument to
DEFINE_XENBUS_DRIVER() to be blank (in which case the first entry from
the ID table will be used for .driver.name).

Also eliminate the questionable xenbus_register_{back,front}end()
wrappers - their sole remaining purpose was the checking of the
'owner' field, proper setting of which shouldn't be an issue anymore
when the macro gets used.

v2: Restore DRV_NAME for the driver name in xen-pciback.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Ian Campbell <ian.campbell@citrix.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 5 insertions, 8 deletions

diff --git a/drivers/xen/xen-pciback/xenbus.c b/drivers/xen/xen-pciback/xenbus.c
index 075525945e36..c80f9c84d08e 100644
--- a/drivers/xen/xen-pciback/xenbus.c
+++ b/drivers/xen/xen-pciback/xenbus.c
@@ -707,19 +707,16 @@ static int xen_pcibk_xenbus_remove(struct xenbus_device *dev)
         return 0;
 }
 
-static const struct xenbus_device_id xenpci_ids[] = {
+static const struct xenbus_device_id xen_pcibk_ids[] = {
         {"pci"},
         {""},
 };
 
-static struct xenbus_driver xenbus_xen_pcibk_driver = {
-        .name                   = DRV_NAME,
-        .owner                  = THIS_MODULE,
-        .ids                    = xenpci_ids,
+static DEFINE_XENBUS_DRIVER(xen_pcibk, DRV_NAME,
         .probe                  = xen_pcibk_xenbus_probe,
         .remove                 = xen_pcibk_xenbus_remove,
         .otherend_changed       = xen_pcibk_frontend_changed,
-};
+);
 
 const struct xen_pcibk_backend *__read_mostly xen_pcibk_backend;
 
@@ -735,11 +732,11 @@ int __init xen_pcibk_xenbus_register(void)
         if (passthrough)
                 xen_pcibk_backend = &xen_pcibk_passthrough_backend;
         pr_info(DRV_NAME ": backend is %s\n", xen_pcibk_backend->name);
-        return xenbus_register_backend(&xenbus_xen_pcibk_driver);
+        return xenbus_register_backend(&xen_pcibk_driver);
 }
 
 void __exit xen_pcibk_xenbus_unregister(void)
 {
         destroy_workqueue(xen_pcibk_wq);
-        xenbus_unregister_driver(&xenbus_xen_pcibk_driver);
+        xenbus_unregister_driver(&xen_pcibk_driver);
 }