diff options
Diffstat (limited to 'drivers/base/bus.c')
| -rw-r--r-- | drivers/base/bus.c | 73 |
1 files changed, 61 insertions, 12 deletions
diff --git a/drivers/base/bus.c b/drivers/base/bus.c index ffea0728b8b2..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) @@ -920,6 +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; @@ -1284,7 +1328,7 @@ 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. @@ -1294,7 +1338,7 @@ int subsys_virtual_register(const struct bus_type *subsys, { struct kobject *virtual_dir; - virtual_dir = virtual_device_parent(NULL); + virtual_dir = virtual_device_parent(); if (!virtual_dir) return -ENOMEM; @@ -1385,8 +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; } |