Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765985AbYAYIZM (ORCPT ); Fri, 25 Jan 2008 03:25:12 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759939AbYAYIBF (ORCPT ); Fri, 25 Jan 2008 03:01:05 -0500 Received: from ns1.suse.de ([195.135.220.2]:59459 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764080AbYAYH7v (ORCPT ); Fri, 25 Jan 2008 02:59:51 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Dave Young , Greg Kroah-Hartman Subject: [PATCH 187/196] Driver Core: add class iteration api Date: Thu, 24 Jan 2008 23:33:36 -0800 Message-Id: <1201246425-5058-108-git-send-email-gregkh@suse.de> X-Mailer: git-send-email 1.5.3.8 In-Reply-To: <20080125071127.GA4860@kroah.com> References: <20080125071127.GA4860@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6029 Lines: 195 From: Dave Young Add the following class iteration functions for driver use: class_for_each_device class_find_device class_for_each_child class_find_child Signed-off-by: Dave Young Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- drivers/base/class.c | 133 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/device.h | 9 +++- 2 files changed, 140 insertions(+), 2 deletions(-) diff --git a/drivers/base/class.c b/drivers/base/class.c index b962a76..9f737ff 100644 --- a/drivers/base/class.c +++ b/drivers/base/class.c @@ -809,6 +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) { diff --git a/include/linux/device.h b/include/linux/device.h index 92ba3a8..cdaf57b 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -177,8 +177,7 @@ struct class { struct list_head devices; struct list_head interfaces; struct kset class_dirs; - struct semaphore sem; /* locks both the children and interfaces lists */ - + struct semaphore sem; /* locks children, devices, interfaces */ struct class_attribute * class_attrs; struct class_device_attribute * class_dev_attrs; struct device_attribute * dev_attrs; @@ -196,6 +195,12 @@ struct class { extern int __must_check class_register(struct class *); extern void class_unregister(struct class *); +extern int class_for_each_device(struct class *class, void *data, + int (*fn)(struct device *dev, void *data)); +extern struct device *class_find_device(struct class *class, void *data, + int (*match)(struct device *, void *)); +extern struct class_device *class_find_child(struct class *class, void *data, + int (*match)(struct class_device *, void *)); struct class_attribute { -- 1.5.3.8 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/