scsi: core: sysfs: Make use of bus callbacks

Introduce a bus-specific probe, remove and shutdown function. For now
this only allows to get rid of a cast of the generic device to a SCSI
device in the drivers and changes the remove prototype to return
void---a non-zero return value is ignored anyhow.

The objective is to get rid of users of struct device_driver callbacks
.probe(), .remove() and .shutdown() to eventually remove these. Until
all SCSI drivers are converted, this results in a runtime warning about
the drivers needing an update because there is a bus probe function and
a driver probe function. The in-tree drivers are fixed by the following
commits.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Reviewed-by: Peter Wang <peter.wang@mediatek.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/a54e363a3fd2054fb924afd7df44bca7f444b5f1.1766133330.git.u.kleine-koenig@baylibre.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

2 files changed, 74 insertions, 2 deletions

diff --git a/drivers/scsi/scsi_sysfs.c b/drivers/scsi/scsi_sysfs.c
index db0ba68f2e6e..6b8c5c05f294 100644
--- a/drivers/scsi/scsi_sysfs.c
+++ b/drivers/scsi/scsi_sysfs.c
@@ -554,10 +554,48 @@ static int scsi_bus_uevent(const struct device *dev, struct kobj_uevent_env *env
 	return 0;
 }
 
+static int scsi_bus_probe(struct device *dev)
+{
+	struct scsi_device *sdp = to_scsi_device(dev);
+	struct scsi_driver *drv = to_scsi_driver(dev->driver);
+
+	if (drv->probe)
+		return drv->probe(sdp);
+	else
+		return 0;
+}
+
+static void scsi_bus_remove(struct device *dev)
+{
+	struct scsi_device *sdp = to_scsi_device(dev);
+	struct scsi_driver *drv = to_scsi_driver(dev->driver);
+
+	if (drv->remove)
+		drv->remove(sdp);
+}
+
+static void scsi_bus_shutdown(struct device *dev)
+{
+	struct scsi_device *sdp = to_scsi_device(dev);
+	struct scsi_driver *drv;
+
+	if (!dev->driver)
+		return;
+
+	drv = to_scsi_driver(dev->driver);
+
+	if (drv->shutdown)
+		drv->shutdown(sdp);
+}
+
+
 const struct bus_type scsi_bus_type = {
-        .name		= "scsi",
-        .match		= scsi_bus_match,
+	.name		= "scsi",
+	.match		= scsi_bus_match,
 	.uevent		= scsi_bus_uevent,
+	.probe		= scsi_bus_probe,
+	.remove		= scsi_bus_remove,
+	.shutdown	= scsi_bus_shutdown,
 #ifdef CONFIG_PM
 	.pm		= &scsi_bus_pm_ops,
 #endif
@@ -1554,6 +1592,30 @@ restart:
 }
 EXPORT_SYMBOL(scsi_remove_target);
 
+static int scsi_legacy_probe(struct scsi_device *sdp)
+{
+	struct device *dev = &sdp->sdev_gendev;
+	struct device_driver *driver = dev->driver;
+
+	return driver->probe(dev);
+}
+
+static void scsi_legacy_remove(struct scsi_device *sdp)
+{
+	struct device *dev = &sdp->sdev_gendev;
+	struct device_driver *driver = dev->driver;
+
+	driver->remove(dev);
+}
+
+static void scsi_legacy_shutdown(struct scsi_device *sdp)
+{
+	struct device *dev = &sdp->sdev_gendev;
+	struct device_driver *driver = dev->driver;
+
+	driver->shutdown(dev);
+}
+
 int __scsi_register_driver(struct scsi_driver *sdrv, struct module *owner)
 {
 	struct device_driver *drv = &sdrv->gendrv;
@@ -1561,6 +1623,13 @@ int __scsi_register_driver(struct scsi_driver *sdrv, struct module *owner)
 	drv->bus = &scsi_bus_type;
 	drv->owner = owner;
 
+	if (!sdrv->probe && drv->probe)
+		sdrv->probe = scsi_legacy_probe;
+	if (!sdrv->remove && drv->remove)
+		sdrv->remove = scsi_legacy_remove;
+	if (!sdrv->shutdown && drv->shutdown)
+		sdrv->shutdown = scsi_legacy_shutdown;
+
 	return driver_register(drv);
 }
 EXPORT_SYMBOL(__scsi_register_driver);
diff --git a/include/scsi/scsi_driver.h b/include/scsi/scsi_driver.h
index 40aba9a9349a..249cea724abd 100644
--- a/include/scsi/scsi_driver.h
+++ b/include/scsi/scsi_driver.h
@@ -12,6 +12,9 @@ struct request;
 struct scsi_driver {
 	struct device_driver	gendrv;
 
+	int (*probe)(struct scsi_device *);
+	void (*remove)(struct scsi_device *);
+	void (*shutdown)(struct scsi_device *);
 	int (*resume)(struct device *);
 	void (*rescan)(struct device *);
 	blk_status_t (*init_command)(struct scsi_cmnd *);