From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756080AbaHVL33 (ORCPT ); Fri, 22 Aug 2014 07:29:29 -0400 Received: from fw-tnat.cambridge.arm.com ([217.140.96.21]:53090 "EHLO cam-smtp0.cambridge.arm.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753476AbaHVL31 (ORCPT ); Fri, 22 Aug 2014 07:29:27 -0400 From: Sudeep Holla To: LKML , Greg Kroah-Hartman Cc: Sudeep Holla , Heiko Carstens , Lorenzo Pieralisi , Stephen Boyd , David Herrmann , Kay Sievers Subject: [PATCH] drivers: base: add cpu_device_create to support per-cpu devices Date: Fri, 22 Aug 2014 12:29:23 +0100 Message-Id: <1408706963-23195-1-git-send-email-sudeep.holla@arm.com> X-Mailer: git-send-email 1.8.3.2 In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sudeep Holla This patch adds a new function to create per-cpu devices. This helps in: 1. reusing the device infrastructure to create any cpu related attributes and corresponding sysfs instead of creating and dealing with raw kobjects directly 2. retaining the legacy path(/sys/devices/system/cpu/..) to support existing sysfs ABI 3. avoiding to create links in the bus directory pointing to the device as there would be per-cpu instance of these devices with the same name since dev->bus is not populated to cpu_sysbus on purpose Signed-off-by: Sudeep Holla Cc: Greg Kroah-Hartman --- drivers/base/cpu.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/cpu.h | 4 ++++ 2 files changed, 58 insertions(+) Hi Greg, Here is the alternate solution I could come up with instead of creating cpu class. cpu_device_create is very similar to device_create_groups_vargs w/o class support, but I could not reuse anything else to avoid creating similar function. Let me know your thoughts/suggestions on this. Regards, Sudeep diff --git a/drivers/base/cpu.c b/drivers/base/cpu.c index 277a9cfa9040..53f0c4141d05 100644 --- a/drivers/base/cpu.c +++ b/drivers/base/cpu.c @@ -363,6 +363,60 @@ struct device *get_cpu_device(unsigned cpu) } EXPORT_SYMBOL_GPL(get_cpu_device); +static void device_create_release(struct device *dev) +{ + kfree(dev); +} + +static struct device * +__cpu_device_create(struct device *parent, void *drvdata, + const struct attribute_group **groups, + const char *fmt, va_list args) +{ + struct device *dev = NULL; + int retval = -ENODEV; + + dev = kzalloc(sizeof(*dev), GFP_KERNEL); + if (!dev) { + retval = -ENOMEM; + goto error; + } + + device_initialize(dev); + dev->parent = parent; + dev->groups = groups; + dev->release = device_create_release; + dev_set_drvdata(dev, drvdata); + + retval = kobject_set_name_vargs(&dev->kobj, fmt, args); + if (retval) + goto error; + + retval = device_add(dev); + if (retval) + goto error; + + return dev; + +error: + put_device(dev); + return ERR_PTR(retval); +} + +struct device *cpu_device_create(struct device *parent, void *drvdata, + const struct attribute_group **groups, + const char *fmt, ...) +{ + va_list vargs; + struct device *dev; + + va_start(vargs, fmt); + dev = __cpu_device_create(parent, drvdata, groups, fmt, vargs); + va_end(vargs); + return dev; +} +EXPORT_SYMBOL_GPL(cpu_device_create); + #ifdef CONFIG_GENERIC_CPU_AUTOPROBE static DEVICE_ATTR(modalias, 0444, print_cpu_modalias, NULL); #endif diff --git a/include/linux/cpu.h b/include/linux/cpu.h index 95978ad7fcdd..bb790a5621c0 100644 --- a/include/linux/cpu.h +++ b/include/linux/cpu.h @@ -19,6 +19,7 @@ struct device; struct device_node; +struct attribute_group; struct cpu { int node_id; /* The node which contains the CPU */ @@ -39,6 +40,9 @@ extern void cpu_remove_dev_attr(struct device_attribute *attr); extern int cpu_add_dev_attr_group(struct attribute_group *attrs); extern void cpu_remove_dev_attr_group(struct attribute_group *attrs); +extern struct device *cpu_device_create(struct device *parent, void *drvdata, + const struct attribute_group **groups, + const char *fmt, ...); #ifdef CONFIG_HOTPLUG_CPU extern void unregister_cpu(struct cpu *cpu); extern ssize_t arch_cpu_probe(const char *, size_t); -- 1.8.3.2