dibs: Move struct device to dibs_dev

Move struct device from ism_dev and smc_lo_dev to dibs_dev, and define a
corresponding release function. Free ism_dev in ism_remove() and smc_lo_dev
in smc_lo_dev_remove().

Replace smcd->ops->get_dev(smcd) by using dibs->dev directly.

An alternative design would be to embed dibs_dev as a field in ism_dev and
do the same for other dibs device driver specific structs. However that
would have the disadvantage that each dibs device driver needs to allocate
dibs_dev and each dibs device driver needs a different device release
function. The advantage would be that ism_dev and other device driver
specific structs would be covered by device reference counts.

Signed-off-by: Julian Ruess <julianr@linux.ibm.com>
Co-developed-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Reviewed-by: Mahanta Jambigi <mjambigi@linux.ibm.com>
Link: https://patch.msgid.link/20250918110500.1731261-9-wintera@linux.ibm.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

2 files changed, 27 insertions, 9 deletions

diff --git a/drivers/dibs/dibs_loopback.c b/drivers/dibs/dibs_loopback.c
index 215986ae54a4..76e479d5724b 100644
--- a/drivers/dibs/dibs_loopback.c
+++ b/drivers/dibs/dibs_loopback.c
@@ -15,6 +15,7 @@
 
 #include "dibs_loopback.h"
 
+static const char dibs_lo_dev_name[] = "lo";
 /* global loopback device */
 static struct dibs_lo_dev *lo_dev;
 
@@ -27,11 +28,6 @@ static const struct dibs_dev_ops dibs_lo_ops = {
 	.get_fabric_id = dibs_lo_get_fabric_id,
 };
 
-static void dibs_lo_dev_exit(struct dibs_lo_dev *ldev)
-{
-	dibs_dev_del(ldev->dibs);
-}
-
 static int dibs_lo_dev_probe(void)
 {
 	struct dibs_lo_dev *ldev;
@@ -52,6 +48,9 @@ static int dibs_lo_dev_probe(void)
 	dibs->drv_priv = ldev;
 	dibs->ops = &dibs_lo_ops;
 
+	dibs->dev.parent = NULL;
+	dev_set_name(&dibs->dev, "%s", dibs_lo_dev_name);
+
 	ret = dibs_dev_add(dibs);
 	if (ret)
 		goto err_reg;
@@ -60,7 +59,7 @@ static int dibs_lo_dev_probe(void)
 
 err_reg:
 	/* pairs with dibs_dev_alloc() */
-	kfree(dibs);
+	put_device(&dibs->dev);
 	kfree(ldev);
 
 	return ret;
@@ -71,9 +70,9 @@ static void dibs_lo_dev_remove(void)
 	if (!lo_dev)
 		return;
 
-	dibs_lo_dev_exit(lo_dev);
+	dibs_dev_del(lo_dev->dibs);
 	/* pairs with dibs_dev_alloc() */
-	kfree(lo_dev->dibs);
+	put_device(&lo_dev->dibs->dev);
 	kfree(lo_dev);
 	lo_dev = NULL;
 }
diff --git a/drivers/dibs/dibs_main.c b/drivers/dibs/dibs_main.c
index f1cfa5849277..610b6c452211 100644
--- a/drivers/dibs/dibs_main.c
+++ b/drivers/dibs/dibs_main.c
@@ -88,11 +88,24 @@ int dibs_unregister_client(struct dibs_client *client)
 }
 EXPORT_SYMBOL_GPL(dibs_unregister_client);
 
+static void dibs_dev_release(struct device *dev)
+{
+	struct dibs_dev *dibs;
+
+	dibs = container_of(dev, struct dibs_dev, dev);
+
+	kfree(dibs);
+}
+
 struct dibs_dev *dibs_dev_alloc(void)
 {
 	struct dibs_dev *dibs;
 
 	dibs = kzalloc(sizeof(*dibs), GFP_KERNEL);
+	if (!dibs)
+		return dibs;
+	dibs->dev.release = dibs_dev_release;
+	device_initialize(&dibs->dev);
 
 	return dibs;
 }
@@ -100,7 +113,11 @@ EXPORT_SYMBOL_GPL(dibs_dev_alloc);
 
 int dibs_dev_add(struct dibs_dev *dibs)
 {
-	int i;
+	int i, ret;
+
+	ret = device_add(&dibs->dev);
+	if (ret)
+		return ret;
 
 	mutex_lock(&dibs_dev_list.mutex);
 	mutex_lock(&clients_lock);
@@ -129,6 +146,8 @@ void dibs_dev_del(struct dibs_dev *dibs)
 	mutex_unlock(&clients_lock);
 	list_del_init(&dibs->list);
 	mutex_unlock(&dibs_dev_list.mutex);
+
+	device_del(&dibs->dev);
 }
 EXPORT_SYMBOL_GPL(dibs_dev_del);