driver core: generalize driver_override in struct device

index b97e13a52c33..ae57df879bca 100644
@@ -463,6 +463,36 @@ int bus_for_each_drv(const struct bus_type *bus, struct device_driver *start,
 }
 EXPORT_SYMBOL_GPL(bus_for_each_drv);
 
+static ssize_t driver_override_store(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf, size_t count)
+{
+	int ret;
+
+	ret = __device_set_driver_override(dev, buf, count);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static ssize_t driver_override_show(struct device *dev,
+				    struct device_attribute *attr, char *buf)
+{
+	guard(spinlock)(&dev->driver_override.lock);
+	return sysfs_emit(buf, "%s\n", dev->driver_override.name);
+}
+static DEVICE_ATTR_RW(driver_override);
+
+static struct attribute *driver_override_dev_attrs[] = {
+	&dev_attr_driver_override.attr,
+	NULL,
+};
+
+static const struct attribute_group driver_override_dev_group = {
+	.attrs = driver_override_dev_attrs,
+};
+
 /**
  * bus_add_device - add device to bus
  * @dev: device being added

@@ -496,9 +526,15 @@ int bus_add_device(struct device *dev)
 	if (error)
 		goto out_put;
 
+	if (dev->bus->driver_override) {
+		error = device_add_group(dev, &driver_override_dev_group);
+		if (error)
+			goto out_groups;
+	}
+
 	error = sysfs_create_link(&sp->devices_kset->kobj, &dev->kobj, dev_name(dev));
 	if (error)
-		goto out_groups;
+		goto out_override;
 
 	error = sysfs_create_link(&dev->kobj, &sp->subsys.kobj, "subsystem");
 	if (error)

@@ -509,6 +545,9 @@ int bus_add_device(struct device *dev)
 
 out_subsys:
 	sysfs_remove_link(&sp->devices_kset->kobj, dev_name(dev));
+out_override:
+	if (dev->bus->driver_override)
+		device_remove_group(dev, &driver_override_dev_group);
 out_groups:
 	device_remove_groups(dev, sp->bus->dev_groups);
 out_put:

@@ -567,6 +606,8 @@ void bus_remove_device(struct device *dev)
 
 	sysfs_remove_link(&dev->kobj, "subsystem");
 	sysfs_remove_link(&sp->devices_kset->kobj, dev_name(dev));
+	if (dev->bus->driver_override)
+		device_remove_group(dev, &driver_override_dev_group);
 	device_remove_groups(dev, dev->bus->dev_groups);
 	if (klist_node_attached(&dev->p->knode_bus))
 		klist_del(&dev->p->knode_bus);

index 3c172e6d3fe0..5048849cb97a 100644
@@ -2505,6 +2505,7 @@ static void device_release(struct kobject *kobj)
 	devres_release_all(dev);
 
 	kfree(dev->dma_range_map);
+	kfree(dev->driver_override.name);
 
 	if (dev->release)
 		dev->release(dev);

@@ -3153,6 +3154,7 @@ void device_initialize(struct device *dev)
 	kobject_init(&dev->kobj, &device_ktype);
 	INIT_LIST_HEAD(&dev->dma_pools);
 	mutex_init(&dev->mutex);
+	spin_lock_init(&dev->driver_override.lock);
 	lockdep_set_novalidate_class(&dev->mutex);
 	spin_lock_init(&dev->devres_lock);
 	INIT_LIST_HEAD(&dev->devres_head);

66 lines not on this page · raw message

72 lines not on this page · raw message

index ae10c4322754..d43ce072d747 100644
@@ -65,6 +65,9 @@ struct fwnode_handle;
  * @iommu_ops:  IOMMU specific operations for this bus, used to attach IOMMU
  *              driver implementations to a bus and allow the driver to do
  *              bus-specific setup
+ * @driver_override:	Set to true if this bus supports the driver_override
+ *			mechanism, which allows userspace to force a specific
+ *			driver to bind to a device via a sysfs attribute.
  * @need_parent_lock:	When probing or removing a device on this bus, the
  *			device core should lock the device's parent.
  *

@@ -106,6 +109,7 @@ struct bus_type {
 
 	const struct iommu_ops *iommu_ops;
 
+	bool driver_override;
 	bool need_parent_lock;
 };
 

index 76bfcba25003..1cc9a876b3cd 100644
@@ -561,7 +561,6 @@ static void platform_device_release(struct device *dev)
 	kfree(pa->pdev.dev.platform_data);
 	kfree(pa->pdev.mfd_cell);
 	kfree(pa->pdev.resource);
-	kfree(pa->pdev.driver_override);
 	kfree(pa);
 }
 

@@ -1265,38 +1264,9 @@ static ssize_t numa_node_show(struct device *dev,
 }
 static DEVICE_ATTR_RO(numa_node);
 
-static ssize_t driver_override_show(struct device *dev,
-				    struct device_attribute *attr, char *buf)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-	ssize_t len;
-
-	device_lock(dev);
-	len = sysfs_emit(buf, "%s\n", pdev->driver_override);
-	device_unlock(dev);
-
-	return len;
-}
-
-static ssize_t driver_override_store(struct device *dev,
-				     struct device_attribute *attr,
-				     const char *buf, size_t count)
-{
-	struct platform_device *pdev = to_platform_device(dev);
-	int ret;
-
-	ret = driver_set_override(dev, &pdev->driver_override, buf, count);
-	if (ret)
-		return ret;
-
-	return count;
-}
-static DEVICE_ATTR_RW(driver_override);
-
 static struct attribute *platform_dev_attrs[] = {
 	&dev_attr_modalias.attr,
 	&dev_attr_numa_node.attr,
-	&dev_attr_driver_override.attr,
 	NULL,
 };
 

@@ -1336,10 +1306,12 @@ static int platform_match(struct device *dev, struct device_driver *drv)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct platform_driver *pdrv = to_platform_driver(drv);
+	int ret;
 
 	/* When driver_override is set, only bind to the matching driver */
-	if (pdev->driver_override)
-		return !strcmp(pdev->driver_override, drv->name);
+	ret = device_match_driver_override(dev, drv);
+	if (ret >= 0)
+		return ret;
 
 	/* Attempt an OF style match first */
 	if (of_driver_match_device(dev, drv))

@@ -1482,6 +1454,7 @@ static const struct dev_pm_ops platform_dev_pm_ops = {
 struct bus_type platform_bus_type = {
 	.name		= "platform",
 	.dev_groups	= platform_dev_groups,
+	.driver_override = true,
 	.match		= platform_match,
 	.uevent		= platform_uevent,
 	.probe		= platform_probe,

index aafcc481de91..cb71774400d4 100644
@@ -36,7 +36,7 @@ static int simple_pm_bus_probe(struct platform_device *pdev)
 	 * that's not listed in simple_pm_bus_of_match. We don't want to do any
 	 * of the simple-pm-bus tasks for these devices, so return early.
 	 */
-	if (pdev->driver_override)
+	if (device_has_driver_override(&pdev->dev))
 		return 0;
 
 	match = of_match_device(dev->driver->of_match_table, dev);

@@ -78,7 +78,7 @@ static int simple_pm_bus_remove(struct platform_device *pdev)
 {
 	const void *data = of_device_get_match_data(&pdev->dev);
 
-	if (pdev->driver_override || data)
+	if (device_has_driver_override(&pdev->dev) || data)
 		return 0;
 
 	dev_dbg(&pdev->dev, "%s\n", __func__);

index 564f549ec204..3a68576cdae7 100644
@@ -700,8 +700,7 @@ struct clk_hw *imx_clk_scu_alloc_dev(const char *name,
 		return ERR_PTR(ret);
 	}
 
-	ret = driver_set_override(&pdev->dev, &pdev->driver_override,
-				  "imx-scu-clk", strlen("imx-scu-clk"));
+	ret = device_set_driver_override(&pdev->dev, "imx-scu-clk");
 	if (ret) {
 		platform_device_put(pdev);
 		return ERR_PTR(ret);

index fe3a96577f31..d0d289c49c8d 100644
@@ -1537,10 +1537,8 @@ static int of_qcom_slim_ngd_register(struct device *parent,
 		ngd->id = id;
 		ngd->pdev->dev.parent = parent;
 
-		ret = driver_set_override(&ngd->pdev->dev,
-					  &ngd->pdev->driver_override,
-					  QCOM_SLIM_NGD_DRV_NAME,
-					  strlen(QCOM_SLIM_NGD_DRV_NAME));
+		ret = device_set_driver_override(&ngd->pdev->dev,
+						 QCOM_SLIM_NGD_DRV_NAME);
 		if (ret) {
 			platform_device_put(ngd->pdev);
 			kfree(ngd);

index 7a41c72c1959..8828b0d275d7 100644
@@ -31,11 +31,6 @@ struct platform_device {
 	struct resource	*resource;
 
 	const struct platform_device_id	*id_entry;
-	/*
-	 * Driver name to force a match.  Do not set directly, because core
-	 * frees it.  Use driver_set_override() to set or clear it.
-	 */
-	const char *driver_override;
 
 	/* MFD cell pointer */
 	struct mfd_cell *mfd_cell;

index 3af48c9b5ab7..925782e67673 100644
@@ -1364,10 +1364,10 @@ static int i2s_create_secondary_device(struct samsung_i2s_priv *priv)
 	if (!pdev_sec)
 		return -ENOMEM;
 
-	pdev_sec->driver_override = kstrdup("samsung-i2s", GFP_KERNEL);
-	if (!pdev_sec->driver_override) {
+	ret = device_set_driver_override(&pdev_sec->dev, "samsung-i2s");
+	if (ret) {
 		platform_device_put(pdev_sec);
-		return -ENOMEM;
+		return ret;
 	}
 
 	ret = platform_device_add(pdev_sec);