1 files changed, 60 insertions, 145 deletions

diff --git a/drivers/s390/cio/ccwgroup.c b/drivers/s390/cio/ccwgroup.c
index 34b9ad6b3143..185c99c5d4cc 100644
--- a/drivers/s390/cio/ccwgroup.c
+++ b/drivers/s390/cio/ccwgroup.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *  bus driver for ccwgroup
  *
@@ -6,6 +7,8 @@
  *  Author(s): Arnd Bergmann (arndb@de.ibm.com)
  *	       Cornelia Huck (cornelia.huck@de.ibm.com)
  */
+
+#include <linux/export.h>
 #include <linux/module.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
@@ -30,7 +33,7 @@
  * to devices that use multiple subchannels.
  */
 
-static struct bus_type ccwgroup_bus_type;
+static const struct bus_type ccwgroup_bus_type;
 
 static void __ccwgroup_remove_symlinks(struct ccwgroup_device *gdev)
 {
@@ -38,33 +41,12 @@ static void __ccwgroup_remove_symlinks(struct ccwgroup_device *gdev)
 	char str[16];
 
 	for (i = 0; i < gdev->count; i++) {
-		sprintf(str, "cdev%d", i);
+		scnprintf(str, sizeof(str), "cdev%d", i);
 		sysfs_remove_link(&gdev->dev.kobj, str);
 		sysfs_remove_link(&gdev->cdev[i]->dev.kobj, "group_device");
 	}
 }
 
-/*
- * Remove references from ccw devices to ccw group device and from
- * ccw group device to ccw devices.
- */
-static void __ccwgroup_remove_cdev_refs(struct ccwgroup_device *gdev)
-{
-	struct ccw_device *cdev;
-	int i;
-
-	for (i = 0; i < gdev->count; i++) {
-		cdev = gdev->cdev[i];
-		if (!cdev)
-			continue;
-		spin_lock_irq(cdev->ccwlock);
-		dev_set_drvdata(&cdev->dev, NULL);
-		spin_unlock_irq(cdev->ccwlock);
-		gdev->cdev[i] = NULL;
-		put_device(&cdev->dev);
-	}
-}
-
 /**
  * ccwgroup_set_online() - enable a ccwgroup device
  * @gdev: target ccwgroup device
@@ -97,12 +79,13 @@ EXPORT_SYMBOL(ccwgroup_set_online);
 /**
  * ccwgroup_set_offline() - disable a ccwgroup device
  * @gdev: target ccwgroup device
+ * @call_gdrv: Call the registered gdrv set_offline function
  *
  * This function attempts to put the ccwgroup device into the offline state.
  * Returns:
  *  %0 on success and a negative error value on failure.
  */
-int ccwgroup_set_offline(struct ccwgroup_device *gdev)
+int ccwgroup_set_offline(struct ccwgroup_device *gdev, bool call_gdrv)
 {
 	struct ccwgroup_driver *gdrv = to_ccwgroupdrv(gdev->dev.driver);
 	int ret = -EINVAL;
@@ -111,11 +94,16 @@ int ccwgroup_set_offline(struct ccwgroup_device *gdev)
 		return -EAGAIN;
 	if (gdev->state == CCWGROUP_OFFLINE)
 		goto out;
+	if (!call_gdrv) {
+		ret = 0;
+		goto offline;
+	}
 	if (gdrv->set_offline)
 		ret = gdrv->set_offline(gdev);
 	if (ret)
 		goto out;
 
+offline:
 	gdev->state = CCWGROUP_OFFLINE;
 out:
 	atomic_set(&gdev->onoff, 0);
@@ -144,7 +132,7 @@ static ssize_t ccwgroup_online_store(struct device *dev,
 	if (value == 1)
 		ret = ccwgroup_set_online(gdev);
 	else if (value == 0)
-		ret = ccwgroup_set_offline(gdev);
+		ret = ccwgroup_set_offline(gdev, true);
 	else
 		ret = -EINVAL;
 out:
@@ -161,12 +149,12 @@ static ssize_t ccwgroup_online_show(struct device *dev,
 
 	online = (gdev->state == CCWGROUP_ONLINE) ? 1 : 0;
 
-	return scnprintf(buf, PAGE_SIZE, "%d\n", online);
+	return sysfs_emit(buf, "%d\n", online);
 }
 
 /*
  * Provide an 'ungroup' attribute so the user can remove group devices no
- * longer needed or accidentially created. Saves memory :)
+ * longer needed or accidentally created. Saves memory :)
  */
 static void ccwgroup_ungroup(struct ccwgroup_device *gdev)
 {
@@ -174,7 +162,6 @@ static void ccwgroup_ungroup(struct ccwgroup_device *gdev)
 	if (device_is_registered(&gdev->dev)) {
 		__ccwgroup_remove_symlinks(gdev);
 		device_unregister(&gdev->dev);
-		__ccwgroup_remove_cdev_refs(gdev);
 	}
 	mutex_unlock(&gdev->reg_mutex);
 }
@@ -209,18 +196,12 @@ out:
 static DEVICE_ATTR(ungroup, 0200, NULL, ccwgroup_ungroup_store);
 static DEVICE_ATTR(online, 0644, ccwgroup_online_show, ccwgroup_online_store);
 
-static struct attribute *ccwgroup_attrs[] = {
+static struct attribute *ccwgroup_dev_attrs[] = {
 	&dev_attr_online.attr,
 	&dev_attr_ungroup.attr,
 	NULL,
 };
-static struct attribute_group ccwgroup_attr_group = {
-	.attrs = ccwgroup_attrs,
-};
-static const struct attribute_group *ccwgroup_attr_groups[] = {
-	&ccwgroup_attr_group,
-	NULL,
-};
+ATTRIBUTE_GROUPS(ccwgroup_dev);
 
 static void ccwgroup_ungroup_workfn(struct work_struct *work)
 {
@@ -233,7 +214,23 @@ static void ccwgroup_ungroup_workfn(struct work_struct *work)
 
 static void ccwgroup_release(struct device *dev)
 {
-	kfree(to_ccwgroupdev(dev));
+	struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
+	unsigned int i;
+
+	for (i = 0; i < gdev->count; i++) {
+		struct ccw_device *cdev = gdev->cdev[i];
+		unsigned long flags;
+
+		if (cdev) {
+			spin_lock_irqsave(cdev->ccwlock, flags);
+			if (dev_get_drvdata(&cdev->dev) == gdev)
+				dev_set_drvdata(&cdev->dev, NULL);
+			spin_unlock_irqrestore(cdev->ccwlock, flags);
+			put_device(&cdev->dev);
+		}
+	}
+
+	kfree(gdev);
 }
 
 static int __ccwgroup_create_symlinks(struct ccwgroup_device *gdev)
@@ -245,19 +242,19 @@ static int __ccwgroup_create_symlinks(struct ccwgroup_device *gdev)
 		rc = sysfs_create_link(&gdev->cdev[i]->dev.kobj,
 				       &gdev->dev.kobj, "group_device");
 		if (rc) {
-			for (--i; i >= 0; i--)
+			while (i--)
 				sysfs_remove_link(&gdev->cdev[i]->dev.kobj,
 						  "group_device");
 			return rc;
 		}
 	}
 	for (i = 0; i < gdev->count; i++) {
-		sprintf(str, "cdev%d", i);
+		scnprintf(str, sizeof(str), "cdev%d", i);
 		rc = sysfs_create_link(&gdev->dev.kobj,
 				       &gdev->cdev[i]->dev.kobj, str);
 		if (rc) {
-			for (--i; i >= 0; i--) {
-				sprintf(str, "cdev%d", i);
+			while (i--) {
+				scnprintf(str, sizeof(str), "cdev%d", i);
 				sysfs_remove_link(&gdev->dev.kobj, str);
 			}
 			for (i = 0; i < gdev->count; i++)
@@ -322,8 +319,10 @@ int ccwgroup_create_dev(struct device *parent, struct ccwgroup_driver *gdrv,
 	struct ccw_dev_id dev_id;
 	int rc, i;
 
-	gdev = kzalloc(sizeof(*gdev) + num_devices * sizeof(gdev->cdev[0]),
-		       GFP_KERNEL);
+	if (num_devices < 1)
+		return -EINVAL;
+
+	gdev = kzalloc(struct_size(gdev, cdev, num_devices), GFP_KERNEL);
 	if (!gdev)
 		return -ENOMEM;
 
@@ -369,13 +368,18 @@ int ccwgroup_create_dev(struct device *parent, struct ccwgroup_driver *gdrv,
 		goto error;
 	}
 	/* Check for trailing stuff. */
-	if (i == num_devices && strlen(buf) > 0) {
+	if (i == num_devices && buf && strlen(buf) > 0) {
+		rc = -EINVAL;
+		goto error;
+	}
+	/* Check if the devices are bound to the required ccw driver. */
+	if (gdrv && gdrv->ccw_driver &&
+	    gdev->cdev[0]->drv != gdrv->ccw_driver) {
 		rc = -EINVAL;
 		goto error;
 	}
 
 	dev_set_name(&gdev->dev, "%s", dev_name(&gdev->cdev[0]->dev));
-	gdev->dev.groups = ccwgroup_attr_groups;
 
 	if (gdrv) {
 		gdev->dev.driver = &gdrv->driver;
@@ -394,15 +398,6 @@ int ccwgroup_create_dev(struct device *parent, struct ccwgroup_driver *gdrv,
 	mutex_unlock(&gdev->reg_mutex);
 	return 0;
 error:
-	for (i = 0; i < num_devices; i++)
-		if (gdev->cdev[i]) {
-			spin_lock_irq(gdev->cdev[i]->ccwlock);
-			if (dev_get_drvdata(&gdev->cdev[i]->dev) == gdev)
-				dev_set_drvdata(&gdev->cdev[i]->dev, NULL);
-			spin_unlock_irq(gdev->cdev[i]->ccwlock);
-			put_device(&gdev->cdev[i]->dev);
-			gdev->cdev[i] = NULL;
-		}
 	mutex_unlock(&gdev->reg_mutex);
 	put_device(&gdev->dev);
 	return rc;
@@ -414,7 +409,7 @@ static int ccwgroup_notifier(struct notifier_block *nb, unsigned long action,
 {
 	struct ccwgroup_device *gdev = to_ccwgroupdev(data);
 
-	if (action == BUS_NOTIFY_UNBIND_DRIVER) {
+	if (action == BUS_NOTIFY_UNBOUND_DRIVER) {
 		get_device(&gdev->dev);
 		schedule_work(&gdev->ungroup_work);
 	}
@@ -452,17 +447,13 @@ module_exit(cleanup_ccwgroup);
 
 /************************** driver stuff ******************************/
 
-static int ccwgroup_remove(struct device *dev)
+static void ccwgroup_remove(struct device *dev)
 {
 	struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
 	struct ccwgroup_driver *gdrv = to_ccwgroupdrv(dev->driver);
 
-	if (!dev->driver)
-		return 0;
 	if (gdrv->remove)
 		gdrv->remove(gdev);
-
-	return 0;
 }
 
 static void ccwgroup_shutdown(struct device *dev)
@@ -476,81 +467,19 @@ static void ccwgroup_shutdown(struct device *dev)
 		gdrv->shutdown(gdev);
 }
 
-static int ccwgroup_pm_prepare(struct device *dev)
-{
-	struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
-	struct ccwgroup_driver *gdrv = to_ccwgroupdrv(gdev->dev.driver);
-
-	/* Fail while device is being set online/offline. */
-	if (atomic_read(&gdev->onoff))
-		return -EAGAIN;
-
-	if (!gdev->dev.driver || gdev->state != CCWGROUP_ONLINE)
-		return 0;
-
-	return gdrv->prepare ? gdrv->prepare(gdev) : 0;
-}
-
-static void ccwgroup_pm_complete(struct device *dev)
-{
-	struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
-	struct ccwgroup_driver *gdrv = to_ccwgroupdrv(dev->driver);
-
-	if (!gdev->dev.driver || gdev->state != CCWGROUP_ONLINE)
-		return;
-
-	if (gdrv->complete)
-		gdrv->complete(gdev);
-}
-
-static int ccwgroup_pm_freeze(struct device *dev)
-{
-	struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
-	struct ccwgroup_driver *gdrv = to_ccwgroupdrv(gdev->dev.driver);
-
-	if (!gdev->dev.driver || gdev->state != CCWGROUP_ONLINE)
-		return 0;
-
-	return gdrv->freeze ? gdrv->freeze(gdev) : 0;
-}
-
-static int ccwgroup_pm_thaw(struct device *dev)
-{
-	struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
-	struct ccwgroup_driver *gdrv = to_ccwgroupdrv(gdev->dev.driver);
-
-	if (!gdev->dev.driver || gdev->state != CCWGROUP_ONLINE)
-		return 0;
-
-	return gdrv->thaw ? gdrv->thaw(gdev) : 0;
-}
-
-static int ccwgroup_pm_restore(struct device *dev)
-{
-	struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
-	struct ccwgroup_driver *gdrv = to_ccwgroupdrv(gdev->dev.driver);
-
-	if (!gdev->dev.driver || gdev->state != CCWGROUP_ONLINE)
-		return 0;
-
-	return gdrv->restore ? gdrv->restore(gdev) : 0;
-}
-
-static const struct dev_pm_ops ccwgroup_pm_ops = {
-	.prepare = ccwgroup_pm_prepare,
-	.complete = ccwgroup_pm_complete,
-	.freeze = ccwgroup_pm_freeze,
-	.thaw = ccwgroup_pm_thaw,
-	.restore = ccwgroup_pm_restore,
-};
-
-static struct bus_type ccwgroup_bus_type = {
+static const struct bus_type ccwgroup_bus_type = {
 	.name   = "ccwgroup",
+	.dev_groups = ccwgroup_dev_groups,
 	.remove = ccwgroup_remove,
 	.shutdown = ccwgroup_shutdown,
-	.pm = &ccwgroup_pm_ops,
 };
 
+bool dev_is_ccwgroup(struct device *dev)
+{
+	return dev->bus == &ccwgroup_bus_type;
+}
+EXPORT_SYMBOL(dev_is_ccwgroup);
+
 /**
  * ccwgroup_driver_register() - register a ccw group driver
  * @cdriver: driver to be registered
@@ -566,11 +495,6 @@ int ccwgroup_driver_register(struct ccwgroup_driver *cdriver)
 }
 EXPORT_SYMBOL(ccwgroup_driver_register);
 
-static int __ccwgroup_match_all(struct device *dev, void *data)
-{
-	return 1;
-}
-
 /**
  * ccwgroup_driver_unregister() - deregister a ccw group driver
  * @cdriver: driver to be deregistered
@@ -579,16 +503,6 @@ static int __ccwgroup_match_all(struct device *dev, void *data)
  */
 void ccwgroup_driver_unregister(struct ccwgroup_driver *cdriver)
 {
-	struct device *dev;
-
-	/* We don't want ccwgroup devices to live longer than their driver. */
-	while ((dev = driver_find_device(&cdriver->driver, NULL, NULL,
-					 __ccwgroup_match_all))) {
-		struct ccwgroup_device *gdev = to_ccwgroupdev(dev);
-
-		ccwgroup_ungroup(gdev);
-		put_device(dev);
-	}
 	driver_unregister(&cdriver->driver);
 }
 EXPORT_SYMBOL(ccwgroup_driver_unregister);
@@ -638,4 +552,5 @@ void ccwgroup_remove_ccwdev(struct ccw_device *cdev)
 	put_device(&gdev->dev);
 }
 EXPORT_SYMBOL(ccwgroup_remove_ccwdev);
+MODULE_DESCRIPTION("ccwgroup bus driver");
 MODULE_LICENSE("GPL");