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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.c299
1 files changed, 52 insertions, 247 deletions
diff --git a/drivers/base/bus.c b/drivers/base/bus.c
index 3cb04bb04c2b..43722af90bdd 100644
--- a/drivers/base/bus.c
+++ b/drivers/base/bus.c
@@ -17,9 +17,6 @@
#include "base.h"
#include "power/power.h"
-#define to_dev(node) container_of(node, struct device, bus_list)
-#define to_drv(node) container_of(node, struct device_driver, kobj.entry)
-
#define to_bus_attr(_attr) container_of(_attr, struct bus_attribute, attr)
#define to_bus(obj) container_of(obj, struct bus_type, subsys.kset.kobj)
@@ -36,7 +33,7 @@ drv_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
{
struct driver_attribute * drv_attr = to_drv_attr(attr);
struct device_driver * drv = to_driver(kobj);
- ssize_t ret = 0;
+ ssize_t ret = -EIO;
if (drv_attr->show)
ret = drv_attr->show(drv, buf);
@@ -49,7 +46,7 @@ drv_attr_store(struct kobject * kobj, struct attribute * attr,
{
struct driver_attribute * drv_attr = to_drv_attr(attr);
struct device_driver * drv = to_driver(kobj);
- ssize_t ret = 0;
+ ssize_t ret = -EIO;
if (drv_attr->store)
ret = drv_attr->store(drv, buf, count);
@@ -135,50 +132,11 @@ static struct kobj_type ktype_bus = {
decl_subsys(bus, &ktype_bus, NULL);
-static int __bus_for_each_dev(struct bus_type *bus, struct device *start,
- void *data, int (*fn)(struct device *, void *))
-{
- struct list_head *head;
- struct device *dev;
- int error = 0;
-
- if (!(bus = get_bus(bus)))
- return -EINVAL;
-
- head = &bus->devices.list;
- dev = list_prepare_entry(start, head, bus_list);
- list_for_each_entry_continue(dev, head, bus_list) {
- get_device(dev);
- error = fn(dev, data);
- put_device(dev);
- if (error)
- break;
- }
- put_bus(bus);
- return error;
-}
-static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
- void * data, int (*fn)(struct device_driver *, void *))
+static struct device * next_device(struct klist_iter * i)
{
- struct list_head *head;
- struct device_driver *drv;
- int error = 0;
-
- if (!(bus = get_bus(bus)))
- return -EINVAL;
-
- head = &bus->drivers.list;
- drv = list_prepare_entry(start, head, kobj.entry);
- list_for_each_entry_continue(drv, head, kobj.entry) {
- get_driver(drv);
- error = fn(drv, data);
- put_driver(drv);
- if (error)
- break;
- }
- put_bus(bus);
- return error;
+ struct klist_node * n = klist_next(i);
+ return n ? container_of(n, struct device, knode_bus) : NULL;
}
/**
@@ -204,12 +162,27 @@ static int __bus_for_each_drv(struct bus_type *bus, struct device_driver *start,
int bus_for_each_dev(struct bus_type * bus, struct device * start,
void * data, int (*fn)(struct device *, void *))
{
- int ret;
+ struct klist_iter i;
+ struct device * dev;
+ int error = 0;
- down_read(&bus->subsys.rwsem);
- ret = __bus_for_each_dev(bus, start, data, fn);
- up_read(&bus->subsys.rwsem);
- return ret;
+ if (!bus)
+ return -EINVAL;
+
+ klist_iter_init_node(&bus->klist_devices, &i,
+ (start ? &start->knode_bus : NULL));
+ while ((dev = next_device(&i)) && !error)
+ error = fn(dev, data);
+ klist_iter_exit(&i);
+ return error;
+}
+
+
+
+static struct device_driver * next_driver(struct klist_iter * i)
+{
+ struct klist_node * n = klist_next(i);
+ return n ? container_of(n, struct device_driver, knode_bus) : NULL;
}
/**
@@ -235,179 +208,19 @@ int bus_for_each_dev(struct bus_type * bus, struct device * start,
int bus_for_each_drv(struct bus_type * bus, struct device_driver * start,
void * data, int (*fn)(struct device_driver *, void *))
{
- int ret;
-
- down_read(&bus->subsys.rwsem);
- ret = __bus_for_each_drv(bus, start, data, fn);
- up_read(&bus->subsys.rwsem);
- return ret;
-}
-
-/**
- * device_bind_driver - bind a driver to one device.
- * @dev: device.
- *
- * Allow manual attachment of a driver to a device.
- * Caller must have already set @dev->driver.
- *
- * Note that this does not modify the bus reference count
- * nor take the bus's rwsem. Please verify those are accounted
- * for before calling this. (It is ok to call with no other effort
- * from a driver's probe() method.)
- */
-
-void device_bind_driver(struct device * dev)
-{
- pr_debug("bound device '%s' to driver '%s'\n",
- dev->bus_id, dev->driver->name);
- list_add_tail(&dev->driver_list, &dev->driver->devices);
- sysfs_create_link(&dev->driver->kobj, &dev->kobj,
- kobject_name(&dev->kobj));
- sysfs_create_link(&dev->kobj, &dev->driver->kobj, "driver");
-}
-
-
-/**
- * driver_probe_device - attempt to bind device & driver.
- * @drv: driver.
- * @dev: device.
- *
- * First, we call the bus's match function, if one present, which
- * should compare the device IDs the driver supports with the
- * device IDs of the device. Note we don't do this ourselves
- * because we don't know the format of the ID structures, nor what
- * is to be considered a match and what is not.
- *
- * If we find a match, we call @drv->probe(@dev) if it exists, and
- * call device_bind_driver() above.
- */
-int driver_probe_device(struct device_driver * drv, struct device * dev)
-{
- if (drv->bus->match && !drv->bus->match(dev, drv))
- return -ENODEV;
-
- dev->driver = drv;
- if (drv->probe) {
- int error = drv->probe(dev);
- if (error) {
- dev->driver = NULL;
- return error;
- }
- }
-
- device_bind_driver(dev);
- return 0;
-}
-
-
-/**
- * device_attach - try to attach device to a driver.
- * @dev: device.
- *
- * Walk the list of drivers that the bus has and call
- * driver_probe_device() for each pair. If a compatible
- * pair is found, break out and return.
- */
-int device_attach(struct device * dev)
-{
- struct bus_type * bus = dev->bus;
- struct list_head * entry;
- int error;
-
- if (dev->driver) {
- device_bind_driver(dev);
- return 1;
- }
-
- if (bus->match) {
- list_for_each(entry, &bus->drivers.list) {
- struct device_driver * drv = to_drv(entry);
- error = driver_probe_device(drv, dev);
- if (!error)
- /* success, driver matched */
- return 1;
- if (error != -ENODEV && error != -ENXIO)
- /* driver matched but the probe failed */
- printk(KERN_WARNING
- "%s: probe of %s failed with error %d\n",
- drv->name, dev->bus_id, error);
- }
- }
-
- return 0;
-}
-
-
-/**
- * driver_attach - try to bind driver to devices.
- * @drv: driver.
- *
- * Walk the list of devices that the bus has on it and try to
- * match the driver with each one. If driver_probe_device()
- * returns 0 and the @dev->driver is set, we've found a
- * compatible pair.
- *
- * Note that we ignore the -ENODEV error from driver_probe_device(),
- * since it's perfectly valid for a driver not to bind to any devices.
- */
-void driver_attach(struct device_driver * drv)
-{
- struct bus_type * bus = drv->bus;
- struct list_head * entry;
- int error;
-
- if (!bus->match)
- return;
-
- list_for_each(entry, &bus->devices.list) {
- struct device * dev = container_of(entry, struct device, bus_list);
- if (!dev->driver) {
- error = driver_probe_device(drv, dev);
- if (error && (error != -ENODEV))
- /* driver matched but the probe failed */
- printk(KERN_WARNING
- "%s: probe of %s failed with error %d\n",
- drv->name, dev->bus_id, error);
- }
- }
-}
-
-
-/**
- * device_release_driver - manually detach device from driver.
- * @dev: device.
- *
- * Manually detach device from driver.
- * Note that this is called without incrementing the bus
- * reference count nor taking the bus's rwsem. Be sure that
- * those are accounted for before calling this function.
- */
-
-void device_release_driver(struct device * dev)
-{
- struct device_driver * drv = dev->driver;
- if (drv) {
- sysfs_remove_link(&drv->kobj, kobject_name(&dev->kobj));
- sysfs_remove_link(&dev->kobj, "driver");
- list_del_init(&dev->driver_list);
- if (drv->remove)
- drv->remove(dev);
- dev->driver = NULL;
- }
-}
-
+ struct klist_iter i;
+ struct device_driver * drv;
+ int error = 0;
-/**
- * driver_detach - detach driver from all devices it controls.
- * @drv: driver.
- */
+ if (!bus)
+ return -EINVAL;
-static void driver_detach(struct device_driver * drv)
-{
- while (!list_empty(&drv->devices)) {
- struct device * dev = container_of(drv->devices.next, struct device, driver_list);
- device_release_driver(dev);
- }
+ klist_iter_init_node(&bus->klist_drivers, &i,
+ start ? &start->knode_bus : NULL);
+ while ((drv = next_driver(&i)) && !error)
+ error = fn(drv, data);
+ klist_iter_exit(&i);
+ return error;
}
static int device_add_attrs(struct bus_type * bus, struct device * dev)
@@ -456,14 +269,15 @@ int bus_add_device(struct device * dev)
int error = 0;
if (bus) {
- down_write(&dev->bus->subsys.rwsem);
pr_debug("bus %s: add device %s\n", bus->name, dev->bus_id);
- list_add_tail(&dev->bus_list, &dev->bus->devices.list);
- device_attach(dev);
- up_write(&dev->bus->subsys.rwsem);
- device_add_attrs(bus, dev);
- sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);
- sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
+ error = device_attach(dev);
+ klist_add_tail(&bus->klist_devices, &dev->knode_bus);
+ if (error >= 0)
+ error = device_add_attrs(bus, dev);
+ if (!error) {
+ sysfs_create_link(&bus->devices.kobj, &dev->kobj, dev->bus_id);
+ sysfs_create_link(&dev->kobj, &dev->bus->subsys.kset.kobj, "bus");
+ }
}
return error;
}
@@ -483,11 +297,9 @@ void bus_remove_device(struct device * dev)
sysfs_remove_link(&dev->kobj, "bus");
sysfs_remove_link(&dev->bus->devices.kobj, dev->bus_id);
device_remove_attrs(dev->bus, dev);
- down_write(&dev->bus->subsys.rwsem);
+ klist_remove(&dev->knode_bus);
pr_debug("bus %s: remove device %s\n", dev->bus->name, dev->bus_id);
device_release_driver(dev);
- list_del_init(&dev->bus_list);
- up_write(&dev->bus->subsys.rwsem);
put_bus(dev->bus);
}
}
@@ -547,9 +359,8 @@ int bus_add_driver(struct device_driver * drv)
return error;
}
- down_write(&bus->subsys.rwsem);
driver_attach(drv);
- up_write(&bus->subsys.rwsem);
+ klist_add_tail(&bus->klist_drivers, &drv->knode_bus);
module_add_driver(drv->owner, drv);
driver_add_attrs(bus, drv);
@@ -571,10 +382,9 @@ void bus_remove_driver(struct device_driver * drv)
{
if (drv->bus) {
driver_remove_attrs(drv->bus, drv);
- down_write(&drv->bus->subsys.rwsem);
+ klist_remove(&drv->knode_bus);
pr_debug("bus %s: remove driver %s\n", drv->bus->name, drv->name);
driver_detach(drv);
- up_write(&drv->bus->subsys.rwsem);
module_remove_driver(drv);
kobject_unregister(&drv->kobj);
put_bus(drv->bus);
@@ -587,7 +397,7 @@ static int bus_rescan_devices_helper(struct device *dev, void *data)
{
int *count = data;
- if (!dev->driver && device_attach(dev))
+ if (!dev->driver && (device_attach(dev) > 0))
(*count)++;
return 0;
@@ -607,9 +417,7 @@ int bus_rescan_devices(struct bus_type * bus)
{
int count = 0;
- down_write(&bus->subsys.rwsem);
- __bus_for_each_dev(bus, NULL, &count, bus_rescan_devices_helper);
- up_write(&bus->subsys.rwsem);
+ bus_for_each_dev(bus, NULL, &count, bus_rescan_devices_helper);
return count;
}
@@ -710,6 +518,9 @@ int bus_register(struct bus_type * bus)
retval = kset_register(&bus->drivers);
if (retval)
goto bus_drivers_fail;
+
+ klist_init(&bus->klist_devices);
+ klist_init(&bus->klist_drivers);
bus_add_attrs(bus);
pr_debug("bus type '%s' registered\n", bus->name);
@@ -749,12 +560,6 @@ int __init buses_init(void)
EXPORT_SYMBOL_GPL(bus_for_each_dev);
EXPORT_SYMBOL_GPL(bus_for_each_drv);
-EXPORT_SYMBOL_GPL(driver_probe_device);
-EXPORT_SYMBOL_GPL(device_bind_driver);
-EXPORT_SYMBOL_GPL(device_release_driver);
-EXPORT_SYMBOL_GPL(device_attach);
-EXPORT_SYMBOL_GPL(driver_attach);
-
EXPORT_SYMBOL_GPL(bus_add_device);
EXPORT_SYMBOL_GPL(bus_remove_device);
EXPORT_SYMBOL_GPL(bus_register);