s390/cio: css attribute cleanup

Cleanup the code to handle the css device attribute. Move everything
to an attribute group to let the driver core handle attribute
creation and removal.

Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c
index 13fea905c61a9616989b9055bd34f19b1fe3afd7..59bd441b1cd3853ff3e5c71d78f60949914e7115 100644 (file)
--- a/drivers/s390/cio/css.c
+++ b/drivers/s390/cio/css.c
@@ -729,28 +729,24 @@ channel_subsystem_release(struct device *dev)
        kfree(css);
 }
 
-static ssize_t
-css_cm_enable_show(struct device *dev, struct device_attribute *attr,
-                  char *buf)
+static ssize_t cm_enable_show(struct device *dev, struct device_attribute *a,
+                             char *buf)
 {
        struct channel_subsystem *css = to_css(dev);
        int ret;
 
-       if (!css)
-               return 0;
        mutex_lock(&css->mutex);
        ret = sprintf(buf, "%x\n", css->cm_enabled);
        mutex_unlock(&css->mutex);
        return ret;
 }
 
-static ssize_t
-css_cm_enable_store(struct device *dev, struct device_attribute *attr,
-                   const char *buf, size_t count)
+static ssize_t cm_enable_store(struct device *dev, struct device_attribute *a,
+                              const char *buf, size_t count)
 {
        struct channel_subsystem *css = to_css(dev);
-       int ret;
        unsigned long val;
+       int ret;
 
        ret = kstrtoul(buf, 16, &val);
        if (ret)
@@ -769,8 +765,28 @@ css_cm_enable_store(struct device *dev, struct device_attribute *attr,
        mutex_unlock(&css->mutex);
        return ret < 0 ? ret : count;
 }
+static DEVICE_ATTR_RW(cm_enable);
+
+static umode_t cm_enable_mode(struct kobject *kobj, struct attribute *attr,
+                             int index)
+{
+       return css_chsc_characteristics.secm ? attr->mode : 0;
+}
+
+static struct attribute *cssdev_cm_attrs[] = {
+       &dev_attr_cm_enable.attr,
+       NULL,
+};
+
+static struct attribute_group cssdev_cm_attr_group = {
+       .attrs = cssdev_cm_attrs,
+       .is_visible = cm_enable_mode,
+};
 
-static DEVICE_ATTR(cm_enable, 0644, css_cm_enable_show, css_cm_enable_store);
+static const struct attribute_group *cssdev_attr_groups[] = {
+       &cssdev_cm_attr_group,
+       NULL,
+};
 
 static int __init setup_css(int nr)
 {
@@ -798,6 +814,7 @@ static int __init setup_css(int nr)
        css->cssid = chsc_get_cssid(nr);
 
        dev_set_name(&css->device, "css%x", nr);
+       css->device.groups = cssdev_attr_groups;
        css->device.release = channel_subsystem_release;
        tod_high = (u32) (get_tod_clock() >> 32);
        css_generate_pgid(css, tod_high);
@@ -931,16 +948,11 @@ static int __init css_bus_init(void)
                        put_device(&css->device);
                        goto out_unregister;
                }
-               if (css_chsc_characteristics.secm) {
-                       ret = device_create_file(&css->device,
-                                                &dev_attr_cm_enable);
-                       if (ret)
-                               goto out_device;
-               }
                ret = device_register(&css->pseudo_subchannel->dev);
                if (ret) {
                        put_device(&css->pseudo_subchannel->dev);
-                       goto out_file;
+                       device_unregister(&css->device);
+                       goto out_unregister;
                }
        }
        ret = register_reboot_notifier(&css_reboot_notifier);
@@ -957,12 +969,6 @@ static int __init css_bus_init(void)
        isc_register(IO_SCH_ISC);
 
        return 0;
-out_file:
-       if (css_chsc_characteristics.secm)
-               device_remove_file(&channel_subsystems[i]->device,
-                                  &dev_attr_cm_enable);
-out_device:
-       device_unregister(&channel_subsystems[i]->device);
 out_unregister:
        while (i > 0) {
                struct channel_subsystem *css;
@@ -971,9 +977,6 @@ out_unregister:
                css = channel_subsystems[i];
                device_unregister(&css->pseudo_subchannel->dev);
                css->pseudo_subchannel = NULL;
-               if (css_chsc_characteristics.secm)
-                       device_remove_file(&css->device,
-                                          &dev_attr_cm_enable);
                device_unregister(&css->device);
        }
        bus_unregister(&css_bus_type);
@@ -993,8 +996,6 @@ static void __init css_bus_cleanup(void)
        for_each_css(css) {
                device_unregister(&css->pseudo_subchannel->dev);
                css->pseudo_subchannel = NULL;
-               if (css_chsc_characteristics.secm)
-                       device_remove_file(&css->device, &dev_attr_cm_enable);
                device_unregister(&css->device);
        }
        bus_unregister(&css_bus_type);