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path: root/drivers/base/bus.c
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Diffstat (limited to 'drivers/base/bus.c')
-rw-r--r--drivers/base/bus.c90
1 files changed, 73 insertions, 17 deletions
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 84a21084d67d..9eb7771706f0 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -57,7 +57,7 @@ static int __must_check bus_rescan_devices_helper(struct device *dev,
* NULL. A call to subsys_put() must be done when finished with the pointer in
* order for it to be properly freed.
*/
-static struct subsys_private *bus_to_subsys(const struct bus_type *bus)
+struct subsys_private *bus_to_subsys(const struct bus_type *bus)
{
struct subsys_private *sp = NULL;
struct kobject *kobj;
@@ -152,7 +152,8 @@ static ssize_t bus_attr_show(struct kobject *kobj, struct attribute *attr,
{
struct bus_attribute *bus_attr = to_bus_attr(attr);
struct subsys_private *subsys_priv = to_subsys_private(kobj);
- ssize_t ret = 0;
+ /* return -EIO for reading a bus attribute without show() */
+ ssize_t ret = -EIO;
if (bus_attr->show)
ret = bus_attr->show(subsys_priv->bus, buf);
@@ -164,7 +165,8 @@ static ssize_t bus_attr_store(struct kobject *kobj, struct attribute *attr,
{
struct bus_attribute *bus_attr = to_bus_attr(attr);
struct subsys_private *subsys_priv = to_subsys_private(kobj);
- ssize_t ret = 0;
+ /* return -EIO for writing a bus attribute without store() */
+ ssize_t ret = -EIO;
if (bus_attr->store)
ret = bus_attr->store(subsys_priv->bus, buf, count);
@@ -332,6 +334,19 @@ static struct device *next_device(struct klist_iter *i)
return dev;
}
+static struct device *prev_device(struct klist_iter *i)
+{
+ struct klist_node *n = klist_prev(i);
+ struct device *dev = NULL;
+ struct device_private *dev_prv;
+
+ if (n) {
+ dev_prv = to_device_private_bus(n);
+ dev = dev_prv->device;
+ }
+ return dev;
+}
+
/**
* bus_for_each_dev - device iterator.
* @bus: bus type.
@@ -352,7 +367,7 @@ static struct device *next_device(struct klist_iter *i)
* count in the supplied callback.
*/
int bus_for_each_dev(const struct bus_type *bus, struct device *start,
- void *data, int (*fn)(struct device *, void *))
+ void *data, device_iter_t fn)
{
struct subsys_private *sp = bus_to_subsys(bus);
struct klist_iter i;
@@ -389,7 +404,7 @@ EXPORT_SYMBOL_GPL(bus_for_each_dev);
*/
struct device *bus_find_device(const struct bus_type *bus,
struct device *start, const void *data,
- int (*match)(struct device *dev, const void *data))
+ device_match_t match)
{
struct subsys_private *sp = bus_to_subsys(bus);
struct klist_iter i;
@@ -400,15 +415,43 @@ struct device *bus_find_device(const struct bus_type *bus,
klist_iter_init_node(&sp->klist_devices, &i,
(start ? &start->p->knode_bus : NULL));
- while ((dev = next_device(&i)))
- if (match(dev, data) && get_device(dev))
+ while ((dev = next_device(&i))) {
+ if (match(dev, data)) {
+ get_device(dev);
break;
+ }
+ }
klist_iter_exit(&i);
subsys_put(sp);
return dev;
}
EXPORT_SYMBOL_GPL(bus_find_device);
+struct device *bus_find_device_reverse(const struct bus_type *bus,
+ struct device *start, const void *data,
+ device_match_t match)
+{
+ struct subsys_private *sp = bus_to_subsys(bus);
+ struct klist_iter i;
+ struct device *dev;
+
+ if (!sp)
+ return NULL;
+
+ klist_iter_init_node(&sp->klist_devices, &i,
+ (start ? &start->p->knode_bus : NULL));
+ while ((dev = prev_device(&i))) {
+ if (match(dev, data)) {
+ get_device(dev);
+ break;
+ }
+ }
+ klist_iter_exit(&i);
+ subsys_put(sp);
+ return dev;
+}
+EXPORT_SYMBOL_GPL(bus_find_device_reverse);
+
static struct device_driver *next_driver(struct klist_iter *i)
{
struct klist_node *n = klist_next(i);
@@ -528,8 +571,7 @@ void bus_probe_device(struct device *dev)
if (!sp)
return;
- if (sp->drivers_autoprobe)
- device_initial_probe(dev);
+ device_initial_probe(dev);
mutex_lock(&sp->mutex);
list_for_each_entry(sif, &sp->interfaces, node)
@@ -674,7 +716,12 @@ int bus_add_driver(struct device_driver *drv)
if (error)
goto out_del_list;
}
- module_add_driver(drv->owner, drv);
+ error = module_add_driver(drv->owner, drv);
+ if (error) {
+ printk(KERN_ERR "%s: failed to create module links for %s\n",
+ __func__, drv->name);
+ goto out_detach;
+ }
error = driver_create_file(drv, &driver_attr_uevent);
if (error) {
@@ -699,6 +746,8 @@ int bus_add_driver(struct device_driver *drv)
return 0;
+out_detach:
+ driver_detach(drv);
out_del_list:
klist_del(&priv->knode_bus);
out_unregister:
@@ -913,6 +962,8 @@ bus_devices_fail:
bus_remove_file(bus, &bus_attr_uevent);
bus_uevent_fail:
kset_unregister(&priv->subsys);
+ /* Above kset_unregister() will kfree @priv */
+ priv = NULL;
out:
kfree(priv);
return retval;
@@ -1030,7 +1081,7 @@ static void device_insertion_sort_klist(struct device *a, struct list_head *list
list_move_tail(&a->p->knode_bus.n_node, list);
}
-void bus_sort_breadthfirst(struct bus_type *bus,
+void bus_sort_breadthfirst(const struct bus_type *bus,
int (*compare)(const struct device *a,
const struct device *b))
{
@@ -1194,7 +1245,7 @@ static void system_root_device_release(struct device *dev)
kfree(dev);
}
-static int subsys_register(struct bus_type *subsys,
+static int subsys_register(const struct bus_type *subsys,
const struct attribute_group **groups,
struct kobject *parent_of_root)
{
@@ -1264,7 +1315,7 @@ err_sp:
* directory itself and not some create fake root-device placed in
* /sys/devices/system/<name>.
*/
-int subsys_system_register(struct bus_type *subsys,
+int subsys_system_register(const struct bus_type *subsys,
const struct attribute_group **groups)
{
return subsys_register(subsys, groups, &system_kset->kobj);
@@ -1277,17 +1328,17 @@ EXPORT_SYMBOL_GPL(subsys_system_register);
* @groups: default attributes for the root device
*
* All 'virtual' subsystems have a /sys/devices/system/<name> root device
- * with the name of the subystem. The root device can carry subsystem-wide
+ * with the name of the subsystem. The root device can carry subsystem-wide
* attributes. All registered devices are below this single root device.
* There's no restriction on device naming. This is for kernel software
* constructs which need sysfs interface.
*/
-int subsys_virtual_register(struct bus_type *subsys,
+int subsys_virtual_register(const struct bus_type *subsys,
const struct attribute_group **groups)
{
struct kobject *virtual_dir;
- virtual_dir = virtual_device_parent(NULL);
+ virtual_dir = virtual_device_parent();
if (!virtual_dir)
return -ENOMEM;
@@ -1378,8 +1429,13 @@ int __init buses_init(void)
return -ENOMEM;
system_kset = kset_create_and_add("system", NULL, &devices_kset->kobj);
- if (!system_kset)
+ if (!system_kset) {
+ /* Do error handling here as devices_init() do */
+ kset_unregister(bus_kset);
+ bus_kset = NULL;
+ pr_err("%s: failed to create and add kset 'bus'\n", __func__);
return -ENOMEM;
+ }
return 0;
}
generated by cgit (git 2.34.1) at 2025-12-24 21:06:37 +0000