From f75b1c60fc1e53c4004a79ea0be071aa3318cdcc Mon Sep 17 00:00:00 2001 From: Dave Young Date: Wed, 28 May 2008 09:28:39 -0700 Subject: [PATCH] class: change internal semaphore to a mutex Now that the lockdep infrastructure in the class core is in place, we should be able to properly change the internal class semaphore to be a mutex. David wrote the original patch, and Greg fixed it up to apply properly due to all of the recent changes in this area. From: Dave Young Cc: Matthew Wilcox Cc: Kay Sievers Cc: Andrew Morton Cc: James Bottomley Signed-off-by: Greg Kroah-Hartman --- drivers/base/base.h | 4 ++-- drivers/base/class.c | 23 ++++++++++++----------- drivers/base/core.c | 9 +++++---- 3 files changed, 19 insertions(+), 17 deletions(-) diff --git a/drivers/base/base.h b/drivers/base/base.h index c035dc2326..31dc0cd84a 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -44,7 +44,7 @@ struct driver_private { * @class_devices - list of devices associated with this class * @class_interfaces - list of class_interfaces associated with this class * @class_dirs - "glue" directory for virtual devices associated with this class - * @class_sem - semaphore to protect the children, devices, and interfaces lists. + * @class_mutex - mutex to protect the children, devices, and interfaces lists. * @class - pointer back to the struct class that this structure is associated * with. * @@ -57,7 +57,7 @@ struct class_private { struct list_head class_devices; struct list_head class_interfaces; struct kset class_dirs; - struct semaphore class_sem; + struct mutex class_mutex; struct class *class; }; #define to_class(obj) \ diff --git a/drivers/base/class.c b/drivers/base/class.c index 8900056669..839d27cecb 100644 --- a/drivers/base/class.c +++ b/drivers/base/class.c @@ -18,6 +18,7 @@ #include #include #include +#include #include "base.h" #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr) @@ -147,7 +148,7 @@ int __class_register(struct class *cls, struct lock_class_key *key) INIT_LIST_HEAD(&cp->class_devices); INIT_LIST_HEAD(&cp->class_interfaces); kset_init(&cp->class_dirs); - init_MUTEX(&cp->class_sem); + __mutex_init(&cp->class_mutex, "struct class mutex", key); error = kobject_set_name(&cp->class_subsys.kobj, "%s", cls->name); if (error) { kfree(cp); @@ -281,7 +282,7 @@ char *make_class_name(const char *name, struct kobject *kobj) * We check the return of @fn each time. If it returns anything * other than 0, we break out and return that value. * - * Note, we hold class->class_sem in this function, so it can not be + * Note, we hold class->class_mutex in this function, so it can not be * re-acquired in @fn, otherwise it will self-deadlocking. For * example, calls to add or remove class members would be verboten. */ @@ -293,7 +294,7 @@ int class_for_each_device(struct class *class, struct device *start, if (!class) return -EINVAL; - down(&class->p->class_sem); + mutex_lock(&class->p->class_mutex); list_for_each_entry(dev, &class->p->class_devices, node) { if (start) { if (start == dev) @@ -306,7 +307,7 @@ int class_for_each_device(struct class *class, struct device *start, if (error) break; } - up(&class->p->class_sem); + mutex_unlock(&class->p->class_mutex); return error; } @@ -329,7 +330,7 @@ EXPORT_SYMBOL_GPL(class_for_each_device); * * Note, you will need to drop the reference with put_device() after use. * - * We hold class->class_sem in this function, so it can not be + * We hold class->class_mutex in this function, so it can not be * re-acquired in @match, otherwise it will self-deadlocking. For * example, calls to add or remove class members would be verboten. */ @@ -343,7 +344,7 @@ struct device *class_find_device(struct class *class, struct device *start, if (!class) return NULL; - down(&class->p->class_sem); + mutex_lock(&class->p->class_mutex); list_for_each_entry(dev, &class->p->class_devices, node) { if (start) { if (start == dev) @@ -357,7 +358,7 @@ struct device *class_find_device(struct class *class, struct device *start, } else put_device(dev); } - up(&class->p->class_sem); + mutex_unlock(&class->p->class_mutex); return found ? dev : NULL; } @@ -375,13 +376,13 @@ int class_interface_register(struct class_interface *class_intf) if (!parent) return -EINVAL; - down(&parent->p->class_sem); + mutex_lock(&parent->p->class_mutex); list_add_tail(&class_intf->node, &parent->p->class_interfaces); if (class_intf->add_dev) { list_for_each_entry(dev, &parent->p->class_devices, node) class_intf->add_dev(dev, class_intf); } - up(&parent->p->class_sem); + mutex_unlock(&parent->p->class_mutex); return 0; } @@ -394,13 +395,13 @@ void class_interface_unregister(struct class_interface *class_intf) if (!parent) return; - down(&parent->p->class_sem); + mutex_lock(&parent->p->class_mutex); list_del_init(&class_intf->node); if (class_intf->remove_dev) { list_for_each_entry(dev, &parent->p->class_devices, node) class_intf->remove_dev(dev, class_intf); } - up(&parent->p->class_sem); + mutex_unlock(&parent->p->class_mutex); class_put(parent); } diff --git a/drivers/base/core.c b/drivers/base/core.c index b90ae6f7be..c05b115902 100644 --- a/drivers/base/core.c +++ b/drivers/base/core.c @@ -21,6 +21,7 @@ #include #include #include +#include #include "base.h" #include "power/power.h" @@ -907,7 +908,7 @@ int device_add(struct device *dev) klist_add_tail(&dev->knode_parent, &parent->klist_children); if (dev->class) { - down(&dev->class->p->class_sem); + mutex_lock(&dev->class->p->class_mutex); /* tie the class to the device */ list_add_tail(&dev->node, &dev->class->p->class_devices); @@ -916,7 +917,7 @@ int device_add(struct device *dev) &dev->class->p->class_interfaces, node) if (class_intf->add_dev) class_intf->add_dev(dev, class_intf); - up(&dev->class->p->class_sem); + mutex_unlock(&dev->class->p->class_mutex); } Done: put_device(dev); @@ -1017,7 +1018,7 @@ void device_del(struct device *dev) if (dev->class) { device_remove_class_symlinks(dev); - down(&dev->class->p->class_sem); + mutex_lock(&dev->class->p->class_mutex); /* notify any interfaces that the device is now gone */ list_for_each_entry(class_intf, &dev->class->p->class_interfaces, node) @@ -1025,7 +1026,7 @@ void device_del(struct device *dev) class_intf->remove_dev(dev, class_intf); /* remove the device from the class list */ list_del_init(&dev->node); - up(&dev->class->p->class_sem); + mutex_unlock(&dev->class->p->class_mutex); } device_remove_file(dev, &uevent_attr); device_remove_attrs(dev); -- 2.39.5