Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm
[sfrench/cifs-2.6.git] / drivers / base / class.c
index 4d2222618b780f47dfa54e40246dbd9e4c8bdcc7..412fd9a05573e742117fced63ed4210512fbe79d 100644 (file)
 #include <linux/kdev_t.h>
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/genhd.h>
 #include "base.h"
 
 #define to_class_attr(_attr) container_of(_attr, struct class_attribute, attr)
 #define to_class(obj) container_of(obj, struct class, subsys.kobj)
 
-static ssize_t
-class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
+static ssize_t class_attr_show(struct kobject *kobj, struct attribute *attr,
+                              char *buf)
 {
-       struct class_attribute * class_attr = to_class_attr(attr);
-       struct class * dc = to_class(kobj);
+       struct class_attribute *class_attr = to_class_attr(attr);
+       struct class *dc = to_class(kobj);
        ssize_t ret = -EIO;
 
        if (class_attr->show)
@@ -34,12 +35,11 @@ class_attr_show(struct kobject * kobj, struct attribute * attr, char * buf)
        return ret;
 }
 
-static ssize_t
-class_attr_store(struct kobject * kobj, struct attribute * attr,
-                const char * buf, size_t count)
+static ssize_t class_attr_store(struct kobject *kobj, struct attribute *attr,
+                               const char *buf, size_t count)
 {
-       struct class_attribute * class_attr = to_class_attr(attr);
-       struct class * dc = to_class(kobj);
+       struct class_attribute *class_attr = to_class_attr(attr);
+       struct class *dc = to_class(kobj);
        ssize_t ret = -EIO;
 
        if (class_attr->store)
@@ -47,7 +47,7 @@ class_attr_store(struct kobject * kobj, struct attribute * attr,
        return ret;
 }
 
-static void class_release(struct kobject * kobj)
+static void class_release(struct kobject *kobj)
 {
        struct class *class = to_class(kobj);
 
@@ -65,26 +65,26 @@ static struct sysfs_ops class_sysfs_ops = {
        .store  = class_attr_store,
 };
 
-static struct kobj_type ktype_class = {
+static struct kobj_type class_ktype = {
        .sysfs_ops      = &class_sysfs_ops,
        .release        = class_release,
 };
 
 /* Hotplug events for classes go to the class_obj subsys */
-static decl_subsys(class, &ktype_class, NULL);
+static struct kset *class_kset;
 
 
-int class_create_file(struct class * cls, const struct class_attribute * attr)
+int class_create_file(struct class *cls, const struct class_attribute *attr)
 {
        int error;
-       if (cls) {
+       if (cls)
                error = sysfs_create_file(&cls->subsys.kobj, &attr->attr);
-       else
+       else
                error = -EINVAL;
        return error;
 }
 
-void class_remove_file(struct class * cls, const struct class_attribute * attr)
+void class_remove_file(struct class *cls, const struct class_attribute *attr)
 {
        if (cls)
                sysfs_remove_file(&cls->subsys.kobj, &attr->attr);
@@ -93,48 +93,48 @@ void class_remove_file(struct class * cls, const struct class_attribute * attr)
 static struct class *class_get(struct class *cls)
 {
        if (cls)
-               return container_of(subsys_get(&cls->subsys), struct class, subsys);
+               return container_of(kset_get(&cls->subsys),
+                                   struct class, subsys);
        return NULL;
 }
 
-static void class_put(struct class * cls)
+static void class_put(struct class *cls)
 {
        if (cls)
-               subsys_put(&cls->subsys);
+               kset_put(&cls->subsys);
 }
 
-
-static int add_class_attrs(struct class * cls)
+static int add_class_attrs(struct class *cls)
 {
        int i;
        int error = 0;
 
        if (cls->class_attrs) {
                for (i = 0; attr_name(cls->class_attrs[i]); i++) {
-                       error = class_create_file(cls,&cls->class_attrs[i]);
+                       error = class_create_file(cls, &cls->class_attrs[i]);
                        if (error)
-                               goto Err;
+                               goto error;
                }
        }
- Done:
+done:
        return error;
- Err:
+error:
        while (--i >= 0)
-               class_remove_file(cls,&cls->class_attrs[i]);
-       goto Done;
+               class_remove_file(cls, &cls->class_attrs[i]);
+       goto done;
 }
 
-static void remove_class_attrs(struct class * cls)
+static void remove_class_attrs(struct class *cls)
 {
        int i;
 
        if (cls->class_attrs) {
                for (i = 0; attr_name(cls->class_attrs[i]); i++)
-                       class_remove_file(cls,&cls->class_attrs[i]);
+                       class_remove_file(cls, &cls->class_attrs[i]);
        }
 }
 
-int class_register(struct class * cls)
+int class_register(struct class *cls)
 {
        int error;
 
@@ -149,9 +149,16 @@ int class_register(struct class * cls)
        if (error)
                return error;
 
-       subsys_set_kset(cls, class_subsys);
+#ifdef CONFIG_SYSFS_DEPRECATED
+       /* let the block class directory show up in the root of sysfs */
+       if (cls != &block_class)
+               cls->subsys.kobj.kset = class_kset;
+#else
+       cls->subsys.kobj.kset = class_kset;
+#endif
+       cls->subsys.kobj.ktype = &class_ktype;
 
-       error = subsystem_register(&cls->subsys);
+       error = kset_register(&cls->subsys);
        if (!error) {
                error = add_class_attrs(class_get(cls));
                class_put(cls);
@@ -159,11 +166,11 @@ int class_register(struct class * cls)
        return error;
 }
 
-void class_unregister(struct class * cls)
+void class_unregister(struct class *cls)
 {
        pr_debug("device class '%s': unregistering\n", cls->name);
        remove_class_attrs(cls);
-       subsystem_unregister(&cls->subsys);
+       kset_unregister(&cls->subsys);
 }
 
 static void class_create_release(struct class *cls)
@@ -180,8 +187,7 @@ static void class_device_create_release(struct class_device *class_dev)
 
 /* needed to allow these devices to have parent class devices */
 static int class_device_create_uevent(struct class_device *class_dev,
-                                      char **envp, int num_envp,
-                                      char *buffer, int buffer_size)
+                                     struct kobj_uevent_env *env)
 {
        pr_debug("%s called for %s\n", __FUNCTION__, class_dev->class_id);
        return 0;
@@ -242,8 +248,8 @@ void class_destroy(struct class *cls)
 
 /* Class Device Stuff */
 
-int class_device_create_file(struct class_device * class_dev,
-                            const struct class_device_attribute * attr)
+int class_device_create_file(struct class_device *class_dev,
+                            const struct class_device_attribute *attr)
 {
        int error = -EINVAL;
        if (class_dev)
@@ -251,8 +257,8 @@ int class_device_create_file(struct class_device * class_dev,
        return error;
 }
 
-void class_device_remove_file(struct class_device * class_dev,
-                             const struct class_device_attribute * attr)
+void class_device_remove_file(struct class_device *class_dev,
+                             const struct class_device_attribute *attr)
 {
        if (class_dev)
                sysfs_remove_file(&class_dev->kobj, &attr->attr);
@@ -274,12 +280,11 @@ void class_device_remove_bin_file(struct class_device *class_dev,
                sysfs_remove_bin_file(&class_dev->kobj, attr);
 }
 
-static ssize_t
-class_device_attr_show(struct kobject * kobj, struct attribute * attr,
-                      char * buf)
+static ssize_t class_device_attr_show(struct kobject *kobj,
+                                     struct attribute *attr, char *buf)
 {
-       struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
-       struct class_device * cd = to_class_dev(kobj);
+       struct class_device_attribute *class_dev_attr = to_class_dev_attr(attr);
+       struct class_device *cd = to_class_dev(kobj);
        ssize_t ret = 0;
 
        if (class_dev_attr->show)
@@ -287,12 +292,12 @@ class_device_attr_show(struct kobject * kobj, struct attribute * attr,
        return ret;
 }
 
-static ssize_t
-class_device_attr_store(struct kobject * kobj, struct attribute * attr,
-                       const char * buf, size_t count)
+static ssize_t class_device_attr_store(struct kobject *kobj,
+                                      struct attribute *attr,
+                                      const char *buf, size_t count)
 {
-       struct class_device_attribute * class_dev_attr = to_class_dev_attr(attr);
-       struct class_device * cd = to_class_dev(kobj);
+       struct class_device_attribute *class_dev_attr = to_class_dev_attr(attr);
+       struct class_device *cd = to_class_dev(kobj);
        ssize_t ret = 0;
 
        if (class_dev_attr->store)
@@ -305,10 +310,10 @@ static struct sysfs_ops class_dev_sysfs_ops = {
        .store  = class_device_attr_store,
 };
 
-static void class_dev_release(struct kobject * kobj)
+static void class_dev_release(struct kobject *kobj)
 {
        struct class_device *cd = to_class_dev(kobj);
-       struct class * cls = cd->class;
+       struct class *cls = cd->class;
 
        pr_debug("device class '%s': release.\n", cd->class_id);
 
@@ -317,14 +322,14 @@ static void class_dev_release(struct kobject * kobj)
        else if (cls->release)
                cls->release(cd);
        else {
-               printk(KERN_ERR "Class Device '%s' does not have a release() function, "
-                       "it is broken and must be fixed.\n",
+               printk(KERN_ERR "Class Device '%s' does not have a release() "
+                       "function, it is broken and must be fixed.\n",
                        cd->class_id);
                WARN_ON(1);
        }
 }
 
-static struct kobj_type ktype_class_device = {
+static struct kobj_type class_device_ktype = {
        .sysfs_ops      = &class_dev_sysfs_ops,
        .release        = class_dev_release,
 };
@@ -333,7 +338,7 @@ static int class_uevent_filter(struct kset *kset, struct kobject *kobj)
 {
        struct kobj_type *ktype = get_ktype(kobj);
 
-       if (ktype == &ktype_class_device) {
+       if (ktype == &class_device_ktype) {
                struct class_device *class_dev = to_class_dev(kobj);
                if (class_dev->class)
                        return 1;
@@ -403,64 +408,44 @@ static void remove_deprecated_class_device_links(struct class_device *cd)
 { }
 #endif
 
-static int class_uevent(struct kset *kset, struct kobject *kobj, char **envp,
-                        int num_envp, char *buffer, int buffer_size)
+static int class_uevent(struct kset *kset, struct kobject *kobj,
+                       struct kobj_uevent_env *env)
 {
        struct class_device *class_dev = to_class_dev(kobj);
        struct device *dev = class_dev->dev;
-       int i = 0;
-       int length = 0;
        int retval = 0;
 
        pr_debug("%s - name = %s\n", __FUNCTION__, class_dev->class_id);
 
        if (MAJOR(class_dev->devt)) {
-               add_uevent_var(envp, num_envp, &i,
-                              buffer, buffer_size, &length,
-                              "MAJOR=%u", MAJOR(class_dev->devt));
+               add_uevent_var(env, "MAJOR=%u", MAJOR(class_dev->devt));
 
-               add_uevent_var(envp, num_envp, &i,
-                              buffer, buffer_size, &length,
-                              "MINOR=%u", MINOR(class_dev->devt));
+               add_uevent_var(env, "MINOR=%u", MINOR(class_dev->devt));
        }
 
        if (dev) {
                const char *path = kobject_get_path(&dev->kobj, GFP_KERNEL);
                if (path) {
-                       add_uevent_var(envp, num_envp, &i,
-                                      buffer, buffer_size, &length,
-                                      "PHYSDEVPATH=%s", path);
+                       add_uevent_var(env, "PHYSDEVPATH=%s", path);
                        kfree(path);
                }
 
                if (dev->bus)
-                       add_uevent_var(envp, num_envp, &i,
-                                      buffer, buffer_size, &length,
-                                      "PHYSDEVBUS=%s", dev->bus->name);
+                       add_uevent_var(env, "PHYSDEVBUS=%s", dev->bus->name);
 
                if (dev->driver)
-                       add_uevent_var(envp, num_envp, &i,
-                                      buffer, buffer_size, &length,
-                                      "PHYSDEVDRIVER=%s", dev->driver->name);
+                       add_uevent_var(env, "PHYSDEVDRIVER=%s",
+                                      dev->driver->name);
        }
 
-       /* terminate, set to next free slot, shrink available space */
-       envp[i] = NULL;
-       envp = &envp[i];
-       num_envp -= i;
-       buffer = &buffer[length];
-       buffer_size -= length;
-
        if (class_dev->uevent) {
                /* have the class device specific function add its stuff */
-               retval = class_dev->uevent(class_dev, envp, num_envp,
-                                           buffer, buffer_size);
+               retval = class_dev->uevent(class_dev, env);
                if (retval)
                        pr_debug("class_dev->uevent() returned %d\n", retval);
        } else if (class_dev->class->uevent) {
                /* have the class specific function add its stuff */
-               retval = class_dev->class->uevent(class_dev, envp, num_envp,
-                                                  buffer, buffer_size);
+               retval = class_dev->class->uevent(class_dev, env);
                if (retval)
                        pr_debug("class->uevent() returned %d\n", retval);
        }
@@ -474,43 +459,49 @@ static struct kset_uevent_ops class_uevent_ops = {
        .uevent =       class_uevent,
 };
 
-static decl_subsys(class_obj, &ktype_class_device, &class_uevent_ops);
-
+/*
+ * DO NOT copy how this is created, kset_create_and_add() should be
+ * called, but this is a hold-over from the old-way and will be deleted
+ * entirely soon.
+ */
+static struct kset class_obj_subsys = {
+       .uevent_ops = &class_uevent_ops,
+};
 
-static int class_device_add_attrs(struct class_device * cd)
+static int class_device_add_attrs(struct class_device *cd)
 {
        int i;
        int error = 0;
-       struct class * cls = cd->class;
+       struct class *cls = cd->class;
 
        if (cls->class_dev_attrs) {
                for (i = 0; attr_name(cls->class_dev_attrs[i]); i++) {
                        error = class_device_create_file(cd,
-                                                        &cls->class_dev_attrs[i]);
+                                               &cls->class_dev_attrs[i]);
                        if (error)
-                               goto Err;
+                               goto err;
                }
        }
- Done:
+done:
        return error;
- Err:
+err:
        while (--i >= 0)
-               class_device_remove_file(cd,&cls->class_dev_attrs[i]);
-       goto Done;
+               class_device_remove_file(cd, &cls->class_dev_attrs[i]);
+       goto done;
 }
 
-static void class_device_remove_attrs(struct class_device * cd)
+static void class_device_remove_attrs(struct class_device *cd)
 {
        int i;
-       struct class * cls = cd->class;
+       struct class *cls = cd->class;
 
        if (cls->class_dev_attrs) {
                for (i = 0; attr_name(cls->class_dev_attrs[i]); i++)
-                       class_device_remove_file(cd,&cls->class_dev_attrs[i]);
+                       class_device_remove_file(cd, &cls->class_dev_attrs[i]);
        }
 }
 
-static int class_device_add_groups(struct class_device * cd)
+static int class_device_add_groups(struct class_device *cd)
 {
        int i;
        int error = 0;
@@ -520,7 +511,8 @@ static int class_device_add_groups(struct class_device * cd)
                        error = sysfs_create_group(&cd->kobj, cd->groups[i]);
                        if (error) {
                                while (--i >= 0)
-                                       sysfs_remove_group(&cd->kobj, cd->groups[i]);
+                                       sysfs_remove_group(&cd->kobj,
+                                                          cd->groups[i]);
                                goto out;
                        }
                }
@@ -529,14 +521,12 @@ out:
        return error;
 }
 
-static void class_device_remove_groups(struct class_device * cd)
+static void class_device_remove_groups(struct class_device *cd)
 {
        int i;
-       if (cd->groups) {
-               for (i = 0; cd->groups[i]; i++) {
+       if (cd->groups)
+               for (i = 0; cd->groups[i]; i++)
                        sysfs_remove_group(&cd->kobj, cd->groups[i]);
-               }
-       }
 }
 
 static ssize_t show_dev(struct class_device *class_dev, char *buf)
@@ -559,8 +549,8 @@ static struct class_device_attribute class_uevent_attr =
 
 void class_device_initialize(struct class_device *class_dev)
 {
-       kobj_set_kset_s(class_dev, class_obj_subsys);
-       kobject_init(&class_dev->kobj);
+       class_dev->kobj.kset = &class_obj_subsys;
+       kobject_init(&class_dev->kobj, &class_device_ktype);
        INIT_LIST_HEAD(&class_dev->node);
 }
 
@@ -588,16 +578,13 @@ int class_device_add(struct class_device *class_dev)
                 class_dev->class_id);
 
        /* first, register with generic layer. */
-       error = kobject_set_name(&class_dev->kobj, "%s", class_dev->class_id);
-       if (error)
-               goto out2;
-
        if (parent_class_dev)
                class_dev->kobj.parent = &parent_class_dev->kobj;
        else
                class_dev->kobj.parent = &parent_class->subsys.kobj;
 
-       error = kobject_add(&class_dev->kobj);
+       error = kobject_add(&class_dev->kobj, class_dev->kobj.parent,
+                           "%s", class_dev->class_id);
        if (error)
                goto out2;
 
@@ -664,7 +651,7 @@ int class_device_add(struct class_device *class_dev)
  out3:
        kobject_del(&class_dev->kobj);
  out2:
-       if(parent_class_dev)
+       if (parent_class_dev)
                class_device_put(parent_class_dev);
        class_put(parent_class);
  out1:
@@ -681,9 +668,11 @@ int class_device_register(struct class_device *class_dev)
 /**
  * class_device_create - creates a class device and registers it with sysfs
  * @cls: pointer to the struct class that this device should be registered to.
- * @parent: pointer to the parent struct class_device of this new device, if any.
+ * @parent: pointer to the parent struct class_device of this new device, if
+ * any.
  * @devt: the dev_t for the char device to be added.
- * @device: a pointer to a struct device that is assiociated with this class device.
+ * @device: a pointer to a struct device that is assiociated with this class
+ * device.
  * @fmt: string for the class device's name
  *
  * This function can be used by char device classes.  A struct
@@ -807,7 +796,7 @@ void class_device_destroy(struct class *cls, dev_t devt)
                class_device_unregister(class_dev);
 }
 
-struct class_device * class_device_get(struct class_device *class_dev)
+struct class_device *class_device_get(struct class_device *class_dev)
 {
        if (class_dev)
                return to_class_dev(kobject_get(&class_dev->kobj));
@@ -820,6 +809,139 @@ void class_device_put(struct class_device *class_dev)
                kobject_put(&class_dev->kobj);
 }
 
+/**
+ * class_for_each_device - device iterator
+ * @class: the class we're iterating
+ * @data: data for the callback
+ * @fn: function to be called for each device
+ *
+ * Iterate over @class's list of devices, and call @fn for each,
+ * passing it @data.
+ *
+ * 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->sem 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.
+ */
+int class_for_each_device(struct class *class, void *data,
+                          int (*fn)(struct device *, void *))
+{
+       struct device *dev;
+       int error = 0;
+
+       if (!class)
+               return -EINVAL;
+       down(&class->sem);
+       list_for_each_entry(dev, &class->devices, node) {
+               dev = get_device(dev);
+               if (dev) {
+                       error = fn(dev, data);
+                       put_device(dev);
+               } else
+                       error = -ENODEV;
+               if (error)
+                       break;
+       }
+       up(&class->sem);
+
+       return error;
+}
+EXPORT_SYMBOL_GPL(class_for_each_device);
+
+/**
+ * class_find_device - device iterator for locating a particular device
+ * @class: the class we're iterating
+ * @data: data for the match function
+ * @match: function to check device
+ *
+ * This is similar to the class_for_each_dev() function above, but it
+ * returns a reference to a device that is 'found' for later use, as
+ * determined by the @match callback.
+ *
+ * The callback should return 0 if the device doesn't match and non-zero
+ * if it does.  If the callback returns non-zero, this function will
+ * return to the caller and not iterate over any more devices.
+ *
+ * Note, you will need to drop the reference with put_device() after use.
+ *
+ * We hold class->sem 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.
+ */
+struct device *class_find_device(struct class *class, void *data,
+                                  int (*match)(struct device *, void *))
+{
+       struct device *dev;
+       int found = 0;
+
+       if (!class)
+               return NULL;
+
+       down(&class->sem);
+       list_for_each_entry(dev, &class->devices, node) {
+               dev = get_device(dev);
+               if (dev) {
+                       if (match(dev, data)) {
+                               found = 1;
+                               break;
+                       } else
+                               put_device(dev);
+               } else
+                       break;
+       }
+       up(&class->sem);
+
+       return found ? dev : NULL;
+}
+EXPORT_SYMBOL_GPL(class_find_device);
+
+/**
+ * class_find_child - device iterator for locating a particular class_device
+ * @class: the class we're iterating
+ * @data: data for the match function
+ * @match: function to check class_device
+ *
+ * This function returns a reference to a class_device that is 'found' for
+ * later use, as determined by the @match callback.
+ *
+ * The callback should return 0 if the class_device doesn't match and non-zero
+ * if it does.  If the callback returns non-zero, this function will
+ * return to the caller and not iterate over any more class_devices.
+ *
+ * Note, you will need to drop the reference with class_device_put() after use.
+ *
+ * We hold class->sem 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.
+ */
+struct class_device *class_find_child(struct class *class, void *data,
+                                  int (*match)(struct class_device *, void *))
+{
+       struct class_device *dev;
+       int found = 0;
+
+       if (!class)
+               return NULL;
+
+       down(&class->sem);
+       list_for_each_entry(dev, &class->children, node) {
+               dev = class_device_get(dev);
+               if (dev) {
+                       if (match(dev, data)) {
+                               found = 1;
+                               break;
+                       } else
+                               class_device_put(dev);
+               } else
+                       break;
+       }
+       up(&class->sem);
+
+       return found ? dev : NULL;
+}
+EXPORT_SYMBOL_GPL(class_find_child);
 
 int class_interface_register(struct class_interface *class_intf)
 {
@@ -851,7 +973,7 @@ int class_interface_register(struct class_interface *class_intf)
 
 void class_interface_unregister(struct class_interface *class_intf)
 {
-       struct class * parent = class_intf->class;
+       struct class *parent = class_intf->class;
        struct class_device *class_dev;
        struct device *dev;
 
@@ -875,15 +997,14 @@ void class_interface_unregister(struct class_interface *class_intf)
 
 int __init classes_init(void)
 {
-       int retval;
-
-       retval = subsystem_register(&class_subsys);
-       if (retval)
-               return retval;
+       class_kset = kset_create_and_add("class", NULL, NULL);
+       if (!class_kset)
+               return -ENOMEM;
 
        /* ick, this is ugly, the things we go through to keep from showing up
         * in sysfs... */
-       subsystem_init(&class_obj_subsys);
+       kset_init(&class_obj_subsys);
+       kobject_set_name(&class_obj_subsys.kobj, "class_obj");
        if (!class_obj_subsys.kobj.parent)
                class_obj_subsys.kobj.parent = &class_obj_subsys.kobj;
        return 0;