From 4644e5ab06dda96f7080569992202e1aec8d3b07 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Thu, 5 Feb 2015 21:38:58 +0100 Subject: [PATCH] xen: pcpu: Use static attribute groups for sysfs entry Instead of manual calls of device_create_file() and device_remove_file(), assign the static attribute groups to the device to register. The conditional build of sysfs is done in is_visible callback instead. Signed-off-by: Takashi Iwai Signed-off-by: David Vrabel --- drivers/xen/pcpu.c | 44 ++++++++++++++++++++++++++++---------------- 1 file changed, 28 insertions(+), 16 deletions(-) diff --git a/drivers/xen/pcpu.c b/drivers/xen/pcpu.c index 0aac403d53fd..49e88f2ce7a1 100644 --- a/drivers/xen/pcpu.c +++ b/drivers/xen/pcpu.c @@ -132,6 +132,33 @@ static ssize_t __ref store_online(struct device *dev, } static DEVICE_ATTR(online, S_IRUGO | S_IWUSR, show_online, store_online); +static struct attribute *pcpu_dev_attrs[] = { + &dev_attr_online.attr, + NULL +}; + +static umode_t pcpu_dev_is_visible(struct kobject *kobj, + struct attribute *attr, int idx) +{ + struct device *dev = kobj_to_dev(kobj); + /* + * Xen never offline cpu0 due to several restrictions + * and assumptions. This basically doesn't add a sys control + * to user, one cannot attempt to offline BSP. + */ + return dev->id ? attr->mode : 0; +} + +static const struct attribute_group pcpu_dev_group = { + .attrs = pcpu_dev_attrs, + .is_visible = pcpu_dev_is_visible, +}; + +static const struct attribute_group *pcpu_dev_groups[] = { + &pcpu_dev_group, + NULL +}; + static bool xen_pcpu_online(uint32_t flags) { return !!(flags & XEN_PCPU_FLAGS_ONLINE); @@ -181,9 +208,6 @@ static void unregister_and_remove_pcpu(struct pcpu *pcpu) return; dev = &pcpu->dev; - if (dev->id) - device_remove_file(dev, &dev_attr_online); - /* pcpu remove would be implicitly done */ device_unregister(dev); } @@ -200,6 +224,7 @@ static int register_pcpu(struct pcpu *pcpu) dev->bus = &xen_pcpu_subsys; dev->id = pcpu->cpu_id; dev->release = pcpu_release; + dev->groups = pcpu_dev_groups; err = device_register(dev); if (err) { @@ -207,19 +232,6 @@ static int register_pcpu(struct pcpu *pcpu) return err; } - /* - * Xen never offline cpu0 due to several restrictions - * and assumptions. This basically doesn't add a sys control - * to user, one cannot attempt to offline BSP. - */ - if (dev->id) { - err = device_create_file(dev, &dev_attr_online); - if (err) { - device_unregister(dev); - return err; - } - } - return 0; }